WO2019225525A1

WO2019225525A1 - Release film for semiconductor sealing process and method for manufacturing electronic component using same

Info

Publication number: WO2019225525A1
Application number: PCT/JP2019/019825
Authority: WO
Inventors: 奬野々下; 齊藤　岳史; 純平藤原
Original assignee: デンカ株式会社
Priority date: 2018-05-22
Filing date: 2019-05-20
Publication date: 2019-11-28
Also published as: TW202012140A; JP2021130197A

Abstract

[Problem] To provide a release film which is for a semiconductor sealing process and which has at least a certain level of releasability and mold followability, reduces the occurrence of wrinkles even in a high-temperature sealing process, and can be used at low cost. [Solution] This release film for a semiconductor sealing process has a surface layer (A) and a heat-resistant resin layer (B), wherein the surface layer (A) includes a 4-methylpentene-1 polymer, and the release film for a semiconductor sealing process has a storage elastic modulus (E'1) of 250-1500 MPa at 180 °C.

Description

Release film for semiconductor sealing process and method of manufacturing electronic component using the same

The present invention relates to a release film for a semiconductor sealing process and an electronic component manufacturing method using the same.

In recent years, in the process of sealing a semiconductor chip with a resin, a release film is disposed between the inner surface of the mold and the semiconductor chip in order to obtain a release property between the sealing resin and the mold after the resin is cured. The method to be taken is taken.

As such a release film, a tetrafluoroethylene-ethylene copolymer (ETFE) resin film (for example, Patent Document 1) excellent in release properties and heat resistance is mainly used. However, these release films have a problem that a thermal degradation product adheres to the inner surface of the mold and contaminates the mold, which causes a poor appearance and a high unit price.

On the other hand, a polystyrene resin release film having a low unit price has also been proposed (for example, Patent Document 2). However, the release film of Patent Document 2 is inferior in heat resistance and has a problem that wrinkles are easily generated in a sealing process at a high temperature.

JP 2001-310336 A Japanese Patent Laid-Open No. 2015-021017

The present invention has been made in view of such circumstances, has a mold release property and mold followability that exceed a certain level, is less likely to cause wrinkles in a sealing process at a high temperature, and is low in cost. It aims at providing the release film for semiconductor sealing processes which can be used.

That is, the present inventor has examined various resins, and as a result, in the release film for semiconductor encapsulation process having the surface layer (A) and the heat-resistant resin layer (B), the surface layer (A) is 4-methyl. -By including 180-degrees storage elastic modulus (E'1) of the above-mentioned release film for semiconductor encapsulation process, including pentene-1 polymer, a predetermined or higher mold release property and mold follow-up Thus, the present invention has been completed by finding that the generation of wrinkles is small even in a sealing process at a high temperature.

The present invention for solving the above-described problems is constituted as follows.
(1) A release film for a semiconductor sealing process having a surface layer (A) and a heat resistant resin layer (B),
The surface layer (A) comprises 4-methyl-pentene-1 polymer;
The mold release film for semiconductor sealing processes whose 180 degreeC storage elastic modulus (E'1) of the said mold release film for semiconductor sealing processes is 250 MPa or more and 1500 MPa or less.
(2) A release film for a semiconductor sealing process having a surface layer (A) and a heat-resistant resin layer (B),
The surface layer (A) comprises 4-methyl-pentene-1 polymer;
A release film for a semiconductor encapsulation process, wherein the heat-resistant resin layer (B) has a storage elastic modulus (E′1) at 180 ° C. of 500 MPa to 2000 MPa.
(3) The release film for semiconductor encapsulation process according to (1) or (2), wherein the heat resistant resin layer (B) contains at least one resin selected from polyether sulfone, polyphenyl sulfone, and polyarylate. .
(4) The strength at 180 ° C. (F) of the release film for semiconductor encapsulation process calculated from the following formula 1 is 5000 N / mm or more and 130,000 N / mm or less, (1) to (3) Release film for semiconductor sealing process.
180 ° C. strength (F) = 180 ° C. storage elastic modulus (E′1) × thickness (mm) Formula 1
(5) The storage elastic modulus (E′1) at 180 ° C. of the release film for semiconductor encapsulation process is 0.5 to 1.0 times the storage elastic modulus (E′2) at 23 ° C., The release film for semiconductor sealing processes in any one of Claim (1), (3) or (4).
(6) The thickness of the release film for semiconductor encapsulation process is 20 μm or more and 125 μm or less, and the thickness of the heat-resistant resin layer (B) is 20% of the thickness of the release film for semiconductor encapsulation process. The release film for a semiconductor sealing process according to any one of (1) to (5), which is 90% or less.
(7) The release film for a semiconductor encapsulation process according to any one of (1) to (6), which has an adhesive layer (C) between the surface layer (A) and the heat-resistant resin layer (B).
(8) An attachment step of attaching the release film for semiconductor encapsulation process according to any one of (1) to (7) to a sealing device;
A sealing step for sealing the release film for semiconductor sealing process and the semiconductor arranged on the substrate with a resin;
A mold release step of peeling off the mold release film for semiconductor sealing process.

According to the present invention, a mold release for a semiconductor sealing process that has a certain level of mold release property and mold followability, is less likely to cause wrinkles in a high temperature sealing process, and can be used at low cost. A film can be provided.

Hereinafter, various embodiments of a release film for a semiconductor sealing process will be described, and then a method for manufacturing a release film for a semiconductor sealing process and a method for manufacturing an electronic component will be described. When the description is applicable to other embodiments, the description is omitted in the other embodiments.

[First embodiment]
The mold release film for semiconductor sealing processes which concerns on 1st embodiment of this invention is a mold release film for semiconductor sealing processes which has a surface layer (A) and a heat-resistant resin layer (B), Comprising: The surface layer ( A) includes 4-methyl-pentene-1 polymer, and the release film for semiconductor encapsulation process has a storage elastic modulus (E′1) at 180 ° C. of 250 MPa to 1500 MPa. It is a film.

(Surface layer (A))
The 4-methyl-pentene-1 polymer contained in the surface layer (A) may be a homopolymer of 4-methyl-pentene-1 or a copolymer with other resins. Also good. Examples of the resin copolymerized with 4-methyl-pentene-1 include olefins having 2 to 20 carbon atoms. Examples of olefins having 2 to 20 carbon atoms include ethylene, propylene, 1-butene, 1-hexene, 1-heptene, 1-octene, 1-decene, 1-tetradecene, 1-hexadecene, 1-heptadecene, -Octadecene, 1-eicosene and the like are included. These olefins may be used alone or in combination of two or more.
In one embodiment of the present invention, when the 4-methyl-pentene-1 polymer is a copolymer, the proportion of structural units derived from 4-methyl-pentene-1 is 90 to 99% by mass, otherwise The proportion of structural units derived from the resin is preferably 1 to 10% by mass.
The 4-methyl-pentene-1 polymer can be produced by a known method. For example, it can be produced by a method using a known catalyst such as a Ziegler-Natta catalyst or a metallocene catalyst, but may be a commercially available copolymer such as TPX manufactured by Mitsui Chemicals, Inc.
In one embodiment of the present invention, the storage elastic modulus E ′ at 180 ° C. of the resin constituting the surface layer (A) is 5 MPa or more and 50 MPa or less. By setting the storage elastic modulus E ′ at 180 ° C. to 5 MPa or more, it is possible to suppress the generation of wrinkles in the sealing process because the release film for the semiconductor sealing process becomes too soft. Moreover, by setting the storage elastic modulus E ′ at 180 ° C. to 50 MPa or less, it is possible to prevent the mold followability from being deteriorated because the release film for a semiconductor sealing process is too hard.
The thickness of the surface layer (A) is not particularly limited, but is 1 to 100 μm, preferably 3 to 75 μm, more preferably 10 to 40 μm.
In one embodiment of the present invention, the thickness of the surface layer (A) is 10% or more and 80% or less, preferably 20% or more and 70% or less of the thickness of the release film for semiconductor encapsulation process. More preferably, it is 30% or more and 60% or less.
The surface of the surface layer (A) may be mirror-finished as necessary. The method of applying a mirror finish to the surface of the surface layer (A) is not particularly limited, but a general method such as pressure bonding of a mirror-finished roll can be employed. Moreover, the surface of the surface layer (A) may have an uneven shape. There is no particular limitation on the method for imparting the uneven shape to the surface of the surface layer (A), but a general method such as embossing can be employed.

(Heat-resistant resin layer (B))
The resin constituting the heat-resistant resin layer in this embodiment is a 180 ° C. of the release film for semiconductor encapsulation process in the release film for semiconductor encapsulation process having the surface layer (A) and the heat-resistant resin layer (B). There is no particular limitation as long as the storage elastic modulus (E′1) is 250 MPa or more and 1500 MPa or less. For example, one or more kinds of resins selected from polyether sulfone, polyphenyl sulfone, polyarylate, polyetherimide, and thermoplastic polyimide can be used.
The thickness of the heat resistant resin layer (B) is not particularly limited, but is 1 to 100 μm, preferably 3 to 75 μm, and more preferably 10 to 25 μm.
In one embodiment of the present invention, the thickness of the heat resistant resin layer (B) is 20% or more and 90% or less, preferably 30% or more and 80% or less of the thickness of the release film for semiconductor sealing process. Yes, more preferably 40% or more and 70% or less.
The surface of the heat resistant resin layer (B) may be mirror-finished as necessary. The method for applying a mirror finish to the surface of the heat-resistant resin layer (B) is not particularly limited, but a general method such as pressure bonding of a mirror-finished roll can be employed. Moreover, the surface of the heat resistant resin layer (B) may have an uneven shape. There is no particular limitation on the method for imparting the uneven shape to the surface of the heat-resistant resin layer (B), but a general method such as embossing can be adopted.

(Other)
In one embodiment of the present invention, an adhesive layer (C) may be provided between the surface layer (A) and the heat resistant resin layer (B). The adhesive layer is particularly capable of adhering the surface layer (A) and the heat-resistant resin layer (B) and does not peel off even in the resin sealing step or the release step, and does not hinder the effects of the present invention. Although not limited, for example, an epoxy-based thermosetting adhesive or a urethane-based adhesive can be used. The thickness of the adhesive layer (C) is not particularly limited, but is 0.5 to 15 μm, preferably 1 to 10 μm, more preferably 2 to 5 μm.
Moreover, each layer in one Embodiment of this invention may contain an additive in the range which does not inhibit the effect of this invention. As long as the effects of the present invention are not impaired, a known additive that can be generally blended may be included, such as a heat resistance stabilizer, a weather resistance stabilizer, a rust inhibitor, a copper damage stabilizer, and an antistatic agent. The content of these additives can be 0.01 to 30 parts by mass with respect to 100 parts by mass of the resin constituting each layer.

(the film)
The storage elastic modulus (E′1) at 180 ° C. of the film in one embodiment of the present invention is 250 MPa or more and 1500 MPa or less, and is useful as a release film for a semiconductor encapsulation process. The storage elastic modulus (E′1) at 180 ° C. of the film in one embodiment of the present invention is preferably 400 MPa to 1400 MPa, more preferably 500 MPa to 1000 MPa.
In one embodiment of the present invention, the 180 ° C. strength (F) of the release film for semiconductor encapsulation process is 5000 N / mm to 130,000 N / mm, preferably 14500 N / mm to 100,000 N / mm, and more Preferably, it is 15500 N / mm or more and 55000 N / mm or less. Further, the strength (F) at 180 ° C. of the release film for semiconductor encapsulation process can be calculated by the method described in Equation 1.
180 ° C. strength (F) = 180 ° C. storage elastic modulus (E′1) × thickness (mm) Formula 1

In one embodiment of the present invention, the storage elastic modulus (E′1) at 180 ° C. of the release film for semiconductor encapsulation process is 0.5 times or more the storage elastic modulus (E′2) at 23 ° C. and 1.0. 2 times or less, preferably 0.55 times or more and 0.9 times or less, more preferably 0.6 times or more and 0.8 times or less. The storage elastic modulus (E′1) at 180 ° C. of the release film for semiconductor encapsulation process is 0.5 times or more the storage elastic modulus (E′2) at 23 ° C. Also in the process, the release film for the semiconductor sealing process does not become too soft, and generation of wrinkles in the sealing process can be suppressed.
In one embodiment of the present invention, the total thickness of the release film for semiconductor encapsulation process is 20 μm or more and 125 μm or less, preferably 20 μm or more and 100 μm or less, more preferably 25 μm or more and 100 μm or less.
In one embodiment of the present invention, the release film for a semiconductor encapsulation process is a two-layer film composed of a surface layer (A) and a heat resistant resin layer (B), for example, surface layer (A) / heat resistant resin layer. A three-layer film composed of (B) / surface layer (A) may be used, and an adhesive layer (C) may be provided between the surface layer (A) and the heat-resistant resin layer (B).
In one embodiment of the present invention, the release film for a semiconductor encapsulation process may be uniaxially or biaxially stretched, thereby increasing the film strength of the film.

[Second Embodiment]
The mold release film for semiconductor sealing processes which concerns on 2nd embodiment of this invention is a mold release film for semiconductor sealing processes which has a surface layer (A) and a heat resistant resin layer (B), Comprising: The said surface layer ( A release film for semiconductor encapsulation process, wherein A) contains 4-methyl-pentene-1 polymer, and the heat-resistant resin layer (B) has a storage elastic modulus (E′1) at 180 ° C. of 500 MPa to 2000 MPa. It is.

Since the material and thickness of the surface layer (A) and the heat-resistant resin layer (B), other components, films, and the like are the same as those in the first embodiment, description thereof is omitted.
In this embodiment, the storage elastic modulus (E′1) at 180 ° C. of the resin constituting the heat resistant resin layer (B) is 500 MPa or more and 2000 MPa or less, preferably 1000 MPa or more and 1700 MPa or less, more preferably 1100 MPa or more. 1600 MPa or less. By setting the storage elastic modulus E ′ at 180 ° C. to 500 MPa or more, not only can the release film for the semiconductor sealing process become too soft and the generation of wrinkles in the sealing process can be suppressed, but also heat resistance Even when the resin layer (B) is in contact with the mold, it is possible to ensure releasability with respect to the mold. Moreover, by setting the storage elastic modulus E ′ at 180 ° C. to 2000 MPa or less, it is possible to suppress the mold followability from being lowered due to the release film for the semiconductor sealing process being too hard.

[Method for producing release film for semiconductor encapsulation process]
In one embodiment of the present invention, the release film for a semiconductor encapsulation process can be manufactured by any method. For example, a surface layer (A) and a heat-resistant resin layer (B) are coextruded and laminated to produce a release film for a semiconductor sealing process (coextrusion forming method), or a surface layer (A ) And a film to be a heat resistant resin layer (B), and laminating these films via an adhesive layer to produce a release film for a semiconductor encapsulation process (Adhesion method).
The melt extrusion means in the coextrusion forming method is not particularly limited. For example, an extruder having a T-type die or an inflation type die can be used. In the adhesion method, means for applying the adhesive layer is not particularly limited, and various coaters such as a roll coater, a die coater, and a spray coater can be used.

[Method of manufacturing electronic parts]
In this embodiment, an electronic component using a release film for a semiconductor sealing process includes an attaching step for attaching the release film for a semiconductor sealing process to a sealing device, and the release film for the semiconductor sealing process and the substrate. It is manufactured by a method having a sealing step of sealing a semiconductor arranged in a resin with a resin and a release step of peeling the release film for semiconductor sealing process.
In one embodiment of the present invention, the electronic component is manufactured by the following method. First, a release film for a semiconductor sealing process is supplied into a mold. Next, a release film for a semiconductor sealing process is disposed on the inner surface of the upper mold. Next, a semiconductor to be resin-sealed is placed in the mold, and a sealing resin material is set and the mold is clamped. Next, a sealing resin material is injected into the mold under predetermined heating and pressure conditions. The temperature of the mold at this time is generally 150 to 180 ° C. However, when the release film for semiconductor encapsulation process of the present embodiment is used, at a higher mold temperature (for example, 180 to 200 ° C.). Even so, it has a certain level of releasability and mold followability, and less wrinkles, so it not only expands the choice of sealing resin material, but also shortens the sealing process time. . The molding pressure is, for example, 7 to 12 MPa, and the molding time is, for example, about 1 to 5 minutes. After holding for a certain period of time, the upper mold and the lower mold are opened, and the resin-sealed semiconductor and release film are released simultaneously or sequentially. A desired electronic component can be obtained by removing an excess resin portion of the obtained semiconductor.
The release film of the present invention is not limited to the step of resin-sealing a semiconductor element, but can be preferably used in a step of molding and releasing various resins using a mold.

EXAMPLES The present invention will be described more specifically with reference to the following examples. However, the interpretation of the present invention is not limited by these examples.

[material]
In the examples and comparative examples, the following materials were used.
(Surface layer (A))
(A-1) Polymethylpentene resin film, “DX845” manufactured by Mitsui Chemicals, Inc.
(A-2) Polymethylpentene resin film, “MX004” manufactured by Mitsui Chemicals, Inc.
(A-3) Polyethylene resin film, “Nipolon Hard 6060” manufactured by Tosoh Corporation
(Heat-resistant resin layer (B))
(B-1) Polyether sulfone resin film, “Sumika Excel PES4800G” manufactured by Sumitomo Chemical Co., Ltd.
(B-2) Polyphenylsulfone resin film, “Ultrason P3010” manufactured by BASF
(B-3) Polyarylate resin film, “U Polymer U-100” manufactured by Unitika Ltd., Tg 193 ° C.
(B-4) Polyetherimide resin film, “Ultem VH1003-1000” manufactured by Sabic
(B-5) Polycarbonate resin film, “K1300” manufactured by Teijin Limited
(B-6) Polyethylene terephthalate resin film, “S10” manufactured by Toray Industries, Inc.
(Adhesive layer (C))
(C-1) Epoxy thermosetting adhesive, 1: 1 mixture of “MAXIVE M-100” and “MAXIVE C93-E” manufactured by Mitsubishi Gas Chemical Company, Inc.

The storage elastic modulus (tensile viscoelasticity) of the heat-resistant resin layer (B) and the release film for semiconductor encapsulation process was measured under the following conditions.
Apparatus: Dynamic viscoelastic apparatus RSA-G2 (TA Instruments)
Measurement conditions: tensile mode,
Vibration frequency: 1Hz
Measurement temperature: Temperature from 23 ° C. to 5 ° C./min, temperature until the sample melts and becomes impossible to measure Measurement direction: Longitudinal direction of film (film transport direction)
Evaluation item: Storage elastic modulus E′1 at 180 ° C.
Storage elastic modulus E'2 at 23 ° C

[Example 1]
As the surface layer (A), a polymethylpentene resin (DX845) manufactured by Mitsui Chemicals was melt-extruded at 300 ° C. to obtain a polymethylpentene film having a thickness of 23 μm. As the heat-resistant resin layer (B), polyethersulfone (Sumika Excel PES4800G) manufactured by Sumitomo Chemical Co., Ltd. was melt extruded at 370 ° C. to obtain a polyethersulfone film having a thickness of 23 μm. An epoxy thermosetting adhesive (MAXIVE) manufactured by Mitsubishi Gas Chemical Co., Ltd. was applied to one side of the polyether sulfone film so that the coating thickness after drying was 4 μm, thereby forming an adhesive layer. A polymethylpentene film was laminated on this adhesive layer with a dry laminating apparatus to obtain a release film for a semiconductor sealing process having a thickness of 50 μm.

[Examples 2 to 17, Comparative Examples 1 to 4]
A release film for a semiconductor encapsulation process was produced in the same manner as in Example 1 except that the surface layer (A), the heat resistant resin layer (B), and the adhesive layer (C) were as described in Table 1. In addition, about Example 10, it produced by the co-extrusion method and was set as the release film for semiconductor sealing processes of 2 layer structure and thickness of 50 micrometers. Comparative Examples 3 and 4 were each a single layer structure and a release film for a semiconductor encapsulation process having a thickness of 50 μm.

The obtained release film for semiconductor encapsulation process was vacuum-adsorbed to the upper parting surface using a transfer mold apparatus GTM-S MS manufactured by Apic Yamada. Next, the lead frame on which the semiconductor chip with the adhesive tape attached was placed in the lower mold and the mold was clamped. At this time, the mold temperature (molding temperature) was 180 ° C., the molding pressure was 8 MPa, and the molding time was 3 minutes. Then, after sealing the lead frame on which the semiconductor chip was mounted with a sealing resin, the release film for semiconductor sealing process in contact with the resin sealing was released.

The following evaluations were performed on the release films for semiconductor encapsulation process obtained in Examples and Comparative Examples, and the results are shown in Table 1.

[Evaluation]
(Mold followability)
The mold following property of the release film for semiconductor encapsulation process was evaluated according to the following criteria.
3: There is no resin chipping in the semiconductor package 2: There was a resin chipping at the edge part of the semiconductor package 1: The release film for the semiconductor sealing process did not follow the mold and could not be vacuum-adsorbed

(Tear / Tear)
The mold release film for semiconductor sealing process and the state of wrinkles on the resin sealing surface of the semiconductor package were evaluated according to the following criteria.
3: The mold release film for the semiconductor encapsulation process has no wrinkles or tears. 2: The mold release film for the semiconductor encapsulation process has slight wrinkles but no tears. 1: The mold release for the semiconductor encapsulation process The film has numerous folds or tears

(Releasability)
The releasability of the release film for semiconductor sealing process was evaluated according to the following criteria.
3: Release film for semiconductor encapsulation process peels off simultaneously with mold release 2: Release film for semiconductor encapsulation process peels off within 10 seconds after mold release 1: Release mold for semiconductor encapsulation process The film is in close contact with the resin sealing surface of the semiconductor package and does not peel off

Claims

A release film for a semiconductor sealing process having a surface layer (A) and a heat resistant resin layer (B),
The surface layer (A) comprises 4-methyl-pentene-1 polymer;
The mold release film for semiconductor sealing processes whose 180 degreeC storage elastic modulus (E'1) of the said mold release film for semiconductor sealing processes is 250 MPa or more and 1500 MPa or less.
A release film for a semiconductor sealing process having a surface layer (A) and a heat resistant resin layer (B),
The surface layer (A) comprises 4-methyl-pentene-1 polymer;
A release film for a semiconductor encapsulation process, wherein the heat-resistant resin layer (B) has a storage elastic modulus (E′1) at 180 ° C. of 500 MPa to 2000 MPa.
The release film for semiconductor encapsulation processes according to claim 1 or 2, wherein the heat-resistant resin layer (B) contains at least one resin selected from polyether sulfone, polyphenyl sulfone, and polyarylate.
The semiconductor encapsulation according to any one of claims 1 to 3, wherein the strength (F) at 180 ° C of the release film for semiconductor encapsulation process calculated from the following formula 1 is 5000 N / mm or more and 130000 N / mm or less. Release film for stop process.
180 ° C. strength (F) = 180 ° C. storage elastic modulus (E′1) × thickness (mm) Formula 1
2. The storage elastic modulus (E′1) at 180 ° C. of the release film for semiconductor encapsulation process is 0.5 to 1.0 times the storage elastic modulus (E′2) at 23 ° C. 2. Or the release film for semiconductor sealing processes as described in any one of 3 or 4.
The thickness of the release film for semiconductor encapsulation process is 20 μm or more and 125 μm or less, and the thickness of the heat-resistant resin layer (B) is 20% or more and 90% of the thickness of the release film for semiconductor encapsulation process. The release film for a semiconductor encapsulation process according to any one of claims 1 to 5, which is as follows.
The release film for a semiconductor encapsulation process according to any one of claims 1 to 6, further comprising an adhesive layer (C) between the surface layer (A) and the heat-resistant resin layer (B).
An attaching step of attaching the release film for semiconductor encapsulation process according to any one of claims 1 to 7 to a sealing device;
A sealing step for sealing the release film for semiconductor sealing process and the semiconductor arranged on the substrate with a resin;
A mold release step of peeling off the mold release film for semiconductor sealing process.