Liquid crystal polymer film and uses of the same

Abstract

This invention relates to a liquid crystal polymer film with low dielectric constant and low dielectric loss factor, a metal-clad laminate comprising the liquid crystal polymer film, and a printed circuit board, wherein the liquid crystal polymer film has a heat of fusion of 0.50 joules / gram to 1.10 joules / gram, and has a first surface and a second surface opposite to the first surface, wherein the ratio of the root mean square height of the first surface to the average roughness (Sq / Sa) is 1.20 to 2.30.

Claims

1. A liquid crystal polymer film having a heat of fusion of 0.50 joules / gram to 1.10 joules / gram, and having a first surface and a second surface opposite to the first surface, wherein the ratio (Sq / Sa) of the root mean square deviation (Sq) of the first surface to the arithmetic mean height (Sa) is 1.20 to 2.30, wherein Sq and Sa are defined according to ISO 25178-2:2012, and the units are both micrometers.

2. The liquid crystal polymer film as claimed in claim 1, wherein the Sq series of the first surface is greater than or equal to 0.04 micrometers.

3. The liquid crystal polymer film as claimed in claim 2, wherein the Sa of the first surface is less than or equal to 0.30 micrometers.

4. The liquid crystal polymer film as claimed in claim 1, wherein the ratio of Sq to Sa (Sq / Sa) of the second surface is 1.20 to 2.30, wherein Sq and Sa are defined according to ISO 25178-2:2012, and the units are both micrometers.

5. The liquid crystal polymer film as claimed in claim 4, wherein the Sq of the second surface is greater than or equal to 0.04 micrometers.

6. The liquid crystal polymer film as claimed in claim 5, wherein the Sa of the second surface is less than or equal to 0.30 micrometers.

7. The liquid crystal polymer film as described in any one of claims 1 to 6, wherein the heat of fusion is measured under the following conditions: using a differential scanning calorimeter (DSC) to heat from 80ºC to 400ºC at a rate of 10ºC per minute at 1 atm.

8. The liquid crystal polymer film as described in any one of claims 1 to 6, having a melting point of 270ºC to 330ºC.

9. The liquid crystal polymer film as described in claim 8, whose spectrum obtained by differential scanning calorimetry analysis shows a single-peak distribution.

10. A metal-clad laminate comprising a liquid crystal polymer film as described in any one of claims 1 to 9, and a first metal layer disposed on a first surface of the liquid crystal polymer film.

11. The metal-clad laminate as described in claim 10, further comprising a second metal layer disposed on a second surface of the liquid crystal polymer film.

12. The metal-clad laminate as described in claim 10 or 11, wherein the ten-point mean roughness (Rz) of the first metal layer and / or the second metal layer is less than or equal to 2.5 micrometers.

13. A printed circuit board made from the metal-clad laminate structure described in any one of claims 10 to 12.