KR20140058997A - Method for bonding pcb to substrate and device for sensing user input manufactured by the same - Google Patents

Abstract

The present invention relates to a method of bonding a flexible printed circuit board (PCB) to a substrate on which electrode pads and signal interconnections are disposed and a touch detecting device manufactured by the same. The method of boding a PCB to a substrate includes the steps of: forming a first arrangement mark on a substrate of a touch panel including a single layered electrode pads and signal interconnections formed of a transparent material; forming, on the PCB, a second arrangement mark corresponding to the first arrangement mark; detecting the first arrangement mark and the second arrangement mark and adjusting a position of at least one of the substrate and the PCB for allowing centers of the first and second arrangement marks to be matched; and electrically connecting the signal interconnections and interconnections of the PCB by matching the centers of the first and second arrangement marks.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a circuit board bonding method and a user input sensing apparatus,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circuit board bonding method and a user input sensing device manufactured thereby, and more particularly, to a method of bonding a flexible printed circuit board to a substrate on which electrode pads and signal lines are disposed, .

The touch panel is an input device that allows a user to input a command of a user by touching with a human hand or other contact means based on the content displayed by the video display device.

To this end, the touch panel is provided on the front face of the image display device and converts the contact position, which is directly in contact with a human hand or other contact means, into an electrical signal. Accordingly, the instruction content selected at the contact position is accepted as the input signal.

Since such a touch panel can replace an input device such as a keyboard and a mouse, its use range is gradually expanding.

As a method of implementing a touch panel, a resistive film type, a light sensing type, and a capacitive type are known. Among them, the capacitive touch panel converts the contact position into an electrical signal by sensing a change in the capacitance that the conductive sensing pattern forms with other peripheral sensing patterns or the ground electrode when a human hand or an object touches.

Here, in order to determine the contact position on the contact surface, the sensing pattern includes a first sensing pattern (X pattern) formed to be connected along the first direction and a second sensing pattern (Y pattern) formed to be connected along the second direction .

1 is an exploded plan view of a conventional touch panel.

The conventional touch panel 10 includes a transparent substrate 11, a first sensing pattern 12 formed in sequence on the transparent substrate 11, a first insulating layer 13, a second sensing pattern 14, a metal pattern 15, And a second insulating film 16.

The first sensing patterns 12 are formed to be connected to one surface of the transparent substrate 11 along a first direction. For example, the first sensing patterns 12 may be formed on the transparent substrate 11 in a regular pattern in which a plurality of diamond shapes are connected in a line.

The first sensing patterns 12 may be formed of a plurality of X patterns formed so that the first sensing patterns 12 located in one row having the same X coordinate are connected to each other.

The first sensing pattern 12 includes a pad 12a so as to be electrically connected to the metal pattern 15 on a row basis. The pads 12a of the first sensing patterns 12 may be formed in a row unit.

The second sensing patterns 14 are formed to be connected to the first insulating layer 13 along the second direction and alternately arranged with the first sensing patterns 12 so as not to overlap with the first sensing patterns 12. For example, the second sensing patterns 14 may be formed in the same diamond pattern as the first sensing patterns 12, and the second sensing patterns 14 located on one row having the same Y coordinate are connected to each other .

The second sensing pattern 14 includes a pad 14a so as to be electrically connected to the metal pattern 15 on a row-by-row basis. The pads 14a of the second sensing patterns 14 may be formed in units of rows.

The first and second sensing patterns 12 and 14 are made of a transparent conductive material such as indium tin oxide (ITO), and the first insulating layer 13 is made of a transparent insulating material.

Unit sensing patterns 12 and 14 are electrically connected to position detection lines (not shown), respectively, and supply contact position signals to a driving circuit (not shown) or the like.

When a hand or an object touches the touch panel 10 shown in Fig. 1, the first and second sensing patterns 12 and 14, the metal pattern 15, and the position detection line are connected to the driving circuit side, A change in capacity is delivered. The contact position is recognized as a change in capacitance is converted into an electrical signal by an X and Y input processing circuit (not shown) or the like.

However, in the conventional touch panel 10, each layer for X and Y must have an ITO pattern, and an insulating layer must be provided between the X layer and the Y layer, thereby increasing the thickness. In addition, since the touch detection can be performed by accumulating the change of the capacitance which is generated finely by the touch several times, the capacitance change should be detected at the high frequency. This requires complex computation and statistical processing.

In addition, the difference in electrical signals before and after the touch is extremely small, so that it is influenced by wiring resistance. Therefore, a metal wiring such as the metal pattern 15 is required to maintain a low resistance. An additional mask process is required to form such a metal pattern 15. [

Further, the touch detection of the conventional touch panel 10 greatly depends on the resistance value and is sensitive to noise, so there is a great difficulty in increasing the touch detection sensitivity.

Moreover, the conventional touch panel 10 can not calculate an accurate touch area because a touch is detected using a minute change of capacitance accumulated several times by complicated calculation. Therefore, it is practically impossible for the user to use the touch area as one means of user input.

2 is a plan view of a conventional touch sensing apparatus.

The metal wiring 15 connected to the first sensing pattern 12 and the second sensing pattern 14 is electrically connected to the circuit board 20 on which the driving device 21 can be formed, .

As a general method used for connecting the metal wiring 15 and the circuit board 20, a conductive adhesive / adhesive tape such as ACA (anisotropic conductive adhesive) or ACF (anisotropic conductive film), which is anisotropic conductive, And a method of connecting by a pin connector are known.

In the case of a method of bonding by a conductive adhesive / adhesive tape or a method of connecting by a pin connector, various alignment devices and methods for adjusting the circuit board 20 and the metal wiring 15 to be properly connected are used.

However, since the width of the metal wiring 15 is very thin to the extent of several micrometers to several tens of micrometers, the position of the metal wiring 15 is accurately adjusted to be connected to the wiring 22 of the circuit board 20 It is difficult to do.

If the metal wiring 15 is not correctly connected to the wiring 22 of the circuit board 20 and a disconnection occurs, malfunction or failure may occur.

Therefore, there is a need for an effective method of grasping and bonding the wiring 22 of the circuit board 20 and the metal wiring 15 of the touch panel to an accurate connection position.

In order to solve the above problems, the present invention has been made to solve the above-mentioned problems occurring in the prior art, and it is an object of the present invention to provide a circuit board bonding method for bonding a flexible printed circuit board and a touch screen panel, Device.

According to an aspect of the present invention, there is provided a method of manufacturing a touch panel including: forming a first alignment mark on a substrate of a touch panel including an electrode pad and a signal line formed of a transparent material in a single layer; Forming a second alignment mark on the circuit board corresponding to the first alignment mark; Detecting the first alignment mark and the second alignment mark and adjusting a position of at least one of the substrate and the circuit board so that the center of the first alignment mark and the center of the second alignment mark coincide with each other; And aligning the first alignment mark and the second alignment mark so that the signal wiring and the wiring of the circuit board are electrically connected to each other.

In one embodiment of the present invention, the electrode pad, the signal wiring, and the first alignment mark may be made of the same material.

In one embodiment of the present invention, the same material may be indium-tin oxide (ITO).

In an embodiment of the present invention, the first alignment mark and the second alignment mark may be detected by UV light or LED light to be irradiated.

In an embodiment of the present invention, the second alignment mark may be made of the same material as the wiring of the circuit board.

In one embodiment of the present invention, after the step of forming the second alignment mark, an anisotropic conductive film may be disposed between the substrate and the circuit board.

In one embodiment of the present invention, the plurality of electrode pads are provided, and each of the plurality of electrode pads is disposed in an isolated matrix shape, and the signal wiring may be more than the number of the electrode pads.

According to an embodiment of the present invention, there is provided a touch panel including a substrate on which a transparent electrode pad and a signal line are disposed in a single layer and a first alignment mark is formed; And a circuit board on which a second alignment mark corresponding to the first alignment mark is formed, wherein at least one of the substrate and the circuit board detects the first alignment mark and the second alignment mark, The position of the alignment mark is adjusted so that the center of the second alignment mark is aligned with the alignment mark, and the signal wiring and the wiring of the circuit board are electrically connected to each other.

In one embodiment of the present invention, the electrode pad, the signal wiring, and the first alignment mark may be made of the same material.

In an embodiment of the present invention, the first alignment mark and the second alignment mark may be detected by UV light or LED light to be irradiated.

In one embodiment of the present invention, the plurality of electrode pads are provided, and each of the plurality of electrode pads is disposed in an isolated matrix shape, and the signal wiring may be more than the number of the electrode pads.

According to the present invention, a first alignment mark is formed on the substrate and a position is detected by the first optical device, a second alignment mark is formed on the circuit board and the position is detected by the second optical device, Since at least one of the positions can be adjusted, the signal wiring of the substrate and the wiring of the circuit board can be adjusted to the correct connecting position.

Further, according to the present invention, since the first alignment marks can be made of ITO like the electrode pads and the signal wirings, the first alignment marks can be formed at the same time when the electrode pads and the signal wirings are formed, The process may not be added.

It should be understood that the effects of the present invention are not limited to the above effects and include all effects that can be deduced from the detailed description of the present invention or the configuration of the invention described in the claims.

1 is an exploded plan view of a conventional touch panel.
2 is a plan view of a conventional touch sensing apparatus.
3 is a view illustrating an example of a user input sensing apparatus manufactured by a circuit board bonding method according to an embodiment of the present invention.
4 is a plan view illustrating a state of a user input sensing device before and after bonding by a circuit board bonding method according to an embodiment of the present invention.
5 is an exemplary view showing an example in which a circuit board bonding method according to an embodiment of the present invention is executed.
6 is a flowchart illustrating a circuit board bonding method according to an embodiment of the present invention.
7 is a block diagram of a touch sensing apparatus according to an embodiment of the present invention.
8 is an equivalent circuit diagram of a touch cell according to an embodiment of the present invention.
9 is a waveform diagram of a touch cell according to an embodiment of the present invention.
10 is a schematic block diagram of a touch cell and a detection unit according to an embodiment of the present invention.
11 is a graph for explaining the operation of the detector according to an embodiment of the present invention.
12 is a graph showing a voltage difference between a touch cell and a reference cell as a function of a touch capacitance according to an embodiment of the present invention.
13 is a schematic diagram for explaining a correspondence relationship between a touch cell and a memory in a touch sensing apparatus according to an embodiment of the present invention.
14 is a flowchart illustrating a method of calculating a contact area and a contact position according to an embodiment of the present invention.
15 to 18 are views showing in detail a method of calculating the contact area and the contact position according to the embodiment of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The above and other features and advantages of the present invention will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings in which: FIG. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In order to clearly illustrate the present invention, parts not related to the description are omitted, and similar parts are denoted by like reference characters throughout the specification.

Throughout the specification, when an element is referred to as "comprising ", it means that it can include other elements as well, without excluding other elements unless specifically stated otherwise.

Also, the terms " part, "" module, " and " module" in the specification mean units for processing at least one function or operation, Lt; / RTI >

Throughout the specification, when a part is referred to as being "connected" to another part, it includes not only a direct connection but also a connection with another system in the middle.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 3 is a view illustrating an example of a user input sensing device manufactured by a circuit board bonding method according to an embodiment of the present invention. FIG. 4 is a schematic view of a circuit board bonding method according to an embodiment of the present invention, FIG. 5 is a diagram illustrating an example of a circuit board bonding method according to an embodiment of the present invention. Referring to FIG.

3 to 5, the user input sensing device may include a touch panel and a circuit board 200.

The touch panel includes a plurality of electrode pads 110 formed on a substrate 100 such as a transparent glass or plastic film, and a plurality of signal wires 120 connected to the electrode pads 110.

The electrode pad 110 may be formed of a transparent material in a single layer.

The plurality of electrode pads 110 may be, for example, rectangular or rhombic, but are not limited thereto. The electrode pads 110 may be formed in a polygonal shape having a uniform shape. The electrode pads 110 may be arranged in the form of a matrix of substantially adjacent polygons.

Each signal line 120 has one end connected to the electrode pad 110 and the other end extending to the lower edge of the substrate 100. The line width of the signal line 120 can be designed to be quite narrow to the order of several to several tens of micrometers.

The electrode pad 110 and the signal line 120 may be made of a transparent conductive material such as ITO (Indium Tin Oxide), IZO (indium-zinc-oxide), CNT (carbon nanotube), or graphene . Since the electrode pads 110 of the touch panel according to the embodiment of the present invention are respectively connected to the signal lines 120, That is, the number of signal lines 120 is equal to or greater than the number of electrode pads 110. In addition, the signal line 120 is formed of the same transparent conductive material on the same layer as the electrode pad 110. As described above, it is impossible to visually align a plurality of signal wirings 120 made of a transparent material having a fine line width to wirings of the circuit board 200.

The electrode pad 110 and the signal wiring 120 can be simultaneously formed by, for example, laminating an ITO film on the substrate 100 by a method such as sputtering, and then patterning using an etching method such as photolithography.

The electrode pad 110 and the signal wiring 120 may be covered with a transparent insulating film (not shown).

A first alignment mark 310 may be formed on the substrate 100.

Here, at least one first alignment mark 310 may be formed on one surface of the substrate 100. For example, one or more first alignment marks 310 may be formed on the lower surface of the substrate 100 at regular intervals.

The first alignment mark 310 may be formed in such a shape that the center can be grasped easily, but is not limited to any specific shape. For example, the first alignment mark 310 may be formed in a polygonal shape, and the inside of the first alignment mark 310 may not be filled.

In addition, the first alignment mark 310 may be formed of the same material as the electrode pad 110 and the signal line 120. For example, the first alignment mark 310 may be made of ITO.

Since the first alignment mark 310 is made of the same material as the electrode pad 110 and the signal line 120 instead of the metal material, the first alignment mark 310 is formed by the electrode pad 110 and the signal line 120, The wiring 120 can be formed at the same time when the wiring 120 is formed, so that a new process can not be added.

A second alignment mark 320 may be formed on one surface of the circuit board 200. For example, the second alignment mark 320 may be formed on the upper surface of the circuit board 200.

Here, the circuit board 200 may be a printed circuit board, a flexible printed circuit board (FPCB), a flexible circuit film, or the like.

The second alignment mark 320 may be formed in a shape corresponding to the first alignment mark 310 and may correspond to a position corresponding to the first alignment mark 310.

The second alignment mark 320 is formed at a position where the signal wiring 120 of the substrate 100 is aligned with the wiring 290 of the circuit board 200, And the wiring 290 of the circuit board 200 are brought into the correct positions.

The first alignment mark 310 and the second alignment mark 320 are formed so that the center of the first alignment mark 310 and the center of the second alignment mark 320 are aligned, The wiring 120 and the wiring 290 of the circuit board 200 are matched with each other.

The second alignment mark 320 may be made of metal. The metal may include at least one of copper (Cu) and tin (Sn).

In addition, the second alignment marks 320 may be made of the same material as the wirings 290 of the circuit board 200. That is, the second alignment marks 320 can be formed at the same time when the wirings 290 of the circuit board 200 are formed without adding a separate process, so that the process is simplified and the manufacturing cost is minimized There is an advantage.

Then, the first alignment mark 310 can be detected by the first optical device 400.

To this end, the first optical device 400 may be positioned below the substrate 100, and the position of the first optical device 400 may be fixed at a predetermined position.

In addition, the second alignment mark 320 may be located by the second optical device 410, for which the second optical device 410 may be positioned above the circuit board 200, The position of the second optical device 410 can be fixed.

The first optical device 400 and the second optical device 410 can irradiate the substrate 100 and the circuit board 200 facing each other with the irradiation light that is UV light or LED light .

Here, the UV light may have a constant wavelength, for example, a wavelength of 405 nm.

When the irradiation light is irradiated on the substrate 100 and the circuit board 200 as described above, the pattern shapes of the first alignment mark 310 and the second alignment mark 320 are visible and the first optical device 400 and the second The position of the first alignment mark 310 and the second alignment mark 320 can be detected through the optical device 410. [

Based on the position of the first alignment mark 310 and the second alignment mark 320 thus determined, the position adjusting device 420 adjusts the position of at least one of the substrate 100 and the circuit board 200 .

That is, the position adjusting device 420 may move the substrate 100 only, move only the circuit board 200, or move both the substrate 100 and the circuit board 200 while moving the first alignment mark 310 ) And the second alignment mark 320 are aligned with each other.

To this end, a controller 430 may be further provided to control the operation of the first optical device 400, the second optical device 410, and the position adjusting device 420.

The controller 430 receives the positional information of the first alignment mark 310 and the second alignment mark 320 detected through the first optical device 400 and the second optical device 410, And the position of the circuit board 200 can be grasped and the substrate 100 and the circuit board 200 can be adjusted in position by the control of the position adjusting device 420. [

With the above-described configuration, the plurality of signal wirings 120 having a transparent fine line width can be precisely aligned and bonded to the wiring of the circuit board 200.

4 (a), the substrate 100 and the circuit board 200 are separated from each other by the signal wires 120 of the substrate 100 and the circuit board 200, as shown in FIG. 4 (b) The wiring 290 of the circuit board 200 can be adjusted to the correct connecting position.

When the centers of the first alignment marks 310 and the second alignment marks 320 coincide with each other, the substrate 100 and the circuit board 200 can be fixed, And the wiring 290 of the circuit board 200 can be electrically connected.

An anisotropic conductive film 300 may be disposed between the signal wiring 120 of the substrate 100 and the wiring 290 of the circuit board 200. The anisotropic conductive film 300 may be an ACF (anisotropic conductive film). The anisotropic conductive film 300 is placed between the substrate 100 and the circuit board 200 and then thermocompressed to electrically connect the signal wires 120 and the wires 290 of the circuit boards 200 .

6 is a flowchart illustrating a circuit board bonding method according to an embodiment of the present invention.

6, in the circuit board bonding method according to the embodiment of the present invention, a first alignment mark is formed on a substrate of a touch panel including an electrode pad and a signal line formed of a transparent material in a single layer (step S10 ) Can be made.

Here, the first alignment mark may be the same material as the electrode pad and the signal wiring, and may be, for example, ITO.

Then, a step S20 may be performed in which a second alignment mark corresponding to the first alignment mark is formed on the circuit board.

The second alignment mark may be made of the same material as the wiring of the circuit board and the second alignment mark may be formed in a shape corresponding to the first alignment mark and formed at a position corresponding to the first alignment mark.

Here, step S30 may be further performed in which an anisotropic conductive film is disposed between the substrate and the circuit board. Here, the anisotropic conductive film may be ACF.

In addition, the step of adjusting the position of at least one of the substrate and the circuit board may be performed so as to detect the first alignment mark and the second alignment mark so that the centers of the first alignment mark and the second alignment mark coincide with each other (S40).

Here, the first alignment mark can be detected by the first optical device, and the second alignment mark can be detected by the second optical device.

For this purpose, the first optical device and the second optical device can irradiate UV light or LED light.

The position of the first alignment mark and the second alignment mark is detected through the first optical device and the second optical device while the pattern shape of the first alignment mark and the second alignment mark irradiated with UV light or LED light is visible .

Thereafter, a step S50 may be performed in which the signal lines and the wiring of the circuit board are electrically connected so that the centers of the first alignment marks and the second alignment marks are aligned with each other.

Here, the signal wiring of the substrate and the wiring of the circuit board can be electrically connected by an anisotropic conductive film that can be disposed between the board and the circuit board by a method such as thermal compression.

Further, the signal wiring can be more than the number of the electrode pads.

7 is a block diagram of a touch sensing apparatus according to an embodiment of the present invention.

Referring to FIG. 7, a driving apparatus for driving the touch panel may be directly mounted on a part of the substrate 100 or may be formed on the circuit board 200.

The driving device may include a driving unit 210, a detecting unit 220, a signal processing unit 230, a memory 240, and the like, and may be implemented by one or more integrated circuit (IC) chips.

The driving unit 210 is connected to the signal line 120 and receives signals from the signal processing unit 230 to drive circuits for touch detection and outputs a voltage corresponding to a result of the touch detection determination. The driving unit 210 may include a plurality of switching elements connected to the electrode pad 110 and a capacitor.

The detection unit 220 is connected to the driving unit 210 and converts, amplifies or digitizes the voltage variation value of the electrode pad 110 received from the driving unit 210 and stores the voltage variation value in the memory 240. The detection unit 220 may include an amplifier and an analog-to-digital converter.

The signal processing unit 230 applies a signal for controlling the driving unit 210 or processes the digital voltage stored in the memory 240 to generate necessary information. The signal processing unit 230 may be implemented as an analog signal processing unit and a digital signal processing unit. Here, the analog signal processing unit controls the driving unit 210, and the digital signal processing unit can calculate the touch area and touch coordinates based on the voltage variation value detected from the detection unit 220. [ The signal processing unit 230 may include a microcontroller unit (MCU) and may perform predetermined signal processing through the firmware.

The memory 240 stores predetermined data used for touch detection, area calculation, touch calculation, or data received in real time according to a command of the signal processing unit 230. [

As described above, the driving unit 210, the detection unit 220, the signal processing unit 230, and the memory 240 may be separated, or two or more components may be integrated.

8 and 9, a detailed description will be given of a specific embodiment of the touch panel and the driving unit shown in FIG. 7 and the operation thereof.

FIG. 8 is an equivalent circuit diagram of a touch cell according to an embodiment of the present invention, and FIG. 9 is a waveform diagram of a touch cell according to an embodiment of the present invention.

8, the driving unit 210 includes a plurality of transistors Q and a plurality of first capacitors C1, and may further include a plurality of pad capacitors Cp. The transistor Q, the first capacitor C1, and the pad capacitor Cp may be grouped one by one for the electrode pad 110 and the signal wiring 120, and the electrode pad 110, the signal wiring 120, The transistor Q, the first capacitor C1, and the pad capacitor Cp are collectively called a "touch cell ".

The transistor Q may be a field effect transistor, for example, a control voltage Vc applied to its gate, a data voltage Vd applied to its source (or drain), and a drain (or source) 120, respectively. The control voltage Vc and the data voltage Vd may be applied under the control of the signal processing unit 230. [ Here, other elements capable of switching in place of the transistor Q may be used.

The first capacitor C1 may be formed between the gate and the drain of the transistor Q, and may be separately formed by a designer for securing a required capacity. The voltage signal applied to the first capacitor C1 may be the same as the voltage signal applied to the gate of the transistor Q, but a separate voltage signal may be applied. The voltage signal applied to the first capacitor C1 is preferably a square wave signal.

The pad capacitor Cp is a kind of parasitic capacitance formed by the electrode pad 110 or the signal wiring 120 or the like. The pad capacitor Cp may include any parasitic capacitance generated by the driver 210, the touch panel, and the image display device. In FIG. 8, reference symbol Ct denotes a capacitance formed between the electrode pad 110 and the user's finger when the user touches the electrode pad 110.

On the other hand, it is possible to arrange a cell having an electrical characteristic that is placed in a position that the user can not touch or is not always touched. The "reference cell" may be physically present, but may be a virtual cell having only data values.

9, the signal processing unit 230 may apply the data voltage Vd and the control voltage Vc to the source and gate of the transistor Q, respectively.

After the data voltage Vd rises, the transistor Q is turned on when the control voltage Vc applied to the gate rises from the low voltage VL to the high voltage VH. Accordingly, the output voltage Vo will be the data voltage Vd.

Next, when the control voltage Vc falls from the high voltage VH to the low voltage VL, the transistor Q is turned off, and the electrode pad 110 is in a floating state. At this time, the voltage level of the output voltage Vo of the electrode pad 110 is instantaneously dropped due to the level drop of the square wave applied to the first capacitor C1. This voltage drop phenomenon is also called "kick-back".

In the case where there is no touch on the touch cell or the reference cell (Case 1), that is, when the capacitors connected to the electrode pad 110 are only the first capacitor C1 and the pad capacitor Cp, these capacitors C1, The voltage drop (V1) of the output voltage (Vo)

. For the sake of convenience, the same reference numerals are used for the capacitors and their capacitances.

Equation (1) is easily derived from the equations for obtaining the total amount of charge before and after the voltage drop.

8, when the user touches the electrode pad 110 (Case 2), a capacitor Ct is formed between the electrode pad 110 and the finger or contact means of the user, The capacitors connected to the pad 110 are added with the touch capacitors Ct in addition to the first capacitors C1 and the pad capacitors Cp. The voltage drop V2 of the electrode pad 110 by these three capacitors C1, Cp, and Ct becomes equal to the following formula (2).

As a result, the voltage drop (V2) in the case of the touch (Case 2) becomes smaller than the voltage drop (V1) of the case without the touch (Case 1). The difference between the voltage drop (V2) and the voltage drop (V1) depends on the touch capacitance (Ct).

In general, the capacitance C of the capacitor is proportional to the area A of the electrode and is proportional to the distance d between the electrodes, that is, C = εA / d (ε is the dielectric constant). Accordingly, the larger the touch area, the larger the touch capacitance Ct. Using this relationship, the touch area can be calculated using the difference in voltage drop between the electrode pads 110 before and after the touch. Details of the calculation of the touch area will be described later.

As shown in Fig. 9, when the control voltage Vc applied to the first capacitor C1 fluctuates when the transistor Q is turned off, a voltage variation of the output voltage Vo occurs. In the embodiment of the present invention, the touch can be detected from the difference of the variation value of the output voltage Vo before and after the touch (that is, the difference between the voltage drop V2 and the voltage drop V1).

On the other hand, when the voltage applied to the first capacitor C1 rises from the low voltage (VL) to the high voltage (VH) when the transistor Q is turned off and becomes a floating state, although not shown, A phenomenon occurs. In this case, the total capacitance of Case 2 (Case 2) is larger than the total capacitance of Case 1 (Case 1), so that the voltage rise will be small (see Equations 1 and 2).

Next, a specific example of the detection unit shown in FIG. 7 and its operation will be described in detail with reference to FIGS. 10 to 12. FIG.

10 is a schematic block diagram of a touch cell and a detection unit according to an embodiment of the present invention.

Referring to FIG. 10, the detector according to the present embodiment may include an amplifier 222 and an analog-to-digital converter (ADC) 224.

The two inputs of the amplifier 222 may be the output voltage Vo of the touch cell 250 and the output voltage Vr of the reference cell 260 and the amplifier 222 may be controlled by the difference between the two output voltages Vo and Vr And outputs the amplified signal. 10, Va denotes an output voltage of the amplifier 222, and VaD denotes a digitized output voltage of the amplifier 222. In FIG.

Here, the touch cell 250 includes the electrode pad 110, the signal wiring 120, the transistor Q, the first capacitor C1, and the pad capacitor Cp shown in FIG. 8, Refers to a conventional touch cell that further includes a touch capacitor Ct and the reference cell 260 refers to a touch cell that does not include a touch capacitor Ct because no user touch occurs as described above.

The voltage difference (? V = Vo - Vr) between the output voltage Vo of the touch cell 250 and the output voltage Vr of the reference cell 260 is such that the control voltage Vc changes from the high voltage VH to the low voltage VL The voltage difference when it falls.

The voltage difference? V between the touch cell Vo and the reference cell Vr at the time when the control voltage Vc falls from the high voltage VH to the low voltage VL is expressed by the following equation (3).

11 is a graph showing the output of the amplifier in one embodiment of the present invention.

When the amplifier 222 is a differential amplifier, the differential voltage? V is amplified linearly, and saturated at a specific value or more and output a constant value.

11, the output voltage Va of the amplifier 222 is Vas when the difference voltage? V is equal to or higher than the saturation voltage? Vs, and has a magnitude proportional to the difference voltage? have. For example, if the difference voltage V is 0, the output voltage Va is 0 and the difference voltage V is? V1, the output voltage Va is Va1 and the difference voltage? V is? Va2 and the difference voltage? V is? V3, the output voltage Va can be Va3.

Meanwhile, when the electrode pad 110 according to an embodiment of the present invention is sufficiently small and the electrode pad 110 is completely covered by a finger when a touch is generated, the difference voltage? V has a maximum value, Or more.

Therefore, by designing the amplifier 222 such that the saturation voltage? Vs is less than or equal to the maximum value of the difference voltage? V, linearity can be imparted to the amplifier. The linearity can be used to calculate an accurate touch area.

The output voltage Va of the amplifier 222 is input to the ADC 224 and the ADC 224 can output the converted analog voltage Va to the digital signal VaD.

For example, the ADC 224 may divide the output voltage Va of the amplifier 222 into four sections and apply a digital value of 2 bits in the order of magnitude to each section. Referring to FIG. 13, when the output voltage Va of the amplifier 222 is about 0 to Va1, it is 00, Va1 to Va2 is 01, Va2 to Va3 is 10, and Va3 is 11 Can be given.

However, the digital value of 2 bits is only an example, and other examples such as 4 bits, 8 bits, and 10 bits are possible

12 is a graph showing the relationship between the difference voltage and the touch capacitance in an embodiment of the present invention.

Equation (3) is summarized again as a function of the difference voltage (V) as the touch capacitance (Ct).

(Where K1 = C1 (VH-VL), K2 = C1 + Cp,

Thus, K1 and K2 are constants, and are greater than zero)

As shown in FIG. 12, the touch capacitance Ct is 0 when the difference voltage V is 0. When the difference voltage V is increased, the touch capacitance Ct increases.

Here, since the touch capacitance Ct is proportional to the touch area A and inversely proportional to the distance d between the touch means and the electrode pad 110, that is, Ct =? A / d (? Is a dielectric constant) d) is constant, the touch area and the touch capacitance (Ct) are linearly proportional.

As a result, it can be understood that the larger the difference voltage? V, the larger the touch area A is.

As described above, when the entire area of the electrode pad 110 is completely covered by the touch of a finger or the like, the difference voltage? V becomes the maximum value and the touch area A becomes the maximum value. This is because the touch area A can not be larger than the area of the electrode pad 110.

12 is effective in the interval between 0 and the maximum value DELTA V_max and the linearity of the differential voltage DELTA V and the touch area A can be given by using this characteristic have.

For example, a linear function may be generated in the valid period and an output value of the generated linear function may be matched to each of the difference voltages? V.

Alternatively, linearity can be given between the differential voltage? V and the touch area A by applying a predetermined weight to the output of each differential voltage? V and correcting it.

Or linearity can be imparted by using the inverse function of the differential voltage? V and the touch area A, such as gamma correction.

Such correction for linearity can be reduced after the analog-to-digital conversion or simultaneously with the conversion.

Alternatively, when the relationship between the differential voltage and the touch area A of the voltage difference? Is not perfectly linear, the inclination is sufficiently gentle to provide sufficient accuracy for area calculation, and is treated as being substantially linear proportional, The differential voltage DELTA V can be used for calculating the touch area A.

As described in the embodiment related to Fig. 11, since the difference voltage V and the amplification value Va also have a linearity by the amplifier 222, the amplification value Va of the difference voltage V is also equal to the touch area A ) And linearity. Naturally, the digitized value VaD of the amplification value Va also has a linearity with the touch area A.

The relationship between the differential voltage (? V) and its amplification value (Va or VaD) defined by the various embodiments described above and the touch area (A) is referred to as "substantially linear proportional ". Using this "substantially linear proportional" relationship, the touch sensing device according to an embodiment of the present invention can detect a very accurate touch area and coordinates.

13 is a schematic diagram for explaining a correspondence relationship between a touch cell and a memory in a touch sensing apparatus according to an embodiment of the present invention.

The memory 240 shown in FIG. 7 includes a plurality of memories 240 having addresses corresponding to, for example, the touch cells 250 (strictly speaking, used as the electrode pads 110 but used as the touch cells 250 for descriptive convenience) And each memory cell may store a difference voltage VaD that is amplified and digitized through the amplifier 222 and the ADC 224.

As described above, the amplified and digitized difference voltage VaD is substantially linearly proportional to the touch area with respect to the electrode pad 110. Therefore, the amplified and digitized difference voltage VaD is treated to be equal to the touched digital area value.

In the present specification, the amplified and digitized difference voltage (VaD) is referred to as "voltage variation value (VaD)" for convenience.

13, the touch cells C1 to C16 and the memory cells M1 to M16 are shown, and M1 to M16 correspond to C1 to C16, respectively. Touches are generated in the touch cells C6, C7, C10, C11, C14 and C15, C6 is about 2/5 of the total area, C7 is about 3/5, C10 and C11 are all, C14 and C15 are about 1 Let's say that less than 10 touches your finger.

00 is stored in the memory cells C1 to C5, C8, C9, and C12 to C16 corresponding to the touch cells C1 to C5, C8, C9, and C12 to C16 11, 10 for M10 and 11 for M11.

The signal processing unit 230 reads the digital area values of the touch cells C1 to C16 from the memory 240 to determine the contact area and the contact position. This will be described in detail with reference to FIGS. 14 to 18. FIG.

FIG. 14 is a flowchart illustrating a method of calculating a touch area and touch coordinates according to an embodiment of the present invention.

Referring to FIG. 14, the touch sensing apparatus according to the present embodiment first measures a voltage variation value (VaD) of each touch cell (S110). In order to measure the voltage variation value VaD, each of the electrode pads 110 is scanned in order with a predetermined frequency. It is determined that a touch is generated in the touch cell whose voltage variation value VaD is not 0 and the voltage variation value VaD is recorded in the memory 240 in correspondence with each touch cell.

Next, a touch cell group composed of adjacent touch cells whose voltage variation value VaD is not 0 is extracted (S120). According to an embodiment of the present invention, since the electrode pads 110 are each implemented in an isolated matrix form, the multi-touch sensing function is provided. Accordingly, when multi-touch occurs, a step of grouping the touch cells in which the touch occurs is required to calculate the respective touch areas and coordinates.

Next, the area of the touch area is calculated based on the voltage variation value (VaD) of the touch cell group (S130). As described above, since the voltage variation value VaD and the touch area are mutually proportional, the touch area can be calculated by summing the voltage variation values VaD in the touch cell group.

Next, coordinates of the touch area are calculated from the area of the calculated touch area (S140). In the touch panel according to an embodiment of the present invention, the electrode pads 110 are formed in a polygonal shape having a uniform size, and are arranged in a matrix shape. Thus, the image display device is covered with the predetermined area and address of each of the electrode pads 110. Accordingly, the occupied area of the electrode pad 110 can be matched with the coordinates of the image display device.

When the information on the touch occupation area is calculated for each electrode pad from the touch area calculated in step S130, the touch area distribution of the X axis and the Y axis of the electrode pad matrix can be obtained. If the area center points of the X and Y axes are found based on the area distribution, the touch coordinates can be calculated.

The touch coordinates can be calculated very accurately using the structure of the touch panel and the calculated touch area.

14 can be performed in a signal processing unit disposed inside or outside the touch sensing apparatus.

FIGS. 15 to 18 are views for explaining a process of calculating the contact area and the contact position according to an embodiment of the present invention.

When the contact position shown in Fig. 13 is expressed as an area, it becomes a hatched area in Fig. At this time, for example, a group consisting of four adjacent touch cells having a digital area value other than 00, for example, 2 × 2 cells, and the sum of the digital area values of the touch cells belonging to this group, ie, 01, 10, 11, It can be regarded as a touch area.

The area value can be calculated because the voltage variation value VaD and the touch area are substantially linearly proportional to each other.

Although a 2x2 cell group has been described as an example, a group consisting of more or fewer cells may be selected depending on the size of the electrode pad and the size of the touch area. In the case of displaying the digitized voltage variation value (VaD) of the touch cell by 2 bits, a total of 4 area values can be obtained for one cell and 16 area values can be obtained in the 2x2 cell group.

If the digitized motorized voltage value is digitized to a higher bit, the calculated area value can be more accurate, and the size of the adjacent touch cell group having a non-zero digital area value can be larger.

16 is a diagram illustrating a method of calculating touch coordinates according to an embodiment of the present invention.

Referring to FIG. 16, the center position of the touch region shown in FIG. 15 may be a point indicated by X. FIG. The digital area values of the upper left, upper right, lower left, and lower right touch cells for the 2x2 touch cell group, that is, 01101111 successively described as 01, 10, 11, and 11 are defined as values indicating the contact positions, The coordinates of the center position X can be stored in the internal or external memory in the form of a look-up table.

Alternatively, when the touch cell group in which the touch occurs is determined, the touch coordinates may be calculated in real time based on the mutual correspondence relationship between the coordinates of the touch cell and the digital area value of the touch cell.

17 is a diagram illustrating a method of calculating touch coordinates according to another embodiment of the present invention.

Referring to FIG. 17, the digital area values of the touch cells are summed with respect to each of the row X-axis and each column Y-axis of the touch cell group in the form of a 2x2 matrix, and is shown in a graph. For example, a graph is shown on the lower side and on the right side respectively in Fig.

In the lower graph, the sum of the digital area values corresponding to the first column is 01 + 11 and the sum of the digital area values corresponding to the second column is 10 + 11. In this graph, an X coordinate is obtained by bisecting the value integrated on the X axis (that is, the area of the area between the horizontal axes).

For example, if the width of the touch cell is 1 and the left boundary of the block is 0, a straight line parallel to the horizontal axis will be drawn with a height of 4 (= 01 + 11) in decimal notation in the range of 0 to 1, In the range of 1 ~ 2, the height will be 5 (= 10 + 11) in decimal and a straight line parallel to the horizontal axis will be drawn. The area between the horizontal axis and these straight lines will be a stepped shape as shown in Fig. 16, and the area of this figure is 9 (= 4 + 5). (4 + 5x) = 5 (1-x) when the abscissa of the vertical line bisecting the area of the figure is set to (1 + x). Therefore, the horizontal coordinate of the vertical line becomes 1.1.

Similarly, in the right graph, the digital area value for the first row is 01 + 10, which is the sum of the digital area values for the second row, 11 + 11. In this case as well, a Y coordinate that bisects the value integrated in the Y axis (i.e., the area of the area between the vertical axes) is found.

For example, if the height of the touch cell is 1, the upper boundary of the block is 0, and the coordinate value becomes larger toward the lower side, the height is 3 (= 01 + 10) A parallel straight line will be drawn. In the range of 1 to 2 on the vertical axis, the height will be 6 (= 11 + 11) in decimal and a straight line parallel to the longitudinal axis will be drawn. The area between the vertical axis and these straight lines will be a stepped shape as shown in Fig. 17, and the area of this figure is 9 (= 3 + 6). (3 + 6x) = 6 (1-x) when the ordinate of the horizontal line bisecting the area of the figure is set to (1 + x). Therefore, the ordinate of the horizontal line is 1.25.

In this manner, touch coordinates can be calculated by obtaining the x-coordinate and the y-coordinate which are the centers of the touch area.

Since the electrode pads are arranged on the image display device in the form of a matrix, the coordinates in the electrode pad matrix can be matched with the coordinates of the image display device. Therefore, by using the coordinates of the center position of the area distribution of the X axis and the Y axis in the touch cell group in which the touch occurs, the center position of the entire touch area can be calculated in the image display apparatus.

The signal processing unit 230 can determine the touch position using the touch area occupying each cell in this manner. Even if the value of the touch cell is represented by 2 bits, since a total of 256 positions can be obtained for one block, a touch coordinate resolution higher than the number of touch cells can be obtained.

If the digitized area value is provided with a higher bit, the resolution of the touch coordinates will be much higher. That is, if the digitized area value is provided with a higher bit, the change of the fine touch area distribution can be detected, and the change of the fine touch coordinates can be detected using the digitized area value.

FIG. 17 illustrates a fairly simple example, and additional statistical processing may be further performed to produce a more accurate area distribution within the touch cell group.

18 is a diagram showing touch coordinates and a touch area together according to an embodiment of the present invention.

Referring to FIG. 18, when a touch occurs in a predetermined area, an accurate contact area is calculated by adding digital area values of touch cells belonging to a touch cell group, which is a set of touch cells having a digital area value other than 00, The distribution of area values can be appropriately processed to find the exact center of contact.

In addition, by using the coordinate information of the touch cell in which the touch occurs, the shape information of the area where the touch is generated can be provided. For example, in FIG. 18, since a touch occurs in the 2x2 touch cell group, a circular touch area having the detected area can be calculated. However, if a touch occurs in the 2x3 touch cell group, a long oval touch region having a vertical axis can be calculated. Therefore, according to the embodiment of the present invention, the shape of the touch region may be used as one of the user inputs.

In addition, if the touch area value in the touch cell of the touch cell group is taken into consideration, a more precise shape of the touch area can be calculated.

The obtained touch area and the touch position can be used as an input gesture for driving an electronic device including a display device related to the touch sensing device, for example, a smart phone or the like.

It will be understood by those skilled in the art that the foregoing description of the present invention is for illustrative purposes only and that those of ordinary skill in the art can readily understand that various changes and modifications may be made without departing from the spirit or essential characteristics of the present invention. will be. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive. For example, each component described as a single entity may be distributed and implemented, and components described as being distributed may also be implemented in a combined form.

The scope of the present invention is defined by the appended claims, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included within the scope of the present invention.

100: substrate 110: electrode pad
120: signal wiring 200: circuit board
210: drive 220:
222: amplifier 224: analog-to-digital converter
230: signal processor 240: memory
250: touch cell 260: reference cell
290: Wiring 300: Anisotropic conductive film
310: first alignment mark 320: second alignment mark
400: first optical device 410: second optical device
420: Position adjusting device 430: Control device

Claims (11)

Forming a first alignment mark on a substrate of a touch panel including an electrode pad and a signal line formed of a transparent material in a single layer;
Forming a second alignment mark on the circuit board corresponding to the first alignment mark;
Detecting the first alignment mark and the second alignment mark and adjusting a position of at least one of the substrate and the circuit board so that the center of the first alignment mark and the center of the second alignment mark coincide with each other; And
And aligning the first alignment mark and the second alignment mark so that the signal wiring and the wiring of the circuit board are electrically connected to each other. The method according to claim 1,
Wherein the electrode pad, the signal wiring, and the first alignment mark are made of the same material. 3. The method of claim 2,
Wherein the same material is indium-tin oxide (ITO). 3. The method of claim 2,
Wherein the first alignment mark and the second alignment mark are detected by UV light or LED light to be illuminated. The method according to claim 1,
And the second alignment mark is made of the same material as the wiring of the circuit board. The method according to claim 1,
Further comprising the step of placing an anisotropic conductive film between the substrate and the circuit board after the step of forming the second alignment mark. The method according to claim 1,
Wherein a plurality of the electrode pads are provided, each of the electrode pads is arranged in an isolated matrix shape, and the signal wiring is more than the number of the electrode pads. A touch panel having a substrate on which an electrode pad and a signal line of a transparent material are disposed in a single layer and on which a first alignment mark is formed; And
And a circuit board on which a second alignment mark corresponding to the first alignment mark is formed,
Wherein at least one of the substrate and the circuit board is positioned such that the first alignment mark and the second alignment mark are detected and the centers of the first alignment mark and the second alignment mark coincide with each other, Wherein the wiring of the circuit board is electrically connected. 9. The method of claim 8,
Wherein the electrode pad, the signal wiring, and the first alignment mark are made of the same material. 9. The method of claim 8,
Wherein the first alignment mark and the second alignment mark are detected by UV light or LED light to be illuminated. 9. The method of claim 8,
Wherein the plurality of electrode pads are arranged in an isolated matrix, and the signal wiring is equal to or greater than the number of the electrode pads.

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