Skylake CPUs can be notoriously susceptible to the issue of cracking when benching with LN2, a phenomenon where the heat conductivity between the pot and the HIS is reduced by trapped air between the IHS and the CPU PCB. It’s usually prefaced by an audible ‘cracking’ noise. Deliding the CPU and replacing the thermal paste with better quality paste can help but can also cause problems if the black glue that holds the lid in place is removed or damaged. With this problem in mind der8auer has come up with a possible solution.
Der8auer’s idea is to add a thin spacer between the IHS and the PCB to reduce the space and thusly the potential influence on cracking. Der8auer, known to most of us simply as Roman, being the community spirited guy he is kicked off a forum thread on HWBOT to share his idea with the community, also offering to provide IHS spacers to any interested parties for a nominal fee so they can conduct their own research on the issue.
“It's just a guess but I think the space between IHS and PCB has some kind of influence on the cracking behavior. I made some spacers out of stainless steel. The thickness is 0.10 mm and you can stack them e.g. if you want to use 0.30 mm spacer. Just fix them with a little bit of TIM.”
On the issue of eliminating the space between PCB and IHS, Joe_cool also proposed an idea using copper blocks instead. Clearly there are plenty of overclockers out there looking to resolve cracking on Skylake chips.