JPS60131995A - Continuous plating method of terminal part of printed wiring board - Google Patents

Abstract

PURPOSE:To subject the terminal part of a printed wiring board to continuous plating by bringing the terminal part of said board into contact with the layer of the plating liquid flowing down beyond gates provided in a plating cell and conveying the board while performing liquid exchange thereby averting contamination by splashes. CONSTITUTION:A plating liquid 4 is admitted into a plating chamber 14 in an arrow direction so as to overflow from the top end 8' of a gate 8 by as much as the inflow amt. The plating liquid is dropped in the narrow passage between a pair of the gates 8 and 8 and is returned to a control tank; thereafter the circulation of the liquid 4 is repeated. On the other hand, a pair of conveying belts 3 extended by pulleys are operated and in succession, electricity is conducted to a power source for plating. The terminal part 2 of a circuit board 1 faced downward is sandwiched by the belts 3 in the prescribed position. Since slit notches through which the board 1 pass are provided to the gable plates of the entrance of a plating cell 11, the board 1 is transferred by the belts 3 and is passed between the right and left gates provided in the chamber 14. The terminal part 2 is subjected to a plating treatment by the plating liquid layer overflowing from the gates 8 and flowing downward.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a continuous plating method for terminal portions of grid/grid wiring boards.

In recent years, plating methods have always required higher speeds, and for this purpose, the conventional method of simply suspending and immersing the object in a plating solution and plating using ring gas decomposition has become more difficult. It is a well-known fact that since there is a limit, speeding up can be achieved by agitating the plating object or spraying a pressurized plating treatment liquid to stir the liquid (liquid exchange) on the surface of the plated part. However, in all of the injection methods, treatment is carried out by discharging the plating liquid from a discharge hole or slit toward the object to be plated, either in the entire pressurized plating solution or in the atmosphere.

By the way, the process of plating the terminals (connections) of the glint wiring board is the final process in the manufacturing of the glint wiring board, and the wiring circuits other than the parts to be glued are not allowed to get dirty, so there is no risk of splashing the processing liquid. In order to avoid any damage, a glass-based anti-corrosion sheet is pasted on the wiring circuit area other than the part to be plated and treated while being protected. However, if possible, it would be ideal to have a treatment method that does not involve the use of commercially expensive and time-consuming protective sheets. However, the above-mentioned method of discharging the pressure-circulating plating processing liquid through a small hole or slit cannot prevent the generation of splashes. Currently, measures are being taken to reduce the number of departments affected.

This application is for the purpose of plating the terminals of printed wiring boards, and is an innovative high-speed plating method that is completely different from conventional methods. The terminals of the printed wiring board are brought into contact with the flowing layer where the plating solution flows down, just as water flows down over a dam, and the board is transported while the solution is being exchanged. It is characterized by being plated.

The details of the embodiment will be explained below with reference to FIG. Figure 1 shows the main parts of a continuous plating device for printed wiring board terminals before the improvement according to the present invention.
In the figure, the terminal part 2, which is the part to be plated, is sent from the back side 1 to the front front side at a constant speed by the feeding belt 8.
The plating solution is plated using a submerged injection method, and the plating solution 4 is force-fed from below to the pressure chamber 5 according to the arrow in the figure, and is then passed through the nozzle 7.
This figure shows a state in which the terminal portion 2 is being plated by spraying the plating to a deeper depth. After the injection, the plating solution enters the pressureless plating tank 6 and overflows from both sides as shown in the figure, after which the plating solution 4 is circulated in a conventional manner. The present application breaks down the above-described method of renewing the plating solution by injection, and renews the plating solution by installing a weir 8 in the pressureless plating tank 11 as shown in Fig. 2 and immersing it in the plating solution flowing down and circulating. ? It is something to do.

The λ diagram, which is an example, shows the main part of the present invention, and in this case, a terminal part 2 of a printed wiring board 1 (hereinafter referred to as board 1).
Both the front and back sides are plated.

The board l is attached to the left and right pair of endless belts 171 by a conventional method.
! For ¥1, it can be transported horizontally from the back side to the front narrow side n1t. Note that there is a feeder 1 on the narrow side of the conveyor belt 8. Wire 9 is buried. And the conveyor belt is packed
Since it is supported by the lf id 10, the constant level It1
The substrate 1 is held horizontally toward the front while being held at all times. Note that 10' is a square frame connected to the air cylinder 16 and supported by pressing a guide 101 ft.

Next, to explain the plating processing chamber which is the wall of this application, number 11 is made of plated cypress, and there are 12 openings on the left and right sides of the tank that receive liquid from the plating solution management tank (liquid storage tank), as shown by the arrows. The plating solution flows into the plating chamber 14 through the current plate 1B. A pair of left and right weirs 8 are provided facing each other in the longitudinal center of the plating chamber, and the plating chamber is partitioned into left and right sides.
ing.

In addition, the anode 15 is placed downward from the B plate.
It is dripping into the liquid.

Next, to explain the operation, the bomb f (not shown) is
When f is activated, the plating liquid 4 is sucked from the plating liquid pipe 'fjJ and the plating liquid 4 flows into the plating chamber 14 as shown by the arrow through the mother pipe f'9r, and the amount of inflow exceeds the upper end 8' of the weir 8. It flows down a narrow flow path formed by a pair of weirs like Sawabu and returns to the control tank, after which the plating solution 4Vi KaJII is repeatedly viewed. A pair of conveyor bells (one on the other) 8
To 1! Then, continue to trace the plow source for plating, and at a predetermined position, place the terminal part of the board l completely below and clamp it on the conveyor belt 3. The board l is placed on the end plate of the inlet and outlet of the plating tank 11.
Since there is a slit-like notch through which the substrate 1 passes, the substrate l is transferred by the conveyor belt 8 between the left and right weir plates provided in the plating chamber. ! treat At this time, the terminal portion 2 is plated by the plating liquid layer flowing down over the weir 8.

As mentioned above, since the plating process is performed in the area where the flow overflows from the weir plate part, the liquid agitation (liquid exchange) in the part to be plated can be performed reliably, and the speed is equal to or higher than other speed-up processes currently being implemented. And, unlike the injection method, the space between the processing liquids is quiet and no splashes are generated. Therefore, there is no need for Ho@Teeg or Maskinda Teeg.

Note that in the case of a board terminal portion that requires a high degree of precision, it is sufficient to attach only the raised chives.

The reason why the gap between the pair of weir plates is narrowed as shown in the figure is that if the gap through which the substrate passes is widened, the amount of circulating liquid to maintain the liquid level will increase.

Also, by making + tooth-shaped notches in the shape 't-11 of the upper end 8' of the weir plate, or by making it into a chemical-resistant cloth shape,
It is possible to avoid observing the masking effect of the weir plate in terms of current.

Next, when plating only the terminal portion on one side of the substrate l in the above embodiment, it is possible to perform the plating without operating one of the liquid supplies on the right side.

As explained above, according to the present invention, not only does the plating solution not scatter unlike the injection method, but the nozzle and slit are not broken into pieces, so the nozzle hole is not blocked by foreign matter in the solution, and maintenance is easy. In addition, there is no need for air to get caught up in the circulating liquid thread and result in severe scattering, as is the case with the injection type.On the contrary, the overflow section exerts an ejector effect, so there is no need for special exhaust, and the air inside the plating chamber is kept clean. be.

There is no need to attach a protective sheet or masking to the substrate surface, and there is no splash, so there is no dirt, and the structure is simple and easy to manage.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional front view of a continuous plating apparatus using a submerged jet plating method, and the diagram is a longitudinal sectional front view of the apparatus according to the present invention. l...Glint wiring board, 2...Terminal section, 3...
Conveyor belt, 4... Plating solution, 8... Weir plate, 9...
- Power supply wire, 11... Plating tank %1B... Rectifier plate, 14... Plating chamber, 15... Anode. Patent Applicant Toyo Giken Kogyo Co., Ltd. Agent Patent Attorney Masaru Kato Disciple 1 Figure 2

Claims (2)

[Claims] (1) In a method in which a glint wiring board is transported above a plating tank while being held by a conveyor belt, and the terminals of the board are continuously grouted using plating cypress, a weir plate is placed inside the plating tank. A vertical flow layer is formed in which the plating solution flows down over a weir plate, and the terminal portion of the board is in face-to-face contact along the plating flow pipe, and the board is transferred to the hold and plated. Continuous plating method for board terminals. (2) A patent for plating the surface of a board terminal at the upper end of a channel where a plating solution flows down through the gap between a pair of weir plates facing each other in a plating bath. Claim No. 0
Continuous plating method for board terminals described in step 1.