Capacitive Micro-Sensor Adhesive Bonding for ASIC Protection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Miniature environmental sensors in electronic devices face challenges due to the mismatch in feature sizes between sensors and associated ASICs, requiring separate manufacturing and assembly, while needing protection from environmental elements without compromising sensing capabilities.
Innovation Solution
A micro-sensor device is fabricated with a passivation-protected ASIC module and a micro-sensor module bonded to a patterned cap using a chemically compatible adhesive, allowing exposure of sensing elements to the environment while protecting signal conditioning circuitry.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the micro-sensor and ASIC are manufactured separately on different substrates, then the manufacturing precision requirements for each can be independently optimized, but the device complexity increases due to separate manufacturing and assembly processes
Solution Approach 1:
The device is divided into two separate modules: a micro-sensor module with capacitive sensing elements and an ASIC module with signal conditioning circuitry. Each module is manufactured independently on separate substrates, allowing independent optimization of manufacturing processes for each module's specific requirements.
Solution Approach 2:
A cap structure serves as an intermediary element that bonds to both the micro-sensor module and the ASIC module. This cap provides mechanical support, environmental protection, and a bonding interface, facilitating the assembly of separately manufactured modules into a functional integrated device.
2Reliability
If the ASIC module is protected from environmental elements, then the reliability of signal conditioning circuitry improves, but the sensing elements must remain exposed to accurately sense ambient conditions
Solution Approach 1:
The cap structure implements selective protection: it provides environmental sealing and protection for the ASIC module while containing openings or transparent regions that allow the capacitive sensing elements to remain exposed to ambient environmental conditions for accurate sensing.
Solution Approach 2:
The protective cap is designed with segmented or patterned structure that differentiates between regions requiring protection (ASIC area) and regions requiring environmental exposure (sensing element area), allowing simultaneous fulfillment of both protection and sensing requirements.
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 solution ensures accurate ambient environmental sensing while protecting the ASIC module from extreme temperatures, pressure fluctuations, and humidity, enhancing the reliability and performance of miniature sensors in electronic devices.
Implementation Method 1
The patterned cap can be bonded to the micro-sensor module using a planarizing adhesive that is chemically compatible with the sensing elements
Data Source
AI summary
A micro-sensor device that includes a passivation-protected ASIC module and a micro-sensor module bonded to a patterned cap provides protection for signal conditioning circuitry while allowing one or more sensing elements in the micro-sensor module to be exposed to an ambient environment. According to a method of fabricating the micro-sensor device, the patterned cap can be bonded to the micro-sensor module using a planarizing adhesive that is chemically compatible with the sensing elements. In one embodiment, the adhesive material is the same material used for the dielectric active elements, for example, a photo-sensitive polyimide film.