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US5448450A Expired / Lapsed US ⏱️ 0.0 years remaining

Lead-on-chip integrated circuit apparatus

Assignee: Tamiras Per Pte Ltd LLC
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Filing: 1991-10-28
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Granted: 1995-09-05
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Expires: 2011-10-28
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Abstract

Abstract A lead-on-chip integrated circuit package comprising at least one extremely thin adhesive layer transferred from a carrier onto the face of integrated circuit chips, and a lead frame laminated to the last adhesive layer, with cured adhesive acting as an insulator, integrated circuit chip connection pads bonded to and encapsulating the chip and lead frame. Thermally conductive and electrically insulating filling may be included with the adhesive to improve heat conduction from the IC. Compliant adhesive reduces thermally induced stresses between the lead frame and IC chip. Both the improved thermal performance and reduced moisture absorption of the encapsulated package improves the reliability of the integrated circuit package.

Inventors

  • 👤 Carmen D. Burns

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-04 23:21
CPC Classifications
H; H10; H10W; H10W70/00; H10W70/40; H10W70/411; H10W70/415; H10W70/417; H10W72/00; H10W72/01; H10W72/013; H10W72/30; H10P; H10P72/00; H10P72/70; H10P72/74; H10P72/7432; H10W72/071; H10W72/0711; H10W72/07141; H10W72/07173; H10W72/073; H10W72/50; H10W72/531; H10W72/5363; H10W72/551; H10W72/552; H10W74/00; H10W90/00; H10W90/701; H10W90/751; H10W90/756; Y; Y10; Y10T; Y10T428/00; Y10T428/28; Y10T428/2835

Claims Analysis

Total Claims: 11
Claim 1
Independent Claim 136 words
A lead-on-chip integrated circuit package having good thermal conductivity for efficient transfer of heat contained therein comprising: an integrated circuit chip having a face with circuit connection pads thereon; a first layer of adhesive on said face of said integrated circuit chip wherein said circuit connection pads are exposed; said first layer of adhesive cured to form an insulator on the face of said integrated circuit; a second layer of adhesive on said cured first layer of adhesive wherein said circuit connection pads are exposed; a lead frame having tips and a plurality of electrical conductors, wherein a substantial portion of said lead frame is laminated to said second layer of adhesive and fixedly aligned with said integrated circuit connection pads for connection thereto; and an encapsulating case surrounding said integrated circuit chip and lead frame.
Claim 2
Dependent Claim 136 words
A lead-on-chip integrated circuit package having good thermal conductivity for efficient transfer of heat contained therein comprising: an integrated circuit chip having a face with circuit connection pads thereon; a first layer of adhesive on said face of said integrated circuit chip wherein said circuit connection pads are exposed; said first layer of adhesive cured to form an insulator on the face of said integrated circuit; a second layer of adhesive on said cured first layer of adhesive wherein said circuit connection pads are exposed; a lead frame having tips and a plurality of electrical conductors, wherein a substantial portion of said lead frame is laminated to said second layer of adhesive and fixedly aligned with said integrated circuit connection pads for connection thereto; and an encapsulating case surrounding said integrated circuit chip and lead frame.
Claim 3
Dependent Claim 21 words
The integrated circuit of claim 1, wherein said second layer of adhesive is from 0.25 mils to 2 mils in thickness.
Claim 4
Dependent Claim 14 words
The integrated circuit of claim 1, wherein said second layer of adhesive is compliant.
Claim 5
Dependent Claim 14 words
The integrated circuit of claim 3, wherein said compliant adhesive is phenolic butyryl epoxy.
Claim 6
Dependent Claim 14 words
The integrated circuit of claim 1, wherein said second layer of adhesive is B-staged.
Claim 7
Dependent Claim 18 words
The integrated circuit of claim 1, wherein said second layer of adhesive is a low moisture absorption adhesive.
Claim 8
Dependent Claim 36 words
The integrated circuit of claim 1, wherein said lead frame tips are selectively etched in order to reduce the space required for connection of said tips to said connection pads, thus reducing the overall package thickness.
Claim 9
Dependent Claim 27 words
The integrated circuit of claim 7, wherein said lead frame tips are bent slightly away from the face of said integrated circuit chip to prevent shorting thereto.
Claim 10
Dependent Claim 131 words
A lead-on-chip integrated circuit package having good thermal conductivity for efficient transfer of heat contained therein comprising: an integrated circuit chip having a face with circuit connection pads thereon; at least two layers of adhesive on said face of said integrated circuit chip wherein said circuit connection pads are exposed; at least one layer of adhesive cured to form an insulator on said face of said integrated circuit; and a lead frame having a plurality of electrical conductors, a substantial portion of said lead frame being laminated to a last layer of adhesive and fixedly aligned with said integrated circuit connection pads for connection thereto, wherein said insulator prevents said lead frame from shorting to said integrated circuit chip; and an encapsulating case surrounding said integrated circuit chip and lead frame.
Claim 11
Dependent Claim 131 words
A lead-on-chip integrated circuit package having good thermal conductivity for efficient transfer of heat contained therein comprising: an integrated circuit chip having a face with circuit connection pads thereon; at least two layers of adhesive on said face of said integrated circuit chip wherein said circuit connection pads are exposed; at least one layer of adhesive cured to form an insulator on said face of said integrated circuit; and a lead frame having a plurality of electrical conductors, a substantial portion of said lead frame being laminated to a last layer of adhesive and fixedly aligned with said integrated circuit connection pads for connection thereto, wherein said insulator prevents said lead frame from shorting to said integrated circuit chip; and an encapsulating case surrounding said integrated circuit chip and lead frame.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1998-09-04 1999-03-06 1999-09-05 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2002-09-04 2003-03-06 2003-09-05 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2006-09-04 2007-03-06 2007-09-05 $7700.00 Window Closed / Lapsed

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