Method for producing protective film-forming film, composite sheet for protective film-forming, and device

Abstract

The present invention provides a protective film-forming film and a composite sheet for forming a protective film, which can improve the adhesion reliability between the sealing resin and the protective film even when a workpiece such as a chip having a protective film formed thereon is further sealed with resin, and a method for manufacturing an apparatus for forming the composite sheet using the protective film-forming film. The protective film-forming film is a protective film-forming film for forming a protective film, and the surface roughness Ra1 of the protective film after heating at 260°C for 5 minutes is 200 nm or less.

Description

Technical Field

[0001] The present invention relates to a protective film-forming film, a composite sheet for forming a protective film, and a method for manufacturing a device. In particular, the present invention relates to a protective film-forming film suitable for protecting workpieces such as wafers or processed products such as chips, a composite sheet for forming a protective film including the protective film-forming film, and a method for manufacturing a device using the protective film-forming film. Background Art

[0002] In recent years, semiconductor devices have been manufactured using a mounting method known as flip-chip bonding. In this method, when mounting a semiconductor chip with a circuit surface having electrodes such as bumps, the circuit surface of the semiconductor chip is flipped over (face down) and connected to a chip mounting portion. As a result, the semiconductor device has a structure in which the back side of the semiconductor chip, where no circuitry is formed, is exposed.

[0003] Therefore, to protect semiconductor chips from impact during transportation, a hard protective film made of an organic material is often formed on the back side of the semiconductor chip. Patent Document 1 discloses laser marking of the protective film, where the contrast between the marked portion and the rest of the portion is at least 20%.

[0004] However, to achieve miniaturization and high-density packaging of semiconductor packages, wafer-level chip scale packages (WLCSP) are singulated, with WLCSP manufactured as chips. A protective film with the same shape as the chip is formed on the surface of the chip where no electrodes are formed.

[0005] Furthermore, in recent years, a system-in-package (SiP) has been utilized in which a plurality of chips having different functions are arranged in one package, thereby achieving both miniaturization and high functionality of semiconductor packages.

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent Document 1: Japanese Patent Application Laid-Open No. 2012-028396 Summary of the Invention

[0009] Technical Problems to be Solved by the Invention

[0010] When a chip with a protective film formed thereon (eg, a WLCSP with a protective film) is mounted in a system-in-package, the chip with the protective film is sealed by covering the exposed portion of the protective film with a sealing resin.

[0011] In such a system-in-package in which a chip sealed with a protective film (for example, a WLCSP with a protective film) is sealed, there arises a problem in which peeling occurs between the sealing resin and the protective film during reliability testing, leading to a decrease in adhesion.

[0012] The present invention has been completed in view of the above-mentioned actual situation, and its purpose is to provide a protective film forming film and a composite sheet for forming a protective film, which can improve the adhesion reliability between the sealing resin and the protective film even when the processed product of the workpiece such as a chip formed with a protective film is further sealed with resin, as well as a method for manufacturing a device using the composite sheet for forming a protective film.

[0013] Technical means to solve technical problems

[0014] The present invention relates to the following aspects.

[0015] [1] A protective film-forming film for forming a protective film, wherein the surface roughness Ra1 of the protective film after heating at 260° C. for 5 minutes is 200 nm or less.

[0016] [2] The protective film-forming film according to [1], wherein the water contact angle of the protective film is 107° or less.

[0017] [3] The protective film-forming film according to [1] or [2], wherein the surface roughness Ra0 of the protective film before heating at 260° C. for 5 minutes is 35 nm or more.

[0018] [4] The protective film-forming film according to any one of [1] to [3], wherein the protective film is a thermally cured product or an energy-ray cured product.

[0019] [5] The protective film-forming film according to any one of [1] to [4], wherein the protective film contains a filler.

[0020] [6] The protective film-forming film according to [5], wherein the filler is composed of two or more fillers having different average particle sizes.

[0021] [7] A composite sheet for forming a protective film, comprising the protective film-forming film according to any one of [1] to [6] laminated on a support sheet.

[0022] [8] A method for manufacturing a device comprising:

[0023] A step of attaching the protective film-forming film according to any one of [1] to [6], or the protective film-forming film included in the composite sheet for forming a protective film according to [7], to the back surface of a workpiece;

[0024] The process of forming the attached protective film into a protective film;

[0025] A process of singulating a workpiece having a protective film or a protective film-forming film on the back thereof to obtain a plurality of workpieces having a protective film or a protective film-forming film;

[0026] A step of placing a workpiece having a protective film or a protective film-forming film on a substrate; and

[0027] A step of heating the workpiece (a workpiece with a protective film) and the substrate placed on the substrate.

[0028] [9] A method for manufacturing a device comprising:

[0029] A step of attaching the protective film-forming film according to any one of [1] to [6], or the protective film-forming film included in the composite sheet for forming a protective film according to [7], to the back surface of a workpiece;

[0030] The process of forming the attached protective film into a protective film;

[0031] The process of laser marking the protective film or protective film forming film in such a way that the height of the printed part is greater than 0 μm;

[0032] A process of singulating a workpiece having a protective film or a protective film-forming film on the back thereof to obtain a plurality of workpieces having a protective film or a protective film-forming film;

[0033] A step of placing a workpiece having a protective film or a protective film-forming film on a substrate; and

[0034] A step of heating the workpiece (a workpiece with a protective film) and the substrate placed on the substrate.

[0035]

[10] A method for manufacturing a device, wherein, after the step of heating the processed product of the workpiece with a protective film arranged on the substrate and the substrate as described in [8] or [9], there is a sealing treatment step of covering the exposed protective film of the processed product of the workpiece with a protective film with a sealing resin.

[0036]

[11] The method for manufacturing a device according to any one of [8] to

[10] , wherein the workpiece is a wafer and the processed product of the workpiece is a chip.

[0037] Effects of the Invention

[0038] According to the present invention, a protective film forming film and a composite sheet for forming a protective film can be provided, which can improve the adhesion reliability between the sealing resin and the protective film even when a processed product such as a chip formed with a protective film is further sealed with resin, as well as a method for manufacturing a composite sheet for forming a protective film. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 This is a schematic cross-sectional view of an example of a chip having a protective film obtained by converting the protective film-forming film of this embodiment into a protective film.

[0040] Figure 2 This is a schematic cross-sectional view of an example of the composite sheet for forming a protective film according to the present embodiment.

[0041] Figure 3 This is a schematic cross-sectional view of another example of the composite sheet for forming a protective film according to the present embodiment.

[0042] Figure 4 It is a schematic cross-sectional view for explaining the step of attaching the composite sheet for forming a protective film according to the present embodiment to a wafer.

[0043] Figure 5 It is a schematic cross-sectional view for explaining the process of singulating a wafer having a protective film formed thereon.

[0044] Figure 6 It is a schematic cross-sectional view for explaining the process of picking up a chip having a protective film formed thereon.

[0045] Figure 7 It is a schematic cross-sectional view for explaining the process of placing a chip having a protective film formed thereon on a substrate.

[0046] Figure 8 A schematic cross-sectional view showing a substrate on which a chip having a protective film formed thereon and other chips are arranged.

[0047] Figure 9 A schematic cross-sectional view of a system-in-package (SIP) in which a chip mounted on a substrate and having a protective film formed thereon is sealed with a sealing resin.

[0048] Description of Reference Numerals

[0049] 10: Chip with protective film; 1: Protective film forming film; 1a: Protective film; 6a: Chip; 6b: Protruding electrode; 3, 3A: Composite sheet for protective film formation; 1: Protective film forming film; 4: Adhesive sheet; 41: Base material; 42: Adhesive layer; 5: Adhesive layer for clamp; 6: Wafer; 7: Ring frame; 50: Substrate; 100: System-level packaging. DETAILED DESCRIPTION

[0050] First, main terms used in this specification are explained.

[0051] In this specification, for example, “(meth)acrylate” is used as a term representing both “acrylate” and “methacrylate”, and the same applies to other similar terms.

[0052] The support sheet refers to a sheet that supports the protective film-forming film. Examples of the support sheet include an adhesive sheet that is a laminate comprising a substrate and an adhesive layer, and a substrate alone. In this embodiment, the support sheet is preferably an adhesive sheet from the perspective of easily controlling the adhesion between the protective film-forming film and the protective film, and from the perspective of easily controlling the surface roughness Ra1 and Ra0 of the protective film, which is also beneficial to the protective film described later.

[0053] Adhesive sheet can also contain other structural layers except base material and adhesive layer.For example, adhesive sheet can have the structure that possesses intermediate layer between base material and adhesive layer.In addition, for the purpose of improving the close adhesion of substrate surface and adhesive layer interface or substrate surface and intermediate layer interface, preventing the transfer of low molecular weight components, it is possible to form primer layer (primer layer) on the substrate surface of adhesive layer side.In addition, it is also possible to laminate the peeling film for protecting adhesive layer before use at the surface of adhesive layer.In addition, base material can be monolayer, it is also possible to be multilayer possessing functional layers such as buffer layer.

[0054] The “front surface” of a workpiece such as a wafer refers to the side on which circuits, electrodes, etc. are formed, and the “back surface” refers to the side on which no circuits, etc. are formed.

[0055] Hereinafter, the present invention will be described in detail through specific embodiments in the following order.

[0056] (1. Protective film forming film)

[0057] The protective film-forming film of the present embodiment is attached to a workpiece and formed into a protective film, thereby forming a protective film for protecting the workpiece or a product processed from the workpiece.

[0058] "Protecting" refers to a state in which the protective film-forming film is rendered sufficiently resistant to protecting a workpiece or a workpiece-processed product. Specifically, when the protective film-forming film of this embodiment is curable, "protecting" refers to converting an uncured protective film-forming film into a cured product. In other words, the protective film-forming film that has been cured is a cured product of the protective film-forming film and is distinct from the protective film-forming film.

[0059] After the workpiece and the curable protective film-forming film are superimposed, the protective film-forming film is cured, whereby the protective film can be firmly bonded to the workpiece, and a durable protective film can be formed.

[0060] On the other hand, when the protective film-forming film of this embodiment does not contain a curable component and is used in an uncured state, the protective film-forming film of this embodiment is converted into a protective film the moment it is attached to a workpiece. In other words, the converted protective film-forming film is the same as the protective film-forming film.

[0061] When high protective performance is not required, the protective film-forming film is easy to use because there is no need to cure the protective film-forming film.

[0062] In this embodiment, the protective film-forming film is preferably curable. Therefore, the protective film is preferably a cured product. Examples of cured products include heat-cured products and energy-ray cured products. In this embodiment, the protective film is more preferably a heat-cured product.

[0063] Furthermore, the protective film-forming film preferably has adhesiveness at room temperature (23°C) or develops adhesiveness by heating. This allows the workpiece and the protective film-forming film to be adhered when they are superimposed. This allows for reliable positioning before the protective film-forming film is cured.

[0064] The workpiece is a plate-like body to which the protective film forming film of this embodiment is attached and processed. Examples of the workpiece include wafers and panels. Specifically, semiconductor wafers and semiconductor panels can be listed. Examples of processed products of the workpiece include chips obtained by singulating wafers. Specifically, semiconductor chips obtained by singulating semiconductor wafers can be listed. In this case, the protective film is formed on the back side of the wafer.

[0065] The protective film-forming film may be composed of a single layer or multiple layers. When the protective film-forming film has multiple layers, these multiple layers may be the same or different from each other, and the combination of the layers constituting these multiple layers is not particularly limited.

[0066] In this embodiment, the protective film-forming film is preferably a single layer. If the protective film-forming film is composed of multiple layers, there is a risk of interlayer delamination or film deformation due to differences in thermal shrinkage between layers during processes involving temperature fluctuations (such as during reflow processing or when using the device). This film deformation can also lead to changes in surface roughness Ra1. However, if the protective film-forming film is composed of a single layer, this risk can be reduced.

[0067] The thickness of the protective film-forming film is not particularly limited, but is preferably 5 μm to 100 μm, 7 μm to 50 μm, 9 μm to 30 μm, 11 μm to 30 μm, 13 μm to 25 μm, or 14 μm to 24 μm.

[0068] By setting the thickness within the above range, the movement of the material in the protective film in the thickness direction is suppressed, and the required surface roughness Ra0 and Ra1 of the protective film are easily obtained. In addition, when performing the sealing process, it is not easy to produce adverse effects such as the displacement of the chip with the protective film due to the pressure of the flow of the sealing resin.

[0069] The thickness of the protective film-forming film refers to the thickness of the entire protective film-forming film. For example, the thickness of a protective film-forming film composed of multiple layers refers to the total thickness of all layers constituting the protective film-forming film.

[0070] The following describes a protective film formed on a chip as a workpiece. Figure 1 The chip 10 with a protective film shown will be described as a protective film formed by converting the protective film forming film of this embodiment into a protective film.

[0071] like Figure 1 As shown, the chip 10 with the protective film is on the back side of the chip 6a ( Figure 1 A protective film 1a is formed on the surface side of the chip 6a ( Figure 1 A convex electrode 6b is formed on the lower side (in the middle).

[0072] A circuit is formed on the surface of chip 6a, and convex electrodes 6b are formed to electrically connect to the circuit. While details will be discussed later, chip 10 with a protective film is positioned so that the surface on which convex electrodes 6b are formed faces the chip mounting substrate. Then, through a predetermined heat treatment (reflow soldering), the convex electrodes 6b are electrically and mechanically connected to the substrate for mounting. Examples of convex electrodes 6b include bumps and columnar electrodes.

[0073] (1.1 Surface roughness of protective film)

[0074] In this embodiment, Figure 1 After heating the protective film 1a at 260°C for 5 minutes, the surface S of the protective film 1a has a roughness of 200 nm or less. This surface roughness is expressed as the arithmetic average roughness Ra. In this embodiment, the surface roughness of the protective film 1a after heating at 260°C for 5 minutes is denoted as Ra1. In other words, Ra1 is 200 nm or less.

[0075] The heating process at 260°C for 5 minutes is assumed to be performed when mounting the chip 10 with the protective film on a chip mounting substrate. After this heating process, the chip 10 with the protective film is sometimes sealed with resin. For example, this sealing process is performed when manufacturing a system-in-package (SiP) in which multiple chips are sealed in a single package.

[0076] When the roughness Ra1 of the surface S of the protective film 1 a after heating at 260° C. for 5 minutes is 200 nm or less, the reliability of adhesion between the protective film and the sealing resin for sealing the chip 10 with the protective film is improved.

[0077] Although the reason for the improvement in bonding reliability is not yet clear, it is speculated as follows: the treatment of heating at 260°C for 5 minutes will affect the compatibility of the components contained in the protective film, and will also affect the fluidity of the components contained in the protective film. Therefore, the surface roughness of the protective film after heating at 260°C for 5 minutes will change compared to before heating. When the surface roughness Ra1 is greater than the above range, the surface of the protective film is not smooth, so the sealing resin cannot fully enter the unevenness of the protective film, and the protective film cannot be fully embedded in the sealing resin. As a result, a gap will be generated at the interface between the protective film and the sealing resin. Air or water will exist in the gap. If the package is heated in a state where there is a gap, the expansion of air or water vapor will cause the protective film and the sealing resin to peel off starting from the gap. Therefore, there is a tendency for the bonding reliability between the protective film and the sealing resin to decrease.

[0078] Furthermore, by setting the surface roughness Ra1 to 200 nm or less, the following effects can be expected.

[0079] WLCSPs and other packages have protruding electrodes, such as bumps, on the underside of the package, which connect to the substrate during mounting. Therefore, even with optical inspection from the protective film side, it's difficult to detect connection failures (such as disconnection or short circuits) with the substrate. Furthermore, while inspection using a transmission X-ray device can detect short circuits, it can't detect disconnections.

[0080] Therefore, to detect both types of connection failures, laminography and tomosynthesis, three-dimensional inspection methods using X-rays, can be used. With these X-ray inspection methods, the lower the surface roughness of the protective film irradiated by the X-rays, the more accurately connection failures can be detected. Therefore, from the perspective of detecting connection failures, a surface roughness Ra1 of 200 nm or less is also preferred.

[0081] The surface roughness Ra1 is preferably 150 nm or less, 125 nm or less, 100 nm or less, 80 nm or less, or 60 nm or less.

[0082] On the other hand, the surface roughness Ra1 is preferably 35 nm or more, 40 nm or more, or 45 nm or more. By setting the lower limit of Ra1 to the above value, the surface of the protective film is appropriately roughened, thereby achieving an anchoring effect for the sealing resin and easily achieving good adhesion reliability.

[0083] Furthermore, in this embodiment, the surface roughness of the surface S of the protective film 1a before being heated at 260°C for 5 minutes is preferably 35 nm or greater. This surface roughness is expressed as the arithmetic average roughness Ra. In this embodiment, the surface roughness of the surface S of the protective film 1a before being heated at 260°C for 5 minutes is denoted as Ra0. That is, Ra0 is preferably 35 nm or greater.

[0084] Ra0 is assumed to be the surface roughness of the protective film before the reflow process. The chip 10 with the protective film is placed on a predetermined terminal portion on the chip mounting substrate and then subjected to the reflow process. As a method for placing the chip 10 with the protective film on the chip mounting substrate, for example, there can be cited a method of using a suction nozzle to suck the chip 10 with the protective film stored on a tray, tape, etc., and detaching the chip 10 with the protective film from a predetermined position on the chip mounting substrate. In this method, the surface S of the protective film is sucked and detached by the suction nozzle. At this time, if the surface S of the protective film has a certain degree of roughness, it can be detached smoothly from the suction nozzle without causing positional offset, etc. Therefore, when Ra0 is within the above range, the chip 10 with the protective film will be reliably placed on the chip mounting substrate, and poor installation will be reduced.

[0085] The surface roughness Ra0 is preferably 35 nm or more, more preferably 40 nm or more, and even more preferably 45 nm or more.

[0086] (1.2 water contact angle)

[0087] In this embodiment, the water contact angle of the surface S of the protective film 1a after heating at 260°C for 5 minutes is preferably 107° or less. In other words, the protective film 1a preferably has high wettability after heating at 260°C for 5 minutes. A water contact angle of 107° or less on the surface S tends to improve the adhesion reliability between the protective film and the sealing resin.

[0088] The water contact angle is more preferably 105° or less, further preferably 102° or less, and particularly preferably 100° or less.

[0089] In addition, the water contact angle also changes with the surface roughness Ra1 and other surface conditions (polarity, etc.).

[0090] (1.3 Protective Film Forming Composition)

[0091] As long as the protective film has the above-mentioned physical properties, the composition of the protective film forming film is not particularly limited. In the present embodiment, the composition constituting the protective film forming film (protective film forming composition) is preferably a resin composition containing at least a polymer component (A), a curable component (B) and a filler (E). The polymer component can be regarded as a component formed by a polymerizable compound undergoing polymerization reaction. In addition, the curable component is a component that can undergo a curing (polymerization) reaction. In addition, in this specification, polymerization reaction also includes polycondensation.

[0092] In addition, the components contained in the polymer component may also be curable components. In this embodiment, when the protective film forming composition contains both components belonging to such a polymer component and a curable component, the protective film forming composition is considered to contain the polymer component and the curable component.

[0093] (1.3.1 Polymer composition)

[0094] The polymer component (A) not only makes the protective film-forming film have film-forming properties (film-forming properties), but also gives it appropriate viscosity, thereby ensuring that the protective film-forming film is uniformly attached to the workpiece. The weight average molecular weight of the polymer component is usually in the range of 50,000 to 2 million, preferably in the range of 100,000 to 1.5 million, and particularly preferably in the range of 200,000 to 1 million. If the weight average molecular weight is too small, when heated at 260°C, it is impossible to suppress the activity of the material in the protective film that makes the surface of the protective film rough. On the other hand, if the weight average molecular weight is too large, the compatibility with other components deteriorates, resulting in the formation of a uniform film. As such a polymer component, for example, acrylic resin, urethane resin, phenoxy resin, silicone resin, saturated polyester resin, etc. can be used, and acrylic resin is particularly preferably used.

[0095] In addition, in this specification, unless otherwise specified, the "weight average molecular weight" refers to a polystyrene-equivalent value measured by gel permeation chromatography (GPC).

[0096] Examples of acrylic resins include (meth)acrylate copolymers composed of structural units derived from (meth)acrylate monomers and (meth)acrylic acid derivatives. Preferred (meth)acrylate monomers are (meth)acrylic acid alkyl esters having an alkyl group with 1 to 18 carbon atoms, specifically methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, and butyl (meth)acrylate. Examples of (meth)acrylic acid derivatives include (meth)acrylic acid, glycidyl (meth)acrylate, and hydroxyethyl (meth)acrylate.

[0097] In this embodiment, glycidyl (meth)acrylate is preferably used to introduce glycidyl groups into the acrylic resin. Acrylic resins with glycidyl groups introduced improve compatibility with the epoxy resin (described later as a thermosetting component), increasing the glass transition temperature (Tg) of the protective film-forming film after curing and improving heat resistance. Furthermore, in this embodiment, hydroxyl groups are preferably introduced into the acrylic resin using hydroxyethyl acrylate or the like to control adhesion and workpiece adhesion properties.

[0098] The glass transition temperature of the acrylic resin is preferably -70°C to 40°C, -40°C to 36°C, -30°C to 32°C, -20°C to 28°C, -10°C to 24°C, or 1°C to 20°C. By setting the lower limit of the glass transition temperature of the acrylic resin to the above value, the fluidity of the protective film-forming film and the protective film during heating is suppressed, thereby facilitating control of the surface roughness of the protective film.

[0099] When an acrylic resin has m types of structural units (m is an integer greater than or equal to 2), the glass transition temperature of the acrylic resin can be calculated as follows. Specifically, the m types of monomers from which the structural units in the acrylic resin are derived are sequentially assigned non-repeating numbers from 1 to m and designated "monomer m." The glass transition temperature (Tg) of the acrylic resin can be calculated using the Fox equation shown below.

[0100] [Mathematical formula 1]

[0101]

[0102] Wherein, Tg is the glass transition temperature of the acrylic resin, m is an integer greater than or equal to 2, Tgk is the glass transition temperature of the homopolymer of monomer m, Wk is the mass fraction of the structural unit m derived from monomer m in the acrylic resin, and Wk satisfies the following formula.

[0103] [Mathematical formula 2]

[0104]

[0105] Wherein, m and Wk are the same as those described above.

[0106] As Tgk, the values ​​described in the Polymer Data Handbook, the Adhesion Handbook, or the Polymer Handbook can be used. For example, the Tgk of a homopolymer of methyl acrylate is 10°C, the Tgk of a homopolymer of n-butyl acrylate is -54°C, the Tgk of a homopolymer of methyl methacrylate is 105°C, the Tgk of a homopolymer of 2-hydroxyethyl acrylate is -15°C, the Tgk of a homopolymer of glycidyl methacrylate is 41°C, and the Tgk of 2-ethylhexyl acrylate is -70°C.

[0107] When the total weight of the protective film-forming composition is 100 parts by mass, the content of the polymer component is preferably 5 to 80 parts by mass, 6 to 50 parts by mass, 7 to 40 parts by mass, 8 to 35 parts by mass, 9 to 30 parts by mass, or 10 to 25 parts by mass. By setting the upper limit of the content of the polymer component to the above value, the content of components with high relative fluidity when heated at 260°C in the protective film-forming composition is reduced, thereby suppressing the movement of materials in the protective film that tend to roughen the surface when heated at 260°C.

[0108] (1.3.2 Thermosetting components)

[0109] The curable component (B) forms a hard protective film by curing the protective film-forming film. As the curable component, a thermosetting component, an energy ray curable component, or a mixture thereof can be used. When cured by irradiating energy rays, the protective film-forming film of this embodiment contains a filler described later, so the light transmittance decreases. Therefore, for example, when the thickness of the protective film-forming film is relatively thick, it is easy to make the energy ray curing insufficient.

[0110] On the other hand, even a relatively thick thermosetting protective film can be fully cured by heating, thereby forming a protective film with high protective performance and suppressing the movement of materials within the protective film, which tends to roughen the surface when heated at 260°C. Furthermore, by using conventional heating means such as a heating oven, multiple protective film-forming films can be heated and thermally cured simultaneously.

[0111] Therefore, in this embodiment, it is desirable that the curable component is thermosetting. In other words, the protective film-forming film of this embodiment is preferably thermosetting.

[0112] Whether a protective film-forming film is thermosetting can be determined as follows. First, a protective film-forming film at room temperature (23°C) is heated to a temperature higher than room temperature and then cooled to room temperature to form a heated and cooled protective film-forming film. Next, at the same temperature, the hardness of the heated and cooled protective film-forming film is compared with the hardness of the protective film-forming film before heating. If the heated and cooled protective film-forming film is harder, the protective film-forming film is determined to be thermosetting.

[0113] As the thermosetting component, for example, epoxy resin, polyimide resin, unsaturated polyester resin, and a mixture thereof are preferably used.

[0114] The epoxy resin as a thermosetting component has the property of being three-dimensionally reticulated and forming a strong film when heated. As such epoxy resin, various well-known epoxy resins can be used. In the present embodiment, the molecular weight (formula weight) of the epoxy resin is preferably 300 or more and less than 50,000, 300 or more and less than 10,000, 300 or more and less than 5,000, or 300 or more and less than 3,000. In addition, the epoxy equivalent of the epoxy resin is preferably 50 to 5,000 g / eq, more preferably 100 to 2,000 g / eq, and even more preferably 150 to 1,000 g / eq.

[0115] Specific examples of such epoxy resins include glycidyl ethers of phenols such as bisphenol A, bisphenol F, resorcinol, phenyl novolac, and cresol novolac; glycidyl ethers of alcohols such as butanediol, polyethylene glycol, and polypropylene glycol; glycidyl ethers of carboxylic acids such as phthalic acid, isophthalic acid, and tetrahydrophthalic acid; glycidyl or alkyl glycidyl epoxy resins in which the active hydrogen bonded to the nitrogen atom of aniline isocyanurate is substituted with a glycidyl group; and so-called alicyclic epoxides in which epoxy groups are introduced by, for example, oxidation of carbon-carbon double bonds in the molecule, such as vinylcyclohexane diepoxide, 3,4-epoxycyclohexylmethyl-3,4-dicyclohexanecarboxylate, and 2-(3,4-epoxy)cyclohexyl-5,5-spiro(3,4-epoxy)cyclohexane-m-dioxane. An epoxy resin having a biphenyl skeleton, a dicyclohexadiene skeleton, a naphthalene skeleton or the like may also be used.

[0116] Among them, bisphenol glycidyl epoxy resins, o-cresol novolac epoxy resins, and phenol novolac epoxy resins are preferably used. These epoxy resins may be used alone or in combination of two or more.

[0117] When a thermosetting component is used as the curing component (B), it is preferred to use a curing agent (C) as an auxiliary agent. As a curing agent for epoxy resin, a heat-activated latent epoxy resin curing agent is preferred. "Heat-activated latent epoxy resin curing agent" is a type of curing agent that is difficult to react with epoxy resin at room temperature (23°C), but is activated by heating to a certain temperature or above, thereby reacting with epoxy resin. Methods for activating heat-activated latent epoxy resin curing agents include a method of generating active species (anions, cations) in a chemical reaction based on heating; a method of stably dispersing in epoxy resin at around room temperature, but being compatible with epoxy resin, dissolving and initiating a curing reaction at high temperature; a method of dissolving a molecular sieve-encapsulated curing agent at high temperature and initiating a curing reaction; a method based on microcapsules, etc.

[0118] Among the methods exemplified above, a method in which the precipitant is stably dispersed in the epoxy resin at around room temperature but is compatible with and dissolved in the epoxy resin at high temperature to initiate a curing reaction is preferred.

[0119] Specific examples of heat-activated latent epoxy resin curing agents include various onium salts, dibasic acid dihydrazide compounds, dicyandiamide, amine adduct curing agents, and high-melting-point active hydrogen compounds of imidazole compounds. These heat-activated latent epoxy resin curing agents can be used alone or in combination of two or more. In this embodiment, dicyandiamide is particularly preferred.

[0120] In addition, as a curing agent for epoxy resin, phenol resin is also preferred. As the phenol resin, condensates of phenols such as alkylphenols, polyphenols, naphthols and aldehydes can be used without particular limitation. Specifically, phenol novolac resin, o-cresol novolac resin, p-cresol novolac resin, tert-butylphenol novolac resin, dicyclopentadiene cresol resin, poly-p-vinylphenol resin, bisphenol A novolac resin or modified products thereof can be used.

[0121] The phenolic hydroxyl groups contained in these phenol resins can easily undergo an addition reaction with the epoxy groups of the above-mentioned epoxy resins by heating, thereby forming a cured product having high impact resistance.

[0122] The content of the curing agent (C) is preferably 0.1 to 30 parts by mass, 1.0 to 25 parts by mass, 1.5 to 20 parts by mass, 2.0 to 18 parts by mass, 2.5 to 16 parts by mass, 3.0 to 14 parts by mass, or 3.5 to 12 parts by mass relative to 100 parts by mass of the epoxy resin. By setting the lower limit of the content of the curing agent (C) to the above value, the network structure of the protective film becomes dense, thereby suppressing the movement of materials in the protective film that tends to roughen the surface when heated at 260°C.

[0123] When dicyandiamide is used as the curing agent (C), it is preferred to use a curing accelerator (D) simultaneously. Preferred curing accelerators include imidazoles (imidazoles in which one or more hydrogen atoms are replaced by groups other than hydrogen atoms), such as 2-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, and 2-phenyl-4-methyl-5-hydroxymethylimidazole. Among these, 2-phenyl-4-methyl-5-hydroxymethylimidazole is particularly preferred.

[0124] The content of the curing accelerator is preferably 0.01 to 30 parts by mass, 0.1 to 25 parts by mass, 1.0 to 20 parts by mass, 1.5 to 18 parts by mass, 2.0 to 16 parts by mass, 2.5 to 14 parts by mass, or 3.0 to 12 parts by mass relative to 100 parts by mass of the epoxy resin. By setting the lower limit of the content of the curing accelerator (D) to the above value, the network structure of the protective film becomes dense, thereby suppressing the movement of materials in the protective film that tends to roughen the surface when heated at 260°C.

[0125] When the total weight of the protective film-forming composition is set to 100 parts by mass, the total content of the thermosetting component and the curing agent is preferably 5 to 80 parts by mass, 6 to 50 parts by mass, 7 to 40 parts by mass, 8 to 35 parts by mass, 9 to 30 parts by mass, or 10 to 25 parts by mass. If the thermosetting component and the curing agent are blended in such a ratio, moderate viscosity is exhibited before curing, and the attachment operation can be performed stably. In addition, by setting the lower limit of the total content of the thermosetting component and the curing agent to the above value, a protective film with excellent film strength can be obtained after curing, thereby suppressing the movement of the material in the protective film, which tends to roughen the surface when heated at 260°C.

[0126] (1.3.3 Energy ray curable component)

[0127] When the curable component is an energy ray-curable component, the energy ray-curable component is preferably uncured, preferably has adhesiveness, and more preferably is uncured and has adhesiveness.

[0128] The energy ray-curable component is a component that is cured by irradiation with energy rays, and is also a component for imparting film-forming properties and flexibility to the protective film-forming film.

[0129] As the energy-ray curable component, for example, a compound having an energy-ray curable group is preferable. Examples of such a compound include known compounds having an energy-ray curable group.

[0130] (1.3.4 Filling materials)

[0131] By including a filler (E) in the protective film-forming film, the protective film formed by converting the protective film-forming film into a protective film becomes easier to adjust the thermal expansion coefficient. By making the thermal expansion coefficient close to the thermal expansion coefficient of the workpiece or the sealing resin, the bonding reliability of the package obtained using the protective film-forming film is further improved. In addition, by including a filler (E) in the protective film-forming film, a hard protective film can be obtained, and the moisture absorption rate of the protective film can be further reduced, thereby further improving the bonding reliability of the package.

[0132] The filler (E) may be either an organic filler or an inorganic filler, but an inorganic filler is preferred from the viewpoint of shape stability at high temperatures up to 260°C.

[0133] Preferred inorganic fillers include powders of silica, alumina, talc, calcium carbonate, red iron oxide, silicon carbide, and boron nitride; spherical beads of these inorganic fillers; surface-modified products of these inorganic fillers; single-crystal fibers of these inorganic fillers; and glass fibers. Among these, silica and surface-modified silica are preferred. Surface-modified silica is preferably modified with a coupling agent. More preferably, it is surface-modified with a silane coupling agent.

[0134] The average particle size of the inorganic filler is preferably 0.06 to 10 μm, more preferably 0.1 to 10 μm, and even more preferably 0.3 to 9 μm.

[0135] By setting the lower limit of the average particle size of the inorganic filler to the above value, the handling performance of the protective film-forming composition is improved. This facilitates stable quality of the protective film-forming composition and the protective film-forming film, and also facilitates increasing the surface roughness Ra0 before heating at 260°C. Furthermore, by setting the upper limit of the average particle size of the inorganic filler to the above value, it is easy to reduce the surface roughness Ra1 after heating at 260°C.

[0136] In this specification, unless otherwise specified, the “average particle size” refers to a particle size (D50) at a cumulative value of 50% in a particle size distribution curve determined by a laser diffraction scattering method.

[0137] When the total weight of the protective film-forming composition is 100 parts by mass, the content of the inorganic filler is preferably 15 to 80 parts by mass, 30 to 76 parts by mass, 40 to 72 parts by mass, 45 to 68 parts by mass, or 50 to 66 parts by mass.

[0138] By setting the lower limit of the inorganic filler content to the above value, it is easier to achieve the desired surface roughness Ra0 of the protective film. Furthermore, because the protective film-forming composition contains a large amount of components that are less likely to change the particle shape when heated at 260°C, the movement of materials within the protective film, which tends to roughen the surface when heated at 260°C, can be suppressed. Furthermore, by setting the upper limit of the inorganic filler content to the above value, it is easier to achieve the desired surface roughness Ra0 of the protective film, which also affects the control of Ra1.

[0139] Furthermore, the protective film-forming film preferably contains two or more fillers. That is, the filler (E) preferably contains two or more fillers. "Containing two or more fillers" means that the film may contain two or more fillers of different materials or two or more fillers of different average particle sizes.

[0140] In this embodiment, it is preferred to include two or more fillers with different average particle sizes. By including fillers with different average particle sizes in the protective film-forming film, it is easier to arrange fillers with smaller average particle sizes between fillers with larger average particle sizes. As a result, while achieving the aforementioned effects, it is easier to control the surface roughness Ra of the protective film after heating at 260°C for 5 minutes within the aforementioned range. Furthermore, it is easier to control the water contact angle of the protective film after heating at 260°C for 5 minutes within the aforementioned range.

[0141] When two or more fillers with different average particle sizes are contained, the average particle size of the filler with the largest average particle size is preferably 1.5 to 100 times, more preferably 2 to 20 times, and even more preferably 3 to 18 times the average particle size of the filler with the smallest average particle size.

[0142] In addition, whether or not the protective film or protective film-forming film contains two or more fillers having different average particle sizes can be confirmed by observing a cross section of the protective film or protective film-forming film.

[0143] (1.3.5 Coupling agent)

[0144] The protective film-forming film preferably contains a coupling agent (F). By containing a coupling agent, the heat resistance of the protective film is not impaired after the protective film-forming film is cured, and the adhesion and tightness between the protective film and the workpiece can be improved. At the same time, the water resistance (resistance to moist heat) can also be improved. As a coupling agent, silane coupling agents are preferred from the perspectives of versatility and cost advantages, as well as from the perspective of controlling the water contact angle within the above range.

[0145] Examples of the silane coupling agent include γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, γ-(methacryloxypropyl)trimethoxysilane, γ-aminopropyltrimethoxysilane, N-6-(aminoethyl)-γ-aminopropyltrimethoxysilane, N-6-(aminoethyl)-γ-aminopropylmethyldiethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-ureidopropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropylmethyldimethoxysilane, bis(3-triethoxysilylpropyl)tetrasulfide, methyltrimethoxysilane, methyltriethoxysilane, vinyltrimethoxysilane, vinyltriacetoxysilane, and imidazolesilane. These silane coupling agents may be used alone or in combination of two or more.

[0146] (1.3.6 Colorants)

[0147] The protective film-forming film preferably contains a colorant (G). This shields the back of the workpiece such as a chip, thereby shielding various electromagnetic waves generated in electronic devices and reducing malfunctions of the workpiece such as a chip.

[0148] As the colorant (G), known colorants such as inorganic pigments, organic pigments, and organic dyes can be used. In the present embodiment, inorganic pigments are preferred.

[0149] As inorganic pigment, for example, carbon black, cobalt pigment, iron pigment, chromium pigment, titanium pigment, vanadium pigment, zirconium pigment, molybdenum pigment, ruthenium pigment, platinum pigment, ITO (indium tin oxide) pigment, ATO (antimony tin oxide) pigment etc. can be listed.Wherein, particularly preferably use carbon black.Through carbon black, it is possible to shield electromagnetic waves of wider wavelength range.

[0150] The amount of colorant (especially carbon black) added to the protective film-forming film varies depending on the thickness of the protective film-forming film, but for example, when the thickness of the protective film-forming film is 20 μm, it is preferably 0.05 to 10 mass%, 0.1 to 7 mass%, or 0.5 to % by mass relative to the total mass of the protective film-forming film.

[0151] The average particle size of the colorant (especially carbon black) is preferably 1 to 500 nm, particularly preferably 3 to 100 nm, and further preferably 5 to 50 nm. When the average particle size of the colorant is within the above range, it is easy to control the light transmittance within the desired range.

[0152] (1.3.7 Other additives)

[0153] The protective film-forming film composition may contain other additives such as a photopolymerization initiator, a crosslinking agent, a plasticizer, an antistatic agent, an antioxidant, a gettering agent, and a thickener, as long as the effects of the present invention are not impaired.

[0154] (2. Sheet for forming protective film)

[0155] Before use, the protective film-forming film may be protected on one or both sides by a release film and rolled up and stored in the form of a protective film-forming sheet. The release film is peeled off when the protective film-forming film is used.

[0156] The composition of the release film is arbitrary; examples include plastic films that inherently release the protective film-forming film, and films obtained by subjecting the plastic film to a release treatment using a release agent or the like. Specific examples of plastic films include polyester films such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate, and polyolefin films such as polypropylene and polyethylene. Silicones, fluorine-based compounds, and long-chain alkyl-based compounds can be used as release agents, with silicones being preferred due to their low cost and stable performance. The thickness of the release film is not particularly limited, but is typically approximately 20 to 250 μm.

[0157] When release films are provided on both sides of the protective film-forming film, it is preferred that one release film has a larger release force to form a heavy release film, and the other release film has a smaller release force to form a light release film.

[0158] (3. Composite Sheet for Protective Film Formation)

[0159] Figure 2 : is a schematic cross-sectional view of an example of a composite sheet for forming a protective film according to this embodiment. Figure 2 As shown, the composite sheet 3 for forming a protective film of this embodiment includes: an adhesive sheet 4 formed by laminating an adhesive layer 42 on one surface of a base material 41; a protective film-forming film 1 laminated on the adhesive layer 42 side of the adhesive sheet 4; and a jig adhesive layer 5 laminated on the peripheral portion of the protective film-forming film 1 on the side opposite to the adhesive sheet 4. The jig adhesive layer 5 is a layer for bonding the composite sheet 3 for forming a protective film to a jig such as a ring frame.

[0160] The protective film-forming composite sheet 3 of this embodiment is attached to a workpiece during machining to support the workpiece and simultaneously transforms the protective film-forming film 1 into a protective film, thereby forming a protective film on the workpiece or a product derived therefrom. This protective film may be an uncured protective film-forming film 1, but is preferably composed of a cured protective film-forming film 1.

[0161] The protective film forming composite sheet 3 of the present embodiment is used to support a wafer as a workpiece during dicing and simultaneously form a protective film on chips as processed products obtained by dicing, but is not limited thereto.

[0162] (3.1 Adhesive Sheet)

[0163] The adhesive sheet 4 of the protective film forming composite sheet 3 of this embodiment includes a base material 41 and an adhesive layer 42 laminated on one surface of the base material 41. Therefore, as described above, the adhesive sheet serves as a support sheet for supporting the protective film forming film.

[0164] (3.1.1. Base material)

[0165] The base material 41 of the adhesive sheet 4 is not particularly limited in its constituent material as long as it is a sheet suitable for workpiece processing, such as wafer dicing and expansion, and is generally composed of a film mainly composed of a resin material (hereinafter referred to as "resin film").

[0166] Specific examples of resin films include polyethylene films such as low-density polyethylene (LDPE) film, linear low-density polyethylene (LLDPE) film, and high-density polyethylene (HDPE) film; polyolefin films such as polypropylene film, polybutene film, polybutadiene film, polymethylpentene film, ethylene-norbornene copolymer film, and norbornene resin film; ethylene copolymer films such as ethylene-vinyl acetate copolymer film, ethylene-(meth)acrylic acid copolymer film, and ethylene-(meth)acrylate copolymer film; polyvinyl chloride films such as polyvinyl chloride film and vinyl chloride copolymer film; polyester films such as polyethylene terephthalate film and polybutylene terephthalate film; polyurethane film; polyimide film; polystyrene film; polycarbonate film; and fluororesin film. Modified films such as cross-linked films and ionomer films of these films may also be used. The substrate 41 may be a film composed of one of these films, or a laminated film obtained by combining two or more of these films.

[0167] Among the above films, polyolefin films are preferred from the perspectives of environmental safety, cost, etc., and polypropylene films with excellent heat resistance are particularly preferred. If a polypropylene film is used, the expansion adaptability of the adhesive sheet 41 or the pick-up adaptability of processed products such as chips will not be impaired, and the substrate 41 can be given heat resistance. Due to the heat resistance of the substrate 41, even when the protective film-forming composite sheet 3 is attached to the workpiece and the protective film-forming film 1 is thermally cured, the adhesive sheet 4 can be prevented from loosening. In addition, despite the presence of an adhesive layer, the surface roughness Ra0 of the protective film is easily controlled, which is also related to the control of Ra1.

[0168] In order to improve the adhesion between the resin film and the adhesive layer 42 laminated on the surface thereof, one or both sides of the resin film may be subjected to a surface treatment using an oxidation method or a embossing method, or a primer treatment, as needed. Examples of the oxidation method include corona discharge treatment, plasma discharge treatment, chromium oxidation treatment (wet type), flame treatment, hot air treatment, ozone, and ultraviolet irradiation treatment. Examples of the embossing method include sandblasting and thermal spraying.

[0169] Regarding the base material 41 , the resin film may contain various additives such as a colorant, a flame retardant, a plasticizer, an antistatic agent, a lubricant, and a filler.

[0170] The thickness of the substrate 41 is not particularly limited as long as it can appropriately function in each step using the protective-film-forming composite sheet 3 , but is preferably in the range of 20 to 450 μm, more preferably 25 to 400 μm, and particularly preferably 50 to 350 μm.

[0171] (3.1.2. Adhesive layer)

[0172] The adhesive layer 42 of the adhesive sheet 4 of the composite sheet 3 for forming the protective film of the present embodiment can be composed of a non-energy ray curing adhesive or an energy ray curing adhesive. As the non-energy ray curing adhesive, an adhesive having the required adhesion and re-peelability is preferred, for example, an acrylic adhesive, a rubber adhesive, a silicone adhesive, a urethane adhesive, a polyester adhesive, a polyvinyl ether adhesive, etc. can be used. Among them, an acrylic adhesive that has high adhesion to the protective film forming film 1 and can effectively suppress the workpiece or the workpiece processed product from falling off during the cutting process is preferred. In addition, from the perspective of being easy to control Ra0 and easy to control the pick-up adaptability of the workpiece processed product with the protective film, an acrylic adhesive is also preferred.

[0173] On the other hand, since the adhesive strength of the energy ray-curable adhesive is reduced by irradiation with energy rays, when the workpiece or a processed product thereof needs to be separated from the adhesive sheet 4 , irradiation with energy rays facilitates separation.

[0174] The energy-curable adhesive constituting the adhesive layer 42 may contain an energy-curable polymer as a main component, or a mixture of a non-energy-curable polymer and an energy-curable monomer and / or oligomer as a main component.

[0175] Examples of energy-curable polymers include (meth)acrylate (copolymer) polymers into which energy-curable groups are introduced. Examples of energy-curable monomers and / or oligomers include esters of polyols and (meth)acrylic acid. In addition to containing energy-curable components, energy-curable adhesives may also contain additives such as photopolymerization initiators and crosslinking agents.

[0176] The thickness of the adhesive layer 42 is not particularly limited as long as it can appropriately function in each process using the protective film-forming composite sheet 3. Specifically, the thickness of the adhesive layer is preferably 1-50 μm, 2-30 μm, 2-20 μm, 3-10 μm, or 3-8 μm.

[0177] By setting the upper limit of the thickness of the adhesive layer to the above value, the movement of the protective film-forming film in contact with the adhesive layer can be controlled, thereby easily obtaining the desired surface roughness Ra0 of the protective film, which also affects the control of Ra1.

[0178] The adhesive constituting the jig adhesive layer 5 is preferably an adhesive having the desired adhesive strength and removability. For example, acrylic adhesives, rubber adhesives, silicone adhesives, urethane adhesives, polyester adhesives, polyvinyl ether adhesives, etc. can be used. Of these, acrylic adhesives are preferred because they have high adhesion to jigs such as annular frames and can effectively prevent the protective film-forming composite sheet 3 from peeling off from the annular frame during the cutting process. Alternatively, a base material serving as a core material may be inserted in the thickness direction of the jig adhesive layer 5.

[0179] From the viewpoint of adhesion to a jig such as a ring frame, the thickness of the jig adhesive layer 5 is preferably 5 to 200 μm, particularly preferably 10 to 100 μm.

[0180] (4. Method for producing protective film-forming film)

[0181] The manufacturing method of the protective film forming film is not particularly limited. The film can be manufactured using the above-mentioned protective film forming composition, or a composition (coating agent) obtained by diluting the protective film forming composition with a solvent. The coating agent can be prepared by mixing the components constituting the protective film forming composition by a known method. When preparing the coating agent, it is preferred that the stirred coating agent be filtered through a sieve with a mesh of 160 μm or less. Thus, the respective agglomerates of filler, curing agent, resin, etc. are removed, and as a result, Ra0 and Ra1 of the protective film are easily controlled.

[0182] The resulting coating agent is applied to the release surface of a release film using a coating machine such as a roll coater, knife coater, roll knife coater, air knife coater, die coater, rod coater, gravure coater, or curtain coater, and dried to form a protective film-forming film on the first release film. Subsequently, the release surface of a second release film is bonded to the exposed surface of the protective film-forming film, thereby obtaining a protective film-forming sheet comprising the protective film-forming film 1 sandwiched between the two release films.

[0183] When attaching the second release film, it is preferably done while heating to a temperature higher than room temperature (23°C). Although this is done before the protective film is formed, the arrangement of the fillers on the surface and interior near the surface of the protective film-forming film in contact with the first release film, and on the surface and interior near the surface of the protective film-forming film in contact with the second release film, can be controlled, and Ra0 and Ra1 can also be controlled.

[0184] (5. Method for Manufacturing Composite Sheet for Forming Protective Film)

[0185] The method for producing the protective film-forming composite sheet 3 is not particularly limited. For example, a first laminate including the protective film-forming film 1 and a second laminate including the adhesive sheet 4 as a support sheet are separately produced, and then the protective film-forming film 1 and the adhesive sheet 4 are laminated using the first and second laminates.

[0186] The first laminate can be produced by the same method as the protective film-forming sheet described above: that is, a protective film-forming film is formed on the release surface of the first release film, and the release surface of the second release film is bonded to the exposed surface of the protective film-forming film.

[0187] The first laminate can be half-cut as needed to form the protective film-forming film 1 and the second release film into a desired shape, such as a circle, etc. In this case, excess portions of the protective film-forming film 1 and the second release film caused by half-cutting can be appropriately removed.

[0188] On the other hand, in order to manufacture the second laminate, first, an adhesive composition constituting the adhesive layer 42, or a composition (coating agent) obtained by diluting the adhesive composition with a solvent, is prepared. Next, the coating agent is applied to the release surface of the third release film and dried to form the adhesive layer 42 on the third release film. Then, a substrate 41 is attached to the exposed surface of the adhesive layer 42 to obtain a laminate (second laminate) consisting of the adhesive sheet 4 and the third release film, wherein the adhesive sheet 4 is composed of the substrate 41 and the adhesive layer 42.

[0189] Here, when the adhesive layer 42 is composed of an energy-ray-curable adhesive, the adhesive layer 42 may be cured by irradiating the adhesive layer 42 with energy rays at this stage, or the adhesive layer 42 may be cured after being laminated with the protective film-forming film 1. In addition, when the adhesive layer 42 is cured after being laminated with the protective film-forming film 1, the adhesive layer 42 may be cured before the cutting step or after the cutting step.

[0190] As energy rays, ultraviolet rays, electron beams, etc. can be generally used. The irradiation dose of energy rays varies depending on the type of energy rays. For example, when ultraviolet rays are used, the irradiation dose is preferably 50 to 1000 mJ / cm 2 , particularly preferably 100 to 500 mJ / cm 2 When an electron beam is used, the preferred range is 10 to 1000 krad.

[0191] After obtaining the first and second laminates in this manner, the second release film of the first laminate is peeled off, and the third release film of the second laminate is simultaneously peeled off. The exposed protective film-forming film 1 of the first laminate is then bonded to the exposed adhesive layer 42 of the adhesive sheet 4 of the second laminate. The adhesive sheet 4 can be cut as needed to form a desired shape, such as a circular shape having a diameter greater than that of the protective film-forming film 1. In this case, any excess portion of the adhesive sheet 4 resulting from the cutting can be appropriately removed. Alternatively, the protective film-forming film and the adhesive layer 42 can be formed into circular shapes having the same diameter.

[0192] Thus, a composite sheet 3 for forming a protective film is obtained, which is composed of an adhesive sheet 4 formed by laminating an adhesive layer 42 on a substrate 41, a protective film-forming film 1 laminated on the adhesive layer 42 side of the adhesive sheet 4, and a first release film laminated on the side of the protective film-forming film 1 opposite to the adhesive sheet 4. If necessary, after peeling off the first release film, an adhesive layer 5 for a jig can be formed on the periphery of the exposed protective film-forming film 1 or adhesive layer 42.

[0193] (6. Method for manufacturing the device)

[0194] As an example of a method for manufacturing a device using a protective film forming film according to this embodiment, a method for manufacturing a package in which a chip with a protective film is arranged on a substrate. The chip with a protective film is obtained by processing a wafer with a protective film formed thereon.

[0195] The method for manufacturing the device of the present embodiment includes at least the following steps 1 to 5.

[0196] Step 1: A step of attaching the protective film-forming film of the protective film-forming composite sheet to the back surface of the wafer;

[0197] Step 2: a step of forming the attached protective film into a protective film;

[0198] Step 3: Singulating the wafer having the protective film or protective film-forming film on the back surface to obtain a plurality of chips having the protective film or protective film-forming film;

[0199] Step 4: a step of placing a chip with a protective film or a protective film-forming film on a substrate;

[0200] Step 5: A step of heating the chip with the protective film and the substrate placed on the substrate.

[0201] In addition, as is clear from the above description, step 2 may be performed before step 3 and step 4, after step 3 and before step 4, or after step 3 and step 4.

[0202] Furthermore, in this embodiment, the method for manufacturing the device preferably includes, after step 5, a step of covering the exposed portion of the protective film of the chip with the protective film with a sealing member (step 6). By performing step 6, a package in which a plurality of chips, including the chip with the protective film, are sealed can be obtained as a sealed device.

[0203] use Figures 4 to 9 A method for manufacturing the device having the above-mentioned steps 1 to 6 will be described.

[0204] like Figure 4 As shown, the protective film forming film 1 of the protective film forming composite sheet 3 is attached to the wafer 6 (process 1). At this time, the outer periphery of the protective film forming film 1 can be fixed by a ring frame 7. In this embodiment, as shown in FIG. Figure 4 As shown, since the jig adhesive layer 5 is provided on the outer periphery of the protective film-forming film 1, the jig adhesive layer 5 is attached to the annular frame 7. The wafer 6 is attached to the surface of the protective film-forming film 1 opposite to the surface to which the adhesive layer 42 is attached. When attaching the protective film-forming film 1 to the wafer 6, the protective film-forming film 1 may be heated as needed to activate its adhesive properties.

[0205] The attached protective film-forming film 1 is then subjected to a protective film-forming process to form a protective film (step 2), thereby obtaining a wafer 6 with a protective film. If the protective film-forming film 1 is thermosetting, the protective film-forming film 1 can be heated at a predetermined temperature for an appropriate period of time. Alternatively, if the protective film-forming film 1 is energy-ray curable, energy rays can be irradiated from the adhesive sheet 4 side.

[0206] Furthermore, the protective film forming film 1 may be cured after the dicing step, or the protective film forming film may be cured after the chip with the protective film forming film is picked up from the adhesive sheet.

[0207] Next, the wafer 6 with the protective film is cut by a known method, such as Figure 5 As shown in FIG. 1 , a chip having a protective film 1a (a chip with a protective film 10) is obtained (process 3). Then, as shown in FIG. Figure 6 As shown, the adhesive sheet 4 is expanded in the planar direction as needed, and the chip 10 with the protective film is picked up from the adhesive sheet 4 by the suction nozzle C.

[0208] The picked-up chip 10 with a protective film may be transported to the next process, or may be temporarily stored on a tray, tape, etc., and transported to the next process after a predetermined time.

[0209] The chip 10 with the protective film is transported to the next process, such as Figure 7 As shown, it is transported to the substrate 50 by the suction nozzle C, and the terminal portion on the substrate is detached from the suction nozzle C and arranged at a position where it can connect the connection electrode such as the bump and the terminal portion such as the pad (process 4). At this time, if the surface roughness of the protective film is too small, problems may occur when it is detached from the suction nozzle, resulting in connection failure after the heating treatment. Therefore, as mentioned above, the surface roughness Ra0 of the protective film before the heat treatment is preferably 35nm or more. In addition, as Figure 8 As shown, in this embodiment, another chip 11 different from the chip 10 with a protective film may be mounted on the substrate 50. Therefore, a plurality of chips are mounted on the substrate.

[0210] The chip with the protective film placed at a predetermined position on the substrate is subjected to a heat treatment (reflow treatment) (step 5). The reflow treatment conditions are preferably, for example, a maximum heating temperature of 180 to 350° C. and a reflow treatment time of 2 to 10 minutes.

[0211] During the reflow process, the protruding electrodes 6b of the chip 10 with protective film melt, electrically and mechanically connecting to the terminal portion on the substrate, and the chip 10 with protective film is mounted on the substrate. Next, in this embodiment, the chips 10 with protective film are sealed by covering the multiple chips mounted on the substrate with a sealing member (step 6). The sealing member can also be filled between the multiple chips.

[0212] The method of sealing multiple chips using the sealing member 30 is not particularly limited. The following method can be used: multiple chips after reflow treatment are placed in a mold, a sealing resin material with fluidity is injected into the mold, and the sealing resin material is heated and cured to form a sealing resin layer. In addition, a method of placing a sheet of sealing resin in a manner covering multiple chips and heating and curing the sealing resin to form a sealing resin layer can also be used. As the material of the sealing member, for example, epoxy resin can be listed. In addition, since the sealing resin is cured by heating, the "sealing resin" in this specification includes both sealing resins that are in contact with the protective film before curing and sealing resins that are in contact with the protective film after curing.

[0213] After this sealing process, the system-level package 100 ( Figure 9 At this time, since the surface roughness Ra1 of the protective film after heating at 260°C for 5 minutes is within the above range, the surface roughness of the protective film is low even after reflow processing, and the adhesion reliability of the interface between the protective film and the sealing resin is good. Therefore, a highly reliable system-level package can be obtained.

[0214] As another example of a method for manufacturing a device using a protective film-forming film according to the present embodiment, a method for manufacturing a device in which a chip with a protective film is arranged on a substrate is described, wherein the chip with a protective film is obtained by marking a protective film or a protective film-forming film formed on the chip.

[0215] The manufacturing method of this device is the same as the manufacturing method of the above device, and includes at least steps 1 to 5, and a step (step 7) of laser marking the protective film or protective film-forming film so that the height of the mark portion is greater than 0 μm.

[0216] Step 7 may be performed after step 2 and before step 5. In this embodiment, step 7 is preferably performed before steps 3 and 4.

[0217] By performing laser marking, chips with protective film formation films or chips with protective films can be identified from the time after laser marking until placement on a substrate.

[0218] Laser marking can also be performed by removing the surface of the protective film-forming film or protective film using laser irradiation. However, in this embodiment, it is preferred to mark the surface so that the height of the marked portion (laser-irradiated portion) is greater than 0 μm. In other words, the marked portion is preferably formed to be convex compared to the unmarked portion. The protective film-forming film or protective film in the marked portion increases in volume due to laser irradiation, thereby forming a convex mark.

[0219] The height of the marking portion is preferably 0.001 μm or more, 0.005 μm or more, 0.010 μm or more, 0.020 μm or more, or 0.030 μm or more. When the height of the marking portion is greater than 0 μm, the visibility of the printed text is better than that of 0 μm.

[0220] The manufacturing method of this device is the same as the manufacturing method of the above-mentioned device, and preferably includes a step (step 6) of covering the exposed portion of the protective film of the chip with the protective film with a sealing member after step 5. By performing step 6, a package in which multiple chips including the chip with the protective film are sealed can be obtained.

[0221] Furthermore, when the marking portion is concave (removed) by laser irradiation, the marking becomes clearer than when it is convex, and remains clear even after reflow. However, when sealing a chip with a protective film having a concave marking portion, voids are likely to form in the concave portion, resulting in reduced adhesion reliability between the sealing resin and the protective film. Therefore, by making the marking portion height greater than 0 μm, adhesion reliability can be improved.

[0222] The manufacturing method of the device can also be performed by using Figures 4 to 9 The laser marking process can be performed using a known laser marking device.

[0223] (7. Modification)

[0224] Figure 3 : is a cross-sectional view of a composite sheet for forming a protective film according to another embodiment of the present invention. Figure 3 As shown, the protective film-forming composite sheet 3A of this embodiment comprises an adhesive sheet 4 formed by laminating an adhesive layer 42 on one surface of a substrate 41, and a protective film-forming film 1 laminated on the adhesive layer 42 side of the adhesive sheet 4. The protective film-forming film 1 of this embodiment is formed to be approximately the same size as the workpiece or slightly larger than the workpiece, and smaller than the adhesive sheet 4, when viewed from above. The portion of the adhesive layer 42 not laminated with the protective film-forming film 1 can be attached to a jig such as a ring frame.

[0225] Furthermore, a jig adhesive layer similar to the jig adhesive layer 5 of the protective film forming composite sheet 3 may be separately provided around the adhesive layer 42 of the adhesive sheet 4 of the protective film forming composite sheet 3A.

[0226] Furthermore, in order to protect the protective film-forming film before use, a release film may be laminated on the surface of the protective film-forming composite sheet 3 or 3A on the protective film-forming film 1 side.

[0227] As mentioned above, although embodiment of this invention was demonstrated, this invention is not limited to the said embodiment, It can also be modified in various aspects within the scope of this invention.

[0228] Example

[0229] Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples.

[0230] (Test 1)

[0231] (Manufacture of Protective Film-Forming Sheet)

[0232] The following components were mixed at the blending ratios (based on solid content) shown in Table 1, and diluted with methyl ethyl ketone to a solid content concentration of 50% by mass to prepare a coating agent. The coating agent was stirred and then filtered through a polyester mesh with a mesh size of 75 μm.

[0233] (A) Polymer component

[0234] (A-1) A (meth)acrylate copolymer (weight average molecular weight: 500,000, glass transition temperature: -28°C) prepared by copolymerization of 55 parts by mass of n-butyl acrylate, 10 parts by mass of methyl acrylate, 20 parts by mass of glycidyl methacrylate, and 15 parts by mass of 2-hydroxyethyl acrylate.

[0235] (A-2) A (meth)acrylate copolymer (weight average molecular weight: 500,000, glass transition temperature: 5° C.) prepared by copolymerizing 3 parts by mass of n-butyl acrylate, 88 parts by mass of methyl acrylate, and 9 parts by mass of 2-hydroxyethyl acrylate.

[0236] (A-3) A (meth)acrylate copolymer (weight average molecular weight: 400,000, glass transition temperature: 5° C.) prepared by copolymerizing 3 parts by mass of n-butyl acrylate, 75 parts by mass of methyl acrylate, 7 parts by mass of glycidyl methacrylate, and 15 parts by mass of 2-hydroxyethyl acrylate.

[0237] (B) Curable component (thermosetting component)

[0238] (B-1) Bisphenol A epoxy resin (manufactured by MITSUBISH CHEMICAL CORPORATION, jER828, epoxy equivalent 184 to 194 g / eq)

[0239] (B-2) Bisphenol A epoxy resin (manufactured by MITSUBISH CHEMICAL CORPORATION, jER1055, epoxy equivalent 800 to 900 g / eq)

[0240] (B-3) Dicyclopentadiene-type epoxy resin (manufactured by Dainippon Inki Chemical Industries, Ltd., EPICLON HP-7200HH, epoxy equivalent 255-260 g / eq)

[0241] (B-4) Cresol novolac type epoxy resin (manufactured by Nippon Kayaku Co., Ltd., EOCN-104, epoxy equivalent 220 g / eq)

[0242] (B-5) Epoxy resin with a flexible skeleton (manufactured by Dainippon Inki Chemical Industries, Ltd., EXA4850-150, molecular weight 900, epoxy equivalent 450 g / eq)

[0243] (C) Curing agent: dicyandiamide (manufactured by MITSUBISH CHEMICAL CORPORATION, DICY7)

[0244] (D) Curing accelerator: 2-phenyl-4,5-dihydroxymethylimidazole (manufactured by SHIKOKU CHEMICALS CORPORATION, CUREZOL 2PHZ)

[0245] (E) Filling material

[0246] (E-1) Epoxy-modified spherical silica filler (manufactured by ADMATECHS CORPORATION, SC2050MA, average particle size 0.5 μm)

[0247] (E-2) Silica filler (manufactured by Tokuyama Corporation, UF310, average particle size 3 μm)

[0248] (E-3) Amorphous silica filler (manufactured by TATSUMORI CORPORATION, SV-10, average particle size 8 μm)

[0249] (F) Silane coupling agent: γ-glycidoxypropyltrimethoxymethylsilane (manufactured by Shin-Etsu Chemical Co., Ltd., KBM403, methoxy equivalent 12.7 mol / g, molecular weight 236.3)

[0250] (G) Colorant: Carbon black (manufactured by MITSUBISH CHEMICAL CORPORATION, MA600, average particle size 20 nm)

[0251] [Table 1]

[0252]

[0253] The prepared coating agent was applied to a first release film (manufactured by LINTEC CORPORATION: SP-PET501031, thickness: 50 μm) and dried at 100°C for 2 minutes to form a 20 μm thick protective film-forming film. Next, a second release film (manufactured by LINTEC CORPORATION: SP-PET381031, thickness: 38 μm) was attached to the protective film-forming film to produce a protective film-forming sheet having release films formed on both sides of the protective film-forming film. The attachment conditions were a temperature of 60°C, a pressure of 0.6 MPa, and a speed of 1 m / min.

[0254] (Manufacturing of adhesive sheets)

[0255] The following components were mixed at the blending ratios (based on solid content) shown below and diluted with methyl ethyl ketone to a solid content concentration of 25% by mass to prepare an adhesive layer coating agent. The coating agent contained 100 parts by mass of an acrylic polymer copolymerized from 70 parts by mass of 2-ethylhexyl acrylate (2EHA), 20 parts by mass of methyl methacrylate (MMA), and 10 parts by mass of 2-hydroxyethyl acrylate (HEA), and 40 parts by mass of trifunctional xylylenediisocyanate (Takenate D110N, manufactured by MITSUI TAKEDA CHEMICALS, INC.).

[0256] The prepared coating agent was applied to a third release film (SP-PET381031 manufactured by LINTEC CORPORATION, thickness: 38 μm) and dried at 100°C for 2 minutes to form a 5 μm thick adhesive layer. Next, the glossy surface of an 80 μm thick polypropylene film (manufactured by GUNZE LIMITED, glossy on one side and matte on the other side) was attached to the adhesive layer to form an adhesive sheet.

[0257] (Manufacturing of Composite Sheet for Protective Film Formation)

[0258] Using the protective film forming sheet, adhesive sheet, and clamp adhesive layer formed on the peeling film in a shape corresponding to the outer periphery of the protective film forming film obtained above, composite sheets for forming protective film are obtained, wherein a protective film forming film is formed on the adhesive sheet and a clamp adhesive layer is formed on the outer periphery of the protective film forming film.

[0259] The following measurements and evaluations were performed using the obtained composite sheet for forming a protective film.

[0260] First, the first release film was peeled off from the composite sheets for forming protective films of Examples 1 to 7 and Comparative Example 1, and the protective film-forming films of the composite sheets for forming protective films of Examples 1 to 7 and Comparative Example 1 were attached to the polished surface of a #2000 polished silicon mirror wafer (diameter 150 mm, thickness 75 μm) using a film attaching machine ("Adwill RAD2500" manufactured by LINTEC CORPORATION) to obtain the following: Figure 4 The structure shown.

[0261] The silicon mirror wafer with the protective film-forming film attached thereto was heated in an oven under an air atmosphere at 130° C. for 2 hours to convert the protective film-forming film into a protective film, thereby producing a wafer with a protective film.

[0262] (Surface roughness of protective film)

[0263] The adhesive sheet was peeled off from the wafer with the protective film, and the arithmetic mean roughness Ra0 (μm) of the protective film surface was measured using an SV-3000 manufactured by Mitsutoyo Corporation. The measurement conditions were in accordance with JIS B0601:2013, with a critical value λc = 0.8 mm and an evaluation length In = 10 mm. The results are shown in Table 2.

[0264] Next, the adhesive sheet was peeled off from the wafer with the protective film, placed in an oven, heated at 260°C for 5 minutes, removed from the oven, and gradually cooled. After gradually cooling to room temperature (23°C), the arithmetic mean roughness Ra1 (μm) of the surface of the protective film was measured using an SV-3000 manufactured by MITSUTOYO CORP CORPORATION. The measurement conditions were based on JIS B0601:2013, with a critical value λc = 0.8 mm and an evaluation length In = 10 mm. The results are shown in Table 2.

[0265] (Water contact angle on protective film surface)

[0266] The adhesive sheet was peeled off from the wafer with the protective film, placed in an oven, heated at 260°C for 5 minutes, removed from the oven, and gradually cooled. After gradually cooling to room temperature (23°C), the surface of the protective film was measured. At 23°C and a relative humidity of 50%, an automatic contact angle meter ("DSA100" manufactured by KRUSS CORPORATION) was used to measure the contact angle obtained by a 2μl water droplet, and this was used as the water contact angle. The results of the water contact angle measurement are shown in Table 2.

[0267] (Evaluation of Adhesion Reliability of Semiconductor Packages)

[0268] For wafers with protective films, a dicing die bonding sheet is attached to the surface opposite the polished surface with the protective film via a film adhesive and then secured to the wafer dicing ring frame. The film adhesive used should have sufficient bonding reliability to prevent separation between the substrate and silicon chip during an adhesion reliability test using a package structure that does not use a protective film (i.e., a "substrate / film adhesive / silicon chip / sealing resin" structure).

[0269] Next, the dicing die bond sheet and the silicon wafer with the protective film were cut into a size of 8 mm×8 mm using a dicing device (“DFD651” manufactured by DISCO Corporation) to obtain semiconductor chips with protective films.

[0270] Next, a rubber suction nozzle is used to pick up the semiconductor chip with a protective film and the film adhesive of the dicing die bonding sheet from the substrate. As a substrate, a circuit pattern is formed on the copper foil (thickness 18μm) of a copper-clad laminate ("CCL-HL830" manufactured by MITSUBISHI GAS CHEMICAL Co., Inc.) and a solder resist ("SPR-4000AUS303" manufactured by TAIYO INK MFG.CO., LTD.) is stacked on the circuit pattern ("LN001E-001PCB (Au) AUS303" manufactured by CHINO GIKENCORPORATION). Using a die-bonding device (BESTEM-D02 manufactured by CANON MACHINERY INC.), the semiconductor chip with a protective film is pressed onto the substrate through the film adhesive at 120°C, 2.45N (250gf), and 0.5 seconds. After the pressure bonding, the laminate of the substrate and the semiconductor chip with the protective film was subjected to IR reflow under the conditions of a maximum heating temperature of 260° C. and a heating time of 5 minutes.

[0271] Next, each of these stacked bodies was sealed with a sealing resin ("KE-G125" manufactured by KYOCERA CHEMICAL CORPORATION) to a sealing thickness of 400 μm, and heated at 175°C for 5 hours to cure the sealing resin. The sealed stacked bodies were then attached to a dicing tape ("Adwill D-510T" manufactured by LINTEC CORPORATION) and cut into 15 mm × 15 mm pieces using a dicing device ("DFD651" manufactured by DISCO Corporation). This yielded a semiconductor package in which a semiconductor chip with a protective film was sealed with resin, for evaluation of adhesion reliability.

[0272] The resulting semiconductor package was then left at 85°C and 60% relative humidity for 168 hours to allow it to absorb moisture. It was then subjected to IR reflow at a maximum temperature of 260°C for 5 minutes. The semiconductor package that had undergone IR reflow was then inspected for cracks using a scanning ultrasonic flaw detector ("Hye-Focus" manufactured by HITACHI KENKI FINE TECH CO., LTD.).

[0273] This evaluation was performed on every ten semiconductor packages of each Example and Comparative Example. Adhesion reliability was evaluated by determining the number of package cracks present in each of the ten packages. This number is reported in the "Adhesion Reliability Test" column of Table 2 below. In Table 2, for example, "0 / 10" indicates that ten semiconductor packages were evaluated and zero package cracks were observed, meaning no semiconductor packages were observed to have package cracks. Samples with five or more cracks were rated "Poor (F)," samples with two to four cracks were rated "Fair (B)," and samples with zero or one crack were rated "Good (A)."

[0274] [Table 2]

[0275]

[0276] Table 2 confirms that when the surface roughness Ra1 of the protective film after heating at 260°C for 5 minutes is within the above range, the package bonding reliability is good. Furthermore, even for samples with similar Ra1 (Examples 1 and 7), the sample with a lower water contact angle (Example 1), while slightly higher, still demonstrates excellent bonding reliability.

[0277] Furthermore, Table 2 shows that using two fillers with different average particle sizes tends to minimize the change in Ra [nm] before and after heating. This also confirms that the surface roughness Ra1 of the protective film after heating at 260°C for 5 minutes tends to fall within the above range.

[0278] Furthermore, in the process of placing the semiconductor chip with the protective film on the substrate, the protective films of all the examples and comparative examples could be smoothly removed from the rubber nozzle. This is presumably because Ra0 was within the above range.

[0279] (Test 2)

[0280] A semiconductor package including a semiconductor chip with a protective film sealed with resin was prepared in the same manner as in Example 1 except that the protective film-forming composite sheet of Example 5 was used and the protective film was laser marked. The same adhesion reliability evaluation as in Test 1 was performed.

[0281] (Laser marking)

[0282] After the protective film-forming film was formed into a protective film, a laser marking device ("CSM300M" manufactured by EO Technics Co., Ltd.) was used to irradiate the protective film from the adhesive sheet side of the wafer with the protective film composite sheet, thereby laser marking the surface of the protective film. The irradiation conditions were: laser wavelength: 532nm, draw speed: 20mm / s, power: 0.11W and 0.14W. In addition, three lines of "888" (a total of nine characters) were marked on each chip, with each character measuring 0.5mm in length and 0.4mm in width.

[0283] Next, the adhesive sheet was peeled off from the laser-marked wafer with the protective film, and the height of the center of the character "8" was measured using a laser microscope (Keyence Corporation "VK-9700") according to the following procedure. The measurement was performed on the wafer with the protective film before heating at 260°C.

[0284] First, specify a measurement position (a straight line) on the protective film surface, spanning unprinted area / printed area / unprinted area. Next, measure the average height of the unprinted area on both sides over a 10 μm measurement distance. Add the two values ​​and divide by 2 to record this as the "Average Height of Unprinted Area [μm]." Next, measure the average height of the printed area over a 10 μm measurement distance and record this as the "Average Height of Printed Area [μm]." Calculate the printed area height from this value using the following formula.

[0285] Height of printed part [μm] = (average height of printed part) - (average height of unprinted part)

[0286] The above measurement is performed on four characters at the four corners of the nine characters, and the average height of the four characters is recorded as the height of the final printed part.

[0287] Following the measurement, the wafer with the protective film was heated at 260°C for 5 minutes and diced in the same manner as in Test 1 to obtain semiconductor chips with the protective film. Using the obtained semiconductor chips with the protective film, a semiconductor package in which the semiconductor chips with the protective film were sealed with resin was obtained in the same manner as in Test 1. The resulting semiconductor package was evaluated for adhesion reliability in the same manner as in Test 1.

[0288] When the power during laser marking was 0.11 W, the height of the printed portion was 0.019 μm, the printed characters were recognizable, and a result of "0 / 10" (judgment A) was obtained in the adhesion reliability test.

[0289] When the power during laser marking was 0.14 W, the height of the printed portion was 0.038 μm, the printed characters were recognizable, and a result of "0 / 10" (judgment A) was obtained in the adhesion reliability test.

[0290] It is presumed that even if laser marking is performed, the height of the marked portion is greater than 0 μm, so the printed characters can be recognized and no adverse effect is exerted on the bonding reliability.

[0291] In addition, if the laser-marked wafer with a protective film is heated to 260°C, the printed information visible to the naked eye will tend to become less clear than before heating. However, when sealing is performed, this does not cause a major problem because the marked part is covered by the sealing resin.

[0292] Industrial Applicability

[0293] The protective film-forming film and the protective film-forming composite sheet of the present invention are suitable for use in producing a package encapsulating a chip with a protective film.

Claims

1. A protective film-forming film for forming a protective film, wherein: The protective film-forming composition constituting the protective film-forming film contains a polymer component including an acrylic resin, a thermosetting component, and a filler. The protective film is a thermally cured product. The surface roughness Ra1 of the protective film after heating at 260° C. for 5 minutes is 200 nm or less. The water contact angle of the protective film after heating at 260° C. for 5 minutes was 107° or less.

2. The protective film-forming film according to claim 1, wherein The surface roughness Ra0 of the protective film before heating at 260° C. for 5 minutes was 35 nm or more.

3. The protective film-forming film according to claim 1 or 2, wherein The filler material is composed of two or more filler materials with different average particle sizes. 4 . A composite sheet for forming a protective film, comprising the protective film-forming film according to claim 1 laminated on a support sheet.

5. A method for manufacturing a semiconductor device, comprising: a step of attaching the protective film-forming film according to any one of claims 1 to 3 or the protective film-forming film included in the composite sheet for forming a protective film according to claim 4 to the back surface of a workpiece; The process of thermally curing the attached protective film-forming film; The step of singulating the workpiece having the protective film or protective film-forming film on the back surface to obtain a plurality of workpieces with the protective film or protective film-forming film; a step of placing the workpiece having the protective film or protective film-forming film on a substrate; and A step of heating the workpiece with the protective film disposed on a substrate and the substrate.

6. A method for manufacturing a semiconductor device, comprising: a step of attaching the protective film-forming film according to any one of claims 1 to 3 or the protective film-forming film included in the composite sheet for forming a protective film according to claim 4 to the back surface of a workpiece; The process of thermally curing the attached protective film-forming film; a step of laser marking the protective film or the protective film-forming film so that the height of the marked portion is greater than 0 μm; The step of singulating the workpiece having the protective film or protective film-forming film on the back surface to obtain a plurality of workpieces with the protective film or protective film-forming film; a step of placing the workpiece having the protective film or protective film-forming film on a substrate; and A step of heating the workpiece with the protective film disposed on a substrate and the substrate.

7. The method for manufacturing a semiconductor device according to claim 5 or 6, wherein: After the step of heating the workpiece with the protective film and the substrate disposed on the substrate, there is a step of covering the exposed portion of the workpiece with the protective film with a sealing member.

8. The method for manufacturing a semiconductor device according to claim 5 or 6, wherein: The workpiece is a wafer, and the processed product of the workpiece is a chip.

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