JP6153337B2 - UV irradiation equipment - Google Patents

Description

  The present invention relates to an ultraviolet irradiation device for irradiating ultraviolet rays onto a protective tape having an adhesive layer that is cured by irradiating ultraviolet rays attached to the back surface of a wafer.

  In recent years, it has been demanded that the thickness of a wafer be made thinner, for example, 50 μm or less, in order to achieve a reduction in weight and size of electrical equipment.

  Such a thinly formed wafer is warped and becomes difficult to handle and may be damaged during transportation. Therefore, by grinding only the back surface corresponding to the device region where the wafer device is formed, grinding is formed as a reinforcing portion by forming an annular convex portion on the back surface of the wafer corresponding to the outer peripheral surplus region surrounding the device region. A method has been proposed (see Patent Document 1).

  And after removing the annular convex part as a method of cutting along the street and dividing the wafer in which the concave part is formed in the center of the back surface and the annular convex part surrounding the concave part is formed along the street in this way A method of cutting with a cutting blade from the surface side of a wafer has been proposed (see Patent Document 2). In the above dividing method, a protective tape whose adhesive strength is reduced by first irradiating the back side of the wafer with ultraviolet rays is pasted, and a dividing groove is formed at the boundary between the circular concave portion and the annular convex portion. Next, ultraviolet rays are irradiated using a mask having a circular opening corresponding to the annular convex portion, and after reducing the adhesive force in the region corresponding to the annular convex portion of the protective tape, only the annular convex portion is peeled off. After that, cutting is performed along the street from the front side of the wafer.

JP 2007-173487 A JP 2011-061137 A

  In the above-described ultraviolet irradiation device, since the ultraviolet lamps are arranged on one side and a mask having an opening corresponding to the annular convex portion is used to irradiate the protective tape adhered to the annular convex portion, the masked protective tape is used. There is a problem that the area of the ultraviolet lamp that does not contribute to curing is large and is not efficient and economical.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an ultraviolet irradiation device capable of efficiently and economically irradiating ultraviolet rays onto a protective tape attached to an annular convex portion. It is.

In order to solve the above-described problems and achieve the object, an ultraviolet irradiation device of the present invention has a circular recess formed on the back surface and an annular projection surrounding the circular recess, and the circular recess and the annular projection. A wafer in which a dividing groove is formed at the boundary with the part, a protective tape having an adhesive layer that is cured by irradiating ultraviolet rays attached to the back surface of the wafer, and a ring attached to the outer peripheral portion of the protective tape an ultraviolet irradiation apparatus for irradiating ultraviolet rays to adhere to the protective tape on the lower surface of the annular protrusion in order to peel the annular protrusions from the wafer unit comprised of a frame, corresponding to the annular projection An ultraviolet irradiation means arranged in a ring shape, a casing formed in a box shape with an opening on the upper side, and the ultraviolet irradiation means arranged on the inside, and the wafer on the upper surface covering the opening of the casing Tape side down A light shielding plate for supporting, consists, light shielding plate, and characterized in that together with and a ring-shaped convex portions equivalent to the size of the ring-shaped ultraviolet ray transmitting portion of the wafer, is formed in a flat plate shape To do.

  In the ultraviolet irradiation device, the ultraviolet irradiation means is preferably formed by arranging a plurality of ultraviolet light emitting diodes in a ring shape equivalent to the size of the annular convex portion.

  Further, in the ultraviolet irradiation device, the ultraviolet irradiation means is formed by arranging a plurality of types of ultraviolet light emitting diodes that irradiate ultraviolet rays having different wavelengths in the ultraviolet light region, each arranged in a ring shape corresponding to the annular convex portion. It is preferable that an ultraviolet light emitting diode having a wavelength suitable for the type of the adhesive layer of the protective tape is turned on.

  Therefore, in the ultraviolet irradiation device of the present invention, the ultraviolet irradiation means is arranged in a ring shape corresponding to the annular convex portion, and the ring-shaped ultraviolet transmission portion is provided in the light shielding plate corresponding to the annular convex portion. Therefore, it is efficient without irradiating ultraviolet rays to extra portions other than the portion attached to the annular convex portion of the adhesive layer of the protective tape.

  The wavelength of the ultraviolet rays that are effectively cured differs depending on the type of the adhesive layer of the protective tape, and ultraviolet rays having a wavelength suitable for the type of the protective tape can be irradiated, so that the ultraviolet irradiation time can be shortened and productivity can be improved.

  Theoretically, the shorter wavelength side has higher energy, so it seems to be cured faster, but if the adhesive layer has a thickness, it will be absorbed and UV rays will not reach the inside, and only the surface of the adhesive layer will be cured and as a whole Although it may not work, the surface and the inside can be cured in a short time by irradiating multiple wavelengths.

FIG. 1 is a perspective view illustrating an outline of a configuration example of an annular convex portion removing apparatus including an ultraviolet irradiation device according to an embodiment. FIG. 2 is an exploded perspective view illustrating an outline of a configuration example of the ultraviolet irradiation device according to the embodiment. FIG. 3 is a plan view illustrating an outline of a configuration example of the ultraviolet irradiation device according to the embodiment. FIG. 4 is a cross-sectional view illustrating an outline of a configuration example of the ultraviolet irradiation apparatus according to the embodiment. FIG. 5 is a plan view illustrating an outline of a configuration example of an ultraviolet irradiation apparatus according to Modification 1 of the embodiment. FIG. 6 is a plan view illustrating an outline of a configuration example of an ultraviolet irradiation apparatus according to Modification 2 of the embodiment. FIG. 7 is a plan view illustrating an outline of a configuration example of an ultraviolet irradiation apparatus according to another modification of the embodiment.

  DESCRIPTION OF EMBODIMENTS Embodiments (embodiments) for carrying out the present invention will be described in detail with reference to the drawings. The present invention is not limited by the contents described in the following embodiments. The constituent elements described below include those that can be easily assumed by those skilled in the art and those that are substantially the same. Furthermore, the structures described below can be combined as appropriate. Various omissions, substitutions, or changes in the configuration can be made without departing from the scope of the present invention.

Embodiment
An ultraviolet irradiation device according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view illustrating an outline of a configuration example of an annular convex portion removing apparatus including an ultraviolet irradiation device according to an embodiment. FIG. 2 is an exploded perspective view illustrating an outline of a configuration example of the ultraviolet irradiation device according to the embodiment. FIG. 3 is a plan view illustrating an outline of a configuration example of the ultraviolet irradiation device according to the embodiment. FIG. 4 is a cross-sectional view illustrating an outline of a configuration example of the ultraviolet irradiation apparatus according to the embodiment.

  The ultraviolet irradiation device 2 according to the present embodiment applies ultraviolet rays U to the protective tape T attached to the lower surface of the annular convex portion C in order to peel the annular convex portion C of the wafer W from the wafer unit Wa shown in FIG. Irradiation. As shown in FIG. 4, the wafer unit Wa to which the ultraviolet ray U is irradiated by the ultraviolet ray irradiation device 2 includes a wafer W, a protective tape T, and an annular frame F.

  As shown in FIG. 4, the wafer W is formed on a device region DR in which devices (not shown) are formed in a region partitioned in a lattice shape by streets (not shown) formed on the upper surface, and on the back surface (lower surface) of the device region DR. And a circular convex portion C surrounding the circular concave portion R. The thickness of the device region DR is 50 μm or less due to the circular recess R, and the thickness of the annular convex portion C is larger than the thickness of the device region DR, for example, 700 μm. The upper surface of the device region DR and the upper surface of the annular convex portion C are formed flush with each other, and a step is formed between the circular concave portion R and the annular convex portion C.

  The protective tape T is made of a material that transmits ultraviolet rays U. Further, the protective tape T has an adhesive layer A adhered to the back surface (lower surface) of the wafer W. The adhesive layer A is cured by irradiating ultraviolet rays U. The adhesive layer A is attached to the lower surface of the wafer W across the circular concave portion R and the annular convex portion C. The annular frame F is attached to the outer peripheral portion of the protective tape T.

  In the wafer W, a dividing groove S is formed at a boundary portion between the circular concave portion R and the annular convex portion C by a cutting blade or a laser beam (not shown). The dividing groove S divides the boundary portion between the circular concave portion R and the annular convex portion C over the entire circumference of the wafer W, and divides the protective tape T to the center in the thickness direction. In the wafer unit Wa, only the annular convex portion C is peeled and removed by the annular convex portion removing device 1 shown in FIG.

  An annular projection removing device 1 shown in FIG. 1 includes an ultraviolet irradiation device 2 that can be moved up and down in the Z-axis direction by an elevator mechanism (not shown), and a cassette (not shown) placed on a case 3 that accommodates the ultraviolet irradiation device 2. A loading / unloading means 4 for loading / unloading the wafer unit Wa into / from the cassette, a chuck table 5 on which the wafer unit Wa is placed by the loading / unloading means 4, and an annular convex portion C from the wafer unit Wa placed on the chuck table 5. And a claw assembly 6 for peeling off.

  The cassette accommodates a plurality of wafer units Wa before and after peeling the annular convex portion C. The carry-in / out means 4 takes out the wafer unit Wa before peeling the annular convex portion C and before irradiating the ultraviolet ray U from the cassette and inserts it into the case 3, and inserts the wafer unit Wa before peeling the annular convex portion C and after irradiating the ultraviolet ray U. Is taken out from the case 3 and placed on the chuck table 5, and the wafer unit Wa after the peeling of the annular convex portion C is inserted into the cassette. The chuck table 5 sucks and holds the circular concave portion R of the wafer W of the wafer unit Wa placed on the surface via the protective tape T. A plurality of frame fixing portions 7 that fix the annular frame F and the like are provided around the chuck table 5. The claw assembly 6 is provided so as to be movable in the Z-axis direction by the Z-axis moving means 8, and is provided so as to be movable in the Y-axis direction by the Y-axis moving means 9. The claw assembly 6 is lowered by the Z-axis moving means 8 to sandwich the annular convex portion C, and lifts to remove and remove only the annular convex portion C from the wafer unit Wa.

  The ultraviolet irradiation device 2 is accommodated in a case 3 installed in the annular convex portion removing device 1 and is provided on the lower surface of the annular convex portion C of the protective tape T of the wafer unit Wa before the annular convex portion C is peeled off. The adhered adhesive layer A is irradiated with ultraviolet rays U. The case 3 that accommodates the ultraviolet irradiation device 2 is inserted with the wafer unit Wa before the peeling of the annular protrusion C and before the irradiation of the ultraviolet U by the loading / unloading means 4 and the ultraviolet light before the peeling of the annular protrusion C. The wafer unit Wa after the U irradiation is taken out.

  As shown in FIG. 2, the ultraviolet irradiation device 2 includes a housing 21 that is open at the top, ultraviolet irradiation means 22 disposed in the housing 21, and a light shielding plate 23 that covers the opening of the housing 21. Has been. The housing | casing 21 is formed in the flat box shape which upper direction opened. The ultraviolet irradiation means 22 is arranged in a ring shape corresponding to the annular convex portion C. As shown in FIG. 3, the ultraviolet irradiation means 22 is formed by arranging a plurality of ultraviolet light emitting diodes 24 in a ring shape equivalent to the size of the annular convex portion C. The ultraviolet light emitting diode 24 irradiates the ultraviolet light U that cures the adhesive layer A of the protective tape T.

  The light shielding plate 23 is formed in a flat plate shape. The light shielding plate 23 supports the wafer W of the wafer unit Wa on the upper surface with the protective tape T on the lower side. The light shielding plate 23 supports the wafer unit Wa accommodated in the case 3. The light shielding plate 23 includes a ring-shaped ultraviolet ray transmitting portion 25 having a size equivalent to the annular convex portion C of the wafer W of the wafer unit Wa. The ultraviolet ray transmitting part 25 transmits the ultraviolet ray U irradiated by the plurality of ultraviolet light emitting diodes 24 of the ultraviolet ray irradiation means 22. Further, the light shielding plate 23 does not transmit the ultraviolet rays U irradiated by the plurality of ultraviolet light emitting diodes 24 of the ultraviolet irradiation means 22 in portions other than the ultraviolet light transmitting portion 25. The ultraviolet ray transmitting portion 25 is made of a material that is provided on the light shielding plate 23 and transmits the ultraviolet ray U. In the present invention, the ultraviolet transmissive part 25 may be a hole penetrating the light shielding plate 23.

  The ultraviolet irradiation device 2 supports the wafer W of the wafer unit Wa before peeling off the annular projection C accommodated in the case 3 with the light shielding plate 23 facing the protective tape T downward. Then, since the ultraviolet-ray transmission part 25 is formed in the magnitude | size equivalent to the cyclic | annular convex part C, as shown in FIG. Then, the ultraviolet irradiation device 2 irradiates ultraviolet rays U from the plurality of ultraviolet light emitting diodes 24 of the ultraviolet irradiation means 22. Then, the ultraviolet rays U irradiated from the plurality of ultraviolet light emitting diodes 24 of the ultraviolet irradiation means 22 were stuck to the lower surface of the annular convex portion C in the adhesive layer A of the protective tape T through the ultraviolet transmitting portion 25. The part is irradiated. And the part stuck mainly on the lower surface of the cyclic | annular convex part C of the adhesion layer A of the protective tape T irradiated with the ultraviolet-ray U hardens | cures, and adhesive force becomes weak. Next, the ultraviolet irradiation device 2 irradiates the ultraviolet rays U from the plurality of ultraviolet light emitting diodes 24 of the ultraviolet irradiation means 22 for a predetermined time, and then stops the irradiation of the ultraviolet rays U.

  The wafer unit Wa before peeling off the annular convex portion C is taken out from the case 3 by the loading / unloading means 4 and sucked and held by the chuck table 5, and the annular convex portion C is sandwiched between the claw assemblies 6. In the wafer unit Wa, when the claw assembly 6 is lifted by the Z-axis moving means 8, the portion of the adhesive layer A of the protective tape T, which is mainly adhered to the lower surface of the annular convex portion C, is cured and adhered. Since the force is weakened, only the annular convex portion C is peeled off from the protective tape T. After the claw assembly 6 is moved in the Y-axis direction by the Y-axis moving means 9, the annular convex portion C peeled off from the protective tape T is discarded in the annular convex portion accommodating case 10. Then, the wafer unit Wa from which the annular convex portion C has been peeled is inserted into the cassette by the carry-in / out means 4, and then cut along the street by a cutting blade or laser beam (not shown) to be divided into devices.

  As described above, according to the ultraviolet irradiation device 2 according to the present embodiment, the ultraviolet irradiation means 22 is disposed in a ring shape corresponding to the annular convex portion C, and the ring shape corresponding to the annular convex portion C is further provided. An ultraviolet transmissive part 25 is provided on the light shielding plate 23. For this purpose, the ultraviolet rays U irradiated by the ultraviolet irradiation means 22 are mainly irradiated on the portion of the adhesive layer A of the protective tape T, which is mainly adhered to the lower surface of the annular convex portion C, and on the other portions. Irradiation is suppressed. Therefore, it can suppress irradiating the ultraviolet-ray U to the excess location other than the part affixed on the lower surface of the cyclic | annular convex part C of the adhesion layer A of the protective tape T, and irradiates the ultraviolet-ray U efficiently and economically. can do.

  Further, since the plurality of ultraviolet light emitting diodes 24 of the ultraviolet irradiation means 22 are arranged in a ring shape equivalent to the size of the annular convex portion C, the lower surface of the annular convex portion C of the adhesive layer A of the protective tape T is provided. Irradiation of ultraviolet rays U to an extra portion other than the attached portion can be reliably suppressed.

[Modification 1]
An ultraviolet irradiation apparatus according to Modification 1 of the embodiment of the present invention will be described with reference to the drawings. FIG. 5 is a plan view illustrating an outline of a configuration example of an ultraviolet irradiation apparatus according to Modification 1 of the embodiment. In FIG. 5, the same parts as those of the above-described embodiment are denoted by the same reference numerals and description thereof is omitted.

  In the ultraviolet irradiation device 2 according to the modified example 1, the ultraviolet irradiation means 22 includes a plurality of fluorescent lamps 24a for irradiating ultraviolet rays U for curing the adhesive layer A of the protective tape T, as shown in FIG. It is arranged in a ring shape corresponding to C. As shown in FIG. 5, the ultraviolet irradiation means 22 includes a plurality of fluorescent lamps 24a arranged in a ring shape equivalent to the size of the annular convex portion C at equal intervals, and each fluorescent lamp 24a is tangent to the annular convex portion C. Are arranged in parallel. Further, the fluorescent lamps 24a adjacent to each other overlap each other.

  The ultraviolet irradiation device 2 according to the modified example 1 has an extra portion other than the portion attached to the lower surface of the annular convex portion C of the adhesive layer A of the protective tape T, similarly to the ultraviolet irradiation device 2 of the above-described embodiment. Irradiation with ultraviolet rays U can be suppressed, and the ultraviolet rays U can be efficiently and economically irradiated.

[Modification 2]
An ultraviolet irradiation apparatus according to Modification 2 of the embodiment of the present invention will be described with reference to the drawings. FIG. 6 is a plan view illustrating an outline of a configuration example of an ultraviolet irradiation apparatus according to Modification 2 of the embodiment. In FIG. 6, the same parts as those in the above-described embodiment are denoted by the same reference numerals and description thereof is omitted.

  In the ultraviolet irradiation device 2 according to the modified example 2, as shown in FIG. 6, the ultraviolet irradiation means 22 includes a plurality of types of ultraviolet light emitting diodes 24 b and 24 c that irradiate ultraviolet rays U having different wavelengths in the ultraviolet light region. It is arranged in a ring shape corresponding to the convex portion C. As shown in FIG. 6, the ultraviolet irradiation means 22 is formed by arranging a plurality of types of ultraviolet light emitting diodes 24 b and 24 c in a ring shape corresponding to the annular convex portions C, respectively. In the example shown in FIG. 6, two types of ultraviolet light emitting diodes 24b and 24c are provided, and these two types of ultraviolet light emitting diodes 24b and 24c are alternately arranged. The ultraviolet light emitting diode 24b emits ultraviolet light U having a wavelength of 395 nm, and the ultraviolet light emitting diode 24c emits ultraviolet light U having a wavelength of 365 nm. Further, in the present invention, three or more kinds of ultraviolet light emitting diodes 24b and 24c may be provided, and a plurality of kinds of ultraviolet light emitting diodes 24b and 24c may be alternately arranged for each plurality, or randomly arranged. Also good.

  Moreover, in the ultraviolet irradiation apparatus 2 which concerns on the modification 2, the wavelength suitable according to the kind of adhesive layer A of the protective tape T among several types of ultraviolet light emitting diodes 24b and 24c, ie, the wavelength which is easy to harden the adhesive layer A The ultraviolet light emitting diodes 24b and 24c are turned on. In the present invention, all of the plurality of types of ultraviolet light emitting diodes 24b and 24c may be turned on simultaneously, and one or more types of the ultraviolet light emitting diodes 24b and 24c among the plurality of types of ultraviolet light emitting diodes 24b and 24c are turned on. Just do it.

  The ultraviolet irradiation device 2 according to the modified example 2 is an extra portion other than the portion attached to the lower surface of the annular convex portion C of the adhesive layer A of the protective tape T, similarly to the ultraviolet irradiation device 2 of the above-described embodiment. Irradiation with ultraviolet rays U can be suppressed, and the ultraviolet rays U can be efficiently and economically irradiated.

  Further, the wavelength of the ultraviolet ray U that is effectively cured differs depending on the type of the adhesive layer A of the protective tape T, and the plural types of ultraviolet light emitting diodes 24b and 24c that irradiate the ultraviolet ray U having different wavelengths in the ultraviolet light region are used as the ultraviolet ray Irradiation means 22 is provided. For this reason, since the ultraviolet irradiation apparatus 2 which concerns on the modification 2 can irradiate the ultraviolet-ray U of the suitable wavelength according to the kind of protective tape T, ultraviolet irradiation time can be shortened and productivity can be improved.

  Theoretically, the shorter wavelength side has higher energy and is likely to be cured faster. However, when the adhesive layer A is thick, it is absorbed and the ultraviolet rays U do not reach the inside, and only the surface of the adhesive layer A is cured. Sometimes it doesn't work as a whole. However, since the ultraviolet irradiation device 2 according to the modified example 2 can simultaneously illuminate a plurality of types of ultraviolet light emitting diodes 24b and 24c and irradiate ultraviolet rays U having a plurality of wavelengths, the surface of the adhesive layer A and the adhesive layer A The inside of can be cured in a short time.

  The present invention is not limited to the above embodiment. That is, various modifications can be made without departing from the scope of the present invention. For example, in the embodiment and the second modification, the ultraviolet light emitting diodes 24, 24b, and 24c are arranged only in the circumferential direction so as to correspond to the annular convex portion C. However, in the present invention, the ultraviolet light emitting diodes 24, 24b, and 24c are arranged. Two or more in the radial direction in addition to the circumferential direction may be arranged, and the ultraviolet irradiation means 22 may be arranged in a ring shape corresponding to the annular convex portion C. For example, as shown in FIG. 7, the ultraviolet light emitting diodes 24b and 24c may be arranged in a ring shape so that a plurality of types of ultraviolet light emitting diodes 24b and 24c that irradiate ultraviolet rays U of different wavelengths are arranged in the radial direction. good. In FIG. 7, the same parts as those in the embodiment and the second modification are denoted by the same reference numerals and the description thereof is omitted. Moreover, in the modification 1, the ultraviolet irradiation means 22 may use the ring-shaped fluorescent lamp of the equivalent magnitude | size corresponding to the cyclic | annular convex part C. FIG.

2 Ultraviolet irradiation device 21 Case 22 Ultraviolet irradiation means 23 Light shielding plate 24, 24b, 24c Ultraviolet light emitting diode 25 Ultraviolet light transmitting portion A Adhesive layer C Circular convex portion F Circular frame R Circular concave portion S Dividing groove T Protection tape U Ultraviolet W Wafer Wa Wafer unit

Claims (3)

A wafer having a circular concave portion formed on the back surface and an annular convex portion surrounding the circular concave portion and having a dividing groove formed at a boundary portion between the circular concave portion and the annular convex portion; and affixed to the back surface of the wafer In order to peel off the annular projection from a wafer unit comprising a protective tape having an adhesive layer that is cured by irradiating ultraviolet light, and an annular frame attached to the outer peripheral portion of the protective tape, the annular projection An ultraviolet irradiation device for irradiating ultraviolet rays onto a protective tape adhered to the lower surface of the part,
An ultraviolet irradiation means disposed in a ring shape corresponding to the annular projection,
A housing that is formed in a box shape with the top open and the ultraviolet irradiation means is disposed inside;
A light shielding plate that covers the opening of the housing and supports the wafer on the upper surface with the protective tape side down,
The ultraviolet light irradiation device, wherein the light shielding plate includes a ring-shaped ultraviolet light transmitting portion having a size equivalent to that of the annular convex portion of the wafer and is formed in a flat plate shape .   2. The ultraviolet irradiation device according to claim 1, wherein the ultraviolet irradiation means is formed by arranging a plurality of ultraviolet light emitting diodes in a ring shape equivalent to the size of the annular convex portion. The ultraviolet irradiation means is formed by arranging a plurality of types of ultraviolet light emitting diodes for irradiating ultraviolet rays having different wavelengths in the ultraviolet light region in a ring shape corresponding to the annular convex portions, respectively.
The ultraviolet light emitting device according to claim 2, wherein an ultraviolet light emitting diode having a wavelength suitable for the type of the adhesive layer of the protective tape is turned on.

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