Ceramic Substrate Laser Scribing for Uniform Low-Oxidation Splitting
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Solution Overview
Problem
Conventional methods for splitting large, thin ceramic substrates with high strength and toughness, such as silicon nitride substrates, face challenges in forming deep scribe lines efficiently without excessive heat generation, leading to uneven splitting and potential oxidation, which affects the reliability and manufacturing yield.
Innovation Solution
A method involving laser processing with controlled conditions, including specific peak observations in X-ray Photoelectron Spectroscopy (XPS) ranges, optimized laser parameters, and assist gas use to form scribe lines that reduce heat effects and ensure uniform splitting, enhancing the strength and thermal conductivity of ceramic substrates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If laser processing is performed to form deep scribe lines in high-strength thin ceramic substrates, then the substrate can be split into multiple pieces, but excessive heat generation occurs leading to oxidation and uneven splitting
Solution Approach 1:
The patent employs periodic pulsed laser irradiation instead of continuous laser processing. The laser is irradiated in multiple pulses with specific intervals, allowing heat dissipation between pulses and preventing excessive temperature rise that causes oxidation and uneven splitting while still achieving deep scribe lines in high-strength thin substrates
Solution Approach 2:
The patent performs preliminary surface treatment or pre-scribing before the main laser processing. This preliminary action prepares the substrate surface to reduce laser absorption and heat generation during subsequent processing, thereby minimizing oxidation and heat-affected zones while maintaining splitting accuracy
2Temperature
If the substrate thickness is reduced to improve heat dissipation, then thermal conductivity increases, but the substrate becomes more difficult to process and split uniformly
Solution Approach 1:
For thin substrates requiring efficient heat dissipation, the periodic pulsed laser processing prevents excessive heat accumulation that would cause warping or uneven splitting. The pulse intervals allow thermal diffusion through the thin substrate, maintaining dimensional stability and splitting uniformity while preserving the thin profile for heat dissipation
Solution Approach 2:
The patent adjusts laser processing parameters (pulse width, frequency, power, scan speed) specifically optimized for thin substrate thickness. These parameter changes enable controlled energy input that achieves sufficient scribe depth in thin substrates without causing the substrate to warp or split unevenly, maintaining both heat dissipation performance and manufacturing precision
3Productivity
If high laser energy is used to scribe deep lines quickly, then processing speed increases, but heat effects intensify causing oxidation and reducing substrate strength
Solution Approach 1:
The periodic pulsed laser processing achieves high processing speed through optimized pulse frequency and scan speed, while the pulse intervals allow heat dissipation that prevents oxidation and maintains substrate strength. This periodic action decouples the relationship between processing speed and heat accumulation, enabling fast processing without compromising substrate integrity
Solution Approach 2:
The patent maintains continuous forward motion of the laser beam across the substrate at optimized scan speeds, ensuring high productivity. Combined with pulsed irradiation, this continuous scanning ensures uniform processing along the scribe line while the pulse timing controls heat input, preventing oxidation and strength degradation even at high processing speeds
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 method achieves high-strength, high-thermal conductivity ceramic substrates with reduced oxidation and improved splitting accuracy, resulting in enhanced reliability and manufacturing efficiency.
Implementation Method 1
a method in which the silicon nitride substrate is split into multiple pieces using scribe lines formed by laser processing
Implementation Method 2
Conventional measurement of laser-processed surfaces by X-ray Photoelectron Spectroscopy (XPS)
Data Source
AI summary
In a ceramic substrate according to an embodiment, there are two or more peaks within a range of 98 eV or higher and 106 eV or lower in a spectrum obtained by measuring a laser-irradiated zone on a laser-processed surface by X-ray Photoelectron Spectroscopy (XPS). A ceramic circuit board and a semiconductor device including the ceramic substrate are provided. Methods for manufacturing the ceramic substrate and a ceramic split substrate are also provided.