Thin film and method for manufacturing the same and copper clad laminate

1. A thin film, comprising:

a polymer formed by reacting (a) p-hydroxybenzoic acid, (b) 6-hydroxy 2-naphthoic acid and (c) branched-monomer,

wherein (c) branched-monomer is

or a combination thereof, wherein R is aryl group, heteroaryl group, or cycloalkyl group, and each of R 1 is independently —OH, —NH 2 , or —COOH;

wherein a molar ratio of (a) p-hydroxybenzoic acid over (b) 6-hydroxy 2-naphthoic acid is between 50:50 and 90:10;

wherein a molar ratio of (c) branched-monomer over the sum of (a) p-hydroxybenzoic acid and (b) 6-hydroxy 2-naphthoic acid is between 0.25:100 and 0.5:100; and

wherein the polymer has an inherent viscosity of 4 dL/g to 6 dL/g.

2. The thin film as claimed in claim 1 , wherein the molar ratio of (a) p-hydroxybenzoic acid over (b) 6-hydroxy 2-naphthoic acid is between 60:40 to 80:20.

3. The thin film as claimed in claim 1 , wherein the molar ratio of (a) p-hydroxybenzoic acid over (b) 6-hydroxy 2-naphthoic acid is between 70:30 to 80:20.

4. The thin film as claimed in claim 1 , wherein (c) branched-monomer is trimesic acid.

5. The thin film as claimed in claim 1 , having a melt strength of 1.4 cN to 1.9 cN.

6. The thin film as claimed in claim 1 , having an elongation ratio of 13% to 25%.

7. The thin film as claimed in claim 1 , having a breaking strength of about 8 kgf/mm 2 to 10 kgf/mm 2 .

8. A method for manufacturing a thin film, comprising:

performing a polymerization of (a) p-hydroxybenzoic acid, (b) 6-hydroxy 2-naphthoic acid, and (c) branched-monomer;

melting the polymer to form a thin film; and

thermally treating the thin film,

wherein (c) branched-monomer is

or a combination thereof, wherein R is aryl group, heteroaryl group, or cycloalkyl group, and each of R 1 is independently —OH, —NH 2 , or —COOH;

wherein a molar ratio of (a) p-hydroxybenzoic acid over (b) 6-hydroxy 2-naphthoic acid is between 50:50 and 90:10;

wherein a molar ratio of (c) branched-monomer over the sum of (a) p-hydroxybenzoic acid and (b) 6-hydroxy 2-naphthoic acid is between 0.25:100 and 0.5:100; and

wherein the polymer has an inherent viscosity of 4 dL/g to 6 dL/g.

9. The method as claimed in claim 8 , wherein the polymerization further includes anhydride compound, and anhydride groups of the anhydride compound and sum of (a) p-hydroxybenzoic acid and (b) 6-hydroxy 2-naphthoic acid have a molar ratio of 80:100 to 120:100.

10. The method as claimed in claim 8 , wherein the polymerization is performed at a temperature of 280° C. to 330° C.

11. The method as claimed in claim 8 , wherein the step of melting the polymer is performed at a temperature of 100° C. to 160° C.

12. The method as claimed in claim 8 , wherein the step of thermally treating the thin film is performed at a temperature of 250° C. to 300° C.

13. A copper clad laminate, comprising:

a thin film; and

a copper foil attached to the thin film,

wherein the thin film comprises a polymer formed by reacting (a) p-hydroxybenzoic acid, (b) 6-hydroxy 2-naphthoic acid and (c) branched-monomer,

wherein (c) branched-monomer is

or a combination thereof, wherein R is aryl group, heteroaryl group, or cycloalkyl group, and each of R 1 is independently —OH, —NH 2 , or —COOH;

wherein a molar ratio of (a) p-hydroxybenzoic acid over (b) 6-hydroxy 2-naphthoic acid is between 50:50 and 90:10;

wherein a molar ratio of (c) branched-monomer over the sum of (a) p-hydroxybenzoic acid and (b) 6-hydroxy 2-naphthoic acid is between 0.25:100 and 0.5:100; and

wherein the polymer has an inherent viscosity of 4 dL/g to 6 dL/g.

14. The copper clad laminate as claimed in claim 13 , wherein (c) branched-monomer is trimesic acid.