Optimizing Press Thermal Profiles for High Density Interconnect Coreless Assemblies
Optimizing coreless HDI thermal profiles requires synchronized heating ramps, controlled viscosity dwell windows, and low-rate cooling to prevent warp.
Press Thermal Profiles
Cure Cycle
Time and temperature relationships during the lamination process determine the final mechanical and electrical properties of the cured epoxy resin. Precise press thermal profiles map the rise from room temperature to the glass transition temperature of the material. These data points ensure the resin flows sufficiently to fill all gaps between copper traces before it hardens.
Temperature Management
Heat transfer through the lamination plates must follow a specific slope to prevent the entrapment of volatiles or air. Within press thermal profiles, the dwell time at the melting point is the most critical factor for achieving a low void count. If the temperature rises too quickly, the outer edges of the board might cure while the center is still in a liquid state.
Quality Validation
Recording the actual heat experienced by the laminate via thermocouples provides the evidence needed for process certification. Analysis of press thermal profiles shows whether the cooling rate was controlled enough to prevent warping or internal stress. A slow cooling phase allows the different materials in the stack to contract at rates that minimize the buildup of latent mechanical energy.
Without this record, a fabricator cannot prove that the board reached the necessary cross linking density required for high temperature lead free assembly. This data set also helps in troubleshooting defects like delamination or inconsistent thickness across different production runs.