Probe Mark Image Comparison for Pad Contact Deviation Correction
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Solution Overview
Problem
Existing probing techniques face challenges in accurately determining contact position deviations of a probe with respect to a pad on a substrate, especially when multiple probe marks are present, as they require detection of probe marks on dummy substrates or spot light positions, leading to prolonged probing times and difficulty in distinguishing between overlapping marks.
Innovation Solution
A probing apparatus that captures images before and after probe contact, uses image processing to identify the latest probe mark position among multiple marks, and calculates positional deviations for correction, employing incremental region acquisition and complementing methods to enhance precision even when marks overlap.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If probe marks are detected on dummy substrates or spot light positions are detected to correct contact position, then contact position correction can be achieved, but probing time is prolonged
Solution Approach 1:
The patent performs preliminary actions by capturing an image of the pad region before probe contact (first image) and after probe contact (second image). By preparing these images in advance and comparing them to identify the latest probe mark position, the system achieves accurate contact position correction without requiring additional time-consuming operations during the actual probing process.
Solution Approach 2:
The patent uses image copying and comparison techniques. It captures images of the pad region at different time points (before and after contact) and compares these copied images to identify the latest probe mark position. This approach replaces the need for complex real-time detection during probing, thereby reducing probing time while maintaining correction accuracy.
2Productivity
If multiple probe marks are present on a pad, then probing can be conducted multiple times, but it becomes difficult to detect deviation when marks overlap
Solution Approach 1:
The patent performs preliminary image capture before probe contact to establish a reference state. By comparing this preliminary image with post-contact images, the system can identify which probe mark is the latest even when multiple marks are present or overlapping. This preliminary action enables accurate deviation detection while supporting multiple probing operations.
Solution Approach 2:
The patent implements a feedback mechanism by continuously capturing images after each probe contact and comparing them with previous images to identify the latest probe mark position. This feedback loop allows the system to track contact position deviations accurately across multiple probing operations, even when probe marks overlap, thereby maintaining measurement precision while enabling high productivity.
3Measurement precision
If probe contact position is corrected based on detected probe marks, then alignment accuracy is improved, but the process becomes complex when multiple marks exist
Solution Approach 1:
The patent simplifies the image processing complexity by performing preliminary image capture before probe contact. This preliminary image serves as a reference that, when compared with post-contact images, automatically identifies the latest probe mark position. This approach maintains high alignment accuracy while avoiding the complexity of analyzing multiple overlapping marks from scratch.
Solution Approach 2:
The patent uses a simple and effective copying approach by capturing images at different time points (before and after contact) and comparing them. This method avoids complex image processing algorithms needed to distinguish multiple overlapping marks, thereby reducing device complexity while maintaining alignment accuracy through straightforward image comparison.
Data Source
AI summary
In a prober, a post-contact image representing a region including a pad is acquired by capturing an image of a substrate after a probe has been brought into contact with the pad having an existing probe mark. An image storage unit stores in advance a pre-contact image representing the pad-inclusive region before the probe is brought into contact with the pad. A latest probe mark position acquiring unit acquires a position of a latest probe mark region created by the contact of the probe with the pad from among a plurality of probe mark regions in the post-contact image respectively corresponding to a plurality of probe marks on the pad by comparing the post-contact image with the pre-contact image. A positional deviation acquiring unit finds a deviation in a contact position of the probe with respect to the pad, based on the position of the latest probe mark region.