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

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 1~4, 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 1~3, 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 18degC without heat-sink or fan. With such solution, ESD protection could be improved about 40%. We provide a low cost and efficient solution to solve the issue of heat spreading and ESD protection. The traditional solution for heat spreading is expensive and lower efficiency. By the way, with this solution, we would not have to implement "heat spreader" on our BGA package for cost saving (about USD$ 0.2/ea). Some solutions for ESD issue are also time consuming and require - extra cost during the development of hardware system platform. By our solution, beside the advantage of heat spreading, we could also improve ESD protection a lot, even exceeds 50%.