Author Archives: WorkingBear


Jan22
How Adding a Second Source (2nd Source) Can Create a Win-Win for Cost Reduction

As an engineer, Workingbear has to be honest—I really don’t like doing second-source qualification work. It’s time-consuming, stressful, and often thankless. If you do it well, management thinks it’s just part of your job. If it takes too long, they … Continue reading

Jan14
Explaining the Relationship Between BOM, AML, AVL, and MPN

BOMs, AML/AVL, and MPNs are essentially the “recipe” behind electronics manufacturing. All of these terms are closely related to a product’s material list. Understanding what they mean is not difficult—the real challenge is knowing how to apply them effectively to … Continue reading

Jan07
For Beginners: What Is a BOM? How BOM Works with ECO, ECN, and ECR in Electronics Manufacturing

For many people who are new to the electronics manufacturing and assembly industry, BOM and ECO are two very important terms—but also two of the most confusing ones. In this article, I’ll try to explain these concepts in a simple … Continue reading

Dec31
Understanding TAL (Time Above Liquidus) and Why It Matters in PCB Assembly

TAL (Time Above Liquidus) refers to the amount of time during the SMT reflow process when the solder material (such as solder paste) is above its liquidus temperature. You can think of it like ice melting into water and then … Continue reading

Dec24
Why Does Second-Source Qualification Always Fall into a Vicious Cycle?

“Second-source” qualification usually means that a component has at least two qualified suppliers. The reasons for introducing a second source are straightforward: to deal with material shortages, handle EOL (End of Life) parts, reduce material costs, increase price negotiation leverage, … Continue reading