JP2578440B2 - Work inspection classification method - Google Patents

Description

Description: Object of the Invention (Industrial application field) The present invention relates to a work inspection and classification method for inspecting and classifying a work such as a multilayer ceramic chip capacitor for an electronic component, and more particularly, to an accurate and quick method. The present invention relates to a work inspection and classification method capable of performing inspection and classification.

(Prior Art) Conventionally, a method as shown in FIG. 4 has been known as a work inspection classification method.

In this method, a work is supplied into a worktable of a turntable, and while the turntable is intermittently rotated, the capacitance and dielectric loss tangent of the work are inspected with a capacitance meter, and the withstand voltage of the work is measured with a withstand voltage meter. Inspection of workpieces with defective inspection values of capacitance, dielectric loss tangent and withstand voltage are discharged to the outside of the turntable, and the workpieces are classified into a plurality of ranks according to the inspection values of capacitance. . By the way, in general, when the withstand voltage of a work is inspected, the electrical characteristics of the work change.Therefore, the work classified into a predetermined rank on a turntable is then placed in a thermostat, for example.
Heated at 150 ° C for 1 hour, deaging (rejuvenation)
Is performed. Further, after the workpiece subjected to the aging is left for 4 to 24 hours, the capacitance and the dielectric loss tangent are again inspected by the capacitance meter for the final check, and the inspection values of the capacitance and the dielectric loss tangent are again inspected. Defective work is discharged.

As described above, a work having a poor electric property such as a capacitance is discharged from the turntable, and works classified according to the test value of the capacitance are bundled and shipped for each predetermined rank.

Next, the withstand voltage test will be described with reference to FIGS. 5, 6a and 6b.

In the withstand voltage test, as shown in FIG.
32 is inserted and a voltage is applied from the power supply 30. By this withstand voltage test, the work 32 generally changes its capacitance and dielectric loss tangent, and the changes in the capacitance and dielectric loss tangent are shown in FIGS. 6a and 6b, respectively. That is, the capacitance usually gradually decreases with the passage of time.
C drops rapidly. In addition, the dielectric loss tangent usually gradually decreases with the passage of time, but generally increases rapidly by ΔDF during a withstand voltage test.

As described above, the capacitance and the dielectric loss tangent change due to the withstand voltage test. In the case of a normal work, the change amounts fall within a predetermined range according to the type of the work. However, a work whose change amount largely deviates from this range is a defective product and cannot be used. For this reason, as described above, the work on which the withstand voltage test has been performed returns its structure to the initial state by deaging, and then the capacitance and dielectric loss tangent are detected again by the capacitance meter to discharge the defective work. .

(Problems to be Solved by the Invention) The conventional work inspection and classification method is performed according to the flow as shown in FIG. 4, but it takes about one hour for deaging in a constant temperature bath, and then requires 4 to 24 hours. Therefore, it takes a very long time in total.

The present invention has been made in view of such a point, and an object of the present invention is to provide a work inspection and classification method capable of performing inspection and classification quickly and accurately.

[Configuration of the invention]

(Means for Solving the Problems) According to the present invention, a work is supplied into a worktable of a turntable, and the turntable is intermittently rotated, and the capacitance and the dielectric loss tangent of the work are inspected by a capacitance meter. Inspects the withstand voltage of the work with a withstand voltage meter, discharges the work with bad test values of capacitance, dielectric loss tangent and withstand voltage, and classifies the work into multiple ranks according to the test of the capacitance. A work inspection classifying method, in which inspection of capacitance and dielectric loss tangent by a first capacitance meter, inspection of dielectric strength by a withstand voltage meter, and inspection of capacitance and dielectric loss tangent by a second capacitance meter are sequentially performed. Workpieces whose difference between the inspection value of the first capacitance meter of the capacitance and the inspection value of the second capacitance meter is a predetermined value or more, and the difference between the inspection value of the first capacitance meter of the dielectric loss tangent is a predetermined value or more To discharge the work It is characterized by doing.

(Operation) According to the present invention, while the turntable is rotating, it is possible to discharge a workpiece in which the variation in the capacitance and the dielectric loss tangent caused by the withstand voltage test largely deviates from predetermined values.

(Example) Hereinafter, an example of the present invention is described with reference to drawings.

1 to 3 are views showing an embodiment of a work inspection and classification method according to the present invention. 1 and 2, a work 3 is supplied to a turntable workstation 2 through a hopper 6, a ball feeder 7, a linear feeder 8 and a chute 9. Here, the workstation 2 is formed by penetrating the outer periphery of the disk-shaped turntable 1 in the axial direction of the turntable 1.

The turntable 1 in which the work 3 is supplied into the work station 2 rotates at a pitch of the work station 2 and stops at a high speed (about 1000 rpm).
Do with.

During the intermittent rotation of the turntable 1, the work 3 is inspected for capacitance and dielectric loss tangent by the first capacitance meter 10. Subsequently, the work 3 is charged by the charged voltage chargers 11 and 12, and the withstand voltage detector 1 is charged.
It is inspected in 3 and discharged in the withstand voltage discharger 14. The charged voltage chargers 11 and 12, the withstand voltage detector 13 and the withstand voltage discharger 14 constitute a charged voltage meter 5. Thereafter, the work 3 is again inspected for capacitance and dielectric loss tangent by the second capacitance meter 15.

Among the works 3 whose electric properties such as capacitance have been inspected in this way, the work 3 having poor electric properties is out-of-bin.
Discharged by the discharger 16 to the outside. That is, the work 3 discharged by the out-of-bin discharger 16 is
Since the electric characteristics exceed the inspection ranges of the first capacity meter 10, the withstand voltage meter 5 and the second capacity meter 15, the test cannot be performed.

Subsequently, the work 3 determined to have a withstand voltage failure by the withstand voltage meter 5 is
It is discharged to the outside by the withstand voltage defect discharger 17. The work 3 having the low capacitance or the high capacitance by the first capacitance meter 10 is supplied to the low capacitance discharger 18 or the high capacitance discharger 19.
Are respectively released to the outside. In addition, the first capacity meter
The work 3 determined as having a dielectric loss tangent failure at 10 is discharged outside by a dielectric loss tangent failure discharger 20.

Subsequently, the work 3 is classified into five ranks, that is, BIN1, BIN2, BIN3, BIN4, and BIN5, by the classifier 21 according to the inspection value of the capacitance in the first capacitance meter 10. The work 3 remaining firmly in the work station 2 is forcibly discharged to the outside by the mechanical discharger 22.

From the out-of-bin discharger 16, the second capacity meter 15
The work 3 in which the difference between the inspection value of the first capacity meter 10 and that of the first capacity meter 10 is equal to or larger than a predetermined value is also discharged, which will be described in detail below.

Generally, when a withstand voltage test is performed on the work 3, the capacitance rapidly decreases (FIG. 6a), and the dielectric loss tangent rapidly increases (FIG. 6b). Further, in the case of a normal work 3, the amount of change in the electrical characteristics due to the withstand voltage test is almost empirically determined according to the type of the work 3 such as a multilayer ceramic chip capacitor. Therefore, based on the empirically determined amount of change in the electrical characteristics, the work 3 whose amount of change is greatly different
Is discharged as defective.

For example, for a given work 3, the number of works corresponding to the change in capacitance after the withstand voltage test is distributed as shown in FIG. 3a, and the number of works corresponding to the change in the dielectric loss tangent after the withstand voltage test is It is assumed that the distribution is as shown in FIG. 3b. In this case, the empirical reference change amount of the capacitance change amount is -35.
Defined as PF, 0.5% of the empirical reference value for the change in dielectric loss tangent
Is determined. In FIGS. 3a and 3b, the workpiece 3 whose capacitance variation is outside the range of −50 PF to −20 PF is discharged as far away from the reference variation. Also, the work 3 whose variation of the dielectric loss tangent is out of the range of 0% to 1.0%,
Emitted as far from the reference change.

Therefore, the work 3 as shown in the table below is not discharged since the change amounts of the capacitance and the dielectric loss tangent enter the normal region.

The inspection and classification work of the work 3 described above is performed under the control of a control device (not shown) for each of the work 3.

Thus, according to the present embodiment, one of the turntables 1
Inspection and classification of the work 3 is performed during rotation, and a work in which the variation in the capacitance and the dielectric loss tangent by the withstand voltage inspection greatly deviates from the reference variation is also discharged. For this reason, the conventional aging step and the subsequent leaving step can be omitted, and the time and the inspection and classification work can be significantly reduced.

〔The invention's effect〕

According to the present invention, the work inspection and classification work can be reliably performed while the turntable is rotating, so that the conventional deaging step and subsequent leaving step can be eliminated, and the time can be significantly reduced. Reliable inspection and classification work can be performed.

[Brief description of the drawings]

FIG. 1 is a diagram showing a block diagram of a work inspection / classification method according to the present invention, FIG. 2 is a diagram showing an inspection / classification machine used in the work inspection / classification method according to the present invention, and FIG. FIG. 3b is a distribution diagram showing the change amount of the dielectric loss tangent by the withstand voltage inspection and the corresponding number of works, and FIG. 4 is a block diagram of a conventional work inspection classification method. FIG. 5, FIG. 5 is a diagram showing a case where a withstand voltage test is performed, FIG. 6a is a diagram showing a change in capacitance by a withstand voltage test, and FIG. 6b is a diagram showing a change in dielectric loss tangent by a withstand voltage test. . 1 ... turntable, 2 ... workstation, 3
…… Workpiece, 5 …… Voltage meter, 10 …… First capacity meter, 15…
… Second capacity meter, 16… out-of-bin ejector, 21… classifier.

Claims (1)

(57) [Claims] A work is supplied into a work station of a turntable, the turntable is rotated intermittently, a capacitance meter inspects a capacitance and a dielectric loss tangent of the work, and a withstand voltage meter measures a withstand voltage of the work. In the work inspection classification method, inspection is performed to discharge a work having defective test values of capacitance, dielectric loss tangent, and withstand voltage, and classify the work into a plurality of ranks according to the test value of capacitance. Inspection of the capacitance and the dielectric loss tangent by a capacitance meter, inspection of the charged voltage by a withstand voltage meter, and inspection of the capacitance and the dielectric loss tangent by a second capacitance meter are sequentially performed.
A work in which the difference between the inspection value of the capacitance meter and the inspection value of the second capacitance meter is a predetermined value or more, and the difference between the inspection value of the first capacitance meter and the inspection value of the second capacitance meter of the dielectric loss tangent is a predetermined value. A work inspection and classification method characterized by discharging the above work.