JPH05261495A - Peeling method for rapidly cooled and solidified foil in single roll method - Google Patents

Abstract

PURPOSE:To obtain the easy peeling method of solidified foil from a cooling roll by consisting at least the surface of the single roll of an aluminum material. CONSTITUTION:At least the surface of the single roll consists of the aluminum in the method for producing a thin-film amorphous foil strip by ejecting a molten metal consisting of an Au alloy to the surface of the single roll rotating at a high speed and rapidly cooling and solidifying the molten metal. As a result, the foil of the Au alloy, more particularly amorphous Au-Sn alloy foil adequate for a brazing filler metal, etc., is continuously and industrially produced at a good yield by the single roll rapid cooling and solidifying method.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention uses a single roll method for Au.
The present invention relates to a method for peeling a rapidly solidified thin film amorphous foil strip of a system alloy, particularly an Au-Sn alloy, from the cooling single roll.

[0002]

2. Description of the Related Art In recent years, electronic devices have been remarkably miniaturized and increased in speed, and various materials have been developed to meet the demand. In particular, amorphous materials, which are excellent in various required characteristics of electronic devices and which are relatively easy to manufacture, are actively used. For example, an amorphous material of an Au-based alloy is used as a brazing material in a joint portion of a semiconductor device.

Conventionally, the Au-based alloy foil used as a brazing material has been manufactured mainly by the rolling method. However, in the current manufacturing method by the rolling method, the alloy foil is very crystalline because its structure is crystalline. brittle. When used as a brazing material for the semiconductor device or the like, the area is locally small, and there are many parts where bonding accuracy is required. Therefore, a thin shaped shape is required and the edge during rolling is also required. It is necessary to remove cracks and the like, and for that purpose, sizing is carried out as a product or suitable for a desired shape. However, since the brazing material of the Au-based alloy foil manufactured by the rolling method is a brittle material, it is difficult to shape it into a desired shape, and the sizing yield is extremely low, which further increases the manufacturing cost.

As a method of improving this brittleness, there is an amorphization of the foil material. Amorphized foil has extremely homogeneous material and does not become brittle, so sizing can be effectively performed and the yield is dramatically improved. Further, due to the homogeneity of the amorphous material, the brazing material has extremely excellent characteristics such as melting, permeation, and fusion.

As a method for producing such an amorphous metal foil, a rapid solidification method using a single roll is well known. That is, from the nozzle of the container containing the molten metal, is a method of ejecting the molten metal to the surface of the roll rotating at high speed to rapidly cool and solidify on the surface, but at this time, the molten metal colliding with the surface of the roll is The roll surface is held for the time required for solidification so as not to be blown off by centrifugal force, forming an amorphous and uniform continuous strip-shaped foil, and this solidified foil is continuously and easily stabilized from the roll surface. It is indispensable to peel it off.

As a method for separating continuous filaments from a cooling roll, Japanese Patent Application Laid-Open No. 52-133826 discloses a method in which a solidified metal filament is solidified when a molten metal flowing out to the inner surface of a rotating cooling roll exceeds a solidification point. A method is disclosed in which a gas jet is blown from the inner surface of the cooling roll and lifted up, or a metal knife is used for peeling.

[0007]

The peeling means using a gas jet, a metal knife, etc. disclosed in the above publication is easy and easy to adopt. However, the Au-based alloy foil obtained by rapid solidification by the single roll method is used. In the case of producing, the foil solidified on the roll surface could not be peeled off well from the roll surface, and it was difficult to obtain a good foil. That is, in the Cu roll which is usually used in the single roll method, the solidified foil is wound around the roll during casting, and the foil is conveyed to the pouring point without being peeled off, so that the pouring cannot be completed.

[0008] The present invention has been made in order to solve the problems in the present situation in the production of amorphous Au-based alloy foil.
It is an object of the present invention to provide a method for easily peeling a solidified foil produced by a single roll rapid solidification method from a cooling roll by focusing on wettability between an Au-based alloy and a roll and selecting a roll material.

[0009]

In order to achieve the above object, the present invention is a method for producing a thin film amorphous foil strip by jetting a molten metal of an Au-based alloy onto the surface of a single roll rotating at a high speed and quenching and solidifying the molten metal. In addition, at least the surface of the single roll is made of an aluminum-based material. As the above-mentioned Au-based alloy, Au-Sn, Au-
There are Si, Au-Ge, etc., and any one of them can be selected. In particular, when a thin film amorphous foil strip is formed from an alloy of Sn: 20% by weight and the balance substantially Au,
Suitable as a brazing material.

The present invention will be described in detail below. When continuously casting an Au-based alloy foil strip as a thin film such as a brazing material by a single-roll rapid solidification method, the cooling roll used must have the thermal conductivity required to amorphize the alloy foil. Further, it is possible to form a continuous shape of the alloy foil, and uniform cooling is compensated so that the surface roughness is sufficiently smooth, and the roll material metal adhered to the alloy foil is used as a brazing material. It is necessary to render it harmless or at a level less than the harmless level, and in addition to this, it is important that it does not surface-attach to the cooling roll due to alloying with the alloy or seizure.

The present inventors examined various materials for cooling rolls satisfying the above conditions when casting the Au-based alloy foil strip. That is, Fe-based roll, Cu-based roll, Cu + N
i-plated roll, Cu + Ag plated roll and A
When casting was attempted for an l-based roll, it was confirmed that an Au-based amorphous alloy foil could be obtained by appropriately selecting the casting conditions regardless of which material roll was used. However, in most of the rolls described above, the alloy foil undergoes strong wrapping around the cooling roll surface during casting, and it is difficult to separate from the roll surface even by the conventionally used peeling means, so that pouring is not possible. I couldn't finish it, but A
Only the l-type roll could be easily peeled off.

Based on such an experiment, the present invention amorphizes an Au-based alloy, particularly an Au-Sn alloy, as a brazing material used for electronic devices and the like. Therefore, in the production of foil by the single roll rapid solidification method, It has been found that applying an Al-based material as a cooling roll is industrially optimal. A roll using an Al-based material has not been conventionally used in the single roll rapid solidification method because of the problem of its own melting point, but since an Au-based alloy, particularly an Au-Sn amorphous alloy, has a lower melting point than Al, Enables the production of continuous foil strips by solidification. Although the releasability of this Al roll is not clear, an extremely thin oxide film (Al ₂ O ₃ ) with a high melting point is formed on the polished roll surface according to the investigation of the present inventors. It is considered that the covering controls the wetting and has an effect of promoting the peeling of the cast foil strip from the roll surface.

The aluminum or Al-based roll (material) used in the present invention means a material containing Al as a main component (pure Al).
Alternatively, an Al alloy containing 5% or less of Fe, Cu, Mg, etc. in total is used for Al, and pure Al is particularly preferable, and rolls are formed from these materials, or at least the surface portion of the roll is constituted.

[0014]

EXAMPLE An alloy consisting of Sn: 20% and the balance Au was melted to 300 ° C. in a crucible, and then the molten alloy was jetted from a nozzle at the tip of the crucible onto a cooling single roll rotating at a high speed, and a continuous rapidly solidified foil of 5 mm in width An experiment for casting was performed. The cooling roll had a diameter of 300 mm and a width of 30 to 5 which was surface-polished under the same conditions.
0mm Fe, Cu, Cu base material with Ni plating and Al
The peeling condition of the coagulated foil was observed using the rolls of the respective materials.

FIG. 1 shows the state of winding of the Au-Sn alloy solidified foil on the roll surface when pouring a single roll in relation to the roll peripheral speed for each roll material. In the figure, the vertical axis is involved (S)
Shows the occurrence of entrainment from the early stage of casting, (M) shows the middle stage of casting, and (E) shows the latter stage of casting, and (No) shows complete entrainment with no entrainment. As is clear from the figure, in Fe rolls, Cu rolls, and Cu + Ni plated rolls, wrapping of the solidified foil occurs around the roll surface regardless of the roll peripheral speed, making continuous casting operations impossible. On the other hand, in the Al roll, it can be seen that roll surface winding does not occur in the region where the roll peripheral speed is 15 m / sec or less. That is, by using an Al roll,
The Au-Sn alloy solidified foil could be easily peeled from the roll surface, and an amorphous continuous uniform foil having a width of 5 mm could be obtained.

[0016]

As described above, according to the present invention, an Au-based amorphous alloy foil can be industrially produced continuously by a single roll rapid solidification method with a good yield, and is suitable for a thin film material such as a brazing material. Can be provided as an excellent material.

[Brief description of drawings]

FIG. 1 is a diagram showing a roll surface winding behavior of an Au—Sn alloy solidified foil when pouring a single roll for each roll material.

Continuation of the front page (72) Inventor Hiroshi Iida 1-1, Toibata-cho, Tobata-ku, Kitakyushu, Fukuoka New Nippon Steel Corporation Yawata Works

Claims (3)

[Claims] 1. A method for producing a thin film amorphous foil strip by jetting a molten metal of an Au-based alloy onto the surface of a single roll rotating at a high speed and rapidly solidifying the molten metal, wherein at least the surface of the single roll is made of aluminum. Method for peeling rapidly solidified foil in single roll method. 2. The Au-based alloy is Au-Sn, Au-S.
The peeling method for a rapidly solidified foil in the single roll method according to claim 1, wherein the peeling method is any one of i and Au-Ge. 3. The method for stripping a rapidly solidified foil in a single roll method according to claim 1, wherein the thin film amorphous foil strip is a brazing material consisting of Sn: 20% by weight and the balance substantially Au.