Compact Flow Sensor Package with Integrated Dielectric Membrane
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Solution Overview
Problem
Conventional thermal fluid flow sensors are bulky, making them unsuitable for space-constrained applications such as handheld devices, and existing packaging solutions do not provide a compact and cost-effective means for electrical connections.
Innovation Solution
A flow sensor package comprising a first substrate with an etched portion and a dielectric membrane, and a second substrate that forms a sensing channel with the first substrate, allowing for a compact design with flip-chip configuration and conductive joints for electrical connections, enabling a more compact and cost-effective system.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If conventional packaging solutions are used for thermal fluid flow sensors, then the sensor can be manufactured with standard processes, but the package becomes bulky and unsuitable for space-constrained applications
Solution Approach 1:
The patent merges the sensing element, flow channel, and electrical connection substrate into a single integrated package. The sensing element is mounted directly on the substrate that also forms the flow channel walls, eliminating the need for separate packaging components. This integration reduces the overall package volume while maintaining manufacturability through standard semiconductor fabrication processes.
Solution Approach 2:
The patent implements a nested structure where the flow channel is formed within the substrate itself, and the sensing element is positioned within the flow channel region. The electrical connections are routed through the substrate layers, creating a compact nested arrangement where each component is contained within or alongside the others, minimizing the overall package footprint.
2Device complexity
If standard wire bonding or through-hole methods are used for electrical connections, then reliable electrical connections can be achieved, but the device complexity and size increase
Solution Approach 1:
The patent extracts the electrical connection function from separate wiring components and integrates it directly into the substrate structure. Conductive traces are formed as part of the substrate fabrication process, and connection pads are directly accessible on the substrate surface. This eliminates wire bonds and through-hole assemblies, reducing device complexity while maintaining connection reliability through direct metallurgical bonds.
3Volume of moving object
If the sensing element and flow channel are separated into different components, then manufacturing flexibility is improved, but the overall package size increases
Solution Approach 1:
The substrate serves multiple functions simultaneously: it provides the structural framework, forms the flow channel walls, supports the sensing element, and provides electrical connection pathways. This multi-functionality allows the same component to fulfill multiple roles that would traditionally require separate parts, reducing package volume while maintaining the manufacturing flexibility needed for different sensor configurations.
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 provides a more compact and cost-effective flow sensor package with improved electrical connections, suitable for space-constrained applications, while maintaining sensitivity and accuracy in fluid flow measurement.
Implementation Method 1
a dielectric region located on a first side of the first substrate, wherein the dielectric region comprises at least one dielectric membrane
Implementation Method 2
thermal fluid flow sensors utilise the thermal interaction between the sensor itself and the fluid
Data Source
AI summary
We disclose herein a flow sensor comprising: a first substrate comprising an etched portion, a dielectric region located on a first side of the first substrate, wherein the dielectric region comprises at least one dielectric membrane located over the etched portion of the first substrate, a sensing element located on or within the dielectric membrane, and a second substrate adjoining a second side of the first substrate. The first side of the first substrate and the second side of the first substrate are opposite sides. The first substrate and the second substrate cooperate to form a sensing channel through the flow sensor.