Exploring New Industry Standards in Photovoltaic Cutting Technology

As the photovoltaic industry accelerates toward the 700W+ high-power era, laser dicing machines have become the core equipment determining module efficiency and cost. ChinTiyan New Energy (Hubei) Co., Ltd.'s CTC series laser dicing machines redefine industry standards for photovoltaic cell dicing processes with ±0.02mm cutting precision, breakthrough production capacity of 7,200 cells per hour, and full-size compatibility.

I. Core Technology: Physical Breakthrough in Laser Non-Destructive Cutting

Traditional mechanical dicing relies on diamond wheels applying pressure to cut, facing three major technical bottlenecks: high hidden crack rate (up to 0.5%) due to thermal damage, significant waste of silicon material (over 5%) caused by wide cut width (80μm), and inability to accommodate ultra-thin wafers below 100μm. ChinTiyan New Energy's CTC series dicing machines employ fiber laser thermal stress cracking technology, achieving breakthroughs in physical limits through three innovations:

1. Beam Focusing Control

Utilizing a MOPA pulsed laser, the spot diameter is compressed to 20μm with an energy density of 10⁸W/cm², enabling “cold cutting.” The heat-affected zone width is <20μm, reducing it by 60% compared to traditional mechanical dicing.

2. Thermal Stress-Induced Cracking

Laser scanning creates internal temperature gradients within the wafer. Exploiting the thermal expansion coefficient difference between silicon (2.6×10⁻⁶/℃) and glass substrates (0.5×10⁻⁶/℃), a controlled stress field induces controlled separation along predetermined paths. Experimental data shows this technology achieves stress uniformity error <3MPa for 182mm wafers, significantly outperforming mechanical scribing's 15MPa.

3. Multi-Axis Interlinked System

Integrates high-precision linear motors with optical positioning modules, achieving positioning accuracy of ±0.05mm and supporting 1/2 to 1/6 wafer splitting processes. Taking the CTC-80S model as an example, its cutting speed reaches 7,200 wafers per hour—a 300% increase over traditional equipment. The kerf width is controlled within 30μm, boosting silicon material utilization to 98.5%. The wafer breakage rate remains below 0.02%, significantly outperforming the industry average of 0.1%.

II. Equipment Advantages: A Manufacturing Powerhouse for All Scenarios

1. Full-Size Compatibility

The equipment supports cutting silicon wafers ranging from 156mm to 230mm in size, covering all technology routes including PERC, TOPCon, HJT, and IBC. For 210mm large-size wafers, dynamic focusing technology adjusts the laser focal point in real time, ensuring cutting depth consistency with <5μm deviation. This effectively resolves cutting inaccuracies caused by wafer warping. Production line data from a leading enterprise shows the CTC-60 achieves a 99.5% yield rate when cutting 210mm wafers—an 8-percentage-point improvement over mechanical sawing machines.

2. Ultra-Thin Wafer Cutting Capability

By optimizing laser pulse parameters (frequency 15-20kHz, pulse width 50-100ns) and auxiliary gas pressure (0.3-0.5MPa nitrogen), the CTC series achieves stable cutting of 80μm ultra-thin silicon wafers. In field testing at a heterojunction (HJT) cell manufacturer, the yield rate for cutting 100μm HJT cells reached 99.2%, a 12-percentage-point improvement over mechanical dicing, clearing a key hurdle for HJT cell mass production.

3. Intelligent Production System

The equipment integrates three core intelligent modules:

• Visual Positioning System: Utilizes a 5-megapixel industrial camera combined with deep learning algorithms to achieve automatic alignment at 0.1 seconds per wafer, with repeatability error <0.03mm.

• Process Database: Pre-loaded with over 200 cutting parameter templates, enabling one-click switching between processing techniques for different cell types with parameter transition time <5 seconds.

• Remote O&M Platform: IoT modules transmit real-time equipment status data, achieving 95% fault prediction accuracy to minimize unplanned downtime. Production line data from a top-5 module manufacturer shows that after introducing the CTC-60 model, single-line annual capacity increased from 18MW to 25MW, reducing the payback period per unit of capacity investment to 1.2 years.

III. Process Specifications: Standardized Workflows for Lean Manufacturing

1. Environmental Parameter Management

• Temperature and Humidity Control: Maintain workshop temperature between 20-25°C with humidity <60% to prevent laser condensation;

• Cleanliness Requirements: Achieve ISO Class 7 cleanliness (≤1 million particles ≥0.5μm per cubic foot of air) to avoid burrs on cut edges caused by dust;

• Water-Cooling System Maintenance: Deionized water conductivity must be <1μS/cm to prevent laser cavity corrosion; cooling water flow rate must be stable at 4-6L/min.

2. Cutting Parameter Optimization

3. Quality Inspection Standards

• Online Inspection: Real-time monitoring of cut width via laser interferometer at 1000 samples/second;

• Random Sampling: 1 cell per 200 cells sampled for EL testing to detect microcracks;

• Data Traceability: Unique ID binding per cell to record cutting parameters and quality data, enabling full lifecycle traceability.

Future Outlook: Technology Iteration Driving Industry Upgrades

As PV technology evolves toward N-type, thin-film, and busbar-less (0BB) designs, laser dicing machines will face three key development trends:

1. Ultra-Precision Processing Requirements

0BB technology demands cutting accuracy improved to ±0.01mm. Chintiyan New Energy has developed the CTC-100S prototype using a 355nm UV laser, achieving ±8μm precision, with mass production expected by 2026.

2. Integrated Scoring and Welding

To address welding precision challenges posed by multi-busbar technology, ChinTiyan New Energy is developing integrated scoring-welding machines that combine dicing and string welding processes. By sharing a vision positioning system to reduce positioning errors, this technology is projected to decrease production line footprint by 30% and boost efficiency by 25%.

3. Perovskite Tandem Adaptation

To meet flexible substrate cutting demands for perovskite/crystalline silicon tandem cells, the company has initiated picosecond laser dicing R&D. The goal is to achieve damage-free separation of layers below 50μm with cutting speeds exceeding 10,000 wafers per hour.