JP5017900B2 - Workpiece processing method and apparatus - Google Patents

Description

  The present invention relates to a workpiece processing method and apparatus, and more particularly to a workpiece processing method and apparatus suitable for cleaving brittle materials such as glass and silicon wafers.

2. Description of the Related Art Conventionally, there has been proposed a processing apparatus that cuts a workpiece into a required shape by irradiating the workpiece with a laser beam guided in the liquid column at the same time as jetting liquid column-shaped high-pressure water (for example, a patent) Literature 1, Patent Literature 2).
In addition, after scribing by concentrating laser light in the ultraviolet region having a high absorption rate on a glass body as a workpiece and scanning it along the shape to be processed, along the portion subjected to the scribing There has also been proposed a processing method for cutting a workpiece by irradiating a laser beam in an infrared region having a high absorption rate to give thermal distortion (for example, Patent Document 3).
JP 2001-321977 A Japanese National Patent Publication No. 10-500903 Japanese Patent No. 3036906

By the way, in the processing apparatuses disclosed in Patent Document 1 and Patent Document 2, when the workpiece is thick, even if the above-described processing is performed along the planned cutting line, it cannot be cut by one scan. There were drawbacks.
Further, when the groove is formed on the wafer only by the laser beam as in the processing method of Patent Document 3, the reliability of the electronic circuit formed on the surface of the semiconductor wafer is affected by the thermal effect of the laser beam. There was a problem that the generation of melt called debris increased.

In view of the above-described circumstances, the present invention described in claim 1 is directed to a workpiece by injecting a liquid onto the workpiece along a planned cutting line of the workpiece and transmitting laser light into the liquid. Irradiate with laser light to form a groove at the location of the cutting line on the surface of the workpiece,
Next, a liquid is sprayed onto the work piece along the groove to cause a crack to reach the back surface of the work piece from the groove so that the work piece is cleaved along the planned cutting line. A method for processing an object is provided.
According to a second aspect of the present invention, there is provided a supporting means for supporting a workpiece, a machining head for injecting a liquid onto the workpiece and transmitting a laser beam into the liquid and emitting the liquid, and the supporting Moving means for relatively moving the means and the processing head, liquid supply means for supplying a high-pressure liquid to the processing head, laser light introducing means for introducing laser light oscillated by a laser oscillator into the processing head , A shutter that prevents introduction of laser light into the processing head ,
A liquid is ejected from the machining head to the workpiece along the planned cutting line of the workpiece and laser light is transmitted through the liquid to irradiate the workpiece with laser light. After a groove is formed in the portion of the planned cutting line on the surface, liquid is jetted from the processing head to the workpiece along the groove in a state where introduction of laser light to the processing head is blocked by the shutter. Thus, the present invention provides a processing apparatus for a workpiece, in which a crack reaching the back surface of the workpiece is generated from the groove, and the workpiece is cleaved according to a planned cutting line.
According to a third aspect of the present invention, there is provided a supporting means for supporting a workpiece, a first machining head that ejects a liquid onto the workpiece and transmits a laser beam into the liquid and emits the liquid. A second machining head for injecting liquid onto the workpiece; a moving means for relatively moving the support means and the two machining heads; a liquid supply means for supplying high-pressure liquid to the two machining heads; and the first machining. Laser light introducing means for introducing laser light into the head,
The liquid is ejected from the first machining head to the workpiece along the planned cutting line of the workpiece, and the workpiece is irradiated with the laser beam by transmitting the laser beam into the liquid. A groove is formed at a position of the planned cutting line on the surface of the object, and a liquid is sprayed from the second processing head to the workpiece along the groove to reach a back surface of the workpiece from the groove. The present invention provides a processing apparatus for a workpiece that is generated and cleaves the workpiece according to a planned cutting line.
Further, the present invention described in claim 4 is a support means for supporting a workpiece, a first machining head that ejects a liquid onto the workpiece and transmits a laser beam into the liquid and emits the liquid. Moving means for relatively moving the support means and the first processing head, liquid supply means for supplying high-pressure liquid to the first processing head, and laser light introduction means for introducing laser light into the first processing head A first station comprising:
A supporting means for supporting a workpiece, a second machining head for injecting a liquid onto the workpiece and transmitting a laser beam into the liquid and emitting the liquid, and the supporting means and the second machining head are relative to each other. A second station comprising moving means for moving and liquid supply means for supplying high-pressure liquid to the second processing head;
In the first station, the workpiece is irradiated with the laser beam by injecting the liquid from the first machining head to the workpiece along the planned cutting line of the workpiece and transmitting the laser beam into the liquid. Then, a groove is formed at the position of the planned cutting line on the surface of the workpiece,
In the second station, a liquid is sprayed from the second processing head to the workpiece along the groove to cause a crack to reach the back surface of the workpiece from the groove, thereby cutting the workpiece along the cutting line. An object of the present invention is to provide a processing apparatus for a workpiece that is divided as described above.

  According to the above-described configuration, even if the workpiece is thick, the workpiece can be cleaved efficiently and reliably. Moreover, even if the workpiece is a semiconductor wafer, there is no possibility of damaging an electronic circuit formed on the surface of the semiconductor wafer, and the occurrence of debris can be suppressed.

Hereinafter, the present invention will be described with reference to the illustrated embodiment. In FIG. 1, reference numeral 1 denotes a hybrid machining apparatus that cleaves a workpiece 3 into a required shape. The hybrid machining apparatus 1 includes a machining head 2, and high-pressure water is ejected from the machining head 2 as a liquid column W onto the workpiece 3 and the laser beam L is transmitted through the liquid column W to be processed. 3 can be irradiated. In this way, the liquid column W is ejected from the machining head 2 to the workpiece 3 and the laser beam L is irradiated, while the machining head 2 and the workpiece 3 are relatively moved in the horizontal direction, thereby the workpiece 3. Can be cleaved as planned.
The hybrid machining apparatus 1 includes a supporting means 4 that horizontally supports the workpiece 3, a YAG laser oscillator 5 that oscillates the laser light L with a Q switch pulse, and a high-pressure water as a liquid column W toward the workpiece 3. The processing head 2 that injects and emits the laser light L into the liquid column W, and the liquid supply means 7 that supplies high-pressure water into the processing head 2 through a conduit 6 are provided. These are controlled by a control device (not shown). The machining head 2 of this embodiment is fixedly arranged on the upper side of the support means 4.

Further, the hybrid machining apparatus 1 includes a shutter 8 on the optical path of the laser beam L oscillated from the YAG laser oscillator 5, and includes a reflection mirror 11 and a condenser lens 12 that are fixedly disposed above the machining head 2. I have. The shutter 8 includes a reflection mirror 14 that is moved forward and backward by an air cylinder 13 to a forward position on the optical path of the laser light L and a backward position that is off the optical path, and an absorber 15 that absorbs the laser light L. Yes. The operation of the air cylinder 13 is controlled by a control device.
When the laser beam L is oscillated from the YAG laser oscillator 5 in a state in which the air cylinder 13 is not operated and the reflection mirror 14 of the shutter 8 is in the retracted position and is not on the optical path of the laser beam L, the laser beam L is reflected. After being reflected by the mirror 11, it is focused by the condenser lens 12 and is incident on the machining head 2.
On the other hand, when the laser beam L is oscillated from the YAG laser oscillator 5, when the air cylinder 13 is operated by the control device and the reflecting mirror 14 of the shutter 8 is moved to the forward position on the optical path of the laser beam L. The laser beam L is reflected by the reflection mirror 14 and absorbed by the absorber 15. That is, introduction of the laser beam L to the machining head 2 is prevented.
The YAG laser oscillator 5 can perform CW oscillation or pulse oscillation in accordance with processing, and can adjust processing conditions such as output and pulse oscillation period as appropriate.

In the present embodiment, for example, a plate-shaped and circular semiconductor wafer is processed as the workpiece 3, and the workpiece 3 is cleaved according to the planned cutting line of the workpiece 3. .
FIG. 2 is an enlarged cross-sectional view of the workpiece 3 shown in FIG. 1. As shown in FIG. 2, the wafer as the workpiece 3 is stuck on an adhesive sheet 3A that transmits laser light L and liquid. The outer peripheral portion of the adhesive sheet 3A is stretched on the lower surface of the wafer ring 3B.
The wafer ring 3B, the pressure-sensitive adhesive sheet 3A, and the wafer as the workpiece 3 are integrated, and the workpiece 3 in this state is placed on the upper surface of the support means 4 and is held on the periphery of the support means 4 It is adapted to be held horizontally by means 16. The central portion of the support means 4 has a honeycomb cross section so that the liquid that has passed through the pressure-sensitive adhesive sheet passes downward during processing. Then, the processed workpiece 3 (product and remaining material) after processing is removed from the holding means 16 together with the wafer ring 3B and the adhesive sheet 3A while being adhered to the adhesive sheet 3A. After that, the workpiece 3 to be newly processed is supplied to the support means 4 and is held by the holding means 16.

The processing head 2 is fixed and arranged so that the high-pressure water injection port faces vertically downward. The laser beam L condensed by the condenser lens 12 is introduced into the machining head 2 through a transparent window provided at the upper end of the machining head 2 and passes through a passage in the machining head 2. The workpiece 4 is irradiated through the liquid column W of the high-pressure water through the injection port.
Next, the support means 4 is provided on the X-direction moving mechanism 17 and is movable in the X direction on the horizontal plane. The X-direction moving mechanism 17 is provided on the Y-direction moving mechanism 18 and can move in the Y direction orthogonal to the X direction on the horizontal plane. The operations of the X-direction moving mechanism 17 and the Y-direction moving mechanism 18 are controlled by a control device (not shown). Then, when both the moving mechanisms 17 and 18 are moved in the XY direction by the required amount by the control device, the workpiece 3 and the processing head 2 on the support means 4 are relatively moved in the XY direction. Yes. In this embodiment, the X-direction moving mechanism 17 and the Y-direction moving mechanism 18 constitute moving means 21 that relatively moves the machining head 2 and the supporting means 4 on a horizontal plane.
Next, the liquid supply means 7 for supplying high-pressure water to the machining head 2 is a conventionally known one. When the liquid supply means 7 is operated by a control device, the high-pressure water is supplied to the passage in the machining head 2 via the conduit 6. Is supplied, and the high-pressure water becomes a liquid column W and is sprayed onto the workpiece 3 by passing through the lowermost injection port communicating therewith.

Thus, in the present embodiment, on the premise of the above-described configuration, the liquid column W is ejected onto the planned cutting line of the workpiece 3 while the machining head 2 and the workpiece 3 are relatively moved, and the laser beam L is irradiated. Then, a minute groove is formed, and then the liquid column W is sprayed onto the workpiece 3 along the groove, so that the workpiece 3 is cleaved according to the planned cutting line.
That is, a process of cleaving the workpiece 2 by the hybrid machining apparatus 1 configured as described above will be described.
First, the workpiece 3 is placed on the support means 4 in a state where the oscillation of the laser light from the YAG laser oscillator 5 is stopped and the supply of high-pressure water from the liquid supply means 7 is stopped. When the workpiece 3 is placed on the support means 4 in this way, the workpiece 3 is fixed on the support means 4 by the holding means 16. At this time, the reflection mirror 14 of the shutter 8 is positioned at a retracted position deviated from the optical path of the laser light L.
Thereafter, both the moving mechanisms 17 and 18 of the moving means 21 are actuated by the control device, and the support means 4 is moved by a required amount in the XY direction on the horizontal plane, and the machining of the workpiece 3 is started below the machining head 2. The position is positioned.

Thereafter, the control device operates the liquid supply means 7 to supply high-pressure water to the machining head 2 via the conduit 6, and the high-pressure water formed in the liquid column W from the machining head 2 is processed into the workpiece 3. Inject to start position. Thereafter, the control device oscillates the laser beam L from the laser oscillator 5, and the laser beam L oscillated from the laser oscillator 5 passes through the liquid column W from the machining head 2 and is irradiated to the machining start position of the workpiece 3. The
The control device moves the processing head 2 and the support means 4 relative to each other via the moving mechanisms 17 and 18 of the moving means 21, so that the irradiation position of the laser light L in the liquid column W is set on the workpiece 3. Relative movement is performed so as to sequentially follow the planned cutting line 22, and thereby, a minute groove 23 having a V-shaped cross section is continuously formed on all the planned cutting lines 22 on the surface 3 </ b> C of the workpiece 2 (see FIG. 3 a). ).

When the groove 23 is formed over the entire cutting line 22 on the surface 3C of the workpiece 3 in this way, the control device thereafter operates the air cylinder 13 of the shutter 8 to cause the reflection mirror 14 to move to the laser beam L. It is positioned at the forward position on the optical path. Therefore, the laser beam L is prevented from entering the processing head 2 from this point.
As a result, the laser beam L is not irradiated onto the workpiece, but since high-pressure water is continuously supplied from the liquid supply means 7 to the processing head 2, only high-pressure water is formed on the liquid column W from the processing head 2. Is injected.
In this state where the liquid column W is ejected from the machining head 2, the control device positions the machining head 2 at the machining start position via the both moving mechanisms 17, 18, and then the cutting schedule line 22. The support means 4 is moved so as to trace the top.
Accordingly, the liquid column W sprayed from the processing head 2 is sprayed along the groove 23 formed in the planned cutting line 22 of the workpiece 3 (see FIG. 3b). As a result, internal stress is generated in the direction of the arrow in FIG. 3b in and around the deep portion of the groove 23 formed in the planned cutting line 22, so that a crack 24 that reaches the back surface 3D from the deepest portion of the groove 23 occurs. The workpiece 3 is completely cleaved as indicated by the cleaving line 22 (see FIG. 3c).

As described above, in the present embodiment, in the first step, when the liquid column W is ejected onto the cleaving line 22 of the workpiece 3, a groove is formed on the surface 3 </ b> C of the workpiece 3 by irradiating the simultaneous laser beam L. 23 is formed, and in the second step, the liquid column W is sprayed along the groove 23 so that the workpiece 3 is completely cleaved as indicated by the cleaving line 22.
Therefore, according to the present embodiment, even if the workpiece 3 is thick, it is possible to efficiently and reliably cleave the workpiece 3 according to the planned cutting line 22. Moreover, even if the workpiece 3 is a semiconductor wafer, there is provided a cleaving method that can prevent the occurrence of debris without causing damage to the electronic circuit formed on the upper surface of the semiconductor wafer. it can.

Next, FIG. 4 shows a second embodiment of the present invention. In the second embodiment, on the premise of the configuration of the first embodiment, the processing head 2 is used as the first processing head 2, and separately from that, high-pressure water is used as the liquid column W and sprayed onto the workpiece 3. A second machining head 102 is provided. High-pressure water can be supplied to the second machining head 102 via a branch pipe 103 branched from the conduit 6, and an electromagnetic on-off valve 104 whose operation is controlled by a control device in the middle of the branch pipe 103. Is provided.
Other configurations are the same as those of the first embodiment, and the same reference numerals are given to members corresponding to the first embodiment.
Also in the second embodiment, the support mechanism 4 and the processing heads 2 and 102 are moved relative to each other in the XY directions on the horizontal plane by the moving mechanisms 17 and 18 of the moving means 21. At this time, in the second embodiment, since the second machining head 102 is disposed slightly apart from the first machining head 2, first, the first machining head 2 precedes the support means 4. The second machining head 2 moves relative to the support means 4 so as to follow the movement.

When the workpiece 3 is cleaved according to the second embodiment, first, the liquid column W is sprayed from the first machining head 2 onto the planned cutting line of the workpiece 3 and transmitted through the liquid column W. The laser beam L is irradiated, and the support unit 4 is relatively moved on the horizontal plane by the moving unit 21. As a result, the groove 23 as shown in FIG. 3 a is formed in the planned cutting line 22, and the liquid column W ejected from the second processing head 102 following the first processing head 2 is formed by the first processing head 2. Injected into the groove 23, the workpiece 3 is completely cleaved as indicated by the cleaving line 22 (see FIGS. 3b and 3c).
According to the second embodiment having such a configuration, the same operation and effect as the first embodiment can be obtained, and the working time can be shortened.

Next, FIG. 5 shows a third embodiment of the present invention. In the third embodiment, the support means 4 in the second embodiment is intermittently transferred from the first station A to the second station B intermittently by the transfer conveyor 105 so as to cleave the workpiece 3 in two steps. I have to.
That is, the workpiece 3 is supplied to the support means 4 on the transport conveyor 105 at a left carry-in position (not shown), and the first station A and the second station are transported on the transport path of the transport conveyor 105. B is provided.
In the first station A, the first processing head 2 is provided so as to be movable in the XY directions on the horizontal plane by a first driving means (not shown), and in the second station B, the same as in the second embodiment. The two machining heads 102 are provided so as to be movable in the XY directions on the horizontal plane by a second driving means (not shown). The laser beam L is introduced from the laser oscillator 5 through the optical fiber 106 to the first processing head 2. In addition, a shutter that prevents oscillation of the laser beam L when necessary is provided inside the laser oscillator 5. The operations of the conveyor 105, the first drive means, the second drive means and the shutter are also controlled by a control device (not shown). Other configurations are the same as those of the second embodiment, and members corresponding to those of the second embodiment are denoted by the same reference numerals.
In the third embodiment, the workpiece 3 on the conveyor 105 is first stopped at the first station A by intermittently running the conveyor 105. Then, the workpiece 3 stopped at the first station A is irradiated with the laser beam L that is injected from the first machining head 2 onto the planned cutting line and is transmitted through the liquid column W, In addition, the first processing head 2 is moved in the horizontal direction along the planned cutting line by the first driving means. As a result, in the first station A, the groove 23 as shown in FIG. 3 a is formed in the planned cutting line 22 of the workpiece 3.
After this, since the conveyor 105 is stopped again after traveling, the first workpiece 3 in which the groove 23 is formed is transferred to the second station B, and at the same time, the second workpiece 3 is moved. Transferred to the first station A.
Then, the second machining head 102 is moved in the horizontal direction by the second driving means with respect to the first workpiece 3 stopped at the second station B, and the liquid column W is moved from the second machining head 102 to the workpiece. Since it is sprayed along the groove | channel 23 of the workpiece 3, the to-be-processed object 3 is completely cleaved according to the cutting projected line 22 (refer FIG. 3b and FIG. 3c).
At the same time, the liquid column W is ejected from the first machining head 2 to the second workpiece 3 at the first station A and irradiated with the laser beam L in the first station A, and the groove 23 is formed in the planned cutting line 22. Is formed.
After this, since the conveyor 105 is stopped after traveling again, the first workpiece 3 that has been cleaved is transported from the second station B to the next process and the second groove 23 is formed. The workpiece 3 is transferred to the second station B.
As described above, in the third embodiment, a groove is formed in the first station A and completely cleaved in the adjacent second station B. By adopting such a configuration, the third embodiment can obtain the same operations and effects as the first embodiment, and can efficiently process a large number of workpieces.
In this third embodiment, when the workpiece is cleaved, the machining head side is moved relative to the workpiece. However, the supporting means of each station is provided on the moving means in the XY directions, and the workpiece is processed. The object side may be moved, or between stations may be transferred by a robot.
In each of the above embodiments, the machining head may be brought close to the workpiece so as not to form a liquid column.
In each of the above embodiments, the pressure of the high-pressure water may be changed depending on when the groove is cut.
Further, each of the above embodiments can also be applied to processing a brittle material other than a semiconductor wafer as a workpiece, in which case laser light having a wavelength corresponding to the material of the workpiece may be used. .

The front view which shows one Example of this invention. Sectional drawing which expanded the principal part of FIG. FIG. 5 is an operation process diagram of the embodiment shown in FIGS. 1 and 4. The front view which shows 2nd Example of this invention. The front view which shows 3rd Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Hybrid processing apparatus 2 ... Processing head (1st processing head)
DESCRIPTION OF SYMBOLS 3 ... Workpiece 5 ... YAG laser oscillator 7 ... Liquid supply means 8 ... Shutter 21 ... Moving means 22 ... Split line 23 ... Groove 105 ... Conveyor (conveyance means)
106: Optical fiber (laser light introducing means) L: Laser light W: Liquid column

Claims (4)

Injecting the liquid onto the workpiece along the planned cutting line of the workpiece and irradiating the workpiece with the laser beam by transmitting the laser beam into the liquid, the cutting schedule on the surface of the workpiece Forming a groove at the line,
Next, liquid is sprayed onto the work piece along the groove to cause a crack to reach the back surface of the work piece from the groove, and the work piece is cleaved according to a planned cutting line. Processing method of work piece. A support means for supporting the workpiece; a machining head for injecting a liquid onto the workpiece and transmitting the laser beam through the liquid; and a moving means for moving the support means and the machining head relative to each other. Liquid supply means for supplying a high-pressure liquid to the processing head, laser light introduction means for introducing laser light oscillated by a laser oscillator into the processing head, and introduction of laser light into the processing head is prevented. With a shutter ,
A liquid is ejected from the machining head to the workpiece along the planned cutting line of the workpiece and laser light is transmitted through the liquid to irradiate the workpiece with laser light. After a groove is formed in the portion of the planned cutting line on the surface, liquid is jetted from the processing head to the workpiece along the groove in a state where introduction of laser light to the processing head is blocked by the shutter. A workpiece processing apparatus characterized by causing a crack to reach the back surface of the workpiece from the groove and cleaving the workpiece according to a planned cutting line. A support means for supporting the workpiece, a first machining head for ejecting a liquid onto the workpiece and transmitting the laser beam through the liquid, and a second machining head for ejecting the liquid onto the workpiece A moving means for relatively moving the support means and the two processing heads, a liquid supply means for supplying a high-pressure liquid to the two processing heads, and a laser light introducing means for introducing laser light into the first processing head. With
The liquid is ejected from the first machining head to the workpiece along the planned cutting line of the workpiece, and the workpiece is irradiated with the laser beam by transmitting the laser beam into the liquid. A groove is formed at a position of the planned cutting line on the surface of the object, and a liquid is sprayed from the second processing head to the workpiece along the groove to reach a back surface of the workpiece from the groove. An apparatus for processing a workpiece, characterized by causing the workpiece to be cut according to a planned cutting line. A supporting means for supporting a workpiece, a first machining head for injecting a liquid onto the workpiece and transmitting a laser beam through the liquid and emitting the liquid, and the supporting means and the first machining head relative to each other. A first station comprising: moving means for moving; liquid supply means for supplying high-pressure liquid to the first processing head; and laser light introducing means for introducing laser light into the first processing head;
A supporting means for supporting a workpiece, a second machining head for injecting a liquid onto the workpiece and transmitting a laser beam into the liquid and emitting the liquid, and the supporting means and the second machining head are relative to each other. A second station comprising moving means for moving and liquid supply means for supplying high-pressure liquid to the second processing head;
In the first station, the workpiece is irradiated with the laser beam by injecting the liquid from the first machining head to the workpiece along the planned cutting line of the workpiece and transmitting the laser beam into the liquid. Then, a groove is formed at the position of the planned cutting line on the surface of the workpiece,
In the second station, a liquid is sprayed from the second processing head to the workpiece along the groove to cause a crack to reach the back surface of the workpiece from the groove, thereby cutting the workpiece along the cutting line. The processing apparatus of the workpiece characterized by cleaving according to the above.

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