Adhesive tape

Abstract

The purpose of the present invention is to provide an adhesive tape which is capable of accurately suppressing or preventing the occurrence of breakage in the adhesive tape when a substrate such as a semiconductor wafer stuck on the adhesive tape is cut into individual pieces in the thickness direction by means of irradiation of a laser beam. An adhesive tape 100 according to the present invention includes a base material 4 and an adhesive layer 2. The adhesive tape 100 is used when a substrate is cut into pieces, in the thickness direction, so as to form a plurality of components by irradiating the substrate with a laser beam in a state where the substrate is fixed on the adhesive layer 2, and subsequently each component is separated from the adhesive layer 2. The base material 4 has a weight loss rate from room temperature to 420°C in the TG curve obtained by simultaneous thermogravimetry differential thermal analysis that is 50% or less.

Description

adhesive tape

[0001] The present invention relates to an adhesive tape used for temporarily fixing a substrate and a component.

[0002] 2. Description of the Related Art In recent years, with the increasing sophistication of electronic devices and the expansion of mobile applications, there has been a growing demand for higher density and integration of semiconductor devices, and IC packages are becoming larger in capacity and higher in density.

[0003] In a manufacturing method of these semiconductor devices, for example, adhesive tape is first applied to a semiconductor substrate (semiconductor wafer) as a substrate. Then, a dicing process using a laser beam is performed while the periphery of the semiconductor substrate is fixed with a wafer ring. In the dicing process, a laser beam is applied to the semiconductor substrate to cut the semiconductor substrate in the thickness direction, thereby cutting and separating (singulating) the semiconductor substrate into individual semiconductor elements (semiconductor chips). Next, an expanding process is performed in which the adhesive tape is stretched radially using the wafer ring to form gaps between adjacent semiconductor elements. Then, a pick-up process is performed in which the singulated semiconductor elements are picked up while being pushed up with a needle. Next, the picked-up semiconductor elements are transferred to a mounting process in which they are mounted on a metal lead frame or a substrate (e.g., a tape substrate, an organic hard substrate, etc.). In the mounting process, the picked-up semiconductor elements are adhered to a lead frame or a substrate via, for example, an underfill material, and then the semiconductor elements are encapsulated on the lead frame or substrate with a sealing portion to manufacture a semiconductor device.

[0004] In such a method for manufacturing a semiconductor device using a laser beam to dice a semiconductor substrate, an adhesive tape (dicing tape) is used to temporarily fix the semiconductor substrate (semiconductor wafer) and the semiconductor elements that are separated from the semiconductor substrate (see, for example, Patent Document 1).

[0005] This adhesive tape generally has a substrate (film substrate) and an adhesive layer formed on the substrate, with the semiconductor substrate fixed to the adhesive layer. As in the semiconductor device manufacturing method described above, adhesive tapes having this configuration undergo an expanding process in which the adhesive tape is radially stretched after the dicing process in which the semiconductor substrate is diced by irradiating it with a laser beam. This forms gaps between adjacent semiconductor elements. In this state, a pick-up process is carried out in which the semiconductor elements are picked up.

[0006] In the dicing process described above, when a semiconductor substrate is cut in the thickness direction by irradiating it with a laser beam, the focus of the laser beam irradiated onto the semiconductor substrate is adjusted to the upper part of the semiconductor substrate or somewhere along the thickness direction of the semiconductor substrate. When the semiconductor substrate is thin, the focus of the laser beam is often adjusted to the upper part of the semiconductor substrate. This causes the semiconductor substrate to be cut along the thickness direction. At this time, the distance between the focus of the laser beam and the adhesive tape is short, which can result in unintended breakage of the adhesive tape. As a result, in the expanding and pick-up processes following the dicing process, the semiconductor elements cannot be positioned in the pre-designed positions, which poses a problem of being unable to pick up the semiconductor elements with high precision.

[0007] Furthermore, such problems are not limited to cases where semiconductor elements as components are obtained by cutting a semiconductor substrate (semiconductor wafer) as a substrate in the thickness direction, but also occur in cases where various substrates such as glass substrates, ceramic substrates, resin material substrates, and metal material substrates are cut (divided) in the thickness direction, and then the diced components are obtained by picking up the diced components while the adhesive tape is stretched radially.

[0008] Japanese Patent Application Laid-Open No. 2002-192370

[0009] The object of the present invention is to provide an adhesive tape that is used to detach components from an adhesive tape by sequentially going through an expanding process to stretch the adhesive tape and a pick-up process to pick up the components after a dicing process in which a substrate such as a semiconductor wafer attached to the adhesive tape is cut in the thickness direction by irradiating it with a laser beam to separate the components, and that can accurately suppress or prevent breakage of the adhesive tape when the substrate is diced.

[0010] The above object is achieved by the present invention as set forth in the following (1) to (10): (1) An adhesive tape comprising a substrate and an adhesive layer containing an adhesive base resin as a main material and laminated on one surface of the substrate, the adhesive tape being used when a substrate is fixed on the adhesive layer and a laser beam is irradiated onto the substrate to cut the substrate in its thickness direction and separate the substrate into individual components, and then the individual components are detached from the adhesive layer, the adhesive tape being characterized in that the substrate exhibits a weight loss rate of 50% or less from room temperature to 420°C in a TG curve obtained by simultaneous differential thermal and thermogravimetry analysis in accordance with JIS K 0129.

[0011] (2) The pressure-sensitive adhesive tape according to (1) above, wherein the substrate has a tensile modulus at 23° C. of 200 MPa or less.

[0012] (3) The adhesive tape according to (1) or (2) above, wherein the substrate contains a polyolefin resin as a main material.

[0013] (4) The pressure-sensitive adhesive tape according to any one of (1) to (3) above, wherein the polyolefin resin is a polyethylene resin.

[0014] (5) The pressure-sensitive adhesive tape according to any one of (1) to (4) above, wherein the polyethylene resin mainly contains a component having a specific gravity of 0.94 or less.

[0015] (6) The adhesive tape according to any one of (1) to (5) above, wherein the base resin is an acrylic resin.

[0016] (7) The adhesive tape according to any one of (1) to (6) above, wherein the adhesive layer further contains a curable resin that is cured by the application of energy, and is configured so that the adhesive strength of the adhesive layer to the substrate and the component is reduced by the application of energy.

[0017] (8) The adhesive tape according to any one of (1) to (7) above, wherein the substrate has a thickness of 30 μm or more and 300 μm or less.

[0018] (9) The adhesive tape according to any one of (1) to (8) above, wherein the adhesive layer has a thickness of 5 μm or more and 30 μm or less.

[0019] (10) The adhesive tape according to any one of (1) to (9) above, wherein the component is detached from the adhesive layer by stretching the adhesive tape in a planar direction, pushing up the component from the substrate side, and then pulling out the component from the opposite side of the substrate.

[0020] According to the present invention, a substrate such as a semiconductor wafer attached to an adhesive tape is cut in the thickness direction by irradiation with a laser beam to separate it into individual pieces, and components such as semiconductor chips are formed on the adhesive tape in a dicing process, followed by an expanding process to stretch the adhesive tape and a pick-up process to pick up the components, thereby accurately suppressing or preventing breakage of the adhesive tape when the substrate is separated into individual pieces in the adhesive tape used to detach the components from the adhesive tape. Therefore, the components can be picked up with excellent precision in the pick-up process.

[0021] Fig. 1 is a longitudinal sectional view showing an example of a semiconductor device manufactured using the pressure-sensitive adhesive tape of the present invention. Fig. 2 is a longitudinal sectional view illustrating a method for manufacturing the semiconductor device shown in Fig. 1 using the pressure-sensitive adhesive tape of the present invention. Fig. 3 is a longitudinal sectional view illustrating a method for manufacturing the semiconductor device shown in Fig. 1 using the pressure-sensitive adhesive tape of the present invention. Fig. 4 is a longitudinal sectional view illustrating a method for manufacturing the semiconductor device shown in Fig. 1 using the pressure-sensitive adhesive tape of the present invention. Fig. 5 is an enlarged sectional view showing a semiconductor chip formed by cutting a semiconductor substrate in the thickness direction by irradiation with a laser beam, located in the area [A] surrounded by a dotted line in Fig. 2. Fig. 6 is a longitudinal sectional view showing an embodiment of the pressure-sensitive adhesive tape of the present invention.

[0022] The pressure-sensitive adhesive tape of the present invention will be described in detail below with reference to preferred embodiments shown in the accompanying drawings. First, prior to describing the pressure-sensitive adhesive tape of the present invention, an example of a semiconductor device manufactured using the pressure-sensitive adhesive tape of the present invention will be described.

[0023] <Semiconductor Device> Figure 1 is a longitudinal cross-sectional view showing an example of a semiconductor device manufactured using the pressure-sensitive adhesive tape of the present invention. In the following description, the upper side in Figure 1 will be referred to as "top" and the lower side as "bottom." In addition, in each drawing referred to in this specification, dimensions in the left-right direction and / or thickness direction are exaggerated and differ significantly from the actual dimensions.

[0024] The semiconductor device 10 shown in FIG. 1 includes a semiconductor chip 20 (semiconductor element), an interposer 30 (substrate) that supports the semiconductor chip 20, a plurality of conductive bumps 70 (terminals), and a molded portion 17 (sealing portion) that seals the semiconductor chip 20.

[0025] The interposer 30 is an insulating substrate and is made of various resin materials such as polyimide, epoxy, cyanate, bismaleimide triazine (BT resin), etc. The planar shape of the interposer 30 is usually a quadrangle such as a square or rectangle.

[0026] Terminals 41 made of a conductive metal material such as copper are provided in a predetermined shape on the upper surface (one surface) of the interposer 30 .

[0027] Furthermore, a plurality of vias (through holes) (not shown) are formed in the interposer 30 so as to penetrate through the interposer 30 in the thickness direction.

[0028] Each bump 70 has one end (upper end) electrically connected to a part of the terminal 41 through a respective via, and the other end (lower end) protrudes from the lower surface (other surface) of the interposer 30 .

[0029] The portion of the bump 70 that protrudes from the interposer 30 is substantially spherical (ball-shaped).

[0030] The bumps 70 are mainly made of a brazing material such as solder, silver brazing, copper brazing, or phosphorus copper brazing.

[0031] Furthermore, terminals 41 are formed on the interposer 30. Terminals 21 of the semiconductor chip 20 are electrically connected to the terminals 41 via connecting portions 81.

[0032] In this embodiment, as shown in FIG. 1, the terminals 21 are configured to protrude from the surface formed on the semiconductor chip 20, and the terminals 41 are also configured to protrude from the interposer 30.

[0033] The gap between the semiconductor chip 20 and the interposer 30 is filled with an underfill material made of various resin materials, and the hardened underfill material forms a sealing layer 80. This sealing layer 80 has the function of improving the bonding strength between the semiconductor chip 20 and the interposer 30 and the function of preventing the intrusion of foreign matter, moisture, etc. into the gap.

[0034] Furthermore, a molded portion 17 is formed on the upper side of the interposer 30 so as to cover the semiconductor chip 20 and the interposer 30. The molded portion 17 is made of a hardened semiconductor sealing material (sealant). This seals the semiconductor chip 20 within the semiconductor device 10, preventing the intrusion of foreign matter, moisture, and the like into the semiconductor chip 20.

[0035] 1, the semiconductor chip 20 (semiconductor element) has a semiconductor chip body 23 (semiconductor element body) and terminals 21 provided so as to protrude from the lower surface side of the semiconductor chip body 23. A circuit (not shown) is built into the upper surface side of the semiconductor chip body 23, and the semiconductor chip body 23 is mainly made of Si, SiC, GaN, GaAs, or Ga. ２ O ３ It is made of semiconductor materials such as

[0036] The semiconductor device 10 and the semiconductor chip 20 having such a configuration are manufactured as follows by, for example, a semiconductor device manufacturing method using adhesive tape.

[0037] <Method for manufacturing a semiconductor device> Figures 2 to 4 are longitudinal cross-sectional views illustrating a method for manufacturing the semiconductor device shown in Figure 1 using the adhesive tape of the present invention, and Figure 5 is an enlarged cross-sectional view showing a semiconductor chip formed by cutting a semiconductor substrate in the thickness direction by irradiation with a laser beam, located in the area [A] surrounded by a dotted line in Figure 2. In the following description, the upper side in Figures 2 to 5 will be referred to as "upper" and the lower side will be referred to as "lower." In addition, in each of the drawings referred to in this specification, the dimensions in the left-right direction and / or thickness direction are exaggerated and differ significantly from the actual dimensions.

[0038] [1A] First, prepare an adhesive tape 100 (dicing tape) composed of a laminate having a base material 4 and an adhesive layer 2 laminated on the upper surface of the base material 4. Next, as shown in FIG. 2( a), a semiconductor substrate 7 (semiconductor wafer) is placed on the adhesive layer 2 at a position corresponding to the center 122 of the adhesive tape 100, and then lightly pressed. As a result, the semiconductor substrate 7 is laminated (attached) to the adhesive tape 100.

[0039] Circuits to be included in the semiconductor chips 20 formed by singulation are formed in advance on this semiconductor substrate 7. A plurality of these circuits are fabricated on the semiconductor substrate 7 so that the semiconductor chips 20 are arranged in a grid pattern. Therefore, the individual semiconductor chips 20 are obtained by cutting the semiconductor substrate 7 into a grid pattern in a plan view so that each circuit is independent. The lines along which the semiconductor substrate 7 is to be cut into a grid pattern are called planned cutting lines. Therefore, when the semiconductor substrate 7 is viewed in a plan view, a plurality of planned cutting lines are formed in a grid pattern (matrix pattern) along both the vertical and horizontal directions of the semiconductor substrate 7 in correspondence with the circuits of the semiconductor chips 20 arranged in a grid pattern on the semiconductor substrate 7.

[0040] [2A] Next, as shown in FIG. 2( b ), the adhesive tape 100 on which the semiconductor substrate 7 is laminated is placed on a dicer table 250 .

[0041] [3A] Next, the outer peripheral portion 121 of the adhesive layer 2 is fixed with a wafer ring 9. Thereafter, the semiconductor substrate 7 as a substrate is cut (diced) in the thickness direction by irradiation with a laser beam 151 by a light irradiator 150 (see FIG. 2(c)). Then, the cutting in the thickness direction of the semiconductor substrate 7 by irradiation with this laser beam 151 is carried out along the planned cutting lines of the semiconductor substrate 7, i.e., in a grid pattern.

[0042] As a result, the semiconductor substrate 7 is divided into individual pieces corresponding to the positions where the semiconductor chips 20 are fabricated. As a result, as shown in Fig. 2(d), a plurality of the divided semiconductor chips 20 are formed as parts in a state where they are adhered to the adhesive layer 2 on the adhesive tape 100 (dividing step).

[0043] At this time, the adhesive tape 100 has a buffering effect and prevents cracks, chips, etc. when the semiconductor substrate 7 is cut.

[0044] Furthermore, when cutting the semiconductor substrate 7 by irradiating the laser beam 151 using the light irradiator 150, the laser beam 151, which has a wavelength that is absorbed by the semiconductor substrate 7, is focused on the upper part of the semiconductor substrate 7 or midway through the thickness direction of the semiconductor substrate 7, and preferably, this focus is moved from the upper surface side to the lower surface side of the semiconductor substrate 7. This allows the semiconductor substrate 7 to be reliably divided into individual pieces.

[0045] Furthermore, the laser beam 151 applied by the light beam irradiator 150 is not particularly limited as long as it can cut the semiconductor substrate 7 along the thickness direction by irradiating the semiconductor substrate 7 with the laser beam 151. However, the laser beam 151 is preferably a pulsed laser beam, as shown in Fig. 5. When the laser beam 151 is a pulsed laser beam, it is possible to reliably suppress or prevent debris from adhering to the edge of the semiconductor chip 20 formed by cutting the semiconductor substrate 7 in the thickness direction.

[0046] In this specification, cutting of the semiconductor substrate 7 by irradiation with the laser beam 151 includes cutting based on the semiconductor substrate 7 being heated and melted at the focal point of the laser beam 151. In addition, for example, cutting can also be performed by following the process shown below. That is, a case in which a crack occurs or the refractive index of the semiconductor substrate 7 changes at the focal point of the laser beam 151, forming a modified layer (modified region) in the semiconductor substrate 7, and then applying an external force to the semiconductor substrate 7 with this modified layer formed causes a break in the modified layer, thereby cutting the semiconductor substrate 7.

[0047] Thus, in this step [3A], while the semiconductor substrate 7 is stacked on the adhesive tape 100, the semiconductor substrate 7 is irradiated with the laser beam 151, thereby cutting (dicing) the semiconductor substrate 7 in the thickness direction to obtain semiconductor chips 20 in which the semiconductor substrate 7 is separated. By using the adhesive tape 100, it is possible to accurately suppress or prevent breakage of the adhesive tape 100 caused by this step [3A]. Furthermore, it is possible to perform the expanding of the adhesive tape 100 in the subsequent step [5A] and the pick-up of the semiconductor chips 20 in the subsequent step [6A] with excellent precision. A detailed description of this will be provided later.

[0048] [4A] Next, as shown in Figure 3(a), the adhesive tape 100 on which the singulated semiconductor chips 20 are laminated (attached) is placed on the pickup table 200 with the outer periphery 121 of the adhesive layer 2 fixed by the wafer ring 9. Thereafter, the adhesive layer 2 is irradiated with energy rays via the base material 4, thereby reducing the adhesive force of the adhesive layer 2 to the semiconductor chips 20.

[0049] Examples of the energy beam include ultraviolet rays, electron beams, and particle beams such as ion beams, or a combination of two or more of these energy beams. Among these, ultraviolet rays are particularly preferred. Ultraviolet rays can efficiently reduce the adhesiveness of the adhesive layer 2 to the semiconductor chip 20.

[0050] The reduction in adhesive strength to the semiconductor chip 20 by irradiating the adhesive layer 2 with energy rays may be carried out prior to the expanding step as in this step [5A], or may be carried out after the expanding step. Moreover, the irradiation of energy rays is one example of a method for applying energy, and energy may be applied by other methods.

[0051] [5A] Next, on the pickup table 200, while the outer periphery 121 of the adhesive layer 2 is still fixed by the wafer ring 9, the center portion 210 is pushed upward against the outer periphery 220 of the pickup table 200. As a result, the adhesive tape 100 is expanded radially along its surface. This forms gaps 25 with a fixed spacing between the individual semiconductor chips 20 (see FIG. 3(b)).

[0052] [6A] Next, with the gap 25 formed by the above-mentioned step [5A], the semiconductor chip 20 is picked up by suction using a vacuum collet or air tweezers (pick-up step; see Figure 3(c)).

[0053] The pickup of the semiconductor chip 20 can be performed as follows. After the expanding step [5A] in which the adhesive tape 100 is radially stretched, a needle (not shown) provided on the pickup table 200 is protruded from the pickup table 200 in the thickness direction. As a result, the semiconductor chip 20 attached to the adhesive tape 100 is pushed up by the needle, and the semiconductor chip 20 is picked up in a state in which it can be easily peeled from the adhesive tape 100, as shown in FIG. 3( c). In other words, while the adhesive tape 100 is stretched in the planar direction, the semiconductor chip 20 (component) is pushed up from the substrate 4 side, and then pulled out from the opposite side of the substrate 4, whereby the semiconductor chip 20 can be detached from the adhesive layer 2.

[0054] By going through the above-described steps [1A] to [6A], the individual semiconductor chips 20 are separated from the semiconductor substrate 7 using the adhesive tape 100.

[0055] [7A] Next, the picked-up semiconductor chip 20 is transferred from the vacuum collet or air tweezers to a mounting probe or the like. Thereafter, as shown in FIG. 4( a), the terminals 21 of the semiconductor chip 20 and the terminals 41 of the interposer 30 are opposed to each other via the solder bumps 85 provided on the terminals 41, and the semiconductor chip 20 is placed on the interposer 30. That is, the semiconductor chip 20 (semiconductor element) is placed on the interposer 30 (substrate) with the surface of the semiconductor chip 20 on which the terminals 21 are formed facing downward.

[0056] [8A] Next, as shown in FIG. 4B, the interposer 30 and the semiconductor chip 20 are brought close to each other while the solder bumps 85 interposed between the terminals 21 and 41 are heated.

[0057] As a result, the molten solder bumps 85 come into contact with both the terminals 21 and 41, and are then cooled to form the connection portions 81. As a result, the terminals 21 and 41 are electrically connected via the connection portions 81 (see FIG. 4(c)).

[0058] [9A] Next, an underfill material (sealing material) made of various resin materials is filled into the gap formed between the semiconductor chip 20 and the interposer 30. Thereafter, the underfill material is cured to form a sealing layer 80 made of the cured underfill material (see FIG. 4(d)).

[0059] [10A] Next, a molded portion 17 (sealing portion) is formed on the upper side of the interposer 30 so as to cover the semiconductor chip 20 and the interposer 30. This seals the semiconductor chip 20 between the interposer 30 and the molded portion 17. In addition, bumps 70 are formed so as to protrude from the underside of the interposer 30, electrically connected to some of the terminals 41 through vias provided in the interposer 30 (see FIG. 4(e)).

[0060] Here, sealing with the molded portion 17 can be performed, for example, as follows. First, a molding die is prepared that has an internal space corresponding to the shape of the molded portion 17 to be formed. A powdered semiconductor encapsulation material is filled into this internal space so as to cover the semiconductor chip 20 and interposer 30 that are placed in the internal space. Then, in this state, the semiconductor encapsulation material is heated to harden it, resulting in a hardened semiconductor encapsulation material. In this way, sealing with the molded portion 17 is performed.

[0061] The semiconductor device manufacturing method having the steps described above can obtain the semiconductor device 10. More specifically, after performing the steps [1A] to [10A], the steps [6A] to [10A] can be repeatedly performed, thereby manufacturing a plurality of semiconductor devices 10 from a single semiconductor substrate 7 at once.

[0062] The present invention is applied to the adhesive tape 100 (dicing tape) used in the above-described method for manufacturing a semiconductor device. The adhesive tape 100 will be described below.

[0063] <Adhesive Tape 100> Figure 6 is a longitudinal cross-sectional view showing an embodiment of the adhesive tape of the present invention. In the following description, the upper side in Figure 6 will be referred to as "top" and the lower side as "bottom." In addition, in each drawing referred to in this specification, dimensions in the left-right direction and / or thickness direction are exaggerated and differ significantly from the actual dimensions.

[0064] In the manufacturing method of the semiconductor chip 20 described above, when a conventional adhesive tape is used instead of the adhesive tape 100, the following problem occurs. Specifically, in the step [3A], when the semiconductor substrate 7 is irradiated with the laser beam 151 to cut (diced) the semiconductor substrate 7 in the thickness direction to obtain the individual semiconductor chips 20 from the semiconductor substrate 7, breakage occurs in the conventional adhesive tape. Therefore, in the steps of expanding the conventional adhesive tape in the step [5A] and picking up the semiconductor chip 20 in the step [6A], which are steps subsequent to the step [3A], the semiconductor chip 20 cannot be positioned in a pre-designed position, and as a result, there is a problem that the semiconductor chip 20 cannot be picked up with high precision.

[0065] Here, in the step [3A], when the semiconductor substrate 7 is cut (diced) in the thickness direction by irradiating the semiconductor substrate 7 with the laser beam 151, the focus of the laser beam 151 irradiated onto the semiconductor substrate 7 is adjusted to the upper part of the semiconductor substrate 7 or midway in the thickness direction of the semiconductor substrate 7, thereby cutting the semiconductor substrate 7 along the thickness direction. At this time, due to the short distance between the focus of the laser beam 151 and the conventional adhesive tape, unintended breakage occurs in the conventional adhesive tape.

[0066] In contrast, in the present invention, the substrate 4 included in the pressure-sensitive adhesive tape 100 (the pressure-sensitive adhesive tape of the present invention) is a substrate whose weight loss rate from room temperature (25°C) to 420°C in the TG curve of the substrate 4 obtained by simultaneous differential thermal and thermogravimetry measurement in accordance with JIS K 0129 is 50% or less.

[0067] In this way, by selecting a substrate having a weight loss rate of 50% or less as the substrate 4, even if the laser beam 151 is irradiated onto the semiconductor substrate 7 in order to cut the semiconductor substrate 7 in the thickness direction in the step [3A] and the laser beam 151 is focused partway through the thickness direction of the semiconductor substrate 7, the breakage is limited to the adhesive layer 2 of the adhesive tape 100, and it is possible to reliably suppress or prevent the occurrence of breakage in the substrate 4 (see FIG. 5 ). Furthermore, even if the laser beam 151 is focused on an upper part of a thin semiconductor substrate 7 (for example, a semiconductor substrate 7 having a thickness of 100 μm or less), it is possible to reliably suppress or prevent the occurrence of breakage in the substrate 4.

[0068] Therefore, in the expanding of the adhesive tape 100 in step [5A], which is a process subsequent to step [3A], and in the picking up of the semiconductor chip 20 in step [6A], the semiconductor chip 20 can be accurately positioned in a pre-designed position, and therefore the picking up of the semiconductor chip 20 can be carried out with excellent precision.

[0069] The pressure-sensitive adhesive tape 100 to which the pressure-sensitive adhesive tape of the present invention is applied as described above is composed of a laminate including a sheet-shaped substrate 4 containing a resin material and an adhesive layer 2 laminated on the upper surface (one surface) of the substrate 4. The substrate 4 and the adhesive layer 2 will be described below.

[0070] The adhesive tape 100 has a function of reducing the adhesiveness of the adhesive layer 2 to the semiconductor substrate 7 and semiconductor chip 20 by applying energy to the adhesive layer 2. Methods of applying energy to the adhesive layer 2 include irradiating the adhesive layer 2 with energy rays and heating the adhesive layer 2. Among these, the method of irradiating the adhesive layer 2 with energy rays is preferably used because it does not require the semiconductor chip 20 to undergo unnecessary thermal history. Therefore, the following description will be given focusing on the adhesive layer 2 having a configuration in which the adhesiveness is reduced by irradiation with energy rays.

[0071] <Substrate 4> The substrate 4 is mainly made of a resin material, has a sheet shape, and has the function of supporting the adhesive layer 2 provided on the substrate 4. Furthermore, the substrate 4 is configured to realize extension of the adhesive tape 100 in the planar direction in the step [5A].

[0072] Furthermore, in the present invention, as described above, the base material 4 has a weight loss rate of 50% or less from room temperature (25°C) to 420°C in a TG curve obtained by simultaneous differential thermal and thermogravimetry analysis in accordance with JIS K 0129. Therefore, even if the laser beam 151 is focused partway through the thickness direction of the semiconductor substrate 7 in order to cut the semiconductor substrate 7 in the thickness direction in the step [3A], it is possible to reliably suppress or prevent breakage in the base material 4 and therefore the pressure-sensitive adhesive tape 100. Furthermore, even if the laser beam 151 is focused on an upper part of the thin semiconductor substrate 7, it is possible to reliably suppress or prevent breakage in the base material 4 and therefore the pressure-sensitive adhesive tape 100.

[0073] Examples of such resin materials include thermoplastic resins such as polyolefin resins, polyester resins (ester polymers) such as polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, and polybutylene naphthalate, polyvinyl chloride resins, polyurethane, polyimide, polyamide, polyether ketones such as polyether ether ketone, polyethersulfone, polystyrene, fluororesin, silicone resin, cellulose resins, styrene thermoplastic elastomers (styrene polymers), acrylic resins, polyester thermoplastic elastomers, polyvinyl isoprene, and polycarbonate (carbonate polymers), as well as mixtures of these thermoplastic resins. This makes it relatively easy to keep the weight loss rate of the substrate 4 at 50% or less.

[0074] These resin materials are materials that can transmit energy rays such as light (visible light, near-infrared light, ultraviolet light), X-rays, and electron beams, and are therefore preferably used when energy rays are transmitted through the substrate 4 from the substrate 4 side and irradiated onto the adhesive layer 2. Therefore, by irradiating the adhesive layer 2 with energy rays from the substrate 4 side, the adhesiveness of the adhesive layer 2 is reduced, making it possible to easily pick up the semiconductor chip 20. Furthermore, the weight reduction rate of the substrate 4 can be set to 50% or less with relative ease.

[0075] In particular, it is preferable to use a polyolefin-based resin as the resin material, since the use of a polyolefin-based resin can reliably impart extensibility (expandability) to the substrate 4 in the expanding step, and the weight loss rate of the substrate 4 can be more easily set to 50% or less.

[0076] Such polyolefin resins are not particularly limited, but examples thereof include polyethylene resins such as linear low-density polyethylene, low-density polyethylene, and very low-density polyethylene; ethylene-vinyl acetate copolymer (EVA), ethylene-methyl methacrylate copolymer (EMMA), ethylene-methacrylate copolymer (EMAA); and ethylene copolymers such as ionomers such as ethylene-based ionomers crosslinked with zinc ions, sodium ions, or potassium ions; and these resins may be used alone or in combination of two or more.

[0077] Furthermore, the polyolefin resin, particularly the polyethylene resin, preferably contains primarily a component having a specific gravity of 0.94 or less, more preferably a component having a specific gravity of 0.92 or less. This ensures that the weight loss rate of the substrate 4 is set to 50% or less. "Predominantly" means that the weight fraction of the component satisfying the above specific gravity range in the polyolefin resin (polyethylene resin) exceeds 50%.

[0078] Furthermore, the polyolefin resin, particularly the polyethylene resin, may be a mixture (blend) of a relatively low-specific-gravity component and a higher-specific-gravity component. This allows for a substrate 4 that can more accurately suppress or prevent breakage in the pressure-sensitive adhesive tape 100. The weight ratio of the low-specific-gravity component is preferably higher than the weight ratio of the high-specific-gravity component. Specifically, the weight fraction of the low-specific-gravity component in the polyolefin resin (polyethylene resin) is preferably 55% or more and 90% or less, and more preferably 60% or more and 80% or less. This allows for a substrate 4 that can particularly accurately suppress or prevent breakage in the pressure-sensitive adhesive tape 100.

[0079] The specific gravity of the low specific gravity component is preferably within the above range (preferably 0.94 or less, more preferably 0.92 or less). Furthermore, from the viewpoint of effectively improving the properties of the substrate 4, the difference in specific gravity between the low specific gravity component and the high specific gravity component is preferably 0.10 or more, and more preferably 0.15 to 0.50.

[0080] Furthermore, the base material 4 preferably contains a conductive material having electrical conductivity. By including such a conductive material, the conductive material can function as an antistatic agent, and can appropriately suppress or prevent static electricity from being generated in the semiconductor chips 20 formed by cutting the semiconductor substrate 7 in the step [3A].

[0081] The conductive material is not particularly limited as long as it is a material having conductivity, and examples of the conductive material include surfactants, permanently antistatic polymers (IDPs), metal materials, metal oxide materials, and carbon-based materials, and one or more of these may be used in combination.

[0082] Among these surfactants, examples include anionic surfactants, cationic surfactants, nonionic surfactants, and amphoteric surfactants.

[0083] As the permanently antistatic polymer (IDP), any IDP such as polyether and polyolefin block polymer series, polyesteramide series, polyesteramide, polyetheresteramide, polyurethane series, etc. can be used.

[0084] Examples of metal materials include gold, silver, copper or silver-coated copper, and nickel, and powders of these metals are preferably used.

[0085] Metal oxide materials include indium tin oxide (ITO), indium oxide (IO), antimony tin oxide (ATO), indium zinc oxide (IZO), and tin oxide (SnO ２ ), zinc oxide (ZnO), etc., and powders of these metal oxides are preferably used.

[0086] Further, examples of carbon-based materials include carbon black, carbon nanotubes such as single-walled carbon nanotubes and multi-walled carbon nanotubes, carbon nanofibers, CN nanotubes, CN nanofibers, BCN nanotubes, BCN nanofibers, and graphene.

[0087] Among these, the conductive material is preferably at least one of permanently antistatic polymers (IDPs), metal oxide materials, and carbon black. These materials have low humidity dependency of resistivity, so that even if the semiconductor substrate 7 is exposed to a dry environment, the amount of change in surface resistance can be reduced.

[0088] In this case, the surface resistivity of the upper surface (one surface) of the substrate 4 is preferably 1.0×10 ８ (Ω / □), more preferably 1.0×10 ８ (Ω / □) Super 1.0×10 １６ (Ω / □) or less, and the volume resistivity is preferably 1.0×10 １６ (Ω·m) or less, more preferably 1.0×10 １１ (Ω・m) or more 1.0×10 １３By setting the surface resistivity of the upper surface (one surface) of the base material 4 and the volume resistivity of the base material 4 as described above, the conductive material contained in the base material 4 can suitably exhibit its function as an antistatic agent, and can more reliably suppress or prevent static electricity from being generated in the semiconductor substrate 7 and the semiconductor chip 20 during dicing of the semiconductor substrate 7 in the step [3A], expanding of the adhesive tape 100 in the step [5A], and picking up of the semiconductor chip 20 in the step [6A].

[0089] Furthermore, the substrate 4 may contain a softener such as mineral oil, a filler such as calcium carbonate, silica, talc, mica, or clay, an antioxidant, a light stabilizer, a lubricant, a dispersant, a neutralizer, a colorant, or the like.

[0090] The thickness of the base material 4 is, for example, preferably 30 μm or more and 300 μm or less, and more preferably 50 μm or more and 250 μm or less. When the thickness of the base material 4 is within this range, the base material 4 can more reliably exhibit its function, and breakage of the base material 4 during dicing of the semiconductor substrate 7 by irradiation with the laser beam 151 in the step [3A] can be reliably suppressed or prevented, while the expanding (stretching) of the pressure-sensitive adhesive tape 100 in the step [5A] and the pick-up of the semiconductor chip 20 in the step [6A] can be carried out with excellent workability.

[0091] Furthermore, the substrate 4 may have exposed on its surface a functional group, such as a carboxyl group, a hydroxyl group, or an amino group, that is reactive with the constituent material contained in the adhesive layer 2 .

[0092] The substrate 4 may also be made of a laminate (multilayer body) in which a plurality of layers made of different resin materials are laminated together, or may be made of a blend film in which the resin materials are dry-blended.

[0093] As described above, the weight loss rate of the base material 4 may be 50% or less, but the weight loss rate is preferably 45% or less, and more preferably 40% or less, which makes it possible to more reliably suppress or prevent breakage of the base material 4 and, in turn, the pressure-sensitive adhesive tape 100 due to the irradiation of the semiconductor substrate 7 with the laser beam 151 in the step [3A].

[0094] On the other hand, the lower limit of the weight loss rate (weight loss rate from room temperature to 420°C) does not need to be set, but is preferably set to 15% or more, more preferably 20% or more, taking into consideration the balance with other properties of the substrate 4. This provides the substrate 4 with appropriate flexibility, and makes it possible to more reliably suppress or prevent breakage of the substrate 4 due to dicing, expanding, and pick-up.

[0095] Furthermore, in the substrate 4, the weight loss rate from room temperature (25°C) to 450°C in the TG curve obtained by simultaneous differential thermal and thermogravimetry analysis in accordance with JIS K 0129 is higher than the weight loss rate from room temperature to 420°C described above. Even in this case, the upper limit of the weight loss rate (weight loss rate from room temperature to 450°C) is preferably 95% or less, more preferably 90% or less, and even more preferably 80% or less. This makes it possible to more accurately suppress or prevent breakage in the substrate 4 and, ultimately, the pressure-sensitive adhesive tape 100 due to irradiation of the semiconductor substrate 7 with the laser beam 151 in the step [3A].

[0096] On the other hand, the lower limit of the weight loss rate (weight loss rate from room temperature to 450°C) does not need to be set, but is preferably set to more than 50%, more preferably 55% or more, taking into consideration the balance with other properties of the substrate 4. This provides the substrate 4 with appropriate flexibility, and makes it possible to more reliably suppress or prevent breakage of the substrate 4 due to dicing, expanding, and pick-up.

[0097] Furthermore, in the substrate 4, the weight loss rate from room temperature (25°C) to 400°C in the TG curve obtained by simultaneous differential thermal and thermogravimetry analysis in accordance with JIS K 0129 is lower than the weight loss rate from room temperature to 420°C described above. Even in this case, the upper limit of the weight loss rate (weight loss rate from room temperature to 400°C) is preferably 25% or less, more preferably 20% or less, and even more preferably 15% or less. This makes it possible to more accurately suppress or prevent breakage in the substrate 4 and, ultimately, the pressure-sensitive adhesive tape 100 due to irradiation of the semiconductor substrate 7 with the laser beam 151 in the step [3A]. Furthermore, good heat resistance can be imparted to the substrate 4.

[0098] On the other hand, the lower limit of the weight loss rate (weight loss rate from room temperature to 400°C) does not need to be set, but is preferably set to 3% or more, more preferably 5% or more, taking into consideration the balance with other properties of the substrate 4. This provides the substrate 4 with appropriate flexibility, and makes it possible to more reliably suppress or prevent breakage of the substrate 4 due to dicing, expanding, and pick-up.

[0099] Furthermore, the tensile modulus of elasticity of the substrate 4 at 23° C. is preferably 200 MPa or less, more preferably 40 MPa or more and 150 MPa or less, and even more preferably 50 MPa or more and 130 MPa or less, which allows the expanding (stretching) of the pressure-sensitive adhesive tape 100 in the step [5A], and further the pick-up of the semiconductor chip 20 in the step [6A], which is carried out after this expanding, to be carried out with excellent workability.

[0100] The substrate 4 may be irradiated with an electron beam. In this case, the substrate 4 is preferably irradiated with an electron beam at an absorbed dose of 20 to 300 kGy. In this case, the acceleration voltage of the electron beam irradiation is preferably 100 to 300 kV.

[0101] By irradiating the substrate 4 with an electron beam, it is possible to more accurately suppress or prevent breakage in the substrate 4 and, in turn, the adhesive tape 100 due to irradiation of the semiconductor substrate 7 with the laser beam 151 in the step [3A].

[0102] <Adhesive Layer 2> The adhesive layer 2 has the function of adhering and supporting the semiconductor substrate 7 when dicing the semiconductor substrate 7 in the step [3A]. Furthermore, the adhesive layer 2 is configured such that its adhesiveness to the semiconductor chip 20 decreases when energy is applied to the adhesive layer 2 in the step [4A]. This allows for easy separation between the semiconductor chip 20 obtained by dicing the semiconductor substrate 7 and the adhesive layer 2. As a result, the adhesive layer 2 can exert adhesive strength sufficient to allow the semiconductor chip 20 to be picked up in the step [6A].

[0103] The adhesive layer 2 having such a function is composed of a resin composition containing as its main materials (1) a base resin having adhesive properties and (2) a curable resin that hardens the adhesive layer 2. Below, each component contained in the resin composition will be explained in order.

[0104] (1) Base Resin The base resin has adhesiveness and is contained in the resin composition to impart adhesiveness to the semiconductor substrate 7 and ultimately to the semiconductor chip 20 to the adhesive layer 2 before the adhesive layer 2 is irradiated with energy rays.

[0105] Examples of such base resins include known resins used as adhesive layer components, such as acrylic resins (adhesives), silicone resins (adhesives), polyester resins (adhesives), polyvinyl acetate resins (adhesives), polyvinyl ether resins (adhesives), styrene elastomer resins (adhesives), polyisoprene resins (adhesives), polyisobutylene resins (adhesives), and urethane resins (adhesives). Among these, acrylic resins are preferred. Acrylic resins are preferred as base resins because they have excellent heat resistance and are relatively easy and inexpensive to obtain.

[0106] The acrylic resin refers to a resin having a polymer (homopolymer or copolymer) whose main monomer component is (meth)acrylic acid ester as the base polymer.

[0107] The (meth)acrylic acid ester is not particularly limited, and examples thereof include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, s-butyl (meth)acrylate, t-butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, isooctyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, nonyl (meth)acrylate, isononyl (meth)acrylate, and decyl (meth)acrylate. Examples of suitable acrylates include alkyl (meth)acrylates such as methyl (meth)acrylate, isodecyl (meth)acrylate, undecyl (meth)acrylate, dodecyl (meth)acrylate, tridecyl (meth)acrylate, tetradecyl (meth)acrylate, pentadecyl (meth)acrylate, hexadecyl (meth)acrylate, heptadecyl (meth)acrylate, and octadecyl (meth)acrylate; cycloalkyl (meth)acrylates such as cyclohexyl (meth)acrylate; and aryl (meth)acrylates such as phenyl (meth)acrylate. These acrylates may be used alone or in combination of two or more. Among these, alkyl (meth)acrylates such as methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, and octyl (meth)acrylate are preferred. Alkyl (meth)acrylates are particularly excellent in heat resistance and are readily and inexpensively available.

[0108] In this specification, the term "(meth)acrylic acid ester" is used to include both acrylic acid ester and methacrylic acid ester.

[0109] The acrylic resin is configured to contain a copolymerizable monomer as a monomer component constituting the polymer, if necessary, for the purpose of improving properties such as cohesive strength and heat resistance.

[0110] Such copolymerizable monomers are not particularly limited, and examples thereof include hydroxyl group-containing monomers such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, and 6-hydroxyhexyl (meth)acrylate; epoxy group-containing monomers such as glycidyl (meth)acrylate; carboxyl group-containing monomers such as (meth)acrylic acid, itaconic acid, maleic acid, fumaric acid, crotonic acid, and isocrotonic acid; acid anhydride group-containing monomers such as maleic anhydride and itaconic anhydride; amide monomers such as (meth)acrylamide, N,N-dimethyl(meth)acrylamide, N-butyl(meth)acrylamide, N-methylol(meth)acrylamide, N-methylolpropane(meth)acrylamide, N-methoxymethyl(meth)acrylamide, and N-butoxymethyl(meth)acrylamide; amino group-containing monomers such as aminoethyl (meth)acrylate, N,N-dimethylaminoethyl (meth)acrylate, and t-butylaminoethyl (meth)acrylate; Examples of suitable monomers include cyano group-containing monomers such as (meth)acrylonitrile, olefin monomers such as ethylene, propylene, isoprene, butadiene, and isobutylene, styrene monomers such as styrene, α-methylstyrene, and vinyltoluene, vinyl ester monomers such as vinyl acetate and vinyl propionate, vinyl ether monomers such as methyl vinyl ether and ethyl vinyl ether, halogen atom-containing monomers such as vinyl chloride and vinylidene chloride, alkoxy group-containing monomers such as methoxyethyl (meth)acrylate and ethoxyethyl (meth)acrylate, and monomers having a nitrogen atom-containing ring such as N-vinyl-2-pyrrolidone, N-methylvinylpyrrolidone, N-vinylpyridine, N-vinylpiperidone, N-vinylpyrimidine, N-vinylpiperazine, N-vinylpyrazine, N-vinylpyrrole, N-vinylimidazole, N-vinyloxazole, N-vinylmorpholine, N-vinylcaprolactam, and N-(meth)acryloylmorpholine. These may be used alone or in combination of two or more.

[0111] The content of these copolymerizable monomers is preferably 40% by weight or less, and more preferably 10% by weight or less, based on the total monomer components constituting the acrylic resin.

[0112] The copolymerizable monomer may be contained at the terminal of the main chain of the polymer constituting the acrylic resin, or may be contained in the main chain, or may be contained both at the terminal of the main chain and in the main chain.

[0113] Furthermore, the copolymerizable monomer may contain a polyfunctional monomer for the purpose of crosslinking between polymers.

[0114] Examples of polyfunctional monomers include 1,6-hexanediol (meth)acrylate, (poly)ethylene glycol di(meth)acrylate, (poly)propylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, pentaerythritol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, glycerin di(meth)acrylate, epoxy (meth)acrylate, polyester (meth)acrylate, urethane (meth)acrylate, divinylbenzene, butyl di(meth)acrylate, and hexyl di(meth)acrylate, and these may be used alone or in combination of two or more.

[0115] Furthermore, ethylene-vinyl acetate copolymers and vinyl acetate polymers can also be used as copolymerizable monomer components.

[0116] The acrylic resin preferably has a glass transition point of 20° C. or lower, which allows the adhesive layer 2 to exhibit excellent adhesiveness before being irradiated with energy rays.

[0117] Such an acrylic resin (polymer) can be produced by polymerizing a single monomer component or a mixture of two or more monomer components, and the polymerization of these monomer components can be carried out using a polymerization method such as solution polymerization, emulsion polymerization, bulk polymerization, or suspension polymerization.

[0118] It is preferable that the acrylic resin has a functional group (reactive functional group) that is reactive with a crosslinking agent or a photopolymerization initiator, such as a hydroxyl group or a carboxyl group (particularly a hydroxyl group). This allows the crosslinking agent or photopolymerization initiator to be linked to the acrylic resin, which is a polymer component, thereby effectively suppressing or preventing leakage of the crosslinking agent or photopolymerization initiator from the adhesive layer 2. As a result, the adhesiveness of the adhesive layer 2 to the semiconductor substrate 7 and ultimately to the semiconductor chip 20 is reliably reduced by the energy ray irradiation in the step [4A].

[0119] (2) Curable Resin The curable resin has a curing property such that it is cured by, for example, irradiation with energy rays. As a result of this curing, the base resin is incorporated into the cross-linked structure of the curable resin, and as a result, the adhesive strength of the adhesive layer 2 decreases.

[0120] As such a curable resin, for example, a low molecular weight compound having at least two polymerizable carbon-carbon double bonds in the molecule as functional groups that can be three-dimensionally crosslinked by irradiation with energy rays such as ultraviolet rays or electron beams is used.

[0121] Specifically, examples of the curable resin include trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, tetramethylolmethane tetra(meth)acrylate, tetraethylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, dipentaerythritol hexa(meth)acrylate, and dipentaerythritol monohydroxypenta(meth)acrylate. (Meth)acrylate, 1,4-butylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, esterification products of (meth)acrylic acid and polyhydric alcohol such as glycerin di(meth)acrylate, ester acrylate oligomer, cyanurate compounds having a carbon-carbon double bond-containing group such as 2-propenyl-di-3-butenyl cyanurate, tris(2-acryloxyethyl)isocyanurate, tris(2-methacryloxyethyl)isocyanurate, 2-hydroxyethyl Examples of the urethane acrylate include isocyanurate compounds having a carbon-carbon double bond-containing group, such as bis(2-acryloxyethyl)isocyanurate, bis(2-acryloxyethyl)2-[(5-acryloxyhexyl)oxy]ethyl isocyanurate, tris(1,3-diacryloxy-2-propyl-oxycarbonylamino-n-hexyl)isocyanurate, tris(1-acryloxyethyl-3-methacryloxy-2-propyl-oxycarbonylamino-n-hexyl)isocyanurate, and tris(4-acryloxy-n-butyl)isocyanurate; commercially available oligoester acrylates; epoxy acrylates such as bis-F type epoxy acrylate and bis-A type epoxy acrylate; urethane acrylate; polyester acrylate; and aromatic and aliphatic urethane acrylates, and these may be used alone or in combination of two or more. Among these, it is preferable to contain at least one of epoxy acrylate, urethane acrylate, and polyester acrylate, and urethane acrylate is more preferable.

[0122] The urethane acrylate is not particularly limited, but can be obtained, for example, by reacting a polyol compound such as a polyester type or polyether type with a polyvalent isocyanate compound (for example, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1,3-xylylene diisocyanate, 1,4-xylylene diisocyanate, diphenylmethane 4,4-diisocyanate, etc.) to obtain an isocyanate-terminated urethane prepolymer, with a (meth)acrylate having a hydroxyl group (for example, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, polyethylene glycol (meth)acrylate, etc.).

[0123] Examples of polyester acrylates include polyester (meth)acrylates.

[0124] Furthermore, the curable resin may be, but is not limited to, a mixture of two or more curable resins with different weight-average molecular weights. By using such a curable resin, the degree of crosslinking of the resin due to energy ray irradiation can be easily controlled, and the semiconductor chip 20 can be easily picked up from the adhesive layer 2. Furthermore, as such a curable resin, for example, a mixture of a first curable resin and a second curable resin having a weight-average molecular weight greater than that of the first curable resin may be used.

[0125] The curable resin is preferably blended in an amount of 5 parts by weight to 100 parts by weight, more preferably 10 parts by weight to 100 parts by weight, and even more preferably 20 parts by weight to 100 parts by weight, relative to 100 parts by weight of the base resin. By adjusting the blending amount of the curable resin as described above, the semiconductor chip 20 can be easily picked up from the adhesive layer 2.

[0126] When a double-bond-introduced acrylic resin is used as the base resin, that is, when an acrylic resin having a carbon-carbon double bond in a side chain, in the main chain, or at the end of the main chain is used, the addition of this curable resin to the resin composition may be omitted. This is because, when the acrylic resin is a double-bond-introduced acrylic resin, the adhesive layer 2 is cured by irradiation with energy rays due to the function of the carbon-carbon double bond of the double-bond-introduced acrylic resin, and as a result, the adhesive strength of the adhesive layer 2 is reduced.

[0127] (3) Photopolymerization initiator The adhesive layer 2 is configured so that its adhesiveness to the semiconductor substrate 7 and ultimately to the semiconductor chip 20 decreases when irradiated with energy rays. When ultraviolet rays or the like are used as the energy rays, it is preferable that the curable resin contains a photopolymerization initiator to facilitate the initiation of polymerization of the curable resin.

[0128] Examples of the photopolymerization initiator include 2,2-dimethoxy-1,2-diphenylethan-1-one, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propan-1-one, 2-hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propionyl)-benzyl]phenyl}-2-methyl-propan-1-one, benzyl diphenyl sulfide, tetramethylthiuram monosulfide, 4-(2-hydroxyethoxy)phenyl(2-hydroxy-2-propyl)ketone, α-hydroxy-α,α'-diphenyl Methylacetophenone, 2-methyl-2-hydroxypropiophenone, 1-hydroxycyclohexyl phenyl ketone, Michler's ketone, acetophenone, methoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxyacetophenone, 2-methyl-1-[4-(methylthio)-phenyl]-2-morpholinopropan-1-one, benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzyl, benzoin , dibenzyl, α-hydroxycyclohexyl phenyl ketone, benzil dimethyl ketal, 2-hydroxymethylphenylpropane, 2-naphthalenesulfonyl chloride, 1-phenone-1,1-propanedione-2-(o-ethoxycarbonyl)oxime, benzophenone, benzoylbenzoic acid, 4,4'-dimethylaminobenzophenone, 4,4'-diethylaminobenzophenone, 4,4'-dichlorobenzophenone, 3,3'-dimethyl-4-methoxybenzophenone, o-acryloxybenzophenone, p-acryloxybenzophenone Benzophenone-4-carboxylic acid esters of acrylates such as benzophenone, o-methacryloxybenzophenone, p-methacryloxybenzophenone, p-(meth)acryloxyethoxybenzophenone, 1,4-butanediol mono(meth)acrylate, 1,2-ethanediol mono(meth)acrylate, 1,8-octanediol mono(meth)acrylate, thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, 2,4-dichlorothioxanthone, 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone, azobisisobutyronitrile, β-chloroanthraquinone, camphorquinone, halogenated ketone, acylphosphinoxide, acylphosphonate, polyvinylbenzophenone, chlorothioxanthone, dodecylthioxanthone, dimethylthioxanthone, diethylthioxanthone, 2-ethylanthraquinone, t-butylanthraquinone, 2,4,5-triarylimidazole dimer, and the like, and these can be used alone or in combination of two or more.

[0129] Among these, benzophenone derivatives and alkylphenone derivatives are preferred. These compounds have a hydroxyl group as a reactive functional group in the molecule, and can be linked to a base resin or a curable resin via this reactive functional group, allowing them to more reliably function as a photopolymerization initiator.

[0130] The photopolymerization initiator is preferably blended in an amount of 0.1 to 50 parts by weight, and more preferably 0.5 to 10 parts by weight, per 100 parts by weight of the base resin. By adjusting the blending amount of the photopolymerization initiator as described above, the pickup properties of the semiconductor chip 20 can be optimized.

[0131] (4) Crosslinking Agent The curable resin may further contain a crosslinking agent, which improves the curability of the curable resin.

[0132] The crosslinking agent is not particularly limited, but examples thereof include isocyanate-based crosslinking agents, epoxy-based crosslinking agents, urea resin-based crosslinking agents, methylol-based crosslinking agents, chelate-based crosslinking agents, aziridine-based crosslinking agents, melamine-based crosslinking agents, polyvalent metal chelate-based crosslinking agents, acid anhydride-based crosslinking agents, polyamine-based crosslinking agents, carboxyl group-containing polymer-based crosslinking agents, etc. Among these, isocyanate-based crosslinking agents are preferred.

[0133] The isocyanate-based crosslinking agent is not particularly limited, but examples thereof include polyisocyanate compounds of polyvalent isocyanates, trimers of polyisocyanate compounds, trimers of isocyanate-terminated compounds obtained by reacting a polyisocyanate compound with a polyol compound, and blocked polyisocyanate compounds in which isocyanate-terminated urethane prepolymers are blocked with phenol, oximes, or the like.

[0134] Examples of polyisocyanates include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1,3-xylylene diisocyanate, 1,4-xylylene diisocyanate, diphenylmethane-4,4'-diisocyanate, diphenylmethane-2,4'-diisocyanate, 3-methyldiphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, dicyclohexylmethane-2,4'-diisocyanate, 4,4'-diphenylether diisocyanate, 4,4'-[2,2-bis(4-phenoxyphenyl)propane]diisocyanate, and 2,2,4-trimethyl-hexamethylene diisocyanate. These may be used alone or in combination of two or more. Among these, at least one polyisocyanate selected from the group consisting of 2,4-tolylene diisocyanate, diphenylmethane-4,4'-diisocyanate, and hexamethylene diisocyanate is preferred.

[0135] The crosslinking agent is preferably blended in an amount of 0.01 to 50 parts by weight, more preferably 5 to 50 parts by weight, per 100 parts by weight of the base resin. By adjusting the blending amount of the crosslinking agent as described above, the pick-up properties of the semiconductor chip 20 from the adhesive layer 2 can be optimized.

[0136] (5) Plasticizer Furthermore, a plasticizer may be contained in the resin composition constituting the adhesive layer 2. By containing a plasticizer, it is possible to improve the flexibility of the adhesive layer 2, whose adhesive strength decreases when energy is applied.

[0137] The plasticizer is not particularly limited, but examples thereof include phthalate ester plasticizers such as DOP (dioctyl phthalate), DBP (dibutyl phthalate), DIBP (diisobutyl phthalate), and DHP (diheptyl phthalate); aliphatic dibasic acid ester plasticizers such as DOA (di-2-ethylhexyl adipate), DIDA (diisodecyl adipate), and DOS (di-2-ethylhexyl sebacate); aromatic carboxylic acid ester plasticizers such as ethylene glycol benzoates; trimellitic acid ester plasticizers such as TOTM (trioctyl trimellitate); adipate ester plasticizers; and polyester plasticizers. One or more of these may be used in combination. Among these, polyester plasticizers are preferred. By using a polyester plasticizer as the plasticizer, the effects obtained by including a plasticizer in the resin composition constituting the adhesive layer 2 can be more significantly exhibited.

[0138] Polyester plasticizers are obtained by a condensation polymerization reaction between a polycarboxylic acid such as adipic acid, azelaic acid, sebacic acid, phthalic acid, isophthalic acid, or terephthalic acid and a glycol such as ethylene glycol, propylene glycol, butylene glycol, neopentyl glycol, or hexanediol.

[0139] The content of the plasticizer in the adhesive layer 2, i.e., the resin composition, is not particularly limited, but is preferably 8% by weight to 60% by weight, more preferably 10% by weight to 58% by weight, and even more preferably 15% by weight to 55% by weight, which reliably improves the flexibility of the adhesive layer 2 and more significantly enhances the effect of the adhesive layer 2 containing the plasticizer.

[0140] (6) Conductive Material (Antistatic Agent) Furthermore, it is preferable that a conductive material having electrical conductivity is contained in the resin composition constituting the adhesive layer 2. By including such a conductive material, the conductive material can function as an antistatic agent, and the generation of static electricity in the semiconductor chip 20 in the above-described method for manufacturing the semiconductor chip 20 can be accurately suppressed or prevented.

[0141] The conductive material is not particularly limited as long as it has conductivity. As with the conductive material that can be contained in the base material 4, examples of the conductive material include surfactants, permanently antistatic polymers (IDPs), metal materials, metal oxide materials, and carbon-based materials, and one or more of these may be used in combination.

[0142] When a conductive material is contained in either the base material 4 or the adhesive layer 2, it is preferable to contain the conductive material in the base material 4. This makes it possible to more reliably suppress or prevent the generation of static electricity on the semiconductor chip 20 without having to reliably attach the conductive material to the semiconductor chip 20.

[0143] (7) Other Components The resin composition constituting the adhesive layer 2 may further contain, in addition to the above-described components (1) to (6), at least one of other components selected from the group consisting of a tackifier, an antioxidant, an adhesion adjuster, a filler, a colorant, a flame retardant, a softener, an antioxidant, and a surfactant as a leveling agent.

[0144] Among these, the tackifier is not particularly limited, but examples thereof include rosin resins, terpene resins, coumarone resins, phenolic resins, aliphatic petroleum resins, aromatic petroleum resins, and aliphatic-aromatic copolymer petroleum resins, and one or more of these may be used in combination.

[0145] The average thickness of the adhesive layer 2 is not particularly limited, but is preferably 5 μm to 30 μm, more preferably 7 μm to 25 μm, and even more preferably 10 μm to 20 μm. By setting the average thickness of the adhesive layer 2 within this range, the adhesive layer 2 exhibits good adhesive strength before energy is applied to the adhesive layer 2, and exhibits good peelability between the adhesive layer 2 and the semiconductor chip 20 after energy is applied to the adhesive layer 2.

[0146] The adhesive layer 2 may be formed as a laminate (multilayer body) in which a plurality of layers made of different resin compositions are laminated.

[0147] Furthermore, the adhesive tape 100 having such a configuration can be manufactured in a state where it is formed on a separator, for example, by applying or spraying onto a separator a liquid material in the form of a varnish obtained by dissolving the resin composition that is the constituent material of the adhesive layer 2 in a solvent, and then volatilizing the solvent to form the adhesive layer 2, and then pressing the substrate 4 onto the surface of this adhesive layer 2 opposite the separator.

[0148] The adhesive tape 100 manufactured as described above is used after peeling the adhesive tape 100 from the separator in the method for manufacturing a semiconductor device using the adhesive tape 100 described above.

[0149] Although the pressure-sensitive adhesive tape of the present invention has been described above, the present invention is not limited thereto.

[0150] For example, any component capable of exerting the same function may be added to each layer of the pressure-sensitive adhesive tape of the present invention, or the substrate may be composed of a single layer as described in the above embodiment, or may be composed of multiple layers, and for example, an antistatic layer may be provided on the surface of the above-mentioned substrate opposite to the pressure-sensitive adhesive layer.

[0151] Furthermore, the configuration of each layer of the adhesive tape can be replaced with any configuration that can exert a similar function, or any configuration can be added.

[0152] Furthermore, the adhesive tape can be used when semiconductor chips (semiconductor elements) are obtained as individual components by irradiating a semiconductor substrate as a substrate with a laser beam, but the tape can also be used in the same way when cutting (dividing) various substrates such as glass substrates, ceramic substrates, resin material substrates, and metal material substrates in the thickness direction by irradiating them with a laser beam.

[0153] Furthermore, depending on the configuration of the semiconductor device formed using the adhesive tape, it may be possible to omit the formation of the molded portion 17 provided in the semiconductor device 10 .

[0154] The semiconductor chip 20 manufactured using the adhesive tape of the present invention can be widely used in, for example, mobile phones, digital cameras, video cameras, car navigation systems, personal computers, game consoles, liquid crystal televisions, liquid crystal displays, organic electroluminescence displays, printers, etc.

[0155] Next, specific examples of the present invention will be described, but the present invention is not limited to the descriptions of these examples.

[0156] 1. Preparation of Raw Materials First, the raw materials used in the production of the pressure-sensitive adhesive tapes of the Examples and Comparative Examples are listed below.

[0157] (Polyolefin Resin 1) As polyolefin resin 1, a mixture containing linear low density polyethylene (LLDPE) and low density polyethylene (LDPE) in a weight ratio (LLDPE:LDPE) of 7:3 was prepared.

[0158] (Polyolefin Resin 2) As polyolefin resin 2, a mixture containing linear low density polyethylene (LLDPE) and low density polyethylene (LDPE) in a weight ratio (LLDPE:LDPE) of 6:4 was prepared.

[0159] (Polyolefin Resin 3) As polyolefin resin 3, a mixture containing linear low density polyethylene (LLDPE) and low density polyethylene (LDPE) in a weight ratio (LLDPE:LDPE) of 8:2 was prepared.

[0160] (Polyolefin Resin 4) As polyolefin resin 4, an ethylene-methacrylic acid copolymer (EMAA) having an acid content of 9% was prepared.

[0161] (Polyolefin Resin 5) As polyolefin resin 5, an ethylene-vinyl acetate copolymer (EVA) having a vinyl acetate content of 16% was prepared.

[0162] (Polyolefin Resin 6) As polyolefin resin 6, a mixture containing polypropylene (PP) and styrene-isoprene-styrene block copolymer (SIS) in a weight ratio (PP:SIS) of 6:4 was prepared.

[0163] (Antistatic Agent) A polyether-based antistatic agent ("Pelectron PVL" manufactured by Sanyo Chemical Industries, Ltd.) was prepared as the antistatic agent.

[0164] (Base Resin) As base resin 1, an acrylic copolymer was prepared by mixing four types of resins, namely, acrylic acid, 2-hydroxyethyl acrylate, 2-ethylhexyl acrylate, and butyl methacrylate, and solution polymerizing the mixture in a toluene solvent by a conventional method.

[0165] The glass transition point and weight average molecular weight of base resin 1 (acrylic copolymer) were -37°C and 600,000, respectively.

[0166] (Curable Resin) Urethane acrylate (manufactured by Miwon Specialty Chemical Co., Ltd., product number: SC2152) was prepared as the curable resin.

[0167] (Crosslinking Agent) Polyisocyanate (manufactured by Tosoh Corporation, product number: Coronate L) was prepared as a crosslinking agent.

[0168] (Photopolymerization initiator) Benzyl dimethyl ketal (manufactured by Tokyo Chemical Industry Co., Ltd.) was prepared as a photopolymerization initiator.

[0169] 2. Preparation of Adhesive Tape Example 1 Polyolefin resin 1 (100 parts by weight) was extruded as a resin composition using an extruder to prepare a substrate 4 having a thickness of 150 μm.

[0170] Next, a liquid material containing a resin composition containing a base resin (100 parts by weight), a curable resin (40 parts by weight), a crosslinking agent (2 parts by weight), and a photopolymerization initiator (5 parts by weight) was prepared. This liquid material was bar-coated onto a PET separator so that the thickness of the adhesive layer 2 after drying would be 10 μm, and then dried at 80° C. for 1 minute to form an adhesive layer 2 on the upper surface (one side) of the separator.

[0171] Next, the substrate 4 prepared above was attached to the upper surface of the adhesive layer 2, thereby obtaining the adhesive tape 100 of Example 1 covered with a separator.

[0172] [Examples 2 to 8, Comparative Examples 1 and 2] Pressure-sensitive adhesive tapes of Examples 2 to 8 and Comparative Examples 1 and 2 were obtained in the same manner as in Example 1, except that the types and contents of each constituent material in the resin composition were changed as shown in Table 1.

[0173] 3. Evaluation <Measurement of Weight Loss Rate in TG Curve of Substrate> For the substrate 4 provided in the pressure-sensitive adhesive tape 100 of each Example and Comparative Example, simultaneous differential thermal and thermogravimetric measurements were performed using the apparatus and conditions described below in accordance with JIS K 0129 to obtain a TG curve for the substrate 4. Then, using the obtained TG curve, the weight loss rate from room temperature (25°C) to 400°C, the weight loss rate from room temperature (25°C) to 420°C, and the weight loss rate from room temperature (25°C) to 450°C were determined. Measuring apparatus: STA200 (manufactured by Hitachi High-Tech Science Corporation) Atmospheric gas: Nitrogen Gas introduction rate: 200 ml / min Heating rate: 5°C / min

[0174] <Measurement of tensile modulus of substrate> For the pressure-sensitive adhesive tape 100 of each Example and Comparative Example, the tensile modulus of the substrate 4 was measured using a universal tensile tester ("RTH-1225" manufactured by A&D Co., Ltd.) The measurement was performed in accordance with JIS K 7161:2014 in an environment of 23°C at a pulling rate of 2 mm / min.

[0175] <Evaluation of the Presence or Absence of Fracture in Adhesive Tape> The adhesive tape 100 of each Example and Comparative Example was peeled from the separator, with the adhesive layer 2 facing upward, and was irradiated five times with a pulsed laser beam focused on a 50 μm portion of the upper part of the tape, i.e., a portion 50 μm above the surface of the adhesive layer 2 in the thickness direction of the adhesive tape 100.

[0176] The irradiation conditions for the pulsed laser beam applied to the upper 50 μm portion of the adhesive tape 100 were as follows.

[0177] (Irradiation conditions of pulsed laser beam) Light source: Q-switched Nd:YVO4 pulsed laser Wavelength: 355 nm pulsed laser Repetition frequency: 500 kHz Laser intensity: Intensity sufficient to make a 50 μm deep cut in a 125 μm thick PET film (A4130: manufactured by Toyobo Co., Ltd.) with a single irradiation of the pulsed laser beam

[0178] After irradiation with the pulsed laser beam, the adhesive tapes of each Example and Comparative Example were visually inspected for the presence or absence of breakage in the adhesive tape (substrate), and evaluated according to the following criteria.

[0179] (Evaluation criteria) For adhesive tape (substrate): A: 50% or more of the thickness of the substrate remains; B: No obvious breakage is observed; D: Clear breakage is observed, which significantly affects the function of the adhesive tape.

[0180] <Evaluation of Silicon Chip Pickup Property> First, a silicon wafer (manufactured by SUMCO Corporation) made of silicon was prepared and ground by a conventional method to obtain a silicon wafer with a thickness of 130 μm. After that, the silicon wafer was ground to a thickness of 100 μm with a #2000 wheel, and the pressure-sensitive adhesive tape 100 of each Example and Comparative Example was fixed to the ground surface with the pressure-sensitive adhesive layer 2 facing the silicon wafer. Thereafter, the silicon wafer was cut in the thickness direction by irradiation with a pulsed laser beam to obtain individual pieces, thereby obtaining a plurality of silicon chips each measuring 6 mm long x 6 mm wide.

[0181] The irradiation conditions for the pulsed laser beam irradiated onto the silicon wafer were as follows:

[0182] (Irradiation conditions of pulsed laser beam) Light source: Q-switched Nd:YVO4 pulsed laser Wavelength: 355 nm pulsed laser Repetition frequency: 500 kHz

[0183] Thereafter, the adhesive layer 2 was subjected to ultraviolet irradiance of 55 W / cm ２ , UV irradiation amount: 200mj / cm ２ The adhesive layer 2 was cured by applying energy by irradiating it with ultraviolet light under the conditions of (a).

[0184] Next, while the adhesive tape 100 was being expanded radially along its surface, the silicon chip was pushed up using a needle with a tip diameter of 100 μm, with the needle pushing up amount set to 400 μm.

[0185] Next, while the needle was still pushing up the silicon chip, the silicon chip was picked up by suction with a vacuum collet.

[0186] Through the above-described steps, picking up of 50 silicon chips by suction was repeatedly carried out for each adhesive tape of each example and each comparative example.

[0187] Then, for the adhesive tapes of each Example and each Comparative Example, the success or failure of picking up the silicon chip by suction (pickup ability) was evaluated for each obtained silicon chip according to the following criteria.

[0188] (Evaluation criteria) A: 50 silicon chips could be picked up B: 48 to less than 50 silicon chips could be picked up C: 40 to less than 48 silicon chips could be picked up D: Less than 40 silicon chips could be picked The evaluation results obtained as described above are shown in Table 1.

[0189]

[0190] As shown in Table 1, in each example, by satisfying the requirement that the weight loss rate from room temperature to 420°C in the TG curve of the substrate be 50% or less, the occurrence of breakage in the adhesive tape (substrate) was suppressed, and the silicon chip could be picked up with excellent accuracy.

[0191] In contrast, in each comparative example, the weight loss rate from room temperature to 420°C in the TG curve of the substrate did not satisfy the requirement of 50% or less, and as a result, breakage occurred in the adhesive tape (substrate), and as a result, pickup of the silicon chip could not be performed with excellent accuracy.

[0192] According to the present invention, a substrate such as a semiconductor wafer attached to an adhesive tape is cut in the thickness direction by irradiation with a laser beam to separate it into individual pieces, and components such as semiconductor chips are formed on the adhesive tape in a dicing process. This is followed by an expanding process in which the adhesive tape is stretched and a pick-up process in which the components are picked up. This effectively suppresses or prevents breakage of the adhesive tape when the substrate is separated into individual pieces in the adhesive tape used to detach components from the adhesive tape. Therefore, the components can be picked up with excellent precision in the pick-up process. Therefore, the present invention has industrial applicability.

[0193] 2 adhesive layer 4 base material 7 semiconductor substrate 9 wafer ring 10 semiconductor device 17 molded portion 20 semiconductor chip 21 terminal 23 semiconductor chip body portion 25 gap 30 interposer 41 terminal 70 bump 80 sealing layer 81 connection portion 85 solder bump 100 adhesive tape 121 outer periphery 122 center portion 150 light beam irradiator 151 laser beam 200 pickup table 210 center portion 220 outer periphery portion 250 dicer table

Claims

1. An adhesive tape comprising a base material and an adhesive layer laminated on one surface of the base material, the adhesive layer containing a base resin having adhesiveness as a main material, wherein a substrate is fixed on the adhesive layer, and the substrate is irradiated with a laser beam to cut the substrate in its thickness direction and fragment the substrate to form a plurality of components, and then when each component is detached from the adhesive layer, the adhesive tape is used, and the base material has a weight loss rate of 50% or less from room temperature to 420°C in a TG curve obtained by differential thermal-thermogravimetric simultaneous measurement conforming to JIS K 0129.

2. The adhesive tape according to claim 1, wherein the tensile elastic modulus of the base material at 23°C is 200 MPa or less.

3. The adhesive tape according to claim 1, wherein the base material contains a polyolefin resin as a main material.

4. The adhesive tape according to claim 3, wherein the polyolefin resin is a polyethylene resin.

5. The adhesive tape according to claim 4, wherein the polyethylene resin mainly contains a component having a specific gravity of 0.94 or less.

6. The adhesive tape according to claim 1, wherein the base resin is an acrylic resin.

7. The adhesive tape according to claim 6, wherein the adhesive layer further contains a curable resin that cures by the application of energy, and is configured such that the adhesive force to the substrate and the component on the adhesive layer decreases by the application of energy.

8. The adhesive tape according to claim 1, wherein the thickness of the base material is 30 μm or more and 300 μm or less.

9. The adhesive tape according to claim 1, wherein the thickness of the adhesive layer is 5 μm or more and 30 μm or less.

10. The adhesive tape according to claim 1, wherein the detachment of the component from the adhesive layer is carried out by pulling the component out from the opposite side of the base material while stretching the adhesive tape in the plane direction and pushing up the component from the base material side.

Images