JP2009175035A - Inspection method and inspection apparatus - Google Patents

Abstract

An inspection method capable of obtaining a difference between two image data by illuminating light of two different wavelengths and transmitting or reflecting the inspection object, and detecting a defect of the inspection object from the difference. Provide inspection equipment.
An object to be inspected is illuminated with two types of light having different wavelengths including blue light, and a difference between data of two images created based on light transmitted or reflected by the object to be inspected is determined. A defect of the inspection object is detected from the difference. Illumination means for illuminating the inspection object with light of two kinds of wavelengths including blue light, and after the light of two kinds of wavelengths is illuminated from the illumination means to the inspection object and transmitted or reflected by the inspection object, 2 Imaging means for capturing one image and image processing means for detecting a defect of the inspection object from the data of the two images of the imaged inspection object, the data of the two images obtained by the imaging means The difference is obtained and the defect of the inspection object is detected.
[Selection] Figure 1

Description

  The present invention relates to an inspection method and an inspection apparatus, for example, TAB (tape automated bonding) or COF (chip on) which is a film substrate (flexible substrate) used for a liquid crystal driver such as a liquid crystal television and a liquid crystal monitor for a personal computer. -It relates to an inspection method and an inspection apparatus for inspecting an inspection object such as a film).

  Liquid crystal drivers such as liquid crystal televisions, personal computer liquid crystal monitors, mobile phone liquid crystal monitors, in-car mobile liquid crystal monitors such as car navigation systems, and digital camera liquid crystal monitors are currently mounted using film substrates.

  There are two types of film substrates: TAB (tape automated bonding), which is a conventional technology, and COF (chip on film), which is a new technology. The COF is excellent in miniaturization of wiring because a hole is not required in the joint portion of the LSI because of structural characteristics.

  In recent years, in COF, there is an increasing demand for inspecting the presence or absence of foreign matter (defects) sandwiched between a mounted chip and a film in a reel-to-reel state.

  Further, for example, the liquid crystal driver needs to be miniaturized in order to make the entire apparatus such as a liquid crystal television, a personal computer, and a mobile phone light and thin. Moreover, although the number of pixels is increased in high-definition televisions using liquid crystal, the chip size is suppressed.

  For the above reasons, the bumps have a narrow pitch, and there is an increased possibility that a minute foreign matter between the bumps contacting the IL (inner lead) becomes a defect and causes a problem such as a short circuit. .

  Therefore, conventionally, for example, a second illumination means (an epi-illumination device, a coaxial epi-illumination device) is disposed on the side opposite to the display surface side of the liquid crystal panel to be inspected, and the light transmitted through the part including the anisotropic conductive film is transmitted. The presence of an abnormality (defect) related to the position of the anisotropic conductive film relative to the transparent substrate (electrode pattern) using the image obtained by the image pickup means (color CCD) (image by coaxial incident illumination), the transparent substrate There are known inspection apparatuses for determining the presence or absence of abnormalities (defects) related to foreign matters such as dust in electrode patterns and anisotropic conductive films (for example, paragraphs 0028 to 0045, particularly paragraphs 0034 to 0038 of FIG. 1). 4).

In addition, it is a color that is difficult to be absorbed by the resin that constitutes the anisotropic conductive film (or paste) (for example, red light), a flexible substrate such as an FPC, and a tape substrate (flexible substrate) that is used for mounting COF, TAB, etc. ), A technique for illuminating electronic components such as a resistor chip and a capacitor chip and determining the presence or absence of defects such as foreign matter and scratches (see Patent Document 1, especially paragraph 0087, FIG. 4).
JP 2005-122059 A

  However, when an object to be inspected such as a film substrate (flexible substrate) is illuminated only by red light, it is difficult to determine a defect such as a foreign substance or a scratch existing inside the film substrate (flexible substrate). Even if the illumination angle to the liquid crystal panel is changed by ring illumination or coaxial illumination, it is possible to accurately determine whether the dust is present on the surface of the film substrate (flexible substrate) or a defect such as foreign matter present inside. There was a possibility that I could not.

  Therefore, the present invention illuminates light of two different wavelengths, transmits or reflects the object to be inspected to form two images, obtains a difference between the data of the two images, and inspects from the difference An object is to provide an inspection method and an inspection apparatus capable of detecting a defect of an object.

  In order to solve the above-described problem, the invention according to claim 1 is based on two types of light having different wavelengths that illuminate the inspection object with two types of different wavelengths and transmit or reflect the illuminated inspection target. The inspection method is characterized in that a difference between data of two images created in this way is obtained and a defect of the inspection object is detected from the difference.

  According to a second aspect of the present invention, in the inspection method according to the first aspect, for each of two types of light having different wavelengths, the non-defective image data of the non-defective inspection object and the inspection object under inspection are inspected. In this inspection method, a difference from image data is obtained, and a defect of the inspection object is detected from the difference.

  According to a third aspect of the present invention, there is provided illumination means for illuminating an inspection object with two types of light having different wavelengths, and two types of light having different wavelengths are illuminated from the illumination means to the inspection object. An imaging means for capturing two images of light of two different wavelengths after being transmitted or reflected, and an image for detecting a defect of the inspection object from the data of the two images of the imaged inspection object The inspection apparatus includes a processing unit, calculates a difference between data of two images obtained by the imaging unit, and detects a defect of the inspection object.

  According to a fourth aspect of the present invention, in the inspection apparatus according to the third aspect, a non-defective image of a non-defective inspection object and an inspection image of the inspection object being inspected for each of two types of light having different wavelengths. The inspection apparatus is characterized in that a difference in data is obtained and a defect of the inspection object is detected from the difference.

  Examples of the light having the two types of wavelengths described above include blue light and red light, blue light and yellow light, and blue light and green light.

  According to the present invention, since the defect of the inspection object is detected from the difference between the data of the two images obtained by transmitting or reflecting the inspection object by being irradiated with light of two different wavelengths, the film substrate ( Not only dust existing on the surface of the flexible substrate) but also foreign matters existing inside can be inspected as defects. In particular, even when the bumps have a narrow pitch and a minute foreign matter exists between the bumps in contact with the IL (inner lead), the minute foreign matter can be inspected as a defect.

  Hereinafter, a preferred example of the inspection apparatus according to the present invention will be described.

  As shown in FIG. 1, a film substrate on which a plurality of inspection objects 11 (for example, a COF (chip on film) used in a liquid crystal driver such as a liquid crystal television and a personal computer liquid crystal monitor) are placed at predetermined intervals. 10 is moved in the direction of the arrow.

  The inspection object 11 includes a chip body 11a such as an IC, a lead electrode 11b, and the like. The film substrate 10 and the inspection object 11 are inspected by a lens barrel 13, an image pickup means 12 such as a color CCD provided there, an illumination means 14 having a wavelength variable means, and others. Thereafter, the film substrate 10 is cut at a predetermined interval.

    As an example of the wavelength conversion means, a member in which a plurality of filters of blue, red, yellow, green, pink, etc. are arranged in a turret shape may be provided on the emission end side that emits the light of the illumination means, or the plurality of filters May be provided on the optical axis of the exit end that emits the light of the illumination means.

    The image pickup unit 12, the lens barrel 13, and the illumination unit 14 are disposed immediately above the film 10.

  The light source is preferably provided in the illumination means 14, and the form thereof may be ring illumination, coaxial illumination, or oblique illumination. In ring illumination and oblique illumination, if the chip is dark and the bumps and noise become white, there is no effect, so coaxial illumination is desirable.

  Further, the wavelength of light from the light source can be variably adjusted from blue light to red light by the wavelength variable means in the illumination means 14. A plurality of blue light sources, red light sources, and other color light sources may be arranged without providing such wavelength variable means.

  In addition to the combination of blue light and red light, the light from the light source may be a combination in which one light is blue light and the other light is light such as green light, yellow light, and pink light.

  As shown in FIG. 1, the back surface of the film substrate 10 is irradiated from the lens barrel 13 with blue light and red light from the light source, and an image transmitted or reflected through the film substrate 10 is captured by an imaging means 12 such as a color CCD.

  In the present embodiment, since light having a blue wavelength is not transmitted, only defects on the surface of the film substrate 10 can be detected. On the other hand, since the red wavelength light is transmitted through the film substrate 10, defects on the surface and inside can be detected.

  Since the blue light to be irradiated is directly reflected on the back surface of the film 10, an image of dust or the like attached to the back surface of the film 10 can be taken.

  On the other hand, since the red light is transmitted through the back surface of the film 10 and reflected by the chip body 11a such as an IC, an image of dust or the like attached between the back surface of the film 10 and the film 10 and the chip body 11a is taken. Can do it.

  Therefore, by subtracting the red light image-blue light image, it is possible to extract only an image such as dust attached between the film and the chip. That is, a transmission image of the film substrate 10 by the red wavelength light (“surface and inside”) − a reflection image of the film substrate 10 by the light of the blue wavelength (“surface”) = a defect image of the “inside” of the film substrate 10 Holds.

The combination of blue wavelength light and red wavelength light depends on the material of the transmitting film substrate. In the case of other film substrates, one light is converted into blue light and the other is selected according to the material. The light may be a combination of green light, yellow light, pink light, etc.
A combination in which one light is red light and the other light is green light, yellow light, pink light, or the like may be used.

  For example, first, an inspection image transmitted with red light from a light source on a film substrate 10 which is a non-defective product is picked up and sent to the control means 16 via the image processing means 15 and image recording means incorporated in the control means 16. Remember it. For the film substrate 10 being inspected, the inspection image transmitted by the red light from the light source is similarly sent to the control means 16 via the image processing means 15 and is sent to the image recording means incorporated in the control means 16. Remember. Then, the difference between the stored image data is obtained.

  In this case, not only dust existing on the surface of the film substrate 10 but also dust adhered on the film substrate 10 is imaged as defects simultaneously with the defects existing inside the film substrate 10 and remains in the image data. .

  Furthermore, the back surface of the film substrate 10 is irradiated with blue light from a light source, and an image reflected from the film substrate 10 is captured by a color CCD. An image of the non-defective film substrate 10 is captured in advance with blue light from the light source and stored in an image recording unit built in the control unit 16. For the film substrate 10 being inspected, the inspection image reflected by the blue light from the light source is similarly sent to the control means 16 via the image processing means 15, and is sent to the image recording means incorporated in the control means 16. Remember. And the difference of the data of each memorize | stored image is calculated | required.

  In this case as well, not only defects such as dust adhering to the film substrate 10 but also images present at the same time as defects existing inside the film substrate 10 remain in the image data.

  For each of blue light and red light, two images made based on two different wavelengths of light (that is, blue light and red light) transmitted or reflected by the film substrate 10 (inspection object) The defect of the film substrate 10 is detected from the difference. For example, for each of two types of light having different wavelengths (blue light and red light), the difference between the non-defective image data of the non-defective film substrate 10 and the inspection image data of the film substrate 10 being inspected is calculated. The defect of the film substrate 10 is detected from the difference.

  On the other hand, with respect to blue light, a difference between inspection image data and non-defective image data is obtained, and a defect is detected from the difference.

  On the other hand, for red light, a difference between the inspection image data and the non-defective image data is obtained, and a defect is detected from the difference.

  When the difference between the defect detected with red light and the defect detected with blue light is obtained in this way, the defect on the chip can be extracted.

  A typical example of the film substrate 10 that is an inspection object is one in which an IC chip is bonded to the surface of a film resin, and wiring is projected from the IC chip to the periphery. Not only dust exists on the surface of the film resin, the surface of the IC chip itself, or the wiring surface, but also inside the film resin, the boundary between the wiring and the film, the inside of the wiring, the boundary between the wiring and the IC chip, etc. There can also be foreign objects.

  According to the inspection apparatus of FIG. 1, the difference between the image data of the film substrate 10 of the inspection object by blue light and the image data of the film substrate 10 of the inspection object by red light is obtained. Not only dust existing on the surface of the film substrate 10 but also foreign matters existing inside can be detected as defects.

  In FIG. 1, the imaging unit 12 such as a color CCD, the illumination unit 14 provided with a wavelength variable unit, and the like are arranged directly above the film substrate 10, but the present invention is not limited to this. For example, as shown in FIG. 2, an imaging unit 12 such as a color CCD and an illumination unit 14 having a wavelength variable unit may be arranged directly below the film substrate 10 according to the type of the film substrate. An imaging unit 12 such as a color CCD and an illuminating unit 14 having a wavelength varying unit may be disposed both directly above and below the film substrate 10 according to the type of the film substrate. Further, the illumination means 14 provided with the wavelength variable means may be arranged directly above the film substrate 10 separately from the image pickup means 12 such as a color CCD, and the arrangement position of the image pickup means 12 such as a color CCD. You may arrange | position just under the reverse film board | substrate 10. FIG. Further, the illumination means 14 provided with the wavelength variable means may be arranged directly below the film substrate, and the imaging means 12 such as a color CCD may be arranged directly above the film substrate.

  A plurality of imaging means such as color CCDs having different imaging areas may be arranged, or a plurality of color illumination means may be arranged.

  Since the inspection apparatus of the present invention is easy to make a simple configuration, it is arranged on the COF assembly line and placed on a line for IC chip installation, sealing resin injection, soldering, chip component installation, etc. An inspection device can be arranged to remove defective products on the assembly line, thereby shortening the work time.

Explanatory drawing which shows the inspection apparatus by one Example of this invention. Explanatory drawing which shows the modification of an inspection apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Film substrate 11 Inspection target object 12 Imaging means 13 Lens barrel 14 Illumination means 15 Image processing means 16 Control means

Claims (4)

  Illuminate the inspection object with two different wavelengths of light, and determine the difference between the data of the two images created based on the two different wavelengths of light transmitted or reflected by the illuminated inspection object; An inspection method comprising detecting a defect of an inspection object from a difference.   In the inspection method according to claim 1, for each of two kinds of light having different wavelengths, a difference between the data of the non-defective image of the non-defective inspection object and the data of the inspection image of the inspection object under inspection is obtained, An inspection method comprising detecting a defect of an inspection object from a difference.   Illumination means for illuminating the inspection object with two different wavelengths of light, and two kinds of light after the illumination means illuminates the inspection object and transmits or reflects the inspection object. Image pickup means for picking up two images of light of different wavelengths, and image processing means for detecting defects in the inspection object from the data of the two images of the picked up inspection object. An inspection apparatus characterized by obtaining a difference between data of two images and detecting a defect of an inspection object.   In the inspection apparatus according to claim 3, for each of two types of light having different wavelengths, the difference between the non-defective image data of the non-defective inspection object and the inspection image data of the inspection object under inspection is obtained. An inspection apparatus for detecting a defect of an inspection object from the difference.

Images