Fingerprint Module Auxiliary Structure for Electrode Formation
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Solution Overview
Problem
The manufacturing process of fingerprint identification modules faces challenges such as disconnection and conductive material residue due to the large slope of the piezoelectric layer edges, leading to defects in forming driving electrodes, which affects the yield and reliability of the products.
Innovation Solution
Incorporating an auxiliary structure with a slope portion that gradually decreases in thickness, which contacts the edge of the piezoelectric layer and extends beyond it, allowing for proper exposure and development of the photoresist pattern, thereby preventing disconnection and residual conductive material issues during the etching process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the photoresist pattern is formed directly on the piezoelectric layer with large slope edges, then the manufacturing process is simple, but disconnection and conductive material residue occur during etching
Solution Approach 1:
The patent introduces an auxiliary structure as an intermediary between the piezoelectric layer and the photoresist pattern. This auxiliary structure provides a flat surface for photoresist coating, preventing disconnection and conductive material residue during etching, while maintaining manufacturing simplicity.
Solution Approach 2:
The patent adds a structural dimension by introducing the auxiliary structure that extends beyond the piezoelectric layer edges. This dimensional extension creates a stable platform for photoresist formation, solving the precision issue without complicating the overall manufacturing process.
2Manufacturing precision
If the photoresist pattern extends beyond the piezoelectric layer edge, then exposure and development can be performed properly, but the structure becomes more complex
Solution Approach 1:
The auxiliary structure serves multiple functions: it provides a flat surface for photoresist coating, prevents disconnection during etching, and extends beyond the piezoelectric layer to enable proper exposure. This multi-functionality reduces the need for additional separate structures.
Solution Approach 2:
The patent merges the auxiliary structure with the existing piezoelectric layer assembly, making it an integrated component rather than a separate addition. This merging approach maintains structural simplicity while achieving the required photoresist pattern formation quality.
3Ease of manufacture
If the piezoelectric layer has large slope edges, then the layer can be formed easily, but disconnection and conductive material residue problems occur
Solution Approach 1:
The auxiliary structure acts as a mediator between the piezoelectric layer and the driving electrodes. It provides a stable foundation that prevents disconnection and conductive material residue, ensuring reliable connections while maintaining the ease of piezoelectric layer formation.
Solution Approach 2:
The auxiliary structure provides beforehand cushioning by extending beyond the piezoelectric layer edges and providing additional support area. This prevents disconnection and conductive material residue before they can occur during the etching process.
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 solution effectively avoids disconnection and residual conductive material problems, improving the yield and reliability of the fingerprint identification module by ensuring accurate formation of driving electrodes and preventing the piezoelectric layer from falling off during manufacturing.
Implementation Method 1
the piezoelectric layer is excited by the voltage to generate an inverse piezoelectric effect to send a first ultrasonic wave outward
Implementation Method 2
the piezoelectric layer can convert the second ultrasonic waves into voltage signals
Data Source
Figure 1~3
Figure 4~5B
Figure 5C~6B
AI summary
A fingerprint identification module and a manufacturing method therefor, and an electronic apparatus. The fingerprint identification module comprises a substrate, a piezoelectric material layer, an auxiliary structure and a plurality of first driving electrodes. The piezoelectric material layer is disposed on the substrate, the auxiliary structure is at least in part disposed on the substrate, and the plurality of first driving electrodes are disposed on the piezoelectric material and the auxiliary structure on the side away from the substrate. Each first driving electrode extends along a first direction and passes a first edge of the piezoelectric material layer in the first direction, the plurality of first driving electrodes are arranged at intervals in a second direction, and the auxiliary structure is in contact at least with the first edge and comprises a slope portion, the thickness of the slope portion in the direction perpendicular to the functional substrate being reduced gradually from the first edge in the direction away from the center of the piezoelectric material layer. The problems of wire breaking, residual conducting materials and so on are avoided in the process of forming the plurality of first driving electrodes on the piezoelectric material layer in the fingerprint identification module, so that product yield can be improved.