Patent Publication Number: US-7905268-B2

Title: Ultrasonic bonding apparatus

Description:
This application is a continuation based on International Application No. PCT/JP2007/056562. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to an ultrasonic bonding (or welding) apparatus, and more particularly to an ultrasonic bonding apparatus configured to fill an underfill in a space between a chip (electronic component) and a substrate, and to bond the chip and the substrate with each other through the underfill. The present invention is suitable, for example, for an ultrasonic bonding apparatus configured to mount a bare chip (flip-chip: FC). 
     2. Description of the Related Art 
     Flip-chip mounting is a known technology alternative to wire bonding, which electrically connects a chip to a substrate via an array of bumps. The underfill is filled in a space between the chip and the substrate so as to mitigate an external stress and to improve the reliability of the connection. Recently, as a chip size reduces in order of a ball grid array (“BGA”), a chip size package (“CSP”), and the FC, an interval between the chip and the substrate becomes smaller. Thus, filling the underfill after mounting (this process will be referred to as “post-filling” of the underfill hereinafter) becomes difficult, and filling the underfill before mounting is necessary (this process will be referred to as “pre-filling” of the underfill hereinafter). 
     The ultrasonic bonding apparatus is mounted with the chip on a (tool) surface of an ultrasonic head on the substrate side, and bonds the chip onto the substrate by pressing the chip upon the substrate while applying the ultrasonic wave. 
     Prior art include, for example, Japanese Patent Applications, Publication Nos. 08-195063, 2001-30465, 56-3447, 05-345411, 2002-53110, 60-234282, 2002-313837, 02-260552, 2004-342847, 2004-207294, 2005-302750, 2005-72033, and 08-264584, Japanese Utility Model Publication No. 06-38828, Japanese Utility Model Registration No. 2,562,897, and Japanese Patent No. 2,987,386. 
     In the pre-filling, the chip is pressed and bonded while the underfill is being placed on the substrate. Therefore, the underfill under the chip is forced out in the press time, and adheres to and contaminates the tool surface. As the head&#39;s temperature becomes higher, the underfill that has adhered to the tool surface cures to lower the parallelism of the tool surface, and the transmissibility of the ultrasonic vibration deteriorates. As a result, the parallelism between the chip and the substrate degenerates, and the bonding quality becomes worse. 
     Since the ultrasonic bonding apparatus polishes the tool surface so as to maintain the flatness of the tool surface, the post-cured underfill can be eliminated through polishing. However, the pre-cured underfill cannot be removed by using the polishing machine because the pre-cured underfill clogs a polishing grindstone. In this respect, there is proposed a method for applying the ultrasonic wave while a film is held between the tool surface and the chip at the mounting time. However, this method can cause a transmission of the ultrasonic vibration to be insufficient, and a slide occurs on both surfaces of the inclusion (film) and the bonding quality becomes unstable. 
     SUMMARY OF THE INVENTION 
     The present invention provides an ultrasonic bonding apparatus configured to maintain a tool surface clean. 
     An ultrasonic bonding apparatus according to one aspect of the present invention used to manufacture an electronic device that includes a substrate, an electronic component, and an underfill that is filled in a space between the electronic component and the substrate includes a head that includes a tool surface configured to mount the electronic component, a wiping unit configured to wipe out pre-cured underfill that has adhered to the tool surface of the head, by using a wiping member on a wiping table, an ultrasonic bonding unit configured to ultrasonically bond the electronic component with the substrate and to press the head against the wiping member on the wiping table, a detector configured to detect a first pressure applied between the wiping member on the wiping table and the tool surface when the wiping unit provides wiping, and a controller configured to control a second pressure applied by the ultrasonic bonding unit, based on a detection result by the detector. This ultrasonic bonding apparatus can maintain the properly set pressure, improve the wiping performance, and maintain the tool surface clean. 
     An ultrasonic bonding apparatus according to another aspect of the present invention used to manufacture an electronic device that includes a substrate, an electronic component, and an underfill that is filled in a space between the electronic component and the substrate includes a head that includes a tool surface configured to mount the electronic component, a wiping unit configured to wipe out pre-cured underfill that has adhered to the tool surface of the head, by using a wiping member on a wiping table, the wiping unit including a solvent supply unit configured to supply a solvent configured to powder the underfill, to the wiping member on the wiping table, an ultrasonic bonding unit configured to ultrasonically bond the electronic component with the substrate and to press the head against the wiping member on the wiping table, a detector configured to detect a pressure applied between the wiping member on the wiping table and the tool surface when the wiping unit provides wiping, and controller configured to control a solvent supply amount by the solvent supply unit, based on a detection result by the detector. This ultrasonic bonding apparatus can maintain a solvent supply amount appropriate to the wiping member, improve the wiping performance, and maintain the tool surface clean. 
     An ultrasonic bonding apparatus according to still another aspect of the present invention used to manufacture an electronic device that includes a substrate, an electronic component, and an underfill that is filled in a space between the electronic component and the substrate includes a head that includes a tool surface configured to mount the electronic component, a wiping unit configured to wipe out pre-cured underfill that has adhered to the tool surface of the head, by using a wiping member on a wiping table, the wiping unit including a feed mechanism that includes a motor and is configured to supply the wiping member to the wiping table and to roll up the wiping member from the wiping table, an ultrasonic bonding unit configured to ultrasonically bond the electronic component with the substrate, a detector configured to detect a variation of a torque of the motor, and a controller configured to determine whether a residual amount of the wiping member is sufficient, based on a detection result by the detector. This ultrasonic bonding apparatus can recognize a residual amount of the wiping member, avoid wiping when there is no wiping member, and maintains the tool surface clean. 
     An ultrasonic bonding apparatus according to another aspect of the present invention used to manufacture an electronic device that includes a substrate, an electronic component, and an underfill that is filled in a space between the electronic component and the substrate includes a head that includes a tool surface configured to mount the electronic component, a wiping unit configured to wipe out pre-cured underfill that has adhered to the tool surface of the head, by using a wiping member on a wiping table, an ultrasonic bonding unit configured to ultrasonically bond the electronic component with the substrate, a detector configured to detect a dirt state on the tool surface by taking an image of a surface of the electronic component that has been bonded with the substrate, and a controller configured to control wiping timing by the wiping unit, based on a detection result by the detector. This ultrasonic bonding apparatus can perform when the tool surface is dirty, and maintain the tool surface clean. When the tool surface is not dirty, the controller can avoid wiping and maintain the throughput of the ultrasonic bonding. 
     Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a block diagram of an ultrasonic bonding apparatus according to one aspect of the present invention. 
         FIG. 2  is a schematic sectional view of an electronic device manufactured by the ultrasonic bonding apparatus shown in  FIG. 1 . 
         FIG. 3  is an exploded perspective view of a wiping unit shown in  FIG. 1  on a front surface side. 
         FIG. 4  is a perspective view of the wiping unit shown in  FIG. 3  on a back surface side. 
         FIG. 5  is a schematic sectional view showing one example of a swing mechanism applicable to the wiping unit shown in  FIG. 3 . 
         FIG. 6A  is a schematic sectional view of a pressure distribution on a tool surface and its state when a head is pressed against a wiping table with no elastic member.  FIG. 6B  is a schematic sectional view of a pressure distribution on a tool surface and its state when the head is compressed against the wiping table with an elastic member. 
         FIG. 7A  is a schematic sectional view before the head is pressed against a wiping table having a rough surface.  FIG. 7B  is a schematic sectional view showing that the head is pressed against and swung on the wiping table shown in  FIG. 7A . 
         FIG. 8  is a schematic sectional view of a wiping unit having a variation of the swing mechanism shown in  FIG. 5 . 
         FIG. 9  is a schematically enlarged perspective view near the wiping table of the wiping unit shown in  FIG. 8 . 
         FIG. 10  is a plane view of the wiping unit shown in  FIG. 8 . 
         FIG. 11  is a sectional view of the wiping unit shown in  FIG. 8 . 
         FIG. 12  is a sectional view of the wiping unit shown in  FIG. 8 . 
         FIG. 13A  is a schematically partially sectional view showing an unclamp state of a clamp/unclamp mechanism applicable to the wiping unit shown in  FIG. 8 .  FIG. 13B  is a schematically partially sectional view showing a clamp state of the clamp/unclamp mechanism applicable to the wiping unit shown in  FIG. 8 . 
         FIGS. 14A and 14B  are schematically sectional views showing one example of the clamping/unclamp mechanism shown in  FIGS. 13A and 13B . 
         FIGS. 15A and 15B  are schematically sectional views showing another example of the clamping/unclamp mechanism shown in  FIGS. 13A and 13B . 
         FIG. 16  is a graph showing a relationship between a residual amount of a wiping member in a feed reel shown in  FIG. 3  or a take-up diameter of a take-up roller, and a torque of a motor. 
         FIG. 17A  is an enlarged perspective view near a connection part between a connection shaft and a shaft of the take-up reel.  FIG. 17B  is a plane view and an A-A sectional view of the connection shaft shown in  FIG. 17A .  FIG. 17C  is a sectional view of an engagement state of both shafts shown in  FIG. 17A .  FIG. 17D  is a sectional view of the connection shaft inserted into the shaft of the feed reel. 
         FIG. 18  is a schematic sectional view of a tension application mechanism of the wiping unit shown in  FIG. 3 . 
         FIG. 19  is a schematic sectional view showing one example of a state detection system of the wiping unit shown in  FIG. 3 . 
         FIG. 20  is a schematic sectional view showing another example of a state detection system of the wiping unit shown in  FIG. 3 . 
         FIG. 21  is a schematic sectional view of the state detection system that uses a guide roller shown in  FIG. 19 . 
         FIG. 22  is a schematically partially sectional view of a variation of a feed system shown in  FIG. 3 . 
         FIG. 23  is a graph showing a relationship between the number of mounts of the chip C and the oscillation impedance of the ultrasonic wave. 
         FIG. 24  is a flowchart for explaining an operation of the ultrasonic bonding apparatus shown in  FIG. 1 . 
         FIG. 25  is a flowchart for explaining details of the step  1300  shown in  FIG. 24 . 
         FIG. 26A  is a graph that compares the pressure applied to the wiping member whether or not there is a pressure control of the step  1328  shown in  FIG. 25 .  FIG. 26B  is a block diagram of the pressure control. 
     
    
    
     DESCRIPTION OF THE EMBODIMENTS 
     Referring now to  FIGS. 1 and 2 , a description will be given of an ultrasonic bonding apparatus  100  according to one aspect of the present invention.  FIG. 1  is a block diagram of the ultrasonic bonding apparatus  100 .  FIG. 2  is a schematic sectional view of the electronic device  10 . 
     The ultrasonic bonding apparatus  100  is an apparatus used to manufacture the electronic device  10  shown in  FIG. 2 , and serves to ultrasonically bond a chip (electronic component) C with a substrate B. The electronic device  10  includes a substrate B, a chip C mounted onto or electrically connected to the substrate B via bumps N, and an underfill UF filled in a space between the chip C and the substrate B. More specifically, each bump N is connected to the chip C and the substrate B via a pad (not shown). 
     The ultrasonic bonding apparatus  100  includes, as shown in  FIG. 1 , a main controller  102 , a head  104 , an ultrasonic bonding unit, an alignment unit, and a wiping unit  140 . 
     The main controller  102  is connected to the ultrasonic bonding unit, the alignment unit, the wiping unit  140 , and other various types of controllers, and controls each component. The main controller  102  is a processor, such as a MPU or CPU, a memory, such as a ROM, a RAM, or a hard disc drive, and an input unit, such as a keyboard or a mouse, and an indicator, such as a display. Each of the other controllers, which will be described later, also has a memory. 
     The head  104  includes, on the bottom side, a tool surface  105  configured to mount the chip (electronic component) C. The bottom of the head  104  may be flat or have concaves. In  FIG. 1 , the tool surface  105  is not seen. The tool surface  105  opposes to the substrate B. The head  104  is provided with an ultrasonic transducer  122 , but a member connected to the head  104  may possess it. A press mechanism  112  is attached to a top surface  106  of the head  104  that is opposite to the tool surface  105 . The head  104  may be exchanged according to a type of the chip C. 
     The ultrasonic bonding unit serves to ultrasonically bond the chip C with the substrate B, and includes a press unit and an ultrasonic applicator. The press unit is a driver configured to drive the head in a Z direction in which the chip C is pressed against the substrate B, and includes a press controller  110  and the press mechanism  112 . 
     The press controller  110  is connected to the main controller  102 , and its operation is controlled by the main controller  102 . The press controller  110  controls the press mechanism  112 . 
     The press mechanism  112  includes a body  113  and a drive shaft  115 . The body  113  includes a Z stage that can expand and constrict the drive shaft in the Z direction. One end of the drive shaft  115  is connected to the body  113  directly or indirectly via a load sensor  114  as a detector, and the other end of the drive shaft  115  is fixed onto the top surface  106  of the head  104 . The drive shaft  115  has a heater (not shown), and the temperature of the heater is controlled by the press controller  110 . 
     The ultrasonic applicator applies the ultrasonic wave to the chip C on an XY plane orthogonal to the Z direction, and includes an ultrasonic generator  120  and an ultrasonic transducer  122 . The ultrasonic generator  120  converts an electric signal, for example, of 50 Hz into an electric signal of 20 kHz or 35 kHz. The ultrasonic transducer  122  includes a piezoelectric element configured convert an electric signal into the mechanical vibration energy. The ultrasonic transducer  122  transmits a vibration to the head  104  via a horn (resonance member) (not shown). 
     The ultrasonic applicator can use a structure known in the art, and a description thereof will be omitted. 
     The alignment unit provides an alignment between the chip C and the substrate B, and includes an alignment mechanism controller  131 , an image pickup unit  132 , a movement mechanism  133 , an image processor  134 , a movement mechanism controller  135 , and an alignment mechanism  136 . 
     The alignment mechanism controller  131 , the image processor  134 , and the movement mechanism controller  135  are controlled by the main controller  102 . The alignment mechanism controller  131  controls an operation of the alignment mechanism  136  based on a result of the image processor  134 . 
     The image pickup unit  132  has a camera, and can take images of the top and bottom surfaces or the tool surface  105  and the substrate B. More specifically, the image pickup unit  132  takes images of a mark (not shown) formed on the tool surface  105  and aligned with the chip C, and a mark (not shown) formed on the substrate B near the chip mounting position and aligned with the chip mounting position. 
     The image pickup unit  132  is driven by the movement mechanism  133 . The movement mechanism  133  includes a three-dimensional stage, and three-dimensionally moves the image pickup unit  132 . The image processor  134  processes both mark images taken by the image pickup unit  132  and superimposes both marks when they are viewed from the Z direction. 
     The movement mechanism controller  135  controls driving of the movement mechanism  133 . More specifically, in photographing the marks, the image pickup unit  132  is moved to the image pickup position, and in ending the alignment, the image pickup unit  132  is retreated. 
     The alignment mechanism  136  is a three-dimensional stage mounted with the substrate B, and can move the substrate B in the three-dimensional direction. In operation, the alignment mechanism controller  131  obtains an image pickup result from the image processor  134 , and controls driving of the alignment mechanism  136  so that both marks can overlap each other in a predetermined positional relationship. 
     The alignment unit can apply a structure known in the art, and a detailed description thereof will be omitted. 
     The wiping unit  140  serves to wipe out the underfill UF that has adhered to the tool surface  105  of the head  104 , by using the wiping member W. The ultrasonic bonding apparatus  100  of this embodiment adopts the pre-filling method in which the head  104  is pressed against the substrate B while the underfill UF is previously applied onto the substrate B. Therefore, the underfill UF is likely to adhere to the tool surface  105  when the head  104  is pressed upon the substrate B. The wiping unit  140  wipes out the underfill UF and maintains the tool surface  105  clean. 
     The wiping member W is a tape or stripe member used to wipe out the underfill UF. In this embodiment, the wiping member W is made of cloth but the present invention does not limit its material. 
     The wiping unit  140  includes, as shown in  FIGS. 1 ,  3 - 20 , a body, a feed system, a state detection system, a solvent supply system, and a timing control system.  FIG. 3  is an exploded perspective view of the wiping unit  140  when it is viewed from the front side, and  FIG. 4  is a perspective view of the wiping unit  140  when it is viewed from the rear side. 
     The body includes a wiping unit controller  141 , a cartridge  142 , a cartridge support member  144 , a cartridge orientation adjuster  145 , a drive stage  146 , a drive stage orientation adjuster  147 , a shutter  148 , and a wiping table  149 . 
     The wiping unit controller  141  controls a movement of the drive stage  146  in the X direction, and is controlled by the press controller  110 . 
     The cartridge  142  is an approximately L-shaped hollow housing, and can be engaged with and disengaged from the cartridge support member  144  on the surface  142   a . The cartridge  142  can be separated from the cartridge support member  144 , and thus an attachment, a detachment, or an exchange can be performed in a unit of the cartridge  142 . As a result, an exchange and maintenance of the wiping member W can become easy, and the number of operational steps can be saved. In addition, the wiping member W can be exchanged in an off-line operation, and the operating rate of the wiping unit  140  improves. 
     Since the solvent is used and the solvent can use flammable solution, such as alcohol, as described later, the cartridge  142  may be made of a waterproof and explosion-proof construction. The cartridge  142  has an airtight structure for a waterproof construction, as described later. No motor or sensor is provided in the cartridge  142  for the explosion-proof structure, and the internal state is detected from the outside. 
     The cartridge  142  has a box frame shape, and houses the wiping member W, the wiping table  149 , a take-up reel  152 , a feed reel  154 , and a plurality of guide rollers  156 . Although the cover  143  is detached in  FIG. 3 , the cover  143  is attached to the cartridge  142  as shown in  FIG. 6 , which will be described later, so as to close the cartridge  142 . 
     The cartridge  142  is attached to the drive stage  146  via the cartridge support member  144 . The cartridge  142  and the cartridge support member  144  are integrally moved to and retreated from the wiping position by the drive stage  146 . At the wiping time, the cartridge  142  and the cartridge support member  144  are swung as one member by the drive stage  146 . However, as described in another embodiment, which will be described later, only part of the member housed by the cartridge  142 , such as the wiping table  149 , may be swung. 
     The cartridge support member  144  has an L shape, as shown in  FIG. 3 , and includes a variety of drive systems and detection systems. The cartridge support member  144  is connected to the drive stage  146  on the bottom surface of the L-shaped bottom plate, and can be driven in the X direction by the drive stage  146 . The cartridge support member  144  can be engaged with and disengaged from the cartridge  142  on the surface  144   a  that is one surface of an L-shaped erector, and the motor  150  and a detection system are attached to a surface  144   b  that is another surface of the L-shaped erector. 
     The cartridge orientation adjuster  145  is arranged between the cartridge support member  144  and the drive stage  146 , as shown in  FIG. 4 , and is a following mechanism of adjusting an orientation (θx, θy) of the wiping member W on the wiping table  149  of the cartridge  142  so that the wiping member W can be parallel to the tool surface  105 . As a result, the contact pressure between the wiping member W and the tool surface  105  can be made uniform in a surface at the wiping time. 
     The cartridge orientation adjuster  145  can eliminate shifts caused by the individual differences of the cartridge  142 , and adjust an orientation of the cartridge  142  when the head  104  is replaced and when the cartridge  142  is replaced. This adjustment may be manual or automatic. The cartridge orientation adjuster  145  prevents a point contact between the wiping member W and the tool surface  105  at the wiping time, and provides the average wiping to the entire tool surface  105 . As a result, the wipe operation becomes stable, and the underfill UF can be surely wiped out so as to extend the life of the head  104 . The cartridge orientation adjuster  145  includes a stage that can independently rotate around the X axis (θx) and around the Y axis (θy), as shown in a detailed perspective view at the bottom of  FIG. 4 . 
     The drive stage  146  is fixed onto the cartridge support member  144 , and moves the cartridge support member  144  to the wiping position along the X direction, and retreats the cartridge support member  144  from the wiping position along the X direction. The X direction is a direction perpendicular to the Y direction that is the ultrasonic oscillation direction. In this embodiment, the ultrasonic oscillation direction is perpendicular to the wiping direction. 
     In one embodiment, the wiping unit controller  141  controls the drive stage  146  to swing the cartridge support member  144  in the X direction at the wiping time.  FIG. 5  shows this state.  FIG. 5  is a schematic sectional view of the wiping unit  140 . In  FIG. 5 , the cartridge orientation adjuster  145  and the drive stage orientation adjuster  147  are omitted. In  FIG. 5 , the drive stage  146  includes a fixed member  146   a , and a movable member  146   b  that swings in an arrow direction (X direction) relative to the fixed member  146   a . The movable member  146   b  swings in a range between dotted positions before and after the solid line position. 
     Thus, for wiping of the tool surface  105 , the entire cartridge  142  is moved parallel to the tool surface  105  by the drive stage  146 . Since the same actuator serves both as means for moving the cartridge  142  to the wiping position and means for swinging for wiping, the mechanism of the cartridge  142  can be made simple and the cost can be reduced. 
     The drive stage orientation adjuster  147  is fixed under the drive stage  146 , and is a following mechanism configured to adjust an orientation (θx, θy) of the drive stage  146 . The drive stage orientation adjuster  147  adjusts the orientation of the drive stage  146  so that the pressure between the wiping member W and the tool surface  105  can be constant in the plane of the tool surface  105  over the wiping stroke. The drive stage orientation adjuster  147  can eliminate shifts caused by the individual differences of the head  104 , and adjusts an orientation of the drive stage  146  when the head  104  is replaced. This adjustment may be manual or automatic. The drive stage orientation adjuster  147  prevents a point contact of the tool surface  105  at the wiping time, and provides average wiping to the entire tool surface  105 . As a result, the wipe operation becomes stable, the underfill UF can be surely wiped out, and the life of the head  104  can be extended. The drive stage orientation adjuster  147  includes a stage that can rotate independently around the X axis (θx) and around the Y axis (θy) as shown in the detailed perspective view at the bottom of  FIG. 4 . 
     The shutter  148  is provided over the wiping table  149 . When the shutter  148  opens, the wiping member W exposes on the wiping table  149 . The wiping table  149  is formed in the cartridge  142  in this embodiment, and a bottom of the head  104  is inserted into the shutter  148  down to the wiping member W above the wiping table  149  while the tool surface  105  faces down. The wiping table  149  may be formed on a convex of the cartridge  142 , and the bottom of the head  104  may be made flat. 
     When the shutter  148  is closed, it seals the wiping member W above the wiping table  149 . The shutter  148  is opened and closed by the wiping unit controller  141 , and the shutter  148  or a shutter opening/closing mechanism (not shown) connected to the shutter  148 . 
     The wiping member W is supplied to the top of the wiping table  149 , and used to wipe out the underfill UF on the tool surface  105 . The wiping table  149  is supplied with the clean wiping member W, and the dirty wiping member W on the wiping table  149  is rolled up. The press mechanism  112  can press the tool surface  105  of the head  104  upon an exposed part of the wiping member W above the wiping table  149 . At the wiping time, the tool surface  105  is not mounted with the chip C. 
     As shown in  FIGS. 6A and 6B , the wiping table  149  may be covered with an elastic member  149   a , and configured to contact the wiping member W via the elastic member  149   a .  FIG. 6A  is a schematic sectional view showing the pressure distribution of the tool surface  105  and its state when the head  104  is pressed against the wiping table  149  with no elastic member  149   a .  FIG. 6B  is a schematic sectional view showing the pressure distribution of the tool surface  105  and its state when the head  104  is pressed against the wiping table  149  via the elastic member  149   a . In  FIGS. 6A and 6B , the wiping member W is omitted. 
     It is difficult to make both the top surface of the wiping table  149  and the tool surface  105  perfectly flat, and to maintain them perfectly parallel to each other. Hence, as shown in an upper graph of  FIG. 6A , the pressure distribution of the tool surface  105  is likely to become non-uniform when there is no elastic member  149   a . On the other hand, when there is the elastic member  149   a  as shown in  FIG. 6B , the pressure distribution of the tool surface  105  is likely to become uniform. As a result, the tool surface  105  can be wiped out averagely, the wipe operation becomes stable, the underfill UF can be surely wiped out, and the life of the head  104  can be extended. 
     A wiping table  149 A may be used which has an uneven surface that is made by forming convexes and concaves on the surface of the wiping table  149 .  FIG. 7A  is a schematic sectional view before the head  104  is pressed upon the wiping table  149 A having an uneven surface  149 A 1 .  FIG. 7B  is a schematic sectional view when the head  104  is pressed upon the wiping table  149 A and swung. Each convex of the uneven surface  149 A 1  has the same height, and the same triangular prism shape. However, the present invention does not limit the shape of the convex, such as a conical shape. 
     When the wiping table  149  has a plane surface and surface-contacts the tool surface  105 , the surface of the wiping table  149  may not follow fine uneven shape on the tool surface  105 . Point contacts or a surface contact in a fine area using the uneven surface  149 A 1  provides average wiping of the entire tool surface  105 . As a result, the wipe operation becomes stable, the underfill UF can be surely wiped out, and the life of the head  104  can be extended. 
     While the cartridge  142  entirely swings in the example shown in  FIG. 5 , only the wiping table  149  may swing. Referring now to  FIGS. 8 to 12 , a description will be given of an embodiment having such a wiping table  190 .  FIG. 8  is a schematic sectional view of the wiping unit  140 A having the wiping table  190 . As shown in  FIG. 8 , the cartridge  142  is fixed, and only the wiping table  190  swings in the X direction in a range enclosed by a dotted line and a solid line. 
       FIG. 9  is a schematic perspective view near the wiping table  190 .  FIG. 10  is a schematic plane view near the wiping table  190 .  FIG. 11  is a schematic sectional view near the wiping table  190 .  FIG. 12  is a schematic sectional view near the wiping table  190 . 
     The wiping unit  140 A includes a swing mechanism, a clamp mechanism, and an unclamp mechanism. 
     The swing mechanism swings the wiping table  190  in the X direction relative to the cartridge  142 . The swing mechanism includes, as shown in  FIGS. 9-11 , a motor  192  provided on the side of the cartridge support member  144 , a decentering cam  193  having a shaft  193   a  connected to a motor shaft  192   a  of the motor  192 , a pair of guides  194 , and a pair of side plates  195 . 
     As shown in  FIG. 12 , the decentering cam  193  is housed in a cavity  190   a  in the wiping table  190 . The decentering cam  193  approximately contacts the inner wall of the cavity  190   a  in the X direction. The wiping table  190  is pierced by the two pairs of guides  194 , and can move along the guides  194  relative to the guides  194 . Both ends of the pair of guides  194  are fixed onto a pair of side plates  195  fixed onto the cartridge  142 . When the decentering cam  193  rotates around the shaft  193   a , the wiping table  190  swings in the X direction along the guides  194 . 
     The clamp mechanism is a mechanism of clamping the wiping member W so that the wiping member W can follow a swing of the wiping table  190 . The clamp mechanism includes, as shown in  FIGS. 9-12 , a press plate  196   a , a pair of support shaft  196   b , a bottom plate  196   c , and a clamping spring  196   d.    
     The clamping spring  196   d  is a tension spring: Its one end contacts the ceiling of each cavity  190   b  formed in the wiping table  190 , and its other end contacts the top surface of the bottom plate  196   c . Therefore, the clamping spring  196   d  always applies a vertically downward force to the bottom plate  196   c  (downwardly in the Z direction). This elastic force is transmitted to the press plate  196   a  via the support shaft  196   b . As a result, the press plate  196   a  always compresses the wiping member W in the downward direction, and the wiping member follows the swing of the wiping table  190 . 
     Thus, at the wiping time, the clamp mechanism clamps the wiping member W and the head  104  is pressed against the wiping member W. In this state, the swing mechanism simultaneously swings the wiping table  190 , the wiping member W, and the clamp mechanism. Since the mass of the object to be swung becomes smaller in comparison with the mass when the cartridge  142  and cartridge support member  144  are entirely swung, the vibrations reduce. In addition, different from  FIG. 5 , the drive stage  146  does not need to swing, the power consumption can be smaller, and the cost can be reduced. 
     The unclamp mechanism is a mechanism configured to release clamping by the clamp mechanism in feeding the wiping member W at the end of the wiping etc. The unclamp mechanism includes a motor  197  provided on the side of the cartridge support member  144 , and a decentering cam  198  having a shaft  198   a  connected to a motor shaft  197   a  of the motor  197 . The unclamp mechanism is in the state shown in  FIG. 12  at the wiping time. On the other hand, in feeding the wiping member W from the state shown in  FIG. 12 , the motor  197  rotates the decentering cam  198  by 180° around the shaft  198   a . Then, the decentering cam  198  presses the bottom surface of the bottom plate  196   c  upwardly in the Z direction. As a result, the press plate  196   a  together with the support shafts  196   b  displaces upwardly in the Z direction, and separates from the wiping member W for unclamping. 
     Referring now to  FIGS. 13A-15B , a description will be given of a variation of the clamp/unclamp mechanism. This variation utilizes the shutter  148  and the movement mechanism of the shutter  148  for the clamp/unclamp of the wiping member W. The shutter  148  has an opening  148   a.    
       FIG. 13A  is a schematic sectional view showing a relationship among the shutter  148 , the wiping member W, and the wiping table  190  in the unclamp state.  FIG. 13B  is a schematic sectional view showing a relationship among the shutter  148 , the wiping member W, and the wiping table  190  in the clamp state. An opening state is given when the opening  148   a  of the shutter  148  is located just below the opening  142   c  of the cartridge  142 , as shown in  FIG. 13B . 
     In  FIG. 13A , the shutter  148  is located at an unclamp position and at a close position that closes the opening  142   c  of the cartridge  142 . In  FIG. 13B , the shutter  148  is located at a clamp position and at an open position that opens the opening  142   c  of the cartridge  142 .  FIGS. 14A and 14B  show one example of the clamp/unclamp mechanism configured to move the shutter between the state shown in  FIG. 13A  and the state shown in  FIG. 13B .  FIGS. 15A and 15B  show another example of the clamp/unclamp mechanism. 
     The clamp/unclamp mechanism shown in  FIGS. 14A and 14B  utilizes a linkage, and includes a support plate  148   b  and a pair of rods  148   c.    
     The support plate  148   b  is a plate member in this embodiment, and fixed on one side surface of the shutter  148  but may have a box-shaped member that opens at part of the top surface. In addition, it may be a plate member or a pair of support plates  148   b  may be fixed at both side surfaces of the shutter  148 . In this embodiment, the support plate  148   b  is connected to the shutter  148  on its top surface. Moreover, the opening/closing means (not shown) of the shutter  148  is fixed onto the shutter  148  or the support plate  148   b.    
     A pair of rods  148   c  have the same shape. When the support plate  148   b  has a box-shaped member, two pairs of rods are provided for stableness and similarly connected to the back surface of the support plate. One end of the rod  148   c  is rotatably attached to the support plate  148   b  via the shaft  148   d , and the other end of the rod  148   c  is rotatably attached to the cartridge  142  or a member connected to the cartridge  142  via the shaft  148   e.    
       FIG. 14A  corresponds to  FIG. 13A , and  FIG. 14B  corresponds to  FIG. 13B . When the opening/closing means (not shown) of the shutter  148  applies a force to the shutter  148  in the left direction that is the opening direction from the state shown in  FIG. 14A , the rod  148   c  rotates counterclockwise around the shaft  148   e  and the support plate  148   b  connected to the rod  148   c  at the shaft  148   d  rotates with the shutter  148  accordingly. As a result, the opening state shown in  FIG. 14B  is obtained. 
     The clamp/unclamp mechanism shown in  FIGS. 15A and 15B  utilizes a cam mechanism, and includes a pair of cam grooves  142   d  provided in the cartridge  142  or a member connected to the cartridge  142 , and a support plate  148   f  having a pair of projections  148   g  each connected to a corresponding one of the cam grooves  142   d.    
     The support plate  148   b  is connected to the shutter  148  on its top surface. In addition, the opening/closing means (not shown) of the shutter  148  is fixed onto the shutter  148  or the support plate  148   f . A pair of cam grooves  142   d  have the same shape, and include a horizontal part  142   d   1  and an arc part  142   d   2 , but may be entirely made of the arc part or curved part. The support plate  148   f  may be a plate-shaped member or a box-shaped member, similar to the support plate  148   b.    
       FIG. 15A  corresponds to  FIG. 13A , and  FIG. 15B  corresponds to  FIG. 13B . When the opening/closing means (not shown) of the shutter  148  applies a force to the shutter  148  in the left direction that is the opening direction from the state shown in  FIG. 15A , each projection  148   g  moves along the cam groove  142   d . As the projection  148   g  passes the arc part  142   d   2 , the shutter  148  gradually drops, and the opening state shown in  FIG. 15B  is finally obtained. 
     The feed system supplies the wiping member W to the top of the wiping table  149 , and rolls up and collects the dirty wiping member W. As a result, when the shutter  148  opens, an exposed part of the wiping member W above the wiping table  149  or  190  changes. The feed system includes the wiping unit controller  141 , the motor  150 , the take-up reel  152 , the guide rollers  156 , the connection shafts  158 , and a tension application mechanism. 
     The wiping unit controller  141  adjusts the tension and a feed amount of the wiping member and, if a residual amount becomes small, informs the main controller  102  of that fact. In response, the main controller  102  indicates that fact on the indicator, and displays a message that prompts a user to replace both the take-up reel  152  and the feed reel  154  or the cartridge  142 . 
     A motor shaft of the motor  150  is connected to a connection shaft  158   a , and rotates the take-up reel  152  via the connection shaft  158   a . The tension and a residual amount of the wiping member W can be detected by monitoring the torque of the motor  150  by using the torque detector  172 . In this case, the take-up diameter or the residual amount of the wiping member W and the torque of the motor  150  have a relationship shown in  FIG. 16 . The abscissa axis denotes the take-up diameter of the wiping member W in the take-up reel  152  or a residual amount of the wiping member W in the feed reel  154 . The ordinate axis denotes the torque of the motor  150  connected to the take-up reel  152 . The torque of the motor  150  increases as the take-up diameter increases or the residual amount reduces. The exchange timing can be a near-end state before the residual amount becomes 0. Since a rotation amount can be recognized by adding an encoder  170  to the motor  150 , a feed amount of the wiping member can be detected. 
     The take-up reel  152  is a reel configured to roll up the (dirty) wiping member, and has a center shaft  152   a . The feed reel  154  is a reel mounted with the clean wiping member and configured to supply it to the wiping table  149 , and has a center shaft  154   a . The guide rollers  156  support the wiping member W, and determine a feed route of the wiping member W. The guide rollers  156  may be used as part of a detector configured to detect the internal state of the cartridge  142 . 
     The connection shafts  158  are connected to or inserted into the take-up reel  152 , the feed reel  154 , and the guide rollers  156 . The connection shafts  158  include a connection shaft  158   a  connected to the shaft  152   a  of the take-up reel  152 , and a connection shaft  158   b  connected to the shaft  154   a  of the feed reel  154 . 
     The connection shaft  158   a  is connected with the motor shaft of the motor  150 , and the connection shaft  158   b  is connected with a brake plate  151   b  of the tension application mechanism, which will be described later. However, when the guide roller  156  has only a function of guiding the wiping member W, the corresponding connection shaft  158  is unnecessary. For this reason, there is no connection shaft  158  corresponding to the guide roller  156  down and to the right of the feed reel  154  shown in  FIG. 3 . On the other hand, when the guide roller  156  is part of the detection system as described in the state detection system, which will be described later, its output shaft needs to be taken out via the connection shaft  158 . For this reason, the connection shafts  158  are connected to four guide rollers  156  around the wiping table  149  shown in  FIG. 3 . 
     The wiping member W is wound around the take-up reel  152  and the feed reel  154 , for example, as shown in  FIG. 5 , and only the take-up reel  152  is a driver and the feed reel  154  and other guide rollers  156  are driven members. As the take-up reel  152  rotates in the take-up direction, the wiping member W is fed to the wiping table  149  from the feed reel  154 . 
     Referring now to  FIGS. 17A-17D , a description will be given of structures of the connection shaft  158   a , the shaft  152   a , the connection shaft  158   b , and the shaft  154   a .  FIG. 17A  is an enlarged perspective view near a connection part between the connection shaft  158   a  and the shaft  152   a .  FIG. 17B  is a plane view and an A-A sectional view of the connection shaft  158   a .  FIG. 17C  is a sectional view of the connecting shaft  158   a  inserted into the shaft  152   a .  FIG. 17D  is a sectional view of the connection shaft  158   b  inserted into the shaft  154   a.    
     The shaft  152   a  has a hollow cylindrical shape, as shown in  FIG. 17C , and includes three projections  152   b  arranged in the cylindrical direction at intervals of 120°, although the number of projections  152   b  and the interval between the projections  152   b  are not limited. 
     The projection  152   b  has a triangular prism shape, and bevel surfaces  152   c  and  152   d , which extend obliquely to a direction perpendicular to the paper plane. The bevel surface  152   c  surface-contacts a bevel surface  159   a  of the projection  159  of the connection shaft  158   a . The bevel surface  152   d  surface-contacts a bevel surface  159   b  of the projection  159  of the connection shaft  158   a , and has an inclination angle relative to a tangential direction smaller than the bevel surface  152   c . A borderline between the bevel surface  152   d  and the shaft  152   a  inclines relative to a generating line of the hollow cylinder. 
     The connection shaft  158   a  has a shape made by connecting a conical part  158   a   1  and a cylindrical part  158   a   2 , as shown in  FIGS. 17A-17C . The cylindrical part  158   a   2  has three projections  159  arranged in the circumferential direction at intervals of 120°, although the number of projections  159  and the interval between the projections  159  are not limited. 
     The projection  159  has a triangular prism shape, similar to the projection  152   b , and includes bevel surfaces  159   a  and  159   b . The bevel surface  159   a  surface-contacts the bevel surface  152   c  of the projection  152   b  of the shaft  152   a . The bevel surface  159   d  surface-contacts the bevel surface  152   d  of the projection  152   b  of the connection shaft  152   a , and has an inclination angle smaller than the bevel surface  159   a . As shown in the A-A sectional view in  FIG. 17B , a borderline between the bevel surface  159   b  and the cylindrical part  158   a   2  inclines relative to a generating line of the cylinder part  158   a   2 . 
     In connecting the cartridge  142  to the cartridge support member  144  or in attaching the take-up reel  152  to the cartridge  142 , the connection between the shafts  152   a  and the  158   b  is smooth. For example, if a gear is formed on a surface of the connection shaft  158   a  and a corresponding gear is formed on an internal surface of the shaft  152   a , the insertion becomes difficult or unable if their phases do not match at the insertion time. In particular, this is even true when the insertion causes an increase of the tension of the wiping member W. 
     In addition, similar to the connection shaft  158   a , the connection shaft  158   b  is fixed onto the brake plate  151   b , which will be described later, and does not rotate because the load M is applied to the connection shaft  158   b  by the tension adjustment mechanism  151 . Therefore, the connection shaft  158   b  and the shaft  154   a  suffer from similar problems to that for the connection shaft  158   a  and the shaft  152   a.    
     As shown in  FIGS. 17A to 17C , in the connection parts, the bevel surfaces  152   c  and  152   d  have different shapes and the bevel surfaces  159   a  and  159   b  have different shapes, allowing the take-up reel  152  to rotate in a rotating direction at the insertion time, as shown in  FIG. 17C . When this rotation direction is set to a direction in which the tension applied to the wiping member W becomes smaller or a counterclockwise direction shown in  FIG. 5 , no problem occurs such as the wiping member W is cut due to an excessive tension when the shaft  152   a  is connected to the connection shaft  158   a . As a result, attachments of the cartridge  142  and the take-up reel  152  become easier. 
     Referring now to  FIG. 5 , as the take-up reel  152  rotates clockwise, it rolls up the wiping member W; as the take-up reel  152  rotates counterclockwise, it slacks the tension of the wiping member W. On the other hand, as the feed reel  154  rotates counterclockwise, it strengthens the tension of the wiping member W; as the feed reel  154  rotates clockwise, it feeds the wiping member W. Since the slacking directions of the wiping member W are thus opposite between the take-up reel  152  and the feed reel  154 , it is necessary to form the connection part between the feed reel  154  and the connection shaft  158   b , in a direction opposite to that for the take-up reel  152 .  FIG. 17D  shows this structure. 
     On the other hand, when the motor  150  is rotated, the bevel surface  152   c  surface-contacts the bevel surface  159   a  and the driving force of the motor is transmitted to the take-up reel  152  via the connection shaft  158   a  and the shaft  152   a.    
     The structure of the connection part is not limited. For example, a connection between the shafts  152   a  and  158   a  may use a coupling or another connection means. 
     The tension application mechanism is a mechanism configured to apply a predetermined tension to the wiping member W. When no tension is applied, a slack occurs in the wiping member W due to the friction between the wiping member W and the tool surface  105 . In addition, the slack would make an infiltration of the solvent uneven. Then, average wiping of the tool surface  105  is unavailable, the life of the head  104  shortens, and its exchange frequency increases. The tension application mechanism includes, as shown in  FIG. 18 , a tension adjustment mechanism  151   a  and a brake plate  151   b.    
     The tension adjustment mechanism  151   a  is mounted on a support member  144   c  having an L-shaped section provided on the surface  144   b  of the cartridge support member  144 , and applies the load M onto the brake plate  151   b . This load M provides the tension. The tension adjustment mechanism  151   a  is made, for example, of an air cylinder. 
     The brake plate  151   b  is a disk provided on a surface  144   b  of the cartridge support member  144 , and a connection shaft  158  as one center axis projects to the surface  144   a  of the cartridge support member  144 . The connection shaft  158  is connected to the shaft  154   a  of the feed reel  154 . In  FIG. 5 , as the take-up reel  152  rotates clockwise, the feed reel  154  also rotates clockwise but the brake plate  151   b  applies the resistance smaller than the rotating force of the take-up reel  152  in the direction in which the feed reel  154  rotates. As a result, the tension corresponding to a difference between the rotating force of the take-up reel  152  and the resistance of the brake plate  151   b  can be applied to the wiping member W. 
     The tension application mechanism can eliminate the slack of the wiping member W at the wiping time, stabilize the wipe operation, surely wipe out the underfill UF, and extend the life of the head  104 . In rolling up the wiping member W, a twist or slack of the wiping member W is restrained, and wiping can be made stable. 
     In order to apply a constant tension to the wiping member W irrespective of a diameter of the wiping member W of the feed reel  154 , a residual amount detector  151   c  may be provided and the wiping unit controller  141  may adjust the load M in accordance with a change of the diameter. The tension may be adjusted by the controller other than the wiping unit controller  141 . The residual amount detector  151   c  can use the torque detector  172  and a cantilever  176 , which will be described later. 
     As shown in  FIGS. 19-20 , the state detection system detects the internal state (such as an end, a feed amount, and a residual amount of the wiping member) of the cartridge  142  having an airtight structure from the outside. The state detection system includes an output shaft that associates with the operation of the operating part of the cartridge  142 , a connection part that connects the output shaft to an external output part, the external output part provided in the cartridge support member  144 , and a detector provided in the cartridge support member  144  and configured to detect a change of the external output part. 
     For the airtight structure of the cartridge  142 , the cartridge  142  and the cover  143  are sealed by a seal  143   a . The operating part is, for example, the take-up reel  152 . The hollow shaft (output shaft)  152   a  of the take-up reel  152  is connected to the motor shaft of the motor  150  via the connection shaft  158   a . The connection part is not limited, such as a mechanical engagement using a convex and a concave or magnetic coupling. The detector comprised of a rotary encoder  170  includes an optical sensor  171   a  and a disc  171   b  for detecting a rotational angle. In  FIG. 19 , the motor  150  is omitted. 
     The airtight seal  143   a  is also provided between shaft  152   a  and the cartridge  142 , and maintains the cartridge  142  airtight. The encoder  170  may use any structure known in the art, such as an increment type or an absolute type, and a detailed description thereof will be omitted. The state detection system shown in  FIG. 19  can provide a feed amount of the wiping member corresponding to the rotation angle of the motor  150 . The state detection system comprised of the torque detector  172  can detect an end or a residual amount of the wiping member. 
     Of course, the state detection system is not limited to the encoder  170  or the torque detector  172 .  FIG. 20  uses the guide roller  156   a , the cantilever  176 , and the lever  178  for the state detection system. 
     The guide roller  156   a  rotates with a movement of the wiping member W, and a feed amount of the wiping member W can be detected by a mechanism similar to that shown in  FIG. 19 , when the guide roller  156   a  is regarded as the take-up reel  152  shown in  FIG. 19 .  FIG. 21  shows this example.  FIG. 21  is a sectional view of the state detection system corresponding to  FIG. 19 . An optical sensor  171   c  and a disc  171   d  for detecting the rotation angle correspond to the optical sensor  171   a  and the disc  171   b  for detecting the rotation angle, forming a rotary encoder. Thereby, a feed amount of the wiping member W can be maintained constant, and the cost and the exchange frequency can be saved through maximum utilization. 
     Similarly, the cantilever  176  is configured to rotate around the shaft  176   a ; it displaces to the counterclockwise side when there is a large residual amount of the wiping member W, and displaces to the clockwise side when the residual amount becomes small. When the shaft  176   a  is regarded as the take-up reel  152  shown in  FIG. 19 , a residual amount of the wiping member W can be detected by a mechanism similar to that shown in  FIG. 19 . The lever  178  is configured to rotate around the shaft  178   a , and rotates clockwise in  FIG. 19  when the wiping member W runs out. When the shaft  178   a  is regarded as the take-up reel  152  shown in  FIG. 19 , an end of the wiping member W can be detected by a mechanism similar to that shown in  FIG. 19 . 
     Thus, the state detection system maintains the inside of the cartridge  142  airtight, and prevents a leakage of any volatile solution to the outside, providing a waterproof and explosion-proof structure. In addition, since a common sensor and a common actuator are used for all cartridges  142  rather than providing a sensor and an actuator for each cartridge  142 , a variety of effects are obtained, including the cost reduction, a simpler structure, an easy exchange of the wiping member, easy maintenance and exchange of the cartridge  142 , and the reduced number of operations. 
     Referring to  FIG. 22 , a description will be given of a variation of the feed system.  FIG. 22  is a schematic sectional view showing the variation of the feed system. The feed system shown in  FIG. 22  is a mechanism of drawing the wiping member W in association with opening of the shutter  148 . Therefore, the take-up motor is also unnecessary. 
     The shaft  152   a  of the take-up reel  152  is engaged with a one-way clutch  153   a , the one-way clutch  153   a  is engaged with a pinion, and the pinion is engaged with a rack. The shutter  148  is connected to the rack via a connection rod  153   c.    
     When the shutter  148  opens in the arrow direction, the rack and the pinion  153   b  move in the arrow direction via the connection rod  153   c , and rotate the shaft  152   a  clockwise via the one-way clutch  153   a . As a result, the take-up reel  152  rotates, and the wiping member W is fed. 
     On the other hand, even when the shutter  148  closes, the one-way clutch  153   a  does not rotate the shaft  152   a . Thus, when the feed system is configured to feed the wiping member W in association with opening of the shutter  148 , the take-up mechanism of the wiping member W does not need a motor and the wiping unit becomes less expensive, smaller, and lighter. 
     Turning back to  FIGS. 1 and 3 , the solvent supply system serves to supply the solvent configured to powder the underfill UF, to the exposed part of the wiping member W on the wiping table  149 , and includes a wiping unit controller  141 , a solvent supply unit controller  160 , a solvent supply unit  162 , a joint  164 , and a tube  166 . 
     The underfill UF is generally epoxy resin, which is a viscose liquid and is unlikely to be absorbed in the cloth, etc. The solvent contains, for example, pure water or alcohol. When the underfill UF is powdered and the wiping member made of the cloth, it is likely to come into apertures in the fiber. 
     The solvent supply unit  162  stores the solvent and supplies it to the wiping member via the joint  164  and the tube  166  connected to the joint  164 . A solvent supply amount and the supply timing of the solvent supply unit  162  are controlled by the solvent supply unit controller  160 . The solvent supply unit controller  160  is controlled by the wiping unit controller  141 . 
     The ultrasonic bonding apparatus  100  further includes a mounting means (such as a robot arm) of the substrate B onto a stage of the alignment mechanism  136 , and a mounting means of the chip C onto the tool surface  105  of the head  104 . However, these mounting means are omitted in  FIG. 1 . 
     The timing control system serves to control the wiping timing, and includes a wiping unit controller  141  and a dirt state detector. 
     The wiping unit controller  141  determines, based on a detection result of the dirt state detector, whether the tool surface  105  needs wiping. Instead of the wiping unit controller  141 , the main controller  102  or another controller connected to the main controller  102  (which will be sometimes referred to as a “controller” collectively) may be used. 
     The dirt state detector detects a dirt state of the tool surface  105 , and includes one of the image pickup system, an ultrasonic amplitude variation detection system, an impedance variation detection system, a counter, and a clock. One of the ultrasonic amplitude variation detection system and the impedance variation detection system is sufficient, and the image pickup system is used instead of or together with one of them. 
     The image pickup system take an image of the back surface of the chip C mounted onto the substrate B when the substrate B is exported, detects the dirt state, and includes an image pickup unit  180 , a movement mechanism  182 , and an image processor  184 . The image pickup unit  180  includes a camera that has a field that can take an image of the back surface of the chip C. The movement mechanism  182  and the image processor  184  are similar to the movement mechanism  133  and the image process  134 , and a detailed description thereof will be omitted. 
     The ultrasonic amplitude variation detection system detects a variation of the ultrasonic amplitude, and includes the ultrasonic generator  120 . The impedance variation detection system detects a variation of the oscillation impedance, and includes the ultrasonic generator  120 . The oscillation impedance and the amplitude lower, as the underfill UF adheres to the tool surface  105  or the thickness of the underfill UF increases. 
     When the impedance is a determinant, the controller previously obtains a relationship between the impedance and the number of mounts of the chip C, as shown in  FIG. 23 . The controller determines, based on a value of the impedance obtained from the ultrasonic generator  120 , whether the dirt is bad or whether wiping is necessary. In case of the amplitude, the controller also uses a similar graph for a determination. In case of the image of the back surface of the chip, the controller previously obtains a threshold of the area of the underfill UF that adheres to the back surface of the chip, and determines that it is dirty or wiping is necessary when detecting the area of the underfill UF larger than the threshold. 
     The counter counts the number of chips C mounted without wiping. The clock measures a mounting time period of the chip C mounted without wiping. 
     Referring now to  FIG. 24 , a description will be given of an operation of the ultrasonic bonding apparatus  100 .  FIG. 24  is a flowchart for explaining an operation of the ultrasonic bonding apparatus  100 . Initially, as a pretreatment, the underfill UF is applied to the chip mounting area of the substrate B by using a dispenser (not shown) (step  1100 ). The underfill UF is applied outside of the ultrasonic bonding apparatus  100 , and shown by a broken line in  FIG. 24 . 
     In the ultrasonic bonding apparatus  100 , the substrate B is supplied to and mounted onto a three-dimensional stage of the alignment mechanism  136  by a robot arm (not shown) (step  1202 ). Next, the chip C is mounted onto the tool surface  105  of the head  104  by using a robot arm (not shown) (step  1204 ). Next, the movement mechanism controller  135  controls the movement mechanism  133  to move the image pickup unit  132  to the image pickup position (step  1206 ). Next, the positions of the substrate B and the chip C are recognized based on an image processing result by the image processor  134  by recognizing their alignment marks (step  1208 ). 
     Next, the alignment mechanism controller  131  controls the alignment mechanism  136  to move the substrate B so that both alignment marks can have a predetermined positional relationship, thereby providing an alignment between the chip C and the chip mounting area of the substrate B (step  1210 ). Next, the movement mechanism controller  135  controls the movement mechanism  133  to retreat the image pickup unit  132  (step  1212 ). Next, the press controller  110  controls the Z stage of the press mechanism  112  to move down the head  104  (step  1214 ). 
     After the chip C contacts the surface of the chip mounting area to which the underfill UF has been applied, the press controller  110  controls the Z stage of the press mechanism  112  to apply a predetermined pressure to the chip C. In addition, the press controller  110  controls the ultrasonic generator  120  to apply the predetermined ultrasonic wave to the transducer  122  (step  1216 ). As a result, the bumps N on the chip C are ultrasonically bonded with the pads of the substrate B. Next, the press controller  110  controls the Z stage of the press mechanism  112  to move up the head  104  (step  1218 ). 
     Next, the controller determines whether there is another chip to be mounted (step  1220 ). When the controller determines that there is no other chips to be mounted (step  1220 ), the controller determines whether tool surface  105  needs wiping, based on a detection result of the dirt state detector (step  1222 ). In other words, the controller compares the area of the underfill UF on the back surface of the chip photographed by the image pickup system, with the threshold stored in the memory. If the controller determines that the area is larger than the threshold, the controller determines that wiping is necessary. Alternatively, the controller compares the oscillation impedance value detected by the ultrasonic generator  120  with the threshold T of the broken line in the graph shown in  FIG. 5 . If the controller determines that the value is higher than the threshold, the controller determines that wiping is necessary. Alternatively, the controller compares the amplitude value detected by the ultrasonic generator  120  with the previously stored threshold of the graph. If the controller determines that the value is higher than the threshold, the controller determines that wiping is necessary. Alternatively, the controller obtains and compares with a threshold a value of the counter configured to count the number of chips C mounted without wiping. If the controller determines that the value is higher than the threshold, the controller determines that wiping is necessary. Alternatively, the controller obtains and compares with a threshold a value of the clock configured to measure a mounting time period of the chip C without wiping. If the controller determines that the value is higher than the threshold, the controller determines that wiping is necessary. 
     The controller exports, when determining that no wiping is necessary (step  1222 ), the substrate B mounted with the chip C by using the robot arm (not shown) from the ultrasonic bonding apparatus  100  (step  1224 ). 
     Next, as a post-treatment, the substrate B mounted with the chip C is housed in a heater (not shown) so as to heat the substrate B to cure the underfill UF. As a consequence, the electronic device  10  shown in  FIG. 2  is manufactured (step  1400 ). 
     On the other hand, when the controller determines that there is another chip to be mounted (step  1220 ), the flow returns to the step  1204 . 
     In addition, when the controller determines that wiping is necessary (step  1222 ), the controller allows the wiping unit  140  to wipe out the underfill UF (step  1300 ). Thereafter, the flow returns to the step  1204 . 
     Referring now to  FIG. 25 , a description will be given of details of the step  1300 .  FIG. 25  is a flowchart for explaining details of the step  1300 . 
     Initially, a wiping condition is set or reset in the memory of the main controller  102  or the wiping unit controller  141  or another controller (simply referred to as a “controller” hereinafter) (step  1302 ). The initial setting is made by a user from the input part but the resetting is automatically performed by the controller. The wiping condition determines the wipe operation performed by the wiping unit  140 . The wiping condition contains a wiping amplitude, a wiping time period, a solvent supply amount, and a pressure. 
     The wiping amplitude is an amplitude or width by which the drive stage  146  reciprocates or swings the cartridge  142  or the wiping table  190  in the X direction. The wiping time period is a time period used for the drive stage  146  to reciprocate or swing the cartridge  142  or the wiping table  190  in the X direction. The solvent supply amount is a supply amount of the solvent supplied by the solvent supply unit  162 . The pressure is a pressure between the tool surface  105  and the wiping member W on the wiping table  149  applied by the press mechanism  112 . 
     Next, the wiping unit controller  141  controls the drive stage  146  to move the wiping unit  140  (step  1304 ). Next, the wiping unit controller  141  controls the tension application mechanism to apply the tension to the wiping member W (step  1306 ). 
     Next, the wiping unit controller  141  controls the motor  150  to supply the wiping member W from the feed reel  154  to the top of the wiping table  149  (step  1308 ). Next, the solvent supply unit controller  160  controls the solvent supply unit  162  to supply the solvent to the exposed part of the wiping member W which exposes above the wiping table  149  via the joint  164  and the tube  166  (step  1310 ). Next, the wiping unit controller  141  opens the shutter  148  (step  1312 ). Next, the press controller  110  controls the Z stage of the press mechanism  112  to move down the head  104  (step  1314 ). 
     After the chip C mounting area and its surrounding area on the tool surface  105  contacts the wiping member W on the wiping table  149 , the press controller  110  controls the Z stage of the press mechanism  112  to apply the predetermined pressure to the tool surface  105  (step  1316 ). Next, the wiping unit controller  141  controls the drive stage  146  to swing the wiping unit  140  or the wiping table  190  in the X direction for wiping of the tool surface  105  (step  1318 ). 
     The pressure is controlled during wiping. When the press mechanism  112  continues to apply the set pressure, the wiping member W is gradually crushed during wiping. As a result, as shown in  FIG. 26A , the actual pressure gradually decreases from the set pressure (see a graph of “with no pressure control”). Therefore, it is necessary to adjust the pressure applied by the press mechanism  112  so that the pressure applied to the wiping member W can be the set pressure (see a graph of “with pressure control” in  FIG. 26A ). 
     Accordingly, the controller determines, based on the detection result of the load sensor  114 , whether the pressure during wiping is the set pressure (step  1320 ). When the controller determines that the actual pressure is the set pressure in the wiping (step  1320 ), the controller determines whether or not wiping ends (step  1322 ). The load sensor  114  may be provided to the wiping unit  140 . 
     When the controller determines that wiping is still continuing (step  1322 ), the flow returns to the step  1320 . On the other hand, when the controller determines that the pressure during wiping is not the set load (step  1320 ), the controller provides a pressure control shown in  FIG. 26B , and informs the press controller  110  of the result. In response, the press controller  110  adjusts (usually gradually increases) the pressure by the press mechanism  112 , and maintains the set pressure (step  1328 ). Thereafter, the flow returns to the step  1320 . 
     When the controller determines that wiping ends (step  1322 ), the controller controls the next solvent supply amount (step  1324 ). In other words, as described above, the wiping member W is gradually crushed during wiping, and consequently the solvent absorbing power lowers. As a solvent supply amount is excessively large, the liquid leakage occurs; as a solvent supply amount is excessively small, the wiping performance lowers. Therefore, a solvent supply amount needs to be controlled properly. 
     Accordingly, the controller stores a variation (deviation) of the pressure in the step  1328 , estimates a crush amount of the wiping member W for the same surface in the next wiping based on the stored information, and returns to the step  1302  to reset the solvent supply amount by the solvent supply unit  162  in the step  1310 . According to this control, a solvent supply amount is reduced as a crush amount of the wiping member W becomes larger. 
     Next, the press controller  110  controls the Z stage of the press mechanism  112  to move up the head  104  (step  1326 ). Next, the controller determines whether the wipe state is good, based on the detection result of the detector (step  1330 ). The detector of this embodiment is the load sensor  114  or the ultrasonic generator  120 . The load sensor  114  can detect the load in driving the cartridge  142  in the X direction when the press mechanism  112  presses the head  104  against the wiping table  149 . The ultrasonic generator  120  can detect the oscillation impedance of the head  104 . The detector may be provided to the wiping unit  140 . 
     When the controller determines that the wipe state is good (step  1330 ), the controller closes the shutter  148  (step  1332 ) and the wiping unit controller  141  controls the drive stage  146  to retreat the wiping unit  140  (step  1334 ). 
     Next, the controller determines whether the residual amount of the wiping member is sufficient, based on the detection result of the torque detector  172  or the lever  178  and information shown in  FIG. 16  stored in the memory etc. (step  1336 ). When the torque detector  172  is utilized, the step  1336  may be performed after the step  1308 . 
     When the controller determines that the residual amount of the wiping member is insufficient (such as near-end) (step  1336 ), the controller indicates a message that prompts the user to exchange the wiping member through the main controller  102  (step  1338 ). The notice to the user is not limited to an indication of the message, such as blinking of the lamp, and an alarm sound using a buzzer. 
     On the other hand, when the controller determines that the wipe state is bad (step  1330 ), the controller returns to the step  1302  to reset the wiping condition. The oscillation impedance in the ultrasonic driving increases as a layer of the uncured underfill UF becomes thinner (or is reduced). The controller estimates the wipe state of the wipe operation from the oscillation impedance variation, and resets an optimal wiping condition. For example, when the oscillation impedance or the horizontal force in the X direction reaches a preset value or higher, wiping is stopped. When the oscillation impedance or the horizontal force in the X direction is below the preset value, the wiping amplitude is increased, a pressure by the press mechanism  112  is increased, a solvent supply amount is increased, or a wiping time period is extended. 
     Further, the invention is not limited to the disclosed exemplary embodiments, and various modifications and variations may be made. For example, while the ultrasonic bonding apparatus  100  of this embodiment mounts a flip-chip, the present invention is applicable to another electronic device, such as a BGA and a CSP. 
     The present invention can provide an ultrasonic bonding apparatus configured to maintain the cleanness of a tool surface.