JPH06321371A - Separating method and device for wafer - Google Patents

Abstract

PURPOSE:To automate the separation of wafers from a laminated body made by stacking multiple wafers in close contact condition. CONSTITUTION:When a wafer 1 of the uppermost layer is separated from a laminated body 2 made by closely stacking multiple sheet wafers 1, and cut one by one in sequence, two attracting pads 3a and 3b are positioned on the upper surface of the laminated body 2 of the wafer 1 movably in vertical direction, and two peripheral parts of the wafer 1 of the uppermost layer are attracted vacuously. Then one attracting pad 3a is raised slightly and tilted to deflect the peripheral part of the wafer 1 held by the attracting pad 3a and form a clearance (m) between the wafers, and air enters through the clearance (m) to release the close contact condition of the wafers. After that, both attracting pads 3a and 3b are raised to separate the wafer 1 of the uppermost layer only and cut securely one by one.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for separating a wafer, and more particularly, it is used for manufacturing a semiconductor device,
The present invention relates to a separation method and apparatus for separating wafers from a laminated body in which a large number of thin plate-shaped wafers are stacked in close contact and sequentially cutting the wafers one by one.

[0002]

2. Description of the Related Art In the manufacture of semiconductor devices, a silicon single crystal ingot is sliced to form a thin plate wafer,
Then, the wafers are separated from the stacked body in which a large number of thin plate-shaped wafers are stacked in close contact with each other, and the wafers are sequentially cut out one by one and supplied to the subsequent process.

As shown in FIG. 3, the wafer is separated by preparing a laminated body (2) in which a large number of thin plate-shaped wafers (1) are stacked in close contact with each other, and the uppermost wafer of the laminated body (2) ( It is done from 1). At this time, the processing surface of the wafer (1) faces downward. Conventionally, an operator inserts a knife edge or tweezers from the side between the uppermost wafer (1) and the lower wafer (1) as shown by the arrow in the figure, so that the uppermost wafer (1) The wafer (1) was separated so that it was forcibly peeled off and cut out one by one.

[0004]

By the way, the surface of the above-mentioned wafer (1) is in a very smooth state, and when these wafers (1) are stacked, each wafer (1) is firmly adhered to each other. Has become. Therefore, it is very difficult for an operator to peel the wafer (1) by inserting the knife edge or tweezers between the wafers (1) by hand as in the past, and the wafer (1) will be damaged if forced. There is a problem that such manual work requires skill, takes time, and is inefficient in work.

Therefore, the present invention has been proposed in view of the above problems, and an object thereof is to automate the separation of wafers from a laminated body in which a large number of wafers are stacked in a close contact state.

[0006]

As a technical means for achieving the above object, the method of the present invention is to sequentially separate the uppermost wafer from a laminated body in which a large number of thin plate-shaped wafers are stacked in close contact with each other. When cutting out one by one, the peripheral edge of the uppermost wafer is adsorbed from above and locally deflected by a minute amount. In the above method, it is preferable that the uppermost wafer is sucked and locally deflected by a small amount, and then air blown toward the gap formed between the wafer and the remaining stacked body.

Further, in the apparatus of the present invention, the uppermost wafer is separated and sequentially cut out one by one from the laminated body in which a large number of thin plate-shaped wafers are stacked in close contact with each other. It is characterized in that it has an adsorption pad that is adsorbed from above and locally deflected by a minute amount. It is also possible to use, as the suction pad, a suction surface having a convex curved surface that sucks almost the entire surface of the wafer.

[0008]

In the present invention, the peripheral edge of the uppermost wafer is adsorbed from above and locally deflected by a minute amount to form a gap between the wafer and the wafer below it.
When air enters between the upper and lower wafers through the gap, the close contact state is released and the uppermost wafer can be easily separated.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a wafer separating method and apparatus according to the present invention will be described with reference to FIGS. The same parts as those in FIG. 3 are designated by the same reference numerals, and the duplicated description will be omitted.

The feature of the present invention is that the uppermost wafer (1) is separated from the laminated body (2) in which a large number of thin plate-shaped wafers (1) are stacked in close contact with each other, and the uppermost wafer (1) is sequentially cut out one by one. The peripheral edge of the wafer (1) is sucked from above and locally deflected by a minute amount.

Specifically, first, as shown in FIG. 1A, two suction pads (3a) (3b) separated by a predetermined distance are provided above the stacked body (2) of the wafer (1). The upper and lower wafers (1) are vacuum-sucked by the suction pads (3a) and (3b) so that they are vertically movable. Here, if the wafer (1) is attempted to be lifted by the suction pads (3a) and (3b) as it is, only the uppermost wafer (1) can be separated because the wafer (1) is in a close contact state. Have difficulty.

Therefore, as shown in FIG. 1B, one suction pad (3a) is slightly raised and tilted so that the peripheral portion of the wafer (1) held by the suction pad (3a) is moved. Bend. Here, as the bending amount of the wafer (1), for example, a 3-inch wafer (1) having a thickness of 350 μm can be separated only by raising its peripheral portion by about 2 mm.

As a result, a gap (m) is formed between the uppermost wafer (1) and the lower wafer (1) at that position, and the wafers (1) above and below the gap (m) are formed. Air enters between them and the close contact is released. As a result, by raising both suction pads (3a) and (3b) as shown in FIG. 1 (c), only the uppermost wafer (1) can be separated and only one wafer can be reliably cut out.

In the above-described embodiment, two suction pads (3a) and (3b) are used, one of the suction pads (3a) bends the wafer (1), and then both suction pads (3a) and (3b) are bent. Although the wafer (1) is lifted and separated in (3a) and (3b), the other suction pad (3b) does not participate in bending the wafer (1), so that the suction pad (3b) Instead, use a simple holding pad, and after bending the wafer (1), release the holding by the holding pad and then raise only one suction pad (3a) to separate. Good. Since the wafer (1) is thus lightweight, it can be held by only one suction pad (3a).

Further, the present invention is not limited to the above embodiment, and it is possible to use, for example, one suction pad (4) as shown in FIG. The suction pad (4) is made of a sponge-like member having a surface having a convex curved surface (for example, a cylindrical curved surface) and having a suction surface (5).

When this suction pad (4) is used, as shown in FIG. 2 (a), the suction pad (4) is tilted in one direction and a part of the suction surface (5) is laminated. By abutting against the peripheral edge of the uppermost wafer (1) of (2), that portion of the wafer (1) is adsorbed and held, and the adsorption pad (4) is tilted in the direction opposite to the tilting direction. , Fig. 2
As shown in (b), the suction pad (4) is placed in a horizontal posture. As a result, the peripheral portion of the uppermost wafer (1) sucked by a part of the suction surface (5) of the suction pad (4) is bent, and is positioned below the peripheral edge portion as in the above-described embodiments. A gap (m) is formed between the wafer (1) and air is introduced from the gap (m) between the upper and lower wafers (1) to release the close contact state. Then, as shown in FIG. 2C, when the suction pad (4) is further tilted in the same direction, only the uppermost wafer (1) is sucked and separated along the entire suction surface (5). However, only one piece can be cut out surely. Here, the wafer (1) is bent along the suction surface (5) of the suction pad (4), but such a degree of bending does not adversely affect the wafer (1) itself.

The state shown in FIGS. 1 (b) and 2 (b), that is, the peripheral portion of the uppermost wafer (1) is bent so that the wafer (1) positioned below the wafer (1) is bent. Gap (m)
When the air is blown toward the gap (m) at the time of forming, the contact state between the uppermost wafer (1) and the lower wafer (1) is further surely released.

[0018]

EFFECTS OF THE INVENTION According to the present invention, it is possible to reliably separate and cut wafers one by one without damaging the wafers from a stacked body in which a large number of thin plate-shaped wafers are stacked in close contact with each other. Not only can you realize the automation of, but also the work time can be shortened and the index can be greatly improved.

[Brief description of drawings]

FIG. 1 is an explanatory view showing an embodiment of a wafer separating method and apparatus according to the present invention.

FIG. 2 is an explanatory diagram showing another embodiment of the present invention.

FIG. 3 is an explanatory view showing a conventional wafer separating method and apparatus.

[Explanation of symbols]

 1 Wafer 2 Laminate 3a, 3b Suction pad 4 Suction pad 5 Suction surface m Gap

Claims (4)

[Claims] 1. When separating the uppermost wafer from a laminated body in which a large number of thin plate-shaped wafers are stacked in close contact and sequentially cutting out the wafers one by one, the peripheral edge of the uppermost wafer is adsorbed from above and locally. A method for separating a wafer, which is characterized in that it is flexed by a very small amount. 2. The uppermost wafer is sucked and locally deflected by a small amount, and then air blown toward a gap formed between the wafer and the remaining laminated body. The method for separating a wafer according to claim 1. 3. A laminate in which a large number of thin plate-shaped wafers are stacked in close contact with each other, and the uppermost wafer is separated and sequentially cut out one by one, and the peripheral edge of the uppermost wafer is adsorbed from above. A wafer separating apparatus having a suction pad that locally bends a small amount. 4. The wafer separating apparatus according to claim 3, wherein the suction pad has a convex curved suction surface for sucking substantially the entire surface of the wafer.