Back-grinding tape

Abstract

A back grinding tape including a hard coating layer, an intermediate layer including a polyurethane-based resin, and an adhesive layer provided has an excellent water resistance, thus easily protecting patterns, and has an excellent adhesion between each layer, and thus each layer is not separated in the process of removing the tape, such that the back grinding tape is suitable for a back grinding process.

Claims

1. A back grinding tape comprising: a hard coating layer; an intermediate layer comprising a polyurethane-based resin; and an adhesive layer, wherein a sum of polar energy values of the hard coating layer and the intermediate layer calculated according to Mathematical Equation 1 is 13 dyne/cm to 17 dyne/cm, and the polar energy value of the intermediate layer calculated according to the Mathematical Equation 1 is 3.5 dyne/cm or less:
Polar Energy (dyne/cm)=Surface free energy (dyne/cm)−Dispersion (dyne/cm)  [Mathematical Equation 1] wherein, in the Equation, the surface free energy and the dispersion are measured using water and diiodomethane (CH.sub.2I.sub.2) solutions according to a Wu-harmonic method, wherein a thickness of the hard coating layer is 0.1 μm to 5 μm, and wherein the hard coating layer, the intermediate layer and the adhesive layer are sequentially stacked.

2. The back grinding tape according to claim 1, wherein the sum of the polar energy values of the hard coating layer and the intermediate layer is 13.3 dyne/cm to 16 dyne/cm, and the polar energy value of the intermediate layer is 3.0 dyne/cm or less.

3. The back grinding tape according to claim 1, wherein a thickness of the intermediate layer is 50 μm to 500 μm.

4. The back grinding tape according to claim 1, wherein a thickness of the adhesive layer is 0.5 μm to 60 μm.

5. The back grinding tape according to claim 1, wherein the hard coating layer comprises one or more selected from the group consisting of a polyester-based compound, an acryl-based compound, a polyurethane-based compound, a cellulose acetate-based compound, and a polycaprolactone-based compound.

6. The back grinding tape according to claim 1, wherein the intermediate layer is formed by curing a composition comprising the polyurethane-based resin, acrylate-based monomers, a curing agent, and a photoinitiator.

7. The back grinding tape according to claim 6, wherein the acrylate-based monomers include hydroxy group-containing acrylate-based monomers.

8. The back grinding tape according to claim 7, wherein the hydroxy group-containing acrylate-based monomers are included in a content of 1 to 25 wt %, based on total content of the composition.

9. The back grinding tape according to claim 1, wherein the adhesive layer is formed of a composition for forming an adhesive layer comprising an acrylate-based thermosetting resin, a curing agent, a photoinitiator, and a solvent.

10. A wafer pattern, wherein the wafer pattern is attached to the back-grinding tape of claim 1.

11. The back grinding tape according to claim 1, wherein the back grinding tape is used in a back grinding process of a semiconductor wafer.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) FIG. 1 shows the cross-sectional structure of a back grinding tape (10) according to one embodiment of the present invention.

DETAILED DESCRIPTION OF THE EMBODIMENTS

(2) Hereinafter, preferable examples are presented for better understanding of the invention. However, the following examples are presented only as illustrations of the invention, and the scope of the present invention is not limited thereby.

Preparation Example 1: A Composition for Forming a Hard Coating Layer

Preparation Example 1-1: A Composition for Forming a Hard Coating Layer

(3) 40 g of PS1000 (including a polycaprolactone-based compound) from Cho Kwang Paint, 8 g of PS1000 blue, and 7 g of a diluent solvent of methylethylketone (MEK) were mixed to prepare a composition for forming a hard coating layer (1-1).

Preparation Example 1-2: A Composition for Forming a Hard Coating Layer

(4) 50 g of CAP varnish (including a cellulose acetate-based compound) of Sam Young Ink, and 50 g of a diluent solvent of methylethylketone (MEK) were mixed to prepare a composition for forming a hard coating layer (1-2).

Preparation Example 1-3: A Composition for Forming a Hard Coating Layer

(5) 30 g of A-PET 328 varnish (including a polyester-based compound) of Sam Young Ink, 10 g of acrylic blue (T-6), 20 g of methylethylketone (MEK), and 0.15 g of LP.SUPER curing agent of Sam Young Ink were mixed to prepare a composition for forming a hard coating layer (1-3).

Preparation Example 1-4: A Composition for Forming a Hard Coating Layer

(6) 6 g of polymer silicone resin KS-3650 of Shin-Etsu silicone, 0.1 g of a platinum catalyst PL-50T, 50 g of a solvent of toluene, and 50 g of methylethylketone (MEK) were mixed to prepare a composition for forming a hard coating layer (1-4).

Preparation Example 2: A Composition for Forming an Intermediate Layer Including Polyurethane-Based Resin

Preparation Example 2-1: A Composition for Forming an Intermediate Layer Including Polyurethane-Based Resin

(7) 21 g of polycarbonate diol, 3 g of isophorone diisocyanate (IPDI), and 21 g of diluent monomers of cyclohexyl methacrylate (CHMA) were mixed to progress a polymerization reaction, and then the end was capped using 1 g of 1-hydroxyethyl methacrylate (1-HEMA) to synthesize a polyurethane oligomer having a weight average molecular weight of 30,000 g/mol.

(8) Next, 25 g of the above-prepared polyurethane oligomer, 21 g of a remaining diluent monomer cyclohexyl methacrylate (CHMA), 22 g of o-phenylphenol EO acrylate (OPPEA), 32 g of hydroxyethyl acrylate (HEA), 2 g of a curing agent of 1,6-hexanediol diacrylate (HDDA), and 0.5 g of a photoinitiator Irgacure 651 were mixed to prepared a composition for forming an intermediate layer (2-1).

Preparation Example 2-2: A Composition for Forming an Intermediate Layer Including Polyurethane-Based Resin

(9) 21 g of polycarbonate diol, 3 g of isophorone diisocyanate (IPDI), and 21 g of diluent monomers of trimethylcyclohexyl methacrylate (TMCHA) were mixed to progress a polymerization reaction, and then the end was capped using 1 g of 1-hydroxyethyl methacrylate (1-HEMA) to synthesize a polyurethane oligomer having a weight average molecular weight of 30,000 g/mol.

(10) Next, 25 g of the above-prepared polyurethane oligomer, 21 g of a remaining diluent monomer trimethylcyclohexyl methacrylate (TMCHA), 29 g of o-phenylphenol EO acrylate (OPPEA), 10 g of isobornyl acrylate (IBOA), 10 g of hydroxyethyl acrylate (HEA), 5 g of 2-hydroxy-3-phenylphenoxypropyl acrylate, 2 g of a curing agent of 1,6-hexanediol diacrylate (HDDA), and 0.5 g of a photoinitiator Irgacure 651 were mixed to prepared a composition for forming an intermediate layer (2-2).

Preparation Example 2-3: A Composition for Forming an Intermediate Layer Including Polyurethane-Based Resin

(11) 21 g of polycarbonate diol, 3 g of isophorone diisocyanate (IPDI), and 33 g of diluent monomers of isobornyl acrylate (IBOA) were mixed to progress a polymerization reaction, and then the end was capped using 1 g of 1-hydroxyethyl methacrylate (1-HEMA) to synthesize a polyurethane oligomer having a weight average molecular weight of 30,000 g/mol.

(12) Next, 25 g of the above-prepared polyurethane oligomer, 33 g of a remaining diluent monomer trimethylcyclohexyl methacrylate (TMCHA), 22 g of o-phenylphenol EO acrylate (OPPEA), 15 g of hydroxyethyl acrylate (HEA), 5 g of hydroxyethyl acrylate (HEA), 2 g of a curing agent 1,6-hexanediol diacrylate (HDDA), and 0.5 g of a photoinitiator Irgacure 651 were mixed to prepare a composition for forming an intermediate layer (2-3).

Preparation Example 3: A Composition for Forming an Adhesive Layer

(13) 72 g of 2-ethylhexyl acrylate (2-EHA), 13 g of 2-hydroxyethyl acrylate (2-HEA), 0.1 g of a polymerization initiator of benzoyl peroxide, and 100 g of methylethyl ketone (MEK) were used to prepare 185 g of an acryl-based polymer.

(14) 100 g of the above-prepared acryl-based polymer and 15 g of methacryloyloxy ethyl isocyanate (MOI) were reacted to prepare an acryl-based thermosetting resin.

(15) 30 g of the prepared thermosetting resin and 70 g of methylethyl ketone (MEK) were mixed to prepare a thermosetting composition for forming an adhesive layer.

Example 1

(16) On a releasable film (LO2, YoulChon Chemical), the composition for forming a hard coating layer according to Preparation Example 1-2 was applied, and heat cured at 110° C. for 2 minutes to form a hard coating layer with a thickness of 1.0 μm.

(17) Next, on the hard coating layer, the composition for forming a polyurethane film according to Preparation Example 2-2 was applied, and a transparent releasable base film was laminated on the coating layer so as to block oxygen, and cured using a UV lamp having a main wavelength of 365 nm to prepare a polyurethane-based intermediate layer having a thickness of 160 μm. Thereafter, the transparent releasable base film was removed.

(18) On a releasable film, the composition for forming an adhesive layer according to Preparation Example 3 was applied, and left in an oven at 110° C. for 3 minutes to form an adhesive layer having a thickness of 20 μm. Next, it was laminated with the polyurethane intermediate layer to finally prepare an adhesive film (a releasable film) for a semiconductor process including a hard coating layer, an intermediate layer including a polyurethane-based resin, and an adhesive layer (a releasable film) that were sequentially stacked. The releasable film formed on the adhesive layer can be removed immediately before a back grinding process.

Examples 2 to 4 and Comparative Examples 1 to 11

(19) A back grinding tape was prepared by the same method as Example 1, using the components in the following Table 1 in combination.

(20) However, in case a composition for forming a hard coating layer of Preparation Example 1-1 was used when forming a hard coating layer, after the composition was applied, it was heat dried at 70° C. for 1 minute, and irradiated by metal halide lamp UV at 800 mJ/cm.sup.2 UV-A to form a hard coating layer.

(21) TABLE-US-00001 TABLE 1 Polyurethane Hard coating layer intermediate layer Sum of polar Polar energy Polar energy energy Component ({circle around (1)}) Component ({circle around (2)}) ({circle around (1)} + {circle around (2)}) Example 1 Preparation 13.0 Preparation 2.2 15.2 Example 1-2 Example 2-2 Example 2 Preparation 12.3 Preparation 2.2 14.5 Example 1-3 Example 2-2 Example 3 Preparation 13.0 Preparation 1.1 14.1 Example 1-2 Example 2-3 Example 4 Preparation 12.3 Preparation 1.1 13.4 Example 1-3 Example 2-3 Comparative Preparation 10.3 Preparation 4.0 14.3 Example 1 Example 1-1 Example 2-1 Comparative Preparation 10.3 Preparation 2.2 12.5 Example 2 Example 1-1 Example 2-2 Comparative Preparation 10.3 Preparation 1.1 11.4 Example 3 Example 1-1 Example 2-3 Comparative Preparation 13.0 Preparation 4.0 17.0 Example 4 Example 1-2 Example 2-1 Comparative Preparation 12.3 Preparation 4.0 16.3 Example 5 Example 1-3 Example 2-1 Comparative Preparation 3.0 Preparation 4.0 7.0 Example 6 Example 1-4 Example 2-1 Comparative Preparation 3.0 Preparation 2.2 5.2 Example 7 Example 1-4 Example 2-2 Comparative Preparation 3.0 Preparation 1.1 4.1 Example 8 Example 1-4 Example 2-3

Experimental Example

(22) For the back grinding tapes prepared in the examples and comparative examples, the properties were evaluated as follows, and the results are shown in the following Table 2.

(23) 1) Polar Energy Parameters

(24) During the preparation processes of the examples and comparative examples, the composition for forming a hard coating layer was separately applied on a releasable base film, a hard coating layer was formed with a thickness of 1.0 μm by the same method as Example 1, and it was prepared into a sample of 20×50 mm.

(25) During the preparation processes of the examples and comparative examples, the composition for forming an intermediate layer including a polyurethane-based resin was separately applied on a base film, an intermediate layer including a polyurethane-based resin was formed with a thickness of 160 μm by the same method as Example 1, and it was prepared into a sample of 20×50 mm.

(26) For each sample prepared, a polar energy value was measured according to the following Mathematical Equation 1, and the results are shown in Table 1.
Polar Energy (dyne/cm)=Surface free energy (dyne/cm)−Dispersion (dyne/cm)  [Mathematical Equation 1]

(27) 2) Evaluation of Water Resistance

(28) During the preparation processes of the examples and comparative examples, the composition for forming an intermediate layer including a polyurethane-based resin was separated applied on a releasable base film, and an intermediate layer including a polyurethane-based resin was formed with a thickness of 160 μm ({circle around (1)}) by the same method, and it was prepared into a sample of 20×50 mm.

(29) The sample was immersed in distilled water of about 25° C. for 60 minutes, and then the thickness of the sample ({circle around (2)}) was measured, a thickness change rate before and after immersion ({circle around (2)}−{circle around (1)}/{circle around (1)})*100(%)) was measured, and water resistance was evaluated according to the following standard, and the results are shown in Table 2.

(30) <Water Resistance Evaluation Standard>

(31) ⊚: 0% to less than 1%

(32) ∘: 1% or more and less than 2%

(33) Δ: 2% or more and less than 4%

(34) X: 4% or more

(35) 3) Evaluation of Adhesive Property

(36) For the adhesive films for a semiconductor process prepared in the examples and comparative examples, a cross-cut test was conducted. Specifically, lines were drawn on the sample at an interval of 1 mm to make a checkerboard pattern, and then 3M Magic Tape was attached and pulled in a vertical direction to measure a degree of transcription of the hard coating film during the tape detachment process, and the adhesive property was evaluated according to the following standard, and the results are shown in Table 2.

(37) <Adhesive Property Evaluation Standard>

(38) ⊚: No transcription

(39) ∘: 5% or less transcribed

(40) Δ: greater than 5% and 25% or less transcribed

(41) X: 25% or more transcribed

(42) TABLE-US-00002 TABLE 2 Water resistance Adhesive property Example 1 ◯ ◯ Example 2 ◯ ◯ Example 3 ⊚ ◯ Example 4 ⊚ ◯ Comparative X ⊚ Example 1 Comparative ◯ X Example 2 Comparative ◯ X Example 3 Comparative X ⊚ Example 4 Comparative X ⊚ Example 5 Comparative X Δ Example 6 Comparative ◯ X Example 7 Comparative ◯ X Example 8

(43) As confirmed in Table 2,in the case of the comparative examples wherein polar energy parameters defined in the present invention were not fulfilled, water resistance and adhesive property of the films could not be simultaneously secured.

(44) It was confirmed that the examples of the present invention realized excellent water resistance and adhesive property, and thus, when used in a semiconductor process, particularly aback grinding process, they sufficiently protected a wafer pattern from moisture or external foreign substances, and after the process was completed, they could be easily removed without peel-off residue and layer separation of the film.

EXPLANATION OF SYMBOLS

(45) 10: back grinding tape 100: hard coating layer 200: intermediate layer including polyurethane-based resin 300: adhesive layer