Semiconductor Package Stress Isolation for Encapsulated Sensors
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Solution Overview
Problem
Sophisticated semiconductor devices are vulnerable to environmental stresses, which can adversely affect their sensitive circuitry and features, and existing technologies have not effectively minimized these effects.
Innovation Solution
A semiconductor device package is designed with stress isolation by forming a low modulus isolation material around the perimeter of the device and creating an isolation cavity within an encapsulant, with a second low modulus material filling the cavity to protect the sensor from stress induced by the encapsulant, while also using reinforcement structures for additional support.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an encapsulant is used to protect the semiconductor device, then the device is protected from environmental conditions, but stress is induced on the sensor affecting its performance
Solution Approach 1:
A low modulus isolation material is introduced as an intermediary between the sensor and the encapsulant. This isolation material has a lower modulus of elasticity than the encapsulant, allowing it to absorb and isolate stress while the encapsulant provides environmental protection. The isolation material acts as a stress buffer that protects the sensor from stress induced by the encapsulant.
2Ease of manufacture
If the sensor is directly encapsulated, then manufacturing is simplified, but the sensor is exposed to stress and contaminants
Solution Approach 1:
The encapsulation structure is segmented into multiple functional layers: the encapsulant layer for environmental protection, the low modulus isolation material layer for stress isolation, and the sensor layer for sensing functionality. This segmentation allows each layer to perform its specific function independently, with the isolation material layer protecting the sensor from both stress and contaminants while maintaining manufacturing feasibility.
3Strength
If a rigid structure is used for support, then structural strength is improved, but stress is transmitted to the sensor
Solution Approach 1:
The structural support system uses materials with different local qualities - the encapsulant provides rigid structural support with high strength, while the isolation material provides a locally softer, low modulus region that prevents stress transmission to the sensor. This local quality differentiation allows the structure to simultaneously provide strength and stress isolation.
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 isolates the semiconductor device from potential stress and contaminants, ensuring the integrity and performance of the sensitive circuitry by minimizing the impact of environmental conditions and providing structural support.
Implementation Method 1
a low modulus isolation material is formed around a perimeter of the sensor... such that the sensor is isolated from potential stress induced by the encapsulant
Data Source
AI summary
A semiconductor device package having stress isolation is provided. The semiconductor device package includes a package substrate and a sensor attached to the package substrate. A first isolation material is formed around a perimeter of the sensor. An encapsulant encapsulates at least a portion of the first isolation material and the package substrate.