Low temperature cofired ceramic packages for microwave and millimeter wave gallium arsenide integrated circuits

• US 4,899,118 A
• Filed: 12/27/1988
• Issued: 02/06/1990
• Est. Priority Date: 12/27/1988
• Status: Expired due to Fees

• Current Assignee: Hughes Electronics Corporation (Rtx Corporation)
• Original Assignee: Hughes Aircraft Company (Rtx Corporation)
• Inventors: Polinski, Paul W. Sr.
• Primary Examiner(s): Gensler, Paul
• Application Number:
  US07/289,862
• Time in Patent Office: 406 Days
• Field of Search: 333/238, 333/246, 333/247, 361/414
• US Class Current: 333/246
• CPC Class Codes: H01L 23/66 High-frequency adaptations
• 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 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H01L 2924/09701 Low temperature co-fired ceramic [LTCC]
• CPC Class Codes: H01L 2924/3011 Impedance
• CPC Class Codes: H01P 3/08 Microstrips; Strip lines
• CPC Class Codes: H05K 1/183 Components mounted in and supported by recessed areas of the printed circuit board

Abstract

A low temperature cofired monolithic ceramic package (10) for use with microwave and millimeter wave gallium arsenide integrated circuits, or the like. In situ buried passive components (28), including capacitors, resistors, couplers and inductors are incorporated within a cofired substrate structure (12). Fields of interconnected staggered or stacked vias (56, 58) are provided in the substrate below the integrated circuit for efficient heat transfer and electrical connection to a ground plane that eliminates complicated heat sink strucutres. At least one cavity (24) is provided in the top surface to confine integrated circuit chips. A plurality of connectable electrical conductors (34,36,38,40,42) including RF input and output leads and DC bias leads for the chip extend from the edge of the substrate (12) to the edge of the cavity (24). A sidewall 14 is extends around the periphery of the cavity (42) and comprises a low temperature cofired structure which is cofired with the substrate (12). The sidewall 14 has a metalized top surface and interconnected metalization and vias extending from the top surface to the top surface layer of the substrate (12). A cover (16) is provided which is attachable to the metalized top surface (44) of the sidewall (14). The electrical and thermal interconnections provided in the sidewall (14) and substrate (12) are provided by means of the plurality of interconnected staggered or stacked via interconnects. Electrical and thermal integrity is achieved which permits dissipation of heat by way of the ground plane and top cover, and electrial shielding is achieved by interconnecting the conductive components.

Claims

1. A monolithic microwave and millimeter wave hybrid microcircuit package comprising:

a substrate comprising;

(a) a metal ground plane;

(b) a low temperature cofired plurality of stacked ceramic layers disposed on the ground plane, each ceramic layer having a predetermined pattern of interconnect metallization disposed thereon and a plurality of metallized vias extending therethrough which interconnect to the interconnect metallization of adjacent cofired layers;

(c) a pattern of interconnect metallization and vias extending from the ground plane through the plurality of ceramic layers to a top surface layer thereof to provide thermal and electrical interconnection to the ground plane; and

(e) a cavity disposed in the top surface suitable for confining microwave and millimeter wave integrated circuit chips, such that a chip is connectable to the interconnect metallization;

a plurality of connectable electrical leads extending from the edge of the package substrate to the edge of the cavity;

a sidewall disposed on the top of the substrate and extending around the periphery of the cavity, and comprising a low temperature cofired plurality of ceramic layers which are cofired with the cofired ceramic layers of the substrate, the sidewall having a metallized top surface and having interconnected metallization and vias extending from the metallized top surface through the plurality of ceramic layers to the top surface layer of the substrate to provide electrical interconnection to selected interconnect metallization thereon; and

a metal cover attachable to the metallized top surface of the sidewall.

2. The monolithic microwave and millimeter wave ceramic hybrid microcircuit package of claim 1 wherein said substrate further comprises:

selected passive components disposed within the substrate; and

a pattern of interconnect metallization and vias extending from the top surface of the substrate to the selected passive components disposed within the substrate to provide for interconnection thereto.

3. The monolithic microwave and millimeter wave ceramic hybrid microcircuit package of claim 1 wherein said plurality of connectable electrical leads extending from an edge of the substrate to the edge of the cavity comprises:

a plurality of connectable electrical leads disposed on the top surface of the substrate and extending from the edge of the package substrate to the edge of the cavity; and

a plurality of connectable radio frequency input and output leads disposed on the top surface of the substrate and extending from the edge of the substrate to the edge of the cavity.

4. The monolithic microwave and millimeter wave ceramic hybrid microcircuit package of claim 1 wherein said plurality of connectable electrical leads extending from an edge of the substrate to the edge of the cavity comprises:

a plurality of connectable electrical leads disposed between selected cofired layers of the substrate and extending from the edge of the substrate to the edge of the cavity; and

a plurality of connectable radio frequency input and output leads disposed on the top surface of the substrate and extending from the edge of the substrate to the edge of the cavity.

5. The monolithic microwave and millimeter wave ceramic hybrid microcircuit package of claim 1 wherein said plurality of connectable electrical leads extending from an edge of the substrate to the edge of the cavity comprises:

a plurality of connectable electrical leads disposed between selected cofired layers of the substrate and extending from the edge of the substrate to the edge of the cavity; and

a plurality of connectable radio frequency input and output leads disposed between selected cofired layers of the substrate and extending from the edge of the substrate to the edge of the cavity.

6. The monolithic microwave and millimeter wave ceramic hybrid microcircuit package of claim 1 wherein said pattern of interconnect metalization comprises a pattern of staggered or stacked vias interconnected by interconnect metalization.

7. The monolithic microwave and millimeter wave ceramic hybrid microcircuit package of claim 1 which further comprises:

conductive metalization deposited on the external surface of the substrate and sidewall.

8. The monolithic microwave and millimeter wave ceramic hybrid microcircuit package of claim 7 wherein the conductive metalization is deposited by means of a predetermined coating process.

9. The monolithic microwave and millimeter wave ceramic hybrid microcircuit package of claim 7 wherein the coating process comprises a sputtering process.

10. The monolithic microwave and millimeter wave ceramic hybrid microcircuit package of claim 8 wherein the coating process comprises a vacuum deposition process.

11. A monolithic microwave and millimeter wave hybrid microcircuit package comprising:

a substrate comprising;

(a) a ground plane;

(b) a low temperature cofired plurality of stacked ceramic layers disposed on the ground plane, each ceramic layer having a predetermined pattern of interconnect metallization disposed thereon and a plurality of metallized vias extending therethrough which interconnect to the interconnect metallization of adjacent cofired layers, selected ones of the plurality of ceramic layers having selected passive components disposed thereon and interconnected to selected interconnect metallization;

(c) a pattern of interconnect metallization and vias extending from the ground plane through the plurality of ceramic layers to a top surface layer thereof to provide thermal and electrical interconnection to the ground plane;

(d) a pattern of interconnect metallization and vias extending from the top surface to the passive components disposed between the ceramic layers to provide for interconnection thereto; and

(e) at least one cavity disposed in the top surface suitable for confining microwave and millimeter wave integrated circuit chips, such that a chip is connectable to the interconnect metallization;

a plurality of connectable electrical leads extending from an edge of the substrate to the edge of the cavity;

a plurality of connectable radio frequency input and output leads extending from an edge of the substrate to the edge of the cavity;

a sidewall disposed on top of the package substrate and extending around the periphery of the cavity, and comprising low temperature cofired plurality of ceramic layers which are cofired with the cofired ceramic layers of the substrate, the sidewall having metallized top surface and having interconnected metallization and vias extending from the metallized top surface through the plurality of ceramic layers to the top surface layer of the substrate to provide electrical interconnection to selected interconnect metallization thereon; and

a cover attachable to the metallized top surface of the sidewall.

12. A monolithic microwave and millimeter wave hybrid microcircuit package comprising:

a low temperature cofired substrate made of a plurality of stacked layers having a metal ground plane and a predetermined number of passive components contained between selected layers of the substrate and having a plurality of interconnected vias extending from the top surface of the substrate to the ground plane to provide thermal and electrical interconnection thereto and a plurality of interconnected vias extending from the top surface of the substrate to each of the passive components for interconnection thereto;

at least one cavity formed in the top surface of the substrate;

bias interconnect metallization disposed on the top surface of the substrate and extending from the outside edge of the substrate to the edge of the cavity;

a plurality of radio frequency input and output conductor metallization disposed on the top surface of the substrate and extending from the outside edge of the substrate to the edge of the cavity;

a low temperature cofired sidewall disposed on the top surface of the substrate surrounding the cavity and having metallized top surface and plurality of interconnected vias interconnecting said top surface metallization to the ground plane;

conductive cover means attached and interconnected to the metallized top surface of the sidewall for enclosing the interior of the package.

13. A hybrid microcircuit package comprising:

a low temperature cofired layered substrate having buried passive components disposed between selected layers of the substrate and having a plurality of interconnected vias extending though the substrate to provide electrical interconnection to each of the buried passive components;

at least one cavity formed in the top surface of the substrate;

a plurality of conductor metallization paths disposed on selected surfaces of the substrate and extending from the outside edge of the substrate to the edge of the cavity;

a low temperature cofired sidewall disposed on the top surface of the substrate surrounding the cavity;

a cover attachable to the top surface of the sidewall for enclosing the package.

14. The hybrid microcircuit package of claim 13 wherein said sidewall further comprises:

a pattern of interconnect metalization and vias extending from the top surface to the substrate to provide for electrical interconnection thereto.

15. The hybrid microcircuit package of claim 13 wherein said plurality of connectable electrical leads comprise:

bias interconnect metalization disposed within the substrate and extending to the top surface of the substrate within the cavity and extending from the outside edge of the cavity to the edge of the substrate;

a plurality of connectable radio frequency input and output leads extending from an edge of the package substrate to the edge of the cavity.