Feb01
Solder Preforms – Another Choice for Solder Volume Increasing Solution

Today, most of electronic components are developed into smaller size. The small chips are downsized from 1206 to 0805, 0603, 0402, 0201, even to 01005. The size of chip is smaller; the required solder volume is less.

Moreover, the required stencil thickness becomes thinner from 0.18mm to 0.10mm or 0.08mm. Some components, however, cannot be downsized unlimitedly, such as external connectors. For example, a line socket of telephone, a network line socket, a smart card reader, and other devices require a certain amount volume of solder to ensure the soldering strength and quality. In addition, some traditional insertion parts (THD, Through Hole Devices) with paste-in-hole process require extra solder volume as well.

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Jan04
What is Step-up & Step-down Stencil? Selective Solder Paste Volume Increasing Solution

Step_down_stencilThe trend in the electronics industry is toward smaller and smaller SMD components, with sizes such as 0402, 0201, and even 01005 becoming common (Note 1). Additionally, the pitch between pins on ICs has decreased to a fine pitch of 0.5mm, and even 0.3mm, posing a challenge for the SMT process.

SMT engineers face the challenge of soldering these thin electronic components onto PCBs without encountering non-wetting or soldering short issues. This task is more difficult when dealing with a mix of larger and smaller parts on a circuit board.

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Oct01
Copper Defined vs. Solder Mask Defined pad design for BGA soldering strength

Cooper Defined vs. Solder Mask Defined pad design for BGA soldering strength

Since the electronic product design moves from desktop to portable devices, the manufacturer also make electronic component as small as possible to meet this popular trend. Besides, the PCB thickness also become thinner and the associated soldering pads on the PCB are tiny size. This  make the SMT manufacturing process more difficult and challenge.

You may know that portable device always has BGA malfunction risk during impact drop test. Most of company dispense the underfill glue to fix this kind of BGA crack issue. My company did the same thing too.  WorkingBear think there shall be another way to enhance the soldering pad strength to eliminate the underfill glue since underfill process spend money and waste labor hours.

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

BGA_underfill_crack01BGA_underfill_crack02

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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