Jul01
Why do thinner PCBs will need carrier for reflow process?

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As the career of Manufacturing Process Engineering(MPE), WorkingBear has noticed a constant battle between Designers, Marketers, and Manufacturers. Marketers always want  thin, modern design that look thin. Designers think fabrication is simple, while Manufacturers want  strong, robust, sturdy assemblies that won’t be scratch easily on the surface. However, both of parties also want low costs.

This leads to two common questions from R&D and marketing professionals:

  1. Why do thinner PCBs require a special carrier or template for the reflow process?
  2. Aren’t all PCBs reflowed as a panel, requiring a support fixture for de-panelization?

Since WorkingBear is MPE, so I will answer these two questions as manufacturing point.

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Jun24
Case study for the mold-in insert screw boss broken

Case study for the mold-in insert screw boss broken

In a previous discussion, WorkingBear identified potential root causes for screw boss cracking after mold-in screw nut insertion. Following a complaint from the field, we asked EMS and the plastic injection supplier to double-check their inventory and found that approximately 1% of the plastic case had cracked on the screw bosses due to inner stress during the mold-in screw nut insert process, without any additional force or screwdriver. However, the defect rate increased to 30% after the screws were fastened into the plastic case.

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Jun17
Selectively/partial increase solder paste volume solutions

Why is it necessary to partially increase the solder paste volume in SMT soldering?

To meet the demands of smaller and thinner electronic component designs, stencils are made as thin as possible to precisely control the tiny solder paste printed on the PCB.

However, this creates a challenge when smaller and larger electronic surface-mounted devices (SMDs) need to be mounted on the same board. The stencil’s thinness limits the amount of solder paste that can be deposited, and extending the stencil aperture over the pad size is still not  yet enough to fill the necessary volume of solder. To provide sufficient solder paste volume for larger components, as well as for HTD components, EMS has implemented the PIH (Paste in Hole) process.

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Jun10
PCB rework: Selective solder mask removal by laser

PCB rework: Selective solder mask removal by laserAs an engineer in the electronics manufacturing industry, have you ever encountered the need to rework a printed circuit board (PCB) to remove the solder mask? If so, how did you approach this problem?

Traditionally, the solder mask is manually removed using a knife or hand grinding tool. However, this method often results in damage to the traces on the PCB, leading to a high scrap rate for both the PCB and PCB assembly.

WorkingBear would like to introduce a new method of removing the solder mask using a laser machine, which is highly efficient and reliable. By selecting the appropriate laser power, the solder mask can be removed without damaging the copper underneath. read more…》

Jun03
TQRDCE Performance Expectations and Review

This is an example that implement TRQDCE form for vendor survey.


TQRDCE Introduction:

TQRDCE ChecklistThe company’s approach to establishing and maintaining long-term working relationships involves creating and monitoring mutual performance expectations and measurements. The use of performance metrics, constructive feedback, and prompt corrective action by both the supplier and customer is essential for achieving continuous process improvement.

To enable customers to measure our suppliers, we have developed the TQRDCE (Technology, Quality, Responsiveness, Delivery, Cost, and Environmental) review. It is crucial for suppliers to maintain a competitive advantage by providing materials of the highest quality and lowest total cost, with the best delivery, responsiveness, and technology available. The TQRDCE review is a tool that measures and communicates a supplier’s performance, and assists the company in determining their position in future business relationships.

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