Adhesive tape for processing electronic components and method for manufacturing electronic components

Abstract

To provide an adhesive tape for processing electronic components, having a porous base material and capable of suppressing misalignment during dicing, and a method for manufacturing electronic components.SOLUTION: An adhesive tape 10 for processing electronic components has a first surface S1 and a second surface S2 facing the first surface, and includes: a porous base material 1 with air permeability in a surface direction; an adhesive layer 2 arranged in the first surface of the porous base material 1; and a resin layer 3 with an air blocking property arranged in the second surface of the porous base material 1.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 and chipping due to water splashing are likely to occur. Therefore, as described in Patent Documents 1 and 2, for example, porous substrates such as woven or nonwoven fabrics that are permeable to water are used as the substrate for the adhesive tape in water jet laser processing. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-117943 [Patent Document 2] Patent No. 4128843 Summary of the Invention [Problem to be solved by the invention]

[0006] The adhesive tape is attached to a ring frame, and the substrate to be processed is fixed onto the adhesive tape. In the dicing process, the substrate to be processed, which is fixed to the adhesive tape, is then sucked and fixed onto a suction table for processing.

[0007] The inventors of the present disclosure have discovered a new problem: although adhesive tapes having a porous substrate can suppress chipping and chip flying due to water splashing by allowing water to pass through the porous substrate, gaps may occur between the surface of the adhesive tape facing the porous substrate and the suction table, and air leakage from these gaps reduces the suction force of the suction table, causing misalignment during dicing. As described above, with the recent trend toward smaller, thinner, and more highly integrated chips, high accuracy is required for the accuracy of misalignment of the cutting position during dicing.

[0008] The present disclosure has been made in consideration of the above-mentioned situation, and its main object is to provide an adhesive tape for processing electronic components that has a porous substrate and is capable of suppressing misalignment during dicing. [Means for solving the problem]

[0009] One embodiment of the present disclosure provides an adhesive tape for processing electronic components, comprising: a porous substrate having a first surface and a second surface opposite to the first surface and having air permeability in the planar direction; an adhesive layer disposed on the first surface of the porous substrate; and a resin layer disposed on the second surface of the porous substrate and having air permeability.

[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 misalignment during dicing. [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 to 1C are process diagrams illustrating a dicing process using an adhesive tape for processing electronic components according to the present disclosure. [Figure 3] 1A to 1C are process diagrams illustrating a conventional dicing process using an adhesive tape. [Figure 4] 1A to 1C are process diagrams illustrating a dicing process using an adhesive tape for processing electronic components according to the present disclosure. [Figure 5] 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 6] 1 is a schematic cross-sectional view illustrating an example of an adhesive tape for processing electronic components according to the present disclosure. [Figure 7] 1A to 1C are process diagrams illustrating a method for manufacturing an electronic component according to the present disclosure. [Figure 8] 1A to 1C are process diagrams illustrating a method for manufacturing an electronic component according to the present disclosure. 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 terms "film" and "sheet" are not distinguished from each other solely based on the difference in name.

[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 comprises a porous substrate having a first surface and a second surface opposite to the first surface and having air permeability in the planar direction, an adhesive layer disposed on the first surface of the porous substrate, and a resin layer having air impermeability disposed on the second surface of the porous substrate.

[0018] Fig. 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, an adhesive tape 10 for electronic component processing comprises a porous substrate 1 having air permeability in the planar direction, an adhesive layer 2 disposed on a first surface S1 of the porous substrate 1, and an air-impermeable resin layer 3 disposed on a second surface S2 of the porous substrate 1. In Fig. 1, the porous substrate 1 is a woven fabric.

[0019] 2(a) and 2(b) are process diagrams illustrating an example of a dicing process using an adhesive tape for electronic component processing according to the present disclosure. First, as shown in FIG. 2(a), a ring frame 21 is attached to the adhesive layer 2 of the adhesive tape for electronic component processing 10, and a workpiece substrate 11 is attached to the adhesive layer of the adhesive tape for electronic component processing 10, thereby securing the workpiece substrate 11 to the adhesive tape for electronic component processing 10. Next, the workpiece substrate 11 secured to the adhesive tape for electronic component processing 10 is secured to a suction table 22 by vacuum suction. Next, as shown in FIG. 2(b), the workpiece substrate 11 is divided into chips 12.

[0020] FIG. 3 is a schematic cross-sectional view illustrating a case where a workpiece substrate is adsorbed and fixed to a suction table during a dicing process using a conventional adhesive tape having a porous substrate. As shown in FIG. 3, the adhesive tape 100 includes a porous substrate 101 and an adhesive layer 102. In FIG. 3, the porous substrate 101 is a woven fabric. When such an adhesive tape 100 is used, the surface of the woven porous substrate 101 is uneven, resulting in a gap between the surface of the adhesive tape 100 facing the porous substrate 101 and the suction table 22. Air leakage from this gap reduces the suction force of the suction table 22. This problem is not limited to when the porous substrate 101 is a woven fabric; a similar problem occurs when the porous substrate 101 has an uneven surface, such as when the porous substrate 101 is a fabric such as a woven fabric, nonwoven fabric, or knitted fabric. Furthermore, if the porous substrate 101 is breathable in the planar direction, air leaks from the edge of the porous substrate 101 or leaks from the cut portion 13 of the workpiece substrate 11 through the porous substrate 101, thereby reducing the suction force of the suction table 22. In this way, the inventors of the present disclosure discovered a new problem with conventional adhesive tapes having porous substrates: air leakage reduces the suction force of the suction table, causing misalignment during dicing.

[0021] FIG. 4 is a schematic cross-sectional view illustrating an example in which a workpiece substrate is adsorbed and fixed to a suction table during a dicing process using an adhesive tape for electronic component processing according to the present disclosure. In FIG. 4, the adhesive tape for electronic component processing 10 is the same as the adhesive tape for electronic component processing 10 shown in FIG. 1. In the adhesive tape for electronic component processing 10, a resin layer 3 is disposed on the second surface of the porous substrate 1. Therefore, if unevenness exists on the second surface of the porous substrate 1, the resin layer 3 can smooth out the unevenness. This prevents a gap from forming between the surface of the adhesive tape for electronic component processing 10 facing the resin layer 3 and the suction table 22. Furthermore, while the porous substrate 1 is breathable in the planar direction, the resin layer 3 is impermeable. Therefore, the resin layer 3 disposed on the second surface of the porous substrate 1 prevents air leakage from the end face of the porous substrate 1 and from the cut portion 13 of the workpiece substrate 11. This prevents a decrease in the suction force of the suction table due to air leakage, thereby preventing misalignment during dicing. Specifically, it prevents misalignment of the cutting position during dicing.

[0022] Therefore, the pressure-sensitive adhesive tape for electronic component processing according to 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 has air permeability in the planar direction and supports the adhesive layer.

[0025] (1) Characteristics of porous substrate (a) Breathability The porous substrate is breathable in the in-plane direction. The in-plane breathability of the porous substrate is confirmed by the following method. First, the porous substrate is cut into a size of 210 mm x 210 mm to obtain a test piece. The porous substrate is placed on the 200 mm diameter ceramic porous chuck table of a Harmotec tape remover "HTR0608-1." A 50 μm thick polyethylene terephthalate (PET) film is then placed on the porous substrate, and vacuum suction is initiated. During vacuum suction, a ULVAC vacuum pump "DA-20D" is used. While the vacuum is being drawn, the differential pressure between the inside of the ceramic porous chuck table and the atmosphere is measured using a dial-type differential pressure gauge attached to the device. If the differential pressure is -30 kPa or greater, the porous substrate is determined to be breathable in the in-plane direction.

[0026] In addition, the porous substrate is permeable to water, i.e., has water permeability. Therefore, the porous substrate is also breathable in the thickness direction. The breathability of the porous substrate in the thickness direction is confirmed by the following method. First, the porous substrate is cut into a size of 210 mm x 210 mm to obtain a test piece. The porous substrate is placed on the 200 mm diameter ceramic porous chuck table of the HTR0608-1 tape remover manufactured by Harmotec Corporation, and vacuum suction is initiated. During vacuum suction, the vacuum pump used is the DA-20D vacuum pump manufactured by ULVAC Corporation. While the vacuum is being drawn, the differential pressure between the inside of the ceramic porous chuck table and the atmosphere is measured using a dial-type differential pressure gauge attached to the device. If the differential pressure is -20 kPa or greater, the porous substrate is determined to be breathable in the thickness direction.

[0027] (b) Non-absorption of laser light The material of the porous substrate is preferably non-absorbent to laser light. By using a material that is non-absorbent to the laser light used in water jet laser processing, the porous substrate can be prevented from absorbing the laser light and generating heat. This can prevent the adhesive tape for electronic component processing from breaking during water jet laser processing, or prevent the porous substrate from becoming brittle during water jet laser processing.

[0028] "Non-absorbent to laser light" refers to being transparent to the wavelength of the laser light used in waterjet laser processing, or being reflective to the wavelength of the laser light used in waterjet laser processing. Specifically, when the region on the first surface of the porous substrate where pores are present is designated as the first region and the region without pores is designated as the second region, and the laser light transmittance of the second region of the porous substrate is designated as T1 (%), the transmittance of the second region of the porous substrate in the range of the laser light wavelength λ ± 20 nm is preferably within T1 ± 2.0%. When the transmission spectrum of the second region of the porous substrate is obtained based on the transmission spectrum of the entire porous substrate, if the transmittance in a predetermined wavelength range in the transmission spectrum of the second region of the porous substrate satisfies the above relationship, the porous substrate can be said to be non-absorbent to laser light, i.e., not have an absorption band at the wavelength of the laser light.

[0029] In particular, the material of the porous substrate is preferably transparent to the wavelength of the laser light used in water jet laser processing. The laser light transmittance T1 of the second region of the porous substrate is, for example, 50% or more, or may be 70% or more, or may be 90% or more.

[0030] The laser light transmittance T1 of the second region of the porous substrate is calculated by the following formula (1) using the laser light transmittance T2 of the porous substrate and the aperture ratio α of the porous substrate. T1 = (T2 - α) / (100 - α) × 100 (1)

[0031] The laser light transmittance T2 of the porous substrate is the laser light transmittance of the entire porous substrate.

[0032] The aperture ratio α (%) of the porous substrate is the sum of the areas of all pores in a measurement region on the first surface of the porous substrate, divided by the area of the entire measurement region. The area of all pores in the measurement region is measured by microscopic observation. If the aperture ratio of the porous substrate is known, this aperture ratio may be used. Furthermore, as described below, if the porous substrate is a woven fabric, the aperture ratio of the porous substrate is the aperture ratio of the woven fabric.

[0033] The laser light absorption and non-absorption properties of the porous substrate can be controlled, for example, by adjusting the material of the porous substrate.

[0034] When the material of the porous substrate is non-absorbent to laser light, the porous substrate may be colorless or colored.

[0035] Examples of wavelengths of laser light used in water jet laser processing include the 1064 nm wavelength of the fundamental wave of a YAG laser, the 532 nm wavelength of the second harmonic of a YAG laser, and the 355 nm wavelength of the third harmonic of a YAG laser. In recent years, in water jet laser processing, the use of laser light with a short wavelength has been considered to reduce the absorption rate in water and increase processing efficiency. Therefore, in the present disclosure, it is preferable to use laser light with a wavelength of 532 nm or 355 nm for non-absorbent or absorbent laser light.

[0036] (c) Energy ray transmittance As will be described later, when the adhesive layer is an energy ray-curable adhesive layer, the porous substrate preferably transmits energy rays. The energy ray transmittance of the porous substrate is, for example, 50% or more, or may be 70% or more, or may be 90% or more. When the energy transmittance of the porous substrate is high within the above range, reflection of energy rays by the porous substrate can be suppressed when the adhesive tape for electronic component processing is irradiated with energy rays from the resin layer side to cure the adhesive layer. This can suppress poor curing of the adhesive layer. On the other hand, there is no particular limitation on the upper limit of the energy transmittance of the porous substrate.

[0037] In this specification, the energy ray transmittance refers to the transmittance of the energy ray used when dicing a substrate to be processed using the adhesive tape for electronic component processing. For example, when ultraviolet light is used, and a high-pressure mercury lamp or a light source that reproduces the spectrum of a high-pressure mercury lamp is used, the dominant wavelength of the high-pressure mercury lamp is 365 nm. Therefore, in this case, the energy ray transmittance refers to the transmittance of a wavelength of 365 nm.

[0038] (2) Shape of porous substrate Examples of the porous substrate include woven fabrics, nonwoven fabrics, knitted fabrics, air bubble sheets, etc. Among these, woven fabrics are preferred from the viewpoint of strength.

[0039] (a) Textiles The woven material preferably has high transmittance to the laser light 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 may be used alone or in combination.

[0040] The weaving method of the woven fabric is not particularly limited, and examples thereof include plain weave, twill weave, and satin weave.

[0041] 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.

[0042] Figures 5(a) to 5(c) are schematic plan views and cross-sectional views illustrating an example of a woven fabric. Figure 5(b) is an enlarged view of Figure 5(a), and Figure 5(c) is a cross-sectional view of Figure 5(b). As shown in Figures 5(a) to 5(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 Figures 5(a) to 5(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.

[0043] The average diameter of the yarn is, for example, 100 μm or more, 110 μm or more, 120 μm or more, or 150 μm or more. The average diameter of the yarn is, for example, 1000 μm or less, 500 μm or less, 300 μm or less, or 200 μm or less. That is, the average diameter of the yarn is, for example, 100 μm or more and 1000 μm or less, 110 μm or more and 500 μm or less, 120 μm or more and 300 μm or less, or 150 μm or more and 200 μm or less. If the average diameter is too small, the porous substrate may be cut or weakened by the pressure of the water jet and the heat of the laser during water jet laser processing. On the other hand, if the average diameter is too large, water permeability may be impaired. When the yarn is a multifilament, the average diameter of the yarn refers to the average diameter of the multifilament.

[0044] Here, the average diameter of the 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 weft yarns are measured using a digital microscope. The digital microscope used can be the Keyence VHX-2000 Digital Microscope.

[0045] 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. If the opening rate is too small, water permeability may be impaired. On the other hand, if the opening rate is too large, adhesion to the adhesive layer may be reduced.

[0046] The opening rate B (%) of a woven fabric is expressed by the following formula. B=[C / (C+A)] 2 ×100 In the above formula, A is the average diameter of the yarn (μm), and C is the average opening between the yarns (μm).

[0047] 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 too small, water permeability may be impaired. On the other hand, if the average opening is too large, adhesion to the adhesive layer may be reduced.

[0048] The average inter-yarn shed is the arithmetic mean value of the shed between 10 randomly selected warp yarns and the shed between 10 randomly selected weft yarns. The shed between warp yarns and the shed between weft yarns are measured using a digital microscope. The digital microscope used can be Keyence's "Digital Microscope VHX-2000."

[0049] 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.

[0050] When the porous substrate is a woven fabric, the surface of the porous substrate 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.

[0051] When the porous substrate is a woven fabric, the thickness of the porous substrate is not particularly limited as long as it can support the adhesive layer. The thickness of the porous substrate is, for example, 100 μm or more, may be 110 μm or more, may be 120 μm or more, or may be 150 μm or more. The thickness of the porous substrate is, for example, 1000 μm or less, may be 500 μm or less, may be 300 μm or less, or may be 200 μm or less. That is, the thickness of the porous substrate is, for example, 100 μm or more and 1000 μm or less, may be 110 μm or more and 500 μm or less, may be 120 μm or more and 300 μm or less, or may be 150 μm or more and 200 μm or less.

[0052] 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 mean value of the thicknesses at 10 randomly selected locations is used.

[0053] When measuring the thickness of the porous substrate, the adhesive layer is removed from the adhesive tape for processing electronic components, and the porous substrate is taken out. The method for removing the adhesive layer is as described above.

[0054] (b) Non-woven fabric The material of the nonwoven fabric is the same as the material of the woven fabric described above. The method of manufacturing the nonwoven fabric is not particularly limited.

[0055] When the porous substrate is a nonwoven fabric, the surface of the porous substrate facing the adhesive layer may be subjected to a surface treatment in order to improve adhesion to the adhesive layer. The surface treatment is the same as that when the porous substrate is the woven fabric.

[0056] When the porous substrate is a nonwoven fabric, the thickness of the porous substrate is the same as when the porous substrate is the woven fabric described above.

[0057] (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.

[0058] 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.

[0059] The average diameter of the yarn is the same as that of the yarn of the woven fabric.

[0060] Here, the average diameter of the yarn is the arithmetic mean value of the diameters of 10 randomly selected yarns. The diameter of the yarn is measured using a digital microscope. The digital microscope that can be used is the "Digital Microscope VHX-2000" manufactured by Keyence Corporation.

[0061] 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.

[0062] When the porous substrate is a knitted fabric, the surface of the porous substrate facing the adhesive layer may be subjected to a surface treatment in order to improve adhesion to the adhesive layer. The surface treatment is the same as that when the porous substrate is a woven fabric.

[0063] When the porous substrate is a knitted fabric, the thickness of the porous substrate is similar to the thickness when the porous substrate is a woven fabric.

[0064] (4) Bubble sheets Since the bubble sheet has breathability in the plane direction, it is preferable that the bubble sheet has open cells in the plane direction. Also, since the bubble sheet has breathability in the thickness direction, it is preferable that the bubble sheet has open cells in the thickness direction.

[0065] The material of the bubble sheet preferably has a high transmittance to the laser light used in water jet laser processing.

[0066] 2. Resin layer The resin layer in the present disclosure is disposed on the second surface of the porous substrate and is air-impermeable.

[0067] (1) Resin layer characteristics (a) Non-breathable The resin layer is non-breathable. The non-breathability of the resin layer is confirmed by the following method. First, the resin layer is cut into a size of 210 mm x 210 mm to obtain a test piece. The resin layer is placed on the 200 mm diameter ceramic porous chuck table of a Harmotec tape remover "HTR0608-1," and vacuum suction is initiated. During vacuum suction, a ULVAC vacuum pump "DA-20D" is used. While the vacuum is being drawn, the differential pressure between the inside of the ceramic porous chuck table and the atmosphere is measured using a dial-type differential pressure gauge attached to the device. If the differential pressure is -75 kPa or less, the resin layer is determined to be non-breathable.

[0068] As described below, when the resin layer has an adhesive layer and a resin substrate in that order from the porous substrate side, the adhesive layer is arranged between the porous substrate and the resin substrate, and therefore the resin substrate may have breathability in the thickness direction.

[0069] (b) Flatness It is preferable that the surface of the resin layer opposite the porous substrate be flat. Because the porous substrate has air permeability in the planar direction, unevenness tends to exist on the first and second surfaces of the porous substrate. By disposing a resin layer on the second surface of the porous substrate, the unevenness on the second surface of the porous substrate can be smoothed out. Therefore, during the dicing process, the occurrence of a gap between the resin layer side of the adhesive tape for electronic component processing and the suction table can be suppressed. Therefore, the adhesive tape for electronic component processing attached to the substrate to be processed can be firmly fixed to the suction table, suppressing misalignment during dicing.

[0070] Specifically, the arithmetic mean roughness Ra of the resin layer on the surface opposite to the porous substrate is preferably 10 μm or less. For example, if Ra is within the above range, a matte-finished resin layer can be used. On the other hand, the surface of a woven fabric generally has irregularities, and the step height of these irregularities can be several hundred μm or more. Since such a woven fabric does not have a flat surface, it is difficult to vacuum-suck it onto a suction table.

[0071] The arithmetic mean roughness Ra is measured in accordance with JIS B0601:2013. The arithmetic mean roughness Ra is the average value of measurements taken at 10 arbitrary points.

[0072] (c) Peeling force The peel force between the porous substrate and the resin layer is, for example, preferably 2 N / 25 mm or more, may be 10 N / 25 mm or more, or may be 20 N / 25 mm or more. If the peel force is too small, the resin layer may be easily peeled off due to the pressure of the water jet during water jet laser processing. Furthermore, if there is a large gap between the porous substrate and the resin layer, the peel force tends to be small. If there is a large gap between the porous substrate and the resin layer, water may enter between the porous substrate and the resin layer during water jet laser processing, making the resin layer more likely to peel off. Therefore, by keeping the peel force within the above range, peeling of the resin layer due to the pressure of the water jet during water jet laser processing can be suppressed. Furthermore, if the peel force is within the above range, the gap between the porous substrate and the resin layer can be reduced. Therefore, water can be prevented from entering between the porous substrate and the resin layer during water jet laser processing, and peeling of the resin layer can be suppressed. Therefore, misalignment during the dicing process can be suppressed. On the other hand, the upper limit of the peel force between the porous substrate and the resin layer is not particularly limited. For example, if the peel force is very large, in the method for measuring the peel force between the porous substrate and the resin layer described below, for example, material destruction may occur, and peeling may not occur between the porous substrate and the resin layer.

[0073] The peel strength between the porous substrate and the resin layer is measured using a T-peel test. Specifically, an adhesive tape for electronic component processing is first prepared, which has a resin layer, a porous substrate, an adhesive layer, and a separator, in that order. If the adhesive tape for electronic component processing does not have a separator on the side of the adhesive layer opposite the porous substrate, a separator is placed on the side of the adhesive layer opposite the porous substrate. The adhesive tape for electronic component processing is then cut to a width of 25 mm to prepare a test piece. The porous substrate and the resin layer of the test piece are then forcibly peeled along the length of the test piece. The edges of the peeled portion between the porous substrate and the resin layer of the test piece are clamped with the grips of a tensile tester, and the peel strength between the porous substrate and the resin layer is measured by T-peel at a peel rate of 300 mm / min and a peel distance of 50 mm. The measurement environment is a temperature of 23°C and a humidity of 50% RH. For example, a Tensilon RTF1150 manufactured by A&D Corporation is used as the tensile tester.

[0074] As described below, when the resin layer has an adhesive layer and a resin substrate in that order from the porous substrate side, the peel force between the porous substrate and the resin layer is the peel force between the porous substrate and the resin substrate.

[0075] Examples of means for controlling the peel force between the porous substrate and the resin layer include adjusting the diameter of the threads of the porous substrate, applying a surface treatment to the porous substrate, adjusting the thickness of the resin layer, adjusting the components and composition contained in the resin layer, and adjusting the lamination conditions of the porous substrate and the resin layer.

[0076] In a method for adjusting the diameter of the threads of a porous substrate, for example, when the thickness of the resin layer is constant, a smaller average diameter of the threads increases the contact area between the porous substrate and the resin layer, which improves adhesion between the porous substrate and the resin layer and tends to increase the peel force.

[0077] In addition, 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.

[0078] In addition, in the method of adjusting the thickness of the resin layer, as described later, when the resin layer is a single layer, if the average fiber diameter of the porous substrate is constant, the thicker the resin layer, the larger the contact area between the porous substrate and the resin layer, so that the adhesion between the porous substrate and the resin layer is improved, and the peeling force tends to be larger. Also, as described later, when the resin layer has an adhesive layer and a resin substrate in order from the porous substrate side, if the average fiber diameter of the porous substrate is constant, the thicker the adhesive layer, the larger the contact area between the porous substrate and the adhesive layer, so that the adhesion between the porous substrate and the adhesive layer is improved, and the peeling force tends to be larger.

[0079] In addition, in the method of adjusting the components and composition contained in resin layer, as will be described later, when resin layer is a single layer, if the resin with low viscosity is used when laminating resin layer on porous substrate, such as curable resin, the contact area between porous substrate and resin layer will be large, so the adhesion between porous substrate and resin layer will be improved, and the peeling force will tend to be large.In addition, as will be described later, when resin layer has adhesive layer and resin substrate in order from porous substrate side, if the adhesive with high adhesive strength is used for adhesive layer, the adhesion between porous substrate and adhesive layer will be improved, and the peeling force will tend to be large.

[0080] Furthermore, as described below, when the resin layer has an adhesive layer and a resin substrate in this order from the porous substrate side, and when a pressure-sensitive adhesive is used in the adhesive layer and crosslinking is promoted by aging, methods for adjusting the lamination conditions between the porous substrate and the adhesive layer and resin substrate include adjusting the timing of aging and lamination of the pressure-sensitive adhesive, adjusting the lamination temperature, and adjusting the lamination pressure. By laminating the porous substrate with the adhesive layer and resin substrate before aging of the pressure-sensitive adhesive, the adhesion between the porous substrate and the adhesive layer improves, and the peel force tends to increase. Furthermore, by increasing the lamination temperature, the adhesion between the porous substrate and the adhesive layer improves, and the peel force tends to increase. Furthermore, by increasing the lamination pressure, the adhesion between the porous substrate and the adhesive layer improves, and the peel force tends to increase.

[0081] (d) Laser light absorption The resin layer preferably has laser light absorption properties. When the resin layer has laser light absorption properties used in water jet laser processing, the resin layer absorbs the laser light and is easily cut. This allows water to easily pass through during water jet laser processing. For example, as shown in FIG. 4, when the resin layer 3 is cut along with the workpiece substrate 11, water passes through the cut portion 13. As a result, chipping and flying chips caused by water splashing during water jet laser processing can be suppressed.

[0082] As will be described later, when the resin layer is a single layer, it is preferable that the resin layer has absorptivity to laser light. On the other hand, as will be described later, when the resin layer has an adhesive layer and a resin substrate in order from the porous substrate side, and when a pressure-sensitive adhesive is used for the adhesive layer, it is preferable that the resin substrate has absorptivity to laser light. In this case, the adhesive layer using the pressure-sensitive adhesive can be cut by water jet, so it does not need to have absorptivity to laser light. Also, as will be described later, when the resin layer has an adhesive layer and a resin substrate in order from the porous substrate side, and when a curing adhesive is used for the adhesive layer, it is preferable that the resin substrate and adhesive layer have absorptivity to laser light.

[0083] When the resin layer is a single layer, the laser light transmittance of the resin layer is, for example, 90% or less, or may be 70% or less, or may be 50% or less. If the laser light transmittance of the resin layer is within the above range, the resin layer can be cut by laser light. On the other hand, there is no particular limitation on the lower limit of the laser light transmittance of the resin layer. As will be described later, when the adhesive layer is an energy ray-curable adhesive layer, the resin layer preferably transmits energy rays.

[0084] When the resin layer has an adhesive layer and a resin substrate in that order from the porous substrate side, and a thermoplastic resin is used for the adhesive layer, the laser light transmittance of the resin substrate is the same as the laser light transmittance of the resin layer when the resin layer is a single layer.

[0085] Furthermore, when the resin layer has an adhesive layer and a resin substrate in that order from the porous substrate side, and a curable resin is used for the adhesive layer, the laser light transmittance of the resin substrate and the laser light transmittance of the adhesive layer are each the same as the laser light transmittance of the resin layer when the above-mentioned resin layer is a single layer.

[0086] (e) Energy ray transmittance As will be described later, when the adhesive layer is an energy ray-curable adhesive layer, the resin layer preferably transmits energy rays. The energy ray transmittance of the resin layer is, for example, 50% or more, or may be 70% or more, or 90% or more. When the energy transmittance of the resin layer is high within the above range, reflection and absorption of energy rays by the resin layer can be suppressed when the adhesive tape for electronic component processing is irradiated with energy rays from the resin layer side to cure the adhesive layer. This can suppress poor curing of the adhesive layer. On the other hand, there is no particular limitation on the upper limit of the energy transmittance of the resin layer.

[0087] (2) Form of resin layer The resin layer may be a single layer or may be a multilayer. In the case of a multilayer, the resin layer preferably has an adhesive layer and a resin substrate in this order from the porous substrate side. Hereinafter, the case where the resin layer is a single layer (first embodiment) and the case where the resin layer has an adhesive layer and a resin substrate in this order from the porous substrate side (second embodiment) will be described.

[0088] (a) First embodiment of resin layer The resin layer in this embodiment is a single layer. For example, in Fig. 1, the resin layer 3 is a single layer.

[0089] The material used for the resin layer is not particularly limited as long as it can provide a resin layer that satisfies the above-mentioned properties, and examples thereof include thermoplastic resins and curable resins.

[0090] The thermoplastic resin is not particularly limited as long as it can adhere the resin layer to the porous substrate by heat welding, and examples thereof include polyolefin, polyester, polyvinyl acetate, polyvinyl chloride, acrylic resin, polyurethane, polyamide, polystyrene, polyvinyl alcohol, and polycarbonate. Examples of polyolefin include polyethylene, polypropylene, and ethylene-vinyl acetate copolymer. Examples of polyester include polyethylene terephthalate, polyethylene naphthalate, and polybutylene terephthalate.

[0091] Examples of the curable resin include thermosetting resin and energy ray-curable resin. The energy ray is as described above. Examples of the curable resin include acrylic resin, epoxy resin, polyurethane, polyimide, etc.

[0092] The thickness of the resin layer is appropriately selected depending on the material used for the resin layer. The thickness of the resin layer is, for example, 10 μm to 100 μm, or 25 μm to 80 μm, or 50 μm to 60 μm. When the thickness of the resin layer is within the above range, the irregularities on the second surface of the porous substrate can be smoothed. Therefore, during the dicing process, the formation of a gap between the resin layer side of the adhesive tape for electronic component processing and the suction table can be suppressed. Therefore, the adhesive tape for electronic component processing attached to the substrate to be processed can be firmly fixed to the suction table, suppressing misalignment during dicing. Furthermore, when the upper limit of the resin layer thickness is within the above range, the resin layer is easily cut by laser light and water permeability can be increased. Therefore, chipping and chip flying due to water splashing during water jet laser processing can be suppressed. Furthermore, when a curable resin is used for the resin layer, the thickness of the resin layer is preferably thin within the above range. Furthermore, when a thermoplastic resin is used for the resin layer, the upper limit of the resin layer thickness is not limited to the above range and is not particularly limited. A resin layer made of a thermoplastic resin can be cut by a water jet even if the resin layer is thick, and the resin layer has high water permeability, which can prevent chipping and flying chips caused by water splashing during water jet laser processing.

[0093] The method for forming the resin layer is not particularly limited as long as a resin layer satisfying the above-mentioned properties can be obtained, and is appropriately selected depending on the material used for the resin layer. When a thermoplastic resin is used for the resin layer, examples of the method for forming the resin layer include a method in which a film-like resin layer is used and the resin layer is heat-sealed to the second surface of the porous substrate, and an extrusion lamination method. When a curable resin is used for the resin layer, examples of the method for forming the resin layer include a method in which an uncured or semi-cured film-like resin layer is used and the resin layer is laminated on the second surface of the porous substrate and then cured, and a method in which a curable resin composition is applied to the second surface of the porous substrate and then cured. In the case of the application method, it is preferable that the viscosity of the curable resin composition is high in order to suppress penetration of the curable resin composition into the porous substrate.

[0094] (b) Second embodiment of the resin layer The resin layer of this embodiment has, in order from the porous substrate side, an adhesive layer and a resin substrate. For example, in Fig. 6, the resin layer 3 has, in order from the porous substrate 1 side, an adhesive layer 3a and a resin substrate 3b.

[0095] (i) Resin substrate The material used for the resin substrate is not particularly limited as long as it can provide a resin substrate that satisfies the above-mentioned properties, and can be appropriately selected from known resins. Examples include polyesters such as polyethylene terephthalate, and polyolefins such as polyethylene and polypropylene. The resin substrate may be colorless or colored. A colored resin substrate has improved laser light absorption. When the laser light wavelength is 1064 nm, a resin substrate containing a material that absorbs 1064 nm infrared rays is preferably used. When the laser light wavelength is 532 nm, a light pink resin substrate is preferably used. When the laser light wavelength is 355 nm, a light yellow resin substrate is preferably used. Note that black or white resin substrates can also be used as long as the energy ray transmittance is 50% or higher.

[0096] The thickness of the resin substrate is, for example, preferably less than 100 μm, and may be 50 μm or less, or may be 10 μm or less. If the thickness of the resin substrate is within the above range, the resin substrate is easily cut by laser light, and water permeability can be increased. Therefore, the occurrence of chipping and flying chips due to water splashing during water jet laser processing can be suppressed. On the other hand, the thickness of the resin substrate is, for example, 10 μm or more, or may be 20 μm or more, or may be 50 μm or more. Specifically, the thickness of the resin substrate is 10 μm or more but less than 100 μm, or may be 20 μm or more and 50 μm or less.

[0097] (ii) Adhesive layer The adhesive used in the adhesive layer is not particularly limited as long as an adhesive layer satisfying the above-mentioned properties can be obtained, and examples thereof include pressure-sensitive adhesives and curing adhesives.

[0098] The adhesive used in the adhesive layer is not particularly limited, and a common adhesive can be used, such as an acrylic adhesive, a polyester adhesive, a urethane adhesive, a silicone adhesive, etc. An energy ray curable adhesive layer described below may also be used as the adhesive layer.

[0099] Examples of the curable adhesive used in the adhesive layer include a thermosetting adhesive and an energy ray curable adhesive. The energy ray is as described above. When the adhesive layer described below is an energy ray curable adhesive layer, the adhesive layer only needs to have strong adhesive strength and transmit energy rays, and for example, an uncured energy ray curable adhesive or a highly adhesive adhesive is used.

[0100] The thickness of the adhesive layer is appropriately selected depending on the adhesive used for the adhesive layer. The thickness of the adhesive layer is, for example, 30 μm or more and 200 μm or less, 50 μm or more and 150 μm or less, or 100 μm or more and 120 μm or less. When the thickness of the adhesive layer is within the above range, the adhesion between the porous substrate and the adhesive layer can be improved. Therefore, peeling of the adhesive layer due to the pressure of the water jet during water jet laser processing can be suppressed. Furthermore, since the gap between the porous substrate and the adhesive layer can be reduced, water intrusion between the porous substrate and the adhesive layer during water jet laser processing can be suppressed, and peeling of the adhesive layer can be suppressed. Therefore, misalignment during the dicing process can be suppressed. Furthermore, when a curable adhesive is used for the adhesive layer, the thickness of the adhesive layer is preferably thin. In this case, the thickness of the adhesive layer is, for example, 100 μm or less, or may be 50 μm or less, or 30 μm or less. When the thickness of the adhesive layer is within the above range, the adhesive layer is easily cut by laser light and water permeability can be increased. Furthermore, when a pressure-sensitive adhesive is used in the adhesive layer, the upper limit of the thickness of the adhesive layer is not limited to the above range and is not particularly limited. Even if the adhesive layer is thick, the adhesive layer using the pressure-sensitive adhesive can be cut by a water jet and can increase water permeability. Therefore, the occurrence of chipping and chipping due to water splashing during water jet laser processing can be suppressed.

[0101] As illustrated in Figure 6, the thickness T1 of the adhesive layer 3a is the length from the reference plane S3 to the outermost surface of the adhesive layer 3a on the porous substrate 1 side, when the outermost surface of the porous substrate 1 on the adhesive layer 3a side is set as the reference plane S3.

[0102] A method for disposing an adhesive layer and a resin substrate on the second surface of a porous substrate includes, for example, applying an adhesive layer composition to the resin substrate and then laminating the resin substrate and the porous substrate via the adhesive layer composition. When a pressure-sensitive adhesive is used for the adhesive layer, it is preferable to laminate the resin substrate and the porous substrate via the adhesive layer composition before aging the pressure-sensitive adhesive. Because the adhesive layer composition is in a soft state before aging the pressure-sensitive adhesive, it is possible to increase adhesion to the porous substrate and increase the peel strength between the porous substrate and the resin layer. Furthermore, when laminating the resin substrate and the porous substrate via the adhesive layer composition after aging the pressure-sensitive adhesive, it is preferable to perform thermal lamination. This can increase adhesion between the porous substrate and the adhesive layer and increase the peel strength between the porous substrate and the resin layer. When laminating the resin substrate and the porous substrate via the adhesive layer composition before aging the pressure-sensitive adhesive, it is possible to perform either room temperature lamination or thermal lamination.

[0103] 3. 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.

[0104] (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.

[0105] Examples of energy rays include light rays such as far ultraviolet rays, ultraviolet rays, near ultraviolet rays, visible light rays, and infrared rays, electromagnetic waves such as X-rays and gamma rays, as well as electron beams, proton beams, and neutron beams. Among these, from the viewpoint of versatility, ultraviolet rays and electron beams are preferred, and ultraviolet rays are more preferred.

[0106] The energy ray-curable adhesive layer is not particularly limited as long as it satisfies the desired adhesive properties, and can 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.

[0107] (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.

[0108] 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.

[0109] (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.

[0110] 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.

[0111] In this specification, (meth)acrylic acid refers to at least one of acrylic acid and methacrylic acid.

[0112] 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.

[0113] 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.

[0114] 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.

[0115] 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.

[0116] 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.

[0117] (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.

[0118] 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.

[0119] 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.

[0120] 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.

[0121] 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.

[0122] 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.

[0123] 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.

[0124] 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.

[0125] 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.

[0126] The energy ray-curable compounds may be used alone or in combination of two or more.

[0127] 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.

[0128] 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.

[0129] 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.

[0130] (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.

[0131] 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.

[0132] 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.

[0133] 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.

[0134] (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.

[0135] 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.

[0136] 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.

[0137] (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.

[0138] (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.

[0139] (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.

[0140] Here, the term "weak adhesive layer exhibits weak adhesion" means that the adhesive layer exhibits sufficient adhesive strength to fix the substrate and chip to the adhesive tape for electronic component processing sufficiently during the dicing process, and to easily peel the chip from the adhesive tape for electronic component processing during the peeling process.

[0141] The weak adhesive layer is not particularly limited as long as it has the desired adhesive properties. In particular, the weak adhesive layer preferably contains at least an acrylic resin, and more preferably contains an acrylic resin and a crosslinking agent.

[0142] 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.

[0143] 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.

[0144] (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.

[0145] 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.

[0146] In this specification, (meth)acrylic acid refers to at least one of acrylic acid and methacrylic acid.

[0147] 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.

[0148] 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.

[0149] 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.

[0150] 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.

[0151] 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.

[0152] 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.

[0153] 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.

[0154] (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.

[0155] 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.

[0156] (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.

[0157] (d) Other The method for forming the weakly adhesive layer is the same as the method for forming the energy ray curable adhesive layer.

[0158] (3) Thickness of adhesive layer The thickness of the adhesive layer may be any thickness that provides the desired adhesive strength, for example, 10 μm or more, 25 μm or more, or 50 μm or more. Because porous substrates have breathability in the planar direction, unevenness tends to exist on the first and second surfaces of the porous substrate. By ensuring that the thickness of the adhesive layer is equal to or greater than a predetermined value, unevenness on the first surface of the porous substrate can be smoothed out. This 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, if the adhesive layer is too thin, adhesion to the porous substrate may be reduced. Furthermore, if the adhesive layer is too thin, oxygen inhibition from the surface of the adhesive layer facing the porous substrate may result in poor curing. On the other hand, the thickness of the adhesive layer is, for example, 200 μm or less. If the adhesive layer is too thick, water permeability may be reduced.

[0159] As illustrated in Figure 6, the thickness T2 of the adhesive layer 2 is the length from the reference plane S4 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 defined as the reference plane S4.

[0160] 4. 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.

[0161] 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.

[0162] 5. 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.

[0163] 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.

[0164] 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.

[0165] 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.

[0166] 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 humidity of 50% RH. An example of a tensile tester used was a Tensilon RTF1150 manufactured by A&D Corporation.

[0167] Examples of means for controlling the peel force between the porous substrate and the adhesive layer after irradiation with energy rays include adjusting the diameter of the threads of the porous substrate, 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.

[0168] In a method of adjusting the diameter of the threads of the porous substrate, for example, when the thickness of the adhesive layer is constant, a smaller average diameter of the threads increases the contact area between the porous substrate and the adhesive layer, which improves adhesion between the porous substrate and the adhesive layer and tends to increase the peel force.

[0169] In addition, 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.

[0170] Furthermore, in the method of adjusting the thickness of the adhesive layer, when the average fiber diameter of the porous substrate is constant, 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.

[0171] Specific examples of methods for adjusting the components and composition of the adhesive layer include adjusting the content, number of functional groups, and molecular weight of the energy ray-curable compound, and 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, adding a tackifier tends to increase the peel force.

[0172] Furthermore, 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.

[0173] (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.

[0174] 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.

[0175] 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.

[0176] 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.

[0177] 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 adhesive tape for electronic component processing 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 grips 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. For example, a Tensilon RTF1150 manufactured by A&D Corporation is used as the tensile tester.

[0178] Examples of means for controlling the peel force between the porous substrate and the adhesive layer include adjusting the diameter of the threads in the porous substrate, 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.

[0179] The methods for adjusting the wire diameter of the porous substrate, the method for surface treating the porous substrate, the method for adjusting the thickness of the adhesive layer, and the method for adjusting the aging temperature during adhesive layer formation or lamination of the porous substrate and adhesive layer are the same as those for the energy ray-curable adhesive layer described above.

[0180] 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.

[0181] 6.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.

[0182] 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.

[0183] 7(a) to 7(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. 7(a), a bonding process 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. 7(b), a dicing process 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. 7(c), an irradiation process 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. 7(d), a pick-up process is performed in which the chip 12 is peeled from the adhesive tape 10 for electronic component processing and picked up. This pick-up process is a peeling process. Next, as shown in FIG. 7(e), a mounting (die bonding) process is performed in which the picked-up chip 12 is bonded to a substrate 26.

[0184] 8(a) to 8(e) are process diagrams illustrating another example of a method for manufacturing an electronic component according to the present disclosure. First, as shown in FIG. 8(a), an attachment step is performed in which the adhesive layer surface of the adhesive tape 10 for electronic component processing is attached to a ring frame 21, and then a substrate 11 to be processed is attached to the adhesive layer surface of the adhesive tape 10 for electronic component processing. Next, as shown in FIG. 8(b), a dicing step is performed in which the substrate 11 is divided into chips 12. Next, as shown in FIG. 8(c), a transfer tape 27 is attached to the surface of the chip 12 opposite to 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. 8(d). 8(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.

[0185] In the present disclosure, since the above-described pressure-sensitive adhesive tape for processing electronic components is used, it is possible to suppress misalignment during the dicing process.

[0186] A general method can be applied to each step in the method for manufacturing an electronic component according to the present disclosure.

[0187] In the dicing process, the substrate to be processed, which is fixed to the adhesive tape for electronic component processing, is fixed by suction to a suction table. A porous chuck or the like is used as the suction table. A glass suction table is preferably used as the suction table because it does not absorb laser light.

[0188] In particular, in the dicing step, it is preferable to divide the substrate into a plurality of chips by a laser guided by a water jet. General conditions can be adopted for the water jet laser processing.

[0189] 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]

[0190] Hereinafter, the present disclosure will be further described with reference to examples and comparative examples.

[0191] [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.

[0192] A polyethylene terephthalate (PET) film ("A4160" manufactured by Toyobo Co., Ltd., thickness 50 μm) was used as the resin substrate. The pressure-sensitive adhesive composition was applied to the resin substrate so that the thickness after drying was 50 μm, and dried in an oven at 110°C for 3 minutes to form an adhesive layer. Next, a porous substrate (nylon mesh "NB90" manufactured by NBC Meshtec Co., Ltd.) was laminated onto the adhesive layer at room temperature, and then aged at 40°C for 3 days. This resulted in a laminate having, in order, the resin substrate, adhesive layer, and porous substrate.

[0193] Next, the pressure-sensitive adhesive composition was applied to a polyethylene terephthalate (PET) separator (Nippa Corporation, "PET50x1-M-J2", thickness 50 μm) so that the thickness after drying was 50 μm, and dried in an oven at 110°C for 3 minutes to form an adhesive layer. Next, the porous substrate side of the laminate was laminated onto the adhesive layer, and then aged at 40°C for 3 days. This resulted in an adhesive tape for processing electronic components having, in order, a resin substrate, an adhesive layer, a porous substrate, an adhesive layer, and a separator.

[0194] [Example 2] An adhesive tape for processing electronic parts was produced in the same manner as in Example 1, except that the thickness of the adhesive layer was set to 30 μm.

[0195] [Example 3] An adhesive tape for processing electronic components was produced in the same manner as in Example 1, except that a laminate having a resin substrate, an adhesive layer, and a porous substrate in that order was produced by the following method.

[0196] The pressure-sensitive adhesive composition was applied to a resin substrate so that the thickness after drying was 50 μm, and the coating was dried in an oven at 110°C for 3 minutes to form an adhesive layer. A polyethylene terephthalate (PET) separator (Nippa Corporation's "PET50×1-M-J2", thickness 50 μm) was then laminated onto the adhesive layer, and aging was performed at 40°C for 3 days. The PET separator was then peeled off from the adhesive layer. A porous substrate (NBC Meshtec Corporation's nylon mesh "NB90") was then laminated onto the adhesive layer at 60°C. This resulted in a laminate having, in order, a resin substrate, an adhesive layer, and a porous substrate.

[0197] [Example 4] An adhesive tape for processing electronic parts was produced in the same manner as in Example 1, except that the thickness of the adhesive layer was set to 10 μm.

[0198] [Example 5] An adhesive tape for processing electronic parts was produced in the same manner as in Example 3, except that the temperature when laminating the porous substrate onto the adhesive layer was room temperature.

[0199] [Comparative Example 1] The same adhesive composition as in Example 1 was used. The adhesive composition was applied to a polyethylene terephthalate (PET) separator (Nippa Corporation, "PET50x1-M-J2", thickness 50 μm) so that the dried thickness was 50 μm, and dried in an oven at 110°C for 3 minutes to form an adhesive layer. Next, a porous substrate (NBC Meshtec Corporation, nylon mesh "NB90") was laminated onto the adhesive layer, and then aged at 40°C for 3 days. This produced an adhesive tape for processing electronic components, which had a porous substrate, an adhesive layer, and a separator in that order.

[0200] Comparative Example 2 The same adhesive composition as in Example 1 was used. The adhesive composition was applied to a polyethylene terephthalate (PET) separator (Nippa Corporation, "PET50x1-M-J2", thickness 50 μm) so that the thickness after drying was 50 μm, and dried in an oven at 110°C for 3 minutes to form an adhesive layer. Next, a 150 μm thick polypropylene (PP) film (Diaplus Film Corporation, "PL815T") was laminated onto the adhesive layer, and then aged at 40°C for 3 days. This produced an adhesive tape for processing electronic components, which had a PP film, an adhesive layer, and a separator in that order.

[0201] [evaluation] (1) Peel strength between porous substrate and resin substrate The peel strength between the porous substrate and the resin substrate was measured using a T-peel test with an A&D Tensilon RTF1150 tensile tester. Specifically, adhesive tape for electronic component processing was first cut to a width of 25 mm to prepare a test specimen. Next, the porous substrate and the resin substrate were forcibly peeled along the length of the test specimen. The edges of the peeled portion between the porous substrate and the resin substrate of the test specimen were clamped with the tensile tester's grippers. The peel strength between the porous substrate and the resin substrate was measured by performing a T-peel test at a peel rate of 300 mm / min and a peel distance of 50 mm. The measurement environment was a temperature of 23°C and a humidity of 50% RH.

[0202] (2) Vacuum suction The adhesive tape for electronic component processing was cut to a size of 210 mm x 210 mm to obtain a test piece. The adhesive tape for electronic component processing was placed on the 200 mm diameter ceramic porous chuck table of a tape remover "HTR0608-1" manufactured by Harmotec Corporation, and vacuum suction was initiated. The vacuum pump used for vacuum suction was the "DA-20D" vacuum pump manufactured by ULVAC Corporation. While the vacuum was being drawn, the differential pressure between the pressure inside the ceramic porous chuck table and atmospheric pressure was measured using a dial-type differential pressure gauge attached to the device. The vacuum suction was evaluated according to the following criteria. A: The differential pressure was -30kPa or less. B: The differential pressure was greater than -30 kPa.

[0203] (3) Positional deviation Adhesive tape for electronic component processing was applied to a ring frame for 6-inch wafers, and a 100 μm-thick 6-inch silicon wafer was adhered and fixed to the adhesive tape for electronic component processing. Using a water jet laser dicing device (SYNOVA's "Laser Microjet"), 30 cutting lines were cut vertically and horizontally at a cutting speed of 100 mm / s, a laser wavelength of 532 nm, a water jet diameter of 40 μm, and a water pressure of 250 bar. The wafer was then diced into 841 chips measuring 1.8 mm x 1.8 mm. The deviation of the actual cutting line positions from the center line of the dicing street (scribe line) as designed was then observed under a microscope. The deviation was evaluated according to the following criteria. A: The positional deviation was 10 μm or less. B: The positional deviation was more than 10 μm.

[0204] (4) Chip cracking The silicon wafer was diced in the same manner as in the evaluation of misalignment described above, and the presence or absence of chip cracks was checked.

[0205] (5) Air permeability in the surface direction of the substrate The in-plane breathability of the porous substrates used in Examples 1 to 5 and Comparative Example 1, as well as the in-plane breathability of the PP film used in Comparative Example 2, was confirmed. First, the substrate was cut to a size of 210 mm x 210 mm to obtain a test piece. The substrate was placed on a 200 mm diameter ceramic porous chuck table of a tape remover "HTR0608-1" manufactured by Harmotec Corporation. A 50 μm thick polyethylene terephthalate (PET) film was then placed on the substrate, and vacuum suction was initiated. During vacuum suction, a vacuum pump "DA-20D" manufactured by ULVAC was used. During vacuum suction, the differential pressure between the inside of the ceramic porous chuck table and the atmosphere was measured using a dial-type differential pressure gauge attached to the device. The differential pressure was -26 kPa for the porous substrate, demonstrating in-plane breathability. On the other hand, the differential pressure was -80 kPa for the PP film, demonstrating no in-plane breathability.

[0206] (6) Non-breathable resin substrate The breathability of the PET films used in Examples 1 to 5 was confirmed. First, the PET film was cut into a size of 210 mm x 210 mm to obtain a test piece. The PET film was placed on a 200 mm diameter ceramic porous chuck table of a tape remover "HTR0608-1" manufactured by Harmotec Corporation, and vacuum suction was initiated. During vacuum suction, a vacuum pump "DA-20D" manufactured by ULVAC was used. While the vacuum was being drawn, the differential pressure between the inside of the ceramic porous chuck table and the atmosphere was measured using a dial-type differential pressure gauge attached to the device. The differential pressure for the PET film was -80 kPa, indicating that the film was breathable.

[0207] [Table 1]

[0208] As in Examples 1 to 5, it was confirmed that misalignment was suppressed by arranging an adhesive layer and a resin substrate on the surface of the porous substrate opposite the adhesive layer. On the other hand, in Comparative Example 1, an adhesive layer and a resin substrate were not arranged on the surface of the porous substrate opposite the adhesive layer, so the adhesive tape for processing electronic components was not vacuum-adsorbed to the porous chuck table. In Comparative Example 2, because water did not permeate the PP film, the rebound of the water jet caused chip cracking.

[0209] Furthermore, a comparison between Examples 1 to 3 and Examples 4 and 5 confirmed that misalignment was effectively suppressed when the peel strength between the porous substrate and the resin substrate was equal to or greater than a predetermined value.

[0210] The present disclosure provides the following inventions. [1] A porous substrate having a first surface and a second surface opposite to the first surface and having air permeability in a surface direction; an adhesive layer disposed on the first surface of the porous substrate; a resin layer that is disposed on the second surface of the porous substrate and has air impermeability; An adhesive tape for processing electronic components, comprising: [2] The adhesive tape for processing electronic components according to [1], wherein the resin layer has, in order from the porous substrate side, an adhesive layer and a non-air-permeable resin substrate. [3] The adhesive tape for processing electronic parts according to [2], wherein the thickness of the resin substrate is less than 100 μm. [4] The adhesive tape for processing electronic parts according to [2] or [3], wherein the resin substrate has a laser light transmittance of 90% or less. [5] The pressure-sensitive adhesive tape for processing electronic parts according to any one of [2] to [4], wherein the adhesive layer has a thickness of 30 μm or more. [6] The adhesive tape for processing electronic components according to any one of [1] to [5], wherein the peel strength between the porous substrate and the resin layer is 2 N / 25 mm or more. [7] a step of attaching the adhesive tape for electronic component processing according to any one of [1] to [6] 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: [8] The method for manufacturing an electronic component according to [7], wherein the dicing step divides the substrate into a plurality of chips using a laser guided by a water jet. [Explanation of symbols]

[0211] 1 … Porous base material 2 … Adhesive layer 3...resin layer 3a… Adhesive layer 3b…Resin base material 10...Adhesive tape for electronic component processing

Claims

1. A porous substrate having a first surface and a second surface opposite to the first surface and having air permeability in a surface direction; an adhesive layer disposed on the first surface of the porous substrate; a resin layer having air impermeability and disposed on the second surface of the porous substrate; An adhesive tape for processing electronic components, comprising:

2. The pressure-sensitive adhesive tape for processing electronic components according to claim 1 , wherein the resin layer comprises, in order from the porous substrate side, an adhesive layer and a non-air-permeable resin substrate.

3. 3. The adhesive tape for processing electronic parts according to claim 2, wherein the resin substrate has a thickness of less than 100 μm.

4. 3. The pressure-sensitive adhesive tape for processing electronic parts according to claim 2, wherein the resin substrate has a laser light transmittance of 90% or less.

5. 3. The pressure-sensitive adhesive tape for processing electronic parts according to claim 2, wherein the adhesive layer has a thickness of 30 μm or more.

6. 2. The adhesive tape for processing electronic parts according to claim 1, wherein the peel strength between the porous substrate and the resin layer is 2 N / 25 mm or more.

7. a bonding step of bonding the adhesive tape for electronic component processing according to any one of claims 1 to 6 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:

8. The method for manufacturing an electronic component according to claim 7 , wherein the dicing step divides the substrate into a plurality of chips by a laser guided by a water jet.

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