JPH0620442U - Adhesive sheet for semiconductor wafer - Google Patents

Abstract

(57) [Abstract] [Purpose] Used as a sheet for dicing a semiconductor wafer, which includes a substrate and an adhesive layer. [Structure] Preventing contamination of the working environment in the processing process by applying an antistatic agent to the surface of the base material 1 side that is not coated with an adhesive or using a base material in which an antistatic agent has been kneaded in advance. Improves scale and expandability. If the antistatic agent is applied to the surface of the release paper opposite to the release-treated surface, the residual static electricity can be completely removed.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a semiconductor wafer dicing sheet having a base material and an adhesive layer.

[0002]

[Prior art]

 Conventionally, in the semiconductor wafer dicing process, for example, a semiconductor wafer is processed through a series of processes such as dicing, cleaning, drying, expanding, pickup, and mounting.In that case, an adhesive sheet is attached to the semiconductor wafer. These steps are allowed to pass through as they are. For that purpose, the adhesive sheet is preliminarily pre-molded with release paper, which is called a release paper, to protect the adhesive surface, and when the sheet is attached to a wafer, it is peeled off from the release paper before use.

As a pressure-sensitive adhesive sheet used in such a semiconductor wafer dicing process, conventionally, a base material such as polyvinyl chloride, polyethylene, polypropylene, polyester film, EVA film, etc. has been used. An acrylic ester polymer adhesive is provided on the top of the film, and a polyester or polypropylene siliconized film has been used as a protective film for the adhesive layer.

However, each of these plastic materials has a surface resistance value of 10 ¹³ to 10 ¹⁶ Ω or more, and if a plurality of laminated plastic films are peeled off from each other like the materials used in this field. It is clear that static electricity is generated, and the generated static electricity has a high surface resistance value and will accumulate without being discharged.

[0005]

[Problems to be solved by the device]

 As mentioned above, when the release paper is peeled off, static electricity is inevitably generated.Therefore, it adversely affects the target semiconductor, and dust generated in the surrounding area, dust particles, or dicing. By adsorbing cutting powder, it causes a phenomenon that disturbs the work environment and pollutes, and has developed into an event that has unexpected problems as an ultra-precision industry.

As a general method for solving such a problem, there is a corona discharge conventionally known as an air ionization method, or a method of ionizing and removing the air in the vicinity by an α ray. However, it is difficult to obtain a constant effect depending on the distance from the device, the range of use is limited, and the device is expensive, so it cannot be a desirable method for this purpose.

Further, there is also a method in which a conductive fiber or a metal thin wire in the shape of a brush, which is called a static elimination bar, is used to bring it close to the charged body to discharge. This type is relatively inexpensive and can be expected to have some effect, but it is not sufficient. Moreover, as long as fibers are used, it is unavoidable that the fibers become a source of dust, and therefore this method is not preferable either.

[0008] In addition to the above, there is another particular problem regarding the generation of static electricity during the dicing process. In this process, the blade that cuts the wafer is cooled and the cutting powder is washed away.Therefore, a method in which a large amount of ultrapure water is pressurized and sprayed is used. Since the water used is free of impurities and ions and has high electrical insulation, discharge is hindered and charging is allowed. This phenomenon could not be removed by the two conventional methods mentioned above.

The present invention has been made in view of the above-mentioned problems that have occurred in connection with the recent technology. The purpose of the present invention is to remove release paper in the process of attaching a sheet to a wafer. (EN) A pressure-sensitive adhesive sheet having an excellent property of discharging static electricity generated in the above and static electricity generated in a dicing process.

[0010]

[Means for Solving the Problems] In order to achieve the above object, in the present invention, the generation of static electricity is significantly reduced by applying an antistatic treatment to another surface of the adhesive-coated base material of the adhesive sheet. Focusing on the fact that an excellent discharge effect is also obtained, we were able to find a clue to solving the problem. In order to use this result more effectively, we tried a method of directly kneading into the base material, and further applying a direct antistatic treatment to the release paper, and it was confirmed that it could be put into practical use.

As the antistatic treatment agent used in the present invention, a surfactant and a conductive substance are effective. For example, Elegan 264-A Electol 500 (manufactured by NOF Corporation), Chemistat 1000, 2500 ( Sanyo Kasei Co., Ltd., fatty acid dimethylethyl ammonium sulfate, Registered PE (Daiichi Kogyo Seiyaku Co., Ltd.), Leostat GS-90 (Lion Co., Ltd.), Electrostripers AC, EA (Kao ( Commercially available antistatic agents such as YUKA-ST (produced by Mitsubishi Yuka Co., Ltd.) and the like. The present invention will be described below based on embodiments.

[0012]

Example 1 FIG. 1 is a schematic cross-sectional view of the pressure-sensitive adhesive sheet of the present invention in which an antistatic treatment layer is provided on a support.

A pressure-sensitive adhesive layer 2 is provided on one surface of the base material 1, and the pressure-sensitive adhesive coated surface is covered and protected by a release paper 3 until just before use. The antistatic treatment layer 4 is provided on one surface of the base material 1 different from the surface having the adhesive layer 2. In this example, PVC was used as the base material, and electrostriper AC (manufactured by Kao Corporation) was applied and dried on one surface of the base material with a gravure coater to form an antistatic treatment layer 4. Next, a UV-curable pressure-sensitive adhesive was applied to one side of the substrate 1 other than the side having the antistatic layer to form a pressure-sensitive adhesive layer 2 with a thickness of 10 μm. For the pressure-sensitive adhesive layer 2, a silicone release-treated polyester film was laminated as a release paper 3 to form a pressure-sensitive adhesive protective film, and a pressure-sensitive adhesive tape for wafer dicing was obtained. When this tape was used as a trial in the attaching step and the dicing step, the remarkable effect that the charge amount of 50 kV in the past was reduced to almost 0 kV was obtained. Also, in the dicing process, there was no inconvenience that cutting powder adhered to the tape as compared with the conventional one. Actually, the antistatic surface and the adhesive surface should be charged to either + or +, but the charge on the adhesive surface seems to be discharged by the effect of the antistatic layer on the opposite surface.

Further, by applying the antistatic agent to the surface of the base material, the frictional resistance of the surface is reduced, and it is possible to obtain an initially unexpected advantage that it becomes easy to expand in the expanding step which is the next step. .

[0015]

[Embodiment 2] FIG. 2 is a schematic cross-sectional view of an adhesive sheet of the present invention in which an antistatic agent is directly kneaded into a substrate 1 '. In this example, a PVC film was used as a substrate, and an electrostriper EA (manufactured by Kao Corporation) was kneaded as an additive as an antistatic agent when the substrate film was molded. A pressure-sensitive adhesive layer was formed in the same manner as in 1. and a polyester film subjected to silicone release treatment was stuck as release paper 3 to form a pressure-sensitive adhesive protective film to obtain a pressure-sensitive adhesive tape for wafer dicing. Also in this case, as in Example 1, a remarkable effect in reducing the charge amount was obtained.

In this example, the effect can be obtained by bleeding the antistatic agent on the surface of the PVC film, but by bleeding a little on the pressure-sensitive adhesive surface through the pressure-sensitive adhesive layer, more The effect of is obtained. The bleeding did not affect the physical properties.

[0017]

[Embodiment 3] FIG. 3 is a schematic cross-sectional view in the case where an antistatic treatment layer is provided on a release paper of an adhesive sheet of the present invention. In this method, in addition to the treatment of the base material 1 constituting the sheet used for wafers, the antistatic treatment layer 5 is also provided on the release paper 3 which is discarded at the time of use. In this example, in a tape prepared by the same method as in Example 1, an electrostriper AC (manufactured by Kao Corporation) was applied uniformly on the surface of the release film opposite to the surface treated with silicone by a gravure coater. Then, the dried product was used in the attaching step and the dicing step as in Example 1. In Example 1, the release film was slightly charged as compared with the case where the base material was treated, but in this Example, such charging was not observed at all. Therefore, an extremely large effect was obtained in addition to the effect of treating the substrate side.

[0018]

[Effect of device]

 Since the present invention is configured as described above, it has the following effects.

In the pressure-sensitive adhesive sheet for wafer sticking according to claim 1, by applying an antistatic agent to one surface of the base material coated with the adhesive agent, it is not only the antistatic treated surface but also the opposite surface. The electric charges on the adhesive surface are also discharged, and it is possible to suppress the induction of contamination phenomena in the work environment due to adsorption of dust, fine particles of dust, and cutting powder generated during dicing. Further, the application of the antistatic agent has an advantage that the friction resistance of the surface of the base material is reduced in the expanding step and the expanding is facilitated.

In the pressure-sensitive adhesive sheet for wafer sticking according to claim 2, by using a sheet in which an antistatic agent is kneaded in advance in a substrate, the antistatic agent not only bleeds onto the surface of the substrate film, but also the adhesive agent By bleeding through the layer and bleeding a little on the pressure-sensitive adhesive surface, a further antistatic effect than that of claim 1 is obtained without affecting the physical properties itself, and it is possible to suppress the induction of the contamination phenomenon of the work environment as in the preceding paragraph.

In the pressure-sensitive adhesive sheet for wafer sticking according to claim 3, the release film is formed by applying an antistatic agent on the surface of the release paper opposite to the release-treated surface, in addition to performing the charging treatment on the base material. It is possible to completely remove the static electricity remaining on the substrate, and it is possible to obtain an extremely large effect in combination with the effect of treating the base material side, and the induction suppression of the contamination phenomenon of the work environment is perfect. become.

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing an example of the structure of the pressure-sensitive adhesive sheet according to claim 1 of the present invention.

FIG. 2 is a schematic cross-sectional view showing an example of the structure of the pressure-sensitive adhesive sheet according to claim 2 of the utility model registration claim of the present invention.

FIG. 3 is a schematic sectional view showing an example of the structure of the pressure-sensitive adhesive sheet according to claim 3 of the present invention.

[Explanation of symbols]

 1, 1'Substrate 2 Adhesive layer 3 Release paper 4 Antistatic treatment layer 5 Antistatic treatment layer

Claims (3)

[Scope of utility model registration request] 1. A wafer-adhesive pressure-sensitive adhesive sheet comprising a base material coated with a pressure-sensitive adhesive layer, characterized in that an antistatic agent is applied to one side of the base material coated with the pressure-sensitive adhesive. Adhesive sheet for wafer sticking. 2. A wafer sticking pressure-sensitive adhesive sheet comprising a base material and a pressure-sensitive adhesive layer applied on the surface of the base material, wherein a sheet in which an antistatic agent is kneaded in advance is used. . 3. A release paper, which is used together with a pressure-sensitive adhesive sheet for wafer sticking, comprising a base material surface coated with a pressure-sensitive adhesive layer to protect the pressure-sensitive adhesive surface until just before use, and is opposite to the release-treated surface of the release paper. An adhesive sheet for wafer sticking, characterized in that an antistatic agent is applied to the surface.