JPH054183B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a method of manufacturing a clad strip material used for connectors, switches, relays, and lead frames for integrated circuits. (Prior art and its problems) Conventionally, when a band-shaped metal material such as stainless steel, phosphor bronze, or nickel silver is used for a connector, switch, relay, lead frame, etc., the band-shaped metal material is coated with a band of precious metal or precious metal alloy in advance. Either the composite strip material with the materials joined is punched out using a press, and then the terminals are electrically soldered before being assembled, or the composite strip material is punched out using a press and then molded, and then electrical Sn or electrical solder is applied. It is assembled after soldering. By the way, these methods tend to cause the solder to peel off into powder during the next assembly process, and tend to contaminate the precious metal or precious metal alloy. Electric soldering surfaces tend to crack during bending, etc., resulting in poor adhesion. Residual stress during electrical soldering causes distortion in the base material. Electrical soldering requires a large number of man-hours, especially for molded products, etc., which requires work such as racking for energization. The work process is complex and difficult to serialize and automate. There were other problems. On the other hand, attempts have been made to use a composite strip material made by bonding strips of noble metals or noble metal alloys and electroplating them with Sn, but the problem is that Sn tends to generate whiskers, and alloy electroplating is difficult. Problems include the fact that the component ratio tends to vary, making it difficult to obtain accurate plating with stable components, and composite strip materials soldered with electric solder have poor press workability and short mold life. Due to this problem, it is rarely put into practical use. (Purpose of the invention) The present invention was made to solve the above-mentioned problems, and has good solder adhesion and does not peel off even during cutting, bending, etc., does not stain the noble metal or noble metal alloy surface, and does not cause strain on the band-shaped metal material. It is an object of the present invention to provide a method that can continuously and automatically manufacture a composite strip-shaped material without causing any problems, with a simple work process, and with a simple process. (Structure of the Invention) The method for producing a composite strip-shaped material of the present invention is to produce a composite strip-shaped material that is press-worked using phosphor bronze, nickel silver, beryllium copper, other copper alloys, or Fe-
Au, Ag, Pd,
After joining the band-shaped material of noble metal such as Pt or precious metal alloy thereof, in the longitudinal direction of one end of the band-shaped metal material where the noble metal or precious metal alloy is not joined,
The method is characterized in that the solder is immersed in a bath containing molten solder and moved while being covered with molten solder. (Example) An example of the method for manufacturing a composite strip material of the present invention will be described with reference to the drawings. Thickness 0.7 as shown in Figure 1
As shown in FIG.
Band-shaped materials 2 made of Au with a width of 2.0 mm are joined and further cold-rolled to obtain a composite strip with a thickness of 0.25 mm for the metal strip 1 and a thickness of 0.002 mm for the strip 2, as shown in Fig. 3. I made 3. Next, the composite strip 3 is passed through a slit provided in a tank in which 65% Sn-35% Pb solder is melted, and one end is dipped in the molten solder in the tank while being moved to cover it with molten solder. As shown in FIG. 4, a composite strip-shaped material 3' having a solder layer 4 having a thickness of 1 μm and a width of 6 mm provided at one end thereof was manufactured. When the band-shaped metal material 1 of this composite band-shaped material 3' was inspected, there was no distortion, and when the thickness of the solder layer 4 was measured using a Beta scope (film thickness measuring device), the results shown in the table below were obtained. .

[Table] Next, this composite strip-shaped material 3' was cut into a length of 50 mm, a 180-degree bending test was performed with an inner radius of 0.2 mm, and the surface of the solder layer 4 was magnified 20 times with a microscope and observed. As a result, no cracks, peeling, etc. were observed, and it was confirmed that the plastic deformation of the solder layer 4 could sufficiently correspond to the deformation of the surface of the strip-shaped metal material 1. In addition, as a result of observing the cut surface with a scanning electron microscope at a magnification of 50 times, no defects such as peeling or chipping were observed on the cut surface, but rather some solder had soaked into the cut surface, and the Au It was confirmed that there was less solder powder that contaminated the surface. Furthermore, as a result of EPMA analysis of the surface of the Au strip material 2, no elements such as Pb or Sn were detected on the surface, confirming that there was no risk of contamination by solder. Therefore, the composite strip material 3' shown in FIG.
For example, as shown in FIG. 5, when a connector contact 5 is manufactured by punching, cutting, etc.,
A product of good quality and no problems was obtained. Note that the solder coating is not limited to one end of the band-shaped metal material where the noble metal or noble metal alloy is not joined, but may be applied to both ends. (Effects of the Invention) As can be seen from the above explanation, according to the manufacturing method of the composite strip material of the present invention, since it is coated with molten solder, the adhesion of the solder can be improved, and it is possible to perform cutting, bending, etc. The effect is that it does not peel off even when rubbed, does not stain the precious metal or precious metal alloy surface, does not cause distortion in the band-shaped metal material, and simplifies the work process so that high-quality composite materials can be manufactured continuously and automatically and efficiently. .

[Brief explanation of the drawing]

1 to 4 are process diagrams showing one embodiment of the method for manufacturing a composite strip-shaped material of the present invention, and FIG. 5 is a perspective view of a contact for a connector made from the composite strip-shaped material of FIG. 4.

Claims (1)

[Claims] 1. In the composite band-shaped material to be pressed, after joining a band-shaped material of noble metal or precious metal alloy such as Au, Ag, Pd, or Pt in the longitudinal direction of the surface of the band-shaped metal material of copper-based alloy or iron-based alloy, the band-shaped metal material is A method for producing a composite band-shaped material, which comprises immersing one end of a material of a precious metal or a precious metal alloy in a longitudinal direction in which one side is not bonded into a bath containing molten solder and moving the material to cover it with molten solder. .