JPWO2020136903A1 - Manufacturing method of semiconductor devices, film-like adhesives and dicing / die bonding integrated film - Google Patents

Abstract

The method for manufacturing a semiconductor device according to the present disclosure includes a step of preparing a film-like adhesive for adhering a semiconductor element and a member on which the semiconductor element is mounted, and a film-like adhesive and a film-like adhesive on the surface of the member. The value of the surface free energy of the film-like adhesive E1 (mJ / m2) and the value of the surface free energy of the member include the step of crimping the semiconductor element to the surface of the member in a state where the semiconductor elements are laminated. The absolute value of the difference of E2 (mJ / m2) is in the range of 6.0 to 10.0.

Description

The present disclosure relates to a method for manufacturing a semiconductor device, a film-like adhesive, and a dicing / die bonding integrated film.

Conventionally, in the manufacturing process of a semiconductor device, silver paste has been mainly used for joining a semiconductor element and a support member. However, with the recent miniaturization and integration of semiconductor devices, there is a tendency that problems occur in wire bonding due to the protrusion of silver paste or the inclination of the semiconductor devices. When an adhesive composition is used instead of the silver paste, there are problems that it is difficult to make the thickness of the adhesive layer sufficiently uniform, and voids (voids) are generated in the adhesive layer.

In recent years, film-like adhesives have come to be used for joining semiconductor devices and support members. For example, Patent Document 1 discloses a dicing / die bonding combined sheet including a base material, a wire embedding layer, and an insulating layer. By performing dicing with the insulating layer of this sheet and the wafer bonded together, the semiconductor wafer and the wire embedded layer are separated into individual pieces. The semiconductor element and the support member are joined by thermocompression bonding the semiconductor element to the support member via the wire embedded layer.

By the way, as a form of a semiconductor device, a stacked MCP (Multi Chip Package) having a configuration in which semiconductor elements are stacked in multiple stages has become widespread. Examples of the stacked MCP include a wire-embedded semiconductor package and a chip-embedded semiconductor package (see Patent Document 2). The adhesive film used in the manufacture of wire-embedded semiconductor packages is called FOW (Film Over Wire). An adhesive film used in the manufacture of chip-embedded semiconductor packages is called FOD (Film Over Die). These adhesive films are required to have excellent embedding property in a wire or a semiconductor element.

Japanese Unexamined Patent Publication No. 2007-53240 Japanese Unexamined Patent Publication No. 2014-175459

As the size of semiconductor elements (chips) becomes smaller, the pressing force per unit area tends to become excessively large in the crimping process in the manufacturing process of semiconductor packages. This may cause a phenomenon in which the adhesive composition constituting the adhesive film protrudes from the semiconductor element (hereinafter referred to as “bleed”), or the adhesive film may be excessively crushed and cause electrical defects. In particular, in order to improve the embedding property of the adhesive film (FOD) used for manufacturing a chip-embedded semiconductor package, bleeding becomes remarkable when the FOD composition is changed to increase the fluidity in the crimping process. For example, the protruding adhesive composition may rise to the upper surface of the semiconductor device, which may cause electrical failure or wire bonding failure.

The present disclosure provides a method for manufacturing a semiconductor device capable of sufficiently suppressing bleeding in a crimping process. The present disclosure also provides a film-like adhesive and a dicing / die bonding integrated film applicable to this manufacturing method.

The method for manufacturing a semiconductor device according to the present disclosure includes a step of preparing a film-like adhesive for adhering a semiconductor element and a member on which the semiconductor element is mounted, and a film-like adhesive and a film-like adhesive on the surface of the member. _{The value of the surface free energy of the film-like adhesive E 1} (mJ / m ² ) and the value of the surface free energy of the member include the step of crimping the semiconductor element to the surface of the member in a state where the semiconductor elements are laminated. The absolute value of the difference of E ₂ (mJ / m ² ) is in the range of 6.0 to 10.0.

According to the above-mentioned manufacturing method, when _{the absolute value of the difference between E 1} and E ₂ is 6.0 or more, it is possible to prevent the film-like adhesive from being excessively wetted and spread on the above-mentioned member in the crimping step. As a result, bleeding can be sufficiently suppressed. On the other hand, when _{the absolute value of the difference between E 1} and E ₂ is 10.0 or less, excellent embedding property can be achieved even if the member has a chip and / or a wire to be embedded.

By the method of the present disclosure, a chip-embedded semiconductor package may be manufactured, or a wire-embedded semiconductor package may be manufactured. When manufacturing a chip-embedded semiconductor package, a structure including a substrate and a chip mounted on the surface of the substrate is prepared as the above member, and the substrate is embedded so that the chip is embedded in a film-like adhesive. The semiconductor element may be crimped to the surface. When manufacturing a wire-embedded semiconductor package, a structure including a substrate and a wire provided on the surface of the substrate is prepared as the above member, and the substrate is embedded so that the wire is embedded in a film-like adhesive. The semiconductor element may be crimped to the surface.

In the manufacturing method of the present disclosure, a dicing / die bonding integrated film containing a film-like adhesive, a pressure-sensitive adhesive layer, and a base film, which are laminated in this order, may be used. That is, the manufacturing method of the present disclosure includes a step of preparing a dicing / die bonding integrated film, a step of bonding the film-shaped adhesive and the wafer of the dicing / die bonding integrated film, and a step of bonding to the film-shaped adhesive. A step of individualizing a wafer in a state of being into a plurality of semiconductor elements, and a step of picking up a laminate containing an adhesive piece formed by individualizing a film-like adhesive and a semiconductor element from an adhesive layer. And may include a step of crimping the laminated body to the above member and a step of curing the adhesive piece by heat treatment.

The film-like adhesive according to the present disclosure is made of a thermosetting resin composition and has a surface free energy value E ₁ of 38 to 41 mJ / m ² . Since E ₁ is in this range, _{the absolute value of the difference between E 1} and E ₂ is likely to be in the range of 6.0 to 10.0. The surface free energy value E ₂ of the member is, for example, 46 to 48 mJ / m ² .

In order to prepare a film-like adhesive having a surface free energy value E ₁ in the above range, for example, one of the following plurality of items relating to the composition of the thermosetting resin composition constituting the film-like adhesive. Alternatively, a plurality of items may be adopted.
The content of the epoxy resin that is liquid at 25 ° C. (based on the total mass of the epoxy resin contained in the thermosetting resin composition) is 5 to 10% by mass.
-The thermosetting resin composition contains an epoxy resin having an alicyclic structure, a curing agent (for example, a phenol resin), and an elastoma (for example, an acrylic resin).
The content of the epoxy resin having an alicyclic structure (based on the total mass of the epoxy resin contained in the thermosetting resin composition) is 5 to 30% by mass.
-The thermosetting resin composition contains an inorganic filler.
-The thermosetting resin composition contains a curing accelerator.

The film-like adhesive may form an adhesive film together with the base film. That is, another aspect of the present disclosure provides an adhesive film comprising a film-like adhesive and a substrate film provided on one surface of the film-like adhesive. The film-like adhesive may form a dicing / die bonding integrated film together with the pressure-sensitive adhesive layer and the base film. That is, another aspect of the present disclosure provides a dicing-diebonding integrated film comprising a film-like adhesive, a pressure-sensitive adhesive layer, and a base film, which are laminated in this order. The dicing / die bonding integrated film may further include a protective film provided so as to cover the film-like adhesive.

According to the present disclosure, there is provided a method for manufacturing a semiconductor device capable of sufficiently suppressing bleeding in a crimping process. Further, according to the present disclosure, a film-like adhesive and a dicing / die bonding integrated film applicable to this manufacturing method are provided.

FIG. 1 is a cross-sectional view schematically showing an example of a semiconductor package. FIG. 2 is a cross-sectional view schematically showing an example of a laminate composed of an adhesive piece and a second semiconductor element. FIG. 3 is a cross-sectional view schematically showing a process of manufacturing the semiconductor package shown in FIG. FIG. 4 is a cross-sectional view schematically showing a process of manufacturing the semiconductor package shown in FIG. FIG. 5 is a cross-sectional view schematically showing a process of manufacturing the semiconductor package shown in FIG. FIG. 6 is a cross-sectional view schematically showing a process of manufacturing the semiconductor package shown in FIG. 7 (a) to 7 (e) are cross-sectional views schematically showing a process of manufacturing a laminate composed of an adhesive piece and a second semiconductor element.

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the following description, the same or corresponding parts will be designated by the same reference numerals, and duplicate description will be omitted. In addition, the positional relationship such as up, down, left, and right shall be based on the positional relationship shown in the drawings unless otherwise specified. Furthermore, the dimensional ratios in the drawings are not limited to the ratios shown. The description of "(meth) acrylic" in the present specification means "acrylic" and the corresponding "methacryl".

<Semiconductor package>
FIG. 1 is a cross-sectional view schematically showing a chip-embedded semiconductor package according to the present embodiment. In the semiconductor package 100 (semiconductor device) shown in this figure, the substrate 10, the first semiconductor element Wa (chip) mounted on the surface of the substrate 10, and the first semiconductor element Wa are sealed. 1. The sealing layer 20 includes a second semiconductor element Wb arranged above the first semiconductor element Wa, and a second sealing layer 40 that seals the second semiconductor element Wb. ..

The substrate 10 has circuit patterns 10a and 10b on its surface. From the viewpoint of suppressing the warp of the semiconductor package 100, the thickness of the substrate 10 is, for example, 90 to 180 μm, and may be 90 to 140 μm. The substrate 10 may be an organic substrate or a metal substrate such as a lead frame.

In the present embodiment, the first semiconductor element Wa is a controller chip for driving the semiconductor package 100. The first semiconductor element Wa is adhered to the circuit pattern 10a via the adhesive 15, and is also connected to the circuit pattern 10b via k. The shape of the first semiconductor element Wa in a plan view is, for example, a rectangle (square or rectangle). The length of one side of the first semiconductor element Wa is, for example, 6 mm or less, and may be 2 to 5 mm or 1 to 4 mm. The thickness of the first semiconductor element Wa is, for example, 10 to 150 μm, and may be 20 to 100 μm.

The second semiconductor element Wb has a larger area than the first semiconductor element Wa. The second semiconductor element Wb is mounted on the substrate 10 via the first sealing layer 20 so that the entire first semiconductor element Wa and a part of the circuit pattern 10b are covered. The shape of the second semiconductor element Wb in a plan view is, for example, a rectangle (square or rectangle). The length of one side of the second semiconductor element Wb is, for example, 20 mm or less, and may be 4 to 20 mm or 4 to 12 mm. The thickness of the second semiconductor element Wb is, for example, 10 to 170 μm, and may be 20 to 120 μm. The second semiconductor element Wb is connected to the circuit pattern 10b via the second wire 12 and is sealed by the second sealing layer 40.

The first sealing layer 20 is made of a cured product of the adhesive piece 20P (see FIG. 2). As shown in FIG. 2, the adhesive piece 20P and the second semiconductor element Wb have substantially the same size. The laminate 30 shown in FIG. 2 is composed of an adhesive piece 20P and a second semiconductor element Wb, and is also referred to as a semiconductor element with an adhesive. The laminate 30 is manufactured through a dicing step and a pickup step as described later (see FIG. 7).

<Manufacturing method of semiconductor package>
The manufacturing method of the semiconductor package 100 will be described. First, as shown in FIG. 3, a structure 50 including a substrate 10 and a first semiconductor element Wa mounted on the substrate 10 is manufactured. That is, the first semiconductor element Wa is arranged on the surface of the substrate 10 via the adhesive 15. After that, the first semiconductor element Wa and the circuit pattern 10b are electrically connected by the first wire 11.

Next, as shown in FIG. 4, the adhesive piece 20P of the laminated body 30 prepared separately is pressure-bonded to the substrate 10. As a result, the first semiconductor element Wa and the first wire 11 are embedded in the adhesive piece 20P. In the crimping process, in view of achieving and excellent embedding properties suppressed bleeding, value E ₁ of the surface free energy of the adhesive strip 20P _(mJ / m ²⁾ and the value of surface free energy of the substrate 10 E ₂ ( the absolute value of the difference mJ / ^{m 2)} is in the range of 6.0 to 10.0. When _{the absolute value of the difference between E 1} and E ₂ is 6.0 or more, it is possible to prevent the adhesive piece 20P from being excessively wet and spread with respect to the substrate 10 in the crimping process, whereby bleeding can be sufficiently performed. Can be suppressed. On the other hand, when _{the absolute value of the difference between E 1} and E ₂ is 10.0 or less, excellent embedding property can be achieved. The lower limit of the absolute value of the difference between E ₁ and E _{2 may be 6.6, 7.0 or 7.6.} The upper limit of the absolute value of the difference between E ₁ and E _{2 may be 9.6, 9.0 or 8.6.} The absolute value of the difference between E ₁ and E ₂ may be in the above range, and E ₁ may be larger than E _{2 or E 2} may be larger than E _1.

_{The value E 1} of the surface free energy of the adhesive piece 20P is, for example, 37 to 41 mJ / m ² , and may be 38 to 40 mJ / m ^2. Since E ₁ is in this range, _{the absolute value of the difference between E 1} and E ₂ is likely to be in the range of 6.0 to 10.0.

The surface free energy value E ₂ of the substrate 10 is, for example, 30 to 50 mJ / m ² , and may be 32 to 49 mJ / m ² or 34 to 48 mJ / m ^2. Since E ₂ is in this range, _{the absolute value of the difference between E 1} and E ₂ is likely to be in the range of 6.0 to 10.0. The value of E ₂ can be adjusted by subjecting the region of the surface of the substrate 10 where the adhesive piece 20P is in contact and the vicinity thereof to a modification treatment as necessary. _{More specifically, the value of E 2} can be adjusted by subjecting it to plasma treatment or by using a solder resist that imparts polarity.

The thickness of the adhesive piece 20P may be appropriately set according to the thickness of the first semiconductor element Wa and the like, and may be, for example, 20 to 200 μm, 30 to 200 μm, or 40 to 150 μm. .. By setting the thickness of the adhesive piece 20P within the above range, the distance between the first semiconductor element Wa and the second semiconductor element Wb (distance G in FIG. 5) can be sufficiently secured. The distance G is preferably, for example, 50 μm or more, and may be 50 to 75 μm or 50 to 80 μm.

The pressure-bonding of the adhesive piece 20P to the substrate 10 is preferably carried out, for example, under the conditions of 80 to 180 ° C. and 0.01 to 0.50 MPa for 0.5 to 3.0 seconds. Next, the adhesive piece 20P is cured by heating. This curing treatment is preferably carried out at 60 to 175 ° C. and 0.01 to 1.0 MPa for 5 minutes or longer. As a result, the first semiconductor element Wa is sealed with the cured product (first sealing layer 20) of the adhesive piece 20P (see FIG. 6). The curing treatment of the adhesive piece 20P may be carried out in a pressurized atmosphere from the viewpoint of reducing voids. The semiconductor package 100 is completed by electrically connecting the second semiconductor element Wb and the circuit pattern 10b with the second wire 12 and then sealing the second semiconductor element Wb with the second sealing layer 40. (See Fig. 1).

<Method of manufacturing semiconductor devices with adhesive>
An example of a method for manufacturing the laminate 30 (semiconductor device with an adhesive) shown in FIG. 2 will be described with reference to FIGS. 7 (a) to 7 (e). First, a dicing / die bonding integrated film 8 (hereinafter, referred to as “film 8” in some cases) is placed in a predetermined device (not shown). The film 8 includes a base film 1, an adhesive layer 2, and an adhesive layer 20A (film-like adhesive) in this order. The base film 1 is, for example, a polyethylene terephthalate film (PET film). The semiconductor wafer W is, for example, a thin semiconductor wafer having a thickness of 10 to 100 μm. The semiconductor wafer W may be single crystal silicon or a compound semiconductor such as polycrystalline silicon, various ceramics, and gallium arsenide. The film 8 may be further provided with a protective film (not shown) provided so as to cover the adhesive layer 20A.

As shown in FIGS. 7 (a) and 7 (b), the film 8 is attached so that the adhesive layer 20A is in contact with one surface of the semiconductor wafer W. This step is preferably carried out under temperature conditions of 50 to 120 ° C, more preferably 60 to 100 ° C. When the temperature is 50 ° C. or higher, good adhesion of the semiconductor wafer W to the adhesive layer 20A can be obtained, and when the temperature is 120 ° C. or lower, the adhesive layer 20A may excessively flow in this step. It is suppressed.

As shown in FIG. 7 (c), the semiconductor wafer W, the adhesive layer 2 and the adhesive layer 20A are diced. As a result, the semiconductor wafer W is fragmented into a semiconductor element Wb. The adhesive layer 20A is also individualized to form an adhesive piece 20P. Examples of the dicing method include a method using a rotary blade or a laser. The semiconductor wafer W may be thinned by grinding the semiconductor wafer W prior to dicing the semiconductor wafer W.

Next, when the pressure-sensitive adhesive layer 2 is, for example, a UV curable type, as shown in FIG. 7D, the pressure-sensitive adhesive layer 2 is cured by irradiating the pressure-sensitive adhesive layer 2 with ultraviolet rays to cure the pressure-sensitive adhesive layer 2. The adhesive force between 2 and the adhesive piece 20P is reduced. After irradiation with ultraviolet rays, as shown in FIG. 7 (e), the semiconductor elements Wa are separated from each other by expanding the base film 1 under normal temperature or cooling conditions, and the semiconductor elements Wa are pushed up from the pressure-sensitive adhesive layer 2 by the needle 42. The adhesive piece 20P of the laminated body 30 is peeled off, and the laminated body 30 is sucked and picked up by the suction collet 44. As shown in FIG. 4, the laminate 30 thus obtained is used for manufacturing the semiconductor package 100.

<Dicing / die bonding integrated film and its manufacturing method>
The dicing / die bonding integrated film 8 shown in FIG. 7A and a method for manufacturing the same will be described. As described above, the film 8 includes the base film 1 (for example, PET film), the pressure-sensitive adhesive layer 2, and the adhesive layer 20A (adhesive film) in this order. The method for producing the film 8 is a step of applying a varnish of a thermosetting resin composition containing an epoxy resin or the like onto a film (not shown), and an adhesive by heating and drying the applied varnish at 50 to 150 ° C. The step of forming the layer 20A and the step of adhering the adhesive layer 20A and the pressure-sensitive adhesive layer 2 are included.

The adhesive layer 20A is formed through, for example, a step of applying a varnish containing an epoxy resin, a curing agent, and an elastomer on the film, and a step of drying the coating film formed on the film. The varnish may further contain an inorganic filler, a curing accelerator and the like, if necessary. The varnish can be prepared by mixing or kneading a material such as an epoxy resin in a solvent. Mixing or kneading can be performed by using a disperser such as a normal stirrer, a raft machine, a three-roll machine, or a ball mill, and combining these as appropriate. The details of the varnish will be described later.

The film to which the varnish is applied is not particularly limited, and examples thereof include polyester film, polypropylene film (OPP film, etc.), polyethylene terephthalate film, polyimide film, polyetherimide film, polyethernaphthalate film, and methylpentene film. Be done.

As a method for applying the varnish to the film, a known method can be used, and examples thereof include a knife coating method, a roll coating method, a spray coating method, a gravure coating method, a bar coating method, and a curtain coating method. The heat-drying condition may be any condition as long as the solvent used is sufficiently volatilized, and for example, it can be heated at 50 to 150 ° C. for 1 to 30 minutes. The heat drying may be carried out by gradually raising the temperature in the range of 50 to 150 ° C. By volatilizing the solvent contained in the varnish by heating and drying, a laminated film of the film and the adhesive layer 20A can be obtained.

The film 8 can be obtained by laminating the laminated film obtained as described above and the dicing film (laminated body of the base film 1 and the pressure-sensitive adhesive layer 2). Examples of the base film 1 include plastic films such as polytetrafluoroethylene film, polyethylene terephthalate film, polyethylene film, polypropylene film, polymethylpentene film, and polyimide film. Further, the base film 1 may be subjected to surface treatment such as primer coating, UV treatment, corona discharge treatment, polishing treatment, and etching treatment, if necessary. The pressure-sensitive adhesive layer 2 may be a UV curable type or a pressure-sensitive type. As the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer 2, a pressure-sensitive adhesive conventionally used for a dicing film may be used. The thickness of the pressure-sensitive adhesive layer 2 is, for example, 60 to 200 μm and may be 70 to 170 μm from the viewpoint of economy and handleability of the film.

<Varnish for forming adhesive layer>
The varnish for forming the adhesive layer 20A will be described in detail. The adhesive piece 20P is an individualized adhesive layer 20A, and both are made of the same thermosetting resin composition. The adhesive layer 20A and the adhesive piece 20P are in a semi-cured state (B stage) because they have undergone a heat treatment for volatilizing the solvent, and are in a completely cured product (C stage) state by the subsequent curing treatment.

As described above, the varnish for forming the adhesive layer contains an epoxy resin, a curing agent, an elastomer, and if necessary, further contains an inorganic filler, a curing accelerator, and the like. The solvent for preparing the varnish is not limited as long as it can uniformly dissolve, knead or disperse each of the above components, and is, for example, a ketone solvent such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, dimethylformamide, dimethyl. Acetamide, N-methylpyrrolidone, toluene and xylene can be used. It is preferable to use methyl ethyl ketone or cyclohexanone because the drying speed is fast and the price is low.

(Epoxy resin)
The structure of the epoxy resin is not particularly limited, but a resin having an alicyclic structure is preferable from the viewpoint of compatibility. _{From the viewpoint that the value E 1} of the surface free energy of the adhesive layer 20A is in the range of 38 to 41 mJ / m ² , the content of the epoxy resin having an alicyclic structure is the total mass of the epoxy resin contained in the adhesive layer 20A. By reference, for example, it may be 5 to 40% by mass, 6 to 35% by mass, or 7 to 34% by mass. From the same viewpoint, the content of the epoxy resin that is liquid at 25 ° C. is, for example, 5 to 30% by mass, 7 to 25% by mass, or 8 to 8 to 30% by mass based on the total mass of the epoxy resin contained in the adhesive layer 20A. It may be 23% by mass.

Commercially available epoxy resins include, for example, dicyclopentadiene type epoxy resin HP-7200L (manufactured by DIC Corporation), HP-7200 (manufactured by DIC Corporation), XD-1000 (manufactured by Nippon Kayaku Co., Ltd.), Celoxide 2021P (manufactured by DIC CORPORATION), Celoxide 20281 (manufactured by DIC CORPORATION), Syna-Epoxy28 (manufactured by SYNASIA), bis A type epoxy resin YD-128 (manufactured by Mitsubishi Chemical Corporation), bis F type epoxy Examples thereof include the resin EXA-830-CRP (manufactured by DIC Corporation). These may be used alone or in combination of two or more.

Aromatic epoxy resin may be used as a thermosetting resin. Examples of the aromatic epoxy resin include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, phenol novolac type epoxy resin, cresol novolak type epoxy resin, bisphenol A novolak type epoxy resin, and bisphenol F novolak type epoxy. Resin, stylben type epoxy resin, triazine skeleton-containing epoxy resin, fluorene skeleton-containing epoxy resin, triphenolphenol methane type epoxy resin, biphenyl type epoxy resin, xylylene type epoxy resin, biphenyl aralkyl type epoxy resin, naphthalene type epoxy resin, polyfunctional Examples thereof include diglycidyl ether compounds of polycyclic aromatics such as phenols and anthracene. These may be used alone or in combination of two or more.

(Hardener)
Examples of the curing agent include phenolic resins, ester compounds, aromatic amines, aliphatic amines and acid anhydrides. Of these, phenolic resins are preferable and are not particularly limited from the viewpoint of reactivity and stability over time.

Commercially available phenolic resin products include, for example, Phenolite KA and TD series manufactured by DIC Corporation, Millex XLC-series and XL series manufactured by Mitsui Kagaku Co., Ltd. (for example, Millex XLC-LL), and Air Water Inc. ) (For example, HE100C-30) and MEHC-7800 series (for example, MEHC-7800-4S) manufactured by Meiwa Kasei Co., Ltd. These may be used alone or in combination of two or more. From the viewpoint of heat resistance, the water absorption rate after being put into a constant temperature and humidity chamber at 85 ° C. and 85% RH for 48 hours is 2% by mass or less, and the heating mass reduction rate at 350 ° C. measured by a thermogravimetric analyzer (TGA). It is preferable that the temperature (heating rate: 5 ° C./min, atmosphere: nitrogen) is less than 5% by mass.

From the viewpoint of curability, the compounding amount of the epoxy resin and the phenol resin has an equivalent ratio of the epoxy equivalent to the hydroxyl group, preferably 0.30 / 0.70 to 0.70 / 0.30, more preferably 0. 35 / 0.65 to 0.65 / 0.35, more preferably 0.40 / 0.60 to 0.60 / 0.40, and particularly preferably 0.45 / 0.55 to 0.55 / 0. 45. When the compounding ratio is within the above range, it is easy to achieve a sufficiently high level of both curability and fluidity.

(Elastomer)
Examples of the elastoma include acrylic resin, polyester resin, polyamide resin, polyimide resin, silicone resin, polybutadiene, acrylonitrile, epoxy-modified polybutadiene, maleic anhydride-modified polybutadiene, phenol-modified polybutadiene and carboxy-modified acrylonitrile.

From the viewpoint of solubility in a solvent and fluidity, an acrylic resin is preferable as the elastoma, and a functional monomer having an epoxy group such as glycidyl acrylate or glycidyl methacrylate or a glycidyl group as a crosslinkable functional group is polymerized. Acrylic resins such as epoxy group-containing (meth) acrylic copolymers are more preferable. Among the acrylic resins, an epoxy group-containing (meth) acrylic acid ester copolymer and an epoxy group-containing acrylic rubber are preferable, and an epoxy group-containing acrylic rubber is more preferable. The epoxy group-containing acrylic rubber is a rubber having an epoxy group, which is mainly composed of an acrylic acid ester as a main component, a copolymer such as butyl acrylate and acrylonitrile, and a copolymer such as ethyl acrylate and acrylonitrile. The acrylic resin may have not only an epoxy group but also a crosslinkable functional group such as an alcoholic or phenolic hydroxyl group or a carboxyl group.

Commercially available acrylic resin products include SG-70L, SG-708-6, WS-023 EK30, SG-280 EK23, and SG-P3 solvent-changed products manufactured by Nagase Chemtech Co., Ltd. (trade name, acrylic rubber, weight). Average molecular weight: 800,000, Tg: 12 ° C., solvent is cyclohexanone) and the like.

The glass transition temperature (Tg) of the acrylic resin is preferably -50 to 50 ° C, more preferably -30 to 30 ° C. The weight average molecular weight (Mw) of the acrylic resin is preferably 100,000 to 3,000,000, more preferably 500,000 to 2,000,000. By blending an acrylic resin in this range with Mw in a thermosetting resin composition, the thermosetting resin composition can be easily formed into a film, and the strength, flexibility, and tackiness of the film can be appropriately controlled. It's easy to do. In addition to this, both reflowability and implantability tend to improve. Here, Mw means a value measured by gel permeation chromatography (GPC) and converted using a calibration curve made of standard polystyrene. By using an acrylic resin having a narrow molecular weight distribution, it tends to be possible to form an adhesive layer having excellent embedding property and high elasticity.

The amount of the acrylic resin contained in the adhesive layer 20A is preferably 20 to 200 parts by mass, more preferably 30 to 100 parts by mass with respect to 100 parts by mass of the total of the epoxy resin and the epoxy resin curing agent. .. Within this range, control of fluidity during molding, handleability at high temperature, and embedding property can be further improved.

(Inorganic filler)
Examples of inorganic fillers include aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, calcium silicate, magnesium silicate, calcium oxide, magnesium oxide, aluminum oxide, aluminum nitride, aluminum borate whisker, boron nitride and crystalline. Examples include silica and amorphous silica. These may be used alone or in combination of two or more. From the viewpoint of improving the thermal conductivity of the adhesive layer 20A, it is preferable to contain aluminum oxide, aluminum nitride, boron nitride, crystalline silica or amorphous silica as the inorganic filler. From the viewpoint of adjusting the melt viscosity of the adhesive layer 20A and imparting thixotropic properties to the adhesive composition, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, calcium silicate, magnesium silicate, calcium oxide, It is preferable to use magnesium oxide, aluminum oxide, crystalline silica or amorphous silica.

The average particle size of the inorganic filler is preferably 0.005 μm to 0.5 μm, more preferably 0.05 to 0.3 μm from the viewpoint of improving the adhesiveness. The surface of the inorganic filler is preferably chemically modified from the viewpoint of compatibility with the solvent and the resin component and adhesive strength. Silane coupling agents are suitable as materials for chemically modifying the surface. Examples of the functional group of the silane coupling agent include a vinyl group, an acryloyl group, an epoxy group, a mercapto group, an amino group, a diamino group, an alkoxy group and an ethoxy group.

From the viewpoint of controlling the fluidity and breakability of the adhesive layer 20A, and the tensile elastic modulus and adhesive force after curing, the content of the inorganic filler is 10 to 90 with respect to 100 parts by mass of the resin component of the adhesive layer 20A. It is preferably parts by mass, more preferably 10 to 50 parts by mass. When the content of the inorganic filler is 10 parts by mass or more, the dicing property of the adhesive layer 20A is likely to be improved, and sufficient adhesive force is likely to be exhibited after curing. On the other hand, when the content of the inorganic filler is 90 parts by mass or less, it is easy to sufficiently secure the fluidity of the adhesive layer 20A, and it is possible to prevent the elastic modulus from becoming excessively high after curing.

(Hardening accelerator)
Examples of the curing accelerator include imidazoles and derivatives thereof, organic phosphorus compounds, secondary amines, tertiary amines, and quaternary ammonium salts. An imidazole-based compound is preferable from the viewpoint of appropriate reactivity. Examples of the imidazoles include 2-methylimidazole, 1-benzyl-2-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-methylimidazole and the like. These may be used alone or in combination of two or more.

The content of the curing accelerator in the adhesive layer 20A is preferably 0.04 to 3 parts by mass, more preferably 0.04 to 0.2 parts by mass with respect to 100 parts by mass of the total of the epoxy resin and the epoxy resin curing agent. .. When the amount of the curing accelerator added is in this range, both curability and reliability can be achieved.

Although the embodiments have been described in detail in the present disclosure, the present invention is not limited to the above embodiments. For example, in the above embodiment, the chip-embedded semiconductor package has been exemplified, but the present disclosure may be applied to the manufacture of a wire-embedded semiconductor package and other semiconductor devices.

Hereinafter, the present disclosure will be described in more detail by way of examples, but these examples do not limit the present invention.

(Examples 1 to 7 and Comparative Examples 1 to 2)
The following materials were mixed at the blending ratios (parts by mass) shown in Tables 1 to 3 to prepare a varnish. Cyclohexanone was used as a solvent, and the solid content ratio of the varnish was 40% by mass. The varnish was filtered with a 100 mesh filter and vacuum defoamed. As a film to which the varnish was applied, a polyethylene terephthalate (PET) film (thickness 38 μm) subjected to a mold release treatment was prepared. The varnish after vacuum defoaming was applied onto the mold-released surface of the PET film. The applied varnish was heated and dried in two steps at 90 ° C. for 5 minutes and then at 140 ° C. for 5 minutes. In this way, as the adhesive film according to the examples and the comparative examples, a laminated film having a PET film and a film-like adhesive (thickness 110 μm) in a B stage state (semi-cured state) formed on the surface thereof is produced. bottom.

[material]
<Epoxy resin>
(A1) ... XD-1000: (trade name, manufactured by Nippon Kayaku Co., Ltd., cyclopentadiene type epoxy resin, alicyclic structure, solid at 25 ° C)
(A2) ... Celoxide 2021P: (trade name, manufactured by Daicel Corporation, alicyclic structure, solid at 25 ° C)
(A3) ... HP-7200L: (trade name, manufactured by DIC Corporation, cyclopentadiene type epoxy resin, alicyclic structure, solid at 25 ° C.)
(A4) ... EHPE3150 (trade name, manufactured by Daicel Corporation, alicyclic structure, solid at 25 ° C)
(A5) ... VG3101L (trade name, manufactured by Printec Co., Ltd., polyfunctional epoxy resin, solid at 25 ° C)
(A6) ... YDCN-700-10: (Product name, manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., cresol novolac type epoxy resin, solid at 25 ° C)
(A7) ... EXA-830CRP: (trade name, manufactured by DIC Corporation, liquid bisphenol F type epoxy resin, liquid at 25 ° C)
<Curing agent>
(B1) ... XLC-LL: (trade name, manufactured by Mitsui Chemicals, Inc., phenylaralkyl-type phenol resin)
(B2) ... LF-4871: (trade name, manufactured by DIC Corporation, BPA novolak type phenol resin)
(B3) ... HE-100C-30: (trade name, manufactured by Air Water Inc., phenylarakil type phenol resin)
<Elastomer>
(C1) ... SG-P3 solvent modified product (trade name, manufactured by Nagase ChemteX Corporation, acrylic rubber, weight average molecular weight: 800,000, Tg: 12 ° C., solvent is cyclohexanone)
(C2) ... SG-70L: (trade name, manufactured by Nagase ChemteX Corporation, acrylic rubber, weight average molecular weight 900,000, acid value 5 mgKOH / g, Tg: -13 ° C)
<Inorganic filler>
SC2050-HLG: (trade name, manufactured by Admatex Co., Ltd., silica filler dispersion, average particle size 0.50 μm)
<Hardening accelerator>
-Curesol 2PZ-CN: (trade name, manufactured by Shikoku Chemicals Corporation, 1-cyanoethyl-2-phenylimidazole)

[Evaluation of film-like adhesive]
The surface free energy and bleeding of the film-like adhesives according to Examples and Comparative Examples were evaluated.

<Measurement of surface free energy>
The surface free energy of the film-like adhesive according to Examples and Comparative Examples was measured using a contact angle meter (manufactured by Kyowa Interface Science Co., Ltd .: trade name DM-701). Water, methylene iodide and α-bromonaphthalene were used as solvents, and the contact angle between each solvent and the film-like adhesive was measured. The appropriate amount of liquid was 0.5 μL, and the contact angle was determined by the θ / 2 method. Using the obtained contact angle values, the surface free energy was calculated by the surface free energy analysis software FAMAS (trade name, manufactured by Kyowa Interface Science Co., Ltd.). The surface free energy was calculated from the Kitazaki field formula. The surface free energy of the substrate used for the evaluation of the following bleeds was also measured in the same manner. The results are shown in Tables 1 to 3.

<Evaluation of bleed>
First, a structure used for bleed evaluation, which includes a substrate and a chip mounted on the surface thereof, was prepared as follows. That is, the film-like adhesive HR9004-10 (trade name, manufactured by Hitachi Chemical Co., Ltd., thickness 10 μm) was attached to a semiconductor wafer (diameter: 8 inches, thickness: 50 μm) at 70 ° C. A chip with an adhesive was obtained by dicing a semiconductor wafer and a film-like adhesive into a 2.1 × 4.8 mm square. The chip with the adhesive was pressure-bonded to the evaluation substrate at 120 ° C., 0.20 MPa, and 2 seconds. As the evaluation substrate, a substrate (total thickness: 260 μm) coated with solder resist AUS308 (trade name, manufactured by Taiyo Nippon Sanso Co., Ltd.) was used.

On the other hand, the film-like adhesives (thickness 110 μm) according to Examples and Comparative Examples were attached to semiconductor wafers (diameter: 8 inches, thickness 100 μm) at 70 ° C., respectively. A semiconductor device with an adhesive piece was obtained by dicing a semiconductor wafer and a film-like adhesive into a 6 × 12.7 mm square.

A semiconductor element with an adhesive piece was crimped to the position where the chip was mounted in the above structure. The crimping conditions were 120 ° C., 0.20 MPa, and 1.5 seconds. In addition, the position was adjusted so that the chip was embedded in the center position of the film-like adhesive. The evaluation sample thus prepared was observed with a microscope, and the maximum distance (bleed amount) of the resin composition protruding from the end of the semiconductor device was measured. The results are shown in Tables 1 to 3.

According to the present disclosure, there is provided a method for manufacturing a semiconductor device capable of sufficiently suppressing bleeding in a crimping process. Further, according to the present disclosure, a film-like adhesive and a dicing / die bonding integrated film applicable to this manufacturing method are provided.

1 ... Base film, 2 ... Adhesive layer, 8 ... Dicing / die bonding integrated film, 10 ... Substrate, 20 ... First sealing layer (cured product of adhesive piece), 20A ... Adhesive layer (film) Adhesive), 20P ... Adhesive piece, 30 ... Laminate, 50 ... Structure, 100 ... Semiconductor package (semiconductor device), W ... Wafer, Wa ... First semiconductor element (chip), Wb ... Second Semiconductor element

Claims (15)

A step of preparing a film-like adhesive for adhering a semiconductor element and a member on which the semiconductor element is mounted, and
A step of crimping the semiconductor element to the surface in a state where the film-like adhesive and the semiconductor element are laminated on the surface of the member.
Including
The absolute value of the difference between the film-like values of the surface free energy of the adhesive _E 1 (mJ / ^{m 2)} and the value of surface free energy of the element _E ² (mJ / ^m 2) is 6.0 to 10.0 A range of methods for manufacturing semiconductor devices. The semiconductor device is a chip-embedded semiconductor package.
The member is a structure including a substrate and a chip mounted on the surface of the substrate.
The manufacturing method according to claim 1, wherein the semiconductor element is pressure-bonded to the surface of the substrate so that the chip is embedded in the film-like adhesive. The semiconductor device is a wire-embedded semiconductor package.
The member is a structure including a substrate and a wire provided on the surface of the substrate.
The manufacturing method according to claim 1, wherein the semiconductor element is pressure-bonded to the surface of the substrate so that the wire is embedded in the film-like adhesive. A step of preparing a dicing / die bonding integrated film containing the film-like adhesive, the pressure-sensitive adhesive layer, and the base film, which are laminated in this order.
The step of bonding the film-like adhesive of the dicing / die bonding integrated film to the wafer, and
A step of separating the wafer in a state of being bonded to the film-like adhesive into a plurality of semiconductor elements, and
A step of picking up a laminate containing the adhesive piece formed by individualizing the film-like adhesive and the semiconductor element from the pressure-sensitive adhesive layer.
The step of crimping the laminated body to the member and
The process of curing the adhesive piece by heat treatment and
The manufacturing method according to any one of claims 1 to 3. A film-like adhesive made of a thermosetting resin composition.
A film-like adhesive having a surface free energy value E ₁ of 38 to 41 mJ / m ^2. The film-like adhesive according to claim 5, wherein the content of the epoxy resin liquid at 25 ° C. is 5 to 40% by mass based on the total mass of the epoxy resin contained in the thermosetting resin composition. The film-like adhesive according to claim 5 or 6, wherein the thermosetting resin composition contains an epoxy resin having an alicyclic structure, a curing agent, and an elastomer. The film-like adhesive according to claim 7, wherein the content of the epoxy resin having an alicyclic structure is 5 to 30% by mass based on the total mass of the epoxy resin contained in the thermosetting resin composition. The film-like adhesive according to claim 7 or 8, wherein the curing agent is a phenol resin. The film-like adhesive according to any one of claims 7 to 9, wherein the elastomer is an acrylic resin. The film-like adhesive according to any one of claims 5 to 10, wherein the thermosetting resin composition contains an inorganic filler. The film-like adhesive according to any one of claims 5 to 11, wherein the thermosetting resin composition contains a curing accelerator. The film-like adhesive according to any one of claims 5 to 12 and
A base film provided on one surface of the film-like adhesive and
Adhesive film with. A dicing / die bonding integrated film comprising the film-like adhesive according to any one of claims 5 to 12, a pressure-sensitive adhesive layer, and a base film, which are laminated in this order. The dicing / die bonding integrated film according to claim 14, further comprising a protective film provided so as to cover the film-like adhesive.

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