Electromagnetic wave shielding sheet, shielding processed wafer, semiconductor device, and method for manufacturing the same

Abstract

Provided is an electromagnetic wave shielding sheet that can be used to coat a wafer before singulation, has excellent coating properties, and has high reliability, a wafer that has been processed using the electromagnetic wave shielding sheet, a semiconductor device, and a method for manufacturing the semiconductor device. The present invention is an electromagnetic wave shielding sheet (3) for coating a semiconductor wafer before singulation, and the electromagnetic wave shielding sheet (3) has at least a shielding film (30) that contains a conductive filler (F) and a binder component, and the electromagnetic wave shielding sheet (3) has an elongation of 100% to 1500% at 100°C, and in a hardened sheet obtained by treating the electromagnetic wave shielding sheet (3) at 180°C for 2 hours, the Young's modulus at 100°C is 100 MPa to 1000 MPa.

Description

[0001] Cross-reference of related applications

[0002] This application is based on and claims priority to Japanese Patent Application No. 2024-164422, filed on September 20, 2024, the entire disclosure of which is incorporated herein by reference. Technical Field

[0003] This disclosure relates to an electromagnetic wave shielding sheet, a shielding wafer, and a semiconductor device and a method for manufacturing the same. Background Technology

[0004] To prevent malfunctions of semiconductor components integrated within electronic devices such as mobile terminals, it is necessary to employ techniques to shield against electromagnetic noise generated by the semiconductor components or from external sources.

[0005] International Patent Publication No. 2019 / 117259 discloses a method for manufacturing a mounting structure, comprising: a step of preparing a mounting member on which a plurality of second circuit members are mounted on a first circuit member; a step of forming a first hardened layer covering the mounting member; and a step of forming a functional layer such as a shielding layer on the first hardened layer by a vapor phase method and / or a plating method. Furthermore, Japanese Patent Application Publication No. 2016-092275 discloses a sealing material comprising a support substrate with electromagnetic wave shielding properties and a sealing material laminated on the support substrate, wherein the support substrate has electromagnetic wave shielding properties. Summary of the Invention

[0006] In response to the trend towards thinner and lighter electronic devices, semiconductor packaging also demands miniaturized, lightweight, and high-density mounting. Therefore, wafer-level chip-size package (WL-CSP) technology, which encapsulates semiconductor components formed on a wafer by forming external terminals or sealing resin before wafer monolithization without internal wiring based on bonding wires, has attracted considerable attention. If an electromagnetic wave shielding sheet could be provided that can cover both the entire wafer and the sides of the monolithized semiconductor device, it would offer significant advantages in terms of versatility, cost-effectiveness, and mass production capabilities.

[0007] This disclosure is made in view of the aforementioned background, and its purpose is to provide an electromagnetic wave shielding sheet that can be used to completely cover a semiconductor wafer before it is monolithized, has excellent coverage and high reliability, as well as a shielding wafer, semiconductor device and manufacturing method thereof formed using the electromagnetic wave shielding sheet.

[0008] Through repeated and in-depth research, the inventors discovered that the problems of this disclosure can be solved in the following forms, thereby completing this disclosure.

[0009] [1]: An electromagnetic wave shielding sheet for covering at least one main surface of a semiconductor wafer before monolithization, the semiconductor wafer before monolithization having half-cut grooves formed in a lattice shape and element forming regions divided by the half-cut grooves and arranged in a matrix shape.

[0010] The electromagnetic wave shielding sheet has at least a shielding film comprising an adhesive component and a conductive filler (F).

[0011] The elongation of the electromagnetic wave shielding sheet at 100°C is 100%–1500%.

[0012] The Young's modulus of the hardened sheet after being treated at 180°C for 2 hours is 100MPa to 1000MPa at 100°C.

[0013] [2]: According to the electromagnetic wave shielding sheet described in [1], the peeling rate of the shielding sheet sourced from the electromagnetic wave shielding sheet after being heat-pressed at 120°C and 5MPa for 3 minutes on the entire main surface of the bare silicon wafer and then treated at 180°C for 2 hours is less than 15% in the pressure cooker boiling test based on Japanese Industrial Standards (JIS) K5600-5-6.

[0014] [3]: The electromagnetic wave shielding sheet according to [1] or [2], wherein the adhesive component comprises a curable compound (C) with a weight average molecular weight of less than 5,000 and a high molecular weight resin (P) with a weight average molecular weight of more than 10,000.

[0015] [4]: The electromagnetic wave shielding sheet according to any one of [1] to [3], wherein the content of conductive filler (F) is 45% to 85% by mass.

[0016] [5]: An electromagnetic wave shielding sheet according to any one of [1] to [4], wherein the average specific surface area of ​​the conductive filler (F) is [m²]. 2 The product of [g] and the content [g] of conductive filler (F) relative to 100 parts by mass of the adhesive component is 50 [m]. 2 ~1200[m 2 ].

[0017] [6]: The electromagnetic wave shielding sheet according to any one of [1] to [5], wherein the curing compound (C) comprises an epoxy-containing compound (E) having a weight average molecular weight of 5,000 or less, the epoxy-containing compound (E) having an epoxy equivalent of 110 g / eq to 1000 g / eq, and comprising 10 to 80 parts by mass of the epoxy-containing compound (E) relative to 100 parts by mass of the high molecular weight resin (P).

[0018] [7]: An electromagnetic wave shielding sheet according to any one of [1] to [6], wherein a shielding layer is formed such that the entire main surface of a 12-inch silicon bare wafer with a lattice pattern formed at 4000 μm intervals in a half-cut groove of 200 μm width and 200 μm depth, the electromagnetic wave shielding sheet is hot-pressed at 120°C and 5MPa for 3 minutes and treated at 180°C for 2 hours, and the shielding layer from which the electromagnetic wave shielding sheet originates is covered with a shielding layer that has a resistance value of 5 mΩ to 300 mΩ between the shielding layers covering the protrusions located adjacent to the half-cut grooves.

[0019] [8]: A shielding wafer having a shielding layer formed of an electromagnetic wave shielding sheet according to any one of [1] to [7] on at least one main surface of a semiconductor wafer before monolithization.

[0020] [9]: A semiconductor device is formed by monolithization of a shielded processing wafer according to [8] in units of element forming regions.

[0021]

[10] : A method for manufacturing a semiconductor device, comprising: a step of forming a half-cut groove in a semiconductor wafer having element forming regions formed in a matrix shape along scribing lines before monolithization;

[0022] The process of placing an electromagnetic wave shielding sheet according to any one of [1] to [7] on top of the semiconductor wafer;

[0023] The process of hot-pressing the electromagnetic wave shielding sheet onto the semiconductor wafer;

[0024] The process of obtaining a shielding layer by heating and hardening the electromagnetic wave shielding sheet; and

[0025] The process of monolithization is carried out on a unit basis, with the component forming area as the unit.

[0026] According to this disclosure, the following excellent effects are achieved: an electromagnetic wave shielding sheet that can be used to completely cover a semiconductor wafer before monolithization, with excellent coverage and high reliability, as well as a shielding processing wafer, a semiconductor device, and a method for manufacturing the same, formed using the electromagnetic wave shielding sheet.

[0027] The above and other objects, features and advantages of this disclosure will be more fully understood from the detailed description and accompanying drawings given below. Attached Figure Description

[0028] Figure 1 This is a schematic illustration of an example of a chip used in an implementation method.

[0029] Figure 2 yes Figure 1 Sectional view of the II-II cut section.

[0030] Figure 3 yes Figure 2 A magnified view of a portion of the image.

[0031] Figure 4 This is a schematic cross-sectional view showing an example of a wafer that has undergone shielding processing in Modified Example 1.

[0032] Figure 5 This is a schematic cross-sectional view showing an example of a wafer that has undergone shielding processing in Modification Example 2.

[0033] Figure 6 This is a schematic cross-sectional view showing an example of a wafer that has undergone shielding processing, as shown in Modification 3.

[0034] Figure 7 This is a side view showing an example of an electromagnetic wave shielding sheet according to an embodiment.

[0035] Figure 8 This is a side view of an example of a modified electromagnetic wave shielding sheet.

[0036] Figure 9 This is a schematic cross-sectional view showing an example of the main parts of a semiconductor device according to an embodiment.

[0037] Figure 10 This is a schematic cross-sectional view showing an example of the main part of a modified semiconductor device.

[0038] Figure 11 This is a schematic diagram illustrating an example of the manufacturing process of a semiconductor device according to an embodiment.

[0039] Figure 12 This is a schematic diagram illustrating an example of the manufacturing process of a semiconductor device according to an embodiment.

[0040] Figure 13 This is a schematic diagram illustrating an example of the manufacturing process of a semiconductor device according to an embodiment.

[0041] Figure 14 This is a schematic diagram illustrating an example of the manufacturing process of a semiconductor device according to an embodiment.

[0042] Figure 15 This is a schematic diagram illustrating an example of the manufacturing process of a semiconductor device according to an embodiment.

[0043] Explanation of icon numbers

[0044] 1: Semiconductor components are formed into wafers.

[0045] 2: SC layer

[0046] 3: ES film / electromagnetic wave shielding film

[0047] 3a: ES film

[0048] 4: Electrode pads

[0049] 5: Surface protective film

[0050] 6: Electrode post

[0051] 7: Sealing resin

[0052] 11: Semi-cut groove

[0053] 12: Component Formation Area

[0054] 13: Groove

[0055] 14: Multilayer wiring structure section

[0056] 15a: First insulating film

[0057] 15b: Second insulating film

[0058] 15c: Third insulating film

[0059] 16: Wiring

[0060] 17: Underline

[0061] 20, 20a: Shielding layer

[0062] 21: Unshielded layer

[0063] 30: Shielding film

[0064] 31: Non-shielding film

[0065] 33: Buffer sheet

[0066] 33': Buffer layer

[0067] 34: Enhanced tablets

[0068] 40: Pressed substrate

[0069] 50: Vacuum adsorption stage

[0070] 101, 101b, 101c: Shielding processed wafers

[0071] 201: Semiconductor Devices

[0072] X, Y, Z: Axis / Direction Detailed Implementation

[0073] The present disclosure will now be described in detail. Furthermore, other embodiments are also included within the scope of this disclosure as long as they conform to its spirit. The numerical range defined by "~" in this specification includes the values ​​described before and after the numerical value. Unless otherwise specified, each component in this specification may be used independently, individually, or in combination with two or more. The numerical values ​​described in this specification refer to values ​​obtained by the methods described in the [Examples] and other sections described later.

[0074] 1. Shielding processed chips

[0075] The shielding wafer disclosed herein is a wafer having a shielding layer (hereinafter also referred to as an SC layer), which is formed by coating at least one main surface of a semiconductor wafer before monolithization with an electromagnetic shielding sheet (hereinafter also referred to as an ES sheet) disclosed herein. This ES sheet is a sheet used for integral coating of a semiconductor wafer (hereinafter also simply referred to as a wafer), and has at least a shielding film comprising an adhesive component and a conductive filler (F). In this specification, the conductive filler (F) (hereinafter also simply referred to as filler (F)) refers to a filler that reflects electromagnetic waves. The adhesive component is the matrix component forming the layer, and examples include resins, curable compounds that can be cross-linked through curing treatment, monomers, and oligomers.

[0076] The elongation at 100°C of this ES sheet is 100% to 1500%. Furthermore, in the hardened sheet after treating this ES sheet at 180°C for 2 hours, the Young's modulus at 100°C is 100 MPa to 1000 MPa. The hardened sheet described here is formed by hardening the sheet without bonding it to the substrate. Moreover, the condition of treating at 180°C for 2 hours is a hardening condition used to determine the characteristics of this ES sheet. That is, the hardening conditions used to coat this ES sheet onto a wafer to obtain a shielding layer are not limited to the condition of treating at 180°C for 2 hours. Furthermore, the elongation is calculated as "100 × (elongated length - original length) / (original length)".

[0077] The object to be coated in this ES wafer is the wafer before it undergoes the monolithization process. Specific examples include wafers with wafer-level chip-scale packages (WL-CSP) before monolithization, wafers with semiconductor elements before monolithization, wafers with multilayer wiring structures before monolithization, bare wafers, and wafers with a thermal oxide film obtained by high-temperature processing of bare wafers.

[0078] The surface to be coated on this ES wafer can be the device formation area of ​​the wafer or its back side, and can be either single-sided or double-sided coated. According to this ES wafer, an SC layer can be formed on the entire wafer before monolithization, resulting in excellent manufacturability. The ES wafer exhibits excellent conformability to uneven shapes, making it suitable for overall coating of wafers having half-cut grooves formed in a grid pattern and device formation areas divided and arranged in a matrix by the half-cut grooves. By performing overall coating that also includes the half-cut grooves, an SC layer can be easily formed on the side surface of the monolithized semiconductor device.

[0079] The area to be covered by this ES wafer can be the entire wafer surface or a portion of the wafer. For example, an example is where the ES wafer covers approximately 80% of the main surface area of ​​the wafer. Furthermore, a bare wafer is a wafer before further processing, and examples include semiconductor substrates such as single-crystal silicon, gallium arsenide, and indium phosphide. The wafer diameter or thickness is arbitrary. Examples of bare wafer diameters are 100mm, 150mm, 200mm, 300mm, and 450mm. Examples of bare wafer (semiconductor substrate) thicknesses are approximately 400μm to 1000μm.

[0080] Figure 1 The diagram shows an example of a shielding wafer according to this embodiment. Figure 2 China indicates Figure 1 Cross-sectional view of section II-II. (See diagram below.) Figure 2 As shown, the shielding wafer 101 forms a multilayer wiring structure 14 on the semiconductor device forming wafer 1, and an SC layer 2 is coated on both the semiconductor device forming wafer 1 and the multilayer wiring structure 14. By having the SC layer 2, electromagnetic waves generated by the semiconductor devices of the semiconductor device forming wafer 1 or the wiring of the multilayer wiring structure 14 can be shielded. Furthermore, electromagnetic waves from the outside can be shielded, preventing malfunctions of the semiconductor device. The thickness of the SC layer can be appropriately designed according to the application. The thickness of the SC layer is typically around 1 μm to 300 μm. The lower limit of the thickness is more preferably 3 μm, more preferably 5 μm, and more preferably 10 μm. The upper limit of the thickness is more preferably 150 μm, more preferably 100 μm, and more preferably 50 μm.

[0081] like Figure 1 , Figure 2 As shown, the shielding wafer 101 includes a semiconductor device forming wafer 1, half-cut grooves 11 formed in a grid pattern along the X-axis and Y-axis directions of the semiconductor device forming wafer 1, and device forming regions 12 divided and arranged in a matrix by the half-cut grooves 11, and an SC layer 2. The device forming regions 12 are regions that are chip-formed through a monolithic process described later. In the semiconductor device forming wafer 1, as... Figure 1As shown, a slot 13 serving as a crystal orientation indicator is provided at the end of the semiconductor element forming wafer 1.

[0082] The half-cut groove 11 is a groove formed from the upper surface of the multilayer wiring structure 14 to the midpoint of the thickness direction of the semiconductor substrate of the semiconductor device forming wafer 1, and is formed along the grid-like scribing lines 17 formed along the X and Y axes. The width of the half-cut groove 11 is, for example, 20 μm to 500 μm. The depth of the half-cut groove 11 from the upper surface of the semiconductor device forming wafer 1 is, for example, 40 μm to 600 μm. The half-cut groove 11 can be formed by known methods such as a rotary blade for mechanical cutting or laser grooving. The half-cut groove also includes a shape in which the groove does not reach the semiconductor device forming wafer 1, and is formed only in the multilayer wiring structure 14.

[0083] Multilayer wiring structure section 14, for example, Figure 3 As shown, a first insulating film 15a, a second insulating film 15b, and a third insulating film 15c are stacked sequentially, and multiple metal patterns such as wiring 16 are formed in each layer. A surface protective film (not shown) may also be further formed on the upper layer of the multilayer wiring structure 14.

[0084] As described below, this SC layer may comprise a single layer or multiple layers, and at least has a shielding layer. Figure 2 The SC layer 2 shown includes a shielding layer 20. The shielding layer is a layer formed by curing a shielding film containing adhesive components and conductive filler (F). The shielding layer 20 can be a single layer or multiple layers. Additionally, as... Figure 4 As shown, the SC layer can also be a stack of shielding layer 20a and unshielded layer 21. Figure 4 As shown in the example, the unshielded layer 21 can be disposed on the side of the multilayer wiring structure 14 or on the opposite side. Examples of unshielded layers 21 include light-shielding layers, hard coatings, insulating layers, thermally conductive layers, and protective layers. In addition to being a single layer, the unshielded layer 21 can also be a multilayer of the same or different types.

[0085] The shielded wafer can be a wafer with a wafer-level chip-scale package (WL-CSP). Figure 5 The figure shows a schematic cross-sectional view of an example of a shielded wafer of a WL-CSP before monolithization. As shown in the figure, the shielded wafer 101b has electrode pads 4, a surface protective film 5, electrode pillars 6, sealing resin 7, and an SC layer 2 on the upper surface of the semiconductor device forming wafer 1. By monolithizing the shielded wafer 101b, a semiconductor device with its sides covered by the SC layer 2 can be obtained. The obtained semiconductor device is mounted on a printed circuit board (not shown) via solder balls (not shown) provided on the electrode pillars 6.

[0086] Figure 6The diagram shows a schematic cross-sectional view of another example of a shielded wafer with a WL-CSP. The shielded wafer 101c has a multilayer wiring structure 14 on the upper surface of the semiconductor device forming wafer 1, which is sealed with a sealing resin 7. Furthermore, the semiconductor device forming wafer 1 and the sealing resin 7 are covered by an SC layer 2. By monolithically processing the shielded wafer 101c, a semiconductor device with its upper surface and sides covered by an SC layer 2 can be obtained. Figure 9 wait).

[0087] 2. Electromagnetic wave shielding sheet

[0088] Figure 7 The figure shows a schematic side view of an example of the ES sheet of this embodiment. The ES sheet 3 shown in this figure includes a shielding film 30. The shielding film 30 can be a single layer or multiple layers. Figure 8 As shown, the ES sheet can also be configured as an ES sheet 3a formed by stacking one or more shielding films 30 and one or more non-shielding films 31. The shielding film 30 forms the shielding layer 20. The non-shielding film 31 forms the non-shielding layer 21. Examples of non-shielding films 31 include insulating films, thermally conductive films, light-shielding films, and hard-coated films. When the ES sheet has a non-shielding film, from the viewpoint of fully utilizing the shielding effect, it is preferable to sufficiently ensure the thickness of the shielding film. From this viewpoint, it is preferable that 50% to 90% of the thickness of the ES sheet is the shielding film, more preferably 55% to 80%.

[0089] The elongation at 100°C of this ES wafer is set to 100% to 1500%. Furthermore, in the hardened wafer after treating this ES wafer at 180°C for 2 hours, the Young's modulus at 100°C is set to 100 MPa to 1000 MPa. Based on this ES wafer assembly, the conformability to uneven shapes during the pressing of the overall coated ES wafer can be improved. In addition, wafer cracking and warping of the hardened wafer can be suppressed. Furthermore, peeling of the SC layer from the substrate can be suppressed, and tearing within recesses such as half-cut grooves can be effectively suppressed.

[0090] The lower limit of the elongation is more preferably 150%, and even more preferably 200%. Furthermore, the upper limit of the elongation is more preferably 1200%, and even more preferably 1000%. The lower limit of the Young's modulus is preferably 150 MPa, more preferably 200 MPa, and even more preferably 300 MPa. The upper limit of the Young's modulus is preferably 800 MPa, and even more preferably 600 MPa. When the ES sheet comprises a laminate of multiple films, it is not necessary for each film to meet the above conditions; it is sufficient that the elongation and Young's modulus are satisfied within the ES sheet itself.

[0091] The thickness of this ES sheet can be appropriately designed according to the application. The thickness of this ES sheet is typically around 2μm to 500μm. The lower limit of the thickness is more preferably 5μm, more preferably 8μm, and more preferably 12μm. The upper limit of the thickness is more preferably 300μm, more preferably 200μm, and more preferably 100μm. This ES sheet is suitable for applications such as... Figure 2 The coating layer shown follows the shape of the concave and convex surfaces, but it can also be applied to the embedding layer of this ES sheet when it is embedded (filled) in the concave areas.

[0092] From the viewpoint of improving reliability, the peeling rate in the electromagnetic wave shielding layer derived from the electromagnetic wave shielding sheet is preferably less than 15% after a pressure cooker boiling test based on JIS K5600-5-6 in the case where the ES sheet is hot-pressed onto the entire main surface of the bare silicon wafer at 120°C and 5MPa for 3 minutes, and then treated at 180°C for 2 hours. More preferably, it is less than 10%, and even more preferably, it is less than 5%.

[0093] On the entire main surface of a 12-inch bare silicon wafer, a lattice structure with half-cut grooves 200 μm wide and 200 μm deep at 4000 μm intervals is formed. The ES wafer is then thermo-bonded at 120°C and 5 MPa for 3 minutes and cured at 180°C for 2 hours to obtain the SC layer. For the SC layer, the covered bumps (in...) Figure 6 In the example, the resistance value between the center of the SC layer of the multilayer wiring structure portion 14 (the protrusion sealed by the sealing resin 7) and the center of the same protrusion located at an adjacent position (between the shielding layers on adjacent protrusions) is preferably 5mΩ to 300mΩ. The upper limit of the resistance value is more preferably 150mΩ, more preferably 100mΩ, and more preferably 50mΩ. The lower limit of the resistance value is more preferably 7mΩ, more preferably 10mΩ, and more preferably 15mΩ.

[0094] As described above, the shielding film 30 comprises an adhesive component and a conductive filler (F). The shielding film 30 is heat-cured to become a shielding layer 20 as a cured material. The thickness of the shielding film 30 is, for example, 5 μm to 100 μm. From the viewpoint of balancing wafer processing adaptability and electromagnetic wave shielding, the lower limit of the thickness of the shielding film 30 is preferably 7 μm, more preferably 10 μm, and even more preferably 20 μm. On the other hand, the upper limit of the thickness of the shielding film is preferably 90 μm, more preferably 75 μm, and even more preferably 50 μm.

[0095] 2-1. Shielding film

[0096] The adhesive component of the shielding membrane 30 serves to retain the filler (F) within the membrane, forming the membrane. The adhesive component includes components that form a cross-linked structure through a curing process.

[0097] A suitable example of an adhesive component is a combination of a high molecular weight resin (P) with a weight average molecular weight (Mw) of 10,000 or more and a curing compound (C) with a Mw of 5,000 or less. By combining the high molecular weight resin (P) with a Mw of 10,000 or more and the curing compound (C) with a Mw of 5,000 or less, the film-forming properties of the ES sheet are excellent, as are its conformability to uneven shapes and its coverage (embedding) of recesses such as half-cut grooves. The curing compound (C) can be an oligomer or a low molecular weight compound. In the case of a low molecular weight compound, Mw is replaced by molecular weight.

[0098] From the viewpoint of improving the coating properties of the semi-cut groove, the upper limit of the Mw of the high molecular weight resin (P) is preferably 300,000, more preferably 250,000, and even more preferably 200,000, and even more preferably 150,000. From the viewpoint of adjusting the elongation at 100°C, the lower limit of the Mw of the high molecular weight resin (P) is more preferably 40,000, even more preferably 60,000, and even more preferably 80,000. As the Mw increases, the elongation at 100°C tends to increase.

[0099] Examples of high molecular weight resins (P) include polyurethane resins, polyurethane urea resins, phenoxy resins, acrylic resins, polyester resins, polyamide resins, polystyrene resins, polycarbonate resins, polyamide-imide resins, polyesteramide resins, polyether ester resins, and polyimide resins. High molecular weight resins (P) can be used alone or in combination with two or more.

[0100] The high molecular weight resin (P) can be any of thermoplastic resin, photocurable resin, or thermosetting resin. From the viewpoint of obtaining a highly reliable SC layer, it is preferable to include a thermosetting resin that can crosslink with the curing compound (C). The thermosetting resin is preferably 50% by mass or more, more preferably 70% by mass or more, more preferably 80% by mass or more, more preferably 90% by mass or more, and may also be 100% by mass, relative to 100% by mass of the high molecular weight resin (P).

[0101] The high molecular weight resin (P) is preferably a thermosetting resin containing reactive functional groups that react with the functional groups of the curing compound (C) to form a cross-linked structure. Reactive functional groups of the high molecular weight resin (P) include carboxyl, hydroxyl, amino, epoxy, oxacyclobutyl, oxazolinyl, oxazinyl, aziridinyl, thiol, isocyanate, capped isocyanate, and silanol. Among these, carboxyl and hydroxyl groups are suitable for maintaining the stability of the electromagnetic wave shielding sheet.

[0102] The acid value of the high molecular weight resin (P) is preferably 3 mg KOH / g to 30 mg KOH / g. Setting the acid value to this range improves the adhesion to the wafer. More preferably, the acid value is 4 mg KOH / g to 25 mg KOH / g, and even more preferably 5 mg KOH / g to 20 mg KOH / g. Examples of high molecular weight resins (P) with suitable thermosetting properties include resins having carboxyl groups and / or hydroxyl groups (polyurethane resins, polyurethane urea resins, phenoxy resins, acrylic resins, polyester resins, polyamide resins, epoxy resins, polystyrene resins, polycarbonate resins, polyamide-imide resins, polyesteramide resins, polyether ester resins, and polyimide resins).

[0103] From the viewpoint of possessing both the elongation at 100°C (100% to 1500%) of this ES sheet and the Young's modulus at 100°C (100 MPa to 1000 MPa) after the curing treatment, the Tg of the high molecular weight resin (P) is preferably -20°C to 40°C, more preferably -10°C to 30°C, and even more preferably 0°C to 20°C. When there are two or more high molecular weight resins (P), it is preferable that the high molecular weight resin (P) as the main component with the largest proportion satisfies -20°C to 40°C, and the main component is preferably 50% by mass or more, more preferably 70% by mass or more, and even more preferably 90% by mass or more, relative to the high molecular weight resin (P).

[0104] Curing compounds (C) with a Mw of less than 5,000 play a role in forming a cross-linked structure, and also improve the flexibility of the coated ES sheet and provide excellent conformability to uneven shapes. In addition, the cross-linked network is constructed after curing, thereby obtaining a highly reliable SC layer.

[0105] The content of the curing compound (C) is preferably 5 to 100 parts by mass relative to 100 parts by mass of the high molecular weight resin (P). The lower limit of the content of the curing compound (C) is more preferably 10 parts by mass, further preferably 12 parts by mass, even more preferably 15 parts by mass, and particularly preferably 20 parts by mass. The upper limit of the content of the curing compound (C) is more preferably 80 parts by mass, even more preferably 70 parts by mass, even more preferably 60 parts by mass, and particularly preferably 50 parts by mass.

[0106] Examples of curing compounds (C) include epoxy-containing compounds (E), isocyanate compounds, compounds containing carbodiimide groups, aziridine compounds, compounds containing acid anhydride groups, dicyandiamide compounds, amine compounds such as aromatic diamine compounds, organometallic compounds such as metal chelate compounds, compounds containing maleimide groups, and phenolic compounds such as phenolic varnish resins. From the viewpoint of improving the flexibility of the ES sheet during coating and improving the reliability after coating, it is preferable to include epoxy-containing compounds (E). From the viewpoint of adjusting the curing speed of semi-curing (stage B curing) and formal curing (stage C curing), it is preferable to use a combination of epoxy-containing compounds (E) and curing compounds other than epoxy-containing compounds (E). As a suitable example, a combination of epoxy-containing compounds (E) and one or more compounds selected from aziridine compounds, isocyanate compounds, and compounds containing maleimide groups can be cited.

[0107] In 100% by mass of the curing compound (C), the content of the epoxy-containing compound (E) is preferably 50% by mass or more, more preferably 70% by mass or more, and even more preferably 85% by mass or more, and even more preferably 90% by mass or more. The upper limit of the content may also be 100% by mass.

[0108] In 100% by mass of the curing compound (C), the other curing compounds used in combination with the epoxy-containing compound (E) are preferably 50% by mass or less, more preferably 30% by mass or less, and even more preferably 15% by mass or less, and even more preferably 10% by mass or less. From the viewpoint of maximizing the effect of the other curing compounds used in combination, the lower limit is preferably 0.1% by mass, more preferably 0.3% by mass, and even more preferably 0.4% by mass.

[0109] Of 100 parts by weight of the adhesive component, the total content of high molecular weight resin (P) and epoxy-containing compound (E) is preferably 70 parts by weight or more, more preferably 80 parts by weight or more, and even more preferably 90 parts by weight or more, and may also be 100 parts by weight.

[0110] The epoxy-containing compound (E) is not particularly limited as long as it has epoxy groups, but from the viewpoint of adjusting the Young's modulus of the cured sheet at 100°C to 1000 MPa to 1000 MPa after being treated at 180°C for 2 hours, a multifunctional epoxy-containing compound (E) with two or more functions is preferred. In hot pressing, the epoxy groups of the epoxy-containing compound (E) are thermally crosslinked with the carboxyl or hydroxyl groups of the thermosetting resin to obtain a crosslinked structure. From the viewpoint of improving the flexibility and conformability of the ES sheet during the coating process and effectively exerting stress relief after coating, an epoxy-containing compound (E) that exhibits a liquid state at room temperature and pressure is suitable.

[0111] From the viewpoint of easily obtaining an SC layer with the aforementioned Young's modulus, the epoxy equivalent of the epoxy-containing compound (E) is preferably 110 g / eq to 1000 g / eq. The lower limit of the epoxy equivalent is more preferably 115 g / eq, and even more preferably 150 g / eq. The upper limit of the epoxy equivalent is more preferably 900 g / eq, even more preferably 750 g / eq, even more preferably 500 g / eq, and particularly preferably 280 g / eq. From the viewpoint of more effectively improving flexibility, the epoxy-containing compound (E) preferably contains 10 to 80 parts by mass relative to 100 parts by mass of the high molecular weight resin (P). By setting this dosage, the flexibility of the shielding film can be improved. By setting the epoxy equivalent of the epoxy-containing compound (E) to 110 g / eq to 1000 g / eq, the crosslinking density in the semi-cured material of the shielding film can be adjusted, effectively improving edge coverage. Here, "edge" refers to the edges, corners, etc., of the ends of the uneven portions. Furthermore, epoxy equivalent is expressed as grams [g / eq] of epoxy compound containing 1 gram equivalent of epoxy groups, and is determined according to the method specified in JIS K 7236.

[0112] Compounds containing epoxy groups (E) include, for example, glycidyl ether type epoxy compounds, glycidyl amine type epoxy compounds, glycidyl ester type epoxy compounds, and cyclic aliphatic (alicyclic) epoxy compounds.

[0113] Examples of glycidyl ether type epoxy compounds include bisphenol A type epoxy compounds, bisphenol F type epoxy compounds, bisphenol S type epoxy compounds, bisphenol AD ​​type epoxy compounds, cresol phenolic varnish type epoxy compounds, phenolic varnish type epoxy compounds, α-naphthol phenolic varnish type epoxy compounds, bisphenol A type phenolic varnish type epoxy compounds, dicyclopentadiene type epoxy compounds, tetrabromobisphenol A type epoxy compounds, brominated phenolic varnish type epoxy compounds, tris(glycidyloxyphenyl)methane, and tetra(glycidyloxyphenyl)ethane.

[0114] Examples of glycidylamine type epoxy compounds include tetraglycidyl diaminodiphenylmethane, triglycidyl p-aminophenol, triglycidyl m-aminophenol, and tetraglycidyl m-phenylenediamine.

[0115] Examples of glycidyl ester type epoxy compounds include diglycidyl phthalate, hexahydrodiglycidyl phthalate, and tetrahydrodiglycidyl phthalate.

[0116] Examples of cyclic aliphatic (alicyclic) epoxy compounds include epoxycyclohexylmethyl-epoxycyclohexane carboxylate and bis(epoxycyclohexyl) adipate. Liquid epoxy compounds are also suitable for use.

[0117] The epoxy-containing compound (E) preferably also has other functional groups besides epoxy. Examples of other functional groups include hydroxyl, secondary amino, and tertiary amino groups. By using an epoxy-containing compound (E) that has other functional groups besides epoxy (difunctional or higher), the crosslinking density under specified curing conditions can be effectively increased, and the pressure cooker test (PCT) resistance can be improved. Furthermore, by having hydroxyl and / or amino groups, the adhesion to substrates such as wafers can be improved, resulting in both good PCT resistance and adhesion.

[0118] The adhesive component may include components other than those described herein without departing from the spirit of this disclosure. For example, it may also include tackifying resins, thermoplastic resins, thermosetting resins, photosetting resins, etc., with a Mw of less than 10,000. Examples of tackifying resins include rosin-based resins, terpene-based resins, alicyclic petroleum resins, and aromatic petroleum resins.

[0119] Examples of conductive fillers (F) include metal particles, conductive metal oxide particles, particles with conductive polymers, and particles coated with metal.

[0120] Examples of metal particles include metal powders of gold, silver, copper, palladium, aluminum, nickel, iron, titanium, manganese, zinc, tungsten, platinum, lead, tin, etc., as well as alloy powders of solder, steel, stainless steel, etc., and core-shell type silver-coated copper powder, gold-coated copper powder, silver-coated nickel powder, and gold-coated nickel powder. Excellent electrical conductivity can be obtained by using filler (F) containing silver. The silver content in silver-coated copper is preferably 6% to 20% by mass in 100% by mass of filler (F), more preferably 8% to 17% by mass, and even more preferably 10% to 15% by mass. In the case of core-shell type filler, the coating coverage relative to the core is preferably 60% by mass or more on average in 100% by mass of the entire surface, more preferably 70% by mass or more, and even more preferably 80% by mass or more.

[0121] Examples of metal oxide particles include zinc oxide, indium oxide, and tin oxide, which are electrically conductive.

[0122] Examples of conductive polymer particles include polyacetylene particles, polythiophene particles, polypyrrole particles, or particles on which these are coated.

[0123] Examples of particles used for metal coating include particles that coat the surface of resin particles with metals such as gold or silver, and particles that coat the surface of inorganic particles such as glass or ceramics with metals.

[0124] Examples of conductive carbon materials include carbon black, acetylene black, Ketjen black, graphite, carbon nanotubes, graphene, fullerene, carbon nanotube coils, carbon microcoils, and carbon fibers.

[0125] The shape of the packing material (F) can be exemplified as sheet-like (scale-like), dendritic (dendritic), fibrous, needle-like, or spherical. The packing material (F) can be used alone or in combination. When used in combination, examples include combinations of sheet-like packing material and dendritic packing material, sheet-like packing material, dendritic packing material and spherical packing material, and sheet-like packing material and spherical packing material. Of these, from the viewpoint of improving the edge coverage of the SC layer, the use of sheet-like packing material alone or a combination of sheet-like packing material and dendritic packing material is more preferred.

[0126] The average particle size D of the sheet-like packing 50 Preferably, the particle size is 0.5 μm to 50 μm, more preferably 1 μm to 30 μm. Further preferably, it is 2 μm to 20 μm, and particularly preferably 2 μm to 10 μm. The average particle size D of the dendritic filler (F) is... 50 The preferred range is also the same, preferably 2μm to 100μm, more preferably 2μm to 80μm. Further preferably 3μm to 50μm, and particularly preferably 5μm to 20μm.

[0127] The specific surface area of ​​the sheet-like packing is preferably 0.2 m². 2 / g~4.0m 2 / g, more preferably 0.4m 2 / g~3.5m 2 / g. More preferably 0.5m. 2 / g~3.0m 2 / g, preferably 1.0m 2 / g~2.5m 2 / g. The preferred range for the specific surface area of ​​the dendritic packing is also the same, preferably 0.2 m². 2 / g~2.0m 2 / g, more preferably 0.3m 2 / g~1.8m 2 / g. Preferably, it is 0.4m. 2 / g~1.6m 2 / g, preferably 0.5m 2 / g~1.5m 2 / g.

[0128] From the viewpoint of obtaining excellent electromagnetic wave shielding properties, the content of filler (F) is preferably 45% to 85% by mass relative to 100% by mass of the sheet. The lower limit is more preferably 50% by mass, and even more preferably 55% by mass. The upper limit is more preferably 82% by mass, and even more preferably 80% by mass.

[0129] From the perspective of achieving excellent electromagnetic wave shielding properties and close adhesion to the wafer, the average specific surface area [m²] of the filler (F) is crucial. 2 The product of [g] and the content [g] of filler (F) relative to 100 parts by mass of the binder component is preferably 50m. 2 ~1200m 2 More preferably 100m 2 ~1000m 2 Therefore, 200m is preferred. 2 ~800m 2 300m is particularly preferred. 2 ~600m 2 .

[0130] In addition to conductive fillers (F), shielding films may also contain electromagnetic wave absorbing fillers. Examples of electromagnetic wave absorbing fillers include dielectric loss electromagnetic wave absorbing materials such as carbon particles, or magnetic loss electromagnetic wave absorbing materials such as ferrites or soft magnetic metal powders.

[0131] Examples of electromagnetic wave absorbing fillers include ferroalloys such as iron, Fe-Ni alloys, Fe-Co alloys, Fe-Cr alloys, Fe-Si alloys, Fe-Al alloys, Fe-Cr-Si alloys, Fe-Cr-Al alloys, and Fe-Si-Al alloys; ferrite-oxygen systems such as Mg-Zn ferrite, Mn-Zn ferrite, Mn-Mg ferrite, Cu-Zn ferrite, Mg-Mn-Sr ferrite, and Ni-Zn ferrite; and carbon fillers. Examples of carbon fillers include acetylene black, Ketjen black, furnace black, carbon black, carbon fibers, carbon nanotubes, graphene fillers, graphite fillers, and carbon nanowalls.

[0132] This ES sheet is particularly suitable for applications involving the overall coating of wafers with half-cut grooves. Additionally, this ES sheet can be used in all applications where electromagnetic shielding is desired when attaching it to an object. It can also provide lateral shielding for semiconductor devices. Furthermore, the ability to perform overall coating increases design freedom and offers excellent versatility.

[0133] The elongation at 100°C of this ES sheet can be adjusted by the type, molecular weight, content, and functional groups of the adhesive components. For example, it can be adjusted by the amount of high molecular weight resin (P) and epoxy-containing compound (E). Increasing the molecular weight (Mw) of the high molecular weight resin (P) tends to increase the elongation. Conversely, decreasing the tandem glyc (Tg) of the high molecular weight resin (P) tends to increase the elongation. The elongation at 100°C can be adjusted by keeping the epoxy equivalent of the epoxy-containing compound (E) within the aforementioned range. Furthermore, the elongation can be adjusted by the combination of high molecular weight resin (P) and epoxy-containing compound (E).

[0134] The Young's modulus at 100°C of the hardened sheet after being treated at 180°C for 2 hours tends to increase with increasing filler content. Furthermore, the Young's modulus tends to increase with increasing the Tg of the high molecular weight resin (P) or increasing the acid value.

[0135] As a method for achieving a Young's modulus of 100 MPa to 1000 MPa at 100 °C in a hardened sheet after processing the ES sheet at 180 °C for 2 hours, there are alternatives to or in combination with this method that control the modulus by the type or amount of filler (F). The average particle size D of the filler (F) is changed. 50 The Brunauer-Emmett-Teller (BET) method is also effective in controlling Young's modulus by its specific surface area, tap density, and surface treatment.

[0136] As a method for achieving a peel rate of less than 15% in the SC layer derived from the ES wafer after hot-pressing the entire main surface of a bare silicon wafer at 120°C and 5MPa for 3 minutes and then treating it at 180°C for 2 hours, following a pressure cooker test based on JIS K5600-5-6, the type or amount of high molecular weight resin (P) and epoxy-containing compound (E) can be adjusted. As the Mw of the high molecular weight resin (P) increases, the cohesive force within the wafer increases, thus tending to reduce the peel rate. Furthermore, as the acid value of the high molecular weight resin (P) increases, the interaction at the interface of the wafer and other adhered materials increases, thus tending to reduce the peel rate. Additionally, the adhesion force can be adjusted by modifying the acid value or Mw of the high molecular weight resin (P) and the epoxy equivalent of the epoxy-containing compound (E).

[0137] Within the scope of this disclosure, the shielding film may contain organic or inorganic fillers other than filler (F), and various additives. Specifically, it may contain monomers, oligomers, curing accelerators, curing retarders, silane coupling agents, colorants, flame retardants, antistatic agents, antioxidants, softeners, surface conditioners, lubricants, anti-blocking agents, and adhesion improvers, etc.

[0138] 2-2. Non-shielding film

[0139] The unshielded film contains at least an adhesive component. The unshielded film may contain organic fillers and / or inorganic fillers. By combining organic or inorganic fillers with the adhesive component, the properties of the adhesive component can be improved. For example, mechanical properties, thermal properties, processability, flame retardancy, transparency, refractive properties, heat dissipation, dispersibility, etc., can be imparted.

[0140] Examples of inorganic fillers include silicon dioxide, aluminum oxide, titanium oxide, zinc oxide, antimony trioxide, magnesium oxide, tin oxide, zirconium oxide, magnesium hydroxide, barium sulfate, calcium carbonate, talc, kaolin, mica, sericite, montmorillonite, bentonite, alkali magnesium carbonate, boron nitride, aluminum nitride, and titanium nitride.

[0141] Suitable examples of adhesive components include resins similar to those used in shielding films. Fillers can be appropriately selected based on the function of the non-shielding film. For example, when it is desired to impart thermal conductivity to the non-shielding film, in addition to conductive fillers, examples include metal oxides such as boron nitride, aluminum nitride, gallium nitride, etc.; aluminum oxide, silicon dioxide, titanium oxide, zirconium oxide, zinc oxide, tin oxide, copper oxide, nickel oxide, etc.; metal hydroxides and hydrated metal compounds such as aluminum hydroxide, boehmite, magnesium hydroxide, calcium hydroxide, zinc hydroxide, silicic acid, iron hydroxide, copper hydroxide, barium hydroxide, zirconium oxide hydrate, tin oxide hydrate, basic magnesium carbonate, hydrotalcite, dawsonite, borax, zinc borate, etc.; carbides such as silicon carbide, boron carbide, nitrogen carbide, calcium carbide, etc.; carbonates such as calcium carbonate; titanates such as barium titanate, potassium titanate, etc.; carbon-based materials such as carbon black, carbon nanotubes, carbon fibers, diamond; glass; and other inorganic materials.

[0142] 2-3. Manufacturing method of electromagnetic wave shielding sheet

[0143] The manufacturing method of this ES chip is described below. However, the manufacturing method of this ES chip is not limited to the method described below.

[0144] First, a resin composition for obtaining the film constituting this ES sheet is prepared. The resin composition for obtaining the shielding film is obtained by mixing filler (F), binder components, and solvents. The mixing method is not limited as long as uniform mixing is possible. The resin composition for obtaining non-shielding films such as protective films is obtained by mixing binder components and solvents.

[0145] To improve the uniform dispersion of the packing material, mixing devices can be used. Examples include agitators with blades (Henschel mixers, pressure kneaders, Banbury mixers, planetary mixers, etc.), media pulverizers (ball mills, grinding mills, basket mills, sand mills, sand grinding machines, Dyno mills, dispersants, SC mills, spike mills, or agitator mills, etc.), and dispersion devices with other mechanisms (microfluidizers, nanomizers, ultimizers, ultrasonic homogenizers, dissolvers, dispersants, high-speed impellers, rotary mixers, colloid mills, thin-film cyclone mixers, etc.). Alternatively, degassing can be performed simultaneously with mixing.

[0146] The viscosity of the resin composition can be appropriately set according to the desired film thickness. The shielding film is obtained by applying the prepared resin composition to a release substrate and then heating and drying it. Similarly, the non-shielding film is obtained by applying the prepared resin composition to a release substrate and then heating and drying it. Methods for applying the resin composition include, for example, gravure coating, kiss coating, mold coating, lip coating, comma coating, scraper coating, roller coating, knife coating, spray coating, bar coating, spin coating, and dip coating.

[0147] When this ES sheet contains only a shielding film, it is obtained by peeling the film off from a release substrate. Alternatively, when this ES sheet has a laminated structure of shielding film / non-shielding film, it can be laminated simply to bond the individual films together. Furthermore, a laminate can be obtained by coating a resin composition for forming a non-shielding film onto the shielding film formed on the release substrate and then heating and drying it. Alternatively, a laminate can also be obtained by coating a resin composition for forming a shielding film onto the non-shielding film formed on the release substrate and then heating and drying it. The non-shielding film is, for example, a protective film.

[0148] 3. Semiconductor devices and their manufacturing methods

[0149] Figure 9 The diagram shows a schematic cross-sectional view of a major part of a semiconductor device obtained by monolithically forming a shielded wafer. The semiconductor device 201 is formed by monolithically forming a shielded wafer in unit device formation regions. An SC layer 2, obtained by heating and curing an ES wafer, is applied from the device formation region 12 to the half-cut groove 11. The SC layer 2 can be heat-cured before or after monolithization.

[0150] Figure 10 The diagram shows a schematic cross-sectional view of one example of a modified semiconductor device. Figure 9 The example illustrates how SC layer 2 is coated along the sidewalls and bottom of the half-cut groove, but as... Figure 10 As shown, the SC layer 2 can also be filled throughout the half-cut groove. When the width of the half-cut groove is narrow, filling the half-cut groove with the SC layer 2 and then cutting along the scribed lines to monolithize the wafer and the SC layer 2 is an effective method.

[0151] The following describes an example of a method for manufacturing the semiconductor device. However, the method for manufacturing the semiconductor device disclosed herein is not limited to the following method.

[0152] First, in order to form circuit patterns on the bare wafer, an oxide film is formed on the surface of the bare wafer by high-temperature processing. Then, a photosensitive photoresist, an insulating layer, wiring patterns, etc., are formed to form a semiconductor element wafer 1. Next, a multilayer wiring structure section 14, etc., is formed (see reference). Figure 11 Next, a surface protective film is formed as needed. Then, along line 17 (refer to...). Figure 1 A half-cut groove 11 is formed from the surface of the semiconductor element forming wafer 1 to the middle of the wafer (see reference). Figure 12 Semi-cut grooves can be formed by mechanical cutting with rotating blades or by laser cutting.

[0153] As a specific example, the wafer is fixed in a vacuum chuck of the cutting apparatus. Furthermore, from the surface side of the wafer, cutting is performed along scribing lines in the X and Y directions using a cutting blade, thereby forming a semi-cut groove 11 that reaches into the wafer.

[0154] Next, an ES wafer 3 is mounted on the semiconductor device forming wafer 1 with the half-cut groove 11 formed thereon. To improve the coverage of the ES wafer 3 over the half-cut groove 11, such as... Figure 13 As shown, the buffer sheet 33 is preferably mounted on the ES sheet 3. Alternatively, a reinforcing sheet 34 may be stacked on top of the buffer sheet 33 as needed.

[0155] The following of the ES sheet 3 to the half-cut groove 11 is improved by setting the buffer sheet 33. The buffer material is a layer that melts during hot pressing and uses a material with release properties. The pressing force is transferred to the buffer sheet by the reinforcing sheet, thereby improving the embedding of the ES sheet into the stepped portion of the adhered object.

[0156] The semiconductor device forming wafer 1 is fixed on the vacuum adsorption stage 50 (see reference). Figure 14The ES sheet 3, buffer sheet 33, and reinforcing sheet 34 are then thermally bonded together. Before thermal bonding, the ES sheet 3 can be temporarily attached to the upper surface of the semiconductor device forming wafer 1. The temporary attachment method is, for example, by gently thermally pressing the ES sheet 3 onto the entire surface or end of the semiconductor device forming wafer 1 using a heat source.

[0157] The reinforcing sheet 34 can be appropriately selected from resin films, metal plates, etc. Examples include polyethylene terephthalate, polyethylene naphthalate, polyvinyl fluoride, polyvinylidene fluoride, rigid polyvinyl chloride, polyvinylidene chloride, nylon, polyimide, polystyrene, polyvinyl alcohol, ethylene-vinyl alcohol copolymer, polycarbonate, polyacrylonitrile, polybutene, flexible polyvinyl chloride, polyethylene, polypropylene, polyurethane resin, ethylene-vinyl acetate copolymer, polyvinyl acetate, and other plastic sheets; cellophane, high-quality paper, kraft paper, coated paper, and other paper types; various non-woven fabrics; synthetic paper; metal foil; or composite films composed of these. From the viewpoint of processability or cost, polyethylene terephthalate, polyester, polycarbonate, polyimide, and polyphenylene sulfide are preferred. Polyethylene terephthalate and polyimide are even more preferred.

[0158] To facilitate peeling from the SC layer after hot pressing, the buffer layer 33' obtained from the buffer sheet 33 preferably has a release layer formed on the interface with the ES sheet. Examples of such a release layer include polypropylene, polymethylpentene, cyclic olefin polymers, silicone, and fluoropolymers.

[0159] Commercially available buffer layers include those manufactured by Mitsui Tohcello, such as "CR1012," "CR1012MT4," "CR1031," "CR1033," "CR1040," and "CR2031MT4." Most of these commercially available buffer layers are layered structures that utilize polymethylpentene sandwiched between both sides of the buffer layer as release layers. In this specification, the integral structure including the release layer is referred to as a buffer sheet. By stacking a reinforcing sheet on one side, embedding properties and substrate cracking can be improved.

[0160] The thickness of the buffer layer is preferably 50 μm to 300 μm, more preferably 75 μm to 250 μm, and even more preferably 100 μm to 200 μm. Setting it to 50 μm or more improves embeddability. Setting it to 300 μm or less improves the processability of the ES sheet. Furthermore, the thickness of the buffer layer includes the release layer when a release layer is present.

[0161] The thickness of the reinforcing sheet 34 is preferably 20 μm or more, more preferably 25 μm or more, and even more preferably 38 μm or more. By setting the thickness of the reinforcing sheet to 20 μm or more, the strength of the reinforcing sheet is improved, thus further improving embeddability, demolding properties, and processability. The thickness of the reinforcing sheet is not particularly limited, but when it is 250 μm or less, the demolding properties and processability of the ES sheet are improved, and therefore preferred.

[0162] By hot-pressing the ES sheet 3 onto the wafer, an SC layer 2 is formed on the semiconductor device forming wafer 1. The pressing substrate 40 is lowered from above the reinforcing sheet 34 and hot-pressed (see reference). Figure 14 The ES wafer 3 is pressed by the melting of the buffer wafer 33, extending along the half-cut groove provided on the wafer, following the multilayer wiring structure 14 and the half-cut groove 11, thereby forming the SC layer 2 (see reference). Figure 15 ).

[0163] The temperature of the hot pressing process is preferably above the melting temperature of the buffer sheet 33 and below the melting temperature of the reinforcing sheet 34. By setting this temperature, the buffer sheet can be melted while maintaining the strength of the reinforcing sheet. The heating temperature of the hot pressing process is preferably 100°C or higher, more preferably 110°C or higher, and even more preferably 120°C or higher. In addition, as an upper limit, it depends on the heat resistance of the multilayer wiring structure 14, but is preferably 220°C or lower, more preferably 200°C or lower, and even more preferably 180°C or lower.

[0164] The pressure during the hot pressing process is appropriately set according to the thickness of the wafer to prevent it from cracking. For example, it is approximately 1 MPa to 15 MPa. More preferably, it is 1.5 MPa to 10 MPa, and even more preferably, it is 2 MPa to 5 MPa. The hot pressing time is, for example, approximately 1 minute to 2 hours. Hardening treatment can be completed during the hot pressing process, or a separate hardening treatment process can be performed after hot pressing. Furthermore, the thermosetting resin in the adhesive component can be partially or substantially hardened before hot pressing, provided it is still flowable. Hot pressing equipment can include press-type hot pressing equipment, transfer molding equipment, compression molding equipment, vacuum air forming equipment, etc.

[0165] Then, the pressing substrate 40 is released, and the buffer layer 33' and reinforcing sheet 34 are removed. After these processes, the desired product is obtained. Figure 2 The shielding process chip shown. It can also be as follows: Figure 5 As shown, the upper surface is removed by etching.

[0166] Furthermore, while the described embodiment illustrates an example using overlapping ES sheet 3, buffer sheet 33, and reinforcing sheet 34, laminates formed by joining in any combination can also be used. For example, laminates with ES sheet / buffer sheet / reinforcing sheet, ES sheet / buffer sheet, or buffer sheet / reinforcing sheet bonded together can be used. By joining the reinforcing sheet and the buffer sheet, peelability can be significantly improved.

[0167] Next, a single-wafer process is performed along the scribing lines. Specifically, the shielding wafer is single-wafered. The single-wafering method can be the same as the half-groove method, using a rotating blade, laser grooving, or other mechanical cutting techniques. Alternatively, the wafer can be cut by grinding the back side of the wafer to reduce its thickness to the half-groove level.

[0168] [Example]

[0169] The present disclosure will be described in more detail below through examples, but this does not limit the scope of the disclosure in any way. In addition, "parts" and "%" in the examples mean "parts by mass" and "% by mass".

[0170] (a) Measurement method

[0171] The numerical value obtained in this embodiment is obtained through the following method.

[0172] (i) Weight-average molecular weight (Mw)

[0173] Mw was determined using a gel permeation chromatograph (GPC) "HPC-8020" manufactured by Tosoh Corporation. GPC is a high-performance liquid chromatograph that separates and quantifies substances dissolved in a solvent (THF (Tetrahydrofuran)) based on the difference in their molecular size. The determination was performed using two "LF-604" (Showa Denko Corporation: GPC column for rapid analysis; 6 mm inner diameter (ID) × 150 mm) connected in series in a column, at a flow rate of 0.6 mL / min and a column temperature of 40 °C. The weight-average molecular weight (Mw) was determined using polystyrene conversion.

[0174] (ii) Acid value of the resin

[0175] Accurately measure approximately 1 g of resin into a stoppered Erlenmeyer flask, add 50 mL of a toluene / ethanol mixture (volume ratio: toluene / ethanol = 2 / 1) and dissolve. Add phenolphthalein indicator and maintain for 30 seconds. Then, titrate with 0.1 mol / L potassium hydroxide solution until the solution turns pale pink. The acid value is calculated using the following formula. The acid value is assumed to be the value of the resin in its dry state.

[0176] Acid value (mgKOH / g) = (a × F × 56.1 × 0.1) / S

[0177] S: Sample collection volume × (sample solid content / 100) (g)

[0178] a: Titration volume (mL) of 0.1 mol / L alcoholic potassium hydroxide solution

[0179] F: The force value of a 0.1 mol / L alcoholic potassium hydroxide solution.

[0180] (iii) Tg of the resin

[0181] According to JIS K7198, Tg was determined using a DVA-200 dynamic viscoelasticity measuring device (manufactured by IT Measurement & Control Co., Ltd.). A 50 μm thick polyethylene terephthalate (PET) film coated with a silicone release agent was prepared as the release substrate. Resin was applied to the release substrate with a thickness of 20 μm using a doctor blade. The resulting sheet, dried at 100°C for 2 minutes, was cut into 0.5 cm × 3 cm pieces. The sheets after peeling off the release film were used for measurement. In the measurement, the deformation mode was tension, and the temperature at which the main dispersion peak of the loss tangent (tanδ) appeared, measured at a strain of 0.08%, a frequency of 10 Hz, and a heating rate of 10°C / min, was defined as Tg.

[0182] (iv) Fabrication of experimental half-cut wafers

[0183] Prepare a bare silicon wafer (size 100mmφ, thickness 525μm) and use a dicing device (DISCO DAD323) to obtain a test half-diced wafer with half-diced grooves formed at 4000μm grid intervals, each 200μm wide and 200μm deep.

[0184] (b) Manufacturing of resin compositions, electromagnetic wave shielding sheets and laminates

[0185] [Preparation of the resin composition of Example 1]

[0186] 100 parts of the solid component of high molecular weight resin P3, 40 parts of epoxy-containing compound E3, 1 part of curing compound C1, 180 parts of filler F2, and 35 parts of filler F4 were added to a container, along with a toluene:isopropanol (mass ratio 2:1) mixed solvent to achieve a non-volatile component (solid component) concentration of 35%. The mixture was stirred for 10 minutes using a disperser to obtain the resin composition. The converted solid component amounts for each component are listed in Table 1.

[0187] [Examples 2 to 20 and Comparative Examples 1 to 6]

[0188] Except for the changes shown in Tables 1 to 3, the resin composition was manufactured in the same manner as in Example 1.

[0189] The following describes the materials used in the embodiments and the abbreviations in Tables 1 to 3.

[0190] <Adhesive Composition>

[0191] [High molecular weight resin (P)]

[0192] • P1: Polycarbonate resin, Mw = 180,000, acid value 10 [mgKOH / g], Tg 10℃ (manufactured by Toyo Chemical Co., Ltd.)

[0193] • P2: Polycarbonate resin, Mw = 260,000, acid value 10 [mgKOH / g], Tg 10℃ (manufactured by Toyo Chemical Co., Ltd.)

[0194] • P3: Polycarbonate resin, Mw = 120,000, acid value 10 [mgKOH / g], Tg 10℃ (manufactured by Toyo Chemical Co., Ltd.)

[0195] • P4: Polycarbonate resin, Mw = 110,000, acid value 12 [mgKOH / g], Tg -10℃ (manufactured by Toyo Chemical Co., Ltd.)

[0196] P5: Polycarbonate resin, Mw = 50,000, acid value 18 [mgKOH / g], Tg 20℃ (manufactured by Toyo Chemical Co., Ltd.)

[0197] • P6: Polycarbonate resin, Mw = 110,000, acid value 3 [mgKOH / g], Tg 10℃ (manufactured by Toyo Chemical Co., Ltd.)

[0198] • P7: Polycarbonate resin, Mw = 110,000, acid value 28 [mgKOH / g], Tg 10℃ (manufactured by Toyo Chemical Co., Ltd.)

[0199] • P8: Carbamate resin, Mw = 130,000, acid value 10 [mgKOH / g], Tg 40℃ (manufactured by Toyo Chemical Co., Ltd.)

[0200] • P9: Carbamate resin, Mw = 130,000, acid value 10 [mgKOH / g], Tg 60℃ (manufactured by Toyo Chemical Co., Ltd.)

[0201] • P10: Ester resin, Mw = 140,000, acid value 10 [mgKOH / g], Tg -15℃ (manufactured by Toyo Chemical Co., Ltd.)

[0202] [Other Resins]

[0203] • R1: Acrylic resin, Mw = 8,000, acid value 15 [mgKOH / g] (manufactured by Toyo Chemical Co., Ltd.)

[0204] <Curing compound (C)>

[0205] • C1: "Chemitite PZ-33" (aziridine compound, Mw=425), manufactured by Nippon Catalyst Co., Ltd.

[0206] [Compounds containing epoxy groups (E)]

[0207] E1: "jER604" (diaminodiphenylmethane type epoxy resin, Mw=350, epoxy equivalent=120g / eq), manufactured by Mitsubishi Chemical Corporation.

[0208] E2: "jER1032H" (Triphenol methane type epoxy resin, Mw=500, epoxy equivalent=170g / eq), manufactured by Mitsubishi Chemical Corporation.

[0209] E3: "jER834" (Bisphenol A type epoxy resin, Mw=470, epoxy equivalent=250g / eq), manufactured by Mitsubishi Chemical Corporation.

[0210] • E4: “EPICLON 1050” (Bisphenol A type epoxy resin, Mw=900, epoxy equivalent=475g / eq), manufactured by DIC.

[0211] • E5: “EPICLON 3050” (Bisphenol A type epoxy resin, Mw=1800, epoxy equivalent=800g / eq), manufactured by DIC Corporation.

[0212] [Other hardening compounds]

[0213] • R2: "jER1010" (Bisphenol A type epoxy resin, Mw=5500, epoxy equivalent=4000g / eq), manufactured by Mitsubishi Chemical Corporation

[0214] <Conductive filler (F)>

[0215] F1: Flake-like silver filler (D) 50 =1.0μm~3.0μm, average specific surface area 1.1m²2 / g) Manufactured by Tokusen Industries, Ltd., Japan

[0216] F2: Flake-like silver filler (D) 50 =4.0μm~7.0μm, average specific surface area 1.5m² 2 / g) Manufactured by Fukuda Metal Industries, Ltd.

[0217] F3: Flake-like silver filler (D) 50 =5.0μm~10.0μm, average specific surface area 0.3m² 2 / g) Manufactured by Fukuda Metal Industries, Ltd.

[0218] •F4: Dendritic silver-coated copper filler (D 50 =7.4μm, average specific surface area 0.7m² 2 / g) Manufactured by Mitsui Metals Mining Co., Ltd.

[0219] F5: Dendritic silver-coated copper filler (flake-like silver filler D) 50 =10.4μm, average specific surface area 0.6m² 2 / g) Manufactured by DOWA Corporation

[0220] [Table 1] Table 1

[0221]

[0222] [Table 2] Table 2

[0223]

[0224] [Table 3]

[0225] Table 3

[0226]

[0227] (Manufacturing of electromagnetic wave shielding sheets)

[0228] A 50 μm thick PET film coated with a silicone release agent was prepared as a release substrate. The resin compositions of each embodiment and comparative example were applied to the release substrate using a doctor blade to achieve a dry thickness of 40 μm. Then, the electromagnetic wave shielding sheets with release substrates of each embodiment and comparative example were obtained by drying at 100°C for 2 minutes.

[0229] (Creating a layered body)

[0230] Next, a release-type buffer component was prepared. Using a hot laminator, the surface of the electromagnetic wave shielding sheet with release-type substrate of each embodiment and comparative example was laminated with the buffer sheet (CR1040 manufactured by Mitsui Tohcello) at a temperature of 70°C, a pressure of 0.1 MPa, and a speed of 1 m / min, thereby obtaining the laminate of each embodiment and comparative example.

[0231] (c) Characteristics of electromagnetic wave shielding sheets, etc.

[0232] For the embodiments and comparative examples described, the elongation and Young's modulus were determined using the following method. The results are shown in Tables 1 to 3.

[0233] <Elongation at 100℃>

[0234] Electromagnetic wave shielding sheets, after being stripped of their release substrate and buffer sheet, were placed in a constant temperature and humidity chamber at 23°C and 50% relative humidity for 24 hours, and then placed in a chamber maintained at 100°C for 1 minute. Then, at 100°C, the stress-strain curves of the electromagnetic wave shielding sheets were measured using an EZ tensile testing machine (manufactured by Shimadzu Corporation) at a tensile speed of 50 mm / min and a mark interval of 25 mm. The elongation at the fracture point was measured and recorded as the elongation at 100°C.

[0235] <Young's modulus of the hardened sheet at 100°C>

[0236] An electromagnetic wave shielding sheet, after the release agent and buffer sheet have been removed, was heated at 180°C for 2 hours to obtain a hardened sheet. After standing in a constant temperature and humidity chamber at 23°C and 50% relative humidity, it was then placed in a chamber maintained at 100°C for 1 minute. Then, at 100°C, the stress-strain curve of the hardened sheet was measured using an EZ tensile testing machine (manufactured by Shimadzu Corporation) under tensile conditions of 50 mm / min and 25 mm between markings. The linear regression (slope) of the strain (elongation) range of 0.1% to 0.3% was measured as the Young's modulus at 100°C.

[0237] (d) Evaluation of electromagnetic wave shielding sheets, etc.

[0238] For the embodiments and comparative examples described, adhesion, coverage, warpage, and appearance were evaluated using the following methods. The results are shown in Table 4.

[0239] <Adhesion strength to bare silicon wafers after PCT test>

[0240] Prepare a bare silicon wafer (100mm φ, 525μm thickness), cut the laminate into 50mm × 50mm pieces, peel off the release substrate, and place the electromagnetic wave shielding layer on the bare wafer. Then, heat-press the bare wafer from above the buffer layer of the laminate at 120°C and 5MPa for 3 minutes. After heat pressing, cool and peel off the buffer layer, then heat at 180°C for 2 hours to obtain a test piece with a shielding layer formed. Subsequently, the test substrate is subjected to an autoclave test (conditions: 130°C, 85% RH, 0.12MPa, 96 hours). Then, using a cross-cutting guide according to JIS K5400, form 100 checkerboard patterns with a spacing of 1mm on the shielding layer of the test substrate. Then, press the adhesive tape firmly onto the checkerboard pattern, peel off the end of the tape at a 45° angle in one go, and evaluate the condition of the checkerboard pattern according to the following criteria.

[0241] +++: Peeling rate less than 5%.

[0242] ++: The coating partially peels off along the cut line, with a peeling rate of 5% or more but less than 10%.

[0243] +: The coating partially peels off along the cut line, and the peeling rate is more than 10% but less than 15%.

[0244] NG: The coating has partially or completely peeled off along the cut line, with a peeling rate of more than 15%. Not suitable for practical use.

[0245] <Resistance value between half-cut slots>

[0246] The laminate was cut into 100mm φ pieces, and the release substrate was peeled off. An electromagnetic wave shielding layer was then placed on a test half-cut wafer. The test half-cut wafer was then hot-pressed from above the buffer layer of the laminate at 120°C and 5MPa for 3 minutes. After hot pressing and cooling, the buffer layer was peeled off, and the wafer was heated at 180°C for 2 hours to obtain the shielded wafer. Then, using an RM3544 (manufactured by HIOKI) and pin-type lead probes, the resistance between the half-cut grooves was evaluated by contacting the probes at the center of the upper surface of the shielding layer in the formation regions of two adjacent semiconductor devices. The evaluation criteria are as follows.

[0247] +++: The resistance value is less than 50mΩ. This is a very good result.

[0248] ++: A resistance value of 50mΩ or higher and less than 150mΩ is a good result.

[0249] +: Resistance value is above 150mΩ and less than 300mΩ. Practical application is not a problem.

[0250] NG: Resistance value above 300mΩ. Not suitable for practical use.

[0251] <Height of warping>

[0252] The obtained shielded wafer is placed on a horizontal plane, and the maximum distance between the placed surface and the edge of the wafer is measured to evaluate the warpage height. The evaluation criteria are as follows.

[0253] +++: Warpage height less than 1mm. This is a very good result.

[0254] ++: A warpage height of 1mm or more but less than 2mm is a good result.

[0255] +: Warpage height is 2mm or more but less than 5mm. Practicality is not an issue.

[0256] NG: Warpage height is 5mm or more. Not suitable for practical use.

[0257] <Appearance of single-component chemical products>

[0258] From the upper surface of the obtained shielding wafer, a full cut of 50 μm width was made using a cutting device (DISCO DAD323) to pass through the center of the half-cut groove, thereby obtaining 100 monolithic products. The number of monolithic products with peeling or defects in the electromagnetic wave shielding was then counted by visual inspection. The evaluation criteria are as follows.

[0259] +++: The number of individual components with peeling or defects in the electromagnetic wave shielding sheet is less than 5. Very good.

[0260] ++: The number of individual components with peeling or defects in the electromagnetic wave shielding sheet is more than 5 but less than 10. Good.

[0261] +: The number of individual components with peeling or defects in the electromagnetic wave shielding sheet is more than 10 but less than 20. Practically, this poses no problem.

[0262] NG: More than 20 individual pieces of the product have peeling or defects in their electromagnetic wave shielding. Unusable.

[0263] [Table 4]

[0264] Table 4

[0265]

[0266] As shown in Comparative Examples 2 and 4, electromagnetic wave shielding sheets with a Young's modulus exceeding 1000 MPa at 100°C in the hardened sheet exhibited high resistance between the half-cut grooves, indicating problems with the coverage of the recesses. If the Young's modulus at 100°C in the hardened sheet was less than 100 MPa, as shown in Comparative Examples 1 and 3, it was confirmed that the peelability deteriorated after the PCT test, resulting in problems with adhesion to the adhered material. Even if the Young's modulus at 100°C in the hardened sheet was less than 1000 MPa, if the elongation at 100°C was high, the peelability after the PCT test became good; however, as shown in Comparative Example 5, it was confirmed that the resistance between the half-cut grooves was high, indicating problems with the coverage of the recesses. In contrast, electromagnetic wave shielding sheets with an elongation of 100% to 1500% at 100°C and a Young's modulus of 100 MPa to 1000 MPa at 100°C after being treated at 180°C for 2 hours were found to be superior in terms of adhesion, coverage, warpage, and appearance, as shown in Examples 1 to 28.

Claims

1. An electromagnetic wave shielding sheet for integrally covering at least one main surface of a semiconductor wafer before monolithization, said semiconductor wafer having half-cut grooves formed in a lattice pattern and element forming regions divided by said half-cut grooves and arranged in a matrix pattern. The electromagnetic wave shielding sheet has at least a shielding film comprising an adhesive component and a conductive filler (F). The elongation of the electromagnetic wave shielding sheet at 100°C is 100%–1500%. The Young's modulus of the hardened sheet after being treated at 180°C for 2 hours is 100MPa to 1000MPa at 100°C.

2. The electromagnetic wave shielding sheet according to claim 1, wherein, For the following shielding layer, namely, the electromagnetic wave shielding sheet is hot-pressed at 120°C and 5MPa for 3 minutes on the entire main surface of a bare silicon wafer, and then treated at 180°C for 2 hours, the peeling rate in the close-fitting test after the electromagnetic wave shielding sheet is subjected to a pressure cooker boiling test based on Japanese Industrial Standard K5600-5-6 is less than 15%.

3. The electromagnetic wave shielding sheet according to claim 1, wherein, The adhesive component comprises a curable compound (C) with a weight average molecular weight of less than 5,000 and a high molecular weight resin (P) with a weight average molecular weight of more than 10,000.

4. The electromagnetic wave shielding sheet according to claim 1, wherein, The content of conductive filler (F) is 45% to 85% by mass.

5. The electromagnetic wave shielding sheet according to claim 1, wherein, Average specific surface area [m²] of conductive filler (F) 2 The product of [g] and the content [g] of conductive filler (F) relative to 100 parts by mass of the adhesive component is 50 [m]. 2 ~1200[m 2 ].

6. The electromagnetic wave shielding sheet according to claim 1, wherein, The curing compound (C) includes epoxy-containing compounds (E) with a weight average molecular weight of less than 5,000. The epoxy equivalent of compounds (E) containing epoxy groups is 110 g / eq to 1000 g / eq. Relative to 100 parts by weight of high molecular weight resin (P), it includes 10 to 80 parts by weight of an epoxy-containing compound (E).

7. The electromagnetic wave shielding sheet according to claim 1, wherein, The shielding layer is formed as follows: on the entire main surface of a 12-inch bare silicon wafer, a half-cut groove with a width of 200 μm and a depth of 200 μm is formed in a grid pattern at intervals of 4000 μm. The electromagnetic wave shielding sheet is hot-pressed at 120°C and 5MPa for 3 minutes and then treated at 180°C for 2 hours. The shielding layer from which the electromagnetic wave shielding sheet originates is covered by the shielding layer on the protrusions located adjacent to the half-cut grooves. The resistance between the shielding layers is 5mΩ to 300mΩ.

8. A shielding wafer having at least one main surface of a semiconductor wafer before monolithization having a shielding layer formed of an electromagnetic wave shielding sheet as described in any one of claims 1 to 7.

9. A semiconductor device, which is formed by monolithically processing a shielded wafer as described in claim 8, with each element forming region as a unit.

10. A method for manufacturing a semiconductor device, comprising: A process of forming half-cut grooves in a semiconductor wafer before monolithization, which has component forming regions formed in a matrix shape along scribing lines; The process of placing an electromagnetic wave shielding sheet as described in any one of claims 1 to 7 on top of the semiconductor wafer; The process of hot-pressing the electromagnetic wave shielding sheet onto the semiconductor wafer; The process of obtaining a shielding layer by heating and hardening the electromagnetic wave shielding sheet; and The process of monolithization is carried out on a unit basis, with the component forming area as the unit.

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