JPH04331781A - Ceramics composite material - Google Patents

Abstract

PURPOSE:To obtain a polyfunctional composite plate useful as radiating plate, etc., by bonding metallic plates, through which an electrically conductive material is partially passed, to the surface and back of a ceramics plate. CONSTITUTION:A through hole 4 is bored through a ceramics plate 1 such a AlN having 0.2-1.0m/m plate thickness, an active metal powder paste 5 is subjected to screen printing in desired thickness on both sides of the plate 1 and simultaneously the interior of the hole 4 is coated with the paste 5. Then copper plates 2 and 3 having different thickness are stuck to the surface and the back of the plate 1 to give a bonded material, which is introduced to a furnace, heated in an atmosphere under 10<-2>Torr degree of vacuum at 700-950 deg.C for 3-60 minutes and cooled to produce a ceramics composite material.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a ceramic composite, and more particularly to a composite plate consisting of a ceramic plate and a metal plate.

[Technical background]

Conventionally, various composite plates in which metal plates are bonded to the front and back surfaces of a ceramic plate have been proposed and are widely used mainly in electronic parts, mechanical parts, and the like.

However, for example, in electronic parts, these composite plates are used only by etching the front metal plate as an electronic circuit, and by using the back metal plate as a heat dissipation plate for the heat generated from the electronic circuit and electronic materials. .

Therefore, the present inventors have conducted extensive research and have arrived at the present invention.

[Problem that the invention seeks to solve]

The present invention aims to solve the above-mentioned problems of the prior art, and aims to provide a novel ceramic composite that has been completely unknown heretofore.

[Means for solving problems]

The present invention was made in order to solve the above-mentioned problems, and in a composite body formed by bonding metal plates to the front and back surfaces of a ceramic plate, the two metal plates are partially made of a conductive material. The present invention provides a ceramic composite characterized by being electrically conductive.

Therefore, according to the present invention, a multifunctional composite plate can be obtained in which the metal plates bonded to the front and back surfaces of the ceramic plate function as an electronic circuit and a heat sink. below,
The constituent factors of the present invention will be explained in more detail.

"Ceramics" as used in the present invention is not particularly limited, but includes oxide ceramics and non-oxide ceramics. Oxide ceramics include, for example, alumina (Al2
O3), magnesia (MgO) and ziriconia (ZrO)
2), among others, alumina is preferred. Examples of non-oxide ceramics include aluminum nitride (AlN)
, silicon carbide (SiC), and silicon nitride (Si3N4), among which aluminum nitride and silicon carbide are preferred, and aluminum nitride is particularly preferred.

In addition, the thickness of the ceramic plate is not particularly regulated, and may be any thickness, but generally 0.2 to 1.0
m/m, preferably 0.3 to 0.8 m/m.

The "metal" used in the present invention is not particularly limited, but copper (C
u), nickel (Ni), chromium (Cr) cobalt,
Examples include aluminum (Al) and alloys thereof, among which copper (Cu) and nickel (Ni) are preferred;
In particular, copper and alloys mainly composed of copper metal are preferred. As the copper metal, for example, copper metal specified by JIS H3100 is preferable, and oxygen-free copper (alloy number C1020) is especially preferable.

Among the metal plates used in the present invention, metal plates used as conventional electronic circuit boards (hereinafter referred to as "surface metal plates (X)") are etched in a post-process. The thickness is the metal plate bonded to the back side via the ceramic substrate (hereinafter this metal plate will be referred to as the "back metal plate (Y)").
There is no particular restriction on the thickness of the plate (
m) is preferably 0.1 to 0.5 m/m, more preferably 0.15 to 0.3 m/m, and Y is generally 0.
05-0.6m/m, preferably 0.1-0.5m/m
, more preferably 0.15 to 0.3 m/m. The relationship between the plate thicknesses of X and Y is 0.1X≦Y≦1.0X), preferably 0.2X≦Y≦1.0X, more preferably 0.1X≦Y≦1.0X).
It is desirable that 3X≦Y≦1.0X.

There are no particular limitations on the method of joining the ceramic plate and the metal plate used in the present invention, but for example, the ceramic plate and the metal plate are heated in an inert gas atmosphere such as nitrogen gas or in a vacuum atmosphere to bond the metal plate and the ceramic plate. Direct joining method (direct joining method). In addition, a brazing material made of a mixture or alloy of active metals such as Ti and Zr and metals such as Ag, Cu, Ni, and Sn, which form low melting point alloys, is interposed between the ceramic plate and the metal plate to create an inert gas atmosphere or vacuum atmosphere. There are two methods: a method in which the metallized layer is bonded under heat (active metal method), and a method in which a metallized layer is formed on the ceramic plate and the ceramic with this metallized layer and the metal plate are bonded with a metal solder (metalized method). The active metal method and the active metal method are preferred, with the active metal method being particularly preferred.

Specifically, the direct bonding method used in the present invention refers to, for example, placing a metal plate on a ceramic plate, placing it in a heating furnace, and reducing the oxygen concentration to 20% to prevent excessive oxidation of the metal body.
This is a method of heating at a maximum heating temperature of 1060° C. to 1083° C. for 5 seconds to 15 minutes in an inert atmosphere or a vacuum atmosphere adjusted to a ppm or less, and then cooling to obtain a bonded body. In addition, the active metal method refers to, for example, applying active gold brazing material in the form of foil or powder to the bonding surface between a ceramic plate and a metal plate, or even kneading the powder with a binder to make a paste, screen printing this, and then bonding. The body is placed in a heating furnace and heated at a maximum heating temperature of 700 to 950°C for 3 to 60 minutes in an inert atmosphere or an atmosphere with a degree of vacuum of -10-2 Torr or less, and then cooled to obtain a bonded body. It's a method.

There are no particular restrictions on the active metal brazing filler metal, but silver (Ag), copper (Cu), which can be joined by heating at a relatively low temperature,
), mixtures of titanium (Ti) or titanium hydride (TiH), silver (Ag), copper (Cu), nickel (Ni), mixtures of titanium (Ti) or titanium hydride (TiH), silver (Ag) , copper (Cu), tin (Sn), titanium or titanium hydride (TiH) mixtures, silver (Ag), nickel (
Ni), titanium or titanium hydride mixture systems, and silver (A
g), a mixture system of copper (Cu), zirconia (Zr) or zirconia hydride, among which a mixture system of silver, copper, titanium or titanium hydride, a mixture system of silver, copper, nickel, titanium or titanium hydride can be mentioned. Mixture systems are preferred.

In addition, the method for establishing electrical continuity between X and Y is not particularly limited, but for example, a through hole that is preset in the ceramic plate when joining the ceramic plate and the metal plate, or a through hole in the ceramic plate, There are methods such as interposing the brazing filler metal in a part of the end portion and then heating it, or directly connecting it with a conductive wire, and the former is preferred in the present invention.

The composite plate of a ceramic plate and a metal plate obtained in this way is a multifunctional composite plate that functions as an electronic circuit and a heat sink, respectively. board, and its contribution to the industry is extremely large.

The present invention will be explained in more detail below with reference to Examples, but it goes without saying that the present invention should not be limited only to the Examples.

Example A (Preparation of composite) Example 1 2 defined by JIS H3100, metal number C1020
Types of oxygen-free copper plates (plate thickness 0.3m/m and 0.25m/m
, dimensions 45 x 30 m/m) were prepared.

An alumina (Al2O3) plate (thickness: 0.635 m/m, dimensions: 45 x 30 m/m) was prepared as a ceramic plate.

Five through holes (hole diameter 0.3 m/mφ) were previously installed in this alumina plate. Active metal powder paste (Ag-Cu-Ti: 71.5-27.5-1) was applied to both sides of the alumina plate.
) was screen printed to a thickness of 30 μm, and at the same time, the inner wall of the through hole was also coated with the metal powder paste.

Next, the two types of copper plates having different thicknesses were respectively placed on the front and back surfaces of the alumina plate, and after pressurizing at 1 kg/cm2, they were heated at 850° C. for 10 minutes under a vacuum condition of 10 −5 Torr. Thereafter, it was cooled to obtain a composite. Next, the surface of the copper plate (plate thickness 0.3 m/m) on the surface of the composite was polished, a patterning resist was printed, and after heat curing, immersion etching was performed in a cupric chloride aqueous solution, and the resist was peeled off with a caustic soda aqueous solution. and obtain a patterned composite,
Further, the copper plate portion of this composite was eroded in an aqueous ammonium persulfate solution and then washed with water to obtain a patterned composite.

The ratio of the area after etching to the area before etching of the copper plate obtained here and used for the surface of the composite was 0.7.

Example 2 In Example 1, a groove was made in the surface of the alumina plate so that it could be divided into two parts, the number of through holes was set to 1, and the above groove passed through the center. A patterned composite was obtained.

By dividing this composite into two parts in a subsequent step, it becomes a composite that can be electrically conductive from the sides of the composite.

Example 3 In Example 1, the ceramic plate was made of aluminum nitride (Al
A pattern-treated composite board was obtained in the same manner as in Example 1 except that N).

Example 4 A pattern-treated composite board was obtained in the same manner as in Example 2, except that aluminum nitride was used as the ceramic board.

Example B (evaluation of composite) Regarding the patterned composite obtained in Example A,
As a result of measuring the electrical resistance between the front and back copper plates, the electrical resistance value of both composites was zero.

[Brief explanation of the drawing]

1 and 2 schematically show examples of composites according to the present invention. FIG. 1 shows a composite in which front and back metal plates are electrically connected through through holes, and FIG. 1 and 2 respectively show a composite body having a dividing groove, and after being divided, the front and back metal plates are electrically connected from the side surface of the composite body. Here, (a) is a plan view of the composite, (b) is a sectional view taken along line AA and B-B, and (a') is a plan view of the composite after division. In addition, 1 is a ceramic plate, 2 is a metal plate (front side), 3 is a metal plate (back side), 4 is a through hole, 5 is a metal powder paste, and 6
indicates a dividing groove.

Claims (4)

[Claims] 1. A ceramic composite comprising metal plates bonded to the front and back surfaces of a ceramic plate, wherein the two metal plates are partially electrically connected by a conductive material. 2. The ceramic composite according to claim 1, wherein the ceramic is aluminum nitride. 3. The ceramic composite according to claim 1, wherein the metal is copper. 4. The ceramic composite according to claim 1, wherein the conductive material is an active metal brazing material.