JPS5816623B2 - Printed wiring board terminal plating method and equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a terminal plating method and apparatus for a printed wiring board, and its purpose is to use a masking adhesive tape to mask non-plated areas other than terminal plating. It is characterized in that the terminal portion plating is performed continuously without using it.

The terminals of printed wiring boards are coated with Ni and Au for the purpose of reducing electrical resistance and improving corrosion resistance and wear resistance.
The plating process is applied.

In this case, not only the appearance of the product but also its quality,
The positioning of the boundary line between the non-plated portion and the plated terminal portion has important significance.

Conventionally, this boundary line had to be precisely positioned by skilled workers by applying adhesive tape for masks.

In other words, areas other than the terminals to be plated were partially or completely masked.

However, this pasting process requires skill and precision, and removing it requires a great deal of time and effort, and the adhesive tape must have many properties such as chemical resistance, making it expensive and expensive. The adhesive tape type, which is a consumable item, resulted in high costs.

What should be noted further is that in printed wiring boards that require high-precision electrical circuits, the adhesive remaining on the board after it is peeled off causes a major electrical problem.

From this point of view, there has been a strong demand in the industry for the development of a method for plating terminals of printed wiring that does not require the attachment of adhesive tape.

In order to overcome the drawbacks of the conventional method, the present invention provides a method and apparatus for automatically plating the top end of a printed wiring board without using adhesive tape.

Specifically, a plurality of reference holes are drilled in advance at a predetermined interval from the boundary line between the part to be plated and the part not to be plated on the printed wiring board, and then Then, the distance between the reference pin provided on the reference conveyor and the lower end position of the mask material is configured to be the constant predetermined interval described above, and the reference hole drilled in the printed wiring board is fitted into the reference pin, and the plating apparatus is opened. The problem was solved by supplying

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows the appearance of a printed wiring board (hereinafter simply referred to as board 1) to be plated in the present invention.
In the figure, the two-dot chain line indicates the cutting line when the final product is produced by plating.

The portion of the outer periphery to be cut is hereinafter referred to as the cutting allowance.

A conductive portion C for supplying current to the opening of the terminal portion to be plated is usually provided in the cutting margin A.

Additionally, d indicates the direction of the electrical circuit as a product.

In the conventional adhesive tape method, the position of the boundary line was determined by the worker's naked eye, and the area above the boundary line was covered with adhesive tape, so there was a lack of requirements.

Another way to position the boundary line A-A without using adhesive tape is to place the lower end surface 1' of the substrate 1 on a suitable base (not shown) and slide it. 1
According to the cutting method (for example, shearing) that cuts out the substrate end face 1', the processing accuracy of the substrate end face 1' is ±0.5 to 2M.
In the method described above, which uses the lower end surface 1' as a reference, the length E of the terminal opening to be plated differs for each board, and the distance between the lower end surface 1' and the boundary line A-A also differs depending on the processing accuracy of the board edge. It depends on external factors such as

Therefore, in the present invention, a two-datum hole method is adopted in which the accuracy is not affected by external factors.

The reference hole 2 method is a method in which the reference hole 2 is provided on the hole line B-H, which is a predetermined distance C from the boundary line A-A.

According to this method, plating can be accurately applied to the opening of the terminal portion based on the reference hole 2 (more precisely, the center of the reference pin 3 to be described) and bordering on the boundary line A-A.

Note that in the case of a through-hole wiring board, since several through-holes are drilled in the board 1, if the reference hole 2 is drilled at that time, the amount of work will not increase.

Also, if the reference hole 2 is provided at the cutting margin A, it will not remain when the product is manufactured.

Note that since the reference holes and reference pins are used for positioning purposes, their shapes are not limited to round shapes.

Next, the configuration of the plating apparatus will be explained with reference to FIGS. 2 to 4.

2 is a plan view, FIG. 3 is a side sectional view, and FIG. 4 is an enlarged front view taken along the cutting line XX in FIG. 3.

8 is a plating processing tank and has an anode 9 connected to a power supply device (not shown) inside, and openings 8 are provided at both ends in the longitudinal direction so that the substrate 1 and the mask material 5 can pass through continuously. are doing.

Further, a liquid receiving tank 10 is provided below the opening 8' for receiving the washing liquid from the bath.

Therefore, the plating solution is transferred from the liquid receiving tank 10 to the piping 11 and the pump 1.
2 to the plating tank 8.

Reference numeral 5 designates a masking material for masking a predetermined portion of the substrate 1 from both of them, and in this embodiment, it is in the form of a belt, which is stretched endlessly between pulleys 6 and 6, and is inserted through a shaft 7 as shown in the figure. Rotates in a fixed direction by a motor, etc.

The mask material may also have a hollow structure to securely hold the substrate.

Alternatively, a mechanical pond pressurizing device may be provided.

In short, the masking material has a liquid sealing function to prevent the plating liquid from rising above the boundary line A--A of the substrate 1.

Furthermore, since this embodiment also has the function of transporting the sandwiched substrate 1, a separate transport bell 5-2 (double-dashed line) may be provided in order to make the transport even more powerful.

4 is a reference conveyor which can move on a rail 16 and has a large number of reference pins 3 at the same level.

Since the reference pin 3 is accurately fitted into the reference hole 2, the outer diameter of the pin 3 is preferably finished with high accuracy, and the tip is preferably rounded to facilitate fitting.

In addition, in order to adapt to the diversification of the number of types of substrates 1, it is necessary to make the reference pins 3 protruding and retractable, and also to provide the reference pins 3 at the level of the pond in the height direction. If the pin 3 is configured to be able to slide within the groove from its position, it is possible to immediately respond even if the substrate 1 changes drastically.

The present invention is a means for solving the objects and problems by setting the distance C between the reference pin 3 and the lower end 5-1 of the masking material 5 to be C as shown in FIG.

Furthermore, with reference to FIG. 5, the application to a series of plating processes will be explained by way of example. 13 is a chemical polishing tank; 1 is a chemical polishing tank;
4 is a physical polishing tank such as a brush, and 15 is a solder removal tank.

When plating the terminal opening, the base is polished to improve its adhesion.

These methods include physical and chemical methods, and in the case of solder through-hole boards, the solder is also removed before polishing the base.

Here, in order to eliminate the zero plating process, etc., in which each process is arranged in a row and the reference conveyor 4 is passed to automatically process a continuous series of processes, all of the process liquid is dropped into each liquid receiving tank. You can leave it behind.

Alternatively, if the reference conveyor 4 is set at the same level and each type is set at different levels, it can be applied to the treatment of a pond with a plurality of boundary lines.

Next, the operating operation will be summarized. First, the reference conveyor 4 is brought to a stationary state, and the reference holes 2 of the substrate 1 are fitted into the reference pins 3 of the reference conveyor 4, so that the substrate 1 is attached to the reference conveyor 4.

(For automation, it is also possible to operate the reference conveyor 4 continuously at a position such as Y or Y' in Figure 5, and install an automatic fitting device that operates in synchronization with this conveyor to automatically attach the conveyor.) It is.

) Then, when the reference conveyor 4 is operated, the substrate 1 is fitted into the reference pin 8 and moves to the right as shown by the arrow in FIG.

When it comes to the front of the plating tank 8, it is clamped by the masking material 5 that has been activated in advance.

Since the masking material 5 is also operated at the same speed as the reference conveyor 4, the substrate 1 is transported.

By the way, the distance C between the lower end 5-1 of the masking material 5 and the reference pin 3 is the distance C between the boundary line A-A of the substrate 1 and the reference hole 2.
Therefore, when the substrate 1 enters the plating bath 8, the part below the boundary line A--A is immersed in the plating solution.

Then, the plating process is performed by supplying power to the terminal portion to be plated with the anode 9.

In this case, the terminal section - is connected to the cathode of a power supply device (not shown) from a power supply brush or the like via a conductive section C, as shown in FIG.

Additionally, since the conductive portion C is a cutting margin, it is cut and removed after the plating process.

As described above, according to the present invention, it is possible to improve productivity, achieve high quality, uniformity, and cost reduction without applying adhesive tape as a mask material to the non-plated portion of a printed wiring board. .

[Brief explanation of the drawing]

FIG. 1 is a printed wiring board, FIG. 2 is a plan view of the present invention,
FIG. 3 is a side view, and FIG. 4 is a process diagram of a series of five drawings, which is an enlarged, enlarged, and enlarged front view taken along the line X--X in FIG. 3. A-A... Boundary line to be plated, B-B...
...Perforation line of reference hole, C...Predetermined interval, E.
...Terminal length to be plated, A... Cutting allowance, mouth... Terminal part to be plated, C...
...Conductive part, 1...Printed wiring board, 1'.
...Bottom end of wiring board, 2...Reference hole, 3.
...Reference pin, 4...Reference conveyor,
5...Mask material, 5-1...Mask material lower end, 6...Pulley, 8...Plating tank, 8'... Opening, 10...Liquid receiving tank.

Claims (1)

[Scope of Claims] 1. At least two or more reference holes are drilled in the printed wiring board 1 so that the distance C between the boundary line A-A to be plated and the reference hole 2 is constant; The printed wiring board is mounted by fitting the reference hole 2 into the pin 3 of the tampering device, which is configured so that the distance between the reference pin 3 provided in the holder and the lower end of the mask material 5 is the same as the distance C. A method for plating the terminal portion of a printed wiring board 02, characterized in that the wiring board 1 is held between a belt-shaped mask material 5 and plating is performed continuously. A conveyor 4, a masking material 5 formed to be able to be transferred continuously to mask a required portion of the printed wiring board 1, a plating tank 8 having an opening 8' on the front shoulder, and a receiving plate for circulating a processing solution. It consists of a liquid tank 10 and a printed wiring board 1 having a plurality of reference holes 2 drilled at constant intervals C from the boundary line A-A to be plated, and furthermore, the printed wiring board 1 has a plurality of reference holes 2 formed at a constant distance C from the boundary line A-A to be plated, and furthermore, the reference pins 3 and the mask material 5 are A print characterized in that the lower ends are arranged to have the same interval C as described above, and the reference hole 2 is fitted into the reference pin 3 and the print is supplied to a plating bath to perform continuous plating processing. Wiring board terminal plating equipment. 3. The terminal portion plating apparatus for a printed wiring board 1 according to claim 2, wherein the mask material 5 is in the form of a belt stretched endlessly between the holes IJ-6 and 6.