Acoustical array with multilayer substrate integrated circuits

• US 6,589,180 B2
• Filed: 03/08/2002
• Issued: 07/08/2003
• Est. Priority Date: 06/20/2001
• Status: Expired due to Term

• Current Assignee: Mind Fusion, LLC (Ascend Innovation Management, LLC)
• Original Assignee: BAE Systems Information and Electronic Systems Integration Incorporated (BAE Systems Plc)
• Inventors: Marciniec, John, Erikson, Kenneth R., White, Timothy E.
• Primary Examiner(s): Lateef, Marvin M.
• Assistant Examiner(s): Imam, Ali M.
• Application Number:
  US10/094,851
• Publication Number:
  US 20030013969A1
• Time in Patent Office: 487 Days
• Field of Search: 600/407-471, 367/7, 367/11, 367/130, 367/138, 310/334, 29/253.5, 736/25, 736/26
• US Class Current: 600/459
• CPC Class Codes: A61B 8/0833 involving detecting or locating foreign bodies or organic structures
• CPC Class Codes: A61B 8/4483 characterised by features of the ultrasound transducer
• CPC Class Codes: B06B 1/0622 on one surface
• CPC Class Codes: B06B 1/0629 Square array
• CPC Class Codes: G01S 15/8915 using a transducer array
• CPC Class Codes: G01S 7/52023 Details of receivers
• CPC Class Codes: G01S 7/52049 using correction of medium-induced phase aberration
• CPC Class Codes: G01S 7/52079 Constructional features constructional features of transducers B06B; mounting transducers G10K11/00; constructional features of ultrasonic medical diagnostic devices A61B8/44
• CPC Class Codes: G01S 7/5208 with integration of processing functions inside probe or scanhead
• CPC Class Codes: H01L 2224/05568 the whole external layer protruding from the surface
• CPC Class Codes: H01L 2224/0557 the external layer being disposed on a via connection of the semiconductor or solid-state body
• CPC Class Codes: H01L 2224/05573 Single external layer
• CPC Class Codes: H01L 2224/16225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2924/15311 being a ball array, e.g. BGA
• CPC Class Codes: H10N 39/00 Integrated devices, or assemblies of multiple devices, comprising at least one piezoelectric, electrostrictive or magnetostrictive element covered by groups H10N30/00 – H10N35/00
• CPC Class Codes: Y10T 29/42 Piezoelectric device making

Abstract

A high density, exceptionally complex and compact ultrasound transducer array using multi-layer structures composed of active integrated circuit devices on various substrates and passive devices. Electrically conducting interconnections between substrates are implemented with micro-vias configured with conductors extending through the substrates, permitting the use of divided or different integrated circuit technologies arranged and/or isolated within different integrated circuit substrates or layers of the ultrasound transducer assembly. The various layers may be assembled with solders of respectively lower reflow temperatures, to permit testing of selected layers and circuits prior to completion.

Claims

1. A multilayer acoustical transducer array assembly for an ultrasound system comprising

a multi-element acoustical transducer array with a front side for emitting and receiving acoustical energy, a backside and a backside pattern of electrical contacts,

a first substrate with associated electronic circuitry for operating the array, said first substrate having a first side with matching electrical contacts for contacting said backside of said transducer array and a second side with second side electrical circuit contacts, said transducer array being aligned with said first substrate, said electrical contacts of said transducer array being electrically bonded to respective said electrical contacts on said first side of said first substrate, and

a final substrate with additional associated electronic circuitry for operating the array, said final substrate having at least a first side with matching electrical contacts, said substrates being configured as successive layers from said first substrate to said final substrate, said second side electrical contacts being electrically bonded to respective said matching electrical contacts on adjacent said substrates.

2. A multilayer acoustical transducer array assembly according to claim 1, wherein said first substrate is a semiconductor integrated circuit.

3. A multilayer acoustical transducer array assembly according to claim 2, said first semiconductor integrated circuit comprising at least high voltage switches for operating said multi-element acoustical transducer array as a transmitter such that acoustical energy is emitted from said front side of said acoustical transducer array.

4. A multilayer acoustical transducer array assembly according to claim 2, said semiconductor integrated circuit comprising at least switching circuitry for switching said array between emitting and receiving modes of operation.

5. A multilayer acoustical transducer array assembly according to claim 1, wherein said first and said final substrates are semiconductor integrated circuits.

6. A multilayer acoustical transducer array assembly according to claim 5, wherein said first semiconductor integrated circuit is comprised of at least high voltage switches for operating said multi-element acoustical transducer array as a transmitter such that acoustical energy is emitted from said front side of said acoustical transducer array and said final semiconductor integrated circuit is comprised of at least high density, low voltage electronics for operating said multi-element acoustical transducer array to receive and further process acoustical signals received by said acoustical transducer array.

7. A multilayer acoustical transducer array assembly according to claim 1, wherein said multi-element acoustical transducer array, said first substrate and said final substrate are aligned in a co-planar configuration.

8. A multilayer acoustical transducer array assembly according to claim 1, further comprising at least one intermediate substrate with further associated integrated circuitry for operating the array, said intermediate substrate having a first side with matching electrical contacts and a second side with second side electrical contacts, said intermediate substrate disposed between said first substrate and said final substrate.

9. A multilayer acoustical transducer array assembly according to claim 8, wherein at least one said intermediate integrated circuit substrate has image processing capability.

10. A multilayer acoustical transducer array assembly according to claim 1, further comprising an acoustically attenuating layer with a backside, and a front side adhered to said backside of said final substrate.

11. A multi-layer acoustical transducer array assembly according to claim 10, further comprising a planar display array electrically connected to at least one of said substrates.

12. A multi-layer acoustical transducer array assembly according to claim 11, said planar display attached to the backside of said acoustically attenuating layer.

13. A multilayer acoustical transducer array assembly according to claim 1, wherein at least one said substrate has electrical paths connecting one or more parts of said electronics circuitry on said first side to respective selected electrical contacts on said second side.

14. A multilayer acoustical array assembly according to claim 13, said electrical paths comprising vias extending through said substrate, said vias comprising electrically conductive materials.

15. A multilayer acoustical array assembly according to claim 1, said first substrate further comprising electronic circuitry for selecting between groups of transducers within said transducer array.

16. A multilayer acoustical transducer array assembly according to claim 15, said groups of transducers comprising orthogonally oriented lines of transducers within said transducer array.

17. A multilayer acoustical transducer array assembly according to claim 1, said electrical bonding being composed of solder bumps.

18. A multilayer acoustical transducer array assembly according to claim 17, wherein said solder bumps between said acoustical transducer array and said first substrate are composed of a lower melting temperature material than said solder bumps between said second side of said first substrate and said first side electrical contacts of said final substrate.

19. A multilayer acoustical transducer array assembly according to claim 1, said electronic circuitry of said first substrate comprising at least circuitry for switching said multi-element transducer array between emitting and receiving modes of operation, said electronic circuitry in said final substrate comprising at least receiving circuitry for receiving signals from said array.

20. A multilayer acoustical transducer array assembly for an ultrasound imaging system comprising

a multi-element acoustical transducer array with a front side for emitting and receiving acoustical signals and a backside and backside pattern of electrical contacts,

a first substrate with electronic circuitry for operating the array, said first substrate having a first side with matching electrical contacts for contacting said transducer array for operation and a second side with second side electrical circuit contacts, said transducer array being aligned in a co-planar configuration with said first substrate, said electrical contacts of said transducer array being electrically bonded to respective said electrical contacts on said first side of said first substrate, and

at least one intermediate substrate with further associated electronic circuitry for operating the array, said intermediate integrated circuit substrate having a first side with matching electrical contacts and a second side with second side electrical contacts,

a final integrated circuit substrate with additional said associated electronic circuitry for operating the array, said final substrate having a first side with matching electrical contacts and a second side, all said substrates being aligned in a co-planar configuration, said second side electrical contacts of each said substrate being electrically bonded to respective said matching electrical contacts on each adjacent said substrate, and

an acoustical backing layer adhered to said second side of said final substrate, said first substrate having electrical paths connecting at least selected said electrical contacts on said first side to respective selected electrical contacts on said second side, said electrical paths comprising vias extending through said substrate, said vias comprising electrically conductive materials.

21. A multilayer acoustical array assembly according to claim 20, said first integrated circuit substrate further comprising circuitry for selecting between groups of transducers within said transducer array.

22. A multilayer acoustical transducer array assembly according to claim 21, said groups of transducers comprising orthogonally oriented lines of transducers within said transducer array.

23. A multilayer acoustical transducer array assembly according to claim 20, said electrical bonding being composed of solder bumps.

24. A multilayer acoustical transducer array assembly according to claim 23, said solder bumps bonding said backside pattern of said multi-element transducer array to said first side contacts of said first substrate being composed of a metal alloy with melting temperature T1, and

said solder bumps bonding said second side pattern of said first substrate to said first side contacts of said intermediate substrate being composed of a metal alloy with melting temperature T2, and

said solder bumps bonding said second side pattern of said intermediate substrate to said first side contacts of said final substrate being composed of a metal alloy with melting temperature T3, where T1 is less than T2, and T2 is less than T3.

25. A multilayer acoustical transducer array assembly according to claim 20, said electrical bonding being composed of an electrically conductive polymer.

26. A multilayer acoustical transducer array assembly according to claim 20, said associated integrated circuitry in said intermediate integrated circuit substrate comprising at least switching circuitry for switching said array between transmitting and receiving modes of operation.

27. A multilayer acoustical transducer array assembly according to claim 20, said associated integrated circuitry in said final integrated circuit substrate comprising at least receiving circuitry for receiving signals from said array.

28. A multilayer acoustical transducer array assembly comprising

a multi-element acoustical transducer array with a front side for transmitting and receiving acoustical energy, a backside and backside pattern of electrical contacts,

a first integrated circuit substrate with associated electronic circuitry for operating the array, said first substrate having a first side with matching electrical connections to said transducer array for conducting electrical signals between said transducer array and said first integrated circuit and a second side with second side electrical circuit contacts,

a final integrated circuit substrate with additional associated electronic circuitry for operating the array, said final integrated circuit substrate having at least a first side with matching electrical contacts, said substrates being configured as successive layers from said first integrated circuit substrate to said final integrated circuit substrate, said second side electrical contacts being electrically bonded to respective said matching electrical contacts on adjacent said substrates,

with said acoustical transducer array and all said substrates being aligned in a convex, concave or co-planar configuration, said second side electrical contacts of each said integrated circuit substrate being electrically bonded to respective said matching electrical contacts on each adjacent said integrated circuit substrate with solder bumps, and

an acoustical backing layer adhered to said second side of said final integrated circuit substrate, said first integrated circuit substrate having electrical paths connecting at least selected said electrical contacts on said first side to respective selected electrical contacts on said second side, said electrical paths comprising vias extending through said integrated circuit substrate, said vias comprising electrically conductive materials, said associated integrated circuitry in said first integrated circuit substrate comprising at least switching circuitry for switching said array between transmitting and receiving modes of operation, said associated integrated circuitry in said final integrated circuit substrate comprising at least receiving circuitry for receiving signals from said array.

29. A multilayer acoustical transducer array assembly according to claim 28, said solder bumps between said final integrated circuit substrate and said first integrated circuit substrate being composed of a material with a higher reflow melting temperature than said solder bumps between said first integrated circuit substrate and said acoustical transducer array.

30. A method for making a multilayer acoustical transducer array assembly comprising the steps:

providing

an acoustical transducer array with a backside pattern of electrical contacts,

a first integrated circuit substrate with a first side with matching electrical contacts to said backside pattern of electrical contacts of said acoustical transducer array and a second side with a second side pattern of electrical contacts, said first integrated circuit substrate comprising associated integrated electronic circuitry for supporting the operation of said array and electrical paths connecting selected said matching electrical contacts on said first side thereof to respective selected electrical contacts on said second side thereof, said electrical paths comprising vias extending through said integrated circuit substrate, said vias comprising electrically conductive materials, and

a second integrated circuit substrate having at least a first side of matching electrical contacts and comprising integrated electronic circuitry for supporting the operation of said array, and

electrically bonding said matching electrical contacts on said first side of said second integrated circuit substrate to said electrical contacts on said second side of said first integrated circuit substrate at a first temperature, and

electrically bonding the matching electrical contacts on the first side of said first integrated circuit substrate to said electrical contacts of said array at a second temperature,

said second temperature being lower than said first temperature.

31. A method for making a multilayer acoustical transducer array assembly according to claim 30, comprising the additional step, prior to the step of electrically bonding the matching electrical contacts on the first side of said first integrated circuit substrate to said electrical contacts of said array, of

testing at least selected electrical functions of said second integrated circuit substrate at least in part through access to the electrical contacts on the first side of said first integrated circuit substrate.

32. A method for making a multilayer acoustical transducer array assembly according to claim 30, comprising the further steps:

providing said second integrated circuit substrate with a second side with electrical contacts and electrical paths connecting selected said matching electrical contacts on said first side thereof to respective selected electrical contacts on said second side thereof, said electrical paths comprising vias extending through said integrated circuit substrate, said vias comprising electrically conductive materials, and

providing a third integrated circuit substrate comprising additional integrated circuitry for supporting the operation of said array and having at least a first side of matching electrical contacts, and prior to electrically bonding said first substrate to said second substrate,

electrically bonding the matching electrical contacts on the first side of said third integrated circuit substrate to the electrical contacts on said second side of said second integrated circuit substrate at a third temperature, said third temperature being higher than said second temperature.

33. A method for making a multilayer acoustical transducer array assembly according to claim 32, comprising the additional step, prior to the step of electrically bonding the matching electrical contacts on the first side of said first integrated circuit substrate to said electrical contacts of said array, of

testing at least selected electrical functions of said third integrated circuit substrate at least in part through access to the electrical contacts on the first side of said second integrated circuit substrate.