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:
- The connector become brittle after SMT high temperature reflow process. Especially for the RoHS profile needs higher temperature to melt the solder paste. I also found some of the resin still applies the PA66 as connector material and this resin is really easily become brittle once it soaks in the atmosphere with moisture too long and without bake then go before reflow. In order to get more reliability component and reduce the plastic brittle risk that recommend applying the LCP resin to instead of the PA66 for the connector material to reduce the brittle risk.
- The HOUSING of connector is deformed by high temperature and snapped the ACTUATOR. The operator needs more force to lift the ACTUATOR for the FPC insertion but the bump on the ACTUATOR sides are really locked it on HOUSING firmly. I found more the pin number of connector will get higher breaking defect rate.
In order to fix this kind of connector broken defect we started work with existed connector supplier and sourced various new suppliers. Finally we found a new style of connector can fix this issue. This new connector really surprised me. Because of its ACTUATOR can be lifted without much force before FPC insert even through reflow profile. The magic thing is the ACTUATOR holding force will be increased suddenly after the FPC insert. That means the ACTUATOR does not only fix the actuator broken defect but also prevent the FPC slide out problem.
How this connector works to hold the FPC? Actually it is really simple concept to use the interference between the bottom of swivel of ACTUATOR and FPC. Basically connector designer will make a radius to prevent connector interferes with FPC. Apparently now this interference turns the trouble to benefit.
Also this new type of right angle connector reduces its bump size on the side of ACTUATOR to minimum the locking force. Some of the connector also changes bump as triangle shape same as interference idea too. No recommend to remove the ACTUATOR locking mechanism. Because of it will become free motion and may be damaged by board handing due to lifting careless.
Because of new style of connector apply the bottom of swivel of ACTUATOR to hold the FPC, so this area will need robust structure. Making multi-cell holes on the ACTUATOR will make it stronger and save some plastic resin material. A more accurately tool maker and injection machine will be necessary for this new style connector. Also needs to pay more attention on tool maintenance to prevent flashes happen.
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