Heat Sink Attachment Using Elastic Adhesive Support Bars
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Solution Overview
Problem
Current heat spreader designs for semiconductors occupy significant substrate space, contribute to mechanical stress due to thermal coefficient mismatch, and require multiple sizes, leading to increased costs and complexity.
Innovation Solution
The integration of support bars made from elastic adhesive materials with high aspect ratios, allowing for attachment of a thin, flat heat slug that forms a continuous thermally conductive layer across integrated circuits, eliminating the need for legs or additional substrate space and reducing mechanical stress.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If traditional heat spreaders with lips or legs are used, then structural support is provided, but substrate space is occupied and weight increases
Solution Approach 1:
The patent removes the traditional lip or leg structures from heat spreaders, extracting only the essential heat dissipation function. The heat spreader becomes a simple flat plate that contacts the semiconductor device directly, eliminating unnecessary structural elements that occupied substrate space while maintaining sufficient structural support through the adhesive bonding mechanism.
Solution Approach 2:
The adhesive layer serves multiple functions: it bonds the heat spreader to the semiconductor device, provides thermal conduction path, and eliminates the need for separate support structures. This multi-functional approach consolidates structural support and thermal management into a single integrated solution.
2Strength
If heat spreaders with lips or legs are used, then structural support is provided, but cost increases
Solution Approach 1:
By removing complex lip and leg structures, the heat spreader design is simplified to a basic flat plate geometry. This extraction of unnecessary features reduces manufacturing complexity, material usage, and assembly steps, directly lowering production costs while maintaining adequate structural support through adhesive bonding.
Solution Approach 2:
The invention changes the structural parameters of the heat spreader from three-dimensional structures with legs/lips to a two-dimensional flat plate configuration. This parameter change simplifies manufacturing processes and reduces material requirements, leading to cost reduction while the adhesive layer compensates for structural simplification.
3Temperature
If heat spreaders are attached directly to semiconductor substrate, then heat dissipation is improved, but solder mask cracking and copper tracer damage occur due to thermal expansion mismatch
Solution Approach 1:
The adhesive layer acts as an intermediary between the heat spreader and the semiconductor substrate. This intermediate layer buffers the thermal expansion mismatch stresses, preventing direct stress transmission to the solder mask and copper tracers, thereby preventing cracking and damage while maintaining effective thermal conduction.
Solution Approach 2:
The adhesive layer provides beforehand cushioning by being positioned between the heat spreader and substrate before thermal cycling occurs. It pre-compensates for thermal expansion differences, cushioning against stress concentrations that would otherwise cause solder mask cracking and copper tracer damage during thermal stress testing.
4Adaptability or versatility
If multiple sizes of heat spreaders are manufactured to fit different semiconductors, then customization is achieved, but manufacturing complexity and storage requirements increase
Solution Approach 1:
The heat spreader design adopts a universal flat plate configuration that can accommodate different semiconductor devices through variation of adhesive layer thickness or heat spreader surface area, rather than requiring completely different structural designs. This universal base design reduces the number of unique components needed while maintaining adaptability.
Solution Approach 2:
Instead of changing the structural geometry (legs, lips, contours) for different semiconductor sizes, the invention changes only the dimensional parameters such as heat spreader surface area and adhesive layer thickness. This parameter-based customization maintains manufacturing simplicity and reduces storage requirements compared to structurally diverse heat spreader designs.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This design enhances heat dissipation by minimizing substrate area usage, reduces mechanical stress, and simplifies manufacturing by eliminating the need for various heat spreader sizes, resulting in a cost-effective and efficient heat management system.
Implementation Method 1
A plurality of adhesive structures is formed. A heat sink is attached to the plurality of adhesive structures
Implementation Method 2
The integration of support bars made from elastic adhesive materials with high aspect ratios
Data Source
AI summary
An integrated circuit package system includes providing a substrate. An integrated circuit is attached to the substrate. A plurality of support bars is formed on the substrate. A plurality of adhesive structures is formed. A heat sink is attached to the plurality of adhesive structures. The integrated circuit is encapsulated. The support bars are removed.