US5468994A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High pin count package for semiconductor device
Assignee: HP Inc
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Filing: 1992-12-10
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Granted: 1995-11-21
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Expires: 2012-12-10
Abstract
Abstract A thermally and electrically enhanced surface mount package with up to at least 600 I/O connections, but possessing the flexibility and simplicity of conventional leadframes. The package includes an integrated circuit die having a plurality of bonding pads, a conductive substrate having a cavity formed therein for receiving the integrated circuit die, and a flexible circuit laminated on the conductive substrate. The flexible circuit includes at least a wiring pattern and an area array of bumps formed on pads at the periphery of the flexible circuit. The flexible circuit may include a plurality of openings through the flexible circuit beneath certain of the pads or traces of the wiring pattern so as to ground the certain of the pads (ground pads) or traces to the conductive substrate. Preferably, the lamination of the flexible circuit to the conductive substrate would be performed using a conductive adhesive which substantially fills the openings to facilitate the concomitant electrical connection of the ground pads to the conductive substrate. The package is advantageous because it provides excellent thermal performance and controlled impedance signal transmission which are important in packages having a high number of I/O connections, yet it is relatively inexpensive to produce, has a generic finger layout like leadframes, and lends itself to surface mount assembly by conventional pick-and-place and mass reflow techniques. A method for making the package is also disclosed.
Inventors
- 👤 Rajendra D. Pendse
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 04:59
CPC Classifications
H; H10; H10W; H10W70/00; H10W70/60; H10W70/62; H10W70/65; H10W70/67; H10W70/68; H10W90/00; H10W90/701; H10W70/654; H10W70/655; H10W70/682; H10W72/00; H10W72/071; H10W72/075; H10W72/07531; H10W72/07532; H10W72/07533; H10W72/07551; H10W72/07554; H10W72/50; H10W72/531; H10W72/536; H10W72/5363; H10W72/5366; H10W72/541; H10W72/547; H10W72/551; H10W72/552; H10W72/5522; H10W72/59; H10W72/851; H10W72/874; H10W72/884; H10W72/90; H10W72/951; H10W72/952; H10W74/00; H10W90/731; H10W90/734; H10W90/736; H10W90/751; H10W90/754
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
159 words
A metal leadless integrated circuit package comprising: a metal body; an integrated circuit die thermally coupled to said metal body; a flexible circuit laminated on said metal body, said flexible circuit including at least a dielectric layer, a wiring formed on said dielectric layer and operatively connected to said integrated circuit die, and at least one opening through at least said dielectric layer of said flexible circuit for electrically connecting a portion of said wiring layer to said metal body; wherein said wiring layer includes wiring traces and a plurality of pads, and said flexible circuit has a plurality of openings through at least said dielectric layer beneath said pads or said traces, wherein said metal body includes at least a cavity formed therein for receiving said integrated circuit, and a wire-bondable finish on at least a region surrounding the cavity, and wherein said integrated circuit includes at least ground bonding pads which are down-bonded to said wire-bondable finish.
Claim 2
Dependent Claim
159 words
A metal leadless integrated circuit package comprising: a metal body; an integrated circuit die thermally coupled to said metal body; a flexible circuit laminated on said metal body, said flexible circuit including at least a dielectric layer, a wiring formed on said dielectric layer and operatively connected to said integrated circuit die, and at least one opening through at least said dielectric layer of said flexible circuit for electrically connecting a portion of said wiring layer to said metal body; wherein said wiring layer includes wiring traces and a plurality of pads, and said flexible circuit has a plurality of openings through at least said dielectric layer beneath said pads or said traces, wherein said metal body includes at least a cavity formed therein for receiving said integrated circuit, and a wire-bondable finish on at least a region surrounding the cavity, and wherein said integrated circuit includes at least ground bonding pads which are down-bonded to said wire-bondable finish.
Claim 3
Dependent Claim
199 words
A metal leadless integrated circuit package, comprising: an integrated circuit die having a plurality of bonding pads; a metal body thermally coupled to said integrated circuit die; and a flexible circuit laminated on said metal body, said flexible circuit including at least a dielectric layer, a wiring pattern formed on said dielectric layer and operatively connected to said integrated die and an area array of pads formed at the periphery of said flexible circuit, said wiring pattern electrically connecting a plurality of the bonding pads of said integrated circuit die to said area array of pads, at least one opening through said dielectric layer of said flexible circuit for electrically connecting a portion of said wiring pattern to said metal body, wherein said wiring layer includes wire traces and a plurality of pads, and said flexible circuit has a plurality of openings through at least said dielectric layer beneath said pads or said traces, wherein said metal body includes at least a cavity formed for receiving said integrated circuit, and a wire-bondable finish on at least a region surrounding the cavity, and wherein said integrated circuit includes at least ground bonding pads which are down-bonded to said wire-bondable finish.
Claim 4
Dependent Claim
199 words
A metal leadless integrated circuit package, comprising: an integrated circuit die having a plurality of bonding pads; a metal body thermally coupled to said integrated circuit die; and a flexible circuit laminated on said metal body, said flexible circuit including at least a dielectric layer, a wiring pattern formed on said dielectric layer and operatively connected to said integrated die and an area array of pads formed at the periphery of said flexible circuit, said wiring pattern electrically connecting a plurality of the bonding pads of said integrated circuit die to said area array of pads, at least one opening through said dielectric layer of said flexible circuit for electrically connecting a portion of said wiring pattern to said metal body, wherein said wiring layer includes wire traces and a plurality of pads, and said flexible circuit has a plurality of openings through at least said dielectric layer beneath said pads or said traces, wherein said metal body includes at least a cavity formed for receiving said integrated circuit, and a wire-bondable finish on at least a region surrounding the cavity, and wherein said integrated circuit includes at least ground bonding pads which are down-bonded to said wire-bondable finish.
Claim 5
Dependent Claim
25 words
A metal leadless integrated circuit package as recited in claim 2, wherein said flexible circuit is attached on said metal body using a conductive adhesive.
Claim 6
Dependent Claim
49 words
A metal leadless integrated circuit package as recited in claim 2, wherein said integrated circuit package further comprises an encapsulation layer covering at least said integrated circuit die, said encapsulation layer further functions as a stand-off when said integrated circuit package is mounted to a main printed circuit board.
Claim 7
Dependent Claim
205 words
An integrated circuit package, comprising: an integrated circuit die having a plurality of bonding pads; a metal body having a cavity formed therein for receiving said integrated circuit die, said integrated circuit die being thermally coupled to said metal body; a flexible circuit laminated on said metal body, said flexible circuit including at least a dielectric layer, an area array of outer pads formed on said dielectric layer at the periphery of said flexible circuit, the outer pads including signal pads and ground pads, wherein said metal body includes a wire-bondable finish on at least a region surrounding the cavity, wherein said integrated circuit includes at least said ground pads which are down-bonded to said wire-bondable finish, a wiring pattern formed on said dielectric and operatively connected to said integrated circuit die, said wiring pattern electrically connecting a plurality of the bonding pads of said integrated circuit die to the signal pads of said area array of outer pads, and a plurality of openings through at least said dielectric layer of said flexible circuit beneath the ground pads, whereby the ground pads are electrically connected to said metal body; and solder bumps formed on the outer pads of said area array of said flexible circuit.
Claim 8
Dependent Claim
205 words
An integrated circuit package, comprising: an integrated circuit die having a plurality of bonding pads; a metal body having a cavity formed therein for receiving said integrated circuit die, said integrated circuit die being thermally coupled to said metal body; a flexible circuit laminated on said metal body, said flexible circuit including at least a dielectric layer, an area array of outer pads formed on said dielectric layer at the periphery of said flexible circuit, the outer pads including signal pads and ground pads, wherein said metal body includes a wire-bondable finish on at least a region surrounding the cavity, wherein said integrated circuit includes at least said ground pads which are down-bonded to said wire-bondable finish, a wiring pattern formed on said dielectric and operatively connected to said integrated circuit die, said wiring pattern electrically connecting a plurality of the bonding pads of said integrated circuit die to the signal pads of said area array of outer pads, and a plurality of openings through at least said dielectric layer of said flexible circuit beneath the ground pads, whereby the ground pads are electrically connected to said metal body; and solder bumps formed on the outer pads of said area array of said flexible circuit.
Claim 9
Dependent Claim
18 words
An integrated circuit package as recited in claim 5, wherein said metal body functions as a ground plane.
Claim 10
Dependent Claim
49 words
An integrated circuit package as recited in claim 6, wherein said flexible circuit 10, wherein said flexible circuit is laminated on said metal body using a conductive adhesive, and wherein said openings are substantially filled with the conductive adhesive to electrically connect the ground pads to said metal body.
Claim 11
Dependent Claim
47 words
An integrated circuit package as recited in claim 5, wherein said integrated circuit package further comprises an encapsulation layer covering at least said integrated circuit die, said encapsulation layer further functions as a stand-off when said integrated circuit package is mounted to a main printed circuit board.
Claim 12
Dependent Claim
190 words
A metal leadless integrated circuit package, comprising: an integrated circuit die having a plurality of bonding pads; a metal body thermally coupled to said integrated circuit die; a flexible circuit laminated on said metal body, said flexible circuit including at least a dielectric layer, a wiring pattern formed on said dielectric layer and operatively connected to said integrated die and an area array of pads formed at the periphery' of said flexible circuit, said wiring pattern electrically connecting a plurality of the bonding pads of said integrated circuit die to said area array of pads, at least one opening through said dielectric layer of said flexible circuit for electrically connecting a portion of said wiring pattern to said metal body, wherein said wiring layer includes wire traces and a plurality of pads, and said flexible circuit has a plurality of openings through at least said dielectric layer beneath said pads or said traces; and a ground bar formed at the inner periphery of said flexible circuit, and wherein at least one of the bonding pads of said integrated circuit die are wire-bonded to said ground bar of said flexible circuit.
Claim 13
Dependent Claim
190 words
A metal leadless integrated circuit package, comprising: an integrated circuit die having a plurality of bonding pads; a metal body thermally coupled to said integrated circuit die; a flexible circuit laminated on said metal body, said flexible circuit including at least a dielectric layer, a wiring pattern formed on said dielectric layer and operatively connected to said integrated die and an area array of pads formed at the periphery' of said flexible circuit, said wiring pattern electrically connecting a plurality of the bonding pads of said integrated circuit die to said area array of pads, at least one opening through said dielectric layer of said flexible circuit for electrically connecting a portion of said wiring pattern to said metal body, wherein said wiring layer includes wire traces and a plurality of pads, and said flexible circuit has a plurality of openings through at least said dielectric layer beneath said pads or said traces; and a ground bar formed at the inner periphery of said flexible circuit, and wherein at least one of the bonding pads of said integrated circuit die are wire-bonded to said ground bar of said flexible circuit.
Claim 14
Dependent Claim
25 words
A metal leadless integrated circuit package as recited in claim 9, wherein said flexible circuit is attached on said conductive substrate using a conductive adhesive.
Claim 15
Dependent Claim
49 words
A metal leadless integrated circuit package as recited in claim 9, wherein said integrated circuit package further comprises an encapsulation layer covering at least said integrated circuit die, said encapsulation layer further functions as a standoff when said integrated circuit package is mounted to a main printed circuit board.
Claim 16
Dependent Claim
207 words
An integrated circuit package, comprising: an integrated circuit die having a plurality of bonding pads; a metal body having a cavity formed therein for receiving said integrated circuit die, said integrated circuit die being thermally coupled to said metal body; a flexible circuit laminated on said metal body, said flexible circuit including at least a dielectric layer, an area array of outer pads formed on said dielectric layer at the periphery of said flexible circuit, the outer pads including signal pads and ground pads, a wiring pattern formed on said dielectric and operatively connected to said integrated circuit die, said wiring pattern electrically connecting a plurality of bonding pads of said integrated circuit die to the signal pads of said area array of outer pads, and a plurality of opening through at least said dielectric layer of said flexible circuit beneath the ground pads, whereby the ground pads are electrically connected to said metal body; a ground bar formed at the inner periphery of said flexible circuit, and wherein at least one of the bonding pads of said integrated circuit die are wire-bonded to said ground bar of said flexible circuit; and solder bumps formed on the outer pads of said area array of said flexible circuit.
Claim 17
Dependent Claim
207 words
An integrated circuit package, comprising: an integrated circuit die having a plurality of bonding pads; a metal body having a cavity formed therein for receiving said integrated circuit die, said integrated circuit die being thermally coupled to said metal body; a flexible circuit laminated on said metal body, said flexible circuit including at least a dielectric layer, an area array of outer pads formed on said dielectric layer at the periphery of said flexible circuit, the outer pads including signal pads and ground pads, a wiring pattern formed on said dielectric and operatively connected to said integrated circuit die, said wiring pattern electrically connecting a plurality of bonding pads of said integrated circuit die to the signal pads of said area array of outer pads, and a plurality of opening through at least said dielectric layer of said flexible circuit beneath the ground pads, whereby the ground pads are electrically connected to said metal body; a ground bar formed at the inner periphery of said flexible circuit, and wherein at least one of the bonding pads of said integrated circuit die are wire-bonded to said ground bar of said flexible circuit; and solder bumps formed on the outer pads of said area array of said flexible circuit.
References Cited (Backward Citations)
US4910582A
Cited
US4881116A
Cited
US4949158A
Cited
US5016084A
Cited
US5087530A
Cited
US5080980A
Cited
US5237202A
Cited
US5045921A
Cited
US5148265A
Cited
US5148266A
Cited
US5120678A
Cited
US5138430A
Cited
US5162975A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-11-20 | 1999-05-22 | 1999-11-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-11-20 | 2003-05-22 | 2003-11-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-11-20 | 2007-05-22 | 2007-11-21 | $7700.00 | Window Closed / Lapsed |