Development of the lead free soldering process for portable applications, EMPC

In the frame of European Union founded IMECAT-project the lead free soldering process for portable electronic devices has been developed. For the evaluation suppose a special PCB testboard has been designed. The lead free components which are selected to this testboard are commonly used in portable applications. The smallest components are 0201-type lead free resistors which are assemblied in groups of 72 components. The effective coverage level of the PCB area was 30 %. Also the behaviour of package types like LGA, BGA, QFP and CSP was studied. The metal platings on the testboards were tin, organic coating (OSP) and traditional nickel/gold. All the boards were inspected with sub-micron level X-ray equipment. The soldering profile used, was linear type and was also carefully adjusted for suitable leadfree components. The differences in the measured temperatures between components was optimized. As a result a robust process for leadfree SMT-assembly of portable electronics can be presented