When the welding ends or pins of components are oxidized or contaminated, welding defects such as poor wetting, virtual welding and voids will occur in reflow welding. Poor coplanar properties of components will also lead to welding defects such as virtua
The heating methods of reflow welding are generally divided into two categories: one is by the red lamp and adapted tube heater; The other type is ceramic plate, aluminum plate and stainless steel plate heater.
pcba aging test standards: 1, low temperature work, 2, high temperature work, 3, high temperature and high humidity work
Wave soldering process: Insert components into corresponding PCBA through holes → spray flux → preheat (temperature 90-110℃) → wave soldering (240-260℃) → cooling → repair welding → remove pins of excess components → check solder joints
PCBA processing and SMT processing differenceThe whole process of PCBA processing actually includes SMT patch processing. SMT patch processing is only part of the PCBA process, which literally means a wider range of processes
The requirements of the mechanical motion part of the SMT machine are as follows: 1. Design, manufacture and assembly technology of micro, precision and high precision mechanical parts; 2, sports machinery express response, low loss, high efficiency, prec
Key points of solder paste printing technology: 1, the Angle of the printing press scraper and steel mesh, 2, scraper pressure, 3, scraper speed, 4, printing gap, 5, release speed
Then SMT patch processing plant will generally do what reliability test of PCBA board: 1, push and pull test: 2, FCT test: 3, fatigue test: 4, ICT test: 5, simulation of automobile transportation vibration test: 6, environmental test test: 7, aging test
Chip production process: 1, silicon purification to make wafers, 2, wafer coating, 3, wafer lithography development, etching, 4, mixed with impurities, 5, wafer testing, 6, chip packaging, 7, testing, packaging
Wiring is generally divided into three levels: one is the layout, which is the most basic requirements of PCB design, the second is to meet the electrical performance, which is the standard to measure whether the circuit board is qualified. Three is beaut
Due to the high temperature pyrolysis of the organic matter in the flux, it is difficult for the air bubbles to escape, resulting in the gas being wrapped in the alloy powder. From the process can be seen, organic matter by the heat produced by the main w
The purpose of testing PCB board is to find out the defects of PCB board and repair them to ensure the production quality of PCB board and improve the qualified rate of products.
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