JP2000331968A - Wafer protection tape - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wafer protection tape which can prevent damages to a wafer, when the wafer is worked or transported, and, in addition, can be handles easily when the wafer is transferred. SOLUTION: A wafer protection tape T is stuck to one surface of a wafer W, when the other surface of the wafer W is worked with a planarizing device and is composed of a flexible first sheet B and a second sheet D having elastic strength. The recessed and projected sections (x) formed on the surface of the wafer W are absorbed by the flexible first sheet B and the warping of the wafer caused by the own-weight of the wafer W is held by means of the second sheet D.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wafer protection tape, and more particularly, to a wafer protection tape that is adhered to the front surface of a wafer when processing the back surface of the wafer with a plane processing apparatus.

[0002]

2. Description of the Related Art A plane processing apparatus such as a plane grinding apparatus suction-holds the front surface of a wafer with a chuck table and grinds the back surface of the wafer with a grindstone. For this reason, the circuit formed on the front surface side of the wafer may be damaged or stained during processing. Therefore, when processing a wafer with a plane processing apparatus, the wafer is processed by attaching a protective tape to the surface.

As a conventional protective tape, as shown in FIG. 3, an adhesive 2 is applied to a sheet 1 formed of an elastic material such as polyolefin. This is because, by using the sheet 1 formed of an elastic material, irregularities (pumps and the like) formed on the device surface of the wafer W
This is intended to prevent local stress concentration at the time of processing and to prevent cracking and chipping occurring in the wafer.

[0004]

However, since the sheet 1 formed of an elastic material is deformed together with the wafer W, the wafer is apt to be warped due to the influence of its own weight, etc. It has the disadvantage of being extremely inconvenient. As shown in FIG. 4, in order to solve such a drawback, there is a protective tape in which an adhesive 4 is applied to a sheet 3 having a certain degree of strength mixed with glass fibers or the like. The irregularities cannot be absorbed, and the irregularities are transferred to the rear surface during the processing of the rear surface, so that stress concentration occurs at that portion, so that the wafer W tends to be cracked or chipped.

The present invention has been made in view of such circumstances, and has as its object to provide a wafer protection tape that prevents damage to a wafer during processing and transport and that is easy to handle during transport. I do.

[0006]

In order to achieve the above object, the present invention provides a wafer protection tape which is adhered to the other surface of a wafer when one surface of the wafer is processed by a plane processing apparatus. A first sheet that is adhered to the other surface of the wafer, deforms in accordance with the irregularities formed on the wafer, and has an elastic force capable of absorbing the irregularities, and is adhered to the first sheet; And a second sheet having a strength capable of preventing warpage due to its own weight.

According to the present invention, the wafer protection tape comprises:
It is composed of two sheets, a first sheet and a second sheet. The unevenness formed on the wafer is absorbed by the first sheet having elasticity. As a result, local stress concentration at the time of processing can be avoided, and cracks and chips generated in the wafer can be prevented. Further, since the second sheet having strength is attached to the first sheet, the warpage of the wafer due to its own weight can be prevented. This facilitates handling of the wafer during transfer.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a wafer protection tape according to the present invention will be described below in detail with reference to the accompanying drawings. The wafer protection tape according to the present invention is affixed to the front surface of a wafer in order to protect a circuit formed on the front surface of the wafer when the back surface of the wafer is processed by the plane processing apparatus. Therefore, first, an outline of a surface grinding apparatus using the wafer protection tape according to the present invention will be described.

FIG. 1 is a perspective view showing the structure of a surface grinding apparatus 10. As shown in FIG.
The main body 12 is provided with a cassette storage stage 14, an alignment stage 16, a rough grinding station 18, a fine grinding station 20, a polishing station 22, a polishing cloth cleaning stage 23, a polishing cloth dressing stage 27, and a wafer cleaning stage 24. .

On the cassette storage stage 14, two cassettes 26, 26 are set.
A large number of unprocessed wafers W are stored in the wafers 6 and 26. The wafers W stored in the cassette 26 are sucked and held by the hand 31 of the transfer robot 30, taken out of the cassette 26 one by one, and transferred to the alignment stage 16.

[0011] The alignment stage 16
Is a stage for adjusting the position to a predetermined position. The wafer W aligned by the alignment stage 16
Is an empty chuck 32 by the transfer robot 30.
And is sucked and held by the chuck 32.
The chuck 32 is installed on an index table 34. The index table 34 includes four chucks 32, 36, 38, 40 including the chuck 32.
Are arranged at 90 ° intervals on concentric circles. Here, in FIG. 1, the chuck 36 is
, And the wafer W is roughly ground at the rough grinding station 18. The chuck 38 is located at the fine grinding station 20, and the wafer W is finish-ground at the fine grinding station 20. further,
The chuck 40 is located at the polishing station 22, and the wafer W is polished at the polishing station 22.

The thickness of the wafer W sucked and held by the chuck 32 is measured by a measuring gauge (not shown). The wafer W whose thickness has been measured moves to the rough grinding station 18 by rotation of the index table 34, and the back surface of the wafer W is roughly ground by the cup-type grindstone 46 of the rough grinding station 18. Here, the cup-shaped grindstone 46 of the rough grinding station 18 is connected to a motor 48 as shown in FIG.
It is driven to rotate. In addition, the cup-shaped whetstone 46
Is mounted on a grindstone feeder 52 via a support casing 50 of a motor 48, and is driven up and down by the grindstone feeder 52. Then, the wafer W is driven by the grindstone feeder 52 and descends, thereby being pressed against the back surface of the wafer W and roughly grinding the back surface of the wafer W.

The thickness of the wafer W whose back surface has been roughly ground at the rough grinding station 18 is measured by a thickness measuring gauge (not shown). Wafer W with measured thickness
Is moved to the fine grinding station 20 by the rotation of the index table 34, and is finish-ground by the cup-type grindstone 54 of the fine grinding station 20. The configuration of the fine grinding station 20 is substantially the same as the configuration of the coarse grinding station 18.

The thickness of the wafer W whose back surface has been finely ground in the fine grinding station 20 is measured by a thickness measuring gauge (not shown). Wafer W with measured thickness
Is moved to the polishing station 22 by the rotation of the index table 34, is polished by the polishing cloth 56 of the polishing station 22 and the slurry supplied from the polishing cloth 56, and the affected layer generated on the back surface is removed. .

The wafer W polished in the polishing station 22 is transferred to a wafer cleaning stage 24 by a transfer robot (not shown).
And washed. The wafer cleaning stage 24
A stage having a rinsing function and a spin drying function is applied. The wafer W that has been cleaned and dried in the wafer cleaning stage 24 is suction-held by the hand 31 of the robot 30 and stored in a predetermined shelf of the cassette 26.

The surface grinding apparatus 10 is configured as described above. As is apparent from the above description, when the wafer W is processed by the surface grinding device 10, the front surface side is the chuck 3
It is held by suction at 2, 36, 38, and 40, and the back side is processed. For this reason, the circuit formed on the front surface side of the wafer W may be damaged or stained by processing.

Therefore, when processing the wafer W, a wafer protection tape is stuck on the surface thereof to prevent breakage and contamination of circuits and the like formed on the surface. Hereinafter, embodiments of the wafer protection tape according to the present invention will be described. FIG. 2 is a cross-sectional view of a main part showing a configuration of the wafer protection tape T of the present embodiment. As shown in FIG. 1, a wafer protection tape T of the present embodiment includes a first sheet B adhered to the surface of a wafer W via an adhesive A.
And a second sheet D attached to the first sheet B via an adhesive C. The first sheet B is formed of a material having an elastic force capable of deforming in accordance with the irregularities x formed on the wafer W, for example, a polyelefin, and the second sheet D is warped by its own weight. Is formed of a material having a strength capable of preventing the occurrence of a crack, for example, polyethylene terephthalate or the like.

According to the wafer protection tape T of the present embodiment configured as described above, the unevenness x formed on the surface of the wafer W can be absorbed by the first sheet B having an elastic force. Therefore, it is possible to avoid occurrence of local stress concentration at the time of processing the back surface. Further, since the second sheet D having strength is attached to the first sheet B, the warp of the wafer W due to its own weight can be prevented. This facilitates handling of the wafer W during transfer.

Furthermore, by using an elastic body without using a solid material such as glass, the protection tape can be handled continuously, which facilitates automation.

[0020]

As described above, according to the present invention,
The unevenness formed on the wafer can be absorbed, and the warpage of the wafer due to its own weight can be prevented. Thereby, local stress concentration at the time of processing can be avoided, cracking or chipping occurring in the wafer can be prevented, and handling of the wafer at the time of transport becomes easy.

[Brief description of the drawings]

FIG. 1 is a perspective view showing the configuration of a surface grinding device.

FIG. 2 is a cross-sectional view of a main part showing a configuration of a wafer protection tape according to the present invention.

FIG. 3 is a cross-sectional view illustrating a configuration of a conventional wafer protection tape.

FIG. 4 is a cross-sectional view showing a configuration of a conventional wafer protection tape.

[Explanation of symbols]

10: Surface grinding device, W: Wafer, T: Wafer protection tape, A: Adhesive, B: First sheet, C: Adhesive, D
… Second sheet

Claims (1)

[Claims] 1. A wafer protection tape which is attached to the other surface of a wafer when one surface of the wafer is processed by a plane processing device, wherein the tape is attached to the other surface of the wafer and formed on the wafer. A first sheet deformed in accordance with the unevenness and having an elastic force capable of absorbing the unevenness; and a second sheet adhered to the first sheet and having a strength capable of preventing warpage due to the weight of the wafer, A wafer protection tape, comprising: