JP2012109585A - Tape for semiconductor processing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tape for semiconductor processing, which is stuck to a semiconductor to protect the semiconductor in semiconductor processing having a reduced pressure heating step.SOLUTION: A tape for semiconductor processing, which is stuck to a semiconductor to protect the semiconductor in semiconductor processing having a reduced pressure heating step, comprises an adhesive agent layer on at least one surface of a base material, the layer containing silica fine particles of 7-20 pts.mass with respect to a photocuring type adhesive agent of 100 pts.mass. The silica fine particles are dispersed in the adhesive agent layer so as to have an average particle diameter of 0.9 μm or less and a maximum particle diameter of 5.0 μm or less.

Description

The present invention is a double-sided adhesive tape for semiconductor processing used for reinforcing a semiconductor wafer by bonding a semiconductor wafer and a support plate at the time of manufacturing an IC chip, and it is easy and reliable by applying a stimulus. The present invention relates to a double-sided adhesive tape for semiconductor processing that can be peeled between a double-sided adhesive tape for processing and a support plate. The present invention also relates to a semiconductor processing tape for sticking to a semiconductor to protect it during processing of the semiconductor having a reduced pressure heating process.

In the manufacturing process of an IC chip, when a thick film semiconductor wafer cut out from a high-purity silicon single crystal or the like is ground to a predetermined thickness to form a thin film semiconductor wafer, the semiconductor wafer is bonded to a support plate and reinforced. Therefore, a method for efficiently performing the work has been proposed. At this time, the double-sided pressure-sensitive adhesive tape for bonding the semiconductor wafer and the support plate firmly adheres during the grinding process, but can be peeled off from the support plate without damaging the obtained thin film wafer after the grinding process is completed. Is required. In particular, in recent years, complex circuits have been formed on the surface of IC chips, and circuit wafers with extremely uneven surfaces have been manufactured. It has been strongly demanded to achieve both easy peeling.

As a method for peeling off the adhesive tape, for example, it may be considered that the adhesive tape is peeled off by applying a physical force. However, this method may cause serious damage when the adherend is soft. Moreover, the method of peeling an adhesive tape using the solvent which can melt | dissolve an adhesive is also considered. However, this method cannot be used when the adherend is attacked by a solvent.
As described above, the pressure-sensitive adhesive tape once used for bonding has a problem that it is more difficult to peel off the adherend without damaging the adherend as the adhesive strength is stronger.

On the other hand, Patent Document 1 discloses that a semiconductor wafer is supported on a support plate via a double-sided adhesive tape having an adhesive layer containing a gas generating agent that generates gas by irradiating light into a photocurable adhesive. An IC chip manufacturing method is disclosed in which a semiconductor wafer is ground in this state. When such a double-sided pressure-sensitive adhesive tape is irradiated with light, the pressure-sensitive adhesive is cured by light irradiation and the elastic modulus is increased, while gas is generated from the gas generating agent. The gas generated in the pressure-sensitive adhesive layer having an increased elastic modulus is released from the pressure-sensitive adhesive layer with high efficiency and peels at least a part of the adhesive surface. Therefore, when such a double-sided pressure-sensitive adhesive tape is used, even when producing an extremely thin IC chip that is very easily damaged, by irradiating the double-sided pressure-sensitive adhesive tape with light, the wafer can be easily and without being damaged. The double-sided adhesive tape can be peeled off.

In the double-sided pressure-sensitive adhesive tape described in Patent Document 1, it is described that an azo compound is particularly preferable as a gas generating agent. This is because the azo compound is extremely easy to handle, does not cause a chain reaction and does not explosively generate gas, so there is no danger of damaging the adherend, and if UV irradiation is interrupted, it will be a gas. This is because there are various advantages such as the ability to control the adhesiveness in accordance with the use because the generation of the ink can be interrupted. However, since the azo compound is decomposed by heat of about 150 ° C., it is not always sufficient in terms of heat resistance. For example, in the above-described IC chip manufacturing method, a metal thin film forming step or the like by sputtering is recently performed, and it is not uncommon for the surface temperature of the wafer to exceed 150 ° C. in such a step. When going through such a high temperature process, the conventional adhesive tape using an azo compound may not exhibit the desired peelability.

On the other hand, Patent Document 1 also describes an azide compound as a gas generating agent. Patent Document 2 also describes a highly peelable adhesive for fixing a semiconductor containing an azide compound. Since an azide compound is superior in heat resistance as compared with an azo compound, it was expected that sufficient release performance could be obtained even if it was used for an application having a high temperature process if an azide compound was used. However, in practice, there is a problem that sufficient peeling performance cannot be obtained even when an azide compound is used.

In the manufacture of semiconductors, a semiconductor processing tape is applied to facilitate handling of the semiconductor during processing and prevent damage. For example, when a thick film wafer cut out from a high-purity silicon single crystal or the like is ground to a predetermined thickness to form a thin film wafer, a double-sided adhesive tape is used to reinforce the thick film wafer by bonding it to a support plate. Used. An adhesive tape called a dicing tape is also used when dicing a thin film wafer ground to a predetermined thickness into individual IC chips.

The tape for semiconductor processing is required to have high adhesiveness capable of firmly fixing the semiconductor during the processing step and to be able to be peeled off after the step without damaging the semiconductor. On the other hand, Patent Document 3 discloses a pressure-sensitive adhesive tape using a photo-curing pressure-sensitive adhesive that is cured by irradiating light such as ultraviolet rays and has reduced adhesive strength. Such an adhesive tape can reliably fix the semiconductor during the processing step and can be easily peeled off by irradiating with ultraviolet rays or the like.

In recent years, due to the diversification of semiconductor mounting methods, there are an increasing number of processes in which a wafer is heated under high pressure with an adhesive tape attached. Examples of the treatment having such a reduced pressure heating step include chemical vapor deposition, physical vapor deposition, sputtering, dry etching, and plating. However, when a pressure-sensitive adhesive tape using a conventional photocurable pressure-sensitive adhesive is used during processing of a semiconductor having a reduced pressure heating process, there is a problem that it may be peeled off even before irradiation with ultraviolet rays or the like. . Such peeling was particularly noticeable when irregularities such as circuits were formed on the non-contact surface.

JP 2003-231872 A JP 2001-200274 A JP-A-5-32946

The present invention is a double-sided adhesive tape for semiconductor processing used for reinforcing a semiconductor wafer by bonding a semiconductor wafer and a support plate at the time of manufacturing an IC chip, and it is easy and reliable by applying a stimulus. It aims at providing the double-sided adhesive tape for semiconductor processing which can peel between the double-sided adhesive tape for processing, and a support plate. Another object of the present invention is to provide a semiconductor processing tape for sticking to a semiconductor to protect it during processing of the semiconductor having a reduced pressure heating process.

1st this invention is the double-sided adhesive tape for semiconductor processing used in order to reinforce a semiconductor wafer by adhere | attaching a semiconductor wafer and a support plate at the time of manufacture of an IC chip, Comprising: A pressure-sensitive adhesive layer formed on both sides, the pressure-sensitive adhesive layer on the side that adheres to the support plate contains a gas generating agent that generates gas by stimulation, and the side that adheres to the support plate When the substrate on the side in contact with the pressure-sensitive adhesive layer is subjected to a dot-like release treatment, the diameter of the dots subjected to the release treatment is x, and the number of dots per 1 cm ² is y. And y are double-sided pressure-sensitive adhesive tapes for semiconductor processing in a range surrounded by broken lines A, B and C in FIG.

According to a second aspect of the present invention, there is provided a semiconductor processing tape for attaching to a semiconductor to protect the semiconductor at the time of processing the semiconductor having a reduced pressure heating process. It has a pressure-sensitive adhesive layer containing 7 to 20 parts by mass of silica fine particles with respect to 100 parts by mass of the curable pressure-sensitive adhesive, and the silica fine particles have an average particle size of 0.9 μm or less and a maximum particle size. It is the tape for semiconductor processing currently disperse | distributed in the said adhesive layer so that it may become 5.0 micrometers or less.
The present invention is described in detail below.

The double-sided pressure-sensitive adhesive tape for semiconductor processing of the first invention will be described in detail.
The present inventors examined the stress applied to the wafer when the wafer bonded with the double-sided adhesive tape and the support plate were peeled off. As a result, it was concluded that the stress is most applied to the wafer when the rigid bodies of the wafer and the support plate are separated from each other. At the time of peeling, if the double-sided pressure-sensitive adhesive tape and the support plate can be peeled first, the remaining flexible double-sided pressure-sensitive adhesive tape can be peeled off from the wafer so that the wafer is hardly damaged at the time of peeling.
In order to peel the wafer and the support plate first in this manner, for example, it is conceivable that only the pressure-sensitive adhesive layer on the side to be bonded to the support plate of the double-sided pressure-sensitive adhesive tape contains a gas generating agent. However, it has been found that in many cases, the support plate cannot actually be peeled off even when gas is generated from the gas generating agent by stimulating the wafer and the support plate bonded with such a double-sided adhesive tape. This is considered to be because once the support plate is peeled off due to the generation of gas, it cannot be peeled again due to the weight of the support plate itself (hereinafter also referred to as “re-adhesion”). It was.

As a result of further intensive studies, the inventors give a stimulus by applying a dot-like mold release treatment to the base material in contact with the pressure-sensitive adhesive layer containing the gas generating agent on the side to be bonded to the support plate. As a result, the present inventors have found that the support plate can be surely peeled off only by mere completion of the present invention.
The support plate peeling mechanism when the double-sided pressure-sensitive adhesive tape for semiconductor processing of the first invention (hereinafter also simply referred to as “double-sided pressure-sensitive adhesive tape”) is used will be described in detail with reference to the drawings.

FIG. 1 is a schematic diagram when stimulation (light) is applied to a support plate and a semiconductor wafer bonded using a double-sided pressure-sensitive adhesive tape having a pressure-sensitive adhesive layer containing a gas generating agent on the side to be bonded to a conventional support plate. FIG. In FIG. 1A, the semiconductor wafer 1 and the support plate 2 are bonded via a double-sided adhesive tape 3. Here, the double-sided pressure-sensitive adhesive tape 3 has a pressure-sensitive adhesive layer 32 and a pressure-sensitive adhesive 33 formed on both surfaces of a base material 31, and the pressure-sensitive adhesive layer 32 on the side to be bonded to the support plate generates gas by light irradiation. Contains a gas generating agent. When such a laminate is irradiated with light, gas is generated from the gas generating agent contained in the pressure-sensitive adhesive layer 32. The generated gas tends to go out of the pressure-sensitive adhesive layer 32. However, since the adhesive force between the base material and the pressure-sensitive adhesive layer is usually higher than the adhesive force between the base material and the support plate, most of the gas is Released to the adhesive interface between the substrate and the support plate. At least a part of the adhesive interface between the substrate and the support plate is peeled off by the pressure of the released gas, and the support plate is peeled off (FIG. 1 (b)). However, once peeled off, the support plate itself is brought into close contact (re-adhesion) with the pressure-sensitive adhesive layer and cannot be peeled off (FIG. 1 (c)).

FIG. 2 is a schematic view when stimulation (light) is applied to the support plate and the semiconductor wafer bonded using the double-sided pressure-sensitive adhesive tape of the present invention. In FIG. 2A, the semiconductor wafer 1 and the support plate 2 are bonded via a double-sided adhesive tape 4. Here, the double-sided pressure-sensitive adhesive tape 4 has a pressure-sensitive adhesive layer 42 and a pressure-sensitive adhesive 43 formed on both surfaces of a base material 41, and the pressure-sensitive adhesive layer 42 on the side to be bonded to the support plate generates gas by light irradiation. Contains a gas generating agent. The base material 41 on the side in contact with the pressure-sensitive adhesive layer 42 is subjected to a release process in a dot shape (release process unit 411). In this respect, it differs from the conventional double-sided pressure-sensitive adhesive tape.
When such a laminate is irradiated with light, gas is generated from the gas generating agent contained in the pressure-sensitive adhesive layer 42. The generated gas tends to go out of the pressure-sensitive adhesive layer 42, and the gas is released to the adhesive interface between the base material and the support plate as in the conventional case, and the pressure between the base material and the support plate is released by the pressure of the released gas. At least a part of the adhesive interface is peeled off and the support plate is peeled off. On the other hand, a release processing part 411 is provided between the base material 41 and the pressure-sensitive adhesive layer 42, and the adhesive strength of this part is inferior to the surroundings. Therefore, the gas generated from the pressure-sensitive adhesive layer 42 is also released to the peeling processing unit 411. As a result, an air reservoir 5 is formed at a portion corresponding to the mold release processing unit 411 at the interface between the base material 41 and the adhesive layer 42, and the adhesive layer 42 changes to a waved shape due to the presence of the air reservoir 5. (FIG. 2B). Even if the support plate once peeled tries to adhere to the pressure-sensitive adhesive layer again due to its own weight, it cannot be sufficiently adhered to such a wavy shaped pressure-sensitive adhesive layer, and thus easily without re-adhesion. It can peel (FIG.2 (c)).

The double-sided pressure-sensitive adhesive tape of the present invention comprises a substrate and an adhesive layer formed on both surfaces of the substrate.
Although the said base material is not specifically limited, It is preferable that it is what permeate | transmits or passes light, for example, transparent, such as an acryl, an olefin, a polycarbonate, vinyl chloride, ABS, polyethylene terephthalate (PET), nylon, urethane, a polyimide. Examples thereof include a sheet made of resin, a sheet having a network structure, and a sheet having holes.
The base material may be subjected to a treatment for improving the adhesion with the pressure-sensitive adhesive layer such as a corona treatment.

The surface on the side in contact with the pressure-sensitive adhesive layer on the side to be bonded to the support plate of the substrate is subjected to a dot-like mold release treatment.
In this specification, the mold release process includes all processes for forming a region having low adhesive force or adhesive force with respect to the surroundings.
In addition, the dot shape means that the dots (points) of the release processing part are regularly or randomly distributed over substantially the entire surface of the substrate.
Although the schematic diagram showing the example of a dot-shaped mold release process was shown to Fig.3 (a) (b), this invention is not limited only to these examples.
The shape of the dots (points) is not particularly limited, and may be any shape such as a circle, a triangle, a quadrangle, or a star.

The lower limit of the dot (point) diameter is 0.5 mm, and the upper limit is 3.0 mm. If the diameter of the dots (dots) is less than 0.5 mm, the pressure-sensitive adhesive layer does not have a wavy shape even if stimulation is applied, and re-adhesion cannot be prevented. If the diameter of the dots (dots) exceeds 3.0 mm, the air pocket formed will be large, the waved shape of the pressure-sensitive adhesive layer will become loose, and re-adhesion cannot be prevented sufficiently, or the pressure-sensitive adhesive layer will be Adhering to the side may cause glue residue.

In the double-sided pressure-sensitive adhesive tape of the present invention, the effect that the double-sided pressure-sensitive adhesive tape and the support plate can be easily and reliably peeled off by giving a stimulus is the diameter of dots (points) subjected to the above release treatment per x 1 cm ^2. This is exhibited only when x and y are within a certain range, where y is the number of dots (points).

For example, when the diameter of a dot (point) is 0.5 mm, the lower limit of the number of dots (points) per 1 cm ² is 1, and the upper limit is 12. When the number of dots (dots) per 1 cm ² is less than 1, even if stimulation is applied, the pressure-sensitive adhesive layer does not have a wavy shape and re-adhesion cannot be prevented. If the number of dots (dots) per 1 cm ² exceeds 12, the adhesive layer may adhere to the wafer side.

When the diameter of a dot (point) is 1.0 mm, the lower limit of the number of dots (points) per 1 cm ² is 1, and the upper limit is 6.
When the diameter of dots (points) is 1.5 mm, the lower limit of the number of dots (points) per 1 cm ² is 1, and the upper limit is 4.
When the diameter of the dots (points) is 2.0 mm, the lower limit of the number of dots (points) per 1 cm ² is 1, and the upper limit is 3.
When the diameter of the dots (points) is 2.5 mm, the lower limit of the number of dots (points) per 1 cm ² is 1, and the upper limit is 2.
When the diameter of dots (points) is 3.0 mm, the lower limit of the number of dots (points) per 1 cm ² is one and the upper limit is one.

FIG. 4 shows the relationship between the diameter x of the dots subjected to the release treatment and the number y of dots per cm ² . In FIG. 4, “○” indicates that the double-sided pressure-sensitive adhesive tape and the support plate can be easily and reliably peeled off by giving a stimulus. Is plotted with “×”. Accordingly, the double-sided pressure-sensitive adhesive tape and the support plate can be easily and reliably peeled by giving a stimulus only when x and y are within the range surrounded by the broken lines A, B and C in FIG. I understand.
Within the range surrounded by the broken line A, the broken line B, and the broken line C, 0.5 ≦ x ≦ 3.0, y ≧ 1, and the range satisfying the following formula.
y ≦ 18-12x (0.5 ≦ x ≦ 1.0)
y ≦ 10-4x (1.0 ≦ x ≦ 1.5)
y ≦ 7-2x (1.5 ≦ x ≦ 3.0)

The method for performing the dot-shaped release treatment is not particularly limited, but a method of treating the release agent by a printing method such as gravure printing is simple and preferable.
The release agent is not particularly limited, and for example, a silicon-based, long-chain alkyl-based, or fluorine-based release agent can be used.
Examples of the long-chain alkyl release agent include Pyroyl 1050 and Pyroyl 406 manufactured by Otsuka Oil Co., Ltd.
Examples of the silicon release agent include KM722T and KF412SP manufactured by Shin-Etsu Chemical Co., Ltd.
Examples of the fluorine-based mold release agent include EGC-1720 manufactured by 3M, and die-free manufactured by Nihon Kasei Co., Ltd.
In addition to the method using a mold release agent, there may be mentioned a method of performing a corona treatment after masking in a dot shape when performing an adhesion improving treatment such as a corona treatment on a PET base material.

The pressure-sensitive adhesive layer on the side that adheres to the support plate in the pressure-sensitive adhesive layer (hereinafter also referred to as “support-plate-side pressure-sensitive adhesive layer”) contains a gas generating agent that generates gas upon stimulation.
A conventionally well-known thing can be used for the adhesive which comprises the said support plate side adhesive layer.
The gas generating agent is not particularly limited, and examples thereof include azo compounds and azide compounds.

The pressure-sensitive adhesive constituting the support-plate-side pressure-sensitive adhesive layer is particularly required to have high heat resistance when used for the purpose of bonding and protecting the support plate when subjected to processing including a high-temperature process such as sputtering. Is done. Such a support plate-side pressure-sensitive adhesive layer excellent in heat resistance has, for example, a (meth) acrylic type having no reactive double bond having an acid value of 25 mgKOH / g or less and a hydroxyl value of 25 mgKOH / g or less. It is preferable to contain a resin and an azide compound having a weight loss of 5% or less when held at 150 ° C. for 1 hour by TG-DTA measurement and having a gel fraction of 75 to 100%.
Below, the support board side adhesive layer excellent in such heat resistance is demonstrated in detail.

The (meth) acrylic resin used for the support plate-side pressure-sensitive adhesive layer preferably has an acid value of 25 mgKOH / g or less. When the acid value exceeds 25 mgKOH / g, the adhesive force of the pressure-sensitive adhesive layer increases due to heating, and thus the adhesive force may not be sufficiently reduced even if gas is generated.
In this specification, the acid value is a value that can be measured by a method based on JIS K 6751, and is used to neutralize the acid contained in 1 g of the (meth) acrylic resin. It means the weight of KOH required.

The (meth) acrylic resin used for the support plate-side pressure-sensitive adhesive layer preferably has a hydroxyl value of 25 mgKOH / g or less. When the hydroxyl value exceeds 25 mgKOH / g, the adhesive strength of the pressure-sensitive adhesive layer increases due to heating, and thus the adhesive strength may not be sufficiently reduced even if gas is generated.
In the present specification, the hydroxyl value is a value that can be measured by a method in accordance with JIS K 0070, and is a value of KOH corresponding to the amount of hydroxyl group contained in 1 g of the (meth) acrylic resin. Means weight.

The (meth) acrylic resin used for the support plate-side pressure-sensitive adhesive layer preferably does not have a functional group having a reactive double bond in the side chain. By using such a (meth) acrylic resin, gas can be generated at a desired time without hindering the gas generation performance of the azide compound.

The (meth) acrylic resin used for the support plate-side pressure-sensitive adhesive layer preferably does not have a polymerizable reactive group such as a double bond. When it has a polymerizable reactive group, the polymerizable reactive group and the azide compound react to consume the azide compound, so that it may be difficult to generate a gas at a desired time. .

The (meth) acrylic resin used for the support-plate-side pressure-sensitive adhesive layer is not particularly limited as long as it has the above-mentioned predetermined acid value and hydroxyl value. For example, as a polymer having adhesiveness at room temperature, As in the case of the (meth) acrylic polymer, an acrylic acid alkyl ester and / or methacrylic acid alkyl ester in which the alkyl group usually has 2 to 18 carbon atoms as a main monomer, a functional group-containing monomer, and further necessary Correspondingly, functional group-containing (meth) acrylic polymers obtained by copolymerizing these with other modifying monomers copolymerizable with a conventional method can be mentioned. Especially, the functional group containing (meth) acrylic polymer whose carbon number of an alkyl group is 6 or more is preferable. The weight average molecular weight of the functional group-containing (meth) acrylic polymer is usually about 200,000 to 2,000,000.

The azide compound preferably has a weight loss of 5% or less when held at 150 ° C. for 1 hour by TG-DTA (thermogravimetric-differential thermal analysis) measurement. If it exceeds 5%, the azide compound is consumed during heating and gas is generated, which may make it difficult to generate gas at a desired time.
In this specification, the weight loss when the TG-DTA measurement is held at 150 ° C. for 1 hour is 5% or less means that the azide compound alone is heated from 35 ° C. to 150 ° C. at a rate of 10 ° C./min. It is said that the amount of weight loss from the time when the temperature reaches 150 ° C. to the time when 1 hour elapses is 5% or less.

The azide compound is not particularly limited as long as it has the above-described weight reduction amount. For example, 3-azidomethyl-3-methyloxetane, terephthalazide, p-tert-butylbenzazide, 3-azidomethyl-3-methyl, and the like. Examples thereof include polymers having an azide group such as glycidyl azide polymer (GAP) obtained by ring-opening polymerization of oxetane. These azide compounds generate nitrogen gas mainly by irradiating light in the ultraviolet region with a wavelength of 400 nm or less.

The azide compound is preferably dissolved in the support plate-side pressure-sensitive adhesive layer. When the azide compound is dissolved in the pressure-sensitive adhesive layer, the gas generated from the azide compound is efficiently released out of the pressure-sensitive adhesive layer when stimulation is applied. When the azide compound is present as particles in the pressure-sensitive adhesive layer, the pressure-sensitive adhesive layer foams and gas is not released out of the pressure-sensitive adhesive layer, or at the particle interface when light is irradiated as a stimulus for generating gas. Light may scatter and gas generation efficiency may become low, or the surface smoothness of an adhesive layer may worsen.
In addition, it can confirm that the particle | grains of an azide compound are not found when observing an adhesive layer with an electron microscope that the said azide compound is melt | dissolving in an adhesive layer.

In order to dissolve the azide compound in the support plate-side pressure-sensitive adhesive layer, an azide compound dissolved in the pressure-sensitive adhesive constituting the support plate-side pressure-sensitive adhesive layer may be selected. When an azide compound that does not dissolve in the pressure-sensitive adhesive is selected, for example, it is preferable to disperse the azide compound as finely as possible in the pressure-sensitive adhesive layer by using a disperser or using a dispersant together. In order to finely disperse the azide compound in the pressure-sensitive adhesive layer, the gas generating agent is preferably fine particles. Further, these fine particles are used as necessary using, for example, a disperser or a kneading apparatus. It is preferable to use finer particles. That is, it is more preferable to disperse the gas generating agent to a state where it cannot be confirmed when the pressure-sensitive adhesive layer is observed with an electron microscope.

Although content of the said azide compound is not specifically limited, The preferable minimum with respect to 100 mass parts of said (meth) acrylic-type resins is 1 mass part, and a preferable upper limit is 200 mass parts. If it is less than 1 part by mass, sufficient peeling pressure may not be obtained and peeling may not be possible. If it exceeds 200 parts by mass, the physical properties of the adhesive may be adversely affected. A more preferred lower limit is 3 parts by mass, and a more preferred upper limit is 100 parts by mass.

In addition to the above components, the support plate-side pressure-sensitive adhesive layer may be blended with general pressure-sensitive adhesives such as isocyanate compounds, melamine compounds, and epoxy compounds as desired for the purpose of adjusting the cohesive force as a pressure-sensitive adhesive. These polyfunctional compounds may be appropriately blended. In addition, known additives such as an antistatic agent, a plasticizer, a resin, a surfactant, a wax, and a fine particle filler can be added.
Moreover, in order to improve stability of resin, you may mix | blend a heat stabilizer and antioxidant. Examples of such additives include phenol-based antioxidants, amine-based antioxidants, sulfur-based antioxidants, phosphorus-based antioxidants, organotin-based stabilizers, lead-based stabilizers, and the like. These additives may be used independently and 2 or more types may be used together.

The support plate-side pressure-sensitive adhesive layer may further contain a photosensitizer for the purpose of amplifying light stimulation to the azide compound. By blending such a photosensitizer, gas can be released by irradiation with less light. In addition, since a gas can be released by light in a wider wavelength region by blending a photosensitizer, the adherend does not transmit light having a wavelength that generates gas from an azide compound such as polyamide. However, gas can be generated by irradiating light through the adherend, and the range of selection of the adherend is widened.
Although the said photosensitizer is not specifically limited, For example, a thioxanthone sensitizer etc. are suitable.

The support plate side pressure-sensitive adhesive layer has a preferable lower limit of the gel fraction of 75%. If it is less than 75%, the pressure-sensitive adhesive layer itself foams when gas is generated, and it may be difficult to release the generated gas to the bonding interface with high efficiency.
In the present specification, the gel fraction means the content of the gel. For example, the weight of the (meth) acrylic resin immersed in tetrahydrofuran and then dried, ) It can obtain | require by measuring ratio with the weight of acrylic resin.

Since the said support plate side adhesive layer has the said gel fraction, it has moderate hardness with the adhesive force required in order to use it as an adhesive tape. Further, the (meth) acrylic resin contained in the support plate-side pressure-sensitive adhesive layer has the acid value and the hydroxyl value, thereby suppressing an increase in adhesive force due to heating. Therefore, the support plate-side pressure-sensitive adhesive layer has an appropriate hardness without increasing the adhesive force more than necessary even after heating. It becomes possible to discharge to the adhesive interface with high efficiency.

Of the pressure-sensitive adhesive layer of the double-sided pressure-sensitive adhesive tape of the present invention, the pressure-sensitive adhesive layer to be bonded to the wafer (hereinafter also referred to as “wafer-side pressure-sensitive adhesive layer”) is not particularly limited, and a conventionally known one can be used. In particular, when an adhesive that cures by stimulation is used, it is flexible and excellent in following the irregularities of the circuit formed on the surface of the wafer before being stimulated, but cured by applying light or other stimuli. Then, after the adhesive force is reduced and the support plate is peeled off, it can be easily peeled off from the wafer.

Examples of the pressure-sensitive adhesive that is cured by stimulation used for the wafer-side pressure-sensitive adhesive layer include a photo-curing adhesive.
A conventionally well-known thing can be used for the said photocurable adhesive. Specifically, for example, a (meth) acrylic acid alkyl ester-based polymerizable polymer having a radical polymerizable unsaturated bond in the molecule and a radical polymerizable polyfunctional oligomer or monomer as main components are necessary. The thing using the photocurable adhesive which contains a photoinitiator according to it, etc. are mentioned.

The double-sided pressure-sensitive adhesive tape of the present invention is used to reinforce a semiconductor wafer by bonding a semiconductor wafer and a support plate when manufacturing an IC chip. At the time of peeling, gas is generated from the gas generating agent contained in the support plate-side pressure-sensitive adhesive layer by giving a stimulus, and the double-sided pressure-sensitive adhesive tape and the support plate are peeled off by the pressure of the gas. At this time, air retention occurs between the base material of the double-sided pressure-sensitive adhesive tape and the support plate-side pressure-sensitive adhesive layer, and the entire support-plate-side pressure-sensitive adhesive layer is deformed into a wavy shape, thereby ensuring re-adhesion of the support plate. Can be prevented. As described above, after peeling between the double-sided pressure-sensitive adhesive tape and the support plate, the remaining flexible double-sided pressure-sensitive adhesive tape can be peeled off from the wafer so that the wafer is hardly damaged.

The semiconductor processing tape of the second aspect of the present invention will be described in detail.
When sticking an adhesive tape on the surface of a semiconductor, the sticking process is usually performed under reduced pressure so as not to bite bubbles or the like. However, it is extremely difficult to completely prevent bubbles from being caught. In particular, when unevenness such as a circuit is formed on the non-contact surface, it is inevitable that bubbles remain in the vicinity of the unevenness. Such bubbles are not a problem in normal processes. However, under the reduced pressure heating process, the bubbles expand, and the pressure for peeling off increases. On the other hand, the pressure-sensitive adhesive generally tends to decrease in elastic modulus and tan δ as the temperature increases. The cause of peeling when a pressure-sensitive adhesive tape using a conventional photocurable pressure-sensitive adhesive is used during processing of a semiconductor having a reduced pressure heating process is due to the high temperature of the peeling pressure generated by expansion of bubbles due to reduced pressure heating. It was considered that the pressure-sensitive adhesive layer having a reduced elastic modulus and tan δ cannot relax the peeling pressure.
As a result of intensive studies, the present inventors finely dispersed silica fine particles so as to satisfy certain conditions in the pressure-sensitive adhesive layer, thereby suppressing a decrease in the elastic modulus and tan δ of the pressure-sensitive adhesive layer in a high temperature range, It has been found that the occurrence of peeling can be effectively suppressed even when used in the processing of a semiconductor having a heating step, and the present invention has been completed.

According to the conventional concept, it has been thought that the adhesive strength of the pressure-sensitive adhesive layer containing silica increases rather than the elastic modulus (E ′ or G ′) increases (hardens). Surprisingly, however, the pressure-sensitive adhesive layer containing silica fine particles so as to have a particle size (dispersion size) below a certain level significantly improves the peel strength at high temperatures, and the peel pressure generated by the expansion of bubbles. Even if applied, it does not peel easily. Although the reason for this is not clear, it is considered that the fluid component maintains the adhesive force while the sea-island structure, which is pseudo-crosslinking, maintains the configuration at high temperature.

The tape for semiconductor processing of the present invention has an adhesive layer on at least one surface of a substrate.
The semiconductor processing tape of the present invention may be a single-sided adhesive tape having an adhesive layer formed on only one side, or a double-sided adhesive tape having an adhesive layer formed on both sides.

Although it does not specifically limit as said base material, It is preferable that it is what permeate | transmits or passes light, For example, transparent, such as an acryl, an olefin, a polycarbonate, vinyl chloride, ABS, a polyethylene terephthalate (PET), nylon, urethane, a polyimide And a sheet made of a simple resin, a sheet having a network structure, a sheet having holes, and the like.

The pressure-sensitive adhesive layer contains a photocurable pressure-sensitive adhesive and silica fine particles.
It does not specifically limit as said photocurable adhesive, A conventionally well-known thing can be used. Specifically, for example, a (meth) acrylic acid alkyl ester-based polymerizable polymer having a radical polymerizable unsaturated bond in the molecule and a radical polymerizable polyfunctional oligomer or monomer as main components are necessary. The thing using the photocurable adhesive which contains a photoinitiator according to it, etc. are mentioned.
The pressure-sensitive adhesive layer made of such a photo-curable pressure-sensitive adhesive is uniformly and rapidly polymerized and integrated by light irradiation, so that the elastic modulus increases significantly due to polymerization and curing. Adhesive strength is greatly reduced.

The polymerizable polymer is prepared by, for example, previously synthesizing a (meth) acrylic polymer having a functional group in the molecule (hereinafter referred to as a functional group-containing (meth) acrylic polymer) and reacting with the functional group in the molecule. It can obtain by making it react with the compound (henceforth a functional group containing unsaturated compound) which has a functional group to perform and a radically polymerizable unsaturated bond.

The functional group-containing (meth) acrylic polymer is an acrylic having an alkyl group usually in the range of 2 to 18 as a polymer having adhesiveness at room temperature, as in the case of a general (meth) acrylic polymer. By copolymerizing an acid alkyl ester and / or methacrylic acid alkyl ester as a main monomer, a functional group-containing monomer, and, if necessary, another modifying monomer copolymerizable therewith by a conventional method It is obtained. The weight average molecular weight of the functional group-containing (meth) acrylic polymer is usually about 200,000 to 2,000,000.

Examples of the functional group-containing monomer include carboxyl group-containing monomers such as acrylic acid and methacrylic acid, hydroxyl group-containing monomers such as hydroxyethyl acrylate and hydroxyethyl methacrylate, and epoxy such as glycidyl acrylate and glycidyl methacrylate. Examples thereof include group-containing monomers, isocyanate group-containing monomers such as isocyanate ethyl acrylate and isocyanate ethyl methacrylate, and amino group-containing monomers such as aminoethyl acrylate and aminoethyl methacrylate.
Examples of other modifying monomers that can be copolymerized include various monomers used in general (meth) acrylic polymers such as vinyl acetate, acrylonitrile, and styrene.

The functional group-containing unsaturated compound to be reacted with the functional group-containing (meth) acrylic polymer is the same as the functional group-containing monomer described above according to the functional group of the functional group-containing (meth) acrylic polymer. it can. For example, when the functional group of the functional group-containing (meth) acrylic polymer is a carboxyl group, an epoxy group-containing monomer or an isocyanate group-containing monomer is used, and when the functional group is a hydroxyl group, an isocyanate group-containing monomer is used. When the functional group is an epoxy group, a carboxyl group-containing monomer or an amide group-containing monomer such as acrylamide is used, and when the functional group is an amino group, an epoxy group-containing monomer is used.

The polyfunctional oligomer or monomer preferably has a molecular weight of 10,000 or less, and more preferably has a molecular weight of 5, so that the three-dimensional network of the pressure-sensitive adhesive layer can be efficiently formed by heating or light irradiation. 000 or less and the number of radically polymerizable unsaturated bonds in the molecule is 2 to 20. Examples of such more preferable polyfunctional oligomers or monomers include trimethylolpropane triacrylate, tetramethylolmethane tetraacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol monohydroxypentaacrylate, dipentaerythritol hexaacrylate. Or the above-mentioned methacrylates etc. are mentioned. Other examples include 1,4-butylene glycol diacrylate, 1,6-hexanediol diacrylate, polyethylene glycol diacrylate, commercially available oligoester acrylate, and methacrylates similar to those described above. These polyfunctional oligomers or monomers may be used alone or in combination of two or more.

Examples of the photopolymerization initiator include those activated by irradiation with light having a wavelength of 250 to 800 nm. Examples of such a photopolymerization initiator include acetophenone derivative compounds such as methoxyacetophenone. Benzoin ether compounds such as benzoin propyl ether and benzoin isobutyl ether, ketal derivative compounds such as benzyldimethyl ketal and acetophenone diethyl ketal, phosphine oxide derivative compounds, bis (η5-cyclopentadienyl) titanocene derivative compounds , Benzophenone, Michler ketone, chlorothioxanthone, dodecylthioxanthone, dimethylthioxanthone, diethylthioxanthone, α-hydroxycyclohexyl phenyl ketone, 2-hydroxymethylphenol Examples include photo radical polymerization initiators such as nylpropane. These photoinitiators may be used independently and 2 or more types may be used together.

The silica fine particles are not particularly limited, and examples thereof include fumed silica, fused silica, and colloidal silica. Among them, fumed silica fine particles and fused silica fine particles are suitable because it is easy to control the amount of hydroxyl groups on the surface, but it is easy to control the amount of water and the primary particle size is sufficiently small. And fumed silica is more preferred.

The silica fine particles have an average particle diameter (hereinafter also referred to as “average dispersion diameter”) of 1.0 μm or less and a maximum particle diameter (hereinafter also referred to as “maximum dispersion diameter”) of 5.0 μm or less. Thus, it is dispersed in the pressure-sensitive adhesive layer. The fine effect of the present invention can be exhibited only by finely dispersing under such conditions.
The preferable lower limit of the average dispersion diameter is not particularly limited. The smaller the better, the better. However, the current technique has a limit of about 0.05 μm.
A preferable upper limit of the maximum dispersion diameter is 2.0 μm. Although the preferable minimum of the said maximum dispersion diameter is not specifically limited, About 0.5 micrometer will be a limit with the present technique.
In the present specification, the average dispersion diameter and the maximum dispersion diameter are values measured by nanotrack (UPA-UT) using a dynamic light scattering method.

In order to finely disperse the silica fine particles as described above, at least the following four are important.
First, it is to use silica fine particles having a primary particle size as small as possible as a raw material. A preferable upper limit of the primary particle diameter of the raw material silica fine particles is 50 nm. When the primary particle diameter of the silica fine particles exceeds 50 nm, it is difficult to achieve the fine dispersion state described above. A more preferable upper limit of the primary particle diameter of the silica fine particles is 30 nm. The lower limit of the primary particle size of the silica fine particles is preferably as small as possible, but the current technology has a limit of about 5 nm.

Second, surface treatment is performed so that the silica fine particles are easily dispersed. Examples of the surface treatment include chemical treatment such as methoxy group treatment, ethoxy group treatment, phenyl group treatment, glycidyl group treatment, and physical treatment such as.
By performing the surface treatment, hydroxyl groups on the surface of the silica fine particles are consumed, but all the hydroxyl groups are not consumed, so the effect of the present invention is not affected.

Thirdly, a dispersion device capable of high dispersion is used as a dispersion method. Examples of a highly dispersible dispersing device include a high-speed stirring and dispersing device such as a homodisper, a homomixer, an ultra tarax, a shear flow, and a homogenizer. When using a homodisper as the dispersing device, it is preferable to set the rotational speed of the wings to at least 2000 rpm.

Fourth, filtering the pressure-sensitive adhesive solution after dispersion. By filtering with a 500 mesh filter, particle soot exceeding 5.0 μm can be almost removed.

As a compounding quantity of the said silica particle, the minimum with respect to 100 mass parts of said photocurable adhesives is 7 mass parts, and an upper limit is 20 mass parts. If the amount of silica fine particles is less than 7 parts by mass, the effect of preventing peeling under reduced pressure heating cannot be obtained, and if it exceeds 20 parts by mass, the adhesiveness at room temperature becomes insufficient, The silica fine particles may not be uniformly kneaded into the adhesive. The minimum with the preferable compounding quantity of the said silica fine particle is 10 mass parts, and a preferable upper limit is 17 mass parts.

The pressure-sensitive adhesive layer may contain a gas generating agent that generates gas when irradiated with light. When the pressure-sensitive adhesive layer containing such a gas generating agent is irradiated with light, the photo-curing pressure-sensitive adhesive is cross-linked and cured, and the elastic modulus of the entire pressure-sensitive adhesive layer increases, and is generated in such a hard pressure-sensitive adhesive layer. Since the released gas is released from the pressure-sensitive adhesive layer to the adhesive interface and peels at least a part of the adhesive surface, the pressure-sensitive adhesive tape can be peeled off more easily.

Although it does not specifically limit as said gas generating agent, For example, an azide compound, an azo compound, etc. are mentioned. Among these, considering that the semiconductor processing tape of the present invention is used when processing a semiconductor having a reduced pressure heating step, an azide compound having excellent heat resistance is preferable.
The azide compound is not particularly limited, and can be obtained, for example, by ring-opening polymerization of 3-azidomethyl-3-methyloxetane, terephthalazide, p-tert-butylbenzazide, or 3-azidomethyl-3-methyloxetane. Examples thereof include a polymer having an azide group such as glycidyl azide polymer (GAP).

The pressure-sensitive adhesive layer may appropriately contain various polyfunctional compounds that are blended in a general pressure-sensitive adhesive such as an isocyanate compound, a melamine compound, and an epoxy compound for the purpose of adjusting the cohesive force as the pressure-sensitive adhesive. In addition, known additives such as an antistatic agent, a plasticizer, a resin, a surfactant, a wax, and a fine particle filler can be added. Furthermore, you may mix | blend a heat stabilizer and antioxidant in order to improve stability of an adhesive.

The method for producing the semiconductor processing tape of the present invention is not particularly limited, and for example, a conventionally known method such as coating the above-mentioned pressure-sensitive adhesive or the like on a substrate using a doctor knife, a spin coater or the like is used. be able to.

The tape for semiconductor processing of the present invention can be suitably used for adhering to and protecting a semiconductor during processing of the semiconductor having a reduced pressure heating process. The tape for semiconductor processing of the present invention has a high adhesive force to a semiconductor at room temperature and does not peel off without being irradiated with ultraviolet rays or the like even when heated under reduced pressure. Therefore, it can be suitably used also when processing a semiconductor having a step of heating under reduced pressure such as chemical vapor deposition, physical vapor deposition, sputtering, dry etching, plating or the like.

According to the present invention, there is provided a double-sided adhesive tape for semiconductor processing that is used to reinforce a semiconductor wafer by bonding a semiconductor wafer and a support plate at the time of manufacturing an IC chip. Moreover, the double-sided pressure-sensitive adhesive tape for semiconductor processing that can be peeled between the double-sided pressure-sensitive adhesive tape for semiconductor processing and the support plate can be provided. Moreover, according to this invention, the semiconductor processing tape for affixing on a semiconductor and protecting this at the time of the process of the semiconductor which has a pressure reduction heating process can be provided.

It is a schematic diagram explaining the peeling condition at the time of giving irritation | stimulation to the support plate and semiconductor wafer which were adhere | attached using the conventional double-sided adhesive tape. It is a schematic diagram explaining the peeling condition at the time of giving irritation | stimulation to the support plate and semiconductor wafer which were adhere | attached using the double-sided adhesive tape of this invention. It is a schematic diagram showing the example of a dot-shaped mold release process. Is a diagram showing the relationship between the number y of release treatment of ² per diameter x and 1cm of dots subjected dots.

Hereinafter, embodiments of the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples.

(Experimental example 1)
(1) Preparation of base material One surface of a 50 μm-thick transparent polyethylene terephthalate (PET) film subjected to corona treatment on both sides was subjected to easy adhesion treatment on the entire surface, and then shown as black in FIG. 3 by a gravure method. Like the dot pattern, a long-chain alkyl release agent Pyroyl 1050 was printed. As a result, 0.5, 1, ^{2, 3, 4, 5,} 6, 7, 8, and 9 / cm ² circular dots with a diameter of 0.5 mm treated with the release agent are formed on one surface. A substrate having a uniform density was obtained.

(2) Preparation of pressure-sensitive adhesive for supporting plate side pressure-sensitive adhesive layer The following compounds were dissolved in ethyl acetate and polymerized by irradiating with ultraviolet rays to obtain an acrylic copolymer having a weight average molecular weight of 600,000.
-2-ethylhexyl acrylate 97.5 parts by mass-2-hydroxyethyl acrylate 1.5 parts by mass-Acrylic acid 1.0 part by mass-Photopolymerization initiator 0.2 part by mass Furthermore, the acrylic copolymer after the reaction Benzophenone 0.5 parts by mass, polyisocyanate 2 parts by mass, glycidyl azide polymer (GAP5003, manufactured by NOF Corporation), 2,4-diethyl per 100 parts by mass of the resin solid content of the ethyl acetate solution containing 5 parts by mass of thioxanthone was mixed to prepare an ethyl acetate solution of the pressure-sensitive adhesive for the support plate-side pressure-sensitive adhesive layer containing the azide compound.
The acrylic resin used had an acid value of 10 mgKOH / g and a hydroxyl value of 10 mgKOH / g. In addition, the azide compound used was heated from 35 ° C. to 150 ° C. at a rate of temperature increase of 10 ° C./min by TG-DTA measurement, and the weight loss when held at 150 ° C. for 1 hour was 2%. . Furthermore, the gel fraction of the obtained pressure-sensitive adhesive for support plate side pressure-sensitive adhesive layer was 85%.

(3) Preparation of pressure-sensitive adhesive for wafer-side pressure-sensitive adhesive layer The following compounds are dissolved in ethyl acetate, polymerized by irradiating with ultraviolet rays, and a photocurable pressure-sensitive adhesive made of an acrylic copolymer having a weight average molecular weight of 700,000. An ethyl acetate solution was obtained.
-83 parts by weight of 2-ethylhexyl acrylate-10 parts by weight of butyl acrylate-2 parts by weight of acrylic acid-5 parts by weight of 2-hydroxyethyl acrylate-0.2 parts by weight of photopolymerization initiator (Irgacure 651, 50% ethyl acetate solution)
-0.01 parts by mass of lauryl mercaptan To 100 parts by mass of resin solid content of the obtained photocurable adhesive ethyl acetate solution, 3.5 parts by mass of 2-isocyanatoethyl methacrylate was added and reacted, 5 parts by mass of a photopolymerization initiator (Irgacure 651) and 1.0 part by mass of polyisocyanate are mixed with 100 parts by mass of the resin solid content of the ethyl acetate solution after the reaction, and the acetic acid of the adhesive 1 for the wafer side adhesive layer is mixed. An ethyl solution was prepared.
In addition, the shear modulus at 23 ° C. of the obtained adhesive for wafer-side adhesive layer was 1 × 10 ⁵ Pa, and tan δ was 0.41.

(4) Preparation of double-sided pressure-sensitive adhesive tape An ethyl acetate solution of the pressure-sensitive adhesive for the support plate-side pressure-sensitive adhesive layer is formed on the surface of the obtained base material on which the release agent treatment has been performed, and the dry film thickness is about 30 μm. The coating solution was dried with a doctor knife and heated at 110 ° C. for 5 minutes to evaporate the solvent and dry the coating solution. The pressure-sensitive adhesive layer after drying showed adhesiveness in a dry state. A PET film that had been subjected to a release treatment was laminated on the surface of the support-side pressure-sensitive adhesive layer after drying.
Next, an ethyl acetate solution of the pressure-sensitive adhesive for the wafer-side pressure-sensitive adhesive layer was applied on a PET film having a release treatment on the surface with a doctor knife so that the dry film thickness was about 40 μm. The coating solution was dried by heating at 5 ° C. for 5 minutes to evaporate the solvent. The wafer-side pressure-sensitive adhesive layer after drying showed adhesiveness in a dry state.
Next, the surface of the base material provided with the support plate-side pressure-sensitive adhesive layer is subjected to corona treatment without the support plate-side pressure-sensitive adhesive layer, and the wafer side of the PET film subjected to the release treatment provided with the wafer-side pressure-sensitive adhesive layer. The surface of the adhesive layer was bonded together. Thereafter, the film was allowed to stand at 40 ° C. for 3 days for curing. Thereby, the adhesive layer was provided on both surfaces, and the double-sided adhesive tape by which the surface was protected by the PET film by which the mold release process was performed was obtained.

(Experimental Examples 2-8)
A double-sided pressure-sensitive adhesive tape was obtained in the same manner as in Experimental Example 1 except that the release agent treatment applied to one surface of the substrate was changed to the dot diameters and densities shown in Tables 1 and 2.

(Comparative Example 1)
A double-sided pressure-sensitive adhesive tape was obtained in the same manner as in Experimental Example 1 except that a base material that was not subjected to the release agent treatment was used.

(Comparative Example 2)
A double-sided pressure-sensitive adhesive tape was obtained in the same manner as in Experimental Example 1 except that a base material having a release agent treatment applied to the entire surface of one side of the base material was used.

(Evaluation)
The double-sided pressure-sensitive adhesive tapes obtained in Experimental Examples 1 to 8 and Comparative Examples 1 and 2 were evaluated by the following methods.
The results are shown in Tables 1 and 2.

(Evaluation of peelability)
The PET film that protects the wafer-side pressure-sensitive adhesive layer of the double-sided pressure-sensitive adhesive tape is peeled off and attached to a silicon wafer having a diameter of 20 cm and a thickness of about 750 μm, and a circuit is formed, while PET that protects the support-plate-side pressure-sensitive adhesive layer The film was peeled off, and a glass plate having a diameter of 20.4 cm was attached to the pressure-sensitive adhesive layer using a vacuum press to produce a sample.
After placing the sample with the silicon wafer side down, using an ultra high pressure mercury lamp from the glass plate side, adjust the illuminance so that the irradiation intensity of the ultraviolet light with a wavelength of 365 nm is 40 mW / cm ² on the glass plate surface. Irradiated.
Immediately after UV irradiation (within 10 seconds) and 60 seconds after UV irradiation, when the support plate was slowly lifted upward, only the support plate was peeled off and lifted. The success rate (%) of peeling was determined.
Further, the surface of the wafer after peeling the support plate 60 seconds after UV irradiation was visually observed to evaluate the presence or absence of adhesive residue. The case where no adhesive residue was observed on the surface of the wafer was evaluated as “◯”, and the case where adhesive residue was observed was evaluated as “x”.
Furthermore, as a comprehensive evaluation, a case where the peeling success rate immediately after irradiation with ultraviolet rays is 80% or more, the peeling success rate after 60 seconds of ultraviolet irradiation is 80% or more, and the adhesive residue satisfies both “◯”. The case where any one of them was not satisfied was evaluated as “x”.

(Experimental example 9)
A double-sided pressure-sensitive adhesive tape was obtained by the same method as in Experimental Example 1 except that the silicon-based release agent KM722T was used as the release agent used for the preparation of the substrate, and the dot diameters and densities shown in Table 3 were used.
About the obtained adhesive tape, the mold release property was evaluated by the method similar to the above.
The results are shown in Table 3.

(Experimental example 10)
A double-sided pressure-sensitive adhesive tape was obtained by the same method as in Experimental Example 1 except that the fluorine-based mold release agent EGC-1720 was used as the mold release agent used for the preparation of the substrate, and the dot diameters and densities shown in Table 4 were used. .
About the obtained adhesive tape, the mold release property was evaluated by the method similar to the above.
The results are shown in Table 4.

(Experimental example 11)
On one surface of a transparent polyethylene terephthalate (PET) film having a thickness of 50 μm, corona treatment was performed in a state in which the portions corresponding to the dots were masked so as to have the dot diameters and densities shown in Table 5. A double-sided pressure-sensitive adhesive tape was obtained in the same manner as in Experimental Example 1 except that the obtained base material was used.
About the obtained adhesive tape, the mold release property was evaluated by the method similar to the above.
The results are shown in Table 5.

Example 1
(1) Preparation of photocurable pressure-sensitive adhesive The following compounds are dissolved in ethyl acetate, polymerized by irradiation with ultraviolet rays, and an ethyl acetate solution of a photocurable pressure-sensitive adhesive made of an acrylic copolymer having a weight average molecular weight of 700,000. Got.
Butyl acrylate 79 parts by mass Ethyl acrylate 15 parts by mass Acrylic acid 1 part by mass 2-hydroxyethyl acrylate 5 parts by mass Photopolymerization initiator 0.2 part by mass (Irgacure 651, 50% ethyl acetate solution)
Lauryl mercaptan 0.01 parts by weight

(2) Preparation of composition solution for pressure-sensitive adhesive layer To 100 parts by mass of resin solid content of the resulting photocurable pressure-sensitive adhesive ethyl acetate solution, 3.5 parts by mass of 2-isocyanatoethyl methacrylate was added and reacted. Furthermore, 7 mass of fumed silica (manufactured by Tokuyama, MT-10, primary particle size is 15 nm) whose surface is subjected to methoxy group treatment with respect to 100 mass parts of resin solid content of the ethyl acetate solution after the reaction Part, 5 parts by mass of a photopolymerization initiator (Irgacure 651) and 0.5 parts by mass of polyisocyanate were added, and the mixture was stirred for 10 minutes at a rotational speed of 3000 rpm using a homodisper (manufactured by PRIMIX, TK homodisper). Then, it filtered using the 500 mesh nylon filter, and obtained the composition solution for adhesive layers.

(3) Manufacture of semiconductor processing tape The thickness of the dried film on the corona treatment of a 75 μm-thick transparent polyethylene terephthalate (PET) film obtained by subjecting the obtained adhesive layer composition solution to corona treatment on one side Was applied with a doctor knife so as to be about 15 μm, and heated at 110 ° C. for 5 minutes to dry the coating solution. The pressure-sensitive adhesive layer after drying showed adhesiveness in a dry state. Next, a PET film that was subjected to a release treatment was attached to the surface of the pressure-sensitive adhesive layer. Thereafter, static curing was performed at 40 ° C. for 3 days to obtain a semiconductor processing tape.

(Example 2)
A composition solution for the pressure-sensitive adhesive layer was prepared in the same manner as in Example 1 except that the amount of fumed silica was changed to 10 parts by mass to obtain a tape for semiconductor processing.

(Example 3)
A composition solution for the pressure-sensitive adhesive layer was prepared in the same manner as in Example 1 except that the amount of fumed silica was 20 parts by mass and the rotational speed of the homodisper was 4000 rpm, to obtain a semiconductor processing tape.

Example 4
Adhesive layer as in Example 1 except that 10 parts by mass of Quatron PL-7 (primary particle size: 50 nm) manufactured by Fuso Chemical Industry Co., Ltd. was used as the fumed silica, and the rotational speed of the homodisper was 4000 rpm. A composition solution was prepared to obtain a semiconductor processing tape.

(Comparative Example 3)
A composition solution for the pressure-sensitive adhesive layer was prepared in the same manner as in Example 2 except that spherical silica (SO-E1, manufactured by Admatechs, primary particle size was 200 nm (large)), and a semiconductor processing tape was prepared. Obtained.

(Comparative Example 4)
A composition solution for the pressure-sensitive adhesive layer was prepared in the same manner as in Example 2 except that fumed silica that had not been surface-treated (Tokuyama, QS-10, primary particle size: 15 nm) was used. . However, since the fumed silica could not be sufficiently dispersed, the sample could not be prepared without filtration.

(Comparative Example 5)
A composition solution for the pressure-sensitive adhesive layer was prepared in the same manner as in Example 2 except that a normal low-speed rotating stirrer (BL600, manufactured by Haydon, rpm 1000 or less) was used instead of the homodisper as the dispersing device, and the semiconductor processing Tape was obtained.

(Comparative Example 6)
Except not having performed filtration, it carried out similarly to Example 2, and prepared the composition solution for adhesive layers, and obtained the tape for semiconductor processing.

(Comparative Example 7)
A composition solution for the pressure-sensitive adhesive layer was prepared in the same manner as in Example 1 except that the amount of fumed silica was changed to 5 parts by mass to obtain a tape for semiconductor processing.

(Comparative Example 8)
An adhesive layer composition solution was prepared in the same manner as in Example 3 except that the amount of fumed silica was 30 parts by mass. However, since the fumed silica could not be sufficiently dispersed, the sample could not be prepared without filtration.

(Evaluation)
The tapes for semiconductor processing obtained in Examples 1 to 4 and Comparative Examples 3 to 8 were evaluated by the following methods.
The results are shown in Tables 6 and 7.

(1) Evaluation of dispersion state of silica fine particles The average dispersion diameter and maximum dispersion diameter of fumed silica in the pressure-sensitive adhesive layer were determined by a dynamic light scattering method (UPA-UT).

(2) Evaluation of peel strength After laminating an adhesive tape with a width of 2.5 cm on a silicon wafer, peeling was performed at 25 ° C, 80 ° C and 120 ° C using a tensile tester equipped with a hot plate that can be heated at a constant temperature. The strength was determined.

(Evaluation of heat resistance under reduced pressure)
The obtained semiconductor processing tape was used as a back surface grinding tape, and was affixed on a silicon wafer having a thickness of 200 μm on which a circuit had been formed, at room temperature and reduced pressure. Subsequently, it left still in a pressure reduction bonding machine, and it heat-processed under reduced pressure for 20 minutes on 100 Pa and 130 degreeC conditions.
The test was carried out 10 times for each semiconductor processing tape, and the number where peeling did not occur during processing was determined.

According to the present invention, there is provided a double-sided adhesive tape for semiconductor processing that is used to reinforce a semiconductor wafer by bonding a semiconductor wafer and a support plate at the time of manufacturing an IC chip. Moreover, the double-sided pressure-sensitive adhesive tape for semiconductor processing that can be peeled between the double-sided pressure-sensitive adhesive tape for semiconductor processing and the support plate can be provided. ADVANTAGE OF THE INVENTION According to this invention, the semiconductor processing tape for sticking to a semiconductor and protecting this at the time of the process of the semiconductor which has a pressure reduction heating process can be provided.

DESCRIPTION OF SYMBOLS 1 Semiconductor wafer 2 Support plate 3 Double-sided adhesive tape 31 Base material 32 Adhesive layer on the side which adheres to a support plate 33 Adhesive layer on the side which adheres to a wafer 4 Double-sided adhesive tape 41 Base material 411 Release processing part 42 Support plate and Adhesive layer 43 on the side to be bonded Adhesive layer 5 on the side to be bonded to the wafer 5 Air reservoir

Claims (3)

A semiconductor processing tape for protecting a semiconductor by attaching it to a semiconductor at the time of processing the semiconductor having a reduced pressure heating process,
It has a pressure-sensitive adhesive layer containing 7 to 20 parts by mass of silica fine particles with respect to 100 parts by mass of the photocurable pressure-sensitive adhesive on at least one surface of the substrate,
The tape for semiconductor processing, wherein the silica fine particles are dispersed in the pressure-sensitive adhesive layer so that the average particle size is 0.9 μm or less and the maximum particle size is 5.0 μm or less. 2. The semiconductor processing tape according to claim 1, wherein the silica fine particles are fumed silica fine particles. The semiconductor processing tape according to claim 1, wherein the pressure-sensitive adhesive layer contains a gas generating agent.

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