JPS592182B2 - Automatic semiconductor wafer measurement equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to an automatic semiconductor wafer measuring device, and, for example, to a technique effective for a fully automatic semiconductor wafer prober.

[Background technology]

In semiconductor wafer probers, which are responsible for the final checking process of semiconductor wafers, as the entrance diameter of semiconductor wafers increases, it becomes difficult to perform manual work using tweezers or other tools.
In other words, automatic loading and unloading of semiconductor wafers is known from pages 139 to 143 of the November 1978 issue of "Electronic Materials" magazine.

That is, a plurality of (eg, 25) semiconductor wafers are sequentially transferred one by one from a storage container (cassette) to a loading position (coarse alignment stage) by a round belt conveyor.

Then, this semiconductor wafer is transported to a suction table (measuring table) of a probing machine using a Bernoulli chuck or the like. Next, the semiconductor wafer that has been measured is transported from the suction table to an unloading position by blowing air pressure or the like, and placed in a storage container by a round belt conveyor.

As described above), the semiconductor wafer is carried into and out of the probing machine in a completely non-contact state with respect to the surface of the semiconductor wafer.

However, in such loading and unloading of semiconductor wafers, receiving storage containers are provided correspondingly to the sending storage containers, so for example, 50
When continuously measuring semiconductor wafers, two storage containers are required on the sending side and the receiving side.

Additionally, along with this, an elevator mechanism for sequentially storing semiconductor wafers one by one becomes necessary in accordance with the number of storage containers. This has disadvantages in that the cost of the device increases significantly and the device is molded. [Object of the Invention] An object of the present invention is to provide an automatic semiconductor wafer measuring device that achieves improved processing capacity, smaller device size, and lower cost.

The above and other objects and novel features of this invention include:
It will become clear from the description of this specification and the accompanying drawings.

[Summary of the invention]

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

That is, the semiconductor wafers constituting the third transfer route are connected between the semiconductor wafer transfer means constituting the sending route and the semiconductor wafer transfer means constituting the receiving route.
By providing the transfer means, after all the semiconductor wafers in the storage container used as the sending side have been sent out, the storage container can be used as the receiving side storage container. [Embodiment] FIG. 1 shows a schematic plan view of an embodiment of the present invention.

The automatic semiconductor wafer prober 1 in this embodiment is as follows:
Generally speaking, it is composed of a probing machine section 1a and a semiconductor wafer transfer section 1b.

As is well known, the probing machine section 1a moves a suction table 5, which suctions and fixes a semiconductor wafer placed on its upper surface, in the X and Y directions and rotates it in the θ direction using an X and Y stage. It consists of a fixed probe board or the like, and the tip of the probe is aligned with the bonding pad of the wafer chip with the tip arranged corresponding to the measurement location. In this positioning, aligning is performed to align the X-axis of the arrangement of chips on the semiconductor wafer with the X-axis of the X, Y displacement by adjusting the θ direction of the suction table 5. be.
After this, the bonding pad of the first wafer chip to be measured is aligned with the tip of the probe. Thereafter, the probe tip is automatically aligned with respect to the ponding pad of another wafer chip by continuously moving the tip in the X direction or the Y direction by one tip interval at a time. Movement of these X and Y stages and rotation control in the θ direction are performed with high precision using pulse motors. In addition, the suction table 5
is moved in the z direction (up, down) using an air or pulse motor.

That is, the positioning operation by controlling the X and Y stages is performed with the suction table 5 in a lowered state, and during measurement, the suction table 5 is raised and the required contact pressure is applied between the probe and the bonding pad of the wafer tip. The connection is made using The probing machine section 1a in this embodiment includes a transfer arm (described later).
is installed.

This transfer arm uses, for example, a Bernoulli chuck that suctions the semiconductor wafer below the surface without contact, and transfers the semiconductor wafer transferred to the load position 3 to the suction table 5 of the load position 5a. transport. Further, the semiconductor wafer for which the measurement has been completed is transported to the unload position 4 by blowing air or the like from the suction port after the suction table 5 moves to the unload position 5b.

A semiconductor wafer transfer section 1b is provided to the probing machine section 1a equipped with such an automatic loading/unloading mechanism for semiconductor wafers.

In this embodiment, the semiconductor wafer transfer section 1b has four elevator mechanisms 2a to 2d in which storage containers (power sets) for storing semiconductor wafers are installed, and also functions as a course alignment stage. Round belt conveyors 6a, 6b and 7a as well as a small round belt conveyor 6 connecting between loading position 3 and unloading position 4, respectively.
In addition to c, 6d and 7b, a new round belt conveyor 7A,
The core alignment stage constituting the 0 load position 3, which is provided with a round belt conveyor 8 that connects between the belts 7b and 7b, is provided with means for rotating the transferred semiconductor wafer and detecting an orientation flat, as will be described later. ,
A preliminary operation of positioning the semiconductor wafer in the θ direction is performed.

That is, the suction table 5 is moved by the transfer arm.
To facilitate the alignment work of semiconductor wafers transported to a computer, and to shorten the time or automate the alignment work. In this embodiment, four elevator mechanisms 2a
2d, for example, three elevator mechanisms 2a to 2
A storage container on the sending side is set in c, and a storage container on the receiving side (empty capacity set) is set in the other remaining elevator mechanism 2d.

Therefore, in the first step, the elevator mechanism 2a
The storage container of the elevator mechanism 2d is used as a sending side, and the storage container of the elevator mechanism 2d is used as a receiving side.

In this case, the semiconductor wafers are sequentially delivered one by one to the load position 3 via the round belt conveyor 7a by the elevator mechanism 2a and the round belt conveyor 6a. The semiconductor wafers carried out to the unloading position 4 upon completion of the measurement are transferred to the round belt conveyor 6d via the round belt conveyor 7b, and are stored one by one in the storage container of the elevator mechanism 2d. . Next, in the second step, the storage container of the elevator mechanism 2b is used as the sending side, and the storage container set in the elevator mechanism 2a, which has become empty after the above measurement is completed, is used as the receiving side.

In this case, similarly to the above, the elevator mechanism 2b and the round belt conveyor 6b sequentially transport the semiconductor wafers one by one.
is sent to the loading position 3 via the round belt conveyor 7a. The semiconductor wafer carried out to the unloading position 4 upon completion of the measurement is transferred to the position of the round belt conveyor 8 by the round belt conveyor 7b, and then transferred to the round belt conveyor 7a side by the round belt conveyor 8. be done. Then, the semiconductor wafer is transferred to this round belt conveyor 7a.
The sheets are then transferred to the round belt conveyor 6a and stored one by one in the storage container of the elevator mechanism 2a. In this way, the semiconductor wafers on the sending side and the receiving side are transferred one by one alternately.

Such a transfer operation is performed when the semiconductor wafer at position 3...
This is carried out during the period from when the semiconductor wafer is carried into the suction table 5 until it is carried out to the unloading position 4 (measuring operation of the semiconductor wafer). At this time, in order to shorten the loading operation to the suction table 5, the feeding side transfer operation (from the storage container to the loading position 3) is performed.
(transfer operation up to) and receiving side transfer operation (unload position 4).
It is desirable to give priority to the transfer operation from the storage container to the container. This is because the waiting time for measurement operations can be minimized. Thereafter, in the same way, the storage container of the elevator mechanism 2c is used as the sending side, and the storage container set in the elevator mechanism 2b, which has become empty after the measurement of the above step is completed, is used as the receiving side.

In this case, the round belt conveyor 6c-7b-8-7a is used as the sending side transfer route, and the round belt conveyor 7b-8-7a-6b is used as the receiving side transfer route. Note that sensors for detecting semiconductor wafers are provided at the transfer points between the round belt conveyors 9 and are used for transferring semiconductor wafers between the round belt conveyors as described above. That is, by detecting that the semiconductor wafer has been transferred to the above-mentioned delivery point, stopping the transfer operation of the round belt conveyor that carried out the transfer up to that point, and starting the transfer operation of the receiving side round belt conveyor. Then, the delivery will take place. In this embodiment, 1b' is a semiconductor wafer transfer section for expansion.

This expanding semiconductor wafer transfer section 1b' includes elevator mechanisms 2a', 2b' similar to those described above, round belt conveyors 6a7, 6b/ for taking out or storing semiconductor wafers, and these round belts. The round belt conveyors 7A, 7b are arranged perpendicularly to the conveyors 6a', 6b', respectively.
A round belt conveyor 7 connected linearly (on an extension line) to
a' and 7b' are provided. Thereafter, similarly configured expansion semiconductor wafers, transfer portions 1b, etc. can be sequentially installed. FIG. 2 shows a schematic plan view of another preferred embodiment of the invention.

The semiconductor wafer transfer section 1b in this embodiment has four elevator mechanisms 2a to 2d arranged in one example.

A round belt conveyor 8 is arranged perpendicularly to the round belt conveyors 6a to 6d provided in the elevator mechanisms 2a to 2d, respectively. Then, round belt conveyors 7A and 7b of the round belt conveyor 8, which go in the opposite direction to the round belt conveyors 6a to 6d and the same direction as the round belt conveyors 6a to 6d, move to the loading position 3, the unloading position 4, and the round belt. It is provided so as to be connected to the conveyor 8. In this embodiment, semiconductor wafers can be transferred via any combination of the round belt conveyors 6a to 6d and the round belt conveyors 7A and 7b via the round belt conveyor 8, as described above.

Therefore, one of the storage containers set in the four elevator mechanisms 2a to 2d can be used as a receiving side. In this embodiment, the round belt conveyor 7a transfers the semiconductor wafer from the round belt conveyor 8 to the load position 3, and the round belt conveyor 7b transfers the semiconductor wafer from the unload position 4 to the round belt conveyor 8. Since each transfer is performed in only one direction, there is an advantage that the control program can be easily executed.

FIG. 3 shows a plan view of a concrete embodiment of the round belt conveyors 7A, 6b, and 8, the load position 3, and the transfer arm 9 in the embodiment of FIG.

The round belt conveyor 7a runs a conveyor consisting of a pair of round belts by driving a pulley P by a motor (not shown) via a round belt. Thereby, the semiconductor wafer 10 is placed on top of the wafer and transferred. There are guides G on both sides of this pair of round belts.
D is provided. This prevents the semiconductor wafer 10 from falling off the round belt 7a and the like. The other round belt conveyors 6b and 8 are also constructed with a similar structure. Only a pair of round belts are shown in the round belt conveyor 8, and a driving pulley and a free pulley similar to those of the round belt conveyors 7A and 6b are provided at both ends of the belt. . Other round belt conveyors (not shown) are also constructed with the same structure as described above. Further, a sensor S is provided at the transfer point (connection point) between the round belt conveyor 8 and the round belt conveyors 7A, 6b. Although not particularly limited, this sensor S is constituted by an optical sensor and detects the semiconductor wafer transferred to the upper part thereof. For example, the semiconductor wafers to be measured are moved from right to left by the round belt conveyor 8.
When the semiconductor wafer 10 is transferred, the sensor S detects that the semiconductor wafer 10 has been transferred to this point,
The transfer operation of the round belt conveyor 8 is stopped. and,
By starting the operation of the round belt conveyor 7a, the transfer is performed and the semiconductor wafer 10 is transferred to the loading position 3. At the load position 3, an air outlet (not shown) is provided for blowing air, etc. from the lower surface side diagonally to the upper left in the figure. As a result, the semiconductor wafer 10 transferred by the round belt conveyor 7a is
It is rotated and transferred while being pressed against the tapered guide GD on the left side. As a result of this rotational transfer operation, when the orientation flat of the semiconductor wafer 10 comes into contact with the left guide GD, the rotation is stopped and preliminary positioning in the θ direction is performed. And, although not particularly limited,
The semiconductor wafer 10 is transferred to the suction table 5 (not shown) by a transfer arm consisting of a Bernoulli chuck 9a attached to a belt drive section 9b running vertically in the figure.

For example, the elevator mechanism 2b etc. is disclosed in Japanese Patent Application Laid-Open No. 54-4
Since it is well known from Japanese Patent No. 8482, etc., detailed explanation thereof will be omitted.

〔effect〕

(1) By providing a third transfer route that connects the semiconductor wafer transfer route that constitutes the sending side route and the semiconductor wafer transfer route that constitutes the receiving side,
By suppressing the continuous blowing of semiconductor wafers contained in N storage containers, the effect can be achieved by N+1 elevator mechanisms.

In other words, in the case of a conventional automatic semiconductor wafer prober, as many as 2N elevator mechanisms are required for continuous probing measurement of semiconductor wafers housed in N storage containers as described above. be. Therefore,
Compared to such conventional transfer methods, the present invention has the effects of improving semiconductor wafer processing capacity, reducing costs, and significantly downsizing the apparatus. (2) According to (1) above, since only one empty storage container is required, it is possible to efficiently use the storage container for semiconductor wafers.

(3) By adopting the transfer layout as shown in FIG. 2, the round belt conveyor 7a is replaced by the round belt conveyor 8.
The round belt conveyor 7b transfers the semiconductor wafer from the unloading position 4 to the round belt conveyor 8, which is the transfer operation in only one direction. This has the effect of making it easier.

Although the invention made by the present inventor has been specifically explained based on Examples above, this invention is not limited to the above Examples, and it is understood that various changes can be made without departing from the gist of the invention. Needless to say.

For example, when preparing an empty storage container as described above, it is sufficient that at least three or more elevator mechanisms are installed. The layout of the connection means between these elevator mechanisms and the loading position and unloading position can be modified in various ways, including the third route. In addition to the round belt conveyor described above, any means for transferring the semiconductor wafer may be used, such as an air bearing. Furthermore, the probing machine section may be one that automates needle alignment including alignment, or one that performs needle alignment by hand.

Operation control of the probing machine section and semiconductor wafer
- Although it is desirable to control the transfer operation by program control using a microcomputer or the like in order to increase the versatility of the system, the transfer operation is not limited to this, and may be controlled by a so-called hard logic circuit. [Field of Application] The present invention can be widely used in various automatic measuring devices for semiconductor wafers, such as semiconductor wafer probers, surface inspection devices, etc.

[Brief explanation of the drawing]

FIG. 1 is a schematic plan view showing one embodiment of the present invention, and FIG.
The figure is a schematic plan view showing another embodiment of the present invention.
The figure is a plan view showing a specific embodiment of the main part of the embodiment of FIG. 2. 1...Hakudo semiconductor wafer...measuring device, 1a...
...Probing machine section, 1b... Semiconductor wafer transfer section, 1b', 1b1... Semiconductor wafer transfer section for expansion, 2a to 2d... Elevator mechanism, 3...Loading position, 4...Unloading position, 5...Suction table, 5a...
...Opening position, 5b...Unloading position, 6a to 6d, 6a', 6bt...
...Round belt conveyor, 7a-7bt...Round belt conveyor, 8...Round belt conveyor (third route), 9a...Bernoulich, 9b
...Belt drive unit, 10...Semiconductor wafer, GD...Guide, s...Sensor, P...Pulley 1.

Claims (1)

[Claims] 1 Automatic loading of the semiconductor wafer to be measured onto the measurement table,
a semiconductor wafer measuring means equipped with an unloading mechanism; and a semiconductor wafer transporting means constituting a first route for transporting semiconductor wafers in a semiconductor wafer storage container installed on an elevator mechanism to a loading position of the semiconductor wafer measuring means. , a semiconductor wafer transfer means constituting a second route for transferring the semiconductor wafer at the unloading position of the semiconductor wafer measuring means to a semiconductor wafer storage container installed on another elevator mechanism; an elevator mechanism in which at least one semiconductor wafer storage container is provided for the second route; and a third elevator mechanism for mutually transporting the conductor wafer between the first route and the second route. An automatic semiconductor wafer measuring device comprising: a semiconductor wafer transfer means constituting a route.