Die Supply Device Fiducial Alignment Correction
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Solution Overview
Problem
The uneven expansion of a dicing sheet causes misalignment of dies, leading to incorrect estimation and imaging of defective or missing dies during the die supply process, resulting in improper adsorption order and potential mismatches in die quality correspondence with wafer map data.
Innovation Solution
A die supply apparatus with a push-up mechanism, camera, image processing, and fiducial dies to accurately determine and correct the adsorption order of dies by reestimating the position of the next die based on the relative positional relationship with fiducial dies when the interval exceeds a predetermined value, ensuring proper alignment and quality correspondence.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the dicing sheet is expanded to supply dies, then the die can be easily picked up, but the position of each die varies due to stretching, causing misalignment
Solution Approach 1:
The patent applies preliminary action by pre-establishing a correspondence relationship between wafer map data (indicating die quality at each position) and the expanded dicing sheet positions before the die picking process. This allows the system to compensate for position variations caused by sheet expansion, ensuring that the correct non-defective dies are selected and picked in the proper order despite the misalignment introduced by expansion.
2Reliability
If the camera images every die to check for bad marks, then quality inspection is thorough, but productivity decreases
Solution Approach 1:
The patent extracts only the necessary quality information from the wafer map data (indicating which dies are non-defective) and uses this extracted information to guide the die picking process. Instead of imaging and inspecting every die individually, the system retrieves pre-stored quality data and applies it to select and pick only the required non-defective dies in order, thereby maintaining quality assurance while significantly improving productivity.
3Measurement precision
If the interval to the next adsorption die is lengthened due to misalignment, then the estimated position may be incorrect, but correcting position requires additional imaging operations
Solution Approach 1:
The patent implements feedback by continuously monitoring the interval between the current die position and the estimated next die position. When the interval exceeds a predetermined threshold (indicating misalignment), the system triggers a corrective action by imaging the fiducial die to re-establish accurate position correspondence. This feedback mechanism ensures position accuracy is maintained while minimizing unnecessary imaging operations, thus balancing precision with time efficiency.
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
Ensures non-defective dies are adsorbed in the correct order, preventing mistaken identification of defective or missing dies, even with misaligned die arrangements due to uneven expansion, thereby improving productivity and accuracy.
Implementation Method 1
When a suction nozzle is lowered and a die on the dicing sheet is adsorbed so as to be picked up
Implementation Method 2
an attachment portion of the target adsorption die on the dicing sheet is pushed up with the push-up pin, and while the attachment portion of the die is partially peeled off from the dicing sheet
Data Source
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AI summary
When a plurality of image-recognizable fiducial dies 45 are disposed at predetermined intervals in an arrangement of dies 31 on a dicing sheet 34, and an interval from a position of a die 31(a) which is subjected to a present adsorption operation to an estimated position for a next adsorption die 31(b) is equal to or greater than a predetermined value, in addition to recognizing the position for the next adsorption die 31(b), a fiducial die 45 adjacent to the next adsorption die 31(b) is selected from the plurality of fiducial dies 45, the fiducial die 45 is imaged by a camera 42, a position of the fiducial die 45 is recognized, and it is determined whether or not a recognition position for the next adsorption die 31 (b) is a proper position for a next adsorption die 31 (c) based on a positional relationship between a recognition position of the fiducial die 45 and the recognition position for the next adsorption die 31(b). When it is determined that the recognition position for the next adsorption die 31 (b) is not the proper position for the next adsorption die 31(c), the position of the die 31(c) to be adsorbed next is reestimated based on the recognition position of the fiducial die 45, the die 31(c) is imaged by the camera 42, the position of the die 31(c) is recognized, and push-up operation and adsorption operation are executed.