JPH0443645A - Method and equipment for coating edge of wafer - Google Patents

Abstract

PURPOSE:To prevent plating metal from attaching on the edge of a wafer, by coating the whole periphery of the edge of a wafer with photoset resin while rotating the wafer, and projecting a light beam on the photoset resin spread on the edge of the wafer. CONSTITUTION:A wafer W is vertically acommodated in the inside of a wafer accommodating basket 20, which is loaded on an equipment main body 10. The wafer is rotated counterclockwise by driving a sending roller 30, and rollers 41, 42 in a coating means 40 for photoset resin are rotated. At the same time, a shutter 41 is opened, and the edge of the wafer W is irradiated with a light beam. In the coating means 40, photoset resin attaching on the roller 41 is buried in a recessed part 42a of the roller 42, and spread on the edge of the wafer W. The photoset resin spread on the edge of the wafer W is irradiated with the light beam from a light source 50, and cured. Thereby plating metal is prevented from attaching on the edge of the wafer, and the yield of IC chips can be improved.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a wafer 1- on which a collector circuit (IC) is formed.
The present invention relates to a wafer edge coating method and apparatus for coating the edge of a wafer to prevent plating from forming on the edge of the wafer when forming a hang for a bonder to a printed circuit board.

[Prior Art] In order to mount an IC on a printed circuit board, for example, hangs that serve as electrode connection parts are formed on each IC chip in advance, and after the wafer is cut into each IC chip, the bumps and hangs are formed on each IC chip. A method has been adopted in which the leads on the printed circuit board are joined by bonding.

Conventional methods for forming bumps include a vapor deposition method, that is, a method in which a mask is formed on a wafer other than an IC reed portion, and a metal film is vapor-deposited to form a hump.

However, in the case of the vapor deposition method, it was difficult to match the mask to the large '7 wafer, and problems such as mask warping occurred, making it impractical.

Therefore, in recent years, a plating method as shown in FIGS. 5(a) to 5(C) has been developed, and it has become possible to form humps even on large wafers without causing the above-mentioned problems. According to this plating method, the wafer W is placed on a rotating support called a stainer, a solder adhesion prevention film (resist) L is applied to the front surface of the wafer W, and the resist L is also applied to the back surface of the wafer W. After that, the resist L is removed by exposing the IC REEAT part Rft (FIG. 2(a)). Next, the wafer W is subjected to copper plating treatment to form a copper plating layer P on the IC REET part R, and further copper plating is performed. A solder layer S was laminated on top of the layer P (see figure (b)), and then the resist L on one side was removed and the solder layer S was reflowed to form a hump ■ (see figure (b)). c)).

[Problems to be Solved by the Invention] In the conventional plating method described above, resist is applied to both the front and back surfaces of the wafer W, but the end surfaces of the wafer W remain exposed. That is, resist cannot be applied to the end surface of the wafer W while it is placed on the spinner.

However, silicon that forms the wafer and copper have a strong affinity, and if the end surface of the wafer W is left exposed, copper plating will adhere to it.Especially if a similar solder is used for the solder layer, Since the copper plating layer must be formed thickly, the amount of copper plating deposited on the wafer end face also increases. If a large amount of copper plating adheres to the edge of the wafer in this way, irregular cracks or chips may occur from the edge when the wafer is cut in the subsequent process, resulting in a decrease in the yield of produced IC chips. had.

The present invention was made in view of these circumstances.
The purpose of the present invention is to provide a wafer edge coating method that prevents plating from adhering to the wafer edge and improves the yield of IC chips, and a wafer edge coating device suitable for carrying out the method. do.

[Means to solve the problem] 1-Note [In order to achieve the purpose, unreleased +! In the wafer edge coating method (2), without rotating the wafer, a photocurable resin is applied to the entire circumference of the wafer edge, and at the same time, the photocurable resin coated on the wafer edge is There is a method of irradiating the wafer with a light beam, and after performing the above method all around the wafer, the application of the photocurable resin is stopped and the photocurable resin that has already been applied to the edge of the wafer is applied. Another method is to further irradiate the light beam.

In addition, the wafer edge coating device of undeveloped IJI includes a means for rotatably supporting a wafer, a means for rotating the wafer supported by the same means, and a photocurable resin connected to the edge of the rotating wafer. and a means for irradiating light onto the photocurable resin coated on the edge of the wafer.

[Function] With the above-described structure, the present invention can form a photocurable resin layer on the edge of the wafer, and the bond between the plating and the silicon can be broken by the same layer. It will no longer stick to the edges.

The photocurable resin to be used may be one that has a weak affinity with plating and does not dissolve at all in the plating solution, such as purple flash curing resin (trade name: Heartlock).
IT gas chemistry-■. (manufactured by Gyogyo Co., Ltd.)) can be used.

[Example] An example of the present invention will be described below with reference to the drawings.
do.

FIG. 1 is a side cross-sectional view showing an embodiment of the wafer edge coating device of the present invention, FIG. 2 is a partially cutaway front view of a wafer storage hasget, and FIG. 3 is a photocurable resin coating means 41. FIG. 4 is a front view showing the roller portion of the means.

First, embodiments of the apparatus of the present invention will be described with reference to these drawings.

In FIG. 1, reference numeral 10 denotes a box-shaped device main body, and a lid 11 is detachably attached to an opening on the top surface. Device body lO
Inside is a wafer storage basket (wafer support means).
20 mounting frame 12, feed roller (wafer rotation means) 30
, photocurable resin coating means 40. and a light source 50 are provided, respectively. In addition, 13 and 14 have ventilation holes, and in particular, a tip plate 15 is provided below the ventilation hole 13,
External light is prevented from entering the wafer W.

Inside the wafer storage basket 20, partitions 21 are arranged at regular intervals, and a large number of wafers W are stored vertically between these partitions 21 (see FIG. 2).
Further, an opening 22 having a length shorter than the diameter of the wafer W is provided at the bottom, and a portion of the lower part of the wafer W is exposed through this opening 22. Furthermore, a mounting flange 23 is provided on the outer peripheral edge of the upper end of the basket 20, and the flange 23 is placed on the mounting frame 11 and is configured to be loaded into the main body 10 of the apparatus.

The feed roller 30 is provided at a position where the wafer W exposed from the bottom opening 22 of the wafer storage basket 20 loaded in the apparatus main body 10 comes into contact with the wafer W, and the wafer W is slightly lifted. This feed roller 30 is rotationally driven by a drive motor (not shown). Further, the outer peripheral surface of the feed roller 30 is coated with a slip prevention member 31 having a large coefficient of friction, such as soft rubber, which increases the thick friction force between the wafer W that comes into contact with it due to gravity, and prevents the W from reaching the sea urchins. Efforts have been made to rotate it reliably.

As shown in FIG. 3, the photocurable resin application means 40 is provided with first and second rollers 41 and 42, and the rotation shafts 43 and 44 of each roller 41 and 42 are provided with rollers that engage with each other. Gears 45 and 46 are mounted on both ends. Further, a pulley 47 is attached to the rotating shaft 43 of the first roller 41, and is configured to receive driving force from a driver (not shown) via a transmission belt 48. This driving force causes the first roller 41 to rotate, and at the same time, the second roller 42 is also rotationally driven via the gears 45 and 46.

A container 49 filled with photocurable resin is provided below the first roller 41 , and the lower part of the first roller 41 is immersed in the photocurable resin in the container 49 . Further, the second roller 42 has collars 42a, 42a formed at both ends, and these collars 42a, 42a portions are in contact with the first roller 41. I wanted to, color 42a, 42
As shown in FIG. 4, a gap with a constant depth d is formed between the intermediate portion (hereinafter referred to as the fourth portion) 42b sandwiched between the rollers 4 and 41 and the first roller 41.

The photocurable resin is filled in this gap, and while maintaining a constant depth d, it adheres to the E surface of the second roller 42 and rotates. The wafer W is in contact with the circumferential surface of the second roller 42, and is rotationally driven by the feed roller 30 as described above. Here, the rotation of the wafer W by the feed roller 30 and the second roller 4
It is preferable to synchronize the rotation with the second rotation.

Note that the photocurable resin application means 40 is provided on a moving table (not shown), and is movable in the direction of arrow a in FIG.

The light source 50 includes a feed roller 30 and a photocurable resin resin 71+.
In this embodiment, an ultraviolet lamp is used as the light [50]. In addition, a shutter 51 that can be freely opened and closed is provided in front of the light source 50.
A light beam is irradiated onto the edge of the wafer W only when the shutter 51 is open, and the light beam is cut off when the shutter 51 is closed. moreover,
A fixed shutter 52 is also provided between the photocurable resin application means 40 and the light source 50.

! Ii This prevents light from leaking into the cloth means 40.

Next, an embodiment of the wafer edge coating method according to the present invention, which is carried out using the above-mentioned apparatus, will be described.

First, the wafer W is vertically stored inside the wafer storage basket 20, and the basket 20 is loaded into the apparatus main body 10. At this time, both the feed roller 30 and the photocurable resin application means 40 are stopped, and the shutter 51 is kept closed.

Next, the feed roller 30 is driven to rotate the wafer W in the counterclockwise direction in FIG. 1, and the first and second rollers 41 and 42 in the photocurable resin application means 40 are also rotated. At the same time, the shutter 51 is opened to irradiate the edge of the wafer W with a light beam.

Since the feed roller 30 has the anti-slip member 31 on its circumferential surface, it can reliably contact the wafer W and rotate stably even if the wafer W has a notch such as an orientation flat Wo.

The photocurable resin coating means 40 fills the concave portion 42b of the second roller 42 with the photocurable resin adhered to the first roller 41, and always coats the edge of the wafer W in a uniform area ( (See Figure 4), therefore, the amount of application can be controlled accurately, resulting in the minimum amount of application! tj is possible. For this reason.

Photo-curing of the sides of the end face can be carried out smoothly, and since the coating is uniform, there is no adhesion of plating, and furthermore, it is easy to remove the coated ITJ material on the end face after plating is completed. Subsequently, the photocurable resin applied to the edge of the wafer W is irradiated with light from the light source 50 to harden the resin.

The above-described application of the photocurable resin and irradiation of the light beam are continued until a multilayer film of the photocurable resin is formed all around the wafer W. Thereafter, the second roller 42 is separated from the edge of the wafer W by moving the photocurable resin application means 40, and the wafer W is further rotated twice while the light beam remains irradiated. In other words, the previous treatment is not enough to harden the resin attached to the front and back surfaces of the wafer W, so the wafer W is rotated two more times while being irradiated with light to cure the resin sufficiently. ing.

The wafer W whose edges are coated with the photocurable resin in this way has no risk of plating adhering to the edges in the subsequent plating process, and the photocurable resin on the edges is removed from the wafer W by lift-off. removed from

It should be noted that the present invention is not limited to the embodiments described above, and various modifications and variations can be made without changing the gist.

For example, the structure of the apparatus main body and each means is not limited to the above embodiments, and the structure of the apparatus main body and wafer storage basket in particular may be changed as appropriate, taking into account work space and work scale. There's a lot of room for that.

In addition, in the embodiment of the method invention described above, the p! After the wafer was irradiated with the light beam, the wafer was further rotated twice and the light beam was irradiated. The latter operation may be replaced by providing an irradiation box and irradiating the light beam.

[Effects of the Invention] As explained above, the wafer edge coating method described in [1] has the effect of preventing plating from adhering to the wafer edge and improving the yield of IC chips. There is.

Further, according to the wafer edge coating apparatus of the present invention,
-1- The force distribution method can be performed in-cylinder and quickly.

[Brief explanation of drawings]

Fig. 1 is a side cross section L showing an embodiment of the wafer edge coding device of the present invention;
FIG. 4 is a perspective view of the means for coating 4J of i, and FIG. 4 is a front view LA showing the roller portion of the means, and FIG. 5(a). (b) and (e) are cross-sectional views showing the process of forming a hang on a wafer. 10 Apparatus body 11 Mounting frame 20 Wafer storage basket 22: Opening 23/Flange 30: Feed roller 31: Slip prevention member 40: Coating means for photocuring resin

Claims (3)

[Claims] (1) Without rotating the wafer, apply a photocurable resin to the entire circumference of the edge of the wafer, and irradiate the photocurable resin applied to the edge of the wafer with light. Featured wafer edge coating method. (2) without rotating the wafer, applying a photocurable resin to the entire circumference of the edge of the wafer, and irradiating the photocurable resin applied to the edge of the wafer with a beam of light; , after performing the step all around the wafer, stopping the application of the photocurable resin, and further irradiating the photocurable resin already applied to the edge of the wafer with a light beam; A wafer edge coating method featuring: (3) means for rotatably supporting the wafer; means for rotating the wafer supported by the means; means for connecting to the edge of the rotating wafer and applying a photocurable resin; and the edge of the wafer. A wafer edge coating apparatus comprising: means for irradiating a light beam onto a photocurable resin coated on the edge.