Inspection apparatus and inspection method using the same

Patent metadata

Field	Value
Publication number	US-2018188189-A1
Application number	US-201715703541-A
Country	US
Kind code	A1
Filing date	Sep 13, 2017
Priority date	Dec 29, 2016
Publication date	Jul 5, 2018
Grant date	—

Abstract

Disclosed herein is a method for inspecting a transparent film. The method comprises irradiating an inspection target with light using a polarizer, receiving light that is reflected by the inspection target and passes through an analyzer by a line scan camera, synthesizing an amplitude and a phase of wavelength of the light into an intensity of light, comparing the intensity of the light with predetermined intensities of light for inspection targets having different thicknesses; and detecting a defect of the inspection target based on the compared intensity with the predetermined intensities. It can be determined whether there is a transparent film, and the thickness of the transparent film can be measured in a large area. The inspection is carried out in real-time after the transparent film is formed, such that if a defect is generated, it can be fed back immediately to thereby reduce defects. In this case, the processing cost can be saved.

First claim

What is claimed is:

1 . An inspection method comprising:
irradiating an inspection target with light using a polarizer; receiving reflective light that is reflected by the inspection target and passes through an analyzer by a line scan camera; synthesizing an amplitude and a phase of wavelength of the reflective light into an intensity of light; comparing the intensity of the light with predetermined intensities of light for inspection targets having different thicknesses; and detecting a defect of the inspection target based on the compared intensity with the predetermined intensities.

2 . The method of claim 1 , wherein the comparing the intensity of the light with predetermined intensities of light is carried out while a new inspection area of the inspection target is scanned.

3 . The method of claim 1 , wherein the inspection target is a transparent film on an organic light emitting panel, and
wherein the comparing the intensity of the light with predetermined intensities of light includes detecting existence of the transparent film and measuring a thickness of the transparent film.

4 . The method of claim 3 , wherein the detecting existence of the transparent film comprises detecting whether the transparent film is formed in at least one of a bending area of the organic light emitting panel, a pad of the organic light emitting panel or a scribing line on a substrate of the organic light emitting panel.

5 . The method of claim 4 , wherein the detecting existence of the transparent film comprises comparing an intensity of a metal key covered by the transparent film with an intensity of a metal key not covered by the transparent film among a plurality of metal keys disposed on the inspection target.

6 . The method of claim 3 , wherein the measuring the thickness of the transparent film comprises measuring the thickness of the transparent film deposited on a test pattern disposed on the organic light emitting panel.

7 . An inspection apparatus comprising:
a polarizer linearly polarizing light emitted from a light source; an analyzer allowing the light reflected by an inspection target that passes through the polarizer to transmit; an optical inspection unit including a line scan camera that receives the light transmitted the analyzer and synthesizes an amplitude and a phase of wavelength of the reflected light into an intensity of light; and a detection unit comparing the intensity of the light with predetermined intensities of light for inspection targets having different thicknesses and detecting a defect of the inspection target based on results of the comparing.

8 . The apparatus of claim 7 , further comprising a first beam splitter that separates the linearly polarized light so that it is incident on the inspection target.

9 . The apparatus of claim 8 , further comprising a second beam splitter including a half-mirror reducing an amount of the light transmitted through the analyzer to 50%.

10 . The apparatus of claim 8 , wherein the first beam splitter includes a half-mirror.

11 . The apparatus of claim 7 , wherein the light emitted from the light source has a wavelength of 400 to 800 nm.

12 . The apparatus of claim 7 , further comprising an alignment camera configured to align the inspection target with the optical inspection unit.

13 . The apparatus of claim 7 , further comprising an auto focusing unit automatically adjusting focus of the optical inspection unit with respect to the inspection target when the optical inspection unit moves along an inspection area of the inspection target.

14 . The apparatus of claim 9 , wherein the optical inspection unit further comprises an auxiliary camera configured to align a scan area in order to scan the inspection area of the inspection target.

15 . The apparatus of claim 14 , wherein the auxiliary camera receives 50% of the light passed through the second beam splitter while the line scan camera receives the other 50% of the light passes through the second beam splitter.

16 . The apparatus of claim 7 , wherein the inspection target includes a transparent film disposed in a cell for an organic light emitting panel.

17 . The apparatus of claim 16 , wherein the transparent film includes a silicon or acrylic material.

18 . The apparatus of claim 7 , wherein the line scan camera observes an area of 8 mm by 8 mm at a time while moving.

19 . The apparatus of claim 18 , wherein the line scan camera inspects existence of the inspection target and measuring a thickness of the inspection target.

20 . The apparatus of claim 9 , wherein the optical inspection unit further comprises a lens barrel accommodating a plurality of lenses adjusting an optical path and the light source.

Assignees

• Lg Display Co Ltd

Inventors

• Hwang Seokju

Classifications

• G01B11/0625

  with measurement of absorption or reflection · CPC title

• G01N2021/8433

  Comparing coated/uncoated parts · CPC title

• G01N2021/8427

  Coatings · CPC title

• G01B11/0641

  with measurement of polarization · CPC title

• G01N2021/8848

  Polarisation of light · CPC title