JPS63212077A - Solid phase joining method - Google Patents

Abstract

PURPOSE:To economically perform the solid phase joining of a large area by removing contaminated layers of the joining surfaces and the surface of In-Sn alloy foil containing the specific quantity of Sn in vacuum and superposing the joining surfaces mutually via the In-Sn alloy foil. CONSTITUTION:Materials 1 and 2 (copper, etc.) to be joined and insert material (the In-Sn alloy foil) 3 are set up in a joining chamber 4. The insert material 3 is composed of the In-Sn alloy foil containing 25-75wt.% Sn. The inside of the joining chamber 4 is evacuated in a vacuum (about 10<-8>Torr) state and Ar gas, etc., with high purity are flowed in atom sources 5 and 6 and projected on the surface of the insert material 3 set up on the joining surface of an upper material 1 to be joined and a lower material 2 to be joined. At this time, the contaminated layers on the surfaces are removed. Next, the upper material 1 to be joined is descended and subjected to solid-phase joining to the insert material 3. The upper material 1 to be joined is raised and the upper and lower materials 1 and 2 to be joined are subjected to solid-phase joining to each other via the insert material 3 by operating in the same way. In this way, the solid phase joining of the large area can be economically performed.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention is directed to the production of ceramics on gold metal at a temperature around room temperature,
Also, it relates to a method of bonding without giving large distortion to the bonded objects, especially electronic devices and optical components.

The present invention relates to a solid-phase joining method suitable for parts such as precision mechanical parts that must be joined with high precision without straining, deforming, or applying heat to materials.

[Conventional technology]

Conventionally, as described in the Nikkan Kogyo Shimbun (published March 27, 1986), contaminants such as oxides, water, oil, and fat adhering to the bonding surface are completely removed using ion gas, and ultra-high vacuum A method is known in which materials are overlapped and bonded, and according to this method, it is necessary to suppress the unevenness of the surface to be bonded to 1 μm or less.

[Problem that the invention seeks to solve]

In the conventional method, the following steps are essential.

(1) It is necessary to evacuate to an ultra-high vacuum range (10-8 to 10-'' Torr).

(2) The surface roughness of the surface to be bonded must be processed to 1 μm or less.

Therefore, expensive equipment for evacuation to ultra-high vacuum is required, and the time required for evacuation is also quite long. Furthermore, the machining time required to make the surface roughness of the joint surface fine is also long. From the above, it can be said that from an economic point of view, the conventional method is a very expensive joining method. On the other hand, since the bonded surfaces are simply overlapped, there is also the problem that unbonded portions are likely to occur when bonding a large area.

An object of the present invention is to provide a solid-phase bonding method that is economical and capable of bonding large areas at temperatures around room temperature.

[Means for solving problems]

As a means to solve the problem, an In-Sn alloy foil containing 25 to 75% by weight of indium from which the contamination layer on the surface has been removed is inserted as an insert material between the bonding surfaces. That is, specifically, the problem can be solved by using the following joining process.

The material to be joined and the Sn content are 25 to 75% by weight in a vacuum.
The contamination layer on the surface of the In-Sn alloy insert material is removed by irradiation with ions or atoms, and then these surfaces are overlapped and bonded in a solid state without being re-contaminated.

[Effect]

The technical means implemented in the present invention work as follows.

Irradiating ions or atoms to both the bonding surface and the surface of the In-Sn alloy foil in vacuum removes contaminants (
This is to remove oxide film, moisture, oil and fat, etc.) and activate the surface. Furthermore, the purpose of irradiating in vacuum is to prevent re-contamination of the surface after irradiation.

The reason for inserting the In-Sn alloy foil containing 25 to 75% by weight of tin (Sn) between the joint surfaces is to improve the adhesion of the joint and promote chemical bonding. I of the above composition
Since the n-Sn alloy is soft and does not easily form a stable oxide film, it is very suitable as an insert material for in-phase bonding. Therefore, unlike conventional methods, there is no need to maintain the bonding atmosphere at an ultra-high vacuum, and the surface roughness of the bonded surface can be reduced to 1 μm.
There is no need to finish the joint to a thickness of less than m.Furthermore, since the soft In--Sn alloy is inserted, the effect of waviness on the joint surface is small, and a large area can be joined.

〔Example〕

An example of joining copper to copper will be described.

In-Sn alloy foil with varying In content used as an insert material in butt joining between low diameter copper pieces;
Pure In foil and pure Sn foil were used. The joining procedure will be explained with reference to FIG.

The copper bonding materials 1 and 2 and the insert material 3 are placed in the bonding chamber 4, and the chamber is evacuated to 10-'Torr.

Note that the surface roughness of the copper bonding material is 3 to 5 μm.

The insert material 3 rolled to a thickness of 80 μm is placed on the bonding surface of the copper bonding material 2 placed below. Next, add ultra-high purity argon gas (Ar gas) to Atom Source 5.
. After that.

The upper steel bonding material 1 is lowered and overlapped with the insert material 3 to be solid phase bonded to each other. In addition, in this joining, a stress of approximately 0.5 kg/na" was applied to the joining surface. Then, the upper copper joining material 1 was raised to a predetermined position. At this time, the insert material 3 was It is bonded to the surface of the upper copper bonding material 1. Here again, the atom sources 5 and 6
A on the insert material surface and the bonding surface of the lower bonding material 2.
The surface is activated by irradiation with r atoms. Thereafter, the upper joining material 1 is lowered and overlapped with the lower steel joining material 2 to be joined in phase. As a result, the upper copper bonding material 1 and the lower copper bonding material 2 are solid phase bonded via the insert material.

A tensile test was carried out on the bonding materials joined by changing the material of the insert material 3 in the above procedure, and the results shown in FIG. 2 were obtained. As shown in the figure, the Sn content is 25
High bonding strength was obtained when ~75% by weight In-Sn alloy was used as the insert material. After joining, 48
The strength is improved after being left for a while. On the other hand, if the atom source joins without removing contaminants from the joining surface.

It didn't connect at all. From these results, the Sn content is 2
It is found that an In-Sn alloy of 5 to 75 weight percent is suitable.

In the above example, bonding was performed at room temperature.

Even higher bonding strength can be obtained by bonding at a temperature below the solidus line of the In-Sn alloy. For example, when copper heated to 100° C. was joined using the above procedure, a tensile strength of 30 MPa was obtained. This is because heating softens the In-3n alloy to improve adhesion of the bonding surface and to diffuse atoms.

In addition, the softening of the In-Sn alloy by heating reduces the load on the joint surfaces to almost zero (
It can also be joined with a load equivalent to the own weight of the joining material.

On the other hand, even if heat treatment is performed after the bonding material is taken out of the bonding chamber after bonding, the bonding strength is improved. This is because heating promotes diffusion and eliminates defects (voids) that existed in the bonded area.Although we have explained the example of bonding copper to copper, bonding of copper and alumina and bonding of copper and Si also apply. Good results were obtained.

[Effects of the Invention] According to the present invention, since the In-Sn alloy is used as the insert material, there is no need to evacuate to an ultra-high vacuum, and therefore activation becomes easy.

In addition, since it is flexible, it is easy to adhere to it, and no special consideration is required for the surface finish of the bonding surface. Furthermore, it becomes possible to bond a large area.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram for explaining the solid phase bonding method of the present invention, and FIG. 2 is a graph showing the results of a bonding experiment. 1st Figure 1-・Nikenpachibo seat 4-Josuke I Z...-lower g''P clothes station cover 5-11-lose tomoose 3...-inser) tip Otsu---completed munose Z Z Fig.Sn droplet content / Kei amount〆

Claims (1)

[Claims] 1. In a method of solid phase welding by bringing the joint surfaces into contact after removing a contamination layer on the joint surfaces, there is a
Inserting an In-Sn alloy foil containing 75% by weight of tin,
After irradiating both bonding surfaces and both surfaces of the In-Sn alloy foil with ions or atoms in a vacuum to remove the contaminant layer on those surfaces, the In-Sn alloy foil is immediately irradiated with ions or atoms in a vacuum atmosphere. A solid phase bonding method characterized by overlapping bonding surfaces. 2. In the method of claim 1, solid phase joining is characterized in that during or after joining, the joined part is heated to a temperature below the solidus line of the In-Sn alloy and maintained for a predetermined period of time. Method.