Compensation Method for Die Shift Caused by Flow Drag Force in Wafer-Level Molding Process.

Area of Science:

• Semiconductor manufacturing
• Materials science
• Packaging technology

Background:

• Wafer-level packaging (WLP) is vital for advanced, thin semiconductor devices.
• The WLP molding process suffers from high defect rates and poor predictability.
• Die shift is a primary defect factor impacting final product quality in WLP.

Purpose of the Study:

• To evaluate die shift caused by epoxy molding compound (EMC) flow drag during WLP.
• To develop a predictive model for die shift to improve WLP yield.
• To enable die realignment through accurate die shift prediction and compensation.

Main Methods:

• Experimental and analytical evaluation of die shift at various molding stages.
• Analysis of die movements due to thermal contraction/expansion and warpage.
• Regression analysis to correlate die shift with die gap variations.

Main Results:

• Quantified die shift attributed to EMC flow drag force.
• Established a relationship between die shift and die gap variation.
• Demonstrated the feasibility of predicting die shift based on experimental data.

Conclusions:

• Accurate prediction of die shift is essential for high-yield WLP.
• Understanding EMC flow drag effects is key to minimizing die shift.
• The developed prediction method can facilitate die realignment for improved semiconductor device quality.