JP2008031005A - Multilayered ceramic substrate and composite green sheet for manufacturing multilayered ceramic substrate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain excellent high frequency dielectric characteristics and a high Q value in high frequency regions for a multilayered ceramic substrate which is manufactured by locating, between basic material layers containing a glass material and a first ceramic material, a constraint layer that contains a second ceramic material which can not be substantially sintered at the temperature where the basic material layers are sintered, by penetrating the glass material contained in the basic material layers into the constraint layer while preventing the contraction of the basic material layers by the constraint layer during firing, and by compacting the constraint layer. <P>SOLUTION: The basic material layers 2 contain a first ceramic material composed of 15-75 wt.% of a glass material and 25-85 wt.% of a first ceramic material. The glass material contains 33-68 mole% of SiO<SB>2</SB>, 3-52 mole% of CaO, 1-36 mole% of Al<SB>2</SB>O<SB>3</SB>and 1-25 mole% of B<SB>2</SB>O<SB>3</SB>, and as the first ceramic material MgAl<SB>2</SB>O<SB>4</SB>is used. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a multilayer ceramic substrate and a composite green sheet for producing a multilayer ceramic substrate, and more particularly to a multilayer ceramic substrate and a composite green sheet for producing a multilayer ceramic substrate produced by applying a so-called non-shrink process.

  As a multilayer ceramic substrate which is interesting for the present invention, for example, there is one described in JP 2000-25157 A (Patent Document 1). In Patent Document 1, a composite laminate and a manufacturing method thereof by a so-called non-shrinking process, more specifically, it can be manufactured while suppressing shrinkage due to firing, and can be used as it is in a state after firing. As a preferred typical example, a multilayer ceramic substrate having the following structure and a method for manufacturing the same are disclosed.

  That is, the multilayer ceramic substrate includes a base material layer formed of an aggregate of a first powder containing a glass material and a first ceramic material, and a second ceramic that is not sintered at a temperature at which the glass material can be melted. And a constraining layer including a second powder aggregate including the material. Here, at least a part of the first powder is in a sintered state. On the other hand, although the second powder is in an unsintered state, a part of the first powder containing the glass material is fixed to each other by diffusing or flowing into the constraining layer.

  In order to manufacture such a multilayer ceramic substrate, a raw substrate layer containing the above-mentioned first powder and a constraining layer in a raw state containing the above-mentioned second powder A raw laminate is prepared, which is then fired. In this firing step, at least a part of the first powder is sintered. In this firing step, a part of the first powder, typically a part of the glass material contained in the first powder, diffuses or flows into the constraining layer. As a result, the second powder is not sintered, but is fixed to each other by a part of the first powder, particularly a glass material.

  According to the manufacturing method as described above, since the second powder is not sintered in the firing step, the constraining layer containing the second powder acts so as to suppress the shrinkage of the base material layer, and is fired. The shrinkage | contraction as the whole multilayer ceramic substrate by can be suppressed, As a result, the dispersion | variation in the dimension of the obtained multilayer ceramic substrate can be reduced. Further, in the obtained multilayer ceramic substrate, the second powder included in the constraining layer is fixed to each other as a part of the first powder including the glass material diffuses or flows into the constraining layer. Thus, there is no need to remove the constraining layer later.

However, in the technique described in Patent Document 1 described above, depending on the combination of the first ceramic material as the filler and the glass material contained in the base material layer, the first ceramic material and the glass material may be used during firing. This may cause a problem that the dielectric loss is large and the Q value is low, particularly in a high frequency region.
JP 2000-25157 A

  Accordingly, an object of the present invention is to provide a multilayer ceramic substrate that can solve the above-described problems.

  Another object of the present invention is to provide a composite green sheet for producing a multilayer ceramic substrate, which is used for producing the multilayer ceramic substrate described above.

  According to the present invention, a plurality of stacked base material layers configured by an aggregate of first powders including a glass material and a first ceramic material, and at least one main surface thereof are in contact with the base material layer. And a constraining layer comprising a second powder aggregate including a second ceramic material that is substantially not sintered at a temperature at which the base material layer is sintered. At least a part of the powder is in a sintered state, and the second powder is fixed to each other when a part of the first powder containing the glass material diffuses or flows into the constraining layer. First, it is directed to a multilayer ceramic substrate, and is characterized by having the following configuration in order to solve the technical problems described above.

That is, in the base material layer, the first powder includes 15 to 75% by weight of the glass material and 25 to 85% by weight of the first ceramic material. Then, the glass material, from 33 to 68 mol% of _SiO 2, 3 to 52 mol% of CaO, comprises 1 to 36 mol% of _Al 2 _{O 3} and 1 to 25 mole% _B 2 _{O 3,} the first The ceramic material is characterized by being MgAl ₂ O ₄ .

In the constraining layer, the second ceramic material is preferably any one of MgAl ₂ O ₄ , Al ₂ O _3, and ZrO ₂ , and more preferably MgAl ₂ O ₄ .

  The multilayer ceramic substrate according to the present invention preferably further comprises a conductor film formed along at least one main surface of the base material layer and the constraining layer.

  In the multilayer ceramic substrate according to the present invention, a part of the glass material contained in the base material layer is diffused or flows throughout the constraining layer, and all of the second powder is a part of the glass material. Are preferably fixed to each other.

  The constraining layer is preferably thinner than the base material layer.

  The present invention is also directed to a composite green sheet for producing a multilayer ceramic substrate, which is used for producing a multilayer ceramic substrate as described above.

A composite green sheet for producing a multilayer ceramic substrate according to the present invention includes a base material layer in a raw state containing a glass material and a first powder containing a first ceramic material, and at least one main surface thereof. A constraining layer in a raw state, comprising a second powder comprising a second ceramic material positioned in contact with the material layer and not substantially sintered at a temperature at which the substrate layer sinters ing. The first powder includes 15 to 75% by weight of a glass material and 25 to 85% by weight of the first ceramic material, and the glass material includes 33 to 68 mol% of SiO2, ₃ to 52 mol. % CaO, 1-36 mol% Al ₂ O ₃ and 1-25 mol% B ₂ O ₃ , characterized in that the first ceramic material is MgAl ₂ O ₄ .

  The composite green sheet for producing a multilayer ceramic substrate according to the present invention is such that the base material is in contact with both main surfaces of the constraining layer even if the constraining layer is disposed so as to contact both main surfaces of the base material layer. A layer may be disposed.

According to the multilayer ceramic substrate according to the present invention, the first powder constituting the base material layer includes 15 to 75% by weight of the glass material and 25 to 85% by weight of the first ceramic material. as a glass material contained in the substrate layer comprises from 33 to 68 mol% of _SiO 2, 3-52 mol% of CaO, _Al 2 _{O 3} and 1 to 25 mole% _B 2 _{O 3} of 1 to 36 mol% Since the composition is used and MgAl ₂ O ₄ is used as the first ceramic material contained in the same base material layer, the reaction between the glass material and the first ceramic material is suppressed during firing, and the high frequency region , The increase in dielectric loss can be suppressed and the Q value can be kept high.

  In addition, according to the present invention, the constraining layer containing the second powder acts so as to suppress the shrinkage of the base material layer, and the shrinkage of the entire multilayer ceramic substrate due to the firing can be suppressed. In the obtained multilayer ceramic substrate, undesired deformation can be suppressed and variation in dimensions can be reduced. The second powder contained in the constraining layer is fixed to each other by diffusing or flowing a part of the first powder containing the glass material into the constraining layer, so that the constraining layer is removed later. Therefore, it can be used as it is.

In the multilayer ceramic substrate according to the present invention, when the second ceramic material contained in the constraining layer is any one of MgAl ₂ O ₄ , Al ₂ O ₃ and ZrO ₂ , the first constituting the base material layer It is possible to improve the wettability of the second ceramic material to the powder. Therefore, the glass in the base material layer easily penetrates into the constraining layer, and it becomes easy to densify the constraining layer and enhance the adhesion between the constraining layer and the base material layer.

In particular, when MgAl ₂ O ₄ is used as the second ceramic material, the reaction with the glass is suppressed as in the case of MgAl ₂ O ₄ as the filler in the base material layer described above, so a higher Q value. Can be obtained.

  In this invention, a part of the glass material contained in the base material layer diffuses or flows throughout the constraining layer, and all of the second powder is fixed to each other by a part of the glass material. Thus, the mechanical strength of the multilayer ceramic substrate can be increased.

  When the constraining layer is thinner than the base material layer, the glass material contained in the base material layer can be easily diffused or flown over the entire area of the constraining layer.

  According to the composite green sheet for producing a multilayer ceramic substrate according to the present invention, it is possible to efficiently produce a raw laminate produced for producing a multilayer ceramic substrate.

  FIG. 1 is a sectional view schematically showing a multilayer ceramic substrate 1 according to a first embodiment of the present invention.

  The multilayer ceramic substrate 1 includes a plurality of stacked base material layers 2, a constraining layer 3 positioned so that at least one main surface thereof is in contact with the base material layer 2, and a main surface direction of the base material layer 2. A laminated body 5 having a laminated structure including a conductor film 4 formed to extend is provided. In this embodiment, the base material layers 2 and the constraining layers 3 are alternately laminated. In addition, several via-hole conductors 6 are provided inside the multilayer body 5 so as to penetrate the specific base material layer 2 in the thickness direction while being electrically connected to a specific one of the conductor films 4. Yes.

The base material layer 2 is composed of an aggregate of first powders containing a glass material and a first ceramic material. In the first powder, the content of the glass material is 15 to 75% by weight, and the content of the first ceramic material is 25 to 85% by weight. The glass material is a composition comprising 33 to 68 mol% of _SiO 2, 3 to 52 mol% of CaO, 1 to 36 mol% of _Al 2 _{O 3} and 1 to 25 mole% _B 2 _{O 3} . Then, as the first ceramic material, MgAl ₂ O ₄ is used.

On the other hand, the constraining layer 3 is composed of an aggregate of second powders containing a second ceramic material that is not sintered at a temperature at which the glass material contained in the base material layer 2 can be melted. As the second ceramic material, any one of MgAl ₂ O ₄ , Al ₂ O ₃ and ZrO ₂ is preferably used. More preferably, MgAl ₂ O ₄ is used as the second ceramic material.

  The conductor film 4 and the via-hole conductor 6 are obtained by sintering a conductive paste, and for example, Ag is used as a conductive component contained in the conductive paste.

  At least a part of the first powder contained in the base material layer 2 is in a sintered state. On the other hand, the second powder contained in the constraining layer 3 is fixed to each other as part of the first powder containing the glass material diffuses or flows into the constraining layer 3. Here, the constraining layer 3 is considered that the second powder is substantially in an unsintered state, but may be partially sintered.

  Preferably, the constraining layer 3 is made thinner than the base material layer 2.

  Chip components 8 and 9 are mounted on the upper main surface of the multilayer ceramic substrate 1. Chip components 8 and 9 are electrically connected to conductor film 4 formed on the upper main surface of multilayer ceramic substrate 1. The conductor film 4 formed on the lower main surface of the multilayer ceramic substrate 1 electrically connects the multilayer ceramic substrate 1 to the motherboard when the multilayer ceramic substrate 1 is mounted on the motherboard (not shown). Used for mechanical fixation.

  The multilayer ceramic substrate 1 is manufactured as follows.

  First, the raw material of the laminate 5 shown in FIG. 1 is prepared. The raw laminate 5 includes a raw substrate layer 2, a raw constraining layer 3, a raw conductor film 4, and a raw via-hole conductor 6. It has.

  In order to obtain the raw laminate 5, typically, a green sheet to be the base layer 2 and a green sheet to be the constraining layer 3 are prepared, and they are laminated in a predetermined order. However, thick film printing may be repeated for the constraining layer 3 or for both the base material layer 2 and the constraining layer 3 to obtain a raw laminate 5.

The base material layer 2 in the raw state includes a first powder containing 15 to 75% by weight of a glass material and 25 to 85% by weight of a first ceramic material. Glass material, as described above, comprises 33 to 68 mol% of _SiO 2, 3-52 mol% of CaO, _Al 2 _{O 3} and 1 to 25 mole% _B 2 _{O 3} of 1 to 36 mol%, As described above, the first ceramic material is MgAl ₂ O ₄ . The base material layer 2 in the raw state further contains a binder, a solvent, a dispersant, and a plasticizer.

The constraining layer 3 in the raw state includes a second powder containing a second ceramic material that is not sintered at a temperature at which the glass material contained in the first powder can be melted. As the second ceramic material, preferably, as described above, any one of MgAl ₂ O ₄ , Al ₂ O ₃ and ZrO ₂ is used, and more preferably, MgAl ₂ O ₄ is used. The constraining layer 3 in the raw state further contains a binder, a solvent, a dispersant, and a plasticizer.

  The conductor film 4 and the via-hole conductor 6 in the raw state are made of a conductive paste. This conductive paste contains, for example, a conductive metal powder such as Ag powder, a binder, and a solvent.

  Next, a step of firing the raw laminate 5 having the above-described structure is performed. Conditions such as the temperature applied in the firing step are, for example, 700 to 1000 ° C. and 0.5 to 2 hours, and are selected so that the following state is obtained after the firing step.

  That is, as a result of the firing step, at least a part of the first powder included in the base material layer 2 is sintered. A part of the first powder containing the glass material contained in the base material layer 2 diffuses or flows into the constraining layer 3. Thereby, the second powder contained in the constraining layer 3 is fixed to each other. At this time, a part of the glass material contained in the base material layer 2 diffuses or flows over the entire area of the constraining layer 3, whereby all of the second powders are fixed to each other. Densification is preferred. As described above, when the constraining layer 3 is thinner than the base material layer 2, it is easy to diffuse or flow the glass material contained in the base material layer 2 throughout the constraining layer 3.

  In the firing step, the second powder itself contained in the constraining layer 3 is not substantially sintered at the firing temperature of the base material layer 2, so that the constraining layer 3 is not substantially contracted. Therefore, the constraining layer 3 exerts a shrinkage suppressing action on the base material layer 2 and suppresses shrinkage in the main surface direction of the base material layer 2. From this, undesired deformation hardly occurs in the obtained multilayer ceramic substrate 1, and the dimensional accuracy can be improved.

In the firing step, the glass material included in the base material layer 2 is a glass material having a specific composition as described above, and the first ceramic material also included in the base material layer 2 is MgAl ₂ O _4. Therefore, the reaction of the first ceramic material to the glass material is suppressed, the increase of the dielectric loss in the high frequency region is suppressed, and the Q value can be kept high.

Further, as described above, when any one of MgAl ₂ O ₄ , Al ₂ O _3, and ZrO ₂ is used as the second ceramic material included in the constraining layer 3, these constitute the base material layer 2. The wettability with the first powder aggregate is good. Therefore, in the firing step, the glass in the base material layer 2 easily penetrates into the constraining layer 3, the densification layer 3 is densified, and the adhesion between the constraining layer 3 and the base material layer 2 is easy.

When MgAl ₂ O ₄ is used as the second ceramic material included in the constraining layer 3, it is included in the base material layer 2 as in the case of MgAl ₂ O ₄ as the first ceramic material in the base material layer 2. Since the reaction with the glass material is suppressed, a higher Q value can be obtained.

  Next, chip components 8 and 9 are mounted on the upper main surface of the multilayer ceramic substrate 1.

  FIG. 2 is a cross-sectional view schematically showing a multilayer ceramic substrate 1a according to the second embodiment of the present invention. In FIG. 2, elements corresponding to those shown in FIG. 1 are denoted by the same reference numerals, and redundant description is omitted.

  The multilayer ceramic substrate 1a shown in FIG. 2 is characterized in that a cavity 11 is provided in the laminate 5. Inside the cavity 11, as indicated by an imaginary line, the chip component 12 is accommodated and mounted.

  In a multilayer ceramic substrate having a cavity, deformation such as distortion is likely to occur particularly at the bank portion (cavity side wall portion). However, in this example, since the constraining layer 3 is disposed on the bank portion, the deformation does not occur. There are few and highly accurate multilayer ceramic substrates 1a are obtained.

  In manufacturing the multilayer ceramic substrate 1 or 1a described above, it is also possible to laminate one green sheet to be each of the base material layer 2 and the constraining layer 3 in order to produce a laminate 5 in a raw state. However, as described below, it is preferably prepared in the state of a composite green sheet, and the raw laminate 5 is produced using this composite green sheet.

  3 to 6 show some examples of composite green sheets in cross-sectional views. 3 to 6, elements corresponding to those shown in FIG. 1 are denoted by the same reference numerals. Further, in FIGS. 3 to 6, illustration of the conductor film and the via-hole conductor is omitted.

  FIGS. 3 to 6 show a carrier film 15 made of, for example, polyethylene terephthalate. The carrier film 15 is used, for example, when a ceramic slurry to be the base material layer 2 is formed into a sheet shape, and facilitates handling of the green sheet after being formed. The carrier film 15 is peeled off and removed at the stage where the lamination process for obtaining the raw laminate 5 is completed.

  In the composite green sheet 16 shown in FIG. 3, a green sheet to be the raw substrate layer 2 is formed on the carrier film 15, and then dried as necessary, and then the substrate layer 2. It is obtained by forming a green sheet to be the constraining layer 3 in a raw state. In the case of this composite green sheet 16, although not shown, it is easy to form a conductor film on the constraining layer 3.

  The green sheet to be the base material layer 2 and the green sheet to be the constraining layer 3 may be formed by a series of steps, but the green sheet to be the base material layer 2 is formed. Thereafter, the carrier film 15 holding the green sheet to be the base material layer 2 is once wound in a roll shape, and then the green sheet to be the base material layer 2 is pulled out together with the carrier film 15 from the roll. You may make it shape | mold the green sheet which should become. This is also true for other composite green sheets 17 to 19 described with reference to FIGS.

  The composite green sheet 17 shown in FIG. 4 is formed on the carrier film 15 with a green sheet to be the constraining layer 3 in a raw state, then dried as necessary, and then in a raw state. It is obtained by molding a green sheet to be the base material layer 2. In the case of this composite green sheet 17, although not shown, it is easy to form a conductor film on the base material layer 2.

  Note that the composite green sheet 16 shown in FIG. 3 and the composite green sheet 17 shown in FIG. 4 have the same laminated structure when the carrier film 15 is removed.

  The composite green sheet 18 shown in FIG. 5 is a green sheet to be the constraining layer 3 in the raw state, a green sheet to be the base material layer 2 in the raw state, and a raw state on the carrier film 15. The green sheet to be the constraining layer 3 is obtained by molding in this order. In the case of this composite green sheet 18, although not shown, it is easy to form a conductor film on the constraining layer 3.

  The composite green sheet 19 shown in FIG. 6 has a green sheet to be the base layer 2 in a raw state, a green sheet to be the constraining layer 3 in a raw state, and a raw state on the carrier film 15. The green sheet to be the base material layer 2 is obtained by molding in this order. In the case of this composite green sheet 19, although not shown, it is easy to form a conductor film on the base material layer 2.

  The composite green sheets 16-19 mentioned above can produce the raw laminated body 5 by using any of these alone or using any of them in combination. For example, the raw laminate 5 can be produced by combining the composite green sheet 16 or 17 and the composite green sheet 18 or 19. Moreover, the raw laminated body 5 can be produced by laminating the composite green sheet 18 and the composite green sheet 19.

  While the present invention has been described with reference to the illustrated embodiment, various other modifications are possible within the scope of the present invention.

  For example, in the multilayer ceramic substrate 1 shown in FIG. 1 and the multilayer ceramic substrate 1a shown in FIG. 2, the base layer 2 and the constraining layer 3 are alternately formed. At least one main surface may be positioned so that not the constraining layer 3 but another base material layer 2 is in contact therewith.

  In the laminated body 5 shown in FIGS. 1 and 2, the constraining layer 3 is located on the outermost side, but the base material layer 2 is located on the outermost side for at least one main surface. May be located. In this latter case, a shrinkage suppression layer having a composition that is substantially the same as that of the constraining layer 3 but having a thickness that prevents the second powder contained therein from being fixed to each other is formed in the raw laminate. You may make it arrange | position on an at least one main surface, implement a baking process in the state which suppressed shrinkage | contraction by this, and may make it remove this shrinkage | contraction suppression layer after a baking process.

Moreover, a trace amount additive may be added to the glass material contained in a base material layer within the range which does not impair the objective of this invention. For example, by adding 0.01 to 5.0% by weight of MgCO ₃ , ZnO, LiCO ₃ , Pb ₃ O ₄ , Bi ₂ O ₃ , BaCO ₃ , SrCO _3, etc., the reaction with MgAl ₂ O ₄ is suppressed. Thus, a higher Q value can be obtained.

In addition to the MgAl ₂ O ₄ , Al ₂ O ₃ and ZrO ₂ described above, the second ceramic material contained in the constraining layer includes MgO, SiO ₂ , TiO ₂ , BaTiO ₃ , SrTiO ₃ , MgTiO ₃ , Pb (Zr, Ti) O ₃ , B ₄ C, SiC, WC, or the like can also be used.

  Next, experimental examples carried out to confirm the effects of the present invention will be described.

(Experimental example 1)
First, SiO ₂ , CaCO ₃ , Al ₂ O _3, and B ₂ O ₃ powders are prepared as starting materials for the glass material, and each composition ratio (unit is “wt%”) shown in Table 1 is obtained. It was formulated. And after mixing this prepared mixed powder in the temperature of 1400-1600 degreeC in a Pt-Rh crucible, it cools rapidly and grind | pulverizes further to obtain glass powder G1-G38 with an average particle diameter of 2.0 micrometers. It was.

  Next, in order to obtain a green sheet for the base material layer, a first ceramic material powder having an average particle diameter of 1.0 μm shown in the column of “first ceramic material” in the “base material layer” of Table 2 is prepared. In addition, a glass powder having the composition shown in Table 1 corresponding to the glass symbol shown in the column “Glass material” is prepared, and the weight ratio of the first ceramic material powder and the glass powder is 1: 1. It mixed so that it might become. Then, from 100 parts by weight of the first ceramic material powder and the glass powder, from 2.0 parts by weight of DOP (dioctyl phthalate) as plasticizer, 60 parts by weight of toluene and 40 parts by weight of echinene An organic solvent, and 10.0 parts by weight of polyvinyl butyral as a binder are added and mixed to obtain a slurry. The slurry is formed into a sheet by a doctor blade method and used for a base material layer having a thickness of 50 μm. A green sheet was obtained.

  On the other hand, in order to obtain a green sheet for a constraining layer, a second ceramic material powder having an average particle size of 1.0 μm shown in the column “Second ceramic material” in “Constraining layer” in Table 2 was prepared. An organic solvent composed of 2.0 parts by weight of DOP (dioctyl phthalate), 85 parts by weight of toluene and 50 parts by weight of echinene, and 10 parts by weight with respect to 100 parts by weight of the second ceramic material powder. Polyvinyl butyral as a binder of 0.0 part by weight was added and mixed to obtain a slurry. The slurry was formed into a sheet by a doctor blade method to obtain a green sheet for a constraining layer having a thickness of 5 μm.

  In addition, in order to form a conductor film, a conductive metal powder containing 48% by weight of Ag powder having an average particle diameter of 2 μm as a conductive metal powder, 3% by weight of ethyl cellulose as a binder, and 49% by weight of terpenes as a solvent. A paste was prepared.

  Next, in order to fabricate the laminates 21 to 25 as shown in FIGS. 7 to 11, the above-described green sheet for base material layer is used in the base material layer 26, and the above-described constraining layer for the constraining layer 27. While using a green sheet, a lamination process is performed, and in the case of the laminates 23 to 25 shown in FIGS. 9 to 11, in order to form the conductor film 28, the above-described conductive paste printing process is performed, Laminated bodies 21 to 25 in a raw state were obtained, respectively.

Next, a pressure of 100 kg / cm ² was applied to each of the raw laminates 21 to 25 with a press machine, and then fired at a temperature of 900 ° C. for 1 hour. As a result, as shown in Table 2, with the exception of Samples 10, 18, 29 and 34, laminates 21 to 25 as sintered bodies can be obtained in a state where there is substantially no contraction in the main surface direction. Was confirmed.

On the other hand, in order to evaluate the dielectric characteristics, the same manufacturing method as in the case of the above-described laminates 21 to 25 is applied, and as shown in FIG. A laminate 31 as a bonded body was produced. And the electrode was formed in the predetermined position of the laminated body 31, the relative dielectric constant (epsilon) _r and Q value in the measurement frequency of 3 GHz were measured with the perturbation method, and Q value was converted into Q value in 1 GHz.

  These results are shown in Table 2.

  In Table 1, the glass symbol with * and the sample number with * in Table 2 are out of the scope of the present invention.

According to the sample 4～7,14～17,23～25,30～32,35～37 and 39-41 are within the scope of the invention, SiO ₂ is 33 to 68 mol%, CaO is 3-52 mol Glass materials G4 to G7, G14 to G17, G23 to G25, G30 to G32, and G35 to G37 that satisfy the following conditions:%, Al ₂ O ₃ is 1 to 36 mol% and B ₂ O ₃ is 1 to 25 mol% Since any one of the above is used in the base material layer, a Q value of 1500 GHz or more is exhibited, and excellent high-frequency dielectric characteristics are obtained.

Here, as can be seen by comparing Samples 4-7, 14-17, 23-25, 30-32, and 35-37 with Samples 39-41, the second ceramic material contained in the constrained layer is MgAl _2. Not only in the case of O ₄ , but also in any case of Al ₂ O ₃ , ZrO ₂ and MgO, a Q value of 1500 GHz or more is shown.

On the other hand, in samples 1 to 3, 8 to 13, 18 to 22, 26 to 29, 33, 34 and 38 which are out of the scope of the present invention, SiO ₂ , CaO, Al ₂ O ₃ and B ₂ O ₃ Since any one of the glass materials G1 to G3, G8 to G13, G18 to G22, G26 to G29, G33, G34 and G38 that do not satisfy the conditions of the composition range described above is used in the base material layer, Q value is lower than 1500 GHz or does not sinter.

In Samples 42 to 47, as the glass material contained in the base material layer, any one of the glass materials G6, G14, and G24 that are within the scope of the present invention is used as the first ceramic material. The Q value is lower than 1500 GHz because Al ₂ O ₃ is used instead of MgAl ₂ O ₄ .

(Experimental example 2)
In Experimental Example 2, the trend of the Q value was investigated by changing the ratio of the glass material and the first ceramic material contained in the first powder aggregate constituting the base material layer.

In Table 3, “Glass symbol” corresponds to “Glass symbol” in Table 1, and “Glass amount” represents the weight ratio of the glass material to the total weight of the glass material and the first ceramic material in the base material layer. “MgAl ₂ O ₄ content” indicates the weight ratio of MgAl ₂ O ₄ as the first ceramic material to the total weight of the glass material and the first ceramic material.

Each sample was produced by the same method as in the case of Experimental Example 1 described above, and the relative dielectric constant ε _r and the Q value were evaluated. Table 3 shows the results.

  In Table 3, the sample number marked with * is out of the scope of the present invention.

Referring to Table 3, samples 49 to 51, 54 to 56 and 59 to 61 satisfying the condition that the “glass amount” is 15 to 75% by weight and the “MgAl ₂ O ₄ amount” is 25 to 85% by weight. According to this, the Q value is as high as 1500 GHz or more, and excellent high frequency dielectric characteristics are exhibited.

On the other hand, the samples 48, 53 and 58 in which the “glass amount” is less than 15% by weight and the “MgAl ₂ O ₄ amount” exceeds 85% by weight are not sintered.

In the samples 52, 57 and 62 in which the “glass amount” exceeds 75% by weight and the “MgAl ₂ O ₄ amount” is less than 25% by weight, the Q value is lower than 1500 GHz.

1 is a cross-sectional view schematically showing a multilayer ceramic substrate 1 according to a first embodiment of the present invention. It is sectional drawing which shows schematically the multilayer ceramic substrate 1a by 2nd Embodiment of this invention. It is sectional drawing which shows the 1st example of the composite green sheet used in order to produce a raw laminated body. It is sectional drawing which shows the 2nd example of the composite green sheet used in order to produce a raw laminated body. It is sectional drawing which shows the 3rd example of the composite green sheet used in order to produce a raw laminated body. It is sectional drawing which shows the 4th example of the composite green sheet used in order to produce a raw laminated body. It is sectional drawing which shows the 1st example of the laminated body produced in order to confirm sinterability in Experimental example 1. FIG. It is sectional drawing which shows the 2nd example of the laminated body produced in order to confirm sinterability in Experimental example 1. FIG. It is sectional drawing which shows the 3rd example of the laminated body produced in order to confirm sinterability in Experimental example 1. FIG. FIG. 6 is a cross-sectional view showing a fourth example of a laminate manufactured for confirming sinterability in Experimental Example 1. FIG. 10 is a cross-sectional view showing a fifth example of a laminate manufactured for confirming sinterability in Experimental Example 1. 6 is a cross-sectional view showing a laminate produced for evaluating dielectric characteristics in Experimental Example 1. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,1a Multilayer ceramic substrate 2,26 Base material layer 3,27 Constrained layer 4,28 Conductor film 5,21-25,31 Laminated body 16-19 Composite green sheet

Claims (9)

A plurality of laminated base layers composed of an aggregate of first powders including a glass material and a first ceramic material;
An aggregate of second powders including a second ceramic material that is positioned such that at least one main surface thereof is in contact with the base material layer and that does not substantially sinter at a temperature at which the base material layer is sintered. Comprising a constrained layer,
At least a part of the first powder is in a sintered state,
The second powder is fixed to each other by diffusing or flowing a part of the first powder containing the glass material into the constraining layer,
The first powder includes 15 to 75% by weight of the glass material, and 25 to 85% by weight of the first ceramic material;
It said glass material comprises 33 to 68 mol% of _SiO 2, from 3 to 52 mol% of CaO, _Al 2 _{O 3} and 1 to 25 mole% _B 2 _{O 3} of 1 to 36 mol%,
The first ceramic material is MgAl ₂ O ₄ ;
Multilayer ceramic substrate. The multilayer ceramic substrate according to claim 1, wherein the second ceramic material is one of MgAl ₂ O ₄ , Al ₂ O _3, and ZrO ₂ . The multilayer ceramic substrate according to claim 1, wherein the second ceramic material is MgAl ₂ O ₄ .   The multilayer ceramic substrate according to claim 1, further comprising a conductor film formed along at least one main surface of the base material layer and the constraining layer.   A part of the glass material contained in the base material layer diffuses or flows throughout the constraining layer, and all of the second powder is fixed to each other by a part of the glass material. A multilayer ceramic substrate according to any one of claims 1 to 4.   The multilayer ceramic substrate according to claim 1, wherein the constraining layer is thinner than the base material layer. A substrate layer in a green state comprising a first powder comprising a glass material and a first ceramic material;
A second powder comprising a second ceramic material that is positioned such that at least one major surface thereof is in contact with the base material layer and that does not substantially sinter at a temperature at which the base material layer is sintered; With a constrained layer in a raw state,
The first powder includes 15 to 75% by weight of the glass material, and 25 to 85% by weight of the first ceramic material;
It said glass material comprises 33 to 68 mol% of _SiO 2, from 3 to 52 mol% of CaO, _Al 2 _{O 3} and 1 to 25 mole% _B 2 _{O 3} of 1 to 36 mol%,
The first ceramic material is MgAl ₂ O ₄ ;
Composite green sheet for making multilayer ceramic substrates.   The composite green sheet for producing a multilayer ceramic substrate according to claim 7, wherein the constraining layer is disposed so as to be in contact with both main surfaces of the base material layer.   The composite green sheet for producing a multilayer ceramic substrate according to claim 7, wherein the base material layer is disposed so as to be in contact with both main surfaces of the constraining layer.

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