JPH03277980A - Magnetoresistance element measuring apparatus - Google Patents

Abstract

PURPOSE:To measure electric characteristics after the magnetic thin film material of an MR element is magnetized in a constant state even if the material is magnetized by the influence of an environmental magnetic field during manufacturing step and stocking by providing a magnetic field applying unit for magnetizing the element to the constant state. CONSTITUTION:A magnetoresistance (MR) element 21 to be measured is coupled to a lead frame 22 having a conveying hole 23. It is conveyed from a magazine 6 to a magazine 7 while repeating moving and stopping at each one pitch under a magnetic field applying unit 1 and a probe unit 3 by conveying mechanisms 9, 10. The unit 1 and the unit 3 are cooperated with the mechanisms 9, 10, and the magnet 2 of the unit 1 generates a magnetic field in a predetermined direction at the same speed as relative moving and stopping as the movement of the frame 22 constantly at the gap from it to magnetize the element 21 to a constant state. Then, the probe 4 of the unit 3 is moved down, and the electric characteristic of the element 21 is measured by a measuring unit 5 in contact with the outer leads 24 of the element 21. The unit 1 is retracted to a height causing no influence during measurement.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetoresistive element measuring device for measuring the electrical characteristics of a magnetoresistive element (hereinafter referred to as an MR element).

・[Prior art] Conventional magnetoresistive element measuring devices measure the electrical resistance value of a magnetic thin film pattern formed on the surface of an MR element, and determine whether it meets standards or not. .

[Problem to be solved by the invention]

In the conventional magnetoresistive element measuring device described above, the MR element receives a magnetic field generated from various manufacturing devices during the manufacturing process,
The electrical characteristics of a thin film pattern of an MR element formed of a magnetic material such as Ni, Fe, Co, or an alloy thereof are measured in a magnetized state. There is no problem if this magnetized state is always constant, but in reality, the magnetized state of the thin film pattern changes due to the environmental magnetic field while the MR element moves during assembly, manufacturing testing, and shipping inspection. do.

In addition, magnetic fields are generated for the MR element in various environments such as the magnetization state changing during delivery to the customer, and therefore the electrical characteristic values during manufacturing tests and shipping inspections and acceptance inspections at the customer site are subject to change. There was a drawback that there was a difference between the characteristic values measured by the method and the like.

[Means to solve the problem]

The magnetoresistive element measuring device of the present invention includes a magnetic field application unit that generates a magnetic field in a certain direction to magnetize the magnetoresistive element in a fixed state, and an electrical property that measures the electrical property by bringing a probe into contact with the magnetoresistive element. It is equipped with a measuring section.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a perspective view of an embodiment of the present invention, and FIG. 2 is a perspective view of an embodiment of the present invention.
It is a figure which shows the positional relationship with R element. In Figure 1,
A magnetic field applying part 1 is provided with a magnet 2 for generating a magnetic field in a certain direction, a probe part 3 is provided with a probe 4 so as to contact the external lead of the MR element, and is connected to the probe 4 to determine the electrical characteristics of the MR element. a measuring unit 5 for measuring MR elements, a magazine 6.7 for storing a lead frame in which a plurality of MR elements are connected at equal intervals, and a transport mechanism for moving the MR elements connected to the lead frame one pitch at a time along a guide rail 8. 9, 10 and magazine drive sections 11 and 12. In FIG. 2, the MR element 21 is connected to a lead frame 22 having a conveyance hole 23, and the MR element 21 is connected to a conveyor f#1.
9 and 10, each pitch is conveyed from the magazine 6 to the magazine 7 while repeatedly moving and stopping under the magnetic field applying section 1 and the probe section 3. The magnetic field application section 1 and the probe section 3 are linked with a transport mechanism 9.10, and when the lead frame 22 is moved, the gap between the MR element 21 and the magnet 2 of the magnetic field application section 1 is constant and the same. The probe 4 of the probe unit 3 descends and the MR
When contacting each of the four external leads 24 of the element 21 to start measurement, the magnetic field applying part 1 is retracted to a height where the magnetic field of the magnet 2 does not affect the MR element being measured by the probe part 3. It has become. The magnetic thin film material of the MR element, which has been magnetized in various states during the MR element manufacturing process in this way, is magnetized to a constant state immediately before measuring the electrical characteristics, and then the measurement is performed.

Figures 3 (a) and (b) are diagrams showing the results of investigating the measurement reproducibility of the electrical characteristics of the MR element, where the horizontal axis is the first measurement value and the vertical axis is the second measurement value. The correlation is shown as . FIG. 4(a) shows the case where the MR element measuring apparatus of the present invention is used, and FIG. 2(b) shows the case when the conventional MR element measuring apparatus is used. Comparing FIGS. 2A and 2B, it can be seen that the reproducibility of the measured values by the MR element measuring apparatus of the present invention is good. Note that in this embodiment, the magnetic field applying section 1
Although two magnets 2 are provided in this case, this is to ensure that the magnets are magnetized in a constant state, and at least one magnet 2 is sufficient.

〔Effect of the invention〕

As explained above, the present invention includes a magnetic field application unit that magnetizes the MR element in a constant state, thereby preventing the magnetic thin film material of the MR element from being magnetized by the influence of the environmental magnetic field during the manufacturing process and storage. Also, since the electrical characteristics can be measured after magnetizing to a certain state, the reproducibility of measuring the characteristics of the MR element can be improved and the quality can be stabilized.

[Brief explanation of drawings]

FIG. 1 is a perspective view of one embodiment of the present invention, FIG. 2 is a diagram showing the positional relationship with an MR element, and FIG. 3(a). (b) is a diagram showing the measurement reproducibility of the electrical characteristics of the MR element. DESCRIPTION OF SYMBOLS 1... Magnetic field application part, 2... Magnet, 3... Probe part, 4... Probe, 5... Measuring part, 6.7...
Magazine, 8... Guide rail, 9. lO...Transportation mechanism, 11°12...Magazine drive unit, 21...Magnetic resistance element (MR element), 22...Lead frame,
23... Conveyance hole, 24... External lead of MR element.

Claims (1)

[Claims] It is characterized by comprising: a magnetic field application section that generates a magnetic field in a certain direction to magnetize the magnetoresistive element in a fixed state; and an electrical property measuring section that measures the electrical properties by bringing a probe into contact with the magnetoresistive element. Magnetoresistive element measuring device.