JPS6127690A - Magnetoresistance element - Google Patents

Abstract

PURPOSE:To shorten the manufacturing process while improving the reliability and to lower the cost, by forming a first conduction film on a substrate only of a material having magnetoresistance effect except for the portion of a junction terminal with the outside. CONSTITUTION:A first conduction layer, unlike conventional two-layer wired magnetoresistance element, is composed only of a permalloy film 2 having magnetoresistance effect, without any wiring layer. A part of the role that wiring layers in conventional elements have taken is performed by a wiring pattern with relatively low resistance which is formed on the permalloy film 2 in a thick and short area. A second conduction film 5 is extended beyond an interlayer insulation film 4 to a region where the insulation film 4 is not provided, and is directly contacted with the glass substrate 1 to form a junction terminal 5a with the outside.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention simplifies the manufacturing process of a two-layer wiring magnetoresistive element that has a large number of magnetic sensor patterns and requires complicated wiring between them. Regarding products with improved yield.

[Background of the invention]

The magnetic pattern on the surface of the magnetic drum or magnetic disk attached to the rotating body is read, and the rotation state of the rotating body (the reference point of the rotating body, the absolute rotation angle position from the reference point, and the method of increasing this rotation angle) Magnetoresistive elements for magnetic sensors that detect rotational speed, etc., are required to have high accuracy for each of the detection items mentioned above, and the types of magnetic sensor patterns used to actually read magnetic patterns are increasing.
Their shape, arrangement, density, wiring between patterns, etc. have gradually become more complex.

As seen in the precedent of semiconductor integrated devices, as magnetoresistive elements become more complex as described above, the number of terminals in the magnetic sensor pattern becomes extremely large (and the number of wires between them also becomes extremely large). If wiring is attempted using only one layer of conductive film, the wiring cannot cross without contact, and the overall size of the magnetoresistive element becomes extremely large, making it impractical in terms of reliability and cost. For this reason, conventionally, two layers of conductive layer wiring films with an interlayer insulating film sandwiched between them have been used to create 2M wiring, which allows for cross wiring. This was useful in reducing the number of connection terminals.

However, in the conventional 2N wiring magnetoresistive element, the first layer conductive film, which is first formed on the substrate, has a magnetic sensor pattern portion made of a material having a magnetoresistive effect, and a high conductivity material such as a first layer conductive film. The wiring pattern is made of aluminum, copper, etc., and the connection between the two parts must be made reliably, making the manufacturing process long, yields low, and reliability poor. There were problems such as not having one.

It should be noted that Japanese Patent Laid-Open No. 58-1401 discloses that the material of the magnetoresistive element wiring section is made different from that of the sensor section and has high conductivity.
The absolute magnetic sensor is discussed in Japanese Patent Application Laid-open No. 118259/1983.

Figure 2 (a) shows a top view of a conventional 2III wiring magnetoresistive element, Figure 2 (b) shows a connection diagram of the magnetic sensor pattern in this element, and Figure 3 shows a side sectional view of the conventional element. . In the figure, 1 is a glass substrate, 2 is a magnetic sensor pattern R1,
Permalloy film forming R2, R3, R4, 3 is sensor.
3a is the interlayer on top of the wiring film 3, which is made up of a chrome film that fits well in direct contact with the glass that performs part of the wiring between patterns, and an aluminum film with a slightly narrow width and good conductivity formed on top of the chrome film. The external connection terminal from which the insulating film has been removed, 4 is 5iO2IIli! and an interlayer insulating layer 5 made of a polyimide resin film laminated thereon, in this case, a chrome film that passes through the through hole and also connects the first layer conductive film and the second N conductive film. A second layer conductive film is made of a wiring pattern laminated with an aluminum film, 6 is a weather-resistant protective film made of an Sl film and a polyimide resin film laminated thereon, and 7 is a through hole. In addition, 5■, O
v is an external connection terminal 3a for connecting a DC power supply, and ■t'%z is for a magnetic field detection output signal. The reason why the wiring film is a laminated film of chrome and aluminum is that the chrome first ensures adhesion to the base, and the aluminum provides sufficiently good conductivity. In addition, the interlayer insulating film and weatherproof protective film are made by laminating a Si% film and a polyimide resin film.The reason is that the cracks that sometimes occur in the 5102 film are filled with an organic resin film to ensure insulation and weather resistance. This is to do so. Even if attention is paid to improving reliability in this way, sufficient reliability cannot be obtained for forming the first layer conductive film, which requires a longer and more complicated manufacturing process than the patterned film made of multiple types of materials as described above. The problem remained that it could not be done.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a magnetoresistive element that does not have the problems of the conventional two-layer wiring magnetoresistive element, has a simple and short manufacturing process, is highly reliable, and has a high yield.

[Summary of the invention]

In order to achieve the above object, in the present invention, the first layer conductive film is first formed on the substrate, and the main wiring pattern forming the second layer conductive film is formed directly on the substrate at the connection terminal portion with the outside. (relatively high-resistance sensor)
Both the pattern portion and the thick, short, relatively low resistance wiring pattern portion are formed entirely from a film of a substance having a magnetoresistive effect. By doing this,
The process of forming the first layer conductive film, which conventionally required a long manufacturing process, is shortened, yield and reliability are improved, and the cost is reduced accordingly.

(Embodiment of the invention) FIG. 1(a) is a top view of the embodiment of the present invention, No. 1111F
(b) is the connection diagram of the sensor pattern, and Fig. 1 (c) is the connection diagram of the sensor pattern.
) is a side sectional view of the same embodiment. The symbols in the figure are from Figure 2.
As in the case of Figure 3, as can be seen from Figure 1 (C),
Unlike the conventional two-layer wiring magnetoresistive element, the first layer conductive film is formed only of a permalloy film 2 having a magnetoresistive effect, and there is no wiring film 3. Part of the role played by the wiring film 3 in the case of conventional elements is compensated for by creating thick, short wiring pattern portions with relatively low resistance in the permalloy film 2. Instead, the second layer conductive film 5 extends beyond the interlayer insulating film 4 to a portion where this film is not formed, and directly contacts the glass substrate 1 to form a connection terminal 5a with the outside.

〔Effect of the invention〕

As explained above, according to the present invention, the manufacturing process is simplified, the reliability and yield are improved, and the cost is reduced.

[Brief explanation of drawings]

FIG. 1(a) is a top view of one embodiment of the present invention, FIG. 1(b) is a connection diagram of the sensor pattern, FIG. 1(C) is a side sectional view of the same embodiment, and FIG. Top view of magnetoresistive element, figure (
b) is a connection diagram of the sensor pattern, and FIG. 3 is a side sectional view of the same element. 2- Vermalon film, 3...- wiring film forming part of the first layer conductive film, 4- first interlayer insulating film, 5- second layer conductive film, 5a
・-・Connection terminal, 6...-Weather-resistant protective film, 7-Thru No. IF21 (C)

Claims (1)

[Claims] On the substrate, a first layer conductive film consisting of a number of magnetic sensor patterns for detecting the presence or absence of a magnetic field and wiring patterns connected to these sensor patterns, and an interlayer insulating film covering the first layer and having through holes. Further, a second conductive layer consisting of a wiring pattern is sequentially formed to cover the top of the conductive layer, and the conductive layer formed through the through hole connects the first conductive layer and the second conductive layer. In a two-layer wiring magnetoresistive element in which the wiring between the sensor and the pattern is completed as expected, the first layer conductive film is connected to the outside where the wiring pattern forming the second layer conductive film is formed directly on the substrate. Except for the terminal portion, both the elongated, relatively high-resistance sensor pattern portion and the thick, short, relatively low-resistance wiring pattern portion are all formed of only a film of a substance having a magnetoresistive effect. Magnetoresistive element.