CN115910936A - Sealing resin sheet and electronic component device - Google Patents

Abstract

The invention provides a sealing resin sheet and an electronic component device, wherein the sealing resin sheet is used for sealing an electronic component chip which is installed on a substrate in a state of facing the substrate through a gap, and is suitable for simultaneously achieving high heat dissipation performance and good hollow sealing performance. A sealing resin sheet (X) of the present invention is provided with a sealing resin layer (11) and a sealing resin layer (12) in this order in the thickness direction (H). The sealing resin layer (11) contains a 1 st thermosetting resin, a layered silicate compound, and a 1 st inorganic filler other than the layered silicate compound. The sealing resin layer (12) contains a No. 2 thermosetting resin and a No. 2 inorganic filler. The sealing resin sheet (X) has a thermal conductivity of 2W/m.K or more after curing. An electronic component device (Y) of the present invention is provided with a substrate (S), an electronic component chip (21) mounted on the substrate (S), and a cured resin section (10) formed from a sealing resin sheet (X).

Description

Sealing resin sheet and electronic component device

Technical Field

The present invention relates to a sealing resin sheet and an electronic component device.

Background

Conventionally, a sealing resin sheet for sealing an electronic component chip on a mounting board is known. The sealing resin sheet is a sheet-like sealing resin material containing a thermosetting resin.

On the other hand, as an electronic component chip, an electronic component chip mounted on a mounting substrate in a state of facing the substrate with a gap therebetween is known. Such an electronic component chip is sealed with a sealing resin sheet as follows, for example.

First, a sealing resin sheet having a predetermined thickness is pressed against a plurality of electronic component chips (facing a substrate via a gap) which are bonded to the same surface of a mounting substrate and spaced from each other by a flat press (pressing step). Thereby, the sealing resin sheet is heated and softened, and is plastically deformed, thereby covering the electronic component chips. Next, the sealing resin sheet covering the electronic component chip is cured by heating at a high temperature (curing step). Thereby, a cured resin portion is formed around each electronic component chip on the substrate, and each electronic component chip is sealed. Thereafter, the cured resin portion is cut together with the substrate by, for example, dicing with a blade, to obtain an electronic component device as a singulated electronic component package (singulation step). Such a sealing technique for an electronic component chip is described in patent document 1 below, for example.

Documents of the prior art

Patent document

[ patent document 1] Japanese patent application laid-open No. 2011-219726

Disclosure of Invention

Problems to be solved by the invention

In the sealing resin sheet, it is required that the side (1 st side) in contact with the electronic component chip be deformed to follow the outer shape of the chip while sufficiently fluidizing in the heat-softened state in the pressing step. This is because the cured resin portion that appropriately covers the electronic component chip is formed of the sealing resin sheet. In addition, the side (2 nd side) of the sealing resin sheet opposite to the 1 st side is required to be sufficiently fluidized in the heat-softened state in the pressing step and the curing step to flatten the exposed surface. This is to realize appropriate laser marking on the exposed surface in a subsequent step. In addition, the 1 st side of the sealing resin sheet is required to prevent the thermosetting resin temporarily softened by high-temperature heating from entering too much into the gap between the mounting board and the electronic component chip in the curing step. This is to achieve sealing (hollow sealing) of the electronic component chip on the substrate while securing a gap between the mounting substrate and the electronic component chip. As described above, the sealing resin sheet requires different properties with respect to fluidity when heated and softened, depending on the stage in the electronic component chip sealing process and the portions (the 1 st side and the 2 nd side) in the sheet.

Further, the sealing resin material for the electronic component chip is required to have heat dissipation properties. As electronic component chips become more functional, sealing resin materials are required to have higher heat dissipation properties. In order to ensure heat dissipation of the sealing resin material, conventionally, an inorganic filler having high thermal conductivity has been added to the sealing resin material. However, the incorporation of the inorganic filler into the sealing resin sheet as the sealing resin material affects the fluidity of the sealing resin sheet in the sealing process of the electronic component chip. In the conventional sealing resin sheet, the fluidity during heating tends to be reduced as the amount of the inorganic filler to be added is increased.

The present invention provides a sealing resin sheet which is used for sealing an electronic component chip mounted on a base material in a state of facing the base material through a gap, and is suitable for both heat dissipation and hollow sealing performance. The present invention also provides an electronic component device in which an electronic component chip is sealed with such a sealing resin sheet.

Means for solving the problems

The present invention [1] includes a sealing resin sheet comprising a 1 st sealing resin layer and a 2 nd sealing resin layer in this order in a thickness direction, wherein the 1 st sealing resin layer contains a 1 st thermosetting resin, a layered silicate compound, and a 1 st inorganic filler other than the layered silicate compound, the 2 nd sealing resin layer contains a 2 nd thermosetting resin and a 2 nd inorganic filler, and the sealing resin sheet has a thermal conductivity of 2W/m · K or more after curing.

The sealing resin sheet can be used for: the electronic component chip mounted on the base material in a state of facing the base material with the gap therebetween is sealed through the following pressing step and curing step. In the pressing step, the sealing resin sheet is pressed against the substrate while being heated and softened in a state where the 1 st sealing resin layer side of the sealing resin sheet is in contact with the electronic component chip on the substrate. In this step, the gap is closed along the side surface of the electronic component chip by the 1 st sealing resin layer which is in close contact with the base material around the electronic component chip. In the curing step, the sealing resin sheet covering the electronic component chip is further heated and cured. Thereby, a cured resin portion is formed around the electronic component chip on the base material, and the electronic component chip is sealed.

In the sealing resin sheet, as described above, the 1 st sealing resin layer on the side (the 1 st side) in contact with the electronic component chip contains the layered silicate compound. In the 1 st sealing resin layer, the phyllosilicate compound exhibits thixotropy such that the 1 st sealing resin layer undergoes lower viscosity change when receiving a pressing force than when not receiving a pressing force. Therefore, the constitution in which the 1 st sealing resin layer contains a layer silicate compound is suitable for: in the pressing step in which the 1 st sealing resin layer is subjected to a pressing force, the layer is made highly fluid, while in the curing step, the layer is made less fluid by suppressing a decrease in viscosity due to high-temperature heating of the 1 st sealing resin layer. The high fluidity of the 1 st sealing resin layer in the pressing step contributes to the formation of a cured resin portion that appropriately covers the electronic component chip from the sealing resin sheet. The low fluidity of the 1 st sealing resin layer in the curing step contributes to suppressing excessive entry (excessive entry) of the sealing resin into the gap between the base material and the electronic component chip. The 1 st sealing resin layer having both high fluidity and low fluidity is suitable for sealing the electronic component chip in a hollow state on the substrate.

As described above, the sealing resin sheet has a thermal conductivity of 2W/m · K or more after curing. Such a configuration is suitable for ensuring good heat dissipation properties as a sealing resin material in the sealing resin sheet.

In the sealing resin sheet, as described above, the 1 st sealing resin layer contains the 1 st inorganic filler in addition to the layered silicate compound, and the 2 nd sealing resin layer contains the 2 nd inorganic filler. Such a configuration is suitable for ensuring thermal conductivity of the sealing resin sheet, and therefore contributes to achieving thermal conductivity of 2W/m · K or more after curing the sheet.

The invention [2] includes the sealing resin sheet according to [1], wherein a ratio of a melt viscosity of the 1 st sealing resin layer at 90 ℃ to a melt viscosity of the 2 nd sealing resin layer at 90 ℃ is 4 or more.

Such a configuration is preferable for achieving both low fluidity of the 1 st sealing resin layer and high fluidity of the 2 nd sealing resin layer in the sealing resin sheet that is temporarily softened by heating at high temperature in the curing step. In the curing step, the high fluidity of the 2 nd sealing resin layer contributes to the planarization of the exposed surface of the sealing resin sheet on the 2 nd sealing resin layer side.

The invention [3] includes the sealing resin sheet according to [1] or [2], wherein the melt viscosity of the 1 st sealing resin layer at 90 ℃ is 110kPa · s or more and 500kPa · s or less.

Such a configuration is preferable for suppressing the excessive entrance in the curing step.

The invention [4] includes the sealing resin sheet according to any one of [1] to [3], wherein the 1 st inorganic filler and/or the 2 nd inorganic filler is at least one selected from the group consisting of aluminum oxide, aluminum nitride, boron nitride, silicon nitride, and silicon carbide.

Such a configuration is preferable for ensuring thermal conductivity of the sealing resin sheet.

The invention [5] includes the sealing resin sheet according to any one of [1] to [4], wherein a mass ratio of an amount of the layer silicate compound to a total amount of the layer silicate compound and the 1 st inorganic filler in the 1 st sealing resin layer is 0.01 or more and 0.1 or less.

Such a configuration is preferable for ensuring thermal conductivity of the sealing resin sheet and achieving both high fluidity in the pressing step and low fluidity in the curing step of the 1 st sealing resin layer.

The invention [6] includes the sealing resin sheet according to any one of [1] to [5], wherein a content ratio of the inorganic filler in each sealing resin layer is 83 mass% or more.

Such a configuration is preferable for ensuring thermal conductivity of the sealing resin sheet. This configuration is preferable for suppressing expansion and contraction due to a temperature change in the sealing resin sheet.

The invention [7] includes the sealing resin sheet according to any one of [1] to [6], wherein a content ratio of the inorganic filler in each sealing resin layer is 90% by mass or less.

Such a configuration is preferable for ensuring the fluidity of the sealing resin sheet in the pressing step.

The invention [8] includes the resin sheet for sealing according to any one of [1] to [7], wherein the following entry length L shown in the evaluation test of the entry length for carrying out the following 1 st step to 4 th step is 0 μm or more and 50 μm or less.

Entry length evaluation test

Step 1: preparing a dummy chip mounting substrate including a glass substrate and a dummy chip having a size of 1mm × 1mm × 200 μm in thickness, the dummy chip being bonded to the glass substrate via a bump in a state of facing the glass substrate with a gap therebetween, the gap having a length of 50 μm from the glass substrate to the dummy chip;

step 2: pressing the sealing resin sheet toward the glass substrate by vacuum platen pressing in a state where the 1 st sealing resin layer side of the sealing resin sheet is in contact with the dummy chip on the glass substrate, under conditions of a temperature of 70 ℃, a degree of vacuum of 1.6kPa or less, a pressure of 0.1MPa, and a pressure time of 40 seconds, and closing an edge end of the void by sealing the 1 st sealing resin layer of the glass substrate around the dummy chip;

and 3, step 3: after the step 2, heating the sealing resin sheet at 150 ℃ for 1 hour under atmospheric pressure to cure the sealing resin sheet;

and 4, step 4: and (3) measuring a length L of the sealing resin sheet entering the space after the step (3).

The configuration in which the penetration length shown in the above penetration length evaluation test is 0 μm or more and 50 μm or less is preferable for suppressing excessive penetration of the sealing resin into the gap between the substrate and the electronic component chip in the electronic component chip sealing process using the sealing resin sheet and including the pressing step and the curing step as described above.

The invention [9] includes an electronic component device including a base material, an electronic component chip mounted on the base material in a state of facing the base material with a gap therebetween, and a cured resin portion formed of the sealing resin sheet according to any one of [1] to [8] and sealing the electronic component chip and the gap.

In this electronic component device, the electronic component chip is sealed by the cured resin portion formed of the sealing resin sheet, and therefore, it is suitable for achieving both heat dissipation and hollow sealing properties in the cured resin portion.

Brief description of the drawings

Fig. 1 is a schematic cross-sectional view of an embodiment of a sealing resin sheet of the present invention.

Fig. 2A to 2D show a method for sealing an electronic component chip on a base material using the sealing resin sheet shown in fig. 1. Fig. 2A shows a step of preparing a sealing resin sheet, fig. 2B shows a step of disposing a work and the sealing resin sheet between pressing plates in a flat press, fig. 2C shows a pressing step, and fig. 2D shows a curing step.

Fig. 3A to 3D show a method for sealing a dummy chip on a base material using the sealing resin sheets of examples and comparative examples. Fig. 3A shows a step of preparing a sealing resin sheet, fig. 3B shows a step of disposing a work and the sealing resin sheet between pressing plates in a flat press, fig. 3C shows a pressing step, and fig. 3D shows a curing step.

Description of the reference numerals

Resin sheet for X-ray sealing

H thickness direction

11. Sealing resin layer (1 st sealing resin layer)

12. Sealing resin layer (No. 2 sealing resin layer)

W workpiece

S substrate

Sa mounting surface

21. Electronic component chip

21a main surface

21b side surface

22. Bump electrode

P1 st pressing plate

P2 nd pressing plate

Y electronic component device

10. Cured resin part

Detailed Description

The sealing resin sheet X, which is an embodiment of the sealing resin sheet of the present invention, is a sheet-like sealing resin material for sealing an electronic component chip such as a semiconductor chip, and includes a sealing resin layer 11 (1 st sealing resin layer) and a sealing resin layer 12 (2 nd sealing resin layer) in this order in a thickness direction H as shown in fig. 1. The sealing resin sheet X is spread in a direction orthogonal to the thickness direction H.

The sealing resin layer 11 is a layer formed of the 1 st thermosetting composition. The 1 st thermosetting composition contains a 1 st thermosetting resin, a layer silicate compound, and an inorganic filler (1 st inorganic filler) other than the layer silicate compound. That is, the sealing resin layer 11 contains the 1 st thermosetting resin, the layer silicate compound, and the 1 st inorganic filler. The sealing resin layer 11 is in a semi-cured state (B-stage state).

Examples of the 1 st thermosetting resin include epoxy resins, silicone resins, urethane resins, polyimide resins, urea resins, melamine resins, and unsaturated polyester resins. These 1 st thermosetting resins may be used alone or in combination of two or more. The content ratio of the 1 st thermosetting resin in the 1 st thermosetting composition is preferably 3% by mass or more, and more preferably 3.5% by mass or more. The content ratio of the 1 st thermosetting resin in the 1 st thermosetting composition is preferably 30% by mass or less, and more preferably 25% by mass or less.

The 1 st thermosetting resin preferably comprises an epoxy resin. Examples of the epoxy resin include a 2-functional epoxy resin and a 3-or more-functional epoxy resin. Examples of the 2-functional epoxy resin include a bisphenol a type epoxy resin, a bisphenol F type epoxy resin, a modified bisphenol a type epoxy resin, a modified bisphenol F type epoxy resin, and a biphenyl type epoxy resin. Examples of the 3-or more-functional polyfunctional epoxy resin include a phenol novolac type epoxy resin, a cresol novolac type epoxy resin, a trishydroxyphenylmethane type epoxy resin, a tetraphenolethane type epoxy resin, and a dicyclopentadiene type epoxy resin. These epoxy resins may be used alone or in combination of two or more. As the epoxy resin, a 2-functional epoxy resin is preferably used, and bisphenol F type epoxy and/or bisphenol a type epoxy resin is more preferably used.

The epoxy equivalent of the epoxy resin is preferably 10g/eq or more, more preferably 50g/eq or more, and still more preferably 100g/eq or more. The epoxy equivalent of the epoxy resin is preferably 650g/eq or less, more preferably 600g/eq or less, and still more preferably 550g/eq or less. When the 1 st thermosetting resin contains a plurality of epoxy resins, the weighted average epoxy equivalent weight of the plurality of epoxy resins is preferably 10g/eq or more, more preferably 50g/eq or more, and still more preferably 100g/eq or more. The weighted average epoxy equivalent is preferably 650g/eq or less, more preferably 600g/eq or less, and still more preferably 550g/eq or less.

In the case of using an epoxy resin, the 1 st thermosetting resin preferably contains a phenol resin as a curing agent for the epoxy resin. Such a configuration is suitable for forming a sealing material having excellent sealing reliability because the sealing resin sheet X after curing exhibits high heat resistance and high chemical resistance. Preferred examples of the phenol resin include a phenol novolac type phenol resin and a phenol triphenylmethane type resin. Examples of the phenol novolac resin include phenol novolac resin, phenol aralkyl resin, trishydroxyphenylmethane novolac resin, cresol novolac resin, tert-butylphenol novolac resin, and nonylphenol novolac resin. These phenol resins may be used alone or in combination of two or more.

In the 1 st thermosetting composition, the amount of hydroxyl groups in the phenol resin as the curing agent is preferably 0.7 equivalent or more, more preferably 0.9 equivalent or more, relative to 1 equivalent of epoxy groups in the epoxy resin. In the 1 st thermosetting composition, the amount of hydroxyl groups in the phenol resin as a curing agent is preferably 1.5 equivalents or less, more preferably 1.2 equivalents or less, relative to 1 equivalent of epoxy groups in the epoxy resin. The amount of the phenol resin as the curing agent is preferably 20 parts by mass or more, and more preferably 40 parts by mass or more, per 100 parts by mass of the epoxy resin. The amount of the phenol resin as the curing agent is preferably 80 parts by mass or less, and more preferably 60 parts by mass or less, per 100 parts by mass of the epoxy resin.

The 1 st thermosetting composition preferably comprises a curing accelerator. The curing accelerator is a catalyst (heat curing catalyst) that accelerates curing of the 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 the organic phosphorus compound include triphenylphosphine, tricyclohexylphosphine, tributylphosphine, and methyldiphenylphosphine. As the curing accelerator, an imidazole compound is preferably used, and 2-phenyl-4, 5-dihydroxymethylimidazole is more preferably used. The amount of the curing accelerator added is, for example, 0.05 parts by mass or more and, for example, 5 parts by mass or less with respect to 100 parts by mass of the 1 st thermosetting resin.

The layer silicate compound is a component that makes the 1 st thermosetting composition exhibit thixotropy and tackifies the 1 st thermosetting composition, and is dispersed in the 1 st thermosetting composition. Examples of the layered silicate compound include smectite, kaolinite, halloysite, talc, and mica. Examples of smectites include montmorillonite, beidellite, nontronite, saponite, hectorite, sauconite, and stevensite. As the layer silicate compound, smectite is preferably used, and montmorillonite is more preferably used, from the viewpoint of easy mixing with the thermosetting resin.

The layered silicate compound may be an unmodified product whose surface is not modified, or a modified product whose surface is modified with an organic component. For example, from the viewpoint of affinity with the 1 st thermosetting resin, it is preferable to use a layer silicate compound whose surface is modified with an organic component, more preferably use an organized smectite whose surface is modified with an organic component, and still more preferably use an organized bentonite whose surface is modified with an organic component.

Examples of the organic component include organic cations (onium ions) such as ammonium, imidazolium, pyridinium, and phosphonium. Examples of ammonium include dimethyldistearylammonium, distearylammonium, octadecylammonium, hexylammonium, octylammonium, 2-hexylammonium, dodecylammonium and trioctylammonium. Examples of the imidazolium include methylstearylimidazolium, distearylimidazolium, methylhexylimidazolium, dihexylimidazolium, methyloctylimidazolium, dioctylimidazolium, methyldodecylimidazolium, and didodecylimidazolium. Examples of the pyridinium include stearyl pyridinium, hexyl pyridinium, octyl pyridinium, and dodecyl pyridinium. Examples of the phosphonium include dimethyl distearyl phosphonium, octadecyl phosphonium, hexyl phosphonium, octyl phosphonium, 2-hexyl phosphonium, dodecyl phosphonium and trioctyl phosphonium. The organic cation may be used alone or in combination of two or more. As the organic cation, ammonium is preferably used, and dimethyldistearylammonium is more preferably used.

The organic phyllosilicate compound is preferably an organic smectite whose surface is modified with ammonium, and more preferably an organic bentonite whose surface is modified with dimethyl distearyl ammonium.

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

The average particle size of the layered silicate compound is a median particle size (a particle size having a cumulative frequency of volume from a small diameter side of 50%) in a volume-based particle size distribution, and is determined based on a particle size distribution obtained by, for example, a laser diffraction/scattering method (the same applies to the average particle size of other inorganic fillers).

As the layer silicate compound, commercially available products can be used. As a commercial product of the organized bentonite, for example, S-BEN series (manufactured by HOJUN) can be cited.

The content ratio R1 of the layered silicate compound in the 1 st thermosetting composition (i.e., the content ratio R1 of the layered silicate compound in the sealing resin layer 11) is preferably 1% by mass or more, more preferably 1.5% by mass or more, and still more preferably 2% by mass or more. Such a configuration is preferable for thickening the sealing resin layer 11 and for exhibiting thixotropy in the sealing resin layer 11 that causes lower viscosity when a pressing force is applied than when no pressing force is applied. From the viewpoint of avoiding excessive thickening of the 1 st thermosetting composition, the content ratio R1 is preferably 6% by mass or less, more preferably 5% by mass or less, and still more preferably 4% by mass or less.

Examples of the inorganic filler 1 include aluminum oxide, aluminum nitride, aluminum hydroxide, magnesium oxide, magnesium hydroxide, aluminum borate whisker, and boron nitride. The 1 st inorganic filler may be a silicon compound other than a layered silicate compound. Examples of the silicon compound include silicon nitride, silicon carbide, and silicon dioxide. These inorganic fillers may be used alone, or two or more kinds thereof may be used in combination. From the viewpoint of ensuring thermal conductivity of the sealing resin layer 11, the 1 st inorganic filler is preferably at least one selected from the group consisting of alumina, aluminum nitride, boron nitride, silicon nitride, and silicon carbide.

Examples of the shape of the 1 st inorganic filler include a substantially spherical shape, a substantially plate-like shape, a substantially needle-like shape, and an indefinite shape, and a substantially spherical shape is preferable.

The average particle diameter of the 1 st inorganic filler (the average of the maximum length of the inorganic filler in the case where the 1 st inorganic filler has a shape other than a substantially spherical shape) is preferably 0.1 μm or more, and more preferably 0.5 μm or more. The average particle diameter is preferably 50 μm or less, more preferably 20 μm or less, and still more preferably 10 μm or less.

The surface of the 1 st inorganic filler may be partially or entirely treated with a surface treatment agent such as a silane coupling agent.

The content ratio of the 1 st inorganic filler in the 1 st thermosetting composition (sealing resin layer 11) is preferably 75% by mass or more, more preferably 78% by mass or more, and still more preferably 80% by mass or more. Such a configuration is preferable for ensuring thermal conductivity of the sealing resin layer 11. This configuration is preferable for suppressing expansion and contraction due to a temperature change in the sealing resin layer 11. The content ratio is preferably 90% by mass or less, more preferably 85% by mass or less, and still more preferably 83% by mass or less. Such a configuration is preferable for avoiding excessive thickening of the 1 st thermosetting composition and ensuring fluidity of the sealing resin layer 11 in a pressing step to be described later.

The content ratio R2 of the inorganic filler (the layer silicate compound and the 1 st inorganic filler) in the 1 st thermosetting composition is preferably 83 mass% or more, more preferably 84 mass% or more, and still more preferably 85 mass% or more. Such a configuration is preferable for ensuring thermal conductivity of the sealing resin sheet. This configuration is preferable for suppressing expansion and contraction due to a temperature change in the sealing resin layer 11. The content ratio R2 is preferably 90% by mass or less, more preferably 89% by mass or less, and further preferably 88% by mass or less. Such a configuration is preferable for avoiding excessive thickening of the 1 st thermosetting composition and ensuring fluidity of the sealing resin layer 11 in a pressing step to be described later.

The mass ratio (R1/R2) of the amount of the layer silicate compound in the sealing resin layer 11 to the total amount of the layer silicate compound and the 1 st inorganic filler is preferably 0.01 or more, more preferably 0.015 or more, further preferably 0.02 or more, particularly preferably 0.03 or more, and further preferably 0.1 or less, more preferably 0.08 or less, further preferably 0.07 or less. Such a configuration is preferable for securing the thermal conductivity of the sealing resin sheet X and for achieving both a high fluidity of the sealing resin layer 11 in the pressing step described later and a low fluidity in the curing step described later.

The 1 st thermosetting composition may contain other ingredients. Examples of the other components include a thermoplastic resin, a pigment, and a silane coupling agent.

Examples of the thermoplastic resin include acrylic resins, natural rubbers, butyl rubbers, isoprene rubbers, chloroprene rubbers, ethylene-vinyl acetate copolymers, ethylene-acrylic acid ester copolymers, polybutadiene resins, polycarbonate resins, thermoplastic polyimide resins, polyamide resins, phenoxy resins, saturated polyester resins (PET and the like), polyamideimide resins, fluorine resins, and styrene-isobutylene-styrene block copolymers. These thermoplastic resins may be used alone or in combination of two or more.

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 polymers which are polymers of monomer components including alkyl (meth) acrylates having a linear or branched alkyl group and other monomers (copolymerizable monomers).

Examples of the alkyl group of the alkyl (meth) acrylate include alkyl groups having 1 to 6 carbon atoms. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, a tert-butyl group, an isobutyl group, a pentyl group, and a hexyl group.

Examples of the copolymerizable monomer include a carboxyl group-containing monomer, an acid anhydride monomer, a glycidyl group-containing monomer, a hydroxyl group-containing monomer, a sulfonic acid group-containing monomer, a phosphoric acid group-containing monomer, and acrylonitrile. Examples of the carboxyl group-containing monomer include acrylic acid, methacrylic acid, carboxyethyl acrylate, carboxypentyl acrylate, itaconic acid, maleic acid, fumaric acid, and crotonic acid. Examples of the acid anhydride monomer include maleic anhydride and itaconic anhydride. Examples of the glycidyl group-containing monomer include glycidyl acrylate and glycidyl methacrylate. Examples of the hydroxyl group-containing monomer include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 8-hydroxyoctyl (meth) acrylate, 10-hydroxydecyl (meth) acrylate, and 12-hydroxylauryl (meth) acrylate. Examples of the sulfonic acid group-containing monomer include styrenesulfonic acid, allylsulfonic acid, 2- (meth) acrylamido-2-methylpropanesulfonic acid, (meth) acrylamidopropanesulfonic acid, sulfopropyl (meth) acrylate, and (meth) acryloyloxynaphthalenesulfonic acid. Examples of the monomer having a phosphate group include 2-hydroxyethyl acryloyl phosphate. These copolymerizable monomers may be used alone or in combination of two or more.

The glass transition temperature (Tg) of the thermoplastic resin is preferably-70 ℃ or higher. The glass transition temperature is preferably 0 ℃ or lower, more preferably-5 ℃ or lower.

As the glass transition temperature (Tg) of the polymer, a glass transition temperature (theoretical value) determined based on the following Fox equation can be used. The formula Fox is a relation between the glass transition temperature Tg of the polymer and the glass transition temperature Tgi of a homopolymer of the monomer constituting the polymer. In the following Fox formula, tg represents the glass transition temperature (. Degree. C.) of a polymer, wi represents the weight fraction of a monomer i constituting the polymer, and Tgi represents the glass transition temperature (. Degree. C.) of a homopolymer composed of the monomer i. As the glass transition temperature of the homopolymer, a literature value can be used, and for example, glass transition temperatures of various homopolymers are listed in "Polymer Handbook" (4 th edition, john Wiley & Sons, inc., 1999) and "synthetic resin entry for coating of New high molecular library 7" (North Ooka Co., ltd., polymer society, 1995). On the other hand, the glass transition temperature of a homopolymer of a monomer can also be determined by a method specifically described in jp 2007-51271 a.

Fox formula 1/(273 + Tg) = Σ [ Wi/(273 + Tgi) ]

The weight average molecular weight of the thermoplastic resin is preferably 10 ten thousand or more, and preferably 30 ten thousand or more. The weight average molecular weight of the thermoplastic resin is preferably 200 ten thousand or less, and more preferably 150 ten thousand or less. The weight average molecular weight of the resin was determined by Gel Permeation Chromatography (GPC) and based on standard polystyrene conversion values.

The content ratio of the thermoplastic resin in the 1 st thermosetting composition is preferably 0.5% by mass or more, more preferably 1% by mass or more, more preferably 1.3% by mass or more, and still more preferably 1.5% by mass or more. The content ratio is preferably 30% by mass or less, and more preferably 20% by 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, 1 μm or less. The particle diameter of the pigment is an arithmetic mean diameter obtained by observing the pigment with an electron microscope. The content of the pigment in the 1 st 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 silane coupling agents containing an epoxy group. Examples of the epoxy group-containing silane coupling agent include 3-glycidoxyalkyldialkyldialkoxysilane and 3-glycidoxyalkyltrialkoxysilane. Examples of the 3-glycidoxydialkyldialkoxysilane include 3-glycidoxypropylmethyldimethoxysilane and 3-glycidoxypropylmethyldiethoxysilane. Examples of the 3-glycidoxyalkyltrialkoxysilane include 3-glycidoxypropyltrimethoxysilane and 3-glycidoxypropyltriethoxysilane. As the 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 1 st thermosetting composition is preferably 0.1% by mass or more, and more preferably 1% by mass or more. The content ratio is preferably 10% by mass or less, and more preferably 5% by mass or less.

The sealing resin layer 12 is a layer formed of the 2 nd thermosetting composition. The 2 nd thermosetting composition comprises a 2 nd thermosetting resin and a 2 nd inorganic filler material. That is, the sealing resin layer 12 contains the 2 nd thermosetting resin and the 2 nd inorganic filler. The sealing resin layer 12 is in a semi-cured state (B-stage state).

Examples of the 2 nd thermosetting resin include the 1 st thermosetting resin described above. The content ratio of the 2 nd thermosetting resin in the 2 nd thermosetting composition is preferably 2% by mass or more, and more preferably 3% by mass or more. The content ratio of the 2 nd thermosetting resin in the 2 nd thermosetting composition is preferably 20% by mass or less, and more preferably 15% by mass or less.

The 2 nd thermosetting resin preferably comprises an epoxy resin. Examples of the epoxy resin include the epoxy resins described above for the 1 st thermosetting composition, and 2-functional epoxy resins are preferably used, and bisphenol a type epoxy resins and/or bisphenol F type epoxy resins are more preferably used. The preferred range of the epoxy equivalent of the epoxy resin in the 2 nd thermosetting composition is the same as the range described above as the preferred range of the epoxy equivalent of the epoxy resin in the 1 st thermosetting composition.

In the case where an epoxy resin is used as the 2 nd thermosetting resin, the 2 nd thermosetting resin preferably contains a phenol resin as a curing agent for the epoxy resin. Preferred examples of the phenol resin include a phenol novolac type phenol resin and a phenol triphenylmethane type resin. The amount of hydroxyl groups in the phenol resin as a curing agent with respect to 1 equivalent of epoxy groups of the epoxy resin in the 2 nd thermosetting composition is the same as the amount of hydroxyl groups in the phenol resin as a curing agent with respect to 1 equivalent of epoxy groups of the epoxy resin as described above with respect to the 1 st thermosetting composition. The amount of the phenol resin as the curing agent in the 2 nd thermosetting composition with respect to 100 parts by mass of the epoxy resin is the same as the amount of the phenol resin as the curing agent in the 1 st thermosetting composition with respect to 100 parts by mass of the epoxy resin as described above.

The 2 nd thermosetting composition preferably contains a curing accelerator. Examples of the curing accelerator include the curing accelerators described above for the 1 st thermosetting composition. The amount of the curing accelerator to be blended is, for example, 0.05 parts by mass or more and 5 parts by mass or less with respect to 100 parts by mass of the 2 nd thermosetting resin.

Examples of the 2 nd inorganic filler include the 1 st inorganic filler as described above with respect to the 1 st thermosetting composition. From the viewpoint of securing the content of the inorganic filler other than the layer silicate compound in the 2 nd thermosetting composition, the 2 nd inorganic filler preferably does not contain the layer silicate compound. That is, the 2 nd inorganic filler is preferably an inorganic filler other than the layer silicate compound. In addition, from the viewpoint of ensuring the thermal conductivity of the sealing resin layer 12, the 2 nd inorganic filler is preferably at least one selected from the group consisting of alumina, aluminum nitride, boron nitride, silicon nitride, and silicon carbide.

Examples of the shape of the 2 nd inorganic filler include a substantially spherical shape, a substantially plate-like shape, a substantially needle-like shape, and an indefinite shape, and a substantially spherical shape is preferable. The average particle diameter of the 2 nd inorganic filler (the average of the maximum lengths of the 2 nd inorganic filler in the case where the 2 nd inorganic filler has a shape other than a substantially spherical shape) is preferably 0.1 μm or more, and more preferably 0.5 μm or more. The average particle diameter is preferably 50 μm or less, more preferably 20 μm or less, and still more preferably 10 μm or less. The surface of the 2 nd inorganic filler may be partially or entirely treated with a surface treatment agent such as a silane coupling agent.

The content ratio R3 of the 2 nd inorganic filler in the 2 nd thermosetting composition (sealing resin layer 12) is preferably 75% by mass or more, more preferably 78% by mass or more, and still more preferably 80% by mass or more. Such a configuration is preferable for ensuring thermal conductivity of the sealing resin layer 12. This configuration is preferable for suppressing expansion and contraction due to a temperature change in the sealing resin layer 12. The content ratio R3 is preferably 95% by mass or less, more preferably 93% by mass or less, and further preferably 91% by mass or less. Such a configuration is suitable for ensuring the fluidity of the sealing resin layer 12 in the pressing step described later. In addition, from the viewpoint of ensuring the thermal conductivity of the sealing resin layer 12 and thus the thermal conductivity of the sealing resin sheet X, it is preferable that the content ratio R3 of the 2 nd inorganic filler is greater than the content ratio R2 of the 1 st inorganic filler.

The 2 nd thermosetting composition may contain other ingredients. Examples of the other components include the same thermoplastic resin, pigment and silane coupling agent as those described above with respect to the 1 st thermosetting composition. The compounding amounts of the other components are, for example, the same as those described above with respect to the other components in the 1 st thermosetting composition.

The sealing resin sheet X can be produced by, for example, forming the sealing resin layer 11 (1 st sealing resin layer) and the sealing resin layer 12 (2 nd sealing resin layer) separately, and then bonding the sealing resin layer 11 and the sealing resin layer 12 together.

The sealing resin layer 11 can be formed, for example, as follows. First, the respective components described above with respect to the 1 st thermosetting composition and a solvent were mixed at a prescribed ratio to prepare a varnish of the 1 st thermosetting composition. Examples of the solvent include methyl ethyl ketone, ethyl acetate, and toluene. Next, the varnish is applied onto a substrate such as a release sheet to form a coating film, and then the coating film is dried by heating. Thereby, a resin film (1 st resin film) having a sheet shape and in a semi-cured state was obtained as the sealing resin layer 11. The sealing resin layer 11 may be formed by laminating a plurality of the 1 st resin films.

The sealing resin layer 12 can be formed, for example, as follows. First, the respective components described above with respect to the 2 nd thermosetting composition and a solvent are mixed at a prescribed ratio to prepare a varnish of the 2 nd thermosetting composition. Next, the varnish is applied onto a substrate such as a release sheet to form a coating film, and then the coating film is dried by heating. Thereby, a resin film (2 nd resin film) having a sheet shape and in a semi-cured state was obtained as the sealing resin layer 12. The sealing resin layer 12 may be formed by laminating a plurality of the 2 nd resin films.

The sealing resin sheet X can be produced by forming the sealing resin layer 11 on the base material and forming the sealing resin layer 12 on the sealing resin layer 11. Alternatively, the sealing resin sheet X may be produced by forming the sealing resin layer 12 on the base material and forming the sealing resin layer 11 on the sealing resin layer 12.

The thickness of the sealing resin layer 11 is preferably 30 μm or more, more preferably 50 μm or more, and further preferably 60 μm or more. Such a configuration is preferable from the viewpoint of suppressing the breakage of the sealing resin layer 11 in the pressing step described later. The thickness of the sealing resin layer 11 is preferably 300 μm or less, more preferably 250 μm or less, still more preferably 200 μm or less, and particularly preferably 180 μm or less. Such a configuration is preferable for ensuring the fluidity of the sealing resin sheet X in the pressing step described later and for filling the gaps between adjacent chips with the sealing resin.

The thickness H2 of the sealing resin layer 12 is preferably 40 μm or more, more preferably 60 μm or more, further preferably 80 μm or more, and particularly preferably 100 μm or more. Such a configuration is preferable from the viewpoint of suppressing the breakage of the sealing resin layer 12 in the pressing step described later. The thickness H2 of the sealing resin layer 12 is, for example, 300 μm or less, preferably 250 μm or less, more preferably 200 μm or less, and particularly preferably 180 μm or less. Such a configuration is preferable for ensuring the fluidity of the sealing resin sheet X in the pressing step described later and filling the gaps between the adjacent chips with the sealing resin.

The ratio of the thickness H2 to the thickness H1 is preferably 1 or more, more preferably 2 or more, and further preferably 3 or more, and is preferably 6 or less, more preferably 5 or less, and further preferably 4.5 or less. Such a configuration is preferable for suppressing the breakage of the sealing resin layer 11 in the pressing step described later and for achieving a balance in the fluidity of the entire sealing resin sheet X.

The melt viscosity Z1 of the sealing resin layer 11 at 90 ℃ is preferably 110kPa · s or more, more preferably 120kPa · s or more, still more preferably 150kPa · s or more, and particularly preferably 180kPa · s or more. Such a configuration is preferable for suppressing excessive penetration (excessive penetration) of the sealing resin layer 11, which is temporarily softened by high-temperature heating in a curing step described later, into a gap between the base material and the electronic component chip. The melt viscosity of the sealing resin layer can be determined by measuring the viscoelasticity of the sealing resin layer. Viscoelasticity measurements can be performed by rheometry. As the rheometer, for example, "HAAKE MARS III" manufactured by Thermo Fisher Scientific Co., ltd. In the measurement, the frequency was set to 1Hz, the strain value was set to 0.005%, the temperature range was set to 50 ℃ to 90 ℃, and the temperature rise rate was set to 30 ℃/min. Specifically, the melt viscosity can be determined by the following measurement method with respect to examples.

The melt viscosity Z1 of the sealing resin layer 11 at 90 ℃ is preferably 500kPa · s or less, more preferably 400kPa · s or less, and still more preferably 380kPa · s or less. Such a configuration is preferable for securing fluidity of the sealing resin layer 11 in a pressing step described later.

The melt viscosity Z2 of the sealing resin layer 12 at 90 ℃ is preferably 1kPa · s or more, more preferably 3kPa · s or more, and preferably 100kPa · s or less, more preferably 80kPa · s or less. Such a configuration is preferable for securing the fluidity of the sealing resin layer 12 in the pressing step described later.

The ratio of the melt viscosity Z1 to the melt viscosity Z2 is preferably 4 or more, more preferably 10 or more, further preferably 20 or more, and particularly preferably 30 or more. Such a configuration is preferable for achieving both low fluidity of the sealing resin layer 11 and high fluidity of the sealing resin layer 12 in the sealing resin sheet X that is temporarily softened by heating at a high temperature in a curing step described later. In the curing step, the high fluidity of the sealing resin layer 12 contributes to flattening of the exposed surface of the sealing resin layer 12 side of the sealing resin sheet X.

The sealing resin sheet X (sealing resin layers 11 and 12) has a thermal conductivity of 2W/m · K or more after being cured by heating at 150 ℃ for 1 hour. The thermal conductivity is preferably 2.2W/mK or more, more preferably 2.5W/mK or more, still more preferably 2.8W/mK or more, and particularly preferably 3W/mK or more. Such a configuration is suitable for ensuring good heat dissipation properties as a sealing resin material in the sealing resin sheet X. The thermal conductivity of the sealing resin sheet can be determined, for example, by the method described below with respect to the examples.

The following penetration length L of the sealing resin sheet X, which is shown in the penetration length evaluation tests performed in the following steps 1 to 4, is preferably 50 μm or less, more preferably 30 μm or less, and still more preferably 20 μm or less. The penetration length L is preferably 0 μm or more. Such a configuration is preferable for suppressing excessive penetration of the sealing resin into the gap between the substrate and the electronic component chip in the electronic component chip sealing process including the pressing step and the curing step described below using the sealing resin sheet X.

Entry length evaluation test

Step 1: a dummy chip mounting substrate including a glass substrate and a dummy chip having a size of 1mm x 200 μm in thickness is prepared, the dummy chip is bonded to the glass substrate via a bump in a state of facing the glass substrate with a gap therebetween, and the gap has a length of 50 μm from the glass substrate to the dummy chip.

Step 2: in a state where the sealing resin layer 11 side of the sealing resin sheet X is in contact with the dummy chip on the glass substrate, the sealing resin sheet X is pressed against the glass substrate by vacuum plate pressing under conditions of a temperature of 70 ℃, a degree of vacuum of 1.6kPa or less, a pressure of 0.1MPa, and a pressure time of 40 seconds, and the edge end of the gap is closed by the sealing resin layer 11 adhering to the glass substrate around the dummy chip.

And 3, step 3: after the 2 nd step, curing the sealing resin sheet by heating at 150 ℃ for 1 hour under atmospheric pressure;

and 4, step 4: after the 3 rd step, the length L of the sealing resin sheet entering the void is measured.

Fig. 2A to 2D show a method of sealing an electronic component chip on a base material with a sealing resin sheet X.

In the method, first, as shown in fig. 2A, a sealing resin sheet X is prepared (preparation step).

Next, as shown in fig. 2B, the work W and the sealing resin sheet X are disposed between the 1 st pressing plate P1 and the 2 nd pressing plate P2 provided in the platen press (disposing step).

The workpiece W includes a substrate S and a plurality of chips 21. The substrate S is a base material that is later singulated into individual mounting substrates, and has a mounting surface Sa. The mounting surface Sa is provided with terminals (not shown) for mounting. The chip 21 is an electronic component chip such as a semiconductor chip, and has a main surface 21a and a side surface 21b. The main surface 21a is provided with terminals (not shown) for external connection. The chip 21 is mounted on the substrate S via the bump electrode 22 in a state of facing the substrate S with the gap G interposed therebetween. Each bump electrode 22 is interposed between a terminal provided on the mounting surface Sa of the substrate S and a terminal provided on the main surface 21a of the chip 21, and electrically connects the substrate S and the chip 21.

The mounting height of the chip 21 on the substrate S (the height of the chip 21 from the surface of the substrate S on the side opposite to the substrate S) is, for example, 200 μm or more, preferably 220 μm or more, and more preferably 250 μm or more. The mounting height is, for example, 400 μm or less, preferably 350 μm or less, and more preferably 300 μm or less.

The separation distance between the substrate S and the chip 21 is, for example, 10 μm or more, preferably 15 μm or more, and more preferably 20 μm or more. The separation distance is, for example, 80 μm or less, preferably 60mm or less, and more preferably 50 μm or less.

The plurality of chips 21 are mounted on the mounting surface Sa of the substrate S at intervals in the surface direction. The interval (mounting interval) between the adjacent chips 21 is, for example, 50 μm or more, preferably 100 μm or more, and more preferably 200 μm or more. The interval between the adjacent chips 21 is, for example, 10mm or less, preferably 5mm or less, and more preferably 1mm or less.

In this step, the workpiece W is placed on the 1 st platen P1 so that the substrate S thereof comes into contact with the 1 st platen P1. The sealing resin sheet X is laminated on the workpiece W such that the sealing resin layer 11 is in contact with the chips 21 of the workpiece W.

Next, as shown in fig. 2C, the sealing resin sheet X and the work W are pressed in the thickness direction D by the 1 st pressing plate P1 and the 2 nd pressing plate P2 (pressing step). Specifically, the sealing resin sheet X is pressed against the substrate S while being heated and softened in a state where the sealing resin layer 11 side of the sealing resin sheet X is in contact with the chip 21 on the substrate S.

The pressing pressure is, for example, 0.01MPa or more, preferably 0.05MPa or more. The pressing pressure is, for example, 10MPa or less, preferably 5MPa or less. The pressing time is, for example, 0.3 minutes or more, preferably 0.5 minutes or more. The pressing time is, for example, 10 minutes or less, preferably 5 minutes or less. The heating temperature during pressing is, for example, 40 ℃ or higher, preferably 60 ℃ or higher. The heating temperature is, for example, 100 ℃ or lower, preferably 95 ℃ or lower.

In this step, the sealing resin sheet X is deformed to follow the outer shape of the chip 21 while maintaining the B-stage, covers the side surface 21B of each chip 21, and contacts the mounting surface Sa of the substrate S that does not overlap with the chip 21 in a plan view. The gap G is closed (the edge end of the gap G is closed) along the side surface 21b of the chip 21 by the sealing resin layer 11 that is in close contact with the substrate S around the chip 21.

The deformed sealing resin sheet X is allowed to slightly enter the gap G between the substrate S and the chip 21. Specifically, the sealing resin sheet X is allowed to have an entry length L1 into the gap G with reference to the side surface 21b of the chip 21.

The entry length L1 is preferably 50 μm or less, more preferably 30 μm or less. Such a configuration is suitable for securing a region where wiring can be formed in the mounting surface Sa of the substrate S and the main surface 21a of the chip 21, and therefore contributes to higher functionality of an electronic component device as an electronic component package to be singulated. The penetration length L1 is preferably 0 μm or more. Such a configuration is suitable for appropriately sealing the chip 21 and the gap G so that the gap G does not open to the outside of the resin sealing body in the electronic component device after singulation.

Next, the work W sealed with the sealing resin sheet X is taken out of the platen press, and then, as shown in fig. 2D, the sealing resin sheet X is heated and cured (curing step). Thereby, the cured resin portion 10 is formed around each chip 21 on the substrate S, and each chip 21 is sealed with resin.

The heating temperature (curing temperature) is, for example, 100 ℃ or higher, preferably 120 ℃ or higher. The heating temperature (curing temperature) is, for example, 200 ℃ or lower, preferably 180 ℃ 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.

The penetration length L2 of the voids G in the cured sealing resin sheet X is preferably 50 μm or less, and more preferably 30 μm or less. Such a configuration is suitable for securing a region where wiring can be formed in the mounting surface Sa of the substrate S and the main surface 21a of the chip 21, and therefore contributes to higher functionality of an electronic component device as an electronic component package to be singulated. The entry length L2 is preferably 0 μm or more. Such a configuration is suitable for appropriately sealing the chip 21 and the gap G so that the gap G does not open to the outside of the resin sealing body in the electronic component device after singulation.

Thereafter, the cured resin portion 10 (cured sealing resin sheet X) and the substrate S are cut along a predetermined line by, for example, blade cutting, thereby obtaining an electronic component device Y as a singulated electronic component package (singulation step). The electronic component device Y thus obtained includes: the semiconductor device includes a substrate S as a base material, a chip 21 mounted on the substrate S in a state of facing the substrate S with a gap G therebetween, and a cured resin portion 10 formed of a sealing resin sheet X and sealing the chip 21 and the gap G.

In the sealing resin sheet X, as described above, the sealing resin layer 11 on the side (1 st side) in contact with the chip 21 contains a layered silicate compound. In the sealing resin layer 11, the layered silicate compound exhibits thixotropy in which the sealing resin layer 11 undergoes a lower viscosity change when receiving a pressing force than when not receiving a pressing force. Therefore, the constitution in which the sealing resin layer 11 contains a layer silicate compound is suitable for: in the pressing step (fig. 2C) in which the sealing resin layer 11 is subjected to a pressing force, the layer is made highly fluid, while in the curing step (fig. 2D), the layer is made less fluid by suppressing a decrease in viscosity due to high-temperature heating of the sealing resin layer 11. The high fluidity of the sealing resin layer 11 in the pressing step contributes to the formation of the cured resin portion 10 that properly covers the chip 21 from the sealing resin sheet X. The low fluidity of the sealing resin layer 11 in the curing process helps to suppress excessive entry (excessive entry) of the sealing resin into the gap G between the substrate S and the chip 21. Such a combination of high fluidity and low fluidity of the sealing resin layer 11 is suitable for hollow sealing of the chip 21 on the substrate S.

Further, as described above, the thermal conductivity of the sealing resin sheet X is 2W/m · K or more, preferably 2.2W/m · K or more, more preferably 2.5W/m · K or more, further preferably 2.8W/m · K or more, and particularly preferably 3W/m · K or more. Such a configuration is suitable for ensuring good heat dissipation properties as a sealing resin material in the sealing resin sheet X.

In the sealing resin sheet X, as described above, the sealing resin layer 11 contains the 1 st inorganic filler in addition to the phyllosilicate compound, and the sealing resin layer 12 contains the 2 nd inorganic filler. Such a configuration is suitable for ensuring the thermal conductivity of the sealing resin sheet X, and therefore contributes to achieving a thermal conductivity of 2W/m · K or more after curing the sheet.

As described above, the sealing resin sheet X is suitable for achieving both heat dissipation and hollow sealing properties.

[ examples ]

The present invention will be described more specifically below with reference to examples. The invention is not limited to the embodiments. In addition, specific numerical values such as the blending amount (content), the physical property value, and the parameter used in the following description may be replaced with upper limits (numerical values defined as "below" or "less than") or lower limits (numerical values defined as "above" or "more than") described above in accordance with the blending amount (content), the physical property value, and the parameter described in the above "specific embodiment".

[ production examples 1 to 8]

The resin films of production examples 1 to 8 for forming a sealing resin layer were produced as follows. First, compositions (varnishes) were prepared by mixing the respective components with methyl ethyl ketone as a solvent in the formulations shown in table 1 (in table 1, the units of the respective numerical values representing the compositions are relative "parts by mass". Next, the composition was applied to a polyethylene terephthalate film (PET film) whose surface was subjected to a silicone release treatment to form a coating film. Subsequently, the coating film was dried by heating at 120 ℃ for 2 minutes to prepare a resin film (the resin film was in a B-stage state) on the PET film. The resin films of preparation examples 1 to 7 were prepared to have a thickness of 35 μm. The resin film of preparation example 8 was prepared to have a thickness of 50 μm.

The components used in production examples 1 to 8 are as follows.

Epoxy resin E1: YSLV-80XY, bisphenol F type epoxy resin, high molecular weight epoxy resin manufactured by Nippon Feishiki chemical company, epoxy equivalent 191g/eq, solid at normal temperature, softening point 80 DEG C

Epoxy resin E2: EPICLON EXA-4850-150 manufactured by DIC corporation, bisphenol A epoxy resin having a molecular weight of 900 and an epoxy equivalent of 450g/eq, and being liquid at room temperature

Phenol resin: LVR-8210DL manufactured by Rong chemical company, novolac phenol resin, latent curing agent, hydroxyl equivalent 104g/eq, solid at room temperature, softening point 60 deg.C

Acrylic resin (acrylic polymer): "HME-2006M" manufactured by Industrial Ltd., a methyl ethyl ketone solution having an acid value of 32mgKOH/g, a weight average molecular weight of 129 ten thousand, a glass transition temperature (Tg) -13.9 ℃ and a solid content concentration of 20 mass%, a carboxyl group-containing acrylic resin

Silane coupling agent: KBM-403, 3-glycidoxypropyltrimethoxysilane, manufactured by shin-Etsu chemical Co., ltd

Layered silicate compound: "S-BEN NX" manufactured by HOJUN corporation, an organic bentonite having its surface modified with dimethyl distearyl ammonium

Alumina particles: "AC-9150SME" manufactured by Admatechs corporation, having an average particle diameter of 3 μm

Boron nitride particles: "SGP" manufactured by Denka corporation, plate-like particles having an average particle diameter of 18 μm

Curing accelerator: 2PHZ-PW "manufactured by Siguo chemical industry Co., ltd, 2-phenyl-4, 5-dihydroxymethylimidazole

Pigment: "Carbon Black #20" manufactured by Mitsubishi chemical corporation, having an average particle diameter of 50nm

Solvent: methyl ethyl ketone

[ examples 1 to 6 and comparative example 1]

The sealing resin sheets of examples 1 to 6 and comparative example 1 were prepared. Specifically, the following is described.

In the production of the sealing resin sheet of example 1, 2 sheets (35 μm in thickness) of the resin film of production example 1 were laminated to form a 1 st sealing resin layer (65 μm in thickness), 4 sheets (50 μm in thickness) of the resin film of production example 8 were laminated to form a 2 nd sealing resin layer (195 μm in thickness), and the 1 st and 2 nd sealing resin layers were laminated. The bonding temperature was 90 ℃.

A sealing resin sheet of example 2 was produced in the same manner as the sealing resin sheet of example 1, except that the resin film of example 2 was used instead of the resin film of example 1. A sealing resin sheet of example 3 was produced in the same manner as the sealing resin sheet of example 1, except that the resin film of example 3 was used instead of the resin film of example 1. A sealing resin sheet of example 4 was produced in the same manner as the sealing resin sheet of example 1, except that 4 sheets of the resin film of example 4 were used instead of 2 sheets of the resin film of example 1. A sealing resin sheet of example 5 was produced in the same manner as the sealing resin sheet of example 1, except that the resin film of example 5 was used instead of the resin film of example 1. A sealing resin sheet of example 6 was produced in the same manner as the sealing resin sheet of example 1, except that the resin film of example 6 was used instead of the resin film of example 1. A sealing resin sheet of comparative example 1 was produced in the same manner as in example 1, except that the resin film of production example 7 was used instead of the resin film of production example 1.

Melt viscosity

The 1 st and 2 nd sealing resin layers of the sealing resin sheets of examples 1 to 6 and comparative example 1 were measured for melt viscosity at 90 ℃.

First, 30 sheets of the resin film (thickness: 35 μm) forming the 1 st sealing resin layer were bonded to each of the sealing resin sheets of examples 1 to 6 and comparative example 1 to prepare a 1 st sample film (thickness: 1 mm) for measurement. Subsequently, the viscoelasticity of the film of sample No. 1 was measured. In this measurement, a rheometer (trade name "HAAKE MARS III", manufactured by Thermo Fisher Scientific Co., ltd.) was used to hold the 1 st sample film between a hot plate for heating in the apparatus and a parallel plate (diameter: 8 mm) arranged parallel to the hot plate, and the gap between the plates was set to 0.8mm. Then, the viscosity of the film of sample No. 1 was measured under the conditions of a frequency of 1Hz, a strain value of 0.005%, a temperature range of 50 ℃ to 90 ℃ and a temperature rise rate of 30 ℃/min. On the other hand, 20 sheets of the resin films (50 μm in thickness) forming the 2 nd sealing resin layer of the sealing resin sheets of examples 1 to 6 and comparative example 1 were laminated to prepare a 2 nd sample film (1 mm in thickness) for measurement. The same viscoelastic measurement as the above-described viscoelastic measurement was performed except that the 2 nd sample film was used instead of the 1 st sample film. Table 2 shows the melt viscosity Z1 (kPa · S) at 90 ℃ of the 1 st sealing resin layer and the melt viscosity Z2 (kPa · S) at 90 ℃ of the 2 nd sealing resin layer. The ratio of the melt viscosity Z1 to the melt viscosity Z2 is also shown in table 2.

Heat conductivity

The thermal conductivity of the sealing resin sheets of examples 1 to 6 and comparative example 1 after curing was examined. Specifically, the following is described.

First, the sealing resin sheet was heated at 150 ℃ for 30 minutes under normal pressure to be cured. Thereafter, the thermal diffusivity, specific heat and specific gravity of the cured sealing resin sheet were measured. The thermal diffusion coefficient was measured by a xenon flash method thermal measurement apparatus (product name "LFA447 nanoflash", manufactured by NETZSCH JAPAN corporation). The specific heat was measured by a differential scanning calorimetry measuring apparatus (product name "DSC Q-2000", manufactured by TA instruments) in accordance with JIS-7123. The specific gravity was measured by an electronic balance (product name "AEL-200", manufactured by Shimadzu corporation) by the Archimedes method. The thermal conductivity of the cured sealing resin sheet was determined by the following equation. The thermal conductivity (W/mk) after curing is shown in Table 2.

Thermal conductivity = thermal diffusion coefficient x specific heat x specific gravity

Evaluation of entry Length

The hollow sealability of each of the sealing resin sheets of examples 1 to 6 and comparative example 1 was examined. Specifically, the following is described.

First, as shown in fig. 3A, a sample sheet X' (10 mm in length × 10mm in width) was prepared from a sealing resin sheet. The sample sheet X' includes the 1 st sealing resin layer 11 and the 2 nd sealing resin layer 12 in this order in the thickness direction.

On the other hand, a dummy chip mounting board is prepared as the workpiece W. The dummy chip mounting substrate includes a glass substrate S and a plurality of dummy chips 21' (1 mm × 1mm × 200 μm in thickness). The dummy chip 21' is bonded to the substrate S through the bump electrode 22 in a state of facing the substrate S with the gap G interposed therebetween. The dummy chip 21' has a main surface 21a facing the substrate S and a side surface 21b. The mounting height of the dummy chip 21' is 300 μm. The mounting interval of the dummy chips 21' is 300 μm. The length of the gap G from the substrate S to the dummy chip 21 '(the separation distance between the substrate S and the dummy chip 21') is 50 μm.

Next, as shown in fig. 3B, the workpiece W and the sample piece X' are disposed between the 1 st platen P1 and the 2 nd platen P2 provided in the platen press.

Next, as shown in fig. 3C, the dummy chip 21 'on the substrate S is sealed by vacuum plate pressing with the sample sheet X' under sealing conditions of a temperature of 70 ℃, a degree of vacuum of 1.6kPa or less, a pressure of 0.1MPa, and a pressing time of 40 seconds (pressing step).

Next, as shown in fig. 3D, the sample piece X' is cured by heating at 150 ℃ for 1 hour under atmospheric pressure. Thereby forming the cured resin portion 10.

Then, as shown in the enlarged view of fig. 3D, the length of the sealing resin (a part of the 1 st sealing resin layer 11) derived from the sample piece X ' entering from the side surface 21b to the gap G between the dummy chip 21' and the substrate S is measured as an entering length L (μm) with reference to the side surface 21b of the dummy chip 21 '. The results are shown in table 2.

According to the sealing resin sheets of examples 1 to 6, the penetration length L is 0 μm or more and 50 μm or less, and the dummy chip 21' can be appropriately sealed in a hollow state. In contrast, in the sealing resin sheet of comparative example 1, the 1 st sealing resin layer 11 excessively enters the gap G between the substrate S and the dummy chip 21' in the pressing step, and the cured resin portion 10 excessively entering the gap G is formed in the curing step.

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Claims (9)

1. A sealing resin sheet comprising a 1 st sealing resin layer and a 2 nd sealing resin layer in this order in the thickness direction,

the 1 st sealing resin layer contains a 1 st thermosetting resin, a layered silicate compound, and a 1 st inorganic filler other than the layered silicate compound,

the 2 nd sealing resin layer contains a 2 nd thermosetting resin and a 2 nd inorganic filler material,

the sealing resin sheet has a thermal conductivity of 2W/m.K or more after curing.

2. The sealing resin sheet according to claim 1, wherein a ratio of the melt viscosity of the 1 st sealing resin layer at 90 ℃ to the melt viscosity of the 2 nd sealing resin layer at 90 ℃ is 4 or more.

3. The sealing resin sheet according to claim 1, wherein the melt viscosity of the 1 st sealing resin layer at 90 ℃ is 110kPa s or more and 500kPa s or less.

4. The sealing resin sheet according to claim 1, wherein the 1 st inorganic filler material and/or the 2 nd inorganic filler material is at least one selected from the group consisting of alumina, aluminum nitride, boron nitride, silicon nitride, and silicon carbide.

5. The sealing resin sheet according to claim 1, wherein a mass ratio of the amount of the layer silicate compound to the total amount of the layer silicate compound and the 1 st inorganic filler in the 1 st sealing resin layer is 0.01 or more and 0.1 or less.

6. The sealing resin sheet according to claim 1, wherein the content ratio of the inorganic filler in the 1 st sealing resin layer is 83 mass% or more.

7. The sealing resin sheet according to claim 1, wherein the content ratio of the inorganic filler in the 1 st sealing resin layer is 90% by mass or less.

8. The sealing resin sheet according to any one of claims 1 to 7, wherein the following entry length L shown in the entry length evaluation test for carrying out the following 1 st step to 4 th step is 0 μm or more and 50 μm or less,

in the entry length evaluation test described above,

step 1: preparing a dummy chip mounting substrate including a glass substrate and a dummy chip having a size of 1mm × 1mm × 200 μm in thickness, the dummy chip being bonded to the glass substrate via a bump in a state of facing the glass substrate with a gap therebetween, the gap having a length of 50 μm from the glass substrate to the dummy chip;

step 2: pressing the sealing resin sheet toward the glass substrate by vacuum platen pressing under conditions of a temperature of 70 ℃, a degree of vacuum of 1.6kPa or less, a pressure of 0.1MPa, and a pressing time of 40 seconds in a state where the 1 st sealing resin layer side of the sealing resin sheet is in contact with the dummy chip on the glass substrate, and closing an edge end of the void by the 1 st sealing resin layer adhering to the glass substrate around the dummy chip;

and 3, step 3: after the 2 nd step, curing the sealing resin sheet by heating at 150 ℃ for 1 hour under atmospheric pressure;

and 4, step 4: after the 3 rd step, the length L of the sealing resin sheet entering the void is measured.

9. An electronic component device, comprising:

a base material,

An electronic component chip mounted on the base material in a state of facing the base material with a gap therebetween, and

a cured resin part formed from the sealing resin sheet according to any one of claims 1 to 8 and sealing the electronic component chip and the void.

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