Protection film forming film and method for manufacturing work product with protection film

Abstract

To provide a protection film forming film for forming a protection film in a work product with a protection film, the work product with a protection film comprising a work product and a protection film provided at any portion thereof, the protection film forming film being capable of forming a protection film having a high light reflectance to make the work product with a protection film less noticeable on a white substrate, and being capable of applying thin-colored printing with good visibility to the protection film.SOLUTION: There is provided a protection film forming film 13 for forming a protection film in any portion of a work product obtained by processing a work, wherein when the protection film forming film 13 is curable, a cured product of the protection film forming film 13 has a light reflectance over an entire wavelength region of 420 to 700 nm exceeding 55%, and when the protection film forming film 13 is non-curable, the protection film forming film 13 has a light reflectance over the entire wavelength region of 420 to 700 nm exceeding 55%.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a protective film-forming film and a method for manufacturing a workpiece with a protective film. [Background technology]

[0002] Some wafers, such as semiconductor wafers and insulator wafers, have circuits formed on one surface (circuit surface) and also have protruding electrodes such as bumps on that surface (circuit surface). Such wafers are divided into chips, and the protruding electrodes are connected to connection pads on a circuit board, thereby mounting the chips on the circuit board. In such wafers and chips, the surface opposite to the circuit surface (back surface) may be protected with a protective film to prevent damage such as cracks. Furthermore, in the manufacturing process of a semiconductor device, a semiconductor device panel, which will be described later, is used as a workpiece, and in order to prevent warping or cracks from occurring in this panel, some part of the panel may be protected with a protective film.

[0003] In such a case, for example, a protective film-forming film for forming a protective film is attached to a desired location on the workpiece, such as the back surface of a wafer, and then the workpiece is processed to produce a workpiece, and the protective film-forming film is cured as necessary, and the protective film-forming film or the protective film is cut to produce a workpiece with a protective film, which includes the workpiece and a protective film provided at any location on the workpiece. An example of a workpiece with a protective film is a semiconductor chip with a protective film, which includes a semiconductor chip and a protective film provided on its back surface.

[0004] White substrates are sometimes used as circuit boards for light-emitting devices. In such cases, it is preferable to use a protective film with high light reflectance so that the workpiece with the protective film is less noticeable on the white substrate. As protective film-forming films capable of forming such protective films, there have been disclosed protective film-forming films that are curable and have a reflectance of 20% or more for light in the entire wavelength range of 400 to 700 nm, and non-curable protective film-forming films that have a reflectance of 20% or more for light in the entire wavelength range of 400 to 700 nm (see Patent Document 1). This non-curable protective film-forming film itself functions as a protective film. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2023-043538 Summary of the Invention [Problem to be solved by the invention]

[0006] Typically, the protective film in a protective film-coated workpiece is printed for identification. When the protective film-coated film is curable, printing can be performed on the cured product of the protective film-coated film (i.e., the protective film), or on the protective film-coated film before curing. However, when printing is performed on a protective film with high light reflectance, if the printing color is dark, such as black, the protective film-coated workpiece may stand out on a white substrate due to the printing. On the other hand, if the printing color is changed to a light color, such as gray, to solve this problem, the protective film-coated workpiece will not stand out on a white substrate, but the visibility of the printing itself will be reduced. In contrast, the protective film-coated film disclosed in Patent Document 1 does not address these problems, and it is unclear whether it can solve these problems.

[0007] The present invention aims to provide a protective film-forming film for forming a protective film in a protective film-equipped workpiece comprising a workpiece and a protective film provided at any location on the workpiece, and which can apply light-colored printing with good visibility to the protective film even if the protective film has a high light reflectance to make the protective film-equipped workpiece less noticeable on a white substrate. [Means for solving the problem]

[0008] In order to solve the above problems, the present invention employs the following configuration. [1] A protective film-forming film for forming a protective film at any location on a workpiece obtained by processing a workpiece, wherein, when the protective film-forming film is curable, the cured product of the protective film-forming film has a reflectance of more than 55% for light in the entire wavelength range of 420 to 700 nm, and when the protective film-forming film is non-curable, the protective film-forming film has a reflectance of more than 55% for light in the entire wavelength range of 420 to 700 nm. [2] The protective film-forming film according to [1], wherein, when the protective film-forming film is curable, the cured product of the protective film-forming film has a transmittance of 40% or less for light in the entire wavelength range of 420 to 700 nm, and when the protective film-forming film is non-curable, the protective film-forming film has a transmittance of 40% or less for light in the entire wavelength range of 420 to 700 nm. [3] The protective film-forming film according to [1] or [2], wherein the protective film-forming film contains a white pigment. [4] A protective film-forming film according to any one of [1] to [3], wherein, when the protective film-forming film is curable, the difference between the maximum and minimum values ​​of reflectance of the cured product of the protective film-forming film in the wavelength range of 420 to 700 nm is 20% or less, and when the protective film-forming film is non-curable, the difference between the maximum and minimum values ​​of reflectance of the protective film-forming film in the wavelength range of 420 to 700 nm is 20% or less.

[0009] [5] One side of the protective film-forming film is attached to the ground surface of the silicon wafer, and a copper foil having a width of 10 mm is attached to the other side of the protective film-forming film after attachment, thereby producing a laminate of the silicon wafer, the protective film-forming film, and the copper foil. If the protective film-forming film is curable, the protective film-forming film in the laminate is cured to form a cured product, and the cured product is then applied to the silicon wafer together with the copper foil in the length direction of the copper foil in an environment of a temperature of 23°C and a relative humidity of 50% so that the surfaces of the cured product and the silicon wafer that were in contact with each other form an angle of 90°. The protective film-forming film according to any one of [1] to [4], wherein the peel strength of the cured product measured when peeled from the silicon wafer is 7000 mN / 10 mm or more, and when the protective film-forming film is non-curable, the peel strength of the protective film-forming film measured when peeled from the silicon wafer together with the copper foil in the length direction of the copper foil so that the surfaces of the protective film and the silicon wafer that were in contact with each other form an angle of 90° in an environment of 23°C and 50% relative humidity is 7000 mN / 10 mm or more.

[0010] [6] A method for manufacturing a workpiece with a protective film using a protective film-forming film described in any one of [1] to [5], wherein if the protective film-forming film is curable, the cured product of the protective film-forming film is the protective film, and if the protective film-forming film is non-curable, the protective film after being attached to the workpiece is the protective film, and the manufacturing method includes an attachment process for attaching the protective film-forming film to the workpiece, a printing process for printing on the protective film-forming film or protective film after the attachment process, a processing process for processing the workpiece to produce the workpiece, and a cutting process for cutting the protective film-forming film or protective film after the attachment process, and if the protective film-forming film is curable, further includes a curing process for forming the protective film by curing the protective film-forming film after the attachment process. [7] A method for manufacturing a workpiece with a protective film according to [6], wherein in the printing step, a light-colored print is performed on the protective film-forming film or the protective film. [Effects of the Invention]

[0011] According to the present invention, there is provided a protective film forming film for forming a protective film in a protective film-equipped workpiece comprising a workpiece and a protective film provided at any location on the workpiece, and which is capable of applying light-colored printing with good visibility to the protective film even if the protective film has a high light reflectivity to make the protective film-equipped workpiece less noticeable on a white substrate. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a cross-sectional view schematically illustrating an example of a protective film-forming film according to an embodiment of the present invention. [Figure 2] 1 is a cross-sectional view schematically showing an example of a composite sheet for forming a protective film provided with a protective film-forming film according to one embodiment of the present invention. [Figure 3] 1A to 1C are cross-sectional views for schematically explaining an example of a method for manufacturing a semiconductor chip with a protective film, as an embodiment of a method for manufacturing a workpiece with a protective film according to an embodiment of the present invention. [Figure 4] 10A to 10C are cross-sectional views for schematically explaining another example of a method for manufacturing a semiconductor chip with a protective film, as an embodiment of a method for manufacturing a workpiece with a protective film according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0013] ◇Protective film forming film A protective film-forming film according to one embodiment of the present invention is a protective film-forming film for forming a protective film at any location on a workpiece obtained by processing a workpiece, and when the protective film-forming film is curable, the cured product of the protective film-forming film has a reflectance of more than 55% for light in the entire wavelength range of 420 to 700 nm, and when the protective film-forming film is non-curable, the protective film-forming film has a reflectance of more than 55% for light in the entire wavelength range of 420 to 700 nm. The protective film-forming film of this embodiment can be laminated with a support sheet to form a composite sheet for forming a protective film, as will be described later, for example.

[0014] The protective film-forming film of this embodiment is attached to any location on the workpiece, and ultimately forms a protective film, thereby making it possible to protect the processed workpiece. The protective film-forming film of this embodiment is soft and can be attached to a workpiece before it is processed into a workpiece. That is, by using the protective film-forming film of this embodiment or a composite sheet for forming a protective film including the same, it is possible to manufacture a workpiece with a protective film, which includes a workpiece and a protective film provided at any location on the workpiece. Then, prior to manufacturing the workpiece with a protective film, it is possible to manufacture a workpiece with a protective film-forming film, which includes a workpiece and the protective film-forming film provided at any location on the workpiece, by using the protective film-forming film.

[0015] In this embodiment, the workpiece is obtained by machining a workpiece. Examples of the workpiece include a wafer and a semiconductor device panel.

[0016] Examples of the wafer include semiconductor wafers made of elemental semiconductors such as silicon, germanium, and selenium, and compound semiconductors such as GaAs, GaP, InP, CdTe, ZnSe, and SiC; and insulating wafers made of insulators such as sapphire and glass. For example, if the workpiece is a semiconductor wafer, the workpiece artifact may be a semiconductor chip. One surface of these wafers is a circuit surface on which circuits are formed, and the opposite surface is referred to as the "back surface" in this specification. The same applies to chips produced by dividing a wafer by means of dicing or the like, and the surface opposite to the circuit surface on which the circuits of the chip are formed is called the "back surface." Both the circuit surface of the wafer and the circuit surface of the chip are provided with protruding electrodes such as bumps and pillars.

[0017] The semiconductor device panel is handled during the manufacturing process of a semiconductor device, and a specific example thereof is a panel that uses a semiconductor device in which one or more electronic components are sealed with sealing resin, and is configured by arranging multiple such semiconductor devices in a plane within an area of ​​a circular, rectangular, or other shape.

[0018] The workpiece is preferably a chip (e.g., a semiconductor chip) mounted on a substrate device, and may be a chip in a light-emitting device, such as a wafer-level chip-scale package (WLCSP) for current control. The light-emitting device may be any device equipped with a light-emitting element such as an LED (Light Emitting Diode), and its type is not particularly limited. Examples of the light-emitting device include a substrate device having a surface-mounted LED package equipped with a light-emitting element, a substrate device equipped with a mini LED element, and a substrate device equipped with a micro LED element.

[0019] In this specification, the term "substrate device" refers to a workpiece with a protective film, which is flip-chip connected to connection pads on a circuit board via protruding electrodes on its circuit surface. For example, if a semiconductor wafer is used as the workpiece, the substrate device may be a semiconductor device equipped with a semiconductor chip with a protective film.

[0020] Circuit boards in light-emitting devices often have a high visible light reflectance and are white in color. For example, a typical white circuit board has a light reflectance of 30% or more over the entire wavelength range of 420 to 700 nm. In contrast, the protective film obtained using the protective film-forming film of this embodiment has a high reflectance of visible light, and the protective film is preferably white. Therefore, as will be described later, a workpiece having such a protective film does not stand out on a white substrate (circuit board) in a light-emitting device, and the design of the device having the workpiece having the protective film is high.

[0021] The protective film-forming film of the present embodiment may be curable or non-curable. That is, the protective film-forming film may function as a protective film by being cured, or may function as a protective film in an uncured state. The curable protective film-forming film may be either thermosetting or energy ray-curable, or may have both thermosetting and energy ray-curable properties.

[0022] In this specification, the term "energy ray" refers to an electromagnetic wave or a charged particle beam that has an energy quantum. Examples of energy rays include ultraviolet rays, radioactive rays, and electron beams. In this specification, "energy ray curable" means a property of being cured by irradiation with energy rays, and "non-energy ray curable" means a property of not being cured even when irradiated with energy rays. In this specification, "non-curable" means a property that does not cure by any means such as heating, irradiation with energy rays, etc. A non-curable protective film-forming film can be considered to be a protective film after it is provided (formed) on a target object.

[0023] <<Reflectance of light (420~700nm)>> When the protective film-forming film of the present embodiment is curable, the cured product of the protective film-forming film has a reflectance of more than 55% for light in the entire wavelength range of 420 to 700 nm. In other words, the minimum reflectance of the cured product of the protective film-forming film for light in the wavelength range of 420 to 700 nm is higher than 55%. When the protective film-forming film of this embodiment is non-curable, the reflectance of the protective film-forming film for light in the entire wavelength range of 420 to 700 nm is greater than 55%, in other words, the minimum reflectance of the protective film-forming film for light in the wavelength range of 420 to 700 nm is higher than 55%. In this specification, "light in the entire wavelength range of 420 to 700 nm" may be referred to as "light (420 to 700 nm)."

[0024] In a protective film obtained using a protective film-forming film having the above-mentioned light (420 to 700 nm) reflectance characteristics, absorption of visible light is suppressed, and the protective film is preferably white. Therefore, a protective film-equipped workpiece having such a protective film does not stand out on a white substrate in a light-emitting device, and the design of the device including the protective film-equipped workpiece is high. Furthermore, even if a protective film has a high light reflectance to make the protective film-equipped workpiece less noticeable on a white substrate, the protective film obtained using a protective film-forming film having the above-mentioned light (420 to 700 nm) reflectance characteristics provides good visibility of the print even when a light-colored print is applied.

[0025] That is, in this embodiment, the workpiece is preferably a chip in a light-emitting device, and may be a semiconductor chip in a light-emitting device.

[0026] In this specification, unless otherwise specified, the cured product of the protective film-forming film means a cured product with a sufficiently high degree of curing, and is synonymous with the protective film.

[0027] As described later in the Examples, the reflectance of light (420 to 700 nm) can be measured by measuring the amount of total reflected light for each of the protective film-forming film or its cured product and a barium sulfate reference plate, and determining the ratio of the measured value for the protective film-forming film or its cured product to the measured value for the reference plate (i.e., relative total light reflectance).The maximum and minimum values ​​among these can be used as the maximum and minimum values ​​of the reflectance of light (420 to 700 nm) described later, respectively.

[0028] The reflectance of light (420 to 700 nm) may be greater than 55%, and may be, for example, greater than 60%, greater than 66%, greater than 72%, or greater than 80%. The higher the reflectance of light (420 to 700 nm), the greater the visibility of light-colored printing on the protective film. The upper limit of the reflectance of light (420 to 700 nm) is not particularly limited. For example, a protective film-forming film having a reflectance of light (420 to 700 nm) of 90% or less can be easily realized. In other words, the maximum reflectance of light (420 to 700 nm) may be 90% or less.

[0029] It is preferable that the reflectance of the uncured protective film-forming film itself for light in the entire wavelength range of 420 to 700 nm is in the same range as the reflectance of the above-mentioned light (420 to 700 nm) (for example, greater than 55%).

[0030] In the protective film-forming film and its cured product, the reflectance of light (420 to 700 nm) can be adjusted, for example, by adjusting the type and content of the components contained in the protective film-forming film. In particular, the protective film-forming film contains a colorant (colorant (J) in a thermosetting protective film-forming film, and a colorant in an energy ray-curable protective film-forming film and a non-curable protective film-forming film) described below, and the reflectance of the protective film-forming film and its cured product at light (420 to 700 nm) can be adjusted by adjusting the type and content of the colorant in the protective film-forming film. When the colorant is a pigment, the reflectance of the protective film-forming film and its cured product at light (420 to 700 nm) can also be adjusted by its particle size. For example, by using a colorant with high whiteness in the protective film and increasing its content, the reflectance of the protective film-forming film and its cured product at light (420 to 700 nm) can be increased. For example, when the protective film-forming film contains a white pigment, the reflectance of the protective film-forming film and its cured product to light (420 to 700 nm) can be more easily increased. That is, the protective film-forming film of the present embodiment preferably contains a white pigment. The white pigment will be described in detail later.

[0031] When the protective film-forming film contains a white pigment, the content of the white pigment in the protective film-forming film relative to the total mass of the protective film-forming film is preferably more than 7 mass%, more preferably more than 10 mass%, and may be, for example, any one of more than 15 mass%, more than 20 mass%, more than 30 mass%, and more than 40 mass%. When the content is in this range, the reflectance of the protective film-forming film and its cured product to light (420 to 700 nm) can be further increased. Furthermore, the visibility of light-colored printing on the protective film is further improved. On the other hand, in terms of improving the film-forming properties, flexibility, toughness, spreadability, etc. of the protective film-forming film, the ratio is preferably 60% by mass or less. The content of the white pigment in the protective film-forming film may be adjusted appropriately depending on the type of the protective film-forming film.

[0032] <<The difference between the maximum and minimum reflectance values ​​of light (420-700nm)>> When the protective film-forming film of the present embodiment is curable, the difference between the maximum and minimum values ​​of the reflectance of light (420 to 700 nm) of the cured product of the protective film-forming film is preferably 20% or less. When the protective film-forming film of the present embodiment is non-curable, the difference between the maximum and minimum values ​​of the reflectance of the protective film-forming film for light (420 to 700 nm) is preferably 20% or less. The smaller the difference, the more likely it is that the reflectance is neither high nor low in only a specific narrow wavelength range, which means that it is less likely to appear bluish-white, reddish-white, etc., and therefore the protective film has a better ability to make the workpiece with the protective film less noticeable on a white substrate.

[0033] In order to enhance the above-mentioned effect, regardless of whether the protective film-forming film is curable or not, it is more preferable that the difference between the maximum and minimum values ​​of the reflectance of light (420 to 700 nm) is 16% or less, and may be, for example, any of 13% or less, 10% or less, and 8% or less. The lower limit of the difference is not particularly limited. For example, a protective film-forming film having a difference of 3% or more can be easily realized. In one embodiment, the difference may be, for example, any one of 3 to 16%, 3 to 13%, 3 to 10%, and 3 to 8%, although these are just examples of the difference.

[0034] It is preferable that the difference between the maximum and minimum values ​​of the reflectance of the uncured protective film-forming film itself for light in the wavelength range of 420 to 700 nm is in the same range as the difference between the maximum and minimum values ​​of the reflectance of the above-mentioned light (420 to 700 nm) (for example, 20% or less).

[0035] <<Light (420~700nm) transmittance>> When the protective film-forming film of the present embodiment is curable, the transmittance of light (420 to 700 nm) of the cured product of the protective film-forming film is preferably 40% or less. When the protective film-forming film of the present embodiment is non-curable, the transmittance of the protective film-forming film to light (420 to 700 nm) is preferably 40% or less. The lower the transmittance, the less influence the components (usually the workpiece) that are in contact with the protective film in the workpiece with a protective film have on the color of the protective film when the workpiece with a protective film is viewed from the protective film side, and the more the protective film can be seen in a color that is closer to its inherent color.

[0036] In order to further enhance the above-mentioned effects, the transmittance of light (420 to 700 nm) may be, for example, any one of 32% or less, 26% or less, and 20% or less, regardless of whether the protective film-forming film is curable or not. The lower limit of the transmittance of light (420 to 700 nm) is not particularly limited. For example, a protective film-forming film having a transmittance of light (420 to 700 nm) of 10% or more can be easily realized. In one embodiment, the transmittance of light (420 to 700 nm) may be, for example, any one of 10 to 40%, 10 to 32%, 10 to 26%, and 10 to 20%, although these are just examples of the transmittance of light (420 to 700 nm).

[0037] In the protective film-forming film and its cured product, the transmittance of light (420 to 700 nm) can be adjusted, for example, by adjusting the type and content of the components contained in the protective film-forming film. In particular, if the protective film-forming film contains a colorant (colorant (J) in the thermosetting protective film-forming film, and the colorant in the energy ray-curable protective film-forming film and the non-curable protective film-forming film) described below, and the type and content of the colorant in the protective film-forming film are adjusted, the transmittance of light (420 to 700 nm) of the protective film-forming film and its cured product can be more easily adjusted.

[0038] <<Color tone on both sides of protective film>> It is preferable that the color tone of at least both sides of the protective film-forming film of this embodiment is uniform, and the color tone of the entire protective film-forming film may be uniform. Such a protective film-forming film is advantageous in that the printing can be clearly confirmed visually in the final state of the protective film to which printing has been applied. Furthermore, such a protective film-forming film is advantageous in that it is easy to manufacture and that the color tone of all protective film-coated workpieces produced from a single protective film-coated workpiece is uniform. Both surfaces of the protective film-forming film are, for example, the same as the first and second surfaces described below.

[0039] In this specification, the phrase "both surfaces of the protective film-forming film have a single color tone" means that both surfaces of the protective film-forming film have a single color tone (the same color) throughout their entire area. In this specification, the term "the first and second sides of the protective film-forming film have a single color tone" means that when the light reflectance of the first side of the protective film-forming film is measured at wavelengths of 1 nm each over the entire wavelength range of 420 to 700 nm, the light reflectance at a wavelength of x nm (x is any integer between 420 and 700) is defined as light reflectance R1(x), and the light reflectance of the second side of the protective film measured in the same manner is defined as light reflectance R2(x), and the difference in light reflectance for each wavelength is calculated using the formula: R1(x)-R2(x), the maximum absolute value of all the differences in light reflectance is less than 1.5%. In this specification, the phrase "the entire color tone of the protective film-forming film is uniform" means that not only the entire area on both sides of the protective film-forming film, but also the entire interior area has a single color tone (the color is the same).

[0040] The color tone of the protective film-forming film can be adjusted, for example, by adjusting the type and content of the components contained in the protective film-forming film. In particular, the color tone of the protective film-forming film can be more easily adjusted by adjusting the type and content of the colorant contained in the protective film-forming film.

[0041] <<Peel strength of protective film-forming film or its cured product>> When one side of the protective film-forming film of this embodiment is attached to the ground surface of a silicon wafer, and a copper foil having a width of 10 mm is attached to the other side of the protective film-forming film after attachment to produce a laminate of the silicon wafer, the protective film-forming film, and the copper foil, the peel strength of the protective film-forming film or its cured product measured using the laminate is preferably as follows: That is, when the protective film-forming film is curable, the protective film-forming film in the laminate is cured to form a cured product, and the cured product is peeled off from the silicon wafer together with the copper foil in the length direction of the copper foil so that the surfaces of the cured product and the silicon wafer that were in contact with each other form a 90° angle in an environment of 23°C and 50% relative humidity (so-called 90° peeling) and the peel strength of the cured product measured is preferably 7000 mN / 10 mm or more. When the protective film-forming film is non-curable, it is preferable that the peel strength of the protective film-forming film measured when the protective film-forming film is peeled off from the silicon wafer together with the copper foil in the length direction of the copper foil so that the surfaces of the protective film-forming film and the silicon wafer that were in contact with each other form an angle of 90° in an environment of a temperature of 23°C and a relative humidity of 50% is 7000 mN / 10 mm or more. The greater the peel strength, the greater the effect of suppressing unintended peeling of the protective film from the workpiece.

[0042] In order to further enhance the above-mentioned effect, the peel strength of the protective film-forming film or its cured product may be any one of 9000 mN / 10 mm or more, 10000 mN / 10 mm or more, 11000 mN / 10 mm or more, and 12000 mN / 10 mm or more. The upper limit of the peel strength is not particularly limited. For example, a protective film-forming film having a peel strength of 17,000 mN / 10 mm or less can be easily realized.

[0043] The peel strength of the protective film-forming film and its cured product can be adjusted, for example, by adjusting the type and content of the components contained in the protective film-forming film. In particular, if the protective film-forming film contains a filler (E) described later and the type and content of the filler (E) in the protective film-forming film are adjusted, the peel strength of the protective film-forming film and its cured product can be more easily adjusted.

[0044] When the protective film-forming film is thermosetting, the cured product of the protective film-forming film that defines the reflectance of light (420 to 700 nm), the transmittance of light (420 to 700 nm), and the peel strength is a thermosetting product, and is the protective film, which is a cured product obtained by heating the protective film-forming film at 140°C for 2 hours. When the protective film-forming film is energy ray-curable, the cured product of the protective film-forming film, which defines the reflectance of the light (420 to 700 nm), the transmittance of the light (420 to 700 nm), and the peel strength, is an energy ray-cured product, and the protective film is an energy ray-cured product, and the protective film is irradiated with an illuminance of 220 mW / cm 2 , energy ray dose 600mJ / cm 2 The cured product is obtained by irradiating the resin with energy rays under the conditions described above.

[0045] The protective film-forming film may be composed of one layer (single layer) or two or more layers. When the protective film-forming film is composed of multiple layers, these multiple layers may be the same or different from each other, and the combination of these multiple layers is not particularly limited.

[0046] In this specification, not only in the case of a protective film-forming film, "multiple layers may be the same or different from each other" means "all layers may be the same, all layers may be different, or only some layers may be the same," and further, "multiple layers are different from each other" means "at least one of the constituent materials and thicknesses of each layer is different from each other."

[0047] The thickness of the protective film-forming film is preferably less than 50 μm, more preferably 45 μm or less. By making the thickness of the protective film-forming film equal to or less than the upper limit, the thickness of the protective film-coated workpiece can be reduced, and various devices such as light-emitting devices equipped with the protective film-coated workpiece can be made thinner. The lower limit of the thickness of the protective film-forming film is not particularly limited. For example, the thickness of the protective film-forming film is preferably 10 μm or more in order to enhance the protective effect of the protective film. Here, the "thickness of the protective film-forming film" means the thickness of the entire protective film-forming film, and for example, the thickness of a protective film-forming film consisting of multiple layers means the total thickness of all layers constituting the protective film-forming film. This also applies to other layers such as the substrate and pressure-sensitive adhesive layer described below.

[0048] In this specification, not only in the case of protective film-forming films, but unless otherwise specified, "thickness" refers to a value expressed as the average of thicknesses measured at five randomly selected points on the object, and can be obtained using a constant pressure thickness measuring device in accordance with JIS K7130.

[0049] <<Composition for forming protective film>> The protective film-forming film can be formed using a protective film-forming composition containing its constituent materials. For example, the protective film-forming film can be formed by applying the protective film-forming composition to the surface to be formed and drying it as necessary. The ratio of the contents of the components that do not vaporize at room temperature in the protective film-forming composition is usually the same as the ratio of the contents of the components in the protective film-forming film. In this specification, "room temperature" means a temperature that is not particularly cooled or heated, that is, an ordinary temperature, and examples thereof include a temperature of 18 to 28°C.

[0050] In the protective film-forming film, the ratio of the total content of one or more components contained in the protective film, which will be described later, to the total mass of the protective film-forming film is 100 mass % or less. Similarly, in the composition for forming a protective film, the ratio of the total content of one or more components contained in the composition for forming a protective film, which will be described later, to the total mass of the composition for forming a protective film is 100 mass % or less.

[0051] The protective film-forming composition may be applied by a known method, such as a method using various coaters such as an air knife coater, blade coater, bar coater, gravure coater, roll coater, roll knife coater, curtain coater, die coater, knife coater, screen coater, Mayer bar coater, or kiss coater.

[0052] The drying conditions for the protective film-forming composition are not particularly limited. However, when the protective film-forming composition contains a solvent, which will be described later, it is preferable to heat-dry it. The protective film-forming composition containing the solvent is preferably heat-dried, for example, at 70 to 130°C for 10 seconds to 5 minutes. However, it is preferable to heat-dry the thermosetting protective film-forming composition so as not to thermally cure the composition itself or the thermosetting protective film-forming film formed from this composition.

[0053] The thermosetting protective film-forming film, the energy ray-curable protective film-forming film, and the non-curable protective film-forming film will be described below in this order.

[0054] <Thermosetting protective film-forming film, thermosetting protective film-forming composition (III)> The curing conditions when the thermosetting protective film-forming film is thermally cured to form a protective film are not particularly limited, as long as the degree of curing is such that the protective film can fully exhibit its functions. For example, the heating temperature during thermal curing of the thermosetting protective film-forming film is preferably 100 to 200° C., and may be, for example, any one of 110 to 170° C. and 120 to 150° C. The heating time during thermal curing is preferably 0.5 to 5 hours, and may be, for example, any one of 0.5 to 4 hours and 1 to 3 hours.

[0055] A preferred example of a thermosetting protective film-forming film is one containing a polymer component (A), a thermosetting component (B), a thermosetting agent (C), a filler (E), and a colorant (J). Such a thermosetting protective film-forming film can be formed using a thermosetting protective film-forming composition (III) (sometimes abbreviated herein simply as "composition (III)") containing the polymer component (A), the thermosetting component (B), the thermosetting agent (C), the filler (E), and the colorant (J).

[0056] The polymer component (A), thermosetting component (B), thermosetting agent (C), filler (E) and colorant (J) contained in the composition (III) and the thermosetting protective film-forming film may each be one type only or two or more types, and if there are two or more types, their combination and ratio can be selected arbitrarily.

[0057] [Polymer component (A)] The polymer component (A) is a component that can be considered to be formed by the polymerization reaction of a polymerizable compound, and is a component that imparts film-forming properties, flexibility, toughness, ductility, etc. to the thermosetting protective film-forming film, and that imparts flexibility, toughness, ductility, etc. to the protective film. In this specification, the polymerization reaction also includes a polycondensation reaction.

[0058] Examples of the polymer component (A) include acrylic resins, urethane resins, phenoxy resins, silicone resins, saturated polyester resins, etc., with acrylic resins being preferred.

[0059] The acrylic resin in the polymer component (A) may be any known acrylic polymer. The weight-average molecular weight (Mw) of the acrylic resin is preferably 10,000 to 2,000,000, and may be, for example, any one of 100,000 to 1,500,000, 150,000 to 1,200,000, and 200,000 to 1,000,000. When the weight-average molecular weight of the acrylic resin is equal to or greater than the lower limit, the shape stability (stability over time during storage) of the protective film-forming film is improved. When the weight-average molecular weight of the acrylic resin is equal to or less than the upper limit, the protective film-forming film can more easily conform to the uneven surface of the adherend.

[0060] In this specification, unless otherwise specified, the "weight average molecular weight" is a polystyrene equivalent value measured by gel permeation chromatography (GPC).

[0061] The glass transition temperature (Tg) of the acrylic resin is preferably 0 to 70°C, and may be, for example, any of 0 to 50°C, 0 to 30°C, and 0 to 10°C. When the Tg of the acrylic resin is equal to or greater than the lower limit, adhesion between the protective film and the support sheet described below is suppressed, and the releasability of the support sheet is appropriately improved. When the Tg of the acrylic resin is equal to or less than the upper limit, the protective film-forming film can easily conform to the uneven surface of the adherend.

[0062] When an acrylic resin has two or more structural units, the glass transition temperature (Tg) of the acrylic resin can be calculated using the Fox equation. The Tg of the homopolymer of the monomer from which the structural units are derived can be calculated using values ​​listed in the Polymer Data Handbook, Adhesive Handbook, or Polymer Handbook.

[0063] Examples of acrylic resins include polymers of one or more (meth)acrylic acid esters; copolymers of two or more monomers selected from the above-mentioned (meth)acrylic acid esters, (meth)acrylic acid, itaconic acid, vinyl acetate, acrylonitrile, styrene, and N-methylolacrylamide.

[0064] Examples of the (meth)acrylic acid ester constituting the acrylic resin include (meth)acrylic acid alkyl esters in which the alkyl group constituting the alkyl ester has a chain structure and has 1 to 18 carbon atoms, such as methyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, sec-butyl (meth)acrylate, tert-butyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate; (Meth)acrylic acid cycloalkyl esters such as dicyclopentanyl (meth)acrylate; glycidyl group-containing (meth)acrylic acid esters such as glycidyl (meth)acrylate; Examples include hydroxyl group-containing (meth)acrylic acid esters such as 2-hydroxyethyl (meth)acrylate.

[0065] In this specification, the term "(meth)acrylic acid" is a concept that encompasses both "acrylic acid" and "methacrylic acid." The same applies to terms similar to (meth)acrylic acid.

[0066] The acrylic resin may be made up of one type of monomer or two or more types of monomers, and when two or more types of monomers are used, the combination and ratio thereof can be selected arbitrarily.

[0067] The acrylic resin may or may not have a functional group capable of bonding to other compounds, such as a vinyl group, a (meth)acryloyl group, an amino group, a hydroxyl group, a carboxy group, an isocyanate group, etc. The functional group of the acrylic resin may bond to other compounds via a crosslinking agent (G) described below, or may bond directly to other compounds without the crosslinking agent (G).

[0068] As the polymer component (A), thermoplastic resins other than acrylic resins, such as polyester, polyurethane, phenoxy resin, polybutene, polybutadiene, and polystyrene, may also be used.

[0069] In composition (III), the proportion of the content of polymer component (A) relative to the total content of all components other than the solvent is preferably 10 to 85 mass %, regardless of the type of polymer component (A), and may be, for example, either 10 to 55 mass % or 10 to 25 mass %. This is equivalent to saying that in the thermosetting protective film-forming film, the content ratio of the polymer component (A) relative to the total mass of the thermosetting protective film-forming film is preferably 10 to 85 mass% regardless of the type of polymer component (A), and may be, for example, either 10 to 55 mass% or 10 to 25 mass%. This is based on the fact that in the process of removing the solvent from a solvent-containing resin composition to form a resin film, the amount of components other than the solvent usually does not change, and the content ratio of the components other than the solvent is the same between the resin composition and the resin film. Therefore, in this specification, not only in the case of the protective film-forming film, but also with respect to the content of the components other than the solvent, only the content in the resin film obtained by removing the solvent from the resin composition will be described.

[0070] The polymer component (A) may also correspond to the thermosetting component (B). In the present invention, when the composition (III) contains components that correspond to both the polymer component (A) and the thermosetting component (B), the composition (III) is considered to contain the polymer component (A) and the thermosetting component (B).

[0071] [Thermosetting component (B)] The thermosetting component (B) has thermosetting properties and is a component for curing the thermosetting protective film-forming film. Examples of the thermosetting component (B) include epoxy-based thermosetting resins, thermosetting polyimide resins, and unsaturated polyester resins, with epoxy-based thermosetting resins being preferred. In this specification, the term "thermosetting polyimide resin" is a general term for a polyimide precursor that forms a polyimide resin by thermal curing, and a thermosetting polyimide.

[0072] Examples of the epoxy resin include known epoxy resins, such as bifunctional or higher functional epoxy compounds, including polyfunctional epoxy resins, biphenyl compounds, bisphenol A diglycidyl ether and its hydrogenated products, orthocresol novolac epoxy resins, dicyclopentadiene-type epoxy resins, biphenyl-type epoxy resins, bisphenol A-type epoxy resins, bisphenol F-type epoxy resins, and phenylene skeleton-type epoxy resins. The epoxy resin may have an unsaturated hydrocarbon group.

[0073] The number average molecular weight of the epoxy resin is not particularly limited, but is preferably 300 to 30,000 in terms of the curability of the thermosetting protective film-forming film and the strength and heat resistance of the protective film that is the cured product thereof. The epoxy equivalent of the epoxy resin is preferably 100 to 1000 g / eq, and may be, for example, either 150 to 600 g / eq or 150 to 400 g / eq.

[0074] [Thermal hardener (C)] When the thermosetting component (B) is an epoxy resin, the composition (III) and the thermosetting protective film-forming film preferably contain a thermosetting agent (C). The thermosetting agent (C) may be, for example, a compound having two or more functional groups per molecule that can react with an epoxy group. Examples of the functional group include a phenolic hydroxyl group, an alcoholic hydroxyl group, an amino group, a carboxyl group, and an anhydride group of an acid group. A phenolic hydroxyl group, an amino group, or an anhydride group of an acid group is preferred, and a phenolic hydroxyl group or an amino group is more preferred.

[0075] Among the heat curing agents (C), examples of phenolic curing agents having a phenolic hydroxyl group include polyfunctional phenolic resins, biphenols, novolac-type phenolic resins, dicyclopentadiene-type phenolic resins, and aralkyl-type phenolic resins. Among the heat curing agents (C), examples of amine-based curing agents having an amino group include dicyandiamide. The heat curing agent (C) may have an unsaturated hydrocarbon group.

[0076] Of the thermosetting agents (C), the number average molecular weight of resin components such as polyfunctional phenolic resins, novolac-type phenolic resins, dicyclopentadiene-type phenolic resins, and aralkyl-type phenolic resins is preferably 300 to 30,000, and may be, for example, any of 400 to 10,000 and 500 to 3,000. Of the thermosetting agent (C), the molecular weight of the non-resin components such as biphenol and dicyandiamide is not particularly limited, but is preferably 60 to 500, for example.

[0077] In the composition (III) and the thermosetting protective film-forming film, the content of the thermosetting agent (C) is preferably 0.1 to 100 parts by mass relative to 100 parts by mass of the content of the thermosetting component (B), and may be, for example, any of 0.5 to 50 parts by mass, 0.5 to 25 parts by mass, 0.5 to 12 parts by mass, and 0.5 to 5 parts by mass. When the content of the thermosetting agent (C) is equal to or greater than the lower limit, curing of the thermosetting protective film-forming film proceeds more easily. When the content of the thermosetting agent (C) is equal to or less than the upper limit, the moisture absorption rate of the thermosetting protective film-forming film is reduced, and the adhesive reliability of the protective film to the adherend is further improved.

[0078] In the thermosetting protective film-forming film, the ratio of the total content of the thermosetting component (B) and the thermosetting agent (C) to the total mass of the thermosetting protective film-forming film is preferably 5 to 40 mass%, and may be, for example, any of 5 to 30 mass%, 5 to 20 mass%, 10 to 40 mass%, 13 to 40 mass%, or 10 to 30 mass%. When the ratio is within this range, the protective effect of the protective film and the adhesive reliability of the protective film to the adherend are further improved. Furthermore, the adhesion between the protective film and the support sheet described below is appropriately suppressed, improving the releasability of the support sheet.

[0079] [Filler (E)] By including the filler (E) in the thermosetting protective film-forming film, the thermal expansion coefficient of the thermosetting protective film-forming film and its cured product (protective film) can be easily adjusted, and by optimizing this thermal expansion coefficient for the object on which the protective film is formed, the adhesive reliability of the protective film to the adherend can be further improved. Furthermore, by including the filler (E) in the thermosetting protective film-forming film, it is possible to reduce the moisture absorption rate of the protective film and improve its heat dissipation properties. Meanwhile, by adjusting the type and content of the filler (E) contained in the protective film-forming film, it is possible to adjust the peel strength of the above-mentioned protective film-forming film and its cured product.

[0080] The filler (E) may be either an organic filler or an inorganic filler, but is preferably an inorganic filler. Preferred inorganic fillers include, for example, powders of silica, alumina, talc, red iron oxide, silicon carbide, boron nitride, etc.; beads obtained by spheronizing these inorganic fillers; surface-modified products of these inorganic fillers; single-crystal fibers of these inorganic fillers; glass fibers, etc. Among these, the inorganic filler is preferably silica or alumina, and more preferably silica.

[0081] In the composition (III), in terms of improving the dispersibility of the filler (E) in other components, the silica is preferably silica surface-modified with an organic group (organic compound), more preferably silica surface-modified with a vinyl group, an epoxy group, a phenyl group or a methacryl group, and particularly preferably silica surface-modified with a vinyl group or an epoxy group.

[0082] In the composition (III), the average particle size of the filler (E) is preferably 0.02 to 2 μm, more preferably 0.05 to 1 μm, and particularly preferably 0.07 to 0.7 μm, in order to improve the dispersibility of the filler (E) in the other components. In this specification, unless otherwise specified, the term "average particle size" refers to the particle size at 50% of the integrated value in the particle size distribution curve obtained by the laser diffraction scattering method (D 50) value.

[0083] In the thermosetting protective film-forming film, the content ratio of the filler (E) relative to the total mass of the thermosetting protective film-forming film is preferably 60 mass% or less, and may be, for example, any one of 50 mass% or less, 40 mass% or less, 30 mass% or less, and 20 mass% or less. When the ratio is equal to or less than the upper limit, the thermal expansion coefficient, moisture absorption rate, heat dissipation property, etc. of the protective film can be adjusted, and the peel strength of the protective film-forming film and its cured product can be increased. On the other hand, there is no particular limitation on the lower limit of the proportion. For example, when the proportion is 5% by mass or more, the effect obtained by using the filler (E) becomes greater.

[0084] Colorant (J) The colorant (J) is a component for adjusting the light reflectance of the thermosetting protective film-forming film and the protective film. Examples of the colorant (J) include known ones such as inorganic pigments, organic pigments, and organic dyes.

[0085] It is preferable that the colorant (J) is a white pigment, that is, that the thermosetting protective film-forming film contains a white pigment. As explained above, when the thermosetting protective film-forming film contains a white pigment, the reflectance of the thermosetting protective film-forming film and its thermoset product to light (420 to 700 nm) can be further increased. This also improves the visibility of light-colored printing on the protective film.

[0086] Examples of the white pigment include titanium oxide (more specifically, titanium dioxide such as rutile titanium dioxide and anatase titanium dioxide), zinc oxide, zirconium oxide, magnesium oxide, calcium oxide, tin oxide, barium oxide, cesium oxide, yttrium oxide, magnesium carbonate, calcium carbonate (more specifically, light calcium carbonate, heavy calcium carbonate, etc.), barium carbonate, zinc carbonate, aluminum hydroxide, calcium hydroxide, magnesium hydroxide, zinc hydroxide, aluminum silicate, magnesium silicate, calcium silicate, barium sulfate, calcium sulfate, barium stearate, zinc white, zinc sulfide, talc, clay, kaolin, titanium phosphate, mica, gypsum, white carbon, diatomaceous earth, bentonite, lithopone, zeolite, sericite, and hydrated halloysite. Among these, the white pigment is preferably titanium oxide.

[0087] When the colorant (J) is a white pigment, the average particle size of the white pigment is preferably 0.05 to 2 μm, more preferably 0.1 to 1 μm, and even more preferably 0.2 to 0.7 μm, from the viewpoints of improving the dispersibility of the colorant (J) in the other components in the composition (III) and efficiently increasing the reflectance of light (420 to 700 nm). In order to improve the dispersibility of colorant (J) in other components, the surface of colorant (J) may be surface-treated with a surface treatment agent such as an inorganic compound having a hydroxyl group or an organic compound having a hydroxyl group or a carboxyl group. In such a surface-treated colorant (J), the portion derived from the surface treatment agent is also considered to be part of the particle, and the particle size of colorant (J) including the portion derived from the surface treatment agent is specified, and the average particle size of colorant (J) is calculated based on the particle size.

[0088] When the thermosetting protective film-forming film contains a white pigment as the colorant (J), the ratio of the content of the white pigment in the thermosetting protective film-forming film to the total mass of the thermosetting protective film-forming film is the same as the ratio of the content of the white pigment in the protective film-forming film to the total mass of the protective film-forming film described above. The effects in this case are also as described above.

[0089] When the composition (III) and the protective film-forming film contain at least a white pigment as the colorant (J), the ratio of the content of the white pigment to the total content of the colorant (J) (the total content of the white pigment and colorants other than the white pigment) in the composition (III) and the protective film-forming film is preferably 90 to 100 mass%, more preferably 95 to 100 mass%, and may be, for example, either 97 to 100 mass% or 99 to 100 mass%. When the ratio is equal to or greater than the lower limit, the effect of using the white pigment is further enhanced.

[0090] The composition (III) and the thermosetting protective film-forming film may or may not contain other components other than the polymer component (A), the thermosetting component (B), the thermosetting agent (C), the filler (E) and the colorant (J). Examples of the other components include a curing accelerator (D), a coupling agent (F), a crosslinking agent (G), an energy ray-curable component (H), a photopolymerization initiator (I), and a general-purpose additive (K).

[0091] The curing accelerator (D), coupling agent (F), crosslinking agent (G), energy ray curable component (H), photopolymerization initiator (I) and general-purpose additive (K) contained in the composition (III) and the thermosetting protective film-forming film may each be one type only or two or more types, and when there are two or more types, the combination and ratio thereof can be selected arbitrarily.

[0092] [Curing accelerator (D)] The curing accelerator (D) is a component for adjusting the curing rate of the thermosetting protective film-forming film. Preferred examples of the curing accelerator (D) include imidazoles (imidazoles in which one or more hydrogen atoms are substituted with 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; tertiary amines; organic phosphines (phosphines in which one or more hydrogen atoms are substituted with organic groups); and tetraphenylboron salts.

[0093] When the curing accelerator (D) is used, the content of the curing accelerator (D) in the thermosetting protective film-forming film is preferably 0.01 to 10 parts by mass, and may be, for example, 0.1 to 7 parts by mass or 0.5 to 5 parts by mass, relative to 100 parts by mass of the total content of the thermosetting component (B) and the thermosetting agent (C). When the content of the curing accelerator (D) is equal to or greater than the lower limit, the effect of using the curing accelerator (D) is more pronounced. When the content of the curing accelerator (D) is equal to or less than the upper limit, for example, the effect of suppressing the highly polar curing accelerator (D) from migrating to the adhesive interface with the adherend and segregating in the thermosetting protective film-forming film under high temperature and high humidity conditions is enhanced. As a result, the adhesive reliability of the protective film to the adherend is further improved.

[0094] [Coupling agent (F)] By using a coupling agent (F) having a functional group capable of reacting with an inorganic compound or an organic compound, the adhesive reliability of the protective film to the adherend can be improved.

[0095] The coupling agent (F) is preferably a compound having a functional group capable of reacting with the functional group of the polymer component (A), the thermosetting component (B), etc., and is more preferably a silane coupling agent.

[0096] Preferred examples of the silane coupling agent include 3-glycidyloxypropyltrimethoxysilane, 3-glycidyloxypropylmethyldiethoxysilane, 3-glycidyloxypropyltriethoxysilane, and 3-glycidyloxymethyldiethoxysilane.

[0097] Preferred examples of the silane coupling agent include oligomeric silane coupling agents having multiple alkoxysilyl groups in one molecule. The oligomeric silane coupling agent is preferred in that it is less likely to volatilize and has multiple alkoxysilyl groups in one molecule, making it effective in improving the durability of the protective film. Examples of the oligomeric silane coupling agents include epoxy group-containing oligomeric silane coupling agents "X-41-1053," "X-41-1059A," "X-41-1056," and "X-40-2651" (all manufactured by Shin-Etsu Chemical Co., Ltd.); and mercapto group-containing oligomeric silane coupling agents "X-41-1818," "X-41-1810," and "X-41-1805" (all manufactured by Shin-Etsu Chemical Co., Ltd.).

[0098] When a coupling agent (F) is used, the content of the coupling agent (F) in the composition (III) and the thermosetting protective film-forming film is preferably 0.03 to 5 parts by mass, and may be, for example, 0.03 to 3 parts by mass or 0.03 to 1 part by mass, relative to 100 parts by mass of the total content of the polymer component (A), the thermosetting component (B), and the thermosetting agent (C). When the content of the coupling agent (F) is equal to or greater than the lower limit, the effects of using the coupling agent (F), such as improved dispersibility of the filler (E) in the resin and improved adhesion reliability of the protective film to the adherend, are more significantly obtained. When the content of the coupling agent (F) is equal to or less than the upper limit, outgassing is further suppressed.

[0099] [Crosslinker (G)] When the polymer component (A) is the above-mentioned acrylic resin or the like and has a functional group capable of bonding with other compounds, such as a vinyl group, a (meth)acryloyl group, an amino group, a hydroxyl group, a carboxyl group, or an isocyanate group, the crosslinking agent (G) bonds the functional group in the polymer component (A) with other compounds to crosslink them. In this case, the adhesive strength and cohesive strength of the protective film-forming film can be adjusted.

[0100] Examples of the crosslinking agent (G) include organic polyvalent isocyanate compounds, organic polyvalent imine compounds, metal chelate crosslinking agents (crosslinking agents having a metal chelate structure), and aziridine crosslinking agents (crosslinking agents having an aziridinyl group).

[0101] When a crosslinking agent (G) is used, the content of the crosslinking agent (G) in the composition (III) is preferably 0.01 to 20 parts by mass, more preferably 0.1 to 10 parts by mass, and even more preferably 0.5 to 5 parts by mass, per 100 parts by mass of the polymer component (A). When the content of the crosslinking agent (G) is equal to or greater than the lower limit, the effect of using the crosslinking agent (G) is more pronounced. When the content of the crosslinking agent (G) is equal to or less than the upper limit, excessive use of the crosslinking agent (G) is suppressed.

[0102] [Energy ray curable component (H)] The thermosetting protective film-forming film contains the energy ray-curable component (H), and thus its properties can be changed by irradiation with energy rays.

[0103] The energy ray-curable component (H) is an energy ray-curable compound, or an energy ray-curable oligomer or polymer (polymer) that can be considered to have been synthesized from an energy ray-curable compound. Examples of the energy ray-curable compound include compounds having at least one polymerizable double bond in the molecule, and acrylate compounds having a (meth)acryloyl group are preferred.

[0104] When the energy ray-curable component (H) is used, the content of the energy ray-curable component (H) in the thermosetting protective film-forming film is preferably 1 to 20 mass% relative to the total mass of the thermosetting protective film-forming film. When the content is within this range, the effects of using the energy ray-curable component (H) can be satisfactorily obtained without impairing other properties of the thermosetting protective film-forming film.

[0105] It is preferable that the thermosetting protective film-forming film does not substantially contain an energy ray (e.g., ultraviolet ray) curable component. Even if such a thermosetting protective film-forming film has the property of reflecting energy rays, it can form a cured product having a sufficient degree of curing by thermal curing without requiring irradiation with energy rays. In this specification, "the protective film-forming film does not substantially contain an energy ray-curable component" means that the content of the energy ray-curable component in the protective film-forming film is 0 to 0.3 mass% relative to the total mass of the protective film-forming film.

[0106] [Photopolymerization initiator (I)] The photopolymerization initiator (I) is a component for efficiently promoting the polymerization reaction of the energy ray-curable component (H). The photopolymerization initiator (I) may be a known one.

[0107] When the photopolymerization initiator (I) is used, the content of the photopolymerization initiator (I) in the composition (III) and the thermosetting protective film-forming film is preferably 0.1 to 20 parts by mass per 100 parts by mass of the content of the energy ray-curable component (H).

[0108] [General Purpose Additives (K)] The general-purpose additive (K) may be a known one and can be selected arbitrarily depending on the purpose, without any particular limitation. Preferable general-purpose additives (K) include, for example, plasticizers, antistatic agents, antioxidants, gettering agents, ultraviolet absorbers, and tackifiers. The content of the general-purpose additive (K) in the composition (III) and the thermosetting protective film-forming film is not particularly limited and may be appropriately selected depending on the purpose.

[0109] [solvent] Composition (III) preferably further contains a solvent, which improves the handleability of composition (III). In this specification, unless otherwise specified, the term "solvent" is used to refer to a concept that includes not only a substance that dissolves a target component, but also a dispersion medium that disperses the target component.

[0110] The solvent is not particularly limited, but preferred examples include hydrocarbons such as toluene; alcohols such as methanol; esters such as ethyl acetate; ketones such as acetone and methyl ethyl ketone; ethers such as tetrahydrofuran; and amides (compounds having an amide bond) such as dimethylformamide and N-methylpyrrolidone. The composition (III) may contain only one type of solvent, or two or more types of solvents. When two or more types of solvents are contained, the combination and ratio thereof can be selected arbitrarily.

[0111] The content of the solvent in the composition (III) is not particularly limited, and may be appropriately selected depending on, for example, the types of components other than the solvent.

[0112] <Method for producing a thermosetting protective film-forming composition> A thermosetting composition for forming a protective film such as composition (III) can be obtained by blending the components that constitute the composition. The temperature and time for adding and mixing each component are not particularly limited as long as the components do not deteriorate, and may be adjusted appropriately. A temperature of 15 to 30°C is preferred.

[0113] <Energy ray-curable protective film-forming film, energy ray-curable protective film-forming composition (IV)> The curing conditions when the energy ray-curable protective film-forming film is cured with energy rays to form a protective film are not particularly limited as long as the degree of curing is such that the protective film can fully exhibit its functions. For example, the irradiance of the energy ray during energy ray curing of the energy ray curable protective film-forming film is 60 to 320 mW / cm 2 The amount of energy rays during the curing is preferably 100 to 1000 mJ / cm. 2 It is preferable that:

[0114] A preferred example of the energy ray-curable protective film-forming film is one containing an energy ray-curable component (a), a filler, and a colorant. Such an energy ray-curable protective film-forming film can be formed using an energy ray-curable protective film-forming composition (IV) (sometimes abbreviated herein simply as "composition (IV)") containing the energy ray-curable component (a), a filler, and a colorant.

[0115] The composition (IV) and the energy ray-curable protective film-forming film may or may not contain other components other than the energy ray-curable component (a), the filler, and the colorant. Examples of the other components include a polymer (b) having no energy ray-curable group, a coupling agent, a crosslinking agent, a photopolymerization initiator, and general-purpose additives.

[0116] Examples of the energy ray-curable component (a), the polymer (b) not having an energy ray-curable group, the filler, the colorant, the coupling agent, the crosslinking agent, the photopolymerization initiator and the general-purpose additives include the same as those contained in the composition (III) and the thermosetting protective film-forming film, namely, the energy ray-curable component (H), the polymer component (A) not having an energy ray-curable group, the filler (E), the colorant (J), the coupling agent (F), the crosslinking agent (G), the photopolymerization initiator (I) and the general-purpose additive (K).

[0117] The content of each of the above-mentioned components in the composition (IV) and the energy ray-curable protective film-forming film may be adjusted appropriately depending on the purpose. For example, when the energy ray-curable protective film-forming film contains a white pigment as a colorant, the ratio of the content of the white pigment in the energy ray-curable protective film-forming film to the total mass of the energy ray-curable protective film-forming film is the same as the ratio of the content of the white pigment in the protective film-forming film to the total mass of the protective film-forming film described above.The effects in this case are also as described above.

[0118] Composition (IV) preferably further contains a solvent similar to that used in composition (III), since dilution improves its handling properties.

[0119] The energy ray-curable protective film-forming composition such as composition (IV) can be obtained by blending the components that constitute it. The energy ray-curable composition for forming a protective film can be produced in the same manner as the heat-curable composition for forming a protective film described above, except that the types of ingredients used are different.

[0120] <Non-curable protective film-forming film, non-curable protective film-forming composition (V)> A preferred non-curable protective film-forming film includes, for example, one containing a polymer component, a filler, and a colorant. Such a non-curable protective film-forming film can be formed using a non-curable protective film-forming composition (V) (sometimes abbreviated herein simply as "composition (V)") containing the polymer component, a filler, and a colorant.

[0121] The composition (V) and the non-curable protective film-forming film may or may not contain other components other than the polymer component, filler, and colorant. Examples of the other components include coupling agents, crosslinking agents, and general-purpose additives.

[0122] The polymer component, filler, colorant, coupling agent, crosslinking agent and general-purpose additive may be the same as the polymer component (A), filler (E), colorant (J), coupling agent (F), crosslinking agent (G) and general-purpose additive (K) contained in the composition (III) and the thermosetting protective film-forming film, respectively.

[0123] The content of each of the above-mentioned components in the composition (V) and the non-curable protective film-forming film may be adjusted appropriately depending on the purpose. For example, when the non-curable protective film-forming film contains a white pigment as a colorant, the ratio of the content of the white pigment in the non-curable protective film-forming film to the total mass of the non-curable protective film-forming film is the same as the ratio of the content of the white pigment in the protective film-forming film to the total mass of the protective film-forming film described above. The effects in this case are also as described above.

[0124] Composition (V) preferably further contains a solvent similar to that used in composition (III), since dilution improves its handling properties.

[0125] A non-curable protective film-forming composition such as composition (V) can be obtained by blending the components that constitute it. The non-curable protective film-forming composition can be produced in the same manner as the thermosetting protective film-forming composition described above, except that the types of ingredients used are different.

[0126] ◎Examples of protective film forming films A preferred example of the protective film-forming film is a protective film-forming film for forming a protective film on any part of a workpiece obtained by processing a workpiece, the protective film-forming film is a thermosetting protective film-forming film containing a polymer component (A), a thermosetting component (B), a thermosetting agent (C), a filler (E), and a colorant (J), The protective film-forming film may have a reflectance of more than 55% for light in the entire wavelength range of 420 to 700 nm when it is thermally cured. Such a protective film-forming film contains a white pigment as the colorant (J), and in the protective film-forming film, the content ratio of the white pigment to the total mass of the protective film-forming film is more than 7 mass%, In the protective film-forming film, it is preferable that the content ratio of the filler (E) to the total mass of the protective film-forming film is 60 mass% or less (however, in the protective film-forming film, the total content ratio of the polymer component (A), thermosetting component (B), thermosetting agent (C), filler (E) and colorant (J) to the total mass of the protective film-forming film does not exceed 100 mass%). Furthermore, in such a protective film-forming film, it is preferable that the content ratio of the polymer component (A) relative to the total mass of the protective film-forming film is 10 to 85 mass%, the total content ratio of the thermosetting component (B) and the thermosetting agent (C) is 5 to 40 mass%, and the content of the thermosetting agent (C) is 0.1 to 100 mass parts per 100 mass parts of the thermosetting component (B) (however, in the protective film-forming film, the total content ratio of the polymer component (A), the thermosetting component (B), the thermosetting agent (C), the filler (E) and the colorant (J) relative to the total mass of the protective film-forming film does not exceed 100 mass%).

[0127] 1 is a cross-sectional view schematically illustrating an example of a protective film-forming film according to one embodiment of the present invention. In addition, in the drawings used in the following description, for the sake of convenience, in order to make the features of the present invention easier to understand, the main parts may be shown enlarged, and the dimensional ratios of each component may not necessarily be the same as in reality.

[0128] The protective film-forming film 13 shown here has a first release film 151 on one surface (sometimes referred to herein as the "first surface") 13a thereof, and a second release film 152 on the other surface (sometimes referred to herein as the "second surface") 13b opposite the first surface 13a. By providing the protective film-forming film 13 with the first release film 151 and the second release film 152, adhesion of foreign matter to the first surface 13a and the second surface 13b of the protective film-forming film 13 is suppressed. However, the release film has an optional configuration, and the protective film-forming film 13 does not necessarily have to have either the first release film 151 or the second release film 152. Such a protective film-forming film 13 is suitable for storage in a roll form, for example.

[0129] When the protective film-forming film 13 is curable, the reflectance of the cured product of the protective film-forming film 13 for light in the entire wavelength range of 420 to 700 nm is greater than 55%, and when the protective film-forming film 13 is non-curable, the reflectance of the protective film-forming film 13 for light in the entire wavelength range of 420 to 700 nm is greater than 55%.

[0130] The first release film 151 and the second release film 152 may both be known films. The first release film 151 and the second release film 152 may be the same as each other, or may be different from each other, for example, by requiring different peeling forces when peeling them from the protective film-forming film 13. Both the first release film 151 and the second release film 152 are preferably release films formed by forming a silicone-based release agent layer on one side of a polyethylene terephthalate film (by silicone treatment).

[0131] Either the first surface 13a or the second surface 13b of the protective film-forming film 13 becomes the surface to be attached to any location on the workpiece, and the other becomes the surface to be attached to the support sheet or processing sheet described below.

[0132] The protective film-forming film of this embodiment can be attached to any location on the workpiece without using a support sheet (described later), and on the other hand, by using it in combination with a support sheet (described later), a composite sheet for forming a protective film can be configured for performing both protective film formation and dicing. Such a composite sheet for forming a protective film will be described below.

[0133] ◇Composite sheet for forming protective film The composite sheet for forming a protective film comprises a support sheet and a protective film-forming film provided on one side of the support sheet, and the protective film-forming film is the protective film-forming film according to one embodiment of the present invention described above. The composite sheet for forming a protective film may be the same as a conventional composite sheet for forming a protective film, except that it includes the protective film-forming film of this embodiment.

[0134] In this specification, as long as the laminated structure of the support sheet and the cured product of the protective film-forming film is maintained even after the protective film-forming film has hardened, this laminated structure is referred to as a "composite sheet for forming a protective film."

[0135] ◎Support sheet Examples of the support sheet include known ones such as one comprising a substrate and a pressure-sensitive adhesive layer provided on one side of the substrate, one consisting of only a substrate, etc. When the support sheet comprises a pressure-sensitive adhesive layer, the pressure-sensitive adhesive layer is disposed between the substrate and the protective film-forming film in the composite sheet for forming a protective film.

[0136] The substrate and the adhesive layer may each consist of one layer (single layer) or two or more layers. When consisting of multiple layers, these multiple layers may be the same or different from each other, and the combination of these multiple layers is not particularly limited.

[0137] ◎Example of a composite sheet for forming a protective film FIG. 2 is a cross-sectional view schematically showing an example of a composite sheet for forming a protective film provided with a protective film-forming film according to one embodiment of the present invention. In FIG. 2 and subsequent figures, the same components as those shown in the figures already described are given the same reference numerals as in the figures already described, and detailed description thereof will be omitted.

[0138] The composite sheet 101 for forming a protective film shown here is composed of a support sheet 10 and a protective film forming film 13 provided on one side 10a of the support sheet 10 (sometimes referred to as the "first side" in this specification). The support sheet 10 is configured to include a base material 11 and an adhesive layer 12 provided on one surface (first surface) 11a of the base material 11. In the composite sheet 101 for forming a protective film, the adhesive layer 12 is disposed between the base material 11 and the protective film-forming film 13. The first surface 10a of the support sheet 10 is the same as the surface 12a of the pressure-sensitive adhesive layer 12 opposite to the substrate 11 side (sometimes referred to as the "first surface" in this specification).

[0139] The composite sheet 101 for forming a protective film further includes a jig adhesive layer 16 and a release film 15 on the protective film-forming film 13. The jig adhesive layer 16 is laminated in an area near the peripheral edge of the first surface 13a of the protective film-forming film 13. The jig adhesive layer 16 is a layer for fixing the composite sheet for forming a protective film 101 to a jig such as a ring frame, and may be a known layer. The release film 15 is of any configuration.

[0140] The composite sheet 101 for forming a protective film is used by removing the release film 15, attaching any part of the work (for example, the back surface of a semiconductor wafer) to the first surface 13a of the protective film-forming film 13, and further attaching the surface 16a of the jig adhesive layer 16 opposite to the side of the protective film-forming film 13 to a jig such as a ring frame.

[0141] The composite sheet for forming a protective film of this embodiment is not limited to that shown in Figure 2, and may be one in which some of the configuration shown in Figure 2 has been changed or deleted, or one in which other configurations have been added to those described above, within the scope that does not impair the effects of the present invention. For example, the size of the protective film-forming film is smaller than the size of the support sheet, and in this case, the jig adhesive layer may be provided on the support sheet. For example, the composite sheet for forming a protective film of this embodiment does not need to be provided with a jig adhesive layer. For example, in the composite sheet for forming a protective film of this embodiment, the support sheet may consist of only a substrate, and in that case, the substrate may be adhesive at least on the surface facing the protective film-forming film.

[0142] ○Base material The substrate is in the form of a sheet or film, and examples of the constituent materials thereof include various resins. The resin constituting the substrate may be one type only, or two or more types, and when two or more types are used, the combination and ratio thereof can be selected arbitrarily. Examples of the resin include polyolefins such as polyethylene and polypropylene; ethylene-based copolymers (copolymers obtained using ethylene as a monomer) such as ethylene-vinyl acetate copolymer, ethylene-(meth)acrylic acid copolymer, and ethylene-(meth)acrylic acid ester copolymer; polystyrene; polycycloolefins; and polyesters such as polyethylene terephthalate. The resin may be any of a polymer alloy such as a mixture of two or more of the above-mentioned resins, a crosslinked resin in which one or more of the above-mentioned resins are crosslinked, and a modified resin such as an ionomer using one or more of the above-mentioned resins.

[0143] The substrate may contain, in addition to the main constituent materials such as the resin, various known additives such as fillers, colorants, antioxidants, organic lubricants, catalysts, and softeners (plasticizers).

[0144] The thickness of the substrate is preferably 50 to 300 μm, more preferably 50 to 120 μm. When the thickness of the substrate is in this range, the flexibility of the composite sheet for forming a protective film and the suitability for attachment to a workpiece are further improved.

[0145] The substrate can be produced by a known method. For example, a substrate containing a resin can be produced by molding a resin composition containing the resin.

[0146] Adhesive layer The pressure-sensitive adhesive layer is in the form of a sheet or film and contains a pressure-sensitive adhesive resin. Examples of the adhesive resin include acrylic resin, urethane resin, rubber-based resin, silicone resin, epoxy-based resin, polyvinyl ether, polycarbonate, and ester-based resin.

[0147] The thickness of the pressure-sensitive adhesive layer is not particularly limited, but is preferably 1 to 100 μm, and more preferably 3 to 20 μm.

[0148] The pressure-sensitive adhesive layer may be either energy ray curable or non-energy ray curable.

[0149] The pressure-sensitive adhesive layer can be formed using a pressure-sensitive adhesive composition containing a pressure-sensitive adhesive resin. For example, the pressure-sensitive adhesive composition can be applied to a surface on which the pressure-sensitive adhesive layer is to be formed, and then dried as necessary, to form the pressure-sensitive adhesive layer at the desired location. The application and drying of the pressure-sensitive adhesive composition can be carried out, for example, by the same method as in the application and drying of the above-mentioned composition for forming a protective film.

[0150] The pressure-sensitive adhesive composition can be obtained by blending the pressure-sensitive adhesive resin and, if necessary, components other than the pressure-sensitive adhesive resin, and other components for constituting the pressure-sensitive adhesive composition. The pressure-sensitive adhesive composition can be produced by the same method as the above-described composition for forming a protective film, except that the types of ingredients used are different.

[0151] ◇Manufacturing method of composite sheet for forming protective film The composite sheet for forming a protective film can be produced by laminating the above-mentioned layers in a corresponding positional relationship and adjusting the shapes of some or all of the layers as necessary. The method for forming each layer is as described above.

[0152] When producing a support sheet, for example, an adhesive composition is applied to a release film and dried as necessary to form an adhesive layer on the release film, and the exposed surface of this adhesive layer is then attached to one surface of the substrate, thereby laminating the adhesive layer on the substrate. When laminating a protective film-forming film on a substrate, for example, a protective film-forming composition is applied to a release film and dried as necessary to form a protective film-forming film on the release film, and the exposed surface of this protective film-forming film is then bonded to one surface of the substrate. When a protective film-forming film is to be laminated on top of an adhesive layer already laminated on a substrate, for example, a protective film-forming film may be formed in advance on a release film using a protective film-forming composition, and the exposed surface of this formed protective film-forming film may then be bonded to the exposed surface of the adhesive layer.

[0153] ◇Manufacturing method for workpieces with protective film (How to use protective film forming film) A method for manufacturing a workpiece with a protective film according to one embodiment of the present invention is a method for manufacturing a workpiece with a protective film using a protective film-forming film according to one embodiment of the present invention described above, and if the protective film-forming film is curable, the cured product of the protective film-forming film is the protective film.If the protective film-forming film is non-curable, the protective film-forming film after being attached to the workpiece is the protective film.The manufacturing method includes an attachment process for attaching the protective film-forming film to the workpiece, a printing process for printing on the protective film-forming film or protective film after the attachment process, a processing process for processing the workpiece to produce the workpiece, and a cutting process for cutting the protective film-forming film or protective film after the attachment process.If the protective film-forming film is curable, the method further includes a curing process for forming the protective film by curing the protective film-forming film after the attachment process. According to the manufacturing method of this embodiment, by using the protective film-forming film, a workpiece with a protective film can be obtained that is inconspicuous on a white substrate in a light-emitting device. The design of a device including such a workpiece with a protective film is high. Furthermore, because the protective film formed from the protective film-forming film makes the workpiece with a protective film inconspicuous on a white substrate, even if the protective film has a high light reflectance, the visibility of the printing on the protective film is good, even if the color is light.

[0154] In each step after the pasting step, whether to handle the protective film-forming film or the protective film is determined by the timing of forming the protective film. When the protective film-forming film is non-curable, it is the protective film that is handled in each step after the pasting step. When the protective film-forming film is curable, it is the protective film-forming film that is handled before the curing step, and it is the protective film that is handled after the curing step.

[0155] In the attaching step, a protective film-forming film that does not constitute the composite sheet for forming a protective film may be attached to the workpiece, or the protective film-forming film in the composite sheet for forming a protective film may be attached to the workpiece.

[0156] When the workpiece is a semiconductor wafer, the protective film-coated workpiece is a semiconductor chip with a protective film comprising a semiconductor chip and a protective film provided on its back surface, and when the protective film-forming film is non-curable, the protective film-forming film after being attached to the back surface of the semiconductor wafer is the protective film, and in this case, the manufacturing method includes a bonding step of bonding the protective film-forming film to the back surface of the semiconductor wafer, a printing step of printing on the protective film-forming film or the protective film after the bonding step, a processing step of producing the semiconductor chip by dividing the semiconductor wafer after the bonding step, and a cutting step of cutting the protective film-forming film or the protective film after the bonding step, and when the protective film-forming film is curable, the method for manufacturing a semiconductor chip with a protective film further includes a curing step of forming the protective film by curing the protective film-forming film after the bonding step.

[0157] Below, the manufacturing method (sometimes referred to as "manufacturing method (1)" in this specification) will be explained using the example of manufacturing a semiconductor chip with a protective film using a composite sheet for forming a protective film shown in Figure 2, which is provided with a thermosetting protective film-forming film.

[0158] 3(a), in the bonding step of the manufacturing method (1), the protective film-forming film 13 in the protective film-forming composite sheet 101 is bonded to the back surface 9b of the semiconductor wafer 9. In this way, a semiconductor wafer 901 with a protective film-forming composite sheet is produced, which includes the semiconductor wafer 9 and the protective film-forming composite sheet 101 provided on the back surface 9b of the semiconductor wafer 9. The composite sheet 101 for forming a protective film can be attached by a known method. Here, bumps and the like on the circuit surface 9a of the semiconductor wafer 9 are not shown.

[0159] In the curing step of the manufacturing method (1), as shown in Fig. 3(b), the protective film 13' is formed by thermally curing the protective film-forming film 13. The heating temperature and heating time during thermal curing of the protective film-forming film 13 are as described above. The cured product of the protective film-forming film 13 has a reflectance of more than 55% for light in the entire wavelength range of 420 to 700 nm, and the protective film 13' also has a reflectance of more than 55% for light in the entire wavelength range of 420 to 700 nm.

[0160] In the printing step of manufacturing method (1), as shown in FIG. 3(c), printing is performed on the protective film 13'. The printing is formed on the second surface 13b' of the protective film 13'. Here, the case where laser printing is performed by irradiating the protective film 13' with laser light R is shown. The laser light R is irradiated onto the protective film 13' through the support sheet 10. Laser marking can be carried out by a known method. In order to obtain the effects of the present invention more remarkably, it is preferable that the color of the print be light.

[0161] For example, when the print on the protective film formed above is observed using a digital microscope (Keyence Corporation's "VHX-7000") under conditions of white balance R=1.77, G=1.00, B=2.31, ring illumination, brightness 100, and shutter speed 1 / 120 sec, a light-colored print is preferably one in which the R value, G value, and B value in the RGB color system are each within the range of 120 to 190. When neutral colors listed on the MM color chart II (manufactured by Japan Color Design Research Institute) were observed using the above method, the standard sample with a brightness of 6, which appears gray to the naked eye under ordinary fluorescent lighting, had an R value of 118, a G value of 118, and a B value of 118. The standard sample with a brightness of 6.5 had an R value of 128, a G value of 128, and a B value of 128. The standard sample with a brightness of 7 had an R value of 147, a G value of 146, and a B value of 144. The standard sample with a brightness of 7.5 had an R value of 171, a G value of 170, and a B value of 166. The standard sample with a brightness of 8 had an R value of 187, a G value of 184, and a B value of 179. The standard sample with a brightness of 8.5 had an R value of 205, a G value of 200, and a B value of 195. Light-color printing can be performed, for example, under the following conditions: laser light wavelength: 355 nm, laser printing speed: 100 mm / s to 1500 mm / s, laser frequency: 40 kHz to 400 kHz, and laser output: 0.4 to 2 W. By using the protective film-forming film 13, the print on the protective film 13' has good visibility even if its color is light.

[0162] In the processing step of manufacturing method (1), semiconductor chips 90 are produced by dividing the semiconductor wafer 9, and in the cutting step, the protective film 13' is cut to form a cut protective film 130', thereby producing semiconductor chips 91 with a protective film, as shown in Figure 3(d). In this specification, the "cut protective film" may be simply referred to as the "protective film." The division of the semiconductor wafer 9 and the cutting of the protective film 13' can both be performed by known methods, and the order is determined depending on the division method and cutting method, and either can be performed first, or they can be performed simultaneously.

[0163] The fabricated semiconductor chip 91 with a protective film can be picked up by separating it from the support sheet 10 using a known method, as shown in Figure 3(e). Here, an example is shown in which the chip is picked up in the direction of arrow P using a separating means 7 such as a vacuum collet. This allows the desired semiconductor chip 91 with a protective film to be taken out. The semiconductor chip 91 with the protective film will not stand out on the white substrate of the light emitting device to be mounted in the subsequent process, and the design of the light emitting device will be improved.

[0164] Up to this point, we have explained the case where the adhering step, curing step, and printing step are performed in this order, and then the processing step and cutting step are performed in any order, but the order in which each step is performed after the adhering step is not limited to this and can be adjusted as appropriate depending on the purpose or the method for performing each step.

[0165] The manufacturing method (1) may include other steps in addition to the adhering step, curing step, printing step, processing step, and cutting step. Examples of the other steps include, when the back surface of the semiconductor wafer is the grinding surface, a step of removing backgrind tape attached to the circuit surface from the circuit surface at a stage prior to the processing step.

[0166] When the protective film-forming film is energy ray curable, a semiconductor chip with a protective film can be manufactured by the same method as the above manufacturing method (1), except that the curing method is different. When the protective film-forming film is non-curable, a semiconductor chip with a protective film can be manufactured by the same method as the above manufacturing method (1), except that the curing step is not performed.

[0167] Next, the manufacturing method (sometimes referred to as "manufacturing method (2)" in this specification) will be explained using the example of manufacturing a semiconductor chip with a protective film using the thermosetting protective film-forming film shown in Figure 1, which does not constitute a composite sheet for forming a protective film.

[0168] In each step of the manufacturing method (2) after the attachment step, whether the protective film-forming film or the protective film is handled is the same as in the manufacturing method (1). Manufacturing method (2) is the same as manufacturing method (1), except that a protective film-forming film that does not constitute a composite sheet for forming a protective film is used instead of a composite sheet for forming a protective film, and preferably, a processing sheet is attached to the protective film-forming film before the processing step is carried out.

[0169] 4(a), in the bonding step of the manufacturing method (2), the protective film-forming film 13 from which the first release film 151 has been removed is bonded to the back surface 9b of the semiconductor wafer 9. In this way, a semiconductor wafer 902 with a protective film-forming film is produced, which includes the semiconductor wafer 9 and the protective film-forming film 13 provided on the back surface 9b of the semiconductor wafer 9. The protective film-forming film 13 can be attached by a known method.

[0170] In the curing step of the manufacturing method (2), the protective film 13' is formed by thermally curing the protective film-forming film 13 from which the second release film 152 has been removed, as shown in Fig. 4(b). The heating temperature and heating time during thermal curing of the protective film-forming film 13 are as described above. The cured product of the protective film-forming film 13 has a reflectance of more than 55% for light in the entire wavelength range of 420 to 700 nm, and the protective film 13' also has a reflectance of more than 55% for light in the entire wavelength range of 420 to 700 nm.

[0171] In the printing step of manufacturing method (2), as shown in FIG. 4(c), printing is performed on the protective film 13'. The printing is formed on the second surface 13b' of the protective film 13'. Here, laser printing is performed by irradiating the protective film 13' with laser light R. The laser light R is directly irradiated onto the protective film 13'. The laser marking method and conditions were the same as those in the manufacturing method (1). By using the protective film-forming film 13, the print on the protective film 13' has good visibility even if its color is light.

[0172] In the printing step of the production method (2), printing may be performed by other known printing methods such as inkjet printing, instead of irradiation with laser light.

[0173] In manufacturing method (2), it is preferable to attach a dicing sheet 80 to the protective film 13' before the processing step, as shown in Fig. 4(d). The dicing sheet 80 is a type of processing sheet and is configured to include a base material 81 and an adhesive layer 82 provided on one surface of the base material 81, but dicing sheets with other configurations may also be used. Processing sheets such as the dicing sheet 80 may be known.

[0174] In the processing step of manufacturing method (2), the semiconductor wafer 9 is divided to produce semiconductor chips 90, and in the cutting step, the protective film 13' is cut to produce cut protective films 130'. As a result, semiconductor chips 91 with protective films similar to those in manufacturing method (1) are produced, as shown in Figure 4(e). The processing step of the production method (2) can be carried out in the same manner as the processing step of the production method (1), and the cutting step of the production method (2) can be carried out in the same manner as the cutting step of the production method (1).

[0175] The produced semiconductor chip 91 with a protective film can be picked up by being separated from the dicing sheet 80 by a known method, as shown in Figure 4(f), in the same manner as in manufacturing method (1). This allows the desired semiconductor chip 91 with a protective film to be taken out. The semiconductor chip 91 with a protective film obtained by the manufacturing method (2) also does not stand out on the white substrate in the light emitting device to be mounted in the subsequent process, improving the design of the light emitting device.

[0176] In the manufacturing method (2), the order of the steps after the attachment step is not limited to the above, and can be adjusted as appropriate depending on the purpose or the method of performing each step.

[0177] The manufacturing method (2) may also include other steps in addition to the adhering step, curing step, printing step, processing step, and cutting step.

[0178] When the protective film-forming film is energy ray curable, a semiconductor chip with a protective film can be manufactured by the same method as the above manufacturing method (2), except that the curing method is different. When the protective film-forming film is non-curable, a semiconductor chip with a protective film can be manufactured by the same method as the above manufacturing method (2), except that the curing step is not performed. [Example]

[0179] The present invention will be described in more detail below with reference to specific examples, although the present invention is not limited to the examples shown below.

[0180] <Raw materials for producing the protective film-forming composition> The raw materials used in the production of the protective film-forming composition are shown below. [Polymer component (A)] (A)-1: An acrylic resin (weight average molecular weight 450,000, glass transition temperature 6°C) obtained by copolymerizing methyl acrylate (87 parts by mass) and 2-hydroxyethyl acrylate (13 parts by mass). [Thermosetting component (B)] (B)-1: Bisphenol A epoxy resin ("jER828" manufactured by Mitsubishi Chemical Corporation, epoxy equivalent weight 184-194g / eq) (B)-2: Dicyclopentadiene-type epoxy resin (DIC Corporation "Epicron HP-7200", epoxy equivalent 254-264g / eq) [Thermal hardener (C)] (C)-1: Dicyandiamide ("DICY7" manufactured by Mitsubishi Chemical Corporation) [Curing accelerator (D)] (D)-1:2-Phenyl-4,5-dihydroxymethylimidazole ("Curezol 2PHZ" manufactured by Shikoku Chemicals Corporation) [Filler (E)] (E)-1: Silica filler ("SC2050MB" manufactured by Admatechs Co., Ltd., silica filler surface-modified with an epoxy compound, average particle diameter 0.5 μm) [Coupling agent (F)] (F)-1: Oligomeric silane coupling agent having epoxy, methyl, and methoxy groups ("X-41-1056" manufactured by Shin-Etsu Chemical Co., Ltd., epoxy equivalent: 280 g / eq) [Crosslinker (G)] (G)-1: Tolylene diisocyanate trifunctional crosslinking agent (Mitsui Chemicals, Inc. "Takenate D-101E") Colorant (J) (J)-1: White pigment (rutile-type titanium dioxide surface-treated with an inorganic compound having a hydroxyl group, average particle size 0.35 μm) (J)-2: Bright red dye (Rhodamine B, Fujifilm Wako Pure Chemical Industries, Ltd.) (J)-3: Blue pigment (copper phthalocyanine blue pigment, "NX-053 Blue" manufactured by Dainichiseika Color & Chemicals Mfg. Co., Ltd.)

[0181] [Example 1] <<Protective Film Forming Film Manufacturing>> <Production of protective film-forming composition (III)> Each component was dissolved or dispersed in methyl ethyl ketone so that the type and content of the components contained in the protective film-forming film were as shown in Table 1, and the mixture was stirred at 23°C to obtain a thermosetting protective film-forming composition (III) having a total concentration of all components other than the solvent of 57 mass%.

[0182] <Production of protective film-forming film> A release film (second release film, "SP-PET50 2150" manufactured by Lintec Corporation, thickness 50 μm) made of polyethylene terephthalate film, one side of which had been treated for release by silicone treatment, was used, and the protective film-forming composition (III) obtained above was applied to the release-treated surface, followed by drying at 100°C for 2 minutes to produce a thermosetting protective film-forming film with a thickness of 25 μm.

[0183] Furthermore, the release-treated surface of a release film (first release film, "SP-PET38 1130" manufactured by Lintec Corporation, thickness 38 μm) was attached using a laminating roll to the exposed surface of the obtained protective film-forming film that was not provided with the second release film. As a result of the above, a laminated film was obtained comprising a protective film-forming film, a first release film provided on one side of the protective film-forming film, and a second release film provided on the other side of the protective film-forming film.

[0184] <<Evaluation of protective film forming films>> <Measurement of the reflectance of light (420 to 700 nm) of the cured protective film> One side of the silicon wafer was ground with a #2000 wheel to prepare a silicon wafer (thickness 350 μm) having a ground surface. The first release film was removed from the protective film-forming film in the laminated film obtained above, and the exposed surface of the protective film-forming film was attached to the ground surface of the silicon wafer using a roller heated to 70 ° C. at a lamination speed of 0.3 m / min. Next, the second release film was removed from the protective film-forming film after application, and the resulting silicon wafer with the protective film-forming film was heated at 140°C for 2 hours to thermally cure the protective film-forming film into a cured product (forming a protective film), thereby obtaining a silicon wafer with a protective film.

[0185] The resulting silicon wafer with the protective film was allowed to cool to 23°C, and the total reflected light (specularly reflected light and diffusely reflected light) was measured for the exposed surface of the cured product (the surface opposite the silicon wafer) in the wavelength range of 380 to 780 nm at 1 nm intervals using the SCI method. The total reflected light was also measured for a barium sulfate reference plate using the same method. In both cases, the total reflected light was measured using a UV-Vis spectrophotometer (Shimadzu Corporation, UV-VIS-NIR SPECTROPHOTOMETER UV-3600). A Shimadzu Corporation, Large Sample Chamber MPC-3100, was used as the sample holder, and a Shimadzu Corporation, Integrating Sphere Accessory ISR-3100, was used as the integrating sphere, with the incident angle of light on the measurement target set at 8°. Then, the ratio of the measured value of the cured product to the measured value of the reference plate (measured value of the total reflected light amount of the cured product of the protective film-forming film / measured value of the total reflected light amount of the reference plate × 100), i.e., the relative total light reflectance of the cured product of the protective film-forming film, was calculated. Of the obtained relative total light reflectances, the value in the wavelength range of 420 to 700 nm was used as the reflectance of light (420 to 700 nm).

[0186] <Calculation of the difference between the maximum and minimum reflectance values ​​of light (420 to 700 nm) of the cured protective film-forming film> When measuring the reflectance of light (420 to 700 nm) of the cured product of the protective film-forming film, the maximum and minimum values ​​of the reflectance of light (420 to 700 nm) were read. These values ​​are shown in Table 1 together with the wavelength of the light in each case. Furthermore, the difference between these values ​​(difference between the maximum value and the minimum value) was calculated. The results are shown in the column "difference between the maximum value and the minimum value (%)" in Table 1.

[0187] <Measurement of the reflectance of light (420 to 700 nm) of protective film> The reflectance of light (420 to 700 nm) of the protective film-forming film was measured in the same manner as in the above "Measurement of reflectance of light (420 to 700 nm) of cured product of protective film-forming film," except that the protective film-forming film was not thermally cured and was used to measure the reflectance of light (420 to 700 nm) as is.

[0188] <Calculation of the difference between the maximum and minimum reflectance values ​​of the protective film (420 to 700 nm)> When measuring the reflectance of light (420 to 700 nm) of the above protective film-forming film, the maximum and minimum values ​​of the reflectance of light (420 to 700 nm) were read. These values ​​are shown in Table 1 together with the wavelength of the light in each case. Furthermore, the difference between these values ​​(difference between the maximum value and the minimum value) was calculated. The results are shown in the column "difference between the maximum value and the minimum value (%)" in Table 1.

[0189] <Measurement of light (420 to 700 nm) transmittance of cured protective film> The first release film was removed from the protective film-forming film in the laminated film obtained above. Next, the protective film-forming film was heated at 140°C for 2 hours to be thermally cured to form a cured product (protective film). After heating, the cured product of the protective film-forming film was allowed to cool together with the second release film until its temperature reached 23°C. Next, the second release film was removed from the cured product to obtain a single-layer cured product. The light transmittance of this cured product was measured in 1 nm increments in the wavelength range of 380 to 780 nm using a UV-Vis spectrophotometer (Shimadzu Corporation's "UV-VIS-NIR SPECTROPHOTOMETER UV-3600") and an integrating sphere (Shimadzu Corporation's "Integrating Sphere Accessory ISR-3100") Table 1 shows the maximum values ​​obtained in the wavelength range of 420 to 700 nm.

[0190] <Measurement of light transmittance (420-700 nm) of protective film> The light (420 to 700 nm) transmittance of the protective film-forming film was measured in the same manner as in the above-mentioned "Measurement of light (420 to 700 nm) transmittance of the cured product of the protective film-forming film" except that the protective film-forming film was not thermally cured and was used to measure the light (420 to 700 nm) transmittance as it was. The maximum value of the obtained measured values ​​is shown in Table 1.

[0191] <Measurement of peel strength of cured protective film-forming film> In the same manner as in the above-mentioned "measurement of the reflectance of light (420 to 700 nm) of the cured product of the protective film-forming film", the protective film-forming film was attached to the ground surface of the silicon wafer. Furthermore, the second release film was removed from the protective film-forming film after bonding, and the entire area of ​​one side of a 10 mm wide copper foil (thickness 150 μm, length 50 mm, alloy number C1100P, compliant with JIS H 3100) extending from one end in the length direction to a distance of 30 mm was bonded to the exposed surface (other side) of the protective film-forming film using a roller heated to 70° C. at a lamination speed of 0.3 m / min. That is, the remaining area of ​​the copper foil extending in the length direction for a distance of 20 mm was not bonded to the protective film-forming film, and was left as a free, non-bonded portion.

[0192] Next, this laminate of the silicon wafer, the protective film-forming film, and the copper foil was heated at 140° C. for 2 hours to thermally cure the protective film-forming film into a cured product (protective film). Immediately after heating, the laminate of the silicon wafer, the cured product of the protective film-forming film, and the copper foil was allowed to cool to a temperature of 23°C.

[0193] Using a tensile tester (Shimadzu Corporation "AG-IS MS"), the cured product was peeled from the silicon wafer together with the copper foil in the length direction of the copper foil from the non-adhesive portion of the copper foil in an environment of 23°C and 50% relative humidity, so that the surfaces of the cured product and the silicon wafer that had been in contact with each other formed a 90° angle (so-called 90° peeling), and the peel load at this time was measured. The average value of the measured peel loads at a distance of 25 to 45 mm from the end of the non-adhesive portion of the copper foil was calculated, and this average value was used as the peel strength of the cured product of the protective film-forming film to the silicon wafer. The results are shown in Table 1.

[0194] <Evaluation of visibility of light-colored print when printed directly on the protective film> A silicon wafer with a protective film was obtained in the same manner as in the above-mentioned "measurement of the reflectance of light (420 to 700 nm) of the cured product of the protective film-forming film." The obtained silicon wafer with the protective film was allowed to cool to a temperature of 23°C, and then laser printing was performed on the exposed surface of the protective film (the surface opposite the silicon wafer) using a UV laser marker (MD-U1000C manufactured by Keyence Corporation) under the following conditions, thereby printing light-colored characters that were visible to the naked eye. [Laser printing conditions] Laser light wavelength: 355nm Printed characters: ABCDEFGHI Printed character size: height 300 μm x width 200 μm Printed character line width: 35 μm Laser marking speed: 1000mm / s Laser frequency: 300kHz Laser power: 0.48~0.96W

[0195] When the printing on the protective film formed above was observed using a digital microscope (Keyence Corporation, "VHX-7000") under conditions of white balance R = 1.77, G = 1.00, B = 2.31, ring illumination, brightness 100, and shutter speed 1 / 120 sec, the laser output was adjusted so that the R value, G value, and B value in the RGB color system were each within the range of 150 to 160. Therefore, the R value, G value, and B value of the silicon wafer with the protective film on which light-colored characters were printed were each within the range of 150 to 160 when visually observed.

[0196] The print on the formed protective film was visually observed by five observers at a viewing distance (the distance from the printed protective film to the observer's eye) of 15 cm, and the visibility of the light-colored print when printed directly on the protective film was evaluated according to the following criteria. The results are shown in the "Visibility of print when directly printed" column in Table 1. [Evaluation criteria] A: 4 to 5 observers out of 5 could see the print, and the visibility of the light-colored print on the protective film was good. B: Two to three out of five observers could see the print, and the light-colored print on the protective film could be seen. C: 0 to 1 out of 5 observers could see the print, and the visibility of the light-colored print on the protective film was poor.

[0197] <<Manufacturing of composite sheets for forming protective films>> <Production of Pressure-Sensitive Adhesive Composition> An acrylic resin (100 parts by mass) was mixed with a crosslinker (a xylene diisocyanate adduct of trimethylolpropane, "Takenate D110N" manufactured by Mitsui Takeda Chemicals) (20 parts by mass), diluted with methyl ethyl ketone, and stirred at 23°C to produce a pressure-sensitive adhesive composition with a combined concentration of the two components other than methyl ethyl ketone of 25% by mass. The amounts of the two components other than methyl ethyl ketone shown here are the amounts of the target product excluding the solvent. The acrylic resin used here was a (meth)acrylic acid ester copolymer (weight-average molecular weight 600,000) obtained by copolymerizing 2-ethylhexyl acrylate (60 parts by mass), methyl methacrylate (30 parts by mass), and 2-hydroxyethyl acrylate (10 parts by mass).

[0198] <Manufacture of support sheet> A third release film ("SP-PET381031" manufactured by Lintec Corporation, thickness 38 μm) made of polyethylene terephthalate, one side of which had been treated for release by silicone treatment, was used, and the adhesive composition obtained above was applied to the release-treated surface using a knife coater, followed by heating and drying at 100°C for 2 minutes to form a non-energy ray-curable adhesive layer (thickness 5 μm).

[0199] Next, an uncolored polypropylene film (thickness 80 μm, melting point 156°C, surface roughness (Ra) of 0.20 μm on one side (matte side), surface roughness (Ra) of 0.15 μm on the other side (slightly matte side)) was used as the substrate, and the exposed surface of the adhesive layer obtained above (the side opposite the release film side) was attached to the matte side to produce a support sheet with a release film in which the substrate, adhesive layer, and third release film were laminated in this order in the thickness direction.

[0200] The third release film was removed from the support sheet with a release film obtained above, to expose one side of the pressure-sensitive adhesive layer (the side opposite to the substrate side). The protective film-forming film in the laminated film obtained above, which was composed of a first release film provided on one side of the protective film-forming film, and a second release film provided on the other side of the protective film-forming film, was removed from the protective film-forming film, and the exposed surface (one side) of the protective film-forming film thus obtained was attached to the adhesive layer in the support sheet using a roller at room temperature. This resulted in a composite sheet for forming a protective film, which was composed of the support sheet, the protective film-forming film, and the second release film laminated in this order in the thickness direction.

[0201] <<Evaluation of protective film forming films>> <Evaluation of visibility of light-colored print when printed on a protective film through a support sheet> One side of the silicon wafer was ground with a #2000 wheel to prepare a silicon wafer (thickness 350 μm) having a ground surface. The second release film was removed from the protective film-forming film in the composite sheet for forming a protective film obtained above, and the exposed surface of the protective film-forming film was attached to the ground surface of the silicon wafer using a roller heated to 70 ° C. at a lamination speed of 0.3 m / min.

[0202] The silicon wafer with the composite sheet for forming a protective film obtained in this way was heated at 140°C for 2 hours to thermally cure the protective film-forming film into a cured product (forming a protective film), thereby obtaining a silicon wafer with a protective film and a support sheet.

[0203] The obtained silicon wafer with protective film was allowed to cool together with the support sheet until its temperature reached 23°C. Then, using a UV laser marker (Keyence Corporation, "MD-U1000C"), pale-colored characters were visually printed through the support sheet on the surface of the protective film facing the support sheet (the surface opposite the silicon wafer) under the same conditions as when printing directly onto the above-mentioned protective film.

[0204] After printing, the support sheet was removed from the protective film, and the printing on the protective film was observed using a digital microscope (Keyence Corporation's "VHX-7000") in the same manner as when printing was performed directly on the protective film. The laser output was adjusted so that the R value, G value, and B value in the RGB color system were each within the range of 150 to 160 before printing. Therefore, the R value, G value, and B value of the silicon wafer with the protective film on which light-colored characters were printed were each within the range of 150 to 160 when visually observed.

[0205] The print on the formed protective film was evaluated in the same manner as when printing directly on the protective film described above, and the visibility of the light-colored print when printed on the protective film through a support sheet was evaluated. The results are shown in the column "Visibility of print when printed through a support sheet" in Table 1.

[0206] <<Production of protective film-forming films and composite sheets for protective film-forming, and evaluation of protective film-forming films>> [Examples 2 to 6, Comparative Examples 1 to 4] A protective film-forming film was produced in the same manner as in Example 1, except that the blending amounts of the components of the protective film-forming composition (III) or the types and blending amounts of the components were changed. The types and contents of the components contained in these protective film-forming films are shown in Tables 1 and 2. In addition, the notation "-" in the column of the components contained in the protective film-forming film means that the protective film-forming film does not contain that component.

[0207] Furthermore, composite sheets for forming a protective film were produced in the same manner as in Example 1, except that these protective film-forming films were used. Using these protective film-forming films themselves or composite sheets for forming a protective film, the protective film-forming films were evaluated in the same manner as in Example 1. The results are shown in Tables 1 and 2.

[0208] [Table 1]

[0209] [Table 2]

[0210] As is clear from the above results, in Examples 1 to 6, the reflectance of the cured product of the protective film-forming film to light (420 to 700 nm) was 57.8% or more. Even though these protective films (cured products) can make the protective film-attached workpiece less noticeable on a white substrate, the visibility of light-colored printing on these protective films was good in both direct printing and printing through a support sheet. The higher the reflectance of the cured product of the protective film-forming film to light (420 to 700 nm), the higher the visibility of light-colored printing on the protective film tends to be. Examples 4 to 6 had the reflectance of 67.5% or more, and were particularly excellent in visibility of light-colored printing.

[0211] Furthermore, in Examples 1 to 6, the difference between the maximum and minimum reflectance values ​​of the cured protective film-forming film for light (420 to 700 nm) was 14.7% or less, and these protective films had excellent properties for making the workpiece with the protective film less noticeable on a white substrate. The protective film-forming films of Examples 1 to 6 contained a white pigment, and in these protective film-forming films, the content of the white pigment relative to the total mass of the protective film-forming film was 8 mass % or more.

[0212] In Examples 1 to 6, the maximum and minimum values ​​of the reflectance of the protective film-forming film to light (420 to 700 nm) were approximately equal to the maximum and minimum values ​​of the reflectance of the cured product of the protective film-forming film to light (420 to 700 nm), and the wavelength of the light at that time was the same. In other words, the light reflection characteristics of these protective film-forming films hardly changed before and after curing.

[0213] In Examples 1 to 6, the maximum light transmittance (420 to 700 nm) of the protective film-forming film was approximately equal to the maximum light transmittance (420 to 700 nm) of the cured product of the protective film-forming film. In other words, the light transmittance characteristics of these protective film-forming films were almost unchanged before and after curing.

[0214] In Examples 1 to 6, the color tone of both sides of the protective film-forming film was uniform, which was advantageous in that the light-colored print of the protective film could be clearly seen.

[0215] In Examples 1 to 6, the peel strength of the cured protective film-forming film was 7800 mN / 10 mm or more, and these protective film-forming films had a high effect of suppressing unintended peeling between the protective film and the workpiece, and had desirable properties. In the protective film-forming films of Examples 1 to 6, the content of the filler (E) relative to the total mass of the protective film-forming film was 55.8 mass % or less.

[0216] In contrast, in Comparative Examples 1 to 4, the minimum reflectance of the cured protective film-forming film for light (420 to 700 nm) was 53.7% or less, and the visibility of the light-colored print on these protective films was poor in both direct printing and printing through a support sheet.

[0217] In Comparative Example 4, the content of white pigment in the protective film-forming film relative to the total mass of the protective film-forming film was higher than in Comparative Examples 1 to 3, but the protective film-forming film of Comparative Example 4 contained colorant (J)-2 (bright red dye).

[0218] In Comparative Example 1, the peel strength of the cured protective film-forming film was 6700 mN / 10 mm, and this protective film-forming film had a low effect of suppressing unintended peeling between the protective film and the workpiece. In the protective film-forming film of Comparative Example 1, the content ratio of the filler (E) relative to the total mass of the protective film-forming film was 60.1 mass %, which was high. [Industrial Applicability]

[0219] The present invention can be used as a protective film for protecting a workpiece to be mounted on a circuit board. [Explanation of symbols]

[0220] 101: Composite sheet for forming protective film, 10: Support sheet, 10a: One side (first side) of support sheet, 11: Base material, 12: Pressure-sensitive adhesive layer, 13: Protective film-forming film, 13a: One side (first side) of protective film-forming film, 13b: Other side (second side) of protective film-forming film, 13': Protective film, 130': Protective film after cutting, 9: Semiconductor wafer, 90: Semiconductor chip, 9b: Back side of semiconductor wafer, 91: Semiconductor chip with protective film

Claims

1. A protective film-forming film for forming a protective film on any part of a workpiece obtained by processing a workpiece, When the protective film-forming film is curable, the reflectance of the cured product of the protective film-forming film in the entire wavelength range of 420 to 700 nm is more than 55%, When the protective film-forming film is non-curable, the protective film-forming film has a reflectance of more than 55% for light in the entire wavelength range of 420 to 700 nm.

2. When the protective film-forming film is curable, the transmittance of light in the entire wavelength range of 420 to 700 nm of the cured product of the protective film-forming film is 40% or less, The protective film-forming film according to claim 1, wherein when the protective film-forming film is non-curable, the transmittance of the protective film-forming film for light in the entire wavelength range of 420 to 700 nm is 40% or less.

3. The protective film-forming film according to claim 1 or 2, wherein the protective film-forming film contains a white pigment.

4. When the protective film-forming film is curable, the difference between the maximum value and the minimum value of the reflectance of the cured product of the protective film-forming film in the wavelength range of 420 to 700 nm is 20% or less, When the protective film-forming film is non-curable, the difference between the maximum and minimum values ​​of the reflectance of the protective film-forming film in the wavelength range of 420 to 700 nm is 20% or less. The protective film-forming film according to claim 1 or 2.

5. One surface of the protective film-forming film is attached to the ground surface of the silicon wafer, and a copper foil having a width of 10 mm is attached to the other surface of the protective film-forming film after attachment, thereby producing a laminate of the silicon wafer, the protective film-forming film, and the copper foil; When the protective film-forming film is curable, the protective film-forming film in the laminate is cured to form a cured product, and the cured product is peeled off from the silicon wafer together with the copper foil in the length direction of the copper foil so that the surfaces of the cured product and the silicon wafer that were in contact with each other form an angle of 90° under an environment of a temperature of 23°C and a relative humidity of 50%, and the peel strength of the cured product measured when peeled off is 7000 mN / 10 mm or more, 3. The protective film-forming film according to claim 1 or 2, wherein when the protective film-forming film is non-curable, the peel strength of the protective film-forming film measured when the protective film-forming film is peeled off from the silicon wafer together with the copper foil in the length direction of the copper foil so that the surfaces of the protective film-forming film and the silicon wafer that were in contact with each other form an angle of 90° in an environment of 23°C and 50% relative humidity is 7000 mN / 10 mm or more.

6. A method for manufacturing a workpiece with a protective film using the protective film-forming film according to claim 1 or 2, When the protective film-forming film is curable, the cured product of the protective film-forming film is the protective film. When the protective film-forming film is non-curable, the protective film-forming film after being attached to a workpiece is the protective film. The manufacturing method includes a pasting step of pasting the protective film-forming film to the workpiece; a printing step of printing on the protective film-forming film or the protective film after the attaching step; a processing step of processing the workpiece after the attaching step to produce the workpiece; a cutting step of cutting the protective film-forming film or the protective film after the attaching step, If the protective film-forming film is curable, the method for manufacturing a workpiece with a protective film further includes a curing process for forming the protective film by curing the protective film-forming film after the attaching process.

7. The method for manufacturing a workpiece with a protective film according to claim 6, wherein in the printing step, printing in a light color is performed on the protective film-forming film or the protective film.

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