KR102476428B1 - Mold release film and method for manufacturing semiconductor package - Google Patents

Abstract

Provision of a release film having excellent antistatic action and excellent transparency even in a high-temperature environment and a method for manufacturing a semiconductor package using the release film.
In the manufacture of a semiconductor package in which a semiconductor element is placed in a mold and sealed with a curable resin to form a resin encapsulation, a release film disposed on a surface in contact with the curable resin of the mold, which has a release property in contact with the curable resin during formation of the resin encapsulation. A substrate 2 (but not containing an antistatic agent) and an antistatic layer 3 in contact with the mold when forming the resin encapsulation portion, the antistatic layer 3 made of a conductive polymer and a conductive metal oxide A release film containing at least one antistatic agent selected from the group and having a total light transmittance of 80% or more.

Description

Manufacturing method of release film and semiconductor package {MOLD RELEASE FILM AND METHOD FOR MANUFACTURING SEMICONDUCTOR PACKAGE}

In the manufacture of a semiconductor package in which a semiconductor element is placed in a mold and sealed with a curable resin to form a resin encapsulation, a release film disposed on a cavity surface of a mold and a semiconductor package using the release film It relates to a manufacturing method.

Semiconductor elements are usually sealed with resin to block and protect from outside air, and are mounted on a board as a molded product called a package. Curable resins, such as thermosetting resins, such as an epoxy resin, are used for sealing of a semiconductor element. As a method of encapsulating the semiconductor element, for example, a so-called transfer molding method or compression method in which a substrate on which a semiconductor element is mounted is disposed so that the semiconductor element is located at a predetermined location in a cavity of a mold, and a curable resin is filled in the cavity and cured. Molding methods are known.

Conventionally, a package is molded as a package molded product for each element connected through a runner, which is a curable resin flow path. In this case, the improvement of the releasability of the package from the mold is often achieved by adjusting the mold structure, adding a release agent to the curable resin, or the like. On the other hand, packages of the BGA method, the QFN method, and also the wafer level CSP (WL-CSP) method are increasing due to the demand for miniaturization and multi-pin package. In the QFN method, a release film is placed on the cavity surface of the mold to secure standoffs and prevent resin burrs on the terminals, and in the BGA method and WL-CSP method, to improve the releasability of the package from the mold. There are many cases.

In the arrangement of the release film on the cavity surface of the mold, a long release film in a generally overlapping state is unwound from an unwinding roll, supplied onto the mold in a state pulled by the unwinding roll and the take-up roll, and It is carried out by adsorbing on cotton. In recent years, supplying a release film having a short length cut to fit a mold in advance to a mold has also been practiced (Patent Document 1).

As the release film, a resin film is generally used. However, there is a problem that such a release film is easily charged. For example, when a release film wound up in a roll shape is unwound and used, static electricity is generated during peeling of the release film, and the release film is charged. In this case, foreign matter such as dust present in the manufacturing atmosphere adheres to the charged release film, causing abnormal shape of the package (burr generation, foreign material attachment, etc.) or contamination of the mold. In addition, when the charged release film comes into contact with a semiconductor element, there is a possibility that the semiconductor element is destroyed by discharge. In particular, devices employing granular resin as encapsulation devices for semiconductor elements are increasing (for example, Patent Document 2), and shape abnormalities and mold contamination caused by dust generated from granular resin adhering to the release film cannot be ignored. It is becoming.

Further, in recent years, packages in which semiconductor elements are flip-chip bonded together to expose the back surface of the semiconductor elements are increasing in response to requests for thinner packages and improved heat dissipation. This process is called the Molded Underfill (MUF) process. In the MUF process, sealing is performed in a state where the release film and the semiconductor element are in direct contact for protection and masking of the semiconductor element (for example, Patent Document 3). If the release film is easily charged, when the cured curable resin and the release film are peeled off, the release film is charged, followed by discharge, which may destroy the semiconductor element.

As countermeasures for this, (1) before the release film is conveyed to the mold, a method of passing between electrodes to which a high voltage is applied and blowing ionized air to the release film to eliminate static electricity (Patent Document 4), (2) containing carbon black Method for lowering the surface resistance value of the release film (Patent Document 5), (3) Coating an antistatic agent on a substrate constituting the release film, and further coating and crosslinking a crosslinkable acrylic pressure-sensitive adhesive to form a release layer on the release film A method (Patent Document 6) and the like have been proposed. In the method (3), as the antistatic agent, a cationic antistatic agent having a quaternary ammonium salt is preferred because of its excellent antistatic properties.

Japanese Unexamined Patent Publication No. 2009-272398 Japanese Unexamined Patent Publication No. 2008-279599 Japanese Unexamined Patent Publication No. 2013-123063 Japanese Unexamined Patent Publication No. 2000-252309 Japanese Unexamined Patent Publication No. 2002-280403 Japanese Unexamined Patent Publication No. 2005-166904

However, in the method (1), although the release film is neutralized, the risk of dust entrainment by air increases, and since the release film is charged when the release film and the semiconductor element come into contact, charge-discharge during peeling is prevented. can't be prevented

In the method (2), if enough carbon black is contained to sufficiently lower the surface resistance value, the transparency of the release film is lost, making it impossible to visually see the mold through the release film, and carbon black falls off to contaminate the mold. and so on. If visual recognition of the mold beyond the release film is not possible, misalignment of the release film on the mold or adsorption failure associated therewith tends to occur.

In the method (3), there is a problem that the antistatic action of the release film is lost in the encapsulation step (for example, at 180°C).

An object of the present invention is to provide a release film having excellent antistatic action and excellent transparency even under a high temperature environment (for example, 180° C.) and a method for manufacturing a semiconductor package using the release film.

The present invention provides a method for manufacturing a release film and a semiconductor package having the constitutions of the following [1] to [15].

[1] In the manufacture of a semiconductor package in which a semiconductor element is placed in a mold and sealed with a curable resin to form a resin encapsulation, a release film disposed on a surface in contact with the curable resin of the mold,

A releasable substrate in contact with a curable resin when forming a resin encapsulation portion, and an antistatic layer in contact with a mold when forming the resin encapsulation portion,

The antistatic layer contains at least one antistatic agent selected from the group consisting of conductive polymers and conductive metal oxides;

A release film characterized by having a total light transmittance of 80% or more.

[2] The release film according to [1], wherein the film electrification voltage after sealing is 200 V or less as measured by the following measuring method.

(Method of measuring film electrification voltage after sealing)

A 13 cm × 13 cm, 100 μm thick aluminum foil (JIS H4000: 2006 AlN30P) was placed on a 13 cm × 13 cm first stainless steel plate, and a 10 cm × 12 cm, 125 μm thick aluminum foil was placed thereon as a spacer. The center of the polyimide film was cut out to a size of 8 cm × 10 cm, and further, an epoxy resin for semiconductor encapsulation as a curing resin was placed on the cut out portion of the polyimide film, Sumikon EME G770H typeF ver.GR (Sumitomo Bakelite Co., Ltd. prepared) sprinkled with 2.7 g. On top of that, the release film of 13 cm x 13 cm is removed from static electricity in advance, and then the antistatic layer side and the opposite surface are placed in contact with the curable resin, and further 13 cm x 13 cm thereon 2nd stainless steel plate is put on it, and it is set as a sample.

The sample prepared in the above procedure is pressed with a press machine at a temperature of 180 ° C., a pressure of 1 MPa, and a time of 3 minutes, and after taking it out of the press machine, the whole is placed on a hot plate at 180 ° C., and after removing the second stainless steel plate, release The film is peeled off over 5 seconds. Within 5 seconds after that, the electrostatic voltage on the side of the peeled release film that was in contact with the curable resin is measured using a surface electrometer while fixing the distance between the release film and the measurement terminal to 3 cm.

[3] The release film according to [1] or [2], wherein the antistatic layer has a surface resistance value of 10 ¹⁰ Ω/□ or less.

[4] The release film according to any one of [1] to [3], wherein an arithmetic average roughness Ra of the surface on the antistatic layer side is from 0.2 to 2.5 µm.

[5] The release film according to any one of [1] to [4], wherein the antistatic layer has a thickness of 100 to 1,000 nm.

[6] The release film according to any one of [1] to [5], wherein the antistatic layer contains the antistatic agent and a resin binder.

[7] The resin binder is an acrylic resin, silicone resin, urethane resin, polyester resin, polyamide resin, vinyl acetate resin, ethylene-vinyl acetate copolymer, ethylene-vinyl alcohol copolymer, chlorotrifluoroethylene-vinyl The release film according to [6], which is composed of at least one selected from the group consisting of alcohol copolymers and tetrafluoroethylene-vinyl alcohol copolymers.

[8] The release film according to [6] or [7], wherein the content of the antistatic agent is 3 to 50% by mass relative to the resin binder.

[9] The release film according to any one of [1] to [8], wherein the arithmetic mean roughness Ra of the surface on the side of the releasable substrate is from 0.1 to 2.5 µm.

[10] The release film according to any one of [1] to [9], wherein the release substrate has a thickness of 12 to 100 μm.

[11] The release film according to any one of [1] to [10], wherein the releasable substrate is made of a transparent resin body of a single layer or multilayer structure, and a layer constituting at least a surface in contact with the curable resin is made of a releasable transparent resin.

[12] The release film according to [11], wherein the releasable substrate is a single layer structure made of a releasable transparent resin.

[13] The release film according to [11] or [12], wherein the releasable transparent resin is a fluororesin, polymethylpentene, syndiotactic polystyrene, or a silicone resin.

[14] The release film according to [11] or [12], wherein the transparent release resin is an ethylene-tetrafluoroethylene copolymer.

[15] A method for manufacturing a semiconductor package having a semiconductor element and a resin sealing portion made of a cured curable resin for sealing the semiconductor element,

A step of disposing the release film of any one of [1] to [14] on the surface of the mold in contact with the curable resin;

A step of arranging a substrate on which a semiconductor element is mounted in the mold, filling a space in the mold with a curable resin and curing to form a resin encapsulation portion, thereby obtaining an encapsulated body having the substrate on which the semiconductor element is mounted and the resin encapsulation portion;

A method for manufacturing a semiconductor package, comprising a step of releasing the encapsulated body from the mold.

The release film of the present invention has an excellent antistatic action and excellent transparency even under a high temperature environment (for example, 180°C).

1 is a schematic sectional view showing a first embodiment of a release film of the present invention.
Fig. 2 is a schematic cross-sectional view showing a second embodiment of the release film of the present invention.
3 is a schematic cross-sectional view showing an example of a semiconductor package manufactured by the method for manufacturing a semiconductor package of the present invention.
4 is a schematic cross-sectional view showing another example of a semiconductor package manufactured by the method for manufacturing a semiconductor package of the present invention.
5 is a cross-sectional view schematically illustrating steps (α1) to (α3) in the first embodiment of the semiconductor package manufacturing method of the present invention.
Fig. 6 is a cross-sectional view schematically illustrating the step (?4) in the first embodiment of the semiconductor package manufacturing method of the present invention.
Fig. 7 is a cross-sectional view schematically illustrating the step (?4) in the first embodiment of the semiconductor package manufacturing method of the present invention.
8 is a cross-sectional view showing a step (β1) in the second embodiment of the method for manufacturing a semiconductor package of the present invention.
9 is a cross-sectional view showing steps (β2) to (β3) in the second embodiment of the semiconductor package manufacturing method of the present invention.
10 is a cross-sectional view showing a step (β4) in the second embodiment of the method for manufacturing a semiconductor package of the present invention.
11 is a cross-sectional view showing a step (β5) in the second embodiment of the method for manufacturing a semiconductor package of the present invention.

The following definitions of terms apply throughout the scope of this specification and claims.

The "unit" in resin represents the structural unit (monomer unit) which comprises the said resin.

"Fluorine resin" shows a resin containing a fluorine atom in the structure.

The release film of the present invention is a film disposed on the surface of the mold in contact with the curable resin in the manufacture of a semiconductor package in which a semiconductor element is placed in a mold and sealed with a curable resin to form a resin encapsulation portion. The release film of the present invention is disposed so as to cover the cavity surface of a mold having a cavity having a shape corresponding to the shape of the resin encapsulation portion when forming a resin encapsulation portion of a semiconductor package, for example, By disposing between the cavity faces, release from the mold of the obtained semiconductor package is facilitated.

Hereinafter, the details of the release film of this invention are demonstrated.

The release film of the present invention includes a release base material in contact with a curable resin when forming a resin encapsulation portion, and an antistatic layer in contact with a mold when forming the resin encapsulation portion.

The releasable substrate is made of a transparent resin body of a single layer structure or multilayer structure, and at least a layer constituting a surface in contact with the curable resin is made of the releasable transparent resin. In the present invention, "releasable transparent resin" refers to a resin having a release property and sufficient transparency for the release film to have a total light transmittance of 80% or more. In addition, "there is release property" means that the layer which consists only of the said resin can function as a release layer.

Although the antistatic layer may be comprised only of the conductive polymer which is an antistatic agent, it is preferable to consist of a layer containing an antistatic agent and a resin binder. The antistatic layer containing an antistatic agent and a resin binder is preferably formed by applying a coating solution containing an antistatic agent, a resin binder, and a liquid medium such as a solvent to one side of a releasable substrate and removing the liquid medium. Alternatively, it may be formed by laminating a film containing an antistatic agent and a resin binder on one side of a releasable substrate.

[Release film of the first embodiment]

1 is a schematic sectional view showing a first embodiment of a release film of the present invention.

The release film 1 of the first embodiment includes a release base material 2 in contact with the curable resin when forming the resin encapsulation portion, and an antistatic layer 3 in contact with the mold when forming the resin encapsulation portion. The releasable substrate 2 has a single-layer structure.

The release film 1 is disposed so that the surface 2a on the side of the release property substrate 2 faces the cavity of the mold during manufacture of the semiconductor package, and contacts the curable resin during formation of the resin encapsulation portion. In addition, at this time, the surface 3a on the side of the antistatic layer 3 adheres to the cavity surface of the mold. By curing the curable resin in this state, a resin sealing portion having a shape corresponding to the shape of the cavity of the mold is formed.

(total light transmittance)

The total light transmittance of the release film 1 is 80% or more, preferably 85% or more. If the total light transmittance is 80% or more, when the release film 1 is actually set in the semiconductor sealing device, the position of the mold is easy to be recognized over the release film 1. Therefore, positioning of the release film 1 and the mold is easy, and a suction error in which the position of the release film is displaced from the vacuum adsorption hole for fixing the release film is less likely to occur. In addition, since it can be confirmed with the naked eye when a foreign matter is engaged between the mold and the release film 1, the probability of a defective product in which the shape of the foreign matter is transferred to the resin encapsulation portion through the release film 1 is lowered.

The upper limit of the total light transmittance is not particularly set, but it may be 99% or less.

(releasability description)

As the releasable base material 2, one containing a releasable transparent resin (however, an antistatic agent is not included) is exemplified.

Examples of the releasable transparent resin include fluororesins, polymethylpentene, syndiotactic polystyrene, and releasable silicone resins from the standpoint of being excellent in releasability, heat resistance at a semiconductor package sealing temperature (eg 180°C), and mold followability. desirable. Among them, fluororesins, polymethylpentene, and syndiotactic polystyrene are preferred, and fluororesins are particularly preferred, from the viewpoint of excellent releasability. These resins may be used individually by 1 type, and may use 2 or more types together.

As the fluororesin, a fluoroolefin-based polymer is preferable in view of excellent release properties and heat resistance. A fluoroolefin-based polymer is a polymer having units based on fluoroolefins. The fluoroolefin-based polymer may further have units other than units based on fluoroolefin.

Examples of the fluoroolefin include tetrafluoroethylene (hereinafter, also referred to as "TFE"), vinyl fluoride, vinylidene fluoride, trifluoroethylene, hexafluoropropylene, and chlorotrifluoroethylene. A fluoroolefin may be used individually by 1 type, and may use 2 or more types together.

As the fluoroolefin polymer, ethylene-tetrafluoroethylene copolymer (ETFE), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), tetrafluoroethylene-perfluoro (alkyl vinyl ether) copolymer (PFA), tetrafluoroethylene-hexafluoropropylene-vinylidene fluoride copolymer (THV), and the like. A fluoroolefin type polymer may be used individually by 1 type, and may use 2 or more types together.

As the fluoroolefin-based polymer, ETFE is particularly preferred because of its high elongation at high temperatures. ETFE is a copolymer having units based on TFE (hereinafter also referred to as "TFE units") and units based on ethylene (hereinafter also referred to as "E units").

As ETFE, a polymer having TFE units, E units, and units based on a third monomer other than TFE and ethylene is preferable. Depending on the type and content of the unit based on the third monomer, the degree of crystallization of ETFE and, consequently, the tensile properties of the releasable base material 2 can be easily adjusted. For example, by having a unit based on a third monomer (particularly a monomer having a fluorine atom), the tensile strength at high temperature (particularly around 180°C) is improved.

As a 3rd monomer, the monomer which has a fluorine atom and the monomer which does not have a fluorine atom are mentioned.

As a monomer which has a fluorine atom, the following monomers (a1) - (a5) are mentioned.

Monomer (a1): C2 or C3 fluoroolefins.

Monomer (a2): A fluorine-containing monomer represented by X(CF ₂ ) _n CY=CH ₂ (provided that X and Y are each independently a hydrogen atom or a fluorine atom, and n is an integer of 2 to 8).

Monomer (a3): Fluorovinyl ether.

Monomer (a4): Fluorovinyl ether containing a functional group.

Monomer (a5): A fluorine-containing monomer having an aliphatic ring structure.

As the monomer (a1), fluoroethylenes (trifluoroethylene, vinylidene fluoride, vinyl fluoride, chlorotrifluoroethylene, etc.), fluoropropylenes (hexafluoropropylene (hereinafter also referred to as "HFP") , 2-hydropentafluoropropylene, etc.), etc. are mentioned.

As a monomer (a2), the monomer whose n is 2-6 is preferable, and the monomer whose n is 2-4 is especially preferable. Moreover, a monomer in which X is a fluorine atom and Y is a hydrogen atom, that is, (perfluoroalkyl)ethylene is particularly preferred.

Specific examples of the monomer (a2) include the following compounds.

CF ₃ CF ₂ CH=CH ₂ ,

CF ₃ CF ₂ CF ₂ CF ₂ CH=CH ₂ ((perfluorobutyl)ethylene. Hereinafter also referred to as “PFBE”),

CF ₃ CF ₂ CF ₂ CF ₂ CF=CH ₂ ,

CF ₂ HCF ₂ CF ₂ CF=CH ₂ ,

CF ₂ HCF ₂ CF ₂ CF ₂ CF=CH ₂ and so on.

Specific examples of the monomer (a3) include the following compounds. In addition, among the following, monomers which are dienes are monomers capable of cyclization polymerization.

CF ₂ =CFOCF ₃ ,

CF ₂ =CFOCF ₂ CF ₃ ,

CF ₂ =CF(CF ₂ ) ₂ CF ₃ (perfluoro(propyl vinyl ether). Hereinafter also referred to as “PPVE”),

CF ₂ =CFOCF ₂ CF(CF ₃ )O(CF ₂ ) ₂ CF ₃ ,

CF ₂ =CFO(CF ₂ ) ₃ O(CF ₂ ) ₂ CF ₃ ,

CF ₂ =CFO(CF ₂ CF(CF ₃ )O) ₂ (CF ₂ ) ₂ CF ₃ ,

CF ₂ =CFOCF ₂ CF(CF ₃ )O(CF ₂ ) ₂ CF ₃ ,

CF ₂ =CFOCF ₂ CF=CF ₂ ,

CF ₂ =CFO(CF ₂ ) ₂ CF=CF ₂ and so on.

Specific examples of the monomer (a4) include the following compounds.

CF ₂ =CFO(CF ₂ ) ₃ CO ₂ CH ₃ ,

CF ₂ =CFOCF ₂ CF(CF ₃ )O(CF ₂ ) ₃ CO ₂ CH ₃ ,

CF ₂ =CFOCF ₂ CF(CF ₃ )O(CF ₂ ) ₂ SO ₂ F and so on.

Specific examples of the monomer (a5) include perfluoro(2,2-dimethyl-1,3-dioxole), 2,2,4-trifluoro-5-trifluoromethoxy-1,3-di Oxol, perfluoro (2-methylene-4-methyl-1,3-dioxolane), etc. are mentioned.

As a monomer which does not have a fluorine atom, the following monomers (b1) - (b4) are mentioned.

Monomer (b1): olefins.

Monomer (b2): Vinyl esters.

Monomer (b3): Vinyl ethers.

Monomer (b4): An unsaturated acid anhydride.

Specific examples of the monomer (b1) include propylene and isobutene.

Vinyl acetate etc. are mentioned as a specific example of a monomer (b2).

Ethyl vinyl ether, butyl vinyl ether, cyclohexyl vinyl ether, hydroxybutyl vinyl ether etc. are mentioned as a specific example of a monomer (b3).

Specific examples of the monomer (b4) include maleic anhydride, itaconic anhydride, citraconic anhydride, and hymic acid anhydride (5-norbornene-2,3-dicarboxylic acid anhydride).

A 3rd monomer may be used individually by 1 type, and may use 2 or more types together.

As the third monomer, it is easy to adjust the crystallinity and has a unit based on the third monomer (particularly a monomer having a fluorine atom), and thus has excellent tensile strength at a high temperature (particularly around 180 ° C.), a monomer ( a2), HFP, PPVE, and vinyl acetate are preferable, HFP, PPVE, CF ₃ CF ₂ CH=CH ₂ , and PFBE are more preferable, and PFBE is particularly preferable. That is, as ETFE, a copolymer having a TFE unit, an E unit, and a unit based on PFBE is particularly preferred.

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

The proportion of units based on the third monomer in ETFE is preferably from 0.01 to 20 mol%, more preferably from 0.10 to 15 mol%, more preferably from 0.20 to 10 mol% with respect to the total (100 mol%) of all units constituting ETFE. Mole% is particularly preferred. When the ratio of units based on the third monomer is within the above range, the heat resistance and mechanical strength of ETFE are excellent.

When the units based on the third monomer include units based on PFBE, the ratio of units based on PFBE is preferably 0.5 to 4.0 mol% with respect to the total of all units constituting ETFE (100 mol%). , 0.7 to 3.6 mol% is more preferable, and 1.0 to 3.6 mol% is particularly preferable. If the ratio of units based on PFBE is within the above range, the tensile modulus of elasticity at 180°C of the release film can be adjusted within the above range. In addition, the tensile strength at high temperatures (particularly around 180°C) is improved.

The melt flow rate (MFR) of ETFE is preferably 2 to 40 g/10 min, more preferably 5 to 30 g/10 min, and particularly preferably 10 to 20 g/10 min. MFR is a standard for molecular weight, and the larger the MFR, the smaller the molecular weight tends to be. When the MFR of ETFE is within the above range, the moldability of ETFE is improved and the release film has excellent mechanical strength.

The MFR of ETFE is a value measured under a load of 49 N and 297°C in accordance with ASTM D3159.

The releasable base material 2 may consist of only the releasable transparent resin, or may further contain components other than the releasable transparent resin in addition to the releasable transparent resin.

For example, you may contain a release component other than the release property transparent resin in the range which does not impair transparency and the adhesiveness of the release property base material 2 and the antistatic layer 3. Examples of the release component include silicone oil and fluorine-based surfactants.

From the point of usefulness of this invention, it is preferable that the releasable base material 2 does not contain an antistatic agent.

As the releasable substrate 2, a layer containing a fluororesin is preferable, and a layer composed only of a fluororesin is particularly preferable. In this case, the release film 1 has excellent release properties, heat resistance that can withstand the temperature of the mold during molding (typically 150 to 180 ° C.), and strength that can withstand the flow of the curable resin and pressure. It has enough, and the elongation in high temperature is also excellent.

The surface 2a of the releasable base material 2 in contact with the curable resin during formation of the resin sealing portion, that is, the surface 2a on the side of the releasable base material 2 of the release film 1, may be smooth or uneven. In terms of excellent releasability, it is preferable that irregularities are formed.

The surface shape in the case where unevenness is formed may be a shape in which a plurality of convex portions and/or concave portions are randomly distributed, or a shape in which a plurality of convex portions and/or concave portions are regularly arranged. The shapes and sizes of the plurality of convex portions and/or concave portions may be the same or different.

Examples of the convex portion include long iron bars extending on the surface of the release film, dotted projections, and the like, and examples of the concave portion include long grooves extending on the surface of the release film, dotted holes, and the like. can be heard

Examples of the shape of the barbed wire or groove include a straight line, a curved shape, and a curved shape. On the surface of the release film, a plurality of iron lines or grooves may exist in parallel to form a stripe shape. Examples of the cross-sectional shape of the barbed wire or groove in the direction orthogonal to the longitudinal direction include a polygonal shape such as a triangle (V shape), a semicircular shape, and the like.

Examples of the shape of the protrusion or hole include polygonal pyramidal shapes such as triangular pyramidal shape, quadrangular pyramidal shape and hexagonal pyramidal shape, conical shape, hemispherical shape, polyhedral shape, and various other irregular shapes.

The arithmetic average roughness Ra of the surface 2a is preferably from 0.1 to 2.5 μm, particularly preferably from 0.2 to 2.0 μm. When the arithmetic mean roughness Ra of the surface 2a is equal to or greater than the lower limit of the above range, traces of resin flow (flow marks) in the formed resin sealing portion are not conspicuous. When the arithmetic mean roughness Ra of the surface 2a is equal to or less than the upper limit of the above range, the visibility of the marking applied to the resin sealing portion after formation of the resin sealing portion is more excellent.

The arithmetic average roughness Ra of the surface of the releasable substrate 2 on the side of the antistatic layer 3 is preferably from 0.2 to 2.5 µm, particularly preferably from 0.2 to 2.0 µm. If the arithmetic average roughness Ra of the surface on the antistatic layer 3 side is within the above range, when the antistatic layer 3 is formed on the releasable substrate 2, the releasable substrate 2 side of the antistatic layer 3 arithmetic mean roughness Ra of the surface on the opposite side, that is, the surface 3a on the side of the antistatic layer 3 of the release film 1, tends to fall within the range described later.

Arithmetic average roughness Ra is a value measured based on JIS B0601:2013 (ISO 4287:1997, Amd.1:2009). The standard length lr (cutoff value λc) for the roughness curve is 0.8 mm.

It is preferable that it is 12-100 micrometers, and, as for the thickness of the releasable base material 2, 25-75 micrometers are especially preferable. If the thickness of the releasable substrate 2 is at least the lower limit of the above range, "cracks" of the antistatic layer 3 due to "folding" of the releasable substrate 2 are less likely to occur, and antistatic properties are less likely to be impaired. In addition, handling of the release film 1 is easy (for example, handling by roll-to-roll), and wrinkles are less likely to occur when disposing the release film 1 so as to cover the cavity of the mold while pulling it. When the thickness of the releasable substrate 2 is equal to or less than the upper limit of the above range, the antistatic effect of the antistatic layer 3 sufficiently extends to the surface (sealing surface) of the releasable substrate 2 side. In addition, the release film 1 can be easily deformed and has excellent mold followability.

(antistatic layer)

The antistatic layer 3 contains at least one antistatic agent (hereinafter also referred to as "antistatic agent (I)") selected from the group consisting of conductive polymers and conductive metal oxides.

A conductive polymer is a polymer in which electrons move and diffuse along the backbone of the polymer. Examples of the conductive polymer include polyaniline-based polymers, polyacetylene-based polymers, polyparaphenylene-based polymers, polypyrrole-based polymers, polythiophene-based polymers, and polyvinylcarbazole-based polymers.

20,000-500,000 are preferable, and, as for the mass average molecular weight of a conductive polymer, 40,000-200,000 are especially preferable. When the mass average molecular weight of the conductive polymer is outside the above range (ie, less than 20,000 or greater than 500,000), the dispersion stability of the conductive polymer in water may decrease. The mass average molecular weight is measured by, for example, gel permeation chromatography (GPC) using an ultrahydrogel500 column manufactured by Waters, etc.

Examples of the conductive metal oxide include tin-doped indium oxide, antimony-doped tin oxide, phosphorus-doped tin oxide, zinc antimonate, and antimony oxide.

Antistatic agent (I) may be used individually by 1 type, and may use 2 or more types together.

As the antistatic agent (I), a polyaniline-based polymer, a polypyrrole-based polymer, and a polythiophene-based polymer are preferable from the viewpoint of excellent heat resistance and conductivity.

In the antistatic layer 3, the antistatic agent (I) is preferably dispersed in a resin binder. That is, the antistatic layer 3 is preferably a layer in which the antistatic agent (I) is dispersed in a resin binder.

The resin binder is not particularly limited as long as it has heat resistance capable of withstanding heat (for example, 180°C) in the sealing step. In terms of excellent heat resistance, the resin binder is an acrylic resin, a silicone resin, a urethane resin, a polyester resin, a polyamide resin, a vinyl acetate resin, an ethylene-vinyl acetate copolymer, an ethylene-vinyl alcohol copolymer, chlorotrifluoroethylene - It is preferable to contain at least 1 sort(s) selected from the group which consists of a vinyl alcohol copolymer and a tetrafluoroethylene-vinyl alcohol copolymer. Among them, from the viewpoint of excellent mechanical strength, acrylic resins, silicone resins, urethane resins, polyester resins, polyamide resins, vinyl acetate resins, ethylene-vinyl acetate copolymers, ethylene-vinyl alcohol copolymers, chlorotrifluoroethylene - It is preferable to consist of any one type (for example, only an acrylic resin) of a vinyl alcohol copolymer and a tetrafluoroethylene-vinyl alcohol copolymer.

As the resin binder, a polyester resin and an acrylic resin are particularly preferable in terms of heat resistance and excellent dispersibility of the antistatic agent (I).

In the antistatic layer 3, the resin binder may be crosslinked. When the resin binder is crosslinked, heat resistance is excellent compared to the case where it is not crosslinked.

The antistatic layer 3 may further contain an antistatic agent other than the antistatic agent (I) within a range that does not impair the effects of the present invention.

As another antistatic agent, a humidity dependent antistatic agent is mentioned, for example. Humidity-dependent antistatic agents are antistatic agents that do not themselves have conductivity, and examples thereof include cationic copolymers having quaternary ammonium base groups on side groups, anionic polymers containing polystyrene sulfonic acid, polyether ester amides, and ethylene oxide- Epichlorohydrin oligomers, nonionic polymers including polyether esters, silicate oligomers, and the like are exemplified. These prevent electrification by adsorbing moisture in the air and releasing charge through the moisture. However, at a high temperature of 100 deg.

On the other hand, since the antistatic agent (I) itself has conductivity, the antistatic action obtained by the antistatic agent (I) does not depend on humidity (specific humidity dependence), and is exhibited even at high temperatures of 100 ° C. or higher.

The antistatic layer 3 may contain additives other than the antistatic agent within a range that does not impair antistatic properties and transparency. Examples of the additives include lubricants, colorants, and coupling agents that improve releasability with the mold. Examples of the lubricant include microbeads made of a thermoplastic resin, fumed silica, and polytetrafluoroethylene (PTFE) fine particles. As the coloring agent, various organic and inorganic coloring agents can be used, and examples thereof include cobalt blue, bengala, and cyanine blue. A silane coupling agent, a titanate coupling agent, etc. are mentioned as a coupling agent.

The content of the antistatic agent (I) in the antistatic layer 3 is preferably such that the surface resistance of the antistatic layer 3 is 10 ¹⁰ Ω/□ or less. The surface resistance value of the antistatic layer 3 is particularly preferably 10 ⁹ Ω/□ or less. If the surface resistance value is equal to or less than the above upper limit, the charge of the releasable substrate 2 at the time of peeling the semiconductor package and the release film 1 can be sufficiently neutralized, and the apparent charge can be made zero. The lower limit of the antistatic layer 3 is not particularly limited, but is preferably 10 ⁴ Ω/□ or more.

When the antistatic layer 3 is a layer in which the antistatic agent (I) is dispersed in a resin binder, the content of the antistatic agent (I) is preferably 3 to 50% by mass, and 5 to 50% by mass relative to the resin binder (100% by mass). 20 mass % is especially preferable. When the content of the antistatic agent (I) is equal to or more than the lower limit of the range, the surface resistance of the antistatic layer 3 tends to be equal to or less than the upper limit, depending on the type of the antistatic agent (I). When the content of the antistatic agent (I) is equal to or less than the upper limit of the above range, the adhesion between the antistatic layer 3 and the releasable substrate is excellent.

The content of the humidity-dependent antistatic agent in the antistatic layer 3 is not particularly limited, but considering cost, dispersibility, etc., it is preferably 10% by mass or less relative to the antistatic agent (I) (100% by mass), and 0 Mass % is particularly preferred. That is, it is particularly preferable that the antistatic layer 3 does not contain a humidity-dependent antistatic agent.

The thickness of the antistatic layer 3 is preferably 100 to 1,000 nm, particularly preferably 200 to 800 nm. When the thickness of the antistatic layer 3 is equal to or greater than the lower limit of the above range, the antistatic layer 3 tends to form a continuous coating film, and excellent antistatic properties are easily obtained. When the thickness is equal to or less than the upper limit of the above range, peeling of the antistatic layer 3 is less likely to occur.

The arithmetic mean roughness Ra of the surface of the antistatic layer 3 on the opposite side to the release base material 2 side, that is, the surface 3a of the release film 1 on the antistatic layer 3 side, is preferably 0.2 to 2.5 μm. and is particularly preferably 0.2 to 2.0 μm. When the arithmetic mean roughness Ra of the surface 3a is equal to or greater than the lower limit of the above range, blocking between the surface 3a and the mold is less likely to occur, and wrinkles due to blocking are less likely to occur. When the arithmetic mean roughness Ra of the surface 3a is equal to or less than the upper limit of the above range, when forming the antistatic layer 3, a film of a resin binder (not containing the antistatic agent (I)) is formed near the surface of the antistatic layer 3. film) is difficult to form, and antistatic properties are easily exhibited sufficiently.

(Film charging voltage after encapsulation)

The release film 1 preferably has a film charging voltage of 200 V or less after sealing as measured by the following measurement method, and particularly preferably 100 V or less.

The post-sealing film electrification voltage is an index indicating the difficulty of charging the release film when the resin encapsulation portion and the release film are separated after forming the resin encapsulation portion. The smaller the film charging voltage after encapsulation, the less likely it is to be charged when the resin encapsulation and the release film are separated.

<Method for measuring film electrification voltage after sealing>

On a 13 cm × 13 cm first stainless steel (hereinafter also referred to as “SUS”) plate, a 13 cm × 13 cm, 100 μm thick aluminum foil (JIS H4000: 2006 AlN30P) was placed, and on it as a spacer A polyimide film having a size of 10 cm × 12 cm and a thickness of 125 μm was cut out in the center to a size of 8 cm × 10 cm, and further, on the cut-out portion of the polyimide film, an epoxy resin for semiconductor encapsulation as a curable resin Sumikon 2.7 g of EME G770H typeF ver.GR (manufactured by Sumitomo Bakelite Co., Ltd.) was sprinkled. On top of that, the release film of 13 cm x 13 cm was removed in advance, and then the antistatic layer side and the opposite surface were placed in contact with the curable resin, and a second SUS of 13 cm x 13 cm was further placed thereon A plate is placed and it is set as a sample.

The sample produced in the above procedure was pressed with a press machine at a temperature of 180 ° C., a pressure of 1 MPa, and a time of 3 minutes, and after taking it out of the press machine, the whole was placed on a hot plate at 180 ° C., and after removing the second SUS plate, mold release The film is peeled off over 5 seconds. Within 5 seconds after that, the electrostatic voltage on the side of the peeled release film that was in contact with the curable resin is measured using a surface electrometer while fixing the distance between the release film and the measurement terminal to 3 cm.

(Method of manufacturing release film)

The release film 1 can be manufactured, for example, by a manufacturing method comprising the following step (i).

(i) On one side of the releasable substrate 2, a coating solution containing an antistatic agent (I), a resin binder, and a liquid medium (hereinafter also referred to as "antistatic solution") is coated and dried, A step of forming the antistatic layer 3 by crosslinking the resin binder as necessary.

After drying, you may crosslink the said resin binder as needed.

On the surface of the releasable base material 2 coated with the antistatic liquid, surface treatment may be performed in order to improve adhesion to the antistatic layer 3. As surface treatment, corona treatment, plasma treatment, silane coupling agent coating, application of an adhesive agent, etc. are mentioned.

<Antistatic liquid>

The antistatic agent (I) and the resin binder are each the same as above.

As a liquid medium, water, an organic solvent, etc. are mentioned. Alcohol compounds, ester compounds, etc. are mentioned as an organic solvent.

When crosslinking the resin binder, the antistatic solution may further contain a crosslinking agent. A known crosslinking agent can be used, and examples thereof include isocyanate compounds, epoxy resins, melamine resins, and aziridine compounds.

1-10 mass % is preferable, and, as for the solid content concentration of antistatic liquid, 2-8 mass % is especially preferable. When the solid content concentration is equal to or greater than the lower limit of the above range, coatability is excellent, and when the solid content concentration is equal to or less than the upper limit, the dispersibility of the antistatic agent (I) or the like is excellent.

<Process (i)>

As the coating method of the antistatic liquid, various well-known wet coating methods can be used, and examples thereof include a gravure coating method and a die coating method. As for drying temperature, 50-100 degreeC is preferable.

Examples of the crosslinking method of the resin binder include ultraviolet (UV) crosslinking and thermal crosslinking. The drying process may also serve as a thermal crosslinking process.

(action effect)

In the release film 1, since the antistatic layer in contact with the mold during formation of the resin sealing portion contains the antistatic agent (I), it exhibits excellent antistatic action even under a high temperature environment (eg 180 ° C.). Specifically, according to the release film 1, when forming a resin encapsulation portion for sealing a semiconductor element by a manufacturing method of a semiconductor package, when the release film and the semiconductor element come into contact, the release film becomes difficult to be charged. Moreover, when the resin sealing part and the release film are separated after forming the resin encapsulation part for sealing the semiconductor element in the manufacturing method of the semiconductor package, the release film becomes difficult to be charged. As a result, charge-discharge at the time of peeling can be sufficiently suppressed, making it difficult for the semiconductor element to be destroyed.

Moreover, in the release film 1, the total light transmittance is 80% or more, and transparency is high. Therefore, in the case of manufacturing a semiconductor package, adsorption errors at the time of adsorbing the release film to the mold are less likely to occur.

In order to obtain an excellent antistatic action even under a high temperature environment (for example, 180 ° C.), the position of the antistatic layer in the release film and the type of antistatic agent contained in the antistatic layer are important.

Since the antistatic layer 3 is the layer in contact with the mold during formation of the resin sealing portion, the antistatic layer 3 contacts the metal portion of the mold. Therefore, it becomes possible to quickly diffuse the electric charge remaining in the releasable base material 2 by peeling, and to make the electrical charge voltage zero. In the case where the release film has a structure in which the antistatic layer 3 does not come into direct contact with the mold, the slight electric charge generated continues to remain without being charged for a long time. In particular, in the production of a semiconductor package with a structure in which a semiconductor element sensitive to static electricity is exposed, if the release film is charged with static electricity even for a moment at the moment the semiconductor element and the release film come into contact, an electric charge is generated from the static electricity to the semiconductor element, easily destroyed Therefore, it is preferable that the charging voltage when the release film adsorbs and contacts the mold is zero.

In addition, as described above, the antistatic agent (I) is a non-humidity dependent antistatic agent, and exerts an antistatic action even under a high temperature (eg 180°C) sealing temperature of the semiconductor package. When the antistatic agent is a humidity-dependent one (for example, a cationic antistatic agent having a quaternary ammonium salt), the antistatic action is based on the principle of adsorbing moisture in the air and releasing electric charge, so that the semiconductor package At the sealing temperature, the adsorbed moisture is desorbed and the antistatic action is lost.

[Release film of the second embodiment]

Fig. 2 is a schematic cross-sectional view showing a second embodiment of the release film of the present invention. In addition, in the following, the same reference numerals are given to components corresponding to the first embodiment, and detailed descriptions thereof are omitted.

The release film 4 of the second embodiment includes a release base material 5 in contact with the curable resin when forming the resin encapsulation portion, and an antistatic layer 3 in contact with the mold when forming the resin encapsulation portion. The releasable substrate 5 is provided with a release layer 5B formed by coating a release layer forming agent on one side (surface on the opposite side to the antistatic layer 3 side) of the base body 5A.

The release film 4 is disposed with the surface 5a on the side of the releasable base material 5 facing the cavity of the mold during manufacture of the semiconductor package, and contacts the curable resin during formation of the resin encapsulation portion. In addition, at this time, the surface 3a on the side of the antistatic layer 3 adheres to the cavity surface of the mold. By curing the curable resin in this state, a resin sealing portion having a shape corresponding to the cavity shape of the mold is formed.

(releasability description)

As the substrate body 5A, it is transparent and can be selected from any material that can be used at the sealing temperature of the semiconductor package (for example, 180°C). As a material of 5 A of base body main bodies, polyester resin, polyamide resin, polycarbonate resin, polyurethane elastomer, polyester elastomer etc. are mentioned, for example.

As a release layer forming agent which forms release layer 5B, the liquid curable silicone resin used as the said release property transparent resin solution, release property silicone resin, etc. are mentioned, for example.

The surface 5a of the releasable base material 5 in contact with the curable resin during formation of the resin sealing portion, that is, the surface 5a on the side of the releasable base material 5 of the release film 4, may be smooth or uneven. In terms of releasability, it is preferable that irregularities are formed. The preferred aspect for the unevenness is the same as that of the releasable substrate 2 described above, and the preferred aspect for the surface 5a is the same as that of the surface 2a described above.

The preferred range of the thickness of the releasable substrate 5 is the same as that of the releasable substrate 2.

The thickness of the release layer 5B is preferably from 0.2 to 5 μm, particularly preferably from 0.5 to 2 μm. When the thickness of the release layer 5B is equal to or greater than the lower limit of the range, the release property is more excellent, and when the thickness is equal to or less than the upper limit, antistatic properties are excellent.

(Method of manufacturing release film)

The release film 4 can be manufactured in the same manner as the release film 1 of the first embodiment, except that the release substrate 5 is used instead of the release substrate 2.

As the releasable substrate 5, a commercially available substrate may be used, or a substrate manufactured by a known method may be used.

(Film charging voltage after encapsulation)

The film charging voltage after sealing of the release film 4 measured by the above measurement method is preferably 200 V or less, and particularly preferably 100 V or less, similarly to the release film 1.

(action effect)

In the release film 4, as in the release film 1 of the first embodiment, an excellent antistatic action is exhibited even under a high temperature environment (for example, 180°C). Moreover, it is excellent in transparency.

As mentioned above, although the 1st - 2nd embodiment was shown and demonstrated about the release film of this invention, this invention is not limited to the said embodiment. Each configuration and combination thereof in the above embodiment is an example, and addition, omission, substitution, and other changes to the configuration are possible within a range not departing from the spirit of the present invention.

The releasable substrate 2 in the first embodiment may be a multilayer structure obtained by laminating a plurality of transparent resin films. In this case, at least the layer constituting the surface in contact with the curable resin is made of a releasable transparent resin. The transparent resin constituting each of the plurality of layers may be the same or different, and all of the plurality of layers may consist of a releasable transparent resin. Examples of transparent resins other than releasable transparent resins include acrylic resins, polyester resins, polyamide resins, polycarbonate resins, polyurethane elastomers, and polyester elastomers.

In terms of mold followability, tensile elongation, manufacturing cost and the like, the releasable substrate 2 is preferably a single-layer structure of the releasable transparent resin.

In 1st and 2nd Embodiment, although the thing which laminated|stacked directly the releasable base material and the antistatic layer was shown, the release film of this invention may provide another layer between the releasable base material and the antistatic layer.

As another layer, a gas barrier layer, a coloring layer, a rigid layer (PET film etc.) etc. are mentioned, for example. These layers may be used individually by any 1 type, and may use 2 or more types together.

As the release film of the present invention, from the side in contact with the curable resin at the time of forming the resin sealing portion, any layer configuration of a release substrate / antistatic layer, a release substrate / gas barrier layer / antistatic layer, a release substrate / coloring layer / antistatic layer it is desirable to have Among them, from the viewpoint of excellent antistatic properties, it is preferable to have a layer configuration of a releasable substrate/antistatic layer in which the antistatic layer and the releasable substrate are in direct contact. is particularly preferred.

[Semiconductor Package]

As a semiconductor package manufactured by the manufacturing method of the semiconductor package of this invention mentioned later using the release film of this invention, Integrated circuit which integrated semiconductor elements, such as a transistor and a diode; and a light emitting diode having a light emitting element.

The package shape of the integrated circuit may cover the entire integrated circuit or may cover a part of the integrated circuit (exposing a part of the integrated circuit). As a specific example, BGA (Ball Grid Array), QFN (Quad Flat Non-leaded package), SON (Small Outline Non-leaded package), etc. are mentioned.

As a semiconductor package, from the viewpoint of productivity, it is preferable to manufacture through batch encapsulation and singulation. can be heard

3 is a schematic cross-sectional view showing an example of a semiconductor package.

The semiconductor package 110 of this example includes a substrate 10, a semiconductor chip 12 mounted on the substrate 10, a resin sealing portion 14 for sealing the semiconductor chip 12, and a resin sealing portion. It has an ink layer (16) formed on the upper surface (14a) of (14).

The semiconductor chip 12 has a surface electrode (not shown), the substrate 10 has a substrate electrode (not shown) corresponding to the surface electrode of the semiconductor chip 12, and the surface electrode and the substrate electrode are bonding wires. They are electrically connected by (18).

The thickness of the resin encapsulation portion 14 (the shortest distance from the mounting surface of the semiconductor chip 12 of the substrate 10 to the upper surface 14a of the resin encapsulation portion 14) is not particularly limited, but "semiconductor chip 12 )” or more and “thickness of semiconductor chip 12 + 1 mm” or less is preferable, and “thickness of semiconductor chip 12” or more and “thickness of semiconductor chip 12 + 0.5 mm” or less is particularly preferable.

4 is a schematic cross-sectional view showing another example of a semiconductor package.

The semiconductor package 120 of this example includes a substrate 70, a semiconductor chip 72 mounted on the substrate 70, and an underfill (resin sealing portion) 74.

The underfill 74 fills a gap between the substrate 70 and the main surface of the semiconductor chip 72 (surface on the side of the substrate 70), and fills the gap between the back surface of the semiconductor chip 72 (from the side of the substrate 70) surface on the opposite side) is exposed.

[Method of manufacturing semiconductor package]

For the manufacturing method of the semiconductor package of the present invention, a known manufacturing method can be employed except for using the release film of the present invention. For example, a compression molding method or a transfer molding method can be used as a method for forming the resin encapsulation portion, and a known compression molding device or transfer molding device can be used as an apparatus used at this time. The manufacturing conditions may also be set to the same conditions as the conditions in a known semiconductor package manufacturing method.

(1st Embodiment)

5-7, the 1st Embodiment of the manufacturing method of the semiconductor package of this invention is described. This embodiment is an example in which the semiconductor package 110 shown in FIG. 3 is manufactured by a compression molding method using the release film 1 described above as a release film.

The manufacturing method of the semiconductor package of this embodiment includes the following steps (?1) to (?7).

(α1) In a mold having a fixed upper mold 20, a cavity bottom member 22, and a frame-shaped movable lower mold 24 disposed on the circumferential edge of the cavity bottom member 22, the release film 1 is Cover the cavity 26 of the mold and the surface 2a of the release film 1 on the side of the releasable substrate 2 faces the space in the cavity 26 (the surface 3a on the side of the antistatic layer 3 is the mold step of arranging the release film 1 so as to be in contact with the cavity surface of (FIG. 5).

(α2) A step of vacuuming the release film 1 toward the cavity surface of the mold (FIG. 5).

((alpha)3) The process of filling curable resin 40 in the cavity 26 whose cavity surface was covered with the release film 1 (FIG. 5).

(α4) A substrate 10 on which a plurality of semiconductor elements including semiconductor chips 12 and the like are mounted is placed at a predetermined position in the cavity 26, and a mold is clamped (FIG. 6), and cured resin 40 The substrate 10, the plurality of semiconductor elements mounted on the substrate 10, and the plurality of semiconductor elements are collectively sealed by encapsulating the semiconductor elements and forming the resin encapsulation portion 14 (FIG. 7). A step of obtaining a collectively encapsulated body having the resin encapsulation portion 14.

((alpha)5) The process of taking out the said collectively encapsulated body from inside a metal mold|die.

(α6) the substrate 10 and at least one semiconductor element mounted on the substrate 10 by cutting the substrate 10 and the resin encapsulation portion 14 of the collectively encapsulated body so that the plurality of semiconductor elements are separated; and a step of obtaining a singulated encapsulated body having a resin encapsulation portion 14 for encapsulating the semiconductor element.

(?7) A step of forming an ink layer 16 on the upper surface 14a of the resin encapsulation portion 14 of the singulated encapsulation body using ink to obtain the semiconductor package 110.

(Second Embodiment)

8-11, the 2nd Embodiment of the manufacturing method of the semiconductor package of this invention is described. This embodiment is an example in which the semiconductor package 120 shown in FIG. 4 is manufactured by a transfer method using the release film 1 described above as a release film.

The manufacturing method of the semiconductor package of this embodiment includes the following steps (β1) to (β5).

(β1) The release film 1 covers the cavity 54 of the upper mold 50 of the mold having the upper mold 50 and the lower mold 52, and the surface of the release film 1 on the side of the release-resistant base material 2 ( 2a) a step of disposing the release film 1 so that the surface 3a on the side of the antistatic layer 3 is in contact with the cavity face 56 of the upper mold 50 so that it faces the space in the cavity 54 (Fig. 8).

((beta)2) The process of vacuum-sucking the release film 1 to the side of the cavity surface 56 of the upper mold|type 50 (FIG. 9).

(β3) A substrate 70 on which semiconductor elements including semiconductor chips 72 and the like are mounted is placed on the substrate mounting portion 58 of the lower mold 52, and the upper mold 50 and the lower mold 52 are mold-clamped, , a step of adhering the release film 1 to the back surface of the semiconductor chip 72 (surface on the opposite side to the substrate 70 side) (FIG. 9).

(β4) The plunger 64 of the resin placement part 62 of the lower mold 52 is pushed up, and the curable resin 40 previously placed in the resin placement part 62 is removed from the resin introduction part 60 of the upper mold 50. A step of obtaining a semiconductor package 120 (encapsulated body) having a substrate 70, a semiconductor element, and an underfill 74 by filling the cavity 54 through and curing to form an underfill 74 (FIG. 10) .

(β5) A step of taking out the semiconductor package 120 from inside the mold (FIG. 11). A cured product 76 in which the curable resin 40 is cured in the resin introduction portion 60 is attached to the underfill 74 of the semiconductor package 120 taken out at this time. The cured product 76 is excised to obtain the semiconductor package 120 .

As mentioned above, although the 1st and 2nd embodiment were shown and demonstrated about the manufacturing method of the semiconductor package of this invention, this invention is not limited to the said embodiment. Each configuration and combination thereof in the above embodiment is an example, and addition, omission, substitution, and other changes to the configuration are possible within a range not departing from the spirit of the present invention.

In the first embodiment, the example in which the step (α6) and the step (α7) are performed in this order after the step (α5) is shown, but the step (α6) and the step (α7) may be performed in the reverse order. do. That is, an ink layer may be formed using ink on the surface of the resin encapsulation portion of the encapsulation body taken out of the mold, and then the substrate and the resin encapsulation portion of the encapsulation body may be cut.

The timing of peeling the resin encapsulation from the release film is not limited to when the resin encapsulation is taken out of the mold, and the resin encapsulation may be taken out from the mold together with the release film, and then the release film may be peeled from the resin encapsulation.

The distance between each of the plurality of semiconductor elements encapsulated collectively may be uniform or non-uniform. Since the sealing can be made homogeneous and the load applied to each of the plurality of semiconductor elements becomes uniform (the load becomes the smallest), it is preferable to make the distance between each of the plurality of semiconductor elements uniform.

The semiconductor package 110 may be manufactured by a transfer molding method as in the second embodiment, or the semiconductor package 120 may be manufactured by a compression molding method as in the first embodiment.

The release film should just be the release film of this invention, and is not limited to the release film (1). For example, you may use the release film 4.

The mold in the first embodiment is not limited to the mold shown in Fig. 5, and a mold known as a mold used in the compression molding method can be used. The mold in the second embodiment is not limited to the mold shown in Fig. 8, and a mold known as a mold used in the transfer method can be used.

A semiconductor package manufactured by the method for manufacturing a semiconductor package of the present invention is not limited to the semiconductor packages 110 and 120 . Depending on the semiconductor package to be manufactured, the steps (α6) to (α7) in the first embodiment may not be performed. For example, the shape of the resin sealing portion is not limited to that shown in Figs. 3 and 4, and may have a step or the like. The number of semiconductor elements sealed in the resin sealing portion may be one or plural. The ink layer is not essential. In the case of manufacturing a light emitting diode as a semiconductor package, since the resin encapsulation part also functions as a lens part, an ink layer is not normally formed on the surface of the resin encapsulation part. In the case of the lens portion, various lens shapes such as a substantially hemispherical shape, a shell shape, a Fresnel lens shape, a half-moon shaped fish cake shape, and a substantially hemispherical lens array shape can be employed as the shape of the resin encapsulation portion.

Example

Hereinafter, the present invention will be described in detail by showing examples. However, this invention is not limited by the following description.

Among Examples 1 to 18 described later, Examples 1 to 13 are examples, and Examples 14 to 18 are comparative examples.

The evaluation method and material used in each case are shown below.

〔Assessment Methods〕

(thickness)

The thickness (μm) of the substrate was measured in accordance with ISO 4591:1992 (Method for measuring thickness by B1 method of JIS K7130:1999, mass method of samples taken from plastic films or sheets).

The thickness (nm) of the antistatic layer was measured with a transmission infrared film thickness meter RX-100 (manufactured by Kurashiki Spinning Co., Ltd.).

(arithmetic mean roughness Ra)

Arithmetic average roughness Ra (μm) of the surface was measured based on JIS B0601:2013 (ISO 4287:1997, Amd.1:2009). The standard length lr (cutoff value λc) was 0.8 mm, and the measurement length was 8 mm. At the time of measurement, using SURFCOM 480A (manufactured by Tokyo Seiki Co., Ltd.), Ra was determined at 3 locations in the direction orthogonal to the flow direction at the time of film production and 6 locations in total, 3 locations in the parallel direction , and their average value was taken as Ra of the surface concerned.

(surface resistance value)

The surface resistance value (Ω/□) was measured in accordance with IEC 60093 and the double ring electrode method. As the measuring instrument, an ultra-high resistance meter R8340 (manufactured by Advantec) was used, and the measurement was performed at an applied voltage of 500 V and an applied time of 1 minute.

(Film electrification voltage after encapsulation (separation electrification after encapsulation))

The antistatic property of the release film at the time of peeling is confirmed by measuring the electrification voltage of the release film immediately after peeling.

A 100 μm-thick aluminum foil (JIS H4000: 2006 AlN30P) was cut into 13 cm × 13 cm and placed on a 13 cm × 13 cm first SUS plate. On it, a polyimide film (UPIREX 125S, manufactured by Ube Kogyo Co., Ltd.) having a thickness of 125 μm cut out from 10 cm × 12 cm to 8 cm × 10 cm was placed as a spacer. Further, an appropriate amount of Sumicon EME G770H typeF ver.GR (manufactured by Sumitomo Bakelite Co., Ltd.), an epoxy resin for semiconductor encapsulation, as a curable resin was applied to the cut-out portion of the polyimide film. On it, the release film cut into 13 cm × 13 cm was placed so that the antistatic layer side and the opposite surface contacted the curable resin after removing static electricity in advance. Finally, a second SUS plate of 13 cm x 13 cm was placed.

The sample produced in the above procedure was pressed with a press machine at a temperature of 180°C, a pressure of 1 MPa, and a time of 3 minutes. After taking out from the press machine, the whole was put on a 180 degreeC hot plate, and after removing the 2nd SUS board, the release film was peeled and peeled over 5 second.

The electrification voltage on the side of the peeled release film that was in contact with the curable resin was quickly measured. As the measurement instrument, a surface electrometer MP-520-1 (manufactured by Midori Safety Co., Ltd.) was used, and the distance between the release film and the measurement terminal was fixed at 3 cm. In addition, the measured value was obtained by rounding off the number of digits of 1 V (the upper measurement limit of the device is 2,000 V). The results were evaluated according to the following criteria.

A (good): 0 to 100 V.

B (available): 101 to 200 V.

× (poor): 201 V or more.

The above epoxy resin (Sumikon EME G770H type F ver.GR, manufactured by Sumitomo Bakelite Co., Ltd.) is granulated by pulverizing and mixing the following raw materials with a super mixer for 5 minutes.

Phenolene skeleton-containing phenol aralkyl type epoxy resin (Nippon Kayaku Co., Ltd., NC-3000. Softening point: 58°C, epoxy equivalent: 277.): 8 parts by mass.

Bisphenol A type epoxy resin (manufactured by Japan Epoxy Resin Co., Ltd., YL6810. Melting point 45°C, epoxy equivalent 172.): 2 parts by mass.

Phenolene skeleton-containing phenol aralkyl resin (manufactured by Mitsui Chemicals, Inc., XLC-4L. Softening point: 65°C, hydroxyl equivalent: 165): 2 parts by mass.

Phenol novolak resin (manufactured by Sumitomo Bakelite, PR-HF-3. Softening point: 80°C, hydroxyl equivalent: 105): 2 parts by mass.

Curing accelerator (triphenylphosphine): 0.2 parts by mass.

Inorganic filler (fused spherical silica having an average particle diameter of 16 μm): 84 parts by mass.

Carnaba Wax: 0.1 part by mass.

Carbon black: 0.3 part by mass.

Coupling agent (3-glycidoxypropyltrimethoxysilane): 0.2 part by mass.

(total light transmittance)

The total light transmittance (%) of the release film was measured using a haze meter NDH5000 (manufactured by Nippon Denshoku Industries, Ltd.) based on ISO 14782:1999.

(mold adsorption test)

Each release film having a width of 200 mm wound around a 3-inch plastic core was set in a transfer mold apparatus YPS60 (manufactured by TOWA). The release film is disposed so that the surface of the antistatic layer faces the mold surface (however, in the case of a release film without an antistatic layer, the surface with a large Ra is disposed so as to face the mold surface), and is sent out at 180°C. It was vacuum adsorbed on a heated mold. The positioning of the film transport direction and the direct direction at that time was automatically adjusted by a camera. After that, the release film was opened by releasing the vacuum, and the used release film was recovered and the unused release film was sent to the mold. These series of steps (vacuum adsorption, opening, film transfer) were repeated 100 times, and the number of adsorption errors due to misalignment of the release film was measured. The results were evaluated according to the following criteria.

A (good): 0 times.

× (bad): 1 or more times.

(charged voltage when adsorbing mold)

By measuring the charging voltage of the release film when the release film adsorbs to the mold, the antistatic property of the release film at the time of contact between the semiconductor element and the release film is confirmed.

In the mold adsorption test described above, the charging voltage when the release film adsorbed to the mold was measured with a contact type surface electrometer MODEL821HH (manufactured by Trek Japan).

(Mold blocking test)

Except that the mold temperature was set to 175 ° C. and the cavity was set to a width of 70 mm, a length of 200 mm and a depth of 0.5 mm, vacuum adsorption of the release film, opening, and film transfer were repeated 100 times in the same manner as in the mold adsorption test described above. , The number of times wrinkles occurred on the release film during mold adsorption was counted. The results were evaluated according to the following criteria.

A (good): 0 times.

B (possible): 1 to 5 times.

× (bad): more than 5 times.

[Materials used]

(releasability description)

ETFE Film 1:

Fluon (registered trademark) ETFE C-88AXP (manufactured by Asahi Glass Co., Ltd.) is fed to an extruder equipped with a T die, and taken between a pressure roll having irregularities on the surface and a mirror-finished metal roll to obtain a film having a thickness of 50 μm. was unveiled. The temperatures of the extruder and the T die were 320°C, and the temperatures of the pressure roll and metal roll were 100°C.

Ra of the surface of the obtained film was 2.0 µm on the pressure roll side and 0.2 µm on the mirror surface side. The antistatic liquid coated surface was subjected to corona treatment so that the wetting tension based on ISO 8296: 1987 (JIS K6768: 1999) was 40 mN/m or more.

In addition, the "antistatic liquid coated surface" of a film is a surface coated with antistatic liquid, and is a surface having a "coated surface Ra" shown in Tables 1 to 3 described later.

ETFE Film 2:

Fluon (registered trademark) ETFE C-88AXP (manufactured by Asahi Glass Co., Ltd.) is fed to an extruder equipped with a T die, and taken between a pressure roll having irregularities on the surface and a mirror-finished metal roll to obtain a film having a thickness of 50 μm. was unveiled. The temperatures of the extruder and the T die were 320°C, and the temperatures of the pressure roll and metal roll were 50°C.

Ra of the surface of the obtained film was 1.3 µm on the pressure roll side and 0.1 µm on the mirror surface side. The antistatic solution-coated surface was subjected to corona treatment in the same manner as in the ETFE film 1.

ETFE Film 3:

Fluon (registered trademark) ETFE C-88AXP (manufactured by Asahi Glass Co., Ltd.) was fed to an extruder equipped with a T die, and was taken between a pressure roll having irregularities on the surface and a mirror-finished metal roll to obtain a film having a thickness of 100 μm. was unveiled. The temperatures of the extruder and the T die were 320°C, and the temperatures of the pressure roll and metal roll were 100°C.

Ra of the surface of the obtained film was 2.2 µm on the pressure roll side and 0.3 µm on the mirror surface side. The antistatic solution-coated surface was subjected to corona treatment in the same manner as in the ETFE film 1.

ETFE Film 4:

Fluon (registered trademark) ETFE C-88AXP (manufactured by Asahi Glass Co., Ltd.) is fed to an extruder equipped with a T die, and taken between a pressure roll having irregularities on the surface and a mirror-finished metal roll to obtain a film having a thickness of 50 μm. was unveiled. The temperatures of the extruder and the T die were 330°C, and the temperatures of the pressure roll and metal roll were 150°C.

Ra of the surface of the obtained film was 2.7 µm on the pressure roll side and 0.3 µm on the mirror surface side. The antistatic solution-coated surface was subjected to corona treatment in the same manner as in the ETFE film 1.

LM-ETFE Film:

Fluon (registered trademark) LM-ETFE LM-720AP (manufactured by Asahi Glass Co., Ltd.) was fed to an extruder equipped with a T die, and was picked up between a pressure roll having irregularities on the surface and a mirror-finished metal roll to obtain a thickness of 50 μm. A film of was formed. The temperatures of the extruder and the T die were 320°C, and the temperatures of the pressure roll and metal roll were 100°C.

Ra of the surface of the obtained film was 2.0 µm on the pressure roll side and 0.2 µm on the mirror surface side. The antistatic solution-coated surface was subjected to corona treatment in the same manner as in the ETFE film 1.

PMP (Polymethylpentene) Film:

TPX (registered trademark) MX004 (manufactured by Mitsui Chemicals, Inc.) was fed into an extruder equipped with a T die, and held between a pressure roll having irregularities on the surface and a mirror-finished metal roll to form a film having a thickness of 50 μm. The temperatures of the extruder and the T-die were 300°C, and the temperatures of the pressure roll and metal roll were 100°C.

Ra of the surface of the obtained film was 2.0 µm on the pressure roll side and 0.2 µm on the mirror surface side.

SPS (Syndiotactic Polystyrene) Film:

Zarek (registered trademark) 142ZE (manufactured by Idemitsu Kosan Co., Ltd.) is fed into an extruder equipped with a T die, taken between mirror-finished metal rolls, and stretched simultaneously in the flow direction of the film and in the direction orthogonal to the flow direction Thus, a film having a thickness of 50 µm was formed. The temperature of the extruder and the T die was 270°C, the temperature of the cooling roll was 100°C, the drawing temperature was 115°C, the draw ratio was 3.3 times in both the flow direction and the direction perpendicular to the flow direction, and the drawing speed was 500%/min. In addition, heat treatment was performed at 215°C after the stretching step. Further, in order to form irregularities on one side of the film, a so-called sand mat treatment in which sand is sprayed was performed.

Ra of the surface of the obtained film was 1.3 µm on the sand mat-treated surface and 0.1 µm on the untreated surface. Corona treatment was applied to the surface coated with the antistatic solution so that the wetting tension based on ISO8296:1987 (JIS K6768:1999) was 40 mN/m or more.

Silicone Coated PET Film:

An NS separator MA100 (manufactured by Nakamoto Fax, 100 µm in thickness) was used. In this film, a silicone coating layer with releasability was formed on one side of a PET film, and the thickness of the silicone coating layer was 5 μm.

TPU (polyurethane elastomer) film with release layer:

3-(2-perfluorohexylethoxy)-1,2-dihydroxypropane (trade name: Eptop (registered Trademark) MF100) was added, and fed into an extruder equipped with a T die to extrude, and in the take-up machine, from the pressure roll side, a matte processing PET film was used as a separator, and a mirror-finished PET film was used as a separator from the metal cooling roll side. and cooled by sandwiching them between a pressure roll and a metal cooling roll. The temperature of the extruder and the T-die was 220°C, and the temperature of the roll was 50°C. Thereafter, the film was aged at 80°C for 24 hours and then at 40°C for 150 hours, and then the PET separators on both sides were peeled off. The thickness of the film was 50 μm.

Subsequently, the release layer material described below was coated on the surface to which the mirror-finished PET film was adhered, and dried to form a release layer having a thickness of 1 μm, thereby obtaining a TPU film with a release layer. Coating was performed by the gravure coat method. Drying was performed by blowing hot air.

Material for release layer: Fluorine-containing copolymer F Clear (registered trademark) KD270 (manufactured by Kanto Denka Kogyo Co., Ltd.) containing reactive silicone as a copolymerization unit, and hexamethylene diisocyanate-based isocyanurate-type compound Duranate (registered trademark) TSE- What was diluted with ethyl acetate so that 100 (made by Asahi Kasei Co., Ltd.) might be mixed so that NCO/OH ratio might become 1, and solid content concentration might become 7 mass %.

Ra of the surface of the obtained film was 2.1 µm on the matt-processed PET film adhered surface and 0.2 µm on the mirror-finished PET film adhered surface (release surface).

(material for antistatic layer)

Antistatic fluid 1:

Each of the following materials (mass of the solid content by side) was mixed. The obtained mixture was diluted with a mixed solvent of methyl ethyl ketone/toluene = 1/1 (mass ratio) so as to have a solid content of 5% by mass, and antistatic liquid 1 was obtained.

2 parts of polypyrrole-based conductive polymer dispersion CDP-310M (solid content: 5% by mass, manufactured by Carit Corporation, Nippon).

Acrylic resin Teisan Resin (registered trademark) WS-023 (solid content: 30% by mass, manufactured by Nagase ChemteX Co., Ltd.) 10 parts.

Isocyanate-based curing agent Coronate (registered trademark) L (solid content 70% by mass, manufactured by Nippon Polyurethane Industry Co., Ltd.) 0.5 part.

Antistatic fluid 2:

Each of the following materials (mass of the solid content by side) was mixed. The obtained mixture was diluted with a mixed solvent of isopropanol/toluene/water = 50/40/10 (mass ratio) so as to have a solid content of 5% by mass, and antistatic liquid 2 was obtained.

Conductive tin oxide sol (indoped tin oxide) Cellnax (registered trademark) CX-S204IP (solid content 20% by mass, manufactured by Nissan Chemical Industries, Ltd.) 2 copies.

Polyamide resin macromelt 6827 (pellet, manufactured by Henkel) 5 parts.

Antistatic liquid 3:

Each of the following materials (mass of the liquid to be crushed) was mixed. The obtained mixture was diluted with a mixed solvent of isopropanol/toluene/water = 50/40/10 (mass ratio) so as to have a solid content of 5% by mass, and antistatic liquid 2 was obtained.

Acrylic resin-containing polythiophene-based conductive polymer dispersion Aracoat (registered trademark) AS601D (solid content: 4% by mass, manufactured by Arakawa Chemical Industry Co., Ltd.) 10 parts.

Polyfunctional aziridine compound curing agent Aracoat CL910 (solid content: 10% by mass, manufactured by Arakawa Chemical Industry Co., Ltd.) 1 part.

Antistatic solution 4:

Each of the following materials (mass of the solid content by side) was mixed. The obtained mixture was diluted with ethyl acetate so that it might become 5 mass % of solid content, and the antistatic liquid 4 was obtained.

Polyaniline-based conductive polymer dispersion liquid CORERON YE (solid content 10% by mass, manufactured by Porymerits Corporation) 2 parts.

Polyester resin Polyester (registered trademark) SP181 (pellets, manufactured by Nippon Synthetic Chemical Co., Ltd.) 5 parts.

Isocyanate-based curing agent, Coronate L (70% by mass of solid content, manufactured by Nippon Polyurethane Industry Co., Ltd.) 0.5 part.

Antistatic liquid 5:

Silicone resin-containing, polythiophene-based conductive polymer paint Sepulida (registered trademark) AS-F (solid content: 15% by mass, manufactured by Shin-Etsu Polymer Co., Ltd.) was diluted with methyl ethyl ketone to have a solid content of 3% by mass, and the antistatic solution got 5

Antistatic solution 6:

Each of the following materials (mass of the liquid to be crushed) was mixed. The obtained mixture was diluted with a mixed solvent of isopropanol/water = 40/30 (mass ratio) so as to have a solid content of 7% by mass, and antistatic liquid 6 was obtained.

Quaternary ammonium salt monomer-containing acrylic resin Bondip (registered trademark) PA100 main agent (solid content 30% by mass, manufactured by Konishi Co., Ltd.) 1 part.

Amine type curing agent Bondip PA100 curing agent (solid content 10% by mass, manufactured by Konishi) 1 part.

Antistatic liquid 7:

Each of the following materials (mass of the solid content by side) was mixed. The obtained mixture was diluted with ethyl acetate so that it might become 5 mass % of solid content, and the antistatic liquid 7 was obtained.

Carbon Black 1.3 parts.

Polyester resin Polyester MSP640 (pellet, manufactured by Nippon Synthetic Chemical Co., Ltd.) 5 parts.

Isocyanate-based curing agent Coronate L (Nippon Polyurethane Industry Co., Ltd.) 0.5 part.

[Example 1]

Antistatic liquid 1 was applied to the surface of ETFE film 1 on the Ra 0.2 μm side using a gravure coater, and dried to form an antistatic layer having a thickness of 200 nm. Coating was carried out by a direct gravure method using a 100 mm x 250 mm wide lattice 150# roll with a depth of 40 µm as a gravure plate, and the coating speed was 4 m/min. Drying was carried out at 100°C for 1 minute through a roll support drying furnace at an air volume of 15 m/sec. Then, curing was carried out in a 40°C oven for 3 days to obtain a release film.

[Examples 2 to 13, Examples 15 to 17]

A release film was obtained in the same manner as in Example 1 except that the type of antistatic liquid, the coated surface of the releasable substrate, the type of the releasable substrate, or the thickness of the antistatic layer were changed as described in Tables 1 to 3.

[Example 14]

ETFE Film 1 was used as the release film of Example 14 as it was.

[Example 18]

Each of the following materials (mass of the solid content by side) was mixed. The resulting mixture was diluted with a mixed solvent of methyl ethyl ketone/toluene = 1/1 (mass ratio) to a solid content of 5% by mass to obtain overcoat liquid 1 (a liquid having a composition obtained by removing the polypyrrole dispersion liquid from antistatic liquid 1).

Acrylic resin Teisan Resin WS-023 (manufactured by Nagase Chemtex Co., Ltd.) 10 copies.

Coronate L (manufactured by Nippon Polyurethane Industry Co., Ltd.) 0.5 part.

After forming an antistatic layer on the ETFE film 1 in the same manner as in Example 1, the overcoat liquid 1 was further applied thereon using a gravure coater and dried to form an overcoat layer having a thickness of 2 μm. Drying was performed by blowing hot air. Then, curing was carried out in a 40°C oven for 3 days to obtain a release film.

For the release films of Examples 1 to 18, the type and thickness of the release base material used, the Ra of the coated surface, the type of antistatic liquid, the thickness of the antistatic layer, and the surface resistance of the release film on the antistatic layer side (Only in Example 18, the overcoat layer side) Tables 1 to 3 show the values, film charging voltage after sealing, total light transmittance, mold adsorption test results, mold adsorption voltage, and mold blocking test results.

About the release films of Examples 1-13 and Examples 15-17, when Ra of the surface by the antistatic layer side was measured, it was the same as Ra of the coated surface of the release property base material.

As shown in the above results, the release films of Examples 1 to 13 had a low surface resistance value on the antistatic layer side, an electrification voltage at the time of mold adsorption was zero, and had an excellent antistatic effect. In addition, the film charge voltage after sealing was low, and a sufficiently excellent antistatic action was maintained even after exposure to high temperatures.

In addition, since the release films of Examples 1 to 13 had a total light transmittance of 80% or more and were excellent in transparency, adsorption errors did not occur in the mold adsorption test.

In addition, in the release films of Examples 1 to 13, the number of wrinkles generated in the release film during adsorption to the mold was small, and in particular, the number of wrinkles on the antistatic layer side surface Ra was 0.2 to 2.5 μm, the number of times was zero.

On the other hand, the release film of Example 14 having no antistatic layer had insufficient antistatic action.

The release film of Example 15, in which the antistatic agent is a quaternary ammonium salt-containing acrylic resin, had excellent antistatic action immediately after production, but the film electrification voltage after sealing was high and the antistatic action was greatly reduced by high temperature. This is based on the principle that the antistatic action of a cationic antistatic agent containing a quaternary ammonium salt group adsorbs moisture in the air and releases an electric charge, and in a high temperature environment of 150 ° C. or higher, which is the sealing temperature of a semiconductor element, adsorbs It is thought that this is because the existing moisture is desorbed and the electric charge cannot be released.

Since the release films of Examples 16 to 17 having a total light transmittance of less than 80% had low transparency, adsorption errors occurred in the mold adsorption test. Although the antistatic layer of Example 17 used the same liquid as the antistatic layer of Example 1, it is considered that the transmittance was low because the thickness of the antistatic layer was as thick as 500 nm.

The release film of Example 18, in which an overcoat layer was formed on the antistatic layer and the antistatic layer did not directly contact the mold, had the same surface resistance value as Example 10, but the charge voltage at the time of adsorption to the mold was 90 V. This is considered to be because the stagnant charge did not spread quickly.

In addition, all the content of the JP Patent application 2014-248936, the claim, the abstract, and drawing for which it applied on December 9, 2014 is referred here, and it takes in as an indication of the specification of this invention.

1: release film
2: releasable substrate
3: antistatic layer
4: release film
5: releasable substrate
5A: substrate body
5B: release layer
10: Substrate
12: semiconductor chip
14: resin encapsulation
14a: upper surface of the resin sealing portion 14
16: ink layer
18: bonding wire
20: fixed hieroglyph
22: cavity bottom member
24: movable lower mold
26: Cavity
40: curable resin
50: hieroglyph
52: lower brother
54: Cavity
56: cavity surface
58: board installation part
60: resin inlet
62: resin placement unit
64: plunger
70: Substrate
72: semiconductor chip
74: underfill (resin encapsulation part)
76: hardened material
110: semiconductor package
120: semiconductor package

Claims (15)

In the manufacture of a semiconductor package in which a semiconductor element is placed in a mold and sealed with a curable resin to form a resin encapsulation, a release film disposed on a surface in contact with the curable resin of the mold,
A releasable substrate in contact with a curable resin when forming a resin encapsulation portion, and an antistatic layer in contact with a mold when forming the resin encapsulation portion,
The antistatic layer contains at least one antistatic agent selected from the group consisting of conductive polymers and conductive metal oxides, and the arithmetic average roughness Ra of the antistatic layer-side surface is 0.2 to 2.5 μm,
A release film characterized by having a total light transmittance of 80% or more. According to claim 1,
The release film whose film electrification voltage after sealing measured by the following measuring method is 200 V or less.
(Method of measuring film electrification voltage after sealing)
A 13 cm × 13 cm, 100 μm thick aluminum foil (JIS H4000: 2006 AlN30P) was placed on a 13 cm × 13 cm first stainless steel plate, and a 10 cm × 12 cm, 125 μm thick aluminum foil was placed thereon as a spacer. The center of the polyimide film was cut out to a size of 8 cm × 10 cm, and further, an epoxy resin for semiconductor encapsulation as a curing resin was placed on the cut out portion of the polyimide film, Sumikon EME G770H typeF ver.GR (Sumitomo Bakelite Co., Ltd. prepared) sprinkled with 2.7 g. On top of that, the release film of 13 cm x 13 cm is charged in advance, and then the antistatic layer side and the opposite surface are placed in contact with the curable resin, and a second stainless steel plate of 13 cm x 13 cm is placed thereon is added to make a sample.
The sample prepared in the above procedure is pressed with a press machine at a temperature of 180 ° C., a pressure of 1 MPa, and a time of 3 minutes, and after taking it out of the press machine, the whole is placed on a hot plate at 180 ° C., and after removing the second stainless steel plate, release The film is peeled off over 5 seconds. Within 5 seconds after that, the electrostatic voltage on the side of the peeled release film that was in contact with the curable resin is measured using a surface electrometer while fixing the distance between the release film and the measurement terminal to 3 cm. According to claim 1 or 2,
The surface resistance value of the antistatic layer is 10 ¹⁰ Ω/□ or less, the release film. delete According to claim 1 or 2,
A release film in which the antistatic layer has a thickness of 100 to 1,000 nm. According to claim 1 or 2,
The release film in which the said antistatic layer contains the said antistatic agent and a resin binder. According to claim 6,
The resin binder is an acrylic resin, a silicone resin, a urethane resin, a polyester resin, a polyamide resin, a vinyl acetate resin, an ethylene-vinyl acetate copolymer, an ethylene-vinyl alcohol copolymer, and a chlorotrifluoroethylene-vinyl alcohol copolymer and a release film comprising at least one member selected from the group consisting of tetrafluoroethylene-vinyl alcohol copolymer. According to claim 6,
The release film whose content of the said antistatic agent is 3-50 mass % with respect to the said resin binder. According to claim 1 or 2,
The release film whose arithmetic average roughness Ra of the surface on the side of the release property base material is 0.1-2.5 micrometers. According to claim 1 or 2,
A release film in which the thickness of the release substrate is 12 to 100 μm. According to claim 1 or 2,
The release film in which the releasable substrate is made of a transparent resin body of a single layer or multilayer structure, and a layer constituting a surface in contact with at least a curable resin is made of a releasable transparent resin. According to claim 11,
The release film in which the release substrate is a single layer structure made of a release release transparent resin. According to claim 11,
The release film, wherein the release-resistant transparent resin is a fluororesin, polymethylpentene, syndiotactic polystyrene, or silicone resin. According to claim 11,
The release film, wherein the transparent resin with release property is an ethylene-tetrafluoroethylene copolymer. A method for manufacturing a semiconductor package having a semiconductor element and a resin sealing portion made of a cured curable resin for sealing the semiconductor element, comprising:
A step of disposing the release film according to claim 1 or 2 on the surface of the mold in contact with the curable resin;
A step of arranging a substrate on which a semiconductor element is mounted in the mold, filling a space in the mold with a curable resin and curing to form a resin encapsulation portion, thereby obtaining an encapsulated body having the substrate on which the semiconductor element is mounted and the resin encapsulation portion;
A method for manufacturing a semiconductor package, comprising a step of releasing the encapsulated body from the mold.

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