JP2000119875A - Etching device for printed board and method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To uniformly execute etching of printed boards with high accuracy. SOLUTION: Many normal spray nozzles 19 are dispersedly arranged above a transporting device 4 for transporting the printed boards 50 at a constant speed and plural control spray nozzles 22 are arranged at prescribed intervals in a direction orthogonal with the transporting direction. The positions of the printed boards 50 under transportation are detected by a position detecting means 34 and the detection signals thereof are inputted to a controller 15. This controller 15 controls the spray periods of spray rates or spray quantity of the respective control spray nozzles 22 in response with the detection signals.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and a method for etching a printed board, and more particularly to an apparatus and a method for etching a printed board surface uniformly and with high precision.

[0002]

2. Description of the Related Art When a circuit pattern is formed on a printed circuit board in which copper foil is laminated on an insulating substrate, unnecessary portions of copper are usually removed by etching. In the conventional etching method, a method of spraying an etching solution on the surface of a printed board and etching copper in a portion not covered with a photoresist has been mainly used. In order to industrially implement such an etching method, there are many methods in which a printed board is placed on a transporting device that passes through the inside of the etching apparatus main body, and an etching solution is uniformly sprayed on a surface of the transported printed board.

However, when the etching liquid is sprayed uniformly on the surface of the printed board as described above, the etching liquid sprayed on the surface of the printed board collides with the surface and then flows from there. It has been found that the flow of the etchant at that time is greater at the peripheral portion than at the intermediate portion on the surface of the printed board. Conversely, the etching solution stays in the middle of the printed board. Therefore, the amount of etching in the intermediate portion is smaller than that in the peripheral portion, and there is a problem that it is difficult to perform uniform and highly accurate etching. In order to solve this problem, the present applicant has first described a two-stage etching method and an etching apparatus for etching the surface of a printed board by spraying an etchant in air and etching by jetting an etchant in the etchant. It has been proposed (Japanese Patent No. 2724354).

[0004]

According to the above-mentioned two-stage etching method, it is possible to etch a printed board uniformly and with high precision. However, implementing such a two-stage etching method still has a problem that the apparatus becomes complicated. Therefore, an object of the present invention is to provide an apparatus capable of etching a printed board with uniformity and high precision with a simple configuration, and a method using the apparatus.

[0005]

Means for Solving the Problems As a result of intensive studies conducted by the present inventor to solve the above-mentioned problems, when an etching solution is sprayed uniformly on the surface of a printed board from the upper side, the etching is performed at an intermediate portion of the printed board. It has been found that a stagnation phenomenon occurs in the etchant, resulting in non-uniform etching, and the present invention has been completed based on the finding. In other words, the printed board etching apparatus according to the first aspect of the present invention includes a transporting apparatus for transporting the printed board at a constant speed and a spraying apparatus for uniformly spraying the etching liquid over the entire upper surface of the printed board being transported. In order to spray a controlled etching solution onto a predetermined position on the upper surface of the printed board being conveyed, a large number of always-arranged spray nozzles are arranged in a row at a predetermined interval at least in a width direction of the conveyer above the conveying device. A control spray nozzle, position detecting means for detecting a position of the printed board being conveyed, and control for controlling a spray timing or a spray amount of the etching liquid from the control spray nozzle to the upper surface of the printed board based on the position detection signal. And a device.

According to the above apparatus, the spray liquid is constantly sprayed uniformly over the entire upper surface of the printed board being conveyed by the spray nozzle, and the controlled etchant is sprayed on a predetermined position on the upper surface, particularly at an intermediate portion thereof. can do. Therefore, it is possible to eliminate the phenomenon that the etchant stays in the middle portion of the upper surface of the printed board, and it is possible to perform uniform and highly accurate etching.

[0007] The invention described in claim 2 is the first invention.
And a plurality of control spray nozzles are provided at predetermined intervals in the direction in which the printed board is transported.
With this configuration, it is possible to cope with a large variation in the area of the printed board. In addition, the degree of freedom in adjusting the etchant sprayed on the intermediate portion is increased. Furthermore, the invention according to claim 3 is a preferred embodiment of the etching apparatus according to claim 1 or 2, wherein the etching liquid is sprayed uniformly on the entire lower surface of the printed board during transportation. A large number of spray nozzles are dispersedly arranged below the transport device. With this configuration, the present etching apparatus can be applied to a printed board in which copper foil is laminated on either one side or both sides of the substrate. On the lower surface of the printed board, there is no need to provide a control spray nozzle since the stagnation phenomenon of the etchant does not substantially occur in the intermediate portion.

According to a fourth aspect of the present invention, there is provided a method for etching a printed board using the etching apparatus according to any one of the first to third aspects. In this method, an etching liquid is constantly sprayed from a spray nozzle to at least the entire upper surface of a printed board being conveyed, and an etching liquid whose spray timing or amount is controlled by a control spray nozzle is provided at an intermediate portion of the upper surface. Is sprayed. According to the above method, it is possible to eliminate the stagnation phenomenon of the etchant in the middle portion of the upper surface of the printed board, and to perform uniform and highly accurate etching.

[0009]

Next, embodiments of the present invention will be described with reference to the drawings. 1 is a front sectional view schematically showing an example of the etching apparatus of the present invention, FIG. 2 is a sectional view taken along line AA of FIG. 1, FIG. 3 is a detailed front view of the etching apparatus, and FIG. FIG. 1 and 2, the apparatus main body 1 has an etching chamber 2 and an introduction chamber 3 for a printed board 50, and further has a printed board discharge chamber (not shown) on the opposite side of the etching chamber 2 from the introduction chamber 3. The transport device 4 for transporting the printed board 50 is of a roller conveyor type, and is installed linearly and continuously in the introduction chamber 3, the etching chamber 2, and the discharge chamber.

The transport device 4 has a plurality of lower rollers 5 arranged at a predetermined interval in the transport direction and a plurality of upper rollers 6 arranged at a wider interval in the transport direction. Each lower roller 5 is provided along the entire length in the transport direction, and is fixed at a predetermined interval to a plurality of lower shafts 7 arranged at right angles to the transport direction as shown in FIG.
Are fixed at predetermined intervals to the upper shaft 8 arranged at right angles to the transport direction. The lower roller 5 and the upper roller 6 have a relatively thin disk shape made of plastic and have a large number of flow holes for flowing the etchant in the axial through direction.

One end of the lower shaft 7 and one end of the upper shaft 8 are
And the other end is connected via helical gears 9 and 10 to two drive shafts parallel to the transport direction. Each drive shaft is gear-coupled to rotate synchronously in opposite directions, and is driven by a drive source 11 (FIG. 1) such as a reduction motor. That is, the pulley 12 is connected to the output shaft of the drive source 11, and the pulley 12 and a pulley (not shown) provided on one drive shaft are connected by the belt 13. The output shaft of the drive source 11 is provided with an encoder 14.
Is attached, and the output signal of the encoder 14 is input to the control device 15. (The operation of the control device 15 will be described later.)

In the etching chamber 2, a first spray means 16 is provided above the transfer device 4, and the first spray means 16 has an elongated main header 17 parallel to the transfer direction and a longitudinal length of the main header 17. It has a plurality of elongated branch headers 18 provided in the width direction at regular intervals in the direction, and a plurality of constant spray nozzles 19 attached at regular intervals in the longitudinal direction of each branch header 18. As a result, a large number of the spray nozzles 19 are constantly dispersed in the conveying direction of the conveying device 4 and in the width direction orthogonal thereto, at regular intervals, and as shown in FIGS. The etching liquid can be uniformly sprayed on the entire upper surface of the printed circuit board being overlapped and being conveyed. As shown in FIGS. 3 and 4, two rows of second spray means 20 are provided at predetermined intervals along the transport direction above the transport device 4 in the etching chamber 2. Each second spray means 20
Has an elongated support orthogonal to the transport direction and a plurality of control spray nozzles 22 attached at predetermined intervals in the longitudinal direction of the support. The number of control spray nozzles 22 in one row is always less than the number of spray nozzles 19. (Note that FIG. 2 shows the second spray means 2
To indicate 0, the first spray means 16 is omitted. )

Further, a transport device 4 in the etching chamber 2
The third spraying means 23 is provided below the space. Third
The spraying means 23 is constructed in the same manner as the first spraying means 16, and has an elongated main header 24 parallel to the conveying direction,
It has a plurality of elongated branch headers 25 provided at regular intervals in the longitudinal direction of the main header 24 in the width direction, and a plurality of constant spray nozzles 26 attached at regular intervals in the longitudinal direction of each branch header 25. As a result, a large number of spray nozzles 26 are dispersed at regular intervals in the conveying direction of the conveying device 4 and in the width direction orthogonal thereto, and the respective spray areas have their peripheral portions coinciding with or slightly overlapping with each other, and the The etching liquid can be uniformly sprayed on the entire lower surface.

A lower part of the etching chamber 2 is provided with a liquid stopper 27 for storing a predetermined amount of etching liquid.
The etching liquid 28 in 7 is controlled to a predetermined temperature by a heating device 29 such as a heater and a cooling device 30. As the cooling device 30, for example, a device having a cooling coil through which a coolant such as cooling water passes can be used. In the temperature control, a temperature signal of a temperature sensor (not shown) provided in the liquid holding device 27 is compared with a set value in the control device 15 to control a heating amount of the heating device 20 or a cooling amount of the cooling device 30. It is done by things. The etching solution 28 in the liquid retainer 27 is drawn out from a pipe 31 (FIG. 2) and is pressurized by a pressurizing pump (not shown).
7, 24, etc. Supply piping and main header 1
Opening / closing means such as an electromagnetic valve or an electric valve (not shown) is provided between the gates 7 and 24 so that the supply of the etching liquid to the header not used can be stopped. For example, the transport device 4
Is stopped, the supply of the etching solution to the main headers 17 and 24 can be stopped. When the lower spray is not performed, the supply of the etching solution to the main header 24 can be stopped.

As shown in FIG. 2, each control spray nozzle 22 of the second spray means 20 is connected to a plurality of control pipes 32 branched from an etchant supply pipe. The spray timing and the spray amount of the etching liquid of the control spray nozzle 22 are controlled by opening / closing means 33 such as an electromagnetic valve or an electric valve. In FIG. 1 again, a position detecting means 34 for detecting the position of the printed board 50 being conveyed is provided above the rear part of the introduction chamber 3 in the apparatus main body 1. Position detecting means 34
Is composed of, for example, a photoelectric switch, and outputs a detection signal to the control device 15 when the printed board 50 is present at the detection point (or while passing through the detection point).

FIG. 5 is a control block diagram of the control device 15. The control device 15 includes a counter unit 35 and two setting units 3
6, 37, and a power output unit 38, and a position detection signal from the position detection means 34 and an output pulse of the encoder 14 attached to the output shaft of the drive source 11 of the transport device 4 are input to the counter unit 35. You. The setting unit 36 sets the spray start position of the control spray nozzle 22 with respect to the printed board 50, and the setting unit 37 sets the end position. As the setting units 36 and 37, for example, a digital setting device such as a thumb rotary switch is used. Can be used. The power output unit 38 is composed of, for example, a thyristor device, and amplifies a control signal from the counter unit 35 to open and close each on-off valve 33.

Next, the operation of the above etching apparatus will be described. In order to simplify the explanation, the second spray means 2
Each control spray nozzle 22 at 0 operates only one row. First, the drive source 11 is started by a start switch or the like, and the transfer device 4 is driven at a constant speed. Further, the pressurizing pump is started, and the etching liquid 28 in the liquid retaining 27 is supplied from the pipe 31 to the first spray means 16, the second spray means 20, the third spray means 23 and the like. By opening the opening / closing means to the main header 17, the etching liquid is constantly sprayed uniformly from above the transfer device 4 from the spray nozzle 19, and by opening the opening / closing means to the main header 24, the etching liquid is always transferred from the spray nozzle 26. The etching liquid is sprayed uniformly from below the apparatus 4.

Next, when the drive source 11 is started, the encoder 14 rotates, and its pulse output is input to the counter section 35 of the control device 15. The rotation of the encoder 14 is exactly proportional to the travel distance of the transport device 4. Therefore, the integrated value of the pulse counted for a certain time coincides with the distance traveled by the transport device 4 within that time, that is, the distance traveled by the printed board 50 transported thereby. The leading end of the printed board 50 transported by the transport device 4 is positioned at the position detecting unit 3.
When the detection point 4 is reached, the detection signal (ON signal) is input to the counter section 35 of the control device 15, whereby the counter section 35 starts counting pulses of the encoder 14.

Since the distance from the detection point of the position detecting means 34 to the center of the row of the control spray nozzles 22 arranged in a row in the width direction is constant, the distance that the printed board 50 moves between them is the same as that of the pulse. It can be known from the count value. Therefore, if the count value corresponding to this distance is set as the equivalent count value, if the value set by the setting unit 36 is zero, the counter unit 35 reaches the equivalent count value, that is, the leading end of the printed board 50 is controlled. When the spray nozzle 22 reaches the center of the row, the counter 35
Outputs a control signal (ON signal). The control signal is amplified by the power output unit 38 to open and drive each of the opening / closing means 33, and the etching liquid is sprayed in a row from each control spray nozzle 22. Printed board 50 in setting section 36
When the distance from the tip of the counter, for example, a distance of 50 mm is set, when the count value of the counter section 35 reaches a value obtained by subtracting the pulse value corresponding to 50 mm from the equivalent count value, the counter section 35 A control signal is output. Therefore, the printed board 5 is set by the setting unit 36.
The spray start point by the control spray nozzle 22 can be set to zero.

The rear end of the printed board 50 is located at the position detecting means 34.
Is reached, the detection signal to the counter section 35 is turned off. Then, the counter section 35 starts counting pulses (length count value) corresponding to the length of the printed board in the transport direction, which is set and input in advance. Then, the distance from the rear end of the printed board 50, for example, 40
mm is set, the counter 35
When the count value reaches a value obtained by subtracting the pulse value corresponding to 40 mm from the equivalent count value, a control signal is output from the counter unit 35, and the control unit 37 controls the spray nozzle 22 on the printed board 50 by the setting unit 37. Spray end point can be set.

By providing the setting sections 36 and 37, the printed board 50 can be moved from the control spray nozzle 22 as described above.
The etching liquid sprayed on the upper surface of the substrate can be limited to an intermediate portion in the transport direction. By selectively operating only the middle portion of the row of the control spray nozzles 22 arranged in a row, the spray of the etching solution can be limited to only the middle portion in the width direction. In order to selectively operate the control spray nozzles 22 arranged in a row, for example, a selection switch may be provided on a control signal line or the like from the counter unit 35, and the control spray nozzle 22 to be operated by the selection switch may be selected.

As described above, the control spray nozzles 22 arranged in a row are operated only in the middle part in the width direction, and the setting of the setting parts 36 and 37 limits the spray range to the middle part in the conveyance direction. , Control spray nozzle 2
The etching liquid can be sprayed on the intermediate portion of the upper surface of the printed board 50 in the conveying direction and the width direction from 2. This intermediate portion has a size that eliminates the stagnation of the etchant on the upper surface of the printed board 50, and is determined by an experiment. In the case where the width of the printed board 50 is only one type, if the maximum width of the control spray nozzles 22 arranged in a row is set to a value suitable for an intermediate portion of the printed board 50 in the width direction, the control spray nozzle 22 The selection operation of 22 becomes unnecessary.

In the above example, the spray timing of the etching solution is controlled by controlling the opening / closing timing of the opening / closing means 33. However, the spray amount of the etching solution may be controlled instead. In that case, the row length of the control spray nozzles 22 is set so as to cover the maximum width of the printed board 50, and the spray amount is increased in the middle portion of the printed board 50 and reduced in the peripheral portion. Each control spray nozzle 22 is controlled. As the means, for example, an electric valve may be used for the opening / closing means 33, and the maximum operation opening may be made different between the middle part and the other end.

In the above example, the second spray means 2
Although the case where only one row of each control spray nozzle 22 is operated at 0 has been described, when two rows are used, the spray start position of the printed board 50 is set based on the row of the control spray nozzles 22 on the upstream side in the transport direction. The spray end position of the printed board 50 may be set based on the row of the control spray nozzles 22 on the downstream side in the transport direction. Further, when three or more rows of the control spray nozzles 22 are provided, the spray start position and the spray end position may be set accordingly.

[0025]

As described above, according to the printed board etching apparatus of the first aspect, the etching liquid is sprayed uniformly on the entire upper surface of the printed board being conveyed.
It is possible to spray more controlled etching liquid at a predetermined position on the upper surface, particularly at an intermediate portion thereof. Therefore, it is possible to eliminate insufficient etching due to the stagnation phenomenon of the etchant in the middle part of the upper surface of the printed board, to perform uniform etching over the entire surface of the printed board, and thereby to perform uniform and highly accurate etching. . Further, according to the printed board etching apparatus of the second aspect, it is possible to cope with a large variation in the area of the printed board. In addition, the degree of freedom in adjusting the etchant sprayed on the intermediate portion is increased.

Further, according to the printed board etching apparatus of the third aspect, the present etching apparatus can be applied to a printed board in which a copper foil is laminated on one side or both sides of a substrate. It is not necessary to provide a control spray nozzle since substantially no stagnation phenomenon of the etchant occurs on the lower surface of the printed board at the intermediate portion thereof. Claim 4
According to the method of etching a printed board described in the above, eliminating the phenomenon of stagnation of the etchant in the middle part of the upper surface of the printed board, it is possible to create a uniform flow of the etchant,
This enables uniform and highly accurate etching.

[Brief description of the drawings]

FIG. 1 is a front sectional view schematically showing an example of an etching apparatus of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a front sectional view showing a main part of the device in detail.

FIG. 4 is a sectional plan view of the same.

FIG. 5 is a control block diagram of a control device 15 in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Apparatus main body 2 Etching chamber 3 Introducing chamber 4 Transfer device 5 Lower roller 6 Upper roller 7 Lower shaft 8 Upper shaft 9 Helical gear 10 Helical gear 11 Drive source 12 Pulley 13 Belt 14 Encoder 15 Control device 16 1st Spraying means 17 Main header 18 Branch header 19 Constant spray nozzle 20 Second spray means 22 Control spray nozzle 23 Third spray means 24 Main header 25 Branch header 26 Constant spray nozzle 27 Liquid retaining 28 Etching liquid 29 Heating device 30 Cooling device 31 piping 32 control piping 33 opening and closing means 34 position detecting means 35 counter section 36 setting section 37 setting section 38 power output section 50 printed board

Claims (4)

[Claims] 1. A transport device 4 for transporting a printed board 50 at a constant speed, and a large number of dispersed devices arranged above the transport device 4 for spraying an etchant uniformly on the entire upper surface of the printed board 50 being transported. In order to spray a controlled etching solution onto a predetermined position on the upper surface of the printed board 50 being conveyed at all times, a plurality of spray nozzles 19 arranged at predetermined intervals in the width direction at least above the conveying device 4 are provided. A control spray nozzle 22; position detection means 34 for detecting the position of the printed board 50 being conveyed; and etching from the control spray nozzle 22 to the upper surface of the printed board 50 based on a position detection signal from the position detection means 34. A control device 15 for controlling a spray timing or a spray amount of a liquid, and a printed board etching device characterized by comprising: 2. The control spray nozzle 22 is mounted on the printed board 5.
The printed board etching apparatus according to claim 1, wherein a plurality of rows are provided at predetermined intervals in the zero transport direction. 3. The spray nozzle 26 according to claim 1, wherein a plurality of spray nozzles 26 are distributed below the transport device 4 in order to spray the etchant uniformly over the entire lower surface of the printed board 50 being transported. Printed board etching equipment. 4. The printing apparatus according to claim 1, wherein a spray nozzle is provided on at least the entire upper surface of the transporting printed board.
A spraying method for spraying an etching solution having a controlled spray timing or a spray amount from a control spray nozzle 22 onto an intermediate portion of an upper surface thereof.