JPS63203777A - Partial mechanical plating method - Google Patents

Abstract

PURPOSE:To subject the surface of a material to be plated to partial mechanical plating with an extremely simple means by bringing a metallic brush tufted with many pure metal or alloy materials into contact with the surface of the material to be plated by interposing a masking material having a desired shape therebetween. CONSTITUTION:A stationary masking material 3 having a band-shaped through- hole 5 is pressed to the surface of the material 4 to be plated and the wire brush 1 consisting of wires 2 of the pure metal or alloy is brought into contact with said surface and is rubbed thereto in the figure (a). A band-shaped plating layer 5 is thereby formed on the surface of the material 4 through the band- shaped through-hole 5 as shown in the figures (b), (c). The wire brush 1 may be of a ribbon or tape shape. Intermittent partial plating which is heterofore impossible to be formed by the conventional cold rolling cladding method is formable in the longitudinal direction of the band when the plating layer is provided to the lead wire soldering part of a lead frame stock in particular according to the method of this invention.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention is applicable to partial mechanical plating in fields where corrosion resistance, heat resistance, abrasion resistance, solderability, conductivity, plating performance, decorativeness, etc. are required. Regarding the method.

(Conventional technology) Surface treatment techniques commonly used to plate metal parts on materials include electroplating, chemical plating, hot-dip plating, and thermal spray plating.
A thin film of metal is plated onto the surface of the material and is used for various purposes.

Electroplating is a method of forming a thin metal film on the surface of a material by using a material to be plated as a cathode in a solution containing metal and passing a direct current between the anode and the opposing anode. Chemical plating is a method of plating on nonconducting materials such as glass and synthetic resin without using electricity. Hot-dip plating is a method of plating by dipping into molten metal.

Thermal spray plating is a method of spraying metal melted by gas or arc onto the surface of a material using high-pressure gas or air.

(Problems to be solved by the invention) Among the various plating methods mentioned above, the electroplating method has difficulties in plating one alloy, the chemical plating method cannot produce a thick plating layer and the cost of chemicals is high, and The plating method is
It has the advantage of being able to thicken the plating layer on the inner surface of a pipe simply by dipping it, but it has the disadvantages of being difficult to adjust the thickness, thermal spray plating tends to be porous, and the metal particles are oxidized. The most common problems are that the adhesion between the plating layer and the material is not necessarily sufficient and that the equipment is expensive.

The present inventors previously invented a mechanical plating method as a means to solve these problems (Japanese Patent Application No. 61-1
No. 07764), for example, the joints with lead wires of lead frame materials used in semiconductor devices and semiconductor integrated circuits, or decorative parts of materials such as building materials made of pure metals or alloys, etc.
The present invention was completed based on the new finding that applying a mechanical plating method when plating is performed partially is extremely advantageous compared to other plating methods.

(Means for solving the problem) That is, the present invention brings a metal brush in which a large number of pure metals or alloys made of wires, ribbons, or tapes are planted into contact with the surface of the material to be plated, and connects the metal brush to the surface of the material to be plated. In a method of mechanically plating pure metal or alloy of a metal brush on the surface of a material to be plated by moving the plating material relative to the material,
This is a partial mechanical plating method characterized by partially plating the surface of a material to be plated by interposing a masking material having a desired shape of apertures between the surface of the material to be plated and a metal brush.

ζ Specifically, metal brushes made of pure metals or alloy wires, ribbons, or tapes such as Zn, Ni, Al, Cu, Ti, alloys thereof, stainless steel, superalloys, etc., and materials to be plated. When mechanically plating the pure metal or alloy of the metal brush on the surface of the material to be plated by moving them relative to each other in the air, non-oxidizing gas, or vacuum at a temperature range of -20 to 300°C, A masking material such as a stainless steel plate or ceramics having excellent abrasion resistance is applied to the surface of the plating material to expose only the portion of the material to be plated. Therefore, the suitable temperature range for plating is -20 to 300°C; at temperatures lower than -20°C, the pure metal or alloy components of the metal brush do not blend with the surface of the material to be plated, forming a plating layer. On the other hand, if the temperature exceeds 300℃, the metal brush will become soft and deformed, making it impossible to obtain a uniform plating layer.Also, the atmosphere should be less oxidizing, and should be in a vacuum or in a non-oxidizing atmosphere. but.

As long as the temperature is relatively low enough to suppress the progress of oxidation, no major problems will occur even if the process is carried out in the atmosphere.

The thickness of the plating layer can be increased by increasing the contact time between the metal brush and the material to be plated, or by increasing the pressing force of the metal brush, but if the plating layer is too thick, there is a possibility of partial peeling. Since it is large, its thickness is generally 50 μm or less.

Next, an embodiment of the partial mechanical plating method of the present invention will be described with reference to FIGS. 1 and 2.

In FIG. 1(a), a fixed masking material 3 having a band-shaped through-hole 5 is applied to the surface of the material to be plated 4, and a wire brush 1 made of pure metal or alloy wire 2 is brought into contact with and rubbed on the surface of the material to be plated. As a result, a strip-shaped plating layer 6 is formed on the surface of the material to be plated 4 through the strip-shaped through holes 5, as shown in FIGS. 1(b) and 1(c).

FIG. 2(a) shows that a belt-shaped masking material 7 with through holes 5 formed in desired portions is used instead of the fixed masking material 3, and is moved in synchronization with the material 4 to be plated.
As shown in Figure (b), a plating layer 6 is formed on the surface of the material to be plated 4 at a portion corresponding to the through hole 5 of the belt-shaped masking material 7.

(Effects of the present invention) As described above, a partial plating layer can be formed by the extremely simple method of using a masking material in a mechanical plating method, and a main plating layer can be formed especially on the part of the lead frame material where the lead wires are soldered. By providing a plating layer by the method of the invention, it is possible to perform partial plating intermittently in the longitudinal direction of the strip, which could not be formed by the conventional cold rolling cladding method. In addition, the cold rolled cladding method requires a large rolling rate during rolling, which causes roll seizure, poor sheet shape, and large edge drops, among other drawbacks, but the present invention solves these drawbacks. Especially when the present invention is applied to partial plating of lead frames, the effect is extremely large.

[Brief explanation of the drawing]

FIG. 1(a) is a side cross-sectional view of an apparatus according to an embodiment of the present invention, which performs partial plating in a band shape using a fixed masking material in the longitudinal direction of a material to be plated, and FIG. Fig. 1(c) is a plan view of the material to be plated which has been partially plated by the apparatus shown in Fig. 1(a), and Fig. 2(a) is a front view of the material shown in Fig. 2(a), which is another embodiment of the method of the present invention. Figure 2(b) is a side cross-sectional view of an apparatus that performs partial plating using a belt-shaped masking material with holes formed in the plated area. FIG. 2 is a plan view of a plated material. 1... Wire brush 2... Wire 3... Fixed masking material 4... Material to be plated 5... Transparent
Hole 6... Plating layer 7... Belt-shaped masking material

Claims (1)

[Claims] 1. A metal brush in which a large number of pure metals or alloys made of wire, ribbon, or tape are planted is brought into contact with the surface of the material to be plated, and the metal brush and the material to be plated are moved relative to each other to touch the surface of the material to be plated. In the method of mechanically plating the pure metal or alloy of the metal brush on the surface of the material to be plated by rubbing the metal brush, a masking material having a through hole of a desired shape is interposed between the surface of the material to be plated and the metal brush. A partial mechanical plating method characterized by partially plating the surface of the material to be plated.