JPH0934372A - Sticking device for anisotropic conductive tape and method for inspecting sticking state - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sticking device for an anisotropic conductive tape which can decides the sticking state of an ACF stuck on the electrode of a display panel and an inspecting method for the sticking state. SOLUTION: After the ACF(anisotropic conductive tape) 15 is stuck on the electrode 14 of the transparent plate 12a of the display panel, a camera 27 is positioned above the ACF 15 and the ACF is irradiated with light from a light source 26 below it. Its transmitted light is inputted to the camera 27 to obtain a histogram of the luminance of the transmitted light. The transparent plate 12a, the ACF 15, and a separator 16 stuck on the ACF 15 have characteristic light transmission characteristics respectively and then the peak value and distribution frequency of the histogram of the luminance obtained by the camera 27 are analyzed to easily and accurately decide whether or not there are the ACF 15 and separator and whether or not the electrode 14 is stained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sticking device and a sticking state inspection method for an anisotropic conductive tape for sticking a driver for driving the display panel.

[0002]

2. Description of the Related Art A display panel, which is often used as a display for electronic devices such as personal computers and word processors, is formed by laminating two transparent plates. Further, electrodes are formed at a narrow pitch on the edge thereof, and leads of a large number of drivers are connected to the electrodes.

As a method for connecting the driver, a method using an anisotropic conductive tape (hereinafter referred to as ACF) is generally used. ACF is an adhesive tape, and a separator is attached to the surface thereof for the convenience of handling and management. This separator is usually stripped and collected from the ACF immediately before connecting the driver.

In order to connect the driver to the display panel and assemble correctly, the ACF must be properly attached on the electrodes at the edge of the display panel, and the separator must be attached before connecting the driver. It must be completely stripped from the ACF. Therefore, the display panel is inspected for the ACF attachment state. Conventionally, this inspection has been performed by visual inspection by an operator.

[0005]

However, the visual inspection by the operator does not improve the work efficiency, and it is easy to make an inspection error.

By the way, fine conductive particles are mixed in the ACF, and the separator is generally opaque or translucent. The glass plate to which the ACF is attached is transparent. That is, the ACF, the separator, the transparent plate, and the like have unique light transmission characteristics.

Therefore, the present invention has been made in view of the above circumstances, and a sticking device and sticking device for an anisotropic conductive tape capable of optically inspecting the sticking state of the ACF by utilizing the above-mentioned light transmission characteristics. It is an object of the present invention to provide a method of inspecting the wearing condition.

[0008]

To this end, the AC of the present invention is used for this purpose.
The sticking device of F includes a movable table portion for positioning the display panel, a sticking unit for sticking an anisotropic conductive tape having a separator stuck on the surface of an electrode of the display panel, and an anisotropic conductive tape. It is provided with a peeling unit for peeling the upper separator, a light source for radiating light toward the edge of the display panel, and a camera for receiving the light to obtain a luminance histogram.

In the method for inspecting the adhered state of ACF of the present invention, light is emitted from the light source toward the edge of the display panel, a histogram of the brightness of the light is obtained by the camera, and the histogram of the brightness is analyzed. I did it. Further, the peak value of the histogram and its distribution frequency are analyzed.

[0010]

According to the above construction, the adhered state of the ACF can be accurately determined from the histogram of the brightness of the light transmitted through the ACF, particularly the appearance of the peak of the histogram.

[0011]

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view of an ACF attaching apparatus according to an embodiment of the present invention, and FIGS. 2 and 3 are side views of the same. In FIG. 1, 11 is a display panel, and two transparent plates 12
It is made by pasting a and 12b together. Although not shown in the figure, liquid crystal is sealed between the transparent plates 12a and 12b. A large number of electrodes 14 are formed at a narrow pitch on the edge of the transparent plate 12a. As will be described later, this electrode 14
The ACF 15 is attached on top.

Reference numeral 20 denotes a movable table section, which is constructed by stacking an X table 21, a Y table 22, a plate 13, a θ (rotation) table 23, and a holding table 24, and the display panel 11 has a holding table 24. It is positioned on top. When the movable table section 20 operates, the display panel 11 moves in the X direction, Y direction, and θ direction. A bracket 25 is provided on the plate 13 on the side of the Y table 22, and a linear light source 26 is held on the bracket 25 (see also FIG. 3). The display panel 11 is positioned on the holding table 24 so that the edge of one side thereof is along the light source 26. In FIG. 3, the light emitted from the light source 26 passes through the edge of the transparent plate 12a, and the light is incident on the camera 27 above.

Next, the ACF attaching unit and the separator peeling unit will be described. In FIG. 1, reference numeral 30 denotes an ACF sticking unit, which is configured as follows. Reference numeral 31 denotes a main body case as a supply unit of the ACF, in which a supply reel around which the ACF 15 is wound is housed, and the ACF 15 is led out from an opening at the bottom thereof. The supply reel is wound with the ACF 15 and the separator in two layers, and the drawn ACF 1
A separator is attached to the surface of No. 5. A chuck unit 32 has a pair of upper and lower chuck claws 32a. The slider 3 is provided on the back surface of the chuck unit 32.
4 are coupled to each other, and the slider 34 is slidably fitted to a horizontal guide rail 35. The chuck unit 32 is guided by a guide rail 35 by a drive mechanism (not shown).
The front end portion of the ACF 15 is chucked by the chuck claw 32a along the direction of the main body case 31. Next, the chuck unit 32 retracts along the guide rail 35, and the AC
A predetermined length of F15 is derived from the body case 31.

Reference numeral 36 denotes an AC derived from the main body case 31.
The suction head located above F15,
Have 7. The suction head 36 is held by the block 38. The suction head 36 moves up and down by the vertical movement mechanism of the block 38. The upper portion of the block 38 is slidably fitted to the guide rail 39,
The block 38 slides along the guide rail 39 by a drive mechanism (not shown). Reference numeral 33 denotes a scissor-type cutter arranged at the lead-out portion of the ACF 15 of the main body case 31, and cuts the ACF 15 led out of the main body case 31 by the chuck unit 32 into a predetermined length.

Reference numeral 40 denotes a peeling unit composed of a sub case 41 provided on the side of the sticking unit 30. As shown in FIG. 2, a supply reel 43 around which the adhesive tape 42 is wound and a take-up reel 44 around which the adhesive tape 42 is wound are housed inside the sub case 41. A roller 45 is axially attached to the lower portion of the sub case 41, and the adhesive tape 42 goes around the roller 45. The camera 27 described above is held on the front surface of the sub case 41. A slider 46 is coupled to the upper portion of the sub case 41. The slider 46 slides along the guide rail 47. As a result, the sub case 41 and the camera 27 horizontally move above the edge of the display panel 11 by a drive mechanism (not shown). It should be noted that description of a power unit such as a motor and an electric circuit for operating each unit is omitted.

The ACF sticking device is constructed as described above, and the ACF sticking operation will be described below. In FIG. 1, the movable table portion 20 is operated to move the edge portion of one side of the display panel 11 below the sticking unit 30. Next, the chuck unit 32 chucks the tip of the ACF 15 drawn out from the main body case 31 with the chuck claws 32 a, and retracts along the guide rail 35 so that A
A predetermined length of CF15 is derived.

Next, the suction head 36 receives the derived AC.
By moving above F15 and descending there, the ACF 15 is vacuum-adsorbed on the lower surface of the adsorbent 37, and
The cutter 33 cuts the ACF 15 into a predetermined length. Next, the suction head 36 is provided with the laminated ACF 15 and separator 16
Is picked up and moved along the guide rail 39 to above the edge of the display panel 11. Next, the ACF 15 which descends there and is vacuum-adsorbed on the lower surface of the adsorber 37 is attached to the electrode 14, and then the vacuum adsorption state is released to remove the adsorption head 3
6 rises, retracts along the guide rail 39, and returns to the initial position. By repeating the above operation, the ACFs 15 are sequentially attached to the edge portion of one side of the display panel 11.

AC for the edge of one side of the display panel 11
When the attachment of F15 is completed, the θ table 23 is driven to horizontally rotate the display panel 11 by 90 °. Then, the ACF 15 is attached to the edge portions of the other sides by the same operation as that described above. Generally, the display panel 11 is
The ACF 15 is attached to the edges of the three sides.

After the ACF 15 is adhered to the display panel 11, the separator 16 on the ACF 15 is peeled off. FIG. 2 shows the stripping operation of the separator 16. As shown in the figure, the sticking unit 30 is used for the transparent plate 12a.
A separator 16 is attached on the ACF 15 attached on the top. The separator 16 must be stripped prior to bonding the driver leads to the ACF 15.

Then, the roller 45 projecting from the lower surface of the sub case 41 is pressed against the separator 16 so that the sub case 4
1 is moved to the right along the guide rail 47. At this time, the supply reel 43 and the take-up reel 44 are rotated in the arrow direction, and the adhesive tape 42 is rotated in the arrow direction. Then, the separator 16 on the ACF 15 is transferred to the adhesive tape 42 and peeled off from the ACF 15. In FIG. 2, the ACF 15 at the left end shows the separator 16 that has been stripped off.

By the above operation, A on the display panel 11
After all the separators 16 on the CF 15 have been stripped off, the ACF 15 attached state is next inspected. FIG. 3 shows the situation. In this case, as shown in the figure, the camera 27 is positioned above the ACF 15, light is emitted from the light source 26 to pass through the transparent plate 12a and the ACF 15, and the camera 27 receives the light. While the camera 27 linearly moves along the guide rail 47 above the edge of the transparent plate 12a,
The transmitted light of each ACF 15 is received one after another.

Next, an algorithm for inspecting the attachment state of the ACF will be described. FIG. 4 to FIG. 8 are explanatory views of an algorithm for inspecting an ACF attachment state according to an embodiment of the present invention. In each figure, (a) is a histogram of luminance,
(B) is a partial cross-sectional view of the transparent plate 12a and the ACF 15.

Now, FIG. 4 shows the ACF 15 on the transparent plate 12a.
Indicates that there is no. In this case, most of the light emitted from the light source 26 (see the arrow) passes through the transparent plate 12a and enters the camera 27. Therefore, the luminance histogram is as shown in FIG. a is the peak value of luminance, and t1 is the distribution frequency thereof. In this case, the peak value a is substantially equal to the peak value of the brightness of the light source 26.

FIG. 5 shows a case where the ACF 15 does not exist on the transparent plate 12a and the stain K on the surface of the transparent plate 12a is severe. In this case, since the brightness decreases due to the stain K, there is no particular peak in the histogram, and the distribution frequency is approximately uniform at about t2.

FIG. 6 shows the case where the separator 16 is present on the ACF 15 (that is, the separator 16 shown in FIG. 2).
If the stripping is not successful). The separator 16 is opaque and does not transmit the light emitted from the light source 26, but the ambient light (natural light or indoor illumination light) is slightly reflected on the surface of the separator 16 as shown by the broken line arrow and enters the camera 27. To do. Therefore, the luminance histogram is as shown in FIG. b is a peak value of luminance, which is extremely low, and its distribution frequency is t3.

FIG. 7 shows the case where the ACF 15 is attached to the transparent plate 12a. In this case, the peak value of the brightness of the light (arrow A) transmitted through the transparent base material of the ACF 15 is a, and the peak value of the brightness of the light (arrow B) emitted by the conductive particles 15a is c. Therefore, two peak values a and c appear in the histogram as shown in FIG. t4, t
5 is each distribution frequency, and t4> t5.

FIG. 8 shows the case where the ACF 15 is attached to the relatively dirty transparent plate 12a and the electrode 14. In this case, the peak of a does not exist clearly due to the stain K, and c
There is only the peak of. The distribution frequency t6 is substantially equal to the distribution frequency t4 in FIG.

As shown in FIGS. 4 to 8, the appearance of the luminance peak value and the distribution frequency of the luminance histogram varies depending on the dirt state of the electrode 14, the presence or absence of the ACF 15, the presence or absence of the separator 16. Therefore, each state can be determined by analyzing the appearance of the peak value of luminance and the distribution frequency. This analysis and determination can be automatically performed at high speed by a computer. Specifically, for example, the peak value and the distribution frequency of each of the typical examples shown in FIGS. The registered value is determined. 4 to 8 show typical examples, and needless to say, there are other examples than those shown in FIGS. 4 to 8.

FIG. 9 is an analysis / determination diagram of the adhered state of the ACF of one embodiment of the present invention, which summarizes the analysis results shown in FIGS. There are three adhesion states: normal (with ACF), separator peeling error, and no ACF.
It is divided into 6 categories, each with no stain and with stain. For each category, a unique peak value of the brightness appears, which allows the adhered state to be accurately determined. The drawing numbers (FIGS. 4 to 8) corresponding to each category are entered in each category. As is apparent from FIG. 9, the appearance of the two peak values b and c is particularly useful as a parameter for determining the adhered state.

Next, an example of the overall flow will be described. FIG. 10 is a flowchart of the ACF sticking process according to an embodiment of the present invention, and FIG. 11 is a flowchart of the ACF sticking state inspection process. In step 1 of FIG. 10, AC
F15 is cut into a predetermined length and attached to the display panel 11. Next, in step 2, the separator 16 on the ACF 15 is peeled off.

Next, in step 3, the adhering state of the ACF 15 is determined by the method shown in FIGS. FIG. 11 shows the detailed flow thereof. First, in step 3-1,
The camera 27 observes the edge of the display panel 11 to capture the recognition image. Next, in step 3-2, the peak value and the peak distribution degree value of the histogram of the luminance distribution are checked.

Next, in step 3-3, it is determined whether or not the peak value b exists near the separator brightness. If No, then in step 3-4, the peak value c near the ACF brightness is obtained.
It is determined whether or not exists. That is, in this method, in steps 3-3 and 3-4, the appearance of the peak values b and c is checked to determine the pasting state.

If Yes in step 3-4, it is determined in step 3-5 whether or not the ACF brightness number is larger than t4, and if Yes, the pasting state is good (step 3-
6). If No in steps 3-4 and 3-5, the process proceeds to step 3-8. As a result, the determinations shown in FIGS. 7 and 8 can be performed.

Next, if Yes in step 3-3, it is determined in step 3-7 whether the separator luminance number is larger than t3. If No, the pasted state is bad, which corresponds to the case of FIGS. 4 and 5 (step 3-8), and if Yes, peeling is bad, and the case of FIG. 6 corresponds (step 3-8). 3-9). Step 3-10
Then, it is determined whether or not the above-described inspection is repeated.

When the ACF attachment state inspection process of step 3 is completed as described above, the process proceeds to step 4 of FIG. Then, it is determined whether or not the pasted state is all good, and if Yes, the display panel is carried out to the next step in step 7. On the other hand, if No in step 4, the process proceeds to steps 5 and 6 to retry.

[0036]

According to the present invention, the light transmitted through the electrodes of the display panel is received by the camera, and the histogram of the luminance is obtained and analyzed, whereby the presence or absence of the ACF or the separator can be determined quickly and surely. it can. In particular, an accurate determination can be made by analyzing the appearance of peaks in the histogram.

[Brief description of drawings]

FIG. 1 is a perspective view of an ACF attaching apparatus according to an embodiment of the present invention.

FIG. 2 is a partial side view of an ACF attaching device according to an embodiment of the present invention.

FIG. 3 is a partial side view of an ACF sticking device according to an embodiment of the present invention.

FIG. 4 is an explanatory diagram of an algorithm for inspecting an ACF attachment state according to an embodiment of the present invention.

FIG. 5 is an explanatory diagram of an algorithm for inspecting an ACF attachment state according to an embodiment of the present invention.

FIG. 6 is an explanatory diagram of an algorithm for inspecting the adhered state of the ACF according to the embodiment of the present invention.

FIG. 7 is an explanatory diagram of an algorithm for inspecting the attachment state of the ACF according to the embodiment of the present invention.

FIG. 8 is an explanatory diagram of an algorithm for inspecting the attachment state of the ACF according to the embodiment of the present invention.

FIG. 9 is an analysis / determination diagram of an ACF attachment state according to an embodiment of the present invention.

FIG. 10 is a flowchart of an ACF attaching process according to an embodiment of the present invention.

FIG. 11 is a flowchart of an inspection process of an ACF attachment state according to an embodiment of the present invention.

[Explanation of symbols]

 11 Display Panels 12a and 12b Transparent Plate 14 Electrode 15 ACF 16 Separator 20 Movable Table Part 26 Light Source 27 Camera 30 Adhesive Unit 31 Main Body Case 32 Chuck Unit 32a Chuck Claw 33 Cutter 40 Peeling Unit

Claims (3)

[Claims] 1. An anisotropic conductive tape sticking device for sticking an anisotropic conductive tape to an electrode formed on an edge of a display panel, which is formed by sticking transparent plates together, and positioning the display panel. A movable table section, a sticking unit for sticking an anisotropic conductive tape having a separator stuck on the surface of a display panel electrode, a peeling unit for peeling the separator on the anisotropic conductive tape, and a display panel An anisotropic conductive tape sticking apparatus, comprising: a light source that emits light toward the edge of the sheet and a camera that receives the light and obtains a histogram of luminance. 2. A method for inspecting an adhered state of an anisotropic conductive tape adhered to an electrode formed on an edge portion of a display panel, which is formed by laminating transparent plates, comprising: a light source and an edge portion of the display panel. A method for inspecting the adhered state of an anisotropic conductive tape, which comprises irradiating light toward, obtaining a brightness histogram of a light with a camera, and analyzing the brightness histogram. 3. The method for inspecting the adhered state of an anisotropic conductive tape according to claim 2, wherein the peak value of the histogram and its distribution frequency are analyzed.