JPH07201222A - Conductive paste, ceramic lamination body, and manufacture of ceramic lamination body - Google Patents

Abstract

PURPOSE:To provide a ceramic lamination body in which delamination may not occur by manufacturing the ceramic lamination body by forming conductive paste including ceramic grain of a grain size larger than a film thickness of an inner conductor layer. CONSTITUTION:A process of forming an unbaked inner conductor layer comprising conductive paste including metal fine powder on a ceramic layer, and a process of laminating another ceramic layer on the inner conductor layer are repeated more than one times to form an unbaked ceramic lamination body. This unbaked ceramic lamination body is baked to provide a ceramic lamination body. In this manufacturing method, the conductive paste is formed to include ceramic grains of a larger grain size than a film tickness of the inner conductor layer after baking.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a conductive paste for forming an internal conductor layer of a ceramic laminate, a ceramic laminate formed by using the conductive paste, and a method for producing the ceramic laminate. .

[0002]

2. Description of the Related Art As a ceramic laminated body, there are known a laminated ceramic capacitor, a laminated inductor, a multilayer substrate, an electronic component in which these are combined, and the like.

Of these ceramic laminated bodies, for example, a laminated ceramic capacitor has a structure in which dielectric layers and internal conductor layers are alternately laminated, and each dielectric layer is sandwiched by internal conductor layers. Has become. Here, the dielectric layer is formed by firing an unfired porcelain sheet (ceramic green sheet) at a high temperature and sintering it, and the internal conductor layer is obtained by firing a conductive paste at a high temperature to form a conductive metal thin film. It consists of

The conductive paste is generally composed of fine metal powder dispersed with an organic binder and an organic solvent. Here, as the fine metal powder, precious metal (Pd, A
g) or fine powder of base metal (Ni, Cu, etc.), acrylic resin, phenol resin, alkyd resin, rosin ester, various celluloses, etc. are used as the organic binder, and the organic solvent is Alcohol-based, hydrocarbon-based, ether-based, ester-based, etc. are used.

This conductive paste is printed on a ceramic green sheet in a predetermined pattern by a screen printing method. The ceramic green sheet on which the conductive paste is printed in a predetermined pattern is dried with an organic solvent, and then a plurality of sheets are stacked and pressure-bonded and cut into dice, and then 1
It is baked at a high temperature of about 200 to 1400 ° C. By this firing, the organic binder in the conductive paste is burned and removed, and the fine metal powder is sintered to form a film-shaped internal conductor layer.

[0006]

By the way, when a ceramic laminated body is formed by using a conventional conductive paste, the composition of the ceramic layer and the internal conductor layer is significantly different. There is a problem that the bonding force between the layers is relatively weak and delamination may occur due to the difference in expansion and contraction between the ceramic layer and the internal conductor layer during firing.

The present invention provides a conductive paste that does not cause delamination in a ceramic laminate, a ceramic laminate that does not cause delamination, and a method for making such a ceramic laminate. The purpose is to provide.

[0008]

In order to solve the above-mentioned problems, a conductive paste according to a first aspect of the present invention contains at least fine metal powder, an organic binder and an organic solvent, and an internal conductor between ceramic layers. In a conductive paste for forming the inner conductor layer of a ceramic laminate having at least one structure having layers sandwiched therein, ceramic particles having a particle size equal to or larger than the film thickness of the inner conductor layer were contained.

In order to solve the above-mentioned problems, the ceramic laminated body according to a fifth aspect of the present invention is a ceramic laminated body having at least one structure in which an internal conductor layer is sandwiched between ceramic layers. Ceramic layers adjacent to each other through the layers were connected by ceramic particles penetrating the inner conductor layer.

In order to solve the above-mentioned problems, a method for manufacturing a ceramic laminate according to a ninth aspect of the present invention forms an unfired internal conductor layer made of a conductive paste containing fine metal powder on the ceramic layer. The step of stacking another ceramic layer on the internal conductor layer is repeated one or more times to form an unfired ceramic laminate, and the unfired ceramic laminate is fired to form a ceramic. In the method for manufacturing a ceramic laminated body for obtaining a laminated body, the conductive paste contains ceramic particles having a particle size larger than the film thickness of the internal conductor layer after firing.

In order to solve the above-mentioned problems, the method for manufacturing a ceramic laminate according to a thirteenth aspect forms an unfired internal conductor layer made of a conductive paste containing fine metal powder on the ceramic layer. The step, the step of sprinkling ceramic powder on the unsintered internal conductor layer, and the step of laminating another ceramic layer on the internal conductor layer are repeated to form an unsintered ceramic laminate, A method for manufacturing a ceramic laminate, in which a ceramic laminate obtained by firing an unfired ceramic laminate is obtained, wherein a particle diameter of the ceramic powder is larger than a film thickness of the internal conductor layer after firing.

Here, as the material of the ceramic particles, as described in claims 2, 6, 10 and 14, a composition having substantially the same composition as the ceramic layer of the ceramic laminate is preferable.

Further, the particle size of the ceramic particles is preferably 1.0 to 3.0 times the film thickness of the internal conductor layer of the ceramic laminate as described in claims 3, 7, 11 and 15. . If the particle size of the ceramic particles is less than 1.0 times the film thickness of the internal conductor layer, the adjacent ceramic layers cannot be connected, and if the particle size of the ceramic particles exceeds 3 times the film thickness of the internal conductor layer, the ceramic is This is because the green sheet forming the layer is deformed.

Further, the content of the ceramic particles is 1 to 30 with respect to the weight of the fine metal powder contained in the conductive paste or the internal conductor layer, as described in claims 4, 8, 12 and 16. Parts by weight are preferred. This is because if the content of the ceramic particles is less than 1 part by weight, there is no delamination-preventing effect, and if the content of the ceramic particles exceeds 30 parts by weight, the continuity of the internal conductor layer is deteriorated and the capacity design becomes difficult. .

As the metal fine powder, for example, Pd,
Fine powders of precious metals such as Pt, Ag and Au and fine powders of base metals such as Ni and Cu can be used. Examples of the organic binder include acrylic resin, phenol resin, alkyd resin, rosin ester, various celluloses, etc., but are not limited to these, and organic compounds other than these can also be used. . As the organic solvent, alcohol-based, hydrocarbon-based, ether-based, ester-based solvents and the like can be used.

In addition to the above-mentioned components, it is common to add additives to the conductive paste. As the additive, oxides such as BaO and TiO ₂ , ceramic powder of the same quality as the ceramic layer, organic bentonite, and the like can be used.

[0017]

Since the conductive paste according to claim 1 contains ceramic particles having a particle size equal to or larger than the film thickness of the internal conductor layer after firing, a ceramic green sheet having the internal conductor layer printed thereon is laminated. When pressure-bonded, the ceramic particles are exposed from the front and back surfaces of the inner conductor layer and penetrate into each ceramic layer sandwiching the inner conductor layer, and when fired at high temperature, the ceramic particles and the ceramic layer are respectively burned. Connect and combine.

Further, since the conductive paste according to the second aspect contains ceramic particles made of a composition having substantially the same composition as the ceramic layer, when a ceramic laminate is manufactured using this, the ceramic paste is The electrical properties of the stack are less affected by the ceramic particles.

Since the conductive paste according to claim 3 contains ceramic particles having a particle diameter of 1.3 to 3.0 times the film thickness of the internal conductor layer, the ceramic paste is used. When a laminated body is manufactured, adjacent ceramic layers are firmly connected by the ceramic particles sandwiched between them.

Further, in the conductive paste according to the present invention, the content of the ceramic particles is 1 to 30 parts by weight with respect to the weight of the fine metal powder. In this case, the adjacent ceramic layers are firmly connected by the ceramic particles sandwiched between them.

In the ceramic laminate according to the present invention, the ceramic layers adjacent to each other with the internal conductor layer interposed therebetween are
Since they are connected by the ceramic particles penetrating the inner conductor layer, it is difficult for adjacent ceramic layers to separate via the inner conductor layer even if stress locally acts.

Further, in the ceramic laminate according to the sixth aspect, the composition having substantially the same composition as that of the ceramic layer is used as the ceramic particles for connecting the ceramic layers, so that the electrical characteristics of the ceramic laminate are Not easily affected by ceramic particles.

In the ceramic laminate according to the present invention, the particle size of the ceramic particles connecting adjacent ceramic layers is set to 1.3 to the thickness of the internal conductor layer.
Since it is set to 3.0 times, the adjacent ceramic layers are firmly connected by the ceramic particles sandwiched therebetween.

In the ceramic laminate according to the present invention, the content of the ceramic particles connecting the adjacent ceramic layers is 1 with respect to the weight of the fine metal powder contained in the inner conductor layer. Since the amount is up to 30 parts by weight, the adjacent ceramic layers are firmly connected.

Further, in the method for manufacturing a ceramic laminate according to the ninth aspect, an internal conductor is prepared by using a conductive paste containing ceramic particles having a particle size equal to or larger than the film thickness of the internal conductor layer after firing. Since the layers are formed, when the ceramic green sheets printed with the inner conductor layers are laminated and pressure-bonded, the ceramic particles are exposed from the front and back surfaces of the inner conductor layers, and the ceramic layers sandwiching the inner conductor layers are exposed. When it digs into and is fired at a high temperature, the ceramic particles and the ceramic layer are respectively sintered and bonded.

In the method for manufacturing a ceramic laminate according to the tenth aspect of the present invention, a conductive paste containing ceramic particles made of a composition having substantially the same composition as the ceramic layer is used. When the ceramic laminate is manufactured using the ceramic laminate, the electrical characteristics of the ceramic laminate are not easily affected by the ceramic particles.

The method for manufacturing a ceramic laminate according to claim 11 has a thickness of the internal conductor layer of 1.3 to 3.
Since the conductive paste containing the ceramic particles of 0 times the particle size is used, when a ceramic laminate is manufactured using this, the ceramic particles sandwiched between the adjacent ceramic layers firmly adhere to each other. Be connected.

Further, in the method for producing a ceramic laminate according to the twelfth aspect of the invention, since the conductive paste is used in which the content of the ceramic particles is 1 to 30 parts by weight with respect to the weight of the fine metal powder. When a ceramic laminate is manufactured using this, adjacent ceramic layers are firmly connected by the ceramic particles sandwiched between them.

In the method for manufacturing a ceramic laminate according to a thirteenth aspect, the internal conductor after firing is formed on the unfired internal conductor layer before the other ceramic layers are laminated on the internal conductor layer. Since the ceramic powder having a particle size larger than the layer thickness is sprinkled, when the ceramic green sheets printed with the internal conductor layers are laminated and pressure-bonded, the ceramic particles penetrate the internal conductor layers and sandwich the internal conductor layers. When it digs into each ceramic layer and is fired at a high temperature, the ceramic particles and the ceramic layer are respectively sintered and bonded.

Further, in the method for producing a ceramic laminate according to the fourteenth aspect, since the ceramic particles composed of the composition having substantially the same composition as the ceramic layer are used, the ceramic laminate is produced using the same. In this case, the electrical characteristics of the ceramic laminate are not easily affected by the ceramic particles.

The method for manufacturing a ceramic laminate according to the fifteenth aspect is characterized in that the internal conductor layer has a thickness of 1.3 to 3.
Since the ceramic particles of 0 times the particle size are used, when a ceramic laminated body is manufactured using this, adjacent ceramic layers are firmly connected by the ceramic particles sandwiched therebetween.

Further, in the method for manufacturing a ceramic laminate according to claim 16, the amount of the ceramic particles used is 1 to 3 with respect to the weight of the fine metal powder contained in the conductive paste.
Since it is 0 part by weight, when a ceramic laminate is manufactured using this, adjacent ceramic layers are firmly connected by the ceramic particles sandwiched therebetween.

[0033]

【Example】

Example 1 First, ceramic particles having a particle size of 3 μm were prepared using a barium titanate-based ceramic material formed for a dielectric layer. Then, the ceramic particles (10 parts by weight), Pd powder (50 parts by weight), ethyl cellulose (4 parts by weight)
Parts by weight) and butyl carbitol (70 parts by weight) were placed in a three-roll mill and sufficiently kneaded to prepare a conductive paste for the internal conductor layer.

Next, the pattern of the conductive paste was printed on the barium titanate-based ceramic green sheet formed for the dielectric layer by a screen printing method. After the conductive paste is dried, 50 layers of this ceramic green sheet are laminated, pressed and pressed, cut into dice, baked in a baking furnace, and external electrodes are baked to form a laminated ceramic capacitor. did.

Next, the capacitance (μF) of this laminated ceramic capacitor was examined. The results are as shown in Sample No. 1 in Table 1. Further, this multilayer ceramic capacitor was cut along a plane perpendicular to the surface of the internal conductor layer, mirror-polished, and observed with an optical microscope to examine the number of delaminations in 100 multilayer ceramic capacitors. The results are as shown in Sample No. 1 in Table 1.

Comparative Example 1 A conductive paste was prepared under the same conditions as in Example 1 except that ceramic particles were not added, and a multilayer ceramic capacitor was prepared under the same conditions as in Example 1 and its electrostatic The capacity (μF) and the number of delaminations in 100 laminated ceramic capacitors were examined. The results are shown in Table 1, Sample No. 2.

[0037]

[Table 1]

Example 2 A conductive paste was prepared under the same conditions as in Example 1 except that the particle size of the ceramic particles was changed in the range of 1.0 μm to 5.0 μm. A laminated ceramic capacitor was prepared under the conditions. The film thickness of the internal conductor layer of this multilayer ceramic capacitor was 2.0 μm. And the electrostatic capacitance (μF) of this multilayer ceramic capacitor
Also, when the number of delaminations in 100 laminated ceramic capacitors was examined, it was as shown in Table 2.

[0039]

[Table 2]

Although the above embodiment has been described with respect to the monolithic ceramic capacitor, the present invention is not limited to the monolithic ceramic capacitor and can be applied to a monolithic inductor, a multi-layer substrate, or an electronic component in which these are combined.

[0041]

According to the invention described in claim 1, when the ceramic green sheets printed with the internal conductor layer pattern are laminated and pressure-bonded, the ceramic particles are exposed from the front and back surfaces of the internal conductor layer pattern. When the ceramic layers that sandwich the internal conductor layer pattern are bitten and fired at a high temperature, the ceramic particles and the ceramic layers are respectively sintered and bonded, and the adjacent ceramic layers are firmly connected by the ceramic particles. Therefore, there is an effect that it is possible to obtain a ceramic laminated body that hardly causes delamination.

According to the second aspect of the invention, since the electrical characteristics of the ceramic laminated body are not easily influenced by the ceramic particles, there is an effect that a ceramic laminated body having good electric characteristics can be obtained. .

Further, according to the invention described in claim 3, since the adjacent ceramic layers are firmly connected by the ceramic particles, there is an effect that it is possible to obtain a ceramic laminated body in which delamination is further difficult to occur. .

Further, according to the invention of claim 4, since the adjacent ceramic layers are strongly connected by the ceramic particles, it is possible to obtain a ceramic laminate in which delamination is further difficult to occur. is there.

Further, according to the invention described in claim 5, the ceramic layers adjacent to each other via the internal conductor layer are firmly connected by the ceramic particles penetrating the internal conductor layer, and the stress acts locally. However, since the adjacent ceramic layers are difficult to separate via the internal conductor layer, there is an effect that a ceramic laminated body in which delamination hardly occurs can be obtained.

Further, according to the invention described in claim 6, since the electrical characteristics of the ceramic laminated body are not easily influenced by the ceramic particles, there is an effect that a ceramic laminated body having good electric characteristics can be obtained. .

Further, according to the invention described in claim 7, since the adjacent ceramic layers are strongly connected by the ceramic particles, there is an effect that a ceramic laminated body in which delamination is further difficult to occur can be obtained.

Further, according to the invention described in claim 8, since the adjacent ceramic layers are strongly connected by the ceramic particles, it is possible to obtain a ceramic laminated body in which delamination is further difficult to occur. is there.

Further, in the invention described in claim 9, when the ceramic green sheets printed with the internal conductor layers are laminated and pressure-bonded, the ceramic particles are exposed from the front and back surfaces of the internal conductor layers, and the internal conductor layers are exposed. When it digs into each ceramic layer sandwiching, and when fired at high temperature, the ceramic particles and the ceramic layer are respectively sintered and bonded,
There is an effect that it is possible to obtain a ceramic laminated body in which adjacent ceramic layers are strongly connected by ceramic particles and in which delamination does not easily occur.

In the method for manufacturing a ceramic laminate according to the tenth aspect of the present invention, the conductive paste containing the ceramic particles made of the composition having substantially the same composition as the ceramic layer is used. When the ceramic laminated body is manufactured using the ceramic laminated body, the electrical characteristics of the ceramic laminated body are less likely to be affected by the ceramic particles.

The method of manufacturing a ceramic laminate according to claim 11 has a thickness of the internal conductor layer of 1.3 to 3.
Since the conductive paste containing the ceramic particles of 0 times the particle size is used, when a ceramic laminate is manufactured using this, the ceramic particles sandwiched between the adjacent ceramic layers firmly adhere to each other. It has the effect of being linked.

Further, in the method for producing a ceramic laminate according to the twelfth aspect of the invention, since the conductive paste is used in which the content of the ceramic particles is 1 to 30 parts by weight based on the weight of the fine metal powder. , When a ceramic laminate is manufactured using this, since the adjacent ceramic layers are firmly connected by the ceramic particles sandwiched between them,
There is an effect that it is possible to obtain a laminated body that does not cause delamination.

Further, in the method for manufacturing a ceramic laminate according to the thirteenth aspect, when the ceramic green sheets printed with the internal conductor layers are laminated and pressure-bonded, the ceramic particles penetrate the internal conductor layers, and When it digs into each ceramic layer that sandwiches the layers, and when fired at high temperature, the ceramic particles and the ceramic layer sinter
Since they are bonded, there is an effect that it is possible to obtain a ceramic laminated body that hardly causes delamination.

Further, in the method for manufacturing a ceramic laminate according to the thirteenth aspect, since the ceramic particles are added after printing the conductive paste, there is an effect that the printability of the conductive paste is not sacrificed. .

Further, in the method for manufacturing a ceramic laminate according to the present invention, since the ceramic particles made of a composition having substantially the same composition as the ceramic layer are used, the electrical characteristics of the ceramic laminate are ceramic particles. It is possible to obtain a ceramic laminate that is not easily affected by.

The method for manufacturing a ceramic laminate according to the fifteenth aspect of the present invention is the method for producing a ceramic laminate having a thickness of 1.3 to 3.
Since the ceramic particles of 0 times the particle size are used, the adjacent ceramic layers are firmly connected by the ceramic particles sandwiched between them.

In the method for producing a ceramic laminate according to the sixteenth aspect, the amount of the ceramic particles used is 1 to 3 with respect to the weight of the fine metal powder contained in the conductive paste.
Since the amount is 0 parts by weight, the adjacent ceramic layers are firmly connected by the ceramic particles sandwiched therebetween.

Claims (16)

[Claims] 1. To form the internal conductor layer of a ceramic laminate having at least one structure in which at least one fine metal powder, an organic binder and an organic solvent are contained and the internal conductor layer is sandwiched between the ceramic layers. 2. The conductive paste according to item 1, which contains ceramic particles having a particle diameter equal to or larger than the film thickness of the internal conductor layer. 2. The conductive paste according to claim 1, wherein the ceramic particles are composed of a composition having substantially the same composition as the ceramic layer of the ceramic laminate. 3. The conductive paste according to claim 1, wherein the particle size of the ceramic particles is 1.0 to 3.0 times the film thickness of the internal conductor layer after firing. 4. The conductive paste according to claim 1, wherein the content of the ceramic particles is 1 to 30 parts by weight of the weight of the fine metal powder. 5. A ceramic laminate having at least one structure in which an internal conductor layer is sandwiched between ceramic layers, wherein ceramic particles adjacent to each other through the internal conductor layer penetrate through the internal conductor layer. A ceramic laminate characterized by being connected by. 6. The ceramic laminate according to claim 5, wherein the ceramic particles are composed of a composition having substantially the same composition as the ceramic layer of the ceramic laminate. 7. The ceramic laminate according to claim 5, wherein the particle size of the ceramic particles is 1.0 to 3.0 times the film thickness of the internal conductor layer. 8. The ceramic laminate according to claim 5, wherein the content of the ceramic particles is 1 to 30 parts by weight of the weight of the fine metal powder contained in the internal conductor layer. 9. A step of forming an unfired inner conductor layer made of a conductive paste containing fine metal powder on the ceramic layer, and a step of laminating another ceramic layer on the inner conductor layer. In the method for producing a ceramic laminate, which comprises repeatedly firing one or more times to form an unfired ceramic laminate and firing the unfired ceramic laminate to obtain a fired ceramic laminate, a film of an internal conductor layer after firing. A method for producing a ceramic laminate, wherein the conductive paste contains ceramic particles having a particle diameter larger than the thickness. 10. The method for producing a ceramic laminate according to claim 9, wherein the ceramic particles are made of a composition having substantially the same composition as the ceramic layer of the ceramic laminate. 11. The production of a ceramic laminate according to claim 9, wherein the ceramic particles have a particle size of 1.0 to 3.0 times the film thickness of the internal conductor layer after firing. Method. 12. The content of the ceramic particles is 1 to the weight of the fine metal powder contained in the conductive paste.
It is 30 weight part, The manufacturing method of the ceramic laminated body of Claims 9-11 characterized by the above-mentioned. 13. A step of forming an unsintered inner conductor layer made of a conductive paste containing fine metal powder on the ceramic layer, and a step of sprinkling the unsintered inner conductor layer with the ceramic powder. A step of stacking another ceramic layer on the internal conductor layer is repeated to form an unfired ceramic laminate, and the unfired ceramic laminate is fired to obtain a fired ceramic laminate. A method of manufacturing a ceramic laminate, wherein the particle size of the ceramic powder is larger than the film thickness of the internal conductor layer after firing. 14. The method for producing a ceramic laminate according to claim 13, wherein the ceramic particles are made of a composition having substantially the same composition as the ceramic layer of the ceramic laminate. 15. The production of a ceramic laminate according to claim 13 or 14, characterized in that the particle size of the ceramic particles is 1.0 to 3.0 times the film thickness of the internal conductor layer after firing. Method. 16. The amount of the ceramic particles used is 1 to the weight of the fine metal powder contained in the conductive paste.
It is 30 weight part, The manufacturing method of the ceramic laminated body of Claims 13-15 characterized by the above-mentioned.