Innovative RF Shield Rework Method for Wireless Module in Ultrathin Notebook

A breakthrough cost effective rework method for RF(Radio Frequency) shield with lower cycle time has been developed which is using hot plate rework equipment together with a customized hot plate fixture to remove and place the RF shield onto the PCB. The basic principle that has been applied on the new rework method for RF shield is conduction heat transfer whereby the heat transfer rate is higher if compared to the convection heat transfer that being used in conventional reflow process with rework machine. The rework cycle time will be reduced with higher heat transfer rate during rework to melt the RF shield solder joint. The cycle time of the rework process with the hot plate fixture to melt the RF shield solder joint has been successfully reduced significantly by ~82%. In term of rework cost reduction, based on the cost saving calculation for one of the wireless module products after using this innovative RF shield rework method, the rework cost has been reduced by ~80%. This paper will review the design of the customized hot plate fixture, the conduction heat transfer concept with the hot plate rework machine and detail of the removal and placement of the RF shield.