Spherical Composite Heat Spreader for Stable Semiconductor Contact
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Solution Overview
Problem
Existing heat radiation members for semiconductor elements, such as those made from Mg-SiC, often suffer from poor accuracy in forming spherical warpage, leading to unstable intimate contact with placement targets and reduced heat conduction capabilities due to manufacturing condition dependencies and thermal history-induced deformations.
Innovation Solution
A composite member with specific spherical warpage and sphericity error ranges is manufactured using a die with a radius of curvature between 5000 mm and 35000 mm, heat pressed at temperatures exceeding 200°C under 10 kPa pressure, and cooled in a pressurized state to maintain intimate contact and stability, utilizing a composite material like Mg-SiC with a non-metal content of at least 55% for enhanced thermal conductivity and reduced coefficient of linear expansion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If heat pressing is performed with conventional dies and manufacturing conditions, then the heat radiation member can be produced, but the spherical warpage accuracy is poor and contact stability deteriorates
Solution Approach 1:
The die is pre-designed with a specific spherical curvature radius (5000-35000 mm) to preliminarily establish the desired spherical warpage shape in the heat radiation member during the heat pressing process, ensuring accurate spherical formation before actual use
Solution Approach 2:
The invention changes the manufacturing parameters by controlling the die curvature radius within a specific range (5000-35000 mm) and maintaining pressurization during cooling, which transforms the material behavior to achieve precise spherical warpage and improve both manufacturing precision and contact stability
2Reliability
If the heat radiation member is pressed against the placement target to straighten warpage, then intimate contact is achieved, but the member remains prone to deformation during thermal cycles
Solution Approach 1:
The spherical warpage is preliminarily formed during manufacturing with precise control of the die curvature radius, creating a pre-distorted shape that compensates for expected thermal deformations, thereby maintaining both intimate contact and shape stability during operational thermal cycles
Solution Approach 2:
The invention applies preliminary anti-action by pre-forming a spherical shape that counteracts the expected deformation forces during thermal cycles, preventing future deformation and maintaining stable intimate contact with the placement target
3Ease of manufacture
If conventional heat pressing is used without controlled cooling, then the process is simple, but thermal history-induced deformations occur
Solution Approach 1:
The pressurization is maintained continuously during the cooling process to prevent shape changes, ensuring that the spherical warpage formed during heating is preserved accurately through cooling without thermal history-induced deformations, while adding minimal complexity to the manufacturing process
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 composite member achieves stable intimate contact with placement targets, maintains high thermal conductivity, and is less prone to deformation during thermal cycles or soldering, ensuring effective heat radiation properties over a long period.
Implementation Method 1
the composite member achieves stable intimate contact with placement targets, maintains high thermal conductivity, and is less prone to deformation during thermal cycles or soldering, ensuring effective heat radiation properties over a long period
Implementation Method 2
performing heat pressing by accommodating the substrate material in a die of which radius of curvature is not smaller than 5000 mm and not greater than 35000 mm, the pressing step including maintaining a heating temperature exceeding 200°C and an applied pressure not lower than 10 kPa
Implementation Method 3
performing cooling from the heating temperature to a temperature not higher than 100°C while a state of application of a pressure not lower than 80% of the applied pressure is maintained
Data Source
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AI summary
A composite member includes a substrate composed of a composite material containing a metal and a non-metal. One surface of the substrate has spherical warpage of which radius of curvature R is not smaller than 5000 mm and not greater than 35000 mm. A sphericity error is not greater than 10.0 µm, the sphericity error being defined as an average distance between a plurality of measurement points on a contour of a warped portion of the substrate and approximate arcs defined by the plurality of measurement points. The substrate has a thermal conductivity not lower than 150 W/m·K and a coefficient of linear expansion not greater than 10 ppm/K.