Layered Ceramic Edge Seal for Vacuum Insulated Glass Durability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional vacuum insulated glass panels face issues such as significant de-tempering of glass substrates, high manufacturing costs, lack of durability, and hermeticity problems due to thermal stress and cracks, leading to non-compliance with safety codes and increased breakage rates.
Innovation Solution
A vacuum insulating panel design with a multi-layer ceramic edge seal, utilizing a main seal layer and primer layers with controlled thermal expansion coefficients, combined with laser heating to form the edge seal, which maintains compressive and tensile stresses in the glass substrates and reduces transient thermal stress.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If conventional single-layer ceramic seal is used, then manufacturing process is simple, but thermal stress causes cracks and hermeticity problems
Solution Approach 1:
The seal is divided into multiple ceramic layers with different thermal expansion coefficients. The first ceramic layer has a thermal expansion coefficient matching the glass substrate, while the second ceramic layer has different properties, creating a segmented structure that distributes thermal stress and prevents cracking while maintaining hermeticity.
Solution Approach 2:
The seal uses a composite ceramic structure where multiple ceramic materials with different thermal expansion coefficients are combined. This composite approach allows the seal to accommodate thermal expansion differences between the glass substrate and ceramic material, reducing transient thermal stress and preventing delamination or cracking.
2Strength
If high temperature firing is used to form ceramic seal, then seal strength is improved, but glass substrate undergoes significant de-tempering
Solution Approach 1:
The first ceramic layer is designed with a thermal expansion coefficient that closely matches the glass substrate, creating a local quality match at the glass-ceramic interface. This reduces thermal stress concentration at the interface during firing and service, allowing for adequate seal strength without excessive de-tempering of the glass substrate.
Solution Approach 2:
The invention changes the thermal expansion coefficient parameter of the ceramic seal layers to match or accommodate the glass substrate. By selecting ceramic materials with specific thermal expansion coefficients (first layer matching glass, second layer with different properties), the firing temperature can be optimized to form a strong seal while minimizing de-tempering of the glass substrate.
3Ease of manufacture
If ceramic seal with mismatched thermal expansion is used, then seal formation is easier, but transient thermal stress causes delamination and cracks
Solution Approach 1:
The invention explicitly addresses thermal expansion by using a first ceramic layer with a thermal expansion coefficient matched to the glass substrate, and a second ceramic layer with a different thermal expansion coefficient. This layered approach to thermal expansion management allows the seal to form easily while preventing transient thermal stress-induced delamination and cracks during cooling and service.
Solution Approach 2:
The ceramic seal is segmented into multiple layers with different thermal expansion properties. The first ceramic layer handles the interface with the glass substrate with matched thermal expansion, while the second ceramic layer provides additional sealing function with different thermal expansion characteristics, collectively preventing stress concentration and delamination.
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
The solution ensures the panel maintains structural integrity, meets safety standards, and reduces manufacturing costs by minimizing de-tempering and hermeticity issues, while providing efficient thermal insulation.
Implementation Method 1
Providing a vacuum in the space between the substrates reduces conduction and convection heat transport, and thus provides insulating properties
Implementation Method 2
a hermetic seal formed by heating and sintering a ceramic material with the laser beam
Implementation Method 3
heating and sintering a ceramic material with the laser beam
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A vacuum insulating panel may include: a first glass substrate; a second glass substrate; a plurality of spacers provided in a gap between at least the first and second substrates, wherein the gap is at a pressure less than atmospheric pressure; a seal provided between at least the first and second substrates, the seal including a first ceramic seal layer and a second ceramic seal layer, wherein the second ceramic seal layer is located between at least the first ceramic seal layer and the first glass substrate; and wherein one or more of: (i) a thermal (TC) conductivity of the first ceramic seal layer is be less than a thermal conductivity of the first glass substrate, and wherein the thermal conductivity of the first glass substrate is less than a thermal conductivity of the second ceramic seal layer, so that the thermal conductivity of the second ceramic seal layer is greater than the thermal conductivity of the first substrate and greater than the thermal conductivity of the first ceramic seal layer; (ii) a thermal conductivity of the second ceramic seal layer is greater than a thermal conductivity of the first ceramic seal layer; and/or (iii) a ratio TDpl/TDg, where TDpl represents a thermal diffusivity (TD) of the second ceramic seal layer and TDg represents a thermal diffusivity of the first glass substrate, is at least 1.020 and wherein the thermal diffusivity of the second ceramic seal layer is greater than a thermal diffusivity of the first ceramic seal layer.