Flexible Sensor PCB for Passive Infrared Motion Detector
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Solution Overview
Problem
Existing passive infrared motion detectors have complex structures that result in high costs due to the need for covering large detection areas, making them expensive and potentially inefficient.
Innovation Solution
A compact passive infrared motion detector design featuring a base part with a printed circuit board arrangement, including a flexible sensor printed circuit board and a lens cap, where sensor elements are automatically aligned during assembly using bearing blocks and snap-in hooks, allowing for cost-effective machine soldering and integration with existing systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If a complex structure is used to cover a large detection area, then the detection area is sufficiently covered, but the costs increase
Solution Approach 1:
The sensor printed circuit board is divided into a rigid basic area and two flexible extension areas, allowing the sensor elements to be distributed across a larger effective detection area while maintaining a compact physical structure. The flexible extension areas can be folded or extended to cover more space without requiring a completely large rigid board.
Solution Approach 2:
The sensor printed circuit board utilizes three-dimensional folding configurations where the flexible extension areas can be folded along edges to create a compact storage form factor while expanding to cover a large detection area when deployed. This allows the device to transition between compact and expanded states.
2Manufacturing precision
If manual alignment of sensor elements is performed, then precise alignment is achieved, but production time and costs increase
Solution Approach 1:
The bearing blocks on the base part automatically align the sensor elements with the lens segments during the assembly process. When the sensor printed circuit board is placed on the base part, the bearing blocks guide and position the sensor elements into the correct alignment without requiring manual intervention or complex alignment fixtures.
Solution Approach 2:
The invention replaces manual alignment operations with automated machine soldering processes. The flexible printed circuit board design allows sensor elements to be soldered onto the board using standard machine soldering equipment, which then maintains the alignment through the flexible connections during assembly.
3Stability of the object's composition
If inflexible printed circuit boards are used, then structural stability is maintained, but adaptability in orientation and assembly is reduced
Solution Approach 1:
The printed circuit board is segmented into rigid and flexible portions. The basic area provides structural stability and houses components requiring rigid support, while the flexible extension areas provide adaptability for orientation and assembly variations without compromising the overall structural integrity of the device.
Solution Approach 2:
The printed circuit board transitions from a static rigid structure to a dynamic semi-flexible structure. The flexible extension areas can bend and adapt to different mounting orientations and assembly configurations, allowing the device to be installed in various positions while maintaining electrical connections and structural stability.
Data Source
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AI summary
A passive infrared motion detector is proposed, the base of which is designed to accommodate a printed circuit board assembly. This assembly is equipped with several sensor elements and other components necessary for its operation. A lens cap with multiple lens segments is fitted to the base for covering the sensor. To create a passive infrared motion detector that offers high functional reliability with a simple and cost-effective design, the printed circuit board assembly consists of a main circuit board populated with the necessary components and at least one sensor circuit board, which is at least partially flexible and connected to the main circuit board.