KR20060007799A - Method of manufacturing circuit layout on touch panel by utilizing metal plating technology - Google Patents

Abstract

The present invention provides a method for manufacturing a circuit layout on a touch panel using a metal plating technique, in which a predetermined area is adjacent to an edge of a transparent conductive layer on a transparent glass substrate to form a circuit using a metal plating technique. Consistently coating the conductive metal or conductive metal oxide. This configuration has the advantages of uniform thickness of the thin film circuit, good adhesion of the plating material to the bottom substrate, improved climatic and chemical properties and weldability, whether thin or bare glass.

touch screen

Description

METHOD OF MANUFACTURING CIRCUIT LAYOUT ON TOUCH PANEL BY UTILIZING METAL PLATING TECHNOLOGY}

1 is an enlarged view of a conventional 4-wire touch screen.

2 is an enlarged view of a 5-wire touchscreen.

3 is an enlarged view of an 8-wire touchscreen.

4 is an enlarged view of a three-wire touchscreen.

5 is an enlarged view of a seven-wire touchscreen.

6 is a flow chart of a preferred embodiment of the present invention.

7 is a schematic representation of spray rinse performed on resistive glass in accordance with a preferred embodiment of the present invention.

8 is a cross-sectional view showing a resistive ink coated on a resistive glass according to a preferred embodiment of the present invention.

9 is a schematic view of etching performed on resistive glass in accordance with a preferred embodiment of the present invention.

Fig. 10 is a sectional view showing the ink removal performed on the resistive glass according to the preferred embodiment of the present invention.                 

11 is a cross-sectional view showing a mask formed on the resistive glass according to the preferred embodiment of the present invention.

12 is a schematic diagram showing sputtering performed on a resistive glass according to a preferred embodiment of the present invention.

13 is a perspective view of a formed resistance glass according to a preferred embodiment of the present invention.

14 is a perspective view of a formed resistance glass according to another preferred embodiment of the present invention.

The present invention relates to a method of manufacturing a circuit layout on a touch panel, and more particularly, to a method of manufacturing a circuit layout on a touch panel using a metal plating technique.

references

United States Patent

3.632,874 Malavard

3,798,370 Hurst

3,911,215 Hurst and Colwell, Jr.

4,198,539 Pepper, Jr.

4,220,815 Gibson and Talmage, Jr.                         

4,371,746 Pepper, Jr.

4,661,655 Gibson and Talmage, Jr.

4,777,328 Talmage, Jr.

5,815,141 Phares

6,549,193, B1 Huang

6,650,319 Hurst, et al.

Touch-based input devices (such as touch panels or touch screens) are used in many electronic products (eg, Global Positioning System (GPS) devices, personal digital assistants (PDAs), cell phones, and personal digital assistants). It has been widely used as a replacement for computer input devices (eg keyboard and mouse) well known in the art, and as computer input devices for sophisticated applications such as factory process automation device control and POS applications in retail. . The convenience of many POI kiosks has been improved by using touch screens. These large design improvements have improved the convenience of operating electronics and have led to the replacement of hardware control devices (eg switches and potentiometers), particularly in precision products. This may further cause additional space required for the design of large displays. And it can also serve as a design method which saves the total cost of such an apparatus. Finally, the user can easily control the device and can easily execute the software program or browser information. An important application of touchscreens is that they are used with video displays controlled by computers or devices controlled by some form of microprocessor. Since most computer display devices with a aspect ratio from square to 16: 1 or more are rectangular, most touch screens also consist of rectangular devices. In addition, many displays are flat so that the touch screen that matches the shape of these flat displays is also flat. However, all of other aspect ratios, other shapes of non-rectangular touch screens, and non-planar touch screens for use in spherical or cylindrical CRT displays are known (eg, in US Patent Nos. 2, 220 to Gibson and Talmage). 815 and Pepper, Jr. 4,371,746 and Talmage 54,777,328).

The touch system typically includes a touch screen, which is a physical part of the system where a user looks at the associated display and touches it with a finger or stylus, and a controller that applies a control or drive signal to the touch screen to process information received from the touch screen. do. The intention of the touch screen and its controller is reported to the host computer that a particular location on the touchspring has been touched by the user. Although not clearly described in the specification of most devices or systems, the touchscreen controller always reports the touched position in Cartesian or rectangular coordinates. These coordinates may or may not represent the spatial coordinates of the display in a format directly available to a computer or other controller, but each coordinate report from each touchscreen controller is the only point on the Cartesian plane of the touchscreen. Depicts. The interpreter, driver, or software typically processes touch data received from the touch screen controller and normalizes it to the coordinate space of the display or converts the touch data into a form that is compatible with data from other input devices, such as a mouse. .

Regardless of the device that the touch system emulates, it is important to recognize that the touch system is an absolute positioning device and derives all functionality from accurate and rapid reporting of the precise position touched. In response to the touch, the computer performs some action based on the precise touch position touched or creates a presentation on the display corresponding to the position of the touch, which may be an icon, text character, or spot of color or other unique identifier. This representation can be as small as the smallest resolution position on the display and is generally known as a pixel in the display industry. Depending on the touchscreen and the intended mode of operation of the device, it is apparent that the user can write on the touchscreen by generating a continuous display of pixels in response to the user dragging a finger or other stylus across the touchscreen. .

Techniques commonly used in touchscreens are known to those skilled in the art as infrared, surface wave, capacitive and resistive touchscreens.

Resistive touch screens are the most widely used. The resistive touch screen category includes several types of devices. One form is known as a digital or switch matrix resistive touch screen. The touch screen is mounted on a flat sheet of transparent glass or plastic or a combination thereof. The active area of the touchscreen (limited anywhere) is a uniform dimension of one dimension and comprises a plurality of conducting circuits arranged regularly across one of the two active layers of the planar sheet in the visible or active area of the touchscreen. It is included. Part M of this circuit is pasted and placed across the first layer and the rest of the circuit, and N is similar but arranged to be orthogonal across the second layer. The surfaces of the first and second layers comprising the circuitry are close to each other and maintain a minimum distance between the first sheet and the second sheet to prevent contact between the circuits when the user does not touch the touch screen. Separated by regularly spaced insulating Iceland (generally less than 0.010 in diameter). This minimum distance is set by the thickness of the insulating ice and is generally 0.001 or less. Each circuit is connected to an electronic controller that detects contact between one or more circuits of the first layer and one or more circuits of the second layer caused by a force applied to an external sheet of the touch screen. The outer sheet (eg, the surface of the sheet of the touch screen in close proximity to the user), which must bend sufficiently to deflect with a small force, is pressed by a finger or other stylus. Typical active forces due to fingers are more than 1-12 ounces on practical touchscreens. In the case of the M circuit on the first layer and the N circuit on the second layer, the total number of touch positions that can be resolved by the platen device is M × N. The circuitry in the device described above is an active or visible area, especially when the device is located over an information display (eg, a display whose content can change over time or change in response to an operator's input). A thin layer of substantially transparent conductive material such as (e.g., indium-tin oxide (ITO), tin-anti-money oxide (TAO), nickel, gold or a suitable mixture thereof or other material suitable for the intended application) It is usually composed. However, the circuit need not consist of substantially transparent material and is not an application of the limited contemplated device used with the information display described. Substantially transparent devices of the digital, or switch-metrics type, or analog resistance type, considered afterwards, may be outlined in a picture, menu, chart, diagram, district color, or in the outline of a touch-sensitive location or (information panel Can be considered as a visual button or switch that expresses a function) and is used in conjunction with a fixed information panel that includes a legend of touchable positions on the touchscreen that can be placed in front and on both of the touchscreen devices. . Moreover, even if information guiding the user to the available touch locations is painted, screen printed, applied or pasted directly to one of the two outer surfaces of the touch screen, there is no need to construct a separation panel. When the touchscreen is normally viewed, i.e., when the user viewing position is near an imaginary line protruding perpendicularly from the plane of the two active layers, the information is arranged to match the touch sensing position as appropriate. There is no more need for the user to view information to successfully interact with the touchscreen. The appropriate legend described above to guide the user to the touch sensitive location can be supplemented or replaced with a Braille legend or other touch area properly positioned across the outer surface of the touch screen to see that it is damaged. Voice prompts and gestures guide the user to an appropriate touch sensitive location on the screen to protect the user from visible damage. Thus, the term touchscreen used in the present invention describes a broad class of devices that are not limited to the description of the device in the preferred embodiment.

Another class of home touchscreens that are distinguished from digital or switch-matrix touchscreens is known as analog resistive touchscreens. This analog touchscreen is commonly referred to by a person skilled in the art as a resistive turkey screen. Analog touchscreens typically consist of a plastic sheet or flat glass as described for digital or switch-matrix touchscreens, but using a peripheral circuit connected to a continuous transparent conductive thin film in the active region, this one continuous conductive thin film Is for each active layer. Regardless of the specific name given, it can be seen in the following description that there are many changes in this class of device called resistive touchscreens and that the claimed feature is not important in the context of the present invention based on the number of external active circuits used. will be.

Analog resistive touch screens have existed for over 25 years. At that time, many methods of exciting and controlling touch screens have been developed, and the names of these touch screens based on the number of externally connected active circuits have been commonly used by those skilled in the art. We will describe such alterations and those alterations and other alterations not shown and described for the purposes of the present invention are within the scope of the present invention.

The simplest analog resistive touch screen is a four-wire type. This prior art is shown in FIG. The touchscreen is a plastic coated with a substantially transparent (more than 80-90% light-transmitting) conductive film of a constant resistance (not worse than +/- 10%) deposited on the inside or opposite side of the first and second sheets. And / or two sheets of glass 10, 20. This thin film is commonly referred to as a resistive thin film to distinguish it from a conductive thin film that does not have a constant resistance requirement and the importance of this distinction will become apparent when considering other resistive touchskirin variations.                         

At opposite ends of each sheet proximate the edge of the sheet, conductive bus bars or strip electrodes 21, 22 are deposited on top of the resistive thin film so as to be essentially electrically connected with the resistive thin film. The method of deposition will be considered later in this application, but there may be many methods. As long as each busbar deposited on the first sheet is orthogonal to a set of busbars deposited on the second sheet, the specific arrangement of the busbars is not critical to the liver of the touchscreen. The position and size of the busbars on the first and second sheets define a limitation of the active area of the active area of the touch screen (eg, the area where touch is performed), as shown in FIG. 1. The two bus bars are controlled by the precise size and position of the bus bar and the resistive film to which it is attached, and by the placement of an insulating layer to further limit the boundaries of possible contact between the resistive films in the plane of the first and second sheets. Although slightly different, this active area is often called a viewable area. Appropriate connections 31, 32, 33, 34, called drive traces or drive lines, to the external electronic controller are made for each busbar. Although shown to clarify a drive line connected in the center, a drive line substantially connected at the end may also be used. It is an object of the present invention to provide technical requirements for this connection and the present invention provides an improvement due to this property. The function of the four wire touchscreen follows the resonant principle of an electronic voltage divider or potentiometer. In a first operation, a controller, usually a device controlled by a microcontroller, typically applies a DC of less than 5 volts between both ends of the resistance sheet by applying an appropriate potential difference to a pair of bus bars on the selected resistance sheet. The composite current value sets the potential gradient on the sheet between the two buses for this sheet. Once the system of FIG. 1 is considered and potential is applied to the first sheet 10, the second sheet is used as the voltage probe for the first sheet. The finger or stylus force exerted by the user 50 causes the second sheet to make mechanical and electrical contact with the first sheet. The voltage on the first sheet is connected to the second sheet. The logic on the second sheet is connected to a high impedance input on the controller that can buffer or filter this voltage by logic appropriate to the logic from the switching of the controller microprocessor and the electronic circuit attached to the second sheet, but ultimately An analog-to-digital conversion is performed on the voltage to prepare for storage and further processing. The voltage on the first sheet connected to the controller after the second sheet is proportional to the position on the first sheet relative to the position of the busbar contacted by the second sheet in response to the user's touch, whether analog or digital. Therefore, the position of the touch is determined only in one axis or in one direction. A second operation is required to uniquely determine the substantial planar position of the user's touch in both directions or axes. The second operation is similar to the first operation described. In the second operation, the touch having occurred in the above-described operation of determining the position of the touch on the first sheet will be used to determine the position of the touch on the second sheet. In the second operation, a similar potential is applied to the second sheet as it is applied to the first sheet in the first operation. The first sheet is constituted by a controller for use as a voltage probe, and the potential gradient formed in the second sheet is further connected to the first controller to perform the same processing as performed in the first operation. The second signal indicates the position of the touch on the second sheet. Description of the actual processing of requesting, processing and reporting the location of the touch relative to the host computer or other device is known to those skilled in the art.

Another form of a conventional analog resistive touch screen is the form of a five wire. The configuration of this five wire touch screen is shown in FIG. In this five-wire form there is only a first resistive sheet. This sheet is generally a sheet away from the bottom or bottom sheet or user. Generally, the first resistance sheet is made of glass. The conductive thin film is on the inner surface of the second sheet facing the first sheet. The conductive thin film on the second sheet does not have a resistance requirement as described in the first sheet, and furthermore, while the nominal resistance is specified in a certain range, there is no +/- 10% uniform condition. The thin film on this sheet of the five wire touchscreen has a conductive coating that is distinct from the resistive coating. In a five-wire touchscreen, all electrical information that determines the location of the user's touch is formed on the first resistive sheet. Electrically, the second sheet is used only as a voltage probe and in some configurations only as a current source or sink. Five-wire touchscreen systems also form an appropriate voltage gradient, current distribution, or other electrical analog, which is different from the design principle for busbars on 4-wire touchscreens, but is similar in function to the active area (11-18). It requires a peripheral electrical circuit disposed along the outer edge. Briefly, an appropriate potential is applied by the controller to the nodes of the four peripheral circuits to create a uniform potential gradient on the first resistive sheet that is directed across one major mechanical axis of the touch screen. Conductive sheet 20 picks up the potential from the first sheet, similar to that described for the 4-wire touch screen, when touch is issued. To obtain the vertical touch position, the controller then forms a second potential gradient on the resistance sheet that is orthogonal to the first potential gradient by changing the applied potential. The conducting sheet again picks up the potential from the first sheet at the touch point. The rest of the operation is similar to that described for the 4-wire touchscreen. Designing for 5-wire peripheral circuits may be necessary only for touch screens or may require a specific design for the controller. There are many designs of these five wire touchscreens and controllers. However, those skilled in the art will appreciate that many five wire and derivative touch screens and their respective controllers are interchangeable in basic functionality. One object of the present invention is that many of these five wire and derivative touchscreens are identical to the considerations of the present invention. 2 shows one of the common designs of Gibson and Talmage (Gibson, W.A., and Talmage, Jr., J.E, US Patent 4,66,665). In this prior art, the peripheral electrical circuit is designed for use with a controller that forms the above-mentioned sequential quadrature voltage gradient in the first resistive sheet in response to a user touch. Thus, the specific planar position of the touch is determined by this system. Other designs for five-wire touchscreens are disclosed in many US patents, particularly designs for issuing very constant potential gradients and minimizing the area of peripheral circuits orthogonal to the edge of the resistive sheet where the circuit is placed. This application is included for reference only. Cite Malavard (3,632,874); Hurst (3,798,370); Hurst and Colwell. Jr (3.911, 215); And Pepper, Jr. (4,198,539).                         

Releases for four wire and five wire touchscreens are often referred to as a number of external electrical termination precentres. These include but are not limited to the following types of touch screens. That is, they include (1) an "8 wire" depicting a four wire touch screen with four remote sensing circuits. These circuits provide a feedback signal to the controller and can be used as a means of automatic calibration of the touch screen to compensate for the voltage drop in the circuit between the controller and the point where the circuit is connected to the bus shown in FIG. 1, which calibration can be used as a touch screen. Normal of the controller coordinate system and computer video coordinate system. The function of this 8-wire touch screen is the same as that of a 4-wire touch screen in all other respects. An eight-wire touchscreen is shown in FIG. 3. (2) FIG. 4 shows a “3-wire” or “diode” for a five-wire touch screen different from using an electronic diode to switch the potential applied from the controller between two orthogonal directions on the first resistive sheet. Two external electrical terminals on the 5-wire Turkish screen have been removed, leaving only three external terminals. By appropriate configuration of the external electrical terminal the 3-wire touchscreen is directly controlled by the 5-wire touchscreen controller without modification. (3) “6-wire” depicts a 5-wire touch screen having a sixth wire and connected to an electrostatic shield on the outer surface of the first resistive sheet. This electrostatic shield reduces noise from the common electronic display to the touchscreen. (In order to be effective, this shield must be made with a resistive bus bar that has a low resistance and this is very low. This connection will be improved by the application of the present invention instead of a conventional screen printed bus bar). (4) The "7-wire" touch screen is a 3-wire (diode) touch screen with four additional external circuits. The circuit is connected to one of the four edges of the first resistive sheet, as shown in FIG. 5, and provides a signal to the controller allowing automatic calibration of the system of the touch screen. Substantially the connection of the additional circuit to the touch screen is made at the diode contact with the resistive thin film to the active area of the touch screen with respect to one of the diodes or the connection to the external circuit is adjacent to the edge of the active area of the touch screen. Away from the diode contacts. The operation of this touchscreen is the same as that of the 3-wire touchscreen except for the function of automatic calibration. Although a description of this automatic calibration technique is given when considering a 7-wire touchscreen, it is equally applicable to the 5-wire or 6-wire touchscreen described. Moreover, the addition of additional calibration circuitry to the touch screen may change the famous description of the form of the touch screen, but it will be appreciated that this described modification remains within the scope of the present invention. U. S. Patent No. 5, 815, 141 discloses two sheet resistive touch screens with a segmented conductive thin film on a second sheet provided for identifying an object touching the top surface of the touch screen. It is a six-wire touchscreen that has two sections of the second sheet and is considered a five-wire analog resistive touchscreen for the purposes of the present invention. The novel 5-wire resistive touchscreen (US Pat. No. 6,650,319) by Hurst et al. Includes a simple peripheral circuit disposed at the edge or corner of the first resistive sheet. By appropriate manipulation of the peripheral circuit connected to the first sheet and the resistance of the first sheet and by the use of an appropriate mapping algorithm, the present invention can have a uniform orthogonal equivalent potential voltage points or a non-uniform distribution connected with a suitable mapping algorithm by a controller. A resistive or capacitive touchscreen is disclosed that can achieve the same result with. It is a further object of the present invention to make the resistance of the peripheral circuit required for this touch screen more predictable and constant, which results in a desirable resistance ratio between the resistive sheet associated with the electrode of the described peripheral circuit.

The capacitive touchscreen can be considered a five-wire touchscreen without a second conductive sheet. Pepper, Jr., (US Pat. No. 4,198,539) and the like describe this invention. The user's finger or stylus of appropriate conductivity is replaced with the second conductive sheet of the 5-wire touchscreen and functions to sink the current from the first resistive sheet. Since the resistive sheet is generally overcoated with a transparent insulating material for optical and mechanical reasons, a controller drive signal that can be applied as described previously for a 5-wire resistive touch screen or simultaneously applied to four drive circuits is weak. AC current signal at frequencies above 10KHz. As is known to those skilled in the art, capacitive touchscreens may utilize electrical circuits for linearization and application of the same voltage gradient or current distribution as circuits used for resistive touchscreens of equal size and an object of the present invention is to consider these capacitive touchscreens. You will see that it applies to.

One of the primary specifications of the touch screen is the precision or linearity of the touch screen. No matter what software (calibration program) is typically at the computer level that maps the coordinate space of the touchscreen to the coordinate space of the display, how the touchscreen or combination of touchscreens and their associated controllers match the Cartesian coordinate space. It is a description. The method of satisfying the mentioned linearity is important for understanding the design of the touch screen and the intention of the present invention.

Surface waves and infrared touchscreens operate only as delicate controllers designed for this purpose, with almost perfect linearity, because the position of the surface wave reflector and infrared optics pairs that determine the location of the touch are fixed. The scope of the present invention does not include these devices. However, the linearity of resistive voltage dividers, i.e. touchscreens operating on the principle of analog resistance and capacitiveness, must be designed and manufactured by paying attention to both of these materials and processes depending on the electrical and mechanical properties and processing of many materials do. Although this result is simple in principle, resistive and capacitive touchscreens are often difficult to manufacture and use one of two different methods to achieve the aforementioned linearity of the touch system. This first method serves for the touch screen controller to process and report touch position information that is generally proportional to the voltage received from the touch screen. Analog or digital filtering of multiple readings by a controller of the same touch position and whatever averages are issued, there is no nonlinear or non-orthogonal mapping of the touch voltage to accurately describe the Cartesian space. This means that the touch screen has equivalent voltage logic in response to an applied potential from the controller that is straight and parallel to the appropriate machine axis of the touch screen and orthogonal to the equivalent potential logic for the other axis of the touch screen. Although this design criterion implies that material and design are important and that extensive testing of the touch screens provided is necessary for the inspection of the linearity specifications described, these touch screens conform to inherent controllers or external memory circuits (see second method). It does not mean that it does not require linearity to achieve this aforementioned circuit musk. The touchscreen can be used without losing linearity with touchscreen controllers designed and manufactured by multiple third party controller vendors. This interoperability is an important feature of today's analog resistive touch market. The second method of achieving the above-described linearity of the touch system does not precisely depend on the perpendicular and orthogonal equipotential voltage logic for the first resistive sheet, but rather the Cartesian coordinates formed by the controller from the processed voltage are the result of the mapping algorithm. In general, this algorithm is linear interpolation and depends on a multipoint data array generated by many points of precise touch on the touchscreen, and the points to be touched are generated by software programs designed for the purpose. Because all touchscreens are unique, the routine must be run for all touchscreens before end users use them as part of the manufacturing process. This data array is stored in a nonvolatile random access memory (NVRAM) in either the controller circuit or an external circuit that can be read by the controller and used as a reference point by an interpolation algorithm. A 9 + 25 point routine is common.

In practice, this algorithm compensates for very small errors (less than 5%) of the linearity of active area subgroups of substantially discontinuous linearity between adjacent reference points and substantially linear touchscreens on non-linear displays that are discontinuously linear between adjacent reference points. It has many advantages to match. An example of a nonlinear display is generally a CRT with horizontal scanning characteristics where one or both vertical edges are nonlinear compared to the midpoint of the display. The result of this linearity is generally desirable when the touch screen is used for single tooth type applications. Damage in response speed is seen when used in touch applications where high-speed movements occur continuously. Another conclusion is that the third party controller may not be intended to perform the same type of linearity. While the touch screen and this third party controller work properly together for some applications, the linearity of the touch screen can be damaged near the edges, especially at the corners of the touch screen. This linearity problem is particularly noticeable when the graphical user interface (GUI) " desktop " is controlled by a touch screen rather than a touch control application. These GUI desktops have a small target in the corner of the display that must be touched to start or stop the application or its own computer. Another conclusion is that the NVRAM chip must be programmed in the pattern (which increases cost for the manufacturer or customer), increasing the chance of mistakes in performing linearity.

There are many factors in the design and materials of touch screens that adversely affect the resolution, precision and accuracy required from the touch screen itself. Moreover, the factors of material selection and touch screen design have a significant negative impact on service life and permanence. These resolution, precision, and accuracy factors include: (1) the uniformity of the resistance of the resistive thin film, (2) the same resistance of the external drive circuit to the 5-wire touchscreen, and (3) the corner of the drive trace throttling on the 5-wire touchscreen. Acceptable ratio of corner-to-corner resistance, (4) Acceptable ratio of sheet resistance to drive trace resistance in a 4-wire touchscreen, (6) Uniform resistance of 5-wire touchscreen peripheral circuit electrodes, and (7) Peripheral electrode The adhesion of and the contact resistance between a resistive or conductive thin film on a 5-wire and 4-wire touch screen. Persistence and service life are the generality of (1) contact resistance between contact resistance and the adhesion of a peripheral circuit electrode to a resistor or conductive thin film, and (2) contact between the peripheral circuit terminal and an external cable. One aspect of the present invention is to improve many of the aforementioned design and manufacturing characteristics.

In the touch panel of the prior art, regardless of whether a 3-wire, 4-wire, 5-wire, 6-wire, 7-wire, or 8-wire peripheral circuit is carried out in the wiring, the circuit is a transparent conductive layer of the glass plate by screen printing in the manufacturing process. It is often formed by printing a conductive ink (silver paste) on the substrate. The characteristics of the formed circuit have the following problems due to the limitation of the characteristics of the sprint printing and the conductive ink. As a result, the quality and manufacturing cost of the touch screen are adversely affected. These problems are described in detail below.

(i) Uncontrollable uniformity and stability of resistance. The equation for calculating the resistor is as follows.

R = ρ * L / A = ρ * L / d * h

Where R is the resistance of the conductor, p is the resistance of the material forming the circuit, A is the sectional view of the circuit, d is the width of the circuit, and h is the thickness of the circuit.

Only width and thickness are parameters that affect the overall resistance of a known circuit because the length and material of the circuit passage are already known. In other words, a uniform circuit is the key to obtaining reliable resistance. However, when the conductive ink (eg, silver paste) is printed on the transparent resistive layer, the ink area of the conductive ink layer is generally 50% or less of the print area due to the size of the coincidence of the screen. As a result, non-uniform surfaces are formed at all positions on the printed circuit board. Moreover, viscosity, rubber roller pressure and braid sharpness, snap-off distances make it difficult to control thickness uniformity and circuit matching and other factors are known to those skilled in screen printing. This is particularly inappropriate for products with very high precision requirements for line space and edge quality. As a result, touch panels manufactured by prior art sprinting cannot satisfy the demands of quality. Similar problems arise in lithography and are not described here in detail.

(ii) Poor adhesion to the surface of the conductive glass. Drying and curing are performed on the transparent resistive layer after the conductive ink (e.g., silver paste) forming the circuit is printed on the transparent resistive layer by screen print processing.

The hardness of the circuit is measured with standard pencil hardness measuring equipment. According to this result, most of 4H pencil hardness is achieved by the glass-treatment. These circuits are so soft that they cannot hold other parts of the fabrication process, requiring considerable attention to manufacturing to prevent damage during processing of these circuits and an additional insulating layer overlaid on the glass to provide long term protection of these circuits. Should be.

(iii) bad weather and chemical properties. When forming a liquid silver paste for the screen printing process, this silver paste contains about 20% solvent. This solvent must be evaporated during the drying and curing process, which may be by plastics or ultraviolet light. However, residue is present when thick traces are printed. Residual solvents and moisture in the ink tend to lower the adhesion of silver to the transparent resistive layer, especially when printed over insulators or other solvents or UV based adhesives with exposed silver paste. The continuous exposure of the final product to moisture causes the adhesion of the silver resistive thin film interface to worsen, thus reducing the linearity of the touch screen.

(iv) Difficulties in processing and uncontrollable quality. Whether the conductive ink is UV curable or plastic, the difficulty of maintaining the consistency of the screen print ink is known to those skilled in the art. The viscosity check at the beginning of production is just beginning, and the viscosity of the ink changes continuously as the operation progresses. Moreover, recycling of unused ink is a common goal because the ink is expensive and the disposal is complicated by hazardous waste. Manufacturers' recommendations regarding proper collection and reconstitution of unused inks are unclear, resulting in uncertainty and consistency of traces printed with recycled unks.

(v) resistance connections. Reliable interconnection between the electrical circuits in the resistive and capacitive touch screens is important to maintain proper screen function and linearity. Circuits formed by printing conductive ink are interconnected to other electrical circuits by printing other circuits superimposed on the circuit and by conductive contacts or mechanical contacts contained in the matrix, which may or may not contain any kind of adhesive. Can be connected. Although there are many new and reliable interconnect systems for specific applications, the common use of these systems for connecting conductive ink circuits such as cables and first sheet to second sheet electrical contacts to other circuits is much more reliable. none.

Circuits formed by the use of the present invention can be welded to other circuits when formed on suitable substrates such as glass and various metals and the reliability of the interconnections to the circuits formed by the present invention is comparable to conductive ink circuits. Due to the increased hardness of the circuit, even if the printing, conductive tape or mechanical contact method is used, it can be greatly improved. The increased hardness reduces the deformation of the molded circuit material to maintain contact of the circuit with the interconnect material when the conductive particle interconnect system is used.

The potential effects of terms (i)-(v) on completed touchscreens are numerous.

(a) A drive trace (e.g., the previously mentioned conductive trace for the first or second resistive sheet) that connects the drive or control signal from the controller to a peripheral circuit adjacent to the edge of the first or second conductive sheet is the same. Has no resistance Although it is possible to design drive traces with the same resistance from the external cable bonding point to the connection point of the peripheral circuit of the edge portion of the resistive sheet, the manufacturing process does not produce the same resistance for each drive trace. In a 5-wire touchscreen, unequal drive trace resistances cause nonlinearity of the touchscreen. This nonlinearity can occur on both axes and will be proportional to the ratio of the screen resistance to the drive trace resistance for the two loads of the peripheral circuit to which the drive trace connects. Detailed descriptions of calculating these nonlinear sizes are known to those familiar with the art of these touchscreens.

(b) Peripheral circuits in both 4-wire and 5-wire touchscreen configurations apply potential along the entire position of a properly driven peripheral circuit adjacent the edge of the active area of the touchscreen. In a four-wire design, the bus bars are continuous. As noted above, the current flow caused by the potential applied between the bus bars at each end of the sheet is some point along a straight line parallel to the appropriate principal axis of the touchscreen near the interface between the busbar and the resistive sheet to which it is attached. The strengths should be the same at. This serves to make the resistance sheet have a continuous and uniform resistance. If the potential applied to each driven edge deviates at some point, the composite current will also be uneven. This causes nonlinearity in the touch screen. The change in direction from the design value and the deviation of the adhesion of the busbars to the base resistive sheet will change the dislocation to change the composite resistance at the considered position. Again, nonlinearity of the touch screen is caused. Although the design width of the busbars perpendicular to the direction of the current flow on the resistive sheet can be increased during etching of this problem, the mechanical size of the Turkish screen is unacceptably increased. In 5-wire touchscreens, peripheral circuits are often discontinuous and drive traces are attached to the peripheral circuits at nodes connecting two circuits in the middle or instead of a single bus bar as in a 4-wire case, but as described for the 4-wire case The same general principle applies. The poor consistency of the resistance of the components of the peripheral circuitry and some poor adhesion to the resistive thin film results in inconsistent current flow and the touch screen is nonlinear.

One supplier addresses the problem of screen printing quality and consistency of conductive inks by screen printing silver frits and then baking screen printed glass for the desired circuitry. Although the results of this process may have good quality, adhesion and hardness, this baking process temperature also adversely affects the resistance of the resist thin film surrounding the silver frit. Thus, the design of the silver frit pattern must be adjusted to compensate for variations in the resistance of the frit, resulting in a number of uncertainties in the design that ultimately adversely affect the linearity of the touch screen.

Therefore, it is desirable to provide a novel manufacturing process for manufacturing quality circuits between Turkish screen designers and manufacturers.

It is an object of the present invention to provide a method for providing a circuit layout on a touch panel using a metal plating technique, wherein a predetermined area is adjacent to an edge of a transparent conductive layer on a transparent glass substrate for forming a circuit using the metal plating technique. Uniformly coating the conductive metal or the conductive metal oxide onto the substrate. By using the present invention, the above drawback of printing conductive ink (for example, silver paste) on a transparent conductive layer of a glass substrate is overcome by prior art screen printing.

Moreover, the present invention provides a uniform thickness of the circuit, high hardness, good adhesion of the plating material to the base substrate. Resistant thin films, whether bare glass, have the advantages of improved functionality and chemical properties and solderability. Another advantage of the present invention is the low resistance of the plated metals compared to screen print conductive inks. This advantage is achieved in the design of the touch screen by reducing its movement trace and peripheral circuit electrode width, reducing the overall size of the touch screen to match the application requirements. Another advantage of the present invention is the reduced effect of heating and contamination of the resistive thin film, which can change the resistance compared to the baking process and the drive trace design of the touch screen electrode based on silver frit.

Other objects, features and advantages of the present invention will become apparent from the following description with reference to the accompanying drawings.

Referring to FIG. 6, a method of fabricating a circuit layout on a touch screen by using a metal plating technique according to a preferred embodiment of the present invention is described. The method includes consistently coating a conductive metal on the area adjacent to the edge of the resistive glass of the touch panel to form the required circuit by using metal plating technology.

In step 501 the spray rinse performed on the resistive glass 40 is described with respect to FIG. 7. First, the transparent resistive glass 40 is transferred to the rinse apparatus 60 to manufacture the touch screen. The resistive glass 40 includes a glass substrate 41 and a transparent resistive layer 42 made of IOT coated on the glass substrate 41. The rinsing device 60 performs spray rinsing, scrubbing and sending on the transparent resistance layer 42 to remove debris or dust.

In step 502, a resistive ink coating performed on the transparent resistive layer 42 after spray rinsing is shown in FIG. In detail, the resistive ink is coated on the designated central portion of the transparent resistive layer 42 to form the resistive ink layer 43 by printing.

In step 503, the etching performed on the resistive glass 40 is shown in FIG. In detail, the resistive glass 40 is transferred to the etch tin 60 to etch the transparent resistive layer 42. Finally, the areas where the resistive ink layer 43 is not coated on the transparent resistive layer 42 and the areas adjacent to the edges of the glass substrate 41 are removed.

In step 504, ink removal of the resistive ink layer 43 is shown with respect to FIG. In detail, the resistive glass 40 is transferred to the ink removing tank 80 to remove the resistive ink layer 43 coated on the transparent resistive layer 42.

In step 505, a mask formed on the transparent resistive layer 42 is described with reference to Fig. 11. In detail, after removing the ink, the mask 44 is formed and transparent by forming the mask 44 It is formed on the resistive layer 42. As a result, the predetermined portion 441 of the circuit to be formed is exposed.

In step 506, the sputtering performed on the predetermined portion 441 is described with reference to FIG. In detail, the predetermined portion 441 of the circuit to be formed by transferring the resistive glass 40 to the sputtering room 90 is sputtered. Finally, the conductive metal 91 (eg, silver ions) contained in the target 91 (eg, silver) is ionized and uniformly coated on the predetermined portion 441 by collision.

In step 507, forming a given circuit is described with respect to FIG. The required circuit is formed as soon as the conductive metal 91 is coated to a sufficient thickness on the desired portion 441. Next, the mask 44 is removed to form the required circuit 45 on the resistive glass 40.

In an embodiment, the circuit 45 has the advantage of uniform thickness because it is formed by uniformly coating the conductive metal 911 contained in the target 91. The circuit 45 may be mechanically narrower than the comparable circuit formed by the sprint printing of the conductive ink due to the thinner thickness of the more selected metal plating of the conductive ink and the lower resistance per unit area. Moreover, the circuit 45 has the advantages of stable impedance and high hardness. For example, a circuit formed of silver may pass 9H pencil hardness (even greater) in the experiment. In addition, as described above, in the embodiment, the required circuit 45 may be formed using conductive metal ( 911 is formed by directly coating the glass substrate 41 and the transparent resistive layer 42. As such, the circuit 45 has acceptable quality and no adverse effects of solvents or moisture. In addition, products with certain characteristics can be created while the operating parameters are set correctly in the relevant machine in the manufacturing process. This eliminates the problem of overly dependent on the experience of the printing operator. Moreover, in the metal plating process of the embodiment, there is no restriction on the effective working time for the target 91 and the contained conductive metal 911, which are imposed by the limitation of the prior art silver paste. In conclusion, the problem of cleaning the screen print mesh by filling with new ink regularly can be eliminated, thereby greatly improving the quality of the circuit 45 formed in the resistive glass 40 and increasing the yield, thereby greatly saving labor and time. .

Preferred embodiments of the invention have been described above. Although ITO may be replaced with another material without departing from the scope and spirit of the invention, the material contained in the transparent resistive layer is ITO in the examples. In addition, the sputtering and silver used in the embodiment of the present invention may be replaced with other suitable metal plating techniques and materials without departing from the scope and spirit of the present invention. Conductive metals other than the above (ie, silver) may be used to coat certain portions of the resistive glass 40 to form the circuit 45 required by metal plating. The circuit of the present invention formed in the region close to the edge of the glass substrate has good quality and reliable impedance. It hardly affects the performance of the touch panel. Referring to Fig. 14, another preferred embodiment of the present invention is shown. In the manufacturing process of the resistive glass 40, it is preferable to use a metal plating technique to form a circuit in the region adjacent the edge of the transparent resistive layer 42 of the glass substrate 41. In addition, another circuit 48 is formed in the region adjacent the edge of the glass substrate 41 using screen printing technology. In addition, the circuit 47 is connected to the circuit 48. As a result, the present invention not only improves the performance of the touch screen, but also greatly reduces the manufacturing cost.

Although the invention has been described in terms of specific embodiments, it will be apparent to those skilled in the art that various modifications and changes can be made without departing from the scope and spirit of the invention as set forth in the claims.

The present invention provides a uniform thickness of the circuit, high hardness, good adhesion of the plating material to the base substrate. Resistant thin films, whether bare glass, have the advantages of improved functionality and chemical properties and solderability. Another advantage of the present invention is the low resistance of the plated metals compared to screen print conductive inks. This advantage is achieved in the design of the touch screen by reducing its movement trace and peripheral circuit electrode width, reducing the overall size of the touch screen to match the application requirements. Another advantage of the present invention is the reduced effect of heating and contamination of the resistive thin film, which can change the resistance compared to the baking process and drive trace design of the touch screen electrode based on silver frit.

Claims (7)

In the method of manufacturing a circuit layout or touch screen using a metal plating technology, And uniformly coating the conductive metal or the conductive oxide on a predetermined area adjacent the edge of the transparent resistive layer on the transparent glass substrate to form the first circuit using metal plating technology. The method of claim 1, Forming a second circuit in an area of the glass substrate that is not plated with the projection conductive layer using a metal plating technique, the second circuit being electrically connected to the first circuit of claim 1. How to manufacture a touch screen. The method of claim 1, Forming a third circuit on an area of the glass substrate that is not coated with a transparent conductive layer using screen printing technology, the third circuit manufacturing a touch screen electrically connected to the first circuit. Way. The method of claim 1, And the projection resistance layer is made of ITO. The method of claim 1, The metal plating technology is a method of manufacturing a touch screen, characterized in that the sputtering. The method of claim 5, The conductive metal is formed by ionization by impinging the conductive metal contained in the target by sputtering. The method of claim 6, The target is a method of manufacturing a touch screen, characterized in that the silver.

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