TWI606918B - Composite magnetic sealing material - Google Patents

Description

Composite magnetic sealing material

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

In recent years, electronic devices such as smart phones have adopted high-performance wireless communication circuits and digital chips, and the operating frequency of semiconductor ICs used has also increased. In addition, in the system-in-package (SIP) positive acceleration which has a 2.5D structure or a 3D structure in which a plurality of semiconductor ICs are connected by a shortest wiring, it is predicted that the modularization of the power supply circuit will increase in the future. In addition, it is predicted that most electronic components (passive components such as inductors, capacitors, resistors, and filters; active components such as transistors and diodes; integrated circuit components such as semiconductor ICs; and components necessary for other electronic circuits) The modular electronic circuit modules will increase in size in the future. These electronic circuit packages, which are collectively referred to as "electronic devices," tend to be highly densely mounted due to the high functionality, miniaturization, and thinning of electronic devices such as smart phones. These tendencies indicate that erroneous actions and electromagnetic interference caused by noise are unilaterally unilateral, and conventional noise countermeasures are more difficult to prevent malfunction or electromagnetic interference. Therefore, in recent years, there has been a self-shielding evolution of electronic circuit packaging. Although it has been proposed to use electromagnetic paste, or plating or sputtering to perform electromagnetic shielding, and has been put into practical use, higher shielding characteristics will be required in the future.

In order to achieve this requirement, in recent years, there has been proposed an electronic circuit package in which a mold material has a magnetic shielding property. For example, the mold material for electronic circuit packaging disclosed in Patent Document 1 is a composite magnetic sealing material to which a soft magnetic powder having an oxidized film is added.

However, the conventional composite magnetic sealing material has a problem that the coefficient of thermal expansion is excessively large. Therefore, a thermal expansion coefficient mismatch occurs between the composite magnetic sealing material and the package substrate or the electronic component. As a result, after the molding, the state of the collective substrate having the strip shape is greatly warped or sliced. The latter electronic circuit package will have a large warpage of the degree of connectivity problem when mounting reflow. Hereinafter, this phenomenon will be described.

In recent years, various structures have been proposed for semiconductor packages or electronic component modules, and they have been put into practical use. At present, electronic components such as semiconductor ICs are generally mounted on an organic multilayer substrate, and then the upper and the periphery thereof are molded by a resin sealing material. Construction. The semiconductor package or the electronic component module having such a structure is formed by molding in a state of a collective substrate, and then performing dicing processing by dicing or the like.

This structure is made of a so-called "bimetal" composed of an organic multilayer substrate having different physical properties and a resin sealing material, and thus warpage occurs due to factors such as a difference in thermal expansion coefficient, glass transition, and hardening shrinkage of a molding material. In order to suppress this phenomenon, it is necessary to make physical properties such as a thermal expansion coefficient as uniform as possible. In recent years, organic multilayer substrates used in semiconductor packages or electronic circuit modules have been increasingly thinned and multi-layered due to the demand for low profile. In order to achieve high rigidity and low thermal expansion for ensuring the operability of a thin substrate in a state in which this requirement is achieved, a substrate material having a high glass transition temperature is generally used. A filler having a low coefficient of thermal expansion is added to the substrate material, and a glass fiber cloth having a lower coefficient of thermal expansion is used.

On the other hand, due to the poor physical properties between the semiconductor IC and the electronic components mounted on the substrate and the molding material, stress is generated, which causes various problems such as peeling of the interface of the molding material and cracking of the electronic component or the molding material. . In the semiconductor IC system, the coefficient of thermal expansion of the crucible is 3.5 ppm/° C., and the coefficient of thermal expansion of the calcined wafer component such as a ceramic capacitor or an inductor is about 10 ppm/° C.

Therefore, the molding material also requires low thermal expansion, and commercially available materials as low as 10 ppm/°C. The method of applying a low thermal expansion to a mold material is, of course, a method in which a low thermal expansion epoxy resin is used, and 0.5 ppm/° C. and a molten cerium oxide having a very low thermal expansion coefficient are blended in a sealing resin according to a high filling ratio.

[Previous Technical Literature] [Patent Literature]

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

On the other hand, the thermal expansion coefficient of a general magnetic material is high. Therefore, as described in Patent Document 1, a composite magnetic sealing material in which a general soft magnetic powder is added to a mold resin has a problem that a target low thermal expansion coefficient cannot be achieved.

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

The composite magnetic sealing material of the present invention comprises: a resin material and a filler blended in the resin material and having 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 to 39% by weight of the magnetic filler, whereby the composite magnetic sealing material has a thermal expansion coefficient of 15 ppm/° C. or less.

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

In the present invention, the metal material may further contain 0.1 to 8% by weight of Co based on the entire magnetic filler. In this way, the coefficient of thermal expansion of the composite magnetic sealing material can be further reduced.

In the present invention, the filler may further contain a nonmagnetic filler. According to this, the thermal expansion coefficient of the composite magnetic sealing material can be further reduced. In this case, the amount of the nonmagnetic filler is preferably from 1 to 40% by volume based on the total of the magnetic filler and the nonmagnetic filler. According to this, the thermal expansion coefficient of the composite magnetic sealing material can be further reduced while ensuring sufficient magnetic properties. In this case, the 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. Since the thermal expansion coefficients of the materials are very low or have 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 magnetic filler is preferably slightly spherical. According to this, the proportion of the magnetic filler in the composite magnetic sealing material can be increased.

In the present invention, the surface of the magnetic filler is preferably an insulating coating, and more preferably, the insulating coating has a film thickness of 10 nm or more. In this case, the volume resistivity of the composite magnetic sealing material can be increased to, for example, 10 ¹⁰ Ω ‧ cm or more, thereby ensuring the insulating properties required for the molding material for electronic circuit packaging.

In the present invention, the resin material is preferably a thermosetting resin material, and the thermosetting resin material preferably contains an epoxy resin, a phenol resin, a urethane resin, a polyoxymethylene resin, and a quinone imine resin. Select at least one material in the group.

Accordingly, since the composite magnetic sealing material of the present invention has a small coefficient of thermal expansion, if a molding material for electronic circuit packaging is used, it is possible to prevent warpage of the substrate, peeling of the interface of the molding material, cracking of the molding material, and the like. .

2‧‧‧Composite magnetic sealing material

4‧‧‧Resin materials

6‧‧‧Magnetic filler

7‧‧‧Insulation coating

8‧‧‧Non-magnetic filler

10A, 10B‧‧‧ electronic circuit package

20‧‧‧Substrate

21‧‧‧ substrate surface

27‧‧‧Side side of the substrate

30‧‧‧Electronic parts

40‧‧‧Magnetic Molding Resin

41‧‧‧Top of magnetic molding resin

42‧‧‧Side of magnetic molding resin

60‧‧‧Metal film

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic view showing the constitution of a composite magnetic sealing material according to a preferred embodiment of the present invention.

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

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

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

Fig. 5 is a graph showing the relationship between the magnetic filler Co ratio, the thermal expansion coefficient of the composite magnetic sealing material, and the magnetic permeability.

Fig. 6 is a graph showing the relationship between the addition ratio of the nonmagnetic filler and the coefficient of thermal expansion of the composite magnetic sealing material.

Fig. 7 is a graph showing the relationship between the volume resistivity and the presence or absence of the formation of an insulating coating on the surface of the magnetic filler.

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

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

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

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

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

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

Fig. 17 is a table showing the composition 1 to the 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, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic view showing the constitution 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 the present embodiment is composed of a resin material 4, a magnetic filler 6 blended in the resin material 4, and a non-magnetic filler 8. The resin material 4 is preferably a thermosetting resin material as a main component. Specifically, it is preferably an epoxy resin, a phenol resin, a urethane resin, a polyoxymethylene resin or a quinone imine resin as a main component, and more preferably an epoxy resin or a phenol resin-based semiconductor sealing material. With hardener.

The best system can be combined with various hardeners and hardening accelerators using an epoxy resin having a reactive epoxy group at the end. Examples of the epoxy resin include bisphenol A type, bisphenol F type, phenoxy group, naphthalene, polyfunctional type (dicyclopentadiene type, etc.), biphenyl type (bifunctional), and special structure type. More useful are biphenyl, naphthalene, dicyclopentadiene type, etc. which are capable of low thermal expansion. Examples of the hardener or the hardening accelerator include, for example, an amine compound alicyclic group. Diamine, aromatic diamine, other amine-based (imidazole, tertiary amine), acid anhydride-based compound (mainly high-temperature curing agent), phenol resin (novolac type, cresol novolak type, etc.), amine resin, double Cyanamide, Lewis acid complex. The kneading method of the material can be suitably used: a known method such as a kneader, a three-roll mill, or a mixer.

The magnetic filler 6 is made of an Fe—Ni-based material, and the metal material containing Ni as a main component contains 32% by weight or more and 39% by weight or less. The remaining 61 to 68% by weight of the element is Fe. The mixing ratio of the magnetic filler 6 is 30% by volume or more and 85% by volume or less based on the entire system of the composite magnetic sealing material 2. The reason is that if the mixing ratio of the magnetic filler 6 is less than 30% by volume, it is difficult to obtain sufficient magnetic properties, and if the mixing ratio of the magnetic filler 6 exceeds 85% by volume, it is difficult to secure a sealing material such as fluidity. Various characteristics.

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

The shape of the magnetic filler 6 is not particularly limited, and may be a spherical shape in order to perform high filling, and a filler having a plurality of particle size distributions may be blended and blended in such a manner as to be densely packed. Moreover, if the magnetic filler 6 is set to be slightly spherical, it is possible to reduce damage during molding of the electronic component. In particular, in order to achieve the most dense filling or high filling, the shape of the magnetic filler 6 is preferably a true sphere. The magnetic filler 6 preferably has a high tap density and a small specific surface area of the powder. The magnetic filler 6 is formed by a water atomization method, a gas atomization method, or a centrifugal disk spray. A method such as a method in which an optimum system can obtain a gas atomization method which has a high tap density and can reduce a specific surface area.

Although not particularly limited, the surface of the magnetic filler 6 is capable of improving fluidity, adhesion, and insulation, and is easily coated with an insulating coating 7 made of an oxide of a metal such as Si, Al, Ti, or Mg, or an organic material. In order to sufficiently increase the volume resistivity of the composite magnetic sealing material 2, it is preferable to set the thickness of the insulating coating 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 coating treatment of a thermosetting material or a dehydration reaction of a metal alkoxide of tetraethoxysilane or tetramethoxydecane. It is preferably formed by applying a coating film of cerium oxide. Further, it is more preferred to carry out an organofunctional coupling treatment thereon.

The composite magnetic sealing material 2 of the present embodiment contains the nonmagnetic 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 thermal expansion coefficient. A material smaller than the magnetic filler 6, or a material having a negative thermal expansion coefficient. When such a non-magnetic filler 8 is added to the composite magnetic sealing material 2, the coefficient of thermal expansion can be further reduced. Further, a flame retardant such as alumina or magnesia; carbon black, pigment or dye for coloring; for improving smoothness, fluidity, dispersion, and kneading property, and having a particle diameter of 100 nm or less may be added. Surface treated nano cerium oxide; wax component for improving mold release property. However, the composite magnetic sealing material of the present invention does not necessarily contain a non-magnetic filler.

Further, in order to improve adhesion or fluidity, an organic functional coupling treatment may be applied to the surface of the magnetic filler 6 or the non-magnetic filler 8. Organic functional coupling treatment system as long as It can be carried out by a known wet or dry method, or it can be an integral blending method. Moreover, the surface of the magnetic filler 6 or the nonmagnetic filler 8 may be coated with a thermosetting resin in order to improve wettability and the like.

When the nonmagnetic filler 8 is added, the amount of the nonmagnetic filler 8 is preferably 1% by volume or more and 40% by volume or less based on the total of the magnetic filler 6 and the nonmagnetic filler 8. In other words, 1% by volume or more and 40% by volume or less of the magnetic filler 6 may be substituted by the non-magnetic filler 8. The reason is that if the amount of the non-magnetic filler 8 is less than 1% by volume, the effect of adding the non-magnetic filler 8 is hardly obtained, and if the amount of the non-magnetic filler 8 is more than 40% by volume, the amount of the magnetic filler 6 is too small. It is difficult to ensure sufficient magnetic properties.

The form of the composite magnetic sealing material 2 may be any liquid or solid, and the main agent and the curing agent which are selected according to the compounding method may have different forms. The solid composite magnetic sealing material 2 is formed into a tablet shape for transfer molding, and is formed into a pellet shape for injection molding or compression molding. Moreover, the mold forming method using the composite magnetic sealing material 2 is a method using transfer molding, compression molding, injection molding, injection molding, vacuum injection molding, vacuum printing, printing, dispensing, slit nozzle, or the like. , can be chosen appropriately. The molding conditions may be appropriately selected in accordance with the combination of the main agent, the curing agent, and the curing accelerator, and may be post-cured after molding.

2 is a graph showing the relationship between the Ni ratio of the magnetic filler 6 and the thermal expansion coefficient and magnetic permeability of the composite magnetic sealing material 2. When the magnetic filler 6 shown in Fig. 2 is substantially composed only of Fe and Ni, the amount of the magnetic filler 6 added is 70% by volume with respect to the entire composite magnetic sealing material 2, and it means that no non-addition is added to the composite magnetic sealing material 2. The case of the 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 lowered, and it is 10 ppm/° C. or less depending on the conditions. Under the present conditions, the lowest coefficient of thermal expansion (about 9.3 ppm/° C.) can be obtained when the Ni ratio is about 35% by weight. On the other hand, regarding the correlation between the magnetic permeability ratio and the Ni ratio, the Ni ratio range shown in Fig. 2 is μ = 12 to 13.

The reason for this is that when such a characteristic can be obtained, when the Ni ratio is in the above range, the constant-state steel characteristic which is offset by the volume change caused by the thermal expansion and the magnetic strain appears. This material is called "invar" and is known as a mold material requiring high precision, and is not a material used as a magnetic filler formulated in a composite magnetic sealing material. The present invention satisfies the magnetic characteristics and the low thermal expansion coefficient of the constant steel, and by using it as a material of the magnetic filler, the composite magnetic sealing material 2 having magnetic shielding properties and a small thermal expansion coefficient is realized.

Fig. 3 is a graph showing the relationship between the Ni ratio of the magnetic filler 6 and the thermal expansion coefficient of the composite magnetic sealing material 2. When the magnetic filler 6 shown in FIG. 3 is substantially composed only of Fe and Ni, the amount of the magnetic filler 6 added is 50% by volume, 60% by volume, or 70% by volume based on the entire composite magnetic sealing material 2, and is expressed in the composite. The non-magnetic filler 8 is not added to the magnetic sealing material 2.

As shown in FIG. 3, it is found that even if the amount of the magnetic filler 6 added is 50% by volume, 60 In any of the 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, the thermal expansion coefficient of the composite magnetic sealing material 2 is specifically lowered. The value of the coefficient of thermal expansion is such that the amount of the magnetic filler 6 added is as low as possible. Therefore, when the amount of the magnetic filler 6 to be added is small (for example, at 30% by volume), the thermal expansion coefficient of the composite magnetic sealing material 2 is set as long as the nonmagnetic filler 8 composed of molten cerium oxide or the like is further added. It can be 15ppm/°C or less. Specifically, when the total amount of the magnetic filler 6 and the non-magnetic filler 8 is 50% by volume or more and 85% by volume or less, the thermal expansion coefficient of the composite magnetic sealing material 2 can be sufficiently reduced (for example, 15 ppm/ °C below).

Fig. 4 is a graph showing the relationship between the Ni ratio of the magnetic filler 6 and the magnetic permeability of the composite magnetic sealing material 2. 4 is the same as the diagram shown in FIG. 3. When the magnetic filler 6 is substantially composed only of Fe and Ni, the amount of the magnetic filler 6 added is 50% by volume and 60 volumes with respect to the entire composite magnetic sealing material 2. % or 70% by volume, and indicates that the nonmagnetic filler 8 is not added to the composite magnetic sealing material 2.

As shown in FIG. 4, it is found that even if the amount of the magnetic filler 6 added is 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 higher as the amount of the magnetic filler 6 added is larger.

Fig. 5 is a graph showing the relationship between the Co ratio of the magnetic filler 6 and the thermal expansion coefficient and magnetic permeability of the composite magnetic sealing material 2. The sum of Ni and Co contained in the magnetic filler 6 shown in FIG. 5 is 37% by weight, and the amount of the magnetic filler 6 added is 70% by volume with respect to the entire composite magnetic sealing material 2, and is shown in the composite magnetic sealing material 2 Not in the middle There is a case where the non-magnetic filler 8 is added.

As shown in Fig. 5, when Co (Co = 0% by weight) is not contained in the magnetic filler 6, when Ni constituting the magnetic filler 6 is replaced by Co of 8 wt% or less, the recombination can be further reduced. The coefficient of thermal expansion of the magnetic sealing material 2. However, if the substitution amount by Co is 10% by weight, the thermal expansion coefficient will increase. Therefore, the amount of Co added is preferably 0.1% by weight or more and 8% by weight or less based on the entire magnetic filler 6.

Fig. 6 is a graph showing the relationship between the addition ratio of the nonmagnetic filler 8 and the thermal expansion coefficient of the composite magnetic sealing material 2. 6 shows that the sum of the magnetic filler 6 and the non-magnetic filler 8 is 70% by volume of the whole, and it means 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 The case of SiO ₂ .

As shown in Fig. 6, when the ratio of the non-magnetic filler 8 is increased, the coefficient of thermal expansion is small. However, if the ratio exceeds 60% by volume of the magnetic filler and exceeds 40% by volume of the non-magnetic filler, the effect of lowering the coefficient of thermal expansion is almost saturated. Therefore, the amount of the nonmagnetic filler 8 is preferably 1% by volume or more and 40% by volume or less based on the total of the magnetic filler 6 and the nonmagnetic filler 8.

Fig. 7 is a graph showing the relationship between the volume resistivity and the formation of the insulating coating 7 on the surface of the magnetic filler 6. The material of the magnetic filler 6 is composed of 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), and insulation. The coating 7 is SiO _{2 having a} thickness of 40 nm. Any of the magnetic fillers 6 was cut to a diameter of 32 μm and a particle diameter D50 of 20 μm.

As shown in FIG. 7, it is known that either of the composition A and the composition B is coated with the insulating coating 7, and the volume resistivity of the magnetic filler 6 is greatly increased. It is also known that when the coating is applied by the insulating coating 7, the pressure dependency during measurement is also lowered.

Fig. 8 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. Fig. 8 is a view showing 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.

As shown in FIG. 8, it is found that the magnetic filler 6 is coated with the insulating coating 7 of 10 nm or more, and the volume resistivity of the magnetic filler 6 is greatly increased. In particular, it has been found that when the magnetic filler 6 is coated with the insulating coating 7 of 30 nm or more, a very high volume resistivity can be obtained irrespective of the pressure at the time of measurement.

Fig. 9 is a graph showing the relationship between the volume resistivity of the magnetic filler 6 and the volume resistivity of the composite magnetic sealing material 2.

As shown in FIG. 9, it is found that the volume resistivity of the magnetic filler 6 has a proportional relationship with the volume resistivity of the composite magnetic sealing material 2. In particular, when 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. When the volume resistivity of the composite magnetic sealing material 2 is 10 ¹⁰ Ω ‧ cm or more, sufficient insulating properties can be ensured when used as a molding material for electronic circuit packaging.

Fig. 10A is a schematic cross-sectional view showing the structure of an electronic circuit package 10A using a composite magnetic sealing material 2. Moreover, FIG. 10B is a schematic cross-sectional view showing 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 so as to cover the electronic component 30. The material of the magnetic molding resin 40 is a 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 the 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 each have a substrate 20 having a thickness of 0.25 mm and a magnetic mold resin 40 having a thickness of 0.50 mm.

Fig. 11 is a diagram showing the noise attenuation amount of the electronic circuit package 10B. The metal film 60 is a laminated film of Cu and Ni, and two kinds of metal films 60 having different Cu film thicknesses are evaluated. Specifically, the metal film 60 of the sample A has a composition of 4 μm of Cu and 2 μm of Ni, and the metal film 60 of the sample B has a structure of 7 μm of Cu and 2 μm of Ni. For comparison, the values of samples C and D using a molding material not containing the magnetic filler 6 are also shown. The metal film 60 of the sample C has a structure in which 4 μm of Cu and 2 μm of Ni are laminated, and the metal film 60 of the sample D has a structure of 7 μm of Cu and 2 μm of Ni.

As shown in FIG. 11, compared with the case of using a mold material not containing the magnetic filler 6, it is known that if the composite magnetic sealing material 2 containing the magnetic filler 6 is used, the amount of noise attenuation in the frequency band below 100 MHz is particularly improved. . Further, regarding the metal film 60, the thicker the thickness, the higher the noise attenuation characteristics can be obtained.

12 to 14 are diagrams showing the relationship between the film thickness of the metal film 60 included in the electronic circuit package 10B and the amount of noise attenuation. Figure 12 shows the amount of noise attenuation at 20 MHz, Figure 13 shows the amount of noise attenuation at 50 MHz, and Figure 14 shows the amount of noise attenuation at 100 MHz. For comparison, the values when using a molding material not containing the magnetic filler 6 are also shown.

As shown in FIGS. 12 to 14, it is known that the thicker the thickness of the metal film 60 in any of the frequency bands, the higher the noise attenuation characteristics can be obtained. Further, it is known that any of the frequency bands is higher than the use of the mold material containing no magnetic filler 6, and by using the composite magnetic sealing material 2 containing the magnetic filler 6, high noise attenuation characteristics can be obtained. .

FIG. 15 is a view 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 values when the magnetic filler 6 is replaced with a non-magnetic filler composed of SiO ₂ .

As shown in FIG. 15, it is known that the electronic circuit package 10B provided with the metal film 60 has a smaller warpage of the substrate 20 due to temperature changes than the electronic circuit package 10A in which the metal film 60 is not provided. Further, as seen from the comparison between Fig. 15 and Fig. 16, 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 the use of the non-magnetic filler composed of SiO ₂ . The molding material is the same.

The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit and scope of the invention.

[Examples] <Manufacture of composite magnetic sealing material>

The main agent used was 830S (bisphenol A type epoxy resin) manufactured by DIC Corporation, and the hardener was used as 0.5 equivalent of NIPPON CARBIDE Industrial Co., Ltd. DicyDD (dicyandiamide), and the hardening accelerator was used in relation to the main agent. The agent was a 1 wt% C11Z-CN (imidazole) manufactured by Shikoku Chemicals Co., Ltd., 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 was added, and the paste was sufficiently kneaded to obtain a paste. In addition, butyl carbitol acetate was added as appropriate when it was not possible to paste. The paste was applied to a thickness of about 300 μm, and each of them was subjected to thermal hardening at 100 ° C for 1 hour, at 130 ° C for 1 hour, at 150 ° C for 1 hour, and at 180 ° C for 1 hour. Hardened sheet. Composition 1 (Comparative Example) is a magnetic material generally referred to as "PB Permalloy".

<Measurement of thermal expansion coefficient>

The cured sheet was cut into a length of 12 mm and a width of 5 mm, and the temperature was raised from room temperature to 200 ° C at 5 ° C / minute, and the expansion was calculated from the expansion amount 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 Fig. 18. Also shown in Fig. 18 is the result of replacing the magnetic filler and using a nonmagnetic filler composed of SiO ₂ instead.

As shown in Fig. 18, in the case of using the magnetic filler of composition 2 and composition 3, the coefficient of thermal expansion was greatly reduced as compared with the case of using the magnetic filler of composition 1 (comparative example). In particular, when the amount of addition is 60% by volume or more, a thermal expansion coefficient equivalent to that when a nonmagnetic filler composed of SiO ₂ is used can be obtained, and when the amount is 70% by volume, the thermal expansion coefficient is 10 ppm/° C. or less.

<Measurement of magnetic permeability>

The cured sheet was cut into a ring shape having an outer diameter of 7.9 mm and an inner diameter of 3.1 mm, and a practical magnetic permeability (μ') of 10 MHz was measured using a material analyzer function of an 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 filler of composition 2 and composition 3 was used was almost the same as the magnetic permeability obtained when the magnetic filler of composition 1 (comparative example) was used.

<inspection>

A composite magnetic sealing material comprising a magnetic filler of composition 2 and composition 3 added to a resin material can obtain a thermal expansion coefficient equivalent to that when a nonmagnetic filler composed of SiO ₂ is used, and can be obtained and used by PB. The magnetic permeability of the magnetic alloy constitutes the same magnetic permeability. Therefore, when the composite magnetic sealing material comprising the magnetic filler of the composition 2 and the composition 3 is added to the resin material, it can be used as a sealing material for electronic circuit packaging, thereby preventing warpage of the substrate, peeling of the interface of the molding material, and molding. In the case of cracking or the like, high magnetic shielding properties are obtained.

2‧‧‧Composite magnetic sealing material

4‧‧‧Resin materials

6‧‧‧Magnetic filler

7‧‧‧Insulation coating

8‧‧‧Non-magnetic filler

Claims (18)

A composite magnetic sealing material comprising: a resin material; and a filler, which is formulated in the resin material, and has a compounding ratio of 30 to 85% by volume; wherein the filler contains a magnetic filler, and the magnetic filler is The Fe contains 32 to 39% by weight of a metal material containing Ni as a main component, whereby the composite magnetic sealing material has a thermal expansion coefficient of 15 ppm/° C. or less. The composite magnetic sealing material according to claim 1, wherein the metal material further contains 0.1 to 8% by weight of Co based on the entire magnetic filler. The composite magnetic sealing material according to claim 1, wherein the filler further contains a nonmagnetic filler, and the amount of the nonmagnetic filler is 1 to 40% by volume based on the total of the magnetic filler and the nonmagnetic filler. The composite magnetic sealing material of claim 3, wherein the non-magnetic filler 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 at least one material selected from the group consisting of. The composite magnetic sealing material of claim 1, wherein the magnetic filler has a shape that is slightly spherical. The composite magnetic sealing material of claim 1, wherein the surface of the magnetic filler is coated with an insulating coating. The composite magnetic sealing material according to claim 6, wherein the insulating coating has a film thickness of 10 nm or more. The composite magnetic sealing material according to claim 1, wherein the resin material is a thermosetting resin material. The composite magnetic sealing material of claim 8, wherein the above thermosetting resin material The material contains at least one material selected from the group consisting of epoxy resins, phenol resins, urethane resins, polyoxyxylene resins, and quinone imine resins. The composite magnetic sealing material of claim 1, wherein the volume resistivity is 10 ¹⁰ Ω ‧ cm or more. A composite magnetic sealing material comprising: a resin material; a magnetic filler which is formulated in the resin material and composed of a Fe-Ni-based material; and a non-magnetic filler which is formulated in the resin material; wherein The amount of the non-magnetic filler is 1 to 40% by volume based on the total of the magnetic filler and the non-magnetic filler, and the total amount of the magnetic filler and the non-magnetic filler is 50 to 85% by volume; the coefficient of thermal expansion is 15ppm/°C or less. The composite magnetic sealing material according to claim 11, wherein the magnetic filler is made of a material containing 32 to 39% by weight of a metal material containing Ni as a main component in Fe. The composite magnetic sealing material according to claim 11, wherein the surface of the magnetic filler is coated with an insulating coating having a thickness of 10 nm or more. The composite magnetic sealing material of claim 11, wherein the non-magnetic filler 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 at least one material selected from the group consisting of. A composite magnetic sealing material comprising: a resin material; a magnetic filler, which is formulated in the resin material, and contains 32 to 39% by weight of a metal material containing Ni as a main component in Fe; a non-magnetic filler, which is formulated in the above resin material; wherein the amount of the magnetic filler is 30 to 85% by volume; and the total amount of the magnetic filler and the non-magnetic filler is 50 to 85% by volume. . The composite magnetic sealing material according to claim 15, wherein the surface of the magnetic filler is coated with an insulating coating having a thickness of 10 nm or more. The composite magnetic sealing material of claim 15, wherein the non-magnetic filler 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 at least one material selected from the group consisting of. The composite magnetic sealing material according to claim 15, wherein the metal material further contains 0.1 to 8% by weight of Co with respect to the entire magnetic filler.