Processing Phase
Consolidation protocols are the programmed sequences of heat and pressure used to cure raw epoxy prepregs during multi-layer board lamination. Through the execution of thermal press cycles, the material stackup undergoes controlled temperature ramps to manage the resin viscosity and cure kinetics. These schedules must be designed to balance the cooling and heating rates across the entire press load.
An incorrect press profile leads to delamination or excessive board warp.
Physical Transformation
The cycle begins with a low-pressure phase during which the temperature is raised to the liquifying point of the epoxy resin. This fluid state allows the resin to flow into the copper patterns and expel any trapped air before the polymerization reaction begins. Once the resin starts to cross-link, the press increases the mechanical pressure to its maximum value to lock the layers in place.
This high pressure is maintained during the bake phase to ensure complete molecular cross-linking across the laminate. Cooling is then managed slowly to minimize internal stress that would otherwise twist the completed panels.
Layer Adhesion
Proper execution of these cycles ensures that the laminate achieves its rated glass transition temperature. This thermal limit determines the board’s resistance to pad cratering during assembly.
