System and method for producing damping polyurethane CMP pads

• US 20090062414A1
• Filed: 08/28/2007
• Published: 03/05/2009
• Est. Priority Date: 08/28/2007
• Status: Abandoned Application

• Current Assignee: Praxair Technology Incorporated (Linde Plc)
• Original Assignee: Praxair Technology Incorporated (Linde Plc)
• Inventors: Zhou, Ming, Huang, David Picheng, Moser, Timothy Dale
• Application Number:
  US11/895,829
• Publication Number:
  US 20090062414A1
• Time in Patent Office: Days
• US Class Current: 521/159
• CPC Class Codes: B24B 37/24 characterised by the composition or properties of the pad materials
• CPC Class Codes: B24D 18/00 Manufacture of grinding tools or other grinding devices, e.g. wheels, not otherwise provided for
• CPC Class Codes: C08G 18/10 Prepolymer processes involving reaction of isocyanates or isothiocyanates with compounds having active hydrogen in a first reaction step
• CPC Class Codes: C08G 18/3206 aliphatic
• CPC Class Codes: C08G 18/3808 having chlorine atoms
• CPC Class Codes: C08G 18/3868 the sulfur atom belonging to a sulfide group
• CPC Class Codes: C08G 18/4829 Polyethers containing at least three hydroxy groups C08G18/4833 - C08G18/5096 take precedence
• CPC Class Codes: C08G 18/4854 Polyethers containing oxyalkylene groups having four carbon atoms in the alkylene group
• CPC Class Codes: C08G 18/6685 with compounds of group C08G18/3225 or polyamines of C08G18/38
• CPC Class Codes: C08G 2110/0066 ≥ 150kg/m3
• CPC Class Codes: C08J 2375/08 from polyethers
• CPC Class Codes: C08J 9/122 Hydrogen, oxygen, CO2, nitrogen or noble gases

Abstract

A solid product formed by polymerizing a urethane prepolymer in the presence of a curative has a Bashore rebound that is less than about 38%. Preferably, the urethane prepolymer is an aliphatic isocyanate polyether prepolymer and the curative includes an aromatic diamine and a triol. To form a microcellular polyurethane material, the urethane prepolymer is frothed with inert gas, in the presence of a surfactant, then cured. The polyurethane can by employed to form highly damping CMP pads that have low rebound and can dissipate irregular energy and stabilize polishing to yield improved uniformity and less dishing.

Claims

1. A system for producing a CMP pad, the system comprising:

a. a froth including an inert gas, an aliphatic isocyanate polyether prepolymer, and polysiloxane-polyalkylene oxide surfactant;

b. a curative that includes an aromatic diamine; and

c. a triol.

2. The system of claim 1, wherein the triol is an alkoxylated triol.

3. The system of claim 1, wherein the triol is present in the curative.

4. The system of claim 1, wherein:

i. with respect to a theoretical amount, the curative is in the range of from 90 to 105%;

ii. based on the total weight of a curative including the aromatic diamine and the triol, the triol is present in the curative in an amount within the range of from 0.2 to 15 weight %;

or

iii. the surfactant is present in the system in an amount within the range of from 0.3 to 5 wt % based on the total weight of prepolymer and surfactant.

5. The system of claim 1, wherein the aliphatic isocyanate is selected from the group consisting of hydrogenated methylene diphenyl diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate and any combination thereof.

6. The system of claim 1, wherein, a solid product formed by curing the aliphatic isocyanate polyether prepolymer in the presence of the curative has a Bashore rebound less than 38%.

7. A method for producing a CMP pad, the method comprising:

a. frothing an aliphatic isocyanate polyether prepolymer with an inert gas, in the presence of a polysiloxane-polyalkyleneoxide surfactant, to form a froth; and

b. polymerizing the froth in the presence of an aromatic diamine and a triol.

8. The method of claim 7, wherein the triol is an alkoxylated triol.

9. The method of claim 7, wherein:

i. with respect to a theoretical amount, a curative that includes the aromatic diamine and the triol is in the range of from 90 to 105%;

ii. based on the total weight of a curative including the aromatic diamine and the triol, the triol is present in the curative in an amount within the range of from 0.2 to 15 weight %;

or

iii. the surfactant is present in an amount within the range of from 0.3 to 5 wt % based on the total weight of prepolymer and surfactant.

10. The method of claim 7, wherein the aliphatic isocyanate is selected from the group consisting of hydrogenated methylene diphenyl diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate and any combination thereof.

11. The method of claim 7, wherein, a solid product formed by curing the aliphatic isocyanate polyether prepolymer in the presence of a curative that includes the aromatic diamine and the triol has a Bashore rebound that is less than 38%.

12. The method of claim 7, wherein the froth is cured at a temperature within the range of from about 50 to about 250°

F.

13. A method for producing a microcellular polyurethane material, the method comprising:

a. frothing a urethane prepolymer to form a froth; and

b. curing the froth in the presence of a curative, thereby producing the microcellular polyurethane, wherein, a solid product formed by polymerizing the urethane prepolymer in the presence of the curative has a Bashore rebound less than 38%.

14. The method of claim 13, wherein the curative includes an aromatic diamine and a triol.

15. The method of claim 13, wherein the urethane prepolymer is an aliphatic isocyanate polyether prepolymer or a polyester urethane prepolymer.

16. The method of claim 13, wherein the urethane prepolymer is frothed with dry air or with an inert gas selected from the group consisting of nitrogen, helium, argon, and any combination thereof.

17. The method of claim 13, wherein the urethane prepolymer is frothed in the presence of a surfactant.

18. The method of claim 13, wherein the froth is cured at a temperature within the range of from about 50 to about 250°

F.

19. The method of claim 13, further comprising post-curing the product of step (c).

20. The method of claim 13, wherein the solid product has a hardness within the range of from 30 to 85 D and the microcellular polyurethane material has a hardness in the range of from 30 D to 80 D.

21. The method of claim 13, wherein the microcellular polyurethane material has a density in the range of from 0.6 to 1.0.

22. The method of claim 13, wherein the microcellular polyurethane material has a mean pore size is in the range of from 2 to 200 μ

m or a pore area % in the range of from 10 to 50%.

23. A CMP pad comprising the microcellular polyurethane material produced by the method of claim 13.

24. A system for producing a microcellular polyurethane, the system comprising:

a urethane prepolymer and a curative, wherein, when combined under polymerization conditions, the urethane prepolymer and the curative form a solid product having a Bashore rebound that is less than 38%.

25. The system of claim 24, wherein the solid product has a hardness within the range of from 30 to 85 D and the microcellular polyurethane has a hardness within the range of from 30 to 80 D.