/Pcb manufacturing requirements for flux performance
In order to fully utilize the role of the flux during the soldering process of pcba, the following requirements are imposed on the performance of the flux.
1.Has the characteristics of removing surface oxide, preventing reoxidation, reducing surface tension, etc., which is the basic performance that the flux must have.
2.The melting point is lower than that of the solder. Before the solder melts, the flux is melted firstly to fully exert its effect.
3.Wetting diffusion rate is faster than solder melting, usually requires expansion rate of more than 90%.
4 Viscosity and density are smaller than solder, the strong viscosity makes diffusion difficult, and the high density cannot cover the solder surface.
5.No spattering of tin beads occurs during welding, no toxic gas and strong irritating odor.
6.After welding, the residue is easy to remove and has characteristics of non-corrosive, non-hygroscopic and non-conductive.
7.Do not touch your hands after welding, it is not easy to form icicles
8.Storage is stable at normal temperature.
① Prepare a actual product surface soldered pcb assembly board . Because printed solder paste and the PCB assembly board without soldering cannot fix the test end of the thermocouple, it is necessary to use the soldered actual product for testing. In addition, the test sample cannot be used repea...
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