JPH0541424A - Probe apparatus - Google Patents

Abstract

PURPOSE:To miniaturize an apparatus, eliminate the influence of heat generation from a test head, and reduce the adhesion of dust to an object to be tested. CONSTITUTION:A chuck 5 retains a wafer 2 in the state that an electrode pad is faced downward. Under the chuck 5, a probe card 7 is arranged in the state that contact pins 6 are faced upward. A test head 11 is arranged under the probe card 7. Cooled air A is supplied from feeding nozzles 15. The air A passes the wafer 2 and the probe card 7, and flows down in the test head 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a probe device for measuring the electrical characteristics of an object to be inspected by bringing a stylus of a probe card into contact with an electrode pad of the object to be inspected such as a semiconductor wafer.

[0002]

2. Description of the Related Art A probe device shown in FIG. 5 is known as a probe device for inspecting the electrical characteristics of each IC chip formed in large numbers on a semiconductor wafer (hereinafter simply referred to as a wafer). The wafer a is placed on a wafer chuck b which holds the wafer a by suction, and a probe card c is installed above the wafer a. On the lower surface of the probe card c, a stylus d that contacts the electrode pad of the IC chip on the wafer a is implanted. The test head e also has a hinge f as shown.
The probe card c is supported above the probe card c so that it can be erected. Then, when inspecting the electrical characteristics of the wafer a, the test head e is moved to the upper portion of the probe card c, and the test head e and the probe card c are electrically connected via a pin or the like.

[0003]

By the way, in this type of probe device, the test head e has a multi-pin structure in accordance with the miniaturization and complexity of the IC chip, which is large and heavy. .. For this reason, installing the test head e on the upper portion of the probe device as in the prior art requires the support structure to be robust, which inevitably increases the size and weight of the probe device.

Further, since the wafer a held upward is inspected by contacting it with the stylus d of the probe card c above it, the oxide film scraps scraped off from the surface of the electrode pad by the stylus d. There is a problem that fine dust and the like that enter from the outside of the probe device are easily attached to the wafer a, and the quality of the wafer a is deteriorated.

In order to solve the above problems, the inventors of the present invention hold the wafer downward, provide the probe card with the stylus facing upward, and provide the test head under the probe card. We have created an inverted probe device that has a vertical relationship reversed from that of the probe device.

However, when the new inverted probe device is adopted, the following new problems occur. That is, as described above, the test head has a multi-pin structure, and the electronics in the test head, mainly the driver sensor card of the tester and the pin electronics, generate a lot of heat. Due to the heat generated from the test head, particularly convection, the probe card located above the test head may become hot. Also, in general,
It is desirable that the probe card, wafer, etc. be kept at a constant temperature.

The present invention has been made in view of the above circumstances, and takes measures against heat such as downsizing of an apparatus, prevention of adhesion of dust to an object to be inspected, and removal of influence of heat generated from a test head. It is an object of the present invention to provide a probe device.

[0008]

In order to achieve the above object, the present invention provides a tester in which a probe needle of a probe card is brought into contact with an electrode pad of an object to be inspected and which is connected to a probe cart through a test head. A probe device for measuring the electrical characteristics of an object to be inspected by providing the stylus of the probe card above the test head,
While holding the inspected object above the probe card by a holding means so that its electrode pad faces downward,
The downflow of the cooling gas flowing down the test object, the probe card and the test head is formed.

In the present invention, as the holding means, for example, a mounting table capable of vacuum suction may be used,
It is desirable to have a structure that can move in the X, Y, and Z directions. Examples of the cooling gas include clean air cooled by an air conditioner and low temperature N2 gas. Further, in order to form the downflow of the cooling gas, for example, an outlet for the cooling gas may be provided on the holding means side, and a suction / exhaust fan may be provided on the lower side of the test head.

[0010]

[Function] When the probe of the probe card is brought into contact with the electrode pad of the device under test to measure the electrical characteristics of the device under test,
The test head generates heat, and the probe card and the like above the test head are exposed to thermal effects mainly due to thermal convection.
However, in the present invention, since the downflow of the cooling gas flowing down the test head from the device under test through the probe card is formed, the problem due to heat generation of the test head can be eliminated. Further, this downflow also suppresses intrusion of dust or the like from the outside and adheres to the wafer or the like, and the probe device is maintained in a clean state. Furthermore, by controlling the flow rate and the temperature of the downflow of the cooling gas, it becomes possible to keep the temperature of the object to be inspected, such as the wafer, constant.

[0011]

Embodiments of the present invention will be described below in detail with reference to the drawings. In FIG. 1 and FIG. 2 which is a plan view thereof,
Reference numeral 1 denotes an apparatus main body casing of the probe device, and the probe device has an inspection unit 3 for inspecting electrical characteristics of a large number of IC chips formed on a wafer 2 as an inspection object, and an inspection unit 3
And a transfer section 4 for transferring the wafer 2. The inspection unit 3 is provided corresponding to a chuck 5 that holds a wafer 2 in vacuum with the IC chip formation surface of the wafer 2 facing downward, and an electrode pad of each IC chip of the wafer 2 held by the chuck 5. And a probe card 7 having a stylus 6.

The probe card 7, as shown in FIG.
It is installed on the plate 8 of the apparatus main body casing 1 via an insert ring 9. In addition, each stylus 6 has a wiring 1
Performance board 1 of test head 11 by 0 etc.
Connected to 2. On the other hand, as shown in FIG. 4, the chuck 5 is provided on the X stage 14 below the Y stage 13, and together with the X stage 14 and the Y stage 13, X,
It is movable in the Y direction. Further, the chuck 5 is X
It has a structure that can move in the vertical direction (Z direction) with respect to the stage 14 and can rotate.

As shown in FIG. 3 or FIG.
Or, a supply nozzle 15 for supplying the air A cooled by an air conditioner or the like (not shown) and cleaned by a filter is disposed on the side of the X stage 14. The supply nozzle 15 is provided downward on the probe card 7 side. Further, at the bottom of the test head 11, a fan 16 is provided for sucking the cooling air A and forming a downflow of the air A. A caster 17 is attached to the test head 11 so that it can move on the floor portion 18. Further, the test head 11 is, as shown in FIG.
It is connected to the tester 20 by 9.

Further, an alignment bridge 21 is installed on the side of the inspection section 3, and the alignment bridge 2
1 is a T for detecting the position of the IC chip on the wafer 2 and detecting the trace of the stylus 6 on the dummy wafer.
Distance (height) in the Z direction from the V camera 22 to the wafer 2.
And a capacitance sensor 23 for detecting On the other hand, the X stage 14 is provided with a TV camera 24 for detecting the position of the stylus 6 of the probe card 7, as shown in FIG. Capacitance sensor 23 and TV camera 2
A target member 25 for correcting the deviation of the reference position of the detection system composed of 4 is attached. The target member 25 is a small piece made of glass, and a chromium cross mark 26 serving as a reference point for the TV cameras 22 and 24 is provided on the lower surface thereof.
And a conductive transparent thin film is applied so that the capacitance sensor 23 can detect the position in the Z direction.

Next, the operation of this embodiment will be described. First, the test head 11 with the casters 17 is moved on the floor 18 and installed in the inspection unit 3, and the performance hold 12 and the probe card 7 are electrically connected.
A cable 19 is connected between the test head 11 and the tester 20, but since the test head 11 is moved on the floor 18 by the caster 17, the cable 1
The risk of wire breakage or contact failure of the cable 19 due to bending of 7 or dragging over a long distance can be greatly reduced as compared with the conventional case.

Next, the X, Y stages 14 and 13 and the chuck 5 are driven to bring the electrode pads of each IC chip of the wafer 2 aligned with the chuck 5 into contact with the stylus 6 of the probe card 7 and the tester 20. Inspect the electrical characteristics by. In this inspection process, while supplying the cooled air A from the supply nozzle 15, the test head 11
The bottom fan 16 is rotationally driven. The air A blown from the supply nozzle 15 flows down the wafer 2, the probe card 7, and the performance board 12, passes through a through hole (not shown) formed in the upper plate surface of the test head 11, and enters the test head 11. The air flows in and is discharged from the bottom of the test head 11 by the fan 16.

When the test head 11 is driven, a large amount of heat is generated from the pin electronics of the test head 11, but the down flow of the cooling air A cools the probe card 7 and the like, and the heat generated by the test head 11 has an effect. Do not receive Further, since the downflow of the air A is formed, it is possible to prevent dust and the like from entering the apparatus main body casing 1 from the outside, and to keep the periphery of the wafer 2 in a clean state. Further, since the probe card 7 is below the wafer 2, dust such as an oxide film scraped off by the stylus 6 does not adhere to the wafer 2. Further, by controlling the flow rate and temperature of the air A, the temperature of the space around the chuck 5 and the probe card 7 can be kept constant.

Electrode pads on wafer 2 and probe card 7
Accurate positioning is required for contact with the stylus 6, but the reference points of the position detection system TV cameras 22 and 24 and the capacitance sensor 23 may deviate due to temperature and other reasons. There is. Therefore, the reference point of the detection system is corrected using the target member 25. That is, the cross marks 26 of the target member 25 are displayed on the TV cameras 22 and 24.
Is detected and the reference point of the X and Y coordinates is corrected. Further, the capacitance sensor 23 obtains the distance in the Z direction to the target member 25, and the TV camera 24 makes the cross mark 2
The distance in the Z direction up to 6 is obtained, and the reference point of the Z coordinate of the detection system is corrected from these detected values. The distance in the Z direction between the TV camera 24 and the cross mark 26 is detected based on the focusing of the TV camera 24 with the high and low magnification cameras.

In the above embodiment, the test head 1
1 has a caster 17 and can move on the floor 18, but it is not always necessary to have such a structure. For example, the test head 11 can be slidably attached via a guide rail. Good.

[0020]

As is apparent from the above description, according to the present invention, since the test head is the inverted type which is arranged below the probe device, the supporting mechanism and the moving mechanism of the test head can be simplified. The probe device can be made smaller and lighter. Since the downflow of the cooling gas flowing down the test head through the device under test and the probe card is formed, adverse effects such as deformation of the probe card due to heat generation of the tester head can be eliminated. Further, by forming the downflow of the cooling gas, it is possible to suppress the intrusion of fine dust and the like from the outside of the probe device, and reduce the deterioration of quality due to the adhesion of dust to the inspection object. Further, by controlling the downflow flow rate and temperature of the cooling gas, the ambient temperature of the object to be inspected and the like can be kept constant, and the accuracy and reliability of the inspection by the probe device can be further improved.

[Brief description of drawings]

FIG. 1 is a schematic front sectional view showing an embodiment of a probe device according to the present invention.

FIG. 2 is a partially cutaway plan view of FIG.

FIG. 3 is an enlarged front sectional view of a main part of FIG.

FIG. 4 is an enlarged perspective view of a moving mechanism of a chuck portion of the wafer of FIG.

FIG. 5 is a schematic configuration diagram of a conventional probe device.

[Explanation of symbols]

 2 wafer (inspection object) 5 chuck (holding means) 6 stylus 7 probe card 11 test head 15 supply nozzle 16 fan A cooled air

Claims (1)

[Claims] 1. A probe device for measuring electrical characteristics of an object to be inspected by a tester connected to an electrode pad of the object to be inspected with a stylus of a probe card and connected to the probe card via a test head. The probe stylus of the probe card is provided above the head, and the device under test is held above the probe card by holding means such that its electrode pad faces downward. And a down flow of the cooling gas flowing down the test head.