Non-Contact Optical Detection of Foreign Materials Adhered to Color Filter and Thin-Film Transistor

Abstract

This paper describes the non-contact optical detection of debris material that adheres to the substrates of color filters (CFs) and thin-film transistors (TFTs) by area charge-coupled devices (CCDs) and laser sensors. One of the optical detections is a side-view illumination by an area CCD that emits a coherency light to detect debris on the CF. In contrast to the height of the debris material, the image is acquired by transforming the geometric shape from a square to a circle. As a result, the side-view illumination from the area CCD identified the height of the debris adhered to the black matrix (BM) as well as the red, green, and blue of a CF with 95, 97, 98, and 99% accuracy compared to the golden sample. The uncertainty analysis was at 5% for the BM, 3% for the red, 2% for the green, and 1% for the blue. The other optical detection, a laser optical interception with a horizontal alignment, inspected the material foreign to the TFT. At the same time, laser sensors intercepted the debris on the TFT at a voltage of 3.5 V, which the five sets of laser optics make scanning the sample. Consequently, the scanning rate reached over 98% accuracy, and the uncertainty analysis was within 5%. Thus, both non-contact optical methods can detect debris at a 50 μm height or lower. The experiment presents a successful design for the efficient prevention of a valuable component malfunction.

Keywords: area charge-coupled device; color filter; foreign material; laser sensor; thin-film transistor.

Figure 1

The struture of the photosensor that detects debris on the color filter (CF); (A) is a topology of the side-view illumination by the photosensor in the dark field, and (B) is the grayscale tendency.

Figure 2

The architecture of the laser sensor illustrating the topology of a thin-film transistor (TFT), (A) is a topology of the foreign materials on TFT by laser optics (B) is a voltage tendency.

Figure 3

The architecture of the optical detection system comprising (A) of CF at (1) glass-in, (2) CCD detection, (3) exposure machine, (4) glass-out; below diagram (B) of TFT includes (1) glass-in, (2) laser optic scanning, (3) array check system, and (4) glass-out.

Figure 4

The topology of the array check system indicating the components, especially the modulator.

Figure 5

The golden sample coating the colored photoresists (PRs) with heights of 130, 131, 155, and 146 μm. Row (A) indicates the various solder balls magnified by microscope 10×, (B) indicates the grayscale image, and (C) is enlarged 1600% by Photoshop software.

Figure 6

Images showing the grayscale with the threshold value for the black matrix (BM) as well as the red, green, and blue for the color filter (CF).

Figure 7

The distribution of the spectrum measures of the photoresists for the black matrix (BM), red, green, and blue.

Figure 8

The uniformity of the side-view illumination indicating the distribution.

Figure 9

The profile of the laser sensor indicating the five sets of receivers.

Figure 10

The EDX spectrum of the FISEM indicating the response of the material.

Figure 11

Analysis of the debris adhering to the modulator indicates (A) of the damaged modulator, (B) of scratch across the area, and (C) of the enlarged view.

Figure 12

Images of the debris enlarged by the microscope indicate the known heights (A) 125 μm, (B) 250 μm, and (C) 700 μm.