JPH07223878A - Production of joined body composed of ceramics and metal - Google Patents

Abstract

PURPOSE:To remarkably enhance the productivity and produce a joined body of ceramics to a metal without impairing the surface conditions of the metal and joining strength of the metal to the ceramics. CONSTITUTION:This method for producing a joined body composed of ceramics and a metal is to superimpose 2 or 3 or more units comprising each laminate prepared by superimposing ceramics to a metallic circuit and/or a metallic plate for forming the metallic circuit with or without interposing a brazing filler material containing an active metal as one unit through spacers composed of ceramics having a nonoxide layer on the surface thereof and heat the resultant superposed units comprising the laminates in thermally joining the superimposed units comprising the laminates.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a joined body composed of ceramics and a metal circuit and / or a metal plate for forming a metal circuit.

[0002]

2. Description of the Related Art Conventionally, as a method for joining a metal circuit or a metal plate for forming a metal circuit to a ceramic substrate, a ceramic substrate and a metal plate for forming a metal circuit and / or a metal circuit for interposing a brazing material containing an active metal have been used. The active metal method of heating and bonding a laminate with and under high vacuum (JP-A-60-17763).
No. 4), a direct laminate of an oxide ceramic substrate or an aluminum nitride substrate obtained by oxidizing the surface and a copper circuit and / or a copper plate for forming a copper circuit is formed at a temperature not higher than the melting point of copper by Cu-
DBC method in which heat bonding is performed at a temperature higher than the eutectic temperature of O (Japanese Patent Laid-Open No. Sho 56-56)
No. 163093) is generally adopted. Furthermore, Si, Al, Mg, Ca, F on the ceramic substrate
Metallization treatment with a refractory metal such as Mo, Mn, and W is performed through a metal oxide such as e, and then a metal circuit and / or a metal plate for forming a metal circuit is laminated through a brazing material containing no active metal. There is also a metallizing method in which it is heated and joined under high vacuum.

[0003]

However, in the active metal method or the DBC method, the laminated body of the ceramic substrate and the metal circuit and / or the metal plate for forming the metal circuit is heat-bonded as one unit. Productivity was poor. In order to solve this drawback, two or more units may be laminated and heat treated, but in this case, there is a problem that the metals are fused and peeling becomes difficult.

Therefore, based on the idea that a spacer may be sandwiched between the units and heated, the required properties of the spacer are that the volume is small, it does not deform at the heat treatment temperature, or it does not deform significantly even if it deforms. As a result of various studies from the standpoints of chemical stability, repeated use, no deviation, easy availability, etc., it was found that ceramics having a non-oxide layer on the surface is suitable as a spacer. The present invention has been completed.

[0005]

That is, according to the present invention, a laminated body in which ceramics and a metal circuit and / or a metal plate for forming a metal circuit are laminated with or without a brazing material containing an active metal is heated. In joining, two or three or more units each having the above-mentioned laminated body as one unit are laminated through a spacer made of ceramics having a non-oxide layer on the surface, and the laminated body is heated. It is a manufacturing method of a joined body.

The present invention will be described in more detail below. As for the ceramic substrate, the metal plate for forming the metal circuit or the gold layer circuit, the brazing material containing the active metal, etc. used in the present invention, the conventional one is sufficient. , And their outlines are as follows.

Aluminum nitride substrates, alumina substrates, mullite substrates, etc. are used as ceramic substrates.
Among them, an aluminum nitride substrate is generally used in the active metal method and the metallizing method, an alumina substrate, a mullite substrate, and an aluminum nitride substrate whose surface is oxidized in the DBC method. The thickness of the ceramic substrate is 0.3-
0.8 mm is desirable, and if it is thinner than 0.3 mm, the durability against thermal shock is reduced, and it is 0.8 m.
If it exceeds m, the thermal resistance decreases.

The material of the metal circuit and / or the metal plate for forming the metal circuit is copper in the case of the DBC method, and copper, aluminum, tungsten, molybdenum, etc. in the case of the active metal method and the metallizing method. , Copper is common.
The thickness of the metal circuit or the metal plate for forming the metal circuit is preferably thicker than 0.3 mm from the tendency that the current density is improved in recent years. Usually, the metal circuit and / or the metal plate for forming the metal circuit is bonded to one surface of the ceramic substrate and the metal heat radiating plate is bonded to the other surface, but there is a structure in which the metal heat radiating plate is not provided. The above-mentioned materials are used as the material of the metal radiator plate, and the thickness thereof is preferably 0.2 mm or less.

The metal component of the brazing filler metal in the active metal method is
It contains silver and copper as main components, and an active metal as a sub-component in order to ensure wettability with the ceramic substrate during melting. Specific examples of the active metal component include titanium, zirconium, hafnium, niobium, tantalum, vanadium and compounds and alloys containing these components. The ratio of these metal components is 69 to 75 parts by weight of silver and 25 to 31 of copper.
3 to 35 parts by weight of the active metal per 100 parts by weight of the total weight part.

The brazing filler metal used in the active metal method or the metallizing method is usually used as a paste, which is prepared by adding an organic solvent and, if necessary, an organic binder to the metal component of the brazing filler metal, and using a roll, kneader or Banbury mixer. It can be prepared by mixing with a universal mixer, a ladle machine or the like. As the organic solvent, methyl cellosolve, ethyl cellosolve, terpineol, isophorone, toluene, etc., and as the organic binder, ethyl cellulose, methyl cellulose, polymethyl methacrylate, etc. are used.

In the case of the active metal method or the metallizing method,
The brazing material paste is applied to both sides of the ceramic substrate by screen printing, roll coater method, brush coating, etc., then a metal circuit and / or a metal plate for forming a metal circuit is formed on one surface thereof, and a metal plate is formed on the other surface thereof. The heat sinks are typically stacked to form one unit of stack. DBC
In the case of the method, a copper circuit and / or a copper plate for forming a copper circuit and a ceramics substrate are directly laminated without using a brazing paste to form one unit of a laminated body.

According to the present invention, two or more units each having a laminate formed by the active metal method or the metallization method as one unit or two or more units having a laminate formed by the DBC method as one unit are used. The units are stacked with a spacer made of ceramics having a non-oxide layer on the surface, and the units are heat-treated and bonded. The heat treatment conditions are, under the high vacuum of 1 × 10 ⁻⁵ Torr, in the case of a laminated body of units by the active metal method or the metallization method,
The temperature is 800 to 950 ° C. for 0.1 to 1 hour, while
In the case of a laminated body of units by the DBC method, 0.1 at a temperature of 1063 to 1083 ° C. in a non-oxidizing atmosphere such as N _2.
~ 1 hour.

A major feature of the present invention is that a ceramic having a non-oxide layer on its surface is used as a spacer. Specifically, aluminum nitride, silicon nitride,
Non-oxide ceramics such as those made of silicon carbide, or surfaces of these non-oxide ceramics or oxide ceramics such as alumina and mullite are coated with graphite or BN by a spray method, a chemical vapor decomposition method, or the like. It is a thing. The size of the spacer may be about the same as the width of the laminated body. If it is too narrow, joint failure may occur in the surrounding area due to insufficient load, and if it is too wide, there may be a gap between the laminate itself or between the laminates. Poor bonding or breakage. Further, the thickness is preferably 0.2 to 1 mm from the viewpoints of handleability, durability in repeated use, and volume efficiency. In the present invention, it is preferable to place a weight of tungsten, tantalum, molybdenum, BN, Si ₃ N ₄ or the like on the uppermost surface of a plurality of units stacked with a spacer interposed therebetween in order to prevent uneven load.

[0014]

EXAMPLES The present invention will be described more specifically with reference to Examples, Comparative Examples and Reference Examples.

Example 1 Aluminum nitride substrate (60 mm × 40 mm × thickness: 0.
635 mm) on both sides, silver powder 72 parts by weight, copper powder 28
Parts by weight, 20 parts by weight of titanium powder, 15 parts by weight of terpineol and 1 part by weight of a toluene solution of ethyl cellulose as an organic binder in a solid content are mixed, and a brazing material paste containing an active metal is applied to a circuit pattern. After drying, a copper circuit punched into the same shape as the circuit pattern was laminated thereon.

20 units of the obtained laminated body as one unit are laminated by interposing an aluminum nitride plate having the same size as the above-mentioned aluminum nitride substrate as a spacer between the units, and 8 g / cm ² of tungsten is placed on the uppermost surface thereof. After placing the weight, the temperature is 850 ° C and the degree of vacuum is 1 × 10 ^-5 t
Heat treatment was performed for 30 minutes in an atmosphere of orr.

The peel strength (maximum value, minimum value, average value), surface condition of the copper circuit, and
The adhered state of the spacers, the repeated service life, and the displacement of the spacers when laminating the laminate were measured as follows. The results are shown in Table 1.

(1) Peel strength: Measured at a pulling speed of 50 mm / min using a commercially available measuring instrument. (2) Surface condition of copper circuit: Visual observation, ⊚: No difference before and after joining, ◯: Adhesion on copper circuit surface,
Poor: The copper circuit surface was evaluated for unevenness. (3) Spacer adhesion state: The number of spacers adhered was measured. (4) Repeated use life of spacer: 1 spacer
Visual observation of the situation after repeated use of 00 times, ◎:
There was no abnormality, ∘: occurrence of abnormality by 80 times, and x: occurrence of abnormality by 10 times. (5) Deviation during lamination: The presence or absence of deviation of the laminate when a load is applied was visually observed.

Example 2 A bonded body was manufactured in the same manner as in Example 1 except that an aluminum nitride plate coated with carbon spray (trade name "DGF" manufactured by Nippon Ship Tool Co., Ltd.) was used as the spacer. .

Example 3 A joined body was produced in the same manner as in Example 1 except that an aluminum nitride plate coated with BN spray (product name "Boron Spray" manufactured by Denki Kagaku Kogyo Co., Ltd.) was used as the spacer. did.

Example 4 As a spacer, an alumina plate (60 mm × 40 mm ×
A joined body was produced in the same manner as in Example 1 except that a BN spray was applied to a thickness of 0.635 mm).

Example 5 As a spacer, about 5 mm around an aluminum nitride plate
A joined body was produced in the same manner as in Example 1 except that only the BN spray-coated one was used.

Example 6 A bonded body was manufactured in the same manner as in Example 1 except that a laminated body obtained by directly laminating a tough pitch copper circuit punched into the same shape as a circuit pattern on an aluminum nitride substrate was used. did.

Example 7 An aluminum nitride substrate was subjected to an oxidation treatment to form an Al ₂ O ₃ layer, the surface of which was subjected to a metallization treatment by the Mo-Mn method, and the titanium powder was removed from the brazing material paste. A bonded body was manufactured in the same manner as in Example 1 except that a laminated body obtained by laminating copper circuits via a paste was used.

Comparative Example 1 A bonded body was manufactured in the same manner as in Example 1 except that no spacer was used.

Comparative Example 2 A bonded body was manufactured in the same manner as in Example 1 except that the spacer was an alumina plate (60 mm × 40 mm × thickness 0.635 mm).

Comparative Example 3 A spacer is made of carbon paper (UCAR Carbo).
A bonded body was manufactured in the same manner as in Example 1 except that the product was manufactured by N Company.

Reference Example (Conventional Example) A bonded body was manufactured in the same manner as in Example 1 except that a laminated body of only one unit was used without using a spacer.

[0029]

[Table 1]

[0030]

According to the present invention, it is possible to manufacture a bonded body of ceramics and metal with significantly improved productivity without deteriorating the surface condition of metal and the bonding strength of metal and ceramics.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Akira Miyai 1 Shinkai-cho, Omuta-shi, Fukuoka Prefecture Electrochemical Industry Co., Ltd. Omuta Factory (72) Inventor Koichi Uchino 1 Shinkai-machi, Omuta-shi, Fukuoka Electrochemical Industry Co., Ltd. Omuta Factory

Claims (1)

[Claims] 1. A unit of the above-mentioned laminated body for heating and joining a laminated body in which ceramics and a metal plate for forming a metal circuit and / or a metal circuit are laminated with or without interposing a brazing material containing an active metal. 2. A method for producing a bonded body made of ceramics and metal, comprising laminating 2 or 3 or more units of the above through a spacer made of ceramics having a non-oxide layer on the surface and heating it.