Hermetic Sensor Packaging for Corrosive Gas Flow Measurement
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Solution Overview
Problem
Existing sensors used in manufacturing systems, such as those for semiconductor applications, are not compatible with aggressive environments like corrosive conditions, high energy plasma, vacuum, and high temperatures, leading to issues with corrosion, material contamination, and adverse effects on gas flow properties.
Innovation Solution
A sensor assembly with a substrate, housing, and sensor die, featuring a hermetic seal and alignment features, uses metal bonds like platinum, tin, indium, copper, and nickel to protect the sensor die from corrosion and maintain accurate gas flow measurements, while minimizing turbulence and leakage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional sensors are used in aggressive manufacturing environments, then they can perform basic measurements, but they suffer from corrosion, material contamination, and short operational life
Solution Approach 1:
The sensor system is divided into two separate components: a sensor die that remains in the aggressive environment for measurements, and a housing that contains electronics and can be replaced. This segmentation allows the sensor die to be optimized for environmental resistance while the housing protects sensitive components
Solution Approach 2:
A substrate serves as an intermediary component between the sensor die and the housing, providing mechanical support, electrical connections, and hermetic sealing. The substrate protects the sensor die from direct exposure to corrosive elements while maintaining measurement capabilities
2Measurement precision
If sensors are placed directly in gas flow paths for accurate measurements, then measurement accuracy improves, but turbulence and flow disruption increase
Solution Approach 1:
The sensor die is designed with localized sensing regions that interact minimally with the gas flow. Only specific areas of the sensor die are exposed to the flow path, allowing accurate measurements while minimizing overall flow disruption and turbulence generation
3Reliability
If hermetic sealing is implemented to protect against corrosion, then environmental resistance improves, but manufacturing complexity increases
Solution Approach 1:
The substrate incorporates integrated sealing structures with distinct geometric features (such as raised edges, recesses, or protrusions) that provide hermetic sealing through mechanical interlocking. These geometric changes create seal interfaces that prevent gas penetration without requiring additional sealing components or complex assembly procedures
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 sensor assembly provides reliable, fast, and accurate gas flow and temperature measurements in aggressive environments by ensuring hermetic sealing, minimizing corrosion, and optimizing sensor positioning to enhance measurement accuracy and longevity.
Implementation Method 1
The housing is coupled to the substrate at the middle region or the outer region to provide a hermetic seal
Implementation Method 2
The sensor die is coupled to the substrate at the inner region via the electrical contact pads
Implementation Method 3
The sensor die is aligned to the substrate via aligning features that align the sensor die relative to the substrate in at least one of a first plane or a second plane
Implementation Method 4
uses metal bonds like platinum, tin, indium, copper, and nickel to protect the sensor die from corrosion
Data Source
AI summary
Certain embodiments of the present disclosure relate to a sensor assembly including a substrate, a housing, and a sensor die. In certain embodiments, the substrate includes an outer region, an inner region, and a middle region between the outer region and the inner region. In certain embodiments, the substrate includes electrical contact pads on at least the inner region. In certain embodiments, the housing is coupled to the substrate at the middle region or the outer region to provide a hermetic seal. In certain embodiments, the sensor die is coupled to the substrate at the inner region via the electrical contact pads. The sensor die is aligned to the substrate via aligning features that align the sensor die relative to the substrate in at least one of a first plane or a second plane.