Film and method for manufacturing the same, and method for manufacturing a semiconductor package

Abstract

Provided is a film comprising at least a base material and an antistatic layer, the film being such that: the proportion of the peeling surface area when a tape peeling test is conducted after 300% monoaxial stretching at 25°C is less than 5%; the expression (H2−H1)≥0 is satisfied when a swabbing test is conducted after 300% monoaxial stretching at 25°C (where H1 is the haze before swabbing, and H2 is the haze after swabbing); or either O / C is within the range of 0.010-0.200, or N / F is within the range of 0.010-0.100, in surface chemical composition analysis of the antistatic-layer side of the base material according to X-ray photoelectron spectroscopy. Also provided are a method for manufacturing the film, and a method for manufacturing a semiconductor package using the film.

Description

[Technical Field]

[0001] This disclosure relates to a film and a method for manufacturing the same, as well as a method for manufacturing a semiconductor package. [Background technology]

[0002] Films used in various industrial fields may have an antistatic layer to suppress static electricity buildup.

[0003] For example, semiconductor elements are sealed in a package form and mounted on a substrate to shield and protect them from the outside air. Curable resins such as epoxy resins are used to seal semiconductor elements. Resin sealing is performed by placing the semiconductor element in a predetermined location in a mold, filling the mold with a curable resin, and allowing it to harden. Transfer molding and compression molding are generally known sealing methods. In the sealing of semiconductor elements, a release film is often placed on the inner surface of the mold to improve the release properties of the package from the mold. For example, Patent Documents 1 to 3 describe films suitable for the manufacture of semiconductor packages. When a release film is used to encapsulate semiconductor devices, static electricity is generated when the film is peeled from the package, making the film prone to becoming charged. A charged film may damage or destroy the semiconductor package through discharge. Furthermore, a damaged semiconductor package may have reduced resistance to static electricity in the operating environment. Therefore, from the viewpoint of semiconductor package productivity and resistance to static electricity in the semiconductor package's operating environment, it is preferable to use a film with an antistatic layer as the release film.

[0004] Patent Document 2 proposes a film containing at least one antistatic agent selected from the group consisting of conductive polymers and conductive metal oxides as a release film for the manufacture of semiconductor packages. [Prior art documents] [Patent Documents]

[0005]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0006] On the other hand, there is a need for a technology to further improve the antistatic performance of films. For example, in recent years, due to the requirements for miniaturization and thinning of semiconductor products, the need for reducing the thickness of semiconductor packages has been increasing. Along with this, it is desirable to also reduce the thickness of the encapsulating resin. However, it has been found that when the thickness of the encapsulating resin is reduced, the package is more likely to be damaged by the charges generated during film peeling. Therefore, there is a need for a film with higher antistatic performance.

[0007] In view of such a situation, the present disclosure relates to providing a film having excellent antistatic performance, a method for manufacturing the same, and a method for manufacturing a semiconductor package using the same.

Means for Solving the Problems

[0008] The means for solving the above problems include the following aspects. <1> Comprising at least a base material and an antistatic layer, A film characterized in that when a tape peeling test is performed under the following conditions after uniaxial stretching at 300% at 25°C, the ratio of the peeling area is less than 5%. Using a roller, cellophane (registered trademark) is pressure-bonded to the surface of the film on the antistatic layer side with a load of 4 kg for 5 reciprocations, and within 5 minutes, the cellophane (registered trademark) is peeled from the film in a 180° direction at a speed of 100 m / min to obtain the ratio of the peeling area of the film to the area of the adhesive part of the cellophane (registered trademark). <2> The film according to <1>, which satisfies the formula (H2 - H1) ≧ 0 when a wiping test is performed under the following conditions after uniaxial stretching at 25°C by 300%. The film is wiped by rubbing the surface on the antistatic layer side of the film 20 times back and forth with a load of 4 kg using a non-woven fabric attached with acetone. The haze before and after wiping at the same location on the film is measured, and the haze before wiping is designated as H1, and the haze after wiping is designated as H2. <3> The film according to <1> or <2>, wherein in the surface chemical composition analysis of the substrate on the antistatic layer side by X-ray photoelectron spectroscopy, O / C is in the range of 0.010 to 0.200. <4> The film according to any one of <1> to <3>, wherein in the surface chemical composition analysis of the substrate on the antistatic layer side by X-ray photoelectron spectroscopy, N / F is in the range of 0.010 to 0.100. <5> Comprising at least a substrate and an antistatic layer, A film characterized in that it satisfies the formula (H2 - H1) ≧ 0 when a wiping test is performed under the following conditions after uniaxial stretching at 25°C by 300%. The film is wiped by rubbing the surface on the antistatic layer side of the film 20 times back and forth with a load of 4 kg using a non-woven fabric attached with acetone. The haze before and after wiping at the same location on the film is measured, and the haze before wiping is designated as H1, and the haze after wiping is designated as H2. <6> The film according to <5>, wherein in the surface chemical composition analysis of the substrate on the antistatic layer side by X-ray photoelectron spectroscopy, O / C is in the range of 0.010 to 0.200. <7> The film according to <5> or <6>, wherein in the surface chemical composition analysis of the substrate on the antistatic layer side by X-ray photoelectron spectroscopy, N / F is in the range of 0.010 to 0.100. [[ID=!18]]<8> Comprising at least a substrate and an antistatic layer, A film characterized in that in the surface chemical composition analysis of the substrate on the antistatic layer side by X-ray photoelectron spectroscopy, O / C is in the range of 0.010 to 0.200. <9> In the surface chemical composition analysis of the antistatic layer side of the substrate by X-ray photoelectron spectroscopy, the N / F ratio is in the range of 0.010 to 0.100. <8> The film described above. <10> The material comprises at least a base material and an antistatic layer, A film characterized in that, in surface chemical composition analysis of the antistatic layer side of the substrate by X-ray photoelectron spectroscopy, the N / F ratio is in the range of 0.010 to 0.100. <11> The surface of the substrate facing the antistatic layer is plasma treated. <1> ~ <10> The film described in any one of the items. <12> The substrate comprises at least one selected from the group consisting of fluororesin, polymethylpentene, syndiotactic polystyrene, and polycycloolefin. <1> ~ <11> The film described in any one of the items. <13> The substrate comprises at least one selected from the group consisting of ethylene-tetrafluoroethylene copolymer, tetrafluoroethylene-hexafluoropropylene copolymer, tetrafluoroethylene-perfluoro(alkyl vinyl ether) copolymer, and tetrafluoroethylene-hexafluoropropylene-vinylidene fluoride copolymer. <1> ~ <12> The film described in any one of the items. <14> The antistatic layer is further provided with an adhesive layer on the side opposite to the substrate. <1> ~ <13> The film described in any one of the items. <15> This is a release film used in the process of encapsulating semiconductor devices with a curable resin. <1> ~ <14> The film described in any one of the items. <16> Plasma treatment of the substrate surface, The antistatic layer is provided on the plasma-treated substrate, or the antistatic layer is provided on the plasma-treated substrate via at least a third layer adjacent to the substrate. Includes, A method for manufacturing a film, characterized in that, in surface chemical composition analysis of the antistatic layer side of the substrate after plasma treatment by X-ray photoelectron spectroscopy, the O / C ratio is in the range of 0.010 to 0.200, the N / F ratio is in the range of 0.010 to 0.100, or both of these conditions are met. <17> The plasma treatment is carried out in the presence of argon gas, ammonia gas, or nitrogen gas which may or may not contain 10% by volume of hydrogen gas. <16> A method for manufacturing the film described above. <18> The process further includes corona treatment of the surface of the substrate prior to the plasma treatment. <16> or <17> A method for manufacturing the film described above. <19> This includes providing an adhesive layer on the side of the antistatic layer opposite to the substrate, <16> ~ <18> A method for manufacturing a film as described in any one of the items. <20> <1> ~ <15> The film or <16> ~ <19> The film manufactured by the manufacturing method described in any one of the items is placed on the inner surface of the mold, A substrate comprising a semiconductor element is placed within the mold in which the aforementioned film is arranged. The semiconductor element in the mold is sealed with a curable resin to produce a sealed body, The sealing body is released from the mold, A method for manufacturing a semiconductor package, characterized by including the following: [Effects of the Invention]

[0009] This disclosure provides a film with excellent antistatic properties, a method for manufacturing the same, and a method for manufacturing a semiconductor package using the same. [Brief explanation of the drawing]

[0010] [Figure 1] A schematic cross-sectional view of a film in one aspect of this disclosure is shown. [Modes for carrying out the invention]

[0011] The embodiments for carrying out the embodiments of this disclosure will be described in detail below. However, the embodiments of this disclosure are not limited to the embodiments described below. In the embodiments described below, the components (including elemental steps, etc.) are not essential unless otherwise specified. The same applies to numerical values ​​and their ranges, and do not limit the embodiments of this disclosure.

[0012] In this disclosure, the term "process" includes not only processes that are independent of other processes, but also processes that cannot be clearly distinguished from other processes, provided that the purpose of such process is achieved. In this disclosure, the numerical range indicated using "~" includes the numbers before and after "~" as the minimum and maximum values, respectively. In numerical ranges described in stages within this disclosure, the upper or lower limit of one numerical range may be replaced with the upper or lower limit of another numerical range described in stages. Furthermore, in numerical ranges described within this disclosure, the upper or lower limit of that range may be replaced with the values ​​shown in the examples. In this disclosure, each component may contain multiple types of the corresponding substance. If multiple types of the substance corresponding to each component are present in the composition, the content or amount of each component means the total content or amount of the multiple types of substances present in the composition, unless otherwise specified. When embodiments are described in this disclosure with reference to the drawings, the configuration of such embodiments is not limited to the configuration shown in the drawings. Furthermore, the sizes of the components in the drawings are conceptual, and the relative relationships between the components are not limited thereto. In this disclosure, the term "unit" in a polymer refers to a portion derived from a monomer that exists within the polymer and constitutes the polymer. Furthermore, a unit is also defined as a chemically transformed version of a unit's structure after polymer formation. In some cases, units derived from individual monomers are referred to by a name consisting of the monomer name followed by "unit." In this disclosure, films and sheets are referred to as "films" regardless of their thickness. In this disclosure, acrylates and methacrylates are collectively referred to as "(meth)acrylates," and acrylics and methacrylics are collectively referred to as "(meth)acrylics." In this disclosure, the films according to the first to fourth embodiments may be collectively referred to as "the films of this disclosure."

[0013] ≪Film≫ A film according to the first embodiment of this disclosure comprises at least a substrate and an antistatic layer, and after uniaxial stretching to 300% at 25°C, the percentage of the peeled area when a tape peel test is performed under the following conditions is less than 5%. Using a roller, cellophane tape (registered trademark) is pressed and adhered to the antistatic layer side surface of the film with a load of 4 kg for 5 back-and-forth movements. Within 5 minutes, the cellophane tape (registered trademark) is peeled off from the film at a speed of 100 m / min in a direction 180°, and the ratio of the peeled area of ​​the film to the adhesive area of ​​the cellophane tape (registered trademark) is obtained. Here, the adhesive part of Cellotape (registered trademark) refers to the portion of the film's surface to which Cellotape (registered trademark) was attached.

[0014] A film according to the second embodiment of this disclosure comprises at least a substrate and an antistatic layer, and satisfies formula (H2-H1)≧0 when a wipe test is performed under the following conditions after uniaxial stretching to 300% at 25°C. The film is wiped by rubbing the surface of the antistatic layer side of the film back and forth 20 times with a nonwoven fabric coated with acetone under a load of 4 kg. The haze is measured at the same location on the film before and after wiping, with the haze before wiping designated as H1 and the haze after wiping as H2.

[0015] A film according to the third embodiment of this disclosure comprises at least a substrate and an antistatic layer, wherein the O / C ratio is in the range of 0.010 to 0.200 in surface chemical composition analysis of the substrate on the antistatic layer side by X-ray photoelectron spectroscopy.

[0016] A film according to the fourth embodiment of this disclosure comprises at least a substrate and an antistatic layer, wherein the N / F ratio is in the range of 0.010 to 0.100 in surface chemical composition analysis of the substrate on the antistatic layer side by X-ray photoelectron spectroscopy.

[0017] The films according to the first to fourth embodiments were found to have excellent antistatic performance. Although the reason for this is not entirely clear, it is presumed that the adhesion of the antistatic layer when the film is stretched contributes to the antistatic performance of the film, and that the films according to the first to fourth embodiments have excellent adhesion of the antistatic layer, thus achieving high antistatic performance. For example, when the film is stretched, if the antistatic layer has excellent adhesion to adjacent layers, peeling or cracking of the antistatic layer is less likely to occur, and conductive paths are more easily maintained. This makes it easier for the generated static electricity to escape from the substrate, and it is presumed that excellent antistatic performance can be obtained.

[0018] The film of this disclosure only needs to comprise a substrate and an antistatic layer, and other components are not particularly limited. A schematic cross-sectional view of a film in one embodiment is shown in Figure 1. The film 1 shown in Figure 1 comprises an antistatic layer 3 on a substrate 2. Film 1 may also comprise other layers in addition to the substrate 2 and the antistatic layer 3. The components of the film of this disclosure will be described in detail below.

[0019] <Base material> The material of the base material is not particularly limited, but it is preferable that it contains a resin. In one embodiment, from the viewpoint of the release properties of the film, it is preferable that the base material contains a resin having release properties (hereinafter also referred to as "release resin"). A release resin means a resin in which the layer composed of the resin has release properties. Examples of release resins include fluororesin, polymethylpentene, syndiotactic polystyrene, polycycloolefin, silicone rubber, polyester elastomer, polybutylene terephthalate, and unoriented nylon. From the viewpoint of excellent release properties, heat resistance, strength, and elongation at high temperatures, fluororesin, polymethylpentene, syndiotactic polystyrene, and polycycloolefin are preferred, and from the viewpoint of excellent release properties, fluororesin is more preferred. The resin contained in the base material may be used alone or two or more types may be used in combination. It is particularly preferable that the base material is composed solely of fluororesin. However, even when composed solely of fluororesin, this does not prevent the inclusion of resins other than fluororesin as long as it does not impair the effects of the invention.

[0020] As a fluororesin, fluoroolefin polymers are preferred from the viewpoint of excellent release properties and heat resistance. A fluoroolefin polymer is a polymer having units based on fluoroolefin. A fluoroolefin polymer may further have units other than those based on fluoroolefin. Examples of fluoroolefins include tetrafluoroethylene (TFE), vinyl fluoride, vinylidene fluoride, trifluoroethylene, hexafluoropropylene, and chlorotrifluoroethylene. Fluoroolefins may be used individually or in combination of two or more.

[0021] Examples of fluoroolefin polymers include ethylene-tetrafluoroethylene copolymer (ETFE), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), tetrafluoroethylene-perfluoro(alkyl vinyl ether) copolymer (PFA), and tetrafluoroethylene-hexafluoropropylene-vinylidene fluoride copolymer (THV). From the viewpoint of mechanical properties, at least one selected from the group consisting of ETFE and FEP is preferred. A single fluoroolefin polymer may be used, or two or more may be used in combination.

[0022] From the viewpoint of high elongation at high temperatures, ETFE is preferred as the fluoroolefin polymer. ETFE is a copolymer having TFE units and ethylene units (hereinafter also referred to as "E units"). As for ETFE, a polymer having TFE units, E units, and units based on a third monomer other than TFE and ethylene is preferred. The type and content of the units based on the third monomer make it easy to adjust the crystallinity of ETFE, thereby making it easy to adjust the storage modulus or other tensile properties of the substrate. For example, when ETFE has units based on a third monomer (particularly a monomer containing a fluorine atom), the tensile strength and elongation at high temperatures (particularly around 180°C) tend to improve.

[0023] The third type of monomer includes monomers containing a fluorine atom and monomers that do not contain a fluorine atom. Examples of monomers containing a fluorine atom include the following monomers (a1) to (a5). Monomer (a1): Fluoroolefins having 2 or 3 carbon atoms. Monomer (a2): X(CF2) n Fluoroalkylethylenes represented by CY=CH2 (where X and Y are independently either a hydrogen atom or a fluorine atom, and n is an integer between 2 and 8). Monomer (a3): Fluorovinyl ethers. Monomer (a4): Functional group-containing fluorovinyl ethers. Monomer (a5): A fluorine-containing monomer having an aliphatic ring structure.

[0024] Examples of monomers (a1) include fluoroethylenes (trifluoroethylene, vinylidene fluoride, vinyl fluoride, chlorotrifluoroethylene, etc.) and fluoropropylenes (hexafluoropropylene (HFP), 2-hydropentafluoropropylene, etc.).

[0025] The monomer (a2) is preferably a monomer with n = 2 to 6, and more preferably a monomer with n = 2 to 4. Furthermore, a monomer in which X is a fluorine atom and Y is a hydrogen atom, i.e., (perfluoroalkyl)ethylene, is preferred. The following compounds are specific examples of monomers (a2). CF3CF2CH=CH2, CF3CF2CF2CF2CH=CH2((Perfluorobutyl)ethylene (PFBE)), CF3CF2CF2CF2CF=CH2, CF2HCF2CF2CF=CH2, CF2HCF2CF2CF2CF=CH2 etc.

[0026] Specific examples of monomers (a3) ​​include the following compounds. Of these, the diene monomers are monomers that can undergo cyclopolymerization. CF2 = CFOCF3, CF2 = CFOCF2CF3, CF2 = CFO(CF2)2CF3 (perfluoro(propyl vinyl ether) (PPVE)), CF2=CFOCF2CF(CF3)O(CF2)2CF3, CF2 = CFO(CF2)3O(CF2)2CF3, CF2=CFO(CF2CF(CF3)O)2(CF2)2CF3, CF2=CFOCF2CF(CF3)O(CF2)2CF3, CF2=CFOCF2CF=CF2, CF2 = CFO(CF2)2CF = CF2, etc.

[0027] Specific examples of monomers (a4) include the following compounds. CF2 = CFO(CF2)3CO2CH3, CF2=CFOCF2CF(CF3)O(CF2)3CO2CH3, CF2=CFOCF2CF(CF3)O(CF2)2SO2F etc.

[0028] Specific examples of monomers (a5) include perfluoro(2,2-dimethyl-1,3-dioxol), 2,2,4-trifluoro-5-trifluoromethoxy-1,3-dioxol, and perfluoro(2-methylene-4-methyl-1,3-dioxolane).

[0029] Examples of monomers that do not contain a fluorine atom include the following monomers (b1) to (b4). Monomer (b1): Olefins. Monomer (b2): Vinyl esters. Monomer (b3): ​​Vinyl ethers. Monomer (b4): unsaturated acid anhydride.

[0030] Specific examples of monomers (b1) include propylene and isobutene. Specific examples of monomers (b2) include vinyl acetate, etc. Specific examples of monomers (b3) include ethyl vinyl ether, butyl vinyl ether, cyclohexyl vinyl ether, and hydroxybutyl vinyl ether. Specific examples of monomers (b4) include maleic anhydride, itaconic anhydride, citraconic anhydride, and 5-norbornene-2,3-dicarboxylic acid anhydride.

[0031] The third monomer may be used alone or in combination of two or more types. As a third monomer, from the viewpoint of ease of adjusting the degree of crystallinity and excellent tensile strength and elongation at high temperatures (especially around 180°C), monomer (a2), HFP, PPVE, and vinyl acetate are preferred, HFP, PPVE, CF3CF2CH=CH2, and PFBE are more preferred, and PFBE is even more preferred. In other words, as ETFE, a copolymer having units based on TFE, units based on E, and units based on PFBE is preferred.

[0032] In ETFE, the molar ratio of TFE units to E units (TFE units / E units) is preferably 80 / 20 to 40 / 60, more preferably 70 / 30 to 45 / 55, and even more preferably 65 / 35 to 50 / 50. When the TFE units / E units are within the above range, ETFE exhibits excellent heat resistance and mechanical strength.

[0033] The proportion of units based on the third monomer in ETFE is preferably 0.01 to 20 mol%, more preferably 0.10 to 15 mol%, and even more preferably 0.20 to 10 mol%, relative to the total amount of all units constituting ETFE (100 mol%). When the proportion of units based on the third monomer is within the above range, ETFE exhibits excellent heat resistance and mechanical strength.

[0034] When the units based on the third monomer include PFBE units, the proportion of PFBE units is preferably 0.5 to 4.0 mol%, more preferably 0.7 to 3.6 mol%, and even more preferably 1.0 to 3.6 mol%, relative to the total amount of all units constituting ETFE (100 mol%). When the proportion of PFBE units is within the above range, the tensile modulus of the film at 180°C can be adjusted to within the above range. In addition, the tensile strength and elongation at high temperatures, especially around 180°C, are improved.

[0035] The base material may consist solely of a release resin, or it may further contain other components in addition to the release resin. Examples of other components include lubricants, antioxidants, antistatic agents, plasticizers, and release agents. From the viewpoint of minimizing mold contamination, it is preferable that the base material does not contain other components.

[0036] The thickness of the base material is preferably 10 to 500 μm, more preferably 25 to 250 μm, and even more preferably 25 to 125 μm. If the thickness of the base material is below the upper limit of the above range, the film can be easily deformed and has excellent mold conformability. If the thickness of the base material is above the lower limit of the above range, the film can be easily handled, for example, in roll-to-roll applications, and wrinkles are less likely to occur when the film is stretched. The thickness of the substrate can be measured in accordance with ISO 4591:1992 (JIS K7130:1999) Method B1 (method for measuring thickness by mass of a sample taken from a plastic film or sheet). The same method applies to the thickness of each layer of the film.

[0037] The surface of the substrate may have surface roughness. The arithmetic mean roughness Ra of the substrate surface is preferably 0.2 to 3.0 μm, and more preferably 0.5 to 2.5 μm. If the arithmetic mean roughness Ra of the substrate surface is above the lower limit of the above range, the release properties are better. If the arithmetic mean roughness Ra of the substrate surface is below the upper limit of the above range, pinholes are less likely to form in the film. The arithmetic mean roughness Ra is measured according to JIS B0601:2013 (ISO 4287:1997, Amd.1:2009). The reference length lr (cutoff value λc) for the roughness curve is 0.8 mm.

[0038] The film disclosed herein preferably has an O / C ratio in the range of 0.010 to 0.200 in surface chemical composition analysis of the antistatic layer side of the substrate by X-ray photoelectron spectroscopy (hereinafter also referred to as "XPS"). When the O / C is within the above range, excellent antistatic performance tends to be obtained. The O / C ratio may also be 0.030 to 0.150 or 0.040 to 0.100. In the film according to the third embodiment of this disclosure, the O / C ratio is in the range of 0.010 to 0.200.

[0039] In the film disclosed herein, surface chemical composition analysis of the antistatic layer side of the substrate by XPS preferably shows an N / F ratio in the range of 0.010 to 0.100. When the N / F ratio is within this range, excellent antistatic performance tends to be obtained. The N / F ratio may also be 0.010 to 0.090 or 0.010 to 0.080. In the film according to the fourth embodiment of this disclosure, the N / F ratio is in the range of 0.010 to 0.100.

[0040] In one embodiment, it is also preferable to satisfy both the aforementioned ranges of O / C and the aforementioned ranges of N / F.

[0041] XPS is a method for quantifying the amount of elements present on material surfaces, and it is possible to quantify each element, such as carbon (C), oxygen (O), fluorine (F), and nitrogen (N). In O / C and N / F measurements, the analyte in XPS is measured at a depth of 2 to 8 nm from the surface of the object being measured. The information on the analytical instrument and analytical conditions are as follows.

[0042] Analytical instrument: Quantera PHI manufactured by ULVAC-PHI X-ray source: Al Kα 14kV Beam diameter: 100 μmΦ Measurement field of view: 800 × 300 μm 2 Measurement mode: Narrow spectrum measurement Measurement range and cumulative number of elements and their bond energies: C1s: 278~297eV, accumulated twice. O1s: 525-544 eV, cumulative over 3 measurements. N1s: 392~411eV, accumulated over 8 cycles. F1s: 680~699eV, one-time accumulation Pass energy: 224.0 eV Energy step: 0.4 eV Number of cycles: 8 cycles Neutralizing gun: Use Angle between detector and sample surface: 45°

[0043] In N / F and O / C measurements, the target elements in XPS measurements are the four elements C, O, F, and N. The proportion of F and N in the total amount (unit: Atomic%) is used as the amount of each atom. Then, N / F and O / C are determined based on the Atomic% values.

[0044] The substrate surface adjacent to other layers may be subjected to any surface treatment. Examples of surface treatments include corona treatment, plasma treatment, silane coupling agent coating, and adhesive application. From the viewpoint of adhesion between the substrate and other layers, corona treatment or plasma treatment is preferred.

[0045] From the viewpoint of adhesion to adjacent layers on the substrate, it is preferable that the surface of the substrate facing the antistatic layer be plasma-treated. It has also been found that plasma treatment tends to improve the antistatic performance of the film.

[0046] The conditions for plasma treatment are not particularly limited. In one embodiment, the plasma treatment may be carried out in the presence of argon (Ar) gas; ammonia (NH3) gas; or nitrogen (N2) gas, which may or may not be mixed with 10 volume% or less of hydrogen (H2) gas. When plasma treatment is performed in the presence of argon gas, functional groups such as hydroxyl groups, carbonyl groups, and carboxyl groups can be introduced to the substrate surface. When plasma treatment is performed in the presence of ammonia gas, functional groups such as hydroxyl groups, carbonyl groups, carboxyl groups, amino groups, and amide groups can be introduced to the substrate surface. When plasma treatment is performed in the presence of nitrogen gas, functional groups such as amino groups and amides can be introduced to the substrate surface. Furthermore, if the nitrogen gas is mixed with hydrogen gas at a concentration of 10% by volume or less, functional groups such as amino groups and amides can be introduced even more efficiently. As a result, the N / F ratio of the substrate surface may be adjusted to be within the aforementioned range, or the O / C ratio of the substrate surface may be adjusted to be within the aforementioned range, or both. When hydrogen gas is mixed with nitrogen gas, the concentration of hydrogen gas may be 0.01 to 10% by volume, may be 1 to 10% by volume, or may be 1 to 5% by volume.

[0047] In the plasma treatment, it is preferable to use atmospheric pressure (about 760 torr) or low-pressure conditions reduced from atmospheric pressure for the pressure of the atmosphere. The lower the pressure, the smaller the power consumption for plasma generation. On the other hand, from the viewpoint of making the generated plasma concentration sufficient, it is preferable that the pressure is not too low. From the above viewpoints, the pressure of the atmosphere in the plasma treatment may be 0.001 to 760 torr, may be 0.05 to 10 torr, or may be 0.05 to 1 torr.

[0048] In terms of easily introducing appropriate functional groups to the substrate, the discharge power in the plasma treatment may be 0.1 to 150 kW, may be 0.5 to 120 kW, may be 1 to 100 kW, or may be 1 to 50 kW.

[0049] In one aspect, the plasma treatment is performed such that the W·t / F (W·seconds / (m 3 / second)) calculated from the discharge power (W), treatment time (t), and gas flow rate (F) is in the range of 0.3×10 12 to 60.0×10 12 It may also be performed in the range of 0.5×10 12 to 40.0×10 12 or may be performed in the range of 1.0×10 12 to 10.0×10 12 When W·t / F is in the above range, it is easy to introduce appropriate functional groups to the substrate, and a better antistatic performance tends to be obtained.

[0050] The substrate surface may be subjected to corona treatment in addition to plasma treatment, or it may be subjected to corona treatment before plasma treatment. It has been observed that the strength of the substrate tends to be better when corona treatment is performed before plasma treatment. The reason for this is not clear, but it is presumed that even if the plasma intensity is relatively high during plasma treatment, the prior corona treatment suppresses the decomposition of the material on the substrate surface.

[0051] The contact angle of the surface of the substrate on the antistatic layer side is preferably 50 to 100°, but may also be 60 to 100° or 70 to 100°. The contact angle is determined using a contact angle meter (for example, a DMs-401 contact angle meter manufactured by Kyowa Kagaku Co., Ltd.).

[0052] The base material may be a single layer or may have a multilayer structure. A multilayer structure may consist of multiple layers, each containing a release resin, stacked on top of each other. In this case, the release resins in each of the layers may be the same or different. From the viewpoint of mold conformability, tensile elongation, and manufacturing cost, a single layer base material is preferable.

[0053] <Antistatic layer> The antistatic layer is not particularly limited as long as it is a layer having an antistatic function. The antistatic layer may be provided on the substrate adjacent to the substrate, or it may be provided on the substrate via at least a third layer adjacent to the substrate.

[0054] The antistatic layer may contain an antistatic agent. Examples of antistatic agents include ionic liquids, conductive polymers, metal ion conductive salts, and conductive metal oxides. One type of antistatic agent may be used alone, or two or more types may be used in combination.

[0055] Conductive polymers are polymers in which electrons move and diffuse along the polymer backbone. Examples of conductive polymers include polyaniline polymers, polyacetylene polymers, poly(p-phenylene) polymers, polypyrrole polymers, polythiophene polymers, and polyvinylcarbazole polymers.

[0056] Examples of metal ion-conducting salts include lithium salt compounds.

[0057] Examples of conductive metal oxides include tin oxide, tin-doped indium oxide, antimond-doped tin oxide, phosphorus-doped tin oxide, zinc antimonate, and antimony oxide.

[0058] As an antistatic agent, from the viewpoint of excellent heat resistance and conductivity, at least one selected from the group consisting of polyaniline polymer, polyacetylene polymer, poly-p-phenylene polymer, polypyrrole polymer, polythiophene polymer, and polyvinylcarbazole polymer is preferred.

[0059] The antistatic agent is preferably dispersed in the resin binder. In other words, the antistatic layer is preferably a layer in which the antistatic agent is dispersed in the resin binder. As for the resin binder, one with heat resistance is preferred. For example, when the film is used in the semiconductor encapsulation process, one with heat resistance at approximately 180°C is preferred. From the viewpoint of excellent heat resistance, the resin binder preferably contains at least one selected from the group consisting of acrylic resin, silicone resin, urethane resin, polyester resin, polyamide resin, vinyl acetate resin, ethylene-vinyl acetate copolymer, ethylene-vinyl alcohol copolymer, chlorotrifluoroethylene-vinyl alcohol copolymer, and tetrafluoroethylene-vinyl alcohol copolymer. In particular, from the viewpoint of excellent mechanical strength, it is preferable to consist of at least one selected from the group consisting of acrylic resin, silicone resin, urethane resin, polyester resin, polyamide resin, vinyl acetate resin, ethylene-vinyl acetate copolymer, ethylene-vinyl alcohol copolymer, chlorotrifluoroethylene-vinyl alcohol copolymer, and tetrafluoroethylene-vinyl alcohol copolymer (for example, only acrylic resin). Furthermore, from the viewpoint of excellent heat resistance and dispersibility of antistatic agents, polyester resin and acrylic resin are preferred. In the antistatic layer, the resin binder may be crosslinked. When the resin binder is crosslinked, it has better heat resistance than when it is not crosslinked.

[0060] From the viewpoint of ensuring that the antistatic function is fully exercised, the amount of antistatic agent contained in the antistatic layer is preferably such that the surface resistance value of the film falls within the range described below. In one embodiment, when the antistatic layer is a layer in which an antistatic agent is dispersed in a resin binder, the content of the antistatic agent may be 3 to 50% by mass or 5 to 20% by mass relative to the resin binder. When the content of the antistatic agent is above the lower limit of the above range, the surface resistance value of the film tends to be within a suitable range. When the content of the antistatic agent is below the upper limit of the above range, the adhesion of the antistatic layer tends to be good.

[0061] The antistatic layer may contain additives other than antistatic agents. Examples of additives include lubricants, colorants, and coupling agents. Examples of lubricants include microbeads made of thermoplastic resin, fumed silica, and polytetrafluoroethylene (PTFE) fine particles. Examples of colorants include various organic and inorganic colorants, more specifically, cobalt blue, red iron oxide, cyanine blue, and the like. Examples of coupling agents include silane coupling agents and titanate coupling agents.

[0062] The thickness of the antistatic layer is preferably 0.05 to 3.0 μm, and more preferably 0.1 to 2.5 μm. When the thickness of the antistatic layer is above the lower limit of the above range, conductivity is exhibited and the antistatic function is excellent. When the thickness of the antistatic layer is below the upper limit of the above range, the stability of the production process, including the appearance of the coated surface, is excellent.

[0063] <Other layers> In this disclosure, the film only needs to comprise a substrate and an antistatic layer, and may or may not comprise other layers. Examples of other layers include an adhesive layer, a base layer, a gas barrier layer, a coloring layer, etc. These layers may be used individually or in combination of two or more types.

[0064] The following are examples of the film layer structure. However, the film layer structure of this disclosure is not limited to those shown below. (1) A film comprising a base material and an antistatic layer in this order. (2) A film comprising a base material, an antistatic layer, and an adhesive layer in this order. (3) A film in which, in either (1) or (2), a gas barrier layer, a colored layer, etc., is further provided at any position on the antistatic layer side of the substrate.

[0065] -Adhesive layer- The film may further comprise an adhesive layer. The adhesive layer is a layer that is tacky to other components. The material of the adhesive layer is not particularly limited. In one embodiment, the adhesive layer may contain a reaction-cured product of a hydroxyl group-containing (meth)acrylic polymer and a polyfunctional isocyanate compound. In this case, the hydroxyl group-containing (meth)acrylic polymer reacts with the polyfunctional isocyanate compound to crosslink and become a reaction-cured product. The adhesive layer may also be a reaction-cured product of a hydroxyl group-containing (meth)acrylic polymer, a polyfunctional isocyanate compound, and other components.

[0066] A hydroxyl group-containing (meth)acrylic polymer may be a copolymer having at least hydroxyl group-containing (meth)acrylate units and units different from said hydroxyl group-containing (meth)acrylate units.

[0067] Examples of monomers that form hydroxyl group-containing (meth)acrylate units include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 1,4-cyclohexanedimethanol monoacrylate, and 2-acryloyloxyethyl-2-hydroxyethyl phthalic acid. One monomer that forms a hydroxyl group-containing (meth)acrylate unit may be used alone, or two or more may be used in combination.

[0068] Monomers that form units different from hydroxyl group-containing (meth)acrylate units include (meth)acrylates without hydroxyl groups, (meth)acrylic acid, acrylonitrile, and macromers having unsaturated double bonds.

[0069] Examples of (meth)acrylates that do not have a hydroxyl group include alkyl (meth)acrylate, cyclohexyl (meth)acrylate, phenyl (meth)acrylate, toluyl (meth)acrylate, benzyl (meth)acrylate, 2-methoxyethyl (meth)acrylate, 3-methoxybutyl (meth)acrylate, glycidyl (meth)acrylate, 2-aminoethyl (meth)acrylate, 3-(methacryloyloxypropyl)trimethoxysilane, trifluoromethylmethyl (meth)acrylate, and 2-trifluoromethylethyl (meth)acrylate. Examples include 2-perfluoroethylethyl (meth)acrylate, 2-perfluoroethyl-2-perfluorobutylethyl (meth)acrylate, 2-perfluoroethyl (meth)acrylate, perfluoromethyl (meth)acrylate, diperfluoromethylmethyl (meth)acrylate, 2-perfluoromethyl-2-perfluoroethylmethyl (meth)acrylate, 2-perfluorohexylethyl (meth)acrylate, 2-perfluorodecylethyl (meth)acrylate, and 2-perfluorohexadecylethyl (meth)acrylate.

[0070] As alkyl (meth)acrylates, compounds with 1 to 12 carbon atoms in the alkyl group are preferred, and examples include methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, n-pentyl (meth)acrylate, n-hexyl (meth)acrylate, n-heptyl (meth)acrylate, n-octyl (meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, and dodecyl (meth)acrylate.

[0071] Examples of macromers having unsaturated double bonds include macromers having polyoxyalkylene chains, such as (meth)acrylates of polyethylene glycol monoalkyl ethers.

[0072] The hydroxyl groups in hydroxyl group-containing (meth)acrylic polymers are crosslinking functional groups that react with isocyanate groups in polyfunctional isocyanate compounds. The hydroxyl value of the hydroxyl group-containing (meth)acrylic polymer is preferably 1 to 100 mg KOH / g, and more preferably 29 to 100 mg KOH / g. The hydroxyl value is measured by the method specified in JIS K0070:1992.

[0073] The hydroxyl group-containing (meth)acrylic polymer may or may not have a carboxyl group. The carboxyl group, like the hydroxyl group, is a crosslinking functional group that reacts with the isocyanate group in the polyfunctional isocyanate compound. The acid value of the hydroxyl group-containing (meth)acrylic polymer is preferably 0 to 100 mg KOH / g, and more preferably 0 to 30 mg KOH / g. The acid value is measured by the method specified in JIS K0070:1992, similar to the hydroxyl value.

[0074] The polyfunctional isocyanate compound is a compound having two or more isocyanate groups, and compounds having 3 to 10 isocyanate groups are preferred. Examples of polyfunctional isocyanate compounds include hexamethylene diisocyanate (HDI), tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), naphthalene diisocyanate (NDI), tolidine diisocyanate (TODI), isophorone diisocyanate (IPDI), xylene diisocyanate (XDI), triphenylmethane triisocyanate, and tris(isocyanatephenyl)thiophosphate. Furthermore, examples include isocyanurate (trimer) and biuret compounds of these polyfunctional isocyanate compounds, as well as adduct compounds of these polyfunctional isocyanate compounds with polyol compounds.

[0075] Polyfunctional isocyanate compounds are preferable to have an isocyanurate ring, as this allows the reaction-cured product (adhesive layer) to exhibit a high elastic modulus due to the planarity of the ring structure. Examples of polyfunctional isocyanate compounds having an isocyanurate ring include isocyanurate derivatives of HDI (isocyanurate-type HDI), isocyanurate derivatives of TDI (isocyanurate-type TDI), and isocyanurate derivatives of MDI (isocyanurate-type MDI).

[0076] When the adhesive layer is a reaction-cured product of an adhesive layer composition containing a hydroxyl group-containing acrylic polymer and a polyfunctional isocyanate compound, the content of the hydroxyl group-containing acrylic polymer and the polyfunctional isocyanate compound in the adhesive layer composition is M COOH / (M NCO -M OH ) becomes 0 to 1.0, M NCO / (M COOH +M OH It is preferable that ) be set to 0.4 to 3.5. Here, M OH M is the number of moles of hydroxyl groups derived from the hydroxyl group-containing acrylic polymer. COOH M is the number of moles of carboxyl groups derived from the hydroxyl group-containing acrylic polymer. NCO This represents the number of moles of isocyanate groups derived from the polyfunctional isocyanate compound.

[0077] M COOH / (M NCO -M OH ) is preferably 0 to 1.0, and more preferably 0 to 0.5. COOH / (M NCO -M OH If the value is greater than or equal to the lower limit of the range, it exhibits excellent adhesion to the contacting member. COOH / (M NCO -M OH When the value is below the upper limit of the aforementioned range, the amount of free carboxyl groups remaining in the adhesive layer decreases, resulting in excellent peelability from the contacting material.

[0078] M NCO / (M COOH +M OH ) is preferably 0.4 to 3.5, and more preferably 0.4 to 3.0. NCO / (M COOH +M OH When the value is above the lower limit of the range, the crosslinking density of the adhesive layer and, consequently, the elastic modulus become higher, resulting in excellent release and peelability from the contacting member. NCO / (M COOH +M OH If the value is below the upper limit of the aforementioned range, the elastic modulus of the adhesive layer will not become too high, resulting in excellent adhesion to the contacting material.

[0079] The total content of the hydroxyl group-containing acrylic polymer and the polyfunctional isocyanate compound in the adhesive layer composition is preferably 50% by mass or more, based on the total amount of the adhesive layer composition.

[0080] The adhesive layer may contain components such as crosslinking catalysts (amines, metal compounds, acids, etc.), reinforcing fillers, coloring dyes, pigments, and antistatic agents.

[0081] The thickness of the adhesive layer is preferably 0.05 to 3.0 μm, more preferably 0.05 to 2.5 μm, and even more preferably 0.05 to 2.0 μm. When the thickness of the adhesive layer is above the lower limit of the above range, the release properties are excellent. When the thickness of the adhesive layer is below the upper limit of the above range, the coating stability is excellent. Furthermore, when the thickness of the adhesive layer is below the upper limit of the above range, the tack after coating does not become too strong, making the continuous coating process easier.

[0082] A preferred example of an adhesive layer is the adhesive layer described in International Publication No. 2016 / 125796.

[0083] [Film manufacturing method] The film can be manufactured, for example, by applying a coating liquid for the antistatic layer to one surface of a substrate and drying it. Furthermore, desired layers other than the antistatic layer, such as an adhesive layer or a base layer, may be formed by coating. Heating may be used to accelerate the curing process during the formation of each layer.

[0084] In one embodiment, the method for manufacturing the film includes plasma treatment of the surface of a substrate, and providing an antistatic layer on the plasma-treated substrate, or providing an antistatic layer on the plasma-treated substrate with at least a third layer adjacent to the substrate in between, wherein surface chemical composition analysis of the substrate on the antistatic layer side after plasma treatment by XPS may satisfy an O / C ratio in the range of 0.010 to 0.200, an N / F ratio in the range of 0.010 to 0.100, or both. In this embodiment, an adhesive layer may be further provided on the side of the antistatic layer opposite to the substrate. Furthermore, the plasma treatment may be carried out in the presence of argon gas; ammonia gas; or nitrogen gas, which may or may not contain a mixture of argon gas or hydrogen gas at a concentration of 10% by volume or less. Furthermore, the method for manufacturing the film may further include corona treatment of the substrate surface in addition to plasma treatment, or further include corona treatment of the substrate surface before plasma treatment. Details of the plasma treatment and corona treatment in this embodiment are as described above.

[0085] [Characteristics of the film] (Adhesion of the antistatic layer) In the film disclosed herein, the antistatic layer has excellent adhesion, and as a result, excellent antistatic performance is expected to be obtained. In one embodiment, the following tape peel test is used as an indicator of adhesion. After uniaxial stretching to 300% at 25°C, cellophane tape (registered trademark) is pressed and adhered to the antistatic layer side of the film using a roller with a load of 4 kg for 5 back-and-forth passes. Within 5 minutes, the cellophane tape (registered trademark) is peeled off at a speed of 100 m / min in a direction 180° relative to the film, and the ratio of the peeled area of ​​the film to the adhesive area of ​​the cellophane tape (registered trademark) is obtained. Specifically, the tape peel test can be performed by the method described in the examples. The percentage of the peeling area is preferably less than 5%, more preferably 4% or less, even more preferably 3% or less, and may be 0%. In the first embodiment of this disclosure, the percentage of the peeling area is less than 5%. There are no specific requirements for the stretching speed in uniaxial stretching. Uniaxial stretching may be performed under a constant load or at a constant speed. In the case of stretching at a constant speed, it is preferable to stretch at a speed in the range of 0.0005 × Lm / min to 10 × Lm / min, and more preferably in the range of 0.001 × Lm / min to 10 × Lm / min, when the initial length of the stretched portion is Lm. In the case of stretching under a constant load, the rectangular film may be stretched up to 300% by methods such as fixing one side of the rectangular film to the top and hanging a weight on the other side that does not exceed the breaking strength, i.e., by creep deformation. If phenomena such as the film tearing occur during uniaxial stretching, the stretching conditions should be reviewed and the film stretched up to 300% should be extended.

[0086] In a further embodiment, the following wipe test is used as an indicator of adhesion. Without limiting the embodiments of this disclosure, the wipe test is conducted under relatively harsher conditions than the tape peel test described above. After uniaxial stretching to 300% at 25°C, the film is wiped by rubbing the surface of the antistatic layer side of the film 20 times back and forth with a nonwoven fabric (e.g., Bencot®) coated with acetone under a load of 4 kg. The haze is measured at the same location on the film before and after wiping, with the haze before wiping designated as H1 and the haze after wiping as H2. If the formula (H2-H1)≧0 is satisfied, it can be determined that there is no peeling after wiping and that good adhesion is present. Specifically, the wiping test can be performed by the method described in the examples. In the second embodiment of this disclosure, the formula (H2-H1)≧0 is satisfied. Preferably, the formula (H2-H1)≧1 is satisfied, and more preferably, the formula (H2-H1)≧3 is satisfied. While there is no particular upper limit to the formula (H2-H1), it is preferable that the evaluation is performed within the range that satisfies formula (H2-H1) ≤ 40, and more preferably that it satisfies formula (H2-H1) ≤ 30, from the viewpoint of avoiding misevaluation due to unexpected scratches on the film. The same conditions as those used in the tape peel test can be applied for uniaxial stretching.

[0087] (Tensile strength) The tensile strength of the film is preferably 35 MPa or higher, more preferably 40 MPa or higher, even more preferably 45 MPa or higher, and particularly preferably 50 MPa or higher. The tensile strength of the film is not particularly limited, but a higher value is preferable. The tensile strength of the film shall be measured in accordance with JIS K7127:1999. Specifically, it shall be measured by the method described in the examples.

[0088] (Surface resistance value) The surface resistance of the film is not particularly limited, 10 17 It may be less than or equal to Ω / □, and 10 11 Preferably Ω / □ or less, 10 10 Ω / □ or less is more preferable, 10 9 A value of Ω / □ or less is even more preferable. There is no particular lower limit to the surface resistance value. The surface resistance of the film is measured according to IEC 60093:1980: double-ring electrode method, with an applied voltage of 500V and an application time of 1 minute. For measuring instruments, for example, an ultra-high resistance meter R8340 (Advantec) can be used.

[0089] [Uses of film] The applications of the film disclosed herein are not particularly limited. For example, the film disclosed herein is useful as a release film used in the process of encapsulating semiconductor devices with a curable resin. Furthermore, because the film disclosed herein exhibits excellent antistatic properties even when stretched, it is also useful as a release film used in the process of manufacturing semiconductor packages with complex shapes, such as encapsulated bodies in which part of the electronic components are exposed from the encapsulating resin.

[0090] ≪Methods for manufacturing semiconductor packages≫ In one embodiment, a method for manufacturing a semiconductor package includes placing a film of the present disclosure on the inner surface of a mold, placing a substrate equipped with semiconductor elements in the mold on which the film is placed, sealing the semiconductor elements in the mold with a curable resin to produce a sealed body, and releasing the sealed body from the mold.

[0091] Examples of semiconductor packages include integrated circuits that integrate semiconductor elements such as transistors and diodes; and light-emitting diodes that have light-emitting elements. The package shape of an integrated circuit may cover the entire integrated circuit, or it may cover only a part of the integrated circuit, that is, leave a part of the integrated circuit exposed. Specific examples include BGA (Ball Grid Array), QFN (Quad Flat Non-leaded package), and SON (Small Outline Non-leaded package). From a productivity standpoint, semiconductor packages that are manufactured through batch encapsulation and singulation are preferred, and examples include integrated circuits and the like where the encapsulation method is MAP (Molded Array Packaging) or WL (Wafer Level packaging).

[0092] As the curable resin, thermosetting resins such as epoxy resins and silicone resins are preferred, and epoxy resins are more preferred.

[0093] In one embodiment, the semiconductor package may or may not have electronic components such as a source electrode and sealing glass in addition to the semiconductor element. Furthermore, some of the electronic components such as the semiconductor element, source electrode, and sealing glass may be exposed from the resin.

[0094] The method for manufacturing the semiconductor package can employ known manufacturing methods, except for the use of the film disclosed herein. For example, a transfer molding method can be used as a method for encapsulating the semiconductor element, and a known transfer molding apparatus can be used as the apparatus for this process. The manufacturing conditions can also be the same as those in known semiconductor package manufacturing methods. [Examples]

[0095] The embodiments of the present disclosure will now be described in detail by reference to examples, but the embodiments of the present disclosure are not limited to these examples. In the following examples, Examples 1-6, 13-15, and 18-23 are examples, and Examples 7-12, 16, and 17 are comparative examples.

[0096] The materials used to form each layer are as follows:

[0097] -Base material- • ETFE film 1: Fluon® ETFE LM720AXP (manufactured by AGC Inc.) was fed into an extruder equipped with a T-die, and taken up between a press roll with an uneven surface and a mirror-finish metal roll to produce a 50 μm thick film. The temperature of the extruder and T-die was 300°C, and the temperature of the press roll and metal roll was 90°C. The Ra of the surface of the obtained film was 2.2 μm on the press roll side and 0.1 μm on the mirror-finish side.

[0098] -Antistatic coating liquid- • Antistatic agent-containing material 1: Aracoat (registered trademark) AS601D (manufactured by Arakawa Chemical Industries, Ltd.), solids content 3.4% by mass, conductive polythiophene 0.4% by mass, acrylic resin 3.0% by mass • Hardener 1: Aracoat (registered trademark) CL910 (manufactured by Arakawa Chemical Industries, Ltd.), solids content 10% by mass, polyfunctional aziridine compound

[0099] -Coating liquid for adhesive layers- • (Meth)acrylic polymer 1: Nissetsu (registered trademark) KP2562 (manufactured by Nippon Carbide Industries Co., Ltd.), contains hydroxyl groups, does not contain carboxyl groups. • Polyfunctional isocyanate compound 1: Nissetsu CK157 (manufactured by Nippon Carbide Industries Co., Ltd.), 100% solids, isocyanurate-type hexamentiene diisocyanate, NCO content 21% by mass • Catalyst Dilution Solution 1: Nissetsu CK-920 (manufactured by Nippon Carbide Industries Co., Ltd.), acetylacetone dilution of dioctyl tin dilaurate, tin content 0.05%

[0100] The film was prepared using the following procedure.

[0101] [Pretreatment of the substrate] In the applicable examples listed in Tables 1 and 2, plasma treatment and, if necessary, corona treatment were performed on the ETFE film surface under the conditions described in Tables 1 and 2.

[0102] [Measurement of O / C and N / F] If necessary, the substrates that underwent the aforementioned pretreatment were subjected to O / C and N / F analysis by XPS. The target of the XPS analysis was a depth of 2 to 8 nm from the surface of the substrate. The information on the analytical instrument and analytical conditions is as follows.

[0103] Analytical instrument: Quantera PHI manufactured by ULVAC-PHI X-ray source: Al Kα 14kV Beam diameter: 100 μmΦ Measurement field of view: 800 × 300 μm 2 Measurement mode: Narrow spectrum measurement Measurement range and cumulative number of elements and their bond energies: C1s: 278~297eV, accumulated twice. O1s: 525-544 eV, cumulative over 3 measurements. N1s: 392~411eV, accumulated over 8 cycles. F1s: 680~699eV, one-time accumulation Pass energy: 224.0 eV Energy step: 0.4 eV Number of cycles: 8 cycles Neutralizing gun: Use Angle between detector and sample surface: 45°

[0104] The target elements for XPS measurement were the four elements C, O, F, and N. The proportion of F and N in the total amount of these elements (unit: Atomic%) was used as the amount of each atom. Subsequently, the O / C and N / F ratios were determined based on the Atomic% values.

[0105] [Preparation of an antistatic layer] A coating liquid for an antistatic layer with a solid content of 2% by mass was prepared by mixing 100 parts by mass of antistatic agent-containing material 1 and 10 parts by mass of hardener 1. The coating liquid for the antistatic layer was applied to the substrate surface using a gravure coater and dried to form an antistatic layer with a thickness of 0.2 μm. The coating was performed using a direct gravure method, with a Φ100 mm × 250 mm wide, 150# grid, 40 μm depth roll used as the gravure plate. Drying was performed at 55°C for 1 minute, passing through a roll-supported drying oven at an airflow of 19 m / s.

[0106] [Preparation of the adhesive layer] A coating solution for the adhesive layer was prepared by mixing 100 parts by mass of (meth)acrylic polymer 1, 6 parts by mass of polyfunctional isocyanate compound 1, 21 parts by mass of catalyst dilution solution 1, and ethyl acetate. The amount of ethyl acetate added was such that the solid content of the coating solution for the adhesive layer was 14% by mass. An adhesive coating liquid was applied to the surface of the antistatic layer using a gravure coater, and dried to form an adhesive layer with a thickness of 0.8 μm. The coating was performed using a direct gravure method, with a Φ100 mm × 250 mm wide, 150# grid, 40 μm depth roll used as the gravure plate. Drying was performed at 65°C for 1 minute, passing through a roll-supported drying oven, with an airflow of 19 m / s. Subsequently, the film was cured at 40°C for 48 hours to obtain the final film.

[0107] [Tape peel test] The film was cut to a shape of 150 mm in length and 50 mm in width, with the film formation direction (MD) oriented longitudinally. Next, a preliminary strain was applied using a Shimadzu Autograph AGC-X universal testing machine. First, a sample gripping jig with a 50 mm chuck width was attached, the distance between the chucks was set to 50 mm, and the previously cut film was mounted by evenly gripping both sides with the chuck jig to prevent wrinkles. Then, in a 25°C environment, the chucks were moved at a speed of 50 mm / min with a displacement of 150 mm to apply uniaxial stretching strain to the film (i.e., 300% stretch). Within 10 seconds after stretching, the chucks were removed, and the sample was left to stand for 15 minutes.

[0108] Nichiban cellophane adhesive tape "Cellotape (registered trademark)" CT-18 (width 18 mm) was first stretched and applied to the back of a 70 mm long piece in the uniaxial direction. It was then pressed and bonded five times back and forth with a 35 mm diameter, 40 mm wide plastic roller under a load of 4 kg. Within 5 minutes thereafter, the end of the bonded tape was held and peeled off at a speed of 100 m / min in a 180° direction relative to the film. The time required for peeling was approximately 0.4 seconds.

[0109] Subsequently, visual inspection was performed to evaluate the presence or absence of adhering substances on the tape's adhesive surface and the presence or absence of delamination of the coating on the film side. Films with delamination defects covering 5% or more of the film surface area were classified as "delamination present," while those with delamination defects covering less than 5% were classified as "no delamination."

[0110] [Swipe test] The film was cut to a shape of 150 mm in length and 50 mm in width, with the film formation direction (MD) oriented longitudinally. Next, a preliminary strain was applied using a Shimadzu Autograph AGC-X universal testing machine. First, a sample gripping jig with a 50 mm chuck width was attached, the distance between the chucks was set to 50 mm, and the previously cut film was mounted by evenly gripping both sides with the chuck jig to prevent wrinkles. Then, in a 25°C environment, the chucks were moved at a speed of 50 mm / min with a displacement of 150 mm to apply uniaxial stretching strain to the film (i.e., 300% stretch). Within 10 seconds after stretching, the chucks were removed, and the sample was left to stand for 15 minutes.

[0111] Next, optical measurements were taken at the location where stretching strain was applied, and the haze was measured. The haze H1 of the stretched portion was determined using a haze meter NDH5000 manufactured by Nippon Denshoku Industries Co., Ltd.

[0112] Next is Asahi Kasei's Bencot (registered trademark) M-3II (1 sheet, 1.6g, 23cm x 24cm, basis weight 28.9g / m²). 2 A nonwoven fabric was folded into four, impregnated with 10g of acetone, and the acetone-soaked nonwoven fabric was rubbed back and forth 20 times with a 4kg load from one finger. After that, the acetone adhering to the film was dried at 25°C for 15 minutes, and the haze was measured in the same area as the area measured before wiping to determine the haze H2.

[0113] If the change in haze value satisfies (H2-H1) ≥ 0, it was determined that the coating film was sufficiently retained on the substrate surface and that there was "no peeling". If the change in haze value satisfies (H2-H1) < 0, it was determined that there was "peeling".

[0114] [Adhesion Rank] Based on the results of the tape peel test and wipe test, the adhesion rank of the coating film produced in each example was set as follows. A: No peeling was observed in the tape peel test and wipe test. B: No peeling was observed in the tape peel test, but peeling was observed in the wipe test. C: Peeling was observed in the tape peel test and wipe test.

[0115] [Withstand voltage measurement] A 5mm x 5mm x 200μm thick semiconductor element, fixed to a 70mm x 230mm copper lead frame, was sealed using a sealing device (Transfer Molding Device G-LINE Manual System, manufactured by Apic Yamada Co., Ltd.). The epoxy resin composition described later was used as the sealing resin. Before the sealing process, a roll of 190mm wide film was set in a 250μm deep upper mold using a roll-to-roll method. After placing the lead frame with the semiconductor element fixed to it in the lower mold, the film was vacuum-suctioned onto the upper mold, the mold was clamped, and the curable resin was poured in. After pressurizing at 175°C for 5 minutes, the mold was opened and the sealed object was removed.

[0116] The epoxy resin composition was prepared by grinding and mixing the following components in a super mixer for 5 minutes. The glass transition temperature of the cured epoxy resin composition was 135°C, the storage modulus at 130°C was 6 GPa, and the storage modulus at 180°C was 1 GPa. • Phenylene skeleton-containing phenol aralkyl type epoxy resin (softening point 58°C, epoxy equivalent 277 g / eq) 8 parts by mass • Bisphenol A type epoxy resin (melting point 45°C, epoxy equivalent 172 g / eq) 2 parts by mass • Phenylene skeleton-containing phenol aralkyl resin (softening point 65°C, hydroxyl group equivalent 165 g / eq) 2 parts by mass • Phenol novolac resin (softening point 80°C, hydroxyl group equivalent 105 g / eq) 2 parts by mass, • Curing accelerator (triphenylphosphine) 0.2 parts by mass • Inorganic filler (molten spherical silica with median diameter of 16 μm): 84 parts by mass Carnauba wax 0.1 parts by mass • Carbon black 0.3 parts by mass • Coupling agent (3-glycidoxypropyltrimethoxysilane) 0.2 parts by mass

[0117] Using a sphere-planar electrode configuration as described in JIS K6911:2006, the sphere electrode was brought into contact with the location of the sealed semiconductor element, and a low-speed boost test was performed. Withstand voltage measurements were taken at a boost speed of 100 V / s. The test was conducted in air. A 6 mm diameter sphere and a 6 mm diameter cylindrical planar were used. A 100 kV dielectric breakdown tester YST-243-100RHO (Yamayo Test Equipment) was used for the measurements. A voltage withstand capability of 1.0kV or higher was judged as good (A), and a voltage withstand capability of less than 1.0kV was judged as poor (C).

[0118] [Measurement of tensile strength] Tensile tests were conducted at 25°C with a chuck speed of 100 mm / min using a Type V dumbbell in accordance with JIS K7127:1999. The breaking force was measured and converted to stress based on the initial sample cross-sectional area.

[0119] [Table 1]

[0120] [Table 2]

[0121] In Tables 1 and 2, the numbers in parentheses under "Plasma Treatment Conditions for Substrate" for "Treatment Environment" represent the H2 concentration (volume %) in the N2 / H2 mixed gas.

[0122] Examples 1-6, 13-15, and 18-23, in which no peeling was observed in the tape peeling test, demonstrate excellent dielectric strength. In particular, examples 1-6 and 18-23, in which no peeling was observed in the wipe test, show especially excellent dielectric strength.

[0123] Furthermore, it can be seen that examples 1-6, 13-15, and 18-23 exhibit superior withstand voltage performance when the O / C is in the range of 0.010 to 0.200, the N / F is in the range of 0.010 to 0.100, or both.

[0124] Comparing Example 1 and Example 5, there is a tendency for the tensile strength of the film to improve with corona treatment before plasma treatment. Furthermore, even when the intensity of the plasma treatment was increased in Example 6, good tensile strength was maintained by performing corona treatment beforehand.

[0125] The disclosure of Japanese Patent Application No. 2021-028909 is incorporated herein by reference in its entirety. All documents, patent applications, and technical standards described herein are incorporated by reference to the same extent as if each individual document, patent application, and technical standard were specifically and individually noted as being incorporated by reference. [Explanation of Symbols]

[0126] 1 film 2 Base material 3. Antistatic layer

Claims

1. The material comprises at least a base material and an antistatic layer, The aforementioned substrate comprises an ethylene-tetrafluoroethylene copolymer. The antistatic layer is a layer in which an antistatic agent is dispersed in a resin binder. The antistatic layer is provided on the substrate adjacent to the substrate, In surface chemical composition analysis of the antistatic layer side of the substrate by X-ray photoelectron spectroscopy, the O / C ratio is in the range of 0.010 to 0.200, the N / F ratio is in the range of 0.010 to 0.100, or both of these conditions are met. A film characterized in that, after uniaxial stretching to 300% at 25°C, the percentage of the peeled area when a tape peel test is performed under the following conditions is less than 5%. Using a roller, cellophane tape (registered trademark) is pressed and adhered to the antistatic layer side surface of the film with a load of 4 kg for five back-and-forth movements. Within 5 minutes, the cellophane tape (registered trademark) is peeled off from the film at a speed of 100 m / min in a direction 180°, and the ratio of the peeled area of ​​the film to the adhesive area of ​​the cellophane tape (registered trademark) is obtained.

2. The film according to claim 1, which satisfies formula (H2 - H1) ≥ 0 when a wipe test is performed under the following conditions after uniaxial stretching to 300% at 25°C. The film is wiped clean by rubbing the surface of the antistatic layer side of the film back and forth 20 times with a nonwoven fabric coated with acetone and a load of 4 kg. The haze is measured at the same location on the film before and after wiping, with the haze before wiping designated as H1 and the haze after wiping as H2.

3. The film according to claim 1 or 2, wherein, in surface chemical composition analysis of the antistatic layer side of the substrate by X-ray photoelectron spectroscopy, the O / C ratio is in the range of 0.010 to 0.

200.

4. The film according to any one of claims 1 to 3, wherein, in surface chemical composition analysis of the antistatic layer side of the substrate by X-ray photoelectron spectroscopy, the N / F ratio is in the range of 0.010 to 0.

100.

5. The material comprises at least a base material and an antistatic layer, The aforementioned substrate comprises an ethylene-tetrafluoroethylene copolymer. The antistatic layer is a layer in which an antistatic agent is dispersed in a resin binder. The antistatic layer is provided on the substrate adjacent to the substrate, In the surface chemical composition analysis of the antistatic layer side of the substrate by X-ray photoelectron spectroscopy, the N / F ratio is in the range of 0.010 to 0.

100. A film characterized by satisfying the formula (H2 - H1) ≥ 0 when a wipe test is performed under the following conditions after uniaxial stretching to 300% at 25°C. The film is wiped clean by rubbing the surface of the antistatic layer side of the film back and forth 20 times with a nonwoven fabric coated with acetone and a load of 4 kg. The haze is measured at the same location on the film before and after wiping, with the haze before wiping designated as H1 and the haze after wiping as H2.

6. The film according to claim 5, wherein, in surface chemical composition analysis of the antistatic layer side of the substrate by X-ray photoelectron spectroscopy, the O / C ratio is in the range of 0.010 to 0.

200.

7. The material comprises at least a base material and an antistatic layer, The aforementioned substrate comprises an ethylene-tetrafluoroethylene copolymer. The antistatic layer is a layer in which an antistatic agent is dispersed in a resin binder. The antistatic layer is provided on the substrate adjacent to the substrate, A film characterized in that, in surface chemical composition analysis of the antistatic layer side of the substrate by X-ray photoelectron spectroscopy, the O / C ratio is in the range of 0.010 to 0.

200.

8. The film according to claim 7, wherein, in surface chemical composition analysis of the antistatic layer side of the substrate by X-ray photoelectron spectroscopy, the N / F ratio is in the range of 0.010 to 0.

100.

9. The material comprises at least a base material and an antistatic layer, The aforementioned substrate comprises an ethylene-tetrafluoroethylene copolymer. The antistatic layer is a layer in which an antistatic agent is dispersed in a resin binder. The antistatic layer is provided on the substrate adjacent to the substrate, A film characterized in that, in surface chemical composition analysis of the antistatic layer side of the substrate by X-ray photoelectron spectroscopy, the N / F ratio is in the range of 0.010 to 0.

100.

10. The film according to any one of claims 1 to 9, wherein the surface of the substrate facing the antistatic layer is plasma treated.

11. The film according to any one of claims 1 to 10, wherein the substrate further comprises at least one selected from the group consisting of polymethylpentene, syndiotactic polystyrene, and polycycloolefin.

12. The film according to any one of claims 1 to 11, wherein the substrate further comprises at least one selected from the group consisting of tetrafluoroethylene-hexafluoropropylene copolymer, tetrafluoroethylene-perfluoro(alkyl vinyl ether) copolymer, and tetrafluoroethylene-hexafluoropropylene-vinylidene fluoride copolymer.

13. The film according to any one of claims 1 to 12, further comprising an adhesive layer on the surface of the antistatic layer opposite to the substrate.

14. A release film used in a process of encapsulating a semiconductor element with a curable resin, as described in any one of claims 1 to 13.

15. Plasma treatment of the substrate surface, A static-resistant layer is provided on the plasma-treated substrate, Includes, The aforementioned substrate comprises an ethylene-tetrafluoroethylene copolymer. The antistatic layer is a layer in which an antistatic agent is dispersed in a resin binder. A method for manufacturing a film, characterized in that, in surface chemical composition analysis of the antistatic layer side of the substrate after plasma treatment by X-ray photoelectron spectroscopy, the O / C ratio is in the range of 0.010 to 0.200, the N / F ratio is in the range of 0.010 to 0.100, or both.

16. The method for producing a film according to claim 15, wherein the plasma treatment is carried out in the presence of argon gas, ammonia gas, or nitrogen gas which may or may not contain 10% by volume of hydrogen gas.

17. The method for manufacturing a film according to claim 15 or 16, further comprising corona treatment of the surface of the substrate before the plasma treatment.

18. A method for manufacturing a film according to any one of claims 15 to 17, further comprising providing an adhesive layer on the surface of the antistatic layer opposite to the substrate.

19. The film described in any one of claims 1 to 14 or the film manufactured by the manufacturing method described in any one of claims 15 to 18 is placed on the inner surface of the mold, A substrate comprising a semiconductor element is placed within the mold in which the aforementioned film is arranged. The semiconductor element in the mold is sealed with a curable resin to produce a sealed body, The sealing body is released from the mold, A method for manufacturing a semiconductor package, characterized by including the following:

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