JP2013023503A - Resin composition, resin sheet, laminate, metal-based circuit board, inverter and power semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin composition excellent in adhesion between a metal plate and an insulating layer, and excellent in heat cycle resistance, and having enough breakdown voltage, as well as to provide a resin sheet, a laminate, a metal-based circuit board, an inverter and a power semiconductor device.SOLUTION: This resin composition includes a phenoxy resin (A) having a specific structure, an inorganic filler (B) and a silane coupling agent (C), wherein the resin composition contains ≥1 mass% and ≤10 mass% of the silane coupling agent (C) relative to the total amount of the resin composition. The resin sheet, the laminate, the metal-based circuit board, the inverter and the power semiconductor device produced using an insulating layer made from the resin composition are also disclosed.

Description

  The present invention relates to a resin composition, a resin sheet, a laminate, a metal base circuit board, an inverter device, and a power semiconductor device.

2. Description of the Related Art Conventionally, an inverter device or a power semiconductor device in which an insulated gate bipolar transistor (IGBT) and a semiconductor element such as a diode, a resistor, and an electronic component such as a capacitor are mounted on a metal base circuit board is known. ing.
These power control devices are applied to various devices according to their withstand voltage and current capacity. In particular, from the viewpoint of environmental problems in recent years and the promotion of energy saving, the use of these power control devices for various electric machines is increasing year by year.
In particular, regarding an in-vehicle power control device, it is desired to install the power control device in an engine room together with downsizing and space saving. The engine room has a severe environment such as a high temperature and a large temperature change, and a substrate having a large heat radiation area is required. For such applications, a metal base circuit board that is further excellent in heat dissipation has attracted attention.

  Conventional metal-based circuit boards often use aluminum plates for heat dissipation and economic reasons, but if heating / cooling is repeated under actual use, the heat generated between the aluminum plates and electronic components, particularly chip components, is often used. A large thermal stress is generated due to the difference in the expansion coefficient, and there is a problem that the electrical reliability is lowered, for example, a crack is generated at or near the solder portion fixing the component.

In order to improve such points, it is necessary to increase the thermal conductivity of the insulating layer and lower the elastic modulus of the insulating layer to achieve higher levels of heat resistance and moisture resistance.
Hitherto, it has been disclosed that a resin composition having a reduced elastic modulus is used for an insulating layer by using acrylic rubber (see, for example, Patent Documents 1 and 2). However, when acrylic rubber was used, there was a problem in that sufficient performance could not be obtained in the heat cycle test.

  In addition, as another means for reducing the elastic modulus, a technique using a silicone resin or the like has been studied (for example, see Patent Document 3). However, when silicone resin is used, the adhesion to the metal plate is inferior, so the adhesion with the metal base plate is reduced, and the dielectric breakdown voltage value is reduced due to moisture absorption between the metal plate and the insulating layer. In terms, it left a challenge.

Japanese Patent Laid-Open No. 9-8426 JP-A-10-242606 JP 2005-281509 A

  An object of the present invention is to provide a resin composition, a resin sheet, a laminate, a metal base circuit board, an inverter device, and a power semiconductor that have excellent adhesion and heat cycle properties between a metal plate and an insulating layer and have a sufficient dielectric breakdown voltage value. To provide an apparatus.

The object of the present invention is achieved by the present invention described in the following items [1] to [7].
[1] A phenoxy resin having a structure represented by the following general formula (1), (B) an inorganic filler, and (C) a silane coupling agent, wherein the content of the (C) silane coupling agent is a resin composition The resin composition characterized by being 1 mass% or more and 10 mass% or less of the whole.

(However, in the said General formula (1), n and m are 1 or more and an integer of 20 or less mutually independent. R1-19 is a hydrogen atom, a C1-C10 hydrocarbon group, or a halogen atom. X may be a single bond or a hydrocarbon group having 1 to 20 carbon atoms, —O—, —S—, —SO ₂ — or —CO—. is there.)
[2] The resin composition according to item [1], wherein the content of the (A) phenoxy resin is 10% by mass or more and 40% by mass or less of the entire resin composition.
[3] A resin sheet obtained by laminating an insulating layer made of the resin composition according to the item [1] or [2] on a metal foil.
[4] A laminate comprising the resin sheet according to item [3] laminated on at least one surface of a metal plate so that the surface on the insulating layer side is in contact therewith.
[5] A conductor circuit is formed on at least one surface of the metal plate through an insulating layer made of the resin composition according to the item [1] or [2]. Metal base circuit board.
[6] An inverter device comprising an electronic component mounted on the metal base circuit board according to the item [5].
[7] A power semiconductor device, wherein an electronic component is mounted on the metal base circuit board according to the item [5].

  According to the present invention, a resin composition, a resin sheet, a laminate, a metal base circuit board, an inverter device, and a power that have excellent adhesion and heat cycle properties between a metal plate and an insulating layer and have a sufficient dielectric breakdown voltage value. A semiconductor device can be obtained.

First, the resin composition of the present invention will be described. The resin composition of the present invention includes (A) a phenoxy resin having a structure represented by the following general formula (1), (B) an inorganic filler, and (C) a silane coupling agent, and (C) a silane coupling agent. Is 1 mass% or more and 10 mass% or less of the whole resin composition. Thereby, the resin composition of this invention is excellent in the adhesiveness of a metal plate and an insulating layer, and heat cycle property, and can have sufficient dielectric breakdown voltage value. Moreover, the resin composition of this invention can show a favorable dielectric breakdown voltage value.

(However, in the said General formula (1), n and m are 1 or more and an integer of 20 or less mutually independent. R1-19 is a hydrogen atom, a C1-C10 hydrocarbon group, or a halogen atom. X may be a single bond or a hydrocarbon group having 1 to 20 carbon atoms, —O—, —S—, —SO ₂ — or —CO—. is there.)

  In addition, the resin composition of the present invention contains an inorganic filler, so that conventional heat dissipating properties, excellent electrical insulation properties such as withstand voltage, etc. are maintained, and the present invention. The elastic modulus of the cured product of the resin composition can be lowered.

Examples of the phenoxy resin having a structure represented by the general formula (1) (A) used in the resin composition of the present invention include phenoxy resins having a structure represented by the following general formulas (2) and (3).

(However, in the general formula (2), n and m are integers of 1 or more and 20 or less independent of each other.)

(However, in the general formula (3), n and m are integers of 1 or more and 20 or less independent of each other.)

(A) By including a phenoxy resin in an insulating layer, the adhesiveness of an insulating layer and a metal plate improves. In addition, the connection reliability is improved. For example, an inverter device and a power semiconductor device in which an electronic component is mounted on the metal base circuit board of the present invention, the electronic component and the metal base even in a rapid heating / cooling environment. No defects such as cracks occur at or near the solder joint where the circuit boards are joined.

  Since the (A) phenoxy resin used in the resin composition of the present invention has an imide bond in the skeleton, it has high heat resistance, and particularly excellent solder heat resistance. Moreover, since it has a nitrogen atom in the molecule, the adhesion between the metal plate and the insulating layer is particularly excellent, moisture absorption between the metal plate and the insulating layer does not occur, and the dielectric breakdown voltage value does not decrease.

(A) Although content of phenoxy resin is not specifically limited, It is preferable that it is 10 to 40 mass% of the whole resin composition. If it is less than the above lower limit value, the elastic modulus may not be sufficiently lowered, and if used for a metal base circuit board, the elastic modulus is not sufficiently lowered, and even when subjected to rapid heating / cooling, There is a risk of cracks in the vicinity. If it exceeds the above upper limit value, fluidity during pressing deteriorates and voids or the like are generated, so that the dielectric breakdown voltage value of the metal base circuit board may be lowered.
In addition, in the case of the varnish using a solvent etc., the whole resin composition means solid content except a solvent, and liquid components, such as a liquid epoxy and a coupling agent, are contained in a resin composition.

The inorganic filler (B) used in the resin composition of the present invention is not particularly limited. For example, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, calcium silicate, calcium oxide, magnesium oxide, alumina, nitriding Examples thereof include aluminum, aluminum borate whisker, boron nitride, crystalline silica, amorphous silica, silicon carbide and the like.

Among these, alumina, aluminum nitride, boron nitride, crystalline silica, and amorphous silica are preferable from the viewpoint of high thermal conductivity. More preferred is alumina. When alumina is used, it is preferable in terms of heat resistance and insulation in addition to high thermal conductivity.

  From the viewpoint of reliability, crystalline silica or amorphous silica is preferable. Further, crystalline silica or amorphous silica is preferable in that it has few ionic impurities. When crystalline silica or amorphous silica is contained in the insulating layer formed from the resin composition, a metal base circuit board having excellent insulation reliability can be obtained. In particular, a metal base circuit board using crystalline silica or amorphous silica is suitable in that it has high insulation under a water vapor atmosphere such as a pressure cooker test, and has little corrosion on metals, aluminum wires, aluminum plates, etc. .

On the other hand, from the viewpoint of flame retardancy, aluminum hydroxide and magnesium hydroxide are preferred. Furthermore, for the purpose of adjusting melt viscosity and imparting cyclotropic properties, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, calcium silicate, magnesium silicate, calcium oxide, magnesium oxide, alumina, crystalline silica, Amorphous silica is preferred.

  (B) Although content of an inorganic filler is not specifically limited, It is preferable that they are 40 mass% or more and 70 mass% or less of the whole resin composition. If it is less than the above lower limit value, the thermal resistance may increase and sufficient heat dissipation may not be obtained, and if it exceeds the above upper limit value, fluidity during pressing may be deteriorated and voids may be generated. .

  By including the (C) silane coupling agent in the resin composition of the present invention, the adhesion between the metal plate and the insulating layer is improved, and the dielectric breakdown voltage value of the metal base circuit board is improved as compared with the conventional case. This is presumably due to a synergistic effect of the combination of (A) a phenoxy resin and (B) an inorganic filler.

  (C) It is preferable that content of a silane coupling agent is 1 to 10 mass% of the whole resin composition. More preferably, they are 3 mass% or more and 7 mass% or less. If the content is less than the above lower limit, the adhesion between the metal plate and the insulating layer may be reduced, and the solder heat resistance of the metal base circuit board may be reduced. On the other hand, when the above upper limit is exceeded, a large amount of the silane coupling agent is present, so that the crosslink density is lowered and the solder heat resistance may be lowered.

  An epoxy resin can be used as a modifier in the resin composition of the present invention. By adding an epoxy resin, the moisture resistance and heat resistance of the resin composition, particularly the heat resistance after moisture absorption is improved. The epoxy resin is not particularly limited as long as it is an epoxy resin having two or more epoxy groups in one molecule. For example, bisphenol A, bisphenol F, biphenyl, novolac, polyfunctional phenol, naphthalene And glycidyl ethers such as alicyclic and alcohols, glycidyl amines and glycidyl esters. These epoxy resins may be used alone or in combination of two or more.

  Among these, from the viewpoint of heat resistance, moisture resistance, metal adhesion, and fluidity during press molding, bisphenol A epoxy resin is preferable, and bisphenol A epoxy resin that is liquid at room temperature is particularly preferable. The bisphenol A epoxy resin that is liquid at room temperature is particularly excellent in fluidity at the time of press molding, has excellent compatibility with the phenoxy resin, and does not cause phase separation or the like, and thus has excellent heat resistance.

  The resin composition of the present invention may contain an epoxy resin curing agent and / or a curing catalyst. Although it does not specifically limit as a hardening | curing agent, For example, an acid anhydride, an amine compound, a phenol compound, etc. are mentioned. Moreover, it does not specifically limit as a hardening | curing agent or a curing catalyst, For example, imidazoles and its derivative (s), tertiary amines, a quaternary ammonium salt etc. are mentioned.

  Other known thermoplastic resins, elastomers, flame retardants and fillers, dyes, ultraviolet absorbers and the like can be appropriately added to the resin composition of the present invention as necessary.

  Next, the resin sheet of the present invention will be described. The resin sheet of this invention is obtained by laminating | stacking the insulating layer which consists of a resin composition of this invention mentioned above on metal foil.

  More specifically, first, in order to form an insulating layer, the resin composition of the present invention is mixed with acetone, methyl ethyl ketone, methyl isobutyl ketone, toluene, ethyl acetate, cyclohexane, heptane, cyclohexane cyclohexanone, tetrahydrofuran, dimethylformamide, dimethylacetamide, In organic solvents such as dimethyl sulfoxide, ethylene glycol, cellosolve, carbitol, anisole, etc., ultrasonic dispersion method, high-pressure collision dispersion method, high-speed rotation dispersion method, bead mill method, high-speed shear dispersion method, and rotation and revolution dispersion method A resin varnish is prepared by dissolving, mixing, and stirring using various mixers. Here, although content of the resin composition in a resin varnish is not specifically limited, 45 mass% or more and 85 mass% or less are preferable, and 55 mass% or more and 75 mass% or less are especially preferable.

  Next, the resin varnish is coated on the metal foil using various coating apparatuses, and then dried. Or after spray-coating a resin varnish on metal foil with a spray apparatus, this is dried. A resin sheet can be produced by these methods. Although it does not specifically limit as a coating apparatus, For example, a roll coater, a bar coater, a knife coater, a gravure coater, a die coater, a comma coater, a curtain coater, etc. can be used. Among these, a method using a die coater, a knife coater and a comma coater is preferable. Thereby, the resin sheet which does not have a void and has the thickness of a uniform insulating layer can be manufactured efficiently.

  The thickness of the insulating layer in the resin sheet of the present invention is preferably in the range of 50 μm or more and 250 μm. When the value is less than the lower limit, when used for the metal base circuit board of the present invention described later, for example, the generation of thermal stress due to the difference in thermal expansion coefficient from a metal plate such as an aluminum plate cannot be sufficiently mitigated by the insulating layer. . As a result, when a semiconductor element, a resistor component, or the like is surface-mounted on a metal base circuit board, distortion may increase and sufficient thermal shock reliability may not be obtained. When the above upper limit is exceeded, the amount of distortion of the surface-mounted portion is small and good thermal shock reliability can be obtained, but since the thermal resistance increases, sufficient heat dissipation cannot be obtained.

  Although the metal foil in the resin sheet of the present invention is not particularly limited, for example, copper and copper alloys, aluminum and aluminum alloys, silver and silver alloys, gold and gold alloys, zinc and zinc alloys, nickel and nickel alloys Metal foils, such as an alloy, tin, a tin-type alloy, iron, and an iron-type alloy, are mentioned. Among these, copper is preferable because the metal foil can be used as a conductor circuit by etching. From the viewpoint of low thermal expansion, an iron-nickel alloy is preferable.

  The method for producing the metal foil may be an electrolytic method or a rolling method, and metal plating such as Ni plating, Ni-Au plating, or solder plating may be applied on the metal foil. From the viewpoint of adhesion, it is more preferable that the surface of the conductor circuit on the side in contact with the insulating layer is roughened in advance by etching, plating, or the like.

  The thickness of the metal foil is not particularly limited, but is preferably 0.5 μm or more and 105 μm or less, more preferably 1 μm or more and 70 μm or less, and further preferably 9 μm or more and 35 μm or less. If the thickness of the metal foil is less than the above lower limit, pinholes are likely to occur, and when the metal foil is etched and used as a conductor circuit, plating variations during circuit pattern formation, circuit disconnection, etching solution, desmear solution, etc. There is a fear of infiltration of chemicals. Moreover, when the said upper limit is exceeded, the thickness variation of metal foil may become large, or the surface roughness variation of a metal foil roughening surface may become large.

  The metal foil can also be an ultrathin metal foil with a carrier foil. The ultrathin metal foil with a carrier foil is a metal foil obtained by laminating a peelable carrier foil and an ultrathin metal foil. Since an ultrathin metal foil layer can be formed on both sides of an insulating layer by using an ultrathin metal foil with a carrier foil, for example, when forming a circuit by a semi-additive method, an ultrathin metal without performing electroless plating By electroplating the foil as a direct power supply layer, the ultrathin copper foil can be flash etched after the circuit is formed. By using an ultra-thin metal foil with a carrier foil, even with an ultra-thin metal foil having a thickness of 10 μm or less, for example, a reduction in handling properties of the ultra-thin metal foil in a pressing process, and cracking or cutting of the ultra-thin copper foil are prevented. Can do.

  Next, the laminated board and metal base circuit board of this invention are demonstrated. The laminated plate of the present invention is not particularly limited. For example, the laminated plate is laminated so that the surface on the insulating layer side of the resin sheet of the present invention described above is in contact with one side or both sides of the metal plate, and is pressed and heated using a press or the like. It can be obtained by curing to form an insulating resin cured layer. The metal base circuit board of the present invention can be obtained by forming a circuit by etching the metal foil of the obtained laminate. In addition, when making a metal base circuit board into a multilayer, the resin sheet was further laminated | stacked so that the surface by the side of the insulating layer of a resin sheet might contact | connect on the metal base circuit board after circuit formation, and it was made to pressurize and heat-cure. Thereafter, a multilayer metal base circuit board can be obtained by forming a circuit by etching the outermost metal foil. Note that a solder resist may be formed on the outermost layer, and the connection electrode portion may be exposed so that a semiconductor element or an electronic component can be mounted by exposure and development.

  The thickness of the metal plate is not particularly limited, but is preferably 0.5 mm or more and 5.0 mm. This is because it is excellent in heat dissipation and economical.

  As another method for producing the laminate of the present invention, there is a method in which a resin varnish is applied to a metal plate, and then a metal foil is laminated and heated and pressurized. Also in this case, a metal base circuit board can be obtained by etching the metal foil of the obtained laminate and forming a circuit. In addition, after applying a resin varnish to a metal plate and curing the resin, circuit formation may be performed by electroless plating and electrolytic plating.

  The metal base circuit board of the present invention is applied to power control devices such as inverter devices and power semiconductor devices in which electronic components are mounted on conductor circuits. Here, the inverter device is an apparatus that electrically generates AC power from DC power (has a function of reverse conversion). In addition, the power semiconductor device is characterized by higher withstand voltage, higher current, higher speed and higher frequency than ordinary semiconductor elements, generally called power devices, rectifier diodes, power transistors, Examples include a power MOSFET, an insulated gate bipolar transistor (IGBT), a thyristor, a gate turn-off thyristor (GTO), and a triac.

  EXAMPLES Hereinafter, although this invention is demonstrated in detail based on an Example and a comparative example, this invention is not limited to this.

Synthesis example (1)
Synthesis of phenoxy resin 1 having a structure represented by the following general formula (2) 190 parts by mass of DIC 850S as a bifunctional epoxy resin and imide-modified phenol represented by JP-A-2006-83128 (formula 1-2) as a phenol compound 220 parts by mass, 0.5 part by mass of tetramethylammonium chloride as a catalyst and 100 parts of cyclohexanone were put in a pressure-resistant reaction vessel, and a polymerization reaction was carried out at 150 ° C. for 5 hours in a nitrogen gas atmosphere. The solvent was removed from the reaction product to obtain phenoxy resin 1. The weight average molecular weight of the phenoxy resin 1 was 37000.

(However, in the general formula (2), n and m are integers of 1 or more and 20 or less independent of each other.)

Synthesis example (2)
Synthesis of phenoxy resin 2 having a structure represented by the following general formula (3) 190 parts by mass of Mitsubishi Chemical YX-4000 as a bifunctional epoxy resin, and JP-A-2006-83128 (formula 1-2) as a phenol compound 220 parts by mass of imide-modified phenol, 0.5 part by mass of tetramethylammonium chloride and 100 parts of cyclohexanone as a catalyst were put in a pressure-resistant reaction vessel, and a polymerization reaction was performed at 150 ° C. for 5 hours in a nitrogen gas atmosphere. The solvent was removed from the reaction product to obtain phenoxy resin 2. The weight average molecular weight of the phenoxy resin 2 was 23000.

(However, in the general formula (3), n and m are integers of 1 or more and 20 or less independent of each other.)

The raw materials used in Examples and Comparative Examples are as follows.
(1) Phenoxy resin 1 synthesized in Synthesis Example 1
(2) Phenoxy resin 2 synthesized in Synthesis Example 2
(3) Bisphenol A type epoxy resin (made by DIC, 850S, epoxy equivalent 190)
(4) Dicyandiamide (Degussa)
(5) Phenol novolac resin (DIC, TD-2010, hydroxyl equivalent 105)
(6) 2-phenylimidazole (manufactured by Shikoku Chemicals, 2PZ)
(7) γ-Glycidoxypropyltritomexisilane (manufactured by Shin-Etsu Silicone, KBM-403)
(8) Alumina (manufactured by Denki Kagaku Kogyo, AS-50)
(9) Boron nitride (manufactured by Denki Kagaku Kogyo, SPG-3)
(10) Bisphenol A type phenoxy resin 3 (Mitsubishi Chemical, 1256, weight average molecular weight 5.1 × 10 ⁴ )
(11) Silicone resin 1 (Momentive Performers XE14-A0425 (A
), Polyalkenylsiloxane)
(12) Silicone resin 2 (XE14-A0425 (B) manufactured by Momentive Performers, polyalkyl hydrogen siloxane)

Example 1
(1) Preparation of resin varnish Phenoxy resin 1 (synthesized in Synthesis Example 1) 16.8 parts by mass Bisphenol A type epoxy resin (DIC, 850S, epoxy equivalent 190)
19.7 parts by mass 2-phenylimidazole (2PZ manufactured by Shikoku Kasei) 0.5 parts by mass γ-glycidoxypropyltrimethoxysilane (KBM-403 manufactured by Shin-Etsu Silicone)
3.0 parts by mass Alumina (manufactured by Denki Kagaku Kogyo Co., Ltd., AS-50) 60.0 parts by mass was dissolved and mixed in cyclohexanone and stirred using a high-speed agitator, so that the resin composition was 70% by mass based on the solid content. A resin varnish was obtained.

(2) Production of Resin Sheet Using a 70 μm thick copper foil (manufactured by Furukawa Circuit Foil, GTSMP) as a metal foil, a resin varnish was applied to the roughened surface of the copper foil with a comma coater, and 3 minutes at 100 ° C. The resin-coated copper foil (resin sheet) having a resin thickness of 100 μm was obtained by heating and drying at 150 ° C. for 3 minutes.

(3) Production of laminated plate The resin sheet and the 2 mm-thick aluminum plate were laminated so that the surface on the insulating layer side of the resin sheet obtained in the above was in contact, and was vacuum-pressed at 80 ° C for 30 minutes at a press pressure of 2.9 MPa. The laminate was obtained by pressing at 200 ° C. for 90 minutes.
(4) Production of inverter device In order to form a circuit on the obtained laminate, unnecessary parts other than the circuit are removed by etching. After the circuit is formed, a test electronic component is mounted on the predetermined part and soldered. By doing, the inverter device was obtained.

(Examples 2-6 and Comparative Examples 1-5)
A resin varnish was prepared in the same manner as in Example 1 except that a resin varnish was prepared according to the recipe shown in Tables 1 and 2, and a resin sheet, a laminate and an inverter device were produced.
Moreover, each evaluation of the following was performed about the metal base circuit board obtained by each Example and the comparative example. The evaluation results are shown in Tables 1 and 2.

(Evaluation method)
The evaluation method is shown below for each evaluation.

(1) Peel strength The laminates obtained in the examples and comparative examples were cut with a grinder saw to prepare 100 mm × 20 mm test pieces, and the peel strength between the aluminum plate and the cured resin layer at 23 ° C. was measured. The peel strength measurement was performed according to JIS C 6481.

(2) Solder heat resistance After the obtained laminated plate was cut into a 50 mm × 50 mm with a grinder saw, a sample in which only 1/4 of the copper foil was left by etching was prepared and evaluated in accordance with JIS C 6481. In the case of no pretreatment and after 121 ° C., 100%, (PCT treatment) for 4 hours, the presence or absence of abnormal appearance was examined after being immersed in a solder bath at 288 ° C. for 30 seconds. .
Evaluation criteria: No abnormality: Swelling (there is a swelling part as a whole)

(3) Dielectric breakdown voltage After the obtained laminated plate was cut into a size of 100 mm × 100 mm with a grinder saw, the copper foil in the outer portion was removed by etching from a position of about 30 mm from the edge portion to prepare a sample. Using a withstand voltage tester (MODEL7473, manufactured by EXTECH Electronics), an electrode was brought into contact with the copper foil and the aluminum plate, and an alternating voltage was applied to both electrodes so that the voltage increased at a rate of 1 kV / sec. The voltage at which the cured resin layer of the laminate was broken was defined as the dielectric breakdown voltage.

(4) Thermal conductivity The density of the obtained laminate was measured by an underwater substitution method, the specific heat was measured by DSC (differential scanning calorimetry), and the thermal diffusivity was further measured by a laser flash method. And thermal conductivity was computed from the following formula | equation.
Thermal conductivity (W / m · K) = density (kg / m ³ ) × specific heat (kJ / kg · K) × thermal diffusivity (m ² / S) × 1000

(5) Heat cycle test Using the inverter device obtained in the above, after performing a heat cycle test 10,000 times with -40 ° C 7 minutes and + 125 ° C 7 minutes as one cycle, the presence or absence of cracks in the solder portion with a microscope Was observed. Those having a crack occurrence of 10% or more in the solder portion were judged as defective, and those having a solder crack occurrence of less than 10% were judged good.
Evaluation criteria: Good: Poor (crack generation rate of 10% or more)

From the evaluation results described in Tables 1 and 2, the following was found.
In Comparative Example 1 using the phenoxy resin 3 having a structure different from the phenoxy resin having the structure represented by the general formula (1) of the present invention (A), the solder heat resistance after the PCT treatment in the laminate, and the inverter The result was inferior heat cycle performance in the apparatus. Moreover, in the comparative example 2 with little content of a silane coupling agent, the peel strength in a laminated board fell, and it resulted in the solder heat resistance after a PCT process being inferior. On the other hand, in Comparative Example 3 in which the content of the silane coupling agent was excessive, the peel strength itself in the laminate was not lowered, but the solder heat resistance after the PCT treatment was inferior. Moreover, in the comparative example 4 which did not use an inorganic filler, the heat conductivity in a laminated board became a low value. Furthermore, in Comparative Example 5 using a silicone resin instead of using the phenoxy resin and the epoxy resin having the structure represented by (A) general formula (1) of the present invention, the peel strength in the laminate is lowered, and the PCT treatment Later solder heat resistance was also inferior. Moreover, the dielectric breakdown voltage became a low value.
In contrast, Examples 1 to 6 include (A) a phenoxy resin having a structure represented by the general formula (1), (B) an inorganic filler, and (C) a silane coupling agent. A resin composition in which the content of the ring agent is 1% by mass or more and 10% by mass or less of the whole resin composition, (A) a modified type of phenoxy resin, (B) an inorganic filler Including the modified type of (C) the content of the silane coupling agent and the modified type of the curing agent / curing accelerator. The strength was high and the solder heat resistance was excellent. Moreover, it had sufficient dielectric breakdown voltage value and high thermal conductivity. Moreover, the favorable result was obtained also about the heat cycle property in an inverter apparatus.
Therefore, it was found that by using the resin composition according to the present invention, a metal base circuit board, an inverter device, and a power semiconductor device having excellent performance can be obtained.

According to the present invention, since the adhesion between the metal plate and the insulating layer and the heat cycle property are excellent, and a sufficient dielectric breakdown voltage value and high thermal conductivity can be obtained, the resin composition and resin sheet of the present invention can be obtained. The laminated board, the metal base circuit board, the inverter device, and the power semiconductor device can be suitably used as materials used in harsh environments such as automobile engine rooms.

Claims (7)

(A) a phenoxy resin having a structure represented by the following general formula (1), (B) an inorganic filler, and (C) a silane coupling agent, wherein the content of the (C) silane coupling agent is a resin composition The resin composition characterized by being 1 mass% or more and 10 mass% or less of the whole.

(However, in the said General formula (1), n and m are 1 or more and an integer of 20 or less mutually independent. R1-19 is a hydrogen atom, a C1-C10 hydrocarbon group, or a halogen atom. X may be a single bond or a hydrocarbon group having 1 to 20 carbon atoms, —O—, —S—, —SO ₂ — or —CO—. is there.)   2. The resin composition according to claim 1, wherein the content of the (A) phenoxy resin is 10% by mass or more and 40% by mass or less of the entire resin composition.   A resin sheet obtained by laminating an insulating layer made of the resin composition according to claim 1 or 2 on a metal foil.   A laminated sheet comprising the resin sheet according to claim 3 laminated on at least one surface of a metal plate so that the surface on the insulating layer side is in contact therewith.   A metal base circuit board, wherein a conductor circuit is formed on at least one surface of the metal plate via an insulating layer made of the resin composition according to claim 1 or 2.   An inverter device comprising an electronic component mounted on the metal base circuit board according to claim 5. An electronic component is mounted on the metal base circuit board according to claim 5.