CN1170747C - Inventory transfer system - Google Patents

Abstract

An inventory transfer system for use in a production line includes at least one processing station. The inventory transfer system includes a wafer box to contain at least one item to be transferred, an inventory station, a robot disposed between the at least one processing station and the inventory station for transferring the at least one item from the inventory station to and from the at least one processing station, and an overhead transfer system for transferring the wafer box into and out of the inventory station.

Description

stock transfer system

technical field

The present invention relates to an inventory system, and more particularly to an inventory transfer system used in a production line of semiconductor devices or optoelectronic devices, such as liquid crystal displays.

technical background

Semiconductor wafers (hereinafter referred to as "wafers") and LCD flat glass (hereinafter referred to as "flat glass") are the basic materials for producing VLSI chips and LCD devices, respectively. These materials are usually stored in carriers or pods and can only be handled and transported in extremely clean environments, as even the slightest particle of dust renders them impossible for further processing. Therefore, if VLSI chips and LCD devices are to be produced in a low-cost, high-yield and profitable manner, dust pollution must be controlled. The main sources of dust pollution are personnel, instruments, equipment (including clean rooms), and chemicals. Dust particles generated by personnel and cleanroom equipment are the most important source of contamination because they are easily ionized and can easily cause defects on the surface of wafers or flat glass. The constant trend has always been to build more sophisticated clean rooms with high-efficiency particulate air (HEPA) filters and air recirculation systems to thoroughly control dust pollution. Currently acceptable cleanliness in cleanrooms requires filter efficiencies as high as 99.99999%. In fact, due to the different personnel, materials, and equipment in the clean room, including filters, fans, etc., maintaining the desired clean environment in the clean room, such as a class 1 environment, will increase the cost.

In order to reduce the particle pollution of wafers and improve production yield in an effective cost-controlling manner, several technologies have been used to design improved storage stations (stock stations), combined with the concept of clean rooms, to store and transfer wafers with plate glass.

A known application of this concept is to use a conveyor system in a production line, which basically consists of four main parts.

First, at least one processing station is used to manufacture components. Typical processing stations are mask aligners, photoresist strippers, evaporation machines, and etch machines. The processing station faces a clean tunnel with the desired degree of cleanliness (e.g. class 1 cleanliness). On the other hand, the internal environment of the processing station requires additional maintenance and cleaning, so the processing station is usually installed in an equipment area with a lower cleanliness (such as class 1000).

Second, the wafer (or flat glass) carrier (cassette) is used to carry the wafer (or flat glass) into and out of a processing station, and to carry the wafer (or flat glass) between different processing stations.

Third, the known storage stations (inventory stations) for accommodating the aforementioned carriers (cassettes) are located in the aforementioned equipment area during idle periods in which wafers are processed, while the input/output ports are entirely within the cleanliness. Inside the stock station, a crane is usually used to move the carriers (cassettes) stored in the stock station.

Fourth, there is a transfer system between the processing station and the inventory station to move the carrier (cassette). The transport system preferably also includes an automated transport and handling system, typically a mechanical vehicle, commonly referred to as an automated guided vehicle (AGV), which is controlled via a wireless ground control system (FCS).

However, it is not the most cost-effective way to combine the clean room concept with the storage station and the automatic guided vehicle, because it uses the automatic guided vehicle to transport, it still needs to have a clean environment with an appropriate area, which must be equivalent to class 1 or better Optimum cleanliness, and AGV transfer times can also seriously increase manufacturing cycle times.

Contents of the invention

Therefore, an object of the present invention is to provide an inventory transfer system for the production line of semiconductor or LCD devices, by eliminating the automatic guided vehicle, to reduce the scope of class 1 clean environment and the transfer time of the automatic guided vehicle, thereby reducing production cost and manufacturing cycle time.

The present invention mainly comprises five main parts.

First, at least one processing station is used to manufacture components. Typical processing stations are mask aligners, photoresist strippers, evaporation machines, and etch machines. The processing station faces a clean tunnel with the desired degree of cleanliness (e.g. class 1 cleanliness). On the other hand, the internal environment of the processing station is kept clean, so the processing station is usually installed in an equipment area with a lower cleanliness (eg class 1000).

Second, carriers (cassettes) containing wafers (or flat glass) are used to carry wafers (or flat glass) into and out of a processing station, and to carry wafers (or flat glass) between different processing stations.

Third, the storage station (inventory station) for accommodating the aforementioned carriers (cassettes) is surrounded by cleaning lanes during idle periods in which wafers are processed. Cranes and storage racks are set inside the storage station for moving and storing carriers (cassettes) respectively.

Fourth, a robot is installed between the processing station and the storage station, and is completely within the scope of the clean channel, and is used to send and receive wafers (or flat plates) between the storage station and the processing station through the input and output ports of the wafer cassette. Glass).

Fifth, an overhead transport system is provided to move the carriers (cassettes) between each processing area and each storage station. This overhead transport system is suspended in the air and is located in the space above the robot.

Since there is no need to use an automatic guided vehicle system, and only a small-area class 1 environment is required, the disadvantages caused by using the known stock station system in the semiconductor or LCD production line can be avoided, so the production cost and the manufacturing cycle can be reduced obviously according to the present invention time.

To achieve the stated object, the present invention provides an inventory transfer system for use in a production line comprising at least one processing area including at least one processing station, the inventory transfer system comprising: a wafer pod, which accommodating at least one item to be transported; a storage station, including: a plurality of cranes arranged in the storage station for moving the wafer box in the storage station; at least one wafer box loading/unloading port, the wafer box Transported into and out of the inventory station via the load/unload port; a plurality of input/output ports through which the at least one item in the pod is transported in and out of the inventory station; and disposed in the inventory station a plurality of racks for accommodating the wafer box; and a robot disposed between the at least one processing station and the inventory station for transferring the at least one item in the wafer box from the inventory station and transmitted to the at least one processing station.

Brief description of the drawings

The above and other objectives, features, and effects of the present invention should be fully understood from the following detailed description of preferred embodiments and accompanying drawings.

Figure 1 shows a common production line arrangement utilizing common stocking stations and automated guided vehicles combined with a clean room concept.

Figure 2A shows a side view of a utility stocking station.

Figure 2B shows a top view of a common inventory station with automated guided vehicles.

Fig. 3 is a schematic diagram showing some special equipment of a small-scale production line utilizing the stock station system according to the present invention.

Figure 4 shows two small production lines, each of which uses an inventory transfer system according to the present invention.

Figure 5 shows the relative positions of a storage station, an overhead transport system, a robot, and a processing station in accordance with the present invention.

Detailed ways

Figure 3 shows part of the dedicated equipment for a predetermined small-scale production line 10, which includes the three basic elements of an inventory system: inventory stations, robots, and overhead transport systems. One inventory station 100 , five robots, and an overhead transport system 300 are shown in FIG. 3 . A carrier (such as a pod) 800 travels between processing stations in the mini-production line 10 . There are four main components within the inventory station 100, including: three cranes 400, five input/output ports to each robot 200, and a pod load for transporting pods between the inventory station and the overhead transport system /unloading port 600, and a number of racks in other parts of the main body of the storage station.

As shown in FIG. 3 , in a preferred embodiment of the inventory transfer system, items such as wafers or flat glass are accommodated in the i-th pod 800 on the Ri-th rack 700 in the inventory station 100 . When the Ci crystal boat box 800 is about to be processed by a specific processing station 901 (such as a thin film evaporation machine), the Nj responsible crane 400 near the Ci crystal boat box 800 is utilized to start from the Ri rack 700 , carry the i-th pod 800 to the P901-th input/output port 500 , and take out the contents from the it-th pod 800 , and transfer it to the processing station 901 by the T901-th robot 200 .

After the processing in the thin film evaporation machine 901 is completed, the item is sent into the Ci-th wafer cassette 800 in the P901-th input/output port 500 . Then, the Nj-th crane 400 in charge carries the Ci-th pod box 800 to the Oj/j+1-th area, which is the distance between the Nj-th crane 400 and the Nj+1-th crane 400's moving path Overlap. Then, the Nj+1 th crane 400 carries the Ci th wafer cassette 800 to the Ri+m th rack 700 . When the Ci-th wafer pod 800 is to be sent to the next processing station (e.g., a photoetcher 902) for coating photoresist and aligning the mask, the Nj+1-th crane 400 takes the Ci-th wafer The boat box 800 is taken out from the Ri+m-th rack 700 and sent to the P902-th input/output port 500, and the item is taken out from the Ci-th wafer box 800 and transferred to the processing station 902 by the T902-th robot 200.

FIG. 4 shows an overhead transport system for transporting pods within a mini-production line and between mini-production lines. The transport of pods in a small production line by an overhead transfer system is used to transfer the pods between two discontinuous processing areas. However, transporting the pods between small production lines by the overhead transfer system is to transfer the pods to another small production line to balance production capacity, or to apply in the case of a shutdown of an important processing station.

The overhead transmission system is suspended in the air, and its moving path surrounds each storage station, or at least extends to one side of each storage station, and is located above each robot between the storage station and the processing station, as shown in Figure 5. The moving path of the overhead transport system basically surrounds each storage station and connecting section, as shown in FIG. 4 .

Based on the above, the inventory system production line according to the present invention has the following advantages:

1. Since the transmission range of the automatic guided vehicle is not required, the manufacturing space can be greatly reduced.

2. Since there is no need to use automatic guided vehicles, the scope of class 1 environments can be reduced, which in turn can reduce the production cost of clean passages with class 1 or better cleanliness, and because no ground control system (FCS) is required, it can also The construction cost of the clean room can be reduced.

3. Since the steps of processing the wafer (or flat glass) by the automatic guided vehicle and the transfer time of the automatic guided vehicle are omitted, the processing cost of processing the wafer (or flat glass) can be greatly reduced.

The above detailed description of the preferred embodiments is only used to illustrate the technical content of the present invention, and the spirit and scope of the present invention are not limited thereto. All changes made according to the present invention belong to the spirit and scope of the claims of the present invention.

Claims (6)

1. An inventory transfer system for use in a production line comprising at least one processing area comprising at least one processing station, the inventory transfer system comprising: a pod containing at least one item to be transported; A storage station, comprising: a plurality of cranes arranged in the storage station for moving the wafer boxes in the storage station; at least one pod load/unload port through which the pods are transported into and out of the inventory station; a plurality of input/output ports through which the at least one item within the pod is transported into and out of the inventory station; and a plurality of racks disposed in the inventory station for accommodating the pods; and A robot, arranged between the at least one processing station and the storage station, is used to transfer the at least one item in the wafer box from the storage station to the at least one processing station. station. 2. An inventory transfer system according to claim 1, further comprising an overhead transfer system suspended in the air, the travel path of which is located in the space above said robot, and moves along at least one side of said inventory station, passing through said At least one pod load/unload port for transporting the pods into and out of the inventory station. 3. An inventory transfer system according to claim 1, wherein the travel paths of said plurality of cranes are located within said at least one processing area; and the travel paths of any two adjacent cranes overlap in a predetermined area in order to transfer the pods between the two adjacent cranes. 4. An inventory transfer system according to claim 1, further comprising at least one conveyor in said inventory station; wherein said plurality of cranes travels within said at least one processing area, said at least one conveyor The pod is carried from one of the plurality of cranes to an adjacent crane. 5. An inventory transfer system according to claim 1, comprising at least two processing stations, wherein said plurality of processing stations are arranged in two parallel rows, and each of said processing stations is connected via said robot to said inventory station link. 6. An inventory transfer system according to claim 2, further comprising at least two of said inventory stations, wherein said overhead transfer system is configured to pass through said at least one pod load/unload port within said inventory station, Transporting the pods into and out of between the at least two inventory stations.

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