TWI732947B - Electronic circuit package using composite magnetic sealing material - Google Patents

Abstract

Disclosed herein is an electronic circuit package includes a substrate, an electronic component mounted on a surface of the substrate, and a magnetic mold resin covering the surface of the substrate so as to embed therein the electronic component. The magnetic mold resin includes a resin material and a filler blended in the resin material in a blended ratio of 30 vol.% or more to 85 vol.% or less. The filler includes a magnetic filler containing Fe and 32 wt.% or more and 39 wt.% or less of a metal material contained mainly of Ni, thereby a thermal expansion coefficient of the magnetic mold resin is 15 ppm/℃ or less.

Description

Electronic circuit packaging using composite magnetic sealing materials

The present invention relates to electronic circuit packaging, in particular to electronic circuit packaging using composite magnetic materials as plastic film materials.

In recent years, electronic devices such as smartphones have adopted high-performance wireless communication circuits and digital chips, and the operating frequency of semiconductor ICs used has also tended to increase. In addition, system-in-package (SIP) with a 2.5D structure or a 3D structure that connects plural semiconductor ICs with the shortest wiring is accelerating, and it is predicted that the modularization of power supply circuits will increase in the future. In addition, it is predicted that most electronic parts (passive parts such as inductors, capacitors, resistors, filters, etc.; active parts such as transistors and diodes; integrated circuit parts such as semiconductor ICs; and other parts necessary for the construction of electronic circuits are collectively called ) Modularized electronic circuit modules will also increase in the future. These collectively referred to as electronic circuit packages will tend to be mounted in high density due to the high performance, miniaturization, and thinning of electronic devices such as smartphones. These tendencies show that unilateral misoperations and electromagnetic interference caused by noise tend to be more obvious. The conventional noise countermeasures are more difficult to prevent misoperations or electromagnetic interference. Therefore, in recent years, there has been an evolution towards self-shielding of electronic circuit packaging, and there have been proposals to use conductive paste, plating, or sputtering to perform electromagnetic shielding. However, practical application will require higher shielding characteristics in the future.

In order to achieve this requirement, there have been proposals in recent years for electronic circuit packaging in which the molding material itself has magnetic shielding characteristics. For example, the molding material for electronic circuit packaging disclosed in Patent Document 1 is a composite magnetic sealing material to which soft magnetic powder with an oxide film is added.

However, the conventional composite magnetic sealing material has the problem of large thermal expansion coefficient. Therefore, a thermal expansion coefficient mismatch will occur between the composite magnetic sealing material and the packaging substrate or electronic parts. As a result, the substrate will be assembled in a strip shape after molding and large warpage or individual pieces will occur. When the electronic circuit package is installed and reflowed, a large degree of warpage is caused by the connectivity problem. The following describes this phenomenon.

In recent years, various structures have been proposed for semiconductor packages or electronic component modules and have been put into practical use. At present, the mainstream generally adopts mounting electronic components such as semiconductor ICs on organic multilayer substrates, and then molding the upper and surrounding areas with resin sealing materials.的结构。 The structure. The semiconductor package or electronic component module with such a structure is manufactured by performing plastic molding according to the state of the assembled substrate, and then performing individual chip processing using crystal cutting or the like.

Since this structure is a so-called "bimetal" composed of organic multilayer substrates with different physical properties and resin sealing materials, it will warp due to factors such as poor thermal expansion coefficient, glass transfer, and curing and shrinkage of the mold material. To suppress this phenomenon, it is necessary to match the physical properties such as thermal expansion coefficient as much as possible. In recent years, organic multilayer substrates used in semiconductor packages or electronic circuit modules have a tendency to be thinner and multilayered due to their low profile requirements. In order to achieve high operability for thin substrates while meeting this requirement For rigidity and low thermal expansion, generally use substrate materials with a higher glass transition temperature, add fillers with a low thermal expansion coefficient to the substrate materials, and use glass fiber cloth with a lower thermal expansion coefficient.

On the other hand, due to the poor physical properties between the semiconductor IC and electronic components mounted on the substrate and the molding material, stress will also be generated, which will cause various problems such as peeling of the interface of the molding material, cracking of the electronic components or the molding material. Semiconductor IC uses silicon. The thermal expansion coefficient of silicon is 3.5 ppm/℃, while the thermal expansion coefficient of calcined chip parts such as ceramic capacitors and inductors is about 10 ppm/℃.

Therefore, molding materials also require low thermal expansion, and materials as low as 10 ppm/°C are commercially available. The method of low thermal expansion of the molding material is, of course, a low thermal expansion epoxy resin, 0.5ppm/℃ and a very low thermal expansion coefficient of fused silica, and a high filling rate is mixed into the sealing resin.

[Prior Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 10-64714

On the other hand, the thermal expansion coefficient of general magnetic materials is relatively high. Therefore, as described in Patent Document 1, a composite magnetic sealing material in which a general soft magnetic body powder is added to a mold resin may not achieve the target low thermal expansion coefficient.

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

The electronic circuit package of the present invention is provided with a substrate, electronic components mounted on the surface of the substrate, and a magnetic molding resin that covers the surface of the substrate and embeds the electronic components; wherein the magnetic molding resin includes There are: resin materials, and fillers blended in the above resin materials with a blending ratio of 30 to 85% by volume; the above fillers include magnetic fillers containing 32 to 39 wt% of metallic materials with Ni as the main component in Fe. The thermal expansion coefficient of the above-mentioned magnetic molding resin is 15 ppm/°C or less.

According to the present invention, since a magnetic filler with a low thermal expansion coefficient is used, the thermal expansion coefficient of the magnetic molding resin composed of the composite magnetic sealing material can be set to 15 ppm/°C or less. Therefore, it is possible to prevent the warpage of the substrate, the peeling of the mold material interface, and the cracking of the mold material.

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. In this way, the thermal expansion coefficient of the magnetic molding resin composed of the composite magnetic sealing material can be further reduced.

In the present invention, the above-mentioned filler may further contain a non-magnetic filler. In this way, the thermal expansion coefficient of the magnetic molding resin composed of the composite magnetic sealing material can be further reduced. In this case, the amount of the non-magnetic filler is preferably 1 to 40% by volume relative to the total of the magnetic filler and the non-magnetic filler. In this way, the thermal expansion coefficient of the magnetic molding resin composed of the composite magnetic sealing material can be further reduced while ensuring sufficient magnetic properties. In this case, the above-mentioned non-magnetic filler is preferably composed 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 Select at least one material in the group. Because the thermal expansion coefficient of these materials is very low or has a negative value, the thermal expansion coefficient of the magnetic molding resin composed of the composite magnetic sealing material can be further reduced.

In the present invention, the shape of the above-mentioned magnetic filler is preferably approximately spherical. In this way, the proportion of magnetic fillers in the composite magnetic sealing material can be increased.

In the present invention, the surface of the magnetic filler is preferably provided with an insulating coating, and more preferably, the thickness of the insulating coating is 10 nm or more. In this way, the volume resistivity of the magnetic molding resin composed of the composite magnetic sealing material can be increased to, for example, 10 ¹⁰ Ω·cm or more, and the insulating properties required by the molding material for electronic circuit packaging can be ensured.

In the present invention, the above-mentioned resin material is preferably a thermosetting resin material, and the above-mentioned thermosetting resin material is preferably composed of epoxy resin, phenol resin, urethane resin, silicone resin, and imide resin Select at least one material in the group.

The electronic circuit package of the present invention may further include a non-magnetic member provided between the electronic component and the magnetic mold resin. In this way, it is possible to suppress changes in the characteristics of the electronic parts caused by the proximity of the electronic parts and the magnetic mold resin.

The electronic circuit package of the present invention preferably further includes a metal film connected to the power supply pattern provided on the substrate and covering the magnetic mold resin. In this way, a composite shielding structure that can combine electromagnetic shielding functions and magnetic shielding functions can be obtained.

In this case, the metal film is preferably made of at least one metal selected from the group consisting of Au, Ag, Cu, and Al as the main component, and the surface of the metal film is preferably covered with an anti-oxidation coating. Furthermore, it is preferable that the power supply pattern is exposed on the side surface of the substrate, and the metal film is adjacent to 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.

Accordingly, because the electronic circuit package of the present invention uses a magnetic molding resin with a small thermal expansion coefficient as a molding material, it can prevent substrate warpage, peeling of the molding material interface, and mold while ensuring the characteristics of the magnetic screen. Wood cracks and other situations.

2‧‧‧Composite magnetic sealing material

4‧‧‧Resin material

6‧‧‧Magnetic filler

7‧‧‧Insulation coating

8‧‧‧Non-magnetic filler

11A, 11B, 12A, 13A~13E, 14A‧‧‧Electronic circuit packaging

20‧‧‧Substrate

20A‧‧‧Assembly substrate

21‧‧‧Substrate surface

22‧‧‧The back of the substrate

23‧‧‧Land Pattern

24‧‧‧Solder

25‧‧‧Internal wiring

25G‧‧‧Power pattern

26‧‧‧External terminal

27‧‧‧The side of the substrate

27a‧‧‧The upper side of the base plate

27b‧‧‧The lower part of the side of the base plate

27c‧‧‧The step part of the substrate

28G‧‧‧Power pattern

31、32‧‧‧Electronic parts

40‧‧‧Magnetic plastic molding resin

41‧‧‧On top of magnetic plastic molding resin

42‧‧‧The side of the magnetic plastic molding resin

43‧‧‧ditch

50‧‧‧Non-magnetic components

60‧‧‧Metal Film

70‧‧‧Insulation film

80‧‧‧Mould

81‧‧‧Flow Path

Fig. 1 is a cross-sectional view showing the structure of an electronic circuit package according to a first embodiment of the present invention.

Fig. 2 is a cross-sectional view showing the configuration of an electronic circuit package according to a modification of the first embodiment.

FIG. 3 is a step diagram for explaining the manufacturing method of the electronic circuit package shown in FIG. 1. FIG.

FIG. 4 is a step diagram for explaining the manufacturing method of the electronic circuit package shown in FIG. 1. FIG.

FIG. 5 is a step diagram for explaining the manufacturing method of the electronic circuit package shown in FIG. 1. FIG.

Fig. 6 is a schematic diagram for explaining the composition 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 magnetic 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 and the thermal expansion coefficient and magnetic permeability of the composite magnetic sealing material.

Fig. 11 is a graph showing the relationship between the addition ratio of the non-magnetic filler and the thermal expansion coefficient of the composite magnetic sealing material.

Figure 12 is a graph showing the relationship between the presence or absence of an insulating coating 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 coating 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 structure of an electronic circuit package according to a second embodiment of the present invention.

FIG. 16 is a step diagram for explaining the manufacturing method of the electronic circuit package shown in FIG. 15.

FIG. 17 is a step diagram for explaining the manufacturing method of the electronic circuit package shown in FIG. 15.

Figure 18 is used to illustrate the steps of the method of manufacturing the electronic circuit package shown in Figure 15 picture.

Fig. 19 is a cross-sectional view showing the structure of an electronic circuit package according to a third embodiment of the present invention.

20 is a cross-sectional view showing the structure of an electronic circuit package according to a first modification of the third embodiment.

Fig. 21 is a cross-sectional view showing the configuration of an electronic circuit package according to a second modification of the third embodiment.

Fig. 22 is a cross-sectional view showing the configuration of an electronic circuit package according to a third modification of the third embodiment.

Fig. 23 is a cross-sectional view showing the configuration of an electronic circuit package according to a fourth modification of the third embodiment.

Fig. 24 is a graph showing the amount of noise attenuation of the electronic circuit package shown in Fig. 19;

FIG. 25 is a graph showing the relationship between the film thickness of the metal film contained 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 film thickness of the metal film contained 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 film thickness of the metal film contained in the electronic circuit package shown in FIG. 19 and the amount of noise attenuation.

Fig. 28 is a graph showing the amount of substrate warpage of the electronic circuit package shown in Figs. 1 and 19 when the temperature is raised and lowered.

FIG. 29 is a graph showing the amount of substrate warpage in the electronic circuit package of the comparative example when the temperature is raised and lowered.

Fig. 30 is a cross-sectional view showing the structure of an electronic circuit package according to a fourth embodiment of the present invention.

FIG. 31 is a step diagram for explaining the manufacturing method of the electronic circuit package shown in FIG. 30.

FIG. 32 is a step diagram for explaining the manufacturing method of the electronic circuit package shown in FIG. 30. 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 the measurement results of the examples.

Hereinafter, the 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 the structure of an electronic circuit package 11A according to the first embodiment of the present invention.

As shown in FIG. 1, the electronic circuit package 11A of this embodiment is provided with a substrate 20, a plurality of electronic components 31, 32 mounted on the substrate 20, and the electronic components 31, 32 are embedded to cover the surface of the substrate 20 21 of the magnetic molding resin 40.

There is no particular limitation on the type of the electronic circuit package 11A of this embodiment. Examples include: a high-frequency module that handles high-frequency signals, a power module that implements power control, and a system-in-package (SIP) with a 2.5D structure or a 3D structure. , Semiconductor packages for wireless communications or digital circuits, etc. In FIG. 1, only two electronic components 31 and 32 are shown, but there are actually more electronic components built-in.

The substrate 20 has a double-sided and multilayer wiring structure with a large number of wiring embedded therein, and can be an organic substrate with a thermosetting resin base material such as FR-4, FR-5, BT, cyanate ester, phenol, and amide; liquid crystal; Organic substrates such as polymers and other thermoplastic resin substrates; LTCC substrates, HTCC substrates, flexible substrates, etc., regardless of type. The substrate 20 of this embodiment 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 a two-layer wiring layer embedded in the 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 with the electronic components 31 and 32, and the two are electrically and mechanically connected via the 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 wafer, etc.) may be embedded in the substrate 20.

The land pattern 23 is connected to the external terminal 26 formed on the back surface 22 of the substrate 20 via the internal wiring 25 formed inside the substrate 20. In actual use, the electronic circuit package 11A is mounted on a mother board or the like not shown, and then the land pattern on the mother board is electrically connected to the external terminal 26 of the electronic circuit package 11A. The conductor material constituting the land pattern 23, the internal wiring 25 and the external terminal 26 can be copper, silver, gold, nickel, chromium, aluminum, palladium, indium and other metals, or metal alloys thereof, or a combination of resin or glass As the conductive material of the adhesive, when the substrate 20 is an organic substrate or a flexible substrate, it is preferable to use copper or silver from the viewpoint of cost, conductivity, and the like. The formation methods of these conductive materials can be used: printing, electroplating, foil lamination, sputtering, vapor deposition, inkjet and other methods.

The magnetic mold resin 40 is provided by covering the surface 21 of the substrate 20 with the electronic components 31 and 32 in an embedded manner. The magnetic molding resin 40 is a molding member and also has a function of magnetic shielding. In this embodiment, the side surface 42 of the magnetic mold resin 40 and the side surface 27 of the substrate 20 form the same plane. The details of the magnetic molding resin 40 will be described later. Compared with the conventional magnetic molding resin, it is composed of a composite magnetic sealing material with a very small thermal expansion coefficient (for example, 15 ppm/°C or less). Since the magnetic mold resin 40 is adjacent to the electronic components 31, 32 or the land pattern 23, its volume resistivity must be sufficiently high, and specifically, it is preferably 10 ¹⁰ Ω·cm or more.

Furthermore, if the distance between electronic components such as a high-frequency inductor and the magnetic mold resin 40 is too close, the characteristics such as the inductance value may vary from the design value. In this case, by covering part or all of the electronic components with non-magnetic members, the variation in characteristics can be reduced. The cross-sectional view of the configuration of the electronic circuit package 11B of the modified example shown in FIG. 2 is different from the electronic circuit package 11A shown in FIG. 1 in that the electronic component 32 is covered with the non-magnetic member 50. For the non-magnetic member 50, general resins can be used. If such a non-magnetic member 50 is interposed between the electronic component 32 and the magnetic molding resin 40, since the distance between the electronic component 32 and the magnetic molding resin 40 is separated, the variation in characteristics such as inductance value can be reduced.

Next, the method of manufacturing the electronic circuit package 11A of this embodiment will be described.

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

First, as shown in FIG. 3, a collective substrate 20A having a multilayer wiring structure is prepared. A plurality of land patterns 23 are formed on the surface 21 of the collective substrate 20A, and the collective substrate 20A A plurality of external terminals 26 are formed on the back surface 22 of the device. In addition, a plurality of internal wirings 25 are formed in the inner layer of the collective substrate 20A. In addition, the dotted line a shown in FIG. 3 is a part to be cut in the crystal cutting step later.

Next, as shown in FIG. 3, a plurality of electronic components 31 and 32 are mounted on the surface 21 of the collective substrate 20A in a manner of being connected to the land pattern 23. Specifically, after the solder 24 is supplied to the land pattern 23, the electronic components 31 and 32 are mounted, and the electronic components 31 and 32 are connected to the land pattern 23 by performing reflow.

Next, as shown in FIG. 4, the surface 21 of the assembly substrate 20A is covered with the magnetic molding resin 40 with the electronic components 31 and 32 embedded in it. The formation method of the magnetic mold resin 40 can be used: transfer molding, compression molding, injection molding, injection molding, vacuum injection molding, glue dispensing, slit nozzle application, and the like.

Then, as shown in FIG. 5, when the collective substrate 20A is cut along the broken line a to form the substrate 20 into pieces, the electronic circuit package 11A of this 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 structure of the composite magnetic sealing material constituting the magnetic mold resin 40.

As shown in Figure 6, the composite magnetic sealing material 2 constituting the magnetic molding resin 40 is It is composed of a resin material 4 and a magnetic filler 6 and a non-magnetic filler 8 blended in the resin material 4. Although there is no particular limitation, the resin material 4 preferably contains a thermosetting resin material as a main component. Specifically, it is preferable to use epoxy resin, phenol resin, urethane resin, polysiloxane resin or amide resin as the main component, and more preferably to use epoxy resin or phenol resin as the main ingredient for semiconductor sealing materials With hardener.

The best is to use epoxy resin with reactive epoxy groups at the end, combined with various hardeners and hardening accelerators. Examples of epoxy resins include: bisphenol A type, bisphenol F type, phenoxy, naphthalene, polyfunctional (dicyclopentadiene, etc.), biphenyl (bifunctional) and special structural types, Biphenyl, naphthalene, and dicyclopentadiene types that can be expanded with low thermal expansion are more useful. Examples of hardeners or hardening accelerators include, for example, amine compounds, alicyclic diamines, aromatic diamines, other amines (imidazole, tertiary amines), acid anhydride compounds (mainly high-temperature hardeners), Phenolic resin (novolak type, cresol novolak type, etc.), amine resin, dicyandiamide, Lewis acid complex. The kneading method of the material can be appropriately used: known methods such as a kneader, three-roller, and mixer.

The magnetic filler 6 is composed of an Fe—Ni-based material, and the metallic material containing Ni as a main component contains 32% by weight or more and 39% by weight or less. The remaining element is Fe, which accounts for 61 to 68% by weight. The mixing 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 system. The reason is that if the blending ratio of the magnetic filler 6 is less than 30% by volume, it is more difficult to obtain sufficient magnetic properties, and if the blending ratio of the magnetic filler 6 exceeds 85% by volume, it is more difficult to ensure fluidity and other necessary sealing materials. Various characteristics.

The metal material mainly composed of Ni may also contain a small amount of Co. That is, a part of Ni may be substituted with Co. In this way, the thermal expansion coefficient of the composite magnetic sealing material 2 can be further reduced. The addition amount of Co is preferably 0.1% by weight or more and 8% by weight or less with respect to the entire magnetic filler 6.

The shape of the magnetic filler 6 is not particularly limited, and it may be made into a spherical shape for high filling, and a filler with a plurality of particle size distributions may be blended and blended in a manner that becomes the densest filling. In addition, if the magnetic filler 6 is made into a substantially spherical shape, it is also possible to reduce damage when molding electronic parts. In particular, in order to achieve the densest packing or high packing, the shape of the magnetic filler 6 is preferably a sphere. The magnetic filler 6 preferably has a high tap density and a small specific surface area of the powder. The formation methods of the magnetic filler 6 include: water atomization method, gas atomization method, centrifugal disc spray method, etc. Among them, the best is the gas atomization method that can obtain high tap density and can reduce the specific surface area.

Although there is no particular limitation, the surface of the magnetic filler 6 can improve fluidity, adhesion, and insulation, and is conveniently coated with an insulating coating 7 made of metal oxides such as Si, Al, Ti, Mg, or organic materials. . In order to sufficiently increase the volume resistivity of the composite magnetic sealing material 2, it is preferable to set the film thickness of the insulating coating layer 7 to 10 nm or more. The insulating coating 7 can form an oxide film on the surface of the magnetic filler 6 by applying a thermosetting material coating treatment, or the dehydration reaction of a metal alkoxide of tetraethoxysilane or tetramethoxysilane , The best system is to form a coating film of silicon oxide. Moreover, it is more suitable to further perform organofunctional coupling treatment on it.

The composite magnetic sealing material 2 of this embodiment contains a non-magnetic filler 8. The non-magnetic filler 8 preferably uses SiO ₂ , ZrW ₂ O ₈ , (ZrO) ₂ P ₂ O ₇ , KZr ₂ (PO ₄ ) ₃ or Zr ₂ (WO ₄ )(PO ₄ ) _2, etc., and has a relatively high thermal expansion coefficient. A material smaller than the magnetic filler 6, or a material with a negative thermal expansion coefficient. If such a non-magnetic 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 alumina and magnesia can also be added; carbon black, pigments or dyes used for coloring; used to improve the smoothness, fluidity, dispersion and kneading properties of the surface with a particle size of 100nm or less Treated nano-silica; wax components used to improve mold release properties, etc. Among them, the composite magnetic sealing material constituting the magnetic molding resin 40 in the present invention does not necessarily contain a non-magnetic filler.

Furthermore, in order to improve the adhesion or fluidity, the surface of the magnetic filler 6 or the non-magnetic filler 8 may also be subjected to an organic functional coupling treatment. The organic functional coupling treatment may be performed by a known wet method or dry method, and it may also be a bulk blending method. In addition, in order to improve wettability, etc., the surface of the magnetic filler 6 or the non-magnetic filler 8 may be coated with a thermosetting resin.

When the non-magnetic filler 8 is added, the amount of the non-magnetic filler 8 relative to the total of the magnetic filler 6 and the non-magnetic filler 8 is preferably 1% by volume or more and 40% by volume or less. In other words, 1% by volume or more and 40% by volume or less of the magnetic filler 6 can be replaced with the non-magnetic filler 8. The reason is that if the addition amount of the non-magnetic filler 8 is less than 1% by volume, the effect of adding the non-magnetic filler 8 can hardly be obtained, and if the addition amount of the non-magnetic filler 8 exceeds 40% by volume, the amount of the magnetic filler 6 is too small, which is relatively low. It is difficult to ensure sufficient magnetic characteristics.

The shape of the composite magnetic sealing material 2 can be arbitrarily liquid or solid, and the main agent and hardening agent selected according to the molding method may have different shapes. Solid state composite The magnetic sealing material 2 can be formed into a tablet shape if it is used for transfer molding, and can be formed into a pellet shape if it is used for injection molding or compression molding. Also, regarding the molding method using the composite magnetic sealing material 2, there are methods using transfer molding, compression molding, injection molding, injection molding, vacuum injection molding, vacuum printing, printing, glue dispensing, slit nozzles, etc. , Can be selected appropriately. The molding conditions can be appropriately selected according to the combination of the main agent, hardener, and hardening accelerating material used, and post-curing may be performed as needed after molding.

FIG. 7 shows 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. When the magnetic filler 6 is substantially composed of Fe and Ni in the graph shown in FIG. 7, the amount of the magnetic filler 6 added is 70% by volume relative to the entire composite magnetic sealing material 2, and it means that no non-additive is added to the composite magnetic sealing material 2. The case of magnetic filler 8.

As shown in FIG. 7, when the Ni ratio of the magnetic filler 6 is 32% by weight or more and 39% by weight or less, the thermal expansion coefficient of the composite magnetic sealing material 2 specifically decreases, and becomes 10 ppm/°C or less depending on the conditions. Under these conditions, the lowest coefficient of thermal expansion (about 9.3ppm/°C) can be obtained when the Ni ratio is about 35% by weight. On the other hand, the correlation between the permeability system and the Ni ratio is relatively small, and the range of the Ni ratio shown in Fig. 7 is μ=12-13.

The reason is that in order to obtain such characteristics, when the Ni ratio is in the above-mentioned range, a constant steel characteristic that cancels the volume change caused by thermal expansion and magnetic strain will appear. This kind of material is called "Invar" (invar), and it is known as a high-precision material The mold material is not the material used as the magnetic filler formulated in the composite magnetic sealing material. The present invention focuses on the magnetic properties and low thermal expansion coefficient of Hengfan steel, and by using it as a magnetic filler material, a composite magnetic sealing material 2 with magnetic shielding properties and a small thermal expansion coefficient is realized.

FIG. 8 shows 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 shows that when the magnetic filler 6 is substantially composed of Fe and Ni, the addition amount of the magnetic filler 6 is 50% by volume, 60% by volume, or 70% by volume relative to the total composite magnetic sealing material 2, and indicates that the composite The non-magnetic filler 8 is not added to the magnetic sealing material 2.

As shown in FIG. 8, even if the addition amount of the magnetic filler 6 is any of 50% by volume, 60% by volume, and 70% by volume, when the Ni ratio of the magnetic filler 6 is 32% by weight or more and 39% by weight or less In the case of, the thermal expansion coefficient of the composite magnetic sealing material 2 will be specifically reduced. The value of the coefficient of thermal expansion is that the greater the amount of the magnetic filler 6 added, the lower. Therefore, when the addition amount of the magnetic filler 6 is small (for example, when it is 30% by volume), the thermal expansion coefficient of the composite magnetic sealing material 2 can be set by further adding a non-magnetic filler 8 composed of fused silica or the like. It should be less than 15ppm/℃. Specifically, if the total addition amount of the magnetic filler 6 and the non-magnetic filler 8 is 50% by volume or more and 85% by volume or less of the whole, the thermal expansion coefficient of the composite magnetic sealing material 2 can be sufficiently reduced (for example, 15ppm/ ℃ below).

FIG. 9 shows the relationship between the Ni ratio of the magnetic filler 6 and the magnetic permeability of the composite magnetic sealing material 2. The picture shown in Fig. 9 is the same as the picture shown in Fig. 8, when the magnetic filler 6 In the case of essentially consisting of Fe and Ni, the addition amount of the magnetic filler 6 is 50% by volume, 60% by volume, or 70% by volume relative to the total composite magnetic sealing material 2, and it means that there is no composite magnetic sealing material 2 The case of adding non-magnetic filler 8.

As shown in FIG. 9, even if the addition amount of the magnetic filler 6 is any of 50 vol %, 60 vol %, and 70 vol %, the correlation between the Ni ratio and the magnetic permeability is small. The value of the magnetic permeability is that the more the amount of the magnetic filler 6 added, the higher.

FIG. 10 shows 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. The graph shown in FIG. 10 shows that the sum of Ni and Co contained in the magnetic filler 6 is 37% by weight, and the addition amount of the magnetic filler 6 is 70% by volume relative to the entire composite magnetic sealing material 2, and it is shown in the composite magnetic sealing material 2 No non-magnetic filler 8 was added.

As shown in Fig. 10, it can be seen that when the Ni constituting the magnetic filler 6 is replaced by Co at 8% by weight or less compared to the case where Co is not contained in the magnetic filler 6 (Co=0% by weight), the reduction can be further reduced. The thermal expansion coefficient of the composite magnetic sealing material 2. However, if the substitution amount with Co is 10% by weight, the coefficient of thermal expansion will increase on the contrary. Therefore, the amount of Co added is preferably 0.1% by weight or more and 8% by weight or less with respect to the entire magnetic filler 6.

FIG. 11 shows the relationship between the addition ratio of the non-magnetic filler 8 and the thermal expansion coefficient of the composite magnetic sealing material 2. The graph shown in Fig. 11 shows that the sum of the magnetic filler 6 and the non-magnetic filler 8 is 70% by volume of the whole, and shows that the magnetic filler 6 is composed of 64% by weight of Fe and 36% by weight of Ni, and the non-magnetic filler 8 is composed of In the case of _{SiO 2 composition.}

As shown in FIG. 11, if the ratio of the non-magnetic filler 8 increases, the coefficient of thermal expansion decreases. However, if the ratio exceeds 40% by volume of the non-magnetic filler relative to 60% by volume of the magnetic filler, the effect of reducing the coefficient of thermal expansion is almost saturated. Therefore, the amount of the non-magnetic filler 8 relative to the total of the magnetic filler 6 and the non-magnetic filler 8 is preferably 1% by volume or more and 40% by volume or less.

FIG. 12 shows the relationship between the presence or absence of the insulating coating 7 on the surface of the magnetic filler 6 and the volume resistivity. The material of the magnetic filler 6 has two types of composition A (Fe=64% by weight, Ni=36% by weight) and composition B (Fe=63% by weight, Ni=32% by weight, and Co=5% by weight), insulating The coating 7 is SiO _{2 with a} thickness of 40 nm. Any magnetic filler 6 also has a cut-off diameter of 32 μm and a particle size D50 of 20 μm.

As shown in FIG. 12, it is known that both the composition A and the composition B are covered by the insulating coating 7, which greatly increases the volume resistivity of the magnetic filler 6. In addition, it was found that if the insulating coating 7 is used for coating, the pressure dependence during the measurement is also reduced.

FIG. 13 is a graph showing the relationship between the film thickness of the insulating coating 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% by weight of Fe and 36% by weight of Ni. The particle size of the magnetic filler 6 is the same as that of FIG. 12.

As shown in Figure 13, it is known that by using the magnetic filler 6 with an insulating coating of 10 nm or more The coating of the layer 7 greatly increases the volume resistivity of the magnetic filler 6. In particular, it is known that if the magnetic filler 6 is coated with an insulating coating 7 having a thickness of 30 nm or more, a very high volume resistivity can be obtained regardless of the pressure during the measurement.

FIG. 14 shows 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 is found that the volume resistivity of the magnetic filler 6 and the volume resistivity of the composite magnetic sealing material 2 have 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 set to 10 ¹⁰ Ω·cm or more. If the volume resistivity of the composite magnetic sealing material 2 is 10 ¹⁰ Ω·cm or more, when it is used as a molding material for electronic circuit packaging, sufficient insulation can be ensured.

As explained above, the electronic circuit packages 11A and 11B of this embodiment use the composite magnetic sealing material 2 with a very small thermal expansion coefficient as the material of the magnetic molding resin 40, so that it has magnetic shielding properties and prevents temperature changes. The substrate warping, the interface peeling of the plastic molding material, the cracking of the plastic molding material, etc.

<Second Embodiment>

Fig. 15 is a cross-sectional view showing the structure of an electronic circuit package 12A according to the second embodiment of the present invention.

As shown in FIG. 15, the electronic circuit package 12A of this embodiment is a magnetic mold The plane size of the resin 40 is slightly smaller than the plane size of the substrate 20, thereby exposing the outer periphery of the surface 21 of the substrate 20 to the magnetic mold resin 40, which is different from the electronic circuit package 11A of the first embodiment shown in FIG. Since the rest of the configuration is the same as the electronic circuit package 11A of the first embodiment, the same reference numerals are given to the same elements, and repeated descriptions are omitted.

As exemplified by the electronic circuit package 12A of this embodiment, in the present invention, the side surface 42 of the magnetic molding resin 40 does not necessarily have to form the same plane as the side surface 27 of the substrate 20, and the magnetic molding resin 40 may be made smaller.

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

First, as shown in FIG. 16, a pre-cut substrate 20 is prepared, and then a plurality of electronic components 31 and 32 are mounted in accordance with the land pattern 23 connected to the surface 21 thereof. Specifically, after the solder 24 is supplied to the land pattern 23, the electronic components 31 and 32 are mounted and reflow is performed to connect the electronic components 31 and 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 mounted on the mold 80. Then, as shown in FIG. 18, a composite magnetic material, which is a material of the magnetic mold resin 40, is injected from the flow path 81 of the mold 80, and pressurized and heated. In this way, the electronic circuit package 12A of this embodiment is completed.

According to this, it is also possible to form the magnetic mold resin after the 20 substrates are first sliced 40.

<The third embodiment>

Fig. 19 is a cross-sectional view showing the structure of the electronic circuit package 13A according to the third embodiment of the present invention.

As shown in FIG. 19, the electronic circuit package 13A of this embodiment is further provided with a metal film 60 covering the upper surface 41 and side surface 42 of the magnetic mold resin 40 and the side surface 27 of the substrate 20, which differs from that shown in FIG. The electronic circuit package 11A of the first embodiment is shown. In the internal wiring 25, the internal wiring 25 with a G appended to the end of the symbol is a power supply pattern, and a part of the internal wiring 25 is exposed on the side surface 27 of the substrate 20. The power supply pattern 25G is typically a land pattern to which a ground potential is provided, and as long as it belongs to a pattern to which a constant potential is provided, it is not limited to the land pattern. Since the rest of the configuration is the same as the electronic circuit package 11A of the first embodiment, the same reference numerals are given to the same elements, and repeated descriptions are omitted.

The metal film 60 is electromagnetic shielding, and it is preferable to use at least one metal selected from the group consisting of Au, Ag, Cu, and Al as the main component. The metal film 60 preferably has as low resistance as possible, and in view of cost and the like, it is best to use Cu. In addition, the outer surface of the metal film 60 is preferably made of corrosion-resistant metals such as SUS, Ni, Cr, Ti, and brass, or resins such as epoxy, phenol, imide, urethane, and silicone. It is covered by an anti-oxidant coating. This is to prevent the metal film 60 from being oxidized and degraded due to the external environment such as heat and humidity. In order to suppress and prevent this, it is preferable to perform the above-mentioned treatment. The method of forming the metal film 60 can be selected from well-known methods such as sputtering, vapor deposition, electroless plating, and electrolytic plating. Method, before forming the metal film 60, plasma treatment, coupling treatment, sandblasting treatment, etching treatment, etc., which are pretreatments for improving adhesion, may be performed. In addition, a high-adhesive metal film such as titanium, chromium, SUS, or the like may be thinly formed in advance as the base layer of the metal film 60.

As shown in FIG. 19, by first exposing the power supply pattern 25G on the side surface 27 of the substrate 20, the metal film 60 covers the side surface 27 of the substrate 20 and is connected to the power supply pattern 25G.

The resistance value at the interface between the metal film 60 and the magnetic mold resin 40 is preferably 10 ⁶ Ω or more. In this way, the eddy current generated by the electromagnetic noise incident on the metal film 60 hardly flows into the magnetic molding resin 40, and thus it is possible to prevent the magnetic characteristics of the magnetic molding resin 40 from degrading due to the inflow of the eddy current. The resistance value at the interface between the metal film 60 and the magnetic molding resin 40 refers to the surface resistance of the magnetic molding resin 40 when the two are in direct contact, and refers to the surface resistance of the insulating film when there is an insulating film between the two. In addition, the resistance value at the interface between the metal film 60 and the magnetic mold resin 40 is preferably 10 ⁶ Ω or more across the entire surface, but there may be regions with a resistance value of less than 10 ⁶ Ω.

The surface resistance value of the magnetic molding resin 40 is basically approximately the same as the volume resistivity of the magnetic molding resin 40. Therefore, if the volume resistivity of the magnetic resin mold 40 is at least ¹⁰ 10 Ω‧cm, substantially, the resistance value of the magnetic surface of the mold resin 40 is also more than ¹⁰ 10 Ω. However, as explained using FIG. 5, because the magnetic molding resin 40 is crystal cut during manufacture, the magnetic filler 6 will be exposed on the cut surface (ie side 42). In this case, if the volume resistivity is compared, the side The surface resistance of 42 may decrease. Similarly, for the purpose of low profile or roughening, when the upper surface 41 of the magnetic molding resin 40 is ground, the upper surface 41 will also expose the magnetic filler 6 made of soft magnetic metal. In this case, if the volume resistivity is compared , Then the surface resistance value of the upper 41 will be reduced. As a result, even if the volume resistivity of the magnetic molding resin 40 is 10 ¹⁰ Ω·cm or more, the surface resistance value of the magnetic molding resin 40 is still less than 10 ¹⁰ Ω. Even in this case, if the surface resistance of the magnetic molding resin 40 is If the value is 10 ⁶ Ω or more, the inflow of eddy current can be prevented.

Furthermore, when the surface resistance value of the upper surface 41 or the side surface 42 of the magnetic molding resin 40 is reduced to less than 10 ⁶ Ω, it is only necessary to form a thin insulating material on the upper surface 41 or the side surface 42 of the magnetic molding resin 40. FIG. 20 shows a cross-sectional view of the structure of the electronic circuit package 13B of the first modification. It is different from the figure where the 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. 19 shows the electronic circuit package 13A. 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 molding resin 40 is reduced to less than 10 ⁶ Ω, the interface between the metal film 60 and the magnetic molding resin 40 can still be The resistance value is 10 ⁶ Ω or more, which can prevent the magnetic properties from being degraded due to eddy currents.

Fig. 21 is a cross-sectional view showing the structure of an electronic circuit package 13C according to a second modification of this embodiment.

As shown in FIG. 21, the electronic circuit package 13C of the second modified example of this embodiment is based on the fact that the plane size of the magnetic mold resin 40 is slightly smaller than the plane size of the substrate 20, whereby the outer peripheral portion of the surface 21 of the substrate 20 is exposed to the magnetic The place where the resin 40 is molded is different from the electronic circuit package 13A shown in FIG. 19. Since the rest of the configuration is the same as that of the electronic circuit package 13A shown in FIG. 19, the same reference numerals are given to the same elements, and repeated descriptions are omitted.

As illustrated by the electronic circuit package 13C of this modification, in the present invention, the side surface 42 of the magnetic molding resin 40 does not need to form the same plane as the side surface 27 of the substrate 20, and the magnetic molding resin 40 may be smaller.

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

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

As shown in FIG. 23, the electronic circuit package 13E of the fourth modification of this embodiment is different from the electronic circuit package 13A 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. Since the rest of the configuration is the same as that of the electronic circuit package 13A shown in FIG. 19, the same reference numerals are given to the same elements, and repeated descriptions are omitted.

As exemplified by the electronic circuit package 13E of this modified example, the magnetic molding resin 40 in the present invention may also have a larger plane size than the substrate 20.

Accordingly, because the electronic circuit packages 13A~13E of this embodiment use magnetic The resin 40 is molded, and its surface is covered with the metal film 60, so that a composite shielding structure can be obtained. With this, it is possible to effectively block electromagnetic noise emitted from the electronic components 31 and 32 or incident on the electronic components 31 and 32 from the outside while realizing a low profile. In particular, the electronic circuit packages 13A to 13E of this embodiment can more effectively shield the electromagnetic noise emitted from the electronic components 31 and 32. The reason is that when the electromagnetic noise generated from the electronic parts 31 and 32 passes through the magnetic molding resin 40, part of the electromagnetic noise is absorbed, and part of the electromagnetic noise that is not absorbed is reflected by the metal film 60 and passes through the magnetic plastic again. Mold resin 40. Accordingly, since the magnetic molding resin 40 has an effect on the incident electromagnetic wave noise twice, it can effectively shield the electromagnetic wave noise emitted from the electronic components 31 and 32.

Furthermore, in the electronic circuit packages 13A to 13E of the present embodiment, if the volume resistivity of the magnetic mold resin 40 is set to 10 ¹⁰ Ω·cm or more, sufficient insulation required for the mold member can be ensured. Moreover, if the resistance value at the interface between the magnetic molding resin 40 and the metal film 60 is set to 10 ⁶ Ω or more, the eddy current generated by the electromagnetic noise incident on the metal film 60 hardly flows into the magnetic molding resin. 40 in. Therefore, it is possible to prevent the decrease in the magnetic characteristics of the magnetic molding resin 40 caused by the inflow of eddy current.

FIG. 24 is a diagram showing the amount of noise attenuation of the electronic circuit package 13A, showing that the thickness of the substrate 20 is 0.25 mm, and the thickness of the magnetic molding resin 40 is 0.50 mm. Regarding the metal film 60 as a laminated film of Cu and Ni, two types of metal films 60 having different Cu film thicknesses were evaluated. Specifically, the metal film 60 of the sample A has a laminated structure of 4 μm Cu and 2 μm of Ni, and the metal film 60 of the sample B has a laminated structure of 7 μm Cu and 2 μm of Ni. For comparison, it also shows the use of non-magnetic Sample C and D values of the molding material of filler 6. The metal film 60 of the sample C has a laminated structure of Cu of 4 μm and Ni of 2 μm, and the metal film 60 of the sample D has a laminated structure of Cu of 7 μm and Ni of 2 μm.

As shown in Fig. 24, compared with the case of using a molding material that does not contain a magnetic filler 6, it is known that if a composite magnetic sealing material 2 containing a magnetic filler 6 is used, the noise attenuation in the frequency band below 100MHz can be obtained. improve. Also, regarding the metal film 60, the thicker the thickness, the higher the noise attenuation characteristics can be obtained.

25 to 27 show the relationship between the film thickness of the metal film 60 contained in the electronic circuit package 13A and the amount of noise attenuation. Figure 25 shows the 20MHz noise attenuation, Figure 26 shows the 50MHz noise attenuation, and Figure 27 shows the 100MHz noise attenuation. For comparison, the value when using a molding material that does not contain the magnetic filler 6 is also shown.

As shown in FIGS. 25-27, it is known that the thicker the thickness of the metal film 60 in any frequency band, the higher the noise attenuation characteristics can be obtained. In addition, it is known that any frequency band is compared with the case of using a molding material that does not contain a magnetic filler 6. By using a composite magnetic sealing material 2 containing a magnetic filler 6, a higher noise attenuation characteristic can be obtained. .

FIG. 28 is a graph showing the amount of warpage 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 cooled. For comparison, FIG. 29 shows the value when the magnetic filler 6 is replaced with a non-magnetic filler _{composed of SiO 2.}

As shown in FIG. 28, it is known that the electronic circuit package 13A provided with the metal film 60 has less warpage of the substrate 20 due to temperature changes compared to the electronic circuit package 11A without the metal film 60. Also, from the comparison between FIG. 28 and FIG. 29, the warpage characteristics of the electronic circuit packages 11A and 13A using the composite magnetic sealing material 2 containing the magnetic filler 6 are almost the same as those of the plastic _{using the non-magnetic filler composed of SiO 2} Same as the mold material.

<Fourth Embodiment>

FIG. 30 is a cross-sectional view showing the structure of the electronic circuit package 14A according to the fourth embodiment of the present invention.

As shown in FIG. 30, the electronic circuit package 14A of this embodiment is the same as the electronic circuit package 13A of the third embodiment shown in FIG. 19 except for the difference in the shapes of the substrate 20 and the metal film 60. Therefore, the same symbols are assigned to the same elements, and repeated descriptions are omitted.

In this embodiment, the side surface 27 of the substrate 20 has a stepped shape. Specifically, it has a shape in which the lower side surface 27b protrudes more than the upper side surface 27a. Therefore, the metal film 60 is not formed on the entire side surface of the substrate 20, but is provided so as to cover the upper side surface 27a and the stepped portion 27c, and the lower side surface 27b is not covered by the metal film 60. In the present embodiment, the power supply pattern 25G is exposed on the upper side 27a of the substrate 20, so the metal film 60 is connected to the power supply pattern 25G via this portion.

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

First, after the magnetic molding resin 40 is formed on the surface 21 of the assembly substrate 20A by the method described using FIGS. 3 and 4, as shown in FIG. 31, a groove 43 is formed along the dotted line a indicating the position of the crystal cut. In this embodiment, since the power supply pattern 25G crosses the broken line a belonging to the crystal cutting position, if the aggregate substrate 20A is cut along the broken line a, the power supply pattern 25G is exposed from the side surface 27 of the substrate 20. The groove 43 is set to a depth that completely cuts the magnetic mold resin 40 and does not completely cut the assembly substrate 20A. Thereby, the side surface 42 of the magnetic mold resin 40, the upper side surface 27a and the step portion 27c of the substrate 20 are exposed in the groove 43. Here, the depth of the upper part 27a of the side surface must be set to at least the depth at which the power supply pattern 25G is exposed.

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

Then, by cutting the assembly substrate 20A along the broken line a to divide the substrate 20 into pieces, the electronic circuit package 14A of this embodiment is completed.

Accordingly, according to the manufacturing method of the electronic circuit package 14A of this embodiment, since the groove 43 is formed, the metal film 60 can be formed before the collective substrate 20A is sliced, and the metal film 60 can be easily and reliably formed.

Above, the preferred embodiments of the present invention are described, but the present invention is not limited In the above-mentioned embodiments, various changes can be made within the scope of not deviating from the spirit of the present invention, and of course these are also included in the scope of the present invention.

[Example] <Production of Composite Magnetic Sealing Material>

The main agent is 830S (bisphenol A epoxy resin) manufactured by DIC, and the hardening agent is 0.5 equivalent of DicyDD (dicyandiamide) manufactured by NIPPON CARBIDE Industry Co. The agent was C11Z-CN (imidazole) manufactured by Shikoku Chemical Industry Co., Ltd. at 1% by weight, and a resin material was prepared.

In the above resin material, 50% by volume, 60% by volume, or 70% by volume of the magnetic filler having the composition shown in FIG. 33 is added, and the paste is obtained by sufficiently kneading. In addition, butyl carbitol acetate is added in due course when it cannot be pasted. Apply the paste to a thickness of about 300μm, and heat curing at 100°C for 1 hour, 130°C for 1 hour, 150°C for 1 hour, and 180°C for 1 hour in order to obtain Hardened material flakes. Composition 1 (comparative example) is a magnetic material generally called "PB permalloy".

<Measurement of Thermal Expansion Coefficient>

Cut the above-mentioned hardened material sheet into a length of 12mm and a width of 5mm. Use TMA to increase the temperature from room temperature to 200°C at 5°C/min, and calculate the thermal expansion coefficient from the expansion in the temperature range of 50°C to 100°C lower than the glass transition temperature. . The measurement results are shown in Figure 34. Fig. 34 also shows the result of replacing the magnetic filler with a non-magnetic filler _{made of SiO 2.}

As shown in FIG. 34, the case of using the magnetic fillers of composition 2 and composition 3, the thermal expansion coefficient is greatly reduced compared with the case of using the magnetic filler of composition 1 (comparative example). In particular, when the addition amount is 60% by volume or more, the _{same thermal expansion coefficient as when a non-magnetic filler composed of SiO 2} is used can be obtained. When the addition amount is 70% by volume, the thermal expansion coefficient is 10 ppm/°C or less.

<Measurement of Magnetic Permeability>

The hardened product sheet was cut into a ring shape with an outer diameter of 7.9 mm and an inner diameter of 3.1 mm, and the material analyzer function of the impedance analyzer E4991 manufactured by Agilent was used to measure the effective permeability (μ') of 10 MHz. The measurement results are shown in Fig. 35.

As shown in FIG. 35, the permeability obtained when the magnetic fillers of composition 2 and 3 are used is almost the same as that obtained when the magnetic filler of composition 1 (comparative example) is used.

<Review>

The composite magnetic sealing material composed of the magnetic filler of composition 2 and composition 3 added to the resin material can obtain the _{same thermal expansion coefficient as when the non-magnetic filler composed of SiO 2} is used, and it can be obtained and used by PB The magnetic filler made of Permalloy has the same permeability. Therefore, if the composite magnetic sealing material composed of the magnetic filler of composition 2 or composition 3 is added to the resin material, it can be used as a sealing material for electronic circuit packaging to prevent substrate warpage, peeling of the mold material interface, and mold In the case of material cracks, etc., high magnetic shielding characteristics are obtained.

11A‧‧‧Electronic circuit packaging

20‧‧‧Substrate

21‧‧‧Substrate surface

22‧‧‧The back of the substrate

23‧‧‧Land Pattern

24‧‧‧Solder

25‧‧‧Internal wiring

26‧‧‧External terminal

27‧‧‧The side of the substrate

31、32‧‧‧Electronic parts

40‧‧‧Magnetic plastic molding resin

42‧‧‧The side of the magnetic plastic molding resin

Claims (5)

An electronic circuit package is provided with: a substrate; an electronic component mounted on the surface of the substrate; and a magnetic mold resin that covers the surface of the substrate and is embedded in the electronic component; wherein the magnetic mold resin The system is equipped with: a resin material; and a magnetic filler, which is blended in the above-mentioned resin material, and contains 32 to 39% by weight of a metallic material mainly composed of Ni in Fe. The electronic circuit package of claim 1, wherein the metal material further contains 0.1 to 8% by weight of Co relative to the entire magnetic filler. The electronic circuit package of claim 1, wherein the filler system further contains a non-magnetic filler. The electronic circuit package of claim 3, wherein the amount of the non-magnetic filler is 1-40% by volume relative to the total of the magnetic filler and the non-magnetic filler. The electronic circuit package of claim 3 or 4, wherein the total blending amount of the magnetic filler and the non-magnetic filler in the magnetic molding resin is 50 to 85% by volume.

Images