A film edge distance measurement method and measurement device

Abstract

The invention provides a film edge distance measuring method and device and relates to the technical field of liquid crystal display. The distances between the film edges of protective film layers and the edges of substrates can be measured, and substrates with overlarge film edge distances can be screened out. The method comprises steps as follows: a to-be-measured substrate comprising a substrate, a test pattern and a protective film layer is prepared; the outer edge of the test pattern is aligned to the edge of the substrate, the protective film layer overlaps with the test pattern or the edge is aligned to the inner edge of the test pattern; the to-be-measured substrate is scanned with test light rays along a test path, reflected test light rays are received, the spectrum corresponding to each point is acquired, the test path passes through the test pattern, one end point is located on the substrate edge where the test pattern is located; the absorption degree of the protective film layer to the test light rays is higher than that of the test pattern to the test light rays; the point corresponding to the spectrum where the absorption peak appears is determined, and the vertical distance between the point and the substrate edge where the test pattern is located is the film edge distance. The measuring method is used for screening out the substrates with overlarge film edge distances.

Description

technical field [0001] The invention relates to the technical field of manufacturing liquid crystal display devices, in particular to a film margin measurement method and a measurement device. Background technique [0002] In the TFT-LCD (Thin film transistor liquid crystal display, thin film transistor liquid crystal display) production line, a protective film layer that completely covers the metal pattern needs to be deposited on the glass substrate to protect the metal pattern. [0003] Such as figure 1 As shown, a shield frame 1 with a fixed position and width is provided in the process chamber for forming a film on a glass substrate, wherein, there is a hollowed out area in the middle of the shield frame 1, and the area of ​​the hollowed out area is smaller than the area of ​​the glass substrate 2, and the hollowed out area corresponds to The area to be filmed on the glass substrate 2 . When the glass substrate 2 is conveyed under the shielding plate frame 1, the rela...

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Problems solved by technology

[0004] But in practice, if figure 2 As shown, when the glass substrate 2 is conveyed under the shielding plate frame 1, the relative position of the glass substrate 2 and the shielding plate frame 1 may be shifted, which will cause the film edge on one side of the formed protective film layer to be in contact with the glass substrate 2. The distance between the edges (hereinafter referred to as the distance between the film edge of the protective film layer and the edge of the glass substrate 2 is the film edge distance) is too large

When the film margin is too large, there will be two problems: on the one hand, some areas of the metal pattern are not covered by the protective film layer, resulting in adverse effects on the metal pattern in the subsequent exposure and etching processes; on the other hand, due to the The designable range of the product depends on the size of the area of ​​the metal pattern covered by the protective film layer. Therefore, if the film margin is too large, the designable range of the product will be reduced

However, the protective film layer formed on the glass substrate generally uses SiN x (silicon nitride) thin film or SiO 2 (Silicon dioxide) thin film, SiN x Thin films and SiO 2 The film quality is transparent, it is difficult to determine the distance from the film edge of the protective film layer to the edge of the glass substrate

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