Method for manufacturing a protective sheet and electronic component device

Abstract

The present invention provides a protective sheet, etc., wherein the protective sheet has a protective layer on the protective surface to be adhered to a substrate, the protective layer contains a water-soluble compound, and the protective layer has an adhesion force of 0.5N / 10mm or more to the silicon wafer.

Description

[0001] Cross-references to related applications This application claims priority to Japanese Patent Application No. 2023-208689, which is incorporated herein by reference. Technical Field

[0002] This invention relates, for example, to a protective sheet having a protective layer on a protective surface to be bonded to a substrate. Furthermore, this invention relates to a method for manufacturing an electronic component device, comprising a step of removing the protective sheet after bonding the protective layer of the protective sheet to the protective surface of a substrate. Background Technology

[0003] Previously, protective sheets for manufacturing electronic components were known. Such protective sheets, for example, include: a protective layer to be attached to the protective surface of the electronic component, and a substrate layer overlapping one side of the protective layer.

[0004] Such protective sheets are used, for example, in the manufacturing process of electronic component devices. This manufacturing process includes, for example, a step of mounting and temporarily fixing a component, etc., as a workpiece, to one side of a substrate; a step of attaching the protective layer of the protective sheet to the other side of the substrate (the side to be protected); a step of processing the mounted component, etc.; a step of removing the component, etc., from the substrate; and a step of removing the protective layer from the substrate. For example, as described above, the protective sheet is used in a manner where it is first attached to the substrate and then removed from it.

[0005] As a protective sheet used in the manufacturing method of the above-mentioned electronic component device, there is a known protective sheet that has a protective layer formed of a resin composition containing an oxyalkylene polyvinyl alcohol resin with a saponification degree of 55 mol% or less, and a substrate layer (for example, Patent Document 1).

[0006] The protective sheet described in Patent Document 1 can be used by attaching the protective layer to one side (the side to be protected) of a substrate. Except when the substrate layer of the protective sheet described in Patent Document 1 is a release film, it has a high degree of adhesion to the protective layer.

[0007] According to the protective sheet described in Patent Document 1, the protective layer can protect the surface of the object being protected during temporary fixation, and the protective layer can be removed with water after temporary fixation.

[0008] Existing technical documents Patent documents Patent Document 1: Japanese Patent Application Publication No. 2021-161735 Summary of the Invention

[0009] The problem that the invention aims to solve However, in the protective sheet described in Patent Document 1, when unevenness is formed on the protected surface of the substrate due to bumps or the like, the protective layer may not deform sufficiently with the unevenness, and sometimes a part of the protective layer cannot enter the recess. That is, the embedding performance of the protective layer may not be good.

[0010] Furthermore, the protective sheet described in Patent Document 1 can be used in a manner where the substrate layer is peeled off from the protective layer before the protective layer is removed with water, leaving only the protective layer on the protected surface of the substrate. It should be noted that even when only the protective layer is attached to the protected surface without a substrate layer, there is a method of use where the protective layer is first covered with cover tape, and then only the cover tape is peeled off. In such cases, when the substrate layer or cover tape is peeled off from the protective layer, due to the lower adhesion between the protected surface of the substrate and the protective layer, a portion of the protective layer may remain attached to the peeled substrate layer or cover tape.

[0011] To prevent such problems, it is desirable to have a protective sheet that has good embeddability, good peel resistance, adheres well to the surface to be protected, and can be easily removed using an aqueous liquid.

[0012] However, it cannot be said that sufficient research has been conducted on protective sheets that have good embedding properties, good peel resistance to the protective surface of the substrate, and are easy to remove using aqueous liquids.

[0013] Therefore, the technical problem of the present invention is to provide a protective sheet that has good embedding properties, good peel resistance when attached to the protective surface of the substrate, and is easily removed using an aqueous liquid. Furthermore, the technical problem of the present invention is to provide a method for manufacturing an electronic component device using the above-described protective sheet.

[0014] Solution for solving the problem To solve the above-mentioned technical problems, the protective sheet of the present invention has a protective layer on the protective surface to be adhered to the substrate, the protective layer containing a water-soluble compound, and the protective layer having an adhesion force of 0.5N / 10mm or more to the silicon wafer.

[0015] The manufacturing method of the electronic component device of the present invention includes a temporary protection step after protecting a substrate with a protective sheet on a protected surface, wherein the protective sheet comprises: a protective layer containing a water-soluble polymer compound, and a substrate layer overlapping one side of the protective layer, the protective layer having an adhesion force of 0.5 N / 10 mm or more to a silicon wafer, the temporary protection step comprising: a first step of attaching the protective layer of the protective sheet to the protected surface, and a second step of removing the protective sheet from the protected surface, the second step comprising: a step of peeling the substrate layer from the protective layer, and a step of removing the protective layer by dissolving at least a portion of the protective layer with an aqueous liquid. Attached Figure Description

[0016] Figure 1A This is a schematic cross-sectional view obtained by cutting an example of the protective sheet of this embodiment along the thickness direction.

[0017] Figure 1B This is a schematic cross-sectional view obtained by cutting another example of the protective sheet of this embodiment along the thickness direction.

[0018] Figure 1C This is a schematic cross-sectional view obtained by cutting another example of the protective sheet of this embodiment along the thickness direction.

[0019] Figure 2 This is a schematic cross-sectional view showing an example of a semiconductor wafer serving as a substrate.

[0020] Figure 3A This is a schematic cross-sectional view showing the situation after the substrate has been protected by a protective sheet, as exemplified by one.

[0021] Figure 3B This is a schematic cross-sectional view illustrating an example of peeling the substrate layer from the protective layer.

[0022] Figure 3C This is a schematic cross-sectional view illustrating an example of a protective layer being fragmented after the substrate layer has been removed.

[0023] Figure 3D This is a schematic cross-sectional view illustrating an example of a laminate of a protective layer and a substrate being miniaturized.

[0024] Figure 3E This is a schematic cross-sectional view illustrating an example of a protective layer piece being removed from a substrate.

[0025] Figure 3F This is a schematic cross-sectional view illustrating an example of a protective layer piece being removed from a substrate piece.

[0026] Figure 4A This is a schematic cross-sectional view showing the situation after the protective surface (circuit surface) of a semiconductor wafer has been protected by a protective sheet, as exemplified by this one.

[0027] Figure 4B This is a schematic cross-sectional view illustrating a grinding process performed while using a protective sheet.

[0028] Figure 4C This is a schematic cross-sectional view showing the situation after the first process (attachment process) is performed while using a protective sheet as an example.

[0029] Figure 4D This is a schematic cross-sectional view illustrating a scenario where a protective sheet is used while performing a peeling process in the second process (removal process).

[0030] Figure 4E This is a schematic cross-sectional view illustrating an example of a protective film with its protective layer segmented into smaller pieces.

[0031] Figure 4F This is a schematic cross-sectional view illustrating another example of how the protective layer of a protective sheet is made into smaller pieces.

[0032] Figure 4G This is a schematic cross-sectional view illustrating yet another example of a situation where the protective layer of a protective sheet is made into smaller pieces.

[0033] Figure 4H This is a schematic cross-sectional view showing the removal of the protective layer of the protective sheet through the dissolution process in the second process (removal process).

[0034] Figure 4I This is a schematic cross-sectional view illustrating a modified example of removing the protective layer of the protective sheet through a dissolution process in the second process (removal process). Detailed Implementation

[0035] Hereinafter, various embodiments of the manufacturing method of the protective sheet and electronic component device of the present invention will be described in turn with reference to the accompanying drawings.

[0036] It should be noted that the diagram in the attached image is for illustrative purposes only and may not be the same as the aspect ratio of the actual object.

[0037] like Figures 1A to 1C As shown, the protective sheet 1 of this embodiment at least includes a protective layer 12 comprising a water-soluble polymer compound. For example, such as Figure 1A and Figure 1B As shown, the protective sheet 1 of this embodiment may further include a substrate layer 11 overlapping one side of the protective layer 12. For example, as Figure 1AAs shown, the substrate layer 11 may have an adhesive layer 11b overlapping one side of the protective layer 12, and a support layer 11a overlapping the adhesive layer 11b. On the other hand, for example, as... Figure 1B As shown, the substrate layer 11 may only have a support layer 11a. It should be noted that, for example, as... Figure 1C As shown, the protective sheet 1 of this embodiment may have two release linings 15 that are respectively overlapped on both sides of the protective layer 12.

[0038] The protective sheet 1 in this embodiment is used, for example, to be adhered to one side of the substrate to be protected (hereinafter also referred to as the protected surface). Specifically, the protective layer 12 can be adhered to the protected surface. The protective layer 12 can be used as a pressure-sensitive sheet adhesive that can be bonded to the protected surface by being pressed against it.

[0039] The protective sheet 1 is used, for example, to temporarily protect the protective surface of the substrate to which the substrate is to be bonded. Examples of substrates to which the substrate is to be bonded include glass substrates, silicon wafers, stainless steel (SUS) substrates, organic material substrates, or ceramic substrates.

[0040] Specifically, examples of substrates used as adhered objects include semiconductor wafers used to obtain semiconductor chips, semiconductor chips formed by miniaturizing semiconductor wafers, interconnecting circuit boards composed of multiple interconnecting circuit boards, and circuit boards. The surfaces of these substrates that are protected typically have uneven surfaces.

[0041] The semiconductor wafer W, serving as the substrate S, is, for example, Figure 2 It is constructed as shown. Figure 2 The semiconductor wafer W shown includes a semiconductor wafer body W1 and a plurality of electrode portions W2 disposed on one surface of the semiconductor wafer body W1. In the semiconductor wafer W, the surface on which the plurality of electrode portions W2 are disposed is called the circuit surface (circuit forming surface). Each electrode portion W2 has a plurality of bump electrodes, and adjacent bump electrodes are arranged with a narrow spacing. In other words, the plurality of bump electrodes are arranged in a high density in each electrode portion W2. Since the plurality of bump electrodes are typically formed by plating one surface of the semiconductor wafer body W1, the plurality of electrode portions W2 are formed to protrude outward from one surface of the semiconductor wafer body W1. In this semiconductor wafer W, the surface on which the bump electrodes are disposed is called the protected surface.

[0042] Semiconductor wafer W, for example, along Figure 2 The cut line D shown is cut (divided) and then chipped into semiconductor chips. Figure 2 The diagram shows a cutting line D for obtaining a semiconductor chip having an electrode portion W2. The semiconductor chip will have at least one electrode portion W2.

[0043] The electrode portion W2 of the semiconductor chip is electrically connected to the electrode portions of other components. Examples of other components connected to the electrode portion W2 of the semiconductor chip include circuit boards or other semiconductor chips constructed in the same manner as the semiconductor chip described above.

[0044] For example, semiconductor chips sometimes have: paired electrode portions disposed on two sides of the semiconductor chip body, and conductive portions extending through the semiconductor chip body along the thickness direction to connect the paired electrode portions to each other. This type of semiconductor chip is called a through-silicon via (TSV). The electrode portions are electrically connected to other components. A TSV-type semiconductor chip can have only one side as a circuit surface, or both sides as circuit surfaces. In a TSV-type semiconductor chip, since electrode portions may be formed on both sides, both sides of the semiconductor chip can potentially be protected surfaces.

[0045] As semiconductor chips, examples include sensor chips that incorporate sensor elements (such as light-receiving elements and vibration elements). Examples of sensor chips include complementary metal-oxide-semiconductor (CMOS) chips.

[0046] For example, Figure 2 The semiconductor wafer W shown is sometimes used after a semiconductor chip is assembled on each of the multiple electrode sections W2, and then the semiconductor chips are individually resin-encapsulated. That is, Figure 2 The semiconductor wafer W shown is sometimes used as a substrate for wafer-level packaging (WLP). Wafer-level packaging (WLP) is classified as the aforementioned electronic component connector.

[0047] As a connector for the aforementioned electronic components, a dummy wafer may also be cited as an example. A dummy wafer, for example, includes a support substrate and a package formed by resin encapsulating multiple semiconductor chips disposed on one side of the support substrate. The dummy wafer may also simply be a package removed from the support substrate. A redistribution layer may be formed on at least one side of the dummy wafer. In this case, the protective layer 12 can be used to protect the redistribution layer. It should be noted that the partitions formed by dividing the dummy wafer to include at least one semiconductor chip may also be substrates.

[0048] The protective layer 12 has a tight fit to the surface of the substrate to be protected, which is the substrate to be adhered to. By attaching the protective layer 12 of the protective sheet 1 to the surface to be protected until the protective layer 12 overlapping the surface to be protected is removed, foreign matter can be prevented from adhering to the surface to be protected.

[0049] Furthermore, even if the surface of the object being protected has unevenness, the protective layer 12 can deform accordingly. Therefore, the protective layer 12 can fully penetrate the recess, thus exhibiting good embeddability.

[0050] Furthermore, for example, as described above, the protective sheet 1 can be easily removed using an aqueous liquid after it has been used to temporarily protect the surface of the object being protected.

[0051] It should be noted that the method of using the protective sheet 1, which is used to attach the protective layer 12 of the protective sheet 1 to the substrate that is being adhered to, will be described in detail later.

[0052] [The substrate layer of the protective film] As described above, the substrate layer 11 may consist solely of the support layer 11a, or it may be a laminate of the support layer 11a and the adhesive layer 11b.

[0053] The thickness of the substrate layer 11 is not particularly limited, for example, it is 1 μm or more and 300 μm or less. This thickness can be 3 μm or more, or 5 μm or more. Furthermore, this thickness can be 40 μm or less. It should be noted that when the substrate layer 11 is a laminate, the above thickness refers to the total thickness of the laminate.

[0054] (Support layer of substrate layer) The support layer 11a of the substrate layer 11 is, for example, made of a resin film. The support layer 11a may contain one type of resin or multiple types of resin. The support layer 11a preferably contains 95% by mass or more of resin, and more preferably 98% by mass or more of resin.

[0055] Resins containing polar groups can be listed as examples of resins included in the support layer 11a. By including a resin with polar groups in the support layer 11a, the wettability of the surface of the support layer 11a is improved. In other words, the surface free energy of the support layer 11a can be increased.

[0056] From the perspective of improving the adhesion between the support layer 11a and the adhesive layer 11b or the protective layer 12, the surface wettability of the support layer 11a is preferably higher.

[0057] Examples of resins with polar groups include polyester resins (PET, etc.), polyimide resins, and polyamide-imide resins. At least one of polyimide resin and polyester resin is preferred.

[0058] For example, the support layer 11a can be a polyimide resin film, a polyamide-imide resin film, or a polyester resin film.

[0059] The thickness of the support layer 11a can be, for example, more than 5 μm and less than 50 μm.

[0060] (Adhesive layer of substrate layer) The adhesive layer 11b, for example, has pressure-sensitive adhesive properties. The adhesive layer 11b, for example, contains at least an acrylic resin. The acrylic resin will be described in detail later.

[0061] The adhesive layer 11b may have a substantially non-reactive composition. Such an adhesive layer 11b may, for example, comprise an acrylic resin and an isocyanate compound. In this case, the acrylic resin may not have (meth)acrylate structural units containing polymerizable groups in its molecule (described in detail below).

[0062] On the other hand, the adhesive layer 11b can also be configured such that the curing reaction is advanced by irradiation with active energy rays (such as ultraviolet rays), thereby reducing the adhesive strength. Such an adhesive layer 11b may, for example, contain acrylic resin, isocyanate compound, and polymerization initiator (such as photopolymerization initiator).

[0063] The aforementioned acrylic resins, for example, have at least one (meth)acrylate alkyl ester structural unit, a hydroxyl-containing (meth)acrylate structural unit, and a (meth)acrylate structural unit containing a polymerizable group in their molecules. The structural unit is the unit that constitutes the main chain of the acrylic resin.

[0064] The aforementioned alkyl methacrylate structural unit originates from the alkyl methacrylate monomer. In other words, the molecular structure of the alkyl methacrylate monomer after polymerization is the alkyl methacrylate structural unit. The term "alkyl" indicates the hydrocarbon portion that forms an ester bond with (meth)acrylic acid. The alkyl portion can have 6 or more but less than 12 carbon atoms.

[0065] Examples of alkyl methacrylate structural units include methyl methacrylate, ethyl methacrylate, propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, tert-butyl methacrylate, pentyl methacrylate, isoamyl methacrylate, hexyl methacrylate, heptyl methacrylate, 2-ethylhexyl methacrylate, octyl methacrylate, isooctyl methacrylate, nonyl methacrylate, isononyl methacrylate, decyl methacrylate, isodecyl methacrylate, undecyl methacrylate, dodecyl methacrylate, tridecyl methacrylate, tetradecyl methacrylate, pentadecyl methacrylate, hexadecyl methacrylate, heptadecanyl methacrylate, octadecyl methacrylate, nonadecanyl methacrylate, or eicosyl methacrylate.

[0066] The aforementioned acrylic resin has a hydroxyl-containing (meth)acrylate structural unit, the hydroxyl group of which readily reacts with the isocyanate group.

[0067] By pre-coexisting acrylic resin with hydroxyl-containing (meth)acrylate structural units and isocyanate compounds in adhesive layer 11b, adhesive layer 11b can be moderately cured. Therefore, adhesive layer 11b can be sufficiently gelled. Thus, adhesive layer 11b can maintain its shape while exhibiting adhesive properties.

[0068] The hydroxyl-containing (meth)acrylate structural unit is preferably a hydroxyl-containing (meth)acrylate C2-C4 alkyl ester structural unit. The designation "C2-C4 alkyl" indicates the hydrocarbon moiety that forms an ester bond with (meth)acrylate and its number of carbon atoms. In other words, a hydroxyl-containing (meth)acrylate C2-C4 alkyl ester monomer represents a monomer in which (meth)acrylate forms an ester bond with an alcohol (usually a diol) having 2 or more but fewer than 4 carbon atoms. It should be noted that the C2-C4 alkyl hydrocarbon moiety is usually a saturated hydrocarbon.

[0069] Examples of hydroxyl-containing (meth)acrylate C2-C4 alkyl ester structural units include hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxy-n-butyl (meth)acrylate, and hydroxyisobutyl (meth)acrylate.

[0070] The aforementioned acrylic resin comprises (meth)acrylate structural units containing polymerizable unsaturated double bonds in the side chains.

[0071] The aforementioned acrylic resin, containing (meth)acrylate structural units with polymerizable groups, can generate free radicals from a photopolymerization initiator upon irradiation by active energy rays such as ultraviolet light, and these free radicals can cause cross-linking reactions between the acrylic resins. Therefore, irradiation can reduce the adhesive strength of the adhesive layer 11b.

[0072] It should be noted that, as active energy rays, ultraviolet rays, radiation, and electron beams can be used.

[0073] Specifically, the (meth)acrylate structural unit containing polymerizable groups can have a molecular structure in which the hydroxyl group in the aforementioned (meth)acrylate structural unit contains an isocyanate group and the isocyanate group of the (meth)acrylate monomer forms a carbamate bond.

[0074] Polymerizable (meth)acrylate structural units containing polymerizable groups can be prepared after the polymerization reaction of the acrylic resin. For example, after copolymerization of alkyl (meth)acrylate monomers and hydroxyl-containing (meth)acrylate monomers, a portion of the hydroxyl-containing (meth)acrylate structural unit can undergo a carbamate reaction with the isocyanate group of an isocyanate-containing polymerizable monomer to obtain the aforementioned polymerizable (meth)acrylate structural unit containing polymerizable groups.

[0075] The aforementioned isocyanate-containing (meth)acrylate monomers preferably have one isocyanate group and one (meth)acryloyl group in the molecule. Examples of such monomers include, for instance, ethyl 2-isocyanate (meth)acrylate.

[0076] The adhesive layer 11b may also contain an isocyanate compound. A portion of the isocyanate compound may be in a state resulting from reactions such as urethane esterification.

[0077] The isocyanate compound has multiple isocyanate groups in its molecule. Because the isocyanate compound has multiple isocyanate groups in its molecule, the cross-linking reaction between the aforementioned acrylic resins in the adhesive layer 11b can proceed.

[0078] Examples of isocyanate compounds include aliphatic diisocyanates, alicyclic diisocyanates, and aromatic diisocyanates. Furthermore, examples of isocyanate compounds include polymeric polyisocyanates such as diisocyanate dimers and trimers, or polymethylene polyphenyl polyisocyanates. The aforementioned isocyanate compounds can be used alone or in combination of two or more.

[0079] The polymerization initiator that may be included in the adhesive layer 11b is a compound capable of initiating a polymerization reaction by applying heat or light energy. By including a polymerization initiator in the adhesive layer 11b, when heat or light energy is applied to the adhesive layer 11b, a cross-linking reaction between the acrylic resins can occur, thereby enabling the adhesive layer 11b to cure. As a result, the adhesive strength of the adhesive layer 11b can be reduced, making it easier for peeling to occur between the protective layer 12 and the cured adhesive layer 11b.

[0080] As a polymerization initiator, commercially available general photopolymerization initiators or thermal polymerization initiators can be used.

[0081] The adhesive layer 11b may also contain additives. Examples of additives include antioxidants, UV absorbers, or surfactants.

[0082] The thickness of the adhesive layer 11b can be, for example, more than 5 μm and less than 150 μm.

[0083] [Protective layer of the protective film] The protective layer 12 may contain, for example, a water-soluble polymer compound. The water-soluble polymer compound has a hydrophilic group in its molecule. The protective layer 12 preferably contains 90% by mass or more of the water-soluble polymer compound, more preferably 95% by mass or more, and even more preferably 99% by mass or more. Therefore, the protective layer 12 can be more easily removed using an aqueous liquid.

[0084] The protective layer 12 may contain, for example, a first water-soluble compound and a second water-soluble compound as water-soluble polymers. The first water-soluble compound is preferably a compound having a polyoxyethylene structure in its molecule. The second water-soluble compound is preferably a water-soluble polyester resin with a mass-average molecular weight of 2000 or more.

[0085] Both the first and second water-soluble polymer compounds are water-soluble and will completely dissolve when a film (less than 50 μm thick) of each water-soluble polymer compound is immersed in water at 40°C.

[0086] The protective layer 12 has a hydrophilicity of a specified degree or higher. When the protective layer 12 has a hydrophilicity of a specified degree or higher, at least a portion of the protective layer 12 will typically dissolve in the aqueous liquid. The protective layer 12 is configured such that, due to its hydrophilicity of a specified degree or higher, at least a portion of it will dissolve upon contact with the aqueous liquid, thereby being removed from the surface of the substrate.

[0087] The adhesion force of the protective layer 12 to the silicon wafer is 0.5 [N / 10mm] or more. This adhesion force is preferably 2.0 [N / 10mm] or more, more preferably 3.0 [N / 10mm] or more, and particularly preferably 5.0 [N / 10mm] or more. Because the protective layer 12 has a greater adhesion force to the silicon wafer, it is possible to further suppress the protective layer 12 from being peeled off along with the substrate layer 11 when the substrate layer 11 or the like layer superimposed on it is peeled off from the protective layer 12. Furthermore, it is possible to further suppress the unintended exposure of the protected silicon wafer surface.

[0088] The adhesion force of the protective layer 12 to the silicon wafer can be less than 10.0 [N / 10mm].

[0089] For example, increasing the molecular weight of the water-soluble polymer contained in the protective layer 12 can increase the aforementioned adhesion force. On the other hand, decreasing the molecular weight of the water-soluble polymer contained in the protective layer 12 can decrease the aforementioned adhesion force.

[0090] The adhesion of the protective layer 12 to the silicon wafer (bare silicon wafer) was measured under the following conditions. Although with... Figure 1CThe protective sheet 1 shown is illustrated as a specific example, but even if it has... Figure 1A or Figure 1B The protective sheet 1 shown was also tested for the above-mentioned sealing force in the same manner.

[0091] First, one of the two peel-off liners 15 is peeled off from the protective layer 12, exposing one side of the protective layer 12. Backing tape is then applied to this exposed side to obtain the first test specimen. The application of the backing tape is performed using a manual roller at a temperature of 25°C.

[0092] Next, after cutting the first test piece to a width of 100 mm, another release liner was peeled off from the protective layer 12, exposing the other side of the protective layer 12. This exposed side was then bonded to the bare wafer to obtain the second test piece (sample for testing). The bonding to the bare wafer was performed using a 2 kg standard roller (manual bonding test roller adhesive tape bonding test machine) at a temperature of 90°C and a speed of 10 mm / second. After bonding, the wafer was allowed to cool naturally for at least 20 minutes.

[0093] Next, under conditions of 23°C, a peel angle of 180°, and a peel speed of 300 mm / min, the protective layer 12 and the backing tape were peeled from the bare wafer, and the peel force of the sample was measured. The measured peel force was then used as the aforementioned adhesion force. For example, an Autograph (manufactured by SHIMADZU) can be used as the measuring device.

[0094] The energy storage modulus of the protective layer 12 at 70°C is preferably 100,000 Pa or less, more preferably 50,000 Pa or less. With the energy storage modulus of the protective layer 12 at 70°C being 100,000 Pa or less, sufficient embeddability can be achieved even when the temperature is low when the protective layer 12 is attached to the surface of the object being protected.

[0095] It should be noted that the energy storage modulus of the protective layer 12 at 70°C can be above 10,000 Pa.

[0096] For example, by increasing the molecular weight of the water-soluble polymer contained in the protective layer 12, the aforementioned storage modulus can be increased. On the other hand, for example, by decreasing the molecular weight of the water-soluble polymer contained in the protective layer 12, the aforementioned storage modulus can be decreased.

[0097] The storage modulus (shear storage modulus) of the protective layer 12 was determined as follows. Specifically, in the determination of the storage viscoelasticity of the protective layer 12, the protective layer was laminated as needed to prepare a sheet-like test sample with a thickness of 250 μm or more and 350 μm or less. The test sample was cut into a test piece using a punch with a diameter of 8 mm. Then, the measurement was performed under the following test conditions, and the measured value (G') [Pa] of the storage modulus at 70°C was read.

[0098] Measuring apparatus: rheometer.

[0099] (For example, HAAKE Corporation manufactures "MARS III").

[0100] Temperature measurement: Increase the temperature from 40℃ to 100℃ (heating rate 10℃ / minute).

[0101] Measurement frequency: 1 Hz (1 / second).

[0102] Strain: 5%.

[0103] Measurement gap: 0.250 mm.

[0104] Measurement mode: Shear mode.

[0105] Measurement terminal: The measurement surface is a parallel plate with a diameter of 8mm.

[0106] In the aforementioned protective sheet 1, the thickness of the protective layer 12 is not particularly limited, for example, it is 1 μm or more and 100 μm or less. This thickness can be 3 μm or more, or 5 μm or more. Furthermore, this thickness can be 40 μm or less. It should be noted that when the protective layer 12 is a laminate, the above thickness refers to the total thickness of the laminate.

[0107] The first type of water-soluble compound is, for example, a compound having a polyoxyethylene structure in its molecule. The polyoxyethylene structure functions as a hydrophilic group. Because the first type of water-soluble compound has a polyoxyethylene structure in its molecule as a hydrophilic group, it can dissolve more readily in aqueous liquids, even at room temperature.

[0108] Examples of first water-soluble compounds include polyethylene glycol (PEG) (e.g., molecular weight less than 20,000) which has only a polyoxyethylene structure in its molecule, polyethylene oxide (PEO) (e.g., molecular weight greater than 20,000) which has only a polyoxyethylene structure in its molecule, and polyoxyalkylene copolymers (e.g., molecular weight greater than 50,000) which have both a polyoxyethylene structure and a polyoxypropylene structure in their molecule.

[0109] Polyoxyalkylene copolymers can be block copolymers with blocks having a polyoxyethylene structure and a polyoxypropylene structure in the molecule, or they can be random copolymers of ethylene oxide and propylene oxide.

[0110] The mass-average molecular weight (Mw) and average degree of polymerization of the first water-soluble compound exemplified above can be determined using aqueous gel permeation chromatography (Aqueous GPC). Details of the determination conditions are as follows.

[0111] <Measurement Conditions> • Analysis device: Agilent 1260 Infinity.

[0112] • Chromatographic columns: TSKgel G6000PWXL and TSKgel G3000PWXL (manufactured by Tosoh Corporation).

[0113] The two chromatographic columns mentioned above are connected in series.

[0114] • Column temperature: 40℃.

[0115] • Eluent: 0.2M sodium nitrate aqueous solution.

[0116] • Injection volume: 100 μL.

[0117] • Detector: Differential refractive index detector (RI).

[0118] • Standard sample: PEG standard sample.

[0119] The mass-average molecular weight (Mw) of the tested sample (PEG, PEO, etc.) was calculated by using GPC determination of PEG standard samples.

[0120] The aforementioned water-soluble polymer compound, by having a polyoxypropylene structure in addition to a polyoxyethylene structure in its molecule, can further improve the adhesion of the protective layer 12 to the protected surface. Furthermore, it can further improve the heat resistance of the protective layer 12.

[0121] The mass-average molecular weight (Mw) of the aforementioned polyethylene oxide (PEO) is preferably 200,000 (200,000) or less. With a mass-average molecular weight (Mw) of 200,000 or less, the first water-soluble compound can have a sufficiently low softening point. Therefore, the protective layer 12 can adhere better to the surface being protected. Furthermore, the protective layer 12 can be efficiently removed from the surface being protected using an aqueous liquid in a shorter time. It should be noted that the mass-average molecular weight (Mw) can, for example, be 50,000 or more.

[0122] For the aforementioned polyethylene glycol (PEG), polyethylene oxide (PEO), or polyepoxide copolymers, which are the first water-soluble compounds, commercially available products can be used.

[0123] The second water-soluble compound is, for example, a water-soluble polyester resin. A water-soluble polyester resin is a dehydration condensation product of at least a polycarboxylic acid (e.g., terephthalic acid) and a polyol. Water-soluble polyester resins may contain sulfonyl (-SO3H) or carboxyl (-COOH) groups in their molecules. These groups may also be in a salt state.

[0124] Water-soluble polyester resins are water-soluble because they possess the following physical properties. Specifically, water-soluble polyester resins have at least one of the following physical properties (A) to (D).

[0125] (A) When water at room temperature (23±2℃) is sprayed in a mist at a spray pressure of 0.005MPa for 20 minutes over the entire surface of a 20μm thick film formed from water-soluble polyester resin, the film completely dissolves in the water.

[0126] (B) When water at 50°C is sprayed in a mist at a spray pressure of 0.005 MPa for 10 minutes over the entire surface of a 20 μm thick film formed from water-soluble polyester resin, the film completely dissolves in the water.

[0127] (C) When water-soluble polyester resin powder is mixed with water at room temperature in a mass ratio of powder:water = 1:5 to obtain a mixture, and the mixture is irradiated with ultrasound for 20 minutes, the water-soluble polyester resin powder is completely dissolved in the water.

[0128] (D) When water-soluble polyester resin powder is mixed with water at 50°C at a mass ratio of powder:water = 1:5 to obtain a mixture, and the mixture is irradiated with ultrasound for 10 minutes, the water-soluble polyester resin powder is completely dissolved in the water.

[0129] The mass-average molecular weight (Mw) of water-soluble polyester resin can be above 5000, above 7000, or above 10000.

[0130] Furthermore, the weight-average molecular weight (Mw) of the water-soluble polyester resin is preferably 40,000 or less, more preferably 30,000 or less, even more preferably 20,000 or less, and particularly preferably 15,000 or less. With a weight-average molecular weight (Mw) of 40,000 or less, the protective layer 12 is easily formed into a film, resulting in better embeddability. Furthermore, the protective layer 12 more effectively suppresses the adhesion of fine foreign matter to the protected surface. Additionally, the protective layer 12 is more easily removed using an aqueous liquid.

[0131] Water-soluble polyester resins can be resins that display acid values. The acid value of a water-soluble polyester resin can be below 10 mg KOH / g. The acid value of a water-soluble polyester resin is determined according to the neutralization titration method specified in JIS K0070:1992.

[0132] For water-soluble polyester resins that are used as the second water-soluble compound, commercially available products can be used.

[0133] In addition to the aforementioned compounding components, the protective layer 12 of this embodiment may further include, for example, surfactants, plasticizers, etc.

[0134] The protective layer 12 has a tight fit to the protected surface of the substrate. Furthermore, when the substrate layer 11 only has a support layer 11a, the protective layer 12 has a tight fit to the support layer 11a. It should be noted that when the substrate layer 11 has a support layer 11a and an adhesive layer 11b, since the protective layer 12 is in contact with the adhesive layer 11b, the protective layer 12 also has a tight fit to the adhesive layer 11b.

[0135] It should be noted that, for example, such as Figure 1B As shown, the protective sheet 1 of this embodiment may include a release liner 15. In the state before the protective sheet 1 is used, the release liner 15 covers one side of the protective layer 12 (the side of the protective layer 12 that does not overlap with the substrate layer 11). The release liner 15 is used to protect the protective layer 12 and is peeled off before the protective layer 12 is to be attached to, for example, a substrate.

[0136] The protective sheet 1 of this embodiment can be manufactured, for example, by conventional methods in the following manner.

[0137] First, the water-soluble polymer compound is dissolved in an aqueous solvent. Heating may be used during dissolution. Besides water, organic solvents can also be used as solvents. Preferably, an aqueous organic solvent is dissolved in water in any proportion. Examples of such aqueous organic solvents include methanol, ethanol, and isopropanol.

[0138] Next, the polymer solution prepared as described above is coated onto the substrate layer 11 or the release liner 15. After coating, a protective layer 12 is formed by heating at a temperature at which the solvent evaporates.

[0139] This is how protective sheet 1 can be manufactured, but the method of manufacturing protective sheet is not limited to the method exemplified above.

[0140] The protective sheet 1 is used, for example, as an auxiliary tool in the manufacture of electronic components. The protective sheet 1 is used temporarily, for example, during the manufacturing process of the electronic components. Therefore, the manufactured electronic components do not have the protective sheet 1.

[0141] In the case of electronic components, these can be, for example, semiconductor devices such as semiconductor integrated circuits with semiconductor chips, devices with system LSIs using complementary metal-oxide-semiconductor (CMOS), or devices that integrate mechanical components, sensors, actuators, or electronic circuits onto a silicon substrate, glass substrate, or organic material substrate using microfabrication techniques (MEMS: Micro Electro Mechanical Systems). It should be noted that the manufactured electronic components can also be devices with circuit boards.

[0142] Various substrates can be listed as substrates to which the protective layer 12 of the protective sheet 1 of this embodiment is attached. As mentioned above, examples of substrates include semiconductor wafers, circuit boards, or interconnecting circuit boards (such as dummy wafers) formed by connecting multiple circuit boards.

[0143] Next, the manufacturing method of the electronic component device of this embodiment will be described.

[0144] The method for manufacturing an electronic component device according to this embodiment includes a temporary protection step of removing a protective sheet after protecting a substrate with a protective sheet. The protective sheet comprises a protective layer containing a water-soluble polymer compound and a substrate layer overlapping one side of the protective layer. The protective layer has an adhesion force of 0.5 N / 10 mm or more to the silicon wafer. The temporary protection step includes a first step of attaching the protective layer of the protective sheet to the protected surface (hereinafter also referred to as an attachment step) and a second step of removing the protective sheet from the protected surface (hereinafter also referred to as a removal step). The second step (removal step) includes a step of peeling the substrate layer from the protective layer (hereinafter also referred to as a peeling step) and a step of removing the protective layer by dissolving at least a portion of the protective layer with an aqueous liquid (hereinafter also referred to as a dissolution step).

[0145] In the aforementioned temporary protection process, an application process can be used, for example... Figure 3A As shown, a protective sheet 1 having a substrate layer 11 on one side of the protective layer 12 is used. The protective layer 12 of the protective sheet 1 is attached to the protected surface of the substrate S to protect the protected surface of the substrate S. Then, a peeling process is performed, for example, as shown in the figure. Figure 3B As shown, the substrate layer 11 is peeled off from the protective layer 12.

[0146] The manufacturing method of the electronic component device in this embodiment is as follows: Figure 3C and Figure 3D As shown, it may further include the process of dividing and miniaturizing at least the protective layer 12 to produce a plurality of protective layer pieces 12' (hereinafter also referred to as the miniaturization process).

[0147] In the miniaturization process, for example... Figure 3C As shown, multiple small pieces 12' can be fabricated by dividing and miniaturizing only the protective layer 12 in the laminate of the overlapping substrates S and protective layer 12. On the other hand, for example, as Figure 3D As shown, multiple stacked pieces formed by overlapping chip S' (made from miniaturized substrate S) and protective layer 12' can be produced by dividing and miniaturizing the stacked substrate S and protective layer 12.

[0148] In the aforementioned temporary protection process, a dissolution process is employed, for example... Figure 3E or Figure 3F As shown, each protective layer piece 12' overlapping the protected object surface (circuit surface of chip S', etc.) of the substrate S is removed using an aqueous liquid.

[0149] In the manufacturing method of the electronic component device according to this embodiment, at least one side of the substrate is protected by a protective layer 12. The protected side (the side to be protected) may be only one side of the substrate or both sides of the substrate. It should be noted that circuit components (described in detail below) may or may not be provided on the side to be protected.

[0150] The material of a substrate is not particularly limited as long as it is plate-shaped. Examples of substrate materials include glass, silicon, stainless steel (SUS), plastic, or ceramic. Examples of substrate materials include semiconductor wafers, CMOS or MEMS sensor wafers, pseudo-wafers, or circuit boards.

[0151] In the above-described bonding process, the protective layer 12 can be overlapped onto the surface of the substrate on the side where at least one of the circuit wiring, sensor portion, and electrode portion is disposed as a circuit component. For example, the protective layer 12 can be overlapped onto one side (circuit side) of the substrate where the circuit wiring is disposed, or onto one side of the substrate where the sensor portion is disposed, or onto one side of the substrate where the electrode portion is disposed. In the above-described bonding process, it is preferable to overlap the protective layer 12 onto at least one side of the substrate such that the protective layer 12 covers the circuit wiring, sensor portion, or electrode portion. Examples of circuit components include circuit wiring, electrode portion, transistor, diode, or sensor portion (such as a light sensor or vibration sensor).

[0152] The following is a detailed explanation of the case of manufacturing semiconductor devices (semiconductor integrated circuits) as electronic component devices.

[0153] Typically, the manufacturing process of a semiconductor device includes a front-end process of forming a circuit surface on one side of a bare wafer using highly integrated electronic circuits, and a back-end process of cutting chips from the semiconductor wafer with the circuit surface formed and assembling them.

[0154] In the preceding process, a circuit surface is formed on one side of a bare wafer to fabricate a semiconductor wafer W, which serves as a substrate. Circuit elements such as bumps, electrodes, cylindrical terminals, or semiconductor chips can be disposed on the circuit surface. Consequently, the side with the circuit surface formed has unevenness. In this embodiment, a semiconductor wafer W with a circuit surface formed on one side as a protected surface and having unevenness is used as the substrate. This semiconductor wafer W is further processed in subsequent processes.

[0155] In subsequent processes, at least the following processes are performed as temporary protection processes: an attachment process in which the protective layer 12 of the protective sheet 1 is attached to the protected object surface (circuit surface) of the semiconductor wafer W, which serves as the substrate, and a removal process in which the protective layer 12 attached to the protected object surface (circuit surface) is removed.

[0156] As needed, a grinding process can be performed between the above-mentioned attachment process and the removal process to reduce the thickness of the semiconductor wafer by grinding the semiconductor wafer in the state of having the protective sheet 1 attached.

[0157] In the removal process, a peeling process is performed to peel the substrate layer 11 from the protective layer 12 attached to the circuit surface of the semiconductor wafer W, and a dissolution process is performed to dissolve at least a portion of the protective layer 12 attached to the circuit surface of the semiconductor wafer W using an aqueous liquid.

[0158] As needed, laser grooving (described in detail below) or plasma cutting of semiconductor wafer W (described in detail below) can be performed between the above-mentioned stripping and dissolution processes.

[0159] It should be noted that during the dissolution process, the protective layer 12 can be fragmented into smaller pieces. In other words, during the dissolution process, the fragmented protective layer pieces 12' can be removed using an aqueous liquid.

[0160] The post-processing steps described above include, for example, the attachment step described above, the grinding step described above as needed, the fixing step of attaching the side of the semiconductor wafer opposite to the circuit surface to the adhesive fixing layer 22 of the dicing tape 20 to fix the semiconductor wafer, the peeling step in the removal step described above, the miniaturization step of at least the protective layer 12 as needed, the dissolving step in the removal step described above, and the removal step of peeling and removing the semiconductor wafer W or semiconductor chip from the adhesive fixing layer 22 of the dicing tape 20. Semiconductor integrated circuits (semiconductor devices) are manufactured, for example, through these processes.

[0161] In the manufacturing method of the semiconductor device (electronic component device) of this embodiment, at least the protective layer 12 of the protective sheet 1 and the cutting tape 20 (see reference) are used. Figure 4C The semiconductor device is manufactured as follows. The dicing tape 20, having a base layer 21 and the aforementioned adhesive fixing layer 22, is used as an auxiliary tool for manufacturing the semiconductor device. It should be noted that commercially available products can be used as the dicing tape 20.

[0162] In the bonding process, for example, Figure 4A As shown, the protective layer 12 of the protective sheet 1 is superimposed on the circuit surface of the semiconductor wafer W. In the bonding process, for example, the protective layer 12 is superimposed on the circuit surface by directly pressing and attaching it.

[0163] By overlaying the protective layer 12 onto the circuit surface of the semiconductor wafer W until the protective layer 12 is removed, the circuit surface can be protected by the protective layer 12. Therefore, it is possible to prevent dust and the like from adhering to the circuit surface of the semiconductor wafer W covered by the protective layer 12.

[0164] The above grinding process is performed as needed. For example, with the semiconductor wafer W, protective layer 12, and substrate layer 11 stacked, the surfaces of the semiconductor wafer W without any circuit components are ground. Specifically, as follows... Figure 4B As shown, grinding (backside grinding) is performed using a grinding pad K until the semiconductor wafer W reaches the specified thickness. Through the grinding process, the thickness of the semiconductor wafer W is reduced to the specified thickness.

[0165] In a fixed process, such as Figure 4C As shown, while the cutting ring R is assembled onto the adhesive fixing layer 22 of the cutting tape 20, the semiconductor wafer W is attached to and fixed onto the adhesive fixing layer 22 of the cutting tape 20.

[0166] It should be noted that, without performing the above-mentioned grinding process, the attachment process in the temporary protection process can be performed by overlapping the protective layer 12 onto the protected surface (circuit surface) of the semiconductor wafer W after attaching and fixing the semiconductor wafer W to the adhesive fixing layer 22 of the cutting tape 20.

[0167] In the stripping process of the removal process, for example, Figure 4D As shown, the substrate layer 11 is peeled off from the surface of the protective layer 12 before the protective layer 12 is removed from the surface of the semiconductor wafer W.

[0168] During the peeling process, the protective layer 12 can be irradiated with active energy rays such as ultraviolet light before peeling off the substrate layer 11. In this case, a protective layer 12 containing a photopolymerization initiator, as described above, is used.

[0169] Following the aforementioned stripping process, a miniaturization process is performed as needed to break down at least the protective layer 12 into smaller wafers. For example, sometimes the protective layer 12 and the semiconductor wafer are miniaturized into semiconductor chips (dies) through laser grooving or plasma dicing of the semiconductor wafer W.

[0170] In the miniaturization process, for example... Figure 4E or Figure 4F As shown, only the protective layer 12 is miniaturized, or the protective layer 12 and the semiconductor wafer W are miniaturized.

[0171] In laser grooving processes, for example... Figure 4E As shown, the circuit surface is protected by the protective layer 12 while being irradiated with laser L. For example, in the case where an insulating film with a relatively low dielectric constant (Low-k film) smaller than SiO2 exists on the circuit surface, laser grooving can be performed. The wiring layer containing the Low-k film is removed by laser, forming two fine grooves spaced apart within the dicing street. Then, the semiconductor wafer W can be miniaturized by subsequent plasma cutting.

[0172] During laser grooving, foreign matter such as fragments of the insulating film may be generated as the laser L irradiates the wafer. At this time, because the protected surface of the semiconductor wafer W is protected by the protective layer 12, the adhesion of foreign matter to the protected surface can be suppressed.

[0173] In plasma cutting processes, for example, Figure 4F As shown, a semiconductor wafer W is cut to a specified size to form a semiconductor chip. By creating two grooves as described above, plasma can be irradiated only between the two grooves. For example, plasma cutting can be performed using a plasma generator and conventional methods.

[0174] In the miniaturization process, for example... Figure 4G As shown, an expansion operation can be performed: with the semiconductor wafer W to which the protective layer 12 is attached fixed on the adhesive fixing layer 22 of the dicing tape 20, the dicing tape 20 is stretched along the surface direction to increase its surface area. This allows the laminate of the semiconductor wafer W and the protective layer 12 to be segmented and miniaturized, and the spacing between adjacent semiconductor chips X formed by miniaturization can be increased along the surface direction.

[0175] The semiconductor wafer W needs to be miniaturized through the aforementioned expansion operation. Therefore, the semiconductor wafer W, miniaturized as described above, is designed to be well-cut. For example, fragile areas for miniaturization into semiconductor chips X (dies) are formed inside the semiconductor wafer W. These fragile areas can be formed by irradiating the semiconductor wafer W with a laser or similar method using a commercially available stealth dicing device. The protective layer 12 also needs to be miniaturized through the aforementioned expansion operation, and is therefore also designed to be well-cut.

[0176] The details of the above expansion operation are as follows. For example, Figure 4G As shown, after the cutting ring R is assembled onto the adhesive fixing layer 22 of the cutting tape 20, the cutting ring R is fixed to the clamp H of the expansion device. By lifting the lifting member U of the expansion device from the underside of the cutting tape 20, the cutting tape 20 is stretched in a planar direction. Thus, the semiconductor wafer W and the protective layer 12 are miniaturized under specific temperature conditions. These temperature conditions are, for example, -20°C or higher and 0°C or lower. By lowering the lifting member U, the expansion state is released (this is the low-temperature expansion operation).

[0177] Furthermore, under higher temperature conditions (e.g., above 10°C and below 25°C), the cutting tape 20 is stretched to increase its surface area. This pulls adjacent semiconductor chips X apart along the surface direction of the cutting tape 20, further widening the slit (gap) (room temperature expansion operation).

[0178] By stretching the cutting tape 20 along its surface to increase its area, the semiconductor wafer W can be divided into smaller semiconductor chips X, using the aforementioned vulnerable areas inside the semiconductor wafer as boundaries. At this time, as the semiconductor wafer W is divided into smaller semiconductor chips X, the protective layer 12 is also divided and miniaturized.

[0179] In the dissolution step of the removal process, for example, Figure 4H or Figure 4I As shown, an aqueous liquid is brought into contact with multiple protective layer pieces 12', and at least a portion of each piece 12' is dissolved by the liquid, thereby removing each protective layer piece 12' from the surface (protected surface) of the semiconductor wafer W or semiconductor chip X.

[0180] By removing the protective layer pieces 12' in this way, multiple protective layer pieces 12' can be removed relatively easily. In addition, the amount of foreign matter adhering to the protected surface can be reduced relatively easily by using the liquid. Furthermore, the surface of the semiconductor wafer W (the protected surface) with the protective layer 12 overlapped, or the surface of each semiconductor chip X (the protected surface) with the protective layer pieces 12' overlapped, can also be cleaned by the liquid.

[0181] In the dissolution step of the removal process, at least a portion of the miniaturized protective layer (multiple protective layer pieces 12') is dissolved by the aforementioned liquid. Therefore, the adhesion between the protective layer pieces 12' and the semiconductor chip X weakens, making them easier to peel off. Thus, the multiple protective layer pieces 12' can be removed relatively easily.

[0182] There are no particular limitations on what constitutes an aqueous liquid, as long as it is a liquid substance containing water. The liquid may contain more than 30% by mass, more than 50% by mass, more than 70% by mass, more than 80% by mass, or more than 90% by mass of water.

[0183] The liquid described above may contain components dissolved 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, isopropanol, propanol, or butanol.

[0184] In the dissolution step of the removal process, the protective layer piece 12' can be immersed in the liquid being stirred to bring the liquid into contact with the protective layer piece 12'. Alternatively, liquid sprayed from a nozzle or the like can come into contact with the protective layer piece 12'. The temperature of the liquid is not particularly limited; for example, it can be set to 10°C or higher and 90°C or lower.

[0185] For example, in the dissolution step of the removal process, while the circular plate-shaped stage supporting the cutting tape 20 from below rotates circumferentially, the liquid is sprayed onto the semiconductor wafer W or the semiconductor chip X attached to the cutting tape 20. This removes the multiple protective layer pieces 12' respectively overlapping the semiconductor wafer W or the semiconductor chip X. The rotation speed of the stage can be, for example, 500 rpm or more and 4000 rpm or less, the liquid spray volume can be, for example, 0.05 L / min or more and 5.0 L / min or less, and the spraying time can be, for example, 5 seconds or more and 300 seconds or less.

[0186] According to the semiconductor device manufacturing method of the above embodiment, since the protective layer 12 is overlapped on the surface (circuit surface) of the semiconductor wafer W where circuit constituent elements are formed, the circuit surface can be protected until the protective layer 12 is removed. Even if foreign matter is attached to the circuit surface before the protective layer 12 is overlapped, the foreign matter can be removed when the protective layer piece 12' overlapped on the circuit surface is removed. Therefore, it is possible to suppress the adhesion of foreign matter to the circuit surface of the fabricated semiconductor chip X.

[0187] In the removal process, the semiconductor wafer W or semiconductor chip X is peeled off from the adhesive layer 22 of the dicing tape 20. During the removal process, the semiconductor wafer W or semiconductor chip X needs to be easily peeled off from the adhesive layer 22 of the dicing tape 20. The dicing tape 20 is designed to perform this function effectively.

[0188] For example, the cutting tape 20 is configured such that the adhesive fixing layer 22 is cured by irradiation with active energy rays (e.g., ultraviolet light), thereby reducing the adhesive strength of the adhesive fixing layer 22. By curing the adhesive fixing layer 22 after irradiation, the adhesive strength of the adhesive fixing layer 22 can be reduced, thus making it easier to peel the semiconductor wafer W or semiconductor chip X from the adhesive fixing layer 22 after irradiation. Cutting tapes 20 with such a configuration are commercially available.

[0189] The manufacturing methods of the protective sheet and electronic component device according to the embodiments of the present invention are as illustrated above, but the present invention is not limited to the manufacturing methods of the protective sheet or electronic component device illustrated above.

[0190] That is, without impairing the effects of the present invention, various methods used in the manufacturing methods of general protective sheets or electronic component devices can be employed.

[0191] The matters disclosed in this specification include the following. (1) A protective sheet having a protective layer on a protective surface to be adhered to a substrate, the protective layer comprising a water-soluble compound, the protective layer having an adhesion force to a silicon wafer of 0.5 N / 10 mm or more.

[0193] Regarding the protective sheet constructed as described above, the protective layer has good embedding properties, the protective layer adheres well to the protective surface of the substrate and has good peel resistance, and the protective layer can be easily removed using an aqueous liquid. (2) According to the protective sheet described in (1) above, the energy storage modulus of the protective layer at 70°C is less than 50000Pa. (3) According to the protective sheet described in (1) or (2) above, the protective layer comprises a first water-soluble compound and a second water-soluble compound as the water-soluble compound, wherein the first water-soluble compound is a compound having a polyoxyethylene structure in the molecule, and the second water-soluble compound is a water-soluble polyester resin with a mass-average molecular weight of 2000 or more. (4) A method for manufacturing an electronic component device includes a temporary protection step of removing a protective sheet after protecting a substrate with a protective sheet on a target side. The protective sheet comprises: a protective layer containing a water-soluble polymer compound, and a substrate layer overlapping one side of the protective layer. The protective layer has an adhesion force of 0.5 N / 10 mm or more to a silicon wafer. The temporary protection step includes: a first step of attaching the protective layer of the protective sheet to the target side, and a second step of removing the protective sheet from the target side. The second step includes: a step of peeling the substrate layer from the protective layer, and a step of removing the protective layer by dissolving at least a portion of the protective layer with an aqueous liquid.

[0197] In the manufacturing method of this electronic component device, since the above-mentioned protective sheet is used, the protective layer has good embedding properties, the protective layer attached to the protective object surface of the substrate has good peel resistance, and the protective sheet can be easily removed using an aqueous liquid.

[0198] Example Next, the invention will be described in more detail through experimental examples, but the invention is not limited thereto.

[0199] As described below, protective sheets (protective layers) for the embodiments and comparative examples were prepared.

[0200] [Examples 1-3, Comparative Examples 1-3] <Raw materials used to form the protective layer> (First water-soluble compound) ·P1-A Random copolymer of ethylene oxide and propylene oxide.

[0201] Product name: "ALKOX EP1010N" (manufactured by Meisei Chemical Industry Co., Ltd.)

[0202] Mass-average molecular weight: approximately 100,000.

[0203] ·P1-B Homopolymers of ethylene oxide.

[0204] Product name: "ALKOX R-150" (manufactured by Meisei Chemical Industry Co., Ltd.)

[0205] Mass-average molecular weight: approximately 100,000.

[0206] ·P1-C Polyethylene glycol (purchased reagent).

[0207] Average molecular weight: approximately 2000.

[0208] ·P1-D Polyethylene glycol (purchased reagent).

[0209] Average molecular weight: approximately 600.

[0210] (Second water-soluble compound) ·P2-A Water-soluble polyester resin.

[0211] The product name "PLASCOAT Z-221" (manufactured by Koyo Chemical Industry Co., Ltd.) contains a sulfonyl group in its molecule.

[0212] Mass-average molecular weight: approximately 14,000.

[0213] (Other water-soluble compounds) PVA Polyvinyl alcohol.

[0214] Product name: "JMR-3M" (manufactured by JAPAN VAM&POVAL Co., Ltd.)

[0215] Mass-average molecular weight: approximately 10,000.

[0216] (Production of protective film) Protective sheets were fabricated according to the compositions shown in Table 1. Specifically, aqueous solutions of each polymer were prepared according to the formulations shown in Table 1, with a total polymer concentration of 20% by mass. The aqueous solutions of each polymer were heated to 60°C during preparation. The aqueous solutions of each polymer were coated onto release liner a (PET film, 50 μm thick). Release liner a has a side treated with silicone release liner, and the aqueous solutions of the polymers were coated onto this side using an applicator. Next, a drying process was performed at 130°C for 2 minutes to form a protective layer with a thickness of 5 μm overlapping one side of release liner a. Then, release liner b (PET film, 25 μm thick) was overlapped on the exposed side of each protective layer. It should be noted that release liner b has a side treated with silicone release liner, and this side was attached to the protective layer. In this way, protective sheets with protective layers sandwiched between two release liners were fabricated.

[0217] (Shear storage modulus of the protective layer) The shear storage modulus of each protective layer was determined using the method described above. The results are shown in Table 1.

[0218] (The peeling force of the protective layer on the bare silicon wafer) Following the method described above, the peel force of each protective layer on the bare silicon wafer was measured. The results are shown in Table 1. <Embedded Evaluation> The embedding performance of each protective sheet in a semiconductor chip with multiple bump electrodes on one side (hereinafter referred to as a semiconductor chip with bump electrodes) was evaluated.

[0219] First, protective sheets for each embodiment and each comparative example were prepared, with the peeling liner attached only on one side.

[0220] Next, a semiconductor chip with bumped electrodes is fabricated as follows. Specifically, multiple regions (3mm × 3mm regions) with multiple bumped electrodes are formed on one side of the semiconductor wafer body. In these regions, the diameter of the bumped electrodes (bump diameter) is 45μm, the spacing between adjacent bumped electrodes (bump pitch) is 150μm, and the height from the surface of the semiconductor wafer body to the top of the bumped electrodes is 40μm. The semiconductor wafer is cut into planar dimensions of 5mm × 5mm, such that each semiconductor chip with bumped electrodes has one of the aforementioned regions.

[0221] Next, under a pressure (lamination pressure) of 0.4 MPa and a roller temperature of 60°C, the protective layer of each protective sheet is attached to one side of the semiconductor wafer body.

[0222] Then, the embedment was evaluated according to the following criteria by observation using a digital microscope. The results are shown in Table 1 below.

[0223] (Evaluation Criteria) Advantage: No optical interference was detected. That is, each bump electrode is fully embedded inside the protective layer.

[0224] Good: Slight optical interference was observed on the outer periphery of each bump electrode. That is, the top of each bump electrode is sufficiently embedded in the protective layer, but the outer periphery of each bump electrode is not sufficiently embedded in the protective layer.

[0225] Defect: Obvious gaps were found on the outer periphery of each bump electrode. That is, even the area near the top of each bump electrode was not sufficiently embedded into the protective layer.

[0226] As can be seen from the above evaluation results, the protective layer of the embodiment has good embedding properties into the substrate with an uneven surface.

[0227] It should be noted that, although not shown in the above results, the substrate layer can be peeled off from the protective layer attached to the bare silicon wafer during the removal process without the protective layer remaining. Furthermore, multiple miniaturized protective layers can be removed relatively easily using water.

[0228] By using the protective layer of the embodiments described above to manufacture semiconductor devices, it is possible to efficiently manufacture semiconductor devices, etc., that have semiconductor chips with almost no foreign matter attached.

[0229] Industrial availability The method for manufacturing the electronic component device of the present invention is suitable, for example, for manufacturing semiconductor devices having semiconductor integrated circuits, etc.

[0230] Explanation of reference numerals in the attached figures 1: Protective sheet; 11: Substrate layer; 11a: Support layer; 11b: Adhesive layer; 12: Protective layer; 12': Protective layer piece; 15: Release liner; 20: Cutting tape; 21: Base layer; 22: Adhesive fixing layer; W: Semiconductor wafer; X: Semiconductor chip.

Claims

1. A protective sheet having a protective layer on the surface to be protected and adhered to a substrate. The protective layer contains a water-soluble compound. The protective layer has an adhesion force of 0.5 N / 10 mm or more to the silicon wafer.

2. The protective sheet according to claim 1, wherein, The energy storage modulus of the protective layer at 70°C is below 50,000 Pa.

3. The protective sheet according to claim 1 or 2, wherein, The protective layer comprises a first water-soluble compound and a second water-soluble compound as the water-soluble compound. The first water-soluble compound is a compound having a polyoxyethylene structure in its molecule. The second water-soluble compound is a water-soluble polyester resin with a mass-average molecular weight of 2000 or higher.

4. A method for manufacturing an electronic component device, comprising a temporary protection step of removing the protective sheet after protecting the target surface of a substrate with a protective sheet. The protective sheet comprises: a protective layer containing a water-soluble polymer compound, and a substrate layer overlapping one side of the protective layer. The protective layer has an adhesion force of 0.5 N / 10 mm or more to the silicon wafer. The temporary protection procedure includes: The first step involves attaching the protective layer of the protective sheet to the surface of the object being protected, and the second step involves removing the protective sheet from the surface of the object being protected. The second process includes: a process of peeling the substrate layer from the protective layer, and a process of removing the protective layer by dissolving at least a portion of the protective layer using an aqueous liquid.

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