Author Archives: WorkingBear

What purpose of alloy metal of Cu, Ag, Zn, Sb, Bi added to solder paste?

Tin (Sn) based solder is still the best material for PCB (Printed Circuit Board) assembly in the modern industry today. The only difference is the lead (Pb) free from the solder base due to environmental concerns. The melting point of … Continue reading

Why BGA soldering ball always crack(3)? IMC layer growth is a certain result to form the soldering joints

The Intermetallic Compound (IMC) layer grows in the interface between Cu-based, Ni-based and Sn-solder is the certain result of the chemical reaction that forming the soldering joint. But the IMC layer is also the most weakness location of the solder … Continue reading

Why BGA soldering ball always crack(2)? The composition of PCBA bonding-force

This article will talk about the composition of the PCBA bonding-force. The PCBA bonding-force actually contains many items and factors. But working-bear think we can refer to the conclusion of red-dye test to discuss it. The BGA red dye and … Continue reading

Why BGA soldering ball always crack(1)? Stress > bonding-force

What is the actual root cause of  BGA ball cracked? Stress is greater than its bonding-forces. The root cause of BGA solder ball cracked is stress greater than bonding-forces. Stress is greater than bonding-force is the certain result of BGA … Continue reading

What is IMC (Intermetallic Compound) in the electronic manufacturing industry?

What is the IMC, the Intermetallic Compound? We always heard the manufacturing engineer or some of Mechanical Engineer talking about this keyword when discussed to the soldering quality or component drop issue. So, what is the role of IMC layer … Continue reading