Plastic boss crack of mold-in screw insert potential cause

Recently field complained our product had plastic house broken issue. As checked the defect parts and found the crack came from the screw boss till outside house. There is a mold-in screw INSERT part inside the boss. Below will list the screw boss crack potential causes:

Using Shielding can clip to instead of shielding frame

For almost of the frequency radio apparatus, the Printed Circuit board must design the shielding frame/can to prevent the EMI (Electromagnetic Disturbance Interference) effect. The regular design will apply one shielding frame to mount on PCB by solder and another shielding can to cover on the frame to isolate the RF.

That means there will be two press tools cost before implement this solution. Beside, the shielding frame must be mounted on the PCB by SMT process. It requires lower flatness specification to keep the solder joint well. Most of the shielding frame asks its flatness meet 0.12mm maximum. Some of the shielding frame even asks the flatness must lower than 0.10mm maximum. Because of current stencil thickness is around 0.10~0.127mm only. It brings more difficult to form the shielding frame and raise its cost.

The actuator design for right angle connector

Recently my company met lots of component broken troubles for the electrical connector call “right angle connector” or “flip lock connector” in manufacturing production line. We found almost the defect connector broke at the ACTUATOR portion while operators first time tried to lift it after SMT high temperature reflow process. I’m sure the connector works fine before reflow.

I did a study on the connector and found it was caused by the connector itself while through SMT high temperature reflow process as below two reasons:

TQRDCE Performance Expectations and Review

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

TQRDCE Introduction:

The strategy of company for establishing and maintaining long-term working relationships is through creating and monitoring mutual performance expect ions and measurements. Performance metrics, constructive feedback, as well as prompt corrective action by the supplier and by customer are fundamental to achieving continuous process improvement.

Hot-Bar Flex cable Design Notices

The Hot-Bar reflow is a selective soldering process where connect two pre-fluxed, solder coated parts by heating element, call a thermode, with proper temperature to melt the solder.

Applying a pressure and contacting on the soldering target is necessary to melt the solder and insure that components stay in place during cooling.

Shipping carton drop/impact test

The electronic industry grows quickly. Each vendor takes responsible to his own component only to make it good and low cost. Take a flashlight manufacturer as example. There are bulb, wires, switch, spring, and plastic or metal housing make up the flashlight. The manufacturer buys all the sub-components from each supplier and assembles them together to fabricate the flashlight then sell to end-user.

All the sub-components are delivery by air, ocean, or truck to destination. It is important to prevent the delivery parts without damage during transferring. Most of the packaging uses corrugated paper carton and cardboard to hold inside components and prevent it from damage by falling or throwing down by porter or carrier.

Flex cable(FPC) Trace Pattern Layout Design Notices

Many FPCB designer are not familiar with the manufacturer and bring lot of quality issue after mass production. Here I summary some of the design notices for the flex cable (FPCB)  manufacturing  ability to prevent future quality fail.