Number of tin-plated terminals (semi-finished products, crimping wire) terminal by the riveting pressure wire - solder - then place two days later occurrence of the phenomenon of color yellow, why this happens then? Elinker terminals expert depth resolution welding terminal color of mystery.
View the color terminals, found that almost all terminals discoloration of the place are attached to the obvious, a large number of yellow adhesive material (suspected flux), it is a serious doubt caused for clients added the failure of the flux or flux in the solder terminal discoloration. Dissolved at high temperature, the flux will produce an acidic and corrosive substances, eventually leading to terminals change color?
Have experimented with multiple types of terminals to add a lot of flux, then solder, the day after the terminal solder around discoloration and surface residual flux from the color, sensory point of view and returned very similar.
Discoloration of the terminal for high-temperature aging test, and then use another no-clean liquid flux on the tin, place three days, non-color terminals.
The test can be obtained flux is more than rosin, color needs according to the actual analysis, the coating oxidation or coating is dissolved, the so-called color is exposed plating grass-roots or oxidation, so that you can explain to the terminal why discoloration.