2020 Reports

Author:  Peter McClure 
Copper coins embedded into printed circuit boards offer a higher thermal conductivity heat dissipation solution.  Copper coins are monolithic slugs of copper embedded into printed circuit boards such that components can be soldered directly to them thereby enhancing heat transfer through the board thickness.  While the thermal advantages of copper coins are clear, the reliability of embedded copper coin systems has not been thoroughly examined.  It is possible that the thermal expansion mismatch of the solid copper and surrounding PCB could drive cyclic stress induced failures.  This study examines T shaped copper coin circuit boards with attached quad-flat no-lead (QFN) packages subjected to thermal cycling.  These boards were examined for failures in the board circuity, coin attachment epoxy, electroplated copper, or solder joints/pads.
Key words: Copper Coin, Reliability, QFN, Thermal Management