JPS6180074A - Magnetic sensor with terminal for detecting current - Google Patents

Abstract

PURPOSE:To improve magnetic detection sensitivity by increasing the magnetic flux density applied to a magnetism-sensitive chip while shortening the distance from a metal conductor to the position of the magnetism-sensitive chip, by constituting the titled sensor so that the magnetism-sensitive chip is fixed to the metal conductor directly or through an insulating film. CONSTITUTION:An operation layer 22 and four electrode regions are provided to a part of the surface of the semiconductor substrate of a magnetism-sensitive chip 11 and the substrate 21 is fixed to the central part of a metal conductor 10 by an adhesive. Lead frame 12-15 are connected to two pairs of four electrode terminals provided to the chip 11 on two axes crossing at right angles to each other at respective one end parts thereof through bonding wires 16. The one terminal parts of the chip 11 and the lead frames 12-15 and the central part of the metal conductor 10 are sealed by a resin 17. Both terminal parts 10a, 10b of the metal conductor 10 are current detection terminals and two of the other terminal parts of the lead frames 12-15 are used as current applying terminals while the remainder two as voltage outputtake-out terminals.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a magnetoelectric transducer, and more particularly to a current detection magnetic sensor that senses magnetic flux generated by a current flowing through a metal conductor.

[Technical background of the invention]

Generally, as a magnetic sensor for magnetoelectric conversion, a Hall sensor (including a Hall IC alone or a Hall IC with a built-in amplification function) that utilizes the Hall effect together with a magnetoresistive element, a magnetic diode, a magnetic transistor, etc. is known. It is possible to sense the magnetic flux generated by a current flowing through a metal conductor using such a magnetic sensor.
．． For example, a Hall sensor 3 is attached as a magnetically sensitive sensor to a part of the surface of 2 to detect current. This Hall sensor 3 is mounted on any one of the four lead frames 4 (2111 is for passing current through the semiconductor thin piece, and the remaining two are for taking out voltage output). A magnetically sensitive chip (semiconductor chip) 5 is fixed to the above-mentioned four IJ-deframes 4.
The chip 5 and one end of each lead frame 4 are sealed with resin 6 or the like, and the other end of each lead frame 4 serves as an external terminal.

[Problems with background technology]

By the way, in the above current detection method, the magnetically sensitive chip 5
The magnetic flux density applied to is the distance 4d from the center point of the metal conductor 2
is inversely proportional to. However, the magnetic flux density is greatly affected by the distance d' from the magnetic sensitive chip 5 to the magnetic sensor surface in the magnetic sensor 3, and the magnetic flux density becomes small, so that the detection sensitivity of the magnetic sensor 3 is low and good. There was a problem that current detection was difficult.

[Object of the Invention] The present invention has been made in view of the above circumstances, and the distance from the magnetic flux generation site of the metal conductor for current jetting to the magnetically sensitive tip position is short, and the magnetic flux density applied to the magnetically sensitive tip is reduced. The present invention provides a magnetic sensor with a current detection terminal that has a large magnetic detection sensitivity and has a good magnetic detection sensitivity.

[Summary of the invention]

The device is characterized in that it has a current detection terminal consisting of an end portion, and a magnetically sensitive chip is fixed to the metal conductor directly or via an insulating film inside the sealing portion.

Therefore, the distance from the metal conductor to the magnetically sensitive chip position is short, the magnetic flux density applied to the magnetically sensitive chip is high, and the magnetic detection sensitivity is improved.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings. In FIGS. 1(a) and 1(b), reference numeral 10 denotes a metal conductor for current detection (energization), which is, for example, a strip-shaped plate. Reference numeral 11 denotes a magnetically sensitive chip, for example, as shown in FIG. Layer (NGaA+s layer) 2
2 and 4 electrode regions (only 2 @ 23 and 24 are shown) are provided, and the substrate 21 is adhesively fixed to the center of the metal conductor 10 by, for example, an adhesive 18. . In addition, 25 is an insulating film, 2.

24 is an electrode contact portion. On the other hand, 12 to 15 are lead frames for Hall sensors, each of which has one end connected to a pair of electrode terminals, each of which is connected to a total of four electrode terminals on two orthogonal axes on the Hall sensor chip 1. 16. One end of each of the lead frames 12 to 15 and the center of the metal conductor 10 of the chip 11.4@ are sealed with, for example, resin 17 to form a Hall sensor with a current detection terminal. In this case, both ends 10* and 10b of the metal conductor 100 protruding to the outside of the resin 17 are used for current detection (current conduction).
It becomes a terminal and 4f[i! I lead frame 12-15
Among the other ends, 2@ (for example, 12.14) is a current application terminal, and the remaining F)2t@C1s, 1s) are voltage output terminals.

In the Hall sensor with the current detection terminal configured as described above, when the Hall sensor tip 11 senses the magnetic flux that is often generated when a current is passed through the metal conductor 10, the operating layer 22 of the sensor chip 1 starts from the magnetic flux generation site. Since the distance to the sensor chip 11 is extremely small compared to the conventional example in which a resin portion exists, the magnetic flux density applied to the sensor chip 11 is large, and the magnetic detection sensitivity of the sensor chip 11 is good.

Depending on the type of sensor chip, if it is directly bonded to the metal conductor 10 with the adhesive 18, it may not be possible to maintain electrical insulation from the metal conductor 10. In this case, as shown in FIG. A thin insulating film 19 is provided on the sensor chip fixing portion 10, and the sensor chip fil is fixed onto this insulating film 19 using an adhesive 18.

Note that the shape of the current jetting metal conductor IQ is not limited to the above example, and as shown in FIG.
1 may be used, as shown in FIG. 4(b), the lengthwise central portion of the metal conductor 42 is formed into, for example, a semicircular loop shape, and the magnetic flux density is increased by this loop 7 portion 42c. The sensor chip may be provided at a large portion of the metal conductor 4 as shown in FIG. 4(C).
3 is formed into a loop for one tan, and this loop portion 43. Alternatively, the magnetic flux density may be further increased. Further, the metal conductors 10, 41, 42, 43 are not limited to a plate shape, and may have a circular cross-sectional shape, and may have a shape in which both ends thereof are aligned with each other without facing each other on a straight line. Further, the sensor chip is not limited to a Hall sensor chip, but may be a magnetoresistive element or the like.

〔Effect of the invention〕

As described above, according to the magnetic sensor with a current detection terminal of the present invention, a magnetically sensitive chip is fixed to a metal conductor for current detection,
Since the fixed portion is sealed, the distance from the metal conductor to the magnetically sensitive tip is short, the magnetic flux density applied to the magnetically sensitive tip is large, and the magnetic detection sensitivity is improved.

[Brief explanation of drawings]

Figures wc1 (&) and (b) show an embodiment of the magnetic sensor with a current detection terminal according to the present invention, and FIG. A sectional view showing an example of the Hall sensor chip in FIG. 1, FIG. 3 is a cross-sectional view showing a modified example of the chip fixing part, and FIGS. A perspective view showing a modified example of the metal conductor in the figure, FIGS. 5 and 6 (
-) is a perspective view showing a deaf person in which a conventional magnetic sensor is attached to a metal conductor for current detection, and Fig. 6(b) is a perspective view of the same figure (
, ) is a side view. 10.41.42.43... Metal conductor, 11... Hall sensor chip, 12-15... Lead frame,
17...Resin (sealing part) 10&, 10bT41a, 4
1b... Terminal part for current detection, 18... Adhesive, 19
...Insulating film. Applicant's representative Patent attorney Takehiko Suzue Figure 1 (a) (b) L J Figure 2 Figure 3 Figure 4 Figure 5 C

Claims (3)

[Claims] (1) A metal conductor for current detection, a magnetoelectric transducer chip fixed to a part other than both ends of the conductor, a plurality of lead frames each having one end connected to the chip, and each of the lead frames. For current detection, comprising one end and a sealing part that integrally seals the chip and the chip fixing part of the metal conductor, and having both ends of the metal conductor as external terminals for current detection. Magnetic sensor with terminal. (2) The magnetic sensor with a current detection terminal according to claim 1, wherein the chip is fixed to the metal conductor directly or with an adhesive through an insulating film. (3) The magnetic sensor with a current detection terminal according to claim 1, wherein the chip is a GaAs Hall sensor chip, and the sealing portion is made of resin.