Quartz Glass Heat Reflector With Buffer Layer for Crack-Resistant Sealing
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Solution Overview
Problem
Existing heat reflective materials for high-temperature environments, such as those used in electric furnaces and semiconductor industry heat treatment furnaces, face challenges including breakage under high temperatures, dust generation, and difficulty in cleaning with chemical liquids. Additionally, these materials often have high heat capacity and absorption, which slows down temperature control responsiveness.
Innovation Solution
A heat reflective member with a laminated structure comprising quartz glass layers on both surfaces of a siliceous sintered powder layer, including an impermeable layer and a buffer layer. The impermeable layer prevents gas or liquid penetration, while the buffer layer helps distribute stress and prevent breakage. This structure is manufactured using a method that involves producing an intermediate glass laminate and then cutting it into shape using a laser, forming the impermeable and buffer layers simultaneously.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a reflective layer is formed by fusing silica particles to each other, then a transparent silica layer is obtained, but reflection performance is reduced and cracks or breakage occur due to volume change and thermal expansion differences
Solution Approach 1:
The patent applies preliminary action by pre-forming the grain aggregate layer with proper particle arrangement and bonding before applying the transparent silica layer. This preliminary structure preparation ensures that subsequent heating and fusion processes proceed uniformly, preventing cracks and breakage while maintaining reflection performance.
Solution Approach 2:
The patent employs parameter changes by carefully controlling heating temperature, heating rate, and holding time during the formation of the transparent silica layer. By optimizing these parameters, the fusion process achieves complete bonding without excessive volume change or thermal stress, preventing cracks while maintaining high reflection performance.
2Use of energy by moving object
If metal reflective materials like gold are used, then high reflection performance is achieved, but metal impurities are introduced which are unfavorable for semiconductor industry applications
Solution Approach 1:
The patent changes the material parameter from metal to silica-based grain aggregates, maintaining high reflection performance through controlled particle fusion and aggregation while completely eliminating metal impurity contamination, making it suitable for semiconductor industry applications.
Solution Approach 2:
The patent uses composite materials by combining siliceous sintered powder with binder materials to create a grain aggregate layer that provides high reflection performance without metal impurities. The composite structure achieves both optical performance and chemical purity requirements.
3Use of energy by moving object
If silica particles are partially fused to form a grain aggregate structure, then high reflection performance is obtained, but the structure becomes porous and susceptible to dissolution, peeling, and contamination
Solution Approach 1:
The patent applies local quality by creating different density regions within the grain aggregate layer. The inner region maintains porous structure for high reflection performance, while the outer region forms a denser protective layer that prevents dissolution, peeling, and contamination, achieving both optical performance and structural stability.
Solution Approach 2:
The patent uses composite materials combining partially fused silica particles with binder materials to create a grain aggregate structure. The composite nature provides both the porous structure needed for reflection and the structural integrity needed to prevent dissolution and peeling.
4Temperature
If heat insulating material with high heat absorption is used, then heat retention and thermal uniformity are improved, but temperature control responsiveness is slowed down
Solution Approach 1:
The patent uses composite materials combining heat-reflecting grain aggregate layer with heat insulating material. This composite structure reflects heat to maintain temperature while reducing heat absorption, thereby improving temperature control responsiveness without sacrificing thermal uniformity.
Solution Approach 2:
The patent converts the harmful effect of heat absorption into a beneficial effect by using heat reflection instead. The grain aggregate layer reflects heat rays back into the furnace, maintaining temperature uniformity while avoiding the heat capacity penalty associated with heat-absorbing materials, thus improving responsiveness.
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 heat reflective member maintains high reflectance even in high-temperature environments, does not generate dust, and can be washed with chemical liquids. The method allows for complete sealing and shaping of the glass member with a heat reflective layer, ensuring low heat capacity and excellent heat insulation without compromising reflection performance or durability.
Implementation Method 1
heat insulating means which shields heat rays from an inside of the furnace and efficiently reflects the heat rays
Implementation Method 2
cutting it into shape using a laser, forming the impermeable and buffer layers simultaneously
Data Source
AI summary
One aspect is a heat reflective member, a laminated structure in which quartz glass layers are formed on an upper surface and a lower surface of a siliceous sintered powder layer. The heat reflective member has an impermeable layer formed at a portion of the siliceous sintered powder layer at a cut-out end portion of the heat reflective member. The impermeable layer has a thickness at least larger than half of a thickness of the siliceous sintered powder layer and through which a gas or a liquid is prevented from penetrating. A buffer layer is formed between the impermeable layer and the siliceous sintered powder layer next to the impermeable layer and spaced apart from the cut-out end portion. The buffer layer changes in density from the impermeable layer toward the siliceous sintered powder layer.