Pressure-sensitive adhesive tape for processing electronic parts and process for producing electronic parts

Abstract

To provide an adhesive tape for processing an electronic component capable of suppressing cutting of a base material during water jet laser processing, and a method for manufacturing an electronic component.SOLUTION: The adhesive tape 10 for processing electronic components includes a perforated base material 1 and an adhesive layer 2 disposed on a first surface of the perforated base material, wherein a non-opening part of the perforated base material has an absorption coefficient of 30cm - 1 or less at a predetermined laser wave length.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to an adhesive tape for processing electronic components and a method for manufacturing electronic components. [Background technology]

[0002] Conventionally, substrates to be processed are divided into chips in a dicing process. The dicing process places stress on the chips, which can lead to issues of reduced yield and quality. In recent years, as electronic devices have become more sophisticated, chips have become smaller, thinner, and more highly integrated. As a result, the problems of reduced yield and reduced quality have become more pronounced.

[0003] In recent years, a dicing method using a laser guided by a water jet has been proposed. This method is hereinafter referred to as water jet laser dicing. Water jet laser dicing offers the following advantages: It significantly reduces the mechanical load on the substrate. Therefore, chipping and microcracks are less likely to occur. Because the water jet is used as a guide and the substrate is cooled with water during dicing, thermal load is reduced despite the use of a laser. This reduces heat-related quality degradation. Compared to blade dicing, it uses less water, resulting in less wastewater. It significantly increases the processing speed, shortening processing time and reducing the load. Compared to laser dicing, dicing is performed within the stable range of the water jet, eliminating the need for focal position adjustment. Because the laser is guided by the water jet, the cut surface is perpendicular. This improves reliability. Therefore, it can also be applied to automotive semiconductors. It also allows for narrower chip spacing. The deep depth of focus allows for processing of thick substrates. It is possible to process substrates made of hard materials such as SiC. Therefore, it can also be applied to power semiconductors. It is also possible to process the substrate into a curved shape. The surface of the substrate is protected by water, so there is little adhesion to the surface. This simplifies cleaning work. After penetrating the substrate, the water jet can be used to remove processing debris, so there are fewer burrs on the backside. In this way, water jet laser processing is advantageous for making chips smaller, thinner, and more highly integrated, and is advantageous for improving yield and quality.

[0004] In the dicing process, an adhesive tape called dicing tape is used to protect and secure the substrate and chips. Adhesive tape typically has a substrate and an adhesive layer. In the case of water jet laser processing, if the substrate is impermeable to water, chipping or chipping due to water splashing is likely to occur. Therefore, as described in Patent Documents 1 to 3, for example, porous substrates such as woven fabrics and nonwoven fabrics that are permeable to water are used as the substrates constituting the adhesive tape in water jet laser processing. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 3824874 [Patent Document 2] Patent No. 4087144 [Patent Document 3] Japanese Patent Application Laid-Open No. 2005-167042 Summary of the Invention [Problem to be solved by the invention]

[0006] Some lasers are easily absorbed by water, while others are not. Therefore, in water jet laser processing, the use of short wavelength lasers is being considered to reduce water absorption and increase processing efficiency.

[0007] However, in general, the shorter the wavelength of a laser, the higher the energy and the higher the absorption rate of the laser in a material. Therefore, when a short-wavelength laser is used in water jet laser processing, the porous substrate constituting the adhesive tape may be cut during processing, or the porous substrate may become brittle and easily cut during processing.

[0008] The present disclosure has been made in consideration of the above-described circumstances, and has as its main object to provide an adhesive tape for processing electronic components that can suppress cutting of the substrate during water jet laser processing. [Means for solving the problem]

[0009] One embodiment of the present disclosure is an adhesive tape for processing electronic components, comprising a porous substrate and an adhesive layer disposed on a first surface of the porous substrate, wherein the absorption coefficient of a predetermined laser wavelength at a non-opening portion of the porous substrate is 30 cm or less. -1 The present invention provides the following adhesive tape for processing electronic components.

[0010] Another embodiment of the present disclosure provides a method for manufacturing electronic components, comprising: an attachment step of attaching the above-mentioned adhesive tape for electronic component processing to a first surface of a workpiece substrate; a dicing step of dividing the workpiece substrate into a plurality of chips; and a peeling step of peeling the adhesive tape for electronic component processing from the chips. [Effects of the Invention]

[0011] The present disclosure can provide an adhesive tape for processing electronic components that can suppress cutting of the substrate during water jet laser processing. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a schematic cross-sectional view illustrating an example of an adhesive tape for processing electronic components according to the present disclosure. [Figure 2] 1A and 1B are schematic plan and cross-sectional views illustrating a porous substrate constituting an adhesive tape for processing electronic components according to the present disclosure. [Figure 3] 1 is a schematic cross-sectional view illustrating an example of an adhesive tape for processing electronic components according to the present disclosure. [Figure 4] 1A to 1C are process diagrams illustrating a method for manufacturing an electronic component according to the present disclosure. [Figure 5] 1A to 1C are process diagrams illustrating a method for manufacturing an electronic component according to the present disclosure. [Figure 6] FIG. 1 is a schematic diagram illustrating a method for preparing a test piece used for evaluating scratches. DETAILED DESCRIPTION OF THE INVENTION

[0013] Embodiments of the present disclosure will be described below with reference to the drawings and the like. However, the present disclosure can be implemented in many different forms and should not be limited to the description of the embodiments exemplified below. Furthermore, in order to clarify the description, the drawings may schematically show the width, thickness, shape, etc. of each part compared to the actual form, but these are merely examples and should not be interpreted as being limiting. Furthermore, in this specification and each drawing, elements similar to those described above with reference to the previous drawings will be designated by the same reference numerals, and detailed descriptions may be omitted as appropriate.

[0014] In this specification, when describing a mode in which another component is placed on a certain component, the term "above" or "below" includes, unless otherwise specified, both a case in which another component is placed directly above or below a certain component so as to be in contact with the component, and a case in which another component is placed above or below a certain component with another component interposed therebetween. Also, in this specification, when describing a mode in which another component is placed on the surface of a certain component, the term "on the surface" includes, unless otherwise specified, both a case in which another component is placed directly above or below a certain component so as to be in contact with the component, and a case in which another component is placed above or below a certain component with another component interposed therebetween.

[0015] In this specification, the term "sheet" also includes a member called a "film."

[0016] The adhesive tape for processing electronic components and the method for manufacturing electronic components according to the present disclosure will be described below.

[0017] A. Adhesive tape for electronic component processing The adhesive tape for electronic component processing according to the present disclosure has a porous substrate and an adhesive layer disposed on a first surface of the porous substrate, and the non-opening portion of the porous substrate has an absorption coefficient of 30 cm or less at a predetermined laser wavelength. -1 The following is the result.

[0018] 1 is a schematic cross-sectional view illustrating an example of an adhesive tape for electronic component processing according to the present disclosure. As illustrated in FIG. 1, the adhesive tape for electronic component processing 10 includes a porous substrate 1 and an adhesive layer 2 disposed on a first surface of the porous substrate 1.

[0019] In the present disclosure, by setting the absorption coefficient of the non-opening portion of the porous substrate at a predetermined laser wavelength to a predetermined value or less, cutting of the porous substrate during water jet laser processing can be suppressed.

[0020] Possible factors that cause a porous substrate to cut during water jet laser processing include the strength of the porous substrate and the laser absorption rate of the material of the porous substrate. As described above, in water jet laser processing, the use of a short-wavelength laser has been considered to reduce the absorption rate in water and increase processing efficiency. However, generally, the shorter the laser wavelength, the higher the energy and the higher the absorption rate in materials. Therefore, when a short-wavelength laser is used in water jet laser processing, the porous substrate may be cut during processing, or the porous substrate may become brittle and more likely to be cut during processing. Therefore, the inventors of the present disclosure focused on the laser absorption rate of the material of the porous substrate.

[0021] The laser absorption of the porous substrate material can be determined, for example, by its laser transmittance or laser absorbance. However, the transmittance and absorbance vary depending on the thickness. Therefore, in this disclosure, the laser absorption coefficient is defined, which does not take thickness into consideration.

[0022] In the present disclosure, since the absorption coefficient of the non-opening portion of the porous substrate at a predetermined laser wavelength is equal to or less than a predetermined value, it can be said that the material of the porous substrate itself has a small absorption coefficient at a predetermined laser wavelength. Therefore, during water jet laser processing, the material of the porous substrate is less likely to absorb the laser, so that heat generation due to laser absorption can be suppressed and cutting of the porous substrate can be suppressed. Therefore, the adhesive tape for electronic component processing in the present disclosure can be suitably used when dicing a substrate to be processed by water jet laser processing.

[0023] Hereinafter, each component of the adhesive tape for processing electronic components according to the present disclosure will be described.

[0024] 1. Porous base material The porous substrate in the present disclosure is a member that supports the adhesive layer.

[0025] (1) Characteristics of porous substrate In the present disclosure, the extinction coefficient of the non-apertured porous substrate at a given laser wavelength is 30 cm -1 Less than or equal to 20cm -1 May be less than 10cm -1 The absorption coefficient may be equal to or less than a predetermined value. When the absorption coefficient is equal to or less than a predetermined value, cutting of the porous substrate during water jet laser processing can be suppressed. The smaller the absorption coefficient, the more preferable it is, and the lower limit of the absorption coefficient is not particularly limited.

[0026] The wavelength of the laser is the wavelength of the laser used in water jet laser processing. The wavelength of the laser is preferably the wavelength of a short wavelength laser. Specifically, the wavelength of the laser is preferably 532 nm, which is the second harmonic of a YAG laser, or 355 nm, which is the third harmonic of a YAG laser.

[0027] The absorption coefficient α of the non-opening portion of the porous substrate at a predetermined laser wavelength is calculated by the following formula (1). α=A / L (1) In the above formula, A represents the absorbance of the non-opening portion of the porous substrate at a given laser wavelength, and L represents the optical path length (cm).

[0028] The absorbance A of a given laser wavelength in the non-opening portion of the porous substrate is calculated by the following formula (2). A=-log 10 T (2) In the above formula (2), T represents the transmittance (%) of a given laser wavelength through the non-opening portion of the porous substrate.

[0029] The transmittance T of a non-opening portion of a porous substrate at a predetermined laser wavelength is calculated by the following formula (3). T = (T1-R) / (100-R) × 100 (3) In the above formula (3), T1 represents the transmittance (%) of the porous substrate at a predetermined laser wavelength, and R represents the opening ratio (%) of the porous substrate.

[0030] The aperture ratio R of a porous substrate is the ratio of the area of ​​the openings in the porous substrate in a planar view. The aperture ratio R of a porous substrate is determined by observing the surface of the porous substrate using a scanning electron microscope (SEM) and binarizing the SEM image by image processing. Specifically, first, the surface of the porous substrate is observed at a predetermined magnification using a scanning electron microscope (SEM), and a predetermined region is extracted. The magnification is appropriately set according to the size of the openings in the porous substrate, for example, 100 times or more and 2000 times or less. The size of the predetermined region is 2 mm × 2 mm. Next, image processing is performed on the SEM image of the predetermined region to binarize it into openings and non-openings. The predetermined region is taken as the area of ​​the entire porous substrate, and the ratio of openings, i.e., the aperture ratio, is determined. This operation is performed in the same way for 10 randomly selected locations on the surface of the porous substrate, and the average value is taken as the aperture ratio R of the porous substrate. As the image processing software, commercially available image analysis software or free software can be used, for example, Photoshop by Adobe.

[0031] The optical path length L is calculated by the following formula (4). L=V1 / (2.54) 2(4) In the above formula (4), V1 is the volume of the porous substrate per square inch (cm 3 ) In the above formula (4), the porous substrate is replaced with a flat layer without pores, the thickness of this layer is calculated, and the thickness of this layer is used as the optical path length. In other words, the volume of the porous substrate per square inch is assumed to be the same as the volume of the flat layer without pores per square inch, and the thickness of this layer is calculated.

[0032] The volume V1 of the porous substrate per square inch is calculated differently depending on the shape of the porous substrate.

[0033] When the porous substrate is a woven fabric, the volume V1 of the porous substrate per square inch is calculated by the following formula (5). V1=V2×M×2 (5) In the above formula (5), V2 is the volume (cm ) per inch of the length of one yarn constituting the woven fabric. 3 ), M indicates the mesh, i.e., the number of threads per inch. In the above formula (5), the factor 2 is used because a woven fabric has warp and weft threads.

[0034] The volume V2 per inch of the length of one yarn constituting the woven fabric is calculated by the following formula (6). V2=2.54×(D / 2) 2 ×π (6) In the above formula (6), D represents the average diameter (cm) of the yarn. In the above formula (6), the volume V2 per inch of length of one yarn is calculated assuming that the yarn is 1 inch long and is a cylinder 1 inch high.

[0035] When the porous substrate is a resin film having through-holes, the volume V1 of the porous substrate per square inch is calculated by the following formula (7). V1=(2.54) 2 ×(100-R) / 100×H (7) In the above formula (7), R represents the opening ratio (%) of the porous substrate, and H represents the thickness (cm) of the porous substrate.

[0036] Furthermore, when the porous substrate is a knitted fabric, the volume V1 of the porous substrate per square inch is determined by the following method. First, multiple pieces of 1-inch size are cut out of the knitted fabric to obtain test pieces. Next, water is poured into a 10 mL graduated cylinder with 0.1 mL graduations, and a number of test pieces that result in a change in water level of 0.5 mL or more are submerged in the water. The volume of the knitted fabric is determined from the change in the water level in the graduated cylinder. This measurement is performed 10 times, and the arithmetic mean value of the measured values ​​is taken as the volume V1 of the porous substrate per square inch. When the porous substrate is a knitted fabric, the volume of the knitted fabric is measured by removing the adhesive layer from the adhesive tape for electronic component processing and then removing the porous substrate. An example of a method for removing the adhesive layer is a method in which the adhesive layer is dissolved in a solvent. The solvent that can be used as the solvent is the same as that contained in the adhesive composition used to form the adhesive layer.

[0037] The absorption coefficient of a predetermined laser wavelength in the non-opening portion of the porous substrate can be adjusted by the material of the porous substrate. The absorption coefficient can be reduced by including a laser-transmitting material in the porous substrate. The absorption coefficient can also be reduced by reducing the content of laser-absorbing material in the porous substrate or by not including a laser-absorbing material. The laser-transmitting material transmits a predetermined laser and has a high transmittance for the wavelength of the predetermined laser. On the other hand, the laser-absorbing material absorbs a predetermined laser and has a high absorptance for the wavelength of the predetermined laser.

[0038] Examples of the laser-transmitting material include laser-transmitting resins, which vary depending on the wavelength of the desired laser, and include resins used in porous substrates, which will be described later.

[0039] Examples of laser-absorbing materials include laser-absorbing resins and laser-absorbing agents. The laser-absorbing resin varies depending on the wavelength of the specified laser. For example, when the wavelength of the specified laser is in the ultraviolet region, examples of laser-absorbing resins include resins having aromatic rings. Examples of laser-absorbing agents include colorants, ultraviolet absorbers, and infrared absorbers. Examples of colorants include organic pigments, inorganic pigments, and dyes.

[0040] In particular, it is preferable that the porous substrate is substantially free of laser-absorbing materials. "The porous substrate is substantially free of laser-absorbing materials" means that the content of laser-absorbing materials in the porous substrate is 0.1% by mass or less. The content of laser-absorbing materials in the porous substrate is preferably 0.01% by mass or less, and more preferably 0.001% by mass or less.

[0041] In woven fabrics, it is known to add a filler to the resin composition that constitutes the yarn from the viewpoint of yarn strength, etc. It is also known to add a filler to resin films from the viewpoint of strength, etc. However, if a filler is added, the filler may absorb the laser and cause the woven fabric or resin film to be cut during water jet laser processing. Therefore, it is preferable that the porous substrate is substantially filler-free. The filler is not particularly limited, and any filler used as a resin additive can be used. Examples of fillers include carbonates, silicates, oxides, sulfates, and hydroxides. Examples of carbonates include calcium carbonate. Examples of silicates that can be used include clay, talc, mica, asbestos, feldspar, bentonite, pumice, pyrophyllite, and vermiculite. Examples of oxides include aluminum oxide, magnesium oxide, titanium oxide, and silicon oxide. Examples of sulfates include gypsum. Furthermore, carbon fillers, metal fillers, glass fillers, organic fillers, and the like can also be used as fillers.

[0042] The phrase "the porous substrate is substantially filler-free" means that the filler content in the porous substrate is 0.1% by mass or less. The filler content in the porous substrate is preferably 0.01% by mass or less, and more preferably 0.001% by mass or less.

[0043] (2) Shape of porous substrate Examples of porous substrates include woven fabrics, resin films having through-holes, knitted fabrics, etc. Among these, woven fabrics are preferred.

[0044] (a) Textile The woven material preferably has high transmittance to the laser used in water jet laser processing. Examples of woven materials include chemical fibers, natural fibers, and inorganic fibers. Examples of chemical fiber materials include polyolefin, polyester, polyamide, polycarbonate, acrylic resin, polyvinyl chloride, polyurethane, polystyrene, styrene-ethylene-butene copolymer, styrene-ethylene-pentene copolymer, rayon, and cellulose acetate. Examples of polyolefins include polyethylene, polypropylene, polybutene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer (EVA), ethylene-methyl methacrylate copolymer (EMMA), and ionomer. Examples of polyesters include polyethylene terephthalate. Examples of polyamides include nylon 6, nylon 6,6, nylon 12, and aramid. Examples of natural fiber materials include cotton, silk, and wool. Examples of inorganic fibers include glass fiber and carbon fiber. These materials may be used alone or in combination.

[0045] The weaving method of the woven fabric is not particularly limited, and examples thereof include plain weave, twill weave, and satin weave.

[0046] The warp and weft threads may each be monofilaments or multifilaments, with monofilaments being preferred because they are less likely to break during water jet laser processing.

[0047] 2(a) to 2(c) are schematic plan and cross-sectional views illustrating an example of a woven fabric. FIG. 2(b) is an enlarged view of FIG. 2(a), and FIG. 2(c) is a cross-sectional view of FIG. 2(b). As shown in FIGS. 2(a) to 2(c), woven fabric 1A is composed of warp threads 31 and weft threads 32. In plan view, woven fabric 1A has openings 33 surrounded by warp threads 31 and weft threads 32, and non-openings 34 that have warp threads 31 and weft threads 32 but are not openings 33. In FIGS. 2(a) to 2(c), a1 indicates the diameter of warp threads 31, a2 indicates the diameter of weft threads 32, b1 indicates the opening between warp threads 31, and b2 indicates the opening between weft threads 32.

[0048] The average diameter of the yarn is, for example, 20 μm or more and 1000 μm or less. If the average diameter of the yarn is a predetermined value or more, it is possible to prevent the porous substrate from being cut or weakened by the pressure of the water jet and the heat of the laser during water jet laser processing. Furthermore, if the average diameter of the yarn is a predetermined value or less, sufficient water permeability is obtained. Note that, when the yarn is a multifilament, the average diameter of the yarn refers to the average diameter of the multifilament.

[0049] In particular, the average diameter of the thread is preferably 30 μm or more and 120 μm or less, and more preferably 40 μm or more and 105 μm or less. Here, the adhesive tape for electronic component processing is attached to a ring frame, and a substrate to be processed is fixed to the adhesive tape for electronic component processing. Then, in the dicing process, the substrate to be processed fixed to the adhesive tape for electronic component processing is fixed by suction to a suction table and processed. In this case, if the average diameter of the thread is less than a predetermined value, the unevenness of the surface of the adhesive tape for electronic component processing facing the porous substrate (woven fabric) is reduced, thereby preventing the formation of a gap between the surface of the adhesive tape for electronic component processing facing the porous substrate and the suction table. This reduces the suction force of the suction table due to air leakage from this gap, thereby preventing misalignment during dicing. Specifically, this prevents the cutting position from shifting during dicing.

[0050] Here, the average diameter of yarns is the arithmetic mean value of the diameters of 10 randomly selected warp yarns and 10 randomly selected weft yarns. The diameters of the warp yarns and the weft yarns are measured using a digital microscope.

[0051] The opening rate of the woven fabric is, for example, 10% or more, or may be 20% or more, or 30% or more. The opening rate of the woven fabric is, for example, 80% or less, or may be 70% or less, or may be 60% or less. That is, the opening rate of the woven fabric is, for example, 10% or more and 80% or less, or may be 20% or more and 70% or less, or may be 30% or more and 60% or less. When the opening rate is a predetermined value or more, sufficient water permeability can be obtained. When the opening rate is a predetermined value or less, sufficient adhesion to the adhesive layer can be obtained. The method for measuring the opening rate of the woven fabric is the same as the method for measuring the opening rate of the porous substrate described above.

[0052] The average opening between the threads is preferably smaller than the chip size, for example, on the order of millimeters or less. The average opening between the threads is, for example, 500 μm or less, or may be 200 μm or less, or 100 μm or less. The average opening between the threads is, for example, 1 μm or more, or may be 5 μm or more, or may be 10 μm or more. That is, the average opening between the threads is, for example, 1 μm or more and 500 μm or less, or may be 5 μm or more and 200 μm or less, or may be 10 μm or more and 100 μm or less. If the average opening is a predetermined value or more, sufficient water permeability can be obtained. If the average opening is a predetermined value or less, sufficient adhesion to the adhesive layer can be obtained.

[0053] The average inter-yarn shed is the arithmetic mean value of 10 randomly selected inter-warp sheds and 10 randomly selected inter-weft sheds. The inter-warp shed and inter-weft shed are measured using a digital microscope.

[0054] When measuring the diameter of the warp yarns, the diameter of the weft yarns, the opening between the warp yarns, and the opening between the weft yarns, the adhesive layer is removed from the adhesive tape for processing electronic components, and the porous substrate is taken out. As a method for removing the adhesive layer, a method of dissolving the adhesive layer with a solvent can be used. As the solvent, the solvent contained in the adhesive composition used to form the adhesive layer can be used.

[0055] The surface of the fabric facing the adhesive layer may be subjected to a surface treatment to improve adhesion to the adhesive layer. The surface treatment is not particularly limited, and examples thereof include corona treatment, plasma treatment, ozone treatment, flame treatment, primer treatment, and alkali treatment.

[0056] The thickness of the woven fabric is not particularly limited as long as it can support the adhesive layer. The thickness of the woven fabric is, for example, 50 μm or more, or may be 100 μm or more, or 120 μm or more. The thickness of the woven fabric is, for example, 1000 μm or less, or may be 500 μm or less, or may be 200 μm or less. That is, the thickness of the woven fabric is, for example, 50 μm or more and 1000 μm or less, or may be 100 μm or more and 500 μm or less, or may be 120 μm or more and 200 μm or less.

[0057] The thickness of the porous substrate is measured using a thickness gauge such as a dial thickness gauge or a digital thickness gauge, and the arithmetic average value of the thicknesses at 10 randomly selected locations is used. When measuring the thickness of the porous substrate, the adhesive layer is removed from the adhesive tape for electronic component processing, and the porous substrate is taken out. The method for removing the adhesive layer is as described above.

[0058] (b) Resin film with through holes The resin film material preferably has high transmittance to the laser used in water jet laser processing. Examples of resin film materials include olefin-based resins, vinyl chloride resins, polyester resins, urethane resins, polystyrene resins, polycarbonate resins, fluororesins, thermoplastic elastomers, and rubber-based materials. Examples of olefin-based resins include low-density polyethylene, high-density polyethylene, polypropylene, polybutene, polymethylpentene, polybutadiene, ethylene-vinyl acetate copolymers, ionomer resins, ethylene (meth)acrylic acid copolymers, and ethylene (meth)acrylic acid ester copolymers. Examples of vinyl chloride resins include polyvinyl chloride and vinyl chloride copolymers. Examples of polyester resins include polyethylene terephthalate and polybutylene terephthalate. Examples of thermoplastic elastomers include olefin-based elastomers, vinyl chloride-based elastomers, polyester-based elastomers, styrene-based elastomers, urethane-based elastomers, acrylic elastomers, and amide-based elastomers. Examples of rubber-based materials include isoprene rubber, butadiene rubber, styrene butadiene rubber, chloroprene rubber, acrylonitrile butadiene rubber, butyl rubber, halogenated butyl rubber, acrylic rubber, urethane rubber, polysulfide rubber, etc. These may be used alone or in combination of two or more.

[0059] The resin film may contain additives as needed, such as plasticizers, antioxidants, light stabilizers, antistatic agents, lubricants, dispersants, and flame retardants.

[0060] The resin film has through-holes that penetrate the film in the thickness direction, and the resin film has through-holes that allow the film to be permeable to water.

[0061] In the resin film, the planar shape of the through hole is not particularly limited, and examples thereof include a circle, an ellipse, a triangle, a square, a rectangle, and a hexagon. Among these, the planar shape of the through hole is preferably a rounded shape. If the shape has corners, the resin film is more likely to break from the corners. Therefore, a rounded shape can prevent the resin film from breaking. Specifically, the planar shape of the through hole is preferably a circle, an ellipse, or a polygon with rounded corners, and more preferably a circle or an ellipse.

[0062] The size of the through holes is preferably smaller than the chip size, for example, on the order of millimeters or less. The size of the through holes is, for example, 3 mm or less, or may be 1 mm or less, 500 μm or less, 200 μm or less, or 100 μm or less. On the other hand, the size of the through holes is preferably, for example, 10 μm or more. That is, the size of the through holes is, for example, 10 μm or more to 3 mm or less, 10 μm or more to 1 mm or less, 10 μm or more to 500 μm or less, 10 μm or more to 200 μm or less, or 10 μm or more to 100 μm or less. When the size of the through holes is a predetermined value or more, sufficient water permeability can be obtained. Furthermore, when the size of the through holes is a predetermined value or less, sufficient adhesion to the adhesive layer can be obtained.

[0063] The size of the through hole is the arithmetic average of 10 randomly selected holes. The size of the through hole is defined according to the shape of the through hole in plan view. For example, the size of the through hole refers to the diameter in the case of a circle, the major axis in the case of an ellipse, the diagonal length in the case of a square or rectangle, the maximum height in the case of a triangle, and the maximum diagonal length in the case of a hexagon.

[0064] The through holes may be arranged regularly or irregularly. When the through holes are arranged regularly, the arrangement of the through holes is not particularly limited, and examples thereof include a lattice arrangement and a staggered arrangement.

[0065] The opening rate of the resin film is, for example, 30% or more, or may be 40% or more, or 50% or more. On the other hand, the opening rate of the resin film is, for example, 80% or less, or may be 70% or less, or may be 60% or less. That is, the opening rate of the resin film is, for example, 30% or more and 80% or less, or may be 40% or more and 70% or less, or may be 50% or more and 60% or less. When the opening rate is a predetermined value or more, sufficient water permeability can be obtained. Furthermore, when the opening rate is a predetermined value or less, sufficient adhesion to the adhesive layer can be obtained. The method for measuring the opening rate of the resin film is the same as the method for measuring the opening rate of the porous substrate described above.

[0066] The method for forming through holes in a resin film is not particularly limited, and examples thereof include punching, laser processing, etc. Another method for forming a resin film having through holes is mold printing using gravure printing. In this case, a resin film having through holes is formed on a separator by mold printing using gravure printing, and the separator is peeled off to obtain a resin film having through holes.

[0067] The resin film may be, for example, a single layer or a multilayer.

[0068] The surface of the resin film facing the adhesive layer may be subjected to a surface treatment to improve adhesion to the adhesive layer. The surface treatment is not particularly limited, and examples thereof include corona treatment, plasma treatment, ozone treatment, flame treatment, primer treatment, vapor deposition treatment, and alkali treatment.

[0069] The thickness of the resin film is not particularly limited as long as it can support the adhesive layer. The thickness of the resin film is, for example, 100 μm or more, and may be 150 μm or more. On the other hand, the thickness of the resin film is, for example, 1000 μm or less, may be 500 μm or less, or may be 300 μm or less. Specifically, the thickness of the resin film is 100 μm or more and 1000 μm or less, may be 100 μm or more and 500 μm or less, may be 150 μm or more and 500 μm or less, or may be 150 μm or more and 300 μm or less. The method for measuring the thickness is as described above.

[0070] (c) Knitted fabrics The material of the knitted fabric is the same as the material of the woven fabric. The knitting method of the knitted fabric is not particularly limited.

[0071] The thread may be a monofilament or a multifilament, with a monofilament being preferred because it is less likely to break during water jet laser processing.

[0072] The average diameter of the yarn is the same as that of the yarn of the woven fabric.

[0073] Here, the average diameter of the yarn is the arithmetic mean value of the diameters of 10 randomly selected yarns, which is measured using a digital microscope.

[0074] When measuring the diameter of the thread, the adhesive layer is removed from the adhesive tape for electronic component processing, and the porous substrate is taken out. The method for removing the adhesive layer is as described above.

[0075] The open area ratio of the knitted fabric is the same as that of the woven fabric. The open area ratio of the knitted fabric can be measured by the same method as that of the porous substrate.

[0076] The surface of the knitted fabric facing the adhesive layer may be subjected to a surface treatment in order to improve adhesion to the adhesive layer. The surface treatment may be the same as the surface treatment when the porous substrate is the woven fabric described above.

[0077] The thickness of the knitted fabric is similar to that of the woven fabric.

[0078] 2. Adhesive layer The adhesive layer in the present disclosure is not particularly limited as long as it can sufficiently fix the substrate and chip to the adhesive tape for electronic component processing in the dicing step, and can easily peel the chip from the adhesive tape for electronic component processing in the peeling step. Examples of adhesive layers include an energy ray-curable adhesive layer having energy ray curability and a weak adhesive layer exhibiting weak adhesiveness. Of these, an energy ray-curable adhesive layer is preferred. An energy ray-curable adhesive layer can increase the initial adhesive strength. Each adhesive layer will be described below.

[0079] (1) Energy ray curable adhesive layer The energy ray-curable adhesive layer is an adhesive layer whose adhesive strength decreases when irradiated with energy rays. In the energy ray-curable adhesive layer, the initial adhesive strength allows the substrate and chip to be sufficiently fixed to the adhesive tape for electronic component processing during the dicing process. Furthermore, during the peeling process, the adhesive strength decreases and the peelability improves when irradiated with energy rays, allowing the chip to be easily peeled from the adhesive tape for electronic component processing.

[0080] Examples of energy rays include light rays such as far ultraviolet rays, ultraviolet rays, near ultraviolet rays, and infrared rays, electromagnetic waves such as X-rays and gamma rays, as well as electron beams, proton beams, neutron beams, etc. Among these, from the viewpoint of versatility, ultraviolet rays and electron beams are preferred, and ultraviolet rays are more preferred.

[0081] The energy ray-curable adhesive layer is not particularly limited as long as it satisfies the adhesive properties described below, and may contain, for example, at least a resin (main adhesive agent) and an energy ray-curable compound. When the adhesive layer contains the energy ray-curable compound, the adhesive strength can be reduced by curing the energy ray-curable compound by irradiation with energy rays, and at the same time, the cohesive force is increased, making it easier to peel.

[0082] (a) Resin (main adhesive) Examples of resins (adhesive bases) include resins generally used as bases for adhesives, such as acrylic resins, polyester resins, polyimide resins, and silicone resins. Among these, acrylic resins are preferred. By using acrylic resins, adhesive residue on the adherend can be reduced.

[0083] Therefore, the adhesive layer preferably contains at least an acrylic resin, an energy ray-curable compound, and a crosslinking agent. In the adhesive layer, the acrylic resin is usually present as a crosslinked body formed by crosslinking between acrylic resin molecules with the crosslinking agent, but the acrylic resin may also be present as a simple substance together with the crosslinked body.

[0084] (acrylic resin) The acrylic resin is not particularly limited, and examples thereof include (meth)acrylic acid ester polymers obtained by homopolymerizing (meth)acrylic acid esters, and (meth)acrylic acid ester copolymers obtained by copolymerizing (meth)acrylic acid esters with other monomers and (meth)acrylic acid esters as the main component. Among these, (meth)acrylic acid ester copolymers are preferred. Specific examples of (meth)acrylic acid esters and other monomers include those disclosed in JP 2012-31316 A. The other monomers can be used alone or in combination of two or more. Here, "main component" means that the copolymerization ratio is 51% by mass or more, preferably 65% ​​by mass or more.

[0085] Among these, as the acrylic resin, a (meth)acrylic acid ester copolymer having a (meth)acrylic acid ester as the main component and obtained by copolymerizing a hydroxyl group-containing monomer copolymerizable with the (meth)acrylic acid ester, or a (meth)acrylic acid ester copolymer having a (meth)acrylic acid ester as the main component and obtained by copolymerizing a hydroxyl group-containing monomer and a carboxyl group-containing monomer copolymerizable with the (meth)acrylic acid ester can be suitably used.

[0086] In this specification, (meth)acrylic acid refers to at least one of acrylic acid and methacrylic acid.

[0087] The copolymerizable hydroxyl group-containing monomer and carboxyl group-containing monomer are not particularly limited, and for example, the hydroxyl group-containing monomer and carboxyl group-containing monomer disclosed in JP-A-2012-31316 can be used.

[0088] The weight-average molecular weight of the acrylic resin is, for example, preferably from 200,000 to 1,000,000, and more preferably from 200,000 to 800,000. By setting the weight-average molecular weight of the acrylic resin within the above range, sufficient initial adhesive strength can be exhibited.

[0089] Here, in this specification, the weight-average molecular weight is a polystyrene-equivalent value measured by gel permeation chromatography (GPC). The weight-average molecular weight is measured, for example, using a measuring device HLC-8220GPC manufactured by Tosoh Corporation, a column TSKGEL-SUPERMULTIPORE-HZ-M manufactured by Tosoh Corporation, THF as a solvent, and standard polystyrenes with molecular weights of 1050, 5970, 18100, 37900, 96400, and 706000 as standards.

[0090] Furthermore, when the acrylic resin is a (meth)acrylic acid ester copolymer of a hydroxyl group-containing monomer copolymerizable with a (meth)acrylic acid ester and a carboxyl group-containing monomer, the mass ratio of the hydroxyl group-containing monomer to the carboxyl group-containing monomer is, for example, preferably 51:49 to 100:0, and more preferably 75:25 to 100:0. When the mass ratio of the monomers is within the above range, effective reduction in adhesive strength due to energy ray irradiation can be expected, and the occurrence of adhesive residue can be suppressed.

[0091] The acrylic resin may be energy ray-curable, for example, may have an energy ray-curable functional group in a side chain. The energy ray-curable functional group preferably has, for example, an ethylenically unsaturated bond, and specific examples thereof include a (meth)acryloyl group, a vinyl group, and an allyl group.

[0092] (b) Energy ray curable compound The energy ray-curable compound is not particularly limited as long as it is polymerizable upon irradiation with energy rays, and examples thereof include compounds having an energy ray-curable functional group.

[0093] Examples of energy ray-curable compounds include energy ray-curable monomers, energy ray-curable oligomers, and energy ray-curable polymers. The energy ray-curable polymers are polymers different from the resins (adhesive bases) described above. Among them, energy ray-curable oligomers are preferred from the viewpoint of the balance of adhesive strength before and after energy ray irradiation. Furthermore, energy ray-curable monomers, energy ray-curable oligomers, and energy ray-curable polymers may be used in combination. For example, when an energy ray-curable monomer is used in addition to an energy ray-curable oligomer, the adhesive layer is cured by three-dimensional crosslinking upon irradiation with energy rays, thereby reducing adhesive strength and increasing cohesive strength to prevent transfer to the chip side.

[0094] Examples of the energy ray-curable compound include radically polymerizable compounds, cationically polymerizable compounds, and anionically polymerizable compounds. Among these, radically polymerizable compounds are preferred. They have a high curing rate, can be selected from a wide variety of compounds, and can easily control physical properties such as adhesive strength before and after energy ray irradiation.

[0095] In addition, the adhesive strength after the energy ray irradiation can be controlled by adjusting the number of energy ray-curable functional groups in the energy ray-curable compound. As described above, for example, as the number of energy ray-curable functional groups increases, the crosslink density of the adhesive layer after the energy ray irradiation increases, and the adhesive strength after the energy ray irradiation tends to decrease.

[0096] In the energy ray-curable compound, the number of energy ray-curable functional groups per molecule is preferably 2 or more, more preferably 3 or more, and even more preferably 4 or more. If the number of energy ray-curable functional groups is within the above range, the crosslinking density of the adhesive layer after energy ray irradiation is sufficient, thereby achieving the desired peelability. In addition, the occurrence of adhesive residue due to a decrease in cohesive force can be suppressed. In addition, the upper limit of the number of energy ray-curable functional groups is not particularly limited.

[0097] The energy ray-curable compound is preferably a radical polymerizable oligomer, more preferably a radical polymerizable polyfunctional oligomer, such as those disclosed in JP 2012-31316 A.

[0098] In addition, as the energy ray-curable compound, a radical polymerizable oligomer or a radical polymerizable monomer may be used, and in particular, a radical polymerizable polyfunctional oligomer or a radical polymerizable polyfunctional monomer may be used. Examples of the radical polymerizable monomer include those disclosed in JP 2010-173091 A.

[0099] Examples of the energy ray curable compound include (meth)acrylate monomers, (meth)acrylate oligomers, (meth)acrylate polymers, etc. Examples of the energy ray curable compound that can be used include urethane (meth)acrylate, polyester (meth)acrylate, and epoxy (meth)acrylate.

[0100] Commercially available energy ray-curable compounds may also be used. For example, Mitsubishi Chemical Corporation's urethane acrylate "Shikou UV7620EA (molecular weight: 4100)" and Negami Chemical Industrial Co., Ltd.'s urethane acrylates "Art Resin UN-905 (molecular weight: 50,000 to 210,000)," "Art Resin UN-905DU1 (molecular weight: 26,000)," "Art Resin UN-951SC (molecular weight: 12,500)," "Art Resin UN-952 (molecular weight: 6,500 to 9,500)," "Art Resin UN-953 (molecular weight: 14,000 to 40,000)," "Art Resin UN-954 (molecular weight: 4,200)," and "Art Resin H-219 (molecular weight: 14,000 to 40,000)" are available. Examples of suitable polymers include "Art Resin H-315M (molecular weight: 6600)" and "Art Resin H-417M (molecular weight: 4000)" manufactured by Taisei Fine Chemical Co., Ltd., "8BR-600 (molecular weight: 100000)" acrylic urethane polymer manufactured by Taisei Fine Chemical Co., Ltd., "Unidic V-6850" polymer acrylate manufactured by DIC Corporation, "SMP-250AP (molecular weight: 20000-30000)" and "SMP-360A (molecular weight: 20000-30000)" acrylic polymer manufactured by Kyoeisha Chemical Co., Ltd., and "HA7975" acrylic resin acrylate manufactured by Showa Denko Materials Co., Ltd.

[0101] The energy ray-curable compounds may be used alone or in combination of two or more.

[0102] The weight-average molecular weight of the energy ray-curable compound is not particularly limited, but is preferably 30,000 or less, more preferably 10,000 or less, and even more preferably 8,000 or less. If the weight-average molecular weight of the energy ray-curable compound is within the above range, it exhibits sufficient compatibility with the acrylic resin (main adhesive agent), and the adhesive layer exhibits the desired adhesive strength before energy ray irradiation, and after energy ray irradiation, the occurrence of adhesive residue is suppressed and it can be easily peeled off. On the other hand, the weight-average molecular weight of the energy ray-curable resin composition is, for example, 500 or more.

[0103] Furthermore, the adhesive strength after irradiation with energy rays can be controlled by adjusting the content of the energy ray-curable compound. If the content of the energy ray-curable compound is high, the adhesive strength after irradiation with energy rays tends to be low.

[0104] The content of the energy ray-curable compound is, for example, preferably 5 to 150 parts by mass, more preferably 20 to 100 parts by mass, and even more preferably 50 to 80 parts by mass, per 100 parts by mass of the resin (main adhesive agent). If the content of the energy ray-curable compound is within the above range, the crosslink density of the adhesive layer after energy ray irradiation is sufficient, thereby achieving the desired peelability. In addition, the occurrence of adhesive residue due to a decrease in cohesive force can be suppressed.

[0105] (c) Polymerization initiator The adhesive layer may contain a polymerization initiator in addition to the resin (main adhesive agent) and the energy ray-curable compound.

[0106] As the polymerization initiator, a general photopolymerization initiator can be used. Specific examples include acetophenones, benzophenones, α-hydroxyketones, benzyl methyl ketals, α-aminoketones, and bisacylphosphine oxides. When a urethane acrylate is used as the energy ray-curable compound, the polymerization initiator is preferably a bisacylphosphine-based polymerization initiator. Because this polymerization initiator has heat resistance, it can reliably cure the energy ray-curable compound even when the adhesive layer is irradiated with energy rays through a porous substrate.

[0107] The polymerization initiator preferably has absorption at wavelengths of 230 nm or more, and preferably at wavelengths of 300 nm to 400 nm. Such polymerization initiators can absorb energy rays with a wide wavelength range of 300 nm or more and efficiently generate active species that induce a polymerization reaction of the energy ray-curable compound. Therefore, even with a small amount of energy ray irradiation, the energy ray-curable compound can be efficiently cured and easily peeled off. Furthermore, as described above, resins and the like can be used for the porous substrate, and many resins absorb energy rays with wavelengths up to about 300 nm but transmit energy rays with wavelengths of about 300 nm or more. Furthermore, in recent years, LED lamps with wavelengths of 300 nm or more are often used in energy ray irradiation devices. Therefore, by using a polymerization initiator with absorption at wavelengths of 230 nm or more, the energy ray-curable compound can be cured using the energy rays that have transmitted through the porous substrate.

[0108] The content of the polymerization initiator is, for example, preferably 0.01 to 10 parts by mass, more preferably 0.5 to 6 parts by mass, per 100 parts by mass of the total of the resin (main adhesive agent) and the energy ray-curable compound. If the content of the polymerization initiator is below the above range, the polymerization reaction of the energy ray-curable compound may not occur sufficiently, resulting in excessively high adhesive strength of the adhesive layer after energy ray irradiation and inability to achieve peelability. On the other hand, if the content of the polymerization initiator exceeds the above range, the energy ray may only reach the vicinity of the energy ray-irradiated surface, resulting in insufficient curing of the adhesive layer. Furthermore, the cohesive force may decrease, which may cause adhesive residue.

[0109] (d) Crosslinking agent The adhesive layer may contain a crosslinking agent in addition to the resin (main adhesive agent) and the energy ray-curable compound.

[0110] The crosslinking agent is not particularly limited as long as it crosslinks at least between resins (main adhesive agents), and is appropriately selected depending on the type of resin (main adhesive agent), etc. Examples include isocyanate-based crosslinking agents, epoxy-based crosslinking agents, and metal chelate-based crosslinking agents. Specific examples of isocyanate-based crosslinking agents and epoxy-based crosslinking agents include those disclosed in JP 2012-31316 A. The crosslinking agents can be used alone or in combination of two or more.

[0111] The content of the crosslinking agent is appropriately set depending on the type of crosslinking agent, and is, for example, preferably 0.01 to 15 parts by mass, more preferably 0.01 to 10 parts by mass, per 100 parts by mass of the resin (main adhesive). If the content of the crosslinking agent is below the above range, the adhesion may be poor, or the adhesive layer may undergo cohesive failure when peeling the chip, resulting in adhesive residue. On the other hand, if the content of the crosslinking agent exceeds the above range, the crosslinking agent may remain in the adhesive layer as unreacted monomer after energy ray irradiation, which may reduce cohesive strength and cause adhesive residue.

[0112] (e) Additives The adhesive layer may contain various additives as needed, such as a tackifier, an antistatic agent, a plasticizer, a silane coupling agent, a metal chelating agent, a surfactant, an antioxidant, an ultraviolet absorber, a colorant, a preservative, an antifoaming agent, and a wettability adjuster.

[0113] (f) Other The energy ray-curable adhesive layer can be formed, for example, by applying an adhesive composition onto a separator. After the adhesive layer is formed, a porous substrate is placed on the adhesive layer to obtain an adhesive tape for processing electronic components, which has the porous substrate, the adhesive layer, and the separator in this order.

[0114] (2) Slightly adhesive adhesive layer The weak adhesive layer is an adhesive layer that exhibits weak adhesion. Although the weak adhesive layer has low initial adhesive strength, it can sufficiently fix the substrate and chip to the adhesive tape for electronic component processing during the dicing process. Furthermore, because the initial adhesive strength is low, it has excellent removability, and during the peeling process, the chip can be easily peeled from the adhesive tape for electronic component processing.

[0115] Here, when a low-adhesion adhesive layer exhibits low adhesion, it means that the adhesive layer exhibits adhesive strength sufficient to sufficiently fix the substrate to be processed and the chip to the adhesive tape for electronic component processing during the dicing process, and sufficient adhesive strength sufficient to easily peel the chip from the adhesive tape for electronic component processing during the peeling process.

[0116] The weak adhesive layer is not particularly limited as long as it satisfies the adhesive properties described below. In particular, the weak adhesive layer preferably contains at least an acrylic resin, and more preferably contains an acrylic resin and a crosslinking agent.

[0117] Here, when the low-tack adhesive layer contains an acrylic resin, it means that the acrylic resin may exist in the low-tack adhesive layer as a single entity without forming crosslinks, or as a crosslinked entity formed by crosslinking between acrylic resins or between acrylic resins and other resins, or both the single entity and the crosslinked entity may be present.

[0118] Here, the adhesive layer containing an acrylic resin means that the acrylic resin may exist in the adhesive layer as a single entity without forming crosslinks, or as a crosslinked entity formed by crosslinking between acrylic resins or between an acrylic resin and another resin, or both the single entity and the crosslinked entity may be present.

[0119] (a) Acrylic resin The acrylic resin is not particularly limited, and examples thereof include a (meth)acrylic acid ester polymer obtained by homopolymerizing a (meth)acrylic acid ester, and a (meth)acrylic acid ester copolymer obtained by copolymerizing a (meth)acrylic acid ester as a main component with a (meth)acrylic acid ester and other monomers. Among these, a (meth)acrylic acid ester copolymer is preferred.

[0120] Here, in a (meth)acrylic acid ester copolymer, "having a (meth)acrylic acid ester as the main component" means that the proportion of the (meth)acrylic acid ester relative to other monomers in the copolymer is greater than 30% by mass, and specifically means that the copolymerization proportion is 51% by mass or more.

[0121] In this specification, (meth)acrylic acid refers to at least one of acrylic acid and methacrylic acid.

[0122] Examples of (meth)acrylic acid esters that can be used include (meth)acrylic acid alkyl esters such as linear or branched alkyl esters having from 1 to 30 carbon atoms, and (meth)acrylic acid cycloalkyl esters. Specific examples of (meth)acrylic acid alkyl esters include those disclosed in JP 2014-101457 A. One or more types of (meth)acrylic acid esters may be used. Of these, (meth)acrylic acid esters having from 1 to 18 carbon atoms, and particularly from 1 to 8 carbon atoms, are preferred. The glass transition temperature of the acrylic resin is likely to fall within the range described below, which can improve the adhesiveness of the adhesive layer.

[0123] The acrylic resin may be a copolymer of a (meth)acrylic acid ester and a monomer or oligomer. In addition to the (meth)acrylic acid ester, other monomers or oligomers may be included as copolymerization components, if necessary, to improve properties such as cohesive strength and heat resistance. Examples of the copolymerization component include functional group-containing (meth)acrylates copolymerizable with the (meth)acrylic acid ester. Specific examples include carboxyl group-containing monomers, acid anhydride group-containing monomers, hydroxyl group-containing monomers, sulfonic acid group-containing monomers, phosphate group-containing monomers, epoxy group-containing monomers, vinyl esters, vinyl ethers, and aromatic vinyl compounds. Nitrogen-containing monomers such as cyano group-containing monomers, amide group-containing monomers, amino group-containing monomers, and isocyanate group-containing monomers may also be used as copolymerization components. The copolymerization component may be included in an acrylic acid ester polymer as a copolymerization component.

[0124] The weight-average molecular weight of the acrylic resin is, for example, preferably 100,000 or more and 2,000,000 or less, more preferably 200,000 or more and 1,000,000 or less, and even more preferably 400,000 or more and 800,000 or less. If the weight-average molecular weight is smaller than the above range, adhesive residue may occur in the adhesive layer. On the other hand, if the weight-average molecular weight is larger than the above range, the adhesive strength may increase and the peelability may decrease.

[0125] The glass transition temperature of the acrylic resin is, for example, preferably −100° C. or higher and 0° C. or lower, and more preferably −80° C. or higher and −20° C. or lower. By using an acrylic resin having a glass transition temperature within the above range as the main component, desired adhesive properties can be easily obtained.

[0126] The glass transition temperature of an acrylic resin can be adjusted appropriately by changing the type of monomer unit used, the ratio of the monomer units to be combined, etc. Even in the case of an acrylic resin in the form of a polymer (homopolymer) obtained by homopolymerizing a monomer, the glass transition temperature may be within the above range. However, the use of a monomer unit whose homopolymer glass transition temperature is not within the above range is not restricted. It is sufficient that the glass transition temperature of a copolymer obtained by copolymerizing a combination of various monomer units is within the above range.

[0127] In this specification, the glass transition temperature refers to a value measured by a method (DMA method) based on the peak-top value of the loss tangent (tan δ). The loss tangent is determined by the value of loss modulus / storage modulus. These moduli are measured using a dynamic viscoelasticity measuring device to measure the stress when a force is applied to a polymer or copolymer at a certain frequency.

[0128] The acrylic resin can be obtained by polymerizing a monomer such as the above-mentioned (meth)acrylic acid ester, monomer, or oligomer by a conventional method such as solution polymerization, bulk polymerization, emulsion polymerization, or suspension polymerization.

[0129] (b) Crosslinking agent The crosslinking agent may be any common crosslinking agent capable of crosslinking the acrylic resin, such as an epoxy crosslinking agent, an isocyanate crosslinking agent, a metal chelate crosslinking agent, or a carbodiimide crosslinking agent.

[0130] The content of the crosslinking agent is, for example, 0.1 to 20 parts by mass, preferably 0.3 to 10 parts by mass, relative to 100 parts by mass of the acrylic resin. When the content of the crosslinking agent is within the above range, desired adhesive properties can be easily obtained.

[0131] (c) Other ingredients The adhesive layer may contain any additives, such as a lubricant, a plasticizer, a bulking agent, an antistatic agent, an antiblocking agent, a light stabilizer, a colorant, etc., as needed.

[0132] (d) Other The method for forming the weakly adhesive layer is the same as the method for forming the energy ray curable adhesive layer.

[0133] (3) Thickness of adhesive layer The thickness of the adhesive layer may be any thickness that provides the desired adhesive strength, and may be, for example, 10 μm or more, 25 μm or more, or 50 μm or more. The surface of the porous substrate has irregularities due to openings and non-openings. Having a thickness of the adhesive layer equal to or greater than a predetermined value improves adhesion between the adhesive sheet for electronic components and the substrate or chip to be processed, thereby suppressing chipping during water jet laser processing. Furthermore, having a thickness of the adhesive layer equal to or greater than a predetermined value ensures sufficient adhesion to the porous substrate. In the case of an energy ray-curable adhesive layer, having a thickness of the adhesive layer equal to or greater than a predetermined value can prevent poor curing due to oxygen inhibition from the surface of the adhesive layer facing the porous substrate. On the other hand, the thickness of the adhesive layer is, for example, 200 μm or less. Having a thickness of the adhesive layer equal to or less than a predetermined value ensures sufficient water permeability.

[0134] As illustrated in Figure 3, the thickness t of the adhesive layer 2 is the length from the reference plane s to the outermost surface of the adhesive layer 2 on the porous substrate 1 side, when the outermost surface of the porous substrate 1 on the adhesive layer 2 side is taken as the reference plane s.

[0135] 3. Other configurations The pressure-sensitive adhesive tape for processing electronic components according to the present disclosure may have other components as needed in addition to the porous substrate and pressure-sensitive adhesive layer described above.

[0136] The pressure-sensitive adhesive tape for processing electronic components according to the present disclosure may have a separator on the surface of the pressure-sensitive adhesive layer opposite to the porous substrate.

[0137] 4. Characteristics of adhesive tape for electronic component processing (1) Energy ray curable adhesive layer When the adhesive layer is an energy ray-curable adhesive layer, the peel strength between the porous substrate and the adhesive layer after irradiation with energy rays is preferably equal to or greater than the adhesive strength to the glass substrate after irradiation with energy rays, thereby preventing adhesive residue on the adherend.

[0138] When the adhesive layer is an energy ray-curable adhesive layer, the adhesive strength of the adhesive tape for electronic component processing to a glass plate before energy ray irradiation may be, for example, 0.5 N / 25 mm or more and 40 N / 25 mm or less. Furthermore, the adhesive strength to a glass plate after energy ray irradiation is preferably, for example, 2.0 N / 25 mm or less. The lower limit of the adhesive strength to a glass plate after energy ray irradiation is not particularly limited, and is, for example, 0.01 N / 25 mm or more.

[0139] The adhesive strength to the glass plate is measured according to Method 1 of JIS Z0237:2022 (Test Methods for Adhesive Tapes and Sheets) (a test method in which the tape or sheet is peeled off at an angle of 180° from the stainless steel test plate at a temperature of 23°C and humidity of 50%), by peeling the test piece lengthwise at a width of 25 mm, a peel angle of 180°, and a peel speed of 300 mm / min. The glass plate used is float glass (150 mm x 70 mm, 2 mm thick) manufactured by Osaka Glass Industry Co., Ltd.

[0140] When the adhesive layer is an energy ray-curable adhesive layer, the peel strength between the porous substrate and the adhesive layer in the adhesive tape for electronic component processing after energy ray irradiation is, for example, equal to or greater than the adhesive strength to a glass plate after the above-mentioned energy ray irradiation, and may be at least twice the adhesive strength to a glass plate after the above-mentioned energy ray irradiation. When the peel strength is within the above range, the adhesion between the porous substrate and the adhesive layer after energy ray irradiation is high, thereby suppressing adhesive residue on the adherend. On the other hand, the upper limit of the peel strength is not particularly limited. For example, when the peel strength between the porous substrate and the adhesive layer after energy ray irradiation is very high, in the method for measuring the peel strength between the porous substrate and the adhesive layer after energy ray irradiation described below, the peel strength between the porous substrate and the adhesive layer may be equal to or greater than the peel strength between the adhesive tape for electronic component processing and the adherend, and peeling may not occur between the porous substrate and the adhesive layer.

[0141] Here, the peel strength between the porous substrate and the adhesive layer after energy beam irradiation is measured by a T-peel test. Specifically, first, an adhesive tape for electronic component processing is prepared, which has a porous substrate, an adhesive layer, and a separator in this order. At this time, if a separator is not arranged on the adhesive layer of the adhesive tape for electronic component processing on the side opposite the porous substrate, a separator is arranged on the adhesive layer on the side opposite the porous substrate. Next, the adhesive layer of the adhesive tape for electronic component processing is irradiated with energy beams to harden it. For example, energy beams are irradiated from the side of the adhesive tape for electronic component processing facing the porous substrate. Next, the separator is peeled from the adhesive tape for electronic component processing to expose the adhesive layer. Next, an adherend (polyester adhesive tape No. 31B manufactured by Nitto Denko Corporation) is bonded to the adhesive layer of the adhesive tape for electronic component processing (one reciprocating motion) using a 2 kg roller, and cut to a width of 25 mm. After that, the adhesive tape is aged for 6 hours to prepare a test specimen. Next, the porous substrate and adhesive layer of the test specimen were forcibly peeled along the length of the specimen. The edges of the peeled portion between the porous substrate and adhesive layer were clamped with the gripping tools of a tensile tester. A T-peel test was performed at a peel rate of 300 mm / min and a peel distance of 50 mm to measure the peel strength between the porous substrate and adhesive layer after energy beam irradiation. The measurement environment was a temperature of 23°C and a humidity of 50% RH. A Tensilon RTF1150 manufactured by A&D Corporation, for example, could be used as the tensile tester.

[0142] Examples of means for controlling the peel force between the porous substrate and the adhesive layer after irradiation with energy rays include a method of adjusting the aperture ratio of the porous substrate, a method of adjusting the diameter of the thread when the porous substrate is a woven fabric, a method of subjecting the porous substrate to a surface treatment, a method of adjusting the thickness of the adhesive layer, a method of adjusting the components or composition contained in the adhesive layer, and a method of adjusting the aging temperature when forming the adhesive layer or when laminating the porous substrate and the adhesive layer.

[0143] In a method for adjusting the opening ratio of a porous substrate, for example, when the thickness of the adhesive layer is constant, the smaller the opening ratio of the porous substrate, the larger the contact area between the resin film and the adhesive layer, which tends to improve the adhesion between the porous substrate and the adhesive layer and increase the peel force.

[0144] When the porous substrate is a woven fabric, in a method of adjusting the diameter of the thread, for example, when the thickness of the adhesive layer is constant, a smaller average diameter of the thread increases the contact area between the porous substrate and the adhesive layer, thereby improving the adhesion between the porous substrate and the adhesive layer and tending to increase the peel force.

[0145] In the method of subjecting the porous substrate to a surface treatment, for example, the peel force can be increased by subjecting the porous substrate to a surface treatment.

[0146] In the method of adjusting the thickness of the adhesive layer, the thicker the adhesive layer, the larger the contact area between the porous substrate and the adhesive layer, which improves the adhesion between the porous substrate and the adhesive layer and tends to increase the peel force.

[0147] Specific methods for adjusting the components and composition contained in the adhesive layer include a method for adjusting the content, number of functional groups, and molecular weight of the energy ray-curable compound, and a method for adding a tackifier. For example, when the content of the energy ray-curable compound is low, the peel force tends to be high, while when the content of the energy ray-curable compound is high, the peel force tends to be low. For example, when the number of energy ray-curable functional groups in the energy ray-curable compound is low, the peel force tends to be high, while when the number of energy ray-curable functional groups in the energy ray-curable compound is high, the peel force tends to be low. For example, when the molecular weight of the energy ray-curable compound is low, the peel force tends to be high, while when the molecular weight of the energy ray-curable compound is high, the peel force tends to be low. For example, when a tackifier is added, the peel force tends to be high.

[0148] In a method of adjusting the aging temperature during formation of the adhesive layer or during lamination of the porous substrate and adhesive layer, for example, if the aging temperature is high, the peel force tends to be large, whereas if the aging temperature is low, the peel force tends to be small.

[0149] (2) Slightly adhesive adhesive layer When the adhesive layer is a weak adhesive layer, the peel strength between the porous substrate and the adhesive layer is preferably equal to or greater than the adhesive strength to the glass substrate, thereby preventing adhesive residue on the adherend.

[0150] When the adhesive layer is a weak adhesive layer, the adhesive strength of the adhesive tape for electronic component processing to a glass plate is 6.0 N / 25 mm or less, or may be 3.0 N / 25 mm or less, or may be 0.5 N / 25 mm or less, while the adhesive strength to a glass plate is, for example, 0.05 N / 25 mm or more.

[0151] Here, the method for measuring the adhesive strength to the glass plate is the same as the method for measuring the adhesive strength to the glass plate in the case of the energy ray curable adhesive layer.

[0152] When the adhesive layer is a weak adhesive layer, the peel strength between the porous substrate and the adhesive layer in the adhesive tape for electronic component processing is, for example, equal to or greater than the adhesive strength to the glass plate after the above-mentioned energy ray irradiation, and may be at least twice the adhesive strength to the glass plate after the above-mentioned energy ray irradiation. When the peel strength is within the above range, the adhesion between the porous substrate and the adhesive layer is high, thereby suppressing adhesive residue on the adherend. On the other hand, the upper limit of the peel strength is not particularly limited. For example, when the peel strength between the porous substrate and the adhesive layer after energy ray irradiation is very large, in the method for measuring the peel strength between the porous substrate and the adhesive layer after energy ray irradiation described below, the peel strength between the porous substrate and the adhesive layer may be equal to or greater than the peel strength between the adhesive tape for electronic component processing and the adherend, and the porous substrate and the adhesive layer may not peel.

[0153] The peel strength between the porous substrate and the adhesive layer is measured using a T-peel test. Specifically, an adherend (Nitto Denko Corporation's polyester adhesive tape No. 31B) is first bonded to the adhesive layer of an electronic component processing adhesive tape using a 2 kg roller (one round trip), and then cut to a width of 25 mm. This is then aged for 6 hours to prepare a test specimen. Next, the porous substrate and adhesive layer of the test specimen are forcibly peeled along the length of the specimen. The edges of the peeled portion between the porous substrate and adhesive layer of the test specimen are clamped with the gripping tools of a tensile tester, and a T-peel test is performed at a peel speed of 300 mm / min and a peel distance of 50 mm to measure the peel strength between the porous substrate and adhesive layer after energy beam irradiation. The measurement environment is a temperature of 23°C and a humidity of 50% RH. A Tensilon RTF1150 manufactured by A&D Corporation, for example, can be used as a tensile tester.

[0154] Examples of means for controlling the peel force between the porous substrate and the adhesive layer include adjusting the aperture ratio of the porous substrate, adjusting the diameter of the thread when the porous substrate is a woven fabric, applying a surface treatment to the porous substrate, adjusting the thickness of the adhesive layer, adjusting the components and composition contained in the adhesive layer, and adjusting the aging temperature when forming the adhesive layer or when laminating the porous substrate and adhesive layer.

[0155] The methods for adjusting the opening ratio of the porous substrate, adjusting the diameter of the thread when the porous substrate is a woven fabric, applying a surface treatment to the porous substrate, adjusting the thickness of the adhesive layer, and adjusting the aging temperature when forming the adhesive layer or laminating the porous substrate and adhesive layer are the same as those for the energy ray-curable adhesive layer described above.

[0156] Furthermore, a specific example of a method for adjusting the components and composition contained in the adhesive layer is to add a tackifier. For example, adding a tackifier tends to increase the peel strength.

[0157] 5.Applications The adhesive tape for electronic component processing according to the present disclosure can be used as a dicing tape. In particular, the adhesive tape for electronic component processing according to the present disclosure can be suitably used as a dicing tape when dicing a workpiece substrate by laser processing. In particular, the adhesive tape for electronic component processing according to the present disclosure can be suitably used as a dicing tape when dicing a workpiece substrate by water jet laser processing.

[0158] B. Manufacturing methods for electronic components The method for manufacturing electronic components in the present disclosure includes an attachment step of attaching the above-mentioned adhesive tape for electronic component processing to one side of a workpiece substrate, a dicing step of dividing the workpiece substrate into a plurality of chips, and a peeling step of peeling the adhesive tape for electronic component processing from the chips.

[0159] 4(a) to 4(e) are process diagrams illustrating an example of a method for manufacturing an electronic component according to the present disclosure. First, as shown in FIG. 4(a), a bonding step is performed in which the adhesive layer surface of the adhesive tape 10 for electronic component processing is bonded to a ring frame 21, and then a substrate 11 to be processed is bonded to the adhesive layer surface of the adhesive tape 10 for electronic component processing. Next, as shown in FIG. 4(b), a dicing step is performed in which the substrate 11 is divided into chips 12. Next, when the adhesive layer of the adhesive tape 10 for electronic component processing is an energy ray-curable adhesive layer, as shown in FIG. 4(c), an irradiation step is performed in which the adhesive layer of the adhesive tape 10 for electronic component processing is irradiated with energy rays 25 from the porous substrate side to harden and reduce the adhesive strength. Next, as shown in FIG. 4(d), a pick-up step is performed in which the chip 12 is peeled from the adhesive tape 10 for electronic component processing and picked up. This pick-up step is a peeling step. Next, as shown in FIG. 4(e), a mounting (die bonding) step is performed in which the picked-up chip 12 is bonded to a substrate 26.

[0160] 5(a) to 5(e) are process diagrams illustrating another example of a method for manufacturing electronic components according to the present disclosure. First, as shown in FIG. 5(a), a bonding step is performed in which the adhesive layer surface of the adhesive tape 10 for electronic component processing is bonded to a ring frame 21, and then a substrate 11 to be processed is bonded to the adhesive layer surface of the adhesive tape 10 for electronic component processing. Next, as shown in FIG. 5(b), a dicing step is performed in which the substrate 11 is divided into chips 12. Next, as shown in FIG. 5(c), a transfer tape 27 is bonded to the surface of the chip 12 opposite the adhesive tape 10 for electronic component processing. Thereafter, if the adhesive layer of the adhesive tape 10 for electronic component processing is an energy ray-curable adhesive layer, an irradiation step is performed in which the adhesive layer of the adhesive tape 10 for electronic component processing is irradiated with energy rays 25 from the porous substrate side to harden and thereby reduce its adhesive strength, as shown in FIG. 5(d). 5(e), a transfer step is performed in which the adhesive tape 10 for processing electronic components is peeled off from the chip 12 and the ring frame 21, and the chip 12 and the ring frame 21 are transferred to the transfer tape 40. This transfer step is the peeling step.

[0161] A general method can be applied to each step in the method for manufacturing an electronic component according to the present disclosure.

[0162] In the dicing step, the substrate is preferably divided into a plurality of chips by a laser guided by a water jet. The water jet laser processing conditions can be general conditions.

[0163] In the present disclosure, the use of the above-described pressure-sensitive adhesive tape for processing electronic components can prevent the porous substrate from being cut during water jet laser processing.

[0164] When the adhesive layer is an energy ray curable adhesive layer, an irradiation step is carried out after the dicing step and before the peeling step, in which the adhesive layer of the adhesive tape for processing electronic components is irradiated with energy rays to be cured.

[0165] The present disclosure is not limited to the above-described embodiments. The above-described embodiments are merely examples, and any configuration that is substantially identical to the technical idea described in the claims of the present disclosure and that provides similar effects is included within the technical scope of the present disclosure. [Example]

[0166] Hereinafter, the present disclosure will be further described with reference to examples and comparative examples.

[0167] [Manufacturing Example 1] A pressure-sensitive adhesive composition was prepared by diluting 100 parts by mass of the adhesive base (acrylic acid copolymer), 50 parts by mass of urethane acrylate (ultraviolet-curable compound, 9 functional groups, molecular weight 4100, active content 65%), 7.5 parts by mass of a photopolymerization initiator (IGM Resins BV "Omnirad 819"), and 3 parts by mass of a crosslinking agent (isocyanate-based curing agent (tolylene diisocyanate (TDI)-based adduct type (trimethylolpropane adduct)), solid content 75%) with a mixed solvent of toluene and methyl ethyl ketone (mass ratio 1:1) and thoroughly dispersing the mixture.

[0168] The above adhesive composition was applied to a polyethylene terephthalate (PET) separator (Nippa Corporation's "PET50x1-M-J2", thickness 50 μm) so that the thickness after drying would be 50 μm, and the composition was dried in an oven at 110°C for 3 minutes to form an adhesive layer.

[0169] The porous substrate used was a nylon mesh sheet shown in Table 1. In Table 1, the filler refers to titanium oxide particles. The porous substrate was laminated onto the adhesive layer, and then aged at 40°C for 3 days to produce an adhesive tape for processing electronic components.

[0170] [Manufacturing Examples 2 to 5] An adhesive tape for processing electronic parts was produced in the same manner as in Production Example 1, except that a nylon mesh sheet shown in Table 1 was used as the porous substrate.

[0171] [Manufacturing Examples 6 to 9] An adhesive tape for processing electronic parts was produced in the same manner as in Production Example 1, except that a nylon mesh sheet shown in Table 1 was used as the porous substrate.

[0172] [Manufacturing Examples 10-11] An adhesive tape for processing electronic parts was produced in the same manner as in Production Example 1, except that a polyester mesh sheet shown in Table 1 was used as the porous substrate.

[0173] [Manufacturing Example 12] An adhesive tape for processing electronic parts was produced in the same manner as in Production Example 1, except that a polypropylene mesh sheet shown in Table 1 was used as the porous substrate.

[0174] [Reference example 1] When the porous substrate was a woven fabric, nylon threads shown in Table 1 were prepared as threads used in the woven fabric. In this example, only the threads were evaluated, and therefore it was used as a reference example.

[0175] [evaluation] (1) Absorption coefficient The absorption coefficient of a given laser wavelength for the non-opening portion of the porous substrate was determined as described above in "A. Adhesive Tape for Electronic Component Processing 1. Porous Substrate (1) Characteristics of the Porous Substrate." The transmittance of a given laser wavelength for the porous substrate was measured using an integrating sphere with a Shimadzu UV-Visible Near-Infrared Spectrophotometer "UV2700i." The wire diameter was measured with a Keyence VHX-2000 Digital Microscope.

[0176] (2) Scratches Water jet laser processing was performed on adhesive tape for electronic component processing, and the presence or absence of scratches on the porous substrate was evaluated. First, as shown in Figure 6, adhesive tape for electronic component processing 10 was cut into 30 mm x 60 mm pieces. The adhesive tape for electronic component processing 10 was placed on a glass plate 51 with the porous substrate facing the glass plate and the adhesive layer facing outward, and then secured with Kapton tape 52 to obtain a processing laminate 50. Using a water jet laser processing dicing device (SYNOVA's "Laser Microjet"), 10 passes were made on the same location of the processing laminate 50 from the adhesive layer side, as indicated by the arrows in Figure 6, under conditions of a laser wavelength of 532 nm or 355 nm, a cutting speed of 100 mm / s, and a laser beam diameter (water jet diameter) of 50 μm. Using a Keyence Corporation "Digital Microscope VHX-2000," the porous substrate of the adhesive tape for electronic component processing after water jet laser processing was observed and evaluated for the presence or absence of scratches. The magnification was 200x, and the lighting method was transmitted light. Evaluation was based on the following criteria. Note that a laser mark is a thin mark that shows where the laser passed, and does not appear to have been gouged. On the other hand, a scratch refers to something that has been gouged, and includes a state where it is clearly gouged and about to break. A: No laser marks B: Laser marks but no scratches C: Scratched or cut

[0177] [Table 1]

[0178] When the laser wavelength was 532 nm, the porous substrate was prevented from being scratched by water jet laser processing when the absorption coefficient at 532 nm of the non-opening portion of the porous substrate was a predetermined value or less, as in Production Examples 1 to 5, 10, and 12. Furthermore, when the laser wavelength was 355 nm, the porous substrate was prevented from being scratched by water jet laser processing when the absorption coefficient at 355 nm of the non-opening portion of the porous substrate was a predetermined value or less, as in Production Examples 1 to 5, and 12.

[0179] The present disclosure provides the following inventions. [1] An adhesive tape for processing electronic components, comprising a porous substrate and an adhesive layer disposed on a first surface of the porous substrate, The extinction coefficient of the non-opening portion of the porous substrate at the wavelength of the predetermined laser is 30 cm -1 The following is an adhesive tape for processing electronic components. [2] The adhesive tape for processing electronic components according to [1], wherein the wavelength of the laser is 532 nm or 355 nm. [3] The adhesive tape for processing electronic components according to [1] or [2], wherein the porous substrate is a woven fabric. [4] The adhesive tape for processing electronic components according to [3], wherein the yarn constituting the woven fabric is a monofilament. [5] a step of attaching the adhesive tape for electronic component processing according to any one of [1] to [4] to a first surface of a substrate to be processed; a dicing step of dividing the substrate into a plurality of chips; a peeling step of peeling the adhesive tape for processing electronic components from the chip; The method for manufacturing an electronic component includes the steps of: [6] The method for manufacturing an electronic component according to [5], wherein the dicing step divides the substrate to be processed into a plurality of chips using a laser guided by a water jet. [Explanation of symbols]

[0180] 1 … Porous base material 2 … Adhesive layer 10...Adhesive tape for electronic component processing

Claims

1. An adhesive tape for processing electronic components, comprising a porous substrate and an adhesive layer disposed on a first surface of the porous substrate, The extinction coefficient of the non-opening portion of the porous substrate at the wavelength of the predetermined laser is 30 cm －１ The following is an adhesive tape for processing electronic components.

2. 2. The adhesive tape for processing electronic components according to claim 1, wherein the wavelength of the laser is 532 nm or 355 nm.

3. The adhesive tape for processing electronic components according to claim 1 , wherein the porous substrate is a woven fabric.

4. 4. The adhesive tape for processing electronic parts according to claim 3, wherein the yarn constituting the woven fabric is a monofilament.

5. a bonding step of bonding the adhesive tape for electronic component processing according to any one of claims 1 to 4 to a first surface of a substrate to be processed; a dicing step of dividing the workpiece substrate into a plurality of chips; a peeling step of peeling the adhesive tape for electronic component processing from the chip; The method for manufacturing an electronic component includes the steps of:

6. The method for manufacturing an electronic component according to claim 5, wherein the dicing step divides the substrate into a plurality of chips by a laser guided by a water jet.

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