JP2554341B2 - Probe device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention (Industrial field of application) The present invention mainly relates to a probe device for electrically measuring an object to be measured such as a semiconductor wafer.

(Prior Art) Due to high integration of the IC, the number of terminals that make up the IC increases,
The number of electrode pads per chip increases. As a result, a technology for measuring the electrical characteristics of the IC chip is also required, and it is necessary to increase the number of probe needles in the probe card. As an attempt to increase the number of probe needles, a probe card in which the probe needles are vertically mounted has been proposed. In such a probe card configuration, an elastically deformable ultrafine probe needle is vertically provided on the probe card at a position corresponding to the electrode array position of the IC chip.

Also, as a similar attempt, JP-A-58-173841 and JP-A-61-
There is an example disclosed in Japanese Patent No. 154137.

(Problems to be Solved by the Invention) However, in the probe needle vertical mounting type probe card, an opening portion for confirming the installation state of the IC chip is provided in the probe card because the probe needle is mounted vertically to the electrode pad. Is impossible. For this reason,
Since it was not possible to confirm the alignment between the probe needle array position and the IC chip electrode pad array position, it was difficult to connect the probe needle and the electrode pad accurately, and there was a problem in probe measurement.

The present invention has been made in consideration of the above points, and an object of the present invention is to provide a probe device capable of highly accurately aligning a probe needle of a probe card with an electrode pad of an object to be measured.

(Means for Solving the Problems) The present invention provides a mounting table for mounting and positioning an object to be measured, and a probe needle including a vertical needle arranged to face the object to be measured mounted on the mounting table. In a probe device provided with a probe card for performing electrical measurement of the object to be measured by contact, an opening is provided in the probe card, and light is passed through the opening to the object to be measured held on the mounting table. An irradiation unit that irradiates and reflects the light, a camera that receives the reflected light, and a control unit that pattern-recognizes the image output from the camera and controls the mounting table to align the DUT with the probe card. Be prepared.

The irradiation means preferably uses a semiconductor laser that emits laser light.

In addition, the probe card is held vertically at a right angle to the measured surface of the object to be measured by inserting a large number of probe needles and fixing holes that are provided through these probe needles and fixing them with an adhesive. It is desirable to provide a fixed base plate and a guide plate that is arranged in parallel with the fixed base plate and has a guide hole that conducts and guides the tip end portion of each probe needle.

(Effect of the Invention) According to the probe device having the above-described configuration, the object to be measured on the mounting table is irradiated with light through the opening provided in the probe card, and the reflected light is received by the camera. Since the pattern is recognized by the image pickup output by the control means to control the mounting table, the light irradiation position through the opening of the probe card is set at a position for positioning the measured object, for example, a predetermined electrode pad. So that the mounting table is moved and controlled, and in this state, the pattern is recognized by the camera to control the mounting table by the control means, and the probe needle of the probe card and the object to be measured, for example, The positioning with the electrode pad can be performed with high accuracy.

(Embodiment) An embodiment of the probe device of the present invention will be described below with reference to the drawings.

The probe card (1) is composed of a substrate portion (2) and a probe needle fixing portion (3) as shown in FIG.
The board part (2) is called a printed circuit board,
For example, printed wirings (5) are respectively insulated in an insulating state on an insulating substrate (4) formed of an insulating synthetic resin.
Each of the printed wirings (5) is configured such that one end thereof is connected to a terminal that is a tester for measuring and measuring a device under test, and the other end is connected to a probe needle (6). Further, at a predetermined position of the insulating substrate (4), for example, a position accurately determined from the mounting position of the probe needle (6), for example, a 50 μm square opening for controlling the light flux of the optical system, that is, an aperture (Aperture) 7) has been formed.

The probe needle fixing portion (3) is arranged on the substrate portion (2) having the above-mentioned configuration. The fixing portion (3) is provided with, for example, a through hole in the insulating substrate (4), and an insulating fixing substrate (8) made of a rectangular tube is provided in the hole.
Also, on the upper surface of the fixed substrate (8), as shown in FIG.
m is provided. That is, the fixing holes (9) are formed at positions corresponding to the electrode pad arrangement pattern of the IC chip of the object to be measured, for example, the semiconductor wafer (10).

A predetermined distance, eg, 10 parallel to the upper surface of the fixed substrate (8)
Insulating guide plates (11) with a spacing of mm, eg thickness 20
The guide plate (11) is coaxially provided with a guide hole (12) at a position corresponding to the fixing hole (9). That is, each fixing hole (9) for guiding the same probe needle (6) and each guide hole (12) are coaxially arranged. The probe needle (6) is made of an elastically deformable material such as tungsten having a diameter of 50 μm and is inserted into the fixing hole (9) of the fixed substrate (8). The middle part of the probe needle (6) is fixed. A guide hole (1) is provided at a position corresponding to the fixing hole (9) so that each probe needle (6) is vertically installed.
2) The probe needle (6) tip is installed in the guide plate (1).
For example, 300 μm is derived from 1). The tip of the probe needle (6) is radius-processed so as to make point contact with the electrode pad of the object to be measured. The other end of the probe needle (6), which is not the tip side, is respectively connected to a predetermined position of the printed wiring (5) of the board portion (2) by wiring connection, for example, by soldering. By configuring the probe needle fixing portion (3) as described above, the measured object such as the semiconductor wafer (1
The probe needles (6) are provided so as to be substantially perpendicular to the (0) plane, and the tips of the probe needles (6) are aligned with a plane orthogonal to each other within an allowable error range of, for example, about 10 μm.

The probe card (1) having the above-described configuration is arranged in the probe device (not shown). Here, as shown in FIG. 1, a half mirror (14) is arranged vertically above the aperture (7) formed on the probe card (1) at a predetermined inclination angle. ), The image pickup device such as a CCD camera (1
5) is installed. A light source such as a semiconductor laser (16) is installed in the horizontal direction of the half mirror (14). From this semiconductor laser (16), coherent light (17) with a uniform wavelength and phase is obtained.
To release.

Next, the alignment of the probe needle (6) of the probe card (1) and the electrode pad (18) of the IC chip formed on the wafer (10) using the above mechanism will be described.

First, the semiconductor wafer (10) is placed at a position facing the probe card (1). Next, the semiconductor laser (16) emits coherent light (17). Light emitted (17)
Is reflected by the half mirror (14) and converted to a predetermined angle. The reflected light passes through the aperture (7), is direction-controlled by the aperture (7), and is projected almost perpendicularly to the wafer (10) surface. This projection position is imaged by the CCD camera (15) installed above the aperture (7). At this time, the light (1
Pattern recognition is performed to determine whether the projection position of 7) is a predetermined projected position, for example, the electrode pad (18), and if there is an error (misalignment), correction and correction are performed as needed. The above-described operation is repeated at, for example, two predetermined projected positions on the wafer (10). In this way, when the predetermined projected position and the light (17) controlled by the aperture (7) are matched,
The projected position and the position of the aperture (7) are arranged so that the arrangement pattern of the probe needles (6) and the electrode pad pattern of the IC chip of the wafer (10) are aligned.

After the alignment of the probe needle (6) and the electrode pad (18), a measurement test of the electrical characteristics of the measured object is performed.

This measurement is performed by moving the semiconductor wafer (10) and the probe card (1), which are installed at positions facing each other in the probe card (1), in a relative vertical direction, for example, raising the wafer (10) to raise the probe card (1). Abutting on each probe needle (6). Here, the wafer (10) is further raised, for example, by 60 to 100 μm, that is, overdriven. By this overdrive, the oxide film or the like adhered to the electrode pad of the wafer (10) is destroyed at the tip of the probe needle (6), and the probe needle (6) and the conductive member of the electrode pad are accurately connected. At this time, the probe needle (6) is elastically deformed, for example, curved as shown in FIG. 3 (B). In this connection state, the test signal output from the tester is applied to the input electrode of the IC chip from the probe needle (6), and the electric signal generated at the output electrode of the IC chip is output from the other probe needle (6) to the tester. Then
The quality and function level of the IC chip are judged by comparing with the signal expected by the tester.

As mentioned above, the light provided by the optical system is irradiated to the aperture provided at the predetermined position of the probe card, and the light whose direction is controlled by this aperture and the predetermined projected position of the light of the measured object and By aligning with each other, the alignment can be performed without directly monitoring the connection between the probe needle and the measured object.

The present invention is not limited to the above-mentioned embodiment, and can be applied to any one as long as it relatively aligns at least two alignment objects such as a probe card and a measurement object. is there.

Further, the aperture shape is not limited to a square shape, and may be, for example, a cross shape or any other shape capable of controlling the direction.

 Still another embodiment will be schematically described.

As shown in FIG. 4, the plow card (19) is formed with an aperture (20) and a photographing hole (21) at predetermined positions at predetermined intervals. A coherent light (23) is projected from the semiconductor laser (22) onto the aperture (20) at a predetermined angle, and CC is projected through the photographing hole (21).
Confirm the projection position of the light (23) with the D camera (24). At this time, if the shooting hole (21) is made larger than the aperture (20), the field of view is large and the alignment is easy. The alignment of the projection position with a predetermined projection position of the object to be measured, such as a semiconductor wafer (25), such as an electrode pad (26), is performed by pattern recognition using the CCD camera (24). Even in the alignment method having such a configuration, the same effect as that of the above-described embodiment can be obtained.

As still another embodiment, an example in which an aperture is provided in a probe needle fixing portion of a probe card will be described with reference to FIG.

The probe needle fixing portion has a fixed substrate (29) in which the midpoint of the probe needle (27) is fixed with an insulating adhesive (28) and a guide plate (30) for guiding the tip direction of the probe needle (27).
And are arranged in parallel. For example, a 50 μm square opening, that is, an aperture (31) is formed at a predetermined position on the fixed substrate (29), and the guide plate (30) also has an aperture (30) on the fixed substrate (29). For example, an aperture (32) of 50 μm square is formed coaxially with 31).

A probe card having the apertures (31) (32) formed as described above, and an object to be measured, for example, a semiconductor wafer (33)
A method of aligning with will be described.

First, the semiconductor wafer (10) is installed at a position facing the probe card installation. Next, the semiconductor laser (34) emits coherent light (35). The emitted light (35) is converted into a predetermined angular direction by the half mirror (36), and the light (35) is converted into an aperture (31) and a guide plate (30) provided on the fixed substrate (29). ) Through the aperture (32). At this time, the direction of the light (35) is controlled by the apertures (31) (32) and is projected perpendicularly to the wafer surface. This projection position is imaged by a CCD camera (37) provided vertically above the apertures (31) (32) and the half mirror (36). At this time, it is pattern-recognized whether the projection position of the light (35) is an electrode pad formed at a predetermined projected position, for example, a predetermined position, and if there is an error, correction and correction are performed at any time. The above-mentioned operation is executed at a plurality of predetermined positions on the wafer (33) to perform accurate alignment between the probe card and the wafer (33).

As described above, by providing the aperture at the position adjacent to the probe needle, it becomes possible to improve the alignment accuracy.

[Brief description of drawings]

FIG. 1 is a diagram for explaining a positioning method for explaining an embodiment of the method of the present invention, FIG. 2 is an explanatory diagram of the probe card of FIG. 1, and FIG. 3 is an enlarged view of an essential part of FIG. Figure, 4th
5 and FIG. 5 are views for explaining another embodiment of FIG. 4 ... Insulating substrate, 7 ... Aperture 10 ... Semiconductor wafer, 14 ... Half mirror 15 ... CCD camera, 16 ... Semiconductor laser 17 ... Coherent light, 18 ... Electrode pad

Claims (3)

(57) [Claims] 1. An object to be measured is placed by contacting a mounting table on which the object to be measured is placed and positioned, and a probe needle composed of a vertical needle arranged facing the object to be measured mounted on the mounting table. In a probe device including a probe card for performing electrical measurement, an opening is provided in the probe card, and an irradiation unit that irradiates light to the object to be measured held on the mounting table through the opening and reflects the light, A probe apparatus comprising: a camera for receiving the reflected light; and a control means for pattern-recognizing an image output from the camera and controlling the mounting table to align the object to be measured with the probe card. 2. The irradiating means uses a semiconductor laser that irradiates a laser beam.
The probe device according to the item. 3. A probe card comprising a large number of probe needles and fixing holes provided through the probe needles and fixed by an adhesive so as to be substantially perpendicular to the measured surface of a pair to be measured. And a guide plate having a guide hole disposed parallel to the fixed substrate and having a guide hole for conducting and guiding the tip end portions of the probe needles in parallel with the fixed substrate. The probe device according to item 1.