JPH04187574A - Soldering material composition - Google Patents

Abstract

PURPOSE:To make it possible to form a soldering material layer having excellent fluidity, uniformity and activity and consisting of flat thin film and free from defect, by mixing a hydride of active metal with specific globular silver copper alloy power. CONSTITUTION:(A) hydride of active metal (titanium hydride) is mixed with (B) globular silver-copper alloy powder obtained by atomizing the alloy powder using high-pressure water, dehydrating and drying the alloy powder and subjecting the alloy powder to hydrogenation treatment at need to obtain the material having <=0.3wt.% oxygen content and 1-15mum average particle diameter.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a brazing filler metal composition containing an active metal used for joining metals and ceramics.

[Prior Art] As a brazing material for joining metal and ceramics, a brazing material made by adding active metal powder such as Ti, Zr, or Hf to a silver solder is known. Conventionally, the following (1), (
There is 2).

(1) Alloy powder with Ti added to the wax phase component.

In order to avoid oxidation of Ti, such alloys are often manufactured by a gas atomization method, and there is a limit to grain size reduction. When joining metals and ceramics, there is a tendency to form a brazing filler metal layer as thin as possible in order to reduce residual stress at the joint, and there is also a demand for finer particles in the brazing filler metal paste material, and this alloy powder meets that requirement. does not match.

(2) A mixed powder obtained by adding Ti powder or TiH2 powder to a mixed powder having a waxy phase component composition.

In such a mixed powder, there is a problem that the Ti fine powder is easily oxidized and ignited, and this problem can be solved by using TiH2 as an active metal supply source, but in any case, in the form of a mixture, the mixed powder composition is segregated. The problem is that it is easy.

In general, water atomization is a method for producing fine powder with an average particle size of 50 um or more, but there is a limit to its ability to make fine particles. The liquid phase reduction method is a common method for producing fine powder with an average particle size of 1 μm or less, but the liquid phase reduction method has problems in that the particles produced are poor in shape and the particle size is too small, resulting in agglomeration and oxidation.

[Problems to be Solved by the Invention] An object of the present invention is to provide a brazing filler metal composition that eliminates the above-mentioned drawbacks.

[Means for Solving the Problems] The present invention consists of: ■ Active metal hydride ■ Oxygen content of 0.3% by weight or less, average particle size of 1 to 15μ
This is a brazing filler metal composition composed of three spherical silver-copper alloy powders.

[Function] The brazing material of the present invention mixes active metal hydride powder with spherical silver copper powder, so it has excellent fluidity, uniformity, and activity during bonding, is suitable for screen printing, and is suitable for bonding metals and ceramics. Ideal for

Spherical silver-copper alloy powder is produced from molten silver-copper alloy by, for example, high-pressure water atomization, and is made into spherical particles. Such spherical properties are defined from the viewpoint of good printability.

If the average particle size of the spherical silver-copper alloy powder is less than 1 μm, it is likely to aggregate or oxidize, so the lower limit is set to 1 μm on average. Further, the upper limit is set to 15 μm on average because it is necessary to form a flat film with a thickness of 35 μm or less, and if it exceeds 15 μm, large particles will be mixed in, which is undesirable, so it is limited to 15 μm. Particles with an average particle size of 1 μm to 15 μm are easy to use when forming a flat thin film, and are suitable for high-pressure water atomization.
It can be easily manufactured.

The lower the amount of oxygen in the silver-copper alloy powder, the better.
．． If it exceeds 3% by weight, the amount of oxides formed on the surface increases, which tends to cause unfused portions during bonding, resulting in poor fluidity. Therefore, the upper limit was limited to 0.3% by weight.

Such spherical silver-copper alloy powder can be obtained by water atomization using high-pressure water, and after atomization, dehydration, drying, and hydrogen reduction treatment as required, the oxygen content can be reduced to 0. It is possible to suppress the amount to 3 parts by weight or less.

The brazing filler metal composition of the present invention, which is composed of activated gold X hydride and spherical silver-copper alloy powder, has the following excellent characteristics.

(a) Since the wax phase components are alloyed, there is no need to worry about segregation.

(b) It is spherical and has excellent printability.

(C) Since the average particle size is 1 to 15 μm, it is possible to form a thin brazing filler metal layer.

(d) There is no need to worry about agglomeration resulting in decreased density or non-uniformity.

(e) Since the oxygen content is kept low, fluidity is ensured.

[Example] A silver-copper eutectic alloy powder with an oxygen content of 0.2% by weight and an average particle size of 12 μm was produced by high-pressure water atomization, and 2% by weight of titanium hydride was mixed therein to produce an example of the present invention. A brazing filler metal composition was obtained. A binder was mixed into this brazing filler metal composition to form a paste with a viscosity of 60.000 cps, and the paste was screen printed on an AJN substrate.

3 on A42N board of 50X50X thickness 0.625mm
After printing and drying a brazing material layer of 0 to 50 μm, a 45×45×0.3 mm thick copper plate was placed thereon and baked at 900° C. for 8 hours under vacuum to create an AβN substrate.

When we inspected the joint for defects, no defects were detected by ultrasonic flaw detection equipment.

As a comparative example, when similar treatment was carried out using liquid-phase reduced ultrafine powder with an average particle size of less than 1 μm, wax cuts occurred in the agglomerated portions. Further, the residual stress was large when a brazing material layer having a thickness of 100 μm was formed using gas atomized powder with an average particle size of 50 μm. Furthermore, in a comparative example using silver-copper atomized powder with an average particle diameter of 2 μm and an oxygen content of 1% by weight, it was observed that the brazing filler metal was partially unmelted. In addition, in the case of using grape cluster-shaped silver copper powder having an average particle size of 3 μm, the density was low when the brazing material was made into a paste, resulting in poor bonding.

“Effects of the Invention” The brazing filler metal composition of the present invention is used for joining metals and ceramics, and has excellent fluidity, uniformity, and activity, and is suitable for forming a flat, thin, defect-free brazing filler metal layer. It has excellent properties.

Claims (1)

[Claims] 1. A brazing filler metal composition comprising an active metal hydride and a spherical silver-copper alloy powder having an oxygen content of 0.3% by weight or less and an average particle size of 1 to 15 μm.