JPH0210181A - Magnetic sensor device - Google Patents

Abstract

PURPOSE:To obtain the magnetic sensor device by which the detection width is large and exact by one scan by placing plural semiconductor chip elements on which magnetic detecting elements have been arrayed by doubling the end parts along the longitudinal direction of an element containing part. CONSTITUTION:Magneto-resistance elements 2a, 2b are formed at a prescribed pitch in the direction being orthogonal to the scanning direction (x) on a semiconductor chip element 13. These elements are arranged by plural pieces in the longitudinal direction of a magnet 12, placed in an element containing part of a pedestal, by which a magnetic sensor device is constituted. In this case, by doubling and placing an end part A and Z of semiconductor chip elements 13a-13d, the magnetic detecting elements are arranged continuously at a prescribed interval in the width direction, the detection width by one scan becomes large enough, and also, its detection can be executed exactly. Also, the magnetic detecting element can be formed simply on the semiconductor chip element by pattern printing.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a magnetic sensor device that detects abnormalities such as scratches or foreign matter adhesion on the surface of a detected object made of a magnetic material such as an iron plate by means of magnetic changes. It is.

[Prior Art] Magnetic sensors are widely used as devices for reading magnetic codes formed on cards or as pulse generators, but they are still difficult to detect scratches and foreign objects on the surface of wide magnetic materials such as iron plates. It has not been developed as a dedicated device for scanning detection.

[Problem to be solved by the invention]

A magnetic sensor generally has a pair of magnetoresistive elements 2a and 2b arranged on the magnetic pole surface of a magnet 1, as shown in FIG. The equivalent circuit of this magnetic sensor is shown in FIG. 13, where the resistance of the magnetoresistive element 2a is Ml,
Resistor b is M 21 input terminal is V CC+ Output voltage is ■. , then v,,t = (M2/(M, +M2
)) Vcc-N).

Therefore, for example, as shown in FIG. 14, if we consider the case where the iron plate 4 with scratches 3 and foreign matter on the surface side of the magnetoresistive elements 2a and 2b is moved in the direction of the arrow, first, the first
4 In the state shown in Fig. 4(a), the remagnetoresistive elements 2a and 2b are scratched 3.
Since the pixel elements 2a and 2b face a surface with no surface, the magnetic field from the magnet 1 hits the pixel elements 2a and 2b equally and perpendicularly, and as a result, the resistances are equal and M1=M2, so the output voltage from the magnetic sensor is . uL=■cc/2. Next, the first
As shown in Figure 4(b), when the scratch 3 is in a position facing the magnetoresistive element 2a, the magnetic field of the magnet 1 hits the element 2b perpendicularly, but the magnetic field hits the element 2a obliquely, so The resistance M of the element 2b becomes smaller than the resistance M2 of the element 2b, and the output voltage becomes ■. .

decreases as shown at A in FIG. Next, as shown in FIG. 14(c), when the scratch 3 is located between the pixel elements 2a and 2b,
Since the pixel elements 2a and 2b face the flat surface of the iron plate 4 again, M,=M, and the output voltage becomes ■. ut is B in Figure 15
As shown in , it becomes ■cc/2. And Fig. 14 (d
), when the scratch 3 faces the element 2b, M, >
becomes M2, and the output voltage is ■. 6° increases as shown in FIG. 15C. In addition, when the iron plate 4 is a flat surface without scratches 3, the output voltage is V. As shown in FIG. 16, uL is ■. u
It becomes a constant output waveform of L-Vcc/2.

In this way, the 15th
An output waveform as shown in FIG. 16 is obtained, and flaws 3 on the surface of the iron plate can be detected. In this case, when the scratch 3 is shallow, the portion B of the waveform of the output voltage ■ouL changes as shown by the broken line. In this way, various output voltage waveforms are obtained depending on the form of the flaw 3. Therefore, by analyzing this output waveform, it is possible to determine the size and depth of the flaw 3.
The shape and position can be determined, and furthermore, the size, shape, etc. of the foreign matter attached to the iron plate 4 can also be determined in the same manner.

However, when using this type of magnetic sensor to detect scratches 3 or foreign objects on an iron plate or the like over the entire surface, the detection width of the magnetic sensor E is extremely narrow. A plurality of scanning areas 5a, 5 are formed in the width direction of the iron plate 4.
b, . Furthermore, in this method of inspecting the surface of the iron plate 4 by repeatedly scanning each of the scanning regions 58 to 5n, detection information about the flaws 3a to 3g detected in each region 5a to 5n is obtained temporally disparately. Therefore, a problem arises in that it becomes extremely troublesome to analyze the detected information to determine the position, size, and shape of the flaw 3 and the like.

The present invention was made in order to solve the above-mentioned problems that arise when a magnetic sensor is applied as a device for inspecting the surface of iron plates, etc., and its purpose is to expand the detection width that can be detected in one scan. An object of the present invention is to provide a magnetic sensor device that can accurately detect information on flaws and foreign objects present on the entire surface of a detected object, for example, by - times of scanning.

[Means to solve the problem]

In order to achieve the above object, the present invention is configured as follows. That is, the present invention is a magnetic sensor device that scans the surface of a detected object made of a magnetic material and detects abnormalities based on changes in the magnetic field, in which a magnetic detection element is arranged at a predetermined pinch interval in a direction orthogonal to the scanning direction. a pedestal comprising a plurality of semiconductor chip/knob elements arranged in a row, and a pedestal having an element accommodating portion whose longitudinal direction is perpendicular to the scanning direction, and the plurality of semiconductor chip elements are positioned with respect to each other in the scanning direction. The one or more magnetic detecting elements arranged along the longitudinal direction of the element accommodating portion are staggered, and the one or more magnetic detecting elements arranged at adjacent ends of the respective semiconductor chip elements overlap each other in the scanning direction. The structure is characterized by the fact that they are arranged in parallel.

[Function] In the present invention, for example, if the length of the element accommodating portion of the pedestal is formed to be approximately equal to the width dimension of the detected object, and the semiconductor chip element is disposed over the entire length of this element accommodating portion in the longitudinal direction. , the magnetic detection elements face each other at a predetermined pitch interval over the entire width of the object to be detected.

If either the magnetic sensor device or the detected object is scanned once in the scanning direction (lengthwise direction of the detected object) in this state,
Accurate information on flaws and the like on the entire surface of the object to be detected can be obtained at once from the detection signals from each magnetic detection element.

[Example] Hereinafter, an example of the present invention will be described based on the drawings. FIG. 1 shows a plan view of an embodiment of a magnetic sensor device according to the present invention. In the figure, the pedestal 6 is made of a non-magnetic material such as a non-magnetic metal, synthetic resin, or bakelite (Bakelite in this embodiment), and as shown in FIG. Long slot 7
is opened in the longitudinal direction along the center line, and further,
Slit holes 10a and 10b are formed on both sides of the long hole 7 through inner walls 8a and 8b in parallel to the long hole 7. The top surfaces of the inner walls 8a and 8b are lower than the top surface of the edge wall 11 by providing a step t. Note that this thickness is somewhat larger than the thickness of flexible wiring boards 21a and 21b, which will be described later.

A long magnet I.12 is fitted and fixed in the long groove hole 7, and a plurality of semiconductor chip elements 13 are arranged on the magnetic pole surface of the magnet 12 in the longitudinal direction of the magnet 12, as shown in FIG. are arranged side by side. FIG. 4 shows a detailed picture of this semiconductor chip element 13. This semiconductor chip element 3 has a magnetic detection element 15 and a conductive pattern connecting the element 15 printed on the surface of a wafer 14.
is a pair of magnetoresistive elements 2a and 2b in the scanning direction (X in the figure).
direction), and the pixel elements 2a,
2b are connected in series through a conductor portion 16. This magnetic detection element 15 is connected to the wafer 1.
A predetermined pinch interval P (
In this embodiment, a plurality of them (101 in this embodiment) are arranged at equal pinch intervals of 0.20.

On the other hand, on both sides of the wafer 14 in the longitudinal direction, a GND terminal pattern 17 and an input terminal pattern 18 are formed of conductors, and the GND terminal pattern 17 is connected to each magnetic detection element 15a to
The input terminal pattern 18 is connected to one end side terminal (terminal of the magnetic resistance element 2a) of the magnetic detection element 15n.
5a = connected to the other end terminal (terminal of the magnetoresistive element 2b) of 15n. In other words, each magnetic detection element 15
As shown in the connection diagram of FIG. 8, a to 15n are connected in parallel by the GND terminal pattern 17 and the input terminal pattern 18. In addition, each magnetic detection element 15a to 1
Each output terminal pattern 2o of the conductor is
direction, and its tip end is connected to the connecting terminal portion 20a.
It becomes. These connection terminal portions 20a are arranged at equal pitches in the X direction (equal pitches of 0.2 mm in this embodiment).
Arranged in As shown in FIG. 5, the surface of this wafer 14 is covered with an insulating material 1, leaving the connecting terminal portion 20a.
9.

A plurality of semiconductor chip elements 13a, 13b, 13c, and 13d coated with insulation in this manner are mounted on the base 6.
As shown in FIG. 3, it is arranged on the magnetic pole face of a long magnet 12 which is inserted and fixed in the magnet. In this case, as shown in FIG. 9, if a semiconductor chip element 13 of approximately the same length as the elongated magnet 12 is prepared and placed on the magnetic pole face, a plurality of ni-element elements can be formed as shown in FIG. H3a-13
The arrangement work is easier than aligning and arranging d. However, as is well known, the wafer 14 has extremely high component purity, and it is extremely difficult to manufacture a long wafer 14 with such high purity due to manufacturing technology. The length is the limit.

Therefore, when inspecting an object to be detected such as a wide steel plate 4,
A magnet 12 having the same width as the iron plate 4 is prepared, and a plurality of semiconductor chip elements 13a to 13d each having a length of about 1 inch are arranged side by side on the magnetic pole face of the magnet eye 2. This semiconductor Chimpelemenes 3a-13
d, it is conceivable to arrange the elements 13a to 13n in tandem in the X direction without shifting their positions in the X direction, as shown in FIG. However, in this case, the adjacent semiconductor chip elements 138 to 1
It is difficult to correctly align the 3n magnetic sensing elements 15n and 15a at a predetermined pitch interval, and in addition, when the pinch interval is as small as 0.2 mm as in this embodiment, each adjacent element 13a to The ends of each element 138 to 13d must be cut at a position close to the magnetic detection elements 15n and 15a so that the ends of the elements 13d do not overlap, and the cutting operation becomes very troublesome.

In this embodiment, from the viewpoint of avoiding such trouble, the respective semiconductor chip elements 13a to 13d are arranged with their positions shifted in the X direction (scanning direction), and each element 13
At least one of the magnetic detection elements at adjacent ends of a to 13d is aligned so that their center lines coincide with each other in the scanning direction. In other words, in FIG. 3, several magnetic detection elements Z at the end of the element 13a are arranged so as to overlap in position in the scanning direction with respect to several corresponding magnetic detection elements A at the start end of the element 13b. Similarly, element 1
The magnetic sensing element Z on the terminal end side of element 13b is connected to the magnetic sensing element A on the starting end side of element 13c, and the magnetic sensing element Z on the terminal side of element 13c is connected to the magnetic sensing element A on the starting end side of Niremen l-13d in the X direction. They are arranged in overlapping positions. In this way, the magnetic detection element 1 at the end of each element
5 overlap in the scanning direction, the magnetic detection elements 15n at the ends of each element, as shown in FIG.
This is easier than aligning the magnetoresistive elements 15a at a predetermined pitch interval, and moreover, each pair of magnetoresistive elements 2a and 2b can be correctly aligned parallel to the scanning direction (each element can be arranged without being tilted). , it is possible to improve workability and detection accuracy.

By the way, in this embodiment, as shown in FIG. 6, flexible wiring boards 2La, 21
b is inserted through the slit holes 10a, 10b, and its insertion tip is placed and fixed on the top surface of the inner walls 8a, 8b. These flexible wiring boards 21a, 21b
has a GND wiring pattern and an input wiring pattern inside,
A plurality of output wiring patterns having the same pinch as the output terminal patterns 20 of the semiconductor chip elements 13a to 13d are formed, the GND wiring pattern is connected to the GND terminal pattern 17 of each element 13a to 13d, and the input wiring pattern is connected to the element 138. -13d are connected to the input terminal patterns 18, respectively. Then, the output wiring pattern on the flexible wiring board 2Ia side is connected to the connection terminal portion 20a of the output terminal pattern of the elements 13a and 13c by bonding, and similarly, the output wiring pattern on the flexible wiring board 2Ia side
The output wiring pattern on the 1b side is Niremen) 13b, 13d
It is connected to the connection terminal portion 20a of the side output terminal pattern. Further, a connector 22 is connected to the other end side of the flexible wiring boards 2La and 21b, and an input voltage Vcc is applied to the input terminal pattern 18 via the connector 22, and signals from each magnetic detection element 15a to 15n are applied to the input terminal pattern 18. is being extracted.

Further, a cover 23 made of a non-magnetic material with excellent wear resistance, made of tungsten in this embodiment, is placed on the top side of the pedestal 6 with a constant gap 24 formed between it and the semiconductor chip element 13. ing.

When this gap 24 is not formed, the iron plate 4 of the detected object
When a pressing force is applied to the cover 23 side, the cover 23 is bent and pressure is applied to the semiconductor chimney element 3, and a piezo voltage is generated from the magnetoresistive elements 2a and 2b. This piezo voltage acts as noise and impairs the reliability of the magnetic detection element 15.

In this embodiment, in order to avoid such a disadvantage, the following measures are taken to form an appropriate gap 24. FIG. 7 shows a method of assembling the magnet 12 to form this gap 24. When assembling this magnet 12 into the pedestal 6, place the pedestal 6 upside down on the surface plate 25 (with the top surface of the pedestal 6 in contact with the surface plate 25), and
A spacer 2 is provided between the top surfaces of the inner walls 8a and 8b and the surface plate 25.
Interpose 6. The thickness of the spacer 26 is the sum of the thickness of the semiconductor chip element 13 and the appropriate gap L9 formed between the element 13 and the cover 23, which is 1. +
1. Form to the same dimensions as. In this way, spacer 2
6 is interposed, the magnet 2 is inserted into the long slot 7 from the bottom side of the pedestal 6, and the magnet 12 is fitted until the distal end surface contacts the spacer 26. In this state, the proximal end of the magnet 12 ( (bottom side) to the inner walls 8a, 8b of the pedestal 6. In this state, if the elements 13a to L3d are glued to the upper surface (pole surface) of the magnet 12 and the cover 23 is placed on the pedestal 6, each element 13a to L3d is attached.
A suitable gap 24 of t9 will be formed between 3d and the cover 23.

When inspecting the surface of the iron plate 4 using the magnetic sensor device configured as described above, as shown in FIG.
First, the reference position of the magnetic sensor device W27 in the x and Y directions with respect to the iron plate 4 is determined. If either the magnetic sensor device 27 or the iron plate 4 is moved once in the scanning direction (X direction) in this positioning state, information on scratches 3a to 3g and foreign objects on the iron plate surface can be detected by the magnetic detection elements of each element 13a to 13d. 15
a to 15n, each element 138
By analyzing the detected waveforms as shown in FIG. 15 from the elements 15a to 15n of 13d to 13d, the size, shape, and position of the flaws 3a to 3g and foreign objects on the iron plate surface can be immediately determined.

According to the present embodiment, the magnetic detection elements 15a to 15n are formed in the semiconductor chip element 13 by printing, and the output signals from the magnetic detection elements 15a to 15n are taken out by the flexible wiring boards 21a and 21b. With this structure, it is possible to arrange the magnetic detection elements 15a to 15n and the terminal portions at a fine pitch, thereby increasing the detection accuracy of the device 27 and increasing the efficiency of the mounting density of the terminal portions.

Further, the flexible wiring boards 121a and 21b are inserted into the long slots 7 from the bottom side of the pedestal 6 and fixed to the top faces of the inner walls 8a and 8b, and the flexible wiring boards 21
Since the magnetic sensing elements 15a to 15n and the substrates 21a and 21b are not routed above the pedestal 6,
The flexible wiring boards 21a and 21b do not get in the way when making bonding connections with the connectors b and attaching the cover 23 (the cover attachment work can be done more efficiently).

Furthermore, since an appropriate gap 24 is formed between each semiconductor chip element 13a to 13d and the cover 23,
Even if the cover 23 is pushed by the object to be detected and bent during use of the device, it will not come into contact with the semiconductor chips 13a to 13d and generate a piezoelectric voltage, thereby ensuring sufficient reliability of the detected data. can be increased.

Furthermore, in the above embodiment, the semiconductor chip
The surface of 13d is the connection terminal part 20 of the output terminal pattern 20
This connection terminal part 2 is coated with insulation except for part a.
0a and the terminal portions of the flexible wiring boards 21a and 21b can be cross-wired with each terminal pattern 17 and 18 through this insulating coating material, and the wiring integration efficiency can be greatly increased. becomes.

Note that the present invention is not limited to the above-mentioned embodiments, and can take various embodiments. For example, in the above example,
Although the magnetic detection element 15 is configured by a pair of magnetoresistive elements 2a and 2b, the magnetic detection element 15 is configured using a Hall element.
can also be configured.

In this case, the magnet 12 can be omitted (and therefore the elongated hole 7 can also be omitted), and the semiconductor chip element 13 on which the Hall element is printed is fixed to the top surfaces of the inner walls 8a and 8b. In this case, when inspecting the object to be detected, a bias magnetic field is applied to the object by winding a coil, for example. On the other hand, as in this embodiment, the magnetic detection element 15 is formed by magnetoresistive elements 2a and 2b, and the semiconductor chip element 13a = 13d on which these elements 2a and 2b are printed is connected to the magnet 12.
If the magnet 12 is placed on the magnetic pole surface of the sensor, the magnet 12 will apply a bias magnetic field to the magnetoresistive elements 2a and 2b, and there is no need to apply a bias magnetic field to the object to be detected, making handling very convenient.

〔Effect of the invention〕

As explained above, the present invention has a plurality of semiconductor chip elements in which magnetic detection elements are arranged at a predetermined pitch interval, which are arranged along the element accommodating section, that is, in a direction perpendicular to the scanning direction. The detection width that can be detected in one scan can be made sufficiently large. For example, if these semiconductor chip elements are arranged over a length equal to the width of the object to be detected, a large object with a width of several meters can be obtained. Even if the object is to be detected, it is possible to detect flaws or adhesion of foreign matter on the entire surface of the object by scanning only once, and the inspection time can be significantly shortened.

In addition, since the magnetic detection elements on the end side of each semiconductor chip element arranged in the element accommodating part are arranged so as to overlap each other in the scanning direction, magnetic detection can be carried out seamlessly in the width direction of the detected object. The elements are arranged at predetermined pitch intervals.

Therefore, the scanning position of each magnetic detection element is accurately related to the object to be detected on a one-to-one basis, and if the reference position of the scanning starting point is determined with respect to the object to be detected and the device is scanned from that reference position, , Accurate information on the size, shape, position, etc. of flaws and foreign objects on the surface of the object to be detected can be immediately obtained with a single scan.

Furthermore, since the magnetic detection elements are formed on semiconductor chip elements, the magnetic detection elements can be arranged at minute pitches by pattern printing, thereby making it possible to sufficiently improve the detection accuracy of the device. Moreover, since the wiring pattern of each magnetic sensing element can be printed simultaneously on the semiconductor chip element, the wiring of each magnetic sensing element is completed in the pattern printing process.
The terminal connection process for each magnetic detection element is greatly simplified.

[Brief explanation of the drawing]

FIG. 1 is a plan view of a magnetic sensor device showing an embodiment of the present invention, FIG. 3 is an explanatory diagram showing the arrangement of the semiconductor chip elements in the same embodiment, FIG. 4 is a pattern diagram of the semiconductor chip elements, and FIG. Figure 6 is an assembly state diagram of the same embodiment device, Figure 7 is an explanatory diagram showing how to assemble the pedestal and magnet,
FIG. 8 is a wiring diagram of a magnetic detection element, FIGS. 9 and 10 are explanatory diagrams showing other arrangement examples of semiconductor chip elements,
FIG. 11 is an explanatory diagram showing an example of scanning by the apparatus of this embodiment, and FIG.
The figure is a block diagram of the magnetic sensor, Figure 13 is an equivalent circuit diagram of the magnetic sensor, Figure 14 is an explanatory diagram showing an example of flaw detection on the surface of a steel plate using the magnetic sensor, and Figure 15 is the output of flaw detection by the magnetic sensor. Waveform Diagram, 20- Figure 16 is an output waveform diagram of the magnetic sensor in a state where there are no scratches, and Figure 17 is an explanatory diagram showing an example of scanning the surface of a wide iron plate using the magnetic sensor. 1... Magnet, 2a, 2b... Magnetoresistive element,
3.3a-3g...Scratch, 4...Iron plate, 5a-5n.
...Scanning area, 6...Pedestal, 7...Long slot, 8a,
8b...Inner wall, lOa, 10b...Slit hole,
11... Edge wall, 12... Magnet, 13...
Semiconductor chip element, 14... wafer, 15...
・Magnetic detection element, 16... Conductor part, 17... GND
Terminal pattern, 18... Input terminal pattern, 19...
・Insulating material, 20... Output terminal pattern, 20a...
Connection terminal portion, 21a, 21b...Flexible wiring board, 22...Connector, 23...Cover, 24...
・Gap, 25... Surface plate, 26... Spacer, 27.
...Magnetic sensor device.

Claims (1)

[Claims] A magnetic sensor device that scans the surface of a detected object made of a magnetic material and detects abnormalities based on changes in the magnetic field, comprising a plurality of magnetic detection elements arranged at predetermined pitch intervals in a direction perpendicular to the scanning direction. a pedestal comprising a semiconductor chip element and an element accommodating part whose longitudinal direction is perpendicular to the scanning direction, and the plurality of semiconductor chip elements are shifted in position from each other in the scanning direction so as to extend along the longitudinal direction of the element accommodating part. The one or more magnetic detection elements arranged along the scanning direction and arranged on adjacent end sides of each of the semiconductor chip elements overlap each other in the scanning direction. sensor device.