JP2001289865A - Number-of-revolution sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a number-of-revolution sensor in which the electrical connection between connector terminals and an element section does not become unstable even when strong vertical vibrations are applied to the sensor and which has a stable output characteristic. SOLUTION: This number-of-revolution sensor is constituted in such a way that a connection terminal 29 is passed through first, second, and third through holes 19, 23, and 26 respectively made through a circuit board 17, a pedestal 21, and a substrate 25 and, at the same time, both ends of the terminal 29 are respectively connected electrically to the circuit board 17 and a connector terminal 28 on the substrate 25.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotation speed sensor for detecting a rotation speed by a change in magnetism.

[0002]

2. Description of the Related Art A conventional rotational speed sensor will be described below with reference to the drawings.

[0003] As a conventional rotation speed sensor of this type, one disclosed in Japanese Patent Application Laid-Open No. Hei 6-186240 is known.

FIG. 8 is a side sectional view of a conventional rotation speed sensor.

In FIG. 8, reference numeral 1 denotes a semiconductor substrate, and the semiconductor substrate 1 has a magnetoresistive element (not shown) on its surface. Reference numeral 2 denotes a resin element part, which is formed such that the semiconductor substrate 1 is integrally formed therein and the lead frame 3 projects upward. Reference numeral 4 denotes a magnet, which is provided with a through-hole 5 penetrating from the upper part to the lower part substantially at the center of the magnet 4, and the element part 2 is inserted into the through-hole 5. Reference numeral 6 denotes a base made of resin. The base 6 has a storage portion 7 provided inside, and the storage portion 7 has a lead frame 3 in the element portion 2.
Is stored. A connector portion 8 is provided on the upper portion of the base 6, and 3
The connector terminal 9 is provided integrally, and the connector terminal 9 has one end protruding upward and the other end positioned in the storage section 7.
Thus, the connector terminal 9 is electrically connected to the lead frame 3 in the element section 2 by means such as soldering or welding. And the connector terminal 9
Is provided with a bent portion 9a substantially at the center. Reference numeral 10 denotes a cover made of a metal such as alumina.
The cover 4 is fixed to the base 6 by covering the magnet 4 and the element section 2 so as to be housed therein, and by caulking the upper end of the cover 10 with the outer surface of the base 6. The bent portion 9 of the connector terminal 9
By urging the element portion 2 downward by a, the lower surface of the element portion 2 is brought into contact with the inner bottom surface of the cover portion 10.

Next, the operation of the conventional rotation speed sensor having the above-described structure will be described.

The rotation of the concavities and convexities in the gear (not shown) of the other vehicle provided below the cover 10 causes the magnet 4 to rotate.
The magnetic flux density with respect to the magnetoresistive element (not shown) of the semiconductor substrate 1 in the element portion 2 provided at the through hole 5 changes. Then, a change in the magnetic flux density of the magnetoresistive element (not shown) is output to the other computer (not shown) via the lead frame 3 and the connector terminal 9 to detect the rotation speed.

[0008]

However, in the above-described conventional configuration, a bent portion 9a is provided substantially at the center of the connector terminal 9, and the element portion 2 is urged downward by the bent portion 9a. The lower part of the element part 2 is covered.
0, the element portion 2 vibrates up and down against this urging force when strong vibration is applied to the rotation speed sensor in the vertical direction. Since stress is applied to the connection between the lead frame 3 and the connector terminal 9, there is a problem that the electrical connection between the connector terminal 9 and the lead frame 3 becomes unstable.

The present invention solves the above-mentioned conventional problems. Even if strong vibration is applied to the rotational speed sensor in the vertical direction, the electrical connection between the connector terminal and the element portion becomes unstable. However, an object of the present invention is to provide a rotation speed sensor having stable output characteristics.

[0010]

In order to achieve the above object, a rotation speed sensor according to the present invention comprises a semiconductor substrate provided with a magnetoresistive element on one surface; An element part having a lead frame electrically connected to the element, a circuit part for installing the element part, converting an output signal of the magnetoresistive element into a pulse signal, and providing a first through hole; And a circuit board holding the circuit board, fixing the other end of the magnet such that one end of the magnet is disposed near the magnetoresistive element, and has a second through hole. A base having the provided base, a base having a connector part mounted with the base, having a third through hole, and further having a connector terminal protruding outward, the element part, and a circuit board; Covers, magnets and base And a cover portion attached to the base. The connection terminal is inserted through the first through-hole in the circuit board, the second through-hole in the base, and the third through-hole in the base. Is electrically connected to the circuit board, and the other end is electrically connected to the connector terminal on the base. According to this configuration, the rotational speed sensor has strong vibration in the vertical direction. Even if is added, the electrical connection state between the connector terminal and the element section does not become unstable, and a rotation speed sensor with stable output characteristics can be provided.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS According to the first aspect of the present invention, there is provided a semiconductor substrate provided with a magnetoresistive element on one surface, and the semiconductor substrate is provided and electrically connected to the magnetoresistive element. An element portion having a lead frame to be provided, a circuit board provided with the element portion, a circuit component for converting an output signal of the magnetoresistive element into a pulse signal, and a first through hole provided; A base holding the circuit board, fixing the other end of the magnet so that one end of the magnet is disposed near the magnetoresistive element, and having a second through hole; Attaching this base,
A base having a connector portion provided with a third through hole and further provided with connector terminals protruding outward;
A cover portion attached to the base so as to cover the element portion, the circuit board, the magnet, and the base; and a first through hole in the circuit board, a second through hole in the base, and a third through hole in the base. A connection terminal is inserted through the through hole, one end of the connection terminal is electrically connected to the circuit board, and the other end is electrically connected to the connector terminal of the base. According to the configuration, the circuit board is held on the base, and the connection terminal is inserted into the first through hole in the circuit board, the second through hole in the base, and the third through hole in the base, and the connection is performed. Since one end of the terminal is electrically connected to the circuit board, and the other end of the connection terminal is electrically connected to the connector terminal of the base,
Even if a strong vertical vibration is applied to the rotation speed sensor, the circuit board does not move due to the strong vertical vibration, and thus, the connection terminal and the connector terminal, and the connection terminal and the connection terminal and the circuit board are soldered. Since the electrical connection state does not become unstable, the output characteristic has an effect of always obtaining a stable output characteristic.

According to a second aspect of the present invention, the third through hole of the base according to the first aspect is filled with a fixing member and the connection terminal is fixed by the fixing member. Since the third through hole in the base is filled with a fixing member and the connection terminal is fixed by the fixing member,
The connection terminal located in the third through hole is reinforced by the fixing member, and thereby the connection terminal is difficult to move in the third through hole. This has an effect that stress due to vibration is less likely to be applied to the connection portion of the connection terminal.

According to a third aspect of the present invention, the connection terminal according to the first aspect is formed of a copper wire. According to this configuration, since the connection terminal is formed of a copper wire, a rotation speed sensor is provided. Even if the ambient temperature of the surroundings changes and the connection terminals and the base are displaced by their respective coefficients of thermal expansion, the connection terminals made of copper wire are easily deformed, thereby connecting the connection terminals and the connector terminals. Since stress is less likely to be applied to the connection portion and the connection portion between the connection terminal and the circuit board, the output characteristic of the rotation speed sensor has an effect of always obtaining stable output characteristics.

According to a fourth aspect of the present invention, the connector terminal of the base according to the first aspect is provided with a hole, and the other end of the connection terminal is inserted into the hole to connect the connector terminal and the other end of the connection terminal. Is electrically connected by fixing
According to this configuration, the connector terminal in the base is provided with a hole, the other end of the connection terminal is inserted into the hole, and the connector terminal and the other end of the connection terminal are fixed to each other to be electrically connected. Therefore, even when lateral vibration is applied to the rotation speed sensor, the outer periphery of the connection terminal can be supported by the inner side surface of the hole in the connector terminal, thereby providing an electrical connection between the connector terminal and the connection terminal. Also has the effect that a stable product can be obtained.

According to a fifth aspect of the present invention, a circuit board is fixed to the base of the first aspect with a gel-like adhesive.
According to this configuration, since the circuit board is fixed to the base with a gel-like adhesive, the circuit board is separated from the base by the differences in the thermal expansion coefficients of the base, the magnet, the circuit board, and the element portion. Even if the gel adhesive is released due to a change in the ambient temperature, the gel adhesive can freely expand and contract, thereby having an effect that the circuit board can be securely bonded to the base.

According to a sixth aspect of the present invention, there is provided a circuit board according to the first aspect, wherein a hole is provided substantially in the center and a concave portion is provided in the terminal portion, and a magnet is provided in the concave portion of the element portion through the hole in the circuit board. With one end attached, according to this configuration, a hole is provided substantially in the center of the circuit board and a concave portion is provided in the element portion,
Since one end of the magnet is attached to the concave portion of the element portion through the hole of the circuit board, the positioning of the magnetoresistive element and the magnet in the element portion can be accurately performed by the concave portion of the element portion. Accordingly, the output characteristics of the rotation speed sensor can be stabilized.

Hereinafter, a rotation speed sensor according to an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a side sectional view of a rotation speed sensor according to an embodiment of the present invention, FIG. 2 is a side sectional view of an element portion in the rotation speed sensor, and FIG. 3 is a top view of a circuit board in the rotation speed sensor. FIG. 4 is a top view of a base in the rotation speed sensor, FIG. 5 is a bottom view of a base in the rotation speed sensor, and FIG.
FIG. 7 is a side view of a connector terminal in the rotation speed sensor, and FIG.
FIG. 4 is a side sectional view showing a state in which connection terminals are inserted into a base in the rotation speed sensor.

In FIG. 1 to FIG. 7, reference numeral 11 denotes a pair of magnetoresistive elements made of InSb.
1 is provided on the lower surface of a pair of semiconductor substrates 12 made of Si as shown in FIG. Numeral 13 denotes a resin element portion, which has a lead frame 14 embedded therein, and a lower surface of the lead frame 14 shown in FIG.
While installing the semiconductor substrate 12 as shown in FIG.
The lead frame 14 and the magnetoresistive element 11 are electrically connected by a wire 15 made of gold.
A concave portion 16 is provided on the upper surface of the element portion 13.
Reference numeral 17 denotes a circuit board. The circuit board 17 has the element portion 13 provided on the lower surface thereof, and a hole 18 is provided from a substantially central upper surface to a lower surface of the circuit board 17.
As shown in FIG. 7, three first through holes 19 are provided from the upper surface to the lower surface of the circuit board 17 at positions different from the positions where the holes 18 are provided. A circuit component 20 is provided on the upper surface of the circuit board 17, and the circuit component 20 converts an output signal of the magnetoresistive element 11 into a pulse signal. Reference numeral 21 denotes a resin base. The circuit board 17 is fixed to the inside of the base 21 with a gel-like adhesive 22. The circuit base 17 extends from the upper surface to the lower surface of the base 21 as shown in FIG. First through hole 1 in substrate 17
Three second through-holes 23 are provided at positions slightly away from a position continuous with 9. Reference numeral 24 denotes a magnet. The magnet 24 has a lower end portion inserted into the hole 18 in the circuit board 17 and is fixed to the concave portion 16 in the element portion 13. are doing.

As described above, in one embodiment of the present invention, the hole 18 is provided substantially at the center of the circuit board 17 and the concave portion 16 is provided in the element portion 13. Since the lower end of the magnet 24 is mounted in the concave portion 16 of the element 13, the positioning of the magnetoresistive element 11 and the magnet 24 in the element portion 13
And the output characteristics of the rotation speed sensor can be stabilized.

Reference numeral 25 denotes a resin base. The base 25 fixes the base 21 to the lower surface, and as shown in FIG.
Three third through holes 26 are provided from the upper surface to the lower surface, and the third through holes 26 are connected to the second through holes 23 in the base 21. The base 2
5, a connector 27 is integrally formed, and a connector terminal 28 as shown in FIG. 6 is integrally embedded inside the connector 27, and the connector terminal 28 has an upper portion directed upward. It protrudes toward. A hole 28a is provided below the connector terminal 28. Further, the base 25 is provided with a groove 25a over the entire outer surface. 29 is a connection terminal made of copper wire,
The connection terminal 29 is inserted into the inside of the third through-hole 26 in the base 25, and a gel-like adhesive is provided between the connection terminal 29 and the third through-hole 26 as shown in FIG. Is provided. As described above, the third through hole 26 in the base 25 is filled with the fixing member 30 made of a gel-like adhesive, and the connection terminal 29 is fixed by the fixing member 30 so that the third through hole 26 is located in the third through hole 26. Since the connection terminal 29 is reinforced by the fixing member 30, the connection terminal 29 does not easily move in the third through hole 26, thereby connecting the connection terminal 29 to the connection portion between the connector terminal 28 and the circuit board 17. Terminal 2
Since it becomes difficult for stress due to vibration to be applied to the connection portion of No. 9,
This has the effect of providing a rotation speed sensor with improved strength against vibration.

An upper end of the connection terminal 29 is provided with a hole 28 provided below the connector terminal 28 in the base 25.
a, and by soldering the periphery of the hole 28a, the upper end of the connection terminal 29 and the lower part of the connector terminal 28 are electrically connected. The lower portion of the connection terminal 29 is inserted into the second through hole 23 of the base 21 and the first through hole 19 of the circuit board 17, and the lower end is soldered to the circuit board 17. Reference numeral 31 denotes a metal cover made of, for example, aluminum or the like.
7, provided so as to cover the magnet 24 and the base 21;
The cover 31 is fixed to the base 25 by caulking the upper end of the cover 31 to the side surface of the base 25. The cover 31 and the groove 2 provided in the base 25 are formed.
An O-ring 32 is provided between the cover 5 and the base 5 to prevent dust from passing through the space between the cover portion 31 and the base 25 from the outside. 33
Is a sealing body made of epoxy resin, and this sealing body 33 seals the vicinity of the connection between the connector terminal 28 and the connection terminal 29.

Next, a method of assembling the rotational speed sensor according to the embodiment of the present invention will be described.

First, In is formed on the lower surfaces of the pair of semiconductor substrates 12.
A pair of magnetoresistive elements 11 made of Sb are formed by vapor deposition.

Next, after the upper surface of the semiconductor substrate 12 is fixed to the lead frame 14 with an adhesive such as a die bond,
The magnetoresistive element 11 and the lead frame 14 are electrically connected by a wire 15 made of gold.

Next, after the lead frame 14, the semiconductor substrate 12, and the magnetoresistive element 11 are set in a mold, the element portion 13 is formed by filling the resin.

Next, after mounting the element portion 13 on the lower surface of the circuit board 17, the circuit component 20 is mounted on the upper surface of the circuit board 17.
Implement

Next, the connection terminal 29 is inserted into the second through hole 23 in the base 21 from below.

Next, the lower end of the magnet 24 is
Is fixed to the concave portion 16 by an adhesive.

Next, the lower portion of the connection terminal 29 is inserted into the first through hole 19 of the circuit board 17, and the upper end of the magnet 24 is fixed to the inner top surface of the base 21 with an adhesive. The outer peripheral portion of the substrate 17 is fixed to the base 21 with a gel adhesive 22. In this way, the base 2
If the circuit board 17 is fixed to the base 1 with a gel-like adhesive 22, the circuit board 17 is separated from the base 21 due to the difference in the thermal expansion coefficients of the base 21, the magnet 24, the circuit board 17, and the element portion 13. Even if the gel-like adhesive 22 is free to expand and contract even if the ambient temperature changes, the gel-type adhesive 22 has an effect that the circuit board 17 can be securely bonded to the base 21.

Next, after a fixing member 30 made of a gel-like adhesive is applied to the outer surface of the connection terminal 29, the connection terminal 29 is connected to the third through hole 26 in the base 25 and the hole 28a in the connector terminal 28. Insert

Next, the hole 2 in the connector terminal 28 will be described.
After the inner peripheral portion 8a and the connection terminal 29 are electrically connected by soldering, the vicinity where the connection terminal 29 and the connector terminal 28 are connected is sealed with a sealing body 33 made of epoxy resin.

Next, after the O-ring 32 is mounted in the groove 25a of the base 25, the cover 31 is put on the base 25 so as to house the base 21, the magnet 24 and the element 13 inside.

Finally, the upper end of the cover portion 31 is
5 by crimping on the side surface of the base 2
5 is fixed.

Next, the operation of the rotation speed sensor according to the embodiment of the present invention configured as described above will be described.

A gear (not shown) of the other vehicle is provided on the side opposite to the lower part of the cover portion 31. The rotation of the gear (not shown) causes the magnetic resistance element 11 to rotate. The magnetic flux density changes. The change in the magnetic flux density is output by the magnetoresistive element 11 as a sine waveform output voltage, and the sine waveform output voltage is converted into a pulse signal output voltage by the circuit component 20 on the circuit board 17. The output voltage of the pulse signal is output to the other computer (not shown) via the connection terminal 29 and the connector terminal 28 to detect the rotation speed.

Considering the case where a strong vertical vibration is applied to the rotation speed sensor, in the rotation speed sensor according to the embodiment of the present invention, the circuit board 17 is held on the base 21 and The first through hole 19 in the circuit board 17 and the second through hole 2 in the base 21
The connection terminal 29 is inserted into the third through hole 26 of the base 3 and the base 25, and the lower end of the connection terminal 29 is electrically connected to the circuit board 17, and the upper end of the connection terminal 29 is connected to the base 25. Is electrically connected to the connector terminal 28, even if a strong vertical vibration is applied to the rotation speed sensor, the circuit board 17 does not move due to the strong vertical vibration. Since the electrical connection state due to the soldering of the connection terminals 29 and the connector terminals 28 and the connection terminals 29 and the circuit board 17 does not become unstable, the output characteristics are always stable. Things.

Considering the case where the ambient temperature around the rotation speed sensor changes, in the rotation speed sensor according to the embodiment of the present invention, since the connection terminal 29 is made of a copper wire, Even if the ambient temperature around the rotation speed sensor changes and the connection terminal 29 and the base 25 are displaced by their respective thermal expansion coefficients, the connection terminal 29 made of a copper wire is easily deformed. Connection between terminal 29 and connector terminal 28 and connection terminal 29
The stress is less likely to be applied to the connection between the motor and the circuit board 17, so that the output characteristics of the rotation speed sensor are always stable, and as a result, the strength of the connection is improved even when the ambient temperature changes. This has an effect that a large number of rotation speed sensors can be provided.

Considering the case where lateral vibration is applied to the rotation speed sensor, in the rotation speed sensor according to the embodiment of the present invention, a hole 28a is provided in the connector terminal 28 of the base 25, This hole 28a
The upper end of the connection terminal 29 is inserted through the
And the upper end of the connection terminal 29 are electrically connected to each other, so that even if lateral rotation is applied to the rotation speed sensor, the outer periphery of the connection terminal 29 is connected to the connector terminal 2.
8 can be supported by the inner side surface of the hole 28a, thereby providing an effect that a stable electrical connection between the connector terminal 28 and the connection terminal 29 can be obtained.

[0040]

As described above, the rotation speed sensor of the present invention is
A semiconductor substrate provided with a magnetoresistive element on one surface, and an element section having this semiconductor substrate, and a lead frame electrically connected to the magnetoresistive element; and installing the element section, A circuit board for converting an output signal of the magnetoresistive element into a pulse signal; and a circuit board provided with a first through-hole; and a circuit board holding the circuit board and a magnet positioned near the magnetoresistive element. A base having the other end of the magnet fixed thereto such that one end thereof is provided, and having a second through-hole; mounting the base and providing a third through-hole; A base having a connector portion provided so as to protrude outward, and a cover portion attached to the base so as to cover the element portion, the circuit board, a magnet and a base. First through hole A connection terminal is inserted into the second through hole in the base and the third through hole in the base, one end of the connection terminal is electrically connected to the circuit board, and the other end is a connector terminal in the base. Even if strong vibration is applied to the rotation speed sensor in the vertical direction, the circuit board does not move due to strong vertical vibration, and thus the connection terminal and the connector terminal are connected. In addition, since the electrical connection state due to the soldering between the connection terminal and the circuit board does not become unstable, there is an effect that a stable output characteristic is always obtained.

[Brief description of the drawings]

FIG. 1 is a side sectional view of a rotation speed sensor according to an embodiment of the present invention.

FIG. 2 is a side sectional view of an element portion in the rotation speed sensor.

FIG. 3 is a top view of a circuit board in the rotation speed sensor.

FIG. 4 is a top view of a base in the rotation speed sensor.

FIG. 5 is a bottom view of a base in the rotation speed sensor.

FIG. 6 is a side view of a connector terminal in the rotation speed sensor.

FIG. 7 is a side cross-sectional view showing a state where the connection terminal is inserted into the base in the rotation speed sensor.

FIG. 8 is a side sectional view of a conventional rotation speed sensor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Magnetoresistive element 12 Semiconductor substrate 13 Element part 14 Lead frame 16 Recess 17 Circuit board 19 First through hole 20 Circuit component 21 Base 22 Adhesive 23 Second through hole 24 Magnet 25 Base 26 Third through hole 27 Connector part 28 Connector terminal 28a Hole 29 Connection terminal 30 Fixing member 31 Cover part

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) H01L 43/08 H01L 43/08 U (72) Inventor Kazuyuki Tsujioka 1006 Kazuma Kadoma, Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd. (72) Inventor Mikio Okamoto 1006 Kadoma, Kadoma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. (72) Inventor Kohei Harazono 1006 Odaka, Kazuma, Kadoma, Osaka Pref. AA50 BD16 CA40 DA01 DB07 DD02 EA03 GA52 GA61 GA69 GA79 GA80 KA01 KA05 LA19 ZA01 2F077 CC02 NN02 NN21 PP14 VV02 VV10 VV31 VV33 WW06

Claims (6)

[Claims] 1. A semiconductor substrate having a magnetoresistive element provided on one surface, an element section having a lead frame on which the semiconductor substrate is installed and electrically connected to the magnetoresistive element, A circuit board for providing an output signal of the magnetoresistive element into a pulse signal, and a first through-hole provided; and a circuit board holding the circuit board and near the magnetoresistive element. Position the other end of the magnet so that one end of the magnet is disposed,
A base provided with a second through-hole, a base mounted with the base, provided with a third through-hole, and further provided with a connector portion provided with connector terminals protruding outward; A cover portion attached to the base so as to cover the element portion, the circuit board, the magnet and the base, wherein a first through-hole in the circuit board, a second through-hole in the base and a second through-hole in the base. A rotation speed sensor having a configuration in which a connection terminal is inserted into the through hole of the third connection terminal, one end of the connection terminal is electrically connected to the circuit board, and the other end is electrically connected to a connector terminal of the base. . 2. The rotation speed sensor according to claim 1, wherein a fixing member is filled in the third through hole in the base, and the connection terminal is fixed by the fixing member. 3. The rotation speed sensor according to claim 1, wherein the connection terminal is formed of a copper wire. 4. A hole is provided in a connector terminal of a base,
The rotation speed sensor according to claim 1, wherein the other end of the connection terminal is inserted into the hole, and the connector terminal and the other end of the connection terminal are fixedly connected to each other to be electrically connected. 5. The rotation speed sensor according to claim 1, wherein the circuit board is fixed to the base with a gel adhesive. 6. The rotation speed sensor according to claim 1, wherein a hole is provided in substantially the center of the circuit board, a recess is provided in the element section, and one end of a magnet is mounted in the recess of the element section via the hole in the circuit board. .