JPH04102407U - Magnetoelectric conversion device - Google Patents

Abstract

(57) [Summary] [Purpose] To assemble Hall elements easily and accurately. [Structure] First, a mask structure is prepared, and a holding shape is formed on the mask structure so as to correspond to a desired element spacing. The Hall elements are positioned and assembled by the shape of this mask structure.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

The present invention relates to a magnetoelectric transducer using an element having a Hall effect, and is particularly suitable for measurement. Targeted in fields such as equipment, industrial machine tools, consumer equipment, transportation equipment, and construction equipment. Regarding a magnetoelectric transducer suitable for position detection and displacement detection when automatically positioning objects .

0002

[Background of the idea]

As a magnetic sensor or magnetoelectric conversion element, a Hall element that uses the principle of the Hall effect is used. ferromagnetism, semiconductor magnetoresistive elements that utilize magnetoelectric changes based on the principle of magnetoresistive effect Ferromagnetic magnetoresistive element that utilizes magnetoelectric conversion based on the principle of ferromagnetic resistance effect of metal materials and so on.

0003 Among these, semiconductor magnetoresistive elements are made of materials such as GaAs and InSb. Since the carriers are formed in a single layer, the number of carriers and mobility vary greatly with changes in temperature. For this reason, it is difficult to obtain good temperature characteristics. Also, due to the manufacturing process, the resistance of each element is High resistance to variation. Therefore, countermeasures against these problems are implemented using an external compensation circuit. There is a need.

0004 Furthermore, the sensitivity of the resistance change of this semiconductor magnetoresistive element to the magnetic field is It is approximately proportional to its square, and a certain degree of linearity cannot be obtained in a strong magnetic field of several hundred G or more. It will be done. Therefore, in order to obtain good linearity as a magnetic sensor, it is necessary to use a strong magnetic field bias. It is necessary to provide a large amount of stress, which causes the shape to become complicated and costs to increase. Therefore, Motoko This limits the scope of use of these devices, which poses a major hindrance to design.

[0005] Next, in the case of ferromagnetic magnetoresistive elements, the temperature characteristics are good, but the resistance change is 3 It is small at ~4%. In addition, the element size can be reduced to take advantage of the magnetic anisotropy effect. Therefore, the mass production effect is weakened and the price becomes high. Hall elements are highly effective in mass production and have cost advantages. It is produced and used in many areas. However, with this Hall element, temperature characteristics become a problem. Currently, most circuits turn on when permanent magnets approach each other or when their poles change. , and is used in a switch-like manner, such as turning it off.

[0006] Specifically, the temperature characteristics of the Hall element itself (ranging from 0.03 to several percent of the Hall voltage) ) cannot be ignored, which places considerable restrictions on position detection using Hall elements. It's for a reason. In addition, the magnetic material that serves as the signal source also has temperature characteristics. Therefore, circuit processing for each purpose is required to control both this and the Hall element, and the design There is also the disadvantage that it becomes complicated. Furthermore, in general compensation circuits, thermistor Which auxiliary element is used, but the price of this thermistor element exceeds that of the Hall element. This results in problems such as overflow, resulting in an expensive device configuration.

[0007] By the way, in recent years, the position of magnetic objects has been detected in a non-contact manner using magneto-electric transducers. By doing so, there is a tendency to improve life durability. However, traditional contactless For type magnetic sensors (mainly semiconductor magnetoresistive elements, etc.), sensors are The current method is to design the sensor itself, which lacks versatility and makes the sensor itself difficult to use. The body becomes expensive. For this reason, it has only been implemented in a few areas. stomach. Additionally, as mentioned above, this method requires a complicated circuit configuration for temperature compensation. It is.

[0008] In addition, in many conventional magnetic sensors, external magnetic fields are applied to the magnetic sensing part of the magnetic sensor. The system uses a method to detect the change in resistance when applied. For this reason, the external magnetic field It is necessary to construct a permanent magnet or the like that is to generate a moving object. But this The method is not suitable for relatively large system configurations such as hydraulic cylinders. However, it is also disadvantageous in terms of cost.

[0009] For the above reasons, the sensor section should not be changed much, and the magnetic field should not be exposed to the outside. Even if there is no source, the amount of its own bias magnetic field can be applied to an external magnetic material such as iron. There is a growing demand for a highly versatile magnetic sensor that changes depending on the movement. As this general-purpose use is emphasized, a simpler and more user-friendly structure, and In order to realize a low-cost magnetoelectric transducer, the element itself that becomes the magnetic sensing part must be extremely Therefore, it is required to be small and low cost. To meet this demand, elements using the Hall effect have a proven track record of production and use. In addition, it is possible to obtain a stable magnetoelectric transducer that is good and cost-effective.

0010

[Conventional technology]

The results of detecting the direction of movement and position of a magnetic object are converted into digital electrical signals. In cases where the magnetic object is controlled based on the obtained information, it is usually Sensors are arranged at pitches. In other words, the magnetic sensing part of the Hall element is spaced at a predetermined pitch. At least two or more are arranged so that a phase shift occurs in the detection signal depending on the timing. So When a magnetic sensor configured in this way is brought close to a moving magnetic object, each Magnetoelectric conversion signals with a phase difference of 90 degrees are output from the magnetic sensing section. this The traveling direction of the magnetic object is detected based on the signals from the The movement of the magnetic object is controlled based on this.

[0011] However, with such technology, when the spacing of the magnetically sensitive parts changes, the element chip This means changing the design of the chip itself, lacking in versatility, and requiring quantitative guarantees. This would be disadvantageous in terms of cost. For this reason, it is highly versatile and suitable for changing spacing. As a cost-effective structure that can be used for It consists of a mini-molded chip with one magnetically sensitive part, and There is one in which a plurality of these are arranged on a printed circuit board at predetermined intervals.

0012 FIG. 8 shows a magnetoelectric transducer constructed in this manner. The same figure On the printed circuit board 10, molded chip-shaped hole elements are placed at predetermined intervals. Children 12 and 14 are arranged, respectively. The terminal 16 of each Hall element 12, 14 is Each is connected to a wiring pattern 18 formed on the lint board 10.

[0013]

[Problem that the idea aims to solve]

However, such means have the following disadvantages. General puri When the terminal board 10 is used, the terminals 16 of the Hall elements 12 and 14 can be soldered. The position of the line pattern 18 is shifted relative to the entire substrate. In addition, Hall element 1 2 and 14 on the board 10 and soldering them by dip etc. arise. This kind of deviation results in a deviation in the spacing between the magnetic sensing parts of the element, and as a result, the element cannot be accurately measured. This means that child placement will not be possible. If there is a gap between the magnetic sensing parts of the element, the magnetic This makes it impossible to perform signal detection properly as the object moves. This invention focuses on this point, and allows for accurate and simple assembly of Hall elements. The purpose of the present invention is to provide a magnetoelectric conversion device that can perform the following steps.

[0014]

[Means to solve the problem]

In the present invention, at least two Hall elements have a common magnetic sensing direction. In the magneto-electric transducer arranged at intervals, a a non-magnetic mask structure whose shape corresponds to the desired value of the spacing; It is characterized by

[0015]

[Effect]

According to the present invention, a mask structure is prepared, and the mask structure is arranged to correspond to a desired element spacing. A shape for holding the sea urchin is formed. The Hall element depends on the shape of this mask structure. Positioned and assembled.

[0016]

【Example】

Hereinafter, an embodiment of the magnetoelectric conversion device according to the present invention will be described with reference to the attached drawings. I will explain. FIG. 7 shows a partially broken Hall element used in this example. In the figure, a magnetic sensing part 20 is arranged at the center of the element, and an external part is placed around it. Connection terminals 22 are provided as necessary. Then, from the magnetic sensing part 20 to the terminal 22, a bonding wire 24 made of, for example, Au is extended and connected. There is. This Hall element is molded, and the central magnetic sensing part 20 is attached to the casing. It is designed so that it will not be misaligned. Note that this type of hole element For example, a general-purpose Hall element "VHG601" manufactured by Victor Japan Co., Ltd. ” is there.

[0017] Next, the configuration of this example will be explained along the above-mentioned procedure for assembling the Hall element. do. First, in order to arrange the element magnetic sensing parts 20 at desired intervals, as shown in FIG. A mask structure 30 as shown in is prepared. This mask structure 30 includes a magnetically sensitive element. For example, 0.1 to 0.2 mm in order to avoid unnecessary influence on the portion 20. A non-magnetic material with a thickness of approximately Then, as shown in the same figure, the element sense Frame-shaped holes 32 and 34 are respectively formed for arranging the magnetic parts at desired intervals. child These holes 32 and 34 are large enough to fit the above-mentioned Hall element. The pitch is designed to be the same as the desired spacing L between the element magnetic sensing parts 20. is set equal to .

[0018] The processing of these holes 32 and 34 is used, for example, in semiconductor manufacturing processes. It is performed using photolithography technology, that is, a mask-etching process. This is a metal mask used as a jig when creating thin films by vacuum evaporation. method has been adopted. According to this method, the pitch L of the holes 32 and 34 is It is determined by the precision of the exposure mask for resists, etc., so the It can be formed with some error. Also, the dimensional accuracy of the holes 32 and 34 themselves may be due to the same reason. This makes it possible to reduce errors. Processing using such semiconductor technology This makes it possible to accurately pitch the Hall elements.

[0019] Next, the holes 32 and 34 of the mask structure 30 obtained as described above are Hall elements 36 and 38 are fitted as shown in Figure (B). These hole elements Children 36, 38 are secured to mask structure 30 with adhesive 40. This allows the The spacing between the magnetically sensitive parts 20 of the control elements 36 and 38 is maintained at a good pitch L. Become.

[0020] With respect to the Hall elements 36 and 38 fixed on the mask structure 30 in this way, , magnets 42 and 44 for magnetic bias are installed, respectively, as shown in FIG. and , leads 48 extending from the lead frame 46 are terminals of the Hall elements 36 and 38. 22 is soldered. Note that the lead frame for the Hall elements 36 and 38 46 is positioned using a plurality of reference holes 50.

[0021] Next, as shown in FIG. 3, the case 52 is attached on the mask structure 30. In both cases, resin 54 is filled in this case 52. Then, as shown in Figure 4, The lead frame 46 is removed and the sensor unit of the magnetoelectric transducer 60 is removed. The knit is completed. As mentioned above, the distance between the magnetically sensitive parts of the Hall elements 36 and 38 is It is well maintained at L by the action of the mask structure 30.

[0022] Next, a detection operation by the magnetoelectric transducer as described above will be explained. magnetoelectric conversion The device 60 is placed close to a soft magnetic material 62 such as iron having irregularities as shown in FIG. placed next to each other. The period of the uneven shape provided on the surface of the soft magnetic material 62 is λ. . Then, the magnetoelectric conversion device 60 has ΔA with respect to the convex portion 64 of the soft magnetic material 62, and the concave portion 6 6 with a gap of ΔB. The gap ΔA is an analogy For example, the gap ΔB is about 100 μm to 1 mm. be.

[0023] Furthermore, the distance L between the magnetically sensitive parts 20 of the Hall elements 36 and 38 mentioned above and the circumference of the unevenness The period λ is for n=0, 1, 2, 3,... L=(1/2)(n+(1/2))λ =((n/2)+(1/4))λ…(1) In other words, the relationship is set to be a relationship that is shifted by 1/4 period with respect to the concavo-convex period λ.

[0024] In this state, as shown by arrow F in the figure, the soft magnetic material 62 is connected to the magnetoelectric converter 60. If the Hall elements 36 and 38 are moved relative to each other, the convex portions of the soft magnetic material 62 64, the recesses 66 come closer to each other alternately. In the Hall elements 36 and 38, the convex portion 64 approaches, the detection output absolute value increases, and as the recess 66 approaches, the detection output absolute value increases. value decreases. Due to such signal changes, the position of the soft magnetic material 62 is digitally determined. will be detected.

[0025] By the way, as mentioned above, the Hall elements 36 and 38 are The arrangement is shifted by /4 periods. For this reason, for example, the soft magnetic material 62 is 6, the detected output signal waveforms of the Hall elements 36 and 38 are shown in FIG. As shown in rough GA and GB, the output of the Hall element 3 corresponds to the output of the Hall element 36. The output of 8 will be delayed by 90 phases.

[0026] Conversely, if the soft magnetic material 62 moves in the direction of arrow FB, the Hall elements 36, 38 The detection output signal waveforms of , conversely, are as shown in graphs GB and GA, and the waveforms of the detection output signals of Hall element 3 The output of the Hall element 36 is delayed by 90 phases with respect to the output of 8. This way By looking at the phase relationship between the outputs of the Hall elements 36 and 38, the soft magnetic material 6 The direction of movement of 2 is grasped. These detection signals are supplied to a control means (not shown), which controls the soft magnetic material. 62 displacement control is performed as necessary.

[0027] As described above, according to this embodiment, since the mask structure is used, the hole The elements are precisely positioned at the desired intervals to provide a reliable and good detection signal. It will be done. In addition, since a magnet is installed inside the unit, it can be used even if it is a simple iron material. However, the position can be detected by changing the amount of magnetic bias caused by the magnet. Linear scales and rotary scales can be easily configured. Furthermore, for magnetic bias Since the magnets are provided, the distance between the magnets is well adjusted to increase output and temperature. Characteristics can be improved and temperature-stable operation can be realized. Also, the design It can respond well to changes, and because it uses a Hall element, it is cost-effective. be.

[0028] Note that the present invention is not limited to the above embodiments. For example, mass In the block structure 30, the end portion and the holes 32, 34 have a predetermined distance relationship. It is also possible to form holes 32, 34 in. Such a setting is the same for holes 32 and 34. It can be performed with extremely high accuracy similar to the formation of the mask structure 30, and By making the surface protrude beyond the case 52 and using it as a reference, the sensor can be adjusted while maintaining accuracy. It becomes possible to assemble the unit.

[0029] Further, in the above embodiment, the holes 32 and 34 have a shape for positioning the Hall element. However, you may choose any other shape as necessary, such as a concave shape. . In addition, the case 52 was used, but the mold was integrated with resin molding. You may. Furthermore, the number of Hall elements is also arbitrary, and more can be arranged as necessary. You may also do so.

[0030]

[Effect of the idea]

As explained above, according to the magnetoelectric transducer according to the present invention, Since the Hall elements are arranged in a shape that can be held, it can be held easily and accurately. It is possible to assemble the integrated circuit elements, has good mass productivity, and is cost-effective. There is an effect.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing the main parts of an embodiment of a magnetoelectric transducer according to the present invention.

FIG. 2 is an explanatory diagram showing the manufacturing process of the embodiment.

FIG. 3 is an explanatory diagram showing the manufacturing process of the embodiment.

FIG. 4 is an explanatory diagram showing the manufacturing process of the embodiment.

FIG. 5 is an explanatory diagram showing the operation of this embodiment.

FIG. 6 is a graph showing an example of a detection signal waveform according to the present embodiment.

FIG. 7 is an explanatory diagram showing a schematic structure of a mini-mold Hall element.

FIG. 8 is an explanatory diagram showing a conventional technique.

[Explanation of symbols]

20...Magnetic sensitive part, 22...Terminal, 30...Mask structure, 32,
34... Hole, 36, 38... Hall element, 40... Adhesive, 4
2, 44...Magnet, 46...Lead frame, 48...Lead, 50...Reference hole, 52...Case, 54...Resin, 60...
Magnetoelectric conversion device, 62... Soft magnetic material, 64... Convex portion, 66... Concave portion.

Claims (1)

[Scope of utility model registration request] 1. A magnetoelectric transducer in which at least two Hall elements are arranged at intervals such that their magnetic sensing directions are common, wherein a shape for holding the Hall elements is set to a desired value of the interval. A magnetoelectric conversion device characterized by comprising a non-magnetic mask structure formed in accordance with.