US4501787A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Flame retardant B-staged epoxy resin prepregs and laminates made therefrom
Assignee: Isola Laminate Systems Corp
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Filing: 1983-04-29
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Granted: 1985-02-26
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Expires: 2003-04-29
Abstract
Abstract A prepreg useful in flame resistant copper clad printed circuit boards is made by impregnating a porous substrate with an impregnant containing: either a prebrominated epoxy resin or a mixture of a non-halogenated epoxy resin and flame retarding additive containing bromine, and phenolic hydroxyl groups. A phenolic novolac oligomer having an average of over 2.5 phenolic hydroxyl groups per oligomeric unit is used as curing agent. Optionally, a suitable catalyst may be included. The impregnated substrate is heated to cure or advance the resin to the "B"-stage.
Inventors
- 👤 Joseph R. Marchetti
- 👤 Wilbur R. Thomas
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 09:03
CPC Classifications
B; B32; B32B; B32B5/00; B32B5/22; B32B5/24; B32B5/26; B32B15/00; B32B15/04; B32B15/08; B32B15/14; B32B15/20; B32B29/00; B32B29/02; B32B5/02; B32B5/022; B32B5/024; H; H05; H05K; H05K1/00; H05K1/02; H05K1/03; H05K1/0313; H05K1/032; H05K1/034; H05K1/0353; H05K1/036; H05K1/0373; B32B2260/00; B32B2260/02; B32B2260/021; B32B2260/028; B32B2260/04; B32B2260/046; B32B2305/00; B32B2305/02; B32B2305/026; B32B2307/00; B32B2307/30; B32B2307/306; B32B2307/3065; B32B2315/00; B32B2315/08; B32B2315/085; B32B2457/00; B32B2457/08; H05K1/0366; H05K2201/00; H05K2201/01; H05K2201/0104; H05K2201/012; H05K2201/02; H05K2201/0275; H05K2201/0278; H05K2201/0284; H05K2201/0293; H05K2203/00; H05K2203/12; H05K2203/122; Y; Y10; Y10S; Y10S428/00; Y10S428/901; Y10S428/92; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31511; Y10T428/31515; Y10T428/31518; Y10T428/31522; Y10T428/31551; Y10T428/31627; Y10T428/31678; Y10T428/31681; Y10T428/31688; Y10T428/31703; Y10T428/31725; Y10T428/31761; Y10T428/31942; Y10T428/31949; Y10T428/31964; Y10T442/00; Y10T442/30; Y10T442/3382; Y10T442/3415; Y10T442/3431; Y10T442/3439; Y10T442/3472; Y10T442/3528; Y10T442/3569; Y10T442/3585; Y10T442/3707; Y10T442/378; Y10T442/3813
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
61 words
A porous substrate impregnated with a "B"-staged resin, the resin comprising a mixture of: (I) a brominated epoxy resin, or (II) a mixture of (A) a non-halogenated epoxy resin and (B) a flame retarding reactive additive containing bromine and phenolic hydroxyl groups, and (III) phenolic novolac oligomer curing agent having an average of over 2.5 phenolic hydroxyl groups per oligomeric unit.
Claim 2
Dependent Claim
61 words
A porous substrate impregnated with a "B"-staged resin, the resin comprising a mixture of: (I) a brominated epoxy resin, or (II) a mixture of (A) a non-halogenated epoxy resin and (B) a flame retarding reactive additive containing bromine and phenolic hydroxyl groups, and (III) phenolic novolac oligomer curing agent having an average of over 2.5 phenolic hydroxyl groups per oligomeric unit.
Claim 3
Dependent Claim
28 words
The resin impregnated substrate of claim 1, where the combined total of phenolic hydroxyl equivalents is less than or essentially equal to the combined total of epoxy equivalents.
Claim 4
Dependent Claim
49 words
The resin impregnated substrate of claim 1 where the substrate is selected from the group consisting of cellulosic paper, fibrous polyamide sheet, fibrous quartz sheet, and fibrous glass sheet and where the resin also contains a catalyst selected from the group consisting of tertiary amine, imidazole, and mixtures thereof.
Claim 5
Dependent Claim
41 words
The resin impregnated substrate of claim 1, where the phenolic novolac oligomeric unit has an average of from 2.5 to 15 phenolic hydroxyl groups per oligomeric unit, and the ratio of epoxy equivalents:phenolic hydroxyl equivalents is from 1:1 to about 1.2:1.
Claim 6
Dependent Claim
34 words
The resin impregnated substrate of claim 1, where the phenolic novolac oligomeric unit has an average of from 4 to 8 phenolic hydroxyl groups per oligomer and less than 1 weight percent free phenol.
Claim 7
Dependent Claim
45 words
The resin impregnated substrate of claim 1, where the phenolic novolac oligomer (III) has the structural formula: ##STR6## where the average of n=0 to 2, and each R is selected from CH 2 , C 2 H 4 , and C 3 H 8 .
Claim 8
Dependent Claim
15 words
The resin impregnated substrate of claim 1, where the flame retarding additive is tetrabromobisphenol A.
Claim 9
Dependent Claim
29 words
The resin impregnated substrate of claim 1 or claim 5, where the epoxy resin (II)(A) is a bisphenol A resin and the flame retarding additive (II)(B) is tetrabromobisphenol A.
Claim 10
Dependent Claim
33 words
The resin impregnated substrate of claim 1 or claim 5, where the non-halogenated epoxy resin is a mixture of bisphenol A epoxy and cycloaliphatic epoxy and the flame retarding additive is tetrabromobisphenol A.
Claim 11
Dependent Claim
20 words
The resin impregnated substrate of claim 1 or claim 5, where the non-halogenated epoxy resin is a cycloaliphatic epoxy resin.
Claim 12
Dependent Claim
25 words
A plurality of resin impregnated fibrous glass cloth substrates according to claim 1, consolidated under heat and pressure into a flame resistant, unitary bonded laminate.
Claim 13
Dependent Claim
33 words
A plurality of the resin impregnated substrates of claim 1, along with at least one metal foil outer layer, consolidated under heat and pressure into a flame resistant, unitary, bonded metal clad laminate.
Claim 14
Dependent Claim
91 words
A flame resistant, heat and pressure consolidated laminate comprising: (I) at least one metal foil outer layer, (II) a support layer comprising at least one resin impregnated sheet, bonded to the metal foil, the sheet impregnated with a cured resin reaction product admixture of: (I) a brominated epoxy resin, or (II) a mixture of (A) a non-halogenated epoxy resin and (B) a flame retarding reactive additive containing bromine and phenolic hydroxyl groups, and (III) phenolic novolac oligomer curing agent having an average of over 2.5 phenolic hydroxyl groups per oligomeric unit.
Claim 15
Dependent Claim
91 words
A flame resistant, heat and pressure consolidated laminate comprising: (I) at least one metal foil outer layer, (II) a support layer comprising at least one resin impregnated sheet, bonded to the metal foil, the sheet impregnated with a cured resin reaction product admixture of: (I) a brominated epoxy resin, or (II) a mixture of (A) a non-halogenated epoxy resin and (B) a flame retarding reactive additive containing bromine and phenolic hydroxyl groups, and (III) phenolic novolac oligomer curing agent having an average of over 2.5 phenolic hydroxyl groups per oligomeric unit.
Claim 16
Dependent Claim
77 words
The copper clad laminate of claim 13, where the sheets are selected from the group consisting of cellulosic paper, fibrous polyamide sheet, fibrous quartz sheet, woven fibrous glass cloth, unwoven fibrous glass mat, and combinations thereof, where the combined total of phenolic hydroxyl equivalents is less than or essentially equal to the combined total of epoxy equivalents, and where the resin also contains a catalyst selected from the group consisting of tertiary amine, imidazole, and mixtures thereof.
Claim 17
Dependent Claim
40 words
The copper clad laminate of claim 13, where the phenolic novolac oligomeric unit has an average of from 2.5 to 15 phenolic hydroxyl groups per oligomer and where the ratio of epoxy equivalents:phenolic hydroxyl equivalents is from 1:1 to 1.2:1.
Claim 18
Dependent Claim
55 words
The copper clad laminate of claim 13, where the substrate is selected from the group consisting of woven fibrous glass cloth, unwoven fibrous glass mat, and mixtures thereof, and the phenolic novolac oligomeric unit has an average of from 4 to 8 phenolic hydroxyl groups per oligomer and less than 1 weight percent free phenol.
Claim 19
Dependent Claim
46 words
The copper clad laminate of claim 13, where the metal foil is copper and has a conductive pattern, the flame retarding additive consists essentially of tetrabromobisphenol A, and the bromine content of the cured resin ranges from about 10 weight percent to about 20 weight percent.
Claim 20
Dependent Claim
25 words
The copper clad laminate of claim 13, where the support layer comprises a woven fibrous glass cloth core and woven fibrous glass cloth outer layers.
Claim 21
Dependent Claim
23 words
The copper clad laminate of claim 13, where the support layer comprises a cellulosic paper core and woven fibrous glass cloth outer layers.
Claim 22
Dependent Claim
23 words
The copper clad laminate of claim 13, where the support layer comprises unwoven fibrous glass mat and woven fibrous glass cloth outer layers.
Claim 23
Dependent Claim
17 words
The copper clad laminate of claim 17, where the non-halogenated epoxy resin is a bisphenol A resin.
Claim 24
Dependent Claim
22 words
The copper clad laminate of claim 17, where the non-halogenated epoxy resin is a mixture of bisphenol A epoxy and cycloaliphatic epoxy.
Claim 25
Dependent Claim
17 words
The copper clad laminate of claim 17, where the non-halogenated epoxy resin is a cycloaliphatic epoxy resin.
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) | 1988-02-26 | 1988-08-27 | 1989-02-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-02-26 | 1992-08-27 | 1993-02-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-02-26 | 1996-08-27 | 1997-02-26 | $7700.00 | Window Closed / Lapsed |