Manufacturing method of electronic component device

Abstract

To provide a manufacturing method of an electronic component device, capable of suppressing adhesion of a foreign material to a circuit surface of a manufactured substrate chip.SOLUTION: A manufacturing method of an electronic component device, contains: a step of overlapping a protective sheet for protecting a circuit structure element to a circuit surface which is at least one surface of a substrate and in which the circuit surface element is arranged; a step of manufacturing a small piece of a lamination material in which a substrate chip obtained by minimizing the substrate and a small piece 10' of the protective sheet are overlapped by dividing and minimizing the lamination material to which the substrate and the protective sheet are overlapped to a surface direction so as to have an interval; and a step of removing the small piece of the protective sheet overlapped to the circuit surface of the substrate chip.SELECTED DRAWING: Figure 3H

Description

[Technical Field]

[0001] The present invention relates to a method for manufacturing electronic component devices, such as semiconductor devices having semiconductor integrated circuits. [Background technology]

[0002] Conventionally, a method for manufacturing electronic components is known, which is used when manufacturing semiconductor devices having semiconductor integrated circuits. In this type of electronic component manufacturing method, for example, a semiconductor wafer as a substrate is attached to a dicing tape having a base layer and an adhesive layer, and the dicing tape is stretched to increase its area, thereby dividing the semiconductor wafer into small pieces of semiconductor chips. Then, the semiconductor chips, which are the small pieces of substrate, are adhered to a substrate.

[0003] Generally, the manufacturing method for this type of electronic component device comprises a pre-process of forming a circuit surface on one side of a wafer by arranging highly integrated circuit components on that side, and a post-process of cutting out chips from the wafer on which the circuit surface has been formed and assembling them.

[0004] In the subsequent process, for example, a fragile area is formed on the wafer (semiconductor wafer) with the circuit surface formed on it, in order to break it into smaller chips (dies), and the adhesive layer of dicing tape is attached to the side opposite to the circuit surface. Then, while the semiconductor wafer is attached to the adhesive layer of the dicing tape, the dicing tape is stretched in the planar direction, thereby breaking the semiconductor wafer into smaller semiconductor chips using the fragile area as the boundary. After that, the broken semiconductor chips are peeled off from the adhesive layer of the dicing tape.

[0005] The post-processing steps described above include, for example, a stealth processing step in which a fragile area is formed on the wafer using laser light or the like to break down the wafer into smaller chips (dies); a mounting step in which the semiconductor wafer is fixed by attaching the side of the semiconductor wafer opposite to the circuit side to a dicing tape; an expanding step in which the semiconductor wafer is broken down into semiconductor chips (dies) by stretching the dicing tape in the plane direction; a pick-up step in which the semiconductor chip is peeled off and removed from the adhesive layer; and a bonding step in which the removed semiconductor chip is bonded to a substrate. Semiconductor integrated circuits are manufactured, for example, through these steps.

[0006] In the manufacturing method of electronic component devices as described above, for example, in the bonding process, the semiconductor chip is placed on the workpiece with its circuit side facing outwards, and the two are bonded together (so-called flip-chip bonding).

[0007] As a method for manufacturing this type of electronic component device, for example, a method is known in which the semiconductor chip and the adherend are electrically connected via bumps protruding from the circuit surface of the semiconductor chip and a conductive material (solder, etc.) on the surface of the adherend. Specifically, as a method for manufacturing this type of electronic component device, a method is known in which a specific underfill material is placed between the semiconductor chip and the adherend, and the electrode portion placed on the circuit surface of the semiconductor chip is electrically connected to the electrode portion of the adherend (for example, Patent Document 1).

[0008] More specifically, the method for manufacturing an electronic component device described in Patent Document 1 is a method for manufacturing an electronic component device comprising a substrate, a semiconductor element electrically connected to the substrate, and an underfill material that fills the space between the substrate and the semiconductor element, A step of preparing a semiconductor element with an underfill material, wherein a specific underfill material is bonded to the semiconductor element, The process includes a connection step of electrically connecting the semiconductor element and the adherend while filling the space between the semiconductor element and the adherend with the underfill material. More specifically, the aforementioned underfill material has a melt viscosity of 50 Pa·s or more and 3000 Pa·s or less at 150°C before heat treatment. When the melt viscosity at 150°C before the aforementioned heat treatment is denoted as η1, and the melt viscosity at 150°C after heat treatment at 130°C for 1 hour is denoted as η2, the viscosity change rate [(η2 / η1)×100] is 500% or less. The reaction rate {[(Qt-Qh) / Qt]×100} is 90% or higher, where Qt is the total heat generated during the heating process from -50°C to 300°C in DSC measurement, and Qh is the total heat generated during the heating process from -50°C to 300°C after heating at 175°C for 2 hours.

[0009] According to the method for manufacturing electronic component devices described in Patent Document 1, since the electronic component devices are manufactured using an underfill material having a specific viscosity change rate, melt viscosity, and reaction rate, it is possible to improve manufacturing efficiency. [Prior art documents] [Patent Documents]

[0010] [Patent Document 1] Japanese Patent Publication No. 2015-170754 [Overview of the project] [Problems that the invention aims to solve]

[0011] Incidentally, in the bonding process described above, there are cases where bonding is performed in a way that reduces the gap between the adherend and the semiconductor chip. For example, a semiconductor chip already bonded to a substrate may be used as the adherend, and further semiconductor chips may be bonded to this semiconductor chip, and the same flip-chip bonding process described above may be repeated to stack semiconductor chips. In this case, for example, the electrode portions of adjacent semiconductor chips may be directly connected. In particular, when the electrode portions are directly connected in this way, the gap between the semiconductor chips becomes almost nonexistent, so if foreign matter is attached to the circuit surface of the semiconductor chip, it may become difficult to achieve reliable bonding. This type of foreign matter can occur, for example, when dicing a semiconductor wafer serving as a substrate into small pieces as described above. A part of the semiconductor wafer becomes minute pieces and can adhere to the circuit surface of a semiconductor chip or the like. Therefore, there is a demand for a method of manufacturing an electronic component device capable of suppressing the adhesion of this type of foreign matter to the circuit surface of a substrate chip such as a semiconductor chip. In addition, when a large amount of foreign matter adheres to the circuit surface of a substrate chip such as a semiconductor chip, the reliability of the electronic component device composed of the substrate chip with a large amount of foreign matter adhering thereto may be reduced regardless of whether the bonding step as described above is performed or not.

[0012] However, it cannot be said that a method of manufacturing an electronic component device capable of suppressing the adhesion of foreign matter to the circuit surface of a diced substrate chip has been sufficiently studied yet.

[0013] Therefore, an object of the present invention is to provide a method of manufacturing an electronic component device capable of suppressing the adhesion of foreign matter to the circuit surface of a produced substrate chip.

Means for Solving the Problem

[0014] In order to solve the above problems, a method of manufacturing an electronic component device according to the present invention includes: a step of overlaying a protective sheet for protecting the circuit components on the circuit surface on at least one surface of the substrate where the circuit components are arranged; a step of producing a small piece of the laminate in which the small substrate chip obtained by dicing the substrate and the small piece of the protective sheet overlap by dividing the laminate in which the substrate and the protective sheet overlap in the plane direction with a space therebetween; a step of removing the small piece of the protective sheet overlapping the circuit surface of the substrate chip.

[0015] According to the above-described method for manufacturing electronic component devices, a protective sheet is placed on the side of the substrate where the circuit components are arranged (hereinafter also referred to as the circuit side), thereby preventing foreign matter from adhering to the circuit side until the protective sheet is removed. Specifically, when the substrate is divided into smaller pieces while the substrate and protective sheet are overlapping, it is possible to prevent foreign matter such as fragments that may be generated during the division from adhering to the circuit side of the substrate chip. Even if foreign matter is adhering to the circuit side of the substrate chip before the protective sheet is placed on top, that foreign matter can also be removed when the small piece of protective sheet is removed. Therefore, it is possible to suppress the adhesion of foreign matter to the circuit surface of the manufactured substrate chip.

[0016] The above-described method for manufacturing an electronic component device may further include the step of arranging the circuit surface of the substrate chip toward the adherend and joining the substrate chip and the adherend. This method of manufacturing electronic components can suppress adverse effects caused by foreign matter that gets trapped between the circuit surface of the substrate chip and the adherend.

[0017] In the above method for manufacturing an electronic component device, the protective sheet contains a water-soluble polymer compound. In the removal step described above, the multiple small pieces of the protective sheet may be removed by bringing a liquid containing water into contact with the multiple small pieces of the protective sheet and dissolving at least a portion of each small piece in the liquid. According to this method for manufacturing electronic components, the liquid can not only remove small pieces of the protective sheet, but also reduce the amount of foreign matter adhering to the circuit surface of the substrate chip. Furthermore, the liquid can be used to clean the circuit surface of the substrate chip.

[0018] In the above-described method for manufacturing an electronic component device, in the removal step, the multiple small pieces of the protective sheet may be removed together with the adhesive tape by peeling off the adhesive tape attached to the multiple small pieces of the protective sheet. According to this method of manufacturing electronic component devices, the protective sheet can be removed relatively easily.

[0019] In the above method for manufacturing an electronic component device, the protective sheet contains a curable composition. The protective sheet overlapping the substrate may be cured by a curing process, and then the laminate of the substrate and the protective sheet may be divided into smaller pieces. According to this method for manufacturing electronic component devices, the protective sheet hardens due to the hardening process, making it easier to divide and break it into smaller pieces. Furthermore, the protective sheet can be removed more easily using adhesive tape for peeling.

[0020] In the above-described method for manufacturing an electronic component device, the electrode portions, which are circuit components, arranged on both surfaces of the substrate chip are electrically connected to each other. In the bonding step, at least two of the substrate chips may be stacked, and the electrode portion of one of the substrate chips that is the adherend and the electrode portion of the other substrate chip may be directly connected to each other. According to this method of manufacturing electronic components, since substrate chips in which the adhesion of foreign matter to the circuit surface is suppressed are stacked, the number of foreign matter particles that can get between one stacked substrate chip and the other can be reduced. Therefore, the electrode portions between adjacent substrate chips can be connected to each other more reliably. As a result, the circuits of multiple substrate chips are electrically connected to each other with high reliability. [Effects of the Invention]

[0021] According to the method for manufacturing electronic component devices of the present invention, it is possible to suppress the adhesion of foreign matter to the circuit surface of the manufactured substrate chip. [Brief explanation of the drawing]

[0022] [Figure 1A] A cross-sectional view of an example of a circuit board, cut in the thickness direction. [Figure 1B] A schematic cross-sectional view illustrating an example of the wetting process. [Figure 1C] A schematic cross-sectional view illustrating an example of the protection process. [Figure 1D] A schematic cross-sectional view illustrating an example of the protection process. [Figure 1E] A schematic cross-sectional view showing an example of the state of a laminate of substrate and protective sheet before it is broken down into smaller pieces. [Figure 1F] A schematic cross-sectional view showing an example of what happens when a laminate of substrates and protective sheets is broken down into smaller pieces. [Figure 1G] A schematic cross-sectional view illustrating an example of how to remove a small piece of protective sheet that is overlapping a small piece of circuit board. [Figure 2A] A cross-sectional view of an example of a protective sheet and release liner, cut in the thickness direction. [Figure 2B] A cross-sectional view of an example of dicing tape, cut in the thickness direction. [Figure 2C] A cross-sectional view of an example of a semiconductor wafer used as a substrate, cut in the thickness direction. [Figure 2D] A cross-sectional view of an example of a semiconductor chip fabricated by dividing a semiconductor wafer used as a substrate, shown in the thickness direction. [Figure 3A] A schematic cross-sectional view showing the state before the mounting process in the first embodiment. [Figure 3B] A schematic cross-sectional view illustrating the mounting process in the first embodiment. [Figure 3C] A schematic cross-sectional view illustrating the mounting process in the first embodiment. [Figure 3D] A schematic cross-sectional view illustrating the wetting process in the first embodiment. [Figure 3E] A schematic cross-sectional view illustrating the protection process in the first embodiment. [Figure 3F] A schematic cross-sectional view showing the stealth processing step in the first embodiment. [Figure 3G] A schematic cross-sectional view showing the expansion process in the first embodiment. [Figure 3H] A schematic cross-sectional view illustrating the removal process in the first embodiment. [Figure 3I] A schematic cross-sectional view illustrating the pickup process in the first embodiment. [Figure 3J] A schematic cross-sectional view illustrating the joining process in the first embodiment. [Figure 4A] A schematic cross-sectional view illustrating the mounting process in the second embodiment. [Figure 4B] A schematic cross-sectional view showing the stealth processing step in the second embodiment. [Figure 4C] A schematic cross-sectional view showing the curing process of the protective sheet in the second embodiment. [Figure 4D] A schematic cross-sectional view showing the state after the protective sheet has been cured and the release liner has been peeled off, according to the second embodiment. [Figure 4E] A schematic cross-sectional view showing the expansion process in the second embodiment. [Figure 4F] A schematic cross-sectional view illustrating the removal process in the second embodiment. [Figure 5A] A schematic cross-sectional view showing the semiconductor wafer and backgrind tape in the third embodiment. [Figure 5B] A schematic cross-sectional view illustrating the protection process in the third embodiment. [Figure 5C] A schematic cross-sectional view showing the state before the mounting process in the third embodiment. [Figure 5D] A schematic cross-sectional view illustrating the mounting process in the third embodiment. [Figure 6A] A schematic cross-sectional view showing the semiconductor wafer and backgrind tape in the fourth embodiment. [Figure 6B] A schematic cross-sectional view showing the stealth processing step in the fourth embodiment. [Figure 6C] A schematic cross-sectional view illustrating the protection process in the fourth embodiment. [Figure 6D] A schematic cross-sectional view showing the situation before the mounting process in the fourth embodiment. [Figure 6E] A schematic cross-sectional view illustrating the mounting process in the fourth embodiment. [Figure 6F] A schematic cross-sectional view showing the curing process of the protective sheet in the fourth embodiment. [Figure 7A] A schematic cross-sectional view showing the grinding process in the fifth embodiment. [Figure 7B] A schematic cross-sectional view showing the state after grinding in the fifth embodiment. [Figure 7C] A schematic cross-sectional view showing the state after the mounting process in the fifth embodiment. [Figure 7D] A schematic cross-sectional view showing the state after the stealth processing step in the fifth embodiment. [Figure 8] A photograph showing the surface of a semiconductor chip manufactured by the manufacturing method of Example 1. [Figure 9] A photograph showing the surface of a semiconductor chip manufactured using the comparative example manufacturing method. [Modes for carrying out the invention]

[0023] Hereinafter, embodiments of the method for manufacturing an electronic component device according to the present invention will be described with reference to the drawings.

[0024] The method for manufacturing the electronic component device of this embodiment is: A step of placing a protective sheet 10 to protect the circuit components on at least one side of the substrate, which is the circuit surface on which the circuit components are arranged (protection step), The process involves dividing the laminate, in which the substrate and the protective sheet 10 overlap, into smaller pieces with spacing in the planar direction, thereby producing small pieces of the laminate in which the substrate chips and the small pieces of the protective sheet 10 overlap (expanding process), The process includes a step of removing small pieces of the protective sheet 10 that overlap the circuit surface of the substrate chip (removal step). The manufacturing method of the electronic component device of this embodiment may further include a step of arranging the circuit surface of the substrate chip toward the adherend and joining the substrate chip and the adherend (joining step).

[0025] The manufacturing method of the electronic component device of this embodiment may further include a step of increasing the humidity of the gas in contact with the circuit surface Sa (wetting step) before superimposing the protective sheet onto the circuit surface.

[0026] In the method for manufacturing an electronic component device according to this embodiment, at least one side of the substrate is protected by a protective sheet 10. The protected side (the circuit side Sa on which the circuit components are arranged) may be only one side of the substrate or both sides.

[0027] As shown in the cross-sectional view of Figure 1A, the substrate S is not particularly limited in material as long as it is in the form of a plate. Examples of substrates include semiconductor wafers, substrates that constitute CMOS (Complementary Metal Oxide Semiconductor) or MEMS (Micro Electro Mechanical Systems), substrates that constitute pseudo-wafers, or wiring boards. Furthermore, circuit components are arranged on at least one side of the substrate. The side of the substrate on which the circuit components are arranged is the circuit side. Examples of circuit components include wiring, electrodes, or elements such as transistors, diodes, or sensors (such as light sensors or vibration sensors). The circuit surface protected by the protective sheet 10 may, for example, have only elements or only electrodes. In other words, it is sufficient that at least one type of circuit component is placed on the circuit surface protected by the protective sheet 10. And at least one type of circuit component will be covered and protected by the protective sheet 10.

[0028] The above wetting process is performed as needed. The above wetting process is particularly effective when a protective sheet 10 (described in detail later) containing a water-soluble polymer compound is used. The above wetting process can be performed, for example, by bringing a gas containing water vapor into contact with the circuit surface Sa, or by spraying mist-like water onto the circuit surface Sa, as shown in Figure 1B. Alternatively, it can be performed by applying water to the circuit surface Sa. By performing the wetting process, the adhesion of the protective sheet 10 containing the water-soluble polymer compound to the circuit surface Sa can be improved.

[0029] In the above protection step, the protective sheet 10 is placed on the surface (circuit surface) of the substrate on which one of the circuit components is located (see Figure 1C). In other words, the protective sheet 10 may be placed on the circuit surface on which wiring is located as a circuit component, on one side of the substrate on which a sensor is located as a circuit component, or on one side of the substrate on which an electrode is located as a circuit component. In the above protection step, the protective sheet 10 is placed on at least one side of the substrate so as to cover the circuit components with the protective sheet 10.

[0030] As shown in Figures 1D and 2A, the protective sheet 10 is formed in a sheet shape and has flexibility that allows it to be deformed with relatively weak force. Furthermore, the protective sheet 10 has adhesive properties that allow it to adhere to the substrate S. A release liner 15 may be superimposed on one or both sides of the protective sheet 10 at a stage before or during the manufacturing process. Please note that each figure in the drawings is a schematic representation and does not necessarily reflect the actual aspect ratio of the object. The same applies to the other drawings.

[0031] In the expansion process described above, a substrate S is prepared, for example as shown in Figure 1E, which has a weak portion formed inside for cleavage. Next, for example as shown in Figure 1F, with a protective sheet 10 placed on one side of the substrate S, the laminate of the substrate S and the protective sheet 10 is divided into smaller pieces. When dividing into smaller pieces, a dicing tape 20 placed on the other side of the substrate S is used, and the dicing tape 20 is stretched in the planar direction to increase the surface area of ​​the dicing tape 20. This divides the laminate of the substrate S and the protective sheet 10 into smaller pieces and further widens the spacing between adjacent substrates S along the planar direction.

[0032] As shown in Figure 2B, the dicing tape 20 comprises a base layer 21 and an adhesive layer 22 superimposed on the base layer 21. A commercially available product can be used as the dicing tape 20.

[0033] In the removal process described above, as schematically shown in Figure 1G, each small piece 10' of the protective sheet that is overlapping the substrate piece S' is removed by dissolving at least a portion of the multiple small pieces 10' of the protective sheet, or by peeling each small piece 10' from the substrate piece S'.

[0034] In the above bonding process, for example, a small piece S' of the substrate is bonded to the adherend Z either directly or via a predetermined member. In the bonding process, for example, multiple small pieces S' of the substrate may be stacked. Alternatively, for example, a small piece S' of the substrate with a coating resin attached may be bonded to the adherend Z. Examples of the substrate Z include an interposer, a wiring circuit board, or a small piece of a substrate (when small pieces of substrate are stacked and laminated).

[0035] The electronic component device manufactured by the manufacturing method of this embodiment may be, for example, a semiconductor device equipped with multiple semiconductor chips, a device equipped with a system LSI having complementary MOS (CMOS Complementary Metal Oxide Semiconductor), or a device (MEMS Micro Electro Mechanical System) in which mechanical components, sensors, actuators, and electronic circuits are integrated on a single silicon substrate, glass substrate, organic material substrate, etc., by microfabrication technology. The manufactured electronic component device may also be a device equipped with a wiring board.

[0036] The following explanation will use the manufacturing method of semiconductor devices as an example of a method for manufacturing electronic components and devices.

[0037] In general, semiconductor device manufacturing methods involve cutting out semiconductor chips from a semiconductor wafer (substrate) on which circuit components are arranged on at least one side, and then assembling a semiconductor device equipped with the cut-out semiconductor chips. In the semiconductor device manufacturing method of this embodiment, the above-mentioned protective sheet 10 and dicing tape 20 are used as at least auxiliary tools, and the semiconductor device is manufactured as follows.

[0038] As specific embodiments of the method for manufacturing a semiconductor device, the first to fifth embodiments will be described in detail.

[0039] "First Embodiment" The first embodiment of the method for manufacturing a semiconductor device includes an assembly step of cutting out a semiconductor chip X from a semiconductor wafer W in which at least one side is a circuit surface, and assembling a semiconductor device having the semiconductor chip X. Such an assembly process includes the step of placing a protective sheet 10 to protect the circuit components on at least one side of the semiconductor wafer W, which is the circuit side on which the circuit components are arranged, A process to create multiple small pieces of a laminate in which the semiconductor chips X, which are the small pieces of semiconductor wafer W, and the small pieces of protective sheet 10, are stacked on top of each other by dividing the stacked semiconductor wafer W and protective sheet 10 so that there are gaps in the planar direction, A process to remove each small piece 10' of the protective sheet that overlaps the circuit surface of the semiconductor chip X, The process includes the step of arranging the semiconductor chip X with its circuit surface facing the substrate, thereby joining the semiconductor chip X to the substrate.

[0040] The assembly process of the first embodiment includes, for example, the following steps: Specifically, the assembly process of the first embodiment is as follows: A mounting process involves attaching a semiconductor wafer W, on which circuit components are arranged on both sides, to a dicing tape 20, thereby fixing the semiconductor wafer W to the dicing tape 20. A protection step (the overlapping step described above) is performed by attaching a protective sheet 10 to one circuit surface of the semiconductor wafer W to protect the circuit surface, A stealth processing step is performed to prepare the semiconductor wafer W for fragmentation into semiconductor chips (dies) by forming a vulnerable area inside the semiconductor wafer W to which a protective sheet 10 has been attached using laser light, An expansion process (a process for producing small pieces of the above-mentioned laminate) is performed by stretching the dicing tape 20 to break down both the semiconductor wafer W and the protective sheet 10 into small pieces, A removal process (the removal process described above) to remove multiple small pieces 10' of the protective sheet attached to the semiconductor chip X, A pickup process to remove the semiconductor chip X by separating it from the adhesive layer 22, The process includes a bonding step (the bonding step described above) in which the extracted semiconductor chip X is bonded to a substrate. When these steps are carried out, the protective sheet 10 and dicing tape 20 described above are used as manufacturing aids.

[0041] The semiconductor wafer W before being cut into smaller pieces for semiconductor chips X may, for example, be ground to a desired thickness by backgrinding. Specifically, in backgrinding, a semiconductor wafer W with a backgrind tape B attached to the circuit surface may be ground to reduce the thickness of the semiconductor wafer W until it reaches the thickness of the semiconductor chip X to be manufactured later.

[0042] The semiconductor wafer W is configured to produce multiple semiconductor chips X. Specifically, the semiconductor wafer W is divided into smaller pieces with spacing in multiple directions along the surface (for example, directions along the surface that are mutually orthogonal), thereby enabling the fabrication of multiple semiconductor chips X. Furthermore, in the semiconductor wafer W, circuit components are arranged on at least one side, so that at least one side is a circuit surface. For example, in the semiconductor wafer W used in the first embodiment, both sides are circuit surfaces. On the other hand, in the semiconductor wafer W used in the other embodiments, one of the sides is a circuit surface. As shown in Figure 2C, in the first embodiment, electrode portions D as circuit components are arranged on both sides of the semiconductor wafer W. One electrode portion D is electrically connected to the other electrode portion D.

[0043] More specifically, a semiconductor chip X, fabricated by dividing a semiconductor wafer W, has electrode portions D arranged on both surfaces and which are electrically connected to each other. More specifically, as shown in Figure 2D, electrode portions D are arranged on both sides of the semiconductor chip X, and conductive through-vias V extending through the thickness direction are arranged inside the semiconductor chip X. The electrode portions D on both sides are electrically connected to each other via these through-vias V. Both the electrode portions D and the through-vias V are made of a conductive material such as a metal material. The through-vias V are also called TSVs. The electrode portions D and the through-vias V may be made of an integrated component, or they may be made of separately formed components joined together. Furthermore, in the semiconductor industry in recent years, with the further advancement of integration technology, there is a demand for thinner semiconductor chips (for example, with a thickness of 20 μm to 50 μm). The shape of a semiconductor chip when viewed from one side in the thickness direction is, for example, rectangular, and the length of one side is a predetermined length, for example, 5 mm to 20 mm.

[0044] In the following drawings, the diagrams showing the manufacturing method of the first embodiment are labeled "I". Similarly, the second to fifth embodiments are labeled "II" to "V", respectively.

[0045] In the mounting process, the semiconductor wafer W is fixed to the dicing tape 20. As shown in Figure 3A, a glass carrier G is attached to one circuit side of the semiconductor wafer W. The glass carrier G is placed on one circuit side of the semiconductor wafer W to support the relatively thin semiconductor wafer and to facilitate the handling of such a semiconductor wafer. For example, the glass carrier G is attached to the circuit side after a circuit has been formed on one side of the wafer, and is used to further form a circuit on the other side while attached to the wafer. The thickness of the glass carrier G is, for example, 0.5 mm to 5.0 mm.

[0046] In the mounting process, the dicing ring R is attached to the adhesive layer 22 of the dicing tape 20, and the semiconductor wafer W is attached to the exposed surface of the adhesive layer 22 (see Figure 3B). Next, the glass carrier G is peeled off from the semiconductor wafer W (see Figure 3C).

[0047] Before the subsequent protection process, a wetting process may be performed to increase the humidity of the gas in contact with the circuit surface Wa of the semiconductor wafer W, as shown in Figure 3D. If the protective sheet 10 contains a water-soluble polymer compound, performing the wetting process will improve the adhesion between the circuit surface Wa of the semiconductor wafer W and the protective sheet 10. Note that the wetting process is not mandatory and can be performed as needed.

[0048] In the protection process, a protective sheet 10 is placed on one of the circuit surfaces of the semiconductor wafer W (see Figure 3E). In the protection step, for example, the protective sheet 10 may be superimposed on the circuit surface by directly pressing and attaching it to the circuit surface. Alternatively, a protective sheet composition may be prepared containing a solid component constituting the protective sheet 10 and a solvent that dissolves the solid component, and such a composition may be applied to the circuit surface, followed by volatilization of the solvent to form a protective sheet 10 that comes into contact with the circuit surface, thereby superimposing the protective sheet 10 on the circuit surface. By placing a protective sheet 10 over the circuit surface of the semiconductor wafer W, it is possible to prevent dust and other debris from adhering to the circuit surface of the semiconductor wafer W covered by the protective sheet 10 until the protective sheet 10 is peeled off.

[0049] In the stealth processing step, a vulnerable area is formed inside the semiconductor wafer W to allow it to be divided into smaller semiconductor chips X. This vulnerable area is formed inside the semiconductor wafer W by irradiating it with laser light L (see Figure 3F). The laser light L is irradiated onto the semiconductor wafer W from, for example, the dicing tape side. The laser light L is irradiated onto the semiconductor wafer W in such a way that each semiconductor chip X, which is produced by dividing the semiconductor wafer W in a subsequent expansion step, has the electrode portion D as designed in advance. The stealth processing step can be carried out, for example, using a commercially available stealth dicing apparatus.

[0050] In the expanding process, as shown in Figure 3G, the dicing tape 20 and protective sheet 10 are placed on both sides of the semiconductor wafer W, respectively, and the dicing tape 20 is stretched in the planar direction to increase its surface area. This divides the laminate of the semiconductor wafer W and protective sheet 10 into smaller pieces, and widens the spacing between adjacent semiconductor chips X formed by these pieces along the planar direction. Specifically, a dicing ring R is attached to the adhesive layer 22 of the dicing tape 20 and then fixed to the holder H of the expanding device. The dicing tape 20 is stretched in the planar direction by pushing up the dicing tape 20 from below using the push-up member U provided by the expanding device. This causes the semiconductor wafer W and protective sheet 10 to be divided into smaller pieces under specific temperature conditions. The above temperature conditions are, for example, -20°C to 0°C. The expanded state is released by lowering the push-up member U (this completes the low-temperature expanding process). When performing the expansion process at low temperatures, the protective sheet 10 needs to be cut and broken into smaller pieces. The protective sheet 10 described above is designed to cut cleanly at this time. Furthermore, in the expanding process, the dicing tape 20 is stretched under higher temperature conditions (for example, between 10°C and 25°C) to increase its surface area. This pulls adjacent semiconductor chips X apart in the planar direction of the film surface, further widening the kerf (spacing) (room temperature expanding process). In the expanding process, the dicing tape 20 is stretched in the planar direction to increase its surface area, thereby dividing the protective sheet 10 together with the semiconductor wafer W into smaller pieces. More specifically, by stretching the dicing tape 20, the semiconductor wafer W can be divided into smaller semiconductor chips X using the aforementioned vulnerable areas within the semiconductor wafer as boundaries. At this time, along with the division of the semiconductor wafer W into semiconductor chips X, the protective sheet 10 is also divided into smaller pieces.

[0051] In the removal process, as shown in Figure 3H, a liquid containing water is brought into contact with multiple small pieces 10' of the protective sheet, and at least a portion of each small piece 10' is dissolved in the liquid, thereby removing each small piece 10' of the protective sheet that is overlapping the semiconductor chip X. By removing the small pieces 10' of the protective sheet in this way, all of the multiple small pieces 10' of the protective sheet can be removed relatively easily, and the number of foreign objects adhering to the semiconductor chip surface can be reduced relatively easily by the above-mentioned liquid. In addition, the surfaces of each semiconductor chip X where the small pieces 10' of the protective sheet overlapped can also be cleaned with the liquid.

[0052] The fragments of the protective sheet (multiple small pieces 10' of the protective sheet) may be removed by dissolving all of them in the liquid. Alternatively, some of the components of the fragments 10' of the protective sheet may be dissolved in the liquid, and the multiple small pieces 10' of the protective sheet, whose adhesion to the semiconductor chip X has weakened, may be peeled off from the semiconductor chip X to remove them.

[0053] The liquid containing water is not particularly limited as long as it is a liquid substance containing water. Such a liquid may contain 30% by mass or more of water, 50% by mass or more, 70% by mass or more, 80% by mass or more, or 90% by mass or more. The above liquid may contain components that dissolve in water in addition to water. Examples of such components include water-soluble organic solvents. Examples of such water-soluble organic solvents include monohydric alcohols with 4 or fewer carbon atoms, such as methanol, ethanol, propanols such as isopropyl alcohol, or butanols such as t-butanol.

[0054] In the removal step of the first embodiment, the small pieces 10' of the protective sheet may be immersed in the stirred liquid to bring the liquid into contact with the small pieces 10' of the protective sheet. Alternatively, the liquid sprayed from a nozzle or the like may be brought into contact with the small pieces 10' of the protective sheet. The temperature of the liquid is not particularly limited and may be set to, for example, 10°C or more and 90°C or less. The temperature of the liquid is preferably 40°C or higher in that it allows for the removal of multiple small pieces 10' of the protective sheet in a shorter time.

[0055] For example, in the removal process, a disc-shaped stage supporting the dicing tape 20 from below is rotated circumferentially, and the liquid is sprayed toward multiple semiconductor chips X that are attached to the adhesive layer 22 of the dicing tape 20. This makes it possible to remove multiple small pieces 10' of the protective sheet that are overlapping the semiconductor wafer W. The rotation speed of the stage may be, for example, 500 rpm to 4000 rpm, the amount of liquid sprayed may be, for example, 0.05 L / min to 5.0 L / min, and the spraying time may be, for example, 5 seconds to 300 seconds.

[0056] According to the semiconductor device manufacturing method described above, a protective sheet 10 is placed on the side of the semiconductor wafer W on which the circuit components are arranged (circuit surface), thus preventing foreign matter from adhering to the circuit surface until the protective sheet 10 is removed. Specifically, since the semiconductor wafer W is cut into small pieces to produce a semiconductor chip X while the semiconductor wafer W and the protective sheet 10 are overlapping, it is possible to prevent foreign matter such as fragments that may be generated due to the cutting of the semiconductor wafer W from adhering to the circuit surface of the semiconductor chip X. Even if foreign matter is adhering to the circuit surface of the semiconductor chip X before the protective sheet 10 is placed on top, that foreign matter can be removed when the small piece 10' of the protective sheet overlapping the circuit surface of the semiconductor chip X is removed. Therefore, it is possible to suppress the adhesion of foreign matter to the circuit surface of the manufactured semiconductor chip X.

[0057] The components and physical properties of the protective sheet 10 will be explained in detail later.

[0058] In the pickup process, as shown in Figure 3I, the semiconductor chip X is peeled from the adhesive layer 22 of the dicing tape 20. Specifically, the pin member P is raised to push up the semiconductor chip X to be picked up via the dicing tape 20. The pushed-up semiconductor chip X is held by the suction jig J.

[0059] When performing the pickup process as described above, it is necessary that the semiconductor chip X be easily peeled off from the adhesive layer 22 of the dicing tape 20. Furthermore, when performing the expansion process described above, it is necessary to efficiently break down the semiconductor wafer W and protective sheet 10 into small pieces by stretching the dicing tape 20. The dicing tape 20 described above is designed to effectively perform these functions. For example, the dicing tape 20 is configured such that when irradiated with active energy rays (e.g., ultraviolet light), the adhesive layer 22 hardens, reducing the adhesive strength of the adhesive layer 22. Because the adhesive strength of the adhesive layer 22 can be reduced by hardening it after irradiation, the semiconductor chip X can be peeled off the adhesive layer 22 relatively easily after irradiation. Dicing tapes 20 with such a configuration are commercially available.

[0060] As described above, electrode portions D that are electrically conductive are arranged on both sides of the semiconductor chip X that has been extracted by the pickup process. On the surface layers of one and the other sides of the semiconductor chip X, electrode portions D and non-electrode portions other than electrode portions D are formed. The non-electrode portions are made of, for example, an insulating material (silicon oxide). As shown in Figure 2D, on one and the other sides of the semiconductor chip X, the surfaces of the electrode portions D and the non-electrode portions are flush. The electrode portions D are formed to have a thickness of 5 nm to 10 μm from the outermost surface of the semiconductor chip X. The through-vias V described above, which are arranged to penetrate the semiconductor chip X in the thickness direction, are covered with the insulating material in parts other than the parts that are in contact with the electrode portions D. In other words, a part of the surface of the through-vias V that extend in the thickness direction of the semiconductor chip X is covered with the insulating material, and another part is in contact with the electrode portions D.

[0061] The bonding process is performed after the removal process and the pickup process. In the bonding process, as shown in Figure 3J, for example, the semiconductor chip X is bonded to the substrate with the side (circuit side) from which the protective sheet fragment 10' of the semiconductor chip X has been removed facing the substrate. This method of bonding the substrate and the semiconductor chip X with the circuit side of the semiconductor chip X facing the substrate is generally called flip bonding. Even with this bonding method, the removal process described above can reduce the number of foreign objects adhering to the circuit side of the semiconductor chip X, thereby suppressing adverse effects caused by foreign objects that have entered between the circuit side of the semiconductor chip X and the substrate.

[0062] In the bonding process, for example, a semiconductor chip X is bonded to an adherend Z (such as a wiring board). At this time, the adherend Z and the semiconductor chip X are bonded in such a way that the electrode portion D on the adherend Z side and the electrode portion D on the semiconductor chip X side are electrically conductive. Furthermore, in the bonding process, for example, at least two semiconductor chips X are stacked, and the electrode portion D on one semiconductor chip X and the electrode portion D on the other semiconductor chip X are directly connected to each other. In other words, the electrode portions D on one semiconductor chip X and the electrode portion D on the other semiconductor chip X are directly connected to each other so that they are electrically conductive, and the semiconductor chips X are stacked. As described above, since the electrode portions and non-electrode portions are arranged to be flush with each other on the circuit surface of the semiconductor chip, it is preferable to have as little foreign matter as possible adhering to the circuit surface of the semiconductor chip X when the electrode portions are directly connected to each other. In particular, it is preferable that no foreign matter is adhering to the surface of the electrode portions. The manufacturing method of this embodiment can suppress the adhesion of foreign matter to the surface of the semiconductor chip X, and is therefore particularly effective when bonding multiple semiconductor chips X to each other as described above. When stacking multiple semiconductor chips X as described above during the bonding process, the number of foreign objects that can get between one semiconductor chip X and the other is reduced because the stacking of multiple semiconductor chips X is such that the adhesion of foreign objects to the circuit surface is suppressed. Therefore, the electrode portions D between adjacent semiconductor chips X can be connected to each other more reliably. Thus, the circuits of multiple semiconductor chips X are electrically connected to each other with high reliability.

[0063] When directly connecting the electrode sections D to each other, for example, an atomic diffusion bonding method can be employed. Atomic diffusion bonding can be carried out, for example, using a commercially available atomic diffusion bonding apparatus.

[0064] In the first embodiment, a resin encapsulation step may be performed to encapsulate (cover) the semiconductor chip X with a thermosetting resin or the like in order to protect the semiconductor chip X after the bonding process.

[0065] <Details of the protective sheet in the first embodiment> The thickness of the protective sheet 10 is not particularly limited, but is, for example, 1 μm or more and 100 μm or less. Such a thickness may be 3 μm or more, or 5 μm or more. Such a thickness may also be 40 μm or less. If the protective sheet 10 is a laminate, the above thickness is the total thickness of the laminate.

[0066] The protective sheet 10 described above is configured to be broken down into smaller pieces by being stretched in the planar direction during the expansion process described above so as to increase its surface area. Each piece of the protective sheet 10 will have the same surface area as the circuit surface of the semiconductor chip X.

[0067] In the removal process described above, the protective sheet 10 contains at least a water-soluble polymer compound so that small pieces 10' of the protective sheet overlapping the semiconductor chip X are removed by a liquid containing water.

[0068] Examples of water-soluble polymer compounds include polyvinyl alcohol (PVA) and polyvinylpyrrolidone (PVP). One of these may be used as the water-soluble polymer compound, or two or more may be used in combination.

[0069] The degree of saponification (mol%) of the polyvinyl alcohol described above is preferably 50 or higher, and more preferably 60 or higher. Furthermore, the degree of saponification is preferably 98 or lower. A saponification degree of 50 or higher for polyvinyl alcohol makes it easier to dissolve in water-containing liquids during the removal process.

[0070] The degree of saponification described above is determined by proton magnetic resonance spectroscopy performed under the following analytical conditions: 1 It is measured by H MNR. If the protective sheet 10 contains components other than PVA, the measurement will be performed after separating and extracting the PVA by methanol extraction or the like to avoid peak overlap in the measurement chart. Analytical instrument: FT-NMR: Bruker Biospin, "AVANCE III-400" Observation frequency: 400MHz (1H) Measurement solvent: Deuterium water or deuterium DMSO Measurement temperature: 80℃ Chemical shift standard: External standard TSP-d4 (0.00ppm) (when measuring heavy water) : Measurement solvent (2.50 ppm) (when measuring heavy DMSO) The degree of saponification is calculated using the following formula based on the methylene group-derived peaks of the vinyl alcohol unit (VOH) (heavy water; 2.0-1.1 ppm, heavy DMSO; 1.9-1.0 ppm) and the acetyl group-derived peaks of the vinyl acetate unit (VAc) (heavy water; around 2.1 ppm, heavy DMSO; around 2.0 ppm). In the following formula, VOH(-CH2-) represents the intensity of the methylene group-derived peak of the vinyl alcohol unit (VOH), and VAc(CH3CO-) represents the intensity of the acetyl group-derived peak of the vinyl acetate unit (VAc).

number

[0071] The average degree of polymerization of the above polyvinyl alcohol is preferably 100 or more, and more preferably 200 or more. Furthermore, the average degree of polymerization is preferably 1000 or less, and more preferably 800 or less. Having an average degree of polymerization of 200 or more for polyvinyl alcohol makes it easier to form the protective sheet 10 described above. On the other hand, having an average degree of polymerization of 1000 or less for polyvinyl alcohol makes it easier to dissolve in a water-containing liquid during the removal process.

[0072] The average degree of polymerization mentioned above is measured by gel permeation chromatography (GPC). The measurement conditions are as follows: Analysis equipment: Agilent Technologies "1260 Infinity" Columns: Tosoh Corporation, TSKgel G6000PWXL + TSKgel G3000PWXL (connected in series) Column temperature: 40℃ Eluent: 0.2M sodium nitrate aqueous solution Flow rate: 0.8mL / min Injection volume: 100μL Detector: Differential refractometer (RI) Standard samples: polyethylene glycol (PEG), polyvinyl alcohol (PVA) The weight-average molecular weight (Mw) of the sample under test (PVA) and the PVA standard sample with a known average degree of polymerization are calculated using GPC measurement with PEG standard samples. A calibration curve is created from the average degree of polymerization of the PVA standard sample and the calculated weight-average molecular weight (Mw) of the PVA standard sample. Using this calibration curve, the average degree of polymerization of the sample under test (PVA) is determined from its weight-average molecular weight (Mw).

[0073] The elongation at break of the protective sheet 10 used in the manufacturing method of the first embodiment, etc., is preferably 30.0% or less at -15°C. Such elongation at break may be 20.0% or less, or 10.0% or less. The above elongation at break may be 0.1% or more. The fact that the above-mentioned elongation at break is between 0.1% and 30.0% allows the protective sheet 10 to be more reliably broken into smaller pieces during the expansion process.

[0074] The above-mentioned elongation at break can be increased, for example, by increasing the molecular weight of the water-soluble polymer compound contained in the protective sheet 10. On the other hand, the above-mentioned elongation at break can be decreased, for example, by decreasing the molecular weight of the water-soluble polymer compound contained in the protective sheet 10.

[0075] The above-mentioned elongation at break is measured under the following measurement conditions. • Measuring equipment: Tensile testing machine (Shimadzu Corporation's "Autograph AG-IS" can be used) • Measurement sample: 30 μm thick • Test specimen: Strip-shaped, 10mm wide and 50mm long, with an initial chuck distance of 20mm. • Tensile speed: 10 mm / sec • Measurement temperature: -15°C (Measurement begins after holding at -15°C for 5 minutes) The elongation rate at break (the ratio of the length elongated to the original length) is defined as the elongation at break.

[0076] The breaking strength of the protective sheet 10 described above may be 500 MPa or less at -15°C, or 200 MPa or less. Furthermore, the breaking strength may be 1.0 MPa or more. Such breaking strength is the tensile force at the time of fracture in the measurement of the elongation at fracture described above. The fact that the above-mentioned breaking strength is between 1.0 MPa and 500 MPa allows the protective sheet 10 to be more reliably broken into smaller pieces during the expansion process.

[0077] The above-mentioned breaking strength can be increased, for example, by increasing the molecular weight of the water-soluble polymer compound contained in the protective sheet 10. On the other hand, the above-mentioned breaking strength can be decreased, for example, by decreasing the molecular weight of the water-soluble polymer compound contained in the protective sheet 10.

[0078] The adhesion of the protective sheet 10 to the semiconductor wafer W is indicated by the peeling force when peeling the protective sheet 10 from the silicon bare wafer. The peeling force of the protective sheet 10 at 25°C may be 10.0 [N / 10mm] or less, or 8.0 N / 10mm] or less. The peeling force may also be 0.01 [N / 10mm] or more. By having a peeling force of 0.01 [N / 10mm] or more and 10.0 [N / 10mm] or less, it is possible to further suppress the unintentional peeling of the fragmented protective sheet 10 from the semiconductor chip X when the protective sheet 10 is fragmented during the expansion process.

[0079] The peeling force described above can be increased, for example, by increasing the molecular weight of the water-soluble polymer compound contained in the protective sheet 10. On the other hand, the peeling force described above can be decreased, for example, by decreasing the molecular weight of the water-soluble polymer compound contained in the protective sheet 10.

[0080] The peeling force described above is measured under the following measurement conditions. To measure the peel force of one side of the protective sheet 10 (the side attached to the semiconductor wafer W), a sample for measurement is prepared as follows. First, at 25°C, backing tape is applied to the side of the protective sheet 10 opposite to the aforementioned side using a hand roller. Next, the sample for measurement is processed to a width of 100 mm, and a silicon bare wafer is bonded to the aforementioned side of the protective sheet 10. Bonding is performed at 90°C and a speed of 10 mm / second. Then, in an atmosphere of 23°C, the protective sheet 10 is peeled from the bare wafer together with the backing tape at a peeling angle of 180° and a peeling speed of 300 mm / min, and the peel force is measured. Finally, the measured value is converted to be expressed in units of [N / 10 mm]. For example, an "Autograph (manufactured by SHIMADZU)" can be used as the measuring device.

[0081] The tensile modulus (tensile storage modulus E') of the protective sheet 10 at -15°C is preferably 0.01 GPa or more and 10.0 GPa or less. Such a tensile modulus may be 0.05 GPa or more, or 0.10 GPa or more. Furthermore, such a tensile modulus may be 5.0 GPa or less, or 3.0 GPa or less. The fact that the tensile modulus at -15℃ is between 0.01 GPa and 10.0 GPa allows the protective sheet 10 to be more reliably broken down into smaller pieces during the expansion process.

[0082] The elastic modulus (tensile modulus) of the protective sheet 10 can be increased, for example, by increasing the molecular weight of the water-soluble polymer compound contained in the protective sheet 10. On the other hand, the tensile modulus can be decreased, for example, by decreasing the molecular weight of the water-soluble polymer compound contained in the protective sheet 10.

[0083] The tensile modulus mentioned above is measured under the following conditions. • Measurement equipment: Solid viscoelasticity measuring device (e.g., "RSAIII" manufactured by TA Instruments Inc. can be used) • Measurement sample: 50 μm thick • Test specimen: Strip-shaped, 10mm wide and 40mm long, with an initial chuck distance of 20mm. • Measurement mode: Tensile mode • Frequency 1Hz, heating rate 10℃ / min, distortion 0.1% • Measurement temperature range: -40°C to 80°C (Hold at -40°C for 5 minutes before starting to raise temperature) Read the tensile modulus (tensile storage modulus) [MPa] at -15℃ and 25℃.

[0084] The surface free energy of the protective sheet 10 is 70 [mJ / m²] at 25°C. 2 It may be less than or equal to 65[mJ / m 2 It may be less than or equal to 30 [mJ / m]. Note that the above surface free energy is 30 [mJ / m]. 2 This is also acceptable. Because the surface free energy is within the above range, the wettability of the protective sheet 10 to water is moderately good, allowing the protective sheet 10 to be removed more easily during the removal process.

[0085] The above surface free energy can be increased, for example, by increasing the proportion of hydrophilic groups (such as -OH groups) in the molecule of a water-soluble polymer. On the other hand, the above surface free energy can be decreased, for example, by increasing the proportion of hydrophobic groups (such as alkyl groups) in the molecule of a water-soluble polymer.

[0086] The above surface free energy is calculated from the results of contact angle measurement. Specifically, under the conditions of 20°C and a relative humidity of 65%, the contact angles of droplets of water (H2O) and methylene iodide (CH2I2) that contact the surface of the above protective sheet 10 are measured using a contact angle meter. Next, the surface free energy is calculated as follows from the measured values of the contact angle θw of water and the contact angle θi of methylene iodide. Specifically, according to the method of Owens et al. described in Journal of Applied Polymer Science, vol.13, p1741-1747 (1969), γs d (dispersion component of surface free energy) and γs h (polar component of surface free energy) are obtained. And the value γs (= γs d + γs h ) obtained by adding γs d and γs h is taken as the surface free energy of the above protective sheet 10. γs d (dispersion component) and γs h (polar component) are respectively obtained as the solutions of the simultaneous equations of the following equations (1) and (2). In equations (1) and (2), γw is the surface free energy of water, γw d is the dispersion component of the surface free energy of water, γw h is the polar component of the surface free energy of water, γi is the surface free energy of methyl iodide, γi d is the dispersion component of the surface free energy of methyl iodide, γi h is the polar component of the surface free energy of methyl iodide, and they are known values as follows. γw = 72.8 [mJ / m 2 γw d = 21.8 [mJ / m 2 γw h = 51.0 [mJ / m 2 γi = 50.8 [mJ / m 2 γi d = 48.5 [mJ / m​​​​2 ] γi h =2.3 [mJ / m 2 ]

number

[0087] Specifically, the surface free energy of one side of the protective sheet 10 (the side attached to the semiconductor wafer W) is measured. The contact angles of water and methylene iodide are measured, and the average of five measurements is adopted. Note that 1 mL of liquid is dropped onto the surface and the contact angle is measured within 5 seconds. The dispersion component and polar component are calculated from each contact angle measurement, and the surface free energy is determined by their sum.

[0088] Next, the second to fifth embodiments will be described in detail. Note that the same explanations as those for the first embodiment will not be repeated for the second to fifth embodiments. Unless otherwise specified, the same operations as in the first embodiment may be performed in the second to fifth embodiments.

[0089] "Second Embodiment" The method for manufacturing a semiconductor device according to the second embodiment includes the same steps as described above as the method for manufacturing a semiconductor device according to the first embodiment. However, the method for manufacturing a semiconductor device of the second embodiment differs from the method for manufacturing a semiconductor device of the first embodiment in that the circuit components are arranged on one side of the semiconductor wafer W, the structure and components of the protective sheet 10, and the method for removing the protective sheet 10 in the removal process.

[0090] More specifically, in the semiconductor device manufacturing method of the second embodiment, the protective sheet 10 contains a curable composition, and the protective sheet 10 superimposed on the circuit surface of the semiconductor wafer W is cured by a curing process, and then the laminate of the semiconductor wafer W and the protective sheet 10 is broken into smaller pieces.

[0091] The protective sheet 10 used in the second embodiment includes a curable composition that hardens by a curing treatment. For example, the protective sheet 10 is formed from a curable composition. The curable composition contains a curable compound that initiates a curing reaction upon curing treatment. The curable compound initiates a curing reaction upon curing treatment such as irradiation with active energy rays, such as ultraviolet light, or heating treatment. In the second embodiment, the protective sheet 10 hardens during the curing process, making it easier to divide and fragment the protective sheet 10 during the expansion process. Furthermore, the hardening of the protective sheet 10 during the curing process reduces its adhesive strength. Therefore, each small piece 10' of the protective sheet can be relatively easily peeled off from each semiconductor chip X after the curing process.

[0092] In the second embodiment, as shown in Figure 4A, the semiconductor wafer W and protective sheet 10 are stacked on the dicing tape 20 in the same order as in the first embodiment. Preferably, a release liner 15 is attached to the protective sheet 10. Then, as shown in Figure 4B, a stealth processing step is performed on the semiconductor wafer W in the same manner as in the first embodiment.

[0093] For example, the protective sheet 10 used in the second embodiment is hardened by irradiation with ultraviolet light M or the like, as shown in Figure 4C. Specifically, with the adhesive layer 22 attached to one side of the semiconductor wafer W and the protective sheet 10 attached to the other side of the semiconductor wafer W, ultraviolet light or the like is irradiated onto at least the protective sheet 10. The protective sheet 10 hardens due to the irradiation with ultraviolet light or the like. After that, as shown in Figure 4D, the release liner 15 is peeled off from the protective sheet 10. Furthermore, as shown in Figure 4E, the semiconductor wafer W and the protective sheet 10 are divided into smaller pieces in the same manner as in the first embodiment.

[0094] (Removal process in the second embodiment) In the removal step of the second embodiment, a peeling adhesive tape T is used to peel off the small piece 10' of the protective sheet from the semiconductor chip X. As the peeling adhesive tape T, for example, a commercially available adhesive tape can be used.

[0095] In the removal step of the second embodiment, as shown in Figure 4F, the multiple small pieces 10' of the protective sheet are removed together with the adhesive tape T by peeling off the adhesive tape T attached to the multiple small pieces 10' of the protective sheet. By using the adhesive tape T for peeling in this way, multiple small pieces 10' of the protective sheet can be removed relatively easily. In addition, when peeling off the multiple small pieces 10' of the protective sheet, foreign matter adhering to the circuit surface of the semiconductor can also be removed.

[0096] The adhesion of the protective sheet 10 used in the second embodiment to the semiconductor wafer W is indicated, for example, by the peeling force when peeling the protective sheet 10 from the silicon bare wafer. The method for measuring such peeling force is as described above. Note that the peeling force between the protective sheet 10 and the semiconductor chip X is smaller than the peeling force between the protective sheet 10 and the peeling adhesive tape T after the curing treatment described above.

[0097] <Details of the protective sheet in the second embodiment> The protective sheet 10 used in the second embodiment includes, for example, an acrylic polymer, an isocyanate compound, and a polymerization initiator.

[0098] The above-described acrylic polymer contains at least alkyl (meth)acrylate structural units, hydroxyl group-containing (meth)acrylate structural units, and polymerizable group-containing (meth)acrylate structural units in its molecule. These structural units constitute the main chain of the acrylic polymer. Each side chain in the above-described acrylic polymer is included in each structural unit that constitutes the main chain.

[0099] The constituent units of the alkyl (meth)acrylates described above are derived from alkyl (meth)acrylate monomers. In other words, the molecular structure after the polymerization reaction of alkyl (meth)acrylate monomers is the constituent unit of alkyl (meth)acrylate. The notation "alkyl" indicates the number of carbon atoms in the hydrocarbon portion esterified to (meth)acrylic acid. The hydrocarbon portion of the alkyl (meth)acrylate constituent unit may be a saturated hydrocarbon or an unsaturated hydrocarbon. The number of carbon atoms in the alkyl portion may be between 6 and 10.

[0100] Acrylic polymers have hydroxyl group-containing (meth)acrylate constituent units, and the hydroxyl groups in such constituent units readily react with isocyanate groups. By having an acrylic polymer containing hydroxyl group-containing (meth)acrylate structural units and an isocyanate compound coexist in the protective sheet 10, the protective sheet 10 can be moderately cured. As a result, the acrylic polymer can gel sufficiently. Therefore, the protective sheet 10 can maintain its shape while exhibiting adhesive properties.

[0101] The constituent units of hydroxyl group-containing (meth)acrylate are preferably the constituent units of hydroxyl group-containing C2-C14 alkyl (meth)acrylate. The notation "C2-C14 alkyl" represents the number of carbon atoms (2 to 14) of the hydrocarbon portion ester-bonded to (meth)acrylic acid. In other words, a hydroxyl group-containing C2-C14 alkyl (meth)acrylate monomer refers to a monomer in which (meth)acrylic acid and an alcohol (usually a dihydric alcohol) with 2 to 14 carbon atoms are ester-bonded. The C2-C14 alkyl hydrocarbon portion is usually a saturated hydrocarbon. For example, the C2-C14 alkyl hydrocarbon portion is a linear saturated hydrocarbon or a branched saturated hydrocarbon. It is preferable that the C2-C14 alkyl hydrocarbon portion does not contain polar groups such as oxygen (O) or nitrogen (N).

[0102] Examples of constituent units of hydroxyl group-containing C2-C14 alkyl (meth)acrylate include hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxy-n-butyl (meth)acrylate, and hydroxy-iso-butyl (meth)acrylate, which are all constituent units of hydroxybutyl (meth)acrylate. In the constituent units of hydroxybutyl (meth)acrylate, the hydroxyl group (-OH group) may be bonded to the terminal carbon (C) of the hydrocarbon portion, or to a carbon (C) other than the terminal carbon of the hydrocarbon portion.

[0103] The above acrylic polymer contains polymerizable group-containing (meth)acrylate units that have polymerizable unsaturated double bonds in their side chains. Because the above-mentioned acrylic polymer contains polymerizable group-containing (meth)acrylate constituent units, the protective sheet 10 can be cured by irradiation with active energy rays (such as ultraviolet light) before the pickup process. Specifically, irradiation with active energy rays such as ultraviolet light generates radicals from the photopolymerization initiator, and the action of these radicals causes a crosslinking reaction between the acrylic polymers. This reduces the adhesive strength of the protective sheet 10 before irradiation, and allows for the smooth peeling of small pieces 10' of the protective sheet from the semiconductor chip X. Ultraviolet light, radiation, and electron beams are used as the active energy rays.

[0104] Specifically, the polymerizable group-containing (meth)acrylate constituent unit may have a molecular structure in which the isocyanate group of an isocyanate group-containing (meth)acrylate monomer is urethane-bonded to the hydroxyl group in the hydroxyl group-containing (meth)acrylate constituent unit described above.

[0105] Polymerizable group-containing (meth)acrylate constituent units can be prepared after polymerization of acrylic polymers. For example, after copolymerization of an alkyl (meth)acrylate monomer and a hydroxyl group-containing (meth)acrylate monomer, the above polymerizable group-containing (meth)acrylate constituent units can be obtained by urethane reaction between the hydroxyl groups in some of the hydroxyl group-containing (meth)acrylate constituent units and the isocyanate groups of the isocyanate group-containing polymerizable monomer.

[0106] The above-mentioned isocyanate group-containing (meth)acrylate monomer preferably has one isocyanate group and one (meth)acryloyl group in its molecule. Examples of such monomers include 2-isocyanatoethyl (meth)acrylate.

[0107] The protective sheet 10 may further contain an isocyanate compound having multiple isocyanate groups in its molecule. This allows for the crosslinking reaction between acrylic polymers in the protective sheet 10 to proceed. Specifically, the crosslinking reaction via the isocyanate compound can be carried out by reacting one isocyanate group of the isocyanate compound with a hydroxyl group of an acrylic polymer, and the other isocyanate group with a hydroxyl group of another acrylic polymer.

[0108] Examples of isocyanate compounds include diisocyanates such as aliphatic diisocyanates, alicyclic diisocyanates, or aromatic aliphatic diisocyanates. Furthermore, examples of isocyanate compounds include polymerized polyisocyanates such as dimers and trimers of diisocyanates, and polymethylene polyphenylene polyisocyanates.

[0109] In addition, examples of isocyanate compounds include polyisocyanates obtained by reacting an excess amount of the above-mentioned isocyanate compound with an active hydrogen-containing compound. Examples of active hydrogen-containing compounds include active hydrogen-containing low molecular weight compounds and active hydrogen-containing high molecular weight compounds. In addition, allophanate-modified polyisocyanates, biuret-modified polyisocyanates, and the like can also be used as isocyanate compounds. The above isocyanate compounds can be used individually or in combination of two or more.

[0110] As the above isocyanate compound, a reaction product of an aromatic diisocyanate and an active hydrogen-containing low molecular weight compound is preferred. Since the reaction rate of the isocyanate group in the reaction product of aromatic diisocyanate is relatively slow, excessive hardening of the protective sheet 10 containing such a reaction product is suppressed. As the above isocyanate compound, one having three or more isocyanate groups in the molecule is preferred.

[0111] The polymerization initiator contained in the protective sheet 10 is a compound that can initiate a polymerization reaction in response to applied heat or light energy. The presence of the polymerization initiator in the protective sheet 10 allows for the promotion of crosslinking reactions between acrylic polymers when thermal or light energy is applied to the protective sheet 10. Specifically, it enables the initiation of polymerization reactions between polymerizable groups within acrylic polymers having polymerizable group-containing (meth)acrylate constituent units, thereby curing the protective sheet 10. This reduces the adhesive strength of the protective sheet 10, allowing for easy removal of the cured protective sheet fragments 10' from the semiconductor chip X during the removal process. For example, photopolymerization initiators or thermal polymerization initiators can be used as polymerization initiators. Commonly available commercially produced products can be used as polymerization initiators.

[0112] The protective sheet 10 in the second embodiment can be manufactured as follows. Specifically, an acrylic polymer is synthesized, and the protective sheet 10 is manufactured by volatilizing the solvent from an adhesive composition containing the acrylic polymer, an isocyanate compound, a polymerization initiator, and a solvent.

[0113] In the synthesis of acrylic polymers, for example, acrylic polymer intermediates are synthesized by radical polymerization of alkyl (meth)acrylate monomers and hydroxyl group-containing (meth)acrylate monomers. Radical polymerization can be carried out by general methods. For example, acrylic polymer intermediates can be synthesized by dissolving each of the above monomers in a solvent, stirring while heating, and adding a polymerization initiator. Polymerization may be carried out in the presence of a chain transfer agent to adjust the molecular weight of the acrylic polymer. Next, some of the hydroxyl groups in the hydroxyl group-containing (meth)acrylate constituent units contained in the acrylic polymer intermediate are bonded to the isocyanate groups of the isocyanate group-containing polymerizable monomer through a urethane reaction. As a result, some of the constituent units of the hydroxyl group-containing (meth)acrylate become constituent units of the polymerizable group-containing (meth)acrylate. The urethane reaction can be carried out by a general method. For example, an acrylic polymer intermediate and an isocyanate group-containing polymerizable monomer are stirred while heating in the presence of a solvent and a urethane catalyst. This allows some of the hydroxyl groups of the acrylic polymer intermediate to be bonded to the isocyanate groups of the isocyanate group-containing polymerizable monomer by urethane bonding.

[0114] Next, an acrylic polymer, an isocyanate compound, and a polymerization initiator are dissolved in a solvent to prepare an adhesive composition. The viscosity of the composition can be adjusted by changing the amount of solvent. Then, the adhesive composition is applied to a release liner 15 (described later). Common application methods such as roll coating, screen coating, and gravure coating are used. The applied adhesive composition is solidified by desolvation treatment and solidification treatment, etc., to produce a protective sheet 10.

[0115] In the second embodiment, the protective sheet 10 may have a release liner 15 superimposed on at least one side, either before use or during use, as shown in Figure 2A. The release liner 15 is configured to be easily peeled off from the protective sheet 10. More specifically, a release liner 15 may be attached to at least one of the surfaces of the protective sheet 10 that overlap with the circuit surface of the semiconductor wafer W, or to the opposite surface, before use or during use. The release liner 15 is used to protect the protective sheet 10 and is peeled off and removed after the protective sheet 10 is attached to the semiconductor wafer W.

[0116] The above-mentioned release liner 15 can be used as a support material for supporting the protective sheet 10. The release liner 15 is preferably used when stacking the protective sheet 10 on the semiconductor wafer W. Specifically, the protective sheet 10 can be attached to the semiconductor wafer W by stacking the protective sheet 10 on the semiconductor wafer W while the release liner 15 and the protective sheet 10 are stacked together. After that, the release liner 15 may be peeled off. Alternatively, a release liner 15 may be attached to the protective sheet 10, so that the protective sheet 10 is positioned between two release liners 15.

[0117] The thickness of the release liner 15 may be, for example, 25 μm or more and 75 μm or less. The release liner 15 is preferably a resin film such as polyethylene terephthalate resin film. The release liner 15 is preferably light-transmitting (ultraviolet-transmitting). As the release liner 15, for example, a plastic film or paper that has been surface-treated with a release agent such as silicone-based, long-chain alkyl-based, fluorine-based, or molybdenum sulfide can be used. Commercially available products such as "Diafoil MRA50" (biaxially oriented polyester film manufactured by Mitsubishi Chemical Corporation) can be used as the release liner 15.

[0118] The protective sheet 10 in the second embodiment may, for example, contain a curable compound that hardens by active energy rays as described above, or it may contain a curable compound that can initiate a curing reaction by heat treatment. Examples of curable compounds that can initiate a curing reaction by heat treatment include thermosetting resins. Furthermore, examples of curable compounds that harden with active energy rays include ultraviolet-curable polyurethane resins. Furthermore, curable compounds can also include curable silicone resin compositions.

[0119] Examples of thermosetting resins include epoxy resins, phenolic resins, amino resins, unsaturated polyester resins, and thermosetting polyimide resins. One or more of these thermosetting resins may be used.

[0120] Examples of the epoxy resins mentioned above include bisphenol A type, bisphenol F type, bisphenol S type, brominated bisphenol A type, hydrogenated bisphenol A type, bisphenol AF type, biphenyl type, naphthalene type, fluorene type, phenol novolac type, orthocresol novolac type, trishydroxyphenylmethane type, tetraphenyloleethane type, hydantoin type, trisglycidyl isocyanurate type, or glycidylamine type epoxy resins.

[0121] Phenolic resins can act as curing agents for epoxy resins. Examples of phenolic resins include novolac-type phenolic resins, resol-type phenolic resins, and polyoxystyrenes such as polyparaoxystyrene. Examples of novolac-type phenolic resins include phenol novolac resin, phenol aralkyl resin, cresol novolac resin, tert-butylphenol novolac resin, and nonylphenol novolac resin. The above-mentioned phenolic resin may be of one type or two or more types.

[0122] Examples of UV-curable polyurethane resins include compounds having a main chain composed of multiple urethane bonds and side chains containing (meth)acrylic groups in their molecules. Examples of commercially available UV-curable polyurethane resins include the "8UH series" manufactured by Taisei Fine Chemical Co., Ltd.

[0123] Examples of curable silicone resin compositions include compositions containing a silicone resin having a silanol group in its molecule that can be cured by a condensation reaction of the silanol group, compositions that can be cured by a hydrosilylation reaction between an alkenyl group and a SiH group, and compositions containing a silicone resin having a polymerizable unsaturated group in its molecule that can be cured by a radical polymerization reaction.

[0124] In the second embodiment, the elongation at break and the strength at break of the protective sheet 10 before and after curing treatment may be the same as those of the protective sheet 10 in the first embodiment described above.

[0125] In the second embodiment, the adhesion of the protective sheet 10 to the semiconductor wafer W before and after curing can be measured by the peeling force described in the first embodiment. Such peeling force may be the same as the peeling force of the protective sheet 10 used in the first embodiment.

[0126] In the second embodiment, the protective sheet 10 preferably has a tensile modulus (tensile storage modulus E') of 1.0 MPa or more and 1.0 GPa or less at 25°C before curing treatment. Furthermore, it is preferable that the tensile modulus (tensile storage modulus E') of 2.0 MPa or more and 1.0 GPa or less at -15°C before curing treatment. In the second embodiment, the protective sheet 10 preferably has a tensile modulus (tensile storage modulus E') of 5.0 MPa or more and 10.0 GPa or less at 25°C after curing treatment. Furthermore, it is preferable that the tensile modulus (tensile storage modulus E') of 10.0 MPa or more and 10.0 GPa or less at -15°C after curing treatment.

[0127] In the second embodiment, steps not specifically mentioned can be carried out in the same manner as in the steps of the first, third, fourth, or fifth embodiment.

[0128] Next, the third embodiment will be described in detail. Note that the same descriptions as those for the first and second embodiments will not be repeated for the third embodiment. Unless otherwise specified, the same operations as in the first or second embodiment may be performed in the third embodiment.

[0129] "Third Embodiment" The third embodiment of the semiconductor device manufacturing method differs from the second embodiment mainly in that, in the mounting process, instead of attaching the semiconductor wafer W, which is stacked on the glass carrier G, to the adhesive layer 22 of the dicing tape 20, the semiconductor wafer W is attached to the adhesive layer 22 while the semiconductor wafer W and the protective sheet 10 are stacked together.

[0130] More specifically, in the semiconductor device manufacturing method of the third embodiment, a semiconductor wafer W attached to a backgrind tape B is prepared as shown in Figure 5A.

[0131] In the protection process, a protective sheet 10 is attached to the semiconductor wafer W, as shown in Figure 5B. At this time, the protective sheet 10 is attached to one side of the semiconductor wafer W, and backgrain tape is attached to the other side. The circuit components are arranged on one side of the semiconductor wafer W.

[0132] Next, in the mounting process, as shown in Figure 5C, the backgrin tape is peeled off the semiconductor wafer W while the semiconductor wafer W and the protective sheet 10 are overlapping. As a result, the semiconductor wafer W and the protective sheet 10 overlap, and the other side of the semiconductor wafer W (the non-circuit side, not the circuit side) is exposed.

[0133] In the mounting process of the third embodiment, as shown in Figure 5D, with the semiconductor wafer W and the protective sheet 10 overlapping, the other exposed surface of the semiconductor wafer W is attached to the adhesive layer 22 of the dicing tape 20. At this time, since the protective sheet 10 is attached to one side of the semiconductor wafer W, and the release liner 15 is also attached, the semiconductor wafer W can be pressed against the adhesive layer 22 via the protective sheet 10 and the release liner 15. Thus, the semiconductor wafer W can be attached to the adhesive layer 22 while protecting the circuit surface of the semiconductor wafer W.

[0134] In the mounting process, it is preferable to place the protective sheet 10 on the semiconductor wafer W with the release liner 15 laminated with the protective sheet 10, and to peel off the release liner 15 from the protective sheet 10 before the protective sheet 10 is broken down into smaller pieces in the expanding process.

[0135] In the third embodiment, steps not specifically mentioned can be carried out in the same manner as in the first, second, fourth, or fifth embodiment. In addition, in the third embodiment, and in the fourth and fifth embodiments described below, the removal process described in the first embodiment may be carried out, or the removal process described in the second embodiment may be carried out. In other words, in each removal process in the third to fifth embodiments, the small pieces 10' of the protective sheet may be removed using a liquid containing water in the same manner as described above, or the small pieces 10' of the protective sheet may be removed using a peel-off adhesive tape T.

[0136] Next, the fourth embodiment will be described in detail. Note that the same explanations as those given for the first to third embodiments will not be repeated for the fourth embodiment. Unless otherwise specified, the same operations as those in the first to third embodiments may be performed in the fourth embodiment.

[0137] "Fourth Embodiment" The method for manufacturing a semiconductor device according to the fourth embodiment differs from the third embodiment mainly in that, before the mounting process, laser light is irradiated onto the semiconductor wafer W to form a vulnerable area inside the wafer. For details, the method for manufacturing the semiconductor device of the fourth embodiment is as follows: A stealth processing step is performed to prepare the semiconductor wafer W for fragmentation by forming a vulnerable area inside the semiconductor wafer W to which backgrind tape B has been attached using laser light, and A protection step to protect the circuit surface of a semiconductor wafer W by attaching a protective sheet 10 to one side of the semiconductor wafer W, A mounting step in which the other side of the semiconductor wafer W (for example, the side opposite to the circuit side) is attached to the dicing tape 20, thereby fixing the semiconductor wafer W to the dicing tape 20, A curing process in which the protective sheet 10 is cured by a curing treatment such as irradiation with active energy rays to reduce the adhesive strength of the protective sheet 10, An expansion process in which the semiconductor wafer W and protective sheet 10 are broken into smaller pieces by stretching the dicing tape 20, A removal process to remove small pieces 10' of the protective sheet attached to the semiconductor chip X, A pickup process to remove the semiconductor chip X by separating it from the adhesive layer 22, The process includes a bonding step of bonding a semiconductor chip X to an adherend.

[0138] In the fourth embodiment, as shown in Figure 6A, a semiconductor wafer W is prepared in a state where it is overlapped with a backgrind tape B. In this state, the semiconductor wafer W is thinned to a desired thickness by, for example, backgrinding while the backgrind tape B is attached.

[0139] In the stealth processing step of the fourth embodiment, as shown in Figure 6B, a laser beam is irradiated onto the semiconductor wafer W in a state where it is overlapping with the backgrind tape B. The backgrind tape B is attached, for example, to the side of the semiconductor wafer W opposite to the circuit side. The laser beam is irradiated, for example, from the circuit side of the semiconductor wafer W.

[0140] In the protection step of the fourth embodiment, as in the third embodiment, a protective sheet 10 is attached to the semiconductor wafer W as shown in Figure 6C. As a result, the protective sheet 10 overlaps one side (circuit side) of the semiconductor wafer W, and the backgrind tape B overlaps the other side. Then, the backgrind tape B is peeled off from the semiconductor wafer W. Note that a release liner 15 may overlap the protective sheet 10 as shown in Figure 6C.

[0141] Subsequently, as shown in Figures 6D and 6E, the mounting process can be carried out in the same manner as in the second embodiment (see also Figure 4A). Then, as shown in Figure 6F, the protective sheet 10 can be subjected to a curing treatment in the same manner as in the second embodiment (see also Figure 4C).

[0142] In the fourth embodiment, steps not specifically mentioned can be carried out in the same manner as in the steps of the first, second, or third embodiment.

[0143] Finally, the fifth embodiment will be described in detail. Note that the same explanations as those for the first to fourth embodiments will not be repeated for the fifth embodiment. Unless otherwise specified, the same operations as those in the first to fourth embodiments may be performed in the fifth embodiment.

[0144] "Fifth Embodiment" The fifth embodiment of the semiconductor device manufacturing method differs from the other embodiments mainly in that a protective sheet 10 is placed between the semiconductor wafer W and the backgrind tape B, and the semiconductor wafer W is then attached to the adhesive layer 22 of the dicing tape 20. More specifically, in the semiconductor device manufacturing method of the fifth embodiment, as shown in Figure 7A, a protective sheet 10 is placed on the circuit surface of a semiconductor wafer W, and then a backgrind tape B is placed on top of the protective sheet 10. Alternatively, the backgrind tape B may be placed on one side of the protective sheet 10 before the semiconductor wafer W is placed on the other side of the protective sheet 10, or the semiconductor wafer W may be placed on the other side of the protective sheet 10 before the backgrind tape B is placed on one side of the protective sheet 10.

[0145] With the semiconductor wafer W, protective sheet 10, and backgrind tape B stacked, grinding is performed on the side of the semiconductor wafer W where no circuit components are placed. Specifically, as shown in Figure 7A, grinding (backgrinding) is performed with the grinding pad K until the semiconductor wafer W reaches a predetermined thickness. The thickness of the semiconductor wafer W is reduced to a predetermined thickness by the grinding process (see Figure 7B).

[0146] Next, in the mounting process, the side of the ground semiconductor wafer W (the side without circuit components) is placed on top of the adhesive layer 22 of the dicing tape 20. At this time, as shown in Figure 7C, a protective sheet 10 is attached to the circuit side of the semiconductor wafer W, and a backgrind tape B is attached to the protective sheet 10.

[0147] After the semiconductor wafer W is placed on the adhesive layer 22 of the dicing tape 20, the stealth processing step can be performed in the same manner as described above. Then, the protective sheet 10 attached to the semiconductor wafer W is separated from the backgrind tape B and the backgrind tape B is removed (see Figure 7D). Alternatively, the stealth processing step may be performed after the backgrind tape B has been removed.

[0148] Subsequently, a curing process to harden the protective sheet 10 and reduce its adhesive strength, an expansion process to break down the semiconductor wafer W and protective sheet 10 into smaller pieces, a removal process to remove the small pieces 10' of the protective sheet attached to the semiconductor chip X, a pickup process to remove the semiconductor chip X, and a bonding process to bond the semiconductor chip X to the substrate can be carried out in the same manner as described above.

[0149] The method for manufacturing an electronic component device (e.g., a semiconductor device) according to embodiments of the present invention is as illustrated above, but the present invention is not limited to the method for manufacturing an electronic component device as illustrated above. In other words, various forms used in general manufacturing methods for electronic component devices can be adopted, to the extent that they do not impair the effects of the present invention.

[0150] For example, as described above, the substrate (e.g., semiconductor wafer) used in the manufacturing method of the present invention may be a substrate in which circuit components are arranged on both sides, as described in the first embodiment, or it may be a substrate in which circuit components are arranged on only one side, as described in the other embodiments. In other words, one side of the substrate manufactured in the manufacturing method of the present invention may be a circuit surface, or both sides may be circuit surfaces.

[0151] The matters disclosed herein include the following: (I) A step of placing a protective sheet to protect the circuit components on at least one surface of the substrate, which is the circuit surface on which the circuit components are arranged, The process involves dividing the laminate, in which the substrate and the protective sheet overlap, into smaller pieces with spacing in the planar direction, thereby producing small pieces of the laminate in which the small pieces of the substrate and the small pieces of the protective sheet overlap. A method for manufacturing an electronic component device, comprising the step of removing a small piece of the protective sheet that overlaps the circuit surface of the substrate chip. (II) A method for manufacturing an electronic component device according to (I) above, further comprising the step of arranging the circuit surface of the substrate chip toward the adherend and joining the substrate chip and the adherend. (III) The protective sheet contains a water-soluble polymer compound. The method for manufacturing an electronic component device according to (I) or (II) above, wherein in the removal step, the plurality of small pieces of the protective sheet are removed by bringing a liquid containing water into contact with the plurality of small pieces of the protective sheet and dissolving at least a portion of each small piece in the liquid. (IV) A method for manufacturing an electronic component device according to (III) above, further comprising a step of increasing the humidity of the gas in contact with the circuit surface before the removal step. (V) The method for manufacturing an electronic component device according to (I) or (II) above, wherein in the removal step, the multiple small pieces of the protective sheet are removed together with the adhesive tape by peeling off the adhesive tape attached to the multiple small pieces of the protective sheet. (VI) The protective sheet comprises a curable composition, A method for manufacturing an electronic component device according to (V) above, comprising curing the protective sheet that is superimposed on the substrate by a curing process, and then dividing the laminate of the substrate and the protective sheet into smaller pieces. (VII) The electrode portions, which serve as circuit components, are arranged on both surfaces of the substrate chip, respectively, and are electrically connected to each other. The method for manufacturing an electronic component device according to any one of claims (II) to (VI), wherein in the bonding step, a plurality of the substrate chips are stacked and the electrode portion of one of the substrate chips that is the adherend is directly connected to the electrode portion of the other substrate chip.

[0152] The matters disclosed herein further include: (1) A step of placing a protective sheet to protect the circuit components on at least one side of a semiconductor wafer, which is the circuit side on which the circuit components are arranged, A step of dividing the stacked semiconductor wafer and protective sheet into smaller pieces with spacing in the planar direction, thereby producing a small piece of the stack in which the small pieces of semiconductor chips and the small pieces of protective sheet overlap the semiconductor wafer, A method for manufacturing a semiconductor device, comprising the step of removing a small piece of the protective sheet that is overlapping the circuit surface of the semiconductor chip. (2) A method for manufacturing a semiconductor device according to (1) above, further comprising the step of arranging the circuit surface of the semiconductor chip toward the adherend to join the semiconductor chip and the adherend. (3) A method for manufacturing a semiconductor device according to (1) or (2) above, wherein the laminate of the semiconductor wafer and the protective sheet is placed on one side of the dicing tape and the dicing tape is stretched in the planar direction, thereby dividing the laminate into small pieces and producing small pieces of the laminate. (4) The protective sheet contains a water-soluble polymer compound. A method for manufacturing a semiconductor device according to any one of (1) to (3) above, wherein in the removal step, the plurality of small pieces of the protective sheet are removed by bringing a liquid containing water into contact with the plurality of small pieces of the protective sheet and dissolving at least a portion of each small piece in the liquid. (5) The method for manufacturing a semiconductor device according to (4) above, wherein the water-soluble polymer compound comprises at least one of polyvinyl alcohol and polyvinylpyrrolidone. (6) A method for manufacturing an electronic component device according to (5) above, further comprising a step of increasing the humidity of the gas in contact with the circuit surface before the removal step. (7) The method for manufacturing a semiconductor device according to any one of (1) to (3) above, wherein the removal step involves removing the adhesive tape attached to the multiple small pieces of the protective sheet, thereby removing the multiple small pieces of the protective sheet together with the adhesive tape. (8) The protective sheet comprises a curable composition, A method for manufacturing a semiconductor device according to (7) above, comprising curing the protective sheet that is superimposed on the semiconductor wafer by a curing process, and then dividing the laminate of the semiconductor wafer and the protective sheet into smaller pieces. (9) The method for manufacturing a semiconductor device according to (8) above, wherein the curable composition comprises at least one curable compound selected from the group consisting of compounds containing a polymerizable carbon-carbon double bond in the molecule, compounds containing a glycidyl group in the molecule, compounds containing an isocyanate group in the molecule, compounds containing a carboxyl group in the molecule, and compounds containing a hydroxyl group in the molecule. (10) The semiconductor chip has electrode portions arranged on both surfaces and which are electrically connected to each other. A method for manufacturing a semiconductor device according to any one of (1) to (9) above, wherein in the bonding step, at least two of the semiconductor chips are stacked and the electrode portion of one of the semiconductor chips which is the adherend is directly connected to the electrode portion of the other semiconductor chip. [Examples]

[0153] The present invention will be further explained with experimental examples, but the present invention is not limited to these.

[0154] As an example of a method for manufacturing electronic components and devices, a semiconductor device was manufactured as follows.

[0155] A commercially available dicing tape (product name "V-12SR," manufactured by Nitto Denko Corporation) was used. Additionally, a bare silicon wafer was used instead of a semiconductor wafer. The protective sheet was prepared as follows: When preparing the protective sheet, a protective sheet composition containing a solvent was applied to one side of the release liner, and the solvent was evaporated to laminate the protective sheet and the release liner. Furthermore, the release liner was bonded to the protective sheet, so that the protective sheet was positioned between the two release liners. A silicon bare wafer (50 μm thick, 300 mm in diameter, disc-shaped) was used instead of a semiconductor wafer.

[0156] [Example 1] (Preparation of protective sheet a) A commercially available polyvinyl alcohol (PVA) with a saponification degree of 65 (mol%) and an average degree of polymerization of 240 was prepared. This polyvinyl alcohol (PVA) was dispersed in water, then heated to 90°C to dissolve and prepare an aqueous PVA solution. This aqueous PVA solution was applied to a release liner a (PET film, 50 μm thick). Release liner a had a surface treated with silicone release agent, and the aqueous PVA solution was applied to this surface using an applicator. Furthermore, it was dried at 110°C for 2 minutes to form a 10 μm thick protective sheet overlapping one side of release liner a. Then, release liner b (PET film, 25 μm thick) was placed on the exposed surface of the protective sheet. Release liner b also had a surface treated with silicone release agent, and this side was attached to the protective sheet. In this way, a protective sheet a sandwiched between two release liners was prepared. (Mounting and protection processes) The release liner b was peeled off and removed from the fabricated protective sheet a, exposing one side of protective sheet a. This exposed side was then attached to the silicon bare wafer that was overlapping the dicing tape. In detail, the silicon bare wafer and the glass carrier were bonded together, and the wafer was then attached to dicing tape. Subsequently, the glass carrier was peeled off the wafer, exposing one side of the wafer. The exposed surface of the wafer (the surface opposite to the contact surface with the dicing tape) was bonded to the same exposed surface of the protective sheet a from which the release liner b had been peeled off. A Nitto Seiki MV3000 vacuum mounter, heated to a stage temperature of 90°C, was used for bonding. In this way, the dicing tape, silicon bare wafer, and protective sheet a were stacked in this order. (Stealth processing) Next, a DFL7361 from Disco Corporation was used to irradiate a bare silicon wafer with laser light to form a weak area inside the wafer. After that, the delamination liner a was peeled off. (Expanding process) Next, using a DDS2300 manufactured by Disco Corporation, the wafer and protective sheet laminate was cleaved into small pieces at -15°C and 200 mm / s, yielding small pieces (10 mm x 10 mm rectangular) of chips (dies) and protective sheets. (Removal process) Subsequently, in order to remove the protective sheet, water was sprayed onto the protective sheet using the water-washing mechanism of the DISCO DDS2300 cutting device, bringing the protective sheet into contact with water. This exposed one surface (temporary circuit side) of the chip (die).

[0157] [Example 2] (Preparation of protective sheet b) In a reaction vessel equipped with a condenser, a nitrogen inlet, a thermometer, and a stirring device, 11 parts by mass of hydroxyethyl acrylate (HEA) as monomers, 89 parts by mass of 2-ethylhexyl acrylate (2EHA), and 0.2 parts by mass of azobisisobutyronitrile (AIBN) as a thermal polymerization initiator were added. Furthermore, butyl acetate was added as a reaction solvent so that the monomer concentration was 36% by mass. Then, acrylic polymer solution A was synthesized by polymerizing under a nitrogen atmosphere at 62°C for 4 hours and at 75°C for 2 hours. To this acrylic polymer solution A, 13 parts by mass of 2-methacryloyloxyethyl isocyanate (product name "Karenz MOI", manufactured by Showa Denko Corporation) and 0.07 parts by mass of dibutyltin dilaurate were added. Then, an addition reaction treatment was carried out at 50°C for 12 hours under an air stream to obtain acrylic polymer solution A'. Next, to 100 parts by mass of acrylic polymer solution A', 0.8 parts by mass of a polyisocyanate compound (product name "Takenate D-101A", manufactured by Mitsui Chemicals, Inc.) as a crosslinking agent and 5 parts by mass of a photopolymerization initiator (product name "Omnirad127", manufactured by IGM Corporation) were added to prepare an adhesive solution (hereinafter referred to as adhesive solution A). Next, using an applicator, the above-mentioned adhesive solution A was applied to the silicone-release surface of release liner a (PET film, 50 μm thick) which had a silicone-release treated surface. A drying treatment was performed at 120°C for 2 minutes to form a 30 μm thick protective sheet b that overlapped one side of release liner a. Then, the silicone-release treated surface of release liner b (PET film, 25 μm thick) which had a silicone-release treated surface was bonded to the exposed surface of protective sheet b. A UV-curable protective sheet was prepared by storing it at 50°C for 24 hours. (Mounting and protection processes) The release liner b was peeled off the fabricated protective sheet, exposing one side of the protective sheet. This exposed side was then attached to the silicon bare wafer, which was overlapping the dicing tape. In detail, the silicon bare wafer and the glass carrier G were bonded together, and the wafer was then attached to dicing tape. Subsequently, the glass carrier G was peeled off the wafer, exposing one side of the wafer. The exposed surface of the wafer (the surface opposite to the contact surface with the dicing tape) was bonded to the same exposed surface of the protective sheet b from which the release liner b had been peeled off. A Nitto Seiki MV3000 vacuum mounter, heated to a stage temperature of 30°C, was used for bonding. In this way, the dicing tape, silicon bare wafer, and protective sheet a were stacked in this order. (Stealth processing) A DFL7361 manufactured by Disco Corporation was used to irradiate a wafer with laser light, creating a vulnerable area inside the wafer. (Hardening treatment) Subsequently, 300 mJ / cm² of water was applied to the protective sheet from the opposite side of where the dicing tape was placed (the side with release liner a). 2 The protective sheet was cured by irradiating it with ultraviolet light. Then, the release liner a was peeled off from the protective sheet. (Expanding process) Next, using a DDS2300 manufactured by Disco Corporation, the wafer and protective sheet laminate was cleaved into smaller pieces at -15°C and 200 mm / s, yielding the fragmented chips (dies) and protective sheets. (Removal process) Next, to remove the fragmented protective sheet, a laminator was used to apply a release adhesive tape (adhesive tape product name "No.360UL") to the UV-curable protective sheet overlapping the chip (die). Then, the release adhesive tape was peeled off. This removed the protective sheet along with the release adhesive tape, exposing one surface (temporary circuit surface) of the chip (die).

[0158] <Measurement of physical properties of protective sheets> (Silicone adhesion) The peeling force of the protective sheet onto a silicon bare wafer was measured at 25°C using the measurement conditions and methods described above. (Breaking strength and elongation at breaking) The breaking strength and breaking elongation were measured at -15°C using the measurement conditions and methods described above. (Tensile modulus of elasticity) The tensile modulus was measured at -15°C and 25°C, respectively, using the measurement conditions and methods described above. (Surface free energy) The surface free energy of the protective sheet at 25°C was calculated using the measurement conditions, measurement method, and calculation method described above (however, only in Example 1).

[0159] [Comparative Example] The chip (die) was fabricated in the same manner as in Example 1 or Example 2, except that the protective sheet and the silicon bare wafer were not bonded together. Specifically, a DFL7361 manufactured by Disco Corporation was used to irradiate a silicon bare wafer attached to a dicing tape with laser light to form a weak area inside the wafer. Subsequently, the wafer was cleaved into small pieces using a DDS2300 manufactured by Disco Corporation at -15°C and 200 mm / s.

[0160] <Evaluation: Adhesion of foreign matter on the chip (die) surface> The surface of the exposed chip (die) (the side from which the protective sheet has been removed) was observed with a digital microscope, and the number of foreign objects in a randomly selected 10 x 10 mm square area was counted. A count of 10 or more foreign objects was judged as defective (×), and a count of less than 10 foreign objects was judged as good (○). Figures 8 and 9 show photographs of the surface of the chip (die) with foreign matter attached in Example 1 and the Comparative Example, respectively.

[0161] The manufacturing methods for each example and comparative example were carried out as described above. Details of the protective sheets used in each manufacturing method and the evaluation results are shown in Table 1.

[0162] [Table 1]

[0163] As can be seen from the evaluation results above, by manufacturing a semiconductor device using the semiconductor device manufacturing method of the embodiment, the adhesion of foreign matter to the circuit surface of the chip (die) was suppressed. This allows for close contact and reliable electrical conductivity between the electrode portion of the adherend and the electrode portion of the chip (die). In particular, when multiple semiconductor chips having electrode portions formed on both sides and conductive with respect to each other are stacked, the electrode portions of adjacent semiconductor chips can be brought into close contact and reliable electrical conductivity can be ensured. Therefore, it is considered that the reliability of the conductive performance of the manufactured semiconductor device can be sufficiently maintained.

[0164] By implementing the manufacturing method for electronic component devices as described in the above embodiment, semiconductor devices in which multiple semiconductor chips are stacked can be manufactured efficiently. [Industrial applicability]

[0165] The method for manufacturing electronic component devices of the present invention is suitably used, for example, to manufacture semiconductor devices equipped with semiconductor integrated circuits. [Explanation of symbols]

[0166] 10: Protective sheet, 10': Small piece of protective sheet, 15: Peel-off liner, 20: Dicing tape, 21: Base material layer, 22: Adhesive layer, G: Glass carrier, W: Semiconductor wafer, X: Semiconductor chip, V: Through-hole via, D: Electrode section T: Removable adhesive tape, B: Backgrind tape.

Claims

1. a step of overlaying a protective sheet for protecting the circuit components on at least one surface of the substrate, the circuit surface on which the circuit components are arranged; a step of dividing a laminate in which the substrate and the protective sheet are overlapped into small pieces at intervals in a surface direction, thereby producing small pieces of the laminate in which substrate chips obtained by dividing the substrate into small pieces and small pieces of the protective sheet are overlapped; removing a small piece of the protective sheet overlapping the circuit surface of the substrate chip, In the step of overlapping the protective sheet, one release liner is peeled from one side of the protective sheet, with release liners overlapping both sides of the protective sheet, and the protective sheet laminated on the other release liner is then overlapped on the circuit surface; After the step of overlapping the protective sheets, the other release liner is peeled off and removed from the other surface of the protective sheet. A method for manufacturing an electronic component device.

2. The method for manufacturing an electronic component device according to claim 1 , further comprising the step of placing the circuit surface of the substrate chip facing the adherend and bonding the substrate chip to the adherend.

3. the protective sheet contains a water-soluble polymer compound, 3. The method for manufacturing an electronic component device according to claim 1, wherein the removing step removes the plurality of small pieces of the protective sheet by contacting a liquid containing water with the plurality of small pieces of the protective sheet and dissolving at least a portion of each small piece in the liquid.

4. The electrode portions as the circuit components arranged on both surfaces of the substrate chip are electrically connected to each other, 3. The method for manufacturing an electronic component device according to claim 2, wherein in the joining step, at least two of the substrate chips are stacked and the electrode portions of one of the substrate chips, which is the adherend, are directly connected to the electrode portions of the other substrate chip.

Images