JP2017188647A - Electronic circuit package arranged by using composite magnetic sealing material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic circuit package arranged by using a composite magnetic sealing material with a low thermal expansion coefficient as a mold material.SOLUTION: An electronic circuit package disclosed herein comprises: a substrate; an electronic component mounted on a surface of the substrate; and a magnetic mold resin which covers the surface of the substrate so as to bury the electronic component. The magnetic mold resin includes a resin material; and a filler blended in the resin material, of which the blend percentage is 30-85 vol.%. The filler comprises a magnetic filler including Fe and 32-39 wt% of a metal material including Ni as a primary component. Thus, the thermal expansion coefficient of the magnetic mold resin becomes 15 ppm/°C or less.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an electronic circuit package, and more particularly to an electronic circuit package using a composite magnetic material as a molding material.

  In recent years, electronic devices such as smartphones employ high-performance wireless communication circuits and digital chips, and the operating frequency of semiconductor ICs used tends to increase. In addition, system-in-package (SIP) with a 2.5D structure or a 3D structure for connecting a plurality of semiconductor ICs with the shortest wiring is accelerated, and modularization of power supply system circuits is expected to increase in the future. In addition, many electronic components (passive components such as inductors, capacitors, resistors, and filters, active components such as transistors and diodes, integrated circuit components such as semiconductor ICs, and other components necessary for electronic circuit configuration) are modularized. The number of electronic circuit modules that have been used is expected to increase in the future, and electronic circuit packages that collectively refer to these electronic circuit modules tend to be mounted with high density due to higher functionality, smaller size, and thinner electronic devices such as smartphones. These tendencies indicate that malfunctions and radio interference due to noise are conspicuous, and it is difficult to prevent malfunctions and radio interference with conventional noise countermeasures. Therefore, in recent years, self-shielding of electronic circuit packages has progressed, and electromagnetic shielding has been proposed and put to practical use by conductive paste, plating, or sputtering, but higher shield characteristics will be required in the future.

  In order to realize this, in recent years, an electronic circuit package in which a molding material itself has a magnetic shield characteristic has been proposed. For example, Patent Document 1 discloses a composite magnetic sealing material to which a soft magnetic powder having an oxide film is added as a mold material for an electronic circuit package.

  However, the conventional composite magnetic sealing material has a problem that the coefficient of thermal expansion is large. For this reason, a mismatch in thermal expansion coefficient occurs between the composite magnetic sealing material and the package substrate or electronic component, resulting in a large warp in the state of the aggregate substrate having a strip shape after molding, or individualization In some cases, the electronic circuit package may have a large warp that causes a problem in connectivity during mounting reflow. Hereinafter, this phenomenon will be described.

  In recent years, various structures have been proposed and put into practical use for semiconductor packages and electronic component modules, but the current mainstream is mounting electronic components such as semiconductor ICs on an organic multilayer substrate, and the upper and surrounding areas are mounted. A structure molded with a resin sealing material is common. A semiconductor package or an electronic component module having such a structure is manufactured by individualization processing such as dicing after being molded in a state of a collective substrate.

  In this structure, since the organic multilayer substrate and the resin sealing material having different physical properties constitute a so-called bimetal, warping occurs due to factors such as a difference in thermal expansion coefficient, glass transition, and curing shrinkage of the mold material. In order to suppress this, it is necessary to match physical properties such as a thermal expansion coefficient as much as possible. In recent years, organic multilayer substrates used for semiconductor packages and electronic circuit modules tend to be increasingly thinner and multilayered due to the demand for low profile. In order to achieve high rigidity and low thermal expansion to ensure handling of thin substrates while achieving this, substrate materials with a high glass transition temperature are used, or fillers with a low coefficient of thermal expansion are added to the substrate material. Or glass cloth having a lower coefficient of thermal expansion is generally used.

  On the other hand, since a physical property difference between the semiconductor IC and electronic component mounted on the substrate and the molding material also generates stress, various problems such as interfacial peeling of the molding material and cracking of the electronic component and the molding material are caused. Silicon is used for semiconductor ICs, but the thermal expansion coefficient of silicon is 3.5 ppm / ° C., and the thermal expansion coefficient of sintered chip components such as ceramic capacitors and inductors is about 10 ppm / ° C.

  For this reason, the molding material is also required to have a low thermal expansion, and a material that cuts off 10 ppm / ° C. is commercially available. As a method of reducing the thermal expansion of the molding material, not only the use of a low thermal expansion epoxy resin but also a method of blending fused silica with a very low thermal expansion coefficient of 0.5 ppm / ° C. into the sealing resin at a high filling rate. It is used.

JP-A-10-64714

  On the other hand, a general magnetic material has a high coefficient of thermal expansion. For this reason, as described in Patent Document 1, a composite magnetic sealing material in which a general soft magnetic powder is added to a mold resin has a problem that it cannot achieve a desired low thermal expansion coefficient. It was.

  Therefore, an object of the present invention is to provide an electronic circuit package using a composite magnetic sealing material having a low thermal expansion coefficient as a molding material.

  An electronic circuit package according to the present invention includes a substrate, an electronic component mounted on the surface of the substrate, and a magnetic mold resin that covers the surface of the substrate so as to embed the electronic component, and the magnetic mold resin includes: A resin material and a filler that is blended in the resin material and has a blending ratio of 30 to 85% by volume, and the filler contains 32 to 39% by weight of a metal material mainly composed of Ni in Fe. Including a filler, whereby the thermal expansion coefficient of the magnetic mold resin is 15 ppm / ° C. or less.

  According to the present invention, since the magnetic filler having a low thermal expansion coefficient is used, the thermal expansion coefficient of the magnetic mold resin made of the composite magnetic sealing material can be made 15 ppm / ° C. or less. For this reason, it becomes possible to prevent warping of the substrate, interface peeling of the molding material, cracking of the molding material, and the like.

  In the present invention, the metal material may further contain 0.1 to 8% by weight of Co with respect to the entire magnetic filler. According to this, it becomes possible to further reduce the thermal expansion coefficient of the magnetic mold resin made of the composite magnetic sealing material.

In the present invention, the filler may further contain a nonmagnetic filler. According to this, it becomes possible to further reduce the thermal expansion coefficient of the magnetic mold resin made of the composite magnetic sealing material. In this case, it is preferable that the quantity of the said nonmagnetic filler with respect to the sum total of the said magnetic filler and the said nonmagnetic filler is 1-40 volume%. According to this, it becomes possible to further reduce the thermal expansion coefficient of the magnetic mold resin made of the composite magnetic sealing material while ensuring sufficient magnetic properties. In this case, the nonmagnetic filler is selected from the group consisting of SiO ₂ , ZrW ₂ O ₈ , (ZrO) ₂ P ₂ O ₇ , KZr ₂ (PO ₄ ) ₃ and Zr ₂ (WO ₄ ) (PO ₄ ) _2. It is preferable to include at least one selected material. Since these materials have a very low coefficient of thermal expansion or have a negative value, it is possible to further reduce the coefficient of thermal expansion of the magnetic mold resin made of the composite magnetic sealing material.

  In the present invention, the magnetic filler preferably has a substantially spherical shape. According to this, it becomes possible to increase the ratio of the magnetic filler in the composite magnetic sealing material.

In the present invention, the surface of the magnetic filler is preferably coated with an insulating coating, and the thickness of the insulating coating is more preferably 10 nm or more. According to this, the volume resistivity of the magnetic mold resin made of the composite magnetic sealing material can be increased to, for example, 10 ¹⁰ Ω · cm or more, and the insulating characteristics required for the mold material for the electronic circuit package can be ensured. It becomes possible.

  In the present invention, the resin material is preferably a thermosetting resin material, and the thermosetting resin material is at least one selected from the group consisting of epoxy resins, phenol resins, urethane resins, silicone resins, and imide resins. Preferably one material is included.

  The electronic circuit package according to the present invention may further include a nonmagnetic member provided between the electronic component and the magnetic mold resin. According to this, the fluctuation | variation of the characteristic of an electronic component by the electronic component and magnetic mold resin adjoining can be suppressed.

  The electronic circuit package according to the present invention preferably further includes a metal film that is connected to a power supply pattern provided on the substrate and covers the magnetic mold resin. According to this, it becomes possible to obtain a composite shield structure having both an electromagnetic shield function and a magnetic shield function.

  In this case, the metal film is preferably mainly composed of at least one metal selected from the group consisting of Au, Ag, Cu and Al, and the surface of the metal film is covered with an anti-oxidation coating. Is more preferable. Preferably, the power supply pattern is exposed on a side surface of the substrate, and the metal film is in contact with the power supply pattern exposed on the side surface of the substrate. According to this, the metal film can be easily and reliably connected to the power supply pattern.

  As described above, the electronic circuit package according to the present invention uses the magnetic mold resin having a small thermal expansion coefficient as the molding material. Therefore, while ensuring the magnetic shielding characteristics, the substrate warpage, the mold material interface peeling, the molding material. It is possible to prevent cracks and the like.

FIG. 1 is a cross-sectional view showing a configuration of an electronic circuit package according to a first embodiment of the present invention. FIG. 2 is a cross-sectional view showing a configuration of an electronic circuit package according to a modification of the first embodiment. FIG. 3 is a process diagram for explaining a method of manufacturing the electronic circuit package shown in FIG. FIG. 4 is a process diagram for explaining a method of manufacturing the electronic circuit package shown in FIG. FIG. 5 is a process diagram for explaining a method of manufacturing the electronic circuit package shown in FIG. FIG. 6 is a schematic diagram for explaining the configuration of the composite magnetic sealing material. FIG. 7 is a graph showing the relationship between the Ni ratio of the magnetic filler and the thermal expansion coefficient and permeability of the composite magnetic sealing material. FIG. 8 is a graph showing the relationship between the Ni ratio of the magnetic filler and the thermal expansion coefficient of the composite magnetic sealing material. FIG. 9 is a graph showing the relationship between the Ni ratio of the magnetic filler and the magnetic permeability of the composite magnetic sealing material. FIG. 10 is a graph showing the relationship between the Co ratio of the magnetic filler, the thermal expansion coefficient, and the magnetic permeability of the composite magnetic sealing material. FIG. 11 is a graph showing the relationship between the addition ratio of the nonmagnetic filler and the thermal expansion coefficient of the composite magnetic sealing material. FIG. 12 is a graph showing the relationship between the presence or absence of an insulating coat formed on the surface of the magnetic filler and the volume resistivity. FIG. 13 is a graph showing the relationship between the film thickness of the insulating coat formed on the surface of the magnetic filler and the volume resistivity. FIG. 14 is a graph showing the relationship between the volume resistivity of the magnetic filler and the volume resistivity of the composite magnetic sealing material. FIG. 15 is a cross-sectional view showing the configuration of the electronic circuit package according to the second embodiment of the present invention. FIG. 16 is a process diagram for explaining a method of manufacturing the electronic circuit package shown in FIG. FIG. 17 is a process diagram for explaining a method of manufacturing the electronic circuit package shown in FIG. FIG. 18 is a process diagram for explaining a method of manufacturing the electronic circuit package shown in FIG. FIG. 19 is a cross-sectional view showing a configuration of an electronic circuit package according to the third embodiment of the present invention. FIG. 20 is a cross-sectional view illustrating a configuration of an electronic circuit package according to a first modification of the third embodiment. FIG. 21 is a cross-sectional view illustrating a configuration of an electronic circuit package according to a second modification of the third embodiment. FIG. 22 is a cross-sectional view illustrating a configuration of an electronic circuit package according to a third modification of the third embodiment. FIG. 23 is a cross-sectional view illustrating a configuration of an electronic circuit package according to a fourth modification of the third embodiment. FIG. 24 is a graph showing noise attenuation of the electronic circuit package shown in FIG. FIG. 25 is a graph showing the relationship between the thickness of the metal film included in the electronic circuit package shown in FIG. 19 and the amount of noise attenuation. FIG. 26 is a graph showing the relationship between the thickness of the metal film included in the electronic circuit package shown in FIG. 19 and the amount of noise attenuation. FIG. 27 is a graph showing the relationship between the thickness of the metal film included in the electronic circuit package shown in FIG. 19 and the amount of noise attenuation. FIG. 28 is a graph showing the amount of warpage of the substrate when the electronic circuit package shown in FIGS. 1 and 19 is heated and lowered. FIG. 29 is a graph showing the amount of warping of the substrate when the temperature of the electronic circuit package in the comparative example is raised and lowered. FIG. 30 is a sectional view showing the configuration of an electronic circuit package according to the fourth embodiment of the present invention. FIG. 31 is a process diagram for describing a method of manufacturing the electronic circuit package shown in FIG. FIG. 32 is a process diagram for describing a method of manufacturing the electronic circuit package shown in FIG. FIG. 33 is a table showing Composition 1 to Composition 3. FIG. 34 is a table showing the measurement results of the examples. FIG. 35 is a table showing measurement results of the examples.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

<First Embodiment>
FIG. 1 is a cross-sectional view showing a configuration of an electronic circuit package 11A according to the first embodiment of the present invention.

  As shown in FIG. 1, the electronic circuit package 11 </ b> A according to the present embodiment includes a substrate 20, a plurality of electronic components 31 and 32 mounted on the substrate 20, and a surface 21 of the substrate 20 so as to embed the electronic components 31 and 32. And a magnetic mold resin 40 for covering.

  The type of electronic circuit package 11A according to the present embodiment is not particularly limited. For example, a high-frequency module that handles high-frequency signals, a power supply module that performs power supply control, and a system-in-package (SIP) having a 2.5D structure or a 3D structure. And semiconductor packages for wireless communication or digital circuits. In FIG. 1, only two electronic components 31 and 32 are illustrated, but actually, more electronic components are incorporated.

  The substrate 20 has a double-sided and multilayer wiring structure in which a large number of wirings are embedded therein, and is a thermosetting resin-based organic substrate such as FR-4, FR-5, BT, cyanate ester, phenol, imide, There is no limitation on the type of organic substrate such as liquid crystal polymer based thermoplastic resin, LTCC substrate, HTCC substrate, and flexible substrate. In the present embodiment, the substrate 20 has a four-layer structure, and has a wiring layer formed on the front surface 21 and the back surface 22 of the substrate 20 and two wiring layers embedded inside. A plurality of land patterns 23 are formed on the surface 21 of the substrate 20. The land pattern 23 is an internal electrode for connecting to the electronic components 31 and 32, and both are electrically and mechanically connected via solder 24 (or conductive paste). As an example, the electronic component 31 is a semiconductor chip such as a controller, and the electronic component 32 is a passive component such as a capacitor or a coil. A part of the electronic component (for example, a thinned semiconductor chip) may be embedded in the substrate 20.

  The land pattern 23 is connected to an external terminal 26 formed on the back surface 22 of the substrate 20 via an internal wiring 25 formed inside the substrate 20. In actual use, the electronic circuit package 11A is mounted on a motherboard (not shown) or the like, and the land pattern on the motherboard and the external terminal 26 of the electronic circuit package 11A are electrically connected. The material of the conductor constituting the land pattern 23, the internal wiring 25, and the external terminal 26 may be a metal such as copper, silver, gold, nickel, chromium, aluminum, palladium, indium, or a metal alloy thereof, or a resin. However, when the substrate 20 is an organic substrate or a flexible substrate, copper or silver is preferably used from the viewpoints of cost, conductivity, and the like. As a method for forming these conductive materials, methods such as printing, plating, foil lamination, sputtering, vapor deposition, and ink jet can be used.

The magnetic mold resin 40 is provided so as to cover the surface 21 of the substrate 20 so as to embed the electronic components 31 and 32. The magnetic mold resin 40 is a mold member and also functions as a magnetic shield. In the present embodiment, the side surface 42 of the magnetic mold resin 40 and the side surface 27 of the substrate 20 constitute the same plane. Although details of the magnetic mold resin 40 will be described later, the magnetic mold resin 40 is made of a composite magnetic sealing material having a very small coefficient of thermal expansion (for example, 15 ppm / ° C. or less) as compared with the conventional magnetic mold resin. Since the magnetic mold resin 40 is in contact with the electronic components 31 and 32 and the land pattern 23, the volume resistivity needs to be sufficiently high, and specifically, is preferably 10 ¹⁰ Ω · cm or more.

  Note that when the electronic component such as a high-frequency inductor is too close to the magnetic mold resin 40, characteristics such as an inductance value may fluctuate from a design value. In such a case, it is possible to reduce fluctuations in characteristics by covering a part or all of the electronic component with a nonmagnetic member. FIG. 2 is a cross-sectional view showing a configuration of an electronic circuit package 11B according to a modification, which is different from the electronic circuit package 11A shown in FIG. 1 in that the electronic component 32 is covered with a nonmagnetic member 50. . As the nonmagnetic member 50, a general resin can be used. If such a non-magnetic member 50 is interposed between the electronic component 32 and the magnetic mold resin 40, the distance between the electronic component 32 and the magnetic mold resin 40 is increased, so that fluctuations in characteristics such as inductance values are reduced. It becomes possible.

  Next, the method for manufacturing the electronic circuit package 11A according to the present embodiment will be described.

  3 to 5 are process diagrams for explaining a method of manufacturing the electronic circuit package 11A.

  First, as shown in FIG. 3, an aggregate substrate 20A having a multilayer wiring structure is prepared. A plurality of land patterns 23 are formed on the front surface 21 of the collective substrate 20A, and a plurality of external terminals 26 are formed on the back surface 22 of the collective substrate 20A. A plurality of internal wirings 25 are formed on the inner layer of the collective substrate 20A. 3 indicates a portion to be cut in the subsequent dicing process.

  Next, as shown in FIG. 3, a plurality of electronic components 31 and 32 are mounted on the surface 21 of the collective substrate 20 </ b> A so as to be connected to the land pattern 23. Specifically, after supplying the solder 24 on the land pattern 23, the electronic components 31, 32 are mounted and the reflow is performed to connect the electronic components 31, 32 to the land pattern 23.

  Next, as shown in FIG. 4, the surface 21 of the collective substrate 20 </ b> A is covered with a magnetic mold resin 40 so as to embed the electronic components 31 and 32. As a method for forming the magnetic mold resin 40, transfer molding, compression molding, injection molding, casting, vacuum casting, dispensing, a method using a slit nozzle, or the like can be used.

  Then, as shown in FIG. 5, if the substrate 20 is separated by cutting the collective substrate 20A along the broken line a, the electronic circuit package 11A according to the present embodiment is completed.

  Next, the composite magnetic sealing material constituting the magnetic mold resin 40 will be described in detail.

  FIG. 6 is a schematic diagram for explaining the configuration of the composite magnetic sealing material constituting the magnetic mold resin 40.

  As shown in FIG. 6, the composite magnetic sealing material 2 constituting the magnetic mold resin 40 includes a resin material 4, a magnetic filler 6 and a nonmagnetic filler 8 blended in the resin material 4. Although not particularly limited, the resin material 4 is preferably composed mainly of a thermosetting resin material. Specifically, the main component is preferably an epoxy resin, a phenol resin, a urethane resin, a silicone resin, or an imide resin, and a main agent and a curing agent used for an epoxy resin or a phenol resin-based semiconductor sealing material are used. More preferred.

  Most preferred is an epoxy resin having a reactive epoxy group at the end, which can be combined with various curing agents and accelerators. Examples of the epoxy resin include bisphenol A type, bisphenol F type, phenoxy, naphthalene, polyfunctional type (dicyclopentadiene type, etc.), biphenyl type (bifunctional) and special structure type, and biphenyl that can be thermally expanded. Naphthalene, dicyclopentadiene type and the like are useful. Examples of curing agents or curing accelerators include amine compounds alicyclic diamines, aromatic diamines, other amines (imidazoles, tertiary amines), acid anhydride compounds (mainly high temperature curing agents), phenol resins (Novolak type, cresol novolak type, etc.), amino resin, dicyandiamide, Lewis acid complex compound. As a method for kneading the materials, a known method such as a kneader, a three-roll roll, or a mixer may be used as appropriate.

  The magnetic filler 6 is made of an Fe—Ni-based material, and contains 32% by weight and 39% by weight or less of a metal material mainly composed of Ni. The element that occupies the remaining 61 to 68% by weight is Fe. The blending ratio of the magnetic filler 6 is 30% by volume or more and 85% by volume or less with respect to the entire composite magnetic sealing material 2. This is because it is difficult to obtain sufficient magnetic properties when the blending ratio of the magnetic filler 6 is less than 30% by volume. When the blending ratio of the magnetic filler 6 exceeds 85% by volume, sealing such as fluidity is achieved. This is because it is difficult to secure various properties necessary for the material.

  The metal material containing Ni as a main component may contain a small amount of Co. That is, a part of Ni may be replaced by Co. According to this, the thermal expansion coefficient of the composite magnetic sealing material 2 can be further reduced. The amount of Co added is preferably 0.1 wt% or more and 8 wt% or less with respect to the entire magnetic filler 6.

  The shape of the magnetic filler 6 is not particularly limited, but it may be spherical to achieve a high filling, and a plurality of fillers having a particle size distribution may be blended and blended so as to provide the closest packing. Moreover, if the magnetic filler 6 is made into a substantially spherical shape, damage to the electronic component during molding can be reduced. In particular, it is preferable that the shape of the magnetic filler 6 is a true sphere for close packing or high packing. The magnetic filler 6 preferably has a high tap density and a small powder specific surface area. As a method for forming the magnetic filler 6, there are methods such as a water atomizing method, a gas atomizing method, and a centrifugal disk atomizing method. Among them, a gas atomizing method capable of obtaining a high tap density and reducing a specific surface area is most preferable.

  Although not particularly limited, the surface of the magnetic filler 6 is an insulating material made of an oxide of a metal such as Si, Al, Ti, Mg, or an organic material in order to improve fluidity, adhesion, and insulation. Covered with a coat 7. In order to sufficiently increase the volume resistivity of the composite magnetic sealing material 2, the thickness of the insulating coat 7 is preferably set to 10 nm or more. The insulating coat 7 may be formed by coating the surface of the magnetic filler 6 with a thermosetting material or by dehydration of tetraethyloxysilane or a metal alkoxide of tetramethyloxysilane. Formation is most preferred. Further, it is more preferable to apply an organic functional coupling treatment thereon.

The composite magnetic sealing material 2 according to the present embodiment includes a nonmagnetic filler 8. As the nonmagnetic filler 8, SiO ₂ , ZrW ₂ O ₈ , (ZrO) ₂ P ₂ O ₇ , KZr ₂ (PO ₄ ) _3, Zr ₂ (WO ₄ ) (PO ₄ ) _2, or the like is more preferable than the magnetic filler 6. It is preferable to use a material having a small thermal expansion coefficient or a material having a negative thermal expansion coefficient. If such a nonmagnetic filler 8 is added to the composite magnetic sealing material 2, the thermal expansion coefficient can be further reduced. In addition, flame retardants such as aluminum oxide and magnesium oxide, carbon black and pigments or dyes for coloring, surface treatment with a particle size of 100 nm or less to improve slipperiness, fluidity, and dispersion / kneading properties Nano silica or a wax component for improving releasability may be added. However, in the present invention, it is not essential that the composite magnetic sealing material constituting the magnetic mold resin 40 contains a nonmagnetic filler.

  In addition, an organic functional coupling treatment may be performed on the surface of the magnetic filler 6 or the nonmagnetic filler 8 in order to improve adhesion and fluidity. The organic functional coupling treatment may be performed by a known wet or dry method, or may be an integral blend method. In order to improve wettability and the like, the surfaces of the magnetic filler 6 and the nonmagnetic filler 8 may be coated with a thermosetting resin.

  When adding the nonmagnetic filler 8, it is preferable that the quantity of the nonmagnetic filler 8 with respect to the sum total of the magnetic filler 6 and the nonmagnetic filler 8 is 1 volume% or more and 40 volume% or less. In other words, 1% by volume to 40% by volume of the magnetic filler 6 can be replaced with the nonmagnetic filler 8. This is because if the addition amount of the nonmagnetic filler 8 is less than 1% by volume, the effect of adding the nonmagnetic filler 8 can hardly be obtained. If the addition amount of the nonmagnetic filler 8 exceeds 40% by volume, This is because the amount of the magnetic filler 6 becomes too small and it is difficult to ensure sufficient magnetic properties.

  The form of the composite magnetic sealing material 2 may be either liquid or solid, and the form differs depending on the selection of the main agent and the curing agent according to the molding method. The solid composite magnetic sealing material 2 may be in the form of a tablet if it is for transfer molding, and may be granular if it is for injection molding or compression molding. Further, the molding method using the composite magnetic sealing material 2 includes transfer molding, compression molding, injection molding, casting, vacuum casting, vacuum printing, printing, dispensing, and a method using a slit nozzle. it can. The molding conditions may be appropriately selected from the combination of the main agent, the curing agent, and the curing accelerator used, and after molding, after-curing may be performed as necessary.

  FIG. 7 is a graph showing the relationship between the Ni ratio of the magnetic filler 6 and the thermal expansion coefficient and magnetic permeability of the composite magnetic sealing material 2. The graph shown in FIG. 7 is a case where the magnetic filler 6 is substantially composed only of Fe and Ni, and the amount of the magnetic filler 6 added to the entire composite magnetic sealing material 2 is 70% by volume. The case where the nonmagnetic filler 8 is not added to the magnetic sealing material 2 is shown.

  As shown in FIG. 7, when the Ni ratio of the magnetic filler 6 is not less than 32% by weight and not more than 39% by weight, the thermal expansion coefficient of the composite magnetic sealing material 2 is specifically lowered, and depending on the conditions, 10 ppm / ° C. It becomes as follows. Under this condition, the lowest thermal expansion coefficient (about 9.3 ppm / ° C.) is obtained when the Ni ratio is about 35% by weight. On the other hand, regarding the magnetic permeability, the correlation with the Ni ratio is small, and μ = 12 to 13 in the range of the Ni ratio shown in FIG.

  The reason why such a characteristic is obtained is that when the Ni ratio is in the above range, an invar characteristic in which the volume change due to thermal expansion and magnetostriction cancels out appears. Such a material is called an invar material and is known as a mold material that requires high accuracy, but has not been used as a magnetic filler material to be blended in a composite magnetic sealing material. The present invention pays attention to the magnetic characteristics and low thermal expansion coefficient of the invar material, and by using this as a material for the magnetic filler, the composite magnetic sealing material 2 having a magnetic shielding property and a small thermal expansion coefficient is used. Is realized.

  FIG. 8 is a graph showing the relationship between the Ni ratio of the magnetic filler 6 and the thermal expansion coefficient of the composite magnetic sealing material 2. The graph shown in FIG. 8 is a case where the magnetic filler 6 is substantially composed only of Fe and Ni, and the addition amount of the magnetic filler 6 with respect to the entire composite magnetic sealing material 2 is 50% by volume, 60% by volume, or 70%. It shows the case where the volume% is obtained and the nonmagnetic filler 8 is not added to the composite magnetic sealing material 2.

  As shown in FIG. 8, even if the addition amount of the magnetic filler 6 is 50% by volume, 60% by volume or 70% by volume, the Ni ratio of the magnetic filler 6 is 32% by weight or more and 39% by weight or less. In this case, it can be seen that the thermal expansion coefficient of the composite magnetic sealing material 2 is specifically lowered. The value of the coefficient of thermal expansion decreases as the amount of magnetic filler 6 added increases. Therefore, when the addition amount of the magnetic filler 6 is small (for example, 30% by volume), the thermal expansion coefficient of the composite magnetic sealing material 2 is 15 ppm by further adding the nonmagnetic filler 8 made of fused silica or the like. / ° C or less. Specifically, if the total addition amount of the magnetic filler 6 and the nonmagnetic filler 8 is 50% by volume or more and 85% by volume or less, the thermal expansion coefficient of the composite magnetic sealing material 2 is sufficiently increased (for example, 15 ppm / (° C. or less).

  FIG. 9 is a graph showing the relationship between the Ni ratio of the magnetic filler 6 and the magnetic permeability of the composite magnetic sealing material 2. The graph shown in FIG. 9 is a case where the magnetic filler 6 is substantially composed only of Fe and Ni, as in the graph shown in FIG. 8, and the amount of the magnetic filler 6 added to the entire composite magnetic sealing material 2 is 50. It shows the case where the volume%, 60 volume%, or 70 volume% and the nonmagnetic filler 8 is not added to the composite magnetic sealing material 2.

  As shown in FIG. 9, it can be seen that the correlation between the Ni ratio and the magnetic permeability is small regardless of whether the magnetic filler 6 is added in an amount of 50% by volume, 60% by volume, or 70% by volume. The value of magnetic permeability increases as the amount of magnetic filler 6 added increases.

  FIG. 10 is a graph showing the relationship between the Co ratio of the magnetic filler 6 and the thermal expansion coefficient and magnetic permeability of the composite magnetic sealing material 2. In the graph shown in FIG. 10, the sum of Ni and Co contained in the magnetic filler 6 is 37% by weight, the amount of the magnetic filler 6 added to the entire composite magnetic sealing material 2 is 70% by volume, and The case where the nonmagnetic filler 8 is not added to the composite magnetic sealing material 2 is shown.

  As shown in FIG. 10, when Ni constituting the magnetic filler 6 is replaced with 8 wt% or less of Co, compared to the case where the magnetic filler 6 does not contain Co (Co = 0 wt%). It can be seen that the thermal expansion coefficient of the composite magnetic sealing material 2 is further reduced. However, if the substitution amount by Co is 10% by weight, the thermal expansion coefficient is rather high. Therefore, the amount of Co added is preferably 0.1 wt% or more and 8 wt% or less with respect to the entire magnetic filler 6.

FIG. 11 is a graph showing the relationship between the addition ratio of the nonmagnetic filler 8 and the thermal expansion coefficient of the composite magnetic sealing material 2. In the graph shown in FIG. 11, the sum of the magnetic filler 6 and the nonmagnetic filler 8 is 70% by volume, and the magnetic filler 6 is composed of 64% by weight of Fe and 36% by weight of Ni. The case made of SiO ₂ is shown.

  As shown in FIG. 11, when the proportion of the nonmagnetic filler 8 increases, the thermal expansion coefficient decreases. However, when the proportion exceeds 40 vol% of the magnetic filler, the thermal expansion coefficient is reduced. Is almost saturated. Therefore, the amount of the nonmagnetic filler 8 is preferably 1% by volume or more and 40% by volume or less with respect to the total of the magnetic filler 6 and the nonmagnetic filler 8.

FIG. 12 is a graph showing the relationship between the presence or absence of the insulating coat 7 formed on the surface of the magnetic filler 6 and the volume resistivity. There are two types of materials for the magnetic filler 6; composition A (Fe = 64 wt%, Ni = 36 wt%) and composition B (Fe = 63 wt%, Ni = 32 wt%, Co = 5 wt%), The insulating coat 7 is 40 nm thick SiO ₂ . In any case, the magnetic filler 6 has a cut diameter of 32 μm and a particle diameter D50 of 20 μm.

  As shown in FIG. 12, it can be seen that the volume resistivity of the magnetic filler 6 is greatly increased by covering the composition A and the composition B with the insulating coat 7. In addition, it can be seen that when the insulating coating 7 is used, the pressure dependency during the measurement also decreases.

  FIG. 13 is a graph showing the relationship between the film thickness of the insulating coat 7 formed on the surface of the magnetic filler 6 and the volume resistivity. The graph shown in FIG. 13 shows a case where the magnetic filler 6 is composed of 64 wt% Fe and 36 wt% Ni. The particle size of the magnetic filler 6 is the same as the particle size in FIG.

  As shown in FIG. 13, it can be seen that the volume resistivity of the magnetic filler 6 is significantly increased by covering the magnetic filler 6 with the insulating coating 7 having a thickness of 10 nm or more. In particular, it can be seen that when the magnetic filler 6 is coated with an insulating coat 7 of 30 nm or more, a very high volume resistivity can be obtained regardless of the pressure at the time of measurement.

  FIG. 14 is a graph showing the relationship between the volume resistivity of the magnetic filler 6 and the volume resistivity of the composite magnetic sealing material 2.

As shown in FIG. 14, it can be seen that the volume resistivity of the magnetic filler 6 and the volume resistivity of the composite magnetic sealing material 2 are in a proportional relationship. In particular, if the volume resistivity of the magnetic filler 6 is 10 ⁵ Ω · cm or more, the volume resistivity of the composite magnetic sealing material 2 can be 10 ¹⁰ Ω · cm or more. If the volume resistivity of the composite magnetic sealing material 2 is 10 ¹⁰ Ω · cm or more, sufficient insulation can be secured when used as a mold material for an electronic circuit package.

  As described above, the electronic circuit packages 11A and 11B according to the present embodiment have the magnetic shielding characteristics because the composite magnetic sealing material 2 having a very small thermal expansion coefficient is used as the material of the magnetic mold resin 40. However, it is possible to prevent warping of the substrate, delamination of the mold material, cracks in the mold material, and the like due to temperature changes.

<Second Embodiment>
FIG. 15 is a sectional view showing the configuration of an electronic circuit package 12A according to the second embodiment of the present invention.

  As shown in FIG. 15, in the electronic circuit package 12A according to the present embodiment, the planar size of the magnetic mold resin 40 is slightly smaller than the planar size of the substrate 20, so that the outer peripheral portion of the surface 21 of the substrate 20 is magnetic molded. The electronic circuit package 11 </ b> A according to the first embodiment shown in FIG. 1 is different in that it is exposed from the resin 40. Since other configurations are the same as those of the electronic circuit package 11A according to the first embodiment, the same elements are denoted by the same reference numerals, and redundant description is omitted.

  As exemplified by the electronic circuit package 12 </ b> A according to the present embodiment, in the present invention, it is not essential that the side surface 42 of the magnetic mold resin 40 is flush with the side surface 27 of the substrate 20. It does not matter if it is smaller.

  16 to 18 are process diagrams for explaining a method of manufacturing the electronic circuit package 12A.

  First, as shown in FIG. 16, a substrate 20 cut in advance is prepared, and a plurality of electronic components 31 and 32 are mounted so as to be connected to the land pattern 23 on the surface 21 thereof. Specifically, after supplying the solder 24 on the land pattern 23, the electronic components 31, 32 are mounted and the reflow is performed to connect the electronic components 31, 32 to the land pattern 23.

  Next, as shown in FIG. 17, the substrate 20 on which the electronic components 31 and 32 are mounted is set in a mold 80. And as shown in FIG. 18, the composite magnetic material which is the material of the magnetic mold resin 40 is inject | poured from the flow path 81 of the metal mold | die 80, and pressurization and heating are performed. Thereby, the electronic circuit package 12A according to the present embodiment is completed.

  Thus, the magnetic mold resin 40 may be formed after the substrate 20 is first separated into pieces.

<Third Embodiment>
FIG. 19 is a sectional view showing the configuration of an electronic circuit package 13A according to the third embodiment of the present invention.

  As shown in FIG. 19, the electronic circuit package 13 </ b> A according to the present embodiment further includes a metal film 60 that covers the upper surface 41 and the side surface 42 of the magnetic mold resin 40 and the side surface 27 of the substrate 20. This is different from the electronic circuit package 11A according to the first embodiment shown in FIG. In addition, among the internal wirings 25, the internal wiring 25 with G at the end of the reference numeral is a power supply pattern, and a part thereof is exposed on the side surface 27 of the substrate 20. The power supply pattern 25G is typically a ground pattern to which a ground potential is applied, but is not limited to a ground pattern as long as it is a pattern to which a fixed potential is applied. Since other configurations are the same as those of the electronic circuit package 11A according to the first embodiment, the same elements are denoted by the same reference numerals, and redundant description is omitted.

  The metal film 60 is an electromagnetic shield and preferably contains at least one metal selected from the group consisting of Au, Ag, Cu, and Al as a main component. The metal film 60 is preferably as low in resistance as possible, and Cu is most preferably used in view of cost and the like. Further, the outer surface of the metal film 60 is covered with an anti-oxidation coating made of an anticorrosive metal such as SUS, Ni, Cr, Ti, brass, or a resin such as epoxy, phenol, imide, urethane, or silicone. It is preferable. This is because the metal film 60 is oxidized and deteriorated in an external environment such as heat and humidity, and thus the above-described treatment is preferably performed in order to suppress and prevent this. The method for forming the metal film 60 may be selected as appropriate from known methods such as sputtering, vapor deposition, electroless plating, and electrolytic plating, and plasma treatment that is a pretreatment for improving adhesion before the metal film 60 is formed. Further, a coupling process, a blast process, an etching process, or the like may be performed. Further, as the base of the metal film 60, a highly adhesive metal film such as titanium, chromium, or SUS may be thinly formed in advance.

  As shown in FIG. 19, the power supply pattern 25 </ b> G is exposed on the side surface 27 of the substrate 20, and the metal film 60 is connected to the power supply pattern 25 </ b> G by covering the side surface 27 of the substrate 20.

The resistance value at the interface between the metal film 60 and the magnetic mold resin 40 is preferably 10 ⁶ Ω or more. According to this, since the eddy current generated by electromagnetic wave noise entering the metal film 60 hardly flows into the magnetic mold resin 40, it is possible to prevent the magnetic characteristics of the magnetic mold resin 40 from being deteriorated due to the inflow of eddy current. It becomes possible. The resistance value at the interface between the metal film 60 and the magnetic mold resin 40 refers to the surface resistance of the magnetic mold resin 40 when both are in direct contact, and when there is an insulation film between the two, Refers to surface resistance. The resistance value at the interface between the metal film 60 and the magnetic mold resin 40 is preferably 10 ⁶ Ω or more over the entire surface, but even if there is a region where the resistance value is less than 10 ⁶ Ω partially. I do not care.

The surface resistance value of the magnetic mold resin 40 basically matches the volume resistivity of the magnetic mold resin 40. Therefore, if the volume resistivity of the magnetic mold resin 40 is 10 ¹⁰ Ω · cm or more, basically, the surface resistance value of the magnetic mold resin 40 is also 10 ¹⁰ Ω or more. However, as described with reference to FIG. 5, since the magnetic mold resin 40 is diced at the time of manufacture, the magnetic filler 6 may be exposed on the cut surface (that is, the side surface 42). There is a possibility that the surface resistance value of the side surface 42 is lowered as compared with the above. Similarly, even when the upper surface 41 of the magnetic mold resin 40 is ground for the purpose of reducing the height and surface roughness, the magnetic filler 6 made of a soft magnetic metal may be exposed on the upper surface 41. There is a possibility that the surface resistance value of the upper surface 41 is lower than the resistivity. As a result, even if the volume resistivity of the magnetic mold resin 40 is 10 ¹⁰ Ω · cm or more, the surface resistance value of the magnetic mold resin 40 may be less than 10 ¹⁰ Ω. In such a case, However, if the surface resistance of the magnetic mold resin 40 is 10 ⁶ Ω or more, the inflow of eddy current can be prevented.

Further, when the surface resistance value of the upper surface 41 or the side surface 42 of the magnetic mold resin 40 is reduced to less than 10 ⁶ Ω, a thin insulating material may be formed on the upper surface 41 or the side surface 42 of the magnetic mold resin 40. FIG. 20 is a cross-sectional view showing the configuration of the electronic circuit package 13B according to the first modification, in which a thin insulating film 70 is interposed between the upper surface 41 and the side surface 42 of the magnetic mold resin 40 and the metal film 60. However, it differs from the electronic circuit package 13A shown in FIG. If such an insulating film 70 is interposed, even if the surface resistance value of the upper surface 41 or the side surface 42 of the magnetic mold resin 40 is reduced to less than 10 ⁶ Ω, the metal film 60 and the magnetic mold resin 40 are used. The resistance value at the interface can be made 10 ⁶ Ω or more, and it is possible to prevent the magnetic characteristics from being deteriorated due to the eddy current.

  FIG. 21 is a cross-sectional view showing a configuration of an electronic circuit package 13C according to a second modification of the present embodiment.

  As shown in FIG. 21, in the electronic circuit package 13 </ b> C according to the second modification example of the present embodiment, the planar size of the magnetic mold resin 40 is slightly smaller than the planar size of the substrate 20. This is different from the electronic circuit package 13 </ b> A shown in FIG. 19 in that the outer periphery of the electronic package is exposed from the magnetic mold resin 40. Since the other configuration is the same as that of the electronic circuit package 13A shown in FIG. 19, the same elements are denoted by the same reference numerals, and redundant description is omitted.

  As exemplified by the electronic circuit package 13 </ b> C according to this modification, in the present invention, it is not essential that the side surface 42 of the magnetic mold resin 40 forms the same plane as the side surface 27 of the substrate 20. It does not matter if it is smaller.

  Further, as shown in an electronic circuit package 13D shown in FIG. 22 as a third modification, the metal film 60 may have a structure that does not cover the side surface 27 of the substrate 20. In this case, the power supply pattern 28 </ b> G is provided on the outer peripheral portion exposed from the magnetic mold resin 40 on the surface 21 of the substrate 20, and the power supply pattern 28 </ b> G is in contact with the metal film 60. Thereby, a fixed potential such as a ground potential is applied to the metal film 60.

  FIG. 23 is a cross-sectional view showing a configuration of an electronic circuit package 13E according to a fourth modification of the present embodiment.

  As shown in FIG. 23, the electronic circuit package 13E according to the fourth modification of the present embodiment has the electronic circuit package 13E shown in FIG. 19 in that the planar size of the magnetic mold resin 40 is slightly larger than the planar size of the substrate 20. This is different from the circuit package 13A. Since the other configuration is the same as that of the electronic circuit package 13A shown in FIG. 19, the same elements are denoted by the same reference numerals, and redundant description is omitted.

  As illustrated in the electronic circuit package 13E according to this modification, in the present invention, the magnetic mold resin 40 may have a larger planar size than the substrate 20.

  Thus, since the electronic circuit packages 13A to 13E according to the present embodiment use the magnetic mold resin 40 and the surface thereof is covered with the metal film 60, a composite shield structure can be obtained. Thereby, electromagnetic wave noise radiated | emitted from the electronic components 31 and 32 and electromagnetic wave noise which injects into the electronic components 31 and 32 from the outside can be effectively shielded, implement | achieving low profile. In particular, the electronic circuit packages 13 </ b> A to 13 </ b> E according to the present embodiment can more effectively shield electromagnetic wave noise radiated from the electronic components 31 and 32. This is because part of the electromagnetic noise generated from the electronic components 31 and 32 is absorbed when passing through the magnetic mold resin 40, and part of the electromagnetic noise that is not absorbed is reflected by the metal film 60. It is because it passes 40 again. Thus, since the magnetic mold resin 40 acts twice on the incident electromagnetic noise, the electromagnetic noise radiated from the electronic components 31 and 32 can be effectively shielded.

Moreover, in the electronic circuit packages 13A to 13E according to the present embodiment, if the volume resistivity of the magnetic mold resin 40 is 10 ¹⁰ Ω · cm or more, sufficient insulation required for the mold member can be ensured. In addition, if the resistance value at the interface between the magnetic mold resin 40 and the metal film 60 is set to 10 ⁶ Ω or more, eddy current generated by electromagnetic wave noise entering the metal film 60 hardly flows into the magnetic mold resin 40. For this reason, it becomes possible to prevent the magnetic characteristic of the magnetic mold resin 40 from being lowered due to the inflow of eddy current.

  FIG. 24 is a graph showing the amount of noise attenuation of the electronic circuit package 13A, and shows a case where the thickness of the substrate 20 is 0.25 mm and the thickness of the magnetic mold resin 40 is 0.50 mm. The metal film 60 is a laminated film of Cu and Ni, and two types of metal films 60 having different Cu film thicknesses are evaluated. Specifically, the metal film 60 of sample A has a configuration in which 4 μm Cu and 2 μm Ni are laminated, and the metal film 60 in sample B has a configuration in which 7 μm Cu and 2 μm Ni are laminated. ing. For comparison, values of samples C and D using a molding material not including the magnetic filler 6 are also shown. The metal film 60 of sample C has a configuration in which 4 μm of Cu and 2 μm of Ni are stacked, and the metal film 60 of sample D has a configuration in which 7 μm of Cu and 2 μm of Ni are stacked.

  As shown in FIG. 24, when the composite magnetic sealing material 2 including the magnetic filler 6 is used, noise attenuation particularly in a frequency band of 100 MHz or less is increased as compared with the case where the mold material not including the magnetic filler 6 is used. I understand. In addition, as for the metal film 60, higher noise attenuation characteristics can be obtained when the thickness is larger.

  25 to 27 are graphs showing the relationship between the thickness of the metal film 60 included in the electronic circuit package 13A and the amount of noise attenuation. 25 shows noise attenuation at 20 MHz, FIG. 26 shows 50 MHz, and FIG. 27 shows 100 MHz. For comparison, values when using a molding material that does not include the magnetic filler 6 are also shown.

  As shown in FIGS. 25 to 27, it can be seen that, in any frequency band, the higher the thickness of the metal film 60, the higher the noise attenuation characteristics. Further, it can be seen that, in any frequency band, higher noise attenuation characteristics can be obtained by using the composite magnetic sealing material 2 including the magnetic filler 6 than in the case of using the mold material not including the magnetic filler 6. .

FIG. 28 is a graph showing the warping amount of the substrate 20 when the electronic circuit package 11A (without metal film) and the electronic circuit package 13A (with metal film) are heated and lowered. For comparison, FIG. 29 shows values when the magnetic filler 6 is replaced with a nonmagnetic filler made of SiO ₂ .

As shown in FIG. 28, it can be seen that the electronic circuit package 13 </ b> A having the metal film 60 has a smaller warp of the substrate 20 due to temperature change than the electronic circuit package 11 </ b> A having no metal film 60. 28 and 29, the warping characteristics of the electronic circuit packages 11A and 13A using the composite magnetic sealing material 2 including the magnetic filler 6 are the molds including the non-magnetic filler made of SiO _2. This is almost the same as when using materials.

<Fourth Embodiment>
FIG. 30 is a cross-sectional view showing a configuration of an electronic circuit package 14A according to the fourth embodiment of the present invention.

  As shown in FIG. 30, the electronic circuit package 14A according to the present embodiment is the same as the electronic circuit package 13A according to the third embodiment shown in FIG. 19 except that the shapes of the substrate 20 and the metal film 60 are different. is there. For this reason, the same code | symbol is attached | subjected to the same element and the overlapping description is abbreviate | omitted.

  In the present embodiment, the side surface 27 of the substrate 20 is stepped. Specifically, the side surface lower part 27b has a shape protruding from the side surface upper part 27a. The metal film 60 is not formed on the entire side surface of the substrate 20, but is provided so as to cover the side surface upper portion 27 a and the stepped portion 27 c, and the side surface lower portion 27 b is not covered with the metal film 60. Also in this embodiment, since the power supply pattern 25G is exposed at the side surface upper portion 27a of the substrate 20, the metal film 60 is connected to the power supply pattern 25G through this portion.

  31 and 32 are process diagrams for explaining a method of manufacturing the electronic circuit package 14A.

  First, after the magnetic mold resin 40 is formed on the surface 21 of the collective substrate 20A by the method described with reference to FIGS. 3 and 4, as shown in FIG. 31, the grooves 43 are formed along the broken line a indicating the dicing position. Form. In the present embodiment, since the power supply pattern 25G crosses the broken line a which is the dicing position, the power supply pattern 25G is exposed from the side surface 27 of the substrate 20 when the collective substrate 20A is cut along the broken line a. The groove 43 has a depth that completely cuts the magnetic mold resin 40 and does not completely cut the aggregate substrate 20A. As a result, the side surface 42 of the magnetic mold resin 40, the side surface upper portion 27 a and the stepped portion 27 c of the substrate 20 are exposed inside the groove 43. Here, as the depth of the side surface upper portion 27a, it is necessary to set at least a depth at which the power supply pattern 25G is exposed.

  Next, as shown in FIG. 32, a metal film 60 is formed by sputtering, vapor deposition, electroless plating, electrolytic plating, or the like. Thereby, the upper surface 41 of the magnetic mold resin 40 and the inside of the groove 43 are covered with the metal film 60. At this time, the power supply pattern 25 </ b> G exposed on the upper side surface 27 a of the substrate 20 is connected to the metal film 60.

  And if the board | substrate 20 is separated into pieces by cut | disconnecting the aggregate substrate 20A along the broken line a, the electronic circuit package 14A by this embodiment will be completed.

  As described above, according to the method for manufacturing the electronic circuit package 14A according to the present embodiment, since the groove 43 is formed, the metal film 60 can be formed before the collective substrate 20A is separated into pieces. Formation of the film 60 is easy and reliable.

  The preferred embodiments of the present invention have been described above, but the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention. Needless to say, it is included in the range.

<Creation of composite magnetic sealing material>
830S (bisphenol A type epoxy resin) manufactured by DIC as a main agent, 0.5 equivalent of DicyDD (didiandiamide) manufactured by Nippon Carbide Industries Co., Ltd. as a curing agent, and 1 wt% of Shikoku Chemical Industry as a curing accelerator. Resin materials were prepared using C11Z-CN (imidazole) manufactured by the company.

  A magnetic filler having the composition shown in FIG. 33 was added to the above resin material by 50 volume%, 60 volume% or 70 volume%, and kneaded well to obtain a paste. In addition, when the paste could not be formed, butyl carbitol acetate was added in a timely manner. This paste was applied to a thickness of about 300 μm and thermally cured in order of 100 ° C. for 1 hour, 130 ° C. for 1 hour, 150 ° C. for 1 hour, and 180 ° C. for 1 hour to obtain a cured sheet. Composition 1 (comparative example) is a magnetic material generally called PB permalloy.

<Measurement of thermal expansion coefficient>
The above cured sheet is cut into a length of 12 mm and a width of 5 mm, and the temperature is increased from room temperature to 200 ° C. at 5 ° C./minute using TMA, and expansion in a temperature range of 50 ° C. to 100 ° C. lower than the glass transition temperature. The coefficient of thermal expansion was calculated from the amount. The measurement results are shown in FIG. FIG. 34 also shows the results when a nonmagnetic filler made of SiO ₂ is used instead of the magnetic filler.

As shown in FIG. 34, when the magnetic fillers of composition 2 and composition 3 were used, the thermal expansion coefficient was significantly smaller than when the magnetic filler of composition 1 (comparative example) was used. In particular, when the addition amount is 60% by volume or more, a thermal expansion coefficient equivalent to that when a nonmagnetic filler made of SiO ₂ is used is obtained, and when the addition amount is 70% by volume, thermal expansion is achieved. The coefficient was 10 ppm / ° C. or less.

<Measurement of magnetic permeability>
The cured sheet was cut into a ring shape having an outer diameter of 7.9 mm and an inner diameter of 3.1 mm, and an effective magnetic permeability (μ ′) of 10 MHz was measured using a material analyzer function of impedance analyzer E4991 manufactured by Agilent. The measurement results are shown in FIG.

  As shown in FIG. 35, the magnetic permeability obtained when the magnetic fillers of composition 2 and composition 3 were used was substantially the same as the magnetic permeability obtained when the magnetic filler of composition 1 (comparative example) was used. .

<Discussion>
The composite magnetic sealing material obtained by adding the magnetic fillers of the composition 2 and the composition 3 to the resin material has a thermal expansion coefficient equivalent to that when the nonmagnetic filler made of SiO ₂ is used, and the magnetic material made of PB permalloy. Magnetic permeability equivalent to that obtained when the filler was used could be obtained. For this reason, if a composite magnetic sealing material obtained by adding a magnetic filler of composition 2 or composition 3 to a resin material is used as a sealing material for an electronic circuit package, warping of the substrate, delamination of the molding material, It is possible to obtain high magnetic shield characteristics while preventing cracks and the like.

2 Composite magnetic sealing material 4 Resin material 6 Magnetic filler 7 Insulation coating 8 Nonmagnetic filler 11A, 11B, 12A, 13A-13E, 14A Electronic circuit package 20 Substrate 20A Aggregate substrate 21 Substrate surface 22 Substrate surface 23 Land pattern 24 Solder 25 Internal wiring 25G Power supply pattern 26 External terminal 27 Substrate side surface 27a Substrate side surface upper portion 27b Substrate side surface lower portion 27c Substrate step portion 28G Power supply patterns 31, 32 Electronic component 40 Magnetic mold resin 41 Upper surface 42 of magnetic mold resin Magnetic mold Resin side surface 43 Groove 50 Nonmagnetic member 60 Metal film 70 Insulating film 80 Mold 81 Flow path

Claims (20)

A substrate,
Electronic components mounted on the surface of the substrate;
A magnetic mold resin covering the surface of the substrate so as to embed the electronic component,
The magnetic mold resin is
Resin material,
Blended with the resin material, and a blending ratio of 30 to 85% by volume,
The electronic circuit package, wherein the filler includes a magnetic filler containing Fe to 32% by weight of a metal material containing Ni as a main component, whereby the thermal expansion coefficient of the magnetic mold resin is 15 ppm / ° C. or less.   The electronic circuit package according to claim 1, wherein the metal material further includes 0.1 to 8% by weight of Co with respect to the entire magnetic filler.   The electronic circuit package according to claim 1, wherein the filler further includes a nonmagnetic filler.   The electronic circuit package according to claim 3, wherein an amount of the nonmagnetic filler with respect to a total of the magnetic filler and the nonmagnetic filler is 1 to 40% by volume. The nonmagnetic filler is at least selected from the group consisting of SiO ₂ , ZrW ₂ O ₈ , (ZrO) ₂ P ₂ O ₇ , KZr ₂ (PO ₄ ) ₃ and Zr ₂ (WO ₄ ) (PO ₄ ) _2. The electronic circuit package of claim 4, comprising one material.   The electronic circuit package according to claim 1, wherein the magnetic filler has a substantially spherical shape.   The electronic circuit package according to claim 1, wherein a surface of the magnetic filler is coated with an insulating coating.   The electronic circuit package according to claim 7, wherein the insulating coat has a thickness of 10 nm or more.   The electronic circuit package according to claim 1, wherein the resin material is a thermosetting resin material.   The electronic circuit package according to claim 9, wherein the thermosetting resin material includes at least one material selected from the group consisting of an epoxy resin, a phenol resin, a urethane resin, a silicone resin, and an imide resin. The electronic circuit package according to claim 1, wherein the volume resistivity of the magnetic mold resin is 10 ¹⁰ Ω · cm or more.   The electronic circuit package according to claim 1, further comprising a nonmagnetic member provided between the electronic component and the magnetic mold resin.   The electronic circuit package according to claim 1, further comprising a metal film that is connected to a power supply pattern provided on the substrate and covers the magnetic mold resin.   The electronic circuit package according to claim 13, wherein the metal film contains at least one metal selected from the group consisting of Au, Ag, Cu, and Al as a main component.   The electronic circuit package according to claim 13, wherein a surface of the metal film is covered with an antioxidant coating.   The electronic circuit package according to claim 13, wherein the power supply pattern is exposed on a side surface of the substrate, and the metal film is in contact with the power supply pattern exposed on the side surface of the substrate. A substrate,
Electronic components mounted on the surface of the substrate;
A magnetic mold resin covering the surface of the substrate so as to embed the electronic component,
The magnetic mold resin is
Resin material,
A magnetic filler made of Fe-Ni material blended in the resin material;
A non-magnetic filler blended in the resin material,
The amount of the nonmagnetic filler relative to the total of the magnetic filler and the nonmagnetic filler is 1 to 40% by volume,
An electronic circuit package, wherein the magnetic mold resin has a thermal expansion coefficient of 15 ppm / ° C. or less.   18. The electronic circuit package according to claim 17, wherein the magnetic filler is made of a material containing Fe to 32-39% by weight of a metal material mainly composed of Ni. A substrate,
Electronic components mounted on the surface of the substrate;
A magnetic mold resin covering the surface of the substrate so as to embed the electronic component,
The magnetic mold resin is
Resin material,
A magnetic filler which is blended in the resin material and contains 32 to 39% by weight of a metal material mainly containing Ni in Fe;
A non-magnetic filler blended in the resin material,
The blending amount of the magnetic filler is 30 to 85% by volume of the whole,
The electronic circuit package, wherein the total blending amount of the magnetic filler and the nonmagnetic filler is 50 to 85% by volume of the whole.   The electronic circuit package according to claim 19, wherein the metal material further includes 0.1 to 8 wt% Co with respect to the entire magnetic filler.