US5122858A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Lead frame having polymer coated surface portions
Assignee: Olin Corp
•
Filing: 1990-09-10
•
Granted: 1992-06-16
•
Expires: 2010-09-10
Abstract
Abstract A composite leadframe for electronic packages is provided. A polymer layer coats a portion of the leadframe. The polymer layer increases the adhesive bond between the leadframe and a molding resin. Water vapor does not accumulate under the leads and die attach paddle minimizing the popcorn effect.
Inventors
- 👤 Deepak Mahulikar
- 👤 Julius C. Fister
- 👤 Gerald N. Violette
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 19:55
CPC Classifications
H; H10; H10W; H10W70/00; H10W70/40; H10W70/456; H10W70/458; H10W74/00; H10W74/10; H10W74/111; H10W74/127; H10W72/00; H10W72/50; H10W72/551; H10W72/552; H10W72/5522; H10W72/5524; H10W72/5525; H10W90/00; H10W90/701; H10W90/751; H10W90/756
Claims Analysis
Total Claims: 37
Claim 1
Independent Claim
94 words
A leadframe for an electronic package, comprising: a conductor having a plurality of leads with inner and outer portions, said inner portions defining a central aperture; a die attach paddle located within said central aperture and having first and second major surfaces, said first major surface adapted to receive an electronic device; a first polymer coating on at least a portion of said inner leads and on said second major surface of said die attach paddle; and a second polymer coating which is conductive on said first major surface of said die attach paddle.
Claim 2
Dependent Claim
94 words
A leadframe for an electronic package, comprising: a conductor having a plurality of leads with inner and outer portions, said inner portions defining a central aperture; a die attach paddle located within said central aperture and having first and second major surfaces, said first major surface adapted to receive an electronic device; a first polymer coating on at least a portion of said inner leads and on said second major surface of said die attach paddle; and a second polymer coating which is conductive on said first major surface of said die attach paddle.
Claim 3
Dependent Claim
20 words
The leadframe of claim 1 wherein said first polymer coats the entire inner lead portion except for the lead tips.
Claim 4
Dependent Claim
12 words
The leadframe of claim 1 wherein said conductor is a copper alloy.
Claim 5
Dependent Claim
14 words
The leadframe of claim 2 wherein said second polymer is a silver filled epoxy.
Claim 6
Dependent Claim
22 words
The leadframe of claim 2 wherein said first polymer is selected from the group consisting of polyolefins, polyimides, epoxies, acrylics and urethanes.
Claim 7
Dependent Claim
12 words
The leadframe of claim 5 wherein said first polymer is an epoxy.
Claim 8
Dependent Claim
20 words
The leadframe of claim 6 wherein said first polymer has a thickness of from about 0.0005 to about 0.020 inches.
Claim 9
Dependent Claim
20 words
The leadframe of claim 7 wherein said first polymer has a thickness of from about 0.001 to about 0.005 inches.
Claim 10
Dependent Claim
21 words
The leadframe of claim 8 wherein said first polymer is an epoxy sheet of a desired thickness tacked to said conductor.
Claim 11
Dependent Claim
19 words
The leadframe of claim 7 wherein an adhesion promoting layer is disposed between said first polymer and said conductor.
Claim 12
Dependent Claim
24 words
The leadframe of claim 10 wherein said adhesion promoting layer is selected from the group consisting of refractory oxides, dull nickel, phosphates, and polymers.
Claim 13
Dependent Claim
29 words
The leadframe of claim 11 wherein said adhesion promoting layer is a polymer selected from the group consisting of benzotriazole, benzothiazole, mercaptoester, 5-carboxy-benzotriazole, 5-(1-aminoethylamido)-benzotriazole, 5-amido-benzotriazole and ethylene vinyl acetate.
Claim 14
Dependent Claim
25 words
The leadframe of claim 12 wherein said adhesion promoting layer is ethylene vinyl acetate having a thickness of from about 20 to about 100 angstroms.
Claim 15
Dependent Claim
26 words
The leadframe of claim 1 wherein said first polymer is selected from the group consisting of benzotriazole, benzothiazole, mercaptoester, 5-carboxy-benzotriazole, 5-(1-amino-ethylamido)benzotriazole, 5-amido-benzotriazole and ethylene vinyl acetate.
Claim 16
Dependent Claim
24 words
The leadframe of claim 1 wherein said first polymer is ethylene vinyl acetate having a thickness of from about 20 to about 100 angstroms.
Claim 17
Dependent Claim
86 words
A leadframe for an electronic package, comprising: a conductor having a plurality of leads with inner and outer portions, said inner portions defining a central aperture; a die attach paddle located within said central aperture and having first and second major surfaces, said first major surface adapted to receive an electronic device; and a polymer coating at least a portion of said inner leads and the second surface of said die attach paddle, said polymer coating having a thickness from about 0.0005 to about 0.020 inches.
Claim 18
Dependent Claim
86 words
A leadframe for an electronic package, comprising: a conductor having a plurality of leads with inner and outer portions, said inner portions defining a central aperture; a die attach paddle located within said central aperture and having first and second major surfaces, said first major surface adapted to receive an electronic device; and a polymer coating at least a portion of said inner leads and the second surface of said die attach paddle, said polymer coating having a thickness from about 0.0005 to about 0.020 inches.
Claim 19
Dependent Claim
12 words
The leadframe of claim 16 wherein said conductor is a copper alloy.
Claim 20
Dependent Claim
35 words
The leadframe of claim 17 wherein said polymer coating is in the form of a preform tacked to both said inner portion of the leads and to said second surface of said die attach paddle.
Claim 21
Dependent Claim
21 words
The leadframe of claim 18 wherein said polymer is selected from the group consisting of polyolefins, polyimides, epoxies, acrylics and urethanes.
Claim 22
Dependent Claim
11 words
The leadframe of claim 19 wherein said polymer is an epoxy.
Claim 23
Dependent Claim
19 words
The leadframe of claim 20 wherein said polymer has a thickness of from about 0.001 to about 0.005 inches.
Claim 24
Dependent Claim
18 words
The leadframe of claim 20 wherein an adhesion promoting layer is disposed between said polymer and said conductor.
Claim 25
Dependent Claim
24 words
The leadframe of claim 22 wherein said adhesion promoting layer is selected from the group consisting of refractory oxides, dull nickel, phosphates, and polymers.
Claim 26
Dependent Claim
29 words
The leadframe of claim 23 wherein said adhesion promoting layer is a polymer selected from the group consisting of benzotriazole, benzothiazole, mercaptoester, 5-carboxy-benzotriazole, 5-(1-amino-ethylamido)-benzotriazole, 5-amido-benzotriazole and ethylene vinyl acetate.
Claim 27
Dependent Claim
25 words
The leadframe of claim 24 wherein said adhesion promoting layer is ethylene vinyl acetate having a thickness of from about 20 to about 100 angstroms.
Claim 28
Dependent Claim
93 words
The leadframe for an electronic package, comprising: a conductor having a plurality of leads with inner and outer portions, said inner portions defining a central aperture; a die attach paddle located within said central aperture and having first and second major surfaces, said first major surface adapted to receive an electronic device; and a polymer coating at least a portion of both said inner leads and said second major surface of said die attach paddle, said polymer selected from the group consisting of benzotriazole, benzothiazole, mercaptoester, 5-carboxy-benzotriazole, 5-(1-amino-ethylamido)-benzotriazole, 5-amido-benzotriazole and ethylene vinyl acetate.
Claim 29
Dependent Claim
93 words
The leadframe for an electronic package, comprising: a conductor having a plurality of leads with inner and outer portions, said inner portions defining a central aperture; a die attach paddle located within said central aperture and having first and second major surfaces, said first major surface adapted to receive an electronic device; and a polymer coating at least a portion of both said inner leads and said second major surface of said die attach paddle, said polymer selected from the group consisting of benzotriazole, benzothiazole, mercaptoester, 5-carboxy-benzotriazole, 5-(1-amino-ethylamido)-benzotriazole, 5-amido-benzotriazole and ethylene vinyl acetate.
Claim 30
Dependent Claim
12 words
The leadframe of claim 26 wherein said conductor is a copper alloy.
Claim 31
Dependent Claim
19 words
The leadframe of claim 27 wherein said polymer has a thickness of from about 0.0005 to about 0.020 inches.
Claim 32
Dependent Claim
19 words
The leadframe of claim 28 wherein said polymer has a thickness of from about 0.001 to about 0.005 inches.
Claim 33
Dependent Claim
16 words
The leadframe of claim 29 wherein said polymer is an epoxy sheet tacked to said conductor.
Claim 34
Dependent Claim
19 words
The leadframe of claim 28 wherein an adhesion promoting layer is disposed between said first polymer and said conductor.
Claim 35
Dependent Claim
24 words
The leadframe of claim 31 wherein said adhesion promoting layer is selected form the group consisting of refractory oxides, dull nickel, phosphates, and polymers.
Claim 36
Dependent Claim
24 words
The leadframe of claim 28 wherein said first polymer is ethylene vinyl acetate having a thickness of from about 20 to about 100 angstroms.
Claim 37
Dependent Claim
24 words
The leadframe of claim 32 wherein said first polymer is ethylene vinyl acetate having a thickness of from about 20 to about 100 angstroms.
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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) | 1995-06-16 | 1995-12-16 | 1996-06-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-06-16 | 1999-12-16 | 2000-06-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-06-16 | 2003-12-16 | 2004-06-16 | $7700.00 | Window Closed / Lapsed |