US6294100B1
Expired / Lapsed
US
⏱️ 0.0 years remaining
Exposed die leadless plastic chip carrier
Assignee: UTAC Hong Kong Ltd
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Filing: 1999-12-03
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Granted: 2001-09-25
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Expires: 2019-12-03
Abstract
Abstract A leadless integrated circuit package, comprising an exposed semiconductor die and contact pads embedded in an over mold, and wires interconnecting the semiconductor die and contact pads. The leadless integrated circuit package is fabricated by etching a leadframe strip to define a plurality of contact pads; attaching an adhesive film to a bottom surface of the leadframe strip; mounting a semiconductor die to the adhesive film intermediate respective pairs of the contact pads; wire bonding the semiconductor die to the respective pairs of contact pads; encapsulating a top surface of the leadframe strip in a molding material; removing the adhesive film from the bottom surface of the leadframe strip for exposing the contact pads and the semiconductor die; solder plating the exposed bottom surface, and singulating the leadless integrated circuit package from the leadframe strip, whereby the adhesive film holds the semiconductor die in place prior to the encapsulating step, and prevents the molding material from contacting the exposed contact pads.
Inventors
- 👤 Nelson Fan
- 👤 Neil McLellan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 12:55
CPC Classifications
H; H10; H10W; H10W74/00; H10W74/10; H10W74/111; H10P; H10P72/00; H10P72/70; H10P72/74; H10W70/00; H10W70/01; H10W70/04; H10W70/042; H10W70/40; H10W70/421; H10W70/424; H10W72/00; H10W72/20; H10W74/01; H10W74/014; H10W74/019; H10P72/7438; H10W44/00; H10W44/20; H10W44/226; H10W72/01; H10W72/012; H10W72/01221; H10W72/01225; H10W72/0198; H10W72/071; H10W72/072; H10W72/07251; H10W72/075; H10W72/07502; H10W72/07504; H10W72/50; H10W72/541; H10W72/5449; H10W72/551; H10W72/552; H10W72/5522; H10W72/5524; H10W72/5525; H10W74/131; H10W74/142; H10W90/00; H10W90/701; H10W90/751; H10W90/756
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
144 words
A process for fabricating a leadless integrated circuit package, comprising the steps of: etching a leadframe strip to define a plurality of contact pads; attaching an adhesive film to a bottom surface of said leadframe strip; mounting a semiconductor die to said adhesive film intermediate respective pairs of said contact pads; wire bonding said semiconductor die to said respective pairs of contact pads; encapsulating a top surface of said leadframe strip in a molding material; removing said adhesive film from said bottom surface of said leadframe strip for exposing said contact pads and said semiconductor die; solder plating the exposed bottom surface of said leadframe strip; and singulating said leadless integrated circuit package from said leadframe strip, whereby said adhesive film holds said semiconductor die in place prior to said step of encapsulating, and prevents said molding material from contacting said exposed contact pads.
Claim 2
Dependent Claim
144 words
A process for fabricating a leadless integrated circuit package, comprising the steps of: etching a leadframe strip to define a plurality of contact pads; attaching an adhesive film to a bottom surface of said leadframe strip; mounting a semiconductor die to said adhesive film intermediate respective pairs of said contact pads; wire bonding said semiconductor die to said respective pairs of contact pads; encapsulating a top surface of said leadframe strip in a molding material; removing said adhesive film from said bottom surface of said leadframe strip for exposing said contact pads and said semiconductor die; solder plating the exposed bottom surface of said leadframe strip; and singulating said leadless integrated circuit package from said leadframe strip, whereby said adhesive film holds said semiconductor die in place prior to said step of encapsulating, and prevents said molding material from contacting said exposed contact pads.
Claim 3
Dependent Claim
46 words
The process of claim 1 , wherein said step of attaching the adhesive film to the bottom surface of said leadframe strip further comprises the steps of applying to said bottom surface a high temperature stable organic film which has been pre-coated with a tacky adhesive.
Claim 4
Dependent Claim
15 words
The process of claim 2 , wherein said organic film is high temperature stable polyimide.
Claim 5
Dependent Claim
28 words
The process of claim 1 , 2 , or 3 , further comprising the step of vapor depositing a layer of solderable material to the exposed semiconductor die.
Claim 6
Dependent Claim
13 words
The process of claim 4 , wherein said solderable material further comprises CrNiAu.
Claim 7
Dependent Claim
28 words
A leadless integrated circuit package, comprising an exposed semiconductor die and contact pads embedded in an over mold, and wires interconnecting said semiconductor die and said contact pads.
Claim 8
Dependent Claim
28 words
A leadless integrated circuit package, comprising an exposed semiconductor die and contact pads embedded in an over mold, and wires interconnecting said semiconductor die and said contact pads.
Claim 9
Dependent Claim
31 words
The leadless integrated circuit package of claim 6 , wherein at least one of said contact pads is circular in shape and inset relative to an outer edge of said package.
Claim 10
Dependent Claim
28 words
The leadless integrated circuit package of claim 6 , wherein at least one of said contact pads is rectangular and extends to an outer edge of said package.
Claim 11
Dependent Claim
27 words
The leadless integrated circuit package of claim 8 , wherein said at least one of said contact pads is provided with a notch for “pin one” indication.
Claim 12
Dependent Claim
23 words
The leadless integrated circuit package of claim 6 , further comprising a layer of solderable material vapor deposited to the exposed semiconductor die.
Claim 13
Dependent Claim
22 words
The leadless integrated circuit package of claim 10 , wherein said solderable material further comprises respective layers of chromium, nickel and gold.
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) | 2004-09-24 | 2005-03-26 | 2005-09-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2008-09-24 | 2009-03-26 | 2009-09-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2012-09-24 | 2013-03-26 | 2013-09-25 | $7700.00 | Window Closed / Lapsed |