JP2011007695A - Apparatus for detecting pasted state - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enlarge a difference of light contrasts between a part having a pasted sheet material thereon and a part having no sheet material, in order to improve detection accuracy of a pasted state of the sheet material.SOLUTION: An apparatus is provided, which incudes: a light source 2 for irradiating a paste part with light; a photographing device 3 for photographing light reflected from the paste part; and polarizing filters 15, 16 which are disposed in at least one of spaces between the light source 2 and the paste part and between the paste part and the photographing device 3. Accordingly, a specific light portion of the light received by the photographing device can be reduced by using the polarizing filters, thereby enlarging a luminance difference between the part having the pasted sheet material thereon and the part having no sheet material.

Description

  The present invention relates to an application state detection device for detecting an application state of a transparent or translucent sheet material attached to an object to be attached.

  2. Description of the Related Art Conventionally, various electronic components are connected to or mounted on an FPD (Flat Panel Display) such as liquid crystal or plasma around a plurality of processing stations. Specific examples of electronic components to be mounted include mounting of driving ICs, so-called TAB (Tape Automated Bonding) such as COF (Chip on Film), FPC (Flexible Printed Circuit), and PCB (Peripheral Circuit Board: Printed Circuit Board). Can be mentioned. Further, a TCP (Tape Carrier Package) is used for connection between the display substrate and the PCB substrate.

Here, the liquid crystal display panel will be described with reference to FIGS.
FIG. 6 is a front view showing the liquid crystal display panel, and FIG. 7 is a perspective view showing a connection state between the liquid crystal display panel and the printed circuit board.

  As shown in FIG. 6, the liquid crystal display panel 100 includes two TFT (Thin Film Transistor) array substrates 101 and 102, and liquid crystal sealed between the two TFT array substrates. A printed circuit board (PCB) 106 is provided on at least one side of the two TFT array substrates 101 and 102 via a plurality of TCPs 105 made of a flexible substrate on which the IC chip 103 is mounted.

  As shown in FIG. 7, a predetermined number of lead portions 104 are formed on the two TFT array substrates 101 and 102. The lead unit 104 is connected to a plurality of TCPs 105. Further, a PCB 106 is connected to the plurality of TCPs 105. In addition, a plurality of lead portions 107 are provided at predetermined intervals at locations where the PCB 106 is connected to the plurality of TCPs 105.

  The PCB 106 and the TCP 105 are electrically connected by an ACF (Anisotropic Conductive Film) 108. The ACF 108 is formed into a film by dispersing fine metal particles having conductivity in a thermosetting resin (binder resin) made of an adhesive electric insulating material.

  The connection between the PCB 106 and the TCP 105 is performed as follows. First, the ACF 108 is attached to the lead portion 107 of the PCB 106. Then, the TCP 105 is disposed on the lead portion 107 of the PCB 106 to which the ACF 108 is attached, and a thermocompression treatment is performed. As a result, the TCP 105 is bonded to the PCB 106. At this time, the conductive particles dispersed in the ACF 108 are connected to the lead portion 107 of the PCB 106 and the TCP 105, whereby the PCB 106 and the TCP 105 are electrically connected. Then, the binder resin of the ACF 108 is cured, and the PCB 106 and the TCP 105 are integrally fixed via the ACF 108.

  Here, as a method for detecting whether the ACF 108 is accurately attached to a predetermined position on the PCB 106, that is, the lead portion 107, for example, a technique described in Patent Document 1 is proposed. In the technique disclosed in Patent Document 1, light is applied to a pasted portion and light reflected at the pasted portion is photographed. Then, by comparing the contrast of light between the location where the sheet material is applied and the location where the sheet material is not applied from the photographed image signal, it is detected whether the sheet material is applied at an accurate position.

JP 2003-69199 A

  However, since ACF, which is a sheet material, is translucent, there is little difference in luminance from the lead portion of the printed circuit board, which is an object to be pasted. As a result, with the technique disclosed in Patent Document 1, the difference in contrast of reflected light between the pasting location and the non-pasting location does not appear greatly, and the detection accuracy of the pasting state of the sheet material is low.

  The object of the present invention is to increase the difference in light contrast between the location where the transparent or translucent sheet material is applied and the location where the transparent material is not applied in consideration of the above problems, and improve the detection accuracy of the application state of the sheet material. It is in providing the sticking state detection apparatus which can be improved.

In order to solve the above-described problems and achieve the object of the present invention, the pasting state detection device of the present invention is a device that detects the pasting state when a transparent or translucent sheet material is pasted on an object to be pasted.
Furthermore, the sticking state detection device of the present invention includes a light source for irradiating light to a sticking place where a sheet material is stuck on a sticking object, an imaging device for photographing light reflected from the sticking place, a light source and a sticking place. Or a polarizing filter provided in at least one of the pasted portion and the imaging device.

  According to the sticking state detection device of the present invention, it is possible to reduce specific light out of light received by the imaging device by transmitting only light having specific polarization through the polarizing filter. Therefore, the brightness difference between the sheet material and the object to be pasted can be increased, and the contrast ratio between the pasted part and the part not pasted can be increased. As a result, the sticking state of the sheet material can be accurately grasped, and the detection accuracy of the sticking state of the sheet material can be improved.

It is a front view showing typically the 1st example of an embodiment of the pasting state detection device of the present invention. It is a graph which shows the reflectance to glass in P polarized light and S polarized light. It is a graph which shows the difference in contrast ratio by the presence or absence of a polarizing filter. It is a front view which shows typically the 2nd Embodiment of the sticking state detection apparatus of this invention. It is a graph which shows the difference in contrast ratio by the kind of polarizing filter. It is a front view which shows a liquid crystal display panel. It is a perspective view which shows the connection state of a liquid crystal display panel and a printed circuit board.

Hereinafter, embodiments of the sticking state detection device of the present invention will be described with reference to FIGS. In addition, the same code | symbol is attached | subjected to the common member in each figure. The present invention is not limited to the following form.
The description will be given in the following order.
1. First embodiment example 1-1. Configuration example of pasting state detection device 1-2. 1. Measurement example of contrast ratio of sticking state detection device Second embodiment

<1. First Embodiment>
1-1. Configuration Example of Sticking State Detection Device First, a first embodiment example (hereinafter referred to as “this example”) of a sticking state detection device of the present invention will be described with reference to FIGS. 1 and 2.
FIG. 1 is a front view schematically showing a sticking state detection device, and FIG. 2 is a graph showing the reflectance of glass for P-polarized light and S-polarized light.

  The sticking state detection device 1 of this example is a device that detects the sticking state of the ACF 108 when the ACF 108 shown as a specific example of a transparent or translucent sheet material is attached to the PCB 106 shown as a specific example of an object to be pasted. .

  This affixing state detection device 1 includes a light source 2 that irradiates light to the affixed portion of the ACF 108, an imaging device 3 that captures light reflected from the affixed location, an image processing device 4 that is connected to the imaging device 3, and 2 It comprises two polarizing filters 5 and 6.

  The light source 2 is disposed at a position inclined by a predetermined angle θ from a position substantially perpendicular to the pasting location. And this light source 2 is set so that light may enter with respect to a sticking location by predetermined angle (theta).

  The imaging device 3 is disposed at a position inclined at a predetermined angle in a direction opposite to the light source 2 from a position substantially perpendicular to the pasting location. And this imaging device 3 is set so that the light reflected by predetermined angle (theta) from the sticking location may be image | photographed. In this example, the light source 2 and the imaging device 3 are disposed at a position inclined by about 60 °. The imaging device 3 is connected to the image processing device 4 and outputs an image signal to the image processing device 4.

  The image processing device 4 receives the video signal from the imaging device 3, and determines the state of the ACF 108 from the video signal. Specifically, by comparing the contrast between the location where the ACF 108 is applied and the location where the ACF 108 is not applied, it is detected whether the ACF 108 is applied to the lead portion 107 (see FIG. 7) at a desired position. .

  The first polarizing filter 5 is disposed between the light source 2 and the pasted portion, and transmits only light having a specific polarization component among the light emitted from the light source 2. The second polarizing filter 6 is disposed between the pasting location and the imaging device 3 and transmits only light having a specific polarization component among the light reflected from the pasting location.

  In this example, each of the first polarizing filter 5 and the second polarizing filter 6 is a P-polarizing filter that transmits only P-polarized component light. For this reason, only the light of the P-polarized component is irradiated on the pasted portion, and the imaging device 3 captures only the light of the P-polarized component. The P-polarized light is linearly polarized light oscillating in a plane formed by the incident light of the incident surface and the normal direction of the incident surface, and light oscillating in a direction perpendicular to the P-polarized light is referred to as S-polarized light. I'm calling.

  Here, as shown in FIG. 2, when P-polarized light is incident on a glass (n = 1.5) having a refractive index n substantially equal to that of the ACF 108 at an incident angle of about 60 ° from the air, the reflectance of the light is incident. Is almost zero. The angle at which this reflectance is 0 is called the Brewster angle. Therefore, when P-polarized light is incident at the Brewster angle of the ACF 108, the reflectance is 0, and thus no reflection is detected at the location where the ACF 108 is applied.

  As described above, in this example, the light source 2 and the imaging device 3 are disposed at a position inclined by about 60 °, which is a substantially Brewster angle of P-polarized light in the ACF 108. That is, the light source 2 is set so that light is incident at an angle of about 60 ° with respect to the pasting location, and the imaging device 3 captures the light reflected at an angle of about 60 ° from the pasting location. Is set to

  Therefore, the reflected light is greatly reduced at the location where the ACF 108 is applied, and the luminance difference between the reflected light where the ACF 108 is applied and the reflected light where the ACF 108 is not applied increases. As a result, the contrast ratio of light also increases, so that the application state of the ACF 108 can be accurately grasped, and the detection accuracy of the application state can be improved.

  In this example, the light source 2 is set so that light is incident at an angle of about 60 ° with respect to the pasting location, and the imaging device 3 photographs the light reflected at an angle of about 60 ° from the pasting location. Although the example set as above has been described, the present invention is not limited to this. The irradiation angle to the pasting location by the light source 2 and the angle of the reflected light imaged by the imaging device 3 are appropriately set according to the B-polarized Brewster angle of the sheet material for detecting the pasting state.

Here, assuming that the refractive index of air is n ₁ and the refractive index of a transparent or translucent sheet material is n ₂ , the Brewster angle θ of P-polarized light of this sheet material is calculated from the following formula 1.
[Formula 1]
tanθ = n ₂ / n ₁

Moreover, since the refractive index of air is n ₁ ≈1, Equation 1 can be converted into Equation 2 below.
[Formula 2]
tanθ = n ₂

  For this reason, it is preferable to set the irradiation angle to the sticking location by the light source 2 and the angle of the reflected light imaged by the imaging device 3 to the angles calculated by Equation 2.

  In addition, in this example, the example which provided the polarizing filter in the two places between the light source 2 and the sticking location and between the sticking location and the imaging device 3 was demonstrated. However, the purpose of the polarizing filter is achieved by providing the polarizing filter between at least one of the light source 2 and the pasted part or between the pasted part and the imaging device 3.

1-2. Next, an example of measuring the contrast ratio in the presence or absence of the polarizing filter will be described with reference to FIG.
FIG. 3 is a graph showing the difference in contrast ratio depending on the presence or absence of a polarizing filter.

  First, the pasting state detection apparatus used for this measurement will be described. No. Reference numeral 1 denotes a conventional pasting state detection device that is not provided with a polarizing filter. No. Reference numeral 2 denotes an application state detection device in which a P-polarization filter is provided only in a light projecting system between the light source 2 and the application location. No. Reference numeral 3 denotes a sticking state detection device in which a P polarization filter is provided only in a light receiving system between the sticking location and the imaging device. No. Reference numeral 4 denotes a sticking state detection device in which a P-polarization filter is provided in both the light projecting system and the light receiving system. Table 1 shows an example of contrast ratio measurement in these four apparatuses.

  As shown in FIG. 3 and Table 1, no polarizing filter is provided. 1, that is, in the conventional pasting state detection device, the contrast ratio was -0.033. In contrast, No. 1 provided with a polarizing filter. 2-No. The absolute value of the contrast ratio of 4 is at least 0.578. As described above, if a polarizing filter is provided between the light source 2 and the pasting location or between the pasting location and the image pickup device 3, the sheet material detection accuracy is further enhanced as compared with the conventional pasting state detection device. I understand that.

  In addition, No. 1 in which a polarizing filter is provided only in the light projecting system. No. 2 in which a polarizing filter is provided only in the light receiving system. The absolute value of the contrast ratio is larger in the sticking state detection device 3. Therefore, if a polarizing filter is provided in either one, it is preferable to provide a polarizing filter between the pasting location as the light receiving system and the imaging device rather than between the light source as the light projecting system and the pasting location. I can say that.

  Further, No. 1 is provided with polarizing filters in both the light projecting system and the light receiving system. No. 4 has the highest absolute value of the contrast ratio compared to other devices. Therefore, the detection accuracy of the sheet material can be further improved by arranging the P-polarization filter that transmits only the light of the P-polarized component in both the light projecting system and the light receiving system.

<2. Second Embodiment>
Next, with reference to FIG.4 and FIG.5, the 2nd Example of the sticking state detection apparatus of this invention is described.
FIG. 4 is a front view schematically showing the sticking state detection device according to the second embodiment, and FIG. 5 is a graph showing the value of the contrast ratio depending on the type of the polarizing filter.

  The sticking state detection device 11 according to the second embodiment is a device that detects the sticking state of the ACF 108 by detecting scattered light from the conductive particles dispersed in the ACF 108. As illustrated in FIG. 4, the pasting state detection device 11 includes a light source 12 that irradiates light to a spot where the ACF 108 is pasted, an imaging device 13 that captures light reflected from the pasting location, and an image connected to the imaging device 13. The processing device 14 and two polarizing filters 15 and 16 are included.

  The light source 12 is disposed at a position inclined by a predetermined angle θ from a position substantially perpendicular to the pasting location. That is, the light source 12 is set so that light is incident on the pasted portion at a predetermined angle θ. In the second embodiment, as in the first embodiment, the light source 12 is disposed at a position inclined by about 60 °. Here, the 1st polarizing filter 15 is arrange | positioned between the light source 12 and the sticking location, and has transmitted only the light which has a specific polarization component among the lights irradiated from the light source 12. FIG.

  Moreover, as shown in FIG. 4, the imaging device 13 is arrange | positioned in the substantially perpendicular | vertical position with respect to the sticking location. This point is greatly different from the first embodiment shown in FIG. And the 2nd polarizing filter 16 is arrange | positioned between this imaging device 13 and a sticking location, and the imaging device 13 is specific polarization | polarized-light among the lights reflected from the sticking location via this 2nd polarizing filter 16. FIG. Only the component light is detected.

  One of the first polarizing filter 15 and the second polarizing filter 16 is an S-polarizing filter that transmits only the light of the S-polarized component that exists in a plane orthogonal to the P-polarized component. The other is a P-polarized filter that transmits only the P-polarized component light. That is, the first polarizing filter 15 and the second polarizing filter 16 are set so as to transmit only light having different components when incident and when reflected. That is, incident polarized reflected light is not detected.

  For example, when a P-polarization filter is used for the first polarization filter 15 and an S-polarization filter is used for the second polarization filter 16, P-polarized light transmitted through the first polarization filter 15 is incident on the affixed portion. Is done. And in the location which has not stuck ACF108, it reflects as P-polarized light.

  Here, the second polarizing filter 16 uses an S polarizing filter whose polarization direction is 90 ° different from that of the first polarizing filter 15. For this reason, the light reflected as P-polarized light cannot pass through the second polarizing filter 16. As a result, the portion where the ACF 108 is not attached is projected darkly.

  On the other hand, at the place where the ACF 108 is pasted, the light incident from the light source 12 is scattered by the conductive particles dispersed in the ACF 108. Therefore, the light incident as P-polarized light can be transmitted through the second polarizing filter 16, which is an S-polarized filter, because the direction of the light is directed to various directions by the conductive particles. Therefore, the portion where the ACF 108 is pasted is projected brightly. As a result, the absolute value of the contrast ratio of the light becomes large at the location where the ACF 108 is affixed and at the location where the ACF 108 is not affixed, and the detection accuracy of the ACF 108 can be increased.

  Since other configurations are the same as those of the pasting state detection apparatus 1 according to the first embodiment described above, description thereof is omitted.

Next, an example of measuring the contrast ratio according to the difference between the types of the first and second polarizing filters will be described with reference to FIG.
FIG. 5 is a graph showing the difference in contrast ratio depending on the type of polarizing filter.

  First, the pasting state detection apparatus used for this measurement will be described. No. Reference numeral 5 denotes a conventional pasting state detection device that is not provided with a polarizing filter. No. Reference numeral 6 denotes a sticking state detection device using S polarizing filters for both the first and second polarizing filters 15 and 16. No. 7 is an example of a sticking state detection apparatus using an S polarization filter as the first polarization filter 15 and a P polarization filter as the second polarization filter 16.

  No. 8 is an example of a sticking state detection device using a P polarizing filter as the first polarizing filter 15 and an S polarizing filter as the second polarizing filter 16. Furthermore, no. 9 is an example of a sticking state detection device using P polarization filters for both of the two polarization filters 15 and 16.

  As shown in FIG. No. 5 and No. 5 provided with the same type of polarizing filter as the two polarizing filters. 6, no. In the sticking state detection device of No. 9, the absolute value of the contrast ratio is small. On the other hand, the first and second polarizing filters 15 and 16 use different types of polarizing filters. 7 and no. 8 shows that the absolute value of the contrast ratio is large. The numerical data of one measurement example is shown in Table 2.

  That is, when the same type of polarizing filter is provided for the first and second polarizing filters 15 and 16, the polarization direction of the light that can be transmitted on the light projecting side and the light receiving side is the same, so the ACF 108 is not attached. The light at the location can also pass through the second polarizing filter 16. Therefore, it is considered that the absolute value of the contrast ratio has decreased. On the other hand, in the second embodiment of the present invention, different types of polarizing filters are provided on the light projecting side and the light receiving side, so that the portion where the ACF 108 is not applied is darkened as described above, and the ACF 108 is darkened. It is possible to brighten the location where the is attached. As a result, it is considered that the absolute value of the contrast ratio could be increased.

  Also with the sticking state detection device 11 having such a configuration, the same operations and effects as those of the sticking state detection device 1 according to the first embodiment described above can be obtained.

  In the second embodiment, the case where the imaging device 13 is disposed at a position substantially perpendicular to the pasting location has been described. However, the present invention is not limited to this. That is, the imaging device 13 detects scattered light of light incident from the light source 12 by the conductive particles dispersed in the ACF 108. Therefore, the imaging device 13 is not limited to a substantially vertical position of the pasting location, and may be disposed at a position where scattered light can be detected.

  The application state detection device 11 according to the second embodiment is effective for detecting the application state of a sheet material having particles that disperse light such as conductive particles in the sheet, such as the ACF 108.

  The present invention is not limited to the embodiment described above and shown in the drawings, and various modifications can be made without departing from the scope of the invention described in the claims. For example, in the above-described embodiment, an example in which the ACF is applied as an application state detection device that detects a state in which the ACF is attached to a printed board has been described. However, the present invention is not limited to this. For example, it may be used in an application state detection device that detects the application state of a laminate in a laminate packaging of food, or may be used in an application state detection device that detects the application state of various other transparent or translucent sheet materials. .

  DESCRIPTION OF SYMBOLS 1,11 ... Adhesion state detection apparatus 2,12 ... Light source 3,13 ... Imaging apparatus 4,14 ... Image processing apparatus 5,15 ... 1st polarizing filter 6,16 ... 2nd polarizing filter, DESCRIPTION OF SYMBOLS 100 ... Liquid crystal display panel, 106 ... PCB (attachment object), 108 ... ACF (sheet material)

Claims (6)

An application state detection device for detecting an application state when applying a transparent or translucent sheet material to an object to be applied,
A light source for irradiating light to a pasting location where the sheet material is pasted on the adherend;
An imaging device for photographing the light reflected from the pasting location;
A polarizing filter provided between at least one of the light source and the pasting location, or between the pasting location and the imaging device;
An application state inspection device characterized by comprising: The sticking state inspection device according to claim 1, wherein the polarizing filter is disposed both between the light source and the sticking place and between the sticking place and the imaging device. The sticking state detection device according to claim 1, wherein the polarization filter is a P polarization filter that transmits only light of a P polarization component. The light source is set so that light is incident at an approximate Brewster angle of the P-polarized light of the sheet material with respect to the pasting location,
The said imaging device is set so that it may image | photograph the light reflected by the substantially Brewster angle of the P polarization of the said sheet material from the said sticking location. Affixing state detection device. 3. One of the two polarizing filters is an S-polarizing filter that transmits only light of an S-polarized component, and the other is a P-polarizing filter that transmits only light of a P-polarized component. The sticking state detection device according to 1. The sticking state detecting device according to claim 5, wherein the imaging device is arranged at a position substantially perpendicular to the sticking location.

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