JPS5935075A - Method of bonding ceramic and metal - 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 The present invention aims to improve a method for bonding ceramics and metals, particularly ceramics and metals having different thermal tensile coefficients.

Conventionally, when ceramics (for example, aluminan) and metal are to be soldered, Kovar metal is selected and joined. If stress remains at the interface between the metallized surface and the metallized surface, the H-shape of the metal from the metallized surface will cause cracks in the ceramic itself, so a metal such as Kovar, which has a coefficient of thermal expansion similar to that of the ceramic, is used.

However, this Kovar metal has poor heat resistance and corrosion resistance, so it has an extremely narrow range of applications.

The present invention has been made in view of the above-mentioned conventional circumstances, and its purpose is to use a desired metal such as stainless steel, which has excellent heat resistance and corrosion resistance and is inexpensive in cost, to ceramics without causing any harmful effects. The purpose of this invention is to provide a method for joining ceramics and metals that can be joined without any problems.

Hereinafter, embodiments of the present invention will be explained based on the drawings.

I will clarify.

The first step is to print a paste of ceramic (for example, alumina substrate), tungsten-molybdenum, molybdenum-manganese, or L tungsten, and bake it at 1400-1600℃ in a humidified reducing atmosphere to form an alumina substrate. 2) A metallizing layer (1) is formed on the surface, and a Nitsunalmeggi layer (4) is further applied as an axis layer.

Next, in the 21st step, the nickel-plated layer (4) is brazed with a slow-moving gold R (2) via a brazing member (3a).

The buffer metal (2) is a thin metal plate (thickness Q, 95 m) such as a stainless steel plate or a nickel plate, which is bonded to the nickel plating layer (4) via a silver solder (3a)' having a melting temperature of about 960°C. do.

At this time, the brazing is performed due to the heat of the sialumina substrate (A) and the buffer gold M (2), which have a thermal expansion coefficient (ceramics, 75 to 85).
X10-'/℃1. x, fless 110-185X10
Although residual stress is generated at the interface due to the difference in temperature (-7/℃),
The easy elastic deformation of buffer metal 8 (2) is alleviated,
It is not transmitted to the metallized M (S) and alumina substrate (G), and prevents peeling from the metallized layer (υ) and cracking of the alumina substrate.

In this state, the target gold M), for example, stainless steel (1
The preparation process for joining 3) has been completed, and as a subsequent process, a nickel plating layer (4) is coated with a koji layer via a low melting point brazing metal #I (3'h) (silver, lily-based). It is sufficient to join the gold F4). (8th step) By the way, in the 8th step, there is no problem if the thermal expansion coefficients of the buffer gold N (2) and the target metal (B) are the same, but if the thermal expansion coefficients are different, then Although residual stress is generated at the interface due to this difference, both M (2) and (B) are elastically deformed and relaxed, so there is no risk of peeling.

Note that the buffer metal (2) is one that elastically deforms in response to residual stress generated at the interface with the alumina substrate (A). Even if it is a punched metal, it is finely assembled into a net shape or #i fiber shape. Of course, it is arbitrary.

By the way, it has been experimentally proven that even if ceramic plates bonded with metal using the process described above are subjected to rapid cooling and heating cycles from 800℃ to room temperature several dozen times, no abnormalities will be observed in the bonded areas. It was done.

In addition, metallizing layer (1), nickel plating layer (4)
on a laminated alumina substrate), a nickel plating layer (4
) of stainless steel (
When a ceramic plate is formed by directly joining IH (IH) through brazing (3), the residual stress generated due to the difference in thermal expansion coefficient at the interface between the alumina substrate and the stainless steel (IB) is directly applied to the alumina. It acts on the substrate (A), causing a crack in the alumina substrate (A), and the buffer metal (2) is then passed through the buffer metal (2) to form the alumina substrate), the buffer metal R (2), and the ribbon metal M (2). Gold J-4 (B) is simultaneously soldered (in the case of -, residual stress generated at the respective interfaces due to the difference in coefficient of thermal expansion acts on the metallizing layer 0). Experiments have shown that this can lead to peeling.

Then, [゛γ alumina substrate] and the target gold M
(n), a buffer gold N (2) must be interposed between the buffer gold #I and the alumina substrate (A).
The process of brazing the buffer metal (2) and the process of brazing the target gold ω) to the buffer metal (2) must be separate J: culm. The metal to which the metal (13) is brazed is the alumina substrate (a)
) to &ll gold metal 2) ↓ M K J
Theoretically, 1'sY is clear that t is very strong unless it has a low melting point.

In the present invention, as described above, metallizing is performed on the ceramic layer, and the metallizing layer is laminated with a buffer layer through the gold layer. ,
The second step is to braze the target metal to the buffer metal using a low melting point brazing metal. When brazing, stress is generated at the interface between the alumina substrate and the buffer metal (due to the heat generated by the brazing material) due to the difference in coefficient of thermal expansion, but this stress is alleviated by the elastic deformation of the buffer metal, which easily breaks. , it is not transmitted to ceramics and forms a base to which the desired metal can be bonded.

Therefore, if the desired metal is bonded to the buffer metal via the low melting point brazing metal 4, the desired metal can be bonded to the ceramic without any problem. The stress is relaxed by the buffer metal and the target metal, and is not transmitted to the metallizing layer or ceramics, so that peeling of the metallizing layer or cracking of the ceramics does not occur.

Claims (1)

[Claims] The first step is metallizing the ceramic, the second step is laminating the buffer metal on the metallized layer with the metal intervening, and the buffer metal is laminated with the above wax (-jkJ).
Brazing with a lower melting point than the golden rule brazing the target gold P4 through the metal 7]: Method for joining metal and ceramics consisting of culm 1,