JPH03211857A - Container for semiconductor wafer cassette - Google Patents

Abstract

PURPOSE:To make adjustment so as to prevent the occurrence of a differential pressure even when a differential pressure is produced between the inside and outside of the title container by a temperature difference, etc., between the inside and outside so that no contaminated air can be sucked into the container by providing a differential pressure adjusting means which adjusts the differential pressure between the inside and outside of the container. CONSTITUTION:In the case a differential pressure is produced between the inside and outside of this semiconductor wafer cassette container 10 when the container 10 is moved with cassettes for wafer inside, the inside pressure of the container 10 is maintained at a fixed level by means of an elastic deforming section 12 which makes elastic deformation in accordance with the differential pressure. Namely, when the inside pressure becomes higher than the pressure of the outside air, the section 12 deforms outward and the volume of the container 10 increases, resulting in a reduction in the inside pressure and a balanced state between the inside and outside pressures. Therefore, entrance of the outside air into the container 10 can be prevented and the cleanliness in the container 10 can be maintained regardless of the change in the inside pressure.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a semiconductor wafer cassette storage container used in the field of semiconductor manufacturing such as VLSI and IC.

``Prior Art'' As is well known, a large amount of dust is generated in the manufacturing process of semiconductor devices, especially in the process of forming circuit elements on semiconductor wafers, and during the transfer of wafers between manufacturing equipment. Cleanliness is directly linked to product yield.

As shown in FIG. 8, this semiconductor wafer cassette storage container 1 includes a box-shaped case body 2, a removable bottom plate 3 that seals the case body 2, and is stored on the bottom plate 3.
It consists of a semiconductor wafer cassette storage shelf 5 that stores a predetermined number of semiconductor wafers 4 . Further, a portable grip portion 6 is provided on the upper surface of the case body 2.

The bottom plate 3 of the semiconductor wafer cassette storage container (2) is configured to be detachable from the case body 2 by a latch mechanism (not shown) provided on the case body 2. The case body 2 and bottom plate 3 of the semiconductor wafer cassette storage container 1 are fixed to each other by this latch mechanism during transportation, but the wafer storage shelf 5 in the semiconductor wafer cassette storage container 1 can be removed if necessary.

Therefore, in this SMIF Nostem, the conductor wafer 4 is isolated from the outside air and its surface is covered with clean air, regardless of whether it is being processed in the semiconductor univaccent storage container or being transported by workers. Because of this, the cleanliness inside the clean room ranges from class 1000 to class IQ 00.
Even if the product is about 0.000, it is necessary to maintain a high yield rate of the product.

By the way, regarding the semiconductor univaccent storage container described in 1iii.1, the storage container is difficult because the gap between the case body 2 and the bottom plate 3 is sealed with a gasket. There is a limit to the sealing accuracy within the storage container 1, and it is difficult to completely eliminate the intrusion of outside air due to changes in the internal pressure of the storage container 1. For this reason, dirty outside air -) ゛1! ', there was a problem in that dust adhered to the conductor wafer 4 and the yield rate of the semiconductor wafer 4 decreased.

This invention prevents outside air from entering the container l no matter how much the internal pressure of the storage container l for the semiconductor univaccent changes.
The problem is how to realize a semiconductor wafer cassette storage container 41 that can be used to store a semiconductor wafer cassette and that can secure the raw material inside the container l.

[-Means for Solving the Problems] As a first aspect of the present invention, a case Jl for semiconductor wafers is provided.
・Is it a sealable semiconductor Ueno/cassette storage container that can store cassettes for semiconductor Ueno? :(It is characterized by being equipped with one stage of differential pressure adjustment stage to adjust the differential pressure between the inside of the unit and the outside air.

Further, as a second aspect of the present invention, a semiconductor wafer cassette is stored in a sealable semiconductor wafer cassette storage container, the filtration means communicating with the outside air being 1fJt.
It is characterized by being marked with J.

1 Effect 1 In the present invention, the differential pressure adjusting means provided in the semiconductor wafer cassette storage container is elastically deformed in response to the differential pressure between the inside of the storage container and the outside air, and keeps the internal pressure in the storage container 2 constant. can be held.

In other words, with such a structure, when the internal pressure of the storage container becomes higher than the pressure of the outside air, the differential pressure adjustment means provided in the storage container is elastically deformed outward from the storage container, causing the container to collapse. It acts to reduce the internal pressure of the storage container by expanding its internal volume, thereby balancing the pressure with the outside air.

Conversely, when the internal pressure of the storage container becomes lower than the pressure of the outside air, the differential pressure adjustment means installed in the storage container is elastically deformed inward, causing the container to The internal volume of the storage container is reduced to maintain the internal pressure of the storage container, thereby balancing the pressure with the outside air.

In this way, even if a differential pressure is generated between the inside and outside of the storage container due to a temperature difference between the inside of the storage container and the outside air, the IAI is adjusted by the differential pressure adjusting means so that the pressure difference does not occur between the inside and outside, and the outside of the storage container is adjusted. Be careful not to inhale dirty air.

Furthermore, if the storage container is provided with a filtration means, the airflow generated by the pressure difference between the internal pressure of the storage container and the pressure of the outside air is filtered by the filtration means, and if the outside air is absorbed by the pressure difference and the The i1#1 means installed in the storage container removes dust before it is absorbed from the joint with the bottom plate to prevent it from being sucked. Therefore, since the cleanliness inside the storage container is not affected in any way, the semiconductor wafers stored in the storage container are stored without coming into contact with contaminated outside air.

(One Embodiment) Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

1 to 4 are diagrams showing a first embodiment of the semiconductor wafer cassette storage container of the present invention.

In FIGS. 1 to 4, reference numeral I designates a semiconductor wafer cassette storage container installed in a clean room.

The structure of this semiconductor wafer cassette storage container 1 is as follows.
It is almost the same as a semiconductor wafer cassette storage container with an MIF system attached.

Therefore, the same components are given the same reference numerals,
The explanation will be omitted.

Here, the semiconductor wafer cassette storage container IO includes a box-shaped case body 2 as described above, a removable bottom plate 3 that seals the case body 2, and a predetermined number of semiconductor wafers stored on the bottom plate 3. It consists of a conductor wafer cassette storage shelf 5 for storing conductor wafers and cassettes. The bottom plate 3 of the semiconductor wafer cassette storage container 2310 is threadedly coupled to the case body 2 via the sealing member 11, and is configured as an attachment/detachment opening 71 from the case body 2.

An elastically deformable portion 12 is provided on the side surface of the case body 2 as a differential pressure adjusting means, and the outer surface of this elastically deformable portion I2 is provided with:
A casing 13 is provided so as to cover this elastically deformable portion 12 rQ.

Next, the operation of the 1'-conductor wafer cassette storage container according to the present invention will be explained with reference to FIG.

First, with the wafer cassette stored in the storage container 10, move the storage container 10.

At this time, for example, when moving from one clean room to another clean room, even if a pressure difference occurs between the inside and outside of the storage container 10 due to an external temperature difference during this movement, the storage container 10 The elastic deformation part!2 provided in
It is elastically deformed in accordance with the pressure difference between the inside of the storage container IO and the outside air, so that the internal pressure of the storage container 10 can be maintained constant.

In other words, in such a structure, when the internal pressure of the storage container 10 becomes higher than the pressure of the outside air, the storage container 1
The elastic deformation section 12 provided at the storage container 10 is elastically deformed outward of the storage container 10 as shown by the chain line 1 in FIG. It acts to lower the pressure and balance the pressure with the outside air.

Conversely, when the internal pressure of the storage container 10 becomes lower than the pressure of the outside air, the elastic deformation section 12 provided in the storage container 10 deforms the storage container 10 as shown by the chain line 11 in FIG. 10 is elastically deformed inward to reduce the volume inside the storage container 10 and maintain the internal pressure of the storage container 2 (10) to balance the pressure with the outside air.

In this way, when a pressure difference is generated between the inside and outside due to the temperature difference between the inside of the storage container IO and the outside air, the elastic deformation section provided as a pressure difference adjustment means! 2, the pressure is adjusted so that no differential pressure is generated between the inside and outside, and the dirty air outside the storage container IO is not sucked.

Such an action can prevent outside air from being drawn into the storage container 2510, thereby improving the quality of the semiconductors without contaminating the wafers in the storage 4'' with outside air.

Next, a second embodiment of the semiconductor wafer cassette storage container of the present invention will be described with reference to FIGS. 5 to 7. Incidentally, parts having the same configuration as in the embodiment described in rrlJ are given the reference numerals (")" and their explanations will be omitted.

The semiconductor wafer cassette storage container 15 in the embodiment of the present invention has almost the same configuration as the semiconductor wafer cassette storage container 10 in the embodiment of the invention, and includes an elastic deformation portion as the differential pressure adjusting means of the invention. The difference is that a filter 16 as a filtering means is provided instead of 12.

Said filter! No. 6 is for removing contaminants, so it can be used even in cases where high cleanliness is required.

In this way, when the storage container 15 is provided with a filtration means, the filter 16 filters the air flow generated by the pressure difference between the internal pressure of the storage container 15 and the pressure of the outside air. Dust that is absorbed from the joint between the case body 2 and the bottom plate 3 is removed by a filter 16 provided in the storage container 15 to prevent it from being sucked.

In other words, as shown in FIG. 7, when the internal pressure of the storage container I5 becomes higher than the external pressure, the airflow as shown by the dashed line r in the drawing occurs in the storage container! Conversely, when the internal pressure of the storage capacity Rl 5 is lower than the external pressure, an air flow as shown by the chain line ■ in the figure is generated from the outside air toward the inside of the storage container 10. .

Dust is removed in either of these air flows 1 and H when they pass through the filter 16.

Hence the storage container! Even if outside air were to flow into the storage container I5, it would not have the same effect on the cleanliness of the storage container I5.
It is stored without being exposed to F-dyed outside air.

``Effects of the Invention'' As explained in detail above, according to the present invention, there is provided a sealable semiconductor wafer cassette storage container for storing a semiconductor wafer cassette. Since the structure is equipped with a differential pressure adjustment means for adjusting the differential pressure between the inside of the storage container and the outside air, even if a difference in pressure occurs between the inside and outside due to a temperature difference between the inside of the storage container and the outside air, the difference will be maintained. a, -1 so that differential pressure does not occur between the inside and outside by the pressure adjustment means.
to prevent the outside of the storage container from sucking in dirty air.

In addition, the semiconductor wafer storage container is capable of storing and sealing the semiconductor wafer cassette, and is equipped with a membrane filtration means that communicates with the outside air, so that the internal pressure of the storage container and the pressure of the outside air are Since the air flow generated by the pressure difference is filtered by the filtering means, even if outside air is absorbed by the pressure difference, the dust is removed by the filtering means provided between the container body and the bottom plate and is not sucked. Therefore, since the cleanliness inside the storage container is not affected to the same extent, the semiconductor wafers stored in the storage container can be stored without coming into contact with contaminated outside air.

1 Description of the drawing "Drawing, Z,';i! ii: w'-'
;L Figures 1 to 4 are views showing a first embodiment of the present invention, in which Figure 1 is a perspective view of the semiconductor wafer cassette storage container of the present invention, Figure 2 is a front view, and Figure 3 is a perspective view of the semiconductor wafer cassette storage container of the present invention. is a side view, 4th
The figure is an enlarged sectional view of the vicinity of the difference [E adjustment means]. 5 to 7 are diagrams showing a second embodiment of the present invention, in which FIG. 5 is a front view, FIG. 6 is a side view, and FIG. 7 is an enlarged sectional view of the vicinity of the filtering means.

FIG. 8 is a perspective view showing an example of a conventional semiconductor wafer cassette storage container.

! , l0115 ... Semiconductor wafer cassette storage container, 2 ... Case body, 3 ... Bottom plate, 4
・Semiconductor wafer, 11. Sealing part (E, 12... Elastic deformation part (differential pressure adjustment means), casing, gripping part.

Claims (1)

[Scope of Claims] 1) A sealable semiconductor wafer cassette storage container for storing semiconductor wafer cassettes, which is provided with differential pressure adjusting means for adjusting the differential pressure between the inside of the semiconductor wafer cassette storage container and outside air. A semiconductor wafer cassette storage container characterized by: 2) A semiconductor wafer cassette storage container that is a sealable semiconductor wafer cassette storage container for storing semiconductor wafer cassettes, and is characterized in that it is provided with a filtration means that communicates with the outside air.