JPH09266182A - Dicing device and its method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To cut and separate a semiconductor wafer into individual semiconductor chips, eliminating scraps which have adverse influence on the quality in after process, in the case of dividing and separating the semiconductor wafer into individual semiconductor chips by cutting it. SOLUTION: In the case of having provided a dicing device with a sheet expansion part 3, which spreads an adhesive sheet 11 for widening the intervals between the semiconductor chips 12 cut and separated from the semiconductor wafer 10 stuck to the adhesive sheet 11, and an ultraviolet ray irradiation part 1, which drops the adhesive capacity of the adhesive agent of the adhesive sheet 11 spreaded, the intervals between the fellow semiconductor chips 12 on the adhesive sheet 11 are widened, and scraps are exposed among them. Together with it, the adhesive force to the scraps is dropped, and then the scraps are removed by the jet force of cleaning water.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dicing apparatus and a method for cutting and separating a semiconductor wafer into individual semiconductor chips, and more particularly to a dicing apparatus in which a semiconductor wafer is attached to an adhesive sheet having an adhesive force on one surface and a blade is completely attached to the adhesive sheet. The present invention relates to a dicing device and a method for cutting the semiconductor chip into semiconductor chips.

[0002]

2. Description of the Related Art Generally, in order to cut and divide a semiconductor wafer into semiconductor chips, a blade called a dicing device and a stage on which a semiconductor wafer is mounted and relatively moved with respect to the blade to cut the semiconductor wafer. It has been performed using a dicing device equipped with. Further, in this dicing device, a semiconductor wafer is attached to an adhesive sheet, placed on a stage, and a rotating blade is completely cut into the semiconductor wafer for cutting. It is an important issue that chips can be efficiently cut without chipping and chips at the time of cutting can be eliminated without adhering to the semiconductor chip.

A dicing method having means for removing chips, which is the latter problem, is disclosed in Japanese Patent Laid-Open No. 159750/1992. This method focuses on the fact that when a semiconductor wafer attached to an adhesive sheet is cut and cut with a blade, the distance between adjacent semiconductor chips that are cut and separated is narrow and chips are difficult to remove. The feature is that the chips are widened and a cleaning liquid is sprayed between the spread semiconductor chips to eliminate chips.

[0004]

However, in the above-mentioned dicing method for removing chips, chips floating between the semiconductor chips and abrasive grains falling off from the blade are eliminated, but when the chips are stuck to the adhesive sheet, There is a problem that the chips in 2 are not eliminated and cannot be completely removed. Moreover, even if the cleaning liquid is increased in ejection pressure to be removed, not only the adhered chips are removed, but also other removed chips are scattered at a high injection pressure and re-adhered to the semiconductor chip, and the quality of the chips is reduced in the subsequent steps described below. Will cause problems.

For example, in a die bonding step which is a subsequent step, chips may intervene on the bonding surface and die bonding strength may not be obtained. Further, even if there is no problem in the bonding step, in the wire bonding step which is the subsequent step, chips attached to the bonding pad may cause connection failure with the wire or chips attached to the surface of the semiconductor chip It damages the circuit formation surface and induces various problems.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a dicing apparatus and a method therefor capable of completely removing chips that cause quality problems in a subsequent process and separating and dividing into semiconductor chips.

[0007]

The features of the present invention are a cutting device for completely cutting a semiconductor wafer attached to an adhesive-coated surface of a pre-adhesive sheet with a blade and separating and dividing into individual semiconductor chips, and a cutting device. A sheet expanding mechanism that expands the adhesive sheet outward in order to widen the distance between the separated semiconductor chips, an adhesive force reducing unit that reduces the adhesive force of the adhesive agent of the adhesive sheet, and an extended adhesive force. And a cleaning device that sprays pure water onto the weakened adhesive sheet to clean it. Further, it is preferable that the adhesive of the pressure-sensitive adhesive sheet is an ultraviolet curable resin and the adhesive force reducing means is an ultraviolet irradiation device.

Another feature of the present invention is that the semiconductor wafer is cut and divided by the blade rotating to the semiconductor chip, and then the pressure-sensitive adhesive sheet is expanded to widen the space between the semiconductor chips, thereby This is a dicing method in which the adhesive strength of the adhesive is reduced and then pure water is sprayed onto the pressure-sensitive adhesive sheet to peel off chips that adhere to the pressure-sensitive adhesive sheet. Further, it is preferable that the method includes a step of cleaning the semiconductor chip and the adhesive sheet with pure water immediately after cutting the semiconductor wafer.

[0009]

Next, the present invention will be described with reference to the drawings.

FIG. 1 is a diagram showing a dicing apparatus according to an embodiment of the present invention. As shown in FIG. 1, this dicing device includes an alignment stage 6 for placing and positioning the semiconductor wafer 10 attached to an adhesive sheet 11 stretched by a frame 10a, and the positioned semiconductor wafer 10 on a stage 5b. The adhesive force of the adhesive sheet 10c is obtained by irradiating the cutting portion 5 provided with the blade 5a that is placed and cut the semiconductor wafer into a dice shape and the adhesive sheet 11 to which the semiconductor wafer 10 cut into the dice shape is attached with ultraviolet rays. Ultraviolet irradiation unit 1 including ultraviolet lamp 1a for lowering
A sheet expansion part 3 for expanding the distance between the semiconductor chips 12 that are cut and divided by pulling the pressure-sensitive adhesive sheet 11 having reduced adhesive force to the outside, and the pressure-sensitive adhesive sheet 11 and the semiconductor chips 12 for which the distance between the semiconductor chips 12 is increased. The cleaning stage 4 is provided for spraying the cleaning liquid from the nozzle 4a and cleaning while rotating the cleaning liquid.

Although not shown in the drawing, the frame 10a
A transport mechanism is provided for sequentially transporting and positioning the semiconductor wafer 10 attached to the pressure-sensitive adhesive sheet 11 stretched in the direction of arrows A, B, C, D, and E. The cutting unit 5, the alignment stage 6, and the cleaning stage 4 have the same mechanism as the conventional one.

The ultraviolet irradiation unit 1 is composed of a plurality of ultraviolet lamps 1a for projecting ultraviolet rays from the back surface side of the adhesive sheet 11, and the ultraviolet rays are uniformly applied to the adhesive sheet 11 to which the semiconductor wafer 10 mounted on the stage is attached. Therefore, these ultraviolet lamps 1a are arranged side by side. The performance of these ultraviolet lamps 1a is, for example, that the illuminance is 1
It satisfies the curing conditions of the UV curable resin such as 20 mW / cm ₂ or more and the light amount of 70 mj / cm ₂ or more.

The sheet expanding section 3 is provided with a mechanism for extending the adhesive sheet 11 of the semiconductor wafer 10 sent in and expanding the interval between the divided semiconductor chips 12. This mechanism includes a claw 10b for gripping and pulling the adhesive sheet 11 protruding from the frame 10a, and a wrench (not shown in the drawing) for loosening or tightening a fastening ring which cooperates with the frame 10a and holds the adhesive sheet 11. I have it.

FIG. 2 is a flow chart for explaining an embodiment of the dicing method of the present invention, FIGS.
(C) is a figure which shows the process in which chips are removed. next,
Regarding the dicing method of the present invention, FIG. 1, FIG. 2 and FIG.
This will be described with reference to FIG. First, in step A of FIG.
The semiconductor wafer 10 attached to the adhesive sheet 11 held by the frame 10a is placed on the alignment stage 6 of FIG. On the alignment stage 6, the position is recognized by the recognition camera and the position of the semiconductor wafer 10 is corrected. The position-corrected semiconductor wafer 10 is processed in step B of FIG.
The semiconductor wafer 10 aligned in step 1 is attached to the stage 5b of the cutting unit 5 in FIG.
Then, the semiconductor wafer 10 is diced by the relative movement of the blade 5a and the stage 5b.

Next, in step C of FIG. 2, it is desirable that the cut semiconductor wafer is transferred to the cleaning stage 4 of FIG. 1, pure water is made to flow from the cleaning nozzle 4a for cleaning, and it is rotated at a high speed and dried. This cleaning is because cutting fluid, cutting wastes, and the like in the cutting portion 5 are fixed to the semiconductor chip 12 during transportation and are difficult to remove in subsequent cleaning. Here, the state of being cut and separated into the semiconductor chips 12 is shown in FIG.
As shown in (a), the semiconductor chips 12 are fixed to the adhesive sheet 11 at intervals substantially equal to the width of the blade 5a. Then, in the case of the semiconductor chip 12 that could not be removed in step C, the chips 13 fixed to the adhesive sheet 11 remain.

Next, in step D of FIG. 2, the adhesive sheet 11 held by the frame 10a is sent to the ultraviolet irradiation unit 1 of FIG. 1 to perform ultraviolet irradiation. Then, step E in FIG.
Then, the adhesive sheet 11 that has been subjected to the ultraviolet curing treatment is sent together with the frame 10a to the expansion sheet portion 3 in FIG. 1, and the adhesive sheet 11 is stretched. As a result, as shown in FIG.
3 appears on the space which is separated from the semiconductor chip 12 and expanded.

Next, in step F of FIG. 2, the adhesive sheet 1
The frame 10a is sent to the cleaning stage 4 of FIG. 1 in a state where 1 is expanded and the distance between the semiconductor chips 12 is expanded. Then, the chips 13 are removed from the pressure-sensitive adhesive sheet 11 in which the adhesive is fragile by spraying pure water from the nozzle 4a, and then, as shown in FIG.
It becomes a state like. After that, the frame 10a is rotated at a high speed to dry the adhesive sheet 11 and the semiconductor chip 12.

In this embodiment, the adhesiveness after the wafer is cut is reduced by combining the adhesive sheet material using the UV curable adhesive and the dicing device having the UV irradiation function. Using curable adhesive,
The same effect can be obtained by combining the device with a dicing device having a heating function such as a heater block or an infrared heater.

Further, since this dicing apparatus is provided with means for weakening the adhesive force of the adhesive sheet so that the semiconductor chip can be easily peeled off from the adhesive sheet, and means for providing a means for widening the gap between the semiconductor chips, the following steps are performed. There is an advantage that it can be easily combined with the die mounter used in the process. What is needed is a device for expanding the distance between the semiconductor chips and a device for weakening the adhesive, which are conventionally provided on the die mounter so that the semiconductor chip can be easily removed from the adhesive sheet. This is because it only needs to be equipped with a stage.

[0020]

As described above, according to the present invention, the sheet expanding mechanism for expanding and expanding the adhesive sheet for expanding the distance between the semiconductor chips cut and separated from the semiconductor wafer attached to the adhesive sheet, and the expanding and expanding operation. A means for reducing the adhesive ability of the adhesive of the pressure-sensitive adhesive sheet is provided to widen the space between the semiconductor chips on the pressure-sensitive adhesive sheet to expose the chips to the space and reduce the adhesive force to the chips, and then to inject the cleaning water. By removing the chips with force, the chips firmly held on the adhesive sheet can also be easily removed. There is an effect that can be.

[Brief description of drawings]

FIG. 1 is a diagram showing a dicing apparatus according to an embodiment of the present invention.

FIG. 2 is a flowchart for explaining an embodiment of a dicing method of the present invention.

FIG. 3 is a diagram showing a process of removing chips.

[Explanation of Codes] 1 UV irradiation part 1a UV lamp 3 Sheet expansion part 4 Cleaning stage 4a Nozzle 5 Cutting part 5a Blade 5b Stage 6 Alignment stage 10 Semiconductor wafer 10a Frame 10b Claw 11 Adhesive sheet 12 Semiconductor chip 13 Chips

Claims (4)

[Claims] 1. A cutting device for completely cutting a blade into a semiconductor wafer attached to an adhesive-coated surface of a pre-adhesive sheet to separate and divide into individual semiconductor chips, and a distance between the cut and separated semiconductor chips. A sheet expansion mechanism that stretches the adhesive sheet outward to expand it, an adhesive force reduction unit that reduces the adhesive force of the adhesive agent of the adhesive sheet, and a pure adhesive sheet on the expanded and weakened adhesive force. A dicing device comprising: a cleaning device that sprays water for cleaning. 2. The dicing apparatus according to claim 1, wherein the adhesive of the pressure-sensitive adhesive sheet is an ultraviolet curable resin, and the adhesive force reducing means is an ultraviolet irradiation device. 3. The semiconductor wafer is cut and divided by the blade rotating to the semiconductor chip, and then the pressure-sensitive adhesive sheet is expanded to widen the gap between the semiconductor chips to increase the adhesive force of the adhesive agent of the pressure-sensitive adhesive sheet. A dicing method, characterized in that, after lowering, the adhesive sheet is sprayed with pure water to remove chips adhered to the adhesive sheet. 4. The dicing method according to claim 3, further comprising a step of cleaning the semiconductor chip and the adhesive sheet with pure water immediately after cutting the semiconductor wafer.