Solar Panel Inspection

The purpose of the Glass Breakage metrology tool is to determine Go/No-Go (Pass/Fail) conditions for every glass panel inspected. This is accomplished by identifying defects such as cracks, chips, and breakage in either a coated or uncoated glass panel. 

Details:

• The custom frame enclosure houses a linescan camera, LED lights, and photoeyes.
• The camera vision system captures images of the panels as they pass by the instrument on a conveyor.
• LED lights illuminate the panels to help distinguish between defects and minor irregularities.
• Photoeyes detect the leading and trailing edges of the panels to trigger the system to start and stop data collection.
• High-resolution encoders trigger spatially-resolved linescans as the panel moves under the LED lighting, generating a high-resolution image of the panel for detailed image processing and defect detection.
• The CPU provides image processing and data storage capabilities.

The In Situ Film Thickness metrology tool is a non-contact, non-destructive, real-time thin film characterization sensor that utilizes the detailed spectral analysis of specularly reflected light from the solar panel. This system is designed to monitor film thickness directly on coater tools.

Details:

• Proprietary k-Space spectral fringe analysis determines semi-transparent thin-film thickness in real-time.
• k-Space software analyzes the below-gap spectral interference fringes to determine the total film thickness.
• The system acquires spectra data and determines thickness in real-time, all without interfering with the production line.
• Typical systems include 2 probes per tool (left channel and right channel).
• A sapphire reference normalizes the light source output.
• The tool detects panels through a threshold signal level (peak intensity of raw spectrometer signal).

The Inline Film Thickness and Roughness metrology tool is a post-coater metrology tool that analyzes the below-gap spectral interference fringes to determine the total film thickness.  In addition, it determines film roughness by inspecting the envelope of the interference spectra.

Details:

• The system performs final film thickness and surface roughness measurements after the  coating has been applied.
• The software utilizes proprietary k-Space spectral fringe analysis.
• Typical systems include 2 probes per tool (left channel and right channel).
• The inline tool includes inline sapphire references that sit approximately 2mm below the bottom surface of the panels. 
• The spectrometers are Flat-Field-Corrected (FFC) to ensure proper roughness measurement and tool-to-tool roughness matching.
• The tool detects panels through a threshold signal level (peak intensity of raw spectrometer signal).

The Transmission metrology tool measures transmission signal directly through the panel. It measures both material band edge (if present) and Integrated Band Absorption (IBA) values simultaneously. 

Details:

• The tool continually recalibrates between every panel by making a full transmission measurement between panels.
• An integrating sphere on the underside (transmission) collects all signal for proper, absolute transmission and IBA measurement.
• The tool detects panels through a threshold signal level (peak intensity of raw spectrometer signal below between-panel transmission signal).
• Standard systems include 2 probes per tool. 

The negative PhotoResist metrology tool is a non-contact, non-destructive, real-time thin-film characterization system that measures nPR (negative PhotoResist) thickness via a thin film interference fringe analysis.  This is a delta thickness measurement that will require a pre-measurement of the underlying base film thickness to determine the final thickness of the nPR. 

Details: 

• A sapphire reference normalizes the light source output.
• The tool detects panels through a threshold signal level (peak intensity of raw spectrometer signal).
• Standard systems include 2 probes per tool.
  

The Absolute Spectral Reflection metrology tool measures absolute spectral reflectance to characterize various films, including anti-reflection coatings (ARC). The system utilizes a 340-930nm spectrometer. An internal quartz reference continuously calibrates the absolute reflectance between panels.

Details:

• The tool uses an internal quartz reference and beam splitting optics to recalibrate between every panel.
  
• The tool measures color information (L*a*b* parameters) and scales the values to the sun light output distribution function.
• The optional kSA FitTool simulation and fitting software adds the ability to determine film thickness.
• A sapphire reference normalizes the light output signal.
• The tool detects panels through a threshold signal level (peak intensity of raw spectrometer signal).
• Standard systems include 3 probes per tool.

The Panel Edge metrology tool utilizes high-resolution 406nm laser line profilers to measure the edge profile of the panel/module.

 Details:

• The main parameters measured with this tool are edge radius of curvature, chip and crack detection and size, and debris detection. 
• The system uses mountable, custom gauge blocks to calibrate each head for height and radius of curvature measurement.
• The tool detects panels through a threshold signal level (peak intensity from reflected laser line profile).
• Standard systems include 2 probes per tool.    

The Panel Thickness and Warp metrology tool measures total panel thickness, bow, warp, and total thickness variation (TTV).  The tool utilizes 10 laser-based height sensors (5 above and 5 below) to measure at 5 stripe positions along the panel.

Details:

• Colinear laser sensors determine the panel thickness by measuring the panel height on top and bottom. As such, vertical movement/bounce of the panel does not affect the measurement, because the delta height measurement accounts for the  height offset.
• The software deduces bow, warp, and TTV measurements from the individual height measurements.
• Standard systems include 10 probes per tool (5 top and 5 bottom, for 5 stripe positions).