JPH0766535A - Method and device for plating printed board - Google Patents

Abstract

PURPOSE:To make uniform efficiently the film thickness of a plated film on the end part of a printed board, to eliminate the need of modifying components conforming to a modification of the size of the printed board, to shorten an operating time and to prevent a plating device from being constituted into a complicated structure. CONSTITUTION:A plating device is constituted of metal frames 2, which are arranged in the vicinities of both surfaces of a printed board 1 in a plating tank 4 and have a size to correspond to that of the outer periphery of the board 1, anodes 3 which are respectively arragnen on the outsides of the frames 2, a first rectifier 6, which applies a negative voltage using the board 1 as a cathode side and applies a positive voltage using the anodes 3 as an anode side, and a second rectifier 7, which applies a positive voltage using the board 1 as an anode side after a plating is applied to the board 1 using the rectifier 6 and applies a negative voltage using the frames 2 as a cathode side to make thin a plated film on the end part of the board 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electroplating method and an apparatus therefor, and more particularly to a printed board plating method and apparatus for uniformly plating a printed board.

[0002]

2. Description of the Related Art In the case of plating a printed circuit board by electroplating, it is known that the plated film on the peripheral end of the printed circuit board becomes thicker, that is, the peripheral end effect of a thick plated film. Therefore, as a device for making the plating film uniform, for example, the device shown in Japanese Patent Laid-Open No. 63-64395 has been proposed. This device, as shown in FIG.
Insulating plate 12 and metal electrode 13 toward both sides near both sides of
Are arranged in this order, and the printed circuit board 11 is connected to the cathode side and the metal electrode 13 is connected to the power source section 16 as the anode side. The insulating plate 12 is provided with a plurality of holes 15 on the surface and a metal conductor 14 on the outer peripheral portion, and the metal conductor 14 is connected to the power supply unit 15 as the cathode side.

The plating method using this apparatus will be described below. First, when a positive voltage is applied to the metal electrode 13 and a negative voltage is applied to the printed board 11, metal ions are deposited on the pattern of the printed board 11 and tend to be thickly deposited at the peripheral edge. However, when a negative voltage is applied to the metal conductor 14, a part of the plating concentrated on the end portion of the printed board 11 is adsorbed by the metal conductor 14,
The deposition on the edges is not thick but uniform.

[0004]

In the conventional apparatus and method described above, the metal ions deposited on the printed board 11 are captured by the metal conductor 14 of the cathode on the way, and the plating film at the end is made uniform. Is not always enough. In addition, since it is necessary to dispose the metal conductor 14 near the end of the printed circuit board 11 in order to prevent unnecessary deposition on the end of the printed circuit board 11, when the printed circuit board 11 having a different size is used, the metal conductor 14 should be adjusted accordingly. The size of the metal conductor 14 must be changed, and the insulating plate 12 needs to be replaced every time the printed circuit board is changed, which requires a long working time and complicates the work.

The present invention has been made in view of the above problems, and makes it possible to efficiently make the plating film thickness at the end portion of the printed circuit board uniform and to eliminate the need to change the parts in accordance with the size change of the printed circuit board. An object of the present invention is to provide a plating method and an apparatus therefor.

[0006]

In order to achieve the above object, a method of plating a printed circuit board according to the present invention according to a first aspect of the present invention is such that a negative voltage is applied with the printed circuit board serving as a cathode side in a plating bath containing a plating solution. Applying a positive voltage with the anode as the anode side to form a plating film on the printed circuit board, and then applying the positive voltage with the printed circuit board on which the plating film is formed as the anode side to correspond to the outer circumference of the printed circuit board. There is a method of making the plating film uniform by applying a negative voltage with the metal frame to be used as the cathode side.

According to a second aspect of the present invention, there is provided a printed circuit board plating apparatus, which is disposed in the plating bath near both surfaces of a printed circuit board to be plated, and has the largest outer circumference of the printed circuit board. A metal frame having a size corresponding to, an anode arranged outside the metal frame, and applying a negative voltage with the printed circuit board as the cathode side,
A first rectifier applying a positive voltage with the anode as the anode side, and after performing a plating process by the first rectifier,
The printed circuit board is used as an anode side to apply a positive voltage, and the metal frame is used as a cathode side to apply a negative voltage to a second rectifier.

[0008]

In the present invention constructed as described above, the first rectifier applies a negative voltage to the printed circuit board and a positive voltage to the anode to form a plating film. Further, the second rectifier applies a positive voltage to the printed circuit board and a negative voltage to the metal frame to reduce the plating film thickness at the end of the printed circuit board.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a sectional view showing the configuration of a plating apparatus for a printed circuit board according to an embodiment of the present invention. In the plating tank 4 filled with the plating solution 5, the apparatus is arranged in the order of the metal frame 2 and the anode 3 toward the outside in the vicinity of both surfaces of the printed circuit board 1. As shown in FIG. 2, the metal frame 2 is formed by forming a metal that can serve as a metal electrode into a frame shape, and has a size matched to the peripheral edge of the largest printed circuit board among the printed circuit boards 1 to be plated. Has been formed.

The printed circuit board 1 is connected to the cathode side and the anode 3 is connected to the anode side of the first rectifier 6, which is a power source. The second rectifier 7 is connected to the printed circuit board 1 on the anode side and the metal frame 2 on the cathode side.

Next, an embodiment of the plating method using the above-mentioned plating apparatus will be described. When a negative voltage is applied to the printed board 1 by the first rectifier 6 and a positive voltage is applied to the anode 3, the printed board 1 is plated. At this time, the plating film thickness at the end portion of the printed circuit board 1 becomes thicker than the plating film thickness at the flat surface portion. After the application of the voltage from the first rectifier 6 is stopped, the positive voltage is applied to the printed circuit board 1 and the negative voltage is applied to the metal frame 2 by the second rectifier 7. As a result, a backflow current flows toward the end of the printed circuit board 1 closest to the metal frame 2 on the cathode side, and metal ions are positively emitted from the end of the printed circuit board having a large plating film thickness, thereby plating the end. The film thickness is reduced and a uniform thickness is efficiently formed.

Further, even if the printed circuit board 1 is changed to one having a different size, the end closest to the metal frame 2 is the printed circuit board 1, and the effect of reducing the plating film thickness at the end does not change. The plating film thickness is always made uniform. Therefore,
There is no need to change the metal frame 2, work time does not become long, and work is not complicated.

[0013]

As described above, according to the present invention, the plating film thickness on the end portion of the printed circuit board can be efficiently made uniform. Further, it is not necessary to change the parts in accordance with the change in the size of the printed circuit board, which can shorten the working time and prevent it from becoming complicated.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of the configuration of a printed circuit board plating apparatus according to the present invention.

FIG. 2 is a perspective view of a metal frame used in the above.

FIG. 3 is a sectional view showing the configuration of a conventional plating apparatus.

[Explanation of symbols]

 1 Printed circuit board 2 Metal frame 3 Anode 4 Plating tank 6,7 First and second rectifier

Claims (2)

[Claims] 1. A plating bath containing a plating solution,
A negative voltage is applied with the printed board as the cathode side, a positive voltage is applied with the anode as the anode side, and a plating film is formed on the printed board. A positive voltage is applied with the printed board having the plating film formed as the anode side. Then, a plating method for a printed circuit board, characterized in that the plated film is made uniform by applying a negative voltage with the metal frame corresponding to the outer periphery of the printed circuit board as the cathode side. 2. A metal frame, which is disposed near both sides of a printed circuit board to be plated in a plating tank and has a size corresponding to the outer periphery of the largest printed circuit board, and the outside of the metal frame. An anode disposed in, a first rectifier for applying a negative voltage with the printed board as a cathode side, and applying a positive voltage with the anode as an anode side, and a positive voltage with the printed board as an anode side, A printed circuit board plating apparatus comprising: a second rectifier that applies a negative voltage with the metal frame as a cathode side.