Hermetic Ferrule Sealing on Dielectric Substrates With Patterned Layers
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Solution Overview
Problem
Existing hermetic assembly techniques face challenges in bonding dielectric and metal materials, requiring smooth surface polishing and high-temperature brazing, which can introduce stress and limit design flexibility and size constraints.
Innovation Solution
A hermetic assembly that includes a ferrule with a flange welded to a patterned layer on a dielectric substrate, allowing for minimal surface preparation and no need for weld rings, enabling thinner housing sidewalls and more space for electronic components, while maintaining a hermetic seal and protecting the substrate from external loads.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If glass insulators are sealed directly to pins and ferrule by heating to high temperatures, then hermetic seal is achieved, but thermal stress and material stress are introduced
Solution Approach 1:
The patent introduces an intermediary patterned metal layer between the ferrule and dielectric substrate. This metal layer serves as a mediator that can be welded to the ferrule at lower temperatures compared to direct glass-to-metal sealing, thereby reducing thermal stress while maintaining hermetic seal integrity. The patterned metal layer acts as a buffer zone that distributes and reduces stress concentration.
Solution Approach 2:
The patent changes the bonding temperature parameter by using laser welding of metal layers at relatively lower temperatures compared to traditional high-temperature glass sealing processes. This parameter change reduces thermal stress on the materials while achieving the hermetic seal function through the patterned metal layer and ferrule welding.
2Reliability
If high-temperature brazing is used to join corrosion-resistant materials, then hermetic seal is achieved, but design flexibility is limited and housing sidewalls must be thicker
Solution Approach 1:
The patent replaces the traditional mechanical brazing process with laser welding of a patterned metal layer. This substitution enables lower temperature processing, thinner housing sidewalls, and greater design flexibility while maintaining hermetic seal integrity. The laser welding process allows for more precise and flexible manufacturing compared to conventional high-temperature brazing.
3Manufacturing precision
If surface polishing is performed on dielectric and metal materials, then bonding quality is improved, but manufacturing complexity and time increase
Solution Approach 1:
The patent uses a patterned metal layer as an intermediary that eliminates the need for extensive surface polishing of the dielectric substrate. The metal layer can be applied to the dielectric surface and then welded to the ferrule, providing bonding quality without requiring the dielectric surface to be highly polished, thereby reducing manufacturing complexity.
4Reliability
If traditional hermetic sealing methods are used, then seal integrity is maintained, but space for electronic components is reduced
Solution Approach 1:
The patent changes the processing temperature parameter to enable lower temperature laser welding instead of high-temperature brazing. This allows for thinner housing sidewalls and reduced material usage, thereby increasing the internal volume available for electronic components while maintaining hermetic seal integrity through the patterned metal layer approach.
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 solution simplifies the attachment process, reduces thermal stress, and provides a reliable hermetic seal for conductive pathways, ensuring the integrity of electrical connections and protecting electronic devices from environmental factors.
Implementation Method 1
a patterned layer connected to the first major surface of the dielectric substrate by a laser bond
Implementation Method 2
The flange is welded to a welding portion of the patterned layer disposed between the flange and the first major surface of the dielectric substrate such that the ferrule is hermetically sealed to the dielectric substrate
Data Source
AI summary
Various embodiments of a hermetic assembly and a method of forming such assembly are disclosed. The hermetic assembly includes a dielectric substrate having a first major surface and a second major surface, a patterned layer connected to the first major surface of the dielectric substrate by a laser bond, and a ferrule having a body and a flange extending from the body. The flange is welded to a welding portion of the patterned layer that is disposed between the flange and the first major surface of the dielectric substrate such that the ferrule is hermetically sealed to the dielectric substrate.