JP2021081389A - Method and device for inspecting metalized film - Google Patents

Abstract

To provide a method for inspecting a metalized film having a non-deposition unit.SOLUTION: The present invention includes the steps of: taking an image of a metalization film 10 and obtaining the image (S31); executing pattern matching processing on the image and cutting out a region which corresponds to a reference image 13 (S33 to S36); extracting an image 15 of a non-deposited unit 12 from the cut-out image 14 (S37); calculating the luminance of the extracted image 15 (S38); and comparing and determining the calculated value and the reference value (S39).SELECTED DRAWING: Figure 5

Description

The present invention relates to an inspection method and an inspection apparatus for a metallized film.

A general metallized film used for a film capacitor is surrounded by a non-deposited metal-deposited portion, leaving a narrow portion as a fuse portion on an electrode portion composed of a metal-deposited vapor-deposited portion. A small electrode portion is formed. Conventionally, the quality inspection of non-deposited parts has generally been performed visually by an inspector, but in many cases it relies on the inspector's subjective visual judgment, making it difficult to ensure consistency of quality and stabilizing product quality. I was involved. In addition, it is difficult to visually judge minute defects, and there is a possibility that they will be overlooked.

As a method for inspecting a film without visual inspection, for example, Patent Document 1 can be mentioned.

JP-A-2017-110949

However, since the inspection method of Patent Document 1 is to image the transmitted light from the film and inspect the presence or absence of defects from the change in light intensity due to the defects, the metallized film provided with the vapor-deposited portion and the non-deposited portion. When applied to, since the light intensity changes depending on the non-deposited portion, it cannot be distinguished from the change in light intensity caused by the defect, and the defect cannot be identified.

Therefore, an object of the present invention is to provide an inspection method and an inspection apparatus for a metallized film provided with a non-deposited portion.

The method for inspecting a metallized film of the present invention is a method for inspecting a metallized film for a film capacitor including a vapor-deposited portion 11 and a non-deposited portion 12, and is a step of obtaining an image by imaging the metallized film 10 (S31). A step (S33 to S36) of executing a pattern matching process on the captured image and cutting out a region corresponding to the reference image 13, and a step of extracting the image 15 of the non-deposited portion from the cut out image 14. (S37), a step (S38) for calculating the brightness of the extracted extracted image 15, and a step (S39) for comparing and determining the calculated value and the reference value are provided.

In the above inspection method, it is preferable to include a step (S38) of calculating the brightness of the entire cutout image 14.

Further, it is preferable to include a step (S36) of determining a defect when the region corresponding to the reference image 13 cannot be cut out.

Further, it is preferable to include steps (S11 to S18) for creating the reference image 13 and steps (S21 to S23) for creating the reference value.

Furthermore, it is preferable that the step of creating the reference image 13 includes a step (S17) of binarizing the image.

The metallized film inspection device of the present invention is a metallized film inspection device 1 for a film capacitor including a vapor-deposited portion 11 and a non-vapor-deposited portion 12, and is an imaging unit 3 that obtains an image by imaging the metallized film 10. Then, the pattern matching process is executed on the image captured by the imaging unit 3, and the detection unit 72 that cuts out the region corresponding to the reference image 13 and the non-deposited unit 12 from the cutout image 14 cut out by the detection unit 72. It includes an extraction unit 75 for extracting an image, a calculation unit 76 for calculating the brightness of the extracted image extracted by the extraction unit 75, and a determination unit 77 for comparing and determining a value calculated by the calculation unit 76 and a reference value. It is characterized by that.

The metallized film inspection method and inspection apparatus of the present invention enable inspection without visual inspection.

It is a figure which shows the inspection apparatus of the metallized film of one Embodiment of this invention. It is a figure which shows the metallized film. It is a flowchart of a reference image creation process. It is a flowchart of a reference value creation process. It is a flowchart of a pass / fail judgment process. It is a figure which shows the reference image. It is a figure which shows the cut-out image. FIG. 8a is a graph showing the brightness distribution of non-defective products, and FIG. 8b is a graph showing the brightness distribution of defective products.

Next, an embodiment of the metallized film inspection apparatus of the present invention will be described in detail with reference to the drawings. As shown in FIG. 1, the inspection device 1 of the present invention obtains an image by photographing the illumination unit 2 that irradiates the metallized film 10 with light and the metallized film 10 that is irradiated with the light from the illumination unit 2. It includes an imaging unit 3 and a quality determining unit 4 that determines the quality of the metallized film 10 based on the image captured by the imaging unit 3.

(Metallic film)
The metallized film 10 is obtained by depositing metal on a dielectric film, and as shown in FIG. 2, includes a vapor-deposited portion 11 on which metal is vapor-deposited and a non-deposited portion 12 on which metal is not vapor-deposited. ing. Although the shape of the non-deposited portion 12 is substantially a cross, it may have various shapes such as a rod shape (straight line shape), a T shape shape, a cross shape, and a diagonal line. The thickness of the dielectric film is, for example, 2 to 15 μm, the thickness of the vapor-deposited portion is, for example, 0.02 to 10 μm, and the width of the non-deposited portion is, for example, 0.2 to 10 mm.

(Lighting section)
The lighting unit 2 is a transmissive illuminating table provided with a light-transmitting mounting surface such as glass on a light source such as an LED (light emitting diode), a fluorescent lamp, a halogen lamp, or a metal halide lamp, and is made of metal on the mounting surface. The chemical film 10 can be placed on it.

(Image pickup unit)
The imaging unit 3 is a camera including a photographing lens and an imaging element, and is, for example, a USB camera provided with a USB terminal for inputting an imaging instruction and outputting an image. The number of pixels is, for example, 640 × 480, but it can be appropriately changed according to the metallized film to be inspected.

(Good / bad judgment unit)
The quality determination unit 4 is a reference image creation unit 5 that creates a reference image 13 based on the image captured by the imaging unit 3, and a reference value creation unit that creates a reference value based on the image captured by the imaging unit 3. 6 and the first determination unit 7 that determines the quality of the metallized film 10 based on the reference image 13 and the reference value, and a simple determination that determines the quality of the metallized film 10 based on the degree of correlation with the reference image 13. It is provided with a part 8.

The pass / fail determination unit 4 is generally provided with a calculation unit (CPU), a storage unit (nonvolatile memory, volatile memory, storage device), a display unit (display), an interface (keyboard, mouse), and the like. It can be realized by a simple computer. A pass / fail judgment program is stored in the storage unit, and pass / fail judgment is performed according to this. Further, the storage unit may also serve as the first storage unit 55 and the second storage unit 63, which will be described later.

(Reference image creation department)
The reference image creating unit 5 executes pattern matching processing on the first noise removing unit 51 for removing noise of the image and the captured image of the non-defective product, and corresponds to the ideal image from the captured images of the non-defective product. A first detection unit 52 that cuts out an area to be processed, a conversion unit 56 that binarizes the cut-out image 14A cut out by the first detection unit 52, and a first storage unit that stores the binarized image as a reference image 13. It is equipped with 55. The ideal image is an image based on the design data. The captured image of the non-defective product is an image of the non-defective product of the vapor deposition pattern of the actual metallized film 10.

The first detection unit 52 includes a first angle correction unit 53 that rotates an image based on an ideal image, and a first cutout unit 54 that cuts out an image including a non-deposited unit 12 from the image based on the ideal image. ..

The first angle correction unit 53 includes an image reduction unit 53a that generates a reduced image obtained by reducing a non-defective image and an ideal image, and a rotation angle grasping unit 53 that compares both reduced images and grasps the rotation angle. A rotation unit 53b and a rotation unit 53c for rotating an image based on the rotation angle grasped by the rotation angle grasping unit 53b are provided.

(Reference value creation department)
The reference value creating unit 6 includes a first image extraction unit 61 that extracts an image of the non-deposited unit 12 from the cutout image 14A cut out by the first cutout unit 54, and an extracted image 15 extracted by the first image extraction unit 61. The light transmittance and the brightness are calculated from the first calculation unit 62, which calculates the brightness of the entire cutout image 14A (not the reference image 13), and the values calculated by the first calculation unit 62 are stored as reference values. A second storage unit 63 is provided.

(1st judgment unit)
The first determination unit 7 executes a pattern matching process on the captured image with the second noise removing unit 71 that removes the noise of the image, and selects a region corresponding to the reference image 13 from the captured image. The second detection unit 72 to be cut out, the second image extraction unit 75 to extract the image of the non-deposited unit 12 from the cutout image 14 cut out by the second detection unit 72, and the extracted image extracted by the second image extraction unit 75. The second calculation unit 76, which calculates the light transmission coefficient and the brightness of the 15 and also calculates the brightness of the entire cut-out image 14, and the second determination unit, which compares and determines the value calculated by the second calculation unit 76 with the reference value. It has 77 and.

The second detection unit 72 includes a second angle correction unit 73 that rotates the image based on the reference image 13, and a second cutout unit 74 that cuts out an image including the non-deposited unit 12 from the image based on the reference image 13. ing.

The second angle correction unit 73 compares the image reduction unit 73a that generates a reduced image obtained by reducing the image of the metallized film 10 to be inspected and the reference image 13 and both reduced images, and the rotation angle. It is provided with a rotation angle grasping unit 73b for grasping the image, and a rotating unit 73c for rotating an image based on the rotation angle grasped by the rotation angle grasping unit 73b.

(Inspection method)
Next, an inspection method using the inspection apparatus 1 will be described.

(Imaging process)
A metallized film 10 is placed on the mounting surface of the illumination unit 2 to irradiate light from a light source, and the light transmitted through the metallized film 10 is imaged by the imaging unit 3 (S11 in FIG. 3 and S31 in FIG. 5). ). At this time, the image may be taken so as to match the angle between the non-deposited portion 12 of the ideal image or the reference image 13 and the non-deposited portion 12 of the metallized film 10 to be inspected. In this case, the angle correction described below becomes unnecessary. Further, it is preferable to take an image centering on the pattern of the non-deposited portion 12 (one of the continuous patterns: a cross shape in the case of FIG. 2). However, it suffices if the image contains one or more patterns. Since the pass / fail judgment is performed for each pattern, if the image contains a plurality of patterns, the pass / fail judgment is repeated for the number of patterns.

(Reference image creation process)
Subsequently, the reference image 13 is created. First, the first noise removing unit 51 removes noise from a non-defective image captured by the imaging unit 3 (S12 in FIG. 3). Specifically, since noise caused by the illumination unit 2 and the image pickup unit 3 is generated in the image, the noise is removed by filtering the image.

Next, pattern matching processing is executed on the image from which noise has been removed, and a region corresponding to the ideal image is cut out from the captured image. Specifically, first, the image reduction unit 53a reduces both the preset ideal image and the noise-removed image to output two reduced images (S13). Next, the rotation angle grasping unit 53b compares the two reduced images, and how much the image should be rotated so that the non-deposited portion 12 of the ideal image and the non-deposited portion 12 of the captured image have the same shape. (Whether the angles are equal) is grasped, and the angle at which the image is rotated is grasped (S14). Then, the rotating unit 53c rotates the image (not the reduced image) based on the angle grasped by the rotation angle grasping unit 53b (S15). Next, the first cutout portion 54 cuts out an image including the non-deposited portion 12 from the image based on the ideal image (S16). Specifically, a range in which the degree of correlation with the ideal image is high is specified and cut out. That is, the size of the vapor-deposited portion 11, the size of the non-deposited portion 12, and the positional relationship between the vapor-deposited portion 11 and the non-deposited portion 12 are cut out so as to be substantially equal to the ideal image. The ideal image is an image including a pattern (for example, a cross shape) of the non-deposited portion 12. Therefore, the cut-out image 14A cut out by the first cut-out portion 54 is an image including the pattern of the non-deposited portion 12 (see FIG. 7).

Then, the conversion unit 56 binarizes the cut-out image 14A (S17), and then stores the binarized image as the reference image 13 in the first storage unit 55 (S18) to complete the reference image creation step. To do. By creating the reference image 13 based on the actual metallized film 10 in this way, it is possible to set a reference that is more realistic than the ideal image, and it is possible to make an accurate quality judgment.

(Standard value creation process)
Next, create a reference value. First, the first image extraction unit 61 extracts the image of the non-deposited unit 12 from the cutout image 14A cut out by the first cutout unit 54 (S21 in FIG. 4). At this time, the frame is framed in a rectangular shape (see the broken line in FIG. 7). Further, it is preferable to frame the non-deposited portion 12 in a range slightly smaller than the size of the non-deposited portion 12. Subsequently, the first calculation unit 62 calculates the light transmittance and the brightness of the extracted image 15 extracted by the first image extraction unit 61, and also calculates the brightness of the entire cutout image 14A (S22). For example, the average brightness, the variation in brightness (standard deviation), and the light transmittance of the entire extracted image 15 are calculated. The light transmittance is calculated based on a formula for converting the brightness value (0 to 255) of the image into a percentage in advance. In addition, the average brightness and the variation (standard deviation) of the brightness of the entire cutout image 14A are calculated. Then, the value calculated by the first calculation unit 62 is stored in the second storage unit 63 as a reference value (S23), and the reference value creation step is completed.

(Good / bad judgment process)
After the reference image 13 and the reference value are created, a pass / fail judgment is performed next. First, the metallized film 10 to be inspected is imaged based on the above imaging step (S31 in FIG. 5). Next, the second noise removing unit 71 removes noise of the image to be inspected captured by the imaging unit 3 (S32). The noise removing method is the same as that of the first noise removing unit 51.

Next, a pattern matching process is executed on the image from which noise has been removed, and a region corresponding to the reference image 13 is cut out from the captured image. Specifically, first, the image reduction unit 73a reduces both the reference image 13 and the noise-removed image to output two reduced images (S33). Next, the rotation angle grasping unit 73b compares the two reduced images, and how much the image should be rotated so that the non-deposited portion 12 of the reference image 13 and the non-deposited portion 12 of the captured image have the same shape. (Whether the angles are equal) is grasped, and the angle at which the image is rotated is grasped (S34). Then, the rotating unit 73c rotates the image (not the reduced image) based on the angle grasped by the rotation angle grasping unit 73b (S35). Next, the second cutout portion 74 cuts out an image including the non-deposited portion 12 from the image based on the reference image 13 (S36). Specifically, a range in which the degree of correlation with the reference image 13 is high is designated and cut out. That is, the size of the vapor-deposited portion 11, the size of the non-deposited portion 12, and the positional relationship between the vapor-deposited portion 11 and the non-deposited portion 12 are cut out so as to be substantially equal to the reference image 13. As shown in FIG. 6, the reference image 13 is an image including a pattern (for example, a cross shape) of the non-deposited portion 12. Therefore, the cut-out image 14 cut out by the second cut-out portion 74 is an image including the pattern of the non-deposited portion 12.

At this time, if the non-deposited portion 12 has a defect such as a shape collapse, chipping, or stain, the degree of correlation between the reference image 13 and the image does not satisfy a predetermined value. Therefore, the region corresponding to the reference image 13 cannot be cut out from the captured image, and a defect determination is made at this point. That is, at this stage, the simple determination unit 8 that determines the quality of the metallized film 10 based on the degree of correlation with the reference image 13 works.

When the simple determination unit 8 makes a good judgment, that is, when the cutout image 14 is output from the second cutout unit 74, the second image extraction unit 75 then extracts the image of the non-deposited unit 12 from the cutout image 14. (S37). At this time, as shown in FIG. 7, the frame is framed in a rectangular shape. Further, it is preferable to frame the non-deposited portion 12 in a range slightly smaller than the size of the non-deposited portion 12. Subsequently, the second calculation unit 76 calculates the light transmittance and the brightness of the extracted image 15 extracted by the second image extraction unit 75, and also calculates the brightness of the entire cutout image 14 (S38). For example, the average brightness, the variation in brightness (standard deviation), and the light transmittance of the entire extracted image 15 are calculated. Regarding the light transmittance, a formula for converting the brightness value of the image (0 to 255: 0 is the state where no light is transmitted at all, 255 is the state without the film) to a percentage is set in advance, and this conversion is performed. Calculate based on the formula. In addition, the average brightness and the variation (standard deviation) of the brightness of the entire cutout image 14 are calculated.

Then, the second determination unit 77 compares the value calculated by the second calculation unit 76 with the preset reference value, and determines the quality of the inspection target (S39). For example, as shown in FIG. 8a, in the case of a non-defective product, the brightness of the vapor-deposited portion 11 and the brightness of the non-deposited portion 12 are clearly distinguished, so that two peaks (peaks) can be seen. On the other hand, the brightness of the non-deposited portion 12 is low in the defective portion (when the vapor-deposited metal is adhered to the non-deposited portion 12, etc.), and the peak of the non-deposited portion 12 cannot be seen. If there is a defect portion in this way, the variation in brightness tends to be large. Therefore, the quality of the non-deposited unit 12 can be determined by comparing the values calculated by the second calculation unit 76 (light transmittance and brightness variation of the extracted image 15) with the corresponding reference values. Further, when the film thickness of the vapor deposition portion 11 is thin, the average brightness of the entire cutout image 14 tends to be large. Therefore, the quality of the vapor deposition unit 11 can be determined by comparing the value calculated by the second calculation unit 76 (the average brightness of the entire cutout image 14) with the corresponding reference value.

As described above, in the present invention, it can be easily applied to a metallized film for a film capacitor in which a thin-film deposition portion 11 and a non-evaporation portion 12 are present, and vapor deposition is performed with a reliable and constant quality standard without relying on the visual inspection of an inspector. The quality of the pattern can be judged. In addition, since the light transmittance and the brightness variation are compared instead of the comparison between the images, it is possible to grasp the difference between the varieties and the change with time, and it is possible to find out minute defects and fluctuations.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the present invention. For example, in FIG. 2, only the cross-shaped pattern is shown, but there is also a metallized film having a plurality of types of patterns. In this case, the reference image 13 may be set for each pattern, and the image may be cut out based on the reference image 13 having the highest correlation degree.

When a non-defective image or an ideal image based on a design drawing is used as the reference image 13, the reference image creation step is unnecessary. Further, when an ideal value, a standard value, or the like is used as the reference value, the reference value creation step is unnecessary. Further, it is not necessary to provide the reference image creating unit 5 and the reference value creating unit 6.

The image reduction units 53a and 73a and the rotation angle grasping units 53b and 73b do not necessarily have to be provided. That is, the image may be rotated by comparing the ideal image or the reference image 13 with the unreduced image.

First noise removing unit 51 and second noise removing unit 71, first detection unit 52 and second detection unit 72, first angle correction unit 53 and second angle correction unit 73, first cutting unit 54 and second cutting unit 74, the first storage unit 55 and the second storage unit 63, the first image extraction unit 61 and the second image extraction unit 75, and the first calculation unit 62 and the second calculation unit 76 may be combined into the other. That is, for example, the first noise removing unit 51 may also serve as the second noise removing unit 71.

Further, although the image pickup unit 3 has captured the light transmitted through the metallized film 10, the light image reflected from the metallized film 10 may be captured.

The present invention also includes the following configurations.

An inspection device for a metallized film for a film capacitor including a metal vapor deposition unit and a non-metal deposition unit, an illumination unit that irradiates the metallized film with light, an imaging unit that images the metallized film to obtain an image, and an imaging unit. It is provided with a quality determination unit that determines the quality of the metallized film based on the image captured by the imaging unit, and the quality determination unit rotates the image based on the noise removal unit that removes the noise of the image and the reference image. An angle correction unit, a cutting unit that cuts out an image including a non-metal vapor deposition part from an image based on a reference image, an image extraction unit that extracts an image of the non-metal vapor deposition part from the cutout image cut out by the cutout unit, and an image extraction unit. An inspection device for a metallized film, comprising a calculation unit for calculating the light transmittance and brightness of the extracted image extracted by the unit, and a determination unit for comparing and determining a value calculated by the calculation unit and a reference value.

An inspection device for a metallized film for a film capacitor including a metal vapor deposition unit and a non-metal deposition unit, an illumination unit that irradiates the metallized film with light, an imaging unit that images the metallized film to obtain an image, and an imaging unit. A reference image creation unit that includes a quality determination unit that determines the quality of the metallized film based on the image captured by the imaging unit, and the quality determination unit creates a reference image based on the image captured by the imaging unit. A reference value creating unit for creating a reference value and a first determination unit for determining the quality of the metallized film based on the reference image and the reference value are provided, and the reference image creating unit removes noise from the image. 1 Noise removal section, a first angle correction section that rotates the image based on the ideal image, a first cutout section that cuts out an image including a non-metal vapor deposition section from the image based on the ideal image, and a first cutout section. A first storage unit that stores the cut-out image as a reference image, and a first image extraction unit that extracts an image of the non-metal vapor deposition part from the cut-out image cut out by the first cut-out unit. A first calculation unit that calculates the light transmittance and brightness from the extracted image extracted by the first image extraction unit, and a second storage unit that stores the value calculated by the first calculation unit as a reference value are provided. The first determination unit removes noise from the image to be inspected, a second noise removal unit, a second angle correction unit that rotates the image based on the reference image, and a non-metal vapor deposition unit from the image based on the reference image. The light of the second cutout part that cuts out the including image, the second image extraction part that extracts the image of the non-metal vapor deposition part from the cutout image cut out by the second cutout part, and the extracted image extracted by the second image extraction part. An inspection device for a metallized film, comprising a second calculation unit for calculating the transmittance and brightness, and a second determination unit for comparing and determining a value calculated by the second calculation unit and a reference value.

The rotation in which the first angle correction unit and / or the second angle correction unit grasps the rotation angle by comparing the image reduction unit that generates a reduced image obtained by reducing the image with the ideal image or the reference image and the reduced image. A metallized film inspection device including an angle grasping unit and a rotating unit that rotates an image based on the rotation angle grasped by the rotation angle grasping unit.

A metallized film inspection device in which a reference image creating unit includes a conversion unit that binarizes an image from which noise has been removed by a first noise removing unit.

An inspection device for a metallized film, which is provided with a simple judgment unit that determines the quality of the metallized film based on the degree of correlation with a reference image.

1 Inspection device 2 Lighting unit 3 Imaging unit 4 Good / bad judgment unit 5 Reference image creation unit 51 1st noise removal unit 52 1st detection unit 53 1st angle correction unit 53a Image reduction unit 53b Rotation angle grasping unit 53c Rotation unit 54 1st Cutout unit 55 1st storage unit 56 Conversion unit 6 Reference value creation unit 61 1st image extraction unit 62 1st calculation unit 63 2nd storage unit 7 1st judgment unit 71 2nd noise removal unit 72 2nd detection unit 73 2nd Angle correction unit 73a Image reduction unit 73b Rotation angle grasping unit 73c Rotating unit 74 Second cutting unit 75 Second image extraction unit 76 Second calculation unit 77 Second determination unit 8 Simple judgment unit 10 Metallized film 11 Vapor deposition unit 12 Non-deposition Part 13 Reference image 14 Cut-out image cut out by the second cut-out part 14A Cut-out image cut out by the first cut-out part 15 Extracted image

Claims (6)

A method for inspecting a metallized film for a film capacitor having a vapor-deposited portion and a non-deposited portion.
The steps to obtain an image by imaging a metallized film,
A step of executing pattern matching processing on the captured image and cutting out an area corresponding to the reference image,
The step of extracting the image of the non-deposited part from the cut out image and
Steps to calculate the brightness of the extracted extracted image,
Steps to compare and judge the calculated value and the reference value,
A method for inspecting a metallized film. The method for inspecting a metallized film according to claim 1, further comprising a step of calculating the brightness of the entire cropped image. The method for inspecting a metallized film according to claim 1 or 2, further comprising a step of determining a defect when a region corresponding to a reference image cannot be cut out. Steps to create a reference image and
Steps to create a reference value and
The method for inspecting a metallized film according to any one of claims 1 to 3. The method for inspecting a metallized film according to claim 4, wherein the step of creating a reference image includes a step of binarizing the image. An inspection device for metallized films for film capacitors, which includes a vapor-deposited portion and a non-deposited portion.
An imaging unit that captures an image of a metallized film and obtains an image,
A detection unit that executes pattern matching processing on the image captured by the imaging unit and cuts out an area corresponding to the reference image.
An extraction unit that extracts the image of the non-deposited part from the cut-out image cut out by the detection unit,
A calculation unit that calculates the brightness of the extracted image extracted by the extraction unit,
Judgment unit that compares and judges the value calculated by the calculation unit and the reference value,
A metallized film inspection device.

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