Carrier film for semi-conductor wafer processing
A carrier film includes an adhesive layer, a core layer, and a release layer. The adhesive layer includes a hydrogenated styrene block copolymer having a storage modulus (G′) of less than or equal to 400 kPa at 25° C., and a first polyolefin elastomer. The core layer includes a second polyolefin elastomer, and the release layer includes a polyolefin.
1 . A carrier film, comprising:
an adhesive layer comprising 50% to 100% by weight of a hydrogenated styrene block copolymer having a storage modulus (G′) of less than or equal to 400 kPa at 25° C. and 0% to 50% by weight of a first polyolefin elastomer, wherein a thickness of the adhesive layer is between about 1 μm and about 20 μm;
a core layer comprising a second polyolefin elastomer, wherein a thickness of the core layer is between about 40 μm and about 80 μm; and
a release layer comprising a polyolefin, wherein a thickness of the release layer is between about 1 μm and about 20 μm,
wherein the thickness of the core layer is greater than a sum of the thickness of the adhesive layer and the thickness of the release layer,
wherein the thickness of the core layer is at least 75% of a sum of the thickness of the adhesive layer, the thickness of the release layer, and the thickness of the core layer,
wherein the hydrogenated styrene block copolymer in the adhesive layer has a melt flow rate (MFR) of between about 10 g/10 minutes and about 300 g/10 minutes at 230° C. under a 2.16 kg mass, and
wherein the first polyolefin elastomer in the adhesive layer has a melt flow rate of between 1 g/10 minutes and about 100 g/10 minutes at 190° C. under a 2.16 kg mass.
2 . The carrier film according to claim 1 , wherein the hydrogenated styrene block copolymer having a storage modulus (G′) of less than or equal to 300 kPa at 25° C.
3 . The carrier film according to claim 1 , wherein the hydrogenated styrene block copolymer has a styrene content of at least 20%.
4 . The carrier film according to claim 1 , wherein the carrier film has a machine direction maximum elongation of greater than or equal to 590%.
5 . The carrier film according to claim 1 , wherein the carrier film has a machine direction tensile strength of greater than or equal to 25 MPa.
6 . The carrier film according to claim 1 , wherein the hydrogenated styrene block copolymer in the adhesive layer comprises, before hydrogenation, a polystyrene block-polydiene block polymer structure that is at least one of linear and radial.
7 . The carrier film according to claim 1 , wherein the polyolefin in the release layer comprises at least one of low density polyethylene (LDPE), linear low density polyethylene (LLDPE), high density polyethylene (HDPE), medium density polyethylene (MDPE), polypropylene (PP), random copolymer polypropylene, polypropylene impact copolymers, and metallocene linear low density polyethylene.
8 . The carrier film according to claim 1 , wherein the second polyolefin elastomer in the core layer comprises:
at least one of an ethylene-octene copolymer, an ethylene-butene copolymer, and
at least one polyolefin.
9 . The carrier film according to claim 1 , wherein the first polyolefin elastomer and the second polyolefin elastomer are the same material.
10 . The carrier film according to claim 9 , wherein the first polyolefin elastomer and the second polyolefin elastomer are ethylene-octene copolymers.
11 . The carrier film according to claim 1 , wherein the first polyolefin elastomer is an alpha-olefin copolymer.
12 . The carrier film according to claim 11 , wherein the second polyolefin elastomer is an ethylene-octene copolymer.
13 . The carrier film according to claim 1 , wherein the polyolefin in the release layer is low density polyethylene.
14 . The carrier film according to claim 13 , wherein the release layer further comprises high density polyethylene.
15 . The carrier film according to claim 1 , wherein the core layer further comprises a third polyolefin elastomer.
16 . The carrier film according to claim 15 , wherein the second polyolefin elastomer and the third polyolefin elastomer have different melt flow rates (MFRs).
17 . The carrier film according to claim 16 , wherein the core layer further comprises low density polyethylene.