JP2020184612A - Pressure-sensitive adhesive tape - Google Patents

Abstract

To provide a pressure-sensitive adhesive tape that achieves both an easy release property and an adhesion property capable of sufficiently fixing an adherend.SOLUTION: The pressure-sensitive adhesive tape has a pressure-sensitive adhesive layer containing a silicone compound. After a surface of the pressure-sensitive adhesive layer is irradiated with the UV of 405 nm such that the amount of irradiation of the pressure-sensitive adhesive layer surface is 2500 mJ/cm2, a Si ionic strength ratio 0 (Si ionic strength/total ionic strength) of the pressure-sensitive adhesive layer surface is measured using the TOF-SIMS. Subsequently, sputtering is applied once to the surface portion of the pressure-sensitive adhesive layer of which the Si ionic strength ratio 0 is measured, and then a Si ionic strength ratio 1 is measured using the TOF-SIMS. Subsequently, the sputtering and measurement step is performed n times to obtain Si ionic strength ratios 0 to n. Then, the ratio (A/B) of the average (A) for the Si ionic strength ratios 1 to 5 to the average (B) for the Si ionic strength ratios 20 to 25 is from 1.1 to 3.0 inclusive.SELECTED DRAWING: None

Description

The present invention relates to an adhesive tape.

In the manufacture of electronic components such as semiconductor packages, each member may be temporarily fixed with adhesive tape. For example, in the manufacture of a semiconductor package, dicing is performed to divide a large number of unseparated semiconductor packages made on a wafer into individualized semiconductor packages. At that time, an adhesive tape (dicing tape) is used to prevent the semiconductor package from being displaced or damaged. For example, Patent Document 1 has a photocurable pressure-sensitive adhesive layer, and by setting the breaking elongation rate of the pressure-sensitive adhesive layer before curing within a specific range, dicing that can suppress chip skipping and ensure excellent pick-up performance. The tape is disclosed.

JP 2015-149398

On the other hand, communication devices such as mobile phones are becoming higher in frequency due to higher speed of communication and an increase in the amount of information to be handled, and there is a problem that noise due to this high frequency causes a malfunction of a semiconductor package. In particular, in recent years, communication devices have been miniaturized, resulting in an increase in device density and a decrease in device voltage. As a result, semiconductor packages are more susceptible to noise due to high frequencies, and the problem of malfunction has become more prominent. There is.
To solve this problem, a method of blocking high frequencies by covering the semiconductor package with a metal film by sputtering has been proposed. In the method for manufacturing a semiconductor package having such a sputtering step, an adhesive tape is attached to the semiconductor package as a protective tape, dicing is performed, and then sputtering is performed. After sputtering is performed, it is peeled off from the adhesive tape by a needle pickup or the like.

When the process from dicing to pickup is performed as a series of steps with the adhesive tape attached, the dicing requires adhesion that can securely fix the semiconductor package, while the pickup must be lightly peeled to prevent pickup failure. Is required. However, since there is a trade-off relationship between adhesiveness and light peelability, it is difficult to obtain an adhesive tape having both adhesiveness and light peelability.

An object of the present invention is to provide an adhesive tape having both adhesiveness capable of sufficiently fixing an adherend and light peelability.

The present invention is an adhesive tape having an adhesive layer containing a silicone compound, and irradiates the surface of the adhesive layer with ultraviolet rays of 405 nm so that the amount of irradiation on the surface of the adhesive layer is 2500 mJ / cm ^2. Then, TOF-SIMS was used to measure the Si ionic strength ratio 0 (Si ionic strength / total ionic strength) on the surface of the pressure-sensitive adhesive layer, and then on the surface portion of the pressure-sensitive adhesive layer on which the Si ionic strength ratio 0 was measured. After performing one sputtering, the Si ion intensity ratio 1 was measured using TOF-SIMS, and then the sputtering and measurement steps were performed n times to obtain a Si ion intensity ratio of 0 to n. With an adhesive tape, the ratio (A / B) of the average value (A) of the strength ratio 1 to 5 and the average value (B) of the Si ion intensity ratio 20 to 25 is 1.1 or more and 3.0 or less. is there.
The present invention will be described in detail below.

The pressure-sensitive adhesive tape of the present invention has a pressure-sensitive adhesive layer containing a silicone compound, and after irradiating the surface of the pressure-sensitive adhesive layer with ultraviolet rays of 405 nm so that the amount of irradiation on the surface of the pressure-sensitive adhesive layer is 2500 mJ / cm ² . The Si ionic strength ratio 0 (Si ionic strength / total ionic strength) of the surface of the pressure-sensitive adhesive layer was measured using TOF-SIMS, and then sputtering was performed once on the surface portion of the pressure-sensitive adhesive layer where the Si ionic strength ratio of 0 was measured. After that, the Si ionic strength ratio 1 was measured using TOF-SIMS, and then the above sputtering and measurement steps were performed n times to obtain a Si ionic strength ratio of 0 to n. The ratio (A / B) of the average value (A) of ~ 5 to the average value (B) of the Si ion intensity ratio of 20 to 25 is 1.1 or more and 3.0 or less.
In the above measurement, TOF-SIMS plays a role of indicating the amount of the silicone release agent present on the surface of the pressure-sensitive adhesive layer in the form of an ionic strength ratio, and sputtering plays a role of scraping the surface of the pressure-sensitive adhesive layer in the thickness direction. .. By performing the above measurement, the distribution of the release agent in the thickness direction of the pressure-sensitive adhesive layer of the pressure-sensitive adhesive tape can be obtained. The average value of the Si ion strength ratios 1 to 5, that is, the amount of the release agent near the surface of the pressure-sensitive adhesive layer and the average value of the Si ion strength ratios of 20 to 25, that is, the release agent inside the pressure-sensitive adhesive layer. When the ratio to the amount of the adhesive is in the above range, the adhesive tape can be easily peeled off when the adhesive tape is no longer needed, while exhibiting the adhesiveness capable of sufficiently fixing the adherend. When the A / B is less than 1.1, the release agent is not sufficiently bleeded out to the interface with the adherend, so that the peelability is lowered, and the A / B is 3.0 or more. Then, the amount of the release agent present at the interface with the adherend becomes too large, and the adhesion is lowered. From the viewpoint of achieving both adhesion and light peelability, the A / B is preferably 1.2 or more, more preferably 1.3 or more, still more preferably 1.4 or more. It is even more preferably 1.6 or more, particularly preferably 1.8 or more, preferably 2.9 or less, more preferably 2.8 or less, and 2.6 or less. It is more preferably 2.4 or less, and even more preferably 2.4 or less. The A / B can be adjusted by the type of the pressure-sensitive adhesive, the type of the release agent, and the method of manufacturing the pressure-sensitive adhesive tape. For example, when an acrylic pressure-sensitive adhesive is used as the pressure-sensitive adhesive, the silicone compound works effectively, so that the above A / B can be easily satisfied. As for the manufacturing method, the A / B can be adjusted according to conditions such as drying conditions and curing conditions at the time of manufacturing the adhesive tape.

Time-of-flight secondary ion mass spectrometry (TOF-SIMS: Time-of-Flight Second Method Ion Mass Spectrometry) irradiates a solid sample with an ion beam (primary ion) and emits ions (secondary ions) from the surface. Is a method of mass spectrometry using the flight time difference (the flight time is proportional to the square root of the weight). With TOF-SIMS, spectral information on elements and molecular species existing in a region of 1 nm in the thickness direction from the sample surface can be obtained with high detection sensitivity.

Sputtering involves ejecting a high-pressure gas such as argon in a vacuum, ionizing the formed gas clusters, oxygen, cesium, etc., and irradiating the surface of the target with an ion beam at high speed. ~ Can be cut to a depth on the order of micrometer.

It is possible to obtain a depth profile from the spectral information obtained by alternately repeating the sputtering and the TOF-SIMS measurement. Specifically, the measured values are plotted with the number of sputterings on the horizontal axis and the intensity ratio of secondary ions in the number of sputterings on the vertical axis, and the relationship between the number of sputterings and the secondary ion intensity ratio is graphed. A depth profile can be obtained, and the distribution of each ion in the depth direction from the surface of the pressure-sensitive adhesive layer can be evaluated.
Examples of the analyzer used for TOF-SIMS include "PHInanoTOFII" manufactured by ULVAC-PHI. Further, in the above measurement, the Si ion intensity ratio uses a Bi ₃ ⁺⁺ ion gun (voltage: 30 KV, current: 0.5 μA) as the primary ion source for measurement, and argon cluster ions (voltage: 5 KV, 5 nA) for sputtering. The measurement is performed using the dual beam method using the sputter source (secondary ion source) of.
Here, as the argon gas cluster ion, an argon gas cluster ion is used in which about several thousand argon atoms are gathered to form a cluster.

The average value of the Si ion intensity ratios 1 to 5 is preferably 0.001 or more and 0.03 or less.
When the average value of the Si ion intensity ratio near the surface of the pressure-sensitive adhesive layer is in the above range, it is easy to adjust to the above range of A / B, and it is possible to make it easier to achieve both adhesion and light peelability. it can. From the viewpoint of making it easier to achieve both adhesion and light peelability, the average value of the Si ion intensity ratios 1 to 5 is more preferably 0.002 or more, further preferably 0.003 or more. It is even more preferably 0.006 or more, more preferably 0.025 or less, further preferably 0.02 or less, and even more preferably 0.015 or less.

The pressure-sensitive adhesive (hereinafter, simply referred to as a pressure-sensitive adhesive) constituting the pressure-sensitive adhesive layer is not particularly limited, and may contain either a non-curable type pressure-sensitive adhesive or a curable type pressure-sensitive adhesive. Specifically, for example, rubber-based adhesives, acrylic-based adhesives, vinyl alkyl ether-based adhesives, silicone-based adhesives, polyester-based adhesives, polyamide-based adhesives, urethane-based adhesives, styrene-diene block copolymerization systems. Adhesives and the like can be mentioned. Among them, an acrylic pressure-sensitive adhesive is preferable because it easily satisfies the above A / B, and an acrylic-based curable pressure-sensitive adhesive is more preferable.

Examples of the curable pressure-sensitive adhesive include a photo-curable pressure-sensitive adhesive that is crosslinked and cured by light irradiation, a thermosetting pressure-sensitive adhesive that is cross-linked and cured by heating, and the like.
Examples of the photocurable pressure-sensitive adhesive include a photo-curable pressure-sensitive adhesive containing a polymerizable polymer as a main component and a photopolymerization initiator.
Examples of the thermosetting pressure-sensitive adhesive include a thermosetting pressure-sensitive adhesive containing a polymerizable polymer as a main component and a thermosetting initiator. Of these, a photocurable adhesive is preferable because it does not easily damage the adherend and can be easily cured.

For the polymerizable polymer, for example, a (meth) acrylic polymer having a functional group in the molecule (hereinafter, referred to as a functional group-containing (meth) acrylic polymer) is synthesized in advance and reacts with the functional group in the molecule. It can be obtained by reacting a functional group to be subjected to a compound having a radically polymerizable unsaturated bond (hereinafter referred to as a functional group-containing unsaturated compound).

The functional group-containing (meth) acrylic polymer includes an acrylic acid alkyl ester and / or a methacrylic acid alkyl ester in which the number of carbon atoms of the alkyl group is usually in the range of 2 to 18, a functional group-containing monomer, and further, if necessary. It is obtained by copolymerizing these with another copolymerizable monomer for modification. 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 a carboxyl group-containing monomer such as acrylate and methacrylic acid, a hydroxyl group-containing monomer such as hydroxyethyl acrylate and hydroxyethyl methacrylate, and an epoxy such as glycidyl acrylate and glycidyl methacrylate. Group-containing monomers can be mentioned. Further, isocyanate group-containing monomers such as isocyanate ethyl acrylate and ethyl methacrylate and amino group-containing monomers such as aminoethyl acrylate and aminoethyl methacrylate can also be mentioned.

Examples of the other copolymerizable monomer for modification include various monomers used in general (meth) acrylic polymers such as vinyl acetate, acrylonitrile, and styrene.

As the functional group-containing unsaturated compound to be reacted with the functional group-containing (meth) acrylic polymer, the same one as the above-mentioned functional group-containing monomer is used depending on 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. 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. When the functional group is an amino group, an epoxy group-containing monomer is used.

In order to obtain the above-mentioned polymerizable polymer, the raw material monomer may be radically reacted in the presence of a polymerization initiator. As a method of radically reacting the raw material monomer, that is, a polymerization method, a conventionally known method is used, and examples thereof include solution polymerization (boiling point polymerization or constant temperature polymerization), emulsion polymerization, suspension polymerization, and bulk polymerization.
The polymerization initiator used in the radical reaction for obtaining the above-mentioned polymerizable polymer is not particularly limited, and examples thereof include organic peroxides and azo compounds. Examples of the organic peroxide include 1,1-bis (t-hexyl peroxy) -3,3,5-trimethylcyclohexane, t-hexyl peroxypivalate, t-butylperoxypivalate, 2,5. -Dimethyl-2,5-bis (2-ethylhexanoylperoxy) hexane, t-hexylperoxy-2-ethylhexanoate, t-butylperoxy-2-ethylhexanoate, t-butylperoxy Examples thereof include isobutyrate, t-butylperoxy-3,5,5-trimethylhexanoate and t-butylperoxylaurate. Examples of the azo compound include azobisisobutyronitrile and azobiscyclohexanecarbonitrile. These polymerization initiators may be used alone or in combination of two or more.

Examples of the photopolymerization initiator include those that are activated by irradiating light having a wavelength of 250 to 800 nm. Examples of such a photopolymerization initiator include acetphenone derivative compounds such as methoxyacetophenone, benzoin ether compounds such as benzoin propyl ether and benzoin isobutyl ether, ketal derivative compounds such as benzyl dimethyl ketal and acetophenone diethyl ketal, and the like. Examples include phosphine oxide derivative compounds. Further, bis (η5-cyclopentadienyl) titanosen derivative compound, benzophenone, Michler ketone, chlorothioxanthone, todecylthioxanthone, dimethylthioxanthone, diethylthioxanthone, α-hydroxycyclohexylphenylketone, 2-hydroxymethylphenylpropane and the like can also be mentioned. These photopolymerization initiators may be used alone or in combination of two or more.

Examples of the thermal polymerization initiator include those that generate active radicals that are decomposed by heat and initiate polymerization curing. Specifically, for example, dicumyl peroxide, di-t-butyl peroxide, t-butylperoxybenzoale, t-butylhydroperoxide, benzoyl peroxide, cumenehydroperoxide, diisopropylbenzenehydroperoxide, etc. Examples thereof include paramentan hydroperoxide and di-t-butyl peroxide.
Of these thermal polymerization initiators, those commercially available are not particularly limited, but for example, perbutyl D, perbutyl H, perbutyl P, perpenta H (all of which are manufactured by NOF CORPORATION) and the like are suitable. These thermal polymerization initiators may be used alone or in combination of two or more.

The pressure-sensitive adhesive layer may further contain a radically polymerizable polyfunctional oligomer or monomer. By containing a radically polymerizable polyfunctional oligomer or monomer, photocurability and thermosetting are improved.
The polyfunctional oligomer or monomer preferably has a weight average molecular weight of 10,000 or less, and more preferably has a molecular weight of 5000 so that the pressure-sensitive adhesive layer can be efficiently reticulated by heating or irradiation with light. The number of radically polymerizable unsaturated bonds in the molecule is 2 to 20 below. In the present invention, the weight average molecular weight can be determined using gel permeation chromatography, for example, HSPgel HR MB-M 6.0 × 150 mm as the column, THF as the eluate, measured at 40 ° C. and polystyrene standard. Can be determined by.

The polyfunctional oligomer or monomer is, for example, trimethylolpropane triacrylate, tetramethylolmethanetetraacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol monohydroxypentaacrylate, dipentaerythritol hexaacrylate or the same methacrylate as above. Kind and the like. Other examples include 1,4-butylene glycol diacrylate, 1,6-hexanediol diacrylate, polyethylene glycol diacrylate, commercially available oligoester acrylate, and the same methacrylates as described above. These polyfunctional oligomers or monomers may be used alone or in combination of two or more.

The pressure-sensitive adhesive layer contains a silicone compound.
Since the pressure-sensitive adhesive layer contains a silicone compound, it prevents the pressure-sensitive adhesive layer from being scorched even when placed in a high-temperature environment of 200 ° C. or higher, and bleeds out to the interface of the adherend during peeling, facilitating peeling. can do. Further, since the silicone compound is distributed in the pressure-sensitive adhesive layer so as to satisfy the above-mentioned A / B, it is possible to obtain an adhesive tape having sufficient adhesion to an adherend and excellent light peelability. it can.

The silicone compound preferably has a functional group that can be crosslinked with the pressure-sensitive adhesive.
Since the silicone compound has a functional group that can be crosslinked with the pressure-sensitive adhesive, it chemically reacts with the pressure-sensitive adhesive by light irradiation or heating, and the silicone compound is incorporated into the pressure-sensitive adhesive. It is possible to prevent the silicone compound from adhering to the surface and contaminating it.

The silicone skeleton of the above silicone compound is not particularly limited, and may be either a D-form or a DT-form.
The silicone compound preferably has a functional group crosslinkable with the pressure-sensitive adhesive at the side chain or terminal of the silicone skeleton.
Among them, when a silicone compound having a D-form silicone skeleton and having a functional group crosslinkable with the above-mentioned adhesive at the end is used, it is treated with a chemical solution or at a high temperature of 200 ° C. or higher while exhibiting high adhesion. It can be peeled off without adhesive residue even after a while.

As the functional group crosslinkable with the pressure-sensitive adhesive, an appropriate one is selected and used according to the pressure-sensitive adhesive. For example, when the pressure-sensitive adhesive is a photocurable adhesive or a thermosetting adhesive containing a (meth) acrylic acid alkyl ester-based polymerizable polymer having a radically polymerizable unsaturated bond in the molecule as a main component. Select a (meth) acrylic group and a crosslinkable functional group.
The functional group crosslinkable with the (meth) acrylic group is a functional group having an unsaturated double bond, and specific examples thereof include a vinyl group, a (meth) acrylic group, an allyl group, and a maleimide group. ..

The functional group equivalent of the silicone compound is not particularly limited, but the preferred lower limit is 1 and the preferred upper limit is 20. When the functional group equivalent is 1 or more, the silicone compound is sufficiently incorporated into the pressure-sensitive adhesive, contamination of the adherend can be suppressed, and higher peelability can be exhibited. When the functional group equivalent is 20 or less, sufficient adhesive strength can be obtained. The more preferable upper limit of the functional group equivalent is 10, the more preferable lower limit is 2, and the more preferable upper limit is 6.

The weight average molecular weight of the silicone compound is not particularly limited, but the preferred lower limit is 300 and the preferred upper limit is 50,000. When the weight average molecular weight is 300 or more, chemical resistance and heat resistance are improved, and when it is 50,000 or less, mixing with the pressure-sensitive adhesive is good. The more preferable lower limit of the weight average molecular weight is 400, the more preferable upper limit is 10,000, the further preferable lower limit is 500, and the further preferable upper limit is 5000.

The method for synthesizing the silicone compound is not particularly limited, and for example, a silicone resin having a SiH group and a vinyl compound having a crosslinkable functional group with the pressure-sensitive adhesive are reacted by a hydrosyllation reaction to form a silicone resin. Examples thereof include a method of introducing a functional group that can be crosslinked with the pressure-sensitive adhesive. Further, a method of condensing the siloxane compound with the pressure-sensitive adhesive and a siloxane compound having a crosslinkable functional group can also be mentioned.

Commercially available silicone compounds include, for example, X-22-164, X-22-164AS, X-22-164A, X-22-164B, X-22-164C manufactured by Shin-Etsu Chemical Co., Ltd. Examples thereof include silicone compounds having methacryl groups at both ends, such as X-22-164E. Further, a silicone compound having a methacrylic group at one end such as X-22-174DX, X-22-2426, X-22-2475 manufactured by Shin-Etsu Chemical Co., Ltd., and an acrylic group such as EBECRYL350 and EBECRYL1360 manufactured by Daisel Cytec Co., Ltd. Also mentioned is a silicone compound having. Furthermore, silicone compounds having an acrylic group such as AC-SQ TA-100 and AC-SQ SI-20 manufactured by Toagosei Co., Ltd., and MAC-SQ TM-100, MAC-SQ SI-20 and MAC manufactured by Toagosei Co., Ltd. -Silicon compounds having a methacrylic group such as HDMI may also be mentioned.

Among them, the above-mentioned silicone compounds have particularly high chemical resistance and heat resistance, and because of their high polarity, bleeding out from the adhesive tape is easy. Therefore, the following general formulas (I), general formulas (II), and general formulas (II) are used. A silicone compound having a (meth) acrylic group in the siloxane skeleton represented by the formula (III) is suitable.

In the formula, X and Y each independently represent an integer from 0 to 1200 (except when both X and Y are 0), and R represents a functional group having an unsaturated double bond. ..

Among the silicone compounds represented by the general formula (I), the general formula (II), and the general formula (III) having a (meth) acrylic group in the siloxane skeleton, commercially available silicone compounds are manufactured by Daicel Cytec Co., Ltd., for example. EBECRYL350, EBECRYL1360 (both R is an acrylic group) and the like.

The content of the silicone compound is preferably 1 part by weight or more and 40 parts by weight or less with respect to 100 parts by weight of the pressure-sensitive adhesive.
When the content of the silicone compound is 1 part by weight or more, peeling from the adherend becomes easier, and when it is 40 parts by weight or less, contamination of the adherend can be further suppressed. From the viewpoint of further suppressing the peelability and stainability from the adherend, the content of the silicone compound is more preferably 10 parts by weight or more, and more preferably 30 parts by weight or less.

The pressure-sensitive adhesive layer may further contain an inorganic filler such as fumed silica. By blending an inorganic filler, the cohesive force of the pressure-sensitive adhesive layer is increased. Therefore, when the pressure-sensitive adhesive layer contains an inorganic filler such as fumed silica, the pressure-sensitive adhesive tape can be more easily peeled off from the adherend without leaving adhesive residue when the pressure-sensitive adhesive tape is no longer needed.

The pressure-sensitive adhesive layer preferably contains a cross-linking agent.
By containing the cross-linking agent, the cohesive force of the pressure-sensitive adhesive layer is enhanced, and the adhesive strength can be enhanced.
The above-mentioned cross-linking agent is not particularly limited, and examples thereof include isocyanate-based cross-linking agents, epoxy-based cross-linking agents, aziridine-based cross-linking agents, and metal chelate-based cross-linking agents. Of these, isocyanate-based cross-linking agents are preferable because they have higher adhesive strength.

The content of the cross-linking agent in the pressure-sensitive adhesive layer is preferably 0.1 part by weight or more and 20 parts by weight or less with respect to 100 parts by weight of the pressure-sensitive adhesive.
When the cross-linking agent is contained in the above range, the pressure-sensitive adhesive can be appropriately cross-linked to further enhance the adhesive strength. From the viewpoint of further enhancing the adhesive strength, the more preferable lower limit of the content of the cross-linking agent is 0.5 parts by weight, the more preferable lower limit is 1.0 part by weight, the more preferable upper limit is 15 parts by weight, and the further preferable upper limit is 10 parts by weight. Is.

The pressure-sensitive adhesive layer may contain known additives such as plasticizers, resins, surfactants, waxes, and fine particle fillers. The above additives may be used alone or in combination of two or more.

The pressure-sensitive adhesive layer preferably has a gel fraction of 44% or more and 67% or less.
When the gel fraction of the pressure-sensitive adhesive layer is within the above range, it can be attached to the adherend with sufficient adhesive strength, and the adherend can be more sufficiently fixed. From the viewpoint of improving the adhesive strength, the gel fraction of the pressure-sensitive adhesive layer is more preferably 47% or more, further preferably 50% or more, further preferably 64% or less, and more preferably 60%. The following is more preferable. When the pressure-sensitive adhesive is a curable pressure-sensitive adhesive, the gel fraction refers to the one before curing.

The thickness of the pressure-sensitive adhesive layer is not particularly limited, but a preferable lower limit is 5 μm and a preferable upper limit is 500 μm. When the thickness of the pressure-sensitive adhesive layer is within this range, it can be attached to the adherend with sufficient adhesive strength, and the adherend can be sufficiently fixed. From the viewpoint of improving the adhesive strength, the more preferable lower limit of the thickness of the pressure-sensitive adhesive layer is 10 μm, the further preferable lower limit is 15 μm, the more preferable upper limit is 300 μm, the further preferable upper limit is 250 μm, and the further preferable upper limit is 200 μm.

The adhesive tape of the present invention may be a support type having a base material or a non-support type having no base material. When the adhesive tape of the present invention is a support type having a base material, the base material constituting the base material layer is not particularly limited, but a base material having heat resistance is preferable. Examples of such a heat-resistant substrate include polyethylene terephthalate, polyethylene naphthalate, polyacetal, polyamide, polycarbonate, polyphenylene ether, polybutylene terephthalate, ultrahigh molecular weight polyethylene, syndiotactic polystyrene, polyarylate, polysulfone, and polyether. Examples thereof include sulfone, polyphenylene sulfide, polyether ether ketone, polyimide, polyetherimide, fluororesin, and liquid crystal polymer. Of these, polyethylene naphthalate is preferable because it has excellent heat resistance.

The base material preferably has a flexural rigidity in the TD direction at 23 ° C. of 2.38 × ^10-7 N ・ m ² or more and 2.98 × 10 ^-5 N ・ m ² or less.
When the flexural rigidity of the base material in the TD direction at 23 ° C. is within the above range, the adherend can be more reliably protected and an adhesive tape having excellent handleability can be obtained. The flexural rigidity of the base material in the TD direction at 23 ° C. is more preferably 4.12 × ^10-7 N ・ m ² or more, and further preferably 9.76 × 10 ^-7 N ・ m ² or more. , 2.03 × ^10-5 N · m ² or less, and more preferably 1.53 × 10 ^-5 N · m ² or less. Here, the TD (Transverse Direction) direction refers to a direction perpendicular to the extrusion direction when the base material is extruded into a sheet shape.
The flexural rigidity is represented by the product of the tensile elastic modulus E and the moment of inertia of area I. The tensile elastic modulus is measured using a viscoelastic spectrometer (for example, DVA-200, manufactured by IT Measurement Control Co., Ltd.) under the conditions of a constant speed temperature rise tensile mode, a temperature rise rate of 10 ° C./min, and a frequency of 10 Hz. can do. The moment of inertia of area I is expressed by the following equation.
I = (thickness of the tape base ^material) 3/12 ^{(m 2)}

The thickness of the base material layer is not particularly limited, but the preferable lower limit is 5 μm and the preferable upper limit is 200 μm. When the thickness of the base material layer is within this range, the adhesive tape has an appropriate elasticity and is excellent in handleability. A more preferable lower limit of the thickness of the base material layer is 10 μm, and a more preferable upper limit is 150 μm.

The method for producing the adhesive tape of the present invention is not particularly limited, and conventionally known methods can be used. For example, a pressure-sensitive adhesive solution containing the above-mentioned pressure-sensitive adhesive, the above-mentioned silicone compound, and, if necessary, an additive such as a cross-linking agent is applied to a film subjected to a mold release treatment and dried to form a pressure-sensitive adhesive layer. Can be manufactured by forming and bonding to a base material.

In the production of the pressure-sensitive adhesive tape of the present invention, the stirring speed performed when preparing the pressure-sensitive adhesive solution, the amount of heating when drying the pressure-sensitive adhesive layer, and the curing conditions after forming the pressure-sensitive adhesive tape are adjusted. It is possible to easily satisfy A / B. For example, when the stirring speed is increased, the silicone compound in the pressure-sensitive adhesive layer is dispersed more uniformly, and when the stirring speed is decreased, the silicone compound is less likely to be dispersed. Increasing the heating amount makes it difficult for the silicone compound in the pressure-sensitive adhesive layer to bleed, and decreasing the heating amount promotes bleeding of the silicone compound. When the curing conditions are high temperature and long time, bleeding of the silicone compound in the pressure-sensitive adhesive layer is promoted, and when the curing conditions are low temperature and short time, the silicone compound is less likely to bleed. By combining these conditions, the above A / B can be adjusted.

Since the adhesive tape of the present invention is excellent in adhesiveness and light peelability, it can be advantageously used for temporarily fixing electronic components. In particular, it can be advantageously used as an adhesive tape (temporary fixing adhesive tape for semiconductor manufacturing) for temporarily fixing members in semiconductor manufacturing. Specifically, dicing, sputtering, and pickup are used in semiconductor package manufacturing. It can be suitably used as a protective tape for protecting a semiconductor package when it is performed as a series of steps.

According to the present invention, it is possible to provide an adhesive tape having both adhesiveness capable of sufficiently fixing an adherend and light peelability.

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

(Preparation of main polymer)
A reactor equipped with a thermometer, a stirrer, and a cooling tube is prepared, and in this reactor, 94 parts by weight of 2-ethylhexyl acrylate, 1 part by weight of acrylic acid, 5 parts by weight of 2-hydroxyethyl acrylate, and 0 parts of lauryl mercapcaptan. After adding 0.01 part by weight and 180 parts by weight of ethyl acetate, the reactor was heated to start reflux. Subsequently, 0.01 part by weight of 1,1-bis (t-hexylperoxy) -3,3,5-trimethylcyclohexane was added as a polymerization initiator into the reactor, and the polymerization was started under reflux. It was. Next, 0.01 parts by weight of 1,1-bis (t-hexylperoxy) -3,3,5-trimethylcyclohexane was added 1 hour and 2 hours after the start of the polymerization, and further, the polymerization was started. After 4 hours from the above, 0.05 parts by weight of t-hexyl peroxypivalate was added to continue the polymerization reaction. Then, 8 hours after the start of the polymerization, an ethyl acetate solution of a functional group-containing (meth) acrylic polymer having a solid content of 55% by weight and a weight average molecular weight of 600,000 was obtained.
To 100 parts by weight of the resin solid content of the obtained ethyl acetate solution containing a functional group-containing (meth) acrylic polymer, 3.5 parts by weight of 2-isocyanatoethyl methacrylate was added as a functional group-containing unsaturated compound to react. Then, an ethyl acetate solution of the main polymer, which is a pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer, was obtained.

(Example 1)
1 part by weight of silicone compound, 3 parts by weight of filler, 10 parts by weight of urethane acrylate, 0.2 part by weight of cross-linking agent, 1 part by weight of photopolymerization initiator with respect to 100 parts by weight of solid content of the obtained ethyl acetate solution of the main polymer. Was added and mixed at a stirring rate of 100 rpm to obtain an adhesive solution. Next, the pressure-sensitive adhesive solution was applied on the release-treated surface of the polyethylene terephthalate film whose surface was subjected to the release treatment with a doctor knife so that the thickness of the dry film was 40 μm, and the film was dried by heating at 105 ° C. for 5 minutes. Obtained an adhesive layer. An adhesive tape was obtained by adhering the obtained adhesive layer and the corona-treated surface of the base material a having corona-treated one side, and curing at 40 ° C. for 6 days. The following materials were used as the base material a, the silicone compound, the filler, the urethane acrylate, the cross-linking agent, and the photopolymerization initiator.
Base material a: Polyethylene naphthalate, Q83-50, manufactured by Teijin Co., Ltd., thickness 50 μm, flexural rigidity in the TD direction at 23 ° C. 1.91 × ^10-6 N ・ m ²
Silicone compound: Silicon diacrylate, EBECRYL 350, manufactured by Daicel Ornex, weight average molecular weight 1000
Filler: Silica filler, Leoloseal MT-10, Urethane acrylate manufactured by Tokuyama Corporation: UN-5500, Cross-linking agent manufactured by Negami Kogyo Co., Ltd .: Isocyanate-based cross-linking agent, Coronate L, Photopolymerization initiator manufactured by Nippon Urethane Industry Co., Ltd .: Irgacure 369, BASF Made

(Examples 2 to 18, Comparative Examples 1 to 3)
An adhesive tape was obtained in the same manner as in Example 1 except that the amount of the release agent blended, the stirring speed at the time of preparing the pressure-sensitive adhesive solution, the amount of heating at the time of forming the pressure-sensitive adhesive layer, and the curing conditions were as shown in Tables 1 and 2. .. Specifically, the following materials were used as the base materials b and c. Further, in Example 2, no base material was used, and the adhesive layer was used as it was as an adhesive tape.
Base material b: Polyethylene terephthalate, Lumirror # 125-X6K7, manufactured by Toray Industries, Inc., thickness 125 μm, flexural rigidity in the TD direction at 23 ° C. 2.98 × ^10-5 N ・ m ²
Base material c: Polyethylene naphthalate, Q83-25, manufactured by Teijin Limited, thickness 25 μm, flexural rigidity in the TD direction at 23 ° C. 1.22 × ^10-7 N ・ m ²

<Physical properties>
The following measurements were performed on the adhesive tapes obtained in Examples and Comparative Examples.
The results are shown in Tables 1 and 2.

(Measurement of gel fraction of adhesive layer)
0.1 g of the adhesive layer of the obtained adhesive tape was scraped off, immersed in 50 ml of ethyl acetate, and shaken with a shaker at a temperature of 23 ° C. and 120 rpm for 24 hours (hereinafter, scraped non-scraped). The pressure-sensitive adhesive layer is called a pressure-sensitive adhesive composition). After shaking, a metal mesh (opening # 200 mesh) was used to separate the swelling pressure-sensitive adhesive composition by absorbing ethyl acetate and ethyl acetate. The adhesive composition after separation was dried under the condition of 110 ° C. for 1 hour. The weight of the pressure-sensitive adhesive composition containing the metal mesh after drying was measured, and the gel fraction of the pressure-sensitive adhesive layer was calculated using the following formula.
Gel fraction (% by weight) = 100 x (W _1- W ₂ ) / W ₀
(W ₀ : Weight of initial pressure-sensitive adhesive composition, W ₁ : Weight of pressure-sensitive adhesive composition including dried metal mesh, W ₂ : Initial weight of metal mesh)

(Measurement of A / B)
The surface of the pressure-sensitive adhesive layer of the obtained adhesive tape was irradiated with ultraviolet rays of 405 nm using a high-pressure mercury ultraviolet ray irradiator so that the irradiation amount on the surface of the pressure-sensitive adhesive layer was 2500 mJ / cm ² . Then, TOF-SIMS was measured on the surface of the pressure-sensitive adhesive layer using "PHInanoTOFII" manufactured by ULVAC-PHI, using a Bi ₃ ⁺⁺ ion gun as a primary ion source for measurement. From the obtained measurement results, a Si ionic strength ratio of 0 (Si ionic strength / total ionic strength) was obtained based on the peak having a mass number of 28 derived from the silicone compound.
Next, the surface portion of the pressure-sensitive adhesive layer on which the Si ion intensity ratio of 0 was measured was subjected to ion sputtering once using argon cluster ions (voltage: 5KV, 5nA) as a sputtering source (secondary ion source) for sputtering, and the above Si was performed. In the same manner as the ion intensity ratio of 0, TOF-SIMS was used to obtain a Si ion intensity ratio of 1. Then, sputtering and TOF-SIMS measurement were repeated to obtain a Si ion intensity ratio of 0 to 25.
From the obtained Si ionic strength ratios 0 to 25, the average value (A) of the Si ionic strength ratios 1 to 5 and the average value (B) of the Si ionic strength ratios 20 to 25 were calculated, and based on this, A / B Was calculated. The measurement conditions and sputtering conditions for TOF-SIMS are as follows.

(Measurement conditions for TOF-SIMS)
Equipment: PHI nanoTOFII manufactured by ULVAC-PHI
Primary ion: 30KV, Bi ₃ ⁺⁺ , 0.5μA (current value)
Primary ion scan range (measurement area): 200 μm × 200 μm
Secondary ion detection mode: negative
Number of scans: 3scan / time Charge correction: E-Neut + I-Neut

(Sputtering conditions)
Spatter ion: Argon cluster ion (5KV, 5nA)
Sputtering time: 10s / time Sputtering area: 800 μm x 800 μm

<Evaluation>
The adhesive tapes obtained in Examples and Comparative Examples were evaluated by the following methods.
The results are shown in Tables 1 and 2.

(Manufacturing of semiconductor packages)
The obtained adhesive tape was attached to a semiconductor package having a size of 70 × 150 mm and already sealed with a mold resin. Next, the pressure-sensitive adhesive layer was crosslinked and cured by irradiating the surface of the pressure-sensitive adhesive layer with ultraviolet rays of 405 nm using a high-pressure mercury ultraviolet irradiation machine so that the irradiation amount on the surface of the pressure-sensitive adhesive layer was 2500 mJ / cm ² . Next, the adhesive tape and the package were diced and cut so as to have a size of 15 × 8 mm. Next, the semiconductor package was sputtered under normal sputtering conditions to form a Cu film. Then, the semiconductor package was peeled off from the adhesive layer by a needle pickup.

(Evaluation of dicing property)
In the production of the above semiconductor packages, 50 semiconductor packages after dicing were randomly selected. The selected semiconductor package was observed with an optical microscope to observe the presence or absence of peeling at the end, and the dicing peeling was evaluated according to the following criteria.
S: Of the 50 samples, no sample was peeled by 300 μm or more A: Of the 50 samples, the number of samples peeled by 300 μm or more was less than 5% B: Of the 50 samples, 300 μm or more The number of peeled samples was 5% or more and less than 10% C: Of the 50 samples, the number of samples peeled by 300 μm or more was 10% or more.

(Evaluation of pick-up property)
Of the 100 semiconductor packages obtained in the production of the above semiconductor packages, the number of semiconductor packages in which pickup failure occurred was measured, and the pick-up property was evaluated according to the following criteria.
S: There is no package with a defective pickup A: There are 1 or 2 packages with a defective pickup B: There are 3 to 10 packages with a defective pickup C: 11 packages with a defective pickup ~ 30 D: There are 31 or more packages with defective pickup.

(Evaluation of pollution)
In the manufacture of the above semiconductor package, the semiconductor package after needle pickup was observed, and the contamination property was evaluated according to the following criteria.
S: No residue from the tape is found on the semiconductor package.
A: Residues from tape can be seen on semiconductor packages (less than 1% of the total) by observation with a microscope, etc. B: Residues from tape can be seen visually on some semiconductor packages (less than 1% of the total) C: Visually Residues from tape are seen in semiconductor packages of 1% or more and less than 90% D: Residues from tape are seen in semiconductor packages of 90% or more visually.

According to the present invention, it is possible to provide an adhesive tape having both adhesiveness capable of sufficiently fixing an adherend and light peelability.

Claims (6)

An adhesive tape having an adhesive layer containing a silicone compound.
After irradiating the surface of the pressure-sensitive adhesive layer with ultraviolet rays of 405 nm so that the amount of irradiation on the surface of the pressure-sensitive adhesive layer is 2500 mJ / cm ² , TOF-SIMS is used to make the Si ion intensity ratio of the surface of the pressure-sensitive adhesive layer 0 (Si ions). Measure strength / total ionic strength)
Next, after sputtering the surface portion of the pressure-sensitive adhesive layer having a Si ion intensity ratio of 0 once, the Si ion intensity ratio of 1 was measured using TOF-SIMS.
Next, when the sputtering and measurement steps were performed n times to obtain a Si ion intensity ratio of 0 to n,
Adhesive, in which the ratio (A / B) of the average value (A) of the Si ion intensity ratio 1 to 5 and the average value (B) of the Si ion intensity ratio 20 to 25 is 1.1 or more and 3.0 or less. tape. The adhesive tape according to claim 1, wherein the average value of the Si ion intensity ratios 1 to 5 is 0.001 or more and 0.03 or less. Claim that the base material has a base material, and the base material has a flexural rigidity of 2.38 × ^10-7 N ・ m ² or more in the TD direction at 23 ° C. and 2.98 × 10 ^-5 N ・ m ² or less. The adhesive tape according to 1 or 2. The adhesive tape according to claim 1, 2 or 3, wherein the gel content of the pressure-sensitive adhesive layer is 44% or more and 67% or less. The pressure-sensitive adhesive tape according to claim 1, 2, 3 or 4, wherein the content of the silicone compound is 1 part by weight or more and 40 parts by weight or less with respect to 100 parts by weight of the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer. The adhesive tape according to claim 1, 2, 3, 4 or 5, which is used for manufacturing a semiconductor.