JP2012142318A - Manufacturing method of pattern substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for forming a conductive pattern which is excellent in insulation quality of a non pattern formation part and has a uniform and extremely small width or thickness.SOLUTION: A manufacturing process of a pattern substrate where a conductive pattern is formed on the substrate is composed of (1) a first print process in which a conductive paste (A) is printed on a pattern part corresponding to the position of the conductive pattern in a substrate surface, (2) a second print process in which a conductive paste (B), which forms a sintered body having lower adhesion to the substrate compared to the conductive paste (A), is printed between protruding parts of the formed conductive paste (A), (3) a sintered process in which the substrate that has been subjected to the second print process is sintered, (4) a planation process in which the conductive paste (A) and a surface of the sintered body of the conductive paste (B) are planarized, and (5) an etching process in which the sintered body of the conductive paste (B), formed on a non pattern part corresponding to a portion of the substrate surface which excludes the pattern part, is etched.

Description

  The present invention relates to a method of manufacturing a pattern substrate having a conductor pattern formed on the substrate, a pattern substrate obtained by this method, and an electronic circuit board or component including the pattern substrate.

  Known methods for forming a conductor pattern (conductive pattern) on a substrate include a screen printing method and an etching method.

  In the method using the screen printing method, the conductive paste is passed through a screen mesh having the same opening as the conductive pattern to be formed, and then printed, and then the conductive paste is baked to form the conductive pattern. Such a method using a screen printing method is a simple method and has an advantage that a conductor pattern can be formed at a low cost. However, since a paste material that is a viscous fluid is used, the paste tends to sag after printing, and adjacent patterns may come into contact with each other (short circuit). For this reason, it is difficult to meet the demand for forming a fine pattern because the interval between patterns must be widened.

  Also, in applications where another conductive member (such as a chip) is mounted on the surface of the conductive pattern, the inclination of the conductive member after mounting is suppressed, the bonding strength between the conductive member and the conductive pattern is increased, or the conductive member For the purpose of efficiently releasing heat generated from the conductor to the conductor side (board side), the contact area between the conductive member and the conductor pattern surface must be as large as possible, and therefore flatness of the conductor surface is required. There is. From this point of view, the screen printing method is not suitable for forming a conductor pattern. In other words, the pattern of the conductive paste formed by screen printing (unsintered pattern) has a swelled pattern shape due to the dripping of the paste after printing, and the surface of the conductor pattern is flat. There was a problem of not becoming.

  In order to prevent the dripping of the paste, such a problem can be somewhat improved if the viscosity of the paste is changed so that the dripping hardly occurs. However, since the fluidity of the paste is lowered, the leveling after printing is deteriorated, the screen mesh marks remain, the surface of the conductor pattern is remarkably roughened, and as a result, the smoothness of the conductor pattern is impaired. Such a decrease in the smoothness of the surface of the conductor pattern is a factor for reducing the contact area between the conductive pattern and the conductive member, as described above.

  On the other hand, in a method using an etching method, after a conductor film is formed on a substrate, portions other than those necessary as a pattern are removed by etching to form a pattern. For example, Japanese Patent Laid-Open No. 6-204645 (Patent Document 1) discloses a step of applying a conductor paste mainly composed of copper particles once or a plurality of times on a ceramic substrate, and a ceramic substrate coated with the copper conductor paste. Firing a copper conductor layer on the ceramic substrate, polishing the copper conductor layer, and forming a resist film having a predetermined pattern on the copper conductor layer subjected to the polishing treatment, A method of manufacturing a ceramic circuit board including a step of forming a circuit by performing an etching process is disclosed.

  If such a method using the etching method is used, a fine pattern can be formed and the surface becomes smooth, so there is no problem as in the case of screen printing the pattern. However, the electrical insulation of the portion removed by etching is lowered for the following reasons. That is, the conductive paste for forming the conductor film is usually made of glass powder or the like in order to give sufficient adhesion to an insulating substrate such as ceramics after the conductor paste is fired in addition to the conductive component. An adhesive component is blended, and such an adhesive component moves to the interface between the conductor film and the insulating substrate by melt flow during firing, and adheres or adheres to the fired conductive film and the insulating substrate. Functions as a layer (adhesion layer). In addition, the adhesive layer is composed of a mixture of an adhesive component and a conductive component, and as such an adhesive component, a component having excellent chemical resistance so that it can withstand chemical treatment such as etching and plating. Is used. Therefore, such an adhesive layer remains even after etching, and the insulating property of the etched portion is lowered.

  Further, when the conductor pattern surface is further plated after etching, the plating may be deposited on the remaining adhesive layer. Such deposition of the plating on the adhesive layer causes a further decrease in insulation, and in an extreme case, may cause a short circuit.

  In the etching method, the conductor film may be formed by plating (electrolytic or electroless plating) regardless of the application of the conductive paste. However, such a method using plating is expensive because it takes time to grow the plating, and the bonding reliability between the conductive film formed by plating and the substrate is not sufficient.

JP-A-6-204645 (Claims)

  An object of the present invention is to provide a method for efficiently producing a pattern substrate having a conductor pattern formed on the substrate, and a pattern substrate obtained by this method.

  Another object of the present invention is to provide a method for producing a pattern substrate having excellent insulation between conductor patterns even if the conductor pattern is fine, and a pattern substrate obtained by this method.

  Still another object of the present invention is to provide a method of manufacturing a pattern substrate on which a conductor pattern having a relatively uniform thickness or width is formed, and a pattern substrate obtained by this method.

  As a result of intensive studies to achieve the above-mentioned problems, the present inventors have, in addition to the part forming the pattern (pattern forming part), in addition to the part not forming the pattern (non-forming part) in the substrate surface, By printing (coating) a specific conductive paste that can form a sintered body with lower adhesion to the substrate than the conductive paste of the pattern formation part, and sintering it, the pattern non-formation part can be easily etched, Even if the conductor pattern (interval between conductor patterns) is miniaturized, a pattern substrate with excellent insulation between the conductor patterns can be obtained, and the pattern can be formed by printing a conductive paste on the non-patterned part. Even if the conductive paste printed on the part forms a bulging (cross-sectionally shaped) convex pattern by dripping, such a gap (or gap) between the convex patterns is formed. That can be filled with a conductive paste, as a result found that it is possible to relatively uniform thickness the thickness of the conductive pattern after etching the central portion of the pattern up to the end, and completed the present invention.

That is, the method of the present invention is a method of manufacturing a patterned substrate having a conductor pattern formed on a substrate,
A first printing step of printing (pattern printing) the conductive paste (A) on a predetermined portion (a predetermined pattern portion, a pattern portion corresponding to the position of the conductor pattern) of the substrate surface;
Sintered body having lower adhesion to the substrate than the conductive paste (A) between the convex portions of the formed conductive paste (A) (or between unsintered patterns composed of the conductive paste (A)) A second printing step of printing or coating (coating) the conductive paste (B) capable of forming
A sintering step of sintering the substrate that has undergone the second printing step;
Etching process for etching the sintered body of the conductive paste (B) formed on the non-pattern part except the pattern part (specifically, the non-pattern part corresponding to the part excluding the pattern part) on the substrate surface Including.

  The conductive paste (A) and the conductive paste (B) may contain a conductive metal as a conductive agent. In addition, the conductive paste (A) may usually contain glass, and the conductive paste (A) is made more conductive than the weight ratio of the glass to the conductive metal constituting the conductive paste (B). You may enlarge the weight ratio of the glass with respect to a property metal. Specifically, the proportion of glass in the conductive paste (A) is A parts by weight with respect to 100 parts by weight of the conductive metal constituting the conductive paste (A), and the glass in the conductive paste (B). When the ratio of B is B parts by weight with respect to 100 parts by weight of the conductive metal constituting the conductive paste (B), the AB value is 0.5 parts by weight or more (for example, 1 part by weight or more). May be. The proportion of glass in the conductive paste (A) is, for example, 1.5 parts by weight or more (for example, 1.8 parts by weight) with respect to 100 parts by weight of the conductive metal constituting the conductive paste (A). The ratio of glass in the conductive paste (B) is, for example, 3 parts by weight or less (for example, 2 parts) with respect to 100 parts by weight of the conductive metal constituting the conductive paste (B). .5 parts by weight or less).

  In the second printing step, the conductive paste (B) may be printed in a form in which the gaps between the convex portions of the conductive paste (A) are filled. In the second printing step, the conductive paste (B) may be printed so as to cover the convex portions of the conductive paste (A) (the convex portions are embedded). Furthermore, in the second printing step, the conductive paste (B) may be printed a plurality of times.

  In the method, a pre-sintering step of sintering the conductive paste (A) may be further included between the first printing step and the second printing step.

  Moreover, in the said method, between the 2nd printing process and a sintering process, it is a preliminary | backup which grind | polishes (or planarizes or smoothes) the surface of an electrically conductive paste (A) and an electrically conductive paste (B) further. A polishing step (planarization step) may be included.

  Furthermore, in the said method, between the sintering process and an etching process, the grinding | polishing process (flat surface) which grind | polishes (planarization or smoothing) the sintered compact surface of an electrically conductive paste (A) and an electrically conductive paste (B). Conversion step or smoothing step).

  In the above method, the surface roughness Ra of the surface of the sintered body may be set to 0.3 μm or less by the polishing step.

The present invention also includes a patterned substrate obtained by the above method. In such a pattern substrate, of the widths of the conductor pattern, the difference between the width of the portion in contact with the substrate and the width of the surface portion may be, for example, 10 μm or less, and the interval between the conductor patterns is 70 μm or less. For example, the resistance value of the non-pattern forming portion may be 1 × 10 ¹⁰ Ω or more. In the pattern substrate, the conductor pattern may be further plated.

  The present invention also includes an electronic circuit board or component provided with the pattern board.

  In the method of the present invention, a patterned substrate having a conductor pattern formed on the substrate can be efficiently produced. In particular, since the second conductive paste having poor adhesion to the substrate is printed on the portion where the conductor pattern is not formed, the portion where the conductor pattern is not easily formed can be etched, and even if the conductor pattern is fine, A pattern substrate excellent in insulation between conductor patterns can be manufactured. Further, in the method of the present invention, the gap between the conductor patterns can be filled with the sintered body of the second conductive paste, so that the thickness is uneven as seen in screen printing (cross-section kamaboko). A conductive pattern having a relatively uniform thickness can be formed not from the pattern but from the center to the end of one pattern.

<First printing process>
In the first printing step, a conductive paste (A) may be formed on a predetermined pattern portion (that is, a pattern portion corresponding to the position of the conductor pattern, a predetermined portion, or a pattern forming portion) on the substrate surface. ) Is printed (pattern printing).

[substrate]
The substrate (insulating substrate or insulating substrate) is not particularly limited as long as it is a substrate that can withstand the sintering treatment (firing temperature), and can be selected according to the application. Examples of such a substrate include a ceramic substrate, a glass ceramic substrate, a silicone wafer substrate, and an enamel substrate. In particular, ceramic substrates such as an alumina substrate and an aluminum nitride substrate are excellent in heat resistant temperature, mechanical strength, and chemical resistance, and can be suitably used in the present invention.

  The substrate may be a sintered substrate that has been sintered in advance, or may be a green sheet substrate. When such a green sheet-like substrate is used as a raw material substrate, a sintered substrate (simultaneously sintered substrate) is obtained together with the sintering treatment of the conductive paste (A) (and the conductive paste (B)). be able to. Since the green sheet is soft and inferior in supportability, it is preferable to sinter the substrate at an appropriate stage before the planarization step described later.

  In addition, the surface of the substrate may be subjected to oxidation treatment [surface oxidation treatment, for example, high-temperature oxidation treatment, discharge treatment (corona discharge treatment, glow discharge, etc.), acid treatment (chromic acid treatment, etc.), ultraviolet irradiation treatment, as necessary. Surface treatment such as glazing treatment, surface unevenness treatment (solvent treatment, sandblast treatment, etc.) may be performed.

  What is necessary is just to select the thickness of a board | substrate suitably according to a use, for example, 0.05-10 mm, Preferably it is 0.1-5 mm, More preferably, it may be about 0.2-3 mm.

[Conductive paste (A)]
The conductive paste (A) is not particularly limited as long as it is a paste containing at least a conductive agent, but usually it is often a paste containing at least a conductive metal as a conductive agent.

(Conductive metal)
The conductive metal can be appropriately selected depending on the application. For example, transition metal (for example, periodic table group 5A metal such as niobium; periodic table group 6A metal such as molybdenum and tungsten; periodic table 7A such as manganese; Group metal: Periodic table Group 8 metals such as iron, nickel, cobalt, ruthenium, rhodium, palladium, rhenium, iridium, platinum; Periodic table Group 1B metals such as copper, silver, gold, etc.), Periodic table Group 2B In addition to simple metals such as metals (for example, zinc) and Group 3B metals (for example, aluminum) of the periodic table, alloys of these metals, compounds of these metals (metal sulfides, metal carbides, metal nitrides, Metal borides and the like).

  The conductive metal may usually be a single metal or a metal alloy. Representative conductive metals include, for example, nickel, copper, silver, and aluminum from the viewpoint of having good electrical characteristics. Among these, copper is preferable from the viewpoint that a film that is inexpensive, has high conductivity, and can be easily stretched by polishing can be obtained.

  The conductive metals may be used alone or in combination of two or more.

  The form (or shape) of the conductive agent (conductive metal) is not particularly limited, but a particulate conductive agent (such as conductive metal particles) may be suitably used. The average particle diameter of the particulate conductive agent may be, for example, about 0.01 to 50 μm, preferably about 0.05 to 20 μm, and more preferably about 0.1 to 10 μm.

(Glass)
Moreover, the conductive paste (A) may usually contain glass. Since glass can be softened during the sintering process to form a strong adhesive layer between the substrate and the sintered metal pattern, it is preferable in that it provides excellent adhesion to the substrate.

The glass is not particularly limited as long as adhesion to the substrate can be imparted. For example, soda lime glass, glass containing boron (B ₂ O ₃ ) (for example, borosilicate glass, zinc borosilicate glass, lead borosilicate glass, borosilicate) Barium acid glass, strontium borosilicate glass, potassium borosilicate glass, aluminoborosilicate glass, bismuth borosilicate glass, etc.), lead glass, aluminosilicate glass, phosphate glass, quartz glass and the like. Glasses may be used alone or in combination of two or more.

As the glass, it is preferable to use a glass excellent in resistance to chemicals such as a chemical etching solution, acid and alkali. Typical glass includes, for example, glass containing boron (B ₂ O ₃ ) (for example, borosilicate glass, zinc borosilicate glass, lead borosilicate glass) from the viewpoint of chemical resistance (alkali resistance, acid resistance) and the like. , Barium borosilicate glass, strontium borosilicate glass, potassium borosilicate glass, alumino borosilicate glass, etc.).

A glass containing boron (borosilicate glass) is a glass containing at least boron (B ₂ O ₃ ) and silicon (SiO ₂ ), and in addition to these, a metal oxide [eg, alkali metal oxide (eg, Li ₂ O, Na ₂ O, K ₂ O, etc.), alkaline earth metals (eg, MgO, CaO, SrO, BaO, etc.), transition metal oxides (eg, MnO ₂ , ZnO), periodic table group 13 metal oxidation Product (for example, Al ₂ O ₃ ), periodic table group 14 metal oxide (for example, PbO, Pb ₂ O ₅ ), periodic table group 15 metal oxide (for example, Sb ₂ O ₃ , Bi ₂ O ₃ ) Etc.] may be included.

In the glass containing boron, the proportion of boron may be, for example, about 5 to 50% by weight, preferably 7 to 40% by weight, and more preferably about 10 to 30% by weight in terms of B ₂ O ₃ . In the glass containing boron, the ratio of silicon may be, for example, 10 to 80% by weight, preferably 20 to 70% by weight, and more preferably about 30 to 65% by weight in terms of SiO ₂ . In the glass containing boron, the proportion of zinc is, for example, 0 to 75% by weight (for example, 0 to 70% by weight), preferably 0 to 50% by weight, and more preferably 0 to 30% by weight in terms of ZnO. It may be a degree. In addition, in the borosilicate glass (zinc borosilicate glass) containing zinc, the ratio of zinc is 5-75 weight% (for example, 7-60 weight%) in conversion of ZnO, Preferably it is 10-50 weight% ( For example, it may be about 12 to 40% by weight), more preferably about 15 to 30% by weight.

  In addition, although the shape (or form) of glass is not specifically limited, Usually, a particle form (frit shape) may be sufficient. In the particulate glass (glass particles, glass frit), the average particle diameter may be, for example, about 0.1 to 50 μm, preferably about 0.5 to 20 μm, and more preferably about 1 to 10 μm.

(Binder resin)
The conductive paste (A) may contain a binder resin in order to improve the applicability (printability) of the paste and to maintain a predetermined film shape (pattern shape) on the substrate surface. It does not specifically limit as binder resin, For example, a thermoplastic resin may be sufficient. Typical binder resins include, for example, styrene resins [for example, copolymers of styrene and (meth) acrylic monomers such as polystyrene and styrene-methyl methacrylate copolymer, styrene-acrylonitrile copolymers. Etc.], (meth) acrylic resin {for example, poly (meth) acrylic acid ester (for example, polymethyl methacrylate, polybutyl (meth) acrylate, polyisobutyl methacrylate, etc.), methyl methacrylate- (meth) acrylic acid copolymer , (Meth) acrylic monomers such as methyl methacrylate-acrylic acid ester copolymer, poly (meth) acrylamide [for example, (meth) acrylic acid; (meth) acrylic acid alkyl (for example, (meth) acrylic acid Methyl, ethyl (meth) acrylate, (meth) acrylate Le, (meth) such as isobutyl acrylate (meth) acrylic acid _{C 1-20} alkyl, preferably (meth) acrylic acid _{C 1-10} alkyl) (meth) acrylic acid esters and the like; (meth) acrylamide, etc.] Homopolymer or copolymer; heat or photocurable acrylic resin, etc.}, olefin resin (for example, ethylene-vinyl acetate copolymer, ethylene-vinyl alcohol copolymer, ethylene- (meth) acrylic acid ester copolymer) ), Vinyl ester resins (eg, polyvinyl acetate, polyvinyl alcohol, etc.), halogen-containing resins (polyvinyl chloride, vinyl chloride-vinyl acetate copolymers, etc.), polyester resins (polyethylene terephthalate, polybutylene terephthalate, Aromatic polyester trees such as polybutylene naphthalate Fats; aliphatic polyester resins, etc.), polyurethane resins, polyamide resins, polyimide resins, polysaccharides or derivatives thereof [for example, cellulose derivatives (for example, cellulose acetate, cellulose acetate propionate, cellulose acetate butyrate, etc. Cellulose esters; cellulose ethers such as methylcellulose, ethylcellulose, sodium carboxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, hydroxypropylmethylcellulose; nitrocellulose, starch, guar gum, gum arabic, sodium alginate, etc.], rubber or elastomer (for example Acrylic rubber, butadiene rubber, styrene-butadiene rubber, etc.).

  Binder resins may be used alone or in combination of two or more.

(solvent)
The conductive paste (A) usually contains a solvent. As the solvent, a solvent that can be selected according to the type of the binder resin, etc., can give an appropriate viscosity to the conductive paste, and can be easily removed (volatilized) by a drying treatment or the like can be suitably used.

Typical solvents include, for example, alcohols {eg, saturated or unsaturated fatty alcohols (eg, heptanol, octanol, decanol, lauryl alcohol, tetradecyl alcohol, cetyl alcohol, octadecyl alcohol, hexadecenol, oleyl alcohol). C _6-30 aliphatic alcohols, preferably saturated or unsaturated C _8-24 aliphatic alcohols), alicyclic alcohols [eg, cycloalkanols such as cyclohexanol; terpene alcohols such as terpineol and dihydroterpineol ( For example, monoterpene alcohol etc.), araliphatic alcohols (eg benzyl alcohol, phenethyl alcohol etc.), phenols [eg cresol (metacresol etc.) Etc.], polyhydric alcohols (ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, glycols such as (poly) C _2-4 alkylene glycols such as triethylene glycol; multi having 3 or more hydroxyl groups such as glycerin Etc.}, glycol ethers (eg, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, triethylene glycol monobutyl ether, propylene glycol) Monomethyl ether, dipropylene glycol monomethyl ether, triplicate (Poly) alkylene glycol monoalkyl ethers such as pyrene glycol butyl ether; (poly) alkylene glycol monoaryl ethers such as 2-phenoxyethanol), glycol ether esters (eg, ethylene glycol monoethyl ether acetate, ethylene glycol monomethyl ether acetate, (Poly) alkylene glycol monoalkyl ether acetates such as diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate), hydrocarbons [eg aliphatic hydrocarbons (eg tetradecane, octadecane, heptamethylnonane) , Saturated or unsaturated aliphatic such as tetramethylpentadecane Hydrocarbons), aromatic hydrocarbons (eg, toluene, xylene (paraxylene, etc.), etc.), ketones (eg, chain ketones, such as acetone and diacetone alcohol; cyclic ketones, such as isophorone), ethers (For example, cyclic ethers such as tetrahydrofuran and dioxane), esters [for example, lactic acid esters (for example, ethyl lactate), fatty acid esters such as acetic acid esters (for example, benzyl acetate, isoborneol acetate); benzoic acid esters (benzoic acid) Aromatic carboxylic acid esters such as methyl and ethyl benzoate], nitrogen-containing solvents [eg, amides (eg, formamides such as dimethylformamide), imidazoles (eg, dimethylimidazole, etc.), dimethylimidazolidinone, etc. ] Etc. are mentioned.

  The solvents may be used alone or in combination of two or more.

  In addition to the above components, the conductive paste (A) may contain various additives (for example, a surfactant or a dispersant, a dispersion stabilizer, a thickener or a viscosity modifier, an antifoaming agent). And other components may be included. These additives can be used alone or in combination of two or more.

(Ratio of each component)
In the conductive paste (A), the proportion of the conductive agent is, for example, 50% by weight or more (for example, 55 to 98% by weight), preferably 60, although it depends on the type of conductive agent and the desired degree of conductivity. It may be 70% by weight or more (eg, 75-90% by weight), more preferably 70% by weight or more (eg, 75-90% by weight).

  In the conductive paste (A) containing glass, the proportion of glass is 0.5 parts by weight or more (for example, 0.7 to 50 parts by weight with respect to 100 parts by weight of the conductive agent (particularly conductive metal)). ), For example, 1 part by weight or more (for example, 1.2 to 40 parts by weight), preferably 1.5 parts by weight or more (for example, 1.6 to 30 parts by weight), more preferably 1. It may be 8 parts by weight or more (for example, 1.9 to 20 parts by weight), usually 1.5 to 18 parts by weight (for example, 1.8 to 15 parts by weight), or 2 parts or more [for example, 2. 1 part by weight or more (for example, 2.2 to 30 parts by weight), preferably 2.5 to 20 parts by weight, and more preferably 3 to 18 parts by weight.

  In addition, in the electrically conductive paste (A) containing glass, the ratio of glass is 0.3 weight% or more (for example, 0.5-30 weight%), for example, Preferably it is 0.7 weight% or more (for example, 0 0.8 to 20% by weight), more preferably about 1% by weight or more (for example, 1.2 to 15% by weight), and usually 1 to 15% by weight (for example, 1.5 to 12% by weight). It may be a degree.

  When the conductive paste (A) containing glass at such a ratio is used, excellent adhesion to the substrate can be efficiently realized without impairing conductivity.

  Moreover, in the conductive paste (A) containing the binder resin, the ratio of the binder resin is, for example, 1 to 50 parts by weight (for example, 1.5 to 40 parts by weight), preferably 100 parts by weight of the conductive agent. It may be about 2 to 30 parts by weight, more preferably about 3 to 20 parts by weight.

  In the conductive paste (A), the ratio of the solid content (for example, the total amount of the conductive agent, glass, and binder resin) is, for example, 60% by weight or more (for example, 65 to 99.5% by weight), preferably 70. It may be not less than wt% (for example, 75 to 99 wt%), more preferably not less than 80 wt% (for example, 85 to 98 wt%), particularly about 90 to 97 wt%.

  The viscosity of the conductive paste (A) can be selected according to the application and the coating method to be applied, but is usually 0.5 Pa · s or more (for example, 1 to 400 Pa · s), preferably 3 Pa · s at 25 ° C. s or more (for example, 5 to 300 Pa · s), more preferably about 10 to 250 Pa · s (for example, 20 to 200 Pa · s), and usually about 1 to 300 Pa · s.

[Printing method]
The conductive paste (A) is printed (coated or transferred) on the pattern forming portion of the substrate surface. The printing method is not particularly limited as long as the conductive paste (A) can be printed on the substrate with a desired shape pattern. For example, the screen printing method, the intaglio printing method, the letterpress printing method, the ink jet printing method, and the offset printing. A known printing method such as a printing method, a flexographic printing method, or a gravure printing method can be used.

  Among these, screen printing is preferable because it is inexpensive and can easily handle the formation of a thick film. In typical screen printing, a conductive paste is coated on a screen mask to a predetermined thickness (for example, thinly) using a scraper, and then the conductive paste is passed through the screen mesh opening using a squeegee, whereby a substrate is obtained. The pattern is printed on. The scraper and squeegee are not particularly limited, and a general scraper made of metal or a squeegee made of rubber such as urethane or silicone can be used. As the screen mask, a mask obtained by forming a negative pattern on a commonly used screen mesh with a photosensitive agent, or a metal mask provided with an opening so that the pattern portion can be pasted with a metal material such as stainless steel can be used. Mask specifications such as the fineness of the mesh, the photosensitive agent, and the thickness of the metal may be appropriately selected according to the required pattern size. Printing conditions such as squeegee speed, clearance, and squeegee pressure can be freely selected as appropriate and are not limited. Since the conductive paste (A) is in a paste form, the width of the opening of the screen mesh may be made smaller than the width of the desired pattern.

  The width (maximum width) of the conductive paste (A) [or the convex portion (convex portion pattern) or unfired pattern of the conductive paste (A)] formed on the substrate by printing is, for example, 1 to 300 μm, preferably May be about 3 to 250 μm, more preferably about 5 to 200 μm (for example, 10 to 180 μm), particularly about 20 to 150 μm (for example, 30 to 120 μm).

  Moreover, the distance (or insulating width) between the convex parts (between adjacent convex parts) of the conductive paste (A) formed on the substrate by printing is, for example, 5 to 150 μm, preferably 10 to 120 μm, and more preferably. May be about 15 to 100 μm (for example, 20 to 90 μm), particularly about 25 to 80 μm (for example, 30 to 70 μm). In this invention, even if it is such a fine pattern, the insulation which was excellent in the non-pattern formation part can be provided.

  In addition, although the shape of the convex part of the electrically conductive paste (A) formed on a board | substrate is based also on the degree of the viscosity of a paste, it is a bulging shape (cross-sectionally kamaboko shape) normally.

  The conductive paste (A) may be printed on one side or both sides of the substrate. When printing on both sides, both sides may be subjected to a later-described step, or only one side may be subjected to a later-described step. In the case of printing on both sides, when high-precision electrode formation is required only on one side, the manufacturing cost can be suppressed by subjecting only one side to the steps described later.

  In addition, you may perform a drying process to the board | substrate after printing the electrically conductive paste (A) prior to the below-mentioned pre-sintering process and 2nd printing process as needed.

<Pre-sintering process>
After the first printing step, the substrate on which the pattern of the conductive paste (A) is printed may be directly used for the second printing step, and if necessary, sintered before the second printing step. You may process (or baking processing). By subjecting the conductive paste (A) to a sintering treatment before the second printing step, the adhesion to the substrate may be further improved, or delamination may be efficiently prevented. In the preliminary sintering step, the sintering (firing) conditions are the same as those described later.

<Second printing process>
In the second printing step, the conductive paste (B) is printed between the convex portions of the conductive paste (A) formed by printing (or between the convex portions or gaps).

[Conductive paste (B)]
The conductive paste (B) only needs to be able to form a sintered body (sintered product or sintered film) having lower adhesion to the substrate than the conductive paste (A). That is, it is only necessary that the etching removability of the sintered body of the conductive paste (B) (for example, ease of removal by the etching solution) can be made relatively higher than that of the sintered body of the conductive paste (A).

  As a method for making such etching removability relatively high, for example, (1) a method of making the proportion of glass in the conductive paste (B) relatively small compared to the conductive paste (A), ( 2) As the glass in the conductive paste (B), there may be mentioned a method of using a glass having better etching removability than the glass of the conductive paste (A).

  In particular, the conductive paste (B) (sintered body) preferably has sufficient conductivity to form a part of the conductor pattern, as will be described later. Therefore, the former method (1) can be suitably used in that adhesion to the substrate can be lowered while maintaining sufficient conductivity. In such a method, since the proportion of the conductive agent in the conductive paste (B) can be relatively increased by reducing the glass content, it is rather more conductive than the conductive paste (A). A sintered body can also be formed. Hereinafter, the method (1) will be described in detail.

  The conductive paste (B) may be smaller than the conductive paste (A) in the glass content. For example, the weight of the glass with respect to the conductive agent (particularly conductive metal) constituting the conductive paste (A) rather than the weight ratio of the glass with respect to the conductive agent (particularly conductive metal) constituting the conductive paste (B). The proportion may be increased. Specifically, the proportion of glass in the conductive paste (A) is set to A parts by weight with respect to 100 parts by weight of the conductive agent (particularly conductive metal) constituting the conductive paste (A). When the proportion of glass in (B) is B parts by weight with respect to 100 parts by weight of the conductive agent (particularly conductive metal) constituting the conductive paste (B), the value of AB is, for example, 0.3 parts by weight or more (for example, 0.4 to 40 parts by weight), preferably 0.5 parts by weight or more (for example, 0.7 to 30 parts by weight), more preferably 1 part by weight or more (for example, 1.. 2 to 20 parts by weight), particularly 1.5 parts by weight or more (for example, 1.7 to 18 parts by weight).

  In addition, the conductive paste (B) does not need to contain glass (or substantially contain), and if the adhesiveness to the substrate can be relatively lowered than the conductive paste (A), It may contain glass. The conductive paste (B) preferably does not contain glass from the viewpoint of adhesion to the substrate and conductivity, but a load acts on the conductor pattern in the planarization step described later, and in some cases the glass is made conductive. In some cases, it may be better to make the paste (B) adhere to the substrate weakly. For example, when the interval between pattern forming parts is large, the area ratio of the non-pattern part that does not adhere to the substrate increases, and it may not withstand the stress of planarization and may peel off. In a case where there is a possibility of reaching not only the part but also the pattern forming part, such a problem can be efficiently prevented by adding a small amount of glass and weakly adhering to the substrate.

  From such a viewpoint, the proportion of glass in the conductive paste (B) is 10 parts by weight or less (for example, with respect to 100 parts by weight of the conductive agent (particularly conductive metal) constituting the conductive paste (B)). 0-7 parts by weight), for example, 5 parts by weight or less (eg, 0-4 parts by weight), preferably 3 parts by weight or less (eg, 0-2.7 parts by weight), more preferably It may be 2.5 parts by weight or less (for example, 0 to 2.2 parts by weight), particularly 2 parts by weight or less (for example, 0 to 1.5 parts by weight).

  When the conductive paste (B) contains glass, the proportion of glass in the conductive paste (B) is 100 parts by weight of the conductive agent (particularly conductive metal) constituting the conductive paste (B). For example, 0.1 parts by weight or more (for example, 0.2 to 5 parts by weight), preferably 0.3 parts by weight or more (for example, 0.4 to 4 parts by weight), more preferably 0.5 parts by weight. It may be about (for example, 0.7 to 3 parts by weight), particularly about 1 part by weight or more (for example, 1.2 to 2.5 parts by weight).

  In addition, examples of the glass contained in the conductive paste (B) include the same glass as described above.

  The conductive paste (B) may usually contain the same components as the conductive paste (A) except for glass. That is, the conductive paste (B) is a paste containing at least a conductive agent (such as the conductive agent illustrated above), and may include a binder resin (such as the binder resin illustrated above) as another component.

  The proportion of each component in these conductive pastes (B) can also be selected from the same range as that of the conductive paste (A) except for glass, but in the conductive paste (B), the conductive paste (A) In many cases, the glass content is relatively small.

  Therefore, the conductive paste (B) has a relatively larger content of the conductive agent than the conductive paste (A), that is, the weight of the conductive agent (particularly, conductive metal) contained in the conductive paste (A). In many cases, the weight ratio of the conductive agent (particularly, conductive metal) contained in the conductive paste (B) is larger than the ratio. Specifically, when the ratio of the conductive agent in the conductive paste (A) is A wt% and the ratio of the conductive agent in the conductive paste (B) is B wt%, the value of AB is For example, 0.3% by weight or more (for example, 0.5 to 30% by weight), preferably 0.7% by weight or more (for example, 0.8 to 20% by weight), more preferably 1% by weight or more (for example, 1.2 to 15 wt%), particularly 1.5 wt% or more (e.g. 1.7 to 12 wt%), usually 1 to 10 wt% (e.g. 1.5 to 9 wt%, It may be 1.7 to 8% by weight, more preferably 2 to 7% by weight.

  Moreover, the ratio and viscosity of the solid content in the conductive paste (B) can be selected from the same range as described above.

[Printing method]
In the second printing step, the conductive paste (A) (or the sintered body or the sintered pattern of the conductive paste (A) when conducting a pre-sintering process, the same applies) between the convex portions (or conductive) The conductive paste (B) is printed (coated) between the patterns of the conductive paste (A). In other words, the second printing step is a step of filling the conductive paste (B) in the gap between the convex pattern (or the unfired pattern or the sintered pattern thereof) formed of the conductive paste (A). I can say that.

  The printing method is not particularly limited, and the same method as described above can be used. The printing conditions are not particularly limited as described above.

  The conductive paste (B) only needs to be able to fill at least the gaps or regions (parts) between the convex portions, and only on the non-pattern portion (non-pattern formation portion) that does not form a conductor pattern on the substrate surface. It may be formed (printed), but in particular, the conductive paste (B) is printed in a form that fills the gaps between the convex portions (bulged convex portions or bulged unfired patterns) of the conductive paste (A). May be.

  That is, as described above, the shape of the convex portion (convex portion pattern) of the conductive paste (A) is usually a bulging shape (cross-section kamaboko) in which the thickness of both sides of the pattern is reduced due to the dripping of the paste. In many cases. Therefore, when the conductive paste (B) is printed in a form filling the convex portions, a part of the conductive paste (B) comes into contact (adherence) with the conductive paste (A) (or a sintered body thereof). The pattern is made uniform, and a conductor pattern having a uniform thickness or width is easily obtained by etching.

  In addition, the conductive paste (B) may be printed only between the convex portions of the conductive paste (A), or the convex portions of the conductive paste (A) are embedded (or the convex portions are covered). As well) may be printed. Specifically, the conductive paste (B) may be printed with a negative pattern opposite to the pattern (positive pattern) of the conductive paste (A) formed in the first printing step. The conductive paste (B) may be printed with a solid pattern on the entire surface so as to cover the pattern A). If the convex part of the conductive paste (A) is covered with the conductive paste (B), the conductor pattern can be easily thickened, and the polishing margin in the flattening step described later can be easily secured.

  The conductive paste (B) may be printed (overprinted) a plurality of times (for example, 2 to 10 times, preferably 2 to 5 times). The effect similar to the case where a convex part is coat | covered is acquired by overprinting.

  In addition, you may perform a drying process to the board | substrate after printing an electrically conductive paste (B) prior to the below-mentioned planarization process and sintering process as needed.

<Preliminary polishing process>
After the second printing step, the substrate on which the conductive paste (A) and the conductive paste (B) are printed may be directly subjected to the sintering step, and if necessary, prior to the second sintering step. A pre-polishing step (homogenization step or flattening step) for flattening (or polishing) the surfaces of the conductive paste (A) (or a sintered body thereof) and the conductive paste (B). You may go out. Since the film formed by the paste is unsintered, it is easy to flatten or polish, and can be easily flattened, and is combined with a polishing process (planarization process) for polishing the substrate surface after sintering, which will be described later. It is easy to polish the conductor pattern efficiently.

  In the planarization step, a method described later can be appropriately used as a polishing method.

<Sintering process>
In the sintering process (firing process), the substrate that has undergone the second printing process (and the flattening process) is subjected to a sintering process (or a firing process). For the firing step, for example, a conventional furnace such as a tunnel furnace or a batch furnace can be used.

  The firing temperature (sintering temperature) can be selected according to the type of glass (softening or melting temperature of the glass, etc.) and the type of conductive agent (melting point of the conductive agent, etc.), and is usually higher than the softening temperature of the glass. Any temperature lower than the melting point of the agent may be used. The specific firing temperature is, for example, 400 ° C. or higher (eg, 500 to 1600 ° C.), preferably 600 ° C. or higher (eg, 650 to 1300 ° C.), more preferably 700 ° C. or higher (eg, 800 to 1200 ° C.). In particular, it may be about 800 to 1100 ° C. (for example, 850 to 1000 ° C.). The holding time (calcination time) at the firing temperature may be, for example, about 5 minutes to 5 hours, preferably about 10 minutes to 3 hours, and more preferably about 20 minutes to 1 hour.

  The baking treatment may be performed in an oxidizing atmosphere, and in order to prevent oxidation [for example, oxidation of conductive metal (such as nickel)] depending on the application, non-oxidizing or inert atmosphere [for example, nitrogen, rare It may be performed under an inert gas such as a gas (helium, neon, argon, etc.).

  Through such a sintering treatment, a sintered body (sintered film) of the conductive paste (A) and the conductive paste (B) is formed on the substrate (or the substrate surface).

<Polishing process>
After the sintering process, the substrate on which the conductive paste (A) and the sintered body of the conductive paste (B) are formed may be directly subjected to the etching process, but prior to the etching process, the conductive paste (A And a polishing step of planarizing or smoothing the surface of the sintered body of the conductive paste (B) by polishing.

  The planarization (or homogenization) method is not particularly limited. For example, grinding, buffing, lapping (for example, polishing between parallel pads using diamond slurry), chemical polishing (for example, acid or Conventional polishing methods such as chemical mechanical polishing and the like can be used. The polishing methods may be used alone or in combination of two or more.

  In the buff polishing, for example, polishing is performed using a baffle in which abrasive grains such as silicone carbide are kneaded into a nonwoven fabric. As described above, polishing can also be performed in the flattening step, but if the surface is soft and the surface is soft to follow the unevenness when using buffol, it is difficult to flatten. It is also possible to use a spiral cutter in which a cube-shaped resin block kneaded with abrasive grains is arranged in a spiral shape and an elastic rubber layer is provided on the inside thereof. These polishing methods may be used singly or in combination, and after selecting the abrasive grain size, for example, rough polishing with large abrasive grains for flattening to eliminate unevenness due to printing, a desired surface roughness is obtained. Therefore, it is efficient when combined so as to perform final polishing with fine abrasive grains.

  Through such a polishing process, the surface of the sintered body (conductor pattern) is planarized. The surface roughness Ra of the surface of the sintered body after the polishing step can be selected from a range of 0.8 μm or less (for example, 0 or a detection limit to 0.7 μm), for example, 0.6 μm or less (for example, 0 to 0.00). 5 μm), preferably about 0.3 μm or less (for example, 0.01 to 0.28 μm), or 0.2 μm or less [for example, 0 to 0.15 μm, preferably 0.1 μm or less (for example, 0 .02 to 0.08 μm)].

  The thickness of the sintered body is, for example, about 1 to 150 μm (for example, 2 to 120 μm), preferably 3 to 100 μm (for example, 5 to 70 μm), and particularly about 7 to 50 μm (for example, 10 to 30 μm). Also good.

<Etching process>
In the etching process, the substrate surface was formed on a non-pattern part (non-pattern formation part) corresponding to a part other than the pattern formation part, that is, a part excluding the pattern part (position where the conductor pattern is not formed). The sintered body or the sintered film (that is, the sintered body of the conductive paste (B)) is etched.

  As an etching method, a conventional method can be used. Typically, the non-pattern forming portion exposed by the etching resist (etching resist film) is etched. The etching resist is not particularly limited, and is a film (for example, a film formed of an ultraviolet curable resin), a liquid resist (for example, an ultraviolet curable development type liquid resist, or a thermosetting (drying) printing type. A general resist such as a liquid resist can be used.

  In addition, since the ultraviolet curable resist can form a resist pattern having a high resolution and a good shape through a photolithography process such as exposure and development, the shape of the conductive pattern after etching that is finally obtained is excellent. Accuracy is easy to obtain. On the other hand, the printing resist method in which a resist pattern is formed on a conductive film by direct printing without passing through a photolithography process is excellent in cost and has an advantage that a special facility such as a dark room is not required. The resist may be removed by a general method using an alkali or the like after etching.

  Etching is not particularly limited, but may be chemical etching usually. In typical chemical etching, a component (for example, an acid or an alkali) capable of dissolving the sintered body [or its constituent components, for example, a conductive agent (for example, conductive metal)] is sprayed (for example, a spray method). In many cases, the portion that is not masked (covered) with the etching resist (that is, the sintered body on the non-pattern forming portion) is dissolved and removed. For example, when the conductive metal is copper, it can be efficiently etched with a solution of ferric chloride or cupric chloride.

  As described above, since the conductive paste (B) is often printed along the bulging convex pattern in the second printing step, usually after the etching, on the pattern forming portion. In many cases, a sintered body derived from the conductive paste (B) remains. That is, in the etching step, among the sintered body of the conductive paste (B), the sintered body of the conductive paste (B) formed along the sintered body of the conductive paste (A) on the pattern forming portion. Etching may be performed leaving a portion.

<Pattern substrate and its use>
In this way, a patterned substrate having a conductor pattern formed on the pattern forming portion on the substrate is obtained. The conductor pattern obtained by the method of the present invention has a surface roughness that is small and flat as described above, and a relatively uniform thickness or width. For example, of the width of the conductor pattern (one conductor pattern), the difference between the width of the portion in contact with the substrate and the width of the surface (outermost surface) portion depends on the size of the conductor pattern, but is, for example, 20 μm or less ( For example, 0 to 15 μm), preferably 10 μm or less (for example, 0 to 5 μm), more preferably 5 μm or less (for example, 0 to 3 μm), particularly 1 μm or less (for example, 0 to 0.5 μm). It may be 0 μm.

  Moreover, although the space | interval between conductor patterns can be suitably selected according to a use, For example, 300 micrometers or less (for example, 1-250 micrometers), Preferably it is 200 micrometers or less (for example, 5-150 micrometers), More preferably, it is 100 micrometers or less (for example, 10 to 70 μm), particularly 50 μm or less (for example, 15 to 50 μm). In the present invention, the non-patterned portion can be a sintered body having low adhesion to the substrate, and therefore, the sintered body formed on the non-patterned portion can be removed easily and reliably by etching. Even such a fine pattern does not impair the insulation of the non-pattern forming portion.

  The width (average width) of the conductor pattern may be, for example, 1 μm to 10 mm, preferably 2 μm to 2 mm, more preferably 5 μm to 1 mm, particularly about 10 to 500 μm.

The insulating property (resistance value) of the non-pattern forming portion depends on the type of the substrate, but is, for example, 1 × 10 ⁸ Ω or more (for example, 5 × 10 ⁸ to 1 × 10 ¹⁶ Ω), preferably 1 × 10 ^9. Ω or more (for example, 5 × 10 ⁹ to 1 × 10 ¹⁵ Ω), more preferably 1 × 10 ¹⁰ Ω or more (for example, 5 × 10 ¹⁰ to 1 × 10 ¹⁴ Ω), particularly 1 × 10 ¹¹ Ω or more (for example, 5 × 10 ¹¹ to 1 × 10 ¹³ Ω).

  In the pattern substrate of the present invention, a conductor pattern having high adhesion to the substrate is formed. For example, the peel strength (peel strength per mm) of the conductor pattern with respect to the substrate is 0.5 kgf / mm or more. (For example, 0.55 to 5 kgf / mm), preferably 0.6 kgf / mm or more (for example, 0.65 to 4 kgf / mm), more preferably 0.7 kgf / mm or more (for example, 0.75 to 3 kgf / mm) mm), particularly 0.8 kgf / mm or more (for example, 0.85 to 2.5 kgf / mm), or 1 kgf / mm or more (for example, 1.1 to 2.5 kgf / mm, preferably 1. 2 to 2.2 kgf / mm).

  Since the pattern substrate of the present invention has a pattern having a uniform thickness or width and a smooth or flat surface as described above, the contact area of the pattern upper portion can be increased.

  The conductor pattern may be further plated (electrolytic or electroless plating).

  Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples.

Example 1
Conductive paste 1 (conductive paste for bonding) on a 96% alumina substrate (4 inch square, thickness 0.4 mm), a pattern (not yet) including a comb pattern having a line width of 75 μm and an insulation width of 75 μm, and a 2 mm square pad pattern Printing with a firing pattern). In addition, the conductive paste 1 is borosilicate glass powder (SiO ₂ : 45%, B ₂ O ₃ : 15%, ZnO: 25%, TiO ₂ : 5%, others: 10% with respect to 100 parts by weight of copper powder. ), 15 parts by weight of an organic vehicle in which acrylic resin (polyisobutyl methacrylate, weight average molecular weight: 250,000) is dissolved in terpineol at a ratio of 30% by weight, and the raw materials are integrated by a mortar Thereafter, it was prepared by kneading with three rolls. The screen plate used was a stainless steel # 500 mesh (wire diameter 16 μm) with a photosensitizer applied to a thickness of 10 μm. The squeegee was printed using a urethane squeegee with a hardness of 70 degrees and an attack angle of 70 degrees.

  The insulating width of the comb pattern after printing (the width of the pattern portion) was 50 μm due to the dripping of the paste. The alumina substrate on which the pattern (positive pattern) was printed was dried at 120 ° C. for 20 minutes, and then the conductive paste 2 (conductive paste for etching) was printed on the non-pattern part (negative pattern). The conductive paste 2 contained 15 parts by weight of the organic vehicle with respect to 100 parts by weight of copper powder, and did not contain a glass component. A screen plate having the same specifications as described above and having an opening opposite to the conductor pattern (negative) was used. Similarly, it was dried at 120 ° C. for 20 minutes to obtain a printed board.

  The obtained printed circuit board was baked in a belt-conveying tunnel furnace for 60 minutes including a peak temperature of 900 ° C., a holding time of 10 minutes, and a temperature increase and decrease in a nitrogen atmosphere. After firing, the film thickness was 22 μm at the thickest and 15 μm at the lowest. The substrate after firing was polished in running water with a biaxial buffing machine. The front side was # 400 number (JP TYPE II / JABLO INDUSTRY CO., LTD.) With a non-woven fabric type and a hardness H (HARD) on the front side, and # 800 number (JP TYPE II / JABLO INDUSTRY CO., LTD.) With a hardness H on the back side. . The film thickness became uniform by the planarization, and the thickness became 13 μm.

  A thermosetting resist ink (SPR-081 / manufactured by Kansai Paint Co., Ltd.) was printed in a positive pattern on the flattened substrate, and then dried at 100 ° C. for 10 minutes. Although it is the same in printing the positive pattern as the conductive paste 1, another plate was used because there was a difference in the extent of spreading of the paste. The comb pattern has a line width of 100 μm, a width corresponding to an insulating portion of 50 μm, and the plate specifications are the same. The width corresponding to the insulating part of the printed resist was 40 μm. This was etched with ferric chloride at a liquid temperature of 45 ° C. using a spray etching machine. After cleaning with pure water, the resist was stripped with a 1% aqueous sodium hydroxide solution at 45 ° C., and cleaning with pure water was performed again to obtain an etched substrate. The insulating width formed after etching was 50 μm.

A voltage of 500 V was applied to the insulating part with an ultrahigh resistance microammeter (manufactured by Advantech) whose insulation resistance was evaluated by the comb-shaped pattern part, and the resistance value after 1 minute was read. If it was 1 × 10 ¹⁰ Ω or more, it was determined to have good insulation.

  Adhesion was evaluated with a 2 mm square pad pattern. After soldering φ0.6 tin-plated annealed copper wire along the 2mm square pad surface, the soft copper wire bent vertically upward at the position located at the end of the pad is fixed to a tensile tester, and the pad peels from the substrate Pulled up. The highest load when the pad peeled from the substrate was recorded as peel strength (peel strength of 2 mm pattern). If the peel strength is 1 kgf or more (that is, the peel strength per 1 mm of pattern is 0.5 kgf or more), it is considered that there is good adhesion.

  As an evaluation scale of the cross-sectional shape of the conductor pattern, a value obtained by subtracting the width of the conductor upper surface (surface portion, outermost surface portion) from the width of the conductor pattern lower surface (contact portion with the substrate) in the comb pattern line was used. The respective widths were measured while focusing on the upper and lower surfaces by image measurement with a microscope. Zero (no difference) when there was almost no difference in the width between the upper and lower surfaces and discrimination was impossible. If the difference was 10 μm or less, it was considered good.

  The surface roughness was measured using a roughness meter on the surface of a 2 mm square pad. The measurement method was as defined in JIS. If Ra was 0.3 μm or less, it was determined to be good.

(Example 2)
Example 1 was the same as Example 1 except that the substrate was changed to aluminum nitride.

(Examples 3 and 4)
In Example 1, it carried out similarly to Example 1 except having changed the ratio of the glass of the electrically conductive paste 1 into the ratio shown to a table | surface.

(Example 5)
In Example 1, it carried out similarly to Example 1 except having changed the ratio of the glass of the electrically conductive paste 2 into the ratio shown to a table | surface.

(Example 6)
In Example 1, the same procedure as in Example 1 was performed except that the printing of the conductive paste 2 was changed to solid (full cover) printing instead of negative. In the solid printing, a stainless steel # 400 mesh (wire diameter: 23 μm) with a photosensitive agent applied to a thickness of 10 μm was used. The film thickness after firing was 30 μm at the thickest and 23 μm at the lowest. The film thickness after polishing was 20 μm.

(Example 7)
Example 6 was the same as Example 6 except that the solid printing was changed to twice and the polishing was changed to lapping. The thickness after firing was 45 μm at the thickest and 33 μm at the lowest. Polishing was performed by roughly polishing with a slurry having an abrasive grain size of 2 μm, and then changing to a 0.1 μm slurry and finishing, and the film thickness after polishing was 20 μm.

(Example 8)
In Example 1, buffing (hardness S # 320, hardness S # 1000) is performed in a dry film state after printing to the conductive paste 2 and before baking, and buffing is performed again after baking and before etching. The procedure was the same as in Example 1 except that (one, hardness S # 1000). When the firing was finished, the film thickness was uniform and 15 μm. Re-polishing resulted in a film thickness of 3 μm.

(Comparative Example 1)
In Example 1, after the conductor paste 1 was printed, it was baked as it was, and it was the same as Example 1 except that neither buffing nor etching was performed. The film thickness was 15 μm.

(Comparative Example 2)
After the conductive paste 1 was solid-printed, it was fired, buffed, and etched under the same conditions as in Example 1. The film thickness was 15 μm.

(Comparative Example 3)
In Comparative Example 2, solid printing, baking, buffing, and etching were performed in the same manner as in Comparative Example 2 except that 1 part by weight of the borosilicate glass powder in the conductive paste 1 was used. The film thickness was 15 μm.

  The results are shown in the table.

  As is apparent from the table, in the examples, a conductor pattern excellent in all of adhesion to the substrate, insulation resistance, pattern flatness and smoothness could be obtained. On the other hand, in Comparative Example 1, a flat pattern was not obtained and the smoothness was poor. In Comparative Example 2, since the adhesive layer was likely to remain, the insulation resistance was low, and the bottom of the line remained, so a flat pattern could not be obtained.

  According to the method of the present invention, it is possible to obtain a patterned substrate that is fine and excellent in insulation of a conductor pattern non-formed part. Moreover, since the conductor pattern of such a pattern substrate has a uniform width or thickness and a smooth surface, the conductor pattern surface can be effectively brought into contact with another conductive member. Therefore, the pattern substrate of the present invention can be used for various electronic circuit boards or components, and is particularly suitable for an application for further providing a conductive member (for example, a conductive chip) on the conductor pattern.

  In particular, since the pattern substrate (or its conductor pattern) of the present invention is flat, the bonding strength to a conductive member such as a conductive chip is excellent, and as described above, the portion of the width of the conductor pattern that contacts the substrate The difference between the width of the surface and the width of the surface part is remarkably small, and the surface area of the conductor pattern can be used to the maximum, so heat from the conductive member can be immediately radiated to the board side, and heat dissipation (or thermal conductivity) is also excellent Yes. Therefore, the pattern substrate of the present invention is particularly useful as a substrate (package substrate) for providing a conductive member that requires high heat dissipation (or thermal conductivity) such as an LED chip.

Claims (16)

A method of manufacturing a pattern substrate having a conductor pattern formed on a substrate,
A first printing step of pattern printing the conductive paste (A) on a predetermined pattern portion of the substrate surface;
Second printing step of printing the conductive paste (B) capable of forming a sintered body having lower adhesion to the substrate than the conductive paste (A) between the convex portions of the formed conductive paste (A) When,
A sintering step of sintering the substrate that has undergone the second printing step;
The manufacturing method including the etching process of etching the sintered compact of the electrically conductive paste (B) formed on the non-pattern part except a pattern part among the substrate surfaces.   The conductive paste (A) and the conductive paste (B) contain a conductive metal as a conductive agent, and the conductive paste (A) contains glass, and the glass for the conductive metal constituting the conductive paste (B) The method according to claim 1, wherein the weight ratio of the glass to the conductive metal constituting the conductive paste (A) is larger than the weight ratio.   The proportion of glass in the conductive paste (A) is set to A parts by weight with respect to 100 parts by weight of the conductive metal constituting the conductive paste (A), and the proportion of glass in the conductive paste (B) is defined as conductive. The method according to claim 1 or 2, wherein the value of AB is 0.5 parts by weight or more when B parts by weight with respect to 100 parts by weight of the conductive metal constituting the conductive paste (B).   The ratio of the glass in the conductive paste (A) is 1.5 parts by weight or more with respect to 100 parts by weight of the conductive metal constituting the conductive paste (A), and the glass in the conductive paste (B) The method according to claim 2 or 3, wherein the ratio is 3 parts by weight or less with respect to 100 parts by weight of the conductive metal constituting the conductive paste (B).   The proportion of glass in the conductive paste (A) is set to A parts by weight with respect to 100 parts by weight of the conductive metal constituting the conductive paste (A), and the proportion of glass in the conductive paste (B) is defined as conductive. When B parts by weight with respect to 100 parts by weight of the conductive metal constituting the conductive paste (B), the value of AB is 1 part by weight or more, and the proportion of glass in the conductive paste (A) is: It is 1.8 parts by weight or more with respect to 100 parts by weight of the conductive metal constituting the conductive paste (A), and the proportion of the glass in the conductive paste (B) is the conductivity constituting the conductive paste (B). The method according to claim 1, wherein the amount is 2.5 parts by weight or less based on 100 parts by weight of the conductive metal.   The method according to any one of claims 1 to 5, wherein in the second printing step, the conductive paste (B) is printed in a form of filling between the convex portions of the conductive paste (A).   The method according to claim 1, wherein in the second printing step, the conductive paste (B) is printed so as to cover the convex portions of the conductive paste (A).   The method according to claim 1, wherein the conductive paste (B) is printed a plurality of times in the second printing step.   The method according to any one of claims 1 to 8, further comprising a pre-sintering step of sintering the conductive paste (A) between the first printing step and the second printing step.   The method according to any one of claims 1 to 9, further comprising a preliminary polishing step of polishing the surfaces of the conductive paste (A) and the conductive paste (B) between the second printing step and the sintering step.   The method in any one of Claims 1-10 including the grinding | polishing process of grind | polishing the sintered compact surface of an electrically conductive paste (A) and an electrically conductive paste (B) between a sintering process and an etching process.   The method according to claim 11, wherein the surface roughness Ra of the sintered body surface is set to 0.3 μm or less by the polishing step.   A pattern substrate obtained by the method according to claim 1. Among the widths of the conductor pattern, the difference between the width of the portion in contact with the substrate and the width of the surface portion is 10 μm or less, the interval between the conductor patterns is 100 μm or less, and the resistance value of the non-pattern forming portion is 1 × 10 The pattern substrate according to claim 13, which is ⁹ Ω or more and the peel strength of the conductor pattern with respect to the substrate is 0.5 kgf / mm or more.   The pattern substrate according to claim 13 or 14, wherein plating is further performed on the conductor pattern.   The electronic circuit board or component provided with the pattern board in any one of Claims 13-15.