Leadless Pressure Sensor With Layered Substrate Fluid Channels
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Solution Overview
Problem
There is a need for pressure sensor systems that can be housed in small, space-efficient packages, allowing gas or liquid to reach both sides of the pressure sensor die, which is essential for various applications including absolute, gauge, and differential pressure configurations, while maintaining cost and size efficiency.
Innovation Solution
A pressure sensor system design featuring a substrate with through-holes and slots that connect to a backside cavity of the pressure sensor die, allowing for the attachment of a cap that divides the system into chambers, enabling fluid communication and measurement of differential pressures, with the substrate and cap formed from materials like ceramic, silicon, or plastic to minimize leakage and maximize space efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If a pressure sensor system uses a small, space-efficient package, then the board space consumption is reduced, but it becomes difficult to allow gas or liquid to reach both sides of the membrane for differential pressure measurements
Solution Approach 1:
The patent transitions from a planar two-dimensional package layout to a three-dimensional structure by stacking components vertically. The substrate, pressure sensor die with membrane, and cap are arranged in layers along the vertical dimension, allowing fluid access ports to be positioned on the same board footprint while maintaining differential pressure measurement capability through vertical fluid pathways.
Solution Approach 2:
The pressure sensor die is nested within a package structure formed by the substrate and cap. The membrane is positioned within the package cavity, with fluid access channels integrated into the substrate and cap walls. This nesting allows the complete differential pressure sensing system to be contained in a compact volume that occupies minimal board space while maintaining full functionality.
2Volume of stationary object
If a pressure sensor system uses a compact package design, then the overall system size is reduced, but the complexity of forming passages to reach the backside cavity increases
Solution Approach 1:
The package is segmented into distinct functional layers: substrate with first fluid access ports, pressure sensor die with membrane and backside cavity, and cap with second fluid access ports. Passages are formed separately in each layer (substrate passages, cap passages) rather than attempting to form complex three-dimensional passages through a single monolithic structure, reducing manufacturing complexity.
Solution Approach 2:
Passages are pre-formed in the substrate and cap during their respective manufacturing processes before final assembly. The substrate is manufactured with integrated fluid access channels leading to the membrane, and the cap is manufactured with corresponding channels. This preliminary formation of passages eliminates the need for complex post-assembly machining or drilling operations.
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 design allows for compact, cost-effective pressure sensor systems capable of measuring differential, gauge, or absolute pressures by ensuring gas or liquid can reach both sides of the membrane, enhancing the versatility and efficiency of pressure sensor configurations.
Implementation Method 1
The pressure from the gas or liquid can cause the membrane to change shape, thereby inducing a change in the pressure-sensitive structure. This change can then be measured to determine a net pressure on the membrane.
Data Source
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AI summary
Pressure sensor system that includes a pressure sensor die (100) and other components (530) in a small, space-efficient package, where the package allow gas or liquid to reach either or both sides of a membrane (110) of the pressure sensor die (100). The package can include a substrate (200) and a cap (300), where either or both the substrate (200) and the cap (300) divide the package internally into two chambers (312, 314). The substrate (200) can have a solid bottom layer (238), a middle layer (236) having a slot or path (211) running a portion of a length of the layer, and a top layer (234) having two through-holes (214, 218) that provide access to the slot or path (211). The cap (300) can have two ports (320, 330). A second port (330) can lead to the second chamber (314) where a top side of a pressure sensor (100) is in the second chamber (314). A first port (320) can lead to a first chamber (314) and the slot or path (211), wherein the slot or path (211) leads to a bottom side of the pressure sensor (100).