Adhesive sheet

Abstract

Provided is an adhesive sheet that can effectively temporarily secure and reliably remove small electronic components (e.g., chips 100 μm or smaller). The adhesive sheet comprises a gas-generating layer and at least one adhesive layer disposed on one side of the gas-generating layer, wherein the adhesive layer is deformed by laser irradiation. In one embodiment, the gas-generating layer is a layer that absorbs ultraviolet light.

Description

Technical Field

[0001] The present invention relates to an adhesive sheet. Background Art

[0002] In the past, when electronic component was handled (processing), sometimes performed as follows: processed object was temporarily fixed on the adhesive sheet when processing, after processing, processed object was peeled off from this adhesive sheet.As the adhesive sheet used in such operation, sometimes use the adhesive sheet that has the adhesive force of regulation when processing, after processing, adhesive force can descend.As one of such adhesive sheet, proposed to make in the adhesive layer contain the adhesive sheet (for example patent documentation 1) that heat-expandable microspheres are constituted.The adhesive sheet that contains heat-expandable microspheres has following features: have the adhesive force of regulation, and by utilizing heating, heat-expandable microspheres are expanded, on the bonding surface, form concavo-convex and the contact area is reduced, and adhesive force descends or disappears thus.Such adhesive sheet has the advantage that no external stress just can easily peel off processed object.

[0003] Yet, in recent years, along with the tendency that the lightening of various devices, the number of carrying increases, and promote the miniaturization of electronic components, produced the necessity that the electronic components that will be miniaturized to the size of the same degree as above-mentioned heat-expandable microspheres are temporarily fixed.When miniaturized electronic components are temporarily fixed and processed, due to particle size deviation, the influence of the position of the heat-expandable microspheres that there is the large heat-expandable microspheres of particle diameter, the position that does not have heat-expandable microspheres etc. becomes large, and there is the situation that can't carry out good peeling at this position.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 2001-131507 Summary of the Invention

[0007] Problems to be solved by the invention

[0008] The present invention has been made to solve the above-mentioned conventional problems, and an object of the present invention is to provide a pressure-sensitive adhesive sheet that can satisfactorily temporarily fix small electronic components (for example, chips having a size of 100 μm or less) and can satisfactorily be peeled off.

[0009] Solutions for solving problems

[0010] The pressure-sensitive adhesive sheet of the present invention comprises a gas generating layer and at least one pressure-sensitive adhesive layer disposed on one side of the gas generating layer, wherein the pressure-sensitive adhesive layer is a layer whose surface is deformed by laser irradiation of the pressure-sensitive adhesive sheet.

[0011] In one embodiment, the gas generation layer is a layer capable of absorbing ultraviolet rays.

[0012] In one embodiment, the gas generation layer contains an ultraviolet absorber.

[0013] In one embodiment, the gas generation layer has a thickness of 0.1 μm to 50 μm.

[0014] In one embodiment, the gas generating layer is a layer that generates hydrocarbon-based gas.

[0015] In one embodiment, the gas generation layer has a gasification starting temperature of 150°C to 500°C.

[0016] In one embodiment, the elastic modulus Er(gas) [unit: MPa] and the thickness h(gas) [unit: μm] of the gas generation layer obtained by nanoindentation satisfy the following formula (1).

[0017] Log(Er(gas)×10 6 )≥8.01×h(gas) -0.116 ···(1)

[0018] In one embodiment, the adhesive layer has a thickness of 0.1 μm to 50 μm.

[0019] In one embodiment, the amount of deformation of the surface of the pressure-sensitive adhesive layer caused by laser irradiation of the pressure-sensitive adhesive sheet is 0.6 μm or more in terms of vertical displacement of the pressure-sensitive adhesive layer.

[0020] In one embodiment, the pressure-sensitive adhesive sheet has an ultraviolet transmittance of 30% or less at a wavelength of 360 nm.

[0021] In one embodiment, the pressure-sensitive adhesive sheet has a 10% weight loss temperature of 200°C to 500°C.

[0022] In one embodiment, the water vapor permeability of the adhesive sheet is 5000 g / (m 2 ·day) or less.

[0023] According to another aspect of the present invention, there is provided a method for processing an electronic component, comprising: attaching the electronic component to the adhesive sheet; and irradiating the adhesive sheet with laser light to peel the electronic component from the adhesive sheet.

[0024] In one embodiment, the electronic component is peeled off at selected locations.

[0025] In one embodiment, the method includes subjecting the electronic component to a predetermined treatment after attaching the electronic component to the pressure-sensitive adhesive sheet and before peeling the electronic component from the pressure-sensitive adhesive sheet.

[0026] In one embodiment, the processing is grinding, dicing, chip bonding, wire bonding, etching, evaporation, molding, circuit formation, inspection, product testing, cleaning, transfer, alignment, repair, or protection of the device surface.

[0027] In one embodiment, the method for handling the electronic component includes: peeling the electronic component from the pressure-sensitive adhesive sheet and then placing the electronic component on another sheet.

[0028] Effects of the Invention

[0029] According to the present invention, a pressure-sensitive adhesive sheet can be provided that can satisfactorily temporarily fix small electronic components (for example, chips having a size of 100 μm or less) and can satisfactorily be peeled off. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a schematic cross-sectional view of a pressure-sensitive adhesive sheet according to one embodiment of the present invention.

[0031] Figure 2 This is a schematic cross-sectional view of a pressure-sensitive adhesive sheet according to another embodiment of the present invention.

[0032] Figure 3 Schematic diagram illustrating the method for measuring puncture strength. DETAILED DESCRIPTION

[0033] A. Overview of PSA Sheet

[0034] Figure 1 Schematic cross-sectional view of an adhesive sheet according to a preferred embodiment of the present invention. The adhesive sheet 100 comprises a gas generating layer 10 and at least one adhesive layer 20 disposed on one side of the gas generating layer 10. The gas generating layer 10 generates gas by laser irradiation. More specifically, the gas generating layer 10 is a layer in which components are gasified by laser irradiation to generate gas. The surface of the adhesive layer 20 can be deformed by irradiating the adhesive sheet (substantially the gas generating layer) with laser. In one embodiment, the deformation can be generated on the side of the adhesive layer 20 opposite to the gas generating layer 10 due to the gas generated from the gas generating layer 10. As the laser, a UV laser is typically used.

[0035] The adhesive sheet of the present invention can be used by attaching a processed object such as an electronic component to an adhesive layer. The adhesive sheet of the present invention is provided with a gas generating layer, and gas is generated locally in a small range by laser irradiation. As described above, the adhesive layer is deformed due to the generation of the gas, and as a result, peelability is exhibited in the portion irradiated by the laser. Typically, the laser is irradiated from the side of the gas generating layer opposite to the adhesive layer. According to the present invention, since the above operation can produce deformation in a small range, the small electronic component can be well peeled even when extremely fine small electronic components are processed (processed). In addition, even in the case where a small electronic component to be peeled is temporarily fixed adjacent to a small electronic component that does not need to be peeled, peeling can be performed at the portion to be peeled, and peeling is not performed at the portion outside the peeling object, that is, only the small electronic component to be peeled can be peeled, and unnecessary detachment of the small electronic component can also be prevented. In order to deform the adhesive layer well, it is preferred to block at least a portion of the gas generated in a manner that does not escape from the adhesive sheet, and the adhesive layer can act as a gas barrier layer. Furthermore, the adhesive sheet exhibits excellent directivity during peeling, allowing for peeling only at the desired location, which is advantageous in terms of preventing breakage and minimizing adhesive residue. It should be noted that directivity during peeling refers to the positional accuracy of an adherend, such as a small electronic component, when peeled from the adhesive sheet and ejected at a predetermined distance. Excellent directivity prevents the adherend from flying in unintended directions during peeling.

[0036] The so-called deformation of the adhesive layer refers to the displacement generated in the normal direction (thickness direction) and the horizontal direction (direction orthogonal to the thickness direction) of the adhesive layer. The deformation of the adhesive layer is generated, for example, by using a UV laser with a wavelength of 355nm and a beam diameter of about 20μmφ, performing pulse scanning at 0.80mW power and 40kHz frequency, thereby generating gas from the gas generating layer. Regarding the deformed shape, for example, for any one point scanned by the pulse, one minute after laser irradiation, observation is performed based on the measurement of a confocal laser microscope or a non-contact interference microscope (WYKO). Its shape can be foaming (convex), through-hole (concave-convex), or concave (concave), and these deformations can produce peeling properties. When the electronic component is to be effectively peeled off along the normal direction, it is preferred that the displacement change in the normal direction before and after laser irradiation is large, and the one forming a foaming shape is particularly suitable. The foaming (convex) is based on the surface of the adhesive sheet of the unirradiated portion, and the highest point is defined as the vertical displacement Y, and the full width at half maximum is defined as the horizontal displacement X (diameter). Regarding the through holes (convex and concave) and depressions (concave) formed after laser irradiation, the difference between the highest point and the lowest point is defined as the vertical displacement Y, and the diameter of the hole is defined as the horizontal displacement X. Hereinafter, the portion deformed by laser irradiation will also be referred to as the "deformed portion". The vertical displacement of the adhesive layer is preferably 0.6 μm or more, more preferably 0.7 μm or more, and further preferably 1.0 μm or more. If it is within such a range, the peelability is excellent and the directionality during peeling is excellent. In addition, it can be peeled off with good precision along the desired direction, and as a result, residual glue, breakage, etc. can be prevented. The upper limit of the vertical displacement is, for example, 10 μm (preferably 20 μm). The horizontal displacement of the adhesive layer is preferably 80 μm or less, more preferably 50 μm or less, and further preferably 40 μm or less. If it is within such a range, for smaller adherends, it is preferred to peel only the desired portion. In addition, the same effect can be expected when the adherends are arranged at narrower intervals. The lower limit of the horizontal displacement is, for example, 3 μm (preferably 4 μm).

[0037] Figure 2 Schematic cross-sectional view of an adhesive sheet according to another embodiment of the present invention. The adhesive sheet 200 further comprises an intermediate layer 30 between the gas generating layer 10 and the adhesive layer 20. By providing the intermediate layer, the deformation of the adhesive layer can be easily controlled (described in detail later). In addition, the intermediate layer can cooperate with the adhesive layer to act as a gas barrier layer. Therefore, by providing the intermediate layer, the gas barrier properties are improved, and an adhesive sheet in which the adhesive layer is more preferably deformed can be obtained. The intermediate layer can be a single layer or a multilayer.

[0038] Although not shown, the adhesive sheet may further include other layers. For example, a substrate or another adhesive layer may be provided on the side of the gas generating layer opposite to the adhesive layer. The substrate may be, for example, a film formed from any suitable resin.

[0039] The adhesive layer of the adhesive sheet of the present invention preferably has an adhesive force of 0.1N / 20mm or more relative to SUS430, more preferably 0.2N / 20mm to 50N / 20mm, further preferably 0.5N / 20mm to 40N / 20mm, particularly preferably 0.7N / 20mm to 20N / 20mm, and most preferably 1N / 20mm to 10N / 20mm. If it is within such a range, an adhesive sheet that exhibits good adhesiveness as a temporary fixing sheet used in the manufacture of electronic components can be obtained. In this specification, the so-called adhesive force refers to the adhesive force measured by the method according to JIS Z 0237:2000 (lamination conditions: 2 kg roller 1 round trip, tensile speed: 300mm / min, peeling angle 180°) under an environment of 23°C.

[0040] In one embodiment, the gas-generating layer has a predetermined adhesive strength. The gas-generating layer of the adhesive sheet of the present invention preferably has an adhesive strength of 0.1 N / 20 mm or greater to SUS430, more preferably 0.5 N / 20 mm to 50 N / 20 mm, even more preferably 1 N / 20 mm to 40 N / 20 mm, particularly preferably 1.5 N / 20 mm to 30 N / 20 mm, and most preferably 2 N / 20 mm to 20 N / 20 mm. Within this range, an adhesive sheet exhibiting excellent adhesive properties can be obtained, for example, as a temporary fixing sheet used in the manufacture of electronic components.

[0041] The thickness of the pressure-sensitive adhesive sheet of the present invention is preferably 2 μm to 200 μm, more preferably 3 μm to 150 μm, and even more preferably 5 μm to 120 μm.

[0042] The haze value of the adhesive sheet of the present invention is preferably 50% or less, more preferably 0.1% to 40%, and further preferably 0.5% to 30%. If it is within such a range, the adherend (for example, a table for temporarily fixing electronic components) can be visually identified across the adhesive sheet, thereby obtaining an adhesive sheet with excellent visual recognition of a mark provided on a fixing table, for example, to display the temporary fixing position of an electronic component. The adhesive sheet of the present invention can be constituted so that each layer of the adhesive sheet does not contain an insoluble filler, so that it can become an adhesive sheet with a small haze value and excellent visual recognition of the adherend as described above. Such an effect is an excellent effect that cannot be obtained by using an adhesive sheet containing an insoluble filler (for example, heat-expandable microspheres).

[0043] The water vapor permeability of the adhesive sheet of the present invention is preferably 5000 g / (m 2 ·day) or less, more preferably 4800g / (m 2 ·day) or less, more preferably 4500g / (m 2 ·day) or less, more preferably 4200g / (m 2 ·day) or less. An adhesive sheet having a water vapor permeability in such a range can prevent the escape of gas generated by laser irradiation and can form a deformed portion with an excellent shape in the adhesive layer. If such an adhesive sheet is used, small adherends (for example, electronic components) can be peeled off with good precision. The smaller the water vapor permeability of the adhesive sheet of the present invention, the more preferable it is, and its lower limit is, for example, 0.1 g / (m 2 The water vapor transmission rate can be measured in an atmosphere of 30° C. and 90% RH by a measurement method in accordance with JIS K7129B.

[0044] The water vapor permeability of the laminate comprising the adhesive layer and the intermediate layer is preferably 10000 g / (m 2 ·day) or less, more preferably 7000g / (m 2 ·day) or less, more preferably 5000g / (m 2 ·day) or less, more preferably 4800g / (m 2 ·day) or less, more preferably 4500g / (m 2 ·day) or less, particularly preferably 4200g / (m 2 ·day) or less. When it is within such a range, the laminate comprising the adhesive layer and the intermediate layer functions well as a gas barrier layer, and a deformed portion of excellent shape is formed in the adhesive layer. If such an adhesive sheet is used, small adherends (such as electronic components) can be peeled off with good precision. The smaller the water vapor permeability of the laminate comprising the adhesive layer and the intermediate layer, the more preferable it is, and its lower limit is, for example, 1 g / (m 2 ·day).

[0045] The puncture strength of the laminate comprising the above-mentioned adhesive layer and the intermediate layer is preferably 10mN to 5000mN, more preferably 30mN to 4000mN, further preferably 50mN to 3000mN, and particularly preferably 100mN to 2000mN. Within such a range, the laminate comprising the adhesive layer and the intermediate layer functions well as a gas barrier layer, and satisfactorily produces shape changes based on gas generation, resulting in a deformed portion of excellent shape formed in the adhesive layer. If such an adhesive sheet is used, small adherends (such as electronic components) can be peeled off with good precision. Puncture strength such as Figure 3As shown, a compression tester 6 (manufactured by Kato Tech, trade name "KES-G5") is used to measure the strength of a sample 4 (e.g., a laminate) by clamping it between sample holders 5A and 5B having a circular opening with a diameter of 11.28 mm. More specifically, a puncture needle (curvature radius: 1 mm) is inserted into the sample at the center of the circular opening at a measurement temperature of 23°C (puncture speed: 0.1 mm / s), and the maximum load at the rupture point is determined as the puncture strength.

[0046] The ultraviolet transmittance of the laminate including the pressure-sensitive adhesive layer and the intermediate layer at a wavelength of 360 nm is preferably 50% to 100%, more preferably 60% to 95%.

[0047] The UV transmittance of the adhesive sheet at a wavelength of 360 nm is preferably 30% or less, more preferably 20% or less, even more preferably 15% or less, particularly preferably 10% or less, and most preferably 5% or less. The lower limit of the UV transmittance of the adhesive sheet at a wavelength of 360 nm is, for example, 0% (preferably 0.05%, more preferably 0.1%).

[0048] The 10% weight loss temperature of the adhesive sheet is preferably 200°C to 500°C, more preferably 220°C to 450°C, even more preferably 250°C to 400°C, and particularly preferably 270°C to 370°C. Within this range, an adhesive sheet capable of forming a more favorable deformable portion upon laser irradiation can be obtained. The 10% weight loss temperature of the adhesive sheet refers to the temperature at which, in a TGA analysis of the adhesive sheet when heated, the sheet has decreased by 10% by weight relative to its pre-heating weight (i.e., the weight of the adhesive sheet is 90% of its pre-irradiation weight).

[0049] B. Gas generation layer

[0050] The gas generation layer may be a layer that can absorb ultraviolet rays. In one embodiment, the gas generation layer contains an ultraviolet absorber. By containing an ultraviolet absorber, a gas generation layer that can absorb laser light and gasify can be formed. Typically, the gas generation layer contains an ultraviolet absorber and an adhesive A. Preferably, the ultraviolet absorber is dissolved in the adhesive A and exists. If the ultraviolet absorber is dissolved in the adhesive A and exists, the following adhesive sheet can be obtained: a deformed portion (such as a concave-convex portion) can be generated at any part of the adhesive layer, and the shape deviation of the deformed portion (such as a concave-convex portion) is small. If such an adhesive sheet is used, a deformed portion (such as a concave-convex portion) can be generated with good precision at the desired position, and the effect of the present invention becomes significant. It should be noted that, in this specification, the so-called "dissolved in the adhesive and exists" means that the ultraviolet absorber does not exist in the gas generation layer in the form of particles. More specifically, it is preferred that the gas generation layer does not contain an ultraviolet absorber with a particle size of 10 μm or more in the particle distribution measurement in the cross section of the gas generation layer based on X-ray CT. It should be noted that the gas generation layer may contain a component that is insoluble in the adhesive, or it may not contain it. In one embodiment, the presence and content of insoluble components in the gas generation layer are evaluated by the haze value of the gas generation layer. A lower haze value indicates a lower content of insoluble components in the gas generation layer. Preferably, the gas generation layer contains substantially no components insoluble in the binder.

[0051] The elastic modulus of the cross section of the gas generation layer obtained by nanoindentation is preferably 0.01MPa to 1000MPa, more preferably 0.05MPa to 800MPa. When it is within such a range, the shape change of the gas generation layer based on gas generation occurs satisfactorily, and as a result, a deformed portion of excellent shape is formed in the adhesive layer. The so-called elastic modulus obtained by nanoindentation refers to the elastic modulus obtained by continuously measuring the load and the indentation depth of the indenter when the indenter is pressed into the sample (for example, the adhesive surface) from the time of loading to the time of unloading, and the load-indentation depth curve obtained. The elastic modulus obtained by nanoindentation is obtained as follows: the displacement-load hysteresis curve obtained by pressing a diamond Berkovich-type (triangular pyramid-type) probe vertically on the cut cross section of the measurement object layer is numerically processed using the software (triboscan) included with the measuring device, thereby obtaining it. In this specification, the elastic modulus of the cross section obtained by the nanoindentation method is the elastic modulus measured by a single indentation method at a specified temperature (25°C) using a nanoindenter (Triboindenter TI-950 manufactured by Hysitron Inc.) under the measurement conditions of an indentation speed of about 500 nm / sec, a withdrawal speed of about 500 nm / sec, and an indentation depth of about 1500 nm. It should be noted that the elastic modulus of the gas generation layer can be adjusted by the type of material contained in the layer, the structure of the base polymer constituting the material, the type and amount of additives added to the layer, etc. It should be noted that in this specification, when the cross section or surface is not described and only the elastic modulus obtained by the nanoindentation method is recorded, the elastic modulus refers to the elastic modulus of the cross section obtained by the nanoindentation method.

[0052] The elastic modulus obtained by nanoindentation on the surface of the gas generation layer is preferably 0.01MPa to 1000MPa, more preferably 0.05MPa to 800MPa. If it is within such a range, the shape change of the gas generation layer based on gas generation occurs satisfactorily, and as a result, a deformation portion of excellent shape is formed in the adhesive layer. The so-called elastic modulus obtained by nanoindentation refers to the elastic modulus obtained by continuously measuring the load and the indentation depth of the indenter when the indenter is pressed into the sample (for example, the adhesive surface) from the time of loading until unloading, and the load-indentation depth curve obtained. The elastic modulus obtained by nanoindentation is obtained as follows: for the displacement-load hysteresis curve obtained by pressing a diamond-made Berkovich-type (triangular pyramid-type) probe vertically onto the measurement object layer, the software (triboscan) included with the measuring device is used for numerical processing, thereby obtaining. In this specification, the elastic modulus of the surface obtained by the nanoindentation method is the elastic modulus measured by a single indentation method at a specified temperature (25°C) using a nanoindenter (Triboindenter TI-950 manufactured by Hysitron Inc.) under the measurement conditions of an indentation speed of about 500 nm / sec, a withdrawal speed of about 500 nm / sec, and an indentation depth of about 3000 nm. It should be noted that the elastic modulus of the gas generation layer can be adjusted by the type of material contained in the layer, the structure of the base polymer constituting the material, the type and amount of additives added to the layer, etc. In the present invention, there is no significant difference between the elastic modulus obtained by the nanoindentation method measured by the above method using the cross section as the measurement surface and the elastic modulus obtained by the nanoindentation method measured by the above method using the surface as the measurement surface. In the case where it is difficult to measure from the cross section, the value measured from the surface can be used as the measurement value from the cross section.

[0053] The gasification starting temperature of the gas generation layer is preferably 150°C to 500°C, more preferably 170°C to 450°C, further preferably 190°C to 420°C, and particularly preferably 200°C to 400°C. If it is within this range, a pressure-sensitive adhesive sheet that can form a better deformation portion by laser irradiation can be obtained. It should be noted that, in this specification, the so-called gasification starting temperature of the gas generation layer refers to the gas generation starting temperature calculated based on EGA analysis when the pressure-sensitive adhesive sheet is heated. The gas generation starting temperature is defined by the temperature at which the half-value of the maximum gas generation peak of the EGA / MS spectrum obtained by EGA analysis is reached. The lower the gasification starting temperature, the lower the temperature at which gas generation starts during laser irradiation, and a sufficient amount of gas is generated even when laser irradiation is performed at a lower power. In one embodiment, the gasification starting temperature of the gas generation layer is equivalent to the gasification starting temperature of the ultraviolet absorber.

[0054] The 10% weight loss temperature of the gas generation layer is preferably 150°C to 500°C, more preferably 170°C to 450°C, and even more preferably 200°C to 400°C. Within this range, a PSA sheet capable of forming a more favorable deformation portion upon laser irradiation can be obtained. The 10% weight loss temperature of the gas generation layer refers to the temperature at which, when the PSA sheet is heated (e.g., heated by laser irradiation), the weight of the gas generation layer decreases by 10% by weight relative to its pre-heating weight (i.e., the weight of the gas generation layer reaches 90% of its pre-heating weight) as measured by TGA analysis.

[0055] The thickness of the gas generation layer is preferably 0.1 μm to 50 μm, more preferably 1 μm to 40 μm, further preferably 2 μm to 30 μm, and particularly preferably 5 μm to 20 μm. Within these ranges, a PSA sheet capable of forming a better deformable portion by laser irradiation can be obtained.

[0056] The elastic modulus Er(gas) [unit: MPa] and the thickness h(gas) [unit: μm] of the gas generation layer obtained by nanoindentation satisfy the following formula (1).

[0057] Log(Er(gas)×10 6 )≥8.01×h(gas) -0.116 ···(1)

[0058] In the present invention, by configuring the gas-generating layer to satisfy the above-mentioned formula (1), excessive deformation caused by gas generated from the gas-generating layer can be prevented, and the adhesive sheet can be deformed well by laser irradiation. By forming such a gas-generating layer, even a small surface deformation can be generated without providing a thick barrier layer (adhesive layer) as a layer to prevent excessive deformation, and a flexible adhesive layer (gas barrier layer) can be configured.

[0059] In one embodiment, the elastic modulus Er(gas) [unit: MPa] obtained by nanoindentation and the thickness h(gas) [unit: μm] satisfy the following formula (2). In one embodiment, the elastic modulus Er(gas) [unit: MPa] obtained by nanoindentation and the thickness h(gas) [unit: μm] satisfy the following formula (3).

[0060] Log(Er(gas)×10 6 )≥7.66×h(gas) -0.092 ···(2)

[0061] Log(Er(gas)×10 6 )≥7.52×h(gas) -0.081 ···(3)

[0062] Within such a range, the above-mentioned effects become more significant.

[0063] In one embodiment, the elastic modulus Er(gas) [unit: MPa] and the thickness h(gas) [unit: μm] obtained by the nanoindentation method further satisfy the following formula (4).

[0064] Log(Er(gas)×10 6 )≤47.675×h(gas) -0.519 ···(4)

[0065] The gas generation layer preferably has an ultraviolet light transmittance of 360 nm or less, more preferably 20% or less, even more preferably 15% or less, particularly preferably 10% or less, and most preferably 5% or less. The lower limit of the ultraviolet light transmittance of the gas generation layer at 360 nm is, for example, 0% (preferably 0.05%, more preferably 0.1%).

[0066] The haze value of the gas generation layer is preferably 55% or less, more preferably 0.1% to 50%, and even more preferably 0.5% to 40%.

[0067] B-1. Ultraviolet absorber

[0068] As the above-mentioned ultraviolet absorber, any appropriate ultraviolet absorber can be used as long as the effect of the present invention is obtained. As ultraviolet absorbers, for example, benzotriazole ultraviolet absorbers, benzophenone ultraviolet absorbers, triazine ultraviolet absorbers, salicylate ultraviolet absorbers, cyanoacrylate ultraviolet absorbers, etc. can be mentioned. Among them, triazine ultraviolet absorbers or benzotriazole ultraviolet absorbers are preferred, and triazine ultraviolet absorbers are particularly preferred. In particular, when an acrylic adhesive is used as the adhesive A, triazine ultraviolet absorbers can be preferably used due to their high compatibility with the base polymer of the acrylic adhesive. Triazine ultraviolet absorbers are more preferably composed of compounds having a hydroxyl group, and ultraviolet absorbers composed of hydroxyphenyltriazine compounds (hydroxyphenyltriazine ultraviolet absorbers) are particularly preferred.

[0069] Examples of hydroxyphenyltriazine-based ultraviolet absorbers include the reaction product of 2-(4,6-bis(2,4-dimethylphenyl)-1,3,5-triazin-2-yl)-5-hydroxyphenyl and [(C10-C16 (mainly C12-C13) alkoxy)methyl]oxirane (trade name "TINUVIN 400", manufactured by BASF), 2-[4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine-2-yl]-5-[3-(dodecyloxy)-2-hydroxypropoxy]phenol, reaction product of 2-(2,4-dihydroxyphenyl)-4,6-bis-(2,4-dimethylphenyl)-1,3,5-triazine and glycidic acid (2-ethylhexyl) ester (trade name "TINUVIN 405", manufactured by BASF), 2,4-bis(2-hydroxy-4-butoxyphenyl)-6-(2,4-dibutoxyphenyl)-1,3,5-triazine (trade name "TINUVIN 460", manufactured by BASF), 2-(4,6-diphenyl-1,3,5-triazine-2-yl)-5-[(hexyl)oxy]phenol (trade name "TINUVIN 1577", manufactured by BASF), 2-(4,6-diphenyl-1,3,5-triazine-2-yl)-5-[2-(2-ethylhexanoyloxy)ethoxy]phenol (trade name "Adekastab LA-46", manufactured by ADEKA), 2-(2-hydroxy-4-[1-octyloxycarbonylethoxy]phenyl)-4,6-bis(4-phenylphenyl)-1,3,5-triazine (trade name "TINUVIN 479", manufactured by BASF), and trade name "TINUVIN 477" manufactured by BASF.

[0070] Examples of the benzotriazole-based ultraviolet absorber (benzotriazole-based compound) include 2-(2-hydroxy-5-tert-butylphenyl)-2H-benzotriazole (trade name "TINUVIN PS", manufactured by BASF), an ester compound of phenylpropionic acid and 3-(2H-benzotriazol-2-yl)-5-(1,1-dimethylethyl)-4-hydroxy (C7-9 side chain and linear alkyl) (trade name "TINUVIN 384-2", manufactured by BASF), a mixture of octyl 3-[3-tert-butyl-4-hydroxy-5-(5-chloro-2H-benzotriazol-2-yl)phenyl]propionate and 2-ethylhexyl 3-[3-tert-butyl-4-hydroxy-5-(5-chloro-2H-benzotriazol-2-yl)phenyl]propionate (trade name "TINUVIN 109", manufactured by BASF), 2-(2H-benzotriazol-2-yl)-4,6-bis(1-methyl-1-phenylethyl)phenol (trade name "TINUVIN 900", manufactured by BASF), 2-(2H-benzotriazol-2-yl)-6-(1-methyl-1-phenylethyl)-4-(1,1,3,3-tetramethylbutyl)phenol (trade name "TINUVIN 928", manufactured by BASF), methyl 3-(3-(2H-benzotriazol-2-yl)-5-tert-butyl-4-hydroxyphenyl)propionate / polyethylene glycol 300 reaction product (trade name "TINUVIN 1130", manufactured by BASF), 2-(2H-benzotriazol-2-yl)-4,6-bis(1-methyl-1-phenylethyl)phenol (trade name "TINUVIN 234", manufactured by BASF), 2-[5-chloro-2H-benzotriazol-2-yl]-4-methyl-6-(tert-butyl)phenol (trade name "TINUVIN 326", manufactured by BASF), 2-(2H-benzotriazol-2-yl)-4,6-di-tert-amylphenol (trade name "TINUVIN 328", manufactured by BASF), 2-(2H-benzotriazol-2-yl)-4-(1,1,3,3-tetramethylbutyl)phenol (trade name "TINUVIN 329", manufactured by BASF), 2,2'-methylenebis[6-(2H-benzotriazole-2-yl)-4-(1,1,3,3-(3-(2H-benzotriazol-2-yl)-5-tert-butyl-4-hydroxyphenyl)propionic acid methyl ester and polyethylene glycol 300 reaction product (trade name "TINUVIN 213", manufactured by BASF), 2-(2H-benzotriazol-2-yl)-6-dodecyl-4-methylphenol (trade name "TINUVIN 571", manufactured by BASF), 2-[2-hydroxy-3-(3,4,5,6-tetrahydrophthalimide-methyl)-5-methylphenyl]benzotriazole (trade name "Sumisorb 250", manufactured by Sumitomo Chemical Co., Ltd.), 2-(3-tert-butyl-2-hydroxy-5-methylphenyl)-5-chloro-2H-benzotriazole (trade name "SEESORB 703", manufactured by Shipro Kasei Co., Ltd.), 2-(2H-benzotriazol-2-yl)-4-methyl-6-(3,4,5,6-tetrahydrophthalimidomethyl)phenol (trade name "SEESORB 706", manufactured by Shipro Kasei Co., Ltd.), 2-(4-benzoyloxy-2-hydroxyphenyl)-5-chloro-2H-benzotriazole (trade name "SEESORB 7012BA" manufactured by Shipro Kasei Co., Ltd.), 2-tert-butyl-6-(5-chloro-2H-benzotriazol-2-yl)-4-methylphenol (trade name "KEMISORB 73", manufactured by Chemipro Kasei Co., Ltd.), 2,2'-methylenebis[6-(2H-benzotriazol-2-yl)-4-tert-octylphenol] (trade name "Adekastab LA-31", manufactured by ADEKA Corporation), 2-(2H-benzotriazol-2-yl) para-cellulose (trade name "Adekastab LA-32", manufactured by ADEKA Corporation), 2-(5-chloro-2H-benzotriazol-2-yl)-6-tert-butyl-4-methylphenol (trade name "Adekastab LA-36", manufactured by ADEKA Corporation), etc.

[0071] The molecular weight of the compound constituting the ultraviolet absorber is preferably 200 to 1500, more preferably 250 to 1200, and even more preferably 300 to 1000. Within these ranges, a pressure-sensitive adhesive sheet capable of forming a more favorable deformation portion by laser irradiation can be obtained.

[0072] The maximum absorption wavelength of the ultraviolet absorber is preferably 300 nm to 450 nm, more preferably 320 nm to 400 nm, and even more preferably 330 nm to 380 nm.

[0073] The content of the ultraviolet absorber is preferably 1 to 100 parts by weight, more preferably 1 to 50 parts by weight, and even more preferably 5 to 30 parts by weight, relative to 100 parts by weight of the gas generation layer. Within this range, a pressure-sensitive adhesive sheet capable of forming a more favorable deformation portion upon laser irradiation can be obtained.

[0074] B-2. Adhesive A

[0075] As the adhesive A contained in the gas generating layer, a pressure-sensitive adhesive A is preferably used. Examples of the adhesive A include acrylic adhesives, rubber adhesives, vinyl alkyl ether adhesives, silicone adhesives, polyester adhesives, polyamide adhesives, urethane adhesives, and styrene-diene block copolymer adhesives. Among these, acrylic adhesives or rubber adhesives are preferred, and acrylic adhesives are more preferred. It should be noted that the above adhesives may be used alone or in combination of two or more.

[0076] Examples of the acrylic pressure-sensitive adhesive include those containing, as a base polymer, an acrylic polymer (homopolymer or copolymer) using one or more kinds of (meth)acrylic acid alkyl esters as monomer components. Specific examples of the alkyl (meth)acrylate include C1-20 alkyl (meth)acrylates such as methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, sec-butyl (meth)acrylate, tert-butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, nonyl (meth)acrylate, isononyl (meth)acrylate, decyl (meth)acrylate, isodecyl (meth)acrylate, undecyl (meth)acrylate, dodecyl (meth)acrylate, tridecyl (meth)acrylate, tetradecyl (meth)acrylate, pentadecyl (meth)acrylate, hexadecyl (meth)acrylate, heptadecyl (meth)acrylate, octadecyl (meth)acrylate, nonadecyl (meth)acrylate, and eicosyl (meth)acrylate. Among them, alkyl (meth)acrylates having a linear or branched alkyl group having 4 to 18 carbon atoms can be preferably used.

[0077] The acrylic polymer may contain units corresponding to other monomer components copolymerizable with the alkyl (meth)acrylate, as required, for the purpose of modifying cohesion, heat resistance, crosslinking properties, etc. Examples of such monomer components include: carboxyl group-containing monomers such as acrylic acid, methacrylic acid, carboxyethyl acrylate, carboxypentyl acrylate, itaconic acid, maleic acid, fumaric acid, and crotonic acid; acid anhydride monomers such as maleic anhydride and itaconic anhydride; hydroxyl group-containing monomers such as hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, hydroxyhexyl (meth)acrylate, hydroxyoctyl (meth)acrylate, hydroxydecyl (meth)acrylate, hydroxylauryl (meth)acrylate, and (4-hydroxymethylcyclohexyl)methyl methacrylate; styrenesulfonic acid, allylsulfonic acid, 2-(meth)acrylamido-2-methylpropanesulfonic acid, and (meth)acrylamidopropanesulfonic acid. , (meth)acrylate sulfopropyl, (meth)acryloyloxynaphthalenesulfonic acid and other sulfonic acid group-containing monomers; (meth)acrylamide, N,N-dimethyl (meth)acrylamide, N-butyl (meth)acrylamide, N-hydroxymethyl (meth)acrylamide, N-hydroxymethylpropane (meth)acrylamide and other (N-substituted) amide monomers; (meth)acrylate aminoalkyl ester monomers such as (meth)acrylate aminoethyl, (meth)acrylate N,N-dimethylaminoethyl, (meth)acrylate, tert-butylaminoethyl (meth)acrylate; (meth)acrylate alkoxyalkyl ester monomers such as (meth)acrylate methoxyethyl, (meth)acrylate ethoxyethyl; N-cyclohexyl acrylate Maleimide monomers such as imide, N-isopropylmaleimide, N-laurylmaleimide, and N-phenylmaleimide; itaconimide monomers such as N-methylitaconimide, N-ethylitaconimide, N-butylitaconimide, N-octylitaconimide, N-2-ethylhexylitaconimide, N-cyclohexylitaconimide, and N-laurylitaconimide; succinimide monomers such as N-(meth)acryloyloxymethylenesuccinimide, N-(meth)acryloyl-6-oxyhexamethylenesuccinimide, and N-(meth)acryloyl-8-oxyoctamethylenesuccinimide; vinyl acetate, vinyl propionate, and N- Vinyl monomers such as vinyl pyrrolidone, methyl vinyl pyrrolidone, vinyl pyridine, vinyl piperidone, vinyl pyrimidine, vinyl piperazine, vinyl pyrazine, vinyl pyrrole, vinyl imidazole, vinyl oxazole, vinyl morpholine, N-vinyl carboxylic acid amides, styrene, α-methylstyrene, and N-vinyl caprolactam; cyanoacrylate monomers such as acrylonitrile and methacrylonitrile; epoxy group-containing acrylic monomers such as glycidyl (meth)acrylate; glycol acrylate monomers such as polyethylene glycol (meth)acrylate, polypropylene glycol (meth)acrylate, methoxyethylene glycol (meth)acrylate, and methoxypolypropylene glycol (meth)acrylate;Acrylate monomers having heterocyclic rings, halogen atoms, silicon atoms, etc., such as tetrahydrofurfuryl (meth)acrylate, fluoro(meth)acrylate, and silicone (meth)acrylate; polyfunctional monomers such as hexanediol di(meth)acrylate, (poly)ethylene glycol di(meth)acrylate, (poly)propylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, pentaerythritol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, epoxy acrylate, polyester acrylate, and urethane acrylate; olefin monomers such as isoprene, butadiene, and isobutylene; and vinyl ether monomers such as vinyl ether. These monomer components may be used alone or in combination of two or more.

[0078] Examples of the rubber-based adhesives include those using the following as base polymers: natural rubber; polyisoprene rubber, styrene-butadiene (SB) rubber, styrene-isoprene (SI) rubber, styrene-isoprene-styrene block copolymer (SIS) rubber, styrene-butadiene-styrene block copolymer (SBS) rubber, styrene-ethylene-butylene-styrene block copolymer (SEBS) rubber, styrene-ethylene-propylene-styrene block copolymer (SEPS) rubber, styrene-ethylene-propylene block copolymer (SEP) rubber, recycled rubber, butyl rubber, polyisobutylene, synthetic rubbers such as modified forms thereof, and the like.

[0079] The gas generated from the above-mentioned gas generation layer is preferably a hydrocarbon (preferably aliphatic hydrocarbon) gas. The gas generation layer that can generate hydrocarbon gas is composed of, for example, hydrocarbon compounds as the main component. The gas generation layer preferably does not contain halogen-containing compounds. If the generated gas is a hydrocarbon gas, corrosion of electronic components as the workpiece can be prevented. Such an effect is made more significant by forming a gas generation layer that does not contain halogen-containing compounds. The formula weight of the generated ions from the gas generation layer is preferably 10m / z to 800m / z, more preferably 11m / z to 700m / z, further preferably 12m / z to 500m / z, and particularly preferably 13m / z to 400m / z.

[0080] The adhesive A may contain any appropriate additives as needed. Examples of such additives include crosslinking agents, tackifiers (e.g., rosin-based tackifiers, terpene-based tackifiers, hydrocarbon-based tackifiers, etc.), plasticizers (e.g., trimellitate-based plasticizers, pyromellitate-based plasticizers), pigments, dyes, antioxidants, conductive materials, antistatic agents, light stabilizers, release modifiers, softeners, surfactants, flame retardants, and antioxidants.

[0081] Examples of the crosslinking agent include isocyanate crosslinking agents, epoxy crosslinking agents, melamine crosslinking agents, peroxide crosslinking agents, urea crosslinking agents, metal alkoxide crosslinking agents, metal chelate crosslinking agents, metal salt crosslinking agents, carbodiimide crosslinking agents, oxazoline crosslinking agents, aziridine crosslinking agents, and amine crosslinking agents. Among them, an isocyanate crosslinking agent or an epoxy crosslinking agent is preferred.

[0082] Specific examples of the isocyanate crosslinking agent include lower aliphatic polyisocyanates such as butylene diisocyanate and hexamethylene diisocyanate; alicyclic isocyanates such as cyclopentylene diisocyanate, cyclohexylene diisocyanate, and isophorone diisocyanate; aromatic isocyanates such as 2,4-toluene diisocyanate, 4,4'-diphenylmethane diisocyanate, and xylylenediisocyanate; and isocyanate adducts such as trimethylolpropane / toluene diisocyanate trimer adduct (manufactured by Nippon Polyurethane Industry Co., Ltd., trade name "Coronate L"), trimethylolpropane / hexamethylene diisocyanate trimer adduct (manufactured by Nippon Polyurethane Industry Co., Ltd., trade name "Coronate HL"), and isocyanurate of hexamethylene diisocyanate (manufactured by Nippon Polyurethane Industry Co., Ltd., trade name "Coronate HX"). The content of the isocyanate crosslinking agent can be set to any appropriate amount depending on the desired adhesive strength, and is typically 0.1 to 20 parts by weight, more preferably 0.5 to 10 parts by weight, relative to 100 parts by weight of the base polymer.

[0083] Examples of the epoxy crosslinking agent include N,N,N',N'-tetraglycidyl-m-xylylenediamine, diglycidyl aniline, 1,3-bis(N,N-glycidylaminomethyl)cyclohexane (manufactured by Mitsubishi Gas Chemical Co., Ltd., trade name "Tetrad C"), 1,6-hexanediol diglycidyl ether (manufactured by Kyoeisha Chemical Co., Ltd., trade name "Epolight 1600"), neopentyl glycol diglycidyl ether (manufactured by Kyoeisha Chemical Co., Ltd., trade name "Epolight 1500NP"), ethylene glycol diglycidyl ether (manufactured by Kyoeisha Chemical Co., Ltd., trade name "Epolight 40E"), propylene glycol diglycidyl ether (manufactured by Kyoeisha Chemical Co., Ltd., trade name "Epolight 70P"), polyethylene glycol diglycidyl ether (manufactured by NOF Corporation, trade name "EPIOL E-400”), polypropylene glycol diglycidyl ether (manufactured by NOF Corporation, trade name “EPIOL P-200”), sorbitol polyglycidyl ether (manufactured by Nagase ChemteX, trade name “Denacol EX-611”), glycerol polyglycidyl ether (manufactured by Nagase ChemteX, trade name “Denacol EX-314”), pentaerythritol polyglycidyl ether, polyglycerol polyglycidyl ether (manufactured by Nagase ChemteX, trade name “Denacol EX-512”), sorbitan polyglycidyl ether, trimethylolpropane polyglycidyl ether, diglycidyl adipate, diglycidyl phthalate, triglycidyl tris(2-hydroxyethyl)isocyanurate, resorcinol diglycidyl ether, bisphenol-S-diglycidyl ether, epoxy resins having two or more epoxy groups in the molecule, and the like. The content of the epoxy crosslinking agent can be set to any appropriate amount depending on the desired adhesive strength, and is typically 0.01 to 10 parts by weight, more preferably 0.03 to 5 parts by weight, relative to 100 parts by weight of the base polymer.

[0084] C. Adhesive layer

[0085] The adhesive layer contains any appropriate adhesive B. The adhesive B may be a pressure-sensitive adhesive B1 or a curable adhesive B2.

[0086] The thickness of the adhesive layer is preferably 0.1 μm to 50 μm, more preferably 0.5 μm to 40 μm, further preferably 1 μm to 30 μm, and particularly preferably 2 μm to 20 μm. Within these ranges, an adhesive layer having a preferred adhesive strength and functioning well as a gas barrier layer can be formed.

[0087] The water vapor permeability of the adhesive layer is preferably 20000 g / (m 2·day) or less, more preferably 10000g / (m 2 ·day) or less, more preferably 7000g / (m 2 ·day) or less, more preferably 5000g / (m 2 ·day) or less, more preferably 4800g / (m 2 ·day) or less, particularly preferably 4500g / (m 2 ·day) or less. If it is within this range, the adhesive layer functions well as a gas barrier layer, forming a deformed portion with an excellent shape. If such an adhesive sheet is used, small adherends (for example, electronic components) can be peeled off with good precision. The smaller the water vapor permeability of the adhesive layer, the more preferable it is, and its lower limit is, for example, 100 g / (m 2 ·day).

[0088] The puncture strength of the adhesive layer is preferably 10mN to 3000mN, more preferably 30mN to 2500mN, further preferably 50mN to 2000mN, and particularly preferably 100mN to 2000mN. Within this range, the adhesive layer functions well as a gas barrier layer, and the shape change caused by gas generation occurs satisfactorily, resulting in a deformed portion with a well-defined shape. Using such an adhesive sheet allows for the precise removal of small adherends (e.g., electronic components).

[0089] The ultraviolet transmittance of the pressure-sensitive adhesive layer at a wavelength of 360 nm is preferably 50% to 100%, more preferably 60% to 95%.

[0090] C-1. Pressure-sensitive adhesive B1

[0091] Examples of the pressure-sensitive adhesive B1 include acrylic adhesives, rubber adhesives, vinyl alkyl ether adhesives, silicone adhesives, polyester adhesives, polyamide adhesives, urethane adhesives, and styrene-diene block copolymer adhesives. Among these, acrylic adhesives and rubber adhesives are preferred, with acrylic adhesives being more preferred. As the adhesive B1 contained in the pressure-sensitive adhesive-containing adhesive layer, the adhesives described in Section B-2 can be used.

[0092] C-2. Curing Adhesive B2

[0093] Examples of the curable adhesive B2 include thermosetting adhesives and active energy ray-curable adhesives. An active energy ray-curable adhesive is preferably used. The adhesive layer formed by the active energy ray-curable adhesive is formed by irradiation with active energy rays, that is, it is an adhesive layer that has a predetermined adhesive strength after irradiation with active energy rays.

[0094] Examples of the resin material constituting the active energy ray-curable adhesive include those described in Ultraviolet Curing System (authored by Kiyoshi Kato, published by the General Technology Center (1989)), Photocuring Technology (edited by the Technical Information Association (2000)), Japanese Patent Application Publication No. 2003-292916, and Japanese Patent No. 4151850. More specifically, examples include a resin material (B2-1) containing a polymer serving as a masterbatch and an active energy ray-reactive compound (monomer or oligomer), and a resin material (B2-2) containing an active energy ray-reactive polymer.

[0095] Examples of the polymer serving as the masterbatch include rubber-based polymers such as natural rubber, polyisobutylene rubber, styrene-butadiene rubber, styrene-isoprene-styrene block copolymer rubber, reclaimed rubber, butyl rubber, polyisobutylene rubber, and nitrile rubber (NBR); silicone-based polymers; and acrylic polymers. These polymers may be used alone or in combination of two or more.

[0096] As the above-mentioned active energy ray reactive compound, for example, a photoreactive monomer or oligomer containing a functional group having a carbon-carbon multiple bond such as a plurality of acryloyl groups, methacryloyl groups, vinyl groups, allyl groups, ethynyl groups, etc. is mentioned. Among them, it is preferred to use a compound having an ethylenically unsaturated functional group, and more preferably to use a (meth) acrylic acid compound having an ethylenically unsaturated functional group. The compound having an ethylenically unsaturated functional group easily generates free radicals by ultraviolet light, so if the compound is used, an adhesive layer that can be cured in a short time can be formed. In addition, if a (meth) acrylic acid compound having an ethylenically unsaturated functional group is used, an adhesive layer having a moderate hardness after curing can be formed. Specific examples of photoreactive monomers or oligomers include (meth)acryloyl group-containing compounds such as trimethylolpropane tri(meth)acrylate, tetramethylolmethane tetra(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol monohydroxypenta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, polyethylene glycol di(meth)acrylate, and urethane (meth)acrylate compounds; and dimers to pentamers of such (meth)acryloyl group-containing compounds. These compounds can be used alone or in combination of two or more.

[0097] In addition, as the active energy ray-reactive compound, monomers such as epoxidized butadiene, glycidyl methacrylate, acrylamide, and vinylsiloxane, or oligomers thereof, can be used. The resin material (B2-1) containing these compounds can be cured by high-energy radiation such as ultraviolet rays and electron beams.

[0098] Furthermore, as the above-mentioned active energy ray reactive compound, a mixture of organic salts such as onium salts and compounds having multiple heterocycles in the molecule can be used. The mixture is irradiated by active energy rays (for example, ultraviolet rays, electron beams), and the organic salt is cracked to generate ions, which become starting species and trigger the ring-opening reaction of the heterocycle, thereby forming a three-dimensional network structure. As the above-mentioned organic salts, for example, iodonium salts, phosphonium salts, antimony salts, sulfonium salts, borates, etc. can be listed. As the heterocycle in the compound having multiple heterocycles in the above-mentioned molecule, oxirane, oxolane, thioethane, aziridine, etc. can be listed.

[0099] In the resin material (B2-1) containing the above-mentioned polymer serving as a masterbatch and an active energy ray-reactive compound, the content ratio of the active energy ray-reactive compound relative to 100 parts by weight of the polymer serving as a masterbatch is preferably 0.1 parts by weight to 500 parts by weight, more preferably 1 part by weight to 300 parts by weight, and further preferably 10 parts by weight to 200 parts by weight.

[0100] As the above-mentioned active energy ray reactive polymer, for example, there can be mentioned polymers containing active energy ray reactive functional groups having carbon-carbon multiple bonds such as acryloyl, methacryloyl, vinyl, allyl, and ethynyl. It is preferred to use a compound (polymer) having an ethylenically unsaturated functional group, and more preferably to use a (meth) acrylic polymer having an acryloyl or methacryloyl group. As specific examples of polymers having active energy ray reactive functional groups, there can be mentioned polymers composed of multifunctional (meth) acrylates. The polymer composed of multifunctional (meth) acrylates preferably has an alkyl ester having 4 or more carbon atoms in the side chain, more preferably an alkyl ester having 6 or more carbon atoms, further preferably an alkyl ester having 8 or more carbon atoms, particularly preferably an alkyl ester having 8 to 20 carbon atoms, and most preferably an alkyl ester having 8 to 18 carbon atoms.

[0101] The resin material (B2-2) containing the active energy ray-reactive polymer may further contain the active energy ray-reactive compound (monomer or oligomer).

[0102] The above-mentioned active energy ray curing adhesive can be cured by irradiation with active energy rays. In the adhesive sheet of the present invention, after the adherend is attached before the adhesive is cured, the adhesive is cured by irradiation with active energy rays, thereby making the adherend adhere. Examples of active energy rays include: gamma rays, ultraviolet rays, visible rays, infrared rays (heat rays), radio frequency waves, alpha rays, beta rays, electron beams, plasma streams, ionizing rays, particle rays, etc. The wavelength, irradiation amount, and other conditions of the active energy rays can be set to any appropriate conditions according to the type of resin material used, etc. For example, 10 to 1000 mJ / cm 2 The adhesive is cured by irradiating with ultraviolet rays.

[0103] D. Middle layer

[0104] Examples of the form of the intermediate layer include a resin layer and a layer having adhesive properties.

[0105] In one embodiment, the intermediate layer contains a thermoplastic resin. Such an intermediate layer may be a resin film containing a thermoplastic resin, a layer containing an adhesive C composed of a thermoplastic resin, or the like. In other embodiments, the intermediate layer contains a curable resin (e.g., a UV-curable resin or a thermosetting resin). Such an intermediate layer may be a resin film containing a curable resin, a layer containing a curable adhesive D, or the like.

[0106] The thickness of the intermediate layer is preferably 0.1 μm to 50 μm, more preferably 1 μm to 40 μm, and even more preferably 1.5 μm to 30 μm. Within these ranges, an intermediate layer that functions well as a gas barrier layer can be formed.

[0107] The water vapor permeability of the intermediate layer is preferably 5000 g / (m 2 ·day) or less, more preferably 4800g / (m 2 ·day) or less, more preferably 4500g / (m 2 ·day) or less, more preferably 4200g / (m 2 ·day) or less. If it is within this range, the intermediate layer functions well as a gas barrier layer, forming a deformed portion with an excellent shape. If such an adhesive sheet is used, small adherends (for example, electronic components) can be peeled off with good precision. The lower the water vapor permeability of the intermediate layer, the better, and its lower limit is, for example, 0.1g / (m 2 ·day).

[0108] The puncture strength of the intermediate layer is preferably 300mN to 5000mN, more preferably 500mN to 4500mN, and even more preferably 1000mN to 4000mN. Within this range, the intermediate layer functions effectively as a gas barrier layer, and the shape change caused by gas generation occurs satisfactorily, resulting in a deformed portion with a superior shape. Using such a pressure-sensitive adhesive sheet allows for precise peeling of small adherends (e.g., electronic components).

[0109] The ultraviolet transmittance of the intermediate layer at a wavelength of 360 nm is preferably 50% to 100%, more preferably 60% to 95%.

[0110] D-1. Intermediate layer as resin layer

[0111] The intermediate layer serving as the resin layer is formed, for example, from a resin film. Examples of the resin forming the resin film include polyethylene terephthalate resins, polyolefin resins, styrene elastomer resins (e.g., SEBS), UV-curable resins, thermosetting resins, urethane resins, and epoxy resins. In one embodiment, the resin film is formed from a thermoplastic resin.

[0112] The thickness of the resin film is preferably 0.1 μm to 50 μm, more preferably 0.5 μm to 30 μm, and even more preferably 1 μm to 20 μm.

[0113] D-2. Intermediate layer as an adhesive layer

[0114] Examples of the intermediate layer as an adhesive layer include those containing pressure-sensitive adhesives and those containing curable adhesives. Preferably, the intermediate layer contains curable adhesive D. In particular, combining an adhesive layer containing pressure-sensitive adhesive A with an intermediate layer containing curable adhesive D as the adhesive layer yields an adhesive sheet capable of forming a more favorable deformable portion upon laser irradiation. Curable adhesive D can be any of the adhesives described in Section C-2.

[0115] The thickness of the intermediate layer as the adhesive layer is preferably 5 μm to 50 μm, more preferably 5 μm to 30 μm.

[0116] E. Method for manufacturing adhesive sheet

[0117] The adhesive sheet of the present invention can be manufactured by any appropriate method. Regarding the adhesive sheet of the present invention, for example, the following method can be cited: directly applying a gas generation layer forming composition containing adhesive A and an ultraviolet absorber on a predetermined substrate to form a gas generation layer, and applying an adhesive layer forming composition containing adhesive B on the gas generation layer to form an adhesive layer. In one embodiment, when the adhesive sheet has an intermediate layer, before forming the adhesive layer, the intermediate layer forming composition is applied to the gas generation layer to form an intermediate layer, and the adhesive layer forming composition is applied to the intermediate layer to form an adhesive layer. In addition, the adhesive sheet can also be formed by laminating after each layer is formed.

[0118] As a coating method for the above-mentioned composition, any appropriate coating method can be adopted. For example, each layer can be formed by drying after coating. As a coating method, for example, a coating method using a multi-layer coater (multi coater), a die coater, a gravure coater, an applicator, etc. can be mentioned. As a drying method, for example, natural drying, heat drying, etc. can be mentioned. The heating temperature in the case of heat drying can be set to any appropriate temperature according to the characteristics of the material to be dried. In addition, active energy ray irradiation (for example, ultraviolet irradiation) can be performed according to the form of each layer.

[0119] F. Processing methods of electronic components

[0120] The electronic component processing method of the present invention comprises: attaching the electronic component to the adhesive sheet; and irradiating the adhesive sheet with laser light to peel the electronic component from the adhesive sheet. Examples of the electronic component include semiconductor chips, LED chips, and MLCCs.

[0121] The electronic components can be peeled off at selected locations. Specifically, a plurality of electronic components can be attached and fixed to the pressure-sensitive adhesive sheet, and the electronic components can be peeled off in such a manner that some of the electronic components are peeled off while the other electronic components remain fixed.

[0122] In one embodiment, the electronic component processing method of the present invention includes performing a predetermined treatment on the electronic component after attaching the electronic component to an adhesive sheet and before removing the electronic component from the adhesive sheet. The treatment is not particularly limited and includes, for example, polishing, dicing, die bonding, wire bonding, etching, vapor deposition, molding, circuit formation, inspection, product testing, cleaning, transfer, alignment, repair, and device surface protection.

[0123] The size of the electronic component (the area of the attachment surface) is, for example, 1 μm. 2 ~250000μm 2 In one embodiment, the size of the electronic component (the area of the attachment surface) can be reduced to 1 μm.2 ~6400μm 2 In other embodiments, the size of the electronic component (the area of the attachment surface) can be 1 μm. 2 ~2500μm 2 electronic components for processing.

[0124] In one embodiment, a plurality of electronic components can be arranged on the adhesive sheet as described above. The spacing between the electronic components is, for example, 1 μm to 500 μm. This is advantageous in that the object to be processed can be temporarily fixed with a reduced spacing.

[0125] As the laser, for example, UV laser can be used. The irradiation power of the laser is, for example, 1 μJ to 1000 μJ. The wavelength of the UV laser is, for example, 240 nm to 380 nm.

[0126] In one embodiment, the method for handling an electronic component includes placing the electronic component on another sheet (eg, an adhesive sheet, a substrate, etc.) after peeling the electronic component.

[0127] Example

[0128] The present invention is described in detail below using examples, but the present invention is not limited to these examples. The evaluation methods in the examples are as follows. It should be noted that the following evaluations used adhesive sheets after the separator was removed. In the examples, "parts" and "%" are by weight unless otherwise specified.

[0129] (1) Transmittance

[0130] For PSA sheets with an intermediate layer, place the sheet in a spectrophotometer (trade name "UV-VIS Spectrophotometer SolidSpec 3700," manufactured by Shimadzu Corporation) with incident light perpendicular to the gas barrier layer side of the sample. The transmittance in the wavelength range of 300 nm to 800 nm is measured. The transmittance at a wavelength of 360 nm is extracted from the resulting transmission spectrum. For PSA sheets consisting solely of an PSA layer, the sheet is placed in the spectrophotometer with one release liner remaining, and the transmittance spectrum of the release liner itself is measured and subtracted to obtain the transmittance spectrum of the PSA layer itself. The transmittance at a wavelength of 360 nm is extracted from the resulting transmission spectrum.

[0131] (2) Maximum gas generation peak temperature

[0132] Approximately 0.5 mg of the adhesive sheet sample was placed in a furnace-type pyrolyzer, and the components volatilized by heating were analyzed by EGA-MS, which provides a mass spectrum. The temperature was raised from 40°C to 500°C at a rate of 10°C / minute using a furnace-type pyrolyzer (manufactured by Frontier Laboratories Ltd., trade name "PY2020iD"). The maximum gas generation peak temperature was calculated from the mass spectrum in the mass range of m / z = 10 to 800 using a GC / MS analyzer (manufactured by JEOL, trade name "JMS-T100GCV").

[0133] (3) Gasification starting temperature

[0134] The pressure-sensitive adhesive sheet was heated in the same manner as in (2) above, and the gas generation start temperature calculated by EGA analysis was defined as the gasification initiation temperature. The gas generation start temperature was defined as the temperature reaching the half-maximum value of the gas generation peak in the EGA / MS chromatogram obtained by EGA analysis.

[0135] (4) Type of gas generated

[0136] The PSA sheet sample was placed in an automatic sample combustion apparatus (manufactured by Mitsubishi Chemical Analytech Co., Ltd., trade name "AQF-2100H") and the generated gas was collected by heating at 400° C. for 30 minutes. The captured liquid was analyzed by ion chromatography to identify the type of generated gas.

[0137] (5) 5% weight loss temperature

[0138] The pressure-sensitive adhesive sheet was measured using a differential thermal analyzer (manufactured by TA Instruments, trade name "Discovery TGA") at a temperature increase of 10°C / min, an N2 atmosphere, and a flow rate of 25 ml / min at a temperature at which the weight of the sheet decreased by 5%.

[0139] (6) 10% weight loss temperature

[0140] The temperature at which the weight of the PSA sheet decreased by 10% was measured using a differential thermal analyzer (manufactured by TA Instruments, trade name "Discovery TGA") under the conditions of a temperature increase of 10°C / min, an N2 atmosphere, and a flow rate of 25 ml / min.

[0141] The 10% weight loss temperature was measured for each of the pressure-sensitive adhesive sheet and the gas-generating layer (UV absorber).

[0142] (7) Water vapor transmission rate

[0143] A sample was attached to cover the opening of an aluminum jig with a 10 mm x 10 mm opening to create a measurement sample. The sample was placed between the first and second chambers of a water vapor permeability tester (permatran-w3 / 34g, manufactured by MOCON) and evaluated using the MOCON method. The temperature and humidity conditions were 30°C / 90% RH, the gas (water vapor) flow rate was 10.0 ± 0.5 cc / min, and the measurement time was 20 hours.

[0144] The water vapor transmission rates of the adhesive sheet, adhesive layer, and intermediate layer were measured respectively.

[0145] (8) Surface shape changes

[0146] A measurement sample was prepared by laminating a glass plate (Matsunami Glass Co., Ltd., large glass slide S9112 (standard large white-edge polished No. 2)) to the gas-generating layer side of the pressure-sensitive adhesive sheet (the side opposite the pressure-sensitive adhesive layer). A UV laser with a wavelength of 355 nm and a beam diameter of approximately 20 μm was pulsed at 0.80 mW power and 40 kHz frequency from the glass plate side of the measurement sample to generate gas from the gas-generating layer. The pressure-sensitive adhesive layer surface corresponding to any point of the pulsed laser was observed using a confocal laser microscope one minute after laser irradiation, and the vertical displacement Y and horizontal displacement X (diameter; full width at half maximum) were measured.

[0147] When the displacement Y is 8 μm or more, the peeling property is significantly excellent (◎ in the table); when the displacement Y is 0.6 μm or more and less than 8 μm, the peeling property is good (○ in the table); when the displacement Y is less than 0.6 μm, the peeling property is insufficient (× in the table).

[0148] (9) Adhesion (gas generation layer side)

[0149] A measurement sample was prepared by laminating PET#25 to the adhesive layer side of the PSA sheet. The adhesive strength of the gas-generating layer side of the measurement sample to SUS430 was measured according to JIS Z 0237:2000 (lamination conditions: 1 reciprocating motion of a 2 kg roller, tensile speed: 300 mm / min, peel angle: 180°).

[0150] (10) Adhesion (adhesive layer)

[0151] A measurement sample was prepared by laminating PET#25 to the gas-generating layer side of the PSA sheet. The adhesive strength of the PSA layer side of the measurement sample to SUS430 was measured according to JIS Z 0237:2000 (lamination conditions: 1 round trip of a 2 kg roller, tensile speed: 300 mm / min, peel angle: 180°).

[0152] (11) In-plane uniformity of deformation

[0153] As shown in the above (8), the gas generation layer is irradiated with UV laser light.

[0154] Microscopic observation of randomly selected deformed areas of a 2 mm x 2 mm area indicated good (◯ in the table), acceptable (△ in the table), and poor (× in the table) when 90% or more of the convex areas were identical. Identical dimensions refer to a difference in displacement X of within ±20%.

[0155] (12) Positional selectivity of deformation

[0156] The gas generation layer is irradiated with UV laser light as described in (8) above.

[0157] The case where only a single deformation occurred in the laser irradiation part was rated as acceptable (◯), and the case where multiple deformations also occurred around the laser irradiation part was rated as unacceptable (×).

[0158] (13) Elastic modulus

[0159] Using a nanoindenter (Triboindenter TI-950 manufactured by Hysitron Inc.), the elastic modulus of the gas generation layer cross section was measured using a single indentation method at a specified temperature (25°C) under the measurement conditions of an indentation speed of approximately 500 nm / sec, a withdrawal speed of approximately 500 nm / sec, and an indentation depth of approximately 1500 nm.

[0160] [Manufacturing Example 1] Preparation of Adhesive a

[0161] 30 parts by weight of 2-ethylhexyl acrylate, 70 parts by weight of ethyl acrylate, 4 parts by weight of 2-hydroxyethyl acrylate, 5 parts by weight of methyl methacrylate, and 0.2 parts by weight of benzoyl peroxide as a polymerization initiator were added to toluene, and the mixture was heated to 70° C. to obtain a toluene solution of an acrylic copolymer (polymer A).

[0162] Adhesive a was prepared by mixing a toluene solution of polymer A (polymer A: 100 parts by weight), 3 parts by weight of an isocyanate crosslinking agent (trade name "Coronate L" manufactured by Nippon Polyurethane Co., Ltd.), and 5 parts by weight of a surfactant (trade name "EXCEPARL IPP" manufactured by Kao Corporation). The composition of Adhesive a is shown in Table 1.

[0163] [Manufacturing Example 2] Preparation of Adhesive b

[0164] 95 parts by weight of 2-ethylhexyl acrylate, 5 parts by weight of acrylic acid, and 0.15 parts by weight of benzoyl peroxide as a polymerization initiator were added to ethyl acetate, and then heated to 70° C. to obtain an ethyl acetate solution of an acrylic copolymer (polymer A2).

[0165] Adhesive b was prepared by mixing an ethyl acetate solution of polymer A2 (polymer A2: 100 parts by weight), 1 part by weight of an epoxy crosslinking agent (trade name "TETRAD-C" manufactured by Mitsubishi Gas Chemical Co., Ltd.), and 3 parts by weight of an isocyanate crosslinking agent (trade name "Coronate L" manufactured by Nippon Polyurethane Co., Ltd.). The composition of adhesive b is shown in Table 1.

[0166] [Manufacturing Example 3] Preparation of Adhesive I

[0167] Adhesive I was prepared in the same manner as in Production Example 1 except that the amount of the crosslinking agent added was 1 part by weight and no surfactant was contained. The composition of Adhesive I is shown in Table 1.

[0168] [Manufacturing Example 3'] Preparation of Adhesive c

[0169] Adhesive I was prepared in the same manner as in Production Example 2 except that the amount of the isocyanate crosslinking agent and the epoxy crosslinking agent were changed to 1 part by weight and 0.4 part by weight, respectively.

[0170] [Table 1]

[0171]

[0172] [Manufacturing Example 4] Preparation of Intermediate Layer Forming Composition a

[0173] 30 parts by weight of 2-ethylhexyl acrylate, 70 parts by weight of methyl acrylate, 10 parts by weight of acrylic acid, and 0.2 parts by weight of benzoyl peroxide as a polymerization initiator were added to ethyl acetate, and then heated to 70° C. to obtain an ethyl acetate solution of an acrylic copolymer (polymer B).

[0174] An ethyl acetate solution of polymer B (polymer B: 100 parts by weight), 1 part by weight of an epoxy crosslinking agent (trade name "TETRAD C" manufactured by Mitsubishi Gas Chemical Co., Ltd.), 50 parts by weight of a UV oligomer (trade name "Ziguang UV-1700B" manufactured by Mitsubishi Chemical Corporation), and 3 parts by weight of a photopolymerization initiator (trade name "Omnirad 127" manufactured by BASF) were mixed to prepare an intermediate layer-forming composition a. The composition of the intermediate layer-forming composition a is shown in Table 2.

[0175] [Manufacturing Example 5] Preparation of Intermediate Layer Forming Composition b

[0176] An intermediate layer-forming composition b was prepared by mixing 100 parts by weight of a maleic acid-modified styrene-ethylene-butylene-styrene block copolymer (SEBS: styrene moiety / ethylene-butylene moiety (weight ratio) = 30 / 70, acid value: 10 (mg-CH₃ONa / g), manufactured by Asahi Kasei Chemicals Corporation, trade name "Tuftec M1913"), 3 parts by weight of an epoxy crosslinking agent (manufactured by Mitsubishi Gas Chemical Co., Ltd., trade name "TETRAD-C"), 3 parts by weight of a fatty acid ester surfactant (manufactured by Kao Corporation, trade name "EXCEPARL IPP", molecular weight: 298.5, alkyl group carbon number: 16), and toluene as a solvent. The composition of intermediate layer-forming composition b is shown in Table 2.

[0177] [Table 2]

[0178]

[0179] [Manufacturing Example 6] Preparation of Composition a for Forming a Gas Generation Layer

[0180] Polymer A was obtained in the same manner as in Production Example 1.

[0181] A toluene solution of polymer A (polymer A: 100 parts by weight), 1.5 parts by weight of an isocyanate crosslinking agent (trade name "Coronate L" manufactured by Nippon Polyurethane Co., Ltd.), and 20 parts by weight of a UV absorber (trade name "Tinuvin 477" manufactured by BASF) were mixed to prepare a gas generation layer-forming composition a. The composition of the gas generation layer-forming composition a is shown in Table 3.

[0182] [Production Example 7] Preparation of Composition b for Forming Gas Generation Layer

[0183] A composition b for forming a gas generation layer was prepared in the same manner as in Production Example 5 except that the amount of the UV absorber added was 10 parts by weight.

[0184] [Production Example 8] Preparation of Composition c for Forming a Gas Generation Layer

[0185] A gas generation layer-forming composition c was prepared in the same manner as in Production Example 5, except that 10 parts by weight of 2,4-bis(2-hydroxy-4-butoxyphenyl)-6-(2,4-dibutoxyphenyl)-1,3,5-triazine (trade name "TINUVIN 460", manufactured by BASF) was used as a UV absorber. The composition of the gas generation layer-forming composition c is shown in Table 3.

[0186] [Production Example 9] Preparation of Composition d for Forming a Gas Generation Layer

[0187] A gas generation layer-forming composition d was prepared in the same manner as in Preparation Example 5, except that 20 parts by weight of a reaction product of 2-(4,6-bis(2,4-dimethylphenyl)-1,3,5-triazin-2-yl)-5-hydroxyphenyl and [(C10-C16 (mainly C12-C13)alkoxy)methyl]oxirane (trade name "TINUVIN 400", manufactured by BASF) was used as a UV absorber. The composition of the gas generation layer-forming composition d is shown in Table 3.

[0188] [Manufacturing Example 10] Preparation of Composition e for Forming Gas Generation Layer

[0189] A gas generation layer-forming composition e was prepared in the same manner as in Production Example 5, except that 20 parts by weight of 2-[5-chloro-2H-benzotriazol-2-yl]-4-methyl-6-(tert-butyl)phenol (trade name "TINUVIN 326", manufactured by BASF) was used as a UV absorber. The composition of the gas generation layer-forming composition e is shown in Table 3.

[0190] [Manufacturing Example 11] Preparation of Composition f for Forming Gas Generation Layer

[0191] Polymer B was obtained in the same manner as in Production Example 3.

[0192] A gas generation layer-forming composition f was prepared by mixing an ethyl acetate solution of polymer B (polymer B: 100 parts by weight), 1 part by weight of an isocyanate crosslinking agent (trade name "Coronate L" manufactured by Nippon Polyurethane Co., Ltd.), and 20 parts by weight of a UV absorber (trade name "Tinuvin 477" manufactured by BASF). The composition of the gas generation layer-forming composition f is shown in Table 3.

[0193] [Manufacturing Example 12] Preparation of Composition g for Forming Gas Generation Layer

[0194] 95 parts by weight of 2-ethylhexyl acrylate, 5 parts by weight of acrylic acid, and 0.15 parts by weight of benzoyl peroxide as a polymerization initiator were added to ethyl acetate, and then heated to 70° C. to obtain an ethyl acetate solution of an acrylic copolymer (polymer C).

[0195] An ethyl acetate solution of polymer C (polymer C: 100 parts by weight), 1 part by weight of an isocyanate crosslinking agent (trade name "Coronate L" manufactured by Nippon Polyurethane Co., Ltd.), and 20 parts by weight of a UV absorber (trade name "Tinuvin 477" manufactured by BASF) were mixed to prepare a gas generation layer-forming composition g. The composition of the gas generation layer-forming composition g is shown in Table 3.

[0196] [Manufacturing Example 13] Preparation of Composition h for Forming a Gas Generation Layer

[0197] 95 parts by weight of 2-ethylhexyl acrylate, 5 parts by weight of acrylic acid, and 0.15 parts by weight of benzoyl peroxide as a polymerization initiator were added to ethyl acetate, and then heated to 70° C. to obtain an ethyl acetate solution of an acrylic copolymer (polymer C).

[0198] A gas generation layer-forming composition h was prepared by mixing an ethyl acetate solution of polymer C (polymer C: 100 parts by weight), 0.1 parts by weight of an epoxy crosslinking agent (trade name "TETRAD-C" manufactured by Mitsubishi Gas Chemical Co., Ltd.), and 20 parts by weight of a UV absorber (trade name "Tinuvin 477" manufactured by BASF). The composition of the gas generation layer-forming composition h is shown in Table 3.

[0199] [Production Example 14] Preparation of Composition i for Forming Gas Generation Layer

[0200] A gas generation layer-forming composition i was prepared by mixing 100 parts by weight of a maleic acid-modified styrene-ethylene-butylene-styrene block copolymer (SEBS: styrene moiety / ethylene-butylene moiety (weight ratio) = 30 / 70, acid value: 10 (mg-CH₃ONa / g), manufactured by Asahi Kasei Chemicals Corporation, trade name "Tuftec M1913"), 3 parts by weight of an epoxy crosslinking agent (manufactured by Mitsubishi Gas Chemical Co., Ltd., trade name "TETRAD-C"), 20 parts by weight of a UV absorber (manufactured by BASF, trade name "Tinuvin 477"), and toluene as a solvent. The composition of the gas generation layer-forming composition i is shown in Table 3.

[0201] [Manufacturing Example 15] Preparation of Composition I for Forming Gas Generation Layer

[0202] A composition I for forming a gas generation layer was prepared in the same manner as in Production Example 5 except that no ultraviolet absorber was added. The composition of the composition I for forming a gas generation layer is shown in Table 3.

[0203] [Manufacturing Example 16] Preparation of Composition I Containing Heat-Expandable Microspheres

[0204] Without mixing ultraviolet light absorber, the mixing amount of crosslinking agent is made into 1.4 weight parts, mixing heat-expandable microspheres (Matsumoto Oil Pharmaceutical Co., Ltd. manufactures, trade name " Matsumoto Microsphere F-50D ") 30 weight parts and terpene phenol system tackifying resin (Sumitomo Bakelite Co., Ltd. manufactures, trade name " Sumilite resin PR51732 ") 10 weight parts, except this, operate similarly to Manufacturing Example 5, prepare composition I containing heat-expandable microspheres.

[0205] [Manufacturing Example 17] Preparation of Composition II Containing Heat-Expandable Microspheres

[0206] A composition II containing heat-expandable microspheres was prepared in the same manner as in Production Example 13, except that 20 parts by weight of a terpene-phenol tackifying resin (manufactured by Sumitomo Bakelite Co., Ltd. and trade name "Sumilite resin PR51732") was used instead of 10 parts by weight of a terpene-phenol tackifying resin (manufactured by Yasuhara Chemical Co., Ltd. and trade name "YS polyster T160").

[0207] [Production Example 14'] Preparation of Composition j for Forming Gas Generation Layer

[0208] 95 parts by weight of 2-ethylhexyl acrylate, 5 parts by weight of acrylic acid, and 0.15 parts by weight of benzoyl peroxide as a polymerization initiator were added to ethyl acetate, and then heated to 70° C. to obtain an ethyl acetate solution of an acrylic copolymer (polymer C).

[0209] A gas generation layer-forming composition j was prepared by mixing an ethyl acetate solution of polymer C (polymer C: 100 parts by weight), 1 part by weight of an isocyanate crosslinking agent (trade name "Coronate L" manufactured by Nippon Polyurethane Co., Ltd.), 0.1 part by weight of an epoxy crosslinking agent (trade name "TETRAD-C" manufactured by Mitsubishi Gas Chemical Co., Ltd.), and 10 parts by weight of a UV absorber (trade name "TINUVIN 400" manufactured by BASF). The composition of gas generation layer-forming composition j is shown in Table 3.

[0210] [Production Example 14] Preparation of Composition K for Forming a Gas Generation Layer

[0211] A composition k for forming a gas generation layer was prepared in the same manner as in Production Example 14 except that the amount of the UV absorber added was 5 parts by weight.

[0212] [Table 3]

[0213]

[0214] [Example 1]

[0215] The adhesive a obtained in Manufacturing Example 1 was applied to a polyethylene terephthalate film (thickness: 75 μm) with a silicone release agent-treated surface so that the thickness after solvent volatilization (drying) was 15 μm, and then dried to form an adhesive layer precursor layer a on the polyethylene terephthalate film.

[0216] The gas generation layer forming composition a obtained in Manufacturing Example 5 is coated on a polyethylene terephthalate film (manufactured by Toray Industries, Ltd., trade name "Cerapeel", thickness: 38 μm) with a silicone release agent-treated surface so that the thickness after solvent evaporation (drying) is 7 μm, and then dried to form a gas generation layer precursor layer a on the polyethylene terephthalate film.

[0217] The PSA layer precursor layer a and the gas generation layer precursor layer a were laminated and bonded between rolls to obtain a PSA sheet (PSA layer / gas generation layer) sandwiched between a polyethylene terephthalate film having a silicone release agent-treated surface.

[0218] The obtained PSA sheet was subjected to the above-mentioned evaluations (1) to (12). The results are shown in Table 4.

[0219] [Example 2]

[0220] The adhesive a obtained in Manufacturing Example 1 was applied to a polyethylene terephthalate film (thickness: 75 μm) with a silicone release agent-treated surface so that the thickness after solvent volatilization (drying) was 15 μm, and then dried to form an adhesive layer precursor layer a on the polyethylene terephthalate film.

[0221] The intermediate layer forming composition a obtained in Manufacturing Example 3 is applied to a polyethylene terephthalate film (manufactured by Toray Industries, Ltd., trade name "Cerapeel", thickness: 38 μm) with a silicone release agent-treated surface so that the thickness after solvent evaporation (drying) is 15 μm, and then dried to form an intermediate layer precursor layer a on the polyethylene terephthalate film.

[0222] Next, the adhesive layer precursor layer a and the intermediate layer precursor layer a were laminated between rolls and bonded together. The intermediate layer precursor layer was heated at 500 mJ / cm 2 UV irradiation was performed under the conditions of to obtain a laminate precursor layer a sandwiched between polyethylene terephthalate films with silicone release agent-treated surfaces.

[0223] The gas generation layer forming composition a obtained in Manufacturing Example 5 is coated on a polyethylene terephthalate film (manufactured by Toray Industries, Ltd., trade name "Cerapeel", thickness: 38 μm) with a silicone release agent-treated surface so that the thickness after solvent evaporation (drying) is 7 μm, and then dried to form a gas generation layer precursor layer a on the polyethylene terephthalate film.

[0224] After peeling off the polyethylene terephthalate film with the silicone release agent treated surface on the intermediate layer precursor layer a side of the above-mentioned laminate precursor layer a, the intermediate layer precursor layer a of the laminate precursor layer a and the above-mentioned gas generation layer precursor layer a are laminated and bonded between rollers to obtain an adhesive sheet (adhesive layer / intermediate layer / gas generation layer) clamped by the polyethylene terephthalate film with the silicone release agent treated surface.

[0225] The obtained PSA sheet was subjected to the above-mentioned evaluations (1) to (12). The results are shown in Table 4.

[0226] [Example 3]

[0227] The adhesive a obtained in Manufacturing Example 1 was applied to a polyethylene terephthalate film (thickness: 75 μm) with a silicone release agent-treated surface so that the thickness after solvent volatilization (drying) was 15 μm, and then dried to form an adhesive layer precursor layer a on the polyethylene terephthalate film.

[0228] The intermediate layer forming composition b obtained in Manufacturing Example 4 is applied to a polyethylene terephthalate film (manufactured by Toray Industries, Ltd., trade name "Cerapeel", thickness: 38 μm) with a silicone release agent-treated surface so that the thickness after solvent evaporation (drying) is 15 μm, and then dried to form an intermediate layer precursor layer a on the polyethylene terephthalate film.

[0229] Next, the pressure-sensitive adhesive layer precursor layer a and the intermediate layer precursor layer b were laminated and bonded between rolls to obtain a laminate precursor layer b sandwiched between the polyethylene terephthalate film having a silicone release agent-treated surface.

[0230] The gas generation layer forming composition a obtained in Manufacturing Example 5 is coated on a polyethylene terephthalate film (manufactured by Toray Industries, Ltd., trade name "Cerapeel", thickness: 38 μm) with a silicone release agent-treated surface so that the thickness after solvent evaporation (drying) is 7 μm, and then dried to form a gas generation layer precursor layer a on the polyethylene terephthalate film.

[0231] After peeling off the polyethylene terephthalate film with a silicone release agent-treated surface on the intermediate layer precursor layer b side of the above-mentioned laminate precursor layer b, the intermediate layer precursor layer b of the laminate precursor layer b and the above-mentioned gas generation layer precursor layer a are laminated and bonded between rollers to obtain an adhesive sheet (adhesive layer / intermediate layer / gas generation layer) clamped by the polyethylene terephthalate film with a silicone release agent-treated surface.

[0232] The obtained PSA sheet was subjected to the above-mentioned evaluations (1) to (12). The results are shown in Table 4.

[0233] [Example 4]

[0234] The adhesive a obtained in Manufacturing Example 1 was applied to a polyethylene terephthalate film (thickness: 75 μm) with a silicone release agent-treated surface so that the thickness after solvent volatilization (drying) was 15 μm, and then dried to form an adhesive layer precursor layer a on the polyethylene terephthalate film.

[0235] The gas generation layer forming composition a obtained in Manufacturing Example 5 is coated on a polyethylene terephthalate film (manufactured by Toray Industries, Ltd., trade name "Cerapeel", thickness: 38 μm) with a silicone release agent-treated surface so that the thickness after solvent evaporation (drying) is 7 μm, and then dried to form a gas generation layer precursor layer a on the polyethylene terephthalate film.

[0236] The pressure-sensitive adhesive layer precursor layer a was laminated between rolls and attached to one side of a polyethylene terephthalate film (manufactured by Toray Industries, Ltd., trade name "Lumirror #2F51N," thickness: 2 μm).

[0237] Next, the gas generation layer precursor layer a was laminated between rolls and bonded to the side of the polyethylene terephthalate film opposite to the adhesive layer precursor layer a.

[0238] In this manner, a pressure-sensitive adhesive sheet (pressure-sensitive adhesive layer / intermediate layer / gas generation layer) sandwiched between the polyethylene terephthalate film having the silicone release agent-treated surface was obtained.

[0239] The obtained PSA sheet was subjected to the above-mentioned evaluations (1) to (12). The results are shown in Table 4.

[0240] [Example 5]

[0241] A pressure-sensitive adhesive sheet was obtained in the same manner as in Example 4 except that the gas generation layer-forming composition b was used instead of the gas generation layer-forming composition a. The obtained pressure-sensitive adhesive sheet was subjected to the above-mentioned evaluations (1) to (12). The results are shown in Table 4.

[0242] [Example 6]

[0243] A pressure-sensitive adhesive sheet was obtained in the same manner as in Example 4 except that the gas generation layer-forming composition c was used instead of the gas generation layer-forming composition a. The obtained pressure-sensitive adhesive sheet was subjected to the above-mentioned evaluations (1) to (12). The results are shown in Table 4.

[0244] [Example 7]

[0245] A pressure-sensitive adhesive sheet was obtained in the same manner as in Example 4 except that the gas generation layer-forming composition d was used instead of the gas generation layer-forming composition a. The obtained pressure-sensitive adhesive sheet was subjected to the above-mentioned evaluations (1) to (12). The results are shown in Table 4.

[0246] [Example 8]

[0247] A pressure-sensitive adhesive sheet was obtained in the same manner as in Example 4 except that the gas generation layer-forming composition a was replaced with the gas generation layer-forming composition e. The obtained pressure-sensitive adhesive sheet was subjected to the above-mentioned evaluations (1) to (12). The results are shown in Table 5.

[0248] [Example 9]

[0249] A PSA sheet was obtained in the same manner as in Example 4 except that the thickness of the PSA layer was 1 μm and the thickness of the gas generation layer was 10 μm. The obtained PSA sheet was subjected to the above-mentioned evaluations (1) to (12). The results are shown in Table 5.

[0250] [Example 10]

[0251] A PSA sheet was obtained in the same manner as in Example 4 except that the thickness of the PSA layer was 1 μm and the thickness of the gas generation layer was 15 μm. The obtained PSA sheet was subjected to the above-mentioned evaluations (1) to (12). The results are shown in Table 5.

[0252] [Example 11]

[0253] A PSA sheet was obtained in the same manner as in Example 4 except that the thickness of the PSA layer and the thickness of the gas generation layer were changed to 5 μm. The obtained PSA sheet was subjected to the above-mentioned evaluations (1) to (12). The results are shown in Table 5.

[0254] [Example 12]

[0255] A PSA sheet was obtained in the same manner as in Example 4 except that the thickness of the PSA layer was set to 10 μm and the thickness of the gas generation layer was set to 5 μm. The obtained PSA sheet was subjected to the above-mentioned evaluations (1) to (12). The results are shown in Table 5.

[0256] [Example 13]

[0257] A pressure-sensitive adhesive sheet was obtained in the same manner as in Example 4 except that the gas generation layer-forming composition f was used instead of the gas generation layer-forming composition a. The obtained pressure-sensitive adhesive sheet was subjected to the above-mentioned evaluations (1) to (12). The results are shown in Table 5.

[0258] [Example 14]

[0259] A pressure-sensitive adhesive sheet was obtained in the same manner as in Example 4 except that the gas generation layer-forming composition g was used instead of the gas generation layer-forming composition a. The obtained pressure-sensitive adhesive sheet was subjected to the above-mentioned evaluations (1) to (12). The results are shown in Table 5.

[0260] [Example 15]

[0261] The gas generation layer was formed by coating the gas generation layer-forming composition h on one surface of a polyethylene terephthalate film (manufactured by Toray Industries, Ltd., trade name "Lumirror S10", thickness: 50 μm) so that the thickness after solvent volatilization (drying) was 20 μm.

[0262] Next, the adhesive b was applied to a polyethylene terephthalate film (Toray Industries, Inc., trade name "Cerapeel," thickness: 38 μm) with a silicone release agent-treated surface so that the thickness after solvent volatilization (drying) was 10 μm, thereby forming an adhesive layer.

[0263] Next, the gas generation layer and the adhesive layer were laminated to obtain an adhesive sheet protected by a polyethylene terephthalate film having a silicone release agent-treated surface (adhesive layer / gas generation layer / substrate).

[0264] The obtained PSA sheet was subjected to the above-mentioned evaluation. The results are shown in Table 6.

[0265] [Example 16]

[0266] A PSA sheet was obtained in the same manner as in Example 14 except that the PSA composition i was used instead of the PSA composition h. The obtained PSA sheet was subjected to the above-mentioned evaluation. The results are shown in Table 6.

[0267] [Example 17]

[0268] The gas generation layer was formed by coating the gas generation layer-forming composition j on one surface of a polyethylene terephthalate film (manufactured by Toray Industries, Ltd., trade name "Lumirror S10", thickness: 50 μm) so that the thickness after solvent volatilization (drying) was 20 μm.

[0269] Next, the adhesive a was applied to a polyethylene terephthalate film (Toray Industries, Inc., trade name "Cerapeel," thickness: 38 μm) with a silicone release agent-treated surface so that the thickness after solvent volatilization (drying) was 5 μm, thereby forming an adhesive layer.

[0270] Next, the gas generation layer and the adhesive layer were laminated to obtain an adhesive sheet protected by a polyethylene terephthalate film having a silicone release agent-treated surface (adhesive layer / gas generation layer / substrate).

[0271] The obtained PSA sheet was subjected to the above-mentioned evaluation. The results are shown in Table 6.

[0272] [Example 18]

[0273] A PSA sheet was obtained in the same manner as in Example 17 except that the PSA composition k was used instead of the PSA composition j. The obtained PSA sheet was subjected to the above-mentioned evaluation. The results are shown in Table 6.

[0274] [Table 4]

[0275]

[0276] [Table 5]

[0277]

[0278] [Table 6]

[0279]

[0280] [Comparative Example 1]

[0281] A pressure-sensitive adhesive sheet was obtained in the same manner as in Example 4 except that the gas generation layer-forming composition a was replaced with the gas generation layer-forming composition I. The obtained pressure-sensitive adhesive sheet was subjected to the above-mentioned evaluations (1) to (12). The results are shown in Table 7.

[0282] [Comparative Example 2]

[0283] Instead of Adhesive a, Adhesive I was used, the thickness of the adhesive layer was set to 10 μm, a PET film with a thickness of 188 μm was used as the intermediate layer, and Composition I containing heat-expandable microspheres was used instead of Composition a for forming a gas generation layer to form a 48 μm gas generation layer. The same operation as in Example 4 was performed except that the above-mentioned evaluations (1) to (12) were performed. The results are shown in Table 7.

[0284] [Comparative Example 3]

[0285] Instead of Adhesive a, Adhesive I was used, the thickness of the adhesive layer was set to 10 μm, a 100 μm thick PET film was used as the intermediate layer, and instead of Composition a for forming a gas generation layer, Composition II containing heat-expandable microspheres was used to form a 48 μm gas generation layer. The same procedures as in Example 4 were followed, except that these procedures were followed to obtain an adhesive sheet. The obtained adhesive sheet was subjected to the above-mentioned evaluations (1) to (12). The results are shown in Table 7.

[0286] [Table 7]

[0287]

[0288] Description of Reference Numerals

[0289] 10 Gas Generation Layer

[0290] 20 Adhesive layer

[0291] 30 middle layer

[0292] 100, 200 adhesive sheets

Claims

1. A pressure-sensitive adhesive sheet comprising a gas-generating layer and at least one pressure-sensitive adhesive layer disposed on one side of the gas-generating layer, wherein the pressure-sensitive adhesive layer is composed of a pressure-sensitive adhesive. The adhesive layer is a layer whose surface is deformed by laser irradiation of the adhesive sheet. The amount of deformation of the adhesive layer surface caused by laser irradiation of the adhesive sheet is 0.6 μm or more in terms of vertical displacement of the adhesive layer. The gas generation layer contains an ultraviolet absorber.

2. The adhesive sheet according to claim 1, wherein The thickness of the gas generation layer is 0.1 μm to 50 μm.

3. The adhesive sheet according to claim 1, wherein The gas generating layer is a layer that generates hydrocarbon-based gas.

4. The adhesive sheet according to claim 1, wherein The gasification starting temperature of the gas generating layer is 150°C to 500°C.

5. The adhesive sheet according to claim 1, wherein The elastic modulus Er(gas) [unit: MPa] and thickness h(gas) [unit: μm] of the gas generation layer obtained by nanoindentation method satisfy the following formula (1): Log(Er(gas)×10 6 )≥8.01×h(gas) -0.116 ...(1). The adhesive sheet according to claim 1 , wherein The thickness of the adhesive layer is 0.1 μm to 50 μm.

7. The adhesive sheet according to claim 1, wherein The transmittance of ultraviolet rays with a wavelength of 360nm is 30% or less.

8. The adhesive sheet according to claim 1, wherein The temperature for 10% weight loss is 200°C to 500°C.

9. The adhesive sheet according to claim 1, wherein Water vapor transmission rate is 5000g / (m 2 ·day) or less.

10. A method for processing an electronic component, comprising: an electronic component is attached to the adhesive sheet according to any one of claims 1 to 9; and the adhesive sheet is irradiated with laser light to peel the electronic component from the adhesive sheet.

11. The method for processing electronic components according to claim 10, wherein: The electronic components are peeled off at selected locations.

12. The method for processing electronic components according to claim 10 or 11, comprising: After the electronic component is attached to the adhesive sheet and before the electronic component is peeled off from the adhesive sheet, The electronic component is subjected to prescribed treatment.

13. The method for processing electronic components according to claim 12, wherein: The processing is grinding, dicing, chip bonding, wire bonding, etching, evaporation, molding, circuit formation, inspection, product testing, cleaning, transfer, alignment, repair, or protection of the device surface.

14. The method for processing electronic components according to claim 10 or 11, comprising: After the electronic component is peeled from the pressure-sensitive adhesive sheet, the electronic component is placed on another sheet.

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