Double-Directional Laser Drilling for Sub-50 μm Precision Holes
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Solution Overview
Problem
Conventional machining methods, such as drilling, are limited in creating small diameter holes and often result in asymmetrical holes with difficulty in achieving precision due to the nature of Gaussian or flat-headed laser beams used in laser processing.
Innovation Solution
A double-directional machining laser machine tool is developed, comprising a focused laser source, lifting, motion, and rotating platforms, along with a vision module and control device, to form symmetrical deep holes by drilling on both surfaces of a workpiece, with optional modification laser and diamond milling cutter for precise trimming.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional drilling is used, then holes with diameter greater than 100 μm can be made, but holes with smaller diameter cannot be made and the drill is easily damaged
Solution Approach 1:
The patent replaces the mechanical drilling system with a laser-based processing system. The laser beam can be focused to extremely small spot sizes, enabling hole diameters below 100 μm without the mechanical constraints and tool damage issues of conventional drills. The laser energy ablates or melts the material to create precise holes.
Solution Approach 2:
The patent changes the processing parameters by using laser beams with controlled intensity distribution and focusing. By adjusting laser power, pulse duration, and focus spot size, precise control over hole diameter and depth is achieved, enabling sub-100 μm holes with high precision.
2Manufacturing precision
If Gaussian or flat-headed laser beams are used for hole processing, then holes can be created, but the holes are wider at the top and narrower at the bottom, making it difficult to control flatness and achieve precision requirements
Solution Approach 1:
The patent intentionally uses an asymmetric top-hat beam intensity distribution (uniform across the beam cross-section) rather than the conventional Gaussian distribution (peaked at center). This symmetric intensity profile across the beam width produces more uniform material removal and results in holes with better cylindrical symmetry and controlled dimensions throughout the depth.
Solution Approach 2:
The patent changes the laser beam intensity distribution parameter from Gaussian to top-hat profile. This parameter change fundamentally alters the material interaction pattern, producing holes with uniform diameter and improved flatness control, meeting precision requirements that were unachievable with Gaussian beams.
3Manufacturing precision
If single-directional laser drilling is used, then holes can be formed, but deep symmetrical holes cannot be achieved
Solution Approach 1:
The patent segments the hole formation process into two separate operations: drilling from the first surface and drilling from the second surface. Each operation creates a partial hole, and the two segments meet in the middle to form the complete deep hole. This segmentation enables symmetrical deep holes with high precision by allowing each pass to work from its own surface toward the center.
Solution Approach 2:
The patent inverts the conventional single-directional approach by performing drilling from both surfaces simultaneously or sequentially. Instead of drilling from one surface to the other, the process drills from the first surface partway, then drills from the second surface to meet the first, creating symmetrical deep holes with precise dimensional control.
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
Enables the creation of deep holes with diameters less than 50 μm and depths less than 500 μm, achieving high precision and symmetry, while allowing for precise inner wall trimming and edge chamfering, overcoming the limitations of conventional machining.
Implementation Method 1
The focused laser source outputs a first laser beam
Implementation Method 2
enable the first laser beam to form a first recessed hole at a predetermined position on a first surface of the workpiece
Data Source
AI summary
A double-directional machining laser machine tool includes a focused laser source, a lifting platform, a motion platform, a rotating platform, a height sensor, a vision module, and a control device. The control device drives, according to a distance detected by the height sensor, the lifting platform to lift the focused laser source up or down, and drives, according to an image, the motion platform to displace the bearing table, so as to enable a first laser beam outputted by the focused laser source forms a first recessed hole at a predetermined position on a first surface of a workpiece. The control device drives the rotating platform to rotate the workpiece, so as to enable the first laser beam forms a second recessed hole on a second surface of the workpiece, and the first recessed hole is in communication with the second recessed hole, so as to form a deep hole.