Patent Publication Number: US-2007123068-A1

Title: Conductive ball arraying apparatus

Description:
This application claims priority from Japanese Patent Application No. 2005-346414, filed on Nov. 30, 2005, the entire subject matter of which is incorporated herein by reference.  
     BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The present invention relates to an improvement in an apparatus for arraying conductive balls on an arraying jig such that ball cups housing the conductive balls over the arraying jig and, more particularly, to a conductive ball arraying apparatus developed by noting the movements of the ball cups.  
      2. Description of the Related Art  
      In the related art, there is a solder ball mounting apparatus for mounting the solder balls on the individual electrodes formed in a predetermined array pattern on a mounting object, after an adhesive material was applied to the electrodes. As disclosed in JP-A-2001-35845, the solder balls are mounted on the individual electrodes of the mounting object after they are sucked and arrayed on the ball mounting head having the array plate. As the product of the mounting object such as a wafer becomes larger, the number of solder balls to be mounted at one time exceeds one million, and it is the current practice to reduce the defects at the time of arraying and mounting the solder balls.  
      As disclosed in Japanese Patent No. 3,271,482, therefore, there is provided an apparatus, in which an array mask (e.g., a template in Japanese Patent No. 3,271,482) is disposed above an electronic substrate such as the mounting object having printed flux. A ball cup (e.g., a solder ball housing section) moves over the array mask and drops the solder balls directly on the electrodes of an electronic substrate. However, the conductive ball arraying apparatus of this kind is encountered by many deformations of the conductive balls and many occurrences of foreign substances.  
      In the conductive ball arraying apparatus of this kind, as shown in  FIG. 8A , solder balls  21  are pushed by a ball cup  23   a  to fall into an insert section  18 . If the solder balls  21  are pushed straight, the solder ball  21 A to be dropped is pushed straight, as shown in  FIG. 8B , by solder balls  21 B and  21 C following the solder ball  21 A, and is frequently clamped by the edge  18 A of the insert section  18  of a ball array mask  19 . By this clamping force, the solder ball  21 A becomes chipped to form fragments, or the folder ball  21 A is deformed by itself.  
      In the solder ball mounting apparatus disclosed in Japanese Patent No. 3,271,482, therefore, there has been developed means for moving a ball cup (e.g., a solder ball housing section) helically and horizontally. However, this helical movement is followed by the movement backward of the proceeding direction. This raises problems that it takes time to mount the balls, that a straight portion is formed in the movement in the proceeding direction thereby to cause the chipping of the balls, and that the transverse movement is uselessly invited by the helical movement to lower the efficiency.  
     SUMMARY OF THE INVENTION  
      The invention has an object to move ball cups zigzag so that motions oblique to the proceeding direction may be given to conductive balls, as shown in  FIG. 8C , thereby to facilitate the drops of the conductive balls while rolling into an insert section, and to make the conductive balls loose in ball cups by the zigzag motions of the ball cups so that the falling conductive balls may be clamped by the edge of the insert section of a ball array mask thereby to avoid the danger that the solder ball becomes chipped to form the foreign substance, or that the folder ball is deformed by itself.  
      In order to solve the problems, according to a first aspect of the invention, a conductive ball arraying apparatus comprising: an arraying jig having a conductive ball insert section; a ball cup having an opening in a lower face thereof and being capable of housing a plurality of conductive balls together with the arraying jig; and moving means which moves the ball cup zigzag along an upper face of the arraying jig and arrays the conductive balls.  
      According to a second aspect of the invention, the moving means moves the ball cup housing the conductive balls zigzag along the upper face of the arraying jig, falls the conductive balls from the opening of the ball cup into an insert section of the arraying jig and arrays the conductive balls.  
      According to a third aspect of the invention, the opening of the ball cup is narrower than the width of the area, and when the proceeding direction of the ball cup is turned, the moving means moves perpendicularly to the proceeding direction.  
      According to a fourth aspect of the invention, a zigzag width of the direction to intersect the proceeding direction of the ball cup is one half or less of the array pitch in the same direction as that of an insert section of the arraying jig. According to a fifth aspect of the invention a quantity of the conductive balls to be housed in the ball cup is kept within a predetermined range.  
      According to the first and second aspects of the invention, the moving means moves the ball cups zigzag. Therefore, motions oblique to the proceeding direction can be given to conductive balls thereby to facilitate the drops of the conductive balls while rolling into an insert section, and to make the conductive balls loose in ball cups by the zigzag motions of the ball cups so that the falling conductive balls can be clamped by the edge of the insert section of a ball array mask. Accordingly, the danger that the solder ball becomes chipped to form the fragments, or that the folder ball is deformed by itself can be avoided.  
      According to the third aspect of the invention, even if the opening for the ball cup is narrower than the width of the area, the moving means moves, when the proceeding direction of the ball cup is turned, perpendicularly of the proceeding direction. As a result, the solder balls can be efficiently arrayed all over the wafer.  
      According to the fourth aspect of the invention, the zigzag width of the direction to intersect the proceeding direction of the ball cup is one half or less of the array pitch in the same direction as that of an insert section of the arraying jig. As a result, the ball cup can be prevented from doubly moving to the insert section having the conductive balls inserted. Accordingly, the useless motions can be eliminated.  
      According to the fifth aspect of the invention, the quantity of the conductive balls to be housed in the ball cup is kept within a predetermined range. As a result, it is possible to eliminate the troubles that the conductive balls in the ball cup are too many to move in the lowermost layer while pushing one another and to fall into the insert section, and that the conductive balls in the ball cup are so few that they come out, thereby to improve the productivity of the conductive ball arraying apparatus. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a schematic top plan view showing the entirety of a solder ball mounting apparatus according to the embodiment;  
       FIG. 2  is a schematic top plan view showing the case, in which a wafer supply section and a wafer housing section are disposed in the same direction;  
       FIG. 3  is an explanatory view showing the movements of a wafer transfer stage;  
       FIG. 4  is a partially sectional side elevation of a ball mounting section;  
       FIG. 5  is a top plan view of the ball mounting section;  
       FIG. 6  is an explanatory view showing the movement of a ball cup;  
       FIG. 7  is an explanatory view of the zigzag width in a direction to intersect the proceeding direction of the ball cup; and  
       FIGS. 8A  to  8 C are explanatory views showing relations between solder balls and an insert section: (A) an explanatory section; (B) an explanatory top plan view of the case, in which the solder balls are pushed straight; and (C) an explanatory top plan view of the case, in which the solder balls are pushed obliquely. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
      The invention is described in the following in connection with its embodiment with reference to the accompanying drawings. In the invention, an object, on which conductive balls are to be mounted, is exemplified by a semiconductor wafer (as will be merely called as the “wafer”), an electronic circuit substrate or a ceramic substrate, but the embodiment uses a wafer  14 . On the other hand, an adhesive material is exemplified by flux, solder paste or a conductive adhesive, but the embodiment uses the flux.  
       FIG. 1  is a schematic top plan view showing the entirety of a solder ball mounting apparatus  1 . The solder ball mounting apparatus  1  includes a carry-in wafer transfer section  2 , a flux printing section  3 , a ball mounting section  4  and a carry-out wafer transfer section  5 , as recited in the order from the left-hand side of  FIG. 1 . A wafer supply section  6 , a primary alignment section  7  and a carry-in robot  8  exist at the pretreatment of the solder ball mounting apparatus  1 . An inverting unit  9 , a wafer housing section  10  and a carry-out robot  11  exist at the post-treatment.  
      The primary alignment section  7  of the pretreatment rotates the wafer  14  in a horizontal plane so that it detects the position of the orientation flat or notch of the wafer  1  thereby to correct the rough position of the wafer  14  and to set the wafer  14  in the wafer transfer section in a predetermined direction. On the other hand, the inverting unit  9  of the post-treatment rotates the wafer  14  in the horizontal direction so that it rotates the orientation flat and the notch of the wafer  14  to a predetermined position thereby to house them in a cassette  32 .  
      A wafer transfer stage  12  and a transfer passage  13  which transfers the wafer  14  from the wafer transfer section  2  to the flux printing section  3 , the ball mounting section  4  and the wafer transfer section  5  are formed in the solder ball mounting apparatus  1 . The transfer passage  13  is equipped, as shown in  FIG. 3 , with an X-axis (rightward and leftward, as shown) moving device  40  of the transfer stage  12 , as shown in  FIG. 3 .  
      The flux printing section  3  has a flux supply device  16 , a printing mask  15  for printing a flux or an adhesive material on the wafer  14 , and vertical observation cameras  31  for observing the alignment marks of the wafer  14  and the printing mask  15  thereby to position the wafer  14  and the printing mask, as shown in  FIG. 3 . The printing mask  15  has a through hole formed and arrayed to the pattern of the electrodes on the wafer  14 . Alignment marks (although not shown) are displayed at two portions on the lower face of the printing mask  15  in a through hole forming area  38  and are adhered to a mold  17  and held in a stationary portion such as the frame.  
      The flux supply device  16  moves the squeegee (although not shown) along the upper face of the printing mask  15  so that the flux is printed in the through holes of the printing mask  15  and fed to the electrodes of the wafer  14 . Here, numeral  33  designates a cleaning unit for removing the flux from the printing mask  15 .  
      The ball mounting section  4  has a solder ball supply device  20 , an insert section  18  (as shown in  FIG. 4  and  FIG. 7 ) arrayed to the pattern of the electrodes on the wafer  14 , a ball array mask  19  as a plurality of arraying jigs, and vertical observation cameras  34  (as shown in  FIG. 3 ) for observing and positioning the wafer  14  and the alignment marks of the ball array mask  19 .  
      The thickness of the ball array mask  19  is substantially equal to the diameter of solder balls  21 , and the diameter of the insert section  18  is made slightly larger than that of the solder balls. The transverse array pitch P of the insert section  18  of the ball array mask  19  is generally about twice as large as the hole diameter d of the insert section  18 , as shown in  FIG. 7 . As in the printing mask  15 , two alignment marks (not-shown) are formed on the lower face in an insert section forming area  36  in the ball array mask  19 . The ball array mask  19  is adhered to a mold  37  and is fixed on the stationary portion such as the frame.  
      As shown in  FIG. 4 , the solder ball supply device  20  has a ball hopper  22  for reserving a number of solder balls  21 , ball cups  23   a  and  23   b  for dropping the solder balls  21  onto the ball array mask  19 , ball cup moving means  24  for moving the ball cups  23   a  and  23   b  in the X-axis direction and in Y-axis direction as shown in  FIG. 5 , and lifting means  45  for moving the ball cups  23   a  and  23   b  in the Z-axis direction.  
      The ball cups  23   a  and  23   b  are formed to have rectangular openings  63  in the upper portions for supplying the balls, and rectangular openings  64  in the lower face for dropping the balls. The ball cups  23   a  and  23   b  have their inner walls formed to converge toward the openings  64 .  
      The ball cup moving means  24  acting as the means for moving these ball cups  23   a  and  23   b  in the horizontal plane has an X-axis drive mechanism  25  and a Y-axis drive mechanism  26  as shown in  FIG. 5 . The X-axis drive mechanism  25  moves a base member  58 , in which the ball cups  23   a  and  23   b  are provided, through the lifting means  45  along an X-axis guide  56  in the X-axis direction by a threaded bar  55  rotated by an X-axis drive motor  54 . The Y-axis drive mechanism  26  moves the base member  58  together with the X-axis drive mechanism  25 , along a Y-axis guide  57  in the X-axis direction by a threaded bar  53  rotating the base member  58  together with the X-axis drive mechanism  25  by a Y-axis drive motor  52 . Specifically, the ball cups  23   a  and  23   b  are moved zigzag in the Y-axis direction as indicated by arrows in  FIGS. 5 and 6 , by associating the Y-axis drive mechanism  26  and the X-axis drive mechanism  25 . The movements are returned in the Y-axis direction to repeat the actions to move zigzag in the Y-axis direction, so that the solder balls  21  are dropped and fitted in the insert section  18  of the ball array mask  19 . By thus moving the ball cups  23   a  and  23   b  zigzag, the ball cups  23   a  and  23   b  are always move obliquely forward with respect to the inner wall faces of the ball cups  23   a  and  23   b  to push the solder balls  21 , so that the solder balls  21  become easy to fall down into the insert section  18 . Here, the width W, as taken in the direction to intersect the forward direction of the ball cups  23   a  and  23   b  in the zigzag movement is one half of or less than the array pitch P of the insert section  18 , as taken in the same direction in  FIG. 7 .  
      The ball cups  23   a  and  23   b  are provided in parallel with each other in a transverse direction (in a direction of the X-axis) as shown in  FIG. 5 . The ball cups  23   a  and  23   b  are attached to the common mounting base  41  thereby to cover the whole mounting area. Thus, the productivity is improved by covering the whole area of the wafer  14  with the two ball cups  23   a  and  23   b . Here, these ball cups  23   a  and  23   b  may be made wider than the insert section forming area  36 . In this case, the X-axis drive mechanism  25  need not be provided but may be reciprocated in the Y-axis direction.  
      In the lifting means  45  for the ball cups  23   a  and  23   b , the mounting base  41  is mounted through a nut member  44  on a threaded bar  51  which is rotated by an Z-axis drive motor  50  belonging to the base member  58  of the ball cup moving means  24 , as shown in  FIG. 4 , so that the mounting base  41  can moved upward and downward along a guide rail  43 . The ball cup  23   a  is attached to the mounting base  41  through an inclination adjusting mechanism  42  for adjusting the mounting inclination of the ball cup  23   a . Here, the ball cups  23   a  and  23   b  are inclined when they are assembled.  
      The ball hopper is provided above the ball supply openings  63  of the ball cups  23   a  and  23   b . The ball hopper  22  reserves a number of solder balls  21  in its internal space. The ball hopper  22  has a supply port for discharging the reserved solder balls  21  to the ball cups  23   a  and  23   b , and a shutter  65  acting as open/close means for opening/closing the supply port. The ball hopper  22  is attached to the mounting base  41  shared by the ball cups  23   a  and  23   b . Numeral  66  designates a cylinder for actuating the shutter  65 . Here, the ball hopper  22  is replaced by another according to the sizes and materials of the solder balls  21 .  
      A receiving portion  67  having a ball detecting mechanism, a switching portion  68  for switching the supply of the balls to the left and right ball cups  23   a  and  23   b , and a ball introduction portion  69  for introducing the solder balls  21  into the ball cups  23   a  and  23   b  are provided below the ball supply port of the ball hopper  22 . A ball detection sensor  70 , which is provided in the receiving portion  67 , detects the supply and the clogging of the solder balls  21  supplied from the ball supply port of the ball hopper  22  and is exemplified in the embodiment by a flooding/receiving type sensor. The switching portion  68  is rocked by a rocking type air cylinder  71  thereby to share the solder balls  21  from the receiving portion  67  to the left and right ball cups  23   a  and  23   b  through the ball introduction portions  69 .  
      The ball supplying action comes in when the shutter  65  of the ball hopper  22  is opened. The ball supply timing for the action of the shutter  65  is determined in advance from the solder ball array number. The ball supply is predetermined for the ball supply time when the shutter  65  is opened. Here, the contents of the solder balls  21  in the ball cups  23   a  and  23   b  are grasped from the ball supply from the ball hopper  22  and the ball discharge from and according to the ball cups  23   a  and  23   b , and the optimum contents of the solder balls in the ball cups  23   a  and  23   b  are determined in advance.  
      The ball supplying action is performed in the following manners. At first, the vacuum in the ball hopper  22  is turned ON. Then, the shutter  65  is opened. Next, the vacuum in the ball hopper  22  is turned OFF so that the solder balls  21  in the ball hopper  22  fall from the supply port into the receiving portion  67 . At this time, the solder balls  21  having fallen into the receiving portion  67  are detected by the ball detection sensor  70 . After lapse of a predetermined time period, the vacuum in the ball hopper  22  is turned ON to stop the drop of solder balls  21 , and the shutter  65  is closed to turn OFF the vacuum.  
      The solder balls  21  having fallen into the receiving portion  67  are supplied through the switching portion  68  and the ball introduction portion  69  into one ball cup  23   a . When the supply to one is completed, the ball cups  23   a  and  23   b  to be supplied are switched. Then, the rocking type air cylinder  71  is activated to switch the introduction direction of the switching portion  68  thereby to complete the preparation for the ball supply to the other ball cup  23   b.    
      Here, the ball supplying action is repeated again to supply the balls to the other ball cup  23   b . The actions thus far described are repeated to perform the ball supply finely. This ball supplying action may be performed by stopping the ball cups  23   a  and  23   b  but can also be performed while moving the same.  
      The mask height detection sensor  27  is attached to the vicinity of the ball cups  23   a  and  23   b  and may be either of contact type or of noncontact type. The mask height detection sensor  27  is exemplified by a laser sensor or an electrostatic capacitive sensor. The mask height detection is performed at the time when the ball array mask  19  is changed at the initial setting time or at the mold changing type and after the mold  37  of the ball array mask  19  is fixed at the support portion on the frame side. Specifically, after the ball array mask  19  was fixed, the ball cups  23   a  and  23   b  in the empty state of the solder balls  21  are sequentially moved over a plurality of (or four in the embodiment) height detection points preset outside of the insert section forming area  36 , and the height of the upper face of the ball array mask  19  is measured. Incidentally, the measurements are not limited to the four detection points but may be continuously performed during the movement of the mask height detection sensor  27 , as accompanying the movement of the ball cups  23   a  and  23   b.    
      On the other hand, the height of the upper face of the ball array mask  19  in the insert section forming area  36  is determined by calculations. Moreover, the heights at the individual positions are calculated by considering the weights, which are applied to the ball cups  23   a  and  23   b  when the solder balls  21  are contained. At the ball mounting time, the ball cups  23   a  and  23   b  are moved in the X-axis direction and in the Y-axis direction such that their vertical movements are so controlled by the lifting means  45  that the clearance between the upper face of the ball array mask  19  and the lower faces of the ball cups  23   a  and  23   b  may not exceed a predetermined distance.  
      The wafer transfer stage  12 , which carries the wafer  14  thereon, and is so mounted on the transfer passage  13  as to move in the X-axis direction. As shown in  FIG. 3 , the wafer transfer stage  12  has a Y-axis drive mechanism  28  acting as moving means of a direction (or a Y-axis direction) perpendicular to the transfer direction of the wafer  14 , a θ-axis drive mechanism  29  or rotating means, and a Z-axis drive mechanism  30  or vertical moving means.  
      The actions of the solder ball mounting apparatus  1  of the embodiment are described in the following with reference to the accompanying drawings. First of all, the wafer  14  mounting the solder balls  21  is housed in the cassette  32  of the wafer supply section  6 . Thus, one wafer  14  is extracted from the cassette  32  of the wafer supply section  6  and carried in the primary alignment section  7  by the carry-in robot  8 . In the primary alignment section  7 , the wafer  14  is rotated to detect the position of the orientation flat or notch thereby to correct the position of the wafer  14  roughly and to set the orientation flat or not at a predetermined position. Subsequently, the wafer  14  is carried by the carry-in robot  8  from the primary alignment section  7  to the wafer transfer stage  12  standby at the wafer transfer station  2 .  
      The wafer transfer stage  12  carrying the wafer  14  is moved along the transfer passage  13  to the flux printing section  3  and stops at a predetermined position. Here, the alignment marks of the wafer  14  and the printing mask  15  are individually observed by the vertical observation cameras  31  so that the wafer transfer stage  12  is positioned in the X-axis direction by the X-axis drive mechanism  40  of the transfer passage  13 , in the Y-axis direction by the Y-axis drive mechanism  28  and in the θ-axis direction by the θ-axis drive mechanism  29 . After positioned, the wafer transfer state  12  is raised by the Z-axis drive mechanism  30  and stops at a predetermined height position with respect to the printing mask  15  prepared with the flux. In this state, the flux is fed to one end portion of the printing mask  15  in the Y-axis direction, and the squeegee is moved from one end portion to the other of the Y-axis direction so that the flux is printed from the through holes of the printing mask  15  onto the electrodes of the wafer  14 .  
      After the flux printing action, the wafer transfer stage  12  is moved downward by the Z-axis drive mechanism  30 , is moved to the ball mounting section  4  by the transfer passage  13  and stops at a predetermined position. At this position, the alignment marks of the wafer  14  and the ball array mask  19  are individually observed by the vertical observation camera  34  so that the wafer transfer stage  12  is positioned in the X-axis direction by the X-axis drive mechanism  40  of the transfer passage  13  and in the Y-axis direction and in the θ-axis direction by the Y-axis drive mechanism  28  and the θ-axis drive mechanism  29 . After this, the wafer transfer stage  12  is raised by the Z-axis drive mechanism  30  and is stopped with leaving such a clearance between itself and the ball array mask  19  that the flux printed on the wafer  14  does not stick to the ball array mask  19 .  
      Till then, the solder ball supply device  20  has positioned the ball cups  23   a  and  23   b  outside of the insert section forming area  36  of the ball array mask  19  and has housed the solder balls  21  in a predetermined amount in the ball cups  23   a  and  23   b . When the wafer  14  is set below the ball array mask  19 , the ball cups  23   a  and  23   b  are moved zigzag in the Y-axis direction over the ball array mask  19 , and the solder balls  21  are dropped into the insert section  18  of the ball array mask  19  so that they are carried on the wafer  14 . The ball cups  23   a  and  23   b  then perform the reciprocating motions, in which they move a predetermined stroke in the X-axis direction and then return in the Y-axis direction. The movement of the predetermined stroke in the X-axis direction is performed by an overrun of a distance from the position in the X-axis direction of the next ones of the solder balls  21  to be dropped into the ball cups  23   a  and  23   b  by one quarter or half of the cup width of the ball cup  23   a , and by returning the ball cups  23   a  and  23   b  to the portion of the ball array mask  19  to drop the solder balls  21 . In this meanwhile, the solder balls  21  are so supplied from the ball hopper  22  to the ball cups  23   a  and  23   b  that their quantity may be kept within a predetermined optimum range.  
      The supply of the solder balls  21  to the ball cups  23   a  and  23   b  is performed by the ball hopper  22 . However, the ball array mask  19  is arranged while leaving such a clearance that the flux balls printed on the wafer  14  may not stick to the ball array mask  19 . Therefore, it often occurs that the solder balls  21  do not fall if they are excessive in the ball cups  23   a  and  23   b . In addition, the ball array mask  19  warps so much that the flux dangerously sticks or that the solder balls  21  become hard to fall for various causes. Thus, the solder balls  21  are diligently supplied to the minimum necessary number.  
      The solder balls  21  in the insert section  18  are positionally corrected after dropped, by moving the ball array mask  19  finely in the horizontal direction (i.e., in the X-axis direction and in the Y-axis direction) with respect to the wafer transfer state  12 .  
      After having mounted the solder balls, the wafer transfer stage  12  is lowered, is moved to the delivery wafer transfer section  6  and is stopped by the Z-axis drive mechanism  30 . In the wafer housing section  10 , the wafer  14  is transferred from the wafer transfer stage  12  to the inverting unit  9  by the carry-out robot  11  and is turned so that the orientation flat or notch may come to the predetermined position. Moreover, the wafer  14  is transferred by the carry-out robot  11  from the inverting unit  9  to the cassette  32  of the wafer housing section  10 . When the carry-out robot  11  extracts the wafer  14  from the wafer transfer stage  12 , the wafer transfer stage  12  returns to the wafer transfer section  2  and ends one process. The present apparatus repeats the actions thus far described.  
      In the embodiment shown in  FIG. 1 , the wafer supply section  6  is disposed in front of the solder ball mounting apparatus  1 , and the wafer housing section  10  is disposed at the back. The wafer transfer stage  12  returns to the original position. Therefore, as shown in  FIG. 2 , the wafer supply section  6  and the wafer housing section  10  may be disposed in the common direction, as shown in  FIG. 2   
      According thereto, the carry-out robot  11  can be substituted for by the carry-in robot  8 , and the wafer  4  is held and housed in the same direction as that of the wafer  14  being carried in, so that the inverting unit  9  can be omitted. In addition, one of the wafer transfer units  2  and  5  can be omitted to reduce the number of components.  
      Moreover, the means for positioning the printing mask  15 , the ball array mask  19  and the wafer  14  is exemplified by the vertical observation cameras  31  and  34  for photographing the alignment mark of the wafer  14  and the printing mask  15  or the ball array mask  19  when the wafer transfer stage stops. However, the invention should not be limited thereto, but various structures can be conceived.  
      In this embodiment, the solder balls  21  are directly mounted on the electrodes on the upper face of the wafer  14 , and the insert section  18  becomes the ball inserting section. In the invention, the solder balls  21  are once arrayed on the arraying jig having the ball housing recesses and are sucked from the arraying jig by the solder ball sucking head so that the solder balls  21  can be transferred to the object such as the electrodes on the wafer  14 . In this case, the ball housing recesses are the ball inserting section.