JP2601131Y2 - Adhesive sheet with separator - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure-sensitive adhesive sheet with a separator which can be adhered to a semiconductor wafer through a smooth pressure-sensitive adhesive surface with good sealing properties.

[0002]

2. Description of the Related Art Conventionally, various types of pressure-sensitive adhesive sheets with a separator in which a pressure-sensitive adhesive surface is easily adhered and coated with a separator have been known. However, in the case of a conventional adhesive sheet, when any of the separators is peeled off and adhered to a semiconductor wafer, and subjected to a back surface polishing process or a dicing process, a cleaning liquid or cutting chips penetrate from an adhesive interface. There was a problem. The intrusion of the cleaning liquid or cutting chips causes a fatal problem such as destruction of the circuit pattern formed on the wafer.

[0003] The present inventors have conducted intensive studies to overcome the above-mentioned problems, and as a result, the problem of infiltration of cleaning liquid and cutting chips is caused by the occurrence of a gap at the bonding interface between the wafer and the adhesive surface. It has been clarified that the occurrence is mainly caused by unevenness of the adhesive surface. Therefore, it is preferable that the adhesive surface of the adhesive sheet that adheres to the semiconductor wafer is smoother to prevent the cleaning liquid and the cutting chips from entering the adhesive interface.

[0004] The invention according to Japanese Utility Model Application No. 1-55030 is as follows.
It is proposed from such a viewpoint. In other words, when the adhesive sheet is wound or stacked with the separator attached, air is taken in between the adhesive sheets to prevent the adhesive sheet, and thus the adhesive surface, from having irregularities. The surface is provided with an emboss for releasing intake air, so that the adhesive surface of the adhesive sheet adhered to the semiconductor wafer is kept smooth.

On the other hand, according to the present invention, in order to prevent a cleaning liquid or cutting debris from intruding from a bonding interface when bonded to a semiconductor wafer, a separator whose adhesive surface is formed or maintained smoothly is bonded. It is intended to propose a pressure-sensitive adhesive sheet.

[0006]

In other words, the present invention provides an embossed surface on one side of an adhesive surface for bonding to a semiconductor wafer.
Surface roughness based on Rmax is 1-3μm on the other side
Providing a separator having a back surface on the entire surface of the adhesive surface to the adhesive surface by peeling easily bond coat through the back surface, an adhesive sheet having separators, characterized in that the smooth surface of the adhesive surface of the Is what you do.

[0007]

By adhesive protective adhesive side in [action] The above separator, excellent surface smoothness of the separator back surface based on sensitive fluidized-adhesive layer by the pressing force at the time the separator adhesion or the like
Point is reflected on the adhesive surface, and a smooth adhesive surface is formed or maintained. As a result, it is possible to provide an adhesive surface that is excellent in close contact sealing and that can prevent intrusion of a cleaning liquid or cutting chips from the bonding interface when bonded to a semiconductor wafer.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The pressure-sensitive adhesive sheet with a separator of the present invention is embossed on one side of the pressure-sensitive adhesive surface for bonding to a semiconductor wafer.
Surface having a surface roughness of 1 to 3 μm based on Rmax
A separator having a back surface on the entire surface of the adhesive surface to the adhesive surface by peeling easily bond coat through the back surface, the surface of the adhesive surface is obtained by a smooth. An example is shown in FIG . 1 is a separator, 2 is an adhesive sheet, 21 is an adhesive layer, and 22 is a supporting base material.

As a separator , embossing is applied to one side.
While having a work surface, the whole surface that adheres to the adhesive surface on the other surface,
Which surface roughness based on Rmax is formed of the back surface of the 1~3μm is used.

The surface to be the outer surface of the separator is an embossed surface as in the example of FIG. When the embossing is performed on one surface of the separator, irregularities based on the embossing may be reflected on the other surface of the separator.
The unevenness of the other surface formed by the reflection is generally smaller than the unevenness provided on the embossed surface.
Even when embossing is performed with a max exceeding 3 μm, the degree of irregularities reflected on the other surface can be reduced to Rmax 3 μm or less. However, in the present invention, the surface roughness of the surface of the separator that adheres to the adhesive surface is reduced. It is preferable that embossing is performed with a Rmax of 3 μm or less, since the smaller the value, the better the smoothness.

A separator having a back surface having a surface roughness based on Rmax of 1 to 3 μm is processed by stretching a film or the like as necessary through a pinch roll formed of a roll having a smooth surface. It can be obtained by a method or the like. The thickness of the separator is usually 10 to 100 μm.

The material forming the separator is not particularly limited, and any of the conventional separator materials can be used. Generally, a plastic sheet made of polypropylene, polyester, polyethylene laminated paper, polycarbonate, polyethylene or a copolymer thereof, triacetate or the like is used. The separator may be surface-treated with an appropriate release agent such as a silicone-based or long-chain alkyl-based, if necessary, to facilitate release from the adhesive surface.

As shown in the drawing, as the pressure-sensitive adhesive sheet 2, a conventional pressure-sensitive adhesive sheet in which a pressure-sensitive adhesive layer 21 is provided on a support base material 22 can be used. The support base material and the pressure-sensitive adhesive for forming the pressure-sensitive adhesive layer are not particularly limited, and any of known materials such as the plastic-based sheet exemplified by the above-described separator, a rubber-based pressure-sensitive adhesive, and an acrylic pressure-sensitive adhesive can be used.

A supporting substrate and an adhesive layer that are preferable for bonding a semiconductor wafer are excellent in water resistance, and a supporting substrate excellent in heat resistance is also preferable. Further, a support base material having a surface having no adhesive layer and roughened into a satin finish is also preferable.
The thickness of the supporting substrate is 5 to 500 μm, and the thickness of the adhesive layer is 1 to
500 μm is common.

The adhesive layer may be provided on one side or both sides of the supporting substrate. When provided on both sides, a separator having a back surface of the Rmax1~3μm the adhesive surface to adhere to at least the semiconductor wafer is adhered.

The present invention of the pressure-sensitive adhesive sheet having the separator, the back surface of the Rmax1~3μm separator can be formed by bonding coated on the adhesive surface of the adhesive sheet, which is wound material or a stack, or a single sheet of The semiconductor wafer can be bonded to the semiconductor wafer in an appropriate form, and the adhesive surface from which the separator has been peeled off can be bonded to the semiconductor wafer to be preferably used for a backside polishing step, a dicing step, and the like.

Example 1 A thickness of 1 μm was formed on one side of a polyvinyl chloride film having a thickness of 80 μm.
A 5 μm acrylic pressure-sensitive adhesive layer was attached to form a pressure-sensitive adhesive sheet, and a separator was bonded to the pressure-sensitive adhesive surface to obtain a pressure-sensitive adhesive sheet with a separator. The bonding surface of the separator is a non-embossed surface having a Rmax of less than 3 μm obtained by treating one surface of a polyester film having a thickness of 25 μm with a silicone release agent.

Example 2 An adhesive sheet with a separator was obtained in the same manner as in Example 1 except that a polyethylene film having a thickness of 60 μm was used instead of the polyvinyl chloride film.

Evaluation Test A dicing sheet was randomly punched from the pressure-sensitive adhesive sheets with separators obtained in Examples 1 and 2 , and a semiconductor wafer having a diameter of about 4 inches was bonded and fixed to the pressure-sensitive adhesive surface from which the separator was peeled off, and then diced. Corner chips were formed. In the above, no intrusion of the cleaning liquid and cutting chips was found at the interface between the wafer and the adhesive surface, and the formed chips were not scattered during cutting.

[0020]

According to the present invention, an adhesive sheet having excellent smoothness of an adhesive surface can be obtained via an adhesive-coated separator.
It can be adhered to the semiconductor wafer with good adhesion and sealing properties through the adhesive surface, and can effectively prevent poor polishing, intrusion of contaminated water and cutting chips, scattering of formed chips, etc. in operations such as backside polishing and dicing of the semiconductor wafer, forming The yield of chips can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view of an embodiment. 1: separator 2: adhesive sheet 21: adhesive layer 22: supporting substrate

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁶ , DB name) C09J 7/00 H01L 21/00

Claims (1)

(57) [Scope of request for utility model registration] To 1. A pressure-sensitive adhesive surface for adhering to the semiconductor wafer surface roughness based on Rmax on the other surface has an embossed surface on one side of the adhesive surface of the back surface of 1~3μm to the adhesive surface the separator having the entire surface is peeled off easily bond coat through the back surface, the pressure-sensitive adhesive sheet having the separator, characterized in that the smooth surface of the adhesive surface.