WO2016017334A1

WO2016017334A1 - Electrical current detection apparatus

Info

Publication number: WO2016017334A1
Application number: PCT/JP2015/068427
Authority: WO
Inventors: 宗貴岡本; 順哉若林
Original assignee: 株式会社東海理化電機製作所
Priority date: 2014-07-29
Filing date: 2015-06-25
Publication date: 2016-02-04
Also published as: JP2016031304A

Abstract

Provided is an electrical current detection apparatus with both improved noise performance and solderability, the electrical current detection apparatus comprising a substrate 20 disposed in the vicinity of a conductor 10 that generates a peripheral magnetic flux through the flow of an electrical current, and an SIP-type magnetic detection element 30 comprising a plurality of leads arranged at a predetermined pitch P, the leads (31a, 31b, 31c) being mounted by being inserted into lead apertures (21a, 21b, 21c) of the substrate 20. The leads of the magnetic detection element 30 are formed without widening the predetermined pitch P in the arrangement direction, and are inserted into the substrate 20.

Description

Current detector

The present invention relates to a current detection device, and more particularly to a current detection device that includes a magnetic detection element and performs current detection.

There is a current sensor that is disposed in the vicinity of a conductor that performs current measurement and measures a current flowing through the conductor by detecting a magnetic flux generated by the current flowing through the conductor. Such a current sensor is configured by storing a core having a gap and a magnetoelectric conversion element arranged in the gap of the core in a component storage chamber in the case, and filling the component storage chamber with a molding agent. (For example, refer to Patent Document 1). The Hall IC, which is a magnetoelectric conversion element, is mounted with its leads inserted into the lead holes of the substrate and soldered on the back surface of the substrate.

While the lead pitch of the IC is narrowed, it is necessary to provide an appropriate pin-to-pin pitch in order to reduce short-circuit defects in solder connection. However, if the lead frame is widened to ensure the pin-to-pin pitch, there is a problem that the area where the magnetic flux intersects increases and the noise performance of the current detection device decreases.

JP 2006-78255 A

An object of the present invention is to provide a current detection device that simultaneously improves noise performance and solderability.

[1] A current detection device according to an embodiment of the present invention includes a substrate disposed in the vicinity of a conductor that generates a magnetic flux around when a current flows, and a plurality of leads arranged at a predetermined pitch, And a SIP type magnetic detection element mounted with the lead inserted into the substrate, and the lead of the magnetic detection element is formed without expanding the predetermined pitch in the arrangement direction and inserted into the substrate. Has been implemented.

[2] In the magnetic detection element according to [1], the leads may be formed in a direction intersecting the arrangement direction.

[3] In the magnetic detection element according to [1], the leading end side of the lead may be formed corresponding to the lead hole of the substrate.

[4] The magnetic detection element according to [1] to [3] may be formed and mounted so that an area where the magnetic flux interlinks with the leads or between the leads does not increase.
[5] The magnetic detection elements according to [1] to [4] may be arranged so that an extending direction of the conductor is orthogonal to the arrangement direction of the leads.
[6] The forming described in [1] to [5] may be performed so that a pitch (L) between leads after the forming exceeds the predetermined pitch (P).
[7] The conductor according to [1] to [6] may include a bus bar.

According to an embodiment of the present invention, it is possible to provide a current detection device that simultaneously improves noise performance and solderability.

FIG. 1 is a perspective view showing a current detection device according to an embodiment of the present invention. FIG. 2 is a plan view showing the current detection device viewed from the direction A in FIG. FIG. 3A is a front view showing the SIP type magnetic sensing element in a state where it is formed with three leads. FIG. 3B is a right side view seen from the direction C in FIG. 3A. 3C is a plan view seen from the direction D in FIG. 3B. FIG. 4A is a front view showing a SIP type magnetic sensing element having four leads. FIG. 4B is a front view showing the SIP-type magnetic detection element in a formed state. Figure 5A is a front view showing between the lead or lead and flux B is the interlinked area S ₁ in SIP type magnetic sensor in a state of being forming includes three leads. Figure 5B is a front view showing a is interlinked area S ₂ between the leads or leads and the magnetic flux B in the SIP type magnetic sensor in a state of being forming includes four leads. FIG. 6 is a relationship diagram illustrating the relationship between area × magnetic flux and transient characteristic noise peak value. FIG. 7 is a waveform diagram showing the correspondence between the input current and the output voltage of the magnetic detection element that detects the magnetic flux generated by this input current.

[Embodiments of the present invention]
(Configuration of current detection device)
FIG. 1 is a perspective view showing a current detection device according to an embodiment of the present invention. FIG. 2 is a plan view showing the current detection device viewed from the direction A in FIG.

The current detection device 1 according to the embodiment of the present invention has a substrate 20 disposed in the vicinity of a conductor 10 that generates a magnetic flux around it when a current flows, and a plurality of leads arranged at a predetermined pitch P. , And a SIP type magnetic detection element 30 mounted with the leads (31a, 31b, 31c) being inserted into the lead holes (21a, 21b, 21c) of the substrate 20, and the leads of the magnetic detection element 30 are The predetermined pitch P is formed without being expanded in the arrangement direction and is inserted and mounted on the substrate 20. Here, the predetermined pitch P is an IC lead pitch P in which SIP type ICs are arranged before forming.

The conductor 10 is, for example, a bus bar, and generates a magnetic flux around when a current flows.

The substrate 20 is a printed wiring board (PCB) such as epoxy or glass epoxy. The substrate 20 is formed with necessary wiring patterns on the front surface and the back surface, and lead holes for inserting leads of electronic components such as the magnetic detection element 30 and fixing them by soldering. When the lead holes are formed as through holes that electrically connect the wiring patterns on the front and back surfaces, the lead holes are formed at arbitrary intervals. However, as lead holes into which the leads of SIP-type electronic components are inserted, Are formed at a predetermined pitch. Usually, the predetermined pitch P is often set to an interval of 2.54 mm (nominal value) as the lead interval of the SIP type electronic component. Therefore, when the lead of the electronic component is used without forming, the lead hole pitch formed in the substrate 20 is formed at an interval of 2.54 mm.

The magnetic detection element 30 has a magnetoelectric conversion part (magnetic sensor chip), a signal amplification part, a lead frame, etc. inside, is molded with resin or ceramic, and is packaged. The integrated leads are exposed outside the package. In the present embodiment, it is a SIP (Single Inline Package) type magnetic detection element in which a plurality of leads exposed outside the package are arranged in a line at a predetermined pitch. The plurality of leads are set, for example, at a predetermined pitch P and an interval of 2.54 mm (nominal value). As the magnetoelectric conversion unit, a Hall element that outputs an output value based on the magnetic flux density, a magnetoresistive element (MR element) that outputs an output value based on a change in the direction of the magnetic flux density, or the like is used. Can do. In the present embodiment, a Hall element is used.

(Arrangement of current detection device)
As shown in FIGS. 1 and 2, the conductor 10 generates a magnetic flux (magnetic flux density) B around the conductor 10 in accordance with Ampere's right-handed screw law. Note that the magnetic flux is generated concentrically around the conductor 10, but in the figure, one magnetic flux is shown as a representative.

The current detection device 1 measures the current I flowing through the conductor 10 by detecting the magnetic flux (magnetic flux density) B of this magnetic field. The magnetic detection element 30 is arranged so as to intersect with the magnetic flux (magnetic flux density) B in a state where the

leads

31a, 31b, 31c are inserted and mounted on the substrate 20. Therefore, in the current detection device 1, the magnetoelectric conversion unit inside outputs a detection value proportional to the magnetic flux (magnetic flux density) B, and the area where the magnetic flux is linked with the

leads

31 a, 31 b, 31 c or between the leads and Depending on the value of magnetic flux (magnetic flux density) B, it is affected by noise generated by current I.

(Lead forming)
3A is a front view showing the SIP-type magnetic sensing element formed with three leads, FIG. 3B is a right side view as seen from the direction C in FIG. 3A, and FIG. 3C is from the direction D in FIG. 3B. FIG.

In the magnetic detection element 30, three leads (31a, 31b, 31c) are arranged in a line and the pitch between the leads is a constant value P. As shown in FIG. 3B, the middle lead 31b is not expanded in the arrangement direction, but is bent and formed in a direction substantially orthogonal to the arrangement direction. Thereby, the leading end side of the lead can be formed corresponding to the lead holes 21 a, 21 b, 21 c of the substrate 20.

As shown in FIG. 3C, the lead interval is expanded to L by forming the middle lead 31b in a direction substantially orthogonal to the arrangement direction. The formed lead interval L> predetermined pitch P. As a result, the lead interval increases, so that short-circuit defects in the soldering operation can be reduced.

FIG. 4A is a front view showing a SIP type magnetic detection element having four leads, and FIG. 4B is a front view showing the SIP type magnetic detection element in a formed state.

In the magnetic detection element 35, four leads are arranged in a row and the pitch between the leads is a constant value P. In FIG. 4A, the lead 35c is, for example, a test pin, and when three

leads

35a, 35b, and 35d are mounted and used on the substrate, the tip side of the lead 35c is cut off, and the lead 35b The distal end side 35e is bent in the shape of a crank toward the lead 35c and is formed. Thereby, the leading end side of the lead can be formed corresponding to the

lead holes

22a, 22b, 22d of the substrate 20.

As shown in FIG. 4B, forming is performed by bending the leading end side of the leads in the arrangement direction without expanding the predetermined pitch P of the leads in the arrangement direction. In this formed state, the interval between the lead 35a and the lead 35b is P, and the interval between the lead 35b and the lead 35d is L. The formed lead interval L> predetermined pitch P. Here, if 3P> 2L, the area where the magnetic flux links does not increase.

5A is a front view showing the inter-lead or lead and flux B is interlinked area S ₁ in SIP type magnetic sensor in a state of being forming includes three leads, Figure 5B is provided with four lead between the leads or lead in SIP magnetic sensing element forming state and the magnetic flux B is a front view showing an interlinkage area S _2.

As shown in FIG. 5A, the SIP type magnetic sensing element 30 having the three leads in the formed state shown in FIG. 3A is inserted into the

lead holes

21a, 21b, 21c of the substrate 20. It is fixed with solder 40. When arranged at a position interlinking with the magnetic flux B shown in FIGS. 1 and 2, the hatched area in FIG. 5A is an area S ₁ where the magnetic flux B interlinks with the leads or between the leads. Forming is not spread a certain pitch in the arrangement direction, since the forming in a direction substantially orthogonal to the array direction, interlinked area S ₁ is the same as when not forming. That is, since the area where the magnetic flux intersects with the leads or between the leads does not increase, the noise performance does not deteriorate.

Further, as shown in FIG. 5B, the SIP type magnetic sensing element 35 having four leads in the formed state shown in FIG. 4B is inserted into the

lead holes

22a, 22b, 22d of the substrate 20. And fixed with solder 40. When placed in the indicated flux B and chains interlinked that position in FIGS. 1 and 2, a region indicated by hatching in FIG. 5B, between the lead or leads and the magnetic flux B is interlinked area S _2. Forming is not spread a certain pitch in the arrangement direction, since by bending the front end side of the lead 35b to the lead 35c side are forming, it interlinks area S ₂ is the same as when not forming. That is, since the area where the magnetic flux intersects with the leads or between the leads does not increase, the noise performance does not deteriorate.

FIG. 6 is a relationship diagram illustrating the relationship between area × magnetic flux and transient characteristic noise peak value. FIG. 7 is a waveform diagram showing the correspondence between the input current and the output voltage of the magnetic detection element that detects the magnetic flux generated by this input current.

As shown in FIG. 6, the interlinked area × magnetic flux (magnetic flux density) and the transient characteristic noise peak value are in a substantially proportional relationship. The interlinked area × magnetic flux and the transient characteristic noise peak value are both normalized with a certain value of 1. In the present embodiment, as shown in FIG. 6, five types of interlinked areas × magnetic fluxes are obtained, and the noise peak values in the transient characteristics are measured and plotted for each. As a result, if the positional relationship between the conductor 10 and the magnetic detection element is constant, the lead or the area where the magnetic flux B interlinks between the leads and the noise peak value in the transient characteristics are proportional. Therefore, as in this embodiment, if the forming does not spread the leads in the arrangement direction, the noise performance is not deteriorated.

FIG. 7 shows a current waveform when a current of 100 A rises within Δt (1 μs) and an output voltage of the current detection device 1 that detects this current as a voltage change based on a change in the magnetic field. The noise performance in the transient characteristic is represented by ΔVh / Vh by dI / dt.

The magnetic flux (magnetic flux density) shown in FIG. 6 is proportional to ΔVh / Vh by dI / dt. Since this magnetic flux (magnetic flux density) depends on the object to be measured, it is necessary not to increase the interlinking area in order not to reduce the noise performance due to dI / dt as the current detection device 1.

(Effect of the embodiment of the present invention)
From the above, the current detection device 1 according to the embodiment of the present invention has the following effects.
(1) The current detection device 1 according to the present embodiment performs lead forming without expanding the predetermined pitch P of the SIP type IC (SIP type magnetic detection element) in the arrangement direction. Thereby, the area where the magnetic flux based on the lead or between the leads and the current flowing through the conductor 10 is linked does not increase, and the noise performance does not deteriorate.
(2) When forming a plurality of leads without excision or the like, the leads are bent in a direction substantially orthogonal to the arrangement direction, without forming the leads in the arrangement direction. As a result, the lead interval can be expanded without increasing the area where the magnetic flux links, and short-circuit defects in the soldering operation can be reduced.
(3) If some of the leads of the plurality of leads can be excised, forming is performed by bending (for example, bending in a crank shape) the lead side of the lead. As a result, the lead interval can be expanded without increasing the area where the magnetic flux links, and short-circuit defects in the soldering operation can be reduced.
(4) Generally, the predetermined pitch P of the SIP type IC (SIP type magnetic detection element) is, for example, 2.54 mm (1/10 inch). On the other hand, as an in-house standard, there is a case where the lead hole interval of the board is defined in order to prevent a short circuit in the soldering operation. Even in such a case, according to the present embodiment, it is possible to reduce short-circuit defects and maintain noise performance.

The present invention can be applied to a drive motor used in a hybrid vehicle or an electric vehicle and a current detection device having a magnetic detection element for detecting a current flowing in a battery.

DESCRIPTION OF SYMBOLS 1 Current detection apparatus 10 Conductor 20 Board | substrate 30

Magnetic detection element

31a, 31b,

31c Lead

35a, 35b, 35c, 35d Lead

Claims

A substrate disposed in the vicinity of a conductor that generates a magnetic flux around when current flows;
A plurality of leads arranged at a predetermined pitch, and a SIP type magnetic sensing element mounted with the leads inserted into the substrate,
The current detection device, wherein the leads of the magnetic detection element are formed without extending the predetermined pitch in the arrangement direction and are inserted and mounted on the substrate.
The current detection device according to claim 1, wherein the magnetic detection element is formed in a direction in which the leads intersect the arrangement direction.
The current detection device according to claim 1, wherein the magnetic detection element is formed such that a tip end side of the lead corresponds to a lead hole of the substrate.
The current detection device according to any one of claims 1 to 3, wherein the magnetic detection element is formed and mounted so that an area where the magnetic flux links with the leads or between the leads does not increase.
The current detection device according to any one of claims 1 to 4, wherein the magnetic detection element is arranged such that an extending direction of the conductor is orthogonal to the arrangement direction of the leads.
The current detection device according to any one of claims 1 to 5, wherein the forming is performed such that a pitch (L) between the leads after the forming exceeds the predetermined pitch (P).
The current detection device according to any one of claims 1 to 6, wherein the conductor includes a bus bar.