Active Solder Joining of Micro-Optics Without Metallic Coatings
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for joining optical components to a carrier structure using electromagnetic radiation require metallic coatings for wettability, leading to contamination and increased costs, and struggle with achieving reliable connections, especially when thermal conductivities of components differ.
Innovation Solution
A method utilizing active solders, such as rare-earth doped universal solders, that achieve sufficient wetting without flux or coatings, using electromagnetic radiation to melt and solidify the solder between components, allowing for a robust and outgassing-free connection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If metallic coatings are applied to surfaces to be joined to ensure sufficient wettability, then the solder joint reliability is improved, but the risk of contamination and damage to optical components increases
Solution Approach 1:
The patent extracts and eliminates the metallic coating layer from the joining process. By using fluxless active solders with specific compositional ranges (e.g., Sn-Ag-Cu-In alloys with controlled oxide content), the invention achieves sufficient wettability directly on the metal substrate without requiring intermediate metallic coatings, thereby removing the source of contamination while maintaining joint reliability
Solution Approach 2:
The invention changes the chemical composition parameters of the solder material by incorporating specific elements (In, Ga, Zn) in controlled amounts alongside traditional soldering elements (Sn, Ag, Cu). This compositional modification enables the solder to achieve adequate wettability and form reliable joints on metal surfaces without flux or metallic coatings, thus resolving the contradiction between reliability and contamination risk
2Reliability
If metallic coatings are applied to create wettability for fluxless solders, then the joining process becomes more reliable, but the process complexity and costs increase
Solution Approach 1:
The patent removes the metallic coating step from the joining process sequence. By formulating active solders with specific compositional ranges that provide inherent wettability on metal surfaces, the invention eliminates the need for complex coating deposition processes, surface preparation steps, and quality control measures associated with coatings, thereby simplifying the overall process while maintaining reliability
Solution Approach 2:
The active solder material is designed to be self-sufficient by incorporating elements that provide both wettability and oxidation resistance within its composition. This self-service capability eliminates the need for external coatings or flux materials, reducing process complexity while ensuring reliable joining performance
3Manufacturing precision
If low and precisely adjustable electromagnetic radiation power is used to achieve soldering temperature at the coating surface, then the solder joint quality is improved, but the process adaptability to different material properties decreases
Solution Approach 1:
The invention changes the solder material parameters by incorporating elements with different thermal and melting characteristics (In, Ga, Zn combined with Sn, Ag, Cu). This creates a compositional buffer that broadens the processing window, allowing the solder to achieve adequate melting and wetting across a wider range of electromagnetic radiation powers and heating rates, thereby improving process adaptability while maintaining joint quality
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 a high-strength, flux-free soldered connection that is cost-effective and adaptable, suitable for precise and repeatable adjustments, particularly in harsh environments, without the need for metallic coatings, thus reducing contamination risks and process complexity.
Implementation Method 1
The electromagnetic radiation is directed onto the active solder through one of the components to be joined, which is at least partially transparent to electromagnetic radiation. The solder is melted using electromagnetic radiation, preferably laser radiation
Implementation Method 2
an active solder, which achieves sufficient wetting of the surfaces to be joined without the need for flux
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
The present invention relates to a method for joining components (2), in particular micro-optical components, on a support structure (1) using electromagnetic radiation (4). In the method, a solder (3) is applied to at least one of in each case two surface areas that are to be connected of the components (1, 2) to be joined or introduced between in each case two surface areas that are to be connected of the components (1, 2) to be joined. The surface areas that are to be connected are then positively connected to one another by melting the solder (3) with the aid of electromagnetic radiation (4) and subsequent cooling. In the method, an active solder (3) is used as a solder, which, in the absence of a flow means, achieves a wetting of the surface areas that are to be connected, which is sufficient for producing the solder connection. The electromagnetic radiation (4) is directed through one of the components to be joined (1), which is at least partially permeable to the electromagnetic radiation (4), onto the active solder (3). By using the proposed method, in particular optical components (2) can be connected with a support structure (1) in a simple manner without the use of expensive additional coatings.