JPS62296599A - Composite ceramic multilayer interconnection board and manufacture of the same - 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 (Field of Industrial Application) The present invention relates to a composite ceramic multilayer wiring board used for electronic circuit components such as hybrid integrated circuits, and a method for manufacturing the same.

(Prior Art) Ceramic wiring boards include ceramic wiring boards manufactured by the green method and ceramic wiring boards manufactured by the thick film method. In recent years, ceramic wiring boards have become more densely packed and more complex, so composite ceramic multilayer wiring boards are produced by forming conductor layers, resistor layers, etc. using the thick film method on ceramic wiring boards manufactured using the green method. Some parts have been put into practical use.

As shown in FIG. 3, a conventional composite ceramic multilayer wiring board has an internal conductor layer 2 mainly composed of powder of a high melting point metal such as Mo or W formed in an alumina ceramic 1. The part is pulled out to the surface through the through hole 5,
A Ni layer 8 is formed on the exposed surface of the internal conductor layer 2 exposed on the through hole 5 by a method such as plating, and then the upper surface A
A material having a precious gold maple layer 6 formed thereon, such as U, is generally known.

(Problems to be Solved by the Invention) When manufacturing electronic circuit components using the composite ceramic multilayer wiring board shown in FIG.
Thick film circuits such as an outer conductor layer mainly composed of powder and a resistor layer mainly composed of RuO2 powder are formed, but since these thick film circuits are usually sintered in the atmosphere, the inner conductor layer and internal It is necessary to prevent the metal layer formed on the exposed surface of the conductor layer from oxidizing. However, when a composite ceramic wiring board having the above structure is used and fired at a temperature of 800 to 950 DEG C., there is a drawback that the underlying internal conductor layer and metal layer are oxidized.

As a countermeasure for this, Ag/P for low temperature firing (below 650℃)
It is possible to form thick film circuits such as an external conductor layer mainly composed of d powder or a resistor layer mainly composed of RuO2 powder, or to form thick film circuits such as a curing type conductor layer or a carbon-based resistor layer. However, compared to thick film circuits fired at high temperatures, these circuits have a disadvantage in that they have a large TCR (resistance variation rate) and are inferior in reliability.

(Means for Solving the Problems) An object of the present invention is to provide a composite ceramic multilayer wiring board and a method for manufacturing the same, which are free from the above-mentioned drawbacks.

The inventors of the present invention investigated the above-mentioned drawbacks repeatedly, and found that by exposing a part of the surface to the surface using the green method, alumina ceramics containing ~(0, W, etc.) melting point metal powder as the main component. An internal conductor layer is formed, and then an Ag/Pd layer is formed on the internal conductor layer -F exposed to the surface through the through hole by a method such as screen printing or transfer.
A glass paste was chipped onto the surface of the alumina ceramics, leaving approximately the center of the surface of the d layer, and fired in a medium τF atmosphere to form a glass layer with via holes. It was confirmed that the underlying internal conductor layer and Ag/Pd layer were not oxidized even if

The present invention relates to a composite ceramic multilayer wiring board consisting of a glass layer formed by providing a via hole on the surface of alumina ceramics and an Ag/Pd layer with a part exposed on the surface, and a part exposed on the surface using the green method. Then, an Ag/Pd layer is formed on the exposed surface of the internal conductor layer, and a glass paste is applied to the surface of the alumina ceramic, leaving approximately the center of the surface of the Ag/Pd layer. The present invention relates to a method for manufacturing a composite ceramic multilayer self-wire plate, which is coated and fired in a neutral atmosphere to form a glass layer having via holes.

In the present invention, the material forming the internal conductor layer is M
High melting point metals such as O, Mo/Mn, and W are used.

The Ag/Pd layer is formed by transfer.

There are no particular limitations on the method of applying Ag/Pd paste and baking it by heat treatment, but in the present invention, A
Preferably, the Ag/Pd paste is formed by applying a Ag/Pd paste, heat-treating it in a reducing or neutral atmosphere, and baking the Ag/Pd paste.

There is no particular restriction on the thickness of the Ag/Pd layer.

A thickness of 5 to 20 μm is preferable in terms of ease of workability since the Ag/Pd layer has no pinholes.

The glass used to form the glass layer is amorphous glass,
A crystallized glass that can be sintered in a neutral atmosphere is used. Note that if a glass having a softening point of 650° C. to below the melting point of the Ag/Pd layer is used.

This is advantageous because glass does not diffuse into alumina ceramics when forming thick film circuits. Further, it is preferable to use glass which has a higher free energy of oxide formation than the high melting point metal because the high melting point metal will not be oxidized even if the glass diffuses into the high melting point metal. Furthermore, crystallized glass is heat treated (800-850℃)
It is preferable to use glass that does not cause microcracks.

To bake the glass paste, it must be baked in a neutral atmosphere such as N2HAr, and if it is baked in a non-oxidizing atmosphere, the internal conductor layer etc. will be oxidized to 1~1. Furthermore, when fired in a reducing atmosphere, the organic binder in the glass paste remains and hinders the sintering of the glass.

The composite ceramic multilayer wiring board according to the present invention includes Ag/P d + Ag/P t containing glass on the via hole and the glass layer around the via hole as necessary.
-Pt+ Outer conductor layer mainly composed of Au etc.+RuO
A thick film circuit such as a resistor layer containing □ as a main component may be formed.

(Example) The present invention will be explained below with reference to Examples.

Example 1 Two alumina ceramic green sheets (alumina purity 96% by weight) (hereinafter referred to as green sheets) having a thickness of 0.8 ann were cut into a size of 50×50a++n.

One of these has a diameter of 0.6. 2. Next, fill the through hole with W paste (manufactured by Asahi Kagaku Co., Ltd., product name 3TW-1200), print the same W paste as above on one surface, and after drying, paste on the other side. Place the above green sheet on top of one green sheet with the side with the W paste printed on it facing down.
The green sheet was heated and pressed under the conditions of 00°C and 61 (g/Ca1l), and then held at a temperature of 1600°C for 1 hour in a weakly reducing ()-Tz) atmosphere to sinter the green sheet and W.
The paste was sintered to obtain a ceramic wiring board in which internal conductor layer 2 was formed in alumina ceramics 1 with a portion exposed on the surface as shown in FIG.

Next, 80% by weight of Ag powder with an average particle size of 0.3 μm and 20% by weight of Pd powder were mixed in the center of the protruding surface of the internal conductor layer 2, and 100 parts by weight of this mixture was mixed with an acrylic binder. (manufactured by DuPont, trade name ◆5200) and 20 parts by weight of α-terpineol as an organic solvent were added, and the Ag/Pd paste obtained by kneading with three rolls was heated to a diameter of 0.4 mm. Printed to a thickness of 10 μm and dried at 750°C in a reducing atmosphere.
The Ag/Pd layer 3 was formed by heat treatment at a temperature of 10 minutes.

After this, 5ins 50% by weight t Ba024% by weight.

Glass having a softening point of 860°C and containing 6% A/gOs and Ca020 was ground to an average particle size of 3 μm,
To 100 parts by weight of this pulverized glass powder, 2 parts of acrylic binder (manufactured by DuPont, trade name: 5200)
10 parts by weight of butylcarpitol acetate (including parts by weight and organic solvent) were added, and the mixture was kneaded with three rolls to form a paste. Next, the glass paste was mixed with Ag/P
Leave a diameter of 0.2 mm in the center on the d layer 3, and print over the surface K of the alumina ceramic 1 in a ring shape with a width of 0.4 am, and a thickness of 40 μm after drying. After drying, the composite ceramic multilayer wiring board was heat-treated at a temperature of 900° C. for 20 minutes in an N2 atmosphere to obtain a composite ceramic multilayer wiring board in which a glass layer 4 and via holes 7 were formed. Note that in FIGS. 1 and 2, 5 is a through hole.

Example 2 A 10 μm thick Ag/Pd layer was formed on the internally exposed surface of the ceramic wiring board obtained in Example 1 in the same manner as in Example 1. After this, 5lOa54 weight section.

AI! *os 13wt'l=, Zn07wt%,
A glass with a softening point of 820° C. consisting of Ca025 weight percent and MgO 1 weight percent was ground to an average particle size of 3 μm, and 2 parts of an acrylic binder (manufactured by DuPont, trade name Na 5200) was added to 100 parts by weight of this ground glass powder. 1 part by weight and 1 part by weight of butylcarpitol acetate as an organic solvent.
Add 0 parts by weight and knead with 3 rolls to make paste 1
~is. Next, apply the glass paste from the previous step in the same manner as in Example 1.

The central part on the Ag/Pd layer has a diameter of 0.3 mm remaining. Width is 0.6rrrm across the surface of alumina ceramics
The composite ceramic multilayer was printed in a ring shape with a thickness of 50 μm after drying, and after drying was heat-treated at a temperature of 850°C for 10 minutes in a Nm atmosphere to form a glass layer and a via hole. I got a wiring board.

Example 3 A 20 μm thick Ag/Pd layer was formed on the internally exposed surface of the ceramic wiring board obtained in Example 1 in the same manner as in Example 1. After that, a Ca-based multilayer glass paste (manufactured by Nichiryo Ferro Denshi Co., Ltd., trade name 1005 RCu) was applied in the same manner as in Example 1, in the same shape as in Example 1, and with a thickness of 30 μm after drying. Print to the desired thickness and dry gNmW
A composite ceramic multilayer wiring board in which a glass layer and a via hole were formed was obtained by heat treatment at a temperature of 850 DEG C. for 1 hour in N air.

Comparative Example 1 A Ni plating layer with a thickness of 4 μm was formed on the exposed surface of the internal conductor layer of the ceramic wiring board obtained in Example 1 using the same method and using the same plating solution as in Example 1. Then, electroless Au plating (manufactured by Nippon Engelhard Co., Ltd., trade name: ATOMEX-PC) was performed on the top surface, followed by washing with water and drying to form a 1 μm thick Au plating layer to obtain a composite ceramic multilayer wiring board. Ta.

Next, high temperature sintered glass was added to the inside of the via hole and on the glass layer around the via hole of the composite ceramic multilayer wiring board obtained in each example, and on the Au plating layer of the composite ceramic multilayer wiring board obtained in Comparative Example 1. Ag/Pd paste (manufactured by Nichika Matsusei Co., Ltd., trade name ÷4846) was printed, and after drying, it was heat-treated in the air at a temperature of 850°C for 10 minutes to form glass-containing Ag.
/Pd paste was baked to form a glass-containing Ag/Pd layer. Next, the connection resistance between the glass-containing Ag/Pd layer and the internal conductor layer and the presence or absence of oxidation of the internal conductor layer were observed. As a result, the composite ceramic multilayer wiring boards obtained in each example had a connection resistance of 1 mΩ or less with a small fluctuation rate, and no oxidation of the internal conductor layer was observed. On the other hand, comparative example 1
In the composite ceramic multilayer wiring board obtained in 1, gas conduction could not be obtained and the internal conductor layer was oxidized. Similar effects were also obtained by forming a glass-containing Pt layer, a glass-containing Au layer, or a glass-containing Ag/Pt layer instead of the glass-containing Ag/Pd layer.

(Effects of the Invention) In the composite ceramic multilayer wiring board according to the present invention, the internal conductor layer does not oxidize and has high reliability in terms of electrical characteristics.

It is extremely suitable industrially.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional side view of a ceramic multilayer wiring board to be mated according to an embodiment of the present invention, and FIG. 2 is a cross-sectional side view of a ceramic wiring board used in a composite ceramic multilayer wiring board according to an embodiment of the present invention. FIG. 3 is a cross-sectional side view of a conventional composite ceramic multilayer wiring board. Explanation of symbols 1...Alumina ceramics 2...Inner conductor layer 3
...Ag/Pd layer 4...Glass layer 5...Through hole 6...Precious metal layer 7...Via hole 8...Ni layer filter 2 Fig. 32

Claims (1)

[Claims] 1. An internal conductor layer built into alumina ceramics with a part exposed on the surface, an Ag/Pd layer formed on the exposed surface of the internal conductor layer, and an Ag/Pd layer formed on the surface of the alumina ceramics. A composite ceramic multilayer wiring board consisting of a glass layer formed by providing via holes on a Pd layer. 2. Form an internal conductor layer in alumina ceramics by exposing a part to the surface using the green method, then form an Ag/Pd layer on the exposed surface of the internal conductor layer, and then form an Ag/Pd layer on the exposed surface of the internal conductor layer.
A method for producing a composite ceramic multilayer wiring board characterized by applying glass paste to the surface of alumina ceramics leaving approximately the center of the surface of the layer and firing in a neutral atmosphere to form a glass layer having via holes. .