Switching Power Module Packaging for Thermal Cycle Crack Resistance
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Solution Overview
Problem
Conventional switching power modules fail to maintain reliability under large temperature cycles due to cracking of the passivation layer, which is exacerbated by high power density and miniaturization trends in circuit boards, leading to potential failure.
Innovation Solution
A three-layer packaging structure for the integrated circuit layout layer of the die, comprising a mixed layer of undoped silicate glass and tetraethyl orthosilicate, silicon oxynitride, and ultraviolet silicon nitride, which provides improved thermal stress resistance and isolation, reducing the risk of cracking.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional passivation layer is used on the die, then the die is protected during normal operation, but the passivation layer cracks under large temperature cycles, causing switching power module failure
Solution Approach 1:
The patent applies composite materials by using a packaging layer composed of multiple material layers including undoped silicate glass and tetraethyl orthosilicate mixed layers. This composite structure provides both protection and thermal stress resistance, preventing cracking under temperature cycles while maintaining die protection functionality.
Solution Approach 2:
The patent changes material parameters by using a mixed layer of undoped silicate glass and tetraethyl orthosilicate with specific ratios. This parameter change enables the packaging layer to have both good filling properties and excellent thermal stress resistance, allowing it to withstand temperature cycles without cracking.
2Volume of moving object
If power density is increased for miniaturization in 5th generation communications technology, then device size is reduced, but temperature difference increases, causing passivation layer cracking
Solution Approach 1:
The patent uses composite materials in the packaging layer to address the thermal challenges of miniaturization. The mixed layer of undoped silicate glass and tetraethyl orthosilicate provides thermal stress resistance, enabling the module to handle higher power density and temperature differences without passivation layer cracking.
Solution Approach 2:
The packaging layer acts as an intermediary between the die and the external environment. It mediates the thermal stress caused by high power density and miniaturization, protecting the die and passivation layer from temperature-induced cracking while maintaining the compact form factor.
3Ease of manufacture
If the packaging layer uses a single material, then manufacturing is simple, but thermal stress resistance is insufficient under large temperature cycles
Solution Approach 1:
The patent employs composite materials with a mixed layer of undoped silicate glass and tetraethyl orthosilicate in the packaging layer. This composite structure provides excellent thermal stress resistance for withstanding large temperature cycles, while the manufacturing process remains feasible through established semiconductor packaging techniques.
Solution Approach 2:
The patent applies local quality by using different material layers with specific functions in different regions of the packaging structure. The mixed layer of undoped silicate glass and tetraethyl orthosilicate is specifically positioned to provide thermal stress resistance where needed, while maintaining overall manufacturing simplicity.
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 packaging layer effectively withstands temperature changes between -40°C and 100°C, maintaining the integrity of the die and enhancing the reliability of the switching power module without cracking, even after 1000 cycles.
Implementation Method 1
the mixed layer of the undoped silicate glass and the tetraethyl orthosilicate has a good thermal stress effect. Therefore, when a relatively large temperature difference cycle change occurs during working of the die, the first material layer does not crack
Implementation Method 2
the first material layer is filled in a gap between metal protrusions of the integrated circuit layout layer, thereby improving an isolation effect between the metal protrusions
Data Source
AI summary
The technology of this application relates to a switching power module that includes a substrate, a die embedded in the substrate, and a packaging layer. The packaging layer covers an integrated circuit layout layer of the die. The packaging layer packages the integrated circuit layout layer of the die, the die includes a composite material layer covering the integrated circuit layout layer, and the composite material layer includes at least two material layers that have different functions. The at least two material layers include a first material layer covering the integrated circuit layout layer, the first material layer is a mixed layer of undoped silicate glass and tetraethyl orthosilicate, and the first material layer is filled in a gap between metal protrusions of the integrated circuit layout layer, thereby improving an isolation effect between the metal protrusions. The mixed layer of the undoped silicate glass and the tetraethyl orthosilicate has a good thermal stress effect.