JP2020066661A - Encapsulation resin composition and onboard electronic controller therewith - Google Patents

Abstract

To provide an encapsulation resin composition having excellent temperature cycle resistance and filling property.SOLUTION: An encapsulation resin composition of the present invention is an encapsulation resin composition used to form an encapsulation resin member in an on-board electronic controller including a wiring board, a plurality of electronic components mounted on at least one surface of the wiring board, and an encapsulation resin member for encapsulating the plurality of electronic components and includes a thermosetting resin and an inorganic filler. A difference(α-α) of an average coefficient of linear expansion from 40°C to 150°C represented by α,αmeasured according to a predetermined procedure is 0 or larger and 6.0 or smaller, a time Tduring which a torque value of the encapsulation resin composition is two times or smaller of a lowest torque value, measured according to a predetermined procedure, is 5 seconds or larger and 50 seconds or smaller, and the lowest torque value of the encapsulation resin composition is 0.5 Nm or larger and 4.5 Nm or smaller.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a sealing resin composition and a vehicle-mounted electronic control device using the same.

  Until now, various developments have been made in the encapsulating resin composition used in the on-vehicle electronic control device. As this type of technology, for example, the technology described in Patent Document 1 is known. Patent Document 1 describes that an epoxy resin is mainly used as a sealing resin for sealing a circuit board in an in-vehicle electronic control device (paragraphs 0012 and 0022 of Patent Document 1).

JP, 2013-258184, A

  However, as a result of the study by the present inventor, it was found that the encapsulating resin composition described in Patent Document 1 has room for improvement in terms of temperature cycle resistance and filling property.

In recent years, in the technical field of in-vehicle electronic control devices, it has been required to mold a sealing resin composition for forming a sealing resin member for sealing an electronic component in a shorter time.
Generally, a molded body (hereinafter, "E molded body") after post-curing (post-curing) the sealing resin composition is used as a sealing resin member.
On the other hand, by using a molded body before post-cure (hereinafter referred to as "As molded body"), which is obtained by as-molding the encapsulating resin composition, a shorter time is required as compared with the case of the E molded body. A sealed body can be obtained with.

However, as a result of the study by the present inventor, since the ordinary As molded body is in a state where it is not sufficiently cured, the difference in thermal expansion between the substrate and the solder is large, and as a result, solder cracks are generated in the initial stage of the temperature cycle test. It has become clear that there is a risk that
As a result of further studies based on such knowledge, as molding using an encapsulating resin composition by using an encapsulating resin composition having a small difference in linear expansion coefficient between the As molded article and the E molded article. The inventors have found that even if the body is used as a sealing resin member, solder cracks can be suppressed and temperature cycle resistance can be improved, and the present invention has been completed.

  Further, as a result of the study by the present inventors, it was found that by appropriately adjusting the melting characteristics of the encapsulating resin composition, it is possible to suppress the occurrence of unfilled portions such as weld voids when encapsulating an electronic component. .

According to the invention,
A wiring board, a plurality of electronic components mounted on at least one surface of the wiring board, and a sealing resin member for sealing the plurality of electronic components, the sealing resin member in an in-vehicle electronic control device A sealing resin composition used for forming,
A thermosetting resin,
Including an inorganic filler,
The difference (α _As −α _E ) between the average linear expansion coefficients of 40 ° C. to 150 ° C., which is represented by α _E and α _As measured in the following procedure A, is 0 or more and 6.0 or less,
The time T ₁ when the torque value of the encapsulating resin composition is twice the minimum torque value or less, which is measured in the following procedure B, is 5 seconds or more and 50 seconds or less, and the encapsulating resin composition There is provided a sealing resin composition having a minimum torque value of 0.5 N · m or more and 4.5 N · m or less.
(Procedure A)
Using the encapsulating resin composition, a die molding is performed under molding conditions of 175 ° C. for 3 minutes to prepare an as-molded test piece of length × width × thickness: 10 mm × 80 mm × 4 mmt. The average line when measured in a flow direction from the center of the surface of the obtained as-molded test piece using a thermomechanical analyzer under conditions of a temperature increase of 5 ° C./min and a temperature range of 40 ° C. to 150 ° C. Let the expansion coefficient be α _As (ppm / ° C.).
The obtained as-molded test piece is subjected to a post-curing treatment under a curing condition of 180 ° C. for 8 hours to prepare a post-curing test piece. Average line when measured in the flow direction from the center of the surface of the obtained post-curing test piece using a thermomechanical analyzer under conditions of a temperature increase of 5 ° C./min and a temperature range of 40 ° C. to 150 ° C. Let the expansion coefficient be α _E (ppm / ° C.).
(Procedure B)
Using a Labo Plastomill, the torque value of the encapsulating resin composition is measured over time under the conditions of a rotation speed of 30 rpm and a measurement temperature of 150 ° C.
The measurement start point of the Labo Plastomill measurement is P ₁ , the point where the torque value is the minimum torque value is P _3, and the point where the torque value is twice the minimum torque value between P ₁ and P ₃ is P. _2, and the point where the torque value becomes twice the minimum torque value after passing P ₃ is P ₄ .
The measurement start point P ₁ of the Laboplast mill measurement is a point at which the material is put into the Laboplast mill and the torque rises sharply and then the torque starts to fall.
The time from P ₃ to P ₄ is defined as time T ₁ when the torque value is twice the minimum torque value or less.

According to the invention,
Wiring board,
A plurality of electronic components mounted on at least one surface of the wiring board,
An in-vehicle electronic control device comprising: a sealing resin member that seals the plurality of electronic components,
There is provided an in-vehicle electronic control device, wherein the encapsulating resin member is composed of a molded product of the encapsulating resin composition.

  ADVANTAGE OF THE INVENTION According to this invention, the resin composition for sealing excellent in temperature cycling resistance and filling nature, and the vehicle-mounted electronic control apparatus using the same are provided.

It is a cross-sectional schematic diagram which shows an example of the vehicle-mounted electronic control device which concerns on embodiment. It is a graph which shows typically the relationship between the torque value and measurement time obtained by measurement using a Labo Plastomill.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all the drawings, the same constituents will be referred to with the same numerals, and the description thereof will not be repeated. Moreover, the figure is a schematic view and does not match the actual dimensional ratio.

FIG. 1 is a schematic sectional view showing an example of an in-vehicle electronic control device 10 according to the present embodiment.
The in-vehicle electronic control device 10 shown in FIG. 1 includes, for example, a wiring board 12, a plurality of electronic components 16 mounted on at least one surface of the wiring board 12, and a sealing resin member 14 that seals the electronic components 16. It is equipped with.

  The in-vehicle electronic control device 10 is used to control an engine, various in-vehicle devices, and the like. Specific examples of the in-vehicle electronic control device 10 are, for example, an ECU (engine control unit) and an ATCU (automatic transmission control unit) mounted in an engine room.

  The encapsulating resin composition of the present embodiment includes a wiring board 12, a plurality of electronic components 16 mounted on the wiring board 12, and an encapsulating resin member 14 that seals the electronic components 16. It is used for forming the sealing resin member 14 of the electronic control unit 10.

The encapsulating resin composition of the present embodiment contains a thermosetting resin and an inorganic filler, and is represented by α _E and α _As measured in the following procedure A, and is at 40 ° C. to 150 ° C. The difference in average linear expansion coefficient (α _As −α _E ) is 0 or more and 6.0 or less, and the torque value of the resin composition for sealing, which is measured in the following procedure B, is twice the minimum torque value. The following time T ₁ is 5 seconds or more and 50 seconds or less, and the minimum torque value of the sealing resin composition is 0.5 N · m or more and 4.5 N · m or less.

(Procedure A)
Using the encapsulating resin composition, a die molding is performed under molding conditions of 175 ° C. for 3 minutes to prepare an as-molded test piece of length × width × thickness: 10 mm × 80 mm × 4 mmt. The average linear expansion when measured in the flow direction from the center of the surface of the obtained as-molded test piece using a thermomechanical analyzer under conditions of a temperature increase of 5 ° C / min and a temperature range of 40 ° C to 150 ° C. The coefficient is α _As (ppm / ° C.).
Using the obtained as-molded test piece, a post-curing treatment is performed under a curing condition of 180 ° C. for 8 hours to prepare a post-curing test piece. Average linear expansion when measured in a flow direction from the center of the surface of the obtained post-cured test piece using a thermomechanical analyzer under conditions of a temperature increase of 5 ° C / min and a temperature range of 40 ° C to 150 ° C. The coefficient is α _E (ppm / ° C.).

  In the present embodiment, a molded product obtained by molding the encapsulating resin composition under molding conditions of 175 ° C. for 3 minutes is referred to as “As molded body”. Further, a product obtained by subjecting the as-molded product () to a post-curing treatment (post-cure) under curing conditions of 180 ° C. and 8 hours is referred to as an “E-molded product”.

(Procedure B)
Using a Labo Plastomill, the torque value of the encapsulating resin composition is measured over time under the conditions of a rotation speed of 30 rpm and a measurement temperature of 150 ° C.
The measurement start point of the Labo Plastomill measurement is P ₁ , the point where the torque value is the minimum torque value is P _3, and the point where the torque value is twice the minimum torque value between P ₁ and P ₃ is P. _2, and the point where the torque value becomes twice the minimum torque value after passing P ₃ is P ₄ .
The measurement start point P ₁ of the Laboplast mill measurement is a point at which the material is put into the Laboplast mill and the torque rises sharply and then the torque starts to fall.
The time from P ₃ to P ₄ is defined as time T ₁ when the torque value is twice the minimum torque value or less.

As a result of a study by the present inventors, since a normal As molded body is in a state where it is not sufficiently cured, the difference in thermal expansion between the substrate and solder is large, and as a result, solder cracks occur in the initial stage of the temperature cycle test. It turned out to be easier.
As a result of further studies based on such knowledge, as molding using an encapsulating resin composition by using an encapsulating resin composition having a small difference in linear expansion coefficient between the As molded article and the E molded article. It has been found that even if the body is used as a sealing resin member, solder cracks can be suppressed and temperature cycle resistance can be improved.

  Further, as a result of the study by the present inventors, it was found that by appropriately adjusting the melting characteristics of the encapsulating resin composition, it is possible to suppress the occurrence of unfilled portions such as weld voids when encapsulating an electronic component. .

  Therefore, according to the encapsulating resin composition of the present embodiment, since the substrate has a suitable melting property, it is possible to encapsulate the substrates all at once, and to shorten the encapsulating step by using the As molded body as the encapsulating member. By suppressing the variation of the linear expansion coefficient between the As molded body and the E molded body, it is possible to reduce the difference in the thermal expansion difference between the As molded body and the solder or the substrate, so that repeated thermal history is added. It becomes possible to suppress the generation of solder cracks under the use environment.

In the present embodiment, for example, by appropriately selecting the type and amount of each component contained in the encapsulating resin composition, the method for preparing the encapsulating resin composition, etc., the above (α _As −α _E ) , Α _E , α _As , time T ₁ , and the minimum torque value can be controlled. Among these, for example, using a phenolic resin as the thermosetting resin, adjusting the compounding ratio of the resol type phenolic resin and the novolak type phenolic resin appropriately, accelerating the curing, reducing the amount of filler to reduce the amount of resin. Increasing, etc. are mentioned as the factors for setting the above (α _As −α _E ), α _E , α _As , time T ₁ , and the minimum torque value within a desired numerical range.

<Sealing resin composition>
The encapsulating resin composition of the present embodiment is a thermosetting resin composition containing a thermosetting resin.

  Examples of the thermosetting resin include phenol resin, epoxy resin, unsaturated polyester resin, diallyl phthalate resin, melamine resin, oxetane resin, maleimide resin, urea (urea) resin, polyurethane resin, silicone resin, and resin having a benzoxazine ring. , Cyanate ester resin and the like are used. These may be used alone or in combination of two or more. Among these, it is preferable to use the phenol resin from the viewpoint that the linear expansion coefficient at the time of as-molding can be made relatively small.

  The lower limit of the content of the phenolic resin is, for example, 20% by mass or more, preferably 30% by mass or more, and more preferably 50% by mass or more based on the whole thermosetting resin (100% by mass). By increasing the content ratio of the phenol resin in the thermosetting resin, it is possible to suppress an increase in the fluctuation of the linear expansion coefficient of the As molded body. On the other hand, the lower limit of the content of the phenol resin may be, for example, 100% by mass or less with respect to the entire thermosetting resin (100% by mass).

  Examples of the phenolic resin include novolak type phenolic resins such as phenol novolac resin, cresol novolac resin, bisphenol A type novolac resin; methylol type resole resin, dimethylene ether type resole resin, tung oil, linseed oil, walnut oil, etc. Resol type phenolic resins such as oil-melted resol type phenolic resins; arylalkylene type phenolic resins and the like. These may be used alone or in combination of two or more. Among these, it is preferable to use a resol-type phenol resin from the viewpoint of rapid curing property.

  As the resol-type phenol resin, for example, those obtained by reacting phenols and aldehydes under alkaline conditions or under weak acidity are used.

As the above-mentioned phenols, for example, the number of phenol rings may be mononuclear, dinuclear or trinuclear, and the number of phenolic hydroxyl groups may be 1 or 2 or more.
Examples of the above-mentioned phenols are not particularly limited, but include, for example, phenol; cresols such as orthocresol, metacresol, and paracresol; 2,3-xylenol, 2,4-xylenol, 2,5-xylenol, 2,6. -Xylenol, xylenol such as 3,5-xylenol; 2,3,5-trimethylphenol, 2-ethylphenol, 4-ethylphenol, 2-isopropylphenol, 4-isopropylphenol, n-butylphenol, isobutylphenol, tert- Alkylphenols such as butylphenol, hexylphenol, octylphenol, nonylphenol, phenylphenol, benzylphenol, cumylphenol, allylphenol, cardanol, urushiol, lacole; 1 Naphthol such as naphthol and 2-naphthol; halogenated phenol such as fluorophenol, chlorophenol, bromophenol and iodophenol, monovalent phenol substitution product such as p-phenylphenol, aminophenol, nitrophenol, dinitrophenol and trinitrophenol Bisphenols such as bisphenol S, bisphenol F, bisphenol A, bisphenol C, bisphenol Z, bisphenol E; resorcin, alkylresorcin, pyrogallol, catechol, alkylcatechol, hydroquinone, alkylhydroquinone, phloroglucin, dihydroxynaphthalene, naphthalene and other polyhydric phenols ; And the like. These may be used alone or in combination of two or more. Among these, the phenols can contain one or more selected from the group consisting of phenol, cresol, xylenol, alkylphenol and bisphenol, and from the viewpoint of cost, phenol, cresol, butylphenol, bisphenol A can be used. .

  The aldehydes are not particularly limited, for example, formaldehyde such as formalin and paraformaldehyde; trioxane, acetaldehyde, paraaldehyde, propionaldehyde, polyoxymethylene, chloral, hexamethylenetetramine, furfural, glyoxal, n-butyraldehyde, Examples thereof include isobutyraldehyde, tert-butyraldehyde, caproaldehyde, allylaldehyde, benzaldehyde, crotonaldehyde, acrolein, tetraoxymethylene, phenylacetaldehyde, o-tolualdehyde, salicylaldehyde and the like. You may use these aldehydes individually or in combination of 2 or more types. Among these, the aldehydes can include formaldehyde or acetaldehyde, and formalin or paraformaldehyde can be used from the viewpoint of productivity and low cost.

Under alkaline conditions, alkaline catalysts can be used.
The alkaline catalyst is not particularly limited, for example, sodium hydroxide, lithium hydroxide, potassium hydroxide, aqueous ammonia, amines such as monomethylamine, dimethylamine, trimethylamine, monoethylamine, diethylamine, methylethylamine, triethylamine, Alkaline earth metal oxides and hydroxides such as calcium, magnesium and barium, and alkaline substances such as sodium carbonate and hexamethylenetetramine can be used. These may be used alone or in combination of two or more. For example, sodium hydroxide may be used.

Further, in the case of weak acidity, a zinc-based catalyst can be used.
The zinc-based catalyst is not particularly limited, and any divalent metal salt catalyst can be used. For example, zinc acetate or zinc formate can be used. These may be used alone or in combination of two or more. For example, a hydrate of zinc acetate may be used.

  The addition amount of the alkaline catalyst or the zinc-based catalyst may be, for example, 0.01% by mass to 20% by mass, preferably 0.1% by mass to 10% by mass, relative to 100% by mass of phenols. You can

  The molar ratio of phenols to aldehydes (F / P molar ratio) may be, for example, 0.7 mol to 4.0 mol of aldehydes, preferably 1.0 mol, relative to 1 mol of phenols. Can be up to 3.0 mol. By setting the aldehydes in the above range, the conversion rate of the aldehydes is increased with respect to 1 mol of the phenols as described above, and the residual unreacted aldehydes can be reduced.

  The lower limit of the content of the resol-type phenol resin is, for example, 60% by mass or more, preferably 70% by mass or more, and more preferably 80% by mass or more with respect to the entire phenol resin (100% by mass). This can enhance the rapid curing property of the encapsulating resin composition. Thereby, temperature cycle resistance can be improved. The upper limit of the content of the resol-type phenol resin may be, for example, 100% by mass or less and 95% by mass or less with respect to the entire phenol resin (100% by mass). This makes it possible to balance the physical properties of the molded product of the encapsulating resin composition.

  Such a sealing resin composition includes a wiring board, a plurality of electronic components mounted on at least one surface of the wiring board, and a sealing resin member for sealing the plurality of electronic components. A sealing resin composition used for forming a sealing resin member in a control device, comprising a phenol resin and an inorganic filler, and a resol type phenol resin and a novolac type phenol resin in the phenol resin. The content ratio of (resol: novolac content ratio) can be 60:40 to 100: 0 in terms of mass.

  The above-mentioned resol: novolac content ratio is, for example, 60:40 to 100: 0, more preferably 70:30 to 100: 0, and further preferably 80:20 to 100: 0. By thus increasing the content ratio of the resol-type phenol resin in the phenol resin, the rapid curing property of the encapsulating resin composition can be enhanced. Thereby, temperature cycle resistance can be improved.

The encapsulating resin composition of the present embodiment contains an inorganic filler.
Examples of the inorganic filler include talc, calcined clay, uncalcined clay, mica, titanium oxide, alumina, silica, calcium carbonate, aluminum hydroxide, magnesium hydroxide, barium sulfate, calcium sulfate, calcium sulfite, zinc borate. , Barium metaborate, aluminum borate, calcium borate, sodium borate, aluminum nitride, boron nitride, silicon nitride and the like are used. These may be used alone or in combination of two or more.

From the viewpoint of fluidity, the above-mentioned inorganic filler can contain silica particles having an average particle diameter d50 of, for example, 3 μm or more and 50 μm or less. As the silica particles, spherical silica or crushed silica is used. These may be used alone or in combination of two or more.
The average particle diameter d50 of the silica particles is, for example, 3 μm to 50 μm, preferably 5 μm to 40 μm, and more preferably 10 μm to 30 μm. By setting the appropriate average particle diameter d50, the filling property of the sealing resin composition in the narrow region can be improved.

  In the present specification, “to” indicates that the upper limit and the lower limit are included unless otherwise specified.

The average particle diameter d50 can be measured by a laser diffraction type particle size distribution measuring device, and means the median diameter (D ₅₀ ) when the particle size distribution of particles is measured on a volume basis.

  From the viewpoint of low cost, the above-mentioned inorganic filler may include calcium carbonate or the like as an inorganic filler whose cost is relatively low.

  The content of the calcium carbonate is, for example, 5% by mass to 40% by mass, preferably 8% by mass to 30% by mass, more preferably 10% by mass to 25% by mass with respect to the entire inorganic filler (100% by mass). %.

It is preferable that the inorganic filler does not substantially contain a fibrous filler such as glass fiber. This can prevent the fluidity of the encapsulating resin composition from decreasing. As a result, the filling property in the narrow region can be improved.
The term "substantially free" means that the content with respect to the entire inorganic filler (100% by mass) is 0.1% by mass or less, preferably 0% by mass or less.

  The content of the inorganic filler is, for example, 50% by mass to 85% by mass, preferably 60% by mass to 83% by mass, more preferably 63 to 72% by mass, based on the entire solid content of the encapsulating resin composition. %. By setting the content of the inorganic filler to be the above lower limit or more, it is possible to suppress the variation in the linear expansion coefficient of the As molded body. Even when the content of the inorganic filler is not more than the upper limit value, an increase in the variation of the linear expansion coefficient of the As molded body can be suppressed by increasing the content ratio of the phenol resin in the thermosetting resin.

The encapsulating resin composition may include a curing accelerator, if necessary.
An amine-based curing agent can be used as the curing accelerator.
Examples of the amine-based curing agent include ethylenediamine (EDA), diethylenetriamine (DETA), triethylenetetramine (TETA), mensendiamine (MDA), 4,4-diaminodiphenylmethane (DDM), and metaphenylenediamine (DPDA). , Diaminodiphenylsulfone (DDS), triethylamine, benzyldimethylamine, 1,8-diazabiscyclo (5,4,0) undecene-1 (DBU), pyrazole, benzotriazole, triazole and the like. In addition, 2-methylimidazole, 2-undecylimidazole, 2-ethyl-4-methylimidazole, 2-phenyl-4-methylimidazole, 2,4'-diamino-6- [2'-ethyl-4'-methyl Imidazole compounds such as imidazolyl- (1 ′)] ethyl-s-triazine, 2-methylimidazole / isocyanuric acid adduct, 2-methylimidazole / trimellitic acid adduct are used. These may be used alone or in combination of two or more.

  The content of the curing accelerator is, for example, 0.01% by mass to 3% by mass, preferably 0.05% by mass to 2% by mass, and more preferably, the total solid content of the encapsulating resin composition. It is 0.1 to 1 mass%.

The encapsulating resin composition may include a curing aid.
Magnesium oxide, calcium hydroxide or the like is used as the curing accelerator. These may be used alone or in combination of two or more.

  The content of the curing aid is, for example, 0.01% by mass to 3% by mass, preferably 0.05% by mass to 2% by mass, and more preferably, the total solid content of the encapsulating resin composition. It is 0.1 to 1 mass%.

The encapsulating resin composition may include a release agent.
As the releasing agent, for example, natural wax such as carnauba wax, synthetic wax such as montanic acid ester wax, higher fatty acid such as zinc stearate and metal salts thereof, and paraffin can be used.

  The content of the release agent is, for example, 0.1% by mass to 3% by mass, preferably 0.3% by mass to 2% by mass, based on the entire solid content of the encapsulating resin composition.

The encapsulating resin composition may include a silane coupling agent.
Examples of the silane coupling agent include epoxy group-containing alkoxys such as γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, and β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane. Silane compounds; mercapto group-containing alkoxysilane compounds such as γ-mercaptopropyltrimethoxysilane and γ-mercaptopropyltriethoxysilane; γ-ureidopropyltriethoxysilane, γ-ureidopropyltrimethoxysilane, γ- (2-ureidoethyl) ) Ureido group-containing alkoxysilane compounds such as aminopropyltrimethoxysilane; γ-isocyanatopropyltriethoxysilane, γ-isocyanatopropyltrimethoxysilane, γ-isocyanatopropylmethyldimethoxy. Isocyanato group-containing alkoxysilane compounds such as silane, γ-isocyanatopropylmethyldiethoxysilane, γ-isocyanatopropylethyldimethoxysilane, γ-isocyanatopropylethyldiethoxysilane, γ-isocyanatopropyltrichlorosilane; γ-amino Amino group-containing alkoxysilane compounds such as propyltriethoxysilane, γ- (2-aminoethyl) aminopropylmethyldimethoxysilane, γ- (2-aminoethyl) aminopropyltrimethoxysilane, γ-aminopropyltrimethoxysilane; γ Examples thereof include a hydroxyl group-containing alkoxysilane compound such as -hydroxypropyltrimethoxysilane and γ-hydroxypropyltriethoxysilane. These may be used alone or in combination of two or more.

  The content of the silane coupling agent is, for example, 0.05% by mass to 2% by mass, and preferably 0.1% by mass to 1% by mass, based on the entire solid content of the encapsulating resin composition.

The encapsulating resin composition may include a pigment.
As the pigment, for example, carbon black or nigrosine can be used.

  The content of the pigment is, for example, 0.05% by mass to 2% by mass, preferably 0.1 to 1.5% by mass, based on the entire solid content of the encapsulating resin composition.

  The encapsulating resin composition of the present embodiment can include components other than the components described above.

  Examples of the other components include organic fillers, flame retardants, weathering agents, antioxidants, plasticizers, lubricants, sliding agents, and foaming agents. These may be used alone or in combination of two or more.

  Examples of the method for preparing the encapsulating resin composition of the present embodiment include a method in which the components are mixed and then the resulting mixture is finely pulverized under a certain condition by a rotary ball mill. It is also possible to control the conditions of the melt-kneading step after fine pulverization with a rotary ball mill, to continuously perform the processes from the mixing of the components to the melt-kneading, and the like. The method for preparing the encapsulating resin composition is not limited to the above.

<In-vehicle electronic control unit 10>
The wiring board 12 has a connection terminal 18 for connecting to the outside on at least one side. The vehicle-mounted electronic control device 10 according to the example of the present embodiment is electrically connected to the counterpart connector via the connection terminal 18 by fitting the connection terminal 18 and the counterpart connector.

  The wiring board 12 is, for example, a wiring board provided with circuit wiring on one or both of one surface and the other surface opposite to the one surface. As shown in FIG. 1, the wiring board 12 has, for example, a flat plate shape. In the present embodiment, an organic substrate formed of an organic material such as polyimide can be used as the wiring substrate 12. The wiring board 12 may have, for example, a through hole 120 penetrating the wiring board 12 to connect one surface to the other surface. In this case, the wiring provided on one surface of the wiring board 12 and the wiring provided on the other surface are electrically connected via the conductor pattern provided in the through hole 120.

The wiring board 12 has a solder resist layer on one surface on which the electronic component 16 is mounted, for example. The solder resist layer can be formed using a resin composition for forming a solder resist that is commonly used in the field of semiconductor devices. In the present embodiment, for example, a solder resist layer can be provided on one surface and the other surface of the wiring board 12.
The solder resist layer provided on one surface of the wiring board 12 or on both the one surface and the other surface is formed of, for example, a resin composition containing a silicone compound. This makes it possible to realize a solder resist layer having excellent surface smoothness.

  As shown in FIG. 1, the plurality of electronic components 16 are mounted on one surface and the other surface of the wiring board 12, for example. On the other hand, the electronic component 16 may be provided only on one surface of the wiring board 12 and may not be provided on the other surface of the wiring board 12. The electronic component 16 is not particularly limited as long as it can be mounted in an on-vehicle electronic control device, and examples thereof include a microcomputer.

  The encapsulating resin member 14 is formed by molding and curing the encapsulating resin composition so as to encapsulate the electronic component 16. In the present embodiment, the sealing resin member 14 is formed so as to seal the wiring board 12 together with the electronic component 16, for example. In the example shown in FIG. 1, the sealing resin member 14 is provided so as to seal the one surface and the other surface of the wiring board 12 and the electronic component 16 mounted on the wiring board 12. The sealing resin member 14 is formed so as to seal a part or the whole of the wiring board 12, for example. In FIG. 1, a case where the sealing resin member 14 is provided so that the connection terminals 18 are exposed and the connection terminals 18 of the wiring board 12 are not sealed but the other portions are entirely sealed is illustrated. ing.

  In the vehicle-mounted electronic control device 10 according to the present embodiment, the wiring board 12 may be mounted on, for example, a metal base. The metal base can function as a heat sink for radiating heat generated from the electronic component 16, for example. In the present embodiment, for example, the vehicle-mounted electronic control unit 10 is formed by integrally molding the metal base and the wiring board 12 mounted on the metal base with the resin composition for sealing. You can The metal material forming the metal base is not particularly limited, but may include, for example, iron, copper, and aluminum, and an alloy containing one or more of these, and the like. The vehicle-mounted electronic control device 10 may not have a metal base.

  Although the embodiments of the present invention have been described above, these are examples of the present invention, and various configurations other than the above can be adopted.

  Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited to the description of these examples.

<Preparation of resin composition for sealing>
First, according to the formulation shown in Table 1, each component was premixed for 20 minutes with a Henschel mixer (volume 200 liters, rotation speed 900 rpm) set to a room temperature state. Then, using a continuous rotary ball mill (Nippon Coke Kogyo Co., Ltd. dynamic mill MYD25, screw rotation speed 500 rpm, alumina ball diameter 10 mm, volume filling rate of balls 50% with respect to apparatus volume) of the obtained mixture, The material was finely pulverized at a material supply rate of 200 kg / hr while maintaining the material temperature at 30 ° C or lower. Next, the finely pulverized mixture is melt-kneaded using a single-screw extrusion kneader (screw diameter D = 46 mm, extruder length = 500 mm, melt-kneading section length = 7 D, screw rotation speed 200 rpm, discharge rate 30 kg / hr). did. Then, the mixture after kneading was cooled and pulverized to obtain a sealing resin composition. The steps from premixing with a Henschel mixer to obtaining the encapsulating resin composition were continuously performed.

(Thermosetting resin)
-Resol type phenol resin 1: Resol type phenol resin (Sumitomo Bakelite Co., Ltd., R-25)
-Resol type phenol resin 2: Resol type phenol resin (Sumitomo Bakelite Co., PR-51723)
-Novolak-type phenol resin 1: Novolac-type phenol resin (Sumitomo Bakelite, PR-51470)
-Novolak type phenol resin 2: Novolac type phenol resin (Sumitomo Bakelite Co., A-1087)
Epoxy resin 1: Ortho-cresol novolac type epoxy resin (Epiclon N-670 manufactured by DIC)
Epoxy resin 2: Orthocresol novolac type epoxy resin (DIC, EPICLON N-695)

(Curing aid)
・ Hardening aid 1: Slaked lime (made by Chichibu Lime Company)
(Curing accelerator)
-Curing acceleration 1: 2-phenyl-4-methylimidazole (2P4MZ, manufactured by Shikoku Chemicals Co., Ltd.)

(Inorganic filler)
Inorganic filler 1: Spherical silica (FB-950, manufactured by Denki Kagaku Kogyo Co., Ltd., average particle diameter D ₅₀ = 26 μm)
Inorganic filler 2: crushed silica (manufactured by Tatsumori, RD-8, average particle size D ₅₀ = 15 μm)
・ Inorganic filler 3: Calcium carbonate (made by Nitto Koka Co., Ltd.)

(Additive)
-Release agent 1: montanic acid ester wax (Recolove WE-4, manufactured by Clariant Japan)
・ Silane coupling agent 1: γ-aminopropyltriethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., KBE-903)
・ Pigment 1: Carbon black (# 5 manufactured by Mitsubishi Chemical Corporation)

(Coefficient of linear expansion: α _As , α _E )
The obtained resin composition for encapsulation was die-molded under molding conditions of 175 ° C. for 3 minutes to prepare an as-molded test piece of length × width × thickness: 10 mm × 80 mm × 4 mmt. In the flow direction from the center of the surface of the obtained as-molded test piece, using a thermomechanical analyzer (manufactured by Seiko Instruments Inc., product name: TMA / SS-6000), a temperature rise of 5 ° C./min, 40 The average linear expansion coefficient when measured under the condition of the temperature range of ° C to 150 ° C was defined as α _As (ppm / ° C).
Further, the obtained as-molded test piece was subjected to a post-curing treatment under a curing condition of 180 ° C. for 8 hours to prepare a post-curing test piece. Using a thermomechanical analyzer (manufactured by Seiko Instruments Inc., product name: TMA / SS-6000) in the flow direction from the center of the surface of the obtained post-cured test piece, the temperature was raised at 5 ° C / min, 40 ° C. The average coefficient of linear expansion when measured in the temperature range of 150 to 150 ° C was defined as α _E (ppm / ° C).
Using the measured α _E and α _As , the difference (α _As −α _E ) in the average linear expansion coefficient from 40 ° C. to 150 ° C. was calculated. The results are shown in Table 1.

(Lab torque: minimum torque, T ₁ )
Using a Labo Plastomill (4C150, manufactured by Toyo Seiki Seisaku-sho, Ltd.), the torque value of the obtained sealing resin composition was measured with time under the conditions of a rotation speed of 30 rpm and a measurement temperature of 150 ° C.
As shown in FIG. 2, the measurement starting point of the Labo Plastomill measurement is P ₁ , the point at which the torque value is the minimum torque value is P _3, and the torque value is the minimum torque value between P ₁ and P ₃ . The point at which the torque value doubles is P _2, and the point at which the torque value becomes twice the minimum torque value after P ₃ is P ₄ .
The measurement start point P ₁ of the Labo Plastomill measurement was the point where the torque was started to drop after the material was put into the Labo Plastomill and the torque rapidly rose. The time from P ₃ to P _4, the torque value is set to 2 times or less than a time T ₁ of the minimum torque value. The results are shown in Table 1. The unit of the time T ₁ is second, and the unit of the minimum torque value is N · m.

<Evaluation of filling property>
A substrate obtained by printing and curing a solder resist (manufactured by Tamura Corporation, DSR-2200S66-11) on a glass epoxy copper clad laminate (manufactured by Panasonic Corporation, R-1705, substrate thickness 1.6 mm) ( (Length 130 mm, width 80 mm), using the sealing resin composition obtained above, a TOWA YPS-120ton manual press with a mold temperature of 175 ° C., an injection time of 20 seconds, an injection pressure of 8.4 MPa, Sealing molding was carried out under the condition that the curing time was 120 seconds to obtain a molded product. The sealing resin portion of the molded product had a length of 120 mm, a width of 90 mm, and a thickness of 9.6 mm, and up to 115 mm in height of the substrate was enclosed in the sealing resin, and 15 mm in length of the substrate was exposed from one side. The resin thickness on both the upper surface side and the lower surface side of the substrate was 4 mm.
The appearance of the obtained molded body was visually observed to confirm the presence or absence of unfilling by welding. Then, the filling property was evaluated as × when the unfilled portion was 1 mm or more and as ◯ when the unfilled portion was less than 1 mm.

<Temperature cycle test>
A molded body produced in the same manner as the above filling property evaluation was subjected to 2000 cycles in a temperature cycle test (-40 ° C 30 minutes, 150 ° C 30 minutes, 1 cycle 1 hour), and then FineSAT manufactured by Hitachi Power Solutions Co., Ltd. At that point, ultrasonic flaw detection was performed again. Then, the occurrence of new peeling or the progress of peeling was confirmed.
Here, the evaluation by the temperature cycle test was performed as × if there was new peeling or progress of peeling, and as ○ if there was no new peeling or progress of peeling.

  It was found that the encapsulating resin compositions of Examples 1 to 4 were superior in temperature cycle resistance to Comparative Examples 1 to 4 and superior to Comparative Example 3 in filling property.

10 In-vehicle electronic control device 12 Wiring board 14 Sealing resin member 16 Electronic component 18 Connection terminal 120 Through hole

Claims (12)

A wiring board, a plurality of electronic components mounted on at least one surface of the wiring board, and a sealing resin member for sealing the plurality of electronic components, the sealing resin member in an in-vehicle electronic control device A sealing resin composition used for forming,
A thermosetting resin,
Including an inorganic filler,
The difference (α _As −α _E ) between the average linear expansion coefficients of 40 ° C. to 150 ° C., which is represented by α _E and α _As measured in the following procedure A, is 0 or more and 6.0 or less,
The time T ₁ when the torque value of the encapsulating resin composition is twice the minimum torque value or less, which is measured in the following procedure B, is 5 seconds or more and 50 seconds or less, and the encapsulating resin composition A sealing resin composition having a minimum torque value of 0.5 N · m or more and 4.5 N · m or less.
(Procedure A)
Using the encapsulating resin composition, a die molding is performed under molding conditions of 175 ° C. for 3 minutes to prepare an as-molded test piece of length × width × thickness: 10 mm × 80 mm × 4 mmt. The average line when measured in a flow direction from the center of the surface of the obtained as-molded test piece using a thermomechanical analyzer under conditions of a temperature increase of 5 ° C./min and a temperature range of 40 ° C. to 150 ° C. Let the expansion coefficient be α _As (ppm / ° C.).
The obtained as-molded test piece is subjected to a post-curing treatment under a curing condition of 180 ° C. for 8 hours to prepare a post-curing test piece. Average line when measured in the flow direction from the center of the surface of the obtained post-curing test piece using a thermomechanical analyzer under conditions of a temperature increase of 5 ° C./min and a temperature range of 40 ° C. to 150 ° C. Let the expansion coefficient be α _E (ppm / ° C.).
(Procedure B)
Using a Labo Plastomill, the torque value of the encapsulating resin composition is measured over time under the conditions of a rotation speed of 30 rpm and a measurement temperature of 150 ° C.
The measurement start point of the Labo Plastomill measurement is P ₁ , the point where the torque value is the minimum torque value is P _3, and the point where the torque value is twice the minimum torque value between P ₁ and P ₃ is P. _2, and the point where the torque value becomes twice the minimum torque value after passing P ₃ is P ₄ .
The measurement start point P ₁ of the Laboplast mill measurement is a point at which the material is put into the Laboplast mill and the torque rises sharply and then the torque starts to fall.
The time from P ₃ to P ₄ is defined as time T ₁ when the torque value is twice the minimum torque value or less. The encapsulating resin composition according to claim 1, wherein
A resin composition for encapsulation, wherein the thermosetting resin contains a phenol resin. The encapsulating resin composition according to claim 2,
A resin composition for encapsulation, wherein the phenol resin contains a resol-type phenol resin. The encapsulating resin composition according to claim 3, wherein
The encapsulating resin composition, wherein the content of the resol-type phenolic resin is 60% by mass or more and 100% by mass or less based on the whole phenolic resin. The resin composition for sealing according to any one of claims 1 to 4,
A resin composition for encapsulation, wherein the inorganic filler contains calcium carbonate. The resin composition for sealing according to any one of claims 1 to 5,
A resin composition for encapsulation, wherein the inorganic filler does not contain glass fiber. The encapsulating resin composition according to any one of claims 1 to 6,
The encapsulating resin composition, wherein the inorganic filler contains silica particles, and the average particle diameter d50 of the silica particles is 3 μm or more and 50 μm or less. The encapsulating resin composition according to any one of claims 1 to 7,
A resin composition for encapsulation containing a curing accelerator. The encapsulating resin composition according to any one of claims 1 to 8,
A resin composition for encapsulation containing a release agent. The resin composition for sealing according to any one of claims 1 to 9,
A sealing resin composition containing a silane coupling agent. The resin composition for sealing according to any one of claims 1 to 10,
A sealing resin composition containing a pigment. Wiring board,
A plurality of electronic components mounted on at least one surface of the wiring board,
An in-vehicle electronic control device comprising: a sealing resin member that seals the plurality of electronic components,
An in-vehicle electronic control device, wherein the encapsulating resin member is composed of a molded body of the encapsulating resin composition according to any one of claims 1 to 11.

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