Oblique Laser Substrate Structuring for Negative Conicity Patterns
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Solution Overview
Problem
Existing methods for structuring substrates to enhance mechanical adhesion with second materials are limited by the inability to create effective negative conicity patterns, which are crucial for promoting mechanical anchoring and improving mechanical properties such as tension, tearing, and peeling resistance.
Innovation Solution
A method involving a device with a light source, optical system, focusing means, and movement device to generate a focused outgoing light beam with a controlled angle of attack greater than 1°, allowing for the creation of patterns with negative conicity on the substrate surface, enabling better mechanical anchoring and adhesion with second materials.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If conventional laser structuring methods are used with normal incidence beams, then the substrate surface can be modified, but negative conicity patterns cannot be created, limiting mechanical anchoring effectiveness
Solution Approach 1:
The patent applies asymmetry by using an oblique incident light beam instead of a normal incidence beam. The beam strikes the substrate at an angle θ relative to the surface normal, creating asymmetric energy distribution during material ablation. This asymmetric irradiation geometry enables the formation of negative conicity patterns (overhanging structures) that provide effective mechanical anchoring for the second material, resolving the contradiction between achieving strong adhesion and controlling pattern geometry.
Solution Approach 2:
The patent changes the parameter of light beam incidence angle from the conventional normal incidence (0°) to an oblique angle θ. This parameter change fundamentally alters the ablation mechanism and resulting pattern geometry. By controlling the incidence angle parameter, the system can create negative conicity patterns with specific overhang structures that enhance mechanical anchoring, thereby improving mechanical adhesion strength while maintaining precise pattern control.
2Area of stationary object
If the contact area between substrate and second material is increased, then more interatomic bonds can form, but without negative conicity patterns, mechanical anchoring remains insufficient
Solution Approach 1:
The asymmetric oblique beam incidence creates negative conicity patterns with overhanging walls that extend into the second material. This asymmetric geometry provides mechanical interlocking beyond simple surface contact, allowing the second material to anchor into the substrate structures. The overhanging walls created by oblique irradiation enable the second material to wrap around and mechanically lock into the patterns, significantly enhancing mechanical anchoring while maintaining effective contact area.
3Device complexity
If a light beam with normal incidence is used, then the setup is simple, but the resulting patterns lack the negative conicity needed for effective mechanical anchoring
Solution Approach 1:
The patent modifies the incidence angle parameter of the light beam from normal (0°) to oblique (θ > 0°). This single parameter change transforms the pattern formation mechanism to produce negative conicity structures. The modification requires minimal additional optical components (such as adjusting the beam delivery angle or using a galvo scanner), maintaining relatively simple device complexity while dramatically improving mechanical adhesion through the creation of anchorable patterns.
4Strength
If the light beam angle of attack is increased to create negative conicity patterns, then mechanical anchoring improves, but control over groove dimensions becomes more challenging
Solution Approach 1:
The patent employs feedback control through a control unit that monitors and adjusts the oblique beam incidence parameters. The control unit receives information about the desired pattern geometry and adjusts the beam angle θ and other parameters in real-time to compensate for variations in material properties, beam energy distribution, and processing conditions. This feedback mechanism enables precise control over groove dimensions (width, depth, overhang angle) even when using oblique incidence to create negative conicity patterns, resolving the contradiction between mechanical anchoring improvement and dimension 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
The method effectively produces substrates with enhanced mechanical properties by creating patterns that improve adhesion and resistance to traction, shear, and peeling, allowing for larger surface structuring with precise control over groove dimensions and angles.
Implementation Method 1
a light source for generating an incoming structuring light beam (1) capable of machining the upper surface (16) of the substrate (11)
Implementation Method 2
an optical system for obtaining, from said incoming light beam (1), an outgoing light beam (7) spatially offset with respect to said incoming light beam (1), said optical system being capable of modifying the spatial offset between said incoming light beam (1) and said outgoing light beam (7)
Implementation Method 3
focusing means for focusing said outgoing light beam (7)
Data Source
Figure 1
Figure 2
Figure 3a~3c
AI summary
The present application relates to a method for structuring a substrate (11) and comprising the following steps: providing a device (2) comprising a light source (21), an optical system (3) for obtaining an outgoing light beam (7) spatially offset relative to the incoming light beam (8), and suitable for modifying this spatial offset, focusing means (9) for focusing the outgoing light beam (7), a substrate holder, a movement device (60) for generating movement between the outgoing light beam (7) and the substrate (11), providing and placing the substrate (11) on the substrate holder, etching the substrate (11) with the focused outgoing light beam (7) having an angle of attack (107) greater than 1° for any spatial offset between outgoing light beam (7) and incoming light beam (1) imposed by the optical system (3).