Photovoltaic Wafer Thickness Sorting | TronSight TS-P Laser Sensor

New Energy03.Photovoltaic Wafer Thickness Sorting with Laser Triangulation Sensors

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New Energy03.Photovoltaic Wafer Thickness Sorting with Laser Triangulation Sensors

Aug 19, 2025

1. Importance of Wafer Thickness Sorting

In the photovoltaic (PV) industry, silicon wafer thickness plays a decisive role in:

Cell efficiency – uniform wafer thickness ensures consistent light absorption.
Mechanical stability – wafers that are too thin risk cracking, while overly thick wafers increase cost.
Production yield – sorting wafers by thickness prevents defective cells from entering downstream processes.
Cost optimization – precise sorting maximizes material utilization and reduces waste.

Accurate and high-speed thickness sorting is therefore critical in modern photovoltaic wafer production.

2. Common Measurement Methods

Measurement Method	Principle	Advantages	Limitations
Contact gauges	Mechanical probe measures thickness	Simple, low cost	Contact may damage fragile wafers, slow
Interferometry	Light interference determines thickness	High precision	Sensitive to vibration, less suited for inline
X-ray thickness gauge	Absorption of radiation	Non-contact, good accuracy	Safety concerns, high operating cost
Laser triangulation sensor	Laser reflection angle used to measure distance	Non-contact, fast, inline compatible	Reflective surfaces may require optimization

3. Principle and Process of Laser Triangulation Measurement

Laser triangulation displacement sensors work based on geometric principles:

Laser projection – the sensor projects a laser spot onto the wafer surface.
Reflection detection – the reflected light is captured by a position-sensitive detector (PSD/CMOS).
Angle calculation – the position of the reflection spot determines the distance.
Thickness evaluation – measuring both wafer surfaces or comparing to a reference allows thickness sorting.

Why it suits photovoltaic wafers:

Non-contact, avoids micro-cracks on fragile wafers.
High sampling rate supports inline high-speed sorting.
Sub-micron precision ensures consistent wafer grading.

4. TronSight’s Solution

The TronSight TS-P Series Laser Triangulation Displacement Sensor is designed for demanding thickness sorting tasks:

160kHz sampling rate, supporting real-time wafer sorting in production lines.
±0.02% of F.S. linear accuracy for reliable thickness evaluation.
0.02μm repeatability, detecting even subtle thickness variations.
2~2000mm measurement range, adaptable to various wafer formats.
Customizable optics (line width, wavelength, structure size) for optimized performance on reflective silicon wafers.
Built-in controller simplifies integration into sorting systems.

Application Example (conservative wording):
In photovoltaic wafer production, TS-P sensors can be integrated into sorting equipment to measure and classify wafers based on thickness. The data helps improve production yield and process stability.