Laser Processing Apparatus Liquid Layer Debris Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing laser processing technologies face issues with debris scattering and adhesion during ablation, leading to reduced processing quality and productivity, and previous solutions like using liquid resin or water immersion introduce additional steps or inefficiencies.
Innovation Solution
A laser processing apparatus with a liquid supply mechanism that forms a layer of liquid on the workpiece, using a transparent plate and jet nozzle to prevent debris adhesion and bubble obstruction, allowing for uninterrupted laser beam application and efficient debris removal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If liquid resin is applied to the front surface of the wafer before laser processing, then debris adhesion is prevented and processing quality is secured, but additional steps of applying and removing liquid resin are required, reducing productivity
Solution Approach 1:
A transparent plate is introduced as an intermediary between the laser beam and the workpiece. The plate is positioned such that the laser beam passes through it to reach the workpiece, while the plate itself prevents debris from adhering to the workpiece surface. This mediator approach eliminates the need for liquid resin coating while maintaining debris prevention functionality.
Solution Approach 2:
The harmful function of liquid resin (needing application and removal steps) is extracted and replaced by a solid transparent plate that provides the same protective function without requiring additional processing steps. The plate can be easily removed or replaced after processing, eliminating the time-consuming resin application and removal operations.
2Manufacturing precision
If a wafer is immersed in water during laser processing, then debris adhesion is prevented, but minute bubbles are generated that obstruct laser beam propagation
Solution Approach 1:
The transparent plate serves as a mediator that separates the workpiece from direct contact with water, eliminating bubble generation issues. The plate allows laser beam transmission while preventing water from interacting with the workpiece surface during processing, thus avoiding the harmful effect of bubbles obstructing the laser beam.
Solution Approach 2:
Instead of using water that requires careful management and can generate harmful bubbles, a disposable or easily replaceable transparent plate is used. The plate provides the necessary protection without the side effects of water immersion, and can be discarded or replaced if contaminated, simplifying the overall process.
3Productivity
If laser ablation is performed on the front surface of the wafer, then division grooves are formed, but debris is generated that scatters and adheres to device surfaces, lowering quality
Solution Approach 1:
The transparent plate, which might seem like an additional component, actually converts the harmful debris generation issue into a manageable situation. The plate captures and contains the debris generated during laser ablation, preventing it from scattering and adhering to the device surfaces, while allowing the laser processing to proceed efficiently.
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 apparatus prevents debris adhesion and bubble obstruction, maintaining processing quality without the need for liquid resin coating or water immersion, enhancing productivity and economic efficiency.
Implementation Method 1
a transparent plate disposed such as to make contact with the layer of the liquid
Implementation Method 2
a jet nozzle adapted to jet the liquid toward an application position of the laser beam applied to the workpiece through the transparent plate
Implementation Method 3
a laser beam of such a wavelength as to be absorbed in a workpiece is applied to the workpiece, with a focal point of the laser beam positioned on a surface of the workpiece, whereby grooves serving as starting points of division are formed by ablation
Implementation Method 4
a laser beam of such a wavelength as to be transmitted through a workpiece is applied to the workpiece, with a focal point of the laser beam positioned in the inside of the workpiece
Data Source
AI summary
A laser processing apparatus has a liquid supply mechanism disposed at an upper portion of a holding unit. The liquid supply mechanism includes: a pool adapted to form a layer of a liquid on an upper surface of a workpiece held by a holding table; a transparent plate disposed such as to make contact with the layer of the liquid; a jet nozzle adapted to jet the liquid by positioning a jet port between an upper surface of the workpiece and the transparent plate toward an application position of a laser beam applied to the workpiece through the transparent plate; a liquid supply nozzle adapted to supply the liquid from one side of the pool; and a liquid discharge nozzle adapted to discharge the liquid from the other side of the pool.