Semiconductor Device Groove Base Plate Joining Material Thickness Control
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Solution Overview
Problem
Semiconductor devices face challenges in enhancing heat dissipation properties while preventing cracks in the joining material between the base plate and laminated substrate, due to differences in heat expansion coefficients and substrate warping, which affects the thickness and reliability of the joining material.
Innovation Solution
The semiconductor device incorporates grooves in the base plate with inclined projections to control the thickness of the joining material, ensuring it remains within an optimal range (100 μm to 300 μm) and maintains heat dissipation efficiency by filling the grooves with joining material, which adapts to substrate warping and prevents crack formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the height of the projections is increased to increase the thickness of the outer peripheral portion of the joining material, then crack prevention is improved, but the heat conductivity from the metal plate to the base plate deteriorates
Solution Approach 1:
The groove is positioned only in the outer peripheral portion of the base plate, creating local variation in joining material thickness. This allows the outer peripheral region to have increased thickness for crack prevention, while the central region maintains optimal thickness for heat conductivity, thus resolving the contradiction between reliability and energy loss.
2Reliability
If the thickness of the joining material is increased to prevent crack generation, then reliability is improved, but the heat dissipation property deteriorates
Solution Approach 1:
The groove structure creates non-uniform thickness distribution in the joining material, with increased thickness localized to the outer peripheral portion where cracks typically initiate, while the central portion maintains thinner, more heat-conductive thickness. This spatial differentiation resolves the contradiction between reliability improvement and heat dissipation preservation.
3Reliability
If the thickness of the joining material is increased to prevent cracks in the outer peripheral portion, then crack prevention is improved, but the heat dissipation property from the laminated substrate to the base plate deteriorates
Solution Approach 1:
The groove is specifically positioned in the outer peripheral portion of the base plate, creating localized thickness increase only where cracks are most likely to form. This selective thickening prevents cracks in the vulnerable outer region while minimizing the impact on overall heat dissipation, as the central heat conduction path remains relatively unaffected.
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 configuration effectively prevents crack generation and growth in the joining material while maintaining or improving heat dissipation properties, even with large substrate warping, by ensuring a consistent solder thickness and high reliability of the joining material.
Implementation Method 1
As the base plate 102 and laminated substrate 103 of the heretofore described of semiconductor device 101 are different in heat expansion coefficient from one another, heat stress is applied to the joining material 104 due to the heat generation when the semiconductor chips 105 are in operation
Implementation Method 2
there is fear that the heat conductivity from the metal plate 132 to the base plate 102 deteriorates, and that the heat dissipation property from the semiconductor chips 105 to the external deteriorates
Data Source
AI summary
A semiconductor device includes a laminated substrate having circuit boards, an insulating plate, and a metal plate laminated, and warped convexly to the circuit board side; semiconductor chips fixed to the corresponding circuit boards; a base plate having a predetermined disposition region in which the laminated substrate is disposed, grooves disposed in the outer periphery of the disposition region, and projections disposed in positions in the disposition region adjacent to and inside the grooves. The grooves has on the projection side an inclination corresponding to an inclination caused by the warp of the laminated substrate. A joining material fills the space between the metal plate and the disposition region and covers the grooves and projections.