Protective film forming film, composite sheet for protective film forming, method for manufacturing a semiconductor device, and use of protective film forming film

Abstract

To provide a thermosetting film for forming a protective coat, which is used for forming a protective coat on a rear face of a semiconductor chip, on which, even if being not cured, no pin push-up marks remain when being pushed up by a pin of a semiconductor chip and laser printing is retained even after the protective coat is formed, which has good adhesiveness to a semiconductor wafer, and with which a protective coat with high protection performance can be formed.SOLUTION: Provided is a thermosetting film 13 for forming a protective coat. When the storage modulus E' of a first test piece with a width of 4 mm is measured in a temperature range of 23-70°C, the first test piece being a laminate of a plurality of the films 13 for forming a protective coat, the minimum E'(1) of the storage modulus is 45 MPa or less, and the maximum E'( 2) thereof is 200 MPa or more. When the storage modulus E' of a second test piece with a width of 5 mm is measured under the same condition, the second test piece being a cured product obtained by thermosetting a laminate of a plurality of the films 13 for forming a protective coat, the minimum E'(3) of the storage modulus is 500 MPa or more.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a protective film-forming film, a composite sheet for forming a protective film, a method for manufacturing a semiconductor device, and the use of a protective film-forming film. [Background technology]

[0002] Some semiconductor wafers have circuits formed on one side (the circuit side), and further have protruding electrodes such as bumps on that side (the circuit side). Such semiconductor wafers are divided into semiconductor chips, and their protruding electrodes are connected to connection pads on a circuit board, thereby mounting them on the circuit board. In such semiconductor wafers and semiconductor chips, the side opposite the circuit surface (the back surface) is sometimes protected with a protective film to suppress damage such as crack formation.

[0003] To form such a protective film, a protective film-forming film is attached to the back surface of the semiconductor wafer. The protective film-forming film is laminated on a support sheet and may be used as a composite sheet for protective film formation, or it may be used without being laminated on a support sheet. Subsequently, the semiconductor wafer with the protective film-forming film on its back surface (semiconductor wafer with protective film-forming film) is processed through various subsequent processes to become a semiconductor chip with a protective film on its back surface (semiconductor chip with protective film). After being picked up, such a semiconductor chip with a protective film is mounted on the circuit side of a substrate to constitute a semiconductor device. The protective film-forming film forms a protective film, for example, by curing.

[0004] On the other hand, protective film-forming films are sometimes handled in such a way that they do not form a protective film until the semiconductor chip is mounted on the circuit surface of the substrate, and then form the protective film by curing after the semiconductor chip has been mounted on the circuit surface of the substrate. In this case, until the semiconductor chip is mounted on the circuit surface of the substrate, a protective film-forming film that is softer than the protective film is attached to the back surface of the semiconductor wafer or semiconductor chip, which can cause problems.

[0005] For example, when picking up a semiconductor wafer with a protective film attached, the wafer may be pushed up by a pin from the protective film side through a sheet such as a dicing sheet. In this case, pin marks may be left on the protective film, and the appearance of the protective film may be damaged. For example, on a semiconductor wafer with a protective film, laser printing may be performed on the side of the protective film opposite to the semiconductor wafer by irradiating it with laser light. In this case, when the printed protective film is cured, the printing may become unclear or disappear.

[0006] Therefore, it is desirable to solve these problems, and in doing so, the protective film-forming film needs to have adhesive properties that allow it to be well attached to semiconductor wafers, and protective suitability that allows it to form a protective film with high protective performance.

[0007] In contrast, a method for manufacturing a semiconductor device, which includes a step of laser printing on an uncured protective film-forming film, and a protective film-forming film used in this semiconductor device manufacturing method have been disclosed (see Patent Documents 1-2). [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] Japanese Patent Publication No. 2018-81953 [Patent Document 2] Japanese Patent Publication No. 2013-149737 [Overview of the project] [Problems that the invention aims to solve]

[0009] However, it is not clear that the protective film-forming films disclosed in Patent Documents 1 and 2 can solve all of the above-mentioned problems, that is, that the remaining pin push marks are suppressed, the printing by laser irradiation is clearly maintained even in the protective film state, the adhesion to semiconductor wafers is good, and a protective film with high protective performance can be formed.

[0010] The present invention aims to provide a thermosetting protective film-forming film for forming a protective film on the back surface of a semiconductor chip, wherein even when the semiconductor chip with the protective film-forming film attached to the back surface of the semiconductor chip is handled in an uncured state until it is mounted on the circuit surface of a substrate, the remaining pin push marks on the protective film-forming film are suppressed when the semiconductor chip with the protective film-forming film attached is picked up by pin push-up, the printing is clearly retained when laser printing is performed on the protective film-forming film and then the protective film is formed by thermosetting, the film has good adhesion to semiconductor wafers, and it is possible to form a protective film with high protective performance. Furthermore, the present invention aims to provide a composite sheet for forming a protective film equipped with the protective film forming film, and a method for manufacturing a semiconductor device using the protective film forming film or the composite sheet for forming a protective film. [Means for solving the problem]

[0011] To solve the above problems, the present invention adopts the following configuration. [1] A thermosetting protective film, which is a laminate of multiple protective films, is used to measure the storage modulus E' of the first test piece while heating it from -20°C to 150°C in tensile mode under the conditions of a frequency of 11 Hz, a heating rate of 3°C / min, and constant heating, and the minimum value E'(1) of the storage modulus E' in the temperature range of 23 to 70°C is 45 MPa or less. A protective film having a maximum value E'(2) of 200 MPa or more, a cured product obtained by thermally curing a laminate of multiple protective film-forming films, where a second test piece with a width of 5 mm is held at two locations with a 20 mm gap between them, and the storage modulus E' of the second test piece is measured while heating the second test piece from -60°C to 350°C in tensile mode under the conditions of a frequency of 11 Hz, a heating rate of 3°C / min, and constant heating, and the minimum value E'(3) of the storage modulus E' in the temperature range of 23 to 70°C is 500 MPa or more. [2] The protective film forming film according to [1], wherein the protective film forming film contains a curing accelerator (C). [3] The protective film forming film according to [1] or [2], wherein the protective film forming film is a single layer. [4] A composite sheet for forming a protective film, comprising a support sheet and a protective film forming film provided on one surface of the support sheet, wherein the protective film forming film is the protective film forming film described in any one of [1] to [3].

[0012] [5] A method for manufacturing a semiconductor device, the manufacturing method comprising: an attachment step of attaching one side of a protective film forming film described in any one of [1] to [3], or the exposed side of a protective film forming film in a protective film forming composite sheet described in claim 4, to the back surface of a semiconductor wafer; a printing step of performing laser printing on the side of the protective film forming film in the protective film forming composite sheet that is on the support sheet side, if the protective film forming composite sheet is used, or on the other side of the protective film forming film that is not part of the protective film forming composite sheet, if the protective film forming film is not part of the protective film forming composite sheet, if the protective film forming film is not part of the protective film forming composite sheet, if the protective film forming film is not part of the protective film forming composite sheet, if the protective film forming film is not part of the protective film forming composite sheet, if the protective film forming film is not part of the protective film forming composite sheet, on the other side of the protective film forming film A method for manufacturing a semiconductor device, comprising: a processing step of producing a semiconductor chip with a protective film, comprising: attaching a dicing sheet to the semiconductor wafer, dividing the semiconductor wafer into semiconductor chips on the dicing sheet, and cutting the protective film forming film along the division points of the semiconductor wafer, thereby producing a semiconductor chip with a protective film forming film comprising the semiconductor chip and the cut protective film forming film provided on the back surface of the semiconductor chip; a pick-up step of picking up the semiconductor chip with a protective film forming film after the processing step by pulling it away from the dicing sheet or support sheet; a bonding step of bonding the semiconductor chip with a protective film forming film to the circuit surface of a substrate by flip-chip connecting the protruding electrodes in the picked-up semiconductor chip with a protective film forming film to the circuit surface of a substrate after the pick-up step; and a heat curing step of forming a protective film by heat curing the protective film forming film in the semiconductor chip with a protective film forming film after the bonding step. [6]. Use of a protective film forming film for forming a protective film on the back surface of a semiconductor chip obtained by attaching to the back surface opposite to the circuit surface of a semiconductor wafer and dividing the semiconductor wafer, wherein the protective film forming film is the protective film forming film according to any one of [1] to [3].

Effect of the Invention

[0013] According to the present invention, there is provided a thermosetting protective film forming film for forming a protective film on the back surface of a semiconductor chip. Even when it is handled in an uncured state until it is mounted on the circuit surface of a substrate in the state of a semiconductor chip with a protective film forming film provided on the back surface of the semiconductor chip, when the semiconductor chip with the protective film forming film is picked up by pushing up with a pin, the remaining of the pin pushing-up mark on the protective film forming film is suppressed. When laser printing is performed on the protective film forming film and then a protective film is formed by thermosetting, the printing is clearly retained, the adhesiveness to the semiconductor wafer is good, and a protective film forming film capable of forming a protective film with high protective performance is provided. Further, according to the present invention, there are provided a composite sheet for forming a protective film provided with the protective film forming film and a method for manufacturing a semiconductor device using the protective film forming film or the composite sheet for forming a protective film.

Brief Description of the Drawings

[0014] [Figure 1] It is a cross-sectional view schematically showing an example of a protective film forming film according to an embodiment of the present invention. [Figure 2] It is a cross-sectional view schematically showing an example of a composite sheet for forming a protective film according to an embodiment of the present invention. [Figure 3] It is a cross-sectional view schematically showing another example of a composite sheet for forming a protective film according to an embodiment of the present invention. [Figure 4] It is a cross-sectional view for schematically explaining an example of a method for manufacturing a semiconductor device according to an embodiment of the present invention. [Figure 5]This is a schematic cross-sectional view illustrating another example of a method for manufacturing a semiconductor device according to one embodiment of the present invention. [Modes for carrying out the invention]

[0015] ◇ Protective film A protective film-forming film according to one embodiment of the present invention is a thermosetting protective film-forming film, which is a laminate of a plurality of such protective film-forming films, and when a first test piece with a width of 4 mm is held at two locations with a 20 mm gap between them, and the storage modulus E' of the first test piece is measured while heating the first test piece from -20°C to 150°C in tensile mode under the conditions of a frequency of 11 Hz, a heating rate of 3°C / min, and constant heating, the minimum value of the storage modulus E' E'(1) (in this specification, sometimes simply referred to as "E'(1)") is 45 MPa or less, and the maximum value of the storage modulus E' E'(2) The storage modulus E' of the second test piece is measured while heating the second test piece from -60°C to 350°C under the conditions of constant heating, with a storage modulus E' of 200 MPa or more, and the storage modulus E' of the second test piece is measured while heating the second test piece from -60°C to 350°C under the conditions of constant heating, with a second test piece of 5 mm width held at two locations with a distance of 20 mm between them, at a frequency of 11 Hz and a heating rate of 3°C / min, in tensile mode, and the minimum value of the storage modulus E' E' (3) (sometimes simply referred to as "E'(3)" in this specification) is 500 MPa or more. The protective film-forming film of this embodiment can be laminated with a support sheet, for example, as described later, to form a composite sheet for forming a protective film.

[0016] By using the protective film-forming film of this embodiment, or a composite sheet for forming a protective film equipped therewith, a semiconductor chip with a protective film-forming film can be manufactured, comprising a semiconductor chip and a protective film-forming film provided on the back surface of the semiconductor chip. Furthermore, a semiconductor chip with a protective film can be manufactured from the semiconductor chip with a protective film-forming film, comprising a semiconductor chip and a protective film provided on the back surface of the semiconductor chip. Furthermore, a semiconductor device can be manufactured using the semiconductor chip with a protective film.

[0017] The protective film-forming film of this embodiment is suitable for application to a semiconductor device manufacturing method in which the protective film-forming film is not heat-cured (in other words, the protective film is not formed) until the semiconductor chip with the protective film-forming film is flip-chip connected to the circuit surface of the substrate, and the protective film is heat-cured (formed) during the reflow process after the flip-chip connection.

[0018] A circuit is formed on one side of a semiconductor wafer, and in this specification, the side of the semiconductor wafer on which the circuit is formed is referred to as the "circuit side." The side of the semiconductor wafer opposite to the circuit side is referred to as the "back side." A semiconductor wafer is divided into semiconductor chips by means of dicing or other methods. In this specification, as with the semiconductor wafer, the side of the semiconductor chip on which the circuit is formed is referred to as the "circuit side," and the side of the semiconductor chip opposite the circuit side is referred to as the "back side." It is preferable that both the circuit surface of the semiconductor wafer and the circuit surface of the semiconductor chip are provided with protruding electrodes such as bumps and pillars. It is preferable that the protruding electrodes are made of solder.

[0019] Furthermore, semiconductor devices can be manufactured by using the aforementioned semiconductor chip with protective film. In this specification, "semiconductor device" refers to a semiconductor chip with a protective film, which is flip-chip connected to a connection pad on a circuit board at a protruding electrode on the circuit surface of the semiconductor chip.

[0020] The protective film-forming film of this embodiment is thermosetting and functions as a protective film through its thermal curing.

[0021] A protective film-forming film at room temperature is heated to a temperature above room temperature, and then cooled back to room temperature to obtain a heated and cooled protective film-forming film. When the hardness of the heated and cooled protective film-forming film is compared to the hardness of the unheated protective film-forming film at the same temperature, if the heated and cooled protective film-forming film is harder, then this protective film-forming film is thermosetting.

[0022] The protective film-forming film of this embodiment may consist of one layer (single layer) or of two or more layers. When the protective film-forming film consists of multiple layers, these layers may be identical or different from each other, and the combination of these layers is not particularly limited.

[0023] In this specification, not only in the case of protective film-forming films, "multiple layers may be identical or different from one another" means "all layers may be identical, all layers may be different, or only some layers may be identical," and further, "multiple layers are different from one another" means "at least one of the constituent materials and thickness of each layer is different from the other."

[0024] In particular, the protective film-forming film of this embodiment is preferably a single layer. Having a single layer of protective film-forming film highly suppresses delamination of the protective film-forming film or protective film from adjacent layers during the reflow process. Furthermore, unlike multi-layer protective film-forming films, a single-layer protective film-forming film does not experience inter-layer migration of its components during storage, resulting in higher storage stability. Moreover, a single-layer protective film-forming film is easier to manufacture.

[0025] <<E’(1)> > The measurement of the storage modulus E' involving the protective film-forming film before curing (uncured) is performed by creating a laminate with a width of 4 mm by laminating and cutting out multiple protective film-forming films, and using this laminate as the first test specimen. More specifically, the first test specimen is held at two locations with a 20 mm gap between them, and in this state, the storage modulus E' of the first test specimen is measured while the first test specimen is heated at a constant rate of 3 °C / min from -20 °C to 150 °C under conditions of a frequency of 11 Hz. Holding the first test specimen at two points with a 20 mm gap between them means that the length of the portion of the first test specimen being measured for its storage modulus E' is 20 mm.

[0026] The first test specimen can be held at the two locations mentioned above using, for example, a known gripping device or other holding means.

[0027] The thickness of the first test specimen (the laminate) is not particularly limited, as long as it does not hinder the performance of the test and does not impair the measurement accuracy of the storage modulus E'. Typically, the thickness of the first test specimen is preferably 190 to 210 μm, more preferably 195 to 205 μm, and particularly preferably 200 μm.

[0028] The number of protective film-forming films constituting the first test specimen is not particularly limited, as long as there are two or more films, and can be arbitrarily selected according to the thickness of each protective film-forming film. For example, a first test specimen with a thickness of 200 μm can be prepared using five protective film-forming films with a thickness of 40 μm each. Alternatively, a first test specimen with a thickness of 200 μm can be prepared using eight protective film-forming films with a thickness of 25 μm each. However, these are just examples, and the number and thickness of protective film-forming films used are not limited to these.

[0029] In this embodiment, the minimum storage modulus E'(1) of the first test specimen in the temperature range of 23 to 70°C is 45 MPa or less. Thus, by having a certain level of softness or higher at any temperature, the adhesive properties of the protective film to the semiconductor wafer are improved. E'(1) may be, for example, 40 MPa or less, 30 MPa or less, or 15 MPa or less. The smaller E'(1) is, the better the adhesive properties of the protective film to the semiconductor wafer. The lower limit of E'(1) is not particularly limited. For example, in order to easily obtain a protective film, E'(1) may be 0.01 MPa or higher. In one embodiment, E'(1) may be, for example, 0.01 to 45 MPa, 0.01 to 40 MPa, 0.01 to 30 MPa, and 0.01 to 15 MPa. However, these are just examples of E'(1).

[0030] E'(1) is typically the storage modulus E' of the first test specimen when the temperature of the first test specimen is 70°C. A temperature of around 70°C (for example, 65-75°C) is suitable as the heating temperature of the protective film-forming film (attachment temperature of the protective film-forming film) when attaching the protective film-forming film to a semiconductor wafer.

[0031] <<E’(2)> > In this embodiment, the maximum value E'(2) of the storage modulus E' of the first test specimen in the temperature range of 23 to 70°C is 200 MPa or more. In this way, by having a certain level of hardness at any temperature, as will be described later, when a silicon chip with the protective film attached is picked up by pin push-up during the semiconductor device manufacturing process, the remaining pin push-up marks on the protective film are suppressed. Furthermore, when laser printing is performed on the protective film and then a protective film is formed by heat curing, the printing is clearly retained on the protective film. E'(2) may be, for example, 250 MPa or more, 350 MPa or more, or 450 MPa or more. The larger E'(2) is, the greater the effect of suppressing the remaining pin push-up marks and the effect of clearly retaining the printing on the protective film. The upper limit of E'(2) is not particularly limited. For example, E'(2) may be 800 MPa or less, in order to easily obtain a protective film. In one embodiment, E'(2) may be, for example, 250-800 MPa, 350-800 MPa, and 450-800 MPa. However, these are just examples of E'(2).

[0032] E'(2) is the storage modulus E' of the first test specimen when the temperature of the first test specimen is typically 23°C. A temperature of around 23°C (e.g., 18-28°C) is suitable for the protective film when laser printing is performed on the protective film and when the silicon chip with the protective film attached is picked up by pin thrust.

[0033] <<E’(3)> > The measurement of the storage modulus E' related to the thermoset product of the protective film formation film is performed by creating a laminate by stacking and cutting multiple protective film formation films, and then using a 5 mm wide cured product obtained by thermosetting this laminate as the second test specimen. More specifically, the second test specimen is held at two locations with a 20 mm gap between them, and in this state, the storage modulus E' of the second test specimen is measured while the second test specimen is heated at a constant rate of 3 °C / min from -60 °C to 350 °C under conditions of a frequency of 11 Hz. Holding the second test specimen at two points with a 20 mm gap between them means that the length of the portion of the second test specimen being measured for its storage modulus E' is 20 mm.

[0034] The second test specimen can be held at the two locations in the same manner as the first test specimen was held at the two locations described above.

[0035] The thickness of the second test specimen (the cured material) is not particularly limited, as long as it does not hinder the performance of the test and does not impair the measurement accuracy of the storage modulus E'. Typically, the thickness of the second test specimen is preferably 190 to 210 μm, more preferably 195 to 205 μm, and particularly preferably 200 μm.

[0036] The number of protective film-forming films constituting the laminate used to prepare the second test specimen is not particularly limited as long as there are two or more films, and can be arbitrarily selected according to the thickness of each protective film-forming film. For example, by using five protective film-forming films with a thickness of 40 μm, a laminate with a thickness of 200 μm and a second test specimen can be prepared. Alternatively, by using eight protective film-forming films with a thickness of 25 μm, a laminate with a thickness of 200 μm and a second test specimen can be prepared. Typically, the thickness of the laminate and the thickness of the second test specimen are the same. However, these are just examples, and the number and thickness of protective film-forming films used are not limited to these.

[0037] In this embodiment, the minimum storage modulus E'(3) of the second test specimen in the temperature range of 23 to 70°C is 500 MPa or higher. Thus, by having a certain level of hardness or higher at any temperature, the protective film has high protective performance. E'(3) may be, for example, 2000 MPa or higher, 3500 MPa or higher, 5000 MPa or higher, or 6500 MPa or higher. The larger E'(3) is, the better the protective performance of the protective film. The upper limit of E'(3) is not particularly limited. For example, in terms of easily obtaining a protective film, E'(3) may be 10,000 MPa or less. In one embodiment, E'(3) may be, for example, any of 500-10000 MPa, 2000-10000 MPa, 3500-10000 MPa, 5000-10000 MPa, and 6500-10000 MPa. However, these are just examples of E'(3).

[0038] E'(3) is the storage modulus E' of the second test specimen when the temperature of the second test specimen is typically 23°C. Temperatures of around 23°C (e.g., 18-28°C) are typically the temperatures at which articles with protective coatings, such as semiconductor chips with protective coatings, are frequently handled.

[0039] In this embodiment, it is preferable that E'(1) and E'(2) of the first test specimen, and E'(3) of the second test specimen, are all within one of the above numerical ranges. For example, an example of a preferred protective film-forming film is one in which E'(1) is one of 0.01 to 45 MPa, 0.01 to 40 MPa, 0.01 to 30 MPa, and 0.01 to 15 MPa, E'(2) is one of 250 to 800 MPa, 350 to 800 MPa, and 450 to 800 MPa, and E'(3) is one of 500 to 10000 MPa, 2000 to 10000 MPa, 3500 to 10000 MPa, 5000 to 10000 MPa, and 6500 to 10000 MPa.

[0040] The storage modulus E' of the first test specimens, including E'(1) and E'(2), and the storage modulus E' of the second test specimens, including E'(3), can both be adjusted by adjusting the type and content of the components contained in the protective film-forming film. For example, if the protective film-forming film contains a polymer component (A) described later, the storage modulus E' of the first and second test specimens can be more easily adjusted by adjusting the type and amount of constituent units of the polymer component (A). More specifically, for example, the storage modulus E' of the first and second test specimens can be more easily adjusted by adjusting the Tg of the polymer component (A), particularly by using an acrylic resin described later as the polymer component (A) and adjusting the glass transition temperature (Tg) of the acrylic resin. By selecting a polymer component (A) with a higher Tg, it tends to be easier to reduce E'(1) and increase E'(2) and E'(3). For example, if the protective film-forming film contains a filler (D) described later, the storage modulus E' of the first and second test specimens (especially E'(1), E'(2), and E'(3)) can be more easily adjusted by adjusting the content of the filler (D) in the protective film-forming film.

[0041] The thickness of the protective film is not particularly limited. The thickness of the protective film is preferably 50 μm or less, and may be, for example, 40 μm or less, or 30 μm or less. By keeping the thickness of the protective film below the upper limit, it is possible to avoid the protective film being excessively thick. On the other hand, the thickness of the protective film is preferably 5 μm or more, in order to form a protective film with higher protective performance. In one embodiment, the thickness of the protective film-forming film may be, for example, 5 to 50 μm, 5 to 40 μm, or 5 to 30 μm. However, these are just examples of the thickness of the protective film-forming film.

[0042] In this specification, "thickness of protective film" means the total thickness of the protective film. For example, the thickness of a protective film consisting of multiple layers means the total thickness of all layers constituting the protective film.

[0043] In this specification, "thickness," unless otherwise specified, refers to the average of the thicknesses measured at five randomly selected locations on the object, and can be obtained using a constant-pressure thickness measuring instrument in accordance with JIS K7130.

[0044] The curing conditions when the protective film-forming film is attached to the desired location on the semiconductor wafer and heat-cured to form a protective film are not particularly limited, as long as the degree of curing is sufficient for the protective film to fully perform its function, and can be appropriately selected depending on the type of protective film-forming film.

[0045] For example, the heating temperature during the thermosetting of the protective film may be any of the following: 100-200°C, 120-195°C, or 140-190°C. The heating time during the heat curing process can be set appropriately, taking into account the heating temperature. For example, it may be 3 minutes to 5 hours, 3 minutes to 1 hour, or 3 to 30 minutes.

[0046] The protective film-forming film of this embodiment can be attached to the back surface of a semiconductor wafer opposite to the circuit surface, and can be used to form a protective film on the back surface of a semiconductor chip obtained by dividing the semiconductor wafer. The protective film-forming film of this embodiment has good adhesion to the back surface of the semiconductor wafer and provides high protection performance for semiconductor chips. The protective film-forming film of this embodiment is further suitable for printing on the side opposite to the semiconductor wafer after it has been attached to the back surface of the semiconductor wafer by irradiation with laser light. Such printing is clearly retained on the protective film when the protective film is formed by the thermal curing of the protective film-forming film. The protective film-forming film of this embodiment is further suitable for picking up a semiconductor chip equipped with the aforementioned protective film, i.e., a semiconductor chip with a protective film, from a support sheet or dicing sheet used during the splitting of a semiconductor wafer, by pushing up with pins. When picked up in this manner, the protective film-forming film provided on the back surface of the semiconductor chip suppresses the retention of pin push-up marks.

[0047] <<Composition for forming protective film>> The protective film-forming film can be formed using a protective film-forming composition (more specifically, a thermosetting protective film-forming composition) containing its constituent materials. For example, a protective film-forming film can be formed by coating the surface to be formed with the protective film-forming composition and drying it as necessary. The ratio of components that do not vaporize at room temperature in the protective film-forming composition is usually the same as the ratio of those components in the protective film-forming film. In this specification, "room temperature" means a temperature that is not particularly cooled or heated, i.e., a normal temperature, such as 15 to 25°C.

[0048] The protective film forming the aforementioned protective film may have energy ray curability in addition to thermosetting properties.

[0049] In this specification, "energy beam" means an electromagnetic wave or charged particle beam that has an energy quantum, and examples include ultraviolet rays, radiation, and electron beams. Ultraviolet rays can be irradiated, for example, by using high-pressure mercury lamps, fusion lamps, xenon lamps, black lights, or LED lamps as ultraviolet light sources. Electron beams can be irradiated using those generated by electron accelerators, etc. In this specification, "energy ray curable" means the property of hardening when irradiated with energy rays, and "non-energy ray curable" means the property of not hardening even when irradiated with energy rays.

[0050] In a protective film, the ratio of the total content of one or more of the following components in the protective film to the total mass of the protective film is not more than 100% by mass. Similarly, in a protective film-forming composition, the ratio of the total content of one or more of the following components of the protective film-forming composition to the total mass of the protective film-forming composition shall not exceed 100% by mass.

[0051] The coating of the protective film-forming composition can be carried out by known methods, such as using various coaters including air knife coaters, blade coaters, bar coaters, gravure coaters, roll coaters, roll knife coaters, curtain coaters, die coaters, knife coaters, screen coaters, Meyer bar coaters, and kiss coaters.

[0052] The drying conditions for the protective film-forming composition are not particularly limited. However, if the protective film-forming composition contains a solvent as described later, it is preferable to heat-dry it. When a protective film-forming composition containing a solvent is heat-dried, it is preferable to heat-dry it at, for example, 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 in a way that prevents the composition itself and the thermosetting protective film-forming film formed from it from becoming thermosetting.

[0053] A preferred protective film-forming film is one containing a curing accelerator (C), and a more preferred protective film-forming film is one containing a polymer component (A), a thermosetting component (B), and a curing accelerator (C). The polymer component (A) is a component that can be considered to have been formed by a polymerization reaction of polymerizable compounds. The thermosetting component (B) is a component that can undergo a curing (polymerization) reaction triggered by heat. In this specification, polymerization reactions also include polycondensation reactions. The composition of the protective film-forming composition will be described in detail below.

[0054] <Protective film forming composition (III)> Examples of preferred protective film-forming compositions include protective film-forming composition (III) containing a curing accelerator (C) (which may be simply referred to as "composition (III)" in this specification). It is more preferable that protective film-forming composition (III) contains a polymer component (A), a thermosetting component (B), and a curing accelerator (C).

[0055] [Polymer component (A)] Polymer component (A) is a polymer compound that imparts film-forming properties, flexibility, and other characteristics to the protective film-forming film. In this specification, the polymer compound also includes products of polycondensation reactions.

[0056] The polymer component (A) contained in composition (III) and the protective film-forming film may be one type or two or more types, and if there are two or more types, their combination and ratio can be arbitrarily selected.

[0057] Examples of polymer component (A) include acrylic resin, urethane resin, phenoxy resin, silicone resin, saturated polyester resin, etc., with acrylic resin being preferred.

[0058] Examples of the acrylic resin in polymer component (A) include known acrylic polymers. The weight-average molecular weight (Mw) of the acrylic resin is preferably 10,000 to 2,000,000, more preferably 1,000,000 to 1,500,000, even more preferably 1,500,000 to 1,200,000, and particularly preferably 200,000 to 1,000,000. Having a weight-average molecular weight of the acrylic resin above the lower limit makes it easier to increase E'(160) and E'(170). Having a weight-average molecular weight of the acrylic resin below the upper limit makes it easier for the protective film-forming film to conform to the uneven surface of the adherend.

[0059] In this specification, "weight-average molecular weight" refers to the polystyrene equivalent value measured by gel permeation chromatography (GPC) unless otherwise specified.

[0060] The glass transition temperature (Tg) of the acrylic resin is preferably 0 to 70°C, and may be, for example, 0 to 50°C, 0 to 30°C, and 0 to 10°C, or 10 to 70°C and 20 to 70°C, or 10 to 50°C and 10 to 30°C. Having the Tg of the acrylic resin above the lower limit makes it easier to adjust E'(1), E'(2), and E'(3) to the desired values. Furthermore, the adhesion between the cured protective film and the support sheet is suppressed, moderately improving the peelability of the support sheet. On the other hand, having the Tg of the acrylic resin below the upper limit improves the adhesion between the protective film and its cured form to the adherend.

[0061] If an acrylic resin has m constituent units (where m is an integer greater than or equal to 2), and each of the m monomers that derive these constituent units is sequentially assigned a unique number from 1 to m and named "monomer m", then the glass transition temperature (Tg) of the acrylic resin can be calculated using Fox's formula shown below.

[0062]

number

[0063]

number

[0064] The aforementioned Tg kValues described in polymer data handbooks, adhesives handbooks, Polymer Handbook, etc. can be used. For example, the Tg of a homopolymer of methyl acrylate k is 10 °C, and the Tg of a homopolymer of methyl methacrylate k is 105 °C, and the Tg of a homopolymer of 2-hydroxyethyl acrylate k is -15 °C, and the Tg of a homopolymer of glycidyl methacrylate k is 41 °C, and the Tg of a homopolymer of 2-ethylhexyl acrylate k is -70 °C, and the Tg of a homopolymer of acrylic acid k is 103 °C, and the Tg of a homopolymer of acrylonitrile k is 97 °C, and the Tg of a homopolymer of n-butyl acrylate k is -54 °C, and the Tg of a homopolymer of ethyl acrylate k is -24 °C.

[0065] Examples of acrylic resins include polymers of one or more (meth)acrylic acid esters; copolymers of two or more monomers selected from the above (meth)acrylic acid esters, (meth)acrylic acid, itaconic acid, vinyl acetate, acrylonitrile, styrene, N-methylolacrylamide, and the like.

[0066] Examples of the (meth)acrylic acid esters constituting the acrylic resin include 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, n-octyl (meth)acrylate, n-nonyl (meth)acrylate, and (meth Alkyl methacrylates such as isononyl acrylate, decyl methacrylate, undecyl methacrylate, dodecyl methacrylate (lauryl methacrylate), tridecyl methacrylate, tetradecyl methacrylate (myristyl methacrylate), pentadecyl methacrylate, hexadecyl methacrylate (palmityl methacrylate), heptadecyl methacrylate, octadecyl methacrylate (stearyl methacrylate), etc., in which the alkyl group constituting the alkyl ester has a chain structure with 1 to 18 carbon atoms; Cycloalkyl esters of (meth)acrylate such as isobornyl (meth)acrylate and dicyclopentanyl (meth)acrylate; (meth)acrylate aralkyl esters such as benzyl (meth)acrylate; (meth)acrylate dicyclopentenyl ester and other cycloalkenyl (meth)acrylates; (meth)acrylate cycloalkenyloxyalkyl esters such as (meth)acrylate dicyclopentenyloxyethyl ester; (meth)acrylimide; Glycidyl group-containing (meth)acrylic acid esters such as glycidyl (meth)acrylate; Hydroxymethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, and other hydroxyl group-containing (meth)acrylate esters; Examples include (meth)acrylic acid esters containing substituted amino groups, such as N-methylaminoethyl (meth)acrylate. Here, "substituted amino group" refers to a group having a structure in which one or two hydrogen atoms of an amino group are replaced by a group other than a hydrogen atom.

[0067] In this specification, "(meth)acrylic acid" is a concept that encompasses both "acrylic acid" and "methacrylic acid." The same applies to terms similar to (meth)acrylic acid; for example, "(meth)acryloyl group" is a concept that encompasses both "acryloyl group" and "methacryloyl group," and "(meth)acrylate" is a concept that encompasses both "acrylate" and "methacrylate."

[0068] The monomers that make up the acrylic resin may be just one type or two or more types, and if there are two or more types, their combination and ratio can be arbitrarily selected.

[0069] The acrylic resin may have functional groups that can bond with other compounds, such as vinyl groups, (meth)acryloyl groups, amino groups, hydroxyl groups, carboxyl groups, and isocyanate groups. The functional groups of the acrylic resin may be bonded to other compounds via a crosslinking agent (F) described later, or they may be directly bonded to other compounds without the crosslinking agent (F).

[0070] In the present invention, a thermoplastic resin other than acrylic resin (hereinafter sometimes simply referred to as "thermoplastic resin") may be used as the polymer component (A) alone without using acrylic resin, or in combination with acrylic resin. Using the thermoplastic resin may improve the peelability of the protective film from the support sheet, or make it easier for the protective film-forming film to conform to the uneven surface of the adherend.

[0071] The weight-average molecular weight of the thermoplastic resin is preferably 1,000 to 100,000, and more preferably 3,000 to 80,000.

[0072] The glass transition temperature (Tg) of the thermoplastic resin is preferably 0 to 70°C, and may be any of 0 to 50°C, 0 to 30°C, and 0 to 10°C, or any of 10 to 70°C and 20 to 70°C, or any of 10 to 50°C and 10 to 30°C.

[0073] Examples of the thermoplastic resins include polyester, polyurethane, phenoxy resin, polybutene, polybutadiene, and polystyrene.

[0074] The thermoplastic resin contained in composition (III) and the protective film-forming film may be one type or two or more types, and if there are two or more types, their combination and ratio can be arbitrarily selected.

[0075] In composition (III), the ratio of the polymer component (A) to the total content of all components other than the solvent is preferably 10 to 85% by mass, regardless of the type of polymer component (A), and may be, for example, 10 to 65% by mass, 10 to 45% by mass, and 10 to 30% by mass, or 30 to 85% by mass and 50 to 85% by mass. This means that, in a protective film-forming film, the ratio of the polymer component (A) content to the total mass of the protective film-forming film is preferably 10 to 85% by mass, regardless of the type of polymer component (A), and is equivalent to, for example, 10 to 65% by mass, 10 to 45% by mass, and 10 to 30% by mass, or 30 to 85% by mass and 50 to 85% by mass. This is based on the fact that, in the process of removing the solvent from a solvent-containing resin composition to form a resin film, the amount of components other than the solvent usually does not change, and the ratio of the contents of non-solvent components is the same in the resin composition and the resin film. Therefore, in this specification, hereafter, not limited to the case of protective film-forming films, the content of non-solvent components will only be described in the resin film obtained by removing the solvent from the resin composition.

[0076] Polymer component (A) may also correspond to thermosetting component (B). In the present invention, if composition (III) contains components that correspond to both polymer component (A) and thermosetting component (B), composition (III) is deemed to contain polymer component (A) and thermosetting component (B).

[0077] [Thermosetting component (B)] Thermosetting component (B) is a component for curing the protective film. The thermosetting component (B) contained in composition (III) and the protective film may be one type or two or more types, and if there are two or more types, their combination and ratio can be arbitrarily selected.

[0078] 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, thermosetting polyimide resin is a general term encompassing a polyimide precursor and a thermosetting polyimide, both of which form a polyimide resin through thermosetting.

[0079] (Epoxy thermosetting resin) An epoxy-based thermosetting resin consists, for example, of an epoxy resin (B1) and a thermosetting agent (B2). Furthermore, the epoxy-based thermosetting resin may not contain the thermosetting agent (B2) and may consist only of the epoxy resin (B1). The epoxy thermosetting resin contained in composition (III) and the protective film may be one type or two or more types, and if there are two or more types, their combination and ratio can be arbitrarily selected.

[0080] • Epoxy resin (B1) Examples of epoxy resins (B1) include well-known ones, such as polyfunctional epoxy resins, biphenyl compounds, bisphenol A diglycidyl ether and its hydrogenated products, orthocresol novolac epoxy resins, dicyclopentadiene type epoxy resins, biphenyl type epoxy resins, bisphenol A type epoxy resins, bisphenol F type epoxy resins, phenylene skeleton type epoxy resins, and other bifunctional or more epoxy compounds.

[0081] As the epoxy resin (B1), an epoxy resin having unsaturated hydrocarbon groups may be used.

[0082] The number-average molecular weight of the epoxy resin (B1) is not particularly limited, but from the viewpoint of the curability of the protective film-forming film, as well as the strength and heat resistance of the protective film, it is preferably 300 to 30000, more preferably 300 to 10000, and particularly preferably 300 to 3000. The epoxy equivalent of epoxy resin (B1) is preferably 100 to 1000 g / eq, and more preferably 150 to 950 g / eq.

[0083] Epoxy resin (B1) may be used alone or in combination of two or more types. When using two or more types in combination, the combination and ratio of these types can be arbitrarily selected.

[0084] • Thermosetting agent (B2) The thermosetting agent (B2) functions as a curing agent for the epoxy resin (B1). Examples of the thermosetting agent (B2) include compounds having two or more functional groups capable of reacting with epoxy groups in one molecule. Examples of the functional groups include phenolic hydroxyl groups, alcoholic hydroxyl groups, amino groups, carboxyl groups, and groups in which an acid group has been converted to an anhydride. It is preferable that the functional group is a phenolic hydroxyl group, an amino group, or a group in which an acid group has been converted to an anhydride, and more preferably a phenolic hydroxyl group or an amino group.

[0085] Examples of thermosetting agents (B2) that include phenolic curing agents having phenolic hydroxyl groups include polyfunctional phenolic resins, biphenols, novolac-type phenolic resins, dicyclopentadiene-type phenolic resins, and aralkyl-type phenolic resins. Examples of amine-based curing agents containing an amino group among the thermosetting agents (B2) include dicyandiamide.

[0086] The thermosetting agent (B2) may have an unsaturated hydrocarbon group.

[0087] When a phenolic curing agent is used as the thermosetting agent (B2), it is preferable that the thermosetting agent (B2) has a high softening point or glass transition temperature, as this improves the peelability of the protective film from the support sheet.

[0088] Among the thermosetting agents (B2), the number average molecular weight of the resin components, such as polyfunctional phenolic resins, novolac-type phenolic resins, dicyclopentadiene-type phenolic resins, and aralkyl-type phenolic resins, is preferably 300 to 30,000, more preferably 400 to 10,000, and particularly preferably 500 to 3,000. The molecular weight of the non-resin component of the thermosetting agent (B2), such as biphenol or dicyandiamide, is not particularly limited, but is preferably 60 to 500.

[0089] The thermosetting agent (B2) may be used alone or in combination of two or more types. When using two or more types in combination, the combination and ratio of these types can be arbitrarily selected.

[0090] When using a thermosetting agent (B2), the content of the thermosetting agent (B2) in composition (III) and the protective film is preferably 0.1 to 100 parts by mass, more preferably 0.5 to 50 parts by mass, per 100 parts by mass of epoxy resin (B1), and may be, for example, 0.5 to 25 parts by mass, 0.5 to 15 parts by mass, or 0.5 to 7 parts by mass. When the content of the thermosetting agent (B2) is above the lower limit, the curing of the protective film proceeds more easily. When the content of the thermosetting agent (B2) is below the upper limit, the moisture absorption rate of the protective film is reduced, and the reliability of the package obtained using the protective film is further improved.

[0091] In composition (III) and the protective film-forming film, the content of thermosetting component (B) is preferably 10 to 70 parts by mass, more preferably 15 to 60 parts by mass, and even more preferably 20 to 50 parts by mass, based on 100 parts by mass of the total content of polymer component (A) and thermosetting component (B). For example, it may be 25 to 40 parts by mass. When the content of thermosetting component (B) is within this range, for example, the adhesion between the cured product of the protective film-forming film and the support sheet is suppressed, and the peelability of the support sheet is improved. Here, when the thermosetting component (B) is an epoxy-based thermosetting resin, the "content of thermosetting component (B)" refers to the total content of epoxy resin (B1) and thermosetting agent (B2) when a thermosetting agent (B2) is used, and the content of epoxy resin (B1) when a thermosetting agent (B2) is not used.

[0092] [Curing accelerator (C)] Composition (III) and the protective film may contain a curing accelerator (C). The curing accelerator (C) is a component for adjusting the curing rate of composition (III). Preferred curing accelerators (C) include, for example, tertiary amines such as triethylenediamine, benzyldimethylamine, triethanolamine, dimethylaminoethanol, and tris(dimethylaminomethyl)phenol; imidazoles such as 2-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, and 2-phenyl-4-methyl-5-hydroxymethylimidazole (imidazoles in which one or more hydrogen atoms are substituted with groups other than hydrogen atoms); organophosphines such as tributylphosphine, diphenylphosphine, and triphenylphosphine (phosphines in which one or more hydrogen atoms are substituted with organic groups); and tetraphenylboron salts such as tetraphenylphosphonium tetraphenylborate and triphenylphosphine tetraphenylborate.

[0093] The curing accelerator (C) contained in composition (III) and the protective film-forming film may consist of only one type or two or more types, and if there are two or more types, their combination and ratio can be arbitrarily selected.

[0094] The curing accelerator (C) is preferably an imidazole, as this makes it easier to adjust the storage modulus E' (especially E'(1), E'(2), and E'(3)) of the first and second test specimens.

[0095] When a curing accelerator (C) is used, the content of the curing accelerator (C) in composition (III) and the protective film is preferably 1 to 13 parts by mass per 100 parts by mass of the content of the thermosetting component (B). For example, it may be 3 to 13 parts by mass, 6 to 13 parts by mass, or 9 to 13 parts by mass, or 1 to 10 parts by mass, or 1 to 7 parts by mass, or 3 to 10 parts by mass. When the content of the curing accelerator (C) is above the lower limit, the effect of using the curing accelerator (C) is more pronounced. When the content of the curing accelerator (C) is below the upper limit, for example, the effect of suppressing the migration and segregation of highly polar curing accelerator (C) towards the adhesive interface with the adherend in the protective film under high temperature and high humidity conditions is enhanced. As a result, the reliability of the protective film-coated chip obtained using the protective film-coating film is further improved.

[0096] [Filling material (D)] The composition (III) and the protective film-forming film preferably contain a filler (D). By containing a filler (D) in the protective film-forming film, the storage modulus E' (especially E'(1), E'(2), and E'(3)) of the first and second test specimens can be more easily adjusted. More specifically, by adjusting the content of the filler (D) in the protective film-forming film, the storage modulus E' (especially E'(1), E'(2), and E'(3)) of the first and second test specimens can be more easily adjusted. Furthermore, by containing a 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 protective film-coated chip obtained using the protective film-forming film can be further improved. In addition, by containing a 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.

[0097] The filler (D) may be either an organic filler or an inorganic filler, but an inorganic filler is preferred. Preferred inorganic fillers include, for example, powders such as silica, alumina, talc, calcium carbonate, titanium white, red iron oxide, silicon carbide, and boron nitride; beads formed from these inorganic fillers in a spherical shape; surface-modified products of these inorganic fillers; single-crystal fibers of these inorganic fillers; and glass fibers. Among these, the inorganic filler is preferably silica or alumina, and more preferably silica.

[0098] In a protective film-forming composition, in terms of improving the dispersibility of the filler (D) with respect to other components, the silica is preferably silica surface-modified with organic groups, more preferably silica surface-modified with vinyl groups, epoxy groups, phenyl groups, or methacrylic groups, and particularly preferably silica surface-modified with vinyl groups or epoxy groups.

[0099] In a protective film-forming composition, the average particle size of the filler (D) is preferably 0.02 to 2 μm, more preferably 0.05 to 0.7 μm, and particularly preferably 0.07 to 0.5 μm, in terms of improving the dispersibility of the filler (D) among other components.

[0100] In this specification, "average particle diameter" means the arithmetic mean ([sum of particle diameters of 100 particles in plan view] / 100) obtained by observing the particles in question using an electron microscope, randomly selecting 100 particles, and calculating their particle diameters 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 may be used as the particle diameter. For example, with respect to particles in a resin film, such as the filler (D) in a protective film, the average particle size can be determined by the method described above after the resin component has been removed by firing the resin film.

[0101] The composition (III) and the filler (D) contained in the protective film-forming film may consist of only one type or two or more types, and if there are two or more types, their combination and ratio can be arbitrarily selected.

[0102] When using filler (D), the ratio of filler (D) content to the total mass of the protective film forming film is preferably 20 to 70% by mass, and may be, for example, 30 to 70% by mass, 40 to 70% by mass, or 50 to 70% by mass. Having the ratio within this range makes it easier to adjust the storage modulus E' (especially E'(1), E'(2), and E'(3)) of the first and second test specimens.

[0103] [Coupling agent (E)] Composition (III) and the protective film-forming film may contain a coupling agent (E). By using a coupling agent (E) that has a functional group that can react with an inorganic compound or an organic compound, the adhesion of the protective film formed from the protective film-forming film to the adherend can be improved. Furthermore, by using a coupling agent (E), the water resistance of the protective film is improved without impairing its heat resistance.

[0104] The coupling agent (E) is preferably a compound having a functional group that can react with the functional groups of the polymer component (A), the thermosetting component (B), etc., and is more preferably a silane coupling agent.

[0105] Preferred silane coupling agents include, for example, 3-glycidyloxypropyltrimethoxysilane, 3-glycidyloxypropylmethyldiethoxysilane, 3-glycidyloxypropyltriethoxysilane, 3-glycidyloxymethyldiethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-(2-aminoethylamino)propyltrimethoxysilane, 3-(2- Examples include aminoethylamino)propylmethyldiethoxysilane, 3-(phenylamino)propyltrimethoxysilane, 3-anilinopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, bis(3-triethoxysilylpropyl)tetrasulfan, methyltrimethoxysilane, methyltriethoxysilane, vinyltrimethoxysilane, vinyltriacetoxysilane, and imidazolesilane.

[0106] The coupling agent (E) contained in composition (III) and the protective film-forming film may be one type or two or more types, and if there are two or more types, their combination and ratio can be arbitrarily selected.

[0107] When a coupling agent (E) is used, the content of the coupling agent (E) in composition (III) and protective film is preferably 0.03 to 10 parts by mass, more preferably 0.05 to 5 parts by mass, and particularly preferably 0.1 to 2 parts by mass, based on 100 parts by mass of the total content of polymer component (A) and thermosetting component (B). By having the content of the coupling agent (E) within this range, the chemical compatibility between the protective film-forming film and the adherend can be slightly controlled, making it easier to adjust the tackiness and peelability. On the other hand, when the content of the coupling agent (E) is above 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-forming film to the adherend, can be obtained more significantly. When the content of the coupling agent (E) is below the upper limit, outgassing is further suppressed.

[0108] [Crosslinking agent (F)] When polymer component (A) is a polymer having functional groups such as vinyl groups, (meth)acryloyl groups, amino groups, hydroxyl groups, carboxyl groups, and isocyanate groups that can bond with other compounds, such as the acrylic resin mentioned above, composition (III) and the protective film-forming film may contain a crosslinking agent (F). The crosslinking agent (F) is a component for crosslinking the functional groups in polymer component (A) with other compounds, and by crosslinking in this way, the adhesive strength and cohesive strength of the protective film-forming film can be adjusted.

[0109] Examples of crosslinking agents (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).

[0110] The crosslinking agent (F) contained in composition (III) and the protective film-forming film may be one type or two or more types, and if there are two or more types, their combination and ratio can be arbitrarily selected.

[0111] In terms of improving the long-term stability of the protective film-forming composition, it is preferable that composition (III) does not contain a crosslinking agent (F), or that the content of the crosslinking agent (F) in composition (III) is low, for example, less than 0.01 parts by mass per 100 parts by mass of polymer component (A). In contrast, when using a certain amount or more of the crosslinking agent (F), the content of the crosslinking agent (F) in composition (III) is preferably 0.01 to 20 parts by mass, more preferably 0.1 to 10 parts by mass, and particularly preferably 0.5 to 5 parts by mass, based on the content of polymer component (A) per 100 parts by mass. When the content of the crosslinking agent (F) is above the lower limit, the effect of using the crosslinking agent (F) is obtained more significantly. When the content of the crosslinking agent (F) is below the upper limit, the overuse of the crosslinking agent (F) is suppressed.

[0112] [Energy ray curable resin (G)] Composition (III) and the protective film may contain an energy-curable resin (G). The protective film contains an energy-curable resin (G), which allows its properties to be altered by irradiation with energy rays.

[0113] The energy-ray curable resin (G) is an energy-ray curable compound, or an oligomer or polymer (polymer) that can be considered to be synthesized from an energy-ray curable compound. Examples of the energy ray curable compound include compounds having at least one polymerizable double bond in the molecule, and acrylate compounds having a (meth)acryloyl group are preferred.

[0114] Examples of the aforementioned acrylate compounds include trimethylolpropane tri(meth)acrylate, tetramethylolmethane tetra(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol monohydroxypenta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, 1,4-butylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, and other chains. Examples include cyclic aliphatic skeleton-containing (meth)acrylates; cyclic aliphatic skeleton-containing (meth)acrylates such as dicyclopentanyl di(meth)acrylate; polyalkylene glycol (meth)acrylates such as polyethylene glycol di(meth)acrylate; oligoester (meth)acrylates; urethane (meth)acrylate oligomers; epoxy-modified (meth)acrylates; polyether (meth)acrylates other than the aforementioned polyalkylene glycol (meth)acrylates; and itaconic acid oligomers.

[0115] The weight-average molecular weight of the energy-ray curable compound is preferably 100 to 30,000, and more preferably 300 to 10,000.

[0116] The energy-curable compound used in the synthesis of the oligomer or polymer may be one type or two or more types, and if there are two or more types, their combination and ratio can be arbitrarily selected.

[0117] The energy-curable resin (G) contained in composition (III) and the protective film-forming film may be one type or two or more types, and if there are two or more types, their combination and ratio can be arbitrarily selected.

[0118] When using an energy-ray curable resin (G), the ratio of the content of the energy-ray curable resin (G) to the total mass of composition (III) is preferably 1 to 30% by mass, more preferably 5 to 25% by mass, and particularly preferably 10 to 20% by mass.

[0119] [Photopolymerization initiator (H)] If composition (III) and the protective film-forming film contain an energy-ray curable resin (G), they may also contain a photopolymerization initiator (H) to efficiently advance the polymerization reaction of the energy-ray curable resin (G).

[0120] Examples of photopolymerization initiators (H) in composition (III) include benzoin compounds such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzoin benzoic acid, benzoin methyl benzoate, and benzoin dimethyl ketal; acetophenone compounds such as acetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 2,2-dimethoxy-1,2-diphenylethane-1-one, 2-hydroxy-1-(4-(4-(2-hydroxy-2-methylpropionyl)benzyl)phenyl)-2-methylpropan-1-one, and 2-(dimethylamino)-1-(4-morpholinophenyl)-2-benzyl-1-butanone; and bis(2,4,6-trimethylbenzoyl)phenyl Examples include acylphosphine oxide compounds such as phosphine oxide and 2,4,6-trimethylbenzoyldiphenylphosphine oxide; sulfide compounds such as benzylphenyl sulfide and tetramethylthiuram monosulfide; α-ketol compounds such as 1-hydroxycyclohexylphenyl ketone; azo compounds such as azobisisobutyronitrile; titanocene compounds such as titanocene; thioxanthone compounds such as thioxanthone; peroxide compounds; diketone compounds such as diacetyl; benzyl; dibenzyl; benzophenone; 2,4-diethylthioxanthone; 1,2-diphenylmethane; 2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propanone; and quinone compounds such as 1-chloroanthraquinone and 2-chloroanthraquinone. Furthermore, examples of photopolymerization initiators (H) include photosensitizers such as amines.

[0121] The photopolymerization initiator (H) contained in composition (III) and the protective film-forming film may be one type or two or more types, and if there are two or more types, their combination and ratio can be arbitrarily selected.

[0122] When a photopolymerization initiator (H) is used, the content of the photopolymerization initiator (H) in composition (III) is preferably 0.1 to 20 parts by mass, more preferably 1 to 10 parts by mass, and particularly preferably 2 to 5 parts by mass, based on the content of 100 parts by mass of the energy ray curable resin (G).

[0123] [Coloring agent (I)] The composition (III) and the protective film preferably contain a colorant (I). By including a colorant (I), the light transmittance of the protective film and the protective film can be easily adjusted.

[0124] Examples of colorants (I) include known ones such as inorganic pigments, organic pigments, and organic dyes.

[0125] Examples of the aforementioned 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, pyririum-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, isoindolone-based dyes, quinophthalone-based dyes, pyrrole-based dyes, thioindigo-based dyes, metal complex-based dyes (metal complex salt dyes), dithiol metal complex-based dyes, indolephenol-based dyes, triallylmethane-based dyes, anthraquinone-based dyes, naphthol-based dyes, azomethine-based dyes, benzimidazolone-based dyes, pyranthrone-based dyes, and surene-based dyes.

[0126] Examples of the inorganic pigments mentioned above include carbon black, cobalt-based dyes, iron-based dyes, chromium-based dyes, titanium-based dyes, vanadium-based dyes, zirconium-based dyes, molybdenum-based dyes, ruthenium-based dyes, platinum-based dyes, ITO (indium tin oxide)-based dyes, ATO (antimony tin oxide)-based dyes, and the like.

[0127] The colorants (I) contained in composition (III) and the protective film may consist of only one type or two or more types, and if there are two or more types, their combination and ratio can be arbitrarily selected.

[0128] When using a coloring agent (I), the content of the coloring agent (I) in the protective film-forming film can be appropriately adjusted according to the purpose. For example, by adjusting the content of the coloring agent (I) in the protective film-forming film and thereby adjusting the light transmittance of the protective film-forming film, the visibility of the printed markings when laser printing is performed on the protective film-forming film or protective film can be adjusted. Furthermore, by adjusting the content of the coloring agent (I) in the protective film-forming film, it is possible to improve the aesthetic appearance of the protective film or make grinding marks on the back surface of the wafer less visible. Considering these points, the ratio of the content of the coloring agent (I) to the total mass of the protective film-forming film is preferably 0.1 to 10% by mass, more preferably 0.1 to 7.5% by mass, and particularly preferably 0.1 to 5% by mass. When the ratio is above the lower limit, the effect of using the coloring agent (I) is more pronounced. For example, when the protective film-forming film is peeled off from the adherend, it is easy to visually confirm whether or not any residue of the protective film-forming film remains on the adherend. By keeping the aforementioned ratio below the aforementioned upper limit, excessive use of coloring agent (I) is suppressed.

[0129] [General-purpose additive (J)] Composition (III) and the protective film-forming film may contain a general-purpose additive (J) within a range that does not impair the effects of the present invention. The general-purpose additive (J) may be any known additive and can be arbitrarily selected according to the purpose, and is not particularly limited, but preferred examples include plasticizers, antistatic agents, antioxidants, gettering agents, and ultraviolet absorbers.

[0130] The general-purpose additive (J) contained in composition (III) and the protective film-forming film may be one type or two or more types, and if there are two or more types, their combination and ratio can be arbitrarily selected. The content of 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.

[0131] [solvent] Composition (III) preferably further contains a solvent. Composition (III) containing a solvent has good handling properties. In this specification, unless otherwise specified, the term "solvent" includes not only substances that dissolve the target component but also dispersion media that disperse the target component.

[0132] 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 composition (III) may be one type or two or more types, and if there are two or more types, their combination and ratio can be arbitrarily selected.

[0133] More preferred solvents for composition (III) include, for example, methyl ethyl ketone, toluene, and ethyl acetate, as they allow for more uniform mixing of the components in composition (III).

[0134] The solvent content of composition (III) is not particularly limited and may be appropriately selected depending on the type of components other than the solvent.

[0135] <Method for producing protective film-forming composition (III)> Composition (III) is obtained by blending the components that constitute it. There are no particular restrictions on the order in which each component is added during formulation, and two or more components may be added simultaneously. The method of mixing each component during formulation is not particularly limited; it can be appropriately selected from known methods such as mixing by rotating a stirring bar or impeller, mixing using a mixer, or mixing by applying ultrasonic waves. The temperature and time during the addition and mixing of each component are not particularly limited as long as the components do not deteriorate, and can be adjusted as appropriate, but a temperature of 15 to 30°C is preferred.

[0136] ◎Examples of protective film-forming films Figure 1 is a schematic cross-sectional view showing an example of a protective film-forming film according to this embodiment. Note that, for convenience in order to make the features of the present invention easier to understand, the figures used in the following description may show enlarged versions of key parts, and the dimensional ratios of each component may not be the same as in reality.

[0137] The protective film-forming film 13 shown herein has a first release film 151 on one side (sometimes referred to as the "first side" in this specification) 13a and a second release film 152 on the other side (sometimes referred to as the "second side" in this specification) 13b opposite to the first side 13a. Such protective film-forming film 13 is suitable for storage, for example, in a roll form.

[0138] When the storage modulus E' of the first test specimen prepared using the protective film-forming film 13 is measured, its minimum value E'(1) is 45 MPa or less, and its maximum value E'(2) is 200 MPa or more. When the storage modulus E' of the second test specimen prepared using the protective film-forming film 13 was measured, its minimum value E'(3) was 500 MPa or higher.

[0139] The protective film-forming film 13 can be formed using the protective film-forming composition described above.

[0140] The first release film 151 and the second release film 152 may both be known types. The first release film 151 and the second release film 152 may be the same as each other, or they may be different from each other, for example, in that they require different peeling forces when peeled from the protective film forming film 13.

[0141] In Figure 1, the protective film-forming film 13 is formed when either the first release film 151 or the second release film 152 is removed, and the resulting exposed surface becomes the surface to be attached to the back surface of the semiconductor wafer (not shown). When a support sheet or dicing sheet, described later, is used, the remaining part of the first release film 151 and the second release film 152 is removed, and the resulting exposed surface of the protective film-forming film 13 becomes the surface to be attached to the support sheet or dicing sheet.

[0142] Figure 1 shows an example in which the release film is provided on both sides (first surface 13a and second surface 13b) of the protective film forming film 13. However, the release film may be provided on only one side of the protective film forming film 13, that is, only the first surface 13a or only the second surface 13b.

[0143] The protective film-forming film of this embodiment, when used in combination with a support sheet described later, can form a composite sheet for forming a protective film that can perform both protective film formation and dicing simultaneously. Such a composite sheet for forming a protective film will be described below.

[0144] ◇ Composite sheet for forming protective film A composite sheet for forming a protective film according to one embodiment of the present invention comprises a support sheet and a protective film forming film provided on one surface of the support sheet, wherein the protective film forming film is the protective film forming film according to the above-described embodiment of the present invention. The protective film-forming composite sheet of this embodiment can be attached to a target location on a workpiece (for example, the back surface of a wafer) by the protective film-forming film contained within it.

[0145] In this specification, as long as the laminated structure of the support sheet and the cured protective film is maintained even after the protective film has hardened, this laminated structure will be referred to as a "composite sheet for forming a protective film."

[0146] The following describes in detail each layer that constitutes the composite sheet for forming the protective film.

[0147] ◎Support sheet The support sheet may consist of one layer (single layer) or of two or more layers. If the support sheet consists of multiple layers, the constituent materials and thicknesses of these layers may be the same or different, and the combination of these layers is not particularly limited as long as it does not impair the effects of the present invention.

[0148] The support sheet may be transparent or opaque, and may be colored depending on the purpose. If the protective film is energy ray curable, the support sheet is preferably one that transmits energy rays.

[0149] Examples of support sheets include those comprising a base material and an adhesive layer provided on one surface of the base material; or those consisting only of the base material. When the support sheet includes an adhesive layer, the adhesive layer is positioned between the base material and the protective film in the case of a composite sheet for forming a protective film.

[0150] When a support sheet comprising a base material and an adhesive layer is used, the adhesion and peelability between the support sheet and the protective film-forming film can be easily adjusted in the composite sheet for forming the protective film. When a support sheet consisting only of the base material is used, a composite sheet for forming a protective film can be manufactured at a low cost.

[0151] Examples of the composite sheet for forming the protective film in this embodiment will be described below with reference to the drawings, according to each type of support sheet.

[0152] ◎ An example of a composite sheet for forming a protective film. Figure 2 is a schematic cross-sectional view showing an example of a composite sheet for forming a protective film according to this embodiment. In Figures 2 and beyond, components identical to those shown in previously explained figures are denoted by the same reference numerals, and their detailed explanations are omitted.

[0153] The protective film-forming composite sheet 101 shown herein comprises a support sheet 10 and a protective film-forming film 13 provided on one surface (sometimes referred to as the "first surface" in this specification) 10a of the support sheet 10. The support sheet 10 comprises a base material 11 and an adhesive layer 12 provided on one surface (first surface) 11a of the base material 11. In the protective film-forming composite sheet 101, the adhesive layer 12 is positioned between the base material 11 and the protective film-forming film 13. In other words, the protective film-forming composite sheet 101 is constructed by laminating a base material 11, an 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 adhesive layer 12 that is opposite to the substrate 11 side (which may be referred to as the "first surface" in this specification).

[0154] The protective film-forming composite sheet 101 further includes a jig adhesive layer 16 and a release film 15 on the protective film-forming film 13. In the protective film-forming composite sheet 101, a protective film-forming film 13 is laminated over the entire or nearly entire surface of the first surface 12a of the adhesive layer 12, and a jig adhesive layer 16 is laminated on a portion of the surface 13a of the protective film-forming film 13 opposite to the adhesive layer 12 (sometimes referred to as the "first surface" in this specification), i.e., in the area near the periphery. Furthermore, a release film 15 is laminated on the area of ​​the first surface 13a of the protective film-forming film 13 where the jig adhesive layer 16 is not laminated, and on the surface 16a of the jig adhesive layer 16 opposite to the protective film-forming film 13 (sometimes referred to as the "first surface" in this specification). A support sheet 10 is provided on the surface 13b of the protective film-forming film 13 opposite to the first surface 13a (sometimes referred to as the "second surface" in this specification).

[0155] In the case of the protective film-forming composite sheet 101, as well as in other cases of the protective film-forming composite sheet of this embodiment, the release film (for example, the release film 15 shown in Figure 2) can be of any configuration, and the protective film-forming composite sheet of this embodiment may or may not include a release film.

[0156] The adhesive layer 16 for the jig is used to fix the composite sheet 101 for forming a protective film to a jig such as a ring frame. The jig adhesive layer 16 may, for example, have a single-layer structure containing an adhesive component or a tack component, or it may have a multi-layer structure comprising a core sheet and layers containing an adhesive component or a tack component provided on both sides of the sheet.

[0157] The protective film-forming composite sheet 101 is used after the release film 15 has been removed, with the back surface of a semiconductor wafer attached to the first surface 13a of the protective film-forming film 13, and further, the first surface 16a of the jig adhesive layer 16 is attached to a jig such as a ring frame.

[0158] Figure 3 is a schematic cross-sectional view showing another example of the composite sheet for forming a protective film according to this embodiment. The protective film-forming composite sheet 102 shown here is the same as the protective film-forming composite sheet 101 shown in Figure 2, except that the size of the protective film-forming film is different and it does not have a jig adhesive layer 16.

[0159] More specifically, in the protective film-forming composite sheet 102, the protective film-forming film 23 is laminated on a portion of the first surface 12a of the adhesive layer 12, that is, on the central region in the width direction (left-right direction in Figure 3) of the adhesive layer 12. The release film 15 is laminated on the side of the protective film-forming film 23 opposite to the adhesive layer 12 (sometimes referred to as the "first surface" in this specification) 23a, and on the area of ​​the first surface 12a of the adhesive layer 12 where the protective film-forming film 23 is not laminated. A support sheet 10 is provided on the side of the protective film-forming film 23 opposite to the first surface 23a (sometimes referred to as the "second surface" in this specification) 23b.

[0160] The composite sheet for forming the protective film in this embodiment is not limited to those shown in Figures 2 and 3. Within the limits that do not impair the effects of the present invention, some components of those shown in Figures 2 and 3 may be modified or deleted, or other components may be added to those described herein.

[0161] Next, we will describe each layer that makes up the support sheet in more detail.

[0162] ○Base material The substrate is in the form of a sheet or film, and its constituent materials include, for example, various resins. The aforementioned resins include, for example, polyethylene such as low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), and high-density polyethylene (HDPE); polyolefins other than polyethylene such as polypropylene, polybutene, polybutadiene, polymethylpentene, and norbornene resin; ethylene-based copolymers such as ethylene-vinyl acetate copolymer, ethylene-(meth)acrylic acid copolymer, ethylene-(meth)acrylic acid ester copolymer, and ethylene-norbornene copolymer (polymers obtained using ethylene as a monomer); and vinyl chloride-based resins such as polyvinyl chloride and vinyl chloride copolymer (obtained using vinyl chloride as a monomer). Examples of materials include: modified resins; polystyrene; polycycloolefins; polyesters such as polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, polyethylene isophthalate, polyethylene-2,6-naphthalenedicarboxylate, and all aromatic polyesters having aromatic cyclic groups as all constituent units; copolymers of two or more of the above polyesters; poly(meth)acrylic acid esters; polyurethanes; polyurethane acrylates; polyimides; polyamides; polycarbonates; fluororesins; polyacetals; modified polyphenylene oxides; polyphenylene sulfides; polysulfones; polyether ketones, etc. Furthermore, the resin may also include, for example, a polymer alloy such as a mixture of the polyester and other resins. In the polymer alloy of polyester and other resins, it is preferable that the amount of the resin other than polyester is relatively small. Furthermore, examples of the resin include crosslinked resins obtained by crosslinking one or more of the resins exemplified so far, and modified resins such as ionomers using one or more of the resins exemplified so far. The aforementioned resin is preferably polypropylene or polybutylene terephthalate, as it offers excellent heat resistance.

[0163] The resin constituting the base material may consist of only one type, or two or more types. If there are two or more types, their combination and ratio can be arbitrarily selected.

[0164] The base material may consist of one layer (single layer) or of two or more layers. If it consists of multiple layers, these layers may be identical or different, and there are no particular limitations on the combination of these layers.

[0165] The thickness of the substrate is preferably 50 to 300 μm, and more preferably 60 to 100 μm. Having the substrate thickness within this range improves the flexibility of the composite sheet for protective film formation and its suitability for adhesion to the wafer. Here, "substrate thickness" refers to the total thickness of the substrate. For example, the thickness of a substrate consisting of multiple layers refers to the total thickness of all the layers that make up the substrate.

[0166] In addition to the main constituent materials such as the aforementioned resin, the base material may also contain various known additives such as fillers, colorants, antioxidants, organic lubricants, catalysts, and plasticizers.

[0167] The substrate may be transparent or opaque, and may be colored or have other layers deposited on it, depending on the purpose. If the protective film forming the film has energy ray curability, the substrate is preferably one that transmits energy rays.

[0168] The substrate may have its surface treated with sandblasting, solvent treatment, or other surface treatments to adjust its adhesion to the layer provided thereon (for example, an adhesive layer, a protective film-forming film, or the aforementioned other layer); oxidation treatments such as corona discharge treatment, electron beam irradiation treatment, plasma treatment, ozone / ultraviolet irradiation treatment, flame treatment, chromic acid treatment, or hot air treatment; lipophilic treatment; hydrophilic treatment, etc. The substrate may also have its surface treated with a primer.

[0169] The base material may contain components within a specific range (e.g., resin, etc.) to have adhesive properties on at least one surface.

[0170] The substrate can be manufactured by known methods. For example, a substrate containing a resin can be manufactured by molding a resin composition containing the resin.

[0171] ○ Adhesive layer The adhesive layer is in the form of a sheet or film and contains an adhesive. Examples of the adhesive include adhesive resins such as acrylic resin, urethane resin, rubber resin, silicone resin, epoxy resin, polyvinyl ether, polycarbonate, and ester resin.

[0172] The adhesive layer may consist of one layer (single layer) or of two or more layers. If it consists of multiple layers, these layers may be identical or different, and there are no particular limitations on the combination of these layers.

[0173] The thickness of the adhesive layer is not particularly limited, but is preferably 1 to 100 μm, more preferably 1 to 60 μm, and especially preferably 1 to 30 μm. Here, "thickness of the adhesive layer" refers to the total thickness of the adhesive layer. For example, the thickness of an adhesive layer consisting of multiple layers refers to the total thickness of all the layers that make up the adhesive layer.

[0174] The adhesive layer may be transparent or opaque, and may be colored depending on the purpose. If the protective film is energy ray curable, the adhesive layer is preferably one that allows energy rays to pass through.

[0175] The adhesive layer may be either energy-ray curable or non-energy-ray curable. The physical properties of the energy-ray curable adhesive layer can be adjusted before and after curing. For example, by curing the energy-ray curable adhesive layer before picking up the protective film-coated chip (described later), the protective film-coated chip can be picked up more easily.

[0176] In this specification, even after the energy-ray curable adhesive layer has been cured by energy rays, as long as the laminated structure of the substrate and the cured product of the energy-ray curable adhesive layer is maintained, this laminated structure will be referred to as a "support sheet".

[0177] An adhesive layer can be formed using an adhesive composition containing an adhesive. For example, an adhesive layer can be formed on the desired area by applying the adhesive composition to the surface on which the adhesive layer is to be formed and drying it as needed. The ratio of components that do not vaporize at room temperature in the adhesive composition is usually the same as the ratio of those components in the adhesive layer.

[0178] The adhesive composition can be coated and dried, for example, in the same manner as the coating and drying of the protective film-forming composition described above.

[0179] When the adhesive layer is energy ray curable, examples of energy ray curable adhesive compositions include: adhesive composition (I-1) containing a non-energy ray curable adhesive resin (I-1a) (hereinafter sometimes abbreviated as "adhesive resin (I-1a)") and an energy ray curable compound; adhesive composition (I-2) containing an energy ray curable adhesive resin (I-2a) (hereinafter sometimes abbreviated as "adhesive resin (I-2a)") in which an unsaturated group is introduced into the side chain of the non-energy ray curable adhesive resin (I-1a); and adhesive composition (I-3) containing the aforementioned adhesive resin (I-2a) and an energy ray curable compound.

[0180] When the adhesive layer is non-energy ray curable, examples of non-energy ray curable adhesive compositions include adhesive compositions (I-4) containing the non-energy ray curable adhesive resin (I-1a).

[0181] [Non-energy ray curable adhesive resin (I-1a)] The adhesive resin (I-1a) is preferably an acrylic resin. Examples of the acrylic resin include acrylic polymers having at least one structural unit derived from an alkyl (meth)acrylate ester.

[0182] The acrylic polymer preferably has, in addition to structural units derived from alkyl (meth)acrylate esters, structural units derived from functional group-containing monomers. Examples of the functional group-containing monomers include those in which the functional group reacts with a crosslinking agent described later to form a starting point for crosslinking. Examples of the functional group-containing monomers include hydroxyl group-containing monomers, carboxyl group-containing monomers, amino group-containing monomers, epoxy group-containing monomers, and the like.

[0183] The acrylic polymer may have structural units derived from other monomers, in addition to structural units derived from alkyl (meth)acrylate esters and structural units derived from functional group-containing monomers. The other monomers mentioned above are not particularly limited as long as they can be copolymerized with alkyl (meth)acrylate esters, etc. Examples of the other monomers mentioned above include styrene, α-methylstyrene, vinyltoluene, vinyl formate, vinyl acetate, acrylonitrile, and acrylamide.

[0184] In the aforementioned adhesive compositions (I-1), (I-2), (I-3), and (I-4) (hereinafter, these adhesive compositions will be collectively referred to as "adhesive compositions (I-1) to (I-4)"), the constituent units of the acrylic resin, such as the acrylic polymer, may consist of only one type or two or more types, and if there are two or more types, their combination and ratio can be arbitrarily selected.

[0185] The adhesive resin (I-1a) contained in adhesive composition (I-1) or adhesive composition (I-4) may be one type or two or more types, and if there are two or more types, the combination and ratio thereof can be arbitrarily selected.

[0186] In an adhesive layer formed from adhesive composition (I-1) or adhesive composition (I-4), the ratio of the content of adhesive resin (I-1a) to the total mass of the adhesive layer is preferably 5 to 99% by mass.

[0187] [Energy ray curable adhesive resin (I-2a)] The adhesive resin (I-2a) can be obtained, for example, by reacting a functional group in the adhesive resin (I-1a) with an unsaturated group-containing compound having an energy-ray polymerizable unsaturated group.

[0188] The aforementioned unsaturated group-containing compound is a compound that, in addition to the energy-ray polymerizable unsaturated group, has a group that can bond to the adhesive resin (I-1a) by reacting with a functional group in the adhesive resin (I-1a). Examples of the energy-ray polymerizable unsaturated group include a (meth)acryloyl group, a vinyl group (ethenyl group), an allyl group (2-propenyl group), and the (meth)acryloyl group, which is preferred. Examples of groups that can bond to functional groups in the adhesive resin (I-1a) include isocyanate groups and glycidyl groups that can bond to hydroxyl groups or amino groups, and hydroxyl groups and amino groups that can bond to carboxyl groups or epoxy groups.

[0189] Examples of the unsaturated group-containing compounds include (meth)acryloyloxyethyl isocyanate, (meth)acryloyl isocyanate, and glycidyl (meth)acrylate.

[0190] The adhesive resin (I-2a) contained in the adhesive composition (I-2) or (I-3) may be one type or two or more types, and if there are two or more types, the combination and ratio thereof can be arbitrarily selected.

[0191] In an adhesive layer formed from adhesive composition (I-2) or (I-3), the ratio of the content of adhesive resin (I-2a) to the total mass of the adhesive layer is preferably 5 to 99% by mass.

[0192] [Energy ray curable compound] The energy-ray curable compound contained in the adhesive composition (I-1) or (I-3) includes monomers or oligomers having energy-ray polymerizable unsaturated groups that can be cured by irradiation with energy rays.

[0193] Examples of monomers among energy-ray curable compounds include polyvalent (meth)acrylates such as trimethylolpropane tri(meth)acrylate, pentaerythritol (meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, 1,4-butylene glycol di(meth)acrylate, and 1,6-hexanediol (meth)acrylate; urethane (meth)acrylate; polyester (meth)acrylate; polyether (meth)acrylate; and epoxy (meth)acrylate. Examples of energy-ray curable compounds include oligomers, which are polymers of the monomers exemplified above.

[0194] The energy ray curable compound contained in the adhesive composition (I-1) or (I-3) may be one type or two or more types, and if there are two or more types, their combination and ratio can be arbitrarily selected.

[0195] In an adhesive layer formed from adhesive composition (I-1) or (I-3), the ratio of the content of the energy ray curable compound to the total mass of the adhesive layer is preferably 1 to 95% by mass.

[0196] [Crosslinking agent] When the acrylic polymer used as the adhesive resin (I-1a) has structural units derived from functional group-containing monomers in addition to structural units derived from alkyl (meth)acrylate, it is preferable that the adhesive composition (I-1) or (I-4) further contains a crosslinking agent. Furthermore, when using the acrylic polymer having functional group-containing monomer-derived structural units, similar to those in the tacky resin (I-1a), as the tacky resin (I-2a), the adhesive composition (I-2) or (I-3) may further contain a crosslinking agent.

[0197] The crosslinking agent reacts, for example, with the functional group to crosslink adhesive resins (I-1a) with each other or adhesive resins (I-2a) with each other. Examples of crosslinking agents include isocyanate-based crosslinking agents (crosslinking agents having an isocyanate group) such as tolylene diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, and adducts of these diisocyanates; epoxy-based crosslinking agents (crosslinking agents having a glycidyl group) such as ethylene glycol glycidyl ether; aziridine-based crosslinking agents (crosslinking agents having an aziridinyl group) such as hexa[1-(2-methyl)-aziridinyl]triphosphotriazine; metal chelate-based crosslinking agents (crosslinking agents having a metal chelate structure) such as aluminum chelate; and isocyanurate-based crosslinking agents (crosslinking agents having an isocyanuric acid skeleton).

[0198] The crosslinking agent contained in adhesive compositions (I-1) to (I-4) may be one type or two or more types, and if there are two or more types, their combination and ratio can be arbitrarily selected.

[0199] In the adhesive composition (I-1) or (I-4), the crosslinking agent content is preferably 0.01 to 50 parts by mass per 100 parts by mass of the adhesive resin (I-1a). In the adhesive composition (I-2) or (I-3), the crosslinking agent content is preferably 0.01 to 50 parts by mass per 100 parts by mass of the adhesive resin (I-2a).

[0200] [Photopolymerization initiator] The adhesive compositions (I-1), (I-2), and (I-3) (hereinafter collectively referred to as "adhesive compositions (I-1) to (I-3)") may further contain a photopolymerization initiator. Adhesive compositions (I-1) to (I-3) containing a photopolymerization initiator will undergo a sufficient curing reaction even when irradiated with relatively low-energy rays such as ultraviolet light.

[0201] Examples of the photopolymerization initiator include those similar to the photopolymerization initiator (H) described above.

[0202] The photopolymerization initiator contained in the adhesive compositions (I-1) to (I-3) may be one type or two or more types, and if there are two or more types, their combination and ratio can be arbitrarily selected.

[0203] In the adhesive composition (I-1), the content of the photopolymerization initiator is preferably 0.01 to 20 parts by mass per 100 parts by mass of the energy ray curable compound. In the adhesive composition (I-2), the content of the photopolymerization initiator is preferably 0.01 to 20 parts by mass per 100 parts by mass of the adhesive resin (I-2a). In the adhesive composition (I-3), the content of the photopolymerization initiator is preferably 0.01 to 20 parts by mass per 100 parts by mass of the total content of the adhesive resin (I-2a) and the energy ray curable compound.

[0204] [Other additives] The adhesive compositions (I-1) to (I-4) may contain other additives that do not fall under any of the above-mentioned components, as long as they do not impair the effects of the present invention. Other known additives include, for example, antistatic agents, antioxidants, plasticizers, fillers, rust inhibitors, colorants (pigments, dyes), sensitizers, tackifiers, reaction retarders, and crosslinking accelerators (catalysts). A reaction retarder is, for example, a component that suppresses the unintended crosslinking reaction that occurs in adhesive compositions (I-1) to (I-4) during storage due to the action of a catalyst mixed in them. Examples of reaction retarders include those that form a chelate complex by chelation with the catalyst, and more specifically, those that have two or more carbonyl groups (-C(=O)-) in one molecule.

[0205] The other additives contained in adhesive compositions (I-1) to (I-4) may be one type or two or more types, and if there are two or more types, their combination and ratio can be arbitrarily selected.

[0206] The content of other additives in adhesive compositions (I-1) to (I-4) is not particularly limited and may be appropriately selected depending on their type.

[0207] [solvent] Adhesive compositions (I-1) to (I-4) may contain a solvent. The presence of a solvent in adhesive compositions (I-1) to (I-4) improves their applicability to the surface to be coated.

[0208] The solvent is preferably an organic solvent, and examples of such organic solvents include ketones such as methyl ethyl ketone and acetone; esters (carboxylic acid esters) such as ethyl acetate; ethers such as tetrahydrofuran and dioxane; aliphatic hydrocarbons such as cyclohexane and n-hexane; aromatic hydrocarbons such as toluene and xylene; and alcohols such as 1-propanol and 2-propanol.

[0209] The solvent contained in adhesive compositions (I-1) to (I-4) may be one type or two or more types, and if there are two or more types, their combination and ratio can be arbitrarily selected.

[0210] The solvent content of adhesive compositions (I-1) to (I-4) is not particularly limited and may be adjusted as appropriate.

[0211] ○ Method for manufacturing adhesive compositions The adhesive composition can be manufactured in the same manner as the protective film-forming composition described earlier, except that the types of components used are different.

[0212] ◇Method for manufacturing a composite sheet for forming a protective film The composite sheet for forming the protective film can be manufactured by laminating the above-mentioned layers in corresponding positional relationships and, if necessary, adjusting the shape of some or all of the layers. The method for forming each layer is as described above.

[0213] For example, when manufacturing a support sheet and laminating an adhesive layer onto a substrate, the above-mentioned adhesive composition can be applied to the substrate and dried as necessary. Alternatively, an adhesive layer can be laminated onto a substrate by applying an adhesive composition to a release film, drying it as needed to form an adhesive layer on the release film, and then bonding the exposed surface of this adhesive layer to one surface of the substrate. In this case, it is preferable to apply the adhesive composition to the release surface of the release film. Furthermore, the release film in this case can be removed at either the manufacturing or usage stage of the protective film-forming composite sheet. Up to this point, we have used the example of laminating an adhesive layer on a substrate, but the method described above can also be applied to cases where other layers besides the adhesive layer are laminated on the substrate.

[0214] On the other hand, for example, when laminating a protective film-forming film on top of an adhesive layer already laminated on a substrate, it is possible to directly form the protective film-forming film by coating the adhesive layer with a protective film-forming composition. Layers other than the protective film-forming film can also be laminated on the adhesive layer in a similar manner using a composition for forming that layer. Thus, when forming a new layer (hereinafter abbreviated as "second layer") on top of any layer already laminated on a substrate (hereinafter abbreviated as "first layer") to form a continuous two-layer laminated structure (in other words, a laminated structure of the first and second layers), a method can be applied in which the composition for forming the second layer is coated onto the first layer and dried as necessary. However, it is preferable to pre-form the second layer on the release film using a composition for forming it, and then bond the exposed surface of the pre-formed second layer opposite to the side in contact with the release film to the exposed surface of the first layer to form a continuous two-layer laminated structure. In this case, it is preferable to coat the release treatment surface of the release film with the composition. The release film may be removed as needed after the laminated structure is formed. Here, we have given an example of laminating a protective film on an adhesive layer, but the target laminated structure can be arbitrarily selected, for example, when laminating a layer (film) other than a protective film on an adhesive layer.

[0215] Thus, since all layers other than the substrate that make up the composite sheet for forming a protective film can be pre-formed on a release film and laminated by bonding them to the surface of the target layer, the composite sheet for forming a protective film can be manufactured by appropriately selecting the layers to which such a process is employed as needed.

[0216] In addition, the composite sheet for forming a protective film is usually stored with a release film attached to the surface of the outermost layer (e.g., the protective film-forming film) opposite to the support sheet. Therefore, a composition for forming the outermost layer, such as a protective film-forming composition, is applied to this release film (preferably its release-treated surface), and dried as necessary to form the outermost layer on the release film. The remaining layers are then laminated on the exposed surface opposite to the side of this layer that is in contact with the release film, and the release film is not removed, resulting in a composite sheet for forming a protective film with a release film.

[0217] ◇Manufacturing method for semiconductor devices (Method of using protective film-forming film and composite sheet for protective film formation) The protective film-forming film and the composite sheet for forming the protective film can be used to manufacture the semiconductor chip with the protective film, and further to manufacture a semiconductor device using the same.

[0218] The semiconductor device manufacturing method of this embodiment includes: an attachment step of attaching one side of the protective film forming film, or the exposed side of the protective film forming film in the protective film forming composite sheet, to the back surface of a semiconductor wafer; a printing step after the attachment step, if the protective film forming composite sheet is used, laser printing is performed on the side of the protective film forming film in the protective film forming composite sheet that is on the support sheet side, or if the protective film forming film that is not part of the protective film forming composite sheet is used, laser printing is performed on the other side of the protective film forming film; and after the printing step, if the protective film forming composite sheet is used, the semiconductor wafer is divided into semiconductor chips on the support sheet in the protective film forming composite sheet, the protective film forming film is cut along the division point of the semiconductor wafer, and if the protective film forming film that is not part of the protective film forming composite sheet is used, a dicing sheet is printed on the other side of the protective film forming film. The process includes: a processing step of producing a semiconductor chip with a protective film, comprising the semiconductor chip and the protective film-forming film provided on the back surface of the semiconductor chip after cutting, by attaching the protective film to the semiconductor wafer on the dicing sheet and cutting the protective film-forming film along the division points of the semiconductor wafer; a pick-up step of separating and picking up the semiconductor chip with the protective film-forming film from the dicing sheet or support sheet after the processing step; a bonding step of bonding the semiconductor chip with the protective film-forming film to the circuit surface of a substrate by flip-chip connecting the protruding electrodes in the picked-up semiconductor chip with the protective film-forming film to the circuit surface of a substrate after the pick-up step; and a heat-curing step of forming a protective film by heat-curing the protective film-forming film in the semiconductor chip with the protective film-forming film after the bonding step.

[0219] The following describes the manufacturing method of semiconductor devices, with reference to diagrams. Figure 4 is a schematic cross-sectional view illustrating an example of a semiconductor device manufacturing method of this embodiment using a composite sheet for forming a protective film (sometimes referred to as "manufacturing method (1)" in this specification). Here, we will describe the case using the composite sheet 101 for forming a protective film shown in Figure 2.

[0220] <<Manufacturing method (1)>> <Pasting process> In the bonding step of the manufacturing method (1) described above, as shown in Figure 4(a), a semiconductor wafer 901 with a protective film is produced by bonding the protective film-forming film 13 from the protective film-forming composite sheet 101, from which the release film 15 has been removed, to the back surface 9b of the semiconductor wafer 9. The protective film-forming film 13 has its exposed first surface 13a bonded to the back surface 9b of the semiconductor wafer 9. In Figure 4(a), reference numeral 9a indicates the circuit side of the semiconductor wafer 9.

[0221] Note that in Figure 4, the circuit and protruding electrodes on the circuit surface of the semiconductor wafer or semiconductor chip are omitted from the illustration. This is also the case in subsequent figures.

[0222] The protective film 13 can be attached to the semiconductor wafer 9 by known methods, such as using a roll.

[0223] The conditions for attaching the protective film-forming film 13 to the semiconductor wafer 9 are not particularly limited. Typically, the temperature of the protective film-forming film 13 during attachment (attachment temperature) is preferably 20 to 100°C, and more preferably 65 to 75°C. The speed at which the protective film-forming film 13 is attached (attachment speed) is preferably 0.1 to 2 m / min, and the pressure applied to the protective film-forming film 13 during attachment (attachment pressure) is preferably 0.1 to 0.6 MPa.

[0224] Since the E'(1) of the first test specimen made from the protective film-forming film 13 is 45 MPa or less, the adhesion of the protective film-forming film 13 to the semiconductor wafer 9 is good during the bonding process. For example, in the semiconductor wafer 901 with the protective film-forming film attached, peeling of the protective film-forming film 13 from the semiconductor wafer 9 is suppressed even when it is cooled.

[0225] <Printing process> In the printing step following the bonding step of manufacturing method (1), as shown in Figure 4(b), laser printing is performed on the surface of the protective film forming film 13 in the protective film forming composite sheet 101 that is on the support sheet 10 side (i.e., the second surface 13b) by irradiating it with laser light R. Laser printing can be performed using known methods. For example, by setting the wavelength of the laser light R to 532 nm, the frequency of the laser light to 20-40 kHz, and the scan speed to 100-300 mm / s, good laser printing can be achieved by irradiating with the laser light R. Other wavelengths for the laser light R can also be selected.

[0226] Since the E'(2) of the first test specimen made from the protective film-forming film 13 is 200 MPa or higher, the printing is clearly formed on the protective film-forming film 13 after the printing process (more specifically, on the second surface 13b of the protective film-forming film 13).

[0227] <Processing process> After the printing step in the manufacturing method (1), in the processing step, on the support sheet 10 in the composite sheet 101 for forming a protective film, the semiconductor wafer 9 is divided into semiconductor chips 90, and along the dividing location of the semiconductor wafer 9, the protective film forming film 13 is cut. As a result, as shown in FIG. 4(c), a semiconductor chip 90 with a protective film forming film, which includes the semiconductor chip 90 and the cut protective film forming film 130 provided on the back surface 90b of the semiconductor chip 90, is produced, and a group 902 of semiconductor chips with protective film forming films, in which a plurality of semiconductor chips 913 with protective film forming films are aligned and fixed on the support sheet 10, is produced. In FIG. 4(c), reference numeral 130a indicates the first surface of the cut protective film forming film 130, which corresponds to the first surface 13a of the protective film forming film 13. Further, reference numeral 130b indicates the second surface of the cut protective film forming film 130, which corresponds to the second surface 13b of the protective film forming film 13. Further, reference numeral 90a indicates the circuit surface of the semiconductor chip 90, which corresponds to the circuit surface 9a of the semiconductor wafer 9.

[0228] In the processing step of the manufacturing method (1), for example, the division of the semiconductor wafer 9 and the cutting of the protective film forming film 13 may be performed simultaneously, or the cutting of the protective film forming film 13 may be performed after the division of the semiconductor wafer 9. In the manufacturing method (1), when the division of the semiconductor wafer and the cutting of the protective film forming film are continuously performed by the same operation without interruption regardless of the order thereof, it is regarded as if the division of the semiconductor wafer and the cutting of the protective film forming film are performed simultaneously.

[0229] Both the division of the semiconductor wafer 9 and the cutting of the protective film forming film 13 can be performed by known methods according to the order in which these are performed.

[0230] For example, by various dicing methods such as blade dicing using a blade, laser dicing using laser light irradiation, or water dicing by spraying water containing an abrasive, the semiconductor wafer 9 and the protective film forming film 13 can be cut simultaneously. Furthermore, by performing a so-called expansion, which involves pulling both the semiconductor wafer 9, which has a modified layer formed by stealth dicing (registered trademark) and has not been divided, and the protective film-forming film 13 in a direction parallel to their surfaces, the semiconductor wafer 9 can be divided and the protective film-forming film 13 can be cut simultaneously. Such expansion is preferably performed at low temperatures such as -20 to 5°C.

[0231] Stealth dicing (registered trademark) is a method described below. First, a location to be divided is set within the semiconductor wafer, and a laser beam is irradiated to focus on this location, thereby forming a modified layer within the semiconductor wafer. Unlike other parts of the semiconductor wafer, the modified layer is altered by the laser beam irradiation and has weakened strength. Therefore, when force is applied to the semiconductor wafer, cracks extending in both directions of the semiconductor wafer are generated in the modified layer inside the semiconductor wafer, becoming the starting point for the division of the semiconductor wafer. Next, force is applied to the semiconductor wafer to divide it at the location of the modified layer, and a semiconductor chip is manufactured.

[0232] <Pickup Process> After the processing step of manufacturing method (1), in the pickup step, as shown in Figure 4(d), the semiconductor chip 913 with the protective film is picked up by pulling it away from the support sheet 10. In the pickup step of manufacturing method (1), delamination occurs between the second surface 130b of the protective film forming film 130 in the semiconductor chip 913 with the protective film forming film and the first surface 12a of the adhesive layer 12 in the support sheet 10.

[0233] The semiconductor chip 913 with the protective film can be picked up by known methods. In particular, in manufacturing method (1), it is preferable to pick up the semiconductor chip 913 with the protective film by pushing it up with a pin from the side of the support sheet 10, through the support sheet 10 (interposed). Figure 4(d) further shows a case in which the semiconductor chip 913 with the protective film is separated in the direction of arrow P using a separation means 7 such as a vacuum collet.

[0234] When using pins, the number of pins may be just one, or it may be two or more. The pickup of the semiconductor chip 913 with the protective film is preferably performed at room temperature, or it may be performed at room temperature.

[0235] Since the E'(2) of the first test specimen made from the protective film-forming film 13 is 200 MPa or higher, the remaining pin thrust marks on the protective film-forming film 130 (more specifically, the second surface 130b of the protective film-forming film 130) after the pickup process are suppressed.

[0236] <Bonding process> In the bonding step following the pickup step of manufacturing method (1), as shown in Figure 4(e), the semiconductor chip 913 with protective film is bonded to the circuit surface 6a of the substrate 6 by flip-chip connecting the protruding electrodes in the picked-up semiconductor chip 913 with protective film to the circuit surface 6a of the substrate 6. The aforementioned protruding electrode is provided on the circuit surface 90a of the semiconductor chip 90 in the semiconductor chip 913 with a protective film forming film. In the bonding process, for example, a protruding electrode in the semiconductor chip 913 with a protective film is brought into contact with a connection pad provided on the circuit surface 6a of the substrate 6, thereby electrically connecting the protruding electrode and the connection pad on the circuit surface 6a, and thus enabling flip-chip connection. Note that in Figure 4(e), the circuit and other components of the substrate 6 are omitted from the illustration. Bonding the semiconductor chip 913 with a protective film to the circuit surface 6a can be performed by known methods.

[0237] <Thermosetting process> In the manufacturing method (1), after the bonding step, the thermal curing step involves thermal curing the protective film-forming film 130 in the semiconductor chip 913 with protective film-forming film to form a protective film 130' as shown in Figure 4(f). As a result, the semiconductor chip 913 with protective film-forming film becomes a semiconductor chip 913' comprising a semiconductor chip 90 and a protective film 130' provided on the back surface 90b of the semiconductor chip 90. In Figure 4(f), reference numeral 130b' indicates the second surface of the protective film 130', and corresponds to the second surface 130b of the protective film-forming film 130 after cutting.

[0238] In the thermosetting process, the heating temperature and heating time for the thermosetting of the protective film-forming film 130 are as described above.

[0239] Since the E'(3) of the second test specimen made from the protective film-forming film 13 is 500 MPa or higher, the protective film 130' has high protective performance and provides excellent protection for the semiconductor chip 90. Furthermore, because the E'(2) of the first test specimen made from the protective film-forming film 13 is 200 MPa or higher, the printing applied to the protective film-forming film 13 (more specifically, the second surface 13b of the protective film-forming film 13) during the printing process is clearly retained on the protective film 130' (more specifically, the second surface 130b' of the protective film 130').

[0240] In manufacturing method (1), a semiconductor package is fabricated using a substrate 6 equipped with a protective film-coated semiconductor chip 913' obtained by a thermosetting process, according to a known method, and the target semiconductor device can be manufactured by using this semiconductor package.

[0241] Up to this point, we have described a method for manufacturing a semiconductor device using a composite sheet for forming a protective film as manufacturing method (1). However, a semiconductor device can also be manufactured using a protective film-forming film that does not constitute a composite sheet, instead of the composite sheet for forming a protective film. Figure 5 is a schematic cross-sectional view illustrating an example of a manufacturing method for a semiconductor device according to this embodiment, in which a protective film-forming film that does not constitute a composite sheet for forming a protective film is used (sometimes referred to as "manufacturing method (2)" in this specification). Here, we will explain the case in which the protective film-forming film 13 shown in Figure 1 is used.

[0242] <<Manufacturing method (2)>> <Pasting process> In the bonding step of the manufacturing method (2) described above, as shown in Figure 5(a), a protective film-forming film 13 that does not constitute the protective film-forming composite sheet, more specifically, a protective film-forming film 13 from which the first release film 151 has been removed, is bonded to the back surface 9b of the semiconductor wafer 9 to produce a semiconductor wafer 901 with a protective film-forming film. This process is the same as the bonding process in manufacturing method (1), except that a protective film forming film 13 comprising a second release film 152 is used instead of a protective film forming film 13 comprising a support sheet 10, which constitutes the composite sheet 101 for forming a protective film.

[0243] The protective film-forming film 13 may be cut into a circular shape with a diameter the same as the semiconductor wafer 9 or 1 to 10 mm smaller than the wafer diameter before being attached to the back surface 9b of the semiconductor wafer 9. Doing so improves the workability during the attachment process and the workability of removing the second release film 152, which will be described later.

[0244] <Printing process> After the pasting step of the manufacturing method (2), in the printing step, as shown in FIG. 5(b), the second release film 152 is removed from the semiconductor wafer 901 with the protective film forming film, and the laser beam R is irradiated onto the newly formed exposed surface, that is, the second surface 13b of the protective film forming film 13, thereby performing laser printing on the surface. The semiconductor wafer 901 with the protective film forming film after laser printing is the same as the semiconductor wafer 901 with the protective film forming film after laser printing in the manufacturing method (1). Also in the manufacturing method (2), since E’(2) of the first test piece made from the protective film forming film 13 is 200 MPa or more, clear printing is formed on the protective film forming film 13 (more specifically, the second surface 13b of the protective film forming film 13) after the printing step.

[0245] <Dicing sheet pasting step> After the printing step of the manufacturing method (2), as shown in FIG. 5(c), a dicing sheet 80 is pasted on the second surface 13b of the protective film forming film 13 in the semiconductor wafer 901 with the protective film forming film. The dicing sheet 80 includes a base material 81 and an adhesive layer 82 provided on one surface thereof. In this step, the surface (which may be referred to as the "first surface" in this specification) 82a on the side opposite to the base material 81 side of the adhesive layer 82 is pasted on the second surface 13b of the protective film forming film 13. The first surface 82a of the adhesive layer 82 is the same as the first surface 80a of the dicing sheet 80. Thus, the manufacturing method (2) has a dicing sheet pasting step of pasting a dicing sheet on the surface of the protective film forming film in the semiconductor wafer with the protective film forming film, which is opposite to the semiconductor wafer side of the protective film forming film, between the printing step and the processing step.

[0246] The dicing sheet 80 may have the same configuration as the support sheet 10 in the composite sheet 101 for forming a protective film. Here, the case using dicing sheet 80 is shown, but in manufacturing method (2), other known dicing sheets besides dicing sheet 80 may be used, such as a dicing sheet made only of a base material.

[0247] The dicing sheet 80 can be attached to the protective film forming film 13 by a known method, for example, the same method used for attaching the protective film forming composite sheet 101 to the semiconductor wafer 9 in the attachment step of manufacturing method (1).

[0248] In manufacturing method (2), the processing step, pickup step, bonding step, and thermosetting step can be performed in the same manner as in manufacturing method (1), except that, from the dicing sheet attachment step onward, a semiconductor wafer 901 with a protective film-forming film equipped with a dicing sheet 80 is used instead of the semiconductor wafer 901 with a protective film-forming film equipped with a support sheet 10 as described above, and the target semiconductor device can be manufactured.

[0249] <Processing process> For example, in the processing step following the printing step (dicing sheet attachment step) of manufacturing method (2), as shown in Figure 5(d), the semiconductor wafer 9 is divided into semiconductor chips 90 on the dicing sheet 80, and the protective film forming film 13 is cut along the division points of the semiconductor wafer 9 to produce a semiconductor chip 913 with a protective film. The semiconductor chip 913 with a protective film obtained in this way is the same as the semiconductor chip 913 with a protective film in manufacturing method (1). In the processing step of manufacturing method (2), a group of semiconductor chips 903 with a protective film is produced, in which multiple semiconductor chips 913 with protective films are aligned and fixed on the dicing sheet 80 together with the semiconductor chip 913 with a protective film.

[0250] <Pickup Process> For example, after the processing step in manufacturing method (2), in the pickup step, as shown in Figure 5(e), the semiconductor chip 913 with the protective film is picked up by pulling it away from the dicing sheet 80. In the pickup step of manufacturing method (2), delamination occurs between the second surface 130b of the protective film forming film 130 in the semiconductor chip 913 with the protective film forming film and the first surface 82a of the adhesive layer 82 in the dicing sheet 80. In manufacturing method (2), the E'(2) of the first test specimen made from the protective film forming film 13 is 200 MPa or higher, which suppresses the retention of pin thrust marks on the protective film forming film 130 after the pickup process (more specifically, on the second surface 130b of the protective film forming film 130).

[0251] <Bonding process, heat curing process> The semiconductor chip 913 with protective film that is picked up in the pickup step of manufacturing method (2) is the same as the semiconductor chip 913 with protective film that is picked up in the pickup step of manufacturing method (1). Therefore, the bonding step and thermosetting step thereafter in manufacturing method (2) are the same as the bonding step and thermosetting step of manufacturing method (1), as shown in Figures 5(f) to 5(g). In manufacturing method (2), the E'(3) of the second test piece made from the protective film-forming film 13 is 500 MPa or higher, indicating that the protective film 130' has high protective performance and provides excellent protection for the semiconductor chip 90. Furthermore, in manufacturing method (2), since the E'(2) of the first test piece made from the protective film forming film 13 is 200 MPa or higher, the printing applied to the protective film forming film 13 (more specifically, the second surface 13b of the protective film forming film 13) in the printing process is clearly retained on the protective film 130' (more specifically, the second surface 130b' of the protective film 130').

[0252] <<Modified Method of Manufacturing Semiconductor Device>> The semiconductor device manufacturing method of this embodiment may include other steps that do not fall under any of the following categories: the attachment step, the printing step, the dicing sheet attachment step, the processing step, the pickup step, the bonding step, or the thermosetting step, as long as the effects of the present invention are not impaired. The aforementioned other steps can be arbitrarily selected depending on the purpose and are not particularly limited. The timing for performing the other processes can be appropriately selected depending on the content of those other processes.

[0253] Examples of other steps in the method for manufacturing the semiconductor device include a backgrind tape application step, in which a backgrind tape is applied to the circuit surface of the semiconductor wafer before the application step, and a backgrind tape removal step, in which the backgrind tape is removed from the circuit surface of the semiconductor wafer after the backgrind tape application step and before the application step. The backgrind tape may be a known type, and the application of the backgrind tape to the circuit surface of the semiconductor wafer and its removal from the circuit surface of the semiconductor wafer can be carried out by known methods.

[0254] In this specification, the term "attachment process" refers to the process of attaching the protective film-forming film, or the protective film-forming film in the protective film-forming composite sheet, to the back surface of a semiconductor wafer, which does not fall under either the "dicing sheet attachment process" or the "backgrind tape attachment process."

[0255] Up to this point, we have described the case in which the protective film-forming composite sheet 101 shown in Figure 2 is used as the manufacturing method (1) above. However, in the manufacturing method of the semiconductor device of this embodiment, other protective film-forming composite sheets, such as the protective film-forming composite sheet 102 shown in Figure 3, may also be used. When using the aforementioned other protective film-forming composite sheet, the method for manufacturing the semiconductor device of this embodiment may include the aforementioned other steps, which may be performed at any given time, based on the differences in the configuration between the aforementioned other protective film-forming composite sheet and the protective film-forming composite sheet 101 shown in Figure 2. [Examples]

[0256] The present invention will be described in more detail below with reference to specific examples. However, the present invention is not limited in any way to the examples shown below.

[0257] <Raw materials for resin manufacturing> The full names of the resin manufacturing raw materials, which are abbreviated in this example and comparative example, are shown below. MA: Methyl acrylate HEA: 2-hydroxyethyl acrylate ACrMO:4-Acryloylmorpholine

[0258] <Raw materials for manufacturing protective film-forming compositions> The raw materials used in the production of the protective film-forming composition are listed below. [Polymer component (A)] (A)-1: Acrylic polymer obtained by copolymerizing MA (85 parts by mass) and HEA (15 parts by mass) (weight-average molecular weight 400,000, glass transition temperature 6°C) (A)-2: Acrylic polymer obtained by copolymerizing MA (60 parts by mass), ACrMO (25 parts by mass), and HEA (15 parts by mass) (weight-average molecular weight 200,000, glass transition temperature 29°C) [Epoxy resin (B1)] (B1)-1: Bisphenol A type epoxy resin (Mitsubishi Chemical Corporation "jER828", epoxy equivalent 184~194 g / eq) [Thermosetting agent (B2)] (B2)-1: Dicyandiamide (thermally active latent epoxy resin curing agent, "DICY7" manufactured by Mitsubishi Chemical Corporation) [Curing accelerator (C)] (C)-1: Imidazole-based curing accelerator (a 1:1 mixture of 1,3,5-triazine-2,4,6(1H,3H,5H)-trione and 6-2-(2-methyl-1H-imidazole-1-yl)ethyl-1,3,5-triazine-2,4-diamine, manufactured by Shikoku Chemicals Co., Ltd., "Curesol (registered trademark) 2MAOK-PW") (C)-2:2-phenyl-4,5-dihydroxymethylimidazole (Shikoku Chemicals Co., Ltd. "Curesol (registered trademark) 2PHZ") (C)-3:2-Undecylimidazole (Shikoku Chemicals Co., Ltd. "Curesol (registered trademark) C11Z") [Filling material (D)] (D)-1: Silica filler (Admatex "SC105G-MMQ", spherical silica filler surface modified with vinyl groups, average particle size 0.3 μm) [Coloring agent (I)] (I)-1: Organic black pigment (Dainichi Seika Kogyo Co., Ltd. "6377 Black")

[0259] [Example 1] <<Manufacturing of protective film-forming film>> <Manufacturing of protective film-forming composition (III)> Polymer component (A)-1 (25.9 parts by mass), epoxy resin (B1)-1 (10 parts by mass), curing accelerator (C)-1 (1.1 parts by mass), filler (D)-1 (60 parts by mass), and colorant (I)-1 (3 parts by mass) were dissolved or dispersed in methyl ethyl ketone and stirred at 23°C to obtain thermosetting protective film-forming composition (III)-1, in which the total concentration of all components other than the solvent was 60% by mass. The amounts of components other than methyl ethyl ketone shown herein are all amounts of the target product excluding the solvent.

[0260] <Manufacturing of protective film-forming films> A release film (second release film, Lintec Corporation's "SP-PET502150", 50 μm thick) made of polyethylene terephthalate film, in which one side was treated with silicone for release, was used. The protective film-forming composition (III)-1 obtained above was applied to the release-treated surface, and the film was dried at 100°C for 2 minutes to produce a thermosetting protective film-forming film with a thickness of 25 μm.

[0261] Furthermore, a protective film-forming film with a release film was manufactured by laminating the release-treated surface of a release film (first release film, Lintec Corporation's "SP-PET381031", thickness 38 μm) to the exposed surface of the obtained protective film-forming film that does not have a second release film, under the conditions of a lamination speed of 2 m / min, a lamination temperature of 60°C, and a lamination pressure of 0.5 MPa, thereby comprising a protective film-forming film, a first release film provided on one side of the protective film-forming film, and a second release film provided on the other side of the protective film-forming film.

[0262] <<Evaluation of protective film-forming film>> <Measurement of the minimum and maximum storage modulus E'(1) and E'(2) of the first test specimen> Using the eight protective film-forming films with release films obtained above, the exposed surfaces of the protective film-forming films were sequentially bonded together while removing either the first or second release film, thereby creating a laminate in which the second release film, the eight protective film-forming films (total thickness 200 μm), and the second release film were stacked in this order. From this laminate, sections with a width of 4 mm and a length of 30 mm were cut out. Next, the two outermost second release films were removed from this section, and the resulting specimen was designated as the first test specimen. Next, using a dynamic viscoelasticity measuring device (Rheovibron DDV-II-EP1, manufactured by Orientec Co., Ltd.), the storage modulus E' of the first test specimen was measured using the tensile method (tensile mode) under the following measurement conditions: chuck distance of 20 mm, frequency of 11 Hz, heating rate of 3 °C / min, and constant heating rate, in the temperature range from -20 °C to 150 °C. The minimum value E'(1) and maximum value E'(2) in the temperature range of 23 to 70 °C are shown in Table 1.

[0263] <<Evaluation of protective film-forming film>> <Measurement of the minimum value E'(3) of the storage modulus E' of the second test specimen> Similarly to the above, a laminate was prepared by stacking the second release film, eight protective film-forming films (total thickness 200 μm), and the second release film in this order. Then, a section with a width of 5 mm and a length of 30 mm was cut from this laminate. This section was heat-cured by heating at 180°C for 5 minutes. After heat curing, the two outermost second release films were removed from the section, and the resulting specimen was designated as the second test specimen. Next, using a dynamic viscoelasticity measuring device (DMA Q800, manufactured by T.A. Instruments), the storage modulus E' of the second test specimen was measured using the tensile method (tensile mode) under the following measurement conditions: chuck distance of 20 mm, frequency of 11 Hz, heating rate of 3 °C / min, and constant heating rate, in the temperature range from -60 °C to 350 °C. The minimum value E'(3) in the temperature range of 23 to 70 °C is shown in Table 1.

[0264] <Evaluation of the adhesion properties of protective film-forming films to semiconductor wafers> A silicon wafer with a protective film was fabricated by applying the protective film obtained above to the #2000 polished surface of a 6-inch silicon wafer (350 μm thick) using a film laminator (FIRST LAMINATOR VA-400, manufactured by Taisei Laminator Co., Ltd.) with a rubber roll heated to 70°C, under conditions of application speed of 0.3 m / min and application pressure of 0.3 MPa. The application temperature of the protective film was 70°C. The adhesion of the protective film to the silicon wafer at this time was evaluated according to the following criteria. The results are shown in Table 1. (Evaluation Criteria) A: The protective film that forms the protective layer adheres to the silicon wafer without peeling off after cooling, demonstrating excellent adhesion of the protective film to the silicon wafer. B: At least a portion of the protective film after cooling peels off from the silicon wafer, indicating poor adhesion of the protective film to the silicon wafer.

[0265] <Evaluation of print retention on protective film> On the silicon wafer with the protective film-forming film obtained above, the side of the protective film-forming film opposite to the silicon wafer side (exposed side) was laser printed using a laser printing device (EO Technics "CSM300M") at room temperature (23°C). At this time, the wavelength of the laser light was set to 532 nm, the frequency of the laser light to 40 kHz, and the scan speed to 300 mm / s, and the string of characters "ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789" was printed. The character size was 0.3 mm x 0.2 mm per character. Next, the silicon wafer with the protective film attached after laser printing was heated at 180°C for 5 minutes to heat-cur the protective film and form a protective film. The printing (characters) in this protective film originating from the protective film was visually observed, and the retention of the printing in the protective film was evaluated according to the following criteria. The results are shown in Table 1. (Evaluation Criteria) A: The printing is clear and easily visible, and the protective film has high print retention. B: The printing is slightly blurred and difficult to see, and the protective film does not retain the printing well. C: The printing is unclear and illegible, and the protective film has extremely poor print retention.

[0266] <Evaluation of the effect of the protective film on suppressing the persistence of pin indentations> A silicon wafer with a protective film attached was fabricated using the same method as in the "Evaluation of the adherence of protective film-forming films to semiconductor wafers" described above. Next, a dicing sheet (Lintec's "Adwill D-676H") was attached to the side of the protective film-forming film on the silicon wafer with the protective film-forming film that was opposite to the silicon wafer side (the exposed side), thereby creating a laminate of the dicing sheet and the silicon wafer with the protective film-forming film. Next, using a dicing apparatus (DISCO "DFD6362") and a dicing blade (ZH05-SD2000-N1-90CC), the silicon wafer and protective film-forming film in the laminate obtained above were diced under the conditions of a dicing blade travel speed of 50 mm / s, a dicing blade rotation speed of 30,000 rpm, and a height of 60 μm. This produced a group of silicon chips with protective film-forming films, each consisting of a silicon chip measuring 5 mm x 5 mm (thickness 350 μm) and a protective film-forming film of the same size (2 mm x 5 mm) (thickness 25 μm) provided on its #2000 polished surface, which were aligned and fixed on a dicing sheet.

[0267] Next, ultraviolet light with a wavelength of 365 nm is applied to the dicing sheet from the outside of the silicon chip group with the protective film-forming film, at an irradiance of 230 mW / cm². 2 , light intensity 190mJ / cm 2 The irradiation was performed under the following conditions. Next, at room temperature (23°C), a die bonder (Canon Machinery's "BESTEM-D510") was used to sequentially pick up five silicon chips with protective film-forming films from the dicing sheet after UV irradiation by using a single pin to push up the silicon chips with protective film-forming films from the dicing sheet side through the dicing sheet. At this time, the pin used had a radius of curvature of 250 μm at the tip of the pushing part.

[0268] Next, the exposed surface of the protective film (the surface to which the dicing sheet was attached) of the protective film in the five selected silicon chips was visually observed, and then observed using an optical microscope to evaluate the effect of the protective film on suppressing the remaining pin indentation marks according to the following criteria. The results are shown in Table 1. (Evaluation Criteria) A: No pin indentations were observed through both visual inspection and observation using an optical microscope, indicating a high effectiveness in suppressing the persistence of pin indentations by the protective film-forming film. B: Visual observation did not reveal any pin indentations, but observation using an optical microscope revealed pin indentations, indicating that the protective film's ability to suppress the persistence of pin indentations is inferior to that of A. C: Pin thrust marks were observed both visually and using an optical microscope, indicating that the protective film formation film has a low effect in suppressing the persistence of pin thrust marks.

[0269] <Evaluation of the protective performance of the protective film> Similarly to the above, a laminate was fabricated by stacking a second release film, eight protective film-forming films (total thickness 200 μm), and a second release film in this order. Next, the laminate was heated at 180°C for 5 minutes to heat-cur all of the protective film-forming films within the laminate. Next, a 10mm x 10mm section was cut from the laminate after heating (after the protective film had been heat-cured). The two outermost second release films were removed from this section to obtain the third test specimen. Ten of these third test specimens were prepared. Next, using a precision universal testing machine (Shimadzu Corporation's "Autograph AG-IS"), the three-point bending strength of 10 third test specimens was measured using a wedge-shaped bending jig with a width of 4 mm, under the conditions of a support distance of 6 mm and a bending jig speed of 0.01 m / min. The average value of these measurements was adopted as the bending strength of the protective film. Furthermore, the stress was calculated by dividing this bending strength by the cross-sectional area of ​​the third test specimen, and the protective performance of the protective film was evaluated based on this stress according to the following criteria. The results are shown in Table 1. (Evaluation Criteria) A: Stress is 15 mN / mm 2 In summary, the protective film offers high protective performance. B: Stress is 6 mN / mm 2 More than 15mN / mm 2 It is less than A, and the protective performance of the protective film is inferior to that of case A. C: Stress is 6 mN / mm 2 It is less than [a certain value], and the protective performance of the protective film is low.

[0270] <<Manufacturing and Evaluation of Protective Film Forming Films>> [Example 2] Polymer component (A)-2 (25.9 parts by mass), epoxy resin (B1)-1 (10 parts by mass), thermosetting agent (B2)-1 (0.55 parts by mass), curing accelerator (C)-2 (0.55 parts by mass), filler (D)-1 (60 parts by mass), and colorant (I)-1 (3 parts by mass) were dissolved or dispersed in methyl ethyl ketone and stirred at 23°C to obtain thermosetting protective film-forming composition (III)-2, in which the total concentration of all components other than the solvent was 60% by mass. The amounts of components other than methyl ethyl ketone shown here are all amounts of the target product excluding the solvent.

[0271] A protective film-forming film was manufactured and evaluated in the same manner as in Example 1, except that protective film-forming composition (III)-2 obtained above was used instead of protective film-forming composition (III)-1. The results are shown in Table 1.

[0272] [Example 3, Comparative Examples 1-3] The protective film-forming film was manufactured and evaluated using the same method as in Example 1, except that the types of components were changed so that the components and their contents of the protective film-forming film were as shown in Table 1. The results are shown in Table 1.

[0273] [Table 1]

[0274] As is clear from the results above, in Examples 1 to 3, when the silicon chip with the protective film was picked up by pin thrust, the effect of suppressing the remaining pin thrust marks on the protective film was high. In addition, in Examples 1 to 3, when the protective film was formed, the retention of the printing on the protective film was high. In Examples 1-3, the E'(2) of the first test specimen was 280 MPa or higher.

[0275] In Examples 1 to 3, the protective film was easily attached to the semiconductor wafer. In Examples 1 to 3, the E'(1) of the first test specimen was 40 MPa or less.

[0276] In Examples 1-3, the protective performance of the protective film was high. In Examples 1-3, the E'(3) of the second test specimen was 5402 MPa or higher.

[0277] In contrast, in Comparative Example 1, the retention of the print on the protective film was significantly low, and the effect of suppressing the remaining pin push-up marks on the protective film-forming film was low. Furthermore, in Comparative Example 1, the protective performance of the protective film was also somewhat inferior. In Comparative Example 1, both E'(2) of the first test specimen and E'(3) of the second test specimen were low.

[0278] In Comparative Example 2, the adhesion of the protective film to the semiconductor wafer was poor. In Comparative Example 2, the E'(1) value of the first test specimen was high.

[0279] In Comparative Example 3, the retention of the print on the protective film was significantly low, and the effect of suppressing the remaining pin thrust marks on the protective film-forming film was low. Furthermore, in Comparative Example 3, the protective performance of the protective film was also low. In Comparative Example 3, both E'(2) of the first test specimen and E'(3) of the second test specimen were low. [Industrial applicability]

[0280] This invention can be used in the manufacture of semiconductor devices. [Explanation of Symbols]

[0281] 10...Support sheet, 10a...One side of the support sheet (first side), 11...Base material, 12. Adhesive layer, 13,23...Protective film forming film, 13a,23a...One side of the protective film forming film (first side), 13b,23b...The side of the protective film forming film facing the support sheet (second side), 130... Protective film formed after cutting, 130'...protective film, 101, 102... Composite sheets for forming protective films, 6... circuit board, 6a... circuit side of circuit board, 80 dicing sheets, 9... Semiconductor wafer, 9a... Circuit side of semiconductor wafer, 9b... Back side of semiconductor wafer, 90... Semiconductor chips, 913... Semiconductor chip with protective film

Claims

1. A thermosetting protective film, In a laminate of multiple protective film-forming films, a first test piece with a width of 4 mm is held at two locations with a 20 mm gap between them, and the storage modulus E' of the first test piece is measured while heating the first test piece from -20°C to 150°C under the conditions of a tensile mode, a frequency of 11 Hz, a heating rate of 3°C / min, and constant heating, and the minimum value E'(1) of the storage modulus E' in the temperature range of 23 to 70°C is 40 MPa or less, and the maximum value E'(2) of the storage modulus E' in the temperature range of 23 to 70°C is 280 MPa or more. A protective film-forming film is a cured product obtained by thermally curing a laminate of multiple protective film-forming films, wherein a second test piece with a width of 5 mm is held at two locations with a 20 mm gap between them, and the storage modulus E' of the second test piece is measured while heating the second test piece from -60°C to 350°C under the conditions of a tensile mode, a frequency of 11 Hz, a heating rate of 3°C / min, and constant heating, and the minimum value E'(3) of the storage modulus E' in the temperature range of 23 to 70°C is 2897 MPa or higher.

2. The protective film forming film according to claim 1, wherein the protective film forming film contains a curing accelerator (C).

3. The protective film forming film according to claim 1 or 2, wherein the protective film forming film is a single layer.

4. It comprises a support sheet and a protective film-forming film provided on one surface of the support sheet, A composite sheet for forming a protective film, wherein the protective film forming film is the protective film forming film according to any one of claims 1 to 3.

5. A method for manufacturing a semiconductor device, The manufacturing method includes a bonding step of bonding one side of the protective film forming film described in any one of claims 1 to 3, or the exposed side of the protective film forming film in the protective film forming composite sheet described in claim 4, to the back surface of a semiconductor wafer. After the aforementioned bonding step, if the protective film-forming composite sheet is used, a printing step is performed in which laser printing is performed on the side of the protective film-forming film in the protective film-forming composite sheet that is on the side of the support sheet, and if the protective film-forming film that is not part of the protective film-forming composite sheet is used, laser printing is performed on the other side of the protective film-forming film. If the protective film-forming composite sheet is used after the aforementioned bonding step, the semiconductor wafer is divided into semiconductor chips on the support sheet in the protective film-forming composite sheet, and the protective film-forming film is cut along the divided portions of the semiconductor wafer. If the protective film-forming film that does not constitute the protective film-forming composite sheet is used, a dicing sheet is attached to the other side of the protective film-forming film, and then the semiconductor wafer is divided into semiconductor chips on the dicing sheet, and the protective film-forming film is cut along the divided portions of the semiconductor wafer. This process is used to produce a semiconductor chip with a protective film-forming film, comprising the semiconductor chip and the cut protective film-forming film provided on the back surface of the semiconductor chip. After the processing step, a pickup step is performed to separate and pick up the semiconductor chip with the protective film-forming film from the dicing sheet or support sheet. Following the pickup step, a bonding step is performed in which the protruding electrodes in the semiconductor chip with the protective film that was picked up are flip-chip connected to the circuit surface of the substrate, thereby bonding the semiconductor chip with the protective film to the circuit surface. A method for manufacturing a semiconductor device, comprising: a thermal curing step after the bonding step, in which the protective film forming film in the semiconductor chip with the protective film forming film is thermally cured to form a protective film.

6. A protective film-forming film is used to form a protective film on the back surface of a semiconductor wafer, opposite to the circuit surface, and to form a protective film on the back surface of a semiconductor chip obtained by dividing the semiconductor wafer. Use of a protective film-forming film, wherein the protective film-forming film is the protective film-forming film described in any one of claims 1 to 3.

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