JP2008227118A - Mounting device and its control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mounting device that highly accurately mounts balls onto a workpiece. <P>SOLUTION: The mounting device has a base 2, a mask holder 22 for holding a mask 21 at a first position with respect to the base 2, a transfer stage 3 capable of moving a workpiece 90 to a prescribed position with respect to the base 2, first cameras 51a, 51b that detect a reference mark of the workpiece 90 in a state of being mounted on the transfer stage 3 so as to record the position of the workpiece 90 with respect to the transfer stage 3 as a workpiece reference position in a memory, a second camera 52 that acquires an image of each electrode, facing each minute opening, of the workpiece 90 via each minute opening of the mask 21 from above the mask 21 held by the mask holder 22, ball dispensers 23a, 23b for filling each ball Be into each minute opening of the mask 21 from above the mask 21 held by the mask holder 22, and a control unit capable of controlling a moving destination of the transfer stage 3. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a mounting apparatus for mounting a ball on a plurality of electrodes of a workpiece, and a control method therefor.

  In order to obtain an electrical connection when mounting a semiconductor device, a conductive ball such as a solder ball may be used. Patent Document 1 discloses an apparatus for mounting conductive balls on a wafer. In this Patent Document 1, an array mask having a through hole into which a conductive ball enters is disposed above a wafer placed on a stage, and a ball reservoir for storing a plurality of conductive balls having an opening on a lower surface is provided. A conductive ball mounting device is disclosed in which a conductive ball is mounted by placing and moving a ball reservoir along an array mask and dropping the conductive ball into each through hole of the array mask. In this conductive ball mounting apparatus, a vertical observation camera for observing alignment marks of a wafer and a print mask and aligning the wafer and the print mask is provided in the flux printing unit. At the same time, a vertical observation camera for observing alignment marks of the wafer and the ball arrangement mask and aligning the wafer and the ball arrangement mask is provided on the ball mounting portion.

  According to this conductive ball mounting apparatus, the conductive balls are mounted on the wafer as follows. First, in the primary alignment unit, the wafer is rotated, the position of the orientation flat or notch is detected, the rough position of the wafer is corrected, and the orientation flat or notch is set to a predetermined position. The wafer whose position has been corrected is placed on the stage from the primary alignment unit.

  Next, the stage on which the wafer is placed is moved to the flux printing unit. The alignment marks of the wafer and the printing mask are observed with the vertical observation camera, the wafer and the printing mask are positioned in the XYZθ directions, and the flux is printed on the electrodes of the wafer. Thereafter, the stage on which the wafer is placed is moved to the ball mounting portion. The alignment marks on the wafer and the ball array mask are respectively observed by the vertical observation camera, and the wafer and the ball array mask are positioned in the XYZθ directions. Then, the conductive ball is dropped into the through hole of the ball arrangement mask, and the conductive ball is mounted on the wafer.

Since the diameter of the through hole of the ball arrangement mask is formed larger than the diameter of the conductive ball, the position of the conductive ball in the through hole can be obtained simply by dropping the conductive ball into the through hole of the arrangement mask. Is not complete. For this reason, in this conductive ball mounting apparatus, after dropping the ball, the stage is linearly finely moved in the horizontal direction with respect to the ball arrangement mask to align the positions of the conductive balls.
JP 2006-310593 A

  In conventional mounting equipment that mounts balls, coarse alignment (pre-alignment) is performed when a workpiece is placed on the stage, and the mask alignment mark and workpiece alignment mark are observed by a camera to align the mask and workpiece. It is carried out.

  In recent years, the diameter of balls (conductive balls, solder balls, metal balls) mounted on workpieces has become smaller, and accordingly, high precision is required for alignment between the mask and workpiece. Yes. For example, when the ball diameter is 100 μm or less, the flux application process is performed even if the flux application mask and the workpiece are aligned by observing the alignment mark of the flux application mask and the alignment mark of the work. In this case, the flux may be displaced with respect to the workpiece electrode. Similarly, even if the ball mounting mask and the workpiece are aligned by observing the alignment mark of the ball mounting mask and the workpiece alignment mark, the ball is displaced from the workpiece electrode in the ball filling process. May end up.

  These are used to mount microballs with diameters on the order of several hundreds to several tens of micrometers and even smaller than the measurement accuracy of the position determined from the alignment mark of the workpiece and the measurement accuracy of the position determined from the alignment mark of the mask. When higher position measurement accuracy is required, and when observing in the order of the size of such a small ball, the position of the mask shifts over time, and the relative position of the mask and workpiece shifts. It is thought to be due to factors such as the phenomenon called drift.

  The flux is applied to the workpiece by aligning the flux application mask with the workpiece using the alignment mark, and the deviation between the applied flux and the electrode is obtained as an offset value or offset amount, and this offset value is used to apply the flux. A method of aligning the mask and the workpiece can be considered. Similarly, the alignment mark is used to align the ball mounting mask and the workpiece, and the ball is mounted on the workpiece. The deviation between the mounted ball and the electrode is obtained as an offset value or offset amount, and this offset value is used. A method of aligning the ball mounting mask and the workpiece can be considered.

  However, these methods increase the number of steps for aligning the mask and the workpiece. In addition, the workpiece used for obtaining the offset value cannot be reused without a process such as cleaning. In addition, since flux is actually applied to the workpiece or a ball is mounted, there is a risk of causing defects in the workpiece at the mask alignment stage or cleaning stage. Furthermore, the flux and balls used to obtain the offset value are wasted.

  One aspect of the present invention is a method of controlling a mounting device for mounting a ball on a plurality of electrodes of a workpiece having a plurality of electrodes on the surface by a control unit. The mounting apparatus includes a base and a ball mounting mask holder (mask holding means) for holding a ball mounting mask (mask plate) having a plurality of minute openings for mounting the ball on the workpiece against the base. , A transfer stage that holds (loads) the workpiece and can move the workpiece to a predetermined position relative to the base, a first camera that can detect a reference mark of the workpiece mounted on the transfer stage, and a ball mounting mask From the top of the ball mounting mask held by the holder, through the at least one minute opening of the ball mounting mask, an image of at least one electrode of the workpiece facing the at least one minute opening can be acquired. From the camera of 2 and the ball mounting mask held by the ball mounting mask holder, to the plurality of minute openings of the ball mounting mask It has a ball dispenser for filling Lumpur, and a controllable control unit the destination of the transfer stage.

This method includes performing the following operations (operations (steps)).
(1) Detecting a reference mark of the ball mounting mask held by the ball mounting mask holder by the second camera and recording the first position of the ball mounting mask with respect to the base in the memory;
(2) The first camera detects a reference mark of the workpiece mounted on the transfer stage, and records the position of the workpiece with respect to the transfer stage as a workpiece reference position in the memory.
(3) The workpiece is moved under the ball mounting mask held by the ball mounting mask holder by the transfer stage so that the workpiece reference position is determined by the first position, and the second A second position relative to the base of the workpiece reference position when at least one minute aperture of the ball mounting mask and at least one electrode facing the at least one minute aperture are aligned via the camera. Obtaining and recording the second position in memory;
(4) The workpiece is moved under the ball mounting mask held by the ball mounting mask holder by the transfer stage so that the workpiece reference position becomes the second position, and the ball is mounted by the ball dispenser. Filling several micro-openings in the mask.

  First, the ball mounting mask is held on the base serving as a reference for the position of various devices including the transfer stage in the ball mounting apparatus by detecting the reference mark of the ball mounting mask held by the ball mounting mask holder with the second camera. A first position of the mask is obtained. Further, the position of the workpiece (work reference position) with respect to the transfer stage can be obtained by detecting the reference mark of the workpiece mounted on the transfer stage with the first camera. Then, the ball mounting mask and the workpiece are aligned based on the first position which is the reference position of the ball mounting mask and the workpiece reference position. As a result, if it is assumed that the first position with respect to the base is determined (does not move), it becomes possible to align the ball mounting mask and the workpiece by detecting the workpiece reference position for each workpiece. There is no need to observe and align fiducial marks each time.

  However, if the positioning accuracy is such that the reference mark is aligned, there is a possibility that the position of the minute opening of the ball mounting mask and the position of the electrode of the workpiece will be displaced. This is because, as described above, the ball diameter to be mounted becomes smaller, and it is becoming impossible to cope with the alignment measurement accuracy using the reference mark, and the effect of a phenomenon such as drift appears when the ball diameter becomes smaller. Conceivable. Therefore, it is necessary to further improve the accuracy of alignment between the ball mounting mask and the workpiece.

  According to this method, the workpiece is moved under the ball mounting mask held by the ball mounting mask holder so that the workpiece reference position is determined by the first position by the transfer stage. Thus, the ball mounting mask and the workpiece are aligned. Furthermore, the position of the workpiece is finely adjusted via the second camera so that at least one minute opening of the ball mounting mask and at least one electrode facing the at least one minute opening coincide with each other. A second position with respect to the base of the workpiece reference position when finely adjusted is acquired, and the second position is recorded in the memory. This second position is a displacement between the state in which the workpiece and the ball mounting mask are aligned by the respective reference marks and the state in which the minute opening matches the electrode, that is, positional information including an offset value. .

  Therefore, after that, the workpiece is arranged so that the workpiece reference position becomes the second position with respect to the base, and the reference marks are used by actually mounting the ball on the workpiece via the ball mounting mask. The ball can be mounted in a state of alignment with higher accuracy than alignment.

  According to this method, when the workpiece is moved so that the workpiece reference position is determined by the first position, the position of the minute opening of the ball mounting mask and the position of the electrode of the workpiece are the same as those of the minute ball. Even if they are out of order, the second camera obtains an image of at least one electrode facing it through at least one minute aperture, and the position of at least one minute aperture and at least one electrode facing it. The workpiece is moved together with the transfer stage so that the positions of the two coincide with each other. As a result, the position of the workpiece with respect to the ball mounting mask can be finely adjusted with the order of minute openings, that is, the order of minute balls. For this reason, a ball, particularly a ball having a diameter of several hundreds to several tens of μm or less, can be satisfactorily mounted on the workpiece electrode in a state where there is no deviation or in a very small state.

  That is, according to this method, a state in which the ball is mounted on the electrode of the workpiece is simulated by acquiring an image of at least one electrode facing it through at least one minute opening with the second camera. The position of the workpiece can be finely adjusted. For this reason, it is possible to simulate the state of mounting the ball on the workpiece electrode without actually mounting the ball on the workpiece via the ball mounting mask, and to accurately align the ball mounting mask and the workpiece. It can be carried out.

  Another aspect of the present invention is a mounting device for mounting a ball on a plurality of electrodes of a workpiece having a plurality of electrodes on the surface. This mounting apparatus includes a ball mounting mask holder for holding a ball mounting mask (mask plate) having a base and a plurality of minute openings for mounting a ball on a workpiece in a first position with respect to the base. (Mask holding means), a carrier stage that holds (mounts) the workpiece, can move the workpiece to a predetermined position relative to the base, and detects a reference mark of the workpiece mounted on the carrier stage, and the workpiece on the carrier stage From the first camera that can be recorded in the memory with the position of the workpiece as a work reference position and the ball mounting mask held by the ball mounting mask holder, through at least one minute opening of the ball mounting mask A second camera capable of acquiring an image of at least one electrode of a workpiece facing at least one minute aperture; From the top of the ball mounting mask held in Kuhoruda has a ball dispenser for filling a ball into a plurality of minute openings ball mounting masks, and a controllable control unit the destination of the transfer stage.

  According to this mounting apparatus, the first position of the ball mounting mask with respect to the base and the position of the workpiece with respect to the transfer stage obtained by detecting the reference mark of the workpiece mounted on the transfer stage with the first camera. Using the (work reference position), the ball mounting mask and the work can be aligned. Specifically, by moving the workpiece below the ball mounting mask held by the ball mounting mask holder so that the workpiece reference position is determined by the first position by the transfer stage. In addition, the ball mounting mask and the workpiece can be aligned.

  Further, according to this mounting apparatus, when the work is moved so as to be determined by the first position, the position of the minute opening of the ball mounting mask and the position of the electrode of the work has a diameter of several. Even if it is shifted by an order of the size of a micro ball having a size of 100 μm or less and a micro aperture suitable for mounting them, the second camera faces it through at least one micro aperture of the ball mounting mask. By acquiring an image of at least one electrode, the position of the workpiece can be finely adjusted so that at least one minute aperture and at least one electrode facing the same coincide with each other. Then, the second position with respect to the base of the workpiece reference position when finely adjusted can be acquired and recorded in the memory.

  Further, according to this mounting apparatus, the workpiece can be arranged so that the workpiece reference position becomes the second position with respect to the base, and the ball can actually be mounted on the workpiece via the ball mounting mask. Specifically, the workpiece is moved under the ball mounting mask held by the ball mounting mask holder by the transfer stage so that the workpiece reference position becomes the second position, and the ball is mounted by the ball dispenser. A ball can be mounted on the workpiece via the ball mounting mask by filling a plurality of minute openings of the mask for use.

  Therefore, according to this mounting apparatus, the state in which the ball is mounted on the workpiece is obtained by acquiring an image of at least one electrode facing the second mounting camera through at least one minute opening of the ball mounting mask. Simulate and fine-tune the position of the workpiece. Therefore, the ball mounting mask and the workpiece are accurately aligned without actually mounting the ball on the workpiece via the ball mounting mask, and the ball is placed on the workpiece electrode without any deviation, or It can be mounted well with very little.

In order to simulate the state of mounting the ball on the workpiece, finely adjust the position of the workpiece, and then to actually mount the ball on the workpiece via the ball mounting mask, the control unit of this mounting device These functions are preferably included.
(A1) Under the ball mounting mask held by the ball mounting mask holder, the workpiece is moved by the transfer stage so that the workpiece reference position is determined by the first position, and the second A second position relative to the base of the workpiece reference position when at least one minute aperture of the ball mounting mask and at least one electrode facing the at least one minute aperture are aligned via the camera. Obtain and record in memory (first function).
(A2) Under the ball mounting mask held by the ball mounting mask holder, the workpiece is moved by the transfer stage so that the workpiece reference position becomes the second position, and the ball is mounted by the ball dispenser. Filling a plurality of minute openings of the mask for use so that the balls are mounted on the plurality of electrodes of the workpiece (second function).

  In this mounting apparatus, it is preferable that the second camera can detect the reference mark of the ball mounting mask and record the first position, which is the reference position of the ball mounting mask, in the memory. By doing so, the second camera can be used to acquire the reference mark of the ball mounting mask. That is, the second camera can be used to acquire the reference position of the ball mounting mask with respect to the base.

  Further, in this mounting apparatus, the second camera can acquire an image of at least two electrodes of the workpiece facing the at least two minute openings through the at least two minute openings of the ball mounting mask. It is preferable. By doing in this way, the 2nd position for aligning a ball mounting mask and a work more accurately can be acquired.

  The mounting device preferably further includes a dispenser moving mechanism for moving the ball dispenser. The second camera is preferably movable by a dispenser moving mechanism. By doing so, a mechanism for moving the second camera can be omitted. In addition, when the ball dispenser is moved, the ball dispenser does not interfere with the second camera.

Further, this mounting apparatus has a flux coating mask holder (mask plate) for holding a flux coating mask (mask plate) having a plurality of minute openings for coating flux on a workpiece at a third position with respect to the base. Mask holding means) and at least one of the workpieces facing the at least one minute opening through the at least one minute opening of the flux application mask from above the flux application mask held by the flux application mask holder. For applying a flux from a third camera capable of acquiring an image of one electrode and a flux application mask held by a flux application mask holder through a plurality of minute openings of the flux application mask. It is preferable to further have a flux coating head. The control unit preferably further includes the following functions.
(A3) The workpiece is moved under the flux coating mask held by the flux coating mask holder so that the workpiece reference position is determined by the third position by the transport stage, and the third A fourth position relative to the base of the workpiece reference position when at least one minute opening of the flux coating mask and at least one electrode facing the at least one minute opening are aligned via the camera. Obtain and record in memory (third function).
(A4) The workpiece is moved under the flux coating mask held by the flux coating mask holder so that the workpiece reference position becomes the fourth position by the transfer stage, and the workpiece is moved by the flux coating head. Applying flux to a plurality of electrodes through a plurality of minute openings of a flux application mask (fourth function).

  According to this mounting apparatus, it is possible to perform a series of operations by applying flux to the electrode of the workpiece and mounting the ball thereon.

  Further, according to this mounting apparatus, the workpiece is placed under the flux coating mask held by the flux coating mask holder so that the workpiece reference position is determined by the third position by the transfer stage. By moving it, the position of the flux coating mask and the workpiece can be adjusted. That is, the third position of the flux coating mask with respect to the base and the position of the workpiece relative to the transfer stage (work reference) recorded in the memory by detecting the reference mark of the workpiece mounted on the transfer stage with the third camera. Position) can be used to align the flux coating mask with the workpiece.

  In addition, according to this mounting apparatus, the accuracy of alignment between the flux application mask and the workpiece can be improved in the same manner as the positional accuracy between the ball mounting mask and the workpiece. That is, when the workpiece is moved so that the workpiece reference position is determined by the third position, the position of the minute opening of the flux coating mask and the position of the electrode of the workpiece has a diameter of several hundred μm or more. Even if there is a deviation in the order of the size of the fine opening suitable for applying the flux so as to correspond to the following fine balls, the third camera passes it through at least one fine opening of the flux application mask. By acquiring an image of at least one electrode facing each other, the position of the workpiece can be finely adjusted. In this mounting apparatus, the position of the workpiece is finely adjusted by moving the workpiece so that at least one minute opening of the flux coating mask and at least one electrode facing the same coincide with each other. The fourth position relative to the base of the workpiece reference position can be obtained and recorded in the memory. The fourth position is positional information including a deviation between a state in which the workpiece and the flux coating mask are aligned by the respective reference marks and a state in which the minute opening matches the electrode, that is, an offset value. .

  Furthermore, according to this mounting apparatus, the workpiece is moved by the transfer stage so that the workpiece reference position becomes the fourth position under the flux coating mask held by the flux coating mask holder. As a result, the flux can be accurately applied to the plurality of electrodes of the workpiece by the coating head through the plurality of minute openings of the flux coating mask while being aligned with higher accuracy than the alignment using the reference marks. can do.

  As described above, according to the mounting apparatus, the flux is applied to the workpiece by acquiring an image of at least one electrode facing the third application through the at least one minute opening of the flux application mask by the third camera. The state can be simulated and the position of the workpiece can be finely adjusted. Therefore, the flux coating mask and the workpiece are accurately aligned without actually applying the flux to the workpiece via the flux coating mask, and the flux is not displaced or is in a small state on the workpiece electrode. It can be applied satisfactorily.

  In this case, it is preferable that the mounting apparatus further includes a head moving mechanism that moves the flux application head. The third camera is preferably movable by a head moving mechanism. By doing so, a mechanism for moving the third camera can be omitted. Moreover, when the flux application head is moved, the flux application head does not interfere with the third camera.

  FIG. 1 shows a mounting apparatus according to an embodiment of the present invention. The mounting apparatus 1 is an apparatus for mounting a conductive ball Be on a plurality of electrodes 90a provided on a work 90, and is also called a ball mounter, a ball mounting apparatus, or the like. The mounting apparatus 1 of this example has a nominal 12-inch circular semiconductor wafer (hereinafter simply referred to as a wafer) provided with a plurality of land-shaped (convex) electrodes (hereinafter referred to as lands, see FIG. 3) 90a on the surface. A ball is mounted as a workpiece (object, workpiece, substrate, mounted object) 90. The upper surfaces of the lands 90a are each circular. As shown in FIG. 2, the wafer 90 is provided with two alignment marks 90b and 90c as reference marks. The two alignment marks 90b and 90c are provided outside the ball mounting area S.

  The work is not limited to this. For example, an electronic circuit board (multilayer board) can be used as the workpiece. A resist layer is formed on the multilayer substrate. The resist layer has a portion corresponding to the electrode removed by etching or the like. In such a workpiece, the electrode portion may be concave.

  The conductive balls Be mounted on the plurality of lands 90a of the wafer 90 function to obtain electrical connection, and the diameter thereof is, for example, 1 mm or less, specifically about 10 to 500 μm. This is also called a micro ball. The conductive balls Be include solder balls (including silver (Ag), copper (Cu), and the like, a ball mainly composed of tin (Sn)), a metal ball such as gold or silver, and a ceramic ball. This includes balls or plastic balls that have been subjected to a treatment such as conductive plating. In this example, a solder ball having a diameter of about 90 μm is used as the conductive ball.

  The mounting apparatus 1 includes a chassis (base) 2 serving as a positioning reference, and an XYZθ moving stage (conveyance) that conveys the wafer 90 to a predetermined position with respect to the base 2 in a state where the warpage of the wafer 90 is corrected by a method such as vacuum suction. Stage) 3, loader / unloader device 4 for loading (supplying) and unloading (accommodating) wafer 90, aligner 5 for performing rough alignment of wafer 90, and wafer transfer device (wafer transfer robot) 7 and the like. The wafer transfer robot 7 transfers the wafer 90 from the loader / unloader device 4 to above the aligner 5, transfers the wafer 90 from the aligner 5 to the transfer stage 3, and further transfers the wafer 90 from the transfer stage 3 to the loader / unloader device 4.

  The mounting device 1 further includes a correction device 6 for correcting warpage of the wafer 90 and a flux application device (flux printing device) for applying a flux to the lands 90a of the wafer 90 via the flux application mask 11. ) 10, two first cameras 51 a and 51 b for detecting alignment marks (reference marks) 90 b and 90 c of the wafer 90, and a plurality of lands 90 a of the wafer 90 through the ball mounting mask 21. And a ball filling device 20 for mounting (arranging) the functional balls Be, and the transfer stage 3 moves between these devices with the wafer 90 mounted thereon. Furthermore, the mounting device 1 can transmit and receive electrical or control information to and from the control unit 30 (see FIG. 9) for controlling each device of the mounting device 1 including the destination of the transfer stage 3. And a memory (see FIG. 9) 40 connected to the.

  In the mounting apparatus 1, the wafer 90 roughly aligned (prealigned) by the aligner 5 is mounted on the transfer stage 3 by the wafer transfer robot 7. The conveyance stage 3 moves between the correction device 6, the flux coating device 10, the cameras 51a and 51b, and the ball filling device 20, and these are arranged side by side in the X direction (left and right direction in FIG. 1). The transfer stage 3 includes an X-axis table, a Y-axis table, a Z-axis table, and a θ table. Therefore, with the transfer stage 3, the wafer 90 is held on the upper surface (XY plane in this example) of the transfer stage 3, and the correction device 6, the flux applying device 10, the cameras 51a and 51b, and the ball filling The position of the wafer 90 can be adjusted in the X-axis direction, Y-axis direction, Z-axis direction, and θ direction. Note that the method of holding the wafer 90 on the transfer stage 3 is not limited to the vacuum suction, and may be an electrostatic chuck or a combination thereof.

  Next, the flux application device 10 and the ball filling device 20 will be described in detail.

  FIG. 3 is a view showing a part of the flux applying apparatus 10 and shows a state in which the flux F is applied to the flux applying mask 11. FIG. 4 shows a state in which the flux F is applied onto the land 90 a of the wafer 90. FIG. 5 shows a state in which the application of the flux F to the land 90a of the wafer 90 is completed.

  The flux applying apparatus 10 is a screen printing apparatus for applying a material (flux F) for bonding the wafer 90 and the conductive balls Be onto a plurality of lands 90 a on the upper surface of the wafer 90. belongs to. As shown in FIG. 1 and FIGS. 3 to 5, the flux application apparatus 10 includes a flux application mask holder 12 that holds a flux application mask 11, a flux application head (squeegee) 13, and a flux application head. And a head moving mechanism 14 for moving 13.

  As shown in FIGS. 3 to 5, the flux application mask 11 includes a plurality of minute openings (apertures, micro apertures) 11 a for applying the flux F to the wafer 90. The pattern of the plurality of micro openings 11 a of the flux application mask 11 corresponds to the pattern of the plurality of lands 90 a of the wafer 90, and the diameter of each micro opening 11 a of the flux application mask 11 is set to each land 90 a of the wafer 90. The diameter of the upper surface of each land 90a is slightly larger than that of the upper surface of each land 90a.

  Further, as shown in FIG. 1, the flux coating mask 11 is provided with two alignment marks 11b and 11c as reference marks. The two alignment marks 11b and 11c are provided outside the flux application region corresponding to the ball mounting region S of the wafer 90. The two alignment marks 11b and 11c are arranged side by side in the Y direction (vertical direction in FIG. 1). The flux application mask 11 is set on a flux application mask holder 12. In this state, alignment marks 11 b and 11 c of the mask 11 are observed by a camera 53 described later, and the position is recorded as a reference position (third position) of the flux coating mask 11 with respect to the base 2. That is, the flux application mask 11 is held at the third position with respect to the base 2 by the flux application mask holder 12.

  The flux application head 13 is for applying the flux F from above the flux application mask 11 held by the flux application mask holder 12 through a plurality of minute openings 11a. As shown in FIG. 1, the head moving mechanism 14 includes a pair of Y-axis tables 14a and 14b. The flux application head 13 extends along the X direction, and is provided so as to straddle the pair of Y-axis tables 14a and 14b. Therefore, the head moving mechanism 14 can move the flux application head 13 along the Y direction.

  A camera 53 is attached to the coating head 13, and when the coating head 13 is moved by the head moving mechanism 14, the camera 53 is also moved. That is, the camera 53 can be moved by the head moving mechanism 14. Therefore, the camera 53 can be moved to an arbitrary position in the Y-axis direction on the coating mask 11 by the head moving mechanism 14. The head moving mechanism 14 is connected to the control unit 30 so as to be able to transmit and receive electrical or control information. The movement of the head moving mechanism 14, that is, the movement of the flux application head 13 is controlled by the control unit 30. . Further, the image from the camera 53 is analyzed by the control unit 30, the third position is determined by the alignment marks 11 b and 11 c, and can be stored in the memory 40.

  The flux applying apparatus 10 applies the flux F onto the plurality of lands 90a of the wafer 90 as follows. First, as shown in FIG. 3, flux F is applied on the flux application mask 11. Then, as shown in FIG. 4, the flux F is applied onto the land 90 a of the wafer 90 by pressing the flux application mask 11 against the wafer 90 by the flux application head 13. The flux application head 13 moves from the plus side to the minus side along the Y direction while pushing down the flux application mask 11. As a result, a part of the flux application mask 11 pushed down by the flux application head 13 comes into contact with the land 90a of the wafer 90, and the flux F passes through the plurality of minute openings 11a of the flux application mask 11. The wafer 90 is sequentially coated on the plurality of lands 90a. By moving the flux application head 13 along the Y direction from one end to the other end of the flux application region, as shown in FIG. 5, the plurality of minute openings 11a of the flux application mask 11 are formed. The flux F is applied on the position based on the pattern, that is, on the plurality of lands 90 a of the wafer 90.

  FIG. 6 shows a ball mounting mask 21. A plurality of micro openings each having a diameter of about 90 to 100 μm for arranging the micro balls Be having a diameter of 90 μm are arranged in the ball filling region S1. It is provided in a predetermined pattern for placement. FIG. 7 shows a part of the ball filling device 20. FIG. 8 shows an enlarged part of FIG.

  The ball filling device 20 fills the minute openings provided in the ball filling region S1 of the ball mounting mask 21 with the balls Be, thereby allowing the plurality of lands 90a of the wafer 90 to be electrically conductive via the flux F. This is for mounting (arranging) the balls Be. The ball filling device 20 includes a ball mounting mask holder 22 that holds a ball mounting mask 21, two ball dispensers 23a and 23b, a support member 24 that supports the two ball dispensers 23a and 23b, and a support member 24. And a dispenser moving mechanism 25 for moving the two ball dispensers 23a and 23b in the X and Y directions.

  As shown in FIGS. 7 and 8, the ball mounting mask 21 has a plurality of minute openings (apertures) for mounting the conductive balls Be on the plurality of lands 90a of the wafer 90 via the flux F. Microaperture) 21a. The position of the conductive ball Be is determined by filling each of the plurality of minute openings 21a of the ball mounting mask 21 with the conductive ball Be. Accordingly, the conductive balls Be can be mounted on the plurality of lands 90 a of the wafer 90 through the ball mounting mask 21. The pattern of the plurality of micro openings 21 a of the ball mounting mask 21 corresponds to the pattern of the plurality of lands 90 a of the wafer 90, and the diameter of each micro opening 21 a of the ball mounting mask 21 is set to each land 90 a of the wafer 90. It is slightly larger than the diameter of the upper surface.

  As shown in FIGS. 1 and 6, the ball mounting mask 21 is provided with two alignment marks 21b and 21c as reference marks. The two alignment marks 21b and 21c are provided outside the ball filling area S1 facing the ball mounting area S of the wafer 90. The two alignment marks 21b and 21c are arranged side by side in the X direction (left and right direction in FIGS. 1 and 6). The two alignment marks 21b and 21c may be arranged side by side in the Y direction (the vertical direction in FIGS. 1 and 6) or may be arranged obliquely in the XY direction.

  The ball mounting mask 21 is fixed to the mask frame 21d in a state where a certain amount of tension is applied. The ball mounting mask 21 is set on the ball mounting mask holder 22 through the mask frame 21d. In this state, alignment marks 21 b and 21 c of the mask 21 are observed by a camera 52 described later, and the position is recorded as a reference position (first position P 1) of the ball mounting mask 21 with respect to the base 2. That is, the ball mounting mask 21 is held at the first position P 1 with respect to the base 2 by the ball mounting mask holder 22.

  The two ball dispensers 23 a and 23 b form two moving areas A 1 and A 2 on the surface of the ball mounting mask 21. For this reason, two independent groups Bg of conductive balls Be are held at different locations A1 and A2 on the surface of the ball mounting mask 21 held by the ball mounting mask holder 22, respectively. Then, the two ball dispensers 23a and 23b move the moving areas A1 and A2 independently or in conjunction with each other, from above the ball mounting mask 21 held by the ball mounting mask holder 22, into a plurality of minute openings 21a, respectively. Fill the balls Be.

  Specifically, the two ball dispensers 23 a and 23 b are supported by the support member 24 in a state where a predetermined distance is maintained that is approximately equal to the radius of the wafer 90. The dispenser moving mechanism 25 includes an X-axis table 26 and a pair of Y-axis tables 27a and 27b. The X-axis table 26 is provided so as to straddle the pair of Y-axis tables 27a and 27b. The two ball dispensers 23 a and 23 b are supported by the X-axis table 26 via the support member 24. Accordingly, the dispenser moving mechanism 25 keeps the two ball dispensers 23 a and 23 b on the upper surface of the ball mounting mask 21, that is, on the XY plane in a state where a predetermined distance equivalent to the radius of the wafer 90 is maintained. It can be moved to any position in the two-dimensional direction.

  The camera 52 is mounted on the ball dispenser 23a so as to move in conjunction with the ball dispenser 23a. That is, the camera 52 can be moved by the dispenser moving mechanism 25. Accordingly, by moving the ball dispenser 23 a by the dispenser moving mechanism 25, the camera 52 moves to an arbitrary position (an arbitrary position in the two-dimensional direction) on the XY plane above the ball mounting mask 21. .

  The dispenser moving mechanism 25 is connected to the control unit 30 so as to be able to transmit and receive electrical or control information. The movement of the dispenser moving mechanism 25, that is, the movement of the ball dispensers 23 a and 23 b is controlled by the control unit 30. . Further, the image by the camera 52 is analyzed by the control unit 30, and the first position P 1 is determined by the alignment marks 21 b and 21 c and can be stored in the memory 40.

  As shown in FIG. 7, the two ball dispensers 23a and 23b have substantially the same configuration. Each of the ball dispensers 23a and 23b includes a disk-shaped squeegee support 28a and a squeegee 28b protruding from the lower surface of the squeegee support 28a toward the upper surface of the ball mounting mask 21. The centers of the squeegee supports 28a are connected to shafts 28c extending in the direction perpendicular to the ball mounting mask 21, respectively.

  The squeegee 28b only needs to be in contact with the upper surface of the ball mounting mask 21 relatively softly and can sweep up the conductive balls Be on the ball mounting mask 21. Preferably, the squeegee 28b is provided with elasticity that does not scrape the conductive ball Be once inserted into the minute opening 21a of the ball mounting mask 21. As an example of such a squeegee 28b, a wire bent so as to be in contact with the upper surface of the ball mounting mask 21, an elastic member such as a rubber plate or sponge shaped so as to be in contact with the upper surface of the ball mounting mask 21, a ball A myriad of wires that extend to the extent that they are in contact with the upper surface of the mounting mask 21 can be cited.

  Each of the ball dispensers 23a and 23b is rotationally driven around a shaft 28c by a motor (not shown). As the ball dispensers 23a and 23b rotate, the conductive balls Be are collected by the ball dispensers 23a and 23b from the area around the moving areas A1 and A2 into the moving areas A1 and A2 so as not to escape. . Therefore, the collective balls Bg of the plurality of conductive balls Be are held in the circular moving areas A1 and A2 formed by the ball dispensers 23a and 23b, respectively.

  Further, the two ball dispensers 23a and 23b draw arbitrary trajectories on the ball mounting mask 21 while rotating around the shaft 28c while keeping a predetermined distance by the dispenser moving mechanism 25. To move. Accordingly, the group Bg of conductive balls Be held by the ball dispensers 23a and 23b also moves. Then, the conductive balls Be held in the circular moving areas A 1 and A 2 are sequentially filled into the micro openings 21 a of the ball mounting mask 21 and mounted on the lands 90 a of the wafer 90.

  The conductive balls Be held in the moving areas A1 and A2 are consumed by filling the minute openings 21a. Therefore, in the ball filling device 20 of this example, the conductive ball Be is thrown into the moving areas A1 and A2 through the shaft 28c from the ball replenishing device (not shown) based on the amount of the ball Be consumed. It has come to be. In this example, the ball filling device 20 includes two ball dispensers 23a and 23b. However, the ball filling device 20 may include one ball dispenser or three or more ball dispensers. Good. Further, the shape of the ball dispenser is not limited to the above, and any shape may be used as long as the plurality of minute openings 21a of the ball mounting mask 21 can be filled with the balls Be.

  Returning to FIG. 1, the mounting apparatus 1 includes two first cameras 51 a and 51 b that can record in the memory 40 with the position of the wafer 90 relative to the transfer stage 3 as the wafer reference position Pw. In addition, the mounting apparatus 1 can record the first position P1 of the ball mounting mask 21 with respect to the base 2 and can display an image of the land 90a of the wafer 90 facing through the minute opening 21a of the ball mounting mask 21. An acquirable second camera 52 is provided. Furthermore, the mounting apparatus 1 can record the third position P3 of the flux application mask 11 with respect to the base 2, and can also display an image of the land 90a of the wafer 90 facing through the minute opening 11a of the flux application mask 11. And a third camera 53 that can be acquired.

  The two first cameras 51 a and 51 b are fixed between the flux applying device 10 and the ball filling device 20. The two first cameras (fixed cameras) 51a and 51b are arranged side by side along the Y direction. The two first cameras 51a and 51b are arranged as far apart as the distance between the two alignment marks 90b and 90c of the wafer 90. The two first cameras 51a and 51b respectively detect the two alignment marks 90b and 90c of the wafer 90 mounted on the transfer stage 3 from above.

  The control unit 30 moves the transfer stage 3 in the X, Y, and / or θ directions so that the two alignment marks 90b and 90c are detected by the cameras 51a and 51b, respectively, so that the wafer 90 is mounted on the transfer stage 3. To understand in detail. That is, the control unit 30 detects the two alignment marks 90b and 90c with the cameras 51a and 51b, and records the position of the wafer 90 relative to the transfer stage 3 in the memory 40 as the wafer reference position Pw. The wafer reference position Pw includes an offset amount from the position of the wafer 90 roughly aligned with the transfer stage 3 by the aligner 5, an offset amount from the center coordinates and reference angle of the transfer stage 3, and the like. An example of the wafer reference position Pw is the XY coordinates of the center of the wafer 90 and the inclination θ (inclination θ of the wafer 90) from the reference line of the transfer stage 3, and the result calculated by the control unit 30 is used as position information. Stored in the memory 40.

  The second camera 52 moves in association with the dispenser 23 a included in the ball filling device 20. Therefore, the second camera 52 is moved to an arbitrary position on the XY plane (an arbitrary position in the two-dimensional direction) above the ball mounting mask 21 by the dispenser moving mechanism 25. The second camera (moving camera) 52 sequentially detects the two alignment marks 21b and 21c of the ball mounting mask 21 from above while moving along the XY direction, and the ball mounting mask 21 with respect to the base 2 is detected. Is recorded in the memory 40. An example of the first position P1 is position information including the XY coordinates of the center of the mask 21 or the ball filling area S1 with respect to the base 2 and the inclination θ.

  Further, the second camera 52 moves to the ball filling area S1. Therefore, the second camera 52 can image the minute opening 21 a of the ball mounting mask 21 from above the ball mounting mask 21 held by the ball mounting mask holder 22. Furthermore, an image of the land 90a of the wafer 90 facing the minute opening 21a can be acquired by the camera 52 through the minute opening 21a. In one example, the control unit 30 acquires images of the plurality of minute openings 21a on the trajectory while moving the second camera 52 along the XY direction by the dispenser moving mechanism 25. For example, images of the three lands 90a of the wafer 90 that are respectively opposed to the three minute openings 21a are sequentially acquired via predetermined or arbitrary three minute openings 21a of the ball mounting mask 21.

  The third camera 53 is mounted on the coating head 13 provided in the flux coating apparatus 10. Therefore, the third camera 53 is moved in the Y direction above the flux application mask 11 by the head moving mechanism 14. The third camera (moving camera) 53 sequentially detects the two alignment marks 11b and 11c of the flux coating mask 11 provided along the Y direction from the upper side while moving along the Y direction. The third position P3 of the flux application mask 11 is recorded in the memory 40. The two alignment marks 11b and 11c of the flux application mask 11 are provided so as to fall within the imaging range of the third camera 53 when the third camera 53 moves along the Y direction. An example of the third position P3 is position information including the XY coordinates of the center of the mask 11 with respect to the base 2 and the inclination θ.

  Further, the third camera 53 moves to an area facing the ball mounting area S of the wafer 90. Therefore, the third camera 53 can image the minute opening 11a of the flux application mask 11 from above the flux application mask 11 held by the flux application mask holder 12. Furthermore, the camera 53 can acquire an image of the land 90a of the wafer 90 facing the minute opening 11a through the minute opening 11a. In one example, the control unit 30 moves the third camera 53 along the Y direction by the head moving mechanism 14, and images the plurality of minute openings 11a of the flux coating mask 11 on the trajectory. get. For example, images of the three lands 90a of the wafer 90 that are respectively opposed to the three micro openings 11a are sequentially acquired via the predetermined three micro openings 11a. These three measurement points are located within a range in which an image of the land 90a can be acquired by the third camera 53 when the third camera 53 moves along the Y direction.

  FIG. 9 shows a schematic configuration of the control system of the mounting apparatus 1. The mounting apparatus 1 includes a control section 60. The control section 60 includes a control unit 30 and a memory 40. The control unit 30 and the memory 40 are connected electrically or in a state where control information can be transmitted and received. Although not shown, the control section 60 further manually controls each device of the mounting device 1 including a display indicating the operation state of the mounting device 1, a display indicating an image captured by each camera described above, and the transfer stage 3. An operation panel that can be controlled may be included.

  Many of the control units 30 are configured using a computer or a microcomputer. A control program is recorded in the memory 40. The control program can be provided by being recorded on an appropriate recording medium such as a ROM. The on-board device 1 can be controlled via a computer network such as a LAN by providing a LAN interface in the control section 60. It is also possible to provide a control program from a server on the network. The memory 40 of this example includes a program storage area 41 and an image and position information recording area 42. In the recording area 42, images and position information acquired by the first, second, and third cameras 51a, 51b, 52, and 53 are recorded.

  The control unit 30 includes a flux application device 10 including a head moving mechanism 14, a ball filling device 20 including a dispenser moving mechanism 25, first cameras 51a and 51b, a second camera 52, a third camera 53, and a transfer stage. 3, is connected to an aligner 5 or the like in a state where electrical or control information can be transmitted and received, and controls these operations.

  As shown in FIG. 9, the control unit 30 has the following six functions 31 to 36. First, the mask position acquisition function 31 detects the alignment marks 21b and 21c of the ball mounting mask 21 held by the ball mounting mask holder 22 by the second camera 52, and mounts the ball on the base 2 in the memory 40. The first position P1 of the mask 21 for recording is recorded. Further, the third camera 53 detects the alignment marks 11 b and 11 c of the flux application mask 11 held by the flux application mask holder 12, and the third mark of the flux application mask 11 with respect to the base 2 is detected in the memory 40. Record position P3.

  The wafer position acquisition function 32 detects the alignment marks 90b and 90c of the wafer 90 mounted on the transfer stage 3 by the first cameras 51a and 51b, and stores the position of the wafer 90 relative to the transfer stage 3 in the memory 40. Recorded as the wafer reference position Pw.

  An application mask and wafer alignment information acquisition function (third function) 33 is such that the wafer reference position Pw is set below the flux application mask 11 held by the flux application mask holder 12 by the transfer stage 3. The wafer 90 is moved so as to be a position determined by the third position P3. Further, the three minute openings 11a of the flux application mask 11 and the three lands 90a respectively facing the three minute openings 11a are aligned via the third camera 53. This alignment process may be performed manually by the operator while viewing the image of the third camera 53. A fourth position P4 with respect to the base 2 of the wafer reference position Pw at the time of alignment is acquired and recorded in the memory 40.

  An example of the fourth position P4 is the X coordinate of the center of the wafer 90 relative to the base 2, the Y coordinate of the center of the wafer 90 relative to the base 2, and the inclination θ (the notch direction θ of the wafer 90). The fourth position P4 is a position aligned by the third position P3 obtained from the alignment marks 11b and 11c of the mask 11 and the wafer reference position Pw obtained from the alignment marks 90b and 90c of the wafer 90. The offset amount from is included.

  The flux application function (fourth function) 34 is arranged so that the wafer reference position Pw becomes the fourth position P4 by the transfer stage 3 below the flux application mask 11 held by the flux application mask holder 12. Next, the wafer 90 is moved. By moving the transfer stage 3 and setting the wafer reference position Pw of the wafer 90 relative to the transfer stage 3, that is, the wafer 90 on the transfer stage, to the fourth position P 4 with respect to the base 2, the third function 33 is performed. The obtained state can be reproduced. Assuming that the drift phenomenon does not occur in the flux application mask 11, the other reference positions Pw of the other wafers 90 are set to the fourth position with the respective wafers 90 placed on the transfer stage 3. By setting to P4, the state obtained by the third function 33 can be reproduced. Therefore, the flux F is applied to the plurality of lands 90a of the wafer 90 by the coating head 13 through the plurality of minute openings 11a of the flux coating mask 11, respectively, so that the flux can be applied with a predetermined accuracy on the wafer 90. Can be applied to the position.

  The mounting mask and wafer alignment information acquisition function (first function) 35 is such that the wafer reference position Pw is set under the ball mounting mask 21 held by the ball mounting mask holder 22 by the transfer stage 3. The wafer 90 is moved so as to be a position determined by the first position P1. Further, through the second camera 52, the three minute openings 21a of the ball mounting mask 21 and the three lands 90a respectively opposed to the three minute openings 11a are aligned. This alignment process may be performed manually by the operator while viewing the image of the second camera 52. The second position P2 with respect to the base 2 of the wafer reference position Pw when the alignment is performed is acquired and recorded in the memory 40.

  An example of the second position P2 is the X coordinate of the center of the wafer 90 relative to the base 2, the Y coordinate of the center of the wafer 90 relative to the base 2, and the inclination θ (the notch direction θ of the wafer 90). The second position P2 is a position aligned by the first position P1 obtained from the alignment marks 21b and 21c of the mask 21 and the wafer reference position Pw obtained from the alignment marks 90b and 90c of the wafer 90. The offset amount from is included.

  The ball mounting function (second function) 36 is such that the wafer reference position Pw is set to the second position P2 by the transfer stage 3 below the ball mounting mask 21 held by the ball mounting mask holder 22. Next, the wafer 90 is moved. By setting the wafer reference position Pw of the wafer 90 relative to the transfer stage 3 to the second position P2, the state obtained by the first function 35 can be reproduced. Assuming that the drift phenomenon does not occur in the mask 21, by moving the transfer stage 3 so that the wafer reference position Pw on the transfer stage becomes the second position P2 also for the other wafers 90, The state obtained by the first function 35 can be reproduced. Therefore, the balls Be can be mounted on the plurality of lands 90a of the wafer 90 with high accuracy by filling the balls Be into the plurality of minute openings 21a of the ball mounting mask 21 by the ball dispensers 23a and 23b.

  FIG. 10 is a flowchart illustrating an example of a control method for the mounting apparatus 1. The control unit 30 controls the mounting device 1 as follows. First, in step 101, it is confirmed that the flux application mask 11 has been set in the flux application mask holder 12. Further, it is confirmed that the ball mounting mask 21 has been set in the ball mounting mask holder 22. Setting the masks 11 and 21 in the respective mask holders is usually done artificially. A plurality of types of masks may be automatically replaceable depending on the type of wafer. When step 101 is confirmed, the control unit 30 measures and records the position (third position P3) of the flux application mask 11 by the mask position acquisition function 31 in step 102. Further, the position (first position P1) of the ball mounting mask 21 is measured and recorded. Either the measurement / recording of the third position P3 with respect to the base 2 of the flux coating mask 11 or the measurement / recording of the first position P1 with respect to the base 2 of the ball mounting mask 21 may be performed first. It can also be done in parallel.

  Next, in step 103, the wafer 90 is loaded from the loader / unloader device 4, transferred by the wafer transfer device (wafer transfer robot) 7, and set above the aligner 5. In step 104, coarse alignment is performed by the aligner 5 using the orientation flat or notch of the wafer 90. This rough alignment allows the images of the first cameras 51a and 51b to be acquired when the two first alignment marks 90b and 90c of the wafer 90 are detected later by the two first cameras (fixed cameras) 51a and 51b. This is to prevent the alignment marks 90b and 90c of the wafer 90 from being removed from the region. In the aligner 5, the wafer 90 is rotated, and the notch end of the wafer 90 is detected by an optical sensor. Then, the angle (rotation angle, notch direction) θ of the wafer 90 with respect to the reference position and the XY coordinates of the center of the wafer 90 are calculated, and the wafer 90 is moved to the correction position. For example, the accuracy is about ± 0.1 ° for θ, and about ± 0.2 mm for each of the X and Y coordinates.

  In step 105, the wafer 90 is transferred by the wafer transfer device 7 and set on the transfer stage 3. In step 106, the transfer stage 3 is moved to below the first cameras 51a and 51b, and the wafer position acquisition function 32 measures and records the position of the wafer 90 (wafer reference position Pw).

  In step 107, it is determined whether or not the alignment between the wafer 90 and the flux application mask 11 and the alignment between the wafer 90 and the ball mounting mask 21 are necessary. For example, immediately after the masks 11 and 21 are set in the mask holders 12 and 22, alignment is required before the ball Be is mounted on the wafer 90. Further, after the masks 11 and 21 are set on the mask holders 12 and 22, the positions of the masks 11 and 21 are difficult to stabilize for a certain period of time (for example, about 6 hours). That is, the masks 11 and 21 are once aligned with the wafer 90, and a deviation (offset value, offset amount, correction value, fine adjustment value) between the masks 11 and 21 and the wafer 90 is acquired as follows. However, the offset value changes (drifts) with time for a certain amount of time. The drift value is, for example, about 20 to 50 μm. The cause of the drift may be a shift of the mask position accompanying the temperature change of the masks 11 and 21, but it is not certain. The drift value becomes smaller as the operating time of the apparatus elapses. Therefore, until the positions of the masks 11 and 21 are stabilized, alignment may be required every time the ball Be is mounted on one or several wafers 90.

  In step 107, the operator may determine that the alignment between the wafer 90 and the flux application mask 11 and the alignment between the wafer 90 and the ball mounting mask 21 are necessary. The initial setting may be performed based on conditions such as a schedule and an elapsed time. If alignment is required, the alignment information acquisition functions 33 and 35 perform alignment processing in step 108 and subsequent steps. This process includes an initial alignment process (step 108, step 110) and a fine adjustment process (step 109, step 111), as will be described below.

  First, in step 108, the control unit 30 moves the wafer 90 to the flux coating apparatus 10 by the alignment information acquisition function 33 between the coating mask and the wafer. Specifically, the wafer 90 is placed under the flux application mask 11 held by the flux application mask holder 12 so that the wafer reference position Pw is determined by the third position P3 by the transfer stage 3. Move. For example, by moving the transfer stage 3, the center XY coordinates and inclination θ included in the wafer reference position Pw with respect to the base 2 are changed to the center XY coordinates and inclination θ included in the third position P 3 of the flux coating mask 11. (Initial alignment).

  As described above, this initial alignment is alignment based on the alignment mark. When the ball diameter is reduced, the alignment accuracy is not sufficient, and drift (mask position deviation that occurs over time) occurs. In some cases, the positions of the plurality of minute openings 11 a of the flux coating mask 11 and the positions of the plurality of lands 90 a of the wafer 90 may be misaligned.

  For this reason, in step 109, the third camera 53 obtains an image of the land 90a of the corresponding wafer 90 through the minute opening 11a of the flux application mask 11, thereby finely adjusting the initial alignment. I do. That is, the image of the minute opening 11a of the flux coating mask 11 and the image of the land 90a of the wafer 90 corresponding to the image are matched (for example, the image of the land 90a fits in the minute opening 11a). And the 4th position P4 with respect to the base 2 of the wafer reference position Pw at that time is acquired.

  Subsequently, the control unit 30 acquires the first position P1 by the alignment information acquisition function 35 between the mounting mask and the wafer. Acquisition of alignment information between the mounting mask and the wafer may be performed prior to acquisition of alignment information between the coating mask and the wafer described above. First, in step 110, the wafer 90 is moved to the ball filling device 20. For example, by moving the transfer stage 3, the XY coordinates and inclination θ of the center included in the wafer reference position Pw with respect to the base 2, and the XY coordinates and inclination θ of the center included in the first position P 1 of the ball mounting mask 21. (Initial alignment).

  Also in the ball mounting mask 21, this initial alignment is alignment based on the alignment mark as described above. When the ball diameter is reduced, the alignment accuracy is not sufficient, and due to drift or the like, In some cases, the positions of the plurality of minute openings 21 a of the ball mounting mask 21 are shifted from the positions of the plurality of lands 90 a of the wafer 90.

  For this reason, in step 111, the image of the land 90a of the corresponding wafer 90 is acquired by the second camera 52 through the minute opening 21a of the ball mounting mask 21, thereby finely adjusting the initial alignment. I do. That is, the image of the minute opening 21a of the ball mounting mask 21 and the image of the land 90a of the wafer 90 corresponding thereto are matched (for example, the image of the land 90a is accommodated in the minute opening 21a). And the 2nd position P2 with respect to the base 2 of the wafer reference position Pw at that time is acquired.

  Thereafter, in step 112, the control unit 30 sets the wafer 90 in the flux applying apparatus 10 by the flux applying function 34 and applies the flux to the wafer 90. Specifically, the wafer 90 is moved under the flux coating mask 11 held by the flux coating mask holder 12 by the transfer stage 3 so that the wafer reference position Pw becomes the fourth position P4. In step 113, the flux F is applied to the plurality of lands 90 a of the wafer 90 by the coating head 13 through the plurality of micro openings 11 a of the flux coating mask 11.

  Thereafter, in step 114, the control unit 30 sets the wafer 90 on the ball filling device 20 by the ball mounting function 36 and mounts the ball Be on the wafer 90. Specifically, the wafer 90 is moved under the ball mounting mask 21 held by the ball mounting mask holder 22 by the transfer stage 3 so that the wafer reference position Pw becomes the second position P2. In step 115, the ball Be is filled into the plurality of minute openings 21 a of the ball mounting mask 21 by the ball dispensers 23 a and 23 b, and the ball Be is mounted on the plurality of lands 90 a of the wafer 90 via the flux F. .

  In step 116, the wafer 90 is unloaded to the loader / unloader device 4. In step 117, when the conductive ball Be is subsequently mounted on the wafer 90 (when the unprocessed wafer 90 remains), the process returns to step 103 to process the next wafer 90. If the conductive ball Be is not mounted on the wafer 90 in step 117 (no unprocessed wafer 90 remains), the job is terminated.

  After the states of the respective masks 11 and 21 are stabilized, the second position P2 and the fourth position P4 acquired before are used even if the alignment information is not acquired every time the wafer 90 that is the workpiece changes. Thus, the masks 11 and 21 and the wafer 90 can be aligned with high accuracy. In such a case, it is determined in step 107 that the alignment between the wafer 90 and the flux application mask 11 and the alignment between the wafer 90 and the ball mounting mask 21 are unnecessary, and the alignment process (step 108). To step 111) are omitted.

  As an example of fine adjustment of the mask and the wafer, step 111 relating to the ball mounting mask 21 will be described in more detail. Note that step 109 regarding the flux application mask 11 can be performed in the same manner as step 111. FIG. 11 shows an example of the control method in step 109 and step 111. FIG. 12 shows points for acquiring an image in step 111.

  In this example, the images of the land 90a corresponding to each of the three points A, B, and C shown in FIG. 12 are acquired through the minute openings 21a at the points A, B, and C. Then, the position of the wafer 90 with respect to the mask 21 is finely adjusted. These three measurement points A, B, and C are provided in a line along the Y direction.

  Point B indicates the approximate center of the ball filling area (transfer area) S1. Point A indicates a position that is + y1 cm away from point B in the Y direction. Point C indicates a position that is -y1 cm away from point B in the Y direction. Note that the points A and C are preferably separated from each other. When a conductive ball having a diameter of 90 μm is mounted on a 12-inch wafer, an example of the value of y1 is 5 cm. That is, in this example, the point A and the point C are separated by 10 cm.

  First, in step 121, it is first determined whether or not the inclination θ (θ position, notch direction) matches. The details are as follows. First, as shown in FIG. 13, the transfer stage 3 is raised along the Z direction, and the wafer 90 is brought into contact with the lower surface of the mask 21. As a result, the focus of the second camera 52 is adjusted to the land 90 a of the wafer 90. While the second camera 52 is moved along the Y direction by the dispenser moving mechanism 25, the second camera 52 responds to the three measurement points A, B, and C through the minute opening 21a of the mask 21. Images of the lands 90a of the wafer 90 are acquired sequentially. Then, from the obtained images of the three lands 90a, the positions and areas of the three lands 90a are compared to determine whether or not the θ positions match. Although the acquired land image is blurred, the image of the land 90a is acquired in a state where the wafer 90 is separated from the mask 21 without raising the transfer stage 3 along the Z direction (see FIG. 14). Also good.

  FIG. 15 is a diagram illustrating a state where the θ position, the X position, and the Y position are not corrected. FIG. 15A illustrates an image acquired at point A, and FIG. FIG. 15C shows an image acquired at point B, and FIG. 15C shows an image acquired at point C. For example, as shown in these drawings, it is assumed that images having different areas of the three lands 90a are obtained. In this case, in step 122, the θ position is first finely adjusted so that the positions and areas of the three lands 90a are equal. That is, the wafer 90 is rotated around the center of the wafer 90.

  The position and area of the three lands 90a can be compared by displaying an image acquired by the camera 52 on a display prepared in the control section 60 and visually. Further, the image data acquired by the camera 52 may be subjected to image processing (image recognition), and the operations described above and below may be automatically performed by the control unit 30. Further, if the wafer 90 is rotated while the wafer 90 is in contact with the lower surface of the mask 21, the mask 21 may be damaged by the land 90 a of the wafer 90. Therefore, when the wafer 90 is rotated, as shown in FIG. 14, the transfer stage 3 is lowered along the Z direction so that the wafer 90 is not in contact with the lower surface of the mask 21.

  Note that the amount for finely adjusting the θ position (the amount of movement of θ) may be calculated by the operator, or may be automatically performed by the control unit 30 including image processing. Alternatively, an appropriate θ position may be obtained by appropriately setting the moving amount of θ and performing a trial and error. The fine movement (rotation) of the θ position may be performed manually by operating a switch or button prepared in advance in the control section 60, and using the result of comparing the positions and areas of the three lands 90a, It may be done automatically. The same applies to the case where the wafer 90 is moved in the X direction or the Y direction in the following.

  In step 122, after the θ position is finely moved (rotated), the process returns to step 121, and it is determined again whether the θ position matches. This is repeated until the θ positions match. If it is determined that the θ positions coincide with each other, in step 123, the θ position or the total angle (offset value) of the rotation angle of the wafer 90 from the initially aligned position is recorded.

  FIG. 16 is a diagram illustrating a state in which the θ position is corrected. FIGS. 16A, 16B and 16C show images acquired at points A, B and C, respectively. When the fine adjustment of the θ position is completed, as shown in FIG. 16, the shape and area where the land 90a is visible through the minute opening 21a are substantially the same.

  Next, in step 124, whether the X position and the Y position match using the images of the three lands 90a that are determined to have the same θ position (FIGS. 16A to 16C). Judge whether. 16A to 16C, the position of the land 90a is shifted in the X or Y direction with respect to the opening 21a. Therefore, in step 125, as shown in FIG. 14, the transfer stage 3 is lowered along the Z direction, and the wafer 90 is not in contact with the lower surface of the mask, and then the X position and / or the Y position are slightly moved. . Since the processing for this fine movement is common to the fine movement at the θ position, a detailed description is omitted.

  In step 125, after finely moving the X position and / or the Y position, the process returns to step 124 to determine again whether the X position and the Y position match. That is, as shown in FIG. 13, the transfer stage 3 is raised along the Z direction, the wafer 90 is brought into contact with the lower surface of the mask 21, and the second camera 52 is focused on the land 90 a of the wafer 90. While the second camera 52 is moved along the Y direction by the dispenser moving mechanism 25, the corresponding wafer is passed by the second camera 52 through the fine aperture 21a of the mask at the three measurement points A, B, and C. Images of 90 lands 90a are sequentially acquired. Then, from the obtained images of the three lands 90a, it is determined whether the X position and the Y position match. This is repeated until the X position and the Y position match each other. If it is determined that the X position and the Y position coincide with each other, in step 126, the total amount (offset) obtained by moving the wafer 90 in the X direction and the Y direction from the X position and the Y position or the initial alignment position. Value) is recorded.

  The fact that the θ position, the X position, and the Y position coincide with each other indicates that the minute opening 21a is occupied by the land 90a at each of the points A to C, as shown in FIG. It can be easily determined by obtaining an image in which the land 90a is stored. Therefore, in this state, if the ball Be is transferred into the mask opening 21a, the ball Be can be mounted on the land 90a with high accuracy.

  After the flux is applied, there is a possibility that the image of the land 90a cannot be obtained clearly, the wafer 90 is finely moved, or the flux adheres to the mask 21 when the mask 21 and the wafer 90 are overlapped. Therefore, in this example, the state in which the ball Be is mounted on the wafer 90 by the ball mounting mask 21 is realized by the wafer 90 before the flux is applied, and the image of the camera 52 is used instead of actually filling the ball Be. The result of mounting the ball Be is simulated. For this reason, the ball Be can be mounted on the wafer 90 with high accuracy by setting the wafer 90 on which the flux has been applied to the mask 21 in accordance with the simulation.

  As described above, according to the mounting apparatus 1 and the control method, when the wafer 90 is moved so that the wafer reference position Pw is determined by the first position P1, the ball mounting mask 21 is very small. Even if the position of the opening 21a is shifted from the position of the land 90a of the wafer 90, the second camera 52 acquires an image of the land 90a opposite to the position through the minute opening 21a, and the position of the minute opening 21a, The wafer 90 can be moved together with the transfer stage 3 such that the position of the wafer 90 can be finely adjusted so that the position of the land 90a facing it coincides. For this reason, the ball Be can be satisfactorily mounted on the land 90a of the wafer 90 with no deviation or very little.

  That is, according to the mounting apparatus 1 and the control method, the wafer 90 is arranged so that the wafer reference position Pw is the second position P2 with respect to the base 2, and the wafer is actually passed through the ball mounting mask 21. By mounting the ball Be on the ball 90, the ball Be can be mounted in a state of being aligned with higher accuracy than the alignment using the reference marks (for example, alignment marks). For this reason, in the mounting apparatus 1 and the control method, the wafer 90 on which the second position P2 is recorded and the other wafer 90 subsequent thereto are placed under the ball mounting mask 21 held by the ball mounting mask holder 22. The wafer 90 is moved by the transfer stage 3 so that the wafer reference position Pw of each wafer 90 becomes the second position P2, and the balls Be are placed on the ball mounting masks 21 by the ball dispensers 23a and 23b. By filling the minute openings 21 a, the balls Be can be mounted on the wafer 90 through the ball mounting mask 21.

  Moreover, according to the mounting apparatus 1 and the control method, the ball Be is mounted on the land 90a of the wafer 90 by using the second camera 52 to acquire an image of the land 90a that opposes the small opening 21a. It is possible to create a simulated state and finely adjust the position of the wafer 90. Accordingly, the state in which the ball Be is mounted on the land 90a of the wafer 90 is simulated without actually mounting the ball Be on the wafer 90 via the ball mounting mask 21, and the ball mounting mask 21, the wafer 90, Can be accurately aligned.

  Further, according to the mounting apparatus 1 and the control method, when the wafer 90 is moved so that the wafer reference position Pw is determined by the third position P3, the minute openings 11a of the flux coating mask 11 are formed. Even if the position is shifted from the position of the land 90a of the wafer 90, the third camera 53 obtains an image of the land 90a opposite to the position through the minute opening 11a, and the position of the minute opening 11a is opposed to the position. The wafer 90 can be moved together with the transfer stage 3 so that the position of the land 90a coincides, that is, the position of the wafer 90 can be finely adjusted. For this reason, the flux F can be satisfactorily applied on the land 90a of the wafer 90 in a state where there is no deviation or in a very small state.

  In addition, according to the mounting apparatus 1 and the control method, the flux F is applied on the land 90a of the wafer 90 by acquiring an image of the land 90a facing the micro opening 11a by the third camera 53. It is possible to create a simulated state and finely adjust the position of the wafer 90. Therefore, the state in which the flux F is applied onto the land 90a of the wafer 90 without actually applying the flux F to the wafer 90 via the flux application mask 11 is simulated, and the flux application mask 11 and the wafer 90 are Can be accurately aligned.

  In addition, according to the mounting apparatus 1, the second camera 52 is provided with the plurality of lands 90 a of the wafer 90 facing the plurality of minute openings 21 a through the plurality of minute openings 21 a of the ball mounting mask 21. Since the image can be acquired, the ball mounting mask 21 and the wafer 90 can be more accurately aligned.

  Similarly, the third camera 53 can acquire images of the plurality of lands 90a of the wafer 90 facing the plurality of minute openings 11a through the plurality of minute openings 11a of the flux coating mask 11. Thus, the flux application mask 11 and the wafer 90 can be aligned more accurately.

  Further, as in this example, when there are a plurality of image acquisition points (measurement points), the images of the obtained lands 90a can be compared. By comparing the position and the area of the land 90a, it becomes easy to determine whether the θ positions match.

  Further, since the mounting apparatus 1 has the second camera 52 mounted on the dispenser moving mechanism 25 and the third camera 53 mounted on the head moving mechanism 14, the second and third cameras 52 and 53 are mounted. Each moving mechanism can be omitted. Moreover, when the ball dispensers 23a and 23b are moved, the ball dispensers 23a and 23b interfere with the second camera 52, or when the flux application head 13 is moved, the flux application head 13 is moved to the third camera. 53 does not interfere.

  In this example, an image of the electrode 90a is acquired by the second camera 52 through the minute opening 21a of the ball mounting mask 21 at three points, but the second camera 52 uses the ball mounting mask. From above the ball mounting mask 21 held by the holder 22, an image of at least one electrode 90a facing the at least one minute opening 21a through the at least one minute opening 21a of the ball mounting mask 21 is obtained. The number of points for acquiring the image of the electrode 90a is arbitrary as long as it can be acquired.

  Similarly, in this example, an image of the electrode 90a is acquired by the third camera 53 at three points through the minute openings 11a of the flux application mask 11, but the third camera 53 is used for flux application. An image of at least one electrode 90a facing the at least one minute opening 11a from above the flux applying mask 11 held by the mask holder 12 through the at least one minute opening 11a of the flux applying mask 11. Can be acquired, and the number of points for acquiring the image of the electrode 90a is arbitrary.

  In this example, the first position, the third position, and the wafer reference position are obtained by calculating the center position from the coordinates of the two alignment marks, but the first position is obtained from the coordinates of one alignment mark. , The third position, and the wafer reference position may be obtained. Therefore, although the ball mounting mask 21 including the two alignment marks 21b and 21c is used, the number of the alignment marks 21b and 21c of the ball mounting mask 21 is arbitrary. Similarly, in this example, the flux coating mask 11 including the two alignment marks 11b and 11c is used, but the number of the alignment marks 11b and 11c of the flux coating mask 11 is arbitrary. Further, in this example, the wafer 90 including the two alignment marks 90b and 90c is used, but the number of the alignment marks 90b and 90c on the wafer 90 is arbitrary.

  In this example, an alignment mark is provided as a reference mark on the workpiece, but the workpiece reference mark is not limited to the alignment mark. It is also possible to use an electrode arrangement (electrode pattern) as a work reference mark. Further, it is possible to use an array (pattern) of minute openings as a reference mark on the mask side. Therefore, the alignment between the workpiece and the stage and the initial alignment between the workpiece and the mask may be performed by recognizing an image of the electrode and / or opening pattern.

  Further, in this example, the second camera 52 is mounted on the dispenser moving mechanism 25. However, a moving mechanism different from the dispenser moving mechanism 25 may be prepared, and the second camera 52 may be mounted on this moving mechanism. . Further, in this example, the third camera 53 is mounted on the head moving mechanism 14, but a moving mechanism different from the head moving mechanism 14 may be prepared, and the third moving camera may be mounted on this moving mechanism. .

The top view which shows the mounting apparatus concerning one Embodiment of this invention. The figure which abbreviate | omits a land and shows a wafer. It is a figure which shows a part of flux application apparatus with which the mounting apparatus of FIG. 1 is provided, Comprising: The figure which shows the state which apply | coated the flux to the mask for flux application. The figure which shows the state which has apply | coated the flux to the wafer. The figure which shows the state which the application | coating of the flux with respect to a wafer was complete | finished. The figure which shows a mask for ball mounting, omitting a minute opening. The figure which shows a part of ball | bowl filling apparatus with which the mounting apparatus of FIG. 1 is provided. The figure which expands and shows a part of FIG. The figure which shows schematic structure of the mounting apparatus of FIG. The flowchart which shows an example of the control method of the mounting apparatus of FIG. 11 is a flowchart showing an example of a control method in step 109 and step 111 in FIG. 10. The figure which shows the point which acquires an image. The figure which shows the position of a conveyance stage and a wafer at the time of acquiring the image of the land of the wafer which opposes the minute opening through the minute opening of the ball mounting mask. The figure which shows the position of a conveyance stage and a wafer when aligning a wafer with the mask for ball mounting. It is a figure which shows the state which is not correct | amending (theta) position, X position, and Y position, Comprising: (A) is a figure which shows the image acquired in the point A, (B) shows the image acquired in the point B FIG. 4C shows an image acquired at point C. FIG. It is a figure which shows the state which correct | amended (theta) position, Comprising: (A) is a figure which shows the image acquired in the point A, (B) is a figure which shows the image acquired in the point B, (C) is in the point C The figure which shows the acquired image. It is a figure which shows the state which correct | amended X position and Y position, Comprising: (A) is a figure which shows the image acquired in the point A, (B) is a figure which shows the image acquired in the point B, (C) is The figure which shows the image acquired in the point C. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Mounting apparatus, 2 Base 3 Conveyance stage, 10 Flux application apparatus 11 Flux application mask 11a Micro opening 11b (of flux application mask) 11c, Alignment mark (reference mark) of flux application mask
DESCRIPTION OF SYMBOLS 12 Flux application mask holder 13 Flux application head 14 Head movement mechanism 20 Ball filling device 21 Ball mounting mask 21a Micro opening 21b (for ball mounting mask) 21c, alignment mark (for ball mounting mask) mark)
22 Ball mounting mask holder, 23a, 23b Ball dispenser 25 Dispenser moving mechanism, 30 Control unit 40 Memory, 51a, 51b First camera 52 Second camera, 53 Third camera 90 Wafer (work), 90a Land ( electrode)
90b, 90c (wafer) alignment mark (reference mark)
Be ball, F flux

Claims (8)

A mounting device for mounting a ball on the plurality of electrodes of a workpiece having a plurality of electrodes on the surface,
Base and
A ball mounting mask holder for holding a ball mounting mask having a plurality of minute openings for mounting a ball on the workpiece in a first position with respect to the base;
A transfer stage capable of holding the workpiece and moving the workpiece to a predetermined position with respect to the base;
A first camera capable of detecting a reference mark of the workpiece mounted on the transfer stage and recording the position of the workpiece with respect to the transfer stage in a memory as a workpiece reference position;
At least one of the workpieces facing the at least one small opening from above the ball mounting mask held by the ball mounting mask holder via at least one small opening of the ball mounting mask. A second camera capable of acquiring an electrode image;
A ball dispenser for filling a plurality of minute openings of the ball mounting mask from above the ball mounting mask held by the ball mounting mask holder;
And a control unit capable of controlling a destination of the transfer stage. The control unit according to claim 1, wherein:
The workpiece is moved under the ball mounting mask held by the ball mounting mask holder so that the workpiece reference position is determined by the first position by the transfer stage, The workpiece reference position when at least one minute opening of the ball mounting mask and the at least one electrode opposed to the at least one minute opening are aligned via the second camera. A first function for obtaining and recording a second position relative to the base in the memory;
The workpiece is moved under the ball mounting mask held by the ball mounting mask holder by the transfer stage so that the workpiece reference position becomes the second position, and the ball dispenser And a second function of filling a plurality of micro openings in the ball mounting mask with the ball so that the ball is mounted on the plurality of electrodes of the workpiece.   The mounting apparatus according to claim 1, wherein the second camera is capable of detecting a reference mark of the ball mounting mask and recording the first position in the memory.   4. The second camera according to claim 1, wherein the second camera has at least two electrodes of the workpiece facing the at least two minute openings through the at least two minute openings of the ball mounting mask. An on-board device that can acquire images.   5. The mounting device according to claim 1, further comprising a dispenser moving mechanism that moves the ball dispenser, wherein the second camera is movable by the dispenser moving mechanism. In any of claims 1 to 5,
A flux application mask holder for holding a flux application mask having a plurality of minute openings for applying flux to the workpiece in a third position with respect to the base;
At least one of the workpieces facing the at least one minute opening from above the flux application mask held by the flux application mask holder through at least one minute opening of the flux application mask. A third camera capable of acquiring an electrode image;
A flux application head for applying flux from above the flux application mask held by the flux application mask holder through a plurality of minute openings of the flux application mask;
The control unit is
Under the flux application mask held by the flux application mask holder, the workpiece is moved by the transfer stage so that the workpiece reference position is determined by the third position, The workpiece reference position when the at least one minute opening of the flux application mask and the at least one electrode facing the at least one minute opening are aligned via the third camera. A third function for obtaining and recording a fourth position relative to the base in the memory;
The workpiece is moved under the flux coating mask held by the flux coating mask holder so that the workpiece reference position becomes the fourth position by the transfer stage, and the flux coating mask is used. And a fourth function of applying a flux to the plurality of electrodes of the workpiece through the plurality of minute openings of the flux application mask by a head.   The mounting apparatus according to claim 6, further comprising a head moving mechanism that moves the flux application head, wherein the third camera is movable by the head moving mechanism. A method of controlling a mounting device for mounting a ball on the plurality of electrodes of a workpiece having a plurality of electrodes on a surface by a control unit,
The mounting device is
Base and
A ball mounting mask holder for holding a ball mounting mask having a plurality of minute openings for mounting the ball on the workpiece against the base;
A transfer stage capable of holding the workpiece and moving the workpiece to a predetermined position with respect to the base;
A first camera capable of detecting a reference mark of the workpiece mounted on the transfer stage;
At least one of the workpieces facing the at least one small opening from above the ball mounting mask held by the ball mounting mask holder via at least one small opening of the ball mounting mask. A second camera capable of acquiring an electrode image;
A ball dispenser for filling a plurality of minute openings of the ball mounting mask from above the ball mounting mask held by the ball mounting mask holder;
A control unit capable of controlling the destination of the transfer stage;
The method is
Detecting a reference mark of the ball mounting mask held by the ball mounting mask holder by the second camera, and recording a first position of the ball mounting mask with respect to the base in a memory; ,
Detecting a reference mark of the workpiece mounted on the transfer stage by the first camera, and recording the position of the workpiece with respect to the transfer stage as a workpiece reference position in the memory;
The workpiece is moved under the ball mounting mask held by the ball mounting mask holder so that the workpiece reference position is determined by the first position by the transfer stage, The workpiece reference position when at least one minute opening of the ball mounting mask and the at least one electrode opposed to the at least one minute opening are aligned via the second camera. Obtaining a second position relative to the base and recording the second position in the memory;
The workpiece is moved under the ball mounting mask held by the ball mounting mask holder by the transfer stage so that the workpiece reference position becomes the second position, and the ball dispenser Filling a plurality of micro openings in the ball mounting mask with a ball.

Images