TWI714810B - Composite magnetic sealing material - Google Patents

Abstract

Disclosed herein is a composite magnetic sealing material 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 composite magnetic sealing material is 15 ppm/℃ or less.

Description

Composite magnetic sealing material

The present invention relates to a composite magnetic sealing material, and particularly relates to a composite magnetic sealing material suitable as a molding material for electronic circuit packaging.

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 circuits will increase in the future. Moreover, 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 referred to) Modularized electronic circuit modules will also increase in the future. These collectively referred to as electronic circuit packages will tend to be mounted at high density due to the high performance, miniaturization, and thinning of electronic devices such as smart phones. These tendencies show that unilateral misoperation and electromagnetic interference caused by noise tend to be more obvious, and it is difficult to prevent misoperation or electromagnetic interference with conventional noise countermeasures. Therefore, in recent years, there has been an evolution towards self-shielding of electronic circuit packaging. Although there are proposals to use conductive paste, plating, or sputtering to perform electromagnetic shielding, and they have already been put into practical use, higher shielding characteristics will be required in the future.

In order to achieve this requirement, in recent years, there have been proposals 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 may occur between the composite magnetic sealing material and the package substrate or electronic components. As a result, after the molding is formed, the state of the strip-shaped aggregate substrate may be warped or individualized. The later electronic circuit package will have a greater degree of warpage that is a problem with connectivity during installation and reflow. 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. 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 assembly substrate, and then performing individual chipping processing using dicing or the like.

Because 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 shrinkage of the mold material. To suppress this phenomenon, physical properties such as thermal expansion coefficient must be matched as much as possible. In recent years, organic multi-layer substrates used in semiconductor packages or electronic circuit modules have been increasingly thinning and multilayering due to their low profile requirements. In order to achieve high rigidity and low thermal expansion to ensure the handling of thin substrates while meeting this requirement, generally substrate materials with a higher glass transition temperature are used. Add filler with low thermal expansion coefficient to the substrate material, and use glass fiber cloth with 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 parts or the molding material, etc. . Semiconductor ICs use 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, low thermal expansion is required for molding materials, 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 general soft magnetic powder is added to a mold resin may not achieve the target low thermal expansion coefficient.

Therefore, the purpose of the present invention is to provide a composite magnetic sealing material with a low thermal expansion coefficient.

The composite magnetic sealing material of the present invention includes: a resin material and a filler blended in the resin material with a blending ratio of 30 to 85% by volume; wherein the filler contains a metal containing Ni as a main component in Fe The material is 32~39% by weight of the magnetic filler, whereby the thermal expansion coefficient of the composite magnetic sealing material is 15ppm/℃ or less.

According to the present invention, since a magnetic filler having a low thermal expansion coefficient is used, the thermal expansion coefficient of the composite magnetic sealing material can be set to 15 ppm/°C or less. Therefore, if the composite magnetic sealing material of the present invention is used as a molding material for electronic circuit packaging, it is possible to prevent warping of the substrate, peeling of the molding material interface, and cracking of the molding material.

In the present invention, the metal material may further contain 0.1 to 8% by weight of Co relative to the entire magnetic filler. In this way, the thermal expansion coefficient 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 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 composite magnetic sealing material can be further reduced while ensuring sufficient magnetic properties. In this case, the above-mentioned non-magnetic filler preferably contains 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 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 composite magnetic sealing material can be increased to, for example, 10 ¹⁰ Ω‧cm or more, and the insulating properties required by the plastic 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.

Accordingly, because the composite magnetic sealing material of the present invention has a small thermal expansion coefficient, if it is used as a plastic molding material for electronic circuit packaging, it can prevent substrate warping, plastic molding material interface peeling, plastic molding material cracks, etc. .

2‧‧‧Composite magnetic sealing material

4‧‧‧Resin material

6‧‧‧Magnetic filler

7‧‧‧Insulation coating

8‧‧‧Non-magnetic filler

10A, 10B‧‧‧Electronic circuit packaging

20‧‧‧Substrate

21‧‧‧Substrate surface

27‧‧‧Substrate side

30‧‧‧Electronic parts

40‧‧‧Magnetic plastic molding resin

41‧‧‧On top of magnetic plastic molding resin

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

60‧‧‧Metal Film

Fig. 1 is a schematic diagram illustrating the structure of a composite magnetic sealing material according to a preferred embodiment of the present invention.

Figure 2 shows the ratio of magnetic filler Ni and the thermal expansion of the composite magnetic sealing material The relationship between coefficient and permeability.

Fig. 3 is a graph showing the relationship between the ratio of the magnetic filler Ni and the thermal expansion coefficient of the composite magnetic sealing material.

Fig. 4 is a graph showing the relationship between the ratio of magnetic filler Ni and the permeability of the composite magnetic sealing material.

Fig. 5 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. 6 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.

Fig. 7 is a graph showing the relationship between whether an insulating coating is formed on the surface of the magnetic filler and the volume resistivity.

Fig. 8 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. 9 is a graph showing the relationship between the volume resistivity of the magnetic filler and the volume resistivity of the composite magnetic sealing material.

10A and B are schematic cross-sectional views showing the structure of an electronic circuit package using a composite magnetic sealing material.

Fig. 11 is a graph showing the amount of noise attenuation of the electronic circuit package.

FIG. 12 is a graph showing the relationship between the film thickness of the metal film contained in the electronic circuit package and the amount of noise attenuation.

FIG. 13 is a graph showing the relationship between the film thickness of the metal film contained in the electronic circuit package and the amount of noise attenuation.

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

15 is a graph showing the amount of warpage of the substrate when the electronic circuit package is heated and cooled.

16 is a graph showing the amount of warpage of the substrate when the electronic circuit package is heated and cooled.

Figure 17 shows a table of composition 1 to composition 3.

Fig. 18 is a table showing the measurement results of the examples.

Fig. 19 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.

Fig. 1 is a schematic diagram illustrating the structure of a composite magnetic sealing material according to a preferred embodiment of the present invention.

As shown in FIG. 1, the composite magnetic sealing material 2 of this embodiment is composed of a resin material 4 and a magnetic filler 6 and a non-magnetic filler 8 blended in the resin material 4. It is not particularly limited, and 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, silicone resin or amide resin as the main component, and more preferably to use epoxy resin or phenol resin as the main agent for semiconductor sealing materials With hardener.

The best system is to use epoxy resins with reactive epoxy groups at the ends, combined with various hardeners and hardening accelerators. Examples of epoxy resins include: bisphenol A type, bisphenol F type, phenoxy, naphthalene, polyfunctional (dicyclopentadiene, etc.), biphenyl type (bifunctional) and special structural type, More useful systems are biphenyl, naphthalene, dicyclopentadiene, etc. which can be expanded with low thermal expansion. 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), phenol resins (novolac type, cresol novolac type, etc.), amine resins, double Cyanamide, 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 metallic material mainly composed of Ni may also contain a small amount of Co. That is, 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 packing, and a filler with a plurality of particle size distributions may be blended and prepared so as to become the densest packing. 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 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 magnetic filler 6 are: water atomization method, gas atomization method, centrifugal disc spray Among them, the best is the gas atomization method that can achieve high tap density and can reduce the specific surface area.

Although not particularly limited, 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 a dehydration reaction of a metal alkoxide of tetraethoxysilane or tetramethoxysilane , The best is to form a coating film of silicon oxide. Moreover, it is more preferable to perform an organic functional 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, and the particle size is below 100nm. Surface-treated nano-silica; wax components used to improve mold release. However, the composite magnetic sealing material of 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 be subjected to organic functional coupling treatment. Organofunctional coupling treatment system only The well-known wet or dry implementation can be used, or the whole blending method can be used. 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 vol% or more and 40 vol% or less. In other words, 1% by volume or more and 40% by volume or less of the magnetic filler 6 can be replaced by 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 more 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 hardener selected according to the molding method may have different shapes. The solid composite magnetic sealing material 2 is formed into a tablet shape if it is used for transfer molding, and it is formed into a pellet shape if it is used for injection molding or compression molding. In addition, regarding the molding method using the composite magnetic sealing material 2, there are methods such as transfer molding, compression molding, injection molding, injection molding, vacuum injection molding, vacuum printing, printing, 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. 2 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. The graph shown in Fig. 2 shows that when the magnetic filler 6 is substantially composed of Fe and Ni, the amount of the magnetic filler 6 added is 70% by volume relative to the entire composite magnetic sealing material 2, and it shows that no non-additive is added to the composite magnetic sealing material 2. The case of magnetic filler 8.

As shown in FIG. 2, 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 is specifically reduced, 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. 2 is μ=12-13.

The reason is that in order to obtain such characteristics, when the Ni ratio is in the above-mentioned range, the constant steel characteristics that cancel the volume change caused by thermal expansion and magnetic strain will appear. This kind of material is called "invar steel" (invar). It is known as a mold material that requires high precision and is not a material that is used as a magnetic filler compounded in a 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 material of magnetic filler, a composite magnetic sealing material 2 with magnetic shielding properties and a small thermal expansion coefficient is realized.

FIG. 3 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. 3 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 The non-magnetic filler 8 is not added to the magnetic sealing material 2.

As shown in Figure 3, it is known that even if the addition amount of the magnetic filler 6 is 50% by volume, 60 In any one of volume% and 70 volume %, 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 is specifically reduced. The value of the coefficient of thermal expansion is that the more the amount of the magnetic filler 6 added, the lower. Therefore, when the addition amount of the magnetic filler 6 is small (for example, at 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 Below 15ppm/°C is sufficient. 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. 4 shows the relationship between the Ni ratio of the magnetic filler 6 and the magnetic permeability of the composite magnetic sealing material 2. The diagram shown in Fig. 4 is the same as the diagram shown in Fig. 3. When the magnetic filler 6 is substantially composed of Fe and Ni, the addition amount of the magnetic filler 6 is 50% by volume and 60% by volume relative to the entire composite magnetic sealing material 2 % Or 70% by volume, and means that the non-magnetic filler 8 is not added to the composite magnetic sealing material 2.

As shown in FIG. 4, even if the addition amount of the magnetic filler 6 is any one of 50% by volume, 60% by volume, and 70% by volume, 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. 5 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. 5 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 Not in Non-magnetic filler 8 may be added.

As shown in Figure 5, it is known 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 recombination can be further reduced The thermal expansion coefficient of the magnetic sealing material 2. However, if the substitution amount with Co is 10% by weight, the coefficient of thermal expansion will increase instead. Therefore, 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.

FIG. 6 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. 6 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 Fe and 36% by weight Ni, and the non-magnetic filler 8 is composed of In the case of SiO ₂ composition.

As shown in FIG. 6, if the proportion of the non-magnetic filler 8 increases, the coefficient of thermal expansion decreases. However, if the proportion 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. 7 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 kinds of composition A (Fe=64% by weight, Ni=36% by weight) and composition B (Fe=63% by weight, Ni=32% by weight, Co=5% by weight), insulating The coating 7 is SiO _{2 with a} thickness of 40 nm. Any magnetic filler 6 has a cut-off diameter of 32 μm and a particle size D50 of 20 μm.

As shown in FIG. 7, 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. It was also found that if the insulating coating 7 is used for coating, the pressure dependence during measurement is also reduced.

FIG. 8 shows 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. 8 shows the 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. 7.

As shown in FIG. 8, it is known that by covering the magnetic filler 6 with an insulating coating 7 of 10 nm or more, the volume resistivity of the magnetic filler 6 is greatly increased. In particular, it is known that if the magnetic filler 6 is coated with an insulating coating 7 of 30 nm or more, a very high volume resistivity can be obtained regardless of the pressure during the measurement.

FIG. 9 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. 9, 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, it can ensure sufficient insulation when used as a molding material for electronic circuit packaging.

FIG. 10A shows a schematic cross-sectional view of the structure of the electronic circuit package 10A using the composite magnetic sealing material 2. 10B shows a schematic cross-sectional view of the structure of the electronic circuit package 10B using the composite magnetic sealing material 2.

The electronic circuit package 10A shown in FIG. 10A includes a substrate 20, an electronic component 30 mounted on the substrate 20, and a magnetic mold resin 40 covering the surface 21 of the substrate 20 in a manner that the electronic component 30 is buried. The material of the magnetic molding resin 40 is the composite magnetic sealing material 2. On the other hand, the electronic circuit package 10B shown in FIG. 10B is further provided with a metal film 60 covering the upper surface 41 and side surface 42 of the magnetic molding resin 40, and the side surface 27 of the substrate 20, which is different from the electronic circuit package. 10A. The electronic circuit packages 10A and 10B both have a thickness of the substrate 20 of 0.25 mm, and a thickness of the magnetic mold resin 40 of 0.50 mm.

FIG. 11 is a graph showing the amount of noise attenuation of the electronic circuit package 10B. 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, the values of samples C and D using the molding material without magnetic filler 6 are also shown. The metal film 60 of the sample C has a layered composition of Cu of 4 μm and Ni of 2 μm, and the metal film 60 of the sample D has a layered composition of Cu of 7 μm and Ni of 2 μm.

As shown in Figure 11, compared to 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 is improved. . Furthermore, regarding the metal film 60, the thicker the thickness, the higher the noise attenuation characteristics can be obtained.

12 to 14 show the relationship between the thickness of the metal film 60 contained in the electronic circuit package 10B and the amount of noise attenuation. Figure 12 shows a 20MHz noise attenuation, Figure 13 shows a 50MHz noise attenuation, and Figure 14 shows a 100MHz noise attenuation. For comparison, the value when using a molding material without magnetic filler 6 is also shown.

As shown in FIG. 12 to FIG. 14, 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 compared to the case of using a plastic 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. .

15 is a graph showing the amount of warpage of the substrate 20 when the electronic circuit packages 10A and 10B are heated and cooled. For comparison, FIG. 16 shows the value when the magnetic filler 6 is replaced with a non-magnetic filler made of SiO ₂ .

As shown in FIG. 15, it is known that the electronic circuit package 10B provided with the metal film 60 has less warpage of the substrate 20 due to temperature changes compared to the electronic circuit package 10A without the metal film 60. In addition, from the comparison between FIG. 15 and FIG. 16, it is found that the warpage characteristics of the electronic circuit packages 10A, 10B using the composite magnetic sealing material 2 containing the magnetic filler 6 are almost the same as those of the electronic circuit packages 10A and 10B containing non-magnetic fillers composed of SiO ₂ It is the same as the molding material.

Above, the preferred embodiments of the present invention have been described. However, the present invention is not limited to the above-mentioned embodiments, and various changes can be made without departing from the spirit of the present invention. 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 hardener is 0.5 equivalent of DicyDD (dicyandiamide) manufactured by NIPPON CARBIDE Industry Co., Ltd. relative to the main agent. The hardening accelerator is used relative to the main agent. The agent was C11Z-CN (imidazole) manufactured by Shikoku Chemical Industry Co., Ltd. at 1 wt%, 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. 17 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" (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 from the expansion in the temperature range of 50°C to 100°C, which is lower than the glass transition temperature. coefficient. The measurement results are shown in Figure 18. Fig. 18 also shows the result of replacing the magnetic filler with a non-magnetic filler made of SiO ₂ .

As shown in FIG. 18, the case of using the magnetic filler 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 using a non-magnetic filler made of SiO ₂ 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 cured 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 effective permeability (μ') of 10 MHz was measured using the material analyzer function of the impedance analyzer E4991 manufactured by Agilent. The measurement results are shown in Fig. 19.

As shown in Fig. 19, the magnetic 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 the PB transparent material can be obtained and used. Magnetic alloys have the same permeability when forming magnetic fillers. Therefore, if a composite magnetic sealing material composed of magnetic fillers of composition 2 and composition 3 added to a resin material is used as a sealing material for electronic circuit packaging, it can prevent substrate warpage, mold interface peeling, and mold In the case of material cracks, etc., high magnetic shielding characteristics are obtained.

2‧‧‧Composite magnetic sealing material

4‧‧‧Resin material

6‧‧‧Magnetic filler

7‧‧‧Insulation coating

8‧‧‧Non-magnetic filler

Claims (6)

A composite magnetic sealing material contains: resin material; and magnetic filler, which is formulated in the above resin material, and contains 32 to 39% by weight of a metallic material mainly composed of Ni in Fe; the mixing ratio of the above magnetic filler is 30~85% by volume. The composite magnetic sealing material of claim 1, wherein the metal material further contains 0.1 to 8% by weight of Co relative to the entire magnetic filler. The composite magnetic sealing material of claim 1 or 2, wherein the magnetic filler has a plurality of particle size distributions. A composite magnetic sealing material is provided with: a resin material; a magnetic filler, which is formulated in the above resin material, and contains 32 to 39% by weight of a metal material mainly composed of Ni in Fe; and a non-magnetic filler, which is Blended in the resin material; 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, and the total blended amount of the magnetic filler and the non-magnetic filler is 50% of the total. ~85% by volume. The composite magnetic sealing material of claim 4, wherein the particle size of the non-magnetic filler is smaller than that of the magnetic filler. The composite magnetic sealing material of claim 4 or 5, wherein the magnetic filler has a plurality of particle size distributions.

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