This relates generally to touch sensors and, more specifically, to reduced contact processes for manufacturing touch sensors.
Many types of input devices are presently available for performing operations in a computing system, such as buttons or keys, mice, trackballs, joysticks, touch sensor panels, touch screens, and the like. Touch sensitive devices, such as touch screens, in particular, are becoming increasingly popular because of their ease and versatility of operation. A touch sensitive device can include a touch sensor panel, which can be a clear panel with a touch-sensitive surface, and a display device, such as a liquid crystal display (LCD) or organic light emitting diode (OLED) display, that can be positioned partially or fully behind the panel so that the touch-sensitive surface can cover at least a portion of the viewable area of the display device. The touch sensitive device can allow a user to perform various functions by touching the touch sensor panel using a finger, stylus, or other object at a location often dictated by a user interface (UI) being displayed by the display device. In general, the touch sensitive device can recognize a touch event and the position of the touch event on the touch sensor panel, and the computing system can then interpret the touch event in accordance with the display appearing at the time of the touch event, and thereafter can perform one or more actions based on the touch event.
Many processes have been developed to manufacture these touch sensors. For example, conventional roll-to-roll processes involve patterning electronic devices onto rolls of thin, flexible plastic or metal foil. These devices can then be removed from the roll using lithography or a physical cutting process. These roll-to-roll processes can reduce the amount of time and money required to manufacture touch sensors. However, when using rolls of plastic material in conventional roll-to-roll processing systems, the plastic material can be susceptible to particle defects due to the soft nature of the plastic. For example, small particles located on the rollers of the roll-to-roll system can introduce defects into the surface of the plastic film. Thus, improved touch sensor manufacturing systems and processes are desired.
This relates to systems and processes for reducing physical contact to sheets of base film in roll-to-roll processing of touch sensors. In one example, the process includes the use of rollers having rings circumferentially extending away from the roller and operable to contact the sheets of base film. The rings can be configured to contact portions of the sheet of base film away from touch sensor areas of the base film. The rings can further be configured to prevent the sheets of base film from contacting a shaft of the rollers. In another example, a reduced strength vacuum seal can be formed between a photo mask and the sheet of base film to reduce the amount of force applied to a passivation layer of the sheet of base film.
In the following description of the disclosure and examples, reference is made to the accompanying drawings in which it is shown by way of illustration specific examples that can be practiced. It is to be understood that other examples can be practiced and structural changes can be made without departing from the scope of the disclosure.
Various examples related to systems and processes for reducing physical contact to sheets of base film in roll-to-roll processing of touch sensors are disclosed. In one example, the process includes the use of rollers having rings circumferentially extending away from the roller and operable to contact the sheets of base film. The rings can be configured to contact portions of the sheet of base film away from touch sensor areas of the base film. The rings can further be configured to prevent the sheets of base film from contacting a shaft of the rollers. In another example, a reduced strength vacuum seal can be formed between a photo mask and the sheet of base film to reduce the amount of force applied to a passivation layer of the sheet of base film.
To sense a touch at the touch sensor 100, drive lines 101 can be stimulated by the stimulation signals 107 to capacitively couple with the crossing sense lines 103, thereby forming a capacitive path for coupling charge from the drive lines 101 to the sense lines 103. The crossing sense lines 103 can output touch signals 109, representing the coupled charge or current. When an object, such as a stylus, finger, etc., touches the touch sensor 100, the object can cause the capacitance Csig 111 to reduce by an amount ΔCsig at the touch location. This capacitance change ΔCsig can be caused by charge or current from the stimulated drive line 101 being shunted through the touching object to ground rather than being coupled to the crossing sense line 103 at the touch location. The touch signals 109 representative of the capacitance change ΔCsig can be transmitted by the sense lines 103 to the sense circuitry for processing. The touch signals 109 can indicate the touch region where the touch occurred and the amount of touch that occurred at that touch region location.
While the example shown in
Touch sensors, such as touch sensor 100, can be manufactured in various ways. For example, touch sensors can be manufactured using a roll-to-roll process that involves patterning the touch sensor onto rolls of thin, flexible plastic or metal foil. These devices can then be removed from the roll using lithography or a physical cutting process. To illustrate,
During the roll-to-roll process described above, the sheet of base film 201 can be transported over multiple rollers to move, shape, and position the sheet of base film 201 for use in the manufacturing process. For example,
To prevent or reduce the damage caused by the rollers in a roll-to-roll process, rollers having rings according to various examples of the present disclosure can be used. For example,
In some examples, shaft 505 and rings 503 can be made from a plastic or metal material. However, other types of rigid materials can be used. Shaft 505 and rings 503 can be separate elements, with rings attached to shaft 505. Alternatively, shaft 505 and rings 503 can form a unitary body. In some examples, the roller can include more than two rings. For example,
Rollers 501 and 601 described above can be used as any type of roller in a roll-to-roll system. For example, rollers 501 and 601 can be used as transportation, idling, dancer, tension, or nip rollers in a roll-to-roll processing system.
While the examples described above include rollers having 2 and 4 rings, it should be appreciated that any number of rings can be attached to the rollers (e.g., as illustrated by the image shown in
At block 803, the sheet of base film can be transported using rollers having a plurality of rings. In some examples, rollers similar or identical to rollers 501 or 601 can be used to transport the sheet of base film received at block 801. The rollers can include any number of rings circumferentially extending away from the shaft of the roller. As described above with respect to
At block 805, a plurality of touch sensors can be formed on the sheet of base film. In some examples, the touch sensors can be formed on the sheet of base film in a manner similar or identical to that described above with respect to touch sensors 200 and film 201. In particular, the touch sensors can be formed on the sheet of base film using any known patterning technique, such as deposition or photolithography. In some examples, at least a portion of the formation of the touch sensors at block 805 can be performed at the same time as the operation performed at block 803. For instance, the sheet of base film can be transported by the rollers while portions of the touch sensors are being deposited or otherwise formed on the sheet of base film.
In the roll-to-roll processes described above, a layer of transparent dry film resist (DFR) can be used as a passivation layer in the viewing area of a touch sensor. For example,
In some instances, the DFR passivation layer 907 can be soft and weak prior to a UV curing process. As a result, the DFR passivation layer 907 can be susceptible to damage from the physical contact with photo mask 909. For example, similar to the process using rollers, particles on photo mask 909 can damage the surface of the passivation layer 907 during contact.
To prevent or reduce the damage caused by photo mask 909 to passivation layer 907, exemplary process 1000 for determining a reduced strength seal, as shown in
At block 1003, an edge profile of a passivation layer generated by the plurality of vacuum seals can be evaluated. For example, edge profiles of passivation layers similar or identical to passivation layers 907 can be evaluated. The profile of the passivation layer can depend on the seal strength applied to the passivation layer by the seal formed at block 1001. Generally, a higher seal strength will generate a flatter edge profile, while a lower seal strength will generate a more wavy edge profile of the passivation layer.
At block 1005, an acceptable reduced vacuum seal strength can be identified based on the evaluated edge profiles. For example, based on the edge profiles of passivation layers 907 evaluated at block 1003, a minimum acceptable edge profile can be identified. The minimum acceptable edge profile can be determined using criteria dependent on the application of the touch sensor being formed. The vacuum strength that generated the minimum acceptable edge profile can be identified as the acceptable reduced vacuum seal strength.
The reduced vacuum seal strength identified at block 1005 can then be used in future manufacturing processes using the photo mask and base films used at blocks 1001 and 1003. In this way, the damage caused by the photo mask to the passivation layer can be eliminated or reduced by reducing the force applied to the passivation layer by the photo mask to an amount that is sufficient to produce an acceptable touch sensor. This is in contrast to conventional methods where the vacuum seal is set to the highest obtainable value to produce more desirable passivation edge profiles.
In some examples, the processes described above with respect to
Alternatively, in other examples, a protective film can be applied to the passivation layer of the touch sensor. For example,
One or more of the functions relating to the manufacturing of a touch sensitive device described above can be performed by a system similar or identical to system 1200 shown in
The instructions can also be propagated within any transport medium for use by or in connection with an instruction execution system, apparatus, or device, such as a computer-based system, processor-containing system, or other system that can fetch the instructions from the instruction execution system, apparatus, or device and execute the instructions. In the context of this document, a “transport medium” can be any medium that can communicate, propagate or transport the program for use by or in connection with the instruction execution system, apparatus, or device. The transport medium can include, but is not limited to, an electronic, magnetic, optical, electromagnetic or infrared wired or wireless propagation medium.
System 1200 can further include manufacturing device 1207 coupled to processor 1205. Manufacturing device 1207 can be operable to transport a sheet of base film using rollers similar or identical to those described above with respect to
It is to be understood that the system is not limited to the components and configuration of
Therefore, according to the above, some examples of the disclosure are directed to an apparatus for roll-to-roll processing for a touch sensor, the apparatus comprising: a plurality of rollers for transporting a plastic sheet through the apparatus, wherein each of the plurality of rollers comprises a plurality of rings circumferentially extending away from the roller and operable to contact the plastic sheet, and wherein the plurality of rings are positioned to contact the plastic sheet away from a touch sensor area of the plastic sheet. Additionally or alternatively to one or more of the examples disclosed above, the plurality of rings can be equidistantly separated. Additionally or alternatively to one or more of the examples disclosed above, the plurality of rollers can comprise one or more of transportation, idling, dancer, tension, or nip rollers. Additionally or alternatively to one or more of the examples disclosed above, the touch sensor area of the plastic sheet can correspond to an area of the plastic sheet at which a touch sensor is to be formed. Additionally or alternatively to one or more of the examples disclosed above, the touch sensor area of the plastic sheet can comprise a touch sensor. Additionally or alternatively to one or more of the examples disclosed above, the plurality of rings can be configured to prevent the plastic sheet from contacting a shaft portion of the plurality of rollers.
Some examples of the disclosure are directed to a method for roll-to-roll processing for a touch sensor, the method comprising: transporting a malleable sheet using a plurality of rollers, wherein each of the plurality of rollers comprises a plurality of rings circumferentially extending away from the roller; and contacting the sheet with plurality of rings, wherein the plurality of rings prevent the malleable sheet from contacting a shaft portion of the roller. Additionally or alternatively to one or more of the examples disclosed above, the plurality of rollers can be positioned to contact the malleable sheet away from a touch sensor area of the malleable sheet. Additionally or alternatively to one or more of the examples disclosed above, the method can further include forming a touch sensor within the touch sensor area of the malleable sheet. Additionally or alternatively to one or more of the examples disclosed above, the plurality of rollers can comprise plastic or metal.
Some examples of the disclosure are directed to a method comprising: forming a plurality of vacuum seals between a plurality of photo masks and a plurality of sheets of base film, wherein the plurality of vacuum seals have varying strengths; evaluating edge profiles of a plurality of passivation layers of the plurality of sheets of base film generated by the plurality of vacuum seals; and identifying an acceptable reduced vacuum seal strength based on the evaluated edge profiles. Additionally or alternatively to one or more of the examples disclosed above, the plurality of sheets of base film can comprise cyclo olefin polymer. Additionally or alternatively to one or more of the examples disclosed above, the acceptable reduced vacuum seal strength can correspond to a vacuum seal of the plurality of vacuum seals that produced a minimum acceptable edge profile of the plurality of passivation layers. Additionally or alternatively to one or more of the examples disclosed above, the method can further include manufacturing a plurality of touch sensors using the identified acceptable reduced vacuum seal strength. Additionally or alternatively to one or more of the examples disclosed above, the method can further include transporting the plurality of sheets of base film using a plurality of rollers, wherein each of the plurality of rollers comprises a plurality of rings circumferentially extending away from the roller and operable to contact the plurality of sheets of base film, and wherein the plurality of rings prevent the plurality of sheets of base film from contacting a shaft portion of the roller.
Some examples of the disclosure are directed to an apparatus comprising: a vacuum operable to form a vacuum seal between a photo mask and a sheet of base film; and a controller operable to cause the vacuum to generate the vacuum seal having an acceptable reduced vacuum seal strength, wherein the acceptable reduced vacuum seal strength is selected to generate a desired edge profile of a passivation layer of the sheet of base film. Additionally or alternatively to one or more of the examples disclosed above, the passivation layer can comprise a dry film resist. Additionally or alternatively to one or more of the examples disclosed above, the desired edge profile of the passivation layer of the sheet of base film can represent a minimum acceptable edge profile of the passivation layer. Additionally or alternatively to one or more of the examples disclosed above, the acceptable reduced vacuum seal strength can be determined based at least in part on a plurality of previous vacuum seals formed between a plurality of photo masks and a plurality of sheets of base film. Additionally or alternatively to one or more of the examples disclosed above, the apparatus can further include a plurality of rollers for transporting the sheet of base film through the apparatus, wherein each of the plurality of rollers comprises a plurality of rings circumferentially extending away from the roller and operable to contact the sheet of base film, and wherein the plurality of rings are positioned to contact the sheet of base film away from a touch sensor area of the sheet of base film.
Although the disclosure and examples have been fully described with reference to the accompanying drawings, it is to be noted that various changes and modifications will become apparent to those skilled in the art. Such changes and modifications are to be understood as being included within the scope of the disclosure and examples as defined by the appended claims.
Number | Date | Country | |
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61699118 | Sep 2012 | US |