US4377619A
Expired / Lapsed
US
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Prevention of surface mass migration by means of a polymeric surface coating
Assignee: AT&T Inc
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Filing: 1981-05-08
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Granted: 1983-03-22
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Expires: 2001-05-08
Abstract
Abstract Method for preventing spreading of a liquid on a solid surface, e.g., an adhesive placed on a substrate, and for preventing metal migration, in particular silver migration, between conductors deposited on a surface of a substrate, and articles produced by the method. The method comprises application of a layer of polymer having room temperature critical surface tension of wetting less than about 20 dyn/cm, and less than about 0.1 μm thick, to at least a part of the surface. The polymer layer can be applied by any convenient method, including dipping, spraying, painting, printing, and plasma deposition. A preferred polymer is poly(1H, 1H-pentadecafluorooctyl methacrylate) (PDFOM), which can be advantageously applied in the form of a solution, typically in a fluorinated hydrocarbon such as Freon® TF, with PDFOM concentration typically between about 0.001% and about 2% by weight. Thin PDFOM layers according to the invention covering the substrate area on which the adhesive is placed later do not unduly decrease the strength of the adhesive bond formed, and have no measurable effect on the electrical conductivity of a conducting adhesive bond. Because of these properties, a substrate surface can be coated with PDFOM, such as by dipping or spraying, and the adhesive be applied to the coated surface. Metal migration is prevented by preventing formation of a continuous electrolyte film, typically an aqueous film, between conductors at different electrical potentials. This can be achieved by coating at least a part of the substrate with the polymer, e.g., PDFOM.
Inventors
- 👤 Harold Schonhorn
- 👤 Louis H. Sharpe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 20:56
CPC Classifications
H; H10; H10W; H10W20/00; H10W20/40; H10W20/45; H10W20/48; H05; H05K; H05K3/00; H05K3/22; H05K3/28; H10W72/00; H10W72/30; H05K2201/00; H05K2201/07; H05K2201/0753; H05K2201/0769; H05K3/30; H05K3/303; H05K3/305; H05K3/32; H05K3/321; H10W72/071; H10W72/074; H10W72/50; H10W72/59; H10W72/90; H10W72/941; H10W72/9415; H10W72/951; H10W72/953; H10W90/00; H10W90/701; H10W90/731; H10W90/734; Y; Y10; Y10S; Y10S428/00; Y10S428/901; Y10T; Y10T428/00; Y10T428/26; Y10T428/261; Y10T428/263; Y10T428/264; Y10T428/265; Y10T428/269
Claims Analysis
Total Claims: 36
Claim 1
Independent Claim
103 words
Method for fabricating an article comprising a substrate having at least one first surface region covered with a substance at least part of which is capable of undergoing surface mass migration, and at least one second surface region that is not covered with the substance, the method comprising (a) applying a layer of material to at least part of the second surface region, characterized in that (b) the material comprises a polymer having a critical surface tension of wetting of less than about 20 dyn/cm at room temperature, and (c) the layer of material applied is no more than approximately 0.1 μm thick.
Claim 2
Dependent Claim
103 words
Method for fabricating an article comprising a substrate having at least one first surface region covered with a substance at least part of which is capable of undergoing surface mass migration, and at least one second surface region that is not covered with the substance, the method comprising (a) applying a layer of material to at least part of the second surface region, characterized in that (b) the material comprises a polymer having a critical surface tension of wetting of less than about 20 dyn/cm at room temperature, and (c) the layer of material applied is no more than approximately 0.1 μm thick.
Claim 3
Dependent Claim
26 words
Method of claim 1, wherein the substance capable of undergoing surface mass migration comprises a liquid, and the mass migration is spontaneous spreading of the liquid.
Claim 4
Dependent Claim
29 words
Method of claim 1, wherein the layer of material is applied also to at least part of the first surface region before that region is covered with the substance.
Claim 5
Dependent Claim
70 words
Method of claim 1, wherein the layer of material is applied to the first and second surface regions before the first region is covered with the substance, the substance is an adhesive, and the strength after curing of the bond between adhesive and substrate is no less than about 50% of the strength of a bond formed between adhesive and substrate in the absence of the layer of material thereon.
Claim 6
Dependent Claim
53 words
Method of claim 1 wherein the substance covering the first surface region is an adhesive, a solid item to be bonded to the substrate is placed in contact with the adhesive, and the layer of material is applied after placing the item in contact with the adhesive, but prior to curing the adhesive.
Claim 7
Dependent Claim
31 words
Method of claim 1 wherein the substance capable of undergoing surface mass migration is a metal comprising an electrical conductor disposed on the substrate, and the mass migration is metal migration.
Claim 8
Dependent Claim
28 words
Method of claims 2 or 6 wherein the layer of material is applied by contacting at least part of the surface regions with a solution comprising the polymer.
Claim 9
Dependent Claim
34 words
Method of claim 7 wherein the polymer is poly (1H, 1H-pentadecafluorooctyl methacrylate), the solvent is a fluorinated hydrocarbon and the concentration of the polymer in the solvent is at least about 0.001% by weight.
Claim 10
Dependent Claim
20 words
Method of claim 8, wherein the concentration of the polymer in the solvent is less than about 2% by weight.
Claim 11
Dependent Claim
24 words
Method of claims 2 or 6 wherein the applying of the material is done by dipping the substrate into a solution comprising the polymer.
Claim 12
Dependent Claim
24 words
Method of claims 2 or 6 wherein the applying of the material is done by spraying the substrate with a solution comprising the polymer.
Claim 13
Dependent Claim
9 words
Method of claim 6 wherein the conductor comprises silver.
Claim 14
Dependent Claim
20 words
Method of claim 12 wheren the layer of material is applied only to a part of the second surface region.
Claim 15
Dependent Claim
23 words
Method of claim 12 wherein the layer of material is applied to the conductor and at least part of the second surface region.
Claim 16
Dependent Claim
97 words
Method for fabricating an article comprising a substrate and a solid item affixed to a surface of the substrate by means of adhesive bonding, the method comprising (a) contacting, prior to application of the adhesive, at least part of the surface of the substrate with an amount of a 0.001% to 2% by weight solution of poly (1H, 1H-pentadecafluorooctyl methacrylate) (PDFOM), the amount being sufficient to result in formation on the surface of a layer of PDFOM less than about 0.1 μm thick, and (b) placing the adhesive and the solid item onto the PDFOM-covered substrate surface.
Claim 17
Dependent Claim
97 words
Method for fabricating an article comprising a substrate and a solid item affixed to a surface of the substrate by means of adhesive bonding, the method comprising (a) contacting, prior to application of the adhesive, at least part of the surface of the substrate with an amount of a 0.001% to 2% by weight solution of poly (1H, 1H-pentadecafluorooctyl methacrylate) (PDFOM), the amount being sufficient to result in formation on the surface of a layer of PDFOM less than about 0.1 μm thick, and (b) placing the adhesive and the solid item onto the PDFOM-covered substrate surface.
Claim 18
Dependent Claim
98 words
Method for fabricating an article comprising a substrate and a solid item affixed to a surface of the substrate by means of adhesive bonding, the method comprising (a) placing the adhesive and the solid item onto the surface of the substrate, and thereafter, but prior to curing the adhesive, (b) contacting at least part of the surface of the substrate with an amount of a 0.001% to 2% by weight solution of poly(1H, 1H-pentadecafluorooctyl methacrylate) (PDFOM), the amount being sufficient to result in formation on the surface of a layer of PDFOM less than about 0.1 μm thick.
Claim 19
Dependent Claim
98 words
Method for fabricating an article comprising a substrate and a solid item affixed to a surface of the substrate by means of adhesive bonding, the method comprising (a) placing the adhesive and the solid item onto the surface of the substrate, and thereafter, but prior to curing the adhesive, (b) contacting at least part of the surface of the substrate with an amount of a 0.001% to 2% by weight solution of poly(1H, 1H-pentadecafluorooctyl methacrylate) (PDFOM), the amount being sufficient to result in formation on the surface of a layer of PDFOM less than about 0.1 μm thick.
Claim 20
Dependent Claim
75 words
Method for fabricating an article comprising a plurality of spaced apart electrical conductors comprisng metallic silver deposited on an insulating substrate, the method comprising contacting at least part of the surface of the substrate bearing the conductor with an amount of a 0.001% to 2% by weight solution of poly (1H,1H-pentadecafluorooctyl methacrylate) (PDFOM), the amount being sufficient to result in formation on the surface of a layer of PDFOM less than about 0.1 μm thick.
Claim 21
Dependent Claim
75 words
Method for fabricating an article comprising a plurality of spaced apart electrical conductors comprisng metallic silver deposited on an insulating substrate, the method comprising contacting at least part of the surface of the substrate bearing the conductor with an amount of a 0.001% to 2% by weight solution of poly (1H,1H-pentadecafluorooctyl methacrylate) (PDFOM), the amount being sufficient to result in formation on the surface of a layer of PDFOM less than about 0.1 μm thick.
Claim 22
Dependent Claim
15 words
Method of claims 15, 16, or 17 wherein PDFOM is dissolved in a fluorinated hydrocarbon.
Claim 23
Dependent Claim
74 words
Article comprising (a) a substrate, and (b) a semiconductor electronic device affixed to a substrate surface by means of an adhesive, characterized in that (c) a layer, consisting essentially of polymer having a room temperature critical surface tension of wetting less than about 20 dyn/cm, the layer being less than about 0.1 μm thick, is disposed over at least a part of the substrate surface including the area to which the device is affixed.
Claim 24
Dependent Claim
74 words
Article comprising (a) a substrate, and (b) a semiconductor electronic device affixed to a substrate surface by means of an adhesive, characterized in that (c) a layer, consisting essentially of polymer having a room temperature critical surface tension of wetting less than about 20 dyn/cm, the layer being less than about 0.1 μm thick, is disposed over at least a part of the substrate surface including the area to which the device is affixed.
Claim 25
Dependent Claim
74 words
Article comprising (a) a substrate, and (b) a semiconductor electronic device affixed to a substrate surface by means of an adhesive, characterized in that (c) a layer, consisting essentially of polymer having a room temperature critical surface tension of wetting less than about 20 dyn/cm, the layer being less than about 0.1 μm thick, is disposed over at least a part of the substrate surface and over at least a part of the device.
Claim 26
Dependent Claim
74 words
Article comprising (a) a substrate, and (b) a semiconductor electronic device affixed to a substrate surface by means of an adhesive, characterized in that (c) a layer, consisting essentially of polymer having a room temperature critical surface tension of wetting less than about 20 dyn/cm, the layer being less than about 0.1 μm thick, is disposed over at least a part of the substrate surface and over at least a part of the device.
Claim 27
Dependent Claim
68 words
Article comprising (a) a substrate, and (b) a plurality of spaced apart electrical conductors comprising metallic silver deposited on a surface of the substrate, characterized in that (c) a layer, consisting essentially of polymer having a room temperature critical surface tension of wetting less than about 20 dyn/cm, the layer being less than about 0.1 μm thick, is disposed over at least a part of the substrate surface.
Claim 28
Dependent Claim
68 words
Article comprising (a) a substrate, and (b) a plurality of spaced apart electrical conductors comprising metallic silver deposited on a surface of the substrate, characterized in that (c) a layer, consisting essentially of polymer having a room temperature critical surface tension of wetting less than about 20 dyn/cm, the layer being less than about 0.1 μm thick, is disposed over at least a part of the substrate surface.
Claim 29
Dependent Claim
18 words
Article according to claim 21 wherein the layer is disposed also over at least one of the conductors.
Claim 30
Dependent Claim
16 words
Article according to claims 19, 20, or 21 wherein the polymer is poly (1H, 1H-pentadecafluorooctyl methacrylate).
Claim 31
Dependent Claim
77 words
Method for manufacturing an article comprising a substrate and a semiconductor device affixed to a substrate surface by means of an adhesive,characterized in that the method comprises disposing a layer, consisting essentially of polymer having a room temperature critical surface tension of wetting less than about 20 dyn/cm, the layer being less than about 0.1 μm thick, over at least a part of the substrate surface including the area to which the device is to be affixed.
Claim 32
Dependent Claim
77 words
Method for manufacturing an article comprising a substrate and a semiconductor device affixed to a substrate surface by means of an adhesive,characterized in that the method comprises disposing a layer, consisting essentially of polymer having a room temperature critical surface tension of wetting less than about 20 dyn/cm, the layer being less than about 0.1 μm thick, over at least a part of the substrate surface including the area to which the device is to be affixed.
Claim 33
Dependent Claim
76 words
Method for manufacturing an article comprising a substrate and a semiconductor device affixed to a substrate surface by means of an adhesive characterized in that the method comprises disposing a layer, consisting essentially of polymer having a room temperature critical surface tension of wetting less than about 20 dyn/cm, the layer being less than about 0.1 μm thick, over at least a part of the substrate surface and over at least a part of the device.
Claim 34
Dependent Claim
76 words
Method for manufacturing an article comprising a substrate and a semiconductor device affixed to a substrate surface by means of an adhesive characterized in that the method comprises disposing a layer, consisting essentially of polymer having a room temperature critical surface tension of wetting less than about 20 dyn/cm, the layer being less than about 0.1 μm thick, over at least a part of the substrate surface and over at least a part of the device.
Claim 35
Dependent Claim
71 words
Method for manufacturng an article comprising a substrate and a plurality of spaced apart electrical conductors comprising metallic silver deposited on a surface of the substrate, characterized in that the method comprises disposing a layer, consisting essentially of polymer having a room temperature critical surface tension of wetting less than about 20 dyn/cm, the layer being less than about 0.1 μm thick, over at least a part of the substrate surface.
Claim 36
Dependent Claim
71 words
Method for manufacturng an article comprising a substrate and a plurality of spaced apart electrical conductors comprising metallic silver deposited on a surface of the substrate, characterized in that the method comprises disposing a layer, consisting essentially of polymer having a room temperature critical surface tension of wetting less than about 20 dyn/cm, the layer being less than about 0.1 μm thick, over at least a part of the substrate surface.
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) | 1986-03-21 | 1986-09-20 | 1987-03-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-03-21 | 1990-09-20 | 1991-03-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-03-21 | 1994-09-20 | 1995-03-22 | $7700.00 | Window Closed / Lapsed |