Laser Glass Fusing with Dynamic Heat Input Control
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Solution Overview
Problem
The existing glass fusing methods using laser irradiation often result in damage to glass members due to excessive heat input, causing cracks during the fusion process, primarily because the laser absorptance of the glass layer increases beyond its melting point, leading to heat shock.
Innovation Solution
A glass fusing method that involves initially irradiating a glass layer with a first laser beam to melt and fix it to a glass member, then switching to a second laser beam with lower heat input when the melting ratio exceeds a predetermined level, preventing excessive heat absorption and damage by maintaining a stable heat input.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a laser beam is used to melt and fix the glass layer onto the glass member, then the fusion process becomes more efficient and faster, but the glass member may incur damages such as cracks due to excessive heat input when the laser absorptance increases beyond the melting point
Solution Approach 1:
The patent applies dynamics by making the laser irradiation conditions adjustable and changeable during the process. The control unit dynamically adjusts laser power, irradiation speed, and irradiation pattern based on real-time monitoring of the glass layer's laser absorptance changes, allowing the system to adapt to the increasing absorptance as the glass layer melts and prevents excessive heat input that would cause cracking.
Solution Approach 2:
The patent implements feedback control by monitoring the glass layer's temperature or absorptance characteristics during laser irradiation and using this information to adjust the laser power and irradiation parameters. This closed-loop control ensures that the laser energy input remains within safe limits even as the glass layer's absorptance increases beyond its melting point, preventing thermal damage to the glass member.
2Reliability
If the laser power is increased to ensure complete melting of the glass layer during fusion, then the fusion bonding becomes more reliable, but the glass layer absorbs more than expected leading to heat shock and cracks in the glass member
Solution Approach 1:
The patent applies periodic action by using pulsed laser irradiation or intermittent irradiation patterns instead of continuous high-power irradiation. The control unit adjusts the duty cycle, pulse width, and frequency of laser pulses to provide sufficient total energy for complete melting while allowing thermal diffusion periods between pulses, thereby preventing heat accumulation and heat shock that would cause cracking.
Solution Approach 2:
The patent applies partial action by dividing the laser irradiation into multiple passes or zones, where different portions of the glass layer receive different amounts of energy. The control unit adjusts the irradiation pattern to ensure complete melting in critical bonding areas while using lower power in non-critical areas, preventing excessive heat input and heat shock damage to the glass member.
3Reliability
If a firing furnace is used to melt the glass layer, then the glass layer is firmly fixed to the glass member without damage, but the energy consumption and burning time increase significantly
Solution Approach 1:
The patent replaces the mechanical/thermal system of a firing furnace with a laser-based system. The laser beam provides concentrated, localized heating that melts and fixes the glass layer to the glass member without requiring the high overall temperature and long processing time of a firing furnace, thereby significantly reducing energy consumption while maintaining reliable fixation.
Solution Approach 2:
The patent applies local quality by using laser irradiation to heat only the specific region where the glass layer needs to be melted and fixed, rather than heating the entire glass member uniformly as in a firing furnace. This localized heating approach reduces the total energy required and shortens the processing time while ensuring firm fixation of the glass layer in the bonding region.
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 efficiently fuses glass members together while preventing damage, such as cracks, by controlling the heat input to the glass layer, ensuring a stable fusion process without excessive heat shock.
Implementation Method 1
irradiating the region to be fused therealong with a first laser beam having a first heat input, so as to melt the glass layer
Implementation Method 2
the laser absorptance of the glass layer drastically increases when the temperature of the glass layer exceeds its melting point
Implementation Method 3
the glass frit melts to fill the voids and loses the particle property, so that the laser-absorbing pigment remarkably exhibits its absorption characteristic
Implementation Method 4
the glass layer absorbs the laser beam more than expected, thereby generating cracks in the glass member because of a heat shock due to excessive heat input
Data Source
AI summary
When melting a glass layer 3 by irradiating a region to be fused R therealong with a laser beam L1, the region to be fused R is irradiated therealong with the laser beam L1 having a first heat input, so as to melt the glass layer 3, the heat input is switched when the melting ratio of the glass layer 3 in a direction substantially orthogonal to a moving direction of the laser beam L1 exceeds a predetermined level, and the region to be fused R is irradiated therealong with the laser beam L1 having a second heat input smaller than the first heat input, so as to fix the glass layer 3 to a glass member 4. This inhibits the glass layer 3 from falling into an excessive heat input state and thus deters the glass layer 3 from crystallizing during burning. The glass member 4 is fused to a glass member 5 through the glass layer 3 thus deterred from crystallizing, so as to yield a glass fusing structure 1.