Analysis of Thermal Stress and Strain in BGA Solder Joint Based on Microchannel Ceramic Substrate

A finite-element analysis model of ball grid array (BGA) solder joints for microfluidic ceramic substrates was established, and fluid-structure-coupled finite-element simulation analysis was performed. The influences of three microchannel structures of straight-line type, rectilinear type, and polyline type, and different microchannel structure parameters on the stress and strain of BGA solder joints were analyzed. Sixteen orthogonal microchannel structure parameter levels were designed using an orthogonal table. Combining and establishing corresponding 16 groups of finite-element models for simulation analysis, the maximum stress data of the 16 BGA solder joints obtained were analyzed by range analysis and variance analysis. The results show that the microchannel spacing has the greatest impact on BGA solder joint stress. Followed by the length of the microchannel cross section, and again the width of the microchannel cross section, analysis of variance showed that in the case of a confidence of 95%, the microfluid spacing of BGA solder joints has a significant effect on the stress of BGA solder joints and straight-arranged microflow. The length and width of the cross section had no significant effect on the weld stress. The microchannel experimental samples corresponding to the simulation analysis were produced, and the accuracy of the simulation results was verified by experiments within a certain error range and the thermal fatigue life analysis of BGA solder joints on ceramic substrates.