Bottom Side Cooling for Glass Interposer with Chip Embedding using Double-sided Release Process for 6G Wireless Applications

This paper presents a die-embedded glass interposer process using a new double-sided release method. This new method is introduced for CTE balancing and minimum warpage process for 6G wireless applications. In the glass interposer, through cavities are prepared in the glass substrate. Thermal test chip (TTC) is embedded into the through cavity and connected via redistribution layers (RDL) in the topside. A copper heat spreader is attached to the exposed TTC backside using thermal-interface material (TIM) for thermal management. The double-sided release method using two different carriers during the heat spreader attachment is the key to balancing the CTE and minimum warpage. The embedded TTC power density is tested to see the cooling capacity ranging up to ~1W/mm
²
with various heat transfer coefficients ranging between 28.8~261.3 W/m
²
K. This work provides a solution for CTE mismatch during die embedding glass interposer process and provide minimum warpage.