Temporary protective film for semiconductor device manufacturing and method for manufacturing semiconductor device

Abstract

To provide a temporary protective film that has excellent adhesive strength at room temperature and can suppress remaining on an adherend when peeled off.SOLUTION: A temporary protective film for semiconductor device manufacturing includes a support film and an adhesive layer provided on the support film, the adhesive layer includes a polymer containing alkyl (meth)acrylate, (meth)acryloylmorpholine, and a monomer having a crosslinkable group as a monomer unit, and a crosslinking agent capable of crosslinking with the crosslinkable group, and the content of (meth)acryloylmorpholine is 7 mass% or more based on the total amount of monomer units in the polymer.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a temporary protection film for manufacturing semiconductor devices and a method for manufacturing semiconductor devices.

Background Art

[0002] In a semiconductor package, a structure may be adopted in which a sealing layer is formed only on the semiconductor element side of a lead frame and the back surface of the lead frame is exposed. In manufacturing a semiconductor package having this structure, there is a risk that the sealing material may wrap around the back surface of the lead frame when forming the sealing layer. To prevent this, a method of attaching a temporary protection film to the back surface of the lead frame is known (Patent Document 1). The temporary protection film is peeled off from the lead frame after the sealing layer is formed.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a temporary protection film, while having excellent adhesive force that can be attached to an adherend such as a lead frame at room temperature (for example, 25°C), it is desirable that when peeling the temporary protection film from the adherend, the adhesive component of the temporary protection film does not remain on the adherend. However, it is not always easy to achieve both of these.

[0005] Therefore, an aspect of the present invention aims to provide a temporary protection film that has excellent adhesive force at room temperature and can suppress residue on the adherend during peeling.

Means for Solving the Problems

[0006] The inventors investigated the use of a polymer containing alkyl (meth)acrylate, (meth)acryloylmorpholine, and a monomer having a crosslinkable group as monomer units in the adhesive layer of a temporary protective film. As a result, it was found that when the (meth)acryloylmorpholine content is above a certain amount, it is possible to achieve both excellent adhesive strength at room temperature and suppression of residue generation on the adherend.

[0007] The present invention includes the following aspects. [1] A temporary protective film for semiconductor device manufacturing, comprising a support film and an adhesive layer provided on the support film, wherein the adhesive layer contains a polymer containing alkyl (meth)acrylate, (meth)acryloylmorpholine, and monomers having crosslinkable groups as monomer units, and a crosslinking agent that can crosslink the crosslinkable groups, and the content of (meth)acryloylmorpholine is 7% by mass or more based on the total amount of monomer units in the polymer. [2] The temporary protective film according to [1], wherein the crosslinkable group is an acidic group and the crosslinking agent is an epoxy group. [3] The temporary protective film according to [2], wherein the crosslinking agent further comprises an amino group. [4] A temporary protective film according to any one of [1] to [3], wherein the crosslinking agent has a group represented by the following formula (1). [ka] [5] A method for manufacturing a semiconductor device, comprising in this order: a step of attaching a temporary protective film to one side of a substrate; a step of mounting a semiconductor element on the side of the substrate opposite to the temporary protective film; a step of sealing the semiconductor element; and a step of peeling the temporary protective film from the substrate, wherein the temporary protective film comprises a support film and an adhesive layer provided on the support film, and the adhesive layer contains a polymer containing alkyl (meth)acrylate, (meth)acryloylmorpholine, and monomers having crosslinkable groups as monomer units, and a crosslinking agent that can crosslink the crosslinkable groups, and the content of (meth)acryloylmorpholine is 7% by mass or more based on the total amount of monomer units in the polymer. [6] The method for producing the crosslinkable group is an acidic group and the crosslinking agent is an epoxy group, as described in [5]. [7] The method for producing the crosslinking agent according to [6], wherein the crosslinking agent further has an amino group. [8] A method for manufacturing according to any one of [5] to [7], wherein the crosslinking agent has a group represented by the following formula (1). [ka] [Effects of the Invention]

[0008] According to one aspect of the present invention, it is possible to provide a temporary protective film that has excellent adhesive strength at room temperature while suppressing residue on the adherend when peeled off. [Brief explanation of the drawing]

[0009] [Figure 1] This is a cross-sectional view showing one embodiment of a temporary protective film. [Figure 2] This is a cross-sectional view illustrating one embodiment of a method for manufacturing a semiconductor device. [Figure 3] This is a cross-sectional view illustrating one embodiment of a method for manufacturing a semiconductor device. [Figure 4] This is a cross-sectional view showing one embodiment of a semiconductor device. [Figure 5] This is a perspective view showing one embodiment of a reel body. [Modes for carrying out the invention]

[0010] Embodiments of the present invention will be described below. Figure 1 is a cross-sectional view showing a temporary protective film according to one embodiment. As shown in Figure 1, the temporary protective film 10 according to one embodiment comprises a support film 1 and an adhesive layer 2 provided on the support film 1. The temporary protective film 10 can be used as a temporary protective film for semiconductor device manufacturing. More specifically, the temporary protective film 10 can be used as a temporary protective film for semiconductor encapsulation molding to temporarily protect the lead frame during encapsulation molding by being attached to the back surface of the lead frame (the surface opposite to the surface on which the semiconductor element is mounted) in the process of forming an encapsulation layer that encapsulates semiconductor elements mounted on the die pads of the lead frame.

[0011] The support film 1 may be a film of at least one polymer selected from the group consisting of polyimide, polyamide, polyamideimide, polysulfone, polyethersulfone, polyphenylene sulfide, polyetherketone, polyarylate, polyetheretherketone, and polyethylene naphthalate, and preferably a polyimide film. The polyimide may be an aromatic polyimide. The support film 1 may also be a film of copper, aluminum, stainless steel, or nickel. If the support film 1 is a polymer film, its surface may be surface-treated by methods such as chemical treatment such as alkali treatment and silane coupling treatment, physical treatment such as sand matting, plasma treatment, and corona treatment.

[0012] The thickness of the support film 1 may be, for example, 5 μm or more, 100 μm or less, or 50 μm or less. The ratio T2 / T1 of the thickness of the adhesive layer 2 to the thickness T1 of the support film 1 may be 0.1 or more, 0.5 or less, 0.3 or less, or 0.2 or less.

[0013] The adhesive layer 2 contains a polymer (hereinafter also referred to as "acrylic polymer") that includes alkyl (meth)acrylate, (meth)acryloylmorpholine, and monomers having crosslinkable groups (hereinafter also referred to as "crosslinkable monomers") as monomer units.

[0014] In the alkyl (meth)acrylate, the alkyl group (the alkyl group portion other than the (meth)acryloyl group) may be linear or branched. The number of carbon atoms of the alkyl group may be 2 or more or 3 or more, and may be 30 or less, 20 or less, 10 or less, 7 or less, 5 or less, or 4 or less, and may be 2 or 4.

[0015] Examples of the alkyl (meth)acrylate include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, pentyl (meth)acrylate, n-hexyl (meth)acrylate, n-heptyl (meth)acrylate, n-octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, nonyl (meth)acrylate, and decyl (meth)acrylate.

[0016] The crosslinkable monomer has a polymerizable group copolymerizable with the alkyl (meth)acrylate and (meth)acryloylmorpholine in addition to the crosslinkable group. The polymerizable group may be, for example, an ethylenically unsaturated group. The crosslinkable group may be, for example, an acidic group. The acidic group may be, for example, a carboxyl group or a sulfo group, and preferably a carboxyl group.

[0017] Examples of the crosslinkable monomer having a carboxyl group include (meth)acrylic acid, carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, phthalic acid mono-hydroxyethyl acrylate, and 2-acryloyloxyethyl succinate.

[0018] Acrylic polymers may further contain other monomers as monomer units other than alkyl (meth)acrylates, (meth)acryloylmorpholine, and crosslinkable monomers. Other monomers may be monomers having polymerizable groups (e.g., ethylenically unsaturated groups) and hydroxyl groups. Examples of these monomers include hydroxyalkyl (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 8-hydroxyoctyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, and 12-hydroxylauryl (meth)acrylate; and hydroxyalkylcycloalkane (meth)acrylates such as (4-hydroxymethylcyclohexyl)methyl (meth)acrylate.

[0019] In the acrylic polymer, the (meth)acryloylmorpholine content is 7% by mass or more, based on the total amount of monomer units in the acrylic polymer. This provides a temporary protective film that has excellent adhesive strength at room temperature while suppressing residue on the adherend when peeled off. The (meth)acryloylmorpholine content is preferably 7.5% by mass or more, 8% by mass or more, 8.5% by mass or more, or 9.0% by mass or more, based on the total amount of monomer units in the acrylic polymer, and may also be 20% by mass or less, 18% by mass or less, 17% by mass or less, 16.5% by mass or less, or 16% by mass or less.

[0020] The alkyl (meth)acrylate content may be 70% by mass or more, 75% by mass or more, or 80% by mass or more, and may be 92% by mass or less, 90% by mass or less, or 88% by mass or less, based on the total amount of monomer units in the acrylic polymer.

[0021] The content of the crosslinkable monomer may be 1% by mass or more, 2% by mass or more, or 3% by mass or more, and may be 10% by mass or less, 6% by mass or less, or 4% by mass or less, based on the total amount of monomer units in the acrylic polymer.

[0022] The content of other monomers may be 0.1% by mass or more, 0.5% by mass or more, or 1% by mass or more, and may be 5% by mass or less, 4% by mass or less, or 3% by mass or less, based on the total amount of monomer units in the acrylic polymer.

[0023] The mass ratio of (meth)acryloylmorpholine content to alkyl (meth)acrylate content ((meth)acryloylmorpholine / alkyl (meth)acrylate) may be 0.08 / 1 or more, 0.09 / 1 or more, or 0.1 / 1 or more, and may be 0.3 / 1 or less, 0.25 / 1 or less, 0.23 / 1 or less, 0.21 / 1 or less, or 0.2 / 1 or less.

[0024] The acid value of the acrylic polymer may be 10 mg KOH / g or more or 20 mg KOH / g or more, and 40 mg KOH / g or less or 30 mg KOH / g or less. The hydroxyl value of the acrylic polymer may be 1 mg KOH / g or more or 2 mg KOH / g or more, and 10 mg KOH / g or less or 5 mg KOH / g or less. The acid value and hydroxyl value of the acrylic polymer are measured in accordance with the method described in JIS K0070.

[0025] The acrylic polymer content may be 80% by mass or more, 85% by mass or more, or 90% by mass or more, based on the total amount of adhesive layer 2, and may be 99.5% by mass or less, or 99% by mass or less.

[0026] The adhesive layer 2 further contains a crosslinking agent. The crosslinking agent is a crosslinking agent that can crosslink with the crosslinkable groups in the acrylic polymer. Known crosslinking agents can be used as such crosslinking agents. When the crosslinkable groups in the acrylic polymer are acidic groups, the crosslinking agent preferably has epoxy groups. The number of epoxy groups in the crosslinking agent may be 2 or more, 3 or more, 4 or less, or 4.

[0027] In one embodiment, the crosslinking agent may be a crosslinking agent having an amino group in addition to an epoxy group. The amino group may be an amino group in which a hydrogen atom in -NH2 is substituted (substituted amino group), or it may be a tertiary amino group. Such a crosslinking agent may have a group represented by the following formula (1). [ka] The number of groups represented by formula (1) in the crosslinking agent may be 1 or 2.

[0028] The crosslinking agent may be a crosslinking agent represented by the following formula (2). [ka] In the formula, X represents a divalent hydrocarbon group.

[0029] The divalent hydrocarbon group represented by X may be a divalent hydrocarbon group having a ring. The ring may be an alicyclic ring or an aromatic ring. The number of carbon atoms constituting the ring may be 5 or more, 8 or less, or 6. The number of rings in the divalent hydrocarbon group may be 1 or more, 3 or less, or 1 or 2. If the divalent hydrocarbon group contains multiple rings, these multiple rings may be directly bonded to each other or bonded via alkylene groups having 1 to 3 carbon atoms.

[0030] The divalent hydrocarbon group represented by X preferably has a cycloalkylene group. The number of carbon atoms in the cycloalkylene group may be 5 or more, or 8 or less. The cycloalkylene group is preferably a cyclohexylene group.

[0031] In one embodiment, the crosslinking agent may be a crosslinking agent having an ether group in addition to an epoxy group (but no amino group). Such a crosslinking agent may have a group represented by the following formula (3). [ka] The number of groups represented by formula (3) in the crosslinking agent may be 2 or more, 3 or more, 4 or less, or 2 or 4.

[0032] The crosslinking agent may be a crosslinking agent represented by the following formula (4). [ka] In the formula, m represents an integer greater than or equal to 2, n represents an integer greater than or equal to 0, and A represents a residue obtained by removing the hydroxyl group from an m+n valent polyhydric alcohol.

[0033] m may be an integer greater than or equal to 3, an integer less than or equal to 4, or 2 or 4. n may be an integer greater than or equal to 1, an integer less than or equal to 2, or 0 or 2. m+n may be an integer greater than or equal to 2, or an integer less than or equal to 6.

[0034] The polyhydric alcohol in A may be an aliphatic polyhydric alcohol, or a polyhydric alcohol having an ether group. The number of carbon atoms in the aliphatic polyhydric alcohol may be 2 or more, 3 or more, or 4 or more, or 10 or less, 9 or less, or 8 or less. The polyhydric alcohol having an ether group may be a polyalkylene glycol such as polyethylene glycol.

[0035] The crosslinking agent is preferably a crosslinking agent having epoxy groups and amino groups as described above. In this case, it is possible to suppress deterioration of the appearance of the adherend after peeling off the temporary protective film (for example, the formation of unwanted patterns on the adherend).

[0036] The crosslinking agent content may be 0.5% by mass or more, 15% by mass or less, or 10% by mass or less, based on the total amount of the adhesive layer 2. From the viewpoint of suppressing deterioration of the appearance of the adherend after the temporary protective film is peeled off from the adherend, it is preferably 1% by mass or more, 2% by mass or more, or 2.5% by mass or more.

[0037] The crosslinking agent content may be 0.5 parts by mass or more, 15 parts by mass or less, or 10 parts by mass or less, per 100 parts by mass of acrylic polymer content. From the viewpoint of suppressing deterioration of the appearance of the adherend after peeling off the temporary protective film from the adherend, it is preferably 1 part by mass or more, 2 parts by mass or more, or 3 parts by mass or more.

[0038] The adhesive layer 2 may further contain other components besides the acrylic polymer and the crosslinking agent. Examples of other components include polymers other than the acrylic polymer and coupling agents.

[0039] The thickness of the adhesive layer 2 may be 1 μm or more, 2 μm or more, 3 μm or more, 4 μm or more, or 5 μm or more, and may be 20 μm or less, 18 μm or less, 16 μm or less, 14 μm or less, 12 μm or less, or 10 μm or less.

[0040] In another embodiment, the temporary protective film may further include a cover film provided on the surface opposite to the support film of the adhesive layer. That is, the temporary protective film may include a support film, an adhesive layer, and a cover film in this order. The cover film may be a polyethylene teretale film. The thickness of the cover film may be 10 μm or more and 100 μm or less.

[0041] In another embodiment, the temporary protective film may further comprise a non-adhesive layer provided on the side opposite to the adhesive layer of the support film. The non-adhesive layer may be a resin layer that has substantially no adhesion to the adherend at temperatures between 0 and 270°C. The non-adhesive layer may contain a thermoplastic resin, a thermosetting resin (cured product), or a combination thereof. The non-adhesive layer may further contain fillers (e.g., ceramic powder, glass powder, silver powder, copper powder, resin particles, rubber particles), coupling agents, etc. The thickness of the non-adhesive layer may be 1 μm or more and 10 μm or less.

[0042] A temporary protective film can be manufactured, for example, by a method that includes the step of applying a varnish containing an acrylic polymer and a crosslinking agent onto a support film, and then removing the solvent from the coating to form an adhesive layer.

[0043] Next, a method for manufacturing a semiconductor device using the temporary protective film described above will be explained. One embodiment of the method for manufacturing a semiconductor device comprises, in this order: step S1 of attaching a temporary protective film to one side of a substrate; step S2 of mounting a semiconductor element on the side of the substrate opposite to the temporary protective film; step S3 of sealing the semiconductor element; and step S4 of peeling the temporary protective film off the substrate. Below, as an example, a method for manufacturing a semiconductor device (semiconductor device package) when the substrate is a lead frame will be explained in more detail.

[0044] Figure 2 is a cross-sectional view illustrating one embodiment (step S1) of a semiconductor device manufacturing method. In step S1, as shown in Figure 2, a temporary protective film 10 is attached to the back surface, which is one side of the lead frame 11 having a die pad 11a and inner leads 11b. The temporary protective film 10 is attached in a direction in which the adhesive layer of the temporary protective film 10 is in contact with the lead frame 11.

[0045] The lead frame 11 may be formed from, for example, an iron-based alloy such as 42 alloy, copper, or a copper-based alloy. The lead frame 11 may have a molded body formed from copper or a copper-based alloy and a coating layer of palladium, gold, silver, etc. covering its surface.

[0046] The temporary protective film 10 has excellent adhesive strength at room temperature (e.g., 25°C), and can therefore be attached to the lead frame 11 at room temperature. The temporary protective film 10 may also be attached to the lead frame 11 while heating and pressurizing. In this case, the heating temperature may be 150°C or higher and 400°C or lower. The pressure may be 0.5 MPa or higher and 30 MPa or lower. The heating and pressurizing time may be 1 second or more and 60 seconds or less.

[0047] Figure 3 is a cross-sectional view illustrating one embodiment (steps S2 and S3) of a semiconductor device manufacturing method. In step S2, as shown in Figure 3, a semiconductor element 14 is mounted on the side of the die pad 11a opposite to the temporary protective film 10. The semiconductor element 14 is bonded to the die pad 11a via an adhesive (e.g., silver paste). After bonding the semiconductor element 14 to the die pad 11a, reflow bonding (such as CuClip bonding) may be performed at a maximum temperature of 250 to 440°C, or 250 to 400°C, for 1 to 30 minutes.

[0048] Next, the semiconductor element 14 is connected to the inner lead 11b using a wire 12. The wire 12 may be, for example, a gold wire, a copper wire, or a palladium-coated copper wire. The wire 12 may be joined to the semiconductor element 14 and the inner lead 11b using ultrasound and pressing pressure while being heated at, for example, 200 to 350°C.

[0049] Next, in step S3, as shown in Figure 3, a sealing layer 13 is formed to enclose the semiconductor element 14 and the wire 12. This results in a temporarily protected sealed molded body 20 having the lead frame 11, semiconductor element 14, and sealing layer 13.

[0050] The sealing layer 13 is formed by sealing molding using a sealing material. By sealing molding, a sealed molded body 20 having a plurality of semiconductor elements 14 and a sealing layer 13 that seals them together may be obtained. During sealing molding, a temporary protective film 10 is provided to prevent the sealing material from flowing to the back side of the lead frame 11.

[0051] The temperature during the formation of the sealing layer 13 (temperature of the sealing material) may be 140-200°C or 160-180°C. The pressure during the formation of the sealing layer may be 6-15 MPa or 7-10 MPa. The sealing molding time may be 1-5 minutes or 2-3 minutes.

[0052] The encapsulant may contain epoxy resins such as cresol novolac epoxy resin, phenol novolac epoxy resin, biphenyl diepoxy resin, or naphthol novolac epoxy resin. The encapsulant may also contain fillers, flame retardants such as bromine compounds, wax components, etc.

[0053] After the formation of the sealing layer 13 (sealing molding), the temporary protective film 10 is peeled off from the lead frame 11 and the sealing layer 13 of the obtained sealed molded body 20. When curing the sealing layer, the temporary protective film 10 may be peeled off either before or after the curing of the sealing layer.

[0054] The temperature at which the temporary protective film is peeled off is not particularly limited, but it may be room temperature (e.g., 5-35°C). This temperature may be above the glass transition temperature of the adhesive layer. In this case, the peelability of the temporary protective film from the lead frame and sealant will be even better. If the Tg of the acrylic rubber in the adhesive layer is, for example, 5°C or less or 0°C or less, the Tg of the adhesive layer will be equal to or lower than room temperature, making it easier to obtain good peelability at room temperature.

[0055] If the lead frame includes multiple patterns having die pads and inner leads, the encapsulated molded body 20 can be divided as needed to obtain multiple semiconductor devices (semiconductor packages) 100, each having one semiconductor element, as shown in Figure 4. That is, if the lead frame 11 has multiple die pads 11a, and a semiconductor element 14 is mounted on each of the multiple die pads 11a, the manufacturing method according to one embodiment may further include the step of peeling off the temporary protective film 10 from the encapsulated molded body 20, then dividing the encapsulated molded body 20 to obtain a semiconductor device (semiconductor package) 100 having one die pad 11a and one semiconductor element 14.

[0056] The temporary protective film may be in a long form and may be used in the form of a reel wound on a core. In this case, the temporary protective film is applied to the object as it is unwound from the reel.

[0057] Figure 5 is a perspective view showing one embodiment of a reel body. As shown in Figure 5, a reel body 30 according to one embodiment comprises a winding core 31, a temporary protective film 10 wound on the winding core 31, and a side plate 32. The width (length in the direction perpendicular to the winding direction) of the winding core 31 and the temporary protective film 10 may be 1 mm or more, 5 mm or more, or 10 mm or more, and may be 1000 mm or less, 800 mm or less, or 500 mm or less. In another embodiment, the reel body may not have a side plate. [Examples]

[0058] The present invention will be described in more detail below with reference to examples. However, the present invention is not limited to these examples.

[0059] (Example 1) Acrylic polymer A-1 was prepared, containing 80% by mass of butyl acrylate (BA), 16% by mass of acryloyl morpholine (ACMO), 3% by mass of acrylic acid, and 1% by mass of other monomers (monomers having a hydroxyl group) as monomer units. 100 parts by mass of acrylic polymer A-1 and the following formula (B-1): [ka] Ten parts by mass of the crosslinking agent B-1 represented by [formula] were dissolved in cyclohexanone to obtain a varnish for forming an adhesive layer.

[0060] A polyimide film (thickness: 25 μm, manufactured by Toray DuPont, trade name: Kapton 100EN) was prepared as the support film. The resulting varnish was applied to one side of the support film. The coating on the support film was dried by heating at 90°C for 1.5 minutes and then at 260°C for 1.5 minutes to form a 5 μm thick adhesive layer. This obtained a temporary protective film.

[0061] (Example 2) A temporary protective film was obtained in the same manner as in Example 1, except that acrylic polymer A-2, which was obtained by changing the monomer composition of acrylic polymer A-1 to 86.5% by mass of BA and 9.5% by mass of ACMO, was used instead of acrylic polymer A-1.

[0062] (Comparative Example 1) A temporary protective film was obtained in the same manner as in Example 1, except that acrylic polymer A-3, which was obtained by changing the monomer composition of acrylic polymer A-1 to 90.5% by mass of BA and 5.5% by mass of ACMO, was used instead of acrylic polymer A-1.

[0063] (Example 3) The following formula (B-2): [ka] A temporary protective film was obtained in the same manner as in Example 1, except that the crosslinking agent B-2 represented by [formula] was used in place of crosslinking agent B-1.

[0064] (Example 4) The following formula (B-3): [ka] A temporary protective film was obtained in the same manner as in Example 1, except that the crosslinking agent B-3 represented by [formula] was used in place of crosslinking agent B-1.

[0065] (Examples 5-8) A temporary protective film was obtained in the same manner as in Example 1, except that the mixing ratio (parts by mass) of acrylic polymer A-1 and crosslinking agent B-1 was changed as shown in Table 1.

[0066] (Example 9) A temporary protective film was obtained in the same manner as in Example 1, except that the thickness of the adhesive layer was changed to 10 μm.

[0067] (Evaluation of adhesive strength) (1) After applying at room temperature EFTEC64TCu plate (Cu-Fe-P alloy, manufactured by Shinko Electric Industries, Ltd.) and CDA194 palladium-plated plate (PPF, manufactured by Shinko Electric Industries, Ltd.) were prepared as adherends. Each of these adherends was fitted with a temporary protective film cut to a size of 10 mm × 50 mm using a hand roller at 25°C and a load of 20 N, with the adhesive layer facing the adherend, to obtain each attached object. Next, each temporary protective film was peeled off at a speed of 50 mm / min at a 90-degree angle to the main surface of the lead frame at 25°C using a force gauge. The maximum load per 10 mm width of the adhesive layer (N / m) at that time was measured as the adhesive strength (90-degree peel strength) after application at room temperature. The results are shown in Table 1.

[0068] (2) Adhesion after heat treatment Each adhesive obtained in the same manner as in (1) above was subjected to heat treatment in an oven under an air atmosphere at 180°C for 60 minutes, followed by 200°C for 60 minutes. Subsequently, using a force gauge, the temporary protective film was peeled off at a speed of 50 mm / min in a direction 90 degrees to the main surface of the lead frame at 25°C. The maximum load per 10 mm width of the adhesive layer at that time (N / m) was measured as the adhesive strength (90-degree peel strength) after heat treatment. The results are shown in Table 1.

[0069] (3) Evaluation of residues Each temporary protective film was attached to a CDA194 palladium-plated Cu plate (lead frame, manufactured by Shinko Electric Industries, Ltd.) with the adhesive layer facing the lead frame, under conditions of 25°C and a load of 20N. The resulting bond was heated in an oven under an air atmosphere at 180°C for 60 minutes, followed by 200°C for 60 minutes, changing the conditions in that order. The side of the lead frame opposite to the temporary protective film was plasma-treated under an argon gas atmosphere (flow rate: 20 sccm), at 150W for 15 seconds.

[0070] Using a mold molding machine (manufactured by Apic Yamada Co., Ltd.), a sealing layer was formed on the side of the lead frame opposite to the temporary protective film using a sealing material (product name: GE-300, manufactured by Showa Denko Materials Co., Ltd.). The sealing conditions were 175°C, 6.8 MPa, and 2 minutes. Subsequently, at 25°C, each temporary protective film was peeled off at a speed of 50 mm / min in a direction 180° relative to the surface of the lead frame. The condition of the adhesive layer remaining on the sealing layer after peeling off the temporary protective film was checked. The ratio of the area occupied by the adhesive layer residue to the surface area of ​​the sealing layer was determined. Based on the ratio of the area occupied by the adhesive layer residue, the peelability after sealing molding was evaluated using the following five-level criteria. The results are shown in Table 1. 5:60~100% 4: 40% to less than 60% 3: 20% or more but less than 40% 2: 10% or more but less than 20% 1: 0% or more, less than 10%

[0071] (4) Evaluation of appearance After peeling off each temporary protective film as described in (3) above, we checked whether there were any areas with different hues on the sealing layer. Based on whether or not there were areas with different hues, we evaluated the appearance after sealing and molding according to the following criteria. The results are shown in Table 1. ○: No areas with different hues exist (it is almost uniformly black (the color of the sealing layer)). ×: Areas with different hues exist (there are white linear areas within the black surface).

[0072] [Table 1] [Explanation of Symbols]

[0073] 1...Support film, 2...Adhesive layer, 10...Temporary protective film, 11...Lead frame, 11a...Die pad, 11b...Inner lead, 12...Wire, 13...Sealing layer, 14...Semiconductor element, 20...Sealed molded body, 100...Semiconductor device.

Claims

1. Support film and The support film comprises an adhesive layer provided on the support film, The aforementioned adhesive layer A polymer comprising alkyl (meth)acrylate having an alkyl group with 4 or fewer carbon atoms, (meth)acryloylmorpholine, and a monomer having a crosslinkable group as monomer units, The above-mentioned crosslinkable group and a crosslinkable crosslinking agent are included, The content of the alkyl (meth)acrylate having an alkyl group having 4 or fewer carbon atoms is 70% by mass or more based on the total amount of monomer units in the polymer. A temporary protective film for manufacturing semiconductor devices, wherein the (meth)acryloylmorpholine content is 7% by mass or more based on the total amount of monomer units in the polymer.

2. The temporary protective film according to claim 1, wherein the crosslinkable group is an acidic group and the crosslinking agent has an epoxy group.

3. The temporary protective film according to claim 2, wherein the crosslinking agent further comprises an amino group.

4. The temporary protective film according to any one of claims 1 to 3, wherein the crosslinking agent has a group represented by the following formula (1). 【Chemistry 1】

5. The process involves attaching a temporary protective film to one side of the circuit board, A step of mounting a semiconductor element on the surface of the substrate opposite to the temporary protective film, A step of sealing the semiconductor element, The steps include peeling the temporary protective film from the substrate, A method for manufacturing a semiconductor device, comprising the following in this order: The aforementioned temporary protective film Support film and The support film comprises an adhesive layer provided on the support film, The aforementioned adhesive layer A polymer comprising alkyl (meth)acrylate having an alkyl group with 4 or fewer carbon atoms, (meth)acryloylmorpholine, and a monomer having a crosslinkable group as monomer units, The above-mentioned crosslinkable group and a crosslinkable crosslinking agent are included, The content of the alkyl (meth)acrylate having an alkyl group having 4 or fewer carbon atoms is 70% by mass or more based on the total amount of monomer units in the polymer. A method for producing the polymer, wherein the content of (meth)acryloylmorpholine is 7% by mass or more, based on the total amount of monomer units in the polymer.

6. The manufacturing method according to claim 5, wherein the crosslinkable group is an acidic group and the crosslinking agent has an epoxy group.

7. The manufacturing method according to claim 6, wherein the crosslinking agent further has an amino group.

8. The manufacturing method according to any one of claims 5 to 7, wherein the crosslinking agent has a group represented by the following formula (1). 【Chemistry 2】

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