SU1696215A1 - Method for thermal compression welding of miniature articles - Google Patents

Abstract

The invention relates to glososzarche and can be used by the P radioelectronic industry, in "efficacy in the production of permanent sampling devices. The purpose of the invention is the improvement of the quality of the welded joint. The method is carried out by heating two V-both electrodes with a current from the welding gnoformator. of each stage of the process, regardless of the moment of the occurrence of contact between the electrodes and the wire, and is determined by the specified time delay. The electrodes are connected in parallel through additional resistances with different values, i / ix, the heating is performed at different speeds and the charging is carried out in three stages using single-sided single-point thermo-compression welding by two-sided one eyeglass contact and one-sided - IJG two-hinge contact contact light. At the same time, the beginning of each stage is not set 1 a I automatically automatically as you see out and create a contact. Isolation is annihilated inhale year after year with another electrode 3 ii t

Description

/ 1 esr in the region of microsvarts, t in particular to the methods of thermocompressive welding; / myco-parts are predominantly covered with a layer of insulation, and can be used in various areas of radioelectronic

The circuit of the invention is to improve the quality of the welded joint by successively destroying the insulation layer under one and the second electrode.

FIG. 1 and 2 show the scheme for carrying out the method, not FIG. 3, a graph of voltage and current variations during the welding process.

The method is carried out as follows.

Fly 1, covered with insulation 2, the mouth is bored onto the parts 3 covered with solder 4, the nagrchker on the pad of the printed circuit board 5 Part 1 is pressed to the lower detaln 2 2 two V-shaped electrodes 6 and 7. The shoulders of the first electrode 6 are connected respectively with the dog output of the first additional resistance 8 and the second output of the second additional resistance 9, the second resistance terminals are connected to the corresponding terminals of the secondary winding of the transformer 10, to the primary winding of which through the control device 11 is supplied alternately voltage of 220 V, 50 Hz.

After turning on the transformer 10 and gradually increasing the voltage to

cl

nominal by program modulation, the electrodes are heated. At the same time, their heating rate depends on the value of the corresponding additional resistances 8 and 9. Provided that resistance 8 is significantly (30-40 times) greater than resistance 9, electrode 7 heats up faster. Its temperature T reaches the melting point of the insulation 2 (positions 1-3), as a result, under the electrode 7, the insulation 2 of the upper part 1 is destroyed, one-sided thermocompression welding occurs (Fig. 3, pos. 3 and 4), the upper part and the lower parts (pads) 3 of the printed circuit board 5. Subsequently, after the temperature Te of the second electrode 6 has reached the melting point of the insulation (Fig. D, pos. 1-4), destruction occurs under the electrode 6. Since by this time contact was made between electrode 7 and parts 1 and 3, the path changes When welding, resistance min 8 and 9. The current value increases dramatically, accelerated insulation breakdown and two-sided welding of parts under electrode 6 occur. As a result of complete insulation breakdown under both electrodes and ensuring contact with parts, double-point welding occurs (Fig. 3, pos. 5 and 6) and the formation of a welding core 12, after which the voltage supplied from transformer 11 to electrodes 6 and 7 is programmatically reduced and the current is turned off. Welding cycle completed

In the proposed method, the beginning of each position is not set, but started automatically, naturally, as the insulation breaks down under the electrodes and creates contact with the parts.

An example. The wires of the coils and the pads of the printed circuit board are welded with the following characteristics: Electrode material,

diameter, mmMolybdenum, 0.8

The distance between the electrodes, mm0,5

Material of additional resistances:

first Molybdenum

second nichrome

The ratio of the resistance of the electrodes 1:30

Type of wirePVTLK-0,08

Output voltage of the transformer, V1,5. After welding by the proposed method, a high quality welded joint was obtained.

Claims (1)

The invention of the method of thermocompressive welding of microdetails, predominantly coated with insulation, which simultaneously compress the welded parts, heat and destroy the insulation, and subsequent two-point welding with two V-shaped electrodes that are connected to a current source that differs from In order to improve the quality of the welded joint due to the successive destruction of the insulation under one and the second electrode, current of a different size is applied to each V-electrode, for which V-shaped el The electrodes are connected in parallel and various resistances are connected to the source. Yayo FIG. 2