LATEST TECHNOLOGY
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| Description of Technology For Inspection of Etched and Printed Organic Electronics |
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Currently inspection systems use reflected light to illuminate a sample. This is done by shining a beam of light onto the surface, with the reflected image recorded by a camera, as shown on the left in Figure 1a below. However sometimes upon inspection, while the image would suggest there is no conductor present, conductive material may actually be there causing a short circuit. This occurs when the surface of the conductor is not flat and perpendicular to the camera (increasingly so as people work on flexible substrates), the incident light is reflected off at an angle and not detected by the camera, as seen by the image on the right in Figure 1b below.
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Beltronics has patented an inspection system to overcome this problem. Organic materials used in fabrication of organic electronic components slightly fluorescence. This fluorescence is created at the surface of the material and therefore unlike the incident light it is transmitted in all directions. Beltronics has devised a way to detect this slight fluorescence and therefore the presence of organic material, as shown in Figure 1C. Metal conductors which do not fluoresce appear dark and the organic substrate appears bright independent of curvature, angle or flatness of the substrate. Organic material as thin as an incredible 410 angstroms has been detected using this technology. The results are striking. In the Mscan white light image of Figure 2a, a fatal short cannot be seen. In the Mscan fluorescent image of Figure 2b, the short is obvious.
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Reflected Light Image
Figure 2a |
Fluorescent Image Showing Short
Figure 2b | |
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Unique to the Beltronics Mscan systems is the ability to detect extremely small defects at high speeds from weakly fluorescing materials.This is achieved in part by using high resolution optics with a wide cone angle of collection to insure that most of the fluorescent rays are detected by the camera, as shown in Figure 3.
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Fluorescent Sample |
Fluorescent Sample |
High NA optics collects more fluorescent light rays over the larger cone angle S2 than low NA optics collects over the smaller angle S1 but loses focus more rapidly. This illustrated by comparing the blurred spot size for the high and low NA lens.
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Figure 3
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Most commercial systems do not use such high resolution optics because the depth of focus is very small and the image of the part goes out of focus as the part is scanned. Beltronics has patented technology to maintain focus while scanning non-flat materials. Figure 4 shows a two dimensional topology map of a non-flat substrate with160 micron between the peaks and valleys. The sample was inspected at 2 micron resolution. Pixel size is adjustable down to 200 nanometers.
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Topology Map of 200mm x 200mm
3-Dimensional Sample
Inspected at 2 Micron Resolution
Figure 4 |
Beltronics Mscan Inspection System
Figure 5 | |
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MSCAN HIGHLIGHTS
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Mscan Systems for Inspection of Organic and Non-Organic Products
Product Line Highlights and System Specifications |
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The Mscan System is comprised of multiple optical and image processing modules optimized for inspection of organic and non-organic products. These modules can be rapidly configured for specific customer manufacturing requirements. Features common to the Mscan line of products are:
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- Pixel sizes adjustable: 10 microns down to 200 nanometers
- Stage sizes available: 300mm x 300mm up to 600mm x 800mm
- Illumination: reflected, transmitted, and fluorescent excitation
- Auto focus, surface tracking and high resolution optics incorporated in all Mscan systems
- Inspection time is constant and independent of circuit density or the number of defects detected
- Design Rule and Inspection to CAD Data is performed simultaneously for maximum throughput
- Spatial tolerances can be added to the design rules and CAD data to tolerate edge roughness, shrinkage, expansion and process variations
- Custom electronics giga-pixel per second real time signal processing for maximum throughput
- Processor FPGAs (Field Programmable Gate Array) based - enables rapid response to new customer requirements and future in field upgrades
- Defect images are grabbed during the inspection scan and stored in a data base for statistical analysis.
- Defect review window provides defect map, coordinates, imagery and statistical data
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 Mscan Defect Review Window
Figure 6 |
All this at high speed too - For a 300mm x 300mm part with 50 micron lines, scan time on the Beltronics Mscan System (Figure 5) is on the order of 8 seconds. Scan time is a function of inspection area, system resolution and hardware configuration, which can be optimized to meet manufacturing requirements. Beltronics offers Mscan systems with a wide range of auto handlers and standard stages ranging from 300mm x 300mm to 600mm x 800mm in travel. Custom stage sizes are available. Specific scan times will be quoted upon request as a function of customer configuration.
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