Fixed-Diamond Abrasive Wire-Saw Cutting Force Modeling Based on Changes in Contact Arc Lengths

At a Glance

Metadata	Details
Publication Date	2023-06-20
Journal	Micromachines
Authors	Liang Lie, Shujuan Li, Kehao Lan, Jiabin Wang, Ruijiang Yu
Institutions	Xi’an University of Technology
Citations	10
Analysis	Full AI Review Included

Fixed-Diamond Abrasive Wire-Saw Cutting Force Modeling: Technical Analysis and 6CCVD Solutions

Executive Summary

This technical documentation analyzes the research on Fixed-Diamond Abrasive Wire-Saw (FAW) cutting force modeling for monocrystalline silicon (Si). The findings are critical for engineers requiring high-precision material removal and surface quality control.

Core Achievement: Development of an iterative algorithm modeling contact arc length, random abrasive distribution, and cutting force during FAW slicing of hard, brittle materials (Si).
Model Reliability: The simulation demonstrated high accuracy, with errors in stable-stage average cutting force less than 6% compared to experimental results.
Key Variables Identified: Cutting force ($F_n$) is directly proportional to the part feed rate ($V_x$) and inversely proportional to the wire velocity ($V_s$).
Process Dynamics: The cutting process is characterized by two stages: an initial rising stage (material accumulation, increasing bow angle) and a stable stage (material removal capacity matches feed rate).
Surface Quality Prediction: The model successfully predicts wafer surface morphology, including saw mark curvature and central angle, with errors less than 5%.
Material Relevance: The study validates the necessity of precise control over fixed diamond abrasive geometry and distribution for achieving high-quality Si wafers, a foundational step for advanced semiconductor device fabrication.

Technical Specifications

The following hard data points were extracted from the experimental and simulation results, focusing on the parameters governing the FAW process and the resulting material characteristics.

Parameter	Value	Unit	Context
Workpiece Material	Monocrystalline Silicon (Si)	N/A	Hardness (H) = 13.5 GPa
Workpiece Size (Cutting Surface)	36 x 23	mm	Rectangular ingot
Wire Saw Radius ($R_w$)	0.1	mm	JR2-type diamond abrasives
Abrasive Density (C)	34	particles/mm²	Distribution density on wire surface
Abrasive Tip Half Angle ($\theta$)	65	°	Assumed conical abrasive shape
Wire Tension (T)	15	N	Initial tension setting
Part Feed Rate ($V_x$) Tested Range	0.5 to 1.0	mm/min	Key variable affecting cutting force
Wire Velocity ($V_s$) Tested Range	1.0 to 1.5	m/s	Key variable affecting cutting force
Stable Stage Cutting Force ($F_n$)	0.85 to 1.81	N	Experimental range across tested parameters
Cutting Force Model Error	< 6	%	Error between simulation and experiment
Saw Mark Curvature Error	< 5	%	Error between simulation and experiment

Key Methodologies

The research employed a combined theoretical modeling and experimental validation approach to analyze the FAW cutting process.

Geometric Modeling: Established a mathematical model for the contact arc length ($S$) and wire bow angle ($\gamma$) based on the part thickness ($L_c$) and the bending distance of the wire ($h$).
Abrasive Distribution Modeling: Used Scanning Electron Microscopy (SEM) (Merlin Compact SEM, EHT = 20.00 kV) to characterize the fixed diamond abrasive particles. Modeled the random distribution of abrasive particles using MATLAB, assuming a normal distribution for particle height.
Force Calculation: Developed an iterative algorithm to calculate the cutting force ($F_n$) based on the combined tension component and the sum of forces exerted by individual abrasive particles ($F_a$).
- $F_a$ is related to the depth of penetration ($g$), abrasive tip angle ($\theta$), and material hardness ($H$).
Material Removal Rate: Calculated the volume of material removed by abrasive particles ($U_w$) and compared it to the volume required by the part feed rate ($U_p$). The accumulation of unremoved material dictates the change in wire bow angle ($h$).
Experimental Validation: Used a WXD170 single-line reciprocating FAW machine to cut monocrystalline Si ingots. An ATI FT19500 dynamometer measured forces (32 N range in X-Y).
Surface Analysis: Keyence VHX-5000 ultra depth-of-field 3D microscope was used to measure saw mark curvature and central angle on the resulting Si wafers for comparison with simulation predictions.

6CCVD Solutions & Capabilities

The research highlights the extreme precision required in diamond-based slicing of hard materials like silicon and silicon carbide (SiC, mentioned in references). 6CCVD provides the foundational MPCVD diamond materials necessary for advancing these high-precision applications, whether for advanced tooling or for the resulting semiconductor devices.

Applicable Materials for Advanced Slicing and Device Fabrication

To replicate or extend this research, particularly into materials like SiC or for creating high-performance diamond components, 6CCVD recommends the following materials:

6CCVD Material	Application Relevance	Key Features
Optical Grade SCD	High-power laser optics, windows, or anvils requiring ultra-low surface roughness (Ra < 1nm).	Highest purity, lowest defects, ideal for precision metrology or high-energy applications.
Thermal Grade PCD	Heat sinks for high-power Si or SiC devices (post-slicing application).	High thermal conductivity (> 1800 W/mK), available in large plates (up to 125mm).
Heavy Boron Doped PCD (BDD)	Electrochemical sensors or electrodes used in harsh environments.	Electrically conductive diamond, highly stable and wear-resistant.
Tooling Grade SCD/PCD	Potential use in advanced micro-tooling or wear parts for the wire saw system itself.	High hardness, excellent wear resistance, custom geometries available.

Customization Potential for Research Extension

The paper emphasizes the importance of precise geometry, contact length, and surface quality. 6CCVD’s in-house capabilities directly support researchers needing highly customized diamond components:

Custom Dimensions: While the paper focuses on Si wafers (36 mm x 23 mm), 6CCVD can supply PCD plates/wafers up to 125mm in diameter, enabling scaling of research to larger industrial formats.
Thickness Control: We offer precise thickness control for both SCD (0.1 µm to 500 µm) and PCD (0.1 µm to 500 µm), crucial for applications requiring specific thermal or mechanical properties.
Ultra-Precision Polishing: The quality of the sliced wafer surface is paramount. 6CCVD provides:
- SCD polishing to Ra < 1nm.
- Inch-size PCD polishing to Ra < 5nm.
Custom Metalization: For researchers integrating diamond into devices (e.g., thermal management layers or electrodes), 6CCVD offers internal metalization services, including Au, Pt, Pd, Ti, W, and Cu layers, ensuring robust electrical or thermal contacts.

Engineering Support

The iterative modeling approach used in this paper requires deep material and process understanding. 6CCVD’s in-house PhD team specializes in the growth and characterization of MPCVD diamond. We can assist researchers with:

Material Selection: Guidance on selecting the optimal SCD or PCD grade based on required hardness, thermal conductivity, or electrical properties for similar Hard Material Processing or Semiconductor Device Fabrication projects.
Design for Manufacturing (DFM): Consultation on optimizing diamond component design to maximize performance in extreme mechanical or thermal environments, leveraging our expertise in diamond crystal orientation and defect control.
Global Logistics: Global shipping is available (DDU default, DDP available) to ensure timely delivery of custom materials worldwide.

For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly.

View Original Abstract

Monocrystalline silicon is widely used in the semiconductor market, but its hard and brittle physical properties make processing difficult. Fixed-diamond abrasive wire-saw (FAW) cutting is currently the most commonly used cutting method for hard and brittle materials due to advantages such as narrow cutting seams, low pollution, low cutting force and simple cutting process. During the process of cutting a wafer, the contact between the part and the wire is curved, and the arc length changes during the cutting process. This paper establishes a model of contact arc length by analyzing the cutting system. At the same time, a model of the random distribution of abrasive particles is established to solve the cutting force during the cutting process, using iterative algorithms to calculate cutting forces and chip surface saw marks. The error between the experiment and simulation of the average cutting force in the stable stage is less than 6%, and the errors with respect to the central angle and curvature of the saw arc on the wafer surface are less than 5% between the experiment and simulation. The relationship between the bow angle, contact arc length and cutting parameters is studied using simulations. The results show that the variation trend of the bow angle and contact arc length is consistent, increasing with an increase in the part feed rate and decreasing with an increase in the wire velocity.

Tech Support

Original Source

DOI: https://doi.org/10.3390/mi14061275

References

2020 - Experiment and theoretical prediction for surface roughness of PV polycrystalline silicon wafer in electroplated diamond wire sawing [Crossref]
2017 - Analytical Force Modeling of Fixed Abrasive Diamond Wire Saw Machining With Application to SiC Monocrystal Wafer Processing [Crossref]
2023 - Study on nanometer cutting mechanism of single crystal silicon at different temperatures [Crossref]
2023 - Molecular dynamics simulation on crystal defects of single-crystal silicon during elliptical vibration cutting [Crossref]
2022 - Theoretical study on sawing force of ultrasonic vibration assisted diamond wire sawing (UAWS) based on abrasives wear [Crossref]
2020 - Characterization of electroplated diamond wires and the resulting workpiece quality in silicon sawing [Crossref]
2018 - Experimental investigation of tool wear in electroplated diamond wire sawing of silicon [Crossref]
2012 - Silicon Crystal Growth and Wafer Technologies [Crossref]
2016 - Wire sawing technology: A state-of-the-art review [Crossref]
2011 - Investigation of long waviness induced by the wire saw process [Crossref]