Multilayer film for electronic circuitry applications

1. A multilayer film comprising:

a first outer layer comprising a first thermoplastic polyimide consisting of a polyimide composition derived from:

an aromatic dianhydride; and

an aromatic diamine selected from the group consisting of m-phenylenediamine, trifluoromethyl-2,4-diaminobenzene, trifluoromethyl-3,5-diaminobenzene, 2,2-bis-(4-aminophenyl) propane, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenyl sulfide, 4,4′-diaminodiphenyl sulfone, 3,3′-diaminodiphenyl sulfone, bis-(4-(4-aminophenoxy)phenyl sulfone, 4,4′-bis-(aminophenoxy)biphenyl, 3,4′-diaminodiphenyl ether, 4,4′-diaminobenzophenone, 4,4′-isopropylidenedianiline, 2,2′-bis-(3-aminophenyl)propane, N,N-bis-(4-aminophenyl)-n-butylamine, N,N-bis-(4-aminophenyl) methylamine, m-amino benzoyl-p-amino anilide, N,N-bis-(4-aminophenyl) aniline, 2,4-diaminotoluene, 2,6-diaminotoluene, 2,4-diamine-5-chlorotoluene, 2,4-diamine-6-chlorotoluene, 2,4-bis-(beta-amino-t-butyl) toluene, bis-(p-beta-amino-t-butyl phenyl) ether, p-bis-2-(2-methyl-4-aminopentyl) benzene, m-xylylene diamine, p-xylylene diamine, 1,2-bis-(4-aminophenoxy)benzene, 1,3-bis-(4-aminophenoxy) benzene, 1,2-bis-(3-aminophenoxy)benzene, 1,3-bis-(3-aminophenoxy) benzene, 1-(4-aminophenoxy)-3-(3-aminophenoxy) benzene, 1,4-bis-(4-aminophenoxy) benzene, 1,4-bis-(3-aminophenoxy) benzene, 1-(4-aminophenoxy)-4-(3-aminophenoxy) benzene, 2,2-bis-(4-[4-aminophenoxy]phenyl) propane, 2,2′-bis-(4-aminophenyl)-hexafluoro propane, 2,2′-bis-(4-phenoxy aniline) isopropylidene, 4,4′-diamino-2,2′-trifluoromethyl diphenyloxide, 3,3′-diamino-5,5′-trifluoromethyl diphenyloxide, 4,4′-trifluoromethyl-2,2′-diaminobiphenyl, 2,4,6-trimethyl-1,3-diaminobenzene, 4,4′-oxy-bis-[2-trifluoromethyl)benzene amine], 4,4′-oxy-bis-[3-trifluoromethyl)benzene amine], 4,4′-thio-bis-[(2-trifluoromethyl)benzene-amine], 4,4′-thiobis[(3-trifluoromethyl)benzene amine], 4,4′-sulfoxyl-bis-[(2-trifluoromethyl)benzene amine, 4,4′-sulfoxyl-bis-[(3-trifluoromethyl)benzene amine], and 4,4′-keto-bis-[(2-trifluoromethyl)benzene amine] and mixtures thereof;

a core layer comprising a polyimide consisting of a polyimide composition derived from an aromatic dianhydride comprising a first aromatic dianhydride comprising 3,3′,4,4′-biphenyl tetracarboxylic dianhydride and an aromatic diamine selected from the group consisting of p-phenylenediamine, 2,5-dimethyl-1,4-diaminobenzene, 2,5-dimethyl-1,4-phenylenediamine, 4,4′-diaminobiphenyl, 4,4′-diaminobenzophenone, 4,4′-diaminodiphenyl ether, 1,5-diaminonaphthalene, 3,3′-dimethyl-4,4′-diaminobiphenyl, 4-aminophenyl-3-aminobenzoate, 2,5-diaminotoluene, 2,2′-bis(trifluoromethyl) benzidine, 2,4,6-trimethyl-1,3-diaminobenzene, and mixtures thereof; and

a second outer layer comprising a second thermoplastic polyimide consisting of a polyimide composition derived from:

an aromatic dianhydride; and

an aromatic diamine selected from the group consisting of m-phenylenediamine, trifluoromethyl-2,4-diaminobenzene, trifluoromethyl-3,5-diaminobenzene, 2,2-bis-(4-aminophenyl) propane, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenyl sulfide, 4,4′-diaminodiphenyl sulfone, 3,3′-diaminodiphenyl sulfone, bis-(4-(4-aminophenoxy)phenyl sulfone, 4,4′-bis-(aminophenoxy)biphenyl, 3,4′-diaminodiphenyl ether, 4,4′-diaminobenzophenone, 4,4′-isopropylidenedianiline, 2,2′-bis-(3-aminophenyl)propane, N,N-bis-(4-aminophenyl)-n-butylamine, N,N-bis-(4-aminophenyl) methylamine, m-amino benzoyl-p-amino anilide, N,N-bis-(4-aminophenyl) aniline, 2,4-diaminotoluene, 2,6-diaminotoluene, 2,4-diamine-5-chlorotoluene, 2,4-diamine-6-chlorotoluene, 2,4-bis-(beta-amino-t-butyl) toluene, bis-(p-beta-amino-t-butyl phenyl) ether, p-bis-2-(2-methyl-4-aminopentyl) benzene, m-xylylene diamine, p-xylylene diamine, 1,2-bis-(4-aminophenoxy)benzene, 1,3-bis-(4-aminophenoxy) benzene, 1,2-bis-(3-aminophenoxy)benzene, 1,3-bis-(3-aminophenoxy) benzene, 1-(4-aminophenoxy)-3-(3-aminophenoxy) benzene, 1,4-bis-(4-aminophenoxy) benzene, 1,4-bis-(3-aminophenoxy) benzene, 1-(4-aminophenoxy)-4-(3-aminophenoxy) benzene, 2,2-bis-(4-[4-aminophenoxy]phenyl) propane, 2,2′-bis-(4-aminophenyl)-hexafluoro propane, 2,2′-bis-(4-phenoxy aniline) isopropylidene, 4,4′-diamino-2,2′-trifluoromethyl diphenyloxide, 3,3′-diamino-5,5′-trifluoromethyl diphenyloxide, 4,4′-trifluoromethyl-2,2′-diaminobiphenyl, 2,4,6-trimethyl-1,3-diaminobenzene, 4,4′-oxy-bis-[2-trifluoromethyl)benzene amine], 4,4′-oxy-bis-[3-trifluoromethyl)benzene amine], 4,4′-thio-bis-[(2-trifluoromethyl)benzene-amine], 4,4′-thiobis[(3-trifluoromethyl)benzene amine], 4,4′-sulfoxyl-bis-[(2-trifluoromethyl)benzene amine, 4,4′-sulfoxyl-bis-[(3-trifluoromethyl)benzene amine], and 4,4′-keto-bis-[(2-trifluoromethyl)benzene amine] and mixtures thereof; wherein:

the multilayer film has a total thickness in a range of from 5 to 150 μm, a transmission of at least 50% and a haze of less than 30%;

a thickness of the core layer is in a range of from 35 to 73% of the total thickness of the multilayer film; and

a minimum peel strength for at least one of the first and second outer layers, when adhered to copper foil and tested following ASTM method IPC-TM-650, method No. 2.4.9B, is greater than 0.9 kgf/cm (0.88 N/mm).

2. The multilayer film of claim 1 , wherein:

the aromatic dianhydride of the first thermoplastic polyimide is selected from the group consisting of 4,4′-oxydiphthalic dianhydride, pyromellitic dianhydride, 3,3′,4,4′-biphenyl tetracarboxylic dianhydride, 3,3′,4,4′-benzophenone tetracarboxylic dianhydride and mixtures thereof; and

the aromatic diamine of the first thermoplastic polyimide is selected from the group consisting of 1,3-bis(4-aminophenxoxy) benzene, 2,2-bis-(4-[4-aminophenoxy]phenyl) propane and mixtures thereof.

3. The multilayer film of claim 2 , wherein:

the aromatic dianhydride of the first thermoplastic polyimide is a mixture of pyromellitic dianhydride and 4,4′-oxydiphthalic dianhydride; and

the aromatic diamine of the first thermoplastic polyimide is 1,3-bis(4-aminophenoxy) benzene.

4. The multilayer film of claim 1 , wherein:

the aromatic dianhydride of the second thermoplastic polyimide is selected from the group consisting of 4,4′-oxydiphthalic dianhydride, pyromellitic dianhydride, 3,3′,4,4′-biphenyl tetracarboxylic dianhydride, 3,3′,4,4′-benzophenone tetracarboxylic dianhydride and mixtures thereof; and

the aromatic diamine of the second thermoplastic polyimide is selected from the group consisting of 1,3-bis(4-aminophenxoxy) benzene, hexamethylene diamine and mixtures thereof.

5. The multilayer film of claim 4 , wherein:

the aromatic dianhydride of the second thermoplastic polyimide is a mixture of pyromellitic dianhydride and 4,4′-oxydiphthalic dianhydride; and

the aromatic diamine of the second thermoplastic polyimide is 1,3-bis(4-aminophenoxy) benzene.

6. The multilayer film of claim 1 , wherein the polyimide compositions of the first and second thermoplastic polyimides are the same.

7. The multilayer film of claim 1 , wherein the aromatic dianhydride of the core layer further comprises a second aromatic dianhydride.

8. The multilayer film of claim 7 , wherein the second aromatic dianhydride is selected from the group consisting of 4,4′-oxydiphthalic dianhydride, pyromellitic dianhydride, 3,3′,4,4′-benzophenone tetracarboxylic dianhydride, bisphenol A dianhydride, 1,2,5,6-naphthalene tetracarboxylic dianhydride, 1,4,5,8-naphthalene tetracarboxylic dianhydride, and 2,3,6,7-naphthalene tetracarboxylic dianhydride.

9. The multilayer film of claim 1 , wherein the aromatic diamine of the core layer is p-phenylenediamine.

10. The multilayer film of claim 1 , wherein the aromatic diamine of the core layer is a mixture of p-phenylenediamine and an aromatic diamine selected from the group consisting of 4,4′-diaminodiphenyl ether, 3,4′-diaminodiphenyl ether, 2,2′-bis(trifluoromethyl) benzidine, m-phenylenediamine and 4,4′-diaminodiphenylmethane.

11. The multilayer film of claim 1 , wherein the polyimide composition of the core layer comprises a mixture of aromatic dianhydrides and a mixture of aromatic diamines.

12. The multilayer film of claim 1 , wherein the polyimide composition of the core layer comprises at least 80 mole percent 3,3′,4,4′-biphenyl tetracarboxylic dianhydride based on a total dianhydride content of the polyimide and at least 80 mole percent p-phenylenediamine based on a total diamine content of the polyimide.

13. The multilayer film of claim 1 , wherein the multilayer film has a coefficient of thermal expansion of less than 25 μm/(meter-° C.) over a temperature in the range of from 50 to 400° C.

14. The multilayer film of claim 1 , wherein the first thermoplastic polyimide and the second thermoplastic polyimide each have a T g in the range of from 150 to 320° C.

15. The multilayer film of claim 1 , wherein the total thickness of the multilayer film is in a range of from 5 to 75 μm.

16. The multilayer film of claim 1 , wherein the minimum peel strength of each of the first and second outer layers is greater than 0.9 kgf/cm (0.88 N/mm).

17. The multilayer film of claim 1 , wherein the thickness of the core layer is in the range of from 55 to 73% of the total thickness of the multilayer film.

18. A metal-clad laminate comprising the multilayer film of claim 1 and a first metal layer adhered to an outer surface of the first outer layer of the multilayer film.

19. The metal-clad laminate of claim 18 , further comprising a second metal layer adhered to an outer surface of the second outer layer of the multilayer film.