Semiconductor Package Stiffener Grooves for Adhesive Overflow Control
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Solution Overview
Problem
Existing semiconductor packages face issues with warpage due to insufficient or excessive thermal interface material, leading to adhesive strength and thermal conductivity problems, as well as process defects from material overflow.
Innovation Solution
A semiconductor package design featuring a stiffener with reinforcement rods and adhesive receiving grooves that control the flow of adhesive material, preventing overflow and ensuring adequate coverage while reinforcing the package substrate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If thermal interface material is used to attach stiffener to package substrate, then adhesive strength and thermal conductivity are improved, but material overflow causes process defects
Solution Approach 1:
The stiffener is divided into a body portion and a protruding portion that extends downward from the bottom surface. This segmentation creates a structured flow path for the thermal interface material, guiding it to fill the gap between the stiffener body and substrate while preventing uncontrolled overflow beyond the protruding portion's boundaries.
Solution Approach 2:
The protruding portion is positioned at specific locations on the stiffener's bottom surface where overflow control is most needed. This local structural modification creates zones of controlled material containment, allowing the thermal interface material to be retained at critical areas while maintaining overall adhesive coverage.
2Temperature
If thermal interface material is used to attach stiffener to package substrate, then thermal conductivity is improved, but material overflow occurs from package substrate
Solution Approach 1:
The protruding portion is pre-formed on the stiffener before assembly, creating a built-in overflow barrier that proactively prevents thermal interface material from escaping the intended bonding area. This preliminary structural feature ensures that even with excessive material application, overflow is contained.
3Object-generated harmful factors
If insufficient thermal interface material is used, then overflow is prevented, but adhesive strength and thermal conductivity are reduced
Solution Approach 1:
The protruding portion automatically performs dual functions: it guides the thermal interface material into the gap between the stiffener body and substrate, and simultaneously contains any excess material. This self-regulating structure eliminates the need for precise material quantity control by the operator.
Data Source
AI summary
A semiconductor package may include a package substrate including mounting region and an edge region surrounding the mounting region, one or more semiconductor devices on the mounting region of the package substrate, a stiffener on the edge region of the package substrate, the stiffener having a first surface facing the package substrate and a second surface opposite to the first surface, and an adhesive member between the package substrate and the stiffener to attach the stiffener to the package substrate. The stiffener includes a reinforcement rod that reinforces the package substrate and adhesive receiving grooves in a lower edge portion of the reinforcement member that are exposed from side portions of the reinforcement member, and each of the adhesive receiving grooves has a depth from the first surface of the stiffener to accommodates a portion of the adhesive member.