JPH0577960U - Resin-molded magnetoresistive element - Google Patents

Abstract

(57) [Summary] [Structure] A resin-molded magnetoresistive element having a resin-molded portion with a positioning boss or cutout. [Effect] A holder is not required when mounting on a printed circuit board or the like. Further, since the positional relationship between the sensor portion and the boss portion or the cutout portion is uniquely determined, the sensor portion can be easily and highly accurately mounted on a printed circuit board or the like.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a magnetoresistive element using a ferromagnetic thin film, and particularly to a magnetoresistive element that requires precise positioning.

[0002]

[Prior Art]

 The magnetoresistive element is used as a sensor for rotation detection and position detection. As an example of a conventional resin-molded magnetoresistive element, FIG. 3 shows a magnetoresistive element 100 disclosed in Japanese Patent Laid-Open No. 61-23777. FIG. 3A is a plan view of the element and FIG. 3B is a side view thereof. In the figure, 2 is a magnetoresistive element chip made of a glass substrate, 3S is a sensor part made of a ferromagnetic thin film, and 5 is a terminal electrode part. Further, the magnetoresistive element chip 2 is adhered and fixed to the lead island 7I, and the chip and the lead portion 7 are electrically connected by the wire 8. The terminal electrodes and leads are molded and reinforced with a thermosetting mold resin 902. Generally, when mounting a magnetoresistive element, high accuracy of the position of the sensor unit is required. Therefore, the magnetoresistive element 100 is usually incorporated in a resin-molded holder 10 as shown in FIG. 4A as shown in FIG. 4B. That is, the head of the element 100 is brought into contact with the stopper portion 10S of the holder 10 and fixed with an adhesive or the like. At the time of mounting on a printed circuit board, the sensor section and the magnetic signal source are opposed to each other with an appropriate gap, for example, a space of about 100 μm, and the holder 10 incorporating the element 100 is fixed on the board for use. Molded elements have the advantage that they have a strong lead holding force and the chip is not easily damaged because the leads are resin-sealed together with the element chip, which makes the handling easier when mounting such as a holder. It's easy without anything. However, in the case of the above-mentioned structure, since the holder 10 and the element 100 are assembled by adhesion or the like, there is a problem that the positional relationship between the boss portion 10B of the holder and the sensor is different for each element. The reason for this is that there are variations in the thickness of the adhesive layer, and dimensional tolerances of the holder. In addition, the stopper portion 10S may be reproduced well and the head of the element 100 may not be applied, which causes a problem. Furthermore, because the two are combined, the tolerances tend to increase. In particular, since a thermoplastic resin with a large dimensional tolerance is usually used as the holder material, the positional accuracy after assembly was difficult. Also, since there is an adhesive layer, there is a problem that the adhesive may come off during long-term use.

[0003]

[Problems to be solved by the device]

 An object of the present invention is to solve the above-mentioned problems and to provide a resin-molded magnetoresistive element which can be positioned and need not be incorporated in a holder.

[0004]

[Means for Solving the Problems]

 In order to achieve such an object, the resin-molded magnetoresistive element of the present invention is characterized in that the resin-molded portion has a positioning boss or cutout.

[0005]

【Example】

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

[0006]

First Embodiment FIG. 1 shows a transfer mold type magnetoresistive element having a boss and a notch as a first embodiment of the present invention. 1A is a top view of the device, FIG. 1B is a plan view, and FIG. 1C is a cross-sectional view taken along the line AA. In this case, the magnetoresistive element chip 2 has a structure embedded in resin. In the figure, 2 is a magnetoresistive element chip made of a glass substrate, 3 is a ferromagnetic thin film, 3S is a sensor part made of a ferromagnetic thin film, 4 is a wiring part made of a conductive material, 5 is a terminal electrode part, and 6 is a protective film. Shown respectively. Further, the magnetoresistive element chip 2 made of a glass substrate is adhesively fixed to the lead island 7I, and the chip and the lead portion 7 are electrically connected by the wire 8. In this embodiment, the terminal electrode portion 5, the lead portion 7 and the like are molded and reinforced with a thermosetting transfer molding resin 9.

In this embodiment, as shown in FIGS. 1A and 1B, a boss for fixing a substrate is provided on the left side of the mold resin 9 of the mold type magnetoresistive element 1. The right side has a structure in which a cutout portion 9D is provided. As described above, in this embodiment, the resin portion having the boss and the notch and the magnetoresistive element chip are integrated, and the positional relationship between the sensor portion and the boss portion is uniquely determined. ing . Therefore, there is no problem that the relationship between the boss portion and the sensor position varies from element to element as in the conventional case. Also, by using the boss and the notch when fixing to the substrate etc., the use of the holder becomes unnecessary. The cutout can be used as a space for a fixing screw to the printed board or the like.

As a resin for molding the magnetoresistive element chip, a thermoplastic resin can be used as well as a thermosetting resin represented by an epoxy resin used in transfer molding. However, with respect to solder heat resistance, since the resin is thermoplastic, it is disadvantageous as compared with the thermosetting resin used in the transfer mold, but a resin with high heat resistance such as PPS or PBT is used. If there is no problem. Inorganic materials such as SiO and SiO2 are generally used as the material of the protective film 6 of the element chip, and they may be laminated, or a protective layer made of an organic material may be added if necessary. .

[0009]

Second Embodiment As a second embodiment of the present invention, a magnetoresistive element chip 201 having recesses at four corners of the chip as described in Japanese Patent Application Laid-Open No. 3-220472 is used in FIG. In addition, a resin-molded magnetoresistive element 101 of which the sensor surface is exposed is shown. 2A is a front view of the element, and FIG. 2B is a sectional view thereof. Also in this case, like the first embodiment, in the figure, 3S indicates a magnetic sensor part made of a ferromagnetic thin film, and the terminal electrode parts are formed in the recesses at the four corners of the chip. Similar to Example 1, the structure is such that they are electrically connected by wiring. The chip and the lead portion 7 are electrically connected by a wire 8. In the cross-sectional view of FIG. 2B, the wiring part, the terminal electrode, the protective film, etc. are omitted, but the sensor protective layer is provided on the outermost surface of the magnetoresistive element chip 201 not covered with the mold resin. I am writing. In this embodiment, the terminals and leads are molded and reinforced with a thermosetting mold resin 901. In this case, since the terminal electrode portions are formed in the recesses at the four corners, the surface of the mold resin and the surface of the magnetoresistive element chip 201 can be formed at substantially the same position.

In this embodiment, the mold resin is provided with bosses 901B on both sides thereof. As described above, also in this embodiment, since the resin portion having bosses on both sides and the magnetoresistive element chip are integrated, the positional relationship between the sensor portion and the boss portion is unique as in the first embodiment. Depends on. The boss can be used for fixing to a printed circuit board. In the case of this element, if the shape accuracy of the magnetic signal source is high, the positional relationship between the sensor portion of the element and the boss is uniquely determined, so that there is no need for gap adjustment that has been conventionally performed. Further, in the case of this element structure, since the molding resin does not protrude to the surface of the chip, it is advantageous when the gap with the magnetic signal source is narrow.

[0011]

[Effect of the device]

 As described above, according to the present invention, since the magnetoresistive element chip and the molding resin are integrated and the resin portion is provided with the positioning boss, the element is assembled to the holder. Is unnecessary. In addition, the element chip is molded and fixed in the correct position, so it is easy to obtain positional accuracy even when fixing it to a printed circuit board. Furthermore, it is not necessary to adjust the gap with the magnetic signal source, which helps save labor in assembly.

[Brief description of drawings]

FIG. 1A is a top view showing a resin mold type magnetoresistive element according to a first embodiment of the present invention, FIG. 1B is a plan view, and FIG.
Is a sectional view taken along the line AA of FIG.

2A and 2B are plan views and AA showing a resin-molded magnetoresistive element according to a second embodiment of the present invention.
Sectional view along the line.

3A and 3B are a plan view and a side view showing a conventional resin-molded magnetoresistive element.

FIG. 4A is a holder structure applicable to a conventional magnetoresistive element, and FIG. 4B is a front view when the element is attached to the holder.

[Explanation of symbols]

 1, 100, 101 ... Resin-molded magnetoresistive element 2 ... Magnetoresistive element chip made of glass substrate 3 ... Ferromagnetic thin film 4 ... Wiring section 5 ... Terminal electrode section 6 ... …… Protective film 7 ………… Lead part 8 ………… Wires 9,901,902 ・ ・ ・ Resin mold part 10 ………… Holder

Claims (2)

[Scope of utility model registration request] 1. A resin mold type magnetoresistive element having a boss or a cut in the resin molding portion. 2. The resin mold type magnetoresistive element according to claim 1, wherein the sensor portion is exposed.