JP5190943B2 - 2 probe Kelvin probe - Google Patents

Description

  The present invention relates to a two-probe Kelvin probe. More specifically, the present invention relates to a two-probe Kelvin probe that can inspect circuit electrodes with random arrangement of measured electrodes by the Kelvin method.

  In recent years, electronic circuits have become finer pitches, which is said to be the limit compared to conventional electronic circuits. On the other hand, higher reliability and reproducibility are required for circuit measurement accompanying improved electronic device performance. ing.

  Conventionally, for circuit inspection, only one contact probe was contacted to the circuit electrode and conduction could be obtained. However, high reliability has been required in recent years, and the Kelvin method has been proposed as a method to meet this demand. ing. This Kelvin method measurement theory for electronic circuit inspection has entered the stage of practical use, and its demand has been increasing in recent years.

  Conventionally, when the electrodes to be measured are arranged in parallel, measurement can be performed by the Kelvin method using a four-probe Kelvin probe. However, when the arrangement of the electrodes to be measured is random, measurement can be performed by the Kelvin method. The probe is not known at all.

As a two-probe Kelvin probe, the present applicant applies a two-probe to a two-probe Kelvin probe (see Patent Document 1) used for a flying measuring machine and a solder ball on the back side of a semiconductor, and inspects without trouble. Proposed a two-probe Kelvin probe (see Patent Document 2) and applied for a patent earlier. However, these cannot be used for circuit inspection when the arrangement of the electrodes to be measured is random.
Therefore, conventionally, when the arrangement of the electrodes to be measured is random, the measurement is not performed by the Kelvin method but by a method in which the probes are brought into contact with the circuit electrodes one by one. For this reason, there is a drawback that the inspection efficiency and the reliability of the inspection are poor.
JP 2005-62100 A JP-A-2005-283359

  An object of the present invention is to provide a two-probe Kelvin probe that can be used for circuit inspection when the arrangement of electrodes to be measured is random.

  In order to achieve the above object, as a result of intensive studies, the present inventor has developed a two-probe Kelvin probe that can be used for circuit inspection when the arrangement of the electrodes to be measured is random. Considering the need for a corresponding vertical movement function and a movable contact function that absorbs irregularities corresponding to the minute irregularities of the object to be measured, and the necessity of making the probe itself extremely fine, From the conventional circular shape, it is possible to make the probe itself a very thin shape with a cross-sectionally long shape, and to allow the two probes to move up and down independently and to move up and down together. And found that a two-probe Kelvin probe can be obtained, and the present invention has been achieved.

That is, according to the present invention, two probes having a horizontally long spring property and coated with an insulating film (one for voltage (V) and the other for current (A)) are elastically independent of each other. The probe storage sleeve is fitted to the inspection plate mounting sleeve so that it can be bent, and the coil spring is removed between the tip of the probe storage sleeve and the front end of the inspection plate mounting sleeve. The two probe rear portions are fixed to the probe storage sleeve.

It is preferable that a stopper and a spring pressure adjusting cylinder are fitted to the protruding portion of the probe storage sleeve from the rear end of the inspection plate mounting sleeve. It is preferable that a hook is formed at the tip of the probe storage sleeve and the tip of the sleeve for mounting the inspection plate, and the coil spring is fitted between the two hooks.

It is preferable that the two probes having a horizontally long cross section have a semicircular diameter or a rectangular cross section, and that the probe storage sleeve and the inspection plate mounting sleeve have a circular cross section (Claim 4). In order to make it easy to form a circular hole in the probe mounting plate and to bend the two probes independently, in the case of a very thin wire body, it is necessary to make it horizontally long. It is because the tolerance of is not obtained. In particular, the horizontally long shape is preferably a semicircular cross section or a rectangle, and the semicircular cross section is most preferable because a predetermined tolerance can be obtained even if it is formed small.

It is preferable to adjust the spring pressure so that the probe housing sleeve moves against the spring force after the two probes hit the minute unevenness of the object to be measured and bend independently. Item 5).

It is preferable that an outer diameter of the inspection plate mounting sleeve is 0.3 to 0.8 mm, and an outer diameter of the probe storage sleeve is 0.2 to 0.7 mm. It is preferable that the inner diameter of the storage sleeve is 0.2 to 0.6 mm, and the long sides or the straight portions of the two probes are 0.1 to 0.5 mm.

The Kelvin probe is used for inspecting a circuit electrode in which the arrangement of electrodes to be measured is random (claim 8).

  As described above, according to the present invention, it is possible to provide for the first time a two-probe Kelvin probe that can be used for circuit inspection when the arrangement of measured electrodes is random. Since it has improved the inspection efficiency and the reliability of inspection, it contributes greatly to the electronics circuit measurement department.

  FIG. 1 shows an embodiment of the present invention. In a probe housing sleeve 1 having a circular cross section, two probes 2 and 2 'having a horizontally long cross section and coated with an insulating film are independent of each other. Thus, it is inserted so as to have a fine gap so that it can be bent. A conventional probe has a circular shape, and a probe having a horizontally long cross section is not known. By forming the cross section horizontally long in this way, durability against a large number of elastic deformations can be imparted even if the shape is extremely fine.

As described above, since the gap is provided between the probes 2 and 2 ', the probes 2 and 2' are bent independently to absorb the irregularities on the surface of the object to be measured, thereby reliably realizing the role of the two probes. . The size of the gap is preferably such that the probes 2 and 2 'are separated by about 0.03 to 0.06 mm.

The horizontally long shape is preferably a rectangular cross section as shown in FIG. 2A or a semicircular cross section as shown in FIG. 2B, and the semicircular cross section is particularly fine and highly durable. It is preferable because it can be imparted.
As a material for the probes 2 and 2 ', an optimum material may be selected from metals such as steel, beryllium, phosphor bronze, stainless steel, and molybdenum according to the application. The type of insulating film that covers the probes 2 and 2 'is not particularly limited, but in the above embodiment, polyimide resin is used.

At the rear end of the probe storage sleeve 1, two probes 2 and 2 ′ are pressed or bonded and fixed. In the figure, reference numeral 3 denotes a pressure contact or adhesive fixing portion. Thus, since the two probes 2 and 2 ′ have spring properties and the rear side is fixed to the probe storage sleeve 1, the two probes 2 and 2 ′ are elastically bent between the tip and the fixing portion.

An inspection plate mounting sleeve 4 is fitted on the probe storage sleeve 1, and the inspection plate mounting sleeve 4 is fitted on the probe mounting plate 5. A coil spring 8 is externally fitted between a spring drop prevention rod 6 formed at the tip of the probe storage sleeve 1 and a spring drop prevention rod 7 at the tip of the inspection plate mounting sleeve 4 to inspect the probe storage sleeve 1. A stopper and a spring pressure adjusting cylinder 9 are fitted and fixed to the protruding portion from the rear end of the plate mounting sleeve 4 and the rear portions of the two probes 2 and 2 'are connected to the inspection plate mounting sleeve. 4 is fixed. The rear ends A and B of the two probes 2 and 2 'are lead wire connecting portions.

The sleeve 1 and the sleeve 4 are positioned by the cylindrical body 9, and the spring pressure of the coil spring 8 can be set to a predetermined value.
The material of the probe storage sleeve 1, the inspection plate mounting sleeve 4 and the cylindrical body 9 may be selected from metals such as steel, beryllium, phosphor bronze, stainless steel, molybdenum and the like, similar to the materials of the probes 2 and 2 '. .

  In the probe of the present invention, a round hole matched with a pattern is randomly drilled in a measurement resin plate (probe mounting plate) 5 by a drill or other method, and the probe is generally mounted in this hole. is there.

The outer diameter of the inspection plate mounting sleeve 4 is preferably 0.3 to 0.8 mm, and the outer diameter of the probe storage sleeve 1 is preferably 0.2 to 0.7 mm, and should be smaller than this. Is technically difficult, and beyond this, it cannot handle the intended test.
In order to obtain such a probe, the inner diameter of the probe storage sleeve 1 is 0.2 to 0.6 mm, and the long sides or the straight portions of the two probes are 0.1 to 0.5 mm. Good to do.

Next, a method for manufacturing the probe of the present invention will be described.
Two probes 2 and 2 ′ having a semicircular or rectangular cross section are mounted in the sleeve 1 so as to have a slight gap, and are pressed or adhered and fixed at the rear end of the sleeve 1. ′ (Probes A and B in FIG. 2), as shown in FIG. 3, can be elastically bent independently of the object to be measured 10, and reliably absorbs fine irregularities on the surface of the object to be measured. Realize the role of two probes.

After the probes 2 and 2 ′ are mounted, a coil spring 8 is externally fitted between the spring drop prevention rod 6 of the sleeve 1 and the spring drop prevention rod 7 at the tip of the sleeve 4 for attaching the inspection plate. The coil spring 8 has a purpose of sliding between the sleeve 1 and the sleeve 4 and a purpose of maintaining a torque necessary for the contact.
Then, a stopper ring 9 for adjusting the spring pressure between the sleeve 1 and the sleeve 4 is fixed to the probe 1 by pressure contact or adhesion, and the functionality of the entire probe is completed.
The spring pressure of the coil spring 8 is such that the probe housing sleeve resists the spring force of the coil spring 8 after the two probes 2 and 2 ′ hit the minute unevenness of the object to be measured and bent independently. Adjust to move.

  The projecting dimension of the probe tip from the sleeve 1 is set to an appropriate projecting dimension in accordance with the rigidity of the probe according to the outer diameter dimension of the sleeve 1. For example, when the probe (sleeve 4) has an outer diameter of 0.45 mm, the spring torque of the sleeve 1 is set to an initial load of about 5 to 8 g, and when the tip portion is compressed by 0.3 mm, the needle pressure (torque) is 10 to 16 g. Then, the projecting dimension of the probe from the sleeve 1 at that time was about 1 mm to 1.2 mm, and the role of the contact with the object to be measured was sufficiently achieved. If the torque (needle pressure) is requested by the user, it can be changed by changing the torque of the coil spring attached to the outer diameter of the sleeve.

It is a sectional side view which shows one Example of this invention. It is a front view which shows the shape of the probe of this invention of FIG. It is a sectional side view which shows the use condition of the probe of this invention.

Explanation of symbols

1 ·········································· Probe 3 ········································· Prevention rod 7 ········· Spring removal prevention rod 8 ······· Coil spring 9 ·································

Claims (8)

Two probes having a horizontally long cross section and coated with an insulating film are inserted into the probe storage sleeve so that they can be elastically bent independently of each other, and the probe storage sleeve is used as a sleeve for mounting an inspection plate. And a coil spring is externally fitted between the tip of the probe storage sleeve and the tip of the inspection plate mounting sleeve, and the two probe rear portions are fixed to the probe storage sleeve. Two-probe Kelvin probe. 2. The probe according to claim 1, wherein a stopper and a spring pressure adjusting cylinder of the coil spring are fitted and mounted on a protruding portion of the probe storage sleeve from the rear end of the inspection plate mounting sleeve. The probe according to claim 1 or 2, wherein a flange is formed at a distal end portion of the probe storage sleeve and a sleeve distal end for mounting an inspection plate, and the coil spring is externally fitted between both the flanges. The two probes having a cross-sectionally long spring property have a semicircular diameter or a rectangular cross section, and the probe storage sleeve and the inspection plate mounting sleeve have a circular cross section. probe. The spring pressure is adjusted so that the probe housing sleeve moves against the spring force of the coil spring after the two probes hit the minute irregularities of the object to be measured and bent independently. The probe according to any one of claims 1 to 4. 6. The outer diameter of the inspection plate mounting sleeve is 0.3 to 0.8 mm, and the outer diameter of the probe storage sleeve is 0.2 to 0.7 mm. 6. probe. The inner diameter of the probe storage sleeve is 0.2 to 0.6 mm, and the length of the long side or the straight portion of the two probes is 0.1 to 0.5 mm. The probe as described. The said Kelvin probe is a probe in any one of Claims 1-7 which test | inspects the circuit electrode whose arrangement | positioning of a to-be-measured electrode is random.

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