JP2004335930A - Method and device for cleaving wafer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To satisfactorily perform a cleavage in a manufacturing process in which a compound semiconductor wafer is chipped. <P>SOLUTION: A wafer cleaning device comprises a scribing mechanism 50 for scribing the wafer W; a wafer retention mechanism 20 that has a placement surface for placing the wafer W and retains the wafer W while one end projects outside the placement surface; a stress application mechanism 60 coming into contact with the projection site of the wafer W for pressing to apply bending stress; and flexible sheet materials 27 and 69 interposed between the placement surface and the wafer W, and between the stress application mechanism 60 and the wafer W, respectively. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for dividing a semiconductor wafer into chips, and more particularly to a method for cleaving a compound semiconductor.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, in a manufacturing process of chipping a compound semiconductor wafer used for a laser diode or the like, a technique of cleaving instead of dicing has been adopted. This cleavage is a method in which a scribe groove is formed in the plane of a wafer and the wafer is cut by applying a bending stress, and the cut surface is used for a light reflecting surface of a semiconductor laser or the like because a high flatness can be obtained. I have.
In the chipping manufacturing process by the cleavage, a pressure-sensitive adhesive film is attached to one surface of the wafer, cleaves are formed after forming a scribe groove, and then, the adhesive material of the pressure-sensitive adhesive film is cured by ultraviolet irradiation, and the adhesiveness is reduced. It has been common practice to peel off a chip that has been separated (see Patent Document 1).
Patent Document 2 discloses an apparatus that automates the above-described series of chip manufacturing processes and continuously cleaves the work to improve the efficiency of the operation.
[0003]
[Patent Document 1]
JP-A-5-217969
[Patent Document 2]
JP-A-11-284277
[0004]
[Problems to be solved by the invention]
In the conventional example described in Patent Document 1, even if the adhesive film is irradiated with ultraviolet light, the adhesive force does not necessarily completely disappear, so that the wafer and the film are connected to each other by a needle-like body or a convex body through the film. It was necessary to physically form a gap between them. However, in that case, the wafer may be deformed, and the thin and brittle material used for the compound semiconductor may deteriorate and hinder its characteristics.
Further, when peeled off from the film, the end faces come into contact with each other, and there is a possibility that the active face at the cleavage end face, which has an important function in a laser diode or the like, may be damaged, and this has been a cause of impairing the chip yield.
In addition, the conventional example described in Patent Document 2 has the above-mentioned disadvantages, and because the device pursues the efficiency of mass production, the size of the device also increases, which makes the device suitable for use in small-quantity production and experimental trial production. There was an inconvenience.
[0005]
An object of the present invention is to cleave well.
It is another object of the present invention to provide a cleavage device suitable for small-scale production.
[0006]
[Means for Solving the Problems]
The invention according to claim 1 is a cleaving method for scribing a wafer by applying a bending stress to the wafer and cleaving the wafer, wherein the wafer is supported in a cantilever state, and the surface on which the bending stress is applied and the opposite side are provided. A configuration is adopted in which a sheet material having flexibility is disposed on both surfaces, and bending stress is applied through the sheet material.
[0007]
In the above configuration, bending stress is applied to the free end side of the wafer supported on the cantilever, and at that time, sheet materials are arranged on both surfaces of the wafer. As described above, since the sheet material exists on both sides of the wafer, the cleaved and separated wafer is received and held by the sheet material, and thus does not need to be held by the adhesive sheet. Since there is no need for a peeling operation, no damage is caused on the cleavage plane of the wafer.
[0008]
According to a second aspect of the present invention, there is provided a scribing mechanism for scribing a wafer, a wafer holding mechanism having a mounting surface on which the wafer is mounted and holding the wafer with one end protruding outside the mounting surface. And a stress applying mechanism for applying a bending stress by contact-pressing a projecting portion of the wafer, and a flexible sheet material interposed between the mounting surface and the wafer and between the stress applying mechanism and the wafer. Is provided.
[0009]
In the above configuration, a scribe groove is formed in the wafer by the scribe mechanism. A scribe groove refers to a groove formed in advance to promote cleavage along a cleavage plane. Then, the wafer is held by the wafer holding mechanism after the scribe groove. The holding of the wafer may be performed before the formation of the scribe groove.
The wafer is held in a cantilever shape with one end protruding outside the mounting surface by the wafer holding mechanism, and the protruding portion is separated by cleavage. That is, bending stress is applied to the protruding portion of the wafer.
At this time, since the sheet material exists on both sides of the wafer, the wafer that has been cleaved and separated is received and held by the sheet material. For this reason, there is no need to hold the wafer with the adhesive sheet, and since there is no need to peel off the adhesive sheet, there is no damage to the cleavage plane of the wafer.
[0010]
A third aspect of the present invention has a configuration similar to that of the second aspect of the invention, and employs a configuration in which the scribe mechanism scribes a wafer held by the wafer holding mechanism.
In the above configuration, the same operation as that of the second aspect of the invention is performed, and the wafer is scribed and cleaved while being held by the wafer holding mechanism. Therefore, the work space can be saved.
[0011]
The invention according to claim 4 has the same configuration as the invention according to claim 2 or 3, and the sheet material has a non-adhesive and non-adhesive contact surface with the wafer, and a contact position with the wafer. It is configured to be changeable.
In the above configuration, the same operation as the invention according to claim 2 or 3 is achieved, and when cleavage is performed, the position of the sheet material is changed, and the portion used during the cleavage operation is shifted to an unused portion. Work can be done.
[0012]
A fifth aspect of the present invention has the same configuration as the second, third, or fourth aspect of the present invention, and abuts on one end of the wafer in a direction in which the wafer held by the wafer holding mechanism projects. A positioning member is provided for performing positioning with respect to the wafer, and the thickness of the tip of the positioning member that contacts the wafer is made smaller than the thickness of the wafer.
[0013]
The cleavage plane of the wafer depends on its use, but high flatness is required for a part of the cleavage plane. For this reason, it is necessary to prevent the occurrence of scratches or damage due to contact with such a portion. However, since the tip of the positioning member is set to be thinner than the wafer, it is difficult to position the wafer when positioning the wafer. Thus, the contact area can be reduced, and contact with the part to be protected can be avoided.
[0014]
The invention according to claim 6 has the same configuration as the invention according to claim 2, 3, 4, or 5, and performs positioning by abutting on the end of the wafer held by the wafer holding mechanism in the protruding direction. A configuration is employed in which a retracting mechanism is provided to separate the positioning member from the wafer when bending stress is applied by the stress applying mechanism.
With the above configuration, contact between the wafer and the positioning member during cleavage can be avoided.
[0015]
The invention according to claim 7 has the same configuration as the invention according to claim 2, 3, 4, 5 or 6, and has a corner at the end of the mounting surface of the wafer holding mechanism on the side of the wafer protruding, so that the stress is reduced. The applying mechanism is configured to apply a bending stress to the wafer along the ridgeline of the corner.
In the above configuration, cleavage is performed along the ridgeline of the corner of the mounting surface of the wafer holding mechanism. At this time, since the sheet material is interposed between the wafer and the mounting surface, the elasticity of the sheet material The wafer is deformed into an arc shape and cleaved.
[0016]
The invention according to claim 8 has the same configuration as the invention according to any one of claims 2 to 7, and the scribe mechanism has a scribe groove on one end side in the direction in which the cleavage plane of the wafer is formed. In addition, the stress applying mechanism applies a bending stress to the wafer at the end on the side where the scribe groove is formed before the other end.
Usually, at the time of cleavage, separation starts from the scribe groove, but in the above configuration, the stress applying mechanism positively applies bending stress from the scribe groove, thereby further promoting separation from the scribe groove and facilitating cleavage. It is possible to do.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
(Overall Configuration of Embodiment)
Hereinafter, an embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a perspective view showing the overall configuration of a wafer cleavage apparatus 10 according to the present embodiment.
The wafer cleaving apparatus 10 includes a base 11 on which each component is provided, a wafer set stage 20 on which a wafer W to be cleaved is arranged, and a cleavage of the wafer W arranged on the wafer set stage 20. A separation width setting mechanism 30 for positioning the leading end to be separated, a Y stage 40 for moving and positioning the wafer set stage 20 along a Y-axis direction described later, and a scribe for scribing the wafer W disposed on the base 11. A mechanism 50, a breaker mechanism 60 that cleaves the wafer W disposed on the Y stage 40, and an operation control unit 100 that controls the operations of the above components are provided.
Hereinafter, each configuration will be described in detail.
[0018]
(Base)
The base 11 has an upper surface formed of a uniform flat surface, and the components of the wafer cleavage device 10 are directly or indirectly fixedly mounted on the flat surface.
Here, in the following description, one direction parallel to the upper flat surface of the base 11 is defined as an X-axis direction, and a direction parallel to the flat surface and orthogonal to the X-axis direction is defined as a Y-axis direction.
[0019]
(Y stage)
As shown in FIG. 1, the Y stage 40 includes a stage plate 41 on which the wafer set stage 20, the separation width setting mechanism 30 and the breaker mechanism 60 are installed, and a stage plate 41 parallel to the upper surface of the base 11. , A slide table 42 movably supporting the slide table 42 in the Y-axis direction, a micrometer-type adjuster 43 for manually inputting a movement positioning operation of the slide table 42 in the Y-axis direction, and an upright stand on the upper surface of the stage plate 41. And a wafer setting table 44 for supporting the wafer setting stage 20.
[0020]
(Wafer set stage)
As shown in FIGS. 2 and 3, the wafer setting stage 20 performs the cleavage of a wafer table 21 supported on the wafer table 44 in parallel with the base 11 and the cleavage of the wafer W placed on the wafer table 21. A push plate 23 for positioning an end opposite to the end to be pressed, and a screw for screwing the side wall 21 b provided on the wafer stand 21 in an X-axis direction and holding the push plate 23. A shaft 24, a knob 25 for rotating the screw shaft 24 in the X-axis direction by rotating the screw shaft 24, a pressing spring 26 for applying a pressing force to the pressing plate 23 toward the wafer W, and a cloth on the upper surface of the wafer table 21. A first film sheet 27 interposed between the wafer W and the wafer table 21 and a wafer pressing mechanism 28 (see FIG. 3B) that presses and holds the wafer W on the wafer table 21 from above. Have.
[0021]
The wafer table 21 is a rectangular flat plate having two sides arranged in the X-axis direction and the other two sides arranged in the Y-axis direction. Side walls 21a, 21b and 21c are provided upright at both ends in the Y-axis direction and one end in the X-axis direction, respectively.
One side wall 21a along the X-axis direction has a function of contacting one end of the wafer W in the Y-axis direction and positioning the wafer W in the Y-axis direction.
The other side wall 21c along the X-axis direction has a slit for pressing the other end in the Y-axis direction of the wafer W and inserting a pressing plate 22 for holding the holding state between the other side wall 21a. Is provided. Thereby, the positioning of the wafer W in the Y-axis direction can be reliably performed.
The side wall 21b along the Y-axis direction supports the above-described screw shaft 24 by a screw hole penetrating along the X-axis direction, and has a slit formed below the screw shaft 24 along the X-axis direction. This slit is for inserting the first film sheet 27 laid on the upper surface of the wafer table 21.
Then, the first film sheet 27 is laid on the upper surface of the wafer table 21 in a state where the first film sheet 27 is inserted into the slit provided in the side wall 21b, so that the first film sheet 27 can be moved along the X-axis direction. I have.
[0022]
Further, the wafer stage 21 has no side wall only at the other end in the X-axis direction. The wafer W is fed out from the end, and one end of the wafer W is cleaved at a width corresponding to the feeding amount. Are separated by This amount of extension is the cavity length of the semiconductor laser chip. In order to cleave, the pay-out end portion of the wafer W of the wafer table 21 has a vertical end surface along the Y-axis direction, and serves as a boundary between the vertical end surface and the upper surface on which the wafer W is placed. Cleavage is performed along the Y-axis direction by a ridge line (edge) 21d along the Y-axis direction and pressing from above by a breaker mechanism 60 described later.
[0023]
The first film sheet 27 is a flexible or elastic sheet material. Further, the first film sheet 27 has a band shape having a width smaller than the interval between the side walls 21 a and 21 c of the wafer table 21. It is desirable that the material be at least softer than the wafer W in order to protect the wafer W separated by cleavage. For example, a resin material is suitable.
[0024]
The push plate 23, the screw shaft 24, the knob 25, and the pressing spring 26 are used to press the abutting plate 31 of the separation width setting mechanism 30, which will be described later, on the payout side end of the wafer W to position the wafer W in the X-axis direction. Configuration.
That is, the push plate 23 is provided at the tip of the screw shaft 24 via the pressing spring 26, and the screw shaft 24 moves in the X-axis direction by rotating the knob 25. Accordingly, the pressing plate 23 is brought into contact with the wafer W by the rotation operation of the knob 25, and is further moved, so that the pressing spring 26 is compressed, and a pressing force in the feeding direction is applied to the wafer W according to the amount of movement. . As a result, the payout side end of the wafer W comes into contact with the tip of the butting plate 31, and the wafer W is sandwiched between the butting plate 31 and the pressing plate 23, and is located at an appropriate position in the X-axis direction. The wafer W is positioned.
Note that an active surface of the laser diode is formed near each upper surface of each end surface of both ends in the X-axis direction of the wafer W. It is necessary to avoid external contact, since even a small damage to this active surface can reduce its reliability. Therefore, the pressing plate 23 has a substantially U-shaped flat plate shape to reduce the contact area, and the tip of the pressing plate 23 is set to be thinner than the wafer W. The structure is such that it contacts only the lower part of the end face of the wafer W. As an example of the thickness of the tip of the push plate 23, the thickness of the tip of the push plate 23 is set to 100 [μm] with respect to the thickness of 150 [μm] of the wafer W. Of course, it may be thinner.
[0025]
As shown in FIG. 3, the wafer holding mechanism 28 is fixedly connected to one end of the support shaft 46 rotatably supported on the wafer table 21 along the Y-axis direction, and rotates. A holding arm 45, a tension spring 48 for applying a turning force in both the holding direction and the retreating direction of the wafer W by the holding arm 45, and a fixed connection to the other end of the support shaft 46 via the support shaft 46. A knob 47 for inputting a rotational force in the holding direction and the retreating direction to the holding arm 45 and an air cylinder 49 for locking the holding arm 45 in the retracted state are provided.
[0026]
The holding member 45a is provided with a holding member 45a at a rotating end thereof. The holding member 45a presses the upper surface of the wafer W by turning in the holding direction, and holds the wafer W at a predetermined position. The pressing force at this time is urged by the tension spring 48.
The tension spring 48 is connected to a spring hook 39 provided on the holding arm 45, and the holding state of the holding arm 45 (the solid line state in FIG. 3B: the state where the holding arm 45 extends in the horizontal direction) and the retracted state (FIG. 3). (The state indicated by the dotted line in (B): the state in which the holding arm 45 extends in the vertical direction) is engaged with the spring hook 39 so that the state in which the elastic force urging the rotation to each state is applied is switched. ing. Therefore, when the holding arm 45 is rotated to the holding state side from the intermediate position by the knob 47, the holding arm 45 is urged to rotate in the holding direction by the elastic force of the tension spring 48, and conversely, When the holding arm 45 is rotated to the retreat state side from the position, the holding force of the holding arm 45 is urged in the evacuation direction by the elastic force of the tension spring 48.
[0027]
The air cylinder 49 operates under the control of the operation control means 100. The air cylinder 49 is arranged such that the movable portion protruding during operation comes into contact with the end of the holding arm 45 in the holding state opposite to the pressing end. Then, the holding arm 45 is forcibly turned in the evacuation direction and restricts the turning from the evacuation state to the pressed state.
[0028]
(Separation width setting mechanism)
The separation width setting mechanism 30 includes an abutting plate 31 that abuts on the unloading side end when the wafer W on the wafer table 21 has been unwound by a predetermined amount, and holds the abutting plate 31 and has a center in the Y-axis direction. And an air cylinder 35 for applying a swinging power to the swinging body 34 in a direction in which the contact end of the abutment plate 31 is retracted below the height of the upper surface of the wafer table 21. A first X stage 32 for coarsely positioning the butting plate 31 in the X-axis direction, and a second X stage 33 for finely positioning the butting plate 31 in the X-axis direction.
[0029]
The second X stage 33 has a micrometer-type adjuster that mounts and holds the butting plate 31, the oscillator 34, and the air cylinder 35 and manually inputs a movement positioning operation in the X-axis direction. That is, by the manual input operation of the adjuster, the tip end position of the abutment plate 31 supported by the rocking body 34 is positioned so as to come into contact with the tip end surface of the wafer W fed out by the target amount. In addition, the adjuster of the second X stage 33 is set so that the amount of movement in the X-axis direction with respect to the input operation amount is smaller than that of the first X stage 32, and is finer than that of the first X stage 32. It is possible to perform positioning.
[0030]
The first X stage 32 is provided on the stage plate 41 of the Y stage 40. The first X stage 32 holds and holds the second X stage 33, and is a micrometer type adjustment for manually inputting a movement positioning operation in the X-axis direction. It has a vessel. That is, by the manual input operation of this adjuster, fine positioning of the tip end position of the abutment plate 31 is performed via the second X stage 33.
[0031]
The swing body 34 is swingably supported on a second X stage 33 by a support shaft extending in the Y-axis direction, and holds the abutment plate 31 below the swing body 34. Further, the swing body 34 has a contact portion that comes into contact with the distal end portion of the movable portion of the air cylinder 35, and also has a spring (not shown) that urges the swing in the contact direction. In addition, when the abutting portion of the rocking body 34 is in contact with the tip of the air cylinder 35 in which the movable portion is in the retracted state, the abutment plate 31 is in a horizontal state, and The lower surface height is equal to the upper surface height of the wafer table 21, and the front end of the abutment plate 31 can be brought into contact with the front end surface of the payout side end of the wafer W. Then, when the movable portion of the air cylinder 35 projects from this state, the swinging body 34 swings, and accordingly, the tip of the abutment plate 31 retreats to a position lower than the height of the upper surface of the wafer table 21.
[0032]
The tip of the butting plate 31 is formed, for example, in a wedge shape so as to be thinner than the wafer W. The structure is such that it contacts only the lower part of the end face of the wafer W. As an example of the thickness of the tip of the push plate 23, the thickness of the tip of the push plate 23 is set to 100 [μm] with respect to the thickness of 150 [μm] of the wafer W. Of course, it may be thinner. Thus, at least the active layer on the cleavage plane of the wafer W can be protected.
[0033]
(Scribe mechanism)
FIG. 5 is a side view mainly showing a scribe mechanism 50 of the wafer cleavage apparatus 10.
The scribing mechanism 50 includes a scriber 53 that forms a groove on the upper surface of the wafer W, a scribe arm 54 that is swingably supported around the X-axis direction that supports the scriber 53 at its tip, and a swing of the scribe arm 54. An air cylinder 55 for applying power, a scribing Y-stage 52 for mounting and holding these components 53, 54, 55 and moving the scriber 53 by a predetermined distance in the Y-axis direction for scribing; And a main Y stage 51 that is provided on the main surface 11 and moves or retracts the scribe Y stage 52 toward the wafer set stage 20 along the Y axis direction.
[0034]
The main Y stage 51 is arranged at a position adjacent to the wafer set stage 20 in the Y axis direction. The main Y stage 51 has a stage plate on the upper part, and a scribe Y stage 52 is mounted on the stage plate. The stage plate is moved and retracted by an air cylinder. The air cylinder sends the stage plate to the wafer set stage 20 side or retracts it. At the time of sending, the scriber 53 at the tip of the scribe arm 54 moves the scribing Y-stage 52 to a position above the wafer W on the wafer table 21, and at the time of evacuation, hinders the cleavage operation. The movement range is set so that the scribe arm 54 is moved to a position where the scribe arm 54 is completely retracted from above the wafer table 21 so as not to be caused.
[0035]
The scribing Y stage 52 has a stage plate on the top, and a scriber 53, a scribe arm 54, and an air cylinder 55 are mounted on the stage plate. The stage plate is moved by an air cylinder. This air cylinder moves the stage plate along the Y-axis direction.
When the main Y stage 51 is sent out, the scriber 53 at the tip of the scribe arm 54 scribes the wafer W on the wafer table 21 to a position above and in the vicinity of one end near the scribe mechanism 50 in the Y-axis direction of the wafer W on the wafer table 21. The Y stage 52 is moved. The scribing Y-stage 52 moves the scriber 53 in the direction of pushing the wafer toward the wafer set stage 20, and performs scribing.
The scribing Y-stage 52 includes a micrometer-type fine movement adjuster 56 for setting a groove forming distance at the time of scribing. The fine movement adjuster 56 regulates the amount of movement of the stage plate at the time of scribing within the range of the distance d in FIG. 5 according to the amount of rotation of the operation dial. That is, a scribe groove having the same length as the distance d is formed in the wafer W.
[0036]
The scribe arm 54 is disposed along the Y-axis direction, and is supported at an intermediate position in the longitudinal direction so as to be swingable about the X-axis direction. A scriber 53 is provided at one end of the scribe arm 54 on the side of the wafer set stage 20 in a state where the scriber 53 is directed downward, and a movable portion of the air cylinder 55 comes into contact with the other end from above. I have. The air cylinder 55 allows its movable part to retreat upward from the state shown in FIG. On the other hand, the end of the scribe arm 54 provided with the scriber 53 is set to be heavy (for example, a tip load of 10 [gf] (9.8 [mN])), whereby the movable portion of the air cylinder 55 is moved upward. As a result, the scriber 53 pierces the upper surface of the wafer W. Then, scribe grooves are formed on the upper surface of the wafer W by the operation of the scribe Y stage 52 described above. As a material of the scriber 53, for example, a diamond scriber or the like is used.
A load adjusting screw 54a is provided at the end of the scribe arm 54 on the air cylinder 55 side, and the amount of load generated on the scriber 53 can be adjusted by rotating the load adjusting screw 54a.
[0037]
(Breaker mechanism)
FIG. 6A is a plan view of the breaker mechanism 60, and FIG. 6B is a front view.
The breaker mechanism 60 has a U-shaped pressing arm 64 having a wafer pressing portion 65 for pressing the wafer W on the wafer table 21 from above at the time of cleavage, and a breaker plate 62 having a pusher 61 for applying stress to the wafer W to promote cleavage. A swing support 63 for swingably supporting the breaker plate 62 and the holding arm 64 on the stage plate 41 about the Y-axis direction; an air cylinder 67 for imparting a swing operation to the breaker plate 62; 61 and a second film sheet 69 that covers the front end of the wafer holding section 65.
[0038]
The holding arm 64 is swingably supported by the same support shaft as the breaker plate 62 at the end on the opening side of the U-shape. Further, a flat wafer holding portion 65 is provided on the swing end side of the holding arm 64. The wafer holding section 65 is held by a holding arm 64 such that the tip end on the wafer W side is parallel to the Y-axis direction. The width of the wafer holding portion 65 in the Y-axis direction is set wider than that of the wafer W, and the tip end surface of the wafer holding portion 65 abuts on the upper surface of the wafer W due to the swing of the holding arm 64 during cleavage. The pressing member 65 is in contact with the uppermost position of the upper end of the wafer table 21 at the end of the wafer feeding side.
A guide frame 66 through which the second film sheet 69 is inserted is provided on the plane of the wafer holding section 65. That is, a gap is provided between the guide frame 66 and the wafer holding portion 65, and the second film sheet 69 is inserted through the gap.
[0039]
Further, in the vicinity of the base end portion of the holding arm 64, a tension spring 68 for urging the wafer W side to swing, and a regulation for regulating the preceding swing angle with respect to the breaker plate 62 so as not to be a predetermined value or more. A shaft 70 is provided.
That is, while the holding arm 64 is constantly urged to swing toward the wafer W by the tension spring 68, the regulating shaft 70 comes into contact with the upper surface of the breaker plate 62 so that the advance swing angle with respect to the breaker plate 62 is increased. Is regulated so as not to exceed a certain level.
[0040]
The breaker plate 62 is located inside the U-shape of the holding arm 64, and a wedge-shaped pusher 61 is provided at the swing end of the breaker plate 62 toward the wafer W. The pusher 61 is held by a breaker plate 62 so that the tip end on the wafer W side is parallel to the Y-axis direction. The width of the pusher 61 in the Y-axis direction is set to be wider than that of the wafer W, and the tip surface of the pusher 61 contacts the upper surface of the wafer W due to the swing of the breaker plate 62 during cleavage. Further, the pusher 61 is held by the breaker plate 62 so as to abut on the upper surface of the wafer W at a position almost directly above the ridge line 21d of the wafer table 21 and slightly near the wafer feeding side. That is, the pusher 61 and the wafer pressing portion 65 abut on the upper surface of the wafer W in a state of being adjacent to each other with the ridgeline 21d as a boundary.
[0041]
The breaker plate 62 is connected at its base end to the distal end of the movable portion of the air cylinder 67, and the movable portion performs a protruding operation, so that the breaker plate 62 generates a swinging power toward the wafer W. Will be granted. The base end of the air cylinder 67 is swingably supported on the stage plate 41 about the Y-axis direction, and can follow the swing of the breaker plate 62.
When the breaker plate 62 swings toward the wafer W, the holding arm 64 that comes into contact with the control shaft 70 also swings. At this time, the position of the regulating shaft 70 is set such that the wafer pressing portion 65 reaches the upper surface of the wafer W prior to the pusher 61.
In addition, since the wafer W is separated from the scribe groove provided at one end in the Y-axis direction of the wafer W at the time of cleavage, in order to promote this, the tip of the pusher 61 is placed on the scribe groove side. May be provided such that the end to be contacted with the wafer W first.
[0042]
Further, a slit is formed between the breaker plate 62 and the pusher 61 along the Y-axis direction. This slit is for inserting the second film sheet 69. That is, the second film sheet 69 is inserted into the guide frame 66 provided in the above-described wafer holding unit 65, covers the front end of the wafer holding unit 65 and the pusher 61, and is further inserted into the slit. Will be equipped. And by equipping in such a state, the position of the second film sheet 69 can be moved along the direction inserted into the guide frame 66 and the slit, and the contact position with the wafer W can be changed. It is possible.
[0043]
The second film sheet 69 is a flexible or elastic sheet material. Further, the second film sheet 69 has a band shape having a width wider than at least the width of the wafer W in the Y-axis direction. It is desirable that the material be at least softer than the wafer W in order to protect the wafer W. For example, a resin material is suitable.
[0044]
(Operation control means)
The operation control means 100 will be described with reference to FIG. FIG. 7 is a block diagram showing a control system of the wafer cleavage device 10.
The operation control means 100 receives a solenoid valve driver 103 for controlling the operation of the solenoid valves 121 to 126 corresponding to each air cylinder and detection signals from various sensors 111 to 115 to be described later and converts them into digital signals. And a sensor interface 102.
[0045]
The solenoid valve 121 operates an air cylinder that drives the main Y stage 51, the solenoid valve 122 operates an air cylinder 55 that moves the scriber 53 up and down, and the solenoid valve 123 operates an air cylinder that drives the scribe Y stage 52. , The solenoid valve 124 operates the air cylinder 67 for performing the breaker operation of the breaker mechanism 60, and the solenoid valve 125 operates the air cylinder 35 for retracting and returning the abutting plate 31. The valve 126 operates the air cylinder 49 for restricting the swing of the holding arm 45 of the wafer W.
[0046]
The sensor 111 detects that the holding arm 45 of the wafer W has shifted from the retracted state to the holding state. The sensor 112 detects that the main Y stage 51 has moved to the wafer set stage 20 side to the target position in the scribe operation. The sensor 113 detects that the scriber 53 has descended to the target descending position in the scribing operation, and the sensor 114 detects that the main Y stage 51 has retreated to the prescribed retract position. The sensor 115 is a sensor that determines the timing for retracting the butting plate 31 from the swing position of the holding arm 64 in the breaker operation.
[0047]
Further, the operation control means 100 includes a ROM (not shown) in which control programs and control data for executing various functions and operations of the wafer cleaving device 10 described later are written, and each air cylinder in accordance with the control programs by detecting each sensor. A central processing unit (CPU) 101 for centrally controlling the operation of each unit such as an electromagnetic valve for switching the operation of the CPU, and a RAM (not shown) for storing various data such as processing data of the CPU 101 in a work area.
Further, the operation control means 100 is provided with an input panel 104 provided with a start button for inputting the start of various operations, and a display unit 105 for displaying an operation state.
[0048]
(Operation explanation of wafer cleavage device)
The wafer cleavage device 10 having the above configuration will be described with reference to FIGS. FIG. 8 is a view for explaining the operation of the wafer cleavage apparatus 10, and FIGS. 9 and 10 are flowcharts showing the operation of the wafer cleavage apparatus.
First, when the main power supply of the apparatus 10 is turned on, the CPU 101 is initialized, the state of each part is determined by the sensors 111 to 115 via the sensor interface 102, and each cylinder is moved to the initial position via each solenoid valve driver 103. (Step S1).
[0049]
Next, the wafer W is set on the wafer stage 21 of the wafer setting stage 20 via the first film sheet 27. At this time, positioning is performed in the Y-axis direction so that the wafer W is held between the side wall 21a and the pressing plate 22.
Then, the abutment plate 31 is positioned in the X-axis direction so that the cleavage is performed at a predetermined width from the wafer W. That is, coarse positioning is performed by the first X stage 32 and fine positioning is performed by the second X stage 33. Then, the push plate 23 is brought into contact with the wafer W by operating the knob 25 in order to bring the wafer W into good contact with the butting plate 31. At this time, an indicator may be provided so that the pressing force by the push plate 23 is constant. When the wafer W is circular, the wafer W may be brought into contact with the original flat surface. Further, since the space above the wafer table 21 is vacant, the wafer W may be observed from above using a stereoscopic microscope or a camera. Further, as for the setting on the wafer table 21, it is also possible to set according to the pattern of the wafer (step S2).
[0050]
Next, the knob 47 is operated to press and hold the wafer W by the pressing arm 45 (step S3). As a result, the wafer W is held on the mounting surface of the wafer table 21.
Then, when a start signal is input from the input panel 104 by the start button, the process first proceeds to a scribe operation (step S4).
At this time, the pressing arm 45 is separated from the sensor 111, and the CPU 101 confirms that the pressing of the wafer W is performed by the pressing arm 45. If the separated state of the pressing arm 45 is not recognized, the process proceeds to step S3. And the process does not shift to the scribe operation until the wafer is pressed (step S5).
[0051]
When shifting to the scribe operation, first, the solenoid valve 121 is controlled by the CPU 101, and the air cylinder of the main Y stage 51 of the scribe mechanism 50 drives the scribe Y stage 52 toward the wafer set stage 20 (step S6). The stop position is adjusted in advance by the adjustment mechanism 57 of the main Y stage 51 so that the scriber 53 becomes the scribe start position of the wafer W, and the sensor 112 detects that the scriber 53 has moved to the moving distance. (Step S7: state in FIG. 8A).
[0052]
Next, the solenoid valve 122 is controlled by the CPU 101, the air cylinder 55 of the scribe mechanism 50 is operated, and the end of the scribe arm 53 on the scriber 53 side is lowered by swinging (step S8). The lowering of the scriber 53 is detected by the sensor 113 (step S9). Thus, the tip of the scriber 53 penetrates to a predetermined depth of the wafer W.
[0053]
Next, the solenoid valve 123 is controlled by the CPU 101, and the air cylinder of the scribe Y stage 52 of the scribe mechanism 50 moves the scribe arm 54 and the scriber 53 along the Y-axis direction (step S10). The stop position is adjusted in advance by the fine movement adjuster 56, and the movement distance becomes the scribe groove length. By such an operation, a scribe groove is formed in the wafer W (the state of FIG. 8B).
[0054]
After the groove is formed, the CPU 101 operates the air cylinder 55 by the solenoid valve 122 to raise the scriber 53 by the swing of the scribe arm 54 (step S11). Then, the CPU 101 returns the scribing Y stage 52 and the main Y stage 51 to the original positions via the solenoid valves 121 and 123 (step S12).
[0055]
When the return state of the main Y stage 51 is detected by the sensor 114, the CPU 101 waits for an input of a breaker start button from the input panel 104 (Step S14). When the input is detected, the CPU 101 applies a breaker to the wafer (bending stress). Start operation.
That is, the solenoid valve 124 is controlled by the CPU 101, and the air cylinder 67 of the breaker mechanism 60 swings the holding arm 64 and the breaker plate 62 toward the wafer W (step S15). At this time, the tip side of the wafer holding portion 65 and the pusher 61 is in a state of being covered with the second film sheet 69, and the sheet 69 is slid so that an unused portion is moved to the tip of the wafer holding portion 65 and the pusher 61. It is in contact with the position.
[0056]
Further, when the holding arm 64 and the breaker plate 62 swing, the front end of the wafer holding portion 65 arranged ahead comes into contact with the upper surface of the wafer W, and the upper surface of the wafer W is pressed by the tension spring 68 with an appropriate pressing force. (State of FIG. 8C). When the start of pressurization by the presser arm 64 is detected by the sensor 115 based on the position of the presser arm 64 (step S16), the CPU 101 operates the air cylinder 35 by controlling the solenoid valve 125, and The unit is swung in the direction in which it moves downward and retracted (step S17). Then, at this time, the leading end of the abutment plate 31 moves in a direction away from the end surface of the wafer W, so that sliding with the end surface of the wafer W does not occur, so that the leading end surface of the wafer W is protected.
[0057]
Further, as the breaker plate 62 swings, the pusher 61 contacts the upper surface of the wafer. Further, when the pusher 61 is pushed in, the wafer W is cleaved from the scribe groove along the ridge line 21d of the wafer table 21 due to the bending stress, and the projecting portion of the wafer W is separated (the state of FIG. 8D). At this time, since the first film sheet 27 is disposed below the wafer W, the wafer W is deformed in an arc shape by the elastic bending of the first film sheet 27 at the ridge line 21d of the wafer table 21. Cleavage occurs when a certain curvature is reached.
In addition, the effect of always making the quality of the cleavage plane and the width of the separated wafer W uniform by the scribe groove can be obtained. At this time, the tip position of the pusher 61 is set so as to pass on the near side (right side in FIG. 8) just below the ridgeline 21 d of the wafer table 21, but the quality of the cleavage plane and the quality of the separated wafer W The effect of making the width uniform at all times is further improved by bringing the position where the pusher 61 contacts the wafer W closer to the scribe groove.
[0058]
The separated wafer W moves toward the retracted butting plate 31 and is held between the first film sheet 27 and the second film sheet 69.
Then, when the breaker operation is completed, the CPU 101 operates the air cylinder 67 in the retreating direction by the solenoid valve 124, and swings the holding arm 64 and the breaker plate 62 in the up-and-down direction (step S18). Further, the second film sheet 69 also retreats together with the holding arm 64 and the breaker plate 62, so that the separated wafer W becomes free.
Then, the separated wafer W is collected (Step S19). At this time, a picker for collection may be provided to automatically perform collection.
[0059]
Then, after the reset (Step S20), the CPU 101 operates the air cylinder 35 via the solenoid valve 125, and the butting plate 31 is returned to the original position (Step S21). Further, the air cylinder 49 is operated via the solenoid valve 126, and the pressing arm 45 is swung in the pressing releasing direction (step S22).
Thereafter, when a new cleavage is performed, the operation from step S1 is repeated, and when no cleavage is performed, the process ends.
[0060]
(Effect of wafer cleavage device)
Since the wafer cleavage device 10 performs the breaker operation in a state where the first film sheet 27 and the second film sheet 69 are arranged on both sides of the wafer W, each of the sheet materials 27 and 69 separates the separated wafer W. Since the holding and the pressure-sensitive adhesive sheet are not required, the peeling operation is not required, and the operation can be facilitated. In addition, it is possible to effectively suppress damage to the cleavage surface of the wafer due to the peeling operation, and it is not necessary to use an ultraviolet irradiation device or the like for peeling off the adhesive, so that the size of the device can be simplified. it can.
[0061]
Further, the first film sheet 27 having flexibility can have a width in a range in which the wafer W is deformed by bending stress, and the surface where cleavage should occur and the direction in which bending occurs are strictly one. It is possible to satisfactorily cleave even in a state where it is not cut.
Further, since the wafer pressing portion 65 and the pusher 62 are in contact with each other via the second film sheet 69, the surface of the wafer W can be protected.
Further, since both the scribe operation and the breaker operation are performed on the wafer set stage 20, both operations can be performed continuously, thereby speeding up the operation and reducing the size of the apparatus by saving space. Becomes possible.
[0062]
(Other)
Although an air cylinder is mainly used as an actuator that performs various operations, the actuator is not limited to this, and a motor, an electromagnetic solenoid, or the like may be used. Also, by using a motor, each parameter may be digitized and automatically input.
In addition, a camera as an imaging unit may be provided to perform positioning and position correction of each unit using image processing.
[0063]
In addition, a known film feeder device for changing the position of the first film sheet 27 and the second film sheet 69 may be provided once or at a specified number of operations. Further, this may be automatically controlled by the operation control means 80.
For setting and unloading of the wafer W, loading and unloading may be automated using a pickup mechanism such as a vacuum nozzle.
[0064]
Further, the wafer holding unit 65 or the pusher 61 is configured to perform a breaker operation by drawing a locus on an arc by swinging, but any of these may perform the breaker operation by a direct movement type movement.
Further, the wafer holding portion 65 and the pusher 61 may be individually finely controlled by an actuator to improve the workability with respect to the material of the wafer and the like.
[0065]
In the present embodiment, the rod-shaped cutout is performed on the wafer W. However, the present invention is not limited to this. For example, it goes without saying that the wafer cleaving apparatus 10 may be used for cleaving when the rod-shaped wafer W separated this time is further divided into chips.
[0066]
【The invention's effect】
According to the first aspect of the present invention, since the cleavage is performed in a state where the sheet material is arranged on both sides of the wafer, the cleaved and separated wafer is received and held by the sheet material. Since it is not necessary to hold the wafer with an adhesive sheet and it is not necessary to remove the adhesive sheet from the adhesive sheet, damage to the cleavage surface of the wafer can be effectively suppressed. Therefore, by suppressing such damage, it is possible to improve the yield of semiconductor chips using a wafer.
[0067]
According to the second aspect of the present invention, since the cleavage is performed in a state in which the sheet material is arranged on both sides of the wafer, the sheet material holds the wafer, and the conventional adhesive sheet is unnecessary, so that the wafer is removed by the peeling operation. Damage to the cleavage plane can be effectively suppressed. Therefore, by suppressing such damage, it is possible to improve the yield of semiconductor chips using a wafer.
Furthermore, it is possible to provide a width in a range in which the flexible sheet material is deformed by bending stress, so that even when the surface where cleavage should originally occur and the direction in which bending occurs do not exactly match, it can be favorably performed. Cleavage can be performed. Therefore, fine positioning of the wafer is not required, and it is possible to effectively reduce cleavage errors and improve the working efficiency.
[0068]
According to the third aspect of the invention, since the wafer is scribed and cleaved while being held by the wafer holding mechanism, the working space can be saved and the apparatus can be downsized. Further, in the case of trial production or small-volume production, by performing a plurality of operations at the same location, operations such as movement and transport of the object to be processed can be omitted, and production can be performed more efficiently.
[0069]
According to the fourth aspect of the present invention, when the cleavage is performed, the position of the sheet material is changed, and the work used in the cleavage work can be shifted to an unused place. Alternatively, even when dust adheres, the next operation can be performed with a new part, and the effects of deterioration and dust can be avoided.
[0070]
According to the fifth aspect of the present invention, by setting the tip of the positioning member to be thin, it is possible to reduce the contact area when positioning the wafer, and to avoid contact with the portion to be protected. Therefore, it is possible to effectively maintain the high flatness of the portion to be protected.
[0071]
In the invention according to claim 6, since the positioning member is separated from the wafer at the time of cleavage, contact between the wafer and the positioning member at the time of cleavage can be avoided, and scratches and damage to the wafer can be effectively avoided. It becomes.
[0072]
According to a seventh aspect of the present invention, when the cleavage is performed along the ridgeline of the corner of the mounting surface of the wafer holding mechanism, the flexible sheet material is provided in a direction in which the wafer is bent, The wafer is also deformed in an arc shape according to the elasticity of the sheet material itself. For this reason, it is possible to provide a width in a range in which deformation occurs, and it is possible to satisfactorily cleave even in a state in which the surface where cleavage should originally occur and the direction in which bending occurs do not exactly match.
[0073]
In the invention according to claim 8, since the stress applying mechanism positively applies bending stress from the scribe groove, separation from the scribe groove is further promoted, and cleavage can be smoothly and efficiently ground. .
[Brief description of the drawings]
FIG. 1 is a perspective view showing an overall configuration of a wafer cleavage apparatus according to an embodiment of the present invention.
FIG. 2A is a plan view of the wafer setting stage disclosed in FIG. 1 with a part thereof omitted, and FIG. 2B is a front view of the wafer setting stage with a part omitted.
FIG. 3A is a plan view in which a wafer holding mechanism is added to the wafer setting stage disclosed in FIG. 2, and FIG. 3B is viewed from an arrow S direction in FIG. 3A. 2 shows a wafer set stage that has been set.
FIG. 4 (A) is a partially omitted plan view of the separation width setting mechanism disclosed in FIG. 1, and FIG. 4 (B) is a front view thereof.
FIG. 5 is a view of the scribe mechanism disclosed in FIG. 1 as viewed from the X-axis direction.
6 (A) is a plan view of the breaker mechanism disclosed in FIG. 1, and FIG. 6 (B) is a front view thereof.
FIG. 7 is a block diagram showing a control system of the wafer cleavage device.
FIGS. 8A and 8B are explanatory views showing various operations of the wafer cleavage apparatus. FIG. 8A shows a start of a scribe operation, FIG. 8B shows a scribe operation, and FIG. FIG. 8D shows the start of the operation, and FIG.
FIG. 9 is an operation flowchart showing various operations of the wafer cleavage device.
FIG. 10 is a flowchart of the operation following FIG. 9 showing various operations of the wafer cleavage device.
[Explanation of symbols]
10 Wafer cleavage device
20 Wafer set stage (wafer holding mechanism)
21d ridgeline
27 First film sheet (sheet material)
31 Abutment plate (positioning member)
34 Oscillator (evacuation mechanism)
35 Air cylinder (evacuation mechanism)
50 scribe mechanism
60 Breaker mechanism (stress applying mechanism)
69 Second film sheet (sheet material)
W wafer

Claims (8)

A cleavage method that cleaves the wafer and applies a bending stress to cleave the wafer,
Supporting the wafer in a cantilever state and disposing a sheet material having flexibility on both the surface that applies the bending stress and the surface on the opposite side,
A method of cleaving a wafer, wherein a bending stress is applied through the sheet material. A scribing mechanism for scribing the wafer,
A wafer holding mechanism that includes a mounting surface for mounting the wafer and holds the wafer in a state where one end protrudes outside the mounting surface,
A stress applying mechanism for applying a bending stress by contact-pressing the projecting portion of the wafer,
A wafer cleavage device comprising a flexible sheet material interposed between the placement surface and the wafer and between the stress applying mechanism and the wafer. 3. The apparatus according to claim 2, wherein the scribing mechanism scribes the wafer held by the wafer holding mechanism. The wafer according to claim 2, wherein the sheet material has a non-adhesive and non-adhesive contact surface with the wafer, and is provided so as to be capable of changing a contact position with the wafer. Cleavage device. A positioning member that performs positioning by contacting any one end of the wafer in a direction in which the wafer held by the wafer holding mechanism protrudes;
5. The wafer cleaving apparatus according to claim 2, wherein a thickness of a tip portion of the positioning member abutting on the wafer is smaller than a thickness of the wafer. A retracting mechanism is provided for separating a positioning member that performs positioning by contacting an end of the wafer held by the wafer holding mechanism in a protruding direction when the bending stress is applied by the stress applying mechanism. An apparatus for cleaving a wafer according to claim 2, 3, 4, or 5. A corner portion is provided at an end portion of the mounting surface of the wafer holding mechanism on a wafer protruding side,
The wafer cleaving device according to claim 2, wherein the stress applying mechanism applies a bending stress to the wafer along a ridgeline of the corner. The scribe mechanism forms a scribe groove at one end in a direction in which a cleavage plane of the wafer is formed,
8. The stress applying mechanism according to claim 2, wherein an end on the side where the scribe groove is formed is applied to the wafer with a bending stress prior to the other end. 9. A device for cleaving a wafer according to claim 1.

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