Active Device Array Substrate Integrating Photo-Sensors
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Solution Overview
Problem
The conventional method of fabricating liquid crystal display (LCD) active device array substrates requires a high number of photolithography and etching processes (PEPs), which increases costs and reduces competitiveness when integrating photo-sensors.
Innovation Solution
A method for fabricating an active device array substrate that integrates photo-sensors without increasing the number of PEPs, involving the formation of a substrate with distinct areas for display and sensing, where a patterned conductor layer, semiconductor layer, and photosensitive dielectric layer are formed to include source, drain, and photo-sensing electrodes, with specific contact windows and passivation layers to reduce the number of masks and processes needed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If photo-sensors are integrated into LCD panels, then sensing functionality is improved, but the number of photolithography and etching processes increases
Solution Approach 1:
The patent combines the photo-sensor fabrication process with the existing active device array substrate manufacturing process. The photo-sensor is integrated into the sensing area of the substrate, allowing both the display function and sensing function to be fabricated using the same photolithography and etching processes, thereby avoiding additional process steps
Solution Approach 2:
The substrate is designed with dual functionality: a display area for liquid crystal display and a sensing area for photo-sensing operations. This multi-functional design allows the same substrate structure to serve both display and sensing purposes without requiring separate fabrication processes
2Measurement precision
If photo-sensors are disposed densely, then sensing precision is improved, but fabrication complexity increases
Solution Approach 1:
The substrate is divided into distinct display area and sensing area, with the sensing area further segmented into multiple photo-sensor elements. This segmentation allows for dense arrangement of photo-sensors in the sensing area while maintaining separate fabrication considerations for each region, simplifying the overall fabrication 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 approach reduces the number of masks and processes required, lowering fabrication costs and enhancing productivity while integrating photo-sensors effectively, thus improving product integration and competitiveness.
Implementation Method 1
the photo-sensor integrated in the LCD panel senses changes in the intensity of light and outputs corresponding signals
Data Source
AI summary
An active device array substrate is provided. First, a substrate having a display area and a sensing area is provided. Then, a first patterned conductor layer is disposed on the display area of the substrate. A gate insulator is disposed on the substrate. A patterned semiconductor layer, a second patterned conductor layer and a patterned photosensitive dielectric layer are disposed on the gate insulator, wherein the second patterned conductor layer includes a source electrode, a drain electrode and a lower electrode, the patterned photosensitive dielectric layer covering the second patterned conductor layer includes an interface protection layer disposed on the source electrode and the drain electrode and a photo-sensing layer disposed on the lower electrode. A passivation layer is then disposed on the substrate. After that, a third patterned conductor layer including a pixel electrode and an upper electrode is disposed on the passivation layer.