JPS61191098A - Ceramic multi-layer interconnection baord and manufacture thereof - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical field to which the invention pertains) The present invention relates to a ceramic multilayer wiring board and a method for manufacturing a ceramic multilayer wiring board.

(Prior Art) Conventional ceramic multilayer wiring boards (hereinafter referred to as wiring boards) have a main component of, for example, copper powder, which is a highly electrically conductive metal, and glass powder and an organic binder.

There is a dry thick film wiring board that is made by adding and mixing a solvent or the like to form a base, which is coated on a ceramic substrate such as alumina, and then baked to form conductor wiring.

(Problem to be Solved by the Invention) However, in the above wiring board, the conductor wiring is made of not only copper powder but also glass powder, etc., so the specific resistance is about 1.5 times that of copper alone. However, the disadvantage is that the electrical conductivity decreases.

On the other hand, metal-additive ceramic wiring board 1 in which copper is directly attached to ceramics by plating 1 For example, manufactured by Hitachi Chemical Co., Ltd., product name HMAC, the specific resistance of the conductor wiring is almost equal to that of copper alone, but it is difficult to make the wiring multi-layered. It is not possible to achieve high density.

An object of the present invention is to provide a wiring board that can be multilayered, has high electrical conductivity on only two surfaces, and can form conductor wiring with low resistance similar to that of a single metal, and a method for manufacturing the same. It is.

(Means for Solving the Problems) As a result of various studies on the above-mentioned drawbacks, the inventors of the present invention discovered that a conductor paste was fired inside the ceramic plate to expose a part of the internal conductor wiring on the surface of the ceramic plate. 9. Next, an anti-roughening film is formed on the exposed surface of the internal conductor wiring, and then the surface of the ceramic plate is roughened by etching, and then the anti-roughening film is removed.

By forming a metal film on the roughened surface of the ceramic plate and the exposed surface of the internal conductor wiring, and forming the conductor wiring by leaving only the necessary parts of the metal film, multilayering can be easily achieved, and only two surfaces can be formed. It was confirmed that conductive wiring with high electrical conductivity and low resistance similar to that of simple metals can be formed.

The present invention provides a wiring board and a ceramic, in which a part of internal conductor wiring obtained by firing a conductor base in a ceramic board is exposed on the surface of the ceramic board, and conductor wiring is formed on the exposed surface and the surface of the ceramic board. A process of exposing a part of the internal conductor wiring within the board to the surface of the ceramic board,
A process of forming an anti-roughening film on the exposed surface of the internal conductor wiring, a process of etching and roughening the surface of the ceramic plate, a process of removing the anti-roughening film formed on the exposed surface of the internal conductor wiring, and then a process of forming an anti-roughening film on the exposed surface of the internal conductor wiring. The present invention relates to a method for manufacturing a wiring board, which includes the steps of forming a metal coating on the exposed surface of the wiring and the roughened surface of a ceramic plate, and forming conductor wiring by leaving only necessary portions of the metal coating.

In the present invention, high melting point metal powders such as molybdenum, manganese, tungsten, etc. are used for the conductor base forming the internal conductor wiring, and a binder, a solvent, etc. are added to these high melting point metal powders and mixed uniformly to form the conductor. It is considered a paste.

The baking temperature of the conductor paste varies depending on the type of high-melting metal powder used, but it is usually baked at a temperature of about 1300 to 1600°C. The internal conductor wiring in the present invention also includes through holes and via holes.

In the present invention, in order to firmly adhere the metal coating to the surface of the ceramic plate, the surface of the ceramic plate is etched and roughened. It is preferable to heat and melt an alkali such as lithium hydroxide, and use this melt to etch and roughen the inorganic matter and glass in the ceramic plate. There is no particular restriction on the temperature during etching for 1 hour, etc. When etching a dead body.

It is necessary to form a roughening resistant film on the internal conductor wiring exposed on the surface of the ceramic plate, and if the roughening resistant film is not formed, there will be a drawback that the adhesive strength after the metal coating is formed will be weak. As the roughening-resistant film, a silver or nickel film is formed, and there are no particular restrictions on the film thickness and the method for forming the film.

Plating methods, printing methods, thermal spraying methods, etc. may be used, and there are no particular limitations.

After removing the anti-roughening film, sensitization treatment and activation treatment are performed as necessary. For example, when forming a metal film on the exposed surface of internal conductor wiring and the surface of a ceramic plate by plating, the upper part is coated with a sensitizing solution such as a mixed solution of S n C12.2HxO and HO2.

PdC1z ・2 HsO(!: HC1!, Pd
Cl! z ・2 If the metal film is sensitized and activated by immersing it in an activation solution such as a mixed solution of H2O, HC, and glacial acetic acid, a metal film will firmly adhere to the exposed surface of the internal conductor wiring and the surface of the ceramic plate. can be done.

The metal coating can be formed by a method such as a plating method or a vapor deposition method, and there is no particular limitation, but when forming a thick film, it is preferable to use a plating method. When plating is used, it is preferable to perform electroless plating on the base and electrolytic plating on the upper surface, since this improves the adhesion of the plating and allows the plating to be completed in a short time. Copper, nickel, etc. are used as the electroless plating metal, and the thickness of the metal film formed by electroless plating is preferably in the range of 0.5 to 3 μm in relation to pinholes and adhesive strength. The metal coating formed on the upper surface of the base metal is preferably electrolytically plated with copper due to its electrical conductivity. There are no particular restrictions on the type of copper plating bath.
'The thickness of the steel plating is also not particularly limited, but it is preferably in the range of 1 to 200 μm in terms of resistance, adhesive strength, and workability.

The conductor wiring formed on the surface of the ceramic plate may be formed by leaving only the necessary parts of the metal coating and etching and removing unnecessary parts, or by attaching the metal coating only to the parts that will become the conductor wiring. There are no particular limitations.

(Example) The present invention will be described in detail below with reference to the drawings.

Example 1 93 parts by weight of alumina having an average particle size of 2 μm, 4.2 parts by weight of talc and 18 parts by weight of clay as sintering aids.

A slip obtained by adding 7 parts by weight of polyvinyl butyral and 3 parts by weight of dioctyl phthalate as a plasticizer and uniformly mixing the mixture was subjected to a doctor blade method to obtain a ceramic green sheet having a thickness of 0.6 mm. This ceramic green sheet was cut into a size of 60 x 60 mm, and as shown in FIG. Then, as shown in Figure 1 (bl), tungsten paste (manufactured by Asahi Chemical, 3TW-12Qo) 3
was filled into the through hole 2 and screen printed on the ceramic green sheet 1 to a thickness of 30 μm.

Further, on the surface of the insulating paste 4, 15 parts by weight of butylcarpitol acetate was added as a solvent to 100 parts by weight of the slip before being made into a lamic green sheet.
As shown in FIG. 1(C), via holes 14 with a diameter of 0.2 mm are formed with a pitch width of 10 mm and a pitch of 40 μm is formed.
It was screen printed to a thickness of m. Next via hole 14
was filled with the tungsten paste 3 used above and baked at a temperature of 1600°C for 1 hour in a slightly reducing atmosphere to form the first paste.
As shown in (d) of the figure, a part of the internal conductor wiring 7 formed by firing the tungsten paste 3 is exposed on the surface with the ceramic 6 at the center, and the other internal conductor wiring 7 is fired inside the ceramic d. A ceramic plate was obtained by forming. Thereafter, as shown in FIG. 1(e), boron nickel (trade name 5B-55, manufactured by Nippon Kanigen) is deposited to a thickness of 4 μm on the exposed surface of the internal conductor wiring 7 by electroless plating to prevent roughness. After forming a chemical film 5, the surface of the ceramic 6' was roughened by immersing it in a thorium hydroxide melt heated to 350° C. for 20 minutes, and then taken out and washed with running water to obtain a solution with a concentration of 2.
Ultrasonic cleaning for 3 minutes in 0 wt. sulfuric acid solution.

In addition, nickel plating remover (manufactured by Okuno Pharmaceutical Co., Ltd., product name:
The anti-roughening film 5 formed on the exposed surface of the internal conductor wiring was removed by immersion in a tube lip AZ). Next, a sensitizing solution (manufactured by Okuno Pharmaceutical, trade name TMP Sensitizer) and an activating solution (
After sensitizing and activating the product by dipping it in K (manufactured by Okuno Pharmaceutical Co., Ltd., trade name: TMP Actepator), it was first sensitized and activated by electroless plating in a silin nickel plating bath (manufactured by Okuno Pharmaceutical Co., Ltd., trade name Top Colon 50). As shown in (f) of the figure, a phosphorous nickel coating 8 with a thickness of 2 μm was deposited on the entire surface.

Furthermore, a copper coating 9 of 30 μm in thickness was deposited on the surface of the tube by electrolytic plating as shown in FIG. 1(g).

After that, as shown in FIG. 1(h), etching resist (manufactured by Taiyo Ink, trade name M-808) 1
0 was screen printed, and after drying, the copper was etched using a ferric chloride solution as a steel etching solution, and then a nickel etching solution (manufactured by Okuno Pharmaceutical Co., Ltd., trade name Toplip A) was used.
After etching the phosphorous nickel using phosphorus nickel (Z), the etching resist 10 is peeled off by cleaning with trichlene, and the etching resist 10 is removed as shown in FIG.
A wiring board shown in i) was obtained.

Example 2 After immersing the ceramic plate obtained in Example 1 in activating solution NQ3 manufactured by Nippon Kanigen to activate the exposed surface of the internal conductor wiring, the ceramic plate obtained in Example 1 was immersed in boron nickel (manufactured by Okuno Pharmaceutical Co., Ltd.) to activate the exposed surface of the internal conductor wiring.

Knife Lad (trade name: 740) was applied to a thickness of 4 μm by electroless nickel plating to form a roughening-resistant film 5 as shown in FIG. 2(a). After sandwiching the ceramic plate on which the anti-roughening film 5 has been formed between 200 mesh stainless steel mesh 11 plated with nickel, a 30% by weight aqueous solution of sodium hydroxide is poured from both sides of the stainless steel mesh 11. .1 cc/
cm2 was added dropwise, and the mixture was further placed in a firing furnace heated to 350°C for 1 hour to roughen the surface of the ceramic 6'.

Next, it was taken out of the firing furnace and cooled down to room temperature by natural cooling, then washed with running water, and the stainless steel mesh was removed from the ceramic wiring board. After that, it was immersed in a nickel plating remover (manufactured by Nippon Kanigen, trade name: -200). Then, the anti-roughening film 5 formed on the exposed surface of the internal conductor wiring is removed.

Furthermore, the exposed surface of the internal conductor wiring was activated by immersing it in activating solution 3 manufactured by Nippon Kanigen Co., Ltd., and then electroless plating was performed on the exposed surface of the internal conductor wiring in a silin nickel plating bath (manufactured by Nippon Kanigen Co., Ltd., trade name 8680). A second layer is placed on the exposed surface of the conductor wiring.
As shown in (bl) of the figure, a phosphorus-nickel coating 8 was deposited to a thickness of 3 μm, and then subjected to sensitization treatment and activation treatment in the same manner as in Example 1, followed by electroless plating. As shown in (C), a cuprous coating (manufactured by Hitachi Chemical, trade name: CUST-201 using steel plating solution) 12 was applied to the entire surface.
It was deposited to a thickness of μnl. Next, the same etching resist 10 as in Example 1 is screen-printed on the opposite pattern portion of the desired pattern as shown in FIG. A cupric coating 13 was deposited to a thickness of 20 μm as shown in FIG.
A wiring board shown in f) was obtained.

Note that when the specific resistance of the wiring boards obtained in Examples 1 and 2 was measured, they showed high electrical conductivity of about 1.7 .mu..OMEGA.-B. On the other hand, a conventional dry thick film wiring board in which a paste made by adding glass powder to copper powder is applied to a ceramic substrate and then baked to form conductor wiring has a specific resistance of approximately 2.5 μm.
It was Cm.

(Effects of the Invention) According to the present invention, it is possible to obtain a wiring board that can be easily multilayered, has high electrical conductivity on only one surface, and forms conductive wiring with low resistance like that of a single metal.

[Brief explanation of the drawing]

Figure 10(a), (b), (c), (di, (
e), (f), (g), (h) and m are cross-sectional views showing the state of manufacturing work of a wiring board according to an embodiment of the present invention, and Fig. 2 o(a), (b), (c) ), (di, (e
) and (f) are cross-sectional views showing the state of manufacturing a wiring board according to another embodiment of the present invention. Explanation of symbols l...Ceramic green sheet 2...Through hole 3...Tungsten paste 4...Insulating paste 5...Roughing resistant film 6...Ceramics 7...Inner conductor wiring 8...・Phosphorous nickel coating 9...Copper coating 10...Enoting resist I-11...Stainless steel mesh 12...Copper coating
13...Copper coating 14...Via hole 1st concave

Claims (1)

[Claims] 1. A part of the internal conductor wiring obtained by firing a conductive paste inside a ceramic plate is exposed on the surface of the ceramic plate, and the conductor wiring is formed on this exposed surface and the surface of the ceramic plate. Ceramic multilayer wiring board. 2. Step of exposing a part of the internal conductor wiring in the ceramic board to the surface of the ceramic board. Step of forming an anti-roughening film on the exposed surface of the internal conductor wiring. Roughening the surface of the ceramic board by etching. step, removing the anti-roughening film formed on the exposed surface of the internal conductor wiring, then forming a metal coating on the exposed surface of the internal conductor wiring and the roughened ceramic plate surface, and removing only the necessary portions of the metal coating. 1. A method for manufacturing a ceramic multilayer wiring board, characterized in that a step of forming conductor wiring is performed by leaving a remaining portion behind.