Dam Structure for Die Alignment in Semiconductor Encapsulation
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Solution Overview
Problem
Existing semiconductor packaging technologies face challenges in preventing die shifting during material flow, leading to misalignment and potential substrate failure due to asymmetric pressure and flow rates, which legacy predictive compensation and die bonding film optimization cannot adequately address, especially for tight bump pitch scaling and sub-micron die shifts.
Innovation Solution
A dam structure is created on the substrate to encircle or partially surround the die, moderating material flow rates and pressures, ensuring symmetric pressure distribution and reducing the risk of die shifting by confining the material flow within a cavity, which can be made of copper or other materials and designed based on the geometry of the die and substrate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If material is flowed onto the substrate during encapsulation, then the die is encapsulated and protected, but asymmetric pressure and flow rates cause die shifting and misalignment
Solution Approach 1:
A dam structure is introduced as an intermediary element between the material flow and the die. The dam moderates the material flow rates and pressures, creating a more symmetric pressure distribution around the die during encapsulation. This intermediary structure prevents direct asymmetric pressure application to the die, thereby eliminating die shifting while maintaining encapsulation protection.
Solution Approach 2:
The dam structure is formed on the substrate before the die is attached and before the encapsulation material is flowed. This preliminary action prepares the substrate to control material flow in advance, ensuring that when encapsulation material is applied, the pressure distribution is already optimized to prevent die shifting.
2Manufacturing precision
If predictive compensation and die bonding film optimization are used, then some die shifting is addressed, but sub-micron die shifts and tight bump pitch scaling cannot be adequately prevented
Solution Approach 1:
The dam structure serves as a physical intermediary that directly controls material flow dynamics, providing more effective prevention of sub-micron die shifts compared to chemical optimization of bonding films alone. The dam creates mechanical constraints on pressure distribution that are more reliable for tight bump pitch scaling.
3Reliability
If a dam structure is added to moderate material flow, then die shifting is prevented, but device complexity increases
Solution Approach 1:
The dam structure modifies the physical parameters of material flow (pressure distribution and flow rates) in the encapsulation process. By changing these flow parameters through the dam's geometric configuration, symmetric pressure is achieved around the die, preventing die shifting without requiring complex active control systems.
Data Source
AI summary
Embodiments described herein may be related to apparatuses, processes, and techniques for a dam structure on a substrate that is proximate to a die coupled with the substrate, where the dam decreases the risk of die shift during encapsulation material flow over the die during the manufacturing process. The dam structure may fully encircle the die. During encapsulation material flow, the dam structure creates a cavity that moderates the different flow rates of material that otherwise would exert different pressures the sides of the die and cause to die to shift its position on the substrate. Other embodiments may be described and/or claimed.