Inline Laser Repair of Defective Image Sensor Data Lines
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Defects in thin film deposition and lithographic masking during the manufacturing of sensor arrays lead to electrical opens and shorts in metal transmission lines, causing image quality degradation and unintended artifacts due to floating voltages from environmental noise.
Innovation Solution
A method involving laser-welding and laser-cutting techniques to electrically ground defective data, bias, or gate transmission lines using a metal-dielectric-metal architecture, with specific laser parameters and geometries to prevent floating voltages and improve manufacturing yield.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If traditional manufacturing processes (thin film deposition, lithographic masking, etching) are used to create sensor arrays, then device architecture complexity and functionality are improved, but manufacturing defects (particles, flakes, dust) cause electrical opens and shorts in transmission lines
Solution Approach 1:
The patent implements preliminary testing of sensor arrays during the manufacturing process to identify defective transmission lines before final product completion. By detecting opens and shorts early through test pixel arrays and comparing expected versus actual electrical responses, defective lines can be flagged for repair or disposal before they compromise the entire sensor array, thus maintaining high reliability while preserving complex device architecture.
Solution Approach 2:
The patent introduces an intermediary testing and identification system between the manufacturing process and final product delivery. This intermediary layer uses test pixel arrays and electrical response comparison to detect defective transmission lines, acting as a mediator that separates the manufacturing defects from the final functional performance, allowing defective individual lines to be identified and isolated without affecting the overall array complexity and functionality.
2Productivity
If defective transmission lines are left unaddressed, then manufacturing yield and productivity are maintained, but image quality degrades and unintended artifacts appear due to floating voltages from environmental noise
Solution Approach 1:
The patent extracts and isolates defective transmission lines from the functional sensor array through identification using test pixel arrays. By detecting which specific transmission lines have opens or shorts and separating them from the healthy lines, the system maintains high manufacturing yield by preserving usable sensor elements while removing only the defective portions, thereby preventing image quality degradation and artifacts caused by floating voltages on defective lines.
Solution Approach 2:
The patent converts the harmful effect of manufacturing defects into a benefit by using the test pixel arrays and electrical response measurement to identify defective lines. What would normally be destructive defects (opens and shorts causing floating voltages and image artifacts) are transformed into useful information for quality control, allowing the system to maintain high productivity by sorting and isolating only the defective elements while preserving the majority of functional sensor array.
3Measurement precision
If comprehensive electrical testing is performed on all transmission lines, then detection precision of opens and shorts is improved, but measurement and testing time increases
Solution Approach 1:
The patent segments the testing process by using separate test pixel arrays for different transmission lines rather than testing the entire sensor array uniformly. Each test pixel array is configured to specifically test particular gate, data, or bias lines, allowing parallel or sequential testing of individual lines. This segmentation enables precise detection of opens and shorts in specific transmission lines while reducing overall testing time compared to exhaustive testing of every pixel and line in the complete array.
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
Effectively addresses the issue of image quality degradation by grounding defective transmission lines, reducing unintended artifacts and enhancing the reliability of image sensor arrays by ensuring stable electrical connections.
Implementation Method 1
performing a laser-weld operation on at least one side of the data line to weld at least a portion of the data line to ground
Implementation Method 2
performing a laser-cut on a readout portion of the data line
Data Source
AI summary
A method for improving the performance of an image sensor array includes performing an electrical test on the image sensor array, generating a test image from the electrical test to detect an open circuit in a data line of the image sensor array, performing a laser-weld operation the data line to weld a portion of the data line to ground, re-testing the image sensor array to confirm a successful laser-weld operation, performing a laser-cut on a readout portion of the data line, and re-testing the image sensor array to confirm a successful laser-cut operation.