Custom Packaging Process for High-Viscosity Thermal Interface Materials

Challenge

A manufacturer of power conversion modules for electric vehicles was scaling production of inverter assemblies used in battery systems. The assemblies required a thermally conductive paste applied between power semiconductors and aluminum heat sinks to ensure efficient heat dissipation.

The paste contained ceramic fillers and exhibited extremely high viscosity, exceeding 300,000 cP. Maintaining uniform filler distribution was critical because any separation or trapped air could reduce thermal conductivity and create localized overheating during operation.

The customer originally filled dispensing barrels using home grown solution, this approach created several issues when production volumes increased:

• entrapped air bubbles inside syringes
• inconsistent fill weights
• filler settling during handling
• high labor input

These problems occasionally produced voids in the thermal interface layer during application, reducing thermal performance and forcing rework.

Customers approached several suppliers and asked to mix, degas and package the materials in barrels.

Solution

Altaris Industrial implemented a controlled packaging process designed for high-viscosity thermal materials. The production approach included:

• shear-controlled mixing to maintain homogeneous filler dispersion
• vacuum degassing to eliminate entrapped air
• air-free piston filling of dispensing syringes
• lot traceability and batch documentation

The material was packaged into multiple dispensing formats used in automated assembly lines, including 10cc, 30cc and 55cc industrial syringes.

Results

• Elimination of air voids during dispensing
• Improved consistency of thermal interface layers
• Significant reduction in packaging labor at the customer facility
• Scalable packaging supply supporting production ramp of EV electronics