Semiconductor Module Base Plate Warpage Control
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Solution Overview
Problem
In potting-resin-sealed semiconductor modules, warpage occurs due to differences in coefficients of linear expansion between the base plate and conductive patterns, or between components of the same material, leading to reliability issues in power and heat cycle properties.
Innovation Solution
A semiconductor module design that includes a base plate with a metal part and a reinforcing member having a higher Young's modulus than the metal part, along with a resin that matches the expansion coefficient of the base plate, to minimize warpage and improve reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the base plate and conductive pattern are made of different materials to achieve functional requirements, then the electrical and thermal performance is improved, but warpage occurs due to different coefficients of linear expansion
Solution Approach 1:
The patent applies local quality by providing a reinforcing member at specific locations within the base plate where warpage occurs. The base plate has non-uniform structural properties - the reinforcing member is strategically positioned to provide localized support without changing the material composition of the entire base plate, thus maintaining the different-material construction for electrical and thermal performance while addressing warpage at critical locations.
Solution Approach 2:
The patent employs composite materials by combining the base plate material (with specific thermal and electrical properties) with a reinforcing member material that has complementary properties. The reinforcing member is made of a material selected to have a coefficient of linear expansion matched to the base plate, creating a composite structure that leverages the advantages of both materials - the base plate material for functional performance and the reinforcing member material for dimensional stability.
2Shape
If both components are made of the same material to match coefficients of linear expansion, then warpage is reduced, but functional performance deteriorates due to material limitations
Solution Approach 1:
The patent applies segmentation by dividing the base plate structure into two functional segments: the base plate itself (made of material optimized for electrical and thermal performance) and the reinforcing member (made of material optimized for dimensional stability). This segmentation allows each segment to be made of the most appropriate material for its specific function, avoiding the need to compromise the base plate material composition for warpage control.
Solution Approach 2:
The patent uses composite materials to combine the functional advantages of different materials. The base plate is made of a material with superior electrical and thermal properties, while the reinforcing member is made of a material with matched thermal expansion properties. Together, they form a composite structure that achieves both functional performance and warpage control.
3Ease of manufacture
If the case is bonded to the base plate and sealed with potting resin in the conventional manner, then the manufacturing process is simple, but reliability in power cycle and heat cycle properties deteriorates due to uncontrolled warpage
Solution Approach 1:
The patent applies preliminary action by incorporating the reinforcing member into the base plate during the base plate fabrication process, before the bonding and sealing operations. This preliminary structural reinforcement ensures that warpage is controlled from the outset, preventing reliability issues in subsequent power and heat cycle operations without complicating the overall manufacturing process.
4Stability of the object's composition
If a reinforcing member with higher Young's modulus is added to the base plate to reduce warpage, then structural stability is improved, but device complexity increases
Solution Approach 1:
The patent applies local quality by adding the reinforcing member only at specific critical locations within the base plate where warpage occurs, rather than uniformly throughout the entire base plate. This localized reinforcement provides the necessary structural stability while minimizing the increase in device complexity and material usage.
Solution Approach 2:
The patent uses composite materials to enhance structural stability without significantly increasing complexity. The reinforcing member is integrated into the base plate structure, creating a composite that leverages the high Young's modulus of the reinforcing material at strategic locations, providing rigidity and warpage control where needed while maintaining the overall simplicity of the base plate design.
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 solution effectively reduces warpage and enhances the reliability of the semiconductor module by matching the expansion coefficients and using a reinforcing member to stabilize the base plate, thereby improving power and heat cycle properties.
Implementation Method 1
a reinforcing member provided in the metal part and having a Young's modulus which is higher than a Young's modulus of the metal part
Implementation Method 2
When the base plate and a conductive pattern are made of different materials, both have different coefficients of linear expansion, and this causes considerable warpage due to heat
Implementation Method 3
resin sealing the fixed surface of the base plate, the insulating substrate, the first and second conductive patterns, the semiconductor chip, and the wiring member
Data Source
AI summary
A base plate (1) includes a fixed surface and a radiating surface which is a surface opposite to the fixed surface. An insulating substrate (3) is bonded to the fixed surface of the base plate (1). Conductive patterns (4,5) are provided on the insulating substrate (3). Semiconductor chips (7,8) are bonded to the conductive pattern (4). An Al wire (12) connects top surfaces of the semiconductor chip (8) to the conductive pattern (5). The insulating substrate (3), the conductive patterns (4 ,5), the semiconductor chips (7 to 10) and the Al wires (11 to 13) are sealed with resin (16). The base plate (1) includes a metal part (19) and a reinforcing member (20) provided in the metal part (19). A Young's modulus of the reinforcing member (20) is higher than a Youngs modulus of the metal part (19).