JPH10237687A - Stripe plating method for long-sized metallic bar - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the rise of a solder plating liquid by capillarity and to execute stripe plating with high accuracy and high quality by subjecting long- sized metallic bars to ground surface Ni plating, then to a gold plating treatment in a longitudinal direction and applying a capillarity phenomenon preventive treating liquid on the gold plating regions, then subjecting the bars to solder plating. SOLUTION: The long-seized terminal metallic bars 1 consisting of bronze, etc., connected to many terminals 3 in carrier parts at intervals (G) of about 0.3mm are obtd. by press forming. The metallic bars 1 are continuously supplied to a plating treating device via the carrier parts 2 and are subjected to the ground surface Ni plating and, thereafter, the contact parts 4 of the terminals 3 are subjected to gold plating to a stripe form in the longitudinal direction. The capillarity phenomenon preventive treating liquid is applied on the bars to cover these gold plating regions LA. The metallic bars 1 are thereafter inverted and the junctures 5 thereof are subjected to solder plating. The capillarity phenomenon preventive treating liquid is preferably a sealing treating liquid of an aq. soln. contg. inhibitors of a benzotriazole-base compd., etc., lubricants of fatty acid and emulsifiers of monoalkyl phosphate, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to long metal strips used for various terminals, such as connectors, which are connection parts for electrical equipment, and lead materials, such as IC lead frames, which are plated with gold, solder, or the like. And a plating method.

[0002]

2. Description of the Related Art Conventionally, in order to manufacture various terminals such as connectors, which are connection parts for electric equipment, or lead materials such as IC lead frames, copper alloys such as brass and phosphor bronze for springs are used. The long metal strip is press-formed to form continuous male and female terminals.

FIG. 2 shows an example of a long metal strip 1 for manufacturing various terminals such as a connector which is a connection part for an electric device.
Has a carrier portion 2 which is continuous in the longitudinal direction, and terminals 3 are connected to the carrier portion 2 at a predetermined interval (G) so as to be separated from each other. Such a long metal strip 1 formed by press forming is continuously supplied to the plating equipment by the carrier unit 2 being driven by engagement with a driving device.
After plating the long metal strip 1 with Ni or Pd-Ni or the like (hereinafter, simply referred to as “base Ni plating”), the long metal strip 1 is striped in the longitudinal direction, that is, the terminal tip, that is, the length L _a region in the contact portion 4 gold or gold - plating, such as cobalt alloy (simply referred to as "gold-plating".)
However, solder plating is applied to the carrier portion side of the terminal 3, that is, the connection portion 5 in the region of the length L _S including the carrier portion 2.

[0004] A brief description of such a striped plating method is as follows. The long metal strip 1 on which the terminals 3 are press-formed as shown in FIG. 2 is first subjected to a base Ni plating in a Ni plating tank. . After the washing process, the long metal strip 1 is conveyed with the carrier portion 2 positioned upward, and the contact portion 4 of the long metal strip 1 is gold-plated in a gold plating tank. Next, after the water washing process, the long metal strip 1 is inverted so that the carrier part 2 is located below, and is conveyed to a solder plating tank, and the connection part 5 and the carrier part 2 are subjected to solder plating. After the solder plating, a sealing process is performed after performing a water washing process or the like. The sealing treatment is a treatment for sealing a pinhole generated in the coating layer when the gold plating thickness is reduced,
Various organic or inorganic chemicals are used for the sealing treatment.

[0005]

The present inventors have conducted many research experiments on the above plating method, and as a result, FIG.
As shown in, solder plating area (L _S), despite the gold plated region (L _A) is set spaced apart by L _G, will solder plating adheres to the gold-plated region, It turned out that there was a problem in quality.

The present inventors have investigated the cause to solve this problem, and found that the distance (G) between the terminals 3 formed on the long metal strip 1 is, for example, 0.3 mm. because it is an extremely narrow such hereinafter, by capillary action when performing solder plating, solder plating solution rises through the gap (G) between the terminals 3 and 3, the gold-plated region (L _a) This is because solder plating is also performed.

Therefore, an object of the present invention is to prevent the solder from adhering to the gold plating area by preventing the solder plating solution from rising due to the capillary phenomenon in the solder plating step.
An object of the present invention is to provide a long metal strip plating method capable of performing high-precision and high-quality strip plating of gold, solder, or the like on a long metal strip.

[0008]

The above objects can be attained by a long metal strip plating method according to the present invention. In summary, the present invention is to continuously supply a long metal strip formed in a predetermined shape, to perform Ni plating on the metal strip, and then to perform gold plating in a stripe shape in the longitudinal direction of the metal strip. And in the long metal strip stripe plating method of performing solder plating, after the gold plating treatment, applying a capillary phenomenon preventing treatment liquid covering the gold plating area of the metal strip, and thereafter, performing the solder plating. Long metal strip plating method. Preferably, after the solder plating process, at least a gold plating region of the metal strip is subjected to a sealing process.

According to a preferred embodiment of the present invention, the capillary action preventing solution is a sealing solution. The sealing treatment liquid contains one or more of a benzotriazole-based compound, a mercaptobenzothiazole-based compound, and a triazine-based compound as an inhibitor, and one or more fatty acids as a lubricant.
It is an aqueous solution containing one or more kinds of monoalkyl phosphates and one or more kinds of dialkyl phosphates as emulsifiers.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The long metal strip plating method according to the present invention will be described in more detail with reference to the drawings.

FIG. 1 shows a schematic configuration of an embodiment of a plating facility for performing a long metal strip plating method of the present invention. In the plating equipment of the present embodiment, it is assumed that the long metal strip 1 for manufacturing the terminal of the connector, which is a connection part for an electric device as shown in FIG. 2, is subjected to gold plating and solder plating.

The metal strip 1 for the connector terminal shown in FIG.
As described above, for example, a thickness of 0.2 mm and a width (W) of 25
A long metal strip made of a copper alloy such as phosphor bronze for springs having a length of 1 mm is used, and the long metal strip 1 is formed by press forming. Molded terminal metal strip 1
Has a shape in which terminals 3 are connected to a continuous carrier portion 2 at a predetermined interval (G). In this embodiment, the distance (G) between the terminals 3 is set to 0.3 mm,
Length (L _C) is 13 mm, the width of the terminal 3 (w) is 0.6
mm.

In FIG. 1, a long terminal metal strip 1 formed by such press forming is driven by a carrier 2 engaged with a driving device (not shown) and continuously supplied to a plating facility. You. At this time, the terminal metal strip 1 is conveyed so that the carrier part 2 is located above. In this example, the transfer speed of the terminal metal strip 1 was set to 2 m / min.

First, the terminal metal strip 1 is placed in a Ni plating tank 10.
Is subjected to a Ni base plating process. For example, the terminal metal strip 1 plated with a Ni undercoat to a thickness of 1.27 μm in a Ni plating tank 10 is subjected to a water-washing treatment in a water-washing treatment tank (not shown), and is conveyed while the carrier unit 2 is positioned upward.
It is transported to the gold plating tank 20. In this embodiment, three gold plating tanks 20 are arranged, but the present invention is not limited to this. In each of the gold plating tanks 20, the terminal metal strip 1 has a terminal tip portion, that is, a contact portion 4, which has a thickness of 0 mm over a length L _A = 7.1 mm from the tip in this embodiment. .5μ
At m, gold is plated in a stripe shape in the longitudinal direction. Next, the terminal metal strip 1 is subjected to a water washing treatment in a water washing treatment tank (not shown), and is conveyed to the capillary phenomenon prevention treatment tank 30.

FIG. 3 shows an embodiment of the capillary action preventing treatment tank 30. According to the present embodiment, the capillary phenomenon prevention treatment tank 30 has an inner cell 31 and an outer cell 32, and the inner cell 31 has a box-like shape that is open at the top and can accommodate a treatment liquid therein. . The front and rear walls 33 and 34 of the inner cell 31 are continuously connected to the inner cell 31.
An inlet opening 35 and an outlet opening 36 are formed for the terminal metal strip 1 to be supplied therein to pass therethrough. In the present embodiment, the inlet opening 35 and the outlet opening 36
Is formed as a separate member from the front and rear wall portions 33 and 34 of the inner cell 31. That is, the inlet opening member 37 and the outlet opening member 38 are provided, and the concave grooves 37A and 38A are formed on both sides of each member. Each of the members 37, 38 uses the concave grooves 37A, 38A to form the front and rear wall portions 33,
The front and rear walls 3 of the inner cell 31 are fitted into the U-shaped openings 33A and 34A formed in the inner cell 31.
It is configured to be attachable to and detachable from 3, 34.

The side walls 39, 40 of the inner cell 31 are formed with concave notches 39A, 40A.
The processing liquid supplied into the inner cell 31 flows out through the inlet opening 35 and the outlet opening 36, and overflows the notches 39A and 40A. That is, the liquid level in the inner cell 31 is defined by the height of the notch and is always kept constant.

Further, according to this embodiment, the inner cell 3
In order to adjust the liquid level in the liquid crystal 1, the liquid level adjusting means 50 is used.
Is provided. The liquid level adjusting means 50 is provided with the notch 39
3A shows the entire liquid level adjusting means 50 provided on the side wall 39 on the front side. The liquid level adjusting means 50 is provided with the notches 39A and 40A.
And a guide member 5 fixed to the side walls 39 and 40 to guide the liquid level adjusting member 51 slidably up and down.
And 2. The liquid level adjusting member 51 includes a nut member 53 protruding outward, and a screw portion 55A of an adjusting screw 55 rotatably attached to a support plate 54 fixed to the upper surface of the inner cell 31 is screwed. doing. Therefore, by turning the knob of the adjusting screw 55, the liquid level adjusting member 51 can be moved in the vertical direction, and the liquid level of the inner cell 31 can be adjusted.

The processing liquid overflowing from the inner cell 31 is received in the outer cell 32 located below the inner cell 31, and the processing liquid in the outer cell 32 is circulated by a circulating device (not shown) such as a pump. Cell 3
Refluxed to 1.

With the above configuration, the capillary action preventing treatment tank 3
Terminal metal strip 1 supplied into the inner cell 31
The processing liquid is applied with high precision up to a predetermined height, that is, up to the gold-plated height.

The capillarity prevention treatment tank 30 may have a structure designed to be longer in the longitudinal direction as desired, for example, as shown in FIG. In this case, the notches in the side wall portion where the processing liquid overflows can be increased, and the liquid level adjusting means 50 can be provided for each notch.

The treatment solution used in the present invention functions to prevent the solder plating solution from rising in the gap (G) between the terminals 3 and 3 due to the capillary phenomenon in the subsequent solder plating treatment. Anything can be used if present.

According to the results of the research conducted by the present inventors, various organic or inorganic sealing liquids conventionally used for sealing can be preferably used. I understood. For example, as a sealing treatment liquid, JP-A-8-2
JP-A-60192, JP-A-8-260193, JP-A-8-260194, etc. (1) One or two types of benzotriazole-based compounds, mercaptobenzothiazole-based compounds, and triazine-based compounds as inhibitors Above, 0.001 to 1 wt% in total (2) One or more fatty acids as lubricant, 0.05 to 2 wt% in total
% (3) As an emulsifier, there is an aqueous solution containing one or two or more monoalkyl phosphate dialkyl phosphates in a total amount of 0.05 to 2% by weight, and these sealing treatment solutions are suitable as capillary action prevention treatment solutions. Can be used for

In this embodiment, an aqueous solution consisting of benzotriazole (0.01% by weight) as an inhibitor, oleic acid (0.3% by weight) as a lubricant, and monoester of lauric acid monoester (0.3% by weight) as an emulsifier is used as a capillary. It was supplied to the inner cell 31 of the phenomenon prevention treatment tank 30 and maintained at a temperature of 40 to 80 ° C.

The terminal metal strip 1 gold-plated on the striped strip as described above is guided into the inner cell 31 of the capillary action preventing treatment tank 30 in which the above-mentioned capillary action preventing treatment liquid is stored at a constant liquid level. , by immersing in a treatment solution, to a height which is gold-plated, i.e., the treatment liquid is applied over the gold plated L _a region in FIG. 2. Preferably,
Treatment liquid, 5 to 6 m in slightly above the gold plating L _A region
about m, i.e., gold plated region (L _A) between the solder region (L
_G ) and a boundary region (L
_G ) is applied until it reaches It is better not to apply to the solder area L _S.

Thereafter, the terminal metal strip 1 is dried by a drying device (not shown) as shown in FIG. 1, and then inverted by an inverting device 60 so that the carrier portion 2 is located below. It is transported to the solder plating tank 70. Solder plating tank 7
In the case of 0, solder plating is applied to the carrier portion side of the terminal 3, that is, in FIG. 2, the length L _S region including the connection portion 5 and the carrier portion 2.

According to this embodiment, since the capillary phenomenon preventing treatment is performed as described above, the plating solution (electrolyte) in the solder plating tank 70 causes the gap (G) between the terminals 3 and 3 to be reduced by the capillary phenomenon. rises and is prevented from penetrating into the gold plating zone L _a, as a result, solder gold plating layer of the contact portion 4 is able to completely prevent the deposition.

After the above-mentioned solder plating process, the substrate is subjected to a washing process or the like, and then supplied to a sealing bath (not shown). At least a gold plating region is formed to seal a pinhole formed in the gold plating layer. (L _a) is immersed in the sealing treatment solution, performing sealing treatment by electrolysis. For the sealing treatment, various organic or inorganic treatment liquids known to those skilled in the art are used. In this example, the same processing liquid as the processing liquid used in the above-mentioned capillary phenomenon prevention processing tank was used.

From the terminal metal strip 1 thus manufactured, the terminal 3 is cut from the carrier portion 2 to manufacture a connector.
Electrical tests, corrosion tests, etc. were performed. Contact resistance is 10
mΩ or less, good corrosion resistance, and good results could be obtained.

[0029]

As described above, according to the method of strip plating of a long metal strip of the present invention, a long metal strip formed in a predetermined shape is continuously supplied, and the metal Ni is plated on the metal strip.
In a long metal strip stripe plating method of plating and then performing striped gold plating and solder plating in the longitudinal direction of the metal strip, the gold plating treatment covers the gold plating area of the metal strip and prevents capillary action. Is applied and then solder plating is performed, so that it is possible to prevent the solder plating solution from rising due to the capillary phenomenon in the solder plating process, thus preventing the solder from adhering to the gold plating area. In addition, strip plating of gold, solder, or the like can be performed on the long metal strip with high precision and high quality.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a plating facility for performing a long metal strip plating method of the present invention.

FIG. 2 is a front view showing one embodiment of a long metal strip.

FIG. 3 is a perspective view of an embodiment of a capillary phenomenon prevention treatment tank for performing a capillary phenomenon prevention treatment step.

FIG. 4 is a perspective view of another embodiment of a capillary phenomenon prevention treatment tank for performing a capillary phenomenon prevention treatment step.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Long metal strip 2 Carrier part 3 Terminal 4 Contact part 5 Connection part 6 Notch 30 Capillary phenomenon prevention treatment tank 31 Inner cell 32 Outer cell 50 Liquid level adjusting means

Claims (4)

[Claims] 1. A long metal strip formed in a predetermined shape is continuously supplied, the metal strip is plated with Ni, and then a striped gold plating and a solder plating are formed in the longitudinal direction of the metal strip. A long metal strip stripe plating method, wherein after the gold plating treatment, a capillary action preventing treatment liquid is applied so as to cover a gold plating region of the metal strip, and thereafter, the solder plating is performed. Metal strip plating method. 2. A long metal strip stripe plating method according to claim 1, wherein a sealing process is performed on at least a gold plating region of the metal strip after the solder plating process. 3. The long metal strip plating method according to claim 1, wherein the capillary action preventing treatment liquid is a sealing treatment liquid. 4. The pore-sealing treatment liquid comprises one or more of a benzotriazole-based compound, a mercaptobenzothiazole-based compound, and a triazine-based compound as an inhibitor, one or more of a fatty acid as a lubricant, and an emulsifier. 4. A long metal strip plating method according to claim 3, which is an aqueous solution containing one or more of a monoalkyl phosphate and a dialkyl phosphate.