JP4611758B2 - Conductive noise suppressor and electronic component with conductive noise suppressor - Google Patents

Description

  The present invention relates to a conduction noise suppression body and an electronic component with a conduction noise suppression body.

  In recent years, with the widespread use of the Internet, high clock frequencies in the quasi-microwave band (0.3 to 10 GHz) such as personal computers, information appliances, wireless LAN, Bluetooth, optical modules, mobile phones, personal digital assistants, intelligent road information systems, etc. CPUs, electronic devices using high-frequency buses, and information communication devices using radio waves have become widespread, and ubiquitous societies that require high-performance digital devices and high-performance devices through low-voltage driving have come. .

  However, along with the widespread use of these devices, electromagnetic interference such as malfunctions to themselves or other electronic devices, effects on the human body, and the like caused by electromagnetic waves radiated from these devices has been a problem. Therefore, these devices are required not to emit unnecessary electromagnetic waves as much as possible so that they do not affect themselves, other electronic devices, or the human body, and do not malfunction even when receiving external electromagnetic waves. Methods for preventing such electromagnetic interference include electromagnetic shielding materials, that is, electromagnetic shielding materials that reflect electromagnetic waves, electromagnetic wave absorbing materials that absorb electromagnetic noise propagating in space, and conduction that suppresses high-frequency noise current flowing in wiring circuits. There is a method using a noise suppressor.

  In order to prevent electromagnetic interference, countermeasures (inter-system EMC) for shielding electromagnetic waves by providing an electromagnetic shielding material between the electronic equipment casing surface or the electronic equipment are performed between the electronic equipment. In electronic equipment, electronic components and wiring circuits are controlled by electromagnetic waves in order to suppress malfunctions due to their influence on each other and to prevent delays in processing speed or signal waveforms. Measures for covering with a shielding material (intra-system EMC) have been taken. In particular, in an electronic device, it is often performed to take measures against an electromagnetic noise suppressor on an electronic component itself that is an electromagnetic noise generation source because of its high efficiency (micro EMC).

  Recently, electronic devices and electronic parts have been required to have high performance, downsizing, and light weight. Electromagnetic noise suppressors used in these devices, particularly those that suppress conductive noise before becoming radiated noise. Similarly, a noise suppressor is required that has good electromagnetic wave absorption efficiency, is space-saving and lightweight, and can be easily and easily implemented for semiconductor chip integrated circuit measures or semiconductor package substrates. ing.

  It is known that an electromagnetic noise suppression body having a width narrower than the width of the wiring circuit is arranged in the vicinity of the wiring circuit to suppress the electromagnetic noise (see Patent Document 1). The electromagnetic noise suppressor is a soft magnetic thin film having a nano-granular structure with a thickness of 2 μm, in which a magnetic metal is deposited on a substrate together with ceramics and then heat-treated at a high temperature to recrystallize and disperse magnetic metal fine particles in the ceramics. Since the electromagnetic noise suppressor has a large magnetic permeability, if it is arranged in a shape narrower than the wiring circuit width, it is said that it is useful for countermeasures against conductive electromagnetic noise without reflection.

However, the width of the wiring circuit inside the semiconductor element is as narrow as 1 μm or less, and it is difficult to arrange an electromagnetic noise suppressor having a nano-granular structure with a width less than this with a required film thickness, Impossible. In addition, since the lines of electric force radiated from the wiring circuit (the magnetic lines of force are perpendicular to this) come out radially from the width of the wiring circuit, in order to increase the efficiency of magnetic loss, the electromagnetic noise suppressor is It goes without saying that a wider one is better. Furthermore, the temperature required for nano-granularization recrystallization is high, which may damage the semiconductor chip or the substrate of the semiconductor package. In addition, since the thickness of vapor deposition of the magnetic metal is in the micrometer unit, the time required for vapor deposition is long and the productivity is inferior.
JP 2002-151916 A

  Therefore, the object of the present invention is to reduce the conduction noise per volume, that is, the loss power ratio is large, is space-saving and lightweight, is provided inside the electronic component, and suppresses the conduction noise that is the source of radiation noise. An object of the present invention is to provide a conduction noise suppression body and an electronic component with a conduction noise suppression body that are easy and easy to take measures against electronic components (for example, an integrated circuit of a semiconductor element or a substrate of a semiconductor package).

The conductive noise suppressor of the present invention comprises an insulating substrate having a shear modulus of 1 × 10 ⁴ to 1 × 10 ¹⁰ Pa during physical vapor deposition, and a metal soft magnetic material is physically vapor-deposited on the insulating substrate. And a conductive noise suppression layer having a plurality of independent metal soft magnetic material clusters formed in this manner.
Here, the conductive noise suppression layer may be a layer formed by simultaneously vapor-depositing a metal soft magnetic material and a different material.
The loss power ratio at 1 GHz of the conduction noise suppressor of the present invention is preferably 0.3 to 0.9.

The electronic component with a conduction noise suppression body of the present invention includes a wiring circuit and the conduction noise suppression body of the present invention, and is radiated from a surface of the conduction noise suppression layer and a wiring circuit that is electromagnetically coupled to the conduction noise suppression layer. The conduction noise suppression body is arranged so that the lines of electric force are substantially orthogonal to each other.
Here, the width of the conduction noise suppression layer is desirably wider than the width of the wiring circuit that is electromagnetically coupled to the conduction noise suppression layer.
The distance between the conduction noise suppression layer and the wiring circuit that is electromagnetically coupled to the conduction noise suppression layer is preferably 0.1 to 200 μm.

  The conduction noise suppression body of the present invention has a high conduction noise suppression effect per volume, that is, a large loss power ratio, is space-saving and lightweight, is provided inside an electronic component, and has a conduction noise that is a source of radiation noise. Therefore, the countermeasure work for electronic components (for example, an integrated circuit of a semiconductor element or a substrate of a semiconductor package) is easy and easy to perform. Therefore, it is possible to sufficiently suppress conduction noise and radiation noise, and to take excellent EMC countermeasures.

If the conduction noise suppression layer is a layer formed by vapor-depositing a metal soft magnetic material and another material at the same time, the metal soft magnetic material clusters are stably dispersed. And can be reliably suppressed from growing into fine particles.
Further, when the shear elastic modulus of the insulating substrate at the time of physical vapor deposition is 1 × 10 ⁴ to 1 × 10 ¹⁰ Pa, the metal soft magnetic material clusters are stably dispersed. Growth to fine particles, metal thin films, etc. can be reliably suppressed.
When the loss power ratio at 1 GHz of the conduction noise suppressor of the present invention is 0.3 to 0.9, the conduction noise suppression effect is sufficiently exhibited.

In the electronic component with a conduction noise suppression body of the present invention, the conduction noise that is the source of the radiation noise is suppressed. Therefore, the electromagnetic wave radiated causes malfunction to itself or other electronic devices, influence on the human body, etc. Is suppressed. That is, sufficient conduction noise and radiation noise are suppressed, and excellent EMC countermeasures are taken.
If the width of the conduction noise suppression layer is wider than the width of the wiring circuit that is electromagnetically coupled to the conduction noise suppression layer, the conduction noise can be efficiently suppressed.
Moreover, if the distance between the conduction noise suppression layer and the wiring circuit electromagnetically coupled to the conduction noise suppression layer is 0.1 to 200 μm, the conduction noise can be efficiently suppressed.

The present invention will be described in detail below.
<Conduction noise suppressor>
The conductive noise suppression body of the present invention comprises an insulating base and a conductive noise suppression layer having a plurality of independent metal soft magnetic clusters formed by physically vapor-depositing a metal soft magnetic body on the insulating base. I have it.

(Conduction noise suppression layer)
The conductive noise suppression layer is formed by physically vapor-depositing a metal soft magnetic material on a relatively hard insulating substrate, and is formed by physically vapor-depositing a metal soft magnetic material on a relatively soft insulating substrate. The form is different from that of the fish. That is, when the insulating substrate is relatively hard, it is based on a plurality of independent nanometer-level metal soft magnetic material clusters on the insulating substrate and defects in which the metal soft magnetic material formed therebetween does not exist. The “metallic soft magnetic layer” is formed. On the other hand, when the insulating substrate is relatively soft, a plurality of independent nanometer-level metal soft magnetic material clusters and a part of the insulating substrate are mixed on the surface of the insulating substrate to form a composite “composite”. A layer "is formed.

(Metal soft magnetic layer)
FIG. 1 is a schematic view of a conductive noise suppression body of the present invention on which a metal soft magnetic layer is formed as viewed from the metal soft magnetic layer (upper surface) side. The conduction noise suppressor 1 includes an insulating base 2, a plurality of independent nanometer-level metal soft magnetic bodies 3 formed by physically vapor-depositing a metal soft magnetic body on the insulating base 2, and these clusters And a metal soft magnetic layer 4 made of defects existing between the two.

  As shown in the schematic diagram of FIG. 2, the metal soft magnetic material cluster 3 is formed by physically depositing a metal soft magnetic material on the insulating substrate 2 and forming a sufficient metal thin film. Not. FIG. 3 shows a state where the deposition amount of the metal soft magnetic material is further increased. Although the metal soft magnetic material clusters 3 are brought into contact with each other and are clustered to increase the cluster size, there are many defects in which the metal soft magnetic material does not exist between the grouped metal soft magnetic material clusters 3. Thus, the grouped metal soft magnetic clusters 3 are independent of each other. In the present invention, the clustered metal soft magnetic material clusters 3 are also treated as independent metal soft magnetic material clusters as long as defects exist between the clusters and each cluster is independent.

  Here, the metal soft magnetic material cluster is a group formed by collecting several tens to several hundreds of metal soft magnetic material atoms. As the aggregation of the metal soft magnetic material clusters proceeds, ultrafine particles, fine particles, and metal thin films are formed. However, the metal soft magnetic material clusters are clearly distinguished from ultrafine particles, fine particles, and metal thin films as described below. Is.

FIG. 4 is a field emission scanning electron microscope image obtained by observing the surface of the metal soft magnetic layer 4 formed on the insulating substrate 2. FIG. 5 is a high-resolution transmission electron microscope image of the cross section in the film thickness direction of the metal soft magnetic layer 4. FIG. 6 is an electron beam diffraction image of the metal soft magnetic layer 4. From FIG. 4 to FIG. 6, there are crystal lattices (metal soft magnetic material clusters) in which metal soft magnetic material atoms arranged at intervals of several kilometers are arranged as very small crystals, and defects in which the metal soft magnetic material does not exist in a very small range. Is recognized. That is, the metal soft magnetic material clusters are spaced apart from each other, and no clear grain boundary is observed. The crystal orientation of each metal soft magnetic material cluster is recognized to be disordered, and it has not grown into a homogeneous metal thin film, ultrafine particles, fine particles or the like made of metal soft magnetism.
The reason for the metal soft magnetic material cluster dispersed in this way is not clear, but even if it is a thin layer, it is derived from the structure and has increased magnetic anisotropy or exhibits magnetic properties due to a demagnetizing field. It seems to have a good conduction noise suppression effect.

  The thickness of the metal soft magnetic layer 4 is preferably 5 to 100 nm. By setting the thickness of the metal soft magnetic layer 4 to 5 nm or more, a sufficient conduction noise suppressing effect can be exhibited. On the other hand, when the thickness of the metal soft magnetic material layer 4 exceeds 100 nm, the metal soft magnetic material clusters 3 aggregate to form a homogeneous metal thin film made of the metal soft magnetic material, and return to the bulk metal soft magnetic material. As a result, the metal reflection becomes stronger and the conduction noise suppression effect becomes smaller, which is not effective. Here, the thickness of the metal soft magnetic layer 4 is an average thickness of the entire metal soft magnetic layer 4 including defects.

(Composite layer)
When the insulating substrate is relatively soft, that is, when the shear modulus of the insulating substrate is low, as shown in FIG. 8, which is a schematic diagram of the high-resolution transmission electron microscope image of FIG. The composite layer 5 is formed in a state where the soft magnetic material cluster is mixed with a part of the insulating substrate 2.

The composite layer 5 has a portion where a crystal lattice 6 (metal soft magnetic material cluster) in which ferromagnetic atoms arranged at intervals of several tens of millimeters are arranged as very small crystals, and a metal soft magnetic material within a very small range. The insulating soft substrate 2 includes a portion where only a part of the insulating base 2 is observed and a portion where the metal soft magnetic material atoms 7 are observed without being crystallized and dispersed in the insulating base 2. In other words, a grain boundary indicating that the soft metal magnetic material has a clear crystal structure is not observed, and a complex heterostructure in which the soft metal magnetic material and a part of the insulating substrate are integrated at the nanometer level ( It has a heterogeneous / asymmetric structure) and has not grown into a homogeneous metal thin film, ultrafine particle, fine particle, etc. made of a metal soft magnetic material.
The reason for the metal soft magnetic material cluster dispersed in this way is not clear, but even if it is a thin layer, it is derived from the structure and has increased magnetic anisotropy or exhibits magnetic properties due to a demagnetizing field. It seems to have a good conductive noise suppression effect.
The composite layer 5 is also formed when metal soft magnetism and a material different from this are vapor-deposited simultaneously (hereinafter referred to as insulating vapor deposition). The insulating vapor deposition will be described later.

  The thickness of the composite layer 5 is preferably 5 to 100 nm. By setting the thickness of the composite layer 5 to 5 nm or more, a sufficient conduction noise suppressing effect can be exhibited. On the other hand, when the thickness of the composite layer 5 exceeds 100 nm, the crystal lattice 6 (metal soft magnetic material cluster) aggregates to form a homogeneous metal thin film made of the metal soft magnetic material, and returns to the bulk metal soft magnetic material. As a result, the metal reflection becomes stronger and the conduction noise suppression effect becomes smaller, which is not effective.

  The thickness of the composite layer 5 is the average depth of penetration of metal soft magnetic atoms into the surface of the insulating substrate 2, and depends on the vapor deposition mass, binder material, physical vapor deposition conditions, etc. of the metal soft magnetic material. It depends on the deposition thickness of the metal soft magnetic material and is about 1.5 to 3.0 times. Here, the vapor deposition thickness of the metal-based soft magnetic material means a film thickness when the metal soft magnetic material is physically vapor-deposited on a hard base material in which metal soft magnetic material atoms do not enter.

(Insulating substrate)
The insulating substrate in the present invention means a substrate having a surface resistance of 10 ⁶ Ω / cm ² or more.
Examples of the insulating base 2 in the case where the metal soft magnetic layer 4 is formed include ceramics such as silicon oxide (such as quartz glass), silicon nitride, and alumina, and foamed ceramics.

Insulating substrate 2 for forming composite layer 5 includes polyolefin, polyamide, polyester, polyether, polyketone, polyimide, polyurethane, polysiloxane, phenolic resin, epoxy resin, acrylic resin, polyacrylate, vinyl chloride. Resins such as styrene-based resins and chlorinated polyethylene; diene rubbers such as natural rubber, isoprene rubber, butadiene rubber and styrene-butadiene rubber; organics such as non-diene rubber such as butyl rubber, ethylene propylene rubber, urethane rubber and silicone rubber Examples include polymers. These may be thermoplastic, thermosetting, or uncured products thereof. Further, it may be a modified product such as the above-mentioned resin or rubber, a mixture, or a copolymer.
The thickness of the insulating substrate 2 is only required to be insulative, and may be 0.1 μm or more.

Among them, the insulating base 2 is preferably one having a low shear modulus in physical vapor deposition in order to inhibit the aggregation and growth of the metal soft magnetic material cluster and stabilize the dispersion of the metal soft magnetic material cluster. . Specifically, those having a shear modulus of 1 × 10 ¹⁰ Pa or less are preferable. In order to obtain a desired shear modulus, the insulating substrate 2 can be heated to, for example, 100 to 300 ° C. as necessary, but may be heated to a temperature at which decomposition, evaporation, viscosity reduction, etc. do not occur. is necessary. When physical vapor deposition is performed at room temperature, the insulating base 2 is preferably an elastic body having a rubber hardness of about 80 ° (JIS-A) or less.

The following methods are known as methods for measuring the shear modulus.
(1) The tensile elastic modulus is obtained from the relationship between the tensile stress and strain defined in JIS K7113, and the shear elastic modulus is obtained from the following formula based on this.
Shear modulus = Tensile modulus / (2 x (1 + Poisson's ratio))
Here, the value of 2 × (1 + Poisson's ratio) is approximately 2.6 to 3.0 from a rigid polymer to a rubbery elastic body.
(2) Using a viscoelasticity measuring device capable of grasping the temperature characteristics, the shear modulus is measured with the test mode set to the shear mode.
(3) Using a viscoelasticity measuring device, set the test mode to the tensile mode, measure the storage elastic modulus G ′ and the loss elastic modulus G ″, obtain the complex elastic modulus G * from the following formula, and determine the complex elastic modulus as the tensile elasticity As a modulus, the shear modulus is obtained from the above formula.
G * = √ ((G ′) ² + (G ″) ² )
The shear elastic modulus in the present invention is a value measured using a solid analyzer RSA-II manufactured by Rheometric Scientific as a viscoelasticity measuring device in a shear mode under a measurement frequency of 1 Hz.

In addition, the insulating substrate 2 is subjected to shearing after physical vapor deposition of the metal soft magnetic material so that aggregation of the metal soft magnetic material cluster, that is, homogenization, can be suppressed even when thermal and mechanical stress is applied. Those having an elastic modulus higher than 1 × 10 ⁴ Pa are preferred. By increasing the shear modulus after physical vapor deposition of the metal soft magnetic material, it is possible to reliably prevent the nanometer level metal soft magnetic material atoms or clusters from aggregating and crystallizing and growing into fine particles and metal thin films. Can do. More preferably, it is 1 × 10 ⁷ Pa or more in the temperature range in which the conduction noise suppressor is used.
In order to obtain a desired shear modulus, it is preferable that the insulating substrate 2 is fired and solidified or chemically crosslinked after physical vapor deposition of the metal soft magnetic material. In this respect, it is particularly preferable to use an organic polymer that has a low shear modulus at the time of vapor deposition and can be cross-linked after the vapor deposition to increase the shear modulus, such as thermosetting resin, energy beam (ultraviolet ray, electron beam, etc.). ) A curable resin is preferred.

When the insulating substrate 2 is an organic polymer, the gas permeability can be used as an index indicating the size of the intermolecular voids in which the metal soft magnetic material atoms enter and an independent metal soft magnetic material cluster can easily be formed. . Originally, it is preferable to check the intermolecular gap of the organic polymer by the permeability of argon gas and krypton gas equivalent to the size of the metal soft magnetic material atoms, but these gases are generally used for measuring the gas permeability. For example, carbon dioxide permeability data can be used instead. Examples of the organic polymer having a large carbon dioxide permeability at room temperature include polyphenylene oxide, polymethylpentene having a carbon dioxide permeability of 1 × 10 ⁻⁹ [cm ³ (STP) cm / (cm ² × s × cmHg)] or more. Nylon 11, a mixture or copolymer of rubber components such as high impact polystyrene and other components, polybutadiene or polyisoprene of 1 × 10 ⁻⁸ [cm ³ (STP) cm / (cm ² × s × cmHg)] or more Styrene butadiene rubber, silicone rubber and the like. Among them, rubbers such as silicone rubber are particularly preferable from the viewpoint of shear modulus.

Further, from the viewpoint of preventing oxidation of the metal soft magnetic material atoms, an organic polymer having low oxygen permeability is preferable. Examples of such an organic polymer include polyethylene, polytrifluorochloroethylene, polymethyl methacrylate, oxygen permeability of 1 × 10 ⁻¹⁰ [cm ³ (STP) cm / (cm ² × s × cmHg)] or less. × 10 ⁻¹² [cm ³ (STP) cm / (cm ² × s × cmHg)] The following polyethylene terephthalate, polyacrylonitrile and the like can be mentioned.
Here, the carbon dioxide gas permeability and the oxygen permeability are gas permeability coefficients measured and determined in accordance with JIS K7126.

  Furthermore, a silane coupling agent, a titanate coupling agent, a nonionic surfactant, a polar resin oligomer, etc. are blended in the insulating substrate 2 and reacted with the metal soft magnetic material to stabilize the metal soft magnetic material cluster. You may let them. By blending such an additive, formation of a homogeneous metal thin film is prevented, and oxidation of the metal soft magnetic material is advantageously prevented. In addition, a reinforcing filler, a flame retardant, an anti-aging agent, an antioxidant, a colorant, a thixotropy improver, a plasticizer, a lubricant, a heat improver and the like may be appropriately added to the insulating substrate 2.

  When the insulating substrate 2 is a hard substrate such as ceramics (for example, quartz glass), the metal soft magnetic material atoms do not enter the insulating substrate 2, and the metal soft magnetic material cluster 3 aggregates and is homogeneous. Although it is easy to form a metal thin film, by keeping the vapor deposition mass of the metal soft magnetic material low, independent metal soft magnetic material clusters 3 are formed and the interval between the metal soft magnetic material clusters 3 is widened. It will be in the state which is hard to aggregate. The vapor deposition mass of the metal soft magnetic material when the insulating substrate 2 is ceramic will be described later.

  Further, even when the insulating substrate 2 is a hard substrate such as ceramics, if the metal soft magnetic material and a material different from this are vapor-deposited simultaneously to form the composite layer 5, It is possible to reliably suppress the metal soft magnetic material cluster from being stably dispersed, agglomerating and crystallizing, and growing into fine particles, a metal thin film or the like. Specifically, a chemical vapor deposition method (CVD) in which a reactive gas is introduced at the time of physical vapor deposition and partially reacts with the surface of the metal soft magnetic material cluster to the extent that the magnetic effect is not lost can be employed. Examples of the gas include nitrogen gas, methane gas, acetylene gas, silane gas, fluorocarbon gas, and paraxylylene.

(Physical vapor deposition)
First, a general description of physical vapor deposition (PVD) will be given.
In general, the physical vapor deposition method is a method in which a vaporized material is vaporized by some method in a vacuumed container, and the vaporized vaporized material is deposited on a substrate placed nearby to form a thin film. Depending on the vaporization method, it can be divided into an evaporation system and a sputtering system. Examples of the evaporation system include EB vapor deposition and ion plating. Examples of the sputtering system include high-frequency sputtering, magnetron sputtering, and counter target type magnetron sputtering.

  In EB vapor deposition, since the energy of the evaporated particles is as small as 1 eV, the substrate is less damaged and the film tends to be porous and the film strength tends to be insufficient, but the specific resistance of the film is increased.

  According to the ion plating, the argon gas and the ions of the evaporated particles are accelerated and collide with the substrate. Therefore, the energy is larger than that of EB, the particle energy is about 1 KeV, and a film having strong adhesion can be obtained. The adhesion of micro-sized particles called droplets cannot be avoided, and there is a possibility that the discharge stops.

  Magnetron sputtering is characterized by a high growth rate and high particle energy of several tens of eV because the plasma (strong evaporation) is generated under the influence of a magnetic field although the utilization efficiency of the target (evaporation material) is low. In the high frequency sputtering, an insulating target can be used.

  Among magnetron sputtering, facing target type magnetron sputtering generates plasma between facing targets, encloses the plasma by a magnetic field, puts the substrate outside between facing targets, and generates the desired thin film without being damaged by plasma. It is a method to do. Therefore, it is possible to produce a dense target composition having the same composition as the target composition without resputtering the thin film on the substrate, with a faster growth rate, and without causing collisional relaxation of the sputtered atoms.

  In the present invention, these physical vapor deposition methods are used to form independent metal soft magnetic material clusters on the insulating substrate 2 without forming a metal thin film of the metal soft magnetic material. Therefore, among the above physical vapor deposition methods, in the method for producing a conduction noise suppressor of the present invention, ion plating, magnetron sputtering, and opposed target type magnetron sputtering are preferred for the following reasons, and particularly opposed target type magnetron sputtering. Is preferred.

  The covalent bond energy in an organic polymer is about 4 eV. Specifically, the bond energies of C—C, C—H, Si—O, and Si—C are 3.6 eV, 4.3 eV, and 4.6 eV, respectively. 3.3 eV. On the other hand, in ion plating, magnetron sputtering, and opposed target type magnetron sputtering, the evaporated particles have high energy. Therefore, when the insulating substrate 2 is made of an organic polymer, a part of the organic polymer is used. It is considered that chemical bonds are broken and collide.

  Therefore, in the present invention, if the insulating base 2 made of an organic polymer has a sufficiently low shear modulus, when the metal soft magnetic material is deposited, the organic polymer vibrates and moves, and the metal soft magnetic atoms and A local mixing action with the organic polymer occurs, and the metal soft magnetic material atoms enter from the surface of the insulating substrate 2 to about 0.01 to 0.3 μm. In a metal thin film made of a homogeneous metal soft magnetic material, The composite layer 5 having a nanometer-level heterostructure is formed.

Examples of the metal soft magnetic material used as an evaporation material (target) in the vapor deposition step include iron, carbonyl iron; Fe—Ni, Fe—Co, Fe—Cr, Fe—Si, Fe—Al, Fe—Cr—Si, Fe -Iron alloys such as Cr-Al, Fe-Al-Si, Fe-Pt; cobalt, nickel, or alloys thereof. It is preferable to use nickel alone because it is resistant to oxidation.
When the metal soft magnetic material is vapor-deposited on the insulating substrate 2, the metal soft magnetic material is vapor-deposited as plasma or ionized metal soft magnetic atoms, so the composition of the vapor-deposited metal soft magnetic material is The composition ratio of the metal soft magnetic material used as the vapor deposition material is not always the same.

  When the insulating substrate 2 is an organic polymer, the vapor deposition mass of the metal soft magnetic material is preferably 5 to 100 nm in terms of the thickness of the metal soft magnetic material alone. On the other hand, when the insulating substrate 2 is ceramic, in order to suppress the aggregation of the metal soft magnetic material cluster 3, the vapor deposition mass of the metal soft magnetic material is preferably 5 to 50 nm in terms of the thickness of the metal soft magnetic material alone.

Since the effect of suppressing conduction noise is reduced when the deposition mass is reduced, a plurality of metal soft magnetic layers 4 or composite layers 5 are laminated, or metal soft magnetic materials are deposited on both surfaces of the insulating substrate 2. As a result, the total mass of the metal soft magnetic material can be increased. Although this total mass depends on the level of required conduction noise suppression effect, it is preferably about 10 to 500 nm in terms of a total film thickness conversion value. Lamination can be performed by depositing a metal soft magnetic material on the insulating substrate 2, then providing the same or different insulating substrate thereon, and again depositing the metal soft magnetic material thereon.
Here, the vapor deposition mass is obtained by vapor-depositing a metal soft magnetic material on a hard substrate such as glass or silicon under the same conditions, and measuring and averaging the deposited thickness.

  As the insulating substrate 2 used for vapor deposition, a film or a sheet-like substrate is preferable because vapor deposition efficiency is good. The thickness is preferably 1 to 100 μm. When the insulating substrate 2 is thin, or in the case of individual parts such as a semiconductor wafer, the insulating substrate 2 may be provided on the carrier sheet for handling.

(Loss power ratio)
The measurement of the reflection attenuation amount S11 and the transmission attenuation amount S21, which is a measure of the conduction noise suppression effect, is being standardized by IEC (International Electrotechnical Commission) Working Group 10 and Technical Committee 51, and was published in 2005. Is scheduled.
FIG. 9 is a schematic configuration diagram showing an apparatus used for the measurement of the reflection attenuation S11 and the transmission attenuation S21 under consideration. A conductive noise suppressor 1 (50 mm × 50 mm) is placed in close contact with a microstrip line 12 having a specified characteristic impedance (50Ω, etc.) provided in the test fixture 11 and the conductive noise suppressor 1 is mounted. Changes in the front and rear S parameters (reflection attenuation amount S11 and transmission attenuation amount S21) are measured by a network analyzer 13 electrically connected to the microstrip line 12.

In the present invention, this method was adopted, and the loss power ratio described in “Industrial Materials” (November 2002 issue, Nikkan Kogyo Shimbun) was obtained by the following formula.
The loss power ratio takes a value of 0 to 1, and is represented by the following formula.
Loss power ratio (Ploss / Pin) = 1- (| Γ | ² + | Τ | ² )
Here, S11 = 20log | Γ |, S21 = 20log | Τ |, Γ is a reflection coefficient, and Τ is a transmission coefficient.

In order to sufficiently exhibit the conduction noise suppression effect in the quasi-microwave band, the loss power ratio at 1 GHz is preferably 0.3 or more. If it is smaller than this, it cannot be said that there is a sufficient conduction noise suppression effect. Furthermore, the loss power ratio is preferably 0.4 or more. If the loss power ratio is 0.4 or more, there is a sufficient conduction noise suppression effect. The current technology cannot achieve a loss power ratio exceeding 0.9 at 1 GHz.
In order to set the loss power ratio of the conduction noise suppression body to 0.3 to 0.9, a metal soft magnetic material is physically vapor-deposited on the insulating substrate 2 to disperse the metal soft magnetic material cluster. On the basis of this, it is achieved by controlling the physical vapor deposition conditions and the physical properties of the insulating substrate 2.

<Electronic parts with conductive noise suppression body>
The conduction noise suppression body of the present invention can suppress high-frequency noise current flowing in the conductor of the electronic component and the wiring circuit of the electronic device in which the electronic component is mounted, due to magnetic loss that is a magnetic property. In addition, radiation noise due to resonance or the like accompanying reflection at a location where the impedance of the high-frequency current is irregular can be suppressed.

Here, the electronic component includes a wiring circuit, and examples thereof include an electronic element and a printed board on which the electronic element is mounted. In particular, in semiconductor devices, countermeasures against noise are required by increasing the frequency of signals from high speed.
As the signal wiring circuit, a microstrip line is usually employed. FIG. 10 is a diagram illustrating an example of an electronic component with a conduction noise suppression body. This electronic component with a conductive noise suppression body includes a ground layer 20, an insulating layer 21, a wiring circuit 22, and a conductive noise suppression body 1 embedded in the insulating layer 21.

  In this electronic component with a conduction noise suppression body, electric lines of force 31 extend radially from the wiring circuit 22 and magnetic lines of force 32 are generated perpendicular thereto. In order to efficiently suppress noise electromagnetically, it is preferable that the magnetic lines of force 32 are in contact with the conduction noise suppressing body 1 as long as possible. Therefore, the surface of the conductive noise suppression layer 1 of the conductive noise suppression body 1 and the electric lines of force 31 radiated from the wiring circuit 22 electromagnetically coupled to the conductive noise suppression layer are substantially orthogonal (the surface of the conductive noise suppression layer). The conduction noise suppression body 1 needs to be disposed so that the magnetic field lines are substantially parallel to each other. Here, substantially orthogonal means a range of 90 ° ± 10 °, and substantially parallel means a range of 0 ° ± 10 °.

Further, in order to efficiently suppress noise electromagnetically, it is preferable to dispose the conduction noise suppression body 1 in the vicinity of the wiring circuit 22 so as to cross many electric force lines 31 and magnetic field lines 32 that spread. Therefore, it is preferable that the width of the conductive noise suppression layer of the conductive noise suppression body 1 is wider than the width of the wiring circuit 22 that is electromagnetically coupled to the conductive noise suppression layer. Further, by making the conduction noise suppression body 1 as long as possible not only in the width direction of the wiring circuit 22 but also in the longitudinal direction, contact with the electric lines of force 31 and the lines of magnetic force 32 can be widened, and the effect of suppressing conduction noise is enhanced. be able to.
In the case of a microstrip line, as shown in FIG. 10, electric lines of force are densely concentrated between the wiring circuit 22 and the ground layer 20, and therefore, the conductive noise suppression body 1 is particularly preferably disposed between them. preferable.

  FIG. 11 shows how the loss power ratio at 1 GHz is affected by the distance from the microstrip line to the conduction noise suppression body. Specifically, a loss power ratio is obtained by measuring a S parameter by interposing a polyethylene terephthalate film between the microstrip line for conducting noise effect measurement and the conducting noise suppressor. According to this, as the separation distance increases, the loss power ratio decreases, and when the distance is 200 μm, it is about 30% smaller. Therefore, the separation distance is preferably smaller, more preferably 100 μm or less, more preferably 50 μm or less.

  FIG. 12 is a diagram illustrating an example of a multilayer printed board, which is another example of the electronic component with a conduction noise suppression body. This multilayer printed board is obtained by sequentially laminating a copper foil, a prepreg in which a reinforcing material such as a glass cloth is impregnated with a resin such as an epoxy resin (hereinafter simply referred to as a prepreg), and a conduction noise suppressing body 1. It was produced based on a multilayer substrate obtained by curing a resin.

  The multilayer substrate includes a wiring circuit obtained by patterning copper foil, a ground layer made of copper foil, a power supply layer made of copper foil, an insulating layer formed by curing a prepreg, and a conduction noise suppressing body 1. Is done. The layer configuration of the multilayer substrate is, in order from the top, wiring circuit 40, insulating layer 41, conduction noise suppressor 1, insulating layer 42, ground layer 43, insulating layer 44, conduction noise suppressor 1, insulating layer 45, and power supply layer 46. , Insulating layer 47, conductive noise suppressor 1, insulating layer 48, ground layer 49, insulating layer 50, conductive noise suppressor 1, insulating layer 51, power supply layer 52, insulating layer 53, and wiring circuit 54.

The multilayer printed board has a multilayer substrate and an electronic element 55 mounted thereon, and is generally configured. The electronic element 55 is connected to the wiring circuit 40, further connected to the power supply layer 46 via the via hole 56, and connected to the power supply layer 52 via the via hole 57.
In the multilayer printed board, the copper foil constituting the power supply layer and the ground layer spreads over almost the entire surface of the multilayer printed board, and these copper foils have a parallel plate structure with open peripheral edges, so that the power supply layer and the ground layer A large radiation noise is generated due to resonance between the two (power supply-ground layer resonance). Therefore, by disposing the conduction noise suppression body 1 not only in the vicinity of the wiring circuit but also between the power supply layer and the ground layer, power supply-ground layer resonance can be suppressed, and as a result, radiation noise due to this resonance can be suppressed. .

  Moreover, when producing a multilayer substrate, you may use the conduction noise suppression body with copper foil. The conductive noise suppressor with copper foil is a prepreg lined with copper foil as an insulating substrate, and a metal soft magnetic material is physically vapor-deposited on the resin surface of the prepreg to form a plurality of independent metal soft materials. A composite layer (conductive noise suppression layer) having a magnetic material cluster is formed, and a resin of the prepreg is cured. By alternately laminating conductive noise suppression bodies with copper foil and simple prepregs, wiring circuits, insulating layers, conductive noise suppression layers, insulating layers, ground layers, insulating layers, conductive noise suppression layers are arranged in order from the top. , Insulating layers, power supply layers, insulating layers, conductive noise suppression layers, insulating layers, ground layers, insulating layers, conductive noise suppression layers, insulating layers, power supply layers, insulating layers, and multilayer circuits having a wiring circuit configuration can be manufactured. .

  By using a conductive noise suppressor with copper foil, the number of stacked layers can be reduced, that is, the labor of the stacking operation can be reduced compared to the case where copper foil, prepreg, and conductive noise suppressor are prepared separately. . Further, since the prepreg is an insulating base in the conductive noise suppressor with copper foil, the thickness of the multilayer substrate is equivalent to the insulating base 2 of the conductive noise suppressor 1 compared to the multilayer substrate shown in FIG. Can be reduced. Further, in the multilayer substrate shown in FIG. 12, since the insulating base 2 of the conductive noise suppression body 1 is present, the composite layer 5 (conductive noise suppression layer) is equivalent to the thickness of the insulating base 2 by the power supply layer or ground. The conductive noise suppression layer can be disposed approximately in the middle between the power supply layer and the ground layer by using a conductive noise suppression body with a copper foil.

Examples are shown below.
(Evaluation)
Surface observation:
Using a field emission scanning electron microscope manufactured by JEOL Ltd., the surface of the conduction noise suppression body was observed at a magnification of 200,000 times under the conditions of an acceleration voltage of 3 kV and a working distance of 3 mm.
Cross-sectional observation:
A transmission electron microscope H9000NAR manufactured by Hitachi, Ltd. was used.
Shear modulus:
The shear modulus was measured using a solid analyzer RSA-II manufactured by Rheometric Scientific as a viscoelastic modulus measuring apparatus in a shear mode under a measurement frequency of 1 Hz.
Conductive noise suppression effect:
S11 (reflection attenuation amount) and S21 (transmission attenuation amount) by the S-parameter method were measured using a near-field electromagnetic wave absorption material measuring device manufactured by Keycom Corporation. Moreover, the loss power ratio was evaluated. As a network analyzer, a vector network analyzer 37247C manufactured by Anritsu Co., Ltd. was used. As a test fixture for a microstrip line having an impedance of 50Ω, TF-3A manufactured by Keycom Co., Ltd. was used.

( Reference Example 1)
As an insulating substrate, quartz glass having a thickness of 500 μm was prepared. On the upper surface of the quartz glass, Ni metal having a thickness of 10 nm is physically vapor-deposited by a facing target type magnetron sputtering method to form a metal soft magnetic material layer composed of a plurality of independent metal soft magnetic material clusters. A noise suppressor was obtained. At this time, the substrate temperature was kept at 50 ° C., and the bias voltage was adjusted so that the evaporated particles had a particle energy of 100 eV. The surface of the obtained conduction noise suppression body was observed with a field emission scanning electron microscope. The surface observation results are shown in FIG. Further, a part of the obtained conduction noise suppression body was made into a thin piece, an ion beam polisher was applied to the cross section, and the cross section of the metal soft magnetic layer was observed with a high resolution transmission electron microscope. The cross-sectional observation result is shown in FIG. Further, electron diffraction was performed on the metal soft magnetic layer, and the crystal state was observed. An electron diffraction image is shown in FIG.
High-resolution transmission electron microscope observation and electron diffraction show that nanometer-level Ni lattices are partially observed, but no clear grain boundaries are observed, and the metal soft magnetic clusters are dispersed independently. It was broken. Using the apparatus shown in FIG. 9, this conductive noise suppressor was placed in close contact with the 50 mm □ conductive noise suppressor so as to be parallel to the width direction of the microstrip line 12, and the S parameter was measured. The results are shown in FIG. Further, the loss power ratio at 1 GHz was determined to be 0.62. Next, after the conduction noise suppression body was heated at 150 ° C. for 240 hours, the loss power ratio was obtained in the same manner, and although it varied by about 13% from the initial value, it was a good value (0.54) and sufficient conduction was achieved. The noise suppression effect was shown.

(Example 1 )
On the quartz glass used in Reference Example 1, a 10 μm-thick polyacrylonitrile film (room temperature (25 ° C.) shear modulus 1.7 × 10 ⁹ (Pa), 160 ° C. shear modulus 1.5 × 10 ⁶ ( Pa), carbon dioxide gas permeability at room temperature (25 ° C.) 5.3 × 10 ⁻⁸ {cm ³ (STP) cm / (cm ² × sec × cm Hg)}, oxygen gas permeability at room temperature (25 ° C.) 8 × 10 ⁻¹⁵ {cm ³ (STP) cm / (cm ² × sec × cmHg)} was formed by casting, and an Fe metal having a thickness of 30 nm on the polyacrylic sheet was opposed to the target magnetron sputtering. The conductive noise suppressor was obtained by physically vapor-depositing by the method to obtain a conductive noise suppressor, while maintaining the substrate temperature at 160 ° C. and adjusting the bias voltage so that the evaporated particles had a particle energy of 100 eV. Is The portion of the conduction noise suppressing body is sectioned, subjected to ion beam poly Shah in cross section, showing a high resolution transmission electron microscopic observation of the cross section of the composite layer. Section observation result in Fig.
The cross-sectional state of the composite layer was almost the same as in Reference Example 1. As in Reference Example 1, when the loss power ratio before and after heating at 100 ° C. for 1000 hours was obtained, the changes were small and stable at 0.58 and 0.56, respectively, and a high conduction noise suppression effect was maintained. Was.

(Example 2 )
Except that the polyacrylonitrile film was changed to an epoxy resin, the same insulating substrate as in Example 1 was used, and an Fe—Ni soft magnetic metal having a thickness of 40 nm was formed on the insulating substrate by a counter target type magnetron sputtering method. Physical vapor deposition was performed to form a composite layer, and a conduction noise suppression body was obtained. At this time, the substrate temperature was kept at room temperature, a slight negative voltage was applied so that the evaporated particles had a particle energy of 8 eV, and at the same time, 50 sccm of nitrogen gas was introduced. After the sputtering was completed, the sample was heated to 250 ° C. at a rate of 1 ° C. per minute to cure the epoxy resin.
As in Reference Example 1, when the loss power ratio before and after heating at 150 ° C. for 240 hours was determined, it was unchanged from 0.64 and 0.63, and had sufficient heat resistance and high conduction noise suppression effect. .

( Reference Example 2 )
A conductive noise suppressor was obtained in the same manner as in Reference Example 1 except that the insulating substrate was changed to an alumina plate having a thickness of 500 μm (surface roughness Ra = 0.7 μm).
Similar to Reference Example 1, when the loss power ratio before and after heating at 150 ° C. for 240 hours was obtained, it varied by 7% from the initial stage, but it was a good value (0.55), and a sufficient conduction noise suppression effect was obtained. Indicated.

(Comparative Example 1)
On the same quartz glass as in Reference Example 1, co-sputtered Fe as a metal soft magnetic material by high frequency sputtering and alumina as a matrix material, and a magnetic film having a thickness of 2 μm having a composition of Fe ₇₂ Al ₁₁ O ₁₇ by fluorescent X-ray analysis Formed. Subsequently, in order to precipitate Fe fine particles, heat treatment was performed in vacuum at 300 ° C. for 2 hours to obtain a magnetic film having a granular structure.
As in Reference Example 1, the loss power ratio before and after heating at 150 ° C. for 240 hours was found to be 0.24 and 0.23, but there was no sufficient conduction noise suppression effect.

(Comparative Example 2)
The conductive noise suppression body of 50 mm □ obtained in Example 2 is arranged so as to be perpendicular to the width direction of the microstrip line 12 of the apparatus of FIG. 9, that is, is conducted on the test fixture 11 of FIG. The noise suppression body 1 was erected and arranged so as to be parallel to the lines of electric force from the microstrip line 12, and the loss power ratio was determined to be as low as 0.09, and there was no effect of suppressing conduction noise. .

  The conduction noise suppression body of the present invention has high suppression efficiency per volume, is stable, and can be provided in an electronic component by a simple method, so that the utility value is high, and the conduction noise suppression body is provided in a compact manner. In an electronic device having an electronic component, conduction noise and radiation noise are suppressed. As described above, it is possible to take high-quality EMC countermeasures for electronic devices while maintaining high performance, miniaturization, and weight reduction of the electronic devices.

It is an upper surface schematic diagram which shows an example of the conduction noise suppression body of this invention. It is a cross-sectional perspective schematic diagram of the conduction noise suppression body of FIG. It is an upper surface schematic diagram which shows the other example of the conduction noise suppression body of this invention. It is a field emission scanning electron microscope image of the surface of a metal soft-magnetic-material layer. 2 is a high-resolution transmission electron microscope image of a cross section of a metal soft magnetic layer. 2 is an electron diffraction image of a metal soft magnetic layer. It is a high-resolution transmission electron microscope cross-sectional image of the cross section of a composite layer. It is a schematic diagram which shows the cross section of a composite layer. It is a schematic block diagram which shows an example of the measuring apparatus of a conduction noise suppression effect. It is a schematic sectional drawing which shows an example of the electronic component with a conduction noise suppression body, and is a schematic diagram which shows an electromagnetic force line. It is a graph which shows how the loss power ratio in 1 GHz is influenced by the distance from a microstrip line to a conduction noise suppression body. It is a schematic sectional drawing which shows the other example (multilayer printed board) of an electronic component with a conduction noise suppression body. It is a graph which shows S11 (reflection attenuation amount) and S21 (transmission attenuation amount) of the conduction noise suppression body of Example 1.

Explanation of symbols

1 Conductive Noise Suppressor 2 Insulating Base 3 Metal Soft Magnetic Material Cluster 4 Metal Soft Magnetic Material Layer 5 Composite Layer 6 Crystal Lattice (Metal Soft Magnetic Material Cluster)
22 Wiring circuit 40 Wiring circuit

Claims (6)

An insulating substrate having a shear modulus of 1 × 10 ⁴ to 1 × 10 ¹⁰ Pa during physical vapor deposition ;
And a conductive noise suppression layer having a plurality of independent metal soft magnetic material clusters formed by physically vapor-depositing a metal soft magnetic material on the insulating substrate.   The conductive noise suppression body according to claim 1, wherein the conductive noise suppression layer is a layer formed by simultaneously vapor-depositing a metal soft magnetic material and a material different from the metal soft magnetic material. The conduction noise suppression body according to any one of claims 1 and 2 , wherein the loss power ratio at 1 GHz of the conduction noise suppression body is 0.3 to 0.9. Wiring circuit,
Comprising the conduction noise suppressor according to any one of claims 1 to 3 ,
Conductive noise suppression is characterized in that the conductive noise suppression body is arranged so that the surface of the conductive noise suppression layer and the electric lines of force radiated from the wiring circuit electromagnetically coupled to the conductive noise suppression layer are substantially orthogonal to each other. Body electronic parts. 5. The electronic component with a conductive noise suppression body according to claim 4 , wherein the width of the conductive noise suppression layer is wider than a width of a wiring circuit electromagnetically coupled to the conductive noise suppression layer. And transmission noise suppressing layer, the distance between the printed circuit electromagnetically coupled with transmission noise suppressing layer, according to claim 4 or claim 5 transmission noise suppressing electronic part mounted body wherein it is 0.1 to 200 [mu] m.

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