Laser Welding Lens Device to PCB Frame
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Solution Overview
Problem
The existing methods for forming optical assemblies, which involve active alignment and epoxy curing, are time-consuming and prone to human error, leading to reduced manufacturing throughput and yield due to the potential for optical misalignment during the curing process.
Innovation Solution
The optical assembly is formed by providing a frame on a printed circuit board, mounting opto-electronic elements, and laser-welding a lens device onto the frame, using fiducials for alignment and a laser-welding tool to secure the lens device in place, thereby eliminating the need for manual epoxy application and curing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If active alignment and epoxy curing methods are used to form optical assemblies, then optical alignment can be achieved, but manufacturing throughput is reduced due to time-consuming processes
Solution Approach 1:
The patent replaces the mechanical epoxy application and curing process with a laser welding system. The laser welding apparatus uses a focused laser beam to melt and fuse the lens device directly to the PCB, eliminating the need for manual or automated epoxy dispensing and curing cycles. This substitution of mechanical/chemical bonding with laser-based thermal bonding dramatically reduces process time while maintaining alignment precision.
Solution Approach 2:
The patent implements preliminary alignment of the lens device to the PCB using fiducial markers before the laser welding process. The alignment system positions the lens device with high precision relative to the optical components on the PCB, and this pre-aligned position is maintained throughout the laser welding process. This preliminary positioning action ensures that the final welded assembly maintains optical alignment without requiring time-consuming post-alignment adjustments.
2Ease of manufacture
If manual epoxy application and curing is performed, then lens device can be secured to PCB, but manufacturing yield is reduced due to human error and potential misalignment during curing
Solution Approach 1:
The laser welding system is designed to be self-aligning and self-regulating during the bonding process. The fiducial marker system automatically provides reference points for the alignment algorithm, and the laser welding process inherently maintains the relative positions of components without requiring manual intervention. The system self-corrects for minor positioning variations, eliminating human error associated with manual epoxy application and curing monitoring.
Solution Approach 2:
The patent incorporates a feedback mechanism where the alignment system continuously monitors the position of the lens device relative to the PCB fiducials during the assembly process. This real-time feedback allows the system to make precise adjustments to maintain optimal alignment before and during laser welding, ensuring high manufacturing yield by preventing misalignment defects that would occur with manual processes.
3Strength
If epoxy curing process is used to secure lens device, then bonding can be achieved, but time is lost during the curing period when elements may drift out of alignment
Solution Approach 1:
The patent utilizes the phase transition of the laser beam from optical energy to thermal energy to rapidly melt and fuse the lens device to the PCB. The focused laser beam delivers concentrated thermal energy that quickly melts the bonding interface materials, creating a strong weld bond in seconds rather than requiring hours of epoxy curing. This phase transition approach achieves both strong bonding and rapid processing.
Solution Approach 2:
The laser welding process employs periodic or pulsed laser delivery rather than continuous exposure. The laser beam is delivered in controlled pulses or cycles, allowing for precise heat management and rapid bonding without excessive heat accumulation. This periodic action enables the process to complete bonding quickly while maintaining alignment stability throughout the brief processing window.
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 approach significantly increases manufacturing throughput and yield by automating the alignment and securing process, reducing the likelihood of optical misalignment and improving the efficiency of the assembly process.
Implementation Method 1
laser-welding a lens device onto the frame
Data Source
AI summary
An optical assembly can be formed by providing a frame made of a plastic material on a surface of a printed circuit board (PCB), mounting at least one opto-electronic element on the surface of the PCB within the frame, and laser-welding a lens device onto the frame.