Aramid paper suitable for use in electronic applications

Patent metadata

Field	Value
Publication number	US-11111632-B2
Application number	US-201716464534-A
Country	US
Kind code	B2
Filing date	Nov 27, 2017
Priority date	Nov 30, 2016
Publication date	Sep 7, 2021
Grant date	Sep 7, 2021

Abstract

An aramid paper suitable for use in electronic applications which has a density of 0.20-0.65 g/cm3 and a grammage of 30-280 g/m2, which paper comprises 10-40 wt. % of aramid shortcut with a linear density of 2.6 dtex or lower and a length of 0.5-25 mm and 10-90 wt. % of aramid fibrid, wherein the aramid shortcut comprises at least 70 wt. % para-aramid shortcut and the aramid fibrid including at least 70 wt. % para-aramid fibrid. It has been found that the use of a paper with the above properties in electronic applications ensures a low CTE in combination with good homogeneity and a good dimensional stability resulting from good resin adhesion and penetration. Use of the aramid paper in a composite sheet including at least one layer of aramid paper and a resin, or in a substrate board for electronic applications.

First claim

The invention claimed is:

1. Aramid paper
wherein the aramid paper is suitable for use as substrate in electronic applications,
wherein the aramid paper has a density in the range of 0.20-0.65 g/cm 3 and a grammage in the range of 30-280 g/m 2 ,
wherein the aramid paper comprises
10-40 wt. % of aramid shortcut with a linear density of 2.6 dtex or lower and a length of 0.5-25 mm, wherein the aramid shortcut comprises at least 70 wt. % para-aramid shortcut,
10-80 wt. % of aramid fibrid, wherein the aramid fibrid comprises at least 70 wt. % para-aramid fibrid, and
10-80 wt. % of aramid pulp, and

wherein the aramid paper has a surface resistivity of at least 1×10 6 Ohms/square.

2. Aramid paper according to claim 1 , wherein the aramid paper has a density in the range of 0.30-0.65 g/cm 3 .

3. Aramid paper according to claim 1 , wherein the aramid paper comprises at least 80 wt. % of aramid.

4. Aramid paper according to claim 1 , wherein the aramid fibrid, the aramid shortcut and the aramid pulp each comprise at least 85 wt. % of para-aramid.

5. Aramid paper according to claim 1 , wherein the aramid paper comprises at least 20 wt. % of aramid fibrid and at most 80 wt. % of aramid fibrid.

6. Aramid paper according to claim 1 , wherein the aramid paper comprises 10-40 wt. % of aramid shortcut in combination with 80-60 wt. % of aramid fibrid.

7. Aramid paper according to claim 1 , wherein the aramid paper comprises 10-40 wt. % of aramid shortcut in combination with 20-80 wt. % aramid fibrid and 10-40 wt. % of aramid pulp.

8. Aramid paper according to claim 1 , wherein the aramid pulp is para-aramid pulp.

9. Composite sheet comprising at least one layer of the aramid paper according to claim 1 impregnated with a resin.

10. Laminate comprising a composite sheet according to claim 9 wherein a copper layer is present on at least one side of the composite sheet.

11. Printed circuit board comprising a laminate according to claim 10 , wherein electrical components are affixed to the copper layer.

12. Solar cell provided with a composite sheet according to claim 9 as backing.

Assignees

• Teijin Aramid Bv

Inventors

• Hendriks Antonius
• López-Lorenzo Mónica
• Tiecken Jan-Cees
• Diedering Frank

Classifications

• H10F77/00

  Constructional details of devices covered by this subclass (constructional details of integrated devices, or assemblies of multiple devices, comprising at least one element in which radiation controls the flow of current H10F39/00) · CPC title

• B32B15/00 Primary

  Layered products comprising {a layer of} metal · CPC title

• D21H17/48

  with phenols · CPC title

• D04H1/549

  Polyamides · CPC title

• D04H1/4342

  Aromatic polyamides · CPC title