JPH06103811A - Conductive paste composition - Google Patents

Abstract

PURPOSE:To enable a via conductor having a precise construction making close contact with a via hole to be formed without producing any discontinuity at a part of the via conductor and a gap in the via hole by using a specific composition for making a conductor for a via. CONSTITUTION:A via conductor is formed of inorganic component consisting of conductive material power of 30.0-70.0 weight % and crystallized glass ceramic powder of 30.0-70.0 weight % having glass transfer temperature higher than that of insulating material and organic vehicle component consisting of at least organic binder and solvent. Thus, since the insulating material for forming the via hole is sintered so as to form a via hole 2, and thereafter the glass component in a via conductor 1 material in the via hole is softened so that the via conductor is sintered, the via conductor 1 having a precise construction making firm and close contact with the via hole 2 is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a conductor paste composition used for manufacturing a ceramic multilayer wiring board on which LSI, IC and chip parts are mounted.

[0002]

2. Description of the Related Art As a method of manufacturing a ceramic multilayer substrate,
The green sheet laminating method and the thick film printing multi-layer method are known and widely used. The green sheet stacking method enables high stacking and fine wiring patterns, but on the other hand, it has drawbacks such as poor manufacturing yield and poor ability to respond to changes in wiring patterns, while it is thick film. The printing multi-layer method is simple in process, has good adaptability, and has a good manufacturing yield, but on the other hand, due to a step on the surface of the substrate due to the wiring pattern, it is not possible to highly stack and it is not possible to cope with a fine wiring pattern. As a method that takes advantage of these two manufacturing methods, a method (transfer method) is proposed in which a transfer sheet having a structure in which a wiring pattern is embedded in an insulating layer is transferred and laminated on a ceramic substrate.

On the other hand, an important point in the technique for manufacturing a ceramic multilayer substrate is a technique for connecting wiring layers. Generally, in order to connect wiring layers, a hole called a via hole is formed at a predetermined position on the wiring. The method of filling the conductor material is used.

[0004]

In the green sheet laminating method and transfer method, since the insulating layer and the conductor layer are laminated and integrated and then fired simultaneously, the conductor material inside the via hole and the insulating material forming the via hole are formed. If the timing of sintering is not precisely adjusted, the wiring and via conductors will be disconnected, and voids will be generated inside the via holes, resulting in a marked deterioration in connection reliability.

[0005]

In order to solve the above-mentioned problems, the present invention provides a conductor paste composition for vias containing 30.0 to 70.0% by weight of conductor material powder and an insulating material having a glass transition temperature. What uses a conductor paste composition comprising an inorganic component composed of 30.0 to 70.0% by weight of crystallized glass ceramic powder having a temperature higher than the glass transition temperature and an organic vehicle component composed of at least an organic binder and a solvent Is.

[0006]

According to the present invention, as described above, in the conductor for vias, 30.0 to 70.0% by weight of the conductor material powder and the crystallized glass ceramic powder 30. whose glass transition temperature is higher than the glass transition temperature of the insulating material. Since the conductor paste composition comprising the inorganic component of 0 to 70.0% by weight and the organic vehicle component of at least the organic binder and the solvent is used, the insulating material forming the via hole is sintered and the via hole is After the formation, the glass component in the via conductor material inside the via hole softens and the via conductor sinters, so there is no disconnection at the via conductor portion or voids inside the via hole, and it firmly adheres to the via hole. A via conductor having a precise structure can be formed.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. 1 (a), (b), (c),
(D) is a diagram showing a temperature profile of each step in the method for manufacturing a ceramic multilayer wiring board according to an embodiment of the present invention. 2 (a) and 2 (b) are schematic views showing a cross section of a via in a ceramic multilayer wiring board according to an embodiment of the present invention.

Example 1 50.0% by weight of a silver powder (made by Fukuda Metal Foil Powder Co., Ltd.) having an average particle size of about 3 μm and a crystallized glass ceramic powder (Japan Electric Glass Co., MLS05, glass transition temperature 67
(0 ° C.) 33.4% by weight, ethyl cellulose resin as a binder 0.8% by weight, and terpineol as a solvent 15.8% by weight, respectively. Conductor paste for vias by thoroughly mixing and kneading
A strike was made.

Insulating powder (alumina + borosilicate glass powder) is 70% by weight as a raw material for an insulating paste, butyral resin + benzylbenzylphthalate is 15% by weight as a binder, and a solvent is used as a solvent. 15 wt% of butyl carbitol was prepared, and these were sufficiently mixed and kneaded with three rolls to prepare an insulating paste. The glass transition temperature of this insulator powder is 570 ° C.

A wiring pattern is formed by screen printing with a thick film conductor paste (DD1411, manufactured by Kyoto Elec Co., Ltd.) on a base film (PET) whose surface is subjected to a release treatment.
A conductive layer 2 and then an insulating layer 3 is formed with an insulating paste so as to cover the entire wiring pattern.
Was made. Transfer sheets each having a wiring pattern of each layer formed in the same order were prepared, and via holes were punched at predetermined positions of each transfer sheet. The via holes may be formed by a carbon dioxide gas laser. Next, the transfer sheet was thermally transferred onto a 96% alumina substrate under the conditions of 60 ° C. and 80 kg / cm 2, and the via conductor paste thus prepared was filled into the via hole, and then the base film was peeled off. Then, the transfer sheets were laminated to obtain a laminate.

Next, the obtained laminated body was subjected to binder removal treatment in the atmosphere in the heating furnace. The heating conditions at this time were the temperature profile shown in FIG. 1A for a peak temperature of 275 ° C. and a peak temperature time of 360 minutes.

Thereafter, the laminated body 5 was sintered and fired in the atmosphere of the heating furnace. The heating conditions were a peak temperature of 900 ° C. and a temperature profile shown in FIG. Finally, the uppermost wiring (not shown) was formed by screen printing with a thick film conductor paste (DD2332H, manufactured by Kyoto Elex Co., Ltd.) and baked in the atmosphere. The heating conditions were a peak temperature of 900 ° C. and a temperature profile shown in FIG. The via hole 2 of the multilayer wiring board thus obtained has a dense structure that is firmly adhered to the inner wall of the via hole 2 without disconnection at the contact portion with the conductor layer 3 or voids inside the via hole 2. Via conductor 1
Could be formed. The volume resistance of this is 2.7E-4 ohm.
It was cm. FIG. 2A shows a cross section of a portion of the via conductor 1 obtained in this example.

A multi-layer wiring board was manufactured in the same manner by preparing a via conductor paste in which the ratio of silver and glass ceramic was changed. At this time, in the case of using a via conductor paste (which has a large glass ceramic component) in which the proportion of silver is not more than 30% by weight, the cross section is as shown in FIG.
A via having a structure as shown in (a) was formed, but conduction could not be obtained because the glass component was too much. on the other hand,
A via conductor paste having a silver content of more than 70% by weight (mostly silver) was used, and the via had a structure as shown in FIG. 2B.

(Example 2) As a raw material for a conductor paste for vias, 50.0% by weight of copper oxide powder having an average particle size of about 3 microns (manufactured by Kyoto Elex Co., Ltd., CB250 crushed), glass powder (NEC) Glass, MLS05, glass transition temperature 670 ° C.) 33.4% by weight, ethyl cellulose resin as a binder 0.8% by weight, terpineol as a solvent 15.8% by weight, respectively. Then, these were sufficiently mixed and kneaded with three rolls to prepare a conductor paste for vias.

As a raw material for the conductor paste, copper oxide powder having an average particle size of about 3 microns (manufactured by Kyoto Elex Co., CB2)
50 crushed) 85.5% by weight, butyra as a binder
Prepare 11.5% by weight of resin and benzyl butyl phthalate, and 3% by weight of butyl carbitol as a solvent, and sufficiently mix and knead them with 3 rolls to make wiring. A conductor paste was produced.

As a raw material for the insulating paste, 70% by weight of the same insulating powder as in (Example 1), 15% by weight of butyral resin + benzyl butyl phthalate as a binder, and as a solvent were used. 15 wt% of butyl carbitol was prepared, and these were sufficiently mixed and kneaded with three rolls to prepare an insulating paste.

A wiring pattern (conductor layer 3) is formed by screen printing with a wiring conductor paste prepared on a base film (PET) whose surface has been subjected to a mold release treatment, and further an insulator pattern. An insulating layer 4 was formed so as to cover the entire wiring pattern with a strike, and a transfer sheet was produced. Transfer sheets each having a wiring pattern of each layer formed in the same order were prepared, and via holes were formed at predetermined positions of each transfer sheet by a carbon dioxide gas laser. The via holes may be punched by punching. Next, transfer the sheet onto a 96% alumina substrate at 60 ° C,
Thermal transfer was carried out under the condition of 80 kg / cm @ 2, the prepared via conductor paste was filled in the via holes, the base film was peeled off, and the transfer sheets were laminated in the same order to obtain a laminate. Next, the obtained laminated body was subjected to binder removal treatment in the air in the heating furnace. The heating condition at this time is a peak temperature of 450.
The temperature profile was as shown in FIG. 1C at a temperature of 120 ° C. for a peak temperature of 120 minutes.

Thereafter, reduction treatment of copper oxide, which is a conductor component in the laminate, was performed in a hydrogen gas atmosphere in a heating furnace. The heating conditions are a peak temperature of 350 ° C and a peak temperature of 1 hour.
The temperature profile shown in FIG. 1D for 80 minutes was used.

Further, the laminate was sintered and fired in a nitrogen gas atmosphere in a heating furnace. The heating conditions are a peak temperature of 900 ° C,
The peak temperature was 10 minutes, and the temperature profile was as shown in FIG. The via of the multilayer wiring board thus obtained does not cause disconnection at the contact portion between the via conductor 1 and the wiring conductor 2 or a void inside the via hole, and the via conductor 1 having a dense structure firmly adhered to the inner wall of the via hole. Could be formed. The volume resistance of the via conductor was 3.0E-4 ohm · cm. Figure 2
A schematic view of the cross section of the via portion obtained in this example is shown in (a).

A multilayer wiring board was manufactured in the same manner by making the via conductor paste in which the ratio of copper oxide and glass was changed. At this time, in the case of using a via conductor paste (having a large glass-ceramic component) in which the proportion of copper oxide is not more than 30% by weight, a via having a structure as shown in FIG. Although formed, conduction was not obtained because there were too many glass components. On the other hand, in the case of using a via conductor paste (copper content is large) in which the proportion of copper oxide exceeds 70% by weight, the via has a structure as shown in FIG. 2B.

(Embodiment 3) 50.0% by weight of a ruthenium oxide powder (manufactured by Tanaka Kikinzoku Co., Ltd.) having an average particle diameter of about 1 micron and a crystallized glass ceramic powder (NEC) Glass company, MLS05) 3
3.4% by weight, 0.8% by weight of ethyl cellulose resin as a binder, and 1% of terpineol as a solvent.
5.8% by weight of each was prepared, and these were sufficiently mixed and kneaded with three rolls to prepare a via conductor paste.

As a raw material for the conductor paste, copper oxide powder having an average particle size of about 1 to 3 microns (Kyoto Elex Co., C
(B250 pulverized), 85.5% by weight, butyral resin + benzyl butyl phthalate as a binder, 11.5% by weight, and butyl carbitol as a solvent, 3% by weight were prepared. Sufficiently mixed and kneaded with this roll to prepare a conductor paste. As a raw material for the insulating paste, 70% by weight of the same insulating powder as in (Example 1), 15% by weight of butyral resin + benzyl benzyl phthalate as a binder, and butyl carbitol as a solvent were used. 15 wt% was prepared, and these were thoroughly mixed and kneaded with three rolls to prepare an insulating paste.

A wiring pattern (conductor layer 3) is formed by screen printing with a conductor paste prepared on a base film (PET) whose surface has been subjected to a release treatment, and further an insulator pattern. The insulating layer 4 was formed so as to cover the entire wiring pattern with a strike, and a transfer sheet was produced. In the same order, transfer sheets each having a wiring pattern formed on each layer were prepared, and each transfer sheet was formed.
Via holes were drilled at predetermined locations on the substrate using a carbon dioxide laser. The via holes may be punched by punching.
Next, a transfer sheet was placed on a 96% alumina substrate at 60 ° C and 80 ° C.
Thermal transfer was carried out under the condition of kg / cm @ 2, the prepared via conductor paste was filled in the via holes, the base film was peeled off, and the transfer sheets were laminated in the same order to obtain a laminate.

Next, the obtained laminated body was subjected to binder removal treatment in the air in a heating furnace. The heating conditions at this time were the temperature profile shown in FIG. 1C for a peak temperature of 450 ° C. and a peak temperature time of 120 minutes.

Thereafter, reduction treatment of copper oxide, which is a conductor component in the laminate, was performed in a hydrogen gas atmosphere in a heating furnace. The heating conditions are a peak temperature of 350 ° C and a peak temperature of 1 hour.
The temperature profile shown in FIG. 1D for 80 minutes was used.

Further, the laminate was sintered and fired in a nitrogen gas atmosphere in a heating furnace. The heating conditions are a peak temperature of 900 ° C,
The peak temperature was 10 minutes, and the temperature profile was as shown in FIG. The via of the multilayer wiring board thus obtained does not cause disconnection at the contact portion between the via conductor 1 and the wiring conductor 2 or voids inside the via hole as in the case of (Example 1) or (Example 2). It was possible to form the via conductor 1 having a dense structure that was firmly adhered to the inner wall of the hole. The volume resistance of this is 2.3E-
It was 3 ohm · cm.

A multilayer wiring board was manufactured in the same manner by making the via conductor paste in which the ratio of ruthenium oxide and glass ceramic was changed. At this time, in the case of using a via conductor paste (having a large glass ceramic component) in which the ratio of ruthenium oxide is 30% by weight or more, a via having a structure as shown in FIG. Although formed, conduction was not obtained due to too much glass ceramic component. On the other hand, in the case of using a via conductor paste (mostly ruthenium) having a ruthenium oxide ratio of more than 70% by weight, a via having a structure as shown in FIG.

In the above (Example 1) to (Example 3), an insulating layer material having a glass transition temperature of 570 ° C. and a glass conductor having a softening temperature of 670 ° C. in the via conductor were used. This is not limited by the composition as long as it is 570 ° C. or higher. However,
As can be easily inferred, the firing temperature required for the insulating layer material and the wiring conductor material (900 ° C. in the above examples) from the characteristic points of view such as strength, insulation resistance, wiring resistance and reliability. In the following, it must be a glass-ceramic to be softened.

The insulating layer material used in the above examples is a material containing alumina as filler in borosilicate glass, and this glass is borosilicate such as lead borosilicate or calcium borosilicate. In general, it is possible to use a glass having a property intended for electrical insulation, such as a salt-based glass, without any problem. As the filler, any material having excellent electrical insulating properties such as quartz or forsterite can be used in the present invention.

(Example 4) The glass ceramic in the via conductor paste shown in (Example 1) to (Example 3) was changed to MLS27 (manufactured by Nippon Electric Glass Co., Ltd., prototype, glass transition temperature 520 ° C). Instead, a via conductor paste was prepared in the same manner.

Next, in place of the insulator powder used in (Example 1) to (Example 3), an insulator powder (alumina + quartz + lead borosilicate glass) having a glass transition temperature of 450 ° C. was used. An insulating paste was prepared and a firing temperature was set to 850 ° C. to manufacture a multilayer wiring board by the same method. The vias of the obtained multilayer wiring board had the same shape, structure and characteristics as those shown in (Example 1) to (Example 3).

In the above embodiments, an example was described in which silver, copper and ruthenium were used as the conductive components of the via conductor. The conductive components include the types of insulating layer material and wiring conductor material, and Depending on the heat treatment process conditions required by
Platinum, platinum-palladium, gold, nickel or the like can be selected and used.

It is needless to say that the present invention can be applied not only to the thermal transfer method as in the above embodiment but also to the green sheet method as a laminating method. Therefore, the present invention is not limited to the ceramic multilayer wiring board. In addition, it can be widely applied to the manufacture of electronic components that require conduction between wiring layers.

[0034]

INDUSTRIAL APPLICABILITY As described above, according to the present invention, the conductor for vias is made of crystallized glass ceramic powder having a conductive material powder of 30.0 to 70.0% by weight and a glass transition temperature higher than the glass transition temperature of the insulating material. Since the conductor paste composition including the inorganic component composed of 30.0 to 70.0% by weight and the organic vehicle component composed of at least the organic binder and the solvent is used, the insulating material forming the via hole is softened and sintered. After the via hole is formed, the glass component in the via conductor material inside the via hole is softened and the via conductor is sintered, so that no disconnection at the via conductor portion or a void does not occur inside the via hole. It is possible to form a highly reliable via conductor having a precise structure that is firmly attached to the hole.

[Brief description of drawings]

1A is a relationship diagram showing a temperature profile of a binder removal step in a method for manufacturing a multilayer wiring board according to an embodiment of the present invention, and FIG. 1B is a relationship diagram showing a temperature profile of a sintering / firing step similarly. (c) is a relationship diagram showing the temperature profile of the binder removal process (d) is a relationship diagram showing the temperature profile of the reduction process

FIG. 2A is a schematic diagram of a via cross section of a multilayer wiring board according to an embodiment of the present invention. FIG. 2B is a schematic diagram of a via cross section of the multilayer wiring board.

[Explanation of symbols]

 1 Via conductor 2 Via hole 3 Conductor layer 4 Insulating layer 5 Laminated body

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yuu Kiyoshi 1006 Kadoma, Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Inventor, Yasuhiko Hakotani, 1006 Kadoma, Kadoma, Osaka (72) Inventor Kazuhiro Miura 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (2)

[Claims] 1. A conductor conductor for a via of a ceramic multilayer wiring board.
In the strike, conductive material powder 30.0-70.0% by weight
And a crystallized glass ceramic powder having a glass transition temperature higher than the glass transition temperature of the insulating material 30.0 to 70.
A conductor paste composition comprising 0% by weight of an inorganic component and an organic vehicle component comprising at least an organic binder and a solvent. 2. The conductor paste composition according to claim 1, wherein the conductor material is silver, copper oxide, ruthenium oxide, gold, copper, palladium, platinum, nickel, or an alloy thereof.