Author Archives: WorkingBear


Jun13
How to Determine Whether Underfill is Needed for BGA?

A question from a netizen, “In the past, many mobile phone PCB assemblies would use Underfill depositing under the BGA package to enhance the mechanical strength of the solder joints. However, it has been found that most mobile phone assemblies … Continue reading

Jun06
Questions from Newcomer: Why is Solder Paste Needed for SMT Reflow since BGA Already has Solder Balls? Is Solder Paste Needed for BGA Repair?

Questions from a newcomer about electronic manufacturing assembly process: Since there are already solder balls locate on the BGA substrate, why is it necessary to apply solder paste on the PCB pads during SMT reflow? Is it necessary to apply … Continue reading

Jun01
What is Wave Soldering? Laminar Wave and Turbulent Wave Purpose

Before the development of Surface Mount Technology (SMT), almost all printed circuit board assemblies (PCBAs) had to go through the process of wave soldering to achieve the purpose of soldering electronic components to the board. The process of “wave soldering” … Continue reading

May30
The Hidden Dangers of Using Overdue PCBs: Can Baking Salvage Them?

All materials actually have its shelf-life, some shorter and some longer than others. So what happens when expired materials are used? Think about what will happens when you eat expired food. What about using expired Printed Circuit Boards (PCBs)?

May22
What is the Purpose of Surface Finishes for PCB? A Summary of the Pros and Cons of Common PCB Finishes

This is just a summary article about PCB surface finishes. Workingbear has only worked on the electronic system assembly factory and has not been involved in the production process of bare PCBs. Therefore, the following insights are based on personal … Continue reading