SiC Substrate Saw Blade Alignment for Crack Reduction
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Solution Overview
Problem
The existing methods for singulating semiconductor substrates, particularly those with non-cubic crystalline lattices like silicon carbide, often result in cracks, chips, and increased wear of saw blades due to improper alignment with crystal planes, leading to inefficiencies and defects during the dicing process.
Innovation Solution
The method involves aligning a saw blade substantially perpendicularly with the crystal plane of a semiconductor substrate, cutting at an angle perpendicular to the crystal plane to mitigate crack formation and using a diamond studded saw blade to extend blade life and improve cutting efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a saw blade is aligned perpendicular to the largest planar surface of the substrate, then the cutting process is simple, but cracks and chips occur due to misalignment with crystal planes
Solution Approach 1:
The patent changes the alignment parameter from perpendicular to the substrate surface to perpendicular to the crystal plane. This requires tilting the saw blade or substrate by the off-angle (e.g., 4 degrees for silicon carbide) to achieve proper alignment with the crystal structure, thereby preventing cracks and chips while maintaining cutting effectiveness
Solution Approach 2:
The patent replaces simple geometric alignment (perpendicular to surface) with crystallographic alignment (perpendicular to crystal plane). This substitution requires using crystal orientation data and off-angle measurements to determine the correct cutting angle, replacing intuitive mechanical alignment with scientifically-based positioning
2Ease of manufacture
If a standard saw blade is used for cutting silicon carbide substrates, then the cutting process is straightforward, but the blade wears quickly
Solution Approach 1:
The patent specifies using diamond-studded saw blades for cutting silicon carbide substrates. Diamond, being harder than silicon carbide, provides superior cutting capability and extended blade life. This composite approach combines the saw blade structure with diamond abrasive elements to achieve both effective cutting and durability
Solution Approach 2:
The patent changes the material parameter of the saw blade from standard abrasive to diamond-studded. This material substitution is necessary because silicon carbide is an extremely hard material that requires diamond, the hardest known material, to achieve effective cutting with acceptable blade life
3Productivity
If the saw blade cuts entirely through the substrate in one pass, then the process is efficient, but crack formation increases due to improper angle
Solution Approach 1:
The patent changes the cutting angle parameter from perpendicular to the substrate surface to perpendicular to the crystal plane. This angle adjustment (tilting by the off-angle) enables single-pass cutting through silicon carbide substrates without causing cracks or chips, thereby maintaining high productivity while ensuring manufacturing precision
Solution Approach 2:
The patent requires preliminary determination of the crystal plane orientation and off-angle measurement before cutting. This preliminary action of aligning the saw blade or substrate to the correct angle based on crystallographic data prevents crack formation during the cutting process, enabling defect-free single-pass cutting
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 approach reduces the risk of cracks and defects, increases cutting speed, and extends the life of the saw blade, providing cost benefits and improved processing efficiency for silicon carbide semiconductor substrates.
Implementation Method 1
using a diamond studded saw blade to extend blade life and improve cutting efficiency
Data Source
AI summary
Implementations of methods of cutting a semiconductor substrate may include aligning a first saw blade substantially perpendicularly with a crystal plane of a non-cubic crystalline lattice of a semiconductor substrate coupled with a backmetal layer and cutting through at least a majority of the semiconductor substrate at an angle substantially perpendicular with the crystal plane of the non-cubic crystalline lattice of the semiconductor substrate. The method may also include aligning a second saw blade substantially perpendicularly with the semiconductor substrate and cutting entirely through the semiconductor substrate and the backmetal layer using the second saw blade.