CN116806367A

CN116806367A - Release film

Info

Publication number: CN116806367A
Application number: CN202180090710.6A
Authority: CN
Inventors: 前岨晋一; 冈田润; 佐藤基
Original assignee: Sumitomo Bakelite Co Ltd
Current assignee: Sumitomo Bakelite Co Ltd
Priority date: 2021-01-14
Filing date: 2021-12-13
Publication date: 2023-09-26
Also published as: JP2022182520A

Abstract

The release film (10) of the present invention has a multilayer structure in which a release layer (1), a 1 st base material layer (3), and a 2 nd base material layer (2) are laminated in this order, the release layer (1) constituting a release surface (11) of the release film (10), the 2 nd base material layer (2) constituting a surface (21) of the release film (10) on the opposite side from the release surface (11), the release layer (1) containing 1 or 2 or more selected from silicone resins, fluorine resins, melamine resins, epoxy resins, and phenolic resins, the 1 st base material layer (3) being composed of a stretched or unstretched film containing 1 or 2 or more selected from polyester resins, polyolefin resins, and polyamide resins, and the 2 nd base material layer (2) being composed of a stretched or unstretched film containing 1 or 2 or more selected from polyester resins, polyolefin resins, and polyamide resins.

Description

Release film

Technical Field

The present invention relates to a release film.

Background

Conventionally, various techniques have been developed in the field of release films. For example, in the field of a manufacturing process of a semiconductor device, it is known to manufacture a molded body by disposing a release film between a mold and a molded object, and resin-encapsulating the molded object on which electronic components such as semiconductor elements are mounted by a molding method such as a transfer molding method or a compression molding method (for example, patent documents 1 to 3). The mold release film is disposed between the mold and the molding object, and after the resin encapsulation, the molded article can be easily removed from the mold. The release film used for resin molding using such a mold is also commonly referred to as a mold release film for molding.

Prior art literature

Patent literature

Patent document 1: japanese patent application laid-open No. 2020-151949.

Patent document 2: japanese patent application laid-open No. 2020-19264.

Patent document 3: japanese patent laid-open publication No. 2016-092272.

Disclosure of Invention

Problems to be solved by the invention

However, wrinkles and distortions generated in the release film may be transferred to the surface of a molded article obtained using a conventional release film, and there is room for improvement from the viewpoint of obtaining a molded article having a good appearance at a higher level.

Means for solving the problems

The present inventors have conducted intensive studies on the causes of wrinkles and distortions generated in a release film, and have found that the following problems exist.

In general, a suction port for vacuum evacuation is provided around the cavity recess of the lower mold so that the release film is vacuum-sealed to the inner surface of the cavity recess. After the release film is disposed so as to cover both the cavity recess and the suction port around the cavity recess, air between the release film and the cavity recess is sucked from the suction port, and vacuum-evacuation is performed, whereby the release film can be vacuum-adhered to the inner surface of the cavity recess. In this vacuum evacuation, the release film is sucked into the suction port to some extent, but if the deformation amount of the release film is insufficient, a part of the release film is sucked into the suction port, and the end portion of the release film near the suction port may rise. As a result, it was found that a small gap was generated between the end of the rising mold release film and the lower mold, and suction was not performed sufficiently, so that the adhesion between the mold release film and the cavity concave portion was lowered, and wrinkles and the like were likely to occur in the mold release film.

Further, a molding object on which electronic components such as semiconductor elements are mounted is held in the upper die. The molding object is clamped from the up-down direction by a lower die filled with a sealing resin material in a cavity concave portion and an upper die fixed with the molding object, and compression molding is performed to perform resin molding. At this time, pressure is applied by raising the base of the lower die to compress the encapsulating resin material. At this time, the depth of the cavity becomes shallow, and therefore a minute gap is generated between the mold release film and the inner surface of the cavity concave portion. Therefore, it is known that deformation occurs in the release film, and this causes distortion and wrinkles.

Therefore, the release film disposed on the mold is required to have sufficient flexibility and elongation to cope with local deformation.

On the other hand, according to the present inventors, there is a tendency that, when the flexibility and elongation of the release film are to be improved, there is a limitation that the thickness of the release film must be reduced, and when the film is made thin, the operability is lowered because the stiffness of the film cannot be sufficiently ensured, and the like.

Accordingly, the present inventors have further studied from the viewpoint of the workability of a molded article having a good appearance and a release film by a release film, and found that it is effective to determine and combine a release layer constituting a release surface of a release film, a 2 nd base material layer constituting the surface opposite to the release layer, and a 1 st base material layer interposed therebetween.

According to the 1 st aspect of the present invention, there is provided a release film having a multilayer structure in which a release layer, a 1 st base material layer, and a 2 nd base material layer are laminated in this order, wherein the release layer forms a release surface of the release film, the 2 nd base material layer forms a surface of the release film opposite to the release surface, the release layer contains 1 or 2 or more kinds selected from silicone resins, fluorine resins, melamine resins, epoxy resins, phenol resins, and acrylic resins, the 1 st base material layer is formed of a stretched or unstretched film containing 1 or 2 or more kinds selected from polyester resins, polyolefin resins, and polyamide resins, and the 2 nd base material layer is formed of a stretched or unstretched film containing 1 or 2 or more kinds selected from polyester resins, polyolefin resins, and polyamide resins.

The inventors of the present invention have studied intensively about the causes of wrinkles and distortions generated in a release film, and have found that the following problems exist.

Accordingly, the present inventors have further studied from the viewpoint of solving the problem, and as a result, have newly devised a ratio of a predetermined tensile strength to a predetermined breaking strength as an index for controlling the properties of a release film. Further, it has been found that by controlling these indices simultaneously, sufficient elongation (deformation) is obtained with respect to stress at the time of mold fitting and recovery (elastic recovery) to the original shape is obtained with respect to elongation, whereby occurrence of wrinkles of the release film can be suppressed, and the present invention has been completed. It has also been found that by controlling the new index, the occurrence of wrinkles and distortions in the release film can be effectively suppressed, not limited to the use in the above-described production method.

According to the invention of the present invention 2, there can be provided a release film satisfying the following (a) to (b).

(a) The release film has a 5% tensile strength (5% modulus) at 180 ℃ of 1.0MPa or more and 5.0MPa or less.

(b) When the breaking strength at 25 ℃ is X1 (MPa), the breaking strength at 180 ℃ is X2 (MPa), and (1- (X1-X2)/X1) is alpha 1, alpha 1 is not less than 0.20 and not more than 0.80.

The inventors of the present invention have studied intensively about the cause of wrinkles and distortions generated in a release film, and have found that the following problems exist.

Accordingly, the present inventors have further studied from the viewpoint of solving the problem, and as a result, have newly devised 2 indices related to the difference in dimensional change amount at a predetermined temperature, focusing on a thermo-mechanical analysis (TMA) curve of a predetermined condition as indices for controlling the properties of a release film. Further, it has been found that by controlling these indices separately, it is possible to obtain sufficient elongation (deformation) with respect to stress at the time of mold fitting and to recover (elastic recovery) to an original shape with respect to elongation, thereby suppressing the occurrence of wrinkles of a release film, and the present invention has been completed. It has also been found that by controlling the new index, the occurrence of wrinkles and distortions in the release film can be effectively suppressed, not limited to the use in the above-described production method.

According to the invention of claim 3, there is provided a release film, wherein the following (a) is satisfied in a TMA curve obtained from a relationship between a temperature measured by stretching a release film at a temperature rise rate of 2 ℃/min and a load of 500mN in a thermo-mechanical analysis (TMA) measurement and a dimensional change amount of a length of the release film.

(a) When the dimensional change at 170℃is X1 (%), the dimensional change at 190℃is X2 (%), and (X2-X1)/(190-170) is α1, α1 is 0.1 to 1.0.

Further, according to the invention of claim 4, there is provided a release film, wherein the following (b) is satisfied in a TMA curve obtained from a relationship between a temperature measured by stretching the release film at a temperature rise rate of 2 ℃/min and a load of 500mN in a thermo-mechanical analysis (TMA) measurement and a dimensional change amount of a length of the release film.

(b) The change in size at 170℃is X1 (%), the change in size at 190℃is X2 (%), the change in size at (X2-X1)/(190-170) is alpha 1, the change in size at 25℃is X3 (%), the change in size at 100℃is X4 (%), and the change in size at (X4-X3)/(100-25) is alpha 2, whereby alpha 1/alpha 2 is 6 to 35.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, there is provided a release film which can provide a molded article having a good appearance while improving the handleability of the release film.

Drawings

Fig. 1 is a cross-sectional view schematically showing a cross-section of a release film according to embodiment 1.

Fig. 2 is a cross-sectional view schematically showing a cross-section of a release film according to embodiment 2.

Fig. 3 is a cross-sectional view schematically showing a cross-section of a release film according to embodiment 3.

Detailed Description

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

In all the drawings, the same constituent elements are denoted by the same reference numerals, and description thereof is omitted as appropriate. In order to avoid complication, when a plurality of identical components are present in the same drawing, only 1 of the components may be given reference numerals, and all the components may not be given reference numerals. The drawings are for illustration only. The shapes, size ratios, etc. of the respective components in the drawings do not necessarily correspond to actual articles.

In the present specification, unless otherwise specified, the expression "a to b" in the description of the numerical range indicates a or more and b or less. For example, "1 to 5 mass%" means "1 mass% or more and 5 mass% or less".

In the present specification, the MD direction means the longitudinal direction (Machine Direction) and means the flow direction (longitudinal direction) at the time of film formation, and the TD direction means the transverse direction (Transverse Direction) and means the vertical direction.

Embodiment 1

< Release film >)

As shown in fig. 1, the release film 10 of the present embodiment has a multilayer structure in which the release layer 1, the 1 st base material layer 3, and the 2 nd base material layer 2 are laminated in this order, and the release layer 1 forms the release surface 11 of the release film 10, and the 2 nd base material layer 2 forms the surface 21 of the release film 10 opposite to the release surface 11.

In the present embodiment, the release film 10 having a three-layer structure in which the release layer 1, the 1 st base material layer 3, and the 2 nd base material layer 2 are laminated in this order is described, but the release layer 1 and the 2 nd base material layer 2 may constitute the outer surfaces of the release film 10, and a layer other than the 1 st base material layer 3 may be interposed between the release layer 1 and the 2 nd base material layer 2.

The release film 10 of the present embodiment preferably has a dimensional change rate of 4 to 40%, more preferably 5 to 35%, and even more preferably 7 to 30% under 180 ℃ conditions when the temperature is raised from 30 ℃ to 180 ℃ at 2 ℃/min, with a tensile load of 500mN by Thermal Mechanical Analysis (TMA).

By setting the dimensional change rate within the above-described numerical range, good follow-up property with respect to the mold can be obtained when the release film 10 is placed on the mold while maintaining operability, and occurrence of wrinkles and distortions in the release film 10 can be suppressed, and transfer of wrinkles and distortions in the release film 10 to the molded article can be suppressed. As a result, a molded article having a good appearance can be obtained. When the mold release film 10 is vacuum-sealed to the inner surface of the cavity concave portion, the mold release film 10 is sucked into the deep groove even when the suction port of the mold is the relatively deep groove. Therefore, the release film 10 is required to be sufficiently elongated locally, but this can be achieved by the release film 10 of the present embodiment.

In addition, in the release film 10 of the present embodiment, when dynamic viscoelasticity (DMA) measurement is performed under the conditions that the temperature rising rate is 5 ℃/min and the frequency is 1Hz, the storage modulus at 180 ℃ is preferably 10 to 500MPa, more preferably 70 to 400MPa.

The storage modulus of the release film 10 at 180 ℃ refers to the storage modulus when the release film 10 is disposed in a mold and compressed by heating.

By setting the storage modulus of the release film 10 at 180 ℃ within the above-described numerical range, it is possible to maintain good release properties and cushioning properties while improving mold following properties at the time of vacuum sealing.

Further, the release film 10 of the present embodiment preferably has a value measured by the ring stiffness test of 2mN/cm or more, more preferably 5mN/cm or more, and still more preferably 10mN/cm or more. This can improve the operability of the film.

On the other hand, the upper limit value of the value measured by the ring stiffness test is not particularly limited, but may be, for example, 100mN/cm or less or 80mN/cm or less from the viewpoint of maintaining the properties as a release film.

The dimensional change rate, storage modulus, and ring stiffness of the release film 10 according to the present embodiment can be achieved by, for example, selecting and combining known methods such as the types of raw materials of the release layer 1, the 1 st base material layer 3, and the 2 nd base material layer 2, the film forming method, the control of the surface roughness of the release film 10, and the method for producing the release film 10, as different methods from the conventional methods.

For example, as a film forming method, when a film is stretched, a film having hardness and stiffness can be produced as compared with an unstretched film. In order to improve the handling properties of the release film 10, the surface states of the release surface 11 of the release layer 1 and the surface 21 of the 2 nd base material layer 2 constituting the outer surface of the release film 10 are controlled, and the 1 st base material layer 3 is given stiffness while the surface roughness and the puckerability are set to predetermined states. As an example of the method for producing the release film 10 according to the present embodiment, a coating liquid of the 1 st resin composition constituting the release layer 1 may be applied to the tape-like laminate of the 2 nd base layer 2 and the 1 st base layer 3 in a roll-to-roll manner. At this time, if at least one of the 2 nd and 1 st base material layers 2 and 3 is an unstretched film, tension based on the roll-to-roll system is easily applied to the 2 nd and 1 st base material layers 2 and 3. Therefore, by setting the transfer tension of the roll-to-roll type roll to 100N or less, the stress applied to the 2 nd and 1 st base material layers 2 and 3 can be reduced, and the desired release film 10 can be obtained.

The thickness of the release film 10 is preferably 5 μm or more and 150 μm or less, more preferably 10 μm or more and 100 μm or less, and still more preferably 15 μm or more and 80 μm or less.

The details of each layer included in the release film 10 of the present embodiment will be described below.

[ Release layer 1]

In the present embodiment, the release layer 1 is a resin layer that forms one surface 11 of the release film 10 and that forms a surface on the side that contacts the encapsulating resin (the molded article to be formed later) when the release film 10 is placed on a mold.

The thickness of the release layer 1 is preferably 0.01 to 50. Mu.m, more preferably 0.05 to 30. Mu.m, still more preferably 0.08 to 25. Mu.m, still more preferably 0.1 to 15. Mu.m.

By setting the thickness of the release layer 1 to the above lower limit or more, the required releasability of the release film 10 can be imparted. On the other hand, by controlling the rigidity of the release film 10 by setting the thickness of the release layer 1 to the above-described upper limit value or less, the balance between the mold following property and the release property can be improved.

Further, from the viewpoints of releasability and good appearance of the molded article, the surface roughness Ra of the surface 11 of the release film 10 on the release layer 1 side is preferably 0.3 to 2 μm, more preferably 0.4 to 1.5 μm, and even more preferably 0.5 to 1.2 μm.

By setting the surface roughness Ra of the surface 11 to the above lower limit value or more, the mold release property and the mold follow-up property at the time of molding can be well balanced. On the other hand, by setting the surface roughness Ra of the surface 11 to the above-described upper limit value or less, the balance between releasability and good appearance of the molded article can be made good.

In addition, from the viewpoint of imparting gloss to the appearance of the molded article obtained using the release film 10, the surface roughness Ra of the surface 11 is preferably less than 0.2 μm.

The method for controlling the surface roughness of the surface 11 on the release layer 1 side can be adjusted by a known method such as transferring an embossed pattern to a film using a roller subjected to embossing in the step of producing a release film, or blending particles into the material of the release layer.

For the surface roughness Ra of the release layer 1, according to JIS B0601: 2013.

In the present embodiment, the release layer 1 is composed of the 1 st resin composition containing a resin.

The release layer 1 contains 1 or 2 or more resins selected from silicone resins, fluorine resins, melamine resins, epoxy resins, phenolic resins, and acrylic resins as resins. Among them, from the viewpoint of obtaining a good appearance of the molded article and improving the handleability of the release film 10, 1 or 2 or more kinds selected from silicone resins, melamine resins, and acrylic resins are preferably contained, and melamine resins or acrylic resins are more preferably contained.

(Silicone resin)

The silicone resin is not particularly limited. For example, compounds containing 2 or more siloxane bonds (-Si-O-) such as various known or commercially available siloxane polymers can be used.

As the silicone resin, for example, 1 or 2 selected from the group consisting of a vinyl group-containing organopolysiloxane (a) and an organohydrogen polysiloxane (B) are preferably contained. Thus, characteristics such as elasticity and compressibility of silicone, such as rubber, can be obtained, and sufficient elongation and shape recovery property with respect to elongation of the release film can be more easily obtained.

Vinyl group-containing organopolysiloxane (A)

The vinyl group-containing organopolysiloxane (a) may contain a vinyl group-containing linear organopolysiloxane (A1) having a linear structure.

The vinyl group-containing linear organopolysiloxane (A1) has a linear structure and contains vinyl groups, which become crosslinking points upon curing.

The vinyl group content of the linear organopolysiloxane (A1) containing vinyl groups is not particularly limited, but is preferably, for example, 15 mol% or less and having 2 or more vinyl groups in the molecule. Thus, the amount of vinyl groups in the vinyl group-containing linear organopolysiloxane (A1) is optimized, and a network with each component described later can be formed reliably.

In the present specification, the vinyl group content is the mol% of the vinyl group-containing siloxane units when 100 mol% of all units constituting the vinyl group-containing linear organopolysiloxane (A1) are used. However, each vinyl-containing siloxane unit is considered to be 1 vinyl group.

The polymerization degree of the vinyl group-containing linear organopolysiloxane (A1) is not particularly limited, but is preferably in the range of about 1000 to 10000, more preferably about 2000 to 5000, for example. The polymerization degree can be obtained as a number average polymerization degree (or a number average molecular weight) in terms of polystyrene in GPC (gel permeation chromatography) using chloroform as a developing solvent, for example.

The specific gravity of the vinyl group-containing linear organopolysiloxane (A1) is not particularly limited, but is preferably in the range of about 0.9 to 1.1.

The use of a linear organopolysiloxane (A1) containing vinyl groups, which has a polymerization degree and specific gravity within the above-described ranges, can improve the heat resistance, flame retardancy, chemical stability, and the like of the obtained silicone rubber.

The vinyl group-containing linear organopolysiloxane (A1) is preferably one having a structure represented by the following formula (1).

In the formula (1), R ¹ Is a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, alkenyl group, aryl group, or hydrocarbon group obtained by combining these. Examples of the alkyl group having 1 to 10 carbon atoms include methyl, ethyl, propyl, and the like, and among them, methyl is preferable. Examples of the alkenyl group having 1 to 10 carbon atoms include vinyl, allyl, and butenyl groups, and among them, vinyl groups are preferable. Examples of the aryl group having 1 to 10 carbon atoms include phenyl group and the like.

And R is ² Is a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, alkenyl group, aryl group, or hydrocarbon group obtained by combining these. Examples of the alkyl group having 1 to 10 carbon atoms include methyl, ethyl, propyl, and the like, and among them, methyl is preferable. Examples of the alkenyl group having 1 to 10 carbon atoms include vinyl, allyl and butenyl. Examples of the aryl group having 1 to 10 carbon atoms include phenyl groups.

And R is ³ Is a substituted or unsubstituted alkyl group having 1 to 8 carbon atoms, an aryl group, or a hydrocarbon group obtained by combining these groups. Examples of the alkyl group having 1 to 8 carbon atoms include methyl, ethyl, propyl, and the like, and among them, methyl is preferable. Examples of the aryl group having 1 to 8 carbon atoms include phenyl groups.

Further, R in the formula (1) ¹ R is R ² Examples of the substituent(s) include methyl and vinyl, and R is ³ Examples of the substituent(s) include methyl.

In the formula (1), R is plural ¹ Independent of each other, may be different from each other, or may be the same. And for R ² R is R ³ The same is true for the same.

M and n are the number of repeating units constituting the vinyl group-containing linear organopolysiloxane (A1) represented by formula (1), m is an integer of 0 to 2000, and n is an integer of 1000 to 10000. m is preferably from 0 to 1000 and n is preferably from 2000 to 5000.

The specific structure of the vinyl group-containing linear organopolysiloxane (A1) represented by the formula (1) is, for example, a structure represented by the following formula (1-1).

In the formula (1-1), R ¹ R is R ² Each independently represents methyl or vinyl, at least one of which is vinyl.

The vinyl group-containing linear organopolysiloxane (A1) may contain A1 st vinyl group-containing linear organopolysiloxane (A1-1) having a vinyl group content of 2 or more vinyl groups in the molecule and 0.4 mol% or less. The vinyl group content of the linear organopolysiloxane (A1-1) containing vinyl groups of the 1 st may be 0.1 mol% or less.

The vinyl group-containing linear organopolysiloxane (A1) may contain A1 st vinyl group-containing linear organopolysiloxane (A1-1) and a 2 nd vinyl group-containing linear organopolysiloxane (A1-2) having a vinyl group content of 0.5 to 15 mol%.

The raw rubber as a raw material of the silicone rubber can be made uneven in vinyl groups by combining the 1 st linear organopolysiloxane (A1-1) containing vinyl groups and the 2 nd linear organopolysiloxane (A1-2) containing vinyl groups, which is high in vinyl groups, and can more effectively form a density of crosslinked density in a crosslinked network of the silicone rubber. As a result, the tear strength of the release film is more effectively improved, and the dimensional stability and transferability are easily controlled.

Specifically, as the vinyl group-containing linear organopolysiloxane (A1), for example, it is preferable to use: 1 st vinyl group-containing linear organopolysiloxane (A1-1), in the above formula (1-1), R is ¹ Units being vinyl and/or R ² A unit which is a vinyl group has 2 or more units in a molecule and contains 0.4 mol% or less; and a vinyl group-containing linear organopolysiloxane (A1-2) containing 0.5 to 15 mol% of R ¹ Units being vinyl and/or R ² Units that are vinyl.

The vinyl group content of the linear organopolysiloxane (A1-1) containing vinyl groups of the 1 st is preferably 0.01 to 0.2 mol%. The vinyl group content of the linear organopolysiloxane (A1-2) containing vinyl groups of the 2 nd is preferably 0.8 to 12 mol%.

When the vinyl group-containing linear organopolysiloxane (A1-1) of the 1 st and the vinyl group-containing linear organopolysiloxane (A1-2) of the 2 nd are blended in combination, the ratio of (A1-1) to (A1-2) is not particularly limited, but, for example, the ratio of (A1-1): to (A1-2) is preferably 50:50 to 95:5, more preferably 80:20 to 90:10 in terms of weight ratio.

The vinyl group-containing linear organopolysiloxane (A1-1) and the vinyl group-containing linear organopolysiloxane (A1-2) of the 1 st and the 2 nd may be used alone or in combination of 1 or more than 2 kinds.

The vinyl group-containing organopolysiloxane (a) may contain a vinyl group-containing branched organopolysiloxane (A2) having a branched structure.

Organopolysiloxane (B)

The organohydrogen polysiloxane (B) is classified into a linear organohydrogen polysiloxane (B1) having a linear structure and a branched organohydrogen polysiloxane (B2) having a branched structure, and can include either or both of these.

The linear organopolysiloxane (B1) has a linear structure and has a structure in which hydrogen is directly bonded to Si (≡si—h), and is a polymer in which a hydrosilylation reaction is performed with a vinyl group contained in a component contained in a raw material of the release layer 1 in addition to the vinyl group of the vinyl-containing organopolysiloxane (a) to crosslink the component.

The molecular weight of the linear organopolysiloxane (B1) is not particularly limited, but for example, the weight average molecular weight is preferably 20000 or less, more preferably 1000 or more and 10000 or less.

The weight average molecular weight of the linear organopolysiloxane (B1) can be measured, for example, by conversion to polystyrene in GPC (gel permeation chromatography) using chloroform as a developing solvent.

Further, the linear organopolysiloxane (B1) is preferably generally free of vinyl groups. This can reliably prevent the crosslinking reaction from proceeding in the molecule of the linear organopolysiloxane (B1).

As the linear organopolysiloxane (B1) as described above, for example, a substance having a structure represented by the following formula (2) can be preferably used.

In the formula (2), R ⁴ Is a C1-10 substituted or unsubstituted alkyl group, alkenyl group, aryl group, or a hydrocarbon group or hydride group obtained by combining these groups. Examples of the alkyl group having 1 to 10 carbon atoms include methyl, ethyl, propyl, and the like, and among them, methyl is preferable. Examples of the alkenyl group having 1 to 10 carbon atoms include vinyl, allyl, and butenyl. Examples of the aryl group having 1 to 10 carbon atoms include phenyl groups.

And R is ⁵ Is a C1-10 substituted or unsubstituted alkyl group, alkenyl group, aryl group, or a hydrocarbon group or hydride group obtained by combining these groups. Examples of the alkyl group having 1 to 10 carbon atoms include methyl, ethyl and propyl groups, and among them, methyl is preferred. Examples of the alkenyl group having 1 to 10 carbon atoms include vinyl, allyl, and butenyl. Examples of the aryl group having 1 to 10 carbon atoms include phenyl groups.

In the formula (2), R is plural ⁴ Independent of each other, may be different from each other, or may be the same. For R ⁵ The same is true for the same. However, a plurality of R ⁴ R is R ⁵ At least 2 or more of them are hydride groups.

And R is ⁶ Is a substituted or unsubstituted alkyl group having 1 to 8 carbon atoms, an aryl group, or a hydrocarbon group obtained by combining these groups. Examples of the alkyl group having 1 to 8 carbon atoms include methyl, ethyl, propyl, and the like, and among them, methyl is preferable. Examples of the aryl group having 1 to 8 carbon atoms include phenyl groups. Multiple R' s ⁶ Independent of each other and can be different from each otherThe same may be applied.

In addition, R in formula (2) ⁴ 、R ⁵ 、R ⁶ Examples of the substituent(s) include methyl and vinyl, and methyl is preferred from the viewpoint of preventing crosslinking reaction in the molecule.

M and n are the number of repeating units constituting the linear organohydrogen polysiloxane (B1) represented by the formula (2), m is an integer of 2 to 150, and n is an integer of 2 to 150. Preferably, m is an integer of 2 to 100, and n is an integer of 2 to 100.

The linear organopolysiloxane (B1) may be used alone in an amount of 1 or 2 or more.

The branched organohydrogen polysiloxane (B2) has a branched structure, and thus forms a region having a high crosslinking density, and is a component of a dense structure that greatly contributes to the crosslinking density in a system that forms silicone rubber. In addition, as in the case of the linear organopolysiloxane (B1), the linear organopolysiloxane (B1) has a structure in which hydrogen is directly bonded to Si (≡si—h), and is a polymer in which a hydrosilylation reaction is performed with a vinyl group of a component contained in a raw material of the release layer 1 in addition to a vinyl group of the vinyl-containing organopolysiloxane (a) to crosslink the component.

The specific gravity of the branched organohydrogen polysiloxane (B2) is in the range of 0.9 to 0.95.

Further, the branched organohydrogen polysiloxane (B2) is generally preferably not having vinyl groups. This can reliably prevent the crosslinking reaction from proceeding in the molecule of the branched organopolysiloxane (B2).

The branched organohydrogen polysiloxane (B2) is preferably a compound represented by the following average composition formula (c).

Average composition (c)

(H _a (R ⁷ ) _3-a SiO _1/2 ) _m (SiO _4/2 ) _n

(in the formula (c), R ⁷ Is a monovalent organic group, a is an integer in the range of 1 to 3, m is H _a (R ⁷ ) _3-a SiO _1/2 The number of units, n is SiO _4/2 Number of units)

In formula (c), R ⁷ The monovalent organic group is preferably a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, an aryl group, or a hydrocarbon group obtained by combining these groups. Examples of the alkyl group having 1 to 10 carbon atoms include methyl, ethyl, propyl, and the like, and among them, methyl is preferable. Examples of the aryl group having 1 to 10 carbon atoms include phenyl groups.

In the formula (c), a is the number of hydride groups (hydrogen atoms directly bonded to Si), and is an integer in the range of 1 to 3, preferably 1.

In the formula (c), m is H _a (R ⁷ ) _3-a SiO _1/2 The number of units, n is SiO _4/2 Number of units.

The branched organopolysiloxane (B2) has a branched structure. The linear organopolysiloxane (B1) differs from the branched organopolysiloxane (B2) in that the structure is linear or branched, and the number of alkyl groups R bonded to Si (R/Si) is 1.8 to 2.1 in the linear organopolysiloxane (B1) and 0.8 to 1.7 in the branched organopolysiloxane (B2) when the number of Si is 1.

Further, since the branched organohydrogen polysiloxane (B2) has a branched structure, the amount of residue when heated to 1000 ℃ at a heating rate of 10 ℃/min in a nitrogen atmosphere is 5% or more, for example. In contrast, since the linear organopolysiloxane (B1) is linear, the amount of residue after heating under the above conditions becomes almost zero.

Further, specific examples of the branched organohydrogen polysiloxane (B2) include those having a structure represented by the following formula (3).

In the formula (3), R ⁷ Is a substituted or unsubstituted alkyl group having 1 to 8 carbon atoms, an aryl group, a hydrocarbon group obtained by combining these groups, or a hydrogen atom. Examples of the alkyl group having 1 to 8 carbon atoms include methyl and ethylA group, a propyl group, etc., of which methyl group is preferred. Examples of the aryl group having 1 to 8 carbon atoms include phenyl groups. As R ⁷ Examples of the substituent(s) include methyl.

In the formula (3), R is plural ⁷ Independent of each other, may be different from each other, or may be the same.

In the formula (3), the term "-O-Si≡" means that Si has a branched structure extending in three dimensions.

The branched organohydrogen polysiloxane (B2) may be used alone in an amount of 1 or in an amount of 2 or more.

In the linear organopolysiloxane (B1) and the branched organopolysiloxane (B2), the amounts of hydrogen atoms (hydride groups) directly bonded to Si are not particularly limited, respectively.

However, in the release layer 1, the total amount of hydride groups of the linear organopolysiloxane (B1) and the branched organopolysiloxane (B2) is preferably 0.5 to 5 mol, more preferably 1 to 3.5 mol, based on 1 mol of vinyl groups in the linear organopolysiloxane (A1) containing vinyl groups. Thus, a crosslinked network can be reliably formed between the linear organopolysiloxane (B1) and the branched organopolysiloxane (B2) and the vinyl-containing linear organopolysiloxane (A1).

(fluororesin)

Specific examples of the fluorine-based resin include polymers of monomers such as tetrafluoroethylene, hexafluoropropylene, chlorotrifluoroethylene, vinylidene fluoride, vinyl fluoride, and perfluoroalkyl vinyl ether, and copolymers of 2 or more monomers. These may be used alone or in combination of 2 or more.

(Melamine resin)

The melamine resin is obtained, for example, by polycondensing a melamine compound with formaldehyde under neutral or weakly alkaline conditions. Specifically, there may be mentioned alkylated melamine resins such as methylated melamine resins and butylated melamine resins, methylolated melamine resins, alkyl etherified melamine and the like.

Among them, preferred isA methylated melamine resin comprising constituent units derived from methylated melamine. The methylated melamine resin has at least 1 methoxymethyl (-CH) ₂ OCH ₃ ) The average degree of polymerization of the resin is 1.1 to 10.

(epoxy resin)

The epoxy resin may be any of monomers, oligomers, and polymers having 2 or more epoxy groups in 1 molecule, regardless of the molecular weight and molecular structure thereof. Specific examples of such epoxy resins include bisphenol-type epoxy resins selected from bisphenol-a-type epoxy resins, bisphenol-F-type epoxy resins, bisphenol-E-type epoxy resins, bisphenol-S-type epoxy resins, hydrogenated bisphenol-a-type epoxy resins, bisphenol-M-type epoxy resins (4, 4' - (1, 3-phenylenediisopropylene) bisphenol-type epoxy resins), bisphenol-P-type epoxy resins (4, 4' - (1, 4-phenylenediisopropylene) bisphenol-type epoxy resins), bisphenol-Z-type epoxy resins (4, 4' -cyclohexylenebisphenol-type epoxy resins), and the like; novolac type epoxy resins such as phenol novolac type epoxy resins, brominated phenol novolac type epoxy resins, cresol novolac type epoxy resins, tetraphenol ethane type novolac type epoxy resins, and novolac type epoxy resins having a condensed ring aromatic hydrocarbon structure; biphenyl type epoxy resin; aralkyl (aralkylyl) epoxy resins such as xylylene (xylene) epoxy resin and biphenyl aralkyl (biphenyl) epoxy resin; naphthalene ether type epoxy resins, naphthol type epoxy resins, naphthalene diphenol type epoxy resins, 2-to 4-functional epoxy type naphthalene resins, binaphthyl type epoxy resins, naphthalene aralkyl (biphenyl) type epoxy resins and other epoxy resins having a naphthalene skeleton; an anthracene-type epoxy resin; a phenoxy type epoxy resin; dicyclopentadiene type epoxy resins; norbornene-type epoxy resins; adamantane-type epoxy resin; heterocyclic epoxy resins such as fluorene-type epoxy resins, phosphorus-containing epoxy resins, alicyclic epoxy resins, aliphatic chain epoxy resins, bisphenol a novolac-type epoxy resins, bisxylenol-type epoxy resins, triphenol methane-type epoxy resins, trihydroxyphenyl methane-type epoxy resins, tetraphenolethane (tetraphenylol ethane) -type epoxy resins, and triisopropylisocyanate; one or more of epoxypropyl amines such as N, N, N ', N' -tetraepoxypropyl metaxylene diamine, N, N, N ', N' -tetraepoxypropyl bisaminomethyl cyclohexane, and N, N-diglycidyl aniline, copolymers of epoxypropyl (meth) acrylate and a compound having an ethylenically unsaturated double bond, epoxy resins having a butadiene structure, diglycidyl ether compounds of bisphenol, diglycidyl ether compounds of naphthalene bisphenol, and epoxypropyl ether compounds of phenols.

(phenolic resin)

The phenolic resin may include a novolac type phenolic resin selected from phenol novolac resins, cresol novolac resins, t-butylphenol novolac resins, nonylphenol novolac resins, and the like; phenol aralkyl resins such as phenol aralkyl resins having a phenylene skeleton and phenol aralkyl resins having a biphenylene skeleton; one or more of phenolic resins having a condensed polycyclic structure such as naphthalene skeleton and anthracene skeleton.

(acrylic resin)

Specific examples of the acrylic resin include acrylic esters such as acrylic acid, methacrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, and 2-ethylhexyl acrylate; methacrylate esters such as methyl methacrylate, ethyl methacrylate, and butyl methacrylate; and resins composed of monomers such as acrylonitrile, methacrylonitrile and acrylamide. As the constituent monomer of the acrylic resin, 1 or 2 or more monomers in these examples are contained. Further, as constituent monomers of the acrylic resin, monomers other than those exemplified may be contained. And, derivatives of these monomers may be used.

The 1 st resin composition may contain other components in addition to the above resin within a range that does not impair the characteristics of the release film 10. The other components are not particularly limited, but polybutadiene, polyisoprene, polychloroprene, polypentadiene, polybutene, polyisobutylene, polystyrene, isoprene-butadiene copolymer, styrene-isoprene copolymer, polyolefin, derivatives thereof, silicone resins, isocyanate group-containing compounds, epoxy group-containing compounds, amines, carboxylic anhydrides, long-chain alkyl group-containing alcohols can be blended appropriately in addition to particles, coupling agents, acid catalysts, solvents, antistatic agents, leveling agents, dispersants, dyes, antioxidants, flame retardants, thermal conductivity improvers, and the like. The representative components will be described below.

(particles)

The release layer 1 may contain particles. This makes it possible to easily control the surface roughness of the surface 11 of the release film 10 regardless of the film formation method of the release layer 1. That is, in the case where the release layer 1 is a stretched film, it is difficult to emboss the surface 11 of the release film 10 on the release layer 1 side, but by including particles in the release layer 1, the surface roughness can be controlled regardless of whether the release layer 1 is a stretched film or an unstretched film. Further, the surface roughness can be increased more easily according to the particle diameter and the content of the particles than in the case where the surface 11 of the release film 10 on the release layer 1 side is roughened.

Examples of the particles contained in the release layer 1 include particles containing 1 or 2 or more kinds of organic particles and/or inorganic particles selected from the group consisting of melamine resins, polystyrene resins, acrylic resins, polyimide resins, polyester resins, silicone resins, polypropylene resins, polyethylene resins, and fluororesin. The release layer 1 of the present embodiment may contain 1 or 2 or more kinds of these particles.

Examples of the inorganic particles include silicates such as talc, calcined clay, unfired clay, mica, and glass; oxides such as titanium oxide, aluminum oxide, boehmite, and silicon dioxide; carbonates such as calcium carbonate, magnesium carbonate and hydrotalcite; hydroxides such as aluminum hydroxide, magnesium hydroxide, and calcium hydroxide; sulfates or sulfites such as barium sulfate, calcium sulfate, and calcium sulfite; borates such as zinc borate, barium metaborate, aluminum borate, calcium borate, and sodium borate; nitrides such as aluminum nitride, boron nitride, silicon nitride, and carbon nitride; titanate such as strontium titanate and barium titanate. These may be used singly or in combination of 1 kind or 2 or more kinds.

From the viewpoint of improving the adhesion to the release layer 1, the inorganic particles may be subjected to a surface treatment. The surface treatment is appropriately selected according to the organic material constituting the release layer 1, but for example, when melamine resin is contained in the release layer 1, a coupling agent having a functional group such as amine, epoxy, or isocyanate is used. The coupling agent will be described later.

The content of the particles contained in the release layer 1 is preferably 10 to 50% by mass, more preferably 15 to 45% by mass, and even more preferably 20 to 40% by mass, relative to the total amount of the release layer 1.

By setting the particle content to the above lower limit or more, the surface roughness of the surface 11 can be improved, and good releasability and handling properties can be obtained.

On the other hand, by setting the content of the particles to the above upper limit value or less, the film forming property can be maintained well.

In addition, in the case of imparting gloss to a molded article obtained using the release film 10, the content of the particles may be 0 mass%.

(silane coupling agent)

The silane coupling agent may have a hydrolyzable group. The hydrolysis group is hydrolyzed by water to form a hydroxyl group, and the hydroxyl group on the surface of the inorganic particle undergo a dehydration condensation reaction, whereby the surface of the inorganic particle can be modified.

The silane coupling agent may include a silane coupling agent having a reactive group such as a vinyl group, an epoxy group, an isocyanate group, or an amino group. As a result, the inorganic particles surface-modified with the silane coupling agent can react with the resin in the release layer 1, and as a result, the inorganic particles can be prevented from falling off from the release layer 1.

(acid catalyst)

The acid catalyst is not particularly limited, but examples thereof include inorganic acids and organic acids. Examples of the inorganic acid include hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, and the like. Examples of the organic acid include organic carboxylic acid, organic sulfonic acid, and organic phosphoric acid.

Examples of the organic carboxylic acid include oxalic acid, acetic acid, and formic acid. Examples of the organic sulfonic acid include methanesulfonic acid, trifluoromethanesulfonic acid, isoprene sulfonic acid, camphorsulfonic acid, hexane sulfonic acid, octane sulfonic acid, nonane sulfonic acid, decane sulfonic acid, hexadecane sulfonic acid, benzene sulfonic acid, p-toluene sulfonic acid, cumene sulfonic acid, dodecylbenzene sulfonic acid, naphthalene sulfonic acid, and nonylnaphthalene sulfonic acid.

Examples of the organic phosphoric acid include methyl acid phosphate, ethyl acid phosphate, propyl acid phosphate, isopropyl acid phosphate, butyl acid phosphate, butoxy ethyl acid phosphate, octyl acid phosphate, 2-ethylhexyl acid phosphate, decyl acid phosphate, month Gui Jisuan phosphate, stearyl acid phosphate, oleyl acid phosphate, behenyl acid phosphate, nonylphenyl acid phosphate, cyclohexyl acid phosphate, phenoxyethyl acid phosphate, alkoxypolyethylene glycol acid phosphate, bisphenol A acid phosphate, dimethyl acid phosphate, diethyl acid phosphate, dipropyl acid phosphate, diisopropyl acid phosphate, dibutyl acid phosphate, dioctyl acid phosphate, di-2-ethylhexyl acid phosphate, dioctyl acid phosphate, dilauryl Gui Jisuan phosphate, distearyl acid phosphate, diphenyl acid phosphate, and di-nonylphenyl acid phosphate.

Examples of the thermal acid generator include sulfonium salts, benzothiazolium salts, ammonium salts, and phosphonium salts.

The acid catalyst can be used alone or in combination of 2 or more.

(solvent)

According to the method for producing the release layer 1, the 1 st resin composition may contain a solvent, for example. When the solvent is contained, the release layer 1 can be produced by dissolving the 1 st resin composition in the solvent and applying the solution.

The solvent is not limited, and specific examples thereof include aliphatic hydrocarbons such as water, pentane, hexane, cyclohexane, heptane, methylcyclohexane, ethylcyclohexane, octane, decane, dodecane and tetradecane; aromatic hydrocarbons such as benzene, toluene, ethylbenzene, xylene, trifluoromethylbenzene, and benzotrifluoride; ethers such as diethyl ether, diisopropyl ether, dibutyl ether, cyclopentyl methyl ether, cyclopentyl ethyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, 1, 4-dioxane, 1, 3-dioxane, and tetrahydrofuran; haloalkanes such as dichloromethane, chloroform, 1-dichloroethane, 1, 2-dichloroethane, 1-trichloroethane and 1, 2-trichloroethane; carboxylic acid amides such as N, N-dimethylformamide and N, N-dimethylacetamide; sulfoxides such as dimethyl sulfoxide and diethyl sulfoxide; alcohols such as ethanol, isopropanol, butanol, etc. These may be used alone or in combination of 2 or more.

[ substrate layer 2]

In the present embodiment, the 2 nd base material layer 2 is a resin layer that forms one surface 21 of the release film 10 and that forms a surface on the side that contacts the mold when the release film 10 is placed on the mold.

The thickness of the 2 nd base layer 2 is preferably 10 to 100. Mu.m, more preferably 15 to 80mm, still more preferably 20 to 50. Mu.m.

By setting the thickness of the 2 nd base material layer 2 to the above lower limit value or more, the handling property can be well maintained while improving the rigidity while maintaining the following property of the release film 10. On the other hand, by setting the thickness of the 2 nd base material layer 2 to the above upper limit value or less, the flexibility of the release film 10 is improved, and the mold following property is easily obtained.

In the present embodiment, the 2 nd base layer 2 is a stretched or unstretched film made of a 2 nd resin composition containing a resin. The stretching or non-stretching can be appropriately set according to the combination with the release layer 1 and the 1 st base layer 3, but it is preferable to form a stretched film when the rigidity of the film is improved and an unstretched film when the moldability is improved.

The stretching can be produced by a known method such as sequential biaxial stretching, simultaneous biaxial stretching, and tubular stretching.

In the present embodiment, the 2 nd base material layer 2 contains 1 or 2 or more kinds of resins selected from polyester resins, polyolefin resins, and polyamide resins as resins. Among them, polyester resins and polyolefin resins are preferable.

(polyester resin)

Specific examples of the polyester resin include polyethylene terephthalate resin (PET), polybutylene terephthalate resin (PBT), polytrimethylene terephthalate resin (PTT), polyhexamethylene terephthalate (PHT), and polyethylene naphthalate resin (PEN). These may be used alone or in combination of 2 or more.

(polyolefin resin)

The polyolefin resin is a resin having a structural unit derived from an α -olefin such as ethylene, propylene, and butene, and a known resin can be used. Specific examples of the polyolefin resin include Polyethylene (PE) such as Low Density Polyethylene (LDPE), medium Density Polyethylene (MDPE), high Density Polyethylene (HDPE) and linear low density polyethylene (mLLPE); polypropylene (PP); polyvinyl alcohol (PVA); ethylene vinyl acetate copolymer (EVA); ethylene methyl acrylate copolymer (EMA); ethylene-acrylic acid copolymers (EAA); ethylene methyl methacrylate copolymer (EMMA); ethylene-ethyl acrylate copolymer (EEA); ethylene-methacrylic acid copolymers (EMAA); an ionomer resin; ethylene-vinyl alcohol copolymer (EVOH), cyclic olefin resin (COP), and the like. These may be used alone or in combination of 2 or more.

(Polyamide resin)

Examples of the polyamide resin include aliphatic polyamide and aromatic polyamide. Specific examples of the aliphatic polyamide include polyamide 6, polyamide 6-6,6 copolymer, polyamide 11, polyamide 12, and the like. Specific examples of the aromatic polyamide include polyamide 61, polyamide 66/6T, polyamide 6T/6 and polyamide 12/6T.

The 2 nd resin composition may further contain other components among the above components within a range that does not impair the characteristics of the release film 10. The other components are not limited, and the same components as those listed for the resin composition 1 can be used.

[ 1 st substrate layer 3]

In the present embodiment, the 1 st base material layer 3 is a resin layer located between the release layer 1 and the 2 nd base material layer 2 in the release film 10 having a multilayer structure.

In the present embodiment, the 1 st base material layer 3 imparts an appropriate stiffness to the release film 10, and can improve the handling properties while maintaining the following properties of the release film 10.

The thickness of the 1 st base material layer 3 is preferably appropriately adjusted according to the thickness of the 2 nd base material layer 2, and the total thickness of the 1 st base material layer 3 and the 2 nd base material layer 2 is preferably 25 to 70 μm, more preferably 30 to 50 μm.

By setting the total thickness of the 1 st base material layer 3 and the 2 nd base material layer 2 to the above lower limit value or more, the handling property can be well maintained while improving the rigidity while maintaining the following property of the release film 10. On the other hand, by setting the total thickness of the 1 st base material layer 3 and the 2 nd base material layer 2 to the above-described upper limit value or less, the flexibility of the release film 10 is improved, and the mold following property is easily obtained.

In the present embodiment, the 1 st base layer 3 is a stretched or unstretched film made of the 3 rd resin composition containing a resin. The stretching or non-stretching can be appropriately set according to the combination with the release layer 1 and the 2 nd base layer 2, but it is preferable to form a stretched film when the rigidity of the film is improved and to form a film when the moldability is improved.

As the 3 rd resin composition, the same composition as the components described in the 2 nd resin composition constituting the 2 nd base material layer 2 can be used.

The 3 rd resin composition may be the same as or different from the 2 nd resin composition.

In the present embodiment, the 1 st base material layer 3 contains 1 or 2 or more kinds selected from polyester resins, polyolefin resins, and polyamide resins. As these polyester resins, polyolefin resins, and polyamide resins, the same resins as those described in the 2 nd base layer 2 can be used.

Among them, the 1 st base material layer 3 is preferably a polyamide resin, more preferably a polyester resin.

Method for producing release film

Next, a method for manufacturing the release film 10 according to the present embodiment will be described.

The method for producing the release film 10 or the release layers 1, 1 st base material layer 3, and 2 nd base material layer 2 can be carried out by a known method, but can be produced by a known method such as a coextrusion method, an extrusion lamination method, a dry lamination method, a inflation method, an expansion extrusion method, or a T-die extrusion method.

Specifically, for example, (i) the 2 nd and 1 st base material layers 2 and 3 may be formed in a film form, the 2 nd and 1 st base material layers 2 and 3 may be laminated by lamination processing or the like, and then a coating liquid (varnish or paste) of the 1 st resin composition constituting the release layer 1 may be applied to the 1 st base material layer 3 and cured to form and laminate the release layer 1, and (ii) the release film 10 may be formed by laminating the 1 st and 2 nd base material layers 1 and 3 with the 1 st base material layer 3 interposed therebetween after the film-like release layer 1, 2 nd base material layer 2 are formed, and bonding the layers by lamination processing or the like or with an adhesive layer or the like. By adopting the manufacturing method (i), the thickness of the release layer 1 can be reduced more simply and stably. By adopting the production method (ii), the thickness of the release layer 1 can be increased more simply and stably.

When the release layer 1, the 2 nd base material layer 2, and the 1 st base material layer 3 are formed separately, a film can be obtained by a known method such as an extrusion molding method, a calender molding method, a press molding method, or a coating method. Further, the obtained films may be subjected to stretching treatment as needed.

In the case of using the above-mentioned coating method, for example, the 1 st resin composition constituting the release layer 1 is uniformly mixed by an arbitrary kneading apparatus to prepare a coating liquid (varnish or paste) and the coating liquid is applied to the 1 st base material layer 3, whereby a laminated structure of the 1 st base material layer 3 and the release layer 1 can be obtained.

The temperature at the time of kneading is appropriately set according to the type of resin, but for example, the roll setting temperature is preferably about 10 to 70 ℃, and more preferably about 25 to 30 ℃. The kneading time is, for example, preferably about 5 minutes to 1 hour, and more preferably about 10 minutes to 40 minutes. The kneading apparatus is not particularly limited, but, for example, a kneader, 2 rolls, a Banbury (Banbury) kneader (continuous kneader), a pressure kneader, or the like can be used.

Then, the obtained coating liquid is applied to the surface to be coated to form a coating film.

The coating method is not particularly limited, and is based on various known means. Examples thereof include roll coaters, reverse roll coaters, gravure coaters, knife coaters, bar coaters, and the like. In the case of forming a laminate structure while winding or feeding any one of the release layer 1, the 2 nd base material layer 2, and the 1 st base material layer 3 onto a roll by a roll-to-roll method, it is preferable to reduce the tension caused by winding or feeding as much as possible. And, the weight after curing is preferably 0.01 to 10g/m for the coating amount ² More preferably 0.05 to 5g/m ² 。

Thereafter, each of the coating films is cured to thereby obtain a desired film. As the curing conditions, for example, curing is carried out at 90 to 170℃for 30 seconds to 5 minutes.

Embodiment 2

The release film of embodiment 2 may have a single-layer structure, or may have a multilayer structure including a release layer serving as at least one surface of the release film, that is, a release surface, and a base layer made of a material different from the release layer. From the viewpoint of having both sufficient elongation and elastic recovery against elongation at a higher level, a multilayer structure is preferable. Hereinafter, a case where the release film has a multilayer structure will be described in detail as an example.

As shown in fig. 2, the release film 211 of the present embodiment includes a base material layer 202 and a release layer 201 laminated on the base material layer 202.

The release film 211 of the present embodiment satisfies the following (a) to (b).

(a) The release film 211 has a 5% tensile strength (5% modulus) of 1.0MPa or more and 5.0MPa or less at 180 ℃, (b) has a breaking strength of X1 (MPa) at 25 ℃, X2 (MPa) at 180 ℃, and (1- (X1-X2)/X1) of α1 of 0.20 or more and 0.80 or less.

This can obtain sufficient elongation and shape recovery property against elongation, and can effectively suppress occurrence of wrinkles and distortions on the release film 211. Although the details of the reason are not clear, the following is presumed.

First, it is presumed that, according to the index of (a), the performance of the release film 211 to return to the original shape with respect to elongation is easily controlled. Further, it is presumed that, according to the index of (b), the deformation easiness at the time of heating can be suitably obtained while maintaining the strength against deformation. Further, by simultaneously controlling the indices of (a) and (b), it is possible to achieve a balance between sufficient elongation and recovery from elongation at a high level, and as a result, it is considered that wrinkles and distortions that may occur when using a release film can be effectively suppressed.

In the above (a), the 5% tensile strength (5% modulus) at 180℃is 1.0MPa or more and 5.0MPa or less, preferably 1.0 to 4.0, more preferably 1.5 to 3.0.

In the above (b), α1 is 0.20 to 0.80, preferably 0.20 to 0.70, more preferably 0.20 to 0.50.

The release film 211 of the present embodiment further preferably satisfies the following (c).

(c) The Young's modulus of the release film 211 at 180℃is 25MPa or more and 110MPa or less, preferably 50 to 100MPa, and more preferably 50 to 80MPa.

By setting the young's modulus at 180 ℃ within the above numerical range, the mold-following property at the time of vacuum bonding can be improved to obtain an appropriate flexibility of the release film 211. In general, the mold in vacuum bonding is heated, and thus the follow-up property of the release film 211 is more appropriately controlled by controlling the young's modulus at 180 ℃.

The release film 211 of the present embodiment further preferably satisfies the following (d).

(d) The dimensional change rate of the release film 211 when the temperature is raised from 30 ℃ to 180 ℃ at 2 ℃/min is 4% or more and 40% or less, preferably 5 to 35%, more preferably 7 to 30%, by Thermal Mechanical Analysis (TMA) with a tensile load of 500 mN.

It is assumed that, when the dimensional change ratio is within the above-described numerical range, elongation and deformation against local stress are easily obtained, and therefore, when the lower die and the upper die are fitted, the release film 211 is easily locally elongated, and occurrence of wrinkles and distortions in the entire release film 211 is easily suppressed.

The indices (a) to (d) can be achieved by, for example, appropriately selecting and combining known methods such as the type and blending amount of the raw material of the release layer 201, the method of producing the raw material, and the method of producing the release film 211, and a method different from the conventional method is used.

Among these, for example, when a silicone resin is selected as a material of the release layer 201, the type, blending ratio, crosslinking density, crosslinking structure, and the like of the silicone resin are appropriately controlled, or the blending ratio of the inorganic filler, the dispersibility of the inorganic filler, and the like are improved, and are exemplified as elements for setting the above index within a desired numerical range.

Further, by adjusting the curing conditions, temperature, and time for obtaining the release layer 201, the crosslinking density, crosslinking structure, and the like of the resin can be appropriately controlled, and the above index can be set within a desired numerical range. In addition, for example, in the case of manufacturing a release film by sandwiching the release film between substrates, the surface roughness can be changed according to the surface state. In addition, it is effective to control the material combination of the release layer 201 and the base material layer 202.

The thickness of the release film 211 is preferably 5 μm or more and 150 μm or less, more preferably 10 μm or more and 100 μm or less, and still more preferably 15 μm or more and 80 μm or less.

The layers included in the release film 211 according to the present embodiment will be described below.

[ Release layer ]

The release layer 201 forms one surface of a release film 211 and has a release surface 203.

The thickness of the release layer 201 is preferably 0.1 μm or more and 150 μm or less, more preferably 1 μm or more and 100 μm or less, still more preferably 5 μm or more and 50 μm or less, still more preferably 30 μm or less.

When the thickness of the release layer 201 is equal to or greater than the lower limit, the rigidity of the release film 211 is improved, and occurrence of wrinkles due to excessive deformation is easily suppressed. As a result, mold following property and dimensional stability can be obtained. On the other hand, by controlling the rigidity of the release film 211 by setting the thickness of the release layer 201 to the above-described upper limit value or less, the balance between the mold following property and the release property can be improved.

The release surface 203 of the release layer 201 is a surface that contacts a sealing resin described later when the release film 211 is used. The surface roughness Rz of the release surface 203 is preferably 0.05 to 10 μm, more preferably 0.08 to 7 μm.

By setting the surface roughness Rz of the parting surface 203 to the above lower limit value or more, the balance between the parting property and the mold follow-up property at the time of molding can be improved. On the other hand, by setting the surface roughness Rz of the release surface 203 to the above-described upper limit value or less, the mold follow-up property and dimensional stability can be maintained and the releasability can be improved.

The method for controlling the surface roughness of the release surface 203 can be adjusted by a known method such as transferring an embossed pattern to a film using a roller subjected to embossing in the step of manufacturing the release film 211, or blending particles into the material of the release layer 201.

As for the surface roughness Rz of the release layer 201, according to JIS B0601: 2013.

The release layer 201 is composed of the 1 st resin composition containing a resin.

As the 1 st resin composition, the same composition as that described in embodiment 1 can be used.

[ method for producing Release layer ]

Next, a method for manufacturing the release layer 201 of the present embodiment will be described.

As a method for producing the release layer 201 of the present embodiment, the 1 st resin composition is prepared, and the 1 st resin composition is formed into a film shape and cured, whereby the release layer 201 can be obtained.

Hereinafter, details will be described.

First, the 1 st resin composition was prepared by uniformly mixing the components of the 1 st resin composition by an arbitrary kneading apparatus.

Hereinafter, a silicone resin is used as an example of the resin, and the details will be described.

[1] For example, the vinyl-containing organopolysiloxane (a), the inorganic filler, and the silane coupling agent are weighed in predetermined amounts, and then kneaded by an arbitrary kneading apparatus to obtain a kneaded product.

In addition, water may be added as needed to obtain the kneaded product. This ensures that the silane coupling agent reacts with the inorganic filler.

The kneading is preferably performed in step 1 by heating under the 1 st temperature condition and in step 2 by heating under the 2 nd temperature condition. Thus, in step 1, the surface of the inorganic filler can be treated with the coupling agent, and in step 2, by-products generated during the reaction between the inorganic filler and the coupling agent can be surely removed from the kneaded mixture. Thereafter, component (a) may be added to the obtained kneaded product as needed, and further kneading may be performed. This can improve the affinity of the components of the kneaded material.

The 1 st temperature is, for example, preferably about 40 to 120 ℃, and more preferably about 60 to 90 ℃. The 2 nd temperature is, for example, preferably about 130 to 210℃and more preferably about 160 to 180 ℃.

The environment in step 1 is preferably an inert environment such as a nitrogen environment, and the environment in step 2 is preferably a reduced pressure environment.

The time in step 1 is, for example, preferably about 0.3 to 1.5 hours, and more preferably about 0.5 to 1.2 hours. The time of the step 2 is, for example, preferably about 0.7 to 3.0 hours, more preferably about 1.0 to 2.0 hours.

The above-described effects can be obtained more remarkably by setting the conditions of the steps 1 and 2 as described above.

[2] Next, the organohydrogen polysiloxane (B) and the catalyst were weighed in predetermined amounts, and thereafter, the components were kneaded in the kneaded product prepared in the above-mentioned step [1] using an arbitrary kneading apparatus, whereby a 1 st resin composition was obtained. The 1 st resin composition obtained may be a paste containing a solvent.

In addition, when kneading the components (B) and the catalyst, it is preferable to knead the kneaded product prepared in the step [1] and the organohydrogen polysiloxane (B) in advance, knead the kneaded product prepared in the step [1] and the catalyst, and thereafter knead the kneaded products. Thus, the reaction between the vinyl-containing organopolysiloxane (a) and the organohydrogen polysiloxane (B) is not performed, and the components can be reliably dispersed in the 1 st resin composition.

The temperature at which the component (B) and the catalyst are kneaded is preferably about 10 to 70℃and more preferably about 25 to 30℃as the roll set temperature.

The kneading time is, for example, preferably about 5 minutes to 1 hour, and more preferably about 10 minutes to 40 minutes.

In the above-mentioned step [1] and the above-mentioned step [2], by setting the temperature within the above-mentioned range, the progress of the reaction of the vinyl-containing organopolysiloxane (A) with the organohydrogen polysiloxane (B) can be prevented or suppressed more surely. In the step [1] and the step [2], the kneading time is set within the above range, whereby the components can be more reliably dispersed in the 1 st resin composition.

The kneading apparatus used in each of steps [1] and [2] is not particularly limited, but, for example, a kneader, 2 rolls, a Banbury mixer (continuous kneader), a pressure kneader, or the like can be used.

In the step [2], a reaction inhibitor such as 1-ethynyl cyclohexanol may be added to the kneaded material. Thus, even if the temperature of the kneaded material is set to a relatively high temperature, the reaction between the vinyl-containing organopolysiloxane (a) and the organohydrogen polysiloxane (B) can be prevented or suppressed more reliably.

[3] Next, the 1 st resin composition obtained in the step [2] is dissolved in a solvent to form a paste.

[4] Next, the 1 st resin composition is processed into a film and cured to form the release layer 201.

Specifically, the 1 st resin composition is molded into a film by extrusion molding, calendaring, press molding, coating, or the like. In addition, transfer/embossing may be performed on the surface shape of a roll or the like at the time of film formation.

In this embodiment, for example, the curing step of the 1 st resin composition is performed by heating (1-time curing) at 100 to 250 ℃ for 1 to 30 minutes and then post-baking (2-time curing) at 100 to 250 ℃ for 1 to 4 hours.

Through the above-described steps, the release film 211 as the release layer 201 using the 1 st resin composition according to the present embodiment can be obtained.

[ substrate layer 202]

In the release film 211 of the present embodiment, the base material layer 202 may be used in order to exert shape stability, manufacturing stability, release function of the release layer, and the like of the release film 211, from the viewpoint of imparting appropriate rigidity.

The thickness of the base material layer 202 is preferably 5 μm or more and 50 μm or less, more preferably 9 μm or more and 35 μm or less, and still more preferably 12 μm or more and 25 μm or less.

When the thickness of the base material layer 202 is equal to or greater than the lower limit value, the rigidity of the release film 211 is improved, and occurrence of wrinkles due to excessive deformation is easily suppressed. As a result, mold following property and dimensional stability can be obtained. On the other hand, by controlling the rigidity of the release film 211 by setting the thickness of the base material layer 202 to the above-described upper limit value or less, the balance between mold following property and releasability can be improved.

The material of the base material layer 202 includes 1 or 2 or more kinds selected from polyester resins, polyamide resins, and polyolefin resins.

The polyester resin, polyamide resin, and polyolefin resin may be the same as those described for the release layer 201.

The base material layer 202 may be a stretched film, and may be manufactured by a known method such as sequential biaxial stretching, simultaneous biaxial stretching, and tubular stretching.

[ method for producing Release film ]

As a method for forming the release film 211, a known method such as a coextrusion method, an extrusion lamination method, a dry lamination method, or an inflation method can be used. The release layer 201 may be formed on the substrate layer 202 by coating the 1 st resin composition prepared in a paste form on the surface of the substrate layer 202.

In the release film 211, for example, the release layer 201 and the base material layer 202 may be manufactured separately and then bonded by a laminator or the like. The release layer 201 and the base layer 202 may be bonded directly or by an adhesive layer.

The method for producing the base material layer 202 is not limited, and specifically, an expansion extrusion method, a T-film extrusion method, and the like are mentioned.

Hereinafter, an example of the reference form of embodiment 2 is shown.

[1] A release film satisfying the following (a) to (b).

(a) The release film has a 5% tensile strength (5% modulus) at 180 ℃ of 1.0MPa or more and 5.0MPa or less,

[2] The release film according to [1], which satisfies the following (c).

(c) The Young's modulus of the release film at 180 ℃ is 25MPa or more and 110MPa or less.

[3] The release film according to [1] or [2], which satisfies the following (d).

(d) The release film has a dimensional change rate of 4% or more and 40% or less when the temperature is raised from 30 ℃ to 180 ℃ at 2 ℃/min, with a tensile load of 500mN by Thermal Mechanical Analysis (TMA).

[4] The release film according to any one of [1] to [3], wherein the release film has a multilayer structure including a release layer which becomes at least one face of the release film and a base material layer formed of a material different from the release layer.

[5] The release film according to any one of [1] to [4], wherein the release film is used for a use of being disposed between a mold and a semiconductor device in a molding process of resin-encapsulated semiconductor device in which the semiconductor device is resin-encapsulated.

Embodiment 3

The release film of embodiment 3 may have a single-layer structure, or may have a multilayer structure including a release layer serving as at least one surface of the release film, that is, a release surface, and a base layer made of a material different from the release layer. From the viewpoint of having both sufficient elongation and elastic recovery against elongation at a higher level, a multilayer structure is preferable. Hereinafter, a case where the release film has a multilayer structure will be described in detail as an example.

As shown in fig. 3, the release film 311 of the present embodiment includes a base material layer 302 and a release layer 301 laminated on the base material layer 302.

In the release film 311 of the present embodiment, the following (a) is satisfied in a TMA curve obtained from a relationship between a measured temperature and a dimensional change amount of a length of the release film obtained by stretching the release film under conditions that a temperature rise rate is 2 ℃/min and a load is 500mN in a thermo-mechanical analysis (TMA) measurement.

Alternatively, in the release film 311 of the present embodiment, the following (b) is satisfied in a TMA curve obtained from a relationship between a measured temperature and a dimensional change amount of a length of the release film obtained by stretching the release film under conditions that a temperature rise rate is 2 ℃/min and a load is 500mN in a thermo-mechanical analysis (TMA) measurement.

This can obtain sufficient elongation and shape recovery property against elongation, and can effectively suppress occurrence of wrinkles and distortions on the release film 311. Although the details of the reason are not clear, the following is presumed.

It is assumed that, according to the index of (a), the rapid dimensional change of the release film 311 when the mold is heated is suppressed, whereby appropriate strength can be maintained, and dimensional stability and shape recovery can be obtained, and therefore wrinkles and distortions are less likely to occur in the release film 311.

Further, according to the index of (b), it is considered that the balance between the amount of dimensional change of the release film 311 from the room temperature state before the use of the release film 311 to the state in which the release film 311 is placed on the mold and heated and the amount of dimensional change of the release film 311 when the mold is heated can be controlled, whereby the balance between sufficient elongation and recovery from elongation can be achieved at a high level, and as a result, wrinkles and distortions that may occur when the release film is used can be effectively suppressed.

In the above (a), α1 is 0.1 to 1.0, preferably 0.2 to 0.9, and more preferably 0.3 to 0.7.

In the above (b), α1/α2 is 6 to 35, preferably 8 to 30, more preferably 10 to 28.

In the present embodiment, for the measurement of the thermo-mechanical analysis (TMA), a commercially available thermo-mechanical analysis device (for example, TMA7100 (manufactured by Hitachi High-Tech Science Corporation) or the like) can be used, and the measurement can be performed under the following measurement conditions.

(measurement conditions)

Temperature range: 0-250 ℃.

Heating rate: 2 ℃/min.

Load: 500mN.

Test piece: 4mm wide by 10mm.

Test mode: and (5) compressing.

The elongation at break of the release film 311 of the present embodiment is preferably 100% or more and 850% or less, and more preferably 100 to 300% at 80 ℃.

By setting the elongation at break to the above lower limit value or more, the elastic modulus can be flexibly elongated with respect to tension, and by setting the elongation at break to the above upper limit value or less, the shape recovery property with respect to elongation can be obtained.

The indices and elongation at break of (a) to (b) in embodiment 3 can be achieved by, for example, appropriately selecting and combining known methods such as the types and blending amounts of the materials of the release layer 301, the method of producing the materials, and the method of producing the release film 311, by using methods different from conventional methods.

Among these, for example, when a silicone resin is selected as a material of the release layer 301, the type, blending ratio, crosslinking density, crosslinking structure, and the like of the silicone resin are appropriately controlled, or the blending ratio of the inorganic filler, the dispersibility of the inorganic filler, and the like are improved, and are exemplified as elements for setting the above index within a desired numerical range.

Further, by adjusting the curing conditions, temperature, and time for obtaining the release layer 301, the crosslinking density, crosslinking structure, and the like of the resin can be appropriately controlled, and the above index can be set within a desired numerical range. In addition, for example, in the case of manufacturing the release film 311 by sandwiching it between substrates, the surface roughness can be changed according to the surface state. In addition, it is effective to control the material combination of the release layer 301 and the base material layer 302.

The thickness of the release film 311 is preferably 5 μm or more and 150 μm or less, more preferably 10 μm or more and 100 μm or less, and still more preferably 15 μm or more and 80 μm or less.

The layers included in the release film 311 of the present embodiment will be described below.

[ Release layer ]

The release layer 301 forms one surface of the release film 311 and has a release surface 303.

The thickness of the release layer 301 is preferably 0.1 μm or more and 150 μm or less, more preferably 1 μm or more and 100 μm or less, still more preferably 5 μm or more and 50 μm or less, still more preferably 30 μm or less.

When the thickness of the release layer 301 is equal to or greater than the lower limit, the rigidity of the release film 311 is improved, and occurrence of wrinkles due to excessive deformation is easily suppressed. As a result, mold following property and dimensional stability can be obtained. On the other hand, by controlling the rigidity of the release film 311 by setting the thickness of the release layer 301 to the above-described upper limit value or less, the balance between mold following property and releasability can be improved.

The release surface 303 of the release layer 301 is a surface that contacts a sealing resin described later when the release film 311 is used. The surface roughness Rz of the release surface 303 is preferably 0.05 to 10 μm, more preferably 0.08 to 7 μm.

By setting the surface roughness Rz of the parting surface 303 to the above lower limit value or more, the balance between the parting property and the mold follow-up property at the time of molding can be improved. On the other hand, by setting the surface roughness Rz of the parting surface 303 to the above upper limit value or less, the mold follow-up property and dimensional stability can be maintained and the parting property can be improved.

The method for controlling the surface roughness of the release surface 303 can be adjusted by a known method such as transferring an embossed pattern to the film using a roller subjected to embossing in the step of manufacturing the release film 211, or blending particles into the material of the release layer 301.

For the surface roughness Rz of the release layer 301, according to JIS B0601: 2013.

The release layer 301 is composed of the 1 st resin composition containing a resin.

[ method for producing Release layer ]

Next, the method for manufacturing the release layer 301 according to the present embodiment can be performed in the same manner as the method for manufacturing the release layer 201 according to embodiment 2 described above.

[ substrate layer 302]

In the release film 311 of the present embodiment, the base material layer 302 may be used in order to provide appropriate rigidity in order to exhibit the shape stability, manufacturing stability, release function of the release film 311, and the like.

The thickness of the base material layer 302 is preferably 5 μm or more and 50 μm or less, more preferably 9 μm or more and 35 μm or less, and still more preferably 12 μm or more and 25 μm or less.

When the thickness of the base material layer 302 is equal to or greater than the lower limit value, the rigidity of the release film 311 is improved, and occurrence of wrinkles due to excessive deformation is easily suppressed. As a result, mold following property and dimensional stability can be obtained. On the other hand, by controlling the rigidity of the release film 311 by setting the thickness of the base material layer 302 to the above-described upper limit value or less, the balance between mold following property and releasability can be improved.

The material of the base layer 302 may be 1 or 2 or more kinds selected from polyester resins, polyamide resins, and polyolefin resins.

The polyester resin, polyamide resin, and polyolefin resin may be the same as those described for the release layer 301.

The base layer 302 may be a stretched film, and may be manufactured by a known method such as sequential biaxial stretching, simultaneous biaxial stretching, and tubular stretching.

[ method for producing Release film ]

As a method for producing the release film 311, the same method as described in the method for producing a release film of embodiment 2 above can be used.

Hereinafter, an example of the reference form of embodiment 3 is shown.

[1] In a release film, the following (a) is satisfied in a TMA curve obtained from a relationship between a temperature measured by stretching the release film at a heating rate of 2 ℃/min and a load of 500mN in a Thermal Mechanical Analysis (TMA) measurement and a dimensional change amount of a length of the release film.

[2] In a release film, the following (b) is satisfied in a TMA curve obtained from a relationship between a temperature measured by stretching the release film at a heating rate of 2 ℃/min and a load of 500mN in a Thermal Mechanical Analysis (TMA) measurement and a dimensional change amount of a length of the release film.

[3] The release film according to [1] or [2], wherein the elongation at break at 180℃is 100% or more and 850% or less.

[5] The release film according to any one of [1] to [4], wherein the release film is provided for use in a packaging resin molding process of a resin-packaged semiconductor device in which a semiconductor device is resin-packaged, and is disposed between a mold and the semiconductor device.

Use of release film

The release film 10 according to embodiment 1, the release film 211 according to embodiment 2, and the release film 311 according to embodiment 3 are used for the following purposes: in the resin packaging step of the semiconductor device, the semiconductor device is arranged between a mold to which packaging resin is supplied and the semiconductor device packaged with the resin. That is, the mold release film may be a so-called mold release film, or may be used for other purposes. As other applications, for example, the following applications are given: when a flexible printed circuit board (hereinafter, also referred to as "FPC") is manufactured by bonding a cover film (hereinafter, also referred to as "CL film") to a flexible film (hereinafter, also referred to as "circuit exposure film") having a circuit exposed thereto by heating and pressing with an adhesive, the cover film is disposed between the cover film and a mold. For example, the resin composition can be used as a release film for curing a prepreg of a thermosetting resin such as CFRP, a release film for molding a thermosetting resin, a transfer release film for decoration such as printing a product having a three-dimensional shape, or the like.

Hereinafter, an example of a method for manufacturing a resin-encapsulated semiconductor device using the release film 10 will be described with reference to the release film 10.

The method for manufacturing the resin-encapsulated semiconductor device includes the following steps.

(step 1) preparation step of the semiconductor device.

(step 2) a release film setting step.

(step 3) a step of supplying a sealing resin.

(step 4) curing step.

(step 5) a step of releasing the molded article.

Details of each step will be described below.

(step 1) preparation step of semiconductor device

The semiconductor device is a device that electrically connects an electrode pad provided on a circuit wiring on a support body and an electrode provided on a semiconductor element.

Examples of the semiconductor element include a light emitting element, a light receiving element, and the like. The light emitting element may be an LED chip (light emitting diode), and the light receiving element may be an image sensor.

The support is a substrate formed in any shape such as a circle or a polygon. Examples of the support include a ceramic substrate, a silicone substrate, a metal substrate, a rigid substrate such as an epoxy resin and a BT resin, and a flexible substrate such as a polyimide resin and a polyethylene substrate.

(step 2) step of setting Release film

The mold release film 10 is disposed on a lower mold having a cavity recess for supplying the encapsulating resin. At this time, the release surface 3 of the release film 10 is arranged on the front side, that is, in contact with the sealing resin supplied later.

The release film 10 is disposed along the surfaces of the flat portions in and surrounding the cavity recess of the lower mold. At this time, a suction port for making the release film 10 follow the shape of the cavity concave portion of the lower mold is provided at the planar portion surrounding the cavity concave portion. The vacuum suction is performed by sucking and discharging air, moisture, gas, and the like existing in the space between the release film 10 and the mold from the suction port using a suction device or the like. In order to firmly fix the release film 10 to the mold, the release film 10 may be held by a suction cup mechanism disposed at a position corresponding to the outer peripheral portion of the encapsulating resin injection region, the outer peripheral portion of the entire release film 10, or the outer peripheral portion of the entire mold.

As the mold, a known mold and a resin mold can be exemplified.

(step 3) step of supplying the sealing resin

Next, the encapsulating resin is supplied to the concave portion of the mold and the region where the release film 10 is arranged. The method of supplying can be a known method. The encapsulating resin may be any known resin, but examples thereof include 1 or a mixture of these resins, such as silicone resin, epoxy resin, acrylic resin, fluorine resin, polyimide resin, and silicone-modified epoxy resin, and a precursor of these resins.

In the present embodiment, when the release film 10 is applied to a compression molding method (compression molding method), the shape of the encapsulating resin is preferably a shape processed into an ingot, pellet, sealed pellet, or sheet.

In the mold, the encapsulating resin is heated to a predetermined temperature to be in a flowing state.

(step 4) curing step

Next, a semiconductor device to be a molding object is mounted on an upper die provided with a protruding holder for holding the outer edge of the molding object so as to prevent the molding object from falling, and the surface of the semiconductor device on which the semiconductor element is provided is opposed to the lower die, and the die in which the encapsulating resin is supplied to the recess is pressure-bonded. At this time, the fixture of the upper die is fitted into the groove of the lower die, and the semiconductor element is covered with the encapsulating resin. Then, the encapsulating resin is heated and pressurized, and thereby cured to obtain a molded article.

In the case where the encapsulating resin is a precursor of the curable resin, the curable resin may be cured by heating and irradiation with active energy rays. Examples of the active energy rays include radiation, ultraviolet rays, visible rays, and electron rays.

(step 5) demolding step of molded article

Thereafter, the molded article is removed from the mold. In the mold release step of the molded article, air, moisture, gas, or the like is supplied between the mold release film 10 and the mold, whereby the mold release film 10 is peeled off from the mold and the molded article is released. Simultaneously with or after this, the release film 10 is released from the molded body.

When 1 semiconductor element is provided on the support, the molded body becomes a resin-encapsulated semiconductor device.

Thus, a semiconductor device having a good appearance can be obtained.

The embodiments of the present invention have been described above, but these are examples of the present invention, and various configurations other than the above can be used. The present invention is not limited to the above-described embodiments, and modifications, improvements, and the like within a range that can achieve the object of the present invention are included in the present invention.

Examples

The present invention will be described in detail with reference to examples, but the present invention is not limited to the description of these examples.

Experiment 1

(1) Preparation of the 1 st resin composition

The following raw materials were used to prepare a1 st resin composition.

(vinyl-containing organopolysiloxane (A))

Linear organopolysiloxane (A1-1) having a low vinyl content: vinyl-containing dimethylpolysiloxane synthesized by the synthesis scheme 1 (R alone in the structure represented by the above formula (1-1) ¹ A structure having a vinyl group at the (terminal).

Linear organopolysiloxane (A1-2) having a high vinyl content: vinyl-containing dimethylpolysiloxane synthesized by the synthesis scheme 2 (R in the structure represented by the above formula (1-1)) ¹ R is R ² A vinyl structure).

(organohydrogen polysiloxane (B))

Manufactured by maitui advanced materials company (Momentive Performance Materials inc.): "TC-25D".

(inorganic filler)

Inorganic filler (C): silica fine particles (particle diameter: 7nm, specific surface area: 300m ² /g), manufactured by NIPPON AEROSIL co., ltd., "AEROSIL300".

(silane coupling agent)

Silane coupling agent (D-1): HEXAMETHYLDISILAZANE (HMDZ), manufactured by guerst corporation (Gelest), "HEXAMETHYLDISILAZANE (SIH 6110.1)".

Silane coupling agent (D-2): divinyltetramethyldisilazane, "1, 3-DIVINYLTETRAMETHYLISILAZANE (SID 4612.0)" manufactured by Gelst, inc.

(platinum or platinum Compound (E))

Manufactured by maitui advanced materials company (Momentive Performance Materials inc.): "TC-25A".

(Synthesis of vinyl-containing organopolysiloxane (A))

[ Synthesis scheme 1: synthesis of Linear organopolysiloxane (A1-1) having Low vinyl content

According to the following formula (5), a linear organopolysiloxane (A1-1) having a low vinyl content is synthesized.

That is, in a 300mL separable flask equipped with a cooling tube and stirring vanes, 74.7g (252 mmol) of octamethyl cyclotetrasiloxane and 0.1g of potassium silicate were placed in Ar gas substitution, and the temperature was raised, followed by stirring at 120℃for 30 minutes. In this case, the viscosity was found to increase.

Thereafter, the temperature was raised to 155℃and stirring was continued for 3 hours. After 3 hours, 0.1g (0.6 mmol) of 1, 3-divinyl tetramethyl disiloxane was added thereto, and the mixture was stirred at 155℃for 4 hours.

Further, after 4 hours, the mixture was diluted with 250mL of toluene and washed 3 times with water. The organic layer after washing was washed several times with 1.5L of methanol to conduct reprecipitation purification, whereby the oligomer and the polymer were separated. The obtained polymer was dried under reduced pressure at 60℃overnight to obtain a linear organopolysiloxane (A1-1) having a low vinyl content (Mn=2.2X10) ⁵ ，Mw＝4.8×10 ⁵ ). The vinyl content was 0.04 mol% as measured by H-NMR spectroscopy.

[ Synthesis scheme 2: synthesis of Linear organopolysiloxane (A1-2) having high vinyl content

In the synthesis step of (A1-1), a linear organopolysiloxane (A1-2) having a high vinyl content was synthesized in the same manner as in the synthesis step of (A1-1) except that 0.86g (2.5 mmol) of 2,4,6, 8-tetramethyl-2, 4,6, 8-tetravinyl-cyclotetrasiloxane was used in addition to 74.7g (252 mmol) of octamethyl-cyclotetrasiloxane, as in the following formula (6). (mn=2.3×10 ⁵ ，Mw＝5.0×10 ⁵ ). The vinyl content was 0.92 mol% as measured by H-NMR spectroscopy.

Next, a mixture of a vinyl group-containing organopolysiloxane (a), a silane coupling agent, and water (F) was kneaded in advance at a ratio shown in table 1 below, and thereafter, an inorganic filler was added to the mixture to further carry out kneading, thereby obtaining a kneaded product (silicone rubber compound).

Here, the kneading after the addition of the inorganic filler is performed through the 1 st step of kneading for 1 hour under a nitrogen atmosphere at 60 to 90 ℃ for the coupling reaction and the 2 nd step of kneading for 2 hours under a reduced pressure atmosphere at 160 to 180 ℃ for the removal of by-product (ammonia), and thereafter, cooling is performed, and the remaining 10% of the vinyl-containing organopolysiloxane (a) is added in 2 portions and kneaded for 20 minutes.

Next, to 100 parts by weight of the obtained kneaded material (silicone rubber compound) were added organohydrogen polysiloxane (B) (TC-25D) and platinum or platinum compound (E) (TC-25A) in the proportions shown in Table 1 below, and the mixture was kneaded with rolls to obtain 1 st resin compositions.

TABLE 1

(2) Preparation of Release film

In the following manner, release films of examples and comparative examples of experiment 1 were produced.

Example 1 >

As shown in Table 2, biaxially stretched polybutylene terephthalate (OPBT: manufactured by TOYOBO CO., ltd.) having a thickness of 15 μm, ESTEL (registered trademark) film manufactured by TOYOBO CO., ltd.) was used as the 1 st base material layer, polybutylene terephthalate film (CPBT: manufactured by Okura Industrial Co., ltd.) having a thickness of 25 μm, ESRM) was used as the 2 nd base material layer, and the 1 st base material layer and the 2 nd base material layer were laminated using a laminating adhesive (TM 593 (main agent), CAT-10L (curing agent), manufactured by TOYO-Morton, ltd. (solid content: 25 mass%, solvent: ethyl acetate)), and the like. Then, the prepared melamine-based release agent (melamine: manufactured by the chemical industry company, described as being barren, ltd., arakawa Chemical Industries, ltd.) (solid content: 10 mass% solvent: IPA) was applied onto the 1 st base layer using a bar coater, and cured for 1 minute at 120 ℃ C., thereby obtaining a release film having a release layer on the 1 st base layer. The thickness of the release layer of the obtained release film was 40. Mu.m, and the surface roughness Ra of the release surface of the release layer was 0.12. Mu.m.

Example 2 >

As shown in table 2, a release film was produced in the same manner as in example 1 except that the melamine release agent was changed to an acrylic release agent (acrylic acid: manufactured by feature corporation (tokusiki co., ltd)) (solid component amount 10% by mass, solvent: ethyl acetate), as a release layer. In addition, the drying conditions were set at 80℃for 3 minutes/at 40℃for 3 days.

Example 3 >

As shown in table 2, a melamine-based release agent was changed to a paste (the solid content was 25 mass% and decane solvent) formed from the 1 st resin composition prepared in the above (2) as a release layer, and a laminate film was obtained. A release film was produced in the same manner as in example 1, except that the surface of the release layer was subjected to the embossing process by sandwiching between a roll and a matte film when the obtained laminated film was wound with the roll. In addition, the release layer was cured at 180℃for 120 minutes.

Example 4 >

A release film was produced in the same manner as in example 3 except that the surface roughness of the matting film was changed as shown in table 2.

Example 5 >

A release film was produced in the same manner as in example 1 except that the 2 nd base layer was changed to a polybutylene terephthalate film (CPBT: manufactured by Okura Industrial co., ltd.) having a thickness of 35 μm as shown in table 2.

Example 6 >

A release film was produced in the same manner as in example 1 except that a polybutylene terephthalate film (CPBT: manufactured by large-warehouse Industrial co., ltd.) having a thickness of 25 μm was changed to the 1 st base layer, and a biaxially stretched polybutylene terephthalate film (OPBT: manufactured by eastern spinning corporation (TOYOBO co., ltd.) having a thickness of 15 μm was changed to the 2 nd base layer, DE 048).

Example 7 >

A release film was produced in the same manner as in example 1 except that biaxially stretched polyethylene terephthalate (OPET 1: manufactured by eastern spinning film solution company (TOYOBO FILM SOLUTIONS ltd.) was changed to the 1 st base layer and polybutylene terephthalate film (CPBT: manufactured by Okura industrial co., ltd.) was changed to the 2 nd base layer, as shown in table 2, the thickness of the polybutylene terephthalate film (CPBT: manufactured by Okura industrial co., ltd.) was changed to the 1 st base layer.

Example 8 >

As shown in table 2, a release film was produced in the same manner as in example 1 except that a biaxially stretched polypropylene film (OPP: manufactured by dori corporation (tolay INDUSTRIES, INC.), tolayfan (registered trademark) film # 40-2500) was changed to the 1 st base layer, and a biaxially stretched polybutylene terephthalate (OPBT: manufactured by TOYOBO co., ltd.) having a thickness of 15 μm, an eastern spinning ESTEL (registered trademark) film, DE 048) was changed to the 2 nd base layer.

Example 9 >

As shown in table 2, a release film was produced in the same manner as in example 1 except that a biaxially stretched nylon film (ONy: you Niji available from UNITIKA ltd.) having a thickness of 15 μm was changed to the 1 st base layer, and a biaxially stretched polybutylene terephthalate (OPBT: eastern spinning corporation (TOYOBO co., ltd.) having a thickness of 15 μm was changed to the 2 nd base layer, DE 048).

Example 10 >

As shown in table 2, a release film was produced in the same manner as in example 1 except that a nylon film (CNy: manufactured by the division of the company, ube Industries, ltd.) having a thickness of 25 μm was changed to the 1 st base layer, and a biaxially stretched polybutylene terephthalate (OPBT: manufactured by the division of the company, TOYOBO co., ltd.) having a thickness of 15 μm, an eastern spun ESTEL (registered trademark) film, DE 048) was changed to the 2 nd base layer.

Comparative example 1 >

As shown in table 2, a release film was produced in the same manner as in example 1 except that the substrate layer was changed to only the 1 st substrate layer of biaxially stretched polybutylene terephthalate (OPBT: manufactured by TOYOBO co., ltd.) of eastern spinning ESTEL (registered trademark) film, DE 048) having a thickness of 15 μm.

Comparative example 2 >

As shown in table 2, a release film was produced in the same manner as in example 1 except that the substrate layer was changed to only the 1 st substrate layer of biaxially stretched polybutylene terephthalate (OPBT: manufactured by TOYOBO co., ltd.) of eastern spinning ESTEL (registered trademark) film, DE 048) having a thickness of 20 μm.

Comparative example 3 >

As shown in table 2, a release film was produced in the same manner as in example 1 except that the substrate layer was changed to only the 1 st substrate layer of biaxially stretched polyethylene terephthalate (OPET 2: manufactured by TOYOBO co., ltd.) of eastern spinning ESTEL (registered trademark) film E5100) having a thickness of 50 μm.

(3) Measurement of physical Properties of Release film

Using the obtained release film, the following measurement/evaluation was performed. The results are shown in Table 2.

(a) Surface roughness Ra of the surface of the release film on the release layer side.

According to JIS B0601: 2013.

(b) Values measured by the ring stiffness test.

Ring stiffness tester (TOYO SEIKI co., ltd.) was used to measure the dimensions of the test pieces: 25mm×110mm (flow direction in producing a release film), ring length: 62mm, press-in amount: the rigidity strength was measured with the lapse of time under the condition of 5mm, and the maximum value during this period was set as "value measured by the ring rigidity test" (mN/cm).

(c) The tensile load was set to 500mN by Thermal Mechanical Analysis (TMA), and the dimensional change rate (%) at 180℃was increased from 30℃to 180℃at 2℃per minute.

Measurements were performed using TMA7100 (manufactured by Hitachi High-Tech Science Corporation).

(d) The storage modulus (MPa) at 180℃in the case of dynamic viscoelasticity (DMA) measurement was carried out at a heating rate of 5℃per minute and a frequency of 1 Hz.

According to JIS K7244: 1998.

(4) Production of molded article

The obtained release film was used for resin encapsulation, whereby a molded article was obtained.

First, as a resin for encapsulation, the following granular thermosetting resin composition was produced.

(raw materials)

Epoxy resin 1: biphenyl aralkyl type epoxy resin (manufactured by Nippon kayaku co., ltd., NC-3000).

Epoxy resin 2: biphenyl epoxy resin (YL 6677, manufactured by mitsubishi chemical Co., ltd.).

Curing agent 1: phenol aralkyl resins containing a biphenylene skeleton (manufactured by Nippon Kayaku co., ltd., GPH-65).

Curing agent 2: triphenylmethane type phenolic resins (AIR WATER inc.) modified with formaldehyde, HE 910-20.

Curing accelerator: triphenylphosphine (TPP) manufactured by north chemical industry company (HOKKO CHEMICAL INDUSTRY co., ltd.).

Inorganic filler: fused spherical silica (FB-950 FC manufactured by Denka Company Limited).

Coloring agent: carbon black (MA-600 manufactured by Mitsubishi chemical corporation).

Coupling agent: n-phenyl-gamma-aminopropyl trimethoxysilane (KBM-573, manufactured by Xinyue chemical Co., ltd.).

And (3) a release agent: carnauba wax (Nikko Fine products co., ltd.) manufactured by Nikko Carnauba.

(step)

4.5 parts by mass of the above-mentioned epoxy resin 1, 4.5 parts by mass of the epoxy resin 2, 2.8 parts by mass of the curing agent 1, 2.8 parts by mass of the curing agent 2, 0.4 part by mass of the curing accelerator, 84.2 parts by mass of the inorganic filler, 0.2 part by mass of the colorant, 0.4 part by mass of the coupling agent, and 0.2 part by mass of the release agent were prepared. Next, after mixing the raw material components using a kneader at normal temperature, roll kneading was performed while heating with 2 rolls at 45 ℃ and 90 ℃, thereby obtaining a kneaded product. Next, the kneaded material was cooled and then pulverized, whereby a granular thermosetting resin composition was obtained.

Next, curing (resin encapsulation) of the thermosetting resin composition was performed using each release film in the following steps, thereby obtaining a molded body.

(step)

First, 5 silver pastes were used to bond square semiconductor elements having a thickness of 0.3mm and 7.5mm to an organic substrate having a thickness of 0.4mm, a width of 65mm and a length of 190mm, and gold wires having a diameter of 18 μm and a length of 7mm were bonded at intervals of 60 μm. Then, the mold temperature of the compression molding machine (manufactured by TOWA Corporation, PMC 1040) was set to 175 ℃. Next, the organic substrate is fixed to the upper die so that the surface on which the semiconductor element is mounted faces the lower die. Next, after the release film was placed on the lower die so that the 2 nd base material layer side of the release film produced in each of examples and comparative examples was the lower die side, the internal space of the die was evacuated, thereby making the release film follow the lower die. Thereafter, the prepared granular thermosetting resin composition (encapsulating resin composition) was uniformly supplied onto the release film. Next, after the encapsulating resin composition was supplied, the mold was closed to a position where the distance between the organic substrate and the release film was 4mm, the pressure in the cavity formed by the lower mold and the upper mold was reduced to a reduced pressure of 0.8Torr over 4 seconds, and then the mold was completely closed over 12 seconds while continuing to reduce the pressure, and then encapsulation was performed under conditions of a molding pressure of 3.9MPa and a curing time of 90 seconds, whereby a molded article (cured product) was obtained.

(5) Evaluation of Release film

The following evaluations were performed for each release film. The results are shown in Table 2.

[ mold following Property ]

In the above steps, the degree of air pocket between the mold and the release film when the release film was caused to follow the mold by evacuation was evaluated according to the following criteria.

And (3) the following materials: no air pockets were created.

And (2) the following steps: although there is a minute air pocket, there is no problem in practical use.

Delta: with a tiny air pocket, the vacuum level of the film adsorption is reduced.

X: the air pocket is large and causes a defective following (or failure to evaluate).

[ dimensional stability ]

In the above steps, the appearance state (wrinkles and the like) of the cured product after releasing the cured product from the release film after molding was evaluated according to the following criteria.

And (2) the following steps: no wrinkles, distortion and no problems.

Delta: although there are some wrinkles, there is no problem in practical use.

X: large wrinkles and poor molding were generated.

[ mold releasability ]

In the above steps, the cured product was evaluated according to the following criteria based on the release behavior (offset, deflection, etc.) when releasing the cured product from the molded release film.

And (2) the following steps: there was no problem in releasability and molded article.

Delta: the molded article is deflected or bent at the time of releasing the mold, but there is no problem in practical use.

X: the molded article cannot be released from the mold or is greatly deflected.

[ operability ]

In the above steps, the state of the release film when the film was placed in a molding machine was evaluated according to the following criteria.

And (2) the following steps: no wrinkles, folds and no problems of the film were observed during the treatment.

Delta: film deflection and the like occur during handling, but there is no problem in practical use.

X: deformation due to wrinkles and folds of the film occurs during the treatment.

Experiment 2

(1) Raw materials

The raw material components used in examples and comparative examples shown in table 3 are shown below.

(vinyl-containing organopolysiloxane (A))

Linear organopolysiloxane (A1-1) having a low vinyl content: vinyl-containing dimethylpolysiloxane synthesized by the synthesis scheme 1 (R alone in the structure represented by the formula (1-1)) ¹ A structure having a vinyl group at the (terminal).

Linear organopolysiloxane (A1-2) having a high vinyl content: vinyl-containing dimethylpolysiloxane synthesized by the synthesis scheme 2 (R in the structure represented by the formula (1-1)) ¹ R is R ² A vinyl structure).

(organohydrogen polysiloxane (B))

(inorganic filler)

(silane coupling agent)

(platinum or platinum Compound (E))

(Synthesis of vinyl-containing organopolysiloxane (A))

According to the above formula (5) of experiment 1, a linear organopolysiloxane (A1-1) having a low vinyl content was synthesized.

In the synthesis step of (A1-1), a linear organopolysiloxane (A1-2) having a high vinyl content was synthesized as in the formula (6) of the experiment 1 except that 0.86g (2.5 mmol) of 2,4,6, 8-tetramethyl-2, 4,6, 8-tetravinyl-cyclotetrasiloxane was used in addition to 74.7g (252 mmol) of octamethyl-cyclotetrasiloxane in the same manner as in the synthesis step of (A1-1). (mn=2.3×10 ⁵ ，Mw＝5.0×10 ⁵ ). The vinyl content was 0.92 mol% as measured by H-NMR spectroscopy.

(2) Preparation of the 1 st resin composition (preparation of mold Release layer)

Each of the 1 st resin compositions was prepared in the following manner.

First, a mixture of a vinyl group-containing organopolysiloxane (a), a silane coupling agent, and water (F) was kneaded in advance at a ratio shown in table 3 below, and thereafter, an inorganic filler was added to the mixture to further knead the mixture, thereby obtaining a kneaded product (silicone rubber compound).

Next, to 100 parts by weight of the obtained kneaded material (silicone rubber compound) were added organohydrogen polysiloxane (B) (TC-25D) and platinum or platinum compound (E) (TC-25A) in the proportions shown in Table 3 below, and the mixture was kneaded with rolls to obtain 1 st resin compositions.

TABLE 3

(3) Preparation of release film comprising base layer

In the following manner, release films of examples and comparative examples of experiment 2 were produced.

Example 1 >

As shown in Table 4, biaxially stretched polybutylene terephthalate (OPBT 1: manufactured by TOYOBO CO., ltd.) having a thickness of 15 μm was used as a base layer, an ESTEL (registered trademark) film of Toyobo Co., DE 048) was coated with a paste (solid content 25% by mass, decane solvent) formed from the 1 st resin composition prepared in the above (2) on the base layer using a bar coater, and cured at 180℃for 120 minutes to obtain a release film having a release layer on the base layer. The thickness of the release layer of the obtained release film was 35. Mu.m, and the surface roughness Rz of the release surface of the release layer was 0.1. Mu.m.

Example 2 >

As shown in table 4, a release film was produced in the same manner as in example 1 except that the surface of the release layer was roughened by sandwiching a matte film in the film-forming step using the paste formed from the 1 st resin composition.

Example 3 >

A release film was produced in the same manner as in example 1 except that the thickness of the release layer was changed to 10 μm as shown in table 4.

Example 4 >

A release film was produced in the same manner as in example 1 except that the thickness of the release layer was changed to 70 μm as shown in table 4.

Example 5 >

A release film was produced in the same manner as in example 1 except that the 1 st resin composition for forming the release layer was changed to the composition shown in table 2 as shown in table 4.

Example 6 >

As shown in table 4, a release Film was produced in the same manner as in example 1 except that the base layer was changed to biaxially stretched polybutylene terephthalate (OPET 2: manufactured by KOHJIN Film & Chemicals co., ltd.) having a thickness of 20 μm, and the release layer was changed to be 30 μm.

Example 7 >

As shown in table 4, a release film was produced in the same manner as in example 1 except that the base layer was changed to a biaxially stretched polyethylene terephthalate (OPET 1: manufactured by TOYOBO co., ltd.) and the thickness of the release layer was changed to 41 μm.

Example 8 >

As shown in table 4, a release film was produced in the same manner as in example 1 except that the base layer was changed to a biaxially stretched polyethylene terephthalate (manufactured by TOYOBO co., ltd.) having a thickness of 12 μm, and the release layer was changed to a thickness of 38 μm.

Example 9 >

As shown in table 4, a release film was produced in the same manner as in example 1 except that the base layer was changed to biaxially stretched polyethylene terephthalate (OPET 2: manufactured by eastern spin film solution company (TOYOBO FILM SOLUTIONS ltd.) and the release layer was changed to 37 μm in thickness.

Comparative example 1 >

Comparative example 2 >

As shown in table 4, a release film was produced in the same manner as in example 1 except that the base layer was changed to a biaxially stretched polyethylene terephthalate (OPET 1: manufactured by TOYOBO co., ltd.) and the thickness of the release layer was changed to 31 μm.

Comparative example 3 >

As shown in table 4, a release film was produced in the same manner as in example 1 except that the base layer was changed to a film (thickness of 35 μm) produced using a poly-4-methyl-1-pentene resin (manufactured by Mitsui Chemicals, inc.).

Comparative example 4 ]

As shown in table 4, a release film was produced in the same manner as in example 1 except that the base layer was changed to a film (thickness: 25 μm) produced using polybutylene terephthalate elastomer resin (manufactured by dupont-tolay co., ltd.) and the thickness of the release layer was changed to 25 μm.

(4) Measurement/evaluation

Using the obtained release film, the following measurement/evaluation was performed. The results are shown in Table 4.

(a) The 5% tensile strength (5% modulus) of the release film at 180℃was calculated from the S-S curve obtained by measurement according to the tensile test JIS-K7127.

(b) The breaking strength X1 (MPa) at 25℃and the breaking strength X2 (MPa) at 180℃were measured in accordance with JIS-K7127. The obtained X1 and X2 are applied to the following equation to obtain α1.

α1＝((1-(X1-X2)/X1))

(c) Young's modulus of the release film 11 at 180℃was measured in accordance with JIS-K7127.

(d) The dimensional change rate (%) of the release film was measured by Thermal Mechanical Analysis (TMA) using TMA7100 (manufactured by Hitachi High-Tech Science Corporation) at a temperature of 2℃per minute at a temperature of from 30℃to 250 ℃.

(i) Measurement of surface roughness Rz of the release surface of the release film.

According to JIS B0601: 2013.

(ii) Evaluation of appearance of the molded article.

(raw materials)

(step)

Next, the thermosetting resin composition was cured (resin-encapsulated) using each release film as follows.

First, 5 silver pastes were used to bond square semiconductor elements having a thickness of 0.3mm and 7.5mm to an organic substrate having a thickness of 0.4mm, a width of 65mm and a length of 190mm, and gold wires having a diameter of 18 μm and a length of 7mm were bonded at intervals of 60 μm. Then, the mold temperature of the compression molding machine (manufactured by TOWA Corporation, PMC 1040) was set to 175 ℃. Next, the organic substrate is fixed to the upper die so that the surface on which the semiconductor element is mounted faces the lower die. Next, after the mold release films produced in each of examples and comparative examples were placed on the lower mold, the mold interior space was evacuated, thereby making the mold release films follow the mold. Thereafter, the prepared granular thermosetting resin composition (encapsulating resin composition) was uniformly supplied onto the release film. Then, after the encapsulating resin composition was supplied, the mold was closed to a position where the distance between the organic substrate and the release film was 4mm, the pressure in the cavity formed by the lower mold and the upper mold was reduced to a reduced pressure of 0.8Torr over 4 seconds, and then the mold was completely closed over 12 seconds while continuing to reduce the pressure, whereby encapsulation was performed under conditions of a molding pressure of 3.9MPa and a curing time of 90 seconds.

(iii) Evaluation of Release film

[ mold following Property ]

And (3) the following materials: no air pockets were created.

[ dimensional stability ]

And (2) the following steps: no wrinkles, distortion and no problems.

Delta: although there are some wrinkles, there is no problem in practical use.

X: large wrinkles and poor molding were generated.

[ mold releasability ]

And (2) the following steps: the release and molding were not problematic.

Delta: the molded article is offset or deflected during demolding, but there is no problem in practical use.

X: the molded article cannot be released from the mold or is greatly deflected.

[ interlayer Strength ]

In the above step, the state of the release layer when the cured product was released from the molded release film was evaluated according to the following criteria.

And (2) the following steps: there was no peeling of the release layer and no problem.

Delta: although some of the release layer floats from the base material layer, there is no problem in practical use.

X: the release layer was largely peeled from the base material layer.

Experiment 3

(1) Raw materials

The raw material components used in examples and comparative examples shown in table 5 are shown below.

(vinyl-containing organopolysiloxane (A))

(organohydrogen polysiloxane (B))

(inorganic filler)

(silane coupling agent)

(platinum or platinum Compound (E))

(Synthesis of vinyl-containing organopolysiloxane (A))

In the above-mentioned synthesis step (A1-1), 2,4,6, 8-tetramethyl 2,4,6, 8-tetrakis was used in addition to 74.7g (252 mmol) of octamethyl cyclotetrasiloxaneA linear organopolysiloxane (A1-2) having a high vinyl content was synthesized as in the above-described formula (6) in experiment 1, except that 0.86g (2.5 mmol) of vinylcyclotetrasiloxane was used in the same manner as in the synthesis step of (A1-1). (mn=2.3×10 ⁵ ，Mw＝5.0×10 ⁵ ). The vinyl content was 0.93 mol% as measured by H-NMR spectroscopy.

Each of the 1 st resin compositions was prepared in the following manner.

First, a mixture of a vinyl group-containing organopolysiloxane (a), a silane coupling agent, and water (F) was kneaded in advance at a ratio shown in table 5 below, and thereafter, an inorganic filler was added to the mixture to further knead the mixture, thereby obtaining a kneaded product (silicone rubber compound).

Next, to 100 parts by weight of the obtained kneaded material (silicone rubber compound) were added organohydrogen polysiloxane (B) (TC-25D) and platinum or platinum compound (E) (TC-25A) in the proportions shown in Table 5 below, and the mixture was kneaded with rolls to obtain 1 st resin compositions.

TABLE 5

(3) Preparation of release film comprising base layer

In the following manner, release films of examples and comparative examples of experiment 3 were produced.

Example 1 >

As shown in Table 6, biaxially stretched polybutylene terephthalate (OPBT 1: manufactured by TOYOBO CO., ltd.) having a thickness of 15 μm was used as a base layer, an ESTEL (registered trademark) film of Toyobo Co., DE 048) was coated with a paste (solid content 25% by mass, decane solvent) formed from the 1 st resin composition prepared in the above (2) on the base layer using a bar coater, and cured at 180℃for 120 minutes to obtain a release film having a release layer on the base layer. The thickness of the release layer of the obtained release film was 35. Mu.m, and the surface roughness Rz of the release surface of the release layer was 0.1. Mu.m.

Example 2 >

As shown in table 6, a release film was produced in the same manner as in example 1 except that the surface of the release layer was roughened by sandwiching a matte film in the film-forming step using the paste formed from the 1 st resin composition.

Example 3 >

A release film was produced in the same manner as in example 1 except that the thickness of the release layer was changed to 10 μm as shown in table 6.

Example 4 >

A release film was produced in the same manner as in example 1 except that the thickness of the release layer was changed to 70 μm as shown in table 6.

Example 5 >

A release film was produced in the same manner as in example 1 except that the 1 st resin composition for forming the release layer was changed to the composition shown in table 2 as shown in table 6.

Example 6 >

As shown in table 6, a release Film was produced in the same manner as in example 1 except that the base layer was changed to biaxially stretched polybutylene terephthalate (OPET 2: manufactured by KOHJIN Film & Chemicals co., ltd.) having a thickness of 20 μm, and the release layer was changed to be 30 μm.

Example 7 >

As shown in table 6, a release film was produced in the same manner as in example 1 except that the base layer was changed to a biaxially stretched polyethylene terephthalate (OPET 1: manufactured by TOYOBO co., ltd.) and the thickness of the release layer was changed to 41 μm.

Example 8 >

As shown in table 6, a release film was produced in the same manner as in example 1 except that the base layer was changed to a biaxially stretched polyethylene terephthalate (manufactured by TOYOBO co., ltd.) having a thickness of 12 μm, and the release layer was changed to a thickness of 38 μm.

Example 9 >

As shown in table 6, a release film was produced in the same manner as in example 1 except that the base layer was changed to biaxially stretched polyethylene terephthalate (OPET 2: manufactured by eastern spin film solution company (TOYOBO FILM SOLUTIONS ltd.) and the release layer was changed to 37 μm in thickness.

Comparative example 1 >

Comparative example 2 >

As shown in table 6, a release film was produced in the same manner as in example 1 except that the base layer was changed to a biaxially stretched polyethylene terephthalate (OPET 1: manufactured by TOYOBO co., ltd.) and the thickness of the release layer was changed to 31 μm.

Comparative example 3 >

As shown in table 6, a release film was produced in the same manner as in example 1 except that the base layer was changed to a film (thickness of 35 μm) produced using a poly-4-methyl-1-pentene resin (manufactured by Mitsui Chemicals, inc.).

Comparative example 4 ]

As shown in table 6, a release film was produced in the same manner as in example 1 except that the base layer was changed to a film (thickness: 25 μm) produced using polybutylene terephthalate elastomer resin (manufactured by dupont-tolay co., ltd.) and the thickness of the release layer was changed to 25 μm.

(4) Measurement/evaluation

Using the obtained release film, the following measurement/evaluation was performed. The results are shown in Table 6.

(a) And (b): in the Thermal Mechanical Analysis (TMA) measurement, TMA7100 (manufactured by Hitachi High-Tech Science Corporation) was performed at a heating rate of 2℃per minute and a load of 500 mN. From the TMA curve, the dimensional change amount X1 (%) of the length of the release film at 170 ℃, the dimensional change amount X2 (%) of the length of the release film at 190 ℃, the dimensional change amount X3 (%) of the length of the release film at 25 ℃, and the dimensional change amount X4 (%) of the length of the release film at 100 ℃ were obtained, and α1, α1/α2, α1, α2, and α2 were calculated by applying the following formulas, respectively

(X2-X1)/(190-170)＝α1

(X4-X3)/(100-25)＝α2

For the measurement of the Thermal Mechanical Analysis (TMA), a thermal mechanical analysis device (TMA 7100 (Hitachi High-Tech Science Corporation) manufactured by Hitachi Co., ltd.) was used, and the measurement was performed under the following measurement conditions.

(measurement conditions)

Temperature range: 0-250 ℃.

Heating rate: 2 ℃/min.

Load: 500mN.

Test piece: 4mm wide by 10mm.

Test mode: and (5) compressing.

(c) Elongation at break: elongation at break of the release film at 180℃was measured in accordance with JIS-K7127.

(i) Measurement of surface roughness Rz of release surface of release film

According to JIS B0601: 2013.

(ii) Evaluation of appearance of molded article

First, as a resin for encapsulation, an ingot (tablet) of the following granular thermosetting resin composition was produced.

(raw materials)

(step)

(iii) Evaluation of Release film

[ mold following Property ]

And (3) the following materials: no air pockets were created.

[ dimensional stability ]

And (2) the following steps: no wrinkles, distortion and no problems.

Delta: although there are some wrinkles, there is no problem in practical use.

X: large wrinkles and poor molding were generated.

[ mold releasability ]

And (2) the following steps: the release and molding were not problematic.

X: the molded article cannot be released from the mold or is greatly deflected.

[ interlayer Strength ]

X: the release layer was largely peeled from the base material layer.

/>

The present application claims priority based on japanese patent application publication nos. 2021-004017, 2021-004041, 2021-14 and 2021-5-28, and the entire contents of this disclosure are incorporated herein.

Description of the reference numerals

1: a release layer; 2: a 2 nd substrate layer; 3: a 1 st substrate layer; 10: a release film; 11: a demolding surface; 21: a demolding surface; 201: a release layer; 202: a substrate layer; 203: a demolding surface; 211: a release film; 301: a release layer; 302: a substrate layer; 303: a demolding surface; 311: and (5) a release film.

Claims

1. A release film having a multilayer structure comprising a release layer, a 1 st base material layer and a 2 nd base material layer laminated in this order,

The release layer forms a release surface of the release film, the 2 nd base material layer forms a surface of the release film opposite to the release surface,

the release layer comprises 1 or more than 2 selected from silicone resin, fluorine resin, melamine resin, epoxy resin, phenolic resin and acrylic resin,

the 1 st base material layer is composed of a stretched or unstretched film containing 1 or more kinds selected from polyester resins, polyolefin resins and polyamide resins,

the 2 nd base material layer is composed of a stretched or unstretched film containing 1 or 2 or more kinds selected from polyester resins, polyolefin resins and polyamide resins.

2. The release film according to claim 1, wherein,

the release film has a value of 2mN/cm or more as measured by the ring stiffness test.

3. The release film according to claim 1 or 2, wherein,

the release film was subjected to thermal mechanical analysis with a tensile load of 500mN and a dimensional change rate of 4 to 40% at 180℃when the temperature was raised from 30℃to 180℃at 2℃per minute by TMA.

4. The release film according to any one of claims 1 to 3, wherein,

when DMA measurement is performed on the release film under the conditions that the temperature rising speed is 5 ℃/min and the frequency is 1Hz, the storage modulus at 180 ℃ is 10-500 Mpa, and the DMA measurement is dynamic viscoelasticity measurement.

5. The release film according to any one of claims 1 to 4, wherein,

the surface roughness Ra of the surface of the release film on the release layer side is 0.3-2 [ mu ] m.

6. The release film according to any one of claims 1 to 4, wherein,

the surface roughness Ra of the surface of the release film on the release layer side is less than 0.2 [ mu ] m.

7. The release film according to any one of claims 1 to 6, wherein,

the total thickness of the 1 st base material layer and the 2 nd base material layer is 25-70 mu m.

8. The release film according to any one of claims 1 to 7, wherein,

the release film is used for a resin molding process for encapsulating a semiconductor device by resin, and is disposed between a mold and the semiconductor device.