Electromagnetically channelized microwave integrated circuit

• US 5,694,300 A
• Filed: 04/01/1996
• Issued: 12/02/1997
• Est. Priority Date: 04/01/1996
• Status: Expired due to Term

• Current Assignee: Northrop Grumman Systems Corporation (Northrop Grumman Corporation)
• Original Assignee: Northrop Grumman Corporation
• Inventors: Mattei, Carmelo J., Duthie, Joseph S.
• Primary Examiner(s): Picard, Leo P.
• Assistant Examiner(s): Vigushin, John B.
• Application Number:
  US08/626,305
• Time in Patent Office: 610 Days
• Field of Search: 174/35 R, 174/35 GC, 361/816, 361/818, 257/659, 257/660, 257/728, 257/790, 427/96, 427/98, 427/404, 427/99
• US Class Current: 361/818
• CPC Class Codes: H01L 2224/05599 Material
• CPC Class Codes: H01L 2224/32225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/45015 being circular
• CPC Class Codes: H01L 2224/45099 Material
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48227 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 2224/85399 Material
• CPC Class Codes: H01L 23/552 Protection against radiation, e.g. light or electromagnetic waves
• CPC Class Codes: H01L 23/66 High-frequency adaptations
• CPC Class Codes: H01L 24/48 of an individual wire connector
• CPC Class Codes: H01L 25/0655 the devices being arranged next to each other
• 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 2924/00012 Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• 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 2924/14 Integrated circuits
• CPC Class Codes: H01L 2924/1423 Monolithic Microwave Integrated Circuit [MMIC]
• CPC Class Codes: H01L 2924/15192 Resurf arrangement of the internal vias
• CPC Class Codes: H01L 2924/15311 being a ball array, e.g. BGA
• CPC Class Codes: H01L 2924/181 Encapsulation
• CPC Class Codes: H01L 2924/207 : Diameter ranges
• CPC Class Codes: H01L 2924/3011 : Impedance
• CPC Class Codes: H01L 2924/3025 : Electromagnetic shielding

Abstract

A multi-chip module (10) has a plurality of functional circuits each disposed within its own cavity (15-18), each cavity separated from the other by isolation channels (20, 21). Each functional circuit includes a plurality of monolithic microwave or high speed digital integrated circuit chips (29-33) which are wire bonded or flip-chip attached to the multi-chip module, and each is encapsulated in plastic (37) overmold compound. Complete electromagnetic shielding is provided by depositing metal (23) over the channels and the plastic encapsulation, thereby providing a totally electromagnetically channelized and shielded multi-circuit, microwave and/or high speed digital integrated circuit board.

Claims

1. An electromagnetically channelized multi-circuit, microwave or high speed digital integrated circuit array comprising:

a substrate board having a surface and electric contacts;

a plurality of separate functional circuits, each comprising a plurality of monolithic microwave or digital integrated circuit chips disposed above said surface and electrically interconnected with each other and with said contacts;

a layer of plastic encapsulation material above said surface, said layer arranged in a plurality of distinct sections, each of said sections separated from the others of said sections, each of said sections corresponding to one of said functional circuits, each of said sections completely encapsulating the corresponding one of said functional circuits, said sections being disposed inwardly from the edges of said board; and

a layer of metal on the order of several hundred Angstroms to several hundred thousand Angstroms thick disposed over said surface and said plastic encapsulation material which encloses each of said functional circuits in a metalized cavity and provides a metalized channel surrounding each of said functional circuits.

2. An array according to claim 1 wherein the thickness of said layer of metal is on the order of several hundred Angstroms to several thousand Angstroms.

3. A method of making an electromagnetically channelized multi-circuit, microwave or high speed digital integrated circuit array comprising:

providing a substrate board having a surface and electric contacts;

mounting a plurality of separate functional circuits, each comprising a plurality of monolithic microwave integrated circuit chips disposed above said surface;

electrically interconnecting said circuit chips with each other and with said contacts;

depositing a layer of plastic encapsulation material above said surface in a plurality of distinct sections, each of said sections separated from the others of said sections, each of said sections corresponding to one of said functional circuits, each of said sections completely encapsulating the corresponding one of said functional circuits, said sections being disposed inwardly from the edges of said board; and

depositing a layer of metal over said surface and over said plastic encapsulating material thereby to enclose each of said functional circuits in a metal cavity and provide a metalized channel surrounding each of said functional circuits.

4. A method according to claim 3 wherein said last depositing step comprises depositing a layer of metal on the order of several hundred Angstroms thick or greater over said surface and over said plastic encapsulation material.

5. An electromagnetically channelized multi-circuit, microwave or high speed digital integrated circuit array comprising:

a substrate board having a surface and electric contacts;

a plurality of separate functional circuits, each comprising a plurality of monolithic microwave or digital integrated circuit chips disposed above said surface and electrically interconnected with each other and with said contacts;

a layer of plastic encapsulation material above said surface, said layer arranged in a plurality of distinct sections, each of said sections separated from the others of said sections, each of said sections corresponding to one of said functional circuits, each of said sections completely encapsulating the corresponding one of said functional circuits, said sections being disposed inwardly from the edges of said board; and

a single deposited layer of metal on the order of several hundred Angstroms thick or greater disposed over said surface and said plastic encapsulation material which both completely encloses each of said functional circuits in a totally metalized cavity and provides a unitary, completely metalized channel which surrounds each of said functional circuits.

6. An array according to claim 5 wherein the thickness of said layer of metal is on the order of several hundred Angstroms to several thousand Angstroms.