Fine pitch electrical connector and a thermoplastic composition for use therein

Patent metadata

Field	Value
Publication number	US-9353263-B2
Application number	US-201213675104-A
Country	US
Kind code	B2
Filing date	Nov 13, 2012
Priority date	Nov 15, 2011
Publication date	May 31, 2016
Grant date	May 31, 2016

Abstract

A thermoplastic composition for use in a fine pitch electrical connector is provided. The thermoplastic composition contains a liquid crystalline polymer and a plurality of fibers. The volume average length of the fibers in the thermoplastic composition is selectively controlled according to the present invention so that it is within a certain range, such as from about 80 to about 250 micrometers. The fibers also have a narrow length distribution. That is, at least about 70% by volume of the fibers have a length within a certain range. Through the use of a liquid crystalline polymer and fibers of a certain weight average length and narrow length distribution, the present inventors have discovered that the resulting thermoplastic composition is able to achieve a desirable combination of strength and flowability, which enables it to be uniquely suited for the walls of a fine pitch connector.

First claim

What is claimed is:

1. An electrical connector that comprises at least two opposing walls between which a passageway is defined for receiving a contact pin, wherein the walls have a width of about 500 micrometers or less, the walls being formed from a thermoplastic composition that comprises from about 20 wt. % to about 90 wt. % of at least one melt-processed thermotropic liquid crystalline polymer and from about 2 wt. % to about 40 wt. % of fibers, wherein the ratio of the width of at least one of the walls to the volume average length of the fibers is from about 0.8 to about 3.2, and wherein the fibers have a volume average length of from about 80 to about 250 micrometers and wherein at least about 70% by volume of the fibers have a length of from about 80 to about 250 micrometers,
wherein the at least one melt-processed thermotropic liquid crystalline polymer is formed by melt processing a first thermotropic liquid crystalline polymer in the presence of a flow modifier comprising a functional compound that includes an aromatic diol, hydrate, aromatic dicarboxylic acid, or a combination thereof.

2. The electrical connector of claim 1 , wherein the walls have a width of from about 200 to about 400 micrometers.

3. The electrical connector of claim 1 , wherein the ratio of the width of at least one of the walls to the volume average length of the fibers is from about 1.2 to about 2.9.

4. The electrical connector of claim 1 , wherein the fibers have a volume average length of from about 110 to about 180 micrometers.

5. The electrical connector of claim 4 , wherein at least about 70% by volume of the fibers have a length of from about 110 to about 180 micrometers.

6. The electrical connector of claim 1 , wherein at least about 90% by volume of the fibers have a length of from about 80 to about 250 micrometers.

7. The electrical connector of claim 1 , wherein the fibers are glass fibers.

8. The electrical connector of claim 1 , wherein the thermotropic crystalline polymer contains repeating units derived from 4-hydroxybenzoic acid, 2,6-hydroxynaphtoic acid, or both.

9. The electrical connector of claim 8 , wherein the polymer further contains repeating units derived from terephthalic acid, isophthalic acid, hydroquinone, 4,4-biphenol, or a combination thereof.

10. The electrical connector of claim 1 , wherein the thermoplastic composition further comprises at least one mineral filler.

11. The electrical connector of claim 1 , wherein the thermoplastic composition has a melt viscosity of from about 0.5 to about 100 Pa-s, as determined at a shear rate of 1000 seconds −1 and temperature of 350° C. in accordance with ASTM Test No. 1238-70.

12. A thermoplastic composition comprising from about 20 wt. % to about 90 wt. % of at least one melt-processed thermotropic liquid crystalline polymer, from about 2 wt. % to about 40 wt. % of glass fibers, and from about 1 wt. % to about 40 wt. % of at least one mineral filler, wherein the glass fibers have a volume average length of from about 100 to about 200 micrometers and wherein at least about 70% by volume of the fibers have a length of from about 100 to about 200 micrometers,
wherein the at least one melt-processed thermotropic liquid crystalline polymer is formed by melt processing a first thermotropic liquid crystalline polymer in the presence of a flow modifier comprising a functional compound that includes an aromatic diol, hydrate, aromatic dicarboxylic acid, or a combination thereof.

13. The composition of claim 12 , wherein the fibers have a volume average length of from about 110 to about 180 micrometers.

14. The composition of claim 13 , wherein at least about 70% by volume of the fibers have a length of from about 110 to about 180 micrometers.

15. The composition of claim 12 wherein at least about 90% by volume of the fibers have a length of from about 100 to about 200 micrometers.

16. The composition of claim 12 , wherein the thermotropic crystalline polymer contains repeating units derived from 4-hydroxybenzoic acid, 2,6-hydroxynaphtoic acid, or both.

17. The composition of claim 16 , wherein the polymer further contains repeating units derived from terephthalic acid, isophthalic acid, hydroquinone, 4,4-biphenol, or a combination thereof.

18. The composition of claim 12 , wherein the thermoplastic composition has a melt viscosity of from about 0.5 to about 100 Pa-s, as determined at a shear rate of 1000 seconds −1 and temperature of 350° C. in accordance with ASTM Test No. 1238-70.

19. A molded housing that comprises the thermoplastic composition of claim 12 .

20. The molded housing of claim 19 , wherein the housing defines opposing walls between which a passageway is defined, the walls having a width of about 500 micrometers or less.

21. The thermoplastic composition of claim 12 , wherein the composition includes an aromatic diol.

22. The thermoplastic composition of claim 12 , wherein the composition includes an aromatic dicarboxylic acid.

23. The thermoplastic composition of claim 12 , wherein the composition includes a hydrate.

24. The thermoplastic composition of claim 12 , wherein the composition includes 4,4′-biphenol, 2,6-napthalenedicarboxylic acid, and alumina trihydrate.

25. The electrical connector of claim 1 , wherein the thermotropic crystalline polymer is obtained from an aromatic hydroxycarboxylic acid, aromatic dicarboxylic acid, aromatic diol, aromatic aminocarboxylic acid, aromatic amine optionally having a phenolic hydroxy group, aromatic diamine optionally having phenolic hydroxy group, or combinations thereof.

26. The thermoplastic composition of claim 12 , wherein the thermotropic crystalline polymer is obtained from an aromatic hydroxycarboxylic acid, aromatic dicarboxylic acid, aromatic diol, aromatic aminocarboxylic acid, aromatic amine optionally having a phenolic hydroxy group, aromatic diamine optionally having phenolic hydroxy group, or combinations thereof.

Assignees

• Ticona Llc

Inventors

• Kim Young Shin
• Zhao Xinyu
• Grenci Joseph J

Classifications

• H01R43/18

  for manufacturing bases or cases for contact members · CPC title

• C08K13/04

  Ingredients characterised by their shape and organic or inorganic ingredients · CPC title

• H01B3/423 Primary

  Linear aromatic polyesters · CPC title

• H01R12/75

  connecting to cables except for flat or ribbon cables · CPC title

• C08K7/14

  Glass · CPC title