Test Pads for Fingerprint Sensor Qualification
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current electronic devices integrating fingerprint identification and display functions face challenges in efficiently testing and qualifying the sensing units, leading to potential unqualified products and reduced overall qualification rates.
Innovation Solution
The electronic device incorporates a substrate with first pads and test pads electrically connected to sensing units, allowing for the transmission of test signals to check the functionality of the sensing units, which can be done after fabrication or after substrates are adhered and liquid crystal is filled, thereby improving the qualification process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If sensing units are integrated into the electronic device without dedicated test pads, then device complexity is reduced, but manufacturing precision and qualification rate deteriorate due to inability to effectively test sensing unit functionality
Solution Approach 1:
The patent divides the testing function from the main device structure by adding separate test pads that are electrically connected to sensing units through signal lines. This segmentation allows independent testing of sensing units without affecting the overall device structure, enabling effective quality control while maintaining device simplicity.
Solution Approach 2:
The patent introduces test pads as intermediary elements between the external testing equipment and the sensing units. These test pads serve as mediators that enable signal transmission for testing purposes without requiring direct access to the sensing units, thus facilitating quality control while preserving the integrated device architecture.
2Device complexity
If testing is performed after final assembly, then device complexity is minimized, but reliability deteriorates due to inability to detect unqualified sensing units early in the manufacturing process
Solution Approach 1:
The patent implements preliminary testing capability by providing test pads that allow sensing units to be tested at various stages of the manufacturing process, including after substrate fabrication and before final assembly. This preliminary action enables early detection of defective sensing units, ensuring higher product reliability while maintaining simple device architecture.
Data Source
AI summary
An electronic device includes a substrate, a plurality of first pads, a plurality of sensing units and a plurality of test pads. The first pads are disposed on the substrate, the sensing units are disposed on the substrate and electrically connected to the first pads, and the test pads are disposed on the substrate and electrically connected to the sensing units.