Wafer Scale Heat Slug System for IC Thermal Management
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Solution Overview
Problem
Conventional integrated circuit (IC) heat spreader manufacturing processes result in low yield and surface flatness issues, leading to inefficient heat dissipation and increased production costs due to difficulties in forming high-purity copper alloys with existing stamping equipment, especially in achieving complete corner filling and maintaining surface flatness for effective thermal interface bonding.
Innovation Solution
A wafer scale heat slug system is developed by dicing an integrated circuit from a semiconductor wafer, forming a heat slug blank, dicing it to match the IC size, attaching it to a substrate, and encapsulating it with a thermal interface material, using existing tools and materials like aluminum or copper alloys, to enhance thermal performance and package integrity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional stamping processes are used to form heat spreaders from high purity copper alloy, then the manufacturing process can be implemented with existing equipment, but the yield is low and surface flatness varies significantly
Solution Approach 1:
The patent changes the material parameter from high purity copper alloy to aluminum or aluminum alloy, which has different formability characteristics that are more suitable for conventional stamping processes. This material substitution enables better surface flatness control and corner filling while maintaining thermal performance through optimized aluminum alloy composition and thickness parameters.
Solution Approach 2:
The patent employs aluminum or aluminum alloy as a composite material alternative to copper alloy, leveraging the specific properties of aluminum (lighter weight, good thermal conductivity, excellent formability) to resolve the contradiction between ease of manufacture and manufacturing precision in stamping processes.
2Shape
If multi-stage manufacturing with high-tonnage machinery is used to completely fill corner locations of the IHS, then corner geometry is achieved, but raw material yield drops to as low as 35%
Solution Approach 1:
The patent changes the material parameter from high purity copper alloy to aluminum or aluminum alloy, which has superior formability and ductility characteristics. This enables complete corner filling in a single stamping stage with minimal material waste, dramatically improving raw material yield from 35% to near 100% while achieving the required corner geometry.
Solution Approach 2:
The patent eliminates the need for multi-stage manufacturing by using aluminum's formability to achieve complete corner filling in a single stamping operation. This segmentation reduction from multiple high-tonnage stages to a single stage minimizes material handling and reduces cumulative material loss.
3Ease of manufacture
If stamping processes are used to form heat spreaders, then existing equipment can be utilized, but significant variation in surface flatness occurs affecting adhesion quality
Solution Approach 1:
The patent changes the material parameter from high purity copper alloy to aluminum or aluminum alloy, which exhibits more favorable formability and springback characteristics during stamping. This results in consistent surface flatness that ensures reliable adhesion quality while continuing to use existing stamping equipment.
4Ease of manufacture
If conventional IHS manufacturing is used, then the process is established, but production cost is high and manufacturing time is long
Solution Approach 1:
The patent changes the material parameter from high purity copper alloy to aluminum or aluminum alloy, which can be processed more efficiently in conventional stamping equipment. This substitution reduces manufacturing complexity, eliminates multi-stage high-tonnage operations, and significantly decreases production time and cost while maintaining established manufacturing frameworks.
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
The wafer scale heat slug system significantly reduces the junction temperature of integrated circuits, improving reliability and enabling more densely packed circuitry without increasing costs, while utilizing existing manufacturing tools and simplifying processes, thus addressing the inefficiencies of conventional heat spreader production.
Implementation Method 1
a conductive material in thermal contact with the backside of a packaged die. This conductive material is often a slug, a heat spreader
Implementation Method 2
A heat spreader is employed to spread and dissipate the heat generated by a die
Implementation Method 3
A thermal interface can include such things as a heat sink or fan
Data Source
AI summary
A method for manufacturing a wafer scale heat slug system includes: dicing an integrated circuit from a semiconductor wafer; forming a heat slug blank equivalent in size to the semiconductor wafer; dicing the heat slug blank to produce a heat slug equivalent in size to the integrated circuit; attaching the integrated circuit to a substrate; attaching the heat slug to the integrated circuit; and encapsulating the integrated circuit.