JPS59110792A - Preventing method of easily soluble alloy for plating electrode from coming off - Google Patents

Abstract

PURPOSE:To secure stably an easily soluble alloy which has been used as a contact plating electrode sticking to the contact member surface and will otherwise cause trouble in an assembling step afterwards if not secured on a contact member surface, by immersing the contact member in a warm water bath to remove the easily soluble alloy, and then vibrating the remaining easily soluble alloy in a dilute oxalic acid solution by ultrasonic waves. CONSTITUTION:For example, after contact plating treatment of a lead piece 1 of a contact member such as a lead switch, the lead piece terminal section 7 opposite to a contact section 6 has an easily soluble alloy (shown as a shaded area in the figure) sticking thereto. For example, in case this electrode connecting easily soluble alloy is a low-melting alloy that has a composition of Pb-Zn-In and will melt at 70-80 deg.C, the lead piece 1 is immersed in warm water at least at 80 deg.C so that the alloy on the terminal surface becomes a free state. Then vibrations are applied by an ultrasonic vibrator to make the terminal surface smooth. Thereafter, the easily soluble alloy that has not been removed is vibrated in a dilute oxalic acid solution having a concentration on the order of 0.5-10wt% at the same temperature by the same ultrasonic vibrator. Thus the solder remaining on the surface is secured effectively.

Description

[Detailed description of the invention] (a) Technical field of the invention The present invention relates to a method for preventing detachment of easily soluble alloys for plating electrodes.

(b) Background of the technology Contact members that have undergone basic forming such as press molding (for example, reed switch reed pieces) are plated with a precious metal such as gold or rhodium to ensure contact stability. Get features. However, during plating, it is desirable to ensure the connection between the plating electrode and the contact member, to make the plating current flowing through the contact member uniform, and to simplify the electrode attachment of the contact member. That is, in order to obtain uniform contact performance with little variation in plating thickness and to increase the productivity of plating, connection is performed using an electrode jig made of easily meltable alloy.

After the contact plating has been completed, the contact member is assembled into a switch, but it is necessary to peel off or remove the easily fusible alloy attached to the connection part with the plated electrode, and if this removal is incomplete, subsequent contact will be prevented. This will hinder the assembly of parts.

The present invention proposes specific means for peeling off the easily soluble alloy adhering to the surface of a contact member and fixing the surface after the peeling based on the above-mentioned requirements.

(C) Problems with the Prior Art As an example of the contact member, FIG. 1 shows a side view of the lead taken up and mounted on a plating jig.

In the figure, 1 is a lead piece, 2 is a plated electrode hardened with a flat plate-shaped easily meltable alloy, 3 is an electrolytic plating bath, 4 is a guide plate for the lead piece, and 5 is a leg of the jig. be. or,
6 is a contact portion of the lead piece, and 7 is a lead piece terminal portion on the opposite side from the contact portion 6, which is fitted into a chuck mechanism of a switch assembly machine.

By the way, the easily fusible alloy that adheres to the surface of the contact-plated lead piece terminal (Figure 2 is a perspective view of the lead piece before assembly, and the shaded area in the figure is the target area) is easily separated, especially when assembling the switch. This is a serious inconvenience as it separates from the surface and becomes particulates which become enclosed within the switch.

(d) Purpose of the invention The present invention is to solve the above problems.

That is, the purpose is to stably fix the easily soluble alloy on the surface of the contact member, which would be a hindrance in the subsequent assembly process.

(e) Structure of the Invention The above object is to immerse the contact member in a hot water bath to peel off the adhering easily soluble alloy, and then remove the easily soluble alloy adhering to the surface of the contact member by ultrasonic vibration in a diluted oxalic acid solution. This is achieved by fixation.

(f'') As the easily soluble alloy for the embodiment of the invention, Pb-Zn-Tn silk 70~
There is a low melting alloy that melts at 80°C.

According to the present invention, when removing the easily soluble alloy for connecting plated electrodes, the alloy on the terminal surface is removed by immersing the contact member in salt water of at least 80°C, since the alloy body attached to the surface has a low melting point. The body is brought to a free δ11 state, and at this time, it is shaken using a sonic exciter used for degreasing and cleaning, etc., to remove most of the alloy body attached to the terminal portion into the water. Smooth the terminal surface by so-called weeping.

Next, the easily soluble alloy on the surface that has not been completely separated is shaken by ultrasonic vibration in the same manner as described above in a diluted oxalic acid solution (diluted solution with a weight ratio of about 0.5 to 10%) at the above temperature.

The latter vibration in the oxalic acid diluted solution is effective for fixing the solder remaining on the surface of the terminal etc. of the contact member.

If the above-mentioned treatment is applied to the reed pieces shown in the two examples (Fig. 2), it will be easier to later attach the reeds.

This eliminates the possibility of harmful foreign matter being enclosed in the switch at the contact point where easily melted alloy powder is scattered from the terminal surface, which was the second problem during assembly.

However, the embodiments described above are not limited to reed switches. The present invention may also be applied to processing of similar contact members, for example, where contact function is emphasized and productivity is increased.

(g) Preventing detachment of easily meltable alloy for plating electrodes of the present invention in detailed description of the invention 11-
This method is extremely effective in improving the productivity of this type of parts when used in conjunction with contact plating treatment in the previous process. From this point of view, the present invention has great practical value.

[Brief explanation of the drawing]

FIG. 1 is a simplified side view of the structure of a plated electrode body made of an easily meltable alloy, which is the object of the present invention. FIG. 2 is a perspective view of a plated contact member. In the figure, 7 is the terminal portion to which the easily melted alloy is attached. 1st mouth

Claims (1)

[Claims] In a method for preventing detachment of the easily soluble alloy used as a contact plating electrode that adheres to the surface of a contact member, the attached easily soluble alloy is peeled off by immersing the contact member in a hot water bath, and then ultrasonically applied in a diluted oxalic acid solution. A method for preventing detachment of easily soluble alloys for plating electrodes, which is characterized by fixing easily soluble alloys adhering to the surface of contact members by vibration.