KR101056751B1 - Non-destructive Sensor for Magnetic Leak Detection and Manufacturing Method - Google Patents

Abstract

The present invention relates to a non-destructive sensor for magnetic leakage inspection and a manufacturing method, and more particularly, the magnetic thin film portion and the sub magnetic thin film portion constituting the magnetic path forming portion is formed by alternately arranged magnetic layers and insulating layers, The generation of the eddy current can be reduced, and the magnetic thin film portion and the sub magnetic thin film portion adopt a structure in which the magnetic layer and the insulating layer are alternately arranged, so that the eddy current at high frequency is reduced, so that the defect characteristic of the subject can be detected with high sensitivity. If the non-destructive diagnostic system can be built using the non-destructive sensor, and the actual imaging system can be easily diagnosed by the general public, the inspection and diagnosis time can be shortened, and the manpower and inspection cost can be drastically reduced.

The non-destructive sensor for magnetic leak detection of the present invention includes a coil to which an electrophoresis is applied to generate a magnetic field to detect a minute crack, and a magnetic path forming unit for forming a magnetic path of the magnetic field generated by the coil, wherein at least a part of the magnetic field forming unit The region is characterized in that the magnetic layer and the insulating layer are laminated alternately.

Non-destructive sensor, magnetic path forming part, main magnetic thin film part, sub magnetic thin film part, magnetic layer, insulating layer, alternating arrangement, eddy current reduction, object defect, high sensitivity detection.

Description

Non-destructive sensors for Magnetic leakage testing and manufacturing method

According to the present invention, the magnetic thin film portion and the sub magnetic thin film portion constituting the magnetic path forming portion have a form in which the magnetic layer and the insulating layer are alternately arranged alternately, thereby reducing the generation of eddy currents, and the magnetic thin film portion and the sub magnetic thin film portion are magnetic layers. By adopting a structure in which the insulating layers are alternately arranged, the eddy current at high frequency is reduced, so that the defect characteristic of the subject can be detected with high sensitivity, and the non-destructive diagnostic system can be constructed using the non-destructive sensor to easily diagnose even the general public. It is a technology related to non-destructive sensor for magnetic leak detection and a manufacturing method that can reduce inspection and diagnosis time and drastically reduce manpower and inspection cost if an actual imaging system is configured.

1 is a view showing a non-destructive sensor for magnetic leakage inspection using a conventional Hall sensor, as shown in FIG. 1, a conventional non-destructive sensor for magnetic leakage inspection includes a magnetic portion and a coil portion, the coil is magnetic It has a structure surrounding the portion in the form of a solenoid, the magnetic portion forms a magnetic field of the magnetic field when a current is applied to the coil. The magnetic field from the magnetic part toward the subject forms the path back to the magnetic part after magnetizing the subject, thereby recording the defect of the subject.

In addition, as the sensitivity is increased, a high frequency current is applied to the coil. The main magnetic thin film portion, the upper magnetic thin film portion, and the sub magnetic thin film portion are generally magnetic materials having relatively small values of about 20 to 40 micro ohms / cm. As a result, eddy currents occur at high frequencies. This eddy current increases the response time of the magnetic field to the sensitivity and lowers the magnetic permeability of the magnetic material at the high frequency, thereby inhibiting the characteristics of the high frequency sensitivity.

The magnetic leak detection sensor is used to detect cracks in a subject. As a chance to become competitive in developed countries with long research history and large technology market for non-destructive sensors, we can preoccupy international standardization of related sensors as a new high technology holder. The economic expectation effect can greatly reduce the import dependence of equipment, which accounts for 95%, resulting in import substitution effect, reduce the production cost due to high productivity, and be competitive in price, and make the new smart non-destructive diagnosis system easier for the general public. Configuring a real imaging system that can be diagnosed can reduce inspection and diagnostic time and drastically reduce manpower and inspection costs.

Therefore, in order to realize high-sensitivity sensing, the development of a non-destructive sensor for magnetic leak detection that can minimize the generation of eddy current at high frequency is urgently required.

Accordingly, the present invention has been conceived to solve the above problems, the structure of the magnetic thin film portion and the sub magnetic thin film portion constituting the magnetic path forming portion is formed by alternatingly arranged magnetic layer and insulating layer, it is possible to reduce the occurrence of eddy current The purpose of the present invention is to provide a non-destructive sensor and a manufacturing method for magnetic leak detection.

Another object of the present invention is to adopt a structure in which the magnetic thin film portion and the sub magnetic thin film portion are alternately arranged with the magnetic layer and the insulating layer, so that the eddy current is reduced at a high frequency, so that magnetic leakage inspection can detect the defect characteristic of the subject with higher sensitivity. To provide a non-destructive sensor and a manufacturing method.

In addition, another object of the present invention is to build a non-destructive diagnostic system using a non-destructive sensor to configure a real imaging system that can be easily diagnosed even to the general public, the inspection and diagnosis time is reduced, bringing a drastic reduction in manpower and inspection costs The present invention provides a non-destructive sensor and a manufacturing method for magnetic leakage inspection.

Non-destructive sensor for magnetic leak detection in accordance with a preferred embodiment of the present invention for achieving the above object is to form a magnetic field of the magnetic field generated by the coil and the coil to which the current is applied to generate a magnetic field to detect a minute crack Although the forming portion is provided, the region of the magnetic path forming portion is characterized in that the magnetic layer and the insulating layer is laminated structure alternately.

In the present invention, the magnetic path forming portion and the main magnetic thin film portion having a magnetic layer for applying a magnetic field for detecting the microcracks; Forming a magnetic path together with the main magnetic thin film portion, the magnetic thin film portion having an end portion facing the upper magnetic thin film portion with a predetermined gap therebetween; A sub magnetic thin film portion spaced apart from the magnetic thin film portion in a direction away from the subject having the microcracks so that a magnetic field is connected to the magnetic thin film portion; Characterized by including.

In the present invention, the sub magnetic thin film portion is formed on the upper or lower surface of the main magnetic thin film portion.

In the present invention, the main magnetic thin film portion and the upper magnetic thin film portion; A magnetic thin film unit having a structure in which a magnetic layer and an insulating layer are alternately stacked; Characterized in that comprises a.

In the present invention, the sub-magnetic thin film portion is characterized in that the structure is alternately laminated with the magnetic layer.

In the present invention, the insulating layer is characterized in that formed of any one of Al ₂ O ₃ , SiO ₂ , SiN, MgO.

In the present invention, the magnetic layer is formed of any one of CoFe, CoNiFe, FeTaN, NiFe.

In addition, the method of manufacturing a non-destructive sensor for magnetic leakage inspection according to a preferred embodiment of the present invention for achieving the above object is provided with a main magnetic thin film portion consisting of a magnetic thin film portion and a yoke portion having a structure in which a magnetic layer and an insulating layer are alternately stacked, Forming a magnetic material layer (A); Patterning and etching the magnetic material layer according to the shape of the magnetic thin film portion (b); Alternately stacking a magnetic layer and an insulating layer on the etched region; .

In the present invention, the step (b) is characterized in that it is performed using a bi-layer photo resist pattern.

In the present invention, the magnetic layer is formed of any one of CoFe, CoNiFe, FeTaN, NiFe.

In the present invention, the insulating layer is characterized in that formed of any one of Al ₂ O ₃ , SiO ₂ , SiN, MgO.

In the present invention, the thickness of the magnetic layer ML and the insulating layer IL, or the number of alternating stacks may be appropriately determined in consideration of the specific resistance value of the magnetic layer ML and the frequency of the current applied to the coil C. It is characterized by.

Non-destructive sensor for magnetic leak detection and the manufacturing method according to the present invention has the following effects.

First, the present invention forms a structure in which the magnetic thin film portion and the sub magnetic thin film portion constituting the gyro forming portion are arranged repeatedly alternately with the magnetic layer and the insulating layer, thereby reducing the generation of eddy currents.

Second, the present invention employs a structure in which the magnetic thin film portion and the sub magnetic thin film portion are alternately arranged with the magnetic layer and the insulating layer, so that the eddy current at the high frequency is reduced, so that the defect characteristic of the subject can be detected with high sensitivity.

Third, the present invention can build a non-destructive diagnostic system using a non-destructive sensor to configure a real imaging system that can be easily diagnosed even by the general public can reduce the inspection and diagnosis time, it can bring a drastic reduction in manpower and inspection cost .

Looking at the preferred embodiment of the present invention together with the accompanying drawings as follows, when it is determined that the detailed description of the known art or configuration related to the present invention may unnecessarily obscure the subject matter of the present invention The description will be omitted, and the following terms are terms defined in consideration of functions in the present invention, which may vary according to the intention or custom of the user or operator, and the definition thereof is the present invention. It should be based on the content throughout this specification that describes

2 is a cross-sectional view schematically showing the structure of the magnetic leakage detection non-destructive sensor according to an embodiment of the present invention, Figure 3 is a eddy current is reduced in a structure in which the magnetic layer and the insulating layer is repeatedly arranged in accordance with an embodiment of the present invention 4 is a schematic cross-sectional view showing a structure of a magnetic leak detection non-destructive sensor according to another embodiment of the present invention, Figure 5a to 5e is a magnetic leakage according to an embodiment of the present invention It is a figure explaining the main steps of the manufacturing method of a flaw detection non-destructive sensor.

As shown in Figure 2 to 5E, non-destructive sensor for magnetic leakage detection and manufacturing method according to an embodiment of the present invention is a sub-magnetic thin film portion 130, the main magnetic thin film portion 140, the magnetic tip portion 145 , Magnetic material layer 145 ′, magnetic thin film portion 148, upper magnetic thin film portion 150, photoresist 160, magnetic layer ML, insulating layer IL, photoresist 160, drawn side 160a, pollutants 170 and 171, and the like.

2 is a cross-sectional view schematically showing the structure of the non-destructive sensor for magnetic leakage inspection according to an embodiment of the present invention, as shown in FIG. 2, the magnetic leak detection non-destructive sensor generates a magnetic field in the micro-cracks of the subject And a magnetic path forming portion for forming a magnetic path of a magnetic field generated by the coil and a coil to which a current is applied. The magnetic path forming unit has an upper portion which forms a magnetic path of the magnetic field together with the main magnetic thin film unit 140 which applies a magnetic field toward the subject to detect the microcracks of the subject that are lifted off the sensor surface by a predetermined distance. The magnetic thin film part 150 and the sub magnetic thin film part 130 which help a magnetic field are connected to the sensor surface end of the main magnetic thin film part 140 are included. Non-destructive sensor for magnetic leak detection is described as a general part having a sensor unit for reading the information of the micro-cracks of the subject.

In the structure of the non-destructive sensor for magnetic leak detection, a magnetic layer and an insulating layer are alternately stacked in at least a portion of the magnetic path forming part to reduce the eddy current generated when a high frequency current is applied to the coil for high sensitivity detection. That is, a structure in which a magnetic layer and an insulating layer are alternately stacked on the main magnetic thin film unit 140 and the upper magnetic thin film unit 150 may be adopted. In addition, the main magnetic thin film portion 140, the magnetic tip portion 145, and the magnetic thin film portion 148, the magnetic thin film portion 148 may be formed by alternately stacking a magnetic layer and an insulating layer.

The sub magnetic thin film part 130 is formed on the lower surface of the main magnetic thin film part 140, and one end thereof is spaced apart from the sensor surface. In addition, the sub magnetic thin film part 130 may be formed by alternately stacking a magnetic layer and an insulating layer.

As the magnetic layer, a material having a saturation magnetic flux density of 1.0 to 2.4 T may be used. For example, any one of CoFe, CoNiFe, CoFeN, FeTaN, FeAlN, and NiFe may be employed. In addition, for example, any one of Al ₂ O ₃ , AlN, SiO ₂ , SiN, TaO, and MgO may be employed as the insulating layer IL. The thickness or the number of alternating layers of the magnetic layer ML and the insulating layer IL may be appropriately determined in consideration of the specific resistance value of the magnetic layer ML, the frequency of the current applied to the coil C, and the like. For example, the number of laminations may be approximately 2 to 16, and the total thickness of the stacked magnetic layers ML may be approximately 0.2 to 1.5, and the thickness of each of the insulating layers IL may be in a range of 10 to 50 microseconds. Can be.

As described above, employing a structure in which the magnetic layer and the insulating layer are alternately stacked in the non-destructive sensor using magnetic leakage inspection is to reduce the eddy current generated at the high frequency. It is known to improve the high frequency characteristics of a magnetic material in a structure in which a magnetic film is laminated with an insulating film interposed therebetween. In other words, when the frequency is more than a certain degree, the permeability drops rapidly, and this frequency is called a roll-off frequency. In the case of a laminated magnetic film, the roll-off frequency is higher than that of a single-layer magnetic film.

3 is a conceptual diagram illustrating a reduction in eddy current in a structure in which a magnetic layer and an insulating layer are repeatedly arranged according to an embodiment of the present invention. As shown in FIG. 3, the main magnetic thin film unit is applied as a high frequency current is applied. The magnetic field inside the 140 or the sub magnetic thin film part 130 is continuously changed in the + Y and -Y directions. If there is a time variation of the magnetic flux, an eddy current (le) is generated that causes the magnetic flux to occur in the direction of preventing such a change. For example, if the magnetic field changes from the + Y direction to the -Y direction, an eddy current that rotates clockwise along the surface side region of the magnetic layer is generated so as to generate a magnetic field in the direction of preventing the change, that is, the + Y direction. Eddy current does not occur in the insulating layer having a high resistivity, and the same phenomenon occurs in each magnetic layer with the insulating layer interposed therebetween.

Therefore, the magnetic flux due to the eddy current in the adjacent region of each magnetic layer is in a direction to cancel each other, and has the effect that the eddy current is substantially reduced.

4 is a cross-sectional view schematically showing the structure of the magnetic leak detection non-destructive sensor according to another embodiment of the present invention, as shown in Figure 4, the present embodiment is a sub-magnetic thin film portion 130 is a main magnetic thin film Only the point formed on the upper surface of the unit 140 is different from the embodiment of FIG. 2, and similarly to the embodiment of FIG. 2, a high frequency recording characteristic is improved by adopting a structure in which magnetic layers and insulating layers are alternately stacked.

The non-destructive sensor for magnetic leak detection is characterized in that a magnetic layer and an insulating layer are alternately stacked in at least a part of a component that serves as a magnetic path forming part in the non-destructive sensor using magnetic leakage inspection, and the rest are examples. It is an enemy. That is, although the magnetic thin film portion 148 of the main magnetic thin film portion 140 and the sub magnetic thin film portion 130 have been described as having a structure in which a magnetic layer and an insulating layer are alternately stacked, the main magnetic thin film portion 140 It may be possible to employ the above structure only in either the magnetic thin film portion 148 or the sub magnetic thin film portion 130. In some cases, it may be applied to the upper magnetic thin film portion 150 or may be applied to the magnetic tip portion 145. In addition, the coil is shown as a structure surrounding the main magnetic thin film portion 140 in the form of a solenoid, but any structure that can apply a recording magnetic field toward the recording medium in the magnetic tip portion 145 of the main magnetic thin film portion 140 This may be possible. For example, the upper magnetic thin film part 150 may be formed in a planar spiral shape.

Hereinafter will be described a method of manufacturing a non-destructive sensor for magnetic leakage inspection according to an embodiment of the present invention.

5A to 5E are views illustrating main steps of a method of manufacturing a non-destructive sensor for magnetic leakage inspection according to an embodiment of the present invention.

Since the non-destructive sensor for magnetic leakage inspection to be described below is characterized in that it includes a structure in which the magnetic layer and the insulating layer of the main magnetic thin film unit 140 are alternately stacked, only the manufacturing method of the main magnetic thin film unit 140 will be described. do. That is, the processes described below are manufactured by the general manufacturing method of the magnetic recording head. The illustration of such a substrate is omitted. Referring to FIG. 5A, first, a magnetic material layer 145 ′ is formed. The magnetic material layer 145 'is formed as a material for making the magnetic tip portion 145 of the main magnetic thin film portion 140, and is formed by depositing or plating a material having a high saturation magnetic flux density. For example, CoFe, CoNiFe, FeTaN, NiFe and the like can be employed, it can be implemented to have a high Bs value by appropriately adjusting the composition ratio of each component.

Next, referring to FIG. 5B, a photoresist 160 having a predetermined pattern according to the shape of the magnetic tip part 145 is formed on the magnetic material layer 145 ′. For example, the pattern of the photoresist 160 may be a bi-layer photoresist pattern, as shown. The formation of the photoresist in the form of a bi-layer is to prevent the material etched in the etching process from contaminating the photoresist 160 to make it difficult to remove the photoresist 160. A portion of the magnetic material layer 145 'is etched using the photoresist 160 as a mask by ion milling or the like to form the magnetic tip portion 145 as shown in FIG. 5C. Contaminants 170 are formed on the upper side surface of the photoresist 160 during etching, but no contamination occurs on the drawn side surface 160a of the photoresist 160.

Referring to FIG. 5D, the magnetic thin film part 148 is stitched to the etched region. That is, the magnetic layer and the insulating layer are alternately stacked in the form of connecting the magnetic tip portion 145. As a magnetic layer, a material having a saturation magnetic flux density of 1.0 to 2.4 T may be used. For example, one or more of CoFe, CoNiFe, FeTaN, and NiFe may be selected and used. As the insulating layer, any one or more of Al ₂ O ₃ , SiO ₂ , SiN, and MgO may be selected and used. The thickness of the insulating layer is approximately 10-50 kHz, and the thickness of the magnetic layer is appropriately determined in consideration of the frequency of the recorded current and the specific resistance value of the material employed as the magnetic layer. In general, as the number of alternating layers of the magnetic layer and the insulating layer increases, the effect of reducing the eddy current increases, but a sufficient number of times may be sufficient depending on the material selection and the frequency. The stacking number is about 2 to 16 times. The total thickness of the stacked magnetic layers is approximately 0.2 to 1.5. Contaminants 171 are formed on the upper and side surfaces of the photoresist 160 when the layers are alternately stacked, but no contamination occurs on the drawn side surfaces 160a of the photoresist 160. The lamination process is finished and the lift off process is performed. At this time, a solution for lifting off the photoresist 160 toward the drawn side surface 160b of the photoresist 160 may permeate well so that the photoresist 160 and the contaminants 170 and 171 may be removed well. have. As a result, as shown in FIG. 5E, the main magnetic thin film part 140 having the magnetic tip part 145 and the magnetic thin film part 148 having a structure in which the magnetic layer and the insulating layer are alternately stacked is formed.

As described above, various substitutions, modifications, and changes can be made by those skilled in the art without departing from the technical spirit of the present invention, and thus, the embodiments and the accompanying drawings are limited. It is not.

1 is a view showing a non-destructive sensor for magnetic leakage inspection using a conventional Hall sensor.

Figure 2 is a schematic cross-sectional view showing the structure of the non-destructive sensor for magnetic leakage inspection in accordance with an embodiment of the present invention.

3 is a conceptual diagram illustrating the reduction of the eddy current in the structure in which the magnetic layer and the insulating layer are repeatedly arranged in accordance with an embodiment of the present invention.

Figure 4 is a schematic cross-sectional view showing the structure of the non-destructive sensor for magnetic leakage inspection in accordance with another embodiment of the present invention.

Figures 5a to 5e is a view for explaining the main steps of the method of manufacturing a non-destructive sensor for magnetic leak detection in accordance with an embodiment of the present invention.

<Description of the symbols for the main parts of the drawings>

130: sub magnetic thin film part 140: main magnetic thin film part

145: magnetic tip portion 145 ': magnetic material layer

148: magnetic thin film portion 150: upper magnetic thin film portion

160: photoresist ML: magnetic layer

IL: insulating layer 160: photoresist

160a: drawn side 170, 171: pollutant

Claims (12)

In the non-destructive sensor for magnetic leakage inspection, In order to detect a minute crack is provided with a coil to which a current is applied to generate a magnetic field and a magnetic path forming portion for forming a magnetic path of the magnetic field generated by the coil, And a portion of the magnetic path forming portion has a structure in which a magnetic layer and an insulating layer are alternately stacked. The method of claim 1, The magnetic path forming portion includes a main magnetic thin film portion having a magnetic layer for applying a magnetic field for detecting the microcracks; Forming a magnetic path together with the main magnetic thin film portion, the magnetic thin film portion having an end portion facing the upper magnetic thin film portion with a predetermined gap therebetween; A sub magnetic thin film portion spaced apart from the magnetic thin film portion in a direction away from the subject having the microcracks so that a magnetic field is connected to the magnetic thin film portion; Non-destructive sensor for magnetic leak detection, characterized in that it comprises a. 3. The method of claim 2, The sub magnetic thin film unit is non-destructive sensor for magnetic leakage, characterized in that formed on the upper or lower surface of the main magnetic thin film unit. 3. The method of claim 2, The main magnetic thin film unit and an upper magnetic thin film unit; A magnetic thin film unit having a structure in which a magnetic layer and an insulating layer are alternately stacked; Non-destructive sensor for magnetic leak detection, characterized in that consisting of. The method of claim 3, The sub magnetic thin film portion is non-destructive sensor for magnetic leakage detection, characterized in that the magnetic layer is laminated alternately with the structure. The method according to any one of claims 1 to 4, The insulation layer is non-destructive sensor for magnetic leak detection, characterized in that formed of any one of Al ₂ O ₃ , SiO ₂ , SiN, MgO. The method according to any one of claims 1 to 5, The magnetic layer is non-destructive sensor for magnetic leak detection, characterized in that formed of any one of CoFe, CoNiFe, FeTaN, NiFe. In the method of manufacturing a non-destructive sensor for magnetic leakage inspection, The magnetic thin film portion and the main magnetic thin film portion composed of a yoke portion having a structure in which the magnetic layer and the insulating layer are alternately stacked, Forming a magnetic material layer (A); Patterning and etching the magnetic material layer according to the shape of the magnetic thin film portion (b); Alternately stacking a magnetic layer and an insulating layer on the etched region; Method of manufacturing a non-destructive sensor for magnetic leak detection, characterized in that it comprises a. The method of claim 8, The step (b) is a method of manufacturing a magnetic leak detection non-destructive sensor, characterized in that carried out using a bi-layer photoresist pattern. The method of claim 8, The magnetic layer is a method of manufacturing a non-destructive sensor for magnetic leakage inspection, characterized in that formed of any one of CoFe, CoNiFe, FeTaN, NiFe. The method of claim 8, The insulating layer is Al ₂ O ₃ , SiO ₂ , SiN, MgO, characterized in that the manufacturing method of the non-destructive sensor for magnetic leak detection, characterized in that. delete

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