JPS63134168A - Applying method for wafer adhering wax and device thereof - Google Patents

Abstract

PURPOSE:To apply wax in thin, uniform thickness and prevent it from sticking to a polishing surface as well as to protect a surface other than the polishing surface from abrasive powder, by dropping the liquid wax on the wafer top central part, and spreading it over the whole top surface by centrifugal force. CONSTITUTION:Liquid wax is dropped on the rotational center from the upside of a wafer 6 rotating in the horizontal direction, and it is spread wide over the whole top surface of the wafer by means of centrifugal force whereby the wax can be applied to the top in thin, uniform thickness. Therefore, since thickness of the wax is very thin, when this wafer 6 is made to adhere to a carrier plate, the wax is in no case protruded to the outside from a wax applied surface, thus it can be prevented from sticking to a polishing surface of the wafer 6. On top of that, since the wax is uniformly stuck to the surface to the carrier plate, the surface other than the polishing surface of the wafer 6 is protectable from abrasive powder.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method and apparatus for applying wax for bonding wafers.

[Conventional technology]

Generally, when mirror finishing the surface of a wafer, the wafer is bonded to the end surface of a carrier plate with wax.

Conventionally, in such cases, solid wax was applied to the end face of the 'r-1p rear plate, and then a wafer was pressure-bonded to the end face. However, when the wafer is bonded using this method, wax is also attached to the end surface of the carrier plate where the wafer is not bonded, making it impossible to polish the wafer in this state.
Before polishing the wafer, the wax in the area was removed with a specific solvent. However, when the wax is removed in this way, some of the wax between the wafer and the carrier plate is also removed by the organic solvent, and during the subsequent polishing operation, the wax bonding surface of the wafer is polished. There was a problem in that the agent (alkaline solution) adhered to the product.

Therefore, in order to solve this problem, a method was devised in which wax was applied to the wafer and the wafer was bonded to the broken rear plate under pressure. In this case, methods for applying wax to the wafer include a spray method in which liquid wax is sprayed onto the upper surface of the wafer, and a dipping method in which the lower surface of the wafer is immersed in molten wax.

[Problem that the invention seeks to solve]

However, when wax is applied to a wafer by the above spray method, it is difficult to make the thickness of the wax uniform on the wafer surface. For this reason, when a wafer coated with wax is bonded to a carrier plate using this method, the wax bonding surface of the wafer may be damaged during the wafer polishing process, similar to when wax is coated on the edge of the carrier plate. There is a problem in that the abrasive (alkaline solution) may adhere and corrode the wax adhesive surface.

Further, when wax is applied to a wafer by the above-mentioned dipping method, it is difficult to reduce the thickness of the wax on the wafer surface. Therefore, when using a wafer coated with wax using this method, when the wafer is bonded to a carrier plate under pressure, the wax protrudes from the wax coated surface of the wafer, and this wax makes the wafer effective. There was a problem that it could not be polished.

[Means for solving problems]

The method of applying wax for wafer adhesion of the present invention is to rotate the wafer horizontally with the wafer held horizontally, drop liquid wax from above the wafer onto the center of the upper surface of the wafer, and remove the dropped wax. Wax is applied to the top surface of the wafer by stretching the wax onto the top surface of the wafer using centrifugal force.

The equipment used to carry out the above coating method includes a rotary drive source with a rotating shaft oriented vertically, a vacuum chuck that is attached to the top of the rotating shaft and on which the wafer is mounted horizontally, and a rotating A fixed amount dispensing device is provided above the shaft so that the discharging port is positioned on an extension of the rotating shaft with the discharging port facing downward, and drips liquid wax toward the wafer. That's what happens.

〔Example〕

FIGS. 1 and 2 are diagrams showing an embodiment of a wafer bonding wax coating apparatus of the present invention.

In these figures, reference numeral 1 denotes a rotary drive source, 2 a vacuum chuck attached to the rotary drive source 1, and 3 a metering dispenser disposed above the vacuum chuck 2.

The rotational drive source 1 includes a drive source main body 1a and a drive source main body 1.
The rotating shaft 1b is mounted on the frame 4 and extends in one direction.The rotating shaft 1b is mounted on the frame 4 with the rotating shaft 1b facing vertically upward. This pedestal 4 is formed with an arm portion 4a extending horizontally at an upper portion thereof, and a hole 4b penetrating vertically is formed in this arm portion 4a. The rotary drive source 1 is configured such that the L portion of the drive source main body 1a is fixed to the lower surface of the arm portion 4a with the rotating shaft 1b fitted into the height 4b from below. Further, a hole 1C is formed in the rotating shaft 1b, extending downward from the central portion of the tip and penetrating toward the hole 4c formed in the arm portion 4a of the pedestal 4. A groove 4G continuous in the circumferential direction is provided on the inner peripheral surface of the hole 4c.
is formed, and a vacuum 8!5 is connected to this groove 4C.

The vacuum chuck 2 has a disk-shaped mounting part 2b formed at one end of a cylindrical part 2a, and a hole 2c penetrating from the one end into the cylindrical part 2a in the center of the mounting part 2b. , is attached to the rotary drive source 1 by fitting the rotating shaft 1b into the inside of the cylindrical portion 2a. Above mounting part 2
The wafer 6 is horizontally mounted on the upper surface by sucking air from the hole 2b using the vacuum source 5. A cylindrical cover 7 is disposed on the side of the mounting section 2c to prevent liquid wax dropped on the upper surface of the wafer 6 from scattering to the side of the wafer 6 due to centrifugal force. A heater 8 is arranged below the wafer 6 to prevent the liquid wax dropped onto the upper surface of the wafer 6 from curing.

The quantitative dispenser 3 includes a pipe 3a for supplying liquid wax, a valve 3b attached to one end of the pipe 3a, and a valve 3.
The discharge port of the nozzle 3C is arranged above the rotating shaft 1b so that the discharge port of the nozzle 3C is located on an extension of the rotating shaft 1b. The valve 3b is for supplying a fixed amount of the wax from the pipe 3a to the nozzle 3C, and the nozzle 3C is for dropping the wax from above toward the center of rotation of the wafer 6.

When using a coating apparatus having such a configuration, first, use a centering device (not shown) to align the center of the wafer 3 with the center of the mounting portion 2c of the vacuum chuck 2, and in this state, place the wafer 6 on the vacuum chuck 2. Attach to. Next, this wafer 6 is horizontally rotated together with the vacuum chuck 2 by the rotational drive source 1. Then, a fixed amount of liquid wax is dripped onto the upper surface of the wafer 6 in such a state from the metering dispenser 3 disposed above the wafer 6.

In this way, the wax spreads laterally at the center of the upper surface of the wafer 6 due to centrifugal force, and the wax is applied to the entire upper surface of the wafer 6.

According to this coating method, a constant drop of liquid wax is dropped onto the rotation center of the wafer 6 from above the horizontally rotating wafer 6, and the dropped wax is spread over the entire upper surface of the wafer 6 by centrifugal force. Therefore, the wax can be applied to the upper surface of the wafer 6 in a thin and uniform thickness. Therefore, since the wax is thin in the wafer 6 coated with wax by this coating method, when the wafer 6 is bonded to the carrier plate, the wax is removed from the wax-coated surface of the wafer 6. This prevents the wax from protruding to the outside and prevents the wax from adhering to the polished surface of the wafer 6. Moreover, according to this wafer 6, wax is evenly adhered to the surface bonded to the carrier plate, so that the polishing of the wafer 6 in the subsequent process can be carried out smoothly. can be protected from abrasives.

Furthermore, according to the coating device described above, since the cylindrical cover 7 is arranged on the side of the mounting portion 2C of the vacuum chuck 2,
When dropping liquid wax from above onto the rotating wafer 6 mounted on the vacuum chuck 2, it is possible to prevent the wax from scattering laterally from the peripheral edge of the wafer 6.

Furthermore, according to this coating device, since the heater 8 is disposed below the mounting portion 2C of the vacuum chuck 2, the liquid wax dropped on the top surface of the wafer 6 is hardened before it spreads over the entire top surface of the wafer 6. This can be prevented.

Note that this coating device has a filter 8 disposed below the mounting portion 2C, but when a volatile wax with a low curing temperature is used as the wax for coating the wafer 6, In this case, the heater 8 may not be provided.

〔Effect of the invention〕

According to the method of applying wax for wafer adhesion of the present invention,
Liquid wax is dropped from above the horizontally rotating wafer onto the center of rotation of the wafer, and the dropped wax is spread over the entire top surface of the wafer by centrifugal force, so that the wax is thinly and evenly spread over the top surface of the wafer. It can be applied to a certain thickness. Therefore, when a wafer is coated with wax using this coating method, the wax is thin, so when the wafer is bonded to a carrier plate, the wax protrudes outward from the waxed surface of the wafer. This prevents the wax from adhering to the polished surface of the wafer 6. However, according to this wafer, the wax is evenly adhered to the surface bonded to the carrier bullet, so that the polishing of the wafer in the subsequent process can be carried out smoothly, and the polished surface of the wafer can be smoothly polished. Other surfaces can be protected from abrasives.

Further, according to the wafer bonding wax applicator of the present invention, there is provided a rotary drive source, a vacuum chuck mounted above the rotary drive source to mount the wafer, and a vacuum chuck disposed above the vacuum chuck. Since the apparatus is equipped with a metering dispenser for discharging liquid wax, the above coating method can be easily carried out, and the effects produced by carrying out the above coating method can be reliably realized.

[Brief explanation of the drawing]

1 and 2 are views showing an embodiment of the wafer@wearing wax coating apparatus of the present invention, in which FIG. 1 is a sectional view of the wafer bonding wax coating apparatus, and FIG. Figure A-
It is a cross-sectional view taken along line A. DESCRIPTION OF SYMBOLS 1...Rotation drive source, 1b...Rotation shaft, 2...Vacuum chuck, 3...Quantitative dispenser, 6...Wafer .

Claims (2)

[Claims] (1) In a wafer bonding wax coating method in which wax for bonding the wafer to a carrier plate is applied to the upper surface of the wafer, the wafer is rotated horizontally with the wafer held horizontally, and A method for applying wax for bonding wafers, which comprises dropping liquid wax onto the center of the upper surface of the wafer, and spreading the dropped wax over the entire upper surface of the wafer by centrifugal force. (2) A wafer bonding wax coating device for coating the upper surface of the wafer with wax for bonding the wafer to the carrier plate, including a rotational drive source with a rotating shaft oriented in the vertical direction, and a rotating drive source mounted on the top of the rotating shaft; A vacuum chuck on which the wafer is mounted horizontally on its upper surface, and a vacuum chuck arranged above the rotation shaft with the discharge port facing downward and positioned on an extension of the rotation shaft, and the wafer 1. A wax coating device for bonding wafers, comprising: a metering dispenser for dropping liquid wax onto a wafer.