JP2013004627A - Wafer separation unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wafer separation unit which separates wafers, formed by slicing ingots, one by one and easily and evenly cleans front and rear surfaces of each wafer.SOLUTION: A separation unit 2 includes: a holder 20 holding a wafer W, formed by sliding an ingot adhered to a support base C with an adhesive into a strip like shape with a part of the support base C included therein, in a manner that the wafer W is hung on the support base C; and a separation hand 22 for attracting the wafers W one by one and separating each wafer W at the part of the support base C.

Description

  The present invention relates to a wafer separating apparatus for separating wafers formed by slicing an ingot into strips one by one.

  Generally, a wafer is formed by slicing an ingot attached to a support base with an adhesive into a thin strip shape with a wire saw. The wafer immediately after slicing is first cleaned in a rough cleaning process. In the rough cleaning step, the wafer is sliced in a strip shape and dipped in the cleaning tank while being hung on the support table, and the sliced powder, abrasive grains, coolant, and the like attached to the wafer surface are cleaned and removed.

  Next, the wafer is transferred together with the support table to the peeling immersion tank, immersed in a chemical solution in the peeling tank, and heated. As a result, the adhesive is melted, the wafer is peeled off from the support base, and freely falls to the bottom of the peeling immersion tank. The dropped wafer is manually picked up from the bottom of the peeling tank and then inserted into the temporary cassette, etc., in the correct orientation, and the posture is held, or the temporary cassette received at the time of dropping is inserted in advance. There is also. Then, the wafers stored in the temporary cassette are taken out one by one by hand or by a separation / extraction mechanism, separated one by one into the cleaning cassette, and sent to the finish cleaning process.

  Further, for example, in Patent Document 1, a wafer attached to a support base by an adhesive is cleaned in a state of being accommodated in a first cassette, and the cleaned wafer is peeled off from the support base. It is described that the wafer peeled off is supported on a holding rod in a state where it is held so as not to fall down by both regulating plates provided in the first cassette. Further, the support base peeled off from the wafer is taken out from the first cassette by a known manipulator or robot, and the wafer peeled off from the support base is supported in such a manner that its axis is horizontal while being accommodated in the first cassette. It is described that it is supported on a table and separated one by one and accommodated in a second cassette.

Japanese Patent No. 3377161

  Nowadays, efforts to reduce the thickness of wafers and the introduction of fixed abrasive slicing technology are progressing, and the wire diameter of the wire saw has become thinner, and the gap between wafers in the state of being sliced into strips and hanging on a support base Is reduced to about 0.14 mm. On the other hand, since the size of the wafer is as long as about 125 to 155 mm, it is extremely difficult to clean the gap between the wafers in a state where the wafer is hanging on the support base as in the past, and a great deal of time and labor are required. However, there is a problem that the quality is not stable despite the need for.

  Further, since the wafer sliced by the fixed abrasive wire has high surface smoothness, it is supported on the support base so that the axis of the wafer becomes horizontal by peeling from the support base as described in Patent Document 1. In this case, the peeled wafers are affected by the saw marks, and the wafers are firmly adhered to each other. The more closely the wafers are cleaned, the more the wafers adhere to each other. As a result, it becomes difficult to separate the wafers one by one, leading to a decrease in yield.

  Accordingly, an object of the present invention is to provide a wafer separation apparatus that separates wafers formed by slicing an ingot one by one and makes it possible to clean the front and back surfaces of the wafer easily and uniformly.

  In the wafer separation apparatus of the present invention, a wafer formed by slicing a strip including an ingot attached to a support base with an adhesive up to a part of the support base is suspended from the support base. A holder for holding the wafer in a state and a separation hand for sucking and separating the wafers one by one.

  According to the wafer separation apparatus of the present invention, the wafer formed by slicing the strip formed in a strip shape including the ingot attached to the support table with an adhesive up to a part of the support table is supported one by one. By separating at this portion, it becomes possible to clean the front and back surfaces of the separated wafer one by one. Further, although the piece of the support base and the adhesive remain on the cleaned wafer, the wafer is removed by immersing the wafer in the release layer and peeling the piece of the support base and the adhesive from the wafer. be able to.

  Here, it is desirable that the separation hand is one that sucks the wafer and folds it at the support base. As a result, the wafers held by the holder can be attracted to the separation hand one by one, and can be broken and separated one by one at the support base.

  In addition, it is desirable that the separation hand be rotated while the wafer is adsorbed and folded at the support base. As a result, the wafers held by the holder are attracted to the separation hand one by one, and the separation hand is rotated while the wafers are attracted, whereby the wafer can be broken and separated one by one at the support base. .

  In addition, the wafer separation apparatus of the present invention desirably separates the wafer held by the holder while immersed in water. Thereby, it is possible to prevent the front and back surfaces from drying while separating the wafers sliced into strips one by one.

(1) A holder for holding a wafer formed by slicing a strip including an ingot attached to a support base with an adhesive up to a part of the support base in a state where the wafer is suspended from the support base;・ Each wafer is separated one by one by the structure that includes a separation hand for picking up wafers one by one and separating them at the support base part, making it easy to separate the front and back surfaces of the wafers one by one In addition, uniform cleaning can be performed, and a high-quality wafer can be stably obtained.

(2) Since the separation hand sucks the wafers and folds them at the support table, the wafers held by the holder are sucked by the separation hands one by one and broken at the support table one by one. The wafer can be separated without using complicated singulation.

(3) Since the separation hand rotates with the wafer adsorbed and is folded at the support base, the wafer held by the holder is adsorbed to the separation hand one by one, and this wafer is adsorbed. By rotating the separation hand in this state, it is possible to break up and separate one by one at the support base, and it is possible to separate the wafers by a simple rotation mechanism.

(4) The structure including the water tank that separates the wafer held in the holder while being immersed in water allows the front and back surfaces to dry while separating the wafers sliced into strips one by one. Therefore, the front and back surfaces of each wafer can be cleaned one by one without drying the slicing powder, abrasive grains, coolant, etc. adhering to the wafer surface by slicing.

It is a schematic block diagram which shows a part of wafer manufacturing apparatus in embodiment of this invention. It is a schematic block diagram of the separation apparatus of FIG. FIG. 3 is a plan view of FIG. 2. FIG. 3 is a left side view of FIG. 2. It is an operation | movement flowchart of a separation apparatus. It is explanatory drawing which shows the structure cut | disconnected by an ultrasonic cutter. It is explanatory drawing which shows the structure cut | disconnected by a high-speed water jet. It is explanatory drawing which shows the structure cut | disconnected by a laser beam. It is explanatory drawing which shows the structure cut | disconnected by a wire saw. It is explanatory drawing which shows the structure cut | disconnected by a band saw. It is explanatory drawing which shows the structure cut | disconnected by a circular saw.

FIG. 1 is a schematic configuration diagram showing a part of a wafer manufacturing apparatus according to an embodiment of the present invention. Referring to FIG. 1, a wafer manufacturing apparatus 1 according to an embodiment of the present invention includes a separation apparatus 2 that separates wafers W formed by slicing an ingot S made of single crystal silicon into strips by a slice machine M _{1 one} by one. And a cleaning device 3 for cleaning the separated wafers W one by one, a wafer stuffing device 4 for storing the cleaned wafers W in a cassette, and a separation for peeling off carbon etc. remaining on the separated wafers W It has a tank 5 and a cleaning tank group 6 for performing additional cleaning of the wafer W.

Ingot S is the support base C (see FIG. 6.) Made of carbon steel plate supported by a support plate P via, it is sliced in a strip shape by slicing machine M _1. The ingot S is adhered to the support base C with an adhesive (not shown), is sliced into a strip shape including part of the support base C, and the wafer W remains suspended from the support base C. , taken out from the slice machine M ₁ by the slice unloader M _2, it is set to the separator 2.

  As shown in FIGS. 2 to 4, the separation device 2 holds the sliced wafer W in a state of being hung from the support base C, and the state in which the wafer W held by the holder 20 is immersed in water. And a separation hand 22 for separating the wafers W one by one.

  The separation hand 22 includes a suction pad 23 that sucks the wafer W, a substantially L-shaped rotation arm 24 that rotates the suction pad 23, a support base 25 that rotatably supports the rotation arm 24, and a separation hand. A forward / backward actuator 26 for moving the separation hand 22 back and forth, a pitch feed actuator 27 for moving the separation hand 22 at the pitch of the wafer W held by the holder 20, and a rotation actuator for rotating the separation hand 22 28.

  In the present embodiment, the support base 25 is held by the forward / reverse actuator 26, and the forward / backward actuator 26 is held by the pitch feed actuator 27. The turning actuator 28 turns the separation hand 22 by turning the turning arm 24. That is, the separation hand 22 is in a direction perpendicular to the suction surface of the wafer W (the left side surface in FIG. 2 and the front surface in FIG. 4) (the left-right direction in FIGS. 2 and 3) and parallel to the suction surface of the wafer W. 3 can be moved in the front-rear direction (vertical direction in FIG. 3 and left-right direction in FIG. 4), and can be rotated upward (see FIG. 2) with the wafer W adsorbed.

  The cleaning device 3 includes a conveyor device 30 that transports the wafers W one by one, and shower devices 31 a and 31 b disposed above and below the conveyor device 30. As shown in FIG. 2, the conveyor device 30 is configured to move forward and backward toward the lower side of the wafer W attracted to the separation hand 22 by a conveyor forward / backward actuator 32. When the wafer W placed on the conveyor device 30 from the separation hand 22 is transported to the wafer filling device 4 by the conveyor device 30, the cleaning water is sprayed from the shower devices 31 a and 31 b to the front and back surfaces of the wafer W. Wash one by one.

  Here, the operation of the separation apparatus 2 will be described with reference to the flowchart of FIG. First, the forward / backward actuator 26, the pitch feed actuator 27, the rotation actuator 28, and the conveyor forward / backward actuator 32 are operated, and the separation hand 22 and the conveyor device 30 are put on standby at the start position (step S101). At this time, the separation hand 22 is disposed at the rear position (see FIG. 4) of the wafer W on the leftmost side (the conveyor device 30 side described later) in FIGS. 2 and 3, and the conveyor device 30 is indicated by a solid line in FIG. As shown, the separation hand 22 is disposed at a position that does not interfere with the turning operation.

  Next, in a state where the rotating arm 24 (separation hand 22) is slightly rotated upward by the rotation actuator 28, the separation hand 22 is advanced by the forward / reverse actuator 26, and the wafer W in the holder 20 can be adsorbed. Arrange to the position (step S102). Subsequently, the rotation arm 24 is slightly rotated downward by the rotation actuator 28 so that the suction surface of the suction pad 23 of the separation hand 22 is parallel to the suction surface of the wafer W (step S103). One of the wafers W is sucked (step S104).

  Next, when the rotation arm 24 is rotated to the upper intermediate position by the rotation actuator 28, the wafer W is separated at the portion of the support base C (step S105). Next, the separation hand 22 is moved backward by the forward / reverse actuator 26 with the wafer W adsorbed (step S106), and the separation hand 22 is rotated to a position above the conveyor device 30 by the rotation actuator 28 (step S107). .

  Next, the conveyor forward / reverse actuator 32 advances the conveyor device 30 to a receiving position below the wafer W attracted by the separation hand 22 (step S108). Next, the wafer W sucked on the suction pad 23 is released, placed on the conveyor device 30, and conveyed by the conveyor device 30 (step S109). Here, the front and back surfaces of the wafers W are cleaned one by one with the cleaning water sprayed from the shower devices 31 a and 31 b while being transferred by the conveyor device 30.

  Next, the conveyor device 30 is moved backward to the standby position by the conveyor forward / reverse actuator 32 (step S110). Thereafter, the separation hand 22 is rotated downward by the rotation actuator 28 (step S111). Then, the separation hand 22 is pitch-fed to the position of the next wafer W by the pitch feed actuator 27 (step S112), and the process returns to step S102 to repeatedly perform the wafer W separation operation.

  The wafer stuffing device 4 stores the wafers W after cleaning, which are conveyed one by one by the conveyor device 30, one by one in the cassette 40. Each time the wafer W is accommodated one by one, the cassette 40 is gradually lowered into the water tank 41 and immersed in the water in the water tank 41. The cassette 40 in which the wafer W has been accommodated is transferred to the peeling tank 5 by the cassette transfer machine 7.

  In the peeling tank 5, the section of the support table C and the adhesive interposed between the support table C and the wafer W are peeled from the wafer W separated at the support table C by the separation hand 22. In the present embodiment, the support base C is a carbon plate, and the wafer W and the cassette 40 are immersed in a chemical capable of peeling off the carbon and the adhesive, whereby the carbon and the like are peeled off from the wafer W. The cassette 40 from which carbon or the like has been peeled is sequentially transported through the cleaning tank group 6 by the cassette transporter 8 and is subjected to additional cleaning.

  In the wafer manufacturing apparatus 1 having the above-described configuration, the wafer W formed by slicing in a strip shape including the ingot S adhered to the support base C with an adhesive up to a part of the support base C is supported as in the past. Rather than performing rough cleaning while hanging on the table C, the support table C is separated one by one by the separation device 2, and the front and back surfaces of the separated wafers W are washed one by one by the cleaning device 3. . Therefore, in this wafer manufacturing apparatus 1, the front and back surfaces of the wafer W can be easily and easily formed regardless of the gap (pitch) between the wafers W and the size of the wafers W when they are sliced into strips and hung on the support base C. Cleaning can be performed uniformly, and a high-quality wafer can be stably obtained.

Further, in the wafer manufacturing apparatus 1, the separation device 2, the wafer W is attracted to the suction pad 23, by integrating the wafer W and the suction pad 23 to enhance the rigidity, the cutting of the support C by slicing machines M ₁ By rotating the separation hand 22 with the end point as a base point, the already cut portion of the support base C is separated from the uncut portion of the support base. Therefore, it is preferable that the support base C satisfies the condition that the strength of the support base C ≦ (suction pad 23 + wafer W). In this embodiment, a carbon plate is used, but a resin plate, an alumina plate, or the like is used. It is also possible to use.

  Further, in the separation apparatus 2 in the present embodiment, the wafers W held by the holder 20 are adsorbed and separated by the separation hand 22 in a state of being immersed in water by the water tank 21, so that the wafers W are separated from the support base C one by one. While separating, it is possible to prevent the front and back surfaces from drying, and the cleaning device 3 does not dry the slicing powder, abrasive grains, coolant, etc. adhering to the surface of the wafer W by slicing. The front and back surfaces can be cleaned one by one.

  As for the cleaned wafers W, the wafers W, which have been cleaned one by one, are stored in the cassette 40 by the wafer filling device 4, and the cassette 40 is gradually stored in the water tank 41 each time the wafers W are stored one by one. It is lowered and immersed in the water in the water tank 41, and the carbon and the like in the next peeling tank 5 are peeled off without drying the front and back surfaces of the wafer W while the wafers W are stored one by one. It is possible to do.

  Furthermore, in the wafer manufacturing apparatus 1 according to the present embodiment, since the cassette 40 in which the wafer W is accommodated is immersed in the peeling tank 5, the section of the support base C and the adhesive are peeled off from the wafer W. The wafers W separated from each other do not come into contact with each other in the subsequent process, and it is possible to prevent quality deterioration due to poor handling of the wafers W and to improve the yield.

  In the separation apparatus 2 according to the present embodiment, the separation hand 22 is movable in the front-rear direction within a plane parallel to the suction surface of the wafer W, but is not limited to the front-rear direction. In short, it is only necessary that the separation hand 22 can be moved in the advancing and retreating direction within a plane parallel to the suction surface of the wafer W with respect to the holder 20.

  Further, in the separation apparatus 2 according to the present embodiment, the separation hand 22 sucks and rotates the wafer W one by one, but the wafer W is separated by a method other than the folding. It is also possible. Examples of other separation means include those shown in FIGS.

  FIG. 6 shows a configuration for cutting with an ultrasonic cutter. As shown in FIG. 6A, the ultrasonic cutter 50 in a state where the suction surface (front side of FIG. 6A) of the wafer W suspended from the support C is sucked by the separation hand 22 (not shown). To cut and separate one by one. At this time, as shown in FIG. 4B, the tip of the cutter blade 50a of the ultrasonic cutter 50 is moved in contact with the portion of the support base C that supports the wafer W, and the portion of the support base C is cut. . Thereby, the wafers W are separated one by one while being attracted to the separation hand 22. The section of the support base C and the adhesive remaining on the wafer W are separated by the release layer 5 as described above.

  FIG. 7 shows a configuration for cutting with a high-speed water jet. As shown in FIG. 6A, the high-pressure water nozzle gun 51 is in a state where the suction surface of the wafer W suspended from the support C (the front surface of FIG. 6A) is sucked by a separation hand 22 (not shown). The high pressure water 51a is ejected from the water and cut and separated one by one. At this time, as shown in FIG. 5B, the tip of the high-pressure water 51a sprayed from the high-pressure water nozzle gun 51 is moved in contact with the portion of the support base C that supports the wafer W, and the part of the support base C is moved. Disconnect. Thereby, the wafers W are separated one by one while being attracted to the separation hand 22.

  FIG. 8 shows a configuration for cutting with laser light. As shown in FIG. 6A, the laser irradiation head 52 is in a state where the suction surface (front side of FIG. 6A) of the wafer W hung from the support table C is sucked by the separation hand 22 (not shown). Are cut and separated one by one by irradiating them with a laser beam. At this time, as shown in FIG. 4B, the tip of the laser beam 52a irradiated from the laser irradiation head 52 is moved in contact with the portion of the support base C that supports the wafer W, and the portion of the support base C is moved. Disconnect. Thereby, the wafers W are separated one by one while being attracted to the separation hand 22.

  FIG. 9 shows a configuration for cutting with a wire saw. As shown in FIG. 6A, the wafer W suspended by the support base C is attracted by the wire saw 53 while being attracted by the separation hand 22 (not shown). Cut and separate one by one. At this time, as shown in FIG. 5B, the fixed abrasive wire 53a of the wire saw 53 is brought into contact with the portion of the support base C that supports the wafer W, and is reciprocated along the suction surface of the wafer W to support it. The part of the base C is cut. Thereby, the wafers W are separated one by one while being attracted to the separation hand 22.

  FIG. 10 shows a configuration for cutting with a band saw. As shown in FIG. 6A, the band saw 54 is in a state where the suction surface (front side of FIG. 5A) of the wafer W hung on the support base C is sucked by the separation hand 22 (not shown). To cut and separate one by one. At this time, as shown in FIG. 4B, the saw blade 54a of the band saw 54 is brought into contact with the portion of the support base C that supports the wafer W, and is reciprocated along the suction surface of the wafer W. A portion of the support base C is cut. Thereby, the wafers W are separated one by one while being attracted to the separation hand 22.

  FIG. 11 shows a configuration for cutting with a circular saw. As shown in FIG. 6A, the circular saw 55 is shown in a state where the suction surface (front side of FIG. 6A) of the wafer W hung on the support table C is sucked by the separation hand 22 (not shown). To cut and separate one by one. At this time, as shown in FIG. 5B, the rotary cutter 55a of the circular saw 55 is brought into contact with the portion of the support table C that supports the wafer W, and is moved along the suction surface of the wafer W, thereby supporting the support table. Cut part C. Thereby, the wafers W are separated one by one while being attracted to the separation hand 22. The same configuration is used when cutting with a dicing saw or grinder.

  The wafer separation apparatus of the present invention is useful as an apparatus for separating wafers formed by slicing ingots one by one.

DESCRIPTION OF SYMBOLS 1 Wafer manufacturing apparatus 2 Separation apparatus 3 Cleaning apparatus 4 Wafer filling apparatus 5 Separation tank 6 Cleaning tank group 20 Holder 21 Water tank 22 Separation hand 23 Adsorption pad 24 Rotating arm 25 Support base 26 Forward / reverse actuator 27 Pitch feed actuator 28 Rotating actuator DESCRIPTION OF SYMBOLS 30 Conveyor apparatus 31a, 31b Shower apparatus 32 Conveyor forward / reverse actuator 40 Cassette 41 Water tank 50 Ultrasonic cutter 51 High pressure water nozzle gun 52 Laser irradiation head 53 Wire saw 54 Band saw 55 Circular saw

Claims (4)

A holder for holding a wafer formed by slicing a strip including an ingot attached to a support base with an adhesive up to a part of the support base in a state where the wafer is suspended from the support base;
A wafer separation apparatus including a separation hand for sucking and separating the wafers one by one.   The wafer separation apparatus according to claim 1, wherein the separation hand sucks the wafer and breaks it at a portion of the support base.   The wafer separation apparatus according to claim 2, wherein the separation hand is configured to bend the wafer by rotating.   The wafer separation apparatus according to claim 1, further comprising a water tank for separating the wafer held by the holder while being immersed in water.

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