JPS60231474A - Method of soldering 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] Industrial Application Field The present invention relates to brazing of dissimilar materials such as ceramic and metal, and more specifically, the brazing of ceramic substrates and protective containers of electronic components used in electronics, etc. The present invention relates to a method of brazing and joining metal bases under an inert atmosphere.

Structure of the conventional example and its problems A typical example of this type of brazing method is the joining of high-temperature electronic parts as shown in FIG. This is number 100
This is the bonding configuration of the head part of a thermistor used at high temperatures of 30 to 30 degrees. In the figure, between the substantially smooth main surface of the ceramic base material 1 and the metal base material 2, there is an active metal 3 and a metal 4 with m4 attached. They are joined by brazing through a joining layer. The ceramic base material 1 is a thermistor element part and is made of aluminumite, magnesia, etc. having SiO2 in its components and has a size of about 6 mm.
The substrate has a size of 2×2 mm and a thickness of 0.5 mm, and a temperature-sensitive resistor film 11 made of a thin film of SiC or the like and an electrode 12 are formed on the smooth main surface on the opposite side of the joint.

After brazing, the lead wire 5 is connected to a control circuit or the like via the electrode 12. The metal base material 2 is a protective container for protecting the element portion, and is made of a stainless steel material of about 0.5111111 or the like.

In addition, as shown in Fig. 2, the brazing is performed between the ceramic surface of the ceramic base material 1 and the metal base material 2 with a thickness of approximately 1 mm made of Ti, Zr, etc., and approximately the same size as the ceramic base material 1. active metal 3 thin plates and a thickness of approximately 5 mm mainly composed of silver or copper.
The brazing metal 4 having the same dimensions as the ceramic substrate 1 and having a diameter of 0 μm or less is heated in a stacked state to a temperature equal to or higher than the melting point of the brazing metal 4 in a vacuum furnace (not shown) in an inert atmosphere. It is heated and performed. However, in this method, since the solder base materials (active metal 3, ferrule, and raw metal 4) are laminated, the joining positions are likely to shift during soldering (see Figure 3), and the setting time is long. There are problems such as the long time it takes, and as a method to prevent these problems, the solder metal 4 is vacuum-deposited on the active metal 3 and these brazing base materials are integrated. As shown in FIG. 4, the same solder metal 41 as described above is formed into a thin film by vacuum evaporation on a thin plate of the same active metal 31 as described above, and then vacuum soldered in the same manner as in the conventional example. This is a method of attaching.

The area near the bonding interface of the ceramic substrate 1 that has been brazed and bonded using these methods is inside the ceramic surface (about 10 liters in depth).
im , ), 5i02 oxygen molecules and active metal 3 Ti
, Zr and Ti01 undergo a mutual diffusion reaction.
It has been confirmed that an intermediate layer such as O2 is formed to enable strong bonding.

In this manner, the thermistor and the like made of the ceramic base material 1 and the metal base material 2 were brazed.

In the former method, as mentioned above, a thin plate of active metal or brazing metal is laminated between a ceramic base material and a metal base material, and the thin plate is placed in a vacuum furnace, so the thin plate etc. is likely to shift from its designated position. There were drawbacks. The latter method of forming a thin film of steel metal on the active metal surface by vacuum evaporation can make the brazing base material integral, and has the effect of preventing the disadvantages of the former. When an alloy is used as the filler metal for formation, the metal with the lower melting point in the alloy components begins to be vapor deposited, causing a compositional deviation in the deposited film (solder metal). The melting point of a brazing metal with a compositional deviation varies in proportion to the compositional deviation. As a result, there was a drawback that temperature control during vacuum brazing became unstable.

OBJECTS OF THE INVENTION The present invention aims to eliminate such conventional drawbacks, and in a method of brazing a ceramic base material and a metal base material, it eliminates the compositional deviation of the solder metal made of an alloy, and also eliminates the positional deviation of the joint part. It is an object of the present invention to provide a brazing method in which the amount of brazing is extremely small.

Structure of the Invention To achieve this object, the present invention consists of a ceramic base material, a metal base material and a brazing base material, the brazing base material having a brazing metal having an alloy composition on the surface of the active metal. A structure is provided in which a thin film is formed using a sputtering method, and through this brazing base material 17,
Both of the base materials described above were vacuum brazed in an inert atmosphere.

This structure suppresses the compositional deviation of the solder metal made of an alloy, and since the solder (the two metals are integrated with a thin film formed on the surface of the active metal), it is possible to minimize misalignment of electric current at the joint. be.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG. In the drawings, the same numbers as in the prior art are given to the same parts.

In FIG. 4, the ceramic base material 1 is a thermistor element part, and the metal base material 2 is a protective container for protecting the element part, and these were chosen to have the same structure as the conventional example. The brazing base material for joining the two has a thickness of about 50 μm on the active metal 31.
It is a T1 thin plate with almost the same shape as the ceramic base material 1, and its surface has a steel metal 42 mainly composed of silver-copper (about 7 points of common material).
80° C.) was previously formed into a thin film by sputtering. The film thickness was 10 μm or less. The brazing base materials configured in this way are a ceramic base material 1 and a metal base material 2.
Insert them between them, set them so that they are positioned in the same direction, and braze them in a vacuum furnace (vacuum 5 x 10 Torr, heating 850°C x 5).
minutes). After the brazed connection, the connections of the leads 5 are made as shown in FIG. 1 in the same manner as in the conventional series described above.

According to this method, a sputtering method is used to form a thin film of the brazing metal 42 having an alloy composition on the surface of the active metal 310, so there is almost no deviation in the composition of the thin film of the brazing metal 42 formed. Does not occur. In addition, the brazing base material (active metal 31, brazing metal 42) is formed into a thin film and has an integrated structure, which eliminates the need for lamination of the brazing base material, and as a result, prevents misalignment during bonding. and simplify settings.

It should be noted that an intermediate layer of TiO was confirmed at the bonded portion of the ceramic substrate 1, and the mechanical strength was stable, similar to normal bonding in the past.

Next, a thin Zr plate (having the same dimensions as Ti) was selected as the active metal 31, and a solder metal 42 was formed into a thin film by sputtering in the same manner as in the previous embodiment, and further brazing was performed in a vacuum furnace.

As a result, the results were almost the same as those in the above example.

Effects of the Invention As described above, according to the ceramic-to-metal brazing method of the present invention, a sputtering method is used to form a thin film of a brazing metal having an alloy composition on the surface of an active metal. There is almost no deviation in the composition of the solder metal, which has the effect of stabilizing temperature control during brazing. In addition, the brazing base material (
Since the active metal and the brazing metal are integrated, it is possible to prevent problems such as misalignment of the joint and simplification of setting due to the lamination of the brazing base materials as described above.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view showing a typical example of brazing ceramics and metals, Fig. 2 is a cross-sectional view showing a conventional brazing method, Fig. 3 is a plan view explaining the problems of the conventional method, and Fig. FIG. 4 is a sectional view illustrating another conventional brazing method and an embodiment of the method of the present invention. 1...Ceramic base material, 2...Metal base material, 31...Active metal, 42...Brazing metal, 5... Lead wire, 11... Temperature sensitive resistor membrane, 12... Electrode. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2 Figure 3/1 Figure 4 4 (42)

Claims (3)

[Claims] (1) Consists of a ceramic base material, a metal base material, and a brazing base material, and the brazing base material is composed of a thin film formed by sputtering a brazing metal having an alloy composition on the surface of an active metal. . A ceramic-to-metal brazing method in which both of the base materials are vacuum brazed in an inert atmosphere via this brazing base material. (2) A method for brazing ceramic and metal according to claim 1, wherein the ceramic base material has a composition containing SiC2 in its components. (3) The ceramic-to-metal brazing method according to claim 1, wherein the active metal is a metal material such as Ti or Zr. (4) The method for brazing ceramics and metals according to claim 1, wherein the brazing metal has a composition of an alloy of silver and copper.