PCB Dynamic Coplanarity at Lead-Free SMT Temperatures
Authors: John Davignon, Ken Chiavone, Jiahui Pan, James Henzi, David Mendez, and Ron Kulterman Company: Intel Corporation, Akrometrix, Cisco Systems, Inc. Date Published: 4/30/2012
Abstract: With the advent of larger packages and higher densities/pitch the Industry has been concerned with the coplanarity of both the substrate package and the PCB motherboard. The iNEMI PCB Coplanarity WG generated a snapshot in time of the dynamic coplanarity of several PCB designs from four market sectors. This paper address’s the question as to whether room temperature coplanarity measurements can predict the coplanarity at Lead-Free assembly temperatures. This paper investigated the trends in dynamic coplanarity between market sectors, board thickness and global versus local area of concern measurements. It also shares the learning and issues of undertaking dynamic coplanarity measurements of PCB motherboards.