The orthogonal experiment design method was applied to study the relationships between solder joint process parameters and reliability of plastic ball grid array (PBGA) component.By using a

L

18

(2×3

7

) mixed-level orthogonal array

the PBGA test vehicles which have 18 different process parameters' combinations were designed firstly

and then the accelerated thermal cycling test of PBGA test vehicles

which lasted 546 hours with 2140 cycles

was carried out subsequently.Based on the test results

the range analysis and the varianc

e analysis were performed

the failure distribution of PBGA test vehicles was also characterized by using two-parameter Weibull distribution

finally

the stress and strain distribution within the PBGA solder joint under thermal cycles were studied by finite element analysis.The thermal cycling test results show that the cracks of failure solder joints occur at the interface between the solder joints and the bismaleimide-triazine(BT)substrate.The results of study show that specification size of PBGA component has a significant effect on the reliability of solder joints

the chip weight has a certain effect on the reliability

whereas the diameter of pad and the thickness of stencil have little effect on the reliability.The best combinations of process parameters are S2D2G2M1 and S2D2G2M2.The finite element analysis indicates that the maximum stresses of PBGA component under thermal cycles occur at the interface between the solder joint and the BT substrate.The solder joint cracks should be initiated at the interface and then propagate laterally through solder joint.The finite element analysis results are in good accord with the experimental results.Some results of this work have been applied in practice to assemble the PBGA component.