JP2012119611A - Manufacturing method of through hole electrode substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a through hole electrode substrate which obtains a through hole electrode substrate achieving low material cost and having excellent high frequency property in simple processes and reduces the manufacturing time and the cost significantly.SOLUTION: This invention relates to a manufacturing method of a through hole electrode substrate having through hole electrodes made of a conductive material in through holes in a glass substrate having multiple through holes formed in the thickness direction. The manufacturing method includes: a process in which a fluent conductive composition including metal particles is applied to the glass substrate and the through holes are filled with the conductive composition; and a process in which the conductive composition filling the through holes is heated and the through hole electrode is formed in each through hole.

Description

  The present invention relates to a method for manufacturing a through electrode substrate.

In recent years, in order to connect electrodes (for example, pitch 20 to 50 μm) of IC chips that have been miniaturized and wiring electrodes (for example, pitch 300 to 500 μm) of printed wiring boards, an interposer between them can be used as a silicon substrate. 2. Description of the Related Art A silicon through-electrode substrate has been proposed that has electrodes with corresponding pitches on both the front and back surfaces of a simple semiconductor substrate and that has through electrodes that conduct the electrodes on both sides. An example of such a through electrode substrate is shown in FIG. In this through electrode substrate 10, a plurality of through holes 12 penetrating in the thickness direction are provided in the silicon substrate 11, and an insulating layer 13 such as SiO ₂ is connected to the upper and lower surfaces from the inner wall surface of the through holes 12. (An anti-diffusion layer for the silicon substrate) is formed. A through electrode 14 made of a conductive metal material is embedded in the through hole 12 thus covered with the insulating layer 13.

  For example, the following method has been proposed as a method of forming the through electrode 14. That is, after a seed layer is formed on the lower surface side of the silicon substrate 11 by sputtering, CVD or the like, a conductive material (copper or copper alloy) is filled in the through holes 12 by electrolytic plating using the seed layer as a power feeding layer. To form a conductive portion. Thereafter, unnecessary portions such as the seed layer and the conductive portion are removed by etching, and the formation of the through electrode 14 is completed. (For example, refer to Patent Document 1.)

Also, an insulating layer such as SiO ₂ is formed on the side wall of the non-penetrated via formed in the silicon substrate, and then a conductive paste containing metal particles is filled in the via, and this paste is sintered to form a conductive portion. Then, a method of forming a through via (through electrode) by retreating the back surface of the silicon substrate by polishing or the like has been proposed. (For example, see Patent Document 2.)

However, these through silicon via substrates have the following problems. That is, in order to prevent the metal constituting the through electrode from diffusing into the silicon substrate, it is necessary to provide an insulating layer such as SiO _{2 on} the inner wall of the through hole. There was a problem that it took. In addition, it takes time to perform electrolytic plating, unnecessary portion etching removal, or polishing the back surface of the silicon substrate, the cost of the silicon substrate is high, sufficient high frequency characteristics cannot be obtained, the size of the substrate is limited, and it is difficult to increase the area There were problems such as.

Further, in the method of forming the through electrode 14 described in Patent Document 1, the flatness of the electrolytic plating layer such as copper is not sufficient, and the adhesion at the interface between the insulating layer 13 such as SiO ₂ and the electrolytic plating layer is not sufficient. Therefore, there is a problem peculiar to the conductive layer formed by electrolytic plating, such as the possibility that the electrolytic plating layer may be peeled off by tensile stress. Furthermore, in the silicon through electrode substrate 10 described in Patent Document 1, the insulating layer is caused by a difference in thermal expansion coefficient between SiO ₂ or the like constituting the insulating layer 13 and a conductive material (copper or copper alloy) constituting the through electrode. A large stress was generated in 13 and there was a risk of damage.

JP 2010-171377 A JP 2005-259845 A

  The present invention has been made to solve the above-described problems, and can provide a through electrode substrate having a low material cost and good high-frequency characteristics by a simple process, and has a significantly larger manufacturing time and cost than conventional ones. An object of the present invention is to provide a method of manufacturing a through electrode substrate that can be reduced significantly.

  The through electrode substrate manufacturing method of the present invention is a through electrode substrate manufacturing method having a through electrode made of a conductive material in the through hole of a glass substrate having a plurality of through holes formed in the thickness direction. And applying a fluid conductive composition containing metal particles onto the glass substrate, and filling the conductive composition into the through-hole, and the conductive material filled into the through-hole. The method includes heating the composition to form the through electrode in the through hole.

  In the method for manufacturing a through electrode substrate according to the present invention, the diameter of the through hole is preferably 10 to 200 μm. Moreover, it is preferable that the said fluid conductive composition contains the said metal particle and a solvent at least. The fluid conductive composition may be a metal paste containing at least the metal particles, a resin binder, and a solvent. Furthermore, the metal particles preferably contain at least particles containing copper as a main component.

  In the present specification, “having copper as the main component” means containing copper in a proportion of 90% by mass or more.

  According to the method for manufacturing a through electrode substrate of the present invention, a through electrode substrate based on glass with low material cost and good high frequency characteristics can be obtained in a simple process, reducing manufacturing time and reducing cost. can do. Moreover, since glass is used as the base material, the area can be increased.

It is sectional drawing of the penetration electrode substrate manufactured by one Embodiment of the manufacturing method of this invention. It is sectional drawing which shows the structure of the conventional silicon penetration electrode substrate.

  Embodiments of the present invention will be described below with reference to the drawings. In addition, this invention is limited to the following description and is not interpreted.

  In the method for producing a through electrode substrate of the present invention, a fluid conductive composition containing metal particles is applied onto a glass substrate having a plurality of through holes formed by penetrating both front and back surfaces in the thickness direction. A step of filling the through hole with the conductive composition, and a step of heating the conductive composition thus filled into the through hole to form a through electrode made of a conductive material in the through hole. It has.

  The structure of the through electrode substrate manufactured by the manufacturing method of the present invention is shown in FIG. The through-electrode substrate 1 has a glass substrate 3 having a plurality of through-holes 2 penetrating both front and back surfaces in the thickness direction. The through-hole 2 of the glass substrate 3 has fluidity containing metal particles. A through electrode 4 made of a conductive material formed by applying and filling the conductive composition is heated and further heated.

  According to the method for manufacturing a through electrode substrate of the present invention, a through electrode substrate based on glass with low material cost and good high frequency characteristics can be obtained in a simple process, reducing manufacturing time and reducing cost. can do. Moreover, since glass is used as the base material, the area can be increased.

  Details of members, materials, processes, and the like used in the method for manufacturing a through electrode substrate of the present invention will be described below.

<Glass substrate having a through hole>
Is not particularly limited the composition of glass constituting the substrate, from the viewpoint of transparency to the laser beam to be described later, it is preferable that the silicate glass as a main component SiO _2. In addition to SiO _{2 as} the main component, components such as Al ₂ O ₃ , B ₂ O ₃ , Na ₂ O, and F can be included. Moreover, although the magnitude | size (plane size) and thickness of a glass substrate are not specifically limited, For example, length and width can be 450-600 mm and thickness can be 0.1-0.2 mm.

  The diameter of the through hole of such a glass substrate is preferably 10 to 200 μm from the viewpoint of ease of processing of the glass substrate and processing accuracy. And formation of a through-hole can be performed by irradiation of a laser beam, for example. That is, by irradiating a predetermined portion of the glass substrate with laser light and removing the glass at the irradiated portion by evaporation or ablation, a through-hole penetrating the substrate from the irradiation side surface to the opposite surface is formed. Can do.

As the laser light, an infrared laser such as a CO ₂ laser, an Nd: YAG laser, a laser extending from the near infrared region to the visible region and the ultraviolet region, which combines wavelength conversion with an Nd: YAG laser, or KrF (wavelength: 248 nm). An excimer laser or the like is used. By moving the stage on which the glass substrate is placed linearly and stepwise and irradiating the laser beam every time it is moved, through holes arranged in a one-dimensional manner can be formed. In addition, by adding the movement of the stage in a direction perpendicular to it, a large number of through holes arranged in a two-dimensional array can be formed.

  In forming such a through hole by laser light irradiation, silver is contained in the form of Ag atoms, Ag colloid or Ag ions from the surface of the glass substrate (surface on the irradiation side) to a predetermined depth, and By giving a gradient to the concentration of silver in the thickness direction, it is possible to relieve stress due to heat during drilling with laser light. And the glass substrate which prevents a crack and a chip | tip of glass, and has a favorable through-hole can be obtained.

  As a means for introducing silver so as to have a concentration gradient in the thickness direction in the glass substrate, for example, by immersing the glass substrate in a molten salt containing Ag ions, other than Ag ions in the glass. It is conceivable to perform ion exchange between monovalent cations and Ag ions. In addition, when the silver concentration is low, the absorption energy of the laser light is also low, and evaporation and ablation are less likely to occur. Therefore, the silver concentration in the portion scheduled for processing is preferably 0.1 mol% or more.

<Flowable conductive composition containing metal particles>
A metal paste can be used as the fluid conductive composition containing metal particles that are applied onto a glass substrate and filled into the through holes. The metal paste is described below.

(Metal paste)
The metal paste contains at least metal particles and a resin binder, and further contains a solvent in order to improve the workability of coating and filling by adjusting to an appropriate viscosity.

  Examples of the metal particles include known conductive metal particles. Specific examples include particles mainly composed of gold, silver, copper, palladium, nickel, tin, aluminum, bismuth, indium, lead, etc. From the viewpoint of conductivity, migration resistance, price, etc. The particles as the main component (hereinafter referred to as copper particles) are preferred. The shape of the metal particles is not particularly limited, and may be any of a spherical shape, a needle shape, an elliptical shape, a flat shape, and the like. Further, the metal particles may be any of primary particles, aggregated particles, and particles in which primary particles and aggregated particles are combined. The average particle diameter of the metal particles is 0.3 to 20 μm, and more preferably 1 to 10 μm. When the average particle size of the metal particles is in the range of 0.3 to 20 μm, the fluidity of the obtained metal paste is good, the workability of coating and filling into the through holes is good, and the metal paste penetrates. The through electrode formed in the hole has sufficient conductivity. Here, the average particle diameter of the metal particles is obtained by measuring and averaging the Feret diameters of 100 particles randomly selected from a scanning electron microscope (SEM) image or a transmission electron microscope (TEM) image. It is assumed that it is calculated by

  When the metal particles are copper particles, copper particles having an average primary particle size of 0.3 to 20 μm and copper particles having an average aggregate particle size of 10 to 100 nm, preferably 50 to 80 nm, are contained in the paste. The conductivity of the through electrode can be improved by adding and fusing the copper particles together by utilizing the surface melting phenomenon of the copper fine particles.

  Here, the copper fine particles are mainly composed of copper and further contain other elements such as hydrogen and oxygen, but from the point of being able to form a highly conductive through electrode, copper hydride fine particles or metal copper fine particles are preferable, Copper hydride fine particles are particularly preferred. Copper hydride is a compound containing hydrogen in addition to copper as an element. The hydrogen atom is present in a state of being bonded to a copper atom and has a property of decomposing into metallic copper and hydrogen at 60 to 100 ° C.

As a manufacturing method of copper fine particles, the wet reduction method provided with the following process (a)-(d) can be mentioned, for example.
(A) A step of preparing an aqueous solution containing copper ions by dissolving a water-soluble copper compound in water.
(B) A step of heating an aqueous solution containing copper ions to 30 ° C. or higher and reducing copper ions with hypophosphorous acid to produce copper hydride fine particles or, in some cases, metal copper fine particles.
(C) A step of thermally decomposing the copper hydride fine particles to produce metal copper fine particles as necessary.
(D) The process of refine | purifying the obtained copper microparticles as needed.

Step (a)
Examples of the water-soluble copper compound include copper sulfate, copper nitrate, copper formate, copper acetate, copper chloride, copper bromide, copper iodide and the like. As for the density | concentration of a water-soluble copper compound, 0.1-30 mass% of the whole aqueous solution is preferable. If the density | concentration of the water-soluble copper compound in aqueous solution is 0.1 mass% or more, the quantity of water will be restrained and the production efficiency of copper particulates will become favorable. If the density | concentration of the water-soluble copper compound in aqueous solution is 30 mass% or less, the fall of the yield of a copper fine particle will be suppressed.

Step (b)
Copper ions in the aqueous solution are reduced under acidic conditions by hypophosphorous acid at a temperature of 30 ° C. or higher, and copper hydride fine particles gradually grow to form copper hydride fine particles having an average particle diameter of 10 to 100 nm. To do. Further, when the reaction is allowed to proceed for a certain time or more, metallic copper is generated by the decomposition of copper hydride. 30-80 degreeC is preferable and, as for the temperature of the aqueous solution in a process (b), 35-60 degreeC is more preferable. If the temperature of aqueous solution is 80 degrees C or less, the change of the reaction system by water evaporation can be suppressed.

  Hypophosphorous acid is preferably added as an aqueous solution. The concentration of hypophosphorous acid is preferably 30 to 80% by mass and more preferably 40 to 60% by mass in 100% by mass of the aqueous solution. If the concentration of hypophosphorous acid in the aqueous solution is 30% by mass or more, the amount of water can be suppressed. If the concentration of hypophosphorous acid in the aqueous solution is 80% by mass or less, a rapid reaction can be suppressed.

  The addition amount of hypophosphorous acid is preferably 1.5 to 10 times equivalent to copper ions. If the addition amount of hypophosphorous acid is 1.5 times equivalent or more with respect to copper ions, the reducing action is sufficient. If the addition amount of the reducing agent is 10 times equivalent or less with respect to copper ions, the adverse effect of the remaining phosphorus can be suppressed.

Step (c)
If necessary, the obtained copper hydride fine particles are thermally decomposed to produce metal copper fine particles. Thermal decomposition is performed in an inert atmosphere. The oxygen concentration in the atmosphere is preferably 1000 ppm or less. When it exceeds 1000 ppm, cuprous oxide will be produced by oxidation. The temperature of thermal decomposition is preferably 60 to 100 ° C, more preferably 70 to 90 ° C. If temperature is 60 degreeC or more, thermal decomposition will advance smoothly. If the temperature is 100 ° C. or lower, the fusion of copper fine particles can be suppressed.

Step (d)
You may refine | purify the obtained copper microparticles as needed. Examples of the purification method include a method of dispersing in water.

  1-40 mass parts is preferable with respect to 100 mass parts of copper particles with an average particle diameter of 0.3-20 micrometers mentioned above, and, as for the compounding quantity of the copper fine particle manufactured in this way, 5-25 mass parts is more preferable. If the amount of the copper fine particles is 1 part by mass or more, it is easy to sinter on the surface of the copper particles, and by increasing the number of conductive paths between the copper particles, it is possible to contribute to improving the conductivity of the obtained through electrode. If the amount of copper fine particles is 40 parts by mass or less, the flow characteristics of the resulting metal paste will be good.

  Examples of the resin binder contained in the metal paste together with such metal particles containing copper fine particles include known resin binders (such as thermosetting resins and thermoplastic resins) that are usually used in metal pastes.

  Thermosetting resins include phenolic resin, epoxy resin, unsaturated polyester, vinyl ester resin, diallyl phthalate resin, oligoester acrylate resin, xylene resin, bismaleidotriazine resin, furan resin, urea resin, polyurethane resin, melamine resin, Silicon resin, acrylic resin, oxetane resin, oxazine resin and the like can be mentioned, and pheno resin, epoxy resin and oxazine resin are preferable. Among these, it is preferable to select and use a resin that can be sufficiently cured at the heating temperature. Examples of the thermoplastic resin include polyamide resin, polyimide resin, acrylic resin, ketone resin, polystyrene resin, and polyester resin. Among these, it is preferable to select and use a resin that does not undergo modification or deterioration at the temperature during heating and has a sufficient Tg (glass transition point) to maintain the shape after the through electrode is formed.

  The content of the resin binder in the metal paste is appropriately selected according to the ratio between the total volume of the metal particles (including copper fine particles when copper fine particles are included) and the voids existing between the particles. do it. Usually, 5-50 mass parts is preferable with respect to 100 mass parts of metal particles, and 5-20 mass parts is more preferable. When the amount of the resin binder is 5 parts by mass or more, the flow characteristics of the obtained metal paste are good. When the amount of the resin binder is 50 parts by mass or less, the conductivity of the obtained through electrode is good.

  Examples of the solvent contained in the metal paste include diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl acetate, propylene glycol monoethyl ether, and propylene glycol monoethyl acetate. The content of the solvent is appropriately adjusted according to the content of the metal particles and the resin binder. That is, by adjusting the content of the solvent in accordance with the content of the metal particles and the resin binder, etc., the viscosity of the metal paste is adjusted to a range in which the workability of coating and filling is good.

  The metal paste may contain a known additive as long as it does not impair the effects of the present invention. As the additive, a leveling agent, a coupling agent, a viscosity modifier, an antioxidant and the like can be used.

  By using a metal paste configured in this way as a fluid conductive composition containing metal particles that are applied onto a glass substrate and filled into the through-holes, the through-holes have sufficient conductivity. A through electrode can be formed. Moreover, the through electrode formed of the metal paste has a high adhesive strength between the base glass and the resin binder contained in the paste. Furthermore, since the stress generated due to the difference in thermal expansion coefficient between the glass of the substrate and the metal contained in the through electrode is alleviated by the elasticity of the resin binder, a large amount of heat is generated on the inner wall surface (glass) of the through hole. No stress is applied and the occurrence of cracks and the like is prevented.

  In the present invention, as the fluid conductive composition containing metal particles, a metal ink can be used instead of the metal paste. The metal ink is described below.

(Metal ink)
The metal ink is made of a dispersion liquid in which metal fine particles are dispersed in a liquid, and contains at least metal fine particles and a solvent.

  Examples of the metal fine particles include known conductive metal fine particles. Specific examples include fine particles mainly composed of metals such as gold, silver, copper, platinum, palladium, tungsten, nickel, tantalum, bismuth, lead, indium, tin, titanium and aluminum. Here, the metal fine particles include not only the metal fine particles themselves but also hydrogenated metal fine particles. From the viewpoint of conductivity, migration resistance, price, etc., copper fine particles are preferred.

  The metal fine particles usually exist as aggregated particles in which primary particles having an average particle diameter of about 1 to 20 nm are aggregated. The average particle diameter (average aggregate particle diameter) of the metal fine particles is 1 to 100 nm, and more preferably 5 to 30 nm. If the average particle diameter of the metal fine particles is within the above range, the phenomenon that the apparent melting point of the nano-sized particles falls can be used. Therefore, even when the temperature for heating the conductive composition is as low as 100 to 300 ° C. as described later, there is an advantage that the volume resistivity of the obtained through electrode can be reduced. Here, the average particle diameter of the metal fine particles is calculated by measuring and averaging the Feret diameters of 100 particles randomly selected from the TEM image.

  As the metal fine particles, copper fine particles produced by a wet reduction method including the steps (a) to (d) described above can be used. Also, hydride fine particles of copper, nickel, ruthenium or palladium having an average agglomerated particle size of 100 nm or less produced by the method described below can be used. Since these metal hydride fine particles exist in a state in which metal atoms and hydrogen atoms are bonded together, they are less susceptible to oxidation in the air atmosphere than the metal fine particles themselves, are stable, and have excellent storage stability. As the hydride fine particles, hydride fine particles of copper or nickel are particularly preferable because a conductive material having a low electric resistance value can be obtained.

Copper hydride fine particles can be obtained, for example, by a wet reduction method including the following steps (A) to (C).
(A) The process of adding water to the water-soluble compound of copper, and obtaining the aqueous solution containing a copper ion.
(B) A step of adjusting the pH to 3 or less by adding an acid to an aqueous solution containing copper ions.
(C) A step of adding a protective agent and a water-insoluble organic liquid to an aqueous solution adjusted to pH 3 or lower.
(D) A step of adding a reducing agent while stirring to reduce copper ions in the aqueous solution to produce copper hydride fine particles.

Process (A)
Examples of the water-soluble copper compound include copper sulfate, copper nitrate, copper acetate, copper chloride, copper bromide, copper iodide and the like. The concentration of the water-soluble copper compound is preferably 0.1 to 30% by mass in 100% by mass of the aqueous solution. When the concentration of the water-soluble copper compound in the aqueous solution is less than 0.1% by mass, a large amount of water is required, and the production efficiency of the resulting hydride fine particles is reduced. If the concentration is more than 30% by mass, the aggregation stability of the hydride fine particles obtained is lowered, which is not preferable.

Process (B)
As the acid for adjusting the pH, citric acid, maleic acid, malonic acid, acetic acid, propionic acid, sulfuric acid, nitric acid, hydrochloric acid and the like are preferable. In addition, citric acid, maleic acid, and malonic acid are particularly preferable because they form a stable complex with copper ions to prevent adsorption of hydrated water onto the copper ions. By setting the pH of the aqueous solution to 3 or less, copper ions in the aqueous solution are easily obtained as copper hydride fine particles due to the action of a reducing agent added in a subsequent step. A pH exceeding 3 is not preferable because copper hydride fine particles cannot be obtained. Since the hydride fine particles can be generated in a short time, the pH is particularly preferably 1 to 2.

Process (C)
As the reducing agent, a metal hydride or hydride reducing agent is preferable because of its large reducing action. Examples of the metal hydride that can be used as the reducing agent include lithium hydride, potassium hydride, calcium hydride and the like. Examples of the hydride reducing agent include lithium aluminum hydride, lithium borohydride, and sodium borohydride. Of these, lithium aluminum hydride, lithium borohydride, and sodium borohydride are particularly preferable.

  Such a reducing agent is preferably added in an equivalent number of 1.5 to 10 times that of copper ions. When the addition amount of the reducing agent is less than 1.5 times equivalent to the copper ion, the reducing action is not sufficient, and when the amount exceeds 10 times equivalent, the aggregation stability of the obtained copper hydride fine particles decreases. Therefore, it is not preferable.

  Moreover, before adding a reducing agent, it is preferable to add the protective agent shown below to the aqueous solution containing a copper ion. Since the added protective agent coats the surface of the copper hydride fine particles obtained by reduction so as to coordinate, the copper hydride fine particles in the dispersion (ink) are hardly oxidized. Moreover, there exists an effect which prevents aggregation of copper hydride microparticles | fine-particles.

  The protective agent is at least one selected from an amino group, an amide group, a sulfanyl group (—SH), a sulfide type sulfanediyl group (—S—), a hydroxyl group, a carboxyl group, a carbonyl group, and an ether type oxy group. An organic compound having 4 to 100 carbon atoms and having the following group can be used. If the carbon number is less than 4, the aggregation stability of the obtained copper hydride fine particles in the dispersion may be insufficient. Further, when the carbon number is more than 100, when the through electrode is obtained by firing, carbon remains in the ink deposit and the volume resistivity tends to increase. Since thermal stability is good, vapor pressure is moderate, and handling properties are good, those having 4 to 20 carbon atoms are preferred, and those having 8 to 18 carbon atoms are particularly preferred.

  In addition, the organic compound having 4 to 100 carbon atoms, which is a protective agent, may be either saturated or unsaturated, and is preferably a chain and particularly preferably a straight chain. Further, the protecting agent is composed of an amino group, an amide group, a sulfanyl group (—SH), a sulfide type sulfanediyl group (—S—), a hydroxyl group, a carboxyl group, a carbonyl group, and an ether type oxy group in the molecule. Although it has one or more selected groups, the more these groups are in the molecule, the more preferable it is because it can be more strongly coordinated and coated with the copper hydride fine particles. These groups may be located at any position in the molecule, but those at the terminal are particularly preferred.

  Furthermore, these protective agents do not desorb from the copper hydride fine particles in the normal storage environment temperature range, and when firing, it is necessary to quickly desorb from the surface of the metal fine particles, Those having a boiling point of 60 to 300 ° C are preferred, and those having a boiling point of 100 to 250 ° C are particularly preferred.

  Among the protective agents, organic compounds containing an amino group or an amide group include octylamine, decylamine, dodecylamine, tetradecylamine, hexadecylamine, stearylamine, oleylamine, benzylamine, stearylamide, oleylamide, and the like. It is done. Examples of the organic compound containing a sulfanyl group or a sulfide-type sulfanediyl group include decanethiol, dodecanethiol, trimethylbenzyl mercaptan, butylbenzyl mercaptan, and hexyl sulfide. Organic compounds containing hydroxyl group, carboxyl group, carbonyl group, ether type oxy group include dodecanediol, hexadecanediol, dodecanoic acid, stearic acid, oleic acid, linoleic acid, linolenic acid, dodecanedione, dibenzoylmethane, ethylene Glycol monodecyl ether, diethylene glycol monodecyl ether, triethylene glycol monodecyl ether, tetraethylene glycol monodecyl ether, ethylene glycol monododecyl ether, diethylene glycol monododecyl ether, triethylene glycol monododecyl ether, tetraethylene glycol monododecyl ether, ethylene Examples include glycol monocetyl ether and diethylene glycol monocetyl ether. Among these, compounds having an amino group such as octylamine, decylamine, dodecylamine, tetradecylamine, hexadecylamine, stearylamine, oleylamine or benzylamine can particularly efficiently recover copper ions from the water layer to the oil layer. Preferably, decylamine, dodecylamine, tetradecylamine or hexadecylamine is most preferred.

  Although the addition amount of such a protective agent is suitably selected according to the use of the metal ink to be used, it is preferable to add 5 to 300 parts by mass with respect to 100 parts by mass of the copper hydride fine particles.

  The metal ink contains a water-insoluble organic solvent as a medium in the dispersion together with such metal fine particles. As the water-insoluble organic solvent, known solvents for metal inks can be mentioned. In the step of forming the through electrode, heating is performed after application of the metal ink so that it does not evaporate relatively quickly and causes thermal decomposition. Those having thermal stability are preferred. In particular, when the copper hydride fine particles produced by the above method are used as the metal fine particles, those having low affinity and good affinity with the protective agent for coating the surface of the copper hydride fine particles are preferable. Examples of such an organic solvent include 1 selected from hexane, heptane, octane, decane, dodecane, tetradecane, decene, dodecene, tetradecene, cyclohexane, cyclooctane, dipentene, terpene, terpineol, xylene, toluene, ethylbenzene, and mesitylene. The above can be used.

  The addition amount of the organic solvent is appropriately selected depending on the use of the ink to be used, but it is preferable to add 20 to 270 parts by mass with respect to 100 parts by mass of the metal fine particles. The concentration of the metal fine particles in the metal ink is preferably 5 to 60% by mass, particularly preferably 10 to 50% by mass, based on the total amount of the ink. When the concentration of the metal fine particles is less than 5% by mass, it is not preferable because the thickness of the ink deposit after firing is not sufficiently obtained and the conductivity of the obtained through electrode may be lowered. In addition, if the concentration of the metal fine particles is more than 60% by mass, ink characteristics such as ink viscosity and surface tension may be deteriorated and it may be difficult to use as ink.

  Additives, resin binders, and the like can be appropriately added to the metal ink depending on the application.

<Formation of through electrode>
In order to form a through electrode using a metal paste, the metal paste is applied on a glass substrate and filled in the through hole, and then the filled metal paste layer is heated to be included in the metal paste layer. In the case of using a thermosetting resin as a resin binder, a method of further curing the resin is employed. Examples of the coating method include known methods such as screen printing, roll coating, air knife coating, blade coating, bar coating, gravure coating, die coating, and slide coating. “I apply metal paste on the glass substrate and fill it in the through hole” means (i) apply metal paste on the entire surface of the glass substrate and fill it in the through hole (apply to the surface of the glass substrate). The metal paste is removed later), (ii) applying the metal paste to the glass substrate through a mask, (iii) supplying the metal paste only to the through-hole using a dispenser, etc. However, it is not limited to these.

  Examples of the heating method include hot air heating and heat radiation heating. What is necessary is just to determine a heating temperature and a heating time suitably according to the characteristic calculated | required by the penetration electrode. The heating temperature is preferably 100 to 300 ° C. If the heating temperature is within this range, the sintering of the metal particles tends to proceed while suppressing the oxidation of the metal particles. In addition, curing can proceed sufficiently and the solvent can be volatilized without changing the temperature of the resin binder at a high temperature, so that the electrical conductivity is high and the adhesiveness with the inner wall surface of the through hole is good and the thermal stress is low. A through electrode having a high relaxation property can be formed.

  In order to form a through electrode with a metal ink, the metal ink is applied on a glass substrate, heated and dried, an ink deposited layer filled in the through hole is formed, and then the ink deposited layer is heated. A method of firing is adopted. As the application method, ink-jet printing, screen printing, roll coating method, air knife coating method, blade coating method, bar coating method, gravure coating method, die coating method, slide coating method, and quantitative using dispenser (liquid dispensing device) Well-known methods, such as a supply method, are mentioned. “Applying metal ink on glass substrate” means (i) applying metal ink to the entire surface of the glass substrate and filling the through holes (the metal ink applied to the surface of the glass substrate is removed later) Or (ii) apply metal ink to the glass substrate through a mask, or (iii) supply metal ink only to the through-hole using a dispenser or the like. I can't.

  In order to fill the through hole of the glass substrate with the deposited layer of the metal ink, the following method can be employed. That is, the metal ink coating layer formed on the glass substrate is sucked from the lower surface side of the glass substrate through the through hole, and the metal ink coating layer is drawn into the through hole by this suction force. Next, the metal ink layer thus drawn into the through hole is dried, and the dried material is adhered and deposited on the inner wall surface of the through hole. Then, the ink application, suction, and drying operations are repeated to fill the through hole with a deposited layer of metal ink.

  Examples of a method for heating the deposited layer of the metal ink filled and formed in the through hole in this way include methods such as hot air heating and heat radiation heating. What is necessary is just to determine a heating temperature and a heating time suitably according to the characteristic calculated | required by the penetration electrode. By heating, metal fine particles in the metal ink deposition layer are fused to form a bulk body, and a through electrode having sufficient conductivity can be obtained.

  Next, specific examples of the present invention will be described. The present invention is not limited to these examples. In the following examples, “%” means mass% unless otherwise specified.

Example 1
First, a glass substrate having a through hole was produced. Thickness is 0.3 mm, thermal expansion coefficient is 38 × 10 ⁻⁷ / K, SiO ₂ is 60% by mass, Fe is 0.05% by mass in terms of oxide of Fe ₂ O ₃ , and the total of Na and K A plate glass (AN100, manufactured by Asahi Glass Co., Ltd.) having a content of less than 0.1% by mass in terms of oxide was placed on the stage and placed on the optical path of excimer laser light. In the vicinity of the center of a stainless plate having a length of 30 mm, a width of 30 mm, and a thickness of 0.5 mm, a mask having a diameter of 40 μm and a distance between the center points of adjacent holes of 0.6 mm and 16 × 40 length and width was prepared. . Using a projection lens, the projection lens, mask, and plate glass were arranged so that the mask pattern reduced to 1/10 was projected onto the plate glass. Excimer laser light was irradiated to the processed surface of the plate glass. The through-hole was formed by adjusting the irradiation fluence to 5 J / cm ² and irradiating 3900 shots.

  In a polyethylene container, 15 g of a phenolic resin diethylene glycol monoethyl ether solution (product name: PL-5208, manufactured by Gunei Chemical Co., Ltd.) and 3 g of diethylene glycol monoethyl ether were uniformly mixed, and then the average primary particle was added to the mixture. 82 g of copper particles having a diameter of 7 μm (trade name AFS-Cu, manufactured by Nippon Atomizing Co., Ltd.) were added. Next, the mixture was kneaded at 2000 rpm for 5 minutes using a stirrer (ARE-310, manufactured by Shinky Corporation) to obtain a copper paste.

  Next, the copper paste obtained in this way is screen-printed through a metal mask on one surface (surface on the laser light irradiation side) of the glass substrate having the through hole (diameter 40 μm) obtained by the above method, and penetrated. The holes were filled. After that, the phenolic resin contained in the copper paste is cured by placing the glass substrate filled with the copper paste in the through hole in a drying furnace preheated to 150 ° C. and heating in air at 150 ° C. for 30 minutes. I let you.

  The glass substrate thus obtained was cut perpendicularly to the main surface, and the cross section was observed by SEM. The phenolic resin, which is a thermosetting resin, was cured by heating the copper paste in the through hole of the glass substrate. It was confirmed that the conductive cured product was filled without any gaps. Further, when the conductivity of the conductive cured material filled in the through holes of the glass substrate was examined by a conventional method, it was confirmed that the conductive cured product had sufficient conductivity. Moreover, generation | occurrence | production of a crack, a crack, and a chipping were not observed in the glass substrate.

Example 2
In a glass container, 5 g of copper (II) chloride dihydrate was dissolved in 150 g of distilled water to obtain an aqueous solution containing copper ions. The pH of the obtained aqueous solution was 3.4. To this aqueous solution, 90 g of 40% aqueous citric acid solution was added and stirred for a while. Next, 150 g of a 3% sodium borohydride aqueous solution was slowly added dropwise to the aqueous solution while adding a solution obtained by mixing 5 g of dodecylamine and 10 g of xylene and stirring vigorously. After completion of dropping, the mixture was allowed to stand for 1 hour to separate into an aqueous layer and an oil layer, and then only the oil layer was collected and concentrated to obtain black ink in which fine particles were dispersed. When the fine particles in the ink were collected and identified by X-ray diffraction, it was confirmed to be copper hydride.

  Next, using the copper fine particle-containing ink thus obtained, a conductive fired product was formed in the through hole of the glass substrate as shown below. First, a glass substrate having a through hole (diameter 40 μm) obtained in the same manner as in Example 1 is placed on a stage (a porous chuck manufactured by Yoshioka Seiko Co., Ltd.) configured to be suckable from the lower portion, and then the glass substrate. An ink containing copper fine particles was applied to the upper surface of the glass substrate from above by a dispensing method, and the ink applied on the glass substrate was drawn into the through-hole by a suction force from below.

  Thereafter, the glass substrate was placed in a drying furnace in a nitrogen atmosphere and held at 50 ° C. for 30 minutes to dry the copper fine particle-containing ink layer drawn into the through hole. By drying, an ink deposition layer containing copper fine particles was formed to adhere to the inner wall surface of the through hole. Subsequently, this ink application, suction drawing, and drying operations were repeated to form a copper fine particle-containing deposited layer so as to fill the through hole without any gaps.

  Thereafter, the glass substrate filled with the copper fine particle-containing deposited layer in this way was placed in a firing furnace in a nitrogen atmosphere and heated at 150 ° C. for 60 minutes to fire the copper fine particle-containing deposited layer.

  When the glass substrate thus obtained was cut perpendicularly to the main surface and the cross section was observed with a scanning electron microscope (SEM), the sintered product of the copper fine particle-containing ink was filled in the through holes of the glass substrate without any gaps. It was confirmed that Further, when the conductivity of the fired product of the ink filled in the through hole of the glass substrate was examined by a conventional method, it was confirmed that the ink had sufficient conductivity. Moreover, generation | occurrence | production of a crack, a crack, and a chipping were not observed in the glass substrate.

  According to the present invention, it is possible to obtain a through electrode substrate based on glass with low material cost and good high-frequency characteristics by a simple process, thereby shortening the manufacturing time and reducing the cost. Moreover, since glass is used as the base material, the area can be increased. The through electrode substrate obtained by the present invention can be suitably used as an interposer for connecting an IC chip and a wiring board such as a printed wiring board.

DESCRIPTION OF SYMBOLS 1 ... Through-electrode board | substrate, 2 ... Through-hole, 3 ... Glass substrate, 4 ... Through-electrode.

Claims (5)

In the through hole of the glass substrate having a plurality of through holes formed in the thickness direction, a method for producing a through electrode substrate having a through electrode made of a conductive material,
Applying a flowable conductive composition containing metal particles on the glass substrate, and filling the through hole with the conductive composition;
A method of manufacturing a through electrode substrate, comprising: heating the conductive composition filled in the through hole to form the through electrode in the through hole.   The method of manufacturing a through electrode substrate according to claim 1, wherein the through hole has a diameter of 10 to 200 μm.   The method for producing a through electrode substrate according to claim 1, wherein the fluid conductive composition contains at least the metal particles and a solvent.   The method for manufacturing a through electrode substrate according to claim 3, wherein the fluid conductive composition is a metal paste containing at least the metal particles, a resin binder, and a solvent.   The said metal particle is a manufacturing method of the penetration electrode substrate of any one of Claims 1-4 containing the particle | grains which have copper as a main component at least.

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