Intel is expected to return to using solder or a high-grade thermal epoxy as the thermal interface material between the die and heatspreader in its upcoming Haswell-E processor family, after swapping to a thermal grease solution on previous models.
The metal lid of the heatspreader sits above the die on most modern processors, offering both protection to the fragile silicon and an increased surface area for the heatsink to which it will be connected. A heatspreader only improves performance if it makes a better connection to the die than the heatsink would have, however, and that can depend entirely on the means by which the two are joined.
Previously, Intel has soldered its heatspreaders directly to the die, creating a strong bond at the molecular level that ensures good heat transfer. In its Ivy Bridge family, it moved to using a thermal paste with an impact in heat transfer and a sudden resurgence of interest in de-lidding accessories
. Although many considered the move to have been made out of a desire to boost profits, there were sound engineering reasons relating to smaller die sizes causing cracking of the solder and the formation of heat-trapping voids that can damage the chip.
Those issues appear to have been resolved in time for the Haswell-E enthusiast chip family, thankfully. An image published by OCDrift
shows a de-lidded Core i7-5960X Haswell-E processor with half the die stuck to the heatspreader - suggesting that solder or an extremely strong thermal epoxy, rather than the weak-adhesive thermal paste of previous chips, has been used to join the two.
Intel, naturally, is not commented on unannounced products, with rumours suggesting the Core i7-5960X will be formally launched in September this year - with or without the claimed new heatspreader interface material.