JPS5825479A - Etching device - Google Patents

Abstract

PURPOSE:To perform etching uniformly at a high speed by disposing plate bodies which are punched with many through-holes and are formed with openings communicating with the inside suction hole cavities in proximity to the plate to be worked. CONSTITUTION:A sealed etching tank is constituted of casings 12, 12', and the inside of the tank is divided to two chambers 16, 16' by an object to be worked, for example, a printed wiring board 14. When an etching soln. is fed forcibly through the introduction port 12a of the casing 12 into an arrow (a) direction, the soln. passes through the through-holes 18a which are punched in a large number in the 1st dispersion plate 18 and abuts on the 1st surface of the board 14, thereby etching said surface. The soln. is sucked through the fine holes 22b formed in the 2nd dispersion plate 22 as shown by arrows (b). The waste etching soln. sucked in hole cavities 22c through the holes 22b is filtered and regenerated. To etch the other surface of the board 14, the etching soln. is introduced through the introduction port 12'a of the casing 12'.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an etching apparatus, and more particularly to an apparatus for performing etching at high speed and uniformly.

The etching process performed by the apparatus of the present invention is primarily intended for printed wiring boards, and therefore the present invention will be described in connection with this.

Conventionally, a so-called spray method has been mainly used for etching printed circuit wiring boards, in which a corrosive liquid is sprayed from a nozzle onto the printed circuit board being transferred on a roller conveyor. According to this conventional method, the sprayed corrosive liquid reacts with the copper in the area to be etched and is inactivated, and then a new corrosive liquid is sprayed. This method has a defect in that the activity of the etching solution is inhibited by the presence of the etching solution that has been sprayed first and is in an inactive state, thus making it difficult to perform a quick and uniform etching process.This defect can be overcome. In order to do this, it has been proposed to increase the spray pressure, but in this case as well, film removal cannot be achieved because of the concept of waiting for the reacted etchant to flow away. It was not possible to significantly reduce the time required.

It is therefore a principal object of the present invention to provide an apparatus for etching processes which completely avoids and overcomes the deficiencies mentioned in prior art apparatus.

A specific object of the present invention is to provide a simple and inexpensive apparatus in which an etchant is circulated and a workpiece can be etched at high speed.

These objects of the invention, as well as other advantages which will become apparent from a fuller understanding of the invention, and the advantages achieved by the invention, will be discussed in conjunction with the embodiments illustrated in the accompanying drawings. It will become clear from the detailed description below.

In the accompanying drawings, FIG. 1 illustrates one embodiment of the apparatus of the present invention for etching both sides of a printed wiring board. In the apparatus, generally designated by the reference numeral 10, 12.121 respectively designate the housing halves constituting a closed etching tank, the space within which is used for printing the workpiece. It is divided into two chambers 16 and 16'K by a wiring board 14. A corrosive liquid is press-fitted into the chamber 16 from an inlet 12a provided in the housing half 12 as shown by arrow a. The injected corrosive liquid passes through the pores 18a formed in the first distribution plate 18, passes through the holes 22& formed in the second distribution plate 22, and comes into contact with one surface of the printed wiring board 14. The surface of the substrate 14 is then etched, and the pores 22b formed in the surface of the second dispersion plate 220 opposite to the surface to be etched of the substrate 14 are etched, as shown by the arrows. It is then aspirated. The waste corrosive liquid sucked into the cavity 22e from the pore 22b is collected in a conventional manner, filtered, regenerated, and then returned to the chamber 16 from the inlet 12a via a pump (not shown). can be press-fitted inside.

On the other hand, a first dispersion plate 18 and a second dispersion plate 22 similar to those in the chamber 16 are provided in the chamber 16'.
An etchant is forced into the chamber ea to etch the other surface of the substrate 14, but the manner in which the etchant circulates is exactly the same as in the chamber 16, so a description thereof will be omitted.

Note that if etching is required on only one side of the printed wiring board 14, it goes without saying that the etchant only needs to be injected into one of the chambers 16 or 16'.
In this case one housing half (12 or 12°) and the associated elements (18 and 22
, or is' and 22') can be omitted.

Furthermore, although both housing halves 12 and 12' have been described together as forming a closed etching tank, it is not necessary that the apparatus shown in FIG. 1 be constructed in a closed manner. That is, FIG. 1 is a partial vertical sectional view showing one embodiment of the device of the present invention, but this will become clear if it is assumed that FIG. 1 is a cross sectional view of the device viewed from above. In this case, the printed wiring board 14 is connected to the housing halves 12 and 12'.
The first and second dispersion plates 18.181.2
2.22' can be subjected to a predetermined etching process while suspended from a suitable support structure (not shown).

FIG. 2 shows a second embodiment of the apparatus of the present invention for etching a printed wiring board. In this device 100,
112 is a box constituting an etching tank;
8.122 corresponds to 18.22 in FIG. 1 and has a similar structure, and 124 is the first and second distribution plate.
This is a lid body that suppresses the ejection of the corrosive liquid that is press-fitted into the corrosive liquid.

The printed wiring board 114, which is the workpiece, is suitably mounted on a support (
(not shown), and the part to be treated is immersed in the corrosive liquid through a suction (not shown) 124a formed on the lid 124.

The corrosive liquid flows into the housing 112 from an inlet 112a formed in the housing 112 (see arrow a), passes through the first and second dispersion plates 118, 1227, and flows toward the lid 124, where it flows onto the printed wiring board 114. After being subjected to the etching process, it is sucked and discharged from the casing 112 through the pores 122b provided in the second dispersion plate 122. The discharged corrosive liquid can be regenerated, if necessary, and then circulated to the inlet 112a, as described in connection with FIG. 1.

Figure 3 shows a long flexible printed wiring board, i.e. conventional RO
This figure shows an outline of the casing of the apparatus of the present invention, which is used when etching a printed wiring board that has been etched using the To-Ro11 method.

The housing has one half 312 and the other half 312', each half having an inlet 312a through which the corrosive liquid is introduced.
, 312'a, and the connecting flange portion 312b, 3
1Sfb. Both flange parts 312b, 3
12'b is clamped by an appropriate clamping means (not shown) to prevent the corrosive liquid introduced into the case from leaking to the outside; The flange portions forming the recessed portion and the retracted portion are slightly spaced apart from each other.

The flange portions 312b, 312'b where the separation portion exists are provided with a gutter groove 312c for accommodating the elastic strips 316, 31d.
, 312'c are formed so that the tops of the elastic strips come into pressure contact with each other to prevent liquid leakage.

The elastic strips 316, 316 can be made of an elastic material that is stable against corrosive fluids, for example synthetic rubber.

Incidentally, when the casing shown in FIG. 3 is used for etching treatment, the first dispersion plate 18 or 181 shown in FIG.
and a second distribution plate 22 or 221 is attached to each housing half.

The invention will now be explained in more detail with reference to examples.

Using the equipment shown in Figure 1, a double-sided printed wiring board (200 x 200 m) with a thickness of 35 μm was installed.
Etching treatment was carried out at room temperature using 42° Baume iron chloride solution as an etchant using two pumps running at 2004/min.

When processing 5 sample substrates, the average time required was approximately 5 minutes.
It was 0 seconds.

[Brief explanation of the drawing]

In the accompanying drawings, FIG. 1 is a partial vertical sectional view showing the first embodiment of the device of the present invention, FIG. 2 is a drawing similar to FIG. 1 showing the second embodiment, and FIG. 1 is a schematic longitudinal sectional view of a body part, showing a housing structure suitable in particular for processing elongated fugitive printed circuit boards; FIG. Box body・・・・・・・・・・・・12.12'
; 112.124; 312, 312' Plate to be processed...14; 114;
314 (Printed wiring board) Corrosive liquid・・・・・・・・・Plate without reference code Body・・・・・・・・・・・・22, 22;
122 (Second dispersion plate) Through hole of second dispersion plate 22 & suction hole cavity 22e Suction hole cavity Communicating sliding opening......22b Port 122b Patent applicant: Sawahama Giken Co., Ltd., agent patent attorney 1) Black Oil amount: 1/1\6'

Claims (1)

[Claims] An etching device comprising a case and a plate to be processed disposed within the case, and which processes the plate to be processed with a corrosive liquid in the case, in which a large number of through holes are bored. An etching processing apparatus characterized in that a plate body having an opening formed on one surface communicating with an internal suction hole cavity is disposed in close proximity to the plate body to be processed.