JPH11220257A - Manufacturing device of printed wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To fully supply liquid into all through holes of a printed wiring board, by alternately blowing foam from a pipe for aeration, and by using a suspension member as a support for rocking a tool for mounting a printed wiring board in the liquid. SOLUTION: Pipes 4 and 5 for aeration are arranged in the longitudinal direction of a tank 1 at the lower part in the tank 1, and pipes 6 and 7 for auxiliary aeration are arranged in the longitudinal direction of the tank 1 near the pipes 4 and 5. A tool 11 suspended by a suspension member 14 is lowered to the middle between electrodes 3 in the tank 1 and is dipped into liquid. Then, conduction is made between both electrodes 3 in the tank 1 and the suspension member 14, foam is continuously blown from the pipes 6 and 7 for auxiliary aeration, at the same time, the foam is alternately blown from the pipes 4 and 5 for aeration, and the tool 11 is rocked in the liquid by using the suspension member 14 as a support.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for manufacturing a printed wiring board, and more particularly, to a plating apparatus for establishing conduction between respective layers of the printed wiring board.

[0002]

2. Description of the Related Art A large number of through holes and / or non-penetrating through-holes (hereinafter referred to as "sulfur-holes") are provided on a printed wiring board entirely or partially.
During the plating process, a sufficient amount of plating solution is supplied into the through holes as necessary, so that a uniform thickness of plating is formed not only on the front and back surfaces of the printed wiring board, but also on the inner wall surfaces of the through holes. You need to do that.

For this purpose, in a plating tank in which a printed wiring board is immersed, a jig on which the printed wiring board is mounted is swung upward, or as shown in FIG. A method in which bubbles 22 are generated in the plating solution 21 and the bubbles are traced on the surface of the printed wiring board 23 to stir the plating solution near the surface (bubbling) is used alone or in combination.

[0004]

However, even when the upper part of the jig is swung, the movement of the lower part of the jig is hindered by the viscous resistance of the plating solution, so that the jig does not sufficiently swing. Therefore, in the printed wiring board arranged below the jig, the plating solution remains on the surface of the printed wiring board and in the through hole, and the supply of the plating solution is not performed uniformly, so that a uniform plating film thickness is formed in the through hole. Not formed.

For this reason, it is conceivable to swing the jig below the jig. For this purpose, it is necessary to provide a swinging device also in the lower portion of the tank, which complicates the structure and leads to an increase in cost.

On the other hand, even in the method by bubbling, since bubbles only rise and stir so as to trace the surface of the printed wiring board, it cannot be said that the plating solution is sufficiently supplied into the through holes.

An object of the present invention is to provide an apparatus for manufacturing a printed wiring board in which a liquid is sufficiently supplied also in all through holes of the printed wiring board.

[0008]

An apparatus for manufacturing a printed wiring board according to the present invention comprises a tank containing a liquid, preferably a tank containing a plating solution, and a suspending member disposed above the tank outside the tank. The jig which is hung by the suspending member and attaches the printed wiring board in the vertical direction, and is immersed in the liquid of the tank, and is located on both sides of the printed wiring board immersed in the tank, respectively. Aeration pipes arranged in such a manner that air bubbles are alternately blown out of the aeration pipes, whereby the jig to which the printed wiring board is attached is swung in the liquid with the suspension member as a fulcrum. It is characterized by the following.

The apparatus for manufacturing a printed wiring board according to the present invention further comprises a tank containing a solution, preferably a tank containing a plating solution.
A suspending member arranged above the tank outside the tank, a jig suspended from the suspending member, and attached to the printed wiring board in a vertical direction, and immersed in the liquid of the tank; A jig on which the printed wiring board is mounted by intermittently blowing air bubbles from the aeration pipe, comprising: an aeration pipe arranged to be positioned on one side of the printed wiring board soaked. Is swung in the liquid with the suspension member as a fulcrum.

[0010] Further, tubes for auxiliary aeration are further arranged so as to be located on both sides below the printed wiring board immersed in the liquid in the bath, and the pipes are constantly traced on both surfaces of the printed wiring board. It is characterized by bubbles coming out.

[0011] Further, the invention is characterized in that a steady rest member for regulating the swing width of the printed wiring board is arranged in the tank.

Further, the suspension member reciprocates in the same direction as the swinging direction of the printed wiring board.

[0013] Further, the apparatus has a plurality of tanks and a transfer device, and the transfer device causes a suspension member to raise the jig from one tank, move and lower the jig in another tank. .

Further, the suspension member also serves as a cathode bar.

[0015]

1 to 3 show an electrolytic copper plating tank as an example of an apparatus for manufacturing a printed wiring board according to the present invention. (Anode electrode) 3 made of copper is arranged in a vertical direction along opposing wall surfaces in the tank 1. 3a
Is an electric cable connected to the electrode 3.

Below the inside of the tank 1, two aeration pipes 4, 5 are arranged in the longitudinal direction of the tank, and in the vicinity thereof, there are also auxiliary aeration pipes 6, 5 in the longitudinal direction of the tank.
7 are arranged. Two aeration tubes 4,
Numerals 5 are each connected to a blower (not shown) via a valve 8 composed of an electromagnetic valve or the like. On the other hand, the auxiliary aeration tubes 6 and 7 also become one tube 9 and are connected to another or the same blower (not shown). The aeration tubes 4, 5 and the auxiliary aeration tubes 6, 7 are each provided with a number of holes 4a, 5a,
6a and 7a are provided.

Each of the printed wiring boards 10 to be copper-plated is attached to a jig 11. The jig 11 has two vertically extending mounting members 12 arranged apart from each other as shown in FIG. 2, and one or more (three in FIG. 2) printed wiring boards vertically arranged on the mounting members 12. 10 are attached to the attachment member 12 on both left and right sides thereof with bolts and nuts, respectively.

A hook member 13 is provided at the upper end of the mounting member 12 of the jig 11 so that the jig 11
4 is hung. The suspension member 14 also serves as a cathode bar. In FIG. 2, four sets of jigs 11 are suspended by suspension members 14.

The jig 11 suspended by the suspension member 14
Descends to the middle between the two electrodes 3 in the tank 1 and is immersed in the liquid. The above described aeration tubes 4 and 5 and auxiliary aeration tubes 6 and 7 are arranged so as to be positioned on both surfaces of the jig 11, that is, the printed wiring board 10, which is lowered and placed in the tank. In addition, a steadying member 15 for regulating the shake of the jig 11 is arranged near the lower part of the jig 11 arranged in the tank 1. 15a is a support member for supporting the steady rest member 15.

When a current flows between the anode electrode 3 and the cathode bar 14 (suspension member), the jig 11 descends and the printed wiring board is immersed in the liquid, and as shown in FIG. , 7, bubbles are constantly generated and rise so as to trace both sides of the printed wiring board to agitate the liquid near the surface of the printed wiring board. Here, as shown in FIG. 4B, when bubbles 4b start to emerge from the aeration tube 4, the jig 11
Is pushed by the buoyancy of the bubbles and swings toward the aeration tube 5 with the suspension member 14 as a fulcrum (FIG. 4c).

Next, when the generation of bubbles from the aeration tube 4 stops and bubbles 5b start to emerge from the aeration tube 5, the jig 11 swings toward the aeration tube 4 (FIGS. 5a to 5c). Thus, the jig 11 is swung. The alternate supply and stop of air to the aeration tubes 4, 5 is controlled by a valve 8. The tube diameter, hole diameter, air supply amount, and the like are set so that the aeration tubes 4 and 5 generate a larger amount of air bubbles than the auxiliary aeration tubes 6 and 7.

When the jig 11 swings in this manner, the jig 1
The liquid passes through a large number of through holes provided in the printed wiring board 10 attached to the liquid crystal panel 1, and bubbles that have entered the through holes are pushed out. Therefore, the liquid does not stay in the through-hole, the liquid is uniformly supplied into the through-hole, and the liquid is evenly distributed on all the through-hole inner wall surfaces of all the printed wiring boards attached to the jig 11. A plating film having a plating thickness is formed.

In the present invention, since the printed wiring board oscillates in the liquid, even if the aspect ratio is high, such as a thick plate and a small through-hole diameter, the liquid can sufficiently penetrate into the through-hole and the plating film thickness can be reduced. A uniform and highly reliable printed wiring board can be produced.

In order to increase the swinging movement of the jig 11, particularly the swinging movement above the jig, the suspension member 14 is moved in accordance with the swinging movement of the jig 11 as shown by an arrow A in FIG. Reciprocation may be performed in the swing direction. That is, both ends of the suspension member 14 may be placed on a moving device (not shown) having wheels that move on the rail, and the moving device may be reciprocated a short distance.

The case where one jig is used in one tank as a plating tank has been exemplified, but a type in which three anode electrodes are arranged in one tank and two jigs can be immersed in parallel between them at the same time. The tank may be of any type. Alternatively, the suspension member 14 may be moved up and moved to a tank for the next processing after plating is completed by a transfer device (not shown).

In FIGS. 1 to 5, the aeration tubes 4 and 5 are arranged near the lower end of the jig 11,
As shown in FIG. 6, the jig 11 may be disposed below the lower end. Alternatively, only one aeration tube 16 may be provided as shown in FIG. 7 and the jig may be swung by intermittently generating air bubbles. Further, as shown in FIG. 8, the tube for auxiliary aeration may be eliminated and only the tube for aeration may be used. The aeration tube and the aeration tube are placed on both sides or one side of the printed wiring board.
A plurality of lines may be provided instead of a line.

The present invention is not limited to the plating process, and can be applied not only to other wet surface treatments such as blackening and cleaning of a printed wiring board, but also to an apparatus having a structure in which liquid other than the printed wiring board is easily retained. Also applicable to

[0028]

<Example 1> A printed wiring board having a large number of through holes of 0.35 mm in diameter using an electroplating tank (250 cm long, 60 cm wide and 135 cm high) shown in FIGS. Height 30cm, width 40cm, thickness 1.6
mm) is attached to each of the four jigs in three at a time for 12 minutes for 60 minutes.
Copper plating was performed at 00A. At this time, the aeration pipes 4 and 5 are opened and closed every 15 seconds by the valve 8 and 1N per minute.
Air was discharged at a flow rate of m ³ . On the other hand, air was constantly discharged from the auxiliary aeration tubes 6 and 7 at a flow rate of 0.5 Nm ³ per minute. Further, the cathode bar 14 was swung by a width of 25 mm at a cycle of 0.25 Hz.

As a result, copper plating having a thickness of 25 μm was deposited on the surface of the printed wiring board at the portion 10a. When the plating film thickness deposited on the inner wall of the through hole of this printed wiring board was measured by cross-sectional observation, the plating film thickness of the inner wall of the through hole at 100 through holes was 1 as shown in FIG.
80% of the 00 locations were almost uniform at 17.5 μm to 20 μm.

Comparative Example 1 As a comparative example, copper plating was carried out under the same conditions as in Example 1 except that there were no tubes 4 and 5 for aeration. The plating thickness deposited on the inner wall of the through hole of the printed wiring board at the same location as in Example 1 was measured by cross-sectional observation, and as shown in FIG.
The plating film thickness on the inner wall of the through-hole at various locations varies and does not become uniform.

[0031]

According to the printed wiring board manufacturing apparatus of the present invention, the printed wiring board attached to the jig swings due to the buoyancy of the air bubbles discharged from the aeration tube, so that the liquid also flows in the through holes. The bubbles that pass through and enter the through-hole are pushed out, so that the liquid does not stay in the through-hole and the liquid is uniformly supplied to the through-hole, and the through-hole in the entire area of the printed wiring board is provided. A uniform plating film thickness is also formed on the inner wall.

Also, by providing auxiliary aeration tubes so as to be located on both sides of the printed wiring board, bubbles are constantly generated from these tubes so as to trace both surfaces of the printed wiring board, and the liquid on the surface of the printed wiring board is stirred. Is done.

By providing a steadying member for regulating the swing width of the printed wiring board in the tank, the printed wiring board is prevented from hitting the electrodes and the wall surface of the tank, and these are prevented from being damaged. In addition, since the printed wiring board is always maintained at an appropriate distance between the electrodes, a plating layer having an appropriate thickness can be formed on the surface including the inner wall of the through hole of the printed wiring board.

The swing is more effectively performed by the reciprocating movement of the suspension member in the same direction as the swing direction of the printed wiring board.

A plurality of tanks and a transfer device are provided, and a suspension member raises and lowers the jig from one tank by the transfer device. Can process and manufacture printed wiring boards.

Since the suspension member also serves as the cathode bar in the electroplating tank, it is not necessary to separately provide a cathode electrode, and the structure is simplified.

[Brief description of the drawings]

FIG. 1 is a side sectional view of a printed wiring board manufacturing apparatus according to the present invention.

FIG. 2 is a front sectional view.

FIG. 3 is a plan view.

FIG. 4 is a diagram illustrating a swing state of a printed wiring board.

FIG. 5 is a diagram illustrating a swing state of a printed wiring board.

FIG. 6 is a view showing another arrangement of aeration tubes.

FIG. 7 is a diagram showing another arrangement of aeration tubes.

FIG. 8 is a view showing another arrangement of a pipe for aeration.

FIG. 9 is a graph showing the results of Example 1.

FIG. 10 is a graph showing the results of Comparative Example 1.

FIG. 11 is a diagram showing a conventional aeration method.

[Explanation of symbols]

 Reference Signs List 1 tank 2 liquid level 3 electrode (anode electrode) 4 tube for aeration 4a hole 5 tube for aeration 5a hole 6 tube for auxiliary aeration 6a hole 7 tube for auxiliary aeration 7a hole 8 valve 9 tube 9 printed wiring board 11 Jig 12 Attachment member 13 Hook member 14 Suspension member (cathode bar) 15 Anti-sway member 16 Tube for aeration

Continuing on the front page (72) Kunitaka Takahashi, Inventor Kunihisa, Higashi-Asai-gun, Shiga Prefecture

Claims (8)

[Claims] 1. A tank containing a liquid, a suspending member disposed above the tank outside the tank, and a printed wiring board suspended from the suspending member and mounted in a vertical direction. A jig that is immersed in the tank, and a pipe for aeration arranged so as to be located on both sides of the printed wiring board immersed in the tank, and air bubbles are alternately blown from the pipe for aeration. Wherein the jig to which the printed wiring board is attached is swung in the liquid with the suspension member as a fulcrum. 2. A tank containing a liquid, a suspending member disposed above the tank outside the tank, and a printed wiring board suspended in the suspending member and mounted in a vertical direction. A jig that is immersed in the tank, and an aeration tube that is arranged to be located on one side of the printed wiring board that is immersed in the tank, and intermittently blows bubbles out of the aeration tube. Wherein the jig to which the printed wiring board is attached is swung in the liquid with the suspension member as a fulcrum. 3. The apparatus for manufacturing a printed wiring board according to claim 1, wherein the solution contained in the tank is a plating solution. 4. A tube for auxiliary aeration is further arranged so as to be located on both lower sides of the printed wiring board immersed in the liquid in the tank, and traces both surfaces of the printed wiring board from these pipes. The apparatus for manufacturing a printed wiring board according to any one of claims 1 to 3, wherein bubbles are constantly generated. 5. The apparatus for manufacturing a printed wiring board according to claim 1, wherein a steadying member for regulating a swing width of the printed wiring board is disposed in the tank. 6. An apparatus for manufacturing a printed wiring board according to claim 1, wherein the suspension member reciprocates in the same direction as the swing direction of the printed wiring board. 7. The apparatus according to claim 1, further comprising a plurality of tanks and a transfer device, wherein the transfer device causes a suspending member to raise the jig from one tank and move the jig down to another tank. An apparatus for manufacturing a printed wiring board according to any one of the preceding claims. 8. The printed wiring board manufacturing apparatus according to claim 1, wherein the suspension member also serves as a cathode bar.