| Security tag & method using a flowable material -> Monitor Keywords |
|
|
  Security tag & method using a flowable materialUSPTO Application #: 20060185790Title: Security tag & method using a flowable material Abstract: A method of fabricating a tag includes the steps of applying a first patterned adhesive to the surface of the substrate and applying a first electrically conductive foil to the first patterned adhesive. A portion of the first electrically conductive foil not adhered to the first patterned adhesive is removed and a second patterned adhesive is applied to a portion of a surface area of the tag. A preformed second electrically conductive foil is applied to the second patterned adhesive to adhere the second electrically conductive foil to the surface of the substrate and portions of the first and second electrically conductive foils are electrically coupled to each other to form a tag circuit. A second patterned adhesive can be disposed between the first and second electrically conductive foils. (end of abstract) Agent: Caesar, Rivise, Bernstein, Cohen & Pokotilow, Ltd. - Philadelphia, PA, US Inventors: Eric Eckstein, Andre Cote USPTO Applicaton #: 20060185790 - Class: 156267000 (USPTO) The Patent Description & Claims data below is from USPTO Patent Application 20060185790. Brief Patent Description - Full Patent Description - Patent Application Claims
RELATED APPLICATIONS [0001] This is a utility application based upon provisional application Ser. No. 60/611,349, filed on Sep. 20, 2004 entitled "Security Tags, Apparatus and Methods for Producing Same", which was based upon provisional application Ser. No. 60/547,235, filed on Feb. 23, 2004 entitled "Security Tags, Apparatus and Methods for Producing the Same." Applicant hereby claims for this utility application the benefit of the filing date of the provisional application whose entire disclosure are incorporated by reference herein. SPECIFICATION Background of the Invention [0002] 1. Field of Invention [0003] The present invention relates to security tags and, more particularly, to a process for making an electrical circuit for use in a security tag. [0004] 2. Description of Related Art [0005] Security tags are tags that are adapted to reflect electromagnetic energy in order to indicate their presence within a detection zone. They can be associated with an item in order to monitor the item. Two common types of security tags are resonant inductor/capacitor (LC) circuit based tags and dipole antenna based tags. Both of these types of tags respond to an electromagnetic scanning signal by providing a response signal. The response signal is detectable by suitable signal detection equipment for indicating the presence of a security tag within a scanned detection region or interrogation zone (sometimes referred to as an "interrogator"). In particular, the tag provides a response signal when stimulated by the electromagnetic field at a predetermined tag frequency. A disturbance of the electromagnetic field caused by the response signal is detectable by the signal detection equipment that is tuned to a predetermined detection frequency and is located in the detection region or zone. The signal detection equipment can be adapted to provide an alarm when an un-deactivated security tag is detected, such as commonly accomplished in Electronic Article Surveillance (EAS) applications. [0006] LC Security Tags [0007] LC resonant tags commonly operate in the RF range. The LC circuits of such tags provide a response signal by resonating in response to the electromagnetic energy applied to them at their resonant frequency. In order to detect the presence of an LC based tag in a detection region or zone, the frequency of the electromagnetic energy applied to that region or zone is swept through a range of frequencies that includes the predetermined tag frequency. The LC circuit of the tag resonates when the swept frequency of the applied energy reaches the predetermined tag frequency. A security tag of this type is disclosed in U.S. Pat. No. 5,861,809, entitled "Deactivateable Resonant Circuit," issued on Jan. 19, 1999 to Eckstein, et al. (Eckstein). [0008] Typically, the LC circuits of LC-based resonant tags are generally planar circuits formed of conductor layers and dielectric layers. One of the conductor layers includes one plate of a capacitor and a spiral conductor coil forming an inductor disposed upon a surface of a dielectric layer. One plate of the capacitor is connected to a proximal end of the coil. A second conductor layer is formed on the opposing surface of the substrate to serve as the second plate of the capacitor. The substrate thus serves as the dielectric of the capacitor. A through connection between the second plate and the distal end of the coil completes the fabrication of the inductor/capacitor (LC) resonant circuit. The two conductor layers can be formed using well known photo-etching techniques. Alternately, the conductor layers can be formed by laser cutting or arc cutting techniques as disclosed in U.S. Pat. No. 5,920,290, entitled "Resonant Tag Labels and Method of Making the Same," issued to McDonough on Jul. 6, 1999. [0009] Other patents disclosing similar technology include U.S. Pat. Nos. 6,214,444, 6,383,616 and 6,458,465 assigned to Kabushiki Kaisha Miyake (Miyake) which teach a method for making resonant tags in which a circuit-like metallic foil pattern was adhered to a dielectric film prepared from a liquid resin by a coating process. A circuit-like metal foil pattern on one side of the dielectric film is aligned with a circuit-like pattern on the other side of the dielectric film so as to form a capacitor. The dielectric film had openings configured similarly to and aligned with openings in the circuit-like metal foil, wherein the configuration of the circuit-like metal foil pattern and the dielectric film was generally spiral in configuration. [0010] U.S. Pat. No. 6,618,939 and Publication No. US 2004/0025324, also assigned to Miyake, teach a method for making resonant tags wherein a metal foil having a thermal adhesive applied to at least one face is stamped out into a circuit-like shape and adhered to a base sheet. The metal foil is stamped onto a metal foil portion having a predetermined shape while being passed through a die roll having a stamping blade with a predetermined shape. A transfer roll is in contact with the die roll to function as a die back-up roll and to hold the metal foil portion obtained by the stamping operation onto the surface of the transfer roll by suction holes formed in the transfer roll. The stamped out metal foil portion is thermally adhered to the base sheet in contact with the transfer roll by an adhesive roll in contact with the transfer foil through the base sheet. [0011] Another patent assigned to Miyake, U.S. Pat. No. 5,645,932, teaches a method for making resonant tags in which a laminate was fabricated by adhering a metal foil coated with hot-melt adhesive resin film to a carrier sheet such as paper. The metal foil of the laminate was stamped out using a stamping die to provide a predetermined circuit-like pattern. The metallic foil side of the laminate was superposed on a support such as a plastic film. The circuit-like metallic foil was then transferred to the surface of the support by heating the circuit-like pattern from the support side of the carrier sheet side. [0012] U.S. Pat. No. 4,730,095 (the '095 patent), assigned to Durgo A G, teaches a method of producing a plurality of equal printed circuits on a common, planar insulating carrier having an electrically conducting layer on at least one of its surfaces. The electrical circuits have a spirally arranged conductor trace forming at least one induction coil and at least one capacitor. [0013] In the '095 patent, a plurality of reference perforations are applied to the insulating carrier using a laser and a conducting layer is applied to at least one side of the carrier. A portion of the conductive layer having the rough contours of a circuit element is removed. The circuit element can be an inductive coil and the remaining portion of the conductive layer can have a shape and size approximating the outside dimensions of the coil. Computer controlled lasers are then used to remove further portions of the conductive layer to provide conductive tracks which form the electrical circuit. The electrical values of the circuit are determined and compared with design values. The electrical values can be corrected using the lasers if necessary. [0014] U.S. Pat. No. 4,900,386, also assigned to Durgo A G, teaches a method for producing labels incorporating electrical oscillating circuits wherein parts of the circuits are initially punched out of a center area of a metal web covered by an adhesive. The center area is then covered by an insulating material web for handling stability in order to punch out the part of the circuit to be located at the outer web area. A covering foil is laminated onto the metal web and the parts of the Cortez to be located on the reverse side are applied onto the insulating material web and connected electrical to the remainder of the circuit. [0015] This method of fabricating the elements of an LC-based tag has several problems. One particularly significant problem is the cost of the substrate itself and the design limitations placed on the tag by various substrate requirements. Since the substrate is a structural element that must provide most of the structural integrity of the tag, there are minimum requirements on the mechanical strength of the materials that can be used to form the substrate. This limits the number of different kinds of materials that can be used to form substrates. U.S. Pat. No. 5,142,270, entitled "Stabilized Resonant Tag Circuit and Deactivator," issued to Appalucci et al. on Aug. 25, 1992, discloses selected considerations with respect to substrate strength. [0016] Additionally, the requirement that the substrate provide sufficient mechanical strength to the response circuit imposes a requirement that the substrate be formed with a minimum thickness. This limits the amount of capacitance that can be provided on a unit area of substrate surface. U.S. Pat. No. 5,682,814, entitled "Apparatus for Manufacturing Resonant Tag," issued to Imaichi, et al. on Nov. 4, 1997, discloses the relationship between dielectric thickness and capacitance. The material of the substrate must also be capable of withstanding the photo-etch baths required to form the elements of the LC circuit. This factor places additional limitations on the materials that can be used in the design of substrates. [0017] Under these circumstances, it may not be possible to optimize the dielectric properties of the substrate when selecting a dielectric material or a dielectric thickness for use as a component of a security tag. The inability to optimize the dielectric properties of the dielectric materials results in many problems, such as increased capacitor size, lower tag yields and hence, increased costs for the fabrication of security tags. [0018] Other problems encountered in forming the elements of an LC-based tag arise from the photo-etching process. For example, the photo-etching process can be slow and quite expensive. An example of a system attempting to obtain high speed printing of security tags using a photo-etch process is U.S. Pat. No. 3,913,219, entitled "Planar Circuit Fabrication Process," issued to Lichtblau on Oct. 25, 1975. Fine tuning of the capacitance within an LC-based tag, by adjusting the amount of conductive material forming a capacitor plate after the initial fabrication step thereof, is disclosed in U.S. Pat. No. 4,369,557, entitled "Process for Fabricating Resonant Tag Circuit Construction," issued to Vandebult on Jan. 25, 1983. [0019] In addition to the high cost of the photo-etching process itself, the fact that the process requires environmentally unsafe chemicals creates disposal problems for the spent materials. As will be appreciated by those skilled in the art, the procedures required to safely dispose of spent photo-etching materials significantly increase the costs of producing security tags. Furthermore, substantial amounts of conductive material must be removed by the etching process when forming the conductor layers of the tag. This further increases the costs of the fabrication process as a result of the waste of conductive material and/or the complications of performing various recovery processes, such as recovering aluminum, when forming the tags. [0020] An additional area of difficulty encountered when using the prior art methods for forming security tags is accurate control of the amount of the capacitance in the tags. Inaccurate capacitance can result from variations in the dielectric constant, variations in the thickness of the dielectric material and variations in the alignment of the capacitor plates. The dielectric constant of the material can normally be specified and accurately provided for the materials used in the fabrication of tags. Additionally, the dielectric constant of a material can be tested prior to the fabrication process. Furthermore, the thickness of the dielectric material can normally be controlled by conventional coating technology and tested prior to the fabrication process. [0021] Thus, the most common problem in accurately controlling the capacitance is the alignment of the circuit elements making up the tag. For example, when the second plate of the capacitor is disposed on the second surface of the substrate or over the first plate, much care must be taken to make certain that the second plate is correctly aligned with the first plate. Failure to align the plates correctly results in inaccuracies in the amount of capacitance produced since the actual area of overlap of the plates determines the capacitance. This causes inaccuracies in the frequency at which the tag resonates. Often this results in an upward shift in resonant frequency. Continue reading... Full patent description for Security tag & method using a flowable material Brief Patent Description - Full Patent Description - Patent Application Claims Click on the above for other options relating to this Security tag & method using a flowable material patent application. ###  How KEYWORD MONITOR works... a FREE service from FreshPatents1. Sign up (takes 30 seconds). 2. Fill in the keywords to be monitored. 3. Each week you receive an email with patent applications related to your keywords. Start now! - Receive info on patent apps like Security tag & method using a flowable material or other areas of interest. ### Previous Patent Application: Method of cutting multilayer body, method of forming multilayer container, and multilayer formed product Next Patent Application: Kit of materials for laser welding and method for laser welding Industry Class: Adhesive bonding and miscellaneous chemical manufacture ### FreshPatents.com Support Thank you for viewing the Security tag & method using a flowable material patent info. IP-related news and info Results in 0.15261 seconds Other interesting Feshpatents.com categories: Tyco , Unilever , Warner-lambert , 3m |
||
