JPH06163651A - Semiconductor wafer inspection device - Google Patents

Abstract

PURPOSE:To enable the contact between the electrode of a semiconductor wafer and a probe needle to be performed with high reliability. CONSTITUTION:This is a semiconductor wafer inspection device equipped with a driving means, which brings a probe needle 3 into pressure-contact with an electrode by relatively shifting a wafer chuck 5 on which to place a semiconductor wafer 4 and a probe where a probe needle 3 capable of pressure-contact with each electrode of the semiconductor wafer 4 is attached to a probe card 2, and the wafer chuck 5 is provided with a pressure sensor 6 for detecting the contact pressure of the electrode of the probe needle 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for inspecting a semiconductor wafer, and more particularly to a technique effective when applied to a detecting device having a probe having a large number of probe needles extending radially from a substrate toward a central portion. Is.

[0002]

2. Description of the Related Art Conventionally, an LSI having no outer lead
When measuring the electrical characteristics of a semiconductor device such as, a probe having a large number of probe needles is used. The probe needle is, for example, a metal wire having a steel property, and its tip is pressed against the electrode of the LSI with an appropriate elastic force.

This probe needle is processed into a shape corresponding to the number and contact position of each electrode of the LSI, the non-contact end thereof is fixed to the lower surface of one substrate, and each of them has a measuring device. A lead wire (or cable) drawn from (or the inspection device) via a connector or the like is connected.

The probe having such a configuration is arranged on the upper surface of the semiconductor wafer set at a fixed position, the table of the semiconductor wafer is raised during the measurement, and each electrode of the LSI becomes a probe needle with an appropriate pressure. When the contact is reached, the table rise is stopped and the measurement is started.

By the way, in this type of probe,
If all of the probe needles are not in full contact with each electrode of the LSI, contact failure will occur and even if the LSI is a good product,
The measuring device determines that the product is defective.

Therefore, it is carried out to determine whether or not a pressure higher than a prescribed pressure is applied to the probe by contacting the electrode. Specifically, an edge sensor (having the same shape as the probe needle) is attached to two diagonals of the probe needle portion, and this output is transmitted to the measuring device through a cable,
The presence or absence of contact is determined by the change in conduction / non-conduction.

When measuring an LSI having different pin arrangements of the probe card, it is necessary to attach the probe card and replace the cassette frame (a jig for fixing the probe card and screwed). .

[0008]

According to the study by the present inventor, in the conventional technique for determining the contact state between the probe needle and the electrode on the sample side by the edge sensor, the sensor for contact is a jig ( There is a problem that the probe needle and the semiconductor wafer are damaged when the sensor does not operate because they are located on the probe card side, and the probe needle and the semiconductor wafer are damaged when the sensor does not operate.

Particularly, the pin arrangement of the probe card is LS
If the type of I is different, it will be necessary to replace the cassette frame with the probe card, and it will be difficult to maintain the high reliability of the edge sensor due to attachment of the edge sensor cable, defective cable connection, or forgetting connection. It has become.

Therefore, an object of the present invention is to provide a technique capable of highly reliable contact between an electrode portion of a semiconductor wafer and a probe needle.

The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.

[0012]

Among the inventions disclosed in the present application, a brief description will be given to the outline of typical ones.
It is as follows.

That is, a jig for mounting a semiconductor wafer and a probe portion in which probe needles capable of pressure contact with electrodes of the semiconductor wafer are attached to a probe card are relatively moved to press the probe needles against the electrodes. The jig is provided with a pressure sensor that detects a contact pressure between the probe needle and the electrode.

[0014]

According to the above-mentioned means, since the sensor for detecting the contact pressure between the probe needle and the electrode of the semiconductor wafer is provided on the jig (inspection device) side, the member which obstructs the replacement is not exposed. Therefore, it is possible to perform contact of the probe needle with high reliability without causing a sensor mounting failure, a connection failure, a connection forgetting, or the like unlike the related art.

[0015]

1 is a front view showing an embodiment of a semiconductor wafer inspection apparatus according to the present invention.

A probe card 2 is attached to a lower portion of a cassette frame 1 which serves as a base, and a plurality of probe needles 3 are radially projected from a central portion of the probe card 2 toward the center of the probe card 2 so as to obliquely project. Card 2
Is attached to. Below the probe card 2, a wafer chuck 5 for fixing the semiconductor wafer 4 is provided.
Is provided. Further, a pressure sensor 6 is attached to the mounting surface of the semiconductor wafer 4 of the wafer chuck 5.

The pressure sensor 6 preferably has a sensitivity capable of detecting a pressing force of 100 grams or less. For example, a strain gauge (semiconductor pressure sensor or the like) can be used. Here, the shape is a disk shape and they are arranged concentrically with respect to the wafer chuck 5 as shown in FIG.

In the configuration of FIG. 1, the tip of the probe needle 3 comes into contact with the electrode of the semiconductor wafer 4 by raising the wafer chuck 5 with the pressure sensor 6 placed thereon, and at the same time, a detection signal is sent to the pressure sensor 6. Occurs. When the rise of the wafer chuck 5 is stopped when the pressure detected by the pressure sensor 6 reaches the set value, the probe needle 3 reaches the optimum contact pressure.

In this case, it is desirable to gradually raise the wafer chuck 5 in order to prevent the contact pressure from becoming excessive, but this is not efficient. Therefore, the wafer chuck 5 is raised all at once until just before the probe needle 3 contacts the electrode of the semiconductor wafer 4, and then the wafer chuck 5 is gradually raised until the optimum contact pressure is reached.

FIG. 3 shows a control system for this purpose.

The wafer chuck 5 is moved in the Z-axis direction (vertical direction).
A height adjusting unit 8 is connected to a Z-axis driving unit 7 (comprising a motor as a driving source, a gear, etc.) that is driven to.
The height adjusting unit 8 drives the Z-axis driving unit 7 to move the wafer chuck 5 up and down. Further, the height adjusting unit 8 is connected to a control unit 9 for driving the height adjusting unit 8 based on the output signal of the pressure sensor 6.

Here, the distance from the upper surface of the probe card 2 to the lower surface of the probe needle 3 (that is, the jig thickness) is t, the distance between the lower surface of the probe needle 3 and the upper surface of the semiconductor wafer 4 is h, and the semiconductor wafer 4 is When the thickness is wt and (t + h + wt) is H, the lift amount h of the wafer chuck 5 at which the contact is started is expressed by the following equation.

H = Ht-wt The thickness of the probe card 2 differs depending on the type of the semiconductor wafer 4. Therefore, the thickness (substrate-probe needle tip) data t of the probe card 2 is added to each product data, and the controller 9 obtains the lift amount h of the wafer chuck 5 at which the contact is started from the above formula, and the lift amount h is calculated. Wafer chuck ascending speed "1"
And Then, the control of the controller 9 is determined so that the wafer chuck ascending speed after that (up to the limit value) is "2", and the Z-axis driver 7 is driven.

By this control method, it is possible to stabilize the needle contact. Further, in this embodiment, when the semiconductor wafer 4 is set on the wafer chuck 5 equipped with the pressure sensor 6, the pressure is reset by the weight of the semiconductor wafer 4.

As described above, according to the present invention, since the sensor is provided on the wafer chuck side (inspection device side), it is possible to eliminate the problems such as the attachment of the sensor cable, the defective cable connection, and the forgetful connection. This makes it possible to reduce the dependency on the jig and obtain a highly reliable contact.

Although the invention made by the present inventor has been specifically described based on the embodiments, the present invention is not limited to the embodiments and various modifications can be made without departing from the scope of the invention. Needless to say.

[0027]

The effects obtained by the typical ones of the inventions disclosed in the present application will be briefly described as follows.
It is as follows.

That is, a jig for mounting a semiconductor wafer and a probe portion having probe needles capable of pressure contact with each of the electrodes of the semiconductor wafer attached to a probe card are relatively moved to bring the probe needles into pressure contact with the electrodes. A semiconductor wafer inspecting apparatus including a driving means for causing the jig to be provided with a pressure sensor for detecting a contact pressure between the probe needle and the electrode, so that the probe needle can be contacted with high reliability. Will be possible.

Further, there is no influence on the contact state due to the deterioration of the elasticity of the probe needle due to the frequency of use, and the inspection can be performed while maintaining a stable state. Further, the edge sensor which has been conventionally required is no longer necessary.

[Brief description of drawings]

FIG. 1 is a front view showing an embodiment of a semiconductor wafer inspection apparatus according to the present invention.

FIG. 2 is a plan view showing details of the wafer chuck shown in FIG.

FIG. 3 is a block diagram showing a control system of the semiconductor wafer inspection apparatus according to the present invention.

[Explanation of symbols]

 1 Cassette Frame 2 Probe Card 3 Probe Needle 4 Semiconductor Wafer 5 Wafer Chuck 6 Pressure Sensor 7 Z-Axis Drive Section 8 Height Adjusting Section 9 Control Section

Claims (4)

[Claims] 1. A jig for mounting a semiconductor wafer and a probe unit having a probe needle attached to a probe card capable of being brought into pressure contact with each electrode of the semiconductor wafer are relatively moved to bring the probe needle into pressure contact with the electrode. A semiconductor wafer inspecting apparatus, comprising: a drive unit for driving the semiconductor wafer inspecting apparatus, wherein a pressure sensor for detecting a contact pressure between the probe needle and the electrode is provided on the jig. 2. The semiconductor wafer inspection apparatus according to claim 1, wherein the pressure sensor is provided on a mounting surface of a semiconductor wafer to be inspected. 3. The semiconductor wafer inspection according to claim 1, wherein the relative movement speed of the jig and the probe is increased at an initial stage, and is set to be a low speed after the point of contact between the probe needle and the electrode. apparatus. 4. The semiconductor wafer inspection apparatus according to claim 3, wherein the amount of the relative movement is changed according to the type of the semiconductor wafer to be inspected or the specifications of the jig to be used.