JP2974482B2 - Rotating mechanism of test head of probing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotating mechanism of a test head in a probing apparatus for bringing a probe needle into contact with an electrode pad on a semiconductor wafer for inspection, and more particularly to a test head rotating mechanism connected to the probe needle. The present invention relates to a turning mechanism that can easily turn.

[0002]

2. Description of the Related Art To inspect a semiconductor wafer, a probe needle is brought into contact with an electrode pad of each chip on the semiconductor wafer, and a signal is inputted from a tester connected to the probe needle to each chip in accordance with a test pattern. This is performed by monitoring the output from each chip.

In recent years, the operating speed of semiconductors has tended to increase more and more, and there has been a problem that accurate measurement cannot be performed due to noise or the like when a cable for transmitting a signal from a semiconductor wafer to a tester is long. Therefore, a probing apparatus has been used in which a test head is arranged near a probe needle to make a cable as short as possible so that accurate measurement can be performed.

The test head is connected to the probe needle at the time of inspection, but it is necessary to retract the test head at the time of non-inspection because a microscope or the like is used to align the probe needle with the wafer. If the semiconductor wafer to be inspected changes, it is necessary to replace the probe card or the performance board, and it is necessary to retreat the test head for replacement or maintenance. Therefore, a probing device in which the test head 1 is rotatable as shown in FIG. 4 is used. In the case of a probing device, the probing device includes only a probe needle and a transfer mechanism for a semiconductor wafer and a portion attached thereto, and may not include a test head.However, in this case, the probing device includes a test head and a rotation mechanism of the test head. Shall be considered.

In FIG. 4, a test head 1 is held at one end of an arm 2 and is rotatable, and is connected to a probe needle 12 by a pogo pin. In the probing apparatus shown in FIG. 4, the rotation of the test head 1 is manually performed. However, as the degree of integration of semiconductors increases, the test head 1 becomes more complicated, and the test head 1 is enhanced in function such as simultaneous inspection of a plurality of chips to improve inspection efficiency. The size and weight have increased, and the weight has increased from 50 kg to 200 kg. For this reason, it is difficult to manually rotate the test head 1 using an apparatus as shown in FIG. 4, and various measures have been taken to enable easy rotation.

FIG. 5 is a diagram showing a conventional example of a probing device in which the rotation of the test head is facilitated, and FIG.
Is an example in which the arm 2 is supported by the gas spring 8 and the weight of the test head 1 is balanced by air pressure. However, in this method, it is impossible to completely balance the entire rotation range of the test head 1, and it can be applied only to a relatively light test head.

As a method of facilitating the rotation, a method which has been widely used in the past is a method in which a weight 9 is attached to the other end of the arm 2 as shown in FIG. If the test head 1 and the weight 9 are perfectly balanced, the test head 1 and the weight 9 can be rotated only by applying a very small force over the entire rotation range. However, as shown in the figure, if the length of the arm 2 on the weight 9 side is increased, there is a problem that the space in which the weight 9 rotates is increased. If the arm 2 is shortened, it is necessary to increase the weight of the weight 9 accordingly. There is a problem that the whole apparatus becomes heavy.

[0008] Japanese Utility Model Application Laid-Open No. 61-74882 discloses a test in which the position of the air cylinder 8 is rotated with the rotation of the test head 1 as shown in FIG. A head rotation mechanism has been proposed.
In Japanese Patent Laid-Open Publication No. Hei 3-63577, the air pressure applied to the air cylinder 8 shown in FIG. 6 is changed according to the weight of the test head 1, so that the present invention can be applied to a probing apparatus using different test heads 1. A rotation mechanism has been proposed.

[0009]

The test head rotating mechanism shown in FIGS. 5A and 5B has the above-mentioned problems. That is, it is difficult to completely balance the entire rotation range with the mechanism of FIG. 5A, so that it can be applied only to a relatively light test head. Supply is only via a flexible hose,
There is a problem that it is not possible to supply too high pressure air. The mechanism shown in FIG. 5B has a problem that a space for rotating the weight 9 like a pendulum is required.

Japanese Utility Model Application Laid-Open No. 61-74882 and Japanese Unexamined Patent Publication No.
The apparatus disclosed in JP-A-63-577 has a complicated mechanism and the above-described problem occurs because the position of the air cylinder 8 changes. SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and has a simple mechanism, which is completely balanced over the entire rotation range, and which is easily adaptable to test heads having different weights. For the purpose of realization.

[0011]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a rotating mechanism for a test head according to the present invention moves the other end of an arm holding the test head horizontally along a plane of a member which moves up and down. Then, a force is applied to this vertically moving member to balance with the test head. FIG. 1 is a diagram showing a basic configuration of a rotating mechanism of a test head according to the present invention.

That is, the turning mechanism of the test head of the present invention is a turning mechanism of the test head 1 connected to the inspection probe needles 12 of the semiconductor wafer 11 in the probing device, and turns about the fulcrum 6. A test head 1 attached to one end of the arm 2 and a balancing member 7 to which a force proportional to the weight of the test head 1 is applied to the other end of the arm 2. A moving mechanism 4 for moving the moving member 3 having a horizontal plane in parallel in a vertical direction, and pressurizing means 5 for applying a vertical force to the moving member 3. The arm 2 is configured so as to be movably supported in the direction, and that a force that balances with the test head 1 is applied to the arm 2 by the pressing means 5 via the moving member 3.

[0013]

The force applied to the moving member 3 by the pressurizing means 5 is applied to the balancing member 7 and balances the weight of the test head 1. The balancing member 7 is made of a cylinder, a bearing, or the like.
The force applied from the moving member 3 is always applied in a manner equivalent to that applied to a predetermined point such as a cylinder or the center of a bearing. This point must be on a straight line connecting the center of gravity of the test head 1 and the fulcrum 6.

As the test head 1 rotates, the balance member 7
Moves, and the moving member 3 also moves up and down. The contact point between the moving member 3 and the balancing member 7 moves in the horizontal direction. However, as described above, a force that balances with the test head 1 is applied to the balancing member 7, so that the moment force for rotating the arm 2 is It is almost zero, and the test head 1 can be easily moved over the entire rotation range by applying a small force.

Further, since the moving member 3 only moves in parallel in the vertical direction, it can be realized by a simple moving mechanism, and the force from the pressing means 5 only needs to be applied to a certain point from a certain direction. Means 5 can also be realized by a simple mechanism.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS As the pressing means 5 in FIG. 1, a heavy object may be placed on the moving member 3. Of course, the weight of the moving member 3 itself may be adjusted so as to be balanced with the test head 1, but the test heads 1 having different weights may be adjusted.
If there is a case where a weight is used, a desired weight may be obtained by placing a corresponding heavy object or combining a plurality of heavy objects. Placing a heavy object in this way is similar to using a balance weight shown in FIG. 5B, but placing it on a moving member 3 as shown in FIG. Is very easy.

Since placing a heavy object has a problem that the weight of the entire apparatus increases, the use of an air cylinder as the pressurizing means 5 can reduce the size and weight of the apparatus. FIG. 2 is a diagram showing an embodiment using an air cylinder. FIG.
, 51 is an air cylinder. Air cylinder 5
The air pressure obtained by adjusting the compressed air from the first air supply device 54 to a desired pressure by the first pressure adjustment device 55 is supplied to the first upper chamber 52, and is kept constant regardless of the position of the cylinder. Similarly, the lower chamber 53 of the air cylinder 51 is maintained at a constant air pressure by the second air supply device 56 and the second pressure adjusting device 57. The difference in air pressure between the upper chamber 52 and the lower chamber 53 acts on the cylinder. In the structure shown in FIG. 2, an upward force is applied to the balancing member 7 by the weight of the test head 1, so that it is necessary to apply a downward force to the moving member 3 in order to balance the upward force. Therefore, the upper chamber 52 of the air cylinder 51
Is made higher than the air pressure of the lower chamber 53, and the force obtained by multiplying the difference in air pressure by the area of the cylinder acts as a force for pushing down the moving object 3. Then, the difference in air pressure is set such that the pushing force is equal to the force for balancing the test head 1.

In FIG. 2, since the air pressure in the upper chamber 52 is increased, the lower chamber 53 is connected to the atmosphere in the room where the apparatus is installed.
The second air supply device 56 and the second pressure adjusting device 57 may be omitted. As is clear from FIG.
1 can be fixed, and the supply of compressed air is
It is much easier than the mechanism. It is desirable to use a hydraulic cylinder especially when it is necessary to apply a large force to the cylinder because a very heavy test head 1 is used. It is important that

A pneumatic pump is usually used as the air supply device, and a valve is used as the pressure adjusting device. It is easy to make the supplied air pressure equal to the atmospheric pressure by operating the valve. Therefore, when the test head 1 is connected to a pogo pin for connecting to a probe card, the force of the air cylinder 51 is released by operating a valve when the test head 1 contacts the pogo pin.
Thus, the connection to the pogo pins is performed by the weight of the test head 1. Needless to say, a stopping means is required so that the weight of the test head 1 is not applied to the probe needle as it is. After the connection to the pogo pin is completed, the valve is closed again to supply compressed air to the air cylinder.

Also, instead of completely opening the valve,
The difference in air pressure between the upper chamber 52 and the lower chamber 53 may be adjusted so that an appropriate force is applied. The above operations can be performed manually, but can also be automatically controlled using a microcomputer or the like. FIG. 3 shows an embodiment in which the air pressure is automatically changed in accordance with the replacement of the test head to maintain the balance with the test head.

In the embodiment of FIG. 3, only the air pressure of the upper chamber 52 of the air cylinder 51 is adjusted by adjusting the first electromagnetic valve 55 with the compressed air from the first pneumatic pump 54. The air pressure can be set to a desired value by controlling the first electromagnetic valve 55 with a signal from the microcomputer 58. The rotation of the test head 1 can be performed with a very small force because the rotational moment of the arm 2 is balanced. Therefore, manual operation is possible, but when a rotary drive source such as a motor is used, it can be performed with a small driving force. For example, it is also possible to attach a small motor to the rotation shaft of the fulcrum 6 for rotation, and the device capable of automatically controlling the rotation operation can be reduced in size and realized at low cost.

[0022]

According to the present invention, the rotation mechanism of the test head in the probing apparatus can be completely balanced over the entire rotation range with a simple mechanism. In addition, it is possible to easily cope with test heads having different weights including a large weight, and to realize a rotation mechanism that can be easily automated.

[Brief description of the drawings]

FIG. 1 is a diagram showing a basic configuration of a rotating mechanism of a test head according to the present invention.

FIG. 2 is a diagram showing an embodiment using an air cylinder.

FIG. 3 is a diagram illustrating a configuration of an embodiment in which air pressure is automatically changed according to replacement of a test head using a microcomputer.

FIG. 4 is a diagram showing a probing device in which a test head rotates.

FIG. 5 is a diagram showing a conventional example that facilitates rotation of a test head.

FIG. 6 is a diagram showing a rotation mechanism of a test head using an air cylinder.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Test head 2 ... Arm 3 ... Moving member 4 ... Moving mechanism 5 ... Pressurizing means 6 ... Supporting point 7 ... Balance member 11 ... Semiconductor wafer 12 ... Probe needle

Claims (7)

(57) [Claims] A rotating mechanism for a test head (1) connected to an inspection probe (12) for a semiconductor wafer (11) in a probing apparatus, the mechanism being supported to rotate about a fulcrum (6). Arm (2), the test head (1) is attached to one end of the arm (2), and a balancing member (7) to which a force proportional to the weight of the test head (1) is applied to the other end. In the rotating mechanism of the attached test head, a moving mechanism (4) for vertically moving a moving member (3) having a horizontal surface and a pressing means (5) for applying a vertical force to the moving member (3). The balancing member (7) is supported movably in the horizontal direction while being in contact with the horizontal surface of the moving member (3), and the moving member (3) is pressed by the pressing means (5). Through the test head A rotating mechanism for a test head of a probing apparatus, wherein a force that balances with the arm (1) is applied to the balancing member (7). 2. The rotating mechanism according to claim 1, wherein the pressing unit is a heavy object placed on the moving member. 3. The mechanism according to claim 1, wherein the pressurizing means is an air cylinder. 4. A pressure changing means for changing a force applied to said moving member (3) of said pressurizing means (5), wherein said moving member (3) is provided in accordance with a weight of said test head (1). 4. The mechanism according to claim 1, wherein the applied force is changed. 5. The force applied to the moving member (3) when the terminal of the test head (1) is connected to the socket of the probe needle (12) is released. A rotating mechanism of the test head of the probing apparatus described in the above. 6. When connecting or disconnecting the terminal of the test head (1) to the socket of the probe needle (12),
The mechanism according to claim 4, wherein the force applied to the moving member (3) is changed. 7. The test head according to claim 1, further comprising means for rotating a motor for rotating the arm, wherein rotation of the test head is automated. A rotating mechanism for the test head of the probing device.