Optical Fiber Laser Welding to Substrates
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High coefficient of thermal expansion (CTE) adhesives used to secure optical fibers to substrates cause misalignment during elevated temperature processes, such as solder reflow, due to thermal expansion, disrupting optical communication.
Innovation Solution
A laser welding process where optical fibers act as a cylindrical lens to focus a laser beam onto a substrate, melting and diffusing the substrate material into the optical fiber, eliminating the need for high CTE adhesives and ensuring secure bonding without thermal displacement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If adhesive is used to secure optical fibers to substrate, then optical fibers are fixed to substrate, but optical fibers become misaligned during elevated temperature processes due to thermal expansion
Solution Approach 1:
The patent removes the adhesive layer from the bonding system entirely. Instead of using adhesive to bond optical fibers to the substrate, the invention directly bonds the optical fiber to the substrate through laser welding, eliminating the source of thermal expansion mismatch that causes alignment errors during solder reflow processes
Solution Approach 2:
The patent replaces the mechanical/adhesive bonding system with a direct laser welding bonding system. The adhesive is replaced by a laser-induced bonding mechanism that creates a strong, thermally stable bond between the optical fiber and substrate without requiring high-CTE materials
2Strength
If high CTE adhesive is used to bond optical fibers, then strong bonding is achieved, but position of optical fibers shifts during solder reflow process
Solution Approach 1:
The adhesive layer is completely removed from the bonding system. The patent achieves strong bonding through direct laser welding of the optical fiber to the substrate, eliminating the high-CTE adhesive that causes position shifts during thermal processes
Solution Approach 2:
The patent changes the bonding mechanism from adhesive-based to laser welding-based. This parameter change transforms the bonding process into one that creates a thermally stable connection without the position shift problems associated with high-CTE adhesives during solder reflow
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 provides a robust and thermally stable attachment of optical fibers to substrates, maintaining alignment and enabling effective optical communication even under elevated temperatures, with strong bonding and minimal displacement.
Implementation Method 1
the optical fiber acts as a cylindrical lens to focus the laser beam into the substrate
Implementation Method 2
The focused laser beam melts the substrate material
Implementation Method 3
The focused laser beam melts the substrate material
Implementation Method 4
which also causes the melted substrate material to diffuse into the material of the optical fiber
Data Source
Figure 2
Figure 3
Figure 4
AI summary
Assemblies, optical connectors, and methods for bonding optical fibers (110) to a substrate (100) using a laser beam (120) are disclosed. In one embodiment, a method of bonding an optical fiber (110) to a substrate (100) includes directing a laser beam (120) into the optical fiber (110) disposed on a surface (102) of the substrate (100), wherein the optical fiber (110) has a curved surface (111) and the curved surface (111) of the optical fiber focuses the laser beam (120) to a diameter that is smaller than a diameter of the laser beam as it enters the optical fiber. The method further includes melting, using the laser beam (120), a material of the substrate (110) at a bond area (112) between the optical fiber (110) and the surface (102) of the substrate (100) such that the optical fiber (110) is bonded to the surface (102) of the substrate (100).