The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 26, 1989
Filed:
Oct. 20, 1988
George Trenkler, Providence, RI (US);
Richard G Delagi, Sharon, MA (US);
Francois A Padovani, Westwood, MA (US);
Donald L Winslow, Raynham, MA (US);
Texas Instruments Incorporated, Dallas, TX (US);
Abstract
A shield for electromagnetic radiations comprising a laminated sheet having exterior layers of copper which sandwich an interior layer of a ferromagnetic alloy taken from the class consisting of nickel-iron compounds having from about 42 to about 80 percent nickel by weight and iron as a substantial portion of the remaining material. The layers are metallurgically bonded to each other by sintering or the like. According to a second embodiment, a laminated sheet is provided having exterior layers of copper which sandwich plural interior layers of ferromagnetic material, the layers of ferromagnetic material having progressively higher permeability and being capable of shielding interference of progressively lower energy level when travelling in a direction away from the direction of the source of interference. A typical laminated sheet in the direction away from the source of interference is copper/permendur/80/copper. A further typical such laminated sheet in the direction away from the source of interference is copper/49/80/copper. In those instances where it is known that no high frequencies will be encountered, the copper layers can be removed. It is necessary that each successive layer in the direction away from the source of interfering electromagnetic radiations be at maximum permeability range at a lower interference energy level.