Laminated film, method for producing semiconductor, and semiconductor

Abstract

This laminated film includes: a base material film containing at least polyester as a main component; and a release layer. The center surface average roughness SRa of at least one surface of the laminated film is 0.01 μm to 20.0 μm. The center surface average roughness SRa measured from at least one release layer-side surface of the laminated film decreases at least 50.0% after hot pressing by the following method, compared to the value before hot pressing. Provided is a film that can prevent foreign matter from infiltrating into a pressing region while having superior deaeration characteristics, such as vacuum adsorption.

Description

Laminated film, semiconductor manufacturing method, and semiconductor

[0001] This invention relates to a laminated film, a method for manufacturing a semiconductor, and a semiconductor.

[0002] Polyester film is widely used as a base film in many applications, such as magnetic recording materials and packaging materials, due to its excellent mechanical, electrical, dimensional stability, transparency, and chemical resistance. In recent years, in particular, there has been increasing demand for it as a carrier film, including films for printed circuit board manufacturing and release films for semiconductor molds.

[0003] Printed circuit boards (PCBs) having multilayer conductive circuits are formed by laminating multiple layers of conductive circuits with numerous via holes and prepregs made of glass cloth impregnated with epoxy resin or the like for insulation, adhesion, and conductor protection. The general manufacturing process for PCBs involves placing a PCB laminate between two layers of a multilayer PCB manufacturing film (carrier film) with excellent peelability, and transporting the PCB laminate on this carrier film. The laminate is then integrated through a series of processes including heated vacuum pressing and high-pressure heated pressing. After the heated vacuum pressing and high-pressure heated pressing processes, the multilayer PCB manufacturing film (carrier film) is peeled off the PCB laminate and wound up. The required properties for the carrier film include peelability, particle shedding resistance, and dimensional stability. Studies have been conducted to ensure that the film does not produce processing wrinkles and has good transportability under a wide range of processing conditions, such as heated vacuum pressing and high-pressure heated pressing, used in the manufacturing of PCBs (Patent Document 1).

[0004] Also, the semiconductor chip is encapsulated with resin for the purpose of protecting it from disturbances such as light, heat, moisture, and physical impact, and is mounted on a substrate as a molded product called a package. For encapsulating the semiconductor chip, a curable resin such as an epoxy resin is used. As a method for encapsulating the semiconductor chip, so-called transfer molding (resin injection molding) or compression molding is known. In recent years, due to trends in shapes such as increasing the area of semiconductor wafers, thinning of packages, and multi-pinning to increase input terminals, the introduction of compression molding has been progressing.

[0005] The compression molding method is a method in which the molten encapsulation resin is compressed and cured by the up-and-down movement of the mold in a heated state, and it is used as a manufacturing method for a packaging technology called wafer-level chip-size package (WL-CSP) that packages wafers in a batch. At this time, in order to ensure the mold release property between the mold and the encapsulation resin, a method of inserting a laminated film is common. As the laminated film, a film of ethylene-tetrafluoroethylene copolymer (ETFE) that is excellent in mold release property, heat resistance, and followability to the mold shape is widely used (Patent Document 2).

[0006] In recent years, due to technological trends such as increasing the area of semiconductor wafers, lowering the height of packages, high integration, 3D stacking, and functional integration, the introduction of the compression molding method has been progressing, and fan-out wafer-level packaging (FO-WLP) has been expanding by the technology of forming a redistribution layer (RDL). Fig. 1 shows a schematic diagram of the face-up type compression molding process for manufacturing FO-WLP. As a release film corresponding to these latest packaging technologies, a release film for compression molding with excellent design and moldability has been studied (Patent Document 3).

[0007] Among polyester films, in the case of a release film having a polyethylene terephthalate (PET) film with excellent dimensional stability as a base material, it is necessary to provide a release layer separately from the base film. A release film that mainly laminates polyethylene terephthalate as a heat-resistant resin layer and polymethylpentene as a release layer to improve air venting properties during vacuum adsorption has been studied (Patent Document 4).

[0008] Japanese Patent Application Laid-Open No. 2017-110121 International Publication No. 2015 / 068808 Japanese Patent Application Laid-Open No. 2023-59203 International Publication No. 2023 / 047977

[0009] The polyester film described in Patent Document 1 is a film in which irregularities are formed by adding particles with a size of 4 μm to a polyethylene terephthalate resin. When used as a carrier film, although the air venting property during heating vacuum pressing is good, there is a problem that the solder resist or the epoxy resin, which is an adhesive, penetrates from the end before curing due to the existence of gaps in the irregularities during pressing, contaminating the circuit board.

[0010] In addition, in the latest semiconductor packaging technology, in addition to the flange molding where the mold resin remains inside the upper part of the wafer, a full molding method in which the thickness of the mold resin is 1.0 mm or more and the mold resin is filled up to the outside of the wafer is used to improve the yield. In the full molding method, as shown in FIG. 2, since the mold resin may contact the lower surface of the mold, a release film is also arranged on the lower side of the substrate to prevent contamination of the lower mold by the mold resin. The release film on the lower side of the wafer is required to have vacuum adsorption properties for wafer fixing. When using the films of Patent Documents 2 to 4, although there is no problem with vacuum adsorption properties due to surface irregularities, there is a problem that the mold resin penetrates to the lower side of the wafer due to the surface irregularities of the film, contaminating a part of the back side of the wafer and deteriorating the yield.

[0011] Therefore, the problem in the present invention is to provide a film that has characteristics excellent in degassing such as vacuum adsorption properties and can prevent foreign matter from penetrating into the pressing area.

[0012] To solve the above problems, a preferred embodiment of the present invention has the following configuration: 1. A laminated film having a base film mainly composed of polyester and a release layer, wherein the mean center surface roughness SRa of at least one surface of the laminated film is 0.01 μm or more and 20.0 μm or less, and the mean center surface roughness SRa measured from at least one surface on the release layer side of the laminated film is reduced by 50.0% or more after heating and pressing using the following method. (Heating and pressing method) Using a press machine heated to a temperature of 125°C for both the upper and lower molds, a three-layer structure of "SUS304 plate with a thickness of 0.5 mm and an arithmetic mean roughness Ra of 0.1 μm" / laminated film / "SUS304 plate with a thickness of 0.5 mm and an arithmetic mean roughness Ra of 0.1 μm" is placed between the upper and lower molds. The SUS304 plate used shall be hairline-finished and have a maximum height Rz (JIS B0601-2001) of 2 μm or less. A preheating time of 5 minutes shall be set, followed by a 10-minute heating press under 4.0 MPa conditions. 2. The number of protrusions with a height of 0.3 μm to 1.6 μm, measured from at least one release layer surface of the laminated film, shall be 50 per 80089 μm. ２ More than 5000 pieces / 80089μm ２1. The laminated film described below. 3. The laminated film described in 1. or 2., wherein the mean center surface roughness SRa measured from at least one release layer side surface of the laminated film is 1.7 μm or more and 10.0 μm or less. 4. The laminated film described in any of 1. to 3., wherein the mean center surface roughness SRa on at least one release layer side surface of the laminated film is 1.0 μm or more lower after heating and pressing using the following method. (Heating and pressing method) Using a press machine heated to 125°C for both the upper and lower mold temperatures, a three-layer structure consisting of "SUS304 plate with a thickness of 0.5 mm and an arithmetic mean roughness Ra of 0.1 μm" / laminated film / "SUS304 plate with a thickness of 0.5 mm and an arithmetic mean roughness Ra of 0.1 μm" is placed between the upper and lower molds. The SUS304 plate used shall be hairline-finished and have a maximum height Rz (JIS B0601-2001) of 2 μm or less. After a preheating time of 5 minutes, heat pressing shall be performed for 10 minutes under conditions of 4.0 MPa. 5. The number of protrusions SPc with a protrusion height of 0.4 μm or more and less than 2.0 μm, measured from at least one release layer side surface of the laminated film, shall be 20 per mm. ２ More than 100 pieces / mm ２ A laminated film according to any of the following 1. to 4. 6. A laminated film according to any of the following 1. to 5. wherein the base film has a laminated structure including at least a main layer A and a sub-layer B. 7. A laminated film according to 6. wherein the surface orientation coefficient of the sub-layer B of the base film is 0.15 or more and 0.17 or less. 8. A laminated film according to any of the following 1. to 7. wherein in the tanδ-temperature curve obtained from dynamic viscoelasticity measurement under the following measurement conditions, there are two peaks, with the low-temperature peak being Peak A and the high-temperature peak being Peak B, the peak top temperature of Peak A is less than 100°C and the peak top temperature of Peak B is 100°C or more. (Dynamic viscoelasticity measurement conditions) Heating temperature: 20°C to 200°C Heating rate: 3°C / min Sampling frequency: 1 second Measurement frequency: 1 Hz 9. Bending stiffness in the MD direction and TD direction is 10 × 10 －３ N・mm ２ The above 150 x 10 －３ N・mm ２The laminated film according to any one of 1. to 8. below. 10. The laminated film according to any one of 1. to 9. having a puncture strength measured by the method described in JIS Z1707 (1997) of 2 N or more and 5 N or less. 11. The laminated film according to any one of 1. to 10. used as a laminated film for semiconductor compression molding. 12. A laminated film having a base film mainly composed of at least polyester and a release layer, wherein the center plane average roughness SRa of at least one surface of the laminated film is 0.01 μm or more and 20.0 μm or less, and for the center plane average roughness SRa measured from at least one release layer side surface of the laminated film, a process of using a laminated film in which the value after heat pressing by the following method is reduced by 50.0% or more compared to the value before heat pressing. (Heat pressing method) Use a press machine heated to a temperature of 125°C for both the upper mold temperature and the lower mold temperature, and install a three-layer structure of "SUS304 plate with a thickness of 0.5 mm and an arithmetic mean roughness Ra of 0.1 μm" / laminated film / "SUS304 plate with a thickness of 0.5 mm and an arithmetic mean roughness Ra of 0.1 μm" between the upper and lower molds. The SUS304 plate used is hairline finished and has a maximum height Rz (JIS B0601-2001) of 2 μm or less. Set the preheating time to 5 minutes and perform heat pressing for 10 minutes under the condition of 4.0 MPa. 13. The method for manufacturing a semiconductor according to 12., including a step of covering the semiconductor element with a mold resin. 14. The temperature of the mold resin used in the step of covering the semiconductor element with the mold resin is 25°C, and the shear rate is 2.5 s －１ The method for manufacturing a semiconductor according to 13., having a viscosity of 70 Pa·s or more and 1000 Pa·s or less at. 15. A semiconductor molded with a mold resin, wherein the thickness of the mold resin is 0.1 mm or more and 3.0 mm or less, and the element area of the semiconductor is 100 mm ２ or more and 250000 mm ２The semiconductor is as follows, wherein multiple semiconductor elements are connected via an interposer to form a single semiconductor, and the in-plane thickness uniformity standard deviation of the semiconductor is 0.05 μm or more and 1.0 μm or less. 16. The semiconductor according to 15, wherein the mold resin is a mold resin in which a spectrum originating from dimethylsiloxane ions is detected by the following measurement method. (Measurement method for mold resin) Apparatus: TOF.SIMS 5 (manufactured by IONTOF) Primary ion: Bi ３＋＋ Secondary ion polarity: Negative only Etching ion: Ar Gas cluster ion beam (Ar-GCIB) 17. A laminated film having a base film and a release layer, wherein the average center surface roughness SRa of at least one surface of the laminated film is 0.01 μm or more and 20.0 μm or less, and the average center surface roughness SRa measured from at least one surface of the laminated film on the release layer side is reduced by 50.0% or more after heating and pressing by the following method, and the bending stiffness in the MD direction and TD direction is 10 × 10 －３ N・mm ２ The above 150 x 10 －３ N・mm ２ The laminated film is as follows. (Heating press method) Using a press machine with both the upper and lower die temperatures heated to 125°C, a three-layer structure consisting of "SUS304 plate with a thickness of 0.5 mm and an arithmetic mean roughness Ra of 0.1 μm" / laminated film / "SUS304 plate with a thickness of 0.5 mm and an arithmetic mean roughness Ra of 0.1 μm" is placed between the upper and lower dies. The SUS304 plate used is hairline finished and has a maximum height Rz (JIS B0601-2001) of 2 μm or less. With a preheating time of 5 minutes, heating press is performed for 10 minutes under conditions of 4.0 MPa.

[0013] According to the present invention, it is possible to provide a film that has excellent degassing properties, such as vacuum adsorption, while preventing foreign matter from seeping into the press area.

[0014] This is a schematic cross-sectional diagram of the face-up compression molding process used to manufacture FO-WLP. This is a schematic cross-sectional diagram of the face-up compression molding process used to manufacture FO-WLP full molds. This is a schematic diagram of the tent diameter. This is a schematic diagram of the penetration of molding resin into the back side of the wafer after full molding.

[0015] The laminated film in the present invention is a laminated film having a base film mainly composed of polyester and a release layer provided on the base film. The release layer is preferably a resin layer located on at least one surface, and on that surface, the water contact angle measured by the method described later is 85° or more.

[0016] <Composition and Structure of the Base Film> The base film in this invention has polyester as its main component. Here, having polyester as its main component means that polyester resin is contained in an amount greater than 70% by mass of the components that make up the base film.

[0017] Polyesters can be obtained by 1) polycondensation of a dicarboxylic acid or its ester-forming derivative (hereinafter collectively referred to as "dicarboxylic acid component") and a diol component or its ester-forming derivative (hereinafter collectively referred to as "diol component"), 2) polycondensation of a compound having a carboxylic acid or carboxylic acid derivative and a hydroxyl group in one molecule, or a combination of 1) and 2).

[0018] 1) In this case, the dicarboxylic acid components include aliphatic dicarboxylic acids such as malonic acid, succinic acid, glutaric acid, adipic acid, suberic acid, sebacic acid, dodecanedionic acid, dimer acid, eicosanedionic acid, pimelic acid, azelaic acid, methylmalonic acid, and ethylmalonic acid; alicyclic dicarboxylic acids such as adamantanedicarboxylic acid, norbornenedicarboxylic acid, cyclohexanedicarboxylic acid, and decalindicarboxylic acid; terephthalic acid, isophthalic acid, phthalic acid, 1,4-naphthalenedicarboxylic acid, and 1,5-naphtha. Examples of typical aromatic dicarboxylic acids include lendicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 1,8-naphthalenedicarboxylic acid, 4,4'-diphenyldicarboxylic acid, 4,4'-diphenyletherdicarboxylic acid, 4,4'-diphenylsulfondicarboxylic acid, 5-sodium sulfisophthalic acid, phenylendanedicarboxylic acid, anthracenedicarboxylic acid, phenantradiocarboxylic acid, 9,9'-bis(4-carboxyphenyl)fluorenic acid, and their ester derivatives. These can be used individually or in combination.

[0019] Furthermore, dicarboxyl compounds can also be used, which are obtained by condensing l-lactide, d-lactide, hydroxybenzoic acid, and their derivatives, or a combination of multiple oxyacids, at least one carboxyl terminus of the aforementioned dicarboxylic acid component.

[0020] Next, typical examples of diol components include aliphatic diols such as ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,2-butanediol, and 1,3-butanediol; alicyclic diols such as cyclohexanedimethanol, spiroglycol, and isosorbide; and aromatic diols such as bisphenol A, 1,3-benzenedimethanol, 1,4-benzenedimethanol, and 9,9'-bis(4-hydroxyphenyl)fluorene. These can be used individually or in combination as needed. Dihydroxy compounds formed by condensing diols with at least one hydroxyl terminus of the above-mentioned diol components can also be used.

[0021] On the other hand, in 2), examples of compounds having a carboxylic acid or carboxylic acid derivative and a hydroxyl group in one molecule include l-lactide, d-lactide, oxy acids such as hydroxybenzoic acid, their derivatives, oligomers of oxy acids, and compounds in which an oxy acid is condensed on one carboxyl group of a dicarboxylic acid.

[0022] Examples of polyesters include polyethylene terephthalate, polyethylene-2,6-naphthalate, polypropylene terephthalate, polybutylene terephthalate, homopolymers such as polylactic acid, and copolymers thereof. The polyester resin constituting the laminated film in the present invention may be selected from the above homopolymers and copolymers, or homopolymers may be blended together or homopolymers and copolymers may be used.

[0023] Here, as the homopolymer of the polyester resin, it is preferable to use polyethylene terephthalate, polyethylene-2,6-naphthalate, polybutylene terephthalate, or polylactic acid from the viewpoint of film-forming properties, and among these, it is more preferable to use polyethylene terephthalate or polyethylene-2,6-naphthalate because they are easy to process, and from the viewpoint of design, it is particularly preferable to use polyethylene terephthalate.

[0024] Furthermore, a copolymer of polyester resin refers to a polymer in which less than 50 mol% of the total polyester resin consists of either or both different dicarboxylic acid components and diol components. When considering blending with a homopolymer, it is preferable to use a copolymer in which the same molecular structure as the target homopolymer constitutes 50 mol% or more of the total.

[0025] Here, as the copolymer of polyester resin, it is preferable to use one that contains alicyclic dicarboxylic acids, isophthalic acid, or naphthalenedicarboxylic acid as the dicarboxylic acid component, and butanediol, ethylene glycol, spiroglycol, or cyclohexanedimethanol as the diol component, from the viewpoint of excellent polymerization suitability, thermal stability, and compatibility with homopolymers. These may be used individually or in combination as needed.

[0026] In the polyester resin constituting the base film of the laminated film in the present invention, it is preferable that the amount of terephthalic acid residue relative to the dicarboxylic acid component, or the amount of 2,6-naphthalenedicarboxylic acid residue relative to the dicarboxylic acid component, is 70 mol% or more. In particular, in the polyester resin constituting the base film of the laminated film in the present invention, it is preferable to set the amount of isophthalic acid residue relative to the dicarboxylic acid component to 0.5 mol% or more, as this can improve the moldability of the laminated film. Furthermore, it is preferable to set the amount of isophthalic acid residue to 10 mol% or less, as this can suppress a decrease in the transfer efficiency of unevenness due to excessive softening and improve the design. From a similar viewpoint, it is more preferable that the amount of isophthalic acid residue is 1.0 mol% or more and 7.0 mol% or less, and even more preferable that it is 1.5 mol% or more and 3.0 mol% or less.

[0027] Furthermore, in the polyester resin constituting the base film of the laminated film in the present invention, it is preferable that the amount of ethylene glycol residue or 1,4-butanediol residue relative to the diol component is 70 mol% or more, and from the viewpoint that the same effects as described above can be expected, it is preferable that the amount of ethylene glycol residue relative to the diol component is 70 mol% or more, and the amount of cyclohexanedimethanol residue or 1,4-butanediol residue is 0.5 mol% or more and 20 mol% or less, even more preferably 5.0 mol% or more and 17 mol% or less, and particularly preferably 8.0 mol% or more and 15 mol% or less.

[0028] Furthermore, to improve moldability, it is preferable to include a polyalkylene glycol component as a softening agent in the polyester resin. As the polyalkylene glycol component, polyethylene glycol, polypropylene glycol, or polybutylene glycol are preferred, with polyethylene glycol being more preferable due to its high decomposition temperature and the ease of melt-mixing it with the polyester resin.

[0029] It is preferable to have a polyalkylene glycol component content of 0.1% by mass or more per 100% by mass of the base film, as this further enhances moldability. Furthermore, by having a polyalkylene glycol component content of 3.0% by mass or less per 100% by mass of the base film, poor release properties due to thermal decomposition of the polyalkylene glycol component can be suppressed. From a similar viewpoint, it is more preferable that the polyalkylene glycol component content be 0.3% by mass or more and 2.0% by mass or less per 100% by mass of the base film, and even more preferable that it be 0.5% by mass or more and 1.5% by mass or less. From the viewpoint of suppressing film tearing after press processing, it is particularly preferable that the content be 1.2% by mass or less in the base film. The amount of low molecular weight components such as polyalkylene glycol can be measured by the method described later.

[0030] Furthermore, the amount of residues of the copolymer components and the amount of added components were determined by solvent extraction of the laminated film and then proton nuclear magnetic resonance spectroscopy ( １ ¹H-NMR and carbon nuclear magnetic resonance spectroscopy ( １３ Analysis can be performed using known methods such as C-NMR.

[0031] <Film Characteristics> In the laminated film of the present invention, it is preferable that the average center surface roughness SRa, measured from at least one release layer side surface of the laminated film, decreases by 50.0% or more after heating and pressing using the following method compared to the value before heating and pressing. The heating and pressing method will be described later.

[0032] In this embodiment, the surface irregularities on the surface layer of the laminated film provide excellent vacuum adsorption in the pre-press stage due to the surface irregularities applied to the surface layer before pressing. Excellent vacuum adsorption allows, for example, reaching the target vacuum adsorption level in the pressing process in a short time, and suppresses wrinkles during vacuum adsorption. Furthermore, a decrease of 50.0% or more in SRa after heating and pressing compared to before heating and pressing prevents foreign matter from entering the area sandwiched by the press after heating and pressing. From the viewpoint of preventing foreign matter from entering the area sandwiched by the press, it is more preferable that the SRa after heating and pressing decreases by 60.0% or more compared to before heating and pressing, and even more preferable that it decreases by 80.0% or more. To achieve the above embodiment, the bending rigidity of the laminated film must be 400 × 10 －３ N・mm ２ The following is important: The bending rigidity of the laminated film is 400 x 10 －３ N・mm ２ If the temperature exceeds a certain value, it may be difficult to reduce the SRa after heat pressing by more than 50.0% compared to before heat pressing because the film becomes too rigid. Furthermore, while surface irregularities can be created by particle mixing, embossing, sandblasting, coating, and thermal imprinting, it is especially important to create the embossed irregularity within a range of less than 90°C above the highest tanδ peak temperature observed in the laminated film, particularly when using embossing or thermal imprinting. If embossing is performed at a temperature 90°C or higher above the highest tanδ peak temperature observed in the laminated film, the SRa after heat pressing may not decrease by more than 50.0% compared to before heat pressing. This is because a sample heat-processed at a certain temperature A will be less likely to change its shape from the shape formed at the higher temperature when heat is applied at a lower temperature after processing. Also, when surface irregularities are created by particle mixing, the bending rigidity of the laminated film should be 400 × 10 －３ N・mm ２It is important to use particles with a Vickers hardness of 5 or less, as described below. For example, when surface irregularities are imparted by adding particles with a Vickers hardness exceeding 5, which is the case for many inorganic particles, it is rare for the SRa after heating and pressing to decrease by more than 50.0% compared to before heating and pressing. Therefore, in order to reduce the SRa by more than 50.0% compared to before heating and pressing by mixing in particles, it is preferable to impart surface irregularities with particles with a Vickers hardness of 5 or less. Examples of particles with a Vickers hardness of 5 or less include organic particles. Examples of organic particles include organic particles composed of acrylic resins, styrene resins, silicone resins, polyimide resins, etc., and core-shell type organic particles. Among these, styrene resins are preferred from the viewpoint of film formation stability.

[0033] From the viewpoint of vacuum adsorption, the laminated film of the present invention preferably has a center surface average roughness SRA of 0.01 μm or more on at least one surface of the laminated film. On the other hand, from the viewpoint of film formation stability and handling properties, the SRA is preferably 20.0 μm or less. Furthermore, from the viewpoint of vacuum adsorption, the SRA is more preferably greater than 0.20 μm and 20.0 μm or less, even more preferably between 1.7 μm and 10.0 μm, and particularly preferably between 2.6 μm and 8.0 μm. To make the SRA between 0.01 μm and 20.0 μm, methods such as particle kneading, embossing, sandblasting, coating, and thermal imprinting can be used, but various methods can be selected on the premise that the SRA after heating and pressing is reduced by 50.0% or more compared to before heating and pressing. In addition, the release film used in compression molding is heated and pressed with the highly release surface in contact with the fluid molding resin, and the opposite side in contact with the non-fluid mold. At this time, the surface of the film located on the mold resin side affects the fluidity of the mold resin, and if the surface roughness is low, the mold resin may not be sufficiently filled (embedded) to the edge of the wafer, resulting in a resin chipped appearance at the edge. For this reason, it is preferable that the average center surface roughness SRa measured from at least one release layer side surface of the laminated film be 0.01 μm or more and 20.0 μm or less, more preferably 1.7 μm or more and 10.0 μm or less, and even more preferably 2.6 μm or more and 8.0 μm or less.

[0034] In the laminated film of the present invention, it is preferable that the average center surface roughness SRa on at least one release layer side surface of the laminated film is 1.0 μm or more lower after heating and pressing using the method described above than before heating and pressing. In the present invention, a higher SRa is preferable from the viewpoint of vacuum adsorption, but a lower SRa is preferable after heating and pressing to prevent foreign matter from entering the area sandwiched by the press. From the viewpoint of achieving both, it is preferable that the SRa is high before pressing and lower after pressing. From the same viewpoint, it is more preferable that the SRa after heating and pressing is 1.7 μm or more lower than before heating and pressing. In order to reduce the SRa after heating and pressing by 1.0 μm or more compared to before heating and pressing, it is preferable to use a roll die with a mesh size of less than 100 Me (me) to emboss the surface.

[0035] From the viewpoint of suppressing vacuum adsorption in molds and resin chipping, the laminated film of the present invention has a number of protrusions with a height of 0.3 μm to 1.6 μm measured from at least one release layer side surface of the laminated film of 50 protrusions / 80089 μm. ２ More than 5000 pieces / 80089μm ２ The following is preferable. From a similar viewpoint, the number of protrusions is 100 per 80089 μm. ２ More preferably, the above is true. Also, from the same viewpoint as above, the number of protrusions is 4000 per 80089 μm. ２ It is more preferable that the number be less than 2000 particles / 80089 μm ２ It is even more preferable that the following conditions are met: 1000 particles / 80089 μm ２ The following is particularly preferable:

[0036] Furthermore, the number of such protrusions is 100 per 80089 μm. ２ If the above is the case, for example, it can be adjusted by embossing using a roll mold with a grain size of less than 80 Me (me). Also, the number of protrusions can be set to 1000 per 80089 μm.２ In such cases, a preferred control method is to knead particles of 0.1 to 10 μm size into the laminated film at a ratio of 5 to 28% by mass.

[0037] The laminated film of the present invention, from the viewpoint of suppressing vacuum adsorption in molds and other devices and resin chipping during compression molding, has a number of protrusions SPc of 20 / mm² with a protrusion height of 0.4 μm or more and less than 2.0 μm, measured from at least one release layer surface of the laminated film. ２ More than 100 pieces / mm ２ The following is preferable. Here, SPc represents the number of peaks per unit area. While a larger SPc allows for easier air release, excessive air release can prolong the time required to reach the target vacuum level. Furthermore, within the range of 1.7 μm to 10.0 μm for the average center surface roughness SRa, an SPc of 20 peaks / mm is preferable. ２ More than 100 pieces / mm ２ The following is particularly preferable because it allows for good material release during pressing, good vacuum adsorption, and suppresses resin chipping during compression molding. For this reason, an SPc of 20 pieces / mm ２ More than 100 pieces / mm ２ The following is preferable. To bring SPc within this range, it is preferable to impart surface irregularities by embossing with a roll mold with a grain size of less than 100 mesh. If particles are mixed in or embossed with a mold with a grain size exceeding 100 mesh, the SPc will be 20 particles / mm ２ More than 100 pieces / mm ２ It may not be as follows:

[0038] In the present invention, it is preferable that the base film is a laminate of two or more layers having at least a main layer A and a sub-layer B. Here, the main layer A is a layer that accounts for 60% or more of the total film thickness and is responsible for flexibility. The sub-layer B is a layer that accounts for 40% or less of the total film thickness and is harder than the main layer and is responsible for film formation stability. As long as the above configuration is met, it may be a three-layer laminate configuration of sub-layer B / main layer A / sub-layer B, where the main layer A is laminated on both sides of the sub-layer B, or it may be a configuration in which three to 10,000 layers are laminated alternately. Furthermore, it is preferable that a layer A is also formed on the back side opposite to the release layer side (e.g., a release layer / layer A / layer B / layer A configuration), as this allows for good air release when the laminated film and mold are adsorbed and fixed by vacuum, thereby suppressing wrinkle formation. Furthermore, if there are two or more main layers A, it is preferable that at least one of them satisfies this embodiment, and it is more preferable that any of the multiple layers A satisfy this embodiment.

[0039] The stacking ratio of main layer A to sub-layer B is not limited, but if film formation stability is prioritized, it is preferable to increase the ratio of sub-layer B, and if flexibility is prioritized, it is preferable to increase the ratio of main layer A. For example, the stacking ratio in the thickness direction can be sub-layer B:main layer A = 1:1 to 1:40, and considering film formation stability and flexibility, it is preferable to have a ratio of 1:5 to 1:20. The absolute thickness of main layer A is preferably 1 μm or more from the viewpoint of lowering SRa by heat pressing, and is preferably less than 40 μm from the viewpoint of film formation stability.

[0040] In the present invention, the thickness of the laminated film is preferably 20 μm to 100 μm from the viewpoint of suppressing film tearing during press processing and vacuum adsorption. More preferably, it is 23 μm to 75 μm.

[0041] In the laminated film of the present invention, if the base film has a laminated structure including at least a main layer A and a sub-layer B, it is preferable that the plane orientation coefficient of the sub-layer B is 0.15 or more and 0.17 or less. In the present invention, from the viewpoint of reducing the SRa by 50.0% or more compared to before heat pressing, it is preferable that the bending rigidity of the film be as low as possible. On the other hand, if the entire base film is composed of layers with low rigidity, it is preferable from the viewpoint of lowering the SRa by heat pressing, but because the rigidity is too low, the stability of film formation is low, resulting in poor productivity, or even if production is possible, defects such as film tearing may occur during subsequent secondary processing. For this reason, it is preferable to set the plane orientation coefficient of the sub-layer B to 0.15 or more and 0.17 or less so that even if the rigidity of the film as a whole is low, the decrease in productivity and film tearing can be suppressed by the sub-layer B with a high plane orientation coefficient. In order to set the plane orientation coefficient of the sub-layer B to 0.15 or more and 0.17 or less, it is preferable to produce a laminated film that includes a step of stretching the constituent resin of the sub-layer B with an area magnification of 10 times, and containing 80% by mass or more of homopolyester.

[0042] In the laminated film of the present invention, two peaks are present in the tanδ-temperature curve obtained from dynamic viscoelasticity measurement under the following measurement conditions. When the low-temperature peak is called Peak A and the high-temperature peak is called Peak B, it is preferable that the peak top temperature of Peak A is less than 100°C and the peak top temperature of Peak B is 100°C or higher. (Dynamic viscoelasticity measurement conditions) Heating temperature: 20°C to 200°C Heating rate: 3°C / min Sampling frequency: 1 second Measurement frequency: 1 Hz In the present invention, SRa is reduced by heating and pressing at 125°C, and in order to efficiently reduce SRa by heating and pressing, it is preferable to have a layer with a low tanδ peak temperature. On the other hand, if the laminated film is composed only of layers with a low tanδ peak temperature of less than 100°C, the rigidity is too low, resulting in low film formation stability, poor productivity, or even if production is possible, problems such as film tearing may occur during subsequent secondary processing. Furthermore, it may have poor heat resistance and insufficient release properties due to heating and pressing. Therefore, it is preferable to have a layer with a tanδ peak temperature of 100°C or higher, in addition to a layer with a tanδ peak temperature of less than 100°C, in order to provide heat resistance and mechanical strength.

[0043] The laminated film of the present invention has a bending rigidity of 10 × 10 －３ N・mm ２ The above 150 x 10 －３ N・mm ２ The following is preferable. Having a bending rigidity within this range allows, for example, when used as the lower release film shown in Figure 2 in a molding method using guide pins in the semiconductor molding process, it suppresses film bulging caused by the guide pins during semiconductor molding and suppresses the defect of thinning the resin at the mold edge. The degree of film bulging can be expressed as the tent diameter shown in Figure 3. A smaller tent diameter is preferable. The tent diameter is preferably 50 mm or less. The tent diameter can be measured by the method described in the examples. From the viewpoint of suppressing film bulging, the tent diameter is preferably 30 mm or less, and particularly preferably 15 mm or less. Furthermore, this embodiment provides excellent processability for drilling holes with lasers or needles for the purpose of adsorption to suction holes. Bending rigidity of 10 × 10 －３ N・mm ２ If the bending rigidity is less than 150 x 10, the film's rigidity is too low, which can cause the film to tear during molding or wrinkles to form in the film during molding, and these wrinkles may be transferred to the molding resin, impairing the appearance. On the other hand, if the bending rigidity is 150 x 10 －３ N・mm ２ If it exceeds this, the resin at the mold edge may become thinner due to film bulging, and the processability for drilling holes may be poor. From the viewpoint of reducing the tent diameter due to film bulging, suppressing wrinkles, and improving the processability for drilling holes, 10 x 10 is preferable. －３ N・mm ２ The above 100 x 10 －３ N・mm ２ More preferably 12 × 10 －３ N・mm ２ 80 x 10 －３ N・mm ２The following are possible methods for controlling the bending stiffness within this range: For example, the base film may be a biaxially oriented film, and the constituent polyester resin may contain 0.5 mol% to 20 mol% of isophthalic acid residue relative to the dicarboxylic acid component; the polyester resin may contain 0.5 mol% to 20 mol% of cyclohexanedimethanol residue, 1,4-butanediol residue, or 1,3-propanediol residue as part of the diol component; and the polyalkylene glycol component may be 0.1% by mass or more per 100% by mass of the base film. These methods can also be used in combination.

[0044] The laminated film of the present invention preferably has a puncture strength of 2N or more and 5N or less, as measured by the method described in JIS Z1707 (1997). Controlling it within this range provides excellent drilling performance in laser and needle processing. Puncture strength is not uniformly determined by Young's modulus alone; for example, so-called nylon film, which is a polyamide resin, has a high puncture strength despite having a lower Young's modulus than polyester film. The composition of the resin, viscosity characteristics, orientation characteristics, and crystallization state all have an influence, and a specific Young's modulus does not necessarily result in a specific puncture strength. In the present invention, to achieve a puncture strength of 2N or more and 5N or less while maintaining bending rigidity within the scope of the present invention, it is preferable to use a resin in which the thickness of the base film is 35 μm or less, the main component is polyester resin, and the resin contains cyclohexanedimethanol residues, 1,4-butanediol residues, or 1,3-propanediol residues in an amount of 10 mol% or more and 20 mol% or less of the diol component, and the polyalkylene glycol component content is 0.1% by mass or more per 100% by mass of the base film, and then heat-treat the resin constituting the base film at a temperature range of Tm -15°C or higher and Tm -5°C or lower after biaxial stretching.

[0045] The laminated film of the present invention preferably has a Young's modulus of 1.5 GPa or more and 3.0 GPa or less in both the longitudinal and width directions. By keeping it within this range, the puncture resistance is maintained within a desirable range while having appropriate rigidity, thereby suppressing the occurrence of wrinkles in the film during molding. This suppresses deterioration of the design due to wrinkle transfer to the mold resin caused by wrinkles. A Young's modulus of 2.0 GPa or more and 3.0 GPa or less in both the longitudinal and width directions is more preferable because it suppresses wrinkles more significantly. However, if it exceeds 3.0 GPa, the rigidity is too high, which can lead to a tenting phenomenon caused by film bulging, resulting in poor resin backing, or poor vacuum adsorption, making compression molding impossible.

[0046] <Method for Manufacturing the Base Film> In the present invention, the base film of the laminated film is preferably a biaxially oriented film from the viewpoint of productivity and thickness uniformity. Here, a biaxially oriented film can be obtained by stretching an unstretched film obtained by any conventionally known method, either by stretching it in the longitudinal direction and then in the width direction, or by a sequential biaxial stretching method in which the film is stretched in the width direction and then in the longitudinal direction, or by a simultaneous biaxial stretching method in which the longitudinal and width directions of the film are stretched almost simultaneously. Furthermore, the state of biaxial orientation achieved by biaxial stretching shall be determined by the method for determining the biaxial orientation state by laser Raman spectroscopy described later.

[0047] In this stretching method, the stretching ratio is preferably 2.7 times or more and 3.6 times or less in the longitudinal direction, and more preferably 3.0 times or more and 3.4 times or less. Furthermore, the stretching temperature in the longitudinal direction is preferably 70°C or more and 90°C or less. Furthermore, the stretching ratio in the width direction is preferably 3.0 times or more and 5.0 times or less, and more preferably 3.2 times or more and 4.0 times or less. In this invention, the machine flow direction (MD direction) is the longitudinal direction, and the direction perpendicular to the longitudinal direction is the width direction (TD direction). However, if the longitudinal and width directions of the film are unknown, the breaking strength is measured in any one direction of the film (0°) and in directions of 15°, 30°, 45°, 60°, 75°, 90°, 105°, 120°, 135°, 150°, and 165° from that direction. The direction with the highest breaking strength is considered the width direction, and the direction perpendicular to the width direction is considered the longitudinal direction.

[0048] Furthermore, the film is heat-treated after biaxial stretching. The heat treatment can be carried out by any conventionally known method, such as in an oven. Preferably, this heat treatment is carried out in an atmosphere with a temperature of Tm -40°C or higher and Tm -5°C or lower than the film's crystal melting peak temperature (Tm). Setting the heat treatment temperature to Tm -40°C or higher allows for sufficient relaxation of the stretch stress, improving moldability during press working. Also, setting the heat treatment temperature to Tm -5°C or lower suppresses excessive orientation relaxation of the film, thereby suppressing film tearing during press working. From a similar viewpoint, the heat treatment temperature is more preferably Tm -30°C or higher and Tm -8°C or lower, and even more preferably Tm -20°C or higher and Tm -10°C or lower.

[0049] The heat treatment time can be set arbitrarily within a range that does not degrade the properties, but it is preferable to set it to 5 seconds or more and 60 seconds or less, as this enhances the effect of the heat treatment temperature as described above. From the same viewpoint, a heat treatment time of 7 seconds or more and 40 seconds or less is more preferable, and 10 seconds or more and 25 seconds or less is even more preferable.

[0050] <Composition and Structure of the Release Layer> The release layer in the present invention is preferable because it contains a binder resin, which improves adhesion to the base film and allows adjustment of the peeling force with respect to the object to be peeled off. Specific examples of binder resins include polyester resin, polystyrene resin, acrylic resin, urethane resin, polyvinyl, polyalkylene glycol, polyalkyleneimine, cellulose, starches, etc., but acrylic resin is preferably used from the viewpoint of improving moldability and release properties.

[0051] Examples of the above-mentioned acrylic resins include homopolymers or copolymers of alkyl (meth)acrylate esters, and (meth)acrylate ester copolymers having curable functional groups in the side chains and / or at the ends of the main chain. Examples of curable functional groups include hydroxyl groups, carboxyl groups, epoxy groups, and amino groups. Among these, acrylic monomer copolymers obtained by copolymerizing an acrylic monomer with an acrylic ester having curable functional groups in the side chains and / or at the ends of the main chain are preferred.

[0052] Furthermore, it is preferable to add a crosslinking agent as a component of the release layer. By using various crosslinking agents in combination with the aforementioned resin, the heat resistance can be dramatically improved. The crosslinking agent is preferably one or more selected from oxazoline resin, melamine resin, epoxy resin, carbodiimide resin, and isocyanate resin. From the viewpoint of the release layer's resistance to solvents, melamine resin is even more preferably used. The crosslinking agent can be mixed and used in any ratio, but in terms of improving release properties, it is preferable to add 5 parts by mass or more and 50 parts by mass of the crosslinking agent per 100 parts by mass of the binder resin, and more preferably 10 parts by mass or more and 40 parts by mass. If the amount of crosslinking agent added is less than 5 parts by mass, the release effect may be insufficient, or scratches may occur during roll transport. Also, if it exceeds 50 parts by mass, unevenness is likely to occur during application, resulting in a decrease in release properties, which is undesirable.

[0053] In the present invention, it is preferable that the resin composition forming the release layer contains an additive suitable for imparting release properties, in addition to the binder resin and crosslinking agent. The additive is preferably in an amount of 3 parts by mass or more and 50 parts by mass or less, when the sum of the masses of the binder resin and the crosslinking agent is 100 parts by mass. By adding 3 parts by mass or more of the additive, release properties can be imparted, and by adding 50 parts by mass or less, it is possible to impart heat resistance to the release layer that can withstand compression molding, thereby suppressing a decrease in release properties. Preferably, it is 10 parts by mass or more and 42 parts by mass or less, and especially preferably 20 parts by mass or more and 34 parts by mass or less.

[0054] In this invention, the term "additive" refers to a compound that, when added to a resin, has mold-release properties on the surface of the resin. Specifically, examples include silicone-containing compounds, fluorine compounds, waxes such as paraffin wax, polyethylene wax, and carnauba wax, long-chain alkyl group-containing compounds, and resins. Among these, long-chain alkyl group-containing compounds are preferred from the viewpoint of suppressing mold release and surface defects. In this invention, the term "long-chain alkyl compound" refers to a compound having a long-chain alkyl group, and is not particularly limited as long as it contains a long-chain alkyl group, but examples include those having a long-chain alkyl group in the side chain of the main chain polymer.

[0055] In compounds having a long-chain alkyl group in the side chain of the main chain polymer, examples of main chain polymers include acrylate-based polymers or copolymers, polyvinyl alcohol (including partially saponified polyvinyl acetate), ethylene-vinyl alcohol copolymer (including partially saponified ethylene-vinyl acetate copolymer), vinyl alcohol-acrylic acid copolymer (including partially saponified vinyl acetate-acrylic acid copolymer), polyethylimine, polyvinylamine, styrene-maleic anhydride copolymer, and polyurethane.

[0056] <Method for forming a release layer> A preferred embodiment of the laminated film in the present invention is characterized in that a release layer is provided on one or both sides of the base film.

[0057] When a release layer is provided on only one side of the base film, it is preferable because it shortens the manufacturing process of the release layer. Furthermore, when a release layer is provided on both sides of the base film, it is preferable because it also provides release properties to the mold side, suppressing the adhesion of precipitated oligomers and other materials to the mold.

[0058] Methods for providing a release layer on a base film include: dissolving or dispersing the resin composition of the release layer in a solvent, applying it to the base film, drying the solvent after application, and then heating it; melt co-extruding the resin composition of the release layer together with the base film to form a sheet together with the base film using the method described above; extruding the molten resin composition of the release layer onto a base film that has undergone processing such as corona treatment to provide a resin layer; and laminating a base film and a release layer that are manufactured separately. Among these, the method of applying the release layer is preferred from the viewpoint of being able to freely select the preferred binder resin, additives, and crosslinking agents.

[0059] A preferred method for applying the release layer to the base film layer is to apply it uniformly using a metering bar or gravure roll, followed by drying in an oven. When applying using a coating method such as gravure coating, it is preferable to apply the layer in a way that does not hinder the flow and flattening (leveling) of the coated layer. The oven temperature is preferably 70 to 245°C, more preferably 80 to 235°C, and especially preferably 90 to 225°C. If the drying temperature is lower than 70°C, the release layer may not harden sufficiently, and the base film and the release layer may not adhere properly. Also, if the temperature is higher than 245°C, the accuracy of the coating thickness may decrease due to thermal deformation of the film. The heat treatment time is preferably 1 to 60 seconds, more preferably 5 to 40 seconds, and especially preferably 10 to 30 seconds.

[0060] In the laminated film of the present invention, a release layer can be provided by in-line coating in order to ensure stable release properties. Specifically, in the manufacturing process of the base film, it is preferable to uniformly apply a solution or dispersion of the resin composition of the release layer onto a film that has been at least uniaxially stretched using a metering ring bar or gravure roll, and then dry the coating while stretching the film. By performing the above method, the thickness of the release layer can be made more uniform. Furthermore, by increasing the molecular affinity with the base film, the adhesion between the base film and the release layer can be improved, and the degree of hardening of the coating film is increased by heat treatment at a higher temperature compared to off-line coating, improving heat resistance and chemical resistance, while at the same time eliminating or shortening the aging treatment after manufacturing.

[0061] In the present invention, the laminated film is preferable because the release layer thickness after drying is 10 nm or more, which allows the release layer to maintain conformity to the surface shape of the base film even when subjected to high pressure such as in a compression mold. Furthermore, a release layer thickness of 2000 nm or less after drying is preferable because it enhances the design without impairing the uneven shape of the base film. From a similar viewpoint, the release layer thickness after drying is more preferably 50 nm or more and 1500 nm or less, and even more preferably 100 nm or more and 1200 nm or less.

[0062] Similarly, if particles are present in the release layer, it can lead to reduced release properties due to uneven surface irregularities and process contamination due to particle detachment. It is preferable that the particle content in the release layer be 4% by mass or less per 100% by mass of the layer, as this allows for both release properties and moldability without hindering the effects of the surface shape of the base film. A particle content of 1% by mass or less is more preferable, and it is even more preferable that no particles are present.

[0063] In the present invention, the release surface of the laminated film is preferable if the water contact angle is 85° or more, as this improves release properties. Furthermore, a water contact angle of 120° or less is preferable because it improves the conformability of the mold resin and enhances the design. From a similar viewpoint, a water contact angle of 90° or more and 115° or less is more preferable, and 95° or more and 110° or less is even more preferable.

[0064] <Method for Manufacturing Semiconductors> A method for manufacturing semiconductors using the laminated film of the present invention involves stacking the laminated film and a silicon wafer on which semiconductor chips are placed in order in a molding apparatus, placing a measured amount of molding resin on the wafer, then transporting the laminated film of the present invention from the top so that the release layer side is on the molding resin side, vacuum adsorption, and compression pressing while heating the mold. In this invention, the temperature of the molding resin used in the process of covering with the molding resin is 25°C and the shear rate is 2.5 s. －１ A viscosity of 70 Pa·s or more and 1000 Pa·s or less is preferable because it facilitates filling to the wafer edge and reduces curling after processing. That is, one preferred embodiment of the semiconductor manufacturing method in the present invention is a semiconductor manufacturing method that includes a step of performing compression molding by placing the laminated film in a mold inside a compression apparatus so that the release layer of the laminated film and the mold resin are in contact. Furthermore, in the full molding method in which the mold resin is filled to the outside of the wafer, as shown in Figure 2, the mold resin may come into contact with the bottom surface of the mold, so a release film is also placed on the underside of the substrate to prevent contamination of the lower mold by the mold resin. That is, one preferred embodiment of the semiconductor manufacturing method in the present invention is a semiconductor manufacturing method that includes a step of performing compression molding by placing the laminated film in a mold inside a compression apparatus (underside of the substrate) so that the release layer of the laminated film and the substrate are in contact.

[0065] As described above, the laminated film of the present invention has release properties during compression molding and its surface irregularities are reduced after pressing. Therefore, when used on the underside of the substrate during full molding, it is possible to prevent the molding resin from penetrating the underside of the wafer, which becomes the press area, after heating and pressing. Due to these effects, the laminated film of the present invention is suitable as a release film for, for example, circuit manufacturing processes and semiconductor manufacturing processes, and is particularly suitable as a release film for semiconductor compression molding, and even more so as a release film for the underside of a semiconductor compression molded substrate.

[0066] <Semiconductor> The semiconductor of the present invention is characterized by the fact that a large-scale circuit integrated on a single chip is deliberately fragmented into multiple small chips, mounted on a substrate called an interposer that connects the chiplets, and then enlarged and housed in a single package. By using chiplets, a large-scale circuit combining chiplets from different process nodes (generations of microfabrication technology) and different process technologies (logic, memory, application processors, analog ICs, RF circuits, power semiconductors, etc.) can be housed in a single semiconductor. In other words, the semiconductor of the present invention consists of multiple semiconductor elements connected by an interposer. Furthermore, as described above, because the semiconductor of the present invention consists of multiple semiconductor elements connected by an interposer, the area is 100 mm². ２ More than 250000mm ２ The following is preferable. For similar reasons, the semiconductor of the present invention preferably has a mold resin thickness of 0.1 mm or more and 3.0 mm or less. The semiconductor of the present invention preferably has an in-plane thickness uniformity standard deviation of 0.05 μm or more and 1.0 μm or less.

[0067] In the semiconductor of the present invention, it is preferable that a spectrum originating from dimethylsiloxane ions is detected when the mold resin is measured by the following measurement method. As described above, the semiconductor is obtained by placing a measured amount of mold resin on a silicon wafer on which a semiconductor chip is arranged, and then compressing and pressing it while heating the mold from above. After the curing of the mold resin is completed in this process, the release film is peeled off to create a semiconductor packaged at the wafer level. State-of-the-art semiconductors have thin wafers to reduce thickness and weight, and the problem of the wafer warping toward the mold resin due to the curing shrinkage of the mold resin has become apparent. Dimethylsiloxane has a low coefficient of thermal expansion, and due to the stress relaxation properties of the resin, it can reduce wafer warping caused by the curing of the mold resin. For this reason, it is preferable that a spectrum originating from dimethylsiloxane ions is detected in the semiconductor of the present invention. (Method for measuring mold resin) Apparatus: TOF.SIMS 5 (manufactured by IONTOF) Primary ion: Bi ３＋＋ Secondary ion polarity: Negative only Etching ion: Ar Gas cluster ion beam (Ar-GCIB) The semiconductor of the present invention is preferably obtained by a manufacturing method using the laminated film of the present invention from the viewpoint of yield due to resin chipping and resin backing.

[0068] [Methods for measuring and evaluating properties] (1) Dissolve the polyester composition film in hexafluoroisopropanol (HFIP), １ H-NMR and １３ The content of each monomer residue component is quantified using 1C-NMR. In the case of laminated films, the components constituting each layer are collected and evaluated by scraping off each layer of the film according to the laminate thickness.

[0069] (2) Cross-sectional observation of laminated film The laminated film is embedded in epoxy resin, and two cross-sections, one in an arbitrary direction and the other perpendicular to it, are cut perpendicular to the thickness direction using a known method suitable for the type of particles (microtome method or ion milling method). Then the cross-sections are observed using either a transmission electron microscope (TEM H7100 manufactured by Hitachi, Ltd.) or a scanning electron microscope (SEM JSM-6700F manufactured by JEOL Ltd.).

[0070] (2-1) Laminate film thickness, base film thickness, release layer thickness Using the above method, select a magnification that allows observation of the laminate film thickness, base film thickness, and release layer thickness, and acquire images of three different locations in two directions, and calculate the average value of the total of six points.

[0071] (3) The layer thickness distribution of the layered film is determined by observing the sample, which has been thinned using an ultramicrotome, with a transmission electron microscope (TEM). Specifically, a JEM-1400 Plus transmission electron microscope (manufactured by JEOL Ltd.) is used to observe the cross-section of the laminated film under conditions of an acceleration voltage of 100 kV, and the layer structure (number of layers, regular arrangement, layer thickness distribution) and the thickness of each layer are measured by obtaining a cross-sectional image. In order to obtain a large difference in brightness between each layer, an electron staining agent (RuO ４ A staining technique using ) is employed. In addition, depending on the thickness of each layer, observation is performed at a direct magnification of 40,000x if the thin film layer thickness is less than 100 nm, at a direct magnification of 20,000x if the thin film layer thickness is between 100 nm and 500 nm, and at 1,000x to 10,000x depending on the thickness if it is 500 nm or more, and the layer thickness distribution is analyzed. Based on the brightness difference of the obtained images, the number of layers, the regular arrangement, the thickness of each layer, the distribution of layer thicknesses, and the layering ratio based on the layer thicknesses are determined.

[0072] (4) Using a sodium D line (wavelength 589 nm) as the light source and methylene iodide as the mounting solution, the refractive index (nMD, nTD, nZD, respectively) in the longitudinal, widthwise, and thicknesswise directions of the film (NAR-4T, manufactured by Atago Co., Ltd.) is measured at 25°C in accordance with JIS K7142 (2014) Method A. A test piece with a refractive index of 1.74 is used. The surface orientation coefficient fn of the film is calculated from the obtained refractive index using the following formula.

[0073] fn=(nMD+nTD) / 2-nZD (formula).

[0074] (5) Number of protrusions with a height of 0.3 μm or more and 1.6 μm or less A scanning white light interference microscope is used to measure 10 fields of view at different locations. The sample set is prepared so that the direction perpendicular to the X-axis direction of the sample stage (Y-axis direction) is the longitudinal direction of the sample film, and measurements are taken under the following measurement conditions. After the following image processing is performed on all obtained images using the accompanying analysis software (VS-Viewer), particle analysis is performed on all fields of view under the following conditions to determine the number of protrusions with a height of 0.3 μm or more and 1.6 μm or less from the reference plane (height zero), and the average value is taken as the number of protrusions with a height of 0.3 μm or more and 1.6 μm or less. <Equipment>: Hitachi High-Tech Science VS-1540 <Measurement Conditions> Objective Lens: 20x Wavelength Filter: 530 white Measurement Device: Piezo Measurement Mode: Wave Measurement Field Size: 283 μm × 283 μm <Image Processing Conditions> Interpolation: Full interpolation Filter: Median 3 × 3 Planar Correction: 4th order <Particle Analysis> Analysis: Protrusion analysis Image Correction: None Height Threshold: 1 μm Reference Height: Zero plane. (Reference plane: Reference height = Zero plane) As the "zero plane" in the above reference height setting, the plane of the "average height (Ave)" that is automatically determined from the following formula (1) in the measurement image (113 μm × 113 μm) obtained by observing a microscope image using the method described above and applying the image processing described above is used as the reference plane (height zero plane).

[0075]

[0076] lx: The length of the X-direction range in each measurement image that has undergone the aforementioned image processing. ly: The length of the Y-direction range in each measurement image that has undergone the aforementioned image processing. h(x,y): The height at each image point (x,y) within the measurement image that has undergone the aforementioned image processing.

[0077] (6) Cut a rectangular piece of Young's modulus film at an arbitrary position along the longitudinal direction (MD) to obtain a sample of 150 mm in length and 10 mm in width. Using a tensile testing machine (Orientec "Tensilon" (registered trademark) UCT-100), perform a tensile test along the longitudinal direction of the film according to the method specified in JIS Z1702 (1994), with an initial tensile chuck distance of 50 mm and a tensile speed of 300 mm / min. Sampling is performed at five points at arbitrary positions, and the average value obtained from the measurements of each sample is adopted. Similarly, the Young's modulus in the width direction (TD) is also determined. Here, in this invention, the machine flow direction (MD direction) is defined as the longitudinal direction, and the direction perpendicular to the longitudinal direction is defined as the width direction (TD direction). However, if the longitudinal and width directions of the film are unknown, the breaking strength is measured in any one direction of the film (0°) and in directions of 15°, 30°, 45°, 60°, 75°, 90°, 105°, 120°, 135°, 150°, and 165° from that direction. The direction with the highest breaking strength is considered the width direction (TD direction), and the direction perpendicular to the width direction is considered the longitudinal direction (MD direction).

[0078] (7) Bending stiffness (6) Young's modulus evaluation The Young's modulus obtained in the evaluation is E (N / mm ２ ), let b (mm) be the measurement width of the sample size at that time, and h (mm) be the thickness of the measurement sample obtained by method (2-1), and the value obtained from the following calculation formula (i) shall be defined as the film stiffness.

[0079] Film rigidity N・mm ２ 10 －３ = (E × b × h) ３ ) / 12...(i) (8) Water contact angle After leaving the laminated film in an atmosphere of room temperature 23°C and relative humidity 65% ​​for 24 hours, the contact angle of pure water with respect to the measurement surface held horizontally in the same atmosphere is measured at 5 points using a contact angle meter DM-501 (manufactured by Kyowa Interface Science Co., Ltd.), and the average of these measured values ​​is taken as the water contact angle.

[0080] (8-2) Crystal melting peak temperature Tm of the resin constituting the film A 5 mg sample is weighed using an electronic balance and placed in an aluminum sample pan. Measurement is performed using a Rigaku Thermo plus ECO2 series DSC vesta, heating from 25°C to 300°C at a rate of 20°C / min, in accordance with JIS K7121 (1987) and JIS K7122 (1987). Data analysis is performed using the Rigaku Thermo plus ECO2 system. The crystal melting peak temperature and crystal melting enthalpy of each peak are determined from the obtained DSC data. If multiple crystal melting peaks are observed, they are named Tm1, Tm2, ​​... in order from the lowest peak temperature.

[0081] (9) Cut the tanδ peak temperature sample into two sections: 10 mm wide x 20 mm long (for measurement in the long direction) and 10 mm long x 20 mm wide (for measurement in the width direction). For each section, measure tanδ using a Seiko Instruments Inc. "DMS6100" under the following measurement conditions: <Measurement conditions> Heating temperature: 20°C to 200°C Heating rate: 3°C / min Hold time: 5 minutes Sampling: 1 second Measurement frequency: 1 Hz Then, determine the tanδ peak temperature from the values ​​of tanδ (tanD) and temperature (Temp).

[0082] (10) Puncture strength In accordance with JIS Z1707 (1997), the laminated film is stretched tautly over a 20 mm diameter ring, and a stainless steel needle with a diameter of 1 mm and a tip radius of 0.5 mm is used to puncture the center of the ring at a speed of 50 mm / min. The load (N) at which the needle penetrates is defined as the puncture strength.

[0083] (11) Using a high-precision micro-shape measuring instrument (3D surface roughness meter) of the SPc stylus method, the surface morphology of the polyester film is measured in three dimensions in accordance with JIS B0601 (1994) and under the following conditions.・Measurement device: 3D micro-shape measuring instrument (model ET-4000A) manufactured by Kosaka Research Institute Co., Ltd. ・Analysis equipment: 3D surface roughness analysis system (model TDA-31) ・Stylus: Tip radius 0.5 μmR, diameter 2 μm, made of diamond ・Stylus pressure: 100 μN ・Measurement direction: Average after measuring once in the longitudinal direction of the film and in the width direction of the film ・X measurement length: 1.0 mm ・X feed speed: 0.1 mm / s (measurement speed) ・Y feed pitch: 5 μm (measurement interval) ・Y number of lines: 81 (number of measurements) ・Z magnification: 20 times (vertical magnification) ・Low frequency cutoff: 0.20 mm (undulation cutoff value) ・High frequency cutoff: R + W mm (roughness cutoff value) R + W means no cutoff. • Filter type: Gaussian space type • Leveling: Yes (slope correction) • Reference area: 1 mm ２ SPc(400-2000nm) indicates the number of protrusions between 400nm and 2000nm per reference area, and is calculated using formula (b) after analysis with the following settings in the analysis system. ・Slice level conditions: Fixed vertical spacing, center pitch level 0.05μm ・Vertical level spacing 0.025μm SPc400: SPc value with a lower limit of 375nm, center level 400nm, and upper limit of 425nm SPc2000: SPc value with a lower limit of 1975nm, center level 2000nm, and upper limit of 2025nm Formula (b) SPc(400-2000nm) = SPc400 - SPc2000.

[0084] (12) Center surface average roughness SRa The surface morphology of the release film is measured using a 3D micro-shape measuring instrument (model ET-4000A, manufactured by Kosaka Research Institute Co., Ltd.) under the following measurement conditions. (Measurement conditions) ・Measurement device: 3D micro-shape measuring instrument (model ET-4000A), manufactured by Kosaka Research Institute Co., Ltd. ・Stylus: Model ET-1480 (tip radius 0.5 μmR, diameter 2 μm, made of diamond) ・Stylus pressure: 100 μN ・Measurement direction: Film width direction ・X-axis (film width direction) measurement length: 1.0 mm ・Y-axis (film longitudinal direction) measurement length: 0.40 mm ・Measurement speed: 0.1 mm / sec ・X-axis feed pitch: 1 μm (measurement interval) ・Y-axis feed pitch: 5 μm (measurement interval) ・Y-axis line count: 81 lines (number of measurements) ・Z-axis measurement magnification: 10,000 times (vertical magnification) ・Retraction amount: 2 mm Next, the obtained measurement data is imported into a 3D surface roughness analysis system (model TDA-31), and the mean center surface roughness SRa, a 3D parameter extended to three dimensions according to JIS-B0601 (1994) as defined in the manual accompanying the measuring instrument and analysis system, is calculated under the following analysis conditions. The above measurement is performed by taking a measurement with an arbitrary direction as the X-axis and another measurement with a direction perpendicular to that direction as the X-axis, and the average of the two measurements is adopted.

[0085] (Analysis conditions) ・Analysis equipment: 3D surface roughness analysis system (model TDA-31) ・Filter method: Gaussian space type ・Leveling: Yes, full range (slope correction) ・Low frequency cutoff: 0.250 mm ・Low frequency buffer length: λc × 0.5 ・Recommended low frequency cutoff range: 1 / 5 of wavelength ・High frequency cutoff: 0 mm ・High frequency buffer length: None.

[0086] (13) Using a press machine with both the upper and lower die temperatures heated to 125°C, a three-layer structure consisting of "SUS304 plate with a thickness of 0.5 mm and an arithmetic mean roughness Ra of 0.1 μm" / laminated film / "SUS304 plate with a thickness of 0.5 mm and an arithmetic mean roughness Ra of 0.1 μm" is placed between the upper and lower dies. The SUS304 plate used is hairline finished and has a maximum height Rz (JIS B0601-2001) of 2 μm or less. With a preheating time of 5 minutes, the press is heated and pressed for 10 minutes under conditions of 4.0 MPa. The SRa of the laminated film after the press is measured using the method described in (12) Center surface average roughness SRa.

[0087] (14) Moldability The evaluation is performed using a 150 mm square, 5 mm deep concave mold and a vacuum forming machine (Seiko Sangyo Co., Ltd.: machine name "300X"). After preheating a laminated film cut to A4 size with an infrared heater, it is vacuum-suctioned into a mold heated to 175°C and made to conform to the mold. After releasing the vacuum, the depth at the corners of the removed laminated film is measured, and the average value for the four corners is taken as the molded depth. The conformability to the mold is evaluated as follows based on the average value of the obtained molded depth and the reproducibility of the mold shape. A: The average value of the molded depth is 4.8 mm or more, and the corners on the bottom surface of the mold at the center of the mold recess are sharply formed. B: The average value of the molded depth is 4.5 mm or more, and the corners on the bottom surface of the mold are rounded, but are formed. C: The average value of the molded depth is less than 4.5 mm.

[0088] A grade of B or higher is considered a passing grade.

[0089] (15) Using a release vacuum press, a 2 mm thick mold resin (Nagase ChemteX Co., Ltd.: product name "R4212") is applied to the release layer surface of the laminated film under vacuum and pressure of 2 MPa while being held at 125°C for 10 minutes. After that, the laminated film is left in an atmosphere at room temperature of 23°C and relative humidity of 65% for 24 hours, and then a peel test is performed on the laminated film at a peel angle of 90° and a peel speed of 300 mm / min. The peel force between the epoxy resin and the film is measured in N=3 units, the average value is calculated and evaluated according to the following criteria: A: Less than 3.0 N / 25 mm B: 3.0 N / 25 mm or more A is considered a pass. If natural peeling occurs, it will also be considered A. If film tearing occurs during peeling and it is difficult to measure the peel strength, an additional sample may be prepared and the measurement performed again up to once, and if it is still difficult to measure, it will be judged as B.

[0090] (16) Vacuum adsorption during compression molding Using a compression molding apparatus (Apic Yamada Co., Ltd.: apparatus name "WCM-300"), mold resin (Nagase ChemteX Co., Ltd.: product name "R4507"), measured with a dispenser, is dropped onto a 12-inch silicon dummy wafer to a thickness of 1.5 mm to cover the dummy chip, and placed on the lower mold of the molding die. The mold temperature is set to 115°C, and the laminated film is placed on the concave upper mold so that the release surface is in contact with the mold resin, and then vacuum is applied to prevent wrinkles. At this time, the vacuum adsorption performance is determined from the achieved vacuum level as follows: A: The vacuum level increased without any problems, and the process could proceed to the next step and molding could be performed. B: The time to reach the target vacuum level was 1.5 times longer than in A, but the vacuum level increased, and the process could proceed to the next step and molding could be performed. C: By adjusting the position of the film and wafer, the vacuum level increased, and the process could proceed to the next step and molding could be performed. D: The vacuum level did not increase, an error occurred, and the device stopped.

[0091] (17) Compression molding process using a back-side compression molding apparatus (Apic Yamada Co., Ltd.: apparatus name "WCM-330MS") is used. The upper release film is placed on the concave upper mold so that its release surface is in contact with the mold resin, and then it is fixed in place by vacuum suction to prevent wrinkles. Next, a laminated film is placed as the lower release film, with its orientation such that the release surface is in contact with the wafer, and then vacuum adsorption is performed. After that, holes are made in the film on the mold using a needle. Next, mold resin (Nagase ChemteX Co., Ltd.: product name "R4604") measured with a dispenser is dropped onto a 12-inch silicon dummy wafer so that the design mold thickness is 1 mm and the dummy chip is covered, and the wafer is placed on the lower mold of the molding die. Next, the lower mold is raised (face up), and a compression molded sample is obtained by vacuum molding. The mold temperature was set to 110°C, the clamping pressure to 100kN, and the curing time to 600 seconds. Five molded samples were prepared using the above method, and the back side of the wafers was observed after the release film was removed and evaluated according to the following criteria. The evaluation method is illustrated in Figure 4. A: The penetration distance of the flash generated by the molding resin on the back side of the wafer is less than 1 mm at all points along the circumference. B: The penetration distance of the flash generated by the molding resin on the back side of the wafer is 1 mm or more and less than 2 mm at all points along the circumference. C: The penetration distance of the flash generated by the molding resin on the back side of the wafer is 2 mm or more and 3 mm or less at all points along the circumference. D: There is one or more points on the circumference where the penetration distance of the flash generated by the molding resin on the back side of the wafer exceeds 3 mm.

[0092] (18) Mold resin chipping during compression molding Using a compression molding apparatus (Apic Yamada Co., Ltd.: apparatus name "WCM-300"), mold resin (Nagase ChemteX Co., Ltd.: product name "R4604"), measured with a dispenser, was dropped onto a 12-inch silicon dummy wafer to cover the dummy chip with a thickness of 1 mm and placed on the lower mold of the molding die. Next, the R-side of the release film was placed on the concave upper mold so as to be in contact with the mold resin, and then it was fixed by vacuum suction to prevent wrinkles, and the lower mold was raised and vacuum molding was performed to obtain a compression molded sample. The mold temperature was 125°C, the mold pressure was 4 MPa, and the curing time was 10 minutes. Five molded samples were prepared using the above method, and the mold resin after peeling off the release film was visually observed for resin chipping at the edges and evaluated according to the following criteria. (Resin chipping) A: No resin chipping was observed in any of the samples.

[0093] B: Resin chipping is observed in one sample.

[0094] C: Resin chipping is observed in two or more samples.

[0095] D: Resin chipping is observed in two or more samples, and in two or more locations on a single sample.

[0096] (19) Film bulge The tent diameter obtained by the method described in (20) below is used to determine whether the film bulge during semiconductor molding is acceptable or not, as follows. Note that A is the best. A: Tent diameter less than 15 mm... There is little film bulge and no thinning of the resin at the edges after molding. B: Tent diameter 15 mm or more and less than 30 mm... A slight thinning of the resin at the edges occurs after molding. C: Tent diameter 30 mm or more and less than 50 mm... Thinning of the resin at the edges occurs but does not pose a practical problem. D: Tent diameter 50 mm or more... There is a large film bulge, which slightly affects practicality.

[0097] (20) Tent diameter Using a vacuum forming machine 300X manufactured by Seikou Sangyo Co., Ltd. and an automatic mold temperature controller KYM-3 manufactured by Kato Riki Seisakusho Co., Ltd., a sample was vacuum formed and the circular shape where the film contacted the plate from the guide pin was marked with an oil-based pen, and the circular area obtained from the marked shape was calculated using the method described in (21) Circular area analysis below. Assuming that the obtained circular area is the area of ​​a perfect circle, the diameter of the circle was calculated from the area of ​​the circle, and the diameter of the circle was taken as the tent diameter. <Vacuum forming machine conditions> Mold: A cylindrical guide pin with a diameter of 3 mm and a height of 4 mm is installed and fixed in the center of a plate with a width of 80 mm x length of 180 mm x thickness of 2 mm. Heater zone 1: 80°C Heater zone 2: 80°C Heater zone 3: 80°C IR heater: 200°C Heating time: 40 seconds Vacuum forming time: 1 minute <Mold temperature control machine conditions> Pump pressure: 0.14 to 0.19 MPa.

[0098] (21) Area analysis of circular shapes Mark a circle with a diameter of 4 cm in one place on the film marked with the oil-based pen near the marked area. Capture the marked film with a camera at a distance of 10 cm with a resolution of 1280 x 960 pixels. Open the captured image with ImagePro 10 from Media Cybernetics and binarize the inside and outside of the two circles. Analyze the area ratio of the inside of the two circles from the binarized data. The area of ​​the circle with a diameter of 4 cm is πr². ２ = 12.56 cm ２ Therefore, we calculate the circular area by multiplying this by the ratio of the area of ​​the circle marked in (20) to the area marked with a diameter of 4 cm. Here, we set π = 3.14.

[0099] (22) Standard deviation of in-plane thickness unevenness of semiconductor package The standard deviation is obtained by measuring the thickness of a semiconductor package manufactured using the laminated film of the present invention at 10 arbitrary locations in the plane that are separated by 1 mm or more using a dial gauge, and calculating the standard deviation from the values ​​of the 10 thickness points.

[0100] (23) Determination of biaxial orientation by laser Raman spectroscopy The orientation parameters defined below are measured under the following conditions. Longitudinal and widthwise cross-sections are cut from the sample to be measured, and the orientation parameters for each direction are calculated by measuring from the cross-sectional direction. Cross-sectional measurements are performed on the surface, center, and back surface, and the orientation degree distribution in the thickness direction is also confirmed. For surface measurements, the polarization angle is rotated in 15-degree steps to measure the angular distribution of the orientation degree on the longitudinal and widthwise surfaces. Using the longitudinal and widthwise orientation parameters obtained from the cross-sectional measurements, the obtained scattering intensity is converted to the orientation parameters for each direction. The orientation parameters are a standardized specification that is unified across all directions and levels, and directly reflect the degree of orientation (not linear with respect to the degree of orientation). If there is no orientation, the value is 1, and a larger value indicates that there are more components oriented in that direction, and those with an orientation parameter greater than 2 are considered to be biaxially oriented. Equipment: T-64000 (Jobin Yvon / Atago Bussan) Conditions: Measurement mode; Micro-Raman objective lens; ×100 Beam diameter; 1 μm Light source; Ar ＋ Laser: 514.5 nm; Laser power: 60 mW; Diffraction grating: Single 1800 gr / mm; Slit: 100 μm; Detector: CCD / Jobin Yvon 1024 × 256; Intensity with polarization parallel to the longitudinal or width direction ((I １６１５ Intensity in polarization parallel and perpendicular to (I １６１５ The ratio of (vertical) is used as a parameter for evaluating the degree of orientation. Orientation parameter R = I １６１５ Parallel / I １６１５ Vertical I １６１５ Parallel: Polarization arrangement parallel to the longitudinal and widthwise plane directions at 1615 cm² －１ Raman band intensity I １６１５ Vertical: 1615 cm² with polarization arrangement perpendicular to the longitudinal and widthwise plane directions. －１ Raman band strength.

[0101] (24) Low molecular weight component content in the film is measured by GPC (gel permeation chromatography). The instrument is a Tosoh HPLC 8120 series, the column is TSKgel superHM-H H4000 / H3000 / H2000 (7.8 mm diameter, 150 mm x 3), the eluent is THF (tetrahydrofuran), the flow rate is 1 mL / min, the injection volume is 20 μL, the detector is RI, the measurement temperature is 40°C, and the pretreatment for measurement is to dissolve the sample in THF, filter it through a 0.45 μm filter to remove additives such as silica, and measure the resin components. The column is stabilized in a heat chamber at 40°C, and THF is flowed into the column at this temperature at a flow rate of 1 mL / min as the solvent, and 50 to 200 μL of the THF sample solution of the resin, which has been prepared to a sample concentration of 0.05 to 0.6 mass%, is injected and measured. To measure the molecular weight of a sample, the molecular weight distribution of the sample is calculated from the relationship between the logarithm of a calibration curve created using several monodisperse polystyrene standard samples and the count. From this, the area percentage (%) of the peak with a molecular weight of less than 2000 is calculated, and this value is taken as the low molecular weight component content in the film.

[0102] The present invention will be described below with reference to examples, but the present invention is not necessarily limited to these examples.

[0103] 1. Polyester Production The polyester resin used for forming layer A was prepared as follows: (Polyester A) Polyethylene terephthalate resin (intrinsic viscosity 0.65) in which 100 mol% of terephthalic acid is the dicarboxylic acid component and 100 mol% of ethylenediol is the diol component.

[0104] (Polyester B) A cyclohexanedimethanol copolymer polyethylene terephthalate resin in which 1,4-cyclohexanedimethanol is copolymerized with respect to the diol component at a concentration of 33 mol% (intrinsic viscosity 0.75).

[0105] (Polyester C) An isophthalic acid copolymer polyethylene terephthalate resin in which the isophthalic acid component is copolymerized with the dicarboxylic acid component at a concentration of 11 mol% (intrinsic viscosity 0.7).

[0106] (Polyester D) A masterbatch containing polyethylene glycol 1000 (molecular weight 1000) at a concentration of 6% by mass in polyester A (intrinsic viscosity 0.62).

[0107] (Olefin A) 4-methyl-1-pentene copolymer resin.

[0108] 2. Manufacturing of Particle Master (Particle Master A) A masterbatch (intrinsic viscosity 0.65) containing aggregated silica particles (specific gravity 2.2) with an average particle size of 1.2 μm in polyester A at a particle concentration of 2% by mass.

[0109] (Particle Master B) A masterbatch containing polystyrene particles with an average particle size of 3.5 μm at a particle concentration of 20% by mass in polyester A (intrinsic viscosity 0.65, Vickers hardness of particles 0.3).

[0110] (Particle Master C) A masterbatch containing acrylic particles (specific gravity 2.2) with an average particle size of 5.2 μm in polyester A at a particle concentration of 25% by mass (intrinsic viscosity 0.65, Vickers hardness of particles 0.2).

[0111] 3. Manufacturing of the release layer coating The coating material used for the release layer was prepared by mixing the following composition.

[0112] (Coating material α-1) A mixture of 10 parts by mass of long-chain alkyl group-containing polyvinyl resin (Lion Specialty Chemicals Co., Ltd.'s "P-Royl" (registered trademark) 1050) on a solid content basis, 2.5 parts by mass of melamine-based crosslinking agent (Sumitomo Chemical Co., Ltd.'s "Sumimar" (registered trademark) M-55) on a solid content basis, 1.5 parts by mass of p-toluenesulfonic acid (Teika Co., Ltd.'s "TAYCACURE" (registered trademark) AC-700) on a solid content basis, 200 parts by mass of toluene, and 70 parts by mass of methyl ethyl ketone.

[0113] 4. Manufacturing of Laminated Films (Examples 1-8, Comparative Examples 1 and 3) Mixed raw materials with the composition and layer structure shown in the table were supplied to separate twin-screw extruders with vents and an oxygen concentration of 0.2 volume%. The polyester resin A layer was melted at a cylinder temperature of 270°C and the polyester resin B layer at a cylinder temperature of 280°C. After the polyester resin A and B layers merged, the short tube temperature was 270°C and the die temperature was 270°C, and the film was extruded in a sheet form from the T-die onto a cooling drum with a temperature controlled to 25°C. At this time, electrostatic discharge was applied using a wire electrode with a diameter of 0.1 mm to ensure close contact with the cooling drum and obtain an unstretched sheet. The side in contact with the drum surface was designated as the D surface, and the opposite side as the ND surface. Next, before stretching in the longitudinal direction, the film temperature was raised with a heating roll, and the film was stretched 3.3 times in the longitudinal direction at a stretching temperature of 85°C. It was then immediately cooled with a metal roll with a temperature controlled to 30°C.

[0114] Next, the film was stretched 3.6 times in the width direction using a tenter-type transverse stretcher at a preheating temperature of 85°C and a stretching temperature of 95°C. It was then heat-treated at a constant length in a 235°C atmosphere for 12 seconds, followed by a 2% relaxation treatment at the same temperature, and then a further 2% relaxation treatment at 200°C to obtain a polyester film with the thickness shown in the table.

[0115] Subsequently, the laminated film was preheated to a surface temperature of 150°C using a radiation heater, and embossing was performed by sandwiching the film between an embossing roll (sand texture) and a metal roll using an induction heating method to the embossing temperature listed in Table 4.

[0116] Next, in order to form a release layer, the laminated film obtained above was cooled to room temperature, then coating material α-1 was applied to the embossed side of the film by gravure coating, the film was transferred to a 110°C oven for pre-drying of the coating, and then heated and dried in a 160°C oven to obtain a laminated film for semiconductor molding with a release layer thickness of 250 nm.

[0117] The properties of the laminated film obtained above are shown in the table, and it was found that the example is a laminated film for semiconductor molding with excellent compression molding properties.

[0118] (Examples 9 and 10) Mixed raw materials with the composition and layer structure shown in the table were supplied to separate twin-screw extruders with an oxygen concentration of 0.2 volume%. The main layer A extruder cylinder temperature was 270°C and the sub-layer B extruder cylinder temperature was 280°C to melt the material. After the main layer A and sub-layer B merged, the short tube temperature was 270°C and the die temperature was 270°C, and the material was extruded in a sheet form onto a cooling drum with a temperature controlled to 25°C from the T-die. At this time, electrostatic discharge was applied using a wire electrode with a diameter of 0.1 mm to ensure close contact with the cooling drum and to obtain an unstretched sheet. The side in contact with the drum surface was designated as the D surface, and the opposite side as the ND surface. Next, before stretching in the longitudinal direction, the film temperature was raised with a heating roll, and the film was stretched 3.3 times in the longitudinal direction at a stretching temperature of 85°C, and immediately cooled with a metal roll with a temperature controlled to 30°C.

[0119] Next, the film was stretched 3.6 times in the width direction using a tenter-type transverse stretcher at a preheating temperature of 85°C and a stretching temperature of 95°C. It was then heat-treated at a constant length in a 235°C atmosphere for 12 seconds, followed by a 2% relaxation treatment at the same temperature, and then a further 2% relaxation treatment at 200°C to obtain laminated films with the thicknesses shown in the table.

[0120] Next, in order to form a release layer, the laminated film obtained above was cooled to room temperature, then coating material α-1 was applied to the D-side of the film by gravure coating, the film was transferred to a 110°C oven for pre-drying, and then heated and dried in a 160°C oven to obtain a laminated film for semiconductor molding with a release layer thickness of 250 nm.

[0121] The properties of the laminated film obtained above are shown in the table, and it was found that the example is a laminated film for semiconductor molding with excellent compression molding properties.

[0122] In Comparative Example 1, the high Young's modulus of the film resulted in poor vacuum adsorption during compression molding, making it impossible to complete the molding process.

[0123] (Comparative Example 2) A biaxially oriented PET (polyethylene terephthalate) film with a thickness of 12 μm (manufactured by Toray Industries, Inc., product name: Lumirror S10) was used as the base film. An unoriented 4-methyl-1-pentene copolymer resin film was used as the release layer. A urethane-based adhesive was used as the adhesive in the dry lamination process to bond the films together. [Urethane-based adhesive A] Main component: Takelac® A-616 (manufactured by Mitsui Chemicals, Inc.). Curing agent: Takenate® A-65 (manufactured by Mitsui Chemicals, Inc.). The main component and the curing agent were mixed in a mass ratio (main component:curing agent) of 16:1, and ethyl acetate was used as a diluent.

[0124] (Manufacturing of laminated film) On one side of a biaxially oriented PET film, a urethane-based adhesive A is applied using gravure coating at a rate of 1.5 g / m². ２ After coating and dry laminating the corona-treated surface of the unstretched 4-methyl-1-pentene copolymer resin film, 1.5 g / m of urethane adhesive A is then applied to the biaxially oriented PET film side of this laminate film. ２ The corona-treated surface of an unstretched 4-methyl-1-pentene copolymer resin film was coated and bonded to the film by dry lamination to obtain a five-layer laminated film (release layer / adhesive layer / base film / adhesive layer / release layer). The dry lamination conditions were a base width of 900 mm, a transport speed of 30 m / min, a drying temperature of 50-60°C, a laminating roll temperature of 50°C, and a roll pressure of 3.0 MPa. The five-layer laminated film (release layer / adhesive layer / base film / adhesive layer / release layer) was obtained using the above method. Subsequently, the laminated film was preheated to a film surface temperature of 150°C using a radiation heater, and embossing was performed by sandwiching the surface temperature between an embossing roll (sand texture) and a metal roll using an induction heating method, at the embossing temperature listed in Table 4.

[0125]

[0126]

[0127]

[0128]

[0129]

[0130]

[0131]

[0132] The present invention provides a laminated film for semiconductor molding that offers excellent design properties, superior moldability during molding, and suppresses film tearing, as well as a method for manufacturing a semiconductor chip encapsulant and a semiconductor. By suitably using such a laminated film as a laminated film for compression molding performed in the semiconductor encapsulation process, the mass production efficiency of semiconductor chips can be improved.

[0133] 1. Mold 2. Guide pin 3. Suction hole 4. Silicon wafer 5. Molding resin 6. Upper release film 7. Tent diameter 8. Lower release film 9. Circular shape in contact with the plate from the guide pin 10. Release film 11. Flash generated by the intrusion of molding resin on the back of the wafer 12. Flash intrusion distance

Claims

1. A laminated film having a base film mainly composed of polyester and a release layer, wherein the mean center surface roughness SRa of at least one surface of the laminated film is 0.01 μm or more and 20.0 μm or less, and the mean center surface roughness SRa measured from at least one surface on the release layer side of the laminated film is reduced by 50.0% or more after heating and pressing using the following method. (Heating and pressing method) Using a press machine heated to a temperature of 125°C for both the upper and lower molds, a three-layer structure consisting of "SUS304 plate with a thickness of 0.5 mm and an arithmetic mean roughness Ra of 0.1 μm" / laminated film / "SUS304 plate with a thickness of 0.5 mm and an arithmetic mean roughness Ra of 0.1 μm" is placed between the upper and lower molds. The SUS304 plate used must have a hairline finish and a maximum height Rz (JIS B0601-2001) of 2 μm or less. After a preheating time of 5 minutes, a heating press is performed for 10 minutes under conditions of 4.0 MPa.

2. The number of protrusions with a height of 0.3 μm to 1.6 μm, measured from at least one surface of the laminated film on the release layer side, is 50 per 800 μm. ２ More than 5000 pieces / 80089μm ２ The laminated film according to claim 1, which is as follows:

3. The laminated film according to claim 1 or 2, wherein the average center surface roughness SRa measured from at least one release layer side surface of the laminated film is 1.7 μm or more and 10.0 μm or less.

4. The laminated film according to claim 1 or 2, wherein the mean center surface roughness SRa on at least one release layer side surface of the laminated film is 1.0 μm or more lower after heating and pressing by the following method than the value before heating and pressing. (Heating and pressing method) Using a press machine heated to a temperature of 125°C for both the upper and lower molds, a three-layer structure consisting of "SUS304 plate with a thickness of 0.5 mm and an arithmetic mean roughness Ra of 0.1 μm" / laminated film / "SUS304 plate with a thickness of 0.5 mm and an arithmetic mean roughness Ra of 0.1 μm" is placed between the upper and lower molds. The SUS304 plate used is hairline finished and has a maximum height Rz (JIS B0601-2001) of 2 μm or less. With a preheating time of 5 minutes, heating and pressing is performed for 10 minutes under conditions of 4.0 MPa.

5. The number of protrusions SPc with a height of 0.4 μm or more and less than 2.0 μm, measured from at least one release layer surface of the laminated film, is 20 per mm. ２ More than 100 pieces / mm ２ The laminated film according to claim 1 or 2, wherein the following applies:

6. The laminated film according to claim 1 or 2, wherein the base film has a laminated structure comprising at least a main layer A and a sub-layer B.

7. The laminated film according to claim 6, wherein the surface orientation coefficient of the sublayer B of the base film is 0.15 or more and 0.17 or less.

8. The laminated film according to claim 1 or 2, wherein in the tanδ-temperature curve obtained from dynamic viscoelasticity measurement under the following measurement conditions, there are two peaks, with the low-temperature peak being called peak A and the high-temperature peak being called peak B, the peak top temperature of peak A is less than 100°C and the peak top temperature of peak B is 100°C or higher. (Dynamic viscoelasticity measurement conditions) Heating temperature: 20°C to 200°C Heating rate: 3°C / min Sampling frequency: 1 second Measurement frequency: 1 Hz 9. Bending stiffness in the MD and TD directions is 10 × 10 －３ N・mm ２ The above 150 x 10 －３ N・mm ２ The laminated film according to claim 1 or 2, wherein the following applies:

10. The laminated film according to claim 1 or 2, wherein the puncture strength measured by the method described in JIS Z1707 (1997) is 2N or more and 5N or less.

11. The laminated film according to claim 1 or 2, used as a laminated film for semiconductor compression molding.

12. A semiconductor manufacturing method comprising a step of using a laminated film having a base film mainly composed of polyester and a release layer, wherein the mean center surface roughness SRa of at least one surface of the laminated film is 0.01 μm or more and 20.0 μm or less, and the mean center surface roughness SRa measured from at least one surface on the release layer side of the laminated film is reduced by 50.0% or more after heating and pressing by the following method. (Heating and pressing method) Using a press machine heated to a temperature of 125°C for both the upper and lower molds, a three-layer structure of "SUS304 plate with a thickness of 0.5 mm and an arithmetic mean roughness Ra of 0.1 μm" / laminated film / "SUS304 plate with a thickness of 0.5 mm and an arithmetic mean roughness Ra of 0.1 μm" is placed between the upper and lower molds. The SUS304 plate used must have a hairline finish and a maximum height Rz (JIS B0601-2001) of 2 μm or less. After a preheating time of 5 minutes, a heating press is performed for 10 minutes under conditions of 4.0 MPa.

13. A method for manufacturing a semiconductor according to claim 12, comprising the step of covering a semiconductor element with a molding resin.

14. The method for manufacturing a semiconductor according to claim 13, wherein the viscosity of the molding resin used in the step of covering the semiconductor element with the molding resin at a temperature of 25°C and a shear rate of 2.5 s －１ is 70 Pa·s or more and 1000 Pa·s or less. －１ ​ 15. A semiconductor molded with a molding resin, wherein the thickness of the molding resin is 0.1 mm or more and 3.0 mm or less, and the element area of ​​the semiconductor is 100 mm². ２ More than 250000mm ２ The semiconductor is as follows, wherein multiple semiconductor elements are connected via an interposer to form a single semiconductor, and the in-plane thickness uniformity standard deviation of the semiconductor is 0.05 μm or more and 1.0 μm or less.

16. The semiconductor according to claim 15, wherein the mold resin is a mold resin in which a spectrum originating from dimethylsiloxane ions is detected by the following measurement method. (Measurement method for mold resin) Apparatus: TOF.SIMS 5 (manufactured by IONTOF) Primary ion: Bi ３＋＋ Secondary ion polarity: Negative only Etching ions: Ar Gas cluster ion beam (Ar-GCIB) 17. A laminated film having a base film and a release layer, wherein the average center surface roughness SRa of at least one surface of the laminated film is 0.01 μm or more and 20.0 μm or less, and the average center surface roughness SRa measured from at least one surface of the laminated film on the release layer side is reduced by 50.0% or more after heating and pressing using the following method, and the bending stiffness in the MD direction and TD direction is 10 × 10 －３ N・mm ２ The above 150 x 10 －３ N・mm ２ The laminated film is as follows. (Heating press method) Using a press machine with both the upper and lower die temperatures heated to 125°C, a three-layer structure consisting of "SUS304 plate with a thickness of 0.5 mm and an arithmetic mean roughness Ra of 0.1 μm" / laminated film / "SUS304 plate with a thickness of 0.5 mm and an arithmetic mean roughness Ra of 0.1 μm" is placed between the upper and lower dies. The SUS304 plate used is hairline finished and has a maximum height Rz (JIS B0601-2001) of 2 μm or less. With a preheating time of 5 minutes, heating press is performed for 10 minutes under conditions of 4.0 MPa.

Images