/Pcb manufacturing solder paste selection principle
There are many types and specifications of solder paste in Pcb manufacturing plants. Even the solder paste used by the same Pcb manufacturer in printed circuit boards has differences in alloy composition, particle size, viscosity, cleaning method, etc., and price varies greatly. How to choose the suitable Pcb manufacturing solder paste has a great impact on product quality and cost.
Generally, it should be selected according to the specific production environment, with reference to the activity, viscosity, powder shape, particle size and melting point of the solder paste.
The choice of solder paste in Pcb manufacturing should determine the alloy composition firstly. The alloy is a solder-forming material that forms an alloy layer with the interface of the metal being welded, and the alloy composition also determines the soldering temperature, so the alloy composition should be determined firstly. The alloy composition is mainly selected according to the electronic products and technics. The alloy composition compatible with the component welding should be selected as much as possible, and the technics factors such as the welding temperature should also be considered.
Reasonable selection of flux in Pcb manufacturing solder paste. The printability and solderability of the solder paste mainly depend on the flux in the solder paste. Therefore,once determining the alloy composition in the solder paste, the flux suitable for the production technics should be selected.
When selecting, it is necessary to select the activity according to the storage time of the printed circuit board and components and the degree of surface oxidation: the general product adopts RMA type; the high reliability product selects R type; the printed circuit board and components are stored for a long time, and the surface is seriously oxidized.In this case RA type should be cleaned after welding.Determine the ratio of the alloy composition to the flux in the solder paste produced by Pcb. The ratio of alloy composition to flux directly affects the viscosity and printability of the solder paste.
The viscosity of the solder paste is selected according to the technics of applying the solder paste and the assembly density of the Pcb. There are many ways to apply solder paste, and different application methods have different requirements on the viscosity of the solder paste.
The above is the industry information provided by FASTPCBA, I hope to help you!
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