Shenzhen Jiasu Innovation Technology Co., Ltd. is a professional small and medium SMT patch,PCBA proofing and patch processing enterprises, the company specializes in PCB model welding, PCBA modification, model processing, BGA packaging processing, ball planting and repair, small batch SMT patch processing, DIP plug-in post-welding, assembly of various high-tech electronic products And other series of processing services;
1. Glass transition temperature (Tg)
Tg is a characteristic property of polymers, it is the critical temperature that determines the properties of materials, and it is also a key parameter for selecting substrate materials. The temperature of the PCB exceeds Tg, and the thermal expansion coefficient becomes larger.
PCBA proofing patch is generally divided into low Tg, medium Tg and high Tg boards according to the Tg temperature. In the industry, boards with a Tg around 135°C are usually classified as low-Tg boards; boards with a Tg around 150°C are classified as medium-Tg boards; and boards with a Tg around 170°C are classified as high-Tg boards.
If there are many pressing times during PCB processing (more than 1 time), or there are many PCB layers (more than 14 layers), or the soldering temperature is high (GG gt; 230℃), or the working temperature is high (more than 100℃), or soldering heat For high stress (such as wave soldering), high Tg plates should be selected.
2. Coefficient of Thermal Expansion (CTE)
The coefficient of thermal expansion is related to the reliability of welding and use. The principle of selection is to be as consistent as possible with the coefficient of expansion of Cu to reduce thermal deformation (dynamic deformation) during welding).
3. Heat resistance
Heat resistance mainly considers the ability to withstand the soldering temperature and the number of soldering times. Usually, the actual welding test is carried out with slightly stricter process conditions than normal welding. It can also be selected according to performance indicators such as Td (temperature at 5% weight loss during heating), T260, T288 (thermal cracking time).
The main processing product packages are: LGA, CSP, BGA, KFP, QFN, 0805, 0603, 0402, PCBA proofing patch,0201, the chip can be attached 0.3mm densely, and the processed products include: wireless communication series (motherboards, public phone motherboards, walkie-talkies, etc.), household appliances series (air conditioners, mobile phones, smart speakers, car navigation motherboards and Bluetooth peripheral products, etc.) , Computer peripheral series (motherboards, graphics cards, U disks, camera boards, twisted pair transmitters, etc.), digital cameras, optoelectronic products, mobile phones, with good quality and short cycle, fast speed, low cost, we solemnly promise: strictly observe your Trade secrets, strictly guarantee the welding quality, and repair defective products free of charge.