SU996138A1 - Microwelding electrode - Google Patents

Description

one

The invention relates to pulse welding and can be used in the electronics industry for assembling semiconductor devices, film and hybrid circuits, printed circuit boards, etc.

In welding technology, electrode designs are known that are used for mounting by the method of one-sided contact welding of semiconductor device elements and integrated circuits, comprising a housing and two electrodes connected through an insulating gasket 1.

A disadvantage of the known tools is the inability to control the temperature in the weld zone and control the temperature mode of the weld.

Also known is an electrode for micro-welding, comprising a housing, a heating element, two working electrodes. The heating element is made in the form of a conductive film deposited on an insulating gasket and is insulated with a dielectric layer, while the thickness of the heating element does not exceed 0.3 width of the working end of electrode 2.

The disadvantage of this electrode is that it does not have a thermoelectric temperature control converter. This fact does not provide a stable welding process.

Closest to the invention is a micro-welding electrode, comprising a housing 5, current-carrying wounds, two working electrodes, a heating element made in the form of a film, insulating gaskets, current-carrying contact tracks and a thermoelectric converter 3.

A disadvantage of the known electrode is the low resistance of the electrode, as well as the low accuracy of temperature measurement in the weld zone due to the inconsistency of the thermal contact between the transducer, which reduces the stability of the welding process.

The purpose of the invention is to increase the resistance of the electrode and stabilize the welding mode.

Claims (3)

This goal is achieved by the fact that in a micro-welding electrode containing a 2Q body, current-carrying buses, two working electrodes, a heating element made in the form of a film, insulating gaskets, current-containing contact tracks and a thermoelectric converter, the latter is made in the form of an additional film deposited on the insulating gasket on the reverse side of the arrangement of the heating element. FIG. 1 shows an electrode for micro welding and a circuit for connecting it; in fig. 2 is a graph of thermoelectric converter resistance versus temperature. The electrode consists of a housing 1, made in the form of a dielectric ring of conducting busbars 2 and 3, two working electrodes 4 and 5, an insulating strip 6, on the lower part of which, on one side, a layer of heating film 7 is applied, and on the upper side there are two conductive contact tracks 8 and 9. On the other hand of the insulating gasket 6, a layer of thermoelectric converter film 10 is applied to the lower part, and two contact tracks 11 and 12 are applied to the upper part, touching the film of thermoelectric converter 10, to provide Grand contact. The heating film 7, the film of the thermoelectric converter 10 and a part of the contact tracks 8 and 9, 11 and 12, which are located under the current-carrying buses 2 and 3 and the electrodes 4 and 5 are protected by a dielectric layer 13 and 14. The current-carrying rails 2 and 3 are connected to pulse unit 15, contact tracks 8 and 9 - with a current source 16, and contact tracks 11 and 12 - with a thermoelectric converter unit 17. To eliminate breakage of the insulation strip 6 when the conductors are connected, a clip 18 is pressed onto the upper part of the current busbar 3. Electrode in pr during production welding compound works as follows. In the initial state, when the electrode does not touch the materials being welded, a current flows from the current source 16 to the heating film 7 through the contact tracks 8 and 9. The film 7 is heated and the thermal energy is transferred by the electrode 4 and 5 and the thermoelectric converter film 10. As the electrodes heat up, the resistance of the thermoelectric converter film 10 increases, which, via the contact tracks 11 and 12, is interconnected with the thermoelectric converter unit 17, which converts the increasing resistance in the electric circuit of a thermoelectric converter film into temperature change information. FIG. 2 shows that the change in the resistance of the film of the thermoelectric converter 10 is linearly dependent on the change in temperature. Next, the preheated electrodes 4 and 5 are lowered onto the surface of the wire to be welded 19, between the wire 19 and electrodes 4 and 5 an electrical contact is formed, through which a welding current pulse passes from block 15. When current passes through electrodes 4 and 5, the welded conductor 19 in it will be the heating temperature will increase rapidly, which in turn will proportionally increase the resistance of the film of the thermoelectric converter 10. The direct dependence of the resistance on the heating temperature allows the temperature of the welding mode, and when introduced between block 17 and feedback blocks 15 and 16, ensure that the selected temperature of the constant and pulsed heating of the electrodes is automatically maintained. A dielectric layer deposited on a thermoelectric converter protects it from weathering and electrical closure on electrode 5 and the current lead bus 3, and the location of the film thermoelectric converter between electrodes protects it from mechanical damage and increases corrosion resistance by 2 times compared to the closest prototype, whose thermocouple is a wire thermocouple attached to the outer surface of the electrode. In this electrode, thermocouple wires are broken off during operation and the thermal contact between the thermocouple and the electrode is broken. The use of an electrode with a film thermoelectric converter increases the resistance of the electrodes by 2 times, ensures the maintenance of the temperature mode of welding, which, in turn, when mounting the microcircuits, improves the quality of welding (connection strength) by 3% and the yield of ICs by 1.5%. The invention of the electrode for micro-welding, consisting of two working parts, the body of the current-carrying bus, a heating element made in the form of a film, insulating gaskets, a tube-carrying contact tracks and a thermoelectric converter, in order to increase the durability of the electrode and stabilize the welding mode, the thermoelectric converter is made in the form of an additional film located between the insulation strips. Sources of information taken into account in the examination 1. A. Krivoshey, A. Beltsev, Soldering and welding in the production of electronic equipment. M., “Energie, 1974, p., 211. 2. USSR author's certificate for application number 2932052 / 25-27, cl. At 23 K 11/24, 05/30/1980. 3. Mazur A.I., Alekhin V.P., Shorsherov M. Kh., Welding and brazing processes in the production of semiconductor devices. M., Radio and Communications, 1981, p. 198 (prototype).  S HV Fig a h 5a t 200 300 w 500 gs .2