JP2000091400A - Wafer storage cassette - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wafer storage cassette which can stably hold even a thin and large diameter wafer, without generating flextures in the center of the wafer and which can prevent crackings or damages of wafers due to their mutual contacts. SOLUTION: A wafer storage cassette is constituted of an opening 5a for carrying wafers in and out and a support section 5b for support wafers. The support section 5b is constituted of support boards 6, which support wafers by the surface including the periphery and the center of gravity of the wafer. Each of the support boards 6 is formed with a holding section insertion region to allow a wafer holding section of a wafer carry-in/out means to be inserted. This cassette is especially suitable for storing thin (300 μm or less) semiconductor wafers after being polished.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wafer storage cassette particularly suitable for storing thin wafers.

[0002]

2. Description of the Related Art Cassette A for accommodating wafers
Conventionally, as shown in FIG. 5, a plurality of receiving grooves B are provided at predetermined intervals on the opposite side surface of a box-shaped main body that opens laterally, and a wafer C is inserted into the receiving grooves B. By supporting, a plurality of wafers C can be accommodated.

[0003]

However, since the conventional cassette A has a structure in which the receiving groove B supports the opposed position of the outer peripheral portion of the wafer C, a small-diameter wafer C having a standard thickness is accommodated. Although there is no particular problem, there is a problem when a large-diameter wafer that has been thinly ground is accommodated. That is, when a relatively thin large-diameter wafer is accommodated, not only does the center portion easily become largely disengaged from the deflection receiving groove B due to its own weight, but also the wafers come into contact with each other to cause cracking or damage.

An object of the present invention is to solve such a conventional problem. Even when a relatively thin large-diameter wafer is accommodated, the center portion can be supported stably without bending, and the wafer can be supported by contact between the wafers. It is an object of the present invention to provide a wafer storage cassette capable of preventing cracking, damage, and the like.

[0005]

As a specific means for attaining this object, the present invention relates to a wafer accommodating cassette for accommodating a wafer, the wafer accommodating cassette having an opening for carrying in and out the wafer. And a supporting portion for supporting the wafer, wherein the supporting portion is a wafer accommodating cassette configured to be supported on a surface including an outer peripheral portion of the wafer and a center of gravity. Further, in this wafer accommodating cassette, the support portion has a holding portion insertion area into which a wafer holding portion of a wafer carrying-in / out means for carrying in / out a wafer can be inserted, and the wafer is a semiconductor wafer. 300 μm means that an extremely thin semiconductor wafer is contained
It is characterized by the following.

[0006]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 shows an example of a wafer accommodating cassette according to the present invention, in which a substantially disk-shaped upper plate 1 and lower plate 2, side plates 3 and 3 erected to face their outer edges, and this side plate A cassette main body 5 having an opening 5a is constituted by a pair of stopper members 4 and 4 erected at an outer edge portion at an intermediate position between the cassette main body 3 and the cassette main body 5.
A supporting portion 5b for supporting a wafer is formed inside the substrate.

Reference numeral 6 denotes a support plate constituting the support portion 5b. A support region 6a for supporting the outer peripheral portion of the wafer and a plane including the center of gravity, and a support plate 6a for the wafer holding portion 7e of the wafer loading / unloading means 7 shown in FIG. A pair of holding part insertion areas 6b into which the tip part can be inserted is formed.

The support plate 6 is inserted from the opening 5a of the cassette body 5, and both sides are received in receiving grooves 3a, 3a provided on the inner side surfaces of the side plates 3, 3, as shown in FIG. The members 4, 4 can be attached by receiving the arc portions at the distal ends in the receiving grooves 4a, 4a provided on the inner surfaces of the members 4, 4, respectively. In this manner, a plurality of support plates 6 are attached to the cassette body 5.
The support portion 5b is configured by being mounted inside the device.

The wafer accommodating cassette according to the present invention is constituted as described above, and for example, a grinding apparatus D as shown in FIG.
Is used in place of the conventional cassette A. A conventional cassette A 'is placed at a position facing the cassette 5 and accommodates a large-diameter semiconductor wafer (a relatively thick one before grinding) which is an object to be ground.

The wafer loading / unloading means 7 is arranged between the cassette 5 and the cassette A '. The wafer loading / unloading means 7 unloads the semiconductor wafer W from the cassette A' and sets a standby area. 8 is conveyed.

The wafer loading / unloading means 7 has a rotating shaft 7b mounted on a base 7a which moves up and down as shown in FIG. 3, and a first arm 7c is mounted on the upper end of the rotating shaft 7b. The second arm 7 is provided at the tip of the first arm 7c.
d is pivotably mounted. Further, a wafer holding portion 7e is similarly rotatably attached to the tip end of the second arm 7d, and a fork-like gripping portion 7f branched into two branches is attached to the tip end of the wafer holding portion 7e. A portion 7g is provided. This gripping part 7f is 180 ° at the base 7h of the wafer holding part 7e.
° It may be formed to be reversible.

When the semiconductor wafer W is carried out, each arm of the wafer carrying-in / out means 7 is turned to insert the holding portion 7f under the semiconductor wafer W, and the semiconductor wafer W is sucked by the suction portion 7g and the holding portion is held. 7f is pulled out from cassette A '.

The semiconductor wafer W conveyed onto the first standby area 8 is positioned by a center positioning member 8a as shown in FIG. Is transported to the chuck table 11 provided on the turntable 10 by the first transporting means 9 provided with, and is suction-held on the chuck table 11.

The semiconductor wafer W sucked and held by the chuck table 11 is positioned below the first grinding means 12 by rotating the turntable 10, and is roughly ground by the rotating grindstone 12a at the lower end. After this rough grinding, it is positioned below the second grinding means 13 and is finish-ground by the rotating grindstone 13a at the lower end. During these grinding operations, grinding water is supplied to the surface of the semiconductor wafer W.

The finish-ground semiconductor wafer W is indexed to a take-out position and is conveyed to the spin cleaning / drying means 14 by the second conveying means 9 '. Here, dirt such as grinding water adhered at the time of grinding is spin-cleaned, spin-dried, and then carried into the support portion 5b of the cassette body 5 by the wafer carrying-in / out means 7.

At the time of loading, the semiconductor wafer W is placed on the support plate 6 as shown in FIG. 4, but the holding portion 7f of the wafer loading / unloading means 7 is moved to the holding portion insertion area 6b of the support plate 6.
The support plate 6 can be supported by a surface including the outer peripheral portion of the semiconductor wafer W and the center of gravity. After placing the semiconductor wafer W on the support plate 6, the wafer loading / unloading means 7 releases the suction of the suction portion 7 g and is pulled out from the cassette body 5.

A semiconductor wafer W having a large diameter (for example, 8 inches) may be ground to a relatively small thickness (300 μm or less), but is stably supported by the support plate 6 having a special shape as described above. . Therefore, the semiconductor wafer W
The central part does not bend significantly due to its own weight.
And the semiconductor wafers W do not come into contact with each other to cause cracking or damage.

Although not shown, the cassette main body 5 according to the present invention can be mounted in place of the conventional cassette A 'in FIG. 5, that is, both can be implemented using the cassette main body 5. .

[0019]

As described above, according to the present invention,
Since the supporting portion in the wafer storage cassette is constituted by a supporting plate that supports the surface including the outer peripheral portion and the center of gravity of the wafer, the center portion does not bend even in the case of a large-diameter semiconductor wafer thinly ground by a grinding device. In addition to the above, excellent effects such as stable support and prevention of cracking and damage due to contact can be obtained.

[Brief description of the drawings]

FIG. 1 is a perspective view of a wafer storage cassette according to the present invention.

FIG. 2 is a schematic cross-sectional view showing a mounting state of a support plate constituting a support portion.

FIG. 3 is a perspective view of a main part showing a wafer loading / unloading unit.

FIG. 4 is an explanatory diagram showing a positional relationship between a wafer holding portion of a wafer carrying-in / out means and a support plate.

FIG. 5 is a perspective view showing an embodiment in which the wafer storage cassette according to the present invention is used in a grinding device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Upper plate 2 ... Lower plate 3 ... Side plate 4 ... Stopper member 5 ... Cassette main body 5a ... Opening 5b ... Support part 6 ... Support plate 7 ... Wafer carrying-in / out means 8 ... Stand-by area 9 ... 1st carrying means 10 ... Turntable 11 ... Chuck table 12 ... First grinding means 13 ... Second grinding means 14 ... Spin cleaning / drying means

Claims (4)

[Claims] A wafer accommodating cassette for accommodating a wafer, the wafer accommodating cassette comprising an opening for carrying in / out a wafer, and a support for supporting the wafer, wherein the support is a wafer holder. A wafer storage cassette configured to be supported by a surface including an outer peripheral portion and a center of gravity. 2. The wafer accommodating cassette according to claim 1, wherein the support section has a holding section insertion area into which a wafer holding section of a wafer loading / unloading means for loading / unloading a wafer can be inserted. 3. The wafer storage cassette according to claim 1, wherein said wafer is a semiconductor wafer, and a relatively thin semiconductor wafer is stored therein. 4. The wafer accommodating cassette according to claim 3, wherein the relatively thin thickness is 300 μm or less.