Stacked Semiconductor Device Coating Curing Method

The patent combines multiple curing/reflow cycles into a single unified thermal process. All NFU layers between stacked devices are cured simultaneously in one thermal cycle rather than sequentially, reducing cumulative thermal stress while maintaining the ability to stack multiple devices. This merging approach preserves productivity while improving reliability by eliminating repeated thermal exposure to lower NFU layers.

The patent applies preliminary heating to raise the temperature of stacked devices to a predetermined temperature (e.g., 100°C to 200°C) before performing the curing/reflow process. This pre-heating step reduces the temperature differential during subsequent thermal processing, minimizing thermal shock and stress on NFU layers, particularly those at lower positions in the stack that would otherwise experience repeated extreme thermal cycles.

The patent merges the curing processes for all NFU layers into a single simultaneous thermal cycle. Instead of curing each NFU layer sequentially as devices are stacked, all layers are cured together in one process, eliminating repeated thermal exposure to lower layers and reducing cumulative thermal stress while maintaining adaptability to stack any number of devices.

The patent changes the thermal processing parameters by implementing a single extended curing cycle with controlled temperature profiles instead of multiple short cycles. The process uses a predetermined temperature range (100°C to 200°C) for pre-heating followed by a unified curing/reflow cycle, altering the thermal parameters to reduce stress accumulation while maintaining the ability to process variable numbers of stacked devices.