Flexible metal laminate and preparation method of the same

1. A flexible metal laminate, comprising:

a porous polyimide resin layer comprising 30 wt % to 95 wt % of a polyimide resin, and 5 wt % to 70 wt % of fluorine-containing resin particles, and

a metal thin film layer provided on at least one side of the porous polyimide resin layer,

wherein the fluorine-containing resin particles have an average particle diameter (D50) of 0.05 μm to 9.5 μm,

wherein micropores having a diameter of 0.05 μm to 20 μm are uniformly distributed in the porous polyimide resin layer,

wherein the porous polyimide resin layer has a density of 1.2 g/cm 2 to 1.9 g/cm 2 , and

wherein the porous polyimide resin layer comprises 0.1 vol % to 2 vol % of the micropores.

2. The flexible metal laminate according to claim 1 ,

wherein the polyimide resin has a weight average molecular weight of 1000 to 500,000.

3. The flexible metal laminate according to claim 1 ,

wherein the porous polyimide resin layer has a thickness of 0.1 μm to 200 μm.

4. The flexible metal laminate according to claim 1 ,

wherein the fluorine-containing resin particles include at least one compound selected from the group consisting of polytetrafluoroethylene (PTFE), a tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), a tetrafluoroethylene-hexafluoropropylene copolymer (FEP), an ethylene-tetrafluoroethylene copolymer resin (ETFE), a tetrafluoroethylene-chlorotrifluoroethylene copolymer (TFE/CTFE), and an ethylene-chlorotrifluoroethylene resin (ECTFE).

5. The flexible metal laminate according to claim 1 ,

wherein the porous polyimide resin layer has a dielectric constant of 2.7 or less at 5 GHz.

6. The flexible metal laminate according to claim 1 ,

wherein the flexible metal laminate comprises one or more porous polyimide resin layers.

7. The flexible metal laminate according to claim 1 ,

further comprising at least one thermoplastic polyimide resin layer having a thickness of 0.1 μm to 200 μm.

8. The flexible metal laminate according to claim 1 ,

wherein the metal thin film comprises at least one metal selected from the group consisting of copper, iron, nickel, titanium, aluminum, silver, gold, and alloys of two or more of the foregoing metals.

9. The flexible metal laminate according to claim 8 ,

wherein the metal thin film has a thickness of 0.1 μm to 50 μm.

10. A method for preparing a flexible metal laminate of claim 1 , comprising the steps of: thermally curing a resin composition comprising 30 wt % to 95 wt % of a polyamic acid resin and 5 wt % to 70 wt % of fluorine-containing resin particles at a temperature range of around 280° C. to 320° C. while varying a temperature-raising rate to form a porous polyimide resin layer;

depositing a metal thin film layer on at least one side of the porous polyimide resin layer,

wherein the step of forming a porous polyimide resin layer comprises raising the temperature of the resin composition at a rate of 3° C./min to 10° C./min at a temperature range of equal to or less than 300° C., and raising the temperature at a rate of 0.2° C./min to 2° C./min at a temperature range of greater than 300° C.

11. The method according to claim 10 ,

wherein the temperature raising is completed at 340° C. to 370° C.

12. The method according to claim 10 ,

wherein the step of forming a porous polyimide resin layer further comprises coating the resin composition on a substrate to a thickness of 0.1 μm to 200 μm, before the thermal curing.

13. The method according to claim 10 ,

wherein the step of depositing a metal thin film on at least one side of the porous polyimide resin layer comprises

depositing a metal thin film comprising at least one metal selected from the group consisting of copper, iron, nickel, titanium, aluminum, silver, gold, and alloys of two or more of the foregoing metals on at least one side of the porous polyimide resin layer, while applying pressure of 500 Kgf to 3000 Kgf at a temperature of 250° C. to 450° C.