Study Of The Mechanical Behavior Of Area Array Packages Interconnection Structures Under Shear Load

With the development of electronic products on the miniaturization, multi-function direction, face array package has become the mainstream of currentpackaging forms with high I/O number, good thermal conductivity, smallpackaging volume and low cost. The damage to failure which is caused by shearload may be produced by thermal cycling, drop impact and other factors betweenthe chip and the circuit substrate board of electronic products in practice.Therefore, the study on shear properties of the interconnection structure is veryimportant.In this thesis, the shear performance of single BGA micro-joint, the wholeinterconnect structures of CCGA and CuCGA were studied by the PTR-1100joint strength tester, and the effects caused by the interconnect structures withdifferent solder joints shape parameters and shear rate to the shear behaviors. Theresults showed that:1) The shear curves of BGA micro-joint and interconnect structures keptparabolas. CCGA and CuCGA interconnect structures shear curves showed infour different phases. It was mainly the elastic deformation in the first stage, andthe flexural deformation in the second stage.2) The shear force until fracture of SAC305and Sn30Pb70BGA micro-jointdecreased with increasing of shear height, and increased with increasing of shearrate. And its displacement until fracture increased with increasing of shear height;but there were some differences about displacement until fracture betweenSAC305and Sn30Pb70materials with different shear rates. With the increase ofshear rate, the shear force until fracture of SAC305and Sn30Pb70BGA interconnect structures increased, the displacement until fracture decreased.3) The shear force until fracture of CCGA decreased firstly and thenincreased, and leveled off at last with length-diameter ratios from3to10. Thevalue of shear force to fracture of CuCGA has a tendency to climb up withlength-diameter ratios from6to12, but the trend of climbing up will becomeslowly. With the increased of shear rate, the shear force until fracture of CCGAand CuCGA increased, and so dose the displacement until fracture of CuCGA,the influence caused by shear rate to the displacement until fracture of CCGAwas different by the different length-diameter ratios.4) Under the same shear condition, the shear force until fracture of SAC305BGA micro-joint was about1~4N more than Sn30Pb70’s, and about3N morethan interconnection’s, the displacement until fracture of SAC305was lager thanSn30Pb70. And under the same length-diameter ratios, despite the high-rateshearing or the low-rate shearing, the shear force until fracture of CuCGA was30~60N more than the CCGA.