Laser Processing Device Failure Recognition via Photodetector Feedback
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Solution Overview
Problem
Conventional laser processing devices face issues with inconsistent pulsed laser beam irradiation, leading to incomplete via hole formation, improper removal of low-dielectric insulating films, and discontinuous division grooves due to non-uniform energy distribution and intermittent irradiation, resulting in processing failures and wafer damage.
Innovation Solution
A laser processing device equipped with a controller that monitors and adjusts pulsed laser beam irradiation by detecting pulse signals and energy levels, ensuring proper timing and energy delivery through a photodetector system, and stores coordinate values for reprocessing, allowing for real-time failure recognition and minimization of damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If pulsed laser beam irradiation is used for via hole formation and Low-k film removal, then productivity is improved compared to drill processing, but manufacturing precision deteriorates due to non-uniform energy distribution and intermittent irradiation
Solution Approach 1:
The patent employs feedback mechanisms by monitoring the actual laser beam output timing and energy with detectors, comparing it against the intended pulse signals, and adjusting the irradiation process accordingly to ensure complete via hole formation and proper Low-k film removal while maintaining high productivity
Solution Approach 2:
The patent optimizes laser processing parameters including pulse width, pulse interval, and energy distribution to achieve both high productivity and manufacturing precision. By carefully controlling these parameters, the system ensures sufficient irradiation energy is delivered while maintaining fast processing speeds
2Device complexity
If pulsed laser beam irradiation timing is not precisely controlled, then device complexity is reduced, but reliability deteriorates due to incomplete via hole formation and improper Low-k film removal
Solution Approach 1:
The patent uses feedback control by detecting the actual laser output timing with a detector and comparing it to the intended pulse signal timing. When timing deviations are detected, the system adjusts subsequent irradiation pulses to compensate, ensuring reliable via hole formation and Low-k film removal without requiring complex real-time control systems
Solution Approach 2:
The patent implements preliminary timing adjustment by predicting potential timing deviations based on detected pulse signal characteristics and pre-adjusting the irradiation timing before processing continues. This prevents processing errors before they occur, maintaining reliability without adding complex real-time control mechanisms
3Measurement precision
If conventional sacrificial wafer checking is used to recognize laser processing failure, then measurement precision is improved for failure detection, but loss of substance increases due to wafer sacrifice
Solution Approach 1:
The patent performs preliminary detection of laser beam output timing and energy using detectors during the irradiation process itself, before the processing is complete. This allows failure recognition without needing to sacrifice the processed wafer, eliminating material loss while maintaining detection accuracy
Solution Approach 2:
The system uses self-diagnosis by monitoring its own laser output characteristics during processing. The detectors continuously check the actual laser beam parameters against expected values, allowing the system to self-identify processing failures without external inspection or sacrificial wafers
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
The device effectively recognizes and addresses failures in pulsed laser beam irradiation, ensuring accurate via hole formation and film removal, reducing wafer damage by stopping processing when fatal failures occur and facilitating reprocessing at specific coordinates.
Implementation Method 1
a pulsed laser beam detector for detecting the pulsed laser beam by branching a part of the pulsed laser beam oscillated by the laser oscillator to be received by a photodetector
Data Source
AI summary
A laser processing device capable of recognizing a failure of pulsed laser beam irradiation during a process of pulsed laser beam irradiation and taking appropriate measures. A first judgment section and a second judgment section monitor respectively whether a pulsed laser beam is actually irradiated by an oscillation of a laser oscillator at the timing when a pulse signal is output from a pulse signal output section and whether the pulse signal output section outputs the pulse signal as setting to the laser oscillator at the timing when the pulse signal is output based on the preset pulse number. When there is a failure of the pulsed laser beam irradiation during the processing, the occurrence of failure is recognized and it can be recognized whether the failure is caused by a laser beam irradiating unit or a controller including the pulse signal output section.