Category Archives: Soldering


Feb20
What is IMC (Intermetallic Compound)? How does IMC relate to PCB solder joint strength? Are there IPC standards for IMC thickness?

post on February 20, 2024

In the assembly and soldering process of printed circuit boards (PCBs), we often hear engineers or lab reports mentioning the term “IMC.” But what exactly is IMC? What role does IMC play in the PCB assembly (PCBA) soldering process? Does … Continue reading →

Soldering     WorkingBear    Views (12,175)     comment (0)
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Feb15
NWO (Non-Wet-Open) Defect in BGA Soldering: Causes and Possible Solutions

post on February 15, 2024

Recently, many have inquired about how to deal with Non-Wet-Open (NWO) issues when encountering BGA packaged ICs soldering. The defects associated with NWO are quite similar to those of HIP (Head-in-Pillow) and typically occur at the edges and corners of … Continue reading →

Process, Quality, SMT, Soldering     WorkingBear    Views (4,539)     comment (0)
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Feb06
Purpose of Using Lead-Free Low-Temperature Solder (LTS) SnBi, SnBiAg in Soldering

post on February 6, 2024

The alloy composition of lead-free LTS (Low Temperature Solder) usually includes the metal “bismuth (Bi)” in addition to tin (Sn) to lower its eutectic point. The commonly used lead-free solder SAC305 has a melting point of 217°C, while Sn64Bi35Ag1 has … Continue reading →

Quality, Reliability, SMT, Soldering     WorkingBear    Views (3,435)     comment (0)
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Jan16
RSS or RTS? Which SMT Profile Should You Choose?

post on January 16, 2024

Choosing between RSS (Ramp-Soak-Spike) and RTS (Ramp-To-Spike) for the reflow temperature profile in the SMT (Surface Mount Technology) process has been a constant dilemma for many engineers. Some face pressure from higher-ups to opt for RTS due to cost-saving benefits, … Continue reading →

Process, Quality, SMT, Soldering     WorkingBear    Views (10,389)     comment (0)
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Jan09
What is HIP/HoP? Uncovering the Causes of Head-in-Pillow Defects in SMT Reflow

post on January 9, 2024

The HIP (Head-in-Pillow) defect looks like a person resting their head on a pillow, not buried inside it. Recently, some people refer to it as HoP (Head-on-Pillow). Both terms refer to the non-wetting defect in the solder joints of BGA … Continue reading →

Quality, SMT, Soldering     WorkingBear    Views (4,859)     comment (0)
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