Laminate, circuit board, and liquid crystal polymer film applied to the same

Patent metadata

Field	Value
Publication number	US-11840602-B2
Application number	US-202017126413-A
Country	US
Kind code	B2
Filing date	Dec 18, 2020
Priority date	Dec 23, 2019
Publication date	Dec 12, 2023
Grant date	Dec 12, 2023

Abstract

Provided are a laminate, a circuit board, and a liquid crystal polymer (LCP) film comprised therein. The laminate comprises a metal foil and an LCP film. The LCP film in the laminate has a dissipation factor before water absorption (Df′ 0 ), a dissipation factor after water absorption (Df′ 1 ), and a relative percentage difference between dissipation factors (ΔDf′), which is calculated by the following equation:
Δ ⁢ Df ′ ( % ) = ❘ "\[LeftBracketingBar]" Df 1 ′ - Df 0 ′ ❘ "\[RightBracketingBar]" Df 0 ′ × 100 ⁢ % ;
wherein ΔDf′ may be less than or equal to 16%.

By controlling ΔDf′ of the LCP film in the laminate, the insertion loss of a circuit board comprising a laminate during signal transmission in low-, medium-, and/or high-frequency bands is decreased and/or inhibited. In addition, the difference between the insertion losses of signal transmission before and after water absorption is decreased, so the laminate is suitable for high-end or outdoor high-frequency electronic products.

First claim

What is claimed is:

1. A laminate, comprising a metal foil and a liquid crystal polymer film, wherein the liquid crystal polymer film is disposed over the metal foil, and the liquid crystal polymer film in the laminate has a dissipation factor before water absorption (Df′ 0 ), a dissipation factor after water absorption (Df′ 1 ), and a relative percentage difference between dissipation factors (ΔDf′) which is calculated by the following equation:

Δ
⁢

Df
′

(
%
)

=

❘
"\[LeftBracketingBar]"

Df
1
′

-

Df
0
′

❘
"\[RightBracketingBar]"

Df
0
′

×
100
⁢
%

;

wherein the ΔDf′ is less than or equal to 16%, and
wherein the Df′ 0 and the Df′ 1 are respectively measured at 10 GHz before and after the liquid crystal polymer film in the laminate is soaked in pure water at 23° C. for 24 hours for water absorption.

2. The laminate as claimed in claim 1 , wherein the ΔDf′ of the liquid crystal polymer film in the laminate is from 5% to 16%.

3. The laminate as claimed in claim 1 , wherein the Df′ 0 of the liquid crystal polymer film in the laminate is from 0.0010 to 0.0030.

4. The laminate as claimed in claim 1 , wherein the Df′ 1 of the liquid crystal polymer film in the laminate is from 0.0011 to 0.0065.

5. The laminate as claimed in claim 1 , wherein hygroscopicity of the liquid crystal polymer film in the laminate is less than or equal to 1%.

6. The laminate as claimed in claim 2 , wherein hygroscopicity of the liquid crystal polymer film in the laminate is less than or equal to 1%.

7. The laminate as claimed in claim 1 , wherein the laminate has a peel strength before water absorption (F 0 ) and a peel strength after water absorption (F 1 ), wherein the F 0 and the F 1 are respectively measured before and after the laminate is soaked in pure water at 23° C. for 24 hours for water absorption, and wherein F 0 is from 0.85 kN/m to 0.95 kN/m and F 1 is from 0.85 kN/m to 0.95 kN/m.

8. The laminate as claimed in claim 7 , wherein the laminate has a relative percentage difference between peel strengths (ΔF), which is calculated by the following equation:

Δ
⁢

F
⁡
(
%
)

=

❘
"\[LeftBracketingBar]"

F
1

-

F
0

❘
"\[RightBracketingBar]"

F
0

×
100
⁢
%

;

wherein the ΔF is less than or equal to 5%.

9. The laminate as claimed in claim 1 , wherein the laminate further comprises another metal foil, and the liquid crystal polymer film is sandwiched between the metal foil and said another metal foil.

10. A liquid crystal polymer film, having a dissipation factor before water absorption (Df 0 ), a dissipation factor after water absorption (Df 1 ), and a relative percentage difference between dissipation factors (ΔDf) which is calculated by the following equation:

Δ
⁢

Df
⁡
(
%
)

=

❘
"\[LeftBracketingBar]"

Df
1

-

Df
0

❘
"\[RightBracketingBar]"

Df
0

×
100
⁢
%

;

wherein the ΔDf is less than or equal to 16%, and
wherein the Df 0 and the Df 1 are respectively measured at 10 GHz before and after the liquid crystal polymer film is soaked in pure water at 23° C. for 24 hours for water absorption.

11. The liquid crystal polymer film as claimed in claim 10 , wherein the ΔDf of the liquid crystal polymer film is from 5% to 15%.

12. The liquid crystal polymer film as claimed in claim 10 , wherein the Df 0 of the liquid crystal polymer film is from 0.0010 to 0.0030.

13. The liquid crystal polymer film as claimed in claim 10 , wherein the Df 1 of the liquid crystal polymer film is from 0.0011 to 0.0065.

14. A circuit board comprising the liquid crystal polymer film as claimed in claim 10 .

Assignees

• Chang Chun Plastics Co Ltd

Inventors

• Tu An-Pang
• Chen Chien-Chun
• Wu Chia-Hung

Classifications

• C08G63/065 Primary

  the hydroxy and carboxylic ester groups being bound to aromatic rings · CPC title

• B29C41/12

  Spreading-out the material on a substrate {, e.g. on the surface of a liquid} · CPC title

• B29D7/01

  Films or sheets · CPC title

• B32B15/09

  comprising polyesters · CPC title

• B32B15/20

  comprising aluminium or copper {(B32B15/016 and B32B15/017 take precedence)} · CPC title