What are the requirements and precautions for SMT chip processing?
We know that the size of the chip components of many modern electronic products is becoming smaller. In addition to the increasingly small and delicate chip components, the requirements of the processing environment are becoming more and more demanding. Under this product trend, in addition to strengthening product process supervision and innovation and evolution, Jingbang also controls the environment of SMT chip processing workshop more strictly.
First, the environmental requirements of the SMT patch processing workshop
SMT production equipment is a high-precision electromechanical integration equipment. Equipment and process materials have certain requirements for environmental cleanliness, humidity and temperature. In order to ensure the normal operation of the equipment, reduce environmental damage to components and improve quality, the SMT workshop environment has the following requirements:
1, the power supply
Generally, single-phase AC220 (220±10%, 060Hz) and three-phase AC380 (380±10%, 5060Hz) are required. The power of the power supply is more than double the power consumption.
2, gas source
According to the requirements of the equipment, the pressure of the air source can be used. The air source of the factory can be used, or the oil-free compressed air machine can be separately configured. The general pressure is greater than 7kgcm2. Clean and dry purified air is required, so it is necessary to de-oil, de-dust and de-water the compressed air. Use air pipes made of stainless steel or pressure-resistant plastic pipes.
Exhaust fans are required for reflow and wave soldering equipment. For a full hot blast stove, the minimum flow rate for the exhaust duct is 500 cubic feet per minute (14.15 m3 min)
4, temperature and humidity
The ambient temperature of the production workshop is 23±3°C, generally 17～28°C, and the relative humidity is 45%～70%RH. Set the appropriate temperature and humidity meter according to the size of the workshop for timing monitoring and temperature adjustment. Humidity facility.
Workers should wear anti-static clothing, shoes, anti-static bracelets to enter the workshop, anti-static work area should be equipped with anti-static ground, anti-static siting mat, anti-static packaging bags, turnover boxes, PCB racks and so on.
Second, SMT patch processing considerations
1, solder paste refrigeration
The solder paste has just been bought back. If it is not used immediately, it should be placed in the refrigerator for refrigerating. The temperature is preferably between 5 °C and 10 °C, not below 0 °C. There are many explanations on the use of solder paste. There is not much to introduce here.
2, timely replacement of the placement machine is easy to lose goods
In the placement process, due to the aging of the placement machine equipment and the damage of the nozzle and the feeder, the placement machine is liable to stick, and high throwing occurs, which reduces production efficiency and increases production costs. In the case where the placement machine cannot be installed, it is necessary to carefully check whether the nozzle is clogged, damaged, and whether the feeder is intact.
3, measuring the furnace temperature
The quality of PCB board welding has a great relationship with the reasonable setting of reflow soldering process parameters. Generally speaking, the furnace temperature test needs to be carried out twice a day, and the minimum is also measured once a day to continuously improve the temperature curve and set the temperature curve that best fits the welding product. Don't miss this link for the efficiency of production and cost savings.
The above is the industry consultation provided by smt patch processing factory Shenzhen Pengzexiang Technology Co., Ltd., I hope to help you! Please contact us if necessary: http://www.oem-pcb.com firstname.lastname@example.org