Semiconductor Package Composite TIM for Void-Resistant Heat Transfer

The patent changes the material composition parameters of the TIM layer by incorporating intermetallic compounds (such as Cu6Sn5, Cu3Sn, Au2Sn4) alongside traditional TIM materials. This compositional parameter change allows the TIM layer to maintain thermal conductivity while resisting void formation during reflow processing, as the intermetallic compounds provide structural stability at elevated temperatures

The patent creates a composite TIM layer combining traditional thermal interface materials with intermetallic compounds. This composite structure leverages the thermal conductivity of conventional TIM materials while the intermetallic compounds provide void resistance during reflow, effectively resolving the contradiction between heat transfer efficiency and reliability

The patent applies preliminary action by pre-forming metal features (such as copper or gold layers) on the semiconductor dies before applying the TIM layer. These pre-formed metal features are designed to react with the TIM during subsequent reflow processing, automatically generating the desired intermetallic compounds without requiring additional processing steps. This approach reduces void formation while maintaining relatively simple manufacturing processes

The patent utilizes self-service by allowing the TIM layer and metal features to automatically react and form intermetallic compounds during the standard reflow soldering process. The chemical reaction occurs spontaneously under the reflow conditions, eliminating the need for separate intermetallic formation steps and reducing overall process complexity while achieving the reliability benefit