Title :
Cracks: the hidden defect
Author_Institution :
AVX Corp., Colorado Springs, CO, USA
Abstract :
Causes of cracks in surface-mounted multilayer ceramic (MLC) capacitors are discussed. Cracks due to thermal shock, pick-and-place machine damage, vacuum pickup bits, jaw damage, and warping are examined. Defects introduced by board depanelization and warpage after soldering are also considered. Three types of visible internal defects in MLC capacitors that impair reliability-interelectrode voids, firing cracks, and knit-line cracks- are described. It is suggested that lack of care during the surface-mount assembly process can result in damage that vitiates its benefits
Keywords :
capacitors; ceramics; printed circuits; reliability; surface mount technology; thermal stress cracking; MLC capacitors; board depanelization; firing cracks; interelectrode voids; internal defects; jaw damage; knit-line cracks; pick-and-place machine damage; reliability; soldering; surface mounted multilayer ceramic capacitors; surface-mount assembly process; thermal shock; vacuum pickup bits; warp cracks; Assembly; Building materials; Ceramics; Electric shock; Electrodes; Leakage current; Soldering; Surface cracks; Temperature dependence; Thermal stresses;
Conference_Titel :
Electronics Components Conference, 1988., Proceedings of the 38th
Conference_Location :
Los Angeles, CA
DOI :
10.1109/ECC.1988.12620
