WO2023190236A1 - Composite et son procédé de production, et ensemble, substrat de circuit et module d'alimentation - Google Patents

Composite et son procédé de production, et ensemble, substrat de circuit et module d'alimentation Download PDF

Info

Publication number
WO2023190236A1
WO2023190236A1 PCT/JP2023/011984 JP2023011984W WO2023190236A1 WO 2023190236 A1 WO2023190236 A1 WO 2023190236A1 JP 2023011984 W JP2023011984 W JP 2023011984W WO 2023190236 A1 WO2023190236 A1 WO 2023190236A1
Authority
WO
WIPO (PCT)
Prior art keywords
composite
resin
sintered body
nitride sintered
nitride
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/JP2023/011984
Other languages
English (en)
Japanese (ja)
Inventor
翔二 岩切
紗緒梨 井之上
竜士 古賀
亮 吉松
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Denka Co Ltd
Original Assignee
Denka Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Denka Co Ltd filed Critical Denka Co Ltd
Publication of WO2023190236A1 publication Critical patent/WO2023190236A1/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B18/00—Layered products essentially comprising ceramics, e.g. refractory products
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/515—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics
    • C04B35/58—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics based on borides, nitrides, i.e. nitrides, oxynitrides, carbonitrides or oxycarbonitrides or silicides
    • C04B35/581—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics based on borides, nitrides, i.e. nitrides, oxynitrides, carbonitrides or oxycarbonitrides or silicides based on aluminium nitride
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/515—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics
    • C04B35/58—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics based on borides, nitrides, i.e. nitrides, oxynitrides, carbonitrides or oxycarbonitrides or silicides
    • C04B35/583—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics based on borides, nitrides, i.e. nitrides, oxynitrides, carbonitrides or oxycarbonitrides or silicides based on boron nitride
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B38/00—Porous mortars, concrete, artificial stone or ceramic ware; Preparation thereof
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K1/00—Printed circuits
    • H05K1/02—Details
    • H05K1/03—Use of materials for the substrate
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10W—GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10
    • H10W40/00—Arrangements for thermal protection or thermal control
    • H10W40/10—Arrangements for heating

Definitions

  • One aspect of the present disclosure relates to a composite body, a method for manufacturing the same, a joined body, a circuit board, and a power module.
  • Components such as power devices, transistors, thyristors, and CPUs are required to efficiently dissipate heat generated during use.
  • conventional efforts have been made to improve the thermal conductivity of the insulating layer of printed wiring boards on which electronic components are mounted, or to connect electronic components or printed wiring boards to electrically insulating thermal interface materials. It has been done by attaching it to a heat sink.
  • Composites made of resin and ceramics such as boron nitride are used for such insulating layers and thermal interface materials.
  • Patent Document 1 proposes a composite in which a sintered body of nitride-based ceramic is impregnated with a thermosetting resin composition in an incompletely cured state (B stage).
  • Composites made by impregnating a porous ceramic sintered body with resin have excellent adhesion to adherends and insulation properties, but have lower strength than ordinary ceramic sintered bodies, and are less reliable against heat cycles. is also not enough.
  • the present disclosure provides a composite that has high strength and excellent heat cycle resistance when joined to a metal member, and a method for manufacturing the same. Furthermore, the present disclosure provides a bonded body, a circuit board, and a power module with excellent reliability by including such a ceramic sintered body.
  • One aspect of the present disclosure is a composite body containing a nitride sintered body and a resin, wherein at least a portion of the resin is filled in the pores of the nitride sintered body, and the nitride sintered body is nitrided.
  • the above composite has high strength because it includes a nitride sintered body that contains boron nitride and aluminum nitride and has a porosity of less than 30% by volume. Furthermore, since the composite contains a resin and a nitride sintered body containing boron nitride and aluminum nitride, it has a coefficient of thermal expansion closer to that of metal than the boron nitride sintered body and the aluminum nitride sintered body. Therefore, it has excellent heat cycle resistance when bonded to a metal member. Furthermore, since it contains aluminum nitride, it also has excellent thermal conductivity.
  • the ratio of boron nitride to the total of boron nitride and aluminum nitride may be 10 to 90% by mass. This makes it possible to sufficiently increase the strength and thermal conductivity.
  • the ratio of pores impregnated with resin (resin filling rate) to the entire pores of the nitride sintered body may be 60% by volume or more. Such composites have sufficiently good electrical insulation properties.
  • the porosity of the nitride sintered body in the above composite may be 10% by volume or more. Such a composite has excellent adhesion to metals and the like.
  • the thickness of the composite may be 2 mm or less.
  • a composite body having such a thickness has excellent thermal conductivity, and thus can be suitably used for circuit boards and power modules.
  • One aspect of the present disclosure provides a joined body comprising any of the above-described composite bodies and a metal sheet joined to the composite body.
  • This joined body has excellent heat cycle resistance because any of the above-mentioned composite bodies and a metal sheet are joined together. Therefore, this joined body has excellent reliability.
  • One aspect of the present disclosure provides a circuit board including any of the above-described composite bodies and a conductor portion joined to the composite body.
  • This circuit board has excellent heat cycle resistance because any one of the above-mentioned composites and the conductor portion are bonded to each other. Therefore, this circuit board has excellent reliability.
  • One aspect of the present disclosure provides a power module including the circuit board described above and a semiconductor element electrically connected to a conductor portion of the circuit board.
  • This power module includes a circuit board to which the composite body and the conductor portion are bonded.
  • This power module has excellent reliability because it includes a circuit board having a composite body with excellent heat cycle resistance.
  • One aspect of the present disclosure provides a firing step of firing a raw material containing boron nitride and aluminum nitride to obtain a nitride sintered body having a porosity of less than 30% by volume, and at least one of the pores in the nitride sintered body.
  • a method for manufacturing a composite is provided.
  • the composite obtained by the above manufacturing method has high strength because it includes a nitride sintered body that contains boron nitride and aluminum nitride and has a porosity of less than 30% by volume. Furthermore, since the composite includes a resin and a nitride sintered body containing boron nitride and aluminum nitride, it has a coefficient of thermal expansion closer to that of metal than the boron nitride sintered body and the aluminum nitride sintered body. Therefore, it has excellent heat cycle resistance when bonded to a metal member. Furthermore, since the composite contains aluminum nitride, it also has excellent thermal conductivity.
  • FIG. 3 is a perspective view of the complex.
  • FIG. 3 is a cross-sectional view of the joined body. It is a sectional view of a power module.
  • a composite according to one embodiment contains a nitride sintered body and a resin.
  • the nitride sintered body has pores and may be porous. Pores include those filled with resin and those not filled with resin. That is, pores filled with resin are also referred to as "pores" in this specification. At least a portion of the resin contained in the composite fills the pores of the nitride sintered body.
  • the resin filling the pores may be either a semi-cured product (B stage) or a cured product (C stage).
  • the nitride sintered body contains boron nitride and aluminum nitride.
  • the total content of boron nitride and aluminum nitride in the nitride sintered body may be 90% by mass or more, 95% by mass or more, or 98% by mass or more.
  • the ratio of boron nitride to the total of boron nitride and aluminum nitride may be 10% by mass or more, 15% by mass or more, or 20% by mass or more. This makes it possible to ensure sufficient pores in the nitride sintered body to facilitate impregnation with the resin.
  • the ratio of boron nitride to the total of boron nitride and aluminum nitride may be 90% by mass or less, may be 85% by mass or less, and may be 80% by mass or less. This makes it possible to sufficiently increase the strength and thermal conductivity of the composite.
  • An example of the ratio of boron nitride to the total of boron nitride and aluminum nitride is 10 to 90% by mass.
  • the porosity of the nitride sintered body is less than 30% by volume, may be less than 25% by volume, and may be less than 22% by volume. This makes it possible to sufficiently increase the strength and heat cycle resistance of the composite.
  • the porosity of the nitride sintered body may be 10 volume% or more, 15 volume% or more, or 18 volume% or more. This allows the electrical insulation to be further improved.
  • the resin is a semi-cured material, it is possible to sufficiently increase the amount of resin that oozes out when the composite is bonded to another member.
  • An example of the porosity of the nitride sintered body is 10% by volume or more and less than 30% by volume.
  • the porosity is determined by calculating the bulk density B 0 (kg/m 3 ) from the volume and mass of the nitride sintered body, and using this bulk density and the theoretical density E 0 (kg/m 3 ) of the nitride, as follows: It can be determined using equation (1).
  • the theoretical density of boron nitride is 2280 kg/m 3 and the theoretical density of aluminum nitride is 3260 kg/m 3 .
  • the theoretical density E 0 (kg/m 3 ) can be calculated according to the ratio of boron nitride and aluminum nitride.
  • Porosity (volume %) [1-(B 0 /E 0 )] x 100 (1)
  • the bulk density B 0 of the nitride sintered body may be 1400 to 2800 kg/m 3 , or 1600 to 2500 kg/m 3 .
  • a nitride sintered body having such a bulk density of B0 has high strength and excellent heat cycle resistance, and has a sufficiently high resin filling rate to improve adhesion to other members (metallic members). Electrical insulation can be made sufficiently high.
  • the ratio of pores impregnated with resin (resin filling rate) to the entire pores of the nitride sintered body may be 60 volume% or more, 70 volume% or more, 75 volume% or more. It's okay.
  • resin filling rate By increasing the resin filling rate in this way, electrical insulation can be made sufficiently high.
  • the amount of resin that seeps from the inside of the composite to the surface increases when the composite and another member are pressed together.
  • Such a composite has excellent adhesiveness to other members (metal members).
  • the ratio of pores impregnated with resin to the entire pores of the nitride sintered body may be 95% by volume or less, and may be 90% by volume or less.
  • the ratio of pores impregnated with resin to the total pores of the nitride sintered body may be, for example, 60 to 95% by volume.
  • the resin contained in the pores of the nitride sintered body in the composite is a cured product (C stage) or semi-cured product (B stage) of a resin composition containing a main resin and a curing agent.
  • the cured product is one in which the curing reaction of the resin composition has completely progressed.
  • the semi-cured product is one in which the curing reaction of the resin composition has partially progressed.
  • the semi-cured material can be further cured by a subsequent curing treatment.
  • a bonded body may be obtained by temporarily press-bonding it with another member such as a metal sheet by utilizing the semi-cured state, and then heating it.
  • the resin may include a thermosetting resin produced by the reaction of the main resin and the curing agent in the resin composition.
  • the semi-cured material may contain monomers such as a base resin and a curing agent in addition to the thermosetting resin as a resin component. It can be confirmed, for example, by a differential scanning calorimeter that the resin contained in the composite is a semi-cured product (B stage) before becoming a cured product (C stage).
  • Resins include epoxy resin, silicone resin, cyanate resin, silicone rubber, acrylic resin, phenol resin, melamine resin, urea resin, bismaleimide resin, unsaturated polyester, fluororesin, polyimide, polyamideimide, polyetherimide, polybutylene terephthalate.
  • polyethylene terephthalate polyphenylene ether, polyphenylene sulfide, fully aromatic polyester, polysulfone, liquid crystal polymer, polyether sulfone, polycarbonate, maleimide resin, maleimide modified resin, ABS (acrylonitrile-butadiene-styrene) resin, AAS (acrylonitrile-acrylic rubber) styrene) resin, AES (acrylonitrile-ethylene-propylene-diene rubber-styrene) resin, polyglycolic acid resin, polyphthalamide, and polyacetal.
  • One type of these may be included alone, or two or more types may be included in combination.
  • the resin may contain an epoxy resin from the viewpoint of heat resistance and improvement of adhesive strength with a circuit.
  • the resin may include a silicone resin from the viewpoint of improving heat resistance, flexibility, and adhesion to a heat sink and the like.
  • the mass proportion of the resin in the composite may be 16 to 26% by mass based on the total mass of the composite.
  • a composite containing resin at such a mass ratio can achieve both excellent adhesiveness, strength, and heat cycle resistance at a high level.
  • the shape of the composite is not particularly limited, and may be in the form of a sheet (composite sheet), for example. It may be block-shaped. If it is in the form of a sheet, it can be suitably used as a heat dissipation member because it has excellent thermal conductivity in the thickness direction.
  • the thickness t of the composite body 10 may be, for example, less than 5 mm, less than 2 mm, or less than 1 mm.
  • the lower limit of the thickness t of the composite 10 may be 0.1 mm.
  • the composite body 10 can be sufficiently reduced in size and weight.
  • Such a composite body 10 is suitably used as a component of a power module, for example.
  • the thickness of the composite body 10 is measured along the direction perpendicular to the main surfaces 10a and 10b. When the thickness of the composite body 10 is not constant, the thickness may be measured by selecting ten arbitrary locations, and the average value thereof may be within the above-mentioned range.
  • the sizes of the main surfaces 10a and 10b of the composite 10 are not particularly limited.
  • the area of the main surfaces 10a and 10b of the composite body 10 may be, for example, 50 mm 2 or more, 200 mm 2 or more, or 1000 mm 2 or more.
  • the composite body 10 may be made into a joined body by joining metal sheets, or may be used as a heat dissipating member as it is.
  • a composite body and a metal sheet are joined to each other.
  • the complex may be one exemplified above.
  • the metal sheet is not particularly limited as long as it is made of metal and has a sheet shape.
  • the metal sheet may be a metal plate or a metal foil.
  • the other members (adherends) mentioned in the above description of the composite may be metal sheets. Examples of the material of the metal sheet include aluminum and copper.
  • FIG. 2 is a cross-sectional view showing an example of a joined body.
  • FIG. 2 shows a cross section of the joined body 100 taken along the stacking direction.
  • the joined body 100 includes the composite body 10 of FIG. 1, a metal sheet 20A joined onto the main surface 10a of the composite body 10, and a metal sheet 20B joined onto the main surface 10b.
  • the material and thickness of the metal sheets 20A and 20B may be the same or different.
  • the size of the metal sheet is not limited to what is illustrated. It is not essential to provide metal sheets on both major surfaces of the composite 10. In a modification, only one main surface of the composite 10 may be provided with a metal sheet.
  • the metal sheets 20A and 20B in the joined body 100 are in contact with the main surfaces 10a and 10b of the composite body 10, respectively. If the resin contained in the pores of the nitride sintered body of the composite body 10 is semi-hardened, when the metal sheets 20A, 20B and the composite body 10 are pressed together and heated, the resin seeped out from the pores will cause the metal sheet to harden. 20A, 20B and composite body 10 are firmly adhered. Since the metal sheets 20A, 20B and the composite body 10 are bonded to each other with high adhesion, the joined body 100 can be suitably used, for example, as a heat dissipation member in a power module or the like.
  • the thickness of the joined body 100 may be, for example, less than 12 mm, less than 6 mm, or less than 3 mm.
  • the lower limit of the thickness of the joined body 100 may be 0.6 mm.
  • the joined body 100 can be sufficiently reduced in size and weight.
  • Such a joined body 100 is suitably used as a circuit board of a power module, for example.
  • An example of the thickness of the joined body 100 may be 0.6 mm or more and less than 12 mm.
  • the joined body 100 includes the composite body 10, it has high strength and excellent heat cycle resistance.
  • a ceramic sintered body and a metal plate are joined together, large thermal stress is generated in the vicinity of the joint surface due to the difference in coefficient of thermal expansion between the two.
  • the nitride sintered body contained in the composite body 10 contains boron nitride and aluminum nitride, the thermal stress generated in the peripheral region 40 of the joint surface between the composite body 10 and the metal sheets 20A and 20B can be reduced. can be sufficiently reduced. This can suppress the occurrence of cracks in the peripheral region 40.
  • the joined body 100 has excellent reliability.
  • a power module includes a circuit board and a semiconductor element electrically connected to a conductor portion of the circuit board.
  • the circuit board may be one in which a conductor portion is joined to the above-described composite body or a modified example thereof.
  • the circuit board may be obtained by subjecting the above-described joined body 100 or a modification thereof to processing such as etching.
  • processing such as etching.
  • Such a power module has excellent reliability because it includes a composite body with excellent heat cycle resistance.
  • FIG. 3 is a cross-sectional view showing an example of a power module.
  • the power module 200 includes a base plate 70 and a circuit board 101 joined to one side of the base plate 70 via solder 62.
  • the metal sheet 21 on one side of the circuit board 101 is joined to the base plate 70 via solder 62.
  • a semiconductor element 60 is attached to at least one of the metal sheets 20 on the other side of the circuit board 101 via solder 61.
  • the semiconductor element 60 is connected to a predetermined location of the metal sheet 20 with a metal wire 64 such as an aluminum wire. In this way, the semiconductor element 60 and the metal sheet 20 are electrically connected.
  • the metal sheet 20a which is one of the metal sheets 20, is connected to an electrode 63 provided through the casing 66 via a solder 65. ing.
  • a housing 66 is disposed on one main surface of the base plate 70 and is integrated with the main surface to accommodate the circuit board 101.
  • a housing space formed by one main surface of the base plate 70 and the housing 66 is filled with resin 80 so as to cover the circuit board 101 and the semiconductor element 60 .
  • the resin 80 seals the circuit board 101 and the semiconductor element 60.
  • the resin may be, for example, a thermosetting resin or a photocurable resin. This resin may be the same as the resin contained in composite 10, or may be different.
  • Cooling fins 72 forming a heat radiating section are joined to the other main surface of the base plate 70 via grease 74. Screws 73 are attached to the ends of the base plate 70 to fix the cooling fins 72 to the base plate 70.
  • the base plate 70 and the cooling fins 72 may be made of aluminum.
  • the base plate 70 and the cooling fins 72 have high thermal conductivity and function well as a heat dissipation section.
  • the metal sheet 20 and the metal sheet 21 are electrically insulated by the composite body 10.
  • the metal sheet 20 (20a) may constitute an electric circuit as a conductor portion.
  • the metal sheet 20 and the metal sheet 21 are joined to the main surface 10a and the main surface 10b of the composite body 10, respectively, by the resin exuded from the composite body 10. Therefore, the metal sheets 20, 21 and the composite body 10 are in close contact with each other, and the reliability is excellent. Further, compared to the case where bonding is performed using a brazing material or the like, the process can be simplified and the circuit board 101 can be made thinner. Moreover, thermal conductivity can also be increased.
  • a method for manufacturing a composite includes a firing step of firing a raw material containing boron nitride and aluminum nitride to obtain a nitride sintered body having a porosity of less than 30% by volume; an impregnation step of impregnating at least some of the pores with a resin composition to obtain a resin-impregnated body; and a curing step of heating the resin-impregnated body and curing or semi-curing the resin composition impregnated into the pores to obtain a composite. and has.
  • the boron nitride may include one or both of amorphous boron nitride and hexagonal boron nitride.
  • boron nitride powder and aluminum nitride powder having an average particle size of 0.5 to 20.0 ⁇ m, for example, can be used.
  • the average particle size in this specification is the median diameter (D50) at which the cumulative frequency is 50% in the volume-based particle size distribution measured by laser diffraction/scattering method.
  • a raw material powder containing boron nitride powder and aluminum nitride powder in a predetermined ratio is molded and sintered to obtain a nitride sintered body.
  • the molding may be performed by uniaxial pressure using a mold, or by cold isostatic pressing (CIP).
  • a sintering aid may be added to the raw material powder before molding.
  • a spheroidization process may be performed in which a binder is blended, heated and stirred, and then sprayed with a spray dryer.
  • the sintering aid examples include metal oxides such as yttrium oxide, aluminum oxide and magnesium oxide, alkali metal carbonates such as lithium carbonate and sodium carbonate, and boric acid.
  • the blending amount of the sintering aid is, for example, 2 parts by mass or more based on a total of 100 parts by mass of boron nitride powder and aluminum nitride powder, from the viewpoint of reducing porosity. The amount may be 3 parts by mass or more.
  • the porosity of the nitride sintered body can be adjusted by adjusting the amount of the sintering aid.
  • the blending amount of the sintering aid may be, for example, 20 parts by mass or less, and 10 parts by mass or less, based on a total of 100 parts by mass of the boron nitride powder and the aluminum nitride powder, from the viewpoint of sufficiently increasing the bending strength. It may be.
  • the molding pressure may be, for example, 20 to 350 MPa.
  • the shape of the molded body may be a sheet having a thickness of less than 2 mm or less than 1 mm. If a nitride sintered body is produced using such a sheet-shaped compact, a sheet-shaped composite with a thickness of less than 2 mm or less than 1 mm can be produced without cutting the nitride sintered body. can. Further, compared to the case where a block-shaped nitride sintered body is cut into a sheet shape, material loss due to processing can be reduced by forming the sheet shape from the stage of a compact. Therefore, the composite can be manufactured with high yield.
  • the firing temperature may be, for example, 1800 to 1900°C.
  • the sintering time may be, for example, 3 to 10 hours.
  • the atmosphere during firing may be, for example, an inert gas atmosphere such as nitrogen, helium, and argon.
  • a batch type furnace, a continuous type furnace, etc. can be used for firing.
  • batch furnaces include muffle furnaces, tube furnaces, and atmospheric furnaces.
  • continuous furnaces include rotary kilns, screw conveyor furnaces, tunnel furnaces, belt furnaces, pusher furnaces, and large continuous furnaces. In this way, a nitride sintered body can be obtained.
  • a cutting process may be performed to process it to a thickness of less than 2 mm or less than 1 mm.
  • the nitride sintered body is cut using, for example, a wire saw.
  • the wire saw may be, for example, a multi-cut wire saw.
  • the pores of the nitride sintered body are impregnated with a resin composition having a viscosity of 10 to 800 mPa ⁇ s to obtain a resin-impregnated body.
  • a resin composition having a viscosity of 10 to 800 mPa ⁇ s By reducing the thickness of the nitride sintered body, the resin composition can be impregnated smoothly. Furthermore, by setting the viscosity of the resin composition in a range suitable for impregnation, it is possible to sufficiently increase the filling rate of the resin filler and reduce variations in filling.
  • the viscosity of the resin composition when impregnating the nitride sintered body with the resin composition may be 700 mPa ⁇ s or less, 600 mPa ⁇ s or less, or 550 mPa ⁇ s or less. By lowering the viscosity of the resin composition in this manner, impregnation of the resin composition can be sufficiently promoted.
  • the viscosity of the resin composition when impregnating the nitride sintered body with the resin composition may be 15 mPa ⁇ s or more, 50 mPa ⁇ s or more, or 100 mPa ⁇ s or more.
  • the viscosity of the resin composition may be adjusted by partially polymerizing the monomer components.
  • the above viscosity of the resin composition is the viscosity at the temperature (T1) of the resin composition when impregnating the nitride sintered body with the resin composition. This viscosity is measured using a rotational viscometer at a shear rate of 10 (1/sec) and at a temperature (T1). Therefore, by changing the temperature T1, the viscosity when impregnating the nitride sintered body with the resin composition may be adjusted.
  • the temperature (T2) may be, for example, 80 to 140°C.
  • the resin composition may be impregnated into the nitride sintered body under pressure or under reduced pressure.
  • the impregnation method is not particularly limited, and the nitride sintered body may be immersed in the resin composition, or the resin composition may be applied to the surface of the nitride sintered body.
  • the impregnation step may be carried out under reduced pressure conditions or pressurized conditions, or may be carried out in combination with impregnation under reduced pressure conditions and impregnation under pressurized conditions.
  • the pressure within the impregnating device when performing the impregnation step under reduced pressure conditions may be, for example, 1000 Pa or less, 500 Pa or less, 100 Pa or less, 50 Pa or less, or 20 Pa or less.
  • the pressure within the impregnation device when the impregnation step is carried out under pressurized conditions may be, for example, 1 MPa or more, 3 MPa or more, 10 MPa or more, or 30 MPa or more.
  • the average pore diameter of the nitride sintered body may be 0.5 to 5 ⁇ m, or 1 to 4 ⁇ m.
  • the resin composition for example, one that becomes the resin mentioned in the description of the above-mentioned composite by a curing or semi-curing reaction can be used.
  • the resin composition may contain a solvent.
  • the viscosity of the resin composition may be adjusted by changing the blending amount of the solvent, or the viscosity of the resin composition may be adjusted by partially allowing the curing reaction to proceed.
  • the solvent examples include aliphatic alcohols such as ethanol and isopropanol, 2-methoxyethanol, 1-methoxyethanol, 2-ethoxyethanol, 1-ethoxy-2-propanol, 2-butoxyethanol, 2-(2-methoxyethoxy ) Ether alcohols such as ethanol, 2-(2-ethoxyethoxy)ethanol, 2-(2-butoxyethoxy)ethanol, glycol ethers such as ethylene glycol monomethyl ether, ethylene glycol monobutyl ether, acetone, methyl ethyl ketone, methyl isobutyl ketone, diisobutyl Examples include ketones such as ketones, and hydrocarbons such as toluene and xylene. One type of these may be included alone, or two or more types may be included in combination.
  • the resin composition is thermosetting and contains, for example, at least one selected from the group consisting of a compound having a cyanate group, a compound having a bismaleimide group, and a compound having an epoxy group, and a curing agent. It's fine.
  • Examples of compounds having a cyanate group include dimethylmethylenebis(1,4-phenylene)biscyanato and bis(4-cyanatophenyl)methane.
  • Dimethylmethylenebis(1,4-phenylene)biscyanate is commercially available, for example, as TACN (manufactured by Mitsubishi Gas Chemical Co., Ltd., trade name).
  • Examples of compounds having a bismaleimide group include N,N'-[(1-methylethylidene)bis[(p-phenylene)oxy(p-phenylene)]]bismaleimide, and 4,4'-diphenylmethane bismaleimide. etc.
  • N,N'-[(1-methylethylidene)bis[(p-phenylene)oxy(p-phenylene)]]bismaleimide is, for example, commercially available as BMI-80 (manufactured by K.I. Kasei Co., Ltd., trade name). available.
  • Examples of the compound having an epoxy group include bisphenol F type epoxy resin, bisphenol A type epoxy resin, biphenyl type epoxy resin, and polyfunctional epoxy resin.
  • bisphenol F type epoxy resin bisphenol A type epoxy resin
  • biphenyl type epoxy resin biphenyl type epoxy resin
  • polyfunctional epoxy resin 1,6-bis(2,3-epoxypropan-1-yloxy)naphthalene, which is commercially available as HP-4032D (manufactured by DIC Corporation, trade name), may be used.
  • the curing agent may contain a phosphine-based curing agent and an imidazole-based curing agent.
  • the phosphine curing agent can promote the triazine production reaction by trimerization of a compound having a cyanate group or a cyanate resin.
  • Examples of the phosphine curing agent include tetraphenylphosphonium tetra-p-tolylborate and tetraphenylphosphonium tetraphenylborate. Tetraphenylphosphonium tetra-p-tolylborate is commercially available, for example, as TPP-MK (manufactured by Hokuko Chemical Industry Co., Ltd., trade name).
  • the imidazole curing agent generates oxazoline and accelerates the curing reaction of a compound having an epoxy group or an epoxy resin.
  • Examples of the imidazole curing agent include 1-(1-cyanomethyl)-2-ethyl-4-methyl-1H-imidazole and 2-ethyl-4-methylimidazole.
  • 1-(1-cyanomethyl)-2-ethyl-4-methyl-1H-imidazole is commercially available, for example, as 2E4MZ-CN (manufactured by Shikoku Kasei Kogyo Co., Ltd., trade name).
  • the content of the phosphine curing agent is, for example, 5 parts by mass or less, 4 parts by mass or less, or 3 parts by mass or less, based on 100 parts by mass of the total amount of the compound having a cyanate group, the compound having a bismaleimide group, and the compound having an epoxy group. It may be less than parts by mass.
  • the content of the phosphine curing agent is, for example, 0.1 parts by mass or more or 0.5 parts by mass with respect to 100 parts by mass of the total amount of the compound having a cyanate group, the compound having a bismaleimide group, and the compound having an epoxy group. It may be more than 100 yen. When the content of the phosphine curing agent is within the above range, the resin-impregnated body can be easily prepared.
  • the content of the imidazole curing agent is, for example, 0.1 part by mass or less, 0.05 part by mass with respect to 100 parts by mass of the total amount of the compound having a cyanate group, the compound having a bismaleimide group, and the compound having an epoxy group. part or less or 0.03 part by mass or less.
  • the content of the imidazole curing agent is, for example, 0.001 parts by mass or more or 0.005 parts by mass with respect to 100 parts by mass of the total amount of the compound having a cyanate group, the compound having a bismaleimide group, and the compound having an epoxy group. It may be more than 100 yen. When the content of the imidazole curing agent is within the above range, the resin-impregnated body can be easily prepared.
  • the resin composition may contain components other than the base resin and curing agent.
  • Other components include, for example, other resins such as phenolic resins, melamine resins, urea resins, and alkyd resins, silane coupling agents, leveling agents, antifoaming agents, surface conditioning agents, wetting and dispersing agents, etc. But that's fine.
  • the content of these other components may be, for example, 20% by mass or less, 10% by mass or less, or 5% by mass or less, based on the total amount of the resin composition.
  • a curing step may be performed after the impregnation step.
  • the resin composition contained in the resin-impregnated body is cured or semi-cured to obtain a resin-containing composite.
  • the resin composition is cured or semi-cured by heating and/or light irradiation depending on the type of the resin composition (or a curing agent added as needed).
  • the heating temperature when curing or semi-curing the resin composition by heating may be, for example, 80 to 180°C.
  • the resin obtained by semi-curing or curing the resin composition contains at least one thermosetting resin selected from the group consisting of cyanate resin, bismaleimide resin and epoxy resin, and a curing agent as a resin component. good.
  • the resin may also contain other resins, such as phenolic resins, melamine resins, urea resins, and alkyd resins, as well as silane coupling agents, leveling agents, antifoaming agents, surface conditioning agents, and wetting agents. It may also contain components derived from dispersants and the like.
  • At least some of the pores of the nitride sintered body included in the composite obtained by the above manufacturing method are filled with resin.
  • the structure, shape, composition, etc. of the composite are as described in the embodiment of the composite. This composite has high strength and excellent heat cycle resistance.
  • a method for manufacturing a bonded body includes a bonding step of laminating a composite body manufactured by any of the above-mentioned manufacturing methods and a metal sheet, and heating and pressurizing the composite body and metal sheet.
  • the metal sheet may be a metal plate or a metal foil.
  • a metal sheet is placed on the main surface of the composite. With the main surfaces of the composite and the metal sheet in contact with each other, pressure is applied in a direction in which the main surfaces face each other, and the metal sheet is heated. As a result, the resin oozes out from the pores and hardens, allowing the composite and the metal sheet to be joined. At this time, it is not necessary to apply pressure and heat at the same time, and heating may be performed after pressurizing and crimping.
  • the thus obtained bonded body is small, lightweight, and has excellent heat cycle resistance. Therefore, it is suitable for use as a circuit board mounted on a power module.
  • the circuit board may be manufactured by etching the bonded body to form a conductor portion having a predetermined pattern.
  • a power module may be manufactured using the circuit board obtained in this way.
  • a power module can be manufactured by mounting a semiconductor element on a circuit board using solder and wire bonding, etc., housing the circuit board and semiconductor element in a housing space of a housing, and then sealing it with resin. .
  • the present disclosure is not limited to the above embodiments.
  • the circuit board may be used for semiconductor devices other than power modules.
  • the nitride sintered body may be obtained by hot pressing in which molding and firing are performed simultaneously.
  • the nitride sintered body contains boron nitride and aluminum nitride
  • [3] The composite according to [1] or [2], wherein the ratio of the pores impregnated with the resin to the entire pores of the nitride sintered body is 60% by volume or more.
  • [4] The composite according to any one of [1] to [3], wherein the porosity of the nitride sintered body is 10% by volume or more.
  • [5] The composite according to any one of [1] to [4], which has a thickness of less than 2 mm.
  • a joined body comprising the composite according to any one of [1] to [5] above and a metal sheet joined to the composite.
  • a circuit board comprising the composite body according to any one of [1] to [5] above, and a conductor portion joined to the composite body.
  • a power module comprising the circuit board according to [7] above, and a semiconductor element electrically connected to the conductor portion of the circuit board.
  • a method for manufacturing a composite body comprising a curing step of heating the resin-impregnated body and curing or semi-curing the resin composition impregnated into the pores to obtain a composite body.
  • Example 1 ⁇ Preparation of nitride sintered body> A raw material powder was prepared by blending hexagonal boron nitride powder (average particle size: 10.0 ⁇ m) and aluminum nitride powder (average particle size: 1.0 ⁇ m) at a mass ratio of 25:75.
  • a sintering aid was prepared by blending powdered yttrium oxide. 5 parts by mass of a sintering aid and 10 parts by mass of a binder (polyvinyl alcohol ("GOHSENOL", manufactured by Nippon Gosei Kagaku Kogyo Co., Ltd.)) were mixed with 100 parts by mass of the raw material powder. The obtained mixture was heated and stirred at 50° C. until dissolved, and then subjected to spheroidization treatment at a drying temperature of 230° C. using a spray dryer. In this way, a spheroidized mixed powder was prepared. Note that a rotary atomizer was used as the spheroidizing device of the spray dryer.
  • the above mixed powder was filled into a cold isostatic pressing (CIP) device (manufactured by Kobe Steel, Ltd., trade name: ADW800) and compressed at a pressure of 30 MPa to produce a molded body.
  • CIP cold isostatic pressing
  • the produced molded body was sintered by holding it in a temperature range of 1800 to 1900° C. for 5 hours using a batch type high frequency furnace (manufactured by Fuji Denpa Kogyo Co., Ltd., product name: FTH-300-1H).
  • a porous nitride sintered body thickness: 0.4 mm having a sheet shape was obtained.
  • the firing was performed by adjusting the inside of the furnace to a nitrogen atmosphere while flowing nitrogen into the furnace at a standard flow rate of 10 L/min.
  • Table 1 shows the respective mass ratios based on the total of boron nitride and aluminum nitride, and the theoretical density E 0 calculated based on the mass ratios.
  • the volume and mass of the obtained nitride sintered body were measured, and the bulk density B 0 (kg/m 3 ) was calculated from the volume and mass.
  • the bulk density B0 of the nitride sintered body is determined by the length of each side of the nitride sintered body (measured with a caliper) in accordance with JIS Z 8807:2012 "method for measuring density and specific gravity by geometric measurement”. ) and the mass of the nitride sintered body measured with an electronic balance (see JIS Z 8807:2012, item 9).
  • a resin composition was prepared. The prepared resin composition was heated at 120°C for 15 minutes. While maintaining the temperature of the resin composition at 100° C., the resin composition was dropped onto the upper main surface of the nitride sintered body using a dispenser to impregnate the nitride sintered body.
  • the viscosity of the resin composition at this time was 500 mPa ⁇ s.
  • the amount of the resin composition dropped was 1.5 times the total volume of the pores of the nitride sintered body. A part of the resin composition did not impregnate the nitride sintered body and remained on the main surface.
  • the resin composition remaining on the upper main surface of the nitride sintered body was smoothed using a stainless steel scraper (manufactured by Narubi Co., Ltd.). The excess resin composition was removed to obtain a resin-impregnated body with a smooth main surface.
  • the resin filling rate S in the pores of the composite was determined by the following formula (2).
  • the bulk density B1 of the composite was determined by the same procedure as the bulk density B0 of the nitride sintered body.
  • Resin filling rate S (volume %) ((Bulk density of composite B 1 - Bulk density of nitride sintered body B 0 )/(Theoretical density of composite E 1 - Bulk density of nitride sintered body B 0 )) ⁇ 100...(2)
  • the theoretical density E1 of the composite was determined from the following formula (3).
  • Theoretical density of the composite E 1 true density of nitride sintered body + true density of resin ⁇ (1-bulk density of nitride sintered body B 0 / true density of nitride sintered body) ... (3 )
  • the true density of the boron nitride sintered body and resin is the volume of the nitride sintered body and resin measured using a dry automatic density meter in accordance with the density and specific gravity measurement method by gas displacement method of JIS Z 8807:2012. and the mass (see equations (14) to (17) in section 11 of JIS Z 8807:2012)
  • H thermal conductivity (W/(m ⁇ K))
  • A thermal diffusivity (m 2 /sec)
  • B 1 bulk density (kg/m 3 )
  • C ratio Indicates heat capacity (J/(kg ⁇ K)).
  • a xenon flash analyzer manufactured by NETZSCH, trade name: LFA447NanoFlash
  • the specific heat capacity C was measured using a differential scanning calorimeter (manufactured by Rigaku Co., Ltd., device name: ThermoPlusEvo DSC8230).
  • the thermal conductivity H is shown in Table 2.
  • Example 2 A raw material powder was prepared by blending the hexagonal boron nitride powder and aluminum nitride powder used in Example 1 at a mass ratio of 50:50. A nitride sintered body, a composite body, a bonded body, and a circuit board were produced and evaluated in the same manner as in Example 1 except that this raw material powder was used. The results were as shown in Tables 1 and 2.
  • Example 3 A raw material powder was prepared by blending the hexagonal boron nitride powder and aluminum nitride powder used in Example 1 at a mass ratio of 75:25. A nitride sintered body, a composite body, a bonded body, and a circuit board were produced and evaluated in the same manner as in Example 1 except that this raw material powder was used. The results were as shown in Tables 1 and 2.
  • Example 1 A nitride sintered body, a composite, a bonded body, and a circuit board were produced and evaluated in the same manner as in Example 1, except that the hexagonal boron nitride powder used in Example 1 was used as the raw material powder. . The results were as shown in Tables 1 and 2.
  • Example 2 A nitride sintered body, a composite, a bonded body, and a circuit board were produced and evaluated in the same manner as in Example 1, except that the aluminum nitride powder used in Example 1 was used as the raw material powder. The results were as shown in Tables 1 and 2.
  • Example 3 A nitride sintered body was produced in the same manner as in Example 1, except that the CIP pressure during production of the compact was 10 MPa, and the nitride sintered body was evaluated. The results were as shown in Table 1.
  • Examples 1 to 3 were able to maintain bending strength and thermal conductivity within a high range, and had excellent heat cycle resistance.
  • the boron nitride sintered body of Comparative Example 1 was able to be filled with resin, it was inferior to Examples 1 to 3 in terms of bending strength, thermal conductivity, and reliability.
  • the aluminum nitride sintered body of Comparative Example 2 had progressed to densification and could not be filled with resin. For this reason, it could not be bonded to a copper plate, and a composite or a bonded body could not be produced.
  • the nitride sintered body of Comparative Example 3 had a high porosity and the bending strength was clearly lower than that of the nitride sintered body of Example 3, so a composite was not manufactured or evaluated.
  • a composite having high strength and excellent heat cycle resistance when bonded to metal, and a method for manufacturing the same are provided. According to the present disclosure, by including such a ceramic sintered body, a bonded body, a circuit board, and a power module with excellent reliability are provided.
  • SYMBOLS 10 Composite, 10a, 10b... Main surface, 20, 20a, 20A, 20B, 21... Metal sheet, 40... Peripheral area, 60... Semiconductor element, 61, 62, 65... Solder, 63... Electrode, 64... Metal Wire, 66... Housing, 70... Base plate, 72... Cooling fin, 73... Screw, 74... Grease, 80... Resin, 100... Joined body, 101... Circuit board, 200... Power module.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Ceramic Engineering (AREA)
  • Materials Engineering (AREA)
  • Structural Engineering (AREA)
  • Organic Chemistry (AREA)
  • Manufacturing & Machinery (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Ceramic Products (AREA)
  • Laminated Bodies (AREA)
  • Porous Artificial Stone Or Porous Ceramic Products (AREA)
  • Cooling Or The Like Of Semiconductors Or Solid State Devices (AREA)

Abstract

L'invention concerne un composite comprenant un corps fritté de nitrure et une résine. Les pores du corps fritté de nitrure sont remplis d'au moins une partie de la résine. Le corps fritté de nitrure contient du nitrure de bore et du nitrure d'aluminium. La porosité du corps fritté de nitrure est inférieure à 30 % en volume. L'invention concerne un procédé de production composite comprenant : une étape de cuisson pour cuire une matière première contenant du nitrure de bore et du nitrure d'aluminium pour obtenir un corps fritté de nitrure ayant une porosité inférieure à 30 % en volume ; une étape d'imprégnation pour imprégner au moins une partie des pores du corps fritté de nitrure avec une composition de résine pour obtenir un corps imprégné de résine ; et une étape de durcissement pour durcir ou semi-durcir la composition de résine imprégnant les pores par chauffage du corps imprégné de résine pour obtenir un composite.
PCT/JP2023/011984 2022-03-31 2023-03-24 Composite et son procédé de production, et ensemble, substrat de circuit et module d'alimentation Ceased WO2023190236A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2022-059513 2022-03-31
JP2022059513A JP2025085032A (ja) 2022-03-31 2022-03-31 複合体及びその製造方法、並びに、接合体、回路基板及びパワーモジュール

Publications (1)

Publication Number Publication Date
WO2023190236A1 true WO2023190236A1 (fr) 2023-10-05

Family

ID=88201678

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2023/011984 Ceased WO2023190236A1 (fr) 2022-03-31 2023-03-24 Composite et son procédé de production, et ensemble, substrat de circuit et module d'alimentation

Country Status (2)

Country Link
JP (1) JP2025085032A (fr)
WO (1) WO2023190236A1 (fr)

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2016111171A (ja) * 2014-12-05 2016-06-20 デンカ株式会社 セラミックス樹脂複合体回路基板及びそれを用いたパワー半導体モジュール
WO2019111978A1 (fr) * 2017-12-05 2019-06-13 デンカ株式会社 Corps composite de résine céramique de nitrure
WO2020203586A1 (fr) * 2019-03-29 2020-10-08 デンカ株式会社 Composite, procédé de production de composite, stratifié et procédé de production de stratifié
WO2021200973A1 (fr) * 2020-03-31 2021-10-07 デンカ株式会社 Procédé servant à produire un corps composite

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2016111171A (ja) * 2014-12-05 2016-06-20 デンカ株式会社 セラミックス樹脂複合体回路基板及びそれを用いたパワー半導体モジュール
WO2019111978A1 (fr) * 2017-12-05 2019-06-13 デンカ株式会社 Corps composite de résine céramique de nitrure
WO2020203586A1 (fr) * 2019-03-29 2020-10-08 デンカ株式会社 Composite, procédé de production de composite, stratifié et procédé de production de stratifié
WO2021200973A1 (fr) * 2020-03-31 2021-10-07 デンカ株式会社 Procédé servant à produire un corps composite

Also Published As

Publication number Publication date
JP2025085032A (ja) 2025-06-04

Similar Documents

Publication Publication Date Title
KR102306153B1 (ko) 세라믹 수지 복합체
TWI633813B (zh) Boron nitride-resin composite circuit substrate, boron nitride-resin composite heat release plate integrated circuit substrate
JP7145876B2 (ja) 窒化物系セラミックス樹脂複合体
JP7566727B2 (ja) 複合体、複合体の製造方法、積層体及び積層体の製造方法
WO2018181606A1 (fr) Élément thermoconducteur et structure de dissipation de chaleur comprenant ledit élément thermoconducteur
JP7550869B2 (ja) 複合体及びその製造方法、並びに、積層体及びその製造方法
JP7217391B1 (ja) 複合体及びその製造方法、並びに、積層体及びその製造方法
JP7248867B2 (ja) 複合体シート及び積層体
WO2023190236A1 (fr) Composite et son procédé de production, et ensemble, substrat de circuit et module d'alimentation
JP7458479B2 (ja) 複合体及び複合体の製造方法
JP7176159B2 (ja) 複合シート及びその製造方法、並びに、積層体及びその製造方法
JP7165844B2 (ja) 複合シート及びその製造方法、並びに、積層体及びその製造方法
JP7381806B2 (ja) 積層部品、及びその製造方法、並びに、積層体、及びその製造方法
JP7148758B1 (ja) 複合シート及びその製造方法、並びに、積層体及びその製造方法
JP7263634B1 (ja) 複合シート、及び複合シートの製造方法、並びに、積層基板
JP7196367B2 (ja) 複合シート及びその製造方法、積層体及びその製造方法、並びに、パワーデバイス
CN116034017A (zh) 复合片材、层叠体及对复合片材的粘接性进行推定的评价方法
JP2024055999A (ja) 回路基板の製造方法及び回路基板
JP2007335835A (ja) 配線板
CN116134005A (zh) 对复合体的粘接可靠性及散热性能进行评价的方法以及复合体
JP2006165353A (ja) 配線板

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 23780246

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 23780246

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: JP