JP2007059725A - Magnetic sensor package and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a magnetic sensor package for reducing the number of components, and to provide a manufacturing method of the magnetic sensor package. <P>SOLUTION: The magnetic sensor package 10 comprises a magnetic sensor 12 and a housing 20 that stores the magnetic sensor 12. The housing 20 has a magnetized lid 22 on the detection side of a magnetic body J as a housing component. By allowing the lid 22 to function as a magnet, the lid 22 is given the role of components in a magnetic bias circuit, thus dispensing with having to provide the magnet in the magnetic sensor package as in conventional, and hence reducing the number of components in the magnetic sensor package 10. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a magnetic sensor package used for detecting a magnetic material and a manufacturing method thereof.

  Magnetic sensor packages having a magnetic sensor are widely used. In this magnetic sensor package, the housing is made of a non-magnetic material and includes a magnet for generating a magnetic field. When a magnetic material passes near the package, the magnetic field is disturbed and the amount of magnetic flux detected by the magnetic sensor changes. To do. Based on this change, the magnetic sensor package detects passage or proximity of a magnetic material (see, for example, Patent Document 1).

By the way, the magnetic sensor package has been increasingly reduced in size and weight, and a reduction in the number of parts is desired.
JP 2005-3477 A

  In view of the above facts, an object of the present invention is to provide a magnetic sensor package with a reduced number of parts and a method for manufacturing the same.

  The invention according to claim 1 is a magnetic sensor package used for detecting a magnetic material, comprising: a magnetic sensor; and a housing for housing the magnetic sensor, wherein the housing is provided on a detection side of the magnetic material. The magnet has a magnetized wall member as a housing constituent member.

  Thus, by giving the wall member a function as a magnet, the wall member can serve as a constituent member of the magnetic bias circuit. Therefore, it is not necessary to provide a magnet in the magnetic sensor package as in the prior art. Therefore, it can be set as the magnetic sensor package which reduced the number of parts. In addition, when manufacturing the magnetic sensor package, the step of assembling the magnet can be omitted, so that the manufacturing time can be shortened.

  The invention according to claim 2 is characterized in that the wall member is a lid for sealing the inside of the housing.

  The method of sealing with a lid (LID) may be adhesion with an adhesive, seam welding, soldering, etc., and the sealing method is not particularly limited.

  According to the second aspect of the present invention, the magnetic sensor package can be easily sealed in the housing. Moreover, it is easy to widen the detection surface of the magnetic material with a simple configuration.

  The invention described in claim 3 is characterized in that an IC chip for making a judgment of detection of a magnetic material based on a change in the amount of magnetic flux measured by the magnetic sensor is provided in the housing.

  Thereby, there is no need to provide a judgment means for judging the detection of the magnetic body outside the magnetic sensor package.

  The invention according to claim 4 is the method for manufacturing the magnetic sensor package according to claim 1, wherein when the inside of the housing is sealed by the wall member, the inside of the housing is sealed in an oxygen-free state. It is characterized by that.

  In order to obtain an oxygen-free state, an inert gas atmosphere may be used, or the inside of the housing may be filled with a gel or the like in advance.

  According to the invention described in claim 4, high reliability can be obtained, and output change due to stress can be prevented.

  Since the present invention has the above configuration, the following effects can be obtained.

  According to the first aspect of the present invention, a magnetic sensor package with a reduced number of parts can be obtained. Moreover, since the process of assembling the magnet can be omitted, the manufacturing time can be shortened.

  According to invention of Claim 2, it is easy to seal a magnetic sensor package in a housing. Moreover, it is easy to widen the detection surface of the magnetic material with a simple configuration.

  According to the third aspect of the present invention, there is no need to provide determination means for determining the detection of the magnetic material outside the magnetic sensor package.

  According to the invention described in claim 4, high reliability can be obtained and output change due to stress can be prevented.

  Hereinafter, embodiments will be described and embodiments of the present invention will be described. In the second and subsequent embodiments, the same components as those already described are denoted by the same reference numerals, and description thereof is omitted.

[First Embodiment]
First, the first embodiment will be described. As shown in FIGS. 1 to 3, the magnetic sensor package 10 according to the present embodiment includes a magnetic sensor chip 14 having a magnetic sensor 12 and a magnetic material J based on a change in the amount of magnetic flux measured by the magnetic sensor 12. The housing 20 has a package substrate 18 on which an IC chip 16 for determining detection is mounted.

  A lid (LID) 22 constituting the housing 20 is magnetized to form an N pole and an S pole, and has a function as a magnet. The lid 22 is provided on the detection side of the magnetic body J as a sealing member constituting the housing 20. The housing main body 24 forming the housing portion other than the lid 22 is made of a ceramic member.

  With this configuration, the magnetic sensor chip 14 is magnetically biased. The magnetically biased state means a state in which a constant magnetic field is applied to the magnetic sensor chip 14 by the lid 22.

  When the magnetic body J passes near the lid 22 of the magnetic sensor package 10, the magnetic field formed by the lid 22 is disturbed. Accordingly, a change occurs in the amount of magnetic flux measured by the magnetic sensor 12. The IC chip 16 detects the change in the amount of magnetic flux and determines that the magnetic body J has passed.

  Even when the magnetic body J approaches the lid 22 and stops, the magnetic field remains in the changed state, so that the amount of magnetic flux measured by the magnetic sensor 12 remains in the changed state. Therefore, the IC chip 16 detects this and determines that the state where the magnetic body J is close to the lid 22 is maintained.

  In order to manufacture the magnetic sensor package 10, first, the magnetic sensor chip 14 and the IC chip 16 are mounted on the package substrate 18.

  The housing body 24 is formed by the package substrate 18 on which the magnetic sensor chip 14 and the IC chip 16 are mounted and the side wall member 26. Further, the lid 22 is joined to the housing body 24 by setting the periphery of the housing body 24 to an inert gas atmosphere. This joining is performed by bonding with an adhesive, seam welding, soldering (soldering), or the like.

  Note that the inside of the housing main body 24 may be sealed with a gel-like sealant instead of an inert gas atmosphere.

  As described above, the magnetic sensor package 10 according to this embodiment can cause the lid 22 to function as a component of the magnetic bias circuit by providing the lid 22 with a function as a magnet. Therefore, it is not necessary to provide a magnet in the magnetic sensor package as in the prior art. Therefore, it can be set as the magnetic sensor package 10 which reduced the number of parts. Further, when the magnetic sensor package 10 is manufactured, the process of assembling the magnet can be omitted, so that the manufacturing time can be shortened.

  Further, since the inside of the housing 20 is sealed by the lid 22, the magnetic sensor package 10 can be easily sealed in the housing 20, and the detection surface of the magnetic body J can be easily widened with a simple configuration.

  Further, an IC chip 16 that determines whether to detect the magnetic body J based on a change in the amount of magnetic flux measured by the magnetic sensor 12 is provided in the housing 20. Thereby, it is not necessary to provide a determination means for determining the detection of the magnetic body J outside the magnetic sensor package 10.

  Further, when the magnetic sensor package 10 is manufactured, when the inside of the housing 20 is sealed with the lid 22, the inside of the housing 20 is sealed in an oxygen-free state. As a result, high reliability can be obtained and output change due to stress can be prevented.

[Second Embodiment]
Next, a second embodiment will be described. The magnetic sensor package according to the present embodiment has a lid 32 as shown in FIG. 4 instead of the lid 22 as compared with the first embodiment. Since the lid 32 is made of a ferromagnetic member than the lid 22 described in the first embodiment, the lid 32 can be made thinner than the lid 22. The material of the lid 32 is, for example, neodymium, and the thickness of the lid 32 is, for example, 0.3 mm.

  According to this embodiment, the magnetic sensor package can be further reduced in thickness and weight.

  The embodiments of the present invention have been described above with reference to the embodiments. However, these embodiments are merely examples, and various modifications can be made without departing from the scope of the invention. Needless to say, the scope of rights of the present invention is not limited to the above embodiment.

It is side surface sectional drawing of the magnetic sensor package which concerns on 1st Embodiment (The drawing of a hatch is abbreviate | omitted in the housing main body and a package board | substrate). It is a top view which shows the state before joining a lid | cover with the magnetic sensor package which concerns on 1st Embodiment. FIGS. 3A and 3B are a plan view and a side view, respectively, of a lid constituting the magnetic sensor package according to the first embodiment. FIGS. 4A and 4B are a plan view and a side view, respectively, of a lid constituting the magnetic sensor package according to the second embodiment.

Explanation of symbols

10 Magnetic Sensor Package 12 Magnetic Sensor 16 IC Chip 20 Housing 22 Lid 32 Lid

Claims (4)

A magnetic sensor package used for detecting a magnetic material,
A magnetic sensor;
A housing for housing the magnetic sensor;
With
The housing has a magnetized wall member as a housing component on the detection side of the magnetic material.   The magnetic sensor package according to claim 1, wherein the wall member is a lid for sealing the inside of the housing.   3. The magnetic sensor package according to claim 1, wherein an IC chip that determines whether to detect a magnetic material based on a change in the amount of magnetic flux measured by the magnetic sensor is provided in the housing. 4. It is a manufacturing method of the magnetic sensor package according to claim 1,
A method of manufacturing a magnetic sensor package, wherein when sealing the inside of the housing with the wall member, the inside of the housing is sealed in an oxygen-free state.

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