KR20020001973A - Apparatus for auto-controlling pressure of etching solution with vision system - Google Patents

Abstract

PURPOSE: An apparatus for automatically controlling a spray pressure of etching liquid with an image system is provided to control the rate and quantity of etching liquid sprayed to the surface of a material. CONSTITUTION: An image system takes a picture of the surface of a material(8) from which photoresist is eliminated, and acquires digitalized image data. A proportional control valve(2) is so installed in a pipe connecting an etching cell(6) with an etching liquid tank(7) that the proportional control valve controls the rate and quantity of etching liquid sprayed from an etching liquid spraying nozzle supplied to the pipe up to the surface of the material. A control unit(15) compares a width value of a line and space of the material with a previously-inputted permissible value through image data acquired by the image system to uniformly etch the material and control switch-on/off of the proportional control valve. The control unit is electrically connected to the image system and the proportional control valve, respectively.

Description

Apparatus for auto-controlling pressure of etching solution with vision system}

The present invention relates to an automatic control apparatus for etching liquid injection pressure having an imaging system. More particularly, the present invention relates to a semiconductor assembly such as a lead frame or a printed circuit board by automatically adjusting the spray pressure of the etching liquid injection nozzle using the imaging system. The present invention relates to an apparatus capable of maintaining a uniform degree of etching of necessary materials.

In general, controlling the etching rate of the material is very important to uniform the line and the margin width in the lead frame or the printed circuit board because it causes a vertical or horizontal deviation in the material. Since the etching rate is very sensitive to the injection pressure of the nozzle, the etching rate can be generally controlled by finely controlling the injection pressure. In order to control the injection pressure of each part of the material, the etching rate must be measured at each position. Until now, this work has been performed off-line, and as described above, a lot of time and material loss have occurred, I could not cope actively.

US Pat. No. 5,002,627 (Scheithauer et al.) Discloses a device that can obtain a constant pattern despite the thickness change of the material by measuring the thickness of the material prior to etching and controlling the spray pressure of the nozzle based on this. However, since such an apparatus is to measure the thickness of the material before etching, it is possible to overlook other important factors in etching.

Accordingly, the present invention has been made to overcome the above-described problems, and an object of the present invention is to provide an etching liquid injection pressure having an imaging system capable of realizing uniform etching quality of materials required for assembling semiconductors such as lead frames or printed circuit boards. It is to provide an automatic control device of.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a side view schematically showing an automatic control apparatus for etching liquid injection pressure provided with an imaging system according to the present invention.

2 is a plan view of FIG.

<< Description of main part of drawing >>

1: Pressure instrument 2: Proportional valve

3: pump 4,5: manifold

6: etching cell 7: etching liquid tank

8: Material 9: PR removal cell

10 PR removal liquid tank 11: CCD camera

12 Terminal Block 13: Frame Grabber

14: data acquisition board 15: computer

The object of the present invention is to remove the surface and PR of the material by the pressurized etching solution and PR removal liquid while the material continuously passes through the etching cell and PR removal cell having an in-line sealed structure, PR is removed An imaging system for photographing the surface of the material to obtain digitized image data; A proportional control valve provided in the piping to adjust the speed and the amount of the etching liquid injected onto the surface of the material from the etching liquid injection nozzle provided in the piping connecting the etching cell and the etching liquid tank; It is electrically connected to the imaging system and the proportional control valve, and inputs the value of the width of the line and the space of the material through the image data collected by the imaging system to maintain a uniform etching degree of the material. It can be achieved by the automatic control of the etching liquid injection pressure having an imaging system comprising a control means for adjusting the opening and closing degree of each proportional control valve compared to the allowable value.

Here, the imaging system includes a CCD camera spaced apart on at least one surface of the material etched to photograph the surface of the material, and a frame grabber for converting the photographed image from the CCD camera into digitized image data.

The control means is a computer incorporating a frame grabber.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a side view schematically showing an apparatus for automatically controlling etching liquid injection pressure provided with an imaging system according to the present invention, and FIG. 2 is a plan view of FIG.

1 and 2, the automatic control device according to the present invention is a uniform etching degree of the material (hereinafter referred to as "material") 8, such as a lead frame or a printed circuit board coated with PR (Photo Resist) An imaging system including a CCD camera 11 and a frame grabber 12 and a DAB (Data Acquisition Board (PLC)) 14 for photographing the surface of the material 8 to implement the And a control means 15 such as a computer for analyzing the data and controlling the opening and closing degree of the proportional control valve 2 provided at the connection portion between the etching liquid tank 7 and the etching cell 6.

The imaging system is configured to capture at least one or more surfaces of the material 8, such as a reel-to-reel type lead frame or a printed circuit board in a strip state, so that at least one or more surfaces of the material 8 are completely removed. And a frame grabber 13 for converting the surface image of the material photographed by the camera 11 into digitized image data. Here, the frame grabber 13 is embedded in a control means 15 such as a computer.

The surface image of the material 8 obtained in the present imaging system is the width of the line and the space, where the line is the iron portion as the remaining portion by etching, and the space is the yaw removed by the etching. Part. That is, the image photographed by the CCD camera 11 is transmitted to the control means 15 as digitized image information through the frame grabber 13, and compared with the previously input allowance.

The present invention is applied to the embodiment in which the etching cell 6 and the PR removing cell 9 are installed inline, and the etching tank 7 and the PR removing tank corresponding to each of the etching cell 6 and the PR removing cell 9 are corresponding thereto. It is connected by the pipe 10 and the solutions stored in each of the tanks 7 and 10 are pressurized to a proper pressure by the pump 3. Here, the etching cells 6 are composed of two or more, and each of the etching cells 6 is generally provided with four manifolds 4 and 5 on the upper and lower sides and the left and right sides of the etching cells 6. The number can vary depending on the thickness and width of the material and the etching conditions.

In addition, after the material 8 has passed through the etching cell 6, the PR attached to the material surface is removed and the surface is photographed by the imaging system described above. 1 and 2 omit water washing and drying cells attached to the etching cell 6 and the PR removing cell 9, respectively.

In the piping connecting the etching cell 6 and the etching liquid tank 7, the pressure instrument 1 is provided to indicate the pressure of the proportional control valve 2 and the solution and to transmit the pressure value to the control means 15, respectively. . Therefore, as described above, when the PR 8 is completely removed and the water washing and drying are completed, the width of the line and the space is clearly photographed by the CCD camera 11, for example, at least one surface or more, so that the control means ( 15), and according to the result, it is configured to realize the uniform etching degree of the desired material 8 by determining the injection pressure of the most preferable etching liquid and adjusting the proportional control valve 2 described above.

Since the etching rate of the material 8 is closely related to the injection pressure (injection rate, injection amount) of the etching liquid sprayed on the surface of the material 8, in the present invention, the surface of the material 8 on which the etching is completed is photographed and based on it. By adjusting the proportional control valve 2 in real time, the proper injection pressure (injection speed, injection amount) of the etching liquid sprayed on the surface of the actual material 8 was maintained to maintain the etching degree of the desired material. Here, reference numeral 12 is a terminal block. Terminal blocks and DABs can be replaced with PLCs.

Here, as the etching proceeds, the widths of lines and spaces change for various reasons. In principle, the thickness of the material 8 is improved and constant, but if a portion is slightly thick, the line / space ratio becomes large even at the same etching rate in that portion, and in the thin material, the opposite phenomenon is caused. In addition, when the nozzle is clogged by the electrolyte, PR residues, or the like as the etching proceeds, the flow rate of the etching liquid decreases and the etching rate decreases, thereby reducing the line / space ratio.

On the other hand, since the etching solution generally maintains a temperature of 50 ° C. or more, the nozzle used for a long time gradually widens the orifice, thereby increasing the flow rate and thus increasing the line / space ratio. For these reasons, the widths of lines and spaces continue to change little by little during the etching process. therefore. According to the present invention, a proportional control valve (2) is measured in the case of over-etching by measuring the material (8) in which the etching process is completed in real time through an imaging system and comparing it with the allowable value inputted to the control means (15) based on this value. By adjusting the amount of etching liquid injected from the etching liquid injection nozzle, and vice versa, it is possible to maintain the etching degree of the desired material by adjusting the proportional control valve 2 to increase the injection amount of the etching liquid.

The structure of the present invention described above adjusts the speed and the amount of the etching solution sprayed on the surface of the actual material by measuring the width of the line and space of the material after the etching process is completed in real time by controlling the proportional control valve corresponding thereto. By doing so, there is an effect of maintaining a uniform etching degree.

Claims (3)

In the apparatus for removing the surface and PR of the material by the pressurized etchant and PR removal liquid while the material continuously passes through the etching cell and PR removal cell having an in-line sealed structure, An imaging system for photographing the surface of the material 8 from which the PR has been removed to obtain digitized image data; Proportional control valve (2) provided in the pipe to adjust the speed and the amount of the etching liquid injected to the surface of the material (8) from the etching liquid injection nozzle provided in the pipe connecting the etching cell (6) and the etching liquid tank (7) Wow; A line of material (8) through the image data obtained by the imaging system, each electrically connected to the imaging system and the proportional control valve (2), to maintain a uniform degree of etching of the material (8). And control means (15) for adjusting the opening / closing degree of each proportional control valve (2) by comparing the value of the width of the space with the preset allowable value. 2. The imaging system according to claim 1, wherein the imaging system includes a CCD camera (11) spaced apart from at least one surface of the material (8) etched to photograph the surface of the material (8) and a photographed image from the CCD camera (11). And a frame grabber (13) for converting the image into digitized image data. 3. The apparatus of claim 2, wherein the control means (15) is a computer incorporating the frame grabber (13).