Stacked polyurethane polishing pad and method of producing the same
View Patent ↗A polishing pad has a sublayer; a top layer attached to the sublayer, the sublayer having a modulus of elasticity between 300 and 5000 psi and a compressibility of less than 30% at 73 psi, wherein the top pad has a modulus of elasticity which is greater than the modulus of elasticity of the sublayer and a compressibility which is smaller than a compressibility of the sublayer.
1. A polishing pad, comprising a sublayer; a top layer attached to said sublayer, said sublayer having a modulus of elasticity between 300 psi and 5000 psi and a compressibility of less than 30% at 73 psi, wherein said top layer has a modulus of elasticity which is greater than the modulus of elasticity of said sublayer and a compressibility which is smaller than a compressibility of said sublayer.
2. A pad as defined in claim 1 , wherein said top layer has a modulus of elasticity from 5,000 psi to 160,000 psi and a compressibility of less than 12% at 73 psi.
3. A pad according to claim 1 , wherein said sublayer is a polyurethane.
4. A pad according to claim 1 , wherein said sublayer is an acrylic polymer.
5. A pad according to claim 1 wherein said sublayer is a polyester.
6. A pad according to claim 1 wherein said sublayer is a polyether or a polyester polyurethane.
7. A pad according to claim 1 , wherein said sublayer is a polycarbonate.
8. A pad according to claim 1 , wherein said top layer contains abrasive particles selected from any of silica, alumina, ceria, titania, diamond and silicon carbide.
9. A pad according to claim 1 , wherein said top layer includes a filler.
10. A pad according to claim 1 , wherein said sublayer includes a filler.
11. A pad according to claim 1 , wherein said sublayer is a nylon.
12. A pad according to claim 1 , wherein said top layer is absent abrasive particles.
13. A polishing pad, comprising a sublayer; a top layer attached to said sublayer, said sublayer having a modulus of elasticity between 1500 psi and 3500 psi and a compressibility of between 5% and 15% at 73 psi, wherein said top layer has a modulus of elasticity which is greater than the modulus of elasticity of said sublayer and a compressibility which is smaller than a compressibility of said sublayer.
14. A pad as defined in claim 1 , wherein said top layer has a modulus of elasticity from 40,000 psi to 100,000 psi and a compressibility of between 4% and 10% at 73 psi.
15. A pad according to claim 13 , wherein said sublayer is a polyurethane.
16. A pad according to claim 13 , wherein said sublayer is an acrylic polymer.
17. A pad according to claim 13 , wherein said sublayer is a polyester.
18. A pad according to claim 13 , wherein said sublayer is a polyether or a polyester polyurethane.
19. A pad according to claim 13 , wherein said sublayer is a polycarbonate.
20. A pad according to claim 13 , wherein said top layer contains abrasive particles selected from any of silica, alumina, ceria, titania, diamond and silicon carbide.
21. A pad according to claim 13 , wherein said top layer includes a filler.
22. A pad according to claim 13 , wherein said sublayer includes a filler.
23. A pad according to claim 13 , wherein said sublayer is a nylon.
24. A pad according to claim 13 , wherein said top layer is absent abrasive particles.