AlSi Packaged Assembly for High Density Power Applications
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Solution Overview
Problem
Conventional semiconductor power modules face challenges in achieving high reliability, small size, low weight, and efficient electrical and thermal performance, especially in harsh environments due to mismatched thermal expansion coefficients between packaging materials and substrates, leading to thermal stress and the need for additional hardware and soldering paste.
Innovation Solution
A packaged assembly utilizing a lightweight, high-thermal-conductivity aluminum silicon case with a double-sided substrate of beryllium oxide or aluminum oxide, secured with epoxy, eliminating the need for hardware and hard soldering paste, and featuring invertible leads and silver thick film vias for enhanced current carrying and thermal management.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If hardware and hard soldering paste are used to attach substrate to package, then mechanical strength and electrical connection are improved, but weight increases and usable substrate area decreases
Solution Approach 1:
The patent removes hardware and hard soldering paste from the attachment process, replacing them with a eutectic solder layer that provides both mechanical strength and electrical connection without the additional weight and area consumption of conventional hardware assemblies
Solution Approach 2:
The patent combines mechanical attachment and electrical connection functions into a single eutectic solder layer, eliminating the need for separate hardware components and their associated mounting structures
2Strength
If hardware and hard soldering paste are used to attach substrate to package, then mechanical strength is improved, but usable substrate area decreases
Solution Approach 1:
The patent removes hardware components that occupy valuable substrate real estate, replacing them with a minimal-footprint eutectic solder attachment method that preserves maximum usable substrate area for circuitry
Solution Approach 2:
The patent transitions from a multi-component three-dimensional hardware assembly to a thin two-dimensional solder layer, dramatically reducing the area consumed on the substrate surface while maintaining attachment strength
3Temperature
If packaging material with good thermal conductivity is used, then thermal management is improved, but coefficient of thermal expansion mismatch causes thermal stress
Solution Approach 1:
The patent changes the material composition parameters of the packaging assembly to achieve CTE matching, selecting materials whose thermal expansion coefficients are within 10% of each other, thereby eliminating thermal stress while maintaining high thermal conductivity for effective heat management
4Ease of manufacture
If conventional packaging materials are used, then manufacturing simplicity is maintained, but thermal expansion mismatch leads to device damage
Solution Approach 1:
The patent modifies material selection parameters to achieve CTE compatibility between substrate and package, preventing thermal stress and device damage while maintaining straightforward manufacturing processes through the use of eutectic solder and conventional packaging techniques
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 reduces weight, minimizes thermal stress, and increases usable area for high-density circuitry, achieving a robust, lightweight, and thermally efficient packaged assembly suitable for high-power applications in extreme environments.
Implementation Method 1
packaged assemblies with power semiconductor devices require packaging of high thermal conductivity in order to maintain useful operation of the devices
Implementation Method 2
a substrate is attached to a package using hardware and hard soldering paste
Data Source
Figure 1A
Figure 1B
Figure 1C
AI summary
A packaged assembly for high density power applications includes a case having shelves on opposing walls, and a double-sided substrate disposed on the shelves of the case, the double-sided substrate having a semiconductor die on a first side of the double-sided substrate and circuit elements on a second side of the double-sided substrate. The case includes aluminum silicon (AlSi). The double-sided substrate is secured to the case by an epoxy. The double-sided substrate a thick film substrate and includes beryllium oxide (BeO) or aluminum oxide (Al2O3). The semiconductor die on the first side of the double-sided substrate is coupled to at least one of the circuit elements on the second side of the double-sided substrate by a through substrate via. The packaged assembly also further includes invertible leads coupled to the double-sided substrate by lead frames.