JPH03156992A - Manufacture of ceramic printed wiring board - Google Patents

Abstract

PURPOSE:To improve the reliability of joints between thick-film resistors and plating conductors by treating a ceramic substrate with an alkaline aqueous solution containing a palladium compound as the pretreatment of electroless plating. CONSTITUTION:A ceramic substrate 5 is dipped into molten caustic soda to form thick-film resistors 1 by chemical roughening of the surface of the substrate 5. This step is followed by such a formation of a thick-film resistor layer 2 as to overlap both ends of a thick-film resistor layer 1 and by such a formation of a thick-film 3 as to coat the entire surface of the thick-film resistor layer 2 for its protection. A plating conductor circuit pattern 4 is formed on a thick-film conductor element layer 1, thick-film resistor layer 2, thick-film insulator layer 1, and the ceramic substrate 5 after formation of a thick-film insulator layer 3 so as to overlap the thick-film conductor terminal layer 1. At this time, the substrate is treated with an alkaline aqueous solution as the pretreatment of electroless plating. This way enables formation of conductor patterns without affecting thick-film conductor layers, thereby improving the reliability of joints between thick-film resistors and plating conductors.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a method of manufacturing a ceramic printed wiring board,
Specifically, the present invention relates to a method of manufacturing a ceramic printed wiring board provided with at least a thick film resistor layer and a conductor pattern formed by plating.

(Prior Art) Electroless plating on a ceramic substrate whose surface has been roughened in advance has already been disclosed in ``Japanese Unexamined Patent Publication No. 18885/1985''. Furthermore, a ceramic printed wiring board in which a thick film resistor layer and a thick film conductor layer are formed on a ceramic substrate and then subjected to electroless plating or electroplating to form a thin film conductor pattern by a desired method is also referred to as "Tokyo Publication No. 5".
321109 Publication”, “Japanese Unexamined Patent Publication No. 33-202987
It is disclosed in "No. Publication" etc. In the above-mentioned ceramic printed wiring board, the method of performing electroless plating on the ceramic substrate is to use P containing halogen ions in advance.
A method of immersing the substrate in an acidic palladium colloid solution of H1 to H3 and activating it, or a method of sensitizing it with an aqueous tin chloride solution and then activating it with an aqueous palladium chloride solution are used.

(Problem to be solved by the invention)
3-202987, a thick film resistor layer and a thick film conductor layer interposed between the thick film resistor layer and the plated conductor are formed on a ceramic substrate, and both layers are protected from the plating solution. If a protective layer is applied to both layers and then activated using an acidic solution when performing electroless plating, the glassy component in the previously formed thick film conductor layer is eroded and the thick film conductor layer is There is a problem in that the adhesion strength between the substrate and the substrate is significantly reduced.

(Means for Solving the Problems) When forming a conductor pattern by plating on a ceramic substrate on which at least a thick film resistor layer is formed, the present invention provides at least an alkaline aqueous solution as a pretreatment for electroless plating. A method for manufacturing a ceramic printed wiring board characterized in that the manufacturing method of the ceramic printed wiring board is characterized in that the manufacturing method of the ceramic printed wiring board is characterized by processing in I found out that there is a way. That is, in manufacturing a ceramic printed wiring board in which at least a thick film resistor layer and a conductor pattern formed by plating are provided on a ceramic substrate, the ceramic substrate is treated with a palladium compound as a pretreatment for electroless plating. This is a method for manufacturing a ceramic printed wiring board, characterized in that it is treated with an alkaline aqueous solution containing: The ceramic substrate used in the present invention is
Holes are drilled as necessary, and either oxide or non-oxide ceramic substrates may be used. Oxide-based ceramic substrates are made of alumina, glass-based materials are made of aluminum nitride, silicon carbide, etc. preferable.

Further, in the present invention, the ceramic substrate may be used as it is, but preferably it is subjected to a physical or chemical surface roughening treatment in advance. An example of physical roughening is a method in which powder such as alumina is sprayed onto the substrate surface, and an example of chemical roughening is a method using a known chemical solution such as acid or alkali.

Although the thick film resistor layer formed on the substrate can be connected by directly forming a conductor pattern on the thick film resistor layer by plating, it is preferable to connect the thick film resistor layer to the conductor by plating. It is better to connect the patterns by interposing a thick film conductor layer.

Further, in the present invention, in order to protect the thick film resistor layer from the environment, plating solution, etc., it is preferable to form an insulator layer on the thick film resistor layer to form a protective layer. The insulator layer may be made of resin or glass yarn, but it is more preferable that it has chemical resistance. Further, in order to form a conductor pattern, as a pretreatment for electroless plating, the substrate is immersed in an alkaline aqueous solution containing a palladium compound and activated.

As the palladium compound, for example, Pdel□・2
Examples include aminohebiridine complexes and PdC1□-branched alkylamine complexes. In the present invention, preferably, before activating the substrate, an ethoxylated nonionic compound and a nitrogen-containing compound, or an ethoxylated nonionic compound and a
．． It is preferable to contact an adsorption promoter containing a halogen compound of 5M or more.The adsorption promoter may contain an ethoxylated nonionic compound, a nitrogen-containing compound, and a halogen compound of 0.5M or more.

A specific example of the ethoxylated nonionic compound is polyoxyethylene alkylphenyl ether, and a specific example of the nitrogen-containing compound is ethanolamine.

Electroless plating in the present invention refers to copper, nickel, gold,
Refers to electroless plating of silver, white metals, and their compounds. Further, it is also possible to form a conductor pattern by using electroplating in combination after electroless plating, but in this case, electroplating refers to electroplating of copper, nickel, gold, etc. using the electroless plating as a lower layer. Methods for forming the conductive pattern include a semi-additive method, a full additive method, and a subtract method, and any of them can be used.

The present invention has been made possible because the electroless plating pretreatment liquid of the present invention is alkaline compared to conventional acidic pretreatment liquids, and the glass component in the thick film conductor layer or the thick film conductor portion and the alumina substrate This is thought to be due to the fact that the reaction layer (interface layer) formed between the substrate and the like can be activated without being eroded.

(Example) <Example-1> 5-6 - Containing 96% alumina, length 50.8 cm, width 50.81
3 N111 white ceramic substrates with a thickness of 0.635 mm
The substrate surface was chemically roughened by immersing it in molten caustic soda maintained at 40°C for 10 minutes.

Next, a thick film conductor firing paste that does not contain glass components (fritless type) is applied to the desired location by screen printing, dried at 150°C for 10 minutes, and air fired at 900°C for 10 minutes (total 30 minutes). A membrane conductor terminal layer was formed. The spacing between the thick film conductor terminal layers is lll11 and h0
Next, thick film resistor firing paste (R931ONr Shoei Kagaku Kogyo 1
@J) Applied by t-screen printing, 150°CI
Dry for 0 minutes and dry at 850℃ for 10 minutes (total 35 minutes)
Air fired. Furthermore, in order to protect the thick film resistor layer, thick film insulator firing paste (#
5238r Shoei Kagaku Kogyo ■'') was air fired.

The shape of the thick film resistor layer after firing has a width of 1. OLl1m1 has a length of 1.5 mm and a thickness of 10 μm. The shape of the thick film insulator layer after firing is 1.2 m, 1.7 m long, and 10 m thick.
It is μm.

After forming the thick film conductor terminal layer, thick film resistor layer, thick film insulator layer, and thick film insulator layer, plated conductor circuits are formed on the alumina substrate using a semi-additive method so as to partially overlap with the thick film conductor terminal layer. formed a pattern.

Specifically, in order to promote adsorption of the catalyst, the substrate is coated with
Cleaner/Conditioner 902 "Nippon Schering e! After 5 minutes of immersion in IJ aqueous solution and rinsing with water, 30 seconds of immersion in Predip B "Nippon Schaging 011" aqueous solution, followed by an alkaline aqueous solution containing at least a palladium compound (Actipetar Neo Gant). 834 "Nippon Fehring 9-suke)" for 6 minutes, and after activation, it was washed with water. After that, an aqueous solution containing a reducing agent (Reducer WAr
After being treated in Nippon Schering fl Suke J), it was immediately immersed in an electroless copper plating solution (Print Gant MLr Nippon Schering ■) at 60°C for 20 minutes to obtain an electroless copper plating film of 1.0 μm. Further, a negative plating resist was formed in a circuit pattern using a photosensitive dry film so as to partially overlap the thick film conductor terminal layer, and electrolytic copper plating was deposited to a thickness of 10 μm. After electrolytic copper plating, remove the resist and apply thin electroless copper plating on non-circuit areas to 0.1
It was removed with M H2SO410, 1M H2O2 etching solution.

<Example-2> After activating the alumina substrate after forming the thick-film conductor terminal layer, thick-film resistor layer, and thick-film insulator layer by the same method as shown in Example-1, the bath composition shown below was prepared. and conditions 10.
An electroless copper plating film of 0 μm was obtained.

Bath composition: Cu5(1+l5H20(0,OEtM),
■C1 (0 (0,50M), EDTA (0,12M),
Na0H (adjusted to pH 10.5), iron hexacyano (I
I) Potassium acid (10 mg/l) 2,2'-dipyridyl (10 mg/)) P E G #
1000 (500mg/II) Conditions: pH
12.5, bath temperature 70℃ Furthermore, a positive etching resist was formed into a circuit pattern using a photosensitive dry film, and 0.1M
Non-circuit portions were removed using an etching solution (SO4/0.1M) at 120°.

<Example 3> After activating the alumina substrate after forming the thick film conductor terminal layer, thick film resistor layer, and thick film insulator layer by the same method as shown in Example 1, electroless nickel plating ( An electroless nickel plating film of 1.0 μm was obtained using Top Chemialloy B-1 "Okuno Pharmaceutical Co., Ltd. IJ).Furthermore, a negative plating resist was applied to a thick film conductor terminal using a photosensitive dry film. A circuit pattern was formed so as to overlap with a part of the layer, and electrolytic copper plating was deposited to a thickness of 10 μm.After electrolytic copper plating,
Peel off the resist and apply thin electroless nickel plating to non-circuit areas with 0.1M H2SO4/O, IM H20.
It was removed with the etching solution □.

<Example 4> After forming the thick film conductor terminal layer, thick film resistor layer, and thick film insulator layer by the same method as shown in Example 1, the lumina substrate was heated to a pH of at least 7 to 14. Immersed for 6 minutes in an alkaline aqueous solution containing a palladium compound (Actipetar Neogant 834 "Nippon Shading a@"),
Washed with water. After that, an aqueous solution containing a reducing agent (Reducer W
After processing in Ar Nippon Schering [1@J], it was immediately immersed in an electroless copper plating solution (Print Gant MLr Nippon Schering (1! IJ) at 60°C for 20 minutes.
A μm thick electroless copper plating film was obtained. Furthermore, a negative plating resist was formed into a circuit pattern using a photosensitive dry film so as to partially overlap the thick film conductor terminal layer, and electrolytic copper plating was deposited to a thickness of 10 μm. After electrolytic copper plating, the resist was peeled off, and the thin electroless copper plating portion on the non-circuit portion was removed using a 0.1M, H2SO4/0.1M 120° etching solution.

<Example-5> By the same method as shown in Example-1, thick film conductor baking paste (D-4) containing glass frit was applied to a roughened substrate.
E! 89r Shoei Kagaku Kogyo Wholesale'') was applied by screen printing, dried at 150°C for 10 minutes, and then
Air baking was performed at °C for 10 minutes (35 minutes in total) to form a thick film conductor terminal layer. Thick film conductor terminal layer spacing is 111
It was set to 11. Next, thick film resistor firing paste) (R931ONr Shoei Kagaku Kogyo A1) was applied by screen printing so as to partially overlap each thick film conductor terminal layer, and
It was dried at 0°C for 10 minutes and air-baked at 850°C for 10 minutes (35 minutes in total).

Furthermore, in order to protect the thick film resistor layer, a thick film insulator firing paste (#5238r Shoei Kagaku Kogyo (11)) was applied by screen printing to cover the entire surface of the thick film resistor layer.
It was dried at 150°C for 10 minutes, and then air fired at 600°C for 10 minutes (35 minutes in total).

The current state of the thick film resistor layer after firing is width 1.0-m1 length 1.0-m.
It has a thickness of 5 mm and a thickness of 10 μm. The shape of the thick film insulator layer after firing is 1.2-m1 in width, 1.7W in length, and 10 μm in thickness.

After forming the thick film conductor terminal layer, thick film resistor layer, and thick film insulator layer, the alumina substrate was plated using a semi-additive method in the same manner as in Example 1 so that the thick film conductor terminal layer partially overlapped with the alumina substrate. A conductive circuit pattern was formed.

Comparative Example-1> After forming a thick-film conductor terminal layer, a thick-film resistor layer, and a thick-film insulator layer by the same method as shown in Example-1, electroless copper plating was performed using PdC1°/5nC1.゜Immerse in a mixed acidic aqueous solution (5alt type) at 40°C for 5 minutes,
After washing with water, activation was performed with an aqueous HBF4 solution, and after washing with water, electroless copper plating and a conductor pattern were formed in the same manner as shown in Example-1.

Comparative Example-2> After forming a thick-film conductor terminal layer, a thick-film resistor layer, and a thick-film insulator layer by the same method as shown in Example-1, electroless copper plating was performed using PdC1□/5nC12. Immersed in mixed acidic aqueous solution (MCI type) at 15°C for 15 minutes, washed with water, activated with HBF4 aqueous solution, washed with water,
Electroless copper plating and a conductor pattern were formed by the same method as shown in Example-1.

<Comparative Example-3> After forming a thick-film conductor terminal layer, a thick-film resistor layer, and a thick-film insulator layer by the same method as shown in Example-1, electroless plating was performed using a 5nC12 aqueous solution at 40°C. After soaking for 5 minutes to sensitize and washing with water, Pdel. After being immersed in an aqueous solution at 40°C for 5 minutes, activated, and washed with water, electroless copper plating was performed in the same manner as shown in Example-1, and after washing with water,
Electroless copper plating and a conductor pattern were formed by the same method as shown in Example-1.

<Comparative Example-4> After forming a thick-film conductor terminal layer, a thick-film resistor layer, and a thick-film insulator layer by the same method as shown in Example-5, a PdCl2/5nCI2 mixture was used for electroless copper plating. After immersing in an acidic aqueous solution (5alt tyl) e) at 40°C for 5 minutes, rinsing with water, activation with an aqueous HBF4 solution, and rinsing with water, electroless copper plating and , a conductor pattern was formed.

FIG. 1 schematically shows the patterns obtained in Examples 1 to 5 and Comparative Examples 1 to 4.

In addition, in FIG. 1, part (c) is only the thick film conductor layer portion on each side that was created through the same process as that on each side, apart from the pattern in each Example and Comparison 13-14- Example. This is the part for measuring adhesion strength. The adhesion strength was measured by measuring 90 degree beer strength using part (C).

Also, using part (b) shown in Figure 1,
Resistance change after 2000 heat cycles at 50°C (
ΔR%) was evaluated.

Table 1 shows the evaluation results for each side.

Table 1 (Effects of the invention) By implementing the present invention, it becomes possible to form a plated conductor pattern without corroding the thick film conductor terminal layer (thick film conductor layer), and the connection between the thick film resistor and the plated conductor becomes possible. Ceramic printed wiring boards with high reliability can be manufactured.

[Brief explanation of the drawing]

FIG. 1 shows patterns of examples and comparative examples of the present invention, where (a) is an overall view, and (b) is a partially enlarged view of a connection between a thick film resistor and a plated conductor. (c) shows the pattern used for evaluation of adhesion strength.

Claims (1)

[Claims] (1) When manufacturing a ceramic printed wiring board in which at least a thick film resistor layer and a conductor pattern formed by plating are provided on a ceramic substrate, the ceramic substrate is coated with an alkaline solution containing a palladium compound as a pretreatment for electroless plating. A method for manufacturing a ceramic printed wiring board, characterized by processing with an aqueous solution.