Semiconductor device manufacturing method

Abstract

A method for manufacturing a semiconductor device that can improve the flatness of a die rearrangement body is provided. [Solution] A method for manufacturing a semiconductor device includes the steps of: preparing a temporary fixing structure in which a plurality of semiconductor elements, each having a first surface on which connection terminals are formed and a second surface opposite the first surface, are attached to a temporary fixing material; forming a curable adhesive layer on each of the second surfaces of the plurality of semiconductor elements; attaching a carrier to one surface of the curable adhesive layer opposite the plurality of semiconductor elements; curing the curable adhesive layer to fix the plurality of semiconductor elements to the carrier via the cured layer; and removing the temporary fixing material. In the temporary fixing structure, the plurality of semiconductor elements are attached to the temporary fixing material so that the first surfaces of the plurality of semiconductor elements face the temporary fixing material, and the plurality of semiconductor elements are encapsulated with encapsulant so that the second surfaces of the plurality of semiconductor elements are exposed from the encapsulant layer.

Description

[Technical Field]

[0001] The present disclosure relates to a method for manufacturing a semiconductor device. [Background technology]

[0002] Patent Document 1 discloses a heat-peelable adhesive sheet used in the manufacture of semiconductor devices. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-3066532 Summary of the Invention [Problem to be solved by the invention]

[0004] Fan-out packaging is known as one of the methods for manufacturing semiconductor devices. In this fan-out packaging, individual semiconductor chips (dies) are arranged on a separate wafer and sealed to form a rearrangement wafer, after which a redistribution layer (RDL: Re-Distribution Layer) is formed to manufacture each semiconductor device. In this fan-out packaging method, as shown in FIG. 5, for example, when rearranging a semiconductor element 10, the semiconductor element 10 is temporarily attached to a temporary fixing material 120 (see, for example, Patent Document 1) and then sealed. After sealing is completed, the temporary fixing material 120 is removed. However, when the temporary fixing material is removed, warping or distortion may occur in the die rearrangement body (see, for example, FIG. 5(d)) in which the semiconductor element is sealed, which may result in poor flatness of the die rearrangement body.

[0005] The present disclosure aims to provide a method for manufacturing a semiconductor device for improving the planarity of a die rearrangement body. [Means for solving the problem]

[0006] One aspect of the present disclosure relates to a method for manufacturing a semiconductor device. The method for manufacturing a semiconductor device includes the steps of: preparing a temporary fixing structure in which multiple semiconductor elements, each having a first surface on which connection terminals are formed and a second surface opposite the first surface, are attached to a temporary fixing material; forming a curable adhesive layer on each second surface of the multiple semiconductor elements; attaching a carrier to one surface of the curable adhesive layer opposite the multiple semiconductor elements; curing the curable adhesive layer to fix the multiple semiconductor elements to the carrier via the cured curable adhesive layer; and removing the temporary fixing material. In the temporary fixing structure, the multiple semiconductor elements are attached to the temporary fixing material so that the first surfaces of the multiple semiconductor elements face the temporary fixing material, and the multiple semiconductor elements are encapsulated with an encapsulant so that the second surfaces of the multiple semiconductor elements are exposed from the encapsulant layer.

[0007] In this manufacturing method, a carrier is fixed to the surface of the temporary fixing structure opposite the temporary fixing material via a curable adhesive layer. The temporary fixing material is then removed while the carrier is fixed. In this case, the carrier suppresses warping or distortion of the die rearranged body that occurs when the temporary fixing material is removed, thereby improving the flatness of the die rearranged body. By improving the flatness of the die rearranged body as in the above method, for example, when forming a rewiring layer or the like on the connection terminal side of a semiconductor element, it becomes possible to form a finer rewiring layer or the like.

[0008] In the above manufacturing method, the carrier may be a glass substrate, and the adhesive strength of the curable adhesive layer to the glass substrate may be 1 MPa or more when the curable adhesive layer is cured and 5 MPa or less when the curable adhesive layer is irradiated with a laser. If the adhesive strength of the curable adhesive layer to the glass substrate is 1 MPa or more when the curable adhesive layer is cured, the semiconductor element can be more firmly fixed to the carrier, thereby reducing misalignment of the semiconductor element. Furthermore, if the adhesive strength of the curable adhesive layer to the glass substrate is 5 MPa or less when the curable adhesive layer is irradiated with a laser, the carrier can be easily removed by laser irradiation, improving work efficiency.

[0009] In the above manufacturing method, the curable adhesive layer may be formed from a resin composition containing a thermoplastic resin and an epoxy curing agent, and the glass transition temperature of the thermoplastic resin may be between −40°C and 40°C. In this case, it is possible to reduce warpage after the package is completed. The curable adhesive layer may contain a light absorber or have light absorption properties. The light absorber or light absorption properties may absorb light in the wavelength range of 193 nm to 351 nm, which is the wavelength range of an excimer laser, a type of UV laser. Examples of such excimer lasers include a XeF excimer laser (wavelength 351 nm), a XeCl excimer laser (wavelength 303 nm), a KrF excimer laser (wavelength 248 nm), and an ArF excimer laser (wavelength 193 nm). Other UV lasers, such as a YAG laser (3rd harmonic) (wavelength 355 nm) or a YAG laser (4th harmonic) (wavelength 266 nm), may also be used.

[0010] In the above-described manufacturing method, the thickness of the curable adhesive layer after curing may be 1 μm or more and 400 μm or less. When the thickness of the curable adhesive layer is 1 μm or more, the cured curable adhesive layer reliably fixes the carrier to the temporary fixing structure, reliably suppressing warping or distortion of the die rearrangement body when the temporary fixing material is removed, thereby improving its flatness. Furthermore, a curable adhesive layer having such a thickness allows the carrier to reliably hold multiple semiconductor elements, thereby reducing misalignment of the semiconductor elements. On the other hand, when the thickness of the curable adhesive layer is 400 μm or less, it is possible to reduce the height of the manufactured semiconductor device.

[0011] In the above manufacturing method, the carrier is preferably a glass substrate or a transparent resin substrate having a thickness of 0.1 mm to 2.0 mm. In this case, warping or distortion of the die rearrangement body due to the carrier can be more reliably prevented. Furthermore, processes such as forming a rewiring layer can be performed while suppressing misalignment of multiple semiconductor elements held by such a carrier, making it possible to manufacture a semiconductor device with a lower profile and higher precision.

[0012] The manufacturing method may further include a step of forming a redistribution layer on the first surfaces of the semiconductor elements fixed to the carrier while the semiconductor elements are fixed to the carrier. In conventional fan-out methods, the semiconductor elements are attached to the carrier with an adhesive layer or a rigid temporary fixing material is removed midway, which reduces the flatness of the encapsulant and the surfaces of the semiconductor elements encapsulated in the encapsulant, making it difficult to form a fine redistribution layer. In contrast, according to the present manufacturing method, the temporary fixing material is removed while the semiconductor elements remain attached to the carrier, thereby improving the flatness of the surfaces of the encapsulant and the semiconductor elements encapsulated in the encapsulant. Therefore, according to the present manufacturing method, a fine redistribution layer can be formed.

[0013] The manufacturing method may further include a step of attaching solder balls to the connection terminals or rewiring layers of the semiconductor elements while the semiconductor elements are fixed to the carrier. In this case, the solder balls are attached to the semiconductor elements or rewiring layers in a die rearrangement body with improved flatness, so that the solder balls can be attached with high precision.

[0014] The manufacturing method may further include a step of removing the carrier, in which the carrier is a light-transmitting substrate, the curable adhesive layer contains a light absorber, and the removing step preferably involves irradiating the cured curable adhesive layer with laser light from the carrier side to remove the carrier. In this case, the carrier removal process can be simplified. Furthermore, the laser light treatment can also improve the flatness or cleanliness of the surface from which the carrier has been removed.

[0015] In the above manufacturing method, in the removing step, the peeling energy for peeling the carrier is 1 kW / cm 2 More than 200kW / cm 2 The carriers may be removed by irradiating a laser beam as follows. In this case, since the carriers can be removed with low energy, thermal damage to the semiconductor element and the like can be minimized, and the dust generated after the laser irradiation can also be minimized. Furthermore, since the irradiated laser has low energy, the time required for carrier removal can be shortened. Note that the type of laser used for the peeling is not limited.

[0016] The manufacturing method may further include a step of removing the carrier, and in the removing step, the carrier may be removed by scraping or dissolving the carrier.

[0017] The manufacturing method may further include a step of cleaning the exposed surface of either the cured curable adhesive layer or the encapsulant layer after the removing step, in which case the surface of the manufactured semiconductor device can be made cleaner and have a better appearance.

[0018] The manufacturing method may further include a step of singulating the plurality of semiconductor elements after the removing step. In this case, the semiconductor elements are held on the carrier until they are singulated into individual semiconductor devices, and various steps are performed. This eliminates the need for various protective layers (such as BG tape) that have been used in the past, thereby reducing the number of manufacturing steps and manufacturing costs. In this case, the singulation step may involve singulating the cured curable adhesive layer together with the plurality of semiconductor elements, and obtaining a semiconductor device from each of the plurality of semiconductor elements whose second surfaces are protected by the curable adhesive layer.

[0019] In the above manufacturing method, the step of preparing the temporary fixing structure may include the steps of preparing a temporary fixing material, attaching the plurality of semiconductor elements to the temporary fixing material so that the first surfaces of the plurality of semiconductor elements face the temporary fixing material, and sealing the plurality of semiconductor elements with sealing material so that the second surfaces of the plurality of semiconductor elements attached to the temporary fixing material are exposed from the sealing material layer.

[0020] In the manufacturing method, the step of preparing a temporary fixing structure may include preparing a temporary fixing structure in which a plurality of electronic components are attached to a temporary fixing material together with a plurality of semiconductor elements, and the step of fixing may include curing the curable adhesive layer to fix the plurality of electronic components to the carrier. In this case, the flatness of the die rearrangement body including the electronic components is improved, making it possible to manufacture more complex semiconductor devices by a simple method.

[0021] In the above manufacturing method, the adhesive strength between the cured curable adhesive layer and the encapsulant may be 4.0 MPa or more. In this case, the adhesive strength between the curable adhesive layer and the encapsulant can be maintained strong, peeling after package assembly can be prevented, and the curable adhesive layer can function as a part of the final semiconductor device product. In this case, the adhesive strength between the cured curable adhesive layer and the encapsulant may be 8.0 MPa or less. The adhesive strength between the cured curable adhesive layer and the encapsulant may be 20 MPa or more. In this case, the adhesive strength between the curable adhesive layer and the encapsulant can be maintained even stronger, peeling after package assembly can be prevented, and the curable adhesive layer can function as a part of the final semiconductor device product.

[0022] In the above manufacturing method, the adhesive strength between the cured curable adhesive layer and the plurality of semiconductor elements may be 4.0 MPa or more. In this case, the adhesive strength between the curable adhesive layer and the plurality of semiconductor elements (e.g., silicon chips) can be maintained strong, peeling after package assembly can be prevented, and the curable adhesive layer can function as part of the final semiconductor device product.

[0023] In the above manufacturing method, a semiconductor device may be obtained in which the cured curable adhesive layer protects the second surfaces of the respective semiconductor elements, and in this case, the curable adhesive layer can function as a part of the final semiconductor device. [Effects of the Invention]

[0024] According to one aspect of the present disclosure, the planarity of a die rearrangement body can be improved in manufacturing a semiconductor device. [Brief explanation of the drawings]

[0025] [Figure 1] FIG. 1 is a cross-sectional view illustrating an example of a semiconductor device manufactured by a method according to an embodiment of the present disclosure. [Figure 2] 2(a) to 2(d) are diagrams showing a part of a method for manufacturing the semiconductor device shown in FIG. [Figure 3] 3(a) to 3(e) are diagrams showing steps performed subsequent to the step in FIG. 2 in a method for manufacturing the semiconductor device shown in FIG. [Figure 4] 4(a) to 4(e) are diagrams showing steps performed subsequent to the step of FIG. 3 in a method for manufacturing the semiconductor device shown in FIG. [Figure 5] 5(a) to 5(e) are diagrams showing a part of a method for manufacturing a semiconductor device (face down, no support plate). [Figure 6] 6(a) to 6(e) are diagrams showing steps performed subsequent to the step of FIG. 5 in a method for manufacturing a semiconductor device. [Figure 7] 7(a) to 7(d) are diagrams showing steps performed subsequent to the step of FIG. 6 in a method for manufacturing a semiconductor device. DETAILED DESCRIPTION OF THE INVENTION

[0026] Hereinafter, several embodiments of the present disclosure will be described in detail, with reference to the drawings as necessary. However, the present disclosure is not limited to the following embodiments. In the following description, the same or equivalent parts will be given the same reference numerals, and duplicate explanations may be omitted. Positional relationships such as up, down, left, and right will be based on the positional relationships shown in the drawings, unless otherwise specified. The dimensional ratios of the drawings are not limited to those shown in the drawings.

[0027] In this specification, the term "layer" includes not only a structure having a shape formed over the entire surface when observed in a plan view, but also a structure having a shape formed on a portion thereof. In this specification, the term "process" includes not only an independent process, but also a process that cannot be clearly distinguished from other processes as long as the intended effect of the process is achieved.

[0028] In this specification, numerical ranges indicated using "to" indicate ranges that include the numerical values ​​before and after "to" as the minimum and maximum values, respectively. In numerical ranges described in stages in this specification, the upper or lower limit of a numerical range in one stage may be replaced with the upper or lower limit of a numerical range in another stage. In numerical ranges described in this specification, the upper or lower limit of that numerical range may be replaced with a value shown in the examples.

[0029] (Configuration of semiconductor device) FIG. 1 is a cross-sectional view schematically illustrating an example of a semiconductor device manufactured by the manufacturing method according to this embodiment. As shown in FIG. 1, the semiconductor device 1 is, for example, a device having a fan-out structure and includes a semiconductor element 10, an encapsulant layer 11, a protective layer 12, a rewiring layer 13, and solder balls 14. The semiconductor device 1 is manufactured by, for example, fan-out package (FO-PKG) technology, and may be manufactured by, for example, fan-out wafer-level package (FO-WLP) technology or fan-out panel-level package (FO-PLP) technology. The encapsulant layer 11 is a layer in which the semiconductor element 10 is encapsulated with an encapsulant such as resin. The protective layer 12 is a layer that protects the semiconductor element 10 and is a cured layer disposed on the second surface 10b of the semiconductor element 10 and the surface 11a of the encapsulant layer 11. The protective layer 12 is formed by curing a curable adhesive layer 26 (described later) (see FIGS. 2 and 3). The protective layer 12 is fixed to the second surface 10b of the semiconductor element 10 and the encapsulant layer 11 so as not to peel off, and the adhesive strength between the second surface 10b of the semiconductor element 10 and the surface 11a of the encapsulant layer 11 and the protective layer 12 may be, for example, 4.0 MPa or more. The rewiring layer 13 is a layer for widening the terminal pitch of the connection terminals 10c on the first surface 10a side of the semiconductor element 10, and is composed of an insulating portion 13a such as polyimide and a wiring portion 13b such as copper wiring. The solder balls 14 are connected to the terminals whose terminal pitch has been widened by the rewiring layer 13, and as a result, the connection terminals 10c of the semiconductor element 10 are pitch-converted (widened) and connected to the solder balls 14.

[0030] (Method of manufacturing a semiconductor device) Next, a method for manufacturing the semiconductor device 1 will be described with reference to FIGS. 2 to 4. FIGS. 2 to 4 are diagrams sequentially showing the method for manufacturing the semiconductor device 1. In this method for manufacturing a semiconductor device, first, a plurality of semiconductor elements 10 are prepared, each having a first surface 10a on which connection terminals 10c are formed and a second surface 10b opposite to the first surface 10a (see FIGS. 1 and 2(b)). The plurality of semiconductor elements 10 are formed collectively, for example, by a normal semiconductor process, and then separated by dicing to produce each semiconductor element 10. This manufacturing process can be performed using conventional methods, so a description thereof will be omitted.

[0031] As shown in FIG. 2(a), a temporary fixing material 20 is prepared by providing an adhesive layer 20b on a metal carrier 20a. The adhesive layer 20b may be, for example, a release sheet that maintains adhesive strength at room temperature but loses its adhesive strength upon heating. The carrier 20a may have a disk-like wafer shape or a rectangular panel shape in plan view. As shown in FIG. 2(b), multiple semiconductor elements 10 are placed on the adhesive layer 20b of the temporary fixing material 20 so that the first surfaces 10a and connection terminals 10c of the multiple semiconductor elements 10 face down toward the adhesive layer 20b. Then, as shown in FIG. 2(c), the semiconductor elements 10 are encapsulated with an encapsulating resin (encapsulant) such as epoxy to form an encapsulant layer 24. When forming the encapsulant layer 24, encapsulation is performed so that the second surfaces 10b of the semiconductor elements 10 are exposed from the encapsulant layer 24. This forms a temporary fixing structure 22 in which the semiconductor elements 10 are attached to the temporary fixing material 20 with the first surfaces 10a facing the temporary fixing material 20 and the semiconductor elements 10 are sealed with the sealing material so that the second surfaces 10b of the semiconductor elements 10 are exposed from the sealing material layer 24. Note that the temporary fixing structure 22 may be formed by sealing the semiconductor elements 10 with the sealing material and then polishing the sealing material so that the second surfaces 10b are exposed.

[0032] Next, after the temporary fixing structure 22 is formed (prepared), as shown in FIGS. 2(c) and 2(d), a curable adhesive layer 26 is formed on the encapsulant layer 24 where the second surface 10b of the semiconductor element 10 is exposed. Then, as shown in FIG. 3(a), a light-transmitting carrier 28 such as a glass substrate is attached to the curable adhesive layer 26, and the curable adhesive layer 26 is cured by at least one of heat and light to form a cured layer 26a. This fixes the multiple semiconductor elements 10 and the encapsulant layer 24 to the carrier 28 via the cured layer 26a. The adhesive strength between the multiple semiconductor elements 10 and the encapsulant layer 24 and the cured layer 26a at this time may be, for example, 4.0 MPa or more, 20 MPa or more, or 8.0 MPa or less. In this manufacturing method, various processes are subsequently performed on the carrier 28 until the semiconductor elements 10 mounted on the die rearrangement body are singulated again. Therefore, the thickness of the carrier 28 is set to, for example, 0.1 mm or more and 2.0 mm or less. However, the thickness of the carrier 28 is not limited to this. Furthermore, the carrier 28 is preferably a glass substrate, but may be a transparent resin substrate having optical transparency. The carrier 28 may be in the form of a disk-shaped wafer or a rectangular panel.

[0033] The curable adhesive layer 26 can be formed, for example, from a member (curable resin film) formed by forming a resin composition, which is a curable adhesive, into a film. The curable adhesive layer 26 is attached to the encapsulant layer 24 and then cured to fix the plurality of semiconductor elements 10 and the encapsulant layer 24 to the carrier 28. The curable adhesive constituting the curable adhesive layer 26 is an adhesive that cures by at least one of heat and light, and is, for example, a resin composition containing a thermoplastic resin and an epoxy curing agent. The thermoplastic resin contained in this curable adhesive may have a glass transition temperature of −40° C. or higher and 40° C. or lower. Such a curable adhesive layer 26 may be pre-formed so that its thickness after curing is, for example, 1 μm or higher and 400 μm or higher. Furthermore, the curable resin film constituting the curable adhesive layer 26 may have tackiness at 25° C., more specifically, may have tackiness sufficient to be bonded to a glass substrate in a 25° C. environment. The adhesive strength of the curable adhesive layer 26 to the carrier 28 may be configured to be 1 MPa or more when the curable adhesive layer 26 is cured, and 5 MPa or less when the curable adhesive layer 26 is irradiated with a laser.

[0034] The curable adhesive layer 26 is the portion that is heated by laser irradiation in the laser peeling step (see FIG. 4(a)) described below, and the resin composition thereof preferably contains a light-absorbing agent that absorbs laser light. When the curable adhesive layer 26 is a curable resin film containing a light-absorbing agent, the curable adhesive layer 26 has sufficiently low light transmittance. The light-absorbing agent contained in the curable adhesive layer 26 may be a material that absorbs laser light from an excimer laser and generates heat, and may contain, for example, a black pigment or dye. Specific examples of light-absorbing agents include carbon black, aluminum, nickel, and titanium oxide. The content of the light-absorbing agent may be within a range such that the transmittance of the curable resin film constituting the curable adhesive layer 26 for light with a wavelength of 351 nm is 20% or less. Specifically, the content of the light-absorbing agent may be 1% by mass to 30% by mass or 1% by mass to 20% by mass, based on the mass of the curable adhesive layer 26. The transmittance here means the ratio of the intensity of transmitted light to the intensity of incident light when light having a predetermined wavelength is incident on one main surface of the curable adhesive layer 26 .

[0035] The thermoplastic resin constituting the curable adhesive layer 26 may have a reactive group. The reactive group of the thermoplastic resin may be, for example, an epoxy group. The thermoplastic resin may be a (meth)acrylic copolymer or a (meth)acrylic copolymer having a reactive group. In this specification, "(meth)acrylic" is used as a term meaning acrylic or methacrylic. Other similar terms are interpreted similarly.

[0036] The (meth)acrylic copolymer is a copolymer containing, as a monomer unit, a (meth)acrylic monomer having a (meth)acryloyl group. The (meth)acrylic copolymer may be a copolymer containing, as monomer units, a (meth)acrylic monomer that forms a homopolymer having a glass transition temperature of 50°C or higher, a (meth)acrylic monomer that forms a homopolymer having a glass transition temperature of 0°C or lower, and a (meth)acrylic monomer that has an epoxy group. The glass transition temperature of the homopolymer formed by the (meth)acrylic monomer having an epoxy group is not limited. The (meth)acrylic monomer that forms a homopolymer having a glass transition temperature of 50°C or higher and the (meth)acrylic monomer that forms a homopolymer having a glass transition temperature of 0°C or lower may be a monomer that does not have an epoxy group.

[0037] The weight-average molecular weight of the thermoplastic resin constituting the curable adhesive layer 26 may be 200,000 or more and 1,000,000 or less. The weight-average molecular weight here may be a standard polystyrene equivalent value measured by gel permeation chromatography. The content of the thermoplastic resin may be 10% by mass or more and 80% by mass or less, based on the mass of the film constituting the curable adhesive layer 26.

[0038] The curable resin film constituting the curable adhesive layer 26 may further contain a curable resin, which is a compound having a reactive group. The curable resin may be an epoxy resin having two or more epoxy groups, examples of which include bisphenol A epoxy resin, bisphenol F epoxy resin, phenol novolac epoxy resin, and cresol novolac epoxy resin. The molecular weight of the curable resin may be 3000 or less. The curable adhesive layer 26 containing the curable resin is curable and likely to have appropriate tackiness. The content of the curable resin may be 1% by mass or more and 50% by mass or less, based on the mass of the curable resin film constituting the curable adhesive layer 26.

[0039] The curable adhesive layer 26 may further contain a silica filler. The content of the silica filler may be 1% by mass or more and 60% by mass or less, or 5% by mass or more and 60% by mass or less, based on the mass of the film constituting the curable adhesive layer 26.

[0040] The curable adhesive layer 26 may further include a curing agent that reacts with the reactive groups of the thermoplastic resin, the reactive groups of the curable resin, or both. The curing agent may be, for example, a phenolic resin. When the curable adhesive layer 26 includes a curing agent, it may further include a curing accelerator that accelerates the reaction of the curing agent. For example, when the curing agent is a phenolic resin, the curing accelerator may be an imidazole compound.

[0041] Next, after the attachment of the carrier 28 is completed, a step of removing the temporary fixing material 20 from the encapsulant layer 24 in which the plurality of semiconductor elements 10 are encapsulated is performed, as shown in Figures 3(b) and 3(c). In this step, a predetermined amount of heat is applied to the adhesive layer 20b of the temporary fixing material 20, thereby peeling and removing the temporary fixing material 20. By this peeling and removal, the first surfaces 10a of the plurality of semiconductor elements 10 become exposed from the encapsulant layer 24.

[0042] Next, after the temporary fixing material 20 is removed, as shown in FIG. 3(d), with the semiconductor elements 10 fixed to the carrier 28 via the hardened layer 26a, a redistribution layer 30 is formed on the first surfaces 10a of the semiconductor elements 10 fixed to the carrier 28. Note that FIG. 3(d) shows the configuration of FIG. 3(c) upside down. The redistribution layer 30 corresponds to the redistribution layer 13 of the semiconductor device 1 described above and is composed of an insulating layer portion 30a such as polyimide and a wiring portion 30b such as copper wiring within the insulating layer portion 30a. In the redistribution layer 30 formation process, the formation of the insulating layer and the wiring portion are repeated a predetermined number of times to form a wiring layer for pitch conversion. In this manufacturing method, the redistribution layer 30 is formed with the semiconductor elements 10 and the encapsulant layer 24 stably disposed on the carrier 28, making it easy to construct a fine redistribution layer.

[0043] 3(e), with the semiconductor elements 10 fixed to the carrier 28, solder balls 32 are formed so that the connection terminals 10c of the semiconductor elements 10 are connected to the solder balls 32 via the rewiring layer 30. At this time, the pitch of the solder balls 32 is formed to be wider than the terminal pitch of the connection terminals 10c of the semiconductor elements 10. The solder balls 32 correspond to the solder balls 14 in the semiconductor device 1 described above.

[0044] Next, after the solder balls 32 are attached, laser light is irradiated onto the cured layer 26a from the carrier 28 side to perform laser marking on the cured layer 26a, writing necessary information such as the product name, and the carrier 28 is removed from the cured layer 26a by the laser light irradiation, as shown in FIG. 4(a). The laser used to remove the carrier 28 is, for example, an excimer laser, which is a type of UV laser. The carrier 28, which is made of a glass substrate, has a laser light transmittance of 99% or more. More specifically, by irradiating the cured layer 26a with laser light having a wavelength of, for example, 351 nm from the excimer laser, the light absorber in the cured layer 26a is heated, causing the cured layer 26a and the carrier 28 to separate. The wavelength of the laser light irradiated onto the cured layer 26a from the excimer laser may be 532 nm or another wavelength. For example, the laser used here may be an excimer laser such as a XeF excimer laser (wavelength 351 nm), a XeCl excimer laser (wavelength 303 nm), a KrF excimer laser (wavelength 248 nm), or an ArF excimer laser (wavelength 193 nm), or may be other UV lasers such as a YAG laser (triple harmonic) (wavelength 355 nm), a YAG laser (quadruple harmonic) (wavelength 266 nm), etc. The same applies to the lasers used below.

[0045] When removing the carrier 28 from the hardened layer 26a, the peeling energy for peeling the carrier 28 is 1 kW / cm 2 More than 200kW / cm 2The carriers 28 may be removed by irradiating a laser beam as follows. In this case, since the carriers can be removed with low energy, thermal damage to the semiconductor element 10 and the like can be minimized, and the amount of dust generated after laser irradiation can also be minimized. Furthermore, since the irradiated laser has low energy, the time required to remove the carriers can be shortened.

[0046] In the above-described carrier removal process, a method of peeling off the carrier using laser light is used, but the carrier removal method is not limited thereto. For example, the carrier 28 may be scraped off from the cured layer 26a, or the carrier 28 may be dissolved (melted) using a predetermined solvent. The cured layer 26a may also be removed during this removal process. Furthermore, after this removal process, the exposed surface of the cured layer 26a, or if the cured layer 26a has been removed, the exposed surface of the encapsulant layer 24 made of the encapsulant, may be cleaned using a predetermined method. This allows the surface side of the semiconductor device 1, which is the final product, to be cleaner. Note that when the carrier 28 is removed using this method, the carrier 28 does not need to be a light-transmitting substrate, and the curable adhesive layer 26 does not need to contain a light-absorbing agent.

[0047] Next, after the removal of the carrier 28 is completed, as shown in FIG. 4B, a dicing tape 34 is attached to the exposed surface side of the hardened layer 26a to form a wafer-shaped or panel-shaped die rearranged body. Then, as shown in FIGS. 4C and 4D, the die rearranged body is diced at predetermined positions S to separate each portion including the semiconductor element 10 into individual semiconductor devices 1. As a result, multiple semiconductor devices 1 shown in FIG. 4E and FIG. 1 can be obtained from the die rearranged body in which multiple semiconductor elements 10 are rearranged. Note that during the dicing process, the hardened layer 26a is diced together with the semiconductor elements 10, and thus a semiconductor device 1 is obtained from each of the multiple semiconductor elements 10 whose second surfaces 10b are protected by the hardened layer 26a.

[0048] Here, the effects of the manufacturing method of the semiconductor device 1 according to this embodiment will be described in comparison with a comparative example. Figures 5 to 7 are diagrams sequentially explaining a method (face down, no support plate) for manufacturing a semiconductor device having a fan-out structure. The methods shown in Figures 5 to 7 and comparisons therewith will be described.

[0049] As shown in FIG. 5(a), in the comparative example, a temporary fixing material 120 is first prepared by providing an adhesive layer 120b on a metal carrier 120a. The adhesive layer 120b may be, for example, a release sheet that has adhesive strength at room temperature but loses its adhesive strength when heated. Then, as shown in FIG. 5(b), multiple semiconductor elements 10 are placed on the adhesive layer 120b with their first surfaces 10a facing the adhesive layer 120b (i.e., face down). Then, as shown in FIG. 5(c), the semiconductor elements 10 are encapsulated with an encapsulant to form an encapsulant layer 124. After encapsulation is complete, the adhesive layer 120b is heated to peel the adhesive layer 120b from the semiconductor elements 10, and the carrier 120a is removed (see FIG. 5(d)).

[0050] 5(e), a rewiring layer 126 is formed on the first surface 10a of the sealing material layer 124 on which the semiconductor element 10 is exposed. After that, solder balls 128 are formed on the rewiring layer 126, as shown in FIG. 6(a).

[0051] Next, after the solder balls 128 are formed, a protective tape 130 (BG tape) is further attached to protect the solder balls 128, as shown in FIG. 6(b). The protective tape 130 is made of, for example, polyolefin. Then, as shown in FIG. 6(c), with the solder balls 128 protected by the protective tape 130, the encapsulant layer 124 where the second surface 10b of the semiconductor element 10 is exposed is polished to form an encapsulant layer 124a. Thereafter, as shown in FIGS. 6(d) and 6(e), a dicing tape 132b is attached via a BSC film 132a, and the protective tape 130 is removed in this state. The BSC film 132a is made of, for example, epoxy resin. Note that an integrated tape 132 is used for the BSC film 132a and dicing tape 132b. After the removal of the protective tape 130 is completed, laser marking is performed on the BSC film 132a with a laser beam to write necessary information such as the product name, as shown in (a) of Fig. 7. The BSC film 132a forms part of the semiconductor device. Thereafter, as shown in (b) to (d) of Fig. 7, each portion including the semiconductor element 10 is diced into individual pieces to obtain each semiconductor device 101.

[0052] As described above, in the comparative example, the temporary fixing material 120 lacks heat resistance and chemical resistance. Therefore, as shown in FIGS. 5(c) and 5(d), the temporary fixing material 120 is removed early from the die rearranged body in which the semiconductor element 10 is encapsulated with an encapsulant. During this removal, the encapsulant layer 124 is not fixed on the opposite side by a carrier or the like, and therefore warping or distortion may occur due to the heat or force applied during removal. When attempting to form a rewiring layer 126 on such a warped encapsulant layer 124, the warping or distortion may make it difficult to form a fine wiring layer. In contrast, in the method according to the present embodiment, the other side of the encapsulant layer 24 is fixed by a carrier 28, as shown in FIGS. 3(a) and 3(b). Therefore, the manufacturing method according to the present embodiment reduces warping or distortion during removal of the temporary fixing material 20 compared to the comparative example, thereby improving the flatness of the die rearranged body. As a result, according to this manufacturing method, when the rewiring layer 30 is to be formed on the sealing material layer 24, it is possible to form a fine wiring layer.

[0053] Furthermore, in the method of the comparative example, as shown in FIGS. 5(d) to 6(b), the back surface of the die rearrangement body on which the multiple semiconductor elements 10 are arranged (e.g., the encapsulant layer 124) is made of epoxy resin and remains exposed, which may contaminate the process. Furthermore, chemicals used in the process may leach out the epoxy resin components, which may affect the yield of copper wiring and the like in the plating process (wiring formation) in the rewiring layer 126. In contrast, in the method of the present embodiment, as shown in FIGS. 3(d) and 3(e), the carrier 28 continuously covers the back surface of the die rearrangement body during each process, thereby preventing the above-mentioned contamination or leaching. In other words, the method of the present embodiment allows the process of manufacturing the semiconductor device 1 to be maintained in a highly clean state.

[0054] Furthermore, in the method of the comparative example, as shown in Figures 5(e) to 6(c), the back surface of the die rearrangement body on which the semiconductor elements 10 are rearranged is made of epoxy resin, which may contaminate the equipment environment, etc., and therefore, it is necessary to provide equipment, etc., separate from the case, manufacturing equipment, and conveying / suction mechanism used in manufacturing a fan-in wafer-level package (WLP) whose back surface is made of silicon or the like. In contrast, in the manufacturing method of this embodiment, as shown in Figures 3(d) and 3(e), a carrier 28 made of glass or the like covers the back surface of the die rearrangement body during each process, thereby preventing the above-mentioned contamination, etc. As a result, the manufacturing method of this embodiment makes it possible to manufacture semiconductor devices with a fan-out structure, such as a FO-WLP, using the same manufacturing equipment, etc., as for a fan-in WLP.

[0055] 6(b) and 6(c), the method of the comparative example further uses a protective tape 130 to protect the solder balls 128 when the encapsulant layer 124 is polished so that the second surface 10b of the semiconductor element 10 is exposed. In contrast, in the manufacturing method of the present embodiment, as shown in FIGS. 2(b) to 2(d), when the semiconductor element 10 is encapsulated with an encapsulant, the encapsulant layer 24 is pre-formed to a predetermined thickness, and a curable adhesive layer 26 is formed thereon. Therefore, the manufacturing method of the present embodiment can reduce the number of components used compared to the method of the comparative example, and can also reduce the number of component attachment and removal steps, thereby simplifying the process of manufacturing the semiconductor device 1.

[0056] Furthermore, in the comparative example, as shown in FIG. 6(d), an integrated tape 132 in which a dicing tape 132b and a BSC film 132a are integrated after polishing may be used. This integrated tape 132 often has insufficient adhesive residue, dicing properties, and pickup properties, making it difficult to reduce the height of the semiconductor device 1. In contrast, in the method according to the present embodiment, as shown in FIG. 3(a), the curable adhesive layer 26 used to secure the semiconductor element 10 to the carrier 28 is used directly in the semiconductor device 1. This eliminates the need for such an integrated product, and allows for the use of a separate dicing tape. Therefore, a dicing tape suitable for reducing the height can be used to reduce the height of the semiconductor device.

[0057] As described above, the manufacturing method according to this embodiment can simplify the process of manufacturing the semiconductor device 1 having a fan-out structure compared to the method of the comparative example. Also, warping or distortion of the encapsulant layer 24 that encapsulates the semiconductor element 10 can be suppressed, improving flatness and forming a fine redistribution layer 30. Furthermore, by forming a fine redistribution layer 30, it is possible to reduce the height of the semiconductor device 1.

[0058] In the manufacturing method according to the present embodiment, the adhesive strength between the cured curable adhesive layer (cured layer 26a) and the encapsulant layer 24 may be 4.0 MPa or more. In this case, the adhesive strength between the cured layer 26a and the encapsulant layer 24 can be maintained strong, peeling after package assembly can be prevented, and the cured layer 26a can function as part of the final product of the semiconductor device 1 (protective layer 12) as it is. In this case, the adhesive strength between the cured layer 26a and the encapsulant layer 24 may be 8.0 MPa or less. The adhesive strength between the cured layer 26a and the encapsulant layer 24 may be 20 MPa or more. In this case, the adhesive strength between the cured layer 26a and the encapsulant layer 24 can be maintained stronger, peeling after package assembly can be prevented, and the cured layer 26a can function as part of the final product of the semiconductor device 1 (protective layer 12) as it is.

[0059] Furthermore, in the manufacturing method according to this embodiment, the adhesive strength between the cured curable adhesive layer (cured layer 26a) and the plurality of semiconductor elements 10 may be 4.0 MPa or more. In this case, the adhesive strength between the cured layer 26a and the plurality of semiconductor elements 10 (e.g., silicon chips) can be maintained strong, peeling after package assembly can be prevented, and the cured layer 26a can function as a part of the final product of the semiconductor device 1.

[0060] Furthermore, in the manufacturing method according to this embodiment, the semiconductor device 1 may be obtained in a state in which the cured curable adhesive layer (cured layer 26a) protects the second surface 10b of each of the multiple semiconductor elements 10. In this case, the cured layer 26a used in the manufacturing can function as part of the final product of the semiconductor device 1 (protective layer 12) as it is.

[0061] Although the embodiments of the present disclosure have been described in detail above, the present disclosure is not limited to the above embodiments and can be applied to various other embodiments. For example, in the above embodiment, a method for manufacturing a semiconductor device 1 including a semiconductor element 10 was described. However, the present disclosure may also be applied to a semiconductor device or a method for manufacturing such a device that includes multiple electronic components in addition to or instead of the semiconductor element 10. In this case, in the attachment step shown in FIG. 2(b), multiple electronic components are attached to a temporary fixing material 20 along with the multiple semiconductor elements 10. In the step shown in FIG. 2(c), the multiple electronic components are encapsulated together with the semiconductor elements 10 with an encapsulant. In the steps shown in FIG. 2(d) and FIG. 3(a), the curable adhesive layer 26 is cured to fix the multiple electronic components together with the semiconductor elements 10 to a carrier 28. Other steps can be similar to those described above. This manufacturing method allows for the formation of more complex semiconductor devices and the like. The electronic components referred to here may be, for example, passive elements such as capacitors or resistors, or components such as MEMS. [Example]

[0062] The present invention will be described in more detail below with reference to examples. However, the present invention is not limited to these examples. The following examples will explain the adhesive strength between the curable adhesive layer 26 (cured cured layer 26a, protective layer 12) and the encapsulant layer 24 used in the semiconductor device manufacturing method according to the above-described embodiment, and the peel energy of the glass substrate (carrier 28) from the cured layer 26a. The adhesive strength between the cured layer 26a and the encapsulant layer 24 can be applied to the adhesive strength between the cured layer 26a and the semiconductor element 10.

[0063] The following raw materials for the curable adhesive layer were prepared. [Thermoplastic resin] Acrylic polymer with epoxy groups: (glass transition temperature: 12°C) [Epoxy resin] Bisphenol F liquid epoxy resin: YDF-8170C (product name, Nippon Steel Chemical & Material Co., Ltd.) Cresol novolac epoxy resin: N-500P-10 (product name, DIC Corporation) [Hardening agent] Phenolic resin: PSM-4326 (product name, Gun-ei Chemical Industry Co., Ltd.) Phenolic resin: MEH-7800M (product name, Meiwa Kasei Co., Ltd.) [Silica filler] SC2050-HLG (product name, Admatechs Co., Ltd.) R972 (product name, Nippon Aerosil Co., Ltd.) [Light absorber] Carbon black: FP-Black (product name, Sanyo Pigment Co., Ltd.) [Coupling agent] (3-Mercaptopropyl)trimethoxysilane: A-189 (trade name, Momentive) 3-Ureidopropyltriethoxysilane: A-1160 (trade name, Momentive) [Curing accelerator] 1-Cyanoethyl-2-phenylimidazole: 2PZ-CN (trade name, Shikoku Chemicals Corporation)

[0064] Next, a resin varnish containing each raw material in the blending ratio shown in Table 1 below and cyclohexanone as a solvent was prepared as a material for the curable adhesive layer. The total concentration of components other than the solvent in the resin varnish was 40 mass% based on the mass of the varnish.

[0065] [Table 1]

[0066] Each varnish was applied to a support film and the coating was dried to form a curable resin film on the support film. A protective film was placed on the curable resin film to obtain Film A or B, which was composed of the support film, curable resin film, and protective film. The curable resin film was adjusted to have a thickness of 20 μm when cured.

[0067] [Evaluation of adhesion with encapsulant] A 12-inch glass substrate (700 μm thick) was cut into 9 mm × 9 mm pieces using a blade dicer (product name: DAD3360, manufactured by DISCO Corporation). The protective film was peeled off from Film A or Film B, and the exposed curable resin film was placed on a 9 mm × 9 mm glass substrate. Film A or B was then placed on the glass substrate, and the curable resin film and glass substrate were bonded together using a vacuum laminator (product name: V-130, manufactured by Nikko Materials Co., Ltd.). The vacuum laminator conditions were: upper platen temperature 90°C, lower platen temperature 40°C, pressure 0.5 MPa, and pressure time 60 seconds.

[0068] Next, after the attachment was completed, the curable resin film was cured under various conditions using an atmospheric oven (product name, PHH-202, manufactured by Espec Corporation) or a nitrogen oven (product name, CLH-21CD, manufactured by Koyo Thermo Co., Ltd.). On the protective layer, which was the cured curable resin film, an encapsulant (product name, CEL-400ZHF40, manufactured by Showa Denko Materials Co., Ltd.) and a molding device (product name, ADM-12, manufactured by Meiho Co., Ltd.) were used to form an encapsulant (encapsulant layer) on the protective layer. The adhesive area between the encapsulant and the protective layer was 10 mm.2 The molding conditions were a sealing temperature of 130°C and a curing time of 600 seconds. The formed sealed body was heated in an oven at 175°C for 4 hours to further harden the sealed body. This yielded a laminate for evaluation consisting of a glass substrate, a protective layer, and a sealed body.

[0069] Next, a bond tester (product name: System 650, manufactured by ROYCE Instruments) was used to scan a shearing jig parallel to the main surface of the glass substrate, and the shear stress obtained by ejecting the formed sealant was measured as the adhesive strength between the sealant and the protective layer. The adhesive area between the sealant and the protective layer was 10 mm 2 The operating speed of the shearing jig was set to 50 μm / s, and the clearance was set to 100 μm based on the protective layer formed on the glass substrate. Tables 2 and 3 show the results of the adhesive strength under the protective layer curing conditions for each example. The adhesive strength with the sealing body shown in Tables 2 and 3 below is the average value of 10 tests conducted for each example. The temperature when measuring the adhesive strength was room temperature (25°C). The adhesive strength in this specification was measured using the above method.

[0070] [Table 2]

[0071] [Table 3]

[0072] As shown in Tables 2 and 3 above, it was confirmed that by setting the curing conditions for the protective layer within a predetermined range, the cured layer serving as the protective layer can be bonded to the sealant layer at 4.0 MPa or more. Similarly, it was confirmed that the cured layer serving as the protective layer can be bonded to the sealant layer at 20 MPa or more.

[0073] [Laser peeling test] Next, Film A and Film B were prepared in the same manner as in the tests of Examples 1 to 8 described above. The protective film was peeled off from Film A or Film B, and the exposed curable resin film was placed on a glass substrate (60 mm × 60 mm, 700 μm thick). The curable resin film and glass substrate were then bonded together using a vacuum laminator (product name: V-130, manufactured by Nikko Materials Co., Ltd.). The vacuum laminator conditions were an upper platen temperature of 90°C, a lower platen temperature of 40°C, a pressure of 0.5 MPa, and a pressure time of 60 seconds. The curable resin film was cured in an oven by heating at 130°C for 20 minutes, followed by heating at 170°C for 2 hours. An encapsulant layer was formed on the cured curable resin film protective layer using an encapsulant containing epoxy resin and a molding device (product name: CPM1080, manufactured by TOWA Corporation) at 150°C for 300 seconds. The formed encapsulant layer was further cured by heating at 150°C for 6 hours. As a result, a laminate for evaluation having a three-layer structure consisting of a glass substrate, a protective layer, and a sealing material layer was obtained.

[0074] The evaluation laminate was irradiated with UV laser light having a wavelength of 355 nm in a direction perpendicular to the glass substrate to peel off the glass substrate. After irradiation, the sealant layer with protective layer and the glass substrate were easily peeled off from each other as A, and the sealant layer was peeled off by making an incision with a cutter as B. The peeling results under each UV laser light irradiation condition are shown in Tables 4 and 5. Note that the laser light irradiation did not cause a decrease in the adhesive strength between the protective layer and the sealant layer.

[0075] [Table 4]

[0076] [Table 5]

[0077] As shown in Tables 4 and 5 above, the peeling energy when peeling the glass substrate as a carrier from the encapsulant layer with the protective layer was set to 1 kW / cm 2 More than 200kW / cm 2It was confirmed that the film could be peeled off by placing it in the following position. [Explanation of symbols]

[0078] 1...semiconductor device, 10...semiconductor element, 10a...first surface, 10b...second surface, 10c...connection terminal, 20...temporary fixing material, 22...temporary fixing structure, 24...sealing material layer, 26...curable adhesive layer, 26a...cured layer, 28...carrier, 30...rewiring layer, 32...solder ball, 34...dicing tape.

Claims

1. a step of preparing a temporary fixing structure in which a plurality of semiconductor elements, each having a first surface on which a connection terminal is formed and a second surface opposite to the first surface, are attached to a temporary fixing material, wherein in the temporary fixing structure, the first surfaces of the plurality of semiconductor elements are attached to the temporary fixing material so as to face the temporary fixing material, and the plurality of semiconductor elements are encapsulated with an encapsulant so that the second surfaces of the plurality of semiconductor elements are exposed from an encapsulant layer; forming a curable adhesive layer on the second surface of each of the plurality of semiconductor elements; bonding a carrier to one surface of the curable adhesive layer opposite the plurality of semiconductor elements; curing the curable adhesive layer to fix the semiconductor elements to the carrier via the cured curable adhesive layer; removing the temporary fixing material; removing the carrier; The method for manufacturing a semiconductor device includes:

2. The adhesive strength of the curable adhesive layer to the carrier is 1 MPa or more when the curable adhesive layer is cured, and is 5 MPa or less when the curable adhesive layer is irradiated with a laser. The method for manufacturing a semiconductor device according to claim 1 .

3. the curable adhesive layer is formed from a resin composition containing a thermoplastic resin and an epoxy curing agent, and the thermoplastic resin has a glass transition temperature of −40° C. or higher and 40° C. or lower; The method for manufacturing a semiconductor device according to claim 1 or 2.

4. The thickness of the curable adhesive layer after curing is 1 μm or more and 400 μm or less. The method for manufacturing a semiconductor device according to any one of claims 1 to 3.

5. The method further comprises forming a redistribution layer on the first surfaces of the plurality of semiconductor elements fixed to the carrier. The method for manufacturing a semiconductor device according to any one of claims 1 to 4.

6. In the step of removing the carrier, the cured curable adhesive layer is irradiated with an excimer laser to remove the carrier. The method for manufacturing a semiconductor device according to any one of claims 1 to 5.

7. The excimer laser is at least one of a XeF excimer laser, a XeCl excimer laser, a KrF excimer laser, and an ArF excimer laser. The method for manufacturing a semiconductor device according to claim 6 .

8. The curable adhesive layer includes a light absorber that absorbs laser light from an excimer laser. The method for manufacturing a semiconductor device according to any one of claims 1 to 7.

9. The content of the light absorber is 30 mass% or less based on the mass of the curable adhesive layer. The method for manufacturing a semiconductor device according to claim 8 .

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