A Low-cost Electronic Product Fabrication and Assembly with Improvement of Thermal Performance and ESD Protection

摘要

A low-cost electronic product fabrication and assembly with improvement of thermal performance and electrostatic discharge (ESD) protection is addressed. Below attachment lists four application types of such solution. For Application 14, one should reserve solder-mask opening on component side of printed circuit board (PCB) for the soldering with exposed pad (E-pad) with Low Profile Quad Flat Pack (LQFP) package or thermal ground balls with Ball Grid Array (BGA) package. Besides, for Application 13, one should also reserve solder-mask opening on solder side of PCB. Additionally, a lot of via holes to connect the two thermal-ground planes are recommended. By some special mechanism design or screws to connect all the ground planes and metal chassis, the heat of integrated circuit (IC) will easily spread to air by outer metal chassis. Furthermore, the ESD protection is also enhanced due to better and shorter conducting path to chassis ground. Some special material, such as conductive glue or tape or insulating thermal pad for heat spreading only, could be added to enhance the connection and conductivity between PCB and metal chassis. Besides, the special mechanism design for heat spreading could not be designed just under the chip due to some limitation of PCB design, such as the de-coupling capacitors under the BGA chip. Some shift is acceptable. However, if possible, it is better to design the path of heat to be shortest. With such solution, the surface temperature of IC could be lowed down even 18掳C without heat-sink or fan.