JPS6151891A - Smear removing device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a smear removal device, and more particularly to a smear removal device fJf for removing smear in through holes of a printed circuit board using gas plasma.

[Background of the invention]

Examples of smear removal devices that remove smears from through holes in printed circuit boards using gas plasma include those disclosed in U.S. Patent No. 4.289.598 and U.S. Patent No. 1.3.
As described in the specification of No. 28.081, a printed circuit board is placed between parallel plate electrodes, and etching gas is introduced from several places in the processing chamber to generate gas plasma, and the gas plasma smears the through holes of the printed circuit board. Devices for removing .

However, such an apparatus has the problem that the etching distribution becomes non-uniform due to the electrical discharge of the printed circuit board itself and the resistance to the flow of the etching gas.

[Purpose of the invention]

The purpose of the present invention is to make the etching of through holes more uniform between the center and periphery of the printed circuit board by drawing strong gas plasma generated at the periphery of the printed circuit board into the center of the printed circuit board. An object of the present invention is to provide a smear removal device that can improve the uniformity of etching distribution.

[Summary of the invention]

The present invention is capable of drawing etching gas flowing corresponding to the surface of a printed circuit board placed in a processing chamber provided with a power supply electrode and a ground electrode into the vicinity of the center of the opposite surface of the printed circuit board. This device is characterized by having an exhaust hole in the electrode facing the opposite side of the printed circuit board from the ground electrode, which draws the strong gas plasma generated at the periphery of the printed circuit board into the center of the printed circuit board. This is an attempt to make the amount of through-hole etching more uniform between the center and the periphery of the printed circuit board.

[Embodiments of the invention]

An embodiment of the present invention will be explained with reference to FIG.

In FIG. 1, the power supply electrode 10 is 11! Electrode plate 11 and electrode axis β
The ground electrode is connected to the electrode plate 21 and illi
It is composed of m axis and n. The electrode shaft 12 is electrically insulated and airtightly provided on the bottom wall of the processing chamber 3o, in this case, with its upper end protruding into the processing chamber. At the upper end of the fully exposed shaft 12, an electrode plate 11 is provided substantially horizontally. An electrical insulating material 40 is provided between the outer peripheral end of the electrode plate 11 and the side wall of the processing chamber 30, and the electrical insulating material 40 is sealed to prevent etching scum from passing through the space. lit I6?
A power source installed outside the processing room, for example, a 1111 frequency power source 50, is connected to the lower end, which is the other end of the support 12.

The high frequency source 50 is grounded.

The electrode (122) is airtightly provided between the processing chambers, in this case, on the top wall, with its lower end (one end) protruding from the inside of the processing chamber. It is provided substantially horizontally facing the electrode plate (1).

A gas dispersion chamber A is formed inside the electrode plate 21, and gas discharge holes opening 1:1 on the surface facing the electrode plate 11 are bored in communication with the gas dispersion chamber n.

A waste supply h'625 is formed in the axial direction inside the electrode shaft n in communication with the gas dispersion chamber n. At the upper end of the other end of the electrode shaft n, a gas supply pipe 61 connected to an etching gas source 60 installed outside the processing chamber is connected in communication with a gas supply path. Electrode axis n is grounded. Here, the width of the electrode plate 11.21 is wider than the width of the printed circuit board 70, and the length thereof is greater than the width of the printed circuit board 70.
It is longer than the length of . In this case, power @ pole 10
A bracket booklet is specially installed on the side between the processing chambers via an electrical insulating material 41 so that the printed circuit board 7o can be placed between the 111 electrode plate 11 and the electrode plate 21 to which the ground electrode is added. An exhaust nozzle 3 is provided on the bottom wall of the processing chamber J in communication with a space 90 formed by the electrode plate 11, the bottom wall on the processing chamber side, and the electrical insulating material 4o.
1 is provided, and the exhaust nozzle 31 is a vacuum exhaust system a 10
Connected to 0. The surface of the printed circuit board 7o, in this case, the air flowing from the center to the peripheral part corresponding to the top surface, can be included in the center part 1 of the bottom surface, and in this case, an exhaust hole is formed in 1rL of the power supply electrode 10 + jit plate 11. 110 is bored.

In FIG. 1, a printed circuit board 7o is carried into the processing chamber from the outside, and this carried printed circuit board 7o is supported by a bracket 80. Thereafter, the inside of the processing chamber is evacuated to a predetermined pressure by the operation of the evacuation device 100. Thereafter, etching gas is supplied from the etching gas source 6o to the gas supply path 5 via the gas supply Q61 at a predetermined flow rate. After the gas is distributed and dispersed by the gas dispersion Murota, it is released from the gas release hole toward the top surface of the printed circuit board 70.The released residue passes through the through hole (step omitted) of the printed circuit board 7o and the printed circuit board 7o. The air flows from the center toward the periphery corresponding to the upper surface of the 7°Φ, passes through the 1-node pore 110, the space 9 (), and the exhaust nozzle 31, and then is pumped at a predetermined flow rate by the air device 100. This causes the print J to be evacuated.
The etching gas flowing from the center toward the periphery corresponding to the upper surface of the printed circuit board 70 is drawn into the vicinity of the center of the lower surface of the printed circuit board 70, and the inside of the processing chamber (9) is maintained at a predetermined etching pressure. adjusted and maintained. In this state, among the gas plasma generated by applying high frequency power to the IIT+10, the strong gas plasma generated around the printed circuit board 70 is
The gas plasma is drawn into the center of the printed circuit board 70 and spread over the entire surface of the printed circuit board 70. The smear in the through hole of the printed circuit board 70 is cornoted and removed by this gas plasma.

The smear removal device of this embodiment provides the following effects.

(1) Etching i11 of through-holes in the center and periphery of the printed circuit board can be made uniform, and the uniformity of etching distribution can be improved.

(2) The strength of the gas plasma can be leveled out in the strong direction, and it is possible to obtain 1.

FIG. 2 shows the second embodiment of the smear removal device according to the present invention. The difference from FIG. The point is that a plurality of these are used and alternately arranged in double rows facing each other in the lateral direction within the processing chamber. Therefore, in this case, exhaust holes 110' having the above-mentioned functions are provided at each of the power supply electrode 10' and the ground electrode 10'.

In this embodiment, the same effect as in the above-mentioned embodiment occurs and the same effect can be obtained.

FIG. 3 shows a third embodiment of the smear removal device according to the present invention, and 7A1 shows an embodiment of the present invention described above.
The difference from the diagram is that a plurality of power supply electrodes 10' and ground electrodes 20'' are used, and they are laterally opposed in the processing chamber 20' on the paternal side;
This is the point where the q number sequence is provided, and the printed circuit board 70 is
'ili Therefore, in this case, the exhaust hole 110" having the above-mentioned function is bored through the grounding wire.

In this embodiment, the same effect as in the above-mentioned embodiment occurs and the same effect can be obtained.

〔Effect of the invention〕

As explained above, the present invention enables the etching gas flowing along the surface of the printed circuit board to be drawn into the vicinity of the center of the opposite surface of the printed circuit board. ! By drilling an exhaust hole in the electrode facing the opposite side of the printed circuit board between the pole and the ground electrode, the strong gas plasma generated at the periphery of the printed circuit board can be drawn into the center of the flint board. Therefore, there is an effect that the etching 11t of the through holes in the center and peripheral parts of the flint base can be made more uniform and the uniformity of the etching distribution can be improved.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view showing an embodiment of the smear removing device according to the present invention, FIG. 2 is a vertical cross-sectional view showing a second embodiment of the smear removing device according to the present invention, and FIG. FIG. 7 is a longitudinal cross-sectional view showing a third embodiment of the smear removal device according to the invention. 10, 10', 10'...Power electrode, addition,
20', 20'... Ground electrode, 70...
・Printed circuit board, 110.110', 110'...
・・・Exhaust hole ゛・-2; 10

Claims (1)

[Claims] 1. In an apparatus for disposing a printed circuit board in a processing chamber provided with a power supply electrode and a ground electrode, and generating gas plasma while flowing an etching gas in the direction of the printed circuit board to remove smear in the through holes of the printed circuit board. ,
An electrode between the power supply electrode and the ground electrode that faces the opposite surface of the printed circuit board so that the etching gas flowing in correspondence with the surface of the printed circuit board can be drawn into the vicinity of the center of the opposite surface of the printed circuit board. A smear removal device characterized by having an exhaust hole.