Protective film forming film and method for manufacturing substrate device

Abstract

To provide a protective film forming film for forming a protective film with high light reflectance in a workpiece with the protective film having a workpiece and the protective film provided on the workpiece, and that can suppress loss of device design even when the protective film is heated at a high temperature of about 260°C.SOLUTION: A protective film forming film 13 is a thermosetting protective film forming film 13, and when the protective film, which is the thermosetting product of the protective film forming film 13, is heated at 260°C for 5 minutes and the optical reflectance of the protective film after heating is measured, the optical reflectance is equal to or more than 26% in the entire wavelength range from 400 to 700 nm.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

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

[0003] In such a case, for example, a protective film-forming film for forming a protective film is attached to the surface of the workpiece opposite to the surface having the protruding electrodes, such as the back surface of a wafer, and then the workpiece is processed to produce a workpiece. The protective film-forming film is cured as necessary, and the protective film-forming film or the protective film is cut to produce a workpiece with a protective film, which includes the workpiece and a protective film provided on the surface opposite to the surface having the protruding electrodes. When the protective film-forming film is thermosetting, the protective film is thermally cured to form a protective film. An example of a workpiece with a protective film is a semiconductor chip with a protective film, which includes a semiconductor chip and a protective film provided on the back surface of the semiconductor chip. Thereafter, the protruding electrodes in the workpiece with a protective film are brought into contact with a circuit board, and the workpiece with a protective film is heated at a high temperature of about 260°C to melt the protruding electrodes, and the workpiece with a protective film is connected to the circuit board. When the protruding electrodes are solder balls, this heating process is called a solder reflow process, a solder melting process, or the like. As described above, the workpiece with the protective film is mounted on the circuit board, and then, through normal processes, a substrate device such as a semiconductor device including the workpiece with the protective film is manufactured.

[0004] However, in the course of use, the protective film-forming film may have defects in its appearance. Therefore, protective film-forming films capable of suppressing such defects in appearance depending on the application have been studied. For example, when a workpiece with a protective film-forming film (a workpiece provided with a protective film-forming film) is transported, an adsorption means may be brought into contact with the protective film-forming film, and the workpiece with the protective film-forming film may be fixed by adsorption and transported. At this time, adsorption marks may remain on the protective film-forming film, and if the adsorption marks are visible, this may cause a problem in appearance. In response to such problems, a protective film-forming film capable of suppressing the visibility of adsorption marks has been disclosed (see Patent Document 1). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent Publication No. 2021-158181 Summary of the Invention [Problem to be solved by the invention]

[0006] On the other hand, circuit boards used in light-emitting devices such as LEDs (light-emitting diodes) often have a high light reflectance, such as being white. In this case, the protective film in the workpiece with protective film faces in the same direction as the surface of the circuit board, so that its presence is not noticeable on the circuit board and it is desired that the protective film has a high light reflectance like the circuit board so as to improve the design. However, in the heating process for melting the above-mentioned protruding electrodes, the protective film may discolor, impairing the design of the device. In contrast, the protective film-forming film disclosed in Patent Document 1 does not aim to solve such problems.

[0007] The present invention aims to provide a protective film-forming film for forming a protective film having high light reflectance in a protective film-attached workpiece comprising a workpiece and a protective film provided on the workpiece, which can prevent damage to the design of a device even when the protective film is heated at a high temperature of approximately 260°C. [Means for solving the problem]

[0008] In order to solve the above problems, the present invention employs the following configuration. [1] A thermosetting protective film-forming film, wherein when a protective film, which is a thermosetting product of the protective film-forming film, is heated at 260°C for 5 minutes and the light reflectance of the protective film after heating is measured, the light reflectance is 26% or more over the entire wavelength range of 400 to 700 nm. [2] The protective film-forming film according to [1], wherein the protective film-forming film contains a white pigment. [3] The protective film-forming film according to [1] or [2], wherein the protective film-forming film is for forming a protective film at any location on a workpiece obtained by processing a workpiece, and a workpiece with a protective film, which comprises the workpiece and the protective film provided at any location on the workpiece, is for mounting on a circuit board, and the light reflectance of the circuit board in the entire wavelength range of 400 to 700 nm is 30% or more. [4] The protective film-forming film described in any one of [1] to [3], wherein the content ratio of the imidazole-based curing accelerator to the total mass of the protective film-forming film is less than 0.3 mass%.

[0009] [5] The protective film-forming film according to any one of [1] to [4], wherein the protective film-forming film contains a thermal base generator. [6] After heating the protective film at 200° C. for 5 minutes, the optical reflectance RL(x) is measured at every 1 nm wavelength in the entire wavelength range of 400 to 700 nm, and after heating the protective film at 260° C. for 5 minutes, the optical reflectance RH(x) is measured at every 1 nm wavelength in the entire wavelength range of 400 to 700 nm, and the following formula is calculated from the RL(x) and RH(x) at the same wavelength: Change in light reflectance (%) = ((RL(x)-RH(x)) / RL(x) x 100) The protective film-forming film according to any one of [1] to [5], wherein, when the rate of change in light reflectance for each wavelength is calculated by the above, the maximum value among the absolute values ​​of all the rates of change is 18% or less. [7] The protective film-forming film according to any one of [1] to [6], wherein when the light reflectance RH(x) of the protective film after heating at 260°C for 5 minutes is measured at wavelength intervals of 1 nm over the entire wavelength range of 400 to 700 nm, the difference between the maximum value RH(x)max of the light reflectance RH(x) and the minimum value RH(x)min of the light reflectance RH(x) is 13% or less.

[0010] [8] A manufacturing method of a substrate device using a protective film-forming film or a composite sheet for forming a protective film, the protective film-forming film being the protective film-forming film according to any one of [1] to [7], the composite sheet for forming a protective film being configured to include a support sheet and the protective film-forming film according to any one of [1] to [7] provided on one surface of the support sheet, the manufacturing method including a bonding step of bonding the protective film-forming film not constituting the composite sheet for forming a protective film, or the protective film in the composite sheet for forming a protective film, to a surface of a work opposite to a surface having a protruding electrode, a thermal curing step of thermally curing the protective film to form a protective film after the bonding step, and a thermal curing step of thermally curing the protective film to form a protective film, and a processing sheet being attached to a surface of the protective film or protective film opposite to the work side when the protective film-forming film not constituting the composite sheet for forming a protective film is used after the bonding step, and the work is processed on the processing sheet to produce a workpiece, the protective film-forming film or protective film being cut, and the protective film being cut. When a forming composite sheet is used, the method for manufacturing a substrate device includes a processing and cutting step of processing the work on the support sheet to produce a workpiece, and cutting the protective film-forming film or protective film to produce a workpiece with a protective film-forming film comprising the workpiece and the protective film after cutting provided on the surface of the workpiece opposite to the surface having the protruding electrode, or a workpiece with a protective film comprising the workpiece and the protective film after cutting provided on the surface of the workpiece opposite to the surface having the protruding electrode, a pick-up step of separating the workpiece with the protective film-forming film or the workpiece with the protective film from the processing sheet or support sheet after the processing and cutting steps, and a mounting step of contacting the protruding electrode in the workpiece with the protective film with a circuit board, and then heating the workpiece with the protective film to melt the protruding electrode and connect it to the circuit board, after the pick-up step and the heat-curing step. Effect of the Invention

[0011] According to the present invention, there is provided a protective film forming film for forming a protective film having high light reflectance in a protective film-attached workpiece comprising a workpiece and a protective film provided on the workpiece, and the protective film forming film can suppress impairment of the design of the device even when the protective film is heated at a high temperature of approximately 260°C. [Brief description of the drawings]

[0012] [Figure 1] 1 is a cross-sectional view showing a schematic example of a protective film-forming film according to an embodiment of the present invention. [Diagram 2] 1 is a cross-sectional view showing a schematic example of a composite sheet for forming a protective film provided with a protective film-forming film according to one embodiment of the present invention. [Diagram 3] 1A to 1C are cross-sectional views for illustrating an example of a method for manufacturing a substrate device according to an embodiment of the present invention. [Figure 4] 11A to 11C are cross-sectional views for illustrating a schematic example of a method for manufacturing a substrate device according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] ◇Protective film The protective film-forming film according to one embodiment of the present invention is thermosetting, and when a protective film, which is a thermosetting product of the protective film-forming film, is heated at 260°C for 5 minutes and the light reflectance of the protective film after heating is measured, the light reflectance is 26% or more over the entire wavelength range of 400 to 700 nm. The protective film-forming film of this embodiment can be laminated with a support sheet to form a composite sheet for forming a protective film, for example, as described below.

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

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

[0016] Examples of the wafer include semiconductor wafers made of elemental semiconductors such as silicon, germanium, and selenium, and compound semiconductors such as GaAs, GaP, InP, CdTe, ZnSe, and SiC; and insulating wafers made of insulators such as sapphire and glass. For example, if the workpiece is a semiconductor wafer, the workpiece artifacts may include semiconductor chips. A circuit is formed on one surface of each of these wafers, and in this specification, the surface of the wafer on which the circuit is formed is referred to as the "circuit surface," and the surface of the wafer opposite the circuit surface is referred to as the "back surface." The wafer is divided into chips by dicing or other means. In this specification, as in the case of the wafer, the surface of the chip on which the circuit is formed is referred to as the "circuit surface," and the surface of the chip opposite the circuit surface is referred to as the "back surface." Both the circuit surface of the wafer and the circuit surface of the chip are provided with protruding electrodes such as bumps, pillars, etc. The protruding electrodes are preferably made of solder.

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

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

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

[0020] Circuit boards in light-emitting devices have a high visible light reflectance and are often white in color. For example, a typical circuit board has a light reflectance of 30% or more over the entire wavelength range of 400 to 700 nm. In contrast, in the protective film obtained using the protective film-forming film of this embodiment, the absorption of visible light is suppressed, and the protective film is preferably white. Therefore, a workpiece with a protective film having such a protective film is not noticeable on a circuit board in a light-emitting device, and the design of the device including the workpiece with the protective film is high. Furthermore, the design of the device including the workpiece with the protective film after heating at a high temperature of about 260°C is also high. In this specification, the effect of the protective film maintaining the high design of the device even after heating (i.e., the effect of suppressing the loss of the design of the device) is sometimes referred to as the "design maintaining effect".

[0021] On the other hand, when mounting a protective film-attached workpiece having protruding electrodes such as bumps on a circuit board by connecting the protruding electrodes to connection pads on the circuit board, the protruding electrodes in the protective film-attached workpiece are brought into contact with the circuit board and the protective film-attached workpiece is heated at a high temperature of about 260° C. to melt the protruding electrodes (for example, in a solder reflow (melting) process), and the protective film-attached workpiece is connected to the circuit board. In this embodiment, heating at a high temperature of about 260° C. includes heating for melting such protruding electrodes.

[0022] In this specification, the protective film after being heated at a high temperature of about 260° C. may be referred to as a "heated protective film."

[0023] That is, when the workpiece with a protective film is to be mounted on a circuit board and the circuit board has a light reflectance of 30% or more in the entire wavelength range of 400 to 700 nm, the protective film-forming film of this embodiment is particularly suitable for manufacturing the workpiece with a protective film. In such an application, the protective film-forming film of this embodiment has a particularly high effect of maintaining the design of the device.

[0024] <<RH(x)min> > When the protective film, which is a thermosetting product of the protective film-forming film of this embodiment, is heated at 260° C. for 5 minutes and the light reflectance of the protective film after heating is measured, the light reflectance is 26% or more in the entire wavelength range of 400 to 700 nm. In other words, the minimum value of the light reflectance of the protective film after heating in the entire wavelength range of 400 to 700 nm is 26% or more. Therefore, for example, when the optical reflectance of the protective film after heating at 260°C for 5 minutes is measured at every 1 nm wavelength in the entire wavelength range of 400 to 700 nm, and the optical reflectance at a wavelength of x nm (x is any integer between 400 and 700) is defined as optical reflectance RH(x) (sometimes simply referred to as "RH(x)" in this specification), all optical reflectances RH(x) are 26% or more. In other words, the minimum value (sometimes referred to as "RH(x)min" in this specification) of all optical reflectances RH(x) is 26% or more. As described above, the protective film formed from the protective film-forming film of this embodiment has high light reflectance even when heated at a high temperature of about 260°C.

[0025] RH(x)min is preferably 27.5% or more (the light reflectance of the protective film after heating at 260°C for 5 minutes is preferably 27.5% or more in the entire wavelength range of 400 to 700 nm), and may be, for example, either 29% or more or 31% or more. The higher RH(x)min, the higher the effect of maintaining the design of the protective film. On the other hand, the upper limit of RH(x)min is not particularly limited. For example, a protective film-forming film having RH(x)min of 50% or less (the light reflectance of the protective film after heating at 260°C for 5 minutes is 50% or less in the entire wavelength range of 400 to 700 nm) can be more easily realized. In one embodiment, RH(x)min may be, for example, any one of 26% to 50%, 27.5 to 50%, 29 to 50%, and 31 to 50%, although these are merely examples of RH(x)min.

[0026] <<ΔRH(x)>> The difference between the maximum value of all light reflectances RH(x) (sometimes referred to herein as "RH(x)max") and the minimum value of all light reflectances RH(x) (sometimes referred to herein as "light reflectance difference ΔRH(x)" or simply "ΔRH(x)") may be, for example, 17% or less, preferably 13% or less, or may be either 12% or less, or 11% or less. The smaller ΔRH(x) is, the greater the effect of maintaining the design of the protective film tends to be. On the other hand, the lower limit of ΔRH(x) is not particularly limited. For example, a protective film having a ΔRH(x) of 3% or more can be more easily realized. In one embodiment, ΔRH(x) may be, for example, any one of 3 to 17%, 3 to 13%, 3 to 12%, and 3 to 11%, although these are merely examples of ΔRH(x).

[0027] The curing conditions when the protective film-forming film of this embodiment is thermally cured to form a protective film are not particularly limited, as long as the degree of curing is sufficient to allow the protective film to fully perform its function, and may be appropriately selected depending on the type of thermosetting protective film-forming film. For example, the heating temperature during thermal curing of the protective film-forming film is preferably 100 to 200° C., more preferably 110 to 170° C., and particularly preferably 120 to 150° C. The heating time during thermal curing is preferably 0.5 to 5 hours, more preferably 0.5 to 4 hours, and particularly preferably 1 to 3 hours. The protective film formed by thermal curing is preferably cooled slowly to room temperature. The method of cooling is not particularly limited, and the protective film may be cooled naturally.

[0028] The protective film before heating, which is used for the measurement of the light reflectance described above, is preferably a cured product obtained by heating the protective film-forming film of this embodiment at 140° C. for 2 hours.

[0029] <<RH(x)max> > Although RH(x)max is not particularly limited, it is preferable that the value satisfies the above ΔRH(x). For example, RH(x)max may be any one of 55% or less, 50% or less, and 43% or less, or may be 39% or more, or any one of 39 to 55%, 39 to 50%, and 39 to 43%.

[0030] <<|Rate of change in light reflectance|max>> The protective film, which is a thermosetting product of the protective film-forming film of this embodiment, is heated at 200° C. for 5 minutes, and the light reflectance of the protective film after heating is measured at wavelengths of 1 nm in the entire wavelength range of 400 to 700 nm. The light reflectance at a wavelength of x nm (x is an integer of 400 to 700) is defined as light reflectance RL(x) (sometimes simply referred to as "RL(x)" in this specification), and is expressed by the following formula: Change in light reflectance (%) = ((RL(x)-RH(x)) / RL(x) x 100) When the rate of change in light reflectance is calculated for each wavelength by the above, the maximum value of all the absolute values ​​of the rates of change (sometimes referred to as "|rate of change in light reflectance|max" in this specification) is preferably 18% or less, more preferably 15% or less, and may be, for example, either 12% or less or 9% or less. The smaller the |rate of change in light reflectance|max, the more the color variation of the heated protective film is suppressed even if the heating environment of the protective film at high temperature varies, and the more uniform the appearance of the heated protective film becomes. Therefore, for example, when multiple workpieces with protective film are heated at high temperature, even if the heating temperature varies as may normally occur, the color variation of the heated protective film among these multiple workpieces with protective film is suppressed, and the design maintenance effect of the device is easily achieved uniformly.

[0031] The |rate of change in light reflectance|max being 18% or less is synonymous with all "rates of change in light reflectance" being -18% to 18%.

[0032] On the other hand, although the |rate of change in light reflectance|max is 0% or more, for example, a protective film-forming film in which the |rate of change in light reflectance|max is 4% or more can be more easily realized. In one embodiment, the |rate of change in light reflectance|max may be, for example, any one of 4 to 18%, 4 to 15%, 4 to 12%, and 4 to 9% or less, although these are merely examples of the |rate of change in light reflectance|max.

[0033] The rate of change (%) of optical reflectance is calculated using RL(x) and RH(x) at the same wavelength (same x). The rate of change (%) of optical reflectance is calculated 301 times using 301 combinations from the combination of RL(400) and RH(400) to the combination of RL(700) and RH(700) in the wavelength range of 400 to 700 nm. Then, from these 301 rates of change of optical reflectance, all (i.e., 301) |rates of change of optical reflectance| are calculated, and the maximum value among them is taken as |rate of change of optical reflectance|max.

[0034] In this specification, examples of cases in which variation occurs in the high-temperature heating environment of the protective film include a case in which the heating temperature of the protective film varies depending on its position even though the protective film is within the same heating space, and a case in which the heating temperature of the protective film varies over time even though the fixed position of the protective film within the heating space remains unchanged.

[0035] In the manufacturing process of a substrate device such as a semiconductor device having a workpiece with a protective film, the protruding electrodes in the workpiece with a protective film are brought into contact with a circuit board, and the workpiece with a protective film is heated at a high temperature of about 260° C. to melt the protruding electrodes, thereby connecting (mounting) the workpiece with a protective film to the circuit board. When the protruding electrodes are solder balls, this heating process is called a solder reflow process, a solder melting process, or the like. In this heating process, for example, the circuit board having the workpiece with a protective film is placed on a conveyor for transport and is carried into a heating furnace, whereby the workpiece with a protective film is heated at a high temperature. A more specific case in which the above-mentioned heating environment varies is, for example, a case in which the heating temperature of the workpiece with a protective film differs depending on the position of the workpiece with a protective film on the conveyor for transport.

[0036] Furthermore, in recent years, the connection (mounting) position of the workpiece with the protective film on the circuit board is adjusted not only in two directions in a plane but also in the height direction, and the connection position tends to be adjusted three-dimensionally to become more complex. In such cases, the above-mentioned variation in the heating environment at high temperatures becomes more likely to occur.

[0037] The light reflectance of the protective film after heating, such as RH(x) and RL(x), and the light reflectance of the protective film before heating can be adjusted, for example, by adjusting the type and content of the components contained in the protective film-forming film. In particular, the protective film-forming film contains a colorant (I) described later, and the light reflectance of the protective film after heating and before heating can be adjusted by adjusting the type and content of the colorant (I) in the protective film-forming film. When the colorant is a pigment, the light reflectance of the protective film after heating and before heating can also be adjusted by its particle size. For example, in the protective film-forming film, a colorant (I) with high whiteness is used, and the content thereof is increased, thereby increasing the light reflectance of the protective film after heating and before heating. For example, when the protective film-forming film contains a white pigment, the light reflectance of the protective film after heating and before heating can be more easily increased. That is, the protective film-forming film of the present embodiment preferably contains a white pigment. Details of the white pigment will be described later. By employing a method similar to that for adjusting RH(x), RL(x), etc., ΔRH(x) and |rate of change in light reflectance|max can also be adjusted.

[0038] For example, the protective film-forming film may not contain a component (sometimes referred to as a "discoloration component" in this specification) that easily discolors when heated (e.g., at about 200 to 260°C), or, if the protective film-forming film contains a discoloration component, the content of the discoloration component in the protective film-forming film may be reduced, thereby making it easier to suppress a reduction in the light reflectance of the protective film after heating, such as RH(x) and RL(x).

[0039] The color-changing component may, for example, be an imidazole-based compound. In this specification, the term "imidazole-based compound" is a concept that encompasses imidazole (also known as 1,3-diazole) and its derivatives.

[0040] In this specification, when a structure in which one or more hydrogen atoms in a certain specific compound are replaced with a group other than a hydrogen atom is assumed, the compound having such a replaced structure is referred to as a "derivative" of the above-mentioned specific compound. In this specification, unless otherwise specified, the term "group" includes not only an atomic group formed by bonding multiple atoms, but also a single atom.

[0041] Examples of the substituent in the imidazole derivative (the substituent substituting the hydrogen atom in the imidazole) include an alkyl group, an aryl group, an aralkyl group, a hydroxyalkyl group, a hydroxyaryl group, and a hydroxyaralkyl group. The number of hydrogen atoms substituted by hydroxyl groups in the hydroxyalkyl group, hydroxyaryl group and hydroxyaralkyl group is not particularly limited as long as it is equal to or less than the number of hydrogen atoms in the unsubstituted alkyl group, aryl group and aralkyl group, but is preferably 1 to 3.

[0042] Among imidazole compounds, 2-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, etc. are known to be suitable as a curing accelerator, which is a component of a composition for forming a thermosetting protective film-forming film. That is, the protective film-forming film of this embodiment and the protective film-forming composition (III) for forming the film, which will be described later, do not contain an imidazole curing accelerator (a curing accelerator made of an imidazole compound), or, if an imidazole curing accelerator is contained, the content thereof is preferably small.

[0043] In the protective film-forming film, the content ratio of the imidazole-based hardening accelerator (hardening accelerator which is an imidazole-based compound) to the total mass of the protective film-forming film is preferably less than 0.3 mass%, and may be, for example, 0.2 mass% or less or 0.1 mass% or less. The lower the ratio, the higher the effect of suppressing the reduction in the light reflectance of the protective film after heating, such as RH(x) and RL(x). On the other hand, the ratio is 0% by mass or more.

[0044] Regardless of whether the imidazole-based compound is a curing accelerator or not, in the protective film-forming film, the content ratio of the imidazole-based compound to the total mass of the protective film-forming film is preferably in the same numerical range as the content ratio of the imidazole-based curing accelerator to the total mass of the protective film-forming film in the protective film-forming film described above.

[0045] <<Storage modulus E'(23) of protective film>> A test laminate sheet having a thickness of 185 to 215 μm, which is constituted by laminating a plurality of protective film-forming films of the present embodiment in the thickness direction, is heated at 140° C. for 2 hours to thermally cure all of the protective film-forming films constituting the test laminate sheet to form protective films, and a test piece (thickness 185 to 215 μm) having a width of 4.5 mm and a length of more than 20 mm is cut out from the heated (thermally cured) test laminate sheet (thickness 185 to 215 μm), and the test piece is cut at two points with an interval of 20 mm. When the test piece is held at 23° C. and heated at a rate of 3° C. / min from 0° C. to 300° C. at a frequency of 11 Hz, the storage modulus E' of the test piece is measured. When the temperature of the test piece is 23° C., the storage modulus E'(23) may be, for example, 800 MPa or more, but is preferably 1000 MPa or more, and may be, for example, any one of 3000 MPa or more, 5000 MPa or more, 7000 MPa or more, 9000 MPa or more, and 11000 MPa or more. The larger the storage modulus E'(23), the higher the protective performance of the protective film for the work compound.

[0046] The upper limit of the storage modulus E'(23) of the test piece (protective film) is not particularly limited. For example, a protective film-forming film having a storage modulus E'(23) of preferably 14000 MPa or less, more preferably 9000 MPa or less, can be more easily realized. In one embodiment, the storage modulus E'(23) may be, for example, any one of 800 to 14000 MPa, 1000 to 14000 MPa, 3000 to 14000 MPa, 5000 to 14000 MPa, 7000 to 14000 MPa, 9000 to 14000 MPa, and 11000 to 14000 MPa, or any one of 800 to 9000 MPa, 1000 to 9000 MPa, 3000 to 9000 MPa, 5000 to 9000 MPa, and 7000 to 9000 MPa. However, these are only examples of the storage modulus E'(23).

[0047] The thickness of the test piece is preferably 200 μm. However, as long as the thickness of the test piece is about 185 to 215 μm (200±15 μm), the measured value of the storage modulus E'(23) is either exactly the same as or has a negligible small error with respect to the measured value of the storage modulus E'(23) when the thickness of the test piece is 200 μm, regardless of the thickness.

[0048] In this specification, the term "thickness" refers not only to the test specimen but also to the average thickness measured at five randomly selected points on the object, unless otherwise specified, and can be obtained using a constant pressure thickness gauge in accordance with JIS K7130.

[0049] When measuring the storage modulus E', the test piece is held at two points spaced 20 mm apart, which means that the length of the portion of the test piece subject to measurement of the storage modulus E' is 20 mm. The test piece can be held at the two points by using, for example, a known holding means such as a gripping tool. The number of protective film-forming films constituting the test piece is not particularly limited as long as it is two or more, and can be arbitrarily selected according to the thickness of each protective film-forming film. For example, the test piece having a thickness of 200 μm can be produced by using five protective film-forming films having a thickness of 40 μm. In addition, the test piece having a thickness of 200 μm can be produced by using eight protective film-forming films having a thickness of 25 μm. However, these are only examples, and the number and thickness of the protective film-forming films used are not limited to these.

[0050] The storage modulus E' of the protective film, such as the storage modulus E'(23), can be adjusted by adjusting the type and content of the components contained in the protective film-forming film. For example, the protective film-forming film contains a curing accelerator (C) described later, and the storage modulus E' of the protective film can be increased by adjusting the type of the curing accelerator (C) in the protective film-forming film or increasing the content of the curing accelerator (C).

[0051] Among the curing accelerators (C), thermal base generators are particularly advantageous in that they are highly effective in suppressing the decrease in light reflectance of the heated protective film and can increase the storage modulus E'(23) of the protective film. That is, the protective film-forming film of the present embodiment preferably contains a thermal base generator.

[0052] <Thermal base generator> In this specification, the term "thermal base generator" refers to a compound that generates a base by heat and does not fall under the category of the imidazole-based compounds.

[0053] Examples of the thermal base generator include ammonium salts and phosphonium salts. Examples of the ammonium salt include a salt of a base and an acid (a salt that is considered to be formed by the reaction of a base and an acid), and a salt composed of a quaternary ammonium cation (a cation having a structure in which four hydrocarbon groups are bonded to a nitrogen atom) and an anion. The phosphonium salt may be, for example, a salt composed of a phosphonium cation and an anion.

[0054] [base] Among the thermal base generators, examples of the base constituting the ammonium salt include primary amines and derivatives thereof, secondary amines and derivatives thereof, tertiary amines and derivatives thereof, and hydrazine and derivatives thereof.

[0055] Examples of the primary amine include monoalkylamines, monoalkenylamines, monoalkadienylamines, monoarylamines, monoaralkylamines, polyaminoalkanes, and polyaminobenzene derivatives. Examples of the derivatives of primary amines include mono(hydroxyalkyl)amines and monoaminoketones.

[0056] Examples of the monoalkylamine include monoalkylamines having 1 to 8 carbon atoms, which have a structure in which one hydrogen atom in ammonia (NH3) is substituted with a linear or branched alkyl group having 1 to 8 carbon atoms, or a cyclic alkyl group having 3 to 8 carbon atoms. More specific examples of the monoalkylamine include methylamine, ethylamine, n-propylamine, isopropylamine, n-butylamine, isobutylamine, sec-butylamine, tert-butylamine, octylamine, 2-ethylhexylamine, cyclopropylamine, cyclobutylamine, cyclohexylamine, cyclooctylamine, and the like.

[0057] Examples of the monoalkenylamine include monoalkenylamines having 2 to 8 carbon atoms, which have a structure in which one hydrogen atom in ammonia is substituted with a linear or branched alkenyl group having 2 to 8 carbon atoms, or a cyclic alkenyl group having 3 to 8 carbon atoms. More specific examples of the monoalkenylamine include vinylamine (also known as ethenylamine), allylamine (also known as 2-propenylamine), octenylamine, cyclopentenylamine, cyclohexenylamine, and the like.

[0058] Examples of the monoalkadienylamine include monoalkadienylamines having 4 to 8 carbon atoms, which have a structure in which one hydrogen atom in ammonia is substituted with a linear or branched alkadienyl group having 4 to 8 carbon atoms, or a cyclic alkadienyl group having 4 to 8 carbon atoms. More specific examples of the monoalkadienylamine include butadienylamine, pentadienylamine, hexadienylamine, heptadienylamine, octadienylamine, cyclohexadienylamine, and the like.

[0059] Examples of the monoarylamine include monoarylamines having 6 to 12 carbon atoms, which have a structure in which one hydrogen atom in ammonia is substituted with a monocyclic or polycyclic aryl group having 6 to 12 carbon atoms. More specific examples of the monoarylamine include aniline (also known as phenylamine), naphthylamine, toluidine (also known as methylaniline), and the like.

[0060] Examples of the monoaralkylamine include monoaralkylamines having 7 to 13 carbon atoms, which have a structure in which one hydrogen atom in ammonia is substituted with a monocyclic or polycyclic aralkyl group having 7 to 13 carbon atoms. More specific examples of the monoaralkylamine include benzylamine (another name: phenylmethylamine), (naphthylmethyl)amine, and the like.

[0061] Examples of the polyaminoalkane include polyaminoalkanes having 1 to 8 carbon atoms, which have a structure in which two or more hydrogen atoms in a linear or branched alkane having 1 to 8 carbon atoms or a cyclic alkane having 3 to 8 carbon atoms are substituted with amino groups. More specific examples of the polyaminoalkane include ethylenediamine, ethylenetriamine, etc.

[0062] The polyaminobenzene derivatives include, for example, polyaminobenzene derivatives having 6 to 12 carbon atoms and having a structure in which one or more hydrogen atoms (excluding hydrogen atoms in amino groups) in a compound corresponding to the aminobenzene derivative are substituted with amino groups. More specifically, the polyaminobenzene derivatives include, for example, tolylenediamine (another name: diaminotoluene).

[0063] Examples of the mono(hydroxyalkyl)amine include mono(hydroxyalkyl)amines having 1 to 8 carbon atoms, each of which has a structure in which one hydrogen atom (not including a hydrogen atom in an amino group) in the mono(hydroxyalkyl)amine having 1 to 8 carbon atoms is substituted with a hydroxyl group. More specific examples of the mono(hydroxyalkyl)amine include ethanolamine.

[0064] Examples of the monoaminoketone include monoaminoketones having 3 to 8 carbon atoms, which have a structure in which two hydrogen atoms (-H, -H) bonded to the same carbon atom in a monoalkylamine having 3 to 8 carbon atoms are replaced with one oxygen atom (=O). More specific examples of the monoaminoketone include aminoacetone. Examples of the monoalkylamine having 3 to 8 carbon atoms include the monoalkylamines described above having 3 to 8 carbon atoms.

[0065] Examples of the secondary amine include dialkylamines, dialkenylamines, alkylalkenylamines, dialkadienylamines, dialkatrienylamines, alkylalkatrienylamines, alkenylalkadienylamines, diarylamines, diaralkylamines, alkylarylamines, alkylaralkylamines, alkenylarylamines, alkenylaralkylamines, arylalkadienylamines, N-alkylaminoalkanes, N,N'-dialkylaminoalkanes, pyrrolidine, pyrrolidine derivatives, piperidine, piperidine derivatives, piperazine, and piperazine derivatives.

[0066] Examples of the pyrrolidine derivative include alkylpyrrolidines other than 1-alkylpyrrolidine, such as 2-methylpyrrolidine and 3-methylpyrrolidine. Examples of the piperidine derivative include alkylpiperidines other than 1-alkylpiperidine, such as 2-methylpiperidine, 3-methylpiperidine, and 4-methylpiperidine. Examples of the piperazine derivative include alkylpiperazines such as 2-ethylpiperazine, which do not fall into either 1-alkylpiperazines or 1,4-dialkylpiperazines.

[0067] The alkyl group, alkenyl group, alkadienyl group, aryl group and aralkyl group in the secondary amine include the same as the alkyl group, alkenyl group, alkadienyl group, aryl group and aralkyl group in the above-mentioned primary amine, respectively. Examples of the alkadienyl group in the secondary amine include groups having a structure in which one single bond (CC) between carbon atoms in the alkadienyl group in the primary amine is replaced with a double bond (C=C). When the secondary amine has two groups classified as the same type, such as two alkyl groups, these two groups may be the same or different.

[0068] Examples of the tertiary amine include trialkylamines, trialkenylamines, dialkylalkenylamines, alkyldialkenylamines, trialcadienylamines, dialkylalkatrienylamines, alkyldialkatrienylamines, dialkenylalkadienylamines, alkenyldialkadienylamines, triarylamines, triaralkylamines, dialkylarylamines, alkyldiarylamines, dialkylaralkylamines, alkyldiaralkylamines, dialkenylarylamines, alkenyldiarylamines, dialkenylaralkylamines, alkenyldiaralkylamines, diarylalkadienylamines, aryldialkadienylamines, N,N-dialkylaminoalkanes, N,N,N',N'-tetraalkylaminoalkanes, quinuclidine, pyrrolidine derivatives, piperidine derivatives, and piperazine derivatives.

[0069] The pyrrolidine derivatives include, for example, 1-alkylpyrrolidines such as 1-methylpyrrolidine. The piperidine derivatives include, for example, 1-alkylpiperidines such as 1-methylpiperidine. Examples of the piperazine derivatives include 1-alkylpiperazines and 1,4-dialkylpiperazines.

[0070] The alkyl group, alkenyl group, alkadienyl group, aryl group and aralkyl group in the tertiary amine include the same as the alkyl group, alkenyl group, alkadienyl group, aryl group and aralkyl group in the primary amine described above, respectively. The alkatrienyl group in the tertiary amine may be the same as the alkatrienyl group in the secondary amine described above. When the tertiary amine has a plurality of groups classified as the same type, such as 2 to 3 alkyl groups, these plurality of groups may be all the same, all different, or only some of them may be the same.

[0071] The base constituting the thermal base generator is preferably a primary amine, a derivative of a primary amine, a secondary amine, a derivative of a secondary amine, a tertiary amine or a derivative of a tertiary amine, more preferably a cycloamidine, further preferably 1,8-diazabicyclo[5.4.0]undec-7-ene (also known as 1,8-diazabicyclo[5.4.0]-7-undecene, DBU (registered trademark)), a derivative of 1,8-diazabicyclo[5.4.0]undec-7-ene, 1,5-diazabicyclo[4.3.0]non-5-ene (also known as DBN), or a derivative of 1,5-diazabicyclo[4.3.0]non-5-ene, and particularly preferably 1,8-diazabicyclo[5.4.0]undec-7-ene, or a derivative of 1,8-diazabicyclo[5.4.0]undec-7-ene.

[0072] [acid] In the thermal base generator, the acid constituting the ammonium salt may be either an organic acid or an inorganic acid.

[0073] Examples of the organic acid include carboxylic acids and derivatives thereof, such as aliphatic carboxylic acids, aliphatic carboxylic acid derivatives, aromatic carboxylic acids, and aromatic carboxylic acid derivatives; sulfonic acids, such as aliphatic sulfonic acids and aromatic sulfonic acids; and aromatic hydroxy compounds, such as phenol, phenol derivatives, naphthol, and naphthol derivatives.

[0074] In this specification, the term "aromatic carboxylic acid" refers to a compound in which a carboxy group is directly bonded to an aromatic cyclic group, and a compound in which a carboxy group is bonded to an aromatic cyclic group via a group other than the aromatic cyclic group. An "aromatic hydroxy compound" refers to a compound in which a hydroxy group is directly bonded to an aromatic cyclic group.

[0075] The aromatic carboxylic acid may be an aromatic monocarboxylic acid having one carboxy group, or an aromatic polycarboxylic acid having two or more carboxy groups. Examples of the aromatic monocarboxylic acid include aromatic monocarboxylic acids having an aromatic cyclic group with 6 to 12 carbon atoms, such as benzoic acid (another name: benzenecarboxylic acid), p-toluic acid (another name: 4-methylbenzenecarboxylic acid), m-toluic acid (another name: 3-methylbenzenecarboxylic acid), o-toluic acid (another name: 2-methylbenzenecarboxylic acid), 1-naphthoic acid (another name: 1-naphthalenecarboxylic acid), 2-naphthoic acid (another name: 2-naphthalenecarboxylic acid), and cinnamic acid (another name: 3-phenyl-2-propenoic acid). Examples of the aromatic polycarboxylic acid include aromatic polycarboxylic acids having an aromatic cyclic group with 6 to 12 carbon atoms, such as phthalic acid (another name: benzene-1,2-dicarboxylic acid), isophthalic acid (another name: benzene-1,3-dicarboxylic acid), terephthalic acid (another name: benzene-1,4-dicarboxylic acid), 1,4-naphthalenedicarboxylic acid (another name: naphthalene-1,4-dicarboxylic acid), and 2,3-naphthalenedicarboxylic acid (another name: naphthalene-2,3-dicarboxylic acid).

[0076] Examples of the aromatic carboxylic acid derivatives include aromatic hydroxy monovalent carboxylic acids having an aromatic ring group with 6 to 12 carbon atoms, such as salicylic acid (also known as 2-hydroxybenzenecarboxylic acid), 6-hydroxy-2-naphthoic acid (also known as 6-hydroxynaphthalene-2-carboxylic acid), 3-hydroxy-2-naphthoic acid (also known as 3-hydroxynaphthalene-2-carboxylic acid), and mandelic acid (also known as 2-hydroxy-2-phenylacetic acid). Examples of the aromatic carboxylic acid derivatives include aromatic hydroxy polyvalent carboxylic acids having an aromatic cyclic group with 6 to 12 carbon atoms, such as 3-hydroxy-2,7-naphthalenedicarboxylic acid. In this specification, a compound having both a carboxy group and a hydroxyl group is classified as a carboxylic acid derivative.

[0077] The aliphatic carboxylic acid may be an aliphatic monocarboxylic acid having one carboxy group, or an aliphatic polycarboxylic acid having two or more carboxy groups. The aliphatic carboxylic acid may be either a saturated aliphatic carboxylic acid or an unsaturated aliphatic carboxylic acid. Examples of the aliphatic carboxylic acid include saturated aliphatic monocarboxylic acids such as formic acid, acetic acid, propionic acid, isovaleric acid (also known as isopentanoic acid), 2-ethylhexanoic acid, and stearic acid; saturated aliphatic polycarboxylic acids (for example, saturated aliphatic dicarboxylic acids) such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, azelaic acid, suberic acid, and sebacic acid; unsaturated aliphatic monocarboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, palmitoleic acid, oleic acid, linoleic acid, and linolenic acid; and unsaturated aliphatic polycarboxylic acids (for example, unsaturated aliphatic dicarboxylic acids) such as fumaric acid and maleic acid.

[0078] Examples of the aliphatic carboxylic acid derivatives include aliphatic halocarboxylic acids such as chloroacetic acid, trichloroacetic acid, fluoroacetic acid, 2-chloropropionic acid, and 3-chloropropionic acid; aliphatic alkoxycarboxylic acids such as methoxyacetic acid; aliphatic aryloxycarboxylic acids such as phenoxyacetic acid; aliphatic cyanocarboxylic acids such as cyanoacetic acid; and aliphatic hydroxycarboxylic acids such as glycolic acid, lactic acid, citric acid, and tartaric acid (D-tartaric acid, L-tartaric acid, and mesotartaric acid).

[0079] The aromatic sulfonic acid may be an aromatic monovalent sulfonic acid having one sulfo group (-SO3H) or an aromatic polyvalent sulfonic acid having two or more sulfo groups, but is preferably an aromatic monovalent sulfonic acid. Examples of the aromatic sulfonic acid include benzenesulfonic acids or alkylbenzenesulfonic acids having an aromatic cyclic group with 6 to 15 carbon atoms, such as octylbenzenesulfonic acid, butylbenzenesulfonic acid, toluenesulfonic acid, and benzenesulfonic acid. Examples of the aliphatic sulfonic acid include saturated aliphatic monofunctional sulfonic acids such as methanesulfonic acid, 1-propanesulfonic acid, 1-pentanesulfonic acid, and 1-octanesulfonic acid.

[0080] Of the aromatic hydroxy compounds, the phenol derivative means a compound having a structure in which one or more hydrogen atoms in phenol (C6H5OH) are replaced with groups other than hydrogen atoms. Among the aromatic hydroxy compounds, the naphthol derivatives are 1-naphthol or 2-naphthol (C 10 It refers to a compound having a structure in which one or more hydrogen atoms in the alkyl group (H7OH) are replaced with a group other than a hydrogen atom.

[0081] The aromatic hydroxy compound may be an aromatic monohydroxy compound having one hydroxyl group, or an aromatic polyhydroxy compound having two or more hydroxyl groups. Examples of the aromatic monohydroxy compound include aromatic monohydroxy compounds having an aromatic ring group with 6 to 12 carbon atoms (phenol, phenol derivatives, naphthol), such as phenol, p-cresol (also known as 4-methylphenol), m-cresol (also known as 3-methylphenol), o-cresol (also known as 2-methylphenol), 2,3-xylenol (also known as 2,3-dimethylphenol), 2,4-xylenol (also known as 2,4-dimethylphenol), 2,5-xylenol (also known as 2,5-dimethylphenol), 2,6-xylenol (also known as 2,6-dimethylphenol), 3,4-xylenol (also known as 3,4-dimethylphenol), 3,5-xylenol (also known as 3,5-dimethylphenol), 1-naphthol, and 2-naphthol. Examples of the aromatic polyhydroxy compounds include aromatic polyhydroxy compounds having an aromatic cyclic group with 6 to 12 carbon atoms (phenol derivatives, naphthol derivatives), such as catechol (also known as 1,2-dihydroxybenzene, resorcinol (also known as 1,3-benzenediol), and 1,5-dihydroxynaphthalene (also known as 1,5-naphthalenediol)).

[0082] Examples of the inorganic acid include hydrogen halides such as hydrogen fluoride, hydrogen chloride, hydrogen bromide, and hydrogen iodide; sulfuric acid; and phosphoric acid.

[0083] The acid constituting the thermal base generator is preferably an organic acid, and more preferably a carboxylic acid, a carboxylic acid derivative, or an aromatic hydroxy compound. When the acid is an aromatic carboxylic acid or a derivative thereof, it is more preferable that the acid is an aromatic polycarboxylic acid or a derivative thereof, and when the acid is an aliphatic carboxylic acid or a derivative thereof, it is more preferable that the acid is an aliphatic monocarboxylic acid or a derivative thereof. When the acid is an aromatic hydroxy compound, it is more preferred that the acid is a phenol or a derivative thereof.

[0084] [Base and acid combinations] In terms of being able to more easily increase the storage modulus E' of the protective film, the salt of the base and acid among the thermal base generators is preferably a salt of cycloamidine and an organic acid, more preferably a salt of DBU (registered trademark) or a derivative thereof and an organic acid, even more preferably a salt of DBU (registered trademark) or a derivative thereof and a carboxylic acid, a carboxylic acid derivative, or an aromatic hydroxy compound, particularly preferably a salt of DBU (registered trademark) or a derivative thereof and an aromatic carboxylic acid, an aromatic carboxylic acid derivative, an aliphatic carboxylic acid, an aliphatic carboxylic acid derivative, a phenol, or a phenol derivative, and most preferably a salt of DBU (registered trademark) or a derivative thereof and an aromatic polycarboxylic acid, an aromatic polycarboxylic acid derivative, an aliphatic monocarboxylic acid, an aliphatic monocarboxylic acid derivative, or a phenol, or

[0085] [Quaternary ammonium cation] Among the thermal base generators, examples of the quaternary ammonium cation constituting the ammonium salt include cations having a structure in which four hydrocarbon groups, such as alkyl groups, aryl groups, or aralkyl groups, are bonded to a nitrogen atom in the base (a nitrogen atom essential for the expression of basic properties). More specifically, the ammonium cation may be, for example, an organic ammonium cation in which four hydrocarbon groups are bonded to a nitrogen atom, such as a tetraalkyl ammonium cation, a trialkyl monoaryl ammonium cation, a dialkyl diaryl ammonium cation, a monoalkyl triaryl ammonium cation, a tetraaryl ammonium cation, a trialkyl monoaralkyl ammonium cation, a dialkyl diaralkyl ammonium cation, a monoalkyl triaralkyl ammonium cation, a tetraaralkyl ammonium cation, a triaralkyl monoaryl ammonium cation, a diaralkyl diaryl ammonium cation, or a monoaralkyl triaryl ammonium cation, etc. However, these are only examples of the ammonium cation.

[0086] [Anions that compose ammonium salts] In the thermal base generator, examples of the anion constituting the ammonium salt include an anion formed by dissociating the acid. More specifically, the anion may be an anion derived from an organic acid such as an aliphatic carboxylic acid, an aliphatic carboxylic acid derivative, an aromatic carboxylic acid, an aromatic carboxylic acid derivative (i.e., a carboxylic acid or a derivative thereof), an aliphatic sulfonic acid, an aromatic sulfonic acid (i.e., a sulfonic acid), a phenol, a phenol derivative, a naphthol or a naphthol derivative (i.e., an aromatic hydroxy compound); a fluoride ion (F - ), chloride ion (Cl - ), bromide ion (Br - ), iodide ion (I - ) (these may be collectively referred to as "halide ions" in this specification), sulfate ions (SO4 2- ), phosphate ion (PO4 3- ), hydrogen phosphate ion (HPO4 2- ) or dihydrogen phosphate ion (H2PO4 - However, these are only examples of the anions.

[0087] [Combination of ammonium cation and anion] In terms of being able to more easily increase the storage modulus E' of the protective film, among the thermal base generators, the salt composed of the quaternary ammonium cation and an anion is preferably a salt composed of the organic ammonium cation and an anion obtained by dissociating an organic acid or an inorganic acid, more preferably a salt composed of a tetraalkylammonium cation, a trialkylmonoarylammonium cation, a dialkyldiarylammonium cation, a monoalkyltriarylammonium cation, or a tetraarylammonium cation and an anion obtained by dissociating a carboxylic acid or a derivative thereof, still more preferably a salt composed of a tetraalkylammonium cation or a trialkylmonoarylammonium cation and an anion obtained by dissociating an aliphatic carboxylic acid or a derivative thereof, and particularly preferably a salt composed of a tetraalkylammonium cation and an anion obtained by dissociating an aliphatic monovalent carboxylic acid or a derivative thereof.

[0088] [Phosphonium cation] Among the thermal base generators, examples of the phosphonium cation constituting the phosphonium salt include cations having a structure in which four hydrocarbon groups, such as alkyl groups, aryl groups, or aralkyl groups, are bonded to a phosphorus atom. More specifically, the phosphonium cation may be, for example, an organic phosphonium cation in which four hydrocarbon groups are bonded to a phosphorus atom, such as a tetraalkylphosphonium cation, a trialkylmonoarylphosphonium cation, a dialkyldiarylphosphonium cation, a monoalkyltriarylphosphonium cation, a tetraarylphosphonium cation, a trialkylmonoaralkylphosphonium cation, a dialkyldiaralkylphosphonium cation, a monoalkyltriaralkylphosphonium cation, a tetraaralkylphosphonium cation, a triaralkylmonoarylphosphonium cation, a diaralkyldiarylphosphonium cation, or a monoaralkyltriarylphosphonium cation. However, these are only examples of the phosphonium cation.

[0089] [Anions that compose phosphonium salts] Among the thermal base generators, examples of the anion constituting the phosphonium salt include the same anions as those constituting the ammonium salts described above.

[0090] [Combination of phosphonium cation and anion] In terms of being able to more easily increase the storage modulus E' of the protective film, the salt composed of the phosphonium cation and an anion among the thermal base generators is preferably a salt composed of the organic phosphonium cation and an anion obtained by dissociating an organic acid or an inorganic acid, more preferably a salt composed of a trialkylmonoarylammonium cation, a dialkyldiarylammonium cation, a monoalkyltriarylammonium cation, a tetraarylammonium cation, a tetraaralkylammonium cation, a triaralkylmonoarylammonium cation, a diaralkyldiarylammonium cation or a monoaralkyltriarylammonium cation, and an anion obtained by dissociating a sulfonic acid or a halide ion, still more preferably a salt composed of a monoalkyltriarylammonium cation, a tetraarylammonium cation or a monoaralkyltriarylammonium cation, and an anion obtained by dissociating an aliphatic sulfonic acid or a halide ion, and particularly preferably a salt composed of a monoalkyltriarylammonium cation or a monoaralkyltriarylammonium cation, and an anion obtained by dissociating a saturated aliphatic monovalent sulfonic acid or a halide ion.

[0091] <<Color tone on both sides of protective film>> The color tone of at least both sides of the protective film-forming film of this embodiment is preferably uniform, and the color tone of the entire protective film-forming film may be uniform. Such a protective film-forming film is advantageous in that the printing can be clearly confirmed by visual inspection in the state of the protective film finally subjected to laser printing. 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 protective film produced from one workpiece with protective film-forming film is all uniform. Both sides of the protective film-forming film are, for example, the same as the first and second sides described below.

[0092] In addition, the term "both sides of the protective film-forming film have the same color tone" means that both sides of the protective film-forming film have the same color tone (the same color tone) over their entire area. In this specification, the color tone of the first surface and the second surface of the protective film-forming film is uniform, which means that the light reflectance of the first surface of the protective film-forming film is measured at wavelengths of 1 nm each in the entire wavelength range of 400 to 700 nm, the light reflectance at a wavelength of x nm (x is any integer between 400 and 700) is defined 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 defined as light reflectance R2(x), and the light reflectance is expressed by the following formula: Difference in light reflectance between the first and second surfaces (%) = R1(x) - R2(x) This means that when the difference in light reflectance is calculated for each wavelength, the maximum value among the absolute values ​​of all "differences in light reflectance between the first surface and the second surface" (sometimes referred to in this specification as "|difference in light reflectance between the first surface and the second surface|max") is less than 1.5%. In addition, the protective film-forming film having a single overall color tone means that not only the entire area of ​​both sides of the protective film-forming film, but also the entire interior area has a single color tone (has the same color tone).

[0093] The color tone of the protective film-forming film can be adjusted, for example, by adjusting the type and content of the components contained in the protective film-forming film. In particular, the color tone of the protective film-forming film can be more easily adjusted by adjusting the type and content of the colorant (I) contained in the protective film-forming film.

[0094] The protective film-forming film may be made of one layer (single layer) or may be made of two or more layers. When the protective film-forming film is made 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.

[0095] In this specification, not only in the case of protective film-forming films, "multiple layers may be the same or different from each other" means "all layers may be the same, all layers may be different, or only some layers may be the same", and further, "multiple layers are different from each other" means "at least one of the constituent materials and thicknesses of each layer is different from each other".

[0096] When the protective film-forming film is composed of two or more layers, the adhesion between the layers may be poor, or the protective film may warp due to differences in the ease of expansion and contraction of the layers, and the protective film may peel off from the back surface of the chip. Furthermore, stacking multiple layers may increase the number of steps required to manufacture the protective film-forming film, making the manufacturing process more complicated. Furthermore, the increase in the number of steps tends to increase the manufacturing cost of the protective film-forming film. In terms of suppressing these defects, the protective film-forming film is preferably composed of one layer. Note that when the protective film-forming film is composed of one layer (single layer), the |difference in light reflectance between the first surface and the second surface|max is usually less than 1.5%, and the color tones of both surfaces of the protective film-forming film are uniform.

[0097] The thickness of the protective film-forming film is preferably less than 50 μm, more preferably 45 μm or less, and may be, for example, 40 μm or less or 35 μm or less. By making the thickness of the protective film-forming film equal to or less than the upper limit, various devices having a protective film-attached workpiece mounted thereon, such as the above-mentioned light-emitting device, can be easily thinned. On the other hand, the lower limit of the thickness of the protective film-forming film is not particularly limited. For example, it is preferably 10 μm or more in terms of increasing the strength of the protective film. In one embodiment, the thickness of the protective film-forming film may be, for example, any one of 10 μm or more and less than 50 μm, 10 to 45 μm, 10 to 40 μm, and 10 to 35 μm, although these are only examples of the thickness of the protective film-forming film. Here, "thickness of the protective film-forming film" means the thickness of the entire protective film-forming film, for example, the thickness of a protective film-forming film consisting of multiple layers means the total thickness of all layers that constitute the protective film-forming film.

[0098] <<Composition for forming protective film>> The protective film-forming film can be formed using a composition for forming a protective film (more specifically, a thermosetting composition for forming a protective film) containing its constituent materials. For example, the protective film-forming film can be formed by applying the composition for forming a protective film to the surface to be formed and drying it as necessary. The ratio of the contents of the components that do not vaporize at room temperature in the composition for forming a protective film is usually the same as the ratio of the contents of the components in the protective film-forming film. In this specification, "room temperature" means a temperature that is neither particularly cooled nor heated, that is, an ordinary temperature, and examples thereof include temperatures of 15 to 25°C.

[0099] The protective film-forming film may or may not have energy ray curing properties in addition to heat curing properties.

[0100] In this specification, the term "energy rays" refers to electromagnetic waves or charged particle beams having an energy quantum, examples of which include ultraviolet rays, radiation, and electron beams. Ultraviolet rays can be irradiated, for example, by using a high-pressure mercury lamp, a fusion lamp, a xenon lamp, a black light, an LED lamp, or the like as an ultraviolet ray source. Electron beams can be irradiated by generating them using an electron beam accelerator, or the like. In this specification, "energy ray curable" means a property that is cured by irradiation with energy rays, and "non-energy ray curable" means a property that is not cured even when irradiated with energy rays.

[0101] In the protective film-forming film, the ratio of the total content of one or more of the components contained in the protective film-forming film, which will be described later, to the total mass of the protective film-forming film does not exceed 100 mass %. Similarly, in the composition for forming a protective film, the ratio of the total content of one or more components contained in the composition for forming a protective film, as described below, to the total mass of the composition for forming a protective film does not exceed 100 mass %.

[0102] The protective film-forming composition may be applied by a known method, such as a method using various coaters such as an air knife coater, a blade coater, a bar coater, a gravure coater, a roll coater, a roll knife coater, a curtain coater, a die coater, a knife coater, a screen coater, a Mayer bar coater, or a kiss coater.

[0103] The drying conditions of the protective film-forming composition are not particularly limited. However, when the protective film-forming composition contains a solvent described later, it is preferable to heat-dry it. The protective film-forming composition containing the solvent is preferably heat-dried, for example, at 70 to 130°C for 10 seconds to 5 minutes. However, since the protective film-forming composition is thermosetting, it is preferable to heat-dry it so that the composition itself and the thermosetting protective film-forming film formed from the composition are not thermally cured.

[0104] Preferred protective film-forming films include, for example, those containing a polymer component (A), a thermosetting component (B), a filler (D) and a colorant (I), and also those containing a curing accelerator (C). The composition for forming a protective film will be described in detail below.

[0105] <Protective film forming composition (III)> A preferred example of the composition for forming a protective film includes a composition for forming a protective film (III) (sometimes simply referred to as "composition (III)" in this specification) containing a polymer component (A), a thermosetting component (B), a filler (D) and a colorant (I). The composition for forming a protective film (III) preferably further contains a curing accelerator (C).

[0106] [Polymer component (A)] The polymer component (A) is a polymer compound for imparting film-forming properties, flexibility, etc. to the protective film-forming film. In this specification, the polymer compound also includes products of polycondensation reactions.

[0107] The polymer component (A) contained in the composition (III) and the protective film-forming film may be one type or two or more types. When there are two or more types, the combination and ratio thereof can be selected arbitrarily.

[0108] Examples of the polymer component (A) include acrylic resins, urethane resins, phenoxy resins, silicone resins, and saturated polyester resins, with acrylic resins being preferred.

[0109] The acrylic resin in the polymer component (A) may be any known acrylic polymer. The weight average molecular weight (Mw) of the acrylic resin is preferably 10,000 to 2,000,000, and may be, for example, any one of 100,000 to 1,500,000, 150,000 to 1,200,000, and 200,000 to 1,000,000. When the weight average molecular weight of the acrylic resin is equal to or greater than the lower limit, it becomes easier to increase the storage modulus E' of the protective film (the test piece), such as the storage modulus E' (23). When the weight average molecular weight of the acrylic resin is equal to or less than the upper limit, the protective film-forming film becomes easier to follow the uneven surface of the adherend.

[0110] In this specification, unless otherwise specified, the "weight average molecular weight" is a polystyrene equivalent value measured by gel permeation chromatography (GPC).

[0111] The glass transition temperature (Tg) of the acrylic resin is preferably 0 to 70°C, and may be, for example, any of 0 to 50°C, 0 to 30°C, and 0 to 10°C. When the Tg of the acrylic resin is equal to or higher than the lower limit, it becomes easier to adjust the storage modulus E', such as the storage modulus E'(23) of the protective film (the test piece) to a desired value. In addition, the adhesion between the protective film and the support sheet described below is suppressed, and the peelability of the support sheet is appropriately improved. On the other hand, when the Tg of the acrylic resin is equal to or lower than the upper limit, the protective film-forming film becomes easier to follow the uneven surface of the adherend.

[0112] When the acrylic resin has two or more kinds of structural units, the glass transition temperature (Tg) of the acrylic resin can be calculated using the Fox formula. The Tg of the homopolymer of the monomer from which the structural unit is derived can be any value listed in the Polymer Data Handbook, the Adhesive Handbook, the Polymer Handbook, or the like.

[0113] Examples of the acrylic resin include polymers of one or more (meth)acrylic acid esters; copolymers of two or more monomers selected from the above-mentioned (meth)acrylic acid esters, (meth)acrylic acid, itaconic acid, vinyl acetate, acrylonitrile, styrene, and N-methylolacrylamide.

[0114] Examples of the (meth)acrylic acid ester constituting the acrylic resin include (meth)acrylic acid alkyl esters in which the alkyl group constituting the alkyl ester has a chain structure having 1 to 18 carbon atoms, such as methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, sec-butyl (meth)acrylate, tert-butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, and n-octyl (meth)acrylate; (meth)acrylic acid cycloalkyl esters such as isobornyl (meth)acrylate and dicyclopentanyl (meth)acrylate; (Meth)acrylic acid aralkyl esters such as benzyl (meth)acrylate; (Meth)acrylic acid cycloalkenyl esters such as (meth)acrylic acid dicyclopentenyl ester; (Meth)acrylic acid cycloalkenyloxyalkyl esters such as (meth)acrylic acid dicyclopentenyloxyethyl ester; (Meth)acrylic acid imide; glycidyl group-containing (meth)acrylic acid esters such as glycidyl (meth)acrylate; hydroxyl group-containing (meth)acrylic acid esters such as hydroxymethyl (meth)acrylate and 2-hydroxyethyl (meth)acrylate; Examples of the substituted amino group-containing (meth)acrylic acid ester include N-methylaminoethyl (meth)acrylate. Here, the term "substituted amino group" refers to a group having a structure in which one or two hydrogen atoms of an amino group are substituted with a group other than a hydrogen atom.

[0115] In this specification, the term "(meth)acrylic acid" is a concept that encompasses both "acrylic acid" and "methacrylic acid." The same applies to terms similar to (meth)acrylic acid.

[0116] The monomer constituting the acrylic resin may be of only one type, or may be of two or more types, and when it is of two or more types, the combination and ratio thereof can be selected arbitrarily.

[0117] The acrylic resin may or may not have a functional group capable of bonding with other compounds, such as a vinyl group, a (meth)acryloyl group, an amino group, a hydroxyl group, a carboxyl group, an isocyanate group, etc. The functional group of the acrylic resin may be bonded to other compounds via a crosslinking agent (F) described below, or may be bonded directly to other compounds without the crosslinking agent (F).

[0118] In the present invention, as the polymer component (A), a thermoplastic resin other than an acrylic resin (hereinafter sometimes simply abbreviated as "thermoplastic resin") may be used alone without using an acrylic resin, or may be used in combination with an acrylic resin. By using the thermoplastic resin, the peelability of the protective film from the support sheet may be improved, or the protective film-forming film may be easily adapted to the uneven surface of the adherend.

[0119] Examples of the thermoplastic resin include polyester, polyurethane, phenoxy resin, polybutene, polybutadiene, and polystyrene.

[0120] The thermoplastic resin contained in the composition (III) and the protective film-forming film may be one type or two or more types, and when there are two or more types, the combination and ratio thereof can be selected arbitrarily.

[0121] In composition (III), the ratio of the content of polymer component (A) to the total content of all components other than the solvent is preferably 10 to 85 mass% regardless of the type of polymer component (A), and may be, for example, any of 10 to 55 mass% and 10 to 25 mass%, any of 40 to 85 mass% and 70 to 85 mass%, or may be 40 to 55 mass%. This is equivalent to saying that, in the protective film-forming film, the content ratio of polymer component (A) relative to the total mass of the protective film-forming film is preferably 10 to 85 mass% regardless of the type of polymer component (A), and may be, for example, any of 10 to 55 mass% and 10 to 25 mass%, or any of 40 to 85 mass% and 70 to 85 mass%, or may be 40 to 55 mass%. This is based on the fact that the amount of components other than the solvent does not usually change during the process of removing the solvent from the resin composition containing the solvent and forming the resin film, and the content ratio of the components other than the solvent is the same between the resin composition and the resin film.Therefore, in this specification, not only in the case of the protective film-forming film, but also in the case of the resin film obtained by removing the solvent from the resin composition, the content of the components other than the solvent will be described hereafter.

[0122] The polymer component (A) may also correspond to the thermosetting component (B). In the present invention, when the composition (III) contains a component that corresponds to both the polymer component (A) and the thermosetting component (B), the composition (III) is considered to contain the polymer component (A) and the thermosetting component (B).

[0123] [Thermosetting component (B)] The thermosetting component (B) is a component for curing the protective film-forming film. The thermosetting component (B) contained in the composition (III) and the protective film-forming film may be one type or two or more types, and when there are two or more types, the combination and ratio thereof can be selected arbitrarily.

[0124] Examples of the thermosetting component (B) include epoxy-based thermosetting resins, thermosetting polyimide resins, and unsaturated polyester resins, with epoxy-based thermosetting resins being preferred. In this specification, the thermosetting polyimide resin is a general term for a polyimide precursor that forms a polyimide resin by thermal curing, and a thermosetting polyimide.

[0125] (Epoxy thermosetting resin) The epoxy thermosetting resin is made of, for example, an epoxy resin (B1) and a thermosetting agent (B2). The epoxy thermosetting resin may contain only the epoxy resin (B1) without containing the thermosetting agent (B2). The epoxy-based thermosetting resin contained in the composition (III) and the protective film-forming film may be one type or two or more types, and when there are two or more types, the combination and ratio thereof can be selected arbitrarily.

[0126] Epoxy resin (B1) The epoxy resin (B1) may be any known one, and examples thereof include bifunctional or higher functional epoxy compounds such as polyfunctional epoxy resins, biphenyl compounds, bisphenol A diglycidyl ether and hydrogenated products thereof, orthocresol novolac epoxy resins, dicyclopentadiene type epoxy resins, biphenyl type epoxy resins, bisphenol A type epoxy resins, bisphenol F type epoxy resins, and phenylene skeleton type epoxy resins.

[0127] As the epoxy resin (B1), an epoxy resin having an unsaturated hydrocarbon group may be used.

[0128] The number average molecular weight of the epoxy resin (B1) is not particularly limited, but is preferably 300 to 30,000 from the viewpoints of the curability of the protective film-forming film and the strength and heat resistance of the protective film. The epoxy equivalent of the epoxy resin (B1) is preferably from 100 to 1000 g / eq, and may be, for example, any one of from 100 to 600 g / eq and from 100 to 300 g / eq.

[0129] The epoxy resin (B1) may be used alone or in combination of two or more kinds. When two or more kinds are used in combination, the combination and ratio thereof can be selected arbitrarily.

[0130] ·Heat hardener (B2) The heat curing agent (B2) functions as a curing agent for the epoxy resin (B1). The thermosetting agent (B2) may be, for example, a compound having two or more functional groups capable of reacting with an epoxy group in one molecule. The functional group may, for example, be a phenolic hydroxyl group, an alcoholic hydroxyl group, an amino group, a carboxyl group, or an anhydride group of an acid group, and the like. The phenolic hydroxyl group, the amino group, or an anhydride group of an acid group is preferred, and the phenolic hydroxyl group or the amino group is more preferred.

[0131] Among the heat curing agents (B2), examples of phenolic curing agents having a phenolic hydroxyl group include polyfunctional phenolic resins, biphenols, novolac-type phenolic resins, dicyclopentadiene-type phenolic resins, and aralkyl-type phenolic resins. Among the heat curing agents (B2), examples of amine-based curing agents having an amino group include dicyandiamide.

[0132] The heat curing agent (B2) may have an unsaturated hydrocarbon group.

[0133] Of the thermosetting agents (B2), the number average molecular weight of resin components such as polyfunctional phenol resins, novolac type phenol resins, dicyclopentadiene type phenol resins, and aralkyl type phenol resins is preferably 300 to 30,000, and may be, for example, any one of 400 to 10,000 and 500 to 3,000. Of the thermosetting agent (B2), the molecular weight of the non-resin components, such as biphenol and dicyandiamide, is not particularly limited, but is preferably 60 to 500, for example.

[0134] The heat curing agent (B2) may be used alone or in combination of two or more kinds. When two or more kinds are used in combination, the combination and ratio thereof can be selected arbitrarily.

[0135] When the heat curing agent (B2) is used, the content of the heat curing agent (B2) in the composition (III) and the protective film-forming film is preferably 0.1 to 100 parts by mass relative to 100 parts by mass of the epoxy resin (B1), and may be, for example, any of 0.5 to 50 parts by mass, 0.5 to 25 parts by mass, 0.5 to 12 parts by mass, and 0.5 to 5 parts by mass. When the content of the heat curing agent (B2) is equal to or more than the lower limit, the curing of the protective film-forming film is more likely to proceed. When the content of the heat curing agent (B2) is equal to or less than the upper limit, the moisture absorption rate of the protective film-forming film is reduced, and the reliability of the package obtained using the protective film-forming film is further improved.

[0136] In the protective film-forming film, the content ratio of the thermosetting component (B) relative to the total mass of the protective film-forming film is preferably 5 to 40 mass%, and may be, for example, any one of 5 to 30 mass% and 5 to 20 mass%, or any one of 10 to 40 mass% and 13 to 40 mass%, or may be 10 to 30 mass%. When the ratio is in such a range, for example, the adhesion between the protective film and the support sheet described later is appropriately suppressed, and the peelability of the support sheet is improved. Here, when the thermosetting component (B) is an epoxy thermosetting resin, the "content of thermosetting component (B)" refers to the total content of the epoxy resin (B1) and the thermosetting agent (B2) when the thermosetting agent (B2) is used, and refers to the content of the epoxy resin (B1) when the thermosetting agent (B2) is not used.

[0137] [Filling material (D)] By containing the filler (D) in the protective film-forming film, the storage modulus E' of the protective film, such as the storage modulus E' (23), can be more easily adjusted. In addition, by containing the filler (D) in the protective film-forming film, the thermal expansion coefficient of the protective film-forming film and the protective film can be easily adjusted, and by optimizing this thermal expansion coefficient for the object on which the protective film is formed, the reliability of the workpiece with the protective film obtained using the protective film-forming film is further improved. In addition, by containing the filler (D) in the protective film-forming film, the moisture absorption rate of the protective film can be reduced and the heat dissipation can be improved.

[0138] The filler (D) may be either an organic filler or an inorganic filler, but is preferably an inorganic filler. Preferred inorganic fillers include, for example, powders of silica, alumina, talc, red iron oxide, silicon carbide, boron nitride, and the like; beads obtained by spheronizing these inorganic fillers; surface-modified products of these inorganic fillers; single crystal fibers of these inorganic fillers; glass fibers, and the like. Among these, the inorganic filler is preferably silica or alumina, and more preferably silica.

[0139] In terms of improving the dispersibility of the filler (D) in the composition for forming a protective film relative to other components, the silica is preferably silica that has been surface-modified with an organic group (organic compound), more preferably silica that has been surface-modified with a vinyl group, an epoxy group, a phenyl group or a methacryl group, and particularly preferably silica that has been surface-modified with a vinyl group or an epoxy group.

[0140] In order to improve the dispersibility of the filler (D) in the other components in the composition for forming a protective film, the average particle size of the filler (D) is preferably 0.02 to 2 μm, more preferably 0.05 to 1 μm, and particularly preferably 0.07 to 0.7 μm.

[0141] In this specification, not only in the case of the filler (D), the "average particle size" means, unless otherwise specified, the arithmetic mean value ([total particle size of 100 particles in plan view] / 100) of particle sizes calculated by observing particles as the object using an electron microscope, randomly selecting 100 particles, and calculating their particle size in plan view. In this case, the maximum value of the line segment obtained by connecting any two points on the outer circumference of the particle in plan view can be used as the particle size. For example, for particles in a resin film, such as filler (D) in a protective film-forming film, the resin film is baked to remove the resin components, and then the average particle diameter of the remaining particles can be determined by the above-mentioned method.

[0142] The filler (D) contained in the composition (III) and the protective film-forming film may be one type or two or more types, and when there are two or more types, the combination and ratio thereof can be selected arbitrarily.

[0143] In the protective film-forming film, the content ratio of the filler (D) relative to the total mass of the protective film-forming film is preferably 20 to 70 mass%, and may be, for example, any of 35 to 70 mass% and 50 to 70 mass%, or any of 20 to 60 mass% and 20 to 50 mass%, or may be 35 to 60 mass%. When the ratio is in such a range, it becomes easier to adjust the storage modulus E' of the protective film, such as the storage modulus E'(23) described above.

[0144] [Colorant (I)] The light reflectance of the protective film-forming film and protective film containing the colorant (I) can be easily adjusted.

[0145] Examples of the colorant (I) include known colorants such as inorganic pigments, organic pigments, and organic dyes.

[0146] Examples of the organic pigments and organic dyes include aminium-based dyes, cyanine-based dyes, merocyanine-based dyes, croconium-based dyes, squalium-based dyes, azulenium-based dyes, polymethine-based dyes, naphthoquinone-based dyes, pyrylium-based dyes, phthalocyanine-based dyes, naphthalocyanine-based dyes, naphtholactam-based dyes, azo-based dyes, condensed azo-based dyes, indigo-based dyes, perinone-based dyes, perylene-based dyes, dioxazine-based dyes, quinacridone-based dyes, isoindolinone-based dyes, quinophthalone-based dyes, pyrrole-based dyes, thioindigo-based dyes, metal complex-based dyes (metal complex dyes), dithiol metal complex-based dyes, indolephenol-based dyes, triarylmethane-based dyes, anthraquinone-based dyes, naphthol-based dyes, azomethine-based dyes, benzimidazolone-based dyes, pyranthrone-based dyes, and threne-based dyes.

[0147] Examples of the inorganic pigments include carbon black, cobalt-based pigments, iron-based pigments, chromium-based pigments, titanium-based pigments, vanadium-based pigments, zirconium-based pigments, molybdenum-based pigments, ruthenium-based pigments, platinum-based pigments, ITO (indium tin oxide)-based pigments, and ATO (antimony tin oxide)-based pigments.

[0148] The colorant (I) contained in the composition (III) and the protective film-forming film may be one type or two or more types. When there are two or more types, the combination and ratio thereof can be selected arbitrarily.

[0149] It is preferable that the colorant (I) is a white pigment, that is, the protective film-forming film contains a white pigment. As described above, when the protective film-forming film contains a white pigment, the light reflectance of the protective film after and before heating can be more easily increased.

[0150] 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 oxide, zinc sulfide, talc, clay, kaolin, titanium phosphate, mica, gypsum, white carbon, diatomaceous earth, bentonite, lithopone, zeolite, sericite, and hydrated halloysite. Among these, the white pigment is more preferably titanium oxide.

[0151] When the colorant (I) is a white pigment, from the viewpoint of improving the dispersibility of the colorant (I) in the other components in the composition for forming a protective film and from the viewpoint of increasing the light reflectance of the protective film after and before heating, the average particle size of the white pigment is preferably 0.05 to 2 μm, more preferably 0.1 to 1 μm, and even more preferably 0.2 to 0.7 μm. In order to improve the dispersibility of the colorant (I) in other components, the surface of the colorant (I) may be surface-treated with a surface treatment agent such as an inorganic compound having a hydroxyl group or an organic compound having a hydroxyl group or a carboxyl group. In such a surface-treated colorant (I), the portion derived from the surface treatment agent is considered to be part of the particle, and the particle size of the colorant (I) including the portion derived from the surface treatment agent is specified, and the average particle size of the colorant (I) is calculated based on the particle size.

[0152] When the colorant (I) is a white pigment, the content ratio of the white pigment in the protective film-forming film relative to the total mass of the protective film-forming film is preferably 0.1 to 15 mass%, and may be, for example, any one of 0.1 to 10 mass% and 0.1 to 5 mass%, or any one of 3 to 15 mass% and 4 to 15 mass%, or may be 3 to 10 mass%. When the ratio is equal to or more than the lower limit, the effect of using the white pigment, that is, the effect of increasing the light reflectance of the protective film after and before heating, becomes higher. When the ratio is equal to or less than the upper limit, excessive use of the white pigment is suppressed.

[0153] When the colorant (I) is a colorant other than a white pigment, the content ratio of the colorant other than a white pigment in the protective film-forming film relative to the total mass of the protective film-forming film may be, for example, any one of 0.01 to 5 mass%, 0.01 to 1 mass%, and 0.01 to 0.1 mass%. When the ratio is equal to or more than the lower limit, the protective film-forming film and the protective film can be appropriately colored. When the ratio is equal to or less than the upper limit, the light reflectance of the protective film after and before heating can be more easily increased.

[0154] When the composition (III) and the protective film-forming film contain at least a white pigment as the colorant (I), the ratio of the content of the white pigment to the total content of the colorant (I) (the total content of the white pigment and the colorant other than the white pigment) in the composition (III) and the protective film-forming film is preferably 70 to 100 mass%, more preferably 80 to 100 mass%, even more preferably 90 to 100 mass%, and particularly preferably 95 to 100 mass%. When the ratio is equal to or more than the lower limit, the effect of using the white pigment is further increased.

[0155] [Cure accelerator (C)] The curing accelerator (C) is a component for adjusting the curing speed of the protective film-forming film. Furthermore, by using the curing accelerator (C), the storage modulus E' of the protective film, such as the storage modulus E'(23), can be easily increased.

[0156] The curing accelerator (C) is preferably a curing accelerator other than the imidazole curing accelerator. Examples of such a preferable curing accelerator (C) include the thermal base generators and other curing accelerators that do not fall into either the thermal base generators or the imidazole curing accelerators.

[0157] The thermal base generator has been described above, and detailed description thereof will be omitted here. Examples of the other curing accelerators include tertiary amines such as triethylenediamine, benzyldimethylamine, triethanolamine, dimethylaminoethanol, and tris(dimethylaminomethyl)phenol; and organic phosphines (phosphines in which one or more hydrogen atoms are substituted with an organic group) such as tributylphosphine, diphenylphosphine, and triphenylphosphine.

[0158] The curing accelerator (C) contained in the composition (III) and the protective film-forming film may be one type or two or more types. When there are two or more types, the combination and ratio thereof can be selected arbitrarily.

[0159] However, when the composition (III) and the protective film-forming film contain a curing accelerator (C), it is preferable that the curing accelerator (C) contains at least the thermal base generator, and it is particularly preferable that the curing accelerator (C) contains only the thermal base generator.

[0160] When the curing accelerator (C) is used, the content of the curing accelerator (C) in the composition (III) and the protective film-forming film is preferably 1 to 15 parts by mass relative to 100 parts by mass of the content of the thermosetting component (B), and may be, for example, 1 to 10 parts by mass, 1 to 5 parts by mass, 5 to 15 parts by mass, 10 to 15 parts by mass, or 5 to 10 parts by mass. When the content of the curing accelerator (C) is equal to or more than the lower limit, the effect of using the curing accelerator (C) is more remarkable. When the content of the curing accelerator (C) is equal to or less than the upper limit, for example, the effect of suppressing the highly polar curing accelerator (C) from migrating to the adhesive interface side with the adherend and segregating in the protective film-forming film under high temperature and high humidity conditions is enhanced. As a result, the reliability of the workpiece with the protective film obtained using the protective film-forming film is further improved.

[0161] When the composition (III) and the protective film-forming film contain at least the thermal base generator as the curing accelerator (C), the ratio of the content of the thermal base generator to the total content of the curing accelerator (C) in the composition (III) and the protective film-forming film is preferably 70 to 100 mass%, more preferably 80 to 100 mass%, even more preferably 90 to 100 mass%, and particularly preferably 95 to 100 mass%. When the ratio is equal to or greater than the lower limit, the storage modulus E' of the protective film, such as the storage modulus E'(23), can be easily increased, and the effect of suppressing the decrease in the light reflectance of the heated protective film is further increased.

[0162] [Coupling agent (E)] The composition (III) and the protective film-forming film may contain a coupling agent (E). By using a coupling agent (E) having a functional group capable of reacting with an inorganic compound or an organic compound, the adhesiveness of the protective film to the adherend can be improved. In addition, by using the coupling agent (E), the water resistance of the protective film is improved without impairing its heat resistance.

[0163] The coupling agent (E) is preferably a compound having a functional group capable of reacting with the functional groups of the polymer component (A), the thermosetting component (B), etc., and is more preferably a silane coupling agent.

[0164] Preferred examples of the silane coupling agent include 3-glycidyloxypropyltrimethoxysilane, 3-glycidyloxypropylmethyldiethoxysilane, 3-glycidyloxypropyltriethoxysilane, 3-glycidyloxymethyldiethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-(2-aminoethylamino)propyltrimethoxysilane, 3-(2- Examples of the silane include bis(3-(aminoethylamino)propylmethyldiethoxysilane, 3-(phenylamino)propyltrimethoxysilane, 3-anilinopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, bis(3-triethoxysilylpropyl)tetrasulfane, methyltrimethoxysilane, methyltriethoxysilane, vinyltrimethoxysilane, vinyltriacetoxysilane, and imidazole silane.

[0165] The coupling agent (E) contained in the composition (III) and the protective film-forming film may be one type or two or more types, and when there are two or more types, the combination and ratio thereof can be selected arbitrarily.

[0166] When the coupling agent (E) is used, the content of the coupling agent (E) in the composition (III) and the protective film-forming film is preferably 0.03 to 10 parts by mass relative to 100 parts by mass of the total content of the polymer component (A) and the thermosetting component (B), and may be, for example, any of 0.03 to 5 parts by mass, 0.03 to 2 parts by mass, and 0.03 to 0.5 parts by mass. When the content of the coupling agent (E) is equal to or greater than the lower limit, the effects of using the coupling agent (E), such as improved dispersibility of the filler (D) in the resin and improved adhesion of the protective film to the adherend, are more significantly obtained. When the content of the coupling agent (E) is equal to or less than the upper limit, the generation of outgassing is more suppressed.

[0167] [Crosslinker (F)] When the polymer component (A) is the above-mentioned acrylic resin or the like and has a functional group capable of bonding with other compounds, such as a vinyl group, a (meth)acryloyl group, an amino group, a hydroxyl group, a carboxyl group, an isocyanate group, or the like, the composition (III) and the protective film-forming film may contain a crosslinking agent (F). The crosslinking agent (F) is a component for bonding the functional group in the polymer component (A) with other compounds to crosslink the functional group, and by crosslinking in this manner, the adhesive strength and cohesive strength of the protective film-forming film can be adjusted.

[0168] Examples of the crosslinking agent (F) include organic polyvalent isocyanate compounds, organic polyvalent imine compounds, metal chelate crosslinking agents (crosslinking agents having a metal chelate structure), and aziridine crosslinking agents (crosslinking agents having an aziridinyl group).

[0169] The crosslinking agent (F) contained in the composition (III) and the protective film-forming film may be one type or two or more types, and when there are two or more types, the combination and ratio thereof can be selected arbitrarily.

[0170] When the crosslinking agent (F) is used, the content of the crosslinking agent (F) in the composition (III) is preferably 0.01 to 20 parts by mass per 100 parts by mass of the polymer component (A). When the content of the crosslinking agent (F) is equal to or more than the lower limit, the effect of using the crosslinking agent (F) is more remarkable. When the content of the crosslinking agent (F) is equal to or less than the upper limit, excessive use of the crosslinking agent (F) is suppressed.

[0171] [Energy ray curable resin (G)] The composition (III) and the protective film-forming film may contain an energy ray curable resin (G). By containing the energy ray curable resin (G), the protective film-forming film can change its properties by irradiation with energy rays.

[0172] The energy ray curable resin (G) is an energy ray curable compound, or an oligomer or polymer having energy ray curability that can be regarded as having been synthesized from an energy ray curable compound. The energy ray-curable compound includes, for example, a compound having at least one polymerizable double bond in the molecule, and is preferably an acrylate-based compound having a (meth)acryloyl group.

[0173] The energy ray curable resin (G) contained in the composition (III) and the protective film-forming film may be one type or two or more types. When there are two or more types, the combination and ratio thereof can be selected arbitrarily.

[0174] When the energy ray curable resin (G) is used, the content of the energy ray curable resin (G) in the composition (III) is preferably 1 to 30 mass % relative to the total mass of the composition (III).

[0175] [Photopolymerization initiator (H)] When the composition (III) and the protective film-forming film contain an energy ray curable resin (G), they may contain a photopolymerization initiator (H) in order to efficiently advance the polymerization reaction of the energy ray curable resin (G).

[0176] The photopolymerization initiator (H) contained in the composition (III) and the protective film-forming film may be one type or two or more types, and when there are two or more types, the combination and ratio thereof can be selected arbitrarily.

[0177] When the photopolymerization initiator (H) is used, the content of the photopolymerization initiator (H) in the composition (III) is preferably 0.1 to 20 parts by mass per 100 parts by mass of the energy ray-curable resin (G).

[0178] [General Purpose Additives (J)] The composition (III) and the protective film-forming film may contain a general-purpose additive (J) within the range that does not impair the effects of the present invention. The general-purpose additive (J) may be a known one and may be arbitrarily selected depending on the purpose, and is not particularly limited. Preferred examples thereof include plasticizers, antistatic agents, antioxidants, gettering agents, and ultraviolet absorbers.

[0179] The general-purpose additive (J) contained in the composition (III) and the protective film-forming film may be one type or two or more types, and when there are two or more types, the combination and ratio thereof can be selected arbitrarily. The content of the composition (III) and the general-purpose additive (J) in the protective film-forming film is not particularly limited and may be appropriately selected depending on the purpose.

[0180] [solvent] It is preferable that the composition (III) further contains a solvent. The composition (III) containing a solvent has good handleability. In this specification, unless otherwise specified, the term "solvent" is used as a concept that includes not only a substance that dissolves a target component, but also a dispersion medium that disperses the target component.

[0181] The solvent is not particularly limited, but preferred examples include hydrocarbons such as toluene and xylene; alcohols such as methanol, ethanol, 2-propanol, isobutyl alcohol (2-methylpropan-1-ol), and 1-butanol; esters such as ethyl acetate; ketones such as acetone and methyl ethyl ketone; ethers such as tetrahydrofuran; and amides (compounds having an amide bond) such as dimethylformamide and N-methylpyrrolidone. The solvent contained in the composition (III) may be only one type, or may be two or more types. When two or more types are contained, the combination and ratio thereof can be selected arbitrarily.

[0182] The content of the solvent in the composition (III) is not particularly limited, and may be appropriately selected depending on, for example, the types of components other than the solvent.

[0183] <Method for producing protective film-forming composition (III)> Composition (III) can be produced by blending the respective components constituting composition (III). The order of addition of the components when blending is not particularly limited, and two or more components may be added simultaneously. The method for mixing the components during blending is not particularly limited, and may be appropriately selected from known methods such as a method of mixing by rotating a stirrer or stirring blade, a method of mixing using a mixer, a method of mixing by adding ultrasound, etc. The temperature and time during addition and mixing of each component are not particularly limited as long as the components do not deteriorate, and may be adjusted appropriately. A temperature of 15 to 30°C is preferred.

[0184] ◎Example of protective film (1) Fig. 1 is a cross-sectional view showing an example of a protective film-forming film according to an embodiment of the present invention. In addition, the drawings used in the following description may show the main parts in an enlarged manner for the sake of convenience in order to make the features of the present invention easier to understand, and the dimensional ratios of each component may not necessarily be the same as the actual ones.

[0185] The protective film-forming film 13 shown here is configured to have a first release film 151 on one of its surfaces (sometimes referred to as the "first surface" in this specification) 13a, and a second release film 152 on the other surface (sometimes referred to as the "second surface" in this specification) 13b opposite the first surface 13a. Such a protective film-forming film 13 is suitable for storage, for example, in a roll form.

[0186] When the protective film, which is a thermoset product of the protective film-forming film 13, is heated at 260° C. for 5 minutes and the light reflectance of the protective film after heating is measured, the light reflectance is 26% or more in the entire wavelength range of 400 to 700 nm. The protective film-forming film 13 can be formed using the above-mentioned protective film-forming composition.

[0187] Both the first release film 151 and the second release film 152 may be of known types. The first release film 151 and the second release film 152 may be the same as each other, or may be different from each other, for example, by requiring different peeling forces when peeling them off from the protective film-forming film 13. Both the first release film 151 and the second release film 152 are preferably release films in which a silicone-based release agent layer is formed (silicone-treated) on one side of a polyethylene terephthalate film.

[0188] 1, one of the first release film 151 and the second release film 152 is removed, and the resulting exposed surface becomes a surface to be attached to any part of the workpiece. Then, the remaining other of the first release film 151 and the second release film 152 is removed, and the resulting exposed surface becomes a surface to be attached to a support sheet or a processing sheet, which will be described later.

[0189] Figure 1 shows an example in which a release film is provided on both sides (first side 13a and second side 13b) of the protective film-forming film 13, but the release film may be provided on only one side of the protective film-forming film 13, i.e., only the first side 13a or only the second side 13b.

[0190] The protective film-forming film of this embodiment can be attached to any part of the work (when the work is a semiconductor wafer, to the back surface of the semiconductor wafer) without using a support sheet described later. In this case, a release film may be provided on the surface of the protective film-forming film opposite to the surface attached to the work, and this release film may be removed at an appropriate timing.

[0191] On the other hand, the protective film-forming film of the present embodiment can be used in combination with a support sheet described later to form a composite sheet for forming a protective film, which allows both the formation of a protective film and dicing to be performed. Such a composite sheet for forming a protective film will be described later.

[0192] ◎Example of protective film (2) An example of a preferred protective film-forming film of the present embodiment is a thermosetting protective film-forming film, When the protective film, which is a thermosetting product of the protective film-forming film, is heated at 260° C. for 5 minutes and the light reflectance of the protective film after heating is measured, the light reflectance is 26% or more in the entire wavelength range of 400 to 700 nm, The protective film-forming film contains a polymer component (A), an epoxy resin (B1), a heat curing agent (B2), a filler (D) and a white pigment, and may further contain a curing accelerator (C), The protective film-forming film may include a film in which the curing accelerator (C) is a curing accelerator other than an imidazole-based curing accelerator.

[0193] An example of a more preferable protective film-forming film of the present embodiment is a thermosetting protective film-forming film, When the protective film, which is a thermosetting product of the protective film-forming film, is heated at 260° C. for 5 minutes and the light reflectance of the protective film after heating is measured, the light reflectance is 26% or more in the entire wavelength range of 400 to 700 nm, The protective film-forming film contains a polymer component (A), an epoxy resin (B1), a heat curing agent (B2), a filler (D) and a white pigment, and may further contain a curing accelerator (C), The curing accelerator (C) is a curing accelerator other than an imidazole curing accelerator, In the protective film-forming film, the ratio of the total content of the epoxy resin (B1) and the thermosetting agent (B2) to the total mass of the protective film-forming film is 5 to 40 mass%, In the protective film-forming film, the content ratio of the filler (D) to the total mass of the protective film-forming film is 20 to 70 mass%, In the protective film-forming film, the content ratio of the white pigment to the total mass of the protective film-forming film is 0.1 to 15 mass%, When the protective film-forming film contains the curing accelerator (C), the content of the curing accelerator (C) in the protective film-forming film is 1 to 15 parts by mass with respect to 100 parts by mass of the total content of the epoxy resin (B1) and the heat curing agent (B2), However, in the protective film-forming film, the ratio of the total content of the polymer component (A), the epoxy resin (B1), the heat curing agent (B2), the filler (D), the white pigment and the curing accelerator (C) to the total mass of the protective film-forming film does not exceed 100 mass%. Such a protective film-forming film contains at least a thermal base generator as the curing accelerator (C), and in the protective film-forming film, the ratio of the content of the thermal base generator to the total content of the curing accelerator (C) is preferably 70 to 100 mass%.

[0194] ◇Composite sheet for forming protective film The composite sheet for forming a protective film comprises a support sheet and a protective film-forming film provided on one side of the support sheet, and the protective film-forming film is the protective film-forming film according to one embodiment of the present invention described above.

[0195] In this specification, the laminated structure of the support sheet and the protective film after the protective film-forming film has cured to become a protective film may be referred to as a "cured composite sheet for forming a protective film."

[0196] Each layer constituting the composite sheet for forming a protective film will be described in detail below.

[0197] ◎ Support sheet The support sheet may be one layer (single layer) or two or more layers. When the support sheet is made of multiple layers, the constituent materials and thicknesses of the multiple layers may be the same or different, and the combination of the multiple layers is not particularly limited as long as it does not impair the effects of the present invention.

[0198] The support sheet may be transparent or opaque, and may be colored depending on the purpose. For example, when the protective film-forming film has energy ray curing properties, the support sheet is preferably one that transmits energy rays.

[0199] Examples of the support sheet include a sheet having a substrate and a pressure-sensitive adhesive layer provided on one surface of the substrate, a sheet consisting of only a substrate, etc. When the support sheet has a pressure-sensitive adhesive layer, the pressure-sensitive adhesive layer is disposed between the substrate and the protective film-forming film in the composite sheet for forming a protective film.

[0200] When a support sheet having a substrate and a pressure-sensitive adhesive layer is used, the adhesion and peelability between the support sheet and the protective film-forming film in the composite sheet for forming a protective film can be easily adjusted. When a support sheet consisting of only a substrate is used, the composite sheet for forming a protective film can be produced at low cost.

[0201] ◎Example of a composite sheet for forming a protective film FIG. 2 is a cross-sectional view that illustrates an example of a composite sheet for forming a protective film, which includes a protective film-forming film according to one embodiment of the present invention. In FIG. 2 and subsequent figures, the same components as those shown in the figures already described are given the same reference numerals as in the figures already described, and detailed description thereof will be omitted.

[0202] The composite sheet 101 for forming a protective film shown here is composed of a support sheet 10 and a protective film forming film 13 provided on one side 10a (sometimes referred to as the "first side" in this specification) of the support sheet 10. The support sheet 10 is configured to include a base material 11 and an adhesive layer 12 provided on one surface 11a of the base material 11. In the composite sheet 101 for forming a protective film, the adhesive layer 12 is disposed between the base material 11 and a protective film-forming film 13. That is, the composite sheet 101 for forming a protective film is configured by laminating a substrate 11, a pressure-sensitive adhesive layer 12, and a protective film-forming film 13 in this order in the thickness direction. The first surface 10a of the support sheet 10 is the same as the surface 12a of the pressure-sensitive adhesive layer 12 opposite the substrate 11 side (sometimes referred to as the "first surface" in this specification).

[0203] The composite sheet 101 for forming a protective film further includes a jig adhesive layer 16 and a release film 15 on the protective film-forming film 13 . In the composite sheet 101 for forming a protective film, a protective film-forming film 13 is laminated over the entire or almost entire surface of the first surface 12a of the pressure-sensitive adhesive layer 12, and a jig adhesive layer 16 is laminated over a portion of the surface 13a of the protective film-forming film 13 opposite the pressure-sensitive adhesive layer 12 side (sometimes referred to as the "first surface" in this specification), i.e., a region near the periphery. Furthermore, a release film 15 is laminated over the region of the first surface 13a of the protective film-forming film 13 where the jig adhesive layer 16 is not laminated, and over the surface 16a of the jig adhesive layer 16 opposite the protective film-forming film 13 side (sometimes referred to as the "first surface" in this specification).

[0204] Not only in the case of the composite sheet 101 for forming a protective film, but also in the composite sheet for forming a protective film of this embodiment, the release film is of an optional configuration, and the composite sheet for forming a protective film of this embodiment may or may not have a release film.

[0205] The jig adhesive layer 16 is used to fix the composite sheet for forming a protective film 101 to a jig such as a ring frame. The jig adhesive layer 16 may have, for example, a single-layer structure containing an adhesive component, or a multi-layer structure in which layers containing adhesive components are laminated on both sides of a core sheet.

[0206] The protective film-forming film 13 is the protective film-forming film shown in FIG. 1 according to one embodiment of the present invention described above.

[0207] In the protective film-forming composite sheet 101, with the release film 15 removed, any part of the work is attached to the first surface 13a of the protective film-forming film 13, and the first surface 16a of the jig adhesive layer 16 is attached to a jig such as a ring frame, for use. When the work is a semiconductor wafer, the back surface of the semiconductor wafer is attached to the first surface 13a of the protective film-forming film 13.

[0208] The composite sheet for forming a protective film of this embodiment is not limited to that shown in Figure 2, and may be one in which some of the configurations shown in Figure 2 have been changed or deleted, or other configurations have been added to those described above, within the scope that does not impair the effects of the present invention. For example, the composite sheet for forming a protective film of this embodiment may be a composite sheet for forming a protective film 101 shown in Figure 2, in which the size of the protective film-forming film 13 in a direction parallel to its first surface 13a is adjusted to be equal to or slightly larger than the size of the workpiece to which the protective film-forming film 13 is to be attached. For example, the composite sheet for forming a protective film of this embodiment may be the composite sheet for forming a protective film 101 shown in FIG. 2 in which the jig adhesive layer 16 is not provided. For example, the composite sheet for forming a protective film of the present embodiment may be a composite sheet for forming a protective film 101 shown in Fig. 2, in which the support sheet 10 is composed only of a substrate. In this case, it is preferable that at least the surface of the substrate 11 on the side of the protective film-forming film 13 is adhesive.

[0209] Next, each layer constituting the support sheet will be described in more detail.

[0210] ○Base material The substrate is in the form of a sheet or film, and examples of the constituent materials thereof include various resins. Examples of the resin include polyethylene; polyolefins other than polyethylene, such as polypropylene; ethylene-based copolymers (copolymers obtained using ethylene as a monomer), such as ethylene-vinyl acetate copolymer; vinyl chloride-based resins (resins obtained using vinyl chloride as a monomer), such as polyvinyl chloride; polystyrene; polycycloolefins; polyesters, such as polyethylene terephthalate; poly(meth)acrylic acid esters; polyurethanes; polyurethane acrylates; polyimides; polyamides; polycarbonates; fluororesins; polyacetals; modified polyphenylene oxides; polyphenylene sulfides; polysulfones; polyether ketones, and the like. The resin may be, for example, a polymer alloy such as a mixture of the polyester with another resin. Examples of the resin include crosslinked resins in which one or more of the resins exemplified above are crosslinked; and modified resins such as ionomers using one or more of the resins exemplified above.

[0211] The resin constituting the substrate may be of only one type, or of two or more types. When two or more types are used, the combination and ratio thereof can be selected arbitrarily.

[0212] The substrate may consist of one layer (single layer), or may consist of two or more layers. When the substrate consists of multiple layers, the multiple layers may be the same or different, and the combination of the multiple layers is not particularly limited.

[0213] The thickness of the substrate is preferably 50 to 300 μm, and may be, for example, 60 to 100 μm. When the thickness of the substrate is in such a range, the flexibility of the composite sheet for forming a protective film and the suitability for attachment to a work are further improved. Here, the "thickness of the substrate" means the thickness of the entire substrate. For example, the thickness of a substrate consisting of multiple layers means the total thickness of all layers constituting the substrate.

[0214] The substrate may contain, in addition to the main constituent materials such as the resin, various known additives such as fillers, colorants, antioxidants, organic lubricants, catalysts, softeners (plasticizers), and the like.

[0215] The substrate may be transparent or opaque, may be colored according to the purpose, and may have other layers vapor-deposited thereon.

[0216] In order to adjust the adhesion to a layer (for example, a pressure-sensitive adhesive layer, a protective film-forming film, or the other layer) provided thereon, the surface of the substrate may be subjected to roughening treatment such as sandblasting or solvent treatment, oxidation treatment such as corona discharge treatment, electron beam irradiation treatment, plasma treatment, ozone / ultraviolet radiation treatment, flame treatment, chromic acid treatment, or hot air treatment, lipophilic treatment, hydrophilic treatment, etc. The surface of the substrate may be treated with a primer.

[0217] The substrate may have adhesiveness on at least one surface thereof by containing a specific range of components (for example, a resin, etc.).

[0218] 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.

[0219] Adhesive layer The pressure-sensitive adhesive layer is in the form of a sheet or film and contains a pressure-sensitive adhesive. Examples of the adhesive include adhesive resins such as acrylic resins, urethane resins, rubber-based resins, silicone resins, epoxy-based resins, polyvinyl ethers, polycarbonates, and ester-based resins.

[0220] The adhesive layer may consist of one layer (single layer), or may consist of two or more layers. If it consists of multiple layers, these multiple layers may be the same or different, and the combination of these multiple layers is not particularly limited.

[0221] The thickness of the pressure-sensitive adhesive layer is not particularly limited, but is preferably from 1 to 100 μm, and may be, for example, any one of from 1 to 60 μm and 1 to 30 μm. Here, "the thickness of the adhesive layer" means the thickness of the entire adhesive layer, and for example, the thickness of an adhesive layer consisting of multiple layers means the total thickness of all layers that make up the adhesive layer.

[0222] The pressure-sensitive adhesive layer may be either energy ray-curable or non-energy ray-curable. The energy ray-curable pressure-sensitive adhesive layer can adjust the physical properties before and after curing.

[0223] The adhesive layer can be formed using an adhesive composition containing an adhesive. For example, the adhesive composition is applied to the surface on which the adhesive layer is to be formed, and then dried as necessary to form the adhesive layer at the desired location. The ratio of the contents of the components that do not vaporize at room temperature in the adhesive composition is usually the same as the ratio of the contents of the components in the adhesive layer.

[0224] The pressure-sensitive adhesive composition can be applied and dried, for example, by the same method as in the application and drying of the above-mentioned composition for forming a protective film.

[0225] The pressure-sensitive adhesive composition can be obtained by blending the pressure-sensitive adhesive and, if necessary, components other than the pressure-sensitive adhesive, which are components for constituting the pressure-sensitive adhesive composition. The pressure-sensitive adhesive composition can be produced in the same manner as in the case of the composition for forming a protective film described above, except that the types of ingredients used are different.

[0226] ◇Manufacturing method of composite sheet for forming protective film The composite sheet for forming a protective film can be produced by laminating the above-mentioned layers so as to have a corresponding positional relationship, and adjusting the shape of some or all of the layers as necessary. The method for forming each layer is as described above.

[0227] For example, when a pressure-sensitive adhesive layer is laminated on a substrate during the production of a support sheet, the pressure-sensitive adhesive composition may be applied onto the substrate and dried as necessary. Alternatively, the pressure-sensitive adhesive layer can be laminated on the substrate by coating the pressure-sensitive adhesive composition on a release film, drying it as necessary to form a pressure-sensitive adhesive layer on the release film, and then laminating the exposed surface of the pressure-sensitive adhesive layer to one surface of the substrate. In this case, the pressure-sensitive adhesive composition is preferably coated on the release-treated surface of the release film. Up to this point, the case where the pressure-sensitive adhesive layer is laminated on the substrate has been given as an example, but the above-mentioned method can also be applied to, for example, the case where the protective film-forming film or the other layer is laminated on the substrate. When laminating the protective film-forming film on the substrate, the above-mentioned protective film-forming composition is applied on the substrate and dried as necessary, or the protective film-forming composition is applied on the release film and dried as necessary to form the protective film-forming film on the release film, and the exposed surface of this protective film-forming film is bonded to one surface of the substrate.

[0228] For example, when a protective film-forming film is laminated on top of an adhesive layer already laminated on a substrate, a protective film-forming film is first formed on a release film using a protective film-forming composition, and the exposed surface of this formed protective film-forming film opposite the side in contact with the release film is then bonded to the exposed surface (first surface) of the adhesive layer. Here, the case where a protective film-forming film is laminated on the pressure-sensitive adhesive layer has been taken as an example, but the same method can also be used when, for example, a layer other than the protective film-forming film is laminated on the pressure-sensitive adhesive layer.

[0229] ◇ Manufacturing method of substrate device (method of using protective film forming film) The protective film-forming film of this embodiment can be used to manufacture a workpiece with a protective film and a substrate device including the workpiece with a protective film.

[0230] A manufacturing method of a substrate device according to one embodiment of the present invention is a manufacturing method of a substrate device using a protective film-forming film or a composite sheet for forming a protective film, the protective film-forming film being the protective film-forming film according to the embodiment of the present invention described above, and the composite sheet for forming a protective film being configured to include a support sheet and the protective film-forming film provided on one side of the support sheet, and the manufacturing method includes a bonding step of bonding the protective film-forming film that does not constitute the composite sheet for forming a protective film, or the protective film in the composite sheet for forming a protective film, to a side (rear side) opposite to a side (circuit side) having a protruding electrode of a workpiece, a thermal curing step of thermally curing the protective film to form a protective film after the bonding step, and a processing sheet is attached to a side of the protective film-forming film or protective film opposite to the side of the workpiece, and the workpiece is processed on the processing sheet to produce a workpiece, and cutting the protective film-forming film or protective film, a workpiece with a protective film-forming film is produced by processing the work on the support sheet, and a workpiece with a protective film is produced by cutting the protective film-forming film or protective film, the workpiece being provided with the workpiece and the protective film after cutting provided on the surface of the workpiece opposite to the surface having the protruding electrode, or a workpiece with a protective film is produced by cutting the protective film-forming film or protective film, the workpiece being provided with the workpiece and the protective film after cutting provided on the surface of the workpiece opposite to the surface having the protruding electrode; a pick-up step, after the processing and cutting steps, of separating the workpiece with the protective film-forming film or the workpiece with the protective film from the processing sheet or support sheet and picking it up; and a mounting step, after the pick-up step and the heat-curing step, of bringing the protruding electrode in the workpiece with the protective film into contact with a circuit board, and then heating the workpiece with the protective film to melt the protruding electrode and connect it to the circuit board. According to the manufacturing method of the present embodiment, a workpiece with a protective film is manufactured using the protective film-forming film of the present embodiment, and a substrate device is manufactured including the workpiece with the protective film. In the process, even if the workpiece with the protective film is heated at a high temperature of about 260° C. in the mounting process, the light reflectance of the heated protective film is high, so that the design of the device is not impaired.

[0231] An example of a method for manufacturing a substrate device, i.e., a semiconductor device, when the work is a semiconductor wafer, is a method for manufacturing a semiconductor device including a semiconductor chip with a protective film using a protective film-forming film or a composite sheet for forming a protective film, the protective film-forming film being the protective film-forming film according to the embodiment of the present invention described above, the composite sheet for forming a protective film being configured to include a support sheet and the protective film-forming film provided on one surface of the support sheet, the manufacturing method including a bonding step of bonding the protective film-forming film not constituting the composite sheet for forming a protective film, or the protective film in the composite sheet for forming a protective film, to a surface (rear surface) of a semiconductor wafer opposite to a surface (circuit surface) having protruding electrodes, a thermal curing step of thermally curing the protective film to form a protective film after the bonding step, and a processing sheet being attached to a surface of the protective film-forming film or protective film opposite to the semiconductor wafer side when the protective film-forming film not constituting the composite sheet for forming a protective film is used, and the semiconductor wafer is processed on the processing sheet to produce a semiconductor chip, The protective film-forming film or protective film is cut, and in the case where the protective film-forming composite sheet is used, the semiconductor wafer is processed on the support sheet to produce a semiconductor chip, and the protective film-forming film or protective film is cut to produce a semiconductor chip with a protective film-forming film, the semiconductor chip and the protective film-forming film after cutting provided on the surface (back surface) opposite to the surface (circuit surface) of the semiconductor chip having the protruding electrodes, or the semiconductor chip and the protective film-forming film after cutting provided on the surface (back surface) opposite to the surface (circuit surface) of the semiconductor chip having the protruding electrodes a processing and cutting step of producing a semiconductor chip with a protective film, the semiconductor chip having the protective film after cutting, the protective film being provided on the processing sheet or the support sheet; a pick-up step of picking up the semiconductor chip with the protective film or the semiconductor chip with the protective film from the processing sheet or the support sheet after the processing and cutting step; and a mounting step of bringing the protruding electrodes in the semiconductor chip with the protective film into contact with a circuit board, and then heating the semiconductor chip with the protective film to melt the protruding electrodes and connect them to the circuit board after the pick-up step and the heat-curing step.The present invention relates to a method for manufacturing a semiconductor device including a semiconductor chip with a protective film,

[0232] When the workpiece is a semiconductor wafer, the order of processing the semiconductor wafer (dividing, individualizing) and cutting the protective film-forming film or protective film in the processing and cutting process can be selected arbitrarily depending on the purpose, and cutting may be performed after processing, or processing and cutting may be performed simultaneously, or cutting may be performed before processing. In this embodiment, when the processing of the semiconductor wafer and the cutting of the protective film-forming film or the protective film are performed continuously by the same operation without interruption, regardless of the order, the processing and cutting are considered to be performed simultaneously.

[0233] The processing of the semiconductor wafer (hereinafter sometimes simply referred to as "processing") and the cutting of the protective film-forming film or protective film (hereinafter sometimes simply referred to as "cutting") can both be carried out by known methods depending on the order in which they are performed.

[0234] When cutting is performed after processing, the semiconductor wafer can be processed by, for example, stealth dicing (registered trademark) or laser dicing. Stealth Dicing (registered trademark) is a method as follows. That is, first, a planned dividing point is set inside the semiconductor wafer, and a laser beam is irradiated so as to converge on this point, forming a modified layer inside the semiconductor wafer. The modified layer of the semiconductor wafer is different from other parts of the semiconductor wafer, and is altered by the irradiation of the laser beam, and has a weaker strength. Therefore, when a force is applied to the semiconductor wafer, a crack is generated in the modified layer inside the semiconductor wafer, which extends in the direction of both sides of the semiconductor wafer, and becomes the starting point for dividing (processing) the semiconductor wafer. Next, a force is applied to the semiconductor wafer to divide the semiconductor wafer at the site of the modified layer, and semiconductor chips are produced.

[0235] When cutting is performed after processing, the protective film-forming film or protective film can be cut by, for example, pulling the protective film-forming film or protective film in a direction parallel to the surface attached to the semiconductor chip, that is, by so-called expanding. The expanded protective film-forming film or protective film is cut along the outer periphery of the semiconductor chip. Such cutting by expanding is preferably performed at a low temperature such as -20 to 5°C.

[0236] When processing and cutting are performed simultaneously, the processing of the semiconductor wafer and the cutting of the protective film-forming film or protective film can be performed simultaneously by dicing such as blade dicing using a blade, laser dicing by laser irradiation, or water dicing by spraying water containing an abrasive. In addition, by expanding a semiconductor wafer on which a modified layer has been formed by Stealth Dicing (registered trademark) and which has not been divided (processed) together with a protective film-forming film or a protective film in a manner similar to that described above, it is possible to simultaneously divide (process) the semiconductor wafer and cut the protective film-forming film or protective film.

[0237] When cutting is performed before processing, the protective film-forming film or protective film can be cut without processing the semiconductor wafer by using the same dicing techniques as described above, and the semiconductor wafer can then be processed (divided) by breaking.

[0238] The method for manufacturing a substrate device according to this embodiment will be described below by taking a semiconductor wafer as an example of a workpiece and a semiconductor chip as an example of a workpiece.

[0239] <<Manufacturing method (1)>> 3 is a cross-sectional view for explaining an example of a method for manufacturing a substrate device when a workpiece is a semiconductor wafer. Here, a manufacturing method will be explained using the composite sheet 101 for forming a protective film shown in FIG. In this specification, the method for manufacturing a substrate device using the composite sheet for forming a protective film may be referred to as "manufacturing method (1)".

[0240] <Attachment process (1)> In the bonding step (sometimes referred to as "bonding step (1)" in this specification) of the manufacturing method (1), a composite sheet 101 for forming a protective film from which the release film 15 has been removed is used, and the protective film-forming film 13 in the composite sheet 101 for forming a protective film is bonded to a surface (back surface) 9b opposite to a surface (circuit surface) 9a having protruding electrodes of the semiconductor wafer 9. This produces a semiconductor wafer 901 with a composite sheet for forming a protective film, which is configured to include the semiconductor wafer 9 and the composite sheet 101 for forming a protective film provided on the back surface 9b of the semiconductor wafer 9, as shown in FIG. 3(a). The semiconductor wafer 9 is a workpiece, and the semiconductor wafer 901 with a composite sheet for forming a protective film is a workpiece with a composite sheet for forming a protective film.

[0241] In the attaching step (1), the protective film-forming film 13 may be softened by heating and attached to the semiconductor wafer 9. Here, bumps and the like on the circuit surface 9a of the semiconductor wafer 9 are omitted from the illustration. This also applies to the subsequent figures.

[0242] The back surface 9b of the semiconductor wafer 9 may be ground to adjust the thickness to a desired value. That is, the back surface 9b of the semiconductor wafer 9 may be a ground surface.

[0243] <Thermosetting process (1)> After the attachment step (1) of the manufacturing method (1), in the thermal curing step (sometimes referred to as "thermal curing step (1)" in this specification), the protective film-forming film 13 is thermally cured to form a protective film 13'. As a result, as shown in FIG. 3(b), a semiconductor wafer 9011 with a cured composite sheet for forming a protective film is produced, which is configured to include a semiconductor wafer 9 and a cured composite sheet for forming a protective film 1011 provided on the back surface 9b of the semiconductor wafer 9. The semiconductor wafer 9011 with a cured composite sheet for forming a protective film is a workpiece with a cured composite sheet for forming a protective film.

[0244] The first surface 13a' of the protective film 13' corresponds to the first surface 13a of the protective film-forming film 13, and the second surface 13b' of the protective film 13' corresponds to the second surface 13b of the protective film-forming film 13.

[0245] In the thermal curing step (1), the heating temperature and heating time of the protective film-forming film 13 when the protective film-forming film 13 is thermally cured are as described above.

[0246] <Processing and cutting process (1)> In the manufacturing method (1), after the thermal curing step (1), the semiconductor wafer 9 is processed (divided) on the support sheet 10 to produce the semiconductor chips 90, and the protective film 13' is cut (sometimes referred to as "processing and cutting step (1)" in this specification). As a result, as shown in FIG. 3(c), a plurality of semiconductor chips 91 with protective film are produced, each of which includes the semiconductor chip 90 and the protective film 130' after cutting provided on the back surface 90b of the semiconductor chip 90. The semiconductor chip 90 is a workpiece, and the semiconductor chips 91 with protective film are a workpiece with protective film. All of the plurality of semiconductor chips 91 with protective film are aligned and held on one support sheet 10, and the semiconductor chips 91 with protective film and the support sheet 10 constitute a group of semiconductor chips with protective film 910.

[0247] As explained above, the order in which the semiconductor wafer 9 is processed and the protective film 13' is cut is not limited. The method of processing the semiconductor wafer 9 and cutting the protective film 13' is as described above.

[0248] A first surface 130a' of the protective film 130' after cutting corresponds to the first surface 13a' of the protective film 13' before cutting, and a second surface 130b' of the protective film 130' after cutting corresponds to the second surface 13b' of the protective film 13' before cutting. In this specification, the "protective film after cutting" may be simply referred to as the "protective film". A surface (circuit surface) 90 a of the semiconductor chip 90 having protruding electrodes corresponds to the circuit surface 9 a of the semiconductor wafer 9 .

[0249] <Pickup process (1)> After the thermal curing step (1) and the processing and cutting step (1) of the manufacturing method (1), in the pick-up step (sometimes referred to as "pick-up step (1)" in this specification), the protective film-covered semiconductor chip 91 is picked up by being pulled away from the support sheet 10, as shown in Fig. 3(d). This makes it possible to take out the protective film-covered semiconductor chip 91 from the group of protective film-covered semiconductor chips 910. In FIG. 3(d), the pickup direction is indicated by an arrow P.

[0250] The semiconductor chip 91 with the protective film can be picked up by a known method. For example, a vacuum collet or the like can be used as the separating means 7 for separating the semiconductor chip 91 with the protective film from the support sheet 10.

[0251] <Mounting process (1)> After the pick-up step (1) and the thermal curing step (1) of the manufacturing method (1), in the mounting step (sometimes referred to as "mounting step (1)" in this specification), the protruding electrodes (not shown) in the semiconductor chip 91 with the protective film after pick-up are brought into contact with the circuit board 6, more specifically, with the connection pads (not shown) provided on the circuit surface 6a of the circuit board 6, and then the semiconductor chip 91 with the protective film is heated. As a result, as shown in FIG. 3(e), the protruding electrodes in the semiconductor chip 91 with the protective film are melted and electrically connected to the circuit board 6, more specifically, to the connection pads. As a result, the semiconductor chip 91 with the protective film is flip-chip connected to the connection pads on the circuit board 6 at the protruding electrodes therein. In addition, in the substrate 6 in Fig. 3(e), not only the connection pads but also the circuits and the like are omitted. This also applies to Fig. 4 described later.

[0252] The flip-chip connection of the protective film-coated semiconductor chip 91 to the connection pads on the circuit board 6 can be performed by a known method. For example, the temperature to which the protective film-covered semiconductor chip 91 is heated in order to melt the protruding electrodes in the protective film-covered semiconductor chip 91 is preferably 255 to 265°C. By using the protective film-forming film 13, the light reflectance of the protective film after heating at such a high temperature is high, so that it is possible to prevent the design of the device from being impaired. Furthermore, even if the circuit board 6 includes multiple semiconductor chips 91 with protective films and these are heated at a high temperature, and variations in the heating temperature that usually occur occur, variations in color are suppressed in these protective films 130' after heating, and it is easy to obtain a uniform design maintenance effect.

[0253] <Other process (1)> The manufacturing method (1) may or may not include other steps (sometimes referred to in this specification as “other steps (1)”) that do not fall under any of the attaching step (1), the thermosetting step (1), the processing and cutting step (1), the pick-up step (1), and the mounting step (1). The type of the other step (1) and the timing of carrying it out can be arbitrarily selected depending on the purpose and are not particularly limited.

[0254] [Printing process (1)] Another example of the step (1) is a printing step (1) (not shown) in which the second surface of the protective film-forming film or protective film (in FIG. 3, for example, the second surface 13b of the protective film-forming film 13 or the second surface 13b' of the protective film 13') is printed on the protective film-forming film or protective film by irradiating the second surface with laser light. The printing is performed on the second surface of the protective film-forming film or protective film.

[0255] In the printing process (1), laser light is irradiated onto the second surface of the protective film-forming film from outside the support sheet side of the composite sheet for forming a protective film, through the support sheet, or laser light is irradiated onto the second surface of the protective film from outside the support sheet side of the cured composite sheet for forming a protective film, through the support sheet.

[0256] The printing step (1) can be carried out by a known method.

[0257] In this embodiment, the printing step (1) can be carried out after the attaching step (1), and is preferably carried out between the thermal curing step (1) and the processing and cutting step (1).

[0258] [Grinding process (1), backgrind tape removal process (1)] Other examples of the step (1) include a grinding step (1) in which a semiconductor wafer with back-grind tape is used, the back surface of the semiconductor wafer being ground, the back surface of the semiconductor wafer being ground, the back-grind tape being attached to a surface (circuit surface) having protruding electrodes (for example, circuit surface 9a of semiconductor wafer 9 in FIG. 3 ), and a back-grind tape removal step (1) in which, after the grinding step (1), the back-grind tape is removed from the circuit surface of the semiconductor wafer.

[0259] Both the grinding step (1) and the backgrind tape removing step (1) can be carried out by known methods.

[0260] The grinding step (1) is carried out before the attaching step (1). The backgrind tape removing step (1) is preferably carried out after the application step (1).

[0261] <Timing for carrying out the heat curing process (1)> So far, the case where the thermal curing step (1) is performed between the bonding step (1) and the processing and cutting step (1) has been described, but the timing of performing the thermal curing step (1) in the manufacturing method (1) is not limited to this, so long as it is performed after the bonding step (1). For example, the thermal curing step (1) may be performed between the printing step (1) and the processing and cutting step (1), between the processing and cutting step (1) and the pick-up step (1), or between the pick-up step (1) and the mounting step (1).

[0262] <<Manufacturing method (2)>> 4 is a cross-sectional view for explaining a schematic example of a method for manufacturing a substrate device when a workpiece is a semiconductor wafer. Here, a manufacturing method will be explained using the protective film-forming film 13 shown in FIG. In this specification, the method for manufacturing a substrate device using a protective film-forming film that does not constitute a composite sheet for forming a protective film is sometimes referred to as "manufacturing method (2)".

[0263] <Attachment process (2)> In the bonding step of the manufacturing method (2) (sometimes referred to as "bonding step (2)" in this specification), the protective film-forming film 13 that does not constitute a composite sheet for forming a protective film, more specifically, the protective film-forming film 13 from which the first release film 151 has been removed, is bonded to the back surface 9b of the semiconductor wafer. As a result, as shown in FIG. 4(a), a semiconductor wafer 902 with a protective film-forming film is produced, which is composed of the semiconductor wafer 9 and the protective film-forming film 13 provided on the back surface 9b of the semiconductor wafer 9. The semiconductor wafer 902 with a protective film-forming film is a work with a protective film-forming film.

[0264] The attaching step (2) may be the same as the attaching step (1) except that the protective film-forming film 13 having the second release film 152 is used instead of the composite sheet 101 for forming a protective film.

[0265] <Thermosetting process (2)> After the bonding step (2) of the manufacturing method (2), in the thermal curing step (sometimes referred to as "thermal curing step (2)" in this specification), the protective film-forming film 13 is thermally cured to form a protective film 13'. As a result, as shown in FIG. 4(b), a semiconductor wafer 9021 with a protective film is produced, which is configured to include a semiconductor wafer 9 and a protective film 13' provided on the back surface 9b of the semiconductor wafer 9. The semiconductor wafer 9021 with a protective film is a work with a protective film.

[0266] The thermal curing step (2) may be the same as the thermal curing step (1) except that a semiconductor wafer 902 with a protective film-forming film is used instead of the semiconductor wafer 901 with a composite sheet for forming a protective film. The protective film-forming film 13 may be thermally cured with the second release film 152 still attached, or may be thermally cured after removing the second release film 152. Fig. 4(b) shows the case where the protective film-forming film 13 is thermally cured after removing the second release film 152.

[0267] <Processing and cutting process (2)> After the attaching step (2) of the manufacturing method (2), in the processing and cutting step (sometimes referred to in this specification as "processing and cutting step (2)"), a processing sheet 80 is attached to a surface (second surface) 13b' of the protective film 13' opposite to the semiconductor wafer 9 side, as shown in Fig. 4(c). This results in a processing sheet and a semiconductor wafer 9022 with a protective film.

[0268] The processing sheet 80 is configured to include a base material 81 and an adhesive layer 82 provided on one surface 81a of the base material 81. The processing sheet 80 has a surface 82a of the adhesive layer 82 opposite to the base material 81 (sometimes referred to as the "first surface" in this specification) attached to the second surface 13b' of the protective film 13'. The first surface 82a of the adhesive layer 82 is synonymous with the first surface 80a of the processing sheet 80.

[0269] The processing sheet 80 may have a structure similar to that of a known dicing sheet, or may have a structure similar to that of the support sheet 10 in the composite sheet 101 for forming a protective film. Here, the case where a processed sheet 80 having an adhesive layer 82 is used is shown, but in manufacturing method (2), a known processed sheet other than the processed sheet 80, such as a processed sheet consisting of only a base material, may also be used.

[0270] The processing sheet 80 can be attached to the protective film-forming film 13 by a known method, for example, by the same method as that used for attaching the protective film-forming composite sheet 101 to the semiconductor wafer 9 in the attachment step (1) of the manufacturing method (1).

[0271] In the processing and cutting step (2), the semiconductor wafer 9 is then processed (divided) on the processing sheet 80 to produce semiconductor chips 90, and the protective film 13' is cut. As a result, a plurality of protective film-coated semiconductor chips 91 are produced, as shown in Fig. 4(d). All of the plurality of protective film-coated semiconductor chips 91 are aligned and held on a single processing sheet 80, and the protective film-coated semiconductor chips 91 and the processing sheet 80 constitute a protective film-coated semiconductor chip group 920. The semiconductor chip 91 with a protective film obtained by the manufacturing method (2) is the same as the semiconductor chip 91 with a protective film obtained by the manufacturing method (1).

[0272] In the processing and cutting step (2), the processing of the semiconductor wafer 9 and the cutting of the protective film 13' can be performed in the same manner as in the processing and cutting step (1), except that a processing sheet and a semiconductor wafer with a protective film 9022 are used instead of the semiconductor wafer with a cured composite sheet for forming a protective film 9011.

[0273] <Pickup process (2)> After the thermal curing step (2) and the processing and cutting step (2) of the manufacturing method (2), in the pick-up step (sometimes referred to as "pick-up step (2)" in this specification), the protective film-covered semiconductor chip 91 is picked up by being pulled away from the processing sheet 80, as shown in Fig. 4(e). This makes it possible to take out the protective film-covered semiconductor chip 91 from the group of protective film-covered semiconductor chips 920. In FIG. 4(e), the pickup direction is indicated by arrow P. The semiconductor chip 91 with the protective film taken out in the pick-up process (2) is the same as the semiconductor chip 91 with the protective film taken out in the pick-up process (1).

[0274] The pick-up step (2) may be the same as the pick-up step (1) except that a group of semiconductor chips with a protective film 920 is used instead of the group of semiconductor chips with a protective film 910.

[0275] <Mounting process (2)> In the manufacturing method (2), the mounting step (sometimes referred to as "mounting step (2)" in this specification) is carried out after the pick-up step (2) and the heat curing step (2). As shown in FIG. 4(f), the mounting process (2) is the same as the mounting process (1), and the semiconductor chip 91 with the protective film is flip-chip connected to the connection pad on the circuit board 6 at the protruding electrodes therein. In this process, the protruding electrodes in the semiconductor chip 91 with the protective film are melted and electrically connected to the connection pads. At this time, as in the case of the manufacturing method (1), the light reflectance of the protective film after heating at a high temperature is high, so that the design of the device is prevented from being damaged. Furthermore, even if the circuit board 6 includes a plurality of semiconductor chips 91 with protective films and these are heated at a high temperature, and there is a normal variation in the heating temperature, the color variation is suppressed in the protective films 130' after heating, and the design maintenance effect is easily achieved uniformly.

[0276] <Other process (2)> The manufacturing method (2) may or may not include other steps (sometimes referred to in this specification as “other steps (2)”) that do not fall under any of the attaching step (2), the thermosetting step (2), the processing and cutting step (2), the pick-up step (2), and the mounting step (2). The type of the other step (2) and the timing of carrying it out can be arbitrarily selected depending on the purpose and are not particularly limited.

[0277] Examples of the other step (2) include the printing step (2), the grinding step (2), and the backgrind tape removing step (2) similar to those in the manufacturing method (1).

[0278] The printing step (2) can be carried out after the attaching step (2), and is preferably carried out between the heat curing step (2) and the processing and cutting step (2). In the printing process (2), for example, printing can be performed on the second surface of the protective film-forming film or protective film by irradiating laser light onto the second surface of the protective film-forming film or protective film from outside the substrate side of the processing sheet, through the processing sheet.

[0279] The grinding step (2) is carried out before the attaching step (2). The backgrind tape removing step (2) is preferably carried out after the attaching step (2).

[0280] <Timing for carrying out the heat curing process (2)> Up to this point, the case where the thermal curing step (2) is performed between the attaching step (2) and the processing and cutting step (2) has been described, but the timing of performing the thermal curing step (2) in the manufacturing method (2) is not limited to this as long as it is performed after the attaching step (2). For example, the thermal curing step (2) may be performed between the printing step (2) and the processing and cutting step (2), between the processing and cutting step (2) and the pick-up step (2), or between the pick-up step (2) and the mounting step (2). EXAMPLES

[0281] The present invention will be described in more detail below with reference to specific examples, although the present invention is not limited to the examples shown below.

[0282] <Raw materials for resin production> The full names of the raw materials for producing the resins, which are abbreviated in the present examples and comparative examples, are shown below. MA: Methyl acrylate HEA: 2-hydroxyethyl acrylate

[0283] <Raw materials for producing the protective film-forming composition> The raw materials used in the production of the composition for forming a protective film are shown below. Among these, the structural formula of the curing accelerator (C) is shown separately. [Polymer component (A)] (A)-1: An acrylic resin (weight average molecular weight: 400,000, glass transition temperature: 6° C.) obtained by copolymerizing MA (85 parts by mass) and HEA (15 parts by mass). [Epoxy resin (B1)] (B1)-1: Bisphenol A type epoxy resin ("jER828" manufactured by Mitsubishi Chemical Corporation, epoxy equivalent: 184-194g / eq) (B1)-2: Dicyclopentadiene type epoxy resin (DIC "Epicron HP-7200", epoxy equivalent 254-264g / eq) [Heat hardener (B2)] (B2)-1: Dicyandiamide (thermally activated latent epoxy resin hardener, "DICY7" manufactured by Mitsubishi Chemical Corporation) [Cure accelerator (C)] (C)-1: Phthalate of DBU ("U-CAT SA810" manufactured by San-Apro Co., Ltd., a thermal base generator) (C)-2: 2-phenyl-4,5-dihydroxymethylimidazole ("Curezol (registered trademark) 2PHZ" manufactured by Shikoku Chemical Industry Co., Ltd.) (C)-3: Phenol salt of DBU ("U-CAT SA1" manufactured by San-Apro Co., Ltd.) (C)-4: 2-ethylhexanoate of DBU ("U-CAT SA102" manufactured by San-Apro Co., Ltd.) (C)-5: DBU formate ("U-CAT SA603" manufactured by San-Apro Co., Ltd.) (C)-6: Triethylmethylammonium 2-ethylhexanoate (a salt composed of triethylmethylammonium cation and 2-ethylhexanoate ion, "SA 18X" manufactured by San-Apro Co., Ltd.) (C)-7: Benzyltriphenylphosphonium bromide (a salt composed of benzyltriphenylphosphonium cation and bromide ion, "U-CAT 5003" manufactured by San-Apro Co., Ltd.) (C)-8: Ethyltriphenylphosphonium methanesulfonate (a salt composed of an ethyltriphenylphosphonium cation and a methanesulfonate ion, San-Apro Co., Ltd. "U-CAT 5050") [Filling material (D)] (D)-1: Silica filler ("SC2050MB" manufactured by Admatechs Co., Ltd., spherical silica filler surface-modified with an epoxy compound, average particle size 0.5 μm, maximum particle size 2.0 μm) [Coupling agent (E)] (E)-1: Silane coupling agent ("X-41-1056" manufactured by Shin-Etsu Chemical Co., Ltd., epoxy equivalent 280 g / eq, oligomer type silane coupling agent having epoxy groups, methyl groups, and methoxy groups) [Colorant (I)] (I)-1: Titanium oxide (white pigment, rutile-type titanium dioxide surface-treated with an inorganic compound having a hydroxyl group, average particle size 0.35 μm) (I)-2: Pigment obtained by pigmenting phthalocyanine blue pigment (Pigment Blue 15:3) / styrene acrylic resin=1 / 3 (mass ratio).

[0284] [ka]

[0285] [Example 1] <<Protective Film Forming Film Manufacturing>> <Production of protective film-forming composition (III)> Polymer component (A)-1 (125 parts by mass), epoxy resin (B1)-1 (60 parts by mass), epoxy resin (B1)-2 (40 parts by mass), heat curing agent (B2)-1 (2.4 parts by mass), filler (D)-1 (360 parts by mass), coupling agent (E)-1 (0.1 parts by mass) and colorant (I)-1 (24.5 parts by mass) were dissolved or dispersed in methyl ethyl ketone and stirred at 23 ° C. to obtain a thermosetting protective film forming composition (III) in which the total concentration of all components other than the solvent is 50 mass%. The blending amounts of all components other than methyl ethyl ketone shown here are the blending amounts of the target product excluding the solvent.

[0286] <Production of protective film-forming film> A release film (second release film, "SP-PET50 2150" manufactured by Lintec Corporation, thickness 50 μm) made of polyethylene terephthalate film, one side of which had been treated for release by silicone treatment, was used, and the protective film-forming composition (III) obtained above was applied to the release-treated surface, followed by drying at 100°C for 2 minutes to produce a thermosetting protective film-forming film (thickness 25 μm).

[0287] Furthermore, a release film (first release film, "SP-PET38 1031" manufactured by Lintec Corporation, thickness 38 μm) in which one side of a polyethylene terephthalate film had been subjected to a release treatment by silicone treatment was used, and the release-treated side of this first release film was attached to the exposed surface of the protective film-forming film obtained above on the side not provided with the second release film. As a result, a laminated film was obtained that was composed of one layer (single layer) of protective film-forming film, a first release film provided on one side of the protective film-forming film, and a second release film provided on the other side of the protective film-forming film.

[0288] <<Evaluation of protective film formation film>> <Measurement of light reflectance RH(x) and light reflectance RL(x), and calculation of light reflectance difference ΔRH(x) and rate of change in light reflectance> [Manufacturing of silicon wafers with protective film] The back surface of the silicon wafer was ground with a #2000 wheel to obtain a silicon wafer having a thickness of 350 μm. The first release film was removed from the protective film-forming film in the laminated film obtained above. Using a roller heated to 70° C., the exposed surface of the protective film-forming film (the surface that had the first release film) was attached to the ground surface of the silicon wafer after back grinding (attachment step (2)). Furthermore, the second release film was removed from the protective film-forming film to obtain a silicon wafer with a protective film-forming film, which was configured to include a silicon wafer and a protective film-forming film provided on the back surface (ground surface) of the silicon wafer. The obtained silicon wafer with the protective film-forming film was heated at 140°C for 2 hours to thermally cure the protective film-forming film into a protective film, thereby obtaining a silicon wafer with a protective film comprising a silicon wafer and a protective film provided on the back surface thereof (thermal curing process (2)).

[0289] [Measurement of light reflectance RH(x) and calculation of light reflectance difference ΔRH(x)] The obtained silicon wafer with the protective film was heated at 260° C. for 5 minutes to obtain a heated silicon wafer with a protective film. The amount of total reflected light, which is a combination of specular reflected light (specular reflected light) and diffuse reflected light, was measured for the exposed surface of the protective film in the heated silicon wafer with protective film (the surface opposite to the silicon wafer) in the entire wavelength range of 380 to 780 nm by the SCI method at 1 nm intervals. Furthermore, the amount of total reflected light was measured for a reference plate made of barium sulfate by the same method as above. In both cases, the amount of total reflected light was measured using a UV-Vis spectrophotometer (Shimadzu Corporation's "UV-VIS-NIR SPECTROPHOTOMETER UV-3600"). In addition, Shimadzu Corporation's "Large Sample Chamber MPC-3100" was used as the sample holder, and Shimadzu Corporation's "Integrating Sphere Accessory ISR-3100" was used as the integrating sphere, with the incident angle of the incident light on the measurement object being 8°. Then, the ratio of the measured value of the protective film to the measured value of the reference plate ([measured value of total light reflected light from protective film] / [measured value of total light reflected light from reference plate]×100), i.e., the relative total light reflectance of the protective film, was calculated and used as the light reflectance RH(x) (x=380 to 780). Of these light reflectances RH(x), the maximum value RH(x)max and the minimum value RH(x)min in the wavelength range of 400 to 700 nm were obtained, and the light reflectance difference ΔRH(x) (=RH(x)max-RH(x)min) was calculated from these values. The results are shown in Table 1.

[0290] [Measurement of light reflectance RL(x), calculation of the rate of change in light reflectance, calculation of |rate of change in light reflectance|max] The optical reflectance RL(x) (x=380 to 780) was measured in the same manner as in measuring the optical reflectance RH(x) described above, except that the silicon wafer with the protective film was heated at 200°C for 5 minutes instead of at 260°C for 5 minutes. Furthermore, in the wavelength range of 400 to 700 nm (x = 400 to 700), 301 change rates of light reflectance (= (RL (x) - RH (x)) / RL (x) × 100) at the same wavelength (same x value) were calculated from RL (x) and RH (x), and the maximum value of these absolute values ​​(|Change rate of light reflectance| max) was calculated. The results are shown in Table 1.

[0291] <Measurement of storage modulus E'(23) of protective film> A test laminate sheet (thickness 200 μm) was produced by laminating the protective film-forming films (thickness 25 μm) among the eight laminate films obtained above onto each other while removing the first release film and the second release film. The obtained test laminate sheet was heated in an oven (in an atmospheric atmosphere) at 140° C. for 2 hours to thermally cure all the protective film-forming films constituting the test laminate sheet to form protective films. A test piece having a width of 4.5 mm, a length of 30 mm, and a thickness of 200 μm was cut out from the heated test laminate sheet thus obtained.

[0292] The storage modulus E' of the test piece (protective film) was measured using a dynamic mechanical analyzer ("DMA Q800" manufactured by TA Instruments) while increasing the temperature at a constant rate under the following conditions. Among them, the measurement result of the storage modulus E' (23) when the temperature of the test piece was 23°C is shown in Table 1. [Measurement conditions] Measurement mode: Pull mode Distance between chucks (length of E' measurement part of test piece): 20mm Measurement start temperature: 0℃ End of measurement temperature: 300℃ Heating rate: 3℃ / min Frequency: 11Hz Measurement atmosphere: Air

[0293] <Evaluation of the design retention effect of heated protective film> [Manufacturing of silicon chips with protective film] A silicon wafer with a protective film was produced in the same manner as in the measurement of the optical reflectance RH(x) and the optical reflectance RL(x) described above, except that a silicon wafer with a thickness of 100 μm was used. A dicing tape ("ADWILL D-676H" manufactured by Lintec Corporation) was attached to the exposed surface of the protective film in the obtained silicon wafer with the protective film. Next, the silicon wafer was divided into silicon chips measuring 2 mm x 2 mm using a dicing blade, and the protective film was simultaneously cut along the periphery of the silicon chip, thereby obtaining a silicon chip with the protective film, which was composed of a silicon chip and the protective film after cutting provided on the back surface of the silicon chip (processing and cutting step (2)). Next, the five silicon chips with the protective film were picked up by detaching them from the dicing tape (pickup step (2)).

[0294] [Evaluation of the design retention effect of heated protective film] The five silicon chips with protective film obtained above were placed in the center of the heating chamber of an oven (SPHH series manufactured by Espec Corporation), where the temperature was stable, and heated at 260°C for 5 minutes. After that, they were allowed to cool to room temperature, thereby obtaining heated silicon chips with protective film. A white circuit board (size: 70 mm×30 mm) with a light reflectance of 39% or more over the entire wavelength range of 400 to 700 nm was prepared. The five heated silicon chips with protective film were placed on the white surface of the white circuit board with a space between them, with the exposed surface of the protective film (the surface opposite to the silicon chip) in the heated silicon chip with protective film facing the same direction as the white surface of the white circuit board. Three evaluators visually observed the five heated silicon chips with protective film in this state (placed on the white circuit board) for three seconds from a position 0.5 m above them under the light of a fluorescent lamp (60W bulb-shaped fluorescent lamp) placed 1.5 m directly above the evaluators and 2.0 m directly above the white circuit board. Then, based on the number of evaluators (hereinafter referred to as "visual evaluators") who visually recognized at least one heated silicon chip with protective film, the design preservation effect of the heated protective film was evaluated according to the following criteria. The results are shown in Table 1. [Evaluation Criteria] A: There were no visual evaluators (0 people), and the heated protective film had an extremely high effect of maintaining the design, so it passed. B: Visual evaluation by one person. The heated protective film has a high effect of maintaining the design, and is passed. C: The number of visual evaluators was 2 or 3, and the heated protective film had a low effect of maintaining the design, and was unacceptable.

[0295] <Evaluation of the effect of suppressing color variation of heated protective film due to differences in the position where the protective film is inserted in the reflow furnace> [Manufacturing of silicon chips with protective film] A silicon wafer with a protective film was produced in the same manner as in the measurement of the optical reflectance RH(x) and the optical reflectance RL(x) described above, except that a silicon wafer with a thickness of 100 μm was used. Next, the size of the silicon chip was changed from 2 mm x 2 mm to 5 mm x 5 mm, and the protective film was cut along the outer periphery of the silicon chip. In the same manner as in the evaluation of the design retention effect of the heated protective film described above, a silicon chip with a protective film was manufactured, and five silicon chips with a protective film were separated from the dicing tape and picked up (processing and cutting process (2), pick-up process (2)).

[0296] [Evaluation of the effect of suppressing color variation of heated protective film] The five silicon chips with protective film obtained above were placed on the transport conveyor of a reflow furnace ("STR-2010M" manufactured by Senju Metals Co., Ltd.), with one of the five silicon chips with protective film being placed at the center in the width direction of the transport conveyor (direction perpendicular to the moving direction of the conveyor), and the five silicon chips with protective film were placed at intervals of 50 mm from each other in the width direction of the transport conveyor. In addition, the exposed surfaces of the protective film (the surfaces opposite to the silicon chip side) of the five silicon chips with protective film all faced in the same direction as the transport surface of the transport conveyor (i.e., facing upward).

[0297] In the reflow furnace, the preheating temperature was set to 160° C., and the maximum temperature that the protective film-equipped silicon chips reached at the center of the width direction of the transport conveyor was set to 260° C. The transport conveyor was advanced into the reflow furnace at a transport speed of 1.7 cm / min. Thus, the five protective film-equipped silicon chips placed on the transport conveyor as described above were put into the reflow furnace and heated. Next, the same white circuit board as above was prepared, and three evaluators visually observed the five heated silicon chips with protective films carried out from the reflow furnace for three seconds from a position 0.3 m above them under the light of a fluorescent lamp (60W bulb-shaped fluorescent lamp) placed 1.5 m above the evaluators and 2.0 m above the white circuit board. Then, based on the number of evaluators (hereinafter referred to as "visual evaluators" as above) who visually recognized the color variation of at least one heated protective film (color variation between protective films), the effect of suppressing the color variation of the heated protective film was evaluated according to the following criteria. The results are shown in Table 1. [Evaluation Criteria] A: There were no visual evaluators (0 people), and the effect of suppressing color variation of the heated protective film was extremely high, so it is acceptable. B: Visual evaluation by one person. The heated protective film has a high effect of suppressing color variation, and is acceptable. C: The number of visual evaluators was 2 or 3, and the effect of suppressing the variation in color of the heated protective film was low, so it was unacceptable.

[0298] <<Production and evaluation of protective film>> [Examples 2 to 9, Comparative Examples 1 to 2] A protective film-forming film was produced and evaluated in the same manner as in Example 1, except that either or both of the types and amounts of the components blended during the production of the protective film-forming composition (III) were changed so that the types and contents of the components contained in the protective film-forming composition (III) were as shown in Table 1 or Table 2. The results are shown in Table 1 or Table 2.

[0299] In Tables 1 and 2, in the "Components (content (parts by mass))" column of "Protective film-forming film," a "-" means that the component is not blended (does not contain the component). In Tables 1 and 2, in the column "Property ratio of imidazole-based curing accelerator content (mass %)" in the column "Protective film-forming film" means "Property ratio of imidazole-based curing accelerator content (mass %) in the protective film-forming film relative to the total mass of the protective film-forming film." In Tables 1 and 2, in the column "Proportion of white pigment content (mass %)" in the column "Protective film-forming film" means "the proportion of white pigment content (mass %) in the protective film-forming film relative to the total mass of the protective film-forming film." In Table 1, the notation "-" in the "Evaluation Results" column means that the evaluation of that item has not been carried out.

[0300] [Table 1]

[0301] [Table 2]

[0302] As is clear from the above results, in Examples 1 to 9, RH(x)min was 28.1% or more, and the light reflectance was high even when the protective film was heated at a high temperature of 260°C. The protective film-forming films of Examples 1 to 9 contained a white pigment, but did not contain imidazole-based compounds such as imidazole-based curing accelerators. In the protective film-forming films of Examples 1 to 9, the ratio of the content of the white pigment to the total mass of the protective film-forming film was 3.99 mass% or more.

[0303] The protective film-coated films of Examples 1 to 2 and 4 to 9 and the protective films immediately after formation were white, and even after heating at 260° C., the heated protective film had a high effect of maintaining the design. The protective film-formed film of Example 3 contains a phthalocyanine blue pigment in addition to a white pigment, and the protective film-formed film of Example 3 and the protective film immediately after formation were a light bluish white (light bluish white). The color of this protective film was a light light blue after heating at 260°C, but the design retention effect was high. In Examples 1 to 9, ΔRH(x) was 16% or less, and particularly in Examples 1 to 2 and 4 to 9, ΔRH(x) was 12.7% or less.

[0304] Furthermore, the protective films of Examples 1 to 3 had the same color regardless of the placement position (placement position on the transport conveyor) when heated at 260° C., and color variation between heated protective films was suppressed. In Examples 1 to 9, the |rate of change in light reflectance|max was 12.1% or less.

[0305] Furthermore, the storage modulus E'(23) of the protective films of Examples 1 to 9 was 812 MPa or more, and among these, the storage modulus E'(23) of the protective films of Examples 2 to 9 was 1104 MPa or more, which was particularly high. The protective film-forming film of Example 1 did not contain a curing accelerator (C), but the protective film-forming films of Examples 2 to 9 contained a curing accelerator (C) (thermal base generator) other than the imidazole-based curing accelerator.

[0306] In contrast, in Comparative Examples 1 and 2, RH(x)min was 24.6% or less, and the light reflectance was low when the protective film was heated at a high temperature. The protective film-forming film of Comparative Example 1 contained a white pigment, but also contained an imidazole-based curing accelerator, and the influence of the imidazole-based curing accelerator could not be suppressed. The protective film-forming film of Comparative Example 2 contained an imidazole-based curing accelerator, but did not contain a white pigment. In Comparative Example 2, since RH(x)min was extremely low at 14.7%, the storage modulus E' of the protective film was not measured.

[0307] The protective film-formed film of Comparative Example 1 and the protective film immediately after formation were white, but the protective film after heating at 260° C. was light yellow, and the heated protective film had a low effect of maintaining the design. The protective film-formed film of Comparative Example 2 and the protective film immediately after formation were light yellowish white (light yellowish white), but the color of this protective film became darker after heating at 260° C. In other words, the heated protective film had a low effect of maintaining the design.

[0308] Furthermore, the protective film of Comparative Example 2 had a variation in color (between heated protective films) depending on the placement position (placement position on the transport conveyor) when heated at 260° C. In Comparative Example 2, the |rate of change in light reflectance|max was 25.5%. [Industrial Applicability]

[0309] The present invention is a protective film for protecting a workpiece to be mounted on a circuit board having a high light reflectance, such as a white circuit board, and can be used as a protective film for use in a heating environment at high temperatures of around 260°C. [Explanation of symbols]

[0310] 101 Composite sheet for forming protective film REFERENCE SIGNS LIST 10 support sheet, 10a one side (first side) of support sheet, 11 substrate, 12 pressure-sensitive adhesive layer 13: a protective film-forming film; 13a: one surface (first surface) of the protective film-forming film; 13b: a surface (second surface) of the protective film-forming film opposite to the semiconductor wafer side 13'···Protective film, 130'···Protective film after cutting (protective film) 6 Circuit board 80...Processed sheet 9: semiconductor wafer; 9b: surface (back surface) of the semiconductor wafer opposite to the surface having the protruding electrodes 90: semiconductor chip; 90a: surface of the semiconductor chip having protruding electrodes (circuit surface); 90b: surface of the semiconductor chip opposite to the surface having the protruding electrodes (rear surface) 91...Semiconductor chip with protective film

Claims

1. A thermosetting protective film-forming film, A protective film, which is a thermoset of the protective film-forming film, is heated at 260°C for 5 minutes, and the light reflectance of the protective film after heating is measured. The light reflectance is 26% or more in the entire wavelength range of 400 to 700 nm.

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

3. The protective film-forming film is for forming a protective film at any location of a workpiece obtained by processing a workpiece, a protective film-attached workpiece including the workpiece and the protective film provided at any location on the workpiece, the protective film-attached workpiece being intended for mounting on a circuit board; The protective film-forming film according to claim 1 or 2, wherein the circuit board has a light reflectance of 30% or more in the entire wavelength range of 400 to 700 nm.

4. The protective film-forming film according to claim 1 or 2, wherein the content ratio of the imidazole-based curing accelerator to the total mass of the protective film-forming film is less than 0.3 mass%.

5. The protective film-forming film according to claim 1 or 2, wherein the protective film-forming film contains a thermal base generator.

6. After heating at 200° C. for 5 minutes, the light reflectance RL(x) of the protective film was measured at wavelength intervals of 1 nm over the entire wavelength range of 400 to 700 nm; After heating at 260° C. for 5 minutes, the light reflectance RH(x) of the protective film was measured at wavelength intervals of 1 nm over the entire wavelength range of 400 to 700 nm; From the RL(x) and RH(x) at the same wavelength, the following formula: Change in light reflectance (%)=((RL(x)-RH(x)) / RL(x)×100) The protective film-forming film according to claim 1 or 2, wherein, when a rate of change in light reflectance is calculated for each wavelength by the above method, the maximum value among the absolute values ​​of all the rates of change is 18% or less.

7. 3. The protective film-forming film according to claim 1 or 2, wherein when the light reflectance RH(x) of the protective film after heating at 260° C. for 5 minutes is measured at wavelength intervals of 1 nm over the entire wavelength range of 400 to 700 nm, the difference between the maximum value RH(x)max of the light reflectance RH(x) and the minimum value RH(x)min of the light reflectance RH(x) is 13% or less.

8. A method for manufacturing a substrate device using a protective film-forming film or a composite sheet for forming a protective film, The protective film-forming film is the protective film-forming film according to claim 1 or 2, The composite sheet for forming a protective film is configured to include a support sheet and the protective film-forming film according to claim 1 or 2 provided on one surface of the support sheet, The manufacturing method includes a bonding step of bonding the protective film-forming film that does not constitute the composite sheet for forming a protective film, or the protective film-forming film in the composite sheet for forming a protective film, to a surface of a work opposite to a surface having a protruding electrode; a thermal curing step of thermally curing the protective film-forming film to form a protective film after the attaching step; a processing and cutting step in which, when the protective film-forming film that does not constitute the composite sheet for forming a protective film is used after the attaching step, a processing sheet is attached to the surface of the protective film-forming film or protective film opposite to the work side, the work is processed on the processing sheet to produce a workpiece, and the protective film-forming film or protective film is cut; and, when the composite sheet for forming a protective film is used, the work is processed on the support sheet to produce a workpiece, and the protective film-forming film or protective film is cut to produce a workpiece with a protective film-forming film comprising the workpiece and the protective film after cutting provided on the surface opposite to the surface of the workpiece having the protruding electrode, or a workpiece with a protective film comprising the workpiece and the protective film after cutting provided on the surface opposite to the surface of the workpiece having the protruding electrode; A pick-up process for picking up the workpiece with the protective film-forming film or the workpiece with the protective film from the processing sheet or the support sheet after the processing and cutting process; a mounting step of contacting the protruding electrodes in the protective film-attached workpiece with a circuit board after the pick-up step and the thermal curing step, and then heating the protective film-attached workpiece to melt the protruding electrodes and connect them to the circuit board; The method for manufacturing a substrate device includes the steps of:

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