JPH07235710A - Magnetoresistive - Google Patents

Abstract

PURPOSE:To reduce variations of resistance of a magnetic sensitive part by bonding on a magnetic substrate a magnetoresistive device pattern having a pair of magnetic sensitive parts and an auxiliary pattern with a resin layer. CONSTITUTION:A lead electrode 8 of a magnetoresistive device pattern 2a including a pair of magnetic sensitive parts 5, 5 is disposed at a location held between the pair of the magnetic sensitive parts 5, 5. External connection terminals 4, 4, 4 connected with a connection electrode and a lead electrode 8 are led from the same end surface. When the magnetoresistive device pattern 2a formed with etching is bonded with a magnetic substrate 1 through a resin layer 10, the amount of resin entering between the magnetic sensitive parts is reduced so that contraction stress due to hardening and contraction of the resin layer 10 can be moderated. For this, pattern deformation of the magnetoresistive, device pattern 2a is reduced to prevent the pattern from being broken and hence reduce variations of resistance of the magnetic sensitive part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetoresistive element having a magnetic sensitive section made of a semiconductor on a magnetic substrate.

[0002]

2. Description of the Related Art Conventionally, magnetoresistive elements and hole elements have been constructed using InSb compound semiconductors. A conventional magnetoresistive element will be described with reference to FIGS. 8, 9 and 10.
8 is an external perspective view of a conventional magnetoresistive element, FIG. 9 is a cross-sectional view taken along the line AA in FIG. 8, and FIG. 10 is a plan view showing a magnetoresistive element pattern forming a magnetoresistive element. Is.

The magnetoresistive element 60 comprises a magnetic substrate 1, a magnetoresistive element pattern 2, a protective film 3, and external connection terminals 4, 4, and 4.
It has a structure with. The magnetoresistive element pattern 2 includes a pair of magnetically sensitive portions 5 and 5, which are symmetrical to each other, connection electrodes 6 and 6 respectively connected to one end side of the magnetically sensitive portions 5 and 5, and the magnetically sensitive portions 5 and 5, respectively. Has a structure in which a connecting electrode 7 connecting the other end sides of the connecting electrode 7 and an extraction electrode 8 connected to the connecting electrode 7 are integrated, and is composed of a resin layer 10 on the magnetic substrate 1. .

The magnetically sensitive portions 5 and 5 are formed by forming InSb thin films 5a and 5a formed in a meandering line shape, and folding portions of the InSb thin films 5a and 5a and a predetermined interval at several points in the middle. It is composed of a short-circuit film 5b made of Al and Ti. Further, the connection electrodes 6, 6, the connection electrode 7, and the extraction electrode 8 are InSb thin films (not shown) continuous with the InSb thin films 5a, 5a and A formed thereon.
It is composed of metal films 6b, 6b, 7b and 8b made of 1 and Ti. The protective film 3 is formed so as to cover the magnetoresistive element pattern 2 except for a part of the connection electrodes 6, 6 and the extraction electrode 8. The external connection terminals 4, 4, 4 are connected to the exposed portions of the connection electrodes 6, 6 and the extraction electrode 8.

The above-described magnetoresistive element 60 detects the change in the external magnetic field by taking out the difference in the resistance values of the pair of magnetic sensitive parts 5 and 5 by the extraction electrode 8 and the connection electrode 6 by such a structure. .

The manufacturing process of the conventional magnetoresistive element 60 will be described below in order.

First, an InSb thin film is formed on a mica substrate by vapor deposition by a three-temperature method. This InSb thin film is formed by photolithography and etching to form a pair of symmetrical InSb thin films 5a and 5a and a continuous InSb thin film (not shown). Etching is performed until the shape of the InSb thin film layer is completely formed.
It is performed by impregnating it with an aqueous ferric chloride solution which is an etching solution.
Next, by vacuum deposition and photolithography, Al,
The short-circuit film 5b made of Ti and the metal films 6b, 7b, 8b are I
A magnetoresistive element pattern 2 is obtained by forming it on the nSb thin film. Then, after the magnetoresistive element pattern 2 is arranged on the magnetic substrate 1 with the resin layer 10 interposed therebetween, the resin layer 10 is heat-treated.
Is cured to bond the magnetic substrate 1 and the magnetoresistive element pattern 2 together. After peeling and removing the mica substrate, the protective film 3 for protecting the magnetoresistive element pattern 2 is removed except for the connection portions of the connection electrodes 6, 6 connecting the external connection terminals 4, 4, 4 and the extraction electrode 8. It is formed on the upper surface of the magnetoresistive element pattern 2. Then, the external connection terminals 4, 4, 4 are connected to the connection electrodes 6, 6, and the extraction electrode 8 by a thermocompression bonding method or the like to obtain the magnetoresistive element 60.

[0008]

However, when the magnetoresistive element 60 having such a structure is applied to an object to be detected having a large pitch, it is necessary to increase the distance between the pair of magnetic sensitive parts 5, 5.

If such a structure is adopted, the amount of etching of the InSb thin film formed on the entire surface of the central portion is increased, so that the side surfaces of the magnetic sensitive portions 5 and 5 on the central side are excessively etched and the magnetic sensitivity is increased. The shapes of the parts 5 and 5 were sometimes thin. For this reason, the variations in the resistance values of the magnetically sensitive portions 5 and 5 become large. Further, when the surface on which the magnetoresistive element pattern 2 is formed is adhered to the magnetic substrate 1 by the resin layer 10, a large amount of resin enters between the magnetic sensitive parts, so that the shrinkage force generated during curing of the resin layer 10 becomes large. Accordingly, the shape of the magnetoresistive element pattern may be collapsed or the pattern may be destroyed by the tensile stress due to the contracting force.

An object of the present invention is to solve the above-mentioned problems, and it is an object of the present invention to provide a highly reliable magnetoresistive element with a small variation in the resistance value of the magnetic sensing part.

[0011]

In the magnetoresistive element of the present invention, a magnetoresistive element pattern having a pair of magnetic sensitive parts and an auxiliary pattern are adhered on a magnetic substrate by a resin layer. Is characterized by.

The magnetoresistive element of the present invention is characterized in that an auxiliary pattern is arranged between a pair of magnetic sensitive sections.

[0013]

By providing an auxiliary pattern on the magnetoresistive element pattern to reduce the area for etching the InSb thin film layer, the side etching amount is reduced and the etching accuracy of the entire pattern is improved. Further, when the resin is adhered to the substrate, the amount of the resin that enters between the patterns is reduced, so that the shrinkage stress of the resin is relieved.

[0014]

【Example】

(Example 1) A magnetoresistive element 20 according to Example 1 of the present invention.
Will be described in detail with reference to FIGS. 1 is an external perspective view of the magnetoresistive element 20, and FIG.
3 is a sectional view taken along the line AA shown in FIG. 3, FIG. 3 is a plan view of the magnetoresistive element pattern 2a constituting the magnetoresistive element 20, and FIG. 4 is a plan view of the magnetoresistive element 20. Further, the same parts as those of the conventional example are designated by the same reference numerals, and the description thereof will be omitted.

The characteristic of the magnetoresistive element 20 of this embodiment is that the extraction electrode 8 of the magnetoresistive element pattern 2a having the pair of magnetic sensitive portions 5 and 5 is sandwiched between the pair of magnetic sensitive portions 5 and 5. It has a structure arranged in parts. That is, the extraction electrode 8
Has a rectangular shape, and the magnetoresistive element pattern 2 is formed on the upper surface of the magnetoresistive element 20 in the vicinity of one side surface 1a.
It extends from the connecting electrode 7 of a to the vicinity of the other opposite side surface 1b, and is arranged in a portion sandwiched by the pair of magnetic sensitive portions 5, 5. The external connection terminals 4, 4, 4 connected to the connection electrodes 6, 6 and the extraction electrode 8 are drawn out from the same end face.

Therefore, the area of the portion between the pair of magnetic sensitive portions 5 and 5 to be removed by etching is reduced, and the magnetoresistive element pattern is formed.
Since it becomes possible to uniformly etch the whole 2a,
The accuracy of the magnetoresistive element pattern 2a is improved. Further, when the magnetoresistive element pattern 2a formed by etching is bonded to the magnetic substrate 1 by the resin layer 10, the amount of resin entering between the magnetic sensitive parts is reduced, so that shrinkage stress due to curing shrinkage of the resin layer 10 can be relaxed. The pattern collapse of the magnetoresistive element pattern 2a is reduced, and the pattern is not destroyed.

The magnetoresistive element 20 of the above-mentioned embodiment is manufactured by the same process as the manufacturing process shown in the prior art, and the shape of the magnetoresistive element pattern 2a and the shape at the same position on the photomask are thinned (side etching). (Width) was compared and measured by an optical microscope, and was below the measurement limit value. Further, when the magnetoresistive element pattern 2a was adhered to the magnetic substrate 1 by the resin layer 10, no deformation of the magnetic sensitive parts 5, 5 could be confirmed.

The completed magnetoresistive element 20 was mounted on a printed circuit board wired with Cu using a commercially available cream solder, and an evaluation test was conducted. As a result, 25 ℃, 3
The rate of change in magnetoresistance under a magnetic field at 000 G was 3.3. In a thermal shock test in which the temperature was raised and lowered 10 times between −40 ° C. and 120 ° C., the resistance variation was 3% or less, which was 1/3 or less of the magnetoresistance change rate of the magnetoresistive element according to the conventional design. The above values are values that satisfy the standards.

(Embodiment 2) A magnetoresistive element according to an embodiment of the present invention will be described in detail with reference to FIG. FIG. 5 is a plan view of a magnetoresistive element pattern 30a forming the magnetoresistive element. The same parts as those of the conventional example are designated by the same reference numerals,
The description is omitted.

A characteristic of the magnetoresistive element of the present embodiment is that the auxiliary pattern 15 is arranged in a portion sandwiched by a pair of magnetic sensitive portions 5, 5. That is, the auxiliary pattern
The rectangular shape 15 has a rectangular shape and extends from the connecting electrode 7 of the magnetoresistive element pattern 30a formed on the upper surface in the vicinity of one side surface 1a of the magnetoresistive element to the vicinity of the other side surface 1b which faces the side surface 1a. It is arranged in the portion sandwiched by the magnetic portions 5, 5.

Therefore, the area of the portion between the pair of magnetic sensitive portions 5 and 5 to be removed by etching is reduced, and the magnetoresistive element pattern is formed.
Since the entire pattern 30a can be uniformly etched, the accuracy of the magnetoresistive element pattern 30a is improved. Further, the magnetoresistive element pattern 30 formed by etching
When a is adhered to the magnetic substrate 1 with a resin layer, the amount of resin entering between the magnetic sensitive parts is reduced, so that the contraction stress due to the curing contraction of the resin layer can be relaxed, so that the pattern of the magnetoresistive element pattern 30a can be reduced.
The collapse is reduced.

The magnetoresistive element according to the present example was also evaluated by the same method as in Example 1. As a result, the shape collapse could not be confirmed by observing the pattern shape with an optical microscope, and the same result was obtained in the evaluation test and the thermal shock test. The result was obtained.

(Embodiment 3) A magnetoresistive element according to an embodiment of the present invention will be described in detail with reference to FIG. FIG. 6 is a plan view of a magnetoresistive element pattern 40a forming the magnetoresistive element. The same parts as those of the conventional example are designated by the same reference numerals,
The description is omitted.

The feature of the magnetoresistive element of this embodiment is that the extraction electrode 8 of the magnetoresistive element pattern 40a having the pair of magnetic sensitive portions 5 and 5 is sandwiched between the pair of magnetic sensitive portions 5 and 5. And has a structure in which the connection electrodes 6, 6 are respectively extended between the magnetic sensitive portions 5, 5 and the side surfaces 1c, 1d of the magnetoresistive element. That is, the extraction electrode 8 has a rectangular shape and extends from the connecting electrode 7 of the magnetoresistive element pattern 40a formed on the upper surface in the vicinity of one side surface 1a of the magnetoresistive element to the vicinity of the other side surface 1b which faces the magnetoresistive element. It is arranged in a portion sandwiched between the magnetic sensitive portions 5 and 5. Further, each of the connection electrodes 6, 6 is located between one of the magnetic sensitive portions 5, 5 and the side surface 1c, 1d of the magnetoresistive element and one side surface 1 of the magnetoresistive element.
It is extended to the vicinity of a and 1b. Furthermore, the connection electrode 6,
External connection terminals 4, 4, 4 connected to 6 and the extraction electrode 8 are drawn out from the same end face.

Magnetoresistive element pattern 4 having the above structure
In the case of 0a, the area of the portion to be removed by etching between the pair of magnetic sensitive portions 5 and 5 is reduced, so that the magnetoresistive element pattern 40 is formed.
Since the entire a can be etched uniformly, the accuracy of the magnetoresistive element pattern 40a is improved. Further, when the magnetoresistive element pattern 40a formed by etching is adhered to the magnetic substrate 1 with the resin layer, the amount of resin entering between the magnetic sensitive parts is reduced, so that the shrinkage stress due to the curing shrinkage of the resin layer can be relaxed, so that the magnetic resistance is reduced. The pattern collapse of the element pattern 40a is reduced.

The magnetoresistive element according to this example was also evaluated in the same manner as in Example 1. As a result, the shape collapse could not be confirmed by observing the pattern shape with an optical microscope, and the same result was obtained in the evaluation test and the thermal shock test. The result was obtained.

(Embodiment 4) A magnetoresistive element according to an embodiment of the present invention will be described in detail with reference to FIG. FIG. 7 is a plan view of a magnetoresistive element pattern 50a constituting the magnetoresistive element. The same parts as those of the conventional example are designated by the same reference numerals,
The description is omitted.

The magnetoresistive element of this embodiment is characterized in that the auxiliary pattern 1 is formed on almost the entire surface except for the magnetoresistive element pattern 50a.
5 has the structure arranged. That is, the auxiliary pattern 15 is arranged between the meander lines of the magnetic sensitive parts 5 and 5,
It is provided between the magnetic sensitive portions 5 and 5, and between the magnetic sensitive portions 5 and 5 and the side surfaces 1a, 1b, 1c and 1d of the magnetoresistive element.

Magnetoresistive element pattern 5 having the above structure
In the case of 0a, the area of the portion to be removed by etching between the pair of magnetic sensitive portions 5 and 5 is reduced, so that the magnetoresistive element pattern 50a.
Since the whole can be etched uniformly, the accuracy of the magnetoresistive element pattern 50a is improved. Further, when the magnetoresistive element pattern 50a formed by etching is adhered to the magnetic substrate 1 with the resin layer, the amount of the resin entering between the magnetic sensitive parts is reduced, so that the shrinkage stress due to the curing shrinkage of the resin layer can be relaxed, so that the magnetic resistance can be reduced. The pattern collapse of the element pattern 50a is reduced.

The magnetoresistive element according to this example was also evaluated in the same manner as in Example 1. As a result, the shape collapse could not be confirmed by observing the pattern shape with an optical microscope, and the same result was obtained in the evaluation test and the thermal shock test. The result was obtained.

The magnetoresistive element of the present invention has been described above with reference to Examples 1 to 4, but the present invention is not limited to this, and various modifications can be made within the scope of the present invention. You can In the embodiment described above, the external connection terminal 4,
Although the structure for connecting by using 4 and 4 is adopted, an electrode for external connection may be provided at the end of the element for surface mounting.

[0032]

The magnetoresistive element according to the present invention has a structure in which a magnetoresistive element pattern having a pair of magnetic sensitive portions and an auxiliary pattern are bonded to a magnetic substrate by a resin layer. . Therefore, the side etching amount at the time of etching the magnetoresistive element pattern is improved, and the precision of the pattern is improved. Further, since the tensile stress due to the contracting force of the resin when the magnetoresistive element pattern is bonded to the substrate is relaxed, it is possible to prevent the pattern from collapsing or breaking.

Therefore, according to the magnetoresistive element of the present invention, the variation in the resistance value of the magnetic sensitive portion is small and the reliability can be improved.

[Brief description of drawings]

FIG. 1 is an external perspective view showing a magnetoresistive element according to a first embodiment of the present invention.

FIG. 2 is a sectional view showing a magnetoresistive element according to Example 1 of the present invention.

FIG. 3 is a plan view showing a magnetoresistive element pattern and an auxiliary pattern of the magnetoresistive element according to the first embodiment of the present invention.

FIG. 4 is a plan view showing a magnetoresistive element according to Example 1 of the present invention.

FIG. 5 is a plan view showing a magnetoresistive element pattern and an auxiliary pattern of a magnetoresistive element according to Example 2 of the present invention.

FIG. 6 is a plan view showing a magnetoresistive element pattern and an auxiliary pattern of a magnetoresistive element according to a third embodiment of the present invention.

FIG. 7 is a plan view showing a magnetoresistive element pattern and an auxiliary pattern of a magnetoresistive element according to Example 4 of the present invention.

FIG. 8 is an external perspective view showing a conventional magnetoresistive element.

FIG. 9 is a cross-sectional view showing a conventional magnetoresistive element.

FIG. 10 is a plan view showing a magnetoresistive element pattern of a conventional magnetoresistive element.

[Explanation of symbols]

1 Magnetic Substrate 1a, 1b, 1c, 1d Side Surfaces 2, 2a, 30a, 40a, 50a Magnetoresistive Element Pattern 3 Protective Film 4 External Connection Terminal 5 Magnetosensitive Section 5a InSb Thin Film 5b Short Circuit Film 6 Connection Electrode 6b, 7b , 8b Metal film 7 Connection electrode 8 Extraction electrode 10 Resin layer 15 Auxiliary pattern
20 Magnetoresistive element

Claims (2)

[Claims] 1. A magnetoresistive element pattern having a pair of magnetically sensitive portions.
A magnetoresistive element in which an auxiliary pattern and an auxiliary pattern are adhered on a magnetic substrate by a resin layer. 2. The magnetoresistive element according to claim 1, wherein the auxiliary pattern is arranged between the pair of magnetic sensitive portions.