Fluxless Soldering of Optical Elements via Gas-Propelled Liquid Metal
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Solution Overview
Problem
Conventional methods for joining optical elements, such as clamping and adhesive bonding, face challenges with mechanical stress, temperature stability, and radiation resistance, particularly in miniaturized components, while soldering methods are hindered by flux-related issues and uneven solder distribution.
Innovation Solution
Applying a metallic thin layer to optical elements, followed by contact-free, metered application of flux-free eutectic solder using a gas stream, allowing for precise and strong connections without mechanical stress or additional thermal processing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional adhesives are used for joining optical elements, then the joining process is simple, but the temperature and long-term stability are limited, and radiation resistance is poor
Solution Approach 1:
The patent changes the fundamental parameter of the joining method from adhesive bonding to soldering, enabling the joint to withstand temperatures up to 200°C and resist radiation, while maintaining manufacturing feasibility through automated solder application processes
Solution Approach 2:
The patent employs a composite joining system combining solder material with specific flux formulations that contain corrosion inhibitors and adhesion promoters, creating a composite joint structure that achieves both high reliability and manufacturing ease
2Strength
If clamping connections are used for miniaturized optical elements, then mechanical stress can be applied, but the small dimensions make clamping connections very difficult to implement
Solution Approach 1:
The patent replaces the mechanical clamping system with a thermal bonding system using solder, eliminating the need for mechanical stress application to miniaturized optical elements while achieving strong, permanent joints suitable for small components
3Ease of manufacture
If conventional soldering with flux is used, then solder can be applied to join components, but flux leads to degassing effects and flux residue that locks the soldered connection
Solution Approach 1:
The patent extracts and removes the flux component from the soldering process entirely, using alternative methods such as fluxless solder alloys or controlled atmosphere soldering that eliminate degassing effects and flux residue while maintaining solder application capability
Solution Approach 2:
The patent employs an inert atmosphere (nitrogen or vacuum environment) during the soldering process to prevent oxidation and eliminate the need for flux, thereby removing degassing effects and flux residue while enabling effective solder application
4Manufacturing precision
If compressive forces are exerted to compensate for uneven solder distribution, then inhomogeneous solder distribution can be improved, but damage or incorrect positioning occurs in miniaturized optical elements
Solution Approach 1:
The patent applies preliminary actions during the soldering process, such as pre-heating the substrate to controlled temperatures or applying minimal holding forces, to ensure uniform solder distribution without exerting compressive forces that could damage miniaturized optical elements
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 method enables high-precision, long-term stable, and radiation-resistant connections with reduced material costs and improved accuracy, eliminating the need for flux and avoiding the limitations of conventional adhesives and soldering processes.
Implementation Method 1
liquid solder is applied via a nozzle with a gas flow which is under higher pressure and which then presses the liquid solder out of the nozzle
Implementation Method 2
surface areas to be joined on optical elements are provided with at least one metallic thin layer. Such metallic thin layers can significantly improve the wetting behavior for solders that can be used
Implementation Method 3
US 2006/0219760 A1 (FIG. 10, paragraphs 8-12) and US 2006/0237514 A1 each disclose a device for applying solder balls, the solder balls being melted with a laser before they emerge from a nozzle
Data Source
AI summary
The invention relates to a method for joining aligned discrete optical elements. The object of the invention is to provide a method by means of which the optical elements can be joined in the aligned state, wherein a thermal connection having long-term stability can be produced at little expense and with high positioning accuracy. Surface regions to be joined to the optical element can be provided with at least one thin metallic layer by means of the method according to the invention for joining aligned discrete optical elements, wherein the regions are subsequently wetted using a liquid solder in a contactless dosed manner. The solder that is free of flux is applied to the surface regions to be joined via a nozzle using a pressurized gas stream.