JP4508920B2 - Magnetic sensor device - Google Patents

Description

The present invention relates to a magnetic sensor device housing the magnetic field sensor element for detecting a change in magnetic field.

  Automatically detects and identifies magnetic recording media, for example, banknotes mixed with magnetic powder in printing ink, such as vending machines such as tickets and ATMs (Automated Teller Machines). In devices that require functions, a magnetic sensor device is used as a device for automatically detecting and identifying a magnetic recording medium.

  In general, a magnetic sensor device is formed by housing a magnetic field sensor element for detecting a change in a magnetic field, together with a magnet for generating a magnetic field (such as an iron-based or ferrite-based permanent magnet), in a magnetic field sensor package.

  Such a magnetic field sensor package is made of an electrically insulating material such as an organic resin, and a magnet mounting portion for mounting a magnet is formed on one main surface, and a mounting portion for a magnetic field sensor element is formed on the other main surface. A substrate, a wiring conductor led out from the mounting portion of the substrate to one main surface, etc., and a metal material whose surface is subjected to wear resistance processing, and is bonded to the outer peripheral portion of the other main surface of the substrate to cover the mounting portion. The thing of the structure which comprises a cover body is known.

  A magnetic field sensor element for detecting a change in magnetic field, such as In-Sb, In-As, or Ge-Si, is mounted on the mounting portion of the magnetic field sensor package, and the electrode is bonded to an exposed portion of the wiring conductor. The magnetic sensor device is electrically connected to the other main surface of the base body through an organic resin adhesive or the like, and then fixed with a lid covering the magnetic field sensor element with a lid. Is configured.

  When the magnetic recording medium is moved along the upper surface of the lid of such a magnetic sensor device, the magnetic field changes with the movement of the magnetic recording medium, and the change of the magnetic field is detected by the magnetic field sensor element. Detection and identification of the recording medium, for example, confirmation of the type of bill is performed.

  The magnetic recording medium is transferred in a state of being placed on a transfer belt (endless belt) or the like, and is sequentially sent to the upper surface of the lid of the magnetic sensor device arranged at the same height as the transfer surface of the transfer belt.

The reason why the lid is formed of a metal material or the like that has been subjected to wear resistance processing is to make the surface of the lid as smooth as possible and to move the magnetic recording medium smoothly.
JP 2003-177169 A Japanese Patent Laid-Open No. 8-233843

  However, in the above-described conventional magnetic sensor device, since the lid is made of a metal material, the upper surface of the lid tends to wear due to contact with the magnetic recording medium during use, and the lid is used well over a long period of time. There was a problem that it was difficult.

  In the conventional magnetic sensor device described above, the lid made of a metal material and the substrate made of an epoxy resin or the like are bonded with an organic resin adhesive. There was also a problem that it could not be kept high.

  The present invention has been devised in view of the above-described problems, and its purpose is to satisfactorily hermetically seal a magnetic field sensor element and to perform good detection and identification of a magnetic recording medium over a long period of time. It is an object of the present invention to provide a magnetic sensor package and a magnetic sensor device that are capable of performing the above-described and have excellent long-term reliability.

Magnetic sensor device of the present invention, the internal coiled conductor pattern is provided on, the mounting portion in which the magnetic field sensor element is mounted on one main surface, which is electrically connected to the coiled conductor to the other main surface a substrate made of a ceramic sintered body having a second connecting pad electrically connected to the first connection pad and the magnetic field sensor element, and wherein the magnetic field sensor element mounted on the mounting portion, the magnetic field sensor element the Ri Na and a hermetic seal to order ceramic lid which is attached on one main surface of the substrate, while functions as an electromagnet by supplying an electric current to the coil-shaped conductor on the upper surface of the lid The magnetic recording medium is moved along the magnetic recording medium, and a change in the magnetic field generated between the magnetic information of the magnetic recording medium and the electromagnet is detected by the magnetic field sensor element .

Further, magnetic sensor device of the present invention having the above structure, the lid is characterized in that it has the following top 0.5μm in arithmetic average roughness (Ra).

Further, magnetic sensor device of the present invention having the above structure, in that it consists conductive material wiring conductor for connecting the magnetic sensor element and the second connecting pad electrically is mainly composed of non-magnetic metal It is a feature.

Furthermore, magnetic sensor device of the present invention having the above structure, the said and electrode pads to be bonded is provided to the magnetic field sensor element on one main surface of the substrate, the electrode pads 3 wt% to 10 wt% It is formed by the nickel plating layer which contains phosphorus in the ratio of this.

Further, the magnetic sensor device of the present invention is characterized in that, in the above-described configuration, a chamfered portion is provided at an upper corner portion of the lid located upstream in the moving direction of the magnetic recording medium.

Furthermore, the magnetic sensor device of the present invention is characterized in that, in the above configuration, the chamfered portion has a cross-sectional arc shape with a radius of curvature of 0.05 mm to 1 mm.

According to the magnetic sensor apparatus of the present invention, the coil-shaped conductor pattern is provided on the inner portion, the mounting portion in which the magnetic field sensor element is mounted on one main surface, which is electrically connected to the coiled conductor to the other main surface air and base made of ceramic sintered body having a second connecting pad electrically connected to the first connection pads and the magnetic field sensor element, a magnetic field sensor element mounted on the mounting portion, the magnetic sensor element A ceramic lid attached to one main surface of the base for hermetic sealing, and a magnetic recording medium is formed along the upper surface of the lid while energizing the coiled conductor to function as an electromagnet. Since the magnetic field sensor element detects a change in the magnetic field generated between the magnetic information of the magnetic recording medium and the electromagnet by moving the coiled conductor through the first connection pad, the magnetic field Can generate , A change in the magnetic field by detecting the magnetic field sensor element, detection of the magnetic recording medium to be moved along the lid top, identifying the possible row of Ukoto.

  In this case, since the lid made of ceramic is superior in wear resistance compared to the lid made of a metal material, the amount of wear is extremely small even when used repeatedly over a long period of time, and the magnetic recording medium is placed along the upper surface of the lid. It can be moved stably.

Further, according to the magnetic sensor apparatus of the present invention, in addition to the cover body as described above, by forming the substrate in ceramic, it is firmly and well junction with each other via the two brazing material, glass, or the like The sealing reliability of the magnetic field sensor element can be made extremely excellent.

Furthermore, according to the magnetic sensor apparatus of the present invention, by forming a 0.5μm or less smooth surface arithmetic mean roughness upper surface of the lid (Ra), more along the magnetic recording medium on the upper surface of the lid It can be moved smoothly, and the detection accuracy and identification accuracy of the magnetic recording medium can be improved.

Furthermore, according to the magnetic sensor apparatus of the present invention, the wiring conductors for electrically connecting the magnetic field sensor element and the second connection pad, by forming a non-magnetic metal with a conductive material mainly, order to improve the mechanical strength of the substrate, effectively prevent the occurrence of cracks, it is possible to further enhance the sealing reliability of the magnetic sensor device.

  Furthermore, in this case, since the wiring conductor is non-magnetic, it is possible to more effectively prevent the magnetic field from changing due to the presence of the wiring conductor through which the magnetic detection electric signal is transmitted in the magnetic field. In addition, the magnetic recording medium can be detected and identified with higher accuracy.

Furthermore, according to the magnetic sensor apparatus of the present invention, a substrate made of a ceramic sintered body, and a wiring conductor made of metallized layers, for example, previously coated with a metal paste for forming the metallized layer on the unfired substrate Since it can be formed by simultaneous firing, the bonding between the substrate and the wiring conductor can be strengthened, and the long-term reliability can be further improved.

Furthermore, according to the magnetic sensor apparatus of the present invention, provided with an electrode pad that is bonded to the magnetic field sensor element on one main surface of the substrate, containing phosphorus the electrode pad at a ratio of 3 wt% to 10 wt% by forming a nickel plating layer, it is possible to improve the bonding property with respect to the electrode pads, the electrode of the magnetic sensor element with respect to the electrode pads can be bonded more reliably.

Furthermore, according to the magnetic sensor apparatus of the present invention, by setting the content of phosphorus in the nickel plating layer 3 wt% to 10 wt%, to lower the crystallinity of the nickel plating layer by the action of phosphorus component And non-magnetic.

  As a result, the bondability of the electrode pad can be made even better, the magnetism can be kept small, and the electric signal detected by the magnetic field sensor element according to the change of the magnetic field can be generated more without causing noise or the like. It can be reliably transmitted to an external electric circuit.

According to the magnetic sensor device of the present invention , the coiled conductor pattern is provided inside, and the mounting portion on which the magnetic field sensor element is mounted on one main surface is electrically connected to the coiled conductor on the other main surface. A base made of a ceramic sintered body having a second connection pad electrically connected to the first connection pad and the magnetic field sensor element, a magnetic field sensor element mounted on the mounting portion, and the magnetic field sensor element And a ceramic lid attached on one main surface of the substrate for hermetic sealing, and a magnetic recording medium along the upper surface of the lid while energizing the coiled conductor to function as an electromagnet The magnetic field sensor element detects the change in the magnetic field generated between the magnetic information of the magnetic recording medium and the electromagnet and interprets it. Therefore, the magnetic field sensor element is sealed very well. I can do it , Detection of stable magnetic recording medium for a long time, identification Ki out a row of Ukoto can provide excellent magnetic sensor device in long-term reliability.

  In addition, according to the magnetic sensor device of the present invention, magnetic recording that has been transferred on a transfer belt or the like by providing a chamfered portion at the upper surface corner of the lid located upstream in the moving direction of the magnetic recording medium. The medium is unlikely to be caught by the edge of the lid, and the magnetic recording medium can be smoothly run along the surface of the lid.

  Furthermore, according to the magnetic sensor device of the present invention, the chamfered portion has an arcuate cross section with a radius of curvature of 0.05 mm to 1 mm, so that the magnetic recording medium transferred on the transfer belt or the like is covered with the lid. Problems such as being caught on the edge can be prevented more effectively.

  Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

Figure 1 is a sectional view showing an example of an embodiment of magnetic sensor device of the present invention. In Figure 1, 1 is a substrate, 2 is the electrode pads, the 4 first connection pads, the 5 second connection pads, 6 lid, 7 is a magnetic field sensor element, these substrates 1, a first connection pad 4, the second connection pad 5, magnetic sensor device 9 by the cover member 6 and the magnetic field sensor element 7 is essentially constructed.

  The substrate 1 is made of a ceramic material such as an aluminum oxide sintered body, a glass ceramic sintered body, an aluminum nitride sintered body, a mullite sintered body, or a ceramic composite material formed by bonding ceramic powder with an organic resin. It is formed.

  If such a substrate 1 is made of, for example, an aluminum oxide sintered body, raw powders such as aluminum oxide and silicon oxide are formed into a sheet shape together with an organic solvent and a binder to obtain a plurality of green sheets, It is manufactured by subjecting this to appropriate drilling, laminating it vertically, and firing it at about 1600 ° C.

  The base body 1 is provided with a coiled conductor 1a and has a mounting portion 1b for the magnetic field sensor element 7 on one main surface.

  In addition, the base 1 has a first connection pad 4 electrically connected to the coiled conductor 1a and a second connection pad 5 electrically connected to the magnetic field sensor element 7 on the other main surface. is doing.

  A coiled conductor 1a formed inside the substrate 1 functions as an electromagnet when energized, and a magnetic field sensor detects changes in the magnetic field due to the movement of a magnetic recording medium (to be described later) in the magnetic field generated by the electromagnet. By sequentially detecting with the element 7, the magnetic information of the magnetic recording medium is read.

  In order to energize the coiled conductor 1a, the first connection pad 4 is electrically and mechanically connected to a power feeding terminal of the external electric circuit board via solder or the like, and an external current is supplied to the first connection pad. 4 through the coiled conductor 1a.

  The electrical connection between the coiled conductor 1a and the first connection pad 4 is performed, for example, by forming the wiring conductor 3 from the coiled conductor 1a to the first connection pad 4 inside the base body 1. be able to. The wiring conductor 3 may be formed on the surface of the base 1.

  The magnetic field sensor element 7 has a function of detecting a change due to the external magnetism of the magnetic field generated by the coiled conductor 1a and transmitting an electric signal in accordance with the change. This electric signal is transmitted to an external electric circuit (not shown) through the second connection pad 5 electrically connected to the magnetic field sensor element 7.

  As the magnetic field sensor element 7, a semiconductor material having a high electron mobility such as In—Sb, In—As, or Ge—Si is used.

  The electrical connection between the magnetic field sensor element 7 and the second connection pad 5 is formed, for example, by leading out the wiring conductor 3 from the second connection pad 5 to one main surface of the base 1, and then leading out the wiring conductor 3. This can be done by electrically connecting the electrode of the magnetic field sensor element 7 to the portion via a conductive connecting material such as a bonding wire 8 or a metal bump (not shown).

  In order to make the connection to the wiring conductor 3 such as the bonding wire 8 easy and strong, it is preferable to provide the electrode pad 2 on one main surface of the substrate 1 (such as a lead-out portion of the wiring conductor 3).

  The electrode pad 2 is preferably formed in a shape, size, etc. suitable for connection of the bonding wire 8 or the like, such as a rectangular shape, a circular shape, or an elliptical shape.

  Then, the electrode of the magnetic field sensor element 7 mounted on the mounting portion 1b is electrically connected to the electrode pad 2 via a conductive material such as a bonding wire 8, and the second connection pad 5 is connected to an external electric circuit. By electrically connecting to a predetermined portion via solder or the like, the electrode of the magnetic field sensor element 7 is electrically connected to an external electric circuit via the electrode pad 2, the wiring conductor 3, and the second connection pad 5. Then, an electric signal is transmitted from the magnetic field sensor element 7 to an external electric circuit.

  These coiled conductor 1a, electrode pad 2, wiring conductor 3, first connection pad 4 and second connection pad 5 are formed of a metal material such as tungsten, molybdenum, copper, silver, or palladium. The metal material can be formed in the form of a conventionally known metallized layer, plating layer, vapor deposition layer, or the like.

  The coiled conductor 1a, the electrode pad 2, the wiring conductor 3, the first connection pad 4 and the second connection pad 5 are preferably formed of the same metal material in consideration of productivity, and are made of a metallized layer of tungsten. In this case, a metal paste prepared by kneading tungsten powder together with an organic solvent and a binder is printed on a green sheet as a substrate 1 on a predetermined coil pattern or circuit pattern by screen printing. It is formed by.

  For example, when the base body 1 is formed of a laminated body in which a plurality of insulating layers (such as a ceramic layer obtained by firing green sheets) are laminated, the coiled conductor 1a has a coiled conductor interposed between the plurality of layers. Above, they are formed by connecting them in series between the upper and lower layers. In this case, a stronger magnetic field can be generated by increasing the number of turns of the coil with the planar area of the substrate 1 being reduced. The pattern between the layers may be a single circle.

  The coiled conductor 1a is preferably positioned on the upper side of the base 1 near the mounting portion 1b in order to effectively apply a magnetic field to the magnetic field sensor element 7.

  The electrode pad 2, the wiring conductor 3, the first connection pad 4 and the second connection pad 5 are preferably coated with a plating layer such as nickel or gold on the exposed surfaces. Thereby, oxidative corrosion can be prevented more effectively, and the bonding property of the bonding wire 8 and the wettability of the solder can be improved.

  The mounting portion 1b on which the magnetic field sensor element 7 is mounted is hermetically sealed by a ceramic lid body 6.

  As the ceramic forming the lid body 6, an aluminum oxide sintered body, a glass ceramic sintered body, an aluminum nitride sintered body, a mullite sintered body, or the like is used.

  When the lid 6 is made of, for example, an aluminum oxide sintered body, a raw material powder such as aluminum oxide and silicon oxide is formed into a sheet shape together with an organic solvent and a binder to form a green sheet. It is manufactured by firing at about 1600 ° C. after cutting.

  When a magnetic recording medium such as banknotes is moved along the upper surface (exposed main surface) of the lid 6 as described above, the magnetic field changes, and the magnetic field sensor element 7 detects the change in the magnetic field. The medium is detected and identified.

  In this case, since the lid body 6 made of ceramics is superior in wear resistance as compared with the lid body made of metal, the amount of wear is extremely small even when used for a long time, and the magnetic recording medium is placed along the upper surface of the lid body. It can be moved stably.

  In addition to the lid 6 described above, the substrate 1 is also made of ceramic, so that both can be firmly and well bonded to each other via a brazing material, glass or the like, and the magnetic field sensor element 7 is sealed. The reliability can be made extremely excellent.

  As the ceramic forming the lid body 6, it is preferable to use an aluminum oxide sintered body because it needs to be excellent in wear resistance.

  In addition, the base 1 and the lid 6 prevent the occurrence of thermal stress due to the difference in thermal expansion coefficient between them, and make the bonding between them stronger and more excellent in long-term reliability. It is preferable to form with the same material.

  The lid 6 preferably has an upper surface roughness of 0.5 μm or less in arithmetic average roughness (Ra), and the upper surface of the lid 6 is 0.5 μm in arithmetic average roughness (Ra). By providing the following smooth surface, the magnetic recording medium can be moved more smoothly along the upper surface of the lid 6 and the detection accuracy and identification accuracy of the magnetic recording medium can be improved.

  In order to reduce the surface roughness of the upper surface of the lid body to 0.5 μm or less in terms of arithmetic average roughness (Ra), for example, a method of performing mechanical polishing on the upper surface of the lid body 6 is used.

  Note that even if the surface roughness of the upper surface of the lid 6 is less than 0.005 μm in arithmetic mean roughness (Ra), there is almost no change in the above-mentioned effectiveness, and conversely it is necessary for processing such as polishing. There is a risk that productivity will be reduced due to longer time. Therefore, the surface roughness of the lid 6 is more preferably set in the range of 0.005 μm to 0.5 μm in terms of arithmetic average roughness (Ra).

  On the other hand, regarding the lower surface of the lid body 6, it is preferable that the surface roughness of the portion bonded to the base body 1 is 1 μm or more in terms of arithmetic average roughness (Ra). Thereby, when joining the cover body 6 and the base | substrate 1 with joining materials, such as a brazing material and glass, both can be joined very firmly by an anchor effect.

  In order to set the surface roughness of the lower surface of the lid body 6 to be bonded to the base 1 to 1 μm or more in terms of arithmetic average roughness (Ra), for example, the bottom surface of the lid body 6 is subjected to a roughening process such as sandblasting. The method of giving etc. can be used.

Further, magnetic sensor device 9 described above, the substrate 1 is formed of a ceramic sintered body such as sintered aluminum oxide, wiring conductors for electrically connecting the magnetic sensor element 7 and the second connection pad 5 3 is preferably Rukoto formed of a conductive material mainly composed of non-magnetic metal.

  In this case, since the mechanical strength of the substrate 1 is improved, the occurrence of cracks and the like can be effectively prevented, and the sealing reliability of the magnetic sensor device can be further enhanced.

  Further, since the coiled conductor portion 1a and the wiring conductor 3 are non-magnetic, it is effective to cause a change in the magnetic field due to the presence of the wiring conductor 3 through which a relatively weak electric signal is transmitted in the magnetic field. Therefore, the magnetic recording medium can be detected and identified with higher accuracy.

  Furthermore, in this case, the base 1 made of a ceramic sintered body, the coiled conductor portion 1a made of a metallized layer, and the wiring conductor 3 are formed by, for example, applying a metal paste that becomes a metallized layer to an unfired base (green sheet). Since it can be formed by simultaneous firing, the bonding between the base body 1 and the coiled conductor portion 1a and the wiring conductor 3 can be strengthened, and the long-term reliability is further improved. can do.

  The ceramic sintered body is a ceramic sintered body such as an aluminum oxide sintered body, a glass ceramic sintered body, an aluminum nitride sintered body, or a mullite sintered body.

  As the nonmagnetic metal, a metal material such as tungsten or molybdenum, or a metal material such as an alloy thereof can be used.

  Similarly, the wiring conductor 3 that electrically connects the coiled conductor 1a and the first connection pad 4 is preferably made of a conductive material mainly composed of a non-magnetic metal, and the like. In view of the above, it is more preferable that the magnetic field sensor element 7 and the second connection pad 5 are formed of the same conductive material as that for electrically connecting.

Further, as described above, the electrode pad 2 to be bonded to the magnetic field sensor element 7 is preferably formed on one main surface of the substrate 1 (such as the lead-out portion of the wiring conductor 3). It is preferable that the nickel plating layer has a phosphorus content of 3 mass% to 10 mass%. In this case, to improve the bondability to the electrode pad 2, with respect to the electrode of the electrode pads 2 of the magnetic field sensor element 7, it is possible to bond more securely, also, the nickel plating layer by the action of phosphorus component Crystallinity can be reduced to make it nonmagnetic. Thereby, magnetism is suppressed small, and the electric signal detected by the magnetic field sensor element 7 according to the change of the magnetic field can be transmitted to the external electric circuit more reliably without causing almost any noise or the like.

  Here, when the phosphorus content is less than 3% by mass, the nickel plating layer has magnetism, and noise easily occurs when transmitting an electric signal. When the content exceeds 10% by mass, the internal stress of the nickel plating layer May increase and the bonding strength of the plating layer to the electrode pad 2 may be insufficient.

  The electrode pad 2 does not need to be formed only by the nickel plating layer. For example, a metallized layer made of the same metal material as the wiring conductor 3 is formed in a predetermined shape and size of the electrode pad 2. In addition, a nickel plating layer may be formed thereon. In this case, the thickness of the metallized layer (several tens of μm) is thicker than the thickness of the plating layer (less than 1 μm to about several tens of μm) and is firmly attached to the surface of the substrate 1 (by simultaneous firing). Therefore, the bondability of the electrode pad 2 can be improved.

  The exposed surface of the nickel plating layer may be covered with a gold plating layer (not shown) to prevent oxidative corrosion.

  If the wiring conductor 3, the first connection pad 4, and the second connection pad 5 are also covered with the same nickel plating layer as that of the electrode pad 2, the generation of noise or the like can be prevented more reliably. In addition, since the accuracy of detection and identification of the magnetic recording medium can be further increased, it is even more preferable.

A magnetic field sensor element 7 is bonded to the mounting portion 1b via a brazing material, glass, an organic resin adhesive, or the like, and an electrode of the magnetic field sensor element 7 is electrically connected to the electrode pad 2 via a bonding wire 8. The magnetic sensor device 9 is configured by connecting them together and covering the mounting portion 1b with the lid 6.

The magnetic sensor device 9 reads the magnetic information of the magnetic recording medium moving along the upper surface of the lid 6 by detecting the magnetic field change caused by the electromagnet generated by energizing the coiled conductor 1a with the magnetic field sensor element 7. .

  That is, by sequentially detecting the magnetic field generated between the electromagnet and the magnetic recording medium as the magnetic recording medium moves, the magnetic information on the magnetic recording medium is sequentially detected.

  In order to feed the magnetic recording medium to the upper surface of the lid 6, for example, a transfer belt (endless belt or the like) (not shown) is arranged so that the upper surface of the lid 6 and the transfer surface are at the same height. In addition, a method of sequentially transferring and feeding the magnetic recording medium from the transfer belt is used.

  The detected change in the magnetic field is converted into an electric signal by the magnetic field sensor element 7 and transmitted to an external electric circuit via the wiring conductor 3. With the transmitted electrical signal, operations such as ticket sales are performed in a device (such as a vending machine) incorporating an external electrical circuit.

  Further, it is preferable to provide a chamfered portion 6a at the upper surface corner portion of the lid body 6 located on the upstream side in the moving direction of the magnetic recording medium. In this case, the magnetic recording medium transferred on the transfer belt or the like is unlikely to be caught by the edge of the lid 6, and the magnetic recording medium can be smoothly run along the surface of the lid 6. .

  The chamfered portion 6b is preferably formed to have a circular arc shape with a curvature radius of 0.05 mm to 1 mm.

  By forming such chamfered portions 6 a and 6 b, it is possible to more effectively prevent a problem that the magnetic recording medium transferred on the transfer belt or the like is caught on the edge of the lid 6.

  The chamfered portions 6a and 6b are formed by chamfering a corner portion between the upper surface and the side surface of the lid 6 by a processing means such as polishing or cutting. Such processing may be formed by chamfering the corresponding corner of the ceramic green sheet when the lid 6 made of ceramic is manufactured by laminating ceramic green sheets.

  In this case, the width of the chamfered portion 6a is set to a range of 0.05 mm to 1 mm, or the radius of curvature of the chamfered portion 6b is set to 0.05 mm to 1 mm so that the chamfered portions 6a and 6b are sufficiently large in magnetic recording. Smooth movement of the medium can be ensured, and the chamfered portions 6a and 6b can be easily processed and formed, so that the productivity of the magnetic sensor device can be improved.

  In the present invention, the upper surface of the lid 6 may be a curved surface such as a convex arc. In this case, it is possible to further prevent the magnetic recording medium from being caught on the upper surface or corners of the lid 6.

Further, the chamfered portions 6a, 6b is because it is easy to radius of curvature forms processed form, it may be chamfered portion 6a, the formation of 6b to better ensure easy production of the magnetic sensor device 9.

  The base body 1 and the lid body 6 are formed of an aluminum oxide sintered body, the surface roughness of the lid body 6 is changed as shown in Table 1, and the magnetic recording medium is moved along the upper surface of the lid body 6. The presence or absence of defects such as scratches on the magnetic recording medium was confirmed.

  The roughness of the upper surface of the lid 6 is adjusted by the roughness of the polishing plate for surface polishing, and the roughness is measured using a general surface roughness meter that measures the roughness by mechanical contact. It was.

  Bills were used as the magnetic recording medium.

After the banknote was moved 1000 times along the upper surface of the lid body 6, it was visually confirmed whether or not the surface of the banknote had scratches that would interfere with magnetic reading.

  As can be seen from the results in Table 1, when the roughness of the upper surface of the lid body 6 exceeds 0.5 μm in arithmetic average roughness (Ra), there is a problem that the magnetic recording medium to be detected is damaged. .

In contrast, the upper surface roughness of the cover 6 is 0.5μm or less in terms of arithmetic average roughness (Ra), is within the scope of the present invention, did not scratch occurs in the bill. Moreover, the banknote could be reliably and smoothly moved along the upper surface of the lid body 6. The polishing cost, ie cheaper cost of the magnetic sensor device 9.

  Therefore, it is necessary for the lid 6 to have a surface roughness in terms of arithmetic average roughness (Ra) as follows, and is preferably in the range of 0.005 μm to 0.5 μm.

Further, in the case where Ra on the upper surface of the lid 6 is 0.3 μm, a flat chamfered portion 6 a having a certain width is formed at the corner between the upper surface and the side surface of the lid 6, and an arc shape And a magnetic recording medium is transferred to the upper surface of the lid body 6 via a transfer belt, and the magnetic recording medium is smoothly transferred without being caught at the corners of the lid body 6. Confirmed whether or not. The number of tests is 1000 for each condition.

  From Tables 2 and 3, when the width of the chamfered portion 6a is in the range of 0.05 to 1 mm and the radius of curvature of the chamfered portion 6b is in the range of 0.05 to 1 mm, the magnetic recording medium covers the upper surface of the lid 6 without any problem. I was able to move it. Further, when the width of the chamfered portion 6a is less than 0.05 mm, or when the radius of curvature of the chamfered portion 6b is less than 0.05 mm, the magnetic recording medium is completely caught by the corner portion of the lid 6 and stopped. Although no major problems occurred, the phenomenon that the movement of the magnetic recording medium stagnated at the corners was observed about once or twice. Further, when the width of the chamfered portion 6a exceeds 1 mm, or when the radius of curvature of the chamfered portion 6b exceeds 1 mm, the time required for processing the chamfered portions 6a and 6b becomes longer, and the productivity tends to decrease. It was.

  Accordingly, the lid body 6 is formed with a chamfered portion 6a having a width of 0.05 mm to 1 mm at a corner between the upper surface and the side surface, or an arc-shaped chamfered portion 6b having a cross-sectional curvature radius of 0.05 mm to 1 mm. It has been found that it is preferable to form

  The present invention is not limited to the above-described embodiments and examples, and various modifications and improvements can be made without departing from the scope of the present invention.

  For example, a metallization layer (not shown) for brazing is formed of a metal material similar to that of the wiring conductor 2 along the surfaces of the lower surface of the lid 6 and the upper surface of the base body 1 that are joined to each other. You may make it improve wettability and improve the joint strength of the base | substrate 1 and the cover body 6 through a brazing material.

An example of an embodiment of a magnetic sensor apparatus of the present invention is a cross-sectional view illustrating.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Base | substrate 1a ... Coil-shaped conductor part 1b ... Mounting part 2 ... Electrode pad 3 ... Wiring conductor 4 ... 1st connection pad 5 ... 2nd connection pad 6 ... lid 6a, 6b ... chamfered portion 7 ... magnetic sensor element 9 ... magnetic sensor device

Claims (6)

A mounting portion in which a coiled conductor pattern is provided, a magnetic field sensor element is mounted on one main surface, a first connection pad electrically connected to the coiled conductor on the other main surface, and the magnetic field sensor element to a substrate made of a ceramic sintered body having a second connecting pad electrically connected to said magnetic field sensor element mounted on the mounting portion, of the substrate so as to hermetically seal the said magnetic field sensor element Ri Na and a ceramic lid which is attached on one main surface, while functions as an electromagnet by supplying an electric current to the coil-shaped conductor, by moving the magnetic recording medium along the upper surface of the lid , magnetic sensor device you characterized in that the change in the magnetic field was set to be detected by the magnetic field sensor element generated between the magnetic information of the magnetic recording medium electromagnet. Magnetic sensor device according to claim 1, characterized in that the lid has the following top 0.5μm in arithmetic average roughness (Ra). According to claim 1 or claim 2, characterized in that the wiring conductors connecting the front Symbol field sensor element and the second connecting pad electrically is made of a conductive material shall be the main component non-magnetic metal magnetic sensor device. An electrode pad bonded to the magnetic field sensor element is provided on one main surface of the substrate, and the electrode pad is formed of a nickel plating layer containing phosphorus at a ratio of 3 mass% to 10 mass%. magnetic sensor device according to any one of claims 1 to 3, characterized in. The magnetic sensor device according to any one of claims 1 to 4, characterized in that the chamfered portion is provided on the upper surface corner portion of the lid located in the moving direction upstream side of the magnetic recording medium. 6. The magnetic sensor device according to claim 5 , wherein the chamfered portion has a circular arc shape with a radius of curvature of 0.05 mm to 1 mm.

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