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:
Mar. 12, 1996
Filed:
Nov. 14, 1994
Robert P Bishop, Pembroke, MA (US);
Paul L Hainey, Douglas, MA (US);
Stanley J Lukasiewicz, North Attleboro, MA (US);
Allan J Siuzdak, Cumberland, RI (US);
Robert E Luminello, Jr, Johnston, RI (US);
Vishwa N Shukla, North Attleboro, MA (US);
Texas Instruments Incorporated, Dallas, TX (US);
Abstract
A monolithic capacitive pressure transducer (12) is shown composed of ceramic material having a first closed cavity (12) separated from a surface thereof by a flexible wall member and a second closed cavity (16) defined by rigid wall members. Capacitor plates (32, 36; 40, 44) are formed on two opposed surfaces defining each cavity. Vias (33, 37; 41, 45) are formed extending from the capacitor plates to permit electrical connection therewith. The transducer is made by separately forming under pressure a diaphragm (20) and first and second base portions (22, 30) having recesses (24) in the top and bottom surfaces using ceramic powder coated with an organic binder. A metal layer is deposited on the pieces which are then joined together to form a single unit. A spacer (26) may be inserted in the recesses to ensure that a predetermined gap is maintained in each cavity during the joining operation. The parts are then debinderized by heating to a first temperature level to allow the binder organics, as well as the spacer organics if a spacer is employed, to be vaporized and/or decomposed and removed through the open pores of the diaphragm and base. The unit is then brought up to a sintering temperature to change it into a monolithic body and to convert the metallized layer into a conductive layer bonded to the ceramic.