US5151388A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Flip interconnect
Assignee: Raytheon Co
•
Filing: 1991-05-07
•
Granted: 1992-09-29
•
Expires: 2011-05-07
Abstract
Abstract Interconnection of densely populated multiple chip integrated hybrid circuits (12) in a manner such that heat can be efficiently extracted therefrom. An integrated circuit die (31) is attached to a flip chip interconnect layer by soldering the connection pads thereto. The interconnect layer is slid off its substrate (11) in the manner of a decal. After the circuit has been tested and found acceptable, the other side of the die (31) is permanently bonded to a thermal conduction plate or heat sink (32). The decal interconnect (33) is made of alternating layers of an insulator (41) and a conductor (42) built on top of an erodible sacrifical layer (48) applied to a substrate. The sacrificial layer (48) is dissolved by a suitable solvent to float the multilayer interconnect off the substrate (11).
Inventors
- 👤 Gabriel G. Bakhit
- 👤 Kevin P. Shambrook
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 00:11
CPC Classifications
H; H10; H10P; H10P72/00; H10P72/70; H10P72/74; H10P72/7424; H10P72/743; H10W; H10W72/00; H10W72/071; H10W72/072; H10W72/07231; H10W72/07236; H10W90/00; H10W90/701; H10W90/751; H10W90/754; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49004; Y10T29/49117; Y10T29/49124; Y10T29/49128
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
122 words
A method of packaging a plurality of densely disposed integrated circuit chips comprising the following steps: applying the connection pads of a plurality of integrated circuit chips to a decal-like multilayer interconnect, said multilayer interconnect comprising alternate layers of insulator and metal formed on a substrate and separated from said substrate by a sacrificial layer; applying heat to said integrated circuit chips and to said interconnect to form an electrical connection therebetween; pretesting electrically the performance of said integrated circuit chips; dissolving said sacrificial layer with a suitable solvent; floating the decal-like multilayer interconnect off said substrate; bonding a heat sink to said integrated circuit chips on the side opposite the face thereof; and packaging said integrated circuit chips in a container.
Claim 2
Independent Claim
122 words
A method of packaging a plurality of densely disposed integrated circuit chips comprising the following steps: applying the connection pads of a plurality of integrated circuit chips to a decal-like multilayer interconnect, said multilayer interconnect comprising alternate layers of insulator and metal formed on a substrate and separated from said substrate by a sacrificial layer; applying heat to said integrated circuit chips and to said interconnect to form an electrical connection therebetween; pretesting electrically the performance of said integrated circuit chips; dissolving said sacrificial layer with a suitable solvent; floating the decal-like multilayer interconnect off said substrate; bonding a heat sink to said integrated circuit chips on the side opposite the face thereof; and packaging said integrated circuit chips in a container.
Claim 3
Independent Claim
117 words
A method of interconnecting a plurality of densely disposed integrated circuit chips comprising the following steps: applying a sacrificial layer of an erodible substance to a substrate; building a multilayer decal-like flexible interconnect of alternating layers of conductor and insulator on said substrate; dissolving said sacrificial layer with a suitable solvent; floating said flexible interconnect off said substrate; applying the connection pads of a plurality of integrated circuit chips to said flexible interconnect; soldering the connection pads of said integrated circuit chips to said flexible interconnect to form electrical connection therebetween; pretesting electrically the performance of said integrated circuit chips; and bonding a heat sink to said integrated circuit chips on the side opposite the face thereof.
Claim 4
Independent Claim
117 words
A method of interconnecting a plurality of densely disposed integrated circuit chips comprising the following steps: applying a sacrificial layer of an erodible substance to a substrate; building a multilayer decal-like flexible interconnect of alternating layers of conductor and insulator on said substrate; dissolving said sacrificial layer with a suitable solvent; floating said flexible interconnect off said substrate; applying the connection pads of a plurality of integrated circuit chips to said flexible interconnect; soldering the connection pads of said integrated circuit chips to said flexible interconnect to form electrical connection therebetween; pretesting electrically the performance of said integrated circuit chips; and bonding a heat sink to said integrated circuit chips on the side opposite the face thereof.
Claim 5
Independent Claim
56 words
A method of making a decal-like flexible interconnect comprising the following steps: applying a sacrificial layer of an erodible substance to a substrate; building a multilayer interconnect of alternating insulating and conductive layers on top of said sacrificial layer; dissolving said sacrificial layer with a suitable solvent; and floating said decal-like flexible interconnect off said substrate.
Claim 6
Independent Claim
56 words
A method of making a decal-like flexible interconnect comprising the following steps: applying a sacrificial layer of an erodible substance to a substrate; building a multilayer interconnect of alternating insulating and conductive layers on top of said sacrificial layer; dissolving said sacrificial layer with a suitable solvent; and floating said decal-like flexible interconnect off said substrate.
Claim 7
Dependent Claim
21 words
The method of claim 3 in which said sacrificial layer comprises titanium and said solvent comprises a 30% hydrogen peroxide mixture.
Claim 8
Dependent Claim
21 words
The method of claim 3 in which said sacrificial layer comprises tungsten and said solvent comprises a 30% hydrogen peroxide mixture.
Claim 9
Dependent Claim
28 words
The method of claim 3 in which said sacrificial layer comprises an organic thermoplastic which is heated so that the flexible interconnect may be peeled off the substrate.
Claim 10
Dependent Claim
14 words
The method of claim 3 in which said sacrificial layer comprises an organic material.
Claim 11
Dependent Claim
19 words
The method of claim 3 in which said sacrificial layer comprises silicon oxide and the solvent comprises hydrofluoric acid.
Claim 12
Dependent Claim
18 words
The method of claim 3 in which said sacrificial layer comprises sodium carbonate and said solvent comprises water.
Claim 13
Dependent Claim
11 words
The method of claim 3 in which said substrate comprises silicon.
Claim 14
Dependent Claim
11 words
The method of claim 3 in which said substrate comprises ceramic.
Claim 15
Dependent Claim
12 words
The method of claim 3 in which said insulating layer comprises polyimide.
Claim 16
Dependent Claim
12 words
The method of claim 3 in which said conductive layer comprises aluminum.
Claim 17
Dependent Claim
12 words
The method of claim 3 in which said conductive layer comprises copper.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-09-29 | 1996-03-30 | 1996-09-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-09-29 | 2000-03-30 | 2000-09-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-09-29 | 2004-03-30 | 2004-09-29 | $7700.00 | Window Closed / Lapsed |