JPH08125307A - Manufacture of ceramic wiring board - Google Patents

Abstract

PURPOSE: To provide a manufacturing method of a ceramic wiring board for forming a conductor layer by applying electroless copper plating wherein a conductor layer with stable and firm adhesion can be formed on a smooth ceramic substrate surface which is not roughened without requiring a special atmosphere such as a reducing atmosphere. CONSTITUTION: A ceramic wiring board is manufactured by forming a foundation layer containing bismuth and copper on the surface of a ceramic substrate, thermally treating it at 600 to 1100 deg.C in an oxidative atmosphere, immersing it in a reducing solution for reduction treatment and applying electroless copper plating to it.

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 ceramic wiring board used as, for example, an electronic component, and more particularly to a method for manufacturing a ceramic wiring board in which a conductor layer is formed by electroless copper plating.

[0002]

2. Description of the Related Art Conventionally, when a conductor layer is formed by electroless copper plating on the surface of a ceramic substrate, a chemical etching method such as immersing the ceramic substrate in a high temperature solution of hydrofluoric acid, phosphoric acid, sodium hydroxide or the like is used. By roughening the surface of the ceramic substrate by the method, it is common to secure the adhesion between the conductor layer and the ceramic substrate by the so-called anchor effect.

However, since roughening the surface of the ceramic substrate impairs the high frequency characteristics, a method of manufacturing a ceramic wiring board in which a conductor layer firmly adhered to the surface of the ceramic substrate which is as smooth as possible can be formed. Development is desired. Therefore, as a method of forming a conductor layer having excellent adhesiveness without roughening, various studies have been conducted on pretreatment of electroless copper plating, formation of an underlayer, and the like, for example, Japanese Patent Publication No. 63-4336. Japanese Patent Publication No. 4-82043 and Japanese Patent Publication No. 3-69191 are proposed.

Japanese Examined Patent Publication No. 63-4336 describes Cu, Z.
A paste containing at least one component of a compound of n, Cd, Pb or Bi is applied to a ceramic substrate, and then,
Cu, Zn, Cd, Pb and Bi are heat-treated at a temperature in the range of 350 to 900 ° C. in a non-oxidizing atmosphere.
Of at least one kind of metal or alloy, and then a substitution treatment of substituting at least one of Pd and Pt on the surface of the metal of the above metal or alloy in a solution containing ions of at least one of Pd and Pt. A method of manufacturing a ceramic electronic component is described, which comprises applying a metal electrode of nickel, cobalt or copper by electroless plating. However, in this case, since heat treatment in a non-oxidizing atmosphere is required, there is a problem in that the manufacturing apparatus and manufacturing process are complicated, and further, by the substitution treatment of substituting at least one of Pd and Pt, It is presumed that the adhesion between the underlayer and the ceramic substrate is impaired,
As seen in the example of Japanese Examined Patent Publication No. 63-4336, the maximum tensile strength is 2.75 kg / 5φ area (0.53
It is about kg / 4 mm ² ) and in recent years, further improvement in adhesion has been demanded.

In Japanese Examined Patent Publication No. 4-82043, a metal thin film is formed on a ceramic surface by electroless plating, and then 900-1
A method of heat-treating at 200 ° C. to form a chemical bond between the ceramic and the metal thin film, then chemically etching to remove the metal thin film, and then metallizing the ceramic surface by electroless plating. Is listed. However, in the case of this method, the adhesion tends to largely depend on the film thickness of the formed metal thin film, and there is a problem that it is difficult to obtain a stable adhesion.

In Japanese Examined Patent Publication No. 3-69191, electroless copper plating is applied to an alumina substrate, and then 300-900.
A method is described in which heat treatment is performed at 0 ° C. in an oxidizing atmosphere, further at 200 to 900 ° C. in a reducing atmosphere, electroless copper plating is performed, and then electrolytic copper plating is performed. However, in the case of this method, since the treatment is performed in a reducing atmosphere, the manufacturing apparatus and the manufacturing process are complicated, and the reduction treatment is performed at a high temperature of 200 to 900 ° C., and thus the obtained metal film is obtained. It is presumed that the wettability of the surface of No. 3 is low, but there was a problem that the adhesion between the underlayer after the reduction treatment and the electroless copper plating film formed thereon was insufficient.

[0007]

In view of the above circumstances,
The present invention is a method for producing a ceramic wiring board in which a conductor layer is formed by applying electroless copper plating, does not require a special atmosphere such as a reducing atmosphere, and is not roughened, and is smooth. It is an object of the present invention to develop a manufacturing method of a ceramic wiring board capable of forming a conductor layer having stable and strong adhesion on the surface of a ceramic substrate.

[0008]

According to a first aspect of the present invention, there is provided a method for producing a ceramic wiring board, wherein an underlayer containing bismuth and copper is formed on the surface of a ceramic substrate, and then in an oxidizing atmosphere. It is characterized in that it is heat-treated at 600 to 1100 ° C., then immersed in a reducing solution for reduction treatment, and then electroless copper plating is performed.

According to a second aspect of the present invention, there is provided a method for producing a ceramic wiring board according to the first aspect, wherein the method for forming an underlayer containing bismuth and copper is the same as the method for producing a ceramic wiring board according to the first aspect. The method is characterized in that it is formed by coating the surface of a ceramic substrate with a material containing.

According to a third aspect of the present invention, there is provided a method for manufacturing a ceramic wiring board according to the first aspect, wherein the method for forming an underlayer containing bismuth and copper is the copper-containing layer on the surface of the ceramic substrate. Is formed, and then a bismuth-containing layer is formed on the copper-containing layer.

According to a fourth aspect of the present invention, there is provided a method for producing a ceramic wiring board according to the first aspect, wherein the method for forming an underlayer containing bismuth and copper is the bismuth-containing layer on the surface of a ceramic substrate. Is formed, and then a copper-containing layer is formed on the bismuth-containing layer.

A method for manufacturing a ceramic wiring board according to a fifth aspect of the present invention is the method for manufacturing a ceramic wiring board according to any one of the first to fourth aspects, wherein copper is used to form an underlayer containing bismuth and copper. The component is a metal copper powder treated with an ethylenediamine-based chelating agent.

A method of manufacturing a ceramic wiring board according to a sixth aspect of the present invention is the method of manufacturing a ceramic wiring board according to any one of the first to fourth aspects, wherein copper is used to form an underlayer containing bismuth and copper. The component is a metal copper powder deposited from an electroless plating solution containing an ethylenediamine-based chelating agent.

The present invention will be described in detail below. Examples of the material of the ceramic substrate used in the present invention include oxide-based ceramics such as alumina, zirconia, cordierite, and barium titanate; aluminum nitride; nitride-based ceramics such as silicon nitride; and carbide-based materials such as silicon carbide. There is no particular limitation.

An underlayer containing bismuth and copper is formed on the surface of the above-mentioned ceramic substrate. The following three kinds of forming methods can be exemplified, and the underlayer containing bismuth and copper can be formed. If there is no particular limitation. For example, a method of coating a material containing both metal components of bismuth and copper, such as a mixed resinate paste obtained by mixing a bismuth resinate paste and a copper resinate paste, to form a layer in which bismuth and copper are mixed in a single step. A method of forming a base layer containing bismuth and copper by forming a copper-containing layer and then forming a bismuth-containing layer on the copper-containing layer. A method of forming a base layer containing bismuth and copper by forming a bismuth-containing layer and then forming a copper-containing layer on the bismuth-containing layer.

The means for forming the copper-containing layer, the bismuth-containing layer, and the layer containing both bismuth and copper for forming the underlayer containing bismuth and copper are not particularly limited. For example, electroless plating is used. , A sputtering method, a metal paste method, an organic metal resinate (or a paste thereof) method, or the like. In the case of the method of independently forming the copper-containing layer and the bismuth-containing layer like the method of and, the copper-containing layer is formed only on the portion to be the circuit pattern, and the bismuth-containing layer is formed on the entire surface of the ceramic substrate. If formed, bismuth oxide simple substance (metal bismuth is partially present) is formed in the portion other than the circuit pattern portion when the heat treatment and the reduction treatment are sequentially performed in the subsequent process. Electroless copper plating does not deposit on this bismuth oxide simple substance, and since the bismuth oxide simple substance can be subjected to quick etching with acid, only the bismuth-containing layer functions as a plating resist for electroless copper plating. The part that exists can be fulfilled.

Further, the thickness of the copper-containing layer, the bismuth-containing layer and the layer containing bismuth and copper for forming the underlayer containing bismuth and copper is not particularly limited. However, when the copper-containing layer is formed on the surface of the ceramic substrate as described above and then the bismuth-containing layer is formed on the copper-containing layer, the thickness of the copper-containing layer is 0.05 to 3.0.
It is preferable that the thickness is in the range of μm so that the finally obtained conductor layer has a stable adhesive force.

When the bismuth resinate paste is used, the content of bismuth in the bismuth resinate paste is preferably 10% by weight or more. When the content of bismuth is less than 10% by weight, the adhesion of the finally obtained conductor layer to the ceramic substrate is lowered, which is not preferable.

In the present invention, after forming an underlayer containing bismuth and copper on the surface of the ceramic substrate, heat treatment is performed to oxidize bismuth and copper. By this heat treatment step, bismuth oxide is diffused, and copper oxide is generated on the surface of the underlayer containing bismuth and copper. This heat treatment is 600 to 1100 ° C. in an oxidizing atmosphere such as air.
It is important to carry out at a temperature of less than 600 ° C., and at a temperature of less than 600 ° C., the adhesion of the finally obtained conductor layer to the smooth ceramic substrate surface becomes insufficient, and at a temperature of more than 1100 ° C., the thermal diffusion of copper does not occur. In the next electroless copper plating step, the copper component, which acts as a catalyst for electroless copper plating, does not remain on the outermost surface of the ceramic substrate, so that the adhesion is also insufficient.

In the present invention, the reduction treatment is performed by immersing the ceramic substrate that has undergone the above heat treatment in a reducing solution. By this step, the copper oxide existing on the surface of the underlayer containing bismuth and copper is reduced to metallic copper. This metallic copper serves as a catalyst nucleus in the subsequent electroless copper plating step, which enables desired electroless copper plating. The reducing solution is not particularly limited as long as it can reduce copper oxide, and for example, a borohydride solution, a hypophosphite solution, a dimethylamine borane solution or the like can be used. The temperature of the reducing solution is not particularly limited, but it is preferable to perform it at a temperature higher than room temperature in order to shorten the time of the reduction treatment.

Next, electroless copper plating is applied to the ceramic substrate that has undergone the above reduction treatment to form a conductor layer. If necessary, a metal layer may be further formed thereon by a method such as electroplating to form a conductor layer. The method of electroless copper plating is not particularly limited.

Further, in the present invention, the electroless plating solution containing the metal copper powder or the ethylenediamine-based chelating agent whose copper component forming the underlayer containing bismuth and copper is treated with the ethylenediamine-based chelating agent. It is preferable that the metal copper powder deposited from the above enhances the adhesion of the finally obtained conductor layer. The ethylenediamine-based chelating agent referred to in the present invention refers to an ethylenediamine-based chemical substance capable of forming a copper chelate compound, and the ethylenediamine-based chelating agent is not particularly limited, but ethylenediaminetetraacetic acid (hereinafter referred to as EDTA Abbreviated), ethylenediamine-based chelating agents such as ethylenediaminediacetic acid, and ethylenediamine-based chelating compounds such as disodium ethylenediaminetetraacetate. The method of treating with the ethylenediamine-based chelating agent is not particularly limited, but examples thereof include dipping, coating and spraying.

[0023]

In the method for manufacturing a ceramic wiring board according to the present invention, an underlayer containing bismuth and copper is formed on the surface of a ceramic substrate and then heat-treated at 600 to 1100 ° C. in an oxidizing atmosphere. Bismuth and copper oxides are formed. Bismuth oxide has good wettability to a ceramic substrate and diffuses to act as an adhesive agent to the ceramic substrate. Further, since the bismuth oxide and the copper oxide form a compound, the adhesion between them becomes strong. Furthermore, since the diffusion rate of bismuth oxide to the ceramic substrate side is higher than that of copper oxide, even if a layer containing bismuth and copper is formed by any of the above-mentioned methods, bismuth after heat treatment and An oxide layer of copper appears on the surface of the underlying layer containing copper.

In the present invention, after the heat treatment, it is immersed in a reducing solution for reduction treatment, and then electroless copper plating is performed. Therefore, after the heat treatment, the copper oxide layer appearing on the surface of the underlayer is formed. Is converted to metallic copper by the reduction treatment. This metallic copper acts as a plating catalyst in the electroless copper plating in the next step. Further, the fact that the diffusion rate of bismuth oxide is higher than that of copper oxide has the effect of reducing the degree to which the variation in the film thickness of the underlayer affects the adhesive force, so that a stable adhesive force can be obtained.

Then, as in the above methods and
When the copper-containing layer and the bismuth-containing layer are formed independently, the bismuth-containing layer is formed on the entire surface of the ceramic substrate,
If the copper-containing layer is formed only on the portion that will be the circuit pattern, the portion where only the bismuth-containing layer is formed does not deposit electroless copper plating, and thus functions as a plating resist for electroless copper plating. be able to.

Further, in the present invention, the copper component forming the underlayer containing bismuth and copper is deposited from the metal copper powder treated with the ethylenediamine-based chelating agent or the electroless plating solution containing the ethylenediamine-based chelating agent. Since the copper chelate compound is formed on the surface of the metal copper powder, it is difficult for the copper oxide to be completely CuO when heat-treated at 600 to 1100 ° C. in an oxidizing atmosphere. As a result, the copper oxide layer is liable to be converted to metallic copper in the subsequent reduction treatment. Therefore, the metallic copper obtained by the reduction treatment reliably acts as a plating catalyst in the electroless copper plating in the next step, and can firmly bond with the copper film to be formed, and the adhesive force of the conductor layer. Can be improved.

[0027]

EXAMPLES Specific examples and comparative examples of the present invention will be shown below.

(1) Examples in which an underlayer was formed by coating using a material containing both metal components of bismuth (abbreviated as Bi hereinafter) and copper (Examples 1 to 5) The Bi resinate paste (manufactured by NE Chemcat, # 8365, Bi content 20
%) 2 parts by weight and 8 parts by weight of copper resinate paste (manufactured by NE Chemcat, # 29-B, Cu content 6%) are mixed to print a mixed resinate paste to form a circuit pattern. Drying was carried out at 125 ° C. for 10 minutes to form a base layer in which Bi and copper were mixed.
Then, this substrate was heat-treated in the atmosphere at 850 ° C. for 1 hour, and then at 80 ° C. sodium borohydride aqueous solution (p
H12.5) was immersed for 5 minutes for reduction treatment.

Electrolytic copper plating was applied to the substrate after the reduction treatment, and a copper plating film having a thickness of 10 μm was thickly formed on the circuit pattern to form a conductor layer, and a ceramic wiring board was obtained. The adhesion between the ceramic substrate and the conductor layer in the obtained ceramic wiring board was measured. To measure the adhesion of the conductor layer, as shown in FIG. 1, a test piece obtained by joining a 0.7 mmφ tin-plated copper wire 4 with a solder 3 to a 2 mm square conductor layer 2 formed on a ceramic substrate 1 was used. I did it. The arrow in FIG. 1 indicates the pulling direction of the pulling test.
Table 1 shows the measurement results of the obtained adhesion force. From the results in Table 1, it can be seen that good adhesion is obtained in Examples 1 to 5.

[0030]

[Table 1]

(2) Examples in which a copper-containing layer is formed, and then a Bi-containing layer is formed on the copper-containing layer to form an underlayer (Examples 6 to 15) Surface roughening treatment is performed. Not shown, various ceramic substrate surfaces shown in Table 2 are nucleated with a Pd component, and then electroless copper plating is performed to form a copper-containing layer (metal copper film) having a thickness shown in Table 2 on the entire surface of the ceramic substrate. Formed. Then
The copper-containing layer was patterned by etching so that the copper-containing layer remained only in the portion to be the circuit pattern. After that, Bi resinate paste (N.
# 8365, made by Echemcat, Bi content 20
%) Is applied to the entire surface of the substrate by a screen printing method,
A Bi-containing layer was formed by performing a drying process at 125 ° C. for 10 minutes. Thus, a substrate was obtained in which a base layer containing Bi and copper was formed in the circuit pattern portion and only the Bi-containing layer (containing no Cu) was formed in the portion other than the circuit pattern portion.

After that, the substrate was heat-treated in the atmosphere at 850 ° C. for 1 hour and then immersed in an aqueous sodium borohydride solution (pH 12.5) at 80 ° C. for 5 minutes to carry out a reduction treatment. The substrate after the reduction treatment was subjected to electroless copper plating, and a copper plating film having a thickness of 10 μm was thickly formed on the circuit pattern to form a conductor layer. Since the portions other than the circuit pattern portion were covered with the simple substance of Bi oxide produced by the heat treatment (the Bi oxide was not reduced in the reduction treatment), deposition of electroless copper plating was observed at that portion. However, it was confirmed that the portion where only the Bi-containing layer was formed fulfilled the function of the plating resist for electroless copper plating.

Then, the simple substance layer of Bi oxide formed on the portion other than the circuit pattern portion was subjected to quick etching with an acid solution to obtain a ceramic wiring board. The adhesion of the conductor layer in the obtained ceramic wiring board was measured by the same method as in the above-mentioned Examples 1 to 5, and the obtained measurement results are shown in Table 2. From the results in Table 2, it can be seen that good adhesion is obtained in Examples 6 to 15.

[0034]

[Table 2]

(3) Examples in which a Bi-containing layer is formed, and then a copper-containing layer is formed on the Bi-containing layer to form an underlayer (Examples 16 to 25). Surface roughening treatment is performed. For various ceramic substrates shown in Table 3, Bi resinate paste (N.
# 8365, made by Echemcat, Bi content 20
%) Was screen-printed and dried, or the surface of the ceramic substrate was nucleated with a Pd component, and then electroless Bi plating was applied to form a Bi-containing layer on the entire surface of the ceramic substrate. The method for forming the Bi-containing layer in each example is as shown in Table 3.

Then, copper resinate paste (# 29-B, manufactured by NE Chemcat, Inc., Cu content 6%)
Is printed and dried to form a copper-containing layer only on a portion to be a circuit pattern, a base layer containing Bi and copper is formed on the circuit pattern portion, and a Bi-containing layer is formed on the non-circuit pattern portion. A substrate on which a layer (containing no copper) was formed was obtained.

Thereafter, the above substrate was heat-treated in the atmosphere at 850 ° C. for 1 hour, and then immersed in an aqueous sodium borohydride solution (pH 12.5) at 80 ° C. for 5 minutes to carry out a reduction treatment. The substrate after the reduction treatment was subjected to electroless copper plating, and a copper plating film having a thickness of 10 μm was thickly formed on the circuit pattern to form a conductor layer. Since the portions other than the circuit pattern portion were covered with the simple substance of Bi oxide produced by the heat treatment (the Bi oxide was not reduced in the reduction treatment), deposition of electroless copper plating was observed at that portion. However, it was confirmed that the portion where only the Bi-containing layer was formed fulfilled the function of the plating resist for electroless copper plating.

Next, the simple substance layer of Bi oxide formed on the portion other than the circuit pattern portion was subjected to quick etching with an acid solution to obtain a ceramic wiring board. The adhesion of the conductor layer on the obtained ceramic wiring board was measured by the same method as in the above-mentioned Examples 1 to 5, and the obtained measurement results are shown in Table 3. From the results of Table 3, it can be seen that good adhesion is obtained in Examples 16 to 25.

[0039]

[Table 3]

(4) Of the manufacturing conditions of Example 7 above,
Examples in which the Bi content in the Bi resinate was changed (Examples 26 to 29) By adjusting the addition amount of the viscosity adjusting resin in the Bi resinate, the Bi content in the Bi resinate was adjusted to the amount shown in Table 4. Example 7 (the Bi content in the Bi resinate used was 2 except that the Bi resinate used was
A ceramic wiring board was obtained in the same manner as in (0%). The adhesion of the conductor layer on the obtained ceramic wiring board was measured by the same method as in the case of Examples 1 to 5 above, and the obtained measurement results are shown in Table 4 together with the values of Example 7. Show. Table 4
From the results, it can be seen that better adhesion can be obtained if the Bi content in the Bi resinate is 10% or more.

[0041]

[Table 4]

(5) Examples and Comparative Examples (Examples 30 to 33 and Comparative Examples 1 to 3) in which the heat treatment temperature and the heat treatment time were changed among the manufacturing conditions of the above-mentioned Example 16 (in the air) A ceramic wiring board was obtained in the same manner as in Example 16 (heat treatment temperature 850 ° C.) except that the heat treatment temperature and the heat treatment time for heat treatment were carried out under the conditions shown in Table 5. The adhesion of the conductor layer in the obtained ceramic wiring board was measured by the same method as in the case of Examples 1 to 5 above, and the obtained measurement results are shown in Table 5 together with the values of Example 16. Show.

From the results shown in Table 5, the heat treatment temperature was 600 to 1
It can be seen that good adhesion can be obtained in the range of 100 ° C. In the present invention, it is desirable to set an appropriate heat treatment time for each heat treatment temperature to be set.

[0044]

[Table 5]

(6) Example of Using Metallic Copper Powder Treated with Ethylenediamine-Based Chelating Agent as Copper Component for Forming Underlayer Containing Bi and Copper (Examples 34 and 35) In Example 34, , An alkaline saturated aqueous solution of ethylenediaminetetraacetic acid disodium (abbreviated as EDTA · 2Na) was prepared, and metallic copper powder having an average particle diameter of 1 μm was added to this EDTA ·
A metallic copper powder treated with an ethylenediamine-based chelating agent was produced by immersing in a 2Na solution, stirring, filtering and drying. Next, 1.05 parts by weight of this treated copper metal powder and Bi resinate paste (N.
# 8365, made by Echemcat, Bi content 20
%) 2 parts by weight to prepare a mixed paste. Then, a ceramic wiring board was obtained in the same manner as in Example 1 except that this mixed paste was used instead of the mixed resinate paste in Example 1. The adhesion of the conductor layer in the obtained ceramic wiring board was measured by the same method as in the above-described Examples 1 to 5, and the obtained measurement results are shown in Table 6 together with the values of Example 1. Show.

In Example 35, sodium borohydride was added to an electroless copper plating solution containing EDTA,
The electroless copper plating solution was decomposed to deposit metal copper powder. Next, 1.05 parts by weight of the obtained metal copper powder and Bi
Resinate paste (manufactured by NE Chemcat,
# 8365, Bi content 20%) and 2 parts by weight were mixed to prepare a mixed paste. Then, a ceramic wiring board was obtained in the same manner as in Example 1 except that this mixed paste was used instead of the mixed resinate paste in Example 1. The adhesion of the conductor layer in the obtained ceramic wiring board was measured by the same method as in the above-mentioned Examples 1 to 5, and the obtained measurement results are shown in Table 6.

From the results in Table 6, Example 34 and Example 3
It can be seen that in No. 5, even better adhesion was obtained as compared with Example 1.

[0048]

[Table 6]

[0049]

In the method for manufacturing a ceramic wiring board according to the first and second aspects of the present invention, a base layer containing Bi and Cu is formed on the surface of the ceramic substrate, and then 600 to 1100 ° C. in an oxidizing atmosphere. Heat treatment, then dipping in a reducing solution for reduction treatment, and then electroless copper plating, so a smooth ceramic substrate can be used without requiring a special atmosphere such as a reducing atmosphere. A conductor layer having stable and strong adhesion can be formed on the surface.

In the method for manufacturing a ceramic wiring board according to the inventions of claim 3 and claim 4, since the copper-containing layer and the Bi-containing layer are formed independently, Bi serving as a plating resist is formed.
Since it is possible to provide a portion in which only the containing layer is formed,
In addition to the above effects, the effect of increasing the degree of freedom in process design is also achieved.

According to the method for manufacturing a ceramic wiring board according to the invention of claims 5 and 6, the copper component forming the underlayer is a metal copper powder treated with an ethylenediamine-based chelating agent or an ethylenediamine-based chelating agent. Since it is the metal copper powder precipitated from the contained electroless plating solution, it is possible to form a conductor layer having a stronger adhesive force in addition to the above effects.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a method for measuring an adhesion force between a ceramic substrate and a conductor layer.

[Explanation of symbols] 1 ceramic substrate 2 conductor layer 3 solder 4 tin-plated copper wire

─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] December 19, 1994

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] 0045

[Correction method] Change

[Correction content]

(6) Example of Using Metallic Copper Powder Treated with Ethylenediamine-Based Chelating Agent as Copper Component for Forming Underlayer Containing Bi and Copper (Examples 34 and 35) In Example 34, , An alkaline saturated aqueous solution of ethylenediaminetetraacetic acid disodium (abbreviated as EDTA · 2Na) was prepared, and metallic copper powder having an average particle diameter of 1 μm was added to this EDTA ·
A metallic copper powder treated with an ethylenediamine-based chelating agent was produced by immersing in a 2Na solution, stirring, filtering and drying. Next, 1.05 parts by weight of this treated copper metal powder and Bi resinate paste (N.
# 8365, made by Echemcat, Bi content 20
%) 2 parts by weight to prepare a mixed paste. Then, a ceramic wiring board was obtained in the same manner as in Example 1 except that this mixed paste was used instead of the mixed resinate paste in Example 1. The adhesion of the conductor layer on the obtained ceramic wiring board was measured by the same method as in the case of Examples 1 to 5 above, and the obtained measurement results were shown.
It shows in Table 6 .

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location H05K 1/03 B 7511-4E 3/38 C 7511-4E

Claims (6)

[Claims] 1. A ceramic substrate is formed with an underlayer containing bismuth and copper on its surface, then heat treated at 600 to 1100 ° C. in an oxidizing atmosphere, and then immersed in a reducing solution. Reduction treatment, and then electroless copper plating. 2. A method of forming the underlayer containing bismuth and copper is a method of forming a material containing both metal components of bismuth and copper on the surface of a ceramic substrate. The method for manufacturing a ceramic wiring board according to claim 1. 3. The method of forming an underlayer containing bismuth and copper is a method of forming a copper-containing layer on the surface of a ceramic substrate and then forming a bismuth-containing layer on the copper-containing layer. The method for manufacturing a ceramic wiring board according to claim 1, wherein: 4. The method of forming an underlayer containing bismuth and copper is a method of forming a bismuth-containing layer on the surface of a ceramic substrate and then forming a copper-containing layer on the bismuth-containing layer. The method for manufacturing a ceramic wiring board according to claim 1, wherein: 5. The metal copper powder treated with an ethylenediamine-based chelating agent as a copper component forming an underlayer containing bismuth and copper, according to any one of claims 1 to 4. The manufacturing method of the ceramic wiring board described in. 6. A metal copper powder deposited from an electroless plating solution containing an ethylenediamine-based chelating agent as a copper component forming an underlayer containing bismuth and copper. The method for manufacturing a ceramic wiring board according to any one of 1 to 3 above.