Development of the Four Cellular-Band RF Loadboard for Mass Production on Automatic Test Equipment

• Main Authors: Wen-Fu Tsai, 蔡文福
• Other Authors: T.S. Jason Horng
• Format: Others
• Language: en_US
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/05000132782690714811

碩士 === 國立中山大學 === 電機工程學系研究所 === 96 === This research aims at the development of a RF mass production load board for 4 bands cellular phone (850 MHz GSM-USA, 900 MHz GSM, 1.8 GHz DCS and 1.9 GHz PCS). To construct a strong theoretical foundation, the characteristics of key components such as relays, balun, cables, vias, micro strip line on the load board and the RF rules for PCB layout are extensively studied. An experimental load board is also specially designed to study the characteristics of RF printed circuit board. In this experimental load board, different materials (FR4 and Rogers) and transmission lines (microstrip lines and differential lines) are specially made and measured. After studying this experimental load board, we co-work with the RF load board supplier KeyStone to do the simulation as the preparation of production load board. In this simulation, the actual layout (Gerber file) of critical path together with the socket is checked for the resonance frequency. The production load board is manufactured in FR4 and debugged in the off-line debugging station before a correlation process in the ATE (automatic test equipment). Fine tune of 4 bands matching circuit is done by changing the value and/or the position of component on the matching circuit with VNA. After the fine tune, 70 good devices were tested twice on the same u-Flex tester with the developed load board and the one sent from test center in Europe (reference loadboard). The test results are processed by statistics tool “Data Power” to calculate the mean value, variance, Cpk (biased process capability), R&R (Repeatability and Reproducibility), etc. The statistics results show the performance of the developed RF load board and the one from the test center in Europe is compatible and can be released for mass production. From this research, design flow of RF loadboard, highly relies on simulation to guarantee the performance of RF loadboard instead of basing on experience and/or trial and error, has been built up