JPH11229198A - Plating apparatus for printed wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form the plating of the uniform thickness by turning a printed wiring board immersed in a plating solution blowing air from a bottom part of an electric copper plating bath to stabilize the plating bath. SOLUTION: A printed wiring board(PWB) 2 is fixed by inserting one piece of the PWB 2 in a groove of a rotary column 1c of a radial rotary set jig 1 in a completely contact manner. The radial rotary PWB set jig 1 is traveled above an electric copper plating bath 4 by a carrying device 3, and immersed in the electric copper plating bath 4 with a plating solution 7 therein. Air 6 is blown in one direction against the PWB 2 of the radial rotary PWB set jig 1 from an air pipe 5 set on he bath bottom, and the PWB 2 is turned. After the desired plating time is completed, air 6 is stopped to blow, the radial rotary PWB set jig 1 is lifted from the electric copper plating bath 4 by the carrying device 3, and after excessive plating solution stuck to the PWB 2 is dropped, the post-treatment such as water rinsing is achieved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plating apparatus for a printed wiring board, and more particularly to a plating apparatus for a printed wiring board which stabilizes a plating bath and facilitates formation of a plating having a uniform thickness.

[0002]

2. Description of the Related Art Electronic devices are becoming smaller, lighter, and more multifunctional, and printed wiring boards (hereinafter, referred to as PWBs) used in those electronic devices are increasingly used as mounting substrates for semiconductor electronic components. Its importance is increasing. As electronic components are mounted at higher density, PWB circuits and pads are required to be finer and through holes are reduced in diameter, and PWB manufacturing technology suitable for high-density mounting is more strongly required to be improved.

One of the important processes for miniaturizing PWB circuits and pads and reducing the diameter of through holes is an electrolytic copper plating process. In particular, it is necessary to improve the plating uniform deposition property in this process. I have.

A conventional PWB plating method will be described with reference to FIG. FIG. 3 is a perspective view showing an example of a conventional PWB electrolytic copper plating apparatus, in which PWB is immersed in an electrolytic copper plating tank and plating is performed. In FIG. 3, electrode leads and the like serving as copper electrodes (anodes) for electrolytic copper plating are not shown.

[0005] In the case of electroplated PWB with this electrocopper plating apparatus, first, a PWB such as a panel or a cage is used.
The PWB 2 fixed to the set jig 15 is put together with the PWB set jig 15 by the transfer device 3 in the electrolytic copper plating tank 4.
After being transported to the above-mentioned tank, it is lowered and immersed in the electrolytic copper electrolytic copper plating tank 4. An air 6 for stirring is blown out from an air pipe 5 at the bottom of the tank, or a plating solution 7 is circulated using a circulation pump to form an electrolytic copper electrolytic copper plating tank 4.
Of the PWB set jig 15
The copper electroplating process is performed while moving continuously in the vertical or horizontal direction.

[0006] Before the electrolytic copper plating in the electrolytic copper plating bath 4, the PWB 2 is set on a PWB set jig 15 to improve the adhesion of the electrolytic copper plating. Chemical treatments such as degreasing and etching are performed in a processing tank (not shown) disposed before.

When the PWB 2 is processed in the electrolytic copper plating bath 4, the plating solution 7 is insufficiently stirred only by stirring from the bottom of the tank with the air 6 or the circulation pump, and the concentration gradient of the plating solution is easily generated. There was a problem that the uniform deposition property of copper plating was reduced. After the plating treatment, the basket-shaped PWB set jig 15 is rested or moved continuously in the vertical direction on the electrolytic copper plating tank 4, and the PWB 2 and the plating adhered to the panel or cage-shaped PWB set jig 15 are returned. Although the solution 7 was drained, it was taken as a plating solution residue into the next post-plating treatment bath, causing discoloration of the surface of the PWB 2 and the like.

A method of improving plating uniformity by plating while rotating a PWB is disclosed in JP-A-3-119792, JP-A-57-210989, and JP-A-5-39-1.
No. 3196 is proposed.

FIG. 5 shows a plating apparatus disclosed in Japanese Patent Application Laid-Open No. 3-119792. In this technique, the PWB 2 is fixed to a PWB set jig 16 having a panel or basket shape,
After being immersed in the electrolytic copper plating tank 4 containing the plating solution 7 by the ascending and descending and traveling transport device, the PWB set jig 16 is set on the support column 17 on the rotating base 19,
18a and motor drive unit 1 connected to
8b is operated in the designated rotation direction and the number of rotations from the signal from the rotation control unit 18c, and the rotation base 19 also rotates, so that the PWB set jig 16 set on the support pillar 17 also rotates. A plating apparatus has been proposed.

[0010]

In the method of plating by rotating the PWB, the uniformity of the concentration of the plating solution on the PWB surface is improved because the PWB is rotated in the plating solution, and the plating uniformity is improved. However, there are drawbacks in that the device structure becomes complicated and that the number of PWBs that can be plated is as small as one or two. In addition, the pretreatment liquid for electrolytic copper plating is brought into the plating liquid 9 and contaminates the plating liquid 9, and there is a disadvantage that the uniform deposition property of the plating gradually decreases. The present invention
An object of the present invention is to provide a PWB plating apparatus that solves these problems of the related art.

[0011]

According to the first aspect of the present invention, the P
The WB plating apparatus is provided with an electrolytic copper plating tank, a jig receiver for electric supply, which is horizontally disposed on the electrolytic copper plating tank, is connected to a DC power supply, and is set on the jig receiver. An electric contact bar electrically connected to the jig receiver; two conductive posts connected to both ends of the electric contact bar and extending vertically downward; and a bridge connected to lower ends of the two posts and connected in a horizontal direction. A rotary rotary PWB set jig comprising a conductive rotary column having a groove rotatable about a rotating shaft and having a surface on which PWB can be radially arranged, and chucking the radial rotary PWB set jig. A transfer device capable of moving in and out of the electrolytic copper plating tank and moving horizontally, and blowing air from the bottom of the electrolytic copper plating tank onto the PWB immersed in a plating solution in the electrolytic copper plating tank to rotate the PWB radially. formula Characterized in that it is composed of an air pipe which is rotatable about the rotation axis of the rotary column of the WB setting jig.

In the plating apparatus having the first configuration according to the present invention, the radial rotary PWB is provided in the electrolytic copper plating tank.
A mechanism may be provided for automatically starting the air blowing into the electrolytic copper plating bath when the setting jig is completely set, and automatically stopping the air blowing at the end of the plating time.

[0013] The plating apparatus of the second configuration according to the present invention is the plating apparatus of the first configuration, further comprising a spray for water washing provided on the transfer device, and after plating, the PWB on the electrolytic copper plating tank. Washing water is sprayed from the spray for washing water so that washing can be performed while rotating the PWB around the rotation axis of the rotating column of the radial rotary PWB set jig.

[0014] In the plating apparatus of the second configuration, the radial rotary PWB set jig is automatically opened and removed by the sequence control when the radial rotary type PWB set jig is taken in and out of the electrolytic copper plating bath and during plating. Thus, a cleaning solution preventing cover that automatically closes when the PWB is washed with water can be provided in the electrolytic copper plating tank to prevent the cleaning liquid from entering the electrolytic copper plating tank.

In the plating apparatus according to the second aspect of the present invention, the plating adhered to the radial rotary PWB set jig is improved by improving the uniformity of PWB plating and providing the water washing spray on the transporting apparatus. The solution can be removed, the amount of the plating solution and the like brought into the post-plating treatment tank can be reduced, and the effect of preventing discoloration of the PWB surface and extending the life of the chemical solution in the post-plating treatment tank can be obtained. .

[0016]

Embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic perspective view of a PWB plating apparatus and a plating method using the PWB plating apparatus according to the first embodiment of the present invention. In the drawings, the anode for plating, the lead wire for electroplating, and the circulation pipe for plating solution are omitted from the display because ordinary techniques are used.

As shown in FIG. 1, a plating apparatus according to a first embodiment of the present invention is provided with an electrolytic copper plating tank 4 for containing a plating solution 7 and a horizontal arrangement on the electrolytic copper plating tank 4. A jig receiver 8 for supplying electricity connected to a DC power supply;
An electric contact bar 1a set on the jig receiver 8 and electrically contacting the jig receiver 8, and two conductive columns 1b connected to both ends of the electric contact bar 1a and extending vertically downward, and the two conductive columns 1b. A rotary rotary PWB set jig 1 comprising a conductive rotary column 1c which is cross-linked to the lower end of a support column 1b, is rotatable about a horizontal direction as a rotation axis, and has a groove on its surface on which a PWB 2 can be radially arranged. A transport device 3 that chucks the radial rotary PWB set jig 1 with the handle portion 3a, and moves the jig 1 into and out of the electrolytic copper plating tank 4 and moves horizontally.
Air 6 is applied to plating solution 7 from the bottom of electrolytic copper plating tank 4.
And an air pipe 5 for rotating the PWB 2 around the rotation shaft 1c of the radially rotating PWB set jig 1 by spraying the PWB 2 immersed in the PWB 2.

Further, in the plating apparatus of the present invention, when the radial rotary type PWB set jig 1 is completely set in the electrolytic copper plating treatment tank 4, air blowing into the electrolytic copper plating treatment tank 4 is automatically started. A mechanism for automatically stopping the blowing of air at the end of the plating time (not shown)
Is provided.

A PWB plating method using the plating apparatus of the first embodiment will be described in detail with reference to FIG.

First, the PWB 2 is inserted and fixed in such a manner that one side of the PWB 2 comes into contact with the groove of the rotary column 1c of the radial rotary type PWB set jig 1 in which the PWB 2 can be radially arranged in the PWB mounting / removing area. The radial and rotary PWB set jig 1 is run on the electro-copper plating bath 4 by the transporting device 3 that drives and runs the up-and-down drive motor under control, and the electro-copper plating containing the plating solution 7 is performed. It is immersed in the processing tank 4. The number of PWBs 2 to be set in the radial rotary PWB set jig 1 is 4 to 6
When the number of PWB2 is less than four, the rotation can be stabilized by using a dummy plate having the same size as that of the PWB2.

Next, air 1 to 50 L / min is blown from one direction to the PWB 2 of the radial rotary PWB set jig 1 from the air pipe 5 set at the tank bottom.
Rotate WB2. An appropriate rotation speed of the PWB 2 is 1 to 10 times / minute. By rotating the PWB 2 in the plating solution 7, the uniformity of the concentration of the plating solution 7 on the surface of the PWB 2 can be improved, and the variation in the plating thickness of the PWB 2 can be kept within 1.0%.

Next, after the desired plating time is over, the blowing of the air 6 is stopped, and the transport device 3 rotates the radial rotary PWB.
After the set jig 1 is lifted from the electrolytic copper plating tank 4, the jig 1 is stopped on the electrolytic copper plating tank 4, and excess plating solution attached to the PWB 2 is dropped into the electrolytic copper plating tank 4. Next, post-treatment such as a washing tank is performed to complete the plating.

Next, a PWB plating apparatus according to a second embodiment of the present invention will be described with reference to FIG.

As shown in FIG. 2, the plating apparatus of the present embodiment differs from the plating apparatus of the first embodiment of FIG.
A water washing spray 13 is provided below the handle 3a of the transport device 3.
After the plating, the washing is performed by spraying washing water 14 from the spray onto the PWB 2 on the electrolytic copper plating tank 4 so that the PWB 2 can be washed while rotating. Wash water 14
The amount of water is sprayed at a flow rate of 10 to 100 L / min from one side to the rotation axis of the PWB 2 at a flow rate of 10 to 100 L / min for 1 to 5 minutes while rotating the PWB 2 of the radial rotary type PWB set jig 1 5 to 50 times / min. Perform cleaning.

In this embodiment, as shown in FIG.
The drive motor 10 is driven by the sequence control to automatically open the radial rotary PWB set jig 1 into and out of the electrolytic copper plating tank 4 and during plating, and the PWB 2 is washed with water by the water spray 13. A cleaning liquid prevention cover 9 that is sometimes automatically closed is provided in the electrolytic copper plating tank 4. The cleaning liquid preventing cover 9 prevents the cleaning liquid from being mixed into the electrolytic copper plating tank 4.

The water-washing spray 13 is connected to a water-washing spray pipe 11, and the ON / OFF of the sprayed washing water is controlled by an electromagnetic valve 12 connected to the water-washing spray pipe 11. Further, an enclosure (not shown) can be provided around the transfer device 3 for preventing the washing water and the washing liquid from scattering when the PWB 2 is spray-washed with the water washing spray 13.

In the plating apparatus of the present embodiment, the plating solution adhered to the radial rotary type PWB set jig 1 can be removed by providing the water washing spray 13 in the transporting apparatus while improving the plating uniformity of the PWB. Since it is possible to reduce the amount of plating solution and the like brought into the post-treatment tank (not shown), it is possible to prevent discoloration of the PWB surface,
The effect of extending the life of the chemical solution in the post-plating treatment tank can be obtained.

[0029]

As described above, in the PWB plating apparatus of the present invention, the PWB is set on the radial rotary PWB set jig, and the air and the plating solution are applied from the bottom of the electrolytic copper plating tank.
The following effects can be obtained because a mechanism is provided for spraying the WB, rotating the PWB to perform plating, and performing spray cleaning on the plating tank after plating. (1) The uniformity of the concentration of the plating solution on the PWB plating surface is improved, and the plating uniform deposition property (plating throwing power)
Can be improved. (2) The carry-in of the chemical solution into the electrolytic copper plating tank and the pre- and post-plating treatment tanks can be reduced, and the life of the chemical solution in each tank can be prolonged and the PWB plating quality (such as discoloration prevention) can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view of a PWB plating apparatus and a plating method using the plating apparatus according to a first embodiment of the present invention.

FIG. 2 is a schematic perspective view of a PWB plating apparatus and a plating method using the plating apparatus according to a second embodiment of the present invention.

FIG. 3 is a perspective view showing a conventional printed wiring board plating apparatus.

FIG. 4 is a perspective view showing another conventional apparatus for plating a printed wiring board.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Radial rotary type PWB set jig 1a Electric contact bar 1b Support 1c Rotating column 2 PWB 3 Conveyor 3a Handle 4 Electrolytic copper plating tank 5 Air piping 6 Air 7 Plating treatment liquid 8 Jig receiving 9 Cleaning liquid prevention cover 10 Drive Motor 11 Spray pipe for water washing 12 Solenoid valve 13 Spray for water washing 15, 16 PWB set jig 17 Support column 18a Motor 18b Motor drive unit 18c Rotation control unit 19 Rotary base

Claims (4)

[Claims] An electrolytic copper plating tank, a jig receiver for electric supply, which is horizontally disposed on the electrolytic copper plating tank, and a jig receiver set on the jig receiver, Electrical contact bar, two electrically conductive columns connected to both ends of the electrical contact bar and extending vertically downward, and bridge-connected to the lower ends of the two columns to be rotatable about the horizontal direction as a rotation axis. And a radial rotating printed wiring board set jig comprising a conductive rotating column provided with a groove on the surface of which a printed wiring board can be radially disposed, and chucking the radial rotating printed wiring board set jig. A transfer device capable of moving in and out of the electrolytic copper plating tank and moving horizontally, and blowing air from the bottom of the electrolytic copper plating tank onto the printed wiring board immersed in a plating solution of the electrolytic copper plating tank. Before A plating apparatus for a printed wiring board, comprising: an air pipe rotatable around the rotation axis of the rotating column of the radial rotary printed wiring board set jig. 2. When the radial rotary printed wiring board setting jig is completely set in the electrolytic copper plating tank, the air blowing is automatically started into the electrolytic copper plating tank, and the plating time is reduced. 2. The apparatus for plating a printed wiring board according to claim 1, further comprising a mechanism for automatically stopping the blowing of the air upon completion. 3. An electrolytic copper plating tank, a jig receiver for electric supply, which is horizontally disposed on the electrolytic copper plating tank, is connected to a DC power supply, and is set on the jig receiver. An electric contact bar electrically connected to the jig receiver; two conductive posts connected to both ends of the electric contact bar and extending vertically downward; and a bridge connected to lower ends of the two posts and connected in a horizontal direction. A radially rotating printed wiring board set jig comprising a conductive rotating column provided with a groove rotatable about a rotating shaft and having a surface on which printed wiring boards can be radially disposed, and the radially rotating printed wiring board set A transfer device capable of chucking a jig, moving in and out of the electrolytic copper plating tank and moving horizontally, and the printed wiring board having air immersed in a plating solution in the electrolytic copper plating tank from the bottom of the electrolytic copper plating tank Spraying on An air pipe capable of rotating the printed wiring board around the rotation axis of the rotating column of the radial rotary printed wiring board set jig, and provided on the transfer device, and after plating, on the electrolytic copper plating tank. A water washing spray that sprays washing water on the printed wiring board and can wash the printed wiring board while rotating the printed wiring board around the rotation axis of the rotating column of the radial rotary printed wiring board set jig. A printed wiring board plating apparatus characterized by the above-mentioned. 4. When the radial rotary type PWB set jig is taken in and out of the electrolytic copper plating bath and automatically during plating by sequence control, and when the PWB is washed with water by the water washing spray. 4. The apparatus for plating a printed wiring board according to claim 3, wherein a cleaning liquid preventing cover that automatically closes is provided in the electrolytic copper plating tank.