Infrared Imaging: Seeing the Invisible

Part Three:

Applications

• Quality Inspection (Solar Cells, Semiconductors, or PCBs; Laser Beam Profiling)

• Industrial Inspection

• Early Fire/Hazard Detection

Automation &

Process Control

Application Bank Note Authentication

Spectral Range Visible; NIR; SWIR;

Functionality Certain safety features disappear or become visible when exposed to infrared light. In the examples certain areas of the notes are not visible.

Notes Sometimes special filters are required, e.g. $-note: 1262 nm – 1338 nm band pass filter

False

Real

Application Wafer / Solar Cell Inspection

Spectral Range (Visible); NIR; SWIR

Functionality Luminescence imaging helps to identify non-uniformities in the silicon wafer or solar cell by forcing it to emit light: • Electroluminescence (EL)

A solar cell emits light / heat in response to electric current flow

• Photoluminescence (PL) A solar cell emits light / heat in response to being exposed to light

Notes Typical peak emission wavelength for different wafer materials: CdTe: 800 nm, Si: 1150 nm, CIGS: 1300 – 1700 nm, CIS: 1300 nm

Application Recycling – Paper Sorting

Spectral Range LWIR

Functionality Paper is processed on a conveyor belt and exposed to heat. Just after the heater a camera detects the differences in temperature that varies with the quality (thickness) of the paper.

Notes Very small temp. differences need to be identified <50 mK

Application Semiconductor Inspection

Spectral Range SWIR

Functionality Silicon is transparent at wavelength above 1100 nm. This enables to look through the silicon to see underlying structures.

Notes Usage of magnification lenses

Contacts at backside of a TFT display

Underlying structures in a wafer

Transparency of materials at specific wavelength (e.g. plastics) can also be used for other inspection tasks!

Application Moisture Detection

Spectral Range NIR / SWIR; MWIR

Functionality Water absorbs strongly at specific wavelengths, e.g.: 1.45, 1.9, 2.9, and 6 µm By using a corresponding filter or lighting, this feature can be used for various inspection tasks: • Verification of coatings or dryness

uniformity in bulk material • Fill level detection in bottles • Detection of damaged fruit • Gauging relative water content in

plants

Notes Use corresponding filters to emphasize features

• Speed Enforcement

• Red-Light Violation

• Traffic Monitoring at Night

Traffic Imaging &

Intelligent Transportation Systems

• Hyperspectral Imaging

• Agricultural Research (Plant Inspection)

• Medical (Fever Detection ; Arthrosis Diagnosis)

Science & Research

Application (Hyper) Spectral Imaging

Spectral Range Visible; NIR; SWIR; MWIR; LWIR

Functionality Incoming light is split into many bands before it falls on the detector. Hyperspectral data contains both spatial and spectral information from objects within a given scene. Each image of a scene represents a specific band of the electromagnetic spectrum. All 'images' together build three-dimensional hyperspectral data cube for processing and analysis.

• Security

• Law Enforcement

• Border Control

• Anti-piracy

Surveillance

Civil

• Building Diagnostics

• Firefighting

• Night Vision

• Border Control

Homeland Security

Allied Vision Technologies GmbH Taschenweg 2a 07646 Stadtroda, Germany Tel.: +49 36428 / 677-0 Fax: +49 36428 / 677-24

info@alliedvisiontec.com www.alliedvisiontec.com

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