Laser Processing Machine Prism Drive and Control

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Solution Overview

Problem

Existing laser processing machines face challenges in achieving high accuracy in controlling the radiation trajectory of the laser beam due to indirect driving mechanisms and complex trajectory calculations, which limits their ability to perform fine and high-accuracy processing, especially in the context of reducing product size and increasing precision in electronic device manufacturing.

Innovation Solution

The laser processing machine employs a direct motor-driven system with static pneumatic bearings for precise rotation of prisms, a parallel flat plate for zero-point correction, and additional features like astigmatism correction and polarization conversion to enhance beam control, allowing for accurate displacement and deflection of the laser beam without three-dimensional changes, and includes a movable condensing lens and plasma management systems for stable processing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If indirect driving mechanisms (gears, belts) are used to rotate wedge prisms, then the structure is simpler to manufacture, but the synchronous rotation accuracy deteriorates

Engineering Contradiction:
Improveease of manufactureVSAvoidsynchronous rotation accuracy
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent replaces indirect mechanical transmission mechanisms (gears, belts) with direct motor-driven spindles. Each wedge prism is directly coupled to its own spindle, eliminating intermediate transmission components that cause backlash and synchronization errors. This substitution of mechanical transmission with direct drive achieves both high manufacturing precision and acceptable ease of manufacture.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Device complexity

If the radiation angle and radiation position are controlled only by phase difference of wedge prisms, then the control mechanism is simpler, but the trajectory control accuracy deteriorates

Engineering Contradiction:
Improvecontrol mechanism complexityVSAvoidtrajectory control accuracy
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The patent segments the control functions into two independent parts: wedge prisms control radiation angle through phase difference, while parallel flat plates control radiation position through tilt angles. This segmentation allows each component to perform its specific function independently, achieving high trajectory control accuracy without excessive complexity. The decoupled control system avoids the need for complex coupled control algorithms.

Inventive Principle:
Principle #1Segmentation

3Adaptability or versatility

If the laser beam is three-dimensionally deflected by wedge prism rotation, then the trajectory control is more flexible, but the trajectory calculation complexity increases

Engineering Contradiction:
Improvetrajectory control flexibilityVSAvoidtrajectory calculation complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent introduces parallel flat plates as intermediary components between the wedge prisms and the laser beam. The wedge prisms first deflect the beam in one direction, then the parallel flat plates adjust the beam position in another direction through tilting. This intermediary approach simplifies the trajectory calculation by decoupling the deflection control from position control, while maintaining flexible three-dimensional trajectory capability.

Inventive Principle:
Principle #24Intermediary (Mediator)

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

This configuration enables accurate synchronous rotation of prisms, simplifies trajectory control, and improves processing precision by eliminating rotational unevenness and vibration, allowing for finer and more accurate laser processing with stable plasma management and astigmatism correction.

Implementation Method 1

a parallel flat plate for performing zero point correction for the displacement of the laser beam by the first and second wedge prisms, the parallel flat plate being provided in the second spindle so as to be capable of being tilted with respect to an optical axis

Methodology Applied
Scientific EffectRefraction: Refraction

Implementation Method 2

The first prism and the second prism are a pair of prisms that displace the laser beam passing therethrough

Methodology Applied
Scientific EffectRefraction: Refraction

Implementation Method 3

The third prism and the fourth prism are a pair of prisms that deflect the laser beam passing therethrough

Methodology Applied
Scientific EffectRefraction: Refraction

Implementation Method 4

The first spindle, the second spindle, the third spindle, and the fourth spindle may be rotatably held by the first holding means, the second holding means, the third holding means, and the fourth holding means, via static pneumatic bearings, respectively.

Methodology Applied
Scientific EffectAir lubrication: Air Lubrication

Data Source

PatentEP3417985B1Laser processing machine
Publication Date: 2020.06.24 MITSUBISHI HEAVY IND LTD
  • EP3417985B1 patent drawingFigure 1
  • EP3417985B1 patent drawingFigure 2A
  • EP3417985B1 patent drawingFigure 2B

AI summary

Provided is a laser processing machine that processes a workpiece W using a laser beam. The laser processing machine comprises: first to fourth prisms 37, 47, 57, 67 that are disposed in order along an optical path of the laser beam from an upstream side; first to fourth spindles 32, 42, 52, 62 that respectively and independently hold the first to fourth prisms 37, 47, 57, 67; first to fourth holding means 31, 41, 51, 61 that respectively and rotatably hold the first to fourth spindles 32, 42, 52, 62; first to fourth motors 35, 45, 55, 65 that are respectively composed of rotors 35b, 45b, 55b, 65b that are respectively fixed to the first to fourth spindles 32, 42, 52, 62, and stators 35a, 45a, 55a, 65a that are respectively fixed to the first to fourth holding means 31, 41, 51, 61; and prism moving means 101, 102 that move the first prism 37 and/or the second prism 47.