JPH0223036B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic detection sensor device, and particularly to a structure of wiring for external connection of a magnetoresistive element having a magnetoresistive effect.

A magnetic detection sensor device using a magnetic detection element that has been proposed in the past includes, for example, a magnetoresistive device having a magnetoresistive effect formed on a non-magnetic substrate 1, as shown in FIG. The element 2 has a structure that measures the rotational speed of a magnetic body 3 to be detected, such as a gear or a magnet, by changing the magnetic flux of a bias magnet 4. However, in the case of the above structure, the external connection lead 5 from the magnetoresistive element 2 uses a bonding wire 6 such as a gold wire in the middle, and for packaging, the case 7 and cap 8 made of non-magnetic metal are connected. If you glue and mold with epoxy resin 9, for example,
The bonding wire 6 may be cut due to a slight difference in thermal expansion, the bonding wire 6 may come into contact with the cap 8 due to slackness, and since wire bonding is performed, the bonding wire 6 may be disconnected from the surface of the cap 8 to the surface of the magnetoresistive element 2. As the distance d becomes longer, the distance from the magnetic body 3 to be detected to the plane of the magnetoresistive element 2 becomes longer, resulting in various drawbacks such as a decrease in the sensitivity of the magnetoresistive element 2.

Therefore, an object of the present invention is to provide a highly sensitive and reliable magnetic detection sensor device by drawing out at least a part of the external connection wiring from the magnetoresistive element using a flexible wiring board. It is said that Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 2 is a sectional view of a main part corresponding to FIG. 1 showing an example of a magnetic detection sensor device according to the present invention, and since the same symbols as in FIG. 1 represent the same elements, a description thereof will be omitted. In FIG. 2, one end of a polyimide flexible wiring board 10 is electrically connected to a bonding pad (not shown) of the magnetoresistive element 2, and the other end is electrically connected to an external connection lead 5 via a resectable 11. connected. In this case, the magnetoresistive element 2 and the flexible wiring board 1
0 can be easily connected by means such as thermocompression bonding or soldering. The magnetoresistive element 2 is molded with epoxy resin 9 on the inner surface of the cap 8 with a flexible wiring board 10 interposed therebetween.

According to such a configuration, the problem of cutting the bonding wire 6 (see FIG. 1) and connecting the cap 8 with conventional wire bonding is avoided.
There are no accidents caused by contact with the flexible wiring board 10 and the cap 8.
Since there is a polyimide overlay film on the outer surface of 0, it can be contacted. Furthermore, by using the flexible wiring board 10, it is possible to construct a film insulating layer with a thin and uniform thickness, and the magnetoresistive element 2 can be placed closest to the inner surface of the cap 8. The distance d from the surface of the cap 8 to the surface of the magnetoresistive element 2 can be significantly shortened, and the sensitivity of the magnetoresistive element 2 can be improved.

As explained above, according to the present invention, there is no disconnection or contact accident in the wiring for external connection of the magnetoresistive element, so reliability and yield can be significantly improved. Furthermore, since the distance between the magnetoresistive element and the magnetic body to be detected can be significantly shortened, it has extremely excellent effects such as obtaining a magnetic detection sensor device with high detection sensitivity.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a main part of an example of a conventional magnetic detection sensor device, and FIG. 2 is a sectional view of a main part of an example of a magnetic detection sensor device according to the present invention. 1... Non-magnetic substrate, 2... Magnetoresistive element, 4
...Bias magnet, 5...External connection lead,
7... Case, 8... Cap, 9... Epoxy resin, 10... Flexible wiring board, 11...
Resectable.

Claims (1)

[Claims] 1. A non-magnetic substrate, a magnetoresistive element having a magnetoresistive effect formed on the non-magnetic substrate, and a magnetoresistive element that covers at least a part of the surface of the magnetoresistive element opposite to the non-magnetic substrate. a flexible wiring board whose one end side is directly connected to the bonding pad portion of the magnetoresistive element and whose other end side constitutes at least a part of the external connection wiring; and a flexible wiring board that covers at least a part of the one end side of the flexible wiring board. A magnetic detection sensor device comprising: a non-magnetic metal plate disposed close to the flexible wiring board.