SU1555073A1 - Method of dip brazing in bath with molten solder - Google Patents

Abstract

The invention relates to soldering and can be used in various fields of engineering. The purpose of the invention is to increase the efficiency of removing oxides from the surface of the solder. Before the product is immersed in the molten solder, the oxide bath is removed from the bath mirror that is free of the soldered product, and the oxide layer is directed perpendicular to the direction of movement of the product by the flow of reducing gas formed by the flame. Before the flame is exposed to the surface, the solder temperature is lowered to a value that excludes the burning out of easily evaporating components from the solder. 3 hp F-ly, 1 tab., 4 Il.

Description

The invention relates to the field of soldering, and more specifically to methods of soldering by immersion in molten solder, and can be used in various fields of engineering.

The purpose of the invention is to increase the efficiency of removing oxides from the surface of the solder.

FIG. 1 shows a diagram of the implementation of the method when soldering with the movement of the product along the bath; FIG. 2 is the same when wave soldering; Fig. 3 is the same when soldering with a capillary-porous material; in fig. 4 - flame cooling element.

The method is carried out as follows.

During soldering (fig. 1), the soldered block is transported over bath 1, brought into contact with the molten solder 2 and removed from the zone of the bath 1 in the free zone of the soldered block in the plane adjacent

to the surface of the solder 2, perpendicular to the direction of movement of the block on the surface of the molten solder 2, is affected by a reducing flame 3 "The front of the reducing flame 3 can be moved in front of the block. The time of influence of the reducing flame on the surface of the solder is within 2-5 seconds

In order to obtain the front of the reducing flame 3, combustible gas is injected through the nozzles 4 and ignites it. In this case, the flow of the reducing flame is partially removed from the surface of the solder 2 waste — oxides and other products formed during the soldering process. Under the influence of the gas flow, they are displaced to the side wall of the bath 1, and along an inclined wall fall into the waste collector.

In addition, during the time of 2-5 s, the surface layer of oxides under the action of a reducing flame was restored (L

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is cast. With a shorter exposure time, the recovery effect is not visually observed. When exposed to the surface of the molten surface for more than 5 seconds, the cleaning quality is improved. However, solder overheating is possible and the temperature in the bath is complicated. Therefore, a cleaning time of 2-5 seconds is optimal.

The table shows examples of the method applied to the following process parameters: the composition of a mixture of city gas - air, the rate of gas outflow from the nozzle 10 m / s, the height of the gas supply slot 2 mm s

During wave soldering (FIG. 2), the front of the reducing flame from the nozzle 4 is directed to the surface of the wave below the ridge along it forming at least its upward side.

Under the influence of the gas flow, waste generated during the soldering process, trapped by the solder wave 2 and located on its outer surface, is removed. The oxides are partially reduced. This also facilitates the process of soldering due to the entry into the soldering zone of a non-oxidizing environment.

When soldering using capillary-porous material and working

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whose surface in the form of a cylinder (Fig. 3), the front of the reducing flame 3 from the nozzle A is directed along the generator cylinder 5 "On the surface of the solder 2 protruding above the capillary-porous material 6, waste is generated. In this case, the action of the reducing flame is similar to the examples considered.

In order to prevent evaporation of solder components before flame is applied to its surface, the flame temperature is reduced to a value at which no evaporation of solder components occurs, for example, when natural gas mixed with air is used to form a reducing flame, the temperature is reduced from 1100 to 600 ° C In this case, a decrease in the temperature of the flame front can be achieved by interacting it at the exit of the nozzle 3 with cooling elements 7, equipped with a lining 8 of heat-resistant material, and the base 9 of a material with high thermal conductivity

The use of the proposed soldering method makes it possible to increase the efficiency of removing oxides from the surface of the solder due to the pressure of the gas reducing flow formed by the flame.

Claims (1)

1. A method of soldering by immersion in a bath with molten solder, including the removal of oxides from the surface of the solder in a reducing atmosphere, characterized in that, in order to increase the efficiency of removing oxides from the surface of the solder, the reducing atmosphere is supplied as a flame to the surface of the solder in an area free from of the fallen product, perpendicular to the direction of its movement 2 "Method according to claim 1, characterized in that, in order to prevent evaporation of solder components, before applying flame to its surface, the flame temperature is reduced to a value at which no evaporation of solder components occurs. 3 The method according to p. 1, characterized in that when brazing with moving the product along the bath, the front of the reducing flame is moved in front of the pasted product, and the time 515550736 the effect of the flame on the surface of the wave (stream) solder to the front of the reducing flame is directed to the surface of the wave below its crest 4. Method pop. 1, different, along its generatrix, at least least, with the fact that, when paiken its upstream side. solder set within 2-5 s. A'E3 Q : ABOUT FIG. Z ag.1 V Fi.g.3 9 FIG.