Publishing Venue
The IP.com Prior Art Database
Abstract
During technology development, a new reliability failure mechanism was discovered in which the solder on the die-side capacitors (DSC) would bridge and short to the heat spreader during the attachment of the interposer. The root cause of the failure mechanism was identified as TIM spreading onto the DSCs. During a surface mount reflow the thermal interface material on the DSC expands, and the solder melts and is pushed on top of the capacitor (see Figure 2). Preventing solder doming during surface mount reflow requires the integrated heat spreader (IHS) module to significantly reduce the amount of TIM spread while ensuring complete die coverage and good reliability performance.
Method for minimizing thermal interface material spread by
using a heat spreader
Background
During technology development, a new reliability failure
mechanism was discovered in which the solder on the die-side capacitors (DSC)
would bridge and short to the heat spreader during the attachment of the
interposer. The root cause of the failure mechanism was identified as TIM
spreading onto the DSCs. During a surface mount reflow the thermal interface
material on the DSC expands, and the solder melts and is pushed on top of the
capacitor (see Figure 2).
Preventing solder doming during surface mount reflow requires the
integrated heat spreader (IHS) module to significantly reduce the amount of TIM
spread while ensuring complete die coverage and good reliability performance.
Description
Disclosed is a method for minimizing thermal interface material
(TIM) spread by designing a heat spreader with modifications to the cavity
shape. Preventing the thermal
interface material spread can improve reliability performance and prevent
contact with other integrate circuit package components. The
disclosed method addresses the problem of DSC solder doming caused by TIM
spreading over the DSC solder pad.
This problem is conventionally addressed through tight process controls.
The amount of TIM dispensed on the die is limited and wide exclusion zones on
the package leave a 2-3 mm of area around the perimeter of the die for the
thermal interface material to spread.
Two techniques are disclosed to...
