Abstract:
A capillary tube for a solder ball connection device connects a first connection surface of a pad to a second connection surface of a pad with a solder ball. The first connection surface is formed at a slider held by a slider holder in a disk unit. The second connection surface is formed at an end of a lead wired to the slider holder. The capillary tube has a ball regulator with a substantially conic, hollow portion. The solder ball regulator has an opening at its top that opens to the tip of the hollow portion. The center axes of the hollow portion and the opening are common. The solder ball regulator also has a pair of projections along the center axis around the opening, where the projections face each other with the center axis therebetween. The projections regulate the movement of the solder ball. The tip of the hollow portion is tapered when viewed from a line connecting the pair of projections and the extreme tips of the tapered tip portions.

Description:
TECHNICAL FIELD 
     The present invention relates to a solder ball connection device for connecting a bonding pad formed at a slider provided with a head, and a lead pad formed at the tip of a lead wire. More particularly, the present invention relates to a tube employed for the solder ball connection apparatus and used to position and hold a solder ball in a solder reflowing process. 
     DESCRIPTION OF THE RELATED ART 
     FIG. 8 shows a perspective view of the HG assembly suitable for electrical connection between a lead wire and a slider with use of a solder ball connection method. FIG. 9 is an expanded view of the tip of the HG assembly. The external shape of the HG assembly  100  is defined by an actuator arm  101  provided with an opening  102  and a load beam  104  extended in the longitudinal direction of the actuator arm  101  from an intermediate portion of its flat portion  103 . The actuator arm  101  and the load beam  104  are bonded together at a portion where they are placed on top of each other. 
     The opening  102  is used so that the HG assembly  100  is held rotationally by a holder of a magnetic disk apparatus (not shown). The HG assembly  100 , passing through the center of the opening, is rotated in the directions A and B around a virtual axis  150  substantially perpendicular to the flat portion  103 . A mount plate  105  is bonded to the load beam  104  substantially in the center portion so as to be put thereon. A flexure  106  is also disposed on the load beam  104  between the center and the tip thereof. This flexure  106  is bonded to the load beam  104  by a half located at the side of the mount plate  105 . The other half of the flexure  106  located at the side of the tip is not bonded to the load beam  104 . 
     As shown in FIG. 9, at the tip of the flexure  106  is formed an arch-shaped opening  107  and the slider  109  is bonded fixedly to a flexure tang  106   a  (FIG. 10) formed so as to be protruded to the center of the arch-shaped opening  107  from a platform  108  formed at the extreme tip of the flexure  106 . This flexure tang  106   a  is supported by a pivot  104   a  (shown with a broken line in FIG. 10) protruded from the load beam  104  at one point corresponding to the center of the slider  109 . Consequently, the slider  109  can be inclined at a predetermined angle (often referred to as a pitch, a roll, or a yaw) in every direction with respect to the load beam  104 . 
     Four leads  110  to  113  are wired partially to an extended portion  105   a  of the mount plate  105 . They are fixed at the extended portion  105   a  with an insulating sheet therebetween respectively so as not to touch each other. At one ends, they compose a multi-connector  114 . The four leads  110  to  113  are connected to the mount plate  105  and the flexure  106  respectively as shown in FIG.  8  and fixed so as not to touch each another with an insulating sheet therebetween respectively. The other ends of the leads are floated in the arch-shaped opening  107  as shown in FIG.  9  and they are paired, crank-bent, and led to the platform  108 . 
     The paired leads are bent substantially perpendicular to the front surface  109   a  of the slider  109  through two openings  114  and  115  formed between the platform  108  and the flexure tang  106   a  (FIG.  10 ). In addition, the lead pads  110   a  to  113   a  are formed corresponding to the connection surfaces of the four bonding pads  116  to  119  formed at this front surface  109   a . The four leads  110  to  113  are fixed to the platform  108  around their tips with an insulating sheet  20  therebetween respectively. A part of the HG assembly, where the slider  109  does not exist, is equivalent to the slider holder. 
     The following is a description of a solder ball connection method for connecting the four bonding pads  116  to  119  to the lead pads  110   a  to  113   a  formed so as to be corresponded to those bonding pads  116  to  119 . 
     FIG. 10 is a sectional view of the major portion of the HG assembly from the direction C at a directing line  151 . The directing line  151  passes the center of the bonding pad  118  shown in FIG.  9 . FIG. 10 also shows a partial cross sectional view of the solder ball connection device. The load beam  104  is not illustrated here so as to simplify the description, but the position of the pivot  104   a  formed at the load beam  104  is shown with a broken line. 
     When carrying out a solder ball connection, the inclined HG assembly  100  (FIG. 8) is held by a holder (not shown) so that the pad connection surface  118   a  of the bonding pad  118  and the connection surface  112   b  of the lead pad  112   a  face each other substantially perpendicular and each of those connection surfaces  118   a  and  112   b  is inclined substantially at 45° in the direction in which its gravity works. 
     On the other hand, the capillary tube  121  composes a part of the solder ball connection device (not shown). The capillary tube  121  is disposed in the direction in which the center axis  152  of the cylindrical inner hollow portion  121   a  can use the gravity, that is, at a position where the tip of the capillary tube  121  comes close to both of the bonding pad  118  and the lead pad  112   a  while being inclined at about 45° to the connection surface  112   b  of the lead pad  112   a.    
     The solder ball connection device (not shown) stores many solder balls  122  and sends one solder ball  122  to the tip of the capillary tube  121  through its inner hollow portion  121   a  after the capillary tube  121  is disposed at a predetermined position. At this time, the apparatus supplies a nitrogen gas (N 2 ) in the direction of the arrow a so as to prompt the solder ball  122  to move together with the action of the gravity. In addition, the nitrogen gas also presses the solder ball  122  slightly that is in contact with both connection surfaces  118   a  and  112   b  of the bonding pad  118  and the lead pad  112   a  when the solder ball  122  exists at the tip of the capillary tube  121 . 
     In this state, the solder ball connection device (not shown) applies a laser beam (shown with a broken line LZ in FIG. 10) to the solder ball  122  through the inner hollow portion  121   a  of the capillary tube  121  so as to make the solder ball reflow. The solder ball  122  is then melted in this reflowing, getting both connection surfaces  118   a  and  112   b  of the bonding pad  118  and the lead pad  112   a  wet and connected together. The nitrogen gas supplied at this time presses the melted solder against each connection surface and cover the solder so as to be prevented from oxidation. 
     This completes the description of the solder ball connection for the bonding pad  118  of the slider  109  and the lead pad  112   a  of the lead  112 . The same procedure can also apply to the connections of other three pads only by changing each position to which the capillary tube  121  is provided. 
     FIG. 11 is a perspective view of the tip shape of the capillary tube  121 . The conic tip of the capillary tube is cut as shown in FIG. 11 so that its cross section perpendicular to the center axis  152  is formed like a ring. In this case, as shown in FIG. 10, it is difficult to move the tip of the capillary tube  121  down up to the regulation point P 1  orthogonal to the center line  152  through the center of the solder ball  122 , which is in contact with both pads. This is because the tip of the capillary tube  121  comes in contact with any of the pads before reaching the regulation point P 1 , thereby its up and down movement is disturbed by the pad. 
     If the tip of the capillary tube  121  does not reach the regulation point P 1  as described above, the solder ball  122  can take an idle width at which the solder ball  122  can move in the direction parallel to both connection surfaces  118   a  and  112   b  of the bonding pad  118  and the lead pad  112 , that is, in the direction passing through the paper with FIG.  10 . Consequently, the solder ball  122  comes to reflow the solder ball in an unstable state, thereby the soldering position cannot be decided accurately or a connection failure occurs due to uneven irradiation of the laser beam on the solder ball. Furthermore, as shown in FIG. 10, the laser beam, which passes the inner hollow portion  121   a  of the capillary tube  121  so as to reflow the solder ball, hits and reflects here and there on the inner wall of the hollow portion  121   a  until it reaches the solder ball. The energy of the laser beam is thus attenuated due to such reflections, thereby the irradiation efficiency of the laser beam is lowered. To compensate such an attenuation, therefore, the output of the laser beam has been increased as much. 
     Under such a circumstances, it is an object of the present invention to provide a method for positioning a solder ball to reflow accurately and stabilize the soldering point so as to make the connection perfect, thereby preventing connection failures. It is another object of the present invention to provide a method for making solder ball connection more efficient by reducing the energy loss caused by reflections of the laser beam, thereby reducing the energy loss of the laser beam when in solder reflowing. 
     SUMMARY OF THE INVENTION 
     A capillary tube is employed for a solder ball connection device for connecting a first connection surface of a pad to a second connection surface of a pad with use of a solder ball. The pad has the first connection surface formed at a slider held by a slider holder in a disk unit. The pad has the second connection surface formed at an end of a lead wired to the slider holder. The capillary tube has a ball regulator provided with a substantially conic and hollow portion inside. The solder ball regulator has an opening at its top. The opening opens to the tip of the hollow portion. The center axis of the hollow portion is common to the center axis of the opening. The solder ball regulator also has a pair of projections protruded along the center axis at a position around the opening, where those projections face each other with the center axis therebetween. These projections regulate the movement of the solder ball. 
     The tip of the hollow portion is tapered when viewing it from the direction of a line connecting the pair of projections and the extreme tips of the tapered tip portions to each other may be used as the projections. The tip may also be formed by a pair of flat surfaces inclined to a datum level including a line connecting the center axis and the pair of projections to each other. The pair of flat surfaces may have the same angle respectively to the datum level and the pair of projections may be symmetrical to the datum level. 
     In another configuration, the capillary tube is connected to the other side end of the tip portion of the solder ball regulator and formed on the same axis as that of the solder ball regulator. The capillary tube has a cylindrical portion provided with a hollow portion continued to the hollow portion of the solder ball regulator from the viewpoint of space. Furthermore, the inside surfaces of the pair of projections may be a part of a cylindrical surface formed on the same axis as that of the hollow portion respectively. 
     In still another configuration, the inside surface of the solder ball regulator is polished like a mirror. 
     In still another configuration, the solder ball regulator and the cylindrical portion, or at least the solder ball regulator, are composed of a first tube-like body and at least a part of the cylindrical tube is composed of a second tube-like body. And, the capillary tube is further provided with a connector for connecting the first and second tube-like bodies to each other. 
     In still another configuration, the tip portion of the capillary tube is formed with a pair of first flat portions and a pair of second flat surfaces. The pair of the first flat surfaces are inclined by a first angle to the datum level including a line connecting the center axis and the pair of projections and the pair of the second flat surfaces are continued to the pair of the first flat surfaces and inclined by a second angle to the datum level. 
     The solder ball connection device, which is another invention, is provided with a capillary tube described in claim  1 ; a solder ball reservoir for supplying a solder ball into the capillary tube, the diameter of the solder ball being smaller than the inner diameter of the opening; and a laser output device for applying a focused laser beam to the opening of the capillary tube through the hollow portion. The datum level including a line connecting the center axis, as well as the first and second projections of the capillary tube is set so as to be inclined to the first and second connection surfaces, thereby the solder ball is reflowed. 
     In another configuration, the solder ball connection device is provided with a capillary tube described in claim  4 ; a solder ball reservoir for supplying a solder ball into the capillary tube, the diameter of the solder ball being smaller than the inner diameter of the opening; and a laser output device for applying a focused laser beam to the opening of the capillary tube through the hollow portion. The datum level including a line connecting the center axis, as well as the first and second projections of the capillary tube is set so as to be inclined by 45° to the first and second connection surfaces, thereby the solder ball is reflowed. 
     Furthermore, the solder ball connection device is further provided with a nitrogen gas supplier for supplying a nitrogen gas into the capillary tube. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a schematic view of a solder ball connection device in which a capillary tube is installed in an embodiment of the present invention; 
     FIG. 2 is a perspective view of a conic portion  6   a  of an action tube  6 , which is a component of the capillary tube  4  in the embodiment of the present invention; 
     FIGS.  3 ( a ) and  3 ( b ) are sectional views of the conic portion  6   a  of the action tube  6 ; 
     FIG. 4 is a sectional view showing a positional relationship among the conic portion  6   a , a bonding pad  118 , and a lead pad  112   a  for a solder ball connection with use of the capillary tube  4  of the present invention; 
     FIG. 5 is a sectional view showing a route of a focused laser beam to a ball holding opening  6   b , the focused laser beam advancing while reflecting on the inner wall  6   j  of the conic portion; 
     FIG. 6 is a sectional view showing a positional relationship among liquefied solder  11 , and tip ridge lines  6   c  and  6   d;    
     FIG. 7 is a sectional view of the capillary tube in another embodiment of the present invention; 
     FIG. 8 is a perspective view of a conventional HG assembly; 
     FIG. 9 is a partially expanded view of the tip of the HG assembly of FIG. 8; 
     FIG. 10 is a sectional view of a solder ball connection device and a portion of the HG assembly of FIG. 9 along the line  151  through the center of bonding pad  118 , the portion being viewed from the direction C; and 
     FIG. 11 is a perspective view of a tip shape of a conventional capillary tube. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIG. 1 is a schematic view of one embodiment of a capillary tube and a solder ball connection device in which the capillary tube is installed. An optical system  2  provided in the solder ball connection device  1  receives a laser light oscillated by a laser generator (not shown) through optical fiber  3  and obtains a laser beam through an optical system for focusing the laser light. The optical system  2  then outputs the laser beam into the hollow portion of the capillary tube  4  through a laser beam path  7   a  of a solder ball reservoir  7 . 
     The capillary tube  4  is composed of a hollow cylindrical tube  5  attached to the solder ball reservoir  7 ; an action tube  6  provided continuously to the tip of the hollow cylindrical tube having a tapered conic portion  6   a ; and a connection tube  12  for connecting the cylindrical tube  5  to the action tube  6 . The capillary tube  4  also has a cylindrical portion  4   a  having an inner diameter ‘a’ and a conic portion  4   b  inside. The conic portion  4   b  is formed in the action tube  6  so as to be continued to the cylindrical portion  4   a . At the tip of the action tube  6  is formed an opening  6   b  for holding a solder ball. The ball holding opening  6   b  has an inner diameter ‘b’ (FIG. 3) and it is communicated with the inner conic portion  4   b.    
     A part of the capillary tube  4 , where the cylindrical portion  4   a  having inner diameter a exists, is formed cylindrically and another part inside the capillary tube  4 , where the conic portion  4   b  exists, is equivalent to the solder ball regulator described above. And, the action tube  6  is equivalent to the first tube body provided with a solder ball regulator and the cylindrical tube  5  is equivalent to the second tube body provided with a cylindrical portion. Furthermore, the connection tube  12  is equivalent to the connector for connecting those portions each other as described above. 
     In the solder ball reservoir  7  are formed a laser beam path  7   a  connecting the optical system  2  to the hollow portion inside the capillary tube  4 ; a solder ball storage  7   b  for storing a plurality of solder balls  122 ; a solder ball singulation disk  7   c  held rotationally by itself in the solder ball reservoir  7  by driving means (not shown); an intake pipe  7   d  for taking in nitrogen gas (N 2 ) from a nitrogen gas bomb (not shown) through a tube  9 ; and a gas path  7   e  for feeding the taken-in nitrogen gas into the laser beam path  7   a.    
     The solder ball singulation disk  7   c  has a plurality of solder ball storing halls  7   f  formed by a predetermined number, disposed at equal pitches on the outer periphery of a predetermined radius from the center of the rotation. A solder ball  122  is fallen and stored in the solder ball storage  7   b  when one of the ball storing halls  7   f  is aligned to a hole (not shown) formed at the bottom of the solder ball storage  7   b . And, when the solder ball singulation disk  7   c  is rotated and a solder ball storing hall  7   f  having a solder ball inside is moved into the gas path  7   e , the solder ball  122  falls naturally and it is prompted to be fed into the capillary tube  4  by the nitrogen gas flowing in the direction of the arrow in the gas path  7   e.    
     At this time, another solder ball storing hole  7   f  formed in the ball transfer tray  7   c  is configured so as to move to a position of being brought into line with the hole (not shown) formed at the bottom of the solder ball storage  7   b . Each time the solder ball singulation disk  7   c  is rotated by a predetermined angle at a timing to be described later, the above described ball transfer operation is repeated, thereby one solder ball  122  is fed into the capillary tube  4 . 
     Inside the capillary tube  4  is formed a path used both for falling the solder ball  122  and for passing the focused laser beam  10 . Consequently, the inner diameter a of the cylindrical portion  4   a  provided in the capillary tube  4  is set larger than the beam diameter of the focused laser beam  10 , thereby preventing the focused laser beam from the energy loss to be caused by reflections, etc. On the other hand, because the focused laser beam hits and reflects on the conic portion  4   b  inside the capillary tube  4 , the inner wall  6   j  at that portion is polished like a mirror. 
     Hard metal or zirconia excellent in heat resistance will be suitable especially as the material of the action tube  6  formed at the tip of the capillary tube  4 . The mirror finishing process for the hard metal is done by a machine and the zirconia whose reflectivity is low is improved for the reflectivity through sputtering with use of such a metal with a high reflectivity as aluminum, gold, silver, or the like. 
     In the above described embodiment, the capillary tube is composed so that the cylindrical tube  5  and the action tube  6  are united. Consequently, it is possible to shorten the distance between the inner wall  6   j  of the conic portion to be mirror-finished and the opening of the connection portion  6 n in the action tube  6 , thereby the mirror finishing process can be carried out smoothly. 
     FIG. 2 is a perspective view of the tip shape of the conic portion  6   a  of the action tube  6 , which is a component of the capillary tube  4  of the embodiment according to the present invention. FIG.  3 ( a ) is a cross sectional view of a portion from the direction of the arrow D. the portion including the center line  50  of the action tube  6  shown in FIG. 2 and a datum line  51  orthogonal to this center line  50  and passing the tip ridge lines  6   c  and  6   d  formed in a process to be described later. FIG.  3 ( b ) is a cross sectional view of a portion from the direction of the arrow E, the portion including the datum line  52  orthogonal to both of the center line  50  and the datum line  51 , as well as the center line  50 . 
     As shown in FIG.  3 ( b ), at this tip are formed first tapered surfaces  6   e  and  6   f  at an angle of alpha and second tapered surfaces  6   g  and  6   h  at an angle of beta (beta&gt;alpha) so as to be continued to the first tapered surfaces. The first tapered surfaces  6   e  and  6   f , as well as the second tapered surfaces  6   g  and  6   h  are formed symmetrically with respect to the datum level including the center line  50  and the datum line  51  extending in a vertical direction on the paper with FIG.  3 ( b ). In addition, the extreme tip ridge line on the datum line  51  crossed by the tapered surfaces  6   e  and  6   f  becomes the tip ridge lines  6   c  and  6   d.    
     The inner diameter b (FIG. 3) of a ball ejection hall  6   b  is decided to a size in which the solder ball  122  (FIG. 4) can play freely. The depth h from the ridge lines  6   c  and  6   d  is decided necessarily by the thickness d, the taper angles alpha, beta, etc. of the action tube  6 . 
     The solder ball connection device  1  composed as described above is held by a transfer device (not shown) slidably in the directions F and G (FIG. 1) in which the gravity can be used. On the other hand, the HG assembly  100  (FIG. 8) is held by a holder (not shown) so as to be inclined at substantially 45° in the direction F and G in which the gravity can be used respectively so that the connection surfaces  118   a  and  112   b  of the bonding pad  118  and the lead pad  112   a  face each other substantially perpendicularly as shown in FIG.  4 . 
     The HG assembly  100  (FIG. 8) and the solder ball connection device  1  held respectively as described above, when the solder ball connection device  1  moves by a predetermined distance in the direction G, are positioned relatively so that the tip of the conic portion  6   a  of the action tube  6  makes an approach to both of the bonding pad  118  and the lead pad  112   a  equally. 
     Furthermore, the action tube  6  is attached so that the datum line  51  (FIG. 2) becomes in parallel to the connection surfaces  118   a  and  112   b  of the bonding pad  118  and the lead pad  112   a.    
     To carry out a solder ball connection processing in the configuration as described above, the tip of the conic portion  6   a  of the action tube  6  is moved to a position shown in FIG. 4 first. At this time, the second tapered surfaces  6   g  and  6   h  of the conic portion  6   a  approach the bonding pad  118  and the lead pad  112   a  almost coming in contact with them, but they are in a position where they do not come into contact with each other. 
     After that, the solder ball singulation disk  7   c  (FIG. 1) is rotated by a predetermined angle, thereby feeding one solder ball  122  into the capillary tube  4  through the nitrogen gas path  7   e . The solder ball  122  then falls into the capillary tube  4  and guided into the ball ejection hole  6   b . It then stops at a position where the ball comes in contact with the connection surfaces  118   a  and  112   b  of the bonding pad  118  and the lead pad  112   a  shown in FIG.  4 . During this time, the nitrogen gas is injected into the capillary tube  4  from the intake pipe  7   d  at a predetermined rate so as to prompt the solder ball to fall in the capillary tube  4 , as well as presses the solder ball  122  against the connection surfaces  118   a  and  112   b  with its wind pressure. 
     At this time, because the tip ridge lines  6   c  and  6   d  of the action tube  6  are positioned so as to be advanced more in the direction G than the regulation point P 1  passing the center of the solder ball  122 , the movement of the solder ball  122  towards the datum line  51  (FIG.  3 ( a )) is regulated by inner walls of the ridge lines  6   c  and  6   d  of the conic portion  6   a  at the regulation point P 1 . 
     On the other hand, the movement of the solder ball  122  towards the datum line  52  (FIG.  3 ( b )) is regulated by the connection surfaces  118   a  and  112   a  of the bonding pad  118  and the lead pad  112   a . Consequently, the solder ball  122  is positioned at a predetermined position, although it can move to the right/left slightly according to the difference between the its diameter c and the inner diameter b of the ball holding opening  6   b  (FIG.  6 ). 
     The laser light is emitted in this state. At this time, the focused laser beam  10  (FIG. 1) passes through the hollow cylindrical portion  4   a  of the capillary tube  4  and reaches the ball holding opening  6   b  while a part of the focused laser beam  10  is kept reflected on the mirror-finished inner wall  6   j  of the conic portion  4   b  as shown in FIG.  5 . The focused laser beam  10  then is irradiated on the solder ball  122  (FIG. 4) positioned there. 
     The solder ball  122  is melted by the irradiation of this laser beam, thereby making the connection surfaces  118   a  and  112   a  of the bonding pad  118  and the lead pad  112   a  wet and connected properly. 
     The nitrogen gas supplied at this time presses the melted solder against each connection surface and cover the solder so as to be protected from oxidation. 
     FIG. 6 shows a positional relationship among the solder  11  liquefied in reflowing and the tip ridge lines  6   c  and  6   d  of the capillary tube  4 . As shown in FIG. 6, if the tip ridge lines  6   c  and  6   d  are positioned so as to be advanced excessively in the direction G, they come in contact with the solder when in reflowing, thereby narrowing the gap through which the nitrogen gas is fed from the ball holding opening. Consequently, the gap is deviated, thereby the liquid solder is deformed. 
     These factors will then distort the shape of soldered portions and often cause contact failures. 
     This is why the tapered angles a and b shown in FIG.  3 ( b ) are set so that the capillary tube  4  is positioned so as to be advanced slightly in the direction G from the regulated point P 1  where the tip ridge lines  6   c  and  6   d  pass the center of the solder ball  122  if the second tapered surfaces  6   g  and  6   h  of the action tube  6  are moved to a predetermined position closest to the bonding pad  118  and the lead pad  112   a  respectively. 
     According to the capillary tube in the above described embodiment, therefore, it is possible to prevent the extreme tip of the capillary from touching liquid solder, as well as to enable the nitrogen gas to flow out in every direction, thereby soldering the object surfaces together free of distortion in shape. 
     In the embodiment described with reference to FIG.  3 ( b ), the first tapered surfaces  6   e  and  6   f  are formed at an angle of a and the second tapered surfaces  6   g  and  6   h  continued to the first tapered surfaces are formed at an angle of b respectively. However, the tip ridge lines  6   c  and  6   d  may also be formed with tapered surfaces formed only at one tapered angle. 
     Furthermore, as shown in FIG. 7 for another embodiment of the present invention, it may also be possible to form a pair of tapered portions  6   m  and  6   l  just like in the above described embodiment, as well as an extreme tip surface  6   k  perpendicular to the center line  50  so that the tip surface  6   k  is positioned so as to be slightly advanced in the direction G from the regulation point P 1  passing the center of the solder ball  122 . It is no need to form any ridge line at the extreme tip of the conic portion  6   a  at this time. 
     In the above described embodiment, a pair of projections of the tip of the solder ball regulator are formed at a portion where the first and second tapered surfaces are formed so that the tip ridge lines  6   c  and  6   d  are assumed as the tips of those first and second tapered surfaces. However, the pair of the projections are not limited only to those; they may be formed in various shapes such as bar-like projections. 
     Furthermore, in the above described embodiment, the center axis of the capillary tube is set so that its tip comes close to each flat surface while the center axis is inclined by substantially 45° to the connection surfaces  118   a  and  112   b  of the bonding pad  118  and the lead pad  112   a  respectively and the tapered surfaces at the tip of the capillary tube are formed symmetrically with respect to the surface including the center axis. However, the present invention is not limited to this, and the relationship between those items may be varied according to various required conditions. 
     Although the external shape of the solder ball regulator is formed conic in the above described embodiment, the shape may be varied freely unless it touches the slider and the leads during a work. 
     According to the capillary tube and the solder ball connection device of the present invention, a solder ball to reflow can be held in a stable manner, thereby solder connections can be made at predetermined points and it is possible to prevent connection failures to be caused by positional deviation of the connection. 
     Furthermore, because the surface on which the laser beam reflects is mirror-finished, it is possible to reduce the energy loss of the laser beam to be caused by such a reflection, as well as reduce the energy loss of the laser beam to occur when in reflowing, thereby making solder ball connections more efficiently.