JP2001023126A - Magnetic sensor and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the change in temperature dependent characteristic by covering side faces of two magnetoresistance element chips respectively electrically connected to a power supply electrode and a passive electrode in insertion parts of the two magnetoresistive element chips with a resin mold. SOLUTION: A first magnetoresistance element chip 11 and a second magnetoresistance element chip 12 are set to a chip set part of a substrate 1. An output wiring 24 is electrically connected to a first magnetic magnetoresistance element chip bump electrode 41 of the first magnetoresistance element chip 11, and a power source wiring 23 is electrically connected to a second chip bump electrode 42 of the chip. Then, a ground wiring 25 is electrically connected to a third magnetic magnetoresistance element chip bump electrode 43 of the second magnetoresistance element chip 12, and the output wiring 24 is electrically connected to the other chip bump electrode 44 of the chip. Finally, a resin is injected and molded into a resin insert hold part from side faces of the two magnetoresistance element chips 11 and 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic sensor element using a semiconductor magnetoresistive film used for detecting a linear movement or a rotational movement, and a method for manufacturing the same.

[0002]

2. Description of the Related Art A conventional magnetic sensor is disclosed in JP-A-8-201.
No. 016 is known.

In this conventional magnetic sensor, as shown in FIG. 9, a first and second semiconductor magnetoresistive element chips 2 and 2 are formed on a substrate 1 on which an element pitch pattern determined according to a magnetic flux density change shape to be combined is formed. 3 was mounted and electrically connected to the wiring on the upper surface of the substrate 1.

The magnetic sensor constructed as described above comprises an upper surface and side surfaces of the first and second semiconductor magnetoresistive element chips 2 and 3 and the first and second semiconductor magnetoresistive element chips 2 and 3. The vicinity of the upper surface of the mounted substrate 1 is resin-molded to maintain the durability of the first and second semiconductor magnetoresistive element chips 2 and 3 and various wirings on the upper surface of the substrate 1.

[0005]

However, in the above conventional configuration, the upper surfaces of the first and second semiconductor magnetoresistive element chips 2 and 3 are resin-molded, and the thickness of the resin mold is determined by the surface tension. However, there is a problem that the temperature-dependent characteristics fluctuate due to the variation in the thickness of the film.

An object of the present invention is to solve the above-mentioned conventional problems, and an object of the present invention is to provide a magnetic sensor having a small variation in temperature-dependent characteristics and a method of manufacturing the same.

[0007]

In order to achieve the above object, the present invention is provided so as to electrically connect a power supply electrode and a power reception electrode in first and second magnetoresistive element chip insertion portions, respectively. It comprises first and second magnetoresistive element chips, and a resin mold that covers at least side surfaces of the first and second magnetoresistive element chips.

Thus, the output temperature dependency between the magnetic sensor elements can be stabilized.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS According to the first aspect of the present invention, there are provided first and second magnetoresistive element chip insertion portions each having a power supply electrode and a power reception electrode therein, and the first and second magnetoresistive element chip insertion portions. A power supply line is electrically connected to a power supply electrode, and a ground line is electrically connected to a power receiving electrode in the second magnetoresistive element chip insertion portion, and power is received in the first magnetoresistive element chip insertion portion. A substrate provided with an output wiring so as to be electrically connected between the electrode and a power supply electrode in the second magnetoresistive element chip insertion portion; and a first and second magnetoresistive element chip insertion portion of the substrate. First and second magnetoresistive element chips provided so as to be electrically connected to the power supply electrode and the power receiving electrode, respectively, and provided so as to cover at least side surfaces of the first and second magnetoresistive element chips. Resin mold It is possible to maintain a durable connection part without forming a resin on the surface of a magnetoresistive element chip with a piezo effect, and to stabilize the output temperature dependency between elements of a differential type magnetic sensor element. It has an action.

[0010] The invention described in claim 2 is the same as the claim 1.
The substrate described above is made of either a lead comb or a flexible film having various wirings, and has an effect of achieving high heat resistance and low mounting.

[0011] The invention according to claim 3 is based on claim 1.
The substrate described above has a resin insertion holding portion near the first and second magnetoresistive element chip insertion portions, and resin molding is performed on the resin insertion holding portion and side surfaces of the first and second magnetoresistive element chips. By providing the resin insertion holding portion, the resin application region can be limited and the resin mold can be formed with rough application accuracy.

According to a fourth aspect of the present invention, there is provided a first and a second magnetoresistive element chip insertion portion having a power supply electrode and a power reception electrode therein, respectively, and a power supply electrode in the first magnetoresistive element chip insertion portion. And a ground wiring to electrically connect the power supply wiring to the power receiving electrode in the second magnetoresistive element chip insertion portion so as to be electrically connected to the power receiving electrode in the first magnetoresistive element chip insertion portion. An output wiring so as to be electrically connected to a power supply electrode in the second magnetoresistive element chip insertion section; and a resin insertion holding section near the first and second magnetoresistive element chip insertion sections. The resin insertion / holding portion of the substrate provided with is bent downward, and the power supply electrode and the power receiving electrode in the first and second magnetoresistive element chip insertion portions of the substrate obtained by bending the resin insertion / holding portion are electrically connected respectively. Connecting The first and second magnetoresistive element chips are formed as described above, and then the resin is injected and molded from at least the side surfaces of the first and second magnetoresistive element chips to the inside of the resin insertion holding section. The formation of the mold resin has an effect that the coating can be performed from the surface side of the magnetoresistive element chip without turning over the magnetoresistive element chip.

According to a fifth aspect of the present invention, there is provided a first and a second magnetoresistive element chip insertion portion having a power supply electrode and a power reception electrode therein, respectively, and a power supply electrode in the first magnetoresistive element chip insertion portion. And a ground wiring to electrically connect the power supply wiring to the power receiving electrode in the second magnetoresistive element chip insertion portion so as to be electrically connected to the power receiving electrode in the first magnetoresistive element chip insertion portion. An output wiring so as to be electrically connected to a power supply electrode in the second magnetoresistive element chip insertion section; and a resin insertion holding section near the first and second magnetoresistive element chip insertion sections. The power supply wiring and the power receiving wiring in the first and second magnetoresistive element chip insertion portions of the substrate having the above structure are bent upward, and the power supply wiring and the power receiving wiring in the magnetoresistive element chip insertion portion are bent. First and second magnetoresistive element chips are formed so as to be electrically connected to the power supply electrode and the power receiving electrode in the first and second magnetoresistive element chip insertion portions, respectively, and thereafter at least the first and second magnetic fields are formed. A resin is injected and molded from the side surface of the resistance element chip to the inside of the resin insertion holding portion, and the molding resin can be formed by applying from both sides of the magnetoresistive element chip and inserting the magnetoresistive element chip. Since the external power supply wiring and the power reception wiring can be formed lower than the surface of the magnetoresistive element chip, the surface of the resin mold can be formed lower.

According to a sixth aspect of the present invention, the step of bending the power supply wiring and the power receiving wiring in the resin insertion holding portion or the magnetoresistive element chip insertion portion of the substrate includes the steps of: This is a step of bending the resin within the range, and has an effect of preventing the mold resin from wrapping around the back surface of the magnetoresistive element chip.

An embodiment of the present invention will be described below with reference to FIGS.

Hereinafter, the magnetic sensor according to the first embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a plan view of a magnetic sensor according to an embodiment of the present invention, FIG. 2 is a cross-sectional view thereof, FIG. 3 is a schematic view thereof, FIG. It is sectional drawing of the board | substrate which is the principal part.

In FIG. 1, reference numeral 1 denotes a substrate, which is made of a flexible film such as a film carrier or a polyimide such as EPC. The substrate 1 has first and second magnetoresistive element chip mounting portions 21 and 22 for mounting first and second magnetoresistive element chips 11 and 12 to be described later. Magnetic resistance element chip mounting part 2
1st and 2nd magnetoresistive element chips 1 in the vicinity of 1 and 22
There is provided a resin insertion holding portion 13 in which the substrate 1 is bent to the lower surface side within the thickness of 1, 1. Further, the substrate 1 is provided with various wiring patterns including a power supply wiring 23, an output wiring 24, and a ground wiring 25 according to the shapes of the first and second magnetoresistive element chips 11, 12. The power supply wiring 23, the output wiring 24, and the ground wiring 25 are provided on the substrate 1 with first and second magnetoresistive element chips 11, which will be described later.
It is preferable to provide it on the same side as the side on which 12 is mounted. The power supply wiring 23 is electrically connected to one electrode of the first magnetoresistive element chip by a power supply wiring extension 26 extending from the power supply wiring 23. The output wiring 24 is connected to the other electrode of the first magnetoresistive element chip 11 by the first output wiring extension 27 extending from the output wiring 24 and to the second electrode by the second output wiring extension 28. It is electrically connected to one electrode of the magnetoresistive element chip 12. The ground wiring 25 is electrically connected to the other electrode of the second magnetoresistive element chip 12 by a ground wiring extension 29 extending from the ground wiring 25. At least side surfaces of the first and second magnetoresistive element chips 11 and 12 are covered with a resin mold 30. The first magnetoresistive element chip 11 and the second magnetoresistive element chip 12 have the configuration shown in FIGS. 6 and 7 described later.

FIG. 6 is a perspective view of a magnetoresistive element chip as a main part of the magnetoresistive element according to Embodiment 1 of the present invention, and FIG. 7 is a sectional view of the same.

In FIG. 1, reference numeral 31 denotes a magnetoresistive element substrate made of Si or the like. On the upper surface of the magnetoresistive element substrate 31, there is provided a magnetoresistive film 32 that is folded at least in either the longitudinal direction or the width direction of the magnetoresistive element substrate 31. The upper surface of the magnetoresistive film 32 has a short-circuit electrode portion 33 at a predetermined interval, and is electrically connected to the magnetoresistive film 32 to extend toward the side of the upper surface of the magnetoresistive element substrate 31. An extraction electrode unit 34 is provided. A protective film 35 is provided so as to cover at least the extraction electrode portion 34, the short-circuit electrode portion 33, and the magnetoresistive film 32. Further, a window is formed in the protective film 35 so as to be electrically connected to the extraction electrode portion 33, and a bump electrode 36 is provided by plating or the like in the portion where the window is formed, thereby forming a magnetoresistive element chip.

A method of manufacturing the magnetic sensor configured as described above will be described below.

First, the first magnetoresistive element chip 11 and the second magnetoresistive element chip 12 are mounted on the first magnetoresistive element chip mounting section 21 and the second magnetoresistive element chip mounting section 22 of the substrate 1. Then, one of the first magnetoresistive element chip bump electrodes 41 of the first magnetoresistive element chip 11
The output wiring 24 is electrically connected to the other second magnetoresistive element chip bump electrode 42 via the power supply wiring extension 27 and the first output wiring extension 26, respectively.

Next, the ground wiring 25 is connected to one third magnetoresistive element chip bump electrode 43 of the second magnetoresistive element chip 12, and the output wiring 24 is connected to the other fourth magnetoresistive element chip bump electrode 44. , The ground wiring extension part 29,
Electrical connection is made via the second output wiring extension 28.

Finally, a resin is injected from the side surfaces of the first and second magnetoresistive element chips 11 and 12 to the inside of the resin insertion holding portion 13 and molded.

FIG. 1 shows a magnetic sensor constructed as described above.
As shown in FIG. 2, a bias circuit 61 is provided on a surface of a bias magnet 61 fixed to a holder (not shown in this drawing) having a processing circuit (not shown in this drawing). , Not shown.) To be a magnetic detector.

The operation of the magnetic detector configured as described above will be described below.

FIG. 8 is a diagram for explaining the operation of the magnetic detector according to one embodiment of the present invention.

A rotating gear-shaped magnetic body 73 having a projection 72 is arranged close to the case 71, and when the magnetic body 73 is rotated, the first and the second magnets provided on the surface of the bias magnet 61 in the case 71 are arranged. 2 magnetoresistive element chips 11 and 12
And the bias magnet 61 to form a magnetic path. At this time, the first and second positions depend on the relative position of the projection 72 and the bias magnet 61.
Since the magnetic flux density applied to the second magnetoresistive element chips 11 and 12 changes, this change is used as an electric signal to output the wiring 2
4

Although the substrate 1 is a flexible film having various wirings in this embodiment, it may be formed of a lead comb having only various wirings.

The first and second magnetoresistive element chips 1
Although the first and second bump electrodes 36 are formed to fill the width of the magnetoresistive element substrate 31 in the width direction, the bump electrodes 82 are provided at diagonal positions in the longitudinal direction of the magnetoresistive element substrate 81 as shown in FIG. This has the effect of reducing the size of the resistance element chip.

In the present embodiment, the resin insertion holding portion 1
Although 3 is formed by bending the substrate 1 on the lower surface side, similar effects can be obtained by forming the substrate 3 by bending it upward as shown in FIG.

[0032]

As described above, the present invention has an effect that the fluctuation of the temperature-dependent characteristic is small.

[Brief description of the drawings]

FIG. 1 is a top view of a magnetic sensor according to an embodiment of the present invention.

FIG. 2 is a sectional view of the same.

FIG. 3 is a schematic view of the same.

FIG. 4 is a top view of a substrate provided with various wirings, which are essential parts of the same.

FIG. 5 is a cross-sectional view of a substrate which is a main part of the same.

FIG. 6 is a perspective view of a magnetoresistive element chip as a main part of the same.

FIG. 7 is a sectional view of a magnetoresistive element chip as a main part of the same.

FIG. 8 is a view for explaining the operation of the magnetic detector.

FIG. 9 is a perspective view of a magnetoresistive element chip according to another embodiment of the present invention.

FIG. 10 is a sectional view of a substrate according to another embodiment of the present invention.

FIG. 11 is a perspective view of a conventional magnetic sensor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 11 1st magnetoresistive element chip 12 2nd magnetoresistive element chip 13 Resin insertion holding part 21 1st magnetoresistive element chip mounting part 22 2nd magnetoresistive element chip mounting part 30 Resin mold

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tetsuo Kawasaki 1006 Kazuma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Masako Yamaguchi 1006 Kazuma Kadoma Kadoma City, Osaka Matsushita Electric Industrial F Term (reference) 2G017 AB05 AC06 AD55 AD61 AD65 5D034 BA02 BB02 DA07

Claims (6)

[Claims] 1. A first and a second magnetoresistive element chip insertion portion each having a power supply electrode and a power reception electrode therein, and the first and second magnetoresistive element chip insertion portions.
A power supply wiring so as to be electrically connected to a power supply electrode in the magnetoresistive element chip insertion portion, and a ground wire so as to be electrically connected to the power receiving electrode in the second magnetoresistive element chip insertion portion, and the first wiring. A substrate including an output wiring so as to be electrically connected between a power receiving electrode in the magnetoresistive element chip insertion portion and a power supply electrode in the second magnetoresistive element chip insertion portion; The first and second magnetoresistive element chips provided so as to be electrically connected to the power supply electrode and the power receiving electrode in the second magnetoresistive element chip insertion portion, respectively, and at least the first and second magnetoresistive element chips. A magnetic sensor comprising a resin mold provided to cover a side surface. 2. The magnetic sensor according to claim 1, wherein the substrate is made of one of a lead comb and a flexible film having various wirings. 3. The substrate has a resin insertion holding portion near the first and second magnetoresistive element chip insertion portions, and side surfaces of the resin insertion holding portion and the first and second magnetoresistive element chips. 2. The magnetic sensor according to claim 1, wherein the magnetic sensor is formed by resin molding. 4. A first and a second magnetoresistive element chip insertion portion each having a power supply electrode and a power reception electrode therein, and the first and second magnetoresistive element chip insertion portions.
A power supply wiring so as to be electrically connected to a power supply electrode in the magnetoresistive element chip insertion portion, and a ground wire so as to be electrically connected to the power receiving electrode in the second magnetoresistive element chip insertion portion, and the first wiring. An output wiring so as to be electrically connected between a power receiving electrode in the magnetoresistive element chip insertion section and a power supply electrode in the second magnetoresistive element chip insertion section; and the first and second magnetoresistive elements The resin insertion holding portion of the substrate provided with the resin insertion holding portion in the vicinity of the chip insertion portion is bent downward, and the resin insertion holding portion is bent and the first and second magnetoresistive element chip insertion portions of the substrate are bent. First, the power supply electrode and the power reception electrode are electrically connected to each other.
A method for manufacturing a magnetic sensor, comprising: forming a second magnetoresistive element chip; and then injecting and molding a resin from at least the side surfaces of the first and second magnetoresistive element chips to the inside of the resin insertion holding section. 5. A first and a second magnetoresistive element chip insertion portions each having a power supply electrode and a power reception electrode therein, and the first and second magnetoresistive element chip insertion portions.
A power supply wiring so as to be electrically connected to a power supply electrode in the magnetoresistive element chip insertion portion, and a ground wire so as to be electrically connected to the power receiving electrode in the second magnetoresistive element chip insertion portion, and the first wiring. An output wiring so as to be electrically connected between a power receiving electrode in the magnetoresistive element chip insertion section and a power supply electrode in the second magnetoresistive element chip insertion section; and the first and second magnetoresistive elements The power supply wiring and the power receiving wiring in the first and second magnetoresistive element chip insertion parts of the substrate having the resin insertion holding part near the chip insertion part are bent upward, and the power supply wiring and the power supply wiring in the magnetoresistive element chip insertion part are bent upward. First and second magnetoresistive element chips are formed so as to be electrically connected to the power supply electrode and the power receiving electrode in the first and second magnetoresistive element chip insertion portions of the substrate with the power receiving wiring bent. Method for producing a subsequent at least the first magnetic sensor from the side surface of the second magnetoresistive element chip formed by internal injecting resin toward molded of the resin insertion holder. 6. The method for manufacturing a magnetic sensor according to claim 4, wherein the step of bending the resin insertion holding portion of the substrate is a step of bending the resin insertion holding portion within the thickness of the first and second magnetoresistive element chips.