Ultraviolet irradiation device

Prior to applying of ultraviolet rays to a surface of a wafer with a protective tape joined thereto that is placed and held on a holding table, an illumination sensor moves to a position below an ultraviolet irradiation unit having ultraviolet light emitting diodes arranged in one dimensional array to measure ultraviolet intensity in a position corresponding to a surface of the protective tape, and output voltage of each diode is controlled so as to maintain a uniform accumulated quantity of light in an area of the protective tape where ultraviolet rays are applied that is determined from the result of measurement and a turning velocity of the holding table.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to an ultraviolet irradiation device to irradiate an ultraviolet curable protective tape joined to a surface of the semiconductor wafer with ultraviolet rays for reducing adhesive force thereof prior to separation of the protective tape.

2. Description of the Related Art

Examples of methods for use in thinning a semiconductor wafer (hereinafter, simply referred to as a “wafer”) include a mechanical method such as grinding and polishing or a chemical method such as etching. These methods are used for processing a rear face of the wafer to obtain a thinner thickness thereof. Upon processing the wafer through these methods, the protective tape is joined to a surface of the wafer for protection with a wiring pattern formed thereon. The rear face of the ground wafer with the protective tape joined thereto is adhesively held on a ring frame via a support adhesive tape. Subsequently, the protective tape is separated from the surface of the wafer held on the ring frame.

The following method is known for separating a protective tape. That is, a separation tape having strong adhesive force is joined to a surface of a protective tape, and then the separation tape is separated. Consequently, the protective tape may be separated from a surface of a wafer together with the separation tape. See JPH05-63077A.

Moreover, an ultraviolet curable protective tape is used, and ultraviolet rays are applied to the protective tape prior to separation thereof, thereby obtaining the protective tape having reduced adhesive force. A device for irradiating the protective tape with ultraviolet rays is configured as following. That is, a wafer with the protective tape joined thereto is suction-held on a suction table capable of reciprocating along a guide rail. The ultraviolet irradiation device arranged in an upper side irradiates the protective tape with ultraviolet rays during reciprocation of the suction table. The ultraviolet irradiation device has ultraviolet light emitting diodes (hereinafter, appropriately referred to as “diodes”) arranged in rows and columns. See JP2006-40944A.

The above conventional device, however, has the following problems.

Specifically, the ultraviolet irradiation device need to reciprocate the suction table on the guide rail, which may result in an enlarged area for installation of the device.

In addition, uniform intensity of illumination throughout the surface of the wafer during in-line reciprocation on the guide rail requires diodes arranged in rows and columns beyond a diameter of the wafer. As a result, another problem may arise that the device increases in size and weight.

SUMMARY OF THE INVENTION

This invention provides an ultraviolet irradiation device having a reduced size that is incorporable into a conventional protective tape separation device and therefore has a simple construction.

This invention discloses an ultraviolet irradiation device for irradiating with ultraviolet rays an ultraviolet curable protective tape joined to a surface of a semiconductor wafer. The ultraviolet irradiation device includes a holding table to mount and hold the semiconductor wafer with the protective tape joined thereto, a drive mechanism to turn the holding table, ultraviolet light emitting diodes arranged at least in a radial direction of the semiconductor wafer, and a control unit to maintain a uniform accumulated quantity of light in an area of the protective tape where ultraviolet rays are applied.

According to the ultraviolet irradiation device of this embodiment, the diodes are arranged at least in the radial direction of the wafer. For instance, the diodes may be arranged in a line, and the holding table may turn, thereby obtaining a uniform accumulated quantity of ultraviolet light over the entire surface of the protective tape joined to the surface of the wafer. That is, there is no need for the holding table to reciprocate along a guide rail. Moreover, the diodes need not to be arranged in row and columns beyond a diameter of the wafer. Consequently, the device may be reduced in size.

When the holding table turns, a peripheral velocity increases outwardly along the diameter from a center of the semiconductor wafer. Thus, the above device preferably has the following configuration so as to maintain the uniform accumulated quantity of ultraviolet light over the entire surface of the protective tape.

Supply voltage may be controlled such that intensity of the ultraviolet rays from the diodes increases outwardly from the center of the semiconductor wafer.

The device may be configured such that a distance from the surface of the protective tape to the diodes decreases outwardly from the center of the semiconductor wafer. With this configuration, illumination of the ultraviolet rays increases in an outer portion at which a level of the diode is lower than that at the center of the wafer and thus has a smaller distance to the surface of the protective tape. Therefore, the intensity of the ultraviolet rays also increases.

The device preferably includes the following configuration for setting each level of the diodes. That is, the device further includes a sensor to measure intensity of ultraviolet rays from the diodes, a lifting mechanism to change each level of the diodes, and a level controller to control each level of the diodes based on detected result of the sensor through operation of the lifting mechanism so as to maintain a uniform accumulated quantity of light per area on the surface of the protective tape.

With this configuration, the accumulated quantity of ultraviolet light per area on the surface of the protective tape may be controlled with higher accuracy based on illumination determined by the sensor.

Consequently, the protective tape may be irradiated with the ultraviolet rays constantly in a stable condition regardless of environmental variations upon irradiation of the ultraviolet rays.

For maintaining a constant accumulated quantity of ultraviolet light over the entire surface of the protective tape, the diodes may be arranged so that spaces therebetween may be smaller outwardly of the semiconductor wafer.

With this configuration, the spaces between the diodes may be smaller toward an outer periphery the semiconductor wafer, and thus spots of the ultraviolet rays from adjacent diodes are to overlap each other. Consequently, an outer periphery side with faster peripheral velocity than a center side of the semiconductor wafer has stronger intensity of the ultraviolet rays per area than the center side thereof, which realizes a uniform accumulated quantity of light over the entire surface of the protective tape.

In another aspect, the device may further have a lighting control unit to control the diodes so as to perform intermittent lighting separately such that a lighting duration of each diode may extend outwardly of the semiconductor wafer.

In each configuration, the device may further have a screen having a slit formed therein that fans outwardly from the center of the semiconductor wafer such that the surface of the protective tape may be irradiated with the ultraviolet rays from the diodes through the slit of the screen.

With this configuration, the ultraviolet rays that spread radically may pass through the slit of the screen, and thus the protective tape may be irradiated with only a component of the ultraviolet rays having high intensity. Consequently, a uniform accumulated quantity of ultraviolet light may be realized over the entire surface of the protective tape.

The device may further have a filter with increasing ultraviolet transmittance outwardly of the semiconductor wafer such that the surface of the protective tape may be irradiated with the ultraviolet rays from the diodes through the filter.

This configuration may also realize a uniform accumulated quantity of ultraviolet light over the entire surface of the protective tape.

In each configuration, the device preferably has an auxiliary ultraviolet light emitting diode to irradiate a peripheral edge of the protective tape.

The adhesive of the ultraviolet curable protective tape may possibly protrude beyond the peripheral edge of the wafer upon joining of the protective tape to the wafer. When the adhesive is cured using conventional devices, irradiation with ultraviolet rays is performed while nitrogen is purged into a chamber for removal of oxygen as a factor that prevents curing. Here, the adhesive is to be directly irradiated with ultraviolet rays having high intensity. Thus, it has been found through this configuration that the adhesive may be cured with no nitrogen purged.

With this configuration, an edge of the wafer may be irradiated with the ultraviolet rays having higher intensity than that applied on the entire surface of the protective tape. That is, all the adhesives may be cured to an approximately identical extent, and adhesive force thereof may be reduced. Consequently, elimination may be realized of damages on the wafer due to an uncured adhesive on the wafer edge and residues of the adhesive on the wafer edge when the protective tape is to be separated in a subsequent process.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

One exemplary embodiment of a semiconductor wafer mounting apparatus including an ultraviolet irradiation device of this invention will be described in detail hereinafter with reference to the drawings.

FIG. 1is a partially cutaway perspective view showing an overall of a semiconductor wafer mounting apparatus in one embodiment of the invention.

The semiconductor wafer mounting apparatus1includes a wafer supply section2with cassettes C placed therein, a wafer transport mechanism3with a robot arm4and a pressing mechanism5, an alignment stage7, an ultraviolet irradiation device9, a chuck table15, a ring frame supply section16, a ring frame transport mechanism17, a tape processing section18, a ring frame lifting mechanism26, a mount frame manufacturing section27, a first mount frame transport mechanism29, a separating mechanism30, a second mount frame transport mechanism35, a turntable36, and a mount frame collecting section37. The wafer supply section2has cassettes C to house a semiconductor wafer (hereinafter, simply referred to as a “wafer W”) to which a back grinding process has been performed in a stack manner. The wafer W has a surface with a protective tape joined thereto. The alignment stage7performs alignment of the wafer W. The ultraviolet irradiation device9irradiates the wafer W mounted on the alignment stage7with ultraviolet rays. The chuck table15suction holds the wafer W. The ring frame supply section16has a ring frame f housed therein in a stack manner. The ring frame transport mechanism17moves to mount the ring frame f onto an adhesive tape DT as a dicing tape. The tape processing section18joins the adhesive tape DT to a rear face of the ring frame f. The ring frame lifting mechanism26moves vertically the ring frame f with the adhesive tape DT joined thereto. The mount frame manufacturing section27manufactures a mount frame MF produced in one piece by joining the wafer W to the ring frame f with the adhesive tape DT joined thereto. The first mount frame transport mechanism29transports the manufactured mount frame MF. The separating mechanism30separates the protective tape PT joined to the surface of the wafer W. The second mount frame transport mechanism35transports the mount frame MF with the protective tape PT separated therefrom with the separation mechanism30. The turntable36turns and transfers the mount frame MF. The mount frame collecting section37collects the mount frame MF in a stack manner.

The wafer supplying section2includes a cassette table. The wafer W has a pattern surface (hereinafter appropriately referred to as a “surface”) with the protective tape PT joined thereto. The cassette C with the wafers W housed therein in a stack manner is placed on the cassette table. Here, each of the wafers W is kept horizontal with the pattern surface thereof directed upward.

The wafer transport mechanism3turns and moves vertically with a drive mechanism. Specifically, the wafer transport mechanism3performs positioning of a wafer holder of the robot arm4and a pressure plate6provided in the pressing mechanism5. Moreover, the wafer transport mechanism3pulls out the wafer W from the cassette C, and transports the wafer W to the alignment stage7.

The robot arm4of the wafer transport mechanism3has at its tip end a U-shaped wafer holder. The robot arm4is configured such that the wafer holder may move backward and forward between the wafers W housed in the cassette C in a stack manner. Here, the wafer holder at the tip end of the robot arm4has a vacuum suction hole to perform vacuum suction on the rear face of the wafer W.

The pressing mechanism5of the wafer transport mechanism3has at its end a circular pressure plate6of an approximately similar shape to the wafer W. The robot arm4moves backward and forward such that the pressure plate6moves above the wafer W placed on the alignment stage7.

The pressing mechanism5operates in poor suction of the wafer W upon placing the wafer W on the holding table8of the alignment stage7. Specifically, where the wafer W cannot be suction-held due to warping thereof, the pressure plate6presses the surface of the wafer W to correct the warping, allowing the wafer to be planar. The holding table8performs vacuum suction on the rear face of the wafer W under this state.

The alignment stage7performs alignment of the placed wafer W based on an orientation mark or a notch formed at an outer periphery of the wafer W. The alignment stage7includes the holding table8to cover the entire rear face of the wafer W for performing vacuum suction, and a motor M to turn the holding table8.

The alignment stage7may move so as to transport the wafer W in a suction-held state from an initial position to an intermediate position. In the initial position, the wafer W is placed to perform alignment. The intermediate position is between the chuck table15and the ring frame lifting mechanism26above the tape processing section18. In other words, the alignment stage7transports the wafer W to a subsequent process in a planar state with the warping thereof being corrected.

An ultraviolet irradiation device9is provided above the alignment stage7in the initial position. The ultraviolet irradiation device9irradiates with ultraviolet rays the protective tape PT, i.e., an ultraviolet curable adhesive tape joined to the surface of the wafer W. Irradiation with ultraviolet rays leads to curing of an adhesive in the protective tape, thereby reducing adhesive force thereof. See,FIGS. 2 and 3.

Specifically, the ultraviolet ray irradiation device9includes an ultraviolet irradiation unit12and an illumination sensor14. The ultraviolet irradiation unit12has ultraviolet light emitting diodes (hereinafter simply referred to as “diodes”)11arranged at given intervals in one dimensional array along a support plate extending outwardly from a base on a center side of the alignment stage7. The illumination sensor14moves to a position below the ultraviolet irradiation unit12to measure ultraviolet intensity.

Each diode11of the ultraviolet irradiation unit12has a power amplifier13. The power amplifier13converts ultraviolet intensity measured by the illumination sensor14into output voltage calculated by a computing unit57in a controller56. That is, an accumulated quantity of ultraviolet light is obtained from the ultraviolet intensity and a peripheral velocity in each ultraviolet irradiation position. The peripheral velocity in a radial direction of the wafer is measured from a turning velocity of the holding table8. The output voltage from each diode11is controlled such that the accumulated quantity of ultraviolet light may be maintained constant in the entire surface of the protective tape PT, as shown inFIG. 4.

The illumination sensor14may be formed of individual illumination sensors arranged in series or at equal intervals. Moreover, the illumination sensor14may be formed of a line sensor. The illumination sensor14has an ultraviolet receptor. The illumination sensor14is attached to an axis Z capable of lifting and rotating at a position slightly shifted to the right in plane from a center of the wafer such that the receptor reaches to the center thereof. That is, the illumination sensor14is configured to determine the ultraviolet intensity at a surface level of the wafer where the holding table8of the alignment stage7holds the wafer and turns for alignment and at a position opposite to the ultraviolet irradiation unit12.

Turning toFIG. 1, the chuck table15has a circular shape approximately similar to the wafer W so as to cover the surface of the wafer W for performing vacuum suction. The chuck table15moves vertically from a standby position above the tape processing section18to a position where the wafer W is joined to the ring frame f. The chuck table15suction-holds the wafer W held in a planar state with the warping thereof corrected by the holding table8.

The chuck table15is received in an opening of the ring frame lifting mechanism26, to suction-hold the ring frame f with the adhesive tape DT joined to the rear face thereof. Thereafter, the wafer W moves downward to a position adjacent the adhesive tape DT joined to the underside of the ring frame f. Here, a holding mechanism, holds the chuck table15and ring frame lifting mechanism26.

The ring frame supply unit16has a wagon shape with casters on the bottom thereof, and is housed in a body of the device. The ring frame supply unit16has an opening on an upper side thereof to slidingly move upward and feed out the ring frame f housed therein in a stack manner.

The ring frame transport mechanism17performs vacuum suction on every one ring frame f housed in the ring frame supply unit16in turn from the top, and transports the ring frame f to the alignment stage and the position of joining the adhesive tape DT, in turn. The ring frame transport mechanism17serves as a holding mechanism to hold the ring frame f in the position of joining the adhesive tape DT upon joining of the adhesive tape DT.

The tape processing section18includes a tape supply unit19, a tension mechanism20, a joining unit21, a cutter mechanism24, a separating unit23, and a tape collecting section25. The tape supply unit19supplies the adhesive tape DT. The tension mechanism20applies tension to the adhesive tape DT. The joining unit21joins the adhesive tape DT to the ring frame f. The cutter mechanism24cuts the adhesive tape DT joined to the ring frame f. The separating unit23separates an unnecessary tape cut with the cutter mechanism24from the ring frame f. The tape collecting section25collects remainder of the cut unnecessary tape.

The tension mechanism20sandwiches the adhesive tape DT on opposite ends in a width direction to apply tension to the adhesive tape DT in a tape width direction. When a soft adhesive tape DT is used, tension applied to a tape supply direction may cause occurrence of a longitudinal wrinkle on the surface of the adhesive tape DT along the tape supply direction. In order to avoid the longitudinal wrinkle so as to join the adhesive tape DT uniformly to the ring frame f, the tension mechanism20applies tension on the opposite ends in the tape width direction.

The joining unit21is placed obliquely downwardly from the ring frame f, above the adhesive tape DT, i.e., in the standby position. The joining unit21has a joining roller22. The ring frame transport mechanism17holds to transport the ring frame f into the joining position of the adhesive tape DT. Subsequently, the tape supply unit19starts to supply the adhesive tape DT, and simultaneously the joining roller22moves to a joining start position on the right of the tape supply direction.

Subsequently, the joining roller22in the joining start position moves upward and rolls from the joining start position toward the standby position, thereby joining the adhesive tape DT to the ring frame f while pressing.

The separation unit23separates the unnecessary portion of the adhesive tape DT cut with the cutter mechanism24from the ring frame f. Specifically, after joining the adhesive tape DT to the ring frame f and cutting the adhesive tape DT, the tension mechanism20releases holding of the adhesive tape DT. Subsequently, the separation unit23moves toward the tape supply unit19on the ring frame f, thereby separating the cut unnecessary adhesive tape DT.

The cutter mechanism24is placed below the adhesive tape DT joined to the ring frame f. When the joining unit21joins the adhesive tape DT to the ring frame f, the tension mechanism20releases holding of the adhesive tape DT, and the cutter mechanism moves upward. The cutter mechanism24after moving upward cuts the adhesive tape DT along the ring frame f.

The ring frame lifting mechanism26is placed in the standby position above a position where the adhesive tape DT is joined to the ring frame f. After joining of the adhesive tape DT to the ring frame f, the ring frame lifting mechanism26moves downward to suction-hold the ring frame f. At this time, the ring frame transport mechanism17holding the ring frame f returns to its initial position above the ring frame supply unit16.

After suction-holding the ring frame f, the ring frame lifting mechanism26moves upward to a position of joining the wafer W. At this time, the chuck table15holding the wafer W also moves downward to the position of joining the wafer W.

The mount frame manufacturing section27has a joining roller28with an outer peripheral surface that is elastically deformable. The joining roller28rolls on a non-adhesive surface of the adhesive tape DT joined to the rear face of the ring frame f while pressing.

The first mount frame transport mechanism29performs vacuum suction on the mount frame MF that the ring frame f is formed in one piece with the wafer W, and moves to mount the mount frame MF onto the separation mechanism30.

The separating mechanism30includes a separation table, a tape supply section31, a separating unit32, and a tape collecting section34. The separation table moves the wafer W mounted thereon. The tape supply section31supplies a separation tape Ts. The separation unit32joins and separates the separation tape Ts. The tape collecting section34collects the separated separation tape Ts and the protective tape PT.

As shown inFIG. 5, the tape supplying unit31guides and supplies the separation tape Ts fed out from the original master roll to a lower side of the separation unit32. The tape collecting section34guides upward the separation tape Ts fed out from the separation unit32so as to wind up and collect the separation tape Ts.

The separation unit32has a sharp edge41and a guide roller42. The edge41serves as joining and separating members of the separation tape Ts. The guide roller42guides the separation tape Ts folded back at a tip end of the edge41toward the tape collecting section34.

Turning toFIG. 1, the second mount frame transport mechanism35performs vacuum suction on the mount frame MF fed out from the separating mechanism30, and moves to mount the mount frame MF onto a turntable36.

The turntable36aligns the mount frame MF, and houses the mount frame MF in the mount frame collecting section37. Specifically, the second mount frames transport mechanism35places the mount frame MF on the turntable36, and then the turntable36aligns the mount frame MF based on an orientation mark of the wafer W or a positioning contour of the ring frame f. The turntable36turns so as to change a direction in which the mount frame MF is housed in the mount frame collecting section37. When the direction for housing the mount frame MF is fixed, the turntable36pushes out the mount frame MF with a pusher to house the mount frame MF in the mount frame collecting section37.

The mount frame collecting section37is placed on a mount table capable of moving vertically. Specifically, moving vertically of the mount table allows the mount frame MF pushed out with the pusher to be housed on any sections in the mount frame collecting section37.

Description will be made hereinafter of a round of operation about the above apparatus according to one embodiment.

Firstly, settings of each mechanism in the semiconductor wafer mounting apparatus1are inputted into the controller56via an operating panel. For instance, a type of protective tape PT is inputted. Upon input of the type of protective tape PT, the controller56reads out a corresponding accumulated quantity of ultraviolet light databased in advance from a memory therein. Simultaneously, a drive mechanism operates to move the illumination sensor14to a position of measurement.

When movement of the illumination sensor14is completed, the ultraviolet irradiation unit12operates to perform an initial measurement while the holding table8turns. The result of the measurement detected by the illumination sensor14facing to each of the diodes11is transmitted to the controller56. The computing unit57in the controller56determines a peripheral velocity at an opposite position to the diodes11arranged radically in a line in accordance with the turning velocity of the holding table8set in advance. Subsequently, output voltage is determined for every power amplifier13of the diodes11when an accumulated quantity of ultraviolet light in the protective tape PT in each irradiation position is constant and the adhesive of the protective tape PT is curable in a shortest duration. After completing the measurement, the illumination sensor14returns to its upper standby position apart from the determination area.

Upon fixing of ultraviolet irradiation conditions, the robot arm4operates so that the wafer holder is inserted between the stacked wafers W in the cassette C. The wafer W is suction-held on the rear face thereof, and pulled out for every one wafer. The pulled out wafer W is transported to the alignment stage7.

The robot arm4places the wafer W on the holding table8to suction-hold the rear face of the wafer W. In this state, a pressure gauge, measures a level where the wafer W is suction-held. A comparison is made of the measurement result and the predetermined reference value in relation to a pressure value in a normal operation.

When poor suction holding is detected from the result of the comparison, the pressure plate6presses a surface of the wafer W. Consequently, the wafer W in a planar state with corrected warping may be suction-held. In addition, the wafer W is aligned based on the orientation mark or the notch.

The ultraviolet irradiation unit12provided with the diodes11each having individually different output irradiates the protective tape PT with ultraviolet rays when the holding table8turns for detection of the orientation mark or notch of the wafer W. Although irradiation intensity differs for every ultraviolet irradiation area on the protective tape PT, the accumulated quantity of light of ultraviolet light is maintained constant in the entire irradiation area, thereby uniformly reducing the adhesive force of the adhesive.

The wafer W is aligned on the alignment stage7and subjected to an irradiation treatment of ultraviolet rays, and thereafter is transported, along with the alignment stage7, to the mount frame manufacturing unit27at a subsequent step while being suction-held on the holding table8. That is, the alignment stage7moves to an intermediate position between the chuck table15and the ring frame lifting mechanism26.

When the alignment stage7is set standby in a predetermined position, the chuck table15located above the alignment stage7moves downward to contact a bottom face thereof with the wafer W, thereby starting vacuum suction. When the chuck table15starts vacuum suction, the holding table8releases its suction holding of the wafer W. The chuck table15receives the wafer W in a planar state with the warping thereof corrected by the holding table8. After transporting the wafer W, the alignment stage7returns to its initial position.

Next, the ring frame transport mechanism17performs vacuum suction on every ring frame f from the top that is housed in the ring frame supply section16in a stack manner, and then pulls out the ring frame f. The pulled-out ring frame f is aligned on an alignment stage, and then transported to a tape joining position above the adhesive tape DT.

The ring frame transport mechanism17holds the ring frame f and moves the ring frame f into the joining position of the adhesive tape DT, and then a tape supply section19starts to supply the adhesive tape DT. Simultaneously, the joining roller22moves into a joining start position.

When the joining roller22reaches into the joining start position, the tension mechanism20holds the opposite ends of the adhesive tape DT in the tape width direction, thereby applying tension to the adhesive tape DT in the tape width direction.

Next, the joining roller22moves upward to press and join the adhesive tape DT onto the end of the ring frame f. After joining the adhesive tape DT to the end of the ring frame f, the joining roller22rolls toward the tape supply section19, i.e., to a standby position. Here, the joining roller22rolls while pressing the non-adhesive surface of the adhesive tape DT, thereby joining the adhesive tape DT to the ring frame f. When the joining roller22reaches at its joining termination position, the tension mechanism20releases holding of the adhesive tape DT.

Simultaneously, the cutter mechanism24moves upward to cut the adhesive tape DT along the ring frame f. Upon completion of cutting the adhesive tape DT, the separation unit23moves toward the tape supply section19, thereby separating the unnecessary adhesive tape DT.

Subsequently, the tape supply section19operates to feed out the adhesive tape DT while feeding out the unnecessary tape to the tape collecting section25. In this state, the joining roller22moves into the joining start position so as to join the adhesive tape DT to another ring frame f.

The ring frame lifting mechanism26moves upward while suction holding a frame portion of the ring frame f with the adhesive tape DT joined thereto. Here, the chuck table15also moves downward. That is, the chuck table15and the ring frame lifting mechanism26each move into the joining position of the wafer W.

Upon reaching at a predetermined position, each of the chuck table15and the ring frame lifting mechanism26is held with a holding mechanism. Next, the joining roller28moves into a joining start position of the adhesive tape DT. The joining roller28rolls while pressing the non-adhesive surface of the adhesive tape DT joined to the rear face of the ring frame f, thereby joining the adhesive tape DT to the wafer W. Consequently, the mount frame MF may be manufactured that the ring frame f and the wafer W are formed in one piece.

After manufacturing of the mount frame MF, the chuck table15and the ring frame lifting mechanism26move upward. The holding table also moves below the mount frame MF and places the mount frame MF thereon. The first mount frame transport mechanism29suction-holds the placed mount frame MF, and moves to place the mount frame MF onto the separation table.

The separation table with the mount frame MF placed thereon moves forward below the separation unit32. In this process, a pulse motor controls a position of the separation table at the time when a light sensor detects a front edge of the protective tape PT such that the separation table moves forward from the detected position by a distance determined in advance from the light sensor to the edge member41. Here, the separation table once stops forward movement. Specifically, the separation table once stops forward movement automatically upon reaching of the front edge of the protective tape PT at a position below the tip end of the edge member41.

Once the separation table stops, the pulse motor operates to control the movable table to move downward such that the edge member41moves downward with the separation tape Ts supplied from the tape supply unit31being wounded thereon. That is, the separation tape Ts is joined to the front end surface of the protective tape PT at a given pressure while being pushed with the tip end of the edge member41.

When joining of the separation tape Ts to the front end of the protective tape PT is completed, the separation table starts forward movement again while the edge member41presses the separation tape Ts against the protective tape PT. Moreover, the separation tape Ts is wound up to the tape collecting section34at a speed synchronized to a traveling velocity of the mount frame MF. In this way, the edge member41joins the separation tape Ts to the protective tape PT on the surface of the wafer W while pressing. Simultaneously, the edge member41separates the protective tape PT from the surface of the wafer W together with the joined separation tape Ts while separating the separation tape Ts.

The pulse motor operates to control the edge member41so as to move by a distance corresponding to a diameter of the wafer from a separation tape joining position where the edge member41moves downward. Specifically, when the edge member41reaches into the rear edge of the protective tape PT and completely separates the protective tape PT from the surface of the wafer W, the edge member41moves upward and the separation unit32returns to its initial state.

After the protective tape PT is separated from the mount frame MF, the separation table moves the mount frame MF to the standby position of the second mount frame transport mechanism35.

Subsequently, the second mount frame transport mechanism35moves to place the mount frame MF fed out from the separation mechanism30onto the turntable36. The placed mount frame MF is aligned using the orientation mark or the notch, and a direction of the mount frame MF to be housed is adjusted. After performing alignment of the mount frame MF and determination in the direction thereof to be housed, a pusher pushes out to house the mount frame MF in the mount frame collecting section37.

As mentioned above, the diodes11are arranged outwardly from the center side of the wafer W in one-dimensional array, output voltage of each diode11increases outwardly from the center side of the wafer W, and the output voltage of each diode11is controlled in accordance with the peripheral velocity. Consequently, an accumulate quantity of light in the entire surface of the protective tape that is irradiated with ultraviolet rays may be maintained constant. Therefore, remainder of the adhesive on the surface of the wafer surface may be eliminated that occurs from poor curing of the adhesive upon separating of the protective tape PT.

Moreover, the diodes11need not to be arranged in row and columns beyond the diameter of the wafer W, and the holding table8only need to turn in a predetermined position. Thus, the configuration of the apparatus may be reduced in size.

This invention is not limited to the foregoing embodiments, but may be modified as follows.

In the exemplary embodiment described above, the output voltage of each diode11is controlled using the illumination sensor14prior to operation of the semiconductor wafer mounting apparatus1. The ultraviolet intensity to an appropriate number or all of the wafers W subject to treatment may be measured before alignment, and the output voltage of each diode11may be controlled.

In the exemplary embodiment described above, the ultraviolet irradiation unit12and illumination sensor14are formed in one piece. The ultraviolet irradiation unit12and illumination sensor14may be separately formed.

In the exemplary embodiment described above, an accumulate quantity of ultraviolet light is maintained constant by control of the output voltage of the diodes11while fixing the distance from the surface of protective tape PT to each diode11. The distance from the surface of protective tape PT to each diode11may be controlled while fixing the output voltage of the diodes11.

The peripheral velocity increases outwardly from the center of the wafer W. Therefore, in order to obtain the same accumulate quantity of ultraviolet light between the outside portion and the center side of the wafer W, a distance from the surface of the protective tape PT to the diodes11may decrease outwardly from the center of the wafer, as shown inFIG. 6.

In another exemplary embodiment, actuators60control to change the level of each diode11, as shown inFIG. 7. In this configuration, the illumination sensor14is moved to a position of measurement, the output of each diode is fixed, and then ultraviolet rays are applied. Here, the level of each diode11is determined upon measurement of the ultraviolet intensity where the accumulate quantity of light obtained from turning of the holding table8and the ultraviolet intensity is maintained constant in the entire irradiation areas. Each actuator60operates in accordance with the result of measurement to move each diode11to a given level. This configuration may produce the same effect as in the exemplary embodiments described above.

In each of the exemplary embodiments described above, a screen62may be arranged between the ultraviolet irradiation unit12and wafer W. As shown inFIGS. 8 and 9, the screen62has a fan-shaped slit61formed therein that spreads outwardly from the center of the wafer W.

According to this configuration, the slit has a lower peripheral turning velocity and a smaller opening area in the center side of the wafer W, leading to ultraviolet light with a reduced diameter of the spot SP. On the other hand, the slit has a higher peripheral turning velocity and a larger opening area toward the periphery of the wafer W. Consequently, a constant accumulated quantity of light may be realized in the entire area of the protective tape PT where ultraviolet rays are applied.

As shown inFIG. 10, a filter63may be arranged between the ultraviolet irradiation unit12and the holding table8in which ultraviolet transmittance thereof increases outwardly from the center of the wafer W. For instance, only the filter63may be arranged. Moreover, the filter63may be provided according to the slit61of the screen62in the above exemplary embodiment.

As shown inFIG. 11, a timing controller64may control timing for switching of the power amplifier13in each diode11to maintain a constant accumulated quantity of light in the entire area of the protective tape PT where ultraviolet rays are applied. Specifically, lighting duration of the diodes11may be controlled so as to extend outwardly of the wafer W compared to the center of the wafer W having a lower peripheral turning velocity.

The diodes11may be arranged such that the spaces therebetween may be smaller outwardly from the center of the wafer W. Specifically, as shown inFIG. 12, smaller spaces between the diodes11on the outside portion pf the wafer having a higher turning velocity may lead to overlapping of the radial ultraviolet spots, thereby realizing increased ultraviolet intensity.

Moreover, the actuator connected to every diode11or an individual drive mechanism may move each diode11radically along a guide rail. With this configuration, the spaces between the diodes may vary optionally and the diodes may operate effectively upon changing the wafer W in size.

The foregoing exemplary embodiments have been described by taking the ultraviolet irradiation unit12having the diodes11arranged in one-dimensional array as an example. The ultraviolet irradiation unit12may be configured as follows. Specifically, as shown inFIG. 13, the ultraviolet irradiation unit12of each exemplary embodiment described above may have the diodes11arranged in a fan shape.

In each exemplary embodiment described above, the diodes11are arranged above the wafer W. The diodes11may be arranged as follows. Specifically, as shown inFIG. 14, a diode11amay be arranged for applying ultraviolet rays to the edge of the wafer W. For instance, when ultraviolet rays are applied while nitrogen is purged into a chamber with the whole alignment stage7housed therein, the ultraviolet irradiation unit12may irradiate the edge of the wafer with ultraviolet rays from the diode11aat an approximately identical output to that of the diode11on the outermost periphery side of the wafer W.

Where the ultraviolet irradiation unit12applies ultraviolet rays while being open to the atmosphere with no nitrogen being purged, oxygen in the atmosphere prevents the adhesive from being cured. Thus, the ultraviolet irradiation unit12controls so as to apply ultraviolet rays having higher intensity than that on the surface of the wafer W.

With this configuration, all the adhesives may be cured uniformly and the adhesive force thereof may be reduced. Consequently, suppression may be made of damages on the wafer due to an uncured adhesive on the wafer edge and residues of the adhesive on the wafer edge upon separation of the protective tape in a subsequent process.