Hermetic Vacuum Joint Sealing With Low-Temperature Laser Welding
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Solution Overview
Problem
Existing methods for forming hermetically sealed cavities in optical or electrical articles often involve high temperatures and materials that can release harmful substances, leading to potential damage to sensitive components and reduced operating reliability.
Innovation Solution
A method involving laser welding of glass, silicon, or ceramic pieces in a controlled pressure environment, where the pieces are initially positioned in a vacuum chamber, allowing for a preliminary joint formation followed by laser welding outside the chamber, maintaining low temperatures to minimize material degradation and internal stress.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional oven heating is used to melt filler material for hermetic sealing, then the sealing reliability is improved, but the temperature increases causing damage to sensitive components
Solution Approach 1:
The patent replaces thermal welding (oven heating) with laser welding. Instead of using high temperature to melt filler material, a laser beam is used to directly weld the sealing surfaces of the first and second pieces together, achieving hermetic sealing without subjecting sensitive components to high temperatures
Solution Approach 2:
The patent changes the welding parameters by using laser welding instead of thermal welding. The laser welding process allows for precise control of energy input, enabling welding at lower overall temperatures compared to traditional oven heating methods, thus protecting temperature-sensitive components
2Strength
If high temperature processing is used to form hermetic joints, then the sealing strength is improved, but harmful substances are released causing component damage
Solution Approach 1:
The patent replaces thermal welding with laser welding, eliminating the high temperature processing that causes outgassing of harmful substances. The laser welding process generates minimal heat and does not require melting filler material, thus preventing release of harmful gases that could damage sensitive components
Solution Approach 2:
The patent performs laser welding in a vacuum chamber, creating an inert environment that prevents oxidation and contamination during the welding process. This vacuum environment also captures and removes any harmful substances that may be released, preventing them from reaching and damaging the sensitive components
3Manufacturing precision
If vacuum chamber is used during laser welding, then the hermetic sealing quality is improved, but the device complexity increases
Solution Approach 1:
The patent performs preliminary positioning and alignment of the first and second pieces inside the vacuum chamber before closing the chamber for welding. This preliminary action ensures that the pieces are correctly positioned, eliminating the need for complex positioning mechanisms during the welding process itself and reducing overall system complexity
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 enables hermetic sealing without high temperatures, reducing the risk of component damage and enhancing operating reliability by minimizing outgassing and internal stress, while allowing for efficient production of hermetically sealed articles.
Implementation Method 1
forming a welded seam by focusing a laser beam to the interface between the first and the second pieces
Implementation Method 2
changing the internal pressure of the chamber so as to cause a flow of a gas from the open cavity through the gap
Data Source
Figure 1a~1b
Figure 1c~1d
Figure 1e~1f
AI summary
An article (100) is produced by welding a first piece (110) to a second piece (120) by a laser beam (LB1). The method comprises: - providing the first piece (110), which comprises an open cavity (OCA1) and a first sealing surface (SRF1), - providing the second piece (120), which comprises a second sealing surface (SRF2), - providing a chamber (200), which has controllable internal pressure (p2), - closing the chamber (200) such that the first piece (110) and the second piece (120) are inside the closed chamber (200), - changing the internal pressure (p2) of the chamber (200) so as to cause a flow (F1) of a gas (GAS1) from the open cavity (OCA1), - closing the open cavity (OCA1) by moving at least one of the pieces (110, 120) such that the first sealing surface (SRF1) forms a partially gas tight preliminary joint (S0) together with the second sealing surface (SRF2), and such that the first piece (110) and the second piece (120) define an interface (IF1), - opening the chamber (200) after the preliminary joint (S0) has been formed, and - forming a welded seam (J1) by focusing a laser beam (B1) to the interface (IF1) after the chamber (200) has been opened, wherein the first sealing surface (SRF1) and the second sealing surface (SRF2) are substantially planar.