Protective film forming film and method for manufacturing workpiece process with

Abstract

The present invention relates to a protective film-forming film for forming a protective film at any position of a workpiece processed object obtained by processing a workpiece, and when the protective film-forming film is curable, the reflectance of light in the full wavelength range of 420-700 nm of a cured object of the protective film-forming film is 22% or more, and the reflectance of light in the full wavelength range of 420-700 nm of the cured object of the protective film-forming film is 22% or more. When the protective film-forming film is curable, the absorptivity of light at a wavelength of 532 nm and / or 1064 nm of the cured product is 7% or more, when the protective film-forming film is non-curable, the reflectance of light at a wavelength range of 420-700 nm of the protective film-forming film is 22% or more, and the absorptivity of light at a wavelength of 532 nm and / or 1064 nm of the protective film-forming film is 7% or more. As a result, it is possible to provide a protective film forming film capable of sufficiently imparting deep-color lettering to a protective film, even if the protective film is a protective film having a high light reflectance for making a workpiece workpiece with a protective film inconspicuous on a white substrate.

Description

Technical Field

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

[0002] This application claims priority based on Japanese Patent Application No. 2023-165209 filed in Japan on September 27, 2023, Japanese Patent Application No. 2024-113930 filed in Japan on July 17, 2024, and Japanese Patent Application No. 2024-122280 filed in Japan on July 29, 2024, and their contents are cited herein. Background Art

[0003] In a wafer such as a semiconductor wafer or an insulator wafer, a circuit is formed on one surface (circuit surface), and sometimes a protruding electrode such as a bump is further provided on the surface (circuit surface). Such a wafer is divided into chips, and the protruding electrodes are connected to connection pads on a circuit substrate, thereby being mounted on the circuit substrate.

[0004] In such a wafer or chip, a protective film is sometimes used to protect the surface (back surface) opposite to the circuit surface in order to suppress the occurrence of damage such as cracks.

[0005] In addition, in the process of manufacturing a semiconductor device, a semiconductor device panel described later is used as a workpiece, and in order to suppress the occurrence of warping or cracks in the panel, a protective film may be used to protect any part of the panel.

[0006] In such a case, for example, a protective film forming film for forming a protective film is attached to a target position of a workpiece such as the back side of a wafer, and then the workpiece is processed to form a workpiece processed object, and the protective film forming film is cured as needed, and the protective film forming film or the protective film is cut to manufacture a workpiece processed object with a protective film having a workpiece processed object and a protective film provided at any position of the workpiece processed object. As an example of a workpiece processed object with a protective film, a semiconductor chip with a protective film having a semiconductor chip and a protective film provided on the back side of the semiconductor chip can be cited.

[0007] As a circuit substrate for a light emitting device, a white substrate is sometimes used. In this case, in order to make the workpiece with a protective film inconspicuous on the white substrate, it is preferred to use a protective film with a high light reflectivity. As a protective film-forming film capable of forming such a protective film, a protective film-forming film having curability and a reflectivity of light of the full wavelength range of 400 to 700 nm of its cured product of 20% or more is disclosed, and a non-curable protective film-forming film having a reflectivity of light of the full wavelength range of 400 to 700 nm of 20% or more is disclosed (see patent document 1). The non-curable protective film-forming film itself functions as a protective film.

[0008] Prior art literature

[0009] Patent Literature

[0010] Patent Document 1: Japanese Patent Application Publication No. 2023-043538 Summary of the invention

[0011] 1. Technical issues to be resolved

[0012] Usually, printing for identifying the protective film in the workpiece with a protective film is applied. When the protective film forming film is curable, the cured product of the protective film forming film (i.e., the protective film) can be printed, and the protective film forming film before curing can also be printed. Printing is usually performed by irradiating a laser with a wavelength of 532nm or 1064nm. However, in a protective film forming film or a protective film with high light reflectivity, the absorption of light with a wavelength of 532nm or 1064nm is suppressed. Therefore, especially when the printing applied by a laser of such a wavelength is tiny text, it is difficult to print in a dark color to a degree that can be fully recognized. In this regard, the protective film forming film disclosed in Patent Document 1 does not solve such a problem as a technical problem, and it is not clear whether this problem can be solved.

[0013] An object of the present invention is to provide a protective film forming film, which is a protective film forming film for forming the protective film in a workpiece processed with a protective film, wherein the workpiece processed with a protective film comprises a workpiece processed and a protective film arranged at any position of the workpiece processed. Even if the workpiece processed with the protective film is a protective film with a high light reflectivity for making the workpiece processed with the protective film inconspicuous on a white substrate, dark printing can be fully applied to the protective film.

[0014] (II) Technical solution

[0015] In order to solve the above-mentioned technical problems, the present invention adopts the following structure.

[0016] (1) A protective film-forming film, which is a protective film-forming film used to form a protective film at any position of a workpiece processed by processing the workpiece, wherein when the protective film-forming film is curable, the reflectivity of the cured product of the protective film-forming film is 22% or more for light in the full wavelength range of 420 to 700 nm, and the absorptivity of the cured product for light at any one of wavelengths of 532 nm and 1064 nm or both is 7% or more, and when the protective film-forming film is non-curable, the reflectivity of the protective film-forming film is 22% or more for light in the full wavelength range of 420 to 700 nm, and the absorptivity of the protective film-forming film for light at any one of wavelengths of 532 nm and 1064 nm or both is 7% or more.

[0017] (2) A protective film-forming film according to (1), wherein, when the protective film-forming film is curable, the transmittance of the cured product of the protective film-forming film in the full wavelength range of 420 to 700 nm is 40% or less, and when the protective film-forming film is non-curable, the transmittance of the protective film-forming film in the full wavelength range of 420 to 700 nm is 40% or less.

[0018] (3) The protective film-forming film according to (1) or (2), wherein the protective film-forming film contains a white pigment.

[0019] (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 the reflectivity of the cured product of the protective film-forming film for light in the wavelength range of 420 to 700 nm is less than 20%, and when the protective film-forming film is non-curable, the difference between the maximum and minimum values ​​of the reflectivity of the cured product of the protective film-forming film for light in the wavelength range of 420 to 700 nm is less than 20%.

[0020] (5) The protective film-forming film according to any one of (1) to (4), wherein the protective film-forming film contains a carbon material, and the content of the carbon material in the protective film-forming film is 0.1% by mass or less relative to the total mass of the protective film-forming film.

[0021] (6) A method for manufacturing a workpiece processed product with a protective film, which is a method for manufacturing a workpiece processed product with a protective film using the protective film-forming film described in any one of (1) to (5), wherein when the protective film-forming film is curable, the cured product of the protective film-forming film is the protective film, and when the protective film-forming film is non-curable, the protective film-forming film after being attached to the workpiece is the protective film. In the manufacturing method, the protective film-forming film is attached to the workpiece, and the protective film-forming film or the protective film after being attached to the workpiece is printed. The workpiece processed product is manufactured by processing the workpiece after the protective film-forming film is attached, and the protective film-forming film or the protective film after being attached to the workpiece is cut off. When the protective film-forming film is curable, the protective film-forming film after being attached to the workpiece is further cured to form the protective film.

[0022] (III) Beneficial effects

[0023] According to the present invention, a protective film forming film can be provided, which is a protective film forming film for forming the protective film in a workpiece processed with a protective film, wherein the workpiece processed with a protective film comprises a workpiece processed and a protective film arranged at any position of the workpiece processed. Even if the workpiece processed with the protective film is a protective film with a high light reflectivity for making the workpiece processed with the protective film inconspicuous on a white substrate, dark printing can be sufficiently applied to the protective film. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a cross-sectional view schematically showing an example of a protective film-forming film according to an embodiment of the present invention.

[0025] Description of Reference Numerals

[0026] 13: protective film-forming film; 13a: one surface (first surface) of the protective film-forming film; 13b: the other surface (second surface) of the protective film-forming film; 151: first release film; 152: second release film. DETAILED DESCRIPTION

[0027] ◇Protective film forming film

[0028] A protective film-forming film according to one embodiment of the present invention is a protective film-forming film used to form a protective film at any position of a workpiece processed by processing the workpiece. When the protective film-forming film is curable, the reflectivity of the cured product of the protective film-forming film in the full wavelength range of 420 to 700 nm is 22% or more, and the absorptivity of the cured product at any one or both of the wavelengths of 532 nm and 1064 nm is 7% or more. When the protective film-forming film is non-curable, the reflectivity of the protective film-forming film in the full wavelength range of 420 to 700 nm is 22% or more, and the absorptivity of the protective film-forming film at any one or both of the wavelengths of 532 nm and 1064 nm is 7% or more.

[0029] The protective film-forming film of the present embodiment can constitute a composite sheet for protective film formation by being laminated with a supporting sheet as described later, for example.

[0030] The protective film-forming film of the present embodiment can protect the workpiece by being attached to any position of the workpiece and finally forming a protective film.

[0031] The protective film-forming film of the present embodiment is soft and can be attached to a workpiece before being processed into a workpiece.

[0032] That is, by using the protective film-forming film of the present embodiment or the composite sheet for protective film-forming having the protective film-forming film, a workpiece with a protective film having a workpiece and a protective film provided at any position of the workpiece can be manufactured. Furthermore, before manufacturing the workpiece with a protective film, by using the protective film-forming film, a workpiece with a protective film-forming film having a workpiece and a protective film-forming film provided at any position of the workpiece can be manufactured.

[0033] In the present embodiment, the workpiece processed object refers to a processed object obtained by processing a workpiece.

[0034] Examples of the workpiece include a wafer and a semiconductor device panel.

[0035] Examples of the wafer include semiconductor wafers made of elemental semiconductors such as silicon, germanium, and selenium, or compound semiconductors such as GaAs, GaP, InP, CdTe, ZnSe, and SiC; and insulator wafers made of insulators such as sapphire and glass.

[0036] For example, when the workpiece is a semiconductor wafer, a semiconductor chip can be cited as the workpiece to be processed. One surface of these wafers is a circuit surface on which a circuit is formed, and the surface opposite to the circuit surface is referred to as the "back surface" in this specification.

[0037] The same is true for chips produced by dividing a wafer by dicing or the like, and the surface of the chip opposite to the circuit surface on which the circuit is formed is referred to as the "back surface".

[0038] Both the circuit surface of the wafer and the circuit surface of the chip are provided with protruding electrodes such as bumps and small pillars.

[0039] The semiconductor device panel is a device used in the manufacturing process of the semiconductor device. As a specific example, there can be listed a semiconductor device panel composed of a semiconductor device in which one or more electronic components are sealed with a sealing resin, and a plurality of such semiconductor devices are arranged in a plane in an area of ​​a circular, rectangular or other shape.

[0040] The workpiece is preferably a chip (e.g., a semiconductor chip) in a substrate device, or a chip in a light-emitting device. Such a chip may include, for example, a WLCSP (wafer-level chip-scale package) for current control.

[0041] The light-emitting device can be any device having 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 having a light-emitting element, a substrate device having a mini LED element, and a substrate device having a micro LED element.

[0042] In this specification, a "substrate device" refers to a device in which a workpiece with a protective film is flip-chip bonded to a connection pad on a circuit substrate on a protruding electrode on a circuit surface. For example, when a semiconductor wafer is used as a workpiece, a semiconductor device having a semiconductor chip with a protective film can be listed as a substrate device.

[0043] The circuit board in the light emitting device has a high reflectivity of visible light and is mostly white. For example, a typical white circuit board includes a white circuit board whose light reflectivity in the entire wavelength range of 420 to 700 nm is 30% or more.

[0044] In contrast, the protective film obtained by using the protective film forming film of this embodiment has a high reflectivity of visible light, and the protective film is preferably white. Therefore, as described later, a workpiece with a protective film having such a protective film is not conspicuous on a white substrate (circuit substrate) in a light-emitting device, and the design of the device having the workpiece with a protective film is high.

[0045] 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 curing, or may function as a protective film in an uncured state.

[0046] The curable protective film-forming film may be either thermosetting or energy-ray-curable, or may have both thermosetting and energy-ray-curable properties.

[0047] In this specification, "energy ray" refers to a ray having energy quantum among electromagnetic waves or charged particle beams. Examples of energy ray include ultraviolet rays, radiation, electron beams, and the like.

[0048] In the present 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 by irradiation with energy rays.

[0049] In this specification, "non-curable" means a property that does not cure by any means such as heating or irradiation with energy rays. The non-curable protective film-forming film can be regarded as a protective film after being provided (formed) on a target object.

[0050] <<Reflectivity of light (420~700nm)>>

[0051] When the protective film-forming film of the present embodiment is curable, the reflectivity of the cured product of the protective film-forming film in the entire wavelength range of 420 to 700 nm is 22% or more. In other words, the minimum value of the reflectivity of the cured product of the protective film-forming film in the wavelength range of 420 to 700 nm is 22% or more.

[0052] When the protective film-forming film of this embodiment is non-curable, the reflectivity of the protective film-forming film for light in the entire wavelength range of 420 to 700 nm is greater than 22%. In other words, the minimum value of the reflectivity of the protective film-forming film for light in the wavelength range of 420 to 700 nm is greater than 22%.

[0053] In this specification, “light in the entire wavelength range of 420 to 700 nm” may be referred to as “light (420 to 700 nm)”.

[0054] In the protective film obtained by forming a protective film having the characteristic of the reflectivity of light (420~700nm) as described above, the absorption of visible light is suppressed compared with usual, and the protective film is preferably white. Therefore, the workpiece with such a protective film is not conspicuous on the white substrate in the light-emitting device, and the design of the device with the workpiece with the protective film is high. In addition, even if the protective film has a high light reflectivity in order to make the workpiece with the protective film inconspicuous on the white substrate, as long as it is a protective film formed by forming a protective film having the characteristic of the absorbency of light as described above, dark printing can be fully applied.

[0055] That is, in this embodiment, the workpiece is preferably a chip in a light-emitting device, and may also be a semiconductor chip in a light-emitting device.

[0056] In this specification, unless otherwise specified, "printing on a protective film" means printing on a curable or non-curable protective film-forming film. When the protective film-forming film is curable, a printed protective film is obtained by further curing the printed protective film-forming film or by printing on the protective film.

[0057] In this specification, unless otherwise specified, the cured product of the protective film-forming film means a cured product having a sufficiently high degree of curing, and is synonymous with the protective film.

[0058] In this specification, unless otherwise specified, when the protective film-forming film is curable, “the reflectivity of light (420~700nm)” means “the reflectivity of light (420~700nm) of the cured product of the protective film-forming film”; and when the protective film-forming film is non-curable, “the reflectivity of light (420~700nm)” means “the reflectivity of light (420~700nm) of the protective film-forming film”.

[0059] As described in the examples below, the reflectivity of light (420-700 nm) can be measured by measuring the amount of total light reflected by the protective film-forming film or its cured product and a standard plate made of barium sulfate, respectively, and finding the ratio of the measured value of the protective film-forming film or its cured product to the measured value of the standard plate (i.e., relative total light reflectivity). And, the maximum value and the minimum value thereof can be respectively adopted as the maximum value and the minimum value of the reflectivity of light (420-700 nm) described below.

[0060] The reflectivity of light (420-700 nm) can be 22% or more, for example, it can be any range of greater than 40%, greater than 50%, greater than 55%, greater than 60%, and greater than 70%. The higher the reflectivity of light (420-700 nm), the less conspicuous the workpiece with the protective film is on the white substrate in the light-emitting device.

[0061] The upper limit of the reflectivity of light (420-700 nm) is not particularly limited. For example, a protective film-forming film having a reflectivity of light (420-700 nm) of 95% or less can be more easily realized. In other words, the maximum value of the reflectivity of light (420-700 nm) can be 95% or less.

[0062] The reflectivity of light in the full wavelength range of 420 to 700 nm of the curable protective film-forming film in the uncured state (i.e., the protective film-forming film itself) is preferably within the same range as the reflectivity of light (420 to 700 nm) of the cured product of the above-mentioned protective film-forming film (e.g., 22% or more).

[0063] For the protective film-forming film and its cured product, the reflectivity of light (420~700nm) can be adjusted, for example, by adjusting the type and content of the components contained in the protective film-forming film. In particular, by making the protective film-forming film contain a colorant described later (a colorant (J) in a thermosetting protective film-forming film, a colorant in an energy-ray-curable protective film-forming film, and a non-curable protective film-forming film), the reflectivity of light (420~700nm) of the protective film-forming film and its cured product 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 reflectivity of light (420~700nm) of the protective film-forming film and its cured product can be adjusted by its particle size. For example, in the protective film-forming film, a substance with high whiteness is used as a colorant, and by increasing its content, the reflectivity of light (420~700nm) of the protective film-forming film and its cured product can be increased. For example, when the protective film-forming film contains a white pigment, the reflectivity of the protective film-forming film and its cured product with respect to light (420 to 700 nm) can be increased more easily.

[0064] That is, the protective film-forming film of the present embodiment preferably contains a white pigment.

[0065] The details of the white pigment will be described later.

[0066] When the protective film-forming film contains a white pigment, the content of the white pigment in the protective film-forming film is preferably 0.8% by mass or more relative to the total mass of the protective film-forming film, and may be, for example, any of 3% by mass or more, 7% by mass or more, 15% by mass or more, 25% by mass or more, and 35% by mass or more. By making the ratio within the above range, the reflectivity of the protective film-forming film and its cured product of light (420-700 nm) can be further improved.

[0067] On the other hand, from the viewpoint of improving the film-forming property, flexibility, toughness, ductility, and the like of the protective film-forming film, the ratio is preferably 60% by mass or less.

[0068] The ratio of the content of the white pigment shown here is applied to the thermosetting protective film-forming film, the energy ray-curable protective film-forming film, and the non-curable protective film-forming film described later.

[0069] The content of the white pigment in the protective film-forming film can be appropriately adjusted according to the type of the protective film-forming film.

[0070] In the protective film obtained by forming a film using a protective film having the reflectivity characteristics of light (420 to 700 nm) as described above, the absorption of visible light is suppressed compared to normal, and the protective film is preferably white. Therefore, a workpiece with such a protective film is not conspicuous on a white substrate in a light-emitting device, and the design of the device with the workpiece with the protective film is high.

[0071] <<Difference between the maximum and minimum reflectance of light (420~700nm)>>

[0072] When the protective film-forming film of the present embodiment is curable, the difference between the maximum value and the minimum value of the reflectance of light (420 to 700 nm) of the cured product of the protective film-forming film is preferably 20% or less.

[0073] When the protective film-forming film of the present embodiment is non-curable, the difference between the maximum value and the minimum value of the reflectance of light (420 to 700 nm) of the protective film-forming film is preferably 20% or less.

[0074] The smaller the difference is, the reflectivity is neither high nor low only in a specific narrow wavelength range, which means that it is difficult to form an appearance such as bluish white or reddish white, so the protective film has a higher property of making the workpiece with the protective film inconspicuous on the white substrate.

[0075] From the perspective of further enhancing the above-mentioned effect, regardless of whether the protective film forming film is curable or not, the difference between the maximum and minimum values ​​of the reflectance of light (420~700nm) is more preferably 16% or less, for example, it can be any range of 12% or less, 10% or less, and 6% or less.

[0076] The lower limit of the difference is not particularly limited. For example, a protective film-forming film having a difference of 2% or more can be more easily realized.

[0077] In one embodiment, the difference may be, for example, any range of 2-20%, 2-16%, 2-12%, 2-10% and 2-6%. However, these ranges are only examples of the difference.

[0078] The difference between the maximum and minimum values ​​of the reflectivity of light in the wavelength range of 420 to 700 nm of the curable protective film-forming film in the uncured state (i.e., of the protective film-forming film itself) is preferably within the same range (e.g., less than 20%) as the difference between the maximum and minimum values ​​of the reflectivity of light (420 to 700 nm) of the cured product of the above-mentioned protective film-forming film.

[0079] <<Absorption rate of light (532nm)>>

[0080] When the protective film-forming film of the present embodiment is curable, and the absorptivity of the cured product at a wavelength of 1064 nm is less than 7%, the absorptivity of the cured product at a wavelength of 532 nm is 7% or more.

[0081] When the protective film-forming film of the present embodiment is non-curable, when the absorptivity of the protective film-forming film at a wavelength of 1064 nm is less than 7%, the absorptivity of the protective film-forming film at a wavelength of 532 nm is 7% or more.

[0082] In this specification, “light with a wavelength of 532 nm” may be referred to as “light (532 nm)”, and “light with a wavelength of 1064 nm” may be referred to as “light (1064 nm)”.

[0083] Regardless of whether the protective film-forming film is curable or not, the protective film-forming film having the characteristic of light (532nm) absorption rate as described above or the protective film (cured product) obtained by using the protective film-forming film, although the protective film has a high light reflectivity, when the protective film-forming film or its cured product is laser-printed by irradiating the protective film-forming film or its cured product with a laser having a wavelength of 532nm (sometimes referred to as "laser (532nm)" in this specification), unlike in the past, the laser (532nm) is moderately absorbed by the protective film-forming film or its cured product, so that even tiny printing can be printed in a sufficiently dark color that can be seen.

[0084] In this specification, unless otherwise specified, when the protective film-forming film is curable, "light (532 nm) absorptivity" means "light (532 nm) absorptivity of a cured product of the protective film-forming film", and when the protective film-forming film is non-curable, "light (532 nm) absorptivity" means "light (532 nm) absorptivity of the protective film-forming film". These meanings are the same as "light (1064 nm) absorptivity".

[0085] In this specification, similar to the case of “laser with a wavelength of 532 nm”, “laser with a wavelength of 1064 nm” described later may be referred to as “laser (1064 nm)”.

[0086] When the absorptivity of light (1064 nm) is less than 7%, in order to further enhance the above-mentioned effect, the absorptivity of light (532 nm) may be, for example, any range of 7.8% or more, 8.5% or more, 9.2% or more, and 10% or more.

[0087] When the protective film-forming film of the present embodiment is curable, the absorptivity of the cured product of the protective film-forming film at light (532 nm) is not particularly limited when the absorptivity of the cured product at light (1064 nm) is 7% or more.

[0088] When the protective film-forming film of the present embodiment is non-curable, the absorptivity of the protective film-forming film for light (1064 nm) is not particularly limited as long as the absorptivity of the protective film-forming film for light (532 nm) is 7% or more.

[0089] When the absorption rate of light (1064nm) is greater than 7%, the absorption rate of light (532nm) can be, for example, any range of greater than 2%, greater than 10%, greater than 18% and greater than 26%. For example, similar to the case where the absorption rate of light (1064nm) is less than 7%, it can be any range of greater than 7%, greater than 7.8%, greater than 8.5%, greater than 9.2% and greater than 10%.

[0090] In particular, when the absorption rate of light (532nm) and the absorption rate of light (1064nm) are both above 7%, no matter which of the laser (532nm) and the laser (1064nm) is used to perform laser printing on the protective film forming film or its cured product, even tiny prints can be printed in a sufficiently dark color that can be seen.

[0091] Regardless of whether the light (1064 nm) absorption rate is 7% or more, the light (532 nm) absorption rate is preferably 34% or less. Such a protective film-forming film can be realized more easily.

[0092] The absorptivity of light at a wavelength of 532 nm of the curable protective film forming film in an uncured state (i.e., of the protective film forming film itself) is preferably within the same range (e.g., greater than 7% or greater than 2%) as the absorptivity of light (532 nm) of the cured product of the above-mentioned protective film forming film.

[0093] The light (532 nm) absorptivity of the protective film-forming film or its cured product can be calculated using the measured values ​​of the light (532 nm) reflectivity and the light (532 nm) transmittance of the protective film-forming film or its cured product measured by a known method.

[0094] For example, the absorptivity of the cured product of the protective film-forming film at 532 nm can be calculated according to the following formula (i).

[0095] [Absorption rate (%) of the cured product of the protective film forming film at light (532 nm)] = 100 - ([Reflection rate (%) of the cured product of the protective film forming film at light (532 nm)] + [Transmittance (%) of the cured product of the protective film forming film at light (532 nm)]) (i)

[0096] Furthermore, regardless of whether the protective film forming film is curable or not, the absorbance of the light (532nm) of the protective film forming film can be calculated in the following manner: in the formula (i), the measured value of the reflectance of the light (532nm) of the protective film forming film is used instead of the measured value of the reflectance of the light (532nm) of the cured product, and the measured value of the transmittance of the light (532nm) of the protective film forming film is used instead of the measured value of the transmittance of the light (532nm) of the cured product.

[0097] <<Absorption rate of light (1064nm)>>

[0098] When the protective film-forming film of the present embodiment is curable, and the absorptivity of the cured product at a wavelength of 532 nm is less than 7%, the absorptivity of the cured product at a wavelength of 1064 nm is 7% or more.

[0099] When the protective film-forming film of the present embodiment is non-curable, when the absorptivity of the protective film-forming film at a wavelength of 532 nm is less than 7%, the absorptivity of the protective film-forming film at a wavelength of 1064 nm is 7% or more.

[0100] Regardless of whether the protective film forming film is curable or not, the protective film forming film having the above-mentioned light (1064nm) absorption rate characteristics or the protective film (cured product) obtained by using the protective film forming film is suitable for printing by irradiating laser (1064nm) even if the light reflectivity of the protective film is high. That is, the laser (1064nm) is moderately absorbed by such a protective film forming film or its cured product, and even if it is a tiny printing, it can be printed with a sufficiently dark color that can be recognized.

[0101] When the absorptivity of light (532 nm) is less than 7%, in order to further enhance the above-mentioned effect, the absorptivity of light (1064 nm) may be, for example, any range of 7.5% or more, 8% or more, 8.5% or more, and 9% or more.

[0102] When the protective film-forming film of the present embodiment is curable, the absorptivity of the cured product of the protective film-forming film at light (1064 nm) is not particularly limited when the absorptivity of the cured product at light (532 nm) is 7% or more.

[0103] When the protective film-forming film of the present embodiment is non-curable, the absorptivity of the protective film-forming film for light (532 nm) is not particularly limited as long as the absorptivity of the protective film-forming film for light (1064 nm) is 7% or more.

[0104] When the absorption rate of light (532nm) is greater than 7%, the absorption rate of light (1064nm) can be, for example, any range of greater than 2%, greater than 10%, greater than 18% and greater than 26%. For example, similar to the above-mentioned case where the absorption rate of light (532nm) is less than 7%, it can be any range of greater than 7%, greater than 7.5%, greater than 8%, greater than 8.5% and greater than 9%.

[0105] Regardless of whether the light (532 nm) absorption rate is 7% or more, the light (1064 nm) absorption rate is preferably 30% or less. Such a protective film-forming film can be more easily realized.

[0106] The absorptivity of light at a wavelength of 1064 nm of the curable protective film-forming film in an uncured state (i.e., of the protective film-forming film itself) is preferably within the same range (e.g., greater than 7% or greater than 2%) as the absorptivity of light (1064 nm) of the cured product of the protective film-forming film.

[0107] The absorptivity of light (1064 nm) of the protective film-forming film or its cured product can be calculated by, for example, the same method as the absorptivity of light (532 nm) of the protective film-forming film or its cured product described above, except that the measurement wavelength is 1064 nm instead of 532 nm.

[0108] In the protective film-forming film and its cured product, the light (532nm) absorptivity and the light (1064nm) absorptivity can be adjusted, for example, by adjusting the type and content of the components contained in the protective film-forming film. In particular, by making the protective film-forming film into a protective film-forming film containing a component as a light absorber in the colorant described later (the colorant (J) in the thermosetting protective film-forming film, the colorant in the energy-ray-curable protective film-forming film and the non-curable protective film-forming film), the light (532nm) absorptivity and the light (1064nm) absorptivity of the protective film-forming film and its cured product can be adjusted by adjusting the type and content of the light absorber in the protective film-forming film. For example, in the protective film-forming film, the light (532nm) absorptivity and the light (1064nm) absorptivity can be increased by increasing the content of the light absorber.

[0109] That is, the protective film-forming film of the present embodiment preferably contains a light absorber.

[0110] The light absorber will be described in detail later.

[0111] When the protective film-forming film contains a light absorber, the content of the light absorber in the protective film-forming film is preferably 0.005% by mass or more, more preferably 0.01% by mass or more, and for example, it may be any range of 0.1% by mass or more and 0.3% by mass or more. By making the ratio above the lower limit, the light (532nm) absorptivity and the light (1064nm) absorptivity of the protective film-forming film and its cured product can be further improved.

[0112] On the other hand, the ratio is preferably 0.7 mass % or less, for example, 0.1 mass % or less. By setting the ratio below the upper limit, the reflectivity of the protective film-forming film and its cured product to light (420-700 nm) can be further increased.

[0113] The ratio of the content of the light absorber shown here is applied to the thermosetting protective film-forming film, the energy ray-curable protective film-forming film, and the non-curable protective film-forming film described later.

[0114] When the protective film-forming film contains a carbon material as a light absorber, the content of the carbon material in the protective film-forming film is preferably 0.005% by mass or more, for example, 0.008% by mass or more relative to the total mass of the protective film-forming film. By making the ratio above the lower limit, the light (532nm) absorptivity and the light (1064nm) absorptivity of the protective film-forming film and its cured product can be further improved.

[0115] On the other hand, the ratio is preferably 0.1% by mass or less, for example, it can be any range of 0.05% by mass or less, 0.04% by mass or less, and 0.03% by mass or less. By making the ratio below the upper limit, the reflectivity of light (420-700nm) of the protective film-forming film and its cured product can be further improved.

[0116] The carbon material can maintain the reflectivity of light (420-700 nm) at a high level in a trace amount, and can also improve the absorptivity of light (532 nm) and the absorptivity of light (1064 nm). In particular, setting the ratio to 0.1% by mass or less is excellent in that the optical properties of the target protective film are easily achieved. That is, as an example of a preferred protective film-forming film of the present embodiment, a protective film-forming film containing a carbon material and having a content of the carbon material in the protective film-forming film of 0.1% by mass or less relative to the total mass of the protective film-forming film can be cited.

[0117] The ratio of the content of the carbon material shown here is applied to the thermosetting protective film-forming film, the energy ray-curable protective film-forming film, and the non-curable protective film-forming film described later.

[0118] <<Light (420~700nm) transmittance>>

[0119] When the protective film-forming film of the present embodiment is curable, the transmittance of the cured product of the protective film-forming film in the full wavelength range of 420 to 700 nm (i.e., light (420 to 700 nm)) is preferably 40% or less. In other words, the maximum value of the transmittance of the cured product of the protective film-forming film in the light (420 to 700 nm) is preferably 40% or less.

[0120] When the protective film-forming film of the present embodiment is non-curable, the transmittance of light in the full wavelength range of 420 to 700 nm (i.e., light (420 to 700 nm)) of the protective film-forming film is preferably 40% or less. In other words, the maximum value of the transmittance of light (420 to 700 nm) of the protective film-forming film is preferably 40% or less.

[0121] The lower the transmittance is, the less influence the structure in contact with the protective film in the workpiece with the protective film (usually the workpiece) has on the color of the protective film when the workpiece with the protective film is observed with the naked eye from the protective film side, and the protective film can be seen with a color closer to its inherent color.

[0122] In this specification, unless otherwise specified, when the protective film-forming film is curable, the “transmittance of light (420~700nm)” means the “transmittance of light (420~700nm) of the cured product of the protective film-forming film”; and when the protective film-forming film is non-curable, the “transmittance of light (420~700nm)” means the “transmittance of light (420~700nm) of the protective film-forming film”.

[0123] In order to enhance the above-mentioned effects, the transmittance of light (420 to 700 nm) may be, for example, 34% or less, 29% or less, 24% or less, or 19% or less, regardless of whether the protective film-forming film is curable or not.

[0124] 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 2% or more can be more easily achieved.

[0125] In one embodiment, the transmittance of light (420-700 nm) can be, for example, any range of 2-40%, 2-34%, 2-29%, 2-24% and 2-19%. These ranges are only examples of the transmittance of light (420-700 nm).

[0126] The transmittance of light in the full wavelength range of 420 to 700 nm of the curable protective film-forming film in the uncured state (i.e., of the protective film-forming film itself) is preferably within the same range (e.g., less than 40%) as the transmittance of light (420 to 700 nm) of the cured product of the above-mentioned protective film-forming film.

[0127] In the protective film-forming film and its cured product, the transmittance of light (420-700 nm) can be adjusted, for example, by adjusting the type and content of the components contained in the protective film-forming film. In particular, by making the protective film-forming film a protective film-forming film containing a colorant (colorant (J) in a thermosetting protective film-forming film, a colorant in an energy-ray-curable protective film-forming film and a non-curable protective film-forming film) described later, the transmittance of light (420-700 nm) of the protective film-forming film and its cured product can be more easily adjusted by adjusting the type and content of the colorant in the protective film-forming film.

[0128] <<Color tones of both surfaces of the protective film forming film>>

[0129] The protective film forming film of this embodiment preferably has a single color tone on at least two surfaces, or the protective film forming film may have a single color tone as a whole. Such a protective film forming film is advantageous in that the printed characters can be clearly confirmed with the naked eye in the state where the printed characters are finally applied to the protective film. In addition, such a protective film forming film is also advantageous in that it is easy to manufacture and that the color tone of the workpiece with the protective film formed from one workpiece with the protective film forming film is uniform.

[0130] Both surfaces of the protective film-forming film are the same as, for example, a first surface and a second surface described later.

[0131] In this specification, the color tone of both surfaces of the protective film-forming film is single means that both surfaces of the protective film-forming film have a single color tone (same color) throughout the entire region.

[0132] In the present specification, the first and second surfaces of the protective film forming film have a single color tone, which means that, for the first surface of the protective film forming film, the light reflectance of each 1 nm wavelength is measured in the full wavelength range of 420~700nm, the light reflectance at a wavelength of xnm (x is any integer between 420~700) is set as light reflectance R1(x), and the light reflectance of the second surface of the protective film forming film measured in the same manner is set as light reflectance R2(x), and when the difference in light reflectance of each wavelength is calculated by formula R1(x)-R2(x), the maximum value of the absolute values ​​of all the differences in light reflectance is less than 1.5%.

[0133] In the present specification, the entire protective film-forming film having a single color tone means that not only the entire regions of both surfaces of the protective film-forming film have a single color tone, but also the entire region inside the protective film-forming film has a single color tone (same color).

[0134] The color tone of the protective film-forming film can be adjusted by adjusting the types and contents of the components contained in the protective film-forming film, for example. In particular, the color tone of the protective film-forming film can be adjusted more easily by adjusting the type and content of the colorant contained in the protective film-forming film.

[0135] When the protective film-forming film is thermosetting, the cured product of the protective film-forming film that specifies the reflectivity of the light (420~700nm), the absorptivity of the light (532nm), the absorptivity of the light (1064nm) and the transmittance of the light (420~700nm) refers to a thermosetting product, which is the protective film and is a cured product obtained by heating the protective film-forming film at 140°C for 2 hours.

[0136] When the protective film-forming film is energy-ray curable, the protective film-forming film having the reflectivity of the light (420-700 nm), the absorptivity of the light (532 nm), the absorptivity of the light (1064 nm) and the transmittance of the light (420-700 nm) is defined as a cured product of the protective film-forming film, which is the protective film and is cured under an illumination of 220 mW / cm 2 、The amount of energy ray is 600mJ / cm 2 A cured product obtained by irradiating the protective film-forming film with energy rays under conditions of.

[0137] 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, the multiple layers may be the same or different from each other, and the combination of the multiple layers is not particularly limited.

[0138] In this specification, not limited to the case of a protective film forming film, "multiple layers may be the same as or different from each other" means "all the layers may be the same, all the layers may be different, or only some of the layers may be the same", and further, "multiple layers may be different from each other" means "at least one of the constituent materials and thicknesses of each layer is different from each other".

[0139] The thickness of the protective film forming film is preferably less than 50 μm, more preferably less than 45 μm. By making the thickness of the protective film forming film less than the upper limit, the thickness of the workpiece with the protective film can be thinned, and various devices such as light-emitting devices having the workpiece with the protective film can be thinned.

[0140] The lower limit of the thickness of the protective film forming film is not particularly limited. For example, in order to further enhance the protective effect of the protective film, the thickness of the protective film forming film is preferably 10 μm or more.

[0141] Here, the “thickness of the protective film forming film” refers to the thickness of the protective film forming film as a whole. For example, the thickness of a protective film forming film composed of multiple layers refers to the total thickness of all layers constituting the protective film forming film. This also applies to other layers such as the substrate and adhesive layer described later.

[0142] In this specification, unless otherwise specified, “thickness” refers to a value represented by the average thickness measured at five randomly selected locations on an object, not limited to the case of a protective film-forming film, and can be obtained using a constant pressure thickness gauge in accordance with JIS K7130.

[0143] <<Protective film forming composition>>

[0144] The protective film-forming film can be formed using a protective film-forming composition containing the constituent materials of the protective film-forming film. For example, the protective film-forming film can be formed by applying the protective film-forming composition on the surface of the object to be formed and drying it as needed. 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, "normal temperature" refers to a temperature that is not particularly cooled or heated, that is, a normal temperature, for example, a temperature of 18 to 28°C, etc.

[0145] In the protective film-forming film, the total content of one or two or more components described below in the protective film-forming film is 100% by mass or less relative to the total mass of the protective film-forming film.

[0146] Similarly, in the protective film forming composition, the total content of one or two or more components described below in the protective film forming composition is 100 mass % or less relative to the total mass of the protective film forming composition.

[0147] The protective film-forming composition can be applied by a known method such as a method using various coaters.

[0148] The drying conditions are not particularly limited as long as the protective film-forming composition itself and the thermosetting protective film-forming film formed from the composition are not thermally cured. When the protective film-forming composition contains a solvent as described below, it is preferably dried by heating, more preferably at 70 to 130° C. for 10 seconds to 5 minutes.

[0149] Hereinafter, 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 in order.

[0150] <Thermosetting protective film-forming film, thermosetting protective film-forming composition (III)>

[0151] The curing conditions when the thermosetting protective film-forming film is thermally cured to form the protective film are not particularly limited as long as the protective film is cured to a degree that allows the protective film to fully exhibit its function.

[0152] For example, the heating temperature during the thermal curing of the thermosetting protective film-forming film is preferably 100 to 200° C., for example, it can be any range of 110 to 170° C. and 120 to 150° C. The heating time during the thermal curing is preferably 0.5 to 5 hours, for example, it can be any range of 0.5 to 4 hours and 1 to 3 hours.

[0153] Preferred examples of thermosetting protective film-forming films include films 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 simply referred to as "composition (III)" in this specification) containing the polymer component (A), the thermosetting component (B), the thermosetting agent (C), the filler (E), and the colorant (J).

[0154] 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 be only one kind or two or more kinds respectively. When there are two or more kinds, their combination and proportion may be selected arbitrarily.

[0155] [Polymer component (A)]

[0156] The polymer component (A) is a component formed by polymerization of a polymerizable compound and is used to impart film-forming properties, flexibility, toughness, ductility, etc. to the thermosetting protective film-forming film and to impart flexibility, toughness, ductility, etc. to the protective film.

[0157] In this specification, the polymerization reaction also includes a polycondensation reaction.

[0158] Examples of the polymer component (A) include acrylic resins, urethane resins, phenoxy resins, silicone resins, and saturated polyester resins, and acrylic resins are preferred.

[0159] Examples of the acrylic resin in the polymer component (A) include known acrylic polymers.

[0160] The weight average molecular weight (Mw) of the acrylic resin is preferably 10000 to 2000000, for example, it can be any range of 100000 to 1500000, 150000 to 1200000 and 200000 to 1000000. By making the weight average molecular weight of the acrylic resin above the lower limit, the shape stability (time stability during storage) of the protective film-forming film is improved. By making the weight average molecular weight of the acrylic resin below the upper limit, the protective film-forming film easily follows the concavo-convex surface of the adherend.

[0161] In this specification, unless otherwise specified, the "weight average molecular weight" means a polystyrene-equivalent value measured by gel permeation chromatography (GPC).

[0162] The glass transition temperature (Tg) of the acrylic resin is preferably 0 to 70°C, for example, any range of 0 to 50°C, 0 to 30°C, and 0 to 10°C. By making the Tg of the acrylic resin above the lower limit, the adhesion between the protective film and the support sheet described below can be suppressed, and the peelability of the support sheet can be appropriately improved. By making the Tg of the acrylic resin below the upper limit, the protective film-forming film can easily follow the concave and convex surface of the adherend.

[0163] When the acrylic resin has two or more structural units, the glass transition temperature (Tg) of the acrylic resin can be calculated using the Fox equation. As the Tg of the homopolymer of the monomer derived from the structural unit used at this time, the value described in the Polymer Data Handbook, the Adhesion Handbook, or the Polymer Handbook can be used.

[0164] Examples of acrylic resins include polymers of one or more (meth)acrylates; copolymers of two or more monomers selected from the group consisting of (meth)acrylates, (meth)acrylic acid, itaconic acid, vinyl acetate, acrylonitrile, styrene, and N-hydroxymethyl acrylamide; and the like.

[0165] Examples of the (meth)acrylate constituting the acrylic resin include methyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, sec-butyl (meth)acrylate, tert-butyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate, and alkyl (meth)acrylates in which the alkyl group constituting the alkyl ester is a chain structure having 1 to 18 carbon atoms;

[0166] Cycloalkyl (meth)acrylates such as dicyclopentyl (meth)acrylate;

[0167] Glycidyl (meth)acrylates such as glycidyl (meth)acrylate;

[0168] (Meth)acrylates containing a hydroxyl group such as 2-hydroxyethyl (meth)acrylate, and the like.

[0169] In this specification, "(meth)acrylic acid" is a concept including both "acrylic acid" and "methacrylic acid." The same applies to terms similar to (meth)acrylic acid.

[0170] The monomers constituting the acrylic resin may be one kind or two or more kinds. When two or more kinds are used, the combination and ratio of the monomers may be arbitrarily selected.

[0171] 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 carboxyl group, an isocyanate group, etc. The functional group of the acrylic resin may bond to other compounds via a crosslinking agent (G) described later, or may bond directly to other compounds without the crosslinking agent (G).

[0172] As the polymer component (A), thermoplastic resins other than acrylic resins such as polyester, polyurethane, phenoxy resin, polybutene, polybutadiene, and polystyrene can be used.

[0173] In the composition (III), regardless of the type of the polymer component (A), the content of the polymer component (A) relative to the total content of all components excluding the solvent is preferably 10 to 85% by mass, for example, it can be any range of 10 to 55% by mass and 10 to 25% by mass.

[0174] This content is synonymous with the following content: In the thermosetting protective film-forming film, regardless of the type of polymer component (A), the content of the polymer component (A) relative to the total mass of the thermosetting protective film-forming film is preferably 10 to 85 mass %, for example, it can be any range of 10 to 55 mass % and 10 to 25 mass %.

[0175] This is because in the process of removing the solvent from the resin composition containing the solvent to form a resin film, the amount of components other than the solvent usually does not change, and the ratio of the content of the components other than the solvent between the resin composition and the resin film is the same. Therefore, in this specification, not limited to the case of forming a protective film, the content of the components other than the solvent is only recorded as the content in the resin film after removing the solvent from the resin composition.

[0176] [Thermosetting component (B)]

[0177] The thermosetting component (B) is a component having thermosetting properties for curing the thermosetting protective film-forming film.

[0178] Examples of the thermosetting component (B) include epoxy-based thermosetting resins, thermosetting polyimide resins, and unsaturated polyester resins, and epoxy-based thermosetting resins are preferred.

[0179] In this specification, the thermosetting polyimide resin is a general term for a polyimide precursor and a thermosetting polyimide which form a polyimide resin by thermal curing.

[0180] Examples of the epoxy resin include known epoxy resins, such as epoxy compounds having a functionality of two or more, such as polyfunctional epoxy resins, biphenyl compounds, bisphenol A diglycidyl ether and its hydride, o-cresol novolac epoxy resin, dicyclopentadiene epoxy resin, biphenyl epoxy resin, bisphenol A epoxy resin, bisphenol F epoxy resin, and phenylene skeleton epoxy resin.

[0181] The epoxy resin may have an unsaturated hydrocarbon group.

[0182] The number average molecular weight of the epoxy resin is not particularly limited, but is preferably 300 to 30,000 from the viewpoint of the curability of the thermosetting protective film-forming film and the strength and heat resistance of the protective film as its cured product.

[0183] The epoxy equivalent of the epoxy resin is preferably 100 to 1000 g / eq, and may be, for example, in the range of 150 to 600 g / eq or 150 to 400 g / eq.

[0184] [Thermosetting agent (C)]

[0185] 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).

[0186] Examples of the thermosetting agent (C) include compounds having two or more functional groups reactive with epoxy groups in one molecule, such as phenolic hydroxyl groups, alcoholic hydroxyl groups, amino groups, carboxyl groups, and groups obtained by acid anhydriding acid groups.

[0187] Among the thermosetting agents (C), examples of the phenolic curing agents having a phenolic hydroxyl group include polyfunctional phenol resins, biphenol, novolac-type phenol resins, dicyclopentadiene-type phenol resins, and aralkyl-type phenol resins.

[0188] Among the thermosetting agents (C), examples of the amine-based curing agents having an amino group include dicyandiamide and the like.

[0189] In the thermosetting agent (C), the number average molecular weight of the resin component such as multifunctional phenolic resin, novolac phenolic resin, dicyclopentadiene phenolic resin, aralkyl phenolic resin is preferably 300-30000, for example, any range of 400-10000 and 500-3000.

[0190] In the thermosetting agent (C), the molecular weight of non-resin components such as biphenol and dicyandiamide is not particularly limited, but is preferably 60 to 500, for example.

[0191] 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), for example, it can be any range 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. By making the content of the thermosetting agent (C) above the lower limit, it is easier to cure the thermosetting protective film-forming film. By making the content of the thermosetting agent (C) below the upper limit, the moisture absorption rate of the thermosetting protective film-forming film is reduced, and the adhesion reliability of the protective film to the adherend is further improved.

[0192] In the thermosetting protective film forming film, the total content of the thermosetting component (B) and the thermosetting agent (C) is preferably 5 to 40% by mass relative to the total mass of the thermosetting protective film forming film, for example, it can be any range of 5 to 30% by mass and 5 to 20% by mass, it can also be any range of 10 to 40% by mass and 13 to 40% by mass, and it can also be 10 to 30% by mass. By making the ratio in the range as described above, the protective effect of the protective film and the adhesive reliability of the protective film to the adherend are further improved. In addition, the adhesion between the protective film and the support sheet described later is appropriately suppressed, and the peelability of the support sheet is improved.

[0193] [Filling material (E)]

[0194] By making the thermosetting protective film-forming film contain a filler (E), it is easy to adjust the thermal expansion coefficient of the thermosetting protective film-forming film and its cured product (protective film), and by optimizing the thermal expansion coefficient with respect to the object on which the protective film is formed, the adhesion reliability of the protective film to the adherend is further improved. In addition, by making the thermosetting protective film-forming film contain a filler (E), the moisture absorption rate of the protective film can be reduced and the heat dissipation can be improved.

[0195] The filler (E) may be any of an organic filler and an inorganic filler, but is preferably an inorganic filler.

[0196] Preferred inorganic fillers include, for example, powders of silica, alumina, talc, red iron oxide, silicon carbide, boron nitride, etc.; beads obtained by sphericalizing these inorganic fillers; surface-modified products of these inorganic fillers; single crystal fibers of these inorganic fillers; glass fibers, etc.

[0197] In addition, when there is a surface-modified inorganic filler, in this specification, unless otherwise specified, the term "inorganic filler" is a concept including "an inorganic filler that is not a surface-modified inorganic filler" and "a surface-modified inorganic filler". For example, "silicon dioxide" means "either or both of silicon dioxide that is not a surface-modified silicon dioxide and a surface-modified silicon dioxide", unless otherwise specified.

[0198] Among these components, the inorganic filler is preferably silica or alumina, and more preferably silica.

[0199] In the composition (III), from the viewpoint of improving the dispersibility of the filler (E) relative to the other components, the filler (E) is preferably silica, more preferably a surface-modified silica, further preferably silica surface-modified with an organic group (organic compound), further preferably silica surface-modified with a vinyl group, an epoxy group, a phenyl group or a methacrylic group, and particularly preferably silica surface-modified with a vinyl group or an epoxy group.

[0200] 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, from the viewpoint of improving the dispersibility of the filler (E) in other components.

[0201] Unless otherwise specified, the term “average particle size” in this specification refers to a particle size (D50) at which the cumulative value is 50% in a particle size distribution curve determined by a laser diffraction scattering method.

[0202] In the thermosetting protective film-forming film, the content of the filler (E) relative to the total mass of the thermosetting protective film-forming film is preferably 65% ​​by mass or less, for example, it can be any range of 55% by mass or less, 45% by mass or less, 35% by mass or less, 25% by mass or less, and 20% by mass or less. By making the ratio below the upper limit, in addition to being able to adjust the thermal expansion coefficient, moisture absorption rate, heat release, etc. of the protective film, the effect of suppressing accidental peeling of the protective film and the workpiece is also improved.

[0203] On the other hand, the lower limit of the ratio is not particularly limited. For example, by setting the ratio to 5% by mass or more, the effect obtained by using the filler (E) is further enhanced.

[0204] [Colorant (J)]

[0205] The colorant (J) is a component for adjusting the light reflectance and light absorptivity of the thermosetting protective film-forming film and the protective film.

[0206] Examples of the colorant (J) include known colorants such as inorganic pigments, organic pigments, and organic dyes.

[0207] Examples of the colorant (J) include white pigments, components that exhibit a light absorbing effect (particularly referred to as "light absorbers" in this specification), and other colorants that do not belong to either of these two.

[0208] From the viewpoint of further improving the reflectivity of light (420 to 700 nm) of the thermosetting protective film-forming film and its cured product, the thermosetting protective film-forming film preferably contains a white pigment.

[0209] 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, halloysite, and the like.

[0210] The white pigment may be a substance (surface treated product) obtained by surface treating the surface of the above-mentioned substances with a surface treating agent such as an inorganic compound having a hydroxyl group or an organic compound having a hydroxyl group or a carboxyl group. In composition (III), the white pigment as these surface treated products has high dispersibility to components other than the white pigment, and at this time, the characteristics of composition (III) are better.

[0211] Among the above, the white pigment is preferably titanium oxide or a surface-treated product thereof.

[0212] When the thermosetting protective film-forming film contains a white pigment, in the composition (III), the average particle size of the white pigment is preferably 0.05 to 2 μm, more preferably 0.1 to 1 μm, and further preferably 0.2 to 0.7 μm, from the viewpoint of improving the dispersibility of the white pigment to other components and being able to effectively improve the reflectivity of light (420 to 700 nm).

[0213] In the surface-treated white pigment, the portion derived from the surface treatment agent is also regarded as a part of the particle, the particle size of the white pigment including the portion derived from the surface treatment agent is identified, and the average particle size of the white pigment is calculated based on the particle size.

[0214] When the thermosetting protective film-forming film contains a white pigment as a 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. And the effect in this case is also as described above.

[0215] When the composition (III) and the protective film-forming film contain at least a white pigment as a colorant (J), in the composition (III) and the protective film-forming film, 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 the colorant other than the white pigment) is preferably 90 to 99.9% by mass, more preferably 93 to 99.9% by mass, for example, any range of 95 to 99.9% by mass and 97 to 99.9% by mass. By making the ratio above the lower limit, the effect of using the white pigment is further improved. By making the ratio below the upper limit, the effect of using a colorant other than the white pigment (for example, the light absorber or the other colorant) is further improved.

[0216] The thermosetting protective film-forming film preferably contains the light absorber from the viewpoint of further improving the light (532 nm) absorptivity and the light (1064 nm) absorptivity of the thermosetting protective film-forming film and its cured product.

[0217] Examples of the light absorber include carbon materials such as carbon black; black pigments other than carbon black; xanthene-based pigments (pigments having a xanthene ring); and metal oxides.

[0218] Commercially available light absorbers that are useful for increasing the absorptivity of light (532 nm) include, for example, organic black pigments ("6377 black" manufactured by Dainichiseika Color & Chemicals Mfg. Co., Ltd.), xanthene pigments ("polymeric dye fluorescent violet R13" manufactured by FUJIFILM Wako Pure Chemical Corporation), etc., which are described later in the examples.

[0219] Examples of commercially available light absorbers useful for increasing the absorptivity of light (1064 nm) include antimony-doped tin oxide ("Iriotec (registered trademark) 8817" manufactured by Merck Performance Materials Ltd.) described later in Examples.

[0220] Examples of the light absorber that is useful for increasing both the absorptivity of light (532 nm) and the absorptivity of light (1064 nm) include carbon black.

[0221] When the thermosetting protective film-forming film contains a light absorber as a colorant (J), the ratio of the content of the light absorber 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 light absorber in the protective film-forming film to the total mass of the protective film-forming film described above. And the effect in this case is also as described above.

[0222] In addition to the polymer component (A), the thermosetting component (B), the thermosetting agent (C), the filler (E) and the colorant (J), the composition (III) and the thermosetting protective film-forming film may or may not contain other components that are not included in the above components.

[0223] 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).

[0224] The curing accelerator (D), coupling agent (F), crosslinking agent (G), energy ray curing component (H), photopolymerization initiator (I) and general additive (K) contained in the composition (III) and the thermosetting protective film forming film can be only one kind or two or more kinds. When there are two or more kinds, their combination and proportion can be selected arbitrarily.

[0225] [Curing accelerator (D)]

[0226] The curing accelerator (D) is a component for adjusting the curing speed of the thermosetting protective film-forming film.

[0227] Preferred curing accelerators (D) include, for example, imidazoles (imidazoles in which one or more hydrogen atoms are substituted by groups other than hydrogen atoms) such as 2-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, and 2-phenyl-4-methyl-5-hydroxymethylimidazole, tertiary amines, organic phosphines (phosphines in which one or more hydrogen atoms are substituted by organic groups), tetraphenylborate, and the like.

[0228] When using a curing accelerator (D), in a thermosetting protective film-forming film, relative to 100 parts by mass of the total content of the thermosetting component (B) and the thermosetting agent (C), the content of the curing accelerator (D) is preferably 0.01 to 10 parts by mass, for example, it can be any range of 0.1 to 7 parts by mass and 0.5 to 5 parts by mass. By making the content of the curing accelerator (D) above the lower limit, the effect brought by the use of the curing accelerator (D) can be obtained more significantly. By making the content of the curing accelerator (D) below the upper limit, for example, the effect of suppressing the high-polarity curing accelerator (D) to move to the bonding interface side with the adherend and segregate in the thermosetting protective film-forming film under high temperature and high humidity conditions is increased. As a result, the bonding reliability of the protective film to the adherend is further improved.

[0229] [Coupling agent (F)]

[0230] By using a coupling agent (F) having a functional group reactive with an inorganic compound or an organic compound, the reliability of adhesion of the protective film to the adherend can be improved.

[0231] The coupling agent (F) is preferably a compound having a functional group reactive with a functional group possessed by the polymer component (A), the thermosetting component (B), etc., and is more preferably a silane coupling agent.

[0232] Preferred examples of the silane coupling agent include 3-glycidyloxypropyltrimethoxysilane, 3-glycidyloxypropylmethyldiethoxysilane, 3-glycidyloxypropyltriethoxysilane, and 3-glycidyloxymethyldiethoxysilane.

[0233] As a preferred silane coupling agent, for example, an oligomer silane coupling agent having a plurality of alkoxysilyl groups in one molecule can be cited. The oligomer silane coupling agent is not easily volatile and has a plurality of alkoxysilyl groups in one molecule, so it is preferred because it is effective in improving the durability of the protective film.

[0234] As the oligomer silane coupling agent, for example, "X-41-1053", "X-41-1059A", "X-41-1056" and "X-40-2651" (all manufactured by Shin-Etsu Chemical Co., Ltd.) as epoxy-containing oligomer silane coupling agents; "X-41-1818", "X-41-1810" and "X-41-1805" (all manufactured by Shin-Etsu Chemical Co., Ltd.) as mercapto-containing oligomer silane coupling agents, etc. can be listed.

[0235] When a coupling agent (F) is used, in the composition (III) and the thermosetting protective film-forming film, the content of the coupling agent (F) is preferably 0.03 to 5 parts by mass, for example, it can be any range of 0.03 to 3 parts by mass and 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). By making the content of the coupling agent (F) above the lower limit, the effects of using the coupling agent (F), such as improving the dispersibility of the filler (E) in the resin and improving the adhesion reliability of the protective film to the adherend, can be more significantly obtained. By making the content of the coupling agent (F) below the upper limit, the generation of degassing can be further suppressed.

[0236] [Crosslinking agent (G)]

[0237] When the polymer component (A) is an acrylic resin or the like as described above and has a functional group such as a vinyl group, a (meth)acryloyl group, an amino group, a hydroxyl group, a carboxyl group, an isocyanate group, etc. that can be bonded to other compounds, the crosslinking agent (G) bonds the functional group in the polymer component (A) to other compounds to perform crosslinking. In this case, the adhesion and cohesion of the protective film-forming film can be adjusted.

[0238] Examples of the crosslinking agent (G) include organic polyisocyanate compounds, organic polyimide compounds, metal chelate crosslinking agents (crosslinking agents having a metal chelate structure), and aziridine crosslinking agents (crosslinking agents having an aziridine group).

[0239] When a crosslinking agent (G) is used, in the composition (III), the content of the crosslinking agent (G) is preferably 0.01 to 20 parts by mass, more preferably 0.1 to 10 parts by mass, and further preferably 0.5 to 5 parts by mass relative to 100 parts by mass of the content of the polymer component (A). By making the content of the crosslinking agent (G) above the lower limit, the effect brought about by the use of the crosslinking agent (G) can be more significantly obtained. By making the content of the crosslinking agent (G) below the upper limit, the excessive use of the crosslinking agent (G) can be suppressed.

[0240] [Energy beam curable component (H)]

[0241] The thermosetting protective film-forming film can change its properties by irradiation with energy rays by containing an energy ray-curable component (H).

[0242] The energy-ray curable component (H) is an energy-ray curable compound or an oligomer or polymer having energy-ray curability which is considered to be synthesized from the energy-ray curable compound.

[0243] 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.

[0244] When an energy-ray curable component (H) is used, in the thermosetting protective film-forming film, the content of the energy-ray curable component (H) is preferably 1 to 20% by mass relative to the total mass of the thermosetting protective film-forming film. By making the ratio within such a range, the effect of using the energy-ray curable component (H) can be well obtained without impairing other properties of the thermosetting protective film-forming film.

[0245] The thermosetting protective film-forming film preferably contains substantially no energy ray (e.g., ultraviolet) curable components. Even if such a thermosetting protective film-forming film is irradiated with energy rays, it is basically not confirmed that the elastic modulus of the thermosetting protective film-forming film increases at room temperature and other physical property changes accompanying curing. In addition, even if such a thermosetting protective film-forming film has the property of reflecting energy rays, it can be cured only by thermal curing without irradiating energy rays, thereby forming a cured product with a sufficient degree of curing.

[0246] In this specification, “the protective film-forming film contains substantially no 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% by mass based on the total mass of the protective film-forming film.

[0247] [Photopolymerization initiator (I)]

[0248] The photopolymerization initiator (I) is a component for efficiently advancing the polymerization reaction of the energy ray-curable component (H).

[0249] The photopolymerization initiator (I) may be a known photopolymerization initiator.

[0250] When the photopolymerization initiator (I) is used, the content of the photopolymerization initiator (I) is preferably 0.1 to 20 parts by mass based on 100 parts by mass of the energy ray-curable component (H) in the composition (III) and the thermosetting protective film-forming film.

[0251] [General additives (K)]

[0252] The general-purpose additive (K) may be a known additive, and can be arbitrarily selected according to the purpose, without particular limitation.

[0253] Preferred general-purpose additives (K) include, for example, plasticizers, antistatic agents, antioxidants, gettering agents, ultraviolet absorbers, and thickeners.

[0254] The content of the composition (III) and the general-purpose additive (K) for forming a thermosetting protective film is not particularly limited and may be appropriately selected depending on the purpose.

[0255] [Solvent]

[0256] The composition (III) preferably further contains a solvent. The composition (III) containing a solvent has good handleability.

[0257] In this specification, unless otherwise specified, the concept of "solvent" includes not only a substance that dissolves the target component but also a dispersion medium that disperses the target component.

[0258] The solvent is not particularly limited, and preferred examples of the solvent 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; amides (compounds having an amide bond) such as dimethylformamide and N-methylpyrrolidone, and the like.

[0259] The solvent contained in the composition (III) may be only one kind or two or more kinds. When there are two or more kinds, the combination and ratio of the solvents can be arbitrarily selected.

[0260] The content of the solvent in the composition (III) is not particularly limited and may be appropriately selected depending on the types of components other than the solvent, for example.

[0261] <Method for preparing thermosetting protective film-forming composition>

[0262] The thermosetting protective film-forming composition such as the composition (III) can be obtained by blending the respective components constituting the thermosetting protective film-forming composition.

[0263] The temperature and time for adding and mixing the components are not particularly limited as long as the components do not deteriorate, and may be appropriately adjusted, but the temperature is preferably 15 to 30°C.

[0264] <Energy ray-curable protective film-forming film, energy ray-curable protective film-forming composition (IV)>

[0265] The curing conditions when the energy-ray-curable protective-film-forming film is energy-ray-cured to form the protective film are not particularly limited as long as the degree of curing is such that the protective film fully exhibits its function.

[0266] For example, the irradiance of the energy ray when the energy ray-curable protective film is cured is preferably 60 to 320 mW / cm 2 Furthermore, the amount of energy ray during curing is preferably 100 to 1000 mJ / cm 2 .

[0267] Preferred energy-ray-curable protective film-forming films include, for example, energy-ray-curable protective film-forming films containing an energy-ray-curable component (a), a filler, and a colorant. Such energy-ray-curable protective film-forming films can be formed using an energy-ray-curable protective film-forming composition (IV) (sometimes simply referred to as "composition (IV)" in this specification) containing the energy-ray-curable component (a), a filler, and a colorant.

[0268] 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.

[0269] 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.

[0270] As the energy-ray-curable component (a), the polymer not having an energy-ray-curable group (b), the filler, the colorant, the coupling agent, the cross-linking agent, the photopolymerization initiator and the general additive, the same substances as the energy-ray-curable component (H), the polymer component not having an energy-ray-curable group (A), the filler (E), the colorant (J), the coupling agent (F), the cross-linking agent (G), the photopolymerization initiator (I) and the general additive (K) contained in the composition (III) and the thermosetting protective film-forming film can be listed respectively.

[0271] The content of each of the above components in the composition (IV) and the energy-ray-curable protective film-forming film may be appropriately adjusted depending on the purpose.

[0272] Since the handling properties of the composition (IV) are improved by dilution, the composition (IV) further preferably contains the same solvent as that of the composition (III).

[0273] The energy-ray-curable protective film-forming composition such as the composition (IV) can be obtained by blending the respective components constituting the composition.

[0274] The energy-ray-curable protective film-forming composition can be prepared by the same method as the thermosetting protective film-forming composition described above, except that the types of the blended components are different, for example.

[0275] <Non-curable protective film-forming film, non-curable protective film-forming composition (V)>

[0276] Preferred non-curable protective film-forming films include, for example, non-curable protective film-forming films 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 simply abbreviated as "composition (V)") containing the polymer component, the filler, and the colorant.

[0277] The composition (V) and the non-curable protective film-forming film may or may not contain other components other than the above components, in addition to the polymer component, the filler and the colorant.

[0278] Examples of the other components include coupling agents, cross-linking agents, and general-purpose additives.

[0279] As the polymer component, filler, colorant, coupling agent, crosslinker and general additive, the same substances as the polymer component (A), filler (E), colorant (J), coupling agent (F), crosslinker (G) and general additive (K) as the components contained in the composition (III) and the thermosetting protective film forming film can be listed respectively.

[0280] The content of each of the above components in the composition (V) and the non-curable protective film-forming film may be appropriately adjusted depending on the purpose.

[0281] Since the handling properties of the composition (V) are improved by dilution, the composition (V) further preferably contains the same solvent as that of the composition (III).

[0282] The non-curable protective film-forming composition such as the composition (V) can be obtained by blending the respective components constituting the composition.

[0283] The non-curable protective film-forming composition can be prepared by the same method as the thermosetting protective film-forming composition described above, except that the types of the blended components are different.

[0284] ◎Example of protective film forming film

[0285] As an example of a preferred protective film-forming film, there can be cited a protective film-forming film for forming a protective film at any position of a workpiece obtained by processing the workpiece.

[0286] 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).

[0287] The thermally cured product of the protective film-forming film has a reflectivity of 22% or more for light in the entire wavelength range of 420 to 700 nm, and an absorptivity of 7% or more for light at either or both wavelengths of 532 nm and 1064 nm.

[0288] Such a protective film-forming film contains a white pigment and a light absorber as the colorant (J), wherein the content of the white pigment in the protective film-forming film is 0.8% by mass or more relative to the total mass of the protective film-forming film, and the content of the light absorber in the protective film-forming film is 0.7% by mass or less relative to the total mass of the protective film-forming film.

[0289] In the protective film-forming film, the content of the filler (E) is preferably less than 65% by mass relative to the total mass of the protective film-forming film (wherein, in the protective film-forming film, the total content 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% by mass).

[0290] Furthermore, in such a protective film-forming film, the content of the polymer component (A) is 10~85% by mass relative to the total mass of the protective film-forming film, the total content of the thermosetting component (B) and the thermosetting agent (C) is 5~40% by mass, and the content of the thermosetting agent (C) is preferably 0.1~100 parts by mass relative to 100 parts by mass of the thermosetting component (B) (wherein, in the protective film-forming film, the total content 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% by mass).

[0291] Furthermore, when such a protective film-forming film contains a carbon material as the light absorber, in the protective film-forming film, the content of the carbon material is preferably 0.1% by mass or less relative to the total mass of the protective film-forming film.

[0292] Figure 1The figure is a cross-sectional view schematically showing an example of a protective film forming film according to an embodiment of the present invention. In addition, in order to facilitate the understanding of the features of the present invention, for convenience, the figures used in the following description sometimes show the main parts in an enlarged manner, and the size ratios of the various components are not necessarily the same as the actual ones.

[0293] The protective film forming film 13 shown here has a first release film 151 on one surface (sometimes referred to as the "first surface" in this specification) 13a thereof, and has a second release film 152 on the other surface (sometimes referred to as the "second surface" in this specification) 13b on the opposite side of the first surface 13a. By providing the protective film forming film 13 with the first release film 151 and the second release film 152, it is possible to suppress the adhesion of foreign matter to the first surface 13a and the second surface 13b of the protective film forming film 13. The release film is an arbitrary structure, and the protective film forming film 13 may not have any of the first release film 151 and the second release film 152.

[0294] Such a protective film-forming film 13 is preferably stored in a roll form, for example.

[0295] When the protective film forming film 13 is curable, the reflectivity of the cured product of the protective film forming film 13 in the entire wavelength range of 420 to 700 nm is 22% or more, and the absorptivity of the cured product in either or both wavelengths of 532 nm and 1064 nm is 7% or more.

[0296] When the protective film forming film 13 is non-curable, the reflectivity of the protective film forming film 13 for light in the entire wavelength range of 420 to 700 nm is 22% or more, and the absorptivity of the protective film forming film 13 for light at either or both wavelengths of 532 nm and 1064 nm is 7% or more.

[0297] The first release film 151 and the second release film 152 may be a known release film such as a release film in which a silicone release agent layer is formed on one surface of a polyethylene terephthalate film.

[0298] The first release film 151 and the second release film 152 may be the same as or different from each other.

[0299] One of the first surface 13 a and the second surface 13 b of the protective film forming film 13 is a bonding surface to be bonded to any position of the workpiece, and the other is a bonding surface of a support sheet or a processing sheet described later.

[0300] The protective film forming film of this embodiment can be attached to any position of the workpiece without being used together with the support sheet described later. On the other hand, it can also be used together with the support sheet described later to form a composite sheet for forming a protective film for simultaneously forming a protective film and processing a workpiece. Such a composite sheet for forming a protective film is described below.

[0301] ◇Composite sheet for protective film formation

[0302] The protective film-forming composite sheet includes a support sheet and a protective film-forming film provided on one surface 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.

[0303] The protective film-forming composite sheet may be the same as a conventional protective film-forming composite sheet except that it includes the protective film-forming film of the present embodiment.

[0304] In this specification, even after the protective film-forming film is cured, as long as the laminated structure of the support sheet and the cured product of the protective film-forming film is maintained, the laminated structure is referred to as a "protective film-forming composite sheet".

[0305] ◎Support sheet

[0306] Examples of the support sheet include a support sheet having a substrate and an adhesive layer provided on one surface of the substrate, a support sheet consisting only of a substrate, and other known support sheets. When the support sheet has an adhesive layer, in the composite sheet for forming a protective film, the adhesive layer is disposed between the substrate and the protective film-forming film.

[0307] The support sheet preferably has light transmittance. For example, when the support sheet has light (532nm) or light (1064nm) transmittance, when printing on the protective film forming film or its cured product, the protective film forming film or its cured product is irradiated with laser (532nm) or laser (1064nm) via the support sheet (through the support sheet), thereby enabling printing, and the usefulness of the composite sheet for protective film formation is high.

[0308] 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.

[0309] ◎Other components

[0310] The composite sheet for forming a protective film of this embodiment may further include or not include any one or both of a clamp adhesive layer and a release film on the surface of the protective film forming film on the side opposite to the support sheet side. The clamp adhesive layer and the release film may be known adhesive layers and release films, and in the composite sheet for forming a protective film of this embodiment, they may be any configuration.

[0311] The jig adhesive layer is provided, for example, in a region near the peripheral portion of the surface of the protective film-forming film on the side opposite to the support sheet side.

[0312] The release film is provided on the surface of the protective film forming film opposite to the support sheet side. When the protective film forming composite sheet includes a jig adhesive layer, the release film may also be provided on the surface of the jig adhesive layer opposite to the protective film forming film side.

[0313] ○Base material

[0314] The substrate is in a sheet or film shape, and examples of its constituent material include various resins.

[0315] The resin constituting the substrate may be one type or two or more types. When there are two or more types, the combination and ratio of the resins may be arbitrarily selected.

[0316] Examples of the resin include polyolefins such as polyethylene and polypropylene; ethylene-vinyl acetate copolymers, ethylene-(meth)acrylic acid copolymers, ethylene-(meth)acrylate copolymers and other ethylene-type copolymers (copolymers obtained using ethylene as a monomer); polystyrene; polycycloolefins; polyesters such as polyethylene terephthalate, and the like.

[0317] The resin may be any of a polymer alloy such as a mixture of two or more resins, a crosslinked resin obtained by crosslinking one or more resins, and a modified resin such as an ionomer using one or more resins.

[0318] In addition to the above-mentioned main constituent materials such as the resin, the base material may contain various known additives such as a filler, a colorant, an antioxidant, an organic lubricant, a catalyst, and a softener (plasticizer).

[0319] The thickness of the substrate is preferably 50 to 300 μm, more preferably 50 to 120 μm. When the thickness of the substrate is within such a range, the flexibility of the composite sheet for forming a protective film and the adaptability to attaching to a workpiece are further improved.

[0320] 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.

[0321] ○Adhesive layer

[0322] The adhesive layer is in a sheet or film shape and contains an adhesive resin.

[0323] 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.

[0324] The thickness of the adhesive layer is not particularly limited, but is preferably 1 to 100 μm, and more preferably 3 to 20 μm.

[0325] The adhesive layer may be either energy-ray-curable or non-energy-ray-curable.

[0326] The adhesive layer can be formed using an adhesive composition containing an adhesive resin. For example, the adhesive layer can be formed on the target site by applying the adhesive composition on the surface to be formed on the adhesive layer and drying it as needed.

[0327] The adhesive composition can be applied and dried by, for example, the same method as that used in the application and drying of the protective film-forming composition described above.

[0328] The adhesive composition can be obtained by blending the adhesive resin and, if necessary, components other than the adhesive resin, which are components constituting the adhesive composition.

[0329] The adhesive composition can be prepared by the same method as the protective film forming composition described above, except that the types of the blended components are different.

[0330] ◇Method for producing composite sheet for forming protective film

[0331] The composite sheet for forming a protective film can be manufactured by laminating the layers in a positional relationship corresponding to the above-mentioned layers and adjusting the shapes of some or all of the layers as necessary. The formation method of each layer is as described above.

[0332] When manufacturing the support sheet, the adhesive composition can be applied on a release film, dried as needed, to form an adhesive layer on the release film, and the adhesive layer can be laminated on the substrate by laminating the exposed surface of the adhesive layer to one surface of the substrate.

[0333] When laminating a protective film forming film on a substrate, for example, a protective film forming composition may be applied to a release film and dried as needed to form a protective film forming film on the release film in advance, and the exposed surface of the protective film forming film may be bonded to one surface of the substrate.

[0334] When a protective film-forming film is further laminated on the adhesive layer laminated on the substrate, for example, a protective film-forming film may be formed on a release film in advance using a protective film-forming composition, and the exposed surface of the formed protective film-forming film may be bonded to the exposed surface of the adhesive layer.

[0335] ◇Method for manufacturing a workpiece with a protective film (method for using a protective film forming film)

[0336] A method for manufacturing a workpiece with a protective film according to an embodiment of the present invention is a method for manufacturing a workpiece with a protective film using the protective film-forming film according to an embodiment of the present invention, wherein when the protective film-forming film is curable, the cured product of the protective film-forming film is the protective film, and when the protective film-forming film is non-curable, the protective film-forming film attached to the workpiece is the protective film. In the manufacturing method, the protective film-forming film is attached to the workpiece, and the protective film-forming film or the protective film attached to the workpiece is printed, and the workpiece is processed to produce the workpiece, and the protective film-forming film or the protective film attached to the workpiece is cut off. When the protective film-forming film is curable, the protective film-forming film attached to the workpiece is further cured to form the protective film. In the above manner, the target workpiece with a protective film can be obtained.

[0337] According to the manufacturing method of this embodiment, by using the protective film forming film, a workpiece with a protective film that is not conspicuous on a white substrate in a light-emitting device can be obtained. The design of the device having such a workpiece with a protective film is high. In addition, the protective film formed by the protective film forming film makes the workpiece with the protective film not conspicuous on the white substrate, so even if it is a protective film with high light reflectivity, dark printing can be sufficiently applied to the protective film.

[0338] In the manufacturing method of this embodiment, after the protective film forming film is attached to the workpiece, the order of performing the steps of printing on the protective film forming film or the protective film, processing the workpiece, cutting the protective film forming film or the protective film, and curing the curable protective film forming film is not particularly limited.

[0339] In each process after the protective film forming film is attached to the workpiece, which one of the protective film forming film and the protective film is operated is determined by the timing of forming the protective film. When the protective film forming film is non-curable, the one operated after the protective film forming film is attached to the workpiece is the protective film in any process. When the protective film forming film is curable, the one operated before the protective film forming film is cured is the protective film forming film, and the one operated after curing is the protective film.

[0340] As the protective film-forming film, a protective film-forming film that does not constitute the protective film-forming composite sheet may be attached to the workpiece, or the protective film-forming film in the protective film-forming composite sheet may be attached to the workpiece.

[0341] The method for manufacturing a workpiece with a protective film of the present embodiment may be the same as the conventional method for manufacturing a workpiece with a protective film, except that the protective film-forming film or the protective film-forming composite sheet of the present embodiment is used instead of the conventional protective film-forming film or the protective film-forming composite sheet.

[0342] When the workpiece is a semiconductor wafer, the workpiece with a protective film is a semiconductor chip with a protective film having a semiconductor chip and a protective film arranged on the back side thereof. When the protective film forming film is non-curing, the protective film forming film after being attached to the back side of the semiconductor wafer is the protective film.

[0343] In the method for manufacturing the semiconductor chip with a protective film, a protective film-forming film is attached to the back surface of a semiconductor wafer, and as a workpiece process, the semiconductor wafer is divided into semiconductor chips.

[0344] In the manufacturing method, when a protective film forming film that does not constitute a composite sheet for protective film formation is used, a processing sheet such as a cutting sheet is attached to the protective film forming film or the exposed surface of the protective film (the surface opposite to the workpiece side) after being attached to the workpiece, and then the workpiece is processed.

[0345] Printing is performed on the protective film forming film or protective film after being attached to the workpiece, and is performed on the surface of these films on the side opposite to the workpiece side. For the protective film forming film or protective film without a support sheet or a processing sheet, such printing can be performed directly, and for the protective film forming film or protective film with a support sheet or a processing sheet, such printing can be performed via the support sheet or the processing sheet (through the support sheet or the processing sheet).

[0346] Printing is preferably performed using a laser with a wavelength of 532 nm or more in a long wavelength range, more preferably using a laser (532 nm) or a laser (1064 nm). By using the protective film of this embodiment to form a film, although the light reflectivity of the protective film is high, dark printing can be fully applied to the protective film.

[0347] For example, when printing with laser (532nm), the speed of laser printing is preferably 50 to 300 mm / s, and the frequency of the laser is preferably 3 to 40 kHz. The output power of the laser can be selected arbitrarily, but when a green laser marker manufactured by EOtech is used as a laser marker, it is preferably 0.1 to 0.5 W.

[0348] For example, when printing is performed using a laser (1064 nm), the speed of the laser printing is preferably 100 to 700 mm / s, and the frequency of the laser is preferably 3 to 20 kHz. The output power of the laser can be selected arbitrarily, but particularly when a fiber laser marker manufactured by SUNX is used as a laser marker, it is preferably 5 to 20 (device setting value, no unit).

[0349] When using either laser (532 nm) or laser (1064 nm), when using a laser marker different from the above as the laser marker, the output power of the laser can be selected with reference to the above conditions.

[0350] The workpiece after the protective film forming film is attached (the workpiece processed product) can be processed using a known method according to the type of the workpiece. For example, when the workpiece is a semiconductor wafer, a known dicing method can be used as a workpiece processing method.

[0351] The cutting of the protective film forming film or the protective film after being attached to the workpiece can be performed by a known method. For example, the cutting method can be selected by considering the order of processing the workpiece and cutting the protective film forming film or the protective film. For example, when the workpiece is a semiconductor wafer, a known dicing method can be used to continuously divide the semiconductor wafer and cut the protective film forming film or the protective film.

[0352] When the protective film-forming film is curable, curing of the protective film-forming film after being attached to the workpiece (formation of the protective film) can be performed by a known method, and the curing conditions are as described above.

[0353] In the manufacturing method, when a curable protective film forming film is used, for example, after the protective film forming film is attached to the workpiece, the protective film forming film is cured to form a protective film, and the protective film is printed, and the workpiece processing and the protective film after printing can be cut in different orders. However, this is only an example of the manufacturing method, and the order of performing each process can be appropriately adjusted according to the type of workpiece, purpose, method of performing each process, etc.

[0354] In the manufacturing method, other processes that do not belong to the above-mentioned processes (attaching the protective film forming film to the workpiece, printing on the protective film forming film or the protective film, processing of the workpiece, cutting of the protective film forming film or the protective film, and curing of the protective film forming film when the protective film forming film is curable) may or may not be performed within the scope that does not impair the effects of the present invention.

[0355] The types and timings of the other steps can be arbitrarily selected according to the type of workpiece, purpose, method of performing each step, etc., and are not particularly limited.

[0356] The produced workpiece with a protective film can be pulled away from the support sheet or the processing sheet and picked up by a known method.

[0357] The workpiece with the protective film is not conspicuous on the white substrate of the light-emitting device to be mounted in the subsequent process, and the design of the light-emitting device is improved.

[0358] By using the protective film forming film of the present embodiment, even if it is a protective film with high light reflectivity, dark printing can be fully applied to the protective film. More specifically, for example, when the protective film is observed using an optical microscope ("VHX-7000" manufactured by Keyence Corporation) under the conditions of white balance (ホワイトバランス) R=1.77, G=1.00, B=2.31, annular lighting, brightness of 100, magnification of 100 times, and shutter speed of 1 / 120 sec, the printing applied to the protective film can be clearly recognized.

[0359] Example

[0360] The present invention will be described in more detail below by way of specific examples, but the present invention is not limited to the following examples.

[0361] <Raw materials for preparing the protective film forming composition>

[0362] The raw materials used for preparing the protective film-forming composition are shown below.

[0363] [Polymer component (A)]

[0364] (A)-1: an acrylic resin obtained by copolymerizing methyl acrylate (87 parts by mass) and 2-hydroxyethyl acrylate (13 parts by mass) (weight average molecular weight: 450,000, glass transition temperature: 6° C.).

[0365] [Thermosetting component (B)]

[0366] (B)-1: Bisphenol A type epoxy resin ("jER828" manufactured by Mitsubishi Chemical Corporation, epoxy equivalent of 184 to 194 g / eq)

[0367] (B)-2: dicyclopentadiene type epoxy resin ("EPICLON HP-7200" manufactured by DIC Corporation, epoxy equivalent of 254 to 264 g / eq)

[0368] [Thermosetting agent (C)]

[0369] (C)-1: Dicyandiamide ("DICY7" manufactured by Mitsubishi Chemical Corporation)

[0370] [Curing accelerator (D)]

[0371] (D)-1: 2-phenyl-4,5-dihydroxymethylimidazole ("CUREZOL 2PHZ" manufactured by SHIKOKU CHEMICALS CORPORATION)

[0372] [Filling material (E)]

[0373] (E)-1: Silica filler (“SC2050MB” manufactured by ADMATECHS., a silica filler surface-modified with an epoxy compound, average particle size 0.5 μm)

[0374] [Coupling agent (F)]

[0375] (F)-1: an oligomer type silane coupling agent having an epoxy group, a methyl group, and a methoxy group ("X-41-1056" manufactured by Shin-Etsu Chemical Co., Ltd., epoxy equivalent: 280 g / eq)

[0376] [Crosslinking agent (G)]

[0377] (G)-1: Toluene diisocyanate-based trifunctional crosslinking agent ("TAKENATE D-101E" manufactured by Mitsui Chemicals, Inc.)

[0378] [Colorant (J)]

[0379] (J)-1: White pigment (rutile titanium dioxide surface-treated with an inorganic compound having a hydroxyl group, average particle size 0.35 μm)

[0380] (J)-2: Organic black pigment ("6377 black" manufactured by Dainichiseika Color & Chemicals Mfg. Co., Ltd.)

[0381] (J)-3: Carbon material (carbon black, "MA600" manufactured by Mitsubishi Chemical Corporation, average particle size: 20 nm)

[0382] (J)-4: Xanthene pigment ("Polymerized Dye Fluorescent Violet R13" manufactured by FUJIFILM Wako Pure Chemical CORPORATION)

[0383] (J)-5: Pigment for laser marking (antimony-doped tin oxide, "Iriotec (registered trademark) 8817", manufactured by Merck Performance Materials Ltd.)

[0384] [Example 1]

[0385] <<Manufacturing of protective film-forming film>>

[0386] <Preparation of protective film-forming composition (III)>

[0387] The types and contents of the components contained in the protective film-forming film are shown in Table 1. Each component was dissolved or dispersed in methyl ethyl ketone and stirred at 23° C. to obtain a thermosetting protective film-forming composition (III) having a total concentration of 57% by mass of all components except the solvent.

[0388] <Manufacturing of protective film-forming film>

[0389] A release film (second release film, "SP-PET50 2150" manufactured by LINTEC Corporation, thickness 50 μm) having one surface of a polyethylene terephthalate film subjected to a release treatment by silicone treatment was applied with the protective film-forming composition (III) obtained above onto the surface subjected to the release treatment, and dried at 100° C. for 2 minutes to produce a thermosetting protective film-forming film having a thickness of 25 μm.

[0390] Furthermore, a release film (first release film, "SP-PET381130" manufactured by LINTEC Corporation, thickness 38 μm) having a release-treated surface was attached to the exposed surface of the protective film-forming film not having the second release film using a laminating roll.

[0391] In the above manner, a laminated film including a protective film-forming film, a first release film provided on one surface of the protective film-forming film, and a second release film provided on the other surface of the protective film-forming film is obtained.

[0392] <<Evaluation of protective film forming film>>

[0393] <Measurement of reflectance of cured product of protective film-forming film (420 to 700 nm)>

[0394] A silicon wafer (350 μm thick) having a ground surface was prepared by grinding one surface of the silicon wafer using a #2000 grinding wheel. The first peeling 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 thus produced was attached to the ground surface of the silicon wafer using a pressure roller heated to 70°C, and the lamination speed was 0.3 m / min.

[0395] Next, the second release film was further removed from the attached protective film-forming film, and the silicon wafer with the protective film-forming film thus obtained was heated at 140° C. for 2 hours to thermally cure the protective film-forming film to form a cured product, thereby obtaining a silicon wafer with a protective film.

[0396] After the obtained silicon wafer with a protective film is naturally cooled to a temperature of 23°C, the amount of total light reflected light combining the specular reflected light (regular reflected light) and the diffuse reflected light is measured for the exposed surface of the solidified material (the surface opposite to the silicon wafer side) at a wavelength range of 380 to 800 nm, every 1 nm, in the SCI method. The amount of total light reflected light is measured on a standard plate made of barium sulfate using the same method as above. In either case, the amount of total light reflected light is measured using a UV-Vis spectrophotometer ("UV-VIS-NIR SPECTROPHOTOMETER UV-3600" manufactured by SHIMADZU CORPORATION). As a sample stage (sample fold), "Large Sample Chamber MPC-3100" manufactured by SHIMADZU CORPORATION was used, and as an integrating sphere, "Integrating Sphere Device ISR-3100" manufactured by SHIMADZU CORPORATION was used, and the incident angle of the incident light to the measured object was set to 8°. In addition, the ratio of the measured value on the solidified product to the measured value on the standard plate ([measured value of the amount of light reflected by the total light on the solidified product of the protective film forming film] / [measured value of the amount of light reflected by the total light on the standard plate]×100) was obtained, that is, the relative total light reflectance of the solidified product of the protective film forming film. The value in the wavelength range of 420~700nm in the obtained relative total light reflectance was used as the reflectance of light (420~700nm).

[0397] <Calculation of the difference between the maximum and minimum reflectance of the cured product of the protective film forming film for light (420 to 700 nm)>

[0398] When measuring the reflectivity of the light (420-700 nm) of the cured product of the protective film-forming film, the maximum and minimum values ​​of the reflectivity of the light (420-700 nm) are read. The value is shown in Table 3 together with the wavelength of the light at this time. Furthermore, the difference between these values ​​(the difference between the maximum value and the minimum value) is calculated. The result is shown in the column "Difference between the maximum value and the minimum value (%)" in Table 3.

[0399] <Measurement of reflectance of light (532 nm) and light (1064 nm) of cured product of protective film-forming film>

[0400] The first release film was removed from the protective film-forming film in the laminated film obtained above. Then, the protective film-forming film was heated at 140° C. for 2 hours to be thermally cured to form a cured product (protective film). The cured product and the second release film were naturally cooled to a temperature of 23° C., and the second release film was removed from the cured product to obtain a single-layer cured product.

[0401] For the surface of the single-layered cured product provided with the second release film, the relative total light reflectance of the cured product of the protective film forming film was determined by the same method as in the above-mentioned "Measurement of the reflectance of the cured product of the protective film forming film at light (420 to 700 nm)", except that the wavelength range for measuring the amount of total light reflected light was set to 380 to 1600 nm instead of 380 to 800 nm. The values ​​of the obtained relative total light reflectance at wavelengths of 532 nm and 1064 nm were respectively used as the reflectance of light (532 nm) and the reflectance of light (1064 nm).

[0402] <Measurement of reflectance of protective film-forming film for light (420 to 700 nm)>

[0403] The reflectivity of the protective film-forming film to light (420 to 700 nm) was measured by the same method as the above-mentioned “reflectivity of the cured product of the protective film-forming film to light (420 to 700 nm)”, except that the reflectivity of the protective film-forming film was directly provided to light (420 to 700 nm) without being thermally cured.

[0404] <Calculation of the difference between the maximum and minimum reflectance of the protective film forming film for light (420 to 700 nm)>

[0405] When measuring the reflectivity of the light (420-700 nm) of the protective film forming film, the maximum and minimum values ​​of the reflectivity of the light (420-700 nm) are read. The value is shown in Table 3 together with the wavelength of the light at this time. Furthermore, the difference between these values ​​(the difference between the maximum value and the minimum value) is calculated. The result is shown in the column "Difference between the maximum value and the minimum value (%)" in Table 3.

[0406] <Measurement of reflectance of light (532 nm) and light (1064 nm) of protective film-forming film>

[0407] The reflectivity of light (532nm) and the reflectivity of light (1064nm) of the protective film-forming film are measured using the same method as the above-mentioned "Measurement of the reflectivity of light (532nm) and the reflectivity of light (1064nm) of the cured product of the protective film-forming film".

[0408] <Measurement of light transmittance (420 to 700 nm) and light transmittance (1064 nm) of cured product of protective film forming film>

[0409] A single-layer cured product was obtained in the same manner as in the above-mentioned “Measurement of reflectance of light (532 nm) and reflectance of light (1064 nm) of cured product of protective film-forming film”.

[0410] For this cured product, a UV-Vis spectrophotometer ("UV-VIS-NIR SPECTROPHOTOMETER UV-3600" manufactured by SHIMADZU CORPORATION) was used, and "ISR-3100 with integrating sphere" manufactured by SHIMADZU CORPORATION was used as an integrating sphere to measure the transmittance of light at every 1 nm in the wavelength range of 380 to 1600 nm. The value in the wavelength range of 420 to 700 nm among the obtained measured values ​​was adopted as the transmittance of light (420 to 700 nm), and the values ​​at wavelengths of 532 nm and 1064 nm were adopted as the transmittance of light (532 nm) and the transmittance of light (1064 nm), respectively. The maximum value of the transmittance of light (420 to 700 nm) is shown in Table 3.

[0411] <Measurement of the transmittance of light (420 to 700 nm) and light (1064 nm) of the protective film formation film>

[0412] The transmittance of light (420-700nm), transmittance of light (532nm) and transmittance of light (1064nm) of the protective film-forming film were measured by the same method as the above-mentioned "Measurement of transmittance of light (420-700nm) and transmittance of light (1064nm) of the cured product of the protective film-forming film", except that the transmittance of light (420-700nm) was directly provided without thermal curing. The maximum value of the transmittance of light (420-700nm) among the obtained measured values ​​is shown in Table 3.

[0413] <Calculation of the light (532 nm) absorptivity and light (1064 nm) absorptivity of the cured product of the protective film forming film>

[0414] Using the values ​​of the reflectivity of light (532nm) and the reflectivity of light (1064nm) of the cured product of the protective film-forming film obtained above, and the transmittance of light (532nm) and the transmittance of light (1064nm) of the cured product of the protective film-forming film, the absorptivity of light (532nm) and the absorptivity of light (1064nm) of the cured product of the protective film-forming film were calculated according to the formula (i). The results are shown in Table 3.

[0415] <Calculation of the light (532 nm) absorptivity and light (1064 nm) absorptivity of the protective film forming film>

[0416] Using the values ​​of the reflectivity of light (532nm) and the reflectivity of light (1064nm) of the protective film-forming film obtained above, and the transmittance of light (532nm) and the transmittance of light (1064nm) of the protective film-forming film, the absorptivity of light (532nm) and the absorptivity of light (1064nm) of the protective film-forming film were calculated according to the formula (i). The results are shown in Table 3.

[0417] <Evaluation of visibility suppression of chip with protective film in light-emitting device>

[0418] A silicon wafer with a protective film was obtained in the same manner as in the above-mentioned “Measurement of reflectance of light (420 to 700 nm) of the cured product of the protective film-forming film”.

[0419] A dicing sheet ("Adwill G-562" manufactured by LINTEC Corporation) was attached to the exposed surface of the protective film in the obtained silicon wafer with the protective film (i.e., the surface opposite to the side provided with the silicon wafer), and the silicon wafer was divided (cut) into 2 mm × 2 mm sizes using a dicing blade to produce silicon chips, and the protective film was also cut into the same size. Thus, a plurality of silicon chips with protective films were produced on the dicing sheet, and the silicon chips with protective films had the silicon chip and the cut protective film provided on the back of the silicon chip.

[0420] Next, the obtained silicon chip with the protective film is pulled away from the dicing sheet and picked up.

[0421] Using the silicon chip with a protective film having a size of 2 mm×2 mm obtained above, a structure for simulation evaluation including a light-emitting device shown below was produced.

[0422] That is, a surface mounted white LED package (size: length 3.2mm×width 2.8mm×height 2mm, luminous intensity: 230mcd (typical)) is set on a white substrate (size: 50mm×50mm). At this time, the light emitting direction of the LED package is the side opposite to the white substrate side. The minimum value of the reflectivity of light in the wavelength range of 420~700nm measured on the white substrate by the same method as the cured product of the protective film forming film is 80%. A silicon chip with a protective film is set at a position 2mm away from one end of the LED package in the width direction, and a silicon chip with a protective film is set at a position 10mm away from the other end of the LED package in the width direction, thereby setting a total of 2 silicon chips with protective films on the white substrate. At this time, the two silicon chips with protective films are set on the white substrate with the silicon chip facing the white substrate side and the protective film facing the side opposite to the white substrate side. A resin white frame (size: 40mm×40mm) with a height of 15mm is set in a total of four directions in the length and width directions of the LED package and 20mm away from the center of the LED package, and a light diffusion plate (size: 45mm×45mm) with a haze of 50% is placed thereon, thereby making a structure for simulation evaluation of the light-emitting device.

[0423] Next, the structure was placed in a dark room, and the LED package was made to emit light under the condition of a current value of 20 mA, and the light-emitting device in this state was observed with the naked eye from a position of 70 cm directly above it. Furthermore, when no two silicon chips with protective films were seen, the light-emitting device in the light-emitting state was further observed with the naked eye from a position of 40 cm directly above it. When at least one silicon chip with a protective film was visible at a position of 70 cm, naked eye observation was not performed from a position of 40 cm. Furthermore, the visual inhibition of the chip with a protective film in the light-emitting device was evaluated according to the following standards. The results are shown in Table 3.

[0424] [Evaluation criteria]

[0425] A: No two silicon chips with protective films were seen at the 70 cm position and the 40 cm position.

[0426] B: Two silicon chips with protective films were not seen at the 70 cm position, but one or two silicon chips with protective films were seen at the 40 cm position.

[0427] C: Only one silicon chip with a protective film was seen at the 70 cm position.

[0428] D: Two silicon chips with protective films are seen at the 70cm position.

[0429] <Evaluation of the visibility of laser (532 nm) printing when printing directly on a protective film under laser printing conditions (1)>

[0430] A silicon wafer with a protective film was obtained in the same manner as in the above-mentioned “Measurement of reflectance of light (420 to 700 nm) of the cured product of the protective film-forming film”.

[0431] After the obtained silicon wafer with protective film is naturally cooled to its temperature of 23°C, a green laser marker ("CSM300M" manufactured by EOtech) is used to laser mark the exposed surface of the protective film (the surface opposite to the silicon wafer side) under the following laser marking conditions (1).

[0432] [Laser printing conditions (1)]

[0433] Laser wavelength: 532nm

[0434] Printed text: ABCDEFGHI

[0435] Printing size: height 200μm x width 200μm

[0436] Printed text line width: 20μm

[0437] Laser printing speed: 100mm / s

[0438] Laser frequency: 20kHz

[0439] Laser output power: 0.3W

[0440] The printed characters on the formed protective film were observed with naked eyes by 5 observers, and the visibility of the formed protective film (the distance from the printed protective film to the observer's eyes) was set to 15 cm. The visibility of the printed characters when the characters were directly printed on the protective film under the laser printing condition (1) was evaluated according to the following criteria. The results are shown in the "Direct Printing" column of "Laser Printing Condition (1): Laser (532 nm) Printing Visibility" in Table 3.

[0441] [Evaluation criteria]

[0442] A: All five observers were able to visually recognize all the printed characters, and the visibility of the printed characters was particularly excellent.

[0443] B: Four out of five observers could visually recognize all the printed characters, and the visibility of the printed characters was good.

[0444] C: The evaluation results do not belong to either A or B, and the visibility of the printed characters is poor.

[0445] <Evaluation of the visibility of laser (532 nm) printing when printing directly on a protective film under laser printing conditions (2)>

[0446] A silicon wafer with a protective film was obtained in the same manner as in the above-mentioned "Measurement of the reflectivity of the cured product of the protective film-forming film at light (420 to 700 nm)". Using the silicon wafer with a protective film, the protective film was directly printed in the same manner as in the above-mentioned laser printing condition (1), except that the laser printing condition (2) shown below was used instead of the above-mentioned laser printing condition (1) to set the laser printing condition.

[0447] [Laser printing conditions (2)]

[0448] Laser wavelength: 532nm

[0449] Printed text: ABCDEFGHI

[0450] Printing size: height 75μm x width 50μm

[0451] Printed text line width: 20μm

[0452] Laser printing speed: 100mm / s

[0453] Laser frequency: 20kHz

[0454] Laser output power: 0.3W

[0455] The printing on the protective film formed above was observed by one observer using an optical microscope ("Digital Microscope VHX-7000" manufactured by Keyence Corporation) under the conditions of white balance of R=1.77, G=1.00, B=2.31, annular lighting, brightness of 100, magnification of 100 times, and shutter speed of 1 / 120 sec. In addition, the visibility of the printing when the printing was directly performed on the protective film under the laser printing condition (2) was evaluated according to the following criteria. The results are shown in the "Direct Printing" column of "Laser Printing Condition (2): Laser (532 nm) Printing Visibility" in Table 3.

[0456] A: The printing is clear and all the printed characters (A~I) are recognizable.

[0457] B: The printing is generally clear, but partially unclear. 7 to 8 of the 9 printed characters (A to I) can be recognized.

[0458] C: The printing is unclear, and more than three of the nine printed characters (A to I) cannot be recognized.

[0459] <Evaluation of the visibility of laser (1064nm) printing when printing directly on a protective film>

[0460] A silicon wafer with a protective film was obtained in the same manner as in the above-mentioned “Measurement of reflectance of light (420 to 700 nm) of the cured product of the protective film-forming film”.

[0461] The obtained silicon wafer with a protective film was naturally cooled to 23° C., and then laser marking was performed on the exposed surface of the protective film (the surface opposite to the silicon wafer side) under the following conditions using a fiber laser marker (“LP-V10” manufactured by SUNX Corporation).

[0462] [Laser printing conditions]

[0463] Laser wavelength: 1064nm

[0464] Printed text: ABCDEFGHI

[0465] Printing character size: Height 200μm × Width 200μm (minimum value that can be set)

[0466] Printed text line width: 10μm

[0467] Laser printing speed: 500mm / s

[0468] Laser power: 15.0 (device setting value, no unit)

[0469] Laser pulse period: 200μs (laser conversion frequency: 5kHz)

[0470] Distance between laser head and sample: 19cm

[0471] The printed characters on the formed protective film were observed with naked eyes by 5 observers, and the visual recognition distance for the printed characters (the distance from the printed protective film to the observer's eyes) was set to 15 cm. The print visibility when the characters were directly printed on the protective film was evaluated according to the following criteria. The results are shown in the "Direct Printing" column of "Laser (1064 nm) Printing Visibility" in Table 3.

[0472] [Evaluation criteria]

[0473] A: All five observers were able to visually recognize all the printed characters, and the visibility of the printed characters was particularly excellent.

[0474] B: Four out of five observers could visually recognize all the printed characters, and the visibility of the printed characters was good.

[0475] C: The evaluation result does not belong to either A or B, and the visibility of the printed characters is poor.

[0476] <<Manufacturing of composite sheet for forming protective film>>

[0477] <Preparation of adhesive composition>

[0478] An acrylic resin (100 parts by mass) as an adhesive resin and a crosslinking agent (xylene diisocyanate adduct of trimethylolpropane, "TAKENATE D110N" manufactured by MITSUI CHEMICALS POLYURETHANES, INC.) (20 parts by mass) are mixed, further diluted with methyl ethyl ketone, and stirred at 23°C to prepare an adhesive composition having a total concentration of 25% by mass of the above-mentioned two components other than methyl ethyl ketone. The blending amounts of the two components other than methyl ethyl ketone shown here are all the blending amounts of the target product without a solvent. The acrylic resin used here is a (meth)acrylate copolymer (weight average molecular weight of 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).

[0479] <Manufacturing of support sheet>

[0480] A third release film ("SP-PET381031" manufactured by LINTEC Corporation, thickness 38 μm) having one surface of a polyethylene terephthalate film subjected to a release treatment by silicone treatment was used, and the above-obtained adhesive composition was applied to the release-treated surface using a doctor blade coater, and heated and dried at 100°C for 2 minutes to form a non-energy ray-curable adhesive layer (thickness 5 μm).

[0481] Next, an uncolored polypropylene film (thickness 80 μm, melting point 156°C, one surface is a frosted surface with a surface roughness (Ra) of 0.20 μm, and the other surface is a slightly frosted surface with a surface roughness (Ra) of 0.15 μm) is used as a substrate, and the exposed surface of the adhesive layer obtained above (the surface opposite to the release film side) is attached to the frosted surface, thereby manufacturing a support sheet with a release film in which the substrate, the adhesive layer and the third release film are stacked in sequence along their thickness direction.

[0482] The third release film was removed from the release-film-attached support sheet obtained above to expose one surface (the surface opposite to the substrate side) of the pressure-sensitive adhesive layer.

[0483] The first release film is removed from the protective film forming film in the laminated film, and the exposed surface (one surface) of the protective film forming film is attached to the adhesive layer in the support sheet using a press roller at room temperature. Thus, a composite sheet for protective film formation is obtained, in which the support sheet, the protective film forming film, and the second release film are sequentially laminated in their thickness direction.

[0484] <<Evaluation of protective film forming film>>

[0485] <Evaluation of the visibility of laser (532 nm) printing when printing on a protective film via a support sheet under laser printing conditions (1)>

[0486] A silicon wafer (350 μm thick) having a ground surface was prepared by grinding one surface of the silicon wafer using a #2000 grinding wheel. The second release film was removed from the protective film forming film in the protective film forming composite sheet obtained above, and the exposed surface of the protective film forming film thus produced was attached to the ground surface of the silicon wafer using a press roll heated to 70° C. and a lamination speed of 0.3 m / min.

[0487] The silicon wafer with the composite sheet for forming a protective film thus obtained was heated at 140° C. for 2 hours to thermally cure the protective film-forming film to form a cured product (forming a protective film), thereby obtaining a silicon wafer with a protective film having a support sheet.

[0488] After the obtained silicon wafer with protective film and the support sheet were naturally cooled to a temperature of 23°C, a green laser marker ("CSM300M" manufactured by EOtech) was used to perform laser (532 nm) printing on the support sheet side of the protective film (the side opposite to the silicon wafer side) under the above-mentioned laser printing conditions (1) through the support sheet. Furthermore, the support sheet was removed from the printed protective film.

[0489] The visibility of the printed characters on the formed protective film was evaluated in the same manner as in the above-mentioned direct printing. The results are shown in the column "Printing through a support sheet" in "Laser printing conditions (1): Laser (532 nm) printing visibility" in Table 3.

[0490] <Evaluation of the visibility of laser (532 nm) printing when printing on a protective film via a support sheet under laser printing conditions (2)>

[0491] A silicon wafer with a protective film having a support sheet is obtained in the same manner as when the evaluation is performed under the laser printing condition (1). The protective film is printed through the support sheet in the same manner as under the laser printing condition (1), except that the silicon wafer with the protective film is used and the laser printing condition is set to the laser printing condition (2) instead of the laser printing condition (1). Furthermore, the support sheet is removed from the printed protective film.

[0492] The visibility of the printed characters on the formed protective film was evaluated in the same manner as the above-mentioned direct printing. The results are shown in the column "Printing through a support sheet" in "Laser printing conditions (2): Laser (532 nm) printing visibility" in Table 3.

[0493] <Evaluation of visibility of laser (1064 nm) printing when printing on a protective film via a support sheet>

[0494] In the same manner as in the evaluation under the laser printing condition (1) described above, a silicon wafer with a protective film and provided with a support sheet was obtained.

[0495] After the silicon wafer with the protective film having the support sheet was naturally cooled to a temperature of 23°C, a fiber laser marker ("LP-V10" manufactured by SUNX) was used to perform laser (1064 nm) printing on the support sheet side of the protective film (the side opposite to the silicon wafer side) through the support sheet using the same printing conditions as when the protective film is directly printed as described above. Further, the support sheet was removed from the printed protective film.

[0496] The visibility of the printed characters on the formed protective film was evaluated in the same manner as in the above-mentioned direct printing. The results are shown in the column "Printing via a support sheet" in "Laser (1064 nm) printing visibility" in Table 3.

[0497] <<Manufacturing of protective film-forming film and composite sheet for protective film-forming, and evaluation of protective film-forming film>>

[0498] [Examples 2 to 8, Comparative Examples 1 to 2]

[0499] A protective film-forming film was produced in the same manner as in Example 1 except that the amounts of the ingredients in the protective film-forming composition (III) or the types and amounts of the ingredients were changed. The types and contents of the ingredients in these protective film-forming films are shown in Tables 1 and 2.

[0500] In addition, the description of “-” in the column of the component contained in the protective film-forming film means that the protective film-forming film does not contain the component.

[0501] Furthermore, a composite sheet for forming a protective film was produced in the same manner as in Example 1 except that these protective film forming films were used.

[0502] Using these protective film-forming films themselves or the protective film-forming composite sheets, the protective film-forming films were evaluated in the same manner as in Example 1. The results are shown in Tables 3 and 4.

[0503] [Table 1]

[0504]

[0505] [Table 2]

[0506]

[0507] [Table 3]

[0508]

[0509] [Table 4]

[0510]

[0511] From the above results, it can be seen that in Examples 1 to 8, the reflectivity of the cured product of the protective film-forming film for light (420 to 700 nm) is 28.5% or more, and the visual suppression of the chip with the protective film in the light-emitting device is good. That is, the protective film-forming films of Examples 1 to 8 can make the workpiece with the protective film inconspicuous on the white substrate.

[0512] Furthermore, in Examples 1 to 8, the light (532 nm) absorptivity of the cured product is 7.2% or more or the light (1064 nm) absorptivity of the cured product is 10.7% or more, and at least one of the laser (532 nm) printing visibility and the laser (1064 nm) printing visibility is good regardless of direct printing or printing through a support sheet. That is, the protective film-forming films of Examples 1 to 8 can sufficiently impart dark printing to the protective film.

[0513] The protective film-forming films of Examples 1 to 8 contain both a white pigment and a light absorber as a colorant (J).

[0514] Among them, in Examples 4 and 6, the light (532nm) absorptivity of the solidified material is greater than 11.4%, and the light (1064nm) absorptivity of the solidified material is greater than 13.1%. Regardless of whether the printing is performed directly or through a support sheet, the laser (532nm) printing visibility and the laser (1064nm) printing visibility are both particularly excellent.

[0515] In particular, the protective film-forming film of Example 4 contained only the carbon material as a light absorber, and the content of the carbon material in the protective film-forming film was 0.025% by mass relative to the total mass of the protective film-forming film.

[0516] In Examples 1 to 8, the difference between the maximum and minimum reflectances of the cured products of the protective film forming films for light (420 to 700 nm) was 15.5% or less, and these protective film forming films were more excellent in making the workpiece with the protective film inconspicuous on the white substrate.

[0517] The protective film-forming films of Examples 1 to 8 contained a white pigment, and in these protective film-forming films, the content of the white pigment was 1% by mass or more relative to the total mass of the protective film-forming films.

[0518] Among them, the visibility suppression of the chip with a protective film in the light-emitting device is particularly excellent in Examples 3, 5 to 8. In Examples 3, 5 to 8, the difference between the maximum and minimum values ​​of the reflectivity of the cured product for light (420 to 700 nm) is 7.3 to 15.5%.

[0519] In Examples 1 to 8, the maximum value of the transmittance of the cured product of the protective film-forming film for light (420 to 700 nm) was 47.6% or less, but in Examples 3 to 8, the maximum value was 31.4% or less. That is, the protective film-forming films of Examples 3 to 8 can form protective films whose colors are not easily affected by the workpiece, and have more preferable characteristics.

[0520] In Examples 1 to 8, the maximum and minimum values ​​of the reflectivity of the protective film forming film for light (420 to 700 nm) are approximately equal to the maximum and minimum values ​​of the reflectivity of the cured product of the protective film forming film for light (420 to 700 nm), respectively, and the wavelengths of the light at this time are the same. That is, the light reflectivity characteristics of these protective film forming films are almost unchanged before and after curing.

[0521] In Examples 1 to 8, the maximum value of the transmittance of the protective film forming film to light (420 to 700 nm) is approximately equal to the maximum value of the transmittance of the cured product of the protective film forming film to light (420 to 700 nm). That is, the light transmission characteristics of these protective film forming films are almost unchanged before and after curing.

[0522] In Examples 1 to 8, the color tones of both surfaces of the protective film-forming film are single, and these protective film-forming films are advantageous in that the printing can be clearly confirmed with the naked eye, that it is easy to manufacture, and that the color tones of the workpiece with a protective film made from one workpiece with a protective film-forming film are uniform.

[0523] In contrast, in Comparative Examples 1 to 2, the reflectivity of the light (420 to 700 nm) of the cured product of the protective film-forming film is 45.0% or more, and the visual inhibition of the chip with the protective film in the light-emitting device is good. However, the absorptivity of the light (532 nm) of the cured product is 1.8% or less, and the absorptivity of the light (1064 nm) of the cured product is 3.9% or less, and the laser (532 nm) printing visibility and the laser (1064 nm) printing visibility are poor, whether it is direct printing or printing across the support sheet. That is, the protective film-forming film of Comparative Examples 1 to 2 cannot fully apply dark printing to the protective film.

[0524] The protective film-forming films of Comparative Examples 1 and 2 contain a white pigment as a colorant (J), but do not contain a light absorber.

[0525] Industrial Applicability

[0526] The present invention can be used as a protective film for protecting a workpiece mounted on a circuit board.

Claims

1. A protective film-forming film for forming a protective film at any position of a workpiece obtained by processing a workpiece, wherein: When the protective film-forming film is curable, the reflectivity of the cured product of the protective film-forming film in the full wavelength range of 420 to 700 nm is 22% or more, and the absorptivity of the cured product in any one or both of the wavelengths of 532 nm and 1064 nm is 7% or more, When the protective film-forming film is non-curable, the reflectivity of the protective film-forming film in the entire wavelength range of 420 to 700 nm is 22% or more, and the absorptivity of the protective film-forming film in any one or both of the wavelengths of 532 nm and 1064 nm is 7% or more.

2. The protective film-forming film according to claim 1, wherein When the protective film-forming film is curable, the transmittance of the cured product of the protective film-forming film in the entire wavelength range of 420 to 700 nm is 40% or less. When the protective film-forming film is non-curable, the transmittance of light of the protective film-forming film 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. The protective film-forming film according to claim 1 or 2, wherein: When the protective film-forming film is curable, the difference between the maximum value and the minimum value of the reflectivity of the cured product of the protective film-forming film for light 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 value and the minimum value of the reflectance of the protective film-forming film for light in the wavelength range of 420 to 700 nm is 20% or less.

5. The protective film-forming film according to claim 1 or 2, wherein: The protective film-forming film contains a carbon material, In the protective film-forming film, a content of the carbon material is 0.1% by mass or less relative to the total mass of the protective film-forming film.

6. A method for producing a workpiece with a protective film, the method comprising using the protective film-forming film according to claim 1 or 2, wherein: When the protective film-forming film is curable, the cured product of the protective film-forming film is the protective film, and when the protective film-forming film is non-curable, the protective film-forming film attached to the workpiece is the protective film. In the manufacturing method, the protective film-forming film is attached to the workpiece. Printing the protective film-forming film or the protective film after being attached to the workpiece, The workpiece processed product is manufactured by processing the workpiece to which the protective film forming film is attached. cutting off the protective film-forming film or the protective film attached to the workpiece, When the protective film-forming film is curable, the protective film-forming film attached to the workpiece is further cured to form the protective film.

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