Category Archives: Process


Jan09
Why Do Electronic Component Leads Turn Yellow, Purple, or Blue After Reflow? Causes and Solutions

Workingbear recently received questions from readers about electronic component soldering leads turning yellow or showing discoloration (purple, blue, etc.) after going through the reflow oven. Why do the leads of components discolor after reflow? Does this discoloration affect product functionality? … Continue reading

Nov07
The Benefits of Using “Mirrored Panelization” for PCBs

In the electronics assembly manufacturing industry, what we commonly refer to as a “Mirrored Panel Board” or “Flipped Panel Board” actually comes in two types. The first type is a different-side mirrored panel board, where one board’s top side and … Continue reading

Oct31
The Limitations of Using “Mirrored Panels” or “Flipped Panels” in SMT

We all know that when producing PCBs and PCBAs, multiple individual PCBs are usually combined into one larger panel, a process called panelization, to improve production efficiency. Typically, these individual boards are arranged in a neat and consistent manner with … Continue reading

Oct03
What Causes Wave-Like Wrinkles or Cracks in Solder Joints After Reflow?

These soldering wrinkles appeared quite a while ago, but Workingbear recently came across a similar situation on an online forum. Thinking others might encounter the same issue, I decided to document it for both personal reference and to share with … Continue reading

Aug22
What is ENIG Surface Finished for Circuit Boards? What Are Its Advantages and Disadvantages?

ENIG (Electroless Nickel Immersion Gold), also known as immersion gold (Au), chemical Ni/Au, or soft gold, is a type of surface finished for printed circuit boards (PCBs). It is widely used in the assembly of mobile phone circuit boards and … Continue reading