JP6126368B2 - Mold release film for LED encapsulant and method for producing LED encapsulant using the same - Google Patents

Description

  A semiconductor chip including a light emitting diode (LED: hereinafter also simply referred to as “LED”) is usually mounted on a substrate as a resin molded body called a semiconductor package sealed with a sealing resin. Such a semiconductor package is manufactured, for example, by injecting a sealing resin into a mold in which a semiconductor chip is arranged, and curing the injected sealing resin.

  In recent years, with the reduction in size and weight of semiconductor packages, it has been studied to reduce the amount of sealing resin. In addition, even when the amount of the sealing resin is reduced, it has been studied to reduce the amount of the release agent contained in the sealing resin so that the semiconductor chip and the sealing resin are firmly bonded. . For this reason, a method of disposing a release film between the inner surface of the mold and the sealing resin is employed in order to easily release the sealing resin after curing molding from the mold (for example, Patent Document 1). reference).

  As a release film used for molding a resin material, for example, those disclosed in Patent Documents 2 to 7 are known. Patent Document 2 describes a release film having a surface layer made of 4-methyl-1-pentene resin and a support layer made of a polymer alloy containing polyester. Patent Document 3 describes a multilayer inflation film in which a resin layer made of 4-methyl-1-pentene copolymer and a resin layer made of polyolefin or polyamide are laminated.

  In Patent Document 4, as a “release film for producing a multilayer printed circuit board”, A layer (surface layer) / B layer (adhesive layer) / C layer (base material layer) / B ′ layer (adhesive layer) / A A film having a five-layer structure of 'layer (surface layer), wherein A layer (surface layer) and A' layer (surface layer) contain 4-methyl-1-pentene polymer resin is described. Patent Document 5 describes a “release film for manufacturing a semiconductor resin package” having a five-layer structure similar to that described above, and further comprising a modified 4-methyl-1-pentene polymer as a B layer (adhesive layer). In addition, a film in which the C layer (base material layer) contains a polyamide resin is described.

  Patent Document 6 describes a laminated film of a surface layer made of a 4-methyl-1-pentene copolymer and a resin layer made of a polyester copolymer as a “release film for an LED encapsulant”. Yes. As a film for the same application, Patent Document 7 describes a polymer alloy film of 4-methyl-1-pentene copolymer and a thermoplastic elastomer.

Japanese Patent No. 4096659 JP 2000-218752 A JP 2001-62893 A JP 2004-82717 A International Publication No. 2010/023907 JP 2011-240547 A JP 2012-153775 A

  However, the mold used for manufacturing the LED sealing body (package) has a gap (partition between the upper mold and the lower mold) as compared with a mold for manufacturing a normal semiconductor package. The step from the surface to the deepest part of the cavity is large, and the shape is often complicated. The lens portion of the LED sealing body also adjusts the direction of light from the LED elements in the sealing body. Therefore, it is necessary to control the surface state of the LED package so that the light from the LED element can be condensed as designed.

  On the other hand, when the release film described in Patent Documents 2 to 5 and the like is used for LED package manufacturing, the film has high mechanical strength (such as elastic modulus) and cannot extend along the shape of the mold ( In some cases, it did not follow). As a result, “radial wrinkles” may occur in the release film in the mold. Further, even if these release films are forcibly stretched to follow the shape of the mold, the outermost surface of the release layer does not extend uniformly (it does not uniformly stretch and deform), and necking may occur. It was. Thereby, “thickness unevenness” may occur in the release film in the mold. On the other hand, when the mechanical strength of the film is low, the film may stretch too much when stretched along the shape of the mold, resulting in “uneven wrinkles” on the release film in the mold. It was. As a result, the releasability when the resin molded body is peeled from the release film is lowered, and "radial wrinkles", "thickness unevenness" or "uneven wrinkles" are transferred to the surface of the resin molded body, and the appearance In some cases, it was damaged.

  Moreover, since the release film described in Patent Document 7 has too low mechanical strength, the release film may be broken depending on conditions such as mold temperature when the release film is fixed in the mold. there were. As described above, when the release film described in Patent Documents 2 to 7 is used for LED package manufacturing, uneven thickness due to uneven extension of the outermost surface of the release layer and unevenness due to excessive extension of the film locally. It was easy for wrinkles to occur. As a result, the releasability deteriorates locally, a part of the release film remains as a residue, the surface of the LED package becomes rough, and the light from the LED element may not be collected as designed. .

  The present invention has been made in view of the above circumstances, and does not cause tearing of the film or uneven thickness even if it follows a mold having a complicated shape. It aims at providing the release film with the favorable surface state of a molded object.

[1] Outermost layer A containing a base material layer C, a copolymer of 4-methyl-1-pentene and an α-olefin having 2 to 20 carbon atoms other than 4-methyl-1-pentene 1 as a main component. The outermost layer A is a release layer, and the content ratio of the structural unit derived from an α-olefin having 2 to 20 carbon atoms other than the 4-methyl-1-pentene 1 in the copolymer is 1. When the 10-point average roughness RzJIS of the surface of the outermost layer A is 0 μm or more and 1.5 μm or less, and the maximum indentation depth measured at 23 ° C. is D (μm), The mold release film for LED sealing bodies whose dynamic hardness of the outermost layer A defined by a following formula is 0.5-8.0.
Dynamic hardness = 3.8854 × 0.5 / D ²
[2] The mold for LED encapsulant according to [1], wherein the ten-point average roughness RzJIS of the surface opposite to the outermost layer A of the mold release film is 0 μm or more and 1.5 μm or less. Mold release film.
[3] The mold release film for an LED encapsulant according to [1] or [2], further including an adhesive layer B that adheres the base material layer C and the outermost layer A.
[4] The LED encapsulant according to any one of [1] to [3], wherein the content ratio of the constituent unit derived from 4-methyl-1-pentene in the copolymer is 93% by mass or more. Mold release film.
[5] The base layer C, the outermost layer A ′ including the outermost layer A and the copolymer sandwiching the base layer C, the outermost layer A, and the base layer C. The LED sealing body according to any one of [1] to [4], including an adhesive layer B to be bonded and an adhesive layer B ′ to which the other outermost layer A ′ and the base material layer C are bonded. Mold release film.
[6] The mold release film for an LED encapsulant according to any one of [1] to [5], wherein the base material layer C includes a polyamide resin.
[7] The mold release film for an LED encapsulant according to any one of [3] to [6], wherein the adhesive layer B includes a modified 4-methyl-1-pentene copolymer.
[8] The mold release film for an LED encapsulant according to any one of [1] to [7], wherein the base material layer C includes polyamide 6.
[9] The mold release film for an LED encapsulant according to any one of [1] to [8], wherein the tensile fracture stress at 120 ° C. is 4.0 MPa or more and 40 MPa or less.
[10] The mold release film for an LED encapsulant according to any one of [1] to [9], wherein a storage elastic modulus E ′ at 120 ° C. is 30 MPa or more and 200 MPa or less.
[11] In the mold release film for an LED sealing body according to any one of [1] to [10], a surface opposite to the outermost layer A of the release film is in contact with an inner surface of the mold. A step of arranging, a step of arranging an LED mounting substrate in the mold, a sealing resin filling the mold and clamping, and the sealing resin is cured to obtain an LED sealing body. The manufacturing method of a LED sealing body including a process and the process of peeling the obtained said LED sealing body from the said release film.

  The release film of the present invention is excellent in followability to a complex-shaped mold without being broken in the mold, the outermost surface of the release surface is uniformly extended, and the release property from the resin molded body Is excellent. Thereby, a resin molded article having a good appearance can be obtained. The release film of the present invention can be suitably used in a process for producing various resin molded articles using a mold having a relatively complicated shape such as an LED package, taking advantage of these excellent characteristics.

It is a schematic diagram which shows an example of the preferable structure of the release film of this invention. It is a schematic diagram which shows the example of a part of manufacturing apparatus of a film. It is sectional drawing which shows typically the state which has arrange | positioned the release film in the metal mold | die. It is sectional drawing which shows typically the state with which sealing resin was filled in the metal mold | die. It is sectional drawing which shows typically the state which clamps and hardens sealing resin. It is sectional drawing which shows the state of mold opening typically. It is sectional drawing which shows an example of an LED package typically. In the evaluation method of the release film of an Example, it is sectional drawing which shows typically the state which has arrange | positioned the release film in the metal mold | die. In the evaluation method of the release film of an Example, it is sectional drawing which shows typically the state which vacuum-sucks the release film arrange | positioned at the metal mold | die. In the evaluation method of the release film of an Example, it is sectional drawing which shows typically the state which has arrange | positioned sealing resin on a release film. In the evaluation method of the release film of an Example, it is sectional drawing which shows typically the state which clamps and hardens sealing resin. In the evaluation method of the release film of an Example, it is sectional drawing which shows typically the state which opened the mold.

1. The mold release film for LED sealing bodies The mold release film for LED sealing bodies (release film) of this invention has the base material layer C and 4-methyl-1-pentene copolymer as a main component. Including the outermost layer A.

  The release film in the present invention is disposed on the inner surface of the molding die when manufacturing the LED sealing body inside the molding die. By disposing the release film of the present invention on the inner surface of the mold, the obtained LED sealing body can be easily peeled from the mold.

Outermost layer A (release layer)
The outermost layer A is disposed directly on one surface of the base material layer C or via another layer (such as an adhesive layer B), and has a function of imparting releasability to the film. The outermost layer A is disposed so as to be in contact with the LED sealing body in the manufacturing process of the LED sealing body described later. Therefore, the outermost layer A is required to have high release properties and heat resistance.

  The outermost layer A contains 4-methyl-1-pentene copolymer as a main component. The 4-methyl-1-pentene copolymer has a high melting point of 220 to 240 ° C., and not only does not melt at the mold temperature in the production process of the resin molded body, but also has excellent releasability because of low surface energy. In the present invention, the symbol “˜” includes the range of both ends thereof, and the same applies to the following.

  The 4-methyl-1-pentene copolymer refers to a copolymer of 4-methyl-1-pentene and other components other than 4-methyl-1-pentene.

  The other component copolymerized with 4-methyl-1-pentene is preferably an α-olefin having 2 to 20 carbon atoms. Examples of the α-olefin having 2 to 20 carbon atoms include ethylene, propylene, 1-butene, 1-hexene, 1-heptene, 1-octene, 1-decene, 1-tetradecene, 1-hexadecene and 1-heptadecene. 1-octadecene, 1-eicosene and the like. These α-olefins may be used alone or in combination of two or more.

  The α-olefin having 2 to 20 carbon atoms is preferably an α-olefin having 7 to 20 carbon atoms, more preferably an α-olefin having 8 to 20 carbon atoms, and further preferably 12 carbon atoms. ~ 20 alpha olefins.

  The content ratio of the constituent unit derived from 4-methyl-1-pentene in the 4-methyl-1-pentene copolymer is preferably 93% by mass or more, more preferably 93 to 99% by mass, and 93 to 95% by mass. Further preferred. Such 4-methyl-1-pentene copolymer has good rigidity derived from 4-methyl-1-pentene and good moldability derived from α-olefin.

  In the 4-methyl-1-pentene copolymer, the content of the structural unit derived from the α-olefin having 2 to 20 carbon atoms is 1% by mass or more in order to keep the crystallinity below a certain level. Is preferable, and it is more preferable that it is 5 mass% or more. The upper limit of the content ratio of the structural unit derived from an α-olefin having 2 to 20 carbon atoms can be, for example, about 7% by mass.

  The 4-methyl-1-pentene copolymer preferably has crystallinity. Specifically, the 4-methyl-1-pentene copolymer preferably has an isotactic structure or a syndiotactic structure, and more preferably has an isotactic structure. The molecular weight of the 4-methyl-1-pentene copolymer is not particularly limited as long as it satisfies the moldability and mechanical properties.

  According to ASTM D1238, the melt flow rate (MFR) of the 4-methyl-1-pentene copolymer measured at a load of 5.0 kg and a temperature of 260 ° C. is 0.5 to 250 g / 10 min. Preferably, it is 1.0 to 150 g / 10 min. When the MFR of the 4-methyl-1-pentene copolymer is in the above range, the film forming property and the mechanical properties of the obtained film are excellent.

  The 4-methyl-1-pentene copolymer can be produced by any method. For example, 4-methyl-1-pentene can be obtained by polymerizing in the presence of a known catalyst such as a Ziegler-Natta catalyst or a metallocene catalyst. The 4-methyl-1-pentene copolymer used in the present invention may be one produced as described above; it may be a commercial product. Examples of commercially available 4-methyl-1-pentene copolymers include TPX manufactured by Mitsui Chemicals.

  The outermost layer A may further contain other resins and additives in addition to the 4-methyl-1-pentene copolymer as long as the object of the present invention is not impaired. Examples of the additive include known additives usually blended in polyolefins such as a heat resistance stabilizer, a weather resistance stabilizer, a rust inhibitor, a copper damage resistance stabilizer, and an antistatic agent. The content of the compound other than 4-methyl-1-pentene copolymer is preferably 0.0001 parts by mass or more and less than 10 parts by mass with respect to 100 parts by mass of 4-methyl-1-pentene copolymer. .

  As described above, a mold used for manufacturing an LED sealing body or the like tends to have a more complicated shape and a larger gap than a normal mold used for manufacturing a semiconductor resin package or the like. The conventional release film has high mechanical strength, and when used in a mold used for manufacturing an LED encapsulant or the like, it is difficult to follow the shape of the mold, and the outermost surface of the release film is not uniform. Elongation may cause “thickness unevenness” on the surface of the release film. When such thickness unevenness occurs, the releasability of the release film is locally lowered, a part of the release film remains as a residue, and the surface of the LED package that is a resin molded body may be roughened.

  Therefore, in the present invention, the followability with respect to the shape of a mold used for manufacturing an LED sealed body or the like is increased, the releasability from the resin molded body is increased, and the obtained LED sealed body is further separated from the LED element. In order to obtain a surface state that does not hinder the collection of light, it is preferable that the dynamic hardness of the surface of the outermost layer A is made constant or less. Specifically, the dynamic hardness of the surface of the outermost layer A is preferably 0.5 or more and 8.0 or less, more preferably 0.5 or more and 5.0 or less, and 0.5 or more and 4 or less. More preferably, it is 0.0 or less.

The dynamic hardness of the outermost layer A can be calculated by the following method.
1) First, the maximum indentation depth D in the load-unloading test mode of the outermost layer A of the release film using a dynamic ultra-micro hardness meter DUH-W201S (diamond triangular cone indenter 115 °) manufactured by Shimadzu Corporation (Μm) is measured. The measurement conditions may be a temperature of 23 ± 2 ° C., a humidity of 50 ± 5%, a test load (P) of 0.50 mN, a load speed of 0.142 mN / sec, and a holding time of 5 sec.
2) The measured value of the obtained maximum indentation depth D is applied to the following formula to calculate the dynamic hardness.
Dynamic hardness = 3.8854 × 0.5 / D ²

  The dynamic hardness of the outermost layer A is related to the crystallinity of the surface of the outermost layer A. The higher the crystallinity of the surface, the higher the dynamic hardness; the lower the crystallinity, the lower the dynamic hardness. .

  In general, it is considered that the higher the crystallinity (the higher the dynamic hardness), the higher the releasability. On the other hand, in the manufacturing process of the LED encapsulant and the like, the present inventors have a relatively low moldability (reducing the dynamic hardness) by lowering the crystallinity of the surface of the outermost layer A. I found it to increase.

  Although this reason is not necessarily clear, it is guessed as follows. That is, the release film is more easily stretched (stretched) in a mold used for manufacturing an LED encapsulant than in a normal mold. At this time, if the crystallinity of the surface of the outermost layer A of the release film in contact with the resin molded body is low, the surface of the outermost layer A is easily stretched and deformed uniformly (easily stretched). Locally stretched portions are reduced and thickness unevenness (unevenness) is unlikely to occur. Thereby, at the time of shaping | molding, it is thought that sealing resin suppresses entering between the unevenness | corrugation of a release film and a LED mounting substrate, and mold release property improves. Moreover, since uneven thickness (unevenness) on the surface of the release film is suppressed, transfer of uneven thickness (irregularity) to the surface of the resin molded body can be suppressed, and a resin molded body (LED package) having a good appearance. Can be obtained. Moreover, generation | occurrence | production of the residue of a release film by the local deterioration of mold release property can be suppressed, and the resin molding (LED package) with a favorable surface state can be obtained.

  Furthermore, as a result of the outermost layer A being uniformly stretched and deformed (stretched), the number of locally stretched portions is reduced, and the mechanical strength is easily maintained. As a result, it is thought that tearing of the release film during mold molding can be suppressed.

  As described above, the dynamic hardness of the outermost layer A can be adjusted by the crystallinity of the outermost layer A; the crystallinity of the outermost layer A depends on the constituent material of the outermost layer A (specifically, 4- And the like, and the temperature of the cast roll in the film production process.

  In order to reduce the crystallinity of the surface of the outermost layer A and reduce the dynamic hardness, for example, other than 4-methyl-1-pentene in the 4-methyl-1-pentene copolymer of the outermost layer A Increasing the content of the α-olefin having 2 to 20 carbon atoms, which is a component of the above; increasing the number of carbon atoms of the α-olefin; adjusting the cast roll temperature in the film production process preferable.

  In the present invention, in the production process of a resin molded body such as an LED sealing body to be described later, the resin molded body is improved in order to improve the gloss of the surface of the obtained resin molded body and to further improve the releasability from the resin molded body. It is preferable to make the surface roughness of the outermost layer A in contact with the surface below a certain level. Specifically, the ten-point average roughness RzJIS of the surface of the outermost layer A is preferably 0 μm or more and 1.5 μm or less, more preferably 0 μm or more and 1.0 μm or less, and 0 μm or more and 0.5 μm or less. More preferably.

  That is, if the roughness of the surface of the outermost layer A is too large, the rough surface shape of the surface of the outermost layer A is transferred to the surface of the LED sealing body that is a resin molded body during mold molding. The lens portion of the LED sealing body is also for adjusting the direction of light from the LED elements in the sealing body. Therefore, if the surface of the LED sealing body has irregularities due to the rough surface shape, the light from the LED element diffuses, and it may be difficult to collect the light as designed.

  Further, if the surface roughness of the outermost layer A is too large, the liquid molding resin enters the irregularities on the surface of the outermost layer A during mold molding, so that the release film from the resin molded body after the molding resin is cured The releasability of may decrease.

  On the other hand, if the 10-point average roughness RzJIS of the surface of the outermost layer A is in the range of 0 μm or more and 1.5 μm or less, the smoothness of the surface of the outermost layer A is transferred to the surface of the resin molded body, Condensation can be reproduced as designed. In addition, since the liquid molding resin does not easily enter the irregularities on the surface of the outermost layer A, the mold release from the resin molded body is further facilitated. Moreover, since it is difficult to form a gap between the release film and the substrate in the mold, it is possible to suppress the occurrence of burrs in the resin molded body and to accurately reproduce the mold shape.

  The ten-point average roughness RzJIS of the surface of the outermost layer A is a method in accordance with JIS-B0601; specifically, using a surface roughness type measuring instrument (manufactured by Tokyo Seimitsu Co., Ltd., surfcom 130A), a measurement length of 40 mm, It can be measured at a speed of 0.3 mm / s.

  The ten-point average roughness RzJIS of the surface of the outermost layer A can be adjusted by, for example, the surface roughness of the cast roll or the surface roughness of the touch roll in the film production process described later.

  As described above, when the release film of the present invention has a low mechanical strength, it may be stretched locally in the mold, and uneven mold may occur in the release film in the mold. For example, a single-layer film of 4-methyl-1-pentene copolymer, which is the main component of the outermost layer A, has a yield point, and therefore tends to be unevenly deformed when stretch-deformed. Thereby, uneven wrinkles due to excessive stretching of the film tend to occur. Similar to the above, such uneven ridges also cause a local decrease in releasability and cause the surface of the LED package, which is a resin molded body, to become rough.

  This uneven surface can be solved by including the base material layer C that is uniformly deformed at the mold temperature in the release film of the present invention. Therefore, the base material layer C is preferably composed of a material that does not have a yield point.

Base material layer C
The base material layer C has a function as a base material of the release film. Therefore, it is preferable that the base material layer C is excellent in heat resistance and mechanical properties. In particular, the resin that is the main component of the base material layer C is preferably superior in strength and creep resistance at a higher temperature than the 4-methyl-1-pentene copolymer that is the main component of the outermost layer A. The high temperature here means the mold temperature when producing the resin molded body.

  Examples of such resins include polycarbonate resins, polyester resins and polyamide resins. Of these, polyamide resins are preferable, and aliphatic polyamide resins are more preferable. Since these polyamide resins have higher adhesiveness with the modified 4-methyl-1-pentene polymer contained in the adhesive layer B described later, compared to polyester resins such as polyethylene terephthalate resin, the outermost layer A and the base resin Delamination with the material layer C can be effectively suppressed.

  The aliphatic polyamide resin can be obtained by ring-opening polymerization of lactam; polycondensation reaction between an aliphatic diamine component and an aliphatic dicarboxylic acid component; or polycondensation of an aliphatic aminocarboxylic acid.

  Examples of the aliphatic polyamide obtained by ring-opening polymerization of lactam include polyamide 6, polyamide 11, polyamide 12 and polyamide 612. Examples of the aliphatic polyamide obtained by polycondensation of an aliphatic diamine component and an aliphatic dicarboxylic acid component include polyamide 66, polyamide 610, polyamide 46, polyamide MXD6, polyamide 6T, polyamide 6I, and polyamide 9T.

  Of these, polyamide 6 or polyamide 66 is preferred; polyamide 6 is more preferred. This is because these polyamides not only have good adhesion to the adhesive layer B described later, but also have a high melting point and a high elastic modulus, and are excellent in heat resistance and mechanical properties. The release film having the base material layer C containing these polyamides is not only less likely to be wrinkled in the mold, but also less likely to be pinhole-shaped. If the leakage of the sealing resin through the pinhole-like breakage is significant, a part of the component of the sealing resin adheres to and accumulates on the inner wall of the mold cavity, which is not preferable.

  The melting point of aliphatic polyamide measured by DSC method is preferably 190 ° C. or higher. This is because a release film having an aliphatic polyamide having a melting point lower than 190 ° C. as the base material layer C may not have sufficient heat resistance and is likely to be wrinkled.

  The base material layer C may be a multilayer, for example, three layers as indicated by “C / C ′ / C”. In that case, it is preferable that at least one of the base material layer C and the base material layer C ′ includes the polyamide 6.

  The base material layer C may further include other resins other than the above-described polyamide resin and the like. Preferred examples of other resins include heat-resistant elastomers that are superior in creep resistance to tensile stress and compressive stress at high temperatures and stress relaxation than 4-methyl-1-pentene polymers that are the main component of outermost layer A. Heat resistant elastomers that are difficult to resist and have high elastic recovery properties are included.

  Examples of such heat resistant elastomers include thermoplastic polyamide-based elastomers, thermoplastic polyester-based elastomers, and the like in consideration of adhesiveness with the adhesive layer B.

  Examples of the thermoplastic polyamide-based elastomer include a block copolymer having polyamide as a hard segment and polyester or polyether as a soft segment. Examples of the polyamide constituting the hard segment include polyamide 6, polyamide 66, polyamide 610, polyamide 612, polyamide 11 and the like. Examples of the polyether constituting the soft segment include polyethylene glycol (PEG), polypropylene glycol (PPG), polytetramethylene glycol (PTMG), and the like.

  Examples of thermoplastic polyester elastomers include block copolymers in which a crystalline polymer composed of crystalline aromatic polyester units is used as a hard segment, and an amorphous polymer composed of polyether units or aliphatic polyester units is used as a soft segment. A polymer is included. Examples of the crystalline polymer comprising crystalline aromatic polyester units constituting the hard segment include polybutylene terephthalate (PBT) and polybutylene naphthalate (PBN). Examples of the amorphous polymer composed of polyether units constituting the soft segment include polytetramethylene ether glycol (PTMG). Examples of the amorphous polymer composed of aliphatic polyester units constituting the soft segment include aliphatic polyesters such as polycaprolactone (PCL).

  Specific examples of the thermoplastic polyester elastomer include a block copolymer of polybutylene terephthalate (PBT) and polytetramethylene ether glycol (PTMG); a block copolymer of polybutylene terephthalate (PBT) and polycaprolactone (PCL). Polymers; block copolymers of polybutylene naphthalate (PBN) and aliphatic polyesters are included.

  The melting point of the thermoplastic polyamide-based elastomer and the thermoplastic polyester-based elastomer measured by the DSC method is preferably 190 ° C. or higher. Even if the melting point of the thermoplastic elastomer is less than 190 ° C., the thermoplastic elastomer is chemically crosslinked with a crosslinking agent or a crosslinking aid, or physically crosslinked with ultraviolet rays, electron beams, gamma rays, or the like. Thus, creep resistance and elastic recovery at high temperatures may be improved.

  The base material layer C may further contain a known additive as long as the object of the present invention is not impaired. When the base material layer C contains a polyamide resin as a main component, the additive is, for example, a heat-resistant stabilizer containing a copper compound for the purpose of improving heat aging; known additives such as lubricants such as calcium stearate and aluminum stearate It may be an agent.

  As described above, even if the dynamic hardness of the outermost layer A is below a certain level, if the base material layer C has a yield point at the mold temperature or the mechanical strength is too low, the mold of the release film At the time of fixing to a mold or molding a mold, the release film may be excessively stretched locally, resulting in irregularities. Such uneven ridges may be transferred to the surface of the resin molded body, resulting in poor appearance. Therefore, the base material layer C does not have a yield point, and the storage elastic modulus E ′ at 120 ° C. is preferably within a certain range, for example, preferably 15 MPa or more and 1000 MPa or less.

Adhesive layer B
In order to improve the interlayer adhesion between the base material layer C and the outermost layer A, the release film of the present invention preferably further includes an adhesive layer B that adheres the base material layer C and the outermost layer A.

  The adhesive layer B is disposed between the base material layer C and the outermost layer A. By disposing the adhesive layer B, it is possible to suppress delamination between the base material layer C and the outermost layer A at a location where stress tends to concentrate on the release film in the mold when the mold is clamped. The part where the stress tends to concentrate is, for example, a peripheral part of the mold cavity (a boundary part between the cavity surface of the mold and the parting surface).

  The adhesive layer B preferably contains a resin that is easily compatible with both the outermost layer A and the base material layer C. Therefore, the resin that is the main component of the adhesive layer B is a resin obtained by modifying 4-methyl-1-pentene copolymer, which is the main component of the outermost layer A, so as to be easily compatible with the base material layer C (modified 4-methyl). -1-pentene copolymer). Since the base material layer C preferably contains a polyamide resin, the modified 4-methyl-1-pentene copolymer is obtained by converting the 4-methyl-1-pentene copolymer into an unsaturated carboxylic acid and its acid anhydride. It is preferably modified with at least one (hereinafter also referred to as “unsaturated carboxylic acid etc.”).

  The 4-methyl-1-pentene copolymer modified with an unsaturated carboxylic acid or the like is obtained by copolymerizing a 4-methyl-1-pentene copolymer with an unsaturated carboxylic acid or the like, preferably 4-methyl- It can be obtained by graft polymerization of 1-pentene copolymer and unsaturated carboxylic acid. Graft polymerization of 4-methyl-1-pentene copolymer and unsaturated carboxylic acid or the like may be carried out by a known method, for example, 4-methyl-1-pentene copolymer and unsaturated carboxylic acid or the like such as peroxide. It can be carried out by melt-kneading in the presence.

  The 4-methyl-1-pentene copolymer to be modified may preferably be the aforementioned 4-methyl-1-pentene copolymer. The 4-methyl-1-pentene copolymer to be modified may be the same as or different from that of the outermost layer A. The intrinsic viscosity [η] of the modified 4-methyl-1-pentene copolymer measured in decahydronaphthalene at 135 ° C. is preferably 0.5 to 25 dl / g, preferably 0.5 to 5 dl / g. Is more preferable.

  Examples of the unsaturated carboxylic acid include unsaturated compounds having 3 to 20 carbon atoms having a carboxyl group and an unsaturated group, unsaturated compounds having 3 to 20 carbon atoms having a carboxylic anhydride group and an unsaturated group, and the like. It is. Examples of the unsaturated group include a vinyl group, a vinylene group, and an unsaturated cyclic hydrocarbon group.

  Specific examples of unsaturated carboxylic acids include unsaturated monocarboxylic acids such as acrylic acid and methacrylic acid; maleic acid, fumaric acid, itaconic acid, citraconic acid, allyl succinic acid, mesaconic acid, glutaconic acid, nadic acid TM Unsaturated dicarboxylic acids such as methyl nadic acid, tetrahydrophthalic acid, methyl hexahydrophthalic acid; and maleic anhydride, itaconic anhydride, citraconic anhydride, allyl succinic anhydride, glutaconic anhydride, nadic acid anhydride TM, methyl nadic anhydride Examples thereof include unsaturated dicarboxylic acid anhydrides such as acid, tetrahydrophthalic anhydride, and methyltetrahydrophthalic anhydride. Among these, maleic acid, maleic anhydride, nadic acid TM, or nadic anhydride TM is preferable, and maleic anhydride is more preferable. These may be used alone or in combination of two or more.

  The graft ratio of the modified 4-methyl-1-pentene copolymer (hereinafter also referred to as “modified 4-methyl-1-pentene copolymer”) is preferably 20% by mass or less. More preferably, it is 5 mass%, and it is further more preferable that it is 0.5-2 mass%. The modified 4-methyl-1-pentene copolymer having a graft ratio in the above range has good adhesion to both the outermost layer A and the base material layer C.

  It is preferable that the modified 4-methyl-1-pentene copolymer has substantially no crosslinked structure. The fact that the modified 4-methyl-1-pentene polymer does not have a crosslinked structure means that the modified 4-methyl-1-pentene copolymer is dissolved in an organic solvent such as p-xylene to form a gel-like product. Can be confirmed by the absence of.

  The intrinsic viscosity [η] of the modified 4-methyl-1-pentene copolymer measured in decahydronaphthalene at 135 ° C. is preferably 0.2 to 10 dl / g, and preferably 0.5 to 5 dl / g. More preferably, it is g.

  The resin as the main component of the adhesive layer B may be only the above-mentioned modified 4-methyl-1-pentene copolymer, or the modified 4-methyl-1-pentene copolymer and other α-olefin polymers. It may be a mixture with coalescence. The content ratio of the modified 4-methyl-1-pentene copolymer in the mixture of the modified 4-methyl-1-pentene copolymer and another α-olefin polymer is preferably 20 to 40% by mass. .

  The α-olefin polymer is preferably an α-olefin polymer having 2 to 20 carbon atoms. Examples of the α-olefin polymer having 2 to 20 carbon atoms include polymers such as ethylene, propylene, 1-butene, 1-hexene, 1-octene, 1-decene, 1-tetradecene and 1-octadecene. It is. Among these, a 1-butene polymer is preferable.

  The 1-butene polymer may be a homopolymer of 1-butene or a copolymer of 1-butene and an α-olefin having 2 to 20 carbon atoms other than 1-butene. Examples of α-olefins having 2 to 20 carbon atoms other than 1-butene include ethylene, propylene, 1-hexene, 1-octene, 1-decene, 1-tetradecene, 1-octadecene, etc .; preferably Ethylene or propylene.

  The 1-butene polymer preferably contains 60% by mass or more, more preferably 80% by mass or more of a structural unit derived from 1-butene. This is because such a 1-butene polymer is excellent in miscibility (or compatibility) with the modified 4-methyl-1-pentene copolymer.

  The melt flow rate (MFR) of the 1-butene polymer measured at a load of 2.16 kg and a temperature of 190 ° C. in accordance with ASTM D1238 is preferably 0.01 to 100 g / 10 min. It is more preferable that it is 1-50 g / 10min. The 1-butene polymer having an MFR in the above range has good mixing properties (or compatibility) with the modified 4-methyl-1-pentene copolymer, and can improve the adhesiveness of the adhesive layer B.

  Similar to the outermost layer A and the base material layer C, the adhesive layer B may also contain the aforementioned additives in addition to the main component.

  The substrate layer C and the adhesive layer B included in the release film of the present invention may be either one or plural. When the base material layer C is a multilayer, a plurality of base material layers may be directly laminated, or another layer (for example, an adhesive layer) may be further disposed between the base material layers.

Other outermost layer A '
The release film of the present invention may further include a layer other than the layers described above, if necessary. Examples of such a layer include other outermost layers that are disposed on the other surface of the base material layer C directly or via an adhesive layer B and constitute the surface opposite to the outermost layer A of the release film. An outer layer A ′ is included.

  In order to obtain not only mold releasability from the resin molded body but also mold releasability from the mold, the other outermost layer A ′ may contain a 4-methyl-1-pentene polymer as a main component. preferable.

  The 4-methyl-1-pentene polymer contained in the other outermost layer A ′ may be a homopolymer of 4-methyl-1-pentene, but 4-methyl-1-pentene and other other polymers. A copolymer with a component (4-methyl-1-pentene copolymer) may be used. Examples of the 4-methyl-1-pentene copolymer contained in the other outermost layer A ′ include those similar to the 4-methyl-1-pentene copolymer contained in the outermost layer A.

  The ten-point average roughness RzJIS of the surface of the other outermost layer A ′ is not particularly limited, but it is preferably not more than a certain value like the outermost layer A ′. This is because not only the irregularities caused by RzJIS of the outermost layer A ′ but also other outermost layers by applying a certain molding pressure to the release film and the resin molded body in the manufacturing process of the LED sealing body described later. This is because unevenness caused by Az RzJIS (RzJIS of the surface in contact with the mold) may be transferred to the resin molded body.

  That is, the ten-point average roughness RzJIS of the surface of the other outermost layer A ′ is preferably 0 μm or more and 1.5 μm or less, more preferably 0 μm or more and 1.0 μm or less, and 0 μm or more and 0.5 μm or less. More preferably.

  The ten-point average roughness RzJIS of the surface of the other outermost layer A ′ is adjusted by the surface roughness of the cast roll or touch roll (preferably the surface roughness of the touch roll) in the film production process, as described above. be able to.

  Of course, when the base material layer C has not only heat resistance but also releasability, the layer constituting the surface opposite to the outermost layer A of the release film may be the base material layer C. .

Examples of the specific laminated structure of the release film of the present invention include the following aspects. In the following embodiments, A is the outermost layer A; B is the adhesive layer B; C is the substrate layer C; A ′ is the other outermost layer A ′; C ′ is the substrate layer C. D is an adhesive layer that bonds the base material layer C and the base material layer C ′.
A / C
A / C / A '
A / B / C
A / B / C / B / A '
A / B / C / C '/ C / B / A'
A / B / C / D / C '/ D / C / B / A'

  Among these, a five-layer structure of “A / B / C / B / A ′” is preferable because it is easy to manufacture. FIG. 1 is a schematic view showing an example of a preferred configuration of the release film of the present invention. As shown in FIG. 1, the release film 10 includes a base material layer 11, an outermost layer 15 that sandwiches the base material layer 11, another outermost layer 15 ′ that constitutes a surface opposite to the base material layer 11, and a base material It has a pair of contact bonding layer 13 arrange | positioned between the layer 11 and the outermost layer 15, or between the base material layer 11 and other outermost layer 15 '. The base layer 11 is the base layer C; the outermost layer 15 is the outermost layer A; the adhesive layer 13 is the adhesive layer B; the other outermost layer 15 ′ is the other outermost layer A ′. .

  The outermost layer 15 constituting one surface of the release film 10 is in contact with the obtained resin molding; the other outermost layer 15 ′ constituting the other surface is in contact with the inner surface of the mold. Therefore, the release film 10 can have good release properties from the inner surface of the mold as well as release properties from the obtained resin molding.

  Thus, it is preferable that the release film 10 has a symmetrical laminated structure with respect to the center layer. This is because the release film having a symmetric laminated structure is less likely to be deformed (warped or the like) due to a difference in thermal expansion or moisture absorption when heated in a mold.

  In addition, a pair of layers (layers made of the same material) arranged at positions symmetrical to the center layer of the release film 10 such as the outermost layer 15 and the other outermost layer 15 ′ and a pair of adhesive layers 13. It is preferable to have the same thickness. This is because the deformation amounts (warping, etc.) of the release film can be highly suppressed by canceling out the deformation amounts due to the coefficient of thermal expansion.

Physical properties of release film The total thickness of the release film is preferably 20 to 100 µm, and more preferably 40 to 60 µm. By setting the total thickness of the release film to a certain level or more, it is easy to ensure the mechanical strength of the film. On the other hand, by setting the total thickness of the release film to a certain value or less, good followability can be easily obtained even for a complicatedly shaped mold.

  Specifically, if the total thickness of the release film is too large, the mechanical strength becomes too high, and it may be difficult to follow the fine shape of the mold (followability to the mold will be reduced). Thereby, there is a possibility that the shape of the mold cannot be faithfully reproduced, or the size of the resin molded body may be smaller than the design. Thereby, excess sealing resin may leak from the mold. On the other hand, if the total thickness of the release film is too small, the mechanical strength of the release film is too low, and the release film may be torn in the molding process, causing problems such as resin leakage.

  The thickness of each layer of a release film should just be adjusted so that the total thickness of a release film may become the said range. Specifically, the thickness of the outermost layer A is preferably 1 to 30 μm, and more preferably 5 to 15 μm. The thickness of the adhesive layer B is preferably 1 to 20 μm; the thickness of the base material layer C is preferably 10 to 40 μm.

  When there are a plurality of adhesive layers B and substrate layers C, the total thickness of the plurality of adhesive layers B is preferably 2 to 20 μm, and the total thickness of the plurality of substrate layers C is preferably 20 to 40 μm. . When there are a plurality of adhesive layers B, the thickness of each adhesive layer B is preferably 1 to 10 μm.

  The thickness of the other outermost layer A ′ may be the same as that of the outermost layer A, and may be, for example, 1 to 30 μm, and preferably 5 to 15 μm.

  In order to further improve the followability of the release film to the mold shape, it is necessary to adjust the storage elastic modulus E 'at the mold temperature. Since a typical example of the mold temperature is 120 ° C., the storage elastic modulus E ′ at 120 ° C. is preferably used as a guide. That is, the storage elastic modulus E ′ at 120 ° C. of the release film of the present invention is preferably 30 MPa or more and 200 MPa or less, and more preferably 65 MPa or more and 150 MPa or less. Depending on the type of sealing resin, the mold temperature may be higher than 120 ° C., but if the release elastic modulus E ′ at 120 ° C. is in this range, it can be used without problems such as poor appearance. .

  When the storage elastic modulus E ′ at 120 ° C. of the release film is less than 30 MPa, the release film is too soft, so that the release film is stretched locally at the time of fixing to the mold or when the mold is formed. May cause wrinkles. Thereby, the uneven ridges may be transferred to the surface of the resin molded body, resulting in poor appearance. On the other hand, when the storage elastic modulus E ′ at 120 ° C. is more than 150 MPa, the release film is too hard, so that it cannot extend along the shape of the mold (it cannot follow up) and cannot be brought into close contact with the mold surface. there is a possibility. Thereby, radial wrinkles are generated, and the wrinkles may be transferred to the surface of the resin molded body, resulting in poor appearance.

The storage elastic modulus E ′ of the release film can be measured according to the following method.
Using a dynamic viscoelastic device RSA-II (manufactured by TA Instruments), tensile mode: vibration frequency 1 Hz, measurement speed: speed of 3 ° C./minute from −80 ° C. to a temperature at which the sample melts and becomes unmeasurable The elastic modulus in the conveyance direction (MD direction) of the release film is measured while raising the temperature at, and the storage elastic modulus E ′ at 120 ° C. is calculated.

  The storage elastic modulus E ′ of the release film can be adjusted mainly by the type of the base layer C and the outermost layer A.

  In order to suppress breakage of the release film during fixing to the mold or during mold forming, the tensile fracture stress at 120 ° C. of the release film of the present invention is preferably 4 MPa or more and 40 MPa or less, preferably 10 MPa or more. More preferably, it is 25 MPa or less.

  When the tensile fracture stress at 120 ° C. is less than 4 MPa, the film is easily broken when vacuum-adsorbed for mounting the release film on the mold. For this reason, there is a possibility that a vacuum leak occurs and the release film cannot be adsorbed in the mold, or the sealing resin leaks from the torn part and contaminates the mold. On the other hand, when the tensile fracture stress at 120 ° C. is more than 40 MPa, radial wrinkles that are considered to be derived from the film are transferred to the resin molded body, which may cause poor appearance.

The tensile fracture stress of the release film can be measured according to the following method.
1) As a test piece, a strip piece cut out from a release film with a width of 10 mm is prepared. The longitudinal direction of the strip should be parallel to the film transport direction.
2) The test piece is held by a tensile tester with a thermostat adjusted to 120 ° C. so that the distance between chucks is 10 mm. Then, the test piece is pulled at a tensile speed of 20 mm / min (constant). The tensile fracture stress in the obtained tensile stress-strain curve is determined according to JIS-K7161.

  The tensile fracture stress of the release film can be adjusted mainly by the type of the base material layer C.

  In the release film of the present invention, the dynamic hardness of the outermost layer A in contact with the resin molded body is adjusted to a certain level or less. Therefore, when the release film is fixed to the mold or when the mold is formed; particularly when the mold is formed, the surface of the outermost layer A is easily stretched and deformed without breaking the release film. Unevenness in thickness can be suppressed. Thereby, the mold release property from a resin molding can be improved, and a resin molding with few external appearance defects can be obtained.

  Moreover, the release film of the present invention further has a base material layer C. Therefore, when the release film is fixed to the mold or when the mold is formed, it is possible to further suppress uneven wrinkles due to excessive extension of the release film locally. Thereby, the releasability from the resin molded body can be further enhanced, and a resin molded body with few appearance defects can be obtained.

2. Release Film Production Method The release film of the present invention can be produced by any method. For example, it can be obtained by coextrusion of the melt of the material for the outermost layer A containing the aforementioned 4-methyl-1-pentene copolymer and the melt of the material for the base layer C.

  That is, the release film of the present invention is obtained by laminating a melt of the outermost layer A material containing at least the aforementioned 4-methyl-1-pentene copolymer and a melt of the material for the base layer C. The step of co-extrusion while 2) the step of cooling and solidifying the co-extruded laminate on a cast roll (cooling roll) can be obtained. Hereinafter, an example of producing a release film 29 having a three-layer structure of outermost layer A / adhesive layer B / base material layer C will be described with reference to FIG.

  FIG. 2 is a schematic diagram showing an example of a part of a film manufacturing apparatus. As shown in FIG. 2, the film manufacturing apparatus 20 mainly includes a die 21 a having a feed block 21 b, and a cast roll 23 and a touch roll 25 that cool while sandwiching a melt extruded from the die 21 a. Have.

  Each melt of the material for outermost layer A, the material for adhesive layer B, and the material for base material layer C in step 1) can be obtained by melt-kneading with a melt extruder. The melts of the outermost layer A material, the adhesive layer B material, and the base material layer C material are supplied to the feed block 21b through the conduits 21b1, 21b2, and 21b3, respectively. In the feed block 21b, the melt for each layer is laminated so as to have a predetermined layer configuration, and is supplied to the die 21a through the conduit 21b4. And the laminated | stacked molten material is extruded to a film form from the slit port of dice | dies 21a (for example, T-type dice | dies).

  Although FIG. 2 shows an example of a feed block stacking method using dies having feed blocks, the present invention is not limited to this, and a multi-hold die method, a dual slot die method, or the like may be adopted.

  In the step 2), the extruded melt is solidified while being narrowed by the cast roll 23 and the touch roll 25 to obtain a film-like laminate.

  In order to accurately adjust the dynamic hardness of the outermost layer A to be obtained, it is preferable to extrude the melt so that the melt of the material for the outermost layer A is in contact with the cast roll 23.

  The material of the cast roll 23 is preferably a metal roll. The temperature of the cast roll 23 is preferably adjusted so that the dynamic hardness of the outermost layer A to be obtained falls within the above-mentioned range. That is, if the temperature of the cast roll 23 is too low, there is a possibility that distortion may remain in the obtained laminate or the crystallinity may be too low. If the temperature of the cast roll 23 is too high, the cooling becomes insufficient, and the crystallinity of the surface layer of the resulting laminate may become too high. Although the temperature of the cast roll 23 changes with the kind of melt, a manufacturing apparatus, etc., it is preferable to set it as 15-80 degreeC, for example, and it is more preferable that it is 15-40 degreeC.

  The surface roughness of the cast roll 23 may be adjusted so that RzJIS of one surface (preferably the surface of the outermost layer A) of the obtained laminate is in the above-described range.

  The touch roll 25 may be a flexible roll having a thin metal outer cylinder having flexibility. The temperature of the touch roll 25 can be the same as the temperature of the cast roll 23. The surface roughness of the touch roll 25 may be adjusted so that the RzJIS of the other surface (preferably the surface of the other outermost layer A ′ or the base material layer C) of the obtained laminate is in the above range.

  The laminate obtained by solidification while being sandwiched between the cast roll 23 and the touch roll 25 may be further conveyed by another roll 27 or the like as necessary. Thereby, for example, a release film 29 having a laminated structure of outermost layer A / adhesive layer B / base material layer C can be obtained.

3. Molding Method Using Release Film The release film of the present invention is suitably used as a release film for mold molding, and is particularly preferably used for the production of resin-encapsulated semiconductors; particularly LED packages.

  The LED package manufacturing method of the present invention includes a first step of arranging a release film in a molding die, a second step of arranging an LED mounting substrate in the die, and a sealing resin in the die. The mold is clamped, the sealing resin is cured to obtain an LED sealing body, and the fourth step of peeling the obtained LED sealing body from the release film is included.

  As shown in FIG. 3, the release film 31 is disposed on a lower mold 33 b of a molding mold 33 including an upper mold 33 a and a lower mold 33 b in which a cavity 32 having a predetermined shape is formed.

  The release film 31 of the present invention is disposed so that the surface opposite to the outermost layer A is in contact with the inner surface of the lower mold 33b; the outermost layer A (release layer) is in contact with a sealing resin 39 to be described later. To do. For example, when the release film 31 of the present invention has a five-layer structure of outermost layer A / adhesive layer B / base material layer C / adhesive layer B / other outermost layer A ′, What is necessary is just to arrange | position so that outermost layer A 'may contact the inner surface of the lower mold | die 33b; outermost layer A (release layer) may contact the sealing resin 39 mentioned later. And the release film 31 arrange | positioned at the lower metal mold | die 33b is closely_contact | adhered to the inner surface of the lower metal mold | die 33b, for example by operation, such as attraction | suction. The mold temperature at the time of suction may be, for example, the same temperature as at the time of mold molding (first step).

  The cavity 32 for manufacturing the LED package has a hemispherical shape having a diameter of about 0.5 to 3 mm or a similar shape. That is, in comparison with a conventional mold for semiconductor sealing, a mold for manufacturing an LED package has a step (gap) from the parting surface between the upper mold 33a and the lower mold 33b to the deepest part of the cavity 32. ) Is large.

  The upper mold 33a is provided with a substrate 35 on which a plurality of LEDs 37 are arranged (second step).

  Next, as shown in FIG. 4, a sealing resin 39 is filled as a molding material between the upper mold 33 a and the lower mold 33 b via the release film 31. Examples of the sealing resin 39 include thermosetting resins such as silicone resins and epoxy resins. Among these, a resin having transparency is preferable. The release film of the present invention has a high releasability and has a good appearance because it is difficult to cause thickness unevenness due to necking at the molding temperature especially when a silicone resin is used as a sealing resin. Can be obtained.

  After that, as shown in FIG. 5, the LED 37 is placed in the encapsulating resin 39 filled in the mold 33 and the mold is clamped. Although the pressure at the time of mold clamping is not specifically limited, it is about 1.0-10.0 MPa. Moreover, the temperature at the time of mold clamping is not particularly limited, but may be about 110 to 190 ° C.

  Then, the sealing resin 39 is cured under predetermined conditions. The mold temperature at the time of curing can be adjusted according to the type of the sealing resin 39. For example, when a silicone resin is used as the sealing resin 39, the temperature is usually 80 to 160 ° C .; when an epoxy resin is used, the temperature is usually 150 to 200 ° C. (third step).

  Thereafter, as shown in FIG. 6, the mold 33 is opened. Since the release film 31 is excellent in releasability, it can be easily released from the mold 33 (upper mold 33a and lower mold 33b) and the sealing resin 39. Through the above operation, the LED package 40 as shown in FIG. 7 can be obtained (fourth step).

  In the release film of the present invention, the dynamic hardness of the outermost layer A is adjusted to a certain level or less. Therefore, when fixing the release film to the inner surface of the mold in the first process described above, or when performing mold molding in the third process (particularly when performing mold molding in the third process), Since the outermost surface of the release film is uniformly stretched, uneven thickness of the surface of the release film can be suppressed. Furthermore, since the release film of this invention further has the base material layer C, the uneven | corrugated wrinkles by a film extending too much locally can also be suppressed. Accordingly, it is possible to suppress appearance defects due to transfer of unevenness of thickness and irregularities on the surface of the LED package while improving releasability from the resin molded body. Thereby, it is possible to obtain an LED package with high dimensional accuracy that faithfully reflects the inner surface shape of the mold.

  The mold forming method using the release film of the present invention has been described in the example of the LED package manufacturing method. Moreover, the release film of the present invention is not limited to the above-described molding method, and can also be used in a molding method such as transfer molding applied to sealing of a normal semiconductor element.

  In the following, the invention will be described in more detail with reference to examples. These examples do not limit the scope of the present invention.

1. Release Film Material 1) Material for outermost layer A / Material for other outermost layer A ′ (Material A-1)
A copolymer of 4-methyl-1-pentene and diallene 168 (manufactured by Mitsubishi Chemical Corporation, a mixture of α-olefins having 16 and 18 carbon atoms) was produced by a conventional method. The content rate of the structural unit derived from dialen 168 in the copolymer was 6.5% by mass.
(Material A-2)
A copolymer of 4-methyl-1-pentene and 1-decene was produced by a conventional method. The content ratio of the structural unit derived from 1-decene in the copolymer was 2.5% by mass.
(Material A-3)
A copolymer of 78 parts by weight of propylene, 16 parts by weight of ethylene and 6 parts by weight of 1-butene was obtained. 90 parts by weight of the obtained copolymer and 10 parts by weight of homopolypropylene (Prime Polymer F107BV) were melt-kneaded to obtain a thermoplastic elastomer. And 60 weight part material A-1 and 40 weight part thermoplastic elastomer were knead | mixed with a twin-screw extruder at 260 degreeC, and the mixture was obtained.

2) Material for Adhesive Layer B Synthesis of Modified 4-Methyl-1-pentene Copolymer 4-Methyl-1-pentene and Dialene 168 (Mitsubishi Chemical Corporation, Mixture of C16 and C18 α-Olefin) (The content ratio of the structural unit derived from Dialene 168 is 6.5% by mass) by a conventional method.

  98.8 parts by weight of the copolymer, 1 part by weight of maleic anhydride, and 0.2 parts by weight of 2,5-dimethyl-2,5-di (t-butylperoxy) hexane as the organic peroxide. And mixed with a Henschel mixer. The obtained mixture was kneaded with a twin screw extruder at a temperature of 280 ° C. to obtain a modified 4-methyl-1-pentene copolymer graft-modified with maleic anhydride. The graft ratio of the resulting modified 4-methyl-1-pentene copolymer was 0.9% by mass.

Preparation of Adhesive Layer B Material 25 parts by weight of the modified 4-methyl-1-pentene copolymer, 50 parts by weight of 4-methyl-1-pentene and diallene 168 (Mitsubishi Chemical, carbon numbers 16 and 18) (A mixture of α-olefins) and a copolymer (the content ratio of the structural unit derived from dialne 168 is 6.5% by mass), 25 parts by mass of 1-butene copolymer, and 0.10 parts by mass of a stabilizer. Irganox 1010 (manufactured by BASF Corporation) and 0.03 parts by mass of calcium stearate (manufactured by NOF Corporation) were mixed by rotating at a low speed for 3 minutes using a Henschel mixer. The obtained mixture was melt-kneaded at 280 ° C. using a twin-screw extruder to obtain an adhesive layer B material.

3) Material for base material layer C (Material C-1)
Polyamide 6 (manufactured by Ube Industries, trade name: 1030B, melting temperature: 220 ° C.) was prepared.
(Material C-2)
A polyester elastomer (manufactured by Toray DuPont, trade name Hytrel 4777, melting point 200 ° C.) was prepared.
(Material C-3)
Polyamide 66 (manufactured by DuPont, trade name Zytel® 45HSB, melting temperature 262 ° C.) was prepared.

2. Production and Evaluation of Release Film (Example 1)
Each melt of the outermost layer A material A-1, the adhesive layer B material, the base material layer C-1 and the other outermost layer A ′ material A-1 is surfaced using a T-die molding machine. Are coextruded on a mirror-treated cast roll, and A-1 (outermost layer A) / B (adhesive layer B) / C-1 (base material layer C) / B (adhesive layer B) / A-1 ( A release film having a five-layer structure of another outermost layer A ′) was obtained. The cast roll temperature was 20 ° C. The film thickness was adjusted with a touch roll. The thickness of each layer of the release film was A-1 / B / C / B / A-1 = 10/5/20/5/10 μm (total thickness 50 μm).

  The dynamic hardness and RzJIS of the outermost layer A of the obtained release film, the storage elastic modulus of the film, and the tensile breaking stress were measured by the following methods.

[Dynamic hardness]
The maximum indentation depth (D) in the load-unload test mode of the outermost layer A of the release film is measured using a Shimadzu dynamic ultra-small hardness meter DUH-W201S (diamond triangular pan indenter 1115 °). did. The measurement was performed under the conditions of a temperature of 23 ± 2 ° C., a humidity of 50 ± 5%, a test load (P) of 0.50 mN, a load speed of 0.142 mN / sec, and a holding time of 5 sec.

And the value of the maximum indentation depth D (micrometer) was applied to the following formula, and dynamic hardness was computed.
Dynamic hardness = 3.8854 × 0.5 / D ²

[RzJIS]
RzJIS of the surface of the outermost layer A (release layer) in contact with the molded body was measured according to JIS-B0601, using a surface roughness measuring machine (manufactured by Tokyo Seimitsu Co., Ltd., surfcom 130A), measuring length 40 mm, speed 0 Measured at 3 mm / s.

[Storage modulus]
Using a dynamic viscoelastic device RSA-II (manufactured by TA Instruments), tensile mode: vibration frequency 1 Hz, measurement speed: speed of 3 ° C./minute from −80 ° C. to a temperature at which the sample melts and becomes unmeasurable The elastic modulus in the conveyance direction (MD direction) of the release film was measured while raising the temperature at, and the storage elastic modulus E ′ at 120 ° C. was calculated.

[Tensile breaking stress]
1) A release film was cut out as a test piece to obtain a strip-shaped test piece having a width of 10 mm. The longitudinal direction of the strip-shaped test piece was made parallel to the film transport direction.
2) The test piece was held by a tensile tester with a thermostat adjusted to 120 ° C. so that the distance between chucks was 10 mm, and pulled at a tensile speed of 20 mm / min (constant). The tensile fracture stress in the obtained tensile stress-strain curve was determined according to JIS-K7161.

  As a result, the dynamic hardness of the outermost layer A was 3.5. The RzJIS of the surface of the outermost layer A was 0.5 μm, and the RzJIS of the surface of the other outermost layer A ′ was 0.5 μm.

  Further, the following methods were used to evaluate the possibility of vacuum adsorption during molding of the obtained release film and the surface condition (smoothness, gloss, and release film residue) of the obtained resin molded body (lens). . These results are shown in Table 1.

  As shown in FIGS. 8 to 12, a lens was molded with a simple lens evaluation mold. First, as shown in FIG. 8, 100 hemispherical holes having a radius of 1.25 mm and 300 hemispherical holes having a radius of 0.9 mm are arranged on the inner surface of the mold at equal intervals. A mold 64 was prepared. Next, the release film 67 was disposed on the inner surface of the lower mold 64 and fixed with the outer frame 65. Next, as shown in FIG. 9, evacuation was performed from a slit portion (not shown) processed on the side surface portion of the mold, and the release film 67 was made to follow the lens shape of the lower mold 64. The mold temperature during evacuation was 120 ° C.

1) Whether or not vacuum suction is possible As described above, when fixing the release film 67 to the lower mold 64, vacuuming is performed from the slit portion on the side surface of the lower mold 64 so that the release film 67 follows the inner surface of the mold ( (See FIG. 9). At this time, if the mechanical strength of the release film 67 is low, the release film 67 is broken and cannot be vacuum-sucked. Therefore, the presence or absence of tearing of the release film when the release film 67 is vacuum-adsorbed on the inner surface of the mold and followed is evaluated according to the following criteria.
○: Vacuum adsorption is possible without breaking the release film ×: Release film is broken and vacuum adsorption is impossible

  On the other hand, a stainless steel plate 62 (thickness: 1 mm) to which a polyimide tape (thickness: 50 microns) was attached was disposed on the upper mold 61. The planar dimension of the stainless steel plate 62 was 200 × 78 mm; the planar dimension of the release film 67 was 200 × 300 mm; and the planar dimension of the lower mold 64 was 46 × 88 mm.

  Next, as shown in FIG. 10, 1.4 mL of a silicone resin (OE6631 (phenyl) manufactured by Toray Dow Corning) as a sealing resin 63 was measured and injected onto the release film 67 with a syringe.

Next, as shown in FIG. 11, it was compressed in the vertical direction using a 20t hydraulic molding machine (manufactured by Toho Machinery Co., Ltd., not shown). The compression conditions were a temperature of 120 ° C., a pressure of 91 kgf / cm ² (3 MPa), and a compression time of 5 minutes. By this compression, the release film 67 is stretched following the shape of the hole of the lower mold 64, and the liquid silicone resin enters the holes of the release film 67 formed by stretching, and is heated and cured. A hemispherical lens made of silicone resin was molded by the reaction.

  Next, as shown in FIG. 12, the mold was released and the release film 67 was peeled off, and then the surface state of the molded lens 88 was taken out. Then, the surface state (smoothness, glossiness, and release film residue) of the obtained lens 88 was evaluated using an optical microscope (Keyence Microscope VHX-1000 / 1100).

2) Smoothness of lens surface The presence or absence of wrinkles on the obtained lens surface was observed with an optical microscope (100 times).
○: Wrinkles are not observed ×: Wrinkles are observed

3) Glossiness of lens surface It was observed with an optical microscope (100 times) whether or not the obtained lens surface was smooth.
○: The surface is smooth and transparent. ×: The surface is mat-like and not transparent.

4) Releasability (presence or absence of release film residue on lens surface)
The surface of the obtained lens (100 pieces) having a radius of 1.25 mm was observed with an optical microscope (magnification 100 times), and the presence or absence of a release film residue was evaluated.
○: No film residue on lens Δ: 1 to 50 out of 100 film residues on lens ×: 51 to 100 out of 100 film residues on lens

(Example 2)
A release film was obtained in the same manner as in Example 1 except that the temperature of the cast roll was changed to 60 ° C. The dynamic hardness of the outermost layer A (release layer) was 4.6. A lens was molded in the same manner as in Example 1 using the obtained release film, and evaluated.

(Example 3)
A release film was obtained in the same manner as in Example 2 except that the material C-1 of the base material layer C was changed to the material C-2. RzJIS of the outermost layer A and the surface opposite to the outermost layer A (the surface of the outermost layer A ′) was 1.0 μm. Using the obtained release film, lens molding was carried out in the same manner as in Example 1 for evaluation.

(Comparative Example 1)
Example 2 except that A-2 was used as the material for the outermost layer A, C-3 was used as the material for the base layer, and A-2 was used as the material for the other outermost layer A ′, and the layer thickness was changed. A release film having a five-layer structure of A-2 / B / C-3 / B / A-2 was obtained. The thickness of each layer of the release film was A-2 / B / C-3 / B / A-2 = 5/3/22/3/5 μm (total thickness 38 μm).

  The dynamic hardness of the outermost layer A (release layer) of the obtained release film was 9.6. Further, the RzJIS of the surface of the outermost layer A (release layer) of the release film was 0.5 μm, and the RzJIS of the surface of the other outermost layer A ′ was 8.0 μm. Furthermore, a lens was molded in the same manner as in Example 1 using the obtained release film and evaluated.

(Comparative Example 2)
Comparative Example 1 except that the surface roughness of the cast roll was adjusted so that the RzJIS of the outermost layer A (release layer) of the release film was 10 μm and the RzJIS of the surface of the other outermost layer A ′ was 12 μm. In the same manner, a release film was obtained. A lens was molded in the same manner as in Example 1 using the obtained release film, and evaluated.

(Comparative Example 3)
Comparative Example 1 except that the surface roughness of the cast roll was adjusted so that the RzJIS of the outermost layer A (release layer) of the release film was 30 μm and the RzJIS of the surface of the other outermost layer A ′ was 25 μm. In the same manner, a release film was obtained. A lens was molded in the same manner as in Example 1 using the obtained release film, and evaluated.

(Comparative Example 4)
A single-layer release film was obtained in the same manner as in Example 2 except that only the outermost layer A material A-1 was used. A lens was molded in the same manner as in Example 1 using the obtained release film, and evaluated.

(Comparative Example 5)
A single layer release film was obtained in the same manner as Comparative Example 4 except that only the outermost layer A material A-3 was used. A lens was molded in the same manner as in Example 1 using the obtained release film, and evaluated.

The evaluation results of Examples 1 to 3 and Comparative Examples 1 to 5 are summarized in Table 1.

  As shown in Table 1, the release films of Examples 1 to 3 have a storage elastic modulus and tensile rupture stress of a certain level or more, and the dynamics of the outermost layer A is higher than the release films of Comparative Examples 1 to 3. It can be seen that the hardness is low. Thereby, the release films of Examples 1 to 3 are superior to the release films of Comparative Examples 1 to 3 and have good lens surface smoothness without causing breakage during vacuum adsorption. I understand that.

  From this, it can be seen that when the dynamic hardness of the outermost layer A in contact with the resin molded body of the release film is low to some extent, the mold release property is high and the appearance of the resulting resin molded body is also good. The low dynamic hardness of the outermost layer A indicates that the crystallinity of the surface of the outermost layer A is low. In other words, it is generally known that when at least the outermost layer A of the film has a high degree of crystallinity, the releasability is good. On the contrary, the release film of the present invention has improved release properties by reducing the crystallinity of the surface of the outermost layer A.

  Moreover, since the release films of Examples 1 to 3 have a small RzJIS of the outermost layer A in contact with the resin molded product, it can be seen that the gloss of the lens surface is also good.

  It can be seen that the release films of Comparative Examples 1 to 3 have low releasability with the sealing resin, and many film residues remain on the lens surface. It can also be seen that radial wrinkles are formed on the lens surface, and the smoothness of the lens surface is low. It is considered that the radial wrinkles are mainly caused by the high mechanical strength (storage modulus) of the release film. Moreover, it turns out that the glossiness of the lens surface is low in the release film of Comparative Examples 1-3. This is considered to be because RzJIS of the outermost layer A is large.

  It can be seen that the release film of Comparative Example 4 has low lens surface smoothness. This is because the release film of Comparative Example 4 does not have the base material layer C, and therefore has a yield point. Therefore, it is considered that the release film of Comparative Example 4 stretched and deformed non-uniformly when being fixed to the mold or when the mold was formed, and excessively stretched locally, so that uneven wrinkles were remarkably generated. Furthermore, although the release film of Comparative Example 5 has low mechanical strength, the followability to the mold is good, but when the release film is vacuum-adsorbed in the mold, the release film is used under these conditions. Was broken and could not be vacuum-adsorbed.

  Since the film of the present invention can provide a resin molded article having excellent releasability and good appearance, it can be widely used as various release films. In particular, the release film of the present invention is preferably used for molding using a mold having a complicated shape for producing a semiconductor, an LED encapsulant (LED package) and the like.

10, 29, 31, 67 Release film 11 Base layer 13 Adhesive layer 15 Outermost layer 15 'Other outermost layer 20 Film production equipment 21a Dice 21b Feed block 21b1, 21b2, 21b3, 21b4 Conduit 23 Cast roll 25 Touch roll 27 Roll 32, 66 Cavity 33 Mold 33a, 61 Upper mold 33b, 64 Lower mold 35 Substrate 37 LED
39, 63 Sealing resin 40 LED package 62 Stainless steel plate 65 Outer frame 88 Lens (molded body)

Claims (10)

A base material layer C;
The content of 4-methyl-1-pentene and viewed contains as a main component a copolymer of the 4-methyl-1-pentene 1 except carbon number 16 to 20 of the α- olefin compound other than the copolymer The outermost layer A is less than 10 parts by weight with respect to 100 parts by weight of the copolymer;
An adhesive layer B disposed between the base material layer C and the outermost layer A and bonding them;
Including
The outermost layer A is a release layer;
The content ratio of the structural unit derived from an α-olefin having 16 to 20 carbon atoms other than the 4-methyl-1-pentene 1 in the copolymer is 5% by mass or more,
When the 10-point average roughness RzJIS of the surface of the outermost layer A is 0 μm or more and 1.5 μm or less, and the maximum indentation depth measured at 23 ° C. is D (μm), it is defined by the following formula: The mold release film for LED sealing bodies whose dynamic hardness of the said outermost layer A is 0.5-8.0.
Dynamic hardness = 3.8854 × 0.5 / D ² 2. The LED sealing body according to claim 1 , wherein a ten-point average roughness RzJIS of a surface opposite to the outermost layer A of the mold release film for the LED sealing body is 0 μm or more and 1.5 μm or less. Mold release film. The mold release film for LED sealing bodies of Claim 1 or 2 whose content rate of the structural unit derived from 4-methyl-1- pentene in the said copolymer is 93 mass% or more. The base material layer C;
Other outermost layer A ′ containing the outermost layer A and the copolymer, sandwiching the base material layer C;
Wherein the 'adhesive layer B that is bonded with the said base layer C' and the outermost layer A wherein the adhesive layer adhering the base layer C B and the other outermost layer A,
The mold release film for LED sealing bodies as described in any one of Claims 1-3 containing this. The said base material layer C is a metal mold release film for LED sealing bodies as described in any one of Claims 1-4 containing a polyamide resin. The said adhesion layer B is a metal mold release film for LED sealing bodies as described in any one of Claims 1-5 containing a modified | denatured 4-methyl- 1-pentene copolymer. The base layer C comprises a polyamide 6, LED encapsulant mold release film according to any one of claims 1-6. Tensile breaking stress at 120 ° C. is less than 4.0 MPa 40 MPa, LED encapsulant mold release film according to any one of claims 1-7. The mold release film for LED sealing bodies according to any one of claims 1 to 8, wherein a storage elastic modulus E 'at 120 ° C is 30 MPa or more and 200 MPa or less. Step a sealed LED die release film according to any one of claims 1 to 9 in which the surface opposite to the outermost layer A of the release film is placed in contact with the inner surface of the mold When,
Placing the LED mounting substrate in the mold; and
Filling the mold with a sealing resin, clamping the mold, and curing the sealing resin to obtain an LED sealing body;
And a step of peeling the obtained LED sealing body from the release film.

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