Flexible Printed Circuit Sensor Packaging with Overmolded Cavity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing sensor devices are not compact or cost-effective for mass production, lacking a suitable packaging design that combines flexibility with conventional semiconductor processes.
Innovation Solution
A method involving flexible printed circuit carriers where sensor chips are attached and electrically connected to a flexible foil, which is then encased in a mould with a hardening filler material, allowing for compact and low-cost packaging by replacing traditional wire frames with flexible printed circuit carriers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If a conventional semiconductor packaging process with wire frames is used, then the sensor device can be manufactured, but the device size is large and manufacturing cost is high
Solution Approach 1:
The patent replaces rigid wire frames with a flexible printed circuit carrier that has a thin film structure. This flexible carrier integrates both mechanical support and electrical connection functions, significantly reducing device volume while maintaining ease of manufacture through standard flexible PCB fabrication processes.
Solution Approach 2:
The patent combines multiple functions into the flexible printed circuit carrier: mechanical support for the sensor chip, electrical connection through printed traces, and structural framework for the package. This integration eliminates separate wire frames and reduces overall device complexity.
2Reliability
If a protective housing with encasement body is used, then the sensor chip is protected, but the device size increases and manufacturing cost increases
Solution Approach 1:
The patent nests the sensor chip within the recess of the flexible printed circuit carrier, which itself is enclosed by the overmold. This nested structure provides comprehensive protection while maintaining a compact overall form factor, as each component fits within the previous one rather than adding external bulk.
Solution Approach 2:
The patent uses a composite packaging structure combining the flexible polymer carrier material with the rigid overmold material. This composite approach provides both flexibility for miniaturization and rigidity for protection, achieving reliable sensor chip protection without increasing device size.
3Stability of the object's composition
If a rigid plate structure is used, then the sensor device is stable, but the device lacks flexibility and adaptability for different applications
Solution Approach 1:
The patent transitions from a static rigid plate to a dynamic flexible printed circuit carrier that can be bent, folded, or conformally mounted. This dynamic structure maintains structural stability during operation while enabling various mounting configurations and applications, including curved surfaces and space-constrained environments.
Solution Approach 2:
The flexible printed circuit carrier serves multiple functions across different applications: structural support, electrical interconnection, mechanical coupling to the sensor chip, and even sensing functionality in some implementations. This multi-functionality provides adaptability to various sensor types and application requirements while maintaining a unified stable structure.
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 approach enables the production of compact, low-cost sensor devices with well-defined packaging, suitable for various applications, including humidity, pressure, and gas sensing, while maintaining the integrity of the sensor chip.
Implementation Method 1
The filler material is hardened at least partially, e.g. by crosslinking and/or cooling
Implementation Method 2
The filler material is hardened at least partially, e.g. by crosslinking and/or cooling
Implementation Method 3
The sensor chips are attached to the flexible foil, e.g. by adhesive bonding
Data Source
Figure 1~3
Figure 4~6
Figure 7~8
AI summary
The sensor device comprises a flexible carrier (1) carrying electrical leads 3. A sensor chip (9) is mounted to the carrier (1) and cast into a package (6). The package (6) has been manufactured by applying a mould over the flexible carrier (1), thereby forming a cavity (17) for receiving a hardening filler material. By directly casting the package (6) against the carrier (1), a compact, low-cost and well defined packaging device can be provided.