KR20230155344A - Method for producing electrode addition curing resin sheet, electrode addition curing resin sheet, and thermosetting resin sheet - Google Patents

Abstract

The method for producing an electrode addition cured resin sheet of the present invention includes the steps of arranging a plurality of electrodes 20 for electronic components on the temporarily fixed surface 11 of the temporarily fixed base material 10, and the thermosetting resin sheet 30. A process of bonding the first surface 31 to the first surface 11 of the temporarily fixed base material 10 while embedding the plurality of electrodes 20 with the sheet, and thermosetting the resin sheet 30. A process of forming the cured resin sheet 30A, a process of removing the temporarily fixed base material 10 from the cured resin sheet 30A, and grinding the second surface 32 side of the cured resin sheet 30A, It includes a process of exposing the electrode 20 on the second surface 32 side. The resin sheet (X) of the present invention is a thermosetting resin sheet for producing electrode addition-cured resin sheets, and has a tensile storage modulus of 2 GPa or more and 18 GPa or less at 25°C after curing.

Description

Method for producing electrode addition curing resin sheet, electrode addition curing resin sheet, and thermosetting resin sheet

The present invention relates to a method for producing an electrode addition-curing resin sheet, an electrode addition-curing resin sheet, and a thermosetting resin sheet.

In the manufacturing process of an electronic component package such as a semiconductor package, after the electronic component is mounted on a substrate such as a mounting board, a cured resin portion covering the electronic component is formed, and the electronic component is sealed. When an electronic component is mounted face-up with respect to a base material, a terminal of the electronic component on the opposite side to the base material (upper surface side of the electronic component) and a terminal of the base material are electrically connected via a bonding wire. When an electronic component is mounted face-down on a base material, conventionally, a terminal of the electronic component on the base material side and a terminal of the base material are electrically connected through an electrode such as a bump. Technologies related to manufacturing electronic component packages are described, for example, in Patent Document 1 below.

Japanese Patent Publication No. 2001-189415

In the case of the above-mentioned face-up mounting, the cured resin portion that encapsulates the electronic component is formed with a thickness such that the bonding wire extending from the upper surface side of the electronic component is embedded in the cured resin portion together with the electronic component. do. In the case of the above-mentioned face-down mounting, the cured resin portion is formed with a thickness such that the electronic component at the height mounted with respect to the base material with electrodes interposed is embedded in the cured resin portion. Therefore, in the past, there were cases where it was not possible to manufacture an electronic component package sufficiently thin to suit the intended use.

The present invention provides a method for manufacturing an electrode addition-curing resin sheet suitable for manufacturing a thin electronic component package, an electrode addition-curing resin sheet, and a thermosetting resin sheet used for manufacturing the sheet.

The present invention [1] includes a first step of arranging a plurality of electrodes for electronic components on the temporarily fixed surface of a temporarily fixed base material having a temporarily fixed surface, and a first surface and a second surface on the opposite side to the first surface. A second step of bonding the first surface of the thermosetting resin sheet to the temporarily fixing surface of the temporarily fixing base material while embedding the plurality of electrodes for electronic components with the thermosetting resin sheet, and the thermosetting resin sheet. A third step of thermally curing to form a cured resin sheet, a fourth step of removing the temporarily fixed base material from the cured resin sheet, and grinding the second surface side of the cured resin sheet to form a cured resin sheet. A method of manufacturing an electrode-attached mounting board including a fifth step of exposing the electrode for the electronic component.

According to this method, an electrode addition cured resin sheet is produced. This sheet includes a sheet-shaped cured resin portion and a plurality of electrodes for electronic components held in the cured resin portion. Each of the plurality of electrodes has a first electrode surface exposed on one side in the thickness direction of the sheet and a second electrode surface exposed on the other side. A plurality of electrodes are provided at positions according to the type and number of electronic components to be mounted. Such an electrode addition cured resin sheet is suitable for manufacturing thin electronic component packages as follows.

First, electronic components are mounted face-down on one side of the electrode addition cured resin sheet. In this face-down mounting, the surface of the electrode addition-cured resin sheet and the surface of the electronic component are in contact with each other, and the electrode of the sheet and the terminal on the surface of the electronic component are joined one-to-one. Next, the semi-cured resin composition for encapsulation is supplied onto the electrode addition cured resin sheet so as to cover the electronic components. Next, the resin composition for encapsulation that covers the electronic component is cured by heating. As a result, a cured resin portion is formed around the electronic component on the electrode addition cured resin sheet. Afterwards, it is reorganized into electronic component packages as needed. In the electronic component package obtained in this way, the electronic component is sealed by a cured resin portion of the sheet and a cured resin portion formed from the resin composition for sealing in a state in which it can be externally connected through an electrode of the electrode addition cured resin sheet. It is done. Since such an electronic component package is mounted face-down with respect to the substrate while the electronic component is in contact with the substrate, it is suitable for reducing the thickness of the electronic component package compared to the conventional face-up type electronic component package and face-down type electronic component package. That is, the electrode addition cured resin sheet obtained by the manufacturing method of the present invention is suitable for manufacturing thin electronic component packages.

This invention [2] includes the method for producing the electrode addition cured resin sheet described in [1] above, wherein the thermosetting resin sheet has a tensile storage modulus of 2 GPa or more and 18 GPa or less at 25°C after curing.

This configuration is suitable for removing the temporarily fixed base material from the cured resin sheet while suppressing plastic deformation and cracking in the cured resin sheet in the fourth step.

The present invention [3] provides a cured resin sheet having a first surface and a second surface opposite to the first surface, and a plurality of electrodes for electronic components disposed within the cured resin sheet, each comprising: An electrode addition cured resin sheet is provided with a plurality of electrodes for electronic components, each having a first electrode surface exposed to the first surface side and a second electrode surface exposed to the second surface side.

An electrode addition cured resin sheet with such a structure can be manufactured by the above-described manufacturing method and is suitable for manufacturing thin electronic component packages.

This invention [4] is a thermosetting resin sheet for producing an electrode addition cured resin sheet, and includes a thermosetting resin sheet having a tensile storage modulus of 2 GPa or more and 18 GPa or less at 25°C after curing.

Such a thermosetting resin sheet is used to remove a temporarily fixed base material from the cured resin sheet while suppressing plastic deformation and cracking in the cured resin sheet in the fourth step of the method for producing the electrode addition cured resin sheet as described above. suitable for Therefore, this thermosetting resin sheet is suitable for use in the production of an electrode addition curing resin sheet suitable for producing thin electronic component packages.

This invention [5] includes the thermosetting resin sheet described in [4] above, which has a viscosity of 3 kPa·s or more and 100 kPa·s or less at 90°C.

This configuration suppresses the formation of voids between the thermosetting resin sheet and the electrode under temperature conditions of 90°C and its vicinity in the second step of the electrode addition curing resin sheet manufacturing method as described above, while suppressing the formation of voids between the thermosetting resin sheet and the electrode. It is suitable for embedding electrodes.

The present invention [6] has a mass W1 after heat treatment at 150°C for 1 hour and subsequent first standing for 1 hour under conditions of 25°C and 40% relative humidity, and after the first standing, After the second standing for 168 hours under conditions of 85°C and 85% relative humidity, the above [4] has a mass W2 and a moisture absorption rate expressed as [(W2-W1)/W1] x 100 of 0.3% by mass or less. or the thermosetting resin sheet described in [5].

Such a configuration is preferable for ensuring the sealing reliability of the cured resin portion formed from the thermosetting resin sheet.

The present invention [7] includes the thermosetting resin sheet according to any one of the above [4] to [6], which has a relative dielectric constant of 4.2 or less at 10 GHz.

Such a configuration is desirable for reducing transmission loss of high-frequency signals passing through a cured resin portion formed from a thermosetting resin sheet.

[Figure 1] A process of one embodiment of the method for producing an electrode addition cured resin sheet of the present invention. Figure 1A shows the electrode placement process, Figure 1B shows the bonding process, Figure 1C shows the curing process, Figure 1D shows the peeling process, and Figure 1E shows the grinding process.
[Figure 2] is a cross-sectional schematic diagram of one embodiment of the thermosetting resin sheet of the present invention.
[Figure 3] shows an example of a method of using an electrode addition cured resin sheet. FIG. 3A shows a process of mounting an electronic component on an electrode addition curing resin sheet, FIG. 3B shows a process of supplying a thermosetting composition for encapsulating the electronic component, and FIG. 3C shows a process of curing the thermosetting composition.

1A to 1E show steps of one embodiment of the method for producing an electrode addition cured resin sheet of the present invention. This manufacturing method includes an electrode arrangement process as a first process (FIG. 1A), a bonding process as a second process (FIG. 1B), a curing process as a third process (FIG. 1C), and a peeling process as a fourth process (FIG. 1D) and a grinding process as the fifth process (Figure 1E). Specifically, it is as follows.

First, in the electrode placement process, the electrode 20 is placed on the temporarily fixed base material 10, as shown in FIG. 1A. The temporarily fixed base material 10 has a temporarily fixed surface 11 having adhesive force on one side of the thickness direction T.

In this process, specifically, a plurality of electrodes 20 for electronic components (electrodes for electronic components) are disposed on the temporarily fixed surface 11 of the temporarily fixed base material 10.

The temporarily fixed base material 10 includes, for example, a support base material and an adhesive layer that is disposed on the support base material and forms the temporarily fixed surface 11. Examples of the supporting substrate include a resin substrate and a metal substrate. Examples of the resin substrate include flexible plastic films. Examples of plastic films include polyethylene terephthalate film, polyethylene film, polypropylene film, and polyester film. Examples of metal base materials include stainless steel, aluminum, and nickel. The adhesive layer is formed from a pressure-sensitive adhesive. The adhesive layer may be an adhesive layer whose adhesive strength can be reduced later. Examples of such an adhesive layer include an adhesive layer whose adhesive strength can be reduced by curing by ultraviolet irradiation.

The electrode 20 is an electrode of an electronic component such as a semiconductor chip. The electrode 20 has a first part 21 and a second part 22 in this embodiment. In the plane direction perpendicular to the thickness direction T, the first portion 21 is relatively thin, and the second portion 22 is relatively thick. The planar shapes of the first part 21 and the second part 22 may be circular or spherical, such as a square, respectively. The width (maximum length in the surface direction) of the first portion 21 is, for example, 20 to 100 μm. The width (maximum length in the surface direction) of the second part 22 is, for example, 40 to 300 μm as long as it is larger than the width of the first part 21. In this embodiment, the first part 21 side of the electrode 20 is temporarily fixed to the temporarily fixed surface 11. The height (length in the thickness direction T) of the electrode 20 disposed on the temporarily fixing surface 11 is, for example, 20 to 100 μm. In addition, the plurality of electrodes 20 are arranged at intervals from each other in the surface direction on the temporarily fixed surface 11. The spacing between neighboring electrodes 20 is, for example, 100 to 500 μm. The plurality of electrodes 20 are provided at positions corresponding to the type and number of electronic components to be mounted on the electrode addition cured resin sheet X (shown in Fig. 1E) manufactured by this manufacturing method. Examples of materials for the electrode 20 include copper, silver, nickel, and gold.

Next, in the bonding process, as shown in FIG. 1B, the thermosetting resin sheet 30 is bonded to the temporarily fixed base material 10. As shown in FIG. 2, the thermosetting resin sheet 30 used in this process has a first surface 31 and a second surface 32 on the opposite side to the first surface 31, and has a thickness direction. It extends in a direction perpendicular to T. The thermosetting resin sheet 30 contains a thermosetting resin and an inorganic filler, as will be described later. Additionally, the thermosetting resin sheet 30 is in a semi-cured state (state of B stage).

In this process, specifically, while embedding the plurality of electrodes 20 on the temporarily fixed surface 11 of the temporarily fixed base material 10 with the thermosetting resin sheet 30, the first surface of the thermosetting resin sheet 30 ( 31) is joined to the temporary front surface (11). For bonding, a vacuum press machine can be used. Preferably, before bonding, the thermosetting resin sheet 30 is softened by heating. The heating temperature (softening temperature) in this process is, for example, 40°C or higher, and is preferably 60°C or higher. The heating temperature is lower than the curing temperature of the thermosetting resin sheet 30, for example, lower than 100°C, and preferably lower than 90°C.

Next, in the curing step, as shown in FIG. 1C, the thermosetting resin sheet 30 is thermally cured to form the cured resin sheet 30A. The heating temperature (curing temperature) is higher than the softening temperature described above, for example, 100°C or higher, and preferably 120°C or higher. The heating temperature (curing temperature) is, for example, 200°C or lower, preferably 180°C or lower. The heating time is, for example, 10 minutes or more, preferably 30 minutes or more. The heating time is, for example, 180 minutes or less, preferably 120 minutes or less.

Next, in the peeling process, the temporarily fixed base material 10 is removed from the cured resin sheet 30A, as shown in FIG. 1D. When the temporarily fixed surface 11 of the temporarily fixed base material 10 is formed from an adhesive layer whose adhesive strength can be reduced by ultraviolet irradiation, after reducing the adhesive strength of the adhesive layer by ultraviolet irradiation, the cured resin sheet 30A is removed from the cured resin sheet 30A. The temporarily fixed base material (10) is removed. As a result, the first surface 31 of the cured resin sheet 30A, which was in contact with the temporarily fixing surface 11, and the cross section of the first portion 21 of the electrode 20 (the first surface described later) The electrode surface 20a is exposed.

Next, in the grinding process, as shown in FIG. 1E, the second surface side 32 of the cured resin sheet 30A (cured thermosetting resin sheet 30) is ground, and the second surface side 32 is The cross section of the second portion 22 of the electrode 20 (second electrode surface 20b, described later) is exposed. In this process, the electrode 20 may be ground together with the cured resin sheet 30A. For grinding, for example, a back grind device equipped with a grinding wheel is used. The thickness of the cured resin sheet 30A after grinding is, for example, 80 μm or more, and is, for example, 500 μm or less. The ratio of the height of the electrode 20 after grinding to the height of the electrode 20 before grinding (length in the thickness direction T) is, for example, 0.8 to 1.

As described above, the electrode addition cured resin sheet (X) is manufactured. The electrode addition cured resin sheet The cured resin sheet 30A has a first surface 31 and a second surface 32 on the opposite side to the first surface 31, and each electrode disposed and held within the cured resin sheet 30A ( 20) has a first electrode surface 20a exposed to the first surface 31 side and a second electrode surface 20b exposed to the second surface 32 side. The plurality of electrodes 20 are provided at positions corresponding to the type and number of electronic components scheduled to be mounted on the electrode addition cured resin sheet X.

FIG. 3 shows a method of manufacturing a semiconductor package as an example of a method of using the electrode addition cured resin sheet (X).

First, as shown in FIG. 3A, the semiconductor chip 50 is mounted face-down on the second surface (Xb) of the electrode addition cured resin sheet (X). In this embodiment, the semiconductor chip 50 is a semiconductor chip for wireless communication. The operating frequency of the semiconductor chip 50 is, for example, 0.01 to 100 GHz. Additionally, the semiconductor chip 50 has a main surface 51 and a side surface 52. The main surface 51 is provided with a terminal (not shown) for external connection. In the face-down mounting of this process, the second electrode surface 20b of the electrode 20 is in contact with the second surface Xb of the electrode addition-cured resin sheet X and the main surface 51 of the semiconductor chip 50. ) and the terminals on the main surface 51 are joined one to one. Examples of joining methods include ultrasonic joining and soldering joining.

Next, as shown in FIG. 3B, the semi-cured sealing resin composition 60 is supplied onto the electrode addition cured resin sheet X so as to cover the semiconductor chip 50. The resin composition 60 for encapsulation is, for example, a thermosetting resin composition containing a thermosetting resin.

Next, as shown in FIG. 3C, the encapsulating resin composition 60 covering the semiconductor chip 50 is cured by heating and is placed around the semiconductor chip 50 on the electrode addition curing resin sheet A branch 60A is formed. The heating temperature is, for example, 100°C to 200°C.

After this, the electrode addition cured resin sheet In the semiconductor package obtained in this way, the semiconductor chip 50 serves as a cured resin portion of the electrode addition cured resin sheet It is sealed by a cured resin sheet 30A and a cured resin portion 60A formed from the resin composition 60 for sealing. In such a semiconductor package, the semiconductor chip 50 is mounted face-down with respect to the electrode addition-curing resin sheet X in a state in which the semiconductor chip 50 is in contact with the electrode addition-curing resin sheet It is more suitable for thinning than a down-type semiconductor package. That is, the electrode addition cured resin sheet (X) obtained by the manufacturing method of the present invention described above with reference to FIG. 1 is suitable for manufacturing a thin semiconductor package.

The thermosetting resin sheet 30 shown in FIG. 2 is one embodiment of the thermosetting resin sheet of the present invention, and is formed from a thermosetting composition. In this embodiment, the thermosetting composition contains a thermosetting resin and an inorganic filler. Additionally, the thermosetting resin sheet 30 is in a semi-cured state (state of B stage).

Examples of thermosetting resins include epoxy resins, silicone resins, urethane resins, polyimide resins, urea resins, melamine resins, and unsaturated polyester resins. These thermosetting resins may be used individually, or two or more types may be used together. The content ratio of the thermosetting resin in the thermosetting composition is preferably 3% by mass or more, more preferably 3.5% by mass or more. The content ratio of the thermosetting resin in the thermosetting composition is preferably 35 mass% or less, more preferably 30 mass% or less.

The thermosetting resin preferably includes an epoxy resin. Examples of epoxy resins include bifunctional epoxy resins and trifunctional or higher multifunctional epoxy resins. Examples of the bifunctional epoxy resin include bisphenol A-type epoxy resin, bisphenol F-type epoxy resin, modified bisphenol A-type epoxy resin, modified bisphenol F-type epoxy resin, and biphenyl-type epoxy resin. Examples of trifunctional or higher multifunctional epoxy resins include phenol novolak-type epoxy resins, cresol novolak-type epoxy resins, trishydroxyphenylmethane-type epoxy resins, tetraphenylolethane-type epoxy resins, and dicyclopentadiene. N-type epoxy resin can be mentioned. These epoxy resins may be used individually, or two or more types may be used together. As the epoxy resin, bifunctional epoxy resin and/or the above-mentioned multifunctional epoxy resin are preferably used, and bisphenol F-type epoxy is more preferably used.

The epoxy equivalent of the epoxy resin is preferably 10 g/eq or more, more preferably 50 g/eq or more, and even more preferably 100 g/eq or more. The epoxy equivalent weight of the epoxy resin is preferably 500 g/eq or less, more preferably 450 g/eq or less, and even more preferably 400 g/eq or less. When the thermosetting resin contains multiple epoxy resins, the epoxy equivalent is the weighted average epoxy equivalent of the multiple epoxy resins.

When an epoxy resin is used, the thermosetting resin preferably contains a phenol resin as a curing agent for the epoxy resin. This configuration is suitable for the thermosetting resin sheet 30 to exhibit high heat resistance and high chemical resistance after curing, and is therefore suitable for forming a cured resin portion with excellent sealing reliability from the thermosetting resin sheet 30. As the phenol resin, a novolak-type phenol resin and/or triphenylmethane-type epoxy resin is preferably used. Examples of the novolak-type phenolic resin include phenol novolak resin, phenol aralkyl resin, trishydroxyphenylmethane novolak resin, cresol novolak resin, tert-butylphenol novolak resin, and nonylphenol novolak resin. can be mentioned. Examples of the triphenylmethane type epoxy resin include trishydroxyphenylmethane type epoxy resin. These phenol resins may be used individually, or two or more types may be used together.

In the thermosetting composition, the amount of hydroxyl groups in the phenol resin relative to 1 equivalent of the epoxy group of the epoxy resin is preferably 0.7 equivalent or more, more preferably 0.9 equivalent or more. In the thermosetting composition, the amount of hydroxyl groups in the phenol resin relative to 1 equivalent of the epoxy group of the epoxy resin is preferably 1.5 equivalents or less, more preferably 1.2 equivalents or less. Moreover, the compounding amount of the phenol resin with respect to 100 parts by mass of the epoxy resin is preferably 20 parts by mass or more, more preferably 30 parts by mass or more. The amount of the phenol resin as a curing agent per 100 parts by mass of the epoxy resin is preferably 80 parts by mass or less, more preferably 70 parts by mass or less.

Examples of the inorganic filler include inorganic particles having a solid structure (solid inorganic particles) and inorganic particles having a hollow structure (hollow inorganic particles).

Examples of solid inorganic particles include silica, calcium oxide, magnesium oxide, titanium oxide, aluminum oxide, zirconium oxide, cesium oxide, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, aluminum nitride, boron nitride, and nitride. Silicon, and silicon carbide can be mentioned. Solid inorganic particles may be used individually, or two or more types may be used together. As solid inorganic particles, solid silica filler is preferably used.

The average particle diameter of the solid inorganic particles is preferably 0.1 μm or more, more preferably 0.5 μm or more. The average particle diameter is preferably 20 μm or less, more preferably 10 μm or less. These structures are preferable for ensuring good viscosity and electrode shape followability in the thermosetting resin sheet 30 in the above-described bonding process (FIG. 1B). The average particle diameter of solid inorganic particles is the median diameter (particle size at which the volume cumulative frequency reaches 50% from the small diameter side) in the volume-based particle size distribution, and is based on the particle size distribution obtained by, for example, laser diffraction/scattering methods. (The same applies to the average particle diameter of other inorganic fillers).

The content ratio of solid inorganic particles in the thermosetting composition is preferably 60% by mass or more, more preferably 70% by mass or more, and even more preferably 80% by mass or more. This configuration is suitable for suppressing expansion and contraction of the thermosetting resin sheet 30 due to temperature changes. The copper content ratio is preferably 90% by mass or less, more preferably 85% by mass or less. This configuration is suitable for ensuring fluidity of the thermosetting resin sheet 30 in the above-described bonding process (FIG. 1B).

Materials for solid inorganic particles also include layered silicate compounds. The particles of the layered silicate compound in the thermosetting composition are a component that thickens the thermosetting composition while expressing thixotropic properties in the thermosetting composition. Examples of layered silicate compounds include smectite, kaolinite, halloysite, talc, and mica. Examples of smectite include montmorillonite, beidellite, nontronite, saponite, hectorite, soconite, and stevensite. As the layered silicate compound, smectite is preferably used because it is easy to mix with a thermosetting resin, and montmorillonite is more preferably used.

The layered silicate compound may be an unmodified product whose surface is not modified, or may be a modified product whose surface is modified by an organic component. For example, from the viewpoint of compatibility with the first thermosetting resin, a layered silicate compound whose surface is modified with an organic component is preferably used, and more preferably, an organic smectite whose surface is modified with an organic component is used. , more preferably, organic bentonite whose surface is modified with organic components is used.

Examples of organic components include organic cations (onium ions) such as ammonium, imidazolium, pyridinium, and phosphonium. Examples of ammonium include dimethyl distearylammonium, distearylammonium, octadecylammonium, hexyl ammonium, octylammonium, 2-hexylammonium, dodecylammonium, and trioctylammonium. Examples of imidazolium include methylstearylimidazolium, distearylimidazolium, methylhexylimidazolium, dihexylimidazolium, methyloctylimidazolium, dioctylimidazolium, and methyldodecyl. Examples include imidazolium and didodecylimidazolium. Examples of pyridinium include stearylpyridinium, hexylpyridinium, octylpyridinium, and dodecylpyridinium. As phosphonium, for example, dimethyldistearylphosphonium, distearylphosphonium, octadecylphosphonium, hexylphosphonium, octylphosphonium, 2-hexylphosphonium, dodecylphosphonium, and trioctylphosphonium. Phonium can be mentioned. Organic cations may be used individually, or two or more types may be used together. As the organic cation, ammonium is preferably used, and dimethyldistearylammonium is more preferably used.

As the organic layered silicate compound, preferably, organic smectite whose surface is modified with ammonium is used, and more preferably, organic bentonite whose surface is modified with dimethyldistearylammonium is used.

The average particle diameter of the layered silicate compound is preferably 1 nm or more, more preferably 5 nm or more, and even more preferably 10 nm or more. The average particle diameter of the layered silicate compound is preferably 100 μm or less, more preferably 50 μm or less, and still more preferably 10 μm or less.

The content rate of the layered silicate compound in the thermosetting composition is preferably 1% by mass or more, more preferably 1.2% by mass or more, and even more preferably 1.4% by mass or more. This configuration is suitable for thickening the thermosetting composition and developing thixotropic properties in the thermosetting composition, where the viscosity becomes lower when subjected to pressing force compared to when not applied. Such thixotropic properties are desirable for ensuring good electrode shape followability in the thermosetting resin sheet 30 in the above-described bonding process (FIG. 1B). From the viewpoint of avoiding excessive thickening of the thermosetting composition, the content rate of the layered silicate compound in the thermosetting composition is preferably 6% by mass or less, more preferably 5% by mass or less, and even more preferably 4% by mass or less.

As the hollow inorganic particles, a hollow ceramic filler is preferably used. A hollow ceramic filler is a hollow filler made of fired inorganic material. Examples of materials for hollow ceramic fillers include oxide ceramics, nitride ceramics, carbide ceramics, and glass ceramics. Examples of oxide ceramics include titanium oxide, aluminum oxide, zirconium oxide, and cesium oxide. Examples of nitride ceramics include silicon nitride, titanium nitride, and aluminum nitride. Examples of carbide ceramics include silicon carbide, titanium carbide, and tungsten carbide. Examples of glass ceramics include aluminoborosilicate glass, aluminoborosilicate glass, lead borosilicate glass, and zinc borosilicate glass. As the hollow ceramic filler, glass ceramics are preferably used, and aluminoborosilicate glass is more preferably used.

The average particle diameter of the hollow ceramic filler is preferably 0.1 μm or more, more preferably 0.5 μm or more. The average particle diameter is preferably 30 μm or less, more preferably 20 μm or less, and even more preferably 10 μm or less.

The particle density of the hollow ceramic filler is preferably 0.3 g/cm ³ or more, more preferably 0.5 g/cm ³ or more, and preferably 0.9 g/cm ³ or less, more preferably 0.8 g/cm 3 or less. It is ³ or less. This configuration is desirable for lowering the dielectric constant of the above-described cured resin sheet 30A (cured resin portion) formed from the thermosetting resin sheet 30, and therefore, passes through the cured resin portion in the above-described semiconductor package. This is desirable for reducing transmission loss of high-frequency signals.

The content ratio of the hollow ceramic filler in the thermosetting composition is preferably 15 volume% or more, more preferably 50 volume% or more, even more preferably 60 volume% or more, from the viewpoint of reducing transmission loss described above. Preferably it is 65 volume% or more, especially preferably 70 volume% or more, and especially preferably 75 volume% or more. From the viewpoint of reducing transmission loss described above, the proportion of hollow ceramic filler in the inorganic filler is preferably 20 volume% or more, more preferably 50 volume% or more, further preferably 80 volume% or more, especially preferably is 100 volume%. Additionally, the content ratio of the hollow ceramic filler in the thermosetting composition is preferably 85 volume% or less, more preferably 82 volume% or less, and even more preferably 80 volume% or less. The content ratio of the hollow ceramic filler in the thermosetting composition is preferably 90% by mass or less, more preferably 85% by mass or less. This configuration is suitable for ensuring fluidity of the thermosetting resin sheet 30 in the above-described bonding process (FIG. 1B).

The content rate of the inorganic filler in the thermosetting composition is preferably 60% by mass or more, more preferably 70% by mass or more, and even more preferably 80% by mass or more. This configuration is suitable for suppressing expansion and contraction of the thermosetting resin sheet 30 due to temperature changes. The copper content ratio is preferably 90% by mass or less, more preferably 85% by mass or less. This configuration is suitable for ensuring fluidity of the thermosetting resin sheet 30 in the above-described bonding process (FIG. 1B).

The thermosetting composition may contain other components. Other components include, for example, a curing accelerator, a thermoplastic resin, a pigment, and a silane coupling agent.

A curing accelerator is a catalyst (thermal curing catalyst) that promotes curing of a thermosetting resin by heating. Examples of the curing accelerator include imidazole compounds and organic phosphorus compounds. Examples of the imidazole compound include 2-phenyl-4,5-dihydroxymethylimidazole and 2-phenyl-4-methyl-5-hydroxymethylimidazole. Examples of organic phosphorus compounds include triphenylphosphine, tricyclohexylphosphine, tributylphosphine, and methyldiphenylphosphine. As a curing accelerator, an imidazole compound is preferably used, and 2-phenyl-4,5-dihydroxymethylimidazole is more preferably used. The compounding amount of the curing accelerator with respect to 100 parts by mass of the thermosetting resin is, for example, 0.05 parts by mass or more, and is, for example, 5 parts by mass or less.

Thermoplastic resins include, for example, acrylic resin, natural rubber, butyl rubber, isoprene rubber, chloroprene rubber, ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ethylene-acrylic acid ester copolymer, polybutadiene resin, Polycarbonate resin, thermoplastic polyimide resin, polyamide resin, phenoxy resin, saturated polyester resin (PET, etc.), polyamideimide resin, fluororesin, and styrene-isobutylene-styrene block copolymer. there is. These thermoplastic resins may be used individually, or two or more types may be used together.

As the thermoplastic resin, an acrylic resin is preferably used from the viewpoint of ensuring compatibility between the thermosetting resin and the thermoplastic resin. Examples of the acrylic resin include (meth)acrylic polymer as a polymerization product of a monomer component containing a (meth)acrylic acid alkyl ester having a linear or branched alkyl group and other monomers (copolymerizable monomers).

The glass transition temperature (Tg) of the thermoplastic resin is preferably -70°C or higher. The glass transition temperature is preferably 0°C or lower, more preferably -5°C or lower. Regarding the glass transition temperature (Tg) of the polymer, the glass transition temperature (theoretical value) determined based on Fox's equation below can be used. Fox's equation is a relationship between the glass transition temperature Tg of the polymer and the glass transition temperature Tgi of the homopolymer monomer constituting the polymer. In the formula of Fox below, Tg represents the glass transition temperature (°C) of the polymer, Wi represents the weight fraction of monomer i constituting the polymer, and Tgi represents the glass transition temperature of the homopolymer formed from monomer i. (°C). Literature values for the glass transition temperature of homopolymers can be used, for example, “Polymer Handbook” (4th edition, John Wiley & Sons, Inc., 1999) and “New Polymer Book 7 Introduction to Synthetic Resins for Paints.” (Kyozo Kitaoka, Polymer Publishing Society, 1995) contains the glass transition temperatures of various homopolymers. On the other hand, the glass transition temperature of the monomer homopolymer can also be determined by the method specifically described in Japanese Patent Application Laid-Open No. 2007-51271.

Fox's equation 1/(273＋Tg)=Σ［Wi/(273＋Tgi)］

The weight average molecular weight of the thermoplastic resin is preferably 100,000 or more, preferably 300,000 or more. The weight average molecular weight of the thermoplastic resin is preferably 2 million or less, more preferably 1 million or less. The weight average molecular weight of the resin is measured based on standard polystyrene conversion values by gel permeation chromatography (GPC).

The content ratio of the thermoplastic resin in the thermosetting composition is preferably 1% by mass or more, more preferably 2% by mass or more. The copper content ratio is preferably 80 mass% or less, more preferably 60 mass% or less.

Examples of the pigment include black pigments such as carbon black. The particle diameter of the pigment is, for example, 0.001 μm or more and, for example, is 1 μm or less. The particle size of the pigment is the arithmetic mean diameter determined by observing the pigment with an electron microscope. In addition, the content ratio of the pigment in the thermosetting composition is, for example, 0.1% by mass or more, and is, for example, 2% by mass or less.

Examples of the silane coupling agent include a silane coupling agent containing an epoxy group. Examples of epoxy group-containing silane coupling agents include 3-glycidoxydialkyl dialkoxysilane and 3-glycidoxyalkyl trialkoxysilane. Examples of 3-glycidoxy dialkyl dialkoxysilane include 3-glycidoxypropylmethyldimethoxysilane and 3-glycidoxypropylmethyldiethoxysilane. Examples of 3-glycidoxyalkyl trialkoxysilane include 3-glycidoxypropyltrimethoxysilane and 3-glycidoxypropyltriethoxysilane. As a silane coupling agent, 3-glycidoxyalkyltrialkoxysilane is preferably used, and 3-glycidoxypropyltrimethoxysilane is more preferably used. The content ratio of the silane coupling agent in the thermosetting composition is preferably 0.1 mass% or more, more preferably 1 mass% or more. The copper content ratio is preferably 10 mass% or less, more preferably 5 mass% or less.

The thermosetting resin sheet 30 can be manufactured, for example, as follows.

First, each component mentioned above for the thermosetting composition and the solvent are mixed to prepare a varnish of the thermosetting composition. Examples of solvents include methyl ethyl ketone, ethyl acetate, and toluene. Next, the varnish is applied on a base material such as a release film to form a coating film, and then the coating film is dried by heating. As a result, a composition film of a predetermined thickness in a semi-cured state can be formed as the thermosetting resin sheet 30 (in FIG. 2, the thermosetting resin sheet 30 is disposed on the peeling film L indicated by a virtual line, there is). Examples of the release film include flexible plastic films. Examples of the plastic film include polyethylene terephthalate film, polyethylene film, polypropylene film, and polyester film. The thickness of the peeling film is, for example, 3 μm or more, and is, for example, 200 μm or less. The surface of the release film is preferably subjected to a mold release treatment.

When manufacturing the thick thermosetting resin sheet 30, a plurality of composition films may be bonded and integrated under heating conditions. The heating temperature is, for example, 70°C to 90°C.

As described above, the thermosetting resin sheet 30 of a predetermined thickness can be produced. The thickness of the thermosetting resin sheet 30 is, for example, 10 μm or more, preferably 25 μm or more, and more preferably 30 μm or more. The thickness of the thermosetting resin sheet 30 is, for example, 3000 μm or less, preferably 1000 μm or less, more preferably 500 μm or less, further preferably 300 μm or less, particularly preferably 100 μm or less.

The thermosetting resin sheet 30 has a tensile storage modulus of 2GPa or more and 18GPa or less at 25°C after curing by heating at 150°C for 1 hour. This configuration is used to remove the temporarily fixed base material 10 from the cured resin sheet 30A while suppressing plastic deformation and cracking in the cured resin sheet 30A in the above-described peeling process (FIG. 1D). Suitable. Such thermosetting resin sheet 30 is suitable for use in manufacturing the electrode addition curing resin sheet (X) described above. From the viewpoint of suppressing plastic deformation and cracking, the storage modulus of the thermosetting resin sheet 30 is preferably 5 GPa or more, more preferably 7 GPa or more, and preferably 16 GPa or less, more preferably 12 GPa. It is as follows. The tensile storage modulus can be measured by the method described later in Examples.

The thermosetting resin sheet 30 has a viscosity of 3 kPa·s or more and 100 kPa·s or less at 90°C. This configuration suppresses the formation of voids between the thermosetting resin sheet 30 and the electrode 20 under temperature conditions of 90° C. and its vicinity in the above-described peeling process (FIG. 1B), while suppressing the formation of voids between the thermosetting resin sheet 30 and the electrode 20. It is suitable for embedding the electrode 20 by (30). From the viewpoint of such embedding properties, the viscosity of the thermosetting resin sheet 30 at 90°C is preferably 5 kPa·s or more, more preferably 6 kPa·s or more, and also 90 kPa·s or less and 80 kPa·s. It is as follows. The viscosity at 90°C can be determined by the measurement method described later in the Examples.

The thermosetting resin sheet 30 has a mass W1 after heat treatment at 150°C for 1 hour and subsequent first standing for 1 hour under conditions of 25°C and 40% relative humidity. The thermosetting resin sheet 30 has a mass W2 after the first standing and the second standing for 168 hours under conditions of 85°C and 85% relative humidity. And the thermosetting resin sheet 30 has a moisture absorption rate expressed as [(W2-W1)/W1] x 100, preferably 0.3 mass% or less, more preferably 0.2 mass% or less. Such a configuration is preferable for ensuring sealing reliability of the cured resin portion formed from the thermosetting resin sheet 30.

After the thermosetting resin sheet 30 is cured by heating at 150°C for 1 hour, the relative dielectric constant at 10 GHz is preferably 4.2 or less, more preferably 4.0 or less, and still more preferably 3.0 or less. This configuration is desirable for reducing transmission loss of high-frequency signals passing through the cured resin portion formed from the thermosetting resin sheet 30. The relative dielectric constant is, for example, 1 or more. The relative dielectric constant can be measured by the method described later in the Examples.

Example

The present invention will be described in more detail below by way of examples. The present invention is not limited to the examples. In addition, the specific values of the mixing amount (content), physical properties, parameters, etc. used in the following description are the corresponding mixing amounts (content), physical properties, etc. described in the "Specific Details for Carrying out the Invention" above. , parameters, etc., can be replaced with the upper limit (a numerical value defined as “less than” or “less than”) or a lower limit (a numerical value defined as “more than” or “more than”) of the corresponding description.

[Examples 1 to 4 and Comparative Examples 1 and 2]

Each component was mixed according to the formulation shown in Table 1 to prepare a varnish of the composition (in Table 1, the unit of each numerical value representing the composition is a relative "part by mass"). Next, varnish was applied to a polyethylene terephthalate film (PET film) whose surface had been treated with silicone release treatment to form a coating film. Next, this coating film was dried by heating at 120°C for 2 minutes to produce a composition film with a thickness of 65 μm on a PET film (the formed composition film is in the B stage). Next, four composition films were bonded at 80°C to produce a thermosetting resin sheet with a thickness of 260 μm (the formed thermosetting resin sheet is in the B stage).

<Viscosity of thermosetting resin sheet>

For each thermosetting resin sheet of Examples 1 to 4 and Comparative Examples 1 and 2, the viscosity at 90°C was measured. In this measurement, a rheometer (brand name "HAAKE MARS III", manufactured by Thermo Fisher Scientific) is used, and a heating plate in the device and a parallel plate (diameter 8 mm) arranged in parallel with the heat plate are used. A sample collected from the thermosetting resin sheet was sandwiched between the plates, and the gap between the plates was set to 1 mm. Then, the viscosity was measured under the conditions of a frequency of 1 Hz, a strain value of 0.005%, a measurement temperature range of 50°C to 90°C, and a temperature increase rate of 30°C/min. The viscosity (kPa·s) at 90°C is shown in Table 1.

〈Tensile storage modulus〉

For each thermosetting resin sheet of Examples 1 to 4 and Comparative Examples 1 and 2, the tensile storage modulus after curing was measured as follows. First, the thermosetting resin sheet was cured by heating at 150°C for 1 hour. Next, a sample piece (3 mm wide x 40 mm long x 260 μm thick) for measurement was cut out from the cured thermosetting resin sheet. Next, the tensile storage modulus was measured in a temperature range of -10°C to 260°C using a dynamic viscoelasticity measuring device (brand name "RSA-G2", manufactured by TA Instruments). In this measurement, the initial chuck distance of the chuck for holding the sample piece was set to 22.5 mm, the measurement mode was set to tensile mode, the temperature increase rate was set to 10°C/min, the frequency was set to 1 Hz, and the dynamic strain was set to 0.05%. . The tensile storage modulus (GPa) at 25°C is shown in Table 1.

〈Moisture absorption rate〉

For each thermosetting resin sheet of Examples 1 to 4 and Comparative Examples 1 and 2, the moisture absorption rate was investigated as follows. First, the thermosetting resin sheet was cured by heating at 150°C for 1 hour. Next, a sample piece (50 mm wide x 50 mm long x 260 μm thick) for measurement was cut out from the cured thermosetting resin sheet. Next, the sample piece was left to stand for 1 hour under conditions of 25°C and 40% relative humidity. Next, the mass (mass W1) of the sample piece was measured. Next, the sample piece was left to stand for 168 hours under conditions of 85°C and 85% relative humidity. Next, the mass (mass W2) of the sample piece was measured. Then, the moisture absorption rate expressed by the following formula was calculated. The values (%) are shown in Table 1.

Moisture absorption rate (%) = [(W2-W1)/W1] × 100

〈Relative permittivity〉

For each thermosetting resin sheet of Examples 1 to 4 and Comparative Examples 1 and 2, the relative dielectric constant at 10 GHz after curing was measured as follows. First, the thermosetting resin sheet was cured by heating at 150°C for 1 hour. Next, a sample piece (30 mm wide x 30 mm long x 260 μm thick) for measurement was cut out from the cured thermosetting resin sheet. Next, the relative dielectric constant of the sample piece at 10 GHz was measured using a PNA network analyzer (manufactured by Agilent Technologies) and a SPDR (Split post dielectric resonator) resonator.

The measurement results are shown in Table 1.

<Evaluation of bending>

For each thermosetting resin sheet of Examples 1 to 4 and Comparative Examples 1 and 2, the degree of warpage after curing was investigated. Specifically, first, a laminate sample comprising a 42 alloy plate with a size of 90 mm x 90 mm x 150 μm in thickness and a thermosetting resin sheet bonded to the entire thickness direction of the 42 alloy plate was subjected to It was heated for a time and then left standing at 25°C for 1 hour. Then, the maximum value of the distance between the mounting surface on which the laminate sample was placed with the 42 alloy plate of the laminate sample facing downward and the edge edge of the laminate sample was measured as the amount of deflection (mm). The results are shown in Table 1.

〈Deformation/crack resistance〉

Each thermosetting resin sheet of Examples 1 to 4 and Comparative Examples 1 and 2 was examined for the presence or absence of deformation and cracking in the process of producing the electrode addition curing resin sheet. Specifically, first, a thermosetting resin sheet was bonded to the temporarily fixed surface of a temporarily fixed base material on which a plurality of electrodes were disposed on the temporarily fixed surface, while embedding the plurality of electrodes with a thermosetting resin sheet (FIG. 1B). The temporarily fixed base material is a SUS base material with a thickness of 100 μm. The electrode is made of copper and has a cylindrical first part (height 30 μm) and a cylindrical second part (height 20 μm) with a larger diameter. The distance between neighboring electrodes was about 100 to 150 μm. In addition, for bonding, a vacuum press machine (product name "Vacuum Pressure Apparatus VS008-1515", manufactured by Mikado Tecnos) was used. In bonding, sealing was performed at a vacuum degree of 2000 Pa or less under the conditions of a temperature of 90°C, a press pressure of 0.1 MPa, and a press time of 40 seconds to obtain a bonded body. Next, the assembly (temporarily fixed base material, electrode, thermosetting resin sheet) was heated at 150°C for 1 hour (Figure 1C). In this way, the thermosetting resin sheet was cured to form a cured resin sheet holding the electrode. Next, the bonded body was left standing at 25°C for 1 hour. Next, for the assembled body, the temporarily fixed base material was peeled from the electrode addition cured resin sheet (Figure 1D). In peeling, the peeling angle was set to 90° to 145°, and the peeling speed was set to about 300 mm/sec. After that, the presence or absence of deformation and the presence or absence of cracks were confirmed through visual observation of the electrode addition cured resin sheet. Regarding the deformation and cracking resistance of the thermosetting resin sheet after curing, cases where neither deformation nor cracking occurred were evaluated as "good", and cases where deformation and/or cracking occurred were evaluated as "poor." The results are shown in Table 1.

〈Equipment of electrodes〉

For each of the thermosetting resin sheets of Examples 1 to 4 and Comparative Examples 1 and 2, the embedding properties of the electrodes in the process of producing the electrode addition curing resin sheet were investigated. Specifically, first, the electrode addition cured resin sheet used for the above-described evaluation of deformation and crack resistance was cut in the thickness direction, and the cross sections of the predetermined electrode and the cured resin portion around the electrode were cut out. . Next, the cross section was observed using an optical microscope. Regarding the embedding of the electrode in the thermosetting resin sheet after curing, the case where no gap was formed between the electrode and the cured resin portion was evaluated as "good", and the case where a void was formed was evaluated as "poor." The results are shown in Table 1.

Each component used in the examples and comparative examples is as follows.

First epoxy resin: “YSLV-80XY” manufactured by Nippon Chemical Co., Ltd. (bisphenol F-type epoxy resin, high molecular weight epoxy resin, epoxy equivalent weight 191 g/eq, solid at room temperature, softening point 80°C)

Second epoxy resin: “EPPN-501HY” manufactured by Nippon Kayaku Co., Ltd. (multifunctional epoxy resin, epoxy equivalent weight 169 g/eq, solid at room temperature, softening point 60°C)

First phenol resin: “LVR-8210DL” manufactured by Kunei Chemical Co., Ltd. (novolak-type phenol resin, latent hardener, hydroxyl equivalent weight 104 g/eq, solid at room temperature, softening point 60°C)

Second phenol resin: “TPM-100” manufactured by Kunei Chemical Co., Ltd. (triphenylmethane type phenol resin, latent hardener, hydroxyl equivalent weight 98 g/eq, solid at room temperature, softening point 108.2°C)

Acrylic resin (acrylic polymer): "HME-2006M" manufactured by Negami Industries (carboxyl group-containing acrylic resin, acid value 32 mgKOH/g, weight average molecular weight 1.29 million, glass transition temperature (Tg) -13.9°C, solid content concentration 20 mass % methyl ethyl ketone solution)

First silica filler: “FB-8SM” manufactured by Denka Co., Ltd. (spherical silica particles, average particle diameter 7.0 μm, no surface treatment)

Second silica filler: “SC220G-SMJ” (spherical silica particles, average particle size 0.5 μm) manufactured by Admatex Co., Ltd. with 3-methacryloxypropyltrimethoxysilane (“KBM-503” manufactured by Shin-Etsu Chemical Co., Ltd.) Surface treated (silane coupling agent used for surface treatment is 1 part by mass per 100 parts by mass of silica particles)

Hollow ceramic filler: “Cells Spears” manufactured by Taiheyo Cement Co., Ltd. (aluminoborosilicate glass, spherical particles with hollow structure, average particle diameter 4.0 μm, particle density 0.6 g/cm ³ )

Layered silicate compound: “Esben NX” manufactured by Hojun Co., Ltd. (Organized bentonite whose surface is modified with dimethyldistearylammonium)

Curing accelerator: “2PHZ-PW” (2-phenyl-4,5-dihydroxymethylimidazole) manufactured by Shikoku Chemical Industry Co., Ltd.

Silane coupling agent: “KBM-403” (3-glycidoxypropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd.

Pigment: “Carbon Black #20” manufactured by Mitsubishi Chemical Corporation (average particle diameter 50 nm)

Solvent: Methyl Ethyl Ketone (MEK)

The present invention relates to a method for producing an electrode addition-curing resin sheet, an electrode addition-curing resin sheet, and a thermosetting resin sheet.

The above-described embodiments are examples of the present invention, and the present invention should not be construed as limited by the embodiments. Modifications of the present invention apparent to those skilled in the art are included in the following claims.

The manufacturing method of the electrode addition-curing resin sheet, the electrode addition-curing resin sheet, and the thermosetting resin sheet of the present invention can be used for manufacturing electronic component packages such as semiconductor packages.

X electrode addition curing resin sheet
T thickness direction
10 Temporarily fixed equipment
11 Gagojeong-myeon
20 Electrodes (electrodes for electronic components)
20a first electrode surface
20b second electrode surface
21 Part 1
22 Part 2
30 thermosetting resin sheet
31 page 1
32 Page 2
30A cured resin sheet

Claims (7)

A first step of arranging a plurality of electrodes for electronic components on the temporarily fixed surface of a temporarily fixed base material having a temporarily fixed surface;
The above-mentioned first surface of a thermosetting resin sheet having a first surface and a second surface opposite to the first surface is embedded with the plurality of electronic component electrodes in the above-mentioned temporarily fixed base material. A second step of bonding to the temporary fixing surface,
A third step of thermosetting the thermosetting resin sheet to form a cured resin sheet,
A fourth step of removing the temporarily fixed base material from the cured resin sheet,
A method for manufacturing an electrode addition cured resin sheet, including a fifth step of grinding the second surface side of the cured resin sheet and exposing the electrode for electronic components on the second surface side. According to claim 1,
A method for producing an electrode addition cured resin sheet, wherein the thermosetting resin sheet has a tensile storage modulus of 2 GPa or more and 18 GPa or less at 25°C after curing. A cured resin sheet having a first surface and a second surface opposite to the first surface;
A plurality of electrodes for electronic components disposed in the cured resin sheet, each having a first electrode surface exposed to the first surface side and a second electrode surface exposed to the second surface side. An electrode addition cured resin sheet including electrodes. A thermosetting resin sheet for manufacturing electrode addition curing resin sheets,
A thermosetting resin sheet that, after curing, has a tensile storage modulus of 2 GPa or more and 18 GPa or less at 25°C. According to claim 4,
A thermosetting resin sheet having a viscosity of 3 kPa·s or more and 100 kPa·s or less at 90°C. The method of claim 4 or 5,
After heat treatment at 150°C for 1 hour and subsequent first standing for 1 hour under conditions of 25°C and 40% relative humidity, it has a mass W1,
After the first standing, after the second standing for 168 hours under conditions of 85°C and 85% relative humidity, it has a mass W2,
[(W2-W1)/W1] A thermosetting resin sheet with a moisture absorption rate of 0.3% by mass or less, expressed as ×100. According to any one of claims 4 to 6,
A thermosetting resin sheet having a relative dielectric constant of 4.2 or less at 10 GHz.

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