Plastic Film & Sheet Surface Inspection Systems

In-situ inspection with no active modules within the chamber

In coating applications, Dark Field’s SSLR technology allows inspection to be performed from outside the vacuum chamber during processing.

The laser reflector is installed in the chamber to capture and return light to the scanner. No electronics are required in the deposition chamber. Dark Field has built in-situ inspection systems with coating defect detection down to 1 micron.

Slot Die and Patch Coatings – Thickness Measurement Challenges

• On-line, real-time measurements required.
• Wet coating and post-dryer.
• Installation space often very tight.
• Precise point measurements required, not large area measurements.

Dark Field Solution

• Laser scanner(s) traverse the web.
• Wet and dry coating measurements.
• Very compact scanner – traversing scanner and support structure is only 4” wide (machine direction measurement).
• High precision coating profile: 1,000 measurements per second.

First Surface Inspection – The Problem

• The first surface of the glass may be the only surface of interest in a coating operation.
• Inspection systems should not report particles, stains, top tin and other defects on the second surface.

The Dark Field Solution

• Special SSLR scanner designed to inspect ONLY the first surface.
• Second surface is optically ignored.
• Inspection results show only first surface defects.

Haze Measurement Challenges

• Conventional haze measurement is on off-line operation; small samples, statistical, long time for feedback.
• Film and glass production need 100% on-line immediate haze mapping and measurement.  Identify areas of the web or sheet which are outside control limits.

Dark Field Solution

• Special SSLR technology provides 100% on-line, real-time haze measurement.
• Haze results correlate to Gardner Haze Gard Plus instrument and ASTM Haze Measurement standard #D1003.
• Warning and reject levels.  Real time alerts, alarms, marking.
• Data saved in XML and SQL database files.
• Integrated with defect detection results; single window operation.

Coating Detection Challenges

• Slow line speeds and long drying times mean that coating defects (skips, streaks and silicone release liner voids) must be detected prior to the oven.
• This means unwind inspection of the silicone release linear and wet coating inspection of the drug carrier while the coating is wet.
• Coating thickness measurement also required.
• Limited space and explosive environment mean difficult installation for conventional technologies.

Dark Field Solution: Solid State Laser Reflection (SSLR)

• Proven for wet coatings in explosive environments.
• Simplest, least space installation.
• Only self-aligning technology.

Transient Defects – Detection Challenges

• Transient defects must be detected in a vast array of high-end products: Electronic readers, Smart Phones/Pads, Smart Windows, etc.
• Transient defects are only visible during a color or state change; they can disappear quickly.
• Transient defects will cause the final assembly to be rejected; they must be captured prior to assembly.
• On-line technologies did not exist to detect transient defects on a production line.

Dark Field Solution

• Special optics and hardware processing modules make detection of transient defects simple and robust at line speeds over 30m/min.

Scratch Detection Challenges

• On-line Scratch and Sleek detection can be extremely difficult.
• Many systems cannot detect subtle scratches and sleeks.
• Scratches/Sleeks in the machine-direction (or conveyor direction) are the most common and the most difficult to detect.

Special Scratch/Sleek Detection

• Special optics detect subtle scratches and sleeks.
• Special  processing/software module improves scratch measurement.

Fuel Cell Defect Detection Challenges

• Cell media and coatings can be very light absorbing.
• Defect detection requires special optics.

Dark Field Solution

• Special optical solution for detection of dents, cracks, surface contamination, imbedded particles.

Membrane Defect Detection Challenges

• Detection of wet cast membrane, prior to annealing.
• Detection of pinholes in coating prior to annealing.

Dark Field Solution: Solid State Laser Reflection (SSLR)

• Proven for wet cast membranes, wet coatings and annealed membranes, on-line, 100%.
• Simplest, least space installation.
• Only self-aligning technology.

Turnkey Inspection Systems – Customer Needs

• Existing production line: Integration of the inspection system with the existing customer production line.
• Complete turnkey system – Stand alone: Stand-alone system – off-line and development, including roll unwind, rewind, sheet handling.

Dark Field Capabilities

• Existing production line: Dark Field provides complete interface and integration services.  This means mounting the system to the machine frame or the floor.  Customers only need to provide mounting holes or anchor bolts and power.  Dark Field does the rest, including I/O and data interfaces.
• Complete turnkey system – Stand alone: Custom solutions.  Systems are full production systems and can be easily modified/upgraded for relocation to the production line.

Defect Detection and Metrology Challenges

• Maximize efficiency and yield.
• Eliminate scrap.
• On-line, 100% coating defect detection and scribe metrology.

Dark Field Solutions

• Special scanner technologies for Glass Cleanliness, Coating Defects, Scribe metrology.
• Dozens of systems in the field; CIGS, CdTe.