JP2004012295A - Apparatus and method for inspecting bearing distribution sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem of pixel inspection by probing as a method for inspecting pixel defects in a bearing distribution sensor that an apparatus is expensive and that throughput is not improved. <P>SOLUTION: The inspection apparatus to be used divides a counter electrode film into quarters; presses every divided area with a pad; and displays it on a screen. By performing inspection by division into quarters, it is possible to visually detect line defects and pixel defects in which unpressed parts are displayed. The apparatus is inexpensive, and inspection throughput is improved. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an inspection method and an inspection apparatus for a surface pressure distribution sensor suitable for detecting a fine uneven pattern such as a fingerprint pattern using a flexible conductive film.
[0002]
[Prior art]
As a device for detecting a fine concavo-convex pattern such as a fingerprint pattern, a surface pressure distribution sensor using a flexible conductive film and a thin film transistor (Thin Film Transistor) is disclosed in, for example, JP-A-6-288845.
[0003]
FIG. 17 shows an example of an active matrix type surface pressure distribution sensor for detecting a fingerprint pattern. 17A is a plan view, and FIGS. 17B and 17C are cross-sectional views taken along line DD of FIG. 17A.
[0004]
The conventional surface pressure distribution sensor 200 includes a substrate 201 such as glass or ceramic on which TFTs 204a serving as a large number of unit detection elements are formed, and a counter electrode film 202.
[0005]
The unit detection element 204 has a TFT 204a and a contact electrode 204b connected thereto. The unit detecting elements 204 are arranged in a matrix on a substrate 201 made of glass or the like, the active layer of the TFT constituting the unit detecting element 204 is an amorphous silicon film, and the contact electrode 204b is formed of ITO (Indium Tin Oxide). You.
[0006]
The counter electrode film 202 is provided to face the substrate 201, and has a structure in which a conductive film 202b is deposited on the back surface (TFT side) of the flexible insulating film 202a. The counter electrode film 202 is fixed by a sealant 203 applied around the substrate 201 and is arranged separately from the substrate 201.
[0007]
An example of a method for manufacturing the surface pressure distribution sensor will be described. After forming the TFT 204 a on the substrate 201, a sealing agent 203 made of a low-temperature thermosetting resin is applied around the substrate 201 in order to attach the counter electrode film 202. After that, the counter electrode film 202 of the substrate 201 is attached and heat treatment is performed. As a result, the substrate 201 and the counter electrode film 202 are fixed.
[0008]
FIG. 17C shows an example of detecting a fingerprint pattern using the surface pressure distribution sensor.
[0009]
When the finger F is placed on the surface pressure distribution sensor 200 and pressed lightly, the entire counter electrode film 202 is pressed down. However, when closely observed, the pressing force is different between the peak portion and the valley portion of the fingerprint. The contact electrode 204b of the unit detection element 204 located immediately below or very close to the portion is in electrical contact with the counter electrode film 202. However, the contact electrode 204b of the unit detection element 204 located immediately below or near the valley of the fingerprint does not make electrical contact with the counter electrode film 202. As described above, a signal at a portion where the counter electrode film 202 and the unit detection element 204 are in contact with each other is extracted to detect a fingerprint pattern.
[0010]
[Problems to be solved by the invention]
It is known that a surface pressure distribution sensor using a TFT can be realized by the above structure and manufacturing method. However, when the surface pressure distribution sensor is mass-produced, a method for inspecting the surface pressure distribution sensor has not been established, and an efficient inspection apparatus and inspection method have been demanded.
[0011]
[Means for Solving the Problems]
The present invention has been made to solve the problems, and has a mounting portion for a surface pressure distribution sensor, and a pad portion having an area smaller than the measurement region of the surface pressure distribution sensor, and a plurality of pads for one measurement region. This is a surface pressure distribution sensor inspection device that presses and presses a pad portion to observe the output of the surface pressure distribution sensor during pressurization.
[0012]
Further, the measurement area of the surface pressure distribution sensor is rectangular, and the pad portion is a rectangle larger than a rectangle obtained by dividing the measurement area into four parts and smaller than the measurement area.
[0013]
Further, it has a monitor for displaying the output of the surface pressure distribution sensor during pressurization.
[0014]
Further, the surface pressure distribution sensor has the substrate and the counter electrode film fixed with a predetermined gap therebetween, and the contact surface of the pad portion with the surface pressure distribution sensor has irregularities larger than the gap of the surface pressure distribution sensor. It is smooth to the extent that it does not.
[0015]
Further, the contact surface with the pad surface pressure distribution sensor has a hardness of 10 degrees or more and 100 degrees or less.
[0016]
Further, the mounting section has a control means which is movable in the horizontal direction with the surface pressure distribution sensor mounted and moves the pad section up and down.
[0017]
Further, the control means presses the pad portion with a pressure of ² kg / cm ² or less against the measurement region.
[0018]
Further, the control means presses the pad portion at a speed of 10 mm / sec or less.
[0019]
In addition, the pressure is sequentially applied to an area smaller than the measurement area of the surface pressure distribution sensor, the output of the surface pressure distribution sensor is observed each time, and the inspection method of the surface pressure distribution sensor that observes the entire measurement area by applying the pressure multiple times. It is.
[0020]
Further, rectangular pads larger than the rectangle obtained by dividing the measurement area into four and smaller than the measurement area are sequentially pressed.
[0021]
Further, the pad portion is pressed against the counter electrode film at a pressure of ² kg / cm ² or less.
[0022]
Further, the pad portion is pressed at a speed of 10 mm / sec or less.
[0023]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail.
[0024]
1 to 3 are overall views of a surface pressure distribution sensor 100 according to the present invention, FIG. 1 is a plan view thereof, FIG. 2 is a sectional view taken along line AA of FIG. 1, and FIG. 3 is an exploded perspective view.
[0025]
The surface pressure distribution sensor 100 has a structure in which a substrate 1 and a counter electrode film 2 made of a flexible conductive film are fixed with a sealant 3. A large number of unit detection elements 4 are arranged in a matrix on the inside of the substrate 1 surrounded by the sealant 3. The flow stopping means 5 is arranged along the inner periphery of the sealant 3, and a contact 6 is arranged between the sealant 3 and the flow stopping means 5. External connection terminals 7 are arranged on one side of the substrate 1.
[0026]
In the present embodiment, the substrate 1 is made of glass, but may be another insulating substrate such as quartz, ceramic, plastic, or a semiconductor substrate.
[0027]
The counter electrode film 2 has a structure in which a conductive film 2b of a metal such as gold is deposited on the back surface (TFT side) of a flexible insulating film 2a such as PET (polyethylene terephthalate) or PEN (polyethylene naphthalate).
[0028]
The sealant 3 is a thermosetting resin which is liquid before being cured and is cured by heating.
[0029]
The unit detection element 4 has a TFT 4a as a switching element and a contact electrode 4b connected to the TFT 4a. The active layer of the TFT 4a is a silicon film, particularly preferably a polysilicon film. Hereinafter, the switching element will be described using a TFT as an example. However, the switching element is not limited to the TFT. For example, if the substrate 1 is a semiconductor substrate, a transistor using the semiconductor substrate 1 as an active layer or a thin film diode may be used. The contact electrode 4b is a conductive film formed on an insulating film covering the TFT 4a, and is formed of, for example, ITO (Indium Tin Oxide).
[0030]
The flow stopper 5 is made of the same thermosetting resin as the sealant 3. The flow stopping means 5 will be described later in detail.
[0031]
The contact 6 is provided to apply a GND potential to the counter electrode film 2, and is disposed between the sealant 3 and the flow stopping means 5. The contact 6 is made of a contact resin 6b made of a thermosetting resin mixed with Au pearl on a contact pad 6a made of Al.
[0032]
The external terminal 7 is connected to an external circuit by connecting an unillustrated FPC (Flexible Printed Circuit) or the like.
[0033]
As shown in FIG. 3, gate lines 8 and drain lines 9 are arranged on the substrate 1 in a matrix. As will be described later, a gate signal is applied to the gate line 8 and a scanning signal is applied to the drain line 9. TFTs 4a are arranged corresponding to the intersections of the gate line 8 and the drain line 9, respectively. The gate electrode is connected to the gate line 8, the drain terminal is connected to the drain line 9, and the source terminal is connected to the contact electrode 4b. Wiring (not shown) for transmitting various signals input to the gate line 8, the drain line 9, and the like are collected on the side edge of the substrate 1 and connected to the external connection terminal 7.
[0034]
Next, the unit detection element 4 will be described in detail with reference to FIG. FIG. 4A is a plan view of one unit detection element 4, and FIG. 4B is a cross-sectional view taken along line CC of FIG. 4A. The same reference numerals as those in FIG. 1 indicate the same components.
[0035]
In the TFT 4a of the unit detection element 4, an active layer 11 made of a polysilicon layer is formed on the substrate 1, and an impurity is introduced by a known method to form a source region S and a drain region D. A gate insulating film 12 is formed to cover the entire surface of the active layer 11, and a gate electrode 8a is formed thereon. The gate electrode 8a is formed integrally with the gate line 8. An interlayer insulating film 13 is provided on the gate electrode 8a, the drain terminal D of the active layer 11 is connected to the drain line 9 via a contact hole, and the source terminal S is connected to the extraction electrode 9a. The extraction electrode 9a is made of, for example, Al in the same layer as the drain line 9. A flattening film 14 is further laminated thereon to flatten the unevenness of the lower layer. On the flattening film 14, a contact electrode 4b made of ITO which is in contact with the extraction electrode 9a via a contact hole is arranged.
[0036]
Next, the operation of the surface pressure distribution sensor 100 of the present invention will be described with reference to FIG. FIG. 5A shows a state in which the finger F is placed on the surface pressure distribution sensor 100, and FIG. 5B is a circuit conceptual diagram of the surface pressure distribution sensor 100.
[0037]
When the finger F is placed on the surface pressure distribution sensor 100 and pressed lightly, the entire counter electrode film 2 is pushed down as shown in FIG. At this time, since the pressing force is different between the peak portion and the valley portion of the fingerprint, the counter electrode film 2 immediately below the peak portion or in the immediate vicinity thereof is largely dented, and is not largely dented at the valley portion. Therefore, the contact electrode 4b of the unit detection element 4 corresponding to the peak position contacts the conductive film 2b of the counter electrode film 2, and the contact electrode 4b of the unit detection element 4 corresponding to the valley position contacts the conductive film 2b. do not do.
[0038]
The conductive film 2b of the counter electrode film 2 is grounded via the resistor 15. The drain line 9 of the surface pressure distribution sensor 100 is connected to an X-direction register 70, and the gate line 8 is connected to a Y-direction register 80. The scanning signal is sequentially switched from the Y-direction register 80 to the gate line 8 at a predetermined timing and output. Now, it is assumed that a gate signal of a certain potential (“H” level) is applied to a certain gate line 8. The TFTs 4a connected to the gate line 8 to which the gate signal has been applied are all turned on (ON). In the meantime, the scanning signal is sequentially switched and applied to the drain line 9 from the X-direction register 70 at a predetermined timing.
[0039]
When the counter electrode film 2 is curved by the peak of the finger F and is in contact with the contact electrode 4b, even if the voltage once rises as a scanning signal, the current drops through the TFT 4a and the resistor 15, so the voltage drops. . When the counter electrode film 2 is not in contact with the contact electrode 4b at the valley of the finger F, the voltage of the scanning signal is maintained without lowering. When this is read as a voltage signal by the detector 16, the surface pressure distribution for one row can be measured. Then, a gate signal is applied by sequentially switching the gate lines 8 to be selected, signals from all the unit detection elements 4 of the surface pressure distribution sensor 100 are read, and the surface pressure distribution over the entire surface can be measured.
[0040]
The detector 16 may be a voltage measuring device branched from the drain line 9 and connected as described above, or may be a current measuring device inserted in series with the drain line 9. Since this can be simplified, the present embodiment employs a voltage measuring device.
[0041]
Next, a gap between the substrate 1 and the counter electrode film 2 shown by G in FIG. 2 will be described. First, when the gap G is 10 μm or less, a problem due to a narrow gap may occur. That is, when the opposing electrode film 2 is attached, as shown in FIG. 6A, the probability of close contact near the center increases. Further, when the counter electrode film 2 is attached, the variation in the amount of air sealed therein becomes large, and thus the variation in sensing sensitivity increases. Conversely, when the gap G is 40 μm or more, as shown in FIG. 6B, the amount of air to be enclosed is too large, and the counter electrode film 2 does not come into contact with the unit detection element 4 even when pressed with a finger. Is reduced. Therefore, it is feasible if the gap G is 10 μm to 40 μm. If the gap G is small, the sensing sensitivity is high (the fingerprint can be detected even if the gap G is weakened), and if the gap G is large, the variation in the sensing sensitivity is small. Since the counter electrode film 2 is flexible, if the tension (tension) is low, the counter electrode film 2 is always in contact with the unit detection element 4 even if the finger F is not pressed, resulting in a failure. If there is only a small area of constant contact (called fine contact), pressing the finger F causes the counter electrode film 2 to bend along the finger F, so that there is no problem in sensing the fingerprint. After this, the pressure is detected, which is a problem in product quality. When the gap G was about 10 μm, the frequency of the occurrence of the fine contact was high. For this reason, it is desirable that the gap G be 15 μm or more. In this embodiment, 25 μm is adopted as the optimum value.
[0042]
Here, the gap 25 μm between the gaps G is extremely large, for example, as compared with the substrate gap 6 to 7 μm of an LCD (Liquid Crystal Display). Normally, in an LCD, a gap material called micropearl is sprayed over the entire surface between substrates in order to make the substrate spacing uniform. However, in the surface pressure distribution sensor 100 of the present embodiment, since the counter electrode film 2 and the unit detection element 4 need to be in contact with each other, the gap material cannot be sprayed.
[0043]
As described above, since the gap material scattered over the entire surface between the substrates of the LCD cannot be used, the gap G must be secured by the sealant 3. Usually, in an LCD, a ball-shaped gap material is mixed in a seal. However, in this embodiment, since the gap G is extremely large, 25 μm, a gap material having the same diameter as that used for LCDs and having a diameter of 25 μm is not generally available. Of course, it is not impossible to make it by custom order, but it was judged that a ball-shaped gap material having a large diameter had a large variation in diameter and was unsuitable. Therefore, in the present embodiment, the gap G is fixed by mixing a cylindrical resin fiber having a diameter of 25 μm and a length of 45 μm to 50 μm into the sealant 3. The resin fiber is different from the ball-shaped gap material in the manufacturing method, and has a small diameter error of about 25 μm ± 0.3 μm, and is optimal.
[0044]
Of course, the gap G of 15 μm or less and 10 μm or more may be used as long as sensitivity is given priority while ignoring close contact or fine contact between the substrate and the counter electrode film. In this case, a resin fiber of 15 μm or less and 10 μm or more may be employed.
[0045]
Next, a method for manufacturing the surface pressure distribution sensor 100 of the present invention will be described with reference to FIGS.
[0046]
Step 1: FIG. 7A shows a state in which a plurality of surface pressure distribution sensors 100 are simultaneously formed on the mother glass 1, and FIG. 7B is a cross section showing one unit detection element. FIG. By simultaneously forming the plurality of surface pressure distribution sensors 100 from one mother glass, the manufacturing cost of the surface pressure distribution sensor can be reduced. First, a buffer layer made of a silicon oxide film and a silicon nitride film (not shown) is formed on the mother glass 1. Next, an amorphous silicon film is deposited and crystallized by laser annealing to form a polysilicon film. Next, a gate insulating film 12 is formed, a metal film made of chromium is formed and etched to form a gate line 8, a gate electrode 8a connected thereto, and an external connection terminal 7 not shown. Next, using the gate electrode 8a as a mask, an impurity is introduced by a known method to form the source region S and the drain region D, and the active layer 11 is formed. Next, an interlayer insulating film 13 is formed, a contact hole is formed at a predetermined position, and a drain line 9, an extraction electrode 9a, and a contact pad 6a (not shown in FIG. 7) around the substrate are formed. The contact pad 6a is provided by opening an interlayer insulating film 13 at a corner around the substrate 1, forms a contact 6 with a contact resin 6b provided in a later step, and applies a GND potential to the counter electrode film 2. is there. Further, a contact electrode 4b made of ITO is formed, and a number of unit detection elements 4 are formed on the substrate 1. Thereafter, the large-sized substrate 1 is scribed along a scribe line 50 and divided into individual substrates 1 serving as surface pressure distribution sensors.
[0047]
Step 2: Next, as shown in FIG. 8, a thermosetting resin is applied in a window frame shape surrounding the substrate 1 at a position separated from the end face of the substrate 1 by a predetermined distance. Next, heat treatment is performed at 70 ° C. for about 20 minutes to form the flow stopper 5 in a semi-cured state. Hereinafter, the heat treatment for forming the flow stopping means 5 is referred to as pre-bake. Further, in the present specification, the semi-cured state refers to a state in which the thermosetting resin has a viscosity of at least about 100 Pa · s and the viscosity of the thermosetting resin is at least twice the viscosity of the thermosetting resin before curing. If it is semi-cured, the resin will not flow due to capillary action.
[0048]
Step 3: Next, as shown in FIG. 9, a sealant 3 mixed with a fiber resin having a diameter of 25 μm is applied around the outside of the flow stopping means 5. Further, in order to form the contact 6, a thermosetting resin mixed with a metal ball for the contact resin 6b is potted at a corner on the contact pad 6a outside the flow stopping means 5. As the metal ball, Au pearl having a uniform particle shape (AU-230, 30 μm, manufactured by Sekisui Chemical Co., Ltd.) is preferable. Au pearl is a powder in which a resin sphere such as plastic is coated with a metal film such as Au, and the shape of each particle is uniform. For example, when the contact 6 is formed with an Ag paste, the shape of the Ag powder is sharp and the diameter varies, so that there is a possibility that the ITO is deteriorated. In addition, by using Au pearl, the resistance is reduced, and the resistance of the contact 6 can be reduced even in a small area. As the resin that becomes the base material of the contact 6 and the sealant 3, a low-temperature curable resin is used.
[0049]
Step 4: Next, as shown in FIG. 10, a plurality of substrates 1 are arranged in one direction in a nitrogen atmosphere containing no water, and are arranged in one direction so that the external connection terminals 7 are exposed from the substrate 1. The counter electrode film 2 having a long length is placed on the counter electrode film 2, and is moved on the counter electrode film 2 while rotating the roller 51, and is simultaneously attached to a plurality of substrates. By using the long counter electrode film 2 in one direction, it is possible to pressurize the long counter electrode film 2 while giving an appropriate tension (tension), and to apply the pressure while rotating the roller 51 under the conditions described later. Excess air between the substrate 1 and the counter electrode film 2 is released by the pressure of the roller 51. Next, heat treatment is performed at 90 ° C. for about 30 minutes while the low-temperature thermosetting resin as the sealant 3 is fully cured while applying a load to cure the resin of the contact resin 6b and the sealant 3, and the counter electrode film 2 and the substrate At the same time, a contact 6 for connecting the contact pad 6a and the counter electrode film 2 is formed. At the same time, the flow stopping means 5 is fully cured in a squashed form, and the shape is fixed. In this specification, this heat treatment is referred to as main bake. At this time, the gap G between the substrate 1 and the counter electrode film 2 is optimized according to the diameter of the fiber resin by the main bake under load. In the case of the present embodiment, it is 25 μm. Finally, the counter electrode film is divided into individual pieces in accordance with the substrate 1 to complete the surface pressure distribution sensor 100. The low-temperature curable resin is used for the sealant 3 and the contact 6 because the heat-resistant temperature (softening temperature) of PET used for the flexible insulating film 2a of the counter electrode film 2 is about 120 ° C., and more. This is because the heat treatment cannot be performed.
[0050]
Next, the flow stopping means 5 will be described. Usually, in the LCD, the flow stopping means 5 is not formed, and both substrates are fixed by the sealant 3 only. However, since the surface pressure distribution sensor needs to fix the flexible counter electrode film 2, the flow stopping means 5 is required. FIG. 11 is a cross-sectional view when the sealant 3 is formed without forming the flow stopping means 5. First, as shown in FIG. 11A, the sealing agent 3 is applied on the substrate 1. Next, the counter electrode film 2 is disposed in an overlapping manner. Since the thermosetting resin before curing has a low viscosity, as shown in FIG. It was found that a capillary phenomenon occurred during the process, and the sealant 3 itself entered the central portion of the sensor, resulting in a failure. Therefore, the flow stopping means 5 is provided beforehand inside the sealant 3 to prevent the capillary phenomenon from occurring, thereby preventing the sealant 3 from entering the inside and improving the yield.
[0051]
Further, when the counter electrode films 2 are arranged one on top of the other, another problem occurs even if the capillary phenomenon does not occur well. That is, when the thermosetting resin is cured by heating, the solvent evaporates to generate gas. Part of this gas was sealed in the surface pressure distribution sensor, making it difficult to control the amount of air to be sealed, causing variations in sensing sensitivity and, in the worst case, widening the contact area, making it impossible to perform sensing. . Therefore, in step 2 described above, after the flow stopping means 5 is applied, semi-curing is performed by pre-baking. The gas escapes from the flow stopping means 5 by the pre-bake before the counter electrode film 2 is disposed in an overlapping manner, and the gas generated from the sealant 3 and the contact resin 6b in the main bake after the counter electrode film 2 is disposed in the pre-bake. It is prevented from being sealed inside the sensor.
[0052]
It is possible to reduce the generation of gas by heat-treating the sealant 3 once without forming the flow stopping means 5 and then performing heat treatment for further hardening. However, since the heat-resistant temperature of the flexible insulating film forming the counter electrode film is low, it is necessary to use a low-temperature thermosetting resin as the sealant. Therefore, even in the first heat treatment, the curing of the resin proceeds, and in the heat treatment of the main curing, the bonding strength of the counter electrode film is significantly reduced, and the yield is reduced or the life of the sensor is shortened. Problem arises. On the other hand, in the present embodiment, since the flow stopping means 5 is pre-baked and the sealing agent 3 is separately provided, the bonding strength does not decrease. In addition, since the sealant 3 can be formed to the entire outer shape of the substrate 1, higher bonding strength can be secured.
[0053]
Here, it is necessary to prevent the pre-baking for semi-curing the flow stopping means 5 from reaching the main curing. If the flow stopping means 5 is completely cured by pre-baking, the flexibility of the flow stopping means 5 will be lost when the counter electrode film 2 is attached in a later step, and the gap G will be reduced to the height of the resin of the flow stopping means 5. This is because they depend on them. Since it is necessary to eliminate the fluidity before the counter electrode film 2 is stacked, the height of the flow stopping means 5 cannot be adjusted by suppressing the height from above, and is controlled only by the amount of the applied resin. Can not. Therefore, the height of the flow stopping means 5 at the semi-cured stage needs to be equal to or less than the final gap G, 25 μm in this embodiment. However, if the height of the flow stopping means 25 is too low, the occurrence of the capillary phenomenon cannot be suppressed. If it does not reach the full curing, it can be formed higher than the gap G and can be crushed in a later main bake process. Therefore, the gap G is determined by the fiber resin and the substrate 1 and the counter electrode film 2 are removed by eliminating the fluidity of the flow stopping means 5 and by setting the hardness to be crushed by pressurization during the main baking, that is, by semi-curing. Can be filled with the flow stopping means 5.
[0054]
The material of the flow stopper 5 may be any material such as a photo-curable resin or a resist as long as it has a certain degree of flexibility without flowing. It is good to If the same low-temperature curable resin as the sealant 3 is used, the affinity between the flow stopper 5 and the sealant 3 is good, and the curing conditions are the same, so that the contact 6 and the sealant 3 can be cured by one heating. Can be. Further, the sealant 3 and the flow stopping means 5 can be integrated. Thereby, the flow stopping means 5 also functions as a part of the sealant 3 after the main baking, and the seal width can be increased by 1.5 to 2 times. Therefore, the moisture resistance of the element such as the TFT 4 a formed on the substrate 1 can be improved. Performance can be improved. If the flow stopper 5 crushed by the roller remains semi-cured, the elastic force of the flow stopper 5 acts in the direction of peeling the counter electrode film 2. However, when the flow stopping means 5 is fully hardened by the main bake, no elastic force is generated, so that the yield can be improved. In addition, since the flow stopper 5 is also fully cured at the same time as the main curing of the sealant 3, a separate step of curing the flow stopper 5 is unnecessary.
[0055]
By the way, in a normal LCD, the contact 6 is formed using an Ag paste. Similarly, in the present embodiment, when a trial production was performed using an Ag paste for the contact resin 6b, conduction failure of the counter electrode film 2 occurred frequently. This is because the glass transition point of PET, which is the base material of the counter electrode film, is 67 ° C., and PEN is also 113 ° C., so that 90 ° C. for 30 minutes is employed as the main bake. The curing temperature of the Ag paste is 120 ° C. It is considered that the base material of the Ag paste did not reach full curing and the interface strength was deteriorated. Therefore, in the present embodiment, the same low-temperature thermosetting resin as that of the sealant 3 and the flow stopper 5 mixed with Au pearl is used as the contact resin 6b. By using the low-temperature curable resin for the contact resin 6b, the contact resin 6b can be surely cured, and sufficient interface strength can be obtained.
[0056]
FIG. 12 is a sectional view of a contact 6 part. This is a cross-sectional view taken along line BB of FIG. As shown in FIG. 12A, by providing the contact 6 inside the sealant 3, the contact 6 can be shut off from the outside air, so that the deterioration of the contact 6 can be prevented. Further, by providing the contact 6 outside the flow stopping means 5, it is possible to prevent the contact resin 6b before curing from entering the sensor portion. Therefore, the contact 6 is optimally provided between the flow stopper 5 and the sealant 3.
[0057]
Further, if the contact 6 is arranged inside the sealant 3, the conductive film 2b of the counter electrode film 2 can be extended to the inside of the sealant 3 as shown in FIG. By removing and fixing the conductive film 2b at the position corresponding to the sealant 3, the flexible insulating film 2a made of PET or PEN is exposed, and if the sealant 3 is directly fixed thereto, the flexible A peeling field between the substrate 1 and the counter electrode film 2 due to film peeling between the conductive insulating film 2a and the conductive film 2b is prevented, and the reliability can be further improved. Since the contact pads 6a formed on the substrate 1 are covered with the resin, the contact pads 6a are not exposed, and deterioration due to oxidation or the like can be prevented.
[0058]
Next, the roller 51 used in Step 4 will be described. First, as a material of the roller 51, a material having a hardness of 50 degrees or more, such as a silicone resin, a polycarbonate, an ABS resin, or the like is desirable, and the optimal one is about 50 degrees to 150 degrees. Further, ceramic, metal, glass, etc. may be used, and a material having a certain degree of hardness is preferable in order to accurately control the air. If the soft material has a hardness of less than 50 degrees, the roller 51 will bend, and the control of the air amount will be inaccurate.
[0059]
The pressure roller 51 is set to 2 to 1000 g / cm ² of about 100 g ^/ cm, the speed of the rollers is preferably 5mm / s~50mm / s. Further, the tension of the counter electrode film 2 at the time of sticking is optimally about 100 g to 3000 g.
[0060]
Next, the counter electrode film 2 needs an optimal tension for sensing. The counter electrode film 2 has flexibility, and the filling is gas. In particular, since the finger slides during sensing as shown in FIG. 13, unnecessary bending 150 occurs in the counter electrode film 2 due to insufficient tension, and optimal sensing may not be performed. In this case, after sticking, the flexible conductive film (PEN or PET) is contracted by a heat treatment to perform a treatment for obtaining an optimal tension (hereinafter, this heat treatment is referred to as a shrinkage bake in the present specification). The shrinkage baking for shrinking the base material is performed for a short time at a temperature equal to or higher than the glass transition temperature of the flexible insulating film 2a and lower than the softening point. In particular, it is preferable that the temperature be higher by 10 ° C. to 20 ° C. than the glass transition temperature. For example, since the glass transition temperature is 113 ° C. for PEN and 80 ° C. for PET, heat treatment is performed at a temperature higher by 10 ° C. to 20 ° C. than that temperature for about 3 minutes. By shrinkage baking, the substrate of the flexible insulating film 2a is shrunk by about 1% to 3%, and a process for obtaining an optimum tension without unnecessary bending even when sliding is performed. If the shrinkage is excessive, the flexible conductive film 2 becomes hard, so that it is preferable to keep it to about 2%.
[0061]
Next, between the counter electrode film 2 and the substrate 1, dry air from which water has been removed or nitrogen gas may be sealed. If the internal air contains moisture, the TFT 4a is always exposed to this air atmosphere, which causes deterioration and characteristic shift. Therefore, in the present embodiment, a nitrogen gas containing no water is sealed in a space surrounded by the counter electrode film 2, the substrate 1, and the sealant 3. This can prevent the TFT 4a from deteriorating due to moisture and shifting characteristics. Here, the gas to be sealed is not limited to nitrogen, and may be any inert gas that does not react with the structure on the substrate 1 or the surface of the counter electrode film 2. Dry air may be used as a gas that avoids intrusion of moisture into the TFT 4a and does not promote the reaction, but nitrogen is preferable because oxygen is mixed therein. Further, a gas composed of a so-called inert element such as Ar, Ne, Kr or the like may be used, but in the present embodiment, nitrogen which can be implemented at lower cost is adopted.
[0062]
Further, piezoelectric particles whose resistance value changes depending on the pressure may be scattered in the inert gas, and the resistance value of the piezoelectric particles may be reduced by the external pressure to make the counter electrode film 2 and the TFT 4a conductive. The TFT 4a may be electrically connected to the counter electrode film 2 by external pressure.
[0063]
Next, an inspection method and an inspection apparatus for the surface pressure distribution sensor will be described. FIG. 14 shows an example of an inspection device 150 for inspecting the finished surface pressure distribution sensor 100 for quality. The inspection device 150 includes a mounting portion 151 for the surface pressure distribution sensor 100, a pad portion 152 for applying pressure to the counter electrode film of the surface pressure distribution sensor 100, and a monitor portion 153 for displaying an image of the surface pressure distribution sensor 100. And a control means 154 for moving the pad section 152 up and down.
[0064]
The mounting section 151 is a table on which the surface pressure distribution sensor 100 is mounted. A hole (not shown) is opened at the center of the mounting portion 151, and the surface pressure distribution sensor 100 is fixed by suction from the hole. The mounting section 151 can move in the plane direction of the surface pressure distribution sensor 100 while the surface pressure distribution sensor 100 is fixed.
[0065]
The pad part 152 is a silicone resin having a rectangular contact surface smaller than the measurement area 2 'of the surface pressure distribution sensor, as shown in FIG. The size of the pad section 152 is a rectangle larger than the measurement area 2 ′ of the surface pressure distribution sensor divided into four and smaller than the measurement area 2 ′.
[0066]
The measurement area 2 ′ here refers to an area to be inspected. As shown in FIG. 3, in the surface pressure distribution sensor 100 of the present embodiment, the matrix of the unit detection elements 4, the X-direction register 70, and the Y-direction register 80, and the counter electrode film 2 faces the entire surface thereof. . In the counter electrode film 2, the area where the unevenness can be sensed is only the matrix area of the unit detection element 4, and the portion corresponding to the X-direction register 70 and the Y-direction register 80 cannot be sensed even if the finger F is pressed. . Therefore, the area to be inspected is an area where irregularities can be sensed, and in the case of the surface pressure distribution sensor 100 of the present embodiment, it is a matrix area of the unit detection elements 4. As a product incorporating the surface pressure distribution sensor 100, for example, when the surface pressure distribution sensor 100 is housed in a housing that covers the periphery of the matrix area of the unit detection element 4, the The portion exposed from the housing is the measurement area 2 '. In such a case, as a manufacturer of the surface pressure distribution sensor 100, the measurement area 2 'is the quality assurance area.
[0067]
The monitor unit 153 displays an output image of the surface pressure distribution sensor 100 pressed by the pad unit 152 during the inspection. That is, at the time of inspection, the shape of the pad section 152 is displayed on the monitor section as it is, so that if there is a defective section, it can be easily recognized.
[0068]
The control means 154 can move the pad section 152 up and down at a predetermined speed and pressure set in advance.
[0069]
Next, the pad section 152 will be described in more detail. As described above, the surface of the pad 152 that contacts the counter electrode film 2 is smaller than the counter electrode film 2 so that the entire surface is not covered by the pad 152. This is because, when the surface pressure distribution sensor 100 is pressurized by the pad portion 152 covering the entire surface, there is no escape for the air sealed in the surface pressure distribution sensor, and there is a risk that the surface pressure distribution sensor will burst. In addition, as will be described in detail later, the inspection is also performed by pressing down the area divided into four parts of the counter electrode film by the pad part 152. For this reason, the sensor contact surface of the pad part 152 is about 2 to 5 mm larger in each of the vertical and horizontal directions of the measuring area 2 ′ of the surface pressure distribution sensor than in the vertical and horizontal directions (shown by broken lines in FIG. 14B). It is a rectangle.
[0070]
Next, as the material of the pad portion 152, a silicone resin having a hardness of 10 to 30 degrees was adopted. This material may be any material as long as it has a hardness of 10 degrees or more and 100 degrees or less. If the hardness is 100 degrees or more, the surface pressure distribution sensor 100 detects irregularities on the surface of the pad portion 152, and therefore, it is necessary to press uniformly with a certain soft material. When a material having a higher hardness is used, it is preferable that the surface accuracy (the size of the surface unevenness) of the pad portion 152 be equal to or less than the gap G, that is, 25 μm or less.
[0071]
Next, an inspection method of the surface pressure distribution sensor by the inspection device of the present invention will be described with reference to FIGS.
[0072]
First, the surface pressure distribution sensor 100 is set on the mounting portion 151, and is fixed by suction. As shown in FIG. 14, the mounting portion 151 is moved so that two sides of the measurement region 2 ′ and one corner sandwiched between the two sides coincide with those of the pad portion 152. FIG. 14 shows a state where the upper left corner is matched.
[0073]
Next, as shown in FIG. 15, the controller 154 lowers the pad section 152 at a speed of 10 mm / sec, contacts the surface pressure distribution sensor 100, and pressurizes the pad section at a pressure of 1.7 kg / cm ² . Then, the surface pressure distribution sensor 100 detects the pad section 152, and the image is displayed on the monitor 153. Since the pad section 152 uniformly presses the pressurized area 155, all the unit detection elements 4 in the pressurized area 155 are turned on, and the monitor 153 displays the pressurized area 155 in black on a white background of the measurement area 2 ′. Is displayed.
[0074]
Next, the control device 154 raises the pad section 152, and the mounting section 151 moves the relative position of the pad 152 to the position indicated by the arrow a so that the pad section 152 matches the upper right corner of the measurement area 2 ′. Perform similar measurements.
[0075]
Similarly, by moving the arrow b to the lower right corner and moving it to the arrow c to measure the lower left corner, the entire measurement area 2 'is measured. Since the pad section 152 is larger than the area obtained by dividing the measurement area 2 ′ into four, the measurement is always performed at the center of the measurement area 2 ′.
[0076]
The surface pressure distribution sensor 100 detects a signal at a portion where a pressure is applied to the counter electrode film 2 and the contact electrode of the TFT and the counter electrode film 2 are electrically contacted. Defects in this case include an OFF defect in which a signal is detected even though the contact is made, and an ON defect in which a signal is detected even though the contact is not made.
[0077]
For example, FIG. 16 shows an example of the inspection. Here, it is assumed that the inspection area 155 that is normally in contact with the monitor 153 is displayed in black on the white background screen by pressing the pad section 152 on the white background screen. For example, consider a case where there is one unit detection element for each of the off-defect and the on-defect. In this case, since the defect occurs in one unit detection element, it becomes a point defect. As shown in FIG. 16A, when an off defect exists in the inspection area 155, a white circle is recognized as an off point defect 160a. If an ON defect exists in a portion where the pad 152 does not contact, a black circle is recognized as the ON point defect 160b.
[0078]
In addition, an on-line defect in which current always flows through the drain line due to a short circuit of the wiring, and an off-line defect due to disconnection of the gate line and the drain line occur. On-line defects include those that always appear and those in which all of the rows or columns are detected due to current leakage when a specific defect unit detection element 160 (x mark) is pressed. If a line defect has occurred, as shown in FIG. 16B, it is recognized as an on-line defect 161a in which all rows are turned on and an off-line defect 161b in which all rows are turned off. Since the pad section 152 has an area corresponding to four divisions, for example, when the defective section 160 (marked by “x”) is pressed by the pad section 152, all of the one column (or row) having the defective pixel is displayed as a black line defect 161. Will be done. Here, the broken line portion of the line defect 161 overlaps with the pad portion 152 and thus cannot be actually recognized. However, the line defect 161 can be recognized outside the inspection area 155.
[0079]
Here, for the purpose of comparison, a case is considered where, for example, the counter electrode film 2 is divided into two and inspected by pressing twice. It is assumed that an on-line defect has occurred due to a leak of the defect unit detecting element 160 as shown in FIGS. While no pressure is applied by the pad section 152, no leak occurs, so that an on-line defect is not recognized. Then, even if the pressure is applied by the pad 152, the case where all of the on-line defects overlap the pressed area 155 is not recognized at all. Further, when the entire surface is pressed by using the large pad portion 152 covering the entire measurement area 2 'as shown in FIG. 16E, a line defect cannot be detected, and a portion which is not pressed as shown in FIG. In this case, it is impossible to detect a defect (black circle) that is in contact.
[0080]
As is apparent from the above description, in the present embodiment, the counter electrode film 2 is divided into four parts, and each area is pressurized by the pad part 152 to display a part which does not contact with a part which should electrically contact. And defects of all patterns can be visually recognized.
[0081]
In addition to displaying the image on the monitor unit 153 and visually recognizing the image, the output image of the surface pressure distribution sensor 100 may be input to an information processing device such as a computer (not shown), and the inspection may be automatically performed by image recognition. . In this case, it is more preferable that the information processing apparatus controls the movement of the mounting unit 151, the vertical movement of the control unit 154, and the image capture.
[0082]
Next, the pressure and the pressing speed of the pad section 152 will be described. For example, in the case where dust is mixed between the counter electrode film 2 and the substrate 1, if the pressure is too high, the dust is also pressed down, and it becomes difficult to detect the dust. Conversely, even if the pressure is too weak, the electrical contact between the contact electrode 40 and the counter electrode film 2 is not complete. For example, in order to uniformly press the counter electrode film 2 with the head portion 152 having a hardness of 20 degrees, the pressure needs to be ² kg / cm ² or less. In the present embodiment, the pressure is 1.7 kg / cm ^2. And Further, since the detection state of the foreign matter differs depending on the pressing speed, the pressing is performed at a speed of 10 mm / sec or less. Since the throughput increases as the pressing speed increases, the speed is set to 10 mm / sec in this embodiment.
[0083]
According to the present invention, an inexpensive and high-speed inspection apparatus can be provided as compared with an apparatus that detects the position of a defective pixel by probing, for example.
[0084]
In the above-described embodiment, the pad section 152 is illustrated as being coincident with each corner. However, for example, when the periphery of the measurement area 2 is hidden by the housing, it is not necessary to inspect the area. It is not necessary to completely coincide with the corner, and it may be arranged slightly inside the corner, or may be arranged slightly outside the corner in order to more reliably inspect the periphery.
[0085]
Also, the monitor 153 may display the pressing portion in black on a white background, or may display the pressing portion in another color such as displaying on a black background.
[0086]
【The invention's effect】
As described above, according to the present invention, the pad portion is pressed and pressed, and the output of the surface pressure distribution sensor during the pressurization is observed, so that a defect can be visually recognized. As compared with a device or the like for detecting the position of the inspection device, an inspection device in which the components are inexpensive and the operation is simple can be provided.
[0087]
In addition, since the measurement area is inspected in a plurality of times, for example, an on-line defect is recognized as a defect in a non-pressed area, and an off-line defect is recognized as a defect in a non-pressed area. As described above, since the portions that should be in electrical contact and the portions that do not contact can be displayed, defects in all patterns can be visually recognized, and there is an advantage that the reliability is high and the throughput is improved.
[0088]
Further, by setting the pressure to 2 kg / cm ² or less and the pressing speed to 10 mm / sec or less, there is an advantage that optimum detection can be performed.
[Brief description of the drawings]
FIG. 1 is a plan view for explaining the present invention.
FIG. 2 is a cross-sectional view for explaining the present invention.
FIG. 3 is an exploded perspective view for explaining the present invention.
4A is a plan view and FIG. 4B is a cross-sectional view for explaining the present invention.
5A is a sectional view for explaining the present invention, and FIG. 5B is an operation circuit diagram.
FIG. 6 is a cross-sectional view illustrating the present invention.
FIG. 7 is a sectional view illustrating the present invention.
FIG. 8 is a plan view illustrating the present invention.
FIG. 9 is a plan view illustrating the present invention.
FIG. 10 is a plan view illustrating the present invention.
FIG. 11 is a cross-sectional view illustrating the present invention.
FIG. 12 is a cross-sectional view illustrating the present invention.
FIG. 13 is a cross-sectional view illustrating the present invention.
14A and 14B are a schematic diagram and a plan view illustrating the present invention.
15A and 15B are a schematic diagram and a plan view illustrating the present invention.
FIG. 16 is a plan view illustrating the present invention.
17A is a plan view, FIG. 17B is a cross-sectional view, and FIG. 17C is a cross-sectional view for explaining a conventional technique.

Claims (12)

A mounting portion for the surface pressure distribution sensor,
Having a pad portion having an area smaller than the measurement region of the surface pressure distribution sensor, and pressing the pad portion against a single measurement region multiple times to apply pressure,
A surface pressure distribution sensor inspection device for observing an output of the surface pressure distribution sensor during pressurization. The measurement area of the surface pressure distribution sensor is rectangular,
The surface pressure distribution sensor inspection device according to claim 1, wherein the pad portion is a rectangle larger than a rectangle obtained by dividing the measurement region into four parts and smaller than the measurement region. The inspection apparatus according to claim 1, further comprising a monitor unit that displays an output of the surface pressure distribution sensor during the pressurization. The surface pressure distribution sensor is formed by fixing a substrate and a counter electrode film with a predetermined gap therebetween,
2. The surface pressure distribution sensor according to claim 1, wherein a contact surface of the pad portion with the surface pressure distribution sensor is smooth so as not to have irregularities larger than a gap of the surface pressure distribution sensor. 3. Inspection equipment. The surface pressure distribution sensor inspection device according to claim 1, wherein a contact surface of the pad portion with the surface pressure distribution sensor has a hardness of 10 degrees or more and 100 degrees or less. The mounting unit is horizontally movable with the surface pressure distribution sensor mounted thereon,
The surface pressure distribution sensor inspection device according to claim 1, further comprising control means for moving the pad portion up and down. The surface pressure distribution sensor inspection apparatus according to claim 6, wherein the control unit presses the pad portion with a pressure of ² kg / cm ² or less with respect to the measurement area. The inspection apparatus according to claim 6, wherein the control unit presses the pad unit at a speed of 10 mm / sec or less. The pressure is sequentially applied to an area smaller than the measurement area of the surface pressure distribution sensor, the output of the surface pressure distribution sensor is observed each time, and the entire measurement area is observed by applying pressure a plurality of times. Inspection method of distribution sensor. The inspection method of the surface pressure distribution sensor according to claim 9, wherein a rectangular pad portion larger than a rectangle obtained by dividing the measurement region into four and smaller than the measurement region is sequentially pressed. The inspection method of a surface pressure distribution sensor according to claim 10, wherein the pad portion is pressed against the counter electrode film at a pressure of ² kg / cm2 or less. The inspection method of the surface pressure distribution sensor according to claim 10, wherein the pad portion is pressed at a speed of 10 mm / sec or less.

Images