SU1563789A1 - Method of electrolytic cleaning of articles - Google Patents

Abstract

The invention relates to the electrolytic cleaning of wafers, which makes it possible to improve the quality and productivity of the cleaning. The plate to be cleaned is mounted on a centrifuge 6, fixed with a vacuum created in channel 8, and brought into rotation. The tank 2 is filled with the electrolyte solution, using the pump 3, the electrolyte is fed through the nozzle 10 onto the surface 7 of the plate 7. The collector 9 with gaskets 13 and 14 installed on it is lowered until the gaskets 13 and 14 touch the plate 7 and are reciprocating . The gaskets 13 and 14 supply the potential from the current source 16. As a result, a cathode occurs under one gasket, anode electrolytic etching occurs under the other gasket, and between the gaskets an electrolyte evolves, producing gases that cause the cavitation layer to rotate. Thereafter, reversing the polarity of the direct current by the current source 16 is performed to reduce the erosion of the upper metal layer when processing the metallized substrates. During cleaning, the plate is rotated with infinitely variable rotation frequency in the range of 400-8000 rpm, and the electrodes, installed coaxially with the axis of rotation of the product, smoothly move in the radial direction from the axis of rotation to the periphery. The electrolyte is fed parallel to the axis of rotation in the central zone. 2 hp f-ly, 2 ill.

Description

 H

QNfY

-g

Fy

channel 8 and is rotated. The tank 2 is filled with the electrolyte solution, using the pump 3, the electrolyte is fed through the nozzle 10 onto the surface 7 of the plate 7. The collector 9 with gaskets 13 and 14 installed on it is lowered until the gaskets 13 and 14 touch the plate 7 and are reciprocating . Gaskets 13 and 14 are supplied with potential from current source 16. As a result, cathode occurs under one gasket, anodic electrolytic etching is carried out under another, and an electrolyte is released between gaskets, with the release of gas. , for example, semiconductor, dielectric substrates of film microboards.

The aim of the invention is to improve the quality and productivity of cleaning.

FIG. 1 shows a diagram of a device that implements the proposed method, an axial section; in fig. 2 is a section A-A in FIG. one.

The device comprises a bath 1, a tank 2 for collecting electrolyte flowing out of the bath, a pump 3, a filter 4, a piping system 5, a centrifuge 6 on which plate 7 is installed. A vacuum channel 8 is placed along the axis of the centrifuge. The centrifuge is reciprocally mounted a collector 9 containing a nozzle 10 connected to the discharge line of the pump 3 via channel 11. The collector 9 is made with a conical inner surface 12. On the collector 9 there are gaskets 13 and 14, made of porous dielectric one material in the form of an Archimedean spiral, and the gaskets 13 and 14 are electrically insulated from one another dielectric insert 15. Gaskets 13 and 14 are electrically connected to a source of current nnrogo 16 adapted to operate in an alternating mode.

The proposed method is implemented as follows.

The plate to be cleaned is mounted on a centrifuge 6, secured with a vacuum created in channel 8, and brought into rotation (indicated by an arrow). Tank 2 is filled with electrolyte solution. Using the pump 3, the electrolyte is fed through the nozzle 10 onto the surface of the plate 7 being processed. The collector 9 with the gaskets 13 and 14 installed on it is lowered until the gaskets 13 and 14 touch

call, creating a cavitation layer during plate rotation. Thereafter, reversing the polarity of the direct current by the current source 16 is performed to reduce the erosion of the upper metal layer when processing the metallized substrates. During cleaning, the plate is rotated with infinitely variable rotation frequency in the range of 400-8000 rpm, and the electrodes, installed coaxially with the axis of rotation of the product, smoothly move in the radial direction from the axis of rotation to the periphery. The electrolyte is fed parallel to the axis of rotation in the central zone. 2 h. item f-ly, 2 ill.

with plate 7 and is brought in reciprocal movement (indicated by arrows). On the gaskets 13 and 14 serves the potential from the source 16 current. As a result, under one of the gaskets, a cathode occurs, and under the other, anodic electrolytic etching occurs, between the gaskets, an electrolyte with evolution of gases, which create a cavitation layer as the plate rotates. Thereafter, reversal of the polarity of the direct current by the current source 16 is performed to reduce the erosion of the upper metal layer during the processing of the metallized substrates. Example. The method is implemented on a hydromechanical washing machine that incorporates automatic loading and unloading of cassettes with blanks (48X60X0.6 mm), a working position with a centrifuge, a collector for feeding working reagents, deionized water and nitrogen, an electrolytic cleaning unit, a bath with a mechanism vertical reciprocating movement, recirculation hydraulic unit with a pump with a capacity of 1 m3 / h with a heater, level, density, temperature and filter pollution sensors, cans for detergents Create and deionized water from

5 of which fluids are displaced by an overpressure of nitrogen, a PI-50 power source having current parameters: in a stabilized mode — 1 A, in a pulsed mode — 10 A. The power source includes a programmer.

0 Preparations after unpacking from the enterprise packaging are made by the manufacturer in cassettes (25 pieces each). The cassettes are placed on the loading table of the cassette unloading mechanism. From it, blanks are individually supplied to the vacuum cartridge of the centrifugal fugue. The electrolytic purification unit is injected into the interaction with the workpiece, at the same time the hydraulic unit is turned on, which ensures the filling of the bath 1 to

level and constant supply of electrolyte to the treatment area. With an interval of 1 s after the start of operation of the hydraulic unit, the rotation of the centrifuge begins at a speed of 400 rpm. At the same time, the power supply is turned on in a stabilized mode with the current density on the surface of the workpiece 4 A / dm2 being provided and the electrolytic cleaning unit (collector 9) begins to move parallel to the surface of the workpiece. In this mode, processing is carried out for 10 s, and by the end of this period, the rotation frequency of the centrifuge smoothly increases to 16600 rpm. After that, the programmer translates the power source B in a pulsed mode with a current density reaching up to 40 A / dm5 in the extremum of the pulse, and the rotational speed of the centrifuge for the next 8 s increases to 8000 rpm. The increase in the number of revolutions goes smoothly, in proportion to the duration of the increase period. When machining blanks with a deposited metal layer (chromium, vanadium), the programmer is tuned to the polarity reversal mode during the last 2 seconds of the machining cycle with a stabilized current. Thereafter, the electrolytic processing unit is brought out of contact with the workpiece, the hydraulic unit is turned off, the power source is switched to standby mode, and the drain channels to the hydraulic unit are blocked by hydrovalves. A cleaning solution is fed to the surface of the workpiece at a centrifuge speed of 400 rpm. Processing takes 3 seconds. The speed is then increased to 6000 rpm and deionized water is supplied to the surface of the workpiece for 5 seconds. Thereafter, the number of revolutions increases.

BUT

73

0

five

0

five

0

up to 8000 rpm and the preform is blown with heated, dried nitrogen for a second and fed to the cassette.

The cleaning by the proposed method allows to significantly improve the cleaning performance with high quality. The adhesion of the sprayed layer of this cleaning is much higher than after cleaning by known methods.

Claims (3)

1. An electrolytic cleaning method for products, mainly microplates, consisting in that electrodes are placed above the product surface, and strips of porous dielectric material are placed between the electrodes and the product, they are pressed through the electrodes, the electrolyte is applied to the product surface and a current is passed that differs in that, in order to improve the quality and productivity of cleaning, the spacers are arranged along an Archimedean coil, the product is rotated during cleaning, and the electrodes are smoothly moved from the axis of rotation to periphery. 2. A method according to claim 1, characterized in that the supply of electrolyte is parallel to the axis of rotation of the product in its central zone. 3. Method according to paragraphs. 1 and 2, characterized in that during the rotation of the product, an infinitely variable rotation frequency in the range 400--8000 rpm is made.