SMD soldering process

Hefei, Jinan circuit board welding factory has first-class technical staff, complete the bumping process, especially for the TI series PAD concave packaged chip bumping a unique technology, perfect solution to the small spacing POP chip bumping problem, currently in in the leading position at home and abroad. Bumping process Collection: A, the first step is to distinguish IC lead or lead-free process, otherwise the IC pollution reach the RoHS requirements, the consequences are extremely serious; B, the second step, before bumping to do baking, IC packaging material is generally plastic or ceramic, easy to absorb moisture at room temperature, if not baked before bumping, can easily lead to damage to the IC chip stratified, industry commonly known as "popcorn" phenomenon; C, bumping After welding solder balls according to the chemical composition, set the appropriate temperature, or likely to cause bumping strong, not straight, the ball is not round and other negative phenomena; Ⅰ) have solder balls (Sn63Pb37, tin 63% lead 37% ) Melting point 183 ℃. Ⅱ) free solder ball (Sn96.5AG3Cu0.5, tin of 96.5% silver and 3% Cu 0.5%) melting point 217 ℃. D, plant general strike of the IC to do short of baking, to remove the IC surface adsorbed moisture, baking is completed in a timely manner into the Cabinets, vacuum-packed or on tape and reel, so as not to lead to a resurgence when the IC mount Layered damage IC;