JP2568104B2 - Probing method and probing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a probing method and a probing apparatus.

(Prior Art) In recent years, due to innovation in IC chip manufacturing technology, highly integrated and high-speed multifunction IC chips have been produced. Such IC chips are, for example, MUP, RAM, ROM, AL in one chip.
Various circuit parts such as U and TTL are connected by a conductive pattern. Here, it is necessary to measure the electrical characteristics of the IC chip not only for the entire measurement but also for each circuit unit. Therefore, in the above IC chip, for example, 70 to 100 μm square electrode pads for bonding on the periphery of the IC chip and 20 to 30 μm dedicated to measurement on the periphery of each circuit portion are used.
Corner electrode pads are provided. When measuring the electrical characteristics of such an IC chip, a semiconductor wafer on which a large number of IC chips are formed is placed on a movable mounting table, and the mounting table is sequentially moved in the horizontal direction at intervals of chips, each time in the vertical direction. It was necessary to move up and down to bring the probe needle of the probe card into contact with the electrode pad for bonding or the electrode pad dedicated to measurement, connect the tester and the IC chip, and perform the measurement.

(Problems to be solved by the invention) However, when measuring the above IC chip, the mounting table is usually 5 μm in view of mechanical accuracy due to moving speed and weight.
Since movement is controlled in units of m, 70 to 100 μm
There is no problem in contacting the probe needle of the probe card with a tip of about 50 μm to the corner bonding electrode pad, but the tip is 5
In order to contact the probe needle of about ~ 10μm, if the mounting table is moved in 5μm units, it is difficult to align the pad and the needle, and accurate contact cannot be obtained, and the circuit part measurement can be performed. There was a problem that it did not exist.

The present invention has been made in consideration of the above points, and provides a measuring method that can correspond to an electrode pad dedicated to measurement smaller than an electrode pad for bonding, and can perform highly accurate alignment at high speed. To do.

[Structure of Invention]

(Means for Solving the Problem) In the probing method according to claim 1 of the present invention, the electrode pad of the object to be measured mounted on the mounting table and the probe needle of the probe card are aligned and brought into contact with each other, and In the probing method of measuring the measurement object, after performing the rough alignment of the measured object by moving the mounting table in a range in which the movement can be controlled, the probe card from the mounting table It is characterized in that the probe card is finely aligned with the object to be measured while finely controlling the movement.

In the probing device according to claim 2 of the present invention, the mounting table is moved in the X, Y, Z, and θ directions so that the electrode pads of the object to be measured mounted on the mounting table are probe needles of the probe card. In the probing device for measuring the object to be measured by aligning and contacting with the probe, the probe card is separated from a base member supporting the probe card and finely moved in the X and Y directions to control the probe card. A fine movement mechanism for aligning the card with the object to be measured is provided, and the fine movement mechanism is provided on the base member and has a guide member having a guide surface in any one of the X and Y directions. A first slider that can be restrained by the guide surface of the guide member and can slide along the guide surface and the base member; and a first slider formed on the first slider. , A second slider fixed to the guide surface in any other direction of the Y direction and slidable along the guide surface and the base member, and fixed to the probe card, and both sliders individually. It is characterized by comprising a driving mechanism for driving and a distance detector for detecting a moving distance of each slider moved by the driving mechanism.

(Operation) According to the first and second aspects of the present invention, the electrode pad of the object to be measured placed on the mounting table and the probe needle of the probe card are aligned and brought into contact with each other to be measured. When measuring, first move the mounting table within its controllable range to roughly align the object to be measured with the probe card, and then use the fine movement mechanism to move the probe card from the mounting table. The probe card is finely aligned with the object to be measured while finely controlling the moving distance.
When aligning the probe card using the fine movement mechanism, for example, the first slider is separated from the guide surface and the base member in the Y direction, and the second slider is simultaneously or individually provided. After separating the guide surface in the X direction and the base member,
The drive mechanism is driven to move the first and second sliders separately on the base member simultaneously or individually. When the distance detector detects that the first and second sliders have moved by a predetermined amount, the first and second sliders are restrained by the respective guide surfaces and the base member and stopped, and the probe card is finely aligned. To finish.

(Example) Next, an example in which the measuring method of the present invention is applied to measurement of a semiconductor wafer by a probe apparatus will be described with reference to the drawings.

First, the structure of the probe device will be described. As shown in FIG. 1 and FIG. 2, an accommodating portion mainly accommodating an object to be measured, for example, a semiconductor wafer (1) on which a large number of IC chips are formed and having a preliminary alignment mechanism. (2) and a measuring section (3) for measuring the electrical characteristics of the device under test.

The storage section (2) has a plurality of mounting tables (5) on which the cassettes (4) capable of stacking, for example, 25 objects to be measured, such as semiconductor wafers (1), are arranged at predetermined intervals in the plate thickness direction. For example, two systems are provided. Each of the mounting tables (5) can be vertically moved by a ball screw (7) connected to a driving mechanism, for example, a motor (6), and the cassette (4) can be moved.
When carrying and carrying in the semiconductor wafer (1), the desired semiconductor wafer (1) can be installed at a predetermined carrying-out / carrying-in position.

Further, a transfer arm (8) is provided for unloading and loading the semiconductor wafers (1) housed in the cassette (4) one by one. The transfer arm (8) is provided on a transfer stage (not shown), such as a uniaxial moving mechanism including a linear guide, a ball screw, and a motor. A preliminary alignment stage (9) is provided to perform preliminary alignment of the wafer (1) transferred by the transfer arm (8). This preliminary alignment stage (9)
Is provided with a vacuum suction mechanism (not shown) so as to fix the semiconductor wafer (1) on the mounting surface. In addition, the pre-alignment stage (9) is moved up and down, and is provided with a drive mechanism (17) (not shown), such as a uniaxial movement mechanism using a ball screw and a motor, and a rotation mechanism using a timing belt and a motor, so that the θ rotation can be performed. It is provided.
Further, a light emitting / receiving sensor (not shown) for the preliminary alignment is provided near the preliminary alignment stage (9).

The storage section (2) is configured as described above, and the measurement section (3) will be described next.

The measuring section (3) is provided by being connected to the left or right side of the storage section (2) having the above-mentioned configuration, and the wafer (1) transferred from the storage section (2) is measured by the measurement section (3). Is configured. This measuring unit (3) has a semiconductor wafer (1)
A mounting table (10) for mounting the wafer is provided, and a vacuum suction mechanism (not shown) is provided so as to fix the semiconductor wafer (1) on the mounting surface. In addition, the mounting table (10) is controlled at intervals of 5 μm in consideration of high speed, weight, etc., so that the mounting stage (10) can move in the X direction, Y direction, Z direction (vertical direction), and θ direction (rotation direction). 11) For example, it is provided in a three-axis moving mechanism (not shown) that uses a linear guide, a ball screw, and a motor, and a rotation mechanism (not shown) that uses a motor. Within the movement range of the mounting table (10) by the movement stage (11), a pattern recognition mechanism or a laser recognition mechanism using a CCD camera for aligning the pattern formed on the semiconductor wafer (1) as a reference. Further, there is provided an alignment section (12) including a capacitance sensor and the like for recognizing an installation state such as a height change of the semiconductor wafer (1).
A probe card (14) for connecting the IC chip (13) formed on the semiconductor wafer (1) and a tester (not shown) is provided above the predetermined position of the mounting table (10). . As shown in FIG. 4, the probe card (14) has a tip diameter corresponding to, for example, an array of 70 to 100 μm square electrode pads (15) for bonding, which are provided on the periphery of the IC chip (13). 50 μm probe needles (16) are arranged, or each circuit part (1) of the IC chip (13)
7) For example, a probe needle (16) having a tip diameter of, for example, 5 to 10 μm corresponding to an electrode pad (18) array of 20 to 30 μm square dedicated to measurement provided on the periphery of MPU, RAM, ROM, ALU, TTL, etc.
Are arranged, or the probe needles (16) sharing these are arranged. Then, the electrode pads (15) and (18) are brought into contact with the probe needles (16) to enable electrical measurement. In addition, at the time of this contact, it is possible to align the electrode needle (15) for bonding with the corresponding probe needle (16), but to the extremely small electrode pad (18) dedicated to measurement,
The positioning for contacting the corresponding ultra-fine probe needle (16) may not be possible because the mounting table (10) is controlled at intervals of 5 μm. Corresponding to this, as shown in FIG. 3, the probe card (14) is configured to be finely movable. The fine moving mechanism (19) is installed on the base member (20) which is the upper surface of the measuring unit (3) having a highly accurate plane. A guide rail (23) having a suction plate (22) attached to a guide surface (21) is fixed to a predetermined position of the base member (20). An L-shaped slider (26) to which a two-system air bearing (24) and a magnet (25) are attached so as to face the guide surface (21) of the guide rail (23) has a Y direction (27).
It is provided as a slidable first slider. An air bearing (28) is provided on the lower surface of the L-shaped slider (26) so as to face the base member (20), for example, three systems. Also, the X of the L-shaped slider (26)
The surface is a guide surface (31) of a rectangular slider (30) provided as a second slider that is slidable in the X direction (29). Here, the attraction plate (32) is attached to the guide surface (31), and the magnet (33) is attached to the surface of the slider (30) facing the attraction plate (32). Further, the slider (30) is provided with two systems of air bearings (34) so as to face the guide surface (31), and the lower surface of the slider (30) has an air bearing (35).
However, three systems, for example, are provided facing the base member (20).

The air bearings (24) (34) blow pressurized air onto the guide surfaces (21) (31) from the respective air bearings (24) (34), whereby the attraction plates (22) of the sliders (26) (30) by the magnets (25) (33). The sliders (26) and (30) are separated from the guide surfaces (21) and (31) by overcoming the attraction force to the (32), and the air bearings (28) and (35) respectively supply pressurized air from the base members (20). ) Spray on the probe card (1
The sliders (26) (30) are separated from the base member (20) against the weight of 4) so that the sliders (26) (30) can slide. And air bearings (24)
When the pressurized air is not blown from the (28), (34) and (35), the sliders (26) and (30) are restrained in their respective positions by the action of the magnets (25) (33) and the attraction plates (22) (32). I am unable to move.

The slider (30) as described above is engaged with a drive motor (not shown), and has an X direction (29) and a Y direction (2).
It is possible to move to 7). Further, in order to control this movement for every 1 μm, a laser scale (36) is provided on each of two adjacent sides of the slider (30), and the laser length measurement is performed facing each laser scale (36). A vessel (37) is provided for distance detection. The probe card (14) described above is attached to the lower surface of the slider (30) whose movement can be controlled by 1 μm so as to project from an opening (not shown) provided in the base member (20). ing.

Then, a transfer means for transferring the semiconductor wafer (1) from the preliminary alignment stage (9) of the storage section (2) to the mounting table (10) of the measurement section (3), for example, engagement with a rotation motor (not shown) A rotating arm (38) is provided corresponding to the height position of the table (10). The rotary arm (38) has a side surface semicircular notch formed at the tip end position, and is configured to vacuum-suck the semiconductor wafer (1) at the tip end. Further, the rotating arm (38) has the same shape for loading and unloading in the measuring section (3) and is installed vertically with a predetermined interval.

The operation of the probe device including the measuring unit (3) and the storage unit (2) as described above is controlled and controlled by a control unit (not shown).

Next, a method of measuring an object to be measured, for example, a semiconductor wafer (1) by the above-described probe device will be described.

First, a cassette (4) containing, for example, 25 semiconductor wafers (1) is loaded into each cassette mounting table (5) and set by a robot hand or a manual. Then, the cassette mounting table (5) is moved up and down to set the first wafer (1) to be measured at a predetermined height position. Here, the transfer arm (8) is slid to place the wafer (1) on the preliminary alignment stage (9). After vacuum suction of the wafer (1) with this preliminary alignment stage (9),
The wafer (1) is rotated, and the light emission / light reception sensor performs centering of the wafer (1) and preliminary alignment is performed with reference to the orientation flat. After that, the wafer (1) is transferred to the mounting table (10) of the measuring unit (3) by the rotating arm (38) and vacuum-adsorbed. Then, the mounting table (10) is moved to the alignment section (12) by the moving stage (11), and the pattern is accurately aligned with the pattern of the scribe line or the like of the wafer (1) as a reference. After this alignment, place the mounting table (10) on the probe card (1
4) Move to the installation facing position, rotate the probe card in θ direction, align with the X / Y direction of the measurement stage, and move up at a predetermined position, and the IC chip (13) formed on the wafer (1)
The probe needles (16) of the probe card (14) are brought into contact with the electrode pads (15) (18) of, and the electrical characteristics of the IC chip (13) and each circuit part (17) are inspected by a tester (not shown). Make a measurement. Here, in this contact inspection measurement,
When the entire inspection of the IC chip (13) is performed, the probe needle (16) corresponding to the electrode pad (15) is brought into contact with the bonding electrode pad (15) formed on the periphery of the IC chip (13). Probe card (14)
Is fixed, and the mounting table (10) is sequentially controlled at intervals of IC chips (13) in the X and Y directions with 5 μm as one unit,
This is done by moving. Further, in order to bring the probe needle (16) corresponding to the electrode pad (18) into contact with the electrode pad for measurement (18) formed on the periphery of each circuit part (17), the electrode pad for measurement (18) Is extremely fine, the mounting table (10) is moved in the X and Y directions while controlling it in units of 5 μm, and at the same time, the probe card (14) is moved in the X and Y directions while controlling 1 μm as a unit. To move the probe card (14), first, for example, the air bearings (28) and (35) provided on the slider (26) for the Y direction (27) and the slider (30) for the X direction (29) are used. Air of 2-3 kgf / cm ² is supplied, for example, at about 0.2 / min. As a result, an air flow film is generated between the sliders (26) (30) and the base member (20) and separated. At the same time, the air bearing (24) of the slider (26) facing the guide surface (21) of the guide rail (23) for the Y direction (27) and the guide for the X direction (29) of the slider (26). Compressed air similar to the above is supplied to the air bearings (34) of the slider (30) facing the surface (31). By each guide surface (21)
An air flow film is generated between the (31) and each slider (26) (30), and the mechanical friction portion disappears. In such a state, each motor (not shown) is driven selectively or simultaneously,
Slide each slider (26) (30). That is, since the probe card (14) is arranged on the slider (30), the probe card (14) is moved to the X-axis by the above operation.
-Smooth slide movement in the desired direction in the Y direction (29) (27) is possible. Here, at the time of this movement, the slider (30) is provided with the laser scales (36) at two positions, one for the X direction and one for the Y direction, and the laser length measuring device (37) facing the respective scales (36). The amount of movement is detected from the above, and the amount of movement is controlled in units of 1 μm by a control unit (not shown). As described above, the mounting table (10) is moved at a high speed for rough alignment, and the probe card (14) is finely moved for fine alignment. Then, after accurate alignment, the mounting table (10) is raised to bring the electrode needle (18) dedicated to measurement of the IC chip (13) into contact with the probe needle (16), and perform electrical measurement with a tester (not shown). Run. By repeating such measurement operation, the IC chip (1
3) and each circuit part (17) formed in the IC chip (13) are measured.

In the above-mentioned embodiment, the alignment is carried out by the electrode pad exclusively for measurement, but the electrode pad for bonding may be formed, for example, in a size of 50 μm square or less. Further, the positioning may be performed only by moving the probe card without moving the mounting table to perform the rough positioning.

As described above, according to this embodiment, the probe card is finely moved to perform the fine alignment accurately, so that the accurate measurement can be performed and the yield can be improved.

As described above, according to the present invention, the mounting table X,
In addition to the positioning mechanism that moves in the Y, Z, and θ directions, a fine movement mechanism that finely moves a probe card that is lighter than the mounting table is provided, and the mounting table is moved within a range in which its movement can be controlled, and the object to be measured is moved. After the coarse alignment of the probe card to the probe card, the probe card can be finely aligned with respect to the measured object while finely controlling the movement of the probe card from the mounting table. It can also be used as an electrode pad for measurement, and can perform highly accurate positioning at high speed.

[Brief description of drawings]

FIG. 1 is a block diagram of a probe device for explaining the method of the present invention, FIG. 2 is a top view of FIG. 1, FIG. 3 is a block diagram of the fine movement mechanism of FIG. 1, and FIG. Enlarged view of the IC chip that is the object to be measured in the figure 1 …… Semiconductor wafer, 2 …… Storage unit 3 …… Measuring unit, 10 …… Mounting table 11 …… Movement stage, 14 …… Probe card 16 …… Probe needle , 19 ... Fine movement mechanism

Claims (2)

(57) [Claims] 1. A probing method for measuring an object to be measured by aligning and contacting an electrode pad of the object to be measured placed on a mounting table with a probe needle of a probe card,
After performing the rough alignment of the object to be measured with respect to the probe card by moving the mounting table within a range in which its movement can be controlled, the probe card while finely moving and controlling the probe card from the mounting table is used. A probing method characterized in that fine alignment is performed on the object to be measured. 2. The measuring table is moved by moving the mounting table in X, Y, Z and θ directions so that the electrode pad of the measured object mounted on the mounting table is aligned with and brought into contact with the probe needle of the probe card. In a probing device for measuring a body, the probe card is spaced apart from a base member supporting the probe card, and the movement of the probe card is controlled more finely in the X and Y directions than the mounting table to finely position the probe card with respect to the object to be measured. A fine movement mechanism for performing alignment is provided, and the fine movement mechanism can be restrained by a guide member provided on the base member and having a guide surface in one of the X and Y directions, and the guide surface of the guide member. A first slidable along the guide surface and the base member
The probe card is fixed so that the slider and the guide surface formed on the first slider in either the X or Y direction can be constrained and can be slid along the guide surface and the base member. A probing device comprising: a second slider, a drive mechanism that individually drives both sliders, and a distance detector that detects a moving distance of each slider moved by the drive mechanism.