JP2578273B2 - Method for manufacturing multilayer electrode substrate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a multilayer electrode substrate such as a ceramic package, a multilayer wiring substrate or a multilayer ceramic capacitor.

[0002]

2. Description of the Related Art A multilayer electrode substrate such as a ceramic package, a multilayer wiring board or a multilayer ceramic capacitor is formed by depositing gold,
A conductive paste containing one or more metal powders of silver, palladium, platinum, copper or nickel is printed. After laminating a plurality of dielectric green sheets on which these conductive pastes are printed, collectively bake at high temperature. Being manufactured.

[0003] The conductive paste used for this purpose includes:
In addition to the above metal powders, various compounds are added for the purpose of preventing warpage and delamination during firing with the dielectric green sheet. For example, in a multilayer wiring board, powder such as alumina, zirconia, or magnesia is added for this purpose, and a vitreous frit or the like is added for improving the adhesion to the dielectric green sheet.

[0004]

However, even when such various compounds are added, when the dielectric green sheets on which the conductive paste is printed are laminated and fired at a time, the conductive green sheets and the dielectric paste are not mixed. Similarly, as a result of not shrinking, so-called delamination, in which the substrate is warped or the inner layer conductor and the dielectric green sheet partially shrink, occurs. This is due to the difference between the shrinkage start temperature of the dielectric green sheet and the conductive paste, the shrinkage speed during shrinkage, and the final shrinkage rate.

[0005] Further, these warpage and delamination become more remarkable as the number of laminated bodies increases, and as a result, the yield of laminated and fired laminated bodies naturally declined. SUMMARY OF THE INVENTION The present invention has been made in view of such problems of the prior art, and an object of the present invention is to provide a method of manufacturing a multilayer electrode substrate without warping or delamination of a substrate due to firing. Is to do.

[0006]

In order to achieve the above object, the gist of the present invention is to print a conductive paste composition on a substrate, stack a plurality of printed substrates, and fire the multilayer electrode substrate. In the method for producing, the conductive paste composition comprises one or more metal powders of gold, silver, palladium, platinum, copper, or nickel, and an organic vehicle required to paste the metal powders; _4-n Si (O
R ′) _n (where R and R ′ each represent an alkyl group or an aryl group, and n is an integer of 1 or more and 4 or less) (hereinafter referred to as “the present compound”). ), And the compounding amount of the present compound is 0.01 to 5 parts by weight in terms of SiO _{2 with} respect to 100 parts by weight of the metal powder. It is in.

The method of adding the present compound to the conductive paste is as follows.
Either "whether the present compound itself is mixed in a conductive paste" or "whether the metal powder is treated in a solution containing the present compound and then the treated powder is formed into a paste" may be used.

The method for producing the present compound will be described. For example, one or more alkoxysilane compounds such as monomethyltrimethoxysilane and dimethyldiethoxysilane are used.
It can be produced by adding water and hydrolyzing in an organic solvent in which an alkoxysilane compound such as isopropyl alcohol and butyl carbitol acetate is dissolved. During the hydrolysis, an acid catalyst such as nitric acid or an organic acid may be added. Further, the reaction temperature can be increased for the purpose of increasing the reaction rate. When the reaction proceeds, hydroxysilane (R
_4-n Si (OH) _n ) is produced. (Details of these production methods are described in JP-A-63-241076.
No. JP-A-63-297468).
The average particle size of the silver, palladium, platinum, copper or nickel powder is preferably 5 μm or less, and the shape of the powder is not particularly limited. Also, the organic vehicle is not particularly limited as long as it can be made into a paste.

[0009]

When the present compound is contained in the conductive paste, the shrinkage of the green sheet and the shrinkage of the conductive paste can be matched during firing of the green sheet. That is, it is considered that the present compound is thermally decomposed during firing to produce silica fine particles, and the silica fine particles are uniformly dispersed between the metal particles, thereby controlling the sintering of the metal powder.

Further, since the present compound is in a liquid state, it is easily dissolved uniformly in a paste. Further, the R group (alkyl group or aryl group) of R _4-n Si has good compatibility with an organic vehicle. The dispersion stability of the metal powder in the oxidized state is improved.

Further, the OH group bonded to the silicon atom has a high affinity for the surface of the metal powder and uniformly covers the surface of the metal powder. Therefore, the metal powder 100
The compounding amount of the present compound relative to parts by weight may be 0.01 parts by weight or more in terms of SiO ₂ . However, when the amount is less than 0.01 part by weight, the effect of the sintering control is small.
Exceeding the weight part is not preferred because the sintering of the metal powder is suppressed too much and the resistance value becomes too high.

As described above, by adding 0.01 to 5 parts by weight of the present compound in terms of SiO _{2 with} respect to 100 parts by weight of the metal powder, sintering of the metal powder is appropriately suppressed, and Warpage and delamination do not occur.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on embodiments.

Example 1 After adding tetramethoxysilane and dimethyldimethoxysilane to butyl carbitol acetate, distilled water was added dropwise with stirring at room temperature to obtain 20 parts by weight of the present compound in terms of SiO _2. Synthesized. Then, this compound was pasted into 100 parts by weight of silver powder having an average particle diameter of 1.3 μm by adding 0 to 10 parts by weight in terms of SiO ₂ and an appropriate amount of an organic vehicle (a solution of terpineol in ethyl cellulose). . A three-roll mill was used for making the paste, and the viscosity of the paste was 100,000 cps to 400,000 cps. Next, the paste was printed on a green sheet for a borosilicate glass-alumina ceramic mixed low-temperature fired substrate, debindered at 500 ° C, and fired at 900 ° C for 1 hour. Then, the warpage of the substrate and the resistance value of the baked conductor were measured.

The warpage of the substrate was measured by printing a 10 mm × 10 mm pad on one green sheet, and firing and firing the surface of the green sheet fired body on the side where the conductor was printed and the unevenness of the printed conductor. It was determined by measuring the distance to the top. Positive when the conductor was convex from the surface of the green sheet fired body, and negative when it was concave. Further, the resistance value of the conductor was determined by the specific resistance from the pattern printed on the uppermost layer of the green sheet laminate.

The warpage (×) and the specific resistance (○) of these substrates
Is shown in FIG. As shown in FIG. 1, the warpage is large in the case where the present compound is not added, but the warpage is significantly reduced when the present compound is added in an amount of 0.01 part by weight, and no large warp occurs when the addition amount is up to 5 parts by weight. However, if 10 parts by weight is added, a large warp occurs on the minus side. The specific resistance is 5
Addition of up to 10 parts by weight is very small, but addition of 10 parts by weight greatly suppresses the sintering of silver powder, and increases the specific resistance.

Further, this compound is used in an amount of 0.1 in terms of SiO ₂ .
When 30 green sheets printed with the conductor paste to which 5 parts by weight were added were laminated and fired, no warpage was observed, and the specific resistance of the conductor was as low as 2 μΩ · cm, which was a very good result. Delamination did not occur at all in the SEM observation of the cross section of the laminate.

As described above, the compound of the present invention exhibits an excellent effect of suppressing the warpage of a substrate even when added in a small amount. However, when a silane coupling agent or powdered silica is used as a silane compound, these compounds also cause sintering of metal powder. However, the amount of the compound added is considerably larger than that of the present compound. As a result, good conductivity, which is one of the characteristics of the conductive paste, is impaired, and the resistance value is greatly increased.

Example 2 A paste was prepared in the same manner as in Example 1 except that spherical nickel powder having an average particle diameter of 0.3 μm was used in place of the silver powder of Example 1. FIG.
Is the result of applying this paste to a barium titanate-based green sheet for a multilayer ceramic capacitor (the meanings of x and o are the same as in FIG. 1). After debinding at 350 ° C (in air), the green sheet is 1250 ° C
For 2 hours in nitrogen. As shown in FIG. 2, this green sheet also shows the same tendency as FIG.
It can be seen that the addition of this compound has a very effective effect on suppressing the warpage of the green sheet.

Further, a green sheet printed with a conductive paste obtained by adding 1 part by weight of the present compound in terms of SiO ₂ was prepared.
Even when 00 sheets were laminated and fired, neither warpage nor delamination was observed, and good results were shown.

[0021]

According to the present invention, it is possible to provide a method for manufacturing a multilayer electrode substrate which does not cause warpage or delamination of the substrate due to firing.

[Brief description of the drawings]

FIG. 1 is a graph showing the effect of the amount of the present compound on the warpage and specific resistance of a green sheet for a low-temperature fired multilayer substrate.

FIG. 2 is a graph showing the effect of the amount of the present compound on the warpage and specific resistance of a green sheet for a multilayer ceramic capacitor.

 ────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yamao Kiryu 27-13 Wakabadai, Otsu City, Shiga Prefecture (56) References JP-A-1-189806 (JP, A) JP-A-55-62938 (JP, A) JP-A-3-122162 (JP, A) JP-A-57-155386 (JP, A) JP-A-63-115252 (JP, U)

Claims (1)

(57) [Claims] (1) printing a conductive paste composition on a substrate,
After laminating a plurality of printed substrates, firing is performed to form a multilayer electrode substrate.
In the method for producing a plate, the conductive paste composition
But gold, silver, palladium, platinum, copper, or an organic vehicle necessary to paste at least one metal powder and the metal powder in the _{nickel, R 4-n Si (OR} ')
_n (where R and R ′ each represent an alkyl group or an aryl group, and n is an integer of 1 or more and 4 or less), and a compound obtained by hydrolyzing an alkoxysilane compound represented by the formula: The compounding amount of the decomposed compound is 0.02 in terms of SiO _{2 with} respect to 100 parts by weight of the metal powder.
1 to 5 parts by weight of a multilayer electrode substrate
Construction method .