Protective tape and method for manufacturing the same

Abstract

To provide a protective tape with high peel strength and / or low surface impedance. [Solution] The protective tape comprises a base film, an antistatic layer, and an adhesive layer. The antistatic layer is located on the surface of the base film and contains a first resin. The adhesive layer is located on the antistatic layer. Here, the adhesive layer contains a second resin, and the second resin is grafted with 6% to 12% by weight of glycidyl methacrylate and 3% to 5% by weight of vinyl acetate relative to the total weight of the second resin.

Description

Technical Field

[0006] , ,

[0007] , ,

[0001] The present invention relates to a tape and a method for manufacturing the same, and more particularly, to a protective tape and a method for manufacturing the same.

Background Art

[0002] With the progress of science and technology, the functions of electronic devices are becoming increasingly diversified. For example, current smartphones include functions such as making calls, accessing the Internet, taking photos and videos, and fingerprint authentication in addition to the call function. In order to cope with such development, it is necessary to improve the number and integration degree of chips in electronic devices. For the above reasons, how to reduce the thickness of chips and wafers has become an issue that many manufacturers are currently researching.

[0003] Currently, the back grinding process is a common process for reducing the thickness of wafers. Usually, before performing the back grinding process, a protective tape is attached to the surface of the wafer to prevent the elements on the wafer surface from being damaged during the back grinding process.

Summary of the Invention

Problems to be Solved by the Invention

[0004] Existing protective tapes have problems such as insufficient peel strength or antistatic effect.

Means for Solving the Problems

[0005] The present invention provides a protective tape having high peel strength and / or low surface impedance.

[0006] The present invention provides a method for manufacturing a protective tape capable of manufacturing a protective tape having high peel strength and / or low surface impedance.

[0007] At least one embodiment of the present invention provides a protective tape. The protective tape comprises a base film, a first antistatic layer, and an adhesive layer. The first antistatic layer is located on a first surface of the base film and comprises a first resin. The adhesive layer is located on the first antistatic layer, wherein the adhesive layer comprises a second resin, and the second resin is grafted with 6% to 12% by weight of glycidyl methacrylate and 3% to 5% by weight of vinyl acetate, relative to the total weight of the second resin.

[0008] At least one embodiment of the present invention provides a method for manufacturing a protective tape, comprising: providing a base film; providing a first mixture on the base film to form a first antistatic layer on the base film, wherein the first mixture comprises a first resin, an antistatic agent dispersed in the first resin, and an organic solvent, and the antistatic agent is composed of carbon nanotubes; and forming an adhesive layer on the surface of the first antistatic layer. [Effects of the Invention]

[0009] As described above, since the adhesive layer contains a resin with a relatively high graft ratio of polar functional groups, the protective tape can provide a peel strength greater than 30 N / 25 mm. Furthermore, since the first antistatic layer contains carbon nanotubes and organic solvents dispersed in the resin, the protective tape can provide a surface impedance less than 1 E+6 ohms. [Brief explanation of the drawing]

[0010] [Figure 1] This is a schematic cross-sectional view of a protective tape according to one embodiment of the present invention. [Figure 2] This is a flowchart of a method for manufacturing a protective tape according to one embodiment of the present invention. [Figure 3A] This is a schematic cross-sectional view of a method of using a protective tape according to one embodiment of the present invention. [Figure 3B] This is a schematic cross-sectional view of a method of using a protective tape according to one embodiment of the present invention. [Figure 3C]This is a schematic cross-sectional view of a method of using a protective tape according to one embodiment of the present invention. [Figure 3D] This is a schematic cross-sectional view of a method of using a protective tape according to one embodiment of the present invention. [Modes for carrying out the invention]

[0011] Figure 1 is a schematic cross-sectional view of a protective tape according to one embodiment of the present invention.

[0012] Referring to Figure 1, the protective tape 10 may include a base film 12, an antistatic layer 14, and an adhesive layer 18.

[0013] In some embodiments, the material of the base film 12 includes polyethylene terephthalate (PET), a copolymer of PET, or other suitable material. In some embodiments, the thickness T1 of the base film 12 is in the range of 25 μm to 150 μm, and more preferably in the range of 50 μm to 100 μm.

[0014] The antistatic layer 14 is located on the base film 12. For example, the antistatic layer 14 is formed on the corona-treated surface 12a of the base film 12. Corona treatment breaks and decomposes the chemical bonds on the surface 12a of the base film 12, increasing the roughness and surface area of ​​the surface 12a, thus allowing the antistatic layer 14, which is later formed on the surface 12a, to adhere well to the base film 12. In some embodiments, corona treatment changes the surface 12a of the base film 12 into a polar surface.

[0015] In some embodiments, the thickness T2 of the antistatic layer 14 (thickness of the dry film) is in the range of 80 nanometers (nm) to 1000 nm. In some embodiments, the thickness T2 of the antistatic layer 14 is in the range of 100 nm to 500 nm, for example, 200 nm or 300 nm.

[0016] The antistatic layer 14 may include a first resin and an antistatic agent dispersed in the first resin. The first resin has good adhesion to the base film 12 and good compatibility with the antistatic agent, thus assisting in the dispersion of the antistatic agent and thereby improving the antistatic effect. In some embodiments, the material of the first resin includes at least one of polyurethane (PU), acrylic, polyester resin, epoxy resin, and alkyd resin.

[0017] The antistatic agent of the antistatic layer 14 may include carbon nanotubes. In some embodiments, the antistatic agent of the antistatic layer 14 is composed of carbon nanotubes. Carbon nanotubes are relatively long; for example, the length of the carbon nanotubes is greater than 12 micrometers (μm). In some embodiments, the length of the carbon nanotubes is greater than 12 μm and 30 μm or less. In some embodiments, the length of the carbon nanotubes is greater than 12 μm and 20 μm or less. In some embodiments, the antistatic agent contains only carbon nanotubes with a length greater than 12 μm and 20 μm or less. Carbon nanotubes are conductive in themselves, their component is carbon (sulfur-free), they have a low surface impedance, and because the length of the carbon nanotubes is sufficiently long, they can form contact points, thereby further lowering the surface impedance and maintaining the surface impedance even after corona treatment. In some embodiments, the antistatic agent does not contain metal oxides, which have relatively high surface impedance themselves. In some embodiments, the antistatic agent does not contain a conductive polymer, and the structure of the conductive polymer itself does not contain sulfur (making it unsuitable for wafers and semiconductor factories). Therefore, it mainly forms an antistatic effect through the movement of π electrons, but corona treatment disrupts the movement of π electrons, reducing impedance. Accordingly, the present invention can improve the corona resistance of the antistatic layer 14 by making the antistatic agent sulfur-free. In this way, even when the protective tape 10 product needs to be subjected to further corona treatment before subsequent processing, the impedance of the protective tape 10 can be maintained without a decrease.

[0018] The antistatic layer 14 can further contain additives, such as a leveling agent or a wetting agent. In some embodiments, the antistatic layer 14 further contains surface-modified filler particles dispersed in the first resin, and the surface-modified filler particles are, for example, surface-modified silica. In some embodiments, the surface-modified filler particles help prevent the antistatic layer 14 from being damaged by a roller or other object during manufacturing or use.

[0019] The adhesive layer 18 can be located on the surface 14a of the antistatic layer 14. That is, the antistatic layer 14 and the adhesive layer 18 are located on the same side of the base film 12, and the antistatic layer 14 is located between the adhesive layer 18 and the base film 12. The thickness T3 of the adhesive layer 18 may be in the range of 0.5 μm to 3.0 μm. In some embodiments, the thickness T3 of the adhesive layer 18 is in the range of 1.0 μm to 2.0 μm, for example, 1.2 μm or 1.6 μm.

[0020] The adhesive layer 18 can contain a second resin grafted with a monomer having a polar functional group. For example, the second resin of the adhesive layer 18 can contain a polyolefin resin. In some embodiments, the polyolefin resin in the second resin of the adhesive layer 18 can contain at least one of polyolefins, such as polyethylene, polypropylene, and / or other suitable polymer materials. In some embodiments, the polyolefin resin in the second resin of the adhesive layer 18 can contain a hot melt resin, thereby improving the adhesive strength.

[0021] The monomer having a polar functional group in the second resin of the adhesive layer 18 may include at least one of glycidyl methacrylate (GMA), vinyl acetate (VA), maleic anhydride (MA), and other suitable monomers. In some embodiments, the monomer having a polar functional group contains at least 6% to 12% by weight of GMA relative to the total weight of the second resin. In some embodiments, the monomer having a polar functional group contains at least 6% to 12% by weight of GMA and 3% to 5% by weight of VA relative to the total weight of the second resin. In some embodiments, the monomer having a polar functional group contains at least 6% to 12% by weight of GMA and 20% to 30% by weight of maleic anhydride relative to the total weight of the second resin. In some embodiments, the monomer having polar functional groups, relative to the total weight of the second resin, includes at least 6% to 12% by weight of GMA, 3% to 5% by weight of VA, and 20% to 30% by weight of maleic anhydride. By increasing the graft ratio of polar functional groups, the softening point of the adhesive layer 18 can be lowered, thereby improving the peel strength of the adhesive layer 18. In some embodiments, the softening point of the adhesive layer 18 is about -35°C to -25°C. In some embodiments, the peel strength of the adhesive layer 18 can reach 30 N / 25 mm or more, so that the problem of delamination can be prevented when the protective tape 10 is peeled off for subsequent use.

[0022] The protective tape 10 can further include an antistatic layer 16, and the antistatic layer 16 can be located on the base film 12. In some embodiments, the antistatic layer 14 and the antistatic layer 16 are located on opposite surfaces of the base film 12, providing antistatic performance on both surfaces. For example, the antistatic layer 16 is formed on the corona-treated surface 12b of the base film 12, and the surface 12b faces the surface 12a. The material composition of the antistatic layer 16 may be the same as or different from that of the antistatic layer 14. Also, the thickness of the antistatic layer 16 may be the same as or different from that of the antistatic layer 14. Since the surface impedances of both surfaces of the protective tape 10 are made smaller than 1E+6 ohms by the antistatic layer 14 and the antistatic layer 16, the antistatic layer 14 and the antistatic layer 16 can reduce or prevent damage to the wafer caused by static electricity during the wafer backgrinding process.

[0023] FIG. 2 is a flowchart of a method for manufacturing a protective tape according to one embodiment of the present invention. It should be noted here that since the embodiment of FIG. 2 incorporates the content of the embodiment of FIG. 1, the description of the same technical content will be omitted. For the description of the omitted part, reference can be made to the above-described embodiment, and thus it will not be repeatedly described here.

[0024] Referring to FIGS. 1 and 2 simultaneously, in step S1, a base film is provided. For example, a PET base film 12 is provided. In some embodiments, further, corona treatment is performed on the base film 12 to form a corona-treated surface of the base film 12. For example, corona treatment is performed on the surfaces 12a and 12b of the base film 12 to form the corona-treated surfaces 12a and 12b of the base film 12.

[0025] In step S2, an antistatic layer is formed on the base film. For example, antistatic layers 14 and 16 are formed on corona-treated surfaces 12a and 12b of the base film 12, respectively. The antistatic layers 14 and 16 may include a first resin and an antistatic agent dispersed in the first resin. The material of the first resin may include at least one of polyurethane (PU), acrylic, polyester resin, epoxy resin, and alkyd resin. The antistatic agent is composed of carbon nanotubes.

[0026] In some embodiments, a method for forming antistatic layers 14, 16 includes providing a first mixture on a substrate film. For example, a film layer of the first mixture is formed on the substrate film by printing, coating, or other suitable manufacturing process, and then the film layer of the first mixture is solidified to form the antistatic layer 14 or antistatic layer 16.

[0027] The first mixture may include 2 wt% to 20 wt% of a first resin, 1 wt% to 10 wt% of an antistatic agent, 0.05 wt% to 10 wt% of surface-modified filler particles, 0.05 wt% to 10 wt% of additives, 25 wt% to 85 wt% of a first solvent, and 1 wt% to 10 wt% of a second solvent. In some embodiments, the material of the first resin includes at least one of polyurethane, acrylic, polyester resin, epoxy resin, and alkyd resin. In some embodiments, the antistatic agent is composed of carbon nanotubes. In some embodiments, the additive includes a wetting agent, a leveling agent, or other suitable additives. In some embodiments, the additive includes a leveling agent of type BYK-381 provided by BYK. In some embodiments, the first solvent includes water. In some embodiments, the second solvent includes an organic solvent, such as alcohols, which reduces the surface impedance value and improves the antistatic effect. In some embodiments, the second solvent comprises ethanol or propanol. Since the first mixture contains carbon nanotubes and alcohols with a length greater than 12 μm, the antistatic layers 14, 16 can have a surface impedance less than 1E+6 ohms.

[0028] In step S3, an adhesive layer is formed on the surface of the antistatic layer. For example, an adhesive layer 18 is formed on the surface 14a of the antistatic layer 14. In some embodiments, the method for forming the adhesive layer 18 includes providing a second mixture to the surface 14a. For example, a film layer of the second mixture is formed on the surface 14a of the antistatic layer 14 by printing, coating, or other suitable process, and then the film layer of the second mixture is solidified to form the adhesive layer 18. The second mixture may contain 5 wt% to 20 wt% of a second resin, 0.05 wt% to 10 wt% of additives, and 50 wt% to 90 wt% of a third solvent, wherein the second resin has a high graft ratio of polar functional groups. In some embodiments, the second resin includes a hot-melt adhesive resin or polyolefin resin grafted with GMA, VA, and MA. In some embodiments, the additive includes an antifoaming agent of type BYK-8800 provided by BYK. In some embodiments, the third solvent includes toluene. The second mixture contains 5 wt% to 20 wt% of the second resin, and since the second resin has a high polar functional group graft ratio, the peel strength of the adhesive layer 18 can reach 30 N / 25 mm or more.

[0029] Figures 3A to 3D are cross-sectional views of a method of using protective tape according to one embodiment of the present invention. It should be noted that the embodiments in Figures 3A to 3D utilize the same technical content as the embodiment in Figure 1; therefore, the same technical content will not be explained again. The omitted parts can be explained by referring to the embodiments described above, and will not be repeated here.

[0030] Referring to Figure 3A, after forming the adhesive layer 18, a surface absorbing layer 30 can be formed on the adhesive layer 18 to form a protective tape 10'. In some embodiments, the protective tape 10' includes a base film 12, an antistatic layer 14, an antistatic layer 16, the adhesive layer 18, and the surface absorbing layer 30. In some embodiments, the material of the surface absorbing layer 30 includes a polyolefin. For example, the surface absorbing layer 30 includes a hot-melt polyolefin, such as polyethylene, polypropylene, or other suitable polymer material. In this way, the adhesive layer 18 containing a hot-melt adhesive resin can produce high adhesive strength with the hot-melt polyolefin of the surface absorbing layer 30. In some embodiments, the surface absorbing layer 30 and the adhesive layer 18 are formed using different manufacturing parameters, so the surface absorbing layer 30 and the adhesive layer 18 have different properties, but the present invention is not limited thereto. In other embodiments, the surface absorbing layer 30 and the adhesive layer 18 have similar properties. In some embodiments, the surface absorbing layer 30 is formed on the adhesive layer 18 by a lamination method. In some embodiments, the protective tape 10' further includes a photosensitive adhesive 32 located on the unevenness-absorbing layer 30.

[0031] Referring to Figure 3B, the protective tape 10' is attached to the surface of the wafer 34. In some embodiments, the surface of the wafer 34 has a plurality of conductive structures 36. The conductive structures 36 are, for example, solder balls, passive components, or other components. In some embodiments, the unevenness-absorbing layer 30 is bonded to the adhesive layer 18 to form a photosensitive adhesive 32 on the unevenness-absorbing layer 30, and then the photosensitive adhesive 32 of the protective tape 10' is attached to the surface of the wafer 34, thereby placing the photosensitive adhesive 32 between the unevenness-absorbing layer 30 and the wafer 34. In some embodiments, the photosensitive adhesive 32 and the unevenness-absorbing layer 30 are attached to the surface of the wafer 34, and then the adhesive layer 18 of the protective tape 10' is attached to the unevenness-absorbing layer 30.

[0032] Referring to Figure 3C, a backgrinding process is performed on wafer 34 to form a thinned wafer 34'. In some embodiments, the backgrinding process is chemical mechanical polishing (CMP).

[0033] Finally, referring to Figure 3D, the photosensitive adhesive 32 is irradiated with light to reduce its tackiness, and then the protective tape 10' is removed from the surface of the wafer 34'. Because the peel strength between the adhesive layer 18 and the unevenness absorption layer 30 is greater than 30 N / 25 mm, delamination within the protective tape 10' can be prevented when the protective tape 10' is peeled off, thus reducing the likelihood of delamination problems between the unevenness absorption layer 30 and the substrate film 12. In addition, because the surface impedance of the antistatic layers 14 and 16 is less than 1 E + 6 ohms, the protective tape 10' has an antistatic effect, preventing static electricity generated when the protective tape 10' is peeled off from damaging the conductive structure 36 on the surface of the wafer 34'.

[0034] The following provides some examples of the antistatic layer and adhesive layer of the present invention. However, these examples are illustrative, and the present invention is not limited to these examples.

[0035] <Antistatic layer>

[0036] Example 1

[0037] A first mixture was provided on a substrate film to form an antistatic layer. The first mixture in Example 1 contained 20 wt% PU, 2 wt% carbon nanotubes with a length of 12 μm to 20 μm, 2.4 wt% packing particles, 0.24 wt% packing particle surface modifier, 1 wt% additive BYK-381, 72 wt% water, and 5 wt% alcohols.

[0038] After the first mixture was solidified, an antistatic layer with a thickness of 0.2 μm was formed.

[0039] Example 2

[0040] A first mixture was provided on a substrate film to form an antistatic layer. The first mixture in Example 2 contains 20 wt% PU, 2 wt% carbon nanotubes with a length of 12 μm to 20 μm, 2.4 wt% packing particles, 0.24 wt% packing particle surface modifier, 1 wt% additive BYK-381, 69 wt% water, and 8 wt% alcohols.

[0041] After the first mixture was solidified, an antistatic layer with a thickness of 0.2 μm was formed.

[0042] Example 3

[0043] A first mixture was provided on a substrate film to form an antistatic layer. The first mixture in Example 3 contained 20 wt% PU, 5 wt% carbon nanotubes with a length of 12 μm to 20 μm, 2.4 wt% packing particles, 0.24 wt% packing particle surface modifier, 1 wt% additive BYK-381, 69 wt% water, and 5 wt% alcohols.

[0044] After the first mixture was solidified, an antistatic layer with a thickness of 0.25 μm was formed.

[0045] Example 4

[0046] A first mixture was provided on a substrate film to form an antistatic layer. The first mixture in Example 4 contains 20 wt% PU, 5 wt% carbon nanotubes with a length of 12 μm to 20 μm, 2.4 wt% packing particles, 0.24 wt% packing particle surface modifier, 1 wt% additive BYK-381, 66 wt% water, and 8 wt% alcohols.

[0047] After the first mixture was solidified, an antistatic layer with a thickness of 0.25 μm was formed.

[0048] Example 5

[0049] A first mixture was provided on a substrate film to form an antistatic layer. The first mixture in Example 5 contains 20 wt% PU, 8 wt% carbon nanotubes with a length of 12 μm to 20 μm, 2.4 wt% packing particles, 0.24 wt% packing particle surface modifier, 1 wt% additive BYK-381, 66 wt% water, and 5 wt% alcohols.

[0050] After the first mixture was solidified, an antistatic layer with a thickness of 0.28 μm was formed.

[0051] Comparative Example 1

[0052] The first mixture was provided on a substrate film to form an antistatic layer. The first mixture of Comparative Example 1 contained 20 wt% polyester, 5 wt% metal oxide, 2.4 wt% filler particles, 0.24 wt% filler particle surface modifier, 1 wt% additive BYK-381, 69 wt% water, and 5 wt% alcohols.

[0053] After the first mixture was solidified, an antistatic layer with a thickness of 0.25 μm was formed.

[0054] Comparative Example 2

[0055] The first mixture was provided on a substrate film to form an antistatic layer. The first mixture of Comparative Example 2 contained 20 wt% PU, 5 wt% carbon nanotubes with a length of 8 μm to 12 μm, 2.4 wt% packing particles, 0.24 wt% packing particle surface modifier, 1 wt% additive BYK-381, 69 wt% water, and 5 wt% alcohols.

[0056] After the first mixture was solidified, an antistatic layer with a thickness of 0.25 μm was formed.

[0057] Comparative Example 3

[0058] The first mixture was provided on a substrate film to form an antistatic layer. The first mixture of Comparative Example 3 contained 20 wt% PU, 5 wt% carbon nanotubes with a length of 12 μm to 20 μm, 2.4 wt% packing particles, 0.24 wt% packing particle surface modifier, 1 wt% additive BYK-381, and 74 wt% water, with no alcohols added.

[0059] After the first mixture was solidified, an antistatic layer with a thickness of 0.25 μm was formed.

[0060] Table 1 shows some of the characteristics of the antistatic layers in Examples 1 to 5 and Comparative Examples 1 to 3.

[0061] [Table 1]

[0062] In Table 1, surface impedance and surface impedance after corona treatment refer to the surface impedance of the antistatic layer before and after corona treatment, respectively. Light transmittance and haze refer to the light transmittance and haze of the antistatic layer and the entire substrate film. Adhesion refers to the adhesion between the antistatic layer and the substrate film obtained by a cross-cut test.

[0063] As can be seen from Table 1, in Examples 1 to 5, the surface impedance of the antistatic layer after corona treatment is still less than 1E+6 ohms. Therefore, even if further corona treatment is required in subsequent processing steps, the surface impedance of the antistatic layer will not increase or lose its antistatic capability. Furthermore, in Comparative Example 1, a metal oxide was used, so its surface impedance did not reach <1.0E+06Ω. In Comparative Example 2, carbon nanotubes with a length of 8-12um were used, so its surface impedance did not reach <1.0E+06Ω. In Comparative Example 3, no alcohols were added, so its surface impedance did not reach <1.0E+06Ω.

[0064] <Adhesive layer>

[0065] Example 6

[0066] A second mixture was applied to the surface of the antistatic layer to form an adhesive layer. The second mixture in Example 6 contained 10 wt% resin, 1 wt% additive BYK-8800, and 89 wt% toluene, and the resin was grafted with 10 wt% GMA, 3 wt% VA, and 25 wt% MA.

[0067] After the second mixture solidified, an adhesive layer with a thickness of 0.8 μm was formed.

[0068] Example 7

[0069] A second mixture was applied to the surface of the antistatic layer to form an adhesive layer. The second mixture in Example 7 contained 15 wt% resin, 1 wt% additive BYK-8800, and 84 wt% toluene, and the resin was grafted with 10 wt% GMA, 3 wt% VA, and 25 wt% MA.

[0070] After the second mixture solidified, an adhesive layer with a thickness of 1.2 μm was formed.

[0071] Example 8

[0072] A second mixture was applied to the surface of the antistatic layer to form an adhesive layer. The second mixture in Example 8 contained 20 wt% resin, 1 wt% additive BYK-8800, and 79 wt% toluene, and the resin was grafted with 10 wt% GMA, 3 wt% VA, and 25 wt% MA.

[0073] After the second mixture was solidified, an adhesive layer with a thickness of 1.6 μm was formed.

[0074] Example 9

[0075] A second mixture was applied to the surface of the antistatic layer to form an adhesive layer. The second mixture in Example 9 contained 15 wt% resin, 1 wt% additive BYK-8800, and 84 wt% toluene, and the resin was grafted with 10 wt% GMA, 5 wt% VA, and 27 wt% MA.

[0076] After the second mixture solidified, an adhesive layer with a thickness of 1.2 μm was formed.

[0077] Example 10

[0078] A second mixture was applied to the surface of the antistatic layer to form an adhesive layer. The second mixture in Example 10 contained 20 wt% resin, 1 wt% additive BYK-8800, and 84 wt% toluene, and the resin was grafted with 10 wt% GMA, 5 wt% VA, and 27 wt% MA.

[0079] After the second mixture was solidified, an adhesive layer with a thickness of 1.6 μm was formed.

[0080] Comparative Example 4

[0081] A second mixture was applied to the surface of the antistatic layer to form an adhesive layer. The second mixture in Comparative Example 4 contained 20 wt% resin, 1 wt% additive BYK-8800, and 84 wt% toluene, and the resin was grafted with only 3 wt% VA.

[0082] After the second mixture was solidified, an adhesive layer with a thickness of 1.6 μm was formed.

[0083] Comparative Example 5

[0084] A second mixture was applied to the surface of the antistatic layer to form an adhesive layer. The second mixture in Comparative Example 5 contained 20 wt% resin, 1 wt% additive BYK-8800, and 84 wt% toluene, and the resin was grafted with only 6 wt% GMA.

[0085] After the second mixture was solidified, an adhesive layer with a thickness of 1.6 μm was formed.

[0086] Comparative Example 6

[0087] A second mixture was applied to the surface of the antistatic layer to form an adhesive layer. The second mixture in Comparative Example 6 contained 3 wt% resin, 1 wt% additive BYK-8800, and 96 wt% toluene, and the resin was grafted with 10 wt% GMA, 3 wt% VA, and 25 wt% MA.

[0088] After the second mixture solidified, an adhesive layer with a thickness of 0.3 μm was formed.

[0089] [Table 2]

[0090] In Table 2, the softening point refers to the softening point of the adhesive layer. The peel strength refers to the peel strength between the adhesive layer and the antistatic layer. The adhesion refers to the adhesion between the adhesive layer and the antistatic layer obtained by the cross-cut test.

[0091] As can be seen from Table 2, in Examples 6 to 10, the softening point of the adhesive layer reached -28 to -33°C, and the peel strength between the adhesive layer and the antistatic layer reached 30 N / 25 mm or higher in all cases, and the adhesion of both the adhesive layer and the antistatic layer met the criteria for cross-cut test 5B. In Comparative Example 4, the softening point was higher due to the low amount of GMA and MA grafts, and the peel strength did not reach 30 N / 25 mm. In Comparative Example 5, the softening point was higher due to the low amount of VA and MA grafts, and the peel strength did not reach 30 N / 25 mm. In Comparative Example 6, the thickness was thinner due to the low resin content, and the peel strength did not reach 30 N / 25 mm.

[0092] As described above, the adhesive layer of the protective tape of the present invention can have its softening point lowered by increasing the resin graft ratio, thereby improving the peel strength of the protective tape. Furthermore, by using a hot-melt adhesive resin in the adhesive layer, high adhesive strength can be achieved with the heat-melt type polyolefin of the unevenness absorption layer. In addition, the protective tape of the present invention can further reduce the surface impedance of the antistatic layer to less than 1.0E+06Ω by including relatively long carbon nanotubes in the antistatic layer, and can improve its corona resistance by not including sulfur in the antistatic agent.

[0093] Although the present invention has been disclosed by the embodiments described above, these do not limit the invention, and any person with ordinary skill in the art may make some changes or modifications without departing from the spirit and scope of the invention. Therefore, the scope of protection of the present invention shall be determined by the claims described below. [Industrial applicability]

[0094] The protective tape of the present invention can be used in semiconductor device manufacturing processes and can also be used in the manufacture of various electronic devices (e.g., smartphones), thus possessing industrial value. [Explanation of symbols]

[0095] 10, 10' protective tape 12. Base film 12a, 12b, 14a surface 14, 16 Antistatic layer 18 Adhesive layer 30 Unevenness absorption layer 32 Photosensitive adhesive 34, 34' wafer 36 Conductive structure S1, S2, S3, S4 Steps T1, T2, T3 thickness

Claims

1. A base film and A first antistatic layer located on the first surface of the base film and containing a first resin, An adhesive layer located on the first antistatic layer, Includes, A protective tape wherein the adhesive layer contains a second resin, and the second resin is grafted with 6% to 12% by weight of glycidyl methacrylate and 3% to 5% by weight of vinyl acetate relative to the total weight of the second resin.

2. The protective tape according to claim 1, wherein the second resin comprises a polyolefin resin.

3. The protective tape according to claim 1, wherein the second resin is further grafted with 20% to 30% by weight of maleic anhydride.

4. The first antistatic layer further comprises an antistatic agent dispersed in the first resin, The protective tape according to claim 1, wherein the antistatic agent comprises carbon nanotubes that are larger than 12 μm and have a length of 30 μm or less.

5. The protective tape according to claim 4, wherein the antistatic agent is composed of carbon nanotubes.

6. The protective tape according to claim 4, wherein the first antistatic layer does not contain metal oxides and does not contain sulfur.

7. The protective tape according to claim 1, further comprising a second antistatic layer located on the second surface of the base film, wherein the second surface faces the first surface.

8. The protective tape according to claim 1, wherein the material of the base film comprises polyethylene terephthalate or a copolymer of polyethylene terephthalate.

9. The protective tape according to claim 1, wherein the surface impedance of the protective tape is less than 1E+6 ohms.

10. The material further includes an unevenness-absorbing layer that adheres to the aforementioned adhesive layer, The protective tape according to claim 1, wherein the peel strength between the unevenness-absorbing layer and the base film is greater than 30 N / 25 mm.

11. To provide a base film, The first mixture is provided on the base film to form a first antistatic layer on the base film, This includes forming an adhesive layer on the surface of the first antistatic layer, The first mixture is The first resin and Dispersed in the first resin, an antistatic agent composed of carbon nanotubes, The organic solvent dispersed in the first resin, A method for manufacturing protective tape, including the tape itself.

12. A method for producing a protective tape according to claim 11, wherein the first mixture comprises 2 wt% to 20 wt% polyurethane, 1 wt% to 10 wt% carbon nanotubes, 1 wt% to 10 wt% alcohols, and 25 wt% to 85 wt% water.

13. Forming the adhesive layer on the surface of the first antistatic layer includes providing the second mixture to the surface. The second mixture comprises 5 wt% to 20 wt% of a second resin and 50 wt% to 90 wt% of toluene. The method for manufacturing a protective tape according to claim 11, wherein the second resin is grafted with a monomer having a polar functional group.

14. A method for producing a protective tape according to claim 13, wherein, with respect to the total weight of the second resin, the monomer having a polar functional group comprises 6% to 12% by weight of glycidyl methacrylate, 3% to 5% by weight of vinyl acetate, and 20% to 30% by weight of maleic anhydride.

15. The method for manufacturing a protective tape according to claim 11, further comprising forming a second antistatic layer on the surface of the base film opposite to the first antistatic layer.

16. The method further includes adhering the adhesive layer to the unevenness-absorbing layer, The method for manufacturing a protective tape according to claim 11, wherein the peel strength between the unevenness absorption layer and the base film is greater than 30 N / 25 mm.

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