Choose the right metal material, resin can improve the reliability of welding. Suitable for reflow soldering, mounted on the PCB board shrapnel terminals are generally surface mount or through-hole installation. The surface-mounted solder pins must be properly positioned, sized, fully coplanar with the PCB or micro-floats to accommodate all tin plates on the PCB to ensure sufficient strength, process quality and circuit reliability. The needle must be accurately positioned, sized, equilibrated, and have good solderability, which facilitates insertion and welding. In the whole assembly process must withstand the heat generated by the high temperature impact, in the welding of the main use of infrared preheating and convection preheating heat conduction to the welding pin and tin plate interface to melt solder paste. The next need not force the cleaning, but people generally expect to clean. The temperature of the preheating zone is typically set at a peak of 230 ° C and the temperature is higher after a few minutes. Like the same wave soldering, the sudden high temperature often makes the terminals melt, twist, blister and deform.
There are significant differences in welding conditions, depending on the type of shrapnel terminals and the steps of the welding process. Suitable for wave soldering, the terminal blocks mounted on the PCB are typical perforated mounting. Perforated solder pins must be accurately positioned, fit in size, evenly placed, and have good solderability, which is conducive to the insertion and welding. During the entire assembly process, it is necessary to withstand the high temperature of the preheating zone and the temperature of the terminal body through the wave soldering. Flux must not affect the terminals, must be easy to remove, can not have any residue. The entire assembly process must be clean with water. Preheat temperatures often reach 100 ° C or higher, and crest temperatures up to 280 ° C are not uncommon. Sudden high temperatures often cause the terminals to melt, twist, blister and deform. Assembly time is generally divided into a few minutes exposed to flux time, a few minutes of warm-up period, a few seconds of the peak period, and a few minutes of cleaning and drying period.
Assembly time is generally divided into a few minutes of warm-up period, a few seconds of peak, and a few minutes of cleaning and drying period. Of course, the choice of appropriate metal materials, resin can improve the reliability of welding. Through-type terminal blocks, electronic modules and ceramic terminals are often manually assembled, reliability depends on the human factors during operation, such as: screwdriver strength, tight torque when the size and installed on the board screw tightening The Torque is too large or uncontrollable screw tightening strength will seriously affect the connection performance, and sometimes the performance is obvious, sometimes in the field wiring is not easy to be aware of, when a period of time, use a few weeks or months later just show.
There are significant differences in welding conditions, depending on the type of shrapnel terminals and the steps of the welding process. Suitable for wave soldering, the terminal blocks mounted on the PCB are typical perforated mounting. Perforated solder pins must be accurately positioned, fit in size, evenly placed, and have good solderability, which is conducive to the insertion and welding. During the entire assembly process, it is necessary to withstand the high temperature of the preheating zone and the temperature of the terminal body through the wave soldering. Flux must not affect the terminals, must be easy to remove, can not have any residue. The entire assembly process must be clean with water. Preheat temperatures often reach 100 ° C or higher, and crest temperatures up to 280 ° C are not uncommon. Sudden high temperatures often cause the terminals to melt, twist, blister and deform. Assembly time is generally divided into a few minutes exposed to flux time, a few minutes of warm-up period, a few seconds of the peak period, and a few minutes of cleaning and drying period.