Patent Application
20060137813
The present invention generally relates to manufacturing processes and methods wherein layers are added to a flexible webbing, and more particularly relates to registration of webs and layers and cutting of the same.
The popularity of touch screens has increased significantly over the past several years. Many different technologies have been explored in an effort to produce a high-quality touch sensor that is reliable and cost effective. Examples of touch sensor technologies include capacitive, resistive, near field imaging (NFI), acoustical wave, infrared, and force. Common applications for touch sensors include computer monitors and mobile and handheld devices, such as personal digital assistants (PDAs) and tablet computers.
Touch sensors typically possess features and qualities that are unique for a given technology. Each type of touch sensor technology presents specific challenges related to, for example, the recognition of a touch input, the determination of the position of a touch input to a touch sensitive structure of the sensor, reliability, size, weight, and cost.
Most touch sensors are embedded in an electrical membrane panel to be used in a monitor or handheld device. Electrical membrane panels of the type to which the present invention relates include spaced first and second conductive circuits that are formed on separate layers of flexible polymer-based film, webbing, or insulating laminate layers. One common method for producing this type of panel is to form the circuits on individual sheets of plastic film and then join the two sheets of film together after the two circuits have been completely formed. The sheets may be joined together using, for example, a lamination process. This technique can be expensive and entail difficult and time-consuming hand lay-up and registration operations, particularly when the plastic films are very thin, for example, in the range of about 1 mil to 5 mils thick. The separate films are typically hand registered in stacks and then laminated with rollers or in a press or autoclave under heat and pressure.
Another technique includes laminating rolls of web with other layers of web or laminate. The roll of completed product may be cut to any desired length. This technique has certain drawbacks as well. A circuit positioned in the continuous roll of laminated webbing can be difficult to access for the purpose of coupling to a circuit board or to a hard wire connection. Circuit parts can be positioned such that the tail area of a part is exposed along a side of the web for connection as described in U.S. Pat. No. 5,062,016. When this technique is used for a grid type circuit in which conductive traces are aligned in orthogonal X and Y directions, leads to the conductive traces must extend to the sides of the web in order to be exposed for later connection. This restriction on the routing and access points of the conductive traces can result in limitations related to manufacturing efficiency, cost-effective production of parts, and design options for the circuit components and electronic devices that use those components.
The invention generally relates to systems and methods that are used to generate multi-layered circuit assemblies. The multi-layered circuit assemblies are of the type commonly formed as a continuous roll of various layers of webbing, laminate, and components or patterns positioned between the webbing and laminate layers. The multi-layered circuit may include a single layer of components or multiple layers of components with intervening layers of webbing or laminate material. The invention provides, in some respects, techniques that allow for more efficient utilization of web area on the webbing. For example, components can be positioned such that the tail area of a part can be located in the middle of the webbing rather than along the edge of the webbing and still be exposed for future connection.
The invention effectively eliminates the need for manual handling of the webbing or laminate layers just before and during engagement of the layers, for which handling is required in many known processes to ensure proper alignment of the components relative to the layers. The invention also eliminates the need for equipment such as an autoclave, press, or stretching machinery due to the automated registry of the layers and nipping of the layers together.
One aspect of the invention relates to a method of manufacturing a multi-layered circuit assembly. The assembly includes a webbing member, a component, and a laminate layer. The method includes providing a roll of the webbing member with the component positioned thereon, providing a separate roll of the laminate layer, and monitoring a position of the component on the webbing member with a position detection device. The method also includes modifying a portion of the laminate layer at a location that is based on the monitored position of the component on the webbing member, and coupling the laminate layer to the webbing member to provide a continuous sheet of multi-layered circuit. The multi-layered circuit is formed with the component positioned between the webbing member and the laminate layer and aligned with the modification in the laminate layer.
Another aspect of the invention relates to a method of generating a multi-layered product using a web lamination machine. The machine includes a position detection device, first and second nip rollers, and a modifying device. The method includes feeding a continuous sheet of a first layer to the first nip roller, the first layer including at least one component positioned thereon, and detecting the position of the component to determine a position of the component relative to the first nip roller. The method also includes feeding a continuous sheet of a second layer to the second nip roller, the first and second nip rollers directing the first and second layers into engagement with each other to form a continuous sheet of multi-layered product. The method still further includes forming an aperture in the second layer based on the determined position of the component such that the component is exposed within the aperture in the multi-layered product.
Another aspect of the invention relates to a method of generating a multi-layered product using a web lamination machine. The machine includes a position detection device, first and second nip rollers, and an altering device. The method includes feeding a continuous sheet of a first layer to the first nip roller, the first layer including a predetermined pattern, and detecting the position of at least a portion of the predetermined pattern with the position detection device to determine a characteristic of the portion of the predetermined pattern. The method also includes feeding a continuous sheet of a second layer to the second nip roller, the first and second nip rollers directing the first and second layers into engagement with each other to form a continuous sheet of multi-layered product, and altering the second layer with the altering device prior to the second layer being fed to the second nip roller based on the determined characteristic of the portion of the predetermined pattern.
Another aspect of the invention relates to a system for generating a multi-layered circuit assembly. The system includes a first roll support configured to support a continuous roll of webbing, the webbing having at least one circuit component positioned thereon, and a second roll support configured to support a continuous roll of laminate layer. The system also includes first and second nip rollers configured to direct the webbing and laminate layers, respectively, into engagement with each other to form a continuous sheet of multi-layered product. A position detection device of the system is positioned between the first roll support and the first nip roller. The position detection device is arranged and configured to monitor a position of at least one circuit component relative to the first nip roller. A modifying device of the machine is positioned between the second roll support and the second nip roller. The modifying device is arranged and configured to modify the laminate layer based on the monitored position of the circuit component.
The present invention provides novel methods and apparatuses for enabling multi-layered circuits to be formed on webs such that electrical connection to the various layers of the multi-layered circuit can be exposed for subsequent connection to each other or external circuitry. In one of its aspects, the invention provides a machine vision registered cutting during the lamination process to expose key areas of the circuit that would otherwise be covered by the laminate layer.
The present invention also provides an efficient solution to the problem of precession when attempting to create multi-layered circuits in web form. In the case where two circuit layers are formed on two separate webs, each in a succession of images, image precession will occur when the two webs are laminated together in register. This happens due to the fact that the pitch between images cannot be exactly maintained, and any small error, when accumulated through many images, will cause the register to shift. There are methods to solve this problem, such as stretching of one web before laminating the images, or cutting the images of one web after each image is laminated, although these, are typically slow and costly processes. Moreover, many web materials cannot be stretched in any effective manner. The present invention allows for a circuit layer to be formed; for a laminate to be adhered to this circuit, with the further ability to expose portions of that first circuit; and for second and other subsequent circuits to be formed in register to each image of the first image. These circuits may be formed by screen printing, photolithography or other imaging techniques.
The methods and apparatuses of the present invention provide for the formation of multi-layered circuits to be formed on continuous webbing members with more efficient utilization of web area. For example, components of the circuit can be positioned such that a connection point of a component can be in the middle area of the web rather than near the edge of the web and still be exposed. This advantage of the present invention is especially useful when dealing with small components. When using small components for construction of a multi-layered circuit and only the edges of the webbing member are available to expose the circuit components, only a row of components can be positioned along each side edge of the web so that the connection point of the components are exposed along the web side edges. The present invention permits positioning of multiple rows on the web that are aligned in any desired orientation relative to a side edge of the web.
A further advantage of the invention is reduced cost of manufacturing, in particular those costs associated with handling the layered products used for assembly of the multi-layered circuit. This advantage may be achieved by using software and machine vision to align the cutting pattern with components of the circuit. In one example, a standard laminate width can be used regardless of the component configuration being run, and only a specified software file is needed in conjunction with that component configuration to run the system/machine. Further, setup times can be greatly reduced as compared to a system in which numerous rolls of pre-slit laminate layers must be aligned with component layouts wherein the slits have a defined width and lane arrangement to correspond to the pattern of components on the webbing to which the laminate layer is secured.
Referring now to
The system 10 also includes first and second nip rollers 28, 30, first and second encoders 32, 34, a position detection device 36, a modifying device 38, and rollers 40, 42, 44, 46. The first encoder 32 and position detection device 36 are positioned between the first roll 20 and the first nip roller 28. The second encoder 34, modifying device 38 and rollers 40, 42 are positioned between the second roll 22 and the second nip roller 30. The third roller 44 is positioned between the first and second nip rollers 28, 30 and the roll 24. The roller 46 is positioned between the encoder 34 and the roll of release liner 26.
In one example, the first roll of continuous layer 21 includes a pattern thereon that is monitored by the position detection device 36 as the continuous layer 21 moves in the direction A toward the fist nip roller 28 and the nip or engagement point 29 between the first and second nip rollers 28, 30. This pattern may be defined in many different ways. In one example, the pattern may be defined by conductive traces, while in another example the pattern is defined by an arrangement of circuit components that includes at least one component mounted on a surface of the layer 21. The pattern is arranged and configured for detection by the position detection device 36.
Preferably, the position detection device 36 maintains a fixed position or travels along a known path whereby it is possible to determine the distance between the point at which the pattern is detected and the nipping point at which the first and second continuous layers 21, 23 contact each other between the first and second nip rollers 28, 30. The position detection device 36 may be, for example, any machine vision device such as a digital video camera, or a simple light sensor used with a mark or hole in the web for each image.
The encoders 32, 34 may be used to track the absolute distance traveled by the web in question so that the precise location of the pattern being detected can be predicted when it arrives at the nip. This certainty enables the precise-location of the modification to the laminate layer (discussed further below), resulting in tight registrations between the component and the modification. Thus, the position detection device 36 and encoders 32, 34 can be used to determine a precise distance between where the pattern is positioned relative to the first layer 21 and the nip point 29.
The modifying device 38 may be positioned at any location along the length of the second layer 23 between the second roll 22 and the second nip roller 30. In the embodiment shown in
The modifying device 38 can be any type of device capable of modifying or altering a feature of the second layer 23 using such techniques as, for example, cutting, forming, repositioning, shaping, depositing upon, or any other desired means of modifying the second layer in some way. The terms “cut” and“cutting” may be used interchangeably with the terms “modify” and “modifying” throughout this document, but such use is not intended to limit the scope of the terms “modify” or “modifying” to a single definition.
Referring now to
In the embodiment shown in
In one embodiment, the aperture 62 has a size of about 2.5 cm by 2.5 cm (1 square inch), but can have larger or smaller dimensions in different applications. Larger aperture sizes may result in a layer that is weakened to the extent that the layer becomes deformable under stresses resulting from the layer being passed through the system to the nip point. The smaller the size of aperture 62, the greater the requirement for accuracy and precision in forming the aperture at a location that will properly align with the feature (e.g., component or pattern) on the opposing layer. In one example, apertures having a size in the range of 1 to 5 mm on a side are within the capabilities of the invention.
When using the example systems and process described above, it is possible to provide access to the ends of the tails 54A, 54B at any position across the width and along the length of the continuous web 50. In contrast, many known processes require alignment of the component such that the portion of the component desired for exposure must be aligned along a side edge of the continuous layer. If such a requirement were imposed upon the embodiment shown in
The first steps of the method shown in
If the resultant multi-layer product is to be transparent, the web should be a transparent or at least translucent plastic film. Any plastic film suitable for membrane switches and touch panels can be used for the webbing member and laminate layer, with a polyester film such as Mylar® sold by Dupont being preferred. Other films including nylons, polycarbonates, polyethylene;naphalate, polyethersulphone; vinyl, polyimide, polypropylene, paper, etc., can be used. The webbing member and laminate layer can be a thin film having a thickness on the order of, for example, about 1 mils to about 10 mils thick. Thicker film layers may be used for the webbing member to provide additional support for mounting of the component. One advantage of the present invention is that it can be used with relatively thin webbing and laminate layers to produce a relatively thin multi-layer product.
The webbing member and laminate layer can each be a single layer of film, such as plastic film, or may each be a multi-layer film. The laminate layer may include a separate release liner that is applied over an exposed surface of adhesive on one side of the laminate layer. The liner can be stripped away from the laminate layer prior to the webbing member and laminate layer coming into engagement with each other, thereby providing a means of securing the webbing member and laminate layer together with the component positioned therebetween.
The webbing member and laminate layer are typically provided as a roll of plastic film. Such rolls of film are typically several hundred feet long to several thousand feet long, making it possible to form a continuous multi-layer product having a desired length. Initially, the webbing member must have a length long enough to accommodate at least one component. It is also envisioned that the webbing member may be long enough to include a plurality of rows and columns of components positioned along the length of the webbing member.
The next step of the method shown in
The next step of the method shown in
The use of precision cutting devices such as a galvo-based beam delivery system makes it possible to cut the laminate layer while the laminate layer is moving at a relatively high speed. In one example, the laminate layer is moving at a speed of at least 10 feet per minute, and more preferably at a speed of about 20 to 50 feet per minute. Rotary Die Cutting could be used for much faster speeds, on the order of hundreds of feet per minute but would require hard tooling for every part number and significant time for changeovers and setups. Intermittent motion flat die cutting may cause web control and tension problems as well as potentially leaving witness marks on the assembly at locations where the web is stopped inside the nip, unless an accumulator system was added to the machine to allow continuous movement of the laminating rollers while part of the web was stationary for flat die cutting. Speeds even greater than 50 feet per minute are possible depending on the power and speed of the cutting system and the complexity of the patterns to be cut. Alternatively, the web can be stopped for die-cutting and then re-started.
The location on the laminate layer at which the cutting device conducts cutting is determined in part based on information provided by the monitoring device. As with the position of the monitoring device, the position of the cutting device relative to the engagement point between the webbing member and laminate layer must be known at all times. With these distances known, it is possible to cut the laminate layer at a location that corresponds to that portion of the component that is to be exposed in the continuous multi-layer product. This process of real-time monitoring of a position of the component and performing a real-time cutting function based on the monitored position provides certain advantages. One such advantage is that a high degree of precision can be provided for the location of the cut so that the cut aligns properly with a portion of the component that is desired for exposure. Another advantage is the elimination of handling and positioning of the laminate layer relative to the webbing member after cutting is performed. A still further advantage is that each individual component is individually registered with a cut in the laminate layer, making it possible to account for minor errors in positioning of the component on the webbing member or setting up the system for various patterns and arrangements of components on the webbing member. It is desirable that in the case in which sequential images have been formed on the first web, that the cutting device is cutting a pattern that will join with the specific image that the position detection device is monitoring. This will ensure that any small variations in pitch from image to image will not affect registration.
The next step of the method shown in
Further steps of the method of
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In the methods described in
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There have thus been described several new processes for the manufacture of a continuous multi-layer product in which one layer of the multi-layer product is altered in some way based upon a monitored aspect of another layer of the multi-layer product. One aspect of the new processes relates to the real-time monitoring and altering steps, which provides certain advantages described above with reference to the several Figures. The processes and system provide an efficient method for manufacturing a continuous multi-layer product, and are especially useful for production of a multi-layer product that incorporates multiple thin film layers.
The above specification, examples and data provide a complete description of the manufacture and use of the composition of the invention. Since many embodiments of the invention can be made without departing from the spirit and scope of the invention, the invention resides in the claims hereinafter appended.
