JPS62123737A - Dicing equipment - Google Patents

Abstract

PURPOSE:To effectively prevent the charge of a high-pressure water flow by using pure water itself for cooling a blade and required concentration carbonic acid water for washing. CONSTITUTION:Pure water is supplied from the same water tank 19 to both the nozzle 12 for cooling a blade 11 and the high-pressure injection nozzle 13 for washing. The pure water is directly supplied to the nozzle 12 for cooling from the water tank 19. On the other hand, the pure water from the water tank 19 is introduced in a mixing tank 20 where carbon dioxide is introduced from a cylinder 21 and is mixed with the pure water and required concentration carbonic acid water is made for the high-pressure injection nozzle. By pressurizing the carbonic acid water with a pump 22, a so called high-pressure jet water flow can be injected on a wafer 16 from the nozzle 13. In this way, charging due to the friction of the washing water with the nozzle or with air, etc. can sufficiently be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a technique that is effective when applied to improving the performance of a Guisong device.

[Background technology]

When the so-called unifly process, which is a semiconductor device manufacturing process, is completed, dicing is performed to separate the wafer into individual semiconductor pellets.

The above-mentioned dicing step can be performed using a die song device equipped with a rotatable dicing blade and a high-pressure water spray nozzle for cleaning the wafer after dicing. The above-mentioned dicing blade has a circular plate made of a corrosion-resistant metal with nickel (Ni
) is used as a binder to fix diamond particles.

Wafer dicing is performed by rotating the blade and cutting the wafer with a diamond fixed to the blade. At this time, since a large amount of heat is generated due to friction between the wafer and the blade, the blade and wafer are cooled while spraying cooling water onto the blade.

Further, cleaning of the wafer after dicing can be performed by spraying a so-called high-pressure jet water stream onto the wafer. When pure water is used as the cleaning water, the high-pressure jet water stream has a property of being charged with static electricity due to friction between the pure water and the nozzle or friction with the air. Therefore,
There is a problem that circuit elements of semiconductor pellets may be damaged by electrostatic discharge.

Therefore, it is possible to adopt as an effective means to dissolve carbon dioxide gas in the pure water used for cleaning to lower the specific resistance of the pure water.

By the way, since static electricity is likely to be generated in the Guinong step, it is considered more effective to use water in which carbon dioxide gas is dissolved, that is, carbonated water, also as the cooling water for the blade.

However, when carbonated water, especially carbonated water with a sufficient concentration to prevent the high-pressure jet water flow from being charged, is used as the cooling water, nickel (N) in the binder in the blade is used.
It has become clear that diamond particles fall off early because i) is gradually dissolved in carbonated water. the result,
The inventor has discovered that there is a problem in that the life of the blade is extremely shortened.

Regarding the dicing technology, please refer to Japanese Patent Application Laid-Open No. 59-134.
It is described in the specification of No. 849.

[Purpose of the invention]

An object of the present invention is to provide a technique that can effectively prevent electrostatic damage to circuit elements during a cleaning process and extend the life of a dicing blade.

The above and other objects and novel features of the present invention will become apparent from the description of this specification and the accompanying drawings.

[Summary of the invention]

A brief overview of typical inventions disclosed in this application is as follows.

In other words, for a dicing device equipped with a means for supplying cooling water for the dicing blade and a means for supplying high-pressure water for wafer cleaning, the high-pressure water for wafer cleaning must be heated at a temperature of 4 degrees, which is sufficient to prevent electrostatic damage. By dissolving carbon dioxide gas and dissolving it in the cooling water for the blades, the specific resistance of the high-pressure water for cleaning can be lowered by dissolving carbon dioxide gas that is not dissolved in the cooling water for the blades or has a concentration lower than that of the high-pressure water. This can be effectively prevented and the carbon dioxide concentration of the blade cooling water can be reduced to zero or a low value, thereby preventing the binder metal such as nickel that fixes the diamond in the blade from dissolving. Therefore, the above objective is achieved.

The fact that the binder metal rapidly dissolves due to the presence of carbon dioxide dissolved in the cooling water was first clarified as a result of intensive research by the present inventor.

〔Example〕

FIG. 1 is a schematic explanatory view showing a part of a dicing apparatus according to an embodiment of the present invention, and FIG. 2 is a schematic plan view showing the dicing apparatus of this embodiment. Moreover, FIG. 3 is an enlarged partial front view of the dicing blade of the dicing apparatus.

In the dicing apparatus of this embodiment, a stage 2 and an XY table 3, each having a plurality of operating parts, are fixed to a main body 1.

The stage 2 is provided with a wafer loader 4, a preliminary positioning section 5, a positioning section 6, a dicing section 7, a cleaning section 8, an operating section of a wafer unloader 9, and the like. In addition, spindle morph 1 is placed on XY table 3.
0 is fixed, and a blade 11 is rotatably attached to the tip of the motor IO. In the vicinity of the dicing section 7, a cooling nozzle 1 for the blade 11 is provided.
2 is installed. Furthermore, an arm 14 having a high-pressure injection nozzle 13 at its tip is rotatably attached to a support shaft 15 in the washing section 8 . In addition, in the figure, a partially cut-out circle indicates the wafer 16.

In the dicing apparatus of this embodiment, work is performed in the following steps. First, the wafer 16 is transferred from the loader 14 located at the right end in the figure to the preliminary positioning section 5 using a transfer jig (not shown).
The wafer is then moved to the positioning section 6 for accurate positioning on the wafer chuck table 17. Next, the chuck table 17 is moved to the dicing section 7, and the wafer 16 thereon is diced with the blade 2. At this stage, the separated semiconductor pellets are held by an adhesive tape, or the wafer is cut to the extent that each semiconductor pellet can be broken.

After dicing, the wafer 16 is returned to the positioning section 6 and moved to the next cleaning section, and after cleaning, it is stored in the unloader 9 through a drying process (not shown).

A portion of the dicing apparatus described above is shown in more detail in FIG. This figure schematically shows the structural relationship between the dicing section 7 and the cleaning section 8 in the apparatus shown in FIG. 2.

That is, a wafer chuck table 17 that is movable in the left and right direction is installed in the dicing section 7.
A wafer 16 is positioned and fixed. The blade 11 is positioned at a height capable of cutting the wafer 16,
The cooling nozzle 12 is arranged at a position where water can be sprayed onto the blade 11 at the cutting position of the wafer 16.

On the other hand, a spinner table 18 supported by a rotating shaft is installed in the cleaning section 8, and while rotating the table 18, a jet nozzle positioned above the wafer 16 is placed on the wafer 16 placed on the spinner table 18. The wafer 16 is cleaned by injecting a high-pressure jet water stream from the wafer 13 .

Pure water is supplied from the same water tank 19 to both the cooling nozzle 12 and the high-pressure cleaning nozzle 13 of the blade 11. Pure water is directly supplied to the cooling nozzle 12 from the water tank 19 . To one high pressure injection nozzle,
Pure water from the water tank 19 is introduced into a mixing tank 20, and mixed with carbon dioxide gas introduced from a cylinder 21 in the mixing tank 20 to produce carbonated water of a predetermined concentration. By pressurizing this carbonated water with the pump 22, it can be sprayed onto the wafer 16 from the spray nozzle 13 as a so-called high-pressure jet water stream. In addition, 23 is a check valve,
This is provided to prevent liquid from the mixing tank from flowing into the water tank or the nozzle 12.

Next, the operation of this embodiment will be explained.

As described above, in the dicing apparatus of this embodiment, pure water is used as is as the cooling water for the blade 11, and carbonated water of a predetermined concentration is used as the cleaning water. Here, the predetermined concentration is a concentration that can sufficiently prevent charging due to friction between the cleaning water and the nozzle, air, etc. even when the cleaning water is injected at high pressure.

Therefore, the wafer 16 can be cleaned without electrostatic damage to circuit elements caused by the high-pressure water jet.

On the other hand, if the wafer chuck table is sufficiently grounded, pure water can be used as cooling water for the blade. This is because, unlike the case of the above-mentioned cleaning water, the cooling water itself does not become electrically charged because high-pressure injection is not required.

Furthermore, if carbon dioxide gas is dissolved in the cooling water, the disk 11 of the blade 11 made of high-strength metal as shown in FIG.
There is a problem in that nickel (Ni) 11C, which is a binder for fixing the diamond particles 11b to a, dissolves in the cooling water. However, in the device of this embodiment,
Since there is no carbon dioxide gas in the cooling water, the above problem does not occur.

Therefore, the blade 11 due to the gradual consumption of nickel llc and the loss of diamond llb.
It is possible to prevent shortening of the lifespan.

As described above, the dicing apparatus of this embodiment can prevent electrostatic damage to circuit elements formed on the wafer 11 during wafer cleaning, and can extend the life of the blade used for dicing. Therefore, by using the above-mentioned apparatus, the number of wafers processed per blade can be greatly increased, and the yield can also be improved, thereby reducing the cost of semiconductor pellets and, by extension, the semiconductor devices on which the pellets are mounted. can be achieved.

〔effect〕

fil, for a dicing device equipped with a means for supplying cooling water for the dicing blade and a means for supplying high-pressure water for cleaning wafers, the high-pressure water for cleaning wafers is supplied with a sufficient amount of 7 degrees to prevent electrostatic damage. By dissolving carbon dioxide and dissolving carbon dioxide that is not dissolved in the cooling water for the blades or has a concentration lower than that of the high-pressure water, the specific resistance of the high-pressure water in the cleaning process can be lowered. Since it can effectively prevent static electricity and reduce the carbon dioxide concentration of the blade cooling water to zero or a low value, it prevents the consumption of binder metals such as nickel that dissolve in carbonated water that fix diamonds in the blade. can.

(2) According to (1) above, electrostatic damage to circuit elements formed on the wafer can be effectively prevented during the cleaning process;
Moreover, the life of the dicing blade can be extended.

(3) With (2) above, it is possible to improve the yield of semiconductor pellets and increase the number of semiconductor pellets processed per dicing blade, resulting in a significant cost reduction of semiconductor pellets. can.

Although the invention made by the present inventor has been specifically explained above based on Examples, it goes without saying that the present invention is not limited to the Examples and can be modified in various ways without departing from the gist thereof. Nor.

For example, in the above embodiments, the cooling water for the blades was explained as having no carbon dioxide dissolved therein, but this is not necessarily the case, and the cooling water does not have any effect on the nickel metal of the blades, or may have a noticeable appearance. It goes without saying that carbonated water with a very low concentration may be used.

[BRIEF DESCRIPTION OF THE DRAWINGS] Fig. 1 is a schematic explanatory diagram showing a part of a dicing apparatus according to an embodiment of the present invention; Fig. 2 is a schematic plan view showing a dicing apparatus according to the present embodiment; It is an enlarged partial front view of the dicing blade of the said dicing apparatus. DESCRIPTION OF SYMBOLS 1... Main body, 2... Stage, 3... XY table, 4... Wafer loader, 5... Preliminary positioning section, 6... Place 1 alignment section, 7... Dicing section, 8・
...Cleaning section, 9...Wafer unloader, 10...Motor, 11...Blade, lla...Disc, llb
...diamond particles, IIC...nickel (Ni
), 12... Cooling nozzle, 13... High pressure injection nozzle, ■4... Arm, 15... Support shaft, 16... Wafer, 17... Chuck table, 1 day... Spinner table, 19... Water tank, 20... Mixing tank, 21
...To the carbon dioxide gas bong, 22...Pump, 23...
・Return prevention valve. 1st Figure 6:'7

Claims (1)

[Scope of Claims] 1. A dicing apparatus comprising means for supplying cooling water for a dicing blade and means for supplying high-pressure water used for wafer cleaning, the apparatus comprising means for supplying carbon dioxide gas to the high-pressure water. dicing equipment. 2. The dicing apparatus according to claim 1, wherein the blade cooling water contains carbon dioxide at a lower concentration than pure water or jetted high-pressure water.