Wireless telemetry electronic circuit board for high temperature environments

• US 8,023,269 B2
• Filed: 08/15/2008
• Issued: 09/20/2011
• Est. Priority Date: 08/15/2008
• Status: Expired due to Fees

• Current Assignee: Cree Fayetteville, Inc. (Wolfspeed, Inc.)
• Original Assignee: Siemens Energy Incorporated (Siemens AG), Arkansas Power Electronics International, Inc. (Wolfspeed, Inc.)
• Inventors: McPherson, Brice, Schupbach, Roberto, Western, Bryon, Kulkarni, Anand A., Subramanian, Ramesh, Roesch, Edward R., Mitchell, David J., Lostetter, Alexander B., Fraley, John R., Waits, Rod
• Primary Examiner(s): Chen; Xiaoliang
• Application Number:
  US12/192,340
• Publication Number:
  US 20100039779A1
• Time in Patent Office: 1,131 Days
• Field of Search: 361/739, 361/321.1, 361/737, 361/743, 361/760, 361/767, 361/770, 174/255, 174/521, 174/557, 257/100, 257/531, 257/678, 257/728, 297/39, 298/40, 438/125, 438/637, 428/383
• US Class Current: 361/739
• CPC Class Codes: G01K 1/024 for remote indication
• CPC Class Codes: G01K 13/02 for measuring temperature of moving fluids or granular materials capable of flow
• CPC Class Codes: G01K 13/024 of moving gases
• CPC Class Codes: H01L 2224/05644 Gold [Au] as principal constituent
• CPC Class Codes: H01L 2224/45015 being circular
• CPC Class Codes: H01L 2224/45139 Silver (Ag) as principal constituent
• CPC Class Codes: H01L 2224/45144 Gold (Au) as principal constituent
• CPC Class Codes: H01L 2224/48472 the other connecting portion not on the bonding area also being a wedge bond, i.e. wedge-to-wedge
• CPC Class Codes: H01L 2224/48644 Gold (Au) as principal constituent
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/01322 Eutectic Alloys, i.e. obtained by a liquid transforming into two solid phases
• CPC Class Codes: H01L 2924/13062 Junction field-effect transistor [JFET]
• CPC Class Codes: H01L 2924/20751 larger or equal to 10 microns less than 20 microns
• CPC Class Codes: H01L 2924/20752 larger or equal to 20 microns less than 30 microns
• CPC Class Codes: H01L 2924/3011 Impedance
• CPC Class Codes: H05K 1/092 Dispersed materials, e.g. conductive pastes or inks
• CPC Class Codes: H05K 2201/10674 Flip chip
• CPC Class Codes: H05K 2203/0186 Mask formed or laid on PCB, the mask having recesses or openings specially designed for mounting components or body parts thereof
• CPC Class Codes: H05K 2203/049 Wire bonding
• CPC Class Codes: H05K 2203/0557 : Non-printed masks
• CPC Class Codes: H05K 2203/1126 : Firing, i.e. heating a powder or paste above the melting temperature of at least one of its constituents
• CPC Class Codes: H05K 2203/167 : Using mechanical means for positioning, alignment or registration, e.g. using rod-in-hole alignment
• CPC Class Codes: H05K 3/102 : by bonding of conductive powder, i.e. metallic powder H05K3/12 takes precedence
• CPC Class Codes: H05K 3/1291 : Firing or sintering at relative high temperatures for patterns on inorganic boards, e.g. co-firing of circuits on green ceramic sheets
• CPC Class Codes: H05K 3/321 : by conductive adhesives
• CPC Class Codes: H05K 3/328 : by welding
• CPC Class Codes: Y10T 29/49128 : Assembling formed circuit to base
• CPC Class Codes: Y10T 29/49139 : by inserting component lead or terminal into base aperture
• CPC Class Codes: Y10T 29/49144 : by metal fusion
• CPC Class Codes: Y10T 29/53174 : Means to fasten electrical component to wiring board, base, or substrate
• CPC Class Codes: Y10T 428/2947 : Synthetic resin or polymer in plural coatings, each of different type

Abstract

A circuit assembly (34) resistant to high-temperature and high g centrifugal force is disclosed. A printed circuit board (42) is first fabricated from alumina and has conductive traces of said circuit formed thereon by the use of a thick film gold paste. Active and passive components of the circuit assembly are attached to the printed circuit board by means of gold powder diffused under high temperature. Gold wire is used for bonding between the circuit traces and the active components in order to complete the circuit assembly (34). Also, a method for manufacturing a circuit assembly resistant to elevated temperature is disclosed.

Claims

1. In a combustion turbine engine, a circuit assembly for receiving sensed information about the condition of a turbine blade in the turbine engine and for transmitting said sensed information to a receiver external to said turbine engine, said circuit assembly comprising:

a printed circuit board affixed to the turbine blade and comprising an alumina substrate and having conductive traces formed of a thick film gold paste deposited thereon;

active and passive components of said circuit assembly being attached to said printed circuit board by means of gold, wherein at least one of said passive components comprises a metal wire air core conductor affixed to said circuit traces of said printed circuit board for forming an inductive element of said circuit assembly; and

,

gold wire bonding between said circuit traces and said active components in order to complete said circuit assembly, said gold wire bonding having a longitudinal axis being oriented parallel to a longitudinal axis of the turbine blade;

where said metal wire air core conductor comprises a coil of gold or silver wire covered along its length in an alumina-based potting material and exhibiting a quality factor Q of at least 5 at an operating temperature of the engine and an operating frequency of the circuit assembly.