JP7723601B2 - Silicone-based graft copolymer, pressure-sensitive adhesive composition, pressure-sensitive adhesive tape, and method for manufacturing semiconductor device - Google Patents

Description

The present invention relates to a silicone-based graft copolymer, an adhesive composition and adhesive tape containing the silicone-based graft copolymer, and a method for manufacturing a semiconductor device.

In recent years, adhesive tapes have been used in a variety of industrial fields. In the construction industry, double-sided adhesive tapes are used for temporary fixing of protective sheets and bonding of interior materials. In the automotive industry, double-sided adhesive tapes are used for fixing interior components such as seats and sensors, and for fixing exterior components such as side moldings and side visors. In the electrical and electronics industry, double-sided adhesive tapes are used for module assembly and bonding of modules to housings. Specifically, double-sided adhesive tapes are used for assembly in portable electronic devices (e.g., mobile phones, personal digital assistants, etc.) equipped with image display devices or input devices. More specifically, double-sided adhesive tapes are used to bond cover panels for protecting the surfaces of portable electronic devices to touch panel modules or display panel modules, or to bond touch panel modules to display panel modules. Such double-sided adhesive tapes are punched into shapes such as picture frames and placed around the display screen (e.g., Patent Documents 1 and 2). Double-sided adhesive tapes are also used to fix vehicle components (e.g., in-vehicle panels) to the vehicle body.

JP 2009-242541 A JP 2009-258274 A

Depending on the application of the adhesive tape, it may be necessary to perform a high-temperature heat treatment process while the adhesive tape is attached to the adherend, after which the adhesive tape must be peeled off. For example, in the semiconductor chip manufacturing process, various high-temperature heat treatment processes are performed on a semiconductor wafer that is reinforced by being adhered to a support plate via double-sided adhesive tape, after which the semiconductor wafer is peeled off from the support plate. If the adhesive tape's adhesion is increased by the high-temperature heat treatment process, it may become difficult to peel the semiconductor wafer from the support plate, or adhesive may remain on the surface of the semiconductor wafer during peeling. To address this issue, a silicone compound is blended into the adhesive layer as a peeling aid. By blending a silicone compound, the silicone compound bleeds out of the adhesive layer, preventing increased adhesion.

However, depending on the type of adherend, conventional silicone compounds may be difficult to sufficiently suppress adhesion enhancement.Conventional silicone compounds have low polarity, so they have the property of low affinity with highly polar substances.When the adherend is highly polar, such as a semiconductor wafer, the silicone compound that bleeds out on the surface of the adhesive tape cannot remain on the surface and diffuses from the interface with the adherend.As a result, the silicone compound present at the interface between the adhesive tape and the adherend decreases, and adhesion enhancement may not be sufficiently suppressed.In particular, when a heat treatment process of 200 ° C or more is involved, the silicone compound becomes more mobile due to heat, so the silicone compound is easily separated from the interface with the adherend, resulting in increased adhesion enhancement.
Furthermore, silicone compounds that bleed out onto the surface of the adhesive tape may contaminate the adherend, and if the adherend, such as a semiconductor wafer, is contaminated after the adhesive tape has been peeled off, problems may arise when the adherend is subjected to a subsequent manufacturing process.
Therefore, it is required that the silicone compound that bleeds out onto the surface of the adhesive tape remains at the interface with the adherend, sufficiently suppressing adhesion enhancement, while not contaminating the adherend.

In addition, while adhesive tapes need to suppress increased adhesion, they also need to have high adhesive strength when applied (hereinafter, the adhesive strength when applied is referred to as initial adhesive strength) and not peel off even during high-temperature heat treatment processes. However, for the reasons mentioned above, conventional silicone compounds cannot suppress increased adhesion unless they are used in large quantities, and there is also the problem that using large amounts of silicone compounds reduces initial adhesive strength and causes the adhesive tape to peel off when subjected to high-temperature heat treatment processes.

In view of the above-mentioned current situation, the present invention aims to provide a silicone-based graft copolymer that can form a pressure-sensitive adhesive layer that is resistant to peeling even when subjected to a high-temperature heat treatment process, and that can enhance adhesion and suppress contamination of the adherend. The present invention also aims to provide a pressure-sensitive adhesive composition and pressure-sensitive adhesive tape that contain the silicone-based graft copolymer, as well as a method for manufacturing a semiconductor device.

The present invention provides a silicone graft copolymer having a structure derived from a polar functional group-containing monomer and a structure derived from a silicone macromonomer, which has a glass transition temperature of 30°C or lower as measured using differential scanning calorimetry, and a 5% weight loss temperature of 300°C or higher as measured using a simultaneous thermogravimetry and differential thermal analyzer at a heating rate of 10°C/min.
The present invention will be described in detail below.

The silicone graft copolymer of the present invention has a structure derived from a polar functional group-containing monomer and a structure derived from a silicone macromonomer, and preferably further has a structure derived from a monomer containing a functional group crosslinkable with the polar functional group.
When the silicone graft copolymer of the present invention has polar functional groups, when used in a pressure-sensitive adhesive tape, it is likely to gather at the interface with a highly polar adherend, thereby suppressing increased adhesion at high temperatures and further increasing the initial adhesive strength. The silicone graft copolymer that gathers at the interface with the adherend can be crosslinked via the polar functional groups with the pressure-sensitive adhesive component directly or, if necessary, via a crosslinking agent, and fixed at the interface with the adherend. This means that the silicone moiety is also fixed at the interface with the adherend, suppressing increased adhesion at high temperatures and also suppressing contamination of the adherend.
Furthermore, if the silicone graft copolymer of the present invention has a functional group capable of crosslinking with a polar functional group, it can bond with the polar functional group of another silicone graft copolymer. By bonding between silicone graft copolymers (self-crosslinking), the elastic modulus of the pressure-sensitive adhesive layer increases, making it possible to further suppress increased adhesion at high temperatures and also to suppress adhesive residue.

The polar functional group-containing monomer is not particularly limited as long as it contains a polar functional group. Examples of polar functional groups include hydroxyl groups, carboxyl groups, amide groups, and epoxy groups. Examples of hydroxyl group-containing monomers include 4-hydroxybutyl (meth)acrylate, hydroxypropyl (meth)acrylate, and 2-hydroxyethyl (meth)acrylate. Examples of carboxyl group-containing monomers include (meth)acrylic acid, 2-(meth)acryloyloxyethyl succinate, 2-(meth)acryloyloxyethyl phthalate, 2-(meth)acryloyloxyethyl hexahydrophthalate, and β-carboxyethyl (meth)acrylate. Examples of amide group-containing monomers include acrylamide, hydroxyethyl acrylamide, isopropyl acrylamide, and dimethylaminopropyl acrylamide. Examples of epoxy group-containing monomers include glycidyl (meth)acrylate. Among these, hydroxyl group-containing monomers are preferred because they tend to accumulate at the interface with highly polar adherends. When a crosslinking agent is used, a carboxyl group-containing monomer is preferred because crosslinking with the pressure-sensitive adhesive component is easily formed via the crosslinking agent. Furthermore, a hydroxyl group-containing (meth)acrylate monomer or a carboxyl group-containing (meth)acrylate monomer is more preferred because of excellent heat resistance and weather resistance, and a hydroxyl group-containing (meth)acrylate monomer is even more preferred.

The content of the structure derived from the polar functional group-containing monomer in the silicone graft copolymer of the present invention is preferably 0.1% by weight or more and 30% by weight or less.
By having the content of the structure derived from the polar functional group-containing monomer within the above range, adhesion can be enhanced and contamination of the adherend can be further suppressed at high temperatures. From the viewpoint of further enhancing adhesion and suppressing contamination of the adherend at high temperatures, the lower limit of the content of the structure derived from the polar functional group-containing monomer is more preferably 0.3 wt%, even more preferably 0.5 wt%, even more preferably 0.7 wt%, and particularly preferably 1 wt%. The upper limit of the content of the structure derived from the polar functional group-containing monomer is more preferably 20 wt%, even more preferably 18 wt%, even more preferably 15 wt%, even more preferably 12 wt%, even more preferably 10 wt%, even more preferably 8 wt%, and particularly preferably 5 wt%.

The monomer containing a functional group crosslinkable with the polar functional group is not particularly limited as long as it contains a functional group crosslinkable with the polar functional group. Examples of functional groups crosslinkable with the polar functional group include an isocyanate group when the polar functional group is a hydroxyl group, and an epoxy group when the polar functional group is a carboxyl group. Examples of isocyanate group-containing monomers include 2-isocyanatoethyl (meth)acrylate. Examples of epoxy group-containing monomers include glycidyl (meth)acrylate. Among these, isocyanate group-containing monomers are preferred because they can crosslink with hydroxyl group-containing monomers that tend to accumulate at the interface with highly polar substrates. Blocked isocyanate group-containing monomers in which a protecting group, as described below, is bonded to the isocyanate group are even more preferred. Blocked isocyanate group-containing (meth)acrylic monomers are even more preferred because of their excellent heat resistance and weather resistance.

The monomer containing a functional group capable of crosslinking with the polar functional group preferably has a protecting group bonded to the functional group capable of crosslinking with the polar functional group.
The monomer containing the functional group crosslinkable with the polar functional group has a protecting group bonded to the functional group crosslinkable with the polar functional group, thereby preventing unintended self-crosslinking reactions. Conventionally known protecting groups can be used as appropriate for the protecting group depending on the functional group crosslinkable with the polar functional group. For example, when the functional group crosslinkable with the polar functional group is a carboxy group, examples of the protecting group include a vinyl ether group, and when the functional group crosslinkable with the polar functional group is an isocyanate group, examples of the protecting group include a pyrazole group. Among these, a protecting group that is cleaved by heat is preferred because it can initiate a self-crosslinking reaction during a heat treatment step. Examples of protecting groups that are cleaved by heat include a pyrazole group, a phenol group, an oxime group, a lactam group, and a vinyl ether group.

In the silicone graft copolymer of the present invention, the content of the structure derived from the monomer containing a functional group capable of crosslinking with the polar functional group is preferably 0.1% by weight or more and 20% by weight or less.
By setting the content of the structure derived from the monomer containing a functional group crosslinkable with a polar functional group within the above range, adhesion can be enhanced and contamination of the adherend can be further suppressed at high temperatures. From the viewpoint of further enhancing adhesion and suppressing contamination of the adherend at high temperatures, the lower limit of the content of the structure derived from the monomer containing a functional group crosslinkable with a polar functional group is more preferably 0.3 wt%, even more preferably 0.5 wt%, even more preferably 0.7 wt%, and particularly preferably 1 wt%. The upper limit of the content of the structure derived from the monomer containing a functional group crosslinkable with a polar functional group is more preferably 10 wt%, even more preferably 8 wt%, and even more preferably 5 wt%.

The silicone macromonomer may be any monomer having a siloxane bond, such as an acrylic monomer having a siloxane bond or a styrene monomer having a siloxane bond. Among these, acrylic monomers having a siloxane bond are preferred due to their excellent heat resistance and weather resistance. Examples of the acrylic monomers having a siloxane bond include monomers having a structure represented by the following general formula (1) or (2):

Here, R represents a (meth)acryloyl group-containing functional group, and X and Y each independently represent an integer of 0 or more, typically an integer of 5,000 or less, particularly 500 or less.

The content of the structure derived from the silicone macromonomer in the silicone graft copolymer of the present invention is preferably 1% by weight or more and 90% by weight or less.
By ensuring that the content of the structure derived from the silicone macromonomer is within the above range, it is possible to further suppress the increase in adhesion at high temperatures. From the viewpoint of further suppressing the increase in adhesion at high temperatures, the lower limit of the content of the structure derived from the silicone macromonomer is more preferably 5 wt %, even more preferably 10 wt %, and even more preferably 80 wt %, and even more preferably 60 wt %.

When the polar functional group-containing monomer is a hydroxyl group-containing monomer and the monomer containing a functional group crosslinkable with the polar functional group is an isocyanate group-containing monomer, it is preferable that the equivalent ratio of the hydroxyl group to the isocyanate group (hydroxyl group/isocyanate group) is 0.1 or more and 10 or less.
By setting the ratio of hydroxyl groups to isocyanate groups within the above range, the self-crosslinking reaction proceeds efficiently, thereby further improving the elastic modulus of the pressure-sensitive adhesive layer at the interface with the adherend and reducing adhesive residue on the adherend. From the viewpoint of further reducing adhesive residue on the adherend, the equivalent ratio of the hydroxyl groups to the isocyanate groups is more preferably 0.2 or more, even more preferably 0.4 or more, more preferably 4 or less, and even more preferably 2.5 or less.

The silicone graft copolymer of the present invention may have a structure derived from a monomer other than the polar functional group-containing monomer, the monomer containing a functional group crosslinkable with the polar functional group, and the silicone macromonomer.
Examples of the other monomers include (meth)acrylic acid alkyl esters, such as methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, tert-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, isononyl (meth)acrylate, isomyristyl (meth)acrylate, stearyl (meth)acrylate, and isostearyl (meth)acrylate.
Examples of the other monomers include cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, benzyl (meth)acrylate, 2-butoxyethyl (meth)acrylate, 2-phenoxyethyl (meth)acrylate, glycidyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, and polypropylene glycol mono(meth)acrylate.

The silicone graft copolymer of the present invention has an upper limit of 30° C. for the glass transition temperature (Tg) measured using differential scanning calorimetry.
If the glass transition temperature is 30°C or lower, the silicone graft copolymer is less likely to adhere to the adherend, thereby preventing contamination of the adherend. The upper limit of the glass transition temperature is preferably 10°C, and more preferably -10°C. There is no particular restriction on the lower limit of the glass transition temperature, and although the lower the better, the substantial lower limit is about -80°C.
The glass transition temperature can be measured using a 5 mg sample of the silicone graft copolymer placed in an aluminum sample container (e.g., a 6.8 mm diameter aluminum autosampler sample container manufactured by Hitachi High-Tech Science Corporation) under a nitrogen atmosphere (nitrogen flow, flow rate 50 mL/min). The measurement can be performed using differential scanning calorimetry (e.g., an SII Exstar 6000/DSC 6220 manufactured by Hitachi High-Tech Science Corporation) from -100°C to 100°C at a heating rate of 10°C/min, and the resulting first-run value can be used.

While there are no particular limitations on the method for adjusting the glass transition temperature to within the above range, it is preferable to select and use a monomer that lowers the glass transition temperature of the copolymer. Among the other monomers mentioned above, examples of monomers that lower the glass transition temperature of the copolymer include n-butyl acrylate, 2-ethylhexyl acrylate, and n-octyl acrylate. Of these, 2-ethylhexyl acrylate is preferred because it has a particularly large effect in lowering the glass transition temperature of the copolymer.

The silicone graft copolymer of the present invention has a lower limit of 300°C for a 5% weight loss temperature (T _d5 ) measured at a heating rate of 10°C/min using a simultaneous thermogravimetry and differential thermal analyzer.
If the 5% weight loss temperature is 300°C or higher, the heat resistance of the silicone graft copolymer increases and it becomes less likely to decompose even at high temperatures, so that when used in an adhesive tape, the amount of outgassing is reduced even at high temperatures, making the adhesive tape less likely to peel. The preferred lower limit of the 5% weight loss temperature is 305°C, more preferably 320°C, and even more preferably 350°C. There are no particular limitations on the upper limit of the 5% weight loss temperature, and a higher temperature is preferable, but the practical upper limit is about 400°C.
The 5% weight loss temperature can be measured by the following method.
A 10 mg sample of silicone graft copolymer is placed in a platinum sample container (e.g., a Pt open-type sample container, φ5.2, H2.5 mm, manufactured by Hitachi High-Tech Science Corporation) and measured under a nitrogen atmosphere (nitrogen flow, flow rate 50 mL/min). For the measurement, a simultaneous differential thermal thermogravimetry analyzer (e.g., a TG-DTA; STA7200 manufactured by Hitachi High-Tech Science Corporation) is used to heat the sample from 25°C at a heating rate of 10°C/min, and measure the weight loss. The weight loss rate is calculated from the obtained weight loss amount and the weight before heating, and the temperature at which the weight loss rate reaches 5% is defined as the 5% weight loss temperature.

There are no particular limitations on the method for adjusting the 5% weight loss temperature to fall within the above range, but it is preferable to select and use a monomer with high heat resistance and reduce the amount of low-molecular-weight components described below. Among the other monomers mentioned above, acrylates are preferred over methacrylates as highly heat-resistant monomers, and examples include n-butyl acrylate, 2-ethylhexyl acrylate, and n-octyl acrylate. Of these, 2-ethylhexyl acrylate is preferred because its ester bond is relatively stable.

The silicone graft copolymer of the present invention preferably has a silicon element content of 1% by weight or more and 30% by weight or less.
When the silicon content is 1 wt% or more, adhesion enhancement can be further suppressed, and when the silicon content is 30 wt% or less, the initial adhesive strength can be further increased and the adhesive tape becomes less likely to peel even at high temperatures. From the viewpoint of further suppressing adhesion enhancement and further improving the initial adhesive strength, the silicon content is more preferably 3 wt% or more, even more preferably 5 wt% or more, more preferably 25 wt% or less, and even more preferably 20 wt% or less.

The silicon element content can be measured by the following method.
One gram of a silicone graft copolymer sample is weighed into a platinum crucible, sulfuric acid is added, and the mixture is heated to 450°C on a hot plate to ash. The ash is melted using a mixed melting agent of sodium carbonate and boric acid, and water is added and heated to dissolve the ash. After that, a hydrochloric acid solution is added to adjust the pH. The silicon content of this solution is measured using an ICP emission spectrometer (e.g., OPTIMA 8300, manufactured by PerkinElmer Japan) to determine the silicon content of the silicone graft copolymer.

The silicone graft copolymer of the present invention preferably has a weight-average molecular weight of 400,000 or less. When the molecular weight of the silicone graft copolymer is within the above range, the mobility of the silicone graft copolymer is improved, allowing it to concentrate at the interface with the adherend, thereby further suppressing increased adhesion. From the viewpoint of further suppressing increased adhesion, the weight-average molecular weight is more preferably 200,000 or less, and even more preferably 100,000 or less. The lower limit of the weight-average molecular weight is not particularly limited, but is preferably 5,000 or more, as this facilitates crosslinking with the pressure-sensitive adhesive component and suppresses contamination of the adherend.
The weight-average molecular weight can be determined, for example, by GPC using a polystyrene standard. Specifically, the measurement can be performed using, for example, a Waters "2690 Separations Module" as a measuring instrument, a Showa Denko "GPC KF-806L" column, tetrahydrofuran as a mobile phase, a sample flow rate of 1 mL/min, and a column temperature of 40°C.

The silicone graft copolymer of the present invention is not particularly limited in the content of components having a weight-average molecular weight of 3000 or less as measured by gel permeation chromatography (hereinafter also referred to as "low molecular weight components"), but a preferred upper limit of the total amount of the silicone graft copolymer is 10 wt%. If the content of the low molecular weight components is 10 wt% or less, the amount of outgassing derived from the silicone graft copolymer is further reduced, and when used in an adhesive tape, the adhesive tape becomes less likely to peel even at high temperatures. A more preferred upper limit of the content of the low molecular weight components is 5 wt%, an even more preferred upper limit is 3 wt%, and an even more preferred upper limit is 1 wt%. The lower limit of the content of the low molecular weight components is not particularly limited, and the closer to 0 wt%, the more difficult the adhesive tape becomes to peel even at high temperatures, which is preferable.
There are no particular limitations on the method for adjusting the content of the low-molecular-weight component within the above range, and any method can be used by adjusting the type, composition, physical properties, polymerization method, etc. of the silicone graft copolymer. Among these, it is preferable to produce the silicone graft copolymer by solution polymerization (boiling point polymerization or constant temperature polymerization).

The content of low molecular weight components can be measured by the following method.
The tetrahydrofuran solution of the silicone graft copolymer is filtered through a filter (material: polytetrafluoroethylene, pore diameter: 0.2 μm). The resulting filtrate is supplied to a gel permeation chromatograph (e.g., Waters, 2690 Separations Model), and GPC measurement is performed under conditions of a sample flow rate of 1 mL/min and a column temperature of 40°C. The polystyrene-equivalent molecular weight of the silicone graft copolymer is measured, and the content and molecular weight of low molecular weight components are determined. For example, a GPC KF-806L (Showa Denko KK) is used as the column, tetrahydrofuran is used as the mobile phase, and a differential refractometer is used as the detector.

The silicone graft copolymer of the present invention can be produced by any method, including radical polymerization of the polar functional group-containing monomer, the silicone macromonomer, and, if necessary, other monomers, in a solvent. The radical polymerization method can be any conventionally known method, such as solution polymerization (boiling point polymerization or constant temperature polymerization), emulsion polymerization, suspension polymerization, or bulk polymerization. Of these, solution polymerization (boiling point polymerization or constant temperature polymerization) is preferred.

The silicone graft copolymer of the present invention may be used in any application, but it can be suitably used as a release aid for pressure sensitive adhesives.
Such a pressure-sensitive adhesive composition containing the silicone graft copolymer of the present invention, a pressure-sensitive adhesive component having a functional group crosslinkable with the silicone graft copolymer, and a crosslinking agent also constitutes one aspect of the present invention.

The pressure-sensitive adhesive composition of the present invention contains a silicone graft copolymer, a pressure-sensitive adhesive component having a functional group capable of crosslinking with the silicone graft copolymer, and a crosslinking agent.
The pressure-sensitive adhesive component of the pressure-sensitive adhesive composition of the present invention has a functional group capable of crosslinking with a silicone-based graft copolymer, so that when the composition is used in a pressure-sensitive adhesive tape, the silicone-based graft copolymer that has gathered at the interface with the adherend can be crosslinked with the pressure-sensitive adhesive component directly, or if necessary, via a crosslinking agent, and fixed at the interface with the adherend, thereby preventing contamination of the adherend. Furthermore, the pressure-sensitive adhesive composition of the present invention contains a crosslinking agent, which increases the cohesive strength of the pressure-sensitive adhesive layer, improving initial adhesive strength and making the composition less susceptible to peeling even at high temperatures.

The content of the silicone graft copolymer in the pressure-sensitive adhesive composition of the present invention is preferably 0.1 to 20 parts by weight per 100 parts by weight of the pressure-sensitive adhesive component.
When the content of the silicone-based graft copolymer in the pressure-sensitive adhesive composition of the present invention is 0.1 parts by weight or more, adhesion enhancement at high temperatures can be further suppressed. When the content of the silicone-based graft copolymer is 20 parts by weight or less, clouding of the pressure-sensitive adhesive composition can be suppressed, and processes using light, such as alignment, can be performed through the pressure-sensitive adhesive composition. From the viewpoint of further suppressing adhesion enhancement and clouding at high temperatures, the content of the silicone-based graft copolymer is more preferably 1 part by weight or more, even more preferably 5 parts by weight or more, more preferably 15 parts by weight or less, even more preferably 10 parts by weight or less, and even more preferably 8 parts by weight or less.

The pressure-sensitive adhesive component is not particularly limited as long as it has a functional group capable of crosslinking with the silicone-based graft copolymer, and may be either a non-curing pressure-sensitive adhesive or a curing pressure-sensitive adhesive. When the pressure-sensitive adhesive component is a curing pressure-sensitive adhesive, the pressure-sensitive adhesive composition of the present invention may further contain a polymerization initiator such as a thermal polymerization initiator or a photopolymerization initiator, or may not contain a polymerization initiator.
The non-curing type adhesive is not particularly limited, and examples thereof include rubber-based adhesives, adhesive (meth)acrylic polymers, vinyl alkyl ether-based adhesives, silicone-based adhesives, polyester-based adhesives, polyamide-based adhesives, urethane-based adhesives, styrene-diene block copolymer-based adhesives, etc. The curing type adhesive is not particularly limited, and examples thereof include curing type adhesive (meth)acrylic polymers, etc.
The structure of the pressure-sensitive adhesive component is not particularly limited, and may be a random copolymer or a block copolymer.

The pressure-sensitive adhesive component is preferably an adhesive (meth)acrylic polymer. When the pressure-sensitive adhesive component is an adhesive (meth)acrylic polymer, the heat resistance and weather resistance are improved, and the pressure-sensitive adhesive component can be used on a wide range of adherends.
The adhesive (meth)acrylic polymer is preferably a curable adhesive (meth)acrylic polymer. Examples of the curable adhesive (meth)acrylic polymer include polymerizable polymers. By using the polymerizable polymer, the adhesive layer can be cured by light (ultraviolet) irradiation, heat, or the like. The polymerizable polymer is more preferably a polymerizable polymer having a radically polymerizable unsaturated bond in the molecule.
The method for producing the polymerizable polymer having a radically polymerizable unsaturated bond in the molecule is not particularly limited, and examples thereof include a method in which a monomer having a radically polymerizable unsaturated bond is used when synthesizing the polymer. Another example includes a method in which a compound having a radically polymerizable unsaturated bond (hereinafter also referred to as an "unsaturated bond-containing compound") is reacted with a functional group present in the polymer that can crosslink with the silicone-based graft copolymer or other polar functional group.

The above-mentioned adhesive (meth)acrylic polymer is not particularly limited as long as it uses a monomer containing a functional group crosslinkable with the above-mentioned silicone-based graft copolymer as a raw material monomer and has a structural unit derived from the monomer containing a functional group crosslinkable with the above-mentioned silicone-based graft copolymer. Examples of raw material monomers that can be used other than the monomer containing a functional group crosslinkable with the above-mentioned silicone-based graft copolymer include (meth)acrylic acid alkyl esters having an alkyl group with 1 to 13 carbon atoms, (meth)acrylic acid alkyl esters having an alkyl group with 13 to 18 carbon atoms, and functional monomers.
Examples of (meth)acrylic acid alkyl esters having an alkyl group containing 1 to 13 carbon atoms include 2-ethylhexyl acrylate, butyl acrylate, methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, and isopropyl (meth)acrylate. Examples of (meth)acrylic acid alkyl esters having an alkyl group containing 13 to 18 carbon atoms include tridecyl methacrylate and stearyl (meth)acrylate. Examples of the functional monomers include hydroxyalkyl (meth)acrylate, glycerin dimethacrylate, glycidyl (meth)acrylate, 2-methacryloyloxyethyl isocyanate, (meth)acrylic acid, itaconic acid, maleic anhydride, crotonic acid, maleic acid, and fumaric acid. Of these, 2-ethylhexyl acrylate is preferred.

The functional group crosslinkable with the silicone graft copolymer is not particularly limited and can be appropriately selected depending on the functional group possessed by the silicone graft copolymer. For example, if the functional group possessed by the silicone graft copolymer is a hydroxyl group, examples of the functional group include an isocyanate group, a blocked isocyanate group, and an epoxy group. If the functional group possessed by the silicone graft copolymer is a carboxyl group, examples of the functional group crosslinkable with the silicone graft copolymer include an epoxy group, an epoxy group, and an isocyanate group. The hydroxyl or carboxyl group-containing monomer that serves as a raw material for the adhesive (meth)acrylic polymer can be the same as the polar functional group-containing monomer in the silicone graft copolymer of the present invention.

The content of structural units derived from monomers containing functional groups crosslinkable with the silicone graft copolymer in the above-mentioned adhesive (meth)acrylic polymer is not particularly limited. From the viewpoint of increasing cohesive strength and adhesive strength to an adherend, the content of structural units derived from monomers containing functional groups crosslinkable with the above-mentioned silicone graft copolymer is preferably 1% by weight or more and 20% by weight or less.

In addition, when the adhesive (meth)acrylic polymer is the curable adhesive (meth)acrylic polymer, the content of the structural unit derived from the monomer containing a functional group crosslinkable with the silicone graft copolymer means the content after reaction with the unsaturated bond-containing compound described below.
That is, when the adhesive (meth)acrylic polymer is the curable adhesive (meth)acrylic polymer, the crosslinkable functional group in the structural unit derived from the monomer containing a functional group crosslinkable with the silicone graft copolymer may be partially consumed when reacting with the unsaturated bond-containing compound. The crosslinkable functional group reacts with the unsaturated bond-containing compound to introduce a radically polymerizable unsaturated bond, thereby obtaining a curable adhesive (meth)acrylic polymer. However, since the crosslinkable functional group remains partially unconsumed, the obtained curable adhesive (meth)acrylic polymer can have a structural unit derived from the monomer containing a functional group crosslinkable with the silicone graft copolymer.
The content of constituent units derived from monomers containing functional groups crosslinkable with the silicone-based graft copolymer before reaction with the unsaturated bond-containing compound is not particularly limited, and is preferably 5% by weight or more and 40% by weight or less from the viewpoints of improving adhesion to adherends, crosslinking with the silicone-based graft copolymer, and reaction with the unsaturated bond-containing compound.

The unsaturated bond-containing compound is not particularly limited and can be appropriately selected depending on the functional group present in the polymer that is crosslinkable with the silicone graft copolymer or other polar functional groups.
When the functional group or other polar functional group present in the polymer that can be crosslinked with the silicone-based graft copolymer is a carboxy group, a compound having an epoxy group and a radically polymerizable unsaturated bond, or a compound having an isocyanate group and a radically polymerizable unsaturated bond is used. When the functional group or other polar functional group present in the polymer that can be crosslinked with the silicone-based graft copolymer is a hydroxyl group, a compound having an isocyanate group and a radically polymerizable unsaturated bond is used. When the functional group or other polar functional group present in the polymer that can be crosslinked with the silicone-based graft copolymer is an epoxy group, a compound having a carboxy group and a radically polymerizable unsaturated bond, or a compound having an amide group and a radically polymerizable unsaturated bond is used. When the functional group or other polar functional group present in the polymer that can be crosslinked with the silicone-based graft copolymer is an amino group, a compound having an epoxy group and a radically polymerizable unsaturated bond is used.
Among these, from the viewpoint of reactivity, it is preferred that the functional group present in the polymer that is crosslinkable with the silicone graft copolymer or the other polar functional group is a carboxyl group or a hydroxyl group, and that the unsaturated bond-containing compound is a compound having an isocyanate group and a radically polymerizable unsaturated bond.

The compound having the above-mentioned isocyanate group and radically polymerizable unsaturated bond is not particularly limited, and examples include methacryloyl isocyanate, 2-methacryloyloxyethyl isocyanate, 2-acryloyloxyethyl isocyanate, m-isopropenyl-α,α-dimethylbenzyl isocyanate, etc. By using the above-mentioned compound having an isocyanate group and a radically polymerizable unsaturated bond, it is possible to obtain a curable adhesive (meth)acrylic polymer in which a radically polymerizable unsaturated bond is introduced into the side chain of the polymer (particularly a hydroxyl group-containing polymer).

When the above-mentioned adhesive (meth)acrylic polymer is the above-mentioned curable adhesive (meth)acrylic polymer, the content of structural units having radically polymerizable unsaturated bonds in the above-mentioned curable adhesive (meth)acrylic polymer is not particularly limited, but a preferred lower limit is 1% by weight and a preferred upper limit is 20% by weight. A more preferred lower limit of the content of the above-mentioned structural units is 3% by weight, a more preferred upper limit is 18% by weight, an even more preferred lower limit is 5% by weight, and an even more preferred upper limit is 15% by weight.

The weight-average molecular weight of the adhesive (meth)acrylic polymer is not particularly limited, but is preferably from 200,000 to 2,000,000. When the weight-average molecular weight of the adhesive (meth)acrylic polymer is within the above range, the adhesive strength to the adherend can be increased.
The weight-average molecular weight can be determined, for example, by GPC using a polystyrene standard. Specifically, the measurement can be performed using, for example, a Waters "2690 Separations Module" as a measuring instrument, a Showa Denko "GPC KF-806L" column, ethyl acetate as a solvent, a sample flow rate of 1 mL/min, and a column temperature of 40°C.

The above-mentioned adhesive (meth)acrylic polymer may have a structural unit derived from another modifying monomer.
Examples of the other modifying monomers include vinyl carboxylate esters such as vinyl acetate and vinyl propionate, and acrylonitrile. Other examples include aromatic vinyl compounds such as styrene, substituted styrenes (e.g., α-methylstyrene), and vinyl toluene. Other examples include aromatic ring-containing (meth)acrylates such as aryloxyalkyl (meth)acrylates (e.g., phenyl (meth)acrylate, phenoxyethyl (meth)acrylate), and arylalkyl (meth)acrylates (e.g., benzyl (meth)acrylate). Other examples include various monomers used in general (meth)acrylic polymers, such as macromonomers having a radical polymerizable vinyl group at the end of a monomer obtained by polymerizing a vinyl group, and amide group-containing monomers. These other modifying monomers may be used alone, or two or more may be used in combination.

The adhesive (meth)acrylic polymer can be obtained by subjecting a raw material monomer mixture to a radical reaction in the presence of a polymerization initiator. As a method for subjecting the raw material monomer mixture to a radical reaction, i.e., a polymerization method, a conventionally known method can be used, such as solution polymerization (boiling point polymerization or constant temperature polymerization), emulsion polymerization, suspension polymerization, bulk polymerization, etc.
The polymerization initiator is not particularly limited, and examples thereof include organic peroxides and azo compounds. Examples of the organic peroxides include 1,1-bis(t-hexylperoxy)-3,3,5-trimethylcyclohexane, t-hexylperoxypivalate, t-butylperoxypivalate, 2,5-dimethyl-2,5-bis(2-ethylhexanoylperoxy)hexane, t-hexylperoxy-2-ethylhexanoate, t-butylperoxy-2-ethylhexanoate, t-butylperoxyisobutyrate, t-butylperoxy-3,5,5-trimethylhexanoate, and t-butylperoxylaurate. Examples of the azo compounds include azobisisobutyronitrile and azobiscyclohexanecarbonitrile. These polymerization initiators may be used alone or in combination of two or more.

The above-mentioned adhesive (meth)acrylic polymer may be obtained by living radical polymerization.
Living radical polymerization is a polymerization in which a molecular chain grows without being hindered by side reactions such as termination reactions or chain transfer reactions. Living radical polymerization can produce polymers with more uniform molecular weights and compositions than, for example, free radical polymerization, and can suppress the generation of low-molecular-weight components, etc., so that the resulting pressure-sensitive adhesive composition can be prevented from increasing adhesion at high temperatures, while also making the pressure-sensitive adhesive composition less susceptible to peeling to the extent that unintended peeling does not occur.

The living radical polymerization is not particularly limited as long as it is a commonly used method, and examples include the TERP method, the RAFT method, and the NMP method. As initiators, organic tellurium compounds are used in the TERP method, RAFT agents in the RAFT method, and nitroxide compounds in the NMP method, and these are used in combination with a radical polymerization initiator as needed.

Examples of the organotellurium compound include 2-methyl-2-n-butyltellanyl-propionic acid, (methyltellanyl-methyl)benzene, 1-chloro-4-(methyltellanyl-methyl)benzene, 1-hydroxy-4-(methyltellanyl-methyl)benzene, and 1-phenoxycarbonyl-4-(2-methyltellanyl-propyl)benzene.
Examples of RAFT agents include S-cyanomethyl-S-dodecyltrithiocarbonate, 2-cyano-2-propyl dithiobenzoate, S-(2-cyano-2-propyl)-S-dodecyltrithiocarbonate, and 2-methyl-2-[(dodecylsulfanylthiocarbonyl)sulfanyl]propanoic acid.
Examples of nitroxide compounds include di-tert-butyl-nitroxide, 4-carboxy-2,2,6,6-tetramethylpiperidine-1-oxyl, tetramethyl-isoindoline-1-oxyl, tetraethyl-isoindoline-1-oxyl, N-tert-butyl-N-[1-diethylphosphono-(2,2-dimethylpropyl)]nitroxide, and 2,2,5-trimethyl-4-phenyl-3-azahexane-3-nitroxide.

In the living radical polymerization, an azo compound may be used in addition to the initiator in order to accelerate the polymerization rate.
The azo compound is not particularly limited as long as it is one that is generally used in radical polymerization. Examples of the azo compound include 2,2'-azobis(isobutyronitrile), 2,2'-azobis(2-methylbutyronitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), 1,1-azobis(cyclohexane-1-carbonitrile), 1-[(1-cyano-1-methylethyl)azo]formamide, 4,4'-azobis(4-cyanovaleric acid), dimethyl-2,2'-azobis(2-methylpropionate), dimethyl-1,1'-azobis(1-cyclohexanecarboxylate), 2,2'-azobis{2-methyl-N-[1,1'-bis(hydroxymethyl)-2-hydroxyethyl]propionamide}, 2,2'-azobis[2-methyl-N-(2-hydroxyethyl)propionamide], 2,2 '-Azobis[N-(2-propenyl)-2-methylpropionamide], 2,2'-azobis(N-butyl-2-methylpropionamide), 2,2'-azobis(N-cyclohexyl-2-methylpropionamide), 2,2'-azobis[2-(2-imidazolin-2-yl)propane] dihydrochloride, 2,2'-azobis{2-[1-(2-hydroxyethyl)-2-imidazolin-2-yl]propane 2,2'-azobis[2-(2-imidazolin-2-yl)propane], 2,2'-azobis(2-amidinopropane) dihydrochloride, 2,2'-azobis[N-(2-carboxyethyl)-2-methylpropionamidine]tetrahydrate, 2,2'-azobis(1-imino-1-pyrrolidino-2-methylpropane) dihydrochloride, 2,2'-azobis(2,4,4-trimethylpentane), etc. These azo compounds may be used alone or in combination of two or more.

In the living radical polymerization, a dispersion stabilizer may be used. Examples of the dispersion stabilizer include polyvinylpyrrolidone, polyvinyl alcohol, methyl cellulose, ethyl cellulose, poly(meth)acrylic acid, poly(meth)acrylic acid esters, and polyethylene glycol.

As the method for the living radical polymerization, a conventionally known method can be used, and examples thereof include solution polymerization (boiling point polymerization or constant temperature polymerization), emulsion polymerization, suspension polymerization, and bulk polymerization.
When a polymerization solvent is used in the living radical polymerization, the polymerization solvent is not particularly limited. Examples of the polymerization solvent that can be used include nonpolar solvents such as hexane, cyclohexane, octane, toluene, and xylene, and highly polar solvents such as water, methanol, ethanol, propanol, butanol, acetone, methyl ethyl ketone, methyl isobutyl ketone, tetrahydrofuran, dioxane, and N,N-dimethylformamide. These polymerization solvents may be used alone or in combination of two or more. The polymerization temperature is preferably 0 to 110°C from the viewpoint of polymerization rate.

The crosslinking agent is not particularly limited, and examples include isocyanate-based crosslinking agents, epoxy-based crosslinking agents, aziridine-based crosslinking agents, metal chelate-based crosslinking agents, etc. Among these, epoxy-based crosslinking agents are preferred because they further increase the cohesive strength of the adhesive components.

The content of the crosslinking agent in the pressure-sensitive adhesive composition of the present invention is preferably 0.1% by weight or more and 20% by weight or less. By including the crosslinking agent in this range, the pressure-sensitive adhesive components can be appropriately crosslinked, further increasing the initial adhesive strength and making the pressure-sensitive adhesive tape less likely to peel even at high temperatures. From the perspective of further increasing the initial adhesive strength, a more preferred lower limit of the content of the crosslinking agent is 0.5% by weight, an even more preferred lower limit is 1% by weight, a more preferred upper limit is 15% by weight, and an even more preferred upper limit is 10% by weight.

When the pressure-sensitive adhesive component is the curable adhesive (meth)acrylic polymer, the pressure-sensitive adhesive composition of the present invention may further contain a polymerization initiator. Examples of the polymerization initiator include a photopolymerization initiator and a thermal polymerization initiator. Among these, a thermal polymerization initiator is preferred because it can cure the pressure-sensitive adhesive composition using the heat of the heat treatment step, eliminating the need for a separate step for curing the pressure-sensitive adhesive composition, and because it can cure even when used on an adherend that is opaque to light.

The photopolymerization initiator may be activated by irradiation with ultraviolet light having a wavelength of 200 to 410 nm. Examples of such photopolymerization initiators include acetophenone derivative compounds, benzoin ether compounds, ketal derivative compounds, phosphine oxide derivative compounds, bis(η5-cyclopentadienyl)titanocene derivative compounds, alkylphenone compounds, benzophenone, Michler's ketone, chlorothioxanthone, todecylthioxanthone, dimethylthioxanthone, diethylthioxanthone, α-hydroxycyclohexylphenyl ketone, and 2-hydroxymethylphenylpropane. Examples of the acetophenone derivative compounds include methoxyacetophenone. Examples of the benzoin ether compounds include benzoin propyl ether and benzoin isobutyl ether. Examples of the ketal derivative compounds include benzyl dimethyl ketal and acetophenone diethyl ketal. Commercially available alkylphenone compounds include Omnirad 184, Omnirad 651, Omnirad 369, Omnirad 2959, and Omnirad 907 (all manufactured by IGM Resins). Commercially available phosphine oxide derivative compounds include Omnirad TPO H and Omnirad 819. These photopolymerization initiators may be used alone or in combination of two or more.

The thermal polymerization initiator is not particularly limited, and examples include those that decompose when heated to generate active radicals that initiate the polymerization reaction. Specific examples include dicumyl peroxide, di-t-butyl peroxide, t-butyl peroxybenzoyl, t-butyl hydroperoxide, benzoyl peroxide, cumene hydroperoxide, diisopropylbenzene hydroperoxide, paramenthane hydroperoxide, and di-t-butyl peroxide. These thermal polymerization initiators may be used alone or in combination of two or more.

The content of the polymerization initiator is not particularly limited and is determined appropriately depending on the type of the curable adhesive (meth)acrylic polymer and the polymerization initiator, but a preferred lower limit is 0.1 parts by weight and a preferred upper limit is 10 parts by weight per 100 parts by weight of the curable adhesive (meth)acrylic polymer, a more preferred lower limit is 1 part by weight and a more preferred upper limit is 8 parts by weight.

The pressure-sensitive adhesive composition of the present invention may contain a polymerization initiator as described above, but it is more preferable that the pressure-sensitive adhesive component is the curable adhesive (meth)acrylic polymer and does not contain a polymerization initiator.
In recent years, various environmental regulations have designated some compounds of polymerization initiators as targets of regulation. Because the pressure-sensitive adhesive composition of the present invention contains the above-mentioned silicone-based graft copolymer, it is resistant to peeling even when subjected to a high-temperature heat treatment process, and can suppress enhanced adhesion and contamination of the adherend. Furthermore, because the pressure-sensitive adhesive composition of the present invention contains the above-mentioned silicone-based graft copolymer, even if it is cured only by cleavage of unsaturated double bonds and polymerization reaction in a high-temperature heat treatment process (i.e., even without containing a polymerization initiator), its adhesive strength decreases and it can be easily peeled off after the process is completed.

The adhesive composition of the present invention may, if necessary, contain known additives such as a gas generator that generates gas upon stimulation, inorganic fillers, heat stabilizers, antioxidants, antistatic agents, plasticizers, resins, waxes, etc.

The pressure-sensitive adhesive composition of the present invention preferably does not contain an emulsifier. By not containing the above-mentioned emulsifier, the heat resistance of the pressure-sensitive adhesive composition is improved, and it is less likely to decompose even at high temperatures. As a result, when used in a pressure-sensitive adhesive tape, the amount of outgassing is further reduced even at high temperatures, making the pressure-sensitive adhesive tape more difficult to peel.

In order to prevent the pressure-sensitive adhesive composition of the present invention from containing the emulsifier, it is preferable not to use the emulsifier when obtaining the silicone-based graft copolymer of the present invention and the pressure-sensitive adhesive component (adhesive polymer). To achieve this, for example, solution polymerization or the like may be employed as the polymerization method when obtaining the silicone-based graft copolymer of the present invention and the pressure-sensitive adhesive component (adhesive polymer).
The content of the emulsifier can be determined, for example, by measuring the pressure-sensitive adhesive composition using a liquid chromatography mass spectrometer (e.g., NEXCERA manufactured by Shimadzu Corporation and Exactive manufactured by Thermo Fisher Scientific). More specifically, an ethyl acetate solution of the pressure-sensitive adhesive composition is filtered through a filter (material: polytetrafluoroethylene, pore diameter: 0.2 μm). Approximately 10 μL of the obtained filtrate is injected and analyzed using the liquid chromatography mass spectrometer under the following conditions. The content of the emulsifier can be determined from the area ratio of the peak corresponding to the emulsifier to the total. It is preferable to prepare samples with known emulsifier contents in the pressure-sensitive adhesive composition for each emulsifier type, and create a calibration curve showing the relationship between the emulsifier content and the peak area ratio for analysis.
Column: Hypersil GOLD (2.1 x 150 mm) manufactured by Thermo Fisher Scientific
Mobile phase: acetonitrile Column temperature: 40°C
Flow rate: 1.0mL/min
Ionization method: ESI
Capillary temperature: 350°C
The absence of an emulsifier in the pressure-sensitive adhesive composition of the present invention means that the content of the emulsifier in the pressure-sensitive adhesive composition of the present invention, as measured using a liquid chromatography mass spectrometer, is 3 wt % or less, preferably 1 wt % or less, more preferably 0.5 wt % or less, and even more preferably 0.1 wt % or less.

The method for producing the pressure-sensitive adhesive composition of the present invention is not particularly limited, and can be obtained, for example, by adding the silicone-based graft copolymer, the crosslinking agent, and, if necessary, other additives to a solution of the pressure-sensitive adhesive components produced by the above method and mixing them.

The pressure-sensitive adhesive composition of the present invention can be used to produce a pressure-sensitive adhesive tape.
Such a pressure-sensitive adhesive tape having a substrate and a pressure-sensitive adhesive layer laminated on at least one surface of the substrate, wherein the pressure-sensitive adhesive layer contains the silicone-based graft copolymer of the present invention, also constitutes one aspect of the present invention.

The pressure-sensitive adhesive tape of the present invention has a substrate.
The material constituting the substrate is preferably a heat-resistant material. Examples of the heat-resistant material include polyethylene terephthalate, polyethylene naphthalate, polyacetal, polyamide, polycarbonate, polyphenylene ether, polybutylene terephthalate, ultra-high molecular weight polyethylene, syndiotactic polystyrene, polyarylate, polysulfone, polyethersulfone, polyphenylene sulfide, polyether ether ketone, polyimide, polyetherimide, fluororesin, and liquid crystal polymer. Among these, polyethylene naphthalate is preferred because of its excellent heat resistance.

The thickness of the substrate is not particularly limited, but the preferred lower limit is 15 μm, more preferably 25 μm, even more preferably 40 μm, and even more preferably 50 μm, and the preferred upper limit is 250 μm, more preferably 125 μm, even more preferably 100 μm, and even more preferably 75 μm. Having the substrate within this range allows for an adhesive tape with excellent handleability.

The pressure-sensitive adhesive tape of the present invention has a pressure-sensitive adhesive layer laminated on at least one surface of the substrate.
The adhesive constituting the adhesive layer can be the same as that used in the adhesive composition of the present invention.

The thickness of the adhesive layer is not particularly limited, but it is preferable that the lower limit be 3 μm and the upper limit be 100 μm. When the thickness of the adhesive layer is within the above range, it can be adhered to the support with sufficient adhesive strength. From the same perspective, a more preferable lower limit of the thickness of the adhesive layer is 5 μm, an even more preferable lower limit is 10 μm, an even more preferable lower limit is 20 μm, and a more preferable upper limit is 80 μm, an even more preferable upper limit is 60 μm, and an even more preferable upper limit is 50 μm.

The method for producing the pressure-sensitive adhesive tape of the present invention is not particularly limited, and any conventionally known method can be used. For example, the pressure-sensitive adhesive tape can be produced by applying a solution of the pressure-sensitive adhesive composition to a film that has been subjected to a release treatment, drying the film to form a pressure-sensitive adhesive layer, and then laminating the film to a substrate.

The adhesive tape of the present invention is not particularly limited in its applications, but can be suitably used in the processing of semiconductor wafers or semiconductor chips. In particular, the adhesive tape of the present invention is resistant to peeling even when subjected to high-temperature heat treatment processes, and is able to suppress increased adhesion and contamination of the adherend at high temperatures. Therefore, it is particularly suitable for use as a protective tape to protect adherends in the manufacture of products that involve high-temperature treatment processes, such as semiconductor devices. High-temperature treatment processes for semiconductor devices and the like include, for example, high-temperature treatment processes at 150°C or higher, particularly 180°C or higher, and especially 200°C or higher. The upper temperature limit for the high-temperature treatment process is not particularly limited, and is, for example, 350°C.

The adhesive tape of the present invention is resistant to peeling even when subjected to a high-temperature heat treatment process, and is capable of suppressing increased adhesion and contamination of the adherend at high temperatures. Therefore, it is particularly suitable for use as a protective tape that is attached to a ring frame and a semiconductor wafer to protect the semiconductor wafer during the processing process of the semiconductor wafer.
Figure 1 schematically shows an example of a semiconductor wafer processing step using the pressure-sensitive adhesive tape of the present invention. In the semiconductor wafer processing step shown in Figure 1, the pressure-sensitive adhesive tape 2 of the present invention is attached to a ring frame 1 and a semiconductor wafer 3 (Figure 1(a)). The semiconductor wafer 3 is then diced to obtain semiconductor chips 4 (Figure 1(b)). Note that Figure 1 illustrates a processing step for a semiconductor wafer having bumps (electrodes), but the use of the pressure-sensitive adhesive tape of the present invention is not limited to such a step. Also, Figure 1 illustrates a step for dicing a semiconductor wafer to obtain semiconductor chips, but the use of the pressure-sensitive adhesive tape of the present invention is not limited to such a step.

A method for manufacturing a semiconductor device, which includes a step of processing a semiconductor wafer or semiconductor chip using the pressure-sensitive adhesive tape of the present invention, also constitutes one aspect of the present invention.
The method for manufacturing a semiconductor device of the present invention is not particularly limited as long as it includes a step of processing a semiconductor wafer or semiconductor chip using the pressure-sensitive adhesive tape of the present invention, but it preferably includes a step of processing a semiconductor wafer as shown in Fig. 1. That is, the method for manufacturing a semiconductor device of the present invention preferably includes a step of attaching the pressure-sensitive adhesive tape of the present invention to a ring frame and a semiconductor wafer, and a step of dancing the semiconductor wafer to obtain a semiconductor chip.

The present invention provides a silicone-based graft copolymer that can form a pressure-sensitive adhesive layer that is resistant to peeling even when subjected to a high-temperature heat treatment process, and that can enhance adhesion and prevent contamination of the adherend. The present invention also provides a pressure-sensitive adhesive composition and pressure-sensitive adhesive tape that contain the silicone-based graft copolymer, as well as a method for manufacturing a semiconductor device.

1A to 1C are diagrams schematically illustrating an example of a semiconductor wafer processing step using the pressure-sensitive adhesive tape of the present invention.

The following examples further illustrate aspects of the present invention, but the present invention is not limited to these examples.

(Preparation of Acrylic Polymer)
6.38 g (50 mmol) of polymerization initiator was suspended in 50 mL of tetrahydrofuran (THF), and 34.4 mL (55 mmol) of a 1.6 mol/L n-butyllithium/hexane solution was slowly added dropwise to the suspension at room temperature. The reaction solution was stirred until the metallic tellurium completely disappeared. 10.7 g (55 mmol) of ethyl 2-bromoisobutyrate was added to the reaction solution at room temperature, and the mixture was stirred for 2 hours. After completion of the reaction, the solvent was concentrated under reduced pressure, followed by vacuum distillation to obtain ethyl 2-methyl-2-n-butyltellanylpropionate as a yellow oil.
In an argon-purged glove box, 45.7 μL of the prepared 2-methyl-2-n-butyltellanyl-ethyl propionate, 10 mg of 2,2'-azobis(2,4-dimethylvaleronitrile), and 0.5 mL of ethyl acetate were added to a reaction vessel, which was then sealed and removed from the glove box. Subsequently, while flowing argon gas into the reaction vessel, a raw material monomer mixture was added to the reaction vessel. The raw material monomer mixture consisted of 100 parts by weight of 2-ethylhexyl acrylate (2EHA), 3 parts by weight of acrylic acid (Aac), and 0.1 parts by weight of 2-hydroxyethyl acrylate (HEA). Furthermore, 68.7 g of ethyl acetate was added as a polymerization solvent, and a polymerization reaction was carried out at 60°C for 20 hours to obtain a pressure-sensitive adhesive component-containing solution. The raw materials used were as follows:
Polymerization initiator: Tellurium, metallic tellurium, 40 mesh, manufactured by Aldrich Corporation n-Butyllithium/hexane solution: manufactured by Aldrich Corporation 2,2'-Azobis(2,4-dimethylvaleronitrile): manufactured by Wako Pure Chemical Industries, Ltd.

Next, the obtained adhesive component-containing solution was diluted 50 times with tetrahydrofuran (THF), and the resulting diluted solution was filtered through a polytetrafluoroethylene filter with a pore size of 0.2 μm.Then, the obtained filtrate was fed to a gel permeation chromatograph and subjected to GPC measurement.The polystyrene-equivalent molecular weight of the adhesive component was measured to determine the weight average molecular weight (Mw) and molecular weight distribution (Mw/Mn).The results were Mw: 899,000, and Mw/Mn: 1.78.The measuring equipment and measuring conditions were as follows.
Gel permeation chromatography: e2695 Separations Module (Waters)
Detector: differential refractometer (2414, manufactured by Waters)
Column: GPC KF-806L (Showa Denko)
Standard sample: STANDRAD SM-105 (Showa Denko Co., Ltd.)
Mobile phase: tetrahydrofuran Sample flow rate: 1 mL/min
Column temperature: 40°C

(Preparation of Curable Adhesive Acrylic Polymer)
A reactor equipped with a thermometer, a stirrer, and a cooling tube was prepared, and the raw material monomer mixture was added to the reactor. The raw material monomer mixture consisted of 79 parts by weight of 2-ethylhexyl acrylate (2EHA), 1 part by weight of acrylic acid (Aac), and 20 parts by weight of 2-hydroxyethyl acrylate (HEA). Furthermore, 80 parts by weight of ethyl acetate was added as a polymerization solvent. The reactor was heated to initiate reflux. Subsequently, 0.05 parts by weight of V-60 (2,2'-azobisisobutyronitrile, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was added as a polymerization initiator to the reactor, and polymerization was initiated under reflux. Two hours after the start of polymerization, 0.15 parts by weight of V-60 (2,2'-azobisisobutyronitrile, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was also added. The polymerization reaction was carried out under reflux for 8 hours from the start of polymerization, yielding a polymer-containing solution.
A reaction vessel was charged with 100 parts by weight of the obtained polymer, 10 ppm of hydroquinone, and 40 parts by weight of ethyl acetate, and the mixture was heated to 60° C. Subsequently, 8 parts by weight of 2-methacryloyloxyethyl isocyanate (MOI) was added dropwise to the reaction vessel over 60 minutes, and the mixture was allowed to react at 60° C. for a further 120 minutes, thereby obtaining a solution containing a pressure-sensitive adhesive component (boiling point free radical polymerized acrylic polymer, Mw: 601,000, Mw/Mn: 5.3).

(Preparation of Silicone-Based Graft Copolymer (Synthesis Example 1))
A reactor equipped with a thermometer, a stirrer, and a cooling tube was prepared. 89 parts by weight of 2-ethylhexyl acrylate, 10 parts by weight of silicone macromonomer, 1 part by weight of acrylamide, 0.6 parts by weight of lauryl mercaptan, and 80 parts by weight of ethyl acetate were added to the reactor, and the reactor was heated to initiate reflux. Subsequently, 0.01 parts by weight of 1,1-bis(t-hexylperoxy)-3,3,5-trimethylcyclohexane was added as a polymerization initiator to initiate polymerization under reflux. Next, 0.01 parts by weight of 1,1-bis(t-hexylperoxy)-3,3,5-trimethylcyclohexane was added one hour and two hours after the start of polymerization, and then 0.05 parts by weight of t-hexylperoxypivalate was added four hours after the start of polymerization to continue the polymerization reaction. Then, 8 hours after the start of polymerization, a silicone graft copolymer (Synthesis Example 1) (Mw: 60,000, Mw/Mn: 2.4) was obtained.

The glass transition temperature of the silicone graft copolymer (Synthesis Example 1) was determined as follows.
The glass transition temperature of a 5 mg measurement sample of the silicone graft copolymer (Synthesis Example 1) placed in an aluminum sample container (Hitachi High-Tech Science Corporation, Al autosampler sample container, φ6.8) was measured under a nitrogen atmosphere (nitrogen flow, flow rate 50 mL/min). The measurement was performed using a differential scanning calorimetry (Hitachi High-Tech Science Corporation, SII Exstar 6000/DSC 6220) from −100°C to 100°C at a heating rate of 10°C/min to determine the glass transition temperature (value for the first run) of the silicone graft copolymer (Synthesis Example 1).

Furthermore, the 5% weight loss temperature of the silicone graft copolymer (Synthesis Example 1) was determined as follows.
A 10 mg sample of the silicone-based graft copolymer (Synthesis Example 1) placed in a platinum sample container (Hitachi High-Tech Science Corporation, Pt open-type sample container, φ5.2, H2.5 mm) was measured for its 5% weight loss temperature under a nitrogen atmosphere (nitrogen flow, flow rate 50 mL/min). The measurement was performed using a simultaneous differential thermal and thermogravimetric analyzer (Hitachi High-Tech Science Corporation, TG-DTA; STA7200), in which the sample was heated from 25°C at a heating rate of 10°C/min, and the weight loss was measured. The weight loss rate was calculated from the obtained weight loss amount and the weight before heating, and the temperature at which the weight loss rate reached 5% was defined as the 5% weight loss temperature.

Furthermore, the silicon element content of the silicone graft copolymer (Synthesis Example 1) was determined as follows.
1 g of a measurement sample of the silicone-based graft copolymer (Synthesis Example 1) was weighed into a platinum crucible, sulfuric acid was added, and the sample was heated to 450 ° C on a hot plate to be incinerated. The ash was melted using a mixed melting agent of sodium carbonate and boric acid, and water was added and dissolved by heating. After that, a hydrochloric acid solution was added to adjust the pH. The silicon content of this solution was measured using an ICP emission spectrometer (OPTIMA 8300, manufactured by PerkinElmer Japan) to determine the silicon content in the silicone-based graft copolymer (Synthesis Example 1).

Furthermore, the content of low molecular weight components in the silicone graft copolymer (Synthesis Example 1) was determined as follows.
A tetrahydrofuran solution of the silicone-based graft copolymer (Synthesis Example 1) was filtered through a filter (material: polytetrafluoroethylene, pore diameter: 0.2 μm). The obtained filtrate was supplied to a gel permeation chromatograph (Waters, 2690 Separations Model), and GPC measurement was performed under conditions of a sample flow rate of 1 mL/min and a column temperature of 40°C. The polystyrene-equivalent molecular weight of the silicone-based graft copolymer (Synthesis Example 1) was measured, and the content and molecular weight of low molecular weight components were determined. A GPC KF-806L (Showa Denko KK) was used as the column, tetrahydrofuran was used as the mobile phase, and a differential refractometer was used as the detector.

(Preparation of Silicone-Based Graft Copolymers (Synthesis Examples 2 to 19))
Silicone graft copolymers (Synthesis Examples 2 to 19) were obtained in the same manner as in the preparation of the silicone graft copolymer (Synthesis Example 1), except that the monomer compositions were as shown in Table 1.

(Preparation of Silicone-Based Graft Copolymer (Synthesis Example 20))
A reactor equipped with a thermometer, stirrer, dropping funnel, and condenser was prepared. 90 parts by weight of ion-exchanged water, 10 parts by weight of emulsifier (Eleminol JS-20, manufactured by Sanyo Chemical Industries, Ltd.), and 0.1 parts by weight of ammonium persulfate were added to the reactor, and the mixture was then saturated with nitrogen gas. 80 parts by weight of 2-ethylhexyl acrylate, 10 parts by weight of silicone macromonomer, 10 parts by weight of 4-hydroxybutyl acrylate, 0.6 parts by weight of lauryl mercaptan, and 60 parts by weight of ion-exchanged water were mixed in a pipeline mixer to obtain a suspension with an oil droplet diameter of 0.5 μm or less. The internal temperature of the reactor was raised to 80°C, 0.4 parts by weight of ammonium persulfate was added, and the dropwise addition of the suspension was initiated 5 minutes later. The suspension was added dropwise over 2 hours, and the polymerization reaction was continued for another 2 hours. Then, 4 hours after the start of polymerization, the mixture was cooled and the pH was adjusted to 8-9 with ammonia to obtain a silicone graft copolymer (Synthesis Example 20).

2EHA: 2-(ethylhexyl) acrylate, BA: n-butyl acrylate, ISTA: isostearyl acrylate, MA: methyl acrylate, STA: stearyl acrylate, IBOA: isobornyl acrylate, MMA: methyl methacrylate, M2EHA: 2-(ethylhexyl) methacrylate, silicone macromonomer: one-terminal methacryloyl-modified polydimethylsiloxane (manufactured by Shin-Etsu Chemical Co., Ltd., weight-average molecular weight 4600)
AAc: acrylic acid AAm: acrylamide 4HBA: 4-hydroxybutyl acrylate AOI-BP: 2-[(3,5-dimethylpyrazolyl)carbonylamino]ethyl acrylate

Example 1
To 100 parts by weight of the solid content of the obtained adhesive component-containing solution, 5 parts by weight of a silicone-based graft copolymer (Synthesis Example 1) as a release aid and 3.0 parts by weight of an epoxy-based crosslinker were added to obtain an adhesive composition solution. Next, the adhesive composition solution was applied to the release-treated surface of a polyethylene terephthalate film whose surface had been subjected to a release treatment with a doctor knife so that the dry film thickness was 40 μm, and then heated and dried at 110 ° C for 5 minutes to obtain an adhesive layer. The obtained adhesive layer was bonded to the corona-treated surface of a 25 μm-thick transparent polyethylene naphthalate film whose one side had been corona-treated, to obtain an adhesive tape. The following crosslinking agents were used.
Epoxy crosslinking agent: Tetrad C, manufactured by Mitsubishi Gas Chemical Company, Inc.

(Examples 2 to 23, Comparative Examples 1 to 8)
Pressure-sensitive adhesive tapes were obtained in the same manner as in Example 1, except that the types and blending amounts of the release aids and the types and blending amounts of the crosslinking agents used were as shown in Tables 2 and 3. The following release aids and isocyanate-based crosslinking agents were used.
Silicone oil: KF-96-10cs, manufactured by Shin-Etsu Chemical Co., Ltd. Epoxy-modified silicone oil: X-22-163C, manufactured by Shin-Etsu Chemical Co., Ltd. Silicone oil graft copolymer: Cymac US-270, manufactured by Toagosei Co., Ltd. Isocyanate-based crosslinking agent: Coronate L45, manufactured by Nippon Polyurethane Co., Ltd. Thermal polymerization initiator: Perbutyl O, manufactured by NOF Corporation Photopolymerization initiator: Omnirad 369, manufactured by IGM Resins

<Evaluation>
The pressure-sensitive adhesive tapes obtained in the examples and comparative examples were evaluated by the following methods.
The results are shown in Tables 2 and 3.

(1) Measurement of initial adhesive strength and adhesive strength after heating: The adhesive tape was cut into a width of 25 mm to obtain a test piece. The adhesive layer of the obtained test piece was placed on a glass plate (manufactured by Matsunami Glass Industrial Co., Ltd., large slide glass with white edge polished No. 2). Next, the test piece and the glass plate were bonded together by rolling a 2 kg rubber roller back and forth on the test piece at a speed of 300 mm/min. The test piece was then left to stand at 23°C for 1 hour to prepare a test sample. After standing, the test sample was subjected to a 180° tensile test at a peel rate of 300 mm/min in accordance with JIS Z0237:2009 to measure the initial adhesive strength.
Next, the test samples prepared in the same manner as above were subjected to a heat treatment at 220°C for 2 hours. After cooling, a tensile test in the 180° direction was performed in the same manner as above, and the adhesive strength after heating was measured. The initial adhesive strength and the adhesive strength after heating were evaluated according to the following criteria. In Example 18, since the adhesive layer was a photocurable type, an ultra-high pressure mercury lamp was irradiated from the glass plate side at an intensity of 20 mW/ ^cm2 for 150 seconds before the heat treatment.

Initial adhesive strength ◎: Initial adhesive strength is 1.0 N/25 mm or more ○: Less than 1.0 N/25 mm, 0.10 N/25 mm or more △: Less than 0.10 N/25 mm

Adhesion strength after heating ◎: Adhesion strength after heating is less than 0.3 N/25 mm ○: 0.3 N/25 mm or more and less than 0.6 N/25 mm △: 0.6 N/25 mm or more and less than 1.0 N/25 mm ×: 1.0 N/25 mm or more

(2) Evaluation of Delamination Resistance (High-Temperature Delamination Resistance) and Contamination Resistance: Test pieces were obtained by cutting the adhesive tape into 25 mm widths. Under an environment of room temperature 23°C and relative humidity 50%, the adhesive layer of the obtained test piece was placed on a glass plate (large slide glass with white edges, No. 2, manufactured by Matsunami Glass Industrial Co., Ltd.) and attached using a 2 kg rubber roller at a speed of 10 mm/min. The obtained laminate was subjected to a heat treatment once at 280°C for 60 minutes. The state of the laminate after cooling was visually observed. Note that in Example 18, since the adhesive layer was photocurable, an ultra-high pressure mercury lamp was irradiated from the glass plate side at an intensity of 20 mW/ ^cm² for 150 seconds before the heat treatment.
The delamination resistance (delamination resistance (high temperature)) was evaluated according to the following criteria.
○: After heat treatment, the test piece did not peel off from the glass plate. ×: After heat treatment, the test piece peeled off from the glass plate.

After the test piece was peeled off from the glass plate, the glass plate was visually observed and the staining was evaluated according to the following criteria.
◎: No residue on the glass plate ○: Residue on part of the glass plate (10% or less of the test piece attached area)
×: Residue was found on most of the glass plate (wider than 10% of the test piece attached area)

The present invention provides a silicone-based graft copolymer that can form a pressure-sensitive adhesive layer that is resistant to peeling even when subjected to a high-temperature heat treatment process, and that can enhance adhesion and prevent contamination of the adherend. The present invention also provides a pressure-sensitive adhesive composition and pressure-sensitive adhesive tape that contain the silicone-based graft copolymer, as well as a method for manufacturing a semiconductor device.

1 Ring frame 2 Adhesive tape 3 Semiconductor wafer 4 Semiconductor chip

Claims (17)

a structure derived from a polar functional group-containing monomer, a structure derived from a silicone macromonomer, a structure derived from an alkyl acrylate ester, and a structure derived from a monomer containing a functional group crosslinkable with the polar functional group ;
the composition contains 0.1% by weight or more and 30% by weight or less of a structure derived from the polar functional group-containing monomer and 1% by weight or more and 90% by weight or less of a structure derived from the silicone macromonomer,
The weight average molecular weight is 5,000 or more and 200,000 or less,
The glass transition temperature is -80°C or higher and 30°C or lower, and the 5% weight loss temperature is 300°C or higher and 400°C or lower,
The glass transition temperature is a first-run measurement value obtained by differential scanning calorimetry using 5 mg of a measurement sample, under conditions of a nitrogen atmosphere (nitrogen flow, flow rate 50 mL/min) and a temperature rise rate of 10°C/min from -100°C to 100°C,
The 5% weight loss temperature is a temperature at which a weight loss rate calculated from the weight loss obtained by measuring a 10 mg measurement sample from 25°C under conditions of a nitrogen atmosphere (nitrogen flow, flow rate 50 mL/min) at a heating rate of 10°C/min using differential thermal and thermogravimetry, and the weight loss rate is 5% when calculated from the weight loss obtained and the weight before heating.
Silicone graft copolymer. The silicone-based graft copolymer according to claim 1, wherein the polar functional group-containing monomer is a hydroxyl group-containing monomer. The silicone graft copolymer according to claim 1 or 2, having a silicon element content of 1% by weight or more and 30% by weight or less. 4. The silicone graft copolymer according to claim 1 , wherein the monomer containing a functional group capable of crosslinking with a polar functional group has a protecting group bonded to the functional group capable of crosslinking with the polar functional group. 5. The silicone graft copolymer of claim 1, wherein the content of components having a weight average molecular weight of 3,000 or less as measured by gel permeation chromatography is 10% by weight or less. 6. A pressure-sensitive adhesive composition comprising the silicone graft copolymer according to claim 1, 2, 3 , 4 or 5 , a pressure-sensitive adhesive component having a functional group capable of crosslinking with said silicone graft copolymer, and a crosslinking agent. A pressure-sensitive adhesive composition comprising a silicone graft copolymer, a pressure-sensitive adhesive component having a functional group capable of crosslinking with the silicone graft copolymer, and a crosslinking agent,
the silicone graft copolymer has a structure derived from a polar functional group-containing monomer, a structure derived from a silicone macromonomer, and a structure derived from an alkyl acrylate;
the silicone graft copolymer contains 0.1% by weight or more and 30% by weight or less of a structure derived from the polar functional group-containing monomer and 1% by weight or more and 90% by weight or less of a structure derived from the silicone macromonomer, has a weight average molecular weight of 5,000 or more and 200,000 or less, a glass transition temperature of −80° C. or more and 30° C. or less, and a 5% weight loss temperature of 300° C. or more and 400° C. or less;
The glass transition temperature is a first-run measurement value obtained by differential scanning calorimetry using 5 mg of a measurement sample, under conditions of a nitrogen atmosphere (nitrogen flow, flow rate 50 mL/min) and a temperature rise rate of 10°C/min from -100°C to 100°C,
The 5% weight loss temperature is a temperature at which a weight loss rate calculated from the weight loss obtained by measuring a 10 mg measurement sample from 25°C under conditions of a nitrogen atmosphere (nitrogen flow, flow rate 50 mL/min) at a heating rate of 10°C/min using differential thermal and thermogravimetry, and the weight loss rate is 5% when calculated from the weight loss obtained and the weight before heating.
Pressure-sensitive adhesive composition . 8. The pressure-sensitive adhesive composition according to claim 6 , wherein the pressure-sensitive adhesive component having a functional group capable of crosslinking with the silicone graft copolymer is a curable pressure-sensitive adhesive (meth)acrylic polymer. The pressure-sensitive adhesive composition of claim 8, which does not contain a polymerization initiator. 8. The pressure-sensitive adhesive composition according to claim 6, wherein the content of the silicone graft copolymer is 0.1 parts by weight or more and 20 parts by weight or less per 100 parts by weight of the pressure-sensitive adhesive component. 6. An adhesive tape comprising a substrate and an adhesive layer laminated on at least one surface of the substrate, wherein the adhesive layer contains the silicone graft copolymer according to claim 1 . The adhesive tape according to claim 11, which is used in the processing of semiconductor wafers or semiconductor chips. An adhesive tape having a substrate and an adhesive layer laminated on at least one surface of the substrate, the adhesive tape being used in a processing step of a semiconductor wafer or a semiconductor chip,
the pressure-sensitive adhesive layer contains a silicone-based graft copolymer,
the silicone graft copolymer has a structure derived from a polar functional group-containing monomer, a structure derived from a silicone macromonomer, and a structure derived from an alkyl acrylate;
the silicone graft copolymer contains 0.1% by weight or more and 30% by weight or less of a structure derived from the polar functional group-containing monomer and 1% by weight or more and 90% by weight or less of a structure derived from the silicone macromonomer, has a weight average molecular weight of 5,000 or more and 200,000 or less, a glass transition temperature of −80° C. or more and 30° C. or less, and a 5% weight loss temperature of 300° C. or more and 400° C. or less;
The glass transition temperature is a first-run measurement value obtained by differential scanning calorimetry using 5 mg of a measurement sample, under conditions of a nitrogen atmosphere (nitrogen flow, flow rate 50 mL/min) and a temperature rise rate of 10°C/min from -100°C to 100°C,
The 5% weight loss temperature is a temperature at which a weight loss rate calculated from the weight loss obtained by measuring a 10 mg measurement sample from 25°C under conditions of a nitrogen atmosphere (nitrogen flow, flow rate 50 mL/min) at a heating rate of 10°C/min using differential thermal and thermogravimetry, and the weight loss rate is 5% when calculated from the weight loss obtained and the weight before heating.
Adhesive tape . 14. The adhesive tape according to claim 12, which is attached to a ring frame and a semiconductor wafer to be used as a protective tape for protecting the semiconductor wafer during processing steps of the semiconductor wafer. A method for manufacturing a semiconductor device, comprising a process for processing a semiconductor wafer or semiconductor chip using the adhesive tape of claim 11. 16. A method for manufacturing a semiconductor device according to claim 15 , comprising the steps of: attaching the adhesive tape according to claim 11 to a ring frame and a semiconductor wafer; and dicing the semiconductor wafer to obtain semiconductor chips. A method for manufacturing a semiconductor device, comprising a process for processing a semiconductor wafer or a semiconductor chip using an adhesive tape,
The pressure-sensitive adhesive tape has a substrate and a pressure-sensitive adhesive layer laminated on at least one surface of the substrate,
the pressure-sensitive adhesive layer contains a silicone-based graft copolymer,
the silicone graft copolymer has a structure derived from a polar functional group-containing monomer, a structure derived from a silicone macromonomer, and a structure derived from an alkyl acrylate;
the silicone graft copolymer contains 0.1% by weight or more and 30% by weight or less of a structure derived from the polar functional group-containing monomer and 1% by weight or more and 90% by weight or less of a structure derived from the silicone macromonomer, has a weight average molecular weight of 5,000 or more and 200,000 or less, a glass transition temperature of −80° C. or more and 30° C. or less, and a 5% weight loss temperature of 300° C. or more and 400° C. or less;
The glass transition temperature is a first-run measurement value obtained by differential scanning calorimetry using 5 mg of a measurement sample, under conditions of a nitrogen atmosphere (nitrogen flow, flow rate 50 mL/min) and a temperature rise rate of 10°C/min from -100°C to 100°C,
The 5% weight loss temperature is a temperature at which a weight loss rate calculated from the weight loss obtained by measuring a 10 mg measurement sample from 25°C under conditions of a nitrogen atmosphere (nitrogen flow, flow rate 50 mL/min) at a heating rate of 10°C/min using differential thermal and thermogravimetry, and the weight loss rate is 5% when calculated from the weight loss obtained and the weight before heating.
A method for manufacturing a semiconductor device .