JP6928924B2 - Release film for process, its application, and manufacturing method of resin-sealed semiconductor using it - Google Patents

Description

The present invention relates to a release film for a process, preferably a release film for a semiconductor encapsulation process, and particularly when a semiconductor chip or the like is placed in a mold and a resin is injected and molded, the semiconductor chip or the like and the inner surface of the mold are formed. The present invention relates to a release film for a process arranged between and, and a method for manufacturing a resin-sealed semiconductor using the same.

In recent years, it has been studied to reduce the amount of sealing resin used as the size and weight of semiconductor packages and the like are reduced. It is desired to reduce the amount of mold release agent contained in the sealing resin so that the interface between the semiconductor chip or the like and the resin can be firmly adhered even if the amount of the sealing resin used is reduced. .. Therefore, as a method of obtaining the mold releasability between the sealing resin and the mold after curing and molding, a method of arranging a mold releasable film between the inner surface of the mold and a semiconductor chip or the like is adopted.

Examples of such a release film include a fluorine-based resin film (for example, Patent Documents 1 and 2) and a poly-4-methyl-1-pentene resin film (for example, Patent Document 3), which are excellent in releasability and heat resistance. Proposed. However, these release films have a problem that wrinkles are likely to occur when they are attached to the inner surface of the mold, and these wrinkles are transferred to the surface of the molded product, resulting in poor appearance.

On the other hand, a laminated release film having a release layer and a heat-resistant layer has been proposed. These release films are intended to obtain releasability in the release layer and to suppress wrinkles in the heat resistant layer. A typical example of these proposals focuses on the relationship between the storage elastic modulus of the release layer and the heat-resistant layer (see, for example, Patent Documents 4 and 5). For example, Patent Document 4 describes a laminated release film having a structure in which the storage elastic modulus of the release layer is relatively low and the storage elastic modulus of the heat-resistant layer is relatively high, more specifically, at 175 ° C. of the release layer. A release film for a semiconductor encapsulation process is described in which the storage elastic modulus E'is 45 MPa or more and 105 MPa or less, and the heat-resistant layer has a storage elastic modulus E'at 100 MPa or more and 250 MPa or less at 175 ° C.

However, with the development of the technical field, the required level for process release films such as release films for semiconductor encapsulation processes is increasing year by year, and process release in which wrinkles are suppressed even under more severe process conditions. A mold film is required, and in particular, a mold release film for a process in which mold releasability, wrinkle suppression, and mold followability are balanced at a higher level is strongly demanded.
Further, depending on the type of semiconductor encapsulating resin, a low molecular weight gas (hereinafter referred to as “out gas”) such as an oligomer generated from the encapsulating resin heated during molding permeates the release film and contaminates the mold. May occur, and its suppression has been sought. In particular, when wrinkles occur in the release film for the semiconductor encapsulation process, for example, when a release film having an inorganic film or an organic film is used for the gas permeation suppression layer, the gas permeation suppression layer itself is thinner than the film. Therefore, when the release film is wrinkled, the gas permeation suppressing layer is liable to crack, tear, or have holes. As a result, outgas may permeate the film from a portion where holes or the like are likely to be generated from the sealing resin generated by heating and accumulate on the mold surface, and local mold contamination may occur remarkably. Since the film may be wrinkled easily due to the progress of contamination of the mold, the cleaning cycle of the mold is shortened, so that the production efficiency of the semiconductor packaging process is lowered and the manufacturing cost is considered. Prevention of mold contamination was required. (See, for example, Patent Document 6.)

Japanese Unexamined Patent Publication No. 2001-310336 JP-A-2002-110722 Japanese Unexamined Patent Publication No. 2002-361643 Japanese Unexamined Patent Publication No. 2010-208104 International Publication No. 2015/133631 A1 Pamphlet International Publication No. 2007/125834 A1 Pamphlet

The present invention has been made in view of such circumstances, and a molded product after resin sealing can be easily released without depending on the mold structure and the amount of mold release agent, and the appearance such as wrinkles and chips can be easily removed. It is an object of the present invention to provide a mold release film for a process, which can obtain a molded product without defects and can effectively suppress contamination of a mold.

As a result of diligent studies to solve the above problems, the present inventors have found that the rate of change in thermal dimensions of the process release film at a specific temperature, particularly the TD direction of the laminated film constituting the process release film (film). The rate of change in thermal dimensions in the in-plane direction perpendicular to the longitudinal direction of the film during production; hereinafter also referred to as the "lateral direction") is appropriately controlled, and the oxygen permeability of the laminated film is controlled. As a result, the outgas permeability of the sealing resin of the laminated film can be controlled to a predetermined value or less by controlling the temperature to a predetermined value or less. We have found that it is important to control the contamination of the mold, and have completed the present invention.
That is, the present invention and each aspect thereof are as described in the following [1] to [17].

[1]
A release film for a process, which is a laminated film containing a release layer A and a heat-resistant resin layer B.
The contact angle of the release layer A with water is 90 ° to 130 °.
The rate of change in thermal dimensions from 23 ° C to 120 ° C in the lateral (TD) direction of the laminated film is 3% or less.
According to JIS K 7126 of the laminated film, the temperature is 20 ° C. and the humidity is 50%. H. A release film for a process in which the oxygen permeability measured under the above conditions is 1000 ml / m2, day, MPa or less.
[2]
A release film for a process, which is a laminated film containing a release layer A and a heat-resistant resin layer B.
The contact angle of the release layer A with water is 90 ° to 130 °.
The rate of change in thermal dimensions from 23 ° C to 120 ° C in the lateral (TD) direction of the laminated film is 3% or less.
The release film for the process having an outgas permeability of 1.0% by weight or less measured according to the following procedures (1) to (3) of the laminated film:
(1) Put 10 mg of the sealing resin in the vial 1, seal it with a cap and a rubber stopper, heat it at 120 ° C. for 30 minutes, perform GC-MS measurement by the static headspace method, and outgas in the vial 1. Measure quantity 1;
(2) Put 10 mg of the sealing resin in the vial bottle 1, prepare a seal that covers the mouth of the vial bottle 1 with a release film for processing and seal it tightly, and then the size that the vial bottle 1 can be inserted. The vial bottle 2 of the above is prepared, the vial bottle 1 is stored in the vial bottle 2, and after sealing with a cap and a rubber stopper, the mixture is heated at 120 ° C. for 30 minutes and GC-MS measurement is performed by the static headspace method. Measure the amount of outgas 2 in the vial 2 permeated with the release film for the process;
(3) The outgas permeability of the release film for the process is calculated according to the following (Equation 1).
Outgas permeability = Outgas amount 2 / Outgas amount 1 x 100 (% by weight) (Equation 1)
[3]
The sum of the thermal dimensional change rate from 23 ° C. to 120 ° C. in the lateral (TD) direction and the thermal dimensional change rate from 23 ° C. to 120 ° C. in the longitudinal (MD) direction of the laminated film is 6% or less [1]. ] Or the release film for the process according to [2].
[4]
The process release film according to any one of [1] to [3], wherein the heat-resistant resin layer B has a thermal dimensional change rate of 3% or less from 23 ° C. to 120 ° C. in the lateral (TD) direction. ..
[5]
The sum of the thermal dimensional change rate from 23 ° C. to 120 ° C. in the lateral (TD) direction and the thermal dimensional change rate from 23 ° C. to 120 ° C. in the longitudinal (MD) direction of the heat-resistant resin layer B is 6% or less. The release film for the process according to [4].
[6]
In any one of [1] to [5], the release layer A contains a resin selected from the group consisting of a fluororesin, a 4-methyl-1-pentene (co) polymer, and a polystyrene-based resin. The release film for the described process.
[7]
The release film for a process according to any one of [1] to [6], wherein the gas barrier layer C is laminated on the heat-resistant resin layer B.
[8]
The process release film according to [7], wherein the gas barrier layer C is an inorganic layer or an organic layer.
[9]
The release film for a process according to [7] or [8], wherein the protective resin layer D, which is an organic coating, is laminated on the gas barrier layer C.
[10]
The amount of heat of crystal melting in the first heating step measured by differential scanning calorimetry (DSC) according to JIS K7221 of the heat-resistant resin layer B is 15 J / g or more and 60 J / g or less, according to [1] to [9]. The release film for the process according to any one item.
[11]
The laminated film further has a release layer A', and includes the release layer A, the heat-resistant resin layer B, and the release layer A'in this order.
The process release film according to any one of [1] to [10], wherein the release layer A'has a contact angle with water of 90 ° to 130 °.
[12]
At least one of the release layer A and the release layer A'contains a resin selected from the group consisting of a fluororesin, a 4-methyl-1-pentene (co) polymer, and a polystyrene-based resin [11]. The release film for the process described in.
[13]
The process release film [14] according to any one of [1] to [12], which is used in the sealing process using a thermosetting resin.
The process release film according to any one of [1] to [13], which is used in a semiconductor encapsulation process.
[15]
The process release film according to any one of [1] to [12], which is used in a fiber reinforced plastic molding process or a plastic lens molding process.
[16]
A method for manufacturing resin-sealed semiconductors.
The process of arranging the resin-sealed semiconductor device at a predetermined position in the molding die, and
A step of arranging the process release film according to any one of [1] to [14] on the inner surface of the molding die so that the release layer A faces the semiconductor device.
A step of injecting and molding a sealing resin between the semiconductor device and the process release film after molding the molding die.
The above-mentioned method for manufacturing a resin-sealed semiconductor.
[17]
A method for manufacturing resin-sealed semiconductors.
The process of arranging the resin-sealed semiconductor device at a predetermined position in the molding die, and
A step of arranging the process release film according to [11] or [12] on the inner surface of the molding die so that the release layer A'is opposed to the semiconductor device.
A step of injecting and molding a sealing resin between the semiconductor device and the process release film after molding the molding die.
The above-mentioned method for manufacturing a resin-sealed semiconductor.

The process release film of the present invention has a high level of releasability, wrinkle suppression, and mold followability that could not be realized by the prior art, and can effectively suppress mold contamination. By using the above, a molded product obtained by sealing a semiconductor chip or the like with a resin can be easily released, and a molded product having no appearance defects such as wrinkles and chips can be manufactured with high productivity and low cost. Can be done.

It is a schematic diagram which shows an example of the release film for process of this invention. It is a schematic diagram which shows another example of the release film for process of this invention. It is a schematic diagram which shows another example of the release film for process of this invention. It is a schematic diagram which shows another example of the release film for process of this invention. It is a schematic diagram which shows an example of the manufacturing method of the resin-sealed semiconductor using the release film for process of this invention. It is a schematic diagram which shows an example of the manufacturing method of the resin-sealed semiconductor using the release film for process of this invention. It is a schematic diagram which shows an example of the manufacturing method of the resin-sealed semiconductor using the release film for process of this invention. It is a schematic diagram which shows an example of the resin-sealed semiconductor obtained by the manufacturing method of the resin-sealed semiconductor of FIG. 6A and FIG. 6B. It is a schematic diagram which shows the arrangement at the time of the evaluation of mold contamination. It is a schematic diagram which shows the arrangement at the time of measuring the outgas permeability.

Release film for process The release film for process of the present invention includes the following two aspects.
(First aspect)
A release film for a process, which is a laminated film containing a release layer A and a heat-resistant resin layer B.
The contact angle of the release layer A with water is 90 ° to 130 °.
The rate of change in thermal dimensions from 23 ° C to 120 ° C in the lateral (TD) direction of the laminated film is 3% or less.
The release film for the process, wherein the oxygen permeability of the laminated film is 1000 ml / m ² , day, MPa or less. The oxygen permeability in the present invention is based on JIS K 7126 using OX-TRAN2 / 21ML manufactured by Mocon Co., Ltd., and has a temperature of 20 ° C. and a humidity of 50% R.I. H. Oxygen permeability measured under the conditions of.
The oxygen permeability, from the viewpoint of effectively preventing the mold contamination, more preferably at most ^{500ml / m 2 · day · MPa} , and particularly preferably not more than ^{250ml / m 2 · day · MPa} .
It is preferable that the first aspect further satisfies the following conditions.
A release film for a process, which is a laminated film containing a release layer A and a heat-resistant resin layer B.
The contact angle of the release layer A with water is 90 ° to 130 °.
The release film for a process, which has a thermal dimensional change rate of 4% or less from 23 ° C. to 170 ° C. in the lateral (TD) direction of the laminated film.
(Second aspect)
A release film for a process, which is a laminated film containing a release layer A and a heat-resistant resin layer B.
The contact angles of the release layer A and the release layer A'with respect to water are 90 ° to 130 °.
The rate of change in thermal dimensions from 23 ° C to 120 ° C in the lateral (TD) direction of the laminated film is 3% or less.
The release film for the process, wherein the outgas permeability of the laminated film measured by the method described later is 1.0% by weight or less.
The outgas permeability is preferably 0.8% by weight or less, more preferably 0.7% by weight or less, and less than 0.5% by weight from the viewpoint of effectively preventing mold contamination. It is particularly preferable to have.
It is preferable that the second aspect further satisfies the following conditions.
A release film for a process, which is a laminated film containing a release layer A and a heat-resistant resin layer B.
The contact angle of the release layer A with water is 90 ° to 130 °.
The release film for a process, which has a thermal dimensional change rate of 4% or less from 23 ° C. to 170 ° C. in the lateral (TD) direction of the laminated film.
The first correspondence and the second aspect may further have a release layer A', and may include the release layer A, the heat-resistant resin layer B, and the release layer A'in this order. ..

As is clear from each of the above aspects, the process release film of the present invention (hereinafter, also simply referred to as “release film”) is a release layer A having mold releasability for a molded product or a mold, and optionally. It is a laminated film including a release layer A'and a heat-resistant resin layer B that supports the release layer.

The process release film of the present invention is arranged on the inner surface of the molding die when the semiconductor element or the like is resin-sealed inside the molding die. At this time, the release layer A of the release film (which may be the release layer A'if the release layer A'is present) is placed on the resin-sealed semiconductor element or the like (molded product) side. It is preferable to arrange it. By arranging the release film of the present invention, the resin-sealed semiconductor element or the like can be easily released from the mold.
The contact angle of the release layer A with water is 90 ° to 130 °, and by having such a contact angle, the release layer A has low wettability and adheres to the cured sealing resin or mold surface. The molded product can be easily released without any need.
The contact angle of the release layer A with water is preferably 95 ° to 120 °, more preferably 98 ° to 115 °, and even more preferably 100 ° to 110 °.

As described above, since the release layer A (in some cases, the release layer A') is arranged on the molded product side, wrinkles in the release layer A (in some cases, the release layer A') in the resin sealing step. It is preferable to suppress the occurrence of. This is because there is a high possibility that the generated wrinkles are transferred to the molded product and the appearance of the molded product is deteriorated.

In the present invention, in order to achieve the above object, the release layer A (and, if desired, the release layer A') and the heat-resistant resin supporting the release layer are used as the laminated film constituting the release film for the process. A laminated film including the layer B, wherein the rate of change in thermal dimension in the lateral (TD) direction shows a specific value is used.
That is, the laminated film containing the release layer A (and, if desired, the release layer A') and the heat-resistant resin layer B supporting the release layer is from 23 ° C. to 120 ° C. in the TD direction (horizontal direction). The rate of change in thermal dimensions is 3% or less. Further, it is preferable that the rate of change in thermal dimensions from 23 ° C. to 170 ° C. in the TD direction (horizontal direction) is 4% or less.
The thermal dimensional change rate from 23 ° C. to 120 ° C. in the TD direction (horizontal direction) of the laminated film is 3% or less, and more preferably, the thermal dimensional change from 23 ° C. to 170 ° C. in the TD direction (horizontal direction). When the rate is 4% or less, the occurrence of wrinkles in the release layer in the resin sealing step or the like can be effectively suppressed. The mechanism by which the generation of wrinkles in the release layer is suppressed by using a laminated film that constitutes the release film for the process and whose thermal dimensional change rate in the lateral (TD) direction shows the above specific value is not always clear. Although not, it is related to the fact that the thermal expansion / contraction of the release layer A (or the release layer A') due to heating / cooling during the process is suppressed by using the laminated film having a relatively small thermal expansion / contraction. It is presumed that there is.

The laminated film constituting the process release film of the present invention preferably has a thermal dimensional change rate of 2.5% or less, preferably 2.0%, from 23 ° C. to 120 ° C. in the TD direction (horizontal direction). It is more preferably less than or equal to, and even more preferably 1.5% or less. On the other hand, the laminated film preferably has a thermal dimensional change rate of −5.0% or more from 23 ° C. to 120 ° C. in the TD direction (horizontal direction).
The laminated film constituting the process release film of the present invention preferably has a thermal dimensional change rate of 3.5% or less, preferably 3.0%, from 23 ° C. to 170 ° C. in the TD direction (horizontal direction). It is more preferably less than or equal to, and even more preferably 2.0% or less. On the other hand, the laminated film preferably has a thermal dimensional change rate of −5.0% or more from 23 ° C. to 170 ° C. in the TD direction (horizontal direction).

The process release film of the present invention, which is a laminated film containing a release layer A (and, if desired, a release layer A') and a heat-resistant resin layer B that supports the release layer, is in the TD direction (lateral direction). ) And the thermal dimensional change rate in the MD direction (longitudinal direction at the time of film production, hereinafter also referred to as "longitudinal direction") are preferably not more than a specific value.
That is, the sum of the thermal dimensional change rate from 23 ° C. to 120 ° C. in the horizontal (TD) direction and the thermal dimensional change rate from 23 ° C. to 120 ° C. in the longitudinal (MD) direction of the laminated film is 6% or less. On the other hand, the laminated film is the sum of the thermal dimensional change rate from 23 ° C. to 120 ° C. in the TD direction (horizontal direction) and the thermal dimensional change rate from 23 ° C. to 120 ° C. in the longitudinal (MD) direction. Is preferably −5.0% or more.
The rate of change in thermal dimensions from 23 ° C. to 120 ° C. in the lateral (TD) direction and the longitudinal (MD) direction of the laminated film containing the release layer A (and, if desired, the release layer A') and the heat-resistant resin layer B. When the sum of the thermal dimensional change rates from 23 ° C. to 120 ° C. is 6% or less, the occurrence of wrinkles when mounted on the inner surface of the mold can be more effectively suppressed.

Further, the rate of change in thermal dimensions from 23 ° C. to 170 ° C. in the lateral (TD) direction and the longitudinal (MD) of the laminated film containing the release layer A (and the release layer A'if desired) and the heat-resistant resin layer B. The sum of the thermal dimensional change rates from 23 ° C. to 170 ° C. in the direction is preferably 7% or less, while the laminated film has thermal dimensions from 23 ° C. to 170 ° C. in the TD direction (horizontal direction). The sum of the rate of change and the rate of change in thermal dimensions from 23 ° C to 170 ° C in the longitudinal (MD) direction is preferably −5.0% or more.
The sum of the thermal dimensional change rate from 23 ° C. to 170 ° C. in the horizontal (TD) direction and the thermal dimensional change rate from 23 ° C. to 170 ° C. in the vertical (MD) direction of the laminated film is 7% or less. It is possible to more effectively suppress the occurrence of wrinkles when the mold is mounted on the inner surface of the mold.

In the second aspect of the present invention, the outgas permeability of the laminated film containing the release layer A (and the release layer A'if desired) and the heat-resistant resin layer B is 1.0% by weight or less. From the viewpoint of effectively preventing mold contamination, the outgas permeability is more preferably 0.7% by weight or less, and particularly preferably less than 0.5% by weight.
When the outgas permeability of the laminated film is 1.0% by weight or less, contamination of the mold in the semiconductor encapsulation process or the like can be effectively suppressed.
In the prior art, it is presumed that easily volatile components and the like from the epoxy resin and the like, which are sealing resins, permeate the film and cause contamination of the mold. The outgas component is a low molecular weight component that volatile from the sealing resin when heated, and it is presumed that a non-volatile substance at room temperature, such as silicone oil, contaminates the mold.
Since the laminate constituting the release film for the process of the second aspect in which the outgas permeability is equal to or less than a predetermined value, the contaminants in the outgas are also difficult to permeate, the contaminants from the sealing resin or the like are blocked and contaminated. It is presumed that the substance can be prevented from adhering to the mold.
Here, the sealing resin preferably used in the manufacturing process using the release film for the process of this embodiment is not particularly limited, and may be either a thermoplastic resin or a thermosetting resin, but in the art. Thermosetting resins are widely used. The material of the resin is not particularly limited, but an epoxy-based thermosetting resin or a silicone encapsulating resin can be preferably used, and an epoxy-based encapsulating resin is particularly preferable.
As the epoxy-based sealing resin preferably and particularly preferably used in the manufacturing process using the release film for the process of this embodiment, (A) epoxy resin, (B) phenol resin, (C) curing accelerator and (D) Epoxy resin compositions containing an inorganic filler can be mentioned.
The epoxy resin (A) used in the epoxy resin composition refers to all monomers, oligomers, and polymers having two or more epoxy groups in one molecule. For example, orthocresol novolac type epoxy resin, phenol novolac type epoxy resin, biphenyl type epoxy resin, bisphenol type epoxy resin, stillben type epoxy resin, triphenol methane type epoxy resin, phenol aralkyl type epoxy resin (phenylene skeleton, biphenyl skeleton, etc.) Included), naphthol type epoxy resin, alkyl modified triphenol methane type epoxy resin, triazine nucleus containing epoxy resin, dicyclopentadiene modified phenol type epoxy resin, etc., but are not limited thereto. Further, these may be used alone or in combination of two or more. Among these, a crystalline epoxy resin having a low melt viscosity, a high filling of an inorganic filler, a low moisture absorption of an epoxy resin composition, and an improvement in solder crack resistance. Is preferable.

The phenol resin (B) used in the epoxy resin composition refers to all monomers, oligomers, and polymers having two or more phenolic hydroxyl groups in one molecule. For example, phenol novolac resin, cresol novolac resin, phenol aralkyl resin (including phenylene skeleton, biphenyl skeleton, etc.), naphthol aralkyl resin (including phenylene skeleton, biphenyl skeleton, etc.), triphenolmethane resin, terpene-modified phenol resin, dicyclo Examples thereof include, but are not limited to, pentadiene-modified phenolic resins. Further, these may be used alone or in combination of two or more.

The curing accelerator (C) used in the epoxy resin composition refers to a compound that can be a catalyst for the cross-linking reaction between the epoxy resin (A) and the phenol resin (B), for example, 1,8-diazabicyclo (5,). 4,0) Diazabicycloalkenes such as undecene-7 and their derivatives, amine compounds such as tributylamine and benzyldimethylamine, organic phosphorus compounds such as triphenylphosphine and tetraphenylphosphonium / tetraphenylborate salts, 2-methyl Examples thereof include, but are not limited to, imidazole compounds such as imidazole. These may be used alone or in combination of two or more.

The type of the inorganic filler (D) used in the epoxy resin composition is not particularly limited, and those generally used as a sealing material can be used. Examples thereof include fused silica, crystalline silica, secondary aggregated silica, alumina, titanium white, aluminum hydroxide, talc, clay, glass fiber and the like, and these may be used alone or in combination of two or more. good. Fused silica is particularly preferable. The molten silica can be used in either a crushed form or a spherical shape, but it is more preferable to mainly use spherical silica in order to increase the blending amount and suppress an increase in the melt viscosity of the epoxy resin composition.

In addition to the components (A) to (D), the epoxy resin composition preferably and particularly preferably used in the production process using the release film for the process of this embodiment includes an inorganic ion exchanger and a coupling, if necessary. Agents, colorants typified by carbon black, natural waxes, synthetic waxes, higher fatty acids and their metal salts or mold release agents such as paraffins, brominated epoxy resins, antimony oxides, flame retardants such as phosphorus compounds, silicone oils, rubber Low stress components such as, and various additives such as antioxidants can be appropriately blended.

The outgas permeability of the laminated film is more preferably 0.7% by weight or less, and particularly preferably less than 0.5% by weight, from the viewpoint of effectively preventing mold contamination.
There is no particular lower limit to the outgas permeability of the laminated film, but it is usually 0.01% by weight or more as long as a realistic material is used from the viewpoint of economy and availability.

The outgas permeability of the laminated film can be measured by the following method.
(Measurement of outgas permeability [% by weight])
Put 10 mg of epoxy encapsulating resin in the vial 1, seal it with a cap and a rubber stopper, heat it at 120 ° C. for 30 minutes, perform GC-MS measurement by the static headspace method, and perform GC-MS measurement, and the amount of outgas in the vial 1. 1 is measured. (Analysis 1)
Subsequently, 10 mg of epoxy encapsulating resin is separately placed in the vial 1, and the vial 1 is prepared by covering the mouth of the vial with a film instead of a rubber stopper and sealing the bottle with a cap. Prepare a vial bottle 2 large enough to hold the bottle 1, store the vial bottle 1 in the vial bottle 2, seal it with a cap and a rubber stopper, heat it at 120 ° C. for 30 minutes, and perform GC-by the static headspace method. MS measurement is performed and the amount of outgas 2 in the vial 2 permeated with the film is evaluated. (Analysis 2)
For each film, the outgas permeability can be calculated from the outgas amount 1 obtained in the analysis 1 and the outgas amount 2 permeated through the film obtained in the analysis 2 according to the following (Equation 1).

Outgas permeability = Outgas amount 2 / Outgas amount 1 x 100 (% by weight) (Equation 1)

The outgas permeability of the laminated film shall be appropriately adjusted by adjusting the outgas permeability of any of the release layer A and the heat-resistant resin layer B constituting the laminated film, and the release layer A'if present. However, it is easy and practical to adjust by adjusting the outgas permeability of the heat-resistant resin layer B as described later.
Further, by providing a layer such as the gas barrier layer C, it is possible to effectively adjust the outgas permeability of the laminated film.

The oxygen permeability of the laminated film containing the release layer A (and, if desired, the release layer A') and the heat-resistant resin layer B, which constitute the release film for the process of the first aspect of the present invention, is 1000 ml / m. ^{It is 2} · day · MPa or less.
Here, the oxygen permeability is determined by using OX-TRAN2 / 21ML manufactured by Mocon Co., Ltd., in accordance with JIS K 7126, at a temperature of 20 ° C. and a humidity of 50% R.I. H. It is measured under the conditions of.
When the oxygen permeability of the laminated film is 1000 ml / m ² , day, MPa or less, contamination of the mold in the semiconductor encapsulation process or the like can be effectively suppressed.
The oxygen permeability has a certain positive correlation with the above-mentioned outgas permeability, and when the oxygen permeability is 1000 ml / m ² , day, MPa or less, the outgas permeability can also effectively suppress the contamination of the mold. There is a high possibility that such a low value, for example, a value as defined in the second aspect of the present invention. Therefore, as in the first aspect of the present invention, it is possible to measure more easily, and for a commercially available film, the oxygen permeability, which is often measured and known, is used as an index to obtain a predetermined outgas permeability. The process release film of the second aspect of the present invention or a member thereof having the above can be designed, manufactured, or obtained more efficiently.

The oxygen permeability of the laminated film ^{is more preferably 500 ml / m 2} · day · MPa or less, more preferably 250 ml / m ² · day · MPa or less, and 100 ml / m ² · day · MPa or less. It is more preferably 75 ml / m ² · day · MPa or less, and particularly preferably less than ^{50 ml / m 2 · day · MPa.}
There is no particular lower limit to the oxygen permeability of the laminated film, but it is usually 1 ml / m ² , day, MPa or more as long as a realistic material is used from the viewpoint of economy and availability.
The oxygen permeability of the laminated film can be measured using a gas barrier test apparatus according to, for example, JIS K 7126.
The oxygen permeability of the laminated film shall be appropriately adjusted by adjusting the oxygen permeability of any of the release layer A and the heat-resistant resin layer B constituting the laminated film, and the release layer A'if present. However, it is easy and practical to adjust by adjusting the oxygen permeability of the heat-resistant resin layer B as described later.
Further, the oxygen permeability of the laminated film can be effectively adjusted by providing a layer such as the gas barrier layer C.

Release layer A
The release layer A constituting the process release film of the present invention has a contact angle with water of 90 ° to 130 °, preferably 95 ° to 120 °, and more preferably 98 ° to 115 °. More preferably, it is 100 ° to 110 °. It is preferable to contain a resin selected from the group consisting of a fluororesin, a 4-methyl-1-pentene (co) polymer, and a polystyrene-based resin because of excellent mold releasability of the molded product and easy availability.

The fluororesin that can be used for the release layer A may be a resin containing a structural unit derived from tetrafluoroethylene. It may be a homopolymer of tetrafluoroethylene, or it may be a copolymer with another olefin. Examples of other olefins include ethylene. A copolymer containing tetrafluoroethylene and ethylene as a monomer constituent unit is a preferable example. In such a copolymer, the proportion of the constituent unit derived from tetrafluoroethylene is 55 to 100% by weight, and ethylene is used. The proportion of the structural unit derived from is preferably 0 to 45% by weight.

The 4-methyl-1-pentene (co) polymer that can be used for the release layer A may be a homopolymer of 4-methyl-1-pentene, or 4-methyl-1-pentene and It may be a copolymer with other olefins having 2 to 20 carbon atoms (hereinafter referred to as "olefins having 2 to 20 carbon atoms").

In the case of a copolymer of 4-methyl-1-pentene and an olefin having 2 to 20 carbon atoms, the olefin having 2 to 20 carbon atoms copolymerized with 4-methyl-1-pentene is 4-methyl. -1-It can impart flexibility to pentene. Examples of olefins having 2 to 20 carbon atoms include ethylene, propylene, 1-butene, 1-hexene, 1-heptene, 1-octene, 1-decene, 1-tetradecene, 1-hexadecene, 1-heptadecene, 1 -Includes octadecene, 1-eikosen, etc. These olefins may be used alone or in combination of two or more.

In the case of a copolymer of 4-methyl-1-pentene and an olefin having 2 to 20 carbon atoms, the proportion of structural units derived from 4-methyl-1-pentene is 96 to 99% by weight, and other than that. The proportion of the structural unit derived from the olefin having 2 to 20 carbon atoms is preferably 1 to 4% by weight. By reducing the content of the constituent units derived from olefins having 2 to 20 carbon atoms, the copolymer can be made hard, that is, the storage elastic modulus E'can be increased, and wrinkles can be suppressed in the sealing step or the like. It is advantageous to. On the other hand, by increasing the content of the structural unit derived from the olefin having 2 to 20 carbon atoms, the copolymer can be made soft, that is, the storage elastic modulus E'can be lowered, and the mold followability can be improved. It is advantageous to.

The 4-methyl-1-pentene (co) polymer can be produced by a method known to those skilled in the art. For example, it can be produced by a method using a known catalyst such as a Ziegler-Natta catalyst or a metallocene-based catalyst. The 4-methyl-1-pentene (co) polymer is preferably a highly crystalline (co) polymer. The crystalline copolymer may be either a copolymer having an isotactic structure or a copolymer having a syndiotactic structure, but it is particularly a copolymer having an isotactic structure. Is preferable from the viewpoint of physical properties, and is easily available. Furthermore, as long as the 4-methyl-1-pentene (co) polymer can be molded into a film and has strength to withstand the temperature and pressure during mold molding, its stereoregularity and molecular weight are particularly limited. Not done. The 4-methyl-1-pentene copolymer may be a commercially available copolymer such as TPX (registered trademark) manufactured by Mitsui Chemicals, Inc.

The polystyrene-based resin that can be used for the release layer A includes a homopolymer and a copolymer of styrene, and the structural unit derived from styrene contained in the polymer is at least 60% by weight or more. It is preferably, more preferably 80% by weight or more.
The polystyrene-based resin may be isotactic polystyrene or syndiotactic polystyrene, but isotropic polystyrene is preferable from the viewpoint of transparency, availability, etc., and has mold releasability, heat resistance, etc. From this point of view, syndiotactic polystyrene is preferable. One type of polystyrene may be used alone, or two or more types may be used in combination.

The release layer A preferably has heat resistance that can withstand the temperature of the mold at the time of molding (typically 120 to 180 ° C.). From this point of view, the release layer A preferably contains a crystalline resin having a crystalline component, and the melting point of the crystalline resin is preferably 190 ° C. or higher, more preferably 200 ° C. or higher and 300 ° C. or lower.
In order to bring crystallinity to the release layer A, for example, in a fluororesin, it is preferable to contain at least a structural unit derived from tetrafluoroethylene, and in a 4-methyl-1-pentene (co) polymer, 4-methyl-1. -It is preferable to contain at least a structural unit derived from penten, and it is preferable that the polystyrene-based resin contains at least syndiotactic polystyrene. Since the resin constituting the release layer A contains a crystal component, wrinkles are less likely to occur in the resin sealing step or the like, and it is suitable for suppressing the transfer of wrinkles to the molded product to cause poor appearance. ..

The resin containing the above crystalline component constituting the release layer A has a crystal melting heat amount of 15 J / g or more and 60 J / g or less in the first temperature raising step measured by differential scanning calorimetry (DSC) according to JIS K7221. It is preferably 20 J / g or more, and more preferably 50 J / g or less. When it is 15 J / g or more, in addition to being able to more effectively exhibit heat resistance and mold releasability that can withstand heat press molding in a resin sealing step or the like, the dimensional change rate is also suppressed. Therefore, it is possible to prevent the occurrence of wrinkles. On the other hand, when the amount of heat of crystal melting is 60 J / g or less, the release layer A has an appropriate hardness, so that sufficient followability to the mold of the film can be obtained in the resin sealing step or the like. There is no risk of film damage.

The release layer A may contain other resins in addition to the fluororesin, 4-methyl-1-pentene copolymer, and / or polystyrene-based resin. In this case, it is preferable that the hardness of the other resin is relatively high. Examples of other resins include polyamide-6, polyamide-66, polybutylene terephthalate, polyethylene terephthalate. As described above, even when the release layer A contains a large amount of a soft resin (for example, a 4-methyl-1-pentene copolymer containing a large amount of olefins having 2 to 20 carbon atoms), the hardness is relatively relatively high. By further containing a high resin, the release layer A can be hardened, which is advantageous in suppressing the occurrence of wrinkles in the sealing step and the like.

The content of these other resins is preferably, for example, 3 to 30% by weight with respect to the resin components constituting the release layer A. By setting the content of the other resin to 3% by weight or more, the effect of the addition can be made substantial, and by setting the content to 30% by weight or less, the releasability to the mold or the molded product is maintained. be able to.

In addition to the fluororesin, 4-methyl-1-pentene (co) polymer, and / or polystyrene-based resin, the release layer A is a heat-resistant stabilizer and a weather-resistant stabilizer as long as the object of the present invention is not impaired. , Anti-rusting agents, anti-copper damage stabilizers, anti-static agents, and other known additives generally blended in film resins may be included. The content of these additives can be, for example, 0.0001 to 10 parts by weight with respect to 100 parts by weight of the fluororesin, 4-methyl-1-pentene copolymer, and / or polystyrene-based resin.

The thickness of the release layer A is not particularly limited as long as the mold releasability with respect to the molded product is sufficient, but is usually 1 to 50 μm, preferably 5 to 30 μm.

The surface of the release layer A may have an uneven shape, if necessary, thereby improving the release property. The method of imparting unevenness to the surface of the release layer A is not particularly limited, but a general method such as embossing can be adopted.

Release layer A'
The process release film of the present invention may further have a release layer A'in addition to the release layer A and the heat-resistant resin layer B. That is, the process release film of the present invention may be a process release film which is a laminated film containing the release layer A, the heat-resistant resin layer B, and the release layer A'in this order.
The contact angle of the release layer A'which may form the process release film of the present invention with water is 90 ° to 130 °, preferably 95 ° to 120 °, and more preferably 98 ° to 98 °. It is 115 °, more preferably 100 ° to 110 °. The preferable material, structure, physical properties, etc. of the release layer A'are the same as those described above for the release layer A.

When the release film for the process is a laminated film containing the release layer A, the heat-resistant resin layer B, and the release layer A'in this order, the release layer A and the release layer A'are the same. It may be a layer of composition or a layer of different composition.
The release layer A and the release layer A'have the same or substantially the same configuration from the viewpoint of preventing warpage and ease of handling because all surfaces have the same releasability. Preferably, from the viewpoint of optimally designing each of the release layer A and the process using the release layer A', for example, the release layer A is made excellent in mold releasability from the mold, and the mold is released. From the viewpoint of making the layer A'excellent in peelability from the molded product, it is preferable that the release layer A and the release layer A'have different configurations.
When the release layer A and the release layer A'have different configurations, the release layer A and the release layer A'may be made of the same material but have different configurations such as thickness. However, the material and other configurations may be different.

Heat resistant resin layer B
The heat-resistant resin layer B constituting the process release film of the present invention has a function of supporting the release layer A (and, in some cases, the release layer A') and suppressing the generation of wrinkles due to the mold temperature or the like.
In the release film for process of the present invention, the heat-resistant resin layer B preferably has a gas barrier property, and the thermal dimensional change rate from 23 ° C. to 120 ° C. in the lateral (TD) direction of the heat-resistant resin layer B is 3. % Or less, or the rate of change in thermal dimensions from 23 ° C. to 170 ° C. in the lateral (TD) direction of the heat-resistant resin layer B is preferably 3% or less. Further, the heat-resistant resin layer B has a thermal dimensional change rate of 3% or less from 23 ° C. to 120 ° C. in the lateral (TD) direction and a thermal dimensional change from 23 ° C. to 170 ° C. in the lateral (TD) direction. More preferably, the rate is 3% or less.
By using a resin layer whose thermal dimensional change rate in the lateral (TD) direction shows the above-mentioned specific value as the heat-resistant resin layer B, the mechanism by which the generation of wrinkles in the release layer is suppressed more effectively is not necessarily clear. However, by using the heat-resistant resin layer B having a relatively small thermal expansion / contraction, the thermal expansion / contraction of the release layer A (or the release layer A') due to heating / cooling during the process is suppressed. It is presumed that it is related to.

Any resin layer including a non-stretched film can be used as the heat-resistant resin layer B, but it is particularly preferable that the heat-resistant resin layer B contains a stretched film.
The stretched film tends to have a low coefficient of thermal expansion or a negative coefficient of thermal expansion due to the influence of stretching in the manufacturing process, and the coefficient of thermal dimensional change from 23 ° C. to 120 ° C. in the lateral (TD) direction of the heat-resistant resin layer B is high. Since it is relatively easy to realize the characteristic that the thermal dimensional change rate from 23 ° C. to 170 ° C. in the lateral (TD) direction of the heat-resistant resin layer B is 3% or less, or 3% or less. It can be suitably used as the heat-resistant resin layer B.
The rate of change in thermal dimensions from 23 ° C. to 120 ° C. in the lateral (TD) direction of the heat-resistant resin layer B is preferably 2% or less, more preferably 1.5% or less, and 1% or less. It is more preferable, and on the other hand, it is preferably −10% or more.
The rate of change in thermal dimensions from 23 ° C. to 170 ° C. in the lateral (TD) direction of the heat-resistant resin layer B is preferably 2% or less, more preferably 1.5% or less, and 1% or less. It is more preferable, and on the other hand, it is preferably −10% or more.

The stretched film may be a uniaxially stretched film or a biaxially stretched film. In the case of a uniaxially stretched film, either longitudinal stretching or transverse stretching may be used, but it is desirable that the film is stretched at least in the lateral (TD) direction.
The method and apparatus for obtaining the stretched film are not particularly limited, and stretching may be performed by a method known in the art. For example, it can be stretched with a heating roll or a tenter type stretching machine.

As the stretched film, it is preferable to use a stretched film selected from the group consisting of a stretched polyester film, a stretched polyamide film, a stretched polypropylene film, and a stretched polyethylene film. These stretched films are relatively easy to reduce the coefficient of thermal expansion in the lateral (TD) direction or to be negative by stretching, and their mechanical properties are suitable for the use of the present invention. It is particularly suitable as a stretched film in the heat-resistant resin layer B because it is low in cost and relatively easy to obtain.

As the stretched polyester film, a stretched polyethylene terephthalate (PET) film and a stretched polybutylene terephthalate (PBT) film are preferable, and a biaxially stretched polyethylene terephthalate (PET) film is particularly preferable.
The polyamide constituting the stretched polyamide film is not particularly limited, but polyamide-6, polyamide-66 and the like can be preferably used.
As the stretched polypropylene film, a uniaxially stretched polypropylene film, a biaxially stretched polypropylene film and the like can be preferably used.
As the stretched polyethylene film, a uniaxially stretched polyethylene film, a biaxially stretched polyethylene film and the like can be preferably used.
The draw ratio is not particularly limited, and an appropriate value may be appropriately set in order to appropriately control the thermal dimensional change rate and realize suitable mechanical properties. For example, in the case of a stretched polypropylene film, the longitudinal direction is used. The range is preferably 2.7 to 8.0 times in both the horizontal direction, and in the case of a stretched polypropylene film, the range is preferably 2.7 to 5.0 times in both the vertical direction and the horizontal direction. In the case of a polypropylene film, in the case of a biaxially stretched polypropylene film, the range is preferably 5.0 to 10.0 times in both the vertical direction and the horizontal direction, and in the case of a uniaxially stretched polypropylene film, 1. The range is preferably 5 to 10.0 times.

The heat-resistant resin layer B has heat resistance that can withstand the temperature of the mold during molding (typically 120 to 180 ° C.) from the viewpoint of controlling the strength of the film and the rate of change in thermal dimensions within an appropriate range. Is preferable. From this point of view, the heat-resistant resin layer B preferably contains a crystalline resin having a crystalline component, and the melting point of the crystalline resin is preferably 120 ° C. or higher, and the melting point is 155 ° C. or higher and 300 ° C. or lower. Is more preferable, and it is more preferably 185 or more and 210 ° C. or lower, and particularly preferably 185 or more and 205 ° C. or lower.

As described above, the heat-resistant resin layer B preferably contains a crystalline resin having a crystalline component. As the crystalline resin contained in the heat-resistant resin layer B, for example, a crystalline resin such as a polyester resin, a polyamide resin, a polypropylene resin, or a polyethylene resin can be used for a part or all of the crystalline resin. Specifically, polyethylene terephthalate or polybutylene terephthalate for polyester resin, polyamide 6 or polyamide 66 for polyamide resin, isotactic polypropylene for polypropylene resin, high-density polyethylene or low-density polyethylene for polyethylene resin, and linear low It is preferable to use density polyethylene.

By including the crystal component of the crystalline resin in the heat-resistant resin layer B, wrinkles are less likely to occur in the resin sealing step or the like, and it is more advantageous to prevent wrinkles from being transferred to the molded product and causing poor appearance. Become.
The resin constituting the heat-resistant resin layer B preferably has a crystal melting heat amount of 20 J / g or more and 100 J / g or less in the first temperature raising step measured by differential scanning calorimetry (DSC) according to JIS K7221. It is more preferably 25 J / g or more and 65 J / g or less, more preferably 25 J / g or more and 55 J / g or less, and more preferably 28 J / g or more and 50 J / g or less, 28 J / g or less. It is more preferably g or more and 40 J / g or less, and further preferably 28 J / g or more and 35 J / g or less. When it is 20 J / g or more, heat resistance and mold releasability that can withstand hot press molding in a resin sealing step or the like can be effectively exhibited, and the dimensional change rate can be slightly suppressed. , The occurrence of wrinkles can also be prevented. On the other hand, when the amount of heat of crystal melting is 100 J / g or less, an appropriate hardness can be imparted to the heat-resistant resin layer B, so that sufficient followability of the film to the mold is ensured in the resin sealing step or the like. In addition to being able to do this, there is no risk of the film being easily damaged. In the present embodiment, the calorific value of crystal melting is the calorific value (J / g) on the vertical axis and the calorific value (J / g) on the horizontal axis obtained in the first heating step in the measurement by differential scanning calorimetry (DSC) according to JIS K7221. In a chart showing the relationship with temperature (° C.), it refers to a numerical value obtained by the sum of peak areas having peaks at 120 ° C. or higher.
The amount of heat of crystal melting of the heat-resistant resin layer B can be adjusted by appropriately setting heating and cooling conditions and stretching conditions during film production.

The thickness of the heat-resistant resin layer B is not particularly limited as long as the film strength can be secured, but is usually 1 to 1.
It is 00 μm, preferably 5 to 50 μm.

In order to impart the required gas barrier property to the release film of the present invention, the heat-resistant resin layer B (or the heat-resistant resin layer B and the layer adjacent thereto) preferably has a gas barrier property, and more specifically, outgas permeation. The degree is preferably 1.0% by weight or less. When the heat-resistant resin layer B (or the heat-resistant resin layer B and the layer adjacent thereto) has a gas barrier property, the gas barrier property of the release layer A (and the release layer A'if present) is low. Also, it is possible to impart the required gas barrier property to the release film of the present invention. In particular, when a 4-methyl-1-pentene (co) polymer is used for the release layer A and / or the release layer A', the gas barrier property of the 4-methyl-1-pentene (co) polymer is generally not high. Therefore, it is particularly preferable that the heat-resistant resin layer B (or the heat-resistant resin layer B and the layer adjacent thereto) have a high gas barrier property, and thus the excellent mold release brought about by the 4-methyl-1-pentene (co) polymer. It is possible to achieve both properties and the like, and excellent mold contamination resistance brought about by the heat-resistant resin layer B (or the heat-resistant resin layer B and a layer adjacent thereto).
The outgas permeability of the heat-resistant resin layer B (or the heat-resistant resin layer B and the layer adjacent thereto) is more preferably 0.7% by weight or less, and particularly preferably less than 0.5% by weight.
The method for measuring the oxygen permeability of the heat-resistant resin layer B (or the heat-resistant resin layer B and the layer adjacent thereto) is a method of measuring the oxygen permeability of a laminated film including a release layer A, a heat-resistant resin layer B, and optionally a release layer A'. The method for measuring oxygen permeation is the same as that described above.

The means for imparting preferable gas barrier properties to the heat-resistant resin layer B is not particularly limited, but for example, the type of resin constituting the heat-resistant resin layer B or the type and amount of additives added thereto are appropriately selected. The gas barrier property may be improved, or the gas barrier property may be improved by stretching the polymer film constituting the heat-resistant resin layer B. As a matter of course, the gas barrier property can be further improved by increasing the thickness of the heat-resistant resin layer B.

Gas barrier layer C
Alternatively, by laminating the gas barrier layer C on the heat-resistant resin layer B, the gas barrier property of the heat-resistant resin layer B and the gas barrier layer C adjacent thereto may be improved as a whole.
The gas barrier layer C may be an inorganic layer or an organic layer. An inorganic layer is preferable from the viewpoint of cost, transparency, heat resistance, etc., an organic layer is preferable from the viewpoint of adhesion to a base material and resistance to cracking, and further, an inorganic layer and an organic layer are preferable. By stacking the layers, it is possible to form a configuration that makes the best use of the features of both.

The inorganic substance that forms a suitable inorganic layer is not particularly limited as long as it does not react with other layers by heating during mold molding, does not decompose, and can maintain the layer, but mold molding even when heated to 165 ° C. A substance that does not react with other layers due to heating at times, does not decompose, and can maintain the layer is preferable, and more preferably, even if heated to 185 ° C., it does not react with other layers due to heating such as during mold molding. It is desirable that the material does not decompose and can maintain the layer.

The inorganic layer is preferably a thin film obtained by amorphizing a metal or an oxide of the metal. For example, silicon (Si), aluminum (Al), magnesium (Mg), calcium (Ca), potassium (K), tin (Sn), sodium (Na), boron (B), titanium (Ti), lead (Pb). ), Zirconium (Zr), yttrium (Y) and other metals, or a thin film obtained by amorphizing the oxide of the metal. Among the above, aluminum, silicon, their oxides, and combinations thereof are preferable from the viewpoint of gas barrier property and ease of forming an inorganic layer, and are preferable in terms of releasability, gas permeability, ease of production, and ductility. From the viewpoint of property (easiness of elongation), aluminum and its oxide are more preferable.

Further, the inorganic layer is preferably formed on the entire one surface of the heat-resistant resin layer B, and it is preferable that the inorganic layer is formed as a continuous film at least in the portion in contact with the mold.
Examples of the method for forming the inorganic layer include a physical vapor deposition method (PVD method) such as a vacuum vapor deposition method, a sputtering method, and an ion plating method, or a plasma chemical vapor deposition method and a thermochemical vapor deposition method. Examples thereof include a chemical vapor deposition method (CVD method, CVD method) such as a phase growth method and a photochemical vapor deposition method.

In the present embodiment, the method for forming the inorganic layer will be specifically described. Alternatively, an oxidation reaction vapor deposition method in which a metal or metal oxide is used as a raw material and oxygen gas or the like is introduced to oxidize and deposit on the heat-resistant resin layer B, and a plasma-assisted oxidation reaction in which the oxidation reaction is assisted by plasma. An inorganic layer can be formed by using a vapor deposition method or the like. Further, in the present invention, when forming a vapor-deposited film of silicon oxide, an inorganic layer can be formed by using a plasma chemical vapor deposition method using organosiloxane as a raw material.

The thickness of the inorganic layer varies depending on the material used and the like, but is usually 5 to 200 nm. When it is 5 nm or more, the outgas permeability becomes low, and mold contamination and blockage of the vacuum line for film adsorption can be effectively suppressed. Further, when it is 200 nm or less, it is easy to prevent deterioration of the mold followability.
The thickness of the inorganic layer is preferably 5 to 200 nm, more preferably 8 to 180 nm, and even more preferably 10 to 150 nm.
Even when an aluminum layer is used as the inorganic layer, it is preferably 5 to 200 nm, more preferably 8 to 180 nm, and even more preferably 10 to 150 nm.

The organic substances that form a suitable organic layer are also not particularly limited, but for example, a polymer having a vinyl alcohol unit (hereinafter, also referred to as “polymer (a)”) and a polymer having a vinylidene chloride unit (hereinafter, referred to as “polymer”). At least one polymer selected from the group consisting of "polymer (a)") can be particularly preferably used.
The "vinyl alcohol unit" is a unit in which the acetoxy group of the vinyl acetate unit is converted into a hydroxyl group by chemically converting the polymer obtained by the polymerization of vinyl acetate.
The polymer may or may not have a crosslinked structure.

The polymer (a) may be composed of only vinyl alcohol units, or may have units other than vinyl alcohol units.
The ratio of vinyl alcohol units in the polymer (a) is not particularly limited, but is preferably 60 mol% or more, more preferably 70 mol% or more, and particularly preferably 80 mol% or more, based on the total of all units. When the ratio of the vinyl alcohol unit is equal to or higher than the above lower limit value, the gas barrier property is more excellent.

Examples of the polymer (A) include the following polymers (A1) and polymers (A2).
Polymer (A1): A polymer having a vinyl alcohol unit and not having a crosslinked structure.
Polymer (A2): A polymer having a vinyl alcohol unit and having a crosslinked structure.

The polymer (A1) may be composed of only vinyl alcohol units, or may have units other than vinyl alcohol units.
As the polymer (A1), for example, a copolymer having a polyvinyl alcohol (hereinafter, also referred to as “PVA”) or vinyl alcohol unit and a unit other than the vinyl alcohol unit and the vinyl acetate unit (hereinafter, “coweight”). It is also referred to as "coalescence (A11)"). The copolymer (A11) may further have vinyl acetate units. Any one of these polymers may be used alone, or two or more of these polymers may be used in combination.

PVA is a polymer composed of only vinyl alcohol units, or a polymer composed of vinyl alcohol units and vinyl acetate units.
As PVA, complete saponification of polyvinyl acetate (saponification degree 99 mol% or more and 100 mol% or less), semi-complete saponification (saponification degree 90 mol% or more and less than 99 mol%), partial saponification (saponification degree 70 mol%) More than 90 mol%) and the like.
The saponification degree of PVA is preferably 80 to 100 mol%, more preferably 85 to 100 mol%, and particularly preferably 90 to 100 mol%. The higher the saponification degree, the higher the gas barrier property of the gas barrier layer C tends to be.
The degree of saponification is the rate at which the acetoxy group contained in polyvinyl acetate, which is the raw material of PVA, is changed to a hydroxyl group by saponification in a unit ratio (mol%), and is defined by the following formula. The degree of saponification can be determined by the method specified in JIS K6726: 1994.
Degree of saponification (mol%) = {(number of hydroxyl groups) / (number of hydroxyl groups + number of acetoxy groups)} x 100

Examples of the other unit in the copolymer (A11) include a unit having a dihydroxyalkyl group, an acetoacetyl group, an oxyalkylene group, a carboxy group, an alkoxycarbonyl group and the like, a unit derived from an olefin such as ethylene, and the like. The other unit of the copolymer (A11) may be one kind or two or more kinds.

The polymer (a) may be composed of only vinylidene chloride units, or may further have units other than vinylidene chloride units.

The ratio of vinylidene chloride units in the polymer (a) is preferably 70 mol% or more, and particularly preferably 80 mol% or more, based on the total of all units. When the ratio of vinylidene chloride unit is equal to or higher than the above lower limit value, the gas barrier property of the gas barrier layer C is more excellent.

Examples of the polymer (a) include the following polymers (a 1) and polymers (a 2).
Polymer (a1): A polymer having a vinylidene chloride unit and not having a crosslinked structure.
Polymer (a2): A polymer having a vinylidene chloride unit and a crosslinked structure.

Examples of the polymer (a1) include polyvinylidene chloride, vinylidene chloride-alkyl acrylate copolymer, and the like.
Examples of the polymer (a2) include a polymer obtained by reacting the polymer (a1) with a cross-linking agent.
As the cross-linking agent, a water-soluble cross-linking agent that reacts with a halogen group or a functional group bonded to an alkyl acrylate to form a cross-linked structure is preferable. Specific examples include an organometallic compound, an isocyanate compound having two or more isocyanate groups, and a bisvinyl sulfone compound. Specific examples of these cross-linking agents include the same as described above.

Further, as the organic layer, a layer formed by heating and curing a mixed solution of a polycarboxylic acid such as polyacrylic acid or polymethacrylic acid and a polyamine compound such as polyethyleneimine or polyallylimine may be used. At this time, from the viewpoint of preventing gelation of the mixed solution, it is preferable to set the neutralization degree to 50 to 100 equivalent%.
The ratio of the polycarboxylic acid polyacrylic acid to the polyamine compound is (the number of moles of -COO- groups contained in the polycarboxylic acid in the gas barrier coating material) / (amino groups contained in the polyamine compound in the gas barrier coating material). The number of moles) is preferably more than 100/22, more preferably 100/25 or more, and particularly preferably 100/29 or more. On the other hand, (the number of moles of -COO- groups contained in the polycarboxylic acid in the gas barrier coating material) / (the number of moles of amino groups contained in the polyamine compound in the gas barrier coating material) is preferably 100/99 or less. , More preferably 100/86 or less, and particularly preferably 100/75 or less.
The molecular weight of the polycarboxylic acid is usually 5000 to 1500,000, preferably 1000 to 1,000,000.
On the other hand, the average molecular weight of the polyamine compound is usually 1500 to 1,000,000, preferably 1500 to 5,000,000, more preferably 1500 to 250,000, and particularly preferably 1500 to 100000.

In the process release film of the present invention, when the gas barrier layer C is made of a metal or a metal oxide, a protective resin layer D is formed on the gas barrier layer C to protect it from external impacts and the like. This is also a preferred embodiment.

The material of the protective resin layer D is not particularly limited as long as it can be formed on the gas barrier layer C formed on the heat-resistant resin layer B by coating means such as coating, printing, and depping. For example, resins such as urethane resin, melamine resin, acrylic resin, polyvinylidene chloride, ethylene-vinyl alcohol resin and polyvinyl alcohol resin, acrylic acid metal salt resin, and polyamide crosslinked resin are preferable. Of these, urethane resin, metal acrylate resin, and cross-linked polyamide resin are more preferable, and metal acrylate resin and cross-linked polyamide resin are most preferable.

Other Layers The process release film of the present invention has layers other than the release layer A, the heat-resistant resin layer B, the release layer A', and the gas barrier layer C, unless contrary to the object of the present invention. You may be. For example, the above-mentioned protective resin layer D may be provided on the gas barrier layer C, or an adhesive layer may be provided between the release layer A (or the release layer A') and the heat-resistant resin layer B, if necessary. May have. The material used for the adhesive layer is not particularly limited as long as it can firmly bond the release layer A and the heat-resistant resin layer B and does not peel off even in the resin sealing step or the mold release step.

For example, when the release layer A (or the release layer A') contains a 4-methyl-1-pentene copolymer, the adhesive layer is a modified 4-methyl-1 graft-modified with an unsaturated carboxylic acid or the like. A −pentene-based copolymer resin, an olefin-based adhesive resin composed of a 4-methyl-1-pentene-based copolymer and an α-olefin-based copolymer, or the like is preferable. When the release layer A (or the release layer A') contains a fluororesin, the adhesive layer is preferably a polyester-based, acrylic-based, or fluororubber-based pressure-sensitive adhesive. The thickness of the adhesive layer is not particularly limited as long as the adhesiveness between the release layer A (or the release layer A') and the heat-resistant resin layer B can be improved, but is, for example, 0.5 to 10 μm.

The total thickness of the release film for a process of the present invention is not particularly limited, but is preferably 10 to 300 μm, more preferably 30 to 150 μm, for example. When the total thickness of the release film is within the above range, it is preferable because the handleability when used as a roll is good and the amount of waste of the film is small.

Hereinafter, preferred embodiments of the process release film of the present invention will be described in more detail. FIG. 1 is a schematic view showing an example of a release film for a process having a three-layer structure. As shown in FIG. 1, the release film 10 has a heat-resistant resin layer 12 and a release layer 16 formed on one side thereof via an adhesive layer 14.

The release layer 16 is the above-mentioned release layer A, the heat-resistant resin layer 12 is the above-mentioned heat-resistant resin layer B, and the adhesive layer 14 is the above-mentioned adhesive layer. The release layer 16 is preferably arranged on the side in contact with the sealing resin in the sealing process; the heat resistant resin layer 12 is preferably arranged on the side in contact with the inner surface of the mold in the sealing process.
Further, as shown in FIG. 3, a gas barrier layer 17 may be provided adjacent to the heat-resistant resin layer 12.

FIG. 2 is a schematic view showing an example of a release film for a process having a five-layer structure. Members having the same functions as those in FIG. 1 are designated by the same reference numerals. As shown in FIG. 2, the release film 20 has a heat-resistant resin layer 12, and a release layer 16A and a release layer 16B formed on both sides thereof via an adhesive layer 14. The release layer 16A is the above-mentioned release layer A, the heat-resistant resin layer 12 is the above-mentioned heat-resistant resin layer B, the release layer 16B is the above-mentioned release layer A', and the adhesive layer 14 is the above-mentioned above-mentioned, respectively. It is an adhesive layer.

The compositions of the release layers 16A and 16B may be the same or different from each other. The thicknesses of the release layers 16A and 16B may also be the same or different from each other. However, when the release layers 16A and 16B have the same composition and thickness, they have a symmetrical structure and the release film itself is less likely to warp, which is preferable. In particular, the release film of the present invention may be stressed by heating in the sealing process, so it is preferable to suppress warpage. As described above, when the mold release layers 16A and 16B are formed on both surfaces of the heat-resistant resin layer 12, it is preferable that good mold releasability can be obtained on both the molded product and the inner surface of the mold.
Further, as shown in FIG. 4, a gas barrier layer 17 may be provided adjacent to the heat-resistant resin layer 12.

The sealing resin preferably used in the manufacturing process using the release film for the process of the present invention is not particularly limited and may be either a thermoplastic resin or a thermosetting resin, but in the art, heat is used. Curable resins are widely used. The material of the resin is not particularly limited, but an epoxy-based thermosetting resin or a silicone encapsulating resin can be preferably used, and an epoxy-based encapsulating resin is particularly preferable.
As the epoxy-based sealing resin preferably and particularly preferably used in the manufacturing process using the release film for the process of the present invention, (A) epoxy resin, (B) phenol resin, (C) curing accelerator and (D) Epoxy resin compositions containing an inorganic filler can be mentioned.
The epoxy resin (A) used in the epoxy resin composition refers to all monomers, oligomers, and polymers having two or more epoxy groups in one molecule. For example, orthocresol novolac type epoxy resin, phenol novolac type epoxy resin, biphenyl type epoxy resin, bisphenol type epoxy resin, stillben type epoxy resin, triphenol methane type epoxy resin, phenol aralkyl type epoxy resin (phenylene skeleton, biphenyl skeleton, etc.) Included), naphthol type epoxy resin, alkyl modified triphenol methane type epoxy resin, triazine nucleus containing epoxy resin, dicyclopentadiene modified phenol type epoxy resin, etc., but are not limited thereto. Further, these may be used alone or in combination of two or more. Among these, a crystalline epoxy resin having a low melt viscosity, a high filling of an inorganic filler, a low moisture absorption of an epoxy resin composition, and an improvement in solder crack resistance. Is preferable.

The phenol resin (B) used in the epoxy resin composition refers to all monomers, oligomers, and polymers having two or more phenolic hydroxyl groups in one molecule. For example, phenol novolac resin, cresol novolac resin, phenol aralkyl resin (including phenylene skeleton, biphenyl skeleton, etc.), naphthol aralkyl resin (including phenylene skeleton, biphenyl skeleton, etc.), triphenolmethane resin, terpene-modified phenol resin, dicyclo Examples thereof include, but are not limited to, pentadiene-modified phenolic resins. Further, these may be used alone or in combination of two or more.

The curing accelerator (C) used in the epoxy resin composition refers to a compound that can be a catalyst for the cross-linking reaction between the epoxy resin (A) and the phenol resin (B), for example, 1,8-diazabicyclo (5,). 4,0) Diazabicycloalkenes such as undecene-7 and their derivatives, amine compounds such as tributylamine and benzyldimethylamine, organic phosphorus compounds such as triphenylphosphine and tetraphenylphosphonium / tetraphenylborate salts, 2-methyl Examples thereof include, but are not limited to, imidazole compounds such as imidazole. These may be used alone or in combination of two or more.

The type of the inorganic filler (D) used in the epoxy resin composition is not particularly limited, and those generally used as a sealing material can be used. Examples thereof include fused silica, crystalline silica, secondary aggregated silica, alumina, titanium white, aluminum hydroxide, talc, clay, glass fiber and the like, and these may be used alone or in combination of two or more. good. Fused silica is particularly preferable. The molten silica can be used in either a crushed form or a spherical shape, but it is more preferable to mainly use spherical silica in order to increase the blending amount and suppress an increase in the melt viscosity of the epoxy resin composition.

The epoxy resin composition preferably and particularly preferably used in the production process using the release film for the process of the present invention includes the components (A) to (D), as well as an inorganic ion exchanger and a coupling, if necessary. Agents, colorants typified by carbon black, natural waxes, synthetic waxes, higher fatty acids and their metal salts or mold release agents such as paraffin, brominated epoxy resins, antimony oxide, flame retardant agents such as phosphorus compounds, silicone oil, rubber Low stress components such as, and various additives such as antioxidants can be appropriately blended.

Method for Producing Process Release Film The process release film of the present invention can be produced by any method. For example, 1) a method of producing a release film for a process by co-extruding and laminating a release layer A and a heat-resistant resin layer B (co-extrusion forming method), and 2) on a film to be a heat-resistant resin layer B. A molten resin of the resin to be the release layer A or the adhesive layer is applied and dried, or a resin solution in which the resin to be the release layer A or the adhesive layer is dissolved in a solvent is applied and dried. A method for producing a release film for a process (coating method), 3) A film to be a release layer A and a film to be a heat-resistant resin layer B are produced in advance, and these films are laminated. There is a method (lamination method) for producing a release film for a process.

In the method 3), as a method of laminating each resin film, various known laminating methods can be adopted, and examples thereof include an extrusion laminating method, a dry laminating method, and a thermal laminating method.
In the dry laminating method, each resin film is laminated using an adhesive. As the adhesive, a known adhesive for dry laminating can be used. For example, a polyvinyl acetate adhesive; a homopolymer or copolymer of an acrylic acid ester (ethyl acrylate, butyl acrylate, 2-ethylhexyl ester of acrylic acid, etc.), or an acrylic acid ester and another monomer (methacrylic acid). Polyacrylic acid ester-based adhesive composed of a copolymer with methyl, acrylonitrile, styrene, etc.; cyanoacrylate-based adhesive; ethylene and other monomers (vinyl acetate, ethyl acrylate, acrylic acid, methacrylic acid) Etc.) Ethylene copolymer adhesive; cellulosic adhesive; polyester adhesive; polyamide adhesive; polyimide adhesive; amino resin adhesive made of urea resin or melamine resin, etc. Adhesives; Phenole resin-based adhesives; Epoxy-based adhesives; Polyurethane-based adhesives that crosslink polyols (polyether polyols, polyester polyols, etc.) with isocyanates and / or isocyanurates; Reactive (meth) acrylic adhesives Rubber-based adhesives made of chloroprene rubber, nitrile rubber, styrene-butadiene rubber, etc .; Silicone-based adhesives; Inorganic adhesives made of alkali metal silicate, low-melting point glass, etc .; Other adhesives can be used. As the resin film to be laminated by the method of 3), a commercially available one may be used, or one manufactured by a known manufacturing method may be used. The resin film may be subjected to surface treatment such as corona treatment, atmospheric pressure plasma treatment, vacuum plasma treatment, and primer coating treatment. The method for producing the resin film is not particularly limited, and a known production method can be used.

1) The coextrusion molding method is preferable in that defects due to foreign matter getting caught between the resin layer to be the release layer A and the resin layer to be the heat-resistant resin layer B and the release film are less likely to warp. .. 3) The laminating method is a suitable manufacturing method when a stretched film is used for the heat-resistant resin layer B. In this case, it is preferable to form an appropriate adhesive layer at the interface between the films, if necessary. In order to improve the adhesiveness between the films, the interface between the films may be subjected to a surface treatment such as a corona discharge treatment, if necessary.

The release film for process may be uniaxially or biaxially stretched as required, thereby increasing the film strength of the film.

The coating means in the above 2) coating method is not particularly limited, but various coaters such as a roll coater, a die coater, and a spray coater are used. The melt extrusion means is not particularly limited, and for example, an extruder having a T-type die or an inflation-type die is used.

Manufacturing Process The process release film of the present invention can be used by arranging it between the semiconductor chip or the like and the inner surface of the mold when the semiconductor chip or the like is placed in the mold and the resin is injected and molded. .. By using the process release film of the present invention, it is possible to effectively prevent mold release defects, burrs, etc. from the mold.
The resin used in the above manufacturing process may be either a thermoplastic resin or a thermosetting resin, but a thermosetting resin is widely used in the technical field, and an epoxy-based thermosetting resin is particularly used. It is preferable to use it.
The most typical manufacturing process is the encapsulation of a semiconductor chip, but the present invention is not limited to this, and the present invention can be applied to a fiber reinforced plastic molding process, a plastic lens molding process, and the like. ..

5, 6A and 6B are schematic views showing an example of a method for manufacturing a resin-sealed semiconductor using the release film of the present invention.
As shown in FIG. 5a, the release film 1 of the present invention is supplied into the molding die 2 from a roll-shaped roll by rolls 1-2 and 1-3. Next, the release film 1 is placed on the inner surface of the upper mold 2. If necessary, the inner surface of the upper mold 2 may be evacuated so that the release film 1 is brought into close contact with the inner surface of the upper mold 2. The semiconductor chip 6 arranged on the substrate is arranged in the lower mold 5 of the molding molding apparatus, and the sealing resin is arranged on the semiconductor chip 6 or the liquid sealing resin is covered with the semiconductor chip 6. The sealing resin 4 is accommodated between the upper mold 2 and the lower mold 5 on which the release film 1 which has been exhaust-sucked and adhered to the mold 1 is arranged. Next, as shown in FIG. 5b, the upper mold 2 and the lower mold 5 are closed with the release film 1 of the present invention, and the sealing resin 4 is cured.

As shown in FIG. 5c, the sealing resin 4 is fluidized in the mold by the mold closing and curing, and the sealing resin 4 flows into the space and is filled and sealed so as to surround the side surface of the semiconductor chip 6. The upper mold 2 and the lower mold 5 open the mold 6 and take out the chip 6. After opening the mold and taking out the molded product, the release film 1 is repeatedly used a plurality of times, or a new release film is supplied and subjected to the next resin molding molding.

The release film of the present invention is brought into close contact with the upper mold, interposed between the mold and the sealing resin, and resin molded to prevent the resin from adhering to the mold and stain the resin mold surface of the mold. And the molded product can be easily released from the mold.
The release film can be newly supplied and resin-molded for each resin molding operation, or can be newly supplied and resin-molded for each of a plurality of resin molding operations.

The sealing resin may be a liquid resin or a resin that is solid at room temperature, but a sealing material such as one that becomes liquid at the time of resin sealing can be appropriately adopted. Specifically, epoxy-based (biphenyl-type epoxy resin, bisphenol epoxy resin, o-cresol novolac-type epoxy resin, etc.) is mainly used as the sealing resin material, and polyimide-based resin (biphenyl-type epoxy resin, o-cresol novolac-type epoxy resin, etc.) is used as the sealing resin other than the epoxy resin. Bismaleimide-based), silicone-based resin (heat-curable addition type) and other commonly used sealing resins can be used. The resin sealing conditions vary depending on the sealing resin used, but may be appropriately set in the range of, for example, a curing temperature of 120 ° C. to 180 ° C., a molding pressure of 10 to 50 kg / cm ² , and a curing time of 1 to 60 minutes. can.

The steps before and after the step of arranging the release film 1 on the inner surface of the molding die 8 and the step of arranging the semiconductor chip 6 in the molding die 8 are not particularly limited and may be performed at the same time, or the semiconductor chip 6 may be placed. After arranging, the release film 1 may be arranged, or after arranging the release film 1, the semiconductor chip 6 may be arranged.

As described above, since the release film 1 has the release layer A (and, if desired, the release layer A') having high releasability, the semiconductor package 4-2 can be easily released. Further, since the release film 1 has an appropriate flexibility, it is excellent in followability to the mold shape, but is less likely to be wrinkled by the heat of the molding mold 8. Therefore, the sealed semiconductor package has a good appearance without wrinkles being transferred to the resin sealing surface of the sealed semiconductor package 4-2 or a portion not filled with the resin (resin chipping). 4-2 can be obtained.

Further, not limited to the compression molding method in which the solid sealing resin material 4 is pressurized and heated as shown in FIG. 5, a transfer molding method in which the sealing resin material in a fluid state is injected as described later is adopted. May be good.

6A and 6B are schematic views showing a transfer molding method which is an example of a method for manufacturing a resin-sealed semiconductor using the release film of the present invention.

As shown in FIG. 6A, the release film 22 of the present invention is supplied from the roll-shaped roll into the molding die 28 by the roll 24 and the roll 26 (step a). Next, the release film 22 is placed on the inner surface 30A of the upper mold 30 (step b). If necessary, the upper mold inner surface 30A may be evacuated to bring the release film 22 into close contact with the upper mold inner surface 30A. Next, the semiconductor chip 34 to be resin-sealed (semiconductor chip 34 fixed to the substrate 34A) is placed in the molding die 28, the sealing resin material 36 is set (step c), and the mold is fastened (step c). Step d).

Then, as shown in FIG. 6B, the sealing resin material 36 is injected into the molding die 28 under predetermined heating and pressurizing conditions (step e). The temperature (molding temperature) of the molding die 28 at this time is, for example, 165 to 185 ° C., the molding pressure is, for example, 7 to 12 MPa, and the molding time is, for example, about 90 seconds. Then, after holding for a certain period of time, the upper mold 30 and the lower mold 32 are opened, and the resin-sealed semiconductor package 40 and the release film 22 are simultaneously or sequentially released (step f).

Then, as shown in FIG. 7, a desired semiconductor package 44 can be obtained by removing the excess resin portion 42 from the obtained semiconductor package 40. The release film 22 may be used as it is for resin encapsulation of other semiconductor chips, but each time molding is completed, the roll is operated to feed the film, and the release film 22 is newly formed into a molding die. It is preferable to supply to 28.

The steps before and after the step of arranging the release film 22 on the inner surface of the molding die 28 and the step of arranging the semiconductor chip 34 in the molding die 28 are not particularly limited and may be performed at the same time, or the semiconductor chip 34 may be placed. After arranging, the release film 22 may be arranged, or after arranging the release film 22, the semiconductor chip 34 may be arranged.

As described above, since the release film 22 has the release layer A (and, if desired, the release layer A') having high releasability, the semiconductor package 40 can be easily released. Further, since the release film 22 has appropriate flexibility, it is excellent in followability to the mold shape, but is less likely to be wrinkled by the heat of the molding mold 28. Therefore, the semiconductor package 40 having a good appearance can be obtained without wrinkles being transferred to the resin sealing surface of the semiconductor package 40 or a portion (resin chipping) not filled with the resin.

The release film of the present invention is not limited to the process of sealing a semiconductor element with a resin, but is also a process of molding and releasing various molded products using a molding mold, for example, a fiber-reinforced plastic molding and a mold release process, and a plastic lens molding. It can also be preferably used in a mold removal process and the like.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited thereto.

In the following Examples / Comparative Examples, the physical properties / characteristics were evaluated by the following method.
(Thermal dimensional change rate)
A film sample was cut into a length of 20 mm and a width of 4 mm in the longitudinal direction and the width direction of the film, respectively, and using TMA (thermomechanical analyzer, product name: Q400) manufactured by TA Instruments, the distance between chucks was 8 mm and 0.005 N. After holding at 23 ° C for 5 minutes with a load applied, the temperature is raised from 23 ° C to 120 ° C at a heating rate of 10 ° C / min, the dimensional change in each direction is measured, and the dimensional change is performed by the following formula (1). The rate was calculated.

Thermal dimensional change rate (%) (23 → 120 ° C) = {[(L _2- L ₁ ) / L ₁ ] × 100}
... (1)
L ₁ : Sample length (mm) at 23 ° C.
L ₂ : Sample length (mm) at 120 ° C.

Contact angle with water (water contact angle)
In accordance with JIS R3257, the water contact angle on the surfaces of the release layers A and A'was measured using a contact angle measuring device (FACECA-W, manufactured by Kyowa Interface Science).

(Melting point (Tm), heat of crystal fusion)
Using Q100 manufactured by TA Instruments as a differential scanning calorimeter (DSC), weighed approximately 5 mg of the polymer sample, and in accordance with JIS K7121, 25 under the condition of nitrogen gas inflow: 50 ml / min. The heat-melting curve was measured by raising the temperature from ° C. to 280 ° C. at a heating rate of 10 ° C./min, and the melting point (Tm) of the sample and the amount of heat of crystal melting were determined from the obtained heat-melting curve.

(Removability)
As shown in FIG. 5, the process release films produced in each Example / Comparative Example are placed between the upper mold and the lower mold in a state where a tension of 10 N is applied, and then the upper mold is parted. It was vacuum-adsorbed on the surface. Next, a sealing resin (trade name: R4212-2C, manufactured by Nagase & Co., Ltd.) was filled on the substrate so as to cover the semiconductor chip, and then the semiconductor chip fixed to the substrate was placed in the lower mold and molded. At this time, the temperature of the molding die (molding temperature) was 120 ° C., the molding pressure was 10 MPa, and the molding time was 400 seconds. Then, as shown in FIG. 5c, the semiconductor chip was sealed with a sealing resin, and then the resin-sealed semiconductor chip (semiconductor package) was released from the release film.
The releasability of the releasable film was evaluated according to the following criteria.
◯: The release film naturally peels off at the same time as the mold is opened.
Δ: The release film does not peel off naturally, but it easily peels off when pulled by hand (when tension is applied).
X: The release film is in close contact with the resin sealing surface of the semiconductor package and cannot be peeled off by hand.

(Wrinkle resistance)
The state of wrinkles on the release film and the resin-sealed surface of the semiconductor package after the release in the above step was evaluated according to the following criteria.
◯: There are no wrinkles on either the release film or the semiconductor package.
Δ: There are slight wrinkles on the release film, but there is no wrinkle transfer to the semiconductor package.
×: There are many wrinkles on the semiconductor package as well as the release film.

(Mold followability)
The mold followability of the release film when the mold was released in the above step was evaluated according to the following criteria.
◯: There is no resin chipping (the part where the resin is not filled) in the semiconductor package.
Δ: There is a slight resin chipping at the edge of the semiconductor package (however, chipping due to wrinkles is excluded) ×: There is a lot of resin chipping at the edge of the semiconductor package (however, chipping due to wrinkles is excluded)

(Mold contamination)
As shown in FIG. 8, a 0.3 mm-thick Al plate, a square-shaped 0.5 mm-thick SUS frame (inner frame 100 mm square), and a release film for a process produced in each Example / Comparative Example. Two sheets and an Al plate having a thickness of 0.3 mm were arranged in this order. Furthermore, a sealing resin for semiconductors (trade name: R4212-2C, manufactured by Nagase Sangyo Co., Ltd.) is placed between two release films using a 0.1 mm thick SUS frame cut into a square shape as a spacer. Was injected and hot-pressed with a flat plate press in an environment of 120 ° C., 10 MPa, and 400 seconds. After pressing, the 0.3 mm thick Al plate was repeatedly used, and other than that, press molding was repeated 1000 times under the above conditions, and the stains adhering to the Al plate surface were evaluated as mold stains according to the following criteria. The arrangement at the time of evaluation is shown in FIG.
◯: No dirt on the Al surface ×: Dirt on the Al surface was seen

(Measurement of outgas permeability [% by weight])
As shown in FIG. 9A, 10 mg of the sealing resin for semiconductors (trade name: R4212-2C, manufactured by Nagase Sangyo Co., Ltd.) is placed in a vial 1, sealed with a cap and a rubber stopper, and then sealed at 120 ° C. The amount of outgas in the vial 1 was measured by heating for 30 minutes and performing GC-MS measurement by the static headspace method. (Analysis 1)
<Analysis conditions>
Pretreatment device: Headspace sampler (manufactured by Agilent Technologies)
Measuring device: GC-MS (manufactured by Agilent Technologies)
Injection method: Split method (10: 1)
Column: DB-5MS (30 m x 250 μm x 0.25 μm)
Temperature rise conditions: 40 ° C (0 min hold) → 320 ° C (0 min hold) (10 ° C / min)
Measurement mode: SCAN (m / z = 30 to 600)
Subsequently, as shown in FIG. 9B, 10 mg of epoxy encapsulating resin (trade name: R4212-2C, manufactured by Nagase Sangyo Co., Ltd.) was separately placed in the vial bottle 1, and each embodiment was replaced with a rubber stopper. / Cover the bottle mouth of the vial bottle 1 with the release film for the process prepared in the comparative example, prepare the release film for the process and the one sealed with a cap, and then prepare the vial bottle 2 having a size that can accommodate the vial bottle 1. The vial 1 is stored in the vial 2, sealed with a cap and a rubber stopper, heated at 120 ° C. for 30 minutes, and GC-MS measurement is performed by the static headspace method. The amount of outgas 2 in the vial 2 permeated through the mold film was measured. (Analysis 2)
For the process release film produced in each Example / Comparative Example, the following (Equation 1) was obtained from the outgas amount 1 obtained in Analysis 1 and the outgas amount 2 permeated through the process release film obtained in Analysis 2. ), The outgas permeability was calculated.
Outgas permeability = Outgas amount 2 / Outgas amount 1 x 100 (% by weight) (Equation 1)

(Measurement of oxygen permeability ^{[ml / (m 2 · day} · MPa)])
The process release film produced in each Example / Comparative Example was prepared using OX-TRAN2 / 21ML manufactured by Mocon Co., Ltd. in accordance with JIS K 7126, at a temperature of 20 ° C. and a humidity of 50% R.I. H. It was measured under the conditions of.

[Example 1]
As a heat-resistant resin layer B on which an inorganic gas barrier layer C is laminated, a biaxially stretched PET (polyethylene terephthalate) film B1 (manufactured by Mitsui Chemicals Tohcello Corporation, product name) having a thickness of 12 μm in which aluminum oxide (ALO film) is vapor-deposited on one side of the film. : TL-PET H) was used. The thermal dimensional change rate of the film B1 from 23 ° C. to 120 ° C. was 0.1% in the vertical (MD) direction and 0.4% in the horizontal (TD) direction. The melting point of the biaxially stretched PET film was 260 ° C., and the amount of heat of crystal melting was 38 J / g.

Unstretched 4-methyl-1-pentene copolymer resin film A1 was used as the release layers A and A'. Specifically, a 4-methyl-1-pentene copolymer resin (product name: TPX, brand name: MX022, melting point: 229 ° C., crystal melting calorific value: 22 J / g) manufactured by Mitsui Kagaku Co., Ltd. is melt-extruded at 270 ° C. By adjusting the slit width of the T-type die, a non-stretched film having a thickness of 15 μm was formed.
The unstretched 4-methyl-1-pentene copolymer resin film had a water contact angle of 105 ° on the surface, but one film surface had a water contact angle of 30 ° or less based on JIS R3257. , Corona treatment was applied from the viewpoint of improving the adhesiveness by the adhesive.
The thermal dimensional change rate of the 4-methyl-1-pentene copolymer resin film from 23 ° C. to 120 ° C. was 6.5% in the vertical (MD) direction and 3.1% in the horizontal (TD) direction. ..

(glue)
The following urethane-based adhesives were used as the adhesives used in the dry laminating process of laminating the films.
[Urethane adhesive]
Main agent: Takelac A-616 (manufactured by Mitsui Chemicals, Inc.). Hardener: Takenate A-65 (manufactured by Mitsui Chemicals, Inc.). The main agent and the curing agent were mixed so that the weight ratio (main agent: curing agent) was 16: 1, and ethyl acetate was used as the diluent.

(Manufacturing of release film)
One surface of a biaxially stretched PET (polyethylene terephthalate) film B1 on which an inorganic gas barrier layer C is laminated is coated with the above urethane adhesive at 1.5 g / m ² with a gravure coat, and unstretched 4-methyl-. After laminating the corona-treated surface of the 1-pentene copolymer resin film by dry laminating, 1.5 g / m of urethane adhesive is subsequently applied to the biaxially stretched PET (polyethylene terephthalate) film surface side of this laminated film. ^{The corona-treated surface of the non-stretched 4-methyl-1-pentene copolymer resin film coated with 2} is laminated by dry lamination to form a 5-layer structure (separation layer A / adhesive layer / gas barrier layer C / heat resistance). A release film for the process of resin layer B / adhesive layer / release layer A') was obtained.
The dry laminating conditions were a substrate width of 900 mm, a transport speed of 30 m / min, a drying temperature of 50 to 60 ° C., a laminating roll temperature of 50 ° C., and a roll pressure of 3.0 MPa.

The thermal dimensional change rate of the release film for the process from 23 ° C. to 120 ° C. was 0.8% in the vertical (MD) direction and 1.2% in the horizontal (TD) direction. The oxygen permeability at 25 ° C. and 50% relative humidity was 15 ml / m ² , day, MPa, and the outgas permeability was less than 0.5% by weight.
Table 1 shows the evaluation results of mold releasability, wrinkles, mold followability, and mold contamination. The release film shows good releasability that peels off naturally when the mold is opened, and there are no wrinkles in either the release film or the semiconductor package, that is, wrinkles are sufficiently suppressed, and the semiconductor package lacks resin. It showed good mold followability. In addition, no contamination of the mold was observed. That is, the process release film of Example 1 has good mold releasability, wrinkle suppression, and mold followability, and can effectively suppress mold contamination. Met.

[Example 2]
Instead of the biaxially stretched PET (polyethylene terephthalate) film B1 on which the inorganic gas barrier layer C is laminated, the OPP (biaxially stretched polypropylene) film B2 (biaxially stretched polypropylene having a thickness of 20 μm) on which the organic gas barrier layer C containing polyvinyl alcohol is laminated. Using a gas barrier film B2 (manufactured by Mitsui Kagaku Tohcello Co., Ltd., product name: A-OP AG) in which a polyvinyl alcohol copolymer gas barrier layer C is formed on one side of the film, a corona is used on the surface opposite to the surface of the organic gas barrier layer C. A release film for a process was prepared in the same manner as in Example 1 except for the treatment, and the release film was sealed and released, and the characteristics were evaluated. The thermal dimensional change rate of the film B2 from 23 ° C. to 120 ° C. was 0.2% in the vertical (MD) direction and −0.3% in the horizontal (TD) direction. The melting point of the OPP film B2 was 161 ° C., and the amount of heat of crystal melting was 93 J / g.
The thermal dimensional change rate from 23 ° C. to 120 ° C. of the produced release film for process was 2.4% in the vertical (MD) direction and 0.4% in the horizontal (TD) direction. The oxygen permeability at 25 ° C. and 50% relative humidity was 10 ml / m ² , day, MPa, and the outgas permeability was less than 0.5% by weight.
Table 1 shows the evaluation results of mold releasability, wrinkles, mold followability, and mold contamination. The release film shows good releasability that peels off naturally when the mold is opened, and there are no wrinkles in either the release film or the semiconductor package, that is, wrinkles are sufficiently suppressed, and the semiconductor package lacks resin. It showed good mold followability. In addition, no contamination of the mold was observed. That is, the process release film of Example 2 has good mold releasability, wrinkle suppression, and mold followability, and can effectively suppress mold contamination. Met.

[Example 3]
Gas barrier film B3 (manufactured by Mitsui Chemicals Tocello Co., Ltd., product name: V-OPOLE) (melting point) in which a polyvinylidene chloride copolymer is formed on one side of a biaxially stretched polypropylene film having a thickness of 20 μm instead of B2 as the heat-resistant resin layer B. A release film for a process was prepared in the same manner as in Example 2 except that the temperature was 160 ° C. and the amount of heat of crystal fusion: 91 J / g), sealed and released, and the characteristics were evaluated. The thermal dimensional change rate of the film B3 from 23 ° C. to 120 ° C. was 0.4% in the vertical (MD) direction and 0.7% in the horizontal (TD) direction. The melting point of the OPP film B2 was 160 ° C., and the amount of heat of crystal melting was 91 J / g.
The thermal dimensional change rate from 23 ° C. to 120 ° C. of the produced release film for process was 2.6% in the vertical (MD) direction and 0.7% in the horizontal (TD) direction. The oxygen permeability at 25 ° C. and 50% relative humidity was 50 ml / m ² , day, MPa, and the outgas permeability was less than 0.5% by weight.
Table 1 shows the evaluation results of mold releasability, wrinkles, mold followability, and mold contamination. The release film shows good releasability that peels off naturally when the mold is opened, and there are no wrinkles in either the release film or the semiconductor package, that is, wrinkles are sufficiently suppressed, and the semiconductor package lacks resin. It showed good mold followability. In addition, no contamination of the mold was observed. That is, the process release film of Example 3 has good mold releasability, wrinkle suppression, and mold followability, and can effectively suppress mold contamination. Met.
[Comparative Example 1]
Instead of the biaxially stretched PET (polyethylene terephthalate) film B1 in which the inorganic gas barrier layer is laminated, the OPP (biaxially stretched polypropylene) film B4 (biaxially stretched polypropylene film having a thickness of 20 μm) having no gas barrier layer (Mitsui Chemicals Tohcello Co., Ltd.) A release film for the process was prepared in the same manner as in Example 1 except that the product name: U-2)) manufactured by the company was used, and the release film was sealed and released to evaluate the characteristics. The thermal dimensional change rate of the OPP film B4 from 23 ° C. to 120 ° C. was 0.3% in the vertical (MD) direction and −0.4% in the horizontal (TD) direction. The melting point of the OPP film B4 was 161 ° C., and the amount of heat of crystal melting was 92 J / g.
The thermal dimensional change rate from 23 ° C. to 120 ° C. of the produced release film for process was 2.1% in the vertical (MD) direction and 1.3% in the horizontal (TD) direction. The oxygen permeability at 25 ° C. and 50% relative humidity was 15,000 ml / m ² · day · MPa, and the outgas permeability was 1.3% by weight.
Table 1 shows the evaluation results of mold releasability, wrinkles, mold followability, and mold contamination. The release film shows good releasability that peels off naturally when the mold is opened, and there are no wrinkles in either the release film or the semiconductor package, that is, wrinkles are sufficiently suppressed, and the semiconductor package lacks resin. It showed good mold followability, but the mold was contaminated. That is, although the process release film of Comparative Example 1 had good mold releasability, wrinkle suppression, and mold followability, it was not possible to effectively suppress mold contamination.

[Comparative Example 2]
No biaxially stretched PET (polyethylene terephthalate) film B1 and film A2 (4-methyl-1-pentene copolymer resin (product name: TPX, brand name: MX022) manufactured by Mitsui Chemicals Co., Ltd.) with a thickness of 50 μm. A stretched film formed (melting point: 229 ° C., heat of crystal melting: 21.7 J / g) is used alone as a release film for a process, and is sealed and released in the same manner as in Example 1. And evaluated the characteristics. The thermal dimensional change rate of the unstretched 4-methyl-1-pentene copolymer resin film A2 from 23 ° C. to 120 ° C. was 7.2% in the vertical (MD) direction and 3. in the horizontal (TD) direction. It was 6%. The oxygen permeability at 25 ° C. and a relative humidity of 50% was 300,000 ml / m ² , day, MPa, and the outgas permeability was 30% by weight.
Table 1 shows the evaluation results of mold releasability, wrinkles, mold followability, and mold contamination. The release film showed good mold releasability that peeled off naturally when the mold was opened, and showed good mold followability with no resin chipping in the semiconductor package. However, many wrinkles were observed, and the wrinkles could not be sufficiently suppressed. In addition, contamination was found in the mold. That is, although the process release film of Comparative Example 2 had good mold releasability and mold followability, wrinkles and mold contamination could not be effectively suppressed.
[Comparative Example 3]
Non-stretched polypropylene film B5 (manufactured by Mitsui Kagaku Tohcello Co., Ltd., product name) in which an inorganic gas barrier layer is laminated instead of the biaxially stretched PET (polyethylene terephthalate) film B1 in which an inorganic gas barrier layer is laminated. : S)) is a gas barrier film in which both sides are corona-treated and an aluminum oxide vapor-deposited film (ALO film) is applied to one side to a thickness of 10 nm). Was prepared, sealed and released, and its characteristics were evaluated. The thermal dimensional change rate of the unstretched polypropylene film B5 on which the inorganic gas barrier layer is laminated from 23 ° C. to 120 ° C. is 5.7% in the vertical (MD) direction and 6.2% in the horizontal (TD) direction. rice field. The melting point of the unstretched polypropylene film B5 was 162 ° C., and the amount of heat of crystal melting was 114 J / g.
The thermal dimensional change rate from 23 ° C. to 120 ° C. of the produced release film for process was 6.8% in the vertical (MD) direction and 7.2% in the horizontal (TD) direction. The oxygen permeability at 25 ° C. and 50% relative humidity was 30 ml / m ² , day, MPa, and the outgas permeability was less than 0.5% by weight.
Table 1 shows the evaluation results of mold releasability, wrinkles, mold followability, and mold contamination. Although it showed good mold releasability, it was not possible to effectively suppress the occurrence of wrinkles, and it was also judged as x in the mold contamination evaluation. It is presumed that as a result of the deterioration of the gas barrier property at the place where the film was wrinkled, the outgas permeability became large and the stain became apparent.

The mold release film of the present invention has a high level of mold releasability, wrinkle suppression, and mold followability that could not be realized by the prior art, and can effectively suppress mold contamination. By using it, a molded product obtained by sealing a semiconductor chip or the like with a resin can be easily released, and a molded product without appearance defects such as wrinkles and chips can be produced with high productivity and relatively low cost. It brings about a technical effect having high practical value that it can be manufactured, and has high utility in each field of industry including the semiconductor process industry.
Further, the process release film of the present invention can be used not only for semiconductor packages but also for various mold moldings in fiber-reinforced plastic molding processes, plastic lens molding processes, etc., and thus mold molding other than the semiconductor industry. It also has high availability in each field of the industry.

1, 1-2, 1-3: Release film 2: Upper mold 3: Suction port 4: Sealing resin 4-2: Semiconductor package 5: Lower mold 6: Semiconductor chip 7: Substrate 8: Molding mold 10, 20, 30, 40, 22: Release film 12: Heat-resistant resin layer B
14: Adhesive layers 16, 16A: Release layer A
16B: Release layer A'
17: Gas barrier layer C
24, 26: Roll 28: Molding mold 30: Upper mold 32: Lower mold 34: Semiconductor chip 34A: Substrate 36: Encapsulating resin 40, 44: Semiconductor package 51: Al plate 52, 65: Release film 53: SUS Frames 54 and 66: Encapsulating resin 61: Vial bottle 1
62: Vial bottle 2
63: Cap 64: Rubber stopper

Claims (17)

A release film for a process, which is a laminated film containing a release layer A and a heat-resistant resin layer B.
The contact angle of the release layer A with water is 90 ° to 130 °.
The rate of change in thermal dimensions from 23 ° C to 120 ° C in the lateral (TD) direction of the laminated film is 3% or less.
According to JIS K 7126 of the laminated film, the temperature is 20 ° C. and the humidity is 50%. H. A release film for a process in which the oxygen permeability measured under the above conditions is 1000 ml / m ² , day, MPa or less. A release film for a process, which is a laminated film containing a release layer A and a heat-resistant resin layer B.
The contact angle of the release layer A with water is 90 ° to 130 °.
The rate of change in thermal dimensions from 23 ° C to 120 ° C in the lateral (TD) direction of the laminated film is 3% or less.
The release film for the process having an outgas permeability of 1.0% by weight or less measured according to the following procedures (1) to (3) of the laminated film:
(1) Put 10 mg of the epoxy-sealed resin composition in the vial 1, seal it with a cap and a rubber stopper, heat it at 120 ° C. for 30 minutes, perform GC-MS measurement by the static headspace method, and carry out the GC-MS measurement in the vial. Measure the amount of outgas 1 in 1;
(2) Put 10 mg of the sealing resin in the vial bottle 1, prepare a vial bottle 1 with a release film for the process covered with the bottle mouth and seal it tightly, and then the size of the vial bottle 1 to be inserted. The vial bottle 2 of the above is prepared, the vial bottle 1 is stored in the vial bottle 2, and after sealing with a cap and a rubber stopper, the mixture is heated at 120 ° C. for 30 minutes and GC-MS measurement is performed by the static headspace method. Measure the amount of outgas 2 in the vial 2 permeated with the release film for the process;
(3) The outgas permeability of the release film for the process is calculated according to the following (Equation 1).
Outgas permeability = Outgas amount 2 / Outgas amount 1 x 100 (% by weight) (Equation 1) The claim that the sum of the thermal dimensional change rate from 23 ° C. to 120 ° C. in the lateral (TD) direction and the thermal dimensional change rate from 23 ° C. to 120 ° C. in the longitudinal (MD) direction of the laminated film is 6% or less. The process release film according to 1 or 2. The release film for a process according to any one of claims 1 to 3, wherein the heat-resistant resin layer B has a thermal dimensional change rate of 3% or less from 23 ° C. to 120 ° C. in the lateral (TD) direction. The sum of the thermal dimensional change rate from 23 ° C. to 120 ° C. in the lateral (TD) direction and the thermal dimensional change rate from 23 ° C. to 120 ° C. in the longitudinal (MD) direction of the heat-resistant resin layer B is 6% or less. The release film for a process according to claim 4. The release layer A according to any one of claims 1 to 5, wherein the release layer A contains a resin selected from the group consisting of a fluororesin, a 4-methyl-1-pentene (co) polymer, and a polystyrene-based resin. Release film for process. The release film for a process according to any one of claims 1 to 6, wherein the gas barrier layer C is laminated on the heat-resistant resin layer B. The process release film according to claim 7, wherein the gas barrier layer C is an inorganic layer or an organic layer. The release film for a process according to claim 7 or 8, wherein the protective resin layer D, which is an organic coating, is laminated on the gas barrier layer C. The heat-resistant resin layer JISK7221 differential scanning calorimetry according to the B (DSC) first KaiNoboru temperature heat of crystal fusion in step 20 J / g or more as measured by, at most 100 J / g, of claims 1 to 9 The release film for the process according to any one item. The laminated film further has a release layer A', and includes the release layer A, the heat-resistant resin layer B, and the release layer A'in this order.
The process release film according to any one of claims 1 to 10, wherein the release layer A'has a contact angle with water of 90 ° to 130 °. 11. At least one of the release layer A and the release layer A'contains a resin selected from the group consisting of a fluororesin, a 4-methyl-1-pentene (co) polymer, and a polystyrene-based resin. The release film for the process described in. The process release film according to any one of claims 1 to 12, which is used in a sealing process using a thermosetting resin. The process release film according to any one of claims 1 to 13, which is used in a semiconductor encapsulation process. The process release film according to any one of claims 1 to 12, which is used in a fiber reinforced plastic molding process or a plastic lens molding process. A method for manufacturing resin-sealed semiconductors.
The process of arranging the resin-sealed semiconductor device at a predetermined position in the molding die, and
A step of arranging the process release film according to any one of claims 1 to 14 on the inner surface of the molding die so that the release layer A faces the semiconductor device.
A step of injecting and molding a sealing resin between the semiconductor device and the process release film after molding the molding die.
The above-mentioned method for manufacturing a resin-sealed semiconductor. A method for manufacturing resin-sealed semiconductors.
The process of arranging the resin-sealed semiconductor device at a predetermined position in the molding die, and
A step of arranging the process release film according to claim 11 or 12 on the inner surface of the molding die so that the release layer A'is opposed to the semiconductor device.
A step of injecting and molding a sealing resin between the semiconductor device and the process release film after molding the molding die.
The above-mentioned method for manufacturing a resin-sealed semiconductor.

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