JPS61123461A - Production of partially solder-clad bar - Google Patents

Abstract

PURPOSE:To obtain a partially solder-clad bar which obviates the exfoliation of solder by notching preliminarily the surface to be clad of a copper bar subjected to Ni plating and cladding partially the solder to said surface including the notched part. CONSTITUTION:Ni2 is plated to the copper bar 1 and thereafter the surface 4 to be clad of the bar 10 having the Ni plating is preliminarily notched 5 to expose the bar 1 of the inside having the good adhesiveness to the solder 3. The solder 3 is then partially clad to the bar 10 by rolling by which the desired partially solder-clad bar is obtd. The production of the partially solder- clad bar without the exfoliation of the solder part is thus made possible. The clad bar is used as a lead frame for a diode, transitor, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application 1] The present invention relates to a method of manufacturing a Ni-plated partially solder-clad copper strip used as a lead frame for diodes, transistors, etc.

[Prior Art] In the conventional solder partial cladding method, as shown in FIG. 3, the copper strip 1 is plated with Ni2 and then the solder 3 is directly clad by rolling. Because of poor metallic adhesion, when partially cladding the solder 3, the solder 3 often peels off from the boundary between the solder 3 and Ni, which is a problem.

As a countermeasure, a method has been used in which the part of the N1-plated copper strip to be clad is cut or etched in advance to create a groove corresponding to the clad part, but this method increases the number of work steps and requires post-processing. There was a problem in terms of economic efficiency due to the necessity.

Furthermore, a brushing method is known to improve adhesion when cladding, but this method ends up brushing the areas where Ni plating is required, which is outside the area that should be cladding, so it is difficult to use Ni-plated copper strips. Unfortunately, the brushing method cannot be used when partially cladding is required.

[Problem to be Solved by the Invention J] As described above, the conventional method has problems such as peeling of the solder and high cost.

A first object of the present invention is to provide a solder partial cladding method that solves the problems of the prior art described above and improves adhesion when partially cladding with solder.

A second object of the present invention is to provide a solder partial cladding method that solves the problems of the prior art described above, improves adhesion when partially cladding solder, and prevents misalignment. It is in.

[Means for Solving the Problems] In the first invention, a notch is made in advance on the surface of the Ni-plated copper strip to be clad to expose the inner steel strip that has good adhesion with solder (easily spread). This is where the solder is partially clad.

In the second invention, the solder cladding material is guided to a predetermined position while making a notch, and the internal copper strip exposed by the notch is partially clad with the solder cladding material.

[Example] Fig. 1 is a cross-sectional view of a Ni-plated copper strip for detailed explanation of the first invention, in which a copper strip 1 is plated with Ni2 and then plated with Ni2 in the same manner as in Fig. 3 already explained. As shown in FIG. 1(A), a notch 5 is made in advance on the surface 4 of the Ni-plated steel 10 to be clad to expose the internal copper strip 1 which has good adhesion with the solder 3. As shown in (B), the solder 3 is partially clad by rolling.

FIG. 2 is a perspective view of an apparatus for explaining the second invention in detail, and in the figure, 10 is the above-mentioned Ni-plated copper strip, 11 is a notch guide, and 12 is a round or square shape with low tensile strength. 13 is a solder wire, a solder clad material such as a solder tape or a solder foil, and 13 is a rolling roll. Using the notch guide 11, place the solder clad material 12 in place with low tension while making a notch 5 (see Figure 1) on the surface 4 (see Figure 1) of the plated copper strip 10 to be clad. The solder cladding material 12 is continuously partially clad with a rolling roll 13 on the internal copper strip 1 (see FIG. 1) that is guided and exposed by the notch (see FIG. 1).

[Effect of the invention] In order to find out whether the adhesion has improved, a bending test (9
0° inward bending) and tape beering tests were performed, and the results were poor with the conventional method, but good with the method of the present invention. That is, due to the partial cladding of the solder, the solder did not peel off from the boundary, and the quality and appearance were improved. Furthermore, when partially cladding, the degree of positioning of the cladding material to the copper strip is improved, and it is also possible to prevent displacement of the solder cladding material to be cladded. Furthermore, partially clad N
In the process of hammering and processing a single-plated copper strip, it is possible to solve factors that inhibit solder peeling, falling off, etc.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view of a Ni-plated copper strip according to the first invention, Fig. 2 is a perspective view of a device implementing the second invention, and Fig. 3 is a sectional view of a Ni-plated copper strip to explain the conventional method. FIG. 1: Copper strip, 2: Ni, 3: Solder, 4: Surface to be clad, 5: Notch, 10: Ni-plated copper strip, 11: Spark guide, 12: Solder cladding material, 13:
rolling roll.

Claims (3)

[Claims] (1) In a method for manufacturing a partial solder clad strip in which a strip of copper or copper alloy (hereinafter simply referred to as copper) plated with Ni or Ni alloy (hereinafter simply referred to as copper) is partially clad with solder, the Ni-plated A method for producing a partial solder clad strip, which comprises making a notch in advance on the surface of the copper strip to be clad, and partially cladding the copper strip with solder, including the notch. (2) Continuously guide the solder to a predetermined position while making continuous notches on the surface of the Ni-plated copper strip to be clad, and partially continue the solder including the part exposed by the notches. A method for manufacturing a partial solder clad strip characterized by cladding. (3) Claim 1 or 2, characterized in that the solder cladding material is a solder wire, a solder tape, or a solder foil.
2. Method for manufacturing partial solder cladding strips described in Section 1.