Fingerprint Sensor PCB Layout for Preserving Digitizer Recognition
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Embedding a fingerprint sensor in the rear surface of a display can lead to performance degradation, particularly affecting digitizer recognition and making it difficult to attach the sensor without compromising the digitizer's performance or covering holes with additional flexible printed circuit boards.
Innovation Solution
An electronic device design that includes a fingerprint sensor with multiple circuit boards, where a first circuit board is for digitizer recognition, a second circuit board is for fingerprint recognition, and these boards are electrically connected, allowing the sensor to be embedded without affecting the digitizer's performance by maintaining predetermined air gaps between the sensor and the display and battery.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a hole is formed through multiple layers on the rear surface of the display to embed the fingerprint sensor, then the fingerprint sensor can be attached to the rear surface, but the recognition performance of the digitizer deteriorates in the hole portion
Solution Approach 1:
The fingerprint sensor is divided into multiple independent circuit boards (first circuit board for digitizer recognition, second circuit board for fingerprint recognition, third circuit board for additional functions). This segmentation allows each circuit board to be optimized for its specific function while being integrated into the same sensor module, resolving the conflict between sensor attachment and digitizer performance by distributing functions across separate segments.
Solution Approach 2:
The fingerprint sensor module is designed with multi-functionality by integrating multiple circuit boards that serve different purposes: the first circuit board maintains digitizer recognition capability, the second circuit board performs fingerprint recognition, and the third circuit board provides additional sensing functions. This multi-functional design allows the single sensor module to simultaneously maintain digitizer performance while enabling fingerprint recognition without requiring separate components.
2Reliability
If a predetermined gap is maintained between the display and the fingerprint sensor and between the fingerprint sensor and the battery, then the fingerprint sensor can be attached to the rear surface, but it becomes difficult to cover the hole of the digitizer with an additional flexible printed circuit board
Solution Approach 1:
Multiple circuit boards are merged into a single integrated fingerprint sensor module that is attached as one unit to the rear surface of the display. The first circuit board, second circuit board, and third circuit board are combined within the same sensor housing, eliminating the need for separate flexible printed circuit boards to cover the digitizer hole. This merging reduces structural complexity while maintaining the necessary gaps for proper attachment and functionality.
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
The solution enables the embedding of a fingerprint sensor in the rear surface of a display without degrading the digitizer's performance, ensuring effective recognition of both input devices and fingerprints while maintaining necessary air gaps.
Implementation Method 1
an optical fingerprint sensor that obtains a fingerprint image reflected by light
Data Source
AI summary
An electronic device may include: a display device; a battery; a digitizer positioned between at least the display device and the battery and including a first circuit board; a fingerprint sensor including a second circuit board and a third circuit board; and a processor electrically connected to the display device, the digitizer, and the fingerprint sensor. The first circuit board may include a first conductive pattern for recognizing an input device, the second circuit board may include a second conductive pattern for recognizing the input device, the third circuit board may include a third conductive pattern for recognizing a fingerprint, and the first conductive pattern and the second conductive pattern may be electrically connected. Various other embodiments that can be recognized through the specification are also possible.