JP2015060493A - Pattern inspection apparatus and pattern inspection method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pattern inspection apparatus and the like, by which patterns formed on top and back surfaces of a transparent substrate can be inspected with high accuracy.SOLUTION: A pattern inspection apparatus is adapted for inspection of appearances of wiring patterns 23, 25 formed on top and back surfaces of a transparent film 11, and the apparatus includes: an imaging unit for imaging inspection light that is transmitted through the transparent film 11; and an image processing unit for carrying out inspection by determining whether or not the wiring patterns 23, 25 are acceptable by using an image acquired by the imaging unit. On the transparent film 11, positioning marks 27, 29 in different shapes are formed respectively corresponding to the wiring patterns 23, 25; and the image processing unit aligns a reference pattern 43 by referring the mark 27 on the image, sets the region of the reference pattern 43 as an inspection region of the wiring pattern 23, and aligns the reference pattern by referring the mark 29 on the image, and sets the region of the reference pattern as an inspection region of the wiring pattern 25.

Description

  The present invention relates to a pattern inspection apparatus for inspecting patterns such as wiring formed on the front and back of a transparent base material.

  When a pattern such as wiring formed on a substrate is imaged and pattern appearance inspection is performed based on the image, in order to determine the quality of the pattern by performing image processing or the like, the inspection area in the image is referred to as the pattern area. It is necessary to determine precisely to correspond.

  In Patent Document 1, in a wiring pattern such as a film substrate or a hard substrate, an input image obtained by imaging a pattern to be inspected is corrected based on data on a positional deviation amount of a reference position mark given to the pattern to be inspected. It is described that the quality is determined by comparing with a reference image.

JP-A-3-6673

  However, when a pattern is formed on the front and back of a transparent substrate such as a transparent film, both the front and back patterns appear in the image. When inspecting such front and back patterns, if the inspection areas for both patterns on the image are set together, the inspection will be performed if there is a deviation in the positional relationship between the front and back patterns (which is not a problem for the product). The position of the area and the pattern may be misaligned, which may cause erroneous detection of errors.

  The present invention has been made in view of the above-described problems, and an object thereof is to provide a pattern inspection apparatus and the like that can accurately inspect a pattern formed on the front and back of a transparent substrate.

  1st invention for achieving the objective mentioned above is a pattern inspection apparatus which inspects the appearance of the front pattern and back pattern formed in the front and back of a transparent base material, and is an image pick-up part which picturizes the base material, An image processing unit that performs inspection by determining pass / fail of the front pattern and the back pattern using an image captured by the image pickup unit, and the base material includes the front pattern and the back pattern. Corresponding to each, a front mark and a back mark for alignment with different forms are formed, and the image processing unit includes front pattern data including a front reference pattern indicating the front pattern area, and the back pattern area. Back surface data including a back reference pattern to be stored, aligning the front reference pattern using the front mark on the image, and aligning the front reference pattern area with the front pattern Pattern inspection apparatus, wherein the back reference pattern is aligned using the back mark on the image, and the back reference pattern area is set as the back pattern inspection area. It is.

  According to the first invention, the front and back pattern inspection areas can be set by aligning the front and back reference patterns using the marks on the substrate. Thus, the front and back patterns can be inspected independently, and even when the positional relationship between the front and back patterns is deviated as described above, erroneous detection of errors due to this misalignment is prevented, and highly accurate pattern inspection is performed. It becomes possible.

It is desirable that the front mark and the back mark have different shapes.
Thereby, each mark can be easily identified, and the front and back reference patterns can be accurately aligned.

It is desirable that the imaging unit captures light that has been applied to the base material and transmitted through the base material.
By performing imaging with a transmission optical system, the contrast between the pattern portion and the other substrate portion is increased, which is suitable for inspection by image processing or the like. However, since the front and back patterns appear on the image with substantially the same brightness and cannot be distinguished by a threshold or the like, the effect of being able to inspect the front and back patterns independently by the method of the present invention is particularly great.

The front pattern data includes a front mark pattern corresponding to the front mark, the back pattern data includes a back mark pattern corresponding to the back mark, and the image processing unit includes the front mark pattern and the image The front reference pattern is aligned by aligning the front mark on the top, and the front reference pattern is aligned by aligning the back mark pattern and the back mark on the image. It is desirable to do.
By aligning the positions of the marks and mark patterns on the image in this way, the alignment of the front and back reference patterns can be performed with high accuracy.

  A second invention is a pattern inspection method for inspecting the appearance of a front pattern and a back pattern formed on the front and back of a transparent base material, wherein an imaging step in which the imaging unit images the base material, and an image processing unit includes And an inspection step for performing inspection by determining pass / fail of the front pattern and the back pattern using an image picked up by the image pickup unit, and the substrate includes the front pattern and the back pattern. Corresponding to each, a front mark and a back mark for alignment with different forms are formed, and the image processing unit includes front pattern data including a front reference pattern indicating the front pattern area, and the back pattern area. Back pattern data including a back reference pattern to be displayed, and in the inspection step, the image processing unit aligns the front reference pattern using the front mark on the image. The front reference pattern region is set as the front pattern inspection region, the back reference pattern is aligned using the back mark on the image, and the back reference pattern region is aligned with the back pattern. It is a pattern inspection method characterized by being set as an inspection region.

  According to the present invention, it is possible to provide a pattern inspection apparatus or the like that can accurately inspect a pattern formed on the front and back of a transparent substrate.

The figure which shows the pattern inspection apparatus 1 The figure which shows the hardware constitutions of the image process part 17. The figure which shows the transparent film 11 Flow chart showing procedure of pattern inspection method Diagram explaining pattern inspection method Diagram explaining pattern inspection method The figure which shows the transparent film 11 and pattern data 41a and 42a Diagram explaining pattern inspection method

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[First Embodiment]
(1. Pattern inspection device 1)
FIG. 1 is a diagram showing a configuration of a pattern inspection apparatus 1 according to the first embodiment of the present invention.

  The pattern inspection apparatus 1 performs an appearance inspection of these patterns on the transparent film 11 which is a transparent base material having a pattern formed on the front and back sides, and includes an irradiation unit 13, an imaging unit 15, an image processing unit 17, and the like. Have.

  The transparent film 11 is a film for transparent electrodes of touch panels such as smartphones and tablet terminals, and is formed of a resin such as PET (polyethylene terephthalate). On the front and back surfaces of the transparent film 11, wiring patterns 23 and 25 made of a conductive metal thin film or the like are formed. For the formation of the wiring patterns 23 and 25, techniques such as vapor deposition and etching are used. Details of the transparent film 11 will be described later.

  The irradiation unit 13 irradiates the transparent film 11 with inspection light. For example, a light source such as an LED light source is used.

  The imaging unit 15 receives inspection light transmitted through the transparent film 11 and images the transparent film 11, and includes an imaging device such as a CCD (Charge Coupled Device) camera. The imaging unit 15 is connected to the image processing unit 17, and an image obtained by imaging the transparent film 11 is transmitted to the image processing unit 17.

  The image processing unit 17 performs image processing on the image captured by the imaging unit 15, determines whether the wiring patterns 23 and 25 are good, and performs an inspection.

  FIG. 2 is a diagram illustrating a hardware configuration of the image processing unit 17. As shown in FIG. 2, the image processing unit 17 includes, for example, a control unit 31, a storage unit 32, a media input / output unit 33, a communication control unit 34, an input unit 35, a display unit 36, and a peripheral device I / F (interface). The unit 37 and the like can be realized by a computer connected via a bus 38.

The control unit 31 includes a CPU, a ROM, a RAM, and the like.
The CPU calls a program stored in the storage unit 32, ROM, recording medium or the like to a work memory area on the RAM and executes it, drives and controls each unit connected via the bus 38, and executes processing described later. . The ROM is a non-volatile memory and permanently holds programs such as a boot program and BIOS, data, and the like. The RAM is a volatile memory, and temporarily stores a program, data, and the like loaded from the storage unit 32, ROM, recording medium, and the like, and includes a work area used by the control unit 31 for performing various processes.

  The storage unit 32 is a hard disk drive or the like, and stores a program executed by the control unit 31, data necessary for program execution, an OS, and the like. These programs and data are read by the control unit 31 as necessary, transferred to the RAM, and executed. In the present embodiment, pattern data for setting an inspection region on the image is stored in the storage unit 32. The pattern data will be described later.

The media input / output unit 33 inputs and outputs data, and includes a media input / output device such as a CD drive or a DVD drive.
The communication control unit 34 includes a communication control device, a communication port, and the like, and performs communication control with other devices via a network.
The input unit 35 includes, for example, a keyboard, a pointing device such as a mouse, and an input device such as a numeric keypad.

The display unit 36 is a display device such as a CRT monitor or a liquid crystal panel.
The peripheral device I / F unit 37 is a port for connecting peripheral devices. The connection form with the peripheral device may be wired or wireless.
The bus 38 is a path that mediates transmission / reception of control signals, data signals, and the like between the respective units.

(2. Transparent film 11)
FIG. 3 is a diagram illustrating the transparent film 11, which is an example of an image obtained by imaging the transparent film 11 with the imaging unit 15.

  As shown in FIG. 3, on the surface of the transparent film 11, a wiring pattern 23 (front pattern) and an alignment mark 27 (front mark) corresponding to the wiring pattern 23 are formed. On the back surface, a wiring pattern 25 (back pattern) and an alignment mark 29 (back mark) corresponding to the wiring pattern 25 are formed. The marks 27 and 29 are formed simultaneously with the formation of the wiring patterns 23 and 25, respectively. On the image, these wiring patterns 23 and 25 and marks 27 and 29 appear as low luminance portions.

  The marks 27 and 29 are formed on the sides of the wiring patterns 23 and 25, and the shapes thereof are different from each other. In the example of the figure, the mark 27 has a shape in which the T-shape is tilted to the left, and the mark 29 has a shape in which the mark 27 is reversed left and right. The distance between the mark 27 and the side of the wiring pattern 23 and the distance between the mark 29 and the side of the wiring pattern 25 are respectively set to predetermined values.

(3. Pattern inspection method)
Next, the procedure of the pattern inspection method by the pattern inspection apparatus 1 will be described with reference to FIG. FIG. 4 is a flowchart showing the procedure of the pattern inspection method.

  In the present embodiment, while transporting the transparent film 11, the inspection unit irradiates the inspection film with the inspection light from the irradiation unit 13 at a predetermined timing, and receives the inspection light transmitted through the transparent film 11 with the imaging unit 15. Imaging of the transparent film 11 is performed (S101). The captured image is sent to the image processing unit 17.

  The control unit 31 of the image processing unit 17 displays the above image on the display unit 36 and sets the inspection area of the wiring pattern 23 on the image (S102).

  In S102, first, pattern data stored in the storage unit 32 is read for setting the inspection area. FIG. 5A shows the pattern data 41 (table pattern data).

  As shown in FIG. 5A, the pattern data 41 includes a reference pattern 43 (table reference pattern) and a mark pattern 47 (table mark pattern).

The reference pattern 43 indicates an inspection area on the image and corresponds to the area of the wiring pattern 23.
The mark pattern 47 corresponds to the mark 27 in position and shape. The positional relationship between the mark pattern 47 and the reference pattern 43 is determined so as to correspond to the positional relationship between the mark 27 and the wiring pattern 23.

  In S102, the image processing unit 17 aligns the mark 27 on the image and the mark pattern 47 of the pattern data 41 as shown in FIG. Is set in the inspection area of the wiring pattern 23 in FIG.

  Returning to the description of FIG. After setting the inspection region as described above, the control unit 31 of the image processing unit 17 cuts out the inspection region (reference pattern 43) as shown in FIG. 5C and performs image processing or the like on the wiring pattern 23. Then, the wiring pattern 23 is inspected (S103).

  In S103, for example, the line width of the wiring pattern 23 is calculated and a reference value is compared, or a missing or missing portion of the wiring pattern 23 is detected to determine whether the wiring pattern 23 is good or bad. These inspections can be performed using known image processing techniques. In addition, it may be determined whether the predetermined template image matches the wiring pattern 23 or not. In this case, the template image itself may also serve as the reference pattern 23.

  The control unit 31 of the image processing unit 17 performs the same process on the wiring pattern 25 of the transparent film 11. That is, the image processing unit 17 first reads the pattern data 42 (back pattern data) shown in FIG. The pattern data 42 includes a reference pattern 45 (back reference pattern) and a mark pattern 49 (back mark pattern).

  Similar to the above, the reference pattern 45 indicates the inspection area on the image and corresponds to the area of the wiring pattern 25. The mark pattern 49 corresponds to the mark 29 in position and shape. The positional relationship between the mark pattern 49 and the reference pattern 45 is determined so as to correspond to the positional relationship between the mark 29 and the wiring pattern 25.

  The control unit 31 of the image processing unit 17 aligns the mark 29 on the image and the mark pattern 49 of the pattern data 42 as shown in FIG. Is set in the inspection area of the wiring pattern 25 (S104). Then, as shown in FIG. 6C, the inspection region (reference pattern 45) is cut out, the image processing or the like is performed on the wiring pattern 25 in the same manner as described above, and the quality is determined, and the wiring pattern 25 is inspected (S105). .

  As described above, according to this embodiment, the reference patterns 43 and 45 are aligned using the marks 27 and 29 on the transparent film 11 to set the inspection areas of the wiring patterns 23 and 25, respectively. As a result, the wiring patterns 23 and 25 can be inspected independently. For example, even when the positional relationship between the wiring patterns 23 and 25 is deviated as described above, erroneous detection of errors due to this misregistration is prevented. High wiring patterns 23 and 25 can be inspected.

  In the present embodiment, the mark 27 formed on the transparent film 11 has a shape in which the T-shape is tilted to the left, and the mark 29 has a shape in which the mark 27 is horizontally reversed. However, the present invention is not limited to this.

  Furthermore, the marks 27 and 29 may be different in form, and are not limited to the difference in shape. In addition to the shape, a difference in transmittance is also conceivable as a difference in form. In this case, the marks 27 and 29 can be identified as a difference in luminance on the image. In any case, it is sufficient that the difference between the marks 27 and 29 can be identified. However, if the shapes are different as in the present embodiment, the marks 27 and 29 can be easily identified.

  Further, in the present embodiment, the inspection by the transmission optical system is performed. However, even when the inspection by the reflection optical system in which the reflected light from the wiring pattern of the transparent film 11 is imaged by the imaging unit 15, the wiring on the front and back of the transparent film 11 is performed. Since the patterns 23 and 25 appear on the image, the same processing can be applied. In this case, as the difference in the form of the marks 27 and 29, a difference in reflectance and color in addition to the shape may be considered.

  However, as in this embodiment, imaging with a transmission optical system increases the contrast between the portions of the wiring patterns 23 and 25 and the other substrate portions, which is suitable for inspection by image processing or the like. In addition, when imaging is performed with a reflective optical system, the brightness of the wiring patterns 23 and 25 on the front and back sides is slightly different. Therefore, it is possible to distinguish the wiring patterns 23 and 25 by a threshold value. When the image is picked up in (1), the wiring patterns 23 and 25 appear with almost the same luminance on the image, so that they cannot be distinguished by a threshold or the like. From such a point, the effect that the wiring patterns 23 and 25 can be inspected independently by using the method of the present embodiment is particularly great in the inspection with the transmission optical system.

[Second Embodiment]
Next, a second embodiment of the present invention will be described. The second embodiment is an example in which the mark patterns 47 and 49 are omitted from the pattern data 41 and 42 described above. The second embodiment will mainly describe differences from the first embodiment, and description of similar points will be omitted.

  FIG. 7A is a diagram illustrating the transparent film 11 a according to the second embodiment, and is an example of an image obtained by imaging the transparent film 11 a with the imaging unit 15.

The transparent film 11a is provided with marks 27 and 29 not only on the side of the wiring patterns 23 and 25 but also on the upper side. Further, the distance D ₁ between the side mark 27 and the side of the wiring pattern 23, the distance D ₂ between the upper mark 27 and the upper side of the wiring pattern 23, and the distance between the side mark 29 and the side of the wiring pattern 25. The distance D ₃ and the distance D ₄ between the upper mark 29 and the upper side of the wiring pattern 25 are each set to a predetermined value.

  FIG. 7B is a diagram showing pattern data 41a (table pattern data) used for setting the inspection area of the wiring pattern 23. FIG. 7B is pattern data 42a (table data used for setting the inspection area of the wiring pattern 25). It is a figure which shows back pattern data. As shown in each drawing, in the second embodiment, the mark patterns 47 and 49 are omitted from the pattern data 41a and 42a.

In this embodiment, when setting the inspection region of the wiring pattern 23 in S102, the control unit 31 of the image processing unit 17 detects the mark 27 on the image as shown in FIG. , so that the distance D ₂ the distance D ₁ becomes the distance is above the side edge of the mark 27 and the reference pattern 43 of the lateral distance between the upper side of the upper mark 27 and the reference pattern 43 and the reference pattern 43 is aligned, and the area of the reference pattern 43 on the image at this time is set as the inspection area. Accordingly, the same inspection as described above can be performed in S103.

Similarly in S104, the control unit 31 of the image processing unit 17 detects the mark 29 on the image as shown in FIG. 8B and detects the side mark 29 and the side of the reference pattern 45. aligning distance becomes the distance D ₃ described above, the reference pattern 45 so that the distance between the upper side of the upper mark 29 and the reference pattern 45 is a distance D ₄ described above with reference patterns on the time of image The area 45 is an inspection area. Thus, the same inspection as described above can be performed in S106.

  In the second embodiment, the same effect as in the first embodiment can be obtained. Further, there is an advantage that it is not necessary to set the mark patterns 47 and 49 as the pattern data 41a and 42a. On the other hand, in the first embodiment, there is an advantage that the inspection area can be set with high accuracy by performing alignment using the mark patterns 47 and 49.

  In the above embodiment, an example in which a pattern such as a metal thin film formed on the front and back surfaces of the transparent film 11 is inspected with a transparent electrode film or the like has been described, but the method of the present invention is not limited thereto. It can be applied when inspecting various patterns formed on the front and back of a transparent substrate.

  As mentioned above, although embodiment of this invention was described referring an accompanying drawing, the technical scope of this invention is not influenced by embodiment mentioned above. It is obvious for those skilled in the art that various modifications or modifications can be conceived within the scope of the technical idea described in the claims. It is understood that it belongs.

DESCRIPTION OF SYMBOLS 1 ......... Pattern inspection apparatus 11 ......... Transparent film 13 ......... Irradiation part 15 ......... Imaging part 17 ......... Image processing part 23, 25 ......... Wiring pattern 27, 29 ......... Mark 43, 45 ……… Reference pattern 47, 49 ……… Mark pattern

Claims (5)

A pattern inspection apparatus for inspecting the appearance of a front pattern and a back pattern formed on the front and back of a transparent substrate,
An imaging unit for imaging the substrate;
An image processing unit that performs inspection by determining pass / fail of the front pattern and the back pattern using an image captured by the imaging unit;
With
In the base material, corresponding to each of the front pattern and the back pattern, a front mark for alignment different in form, a back mark is formed,
The image processing unit
Storing front pattern data including a front reference pattern indicating the front pattern area; and back pattern data including a back reference pattern indicating the back pattern area;
The table reference pattern is aligned using the table mark on the image, the area of the table reference pattern is set as an inspection area of the table pattern,
The back reference pattern is aligned using the back mark on the image, and a region of the back reference pattern is set as an inspection region of the back pattern.   The pattern inspection apparatus according to claim 1, wherein the front mark and the back mark have different shapes.   The pattern inspection apparatus according to claim 1, wherein the imaging unit images light that has been irradiated onto the base material and transmitted through the base material. The table pattern data includes a table mark pattern corresponding to the table mark,
The back pattern data includes a back mark pattern corresponding to the back mark,
The image processing unit
By aligning the table mark pattern and the position of the table mark on the image, the table reference pattern is aligned,
The pattern inspection apparatus according to claim 1, wherein the front reference pattern is aligned by aligning the position of the back mark pattern and the back mark on the image. . A pattern inspection method for inspecting the appearance of a front pattern and a back pattern formed on the front and back of a transparent substrate,
An imaging step in which the imaging unit images the substrate;
An inspection step in which an image processing unit performs an inspection by determining pass / fail of the front pattern and the back pattern using an image captured by the imaging unit;
Have
In the base material, corresponding to each of the front pattern and the back pattern, a front mark for alignment different in form, a back mark is formed,
The image processing unit
Storing front pattern data including a front reference pattern indicating the front pattern area; and back pattern data including a back reference pattern indicating the back pattern area;
In the inspection step, the image processing unit includes:
The table reference pattern is aligned using the table mark on the image, the area of the table reference pattern is set as an inspection area of the table pattern,
A pattern inspection method comprising: aligning the back reference pattern using the back mark on the image, and setting a region of the back reference pattern as an inspection region of the back pattern.

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