JP4483760B2 - Current sensor - Google Patents

Description

The present invention relates to a current sensor that detects a current flowing in a current line including a current line to be detected in cooperation with the detection target, that is, a power source system such as an automobile brake, for example. the original magnetic detection by the magnetic sensing element (magnetoelectric conversion element), a current flowing through the current line (details amount of current, direction, etc.) related to a current sensor for detecting a.

  Conventionally, as this type of current sensor, a current sensor using a Hall element or a magnetoresistive element is well known. First, the principle of current detection by a current sensor using a Hall element will be described.

  As is well known, when magnetism (magnetic flux) is applied to the Hall element, a Hall voltage proportional to the strength of the applied magnetism is generated in the Hall element. On the other hand, when a current flows through a current line (current path), magnetism (magnetic field) proportional to the magnitude (current amount) of the flowing current is generated around the current line. In general, in a current sensor using a Hall element, under such a phenomenon, the proportional relationship between the current flowing in the current line and the magnetism generated due to this current, and the magnetism applied to the Hall element and this magnetism The current flowing through the current line to be detected (specifically, the amount and direction of the current) is detected by utilizing the proportional relationship with the Hall voltage generated along with the current. That is, in such a current sensor, by detecting the magnetism generated due to the current flowing through the detected current line as the Hall voltage, the current flowing from the detected magnetism to the detected current line can be detected. Is going.

  However, when performing such current detection, there is a proportional relationship between the magnetism applied to the Hall element and the Hall voltage generated by the magnetism in a region where the intensity of magnetism applied to the Hall element is small. It becomes difficult to maintain. In addition, in this region, since the intensity of the magnetism generated due to the current flowing through the current line is small in the first place, it is difficult to detect the current with high sensitivity only by the principle described above. Therefore, such a current sensor is usually provided with a core that collects the magnetism generated due to the current flowing through the detected current line, as in the sensor described in Patent Document 1 or Patent Document 2, for example. Thus, the intensity of magnetism applied to the Hall element as the magnetic detection element is increased. Hereinafter, with reference to FIG. 12, an outline of a current sensor having such a magnetism collecting core will be described.

  As shown in FIG. 12, this current sensor basically includes a core 4 and a Hall element made of a magnetic material for collecting magnetism generated due to a current If flowing in the current line 2 to be detected. (Strictly speaking, a Hall IC in which horizontal Hall elements are integrated) 1 is configured. Among these, the core 4 made of a magnetic material is formed in a substantially C shape, and surrounds the current line 2 to be detected in a central space. On the other hand, the Hall element 1 is disposed in a gap (space) formed between the opposing end surfaces of the core 4. Since the detected current line 2, the core 4 and the Hall element 1 are in such a positional relationship, in this sensor, the magnetism generated due to the current If flowing in the detected current line 2 is The core 4 collects and amplifies the magnet with a required strength, and this acts on the Hall element 1.

As described above, in this sensor, the magnetic intensity applied to the Hall element 1 is ensured to a required level, and even if the current If flowing through the detected current line 2 is a small current, The amount (size) can be detected appropriately. In addition, the amplifier circuit 3 (operational amplifier) provided for amplifying the output signal output from the Hall element 1 also actively enables more sensitive current detection.
JP 2002-303642 A JP-A-5-312839

  As described above, even with the conventional current sensor illustrated in FIG. 12, the current flowing through the current line to be detected can be detected with high sensitivity. However, in this conventional current sensor, it is essential to dispose the above-described core 4 in order to detect a small current, and it is inevitable that the sensor unit as a whole is increased in size and the number of parts. Moreover, accurate current detection is hindered by the influence of the magnetic material-specific properties such as hysteresis and magnetic saturation from the core 4 made of this magnetic material.

  In addition to this, as a current sensor, in order to increase the sensitivity of the sensor (increase the sensor output), a Hall element (horizontal Hall element) made of a compound semiconductor (for example, InAs) having a higher mobility than Si (silicon). ) Is known. However, when current detection is to be performed by such a current sensor, a circuit (for example, the amplifier circuit 3 in FIG. 12) that performs predetermined signal processing on the signal output from the Hall element is separated from the Hall element. It is necessary to provide it as a chip (IC). That is, even a current sensor using a Hall element made of such a compound semiconductor eventually leads to an increase in the number of parts and an increase in assembly cost.

  The present invention has been made in view of such circumstances, and an object thereof is to provide a current sensor that can maintain a simple structure and can detect a current with high sensitivity without increasing the number of components. .

In order to achieve such an object, according to the first and second aspects of the present invention, a semiconductor substrate having a plurality of vertical Hall elements and a current line disposed perpendicularly to the semiconductor substrate are provided, and the current line has a current. The semiconductor as a current sensor having a structure for detecting current flowing from the detected magnetism to the current line by detecting the magnetism generated due to the flow of current by the plurality of vertical Hall elements The substrate is provided with a space for guiding the current line to a magnetic detection position by the plurality of vertical Hall elements and allowing the current line to vibrate at the detection position. Each vertical output of the vertical Hall element is detected separately, and the vertical Hall element having the maximum output is specified to detect the vibration direction or position of the current line.

In recent years, vertical Hall elements that detect magnetism in a direction parallel to the substrate surface are separated from Hall elements that have been generally used in the past, that is, horizontal Hall elements that detect magnetism in a direction perpendicular to the substrate surface (chip surface). Research and development are also underway. The inventor has devised a current sensor having such a structure that is completely different from that of the prior art by using such a vertical Hall element. According to this current sensor, that is, according to the sensor structure described in claims 1 and 2, the semiconductor sensor includes a semiconductor substrate having a plurality of vertical Hall elements and a current line arranged perpendicular to the semiconductor substrate. Thus, without using the magnetic material (core) for collecting magnets described above , each output of the plurality of vertical Hall elements is detected separately, and the vertical Hall element having the maximum output is specified. position of the current line by the vibration direction of the current line, or where the output to identify the vertical Hall element having the maximum will be detected by. That is, a simpler structure is maintained, without increasing the number of components, it is possible to detect the vibration direction or position of the sensitive conductive streamlined.

When a plurality of (or many) Hall elements are arranged on the same substrate, a general horizontal Hall element detects a magnetism by flowing a drive current in a direction parallel to the substrate surface, so that a large area is formed on the substrate. Needed and not practical. In this respect, in the case of the above vertical Hall element, since a drive current flows in a direction perpendicular to the substrate surface, even when a plurality of them are arranged on the same substrate, the space restriction is eased and a simple structure is achieved. It becomes possible to maintain. In addition, since the direction of magnetism emitted from the detection target (current line) arranged perpendicular to the substrate is parallel to the substrate, all vertical Hall elements provided on the same substrate have this direction. It is possible to detect (magnetism) separately . That is, even the current flowing through the detection object (current line) is an example small current, depending on that the output of these vertical Hall element to identify the vertical Hall element having the maximum intensity of the magnetic The vibration direction or position of the current line can be appropriately detected from the change.

For Matako these, as by the invention of claim 3, said plurality of vertical Hall element, the around the magnetic detection position, arranged annularly said the semiconductor substrate (on the same substrate) it is Ru can.

Specifically, when a current flows through a current line to be detected, magnetism is emitted radially from the current line. The strength (magnetic flux density) of the magnetism generated here is inversely proportional to the square of the distance from the source (here, the current line), as is well known. Therefore, when the plurality of vertical Hall elements are arranged in an annular shape around the magnetic detection position as in the above-described structure according to claim 3 , by arranging a current line at the magnetic detection position , When there is no vibration or the like in the current line, magnetism with an equivalent strength is detected in all of the vertical Hall elements arranged in an annular shape .

Alternatively, as by the invention of claim 4, in the current sensor according to the claim 3, wherein the semiconductor substrate, employing those containing a pre-SL current line electrically Ku cut to the magnetic detection position, The plurality of vertical Hall elements arranged in an annular shape can be arranged so as to draw a circular trajectory on the semiconductor substrate in a manner that avoids this notch .

Further, in the current sensor described in claim 4, the pre-SL current line electrically Ku cut into the magnetic position detection, such as by the invention of claim 5, it is cut to the magnetic detection position It is valid. In this way, it becomes easier accurately directing that the previous SL current line to a predetermined detection position.

Also, here, when a space allowing the vibration of the current line is provided at the outer edge of the semiconductor substrate, the plurality of vertical Hall elements arranged in an annular shape, particularly according to the invention of claim 6, The semiconductor substrate may be arranged so as to draw a semicircular locus in the vicinity of the outer edge of the semiconductor substrate.
In addition, in this case, by arranging the semiconductor substrate on the left and right sides of the current line, the vertical type is drawn so as to draw a circle (one circle instead of a semicircle) around the current line.
It is also possible to arrange a Hall element.

On the other hand, according to the invention described in claim 7, in the current sensor according to claim 1 or 2 , the plurality of vertical Hall elements are arranged on the semiconductor substrate with the magnetic detection position as the center (the same If the current sensor is arranged so as to be continuous in parallel on the substrate, the current sensor is useful as a position sensor for detecting the position of the current line.

Specifically, as described above, the magnetic strength (magnetic flux density) is inversely proportional to the square of the distance from the generation source (current line). Therefore, a plurality of vertical Hall elements arranged such that the parallel continuous around the said magnetic position detection, the output of the closest vertical Hall element to the current line becomes the maximum, as the distance from the current line, The output of the vertical Hall element is small. Therefore, according to the sensor of claim 7, when the current line is moved (position change) in the arrangement direction of these vertical Hall element (direction successive parallel), the movement (vibration and inclination, etc. ) and Hiite the vibration direction and position of the current line, based on an output change of each vertical Hall element that corresponds to the position change of the electric flow line, it is possible to accurately detect.

Or alternatively, as by the invention of claim 8, in the current sensor according to the claim 7, employing those Examples semiconductor substrate, containing the pre-SL current line cuts, such as leading to the magnetic detection position It is more preferable that the plurality of vertical Hall elements are arranged on both sides of the cut so as to be continuous in parallel.

According to this structure, by disposing the current line to the magnetic detection position more directed to the notch above as described above, so that the position detection before the SL current line can be easily performed. Moreover in this case, only a single semiconductor substrate, on both sides of the current line, it is possible to arrange the vertical Hall element as continuous parallel together.

Also in this case, in the invention described in any one of claims 4, 5 or 8, such as by a current sensor according to claim 9, you to provide a pre-Symbol cuts itself in the vertical direction.
Usually, moving vehicles such as automobiles and motorcycles generate vertical (vertical) vibration during movement. For this reason, when the current sensor is mounted on a moving vehicle, there are concerns about disconnection of wiring (current lines) and disconnection (disconnection) of various boards (printed circuit boards) mounted on the vehicle. Will come to be. Therefore, if the current sensor is adopted, it becomes possible to detect the up / down (vertical direction) fluctuation (the position of the current line) of the current line through the space (cut), and thus the disconnection of the wiring. And connector disconnection can be prevented in advance. Note that the sensor installation environment is not limited to this, and when the current sensor is used for detecting vibrations other than the moving vehicle, the same effect or an equivalent effect can be obtained. .
Furthermore, when detecting the position of the same current line, the plurality of vertical Hall elements are configured such that their outputs are detected separately, so that each of the vertical Hall elements detected individually can be detected. Based on the change in output, it becomes possible to detect the position of the current line with high accuracy more easily and accurately.

Further, with respect to a current sensor according to claim 7, such as by the invention of claim 10, wherein the space is the result provided in the vertical direction of the outer edge of the semiconductor substrate, positioned so that the parallel continuous It is more desirable to arrange a plurality of vertical Hall elements in the vicinity of the outer edge of the semiconductor substrate. According to such a structure, by arranging the current line on the side of the semiconductor substrate, it becomes possible to easily detect the vibration direction and position of the current line as described above. In addition, in this case, by arranging the semiconductor substrate on the left and right sides of the current line, it is possible to arrange vertical Hall elements that are continuous in parallel on both sides of the current line .
By adopting the current sensor in this way as well, it becomes possible to detect the up and down (vertical direction) fluctuation (current line position) of the current line through the space. Omission etc. can be prevented beforehand.
Furthermore, by configuring the plurality of vertical Hall elements so that their outputs are detected separately, as described above, it is also possible to detect the position of the current line with high accuracy.

In order to maintain a simple structure, the current sensor according to any one of claims 1 to 10 adopts a substrate made of silicon as the semiconductor substrate, as in the invention according to claim 11. and, in the same substrate, in addition to the plurality of vertical Hall element, said plurality of vertical Hall element performs predetermined signal processing on the signal output from the circuit (e.g. an amplifier circuit, or the offset and temperature characteristics It is effective to have a structure in which correction circuits and the like for correction are also integrated. As described above, when such a processing circuit is provided as a separate chip, the number of components is increased and the assembly cost is increased. That is, in order to simplify the structure, it is desirable to integrate these processing circuits together with the plurality of vertical Hall elements on the same chip.

(First comparative example )
A first comparative example will be described below with reference to FIGS. 1 and 2 prior to description of an embodiment in which a current sensor according to the present invention is embodied.

FIG. 1 is a perspective view schematically showing the outline (schematic structure) of this current sensor.
As shown in FIG. 1, this current sensor basically includes a semiconductor substrate 10 made of, for example, silicon. At a detection position A (the center of the substrate 10) of the semiconductor substrate 10, a detected current line 12 made of, for example, a wiring provided in a power supply system such as an automobile brake is perpendicular to the substrate 10. Are arranged (fixed) to each other (so as to be orthogonal). On the semiconductor substrate 10, a plurality of (here, seven) vertical Hall elements 11 are arranged in an annular shape, specifically, so as to draw a circular locus centering on the current line 12. A cut CT that guides the current line 12 to be detected to the detection position A is provided to the semiconductor substrate 10 as a cut to the detection position A, so that the current line 12 is highly assembled. Is secured.

  The output terminals of the plural (seven) vertical Hall elements 11 are electrically connected to each other in series. Although illustration is omitted for convenience, the semiconductor substrate 10 is subjected to predetermined signal processing on the signals output from the vertical Hall elements 11 in addition to the vertical Hall elements 11. A circuit (for example, an amplifier circuit or a correction circuit that corrects offset and temperature characteristics) is further integrated.

  FIG. 2 is a diagram schematically showing a schematic structure of an example of a vertical Hall element used in the current sensor. 2A is a plan view of the Hall element, FIG. 2B is a cross-sectional view taken along line L1-L1 in FIG. 2A, and FIG. 2C is a line L2-L2 in FIG. FIG.

  As shown in FIG. 2, the Hall element includes a semiconductor layer (P-sub) 21 made of, for example, P-type silicon, and a buried layer formed by introducing N-type conductive impurities into the surface. The buried layer BL is further provided with a semiconductor region 22 made of, for example, N-type silicon formed by epitaxial growth. The buried layer BL functions as a lower electrode, and its impurity concentration is set higher than that of the semiconductor region 22.

Further, in the semiconductor region 22, for example, a P-type diffusion layer (separation wall) 24 that is connected to the semiconductor layer 21 is formed so as to isolate the Hall element from other elements. Further, in the region (active region) surrounded by the diffusion layer 24 on the surface of the region 22, the contact region (N ⁺ diffusion layer is formed in such a manner that the impurity concentration (N type) on the surface is selectively increased. ) 23a to 23d are formed. And by providing an electrode (wiring) in each of these regions, the regions 23a to 23d are electrically connected to the terminals S and G and V1 and V2, respectively.

  A region (active region) surrounded by the diffusion layer 24 is divided into regions 22 a and 22 b that separate the diffusion layer 25 through pn junction isolation of a P-type diffusion layer (separation wall) 25. These regions 22a and 22b are also electrically partitioned inside the substrate, and are regions defined by the contact regions 23c and 23d in the partitioned regions (indicated by a one-dot chain line in FIG. 2). A region) corresponds to a so-called magnetic detection unit (Hall plate) HP in the Hall element. That is, this Hall element outputs a Hall voltage signal corresponding to the magnetic field applied here (magnetic detection unit).

When operating such a Hall element, first, for example, a constant drive current is supplied from the terminal S to the terminal G. Then, the current flows from the contact region 23a formed on the substrate surface to the contact region 23b through the magnetic detection part HP and the buried layer BL. That is, in this case, a current mainly including a component perpendicular to the substrate surface (chip surface) flows through the magnetic detection unit HP. For this reason, in the state where this driving current is applied, a magnetic field (for example, a magnetic field indicated by an arrow B in FIG. 2) including a component parallel to the substrate surface (chip surface) is applied to the magnetic detection unit HP of the Hall element. Then, a Hall voltage corresponding to the magnetic field is generated between the terminal V1 and the terminal V2 due to the Hall effect. Therefore, by detecting the generated Hall voltage signal through these terminals (output terminals) V1 and V2, the well-known relational expression “V _H = (R _H IB / d) cos θ” (V _H : Hall voltage, R _H Is the Hall coefficient, I is the drive current, B is the magnetic flux density, d is the thickness of the magnetic detector, and θ is the incident angle of the magnetic field), that is, the surface of the substrate used for the Hall element. A magnetic field component parallel to the (chip surface) is required. Incidentally, in this Hall element, the dimension d shown in FIG. 2A corresponds to “d” in the above relational expression. In addition, the direction in which the drive current flows in the Hall element is arbitrary, and the magnetic field (magnetism) can be detected by reversing the direction of the drive current.

Next, the operation of this sensor will be described.
That is, in such a current sensor, when a current flows through the current line 12 to be detected, the magnetism generated due to this acts on all of the plurality (seven) vertical Hall elements 11. Then, the magnetism generated in this way is detected by these vertical Hall elements 11, and the current (specifically, the amount and direction of the current) flowing through the current line 12 from the detected magnetism is detected.

  Further, in this sensor, since the output terminals of these vertical Hall elements 11 are electrically connected in series, the outputs of these vertical Hall elements 11 are added, and the intensity (magnitude) of the detection signal is added. Will be substantially increased. Furthermore, providing an amplification circuit (not shown) as a circuit for amplifying the detection signal also increases the current detection sensitivity of the sensor. Thus, even if the current flowing through the current line 12 is a small current, this sensor can appropriately detect the current (specifically, the current amount and direction).

According to the current sensor according to the comparative example described above, the following effects can be obtained.
(1) A semiconductor substrate 10 having seven vertical Hall elements 11 is provided as a current sensor for detecting a current flowing through a current line 12 to be detected, and a current is supplied to the current line 12 arranged perpendicular to the substrate 10. By detecting the magnetism generated due to the current flowing by the vertical Hall element 11, the current flowing through the current line 12 from the detected magnetism is detected. As a result, the current flowing through the current line 12 is detected based on the magnetism detected by the vertical Hall element 11, a simple structure is maintained, and high sensitivity is achieved without increasing the number of parts. Current detection is possible.

  (2) By providing a plurality (seven) of the vertical Hall elements 11, specifically, by connecting the output terminals of the vertical Hall elements 11 in series electrically, Even if the current flowing through the (current line 12) is a small current, the amount and direction of the current can be appropriately detected through the vertical Hall element 11.

  (3) By arranging a plurality (seven) of the vertical Hall elements 11 in an annular shape, the vertical Hall elements 11 arranged in an annular shape by the magnetism generated from the current line 12 disposed in the center of the ring. For all (all seven), magnetism having the same strength is applied. That is, by using each output (equivalent output) of these vertical Hall elements 11, specifically, for example, by applying various operations (here, addition) to this, the intensity (magnitude) of the detection signal As a result, the sensitivity of the current sensor can be improved.

  (4) The semiconductor substrate 10 is provided with a cut CT that guides the current line 12 to the detection position A. For this reason, high assemblability of the current line 12 to be detected is ensured through the cut CT, and the current sensor can be easily provided by arranging the current line 12 at the detection position A guided by the cut CT. As a result, the sensitivity can be improved. In addition, in this case, the vertical Hall element 11 is arranged so as to draw a circle (one circle instead of a semicircle) around the current line 12 to be detected by only one semiconductor substrate 10. It becomes possible to do.

(5) Moreover, since the cut CT is cut to the detection position A, it is easier to accurately position the current line 12 to be detected to the predetermined detection position A.
(6) A substrate made of silicon is employed as the semiconductor substrate 10, and the substrate 10 is subjected to predetermined signal processing on signals output from the vertical Hall element 11 in addition to the vertical Hall element 11. A circuit (for example, an amplifier circuit or a correction circuit for correcting offset and temperature characteristics) is also integrated. As described above, when such a processing circuit is provided as a separate chip, the number of components is increased and the assembly cost is increased. That is, in order to simplify the structure, it is desirable to integrate such a processing circuit on the same chip together with the vertical Hall element 11.

  Note that the number of the vertical Hall elements 11 provided on the semiconductor substrate 10 is not limited to seven and is arbitrary. For example, as shown in FIG. 3, a large number of vertical Hall elements 11 may be provided radially (annularly). Alternatively, as shown in FIG. 4, three vertical Hall elements 11 can be provided vertically and horizontally (annularly). In a more extreme case, one is enough. In order to increase the sensor output, it is desirable to increase the number of the vertical Hall elements 11. On the other hand, it is desirable to reduce this number in order to simplify the structure and reduce the size (reduction of the chip area, etc.).

(Second comparative example )
Next, referring to FIG. 5, a description will be given of a second comparative example.

FIG. 5 is a perspective view schematically showing an outline (schematic structure) of the current sensor.
As shown in FIG. 5, this current sensor also has a structure similar to that of the sensor of the first comparative example . However, in this sensor, the cut CT (FIG. 1) is not formed, and a plurality (here, three) vertical Hall elements 11 draw a semicircular locus in the vicinity of the outer peripheral edge of the semiconductor substrate 10. Has been placed. The current line 12 to be detected is disposed at the side (detection position A) of the semiconductor substrate 10 and at the center of the ring (semicircle).

That is, above according to the current sensor according to the comparative example described, in addition to the effect similar to the effect or effects analogous thereto of the of the first comparative example (1) to (3) and (6), the following additional Such an effect can be obtained.

  (7) A plurality (three in this case) of the vertical Hall elements 11 are arranged so as to draw a semicircular locus in the vicinity of the outer peripheral edge of the semiconductor substrate 10. Thereby, even if it does not perform the special process for providing a cut etc. with respect to a board | substrate, ie, only the manufacturing method of general IC (integrated circuit), the high assembly property of the current line 12 used as a detection object is high. Will be secured. Further, by providing the current line 12 at the center (detection position A) of the ring (semicircle), the sensitivity as a current sensor can be easily improved.

  Also in this case, the number of the vertical Hall elements 11 disposed on the semiconductor substrate 10 is not limited to three and is arbitrary. That is, for example, as shown in FIG. 6, a large number of vertical Hall elements 11 may be provided radially (annularly).

  Further, by arranging the semiconductor substrate 10 on the left and right sides of the current line 12 to be detected, a circle (one circle instead of a semicircle) -shaped locus centering on the current line 12 is drawn. It is also possible to arrange the vertical Hall element 11 in the above. That is, by using the two semiconductor substrates 10 in this way, it is possible to further increase the sensitivity as a current sensor.

(First Embodiment)
Next, a first embodiment in which the current sensor according to the present invention is embodied will be described with reference to FIG. In this sensor, for example, mounted on a vehicle for movement (such as automobiles and motorcycles), as a position sensor for detecting (especially a vibration sensor for detecting vibration based on the position) and the position based on the current in the current line To work .

  FIG. 7 is a perspective view schematically showing an outline (schematic structure) of the current sensor. Note that the vertical direction in the figure (the direction indicated by the solid arrow in the figure) corresponds to the vertical direction when the sensor is mounted on a moving vehicle.

As shown in FIG. 7, this current sensor has a structure similar to that of the sensor of the first comparative example . However, in this sensor, a cut CT extending in the vibration direction (vertical bidirectional) at the detection position A corresponding to the center of the substrate is provided as a cavity having a spatial margin in the vibration direction. In addition, on the semiconductor substrate 10 and on both sides of the cut CT, a plurality of (here, ten) vertical Hall elements 11 are arranged so as to be continuous in parallel. Under such a structure, the detection target (current line 12) in this sensor is guided to the center of these continuous vertical Hall elements 11, that is, the detection position A through the cut CT. .

Here, in addition to the vertical Hall element 11, the signal processing circuit for the output of the element is also integrated on the semiconductor substrate 10 in the same manner as the sensor of the first comparative example . (Not shown). However, in this sensor, each output of the plurality (10 pieces) of the vertical Hall elements 11 is not connected in series but is detected separately.

Next, the operation of this sensor will be described.
As is well known, the magnetic strength (magnetic flux density) is inversely proportional to the square of the distance from the source (current line 12). Therefore, the plurality of (10) vertical Hall elements 11 arranged so as to be continuous in parallel have the maximum output of the vertical Hall element 11 closest to the current line 12 (detection target), and the same current line 12 The further away from it, the smaller the output of the vertical Hall element 11. In this sensor, based on such a phenomenon, the position of the current line 12 is detected based on a current value in the current line 12 (strictly speaking, a change in the current value). Specifically, in this sensor, when the current line 12 moves (changes in position) in the arrangement direction of the vertical Hall element 11 (the extending direction of the incision CT), the movement (vibration) and, consequently, the current line 12 positions are detected based on the output change of each vertical Hall element 11 corresponding to the position change of the current line 12.

According to the current sensor according to this embodiment described above, in addition to the effects similar to the effects (1) and (6) of the first comparative example or the effects similar thereto, the following effects are also obtained. It will be obtained.

  (8) A plurality of (here, ten) vertical Hall elements 11 are arranged so as to be continuous in parallel on the semiconductor substrate 10 (on the same substrate). Such a sensor is particularly useful when used as a position sensor for detecting the position of the current line 12. By using this as a position sensor, the current line 12 can be changed based on changes in the outputs of the vertical Hall element 11. The position can be detected with high accuracy.

(9) A cut CT for guiding the current line 12 to the detection position A is provided in the semiconductor substrate 10, and the vertical Hall element 11 is arranged on both sides of the cut CT so as to be continuous in parallel. did. For this reason, high positioning of the current line 12 to be detected is ensured through the cut CT, and the current line 12 is easily disposed as the current sensor at the detection position A guided by the cut CT. The sensitivity can be improved. Moreover, in this case, it is possible to arrange the vertical Hall elements 11 that are continuous in parallel on both sides of the current line 12 (detection target) with only one semiconductor substrate 10.

  (10) Further, the notch CT provides a spatial margin in the vibration direction (vertical direction) of the detection position (a margin that does not hit even if the current line 12 vibrates), so that a predetermined vibration direction ( The vibration detection in the vertical direction) is also preferably performed. In other words, it is possible to detect wiring disconnection and connector disconnection (disconnection), etc., which are a concern due to vibration in a moving vehicle, and to detect this with high accuracy and to recover or prevent it in advance. become.

  (11) Further, since the cut CT itself is a cavity extending in the vibration direction (vertical direction) of the detection position A (a cavity having a spatial margin in the vibration direction), the cutting CT can be processed more easily. This cavity can be easily formed.

Also in this case, the number of the vertical Hall elements 11 disposed on the semiconductor substrate 10 is not limited to ten and is arbitrary.
(Second Embodiment)
Next, a second embodiment in which the current sensor according to the present invention is embodied will be described with reference to FIG.

FIG. 8 is a perspective view schematically showing the outline (schematic structure) of this current sensor.
As shown in FIG. 8, this current sensor also has a structure similar to that of the sensor of the first embodiment. However, in this sensor, the cut CT (FIG. 7) is not formed, and a plurality (here, five) of the vertical Hall elements 11 are arranged in parallel near the outer edge of the semiconductor substrate 10. . The current line 12 to be detected is disposed at the side of the semiconductor substrate 10 and at the center of the continuous vertical Hall element 11 (detection position A).

That is, according to the current sensor according to this embodiment described above, the same effects as the effects (1) and (6) and (8) according to the first comparative example and the first embodiment, or In addition to the similar effects, the following effects can be obtained.

(12) A plurality of (here, five) vertical Hall elements 11 are arranged in parallel near the outer edge of the semiconductor substrate 10 in parallel. Thereby, even if it does not perform the special process for providing a cut etc. with respect to a board | substrate, ie, only the manufacturing method of general IC (integrated circuit), the high assembly property of the current line 12 used as a detection object is high. Will be secured. Further, by providing the current line 12 on the side of the substrate 10 (detection position A), the sensitivity as a current sensor can be easily improved.

Also in this case, the number of the vertical Hall elements 11 disposed on the semiconductor substrate 10 is not limited to five and is arbitrary.
Further, for example, as shown in FIG. 9, by arranging the semiconductor substrate 10 on the left and right sides of the current line 12 to be detected, both sides of the current line 12 are continuous in parallel. It is also possible to arrange the vertical Hall element 11. That is, by using the two semiconductor substrates 10 in this way, it is possible to further increase the sensitivity as a current sensor.

(Other embodiments)
Note that the comparative examples and the embodiments described above may be modified as follows.
In the first comparative example and the first embodiment, the structure in which the cut CT is cut into the substrate 10 is mentioned with emphasis on the assembling property of the current line 12, but the formation of the cut CT is essential. Not that. As long as a cavity (hole) is provided at the detection position A, the current line 12 can be assembled, and the function as a current sensor is appropriately maintained.

- the sensor of the first and second comparative examples, for example, mounted on a vehicle for movement, can you to detect vibrations in a predetermined direction (e.g., vertical direction). However, in this case, for example, as shown in FIG. 10 (here, the sensor of the first comparative example is illustrated), a cavity (in the vertical direction) of the detection position A where the detected current line 12 is installed ( A space) is provided, and a spatial margin (a margin that does not hit the current line 12 even when the current line 12 vibrates) is provided in the vibration direction. In this sensor, since the vertical Hall elements 11 are arranged in a ring shape (radially), two-dimensional (two-direction) position detection is possible.

  In addition, when detecting the vibration in the predetermined direction, the detection range can be arbitrarily set. For example, it is possible to detect a wide range of vibrations in the vicinity of the sensor installation location. However, if only disconnection of the current line 12 or disconnection (disconnection) of the current line 12 is detected, this can be detected with extremely high accuracy. Become.

- Furthermore, the above comparative example, the sensor of the embodiment, not only the detection of vibration, for example Rukoto to the detection of the inclination is also possible, the current based on the current in the current line 12 (detected) As a position sensor for detecting the position of the line 12, it can be used in a wide range of fields.

As shown in FIG. 11 (here, the sensor of the first comparative example is illustrated), each of the comparative examples and the sensor of each embodiment has two or more substrates (here, six substrates 10a to 10f). ) Can be used in layers. In this way, high sensitivity can be achieved.

  The structure shown in FIG. 2 is merely an example of the structure of a vertical Hall element that can be used for this sensor. That is, the present invention is not limited to this, and a vertical Hall element having an arbitrary structure can be used. For example, in the vertical Hall element shown in FIG. 2, the diffusion layers 24 and 25 are provided as separation walls, but trench isolation may be used instead. In addition, the vertical Hall element in which another terminal G is provided and the two terminals G are arranged symmetrically with respect to the terminal S is, in other words, a vertical Hall element in which a driving current is passed in two directions. However, the present invention can be similarly applied.

  Further, the material of the substrate 10 is not limited to the silicon described above, and any semiconductor material can be used. For example, a compound semiconductor can also be used as the material of the substrate 10. Moreover, the sensitivity of the vertical Hall element 11 is generally higher when it is formed on the compound semiconductor substrate than on the silicon substrate. However, on the other hand, the above-described signal processing circuit (for example, an amplifier circuit or a correction circuit that corrects offset and temperature characteristics) is usually manufactured using an inexpensive silicon substrate. A device such as providing a processing circuit as a separate chip is required.

  After all, a semiconductor substrate having a vertical Hall element is provided, and by detecting the magnetism caused by the current of the detection target (current line) arranged perpendicular to the substrate by the vertical Hall element, this If the current sensor detects the current flowing from the magnetism to the current line, at least the intended purpose can be achieved.

First the first comparative example, a perspective view illustrating overview of the current sensor (general structure) schematically the current sensor. As for an example of a vertical Hall element used in the current sensor according to the first comparative example , (a) is a plan view schematically showing a schematic structure of the Hall element, and (b) is an L1- Sectional drawing along L1 line, (c) is sectional drawing along L2-L2 line of (a). The perspective view which shows typically the modification about the arrangement | positioning aspect of the vertical Hall element used for the current sensor which concerns on the said 1st comparative example . The perspective view which shows another modification of the arrangement | positioning aspect typically. The for second comparative example, a perspective view illustrating overview of the current sensor (general structure) schematically the current sensor. The perspective view which shows typically the modification about the arrangement | positioning aspect of the vertical Hall element used for the current sensor which concerns on the said 2nd comparative example . The perspective view which shows typically the outline | summary (schematic structure) of this current sensor about 1st Embodiment of the current sensor which concerns on this invention. The perspective view which shows typically the outline | summary (schematic structure) of this current sensor about 2nd Embodiment of the current sensor which concerns on this invention. The perspective view which shows typically the outline | summary (schematic structure) of this current sensor about the modification of the current sensor which concerns on the said 2nd Embodiment. The perspective view which shows typically the outline | summary (schematic structure) of this current sensor about other embodiment of the current sensor which concerns on this invention. The perspective view which shows typically the outline | summary (schematic structure) of this current sensor about other embodiment of the current sensor which concerns on this invention. The perspective view which shows typically the outline | summary about an example of the conventional current sensor.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10, 10a-10f ... Semiconductor substrate, 11 ... Vertical Hall element, 12 ... Current line to be detected, 21 ... Semiconductor layer, 22 ... Semiconductor region, 22a, 22b ... Region, 23a-23d ... Contact region, 24, 25 ... Diffusion layer (separation wall), BL ... buried layer, CT ... notch, G ... terminal, HP ... magnetic detection part (hall plate), S ... terminal, V1, V2 ... terminal (output terminal).

Claims (11)

A semiconductor substrate on which a plurality of vertical Hall elements are disposed; and a current line disposed perpendicularly to the semiconductor substrate, wherein magnetism generated due to a current flowing through the current line A current sensor that detects a current flowing from the detected magnetism to the current line by detecting with a mold Hall element,
The semiconductor substrate is provided with a space for guiding the current line to a magnetic detection position by the plurality of vertical Hall elements and allowing vibration of the current line at the detection position, and is disposed on the semiconductor substrate. A current sensor characterized by detecting the output of each of the plurality of vertical Hall elements individually and detecting the vibration direction of the current line by specifying the vertical Hall element having the maximum output. A semiconductor substrate on which a plurality of vertical Hall elements are disposed; and a current line disposed perpendicularly to the semiconductor substrate, wherein magnetism generated due to a current flowing through the current line A current sensor that detects a current flowing from the detected magnetism to the current line by detecting with a mold Hall element,
The semiconductor substrate is provided with a space for guiding the current line to a magnetic detection position by the plurality of vertical Hall elements and allowing vibration of the current line at the detection position, and is disposed on the semiconductor substrate. A current sensor for detecting the output of each of the plurality of vertical Hall elements and detecting the position of the current line by specifying the vertical Hall element having the maximum output. It said plurality of vertical Hall element, the around the magnetic detection position, current sensor according to claim 1 or 2 are arranged in a ring on the semiconductor substrate. Wherein the semiconductor substrate has a front SL current line electrically Ku incision enters into the magnetic detection position, a plurality of vertical Hall element disposed in the annular circle on the semiconductor substrate in the form of avoiding this notch The current sensor according to claim 3 , wherein the current sensor is arranged so as to draw a trajectory. Current sensor according to claim 4 pre SL current line the conductive Ku cut to the magnetic position detection, which is the notch to the detection position. The space is provided at an outer edge of the semiconductor substrate, and the plurality of vertical Hall elements arranged in an annular shape are arranged so as to draw a semicircular locus in the vicinity of the outer edge of the semiconductor substrate. 3. The current sensor according to 3 . Said plurality of vertical Hall element, the around the magnetic detection position, current sensor according to claim 1 or 2 formed by arranged so as to be continuous in parallel on the semiconductor substrate. The semiconductor substrate has a notch for guiding the current line to the magnetic detection position, and the plurality of vertical Hall elements are arranged on both sides of the notch so as to be continuous in parallel. Item 8. The current sensor according to Item 7. Current sensor according to any one of claims 4 or 5 or 8 wherein the cut is made is found provided in a vertical direction. The space becomes provided in the vertical direction of the outer edge of the semiconductor substrate, a plurality of vertical Hall element wherein arranged to parallel to sequential, the semiconductor substrate according to claim 7, the outer edge are arranged in a vicinity of the The current sensor described in 1. The semiconductor substrate is a substrate made of silicon, and in addition to the plurality of vertical Hall elements, a circuit that performs predetermined signal processing on signals output from the plurality of vertical Hall elements is provided on the substrate. The current sensor according to any one of claims 1 to 10 , wherein the current sensor is integrated together .

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