JP4472453B2 - Ultra-compact power converter and magnetic device - Google Patents

Description

  The present invention relates to an ultra-compact power conversion device, and more particularly to a power conversion device in which a coil is integrally mounted to reduce the size and suppress electromagnetic noise.

  A small-sized power conversion device, for example, a DC-DC converter IC, can convert a DC power source such as a battery into a DC power source having a desired voltage level with almost no energy loss, and is driven by a battery. Widely used. In addition, a DVD recorder or the like is equipped with a large number of integrated circuits, and since these integrated circuits require various power supply levels, a small DC-DC converter is used. The conventional three-terminal regulator uses a resistance component to convert the voltage level, so it can be used for electronic devices that require energy saving due to energy loss due to the resistance component and a large amount of battery power consumption. Can not. On the other hand, the DC-DC converter converts the first DC power source into a second DC power source whose voltage level has been lowered or raised by intermittently supplying current from the DC power source through a switching operation. Therefore, there is almost no energy loss. However, in order to smooth the pulsating flow generated by the switching operation, a filter circuit including an inductance and a capacitor is provided on the output side.

  A conventional DC-DC converter includes, for example, a module formed by mounting a converter IC, an inductance, and a capacitor on a printed wiring board. The module having such a configuration cannot meet the demand for downsizing.

  As a DC-DC converter that meets the demand for miniaturization, a module has been proposed in which a coil pattern sandwiched between magnetic films is mounted on the upper surface of a silicon substrate of a converter IC and mounted on a multilayer ceramic capacitor. For example, as shown in Patent Document 1. In this example, a converter circuit is formed on a silicon substrate, and a magnetic film / coil conductor pattern for coil / magnetic film (or a ferrite substrate) is provided on the surface, which is mounted on a multilayer ceramic capacitor.

As another example, a coil pattern sandwiched between magnetic films is formed on the upper surface of the silicon substrate of the converter IC, mounted on a printed wiring board or lead frame, and entirely sealed with a sealing resin containing magnetic particles. It has been proposed to stop. For example, as shown in Patent Document 2.
JP 2002-23314 A JP 2001-284123 A

  A DC-DC converter requires a coil having a predetermined inductance and a capacitor having a predetermined capacitance at its output stage. In order to reduce the size of the converter module, it is conceivable to increase the switching frequency of the converter and reduce the coil size. This is because if the frequency is increased, even if the coil size is reduced and the inductance is reduced, the impedance component jωL can be set to a predetermined impedance level by the high frequency ω. In addition, by increasing the switching frequency, it is possible to cope with a sudden increase in the required power level.

  However, when the switching frequency is 1 MHz or more, electromagnetic waves are generated from the input / output terminals and the wirings connected thereto, leading to an increase in electromagnetic noise. Therefore, it is necessary to provide a DC-DC converter that can suppress electromagnetic wave noise as well as downsizing.

  Furthermore, for power conversion, it is necessary to supply a current of a predetermined level or more through the coil, but it is necessary to prevent the magnetic material of the coil from causing magnetic flux saturation with respect to such drive current. is there. In order to reduce the size of the coil, in Patent Documents 1 and 2 described above, a coil pattern is formed on the silicon substrate of the converter IC via a magnetic thin film. Therefore, the magnetic material may cause magnetic flux saturation with respect to a current exceeding a predetermined level, and conversely, the inductance component of the coil may be reduced. That is, the magnetic thin film cannot increase the allowable current of the coil.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a power conversion apparatus or magnetic device that is miniaturized by mounting a coil integrally on an integrated circuit board and suppresses electromagnetic noise.

  Another object of the present invention is to provide a power conversion device or magnetic device in which a coil is integrally mounted on an integrated circuit board to reduce the size and increase the allowable current of the coil.

  In order to achieve the above object, in the first aspect of the present invention, a coil conductor pattern is formed on a first surface of a first magnetic substrate made of a magnetic material such as ferrite, and the first magnetic substrate An integrated circuit board is mounted on the second surface and an input / output conductor pattern is provided, and the integrated circuit board and the coil conductor pattern are connected via a through hole of the first magnetic substrate, The second magnetic substrate is provided, and the integrated circuit substrate on the second surface side of the first magnetic substrate and a part of the input / output conductor pattern are sealed with a sealing material containing a magnetic material. The space between the coil conductor patterns between the first surface of the first magnetic substrate and the second magnetic substrate is filled with the sealing material.

  According to the first aspect, the first magnetic substrate having a predetermined thickness is used as a base, the coil conductor pattern is provided on the first surface, and the second magnetic substrate is overlaid on the second surface. An integrated circuit board is mounted, and between the integrated circuit board and the coil conductor pattern is sealed and filled with a sealing material containing a magnetic material. Therefore, the coil or integrated circuit board through which the high-frequency signal propagates and its wiring are confined by the magnetic substrate or the magnetic material-containing sealing material, and leakage of high-frequency noise to the outside can be suppressed. Further, since the coil conductor pattern is sandwiched between the first and second magnetic substrates and the space between the coil conductor patterns is filled with the magnetic material-containing sealing material, a closed magnetic circuit is formed around the coil conductor pattern. The magnetic flux saturation does not occur for a predetermined current, and the allowable current level can be increased. The laminated structure of the two magnetic substrates and the integrated circuit substrate can contribute to miniaturization of the module.

  In the first aspect described above, in a preferred embodiment, the first magnetic substrate is provided with a sealing hole that allows passage of the sealing material in addition to the connection through hole, The magnetic substrate is also formed with a filling hole that enables filling of the coil conductor pattern with the sealing material. By providing such a sealing hole and a filling hole, in the sealing process, the sealing of the integrated circuit substrate on the second surface of the first magnetic substrate with the magnetic material-containing sealing material, and the coil It has the merit that filling of the sealing material between the conductor patterns can be performed simultaneously.

  In the first aspect, in a preferred embodiment, the first and second magnetic substrates are substrates having a predetermined thickness formed by molding a magnetic material such as ferrite. As a result, a sufficient volume of the magnetic material is disposed around the coil conductive pattern, and the magnetic flux is effectively confined, and magnetic flux saturation does not occur for currents below the allowable current.

  In the first aspect described above, in a preferred embodiment, a cavity for housing the integrated circuit substrate is provided on the second surface side of the first magnetic substrate, and the cavity is filled with a magnetic material-containing sealing material. ing. An input / output conductor pattern connected to the integrated circuit board is provided from the bottom surface and the slope to the top surface of the cavity, and the input / output conductor pattern on the bottom surface and the slope is sealed with a sealing material and exposed input / output. Connection to the outside is made by the conductor pattern.

In order to achieve the above object, according to a second aspect of the present invention, in a magnetic device in which an integrated circuit board and an inductance element connected to an output end thereof are integrated into a module,
A first magnetic substrate;
A coil conductor pattern formed on the first surface of the first magnetic substrate;
A second magnetic substrate disposed on the first surface of the first magnetic substrate so as to sandwich the coil conductor pattern;
An integrated circuit board mounted on the second surface of the first magnetic substrate and connected to the coil conductor pattern via a through-hole of the first magnetic substrate;
An input / output conductor pattern of the integrated circuit substrate formed on the second surface of the first magnetic substrate;
On the second surface of the first magnetic substrate, the integrated circuit substrate is sealed with a sealing material containing a magnetic material, and a gap between the coil conductor patterns between the first and second magnetic substrates is further provided. It is filled with the sealing material.

In order to achieve the above object, according to a third aspect of the present invention, in a method of manufacturing a magnetic device in which an integrated circuit board and an inductance element connected to an output end thereof are integrated into a module,
A coil conductor pattern is formed on the first surface, an input / output conductor pattern is formed on the second surface, a through hole connecting the coil conductor pattern and the input / output conductor pattern, and a seal Mounting an integrated circuit substrate on the second surface of the first magnetic substrate having a sealing hole through which a stopper can pass;
A sealing containing a magnetic material in a state where a second magnetic substrate having a filling hole through which a sealing material can pass is overlaid on the first surface of the first magnetic substrate and the coil conductor pattern. The integrated circuit board on the second surface of the first magnetic substrate and a part of the input / output conductor pattern are sealed with a stopper, and the sealing material is filled between the coil conductor patterns. And a sealing step.

  According to an aspect of the present invention, an integrated circuit board that may generate high-frequency noise, its input / output conductor pattern, and a coil conductor pattern are all formed on a magnetic board, formed between the magnetic boards, and a magnetic material. Since it is coat | covered with the containing sealing material, it is suppressed that a high frequency noise leaks outside.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the technical scope of the present invention is not limited to these embodiments, but extends to the matters described in the claims and equivalents thereof.

  FIG. 1 is a configuration diagram of a DC-DC converter that is an example of the power conversion apparatus according to the present embodiment. FIG. 1 shows two types of DC-DC converters. FIG. 1A shows a step-down DC-DC converter circuit, and a DC-DC converter module 20 is constituted by a DC-DC converter IC (integrated circuit device) 10 and a coil L connected to its output terminal. The A smoothing capacitor C is connected to the output Vout of the module 20. The DC-DC converter IC 10 includes a switching circuit including CMOS transistors P1 and N1 therein, and steps down the first DC power supply VDD to generate a second DC power supply as an output Vout. The transistors P1 and N1 intermittently supply current to the coil L, the pulsating flow of the alternating current at the output terminal Lx is smoothed by the filter characteristics of the coil L and the capacitor C, and a DC voltage is generated at the output Vout. . The DC-DC converter IC 10 includes a power supply terminal VDD, a ground terminal G, a control terminal CNT, a reference voltage terminal VREF, and a feedback terminal OUT.

  FIG. 1B shows a step-up DC-DC converter. Similarly, a DC-DC converter module including a DC-DC converter IC (integrated circuit device) 10 and a coil L connected to an external terminal 12 thereof. 20 is configured. This DC-DC converter IC 10 also has CMOS transistors P3 and N4 therein, and alternately supplies current to the coil L, boosts the first DC power supply VDD, and supplies the second DC power supply to the output Vout. Generate. A smoothing capacitor C is connected to the output Vout.

  In any DC-DC converter, the alternating voltage generated by the switching operation of the DC-DC converter IC is smoothed by the filter composed of the coil L and the capacitor C to generate a DC voltage. Therefore, by increasing the switching frequency (f = 2πω), the impedance (jωL) of the coil L can be increased, and conversely, the inductance of the coil L can be reduced. The size can be reduced. Thus, since the size of the coil L can be reduced by increasing the switching frequency of the converter IC, increasing the switching frequency is effective for minimizing the DC-DC converter. In addition, by increasing the switching frequency, it is possible to flexibly cope with a sudden change in required power on the output side.

  However, as the switching frequency increases, high-frequency component signals propagate to the input / output terminals of the integrated circuit device 10 and the input / output terminals of the modules connected thereto, the coil L, the power supply terminals VDD, GND, and the like. Is sent out and becomes a noise source to peripheral devices. Such a problem of high-frequency noise is a problem caused by increasing the switching frequency in order to reduce the size of the coil, and is a new problem not found in the conventional DC-DC converter. Therefore, in order to reduce the size of a power converter such as a DC-DC converter, a structure capable of suppressing this high frequency noise is required.

  Further, when a current is supplied to the coil L, a magnetic flux is generated in the magnetic body around the coil conductive pattern. A magnetic saturation phenomenon is known in which when the current is increased, the generated magnetic flux is also increased. When the volume of the magnetic material is small, magnetic flux saturation occurs, and when the current is further increased, the inductance decreases and becomes zero. Therefore, in order to substantially function as an inductance element, it is desirable that the coil is configured such that magnetic flux saturation does not occur within the allowable current range.

[Structure of power converter]
FIG. 2 is a cross-sectional view and a plan view of the power conversion device according to the present embodiment. A cross-sectional view taken along the line AA ′ in the plan view of FIG. 2B is shown in FIG. The power conversion device according to the present embodiment is based on a magnetic substrate 1 made of a magnetic material such as ferrite, and a coil L and an integrated circuit substrate 8 are provided on the front side and the back side, respectively, and the whole contains a magnetic material. It seals with the resin sealing agent 22 to do. On the magnetic substrate 1, a spiral coil conductor pattern L is formed on the upper first surface. On the other hand, an input / output conductor pattern I / O connected to the input / output terminals of the integrated circuit substrate 8 and the back surface of the substrate is formed on the second lower surface of the magnetic substrate 1, and a part of the input / output pattern is formed. The pattern 32 is connected to one end of the coil conductor pattern L on the first surface by a through hole 24 provided in the center of the magnetic substrate 1. The coil conductor pattern L and the input / output conductor pattern I / O are laminated on the insulating film 2 such as a silicon oxide film or a tantalum oxide film formed on the surface of the magnetic substrate 1 by a plating process described later. It consists of a plating underlayer 3, a Cu plating layer 4, and a Ni / Sn layer 5 for soldering. The laminated structure of the through hole 24 is the same.

  A second magnetic substrate 7 is provided on the first surface of the magnetic substrate 1, and the coil conductor pattern L is sandwiched between the first magnetic substrate 1 and the second magnetic substrate 7.

  Further, a cavity for housing the integrated circuit substrate 8 is formed on the second surface of the magnetic substrate 1, and an input / output conductor pattern I / O is formed extending from the bottom surface 1a of the cavity to the inclined surface 1b and the top surface 1c. Has been. Then, the input / output conductor pattern I / O on the integrated circuit board 8 in the cavity, the bottom surface 1a, and the inclined surface 1b is sealed with a resin sealant 22 containing a magnetic material, and the input / output conductor on the upper surface 1c. Only the pattern is exposed to the outside. The same resin sealant 22 is filled between the first and second magnetic substrates 1 and 7 and between the coil conductor patterns L. In order to simplify the sealing process using the resin sealant 22, a sealing hole through which the sealant can pass is formed in the first magnetic substrate 1, and the second magnetic substrate 7 is sealed. A filling hole 28 through which the stopper can pass is formed. Using these sealing holes and filling holes 28, the sealing of the integrated circuit board 8 and the filling between the coil conductor patterns L are performed by a sealing process of supplying a resin sealing agent from the top to the bottom. And done. This step will be described in detail later.

  The power converter module described above is, for example, 3.5 mm square, the thickness of the first magnetic substrate 1 is 0.7 mm, the depth of the cavity is 0.4 mm, and the diameter of the through hole is about 0.3 mm. Therefore, it is possible to provide a power converter that is very downsized. The first surface (upper surface) of the first magnetic substrate 1 is provided with a second magnetic substrate 7, and a magnetic material is applied to the second surface (lower surface side) of the first magnetic substrate 1. The sealing agent 22 to be contained is provided, and only the input / output conductor pattern for connection with the outside is exposed to the outside. Therefore, the entire circuit is effectively shielded magnetically, and high frequency noise is effectively prevented from leaking to the outside, and is also protected from high frequency noise from the outside. The coil conductor pattern L through which the high-frequency signal propagates is completely surrounded by the first and second magnetic substrates 1 and 7 and the magnetic material-containing sealant 22 filled therebetween to form a closed magnetic circuit, and the magnetic flux is It is effectively enclosed inside. Similarly, the input / output conductor pattern I / O is completely surrounded by the first magnetic substrate 1 and the magnetic material-containing sealing agent 22 to form a closed magnetic circuit, and the magnetic flux is effectively confined inside. . Therefore, high frequency noise is prevented from leaking outside.

  The first and second magnetic substrates 1 and 7 are relatively thick magnetic substrates formed by molding and firing a magnetic material such as ferrite, and a sufficient volume of the magnetic material is formed on the coil conductor pattern L. The sealing material 22 containing magnetic material is filled between the coil conductor patterns L. Therefore, the inductance element has a magnetic body sufficient to generate a sufficient magnetic flux, and magnetic flux saturation is prevented from occurring within the allowable current range.

  Thus, since the power conversion device module has a configuration in which the coil pattern and the integrated circuit substrate are stacked and sealed based on the first magnetic substrate 1, the size can be reduced very effectively. And mechanical strength is sufficient. In addition, leakage of high-frequency components to the outside is suppressed, and magnetic flux saturation can be avoided. Hereafter, the manufacturing process of said module is demonstrated.

[Manufacturing process of power converter]
FIG. 3 is a diagram illustrating the manufacture of the first magnetic substrate. FIG. 3 shows a perspective view of the first magnetic substrate 1 and its AA ′ cross-sectional view. The magnetic substrate 1 is formed by compacting and firing any powder of NiZn ferrite, MnZn ferrite, and Sendust ferrite. Alternatively, the magnetic substrate 1 is formed by pattern-molding a substrate compacted and fired into a plate having a predetermined thickness by a sandblast method. In the example of FIG. 3, a 3 × 3 power conversion module substrate is simultaneously formed in a relatively large substrate. As is clear from the perspective view, a cavity CV having a depth of about 0.4 mm is formed in the magnetic substrate 1, and the thickness of the magnetic substrate 1 is, for example, 0.7 mm. The slope of the cavity CV has an inclination of about 20 degrees, for example. Further, a through hole 24 is formed on the bottom surface of the cavity CV, and a sealing hole 26 through which a sealing agent can pass and another through hole (not shown) are formed at four corners of the cavity CV. . The sectional view shows the cavity CV and the through hole 24, and the through hole is chamfered. Such a first magnetic substrate 1 is cut at a position indicated by a broken line at the end of a manufacturing process described later, and is divided into nine modules in total.

  FIG. 4 is a cross-sectional view showing a manufacturing process of the power conversion device according to the present embodiment. Hereinafter, it demonstrates in order. FIG. 4A is a cross-sectional view of FIG. 3 turned upside down. In the first magnetic substrate 1 made of a ferrite material, a cavity CV and a through hole 24 are formed. For smoothing the surface of the substrate and for insulation when the substrate 1 has conductivity, silicon oxide or An insulating film 2 such as tantalum oxide is formed to a thickness of 0.5 to 1.0 μm by sputtering. When the magnetic substrate 1 is made of a highly insulating NiZn ferrite, the formation of the insulating layer 2 can be omitted.

  In FIG. 4B, a Ti / Cr / Cu metal layer 3 is formed on the surface of the magnetic substrate 1 by a sputtering method as a seed layer for a plating process described later. The Ti / Cr film is formed with a thickness of about 500 to 1000 mm as a base film for the purpose of improving the adhesion of Cu, and the Cu film is formed with a thickness of about 0.5 to several μm. The metal layer 3 is formed on both surfaces of the first magnetic substrate 1, in the through hole 24, and on the bottom surface 1a, slope 1b, and top surface 1c of the cavity CV.

  Next, in FIG. 4C, a photoresist RS is applied to both surfaces of the first magnetic substrate 1 by spray coating or spin coating, dried at a predetermined temperature, and then patterned by a photolithography process to obtain a coil conductor pattern. The photoresist in the region where the input / output conductor pattern is formed and the region of the through hole 24 is removed to partially expose the metal layer 3.

Next, in FIG. 4D, a desired thickness of Cu conductor layer 4 is deposited on the exposed metal layer 3 by electrolytic plating. As a coil conductor pattern formed on the first surface (upper surface) of the magnetic substrate 1, the Cu conductor layer 4 is deposited to a thickness of about 30 to 100 μm. Further, a Ni / Sn layer 5 for soldering is deposited on the Cu conductor layer 4 by subsequent electrolytic plating. The thickness is about 0.5 μm for Ni and about several μm for Sn. A flip chip having a solder ball on the surface is connected face-down to the Ni / Sn layer 5. Further, instead of the Ni / Sn plating layer 5, a Ni / Au plating layer may be provided on the bottom surface 1a of the cavity. In that case, the integrated circuit board is bonded not by soldering but by a conductive adhesive described later. And it connects by wire bonding.
In this step, it is necessary to prevent the hole of the through hole 24 from being blocked by the plating layer, and the size of the through hole 24 of the magnetic substrate 1 and the film of the plating layer are ensured so that a hole of at least 100 μm is secured. Decide the thickness.

  In FIG. 4E, the photoresist RS is removed, and the exposed plating base film 3 is removed by a chemical etching method or a back sputtering method, and input / output on the coil conductor pattern L, the bottom surface 1a of the cavity, and the inclined surface 1b. The conductor pattern I / O, the pattern of the through hole 24, and the input / output terminal conductor pattern on the upper surface 1c of the cavity CV are electrically separated.

  Finally, in FIG. 4F, an insulating film 6 such as a silicon oxide film is partially formed by sputtering on the conductor pattern of the through hole 24 on the bottom surface 1a of the cavity. This insulating film 6 is formed to ensure insulation between the conductor pattern of the through hole 24 and the integrated circuit substrate (silicon substrate) to be mounted.

  As described above, the coil conductor pattern L is formed on the first surface of the first magnetic substrate 1, and the input / output conductor pattern I / O is formed in the cavity CV of the second surface. In 24, a pattern for connecting the coil conductor pattern L and the input / output conductor pattern I / O is formed.

  FIG. 5 is a diagram showing conductor patterns on the first surface and the second surface of the first magnetic substrate 1 after the step of FIG. 4 is completed. 5A shows the second surface (lower surface) of FIG. 4, and FIG. 5B shows the first surface (upper surface) of FIG. On the second surface of FIG. 5A, a mounting conductor pattern 30 on which the integrated circuit board is mounted and a conductor pattern 32 connected to the through hole 24 are formed on the bottom surface of the cavity. The insulating film 6 is covered. An input / output conductor pattern I / O is formed along the bottom surface 1a, the slope 1b, and the top surface 1c of the cavity CV. In the four corners of the cavity CV, another through hole 25 and three sealing holes 26 are formed. A spiral coil conductor pattern L is formed between the through holes 24 and 25 on the first surface of FIG. Three sealing holes 26 are also formed.

  As is apparent from FIGS. 4F and 5, the conductor pattern 32 is connected to one end of the coil conductor pattern L via the through hole 24, and the other end of the coil conductor pattern L is output via the through hole 25. Connected to terminal Vout.

  FIG. 6 is a cross-sectional view showing a manufacturing process in the present embodiment. FIG. 6 shows an AA ′ sectional view and a BB ′ sectional view of FIG. 3. The through-hole 25 and the sealing hole 26 are clearly shown in the BB ′ sectional view. Then, an integrated circuit substrate 8 having a DC-DC converter circuit is bonded by a conductive adhesive 9 on the mounting conductor pattern 30 in the cavity CV of the first magnetic substrate 1. Alternatively, it may be soldered. At this time, the surplus of the conductive adhesive 9 and the solder is absorbed into the through hole 24 and good bonding is performed. Further, the integrated circuit board 8 and the input / output conductor pattern I / O and the conductor pattern 32 are connected by the conductive wire W.

  FIG. 7 is a cross-sectional view showing a sealing process in the present embodiment. FIG. 7 shows a sealed state of the BB ′ sectional view of FIG. In the sealing step, the second magnetic substrate 7 is overlaid on the coil conductor pattern L of the first magnetic substrate 1 with the integrated circuit substrate 8 of FIG. Deploy. At the center of the second magnetic substrate 7, an air vent hole 7a of about 0.3 mm for injecting the sealing agent 22 is provided. Then, a sealant 22 containing a magnetic material is injected in the direction of the arrow 42 to seal the integrated circuit substrate 8 in the cavity with the sealant. Further, the sealant 22 is caused to wrap around the opposite side of the first magnetic substrate 1 through the through hole 25 and the sealing through hole 26 formed in the first magnetic substrate 1, so that the first magnetic substrate 1 A sealant 22 containing a magnetic material is also filled between the coil conductor patterns L between the first magnetic substrate 7 and the second magnetic substrate 7. The sealant is, for example, an epoxy resin mixed with NiZn-based ferrite powder, and the epoxy resin is cured at about 150 ° C. By this sealing step, the second magnetic substrate 7 is integrated with the first magnetic substrate 1. Therefore, the sealing through hole 26 needs to be formed in a size and a position where the sealing agent 22 can be effectively wrapped around.

  FIG. 8 is a cross-sectional view of the power conversion module after being separated. The direction of the cross-sectional view is the same as in FIG. At the end of the manufacturing process, the wafer is cut by a dicing saw or laser along the one-dot chain line shown in FIG. 3 and separated into individual power conversion modules. In the power conversion module, the integrated circuit board 8 of the DC-DC converter is mounted in the cavity of the second surface (upper surface) of the first magnetic substrate 1, and the first surface (lower surface) of the first magnetic substrate 2 is mounted. Is formed with a coil conductor pattern L, and the coil conductor pattern L is sandwiched between the first and second magnetic substrates 1 and 7. The coil conductor pattern L and the integrated circuit board 8 are connected via a through-hole conductor pattern, and the integrated circuit board 8 and the input / output conductor pattern I / O are magnetic on the first magnetic substrate 1. It is sealed with the material-containing sealant 22, and the magnetic material-containing sealant 22 is also filled between the coil conductor patterns L.

  As described above, based on the first magnetic substrate 1, the integrated circuit substrate 8 and the coil conductor pattern L are provided by using both surfaces thereof, and these are provided with the magnetic material-containing sealing agent 22 and the second magnetic substrate. 7, the structure is small and robust, and leakage of high-frequency components can be suppressed. That is, all the propagation paths through which high-frequency components propagate are confined with magnetic materials except for the input / output terminal portions for connection.

[Modification of Embodiment]
FIG. 9 is a diagram illustrating a first modification of the present embodiment. In this modified example 1, without providing a cavity in the first magnetic substrate 1, an input / output terminal magnetic substrate having an input / output terminal conductor pattern formed on the surface on which the integrated circuit substrate is mounted is provided. An integrated circuit board is mounted in a cavity surrounded by a magnetic substrate for use. Other configurations are the same as those of the embodiment of FIGS.

  FIG. 9A is a cross-sectional view of the state in which the conductor patterns L, 30 and I / O are formed on both surfaces of the first magnetic substrate 1. This cross-sectional view corresponds to the state of FIG. 4F, and the first magnetic substrate 1 is flat without a cavity. FIG. 9B is a cross-sectional view and a plan view of the magnetic substrate 44 for input / output terminals. As shown in the cross-sectional view, four through holes 46 are formed in the substrate 44, and input / output terminal conductor patterns IOT that connect both surfaces of the substrate 44 are formed in the through holes. The film structure of this conductor pattern is the same as that of the conductor pattern formed on the first magnetic substrate 1. FIG. 9C shows a cross-sectional view of the power conversion module in the first modification. The magnetic substrate 44 for input / output terminals shown in FIG. 9B is bonded to the surface on which the integrated circuit substrate 8 of the first magnetic substrate 1 is mounted by the conductive adhesive 9 or by soldering. . As a result, the input / output terminal magnetic substrate 44 forms a cavity on the lower surface of the first magnetic substrate 1. Then, the integrated circuit board 8 is mounted in the cavity and sealed with the magnetic material-containing sealant 22. As shown in FIG. 2B, the input / output terminal magnetic substrate 44 includes two substrates having four input / output terminal conductor patterns IOT and two substrates having input / output terminal conductor patterns IOT. A cavity can be formed by adhering two to the periphery of the first magnetic substrate 1.

  Further, on the upper surface side of the first magnetic substrate 1, the second magnetic substrate 7 is placed on the coil conductor pattern L and integrated by the sealant 22. Between the coil conductor patterns L, the magnetic material-containing sealant 22 is filled. The sealing process is the same as the method shown in FIG.

  In the configuration of the first modification, the input / output terminal conductor pattern I / O and the input / output terminal conductor pattern IOT are connected by the through hole of the input / output terminal magnetic substrate 44. Therefore, all the wirings through which the high frequency component propagates are formed on or in the magnetic substrate and are further confined by the magnetic material-containing sealing agent 22, so that high frequency noise is prevented from leaking to the outside. Further, in the processing step of the first magnetic substrate 1, it is not necessary to form a cavity, and only a hole for a through hole is formed.

  FIG. 10 is a diagram illustrating a second modification of the present embodiment. In the second modification, instead of the input / output terminal magnetic substrate 44 of the first modification, a Cu ball electrode 50 whose surface is processed by Ni / Sn plating or the like is soldered or conductive on the input / output conductor pattern I / O. It adheres with the adhesive 9. Other than that is the same as the first modification.

  FIG. 11 is a diagram illustrating a third modification of the present embodiment. In the modified example 3, as in the modified example of FIG. 9, the first magnetic substrate 1 is not provided with a cavity, but the input / output terminal substrate 44 is formed on the input / output conductor pattern I / O. A configuration in which a power input terminal Vin or a power output terminal Vout and a ground terminal GND are provided adjacent to each other, and a multilayer ceramic chip capacitor C1, C2, C3 having a predetermined size is bonded by a conductive adhesive 9 between these terminals. Have.

  FIG. 11A is a plan view on the input / output terminal side, and FIG. 11B is a cross-sectional view taken along line DD ′ in the plan view. One end of the electrodes of the chip capacitors C2 and C3 is adhered to the input / output conductive pattern I / O formed on the first magnetic substrate 1 by the conductive adhesive 9, and the electrodes of the chip capacitors C2 and C3 are connected. The other end is a connection terminal with the outside. An input / output terminal substrate 44 is provided at an input / output terminal that does not require a chip capacitor. As shown in the cross-sectional view, the height of the input / output terminal substrate 44 and the height of the chip capacitors C1, C2, and C3 are made equal, and the height of the connection terminals with the outside is made the same level. Then, the integrated circuit board (not shown), the chip capacitors C1, C2, and C3 and the input / output terminal board 44 are sealed by the magnetic material-containing sealing material 22 except for the connection area to the outside. The

  In Modification 3, since the chip capacitors are provided at the power input terminal Vin and the power output terminal Vout through which the high frequency component propagates instead of the input / output terminal substrate 44, the high frequency noise of the power supply can be removed. The other input / output terminals are configured to confine high-frequency noise by the configuration in which the conductive pattern IOT for input / output terminals is formed on the magnetic substrate and the configuration of sealing with the magnetic material-containing sealing material 22, and leakage of high-frequency noise. Can be suppressed.

  In the above embodiment, the power conversion device on which the integrated circuit board of the DC-DC converter is mounted has been described as an example. However, the same module configuration can be applied to a magnetic device on which an integrated circuit board is mounted and an inductance element is connected thereto. Also in this case, high frequency noise can be suppressed, and magnetic flux saturation of the magnetic material layer surrounding the inductance element can be prevented.

  The above embodiment is summarized as follows.

(Additional remark 1) In the power converter device which modularized the integrated circuit board which performs switching operation, and the inductance element connected to the output terminal,
A first magnetic substrate;
A coil conductor pattern formed on the first surface of the first magnetic substrate;
A second magnetic substrate disposed on the first surface of the first magnetic substrate so as to sandwich the coil conductor pattern;
An integrated circuit board mounted on the second surface of the first magnetic substrate and connected to the coil conductor pattern via a through-hole of the first magnetic substrate;
An input / output conductor pattern of the integrated circuit substrate formed on the second surface of the first magnetic substrate;
On the second surface of the first magnetic substrate, the integrated circuit substrate is sealed with a sealing material containing a magnetic material, and a gap between the coil conductor patterns between the first and second magnetic substrates is further provided. A power conversion device filled with the sealing material.

(Appendix 2) In Appendix 1,
The power conversion device according to claim 1, wherein a sealing hole that allows the sealing material to pass through is formed in the first magnetic substrate.

(Appendix 3) In Appendix 1 or 2,
The power conversion device according to claim 1, wherein a filling hole is formed in the second magnetic substrate so that the coil conductor pattern can be filled with a sealing material.

(Appendix 4) In Appendix 1,
The first and second magnetic substrates are substrates having a predetermined thickness obtained by molding and baking a magnetic material.

(Appendix 5) In Appendix 1,
A cavity for housing the integrated circuit board is provided on the second surface side of the first magnetic substrate, the cavity is filled with a magnetic material-containing sealing material, and the integrated circuit board is sealed, and the cavity An input / output conductor pattern connected to the integrated circuit board is provided from the bottom surface and the slope to the top surface, and the input / output conductor pattern on the bottom surface and the slope is sealed with the sealing material and exposed to the top surface. A power conversion device characterized in that connection to the outside is performed by an output conductor pattern.

(Appendix 6) In Appendix 1,
An input / output terminal member made of a third magnetic substrate connected to the input / output conductor pattern and having a through hole is provided on the second surface of the first magnetic substrate, and is surrounded by the input / output terminal member. The power converter is characterized in that the integrated circuit board is accommodated in the recessed portion and sealed with the sealing material.

(Appendix 7) In Appendix 6,
On the second surface of the first magnetic substrate, the power input / output conductive pattern is connected between the power input / output conductive pattern and the ground conductive pattern of the input / output conductor pattern, and the same height as the input / output terminal member is provided. A power conversion device comprising a capacitor member having a thickness.

(Appendix 8) In Appendix 1,
A power conversion device comprising a plurality of conductor ball terminals provided on the second surface of the first magnetic substrate and on the input / output conductor pattern.

(Appendix 9) In Appendix 1,
The integrated circuit board includes a switching circuit that is supplied with a first DC power source and intermittently supplies a current to one end side of the coil conductor pattern, and the first circuit is provided on the other end side of the coil conductor pattern. A power converter for generating a second DC power supply having a voltage level different from that of the DC power supply.

(Supplementary Note 10) In a magnetic device in which an integrated circuit board and an inductance element connected to an output end thereof are integrated into a module,
A first magnetic substrate;
A coil conductor pattern formed on the first surface of the first magnetic substrate;
A second magnetic substrate disposed on the first surface of the first magnetic substrate so as to sandwich the coil conductor pattern;
An integrated circuit board mounted on the second surface of the first magnetic substrate and connected to the coil conductor pattern via a through-hole of the first magnetic substrate;
An input / output conductor pattern of the integrated circuit substrate formed on the second surface of the first magnetic substrate;
On the second surface of the first magnetic substrate, the integrated circuit substrate is sealed with a sealing material containing a magnetic material, and a gap between the coil conductor patterns between the first and second magnetic substrates is further provided. A magnetic device filled with the sealing material.

(Additional remark 11) In the manufacturing method of the magnetic device which integrated the integrated circuit board and the inductance element connected to the output end into a module,
A coil conductor pattern is formed on the first surface, an input / output conductor pattern is formed on the second surface, a through hole connecting the coil conductor pattern and the input / output conductor pattern, and a seal Mounting an integrated circuit substrate on the second surface of the first magnetic substrate having a sealing hole through which a stopper can pass;
A sealing containing a magnetic material in a state where a second magnetic substrate having a filling hole through which a sealing material can pass is overlaid on the first surface of the first magnetic substrate and the coil conductor pattern. The integrated circuit board on the second surface of the first magnetic substrate and a part of the input / output conductor pattern are sealed with a stopper, and the sealing material is filled between the coil conductor patterns. A method for manufacturing a magnetic device, comprising: a sealing step.

(Appendix 12) In Appendix 11,
In the sealing step, the sealing material is supplied from the second surface side of the first magnetic substrate, and the sealing material is supplied to the second magnetic substrate via a sealing hole. A method of manufacturing a magnetic device, wherein the sealing material is supplied from a surface toward the first surface and supplied through a filling hole of the first magnetic substrate.

It is a block diagram of the DC-DC converter which is an example of the power converter device of this Embodiment. It is sectional drawing and the top view of the power converter device in this Embodiment. It is a figure which shows manufacture of a 1st magnetic substrate. It is sectional drawing which shows the manufacturing process of the power converter device in this Embodiment. It is a figure which shows the conductor pattern of the 1st surface and the 2nd surface of the 1st magnetic substrate 1 which finished the process of FIG. It is sectional drawing which shows the manufacturing process in this Embodiment. It is sectional drawing which shows the sealing process in this Embodiment. It is sectional drawing of the power conversion module after isolate | separating. It is a figure which shows the modification 1 of this Embodiment. It is a figure which shows the modification 2 of this Embodiment. It is a figure which shows the modification 3 of this Embodiment.

Explanation of symbols

1: 1st magnetic substrate, 7: 2nd magnetic substrate, 8: Integrated circuit board 22: Magnetic material containing sealing material, 24: Through hole, 25: Through hole 26: Hole for sealing, 28: For filling Hall L: Conductor pattern for coil, I / O: Conductor pattern for input / output

Claims (5)

In a power conversion device in which an integrated circuit board that performs a switching operation and an inductance element connected to an output end thereof are integrated into a module,
A first magnetic substrate;
A coil conductor pattern formed on the first surface of the first magnetic substrate;
A second magnetic substrate disposed on the first surface of the first magnetic substrate so as to sandwich the coil conductor pattern;
An integrated circuit substrate housed in a cavity provided on the second surface side of the first magnetic substrate, and connected to the coil conductor pattern via a through hole of the first magnetic substrate;
An input / output conductor pattern of the integrated circuit substrate formed on the second surface of the first magnetic substrate;
The cavity is filled with a magnetic material-containing sealing material to seal the integrated circuit board, and the space between the coil conductor patterns between the first and second magnetic boards is filled with the sealing material. A power converter characterized by comprising: In claim 1,
The power conversion device according to claim 1, wherein a sealing hole that allows the sealing material to pass through is formed in the first magnetic substrate. In claim 1 or 2,
The power conversion device according to claim 1, wherein a filling hole is formed in the second magnetic substrate so that the coil conductor pattern can be filled with a sealing material. In a magnetic device in which an integrated circuit board and an inductance element connected to its output end are integrated into a module,
A first magnetic substrate;
A coil conductor pattern formed on the first surface of the first magnetic substrate;
A second magnetic substrate disposed on the first surface of the first magnetic substrate so as to sandwich the coil conductor pattern;
An integrated circuit substrate housed in a cavity provided on the second surface side of the first magnetic substrate, and connected to the coil conductor pattern via a through hole of the first magnetic substrate;
An input / output conductor pattern of the integrated circuit substrate formed on the second surface of the first magnetic substrate;
The cavity is filled with a sealing material containing a magnetic material to seal the integrated circuit board, and an input / output conductor pattern connected to the integrated circuit board is provided from the bottom surface to the top surface of the cavity. The output conductor pattern is sealed with the sealing material, connected to the outside by the input / output conductor pattern exposed on the upper surface, and further, the coil conductor between the first and second magnetic substrates. A magnetic device characterized in that a space between patterns is filled with the sealing material. In a method of manufacturing a magnetic device in which an integrated circuit board and an inductance element connected to an output end thereof are integrated into a module,
A coil conductor pattern is formed on the first surface, a cavity is provided on the second surface side, an input / output conductor pattern is formed on the second surface from the bottom surface to the top surface of the cavity, and the coil In the cavity on the second surface of the first magnetic substrate having a through hole connecting the conductive pattern for input and the input / output conductive pattern and a sealing hole through which the sealing material can pass. Mounting the integrated circuit board; and
In a state where a second magnetic substrate having a filling hole through which a sealing material can pass is overlaid on the first surface of the first magnetic substrate and the conductor pattern for the coil , Input / output on the bottom surface excluding the integrated circuit substrate and the top surface in the cavity on the second surface of the first magnetic substrate by a sealant containing a magnetic material supplied through the filling hole And a sealing step of sealing the sealing material between the coil conductor patterns.

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