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US5773876A Expired / Lapsed US ⏱️ 0.0 years remaining

Lead frame with electrostatic discharge protection

Assignee: National Semiconductor Corp
•
Filing: 1996-11-06
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Granted: 1998-06-30
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Expires: 2016-11-06
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Abstract

Abstract A lead frame having protection against electrostatic discharge is disclosed. The lead frame having protection against electrostatic discharge includes a multiplicity of leads and an electrostatic discharge protection device. The electrostatic discharge protection device includes a conductive layer and a protection layer. The protection layer is arranged to contact a plurality of leads and is formed from an electrostatic discharge protection material, which insulates the leads from the conductive layer at voltages below a predefined threshold voltage and establishes an electrical connection between the leads and the conductive layer at voltages above the threshold voltage.

Inventors

  • 👤 Boonmi Mekdhanasarn
  • 👤 Randy Hsiao-Yu Lo

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-09 13:36
CPC Classifications
H; H10; H10W; H10W70/00; H10W70/40; H10W42/00; H10W42/60; H10W72/00; H10W72/50; H10W72/541; H10W72/547; H10W72/5473; H10W74/00; H10W90/00; H10W90/701; H10W90/751; H10W90/756

Claims Analysis

Total Claims: 22
Claim 1
Independent Claim 83 words
A lead frame having protection against electrostatic discharge, comprising: a multiplicity of leads; and an electrostatic discharge protection device including a conductive layer and a protection layer formed from an electrostatic discharge protection material, the protection layer being arranged to contact the multiplicity of leads, wherein the electrostatic discharge protection material insulates the leads from the conductive layer at voltages below a predefined threshold voltage and establishes an electrical connection between the leads and the conductive layer at voltages above the threshold voltage.
Claim 2
Dependent Claim 83 words
A lead frame having protection against electrostatic discharge, comprising: a multiplicity of leads; and an electrostatic discharge protection device including a conductive layer and a protection layer formed from an electrostatic discharge protection material, the protection layer being arranged to contact the multiplicity of leads, wherein the electrostatic discharge protection material insulates the leads from the conductive layer at voltages below a predefined threshold voltage and establishes an electrical connection between the leads and the conductive layer at voltages above the threshold voltage.
Claim 3
Dependent Claim 43 words
A lead frame as recited in claim 1 wherein at least one of the multiplicity of leads is configured to function as a ground plane, the lead frame further comprising a grounding wire that electrically couples the conductive layer to the ground plane.
Claim 4
Dependent Claim 22 words
The lead frame of claim 1, wherein the electrostatic discharge protection device takes the form of a square ring shaped polymer tape.
Claim 5
Dependent Claim 21 words
The lead frame of claim 1, wherein the electrostatic discharge protection device takes the form of a strip of polymer tape.
Claim 6
Dependent Claim 22 words
The lead frame of claim 1, wherein the predefined threshold voltage is in a range between about 10 and about 500 volts.
Claim 7
Dependent Claim 26 words
The lead frame of claim 1, further comprising a silver plating overlying the conductive layer to facilitate electrically connecting a bonding wire to the conductive layer.
Claim 8
Dependent Claim 26 words
The lead frame of claim 1, wherein the electrostatic discharge protection device further comprises a spacer material disposed between the conductive layer and the protection layer.
Claim 9
Dependent Claim 63 words
The lead frame of claim 1, wherein the electrostatic discharge protection device further comprising: a conductive adhesive layer disposed between the conductive layer and the protection layer for securing the conductive layer to the protection layer; and an anisotropic adhesive layer disposed between the protection layer and a plurality of leads for securing the electrostatic discharge protection device to the plurality of leads.
Claim 10
Dependent Claim 14 words
The lead frame of claim 1, wherein the protection layer comprises a B-stageable polymer.
Claim 11
Dependent Claim 27 words
The lead frame of claim 8, wherein at least one of the protection layer, the conductive adhesive layer and the anisotropic adhesive layer comprises a B-stageable polymer.
Claim 12
Dependent Claim 22 words
The lead frame of claim 1, wherein the thickness of the protection layer ranges from between about 0.0002 to about 0.005 inches.
Claim 13
Dependent Claim 66 words
A packaged semiconductor device, comprising: the lead frame as recited in claim 1; a die having a plurality of bond pads; a plurality of bonding wires electrically connecting associated ones of the bond pads to associated ones of the leads; and an encapsulation material encapsulating a portion of the packaged semiconductor and leaving exposed a portion of the leads to facilitate electrical connection to external circuitry.
Claim 14
Dependent Claim 30 words
A packaged semiconductor device as recited in claim 12 that takes the form of a multi-chip module, the multi-chip module including a plurality of dies attached to the lead frame.
Claim 15
Dependent Claim 177 words
A packaged semiconductor device, comprising: a lead frame having protection against electrostatic discharge, including: a multiplicity of leads, wherein at least one of the multiplicity of leads is configured to function as a ground plane; an electrostatic discharge protection device including a spacer material being disposed between a conductive layer and a protection layer formed from an electrostatic discharge protection material, the protection layer being arranged to contact the multiplicity of leads, wherein the electrostatic discharge protection material insulates the leads from the conductive layer at voltages below a predefined threshold voltage and establishes an electrical connection between the leads and the conductive layer at voltages above the threshold voltage; and a grounding wire that electrically couples the conductive layer to the ground plane; a die having a plurality of bond pads; a plurality of bonding wires electrically connecting associated ones of the bond pads to associated ones of the leads; and an encapsulation material encapsulating a portion of the packaged semiconductor and leaving exposed a portion of the leads to facilitate electrical connection to external circuitry.
Claim 16
Dependent Claim 177 words
A packaged semiconductor device, comprising: a lead frame having protection against electrostatic discharge, including: a multiplicity of leads, wherein at least one of the multiplicity of leads is configured to function as a ground plane; an electrostatic discharge protection device including a spacer material being disposed between a conductive layer and a protection layer formed from an electrostatic discharge protection material, the protection layer being arranged to contact the multiplicity of leads, wherein the electrostatic discharge protection material insulates the leads from the conductive layer at voltages below a predefined threshold voltage and establishes an electrical connection between the leads and the conductive layer at voltages above the threshold voltage; and a grounding wire that electrically couples the conductive layer to the ground plane; a die having a plurality of bond pads; a plurality of bonding wires electrically connecting associated ones of the bond pads to associated ones of the leads; and an encapsulation material encapsulating a portion of the packaged semiconductor and leaving exposed a portion of the leads to facilitate electrical connection to external circuitry.
Claim 17
Dependent Claim 23 words
The packaged semiconductor device of claim 14, wherein the electrostatic discharge protection device takes the form of a square ring shaped polymer tape.
Claim 18
Dependent Claim 23 words
The packaged semiconductor device of claim 14, wherein the predefined threshold voltage is in a range between about 10 and about 500 volts.
Claim 19
Dependent Claim 27 words
The packaged semiconductor device of claim 14, further comprising a silver plating overlying the conductive layer to facilitate electrically connecting a bonding wire to the conductive layer.
Claim 20
Dependent Claim 64 words
The packaged semiconductor device of claim 14, wherein the electrostatic discharge protection device further comprising: a conductive adhesive layer disposed between the conductive layer and the protection layer for securing the conductive layer to the protection layer; and an anisotropic adhesive layer disposed between the protection layer and the plurality of leads for securing the electrostatic discharge protection device to the plurality of leads.
Claim 21
Dependent Claim 28 words
The packaged semiconductor device of claim 18, wherein at least one of the protection layer, the conductive adhesive layer and the anisotropic adhesive layer comprises a B-stageable polymer.
Claim 22
Dependent Claim 23 words
The packaged semiconductor device of claim 14, wherein the thickness of the protection layer ranges from between about 0.0002 to about 0.005 inches.

References Cited (Backward Citations)

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USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 2001-06-29 2001-12-29 2002-06-30 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2005-06-29 2005-12-29 2006-06-30 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2009-06-29 2009-12-29 2010-06-30 $7700.00 Window Closed / Lapsed

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