Improvement of Printed Circuit Board Assembly Process in 2.4GHz RF Circuit Products

Abstract

The semiconductor process technology and the circuit design concept are continuously improved at the recent era. The product cost is gradually decreased, too. The commercial electronic products generally cover ICs, external components and printed circuit board (PCB). After the circuit layout blueprints are completed, engineers will transfer them into PCB as a prototype. The next step is to integrate some contributed electronic components to form a functional product. This second step is called as PCB assembly (PCBA). However, the bigger copper area on PCB will provide a good thermal dissipation. This effect will degrade the solderability and increase the contact resistance while the electronic components are integrated on PCB. The product performance, therefore, is deteriorated. Contriving some special empty boundary shapes neighboring the connected pins of integrated electronic components to soften the thermal dissipation ability of copper layer on printed circuit substrate is a good method. We design some useful patterns to conquer this issue and increase the PCB assembly yield from 70% to 95%. The other efforts are to study the flow rate of isolated ink in PCBA production line and suitably control the solder temperature. Because some electronic components are composed by plastic materials, higher temperature will damage the external shapes of them and the PCB has the bending possibility. These two beneficial efforts also contribute the assembly yield well in 2.4GHz radio-frequency (RF) products.