Multilayer PCB Recognition Mark as Mode Switching Electrode
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing printed wiring boards have a large area dedicated to recognition marks that are not utilized after product completion, occupying valuable space and not contributing to the final device functionality.
Innovation Solution
The printed wiring board incorporates a multilayer structure with recognition marks that are electrically connected to the controller via vias and pads, allowing the recognition marks to be used for generating mode switching signals, thereby utilizing the space for additional functionality after product fabrication.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a large area is allocated to the recognition mark to improve image recognition accuracy, then the recognition accuracy is improved, but the usable area of the printed wiring board is reduced
Solution Approach 1:
The recognition mark is designed to serve dual purposes: it functions as a fiducial marker for image recognition during manufacturing, and simultaneously as an electrode that can be electrically connected to circuit elements. By making the recognition mark electrically conductive and integrating it into the circuit network through vias and wiring layers, the same physical structure performs both recognition and electrical functions, thereby utilizing the previously wasted area effectively.
2Measurement precision
If the recognition mark occupies a large area on the printed wiring board, then the accuracy of image recognition is improved, but the functionality of the final device is compromised due to lost space
Solution Approach 1:
The recognition mark is transformed into a multi-functional element that serves both as a recognition marker and as an active circuit component. The mark can be electrically connected to control circuits, power supply circuits, or signal processing circuits, enabling it to participate in device functionality such as mode switching, status indication, or sensor operations, thereby converting dead space into functional space.
Solution Approach 2:
The recognition mark structure itself is utilized for electrical connections without requiring separate dedicated areas. The same physical mark that is read by imaging systems during manufacturing becomes the electrode or connection point for circuit operations, eliminating the need for additional space for electrical components.
3Adaptability or versatility
If the recognition mark is made electrically connected to the controller via vias and pads, then the space is utilized for additional functionality, but the device complexity increases
Solution Approach 1:
The recognition mark is merged with the existing circuit elements by integrating it into the wiring pattern network. The mark shares common structures with other circuit elements such as pads, vias, and wiring traces, combining the recognition function with electrical connection functions in a unified structure, thereby minimizing additional complexity.
Solution Approach 2:
The same physical structure serves multiple functions: it acts as a recognition marker for manufacturing, as an electrode for electrical connections, and as part of the circuit network for signal processing. This multi-functionality reduces the need for separate components and simplifies the overall device architecture despite the added functionality.
Data Source
AI summary
A printed wiring board includes first, second, and third wiring layers, first and second insulating members, and first and second vias. The first wiring layer includes a recognition mark and a first wiring on a first surface. The second wiring layer includes a first pad and a second wiring. The third wiring layer includes a third wiring. The first via penetrates the first insulating member and electrically connects the recognition mark to the first pad. The second via penetrates the second insulating member and electrically connects the first pad to the third wiring. The first pad and the first and second vias are in a region within an outer perimeter of the recognition mark when viewed from a direction orthogonal to the first surface.