JP2011145273A - Current sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a small size inexpensive current sensor which can accurately detect a current to be measured by using a multilayer printed wiring board. <P>SOLUTION: A primary conductor pattern is formed by using a conductor layer pattern of at least one internal layer of the multilayer printed wiring board, and a magnetoelectric conversion element is also included. Consequently, a withstand voltage between the primary conductor pattern and the magnetoelectric conversion element is improved, and the multilayer printed wiring board can be reduced in comparison with the case where the primary conductor pattern and the magnetoelectric conversion element are exposed, and cost can be reduced, and the primary conductor pattern can be positioned close to the magnetoelectric conversion element, to thereby heighten accuracy. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a current sensor provided with a magnetoelectric conversion element and a primary conductor pattern in a multilayer printed wiring board.

  Conventionally, as a method for measuring a current to be measured in a non-contact manner, there is generally a method using a magnetic core. In a current sensor using a magnetic core, the magnetic core is installed so as to surround a conductor through which a current to be measured flows, and a magnetic circuit is formed together with a gap portion provided in the magnetic core. The magnitude of the current to be measured is measured in a non-contact manner by measuring the magnitude of the magnetic flux generated in the magnetic circuit by the current to be measured through the magnetoelectric conversion element installed in the gap portion.

  In recent years, a coreless type current sensor that does not use a magnetic core has been proposed for the purpose of miniaturization, weight reduction, high accuracy, and the like, particularly in large current measurement. As a coreless type current sensor, there is one in which a Hall element is installed on a metal U-shaped primary conductor via an insulating layer and a shield layer (see, for example, Patent Document 1).

  As another coreless type current sensor, a magnetoresistive element and a primary conductor are installed via a base, and the base side surrounds the magnetoresistive element by a conductor layer and the non-base side is surrounded by a metal case. There is a configuration having a shielding effect (see, for example, Patent Document 2).

  Furthermore, as another coreless type current sensor, a magnetoelectric conversion element is installed in the vicinity of the U-shaped portion of the U-shaped primary conductor bent in a crank shape, and further, the U-shaped primary conductor and the magnetoelectric conversion element There is one in which ferromagnetic materials are arranged substantially in parallel so as to sandwich both of them (see, for example, Patent Document 3).

  JP 2001-174486 A   JP-A-5-273321   Japanese Patent Laid-Open No. 5-223849

Problems to be solved by the invention

  The coreless type current sensor disclosed in Patent Document 1 has a configuration in which a shield layer is provided between the Hall element and the primary conductor, and electric field noise mainly generated from the primary conductor can be removed or reduced. However, strictly speaking, electric field noise is not applied only to the Hall element from the primary conductor side, and it is not configured to remove or reduce electric field noise from other directions except the primary conductor side around the Hall element. There was a problem that detection errors due to electric field noise from other directions occurred and it was not suitable for high accuracy.

  In the coreless type current sensor disclosed in Patent Document 2, the magnetoresistive element installed on the base surrounds the magnetoresistive element with a conductor layer on the base side and a metal case on the opposite base side. Thus, the shield layer is configured so that electric field noise not only from the primary conductor but also from all directions can be removed or reduced. However, there is a problem that the conductor layer has to be applied in a separate process on the uneven base, which is not suitable for cost reduction. In addition, a metal case as a separate member is necessary, and there is a problem that it is not suitable for cost reduction. Furthermore, the use of a metal case or a base has a problem that the current sensor is enlarged and the installation location is limited.

  Further, in the coreless type current sensor disclosed in Patent Document 3, a ferromagnetic material is arranged substantially in parallel so as to sandwich the U-shaped primary conductor and the magnetoelectric conversion element, so that the magnetoelectric conversion element can be efficiently used. It is configured to collect magnetic flux. However, there is no particular disclosure about the means for installing the magnetoelectric conversion element and the ferromagnetic material, the space for ensuring insulation, and the shield layer, and there are many problems in miniaturization, cost reduction, and high accuracy. There was a problem.

  The present invention has been made in order to solve the above-described problems. The dielectric breakdown voltage between the magnetoelectric conversion element and the primary conductor is easily secured, and electric field noise from the primary conductor is removed or reduced, so that the measurement range can be reduced. Therefore, an object of the present invention is to obtain a current sensor that can be easily varied, can accurately detect even a small current to be measured, and is small in size and low in cost.

Means for solving the problem

  A current sensor according to the present invention is a multilayer printed wiring board in which electronic layers, semiconductor elements, and the like are built in which conductor layers and insulating layers are alternately laminated. The semiconductor element is at least one magnetoelectric conversion element. Magnetoelectric transducers are arranged in different layers in the vicinity of the primary conductor pattern provided on at least one conductor layer of the wiring board.

  In addition, the current sensor according to the present invention is provided in a multilayer printed wiring board with a conductive layer disposed on at least one upper layer of the electronic component built-in surface having a magnetoelectric conversion element and at least one lower layer of the electronic component built-in surface having the magnetoelectric conversion element. And a shield layer having a ground potential is installed.

  In addition, the current sensor according to the present invention has a conductive layer formed on the inner layer surface of at least one multilayer printed wiring board located between the electronic component built-in surface having the magnetoelectric conversion element and the primary conductor pattern arrangement surface in the multilayer printed wiring board. And a shield layer having a ground potential is installed.

  In the current sensor according to the present invention, in the multilayer printed wiring board, the primary conductor pattern is obtained by reducing the width of the primary conductor pattern in the vicinity of the magnetoelectric transducer.

  The current sensor according to the present invention is a multilayer printed wiring board in which the primary conductor pattern is arranged so as to circulate in the vicinity of the magnetoelectric transducer.

  The current sensor according to the present invention has a plurality of primary conductor patterns on a multilayer printed wiring board, and the primary conductor pattern has at least one upper layer of an electronic component built-in surface having a magnetoelectric conversion element and a magnetoelectric conversion element. It is arranged in at least one lower layer of the electronic component built-in surface.

  The current sensor according to the present invention is a multilayer printed wiring board, wherein a plurality of primary conductor patterns are formed on at least one upper layer of an electronic component built-in surface having a magnetoelectric conversion element and at least an electronic component built-in surface having a magnetoelectric conversion element. It is arranged in one lower layer and a plurality of primary conductor patterns are serially connected.

  The current sensor according to the present invention is a multilayer printed wiring board, wherein a plurality of primary conductor patterns are formed on at least one upper layer of an electronic component built-in surface having a magnetoelectric conversion element and at least an electronic component built-in surface having a magnetoelectric conversion element. It is arranged in one lower layer and a plurality of primary conductor patterns are connected in parallel.

  In addition, the current sensor according to the present invention is a multilayer printed wiring board, wherein the inner layer surface having the primary conductor pattern is at least one inner layer surface or outer layer surface facing the electronic component built-in surface having the magnetoelectric transducer, or the Both are provided with a ferromagnetic material layer.

  The current sensor according to the present invention is a multilayer printed wiring board in which a connector for connecting an electronic component and an external terminal installed on the multilayer printed wiring board including at least one magnetoelectric conversion element is installed. is there.

  The current sensor according to the present invention is a multilayer printed wiring board in which at least one magnetoelectric conversion element is a Hall IC.

  In the current sensor according to the present invention, in the multilayer printed circuit board, the built-in electronic component is two Hall ICs, and includes differential output means of two Hall ICs, and the primary conductor pattern is two Hall ICs. Is circulated in an S shape.

The invention's effect

  As described above, according to the present invention, the primary conductor pattern is formed using the conductor layer pattern of at least one inner layer of the multilayer printed wiring board, and the magnetoelectric conversion element is also formed on the inner layer surface different from the primary conductor pattern forming surface. By incorporating it, the withstand voltage between the primary conductor pattern and the magnetoelectric conversion element is improved, and the multilayer printed wiring board can be reduced and the cost can be reduced as compared with the case where the primary conductor pattern and the magnetoelectric conversion element are exposed. Since the primary conductor pattern and the magnetoelectric transducer can be approached, there is an effect that a small-capacity current to be measured can be accurately detected.

  In addition, by installing a shield layer on the inner layer of the multilayer printed wiring board so as to be positioned between the magnetoelectric conversion element and the primary conductor pattern forming surface, the primary conductor pattern caused mainly by the primary conductor pattern is moved in the direction of the magnetoelectric conversion element. There is an effect of removing or reducing electric field noise. In addition, a shield layer having conductivity and ground potential is provided on at least one upper layer and at least one lower layer of the electronic component built-in surface having the magnetoelectric conversion element, so that the primary conductor pattern is positioned. Regardless, there is an effect of removing or reducing electric field noise applied to the magnetoelectric transducer from the outside.

  Also, by installing the shield layer on the inner layer of the multilayer printed wiring board, the process of installing the shield layer can be simplified, and the cost can be reduced.

  In addition, since the primary conductor pattern is produced on the multilayer printed wiring board, the width of the primary conductor pattern and the installation position can be easily changed compared to the use of a metal conductor, and the current detection range can be changed while the magnetoelectric transducer remains the same. There is an effect that can be done. In addition, by providing multiple primary conductor patterns on the same multilayer printed wiring board and changing the connection point, such as serial or parallel, depending on the current capacity to be measured, the multilayer printed wiring board and the magnetoelectric transducer remain the same, and current detection is performed. There is an effect that the range can be varied.

  Furthermore, by installing a ferromagnetic material on the multilayer printed circuit board, the installation of the magnetic material is simplified, and there is an effect that the magnetic current can be easily collected on the magnetoelectric transducer, and a small-capacity measured current can be obtained. There is an effect that can be detected with high accuracy.

  Furthermore, when a programmable Hall IC is used for the magnetoelectric conversion element, sensitivity and temperature characteristics can be adjusted only by electrical adjustment, so that adjustment as a current sensor can be simplified, and the cost can be reduced. .

  Furthermore, by using two Hall ICs for the magnetoelectric conversion element and arranging the primary conductor pattern so that the two Hall ICs circulate in an S shape, a magnetic flux in the opposite direction can be applied to each of the two Hall ICs. By taking the differential output of both, it is possible to remove the uniform external magnetic field and to improve the accuracy.

It is a perspective view of the current sensor by Embodiment 1 of this invention. It is a top view of the current sensor by Embodiment 1 of this invention. It is sectional drawing of the current sensor by Embodiment 1 of this invention. It is a magnetic field vector and decomposition | disassembly vector of Hall IC vicinity shown in FIG. 3 of the current sensor by Embodiment 1 of this invention. It is a top view of another current sensor by Embodiment 1 of this invention. It is sectional drawing of another current sensor by Embodiment 1 of this invention. It is a top view of another current sensor by Embodiment 1 of this invention. It is sectional drawing of another electric current sensor by Embodiment 1 of this invention. It is another sectional view of another current sensor by Embodiment 1 of this invention. It is a top view of the current sensor by Embodiment 2 of this invention. It is sectional drawing of the current sensor by Embodiment 2 of this invention. It is sectional drawing of another current sensor by Embodiment 2 of this invention. It is a top view of another current sensor by Embodiment 2 of this invention. It is sectional drawing of another electric current sensor by Embodiment 2 of this invention. It is a top view of the current sensor by Embodiment 3 of this invention. It is sectional drawing of the current sensor by Embodiment 3 of this invention. It is another sectional drawing of the current sensor by Embodiment 3 of this invention. It is another sectional drawing of the current sensor by Embodiment 3 of this invention. It is sectional drawing of another current sensor by Embodiment 3 of this invention.

Embodiment 1 FIG.
1 is a perspective view of a current sensor according to Embodiment 1 of the present invention, FIG. 2 is a plan view of FIG. 1, and FIG. 3 is a cross section showing an AA ′ cross section (XZ plane) in FIGS. FIG. In the figure, a current sensor 1 is constituted by a multilayer printed wiring board 2 having a primary conductor pattern 3, a Hall IC 4 and a shield layer 5 incorporated therein.
In the first embodiment, the multilayer printed wiring board 2 in which the conductor layers and the insulating layers are alternately laminated has the five inner layers 8, and the primary conductor pattern 3 uses the conductor layers provided on the inner layer 8e. Take the installed structure. The multilayer printed wiring board 2 incorporates a Hall IC 4 as one magnetoelectric conversion element. A connector 7 is installed on the upper surface of the multilayer printed wiring board 2 as an input / output terminal of the current sensor. A shield layer 5 is provided on the inner layers 8 a and 8 d of the multilayer printed wiring board 2.

First, the configuration of the multilayer printed wiring board 2 will be described.
FIG. 3 is a cross-sectional view showing the AA ′ cross section (XZ plane) in FIGS. 1 and 2 of the multilayer printed wiring board 2. In recent years, with the increasing demand for multi-functionality, miniaturization, and thinning of electronic devices, development and practical application of component-incorporated wiring technology are progressing. Part of this technique is also used in this embodiment. The component-embedded wiring board has progressed from the fabrication of embedded passive components such as capacitors, resistors, and inductors to the embedded technology of active components such as bare chips and packages. In this embodiment, the Hall IC 4 that is an active component is used. Built-in board. A Hall IC is a bare chip or packaged IC in which a Hall element and a processing circuit are integrated. By using a programmable Hall IC, adjustment of sensitivity, temperature characteristics, etc. can be performed only by electrical adjustment. This is possible, and adjustment as a current sensor can be simplified, so that the cost can be reduced. A cavity 11 for embedding the Hall IC 4 is provided in the insulating layer 10 sandwiched between the inner layers 8b and 8c, and the Hall IC 4 is installed. In the present embodiment, the insulating layer 10 is an electronic component built-in surface. The form of the Hall IC 4 may be a bare chip or a package product, but it is desirable that the Hall IC 4 be a bare chip rather than a package product in order to reduce the thickness. In addition, the portion where the Hall IC 4 is embedded is an insulating layer in the present embodiment, but is not limited to the insulating layer, and may be a copper core instead of the insulating layer. By using a copper core, it is possible to expect an improvement in heat dissipation characteristics and an electric field shielding effect. The connection between the Hall IC 4 and the multilayer printed wiring board 2 is made by bumps made of metal formed on the Hall IC 4 although not particularly shown in the drawing. The material of the bump is, for example, gold or solder. Although the bump formation method varies depending on the material, there are a printing method, a plating method, a ball mounting method, a stud bump, and the like. The side electrically connected to the multilayer printed wiring board 2 may be either the upper or lower conductor layer when the Hall IC 4 is installed on the insulating layer, but if it is installed on the copper core, the copper core Since it is not desirable from the viewpoint of insulation to provide a conductor layer on the top, it is desirable to connect to the upper conductor layer. The Hall IC 4 and the multilayer printed wiring board 2 can be connected by wire bonding, but it is advantageous to use bumps for miniaturization. Although input / output of the Hall IC 4 is not particularly shown, it is taken out from the upper surface of the multilayer printed wiring board 2 through a through via. In this embodiment, as shown in FIG. 1, it is configured to be connected to an external device or the like via the connector 7. However, the present invention is not limited to this, and a terminal may be provided and connected to the outside by soldering or the like. Good.

  On the first inner layer 8a and the fourth inner layer 8d of the multilayer printed wiring board 2, a conductive shield layer 5a and a shield layer 5b are provided, respectively. The shield layer 5b is for removing or reducing electric field noise applied to the Hall IC 4 mainly due to the primary conductor 3 as noise that degrades the performance as a current sensor. It is desirable to install between the primary conductors 3. The shield layer 5a is for removing or reducing electric field noise applied to the Hall IC 4 from the outside. The material of the shield layer 5 is only required to be conductive. For example, copper, aluminum and the like are conceivable, and the shield layer 5 is connected to an electrical ground provided on the multilayer printed wiring board 2. In the present embodiment, only the Hall IC 4 is installed as a built-in component. However, when other circuit components are installed, they are arranged between the two shield layers 5a and 5b as much as possible as in the Hall IC 4. Is desirable.

  As shown in FIG. 3, the primary conductor pattern 3 to which the current to be measured is applied is provided using the conductor layer pattern of the fifth inner layer 8 e of the multilayer printed wiring board 2, and is integrated with the multilayer printed wiring board 2. 1, the shape of the primary conductor pattern 3 is a straight line having the same width passing through the vicinity of the Hall IC 4 when viewed from the Z direction. The width and thickness of the primary conductor pattern 3 are determined according to the measured current value to be applied. The arrangement of the primary conductor pattern 3 with respect to the installation position of the Hall IC 4 determines the magnetic flux density to be applied to the Hall IC 4, that is, the current to be measured. Decide according to the size. The magnetic flux density desired to be applied to the Hall IC 4 can be adjusted by changing the thickness of the inner layer of the multilayer printed wiring board 2, but in this embodiment, as shown in another example described later, the primary conductor is as much as possible. By changing only the arrangement and shape of the pattern 3, the magnetic flux density desired to be applied to the Hall IC 4 is adjusted. The installation position of the Hall IC 4 and the inner layer thickness of the multilayer printed wiring board 2 do not change even if the magnitude of the current to be measured changes, and can be fixed, that is, by reducing the variable parameters, the manufacturing process can be simplified, Cost reduction. For the input / output of the current to be measured, the primary conductor pattern input / output end 6 connected to the primary conductor pattern 3 through a through via or a through hole is used. In particular, a terminal or the like is not provided, but the present embodiment is not limited to this, and a conductive terminal or connector may be used for connection.

Next, the operation of the current sensor 1 will be described with reference to FIG.
When a current to be measured is applied to the primary conductor pattern 3, an elliptical magnetic flux line 12 indicated by a broken line in FIG. 3 is generated according to the magnitude of the current to be measured. Although only one magnetic flux line is shown here for the sake of simplicity, a magnetic flux line substantially similar to the magnetic flux line 12 having a larger magnetic flux density near the primary conductor pattern 3 in the vicinity of the primary conductor pattern 3. Has occurred. In the present embodiment, the magnetic flux in the Z direction is measured out of the plane of the Hall element provided inside the Hall IC 4, that is, a magnetoelectric conversion element having a magnetosensitive direction in the out-of-plane direction is used. When the Hall IC 4 is installed at the position shown in FIG. 3, the magnetic flux vector 13 shown in FIG. 4 is applied to the Hall IC 4, and the decomposition vector 13z is added to the magnetic sensing direction (Z-axis direction) of the Hall IC 4. . In order to apply a large magnetic flux density to the Hall IC 4 without changing the cross-sectional shape and routing of the primary conductor pattern 3, the primary conductor pattern 3 may be brought close to the Hall IC 4, and in order to apply a small magnetic flux density, The primary conductor pattern 3 only needs to be away from the Hall IC 4.

FIG. 5 is a plan view of a current sensor having another primary conductor pattern 3 according to Embodiment 1 of the present invention, and FIG. 6 is a diagram of a current sensor having another primary conductor pattern 3 according to Embodiment 1 of the present invention. It is sectional drawing which shows the AA 'cross section (XZ surface) of FIG. 5 and 6 show a configuration in which only the primary conductor pattern 3 is changed as compared with FIGS. 2 and 3 described above, and redundant portions in other configurations and operations are omitted.
As can be seen from the plan view of FIG. 2, in the previous example, the width of the primary conductor pattern 3 was not changed and remained constant, and was provided using the conductor layer pattern of the fifth inner layer 8e of the multilayer printed wiring board 2. However, in another example as shown in FIGS. 5 and 6, the width of the primary conductor pattern 3, that is, the cross-sectional area is reduced only in the vicinity of the Hall IC 4. By reducing the width dimension of the primary conductor pattern 3, the current density increases, and consequently the generated magnetic flux density increases, and the magnetic flux density applied to the Hall IC 4 increases. Thus, even with the same current to be measured, the magnetic flux density applied to the Hall IC 4 can be easily varied. Further, by reducing the width dimension of the primary conductor pattern 3 only in the vicinity of the Hall IC 4, heat generation due to an increase in current density can be suppressed.

FIG. 7 is a plan view of a current sensor having still another primary conductor pattern 3 according to Embodiment 1 of the present invention, and FIG. 8 is a current having still another primary conductor pattern 3 according to Embodiment 1 of the present invention. FIG. 9 is a sectional view taken along the line AA ′ (XZ plane) of FIG. 7, and FIG. 9 is a sectional view taken along the line BB ′ (YZ plane) of FIG. 7 of the current sensor according to Embodiment 1 of the present invention. FIG. 7, 8, and 9 are configurations in which only the primary conductor pattern 3 is changed as compared with FIGS. 2 and 3 described above, and redundant portions in other configurations and operations are omitted.
As can be seen from the plan view of FIG. 2, in the previous example, the width of the primary conductor pattern 3 was not changed and remained constant, and was provided using the conductor layer pattern of the fifth inner layer 8e of the multilayer printed wiring board 2. However, as shown in FIGS. 7, 8, and 9, in another example, only in the vicinity of the Hall IC 4, the width, that is, the cross-sectional area of the primary conductor pattern 3 is reduced, and the Hall IC 4 is circulated. . By reducing the width of the primary conductor pattern 3, that is, the cross-sectional area, the current density increases, and consequently the generated magnetic flux density increases, and the magnetic flux density applied to the Hall IC 4 increases. 8 and 9, the primary conductor pattern 3 circulates in the vicinity of the Hall IC 4 so that in this example, the magnetic flux density in the magnetically sensitive direction increases from the three directions. A magnetic flux density is applied to the IC 4. In this way, the magnetic flux density applied to the Hall IC 4 can be easily varied by changing the primary conductor pattern 3 even with the same current to be measured. Further, by reducing the cross-sectional area of the primary conductor pattern 3 only in the vicinity of the Hall IC 4, heat generation due to an increase in current density can be suppressed. Note that the direction of the magnetic flux applied to the Hall IC 4 is opposite to that of the other examples. However, since the positive / negative of the output is easy due to the programmable electrical adjustment of the Hall IC, there is no particular problem. .

  As described above, according to the first embodiment, the primary conductor pattern is formed using the conductor layer pattern of the inner layer of the sensor substrate, and the Hall IC that is a magnetoelectric conversion element is also built in. The dielectric strength between the Hall ICs is improved, and the multilayer printed wiring board can be reduced and the cost can be reduced as compared with the case where the primary conductor pattern and the Hall IC are exposed, and the primary conductor pattern and the Hall IC can be brought close to each other. Therefore, there is an effect that a small current to be measured can be accurately detected.

  Also, by installing a shield layer in the multilayer printed wiring board inner layer between the Hall IC and the primary conductor pattern, the effect of removing or reducing the electric field noise from the primary conductor pattern mainly due to the primary conductor pattern in the Hall IC direction There is. In addition, by installing a shield layer that is electrically conductive and has a ground potential on the lower layer side of the Hall IC without the primary conductor pattern, electric field noise applied to the Hall IC from the outside can be removed or reduced. There is an effect to.

  In addition, since the primary conductor pattern is produced on the multilayer printed wiring board, the width of the primary conductor pattern and the installation position can be easily changed compared to the use of a metal conductor, and the specifications such as the Hall IC sensitivity and the installation position remain the same. The current detection range can be varied. Further, by reducing the width of the primary conductor pattern only in the vicinity of the Hall IC, there is an effect of suppressing heat generation due to an increase in current density.

  Furthermore, since a programmable Hall IC is used for the magnetoelectric conversion element, sensitivity and temperature characteristics can be adjusted only by electrical adjustment, so that adjustment as a current sensor can be simplified and there is an effect of cost reduction.

Embodiment 2. FIG.
10 is a plan view of a current sensor according to Embodiment 2 of the present invention, and FIG. 11 is a cross-sectional view showing an AA ′ section (XZ plane) in FIG. In the figure, the current sensor 1 is composed of a multilayer printed wiring board 2 having two primary conductor patterns 3, a Hall IC 4 and a shield layer 5.
In the second embodiment, the multilayer printed wiring board 2 in which conductor layers and insulating layers are alternately laminated has six inner layers 8, and the primary conductor pattern 3 uses a conductor layer provided on the inner layer 8a. The primary conductor pattern 3a installed and the primary conductor pattern 3b installed using the conductor layer provided on the inner layer 8f are used. The multilayer printed wiring board 2 incorporates a Hall IC 4 as one magnetoelectric conversion element. A shield layer 5 is provided on the inner layers 8 b and 8 e of the multilayer printed wiring board 2.
The second embodiment is a configuration in which the primary conductor pattern 3 is installed in two layers as compared with the first embodiment, and the redundant portions in other configurations and operations are omitted.

As shown in FIG. 11, the primary conductor pattern 3 to which the current to be measured is applied is provided by using the two conductor layer patterns of the first inner layer 8a and the sixth inner layer 8f of the multilayer printed wiring board 2. Therefore, the distance from the Hall IC 4 to each primary conductor pattern 3 is substantially the same. Further, as indicated by a broken line in FIG. 10, the primary conductor pattern 3 has a configuration in which the width of the primary conductor pattern 3 is reduced only in the vicinity of the Hall IC 4 as viewed from the Z direction. The reduction in the width dimension of the primary conductor pattern 3, that is, the cross-sectional area, increases the current density, and consequently increases the generated magnetic flux density, and the magnetic flux density applied to the Hall IC 4 increases. It is the same.
First, a case where the current to be measured is simultaneously connected to the primary conductor pattern input / output ends 6a1 and 6b1 and divided, that is, in parallel, to apply the magnetic flux density to the Hall IC 4 will be described. In this case, although the magnetic flux density generated in the individual primary conductor patterns 3a and 3b is reduced by the shunting, the magnetic flux is generated in the primary conductor patterns of the two layers. Only, or when connected to 6a2 only, the magnetic flux density value applied to the Hall IC 4 is the same. However, since the current density in the individual primary conductor patterns 3a and 3b is reduced by the diversion, heat generation can be suppressed.
Next, a case where the current to be measured is connected to the primary conductor pattern input / output end 6a1 and the primary conductor pattern input / output ends 6a2 and 6b1 are connected in series to apply the magnetic flux density to the Hall IC 4 will be described. . In this case, since there is no shunting, the magnetic flux density generated in each primary conductor pattern 3a, 3b does not decrease, compared to the case where the same current to be measured is connected only to the primary conductor pattern input / output end 6a1 or only to 6a2. Twice the magnetic flux density can be applied to the Hall IC 4. That is, the measurable rating as the current sensor can be varied without greatly changing the configuration.

Next, another configuration example according to the second embodiment is shown. FIG. 12 is a cross-sectional view of a current sensor having a ferromagnetic material 14 according to Embodiment 2 of the present invention. FIG. 12 is a configuration in which only the ferromagnetic material 14 is newly added as compared with FIGS. 10 and 11 described above, and the redundant portions in other configurations and operations are omitted.
As shown in FIG. 12, this another example has a configuration in which the ferromagnetic material 14 is disposed on the upper and lower layers of the multilayer printed wiring board 2 in the vicinity of the Hall IC 4 and the primary conductor pattern 3. By installing the ferromagnetic material 14, the magnetic flux leaking to the outside of the multilayer printed wiring board 2 is collected in the ferromagnetic material 14 and applied to the Hall IC 4 as shown by the thick broken line in FIG. As a result, the magnetic flux density increases. In this way, even with the same current to be measured, the magnetic flux density applied to the Hall IC 4 can be easily increased by adding the ferromagnetic material 14. The ferromagnetic material 14 may be a bulk material such as permalloy, but is not limited thereto, and an amorphous magnetic material or the like that can be formed in a foil shape may be used to be contained in the inner layer of the multilayer printed wiring board 2. . In the case of a bulk material such as permalloy, various methods such as bonding and screwing can be considered as the installation method. However, the installation process is easy because it is installed on the planar surface layer of the multilayer printed wiring board 2. .

FIG. 13 is a plan view of a current sensor having another primary conductor pattern 3 according to Embodiment 2 of the present invention, and FIG. 14 is a cross section of a current sensor having another primary conductor pattern 3 according to Embodiment 2 of the present invention. FIG. 13 and FIG. 14 are configurations in which only the primary conductor pattern 3 is changed as compared with FIGS. 10 and 11 described above, and redundant portions in other configurations and operations are omitted.
As can be seen from FIGS. 10 and 11, in the previous example, each primary conductor pattern 3 has a substantially equal distance from the Hall IC 4, but in another example as shown in FIGS. 13 and 14, Each primary conductor pattern 3 is installed at a different distance from the Hall IC 4.
A case will be described in which the current to be measured is simultaneously connected to the primary conductor pattern input / output ends 6a1 and 6b1 and divided, that is, in parallel to apply the magnetic flux density to the Hall IC 4. In this case, the magnetic flux density generated in the individual primary conductor patterns 3a and 3b is reduced by the diversion, and magnetic flux is generated in the primary conductor patterns of the two layers, but the installation positions of the individual primary conductor patterns 3a and 3b are different. The magnetic flux density value applied to the Hall IC 4 is lower than when the same current to be measured is connected to only the primary conductor pattern input / output end 6a1 or 6a2. In this way, even if the current to be measured is the same, the magnetic flux density applied to the Hall IC 4 can be easily reduced by diverting only one primary conductor pattern away from the Hall IC 4. Moreover, since the current density in each primary conductor pattern 3a, 3b falls by shunting, it becomes possible to suppress the heat_generation | fever of a primary conductor pattern.

  As described above, according to the second embodiment, a plurality of primary conductor patterns are provided in the same multilayer printed wiring board, and the connection point is varied such as serial or parallel depending on the current capacity to be measured. While the configuration of the wiring board and the installation position of the Hall IC are the same, the magnetic flux density applied to the Hall IC can be varied, and thus the current detection range can be varied.

  In addition, by installing a ferromagnetic material on the surface layer of the multilayer printed wiring board, the installation of the magnetic material is simplified, and there is an effect that the magnetic flux can be easily collected with respect to the Hall IC. Can be accurately detected.

Embodiment 3 FIG.
15 is a plan view of a current sensor according to Embodiment 3 of the present invention. FIG. 16 is a cross-sectional view showing the AA ′ cross section (XZ plane) in FIG. 15, and FIG. 17 is a BB ′ cross section in FIG. XZ plane), and FIG. 18 is a cross sectional view showing a CC ′ section (YZ plane) in FIG. In the figure, a current sensor 1 is constituted by a multilayer printed wiring board 2 having a primary conductor pattern 3, two Hall ICs 4 and a shield layer 5.
In the third embodiment, the multilayer printed wiring board 2 in which the conductor layers and the insulating layers are alternately laminated has the five inner layers 8, and the primary conductor pattern 3 uses the conductor layers provided on the inner layer 8e. To install. The multilayer printed wiring board 2 incorporates two Hall ICs 4 as magnetoelectric conversion elements. A shield layer 5 is provided on the inner layers 8 a and 8 d of the multilayer printed wiring board 2.
The third embodiment is a configuration in which two Hall ICs 4 are installed as compared with the first embodiment, and the redundant portions in other configurations and operations are omitted.

As can be seen from the plan view of FIG. 7, in the previous example, one Hall IC 4 is installed, and only in the vicinity of the Hall IC 4, the width of the primary conductor pattern 3, that is, the cross-sectional area is reduced, and the Hall IC 4 is primary. The conductor pattern 3 was configured to go around. As shown in FIG. 15, in the present embodiment, two Hall ICs 4 are installed, and the width, that is, the cross-sectional area of the primary conductor pattern 3 is reduced only in the vicinity of each Hall IC 4, and each Hall IC 4. The primary conductor pattern 3 circulates in the opposite direction. By reducing the width dimension of the primary conductor pattern 3, the cross-sectional area of the primary conductor pattern 3 is reduced, the magnetic flux density generated simultaneously with the increase in current density is increased, and the magnetic flux density applied to the Hall IC 4 is increased. 7 and the primary conductor pattern 3 circulates in the vicinity of the Hall IC 4, the magnetic flux density is applied to the Hall IC 4 so as to increase the magnetic flux density in the magnetic sensing direction, as in the configuration of FIG. 7.
First, the direction of the magnetic flux applied to each Hall IC 4 when a current to be measured is applied in one direction will be described. In FIG. 16, the direction of magnetic flux applied from the primary conductor pattern 3 to the magnetic sensing direction of the Hall IC 4a is the + Z direction. In FIG. 18, the magnetic flux applied from the primary conductive pattern 3a and 3b to the magnetic sensing direction of the Hall IC 4a. The direction of is the + Z direction. That is, it can be seen from the primary conductor pattern 3 that circulates around the Hall IC 4a that the direction of the magnetic flux applied in the magnetic sensing direction of the Hall IC 4a is all in the + Z direction. In FIG. 17, the direction of the magnetic flux applied from the primary conductor pattern 3 to the magnetic sensing direction of the Hall IC 4b is the -Z direction. In FIG. 18, the magnetic flux is applied from the primary conductor patterns 3b and 3c to the magnetic sensing direction of the Hall IC 4b. The direction of the magnetic flux is the −Z direction. That is, it can be seen from the primary conductor pattern 3 that circulates around the Hall IC 4b that the direction of the magnetic flux applied in the magnetic sensing direction of the Hall IC 4b is all in the −Z direction. Thus, the magnetic fluxes in the opposite directions are applied to the individual Hall ICs 4 when the primary conductor pattern 3 circulates around the S-shape on the two Hall ICs 4, that is, in the opposite direction.

  Output as a current sensor is performed by taking the differential output of the two Hall ICs 4. Since magnetic fluxes in opposite directions are applied to the individual Hall ICs 4, positive and negative and reverse outputs are obtained from the individual Hall ICs 4. Therefore, by performing differential processing, the output of the sensor is doubled and in phase. Uniform external magnetic field effects and noise are eliminated. Therefore, it is possible to increase the accuracy of the sensor output. It is desirable to install the additional circuit for differential processing on the electronic component built-in surface on which the Hall IC 4 is installed. However, if it is difficult to install the electronic component built-in surface due to the dimensions and circuit scale of the additional circuit component, a multilayer It is installed on the front surface or the back surface of the printed wiring board 2 and connected to the Hall IC 4 by through vias or the like. FIG. 19 shows a cross-sectional view of another current sensor 1 according to the present embodiment to which an additional circuit 15 is added. Thus, when providing the additional circuit 15 in the outer layer (here surface) of the multilayer printed wiring board 2, the inner layer 8f is added between the primary conductor pattern 3 and the additional circuit 15, and the shield layer 5c is newly installed. Is desirable. By providing the shield layer 5c, there is an effect of removing or reducing electric field noise from the primary conductor pattern 3 to the additional circuit 15 due to the primary conductor pattern 3.

  As described above, according to the third embodiment, two Hall ICs are used for the magnetoelectric conversion element, and the primary conductor pattern is arranged so as to circulate around the two Hall ICs in an S shape. Since reverse magnetic fluxes can be applied to each IC, taking the differential output of both has the effect of eliminating the effects of uniform external magnetic fields, noise, etc., and improving accuracy.

1 current sensor, 2 multilayer printed wiring board, 3 primary conductor pattern, 4 Hall IC, 5 shield layer, 6 primary conductor pattern input / output end, 7 connector, 8 inner layer, 9 center line, 10 insulating layer, 11 cavity, 12 Magnetic flux line, 18 Magnetic flux vector, 14 Ferromagnetic material, 15 Additional circuit

Claims (12)

  In a multilayer printed wiring board in which a conductor layer and an insulating layer are alternately stacked, including an electronic component or a semiconductor element, the semiconductor element is at least one magnetoelectric conversion element, and at least one of the multilayer printed wiring board A current sensor, wherein a magnetoelectric conversion element is arranged in a layer different from a layer provided with the primary conductor pattern, in the vicinity of the primary conductor pattern provided in the conductor layer.   In the multilayer printed wiring board, the at least one upper layer of the electronic component built-in surface having the magnetoelectric conversion element and the at least one lower layer of the electronic component built-in surface having the magnetoelectric conversion element have conductivity and a ground The current sensor according to claim 1, wherein a shield layer having a potential is provided.   In the multilayer printed wiring board, at least one inner layer surface of the multilayer printed wiring board located between the electronic component built-in surface having the magnetoelectric conversion element and the primary conductor pattern has conductivity and has a ground potential. The current sensor according to claim 1, wherein a shield layer is provided.   4. The current sensor according to claim 1, wherein, in the multilayer printed wiring board, the primary conductor pattern has a reduced primary conductor pattern width in the vicinity of the magnetoelectric transducer. 5.   5. The current sensor according to claim 1, wherein in the multilayer printed wiring board, the primary conductor pattern is arranged so as to circulate in the vicinity of the magnetoelectric conversion element.   In the multilayer printed wiring board, a plurality of the primary conductor patterns are installed, and the primary conductor pattern includes at least one upper layer of the electronic component built-in surface having the magnetoelectric conversion element, and the electronic component built-in having the magnetoelectric conversion element. The current sensor according to claim 1, wherein the current sensor is disposed in at least one lower layer of the surface.   In the multilayer printed wiring board, a plurality of the primary conductor patterns are disposed on at least one upper layer of the electronic component built-in surface having the magnetoelectric conversion element and at least one lower layer of the electronic component built-in surface having the magnetoelectric conversion element. The current sensor according to any one of claims 1 to 6, wherein a plurality of primary conductor patterns are arranged and connected in series.   In the multilayer printed wiring board, a plurality of the primary conductor patterns are disposed on at least one upper layer of the electronic component built-in surface having the magnetoelectric conversion element and at least one lower layer of the electronic component built-in surface having the magnetoelectric conversion element. The current sensor according to any one of claims 1 to 6, wherein a plurality of primary conductor patterns are arranged and connected in parallel.   In the multilayer printed wiring board, a ferromagnetic material layer is provided on at least one inner layer surface and / or outer layer surface facing the electronic component built-in surface having the magnetoelectric conversion element with respect to the inner layer surface having the primary conductor pattern. The current sensor according to claim 1, wherein the current sensor is installed.   2. The multilayer printed wiring board according to claim 1, further comprising a connector for connecting an external component and an electronic component installed on the multilayer printed wiring board including at least one magnetoelectric conversion element. The current sensor according to 9.   11. The current sensor according to claim 1, wherein at least one of the magnetoelectric conversion elements is a Hall IC in the multilayer printed wiring board.   In the multilayer printed wiring board, the electronic component is two Hall ICs, and includes differential output means of the two Hall ICs, and the primary conductor pattern circulates the two Hall ICs in an S shape. The current sensor according to claim 11.

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