JPS63266847A - Wafer probe - Google Patents

Abstract

PURPOSE:To accurately detect a probing state by electrically connecting one terminal of a probing detector to a probe stylus contacted partly at the same potential as a wafer and the other terminal to a stage for holding the wafer. CONSTITUTION:A terminal 16 connected to a detecting and probe stylus 13a and a terminal 17 connected to a stage 6 in a probing detector 15 are connected through normal closure switches 18, 19 to earth and power sides. The terminal 17 connected to the stage 6 is connected through a logic circuit 20 to a probing discriminator 21. The discriminator 21 detects the probing when the terminals 16, 17 are conducted therebetween, notifies it to a tester 14 to open the switches 18, 19, and transmits a command for starting a test to the tester 14. A communication between the tester 14 and the electronic circuit of a pellet 2 is executed through a probe card 10, a probe stylus 13 group and pads 4 group.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a wafer prober, and particularly to a probing detection technique for detecting contact of a probe needle with a wafer, and is used, for example, in the manufacturing process of semiconductor devices. This article concerns what is effective for use in wafer probers.

[Conventional technology]

2. Description of the Related Art In the manufacturing process of semiconductor devices, an electrical characteristic test using a wafer blower is carried out to inspect whether electronic circuits are properly formed on a wafer. This wafer prober electrically connects the electronic circuit of each pellet formed on the wafer to the tester of the wafer prober by bringing multiple probe needles into contact with the pads on the wafer. Characteristic tests are ensured by exchanging test signals between the two.

Therefore, in the wafer prober, it is necessary to detect the contact of the probe needle with the band.

As such a probing detection device, for example, a third
Something like the one shown in the figure is possible.

This is equipped with a normally closed switch mechanism a consisting of a movable contact piece and a fixed contact C.
is electrically connected to the probing detection circuit d, and the movable contact piece is connected to the scribe line 5 of the wafer 1.
It is configured as a probe needle that comes into contact with the and,
When the probe needle, which is a movable contact piece, comes into contact with the scribe line 5 of the wafer 1, it separates from the fixed contact C and opens the switch mechanism a. When the probing detection circuit d detects this, the probe needle The device is configured to detect contact between the needle and the wafer.

Examples of wafer prober technology that describe wafer prober technology include "Electronic Materials November 1983 Special Issue" published by Kogyo Research Association Co., Ltd., November 15, 1983, pages 195-198;
There is.

[Problem that the invention seeks to solve]

In such a probing detection device, when used for a semiconductor device such as a three-terminal regulator,
As the measurement time for electrical property tests becomes shorter, the vertical movement of the probe needle relative to the wafer becomes extremely rapid, making it impossible for the opening/closing operation of the movable contact piece to the fixed contact to follow the vertical movement of the probe needle. The inventor has clarified that there is a problem in which malfunctions occur, such as a period in which the movable contact piece remains ON to the fixed contact even though the probe needle is in contact with the wafer. It was done.

An object of the present invention is to provide a probing technique that can accurately detect probing conditions.

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

[Means for solving problems]

An overview of typical inventions disclosed in this application is as follows.

In other words, one terminal of the probing detection circuit that detects that the probe needle is in contact with the wafer is electrically connected to the probe needle that contacts a part that has the same potential as the wafer, and the other terminal is connected to the circuit that holds the wafer. It is electrically connected to the stage that is used.

[Effect]

According to the above-mentioned means, when the probe needle connected to the probing detection circuit comes into contact with the wafer, the probe needle, the wafer, the wafer is held, and the probe needle is moved through the stage and the other terminal connected to the stage. Since a closed circuit is formed, the probing detection circuit detects that the probe needle is in contact with the wafer.

At this time, the wafer and the probe needle itself in contact with the wafer constitute the detection switch of the probing detection circuit, so even if the relative vertical movement of the probe needle with respect to the wafer becomes high speed, the detection operation of the probing detection circuit will not continue. By following it, it will be executed properly.

〔Example〕

FIG. 1 is a schematic diagram showing a wafer prober which is an embodiment of the present invention, and FIG. 2 is an enlarged partial perspective view for explaining its operation.

In this embodiment, a plurality of pellets 2 are formed on a wafer 1 as an object to be inspected, and each pellet 2 is an object to be tested for electrical characteristics. A necessary electronic circuit (not shown) is built into the inside of the pellet 2, and a plurality of pads 4 connected to the electronic circuit are formed on the main surface 3 of the pellet 2. In addition, each pellet 2 has a wafer 1
It is divided by a scribe line 5 formed on the main surface 3 of.

This wafer prober is equipped with a stage 6 on which inspection and probing are performed, and the stage 6 is configured to suck and hold the wafer 1 and move it regularly in the XY direction, as well as in the θ direction and the vertical direction. It is configured so that its position can be adjusted. stage 6
A probe card 10 is disposed directly above the board 7 and supported by the board 7 in a detachable manner. The probe card 1o includes a main body 11 formed of a substantially rectangular thin plate, and a circular window hole 12 is provided in the main body 11 in a substantially central portion thereof so as to allow viewing downward.

A plurality of probe needles 13 are protruded from the lower surface of the main body 11 with one end of each being mechanically supported.
are electrically connected to the tester 14 of the wafer prober through the main body 11, respectively.

At least one probe needle 13a of the probe needles 13 is arranged so as to be able to contact a pad 4a (hereinafter referred to as a ground pad) connected to a ground terminal of an electronic circuit among the four groups of bands in the pellet 2. has been done.

In this embodiment, this wafer blobber includes a probing detection circuit 15 for detecting that the probe needle is brought into contact with the band. In this circuit 15, one terminal 16 that substantially constitutes a pair of detectors is a probe needle (hereinafter referred to as a detection probe needle) 13a arranged so as to be able to contact the ground pad 4a.
and the tester 14, and
The other terminal 17 is electrically connected to the stage 6. In the probing detection circuit 15, the terminal 16 connected to the detection probe needle 13a and the stage 6
The terminals 17 connected to are connected to the earth side and to the power supply side via normally closed switches 18, 19, respectively. In addition, the terminal 17 connected to the stage 6
is connected to a probing determination unit 21 via a logic circuit 20, and this determination unit 21 detects that probing has been performed when the terminals 16 and 17 are energized, and notifies this to the tester 14, Both switches 18.19
is configured to open.

Next, the action will be explained.

When the wafer 1 to be inspected is suctioned and held on the stage 6, first, the stage 6 performs alignment and needle pressure matching between the 4 groups of pads of the wafer I and the 13 groups of probe needles.
This is carried out by moving the probe card 1o relative to the probe card 1o.

Thereafter, when the stage 6 is raised to probe a predetermined pellet 2, each probe needle 13 comes into contact with each pad 4 of the pellet 2, respectively.

At this time, when the detection probe needle 13a comes into contact with the ground pad 4a, the power supply-power side switch 19→terminal 17→stage 6→wafer 1→bellet 2−ground pad 4a−detection probe needle 13a one terminal 16→ Earth side switch 18 → In order to conduct electricity via earth,
The determination unit 21 of the probing detection circuit 15 determines that probing has been performed. Then, the determination unit 21 opens the switches 18 and 19 and sends a command to the tester 14 to start the test.

The tester 14 performs a predetermined procedure (for example, slightly raises the stage 6 to ensure reliable contact).

), then start the test. That is, tester 1
4 and the electronic circuit of the pellet 2 is performed through a probe card 10, a group of probe needles 13, and a group of pads 4. At this time, since the probing detection circuit 15 is electrically disconnected by the switches 18 and 19, the detection probe needle 13a functions as a grounding probe needle without any problem.

When the predetermined test is completed, the stage 6 is lowered, so that the group of probe needles 13 is separated from the group of pads 4 of the pellet 2 for which the test has been completed, and the switches 18 and 19 are
is closed. Incidentally, in order to ensure followability, it is desirable to use non-contact type switches 18 and 19.

Thereafter, the stage 6 is moved regularly in the X or Y direction, and the pellet 2 to be inspected next time is faced to a predetermined position. Thereafter, by repeating the above operations at a high speed, the pellets 2 of the entire wafer 1 are sequentially inspected.

According to the embodiment described above, the following effects can be obtained.

(1) By electrically connecting one terminal of the probing detection circuit to a probe needle that contacts a part that has the same potential as the wafer, and the other terminal to a stage that holds the wafer, the probe needle is connected to the wafer. Since probing can be detected through the probe needle, wafer, and stage when they come into contact, it is possible to accurately detect probing by following the relative vertical movement between the probe needle group and the wafer.

(2) In general, a wafer prober is configured to automatically stop if no probing is detected, and if there is an error movement in probing, automatic stopping often occurs, but as described in (1) above, If probing detection is consistently performed properly, auto-stops will be reduced.
The operating efficiency and workability of the wafer prober can be improved.

(3) By using one of the probe needles for probing detection, the needle dedicated to probing detection can be omitted, and damage caused by the needle can be reduced accordingly.

(4) If the detection probe needle of the probing detection circuit is configured to touch the scribe line, the
The output probe needle may slide on the scribe line and damage the circuit section of the pellet, but by configuring the detection probe needle to contact the ground pad of the pellet, the circuit section due to the needle sliding can be prevented. Damage can be prevented.

Although the invention made by the present inventor has been specifically explained above based on Examples, it goes without saying that the present invention is not limited to the Examples and can be modified in various ways without departing from the gist thereof. Nor.

For example, a probe needle that also serves as a probe needle for probing detection is not limited to a probe needle that also serves as a probe needle that contacts a ground pad.
Something that has the same potential as the wafer, such as a probe needle that contacts the power supply pad, may also be used. Further, the probe needle for probing detection may be configured to contact a portion having the same potential as the wafer, such as a scribe line.

The specific structure of the probing detection circuit is not limited to the one in the above embodiment, but may also include, for example, a circuit in which both terminals of a power source with a light bulb connected to a probe needle and a stage, respectively. Good too.

〔Effect of the invention〕

A brief explanation of the effects obtained by typical inventions disclosed in this application is as follows.

By electrically connecting one terminal of the probing detection circuit to the probe needle that contacts a part that has the same potential as the wafer, and the other terminal to the stage number that holds the wafer, the probe needle comes into contact with the wafer. Since probing can sometimes be detected through the probe needle, wafer, and stage, probing can be accurately detected by following the relative vertical movement of the probe needle group and the wafer.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing a wafer prober which is an embodiment of the present invention, and FIG. 2 is an enlarged partial perspective view for explaining its operation. FIG. 3 is a schematic diagram showing a generally considered probing detection device. 1... Wafer, 2... Pellet, 3... Principal surface, 4
... Band, 4a... Grounding pad (portion that has the same potential as the wafer), 5... Scribe line, 6.
... Stage, 7 ... Board, 10 ... Probe card, 11 ... Main body, 12 ... Window hole, 13 ... Probe needle, 13a ... Detection probe needle (same potential as the wafer) (probe needle that touches the part), 14...
Tester, 15... Probing detection circuit, 16.17
...Terminal, 18.19...Switch, 20...Logic circuit, 21...Judging section.

Claims (1)

[Claims] 1. One terminal of a probing detection circuit that detects that the probe needle is in contact with the wafer is electrically connected to the probe needle that comes into contact with a part that has the same potential as the wafer; A wafer prober, the other terminal of which is electrically connected to a stage that holds a wafer. 2. The probe needle connected to the probing detection circuit is
The wafer prober according to claim 1, wherein the wafer prober is configured to contact a pad for establishing a ground potential on the wafer. 3. The probe needle connected to the probing detection circuit is
The wafer prober according to claim 1, wherein the wafer prober is configured to come into contact with a scribe line of the wafer. 4. The wafer prober according to claim 1, wherein the probing detection circuit is configured to be electrically disconnected from the wafer after probing detection.