TW201350908A - Multi-focal optical alignment apparatus and alignment method for multiple stacking substrates - Google Patents

Abstract

A multi-focal optical alignment apparatus for aligning multiple stacking substrates is provided. Each of the substrates has an alignment mark. The multi-focal optical alignment apparatus includes a plurality of image sensors for receiving an alignment image of the alignment mark of each substrate, and a beam splitter for transmitting the alignment image of each alignment mark to each image sensor, respectively. Each image sensor has a different focus. The beam splitter has a light incident surface and a plurality of light exiting surfaces, where the substrates face the light incident surface of the beam splitter, and each image sensor faces the light exiting surface of the beam splitter, respectively.

Description

Multi-focus optical alignment device and alignment method of multiple stacked substrates

The invention relates to an optical alignment device and a aligning method thereof, in particular to a multi-focus optical alignment device and a method for aligning a plurality of stacked substrates by using a multi-focus optical alignment device.

The display panel is mainly composed of two substrates and a display medium layer disposed therein. For example, the liquid crystal display panel is mainly composed of an array substrate, a color filter substrate, and a liquid crystal layer. In addition, in the current development of display technology, stereoscopic display and touch input have two major trends. In order to provide a stereoscopic display function or a touch input function of the display panel, the display panel must be combined with the stereoscopic display substrate or the touch substrate. It can be seen from the above that whether it is a display panel, a stereoscopic display panel or a touch display panel, it is necessary to face the alignment problem between two or more substrates during the assembly process. In general, the alignment of each substrate is performed by pre-aligning the alignment marks on the respective substrates, that is, the image sensing elements are used to receive the alignment images of the alignment marks of the substrate, and then the substrates are adjusted. The relative position to complete the alignment. When performing high-precision alignment, it is necessary to use a high-magnification lens to generate a aligning image. However, since the high-magnification lens has a shallow depth of field, it is impossible to simultaneously observe the alignment marks of different substrates, so that the alignment accuracy cannot be improved. .

One of the objects of the present invention is to provide a multi-focal optical alignment device and a method for aligning a plurality of stacked substrates to improve the alignment accuracy of the substrate.

A preferred embodiment of the present invention provides a multifocal optical alignment device for aligning a plurality of stacked substrates, each having a pair of bit marks. The multi-focus optical alignment device includes a plurality of image sensing units for receiving a pair of alignment images of the alignment marks on the substrates, and a beam splitter for transmitting the alignment images of the alignment marks to the respective images. Sensing unit. Each image sensing unit has a different focal length. The beam splitter has a light-incident surface and a plurality of light-emitting surfaces, and the substrate faces the light-incident surface of the beam splitter, and each of the image sensing units respectively faces the light-emitting surface of the beam splitter.

Another preferred embodiment of the present invention provides a method for aligning a plurality of stacked substrates, comprising the following steps. The multifocal optical alignment device described above is provided. Place the substrate in front of the light entering the splitter. The alignment marks of the substrate are respectively located at a focus of the corresponding image sensing unit. The relative position of the substrate is adjusted according to the image received by the image sensing unit to perform alignment.

The present invention will be further understood by those of ordinary skill in the art to which the present invention pertains. .

Please refer to Figure 1. Figure 1 is a diagram showing the multiple focal lengths of the first preferred embodiment of the present invention. Schematic diagram of an optical alignment device. As shown in FIG. 1 , the multi-focus optical alignment device 10 of the present embodiment is used for aligning a plurality of stacked substrates, and the embodiment is based on two stacked substrates 1 and 2, but the substrate is The number is not limited to this. The substrates 1, 2 have a pair of bit marks 1A, 2A, respectively, and the alignment marks 1A, 2A are located on different planes. The multifocal optical alignment device 10 includes a plurality of image sensing units 11, 12, and a beam splitter 20. The number of image sensing units is the same as the number of substrates to be aligned, so two image sensing units 11, 12 are used in this embodiment. The image sensing units 11 and 12 are respectively configured to receive the alignment images 1M and 2M of the alignment marks 1A and 2A on the substrates 1 and 2, and the image sensing units 11 and 12 have different focal lengths. The beam splitter 20 is configured to transmit the alignment images 1M, 2M of the alignment marks 1A, 2A to the image sensing units 11, 12, respectively. In this embodiment, the beam splitter 20 is a polarization beam splitter (PBS), which can be split according to the polarization direction of the light. For example, the S-polarized light and the P-polarized light are distinguished in different directions. sold out. The beam splitter 20 is not limited to a polarizing beam splitter but may be other various types of beamsplitters. The beam splitter 20 has a light incident surface 20S and a plurality of light emitting surfaces 20A and 20B. The substrates 1 and 2 face the light incident surface 20S of the optical splitter 20, and the substrate 1 is closer to the optical splitter 20, and the substrate 2 is farther away from the splitting light. 20. In addition, the image sensing units 11 and 12 face the light emitting surfaces 20A and 20B of the beam splitter 20, respectively.

In this embodiment, the image sensing unit 11 includes an image sensing component 11A for receiving the alignment image 1M of the corresponding alignment mark 1A of the substrate 1 , and a focal length adjusting component 11F for providing a focal length to correspond to The alignment image 1M is imaged on the image sensing component 11A; the image sensing unit 12 includes an image sensing component 12A for receiving the pair The alignment image 2M of the alignment mark 2A of the substrate 2 and a focal length adjustment component 12F are used to provide another different focal length to image the corresponding alignment image 2M to the image sensing element 12A. The image sensing element 11A and the image sensing element 12A may respectively include a complementary metal oxide semiconductor sensing element (CMOS sensor) or a charge coupled sensing element (CCD sensor), but not limited thereto. Various types of sensing elements. The focus adjusting elements 11F, 12F may be high-magnification lenses, and the focus adjusting elements 11F, 12F may respectively include an optical fixed focus lens, or a zoom lens such as an optical zoom lens or a liquid crystal lens.

Please refer to Figure 2 again and refer to Figure 1 together. 2 is a flow chart showing a method of aligning a plurality of stacked substrates of a preferred embodiment of the present invention. As shown in FIG. 2, the alignment method of the plurality of stacked substrates of the present invention includes the following steps: Step 30: providing the multifocal optical alignment device 10 of FIG. 1; Step 32: placing the substrates 1 and 2 on Step 34: aligning the alignment marks 1A and 2A of the substrates 1 and 2 at the focal points of the corresponding image sensing units 11 and 12; and step 36: according to the image sensing unit 11 The received images 1M and 2M are adjusted to the relative positions of the substrates 1 and 2 for alignment.

In the aligning method of the plurality of stacked substrates, in the step 34, the alignment marks 1A and 2A of the substrates 1 and 2 are respectively located at the focal points of the corresponding image sensing units 11 and 12. The way to achieve it. For example, if the focus adjustment elements 11F, 12F are optical fixed focus lenses, the position of the substrates 1 and 2 can be adjusted. The alignment marks 1A, 2A of the substrates 1, 2 are respectively placed at the focal points of the corresponding image sensing units 11, 12. If the focus adjustment elements 11F and 12F are zoom lenses, the alignment marks 1A and 2A of the substrates 1 and 2 can be respectively located in the corresponding image sensing units 11 and 12 by adjusting the focal lengths of the image sensing units 11 and 12. Focus on it.

As shown in FIG. 1 , when the alignment marks 1A and 2A of the substrates 1 and 2 are respectively located at the focal points of the corresponding image sensing units 11 and 12, the light of the alignment mark 1A is generated after passing through the beam splitter 20. The alignment image 1M, 1M', and since the alignment mark 1A of the substrate 1 is located at the focus of the image sensing unit 11, the alignment image 1M of the alignment mark 1A is imaged on the image sensing unit 11, and the substrate is The alignment mark 1A of 1 is not located at the focus of the image sensing unit 12, so the alignment image 1M' of the registration mark 1A is not imaged in the image sensing unit 12; similarly, the light of the alignment mark 2A is split. After the device 20, two alignment images 2M, 2M' are generated, and since the alignment mark 2A of the substrate 2 is located at the focus of the image sensing unit 12, the alignment image 2M of the alignment mark 2A is imaged in the image sense. The unit 12 is measured, and since the alignment mark 2A of the substrate 2 is not located at the focus of the image sensing unit 11, the alignment image 2M' of the registration mark 2A is not imaged in the image sensing unit 11. After determining the positions of the substrates 1, 2, the relative positions of the substrates 1, 2 can be adjusted so that the substrates 1, 2 can be accurately aligned.

The multifocal optical alignment device of the present invention is not limited to the above embodiment. The multi-focus optical alignment device of other preferred embodiments of the present invention will be sequentially described below, and the same symbols are used to mark the same in the following embodiments in order to facilitate the comparison of the differences of the embodiments and simplify the description. Components, and mainly for the differences between the various embodiments Ming, and no longer repeat the repetitive part.

Please refer to Figure 3. FIG. 3 is a schematic view showing a multifocal optical alignment device according to a second preferred embodiment of the present invention. As shown in FIG. 3, unlike the first preferred embodiment, the multifocal optical alignment device 50 of the present embodiment includes three image sensing units 11, 12, 13, and a beam splitter 20 for The substrate is aligned. The image sensing units 11, 12, 13 respectively include an image sensing component 11A, 12A, 13A for receiving a registration image of the alignment mark of the corresponding substrate, and a focus adjustment component 11F, 12F, 13F for providing a The focal length causes the corresponding alignment image to be imaged on the image sensing elements 11A, 12A, 13A. The beam splitter 20 is configured to transmit the alignment images of the alignment marks of different substrates to the image sensing units 11, 12, and 13, respectively. The beam splitter 20 can be a splitter, which can respectively transmit the alignment images of the alignment marks on the three substrates (not shown) to the corresponding image sensing units 11, 12, 13. For example, in the implementation side, the beam splitter 20 is an X cube, but not limited thereto can be other various types of beamsplitters. The beam splitter 20 has a light incident surface 20S and three light exiting surfaces 20A, 20B, 20C, wherein the substrates are stacked on each other and face the light incident surface 20S of the beam splitter 20. Further, the image sensing units 11, 12, and 13 face the light-emitting surfaces 20A, 20B, and 20C of the beam splitter 20, respectively. Since the alignment marks of different substrates are respectively located at the focus of the image sensing units 11, 12, 13, when the alignment is performed, the image sensing units 11, 12, 13 only receive the alignment of the corresponding substrates. The alignment image of the mark, thereby determining the relative position of the three substrates. After determining the position of the three substrates, the relative positions of the three substrates can be adjusted for precise alignment.

Please refer to Figure 4. FIG. 4 is a schematic view showing a multifocal optical alignment device according to a third preferred embodiment of the present invention. As shown in FIG. 4, unlike the first and second preferred embodiments, the multifocal optical alignment device 60 of the present embodiment includes five image sensing units 11, 12, 13, 14, 15 and a split light. The device 20 is for aligning five substrates (not shown). The image sensing units 11, 12, 13, 14, 15 respectively include an image sensing component 11A, 12A, 13A, 14A, 15A for receiving a registration image of the alignment mark of the corresponding substrate, and a focal length adjusting component 11F 12F, 13F, 14F, 15F are used to provide a focal length to image the corresponding alignment image to the image sensing elements 11A, 12A, 13A, 14A, 15A. The beam splitter 20 is configured to transmit the alignment images of the alignment marks of different substrates to the image sensing units 11, 12, 13, 14, and 15, respectively. The beam splitter 20 can be a splitter that can respectively transmit the alignment images of the alignment marks on the five substrates to the corresponding image sensing units 11, 12, 13, 14, 15. For example, in the implementation side, the beam splitter 20 can be a hexagonal polarized light splitter, but not limited thereto can be other various types of splitters. The beam splitter 20 has a light incident surface 20S and five light exiting surfaces 20A, 20B, 20C, 20D, and 20E, wherein the substrates are stacked on each other and face the light incident surface 20S of the optical splitter 20. Further, the image sensing units 11, 12, 13, 14, 15 face the light-emitting surfaces 20A, 20B, 20C, 20D, 20E of the beam splitter 20, respectively. Since the alignment marks of different substrates are respectively located at the focus of the image sensing units 11, 12, 13, 14, 15, the image sensing units 11, 12, 13, 14, 15 only The alignment image of the alignment mark of the corresponding substrate is received, thereby determining the relative positions of the five substrates. After determining the position of the five substrates, the relative positions of the five substrates can be adjusted for precise alignment.

The multifocal optical alignment device of the present invention is used for aligning a plurality of stacked substrates, and can be applied to various types of panels having a stacked substrate structure, such as a display panel, a stereoscopic display panel, and a touch display panel. It should be noted that the number of image sensing units of the multi-focus optical alignment device and the number of light-emitting surfaces of the optical splitter can be adjusted according to the number of substrates to be aligned, and are not limited to those disclosed in the above embodiments.

In summary, the multi-focus optical alignment device of the present invention uses a plurality of image sensing units and aligns the plurality of substrates with the optical splitter. Since the focal lengths of the image sensing units are different, the corresponding substrate can be accepted. The alignment image of the alignment mark for accurate alignment.

The above are only the preferred embodiments of the present invention, and all changes and modifications made to the scope of the present invention should be within the scope of the present invention.

10‧‧‧Multifocal optical alignment device

1, 2‧‧‧ substrate

1A, 2A‧‧‧ alignment mark

11, 12‧‧‧ image sensing unit

1M, 2M‧‧‧ alignment image

1M’, 2M’‧‧‧ alignment image

20‧‧‧Distributor

20S‧‧‧Glossy

20A, 20B‧‧‧ shiny surface

11F, 12F‧‧‧focal length adjustment components

11A, 12A‧‧‧ image sensing components

50‧‧‧Multifocal optical alignment device

13‧‧‧Image sensing unit

13A‧‧‧Image sensing components

13F‧‧•focal length adjustment component

20C‧‧‧Glossy

60‧‧‧Multifocal optical alignment device

14, 15‧‧‧ image sensing unit

14A, 15A‧‧‧ image sensing components

14F, 15F‧‧‧focal length adjustment components

20D, 20E‧‧‧ shiny surface

30‧‧‧Steps

32‧‧‧Steps

34‧‧‧Steps

36‧‧‧Steps

1 is a schematic view of a multifocal optical alignment device according to a first preferred embodiment of the present invention.

2 is a flow chart showing a method of aligning a plurality of stacked substrates of a preferred embodiment of the present invention.

FIG. 3 is a schematic view showing a multifocal optical alignment device according to a second preferred embodiment of the present invention.

FIG. 4 is a schematic view showing a multifocal optical alignment device according to a third preferred embodiment of the present invention.

10‧‧‧Multifocal optical alignment device

1, 2‧‧‧ substrate

1A, 2A‧‧‧ alignment mark

11, 12‧‧‧ image sensing unit

1M, 2M‧‧‧ alignment image

1M’, 2M’‧‧‧ alignment image

20‧‧‧Distributor

20S‧‧‧Glossy

20A, 20B‧‧‧ shiny surface

11F, 12F‧‧‧focal length adjustment components

11A, 12A‧‧‧ image sensing components

Claims (10)

A multi-focus optical alignment device for aligning a plurality of stacked substrates, each of the substrates having a pair of bit marks, the multi-focus optical alignment device comprising: a plurality of image sensing units for receiving One of the alignment marks on the substrate, wherein each of the image sensing units has a different focal length; and a beam splitter for transmitting the alignment images of the alignment marks to the respective ones An image sensing unit, wherein the beam splitter has a light incident surface and a plurality of light emitting surfaces, wherein the substrate faces the light incident surface of the light splitter, and each of the image sensing units respectively faces the light output of the light splitter surface. The multi-focus optical alignment device of claim 1, wherein each of the image sensing units includes an image sensing component for receiving the alignment image of the alignment mark corresponding to the substrate, and a focus adjustment component The focal length is used to image the corresponding alignment image to the image sensing element. The multifocal optical alignment device of claim 2, wherein each of the focus adjustment elements comprises an optical focus lens. The multifocal optical alignment device of claim 2, wherein each of the focus adjustment elements comprises a zoom lens. The multifocal optical alignment device of claim 4, wherein each of the focus adjustment elements comprises an optical zoom lens or a liquid crystal lens. The multifocal optical alignment device of claim 1, wherein the beam splitter comprises a polarizing beam splitter or a beam splitter. The multifocal optical alignment device of claim 2, wherein each of the image sensing elements comprises a complementary metal oxide semiconductor sensing element or a charge coupled sensing element. A method for aligning a plurality of stacked substrates, comprising: providing the multi-focus optical alignment device of claim 1; placing the substrates in front of the light entering the optical splitter; The alignment marks are respectively located at a focus of the corresponding image sensing unit; and the relative positions of the substrates are adjusted according to the alignment images received by the image sensing units for alignment. The method for aligning a plurality of stacked substrates according to claim 8, wherein the step of respectively positioning the alignment marks of the respective substrates on the focus of the corresponding image sensing unit comprises adjusting positions of the substrates. The method for aligning a plurality of stacked substrates according to claim 8, wherein the step of respectively positioning the alignment marks of the respective substrates on the focus of the corresponding image sensing unit comprises adjusting the image sensing units The focal length.