WO2017038388A1

WO2017038388A1 - Magnetic field detection device

Info

Publication number: WO2017038388A1
Application number: PCT/JP2016/073241
Authority: WO
Inventors: 聖司西本; 智之滝口; 河野　禎之; 水谷　彰利
Original assignee: 株式会社デンソー
Priority date: 2015-08-28
Filing date: 2016-08-08
Publication date: 2017-03-09

Abstract

This magnetic field detection device has an IC package (20), a terminal (30), and a resin molded body (40). The IC package has a magnetic detection element (21), a lead frame (22) positioned on the first side of the magnetic detection element, and a resin material (23) covering the magnetic detection element and the lead frame. The terminal is connected to the lead frame of the IC package. The resin molded body has a base section (41) and a head section (42). The base section covers a connection area where the lead frame and the terminal are connected to each other. The head section covers the magnetic detection element of the IC package. The head section has the thickest portion. The outer wall surface of the thickest portion positioned on the second side of the magnetic detection element is defined as a detection-side reference surface (48). An element-corresponding surface (24) positioned on the second side, said element-corresponding surface being the outer wall surface of the IC package, is exposed from the resin molded body, or covered with a detection-side thin portion (46) that is thinner than a thickness (T4) from the element-corresponding surface to the detection-side reference surface.

Description

Magnetic field detector

Cross-reference of related applications

This application includes Japanese Patent Application No. 2015-168767 filed on August 28, 2015, and Japanese Patent Application No. 2016- filed on June 13, 2016, the disclosures of which are incorporated herein by reference. Based on 116888.

The present disclosure relates to a magnetic field detection device.

Conventionally, a magnetic field detector that outputs a signal corresponding to the direction of the magnetic field is known.

The magnetic field detection device described in Patent Document 1 is used as a rotation angle sensor that detects the rotation angle of a throttle valve provided in an electronically controlled throttle that controls the intake air amount to the engine. In this magnetic field detection device, a housing cover of an electronically controlled throttle, two columns extending from the housing cover, and two IC packages inserted between the two columns are integrally molded with a resin body. It is constituted by.

Japanese Patent No. 5517083

Patent Document 1 discloses injecting an ultraviolet curable resin or heat-melted hot melt into a mold on which an IC package is fixed. However, due to the difference in linear expansion between the injected resin material and the IC package, a stress may be generated in the magnetic detection element in the IC package when the temperature changes, and an error may occur in the output signal. As a result, the detection accuracy of the rotation angle of the throttle valve by the magnetic field detection device may be reduced.

This indication is made in view of the above-mentioned point, and it aims at providing the magnetic field detection apparatus which can reduce the stress resulting from the linear expansion difference generated at the time of a temperature change, and can raise detection accuracy. To do.

The magnetic field detection device according to the first aspect of the present disclosure includes an IC package, a terminal, and a resin mold body. The IC package includes a magnetic detection element that outputs a signal according to the direction of the magnetic field, a lead frame that is located on the first side of the magnetic detection element and is connected to the magnetic detection element, and the magnetic detection element and the lead frame. And a resin material to be coated. The terminal is connected to a portion of the lead frame of the IC package that protrudes from the resin material. The resin mold body has a base portion and a head portion, and covers the IC package and a part of the terminal. The base portion covers a portion including a connection portion between the lead frame and the terminal. The head protrudes from the base portion toward the side opposite to the terminal, and covers a portion including the magnetic detection element of the IC package. The head has a maximum thickness portion of the head where the thickness from the IC package surface is maximum. The outer wall surface of the maximum thickness portion located on the second side of the magnetic detection element, which is opposite to the first side, is defined as the detection side reference surface. The element corresponding surface, which is the outer wall surface of the IC package located on the second side, is exposed from the resin mold body, or is thinner than the thickness from the element corresponding surface to the detection side reference surface in the resin mold body. It is covered with the detection side thin part which has.

Thereby, since the stress acting on the element corresponding surface of the IC package from the resin mold body due to the difference in linear expansion at the time of temperature change is reduced, it is possible to suppress the occurrence of an error in the output signal of the magnetic detection element. Further, since the resin mold body molds the IC package and a part of the terminal, the positional relationship between them is fixed, so that the detection accuracy of the magnetic field detection device can be improved.

Here, when the resin mold body does not mold the element corresponding surface, that is, when the element corresponding surface is exposed from the resin mold body, the inner wall of the mold forming the resin mold body and the element corresponding surface are The resin mold body can be injection-molded in the contacted state. Thereby, the positioning accuracy of the IC package is improved, and the detection accuracy of the magnetic field detection device can be increased.

On the other hand, when the element-corresponding surface is covered with the detection-side thin portion of the resin mold body, the resin mold body is not in contact with the inner wall of the mold forming the resin mold body and the element-corresponding surface. Injection molded. Thereby, it is possible to ease the required accuracy of the mold.

It is sectional drawing of the electronically controlled throttle in which the magnetic field detection apparatus by 1st Embodiment of this indication is used. It is a perspective view of the magnetic field detection apparatus by 1st Embodiment. It is a front view of the magnetic field detection apparatus in the III direction of FIG. It is a top view of the magnetic field detection apparatus in the IV direction of FIG. FIG. 5 is a sectional view taken along line VV in FIG. 3. It is a characteristic view of the signal output from the magnetic field detection apparatus of 1st Embodiment. It is a top view of the magnetic field detection apparatus by a 2nd embodiment of this indication. FIG. 8 is a sectional view taken along line VIII-VIII in FIG. It is a top view of the magnetic field detection apparatus by a 3rd embodiment of this indication. FIG. 10 is a sectional view taken along line XX in FIG. 9. It is a top view of the magnetic field detection apparatus by a 4th embodiment of this indication. FIG. 12 is a cross-sectional view taken along line XII-XII in FIG. 11.

Hereinafter, a plurality of modes for carrying out the present disclosure will be described with reference to the drawings. In each embodiment, parts corresponding to the matters described in the preceding embodiment may be denoted by the same reference numerals, and redundant description may be omitted. When only a part of the configuration is described in each mode, the other modes described above can be applied to the other parts of the configuration. Not only combinations of parts that clearly show that combinations are possible in each embodiment, but also combinations of the embodiments even if they are not explicitly stated unless there is a problem with the combination. Is also possible.

Hereinafter, a plurality of embodiments of the present disclosure will be described with reference to the drawings.

(First embodiment)
A first embodiment of the present disclosure is shown in FIGS. The magnetic field detection device 1 of the first embodiment is used, for example, for an electronically controlled throttle 2 that controls the intake air amount to the engine of a vehicle. The magnetic field detection device 1 outputs a signal corresponding to the rotation angle of a throttle valve 3 as a detection object provided in the electronic control throttle 2.

First, the schematic configuration of the electronic control throttle 2 will be described.

As shown in FIG. 1, the electronic control throttle 2 includes a throttle valve 3, a housing 4, a magnetic field forming unit 5, a housing cover 6, a magnetic field detection device 1, and the like.

The housing 4 is formed with an intake passage 7 for introducing air into the engine. A throttle valve 3 formed in a substantially disc shape is provided in the intake passage 7. The throttle valve 3 is fixed to the valve shaft 8. Both ends of the valve shaft 8 are rotatably supported by the housing 4. As a result, the throttle valve 3 can rotate about the center of the valve shaft 8 as a rotation axis.

A motor 9 is attached to one end of the valve shaft 8. The motor 9 is driven and controlled by a command from an engine electronic control unit (ECU) 15. The opening degree of the throttle valve 3 is controlled by driving the motor 9, and the intake air amount supplied to the engine is adjusted.

A bottomed cylindrical holder 10 is provided at the other end of the valve shaft 8. On the inner wall of the holder 10 in the radial direction, there are two magnets 11, 12 constituting the magnetic field forming unit 5 and two yokes (not shown) that connect the two magnets 11, 12 in the circumferential direction. Is provided. The two magnets 11 and 12 are provided so as to face the rotation axis of the throttle valve 3 in the radial direction, and provide an N pole magnetic flux to one yoke and an S pole magnetic flux to the other yoke. As a result, a magnetic flux flows in the direction orthogonal to the rotation axis of the throttle valve 3 by forming a magnetic flux inside the holder 10 from one yoke to the other yoke. When the throttle valve 3 rotates, the direction of the magnetic field inside the holder 10 changes.

The housing cover 6 is attached to the magnetic field forming part 5 side of the housing 4 with screws 13 or the like.

The housing cover 6 is formed in a dish shape from resin. A wiring 14 is fixed to the housing cover 6.

The magnetic field detection device 1 is fixed to the housing cover 6, and a part of the magnetic field detection device 1 is inserted inside the holder 10. As shown in FIGS. 2 to 5, the magnetic field detection device 1 is configured by an IC package 20 and a terminal 30 being molded (covered) by a resin mold body 40.

The IC package 20 outputs a voltage signal corresponding to the direction of the magnetic field formed by the magnetic field forming unit 5. The terminal 30 electrically connects the IC package 20 and the wiring 14 of the housing cover 6 described above. The resin mold body 40 fixes the IC package 20 and a part of the terminal 30 with a resin mold, and suppresses positional fluctuation between the IC package 20 and the terminal 30.

The signal output from the IC package 20 is transmitted from the terminal 30 to the ECU 15 via the wiring 14 of the housing cover 6. The ECU 15 controls each part of the vehicle.

Subsequently, the IC package 20, the terminal 30, and the resin mold body 40 constituting the magnetic field detection device 1 of the first embodiment will be described in detail with reference to FIGS.

The IC package 20 is obtained by molding a magnetic detection element 21 (see FIG. 5) and a lead frame 22 with a resin material 23.

The magnetic detection element 21 is a semiconductor integrated circuit, in which a first magnetic detection unit and a second magnetic detection unit are formed. The first magnetic detection unit and the second magnetic detection unit are not shown because they are formed in part of the semiconductor integrated circuit. The first magnetic detection unit outputs a voltage signal corresponding to the magnetic flux density that passes through its own magnetic detection surface. The second magnetic detection unit also outputs a voltage signal corresponding to the magnetic flux density that passes through its own magnetic detection surface. Here, in the semiconductor integrated circuit, the magnetic detection surface of the first magnetic detection unit and the magnetic detection surface of the second magnetic detection unit are formed to be orthogonal to each other. Therefore, as shown in FIG. 6, the first magnetic detection unit and the second magnetic detection unit output sin waveform and cos waveform signals whose phases are shifted from each other by 90 ° with respect to a predetermined magnetic field direction.

Note that the horizontal axis of FIG. 6 represents the rotation angle, and the vertical axis represents the signal output when the amplitude of the sin wave and the cos wave is 1. In FIG. 6, the output signal of the first magnetic detection unit is indicated by a solid line M, and the output signal of the second magnetic detection unit is indicated by a broken line N.

For example, the calculation unit in the IC package 20 performs arctangent calculation using the signal output from the first magnetic detection unit as a sin wave signal and the signal output from the second magnetic detection unit as a cos wave signal, A linear signal corresponding to the rotation angle is output to the ECU 15. As a result, the magnetic field detection device 1 can accurately detect the rotation angle of the throttle valve 3. In other embodiments, the arc tangent calculation may be performed in the ECU 15.

3 and 5, the four lead frames 22 are all arranged so as to extend along the surface direction of the magnetic detection element 21. The four lead frames 22 and the magnetic detection element 21 are electrically connected by a bonding wire (not shown) inside the resin material 23.

The resin material 23 is formed by molding a part of the four lead frames 22, the magnetic detection element 21, and a bonding wire. The resin material 23 protects the magnetic detection element 21 and the like from impact, heat, moisture, and the like.

Each of the four lead frames 22 has one end protruding from the resin material 23. In the portion protruding from the resin material 23, the four lead frames 22 are bent substantially perpendicular to the surface direction of the magnetic detection element 21.

The terminal 30 is provided substantially perpendicular to the surface direction of the magnetic detection element 21. All of the four lead frames 22 described above are electrically and mechanically connected to the terminal 30 by welding or the like. In FIG. 5, the welded portion between the lead frame 22 and the terminal 30 is indicated by reference numeral 31.

Resin mold body 40 molds IC package 20 and terminal 30.

The resin mold body 40 integrally includes a base portion 41, a head portion 42, a detection side cutout portion 43, and a frame side cutout portion 44.

The base portion 41 is formed in a trapezoidal shape, and a portion including a connection portion between the lead frame 22 and the terminal 30 is molded. Specifically, the base portion 41 is formed by molding the resin material 23 on the portion closer to the terminal 30 than the magnetic detection element 21 of the IC package 20, the lead frame 22, and a part of the terminal 30. The foundation 41 protects the welded portion 31 between the lead frame 22 and the terminal 30 and the lead frame 22. The base portion 41 may be formed in a substantially trapezoidal cross section.

The head portion 42 protrudes from the base portion 41 toward the side opposite to the terminal 30 and molds a portion including the magnetic detection element 21 of the IC package 20. Specifically, the head portion 42 is formed to have a smaller cross-sectional area than the base portion 41 and is molded with the resin material 23 of the portion including the magnetic detection element 21 of the IC package 20. Due to the head portion 42, position fluctuations between the IC package 20 and the terminal 30 are suppressed.

Here, the outer wall surface of the thickest part at the base of the head 42 located on the magnetic detection element 21 side with respect to the lead frame 22 is referred to as a “detection side reference surface 48”. In addition, the outer wall surface of the thickest portion at the base of the head 42 positioned on the lead frame 22 side with respect to the magnetic detection element 21 is referred to as a “frame side reference surface 47”. Further, among the outer wall surfaces of the IC package 20 formed of the resin material 23, the outer wall surface of the IC package 20 positioned on the magnetic detection element 21 side with respect to the lead frame 22 is referred to as “element corresponding surface 24”. Further, the outer wall surface of the IC package 20 positioned on the lead frame 22 side with respect to the magnetic detection element 21 is referred to as a “frame corresponding surface 25”. The maximum thickness portion may be a portion of the head where the thickness from the IC package is maximum. The maximum thickness portion may be a portion of the head portion 42 having a maximum thickness in a direction perpendicular to the surface direction of the magnetic detection element 21.

The resin mold body 40 of the first embodiment has a detection-side notch 43 that is recessed from the detection-side reference surface 48 of the IC package 20 toward the element corresponding surface 24. In addition, the resin mold body 40 has a frame-side notch 44 that is recessed from the frame-side reference surface 47 of the IC package 20 toward the frame corresponding surface 25.

That is, the resin mold body 40 does not mold the element corresponding surface 24 and the frame corresponding surface 25 of the IC package 20. Therefore, both the element corresponding surface 24 and the frame corresponding surface 25 of the IC package 20 are exposed from the resin mold body 40.

With the above-described configuration, the magnetic field detection device 1 of the first embodiment has the following operational effects.

(1) In the first embodiment, the resin mold body 40 includes the detection-side cutout portion 43 and the frame-side cutout portion 44 so that the element corresponding surface 24 and the frame corresponding surface 25 of the IC package 20 are generated when the temperature changes. It is possible to reduce the stress caused by the difference in linear expansion. Therefore, it is possible to suppress an error from occurring in signals output from the first magnetic detection unit and the second magnetic detection unit formed in the magnetic detection element 21. As a result, the detection accuracy of the magnetic field detection device 1 can be increased.

In the first embodiment, when the resin mold body 40 is injection-molded, the inner wall of the mold into which the IC package 20 and the terminal 30 are inserted is brought into contact with the element corresponding surface 24 and the frame corresponding surface 25 of the IC package 20. In this state, the resin mold body 40 can be injection molded. Thereby, since the positioning accuracy of the IC package 20 is improved, the detection accuracy of the magnetic field detection device 1 can be increased.

(2) In the first embodiment, the resin mold body 40 does not mold the element corresponding surface 24 of the IC package 20. That is, the element corresponding surface 24 is exposed from the resin mold body 40. Further, the thickness of the maximum thickness portion of the head portion 42 including the detection side reference surface 48 is set to such an extent that the position variation between the terminal 30 and the IC package 20 can be suppressed.

Thereby, the magnetic field detection apparatus 1 can achieve both a configuration for reducing the stress caused by the linear expansion difference that occurs when the temperature changes and a configuration for suppressing the positional variation between the IC package 20 and the terminal 30. .

(3) In the first embodiment, the resin mold body 40 does not mold the frame corresponding surface 25 of the IC package 20. That is, the frame corresponding surface 25 is exposed from the resin mold body 40. Thereby, the magnetic field detection apparatus 1 can suppress the occurrence of an error in the signal output from the magnetic detection element 21 by adopting a configuration that reduces the stress caused by the difference in linear expansion that occurs when the temperature changes. .

Further, the resin mold body 40 can be injection-molded in a state where the inner wall of the mold for injection-molding the resin mold body 40 and the frame corresponding surface 25 of the IC package 20 are in contact with each other. Thereby, since the positioning accuracy of the IC package 20 is improved, the detection accuracy of the magnetic field detection device 1 can be increased.

(4) In the first embodiment, the magnetic detection element 21 has a first magnetic detection unit and a second magnetic detection unit that output signals whose phases are shifted from each other by 90 ° with respect to a predetermined magnetic field direction.

Accordingly, a linear signal can be obtained by performing an arctangent calculation using the signal output from the first magnetic detection unit as a sin wave signal and the signal output from the second magnetic detection unit as a cos wave signal. it can. As a result, the magnetic field detection device 1 can accurately detect the rotation angle of the throttle valve 3.

(Second Embodiment)
A second embodiment of the present disclosure is shown in FIGS. Also in the second embodiment, as in the first embodiment, the resin mold body 40 has the detection-side cutout portion 43 and the element corresponding surface 24 is exposed from the resin mold body 40. However, in the second embodiment, the frame corresponding surface 25 of the IC package 20 is covered with the frame-side thin portion 45 having a thickness T1. That is, the frame corresponding surface 25 is molded relatively thin. This thickness T1 is such a thickness that the stress by the frame-side thin portion 45 does not affect the output of the magnetic detection element 21.

As a result, the stress acting on the magnetic detection element 21 from the frame-side thin portion 45 of the resin mold body 40 through the frame corresponding surface 25 of the IC package 20 due to the difference in linear expansion at the time of temperature change is reduced. The accuracy of the output of the detection element 21 can be increased.

Further, the thickness from the frame-corresponding surface 25 of the IC package 20 to the frame-side reference surface 47 of the head 42 at a location outside the frame-side thin portion 45 is T2. At this time, T1 <T2. As described above, by increasing the thickness T2 of the head portion 42 up to the frame side reference surface 47, it is possible to suppress the positional variation between the terminal 30 and the IC package 20.

In the second embodiment, when the resin mold body 40 is injection-molded, the resin mold body 40 can be injection-molded in a state where the inner wall of the mold and the frame corresponding surface 25 of the IC package 20 are not in contact with each other. It is. Therefore, the magnetic field detection device 1 can relax the required accuracy of the mold.

(Third embodiment)
A third embodiment of the present disclosure is shown in FIGS. 9 and 10. In the third embodiment, the element corresponding surface 24 of the IC package 20 is covered with the detection-side thin portion 46 having a thickness T3. That is, the element corresponding surface 24 is molded relatively thin. This thickness T3 is such a thickness that the stress by the detection-side thin portion 46 does not affect the output of the magnetic detection element 21.

As a result, stress acting on the magnetic detection element 21 from the detection-side thin portion 46 of the resin mold body 40 via the element corresponding surface 24 of the IC package 20 due to a difference in linear expansion at the time of temperature change is reduced. The accuracy of 21 outputs can be increased.

Further, the thickness from the element corresponding surface 24 of the IC package 20 to the detection side reference surface 48 of the head 42 at a location outside the detection side thin portion 46 is T4. At this time, T3 <T4. As described above, by increasing the thickness T4 of the head 42 up to the detection side reference surface 48, it is possible to suppress the positional variation between the terminal 30 and the IC package 20.

In the third embodiment, when the resin mold body 40 is injection-molded, the inner wall of the mold and the element corresponding surface 24 of the IC package 20 do not come into contact with each other, and the inner wall of the mold and the frame of the IC package 20 are compatible. The resin mold body 40 can be injection-molded in a state where the surface 25 is not in contact. Therefore, the magnetic field detection device 1 can relax the required accuracy of the mold.

(Fourth embodiment)
A fourth embodiment of the present disclosure is shown in FIGS. 11 and 12. In the fourth embodiment, the outer wall surface of the head portion 42 of the resin mold body 40 that covers the frame corresponding surface 25 of the IC package 20 is a surface obtained by extending the frame-side reference surface 47. Therefore, the frame corresponding surface 25 is molded relatively thick like the maximum thickness portion at the base of the head 42 where the frame side reference surface 47 is defined.

On the other hand, also in the fourth embodiment, as in the third embodiment, the element corresponding surface 24 of the IC package 20 is covered with the detection-side thin portion 46 having a thickness T3. That is, the element corresponding surface 24 is molded relatively thin.

Also in the fourth embodiment, when the resin mold body 40 is injection-molded, the inner wall of the mold does not contact the element corresponding surface 24 of the IC package 20, and the inner wall of the mold and the frame of the IC package 20 The resin mold body 40 can be injection-molded in a state where the corresponding surface 25 is not in contact. Therefore, the magnetic field detection device 1 can relax the required accuracy of the mold.

In the above-described embodiment, the magnetic field detection device 1 that detects the rotation angle of the throttle valve 3 as the detection target has been described. However, the magnetic field detection device 1 may detect a rotation angle of an accelerator pedal or a crankshaft, for example.

As described above, the present disclosure is not limited to the above-described embodiment, and can be implemented in various forms without departing from the spirit of the disclosure in addition to combining the above-described plurality of embodiments.

Although the present disclosure has been described with reference to the embodiments, it is understood that the present disclosure is not limited to the embodiments and structures. The present disclosure includes various modifications and modifications within the equivalent range. In addition, various combinations and forms, as well as other combinations and forms including only one element, more or less, are within the scope and spirit of the present disclosure.

Claims

A magnetic detection element (21) for outputting a signal corresponding to the direction of the magnetic field; a lead frame (22) located on the first side of the magnetic detection element; connected to the magnetic detection element; and the magnetic detection element An IC package (20) having (21) and a resin material (23) covering the lead frame (22);
A terminal (30) connected to a portion protruding from the resin material of the lead frame of the IC package;
A base portion (41) covering a portion including a connection portion between the lead frame and the terminal, and a portion protruding from the base portion toward the opposite side of the terminal and including the magnetic detection element of the IC package A resin mold body (40) that covers the IC package and a part of the terminal;
With
The head has a maximum thickness portion where the thickness from the surface of the IC package is maximum among the head.
An outer wall surface of the maximum thickness portion located on the second side of the magnetic detection element opposite to the first side is defined as a detection side reference surface (48),
The element corresponding surface (24) which is the outer wall surface of the IC package located on the second side is exposed from the resin mold body, or, among the resin mold bodies, from the element corresponding surface to the detection side The magnetic field detection apparatus covered with the detection side thin part (46) which has thickness (T3) thinner than the thickness (T4) to a reference plane.
The magnetic field detection device according to claim 1, wherein the element corresponding surface is exposed from the resin mold body.
The magnetic field detection device according to claim 1 or 2, wherein a frame corresponding surface (25) which is an outer wall surface of the IC package located on the first side is exposed from the resin mold body.
When the outer wall surface of the maximum thickness portion of the head located on the first side is a frame side reference surface (47),
The frame corresponding surface (25) which is the outer wall surface of the IC package located on the first side is thinner than the thickness (T2) from the frame corresponding surface to the frame side reference surface in the resin mold body. The magnetic field detection device according to claim 1 or 2, wherein the magnetic field detection device is covered with a frame-side thin portion (45) having a thickness (T1).
5. The magnetic detection element according to claim 1, wherein the magnetic detection element includes a first magnetic detection unit and a second magnetic detection unit that output signals whose phases are shifted from each other by 90 ° with respect to a predetermined magnetic field direction. Magnetic field detection device.