JPH03290940A - Wafer table of probing machine - Google Patents

Abstract

PURPOSE:To bring the probes of a probe card into contact with the electrodes of IC's on a wafer accurately by a method wherein the inclination of a wafer table can be corrected in accordance with the inclination of the probe card. CONSTITUTION:After a probe card 28 is connected to a probe socket, a wafer chuck 10 is moved to a position B and receives a wafer 22 which is an object to be tested and moved to a position C and then to a position D. The wafer is positioned at the position C. Further, at the position D, the probes 28A of the probe card 28 are aligned with the electrodes of the wafer and the various electrical characteristics of the wafer are tested while the probes 28A are brought into contact with the respective electrodes of the wafer. If the probe card 28 is inclined and the contact between the probe 28A end the electrode is not satisfactory at that time, some of the vertical rods 64 of an inclination correcting mechanism 52 are moved vertically to align the mounting surface of a wafer table 12 with the inclined surface of the probe card 28 to bring the probe 28A into contact with the electrode securely.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a probing machine for inspecting the electrical characteristics of ICs on a wafer, and particularly to a probing machine equipped with a probe card that is replaced depending on the type of wafer. Regarding this.

[Conventional technology]

Some probing machines use a probe card that has a stylus on an insulating substrate. Several types of probe cards are prepared in advance, and the probe card that matches the wafer to be inspected is attached to the measuring section.

The probe card has a stylus that contacts the bonding pad of an IC on the wafer and sends a measurement signal to the IC tester. Therefore, the stylus of the probe card must be in accurate contact with the bonding pad of the IC on the wafer with a predetermined contact pressure during measurement.

[Problem to be solved by the invention]

On the other hand, as the performance of ICs increases, the diameter of wafers also increases.
Correspondingly, the dimensions of the probe card also increase. When the dimensions of the probe card become large, even if the probe card is slightly tilted, the amount of tilt becomes large, and sufficient contact pressure cannot be obtained with the stylus, which may result in poor measurement. For this reason, in conventional probing machines, the inclination of the probe card is corrected by operating the mounting part of the probe card.
There was a drawback that it took time to adjust.

The present invention was made in view of the above circumstances, and an object of the present invention is to propose a probing machine that can easily and reliably establish contact between the stylus of the probe card and the bonding pad on the Ueno IC. .

[Means to solve problems]

In order to achieve the above object, the present invention provides a wafer mounting table that is movable in the X direction, Y direction, and two directions (up and down directions), and on which a wafer is placed and transferred to a measuring section, and a In a probing machine having a probe card which is provided in advance and has a stylus that comes into contact with the bonding pad of the IC on the probing machine, which is attached to the probing machine body and is connected to the IC tester, the above-mentioned mounting stand is , the tilt can be corrected according to the amount of tilt of the probe card.

[Function] In the present invention, since the wafer mounting table has an inclination correction function, it is possible to easily cope with the inclination of the probe card by correcting the inclination of the wafer mounting table. ＼Contact with the bonding pads of the upper IC is ensured.

〔Example〕

Hereinafter, preferred embodiments of the probing machine according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a plan view of a probing machine to which the present invention is applied. As shown in FIG. 1, the probing machine is equipped with a wafer chuck 10 that suctions and fixes the wafer, a wafer mounting table 12, a pre-alignment device 14 that positions the wafer, and a probe card 28. It is composed of a measuring section 16 and the like that performs characteristic inspection.

The bags 22 stored in the cassette 18 shown in FIG.
positioned in position. The positioned wafer 22 is transported from position A to position B by the transport arm 24. Further, the wafer 22 moved to the B position is vacuum-adsorbed by the wafer chuck 10 and transferred to the measuring section 16 by the wafer mounting table 12.

FIGS. 2A and 2B show the structure of the wafer mounting table 12. FIG. The wafer mounting table 12 includes, from the bottom, an XY stage 50, a tilt correction mechanism 52, a Z stage 54, and a wafer chuck 10 formed on the top surface of the Z stage. The X-Y stage 50 is moved in the X-Y direction by a known structure such as a screw feed mechanism, and the Z stage 54 is moved in the vertical direction by a known structure such as a cam mechanism.

A hemisphere 58 is formed at the center of the lower surface of the support plate 56 of the tilt correction mechanism, and this hemisphere 58 is supported by a spherical seat 62 of a post 60 set on the Z-Y stage 50. Therefore, the support plate 56 is a hemispherical portion. It can be tilted in any direction around 58. Vertical bars 64, 64, 64 are provided around the post 60, and this vertical bar 64 is connected to a vertical feed mechanism 66 such as a motor.
Driven by. Note that 68.68.68 is a spring.

The operation of the probing machine according to the present invention configured as described above will be explained.

After the probe card 28 is connected to the probe socket, the wafer chuck lO moves to the B position, receives the wafer 22 as the product to be inspected, and moves to the C position, as shown in FIG.
Move in order of D position. At position C, the wafer is positioned, and at position D, the electrode of the wafer and the stylus 28A are aligned using a microscope (not shown), and the stylus 28A is not brought into contact with each electrode of the wafer. Testing of electrical characteristics is carried out. At this time probe card 2
8 is tilted and the probe 28A is not making sufficient contact, move one of the vertical bars 64 of the tilting mechanism 52 up and down to align the mounting surface of the wafer mounting table 12 with the inclined surface of the probe card 28, and then touch the probe card 28. Make sure the needle 28A makes contact.

To install the probe card into the probe socket,
Although manual operation or automatic device may be used, the present invention is particularly effective for manual operation.

Further, the probe card 28 may be transported and connected to the measuring section 16 using the wafer chuck 10 that transports the wafer. Thereby, there is no need to separately provide a means for transporting the probe card, and the apparatus can be simplified.

〔Effect of the invention〕

As explained above, according to the probing machine according to the present invention, since the wafer mounting table is provided with the tilt correction mechanism, the wafer mounting surface can be tilted according to the amount of inclination of the probe card, and the stylus of the probe card can be tilted. exactly on the wafer
It can be brought into contact with C.

[Brief explanation of drawings]

FIG. 1 is a plan view of a probing machine according to the present invention, and FIGS. 2(A) and 2(B) are explanatory views showing essential parts of the present invention. DESCRIPTION OF SYMBOLS 10... Wafer chuck, 12... Wafer mounting table, 16... Measurement part, 22... Wafer 28... Probe card, 52... Tilt correction mechanism,
58... Hemispherical part, 62... Spherical seat, 64... Upper and lower bars.

Claims (1)

[Claims] A wafer mounting table that is movable in the X direction, Y direction, and Z direction (up and down direction) and that places the wafer on it and transfers it to the measurement unit, and a wafer mounting table that is prepared in advance according to the type of wafer and that makes contact with the bonding pad of the IC on the wafer. In a probing machine that has a probe card that has a stylus that is attached to the probing machine main body and is connected to an IC tester, the mounting table is capable of inclination correction according to the amount of inclination of the probe card. A wafer mounting stand for a probing machine, which is characterized by: