US5229192A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Flame-resistant cover film for flexible circuit boards
Assignee: Carl Freudenberg KG
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Filing: 1991-08-21
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Granted: 1993-07-20
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Expires: 2011-08-21
Abstract
Abstract A flame-resistant cover film for flexible circuit boards having excellent flame-resistance, handling, and storage qualities may be produced by treating an insulating film of a nonwoven polymer fabric with a flame-resistant, halogen-free polymeric adhesive. The polymeric adhesive comprises an aqueous mixture of a copolymerizate of acrylic acid esters and styrene, and an aminoplastic or phenoplastic precondensate to which a mixture of fine-particle red phosphorus and fine-particle ammonium polyphosphate is also added.
Inventors
- 👤 Horst Kober
- 👤 Thomas Kuhlmann
- 👤 Jorg Hausdorf
- 👤 Steffen Kosack
- 👤 Werner Schafer
- 👤 Volker Siekermann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 13:54
CPC Classifications
H; H05; H05K; H05K3/00; H05K3/22; H05K3/28; H05K3/281; C; C08; C08K; C08K3/00; C08K3/02; C08K3/32; H01; H01B; H01B3/00; H01B3/18; H01B3/30; H01B3/44; H05K1/00; H05K1/02; H05K1/03; H05K1/0393; H05K2201/00; H05K2201/01; H05K2201/0104; H05K2201/012; H05K2201/02; H05K2201/0275; H05K2201/0284; H05K2201/0293; Y; Y10; Y10S; Y10S428/00; Y10S428/901; Y10T; Y10T428/00; Y10T428/24; Y10T428/24802; Y10T428/24917
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
195 words
A flame-resistant flexible printed circuit board comprising: a flexible printed circuit board, an aqueous, halogen-free polymeric composition applied in an amount of about 30 to 60 g/m 2 (dry) to an insulating film, wherein said insulating film comprises a nonwoven fabric having the following specifications: area weight: 49 g/m 2 , thickness: 0.071 mm, maximum tensile strength: 134 N, expansion: 24%, and air permeability: 207 dm 3 /s/m 2 , and said polymeric composition comprises a cross-linked product of: (a) about a 50% aqueous dispersion of a thermally cross-linkable copolymerizate of acrylic acid esters and styrene having a glass transition temperature of about +31° C., (b) about a 60% aqueous solution including hydroxymethyl groups, selected from the group consisting of aminoplastics and phenoplastics, where the ratio of (a):(b) (dry) is about 10.0:0.8 to 10.0:2.0, (c) red phosphorus with a grain size of 0.045 to 0.10 mm, and (d) ammonium polyphosphate with a grain size of 0.025 to 0.075 mm are added, where the ratio of (c):(d) is about 1.0:10.0, and the ratio of ((a)+(b)) to ((c)+(d)) is about 1.0:09, and said insulating film is adhered to said flexible printed circuit board under heat and pressure.
Claim 2
Dependent Claim
195 words
A flame-resistant flexible printed circuit board comprising: a flexible printed circuit board, an aqueous, halogen-free polymeric composition applied in an amount of about 30 to 60 g/m 2 (dry) to an insulating film, wherein said insulating film comprises a nonwoven fabric having the following specifications: area weight: 49 g/m 2 , thickness: 0.071 mm, maximum tensile strength: 134 N, expansion: 24%, and air permeability: 207 dm 3 /s/m 2 , and said polymeric composition comprises a cross-linked product of: (a) about a 50% aqueous dispersion of a thermally cross-linkable copolymerizate of acrylic acid esters and styrene having a glass transition temperature of about +31° C., (b) about a 60% aqueous solution including hydroxymethyl groups, selected from the group consisting of aminoplastics and phenoplastics, where the ratio of (a):(b) (dry) is about 10.0:0.8 to 10.0:2.0, (c) red phosphorus with a grain size of 0.045 to 0.10 mm, and (d) ammonium polyphosphate with a grain size of 0.025 to 0.075 mm are added, where the ratio of (c):(d) is about 1.0:10.0, and the ratio of ((a)+(b)) to ((c)+(d)) is about 1.0:09, and said insulating film is adhered to said flexible printed circuit board under heat and pressure.
Claim 3
Dependent Claim
190 words
A flame-resistant flexible printed circuit board comprising: a flexible printed circuit board, an aqueous, halogen-free polymeric composition applied in an amount of 40 g/m 2 (dry) to an insulating film, wherein said insulating film comprises a nonwoven fabric having the following specifications: area weight: 49 g/m 2 , thickness: 0.071 mm, maximum tensile strength: 134 N, expansion: 24%, and air permeability: 207 dm 3 /s/m 2 , and said polymeric composition comprises a cross-linked product of: (a) a 50% aqueous dispersion of a thermally cross-linkable copolymerizate of acrylic acid esters and styrene having a glass transition temperature of about +31° C., (b) a 60% aqueous solution including hydroxymethyl groups, selected from the group consisting of aminoplastics and phenoplastics, where the ratio of (a):(b) (dry) is about 10.0:0.8 to 10.0:2.0, (c) red phosphorus with a grain size of 0.045 to 0.10 mm, and (d) ammonium polyphosphate with a grain size of 0.025 to 0.075 mm are added, where the ration of (c):(d) is about 1.0:10.0, and the ratio of ((a)+(b)) to ((c)+(d)) is about 1.0:0.9, and said insulating film is adhered to said flexible printed circuit board under heat and pressure.
Claim 4
Dependent Claim
190 words
A flame-resistant flexible printed circuit board comprising: a flexible printed circuit board, an aqueous, halogen-free polymeric composition applied in an amount of 40 g/m 2 (dry) to an insulating film, wherein said insulating film comprises a nonwoven fabric having the following specifications: area weight: 49 g/m 2 , thickness: 0.071 mm, maximum tensile strength: 134 N, expansion: 24%, and air permeability: 207 dm 3 /s/m 2 , and said polymeric composition comprises a cross-linked product of: (a) a 50% aqueous dispersion of a thermally cross-linkable copolymerizate of acrylic acid esters and styrene having a glass transition temperature of about +31° C., (b) a 60% aqueous solution including hydroxymethyl groups, selected from the group consisting of aminoplastics and phenoplastics, where the ratio of (a):(b) (dry) is about 10.0:0.8 to 10.0:2.0, (c) red phosphorus with a grain size of 0.045 to 0.10 mm, and (d) ammonium polyphosphate with a grain size of 0.025 to 0.075 mm are added, where the ration of (c):(d) is about 1.0:10.0, and the ratio of ((a)+(b)) to ((c)+(d)) is about 1.0:0.9, and said insulating film is adhered to said flexible printed circuit board under heat and pressure.
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) | 1996-07-19 | 1997-01-18 | 1997-07-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-07-19 | 2001-01-18 | 2001-07-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-07-19 | 2005-01-18 | 2005-07-20 | $7700.00 | Window Closed / Lapsed |