Solder pasteAsSMTAn indispensable part of the production process, the particle size of tin powder in solder paste, the proportion of metal content, the content of flux, the stirring time, the temperature recovery time, as well as the placement and storage time of solder paste will all affect the final printing quality of solder paste. The following is an explanation from the solder paste manufacturer:

SMTThe components of specialized solder paste are generally divided into these two categories, namely solder powder alloy and flux.

The composition and function of alloy powder materials:

Solder powder alloy is the core component of solder paste, accounting for at least of the total mass of the solder paste85%~90%. The more common alloy combinations include the following types: tin-lead alloySn-PbTin, lead and silverSn-Pb-AgAlloy, tin-copper alloySn-CuTin-silver-copper alloySn-Ag-CuTin-bismuth alloySn-BiTin-bismuth-silver alloySn-Bi-AgEtc.

The effective components, proportion and particle size of alloy powder materials all have a significant direct impact on the degree of oxide coating compared to solder paste.

When the alloy content is relatively high, it can alleviate the sagging of solder paste, which is conducive to promoting the formation of full and bright solder joints. Moreover, as the content of flux changes along with the continuous increase of alloy content, the residual matter after soldering is also reduced, effectively preventing the existence of solder beads. However, the drawback is that the relevant requirements for printing and soldering processes are becoming increasingly strict.

When the alloy content is relatively low, the printing performance will be very good, the solder paste is not easy to stick to the squeegee, the wettability is good, the solder mask is durable, and the manufacturing and processing will be relatively easy. However, the disadvantage is that it is prone to collapse, and defects such as solder beads or bridging are likely to occur.

The composition and function of flux:

Active agent: The main function of this active ingredient is to removePCBThe important role of oxides on the surface of copper film pads on circuit boards and at the soldering parts of electronic devices is that they can also reduce the liquid surface tension of metals such as tin and lead.

Organic solvents: This active ingredient mainly plays a role in regulating the uniformity of the solder paste during the stirring process and has a significant impact on the service life of the solder paste.

Thixotropic agent: This substance is mainly used to adjust the viscosity and printing performance of solder paste, which can prevent problems such as tail setting and adhesion that often occur during the printing process.

Rosin: Rosin can enhance the adhesion of solder paste and provides systematic protection to prevent post-solderingPCBThe important role of re-oxidation of circuit boards; It will also play a crucial role in the fixation of electronic devices.

JJY Technology Co., Ltd. mainly operatesLEDSolder paste, lead solder paste, lead-silver solder paste, stainless steel plate solder pasteSMTSolder paste, lead-free flux paste, lead-free solder wire, lead-free solder wire, wave soldering wire, automatic solder wire.