Abstract:
An apparatus for conveyance of a semiconductor chip. The apparatus includes an arm for conveying a semiconductor chip, a pickup on the arm for holding the semiconductor chip. A first transmission mechanism is provided for producing power acting in a first direction. The first transmission mechanism includes pulleys and a wire. An interconnection mechanism is provided for interconnecting the wire and the arm for causing movement of the arm in the first direction. A second transmission mechanism is connected to the arm for moving the arm in a second direction which is substantially orthogonal to the first direction. The interconnection mechanism is configured to permit movement of the arm with respect to the first transmission mechanism in the second direction and to transmit the power from the first transmission mechanism to the arm.

Description:
BACKGROUND OF THE INVENTION 
     The invention relates to an apparatus for conveyance, in particular, to an apparatus for conveyance which is preferred for use in the manufacture of semiconductor chips. 
     A semiconductor manufacturing system generally comprises a bonder, which conveys semiconductor chips, and a feeder, which is mechanically coupled to and coordinated with the bonder for coordinated motion therewith for feeding lead frames. 
     Reference is now made to FIGS. 1 to  9  to describe a bonder  100  and a feeder  140  used in the prior art. In the description to follow, the lateral direction of bonder  100  and feeder  140  is defined as the X-axis direction, while the fore-and-aft direction thereof is defined as the Y-axis direction. 
     The bonder  100  will be described first with reference to FIGS. 1 to  7 . FIG. 1 is a top view, FIG. 2 a front view, FIG. 3 is a left-hand side elevation and FIG. 4 a right-hand side elevation of the bonder. 
     Referring to FIG. 1, the lower portion as viewed in FIG. 1 represents a front portion of the bonder  100  while the upper portion as viewed in FIG. 1 represents a rear portion of the bonder  100 . The bonder  100  includes a box-shaped first base  101  and a drive motor  102  fixed to the first base  101 . The motor  102  has an output shaft on which a disc cam  103  and a splined shaft  104  are mounted. A cylindrical cam  105  is mounted on the splined shaft  104  in an axially movable manner and includes a helical cam groove  105   a.    
     Referring to FIG. 4, an arm  107  is connected to the cylindrical cam  105  through a cam follower  108 , which is fixed to the arm  107  and is pressed into the cam groove  105   a  of the cylindrical cam  105 . A horizontal guide  106  is mounted on the first base  101  for guiding movement of the arm  107 . When the drive motor  102  is set in motion to rotate the cylindrical cam  105 , the arm  107  is reciprocated by the cam follower  108  in the X-axis direction. 
     Referring to FIG. 3, a plurality of vertical guides  109  are mounted on the lateral surface of the first base  101 , and a plate  110  connected to the vertical guides  109  is allowed to move in the vertical direction, or Z-axis direction. A rail  111  extending along the Y-axis direction is secured to the bottom of the plate  110 . As shown in FIG. 2, a cam follower  113  is secured to the top of the plate  110  through a connecting plate  112 . The cam follower  113  contacts the top of the disc cam  103 . When the drive motor  102  rotates the disc cam  103 , the plate  110  and the rail  111  are reciprocated by the cam follower  113  in the vertical direction. 
     Returning to FIG. 3, the arm  107  has a vertical guide  116  at one end, and a fastening member  115  fastens the vertical guide  116  and the rail  111 . The vertical guide  116  guides movement of the fastening member  115  in the vertical direction and guides movement of the fastening member  115  in the Y-axis direction. A bonding head or pickup head  114  is fixed to the fastening member  115 . When the drive motor  102  drives both the cylindrical cam  105  and the disc cam  103  for rotation simultaneously, the arm  107  moves in the Y-axis direction while the rail  111  moves in the vertical, or X-axis, direction. Accordingly, the pickup head  114  moves in the Y-axis direction in accordance with the movement of the arm  107  and moves in the vertical direction in accordance with the movement of the rail  111 . In this manner, the pickup head  114  performs a series of mounting operations through these movements in the both directions. 
     Returning to FIG. 1, an inching motor  117  is fixed to the lateral surface of the first base  101  at a location below the drive motor  102 . The inching motor  117  has an output shaft connected to a ball screw  118 , which is threaded to a linear bushing  119 . The linear bushing  119  slides along a shaft  120 , which extends in the Y-axis direction. The linear bushing  119  carries a cam follower  121  (see FIG.  2 ), which bears against a disc portion  122 , which is formed at one end of the cylindrical cam  105 . When the motor  117  drives the ball screw  118 , the linear bushing  119  and the cam follower  121  move in the Y-axis direction. As the cam follower  121  moves, the cylindrical cam  105  moves along the splined shaft  104 . The movement of the cylindrical cam  105  is transmitted through the cam follower  121  to cause an inching motion of the arm  107  and the pickup head  114 . 
     As shown in FIG. 2, a second base  124  is located below and supports the first base  101 . Above the second base  124 , a plurality of shafts  125  extend in the X-axis direction. A linear bushing  123  slides along these shafts  125 . The first base  101  is movable in the X-axis direction along the shafts  125 . 
     Another inching motor  126  is mounted on the second base  124  and has an output shaft having threads for engagement with the first base  101 . When the motor  126  drives the threaded shaft, the first base  101  is moved in the X-axis direction. As the first base  101  moves, the pickup head  114  undergoes an inching motion in the X-axis direction. 
     Referring to FIGS. 5 to  7 , the construction of the pickup head  114  will be described. FIG. 5 is a right-hand side elevation, FIG. 6 a top view and FIG. 7 a front view of the pickup head  114 . 
     Referring to FIG. 5, the pickup head  114  is provided with a leveling regulating mechanism for adjusting the lower surface of a collet  127 , which is used to hold a semiconductor chip in a horizontal plane. The pickup head  114  is constructed to a high structural rigidity with first to fourth metallic bodies  128  to  131 . The first body  128  is connected to a second body  129 , which is then connected to a third body  130 , which is, in turn, connected to the fourth body  131 . In each instance, the connection takes place by way of a screw  132 , the tightening of which may be regulated to bring the lower surface of the collet  127  into a horizontal plane. The first body  128  is pivotal about a fulcrum A relative to the second body  129 . As shown in FIG. 6, the second body  129  is pivotal about a fulcrum B relative to the third body  130 . As shown in FIG. 7, the third body  130  is pivotal about a fulcrum C relative to the fourth body  131 . 
     The bonder  100  causes the pickup head  114  to perform a series of normal mounting operations when the drive motor  102  is set in motion. The pickup head  114  undergoes an inching motion when the inching motors  117 ,  126  are set in motion, thus performing a fine adjustment of its position. Specifically, the position of the pickup head  114  when it picks up a semiconductor chip or when it loads a semiconductor chip on a lead frame is finely adjusted. 
     Referring now to FIGS. 8 and 9, the feeder  140  will be described. FIG. 8 is a side elevation of the feeder  140 , and FIG. 9 is a plan view of an essential part of the feeder  140 . 
     Referring to FIG. 8, the feeder  140  includes an actuator  133  extending in the X-axis direction and a carriage  134  mounted on top of the actuator  133 . In response to the actuation of the actuator  133 , the carriage  134  moves in the X-axis direction. The carriage  134  includes a damper  135  and an air cylinder  136  which drives the damper  135 . Thus, the damper  135  is moved in the Y-axis direction when the air cylinder  136 , is operated. The carriage  134  is fixed to a pipe bearer  137  formed by a plurality of interconnected sleeves and containing a piping, not shown, connected to the air cylinder  136 . 
     As shown in FIG. 9, the air cylinder  136  has a rod  136   a , which is connected to a linkage  138 , which is, in turn, connected to an upper damper  135   a  (see FIG.8) of the damper  135 . The upper damper  135   a  is rotatable about a rotary mechanism  139 . When the rod  136   a  is driven, the upper damper  135   a  assumes a pivoted position as shown in phantom lines in FIG. 8, thus opening the damper  135 . In this manner, the damper  135  is opened and closed in response to a movement of the air cylinder  136 . 
     In operation, the damper  135  carries a lead frame, not shown, and the carriage  134  brings the lead frame to a given position. The bonder  100  mounts a semiconductor chip on the lead frame which is brought to the given position. 
     However, the speed with which the pickup head  114  of the bonder  100  is moved or the speed of conveyance cannot be increased for the following reasons: 
     (1) the arm  107  carries, at its front end, the vertical guide  116 , which adds to the weight of the arm  107 ; 
     (2) the pickup head  144  is fixed on the fastening member  115 , which connects the vertical guide  116  to the rail  111 , thus increasing the weight of the movable assembly; 
     (3) when the pickup head  114  is to be moved in the Y-axis direction during a normal mounting operation, the arm  107  slides along the horizontal guide  106  while the fastening member  115  slides along the rail  111 , thus presenting an increased frictional resistance; 
     (4) when the pickup head  114  is moved in the Y-axis direction by the inching motion, the linear bushing  119  slides along the shaft  120  while the cylindrical cam  105  slides along the splined shaft  104 , thus presenting an increased frictional resistance; 
     (5) when the pickup head  114  is moved vertically during the normal mounting operation, the plate  110  slides along the vertical guide  109  while the fastening member  115  slides along the vertical guide  116 , again presenting an increased frictional resistance; and 
     (6) the first to the fourth bodies  128 - 131  are used for the pickup head  114  to allow the lower surface of the collet  127  to be brought into a horizontal plane. The high rigidity required for each of the bodies  128 - 131  necessarily increases their weight and adds to the weight of the pickup head  114 . 
     On the other hand, the feeder  140  includes the carriage  134 , which is provided with the air cylinder  136  to serve as a drive source for directly driving the damper  135 , thus adding to the weight of the carriage  134 . Consequently, the speed with which the damper  135  is moved or the speed of conveyance for the lead frames cannot be increased. 
     SUMMARY OF THE INVENTION 
     It is an object of the invention to provide an apparatus for conveyance and a semiconductor manufacturing system that permit an increase in the speed of conveyance. 
     To achieve the above objective, the present invention provides an apparatus for conveyance of a semiconductor chip, comprising: an arm for conveying a semiconductor chip; a holder member on the arm for holding the semiconductor chip; a first transmission mechanism for producing power acting in a first direction; an interconnection mechanism for interconnecting the first transmission mechanism and the arm for causing movement of the arm in the first direction; and a second transmission mechanism connected to the arm for moving the arm in a second direction which is substantially orthogonal to the first direction, wherein the interconnection mechanism is configured to permit movement of the arm with respect to the first transmission mechanism in the second direction and to transmit the power from the first transmission mechanism to the arm. 
     The present invention further provides a bonding head for conveying a semiconductor chip, comprising: a body; a collet supported by the body for holding a semiconductor chip; a pipe shaft for supporting the collet, wherein the body includes a through-opening extending vertically, for receiving the pipe shaft; and a regulation mechanism mounted on the body for regulating inclination of the collet, wherein the regulation mechanism including: a bearing received within the through-opening in a tiltable manner for supporting the pipe shaft; a support formed at the lower end of the through-opening for supporting part of the bearing; and a plurality of holding members for applying force to the bearing in mutually different directions at locations above the support for positioning the bearing. 
     The present invention provides a apparatus for conveyance comprising: a base extending along a particular conveying direction; a carriage that is movable on the base in the conveying direction; a first drive source for moving the carriage; a damper mounted on the carriage, the damper being and adapted to be selectively opened and closed for holding an article to be conveyed; a resilient member for urging the damper in a direction to close it; a second drive source on the base; and a transmission member for transmitting power from the second drive source to the resilient member to open the damper against the force the resilient member. 
     Other aspects and advantages of the invention will become apparent from the following description, taken in conjunction with the accompanying drawings, illustrating by way of example, the principles of the invention. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention, together with objects and advantages thereof, may best be understood by reference to the following description of the presently preferred embodiments together with the accompanying drawings in which: 
     FIG. 1 is a plan view of a conventional bonder; 
     FIG. 2 is a front view of the bonder of FIG.1; 
     FIG. 3 is a left-hand side elevation of the bonder of FIG. 1; 
     FIG. 4 is a right-hand side elevation of the bonder of FIG. 1; 
     FIG. 5 is a right-hand side elevation of a pickup head of the bonder of FIG. 1; 
     FIG. 6 is a plan view of the pickup head of FIG. 5; 
     FIG. 7 is a front view of the pickup head of FIG. 5; 
     FIG. 8 is a left-hand side elevation of a conventional feeder; 
     FIG. 9 is a plan view of an essential part of the feeder of FIG. 8; 
     FIG. 10 is a front view of a bonder according to one embodiment of the present invention: 
     FIG. 11 is a plan view of the bonder, of FIG. 10; 
     FIG. 12 is a left-hand side elevation of the bonder of FIG. 10; 
     FIG. 13 is a cross sectional view of the bonder of FIG. 10 as seen from the right side of FIG. 10; 
     FIG. 14 is a cross sectional view of an essential part of the bonder shown of FIG. 10; 
     FIG. 15 is a left-hand side elevation of a pickup head of the bonder of FIG. 10; 
     FIG. 16 is a cross sectional view taken along line  16 — 16  of FIG. 17; 
     FIG. 17 is a front view of the pickup head of FIG. 15; 
     FIG. 18 is a cross sectional view taken along line  18 — 18  of FIG. 16; 
     FIG. 19 is a left-hand side elevation of a regulating jig; 
     FIG. 20 is a front view of the regulating jig of FIG. 19; 
     FIG. 21 is a plan view of the regulating jig of FIG. 19; 
     FIG. 22 is a plan view of a left end of a feeder according to one embodiment of the present invention; 
     FIG. 23 is a plan view of a right end of the feeder of FIG. 22; 
     FIG. 24 is a front view of a left end of the feeder of FIG. 22; 
     FIG. 25 is a cross sectional view taken along line  25 — 25  of FIG. 22; 
     FIG. 26 is a side elevation of a clamper of the feeder of FIG. 22; and 
     FIG. 27 is a side elevation view like FIG.  26 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to FIGS. 10 to  27 , a semiconductor manufacturing system according to one embodiment of the present invention will now be described. The semiconductor manufacturing system comprises a bonder  200 , which conveys semiconductor chips, and a feeder  210 , which conveys lead frames in a manner coordinated with the bonder  200 . In the description to follow, the lateral direction of the bonder and the feeder  200 ,  210  is defined as the X-axis direction while the fore-and-aft direction is defined as Y-axis direction. 
     Referring to FIG. 10, the bonder  200  includes a cam unit  1  supported on a support frame, not shown. A drive motor  2  is located below the cam unit  1 . As shown in FIGS. 12 and 13, the drive motor has an output shaft  3  coupled through a belt  4  with an input shaft  5 , which projects from a rear part of the cam unit  1 . 
     First and second input shafts  6 ,  7  (FIG. 10) are rotatably supported on the cam unit  1 . The first output shaft  6  projects through the front surface of the cam unit  1  and rotates in an integral manner with the input shaft  5 . The second output shaft  7  projects through the left lateral surface of the cam unit  1  and is connected to the input shaft  5  through a rotary conversion mechanism, not shown. As the input shaft  5  rotates in one direction, the second output shaft  7  repeats a clockwise and a counter-clockwise rotation through a given angular range. 
     The second output shaft  7  is connected to a drive pulley  9  through a conventional differential output mechanism  8 . The differential output mechanism  8  includes an inching motor  10  and a reduction gearing  11 . An output assembly from the reduction gearing  11  is connected to the second output shaft  7 , and a casing of the inching motor  10  is fixed to the casing of the reduction gearing  11 . The drive pulley  9  is located around the reduction gearing  11 . 
     When the inching motor  10  is at rest, the second output shaft  7  and the drive pulley  9  rotate in an integral manner. However, when the inching motor  10  is activated, the drive pulley  9  rotates relative to the output assembly of the reduction gearing  11  or the second output shaft  7  by an amount corresponding to a difference between the angle of rotation of the output shaft of the motor  10  and the angle of rotation of the second output shaft  7 . 
     A frame  12  is fixed to the upper surface of the cam unit  1  and includes a stationary portion  12   a , which is secured to the upper surface of the cam unit  1 , and a support wall  12   b  extending upwardly from the left side of the stationary portion  12   a . Referring to FIG. 12, the frame  12  also includes an extension  12   c , which extends forwardly from the top of the support wall  12   b.    
     A movable block  14 , which can be moved in the Y-axis direction by an adjustment of bolt  13 , is mounted on the backside of the support wall  12   b  at its top, and a movable pulley  15  is rotatably supported on the movable block  14 . A pair of vertically aligned stationary pulleys  16 ,  17  are rotatably supported on the support wall  12   b  substantially in its central region. In addition, a stationary pulley  18  is rotatably supported on the free end of the extension  12   c . The movable pulley  15  and the stationary pulley  18  are located at the same elevation. A wire  19  extends around the drive pulley  9 , the movable pulley  15  and the stationary pulleys  16  to  18 , but the wire  19  may be replaced by a member such as a belt provided it is coupled to each of the pulleys  9  and  15  to  18  and is capable of transmitting power. The pulleys  9 ,  15 - 18  and the wire serves as first transmission mechanism. Torque from the drive pulley  9  is transmitted through the wire  19  to each of the pulleys  15  to  18 , and a portion  19   a  of the wire  19  located between the movable pulley  15  and the stationary pulley  18  moves in the Y-axis direction. Tension in the wire  19  is adjusted by adjusting the position of the movable block  14 . 
     Referring to FIGS. 10,  11  and  13 , a pair of horizontal guides  20   a ,  20   b  which extend in the X-axis direction, are fixed to the upper surface of the stationary portion  12   a . Each of the horizontal guides  20   a ,  20   b  is connected to an L-shaped plate  21  (FIG. 10) to be movable in the X-axis direction. Each of the L-shaped plates  21  includes a horizontal portion  21   a , which moves over the horizontal guides  21   a ,  21   b , and a vertical portion  21   b , which extends upwardly from one end of the horizontal portion  21   a.    
     As shown in FIG. 11, a drive motor  22  is fixed to the right end of the stationary portion  12   a , and has an output shaft connected to a drive screw  23 , which is in threaded engagement with the horizontal portion  21   a  of the L-shaped plate  21 . When the drive motor  22  drives the screw  23 , the threaded engagement causes the L-shaped plate  21  to be moved in the X-axis direction. 
     As shown in FIGS. 10 and 11, a pari of vertical guides  24   a ,  24   b , which extend vertically, are located along the right-hand side ofthe vertical portion  21   b  of the L-shaped plate  21 . A plate  25  is connected to the vertical guides  24   a ,  24   b . The vertical guides  24   a ,  24   b  allow a vertical movement of the plate  25 . The top of the plate  25  is formed with an extension  25   a , which extends forwardly. A vertical guide  26  (FIG.  10 ), which extends vertically, is located along the right-hand side of the palate  25 . A block  27  is connected to the vertical guide  26 , which permits vertical movement of the block  27 . 
     A disc cam  28  is fixed to the first output shaft  6  of the cam unit  1 , and a lever  29  is located above the disc cam  28 . The lever  29  has one end  29   a  that is supported to rotate with respect to the cam unit  1 . The lever  29  has a free end on which a cam follower  30  is located for abutment against the outer periphery of the disc cam  28 . 
     A rod-shaped link  31  has a lower end that is pivotally connected to the free end of the lever  29 , and its upper end is connected to the block  27 . When the first output shaft  6  rotates to cause rotation of the disc cam  28 , the free end of the lever  29  moves vertically, whereby the block  27  is driven through the link  31  to move vertically. The disc cam  28 , the lever  29 , the link  31 , the block  27  serves as second transmission mechanism. 
     Referring to FIG. 13, an inching motor  32  and a support  33  are fixed to the plate  25  at a location above the block  27 . The inching motor  32  has an output shaft, which is connected through the support  33  to a drive screw  34 . In this manner, the support  33  rotatably supports the output shaft of the motor  32 . The drive screw  34  has threads that engage with a top cover  27   a  of the block  27 . When the inching motor  32  remains at rest, a constant distance is maintained between the block  27  and the support  33 . By contrast, when the inching motor  32  drives the screw  34 , the threaded engagement adjusts the distance between the block  27  and the support  33 . Accordingly, the block  27  moves relative to the plate  25 . 
     Referring to FIGS. 10,  11  and  13 , a horizontal guide  35  is located along the left-hand side of the plate  25  at its top and extends from the rear end of the plate  25  to the free end of the extension  25   a . An arm  36 , which extends in the Y-axis direction is, connected to the horizontal guide  35 , which allows movement of the arm  36  in the Y-axis direction. As the plate  25  moves, the arm  36  is moved in the vertical direction. 
     The arm  36  is connected to the wire  19  through an interconnection mechanism  37 . The wire  19  is used to cause reciprocatory motion of the arm  36  in the Y-axis direction. Specifically, the rear end of the arm  36  is formed with a containing portion  36   a  (FIG. 12) which is open toward its left lateral surface. As shown in FIG. 14, a support shaft  38  which extends in the Y-axis direction is located within the containing portion  36 a and is connected with a swinging lever  39 , which is swingable about the axis of the support shaft  38 . 
     Located on the swinging lever  39  is a displacement absorbing guide  40 , which extends along the swinging lever  39  and which also extends in a radial direction to the support shaft  38 . A connecting member  41  is placed on the displacement absorbing guide  40  in a movable manner. A wire holding plate  42  is secured to the upper surface of the connecting member  41  by a screw  43 , and the wire  19   a  is sandwiched between the upper surface of the connecting member  41  and the wire holding plate  42 . 
     When the arm  36  is displaced in the X-axis direction with respect to the wire  19   a , the displacement absorbing guide  40  moves along the connecting member  41 . When the arm  36  is displaced in the Z-axis direction with respect to the wire  19   a , the swinging lever  39  swings about the support shaft  38 , as shown in double-dashed phantom lines in FIG. 14, while the displacement absorbing guide  40  moves along the connecting member  41 . As the wire  19   a  moves in the Y-axis direction, its power is transmitted to the arm  36  through the displacement absorbing guide  40  and the swinging lever  39 , with the result that the arm  36  moves in the Y-axis direction. In this manner, the interconnection mechanism  37  allows displacement of the arm  36  in both the vertical direction and the X-axis direction with respect to the wire  19   a  and also transmits the power from the wire  19   a , which acts in the Y-axis direction, to the arm  36 . Consequently, a reciprocatory motion of the wire  19   a  in the Y-axis direction causes a corresponding reciprocatory motion of the arm  36  in the Y-axis direction. 
     A pickup head  44  is secured to the front end  36   b  of the arm  36 . Specifically, the front end  36   b  of the arm  36  is formed with a horizontal mounting surface  36   c  and a vertical mounting surface  36   d , as shown in FIG.  16 . The horizontal mounting surface  36   c  represents the lower surface of the front end  36   b , which is substantially centrally formed with a vertically extending through-opening  36   e . The configuration of the horizontal mounting surface  36   c  conforms to the upper surface of a body  44   a  of the pickup head  44 . The body  44   a  comprises a single member. As shown in FIG. 15, the front end  36   b  and the pickup head  44  are secured together by means of a clamping member  46 . At this time, the upper surface and one lateral surface of the body  44   a  contact the horizontal mounting surface  36   c  and the vertical mounting surface  36   d , respectively. The other lateral surface of the body  44   a  contacts a washer  45 , which is secured to the lateral surface of the front end  36   b.    
     Referring to FIG. 16 again, the body  44   a  of the pickup head  44  is formed with a through-opening  44   b  which extends in the X-axis direction, and a threaded opening  44   c  (FIG.  16 ), which allows communication between the through-opening  44   b  and the through-opening  36   e  in the arm  36 . In addition, the body  44   a  is formed with a holding opening  44   d , which extends downward from the through-opening  44   b.    
     A pipe shaft  47  is located in the body  44   a  to extend through the threaded opening  44   c  and through the holding opening  44   d . The upper end of the pipe shaft  47  is connected to a vacuum hose  48  extending through the through-opening  36   e . The vacuum hose  48  is connected to a suction pipe  49 , which is located on top of the arm  36 . 
     A tubular elevation adjusting screw  50  is threaded into the threaded opening  44   c  and has an internal diameter that is greater than the external diameter of the pipe shaft  17 , thus allowing the pipe shaft  47  to extend through the adjusting screw  50 . An adjustment area  50   a  is formed on the bottom of the adjusting screw  50  and is located within the through-opening  44   b . A stop  51  is secured to the top of the pipe shaft  47  and abuts against the upper end face of the adjusting screw  50 , thereby restricting the downward movement of the pipe shaft  47  in the engaged position between the stop  51  and the adjusting screw  50  while permitting the upward movement of the pipe shaft  47 . The position of the pipe shaft  47 , which is controlled in this manner, can be regulated by changing the relative position of the adjusting screw  50  with respect to the body  44   a.    
     Threads are formed in a portion of the pipe shaft  47  located within the through-opening  44   b . The threads engage with a disc-shaped pressure regulating screw  52 , and a compressed spring  53  located between the upper surface of the pressure regulating screw  52  and the lower end of the elevation adjusting screw  50 . The pipe shaft  47  is urged by the spring  53  downward relative to the elevation adjusting screw  50 . In this manner, the pipe shaft  47  is maintained in a position where the stop  51  abuts against the elevation adjusting screw  50 . As the pressure regulating screw  52  is turned, the spacing of the pressure regulating screw  52  from the elevation adjusting screw  50  is changed, thus adjusting the force with which the pipe shaft  47  is urged by the spring  53 . 
     At its lowermost position, the inner peripheral surface of the holding opening  44   d  is formed with a rib  44   e , which is very thin. A tubular bearing  54  is received within the holding opening  44   d . The bearing  54  has an external diameter that is substantially equal to the internal diameter of the rib  44   e , and the outer periphery of the bearing at its lower end is in contact with the inner periphery of the rib  44   e . The lower end of the bearing  54  is held by a plate  44   f  having an internal diameter that substantially coincides with the external diameter of the pipe shaft  47 , thus allowing the bearing  54  to tilt about the inner periphery of the rib  44 e, which serves as a fulcrum. The bearing  54  supports the pipe shaft  47  in a slidable manner. 
     Tilt regulating screws  55   a - 55   d  are threaded to an upper portion of the holding opening  44   d  to hold the bearing  54  at any desired angle. Specifically, the body  44   a  is formed with four threaded openings  44   f - 44   i , which communicate with the holding opening  44   d , as shown in FIG. 18, and the threaded openings  44   f - 44   i  receive the regulating screws  55   a - 55   d , respectively. The regulating screws  55   a - 55   d  abut against the bearing  54  substantially at an equal angular intervals. The threaded openings  44   f - 44   h  extend radially from the centrally located holding opening  44   d  in a forward direction, to the left and to the right, respectively, while the threaded opening  44   i  extends rearwardly and obliquely to the right. The regulating screw  55   d  has a conical abutment  55   d   1  at its free end. Three regulating screws  55   a - 55   c  abut against the bearing  54  at their respective free ends, while the regulating screw  55   d  abuts against the bearing  54  with a bevelled surface defined by the conical abutment  55   d   1 . A desired angle of tilting, which the pipe shaft  47  and the bearing  54  form with respect to the rib  44   e , can be established by regulating the degree of tightening of the regulating screws  55   a - 55   d.    
     Returning to FIG. 16, a collet  56  is supported at the lower end of the pipe shaft  47 . Specifically, the bottom of the pipe shaft  47  is formed with a support  47   a  in which the collet  56  is to be mounted. The support  47   a  has an internal and an external diameter, which are greater than the internal and the external diameter of the pipe shaft  47 , respectively. The collet  56  comprises a lower part  56   a  having an attracting surface, not shown, on its lower surface, a cylindrical upper part  56   b , which extends upwardly from the lower part  56   a , and a cylindrical connector  56   c , which extends further upward from the upper part  56   b . The connector  56   c  of the collet  56  is fitted into an opening in the support  47   a  of the pipe shaft  47  and is then secured by a screw  57 . When the degree of tightening the respective regulating screws  55   a - 55   d  is adjusted, the leveling degree of the collet  56  is adjusted in accordance with the tilt angle of the pipe shaft  47 . 
     The bottom of the body  44   a  is formed with a projection  44   j , which projects forwardly and which carries a pair of downwardly extending guide pieces  44   k  (FIG. 17) at its free end. A pin  58  having a free end for contacting the guide pieces  44   k  is secured to the support  47   a . Accordingly, the pipe shaft  47  and the collet  56  are vertically guided along the guide pieces  44   k  without undergoing any rotation. 
     Referring now to FIGS. 19 to  21 , a regulating jig  220  used to regulate various parts of the pickup head  44  will be described. As shown in FIG. 19, the regulating jig  220  includes a base  59 , a stanchion  60 , which is fixed to a rear portion of the base  59 , and an arm  61  extending forwardly from the top of the stanchion  60 . 
     The arm  61  is configured in substantially the same manner as the front end  36   b  of the arm  36  of the bonder  200  and has a horizontal mounting surface  61   a  on which the pickup head  44  to be regulated is secured. 
     An adjusting table  62  is located on the front end of the base  59 . The adjusting table  62  has an upper surface that is parallel to the horizontal mounting surface  61   a  of the arm  61 . A distance between the upper surface of the adjusting table  62  and the horizontal mounting surface  61   a  of the arm  61  is set to be equal to a distance that is used in performing the mounting operation when the pickup head  44  is secured to the bonder  200 . 
     Referring to FIG. 20, a regulation block  63 , which is movable in the X-axis direction, is located on the base  59  at a location toward the left side thereof, or forwardly, and the right lateral surface of the regulating block  63  runs orthogonally to the X-axis. 
     A tension gauge  64  is located on the base  59 , toward its right side, or rearwardly, and has a measuring shaft  65  connected to a balance mechanism  66  located within the base  59 . The balance mechanism  66  includes a push-up pin  68 , which abuts against the collet  56 . The tension gauge  64  determines the pressure acting on the collet  56  as it is pushed up by the pin  68 , by screwing an adjust bolt  67 . 
     To regulate the leveling degree of the collet  56 , the collet  56  of the pickup head  44  is abutted against the upper surface of the adjusting table  62 . Under this condition, individual tilting adjusting screws  55   a - 55   d  are adjusted, thus regulating the leveling degree of the collet  56  with a high precision. To regulate the angular position of the collet  56  around the pipe shaft  47 , the collet  56  is abutted against the upper surface of the adjusting table  62  while the holding screw  57  for the pickup head  44  is loosened. The regulation block  63  is moved so that the right lateral surface of the regulation block  63  abuts against the left lateral surface of the collet  56 . The angular position of the collet  56  around the pipe shaft  47  is adjusted while the collet  56  is held by the adjusting table  62  and the regulation block  63 . 
     To adjust the force of the spring  53  that urges the pipe shaft  47  and hence the collet  56 , the adjust bolt is turned while maintaining the collet  56  of the pickup head  44  in abutment against the upper surface of the adjusting table  62 . In this manner, the force of the spring  53  acting on the collet  56  is determined by the tension gauge  64 . By adjusting the pressure regulating screw  52  with reference to a value read from the tension gauge, the force of the spring  53  that acts on the collet  56  is set up to a desired value. 
     The operation of the bonder  200  will now be described. Referring to FIG. 13, when the drive motor  2  is rotated, the first output shaft  6  and the disc cam  28  are rotated. The rotating motion of the disc cam  28  is translated through the link  31  into vertical motion of the block  27 , which accompanies vertical motion of the plate  25  and the arm  36 . 
     Referring to FIG. 12, when the drive motor  2  is set in motion, the second output shaft  7  alternatively rotates through a given angular range in the clockwise and the counter-clockwise directions. As the second output shaft  7  rotates, the drive pulley  9  rotates in an integral manner. The rotation of the drive pulley  9  produces a reciprocation of the wire  19   a  located between the movable pulley  15  and the stationary pulley  18  in the Y-axis direction, and reciprocattion of the wire  19 a produces a reciprocatory motion in the Y-axis direction of the arm  36 , which is connected thereto through the interconnection mechanism  37 . 
     Accordingly, when the drive motor  2  rotates, the arm  36  moves in both the Y-axis direction and the vertical direction, thereby conveying a chip on a wafer plate, not shown, onto a lead frame to be described later. 
     When the inching motor  10  is set in motion, the drive pulley  9  rotates relative to the second output shaft  7 , and the pickup head  44  is inched in the fore-and-aft direction by an amount corresponding to the relative rotation of the drive pulley  9 . 
     Referring to FIG. 11, when the drive motor  22  is rotated, the L-shaped plate  21  moves in the X-axis direction, and the plate  25 , the arm  36  and the pickup head  44  also move in the X-axis direction together with the plate  21 . 
     Returning to FIG. 13, when the inching motor  32  rotates, the plate  25  moves with respect to the block  27  in the vertical direction, and thus the pickup head  44  is inched in the vertical direction. This allows the pickup head  44  to accommodate lead frames of varying thicknesses. 
     The operations of the inching motors  10 ,  22  and  32  produce an inching motion of the pickup head  44  in the Y-axis, X-axis and the vertical direction, which permits a so-called scrub operation when mounting a semiconductor chip. In addition, a fine adjustment of positions where a semiconductor chip is picked up or where a semiconductor chip is mounted on a lead frame also takes place. 
     Referring now to FIGS. 22 to  27 , a feeder  210  will be described. 
     In FIG. 22, the bottom of this Figure represents the front side of the feeder  21  while the top of the Figure represents the rear side of the feeder  210 . The feeder  21  includes a transversely extending base  69 , a rail  69   a  located rearward of the base  69 , and a conveyor section  69   b  located in the forward portion of the base  69 . Both the rail  69   a  and the conveyor section  69   b  extend lengthwise of the base  69 . 
     Referring to FIGS. 22 and 24, a feed motor  70  is fixed to a left end of the rail  69   a  and has an output shaft connected to a feed screw  71 , which extends lengthwise of the rail  69   a . The feed screw  71  is supported by a bearing  72  located midway along the length of the rail  69   a . A horizontal guide  73  is located forwardly of the rail  69   a  and extends along the rail  69   a.    
     A carriage  74 , which has threads that engage with the feed screw  71 , moves along the horizontal guide  73 . 
     Accordingly, when the feed motor  70  is rotates the feed screw  71 , the cause the carriage  74  to be moved transversely, or in the X-axis direction. 
     A damper  75  is located forwardly of the carriage  74 . Specifically, a pair of vertical guides  76   a ,  76   b  are located forwardly of the carriage  74  and extend vertically. A first block  77   a , having a lower damper  75   a , is connected to the left vertical guide  76   a , which permits vertical movement of the first block  77   a . A second block  77   b , having an upper damper  75   b , is connected to the right vertical guide  76   b , which permits vertical movement of the second block  77   b.    
     The first block  77   a  is urged upward by a spring  78   a  (FIG. 25) while the second block  77   b  is urged downward by a spring  78   b  (FIG.  25 ). The front surfaces of the first and second blocks  77   a ,  77   b  rotatably carry a first and a second transmission roller  79   a ,  79   b  (FIG.  26 ), respectively. 
     A drive cylinder  80  is located on the rail  69   a  at a location forward of the feed motor  70 . The drive cylinder  80  includes a rod  81 , which is connected to one end of a transmission wire  82 . The other end of the transmission wire  82  is secured to an anchorage  84  located forward of the bearing  72  after passing through a pair of stationary rollers  83 . The transmission wire  82  runs substantially parallel to the feed screw  71 . As shown in FIG. 26, a given tension is produced in the transmission wire  82  by its abutment against the first and second transmission rollers  79   a ,  79   b . Under this condition, the first and second blocks  79   a ,  79   b  assume their initial positions when the upper damper  75   a  and the lower damper  75   b  abut against each other. 
     When the drive cylinder  80  is operated to increase the tension in the transmission wire  82  by means of the rod  81 , the first block  77   a  is moved downward and the second block  77   b  is moved upward against the forces of the springs  78   a ,  78   b , respectively, whereby the upper damper  75   b  and the lower  75   a  are separated from each other to open the damper  75 . When the drive cylinder  80  is operated to decrease the tension in the transmission wire  82 , the upper damper  75   b  and the lower damper  75   a  are attracted toward each other under the action of the springs  78 , thus closing the damper  75 . Alternatively, the damper  75  is opened or closed by allowing only one of the upper and the lower damper  75   a ,  75   b  to be operated. For example, the lower damper  75   a  may be fixed while the upper damper  75   b  may be movable. Conversely, the upper damper  75   b  is fixed while the lower damper  75   a  may be movable. 
     Referring to FIG. 23, an arrangement including a feed motor  85 , a feed screw  86 , a carriage  87 , a damper  88 , a drive cylinder  89  and a transmission wire  90  is located to the right of the bearing  72  in a similar manner to the arrangement disposed to the left of the bearing  72 , or in a symmetrical manner with respect to the bearing  72 , and the arrangement is associated with the rail  69   a.    
     The operation of the feeder  210  will now be described. 
     When the feed motors  70 ,  85  are driven, the carriages  74 ,  87  are moved transversely. The carriages  74 ,  87  move relative to the transmission wires  82 ,  90 , respectively, but because the first and second transmission rollers  79   a ,  79   b  are rotating, the tension acting upon the first and second transmission rollers  79   a ,  79   b  remains unchanged. Accordingly, the open/closed conditions of the dampers  75 ,  88  are maintained independently from the positions of the carriages  74 ,  87 . The dampers  75 ,  88  are selectively opened or closed by the operation of the drive motors  80 ,  89 . The feeder  210  conveys a lead frame, not shown, by controlling the opening/closing and the transverse movement of the dampers  75 ,  88 . 
     A first and a second support  91 ,  92 , which have an outer profile slightly larger than the outer profile of a semiconductor chip, are located in the conveyor section  69   b . The first support  91  is located corresponding to a mid-position of the feed screw  71 , and the second support  92  is located corresponding to the location of the bearing  72 . 
     A dispenser, not shown, for feeding an adhesive material to die pads on a lead frame is located above the first support  91 , and the pickup head  44  of the bonder  200  is located above the second support  92 . 
     When a lead frame  93 , shown in double-dashed phantom lines in FIG. 22, is fed to a supply position on the feeder  210 , the carriage  74  causes the damper  75  to hold the lead frame  93  and then conveys it to a position above the first support  91 . Then, the dispenser operates, applying the adhesive material to the lead frame  93 . Subsequently, the carriage  74  conveys the lead frame  93  to a delivery position P 1 . The carriage  87  then operates to convey the lead frame  93  to a position P 2  above the second support  92 . The pickup head  44  of the bonder  200  then mounts a semiconductor chip on the lead frame  93 . Subsequently, the carriage  87  conveys the lead frame  93  to a completion position. 
     As a result of the described construction and operation of the bonder  200  and the feeder  210  according to this embodiment, the following results are achieved. 
     The bonder  200  employs the wire  19   a  to produce the reciprocatory motion of the arm  36  in the Y-axis direction. 
     Because the second output shaft  7  and the drive pulley  9  are connected together through the differential output mechanism  8 , the inching motion of the arm  36  and the pickup head  44  in the Y-axis direction takes place without using any guide. There is no need for special guide for the fine adjustment of the vertical position of the pickup head  44 , because the relative movement of the block  27  and the plate  25  in the vertical direction provides a fine adjustment of the elevation of the pickup head  44 . Accordingly, the number of guides used is reduced as compared with the conventional bonder  100 , reducing the weight of the movable part on the arm  36  and permitting a higher speed of conveyance. 
     Since the pickup head  44  comprises the single body  44   a , its weight is reduced as compared with the four bodies  128  to  131  used in the prior art arrangement. 
     The angle of inclination of the collet  56  is adjusted to a high precision through a simple operation of adjusting the threaded positions of the four tilting adjusting screws  55   a - 55   d . Specifically, the bearing  54  tilts about its lower end, which serves as a fulcrum within the holding opening  44   d . In other words, since the fulcrum for the tilting motion is established at a point that is located close to the collet  56 , fine adjustment of the tilting of the collet  56  is achieved. 
     With respect to the feeder  210 , the drive cylinders  80 ,  89 , which directly drive the dampers  75 ,  88 , are fixed outside the carriages  74 ,  87 , thus reducing their weight as compared with the conventional carriage  134 . In this manner, a higher speed of movement of the carriages  74 ,  87  is permitted. 
     Therefore, the present examples and embodiments are to be considered as illustrative and not restrictive and the invention is not to be limited to the details given herein, but may be modified within the scope and equivalence of the appended claims.