Predicting plated-through-hole reliability in high temperaturemanufacturing processes

摘要

Plated-through-holes (PTH) represent a sensitive interconnectstructure in a printed wiring board (PWB) that can be adversely affectedby both manufacturing and field-use load cycles. A PTH/PWB model hasbeen developed using the finite-element method (FEM) and theManson-Coffin equation. The author discusses the model development andits application in an exhaustive test program where coupons of twolaminate materials (FR4 and PI), four drilled hole sizes (0.0135 in,0.0160 in, 0.023 in, and 0.043 in), and four nominal plating thicknesses(0.0005 in, 0.0010 in, 0.0015 in, and 0.0020 in) were tested. Based onmeasured ductility from the IPC Copper Foil Round-Robin Study, goodagreement is obtained between the measured and predicted PTHreliability. A sensitivity analysis in which the model is used topredict the reliability of a PTH/PWB structure is presented. Thevariables examined are laminate T_g and TCE, drilled hole andpad diameter, minimum plating thickness, and plating nonuniformity