JP3085100B2 - Magnetoelectric conversion element - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetoelectric conversion element in which a magnetoresistance effect layer is formed on a magnetic substrate.

[0002]

2. Description of the Related Art Conventionally, a magnetoelectric conversion element in which a magnetoresistance effect layer made of InSb or the like having a magnetoresistance effect is formed on a substrate made of an insulating material or a magnetic material has a thickness,
It is widely used as an element for constituting a sensor for detecting an angle, a rotation speed, and the like. The structure of such a magneto-electric transducer is described with reference to FIG. 2, 4 and 5.

FIG . 4 is a cross-sectional view of a conventional magneto-electric transducer 20 in which a magnetic substrate 1 has a meandering InS
The magnetoresistive layer 2 made of a thin film b is bonded by an adhesive layer 3 made of a thermosetting resin such as an epoxy resin. Further, the magnetoresistive layer 2 having the meander line shape has a short bar having electrical conductivity. . .
4 are formed in large numbers. In the partial plan view of FIG.
Toba-4. . . . 4 shows the magnetoresistive effect layer 2 on which 4 is formed. As shown in FIG. 2, electrodes 5, 5 for connecting connection terminals (not shown) for electrically connecting to an external element are formed at both ends of the magnetoresistive layer 2.

FIG. 5 shows a method of manufacturing such a magnetoelectric conversion element .
This will be described with reference to FIG.

First, an InSb wafer 6 is prepared. One surface of the InSb wafer 6 is mirror-polished, and the polished surface is entirely etched. Next, as shown in FIG. 5A , an electrode material 7 is formed by depositing an electrode material such as Al on the InSb wafer 6 by vapor deposition or sputtering. Next, as shown in FIG . . . . 4 and connection electrodes 5, 5
Formed. Next, as shown in FIG. 5C , the InSb wafer 6 is formed into a meander line shape by photolithography to form the magnetoresistive layer 2. 7. Grooves for simultaneously separating individual magneto-electric conversion elements 20 here . . . 8 are also formed. Next, as shown in FIG. 5 (4), the surface of the InSb wafer 6 where the magnetoresistive layer 2 is formed is bonded to the magnetic substrate 1 by an adhesive layer 3 made of a thermosetting resin such as an epoxy resin. Next, as shown in FIG.
The nSb wafer-6 is placed in the groove 8. . . . By grinding to the bottom surface of 8, a magnetic substrate 1 on which a large number of magnetoelectric conversion elements 20 are independently formed is obtained. Next, grooves are formed by dicing. . . . 8 to obtain a magnetoelectric conversion element 20.

[0006]

However, in the conventional magnetoelectric transducer, when the surface on which the short bar and the magnetoresistive layer are formed is adhered to the magnetic substrate with an epoxy resin, the magnetoresistive shrinkage of the resin causes the magnetoresistance. Cracks sometimes occurred in the effect layer. Further, the epoxy resin may not sufficiently enter the surface on which the magnetoresistive layer is formed, and air bubbles may be generated in such a portion, so that the edge of the magnetoresistive layer may be chipped or the short bar may fall off.

SUMMARY OF THE INVENTION The present invention has been devised to solve the above problems, and forms a protective layer having a stress relaxing effect to protect a short bar and a magnetoresistive layer.

[0008]

According to a first aspect of the present invention, there is provided a magnetoelectric conversion element, wherein a magnetoresistance effect layer having a protective film made of a resin having a stress relaxation effect is formed on a substrate .
The magnetoresistive layer has a short bar having electrical conductivity.
Is formed on the magnetic substrate via the protective film.
The surface of the magnetoresistive layer on which the short bar is formed
Is characterized by being adhered.

[0009]

According to the magneto-electric conversion element of the present invention, a magneto-resistance effect layer having a protective film having a stress relieving effect is formed on a substrate and adhered to a magnetic substrate via the protective film. Cracks are not generated in the effect layer due to the stress caused by curing shrinkage of the resin, and the short bar is not dropped.

[0010]

(Embodiment 1) A magnetoelectric transducer according to an embodiment of the present invention will be described below with reference to FIGS. Note that the same parts as those in the conventional example are denoted by the same reference numerals, and description thereof will be omitted.

FIG. 1 is a sectional view of a magnetoelectric conversion element 10 according to the present embodiment. The magnetoelectric conversion element 10 includes a magnetoresistive layer 2 made of an InSb thin film having a meandering line shape, and a show having electrical conductivity formed on the magnetoresistive layer 2.
Toba-4. . . . 4 is covered with a protective layer 3a made of a resin such as polyimide having a stress relaxation effect, and the surface on which the protective layer 3a is formed is bonded to the magnetic substrate 1 by an adhesive layer 3 made of a thermosetting resin such as an epoxy resin. It has a structure. Short bar is shown in the partial plan view of FIG.
4. . . . 4 shows the magnetoresistive effect layer 2 on which 4 is formed. As shown in FIG. 2, electrodes 5, 5 for connecting connection terminals (not shown) for electrically connecting to an external element are formed at both ends of the magnetoresistive layer 2.

FIG. 3 shows a method of manufacturing such a magnetoelectric conversion element.
This will be described with reference to FIG.

First, an InSb wafer 6 is prepared. One surface of the InSb wafer 6 is mirror-polished, and the polished surface is entirely etched. Next, as shown in FIG. 3A, an electrode material such as Al is first deposited on the InSb wafer 6 by vapor deposition or sputtering to form an electrode material 7. Next, as shown in FIG. . . . 4 and connection electrodes 5 and 5. Next, as shown in FIG.
The wafer b is formed into a meander line shape by photolithography to form the magnetoresistive layer 2. 7. Grooves for simultaneously separating individual magneto-electric conversion elements 20 here . . . 8 are also formed. Next, as shown in FIG. 3D, an organic solvent solution of polyimide is applied by a spin coating method, dried at 90 ° C. for 30 minutes, and then cured at 350 ° C. for 2 hours to form a protective layer 3a. Next, as shown in FIG. 3 (5), the magnetic substrate 1 is bonded to the surface on which the protective layer 3a is formed via an adhesive layer 3 made of a thermosetting resin such as an epoxy resin.
Next, as shown in FIG. . . . By grinding to the bottom surface of 8, a magnetic substrate 1 on which several other magneto-electric conversion elements 10 are independently formed is obtained. Next, grooves 8 are formed with a dicing saw. . . . 8 and the magnetoelectric conversion element 10 is obtained.

The present invention is not limited to the above embodiments. The electrode material may be other metal materials such as Cu and Au in addition to Al, or may be Ti / Al or Ti / Ni / Al.
Etc. may be used.
It goes without saying that an alloy such as Cu may be used.

As a material for forming the protective layer , an inorganic material
A material such as silica (SiO2), silicon oxide (SiO), or silicon nitride (SiNx) may be formed by sputtering or vapor deposition.

[0016]

According to the magnetoelectric transducer of the present invention, the surface on which the magnetoresistive layer is formed is covered with a protective layer made of a resin having a stress relaxation effect, whereby the thermosetting resin for bonding to the magnetic substrate is cured. The effect of shrinkage could be eliminated. Therefore, cracks and chips in the magnetoresistive layer and falling off of the short bar were greatly reduced. As a result, the yield rate can be improved, and the thickness of the magnetoresistive layer can be increased, so that restrictions on pattern design can be reduced.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a magnetoelectric conversion element according to an embodiment of the present invention.

FIG. 2 is a partial plan view of a magnetoelectric conversion element according to an embodiment of the present invention.

FIG. 3 is a diagram showing a manufacturing process of the magneto-electric conversion element according to one embodiment of the present invention;

FIG. 4 is a sectional view of a conventional magnetoelectric conversion element.

FIG. 5 is a view showing a state in the course of manufacturing a conventional magnetoelectric conversion element.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Magnetic substrate 2 Magnetoresistive layer 3 Adhesive layer 3a Protective layer 4 Short bar 5 Connection electrode 6 InSb wafer 7 Electrode material 8 Groove 10, 20 Magnetoelectric conversion element

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01L 43/08

Claims (1)

(57) [Claims] 1. A magnetoresistive layer having a protective layer of a resin having the stress relaxation effect is formed on the substrate, further, the magnetic
A short bar with electrical conductivity is formed in the air resistance effect layer
It made which are, the magnetic to the magnetic substrate via the protective film
A magnetoelectric conversion element characterized in that the surface of the air resistance effect layer on which the short bar is formed is adhered.