Finite Element Analysis of the S-spring Interposer for Electronic Connector Materials under Loading

• Main Authors: wang-cheih Yu, 余王傑
• Other Authors: Fong-Ming Lee
• Format: Others
• Language: zh-TW
• Published: 2000
• Online Access: http://ndltd.ncl.edu.tw/handle/54638570663389963064

碩士 === 中國文化大學 === 材料科學與製造研究所 === 88 === IBM publish of the Controlled Collapse Chip Connection (C4) technology and Ball Grid Array (BGA) at two different times of many years ago , hence has decrease of the density beyond the tradition of pin grid array (PGA) and high density gold wire interconnect . However the Sn/Pb BGA solder joint connectors used between chips and substrates what subject to vibrations and thermal stresses are about to fatigue failures and interface cracking which eventually led to increase in contact resistance. In this paper , in the course of search for replacing the Sn-Pd BGA , A new approach called " S spring interposer connector " is introduced . We employed the MSC/NASTRAN finite element analysis software to analysis the unit S-spring in this Interposer Connector . The S-spring having a perfect spring geometry made of Beryllium-Copper which has excellent elastic properties . The structure of this paper is based on a math model in a static condition , combined with the NASTRAN FEA computer simulation , and compared with the experimental data on mechanical properties of the materials . As a result we obtained three sets of data rather compatible and useful . Using the FEA , we varied the size, loading, parameter, of materials in order to cover a wide range of stress conditions within the limit of plastic deformation or lower than the yield strength . We also experimentally the cracks on the cross sectional captured the surface along the maximum stress area of spring materials .