JP2012182280A - Method for processing wafer, and hard plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to readily remove a hard plate stuck to a front face of a wafer therefrom after grinding a backside of the wafer.SOLUTION: The method for processing a wafer comprises: using a fluorine surface preparation agent 2 to perform a fluorine coating on a top face of a glass substrate 1; sticking a front face W1 of a wafer W to the glass substrate 1 with an ultraviolet curable resin 3 put therebetween; irradiating the wafer W with ultraviolet light from the side of the glass substrate 1 to cure the resin 3 staying in a liquid condition; thereafter grinding the wafer W from its rear face W2; causing the rear face W2 of the wafer W to adhere to a dicing tape 51, thereby to integrate the wafer with a dicing frame 50, and then removing the glass substrate 1 from the front face W1 of the wafer W; removing the cured resin 3 remaining on the front face W1, which had been in the liquid condition, from the wafer; dividing the wafer into devices D by cutting along predetermined cutting lines; and then picking off the devices D from the dicing tape 51. Since the top face of the glass substrate is subjected to the fluorine coating, the glass substrate can be removed from the front face of the wafer readily.

Description

  The present invention relates to a method of grinding a back surface of a wafer to divide it into individual devices and a hard plate used to support the wafer when the method is performed.

  A wafer on which a plurality of devices such as IC, LSI, etc., are defined by dividing lines and formed on the front surface is ground to a predetermined thickness by a grinding machine and then divided into individual devices by a dicing machine etc. And used in various electronic devices.

  Also referred to as pre-dicing, in which a groove with a depth corresponding to the finished thickness of the device is formed on the wafer splitting line, and then the back surface of the wafer is ground to expose the groove from the back surface and divide it into individual devices. Even with this technique, the wafer can be divided into individual devices (see, for example, Patent Document 1).

  In either case, since the surface is held by the chuck table of the grinding apparatus during the back surface grinding of the wafer, a protective tape is attached to the surface to protect the device so that the surface is not damaged.

  However, when the thickness of the wafer is reduced to, for example, 50 μm or less and 30 μm or less by grinding, there is a problem in that the wafer becomes dull and it becomes difficult to carry the wafer.

  In addition, in front dicing, since the surface of the wafer is affixed to a protective tape and ground while being supported by a frame, even if the wafer is divided into individual devices, it can be conveyed by the frame, but it is divided into devices. There is a problem that the devices come into contact with each other at a moment and a part of the device is damaged, and a grinding dust enters the groove and the side surface of the device is contaminated.

  Therefore, the present applicant attaches a wafer or a wafer in which a groove having a depth corresponding to the finished thickness of the device is formed on a planned dividing line to a hard plate via a liquid resin, and irradiates the liquid resin with ultraviolet rays. A technology for grinding the back surface of the wafer after solidifying was developed and a patent application was filed (see Patent Document 2).

JP 11-40520 A JP 2004-296839 A

  However, since the wafer is thinly formed, it is difficult to peel off the hard plate from the surface of the wafer, and there is a problem that workability is poor.

  The present invention has been considered in view of such a problem, and an object of the present invention is to make it possible to easily peel the hard plate from the front surface of the wafer after grinding the back surface of the wafer having the hard plate attached to the front surface. To do.

  A first invention relates to a wafer processing method in which a plurality of devices are partitioned by a predetermined dividing line and a back surface of a wafer formed on the front surface is ground to divide the wafer into individual devices. Fluorine coating process in which fluorine coating is performed with a ring agent, the wafer surface is faced to the fluorine-coated surface of the glass substrate, and the wafer surface is attached to the glass substrate with a liquid resin solidified by ultraviolet irradiation interposed A coalescing process for combining, a liquid resin solidifying process for solidifying the liquid resin by irradiating ultraviolet rays from the glass substrate side, a grinding process for holding the glass substrate side on the chuck table of the grinding apparatus and grinding the back surface of the wafer, and the wafer A dicing tape is attached to a frame having an opening for accommodating and a wafer is attached. C) Adhering the back surface of the wafer to the dicing tape, and a dicing tape adhering step for accommodating the wafer united with the glass substrate in the opening, and the solidification remaining on the wafer surface while peeling the glass substrate from the wafer surface It comprises at least a peeling process for peeling the liquid resin, a dividing process for cutting the division line and dividing it into individual devices, and a pickup process for picking up the individual devices from the dicing tape.

  The second invention relates to a wafer processing method in which a plurality of devices are divided by a predetermined division line and the back surface of the wafer formed on the front surface is ground and divided into individual devices, which corresponds to the finished thickness of the device. A groove forming step for forming a groove having a depth to be divided into lines to be divided, a fluorine coating step for performing fluorine coating on the upper surface of the glass substrate with a silane coupling agent, and a wafer surface facing the fluorine-coated surface of the glass substrate And a coalescing step in which the surface of the wafer is bonded to the glass substrate through a liquid resin that solidifies by irradiation with ultraviolet rays, and a liquid resin solidifying step in which the liquid resin is solidified by irradiating ultraviolet rays from the glass substrate side, Hold the glass substrate side on the chuck table of the grinding machine and grind the backside of the wafer to make the groove into the wafer. Grinding process that exposes from the back side, and dicing tape that attaches the dicing tape to the frame that has the opening that accommodates the wafer, and that attaches the back surface of the wafer to the dicing tape, and accommodates the wafer combined with the glass substrate in the opening. It comprises at least a tape sticking step, a peeling step for peeling the glass substrate from the wafer surface and peeling the solidified liquid resin remaining on the wafer surface, and a pickup step for picking up individual devices from the dicing tape. Is done.

  The third invention is a hard plate constituted by a glass substrate having an upper surface coated with fluorine by a silane coupling agent.

  In the wafer processing method according to the present invention, fluorine coating is performed on the upper surface of the glass substrate with a silane coupling agent, the wafer is attached to the upper surface of the fluorine coating via a resin, and the glass substrate is processed after processing in that state. Since it comprised so that it might peel from a wafer, peeling from the wafer of a glass substrate can be performed smoothly and easily.

  Further, since the hard plate according to the present invention is fluorine-coated on the upper surface, it is easy to peel off the material adhered to the upper surface, which is suitable for carrying out the above wafer processing method.

It is a perspective view which shows an example of a wafer. It is a perspective view which shows the glass substrate by which fluorine coating was carried out. FIG. 3 is a cross-sectional view schematically showing the first embodiment of the present invention by process. It is a perspective view which shows the state which affixes the surface of a wafer on a glass substrate through liquid resin. It is a perspective view which shows the wafer by which the surface was affixed on the glass substrate. It is a perspective view which shows the state which irradiates a liquid resin with an ultraviolet-ray. It is a perspective view which shows the state which grinds the back surface of a wafer. It is a perspective view which shows the state which affixed the back surface of the wafer on the dicing tape, and was supported with the flame | frame. It is a perspective view which shows the state which peels the glass substrate and the solidified liquid resin from the surface of a wafer. It is a perspective view which shows the state which divides | segments a wafer into each device. It is sectional drawing which shows the state which picks up a device schematically. It is sectional drawing which shows schematically the 2nd Embodiment of this invention according to a process. It is a perspective view which shows the state which forms a groove | channel on the surface of a wafer. It is a perspective view which shows the state which affixes the surface of the wafer in which the groove | channel was formed via liquid resin to a glass substrate. It is a perspective view which shows the wafer by which the surface in which the groove | channel was formed was affixed on the glass substrate. It is a perspective view which shows the state which irradiates a liquid resin with an ultraviolet-ray. It is a perspective view which shows the state which grinds the back surface of the wafer in which the groove | channel was formed in the surface. It is a perspective view which shows the wafer which the groove | channel exposed from the back surface. It is a perspective view which shows the state which affixed the back surface of the wafer which the groove | channel exposed on the dicing tape, and was supported with the flame | frame. It is a perspective view which shows the state which peels the glass substrate and the solidified liquid resin from the surface of a wafer.

  The wafer W shown in FIG. 1 is defined by a plurality of devices D formed on a surface W1 by being partitioned by a division line L. Below, the processing method of the wafer W which grinds the back surface W2 of this wafer W and is divided | segmented into each device is demonstrated.

1 1st Embodiment (1) Fluorine coating process First, as shown in FIG. 2, the glass substrate 1 formed in plate shape and substantially the same magnitude | size as the wafer W to be processed is prepared. The glass substrate 1 is formed to have the same diameter as the wafer W or slightly larger than the wafer W.

  As shown in FIGS. 2 and 3A, a fluorine surface treating agent 2 for applying a fluorine coating with a silane coupling agent is applied to the upper surface of the glass substrate 1. As the fluorine surface treatment agent 2, for example, “Novec EGC-1720”, which is a fluorine surface treatment agent manufactured by Sumitomo 3M Limited, can be used. Thus, the hard plate 10 in which the upper surface of the glass substrate 1 is coated with fluorine by the fluorine surface treating agent 2 is formed.

  Application of the fluorine surface treatment agent 2 to the glass substrate 1 is performed by, for example, immersing the glass substrate 1 in the vertical direction while being immersed in the fluorine surface treatment agent 2 and then pulling it upward to adhere to the glass substrate 1. Can be performed by dip coating.

  Fluorine surface treatment agent 2 is an organosilicon compound having both an organic functional group and a hydrolyzable group in one molecule. By utilizing this characteristic structure, a fluorine group is reacted with an organic functional group to add water. The glass surface can be coated with fluorine by forming a chemical bond with the glass surface by hydrolyzing the decomposable group with the glass surface and firmly bonding those having different chemical properties.

(2) Merger Step After the fluorine coating step, as shown in FIG. 4, a liquid resin 3 that is solidified by being irradiated with ultraviolet rays is applied to the fluorine-coated surface of the glass substrate 1. The application of the liquid resin 3 can be performed by, for example, spin coating.

  Then, the surface W1 of the wafer W is opposed to the surface to which the liquid resin 3 is applied, and the surface W1 of the wafer W is bonded to the glass substrate 1 with the liquid resin 3 interposed, as shown in FIGS. Add them together. As the liquid resin 3, for example, a liquid resin disclosed in Japanese Patent Application Laid-Open No. 2004-296839 can be used.

(3) Liquid resin solidification step After the coalescence step, as shown in FIGS. 3C and 6, the liquid resin 3 is irradiated with ultraviolet rays from the glass substrate 1 side to solidify the liquid resin 3, and the glass substrate 1 to stabilize the support state of the wafer W.

(4) Grinding process Next, in the chuck table 40 of the grinding apparatus 4 shown in FIG. 7, for example, the glass substrate 1 side is held and the back surface W2 of the wafer W is exposed. The grinding device 4 includes a grinding means 41 having a configuration in which a grinding wheel 412 is mounted on a mount 411 at the lower end of the rotating shaft 410, and a grindstone 413 is fixed to the lower surface of the grinding wheel 412.

  7 and 3D by rotating the chuck table 40 with the back surface W2 of the wafer W held on the chuck table 40 exposed, and lowering the grinding means 41 while rotating the grinding wheel 412. As shown, the rotating grindstone 413 is brought into contact with the back surface W2 of the wafer W for grinding. When the wafer W has a desired thickness, the grinding means 41 is raised and the grinding is finished.

(5) Dicing tape sticking process After completion of the grinding process, as shown in FIGS. 8 and 3E, the dicing tape 51 is formed so as to close the opening 50 of the frame 5 formed in a ring shape and having the opening 50. Is attached, and the back surface W2 of the wafer W is attached to the dicing tape 51. Then, the wafer W integrated with the glass substrate 1 is accommodated in the opening 50 and is supported by the frame 5 via the dicing tape 51.

(6) Peeling Step Next, the glass substrate 1 is peeled from the surface W1 of the wafer W as shown in FIGS. 3 (F) and 9 with the back surface W2 of the wafer W adhered to the dicing tape 51. . Further, together with the glass substrate 1, the solidified liquid resin 3 remaining on the surface W1 of the wafer W is also peeled off from the surface W1. Since the glass substrate 1 is coated with fluorine, the liquid resin 3 can be peeled off smoothly and easily.

(7) Dividing Step As shown in FIGS. 3G and 10, the cutting blade 6 that rotates at a high speed is cut into the division line L of the wafer W, and the wafer W and the cutting blade 6 are relatively moved in the horizontal direction. By doing so, all the division planned lines are cut and divided into individual devices D.

(8) Pickup Step As shown in FIG. 11, the frame 5 is fixed to the fixing portion 70 of the pickup device 7 and the wafer W is placed on the wafer support portion 71. Then, by moving the frame F and the wafer W relatively in the vertical direction, as shown in FIGS. 3H and 11, the dicing tape 51 is stretched to widen the interval between adjacent devices.

  After widening the space between the devices in this way, the device D is sucked using the collet 72 and picked up from the dicing tape 51.

2 Second Embodiment (1) Groove Forming Step As shown in FIGS. 12A and 13, cutting that rotates at a high speed from the surface W <b> 1 side with respect to all the division lines L of the wafer W shown in FIG. 1. The groove 6 is formed by cutting the blade 6. The groove G has a depth corresponding to the final finished thickness of the device D.

(2) Fluorine coating step As shown in FIG. 2, a glass substrate 1 which is formed in a circular shape and has substantially the same size as the wafer W is prepared. The glass substrate 1 is formed to have the same diameter as the wafer W or slightly larger than the wafer W.

  As shown in FIGS. 2 and 12B, a fluorine surface treating agent 2 is applied to the upper surface of the glass substrate 1. As the fluorine surface treatment agent 2, for example, “Novec EGC-1720”, which is a fluorine surface treatment agent manufactured by Sumitomo 3M Limited, can be used. Thus, the hard plate 10 in which the upper surface of the glass substrate 1 is coated with fluorine by the fluorine surface treating agent 2 is formed. Application | coating of the fluorine surface treating agent 2 with respect to the glass substrate 1 can be performed by the method similar to 1st Embodiment.

(3) Merger Step Next, as shown in FIG. 14, a liquid resin 3 that is solidified by irradiation with ultraviolet rays is applied to the fluorine-coated surface of the glass substrate 1. Then, the surface W1 of the wafer W on which the groove G is formed faces the surface coated with the liquid resin 3, and the surface W1 of the wafer W is interposed by interposing the liquid resin 3 as shown in FIGS. Are attached to the glass substrate 1 and combined.

(4) Liquid resin solidification step After the coalescence step, as shown in FIGS. 12D and 16, the UV curable resin 3 is irradiated with ultraviolet rays from the glass substrate 1 side to solidify the liquid resin, and the glass The supporting state of the wafer W by the substrate 1 is stabilized.

(5) Grinding Step Next, for example, the chuck table 40 of the grinding apparatus 4 shown in FIG. 17 is held on the glass substrate 1 side, the chuck table 40 is rotated with the back surface W2 of the wafer W exposed, and the grinding wheel 412 is rotated. When the grinding means 41 is lowered while rotating, the grinding wheel 413 that rotates is brought into contact with the back surface W2 of the wafer W to perform grinding as shown in FIGS. Then, as shown in FIG. 18, the groove G is exposed from the back surface W <b> 2 and is divided into individual devices D. Since the divided device D is adhered to the glass substrate 1, the shape of the wafer W is maintained as a whole.

(6) Dicing tape sticking step As shown in FIGS. 12 (F) and 19, dicing tape 51 is stuck so as to close the opening 50 of the frame 5 formed in a ring shape and having the opening 50. The back surface W2 of the wafer W divided into the tape 51 is stuck. Then, the wafer W integrated with the glass substrate 1 is accommodated in the opening 50 and is supported by the frame 5 via the dicing tape 51.

(7) Peeling Step Next, the glass substrate 1 is peeled from the surface W1 of the wafer W as shown in FIGS. 12 (G) and 20 with the back surface W2 of the wafer W adhered to the dicing tape 51. . In addition to the glass substrate 1, the solidified liquid resin 3 remaining on the surface W 1 of the wafer W is also peeled off from the surface 1. Since the glass substrate 1 is coated with fluorine, the liquid resin 3 can be smoothly peeled off.

(8) Pickup Step As shown in FIG. 11, the frame 5 is fixed to the fixing portion 70 of the pickup device 7 and the wafer W is placed on the wafer support portion 71. Then, by moving the frame F and the wafer W relatively in the vertical direction, as shown in FIGS. 11 and 12H, the dicing tape 51 is extended to widen the interval between adjacent devices.

  After widening the space between the devices, the device D is sucked using the collet 72 and picked up from the dicing tape 51.

W: Wafer W1: Surface L: Planned line D: Device G: Groove W2: Back surface 10: Hard plate 1: Glass substrate 2: Silane coupling agent 3: Liquid resin 4: Grinding device 40: Chuck table 41: Grinding means 410: Rotating shaft 411: Mount 412: Grinding wheel 413: Grinding wheel 5: Frame 50: Opening 51: Dicing tape 6: Cutting blade 7: Pickup device 70: Fixed part 71: Wafer support part 72: Collet

Claims (3)

A wafer processing method in which a plurality of devices are partitioned by a predetermined dividing line and the back surface of the wafer formed on the front surface is ground to divide into individual devices,
A fluorine coating step of performing fluorine coating on the upper surface of the glass substrate with a silane coupling agent;
A coalescing step in which the surface of the wafer faces the fluorine-coated surface of the glass substrate, and a liquid resin that is solidified by irradiation of ultraviolet rays is interposed to attach the surface of the wafer to the glass substrate to be combined;
A liquid resin solidifying step of solidifying the liquid resin by irradiating ultraviolet rays from the glass substrate side;
A grinding step of holding the glass substrate side on a chuck table of a grinding apparatus and grinding the back surface of the wafer;
A dicing tape adhering step of adhering a dicing tape to a frame having an opening for accommodating the wafer, adhering the back surface of the wafer to the dicing tape, and accommodating the wafer combined with the glass substrate in the opening When,
A peeling step of peeling off the glass substrate from the surface of the wafer and peeling off the solidified liquid resin remaining on the surface of the wafer;
A dividing step of cutting the division line to be divided into individual devices;
A pickup step of picking up the individual devices from the dicing tape;
A method for processing a wafer comprising at least A wafer processing method in which a plurality of devices are partitioned by a predetermined dividing line and the back surface of the wafer formed on the front surface is ground to divide into individual devices,
A groove forming step of forming a groove having a depth corresponding to the finished thickness of the device in a division line;
A fluorine coating step of performing fluorine coating on the upper surface of the glass substrate with a silane coupling agent;
A coalescing step in which the surface of the wafer faces the fluorine-coated surface of the glass substrate, and a liquid resin that is solidified by irradiation of ultraviolet rays is interposed to attach the surface of the wafer to the glass substrate to be combined;
A liquid resin solidifying step of solidifying the liquid resin by irradiating ultraviolet rays from the glass substrate side;
A grinding step of holding the glass substrate side on a chuck table of a grinding apparatus and grinding the back surface of the wafer to expose the groove from the back surface of the wafer;
A dicing tape adhering step of adhering a dicing tape to a frame having an opening for accommodating the wafer, adhering the back surface of the wafer to the dicing tape, and accommodating the wafer combined with the glass substrate in the opening When,
A peeling step of peeling off the glass substrate from the surface of the wafer and peeling off the solidified liquid resin remaining on the surface of the wafer;
A pickup step of picking up individual devices from the dicing tape;
A method for processing a wafer comprising at least   A hard plate composed of a glass substrate having an upper surface coated with fluorine by a silane coupling agent.

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