KR20070033206A - Thin wafer transfer apparatus regardless of warpage appeared on wafer - Google Patents

Abstract

A thin wafer transfer apparatus is provided to transfer stably a thin wafer regardless of the warpage of the wafer by moving a chuck table itself mounted with the wafer to and fro between a wafer rear surface polishing apparatus and a tape mounting unit using a guide rail. A thin wafer transfer apparatus includes a guide rail and a chuck table. The guide rail(185) is installed between a wafer rear surface polishing apparatus and a tape mounting unit. The chuck table transfers a thin wafer through the guide rail.

Description

THIN WAFER TRANSFER APPARATUS REGARDLESS OF WARPAGE APPEARED ON WAFER}

1 is a plan view showing a state in which a wafer is transferred by a wafer transfer apparatus according to the prior art.

2 is a plan view showing a state in which a wafer is transferred by a thin wafer transfer device according to an embodiment of the present invention.

Explanation of symbols on the main parts of the drawings

10, 110: wafer back grinding apparatus

20, 120: turn table

31, 131: waiting table

33, 133: rough grinding table

35, 135: fine grinding table

37, 137: polishing table

43, 143: rough grinder

45, 145: fine grinder

47, 147: polishers

51, 53, 55, 57, 151, 153, 155, 157: wafer

70, 170: wafer transfer apparatus

81: robot arm

83: adsorption fan

185 guide rail

90, 190: tape mounting part

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor package manufacturing apparatus, and more particularly, to a thin wafer transfer apparatus capable of transferring a thin wafer on which a wafer backside polishing process is completed from a wafer backside polishing apparatus to a tape mounting unit regardless of warpage. .

After a series of wafer fabrication processes, the wafer is subjected to a wafer backside polishing process. Wafer backside polishing is a process of mechanically polishing the backside of a wafer to reduce the thickness of the wafer. After the wafer back polishing process is completed, the wafer is transferred to the tape mounting unit, and the adhesive tape is adhered to the back of the wafer and fixed by a wafer ring.

Generally, as shown in FIG. 1, the wafer backside polishing apparatus 10 that performs the wafer backside polishing process is an apparatus for polishing the backside of the wafer in the order of waiting, roughing, finishing, and polishing steps. That is, in this wafer backside polishing apparatus 10, when the turn table 20 provided with four chuck tables 31, 33, 35, and 37 is rotated, roughing except the chuck table 31 in the waiting stage is performed. Wafers 53, 55 and 57 mounted on chuck tables 33, 35 and 37 by grinders 43, 45 and 47 respectively installed on top of chuck tables 33, 35 and 37 in the finishing and polishing stages. The polishing process for) is performed.

When the wafer back surface polishing process is completed, the wafer 57 mounted on the chuck table 37 in the polishing step is transferred to the tape mounting unit 90 by the wafer transfer device 70. That is, after the vacuum suction of the wafer 57 to be transferred using the suction fan 83 at the end of the robot arm 81 at the top, the suction fan 83 moves according to the operation of the robot arm 81 to move the wafer ( 57) Transfer. At this time, although not shown, the wafer 57 conveyed by the wafer transfer device 70 is cleaned by a separately provided cleaning unit (not shown) before reaching the tape mounting unit 90.

However, warpage may occur in the wafer on which the wafer backside polishing process is completed. That is, since the insulating film formed on the entire surface of the wafer and the wafer have different coefficients of thermal expansion (CTE) to protect the metal wiring layer, warpage may occur in the wafer.

Moreover, such warpage is more likely to occur in thin wafers obtained by increasing the wafer backside polishing amount, in accordance with the trend of thinning wafers as the semiconductor package becomes thinner.

As described above, in the case of the thin wafer having the warpage, lifting occurs between the adsorption fan to vacuum suction the thin wafer and the thin wafer having the warpage, so that vacuum leakage occurs. As a result, it is impossible for the conventional wafer transfer device to vacuum-adsorb and transfer the thin wafer having warpage.

Accordingly, it is an object of the present invention to provide a thin wafer transfer apparatus that is independent of warpage generated in a wafer capable of transferring a thin wafer from which a wafer backside polishing process is completed from a wafer backside polishing apparatus, regardless of the warpage generated in the wafer. .

 In order to achieve the above object, the present invention is a device for transferring a thin wafer from the wafer back polishing apparatus for polishing the back surface of the wafer to the tape mounting portion for adhering the adhesive tape to the back surface of the wafer and fixing it with a wafer ring The present invention provides a thin wafer transfer device including a guide rail installed between a wafer backside polishing apparatus and a tape mounting portion and a chuck table for transferring through a guide rail while mounting a thin wafer.

In the thin wafer transfer apparatus according to the embodiment of the present invention, it is preferable that the cleaning portion is located on the guide rail or in the tape mounting portion so that the thin wafer mounted on the chuck table is cleaned.

Hereinafter, with reference to the accompanying drawings will be described in detail an embodiment of the present invention.

2 is a plan view showing a state in which a wafer is transferred by a thin wafer transfer device according to an embodiment of the present invention.

As shown in FIG. 2, the thin wafer transfer device 170 transfers the thin wafer 157 on which the wafer backside polishing process is completed from the wafer backside polishing apparatus 110 to the tape mounting unit 190. This thin wafer transfer device 170 includes a guide rail 185 and a chuck table 137.

The guide rail 185 is a passage through which the thin wafer 157 is transferred and is installed between the wafer backside polishing apparatus 110 and the tape mounting unit 190.

The chuck table 137 moves through the guide rail 185 with the thin wafer 157 mounted thereon to transfer the thin wafer 157. At this time, the rear surface of the thin wafer 157 is mounted on the chuck table 137 so as to face upward. The chuck table 137 vacuum-adsorbs the mounted thin wafer 157 from the bottom thereof.

On the other hand, mounting and fixing the wafer 151 on the chuck table 131 is performed in the wafer backside polishing apparatus 110, and unloading of the thin wafer 157 from the chuck table 137 is performed by a tape mounting portion ( 190).

The wafer backside polishing apparatus 110 includes one turn table 120 and three polishers 143, 145, and 147.

Turn table 120 is rotatable. Four chuck tables 131, 133, 135, and 137 are radially installed on the turn table 120. That is, as the turn table 120 rotates, the respective chuck tables 131, 133, 135, and 137 also rotate. The chuck tables 131, 133, 135, and 137 on the turn table 120 are divided into the waiting table 131, the roughing table 133, the finishing table 135, and the polishing table 137, depending on the position. These chuck tables 131, 133, 135 and 137 are located in the order of the waiting table 131, the roughing table 133, the finishing table 135 and the polishing table 137 in the clockwise direction. In addition, the chuck tables 131, 133, 135, and 137 may be separated from the turn table 120.

Polishers 143, 145, and 147 mechanically polish the back side of wafers 153, 155, and 157 on chuck tables 133, 135, and 137 except for waiting table 131. The grinders 143, 145, and 147 are installed on the roughing machine 143 installed on the roughing table 133, the finishing machine 145 installed on the finishing table 135, and the polishing table 137. A polisher 147 to be included. Each grinder 143, 145 and 147 is capable of lifting and lowering.

The tape mounting unit 190 adheres the adhesive tape to the rear surface of the thin wafer 157 transferred after the wafer rear surface polishing process is completed and fixes the wafer with a wafer ring. At this time, the thin wafer 157 is transferred to the polishing table 137 and then unloaded from the polishing table 137.

Although not shown, the thin wafer 157 mounted on the polishing table 137 transferred by the thin wafer transfer device 170 may be mounted on the guide rail 185 or tape mounting before reaching the tape mounting unit 190. It is cleaned by a cleaning unit (not shown) located in the unit 190.

The thin wafer transfer method using the thin wafer transfer device 170 according to the embodiment of the present invention will be described with reference to a wafer backside polishing process and a tape mounting process.

First, the wafer backside polishing process is performed. This wafer backside polishing process starts from the step where the wafer 151 is mounted on the waiting table 131 and waiting. That is, a wafer transfer machine (not shown) mounts one wafer 151 in alignment with the position of the wafer 151 so as to be suitable for the position to be mounted on the waiting table 131. When the wafer 151 is mounted, the waiting table 131 vacuum-adsorbs and fixes the wafer 151.

Next, the roughing step proceeds. That is, as the turn table 120 rotates, the standby table 131 to which the wafer 151 is adsorbed is rotated 90 ° clockwise to move to the lower part of the roughing machine 143. Then, the roughing machine 143 descends to rough the back surface of the wafer 153. When the roughing step is completed, the roughing machine 143 is raised.

Next, the finishing step is performed. That is, as the turn table 120 rotates, the roughing table 133 on which the roughing step is completed is rotated 90 ° to move to the lower part of the finishing machine 145. The finisher 145 descends to finish the rear surface of the wafer 155. At this time, the wafer 155 has a final thickness. When the finishing step is completed, the finishing machine 145 is raised.

Next, the polishing is performed. That is, according to the rotation of the turn table 120, the finishing table 135 on which the wafer 155 on which the finishing step is completed is adsorbed is rotated 90 ° to move to the lower portion of the polisher 147. The polisher 147 descends to polish the back surface of the wafer 157. At this time, the polishing liquid is supplied to the wafer 157. Accordingly, in the polishing step, the rear surface of the wafer 157 is mirrored, and the thin wafer 157 is formed. When the polishing step is completed, the polisher 147 is raised.

On the other hand, while the wafer back polishing process has been described an example that proceeds step by step according to the rotation of the turn table 120, it is performed simultaneously on the turn table 120.

Subsequently, a thin wafer transfer process proceeds. That is, the polishing table 137 on which the thin wafer 157 on which the polishing step is completed is mounted is separated from the turn table 120 and transferred to the tape mounting unit 190 through the guide rail 185.

At this time, after the polishing step is completed, a step of cleaning the thin wafer 157 is performed to remove the polishing liquid and the debris generated in the polishing step. The cleaning of the thin wafer may be performed on the guide rail 185 while the polishing table 137 on which the thin wafer 157 is mounted is transferred, or the tape mounting unit 190 after being transferred to the tape mounting unit 190. It can also be done within.

Subsequently, the tape mounting process proceeds. That is, the adhesive tape is adhered to the thin wafer 157 on the polishing table 137 transferred to the tape mounting unit 190 and fixed with a wafer ring. Then, the thin wafer 157 fixed with the wafer ring is unloaded from the polishing table 137.

Finally, the step of returning the polishing table 137 is performed. That is, the polishing table 137 which unloads the thin wafer 157 is returned to the turn table 120 through the guide rail 185. At this time, while the polishing table 137 is separated, the turn table 120 is stopped, and the turn table 120 rotates as the polishing table 137 is rotated.

On the other hand, as the turn table 120 rotates, the polishing table 137 which unloads the thin wafer 157 moves to the position of the waiting table 131. The wait table 131 is equipped with another wafer 151 for polishing the back surface.

According to the structure of the present invention, the thin wafer, which easily bends, is mounted on the chuck table and is transferred through the guide rail provided between the wafer backside polishing apparatus and the tape mounting portion, thereby allowing the wafer to be thinned regardless of the warpage generated in the wafer. Can be transferred.

Claims (2)

From a wafer back grinding apparatus that polishes the back side of the wafer, a thin wafer on which the back side grinding process is completed is bonded to the back side of the wafer, and a wafer ring is attached. A device for transporting to a tape mounting part for fixing, A guide rail installed between the wafer backside polishing apparatus and the tape mounting portion; And And a chuck table for transporting through the guide rail while mounting the thin wafer on which the wafer backside polishing process is completed. The thin wafer transfer apparatus of claim 1, wherein a cleaning unit is disposed on the guide rail or in the tape mounting unit to clean the thin wafer mounted on the chuck table.

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