Reliabiulity of via-in-pad structures in mechanical cycling fatigue

摘要

Increased packaging density, along with large-scale implementation of ball grid arrays (BGAs), chip scale packages and DCAs in portable products has resulted in the need for innovative techniques to increase the I/O density in printed circuit boards. With the development of high density interconnect (HDI), via-in-pad has emerged as one of the key enabling technologies for increasing the I/O density. Via-in-pad permits the use of sub-surface layers for fan out and consequently, smaller packages with higher I/O can be utilized in the design.