TW201343850A - Adhesive tape - Google Patents

Abstract

This invention provides an adhesive tape which has anexcellent balanced adhesion force and the peeling property and the step difference followability, and allows fabrication through the co-extrusion molding. The adhesive tape of this invention is provided with an adhesive layer formed by a resin composition comprising an amorphous propylene-(1-butylene) copolymer. The adhesive tape, when being adhered to an adhered body with a step difference of 30 micron, floats adjacent to the lower portion of the step difference. The width of the non-connection portion of the adhesive tape and the adhered body is less than 650 micron. The adhesion force of the adhesive tape to a silicon semiconductor mirror wafer is less than 2.0N/20mm, as measured according to the JIS Z 0237(2000) method (bonding conditions: 2kg roller 1 pass back; peeling speed: 300 mm/min; peeling angle: 180 DEG).

Description

Adhesive tape

The present invention relates to an adhesive tape.

A semiconductor wafer including germanium, gallium, arsenic or the like is manufactured in a large diameter state, and the back surface is polished after patterning on the surface, and the thickness of the wafer is usually as thin as about 100 to 600 μm, and then dicing is performed. The component is then transferred to the installation step.

In the step of polishing the back surface of the semiconductor wafer (back grinding step), an adhesive tape is used to protect the pattern surface of the semiconductor wafer. The adhesive tape is usually peeled off after the back grinding step. The adhesive tape used for this purpose must have an adhesive force that does not peel off during the back grinding step, and on the other hand, it is required to be easily peeled off after the back grinding step, and to the extent that the semiconductor wafer is not damaged. Low adhesion.

Conventionally, as such an adhesive tape, an adhesive tape to which an adhesive is applied to a substrate is used. For example, an adhesive layer coated with an acrylic adhesive on a substrate containing a polyethylene resin is proposed. Adhesive tape (Patent Document 1). However, in the manufacture of such an adhesive tape, a large number of steps such as a step of forming a substrate and a step of applying an adhesive solution are required, and the manufacturing cost is high. Moreover, there is a problem of discharging a large amount of CO ₂ . Further, in the above production method, since the organic solvent is removed by drying after the application of the pressure-sensitive adhesive solution, there is a problem in that environmental load is caused by volatilization of the organic solvent.

As a method for solving such a problem, a method of coextruding a substrate forming material and an adhesive forming material can be mentioned. However, the material available for co-extrusion is a thermoplastic resin, and in the case of using a thermoplastic resin, it is difficult to achieve both a proper adhesion and a pattern for a semiconductor wafer. Follow-up of bumps (step follower). That is, the adhesive tape-adhering agent adjusted to such an extent that the adhesive force can be easily peeled off is too hard, and the step followability is insufficient, and the purpose of protecting the semiconductor wafer cannot be sufficiently achieved. On the other hand, the adhesive tape which is adjusted to exhibit good step followability is too strong, and there is a problem that the semiconductor wafer is damaged or the adhesive remains on the semiconductor wafer during peeling.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] International Publication WO2007/116856

The present invention has been made to solve the above-mentioned problems, and an object thereof is to provide an adhesive tape which is excellent in balance between adhesion and peelability and step followability and which can be produced by co-extrusion molding.

The adhesive tape of the present invention comprises an adhesive layer composed of a resin composition containing an amorphous propylene-(1-butene) copolymer, which is attached to an adherend having a step of 30 μm. The width of the portion where the adhesive tape does not contact the adherend is 650 μm or less, and the method according to JIS Z 0237 (2000) is used. (Adhesion conditions: 1 kg roller reciprocating once, peeling speed: 300 mm/ Minute, peeling angle: 180°) The adhesion of the adhesive tape to the tantalum semiconductor mirror wafer was 2.0 N/20 mm or less.

In a preferred embodiment, the storage modulus (G') of the adhesive layer at 20 ° C is 2.0 MPa or less.

In a preferred embodiment, the adhesive layer has an indentation hardness of 0.8 MPa or more when pressed into a 1000 nm by a nanoindenter.

In a preferred embodiment, the resin composition of the adhesive tape of the present invention comprises an amorphous propylene-(1-butene) copolymer and a crystalline resin, and the crystalline resin is crystalline C. An ene-(1-butene) copolymer and/or a crystalline ethylene-(1-butene) copolymer.

In a preferred embodiment, the total content of the constituent units derived from 1-butene in the resin composition is 5% by weight or more based on the total weight of the resin in the resin composition.

In a preferred embodiment, in the adhesive tape of the present invention, the adhesive tape has a thickness of 5 μm to 1000 μm.

In a preferred embodiment, the adhesive tape of the present invention further comprises a base material layer, and the adhesive layer forming material and the base material layer forming material are obtained by co-extrusion molding.

In a preferred embodiment, the adhesive tape of the present invention is used for semiconductor wafer processing.

According to the present invention, by providing an adhesive layer containing a specific copolymer, it is possible to provide an adhesive tape having excellent balance of adhesion and peelability and excellent step followability. Such an adhesive tape is particularly suitable for use as an adhesive tape for semiconductor wafer processing. Further, according to the present invention, it is produced by co-extrusion molding, and it is possible to provide an adhesive tape which can be produced in a small number of steps without using an organic solvent.

10‧‧‧Adhesive layer

20‧‧‧Substrate layer

100‧‧‧Adhesive tape

200‧‧‧Adhesive body

A‧‧‧ width of the step

X‧‧‧ step

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic cross-sectional view showing an adhesive tape according to a preferred embodiment of the present invention.

Fig. 2 is a view for explaining the "floating width" which is an index of the step followability of the adhesive tape of the present invention.

A. The overall composition of the adhesive tape

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic cross-sectional view showing an adhesive tape according to a preferred embodiment of the present invention. The adhesive tape 100 is provided with an adhesive layer 10 formed of a resin composition containing an amorphous propylene-(1-butene) copolymer. The adhesive tape 100 preferably further includes a base material layer 20 .

The thickness of the adhesive tape 100 is preferably from 5 μm to 1000 μm, more preferably from 100 μm to 300 μm, still more preferably from 130 μm to 250 μm.

The thickness of the adhesive layer 10 is preferably from 2 μm to 100 μm, more preferably from 20 μm to 80 μm, still more preferably from 30 μm to 60 μm.

The thickness of the base material layer 20 is preferably from 3 μm to 900 μm, more preferably from 20 μm to 220 μm, still more preferably from 70 μm to 190 μm.

The adhesive tape of the present invention may further comprise any other suitable layer. The other layer may, for example, be a surface layer provided on the opposite side of the base layer from the adhesive layer to impart heat resistance to the adhesive tape.

In this specification, "floating width" is used as an indicator of the step followability of the adhesive tape. The "floating width" as shown in FIG. 2 means that when the adhesive tape 100 is attached to the adherend 200 having the step difference x, the adhesive tape floats near the step and adheres to the adherend. The width a of the 200 non-contact parts. This small floating width means that the adhesive tape has excellent step followability and can well fill the unevenness of the adherend.

When the adhesive tape of the present invention is attached to a tantalum semiconductor mirror wafer, the floating width of the adhesive tape of the present invention after the attachment is preferably 650 μm or less, and more preferably 500 μm, with respect to the adhesive body having a step of 30 μm. Hereinafter, it is particularly preferably 450 μm or less. The lower limit of the floating width of the adhesive tape of the present invention with respect to the adherend having a step of 30 μm is preferably as small as possible, as long as the effect of the present invention is obtained, and is preferably 1 μm or more, and more preferably 5 μm or more. . The adhesive tape of the present invention has a small floating width, that is, it has a good followability to the unevenness of the adherend (for example, a pattern of a semiconductor wafer), and the unevenness can be satisfactorily filled. When such an adhesive tape is used for pattern surface protection in semiconductor wafer processing, pressure can be uniformly applied to the semiconductor wafer during the back grinding step, and the back surface of the semiconductor wafer is free from the unevenness of the pattern surface. Grinding can be performed smoothly. Also, cracking of the semiconductor wafer can be prevented. Further, it is possible to prevent the polishing water from infiltrating between the semiconductor wafer and the adhesive tape.

When the adhesive tape of the present invention is attached to a tantalum semiconductor mirror wafer, the amount of increase in the floating width with respect to a step of 30 μm after one hour of attachment is preferably within 10%, and more preferably within 5%. . If this range is used, after attaching the adhesive tape to the semiconductor wafer, When the semiconductor wafer is supplied to the back surface polishing step after a certain period of time, the state in which the unevenness of the pattern surface of the semiconductor wafer is well filled can be maintained, and the back surface can be smoothly polished as described above, and the semiconductor can be prevented. The wafer is broken. More preferably, the width of the above-mentioned adhesive tape does not increase after one hour after the attachment.

When the adhesive tape of the present invention is attached to a tantalum semiconductor mirror wafer, the floating width of the adhesive tape of the present invention with respect to a step of 30 μm after attaching and passing for one hour is preferably over time. The floating width does not change.

The adhesive tape of the present invention uses a semiconductor mirror wafer (manufactured by a tantalum) as a test plate, and uses a method according to JIS Z 0237 (2000) (adhesion conditions: 1 kg roller reciprocating once, peeling speed: 300 mm/min, peeling angle: 180 °) The measured adhesive force is 2.0 N/20 mm or less, preferably 0.1 N/20 mm to 2.0 N/20 mm, further preferably 0.15 N/20 mm to 1.5 N/20 mm, more preferably 0.15 N/20 mm to 1.0 N. /20mm, especially preferably 0.25N/20mm~1.0N/20mm. In this range, it is possible to obtain an adhesive tape which can achieve both adhesion and peeling properties, for example, does not peel off during polishing in the back surface polishing step of the semiconductor wafer, and can be easily peeled off after the polishing process. In the present invention, for example, an amorphous propylene-(1-butene) copolymer is contained in the adhesive layer as a main component to exhibit an adhesive force, and the adhesive force is adjusted by adding a crystalline resin. The details of the constituent components of the adhesive layer will be described later.

The adhesive tape of the present invention uses a polyimide-coated wafer as a test plate and uses a method according to JIS Z 0237 (2000) (adhesion conditions: 1 kg roller reciprocating once, peeling speed: 300 mm/min, peeling angle: 180 °) The adhesion to the polyimide coating surface is preferably 0.1 N/20 mm to 3.5 N/20 mm, more preferably 0.3 N/20 mm to 2.0 N/20 mm, and more preferably 0.3 N/20 mm. 1.5N/20mm, especially 0.5N/20mm~1.2N/20mm.

The adhesive tape of the present invention is attached to the mirror surface of a 4-inch semiconductor wafer, and is peeled off after being exposed to an environment of 23° C. and a relative humidity of 50% for 1 hour. At this time, the particle size on the mirror surface is 0.28 μm or more. The number of particles is preferably from 0/cm ² to 500 /cm ² , more preferably from 0 /cm ² to 100 /cm ² , particularly preferably from 0 /cm ² to 50 /cm ² , most Preferably, it is 0 pieces/cm ² ~ 20 pieces/cm ² . The measurement of the number of particles can be carried out using a particle counter. Moreover, the adhesive tape of the present invention is attached to the mirror surface of the semiconductor wafer, and is peeled off after being exposed to an environment of 40° C. and a relative humidity of 50% for one day, and the amount of carbon atoms on the surface of the wafer is increased. The amount of the organic substance printed on the wafer is preferably from 1 atom% to 45 atom%, more preferably from 1 atom% to 30 atom%, before being attached to the adhesive tape. The amount of carbon atoms on the surface of the wafer can be measured using ESCA (Electron Spectroscopy for Chemical Analysis). Regarding the amount of carbon atoms on the surface of the wafer (ie, the amount of organic matter transferred onto the wafer), specifically, the amount of carbon atoms on the mirror surface of the semiconductor wafer to which the adhesive tape is not attached can be measured and The amount of carbon atoms on the mirror surface of the semiconductor wafer after being attached and peeled is calculated based on the difference therebetween. As the ESCA device, for example, a brand name "model 5400" manufactured by ULVAC-PHI Corporation can be used.

The adhesive tape of the present invention can be provided by a spacer. The adhesive tape of the present invention can be wound into a roll shape in a state protected by a separator. The spacer has the function of protecting the adhesive tape until it is supplied with a protective material before use. Examples of the separator include a plastic coated with a release agent such as a bismuth release agent, a fluorine release agent, or a long-chain alkyl acrylate release agent (for example, polyethylene terephthalate (PET). , polyethylene, polypropylene) film, non-woven fabric or paper.

The adhesive tape of the present invention may be subjected to back treatment on the outermost side opposite to the adhesive layer, for example, when it is not protected by the separator. The back surface treatment can be carried out, for example, by using a release agent such as a ruthenium release agent or a long-chain alkyl acrylate release agent. The adhesive tape of the present invention can be wound into a roll shape by performing back surface treatment.

B. Adhesive layer

The above adhesive layer is formed of a resin composition containing an amorphous propylene-(1-butene) copolymer. In the case of such an adhesive layer, an adhesive tape can be produced by co-extrusion molding with a base material layer, and an adhesive tape can be obtained with a small number of steps and without using an organic solvent. Furthermore, In the present specification, the term "amorphous" means a property which does not have a melting point as defined by crystallinity.

In the above amorphous propylene-(1-butene) copolymer, the content ratio of the constituent unit derived from 1-butene is preferably from 1% by weight to 40% by weight, more preferably from 2% by weight to 30% by weight, and furthermore It is preferably from 2% by weight to 10% by weight, particularly preferably from 2% by weight to 5% by weight. When it is such a range, 1-butene inhibits crystallization of propylene and remains amorphous, and is excellent in flexibility, so that an adhesive tape excellent in the above-described step followability can be obtained.

In the above amorphous propylene-(1-butene) copolymer, the content ratio of the constituent unit derived from propylene is preferably 60% by weight to 99% by weight, more preferably 70% by weight to 98% by weight, still more preferably 90% by weight. It is preferably from 95% by weight to 98% by weight, particularly preferably from 98% by weight to 98% by weight. When it is in this range, the adhesive layer is not too soft due to the increase in 1-butene and the molecular chain is enlarged, and the peeling can be stably performed when the tape is peeled off.

The above amorphous propylene-(1-butene) copolymer may be a block copolymer or a random copolymer.

The amorphous propylene-(1-butene) copolymer has a weight average molecular weight (Mw) of 200,000 or more, preferably 200,000 to 500,000, and more preferably 200,000 to 300,000. When the weight average molecular weight (Mw) of the amorphous propylene-(1-butene) copolymer is in this range, a low molecular weight component can be obtained as compared with a usual styrene-based thermoplastic resin or an acrylic thermoplastic resin (Mw is 100,000 or less). Less adhesive tape that prevents contamination by the adherend. Further, at the time of co-extrusion molding, the adhesive layer can be formed without processing, and an appropriate adhesive force can be obtained.

Further, the above-mentioned amorphous propylene-(1-butene) copolymer may contain constituent units derived from other monomers within a range not impairing the effects of the present invention. Examples of the other monomer include ethylene, 1-pentene, 1-hexene, 1-octene, 1-decene, 4-methyl-1-pentene, and 3-methyl-1-pentene. And other alpha-olefins.

The above amorphous propylene-(1-butene) copolymer is preferably propylene by using a metallocene catalyst. It is obtained by polymerization with 1-butene. For example, the amorphous propylene-(1-butene) copolymer can be subjected to a polymerization step of polymerizing propylene and 1-butene using a metallocene catalyst, a residual catalyst removal step after the polymerization step, and an impurity removal step. Obtained by the post-processing steps. The amorphous propylene-(1-butene) copolymer is obtained in the form of a powder, a granule or the like through these steps. Examples of the metallocene catalyst include a metallocene-supporting catalyst containing a metallocene compound and a metallocene uniformly mixed catalyst, and a particulate carrier on which a metallocene compound is supported.

The amorphous propylene-(1-butene) copolymer polymerized using a metallocene catalyst as described above exhibits a narrow molecular weight distribution. The molecular weight distribution (Mw/Mn) of the amorphous propylene-(1-butene) copolymer is preferably 2 or less, more preferably 1.1 to 2, still more preferably 1.2 to 1.9. The amorphous propylene-(1-butene) copolymer having a narrow molecular weight distribution has a small amount of low molecular weight components, so if such an amorphous propylene-(1-butene) copolymer is used, it can be prevented due to low molecular weight. The component oozes out and contaminates the adhesive tape of the adherend. Such an adhesive tape is suitably used, for example, for semiconductor wafer processing.

The resin composition preferably further contains a crystalline resin. By including a crystalline resin in the resin composition, the adhesion of the adhesive layer can be lowered (resulting in the adhesive force of the above adhesive tape). The crystalline resin is preferably a crystalline α-olefin-based resin, more preferably a homopolymer or a copolymer having crystallinity derived from a constituent unit of 1-butene, and more preferably a crystalline propylene-(1-butene). a copolymer or a crystalline ethylene-(1-butene) copolymer. These crystalline resins may be used singly or in combination of two or more. When a crystalline resin having a constituent unit derived from 1-butene is used, it is possible to suppress an increase in the elastic modulus of the adhesive layer caused by the addition of the crystalline resin (that is, to suppress a decrease in step followability), and to lower the adhesive. The adhesion of the layers.

The crystallinity of the crystalline resin is preferably 10% or more, and more preferably 20% or more. The degree of crystallinity can be representatively obtained by differential scanning calorimetry (DSC) or X-ray diffraction.

The crystalline resin is preferably borrowed in the same manner as the above amorphous propylene-(1-butene) copolymer. It is obtained by polymerization using a metallocene catalyst. When the crystalline resin obtained in this manner is used, it is possible to prevent the adherend from being contaminated by the bleeding of the low molecular weight component.

The weight ratio of the amorphous propylene-(1-butene) copolymer to the above crystalline resin (amorphous propylene-(1-butene) copolymer: crystalline resin) is preferably from 90:10 to 50:50. Further preferably, it is 90:10 to 60:40, and particularly preferably 90:10 to 70:30. If it is in this range, the hardness (storage modulus) of the adhesive layer can be adjusted to an appropriate range, and an adhesive tape which is more suitable for protecting the adhesion and step followability of the semiconductor wafer and having excellent peelability can be obtained. .

In the above resin composition, the total content of the constituent units derived from 1-butene is preferably 5% by weight or more, and more preferably 5% by weight to 40% by weight based on the total weight of the resin in the resin composition. More preferably, it is 5% by weight to 30% by weight, particularly preferably 5% by weight to 10% by weight, most preferably 8% by weight to 10% by weight. If it is in this range, the hardness (storage modulus) of the adhesive layer can be adjusted to an appropriate range, and an adhesive tape which is more suitable for protecting the adhesion and step followability of the semiconductor wafer and having excellent peelability can be obtained. . This effect is obtained by adjusting the total content ratio of the crystalline resin having a constituent unit derived from 1-butene and the constituent unit derived from 1-butene in the resin composition to the above range. It has become more prominent. In the present specification, the "total content ratio of the constituent units derived from 1-butene in the resin composition" means the total content ratio of the constituent units derived from 1-butene of all the resins in the resin composition. Specifically, in the above resin composition, a crystalline resin having a constituent unit derived from 1-butene (for example, crystalline propylene-(1-butene) is contained in addition to the crystalline propylene-(1-butene) copolymer. In the case of a copolymer or a crystalline ethylene-(1-butene) copolymer, it means that the constituent unit derived from 1-butene and the crystalline resin in the amorphous propylene-(1-butene) copolymer are derived from The total content ratio of the constituent units of 1-butene.

The melt flow rate of the above resin composition at 230 ° C and 2.16 kgf is preferably from 1 g/10 min to 50 g/10 min, more preferably from 5 g/10 min to 30 g/10 min, and particularly preferably 5 g/10 min. 20g/10 minutes. If the melt flow rate of the above resin composition is in this range, an adhesive having a uniform thickness can be formed by co-extrusion molding without processing. Floor. The melt flow rate can be measured by the method according to JIS K7210.

The storage modulus (G') of the above adhesive layer at 20 ° C is preferably 2.0 MPa or less, more preferably 0.5 MPa to 2.0 MPa, still more preferably 0.5 MPa to 1.8 MPa, and particularly preferably 0.5 MPa to 1.6 MPa. . If the storage modulus (G') of the above adhesive layer is in this range, the step followability suitable for protecting the semiconductor wafer can be obtained. When the adhesive tape of the present invention is used for protecting a semiconductor wafer, the unevenness of the semiconductor wafer pattern can be well filled, which can contribute to the excellent polishing precision of the back surface polishing of the semiconductor wafer, and can prevent the polishing process from being Contamination or damage to the semiconductor wafer caused by the infiltration of water. Further, when the storage modulus (G') is in the above range, an adhesive tape excellent in balance between adhesion and peelability can be obtained. More specifically, the adhesive tape of the present invention has a small balance between the adhesive force and the peeling property even if the storage modulus (G') of the adhesive layer is small as described above, the adhesive force is not excessively high. Such an adhesive tape can sufficiently protect the surface of the semiconductor wafer in the back grinding, and the above effects (excellent polishing precision, prevention of water penetration) can be obtained, and can be easily peeled off after the polishing process and the semiconductor wafer can be prevented. damaged. Such an adhesive layer having a low storage modulus (G') and a low adhesive force can be obtained, for example, by adjusting a crystalline resin having a constituent unit derived from 1-butene in the above resin composition. The adhesion of the adhesive layer, thereby suppressing the rise in the storage modulus (G') and reducing the adhesion. Further, the storage modulus (G') of the present invention can be measured by dynamic viscoelastic spectroscopy.

The indentation hardness of the above adhesive layer when pressed into the nanometer indenter by 1000 nm is preferably 0.8 MPa or more, further preferably 0.8 MPa to 3.5 MPa, particularly preferably 0.8 MPa to 3.0 MPa, and most preferably 0.8 MPa. 1.5MPa. If it is this range, an adhesive tape which is suitable for protecting the adhesion, peeling property, and step followability of a semiconductor wafer can be obtained. More specifically, if the indentation hardness of the nanoindenter pressed at 1000 nm is 0.8 MPa or more, it is possible to prevent the adhesive tape from following and firmly adhering to the minute unevenness of the wafer surface (for example, PI (Polyimide, Polyimide (protective film, nano-scale irregularities such as circuit patterns), and an adhesive tape excellent in peelability can be obtained. The above adhesive layer is particularly preferably a storage modulus (G') The range is described, and the indentation hardness when the nanoindenter is pressed into 1000 nm is in the above range. According to the present invention, an adhesive tape in which the entire adhesive layer is relatively soft but the surface of the adhesive layer is relatively hard can be obtained. The adhesive tape having such an adhesive layer has a step followability and adhesion suitable for protecting the semiconductor wafer. Further, the hardness obtained by the nanoindenter can be measured using a nanoindenter (for example, manufactured by HYSITRON Co., Ltd.).

Preferably, the adhesive layer does not substantially contain F ^- , Cl ^- , Br ^- , NO ₂ ^- , NO ₃ ^- , SO ₄ ^2- , Li ⁺ , Na ⁺ , K ⁺ , Mg ²⁺ , Ca ²⁺ , NH ⁴⁺ . The reason for this is that the ion can be prevented from contaminating the adherend. When the adhesive tape having such an adhesive layer is used for processing a semiconductor wafer, for example, disconnection or short circuit of the circuit is not caused. The adhesive layer not containing the above ions can be obtained, for example, by solution polymerization of an amorphous propylene-(1-butene) copolymer contained in the adhesive layer by using a metallocene catalyst as described above. In the solution polymerization using the metallocene catalyst, the amorphous propylene-(1-butene) copolymer can be purified by repeating precipitation separation (reprecipitation method) using a poor solvent different from the polymerization solvent, so that no An adhesive layer containing the above ions. In addition, in the present specification, "substantially does not include F ^- , Cl ^- , Br ^- , NO ₂ ^- , NO ₃ ^- , SO ₄ ² -, Li ⁺ , Na ⁺ , K ⁺ , Mg ²⁺ , Ca ²⁺ , NH ₄ ⁺ ” means that the detection limit is not reached in standard ion chromatography (for example, ion chromatography using Dionex, trade name “DX-320” or “DX-500”). Specifically, it means a case where F ^- , Cl ^- , Br ^- , NO ₂ ^- , NO ₃ ^- , SO ₄ ^2- and K ⁺ are respectively 0.49 μg or less, Li ⁺ and Na ⁺ with respect to 1 g of the adhesive layer. Each is 0.20 μg or less, and Mg ²⁺ and Ca ²⁺ are each 0.97 μg or less, and NH ₄ ⁺ is 0.5 μg or less.

The above adhesive layer may further contain other components within a range not impairing the effects of the present invention. Examples of the other component include an antioxidant, an ultraviolet absorber, a light stabilizer, a heat stabilizer, and an antistatic agent. The kind and amount of other ingredients can be appropriately selected depending on the purpose.

C. substrate layer

The above substrate layer may be formed of any suitable resin. Preferably coextrudable The thermoplastic resin is, for example, a polyethylene resin. Specific examples of the polyethylene-based resin include ethylene-vinyl acetate copolymer (EVA), ethylene-ethyl acrylate copolymer (EEA), ethylene-methacrylic acid copolymer (EMA), and styrene-ethylene- Butylene-styrene block polymer (SEBS), high molecular weight polyethylene (HDPE), low molecular weight polyethylene (LDPE), linear low molecular weight polyethylene (LLDPE), high density polyethylene, low density polyethylene, etc. .

The weight average molecular weight (Mw) of the above ethylene-vinyl acetate copolymer is preferably from 10,000 to 200,000, more preferably from 30,000 to 190,000. When the weight average molecular weight (Mw) of the ethylene-vinyl acetate copolymer is in this range, the base material layer can be formed without processing at the time of co-extrusion molding.

The melt flow rate of the resin forming the substrate layer at 190 ° C and 2.16 kgf is preferably 2 g/10 min to 20 g/10 min, more preferably 5 g/10 min to 15 g/10 min, and particularly preferably 7 g / 10 minutes~12g/10 minutes. When the melt flow rate of the ethylene-vinyl acetate copolymer is in this range, the base material layer can be formed by co-extrusion molding without processing.

The base material layer may further contain other components within a range that does not impair the effects of the present invention. As the other component, for example, the same components as those which may be included in the adhesive layer described in the above item B can be used.

D. Manufacturing method of adhesive tape

The adhesive tape of the present invention is preferably produced by co-extruding a material for forming the pressure-sensitive adhesive layer and the base material layer. By co-extrusion molding, an adhesive tape having good adhesion between layers can be produced with a small number of steps and without using an organic solvent. In the present specification, the term "forming material (adhesive layer forming material) of the adhesive layer" means a mixture of the above resin composition and the above other components.

In the above coextrusion molding, a material obtained by mixing the components of the above layers by any appropriate method may be used as the material for forming the pressure-sensitive adhesive layer and the base material layer.

As a specific method of the above-described co-extrusion molding, for example, in at least two extruders connected to a die, one of the adhesive layer forming materials is supplied to one, and the other base material layer is formed. The material was melted, extruded, and drawn by a contact roll forming method to form a laminate. When extruding, the portion where the respective forming materials merge is closer to the nozzle outlet (mould lip). The reason for this is that it is difficult to cause a poor joining force in each of the forming materials in the nozzle. Therefore, as the above-mentioned nozzle, a nozzle in the form of a multi-manifold is preferably used. Further, in the case where the merging failure occurs, the appearance unevenness such as merging unevenness occurs, and specifically, the appearance of the wavy appearance between the extruded adhesive layer and the substrate layer is uneven, which is not preferable. Further, the merging failure occurs, for example, because the difference in fluidity (melt viscosity) between the different kinds of material forming materials in the nozzle and the difference in the shear rate of the material forming the layers are large, so that the manifold type is used. The die mouth is wider for a different material forming material having a poor fluidity than other forms (for example, a feed module form). The type of screw used for the extruder for melting each of the formed materials may be a single screw or a twin screw. The extruder can also be three or more. When the number of extruders is three or more, the material for forming the other layers can be supplied. Further, when three or more extruders are used to produce an adhesive tape having a two-layer structure (base material layer + adhesive layer), the same forming material may be supplied to two or more adjacent extruders, for example, for example. In the case of using three extruders, the same forming material can be supplied to two adjacent extruders.

The forming temperature of the above coextrusion molding is preferably from 160 ° C to 220 ° C, more preferably from 170 ° C to 200 ° C. If it is this range, it is excellent in shaping|molding stability.

The difference between the adhesive layer forming material and the base material forming material at a temperature of 180 ° C and a shear rate of 100 sec ^-1 (adhesive forming material - base material forming material) is preferably -150 Pa. s~600Pa. s is below, and further preferably -100 Pa. s~550Pa. s, especially good for -50Pa. s~500Pa. s. When it is in this range, the fluidity of the adhesive forming material and the base material layer forming material in the nozzle can be made close to each other, and the occurrence of merging failure can be prevented. Further, the shear viscosity can be measured by a double capillary type elongational viscometer.

[Examples]

Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited by the examples. Further, the test and evaluation methods in the examples and the like are as follows. Further, the parts are parts by weight.

[Example 1]

As the adhesive layer forming material, an amorphous propylene-(1-butene) copolymer obtained by polymerizing using a metallocene catalyst (manufactured by Sumitomo Chemical Co., Ltd., trade name "Tafthren H5002", from 1-butyl is used. The constituent unit of the olefin: 2% by weight), and 10 parts of the crystalline propylene-(1-butene) copolymer (manufactured by Mitsui Chemicals, Inc., trade name "TAFMER XM7070", constituent unit derived from 1-butene: 34% by weight Resin composition (total content ratio of constituent units derived from 1-butene in the resin composition: 5.2% by weight).

As the base material forming material, an ethylene-vinyl acetate copolymer (manufactured by Mitsui DuPont, trade name "EVAFLEX P-1007") was used.

The adhesive forming material and the base layer forming material were placed in respective extruders, and T-die melt co-extrusion was performed (extruder: GM Engineering, trade name "GM30-28" / T type Mold nozzle: feed module method; extrusion temperature: 180 ° C), a molten PET resin and a Si coated PET separator that is passed through the contact roll forming section (Mitsubishi Chemical Co., Ltd., trade name "Diafoil MRF": 38 μm The laminate was laminated, and thereafter, cooling was carried out to obtain an adhesive tape having a thickness of the adhesive layer of 30 μm and a thickness of the substrate layer of 100 μm. The thickness of each layer is controlled by the shape of the T-die nozzle outlet.

[Embodiment 2]

As the adhesive layer forming material, 80 parts of an amorphous propylene-(1-butene) copolymer polymerized by a metallocene catalyst (manufactured by Sumitomo Chemical Co., Ltd., trade name "Tafthren H5002", from 1-butyl is used. The constituent unit of the olefin: 2% by weight), and 20 parts of the crystalline propylene-(1-butene) copolymer (manufactured by Mitsui Chemicals, Inc., trade name "TAFMER XM7070", constituent unit derived from 1-butene: 34% by weight Resin composition (resin group) An adhesive tape was obtained in the same manner as in Example 1 except that the total content of the constituent units derived from 1-butene was 8.4% by weight.

[Example 3]

As the adhesive layer forming material, 70 parts of an amorphous propylene-(1-butene) copolymer polymerized by a metallocene catalyst (manufactured by Sumitomo Chemical Co., Ltd., trade name "Tafthren H5002", from 1-butyl is used. A constituent unit of an olefin: 2% by weight), and 30 parts of a crystalline propylene-(1-butene) copolymer (manufactured by Mitsui Chemicals, Inc., trade name "TAFMER XM7070", constituent unit derived from 1-butene: 34% by weight In addition, the resin composition (the total content ratio of the constituent units derived from 1-butene in the resin composition: 11.6% by weight) has a thickness of the adhesive layer of 45 μm and a thickness of the base material layer of 160 μm. An adhesive tape was obtained in the same manner as in Example 1.

[Example 4]

As the adhesive layer forming material, 60 parts of an amorphous propylene-(1-butene) copolymer polymerized by a metallocene catalyst (manufactured by Sumitomo Chemical Co., Ltd., trade name "Tafthren H5002", from 1-butyl is used. A constituent unit of an olefin: 2% by weight), and 40 parts of a crystalline propylene-(1-butene) copolymer (manufactured by Mitsui Chemicals, Inc., trade name "TAFMER XM7070", a constituent unit derived from 1-butene: 34% by weight In addition, the resin composition (the total content ratio of the constituent units derived from 1-butene in the resin composition: 14.8% by weight) has a thickness of the adhesive layer of 45 μm and a thickness of the base material layer of 160 μm. An adhesive tape was obtained in the same manner as in Example 1.

[Example 5]

As the adhesive layer forming material, 80 parts of an amorphous propylene-(1-butene) copolymer polymerized by a metallocene catalyst (manufactured by Sumitomo Chemical Co., Ltd., trade name "Tafthren H5002", from 1-butyl is used. The constituent unit of the olefin: 2% by weight), and 20 parts of the crystalline ethylene-(1-butene) copolymer (manufactured by Mitsui Chemicals, Inc., trade name "TAFMER BL3450", constituent unit derived from 1-butene: 87% by weight Resin composition (resin combination) In the same manner as in Example 1, except that the total content of the constituent units derived from 1-butene was 19% by weight, and the thickness of the adhesive layer was 45 μm, and the thickness of the base material layer was 160 μm. Get an adhesive tape.

[Embodiment 6]

As the adhesive layer forming material, 70 parts of an amorphous propylene-(1-butene) copolymer polymerized by a metallocene catalyst (manufactured by Sumitomo Chemical Co., Ltd., trade name "Tafthren H5002", from 1-butyl is used. The constituent unit of the olefin: 2% by weight), and 30 parts of a crystalline ethylene-(1-butene) copolymer (manufactured by Mitsui Chemicals, Inc., trade name "TAFMER BL3450", constituent unit derived from 1-butene: 87% by weight An adhesive tape was obtained in the same manner as in Example 1 except that the resin composition (the total content ratio of the constituent units derived from 1-butene in the resin composition: 27.5 wt%) was used.

[Embodiment 7]

As the adhesive layer forming material, 60 parts of an amorphous propylene-(1-butene) copolymer polymerized by a metallocene catalyst (manufactured by Sumitomo Chemical Co., Ltd., trade name "Tafthren H5002", from 1-butyl is used. The constituent unit of the olefin: 2% by weight), and 40 parts of the crystalline ethylene-(1-butene) copolymer (manufactured by Mitsui Chemicals, Inc., trade name "TAFMER BL3450", constituent unit derived from 1-butene: 87% by weight An adhesive tape was obtained in the same manner as in Example 1 except that the resin composition (the total content ratio of the constituent units derived from 1-butene in the resin composition: 36% by weight) was used.

[Comparative Example 1]

As the adhesive layer forming material, an amorphous propylene-(1-butene) copolymer obtained by polymerization using 100 parts of a metallocene catalyst (manufactured by Sumitomo Chemical Co., Ltd., trade name "Tafthren H5002", from 1-butyl is used. Adhesive in the same manner as in Example 1 except that the resin composition (2% by weight) of the resin composition (the total content of the constituent units derived from 1-butene in the resin composition: 2% by weight) was used. band.

[Comparative Example 2]

As the adhesive layer forming material, an amorphous propylene-(1-butene) copolymer obtained by polymerizing using a metallocene catalyst (manufactured by Sumitomo Chemical Co., Ltd., trade name "Tafthren H5002", from 1-butyl is used. A resin composition (resin composition) of a crystalline polypropylene resin (manufactured by Japan Polypropylene Co., Ltd., trade name "WINTEC WFX4") obtained by polymerization of a metallocene catalyst (2% by weight) An adhesive tape was obtained in the same manner as in Example 1 except that the total content of the constituent units derived from 1-butene was 1.8% by weight.

[Comparative Example 3]

As the adhesive layer forming material, 80 parts of an amorphous propylene-(1-butene) copolymer polymerized by a metallocene catalyst (manufactured by Sumitomo Chemical Co., Ltd., trade name "Tafthren H5002", from 1-butyl is used. A resin composition (resin composition) of a crystalline polypropylene resin (manufactured by Japan Polypropylene Co., Ltd., trade name "WINTEC WFX4") obtained by polymerization of a metallocene catalyst (2% by weight) An adhesive tape was obtained in the same manner as in Example 1 except that the total content of the constituent units derived from 1-butene was 1.6% by weight.

[Comparative Example 4]

As the adhesive layer forming material, 70 parts of an amorphous propylene-(1-butene) copolymer polymerized by a metallocene catalyst (manufactured by Sumitomo Chemical Co., Ltd., trade name "Tafthren H5002", from 1-butyl is used. A resin composition (resin composition) of a crystalline polypropylene resin (manufactured by Japan Polypropylene Co., Ltd., trade name "WINTEC WFX4") obtained by polymerizing a metallocene catalyst by polymerization of 2% by weight) An adhesive tape was obtained in the same manner as in Example 1 except that the total content of the constituent units derived from 1-butene was 1.4% by weight.

[Evaluation]

The adhesive tapes obtained in the examples and the comparative examples were subjected to the following evaluations. The results are shown in Table 1.

(1) Indentation hardness

The indentation hardness of the adhesive layer was measured by using a nanoindenter (manufactured by HYSITRON Co., Ltd.) at a room temperature of 25 ° C to press the triangular pyramid indenter against the surface of the adhesive at a speed of 100 nm/sec to 1000 nm. The load μN (Pmax) was calculated by the following formula.

Indentation hardness = (Pmax) / A; contact projected area

(2) Storage modulus (G')

The storage modulus of the adhesive layer at 20 ° C can be measured by a dynamic spectrometer (manufactured by Rheometric Scientific, trade name "ARES") at a frequency of 10 Hz, a temperature increase rate of 5 ° C / min, and a range of -50 ° C to 100 ° C. The measurement was carried out.

(3) Adhesion (opposite)

The obtained adhesive tape was measured on the mirror surface of the 4-inch semiconductor wafer by the method according to JIS Z 0237 (2000) (adhesion conditions: 1 kg roller reciprocating once, peeling speed: 300 mm/min, peeling angle: 180°) The adhesion of the system.

(4) Adhesion (for polyimine)

The adhesive tape on the polyimine coated wafer was measured by the method according to JIS Z 0237 (2000) (adhesion conditions: 1 kg roller reciprocating once, peeling speed: 300 mm/min, peeling angle: 180°) The adhesion of the bismuth imide coated surface.

(5) Step followability (floating width)

An aluminum plate having a thickness of 30 μm and a width of 2 cm was placed on a 8-inch semiconductor wafer. The adhesive tape was attached to the aluminum plate by means of a tape attachment device DR-3000II (manufactured by Nitto Seiki Co., Ltd.), and the floating width with respect to a step of 30 μm was observed with a microscope and measured.

(6) Stripping

The adhesive tape was attached to a 8-inch semiconductor wafer (manufactured by Nippon Seiki Co., Ltd.) using a back-grinding device DFG 8560 (manufactured by DISCO Co., Ltd.) and ground to 100 μm. Stripped. Will be able to peel off once ○, the person who could not be peeled off was denoted by ×, and the evaluation was performed.

According to the embodiment, it is clear that according to the present invention, an adhesive tape having excellent balance of adhesion and peelability and excellent step followability can be obtained.

[Industrial availability]

The adhesive tape of the present invention can be suitably used, for example, to protect a workpiece (semiconductor wafer or the like) at the time of manufacture of a semiconductor device.

10‧‧‧Adhesive layer

20‧‧‧Substrate layer

100‧‧‧Adhesive tape

Claims (8)

An adhesive tape comprising an adhesive layer composed of a resin composition comprising an amorphous propylene-(1-butene) copolymer, and the adhesive tape is attached to an adherend having a step of 30 μm The vicinity of the step is floated, and the width of the portion where the adhesive tape does not contact the adherend is 650 μm or less, and the method according to JIS Z 0237 (2000) is used. (Adhesion conditions: 1 kg roller reciprocating once, peeling speed : 300 mm / min, peeling angle: 180 °) The adhesion of the adhesive tape to the tantalum semiconductor mirror wafer was 2.0 N/20 mm or less. The adhesive tape of claim 1, wherein the storage modulus (G') of the adhesive layer at 20 ° C is 2.0 MPa or less. The adhesive tape of claim 1 or 2, wherein the adhesive layer has an indentation hardness of 0.8 MPa or more when pressed by a nanoindenter at 1000 nm. The adhesive tape according to claim 1 or 2, wherein the resin composition comprises an amorphous propylene-(1-butene) copolymer and a crystalline resin, and the crystalline resin is a crystalline propylene-(1-butene) copolymer. And/or crystalline ethylene-(1-butene) copolymer. The adhesive tape of claim 1 or 2, wherein the total content of the constituent units derived from 1-butene in the resin composition is 5% by weight or more based on the total weight of the resin in the resin composition. The adhesive tape of claim 1 or 2, wherein the adhesive tape has a thickness of 5 μm to 1000 μm. The adhesive tape of claim 1 or 2 further comprising a base material layer, and the adhesive layer forming material and the base material layer forming material are co-extruded. The adhesive tape of claim 1, which is used for semiconductor wafer processing.