JP6602702B2 - Protective member forming device - Google Patents

Description

  The present invention relates to a protective member forming apparatus for forming a protective member on the entire surface of one surface of a wafer.

  In a manufacturing process of a wafer or the like, when a circular ingot is formed by slicing a cylindrical ingot with a wire saw, warpage or undulation may be formed on the wafer. In order to remove warpage and waviness, for example, a protective member made of a resin layer is formed on one surface of the wafer, and the other surface of the wafer is ground to remove the warpage and waviness of the wafer.

  In order to form the protective member on one surface of the wafer, for example, a liquid resin is dropped on a sheet placed on the stage, and the wafer held by the holding means is placed on the one side of the wafer. By pressing the liquid from the surface side to the sheet from above and expanding the liquid resin from the center of the wafer toward the outer peripheral side, spreading the liquid resin over the entire area of the one surface, and then irradiating the liquid resin with ultraviolet rays There is a method of curing a liquid resin (see, for example, Patent Document 1 below).

JP 2012-146872 A

  Here, since heat when the resin is cured by irradiating ultraviolet rays is transmitted to the stage, the stage is warmed if the protective members are continuously formed on the plurality of wafers. When the liquid resin is supplied to the warmed stage, the liquid resin is heated and the viscosity decreases. For this reason, the liquid resin easily spreads, and a thin protective member is formed on the wafer, so that it is not possible to appropriately remove the warpage and waviness of the wafer.

  Further, since the holding means for holding the wafer has, for example, a structure in which a porous plate is provided on the ceramic base, the porous plate is likely to store heat by being affected by the temperature of the resin that has risen during curing. Therefore, as the protective member is repeatedly formed, heat is transferred from the porous plate to the wafer held by the holding means, and when the liquid resin is pushed by the wafer, the heat is transferred to the liquid resin to facilitate the expansion of the liquid resin. There is a problem that it ends up.

  The present invention has been made in view of the above circumstances, and an object thereof is to form a protective member having a predetermined thickness even when the temperature of a holding means for holding a wafer rises.

  The present invention is a protective member forming apparatus for forming a protective member by spreading and curing a liquid resin on the entire surface of one surface of a wafer, the stage having a film holding surface for holding a film, and the stage holding the stage Resin supply means for supplying a predetermined amount of liquid resin onto the film, holding means having a wafer holding surface for sucking and holding the other surface of the wafer facing the film holding surface of the stage, and the holding means Is extended to the entire surface of one surface of the wafer by the expanding means, and the expanding means for expanding the liquid resin supplied onto the film by the wafer held by the holding means. A curing means for curing the liquid resin; and a control means capable of controlling the expansion means. The expansion means includes a pressing force recognition unit that recognizes a pressing force for expanding the liquid resin. The holding unit includes a temperature measuring unit that measures the temperature of the wafer holding surface of the holding unit, and the control unit shows a correlation between the temperature measured by the temperature measuring unit and a predetermined pressing force. Correlation data is provided, the predetermined pressing force is set according to the temperature measured by the temperature measurement unit with reference to the correlation data, and the predetermined pressing force is set by controlling the expansion means. The liquid resin is expanded to form a protective member having a predetermined thickness.

  The protective member forming apparatus according to the present invention includes a stage for holding a film, a resin supply means for supplying a liquid resin onto the film held by the stage, and a holding means having a wafer holding surface for sucking and holding the other surface of the wafer. And expanding means for lowering the holding means toward the stage and spreading the liquid resin supplied on the film by the wafer held by the holding means, and the liquid resin being spread on the entire surface of one side of the wafer by the expanding means Curing means for curing the resin, and control means for controlling the expansion means. The expansion means includes a pressing force recognition unit that recognizes a pressing force for expanding the liquid resin, and the holding means holds the wafer of the holding means. A temperature measuring unit that measures the temperature of the surface, and the control unit includes correlation data indicating a correlation between the temperature measured by the temperature measuring unit and a predetermined pressing force, and the control unit Since the expansion means can be controlled by setting the predetermined pressing force according to the temperature measured by the temperature measurement section with reference to the relational data, even if the temperature of the wafer holding surface of the holding means rises, the temperature measurement section A protective member having a predetermined thickness can be formed by pressing the liquid resin over the entire surface of one surface of the wafer with a predetermined pressing force according to the temperature measured by the above.

It is a perspective view which shows the structure of a protection member formation apparatus. It is sectional drawing which looked at the structure of the protection member formation apparatus from the side surface side. It is a graph which shows the correlation data with which a control means is equipped.

  A protection member forming apparatus 1 shown in FIG. 1 is an example of an apparatus that forms a protection member by spreading and curing a liquid resin on one surface of a wafer W. The protection member forming apparatus 1 is disposed in the casing 100 and the casing 100. The apparatus base 101, the column 102 erected on the apparatus base 101, the support base 103 disposed adjacent to the apparatus base 101, and the rear end side of the housing 100 are connected to the upper end of the two stages in the vertical direction. A cassette housing body 104 having housing spaces 2a and 2b. The upper storage space 2a is provided with a cassette 3a in which a plurality of wafers W before the protection member is formed is disposed, and the lower storage space 2b is accommodated with a plurality of wafers W in which a protection member is formed. A cassette 3b is provided.

  A first support base 6a and a second support base 6b located below the first support base 6a are connected to the column 102 at the rear in the Y-axis direction. The first support base 6a is provided with a wafer detection unit 7 for detecting the center position and orientation of the wafer W before the protective member is formed. A film cutter 8 that cuts the protective member formed on the wafer W along the outer shape of the wafer W is disposed on the second support base 6b.

  Between the cassette housing main body 104 and the wafer detector 7 and the film cutter 8, there is disposed a first wafer transport means 4 for carrying out and carrying in the wafer W to and from the cassettes 3a and 3b. The first wafer transport means 4 unloads the wafer W before the protection member is formed from the cassette 3a and loads it into the first support base 6a, and unloads the wafer W on which the protection member has been formed from the second support base 6b. Then, it can be carried into the cassette 3b.

  The apparatus base 101 includes a film supply means 10 having a roll portion 11 in which a film 12 having a resin dripped on its upper surface is wound in a roll shape, and a stage 20 having a circular film holding surface 21 for holding the film 12. Prepare. A ring-shaped convex portion 22 is formed on the outer periphery of the film holding surface 21. The liquid resin is accumulated in a region inside the convex portion 22 to prevent the liquid resin from being scattered outside the convex portion 22. The film holding surface 21 is made of, for example, quartz glass. Although not shown, the film holding surface 21 has a plurality of suction holes connected to a suction source, and is configured to suck and hold the film 12 placed on the film holding surface 21 from below.

  A film placing means 30 is disposed on the support base 103. The film mounting means 30 includes an arm portion 31 extending in a direction intersecting the Y-axis direction (X-axis direction), and a clamp portion 32 attached to a side surface of the arm portion 31. The clamp unit 32 can clamp the film 12 wound around the roll unit 11 and pull it in the Y-axis direction and place it on the stage 20.

  In the vicinity of the stage 20, a resin supply means 40 that drops a predetermined amount of liquid resin on the film 12 held by the stage 20 is provided. The resin supply means 40 includes a resin supply nozzle 41, a dispenser 42 that sends a liquid resin to the resin supply nozzle 41, and a connection pipe 43 that connects the resin supply nozzle 41 and the dispenser 42. The resin supply nozzle 41 has a supply port 41 a for supplying a liquid resin toward the film holding surface 21 of the stage 20. The dispenser 42 is connected to a resin supply source (not shown). The resin supply nozzle 41 is pivotable, and the supply port 41 a can be positioned on the upper side of the stage 20.

  In front of the column 102 in the Y-axis direction, a holding unit 50 that sucks and holds the other surface of the wafer W so as to face the film holding surface 21 of the stage 20 and a holding unit 50 that lowers the holding unit 50 toward the stage 20. The expansion means 60 which spreads the liquid resin dripped on the film 12 by the wafer W held by the The apparatus base 101 includes a curing unit 70 that cures the liquid resin that is expanded on one surface of the wafer W by the expansion unit 60. The curing means 70 has, for example, a UV lamp that irradiates ultraviolet rays.

  As shown in FIG. 2, the holding means 50 includes a disk-shaped wheel 51, a holding portion 52 having a wafer holding surface 52a for sucking and holding the wafer W, and the temperature of the wafer holding surface 52a disposed in the wheel 51. And a temperature measuring unit 53 for measuring. The holding part 52 is formed of, for example, a porous member. A suction source (not shown) is connected to the holding portion 52, and the wafer W can be sucked and held by the wafer holding surface 52a.

  The temperature measurement unit 53 is configured by, for example, a contact-type temperature sensor, and is disposed in contact with the holding unit 52. The temperature measuring unit 53 can measure the surface temperature of the wafer holding surface 52a when the liquid resin is pushed and spread by the wafer W sucked and held by the holding unit 52.

  As shown in FIG. 1, the expansion means 60 includes a ball screw 61 extending in the Z-axis direction, a motor 62 connected to one end of the ball screw 61, a pair of guide rails 63 extending in parallel with the ball screw 61, A lifting plate 64 having a holding means 50 connected to one surface and a pressing force recognition unit 65 for recognizing a pressing force for expanding and spreading the liquid resin are provided. The other surface of the elevating plate 64 is in sliding contact with the pair of guide rails 63, and a ball screw 61 is screwed into a nut formed on the other surface side of the elevating plate 64. When the ball screw 61 is rotated by being driven by the motor 62, the expansion means 60 moves the elevating plate 64 along the pair of guide rails 63 in the Z-axis direction, so that the expansion means 60 is perpendicular to the film holding surface 21 of the stage 20. The holding means 50 can be raised and lowered in the direction.

  The pressing force recognition unit 65 includes a piezoelectric element used for piezoelectric load measurement. For example, the pressing force recognizing unit 65 may be provided with an air gap slightly spaced from the holding unit 52 at three locations inside the wheel 51 of the holding unit 50, and the piezoelectric elements may be arranged respectively. In the pressing force recognition unit 65, the three piezoelectric elements each receive a pressure change of the air gap when the expansion means 60 expands the liquid resin in the vertical direction (Z-axis direction), and generates voltages. The total value can be obtained as a pressing force for expanding the liquid resin.

  The protection member forming apparatus 1 includes a control unit 80 that controls the expansion unit 60. The control unit 80 is connected to the motor 62, the temperature measurement unit 53, and the pressing force recognition unit 65. The control means 80 includes a memory element such as a memory, and correlation data 81 indicating the correlation between the temperature measured by the temperature measuring unit 53 and a predetermined pressing force is stored in the memory element. Correlation data 81 is obtained by operating the protection member forming apparatus 1 in advance using a plurality of wafers W for experiments to form a protection member, and measuring the thickness of the protection member 50, whereby the wafer holding surface of the holding means 50 is measured. Data obtained for a suitable predetermined pressing force according to the temperature of 52a. The contents of the correlation data 81 are shown, for example, in the graph of FIG. The horizontal axis of the graph represents the temperature (° C.) of the wafer holding surface 52a, and the vertical axis of the graph represents the pressing force (N) for expanding the liquid resin by the expanding means 60. Referring to the correlation data 81, it can be confirmed that the pressing force should be set smaller as the temperature of the wafer holding surface 52a increases. For example, when the temperature of the wafer holding surface 52a is 26 ° C., it can be confirmed that 3300N is a suitable pressing force. The control unit 80 can control the expansion unit 60 by referring to the correlation data 81 and setting a pressing force corresponding to the temperature measured by the temperature measurement unit 53 in the expansion unit 60.

  Next, an operation example of the protective member forming apparatus 1 will be described. The wafer W shown in the present embodiment is an example of a circular plate-like workpiece, and is, for example, a silicon wafer. First, one wafer W before the protective member is formed is taken out from the cassette 3a by the first wafer transport means 4 and transported to the first support base 6a. When the wafer detection unit 7 detects the center position and orientation of the wafer W, the second wafer transport means 5 carries the wafer W out of the first support base 6a and transfers it to the holding means 50. As shown in FIG. 2, the holding unit 50 sucks and holds the other surface of the wafer W with the wafer holding surface 52 a of the holding unit 52.

  In parallel with the conveyance of the wafer W to the holding means 50, the clamp part 32 of the film mounting means 30 shown in FIG. 1 clamps the film 12, moves in the Y-axis direction, and pulls out the film 12 from the roll part 11. Place on the film holding surface 21 of the stage 20. The film 12 is sucked and held by the film holding surface 21 under the action of a suction source (not shown).

  As shown in FIG. 2, the resin supply means 40 rotates the resin supply nozzle 41 to position the supply port 41 a on the upper side of the stage 20. Subsequently, a liquid resin 44 whose temperature is controlled at a predetermined temperature (for example, 19 ° C.) is sent to the resin supply nozzle 41 by the dispenser 42 shown in FIG. 1 and sucked and held on the stage 20 from the supply port 41a. A liquid resin 44 is dropped toward the film 12. As the liquid resin 44, for example, an ultraviolet curable resin is used. When a predetermined amount of the liquid resin 44 is deposited on the film 12, the resin supply means 40 stops supplying the liquid resin 44 to the film 12.

  Next, in a state where the other surface of the wafer W is sucked and held by the wafer holding surface 52 a of the holding means 50, the expansion means 60 rotates the ball screw 61 by driving the motor 62 and lowers the holding means 50. When one surface of the wafer W sucked and held by the holding means 50 comes into contact with the liquid resin 44 and the holding means 50 is further lowered, the liquid resin 44 pressed downward by the one surface of the wafer W is transferred to the wafer W. Expanded radially. At this time, the pressing force recognizing unit 65 measures the pressing force for expanding the liquid resin 44, and the temperature measuring unit 53 measures the surface temperature of the wafer holding surface 52a.

  As a result of the temperature measurement by the temperature measurement unit 53, for example, when the temperature of the wafer holding surface 52a is 22 ° C., the control unit 80 refers to the correlation data 81 shown in FIG. Recognizing that the pressing force is 3400 N, the pressing force for expanding the liquid resin 44 against the expanding means 60 is set to 3400 N. That is, while measuring the pressing force with the pressing force recognition unit 65, the motor 62 of the expansion means 60 is controlled so that the measured value becomes 3400N, the moving speed in the vertical direction of the holding means 50 is adjusted, The pressing force against the resin 44 is adjusted. In this way, a predetermined pressing force (3400 N) is applied to the liquid resin 44 on one surface of the wafer W while controlling the expansion means 60 according to the temperature of the wafer holding surface 52a, that is, according to the viscosity of the liquid resin 44. The liquid resin 44 can be expanded with a predetermined thickness over the entire surface of one surface of the wafer W. Thereafter, the curing means 70 irradiates ultraviolet light toward the liquid resin 44 expanded to a predetermined thickness. As a result, the liquid resin 44 is cured and formed on one surface of the wafer W as a protective member having a predetermined thickness.

  In this way, the wafer W on which the protective member is formed is transported to the second support 6b by the second wafer transport means 5, and the excess film 12 is cut along the outer shape of the wafer W by the film cutter 8. The first wafer transport means 4 accommodates the cassette 3b.

  Here, when the curing means 70 irradiates the liquid resin 44 with ultraviolet light, the stage 20 is warmed. Although the stage 20 is likely to return to room temperature relatively early, if the formation of the protective member for the plurality of wafers W is continued, the temperature of the stage 20 also gradually increases. When the liquid resin 44 is supplied onto the film 12 held on the stage 20 in this state, the temperature of the liquid resin 44 also rises and becomes easy to expand, and the liquid resin 44 whose temperature has increased in the wafer W held by the holding means 50. The heat is transmitted to the wafer holding surface 52a through the wafer W. In particular, when the wafer W is made of silicon, the heat conductivity is high, so that heat is easily transmitted to the wafer holding surface 52a. In this manner, as the formation of the protective members for the plurality of wafers W is repeated, heat is stored in the holding portion 52, and the temperature of the wafer holding surface 52a rises. When the liquid resin 44 is pressed, the heat is transmitted to the liquid resin 44 through the wafer W, so that the liquid resin 44 is easily spread.

  Therefore, while the protective member forming apparatus 1 is in operation (while the protective members are continuously formed on the plurality of wafers W), the pressing force recognizing unit 65 always measures the pressing force for expanding the liquid resin 44 and the temperature measuring unit 53. Then, the surface temperature of the wafer holding surface 52a is measured. As a result of the temperature measurement by the temperature measurement unit 53, the control means 80 refers to the correlation data 81, and, for example, when the temperature of the wafer holding surface 52a is increased to 26 ° C. as shown in FIG. The pressing force for expanding the liquid resin 44 against the means 60 is set to 3300N. That is, while measuring the pressing force with the pressing force recognition unit 65, the motor 62 of the expansion means 60 is controlled so that the measured value becomes 3300N, the vertical speed of the holding means 50 is adjusted, and the liquid resin 44 is adjusted. As described above, even when the temperature of the wafer holding surface 52a is increased due to the temperature increase of the stage 20, the liquid resin 44 is controlled on one surface of the wafer W while controlling the expansion means 60 according to the temperature of the wafer holding surface 52a. Is expanded with a predetermined pressing force (3300 N), the liquid resin 44 can be expanded with a predetermined thickness over the entire surface of one surface of the wafer W.

  As described above, the protective member forming apparatus 1 according to the present invention includes the stage 20 that holds the film 12, the resin supply means 40 that supplies the liquid resin 44 onto the film 12 that the stage 20 holds, and the other of the wafers W. A holding means 50 having a wafer holding surface 52a for sucking and holding the surface, and an extension for lowering the holding means 50 toward the stage 20 and expanding the liquid resin 44 supplied on the film 12 by the wafer W held by the holding means 50 Means 60, a hardening means 70 for hardening the liquid resin 44 spread on the entire surface of one surface of the wafer W by the extension means 60, and a control means 80 capable of controlling the extension means 60. Includes a pressing force recognition unit 65 for recognizing a pressing force for expanding the liquid resin 44, and the holding unit 50 sets the temperature of the wafer holding surface 52a of the holding unit 50. The control unit 80 includes correlation data 81 indicating the correlation between the temperature measured by the temperature measurement unit 53 and a predetermined pressing force, and the control unit 80 stores the correlation data 81. With reference to this, since the expansion means 60 can be controlled by setting to a predetermined pressing force according to the temperature measured by the temperature measuring unit 53, for example, the protective member for a plurality of wafers W can be maintained by continuously forming it. Even if the temperature of the wafer holding surface 52a of the means 50 rises, the liquid resin 44 is pushed over the entire surface of one surface of the wafer W with a predetermined pressing force corresponding to the temperature measured by the temperature measuring unit 53, and a predetermined amount is applied. A protective member having a thickness can be formed.

1: protective member forming apparatus 100: casing 101: apparatus base 102: column 103: support base 104: cassette housing body 2a, 2b: housing space 3a, 3b: cassette 4: first wafer transport means 5: second wafer transport Means 6a: 1st support stand 6b: 2nd support stand 7: Wafer detection part 8: Film cutter 10: Film supply means 11: Roll part 12: Film 20: Stage 21: Film holding surface 22: Convex part 30: Film mounting Placement means 31: Arm part 32: Clamp part 40: Resin supply means 41: Resin supply nozzle 41a: Supply port 42: Dispenser 43: Connection pipe 44: Liquid resin 50: Holding means 51: Wheel 52: Holding part 52a: Wafer holding Surface 53: Temperature measuring unit 60: Expansion means 61: Ball screw 62: Motor 63: Guide rail 64 Lift plate 65: pressing force recognizing unit 70: curing means 80: control means 81: Correlation Data

Claims (1)

A protective member forming apparatus that forms a protective member by spreading and curing a liquid resin on the entire surface of one surface of a wafer,
A stage having a film holding surface for holding the film;
Resin supply means for supplying a predetermined amount of liquid resin onto the film held by the stage;
Holding means having a wafer holding surface for sucking and holding the other surface of the wafer facing the film holding surface of the stage;
Expansion means for lowering the holding means toward the stage and expanding the liquid resin supplied onto the film with a wafer held by the holding means;
A curing means for curing the liquid resin that has been spread over the entire surface of one surface of the wafer by the expansion means;
Control means capable of controlling the expansion means,
The expansion means includes a pressing force recognition unit that recognizes a pressing force for expanding the liquid resin,
The holding means includes a temperature measuring unit that measures the temperature of the wafer holding surface of the holding means,
The control means includes correlation data indicating a correlation between the temperature measured by the temperature measurement unit and a predetermined pressing force, and refers to the correlation data and corresponds to the temperature measured by the temperature measurement unit. A protective member forming apparatus configured to form a protective member having a predetermined thickness by setting a predetermined pressing force and expanding the liquid resin with the predetermined pressing force set by controlling the expansion means.

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