JP2002160090A - Ag-Cu-In brazing material and method for producing Ag-Cu-In brazing material - Google Patents

Abstract

(57) [Summary] An object of the present invention is to provide a brazing material made of Ag, Cu, and In and having a melting point of 600 ° C. or less, which can be processed at normal temperature. The present invention provides an Ag—Cu—In brazing material comprising Ag, Cu, and In and having a melting point of 600 ° C. or less, wherein In is a matrix and A is contained in the In matrix.
It is an Ag-Cu-In brazing material in which one kind of dispersed phase made of a gCu alloy or two kinds of dispersed phases made of Ag and a dispersed phase made of Cu are dispersed substantially uniformly.
Here, the mixing ratio of Ag, Cu, and In is Ag: 1, respectively.
0 to 70%, Cu: 10 to 70%, In: 20 to 60%
(All by weight).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to an Ag-Cu-In
Related to brazing filler metal. Specifically, Ag-Cu prepared so that the melting point upon re-melting after solidification is 300 to 600 ° C.
The present invention relates to an In-based brazing material having good workability at normal temperature.

[0002]

2. Description of the Related Art A brazing method is a joining method in which a brazing material is heated and melted as a joining material between joining members, and then flows into a gap between joints to join the joints. It is advantageous that the joining temperature suitable for the type of the member, the type of joining, and the like can be freely selected. Therefore, the value of the melting point is important when selecting a brazing material.

[0003] In general, brazing materials are classified into those having a low melting point called soft solder (so-called solder) and those having a high melting point called hard brazing.
Most of the hard solders have melting points of 6
Since the temperature is not lower than 00 ° C., 600
There are few brazing materials with melting points below ℃. However, for example, as in the case of the step brazing method, when a plurality of types of brazing materials having various melting points are required for laminating a plurality of members and joining them stepwise, depending on the melting point of the joining members, Such a brazing material having a melting point of 600 ° C. or less is required.

As such a brazing material having a melting point of 600 ° C. or less, a brazing material made of an Ag—Cu—In ternary alloy is known. The brazing material made of the ternary alloy lowers the melting point of the silver brazing material by alloying low melting point In with an Ag-Cu brazing material (silver brazing material).
The temperature was adjusted to 00 to 600 ° C.

[0005] By the way, ordinary brazing materials are alloyed by melting, mixing, and casting each of the constituent elements in a predetermined composition.
It is formed into various shapes such as linear, thin plate, and powder,
A linear or thin plate shape is generally adopted in consideration of the joining efficiency and the like. Further, the brazing material thus formed is often used after being further cut, punched, or the like, processed into a shape corresponding to the shape of the material to be joined.

[0006]

However, Ag-
The Cu-In brazing material has a problem that workability at normal temperature is poor. This is because, in this ternary alloy, a hard and brittle intermetallic compound is easily formed when alloyed, and the alloy after casting is linearly or thinly formed in the presence of the intermetallic compound. When processing into a shape, not only processing becomes difficult, but also cracks tend to occur. Therefore, it is impossible to control the shape of the brazing material made of the ternary alloy by processing it during the manufacturing process and during use, and it has to be supplied in powder form.
Furthermore, since the powdered brazing material needs to be mixed into a paste by mixing a binder and a flux when used, the joining process becomes complicated.

The present invention has been made in view of the above background, and is a brazing material made of Ag, Cu, and In and having a melting point of 600 ° C. or less, which can be processed at room temperature. The purpose is to provide. It is another object of the present invention to provide a method for producing the brazing material.

[0008]

The invention according to claim 1 of the present application is an Ag-Cu-In-based brazing material comprising Ag, Cu, and In and having a melting point of 600 ° C or less, wherein In is a matrix, An Ag-Cu-In-based braze in which one kind of a dispersed phase made of an AgCu alloy or two kinds of dispersed phases of a dispersed phase made of Ag and a dispersed phase made of Cu are substantially uniformly dispersed in the In matrix. Material.

In view of the fact that Ag, Cu, and In are dissolved and alloyed to form an intermetallic compound, the present invention considers that In, Ag, and In should not be present during working before use. , Cu are separated so that alloying occurs during use (at the time of melting).
Here, the reason why not only Ag and Cu but also AgCu alloy is used as the disperse phase is that no intermetallic compound is generated even if alloyed in the Ag-Cu system.

[0010] The brazing material according to the present invention having such a structure does not contain a brittle intermetallic compound and has excellent workability of In which is a matrix phase. It can be easily processed into a desired shape according to the joining member. In particular, when it is necessary to process at a high processing rate such as a thin plate or linear shape, In which is a matrix is plastically deformed at an early stage of processing, and an AgCu alloy phase or an Ag phase and a Cu phase which are dispersed phases at a later stage of processing. Is deformed, and this brazing material can be deformed into an arbitrary shape by a two-stage deformation mechanism as the processing proceeds.

In the brazing material according to the present invention, the melting point of the matrix phase and the melting point of the dispersed phase are different from each other. AgCu alloy or Ag or Cu having a higher melting point will be dissolved. In the present invention, this A
By dispersing the gCu alloy or Ag and Cu substantially uniformly, the melting of the dispersed phase is promoted, and uniform alloying occurs in the melting process. Then, the brazing material after solidification (after joining) is homogeneous Ag
It becomes a CuIn alloy and its melting point shows a substantially constant melting point with a small width similar to that of a normal AgCuIn alloy.

The shape of the disperse phase here is not particularly limited. Any shape that can be discontinuous and substantially uniformly scattered in the brazing material may be used, from a circular or elliptical cross section to a needle shape. It may be. In particular, when a brazing material having a relatively large thickness after the manufacturing process is formed into a thin plate by rolling or the like, the dispersed phase is also deformed with the processing, and for example, the granular dispersed phase is processed during forming. It becomes an elliptical shape or a needle shape.

In the present invention, the composition, particularly the concentration of In, is determined in consideration of workability in addition to its melting point. In this Ag-Cu-In ternary alloy,
In lowers the melting point of the entire alloy, and is the softest metal, and has the effect of securing the workability of the brazing filler metal as a binder for the dispersed phase. That is, while the workability of the brazing material is improved by increasing the In concentration,
If the concentration is too high, the melting point of the brazing material will be too low. According to the present inventors, the Ag-
In the Cu-In-based brazing material, Ag, Cu, and In are Ag: 10 to 70%, Cu: 10 to 70%, and In:
It is preferable to mix at a ratio of 20 to 60% (all by weight). In order to make the workability particularly good at this time, it is preferable to contain In at 30% or more.

As the disperse phase, there are a case where Ag and Cu are dispersed in a state of a single metal, and a case where an AgCu alloy is dispersed. More preferably, the one in which an AgCu alloy is dispersed is preferable. Since the melting point of the dispersed phase is lower than that of Ag and Cu alone by alloying both, the difference in melting point from In as the matrix is reduced, and the melting temperature width of the brazing material at the time of joining is reduced. This is because alloying at that time can be further promoted.

When the dispersed phase is an AgCu alloy, the composition of the AgCu alloy is 10 to 70% by weight of Cu.
When the concentration of the AgCu alloy phase is in this range, in order to provide the composition of Ag, Cu, and In described in claim 2, the dispersed phase and In are mixed at a ratio of 4: 6 to 8: 2. Mixing is preferred.

Next, a method for producing the Ag—Cu—In brazing material according to the present invention will be described. As described above, the brazing material according to the present invention is required to have an AgCu alloy or Ag and Cu dispersed uniformly as a dispersed phase in an In matrix. As a method for that, since the melting point of In is relatively low, a method of casting AgCu alloy powder or Ag powder and Cu powder into molten In while dispersing the dispersed phase by stirring and dispersing the dispersed phase is also conceivable. But how I
Even if n has a low melting point and the temperature of molten In is relatively low,
When an AgCu alloy or Ag and Cu are introduced into molten In, alloying occurs slightly at the interface between In and the dispersed phase, and an intermetallic compound is generated. Accordingly, the present inventors have proposed a method of mixing Ag, Cu, and In without uniformly dispersing the dispersed phase and causing alloying at all, by mixing powders of respective metals and compression-molding them in a cold state. Appropriate. That is, as described in claim 4, In
The powder and the AgCu alloy powder or the In powder, the Ag powder and the Cu powder are mixed to form a mixed powder, and the mixed powder is subjected to press molding at room temperature.

According to this manufacturing method, the composition of the brazing filler metal can be adjusted by adjusting the weight of each powder, so that it is relatively easy, and the mixing is sufficiently performed in the step of manufacturing the mixed powder. AgCu powder or Ag
Powder and Cu powder can be uniformly dispersed, and the dispersed phase after molding can be uniformly dispersed. Furthermore, since In is a soft metal, it can be obtained only by press molding at room temperature.
The powders are combined with each other to produce a dense brazing material.

Here, the particle size of each metal powder as a raw material is not particularly limited, but AgCu powder or A
g powder and Cu powder, the particle size is 5 to 150 μm
It is preferable to use those having a range of m. The brazing material according to the present invention may be processed into a foil shape of, for example, 100 μm or less. When a powder having a size of 5 μm or less is used as a dispersed phase as a raw material, the brazing material after molding is processed at a high processing rate. This is because it is difficult to perform processing into a foil shape requiring a high processing rate. This is because if the particle size of the dispersed phase particles is too small, the surface area where the In matrix and the dispersed phase are in contact increases, and the frictional force at the interface between the In matrix and the dispersed phase increases when the matrix is deformed during processing. it is conceivable that. On the other hand, when a powder having a size of 150 μm or more is used as the dispersed phase as a raw material, it is difficult to uniformly mix the powder constituting the dispersed phase. Then, considering the processing rate of such a brazing material, A
The particle size of gCu powder or Ag powder and Cu powder is 50 to 90.
It is particularly preferable to set it to μm. It is not necessary to particularly consider the particle size of the In powder constituting the matrix. The method for producing each powder is not particularly limited, and powders produced by any method such as a pulverization method and an atomizing method (gas atomizing method, water atomizing method) can be used.

The compression stress at the time of press-molding the mixed powder is preferably from 250 to 750 MPa. If the pressure is less than 250 MPa, it is not possible to produce a dense and complete molded body. In order to generate a compressive stress of 750 MPa or more, large-scale equipment is required and the cost of the product is increased. is there.

The shape and dimensions of the brazing material manufactured by the above method can be adjusted by the shape of the die when the raw material powder is compressed. However, in order to efficiently manufacture a thin or linear brazing material, it is preferable to perform rolling or drawing on the formed brazing material. Since the brazing material according to the present invention has good workability at normal temperature, a large ingot-shaped or billet-shaped molded body is produced during press molding, and the thinner or linear brazing material is preferably processed. Can be continuously mass-produced.

When the brazing material after press forming is rolled, it is preferable to use a grooved roll as a rolling roll. Although the brazing material after compacting is dense, since powder is used as a raw material, the edges have minute irregularities, so when rolling with flat rolls, local stress concentration occurs at the edges and cracks occur This is to prevent this, since there is a possibility of this.

[0022]

Preferred embodiments of the present invention will be described below.

First embodiment : 5 obtained by classification processing
Ag-47.1w of 0 to 90 μm (average particle size of 50 μm)
620 g of the t% Cu powder and 380 g of an In powder of 325 mesh or less (average particle size of 30 μm) were mixed by a V-shaped mixer (mixing ratio: 62:38) to produce a raw material powder. Here, the manufacturing method of each powder is the atomization method for all powders. Then, the raw material powder was sufficiently stirred and mixed, put into a mold having an inner diameter of 50 mm, and press-molded at 150 ton (compression stress: 748.7 MPa) to obtain an ingot.

The ingot thus formed was extruded by an extruder to a width of 30 mm and a thickness of 1.5 mm, and further processed into a foil of 30 μm thickness by a rolling mill.

FIGS. 1 and 2 show the cross-sectional structure of this brazing material. FIG. 1 shows a cross-sectional structure after a mixture of Ag-47.1 wt% Cu powder and In powder and press molding. The spherical phase in FIG. 1 is AgCu powder. On the other hand, FIG. 2 is a cross-sectional structure of a brazing material that has been subjected to rolling after press forming. 2, the cross-section of the brazing material after the rolling process maintains the cross-sectional shape at the time of press forming, and the dispersed phase is substantially uniformly dispersed.

Second Embodiment : In this embodiment, an Ag-28.0 wt% Cu powder is used in place of the Ag-47.1 wt% Cu powder used as the disperse phase in the first embodiment, and a brazing material is formed by the same process. Was manufactured. Ag-28.0wt%
The weights of the Cu powder and the In powder are the same as in the first embodiment. The manufacturing conditions such as the compressive stress after mixing the respective powders were the same as in the first embodiment.

The melting points of the brazing materials according to the first and second embodiments manufactured as described above were re-melted after processing and after melting and solidification, and were measured by DTA analysis (differential thermal analysis).

First, when the melting point of the brazing material according to the first embodiment was measured, it was confirmed that the brazing material after production started to melt at 150 ° C. and completely melted at 560 ° C. Then, when the molten brazing material was solidified and heated again, it was confirmed that the molten material was melted in the vicinity of 470 to 580 ° C. and melted in a temperature range narrower than that after manufacturing.

The melting point of the brazing material according to the second embodiment was measured in the same manner. As in the first embodiment, the brazing material after production started to melt at 150 ° C.
It melted completely at ℃. The re-melting temperature is 310
It was confirmed to dissolve in the vicinity of ℃ 560 ° C.

[0030]

As described above, according to the present invention, the Ag-
The Cu-In brazing material uses In as a matrix,
In the n matrix, one kind of dispersed phase composed of AgCu alloy, or two kinds of dispersed phase of dispersed phase composed of Ag and dispersed phase composed of Cu, is uniformly dispersed,
This allows processing at room temperature. Therefore, shape control such as a thin plate or a line is easy, and further, cutting and punching according to the shape of the joining member at the time of use are easy. Also, the brazing material according to the present invention has a relatively wide melting temperature range at the time of joining, but once melt-solidified,
It becomes a complete Ag-Cu-In alloy and forms a joint having a desired melting point.

The brazing material according to the present invention can be manufactured by mixing and molding powders of the respective constituent metals, and optionally extruding and / or rolling. This method is a relatively easy method, and can efficiently produce a brazing material having a desired shape.

[Brief description of the drawings]

FIG. 1 is a view showing a cross-sectional structure of an ingot after press-molding a mixed powder of an AgCu powder and an In powder according to a first embodiment.

FIG. 2 is a view showing a cross-sectional structure of a brazing material manufactured by rolling an ingot after press forming in the first embodiment.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C22C 5/08 C22C 5/08 9/00 9/00 28/00 28/00 B // C22C 1/04 1/04 AE (72) Inventor Hiroyuki Kusamori 2-73, Shinmachi, Hiratsuka-shi, Kanagawa Prefecture F-term in the Hiratsuka Plant of Tanaka Kikinzoku Kogyo Co., Ltd. 4K018 AA02 AA04 AA40 BA20 BC12 CA02 CA11 CA32 KA70

Claims (7)

[Claims] 1. An alloy comprising Ag, Cu, In and having a melting point of 600.
An Ag-Cu-In-based brazing material having a temperature of not more than 0 ° C.
An Ag-Cu-In brazing material in which one kind of dispersed phase made of a Cu alloy or two kinds of dispersed phases made of Ag and a dispersed phase made of Cu are substantially uniformly dispersed. 2. Ag, Cu and In are each Ag: 10-7.
2. The composition A according to claim 1, wherein the composition is mixed at a ratio of 0%, Cu: 10 to 70%, and In: 20 to 60% (all by weight).
g-Cu-In-based brazing material. 3. The dispersed phase is composed of 10 to 70% by weight of AgCu.
Alloy, wherein the dispersed phase and the In matrix phase are 4: 6
3. The composition according to claim 1, wherein the composition is mixed at a ratio of .about.8: 2.
The described Ag-Cu-In brazing material. 4. The Ag-Cu-I according to claim 1,
A method for producing an n-type brazing filler metal, comprising: an In powder and an AgCu alloy powder;
A method for producing an Ag-Cu-In brazing material, comprising mixing a g powder and a Cu powder to form a mixed powder, and press-forming the mixed powder at room temperature. 5. The Ag-Cu-I according to claim 4, wherein the mixed powder is press-formed at a compression stress of 250 to 750 MPa.
A method for producing an n-type brazing material. 6. The method for producing an Ag—Cu—In brazing material according to claim 4, wherein an AgCu alloy or an Ag powder and a Cu powder having a particle size of 5 to 150 μm and an In powder are mixed. 7. The brazing material after molding is further extruded and / or
The method for producing an Ag-Cu-In-based brazing material according to any one of claims 4 to 6, further comprising a step of rolling.