Abstract:
A flux spray machine for spraying flux to printed circuit board assembly (PCBA) is provided, which comprising: a PCBA transfer track to transferring the PCBA for spraying flux, comprising an active beam and a fixed beam; a spray mechanism, a X-Y table of vertical spray mechanism comprising a longitudinal beam, a crossbeam movable on and perpendicular to the longitudinal beam, and a flux nozzle for spraying flux movably provided on the crossbeam; and a flow-controlling mechanism, comprising origin sensors and limit sensors for two different flows in two longitudinal directions of the PCBA transfer track.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims benefits of Chinese Patent Application No. 201210451016.5, filed on Nov. 12, 2012 in the State Intellectual Property Office of China, the disclosure of which is incorporated herein by reference in its entirety. 
       FIELD OF THE INVENTION 
       [0002]    The present disclosure relates to a flux spray machine, and to a flux spray machine for spraying soldering flux in a wave soldering process. 
       DISCUSSION OF RELATED ART 
       [0003]    Soldering flux spraying of the flux spray machine is important to a wave soldering process. However, the production flow of the flux spray machine in the related art is consistent with the flow of the insert line. Therefore, prior to the purchase of the flux spray machine, the equipment supplier is required to configure the flow of the flux spray machine according to the pre-determined flow of the insert line, and the configured flow direction is fixed and unchangeable. If the flow of the flux spray machine has to be changed due to equipment relocation or production need, the equipment cannot be used any more, resulting in the re-purchase of new equipment and the waste of the old idle equipment. 
         [0004]    As shown in  FIGS. 1 and 2 , in the flux spray machine  91  of the related art, one side of a transfer track for printed circuit board assembly (PCBA) adjacent to the operator is a fixed edge  94 , the other side is an active edge  95 , and a width of the PCBA transfer track is adjusted by adjusting the active edge  95 . 
         [0005]    As shown in  FIGS. 1 and 2 , the PCBA transfer structure for the flux spray machine  91  in the related art has only a one-way flow, i.e., from left to right or from right to left, as indicated by arrows shown in figures. According to such a design, if the equipment relocation or the re-arrangement of the production line causes the flow to change, the flux spray machine can not be used any more. A set of new equipment meeting the requirement to the new flow has to be purchased, and thus the old idle equipment will be idle and wasted. 
         [0006]    Further, in the flux spray machine  91  in the related art, when a flux nozzle  92  of a spray mechanism  93  is performing a flux spray process, an angle difference between the PCBA  96  and the nozzle  92  is in a range of 0 to 7 degrees, thereby resulting in the shadowing effect to through holes of PCBA  96  and affecting spraying quality of the soldering flux spray. 
         [0007]    Moreover, the nozzle  92  of the flux spray machine  91  in the related art can only do one-way movement along longitudinal direction of the spray mechanism  93 . The movement of the spray mechanism  93  is not flexible enough, and the different equipment uses are not considered and thus the use of the equipment is not flexible. 
       SUMMARY 
       [0008]    The present disclosure provides a flux spray machine supporting two-way flows and having a spray mechanism capable of flexible moving. 
         [0009]    The present disclosure further provides a flux spray machine, of which the flux nozzle of the spray mechanism can be adjusted with angle changes of the transfer track, thereby the shadowing effect to the through hole of PCBA resulting from the flux nozzle which is not adjustable with angle changes of the transfer track is overcome. 
         [0010]    According to an aspect of the invention, a flux spray machine for spraying flux to printed circuit board assembly (PCBA) is provided, which comprising: a PCBA transfer track to transferring the PCBA for spraying flux, comprising an active beam and a fixed beam; a spray mechanism, a X-Y table of vertical spray mechanism comprising a longitudinal beam, a crossbeam movable on and perpendicular to the longitudinal beam, and a flux nozzle for spraying flux movably provided on the crossbeam; and a flow-controlling mechanism, comprising origin sensors and limit sensors for two different flows in two longitudinal directions of the PCBA transfer track. 
         [0011]    For example, the flow-controlling mechanism comprises a first limit sensor, a first origin sensor, a second origin sensor and a second limit sensor, which are sequentially provided in a first direction at the fixed beam, wherein the first limit sensor and the second origin sensor are used for a first flow along the first direction, and the first origin sensor and the second limit sensor are used for a second flow along a second direction opposite to the first direction. 
         [0012]    For example, comprising two longitudinal beams, wherein the crossbeam is provided between the two longitudinal beams, each of which is provided with a linear slide rail, an end portion of the crossbeam is connected with the linear rail, and the crossbeam is provided with a linear slide rail for the flux nozzle to move thereon. 
         [0013]    For example, the two longitudinal beams are a primary longitudinal beam and a secondary longitudinal beam respectively, the primary longitudinal beam is provided with a first servomotor for driving the crossbeam to move, the crossbeam is provided with a second servomotor for driving the flux nozzle to move. 
         [0014]    For example, further comprising a width-adjusting mechanism for adjusting a distance between the active beam and the fixed beam, the width-adjusting mechanism comprising a top frame disposed over the PCBA transfer track, a driving mechanism provided at a center of the top frame, a connecting component connected between the PCBA transfer track and the driving mechanism, and a third servomotor for driving the driving mechanism to move the active beam close to or away from the fixed beam. 
         [0015]    For example, opposite ends of active beam and the fixed beam are connected a driving shaft and a driven shaft, respectively, and wherein the active beam slides along the driving shaft and the driven shaft while moving close to or away from the fixed beam. 
         [0016]    For example, the driving mechanism is a screw nut-and-rod driving mechanism, wherein the connecting component comprises a central connecting component and a sliding component, the central connecting component being connected and fixed below a screw nut of the driving mechanism and being perpendicularly connected to a top surface of the active beam, a bottom end of the sliding component being connected with the top surface of the active beam, a top end of the sliding component being lapped over an inner side of the top frame and being movable along the top frame. 
         [0017]    For example, connecting plates are fixed and connected between the top frame and the opposite end portions of the longitudinal beams of the spray mechanism. 
         [0018]    For example, further comprising an angle-adjusting mechanism for adjusting an angle between the PCBA transfer track and a horizontal plane, the angle-adjusting mechanism comprising two pairs of synchronizing lifting columns provided below four corners of the top frame respectively. 
         [0019]    For example, connecting plates are fixed and connected between the top frame and the opposite end portions of the longitudinal beams of the spray mechanism, wherein the top frame is fixed and connected to the PCBA transfer track, and wherein the top frame is relatively parallel to a spray plane of the spray mechanism and relatively parallel to a transfer plane of the PCBA transfer track. 
         [0020]    For example, the lifting column comprises a wedge-shaped base, a lifting mechanism provided in the wedge-shaped base, a connecting plate connected to an output screw rod of the lifting mechanism, and a driving component for driving the lifting mechanism, wherein an upper end of the connecting plate is hinged to the top frame, wherein two output screw rods of a pair of synchronizing lifting columns are provided with synchronizing gears, and a timing chain is connected between the gears. 
         [0021]    For example, an adjusting angle range of the angle-adjusting mechanism is in 0 to 10 degrees. 
         [0022]    For example, a fixing component is further fixed and connected between the fixed beam and the top frame. 
         [0023]    For example, the top frame is of a rectangle shape formed by a back top beam, a front top beam, a left top beam and a right top beam, two sliding components and two fixing components are connected with the left top beam and the right top beam in left-to-right symmetry. 
         [0024]    For example, the driving component is disposed close to a side of the fixed beam. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0025]      FIG. 1  is a schematic front view of a flux spray machine in the related art. 
           [0026]      FIG. 2  is a schematic top view of a flux spray machine in the related art. 
           [0027]      FIG. 3  is a schematic top view of a flux spray machine according to an embodiment of the present disclosure. 
           [0028]      FIG. 4  is a schematic top view of a table spray mechanism according to an embodiment of the present disclosure. 
           [0029]      FIG. 5  is a schematic perspective view of a perpendicular spray mechanism according to an embodiment of the present disclosure. 
           [0030]      FIG. 6  is a schematic perspective view of a flux spray machine without a spray mechanism according to an embodiment of the present disclosure. 
           [0031]      FIG. 7  is a schematic perspective view of a flux spray machine with a spray mechanism according to an embodiment of the present disclosure. 
           [0032]      FIG. 8  is a schematic back view of a flux spray machine according to an embodiment of the present disclosure. 
           [0033]      FIG. 9  is a schematic font view of a width-adjusting mechanism of a flux spray machine according to an embodiment of the present disclosure. 
           [0034]      FIGS. 10 and 11  show different spray angles of the flux spray machine for comparison. 
           [0035]      FIG. 12  is a schematic perspective view of a flux spray machine after the track angle is adjusted. 
       
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
       [0036]    Some exemplary embodiments embodying the features and the advantages of the present disclosure will be illustrated in the following detailed description. 
         [0037]    It will be understood that various changes to various embodiments does not depart from the scope of the invention, and thus the description and the figures thereof are essentially used for illustration rather than limitation. 
         [0038]    As shown in  FIGS. 3 ,  9  and  12 , the flux spray machine of the present embodiment mainly comprises a PCBA transfer track  1 , a width-adjusting mechanism  2 , a flow-controlling mechanism, an angle-adjusting mechanism  4  and a spray mechanism  7 . 
         [0039]    The PCBA transfer track  1  is used to transfer PCBA, the flow-controlling mechanism achieves two-way flow control through sensing and positioning of the sensor, the width-adjusting mechanism  2  is used to adjust a width (pitch) of the PCBA transfer track, the angle-adjusting mechanism  4  is used to adjust an angle between the PCBA transfer track  1  and the horizontal plane, and the spray mechanism  7  is an execution unit for the flux spray. 
         [0040]    The following description will illustrate various components of the flux spray machine according to an embodiment of the present disclosure. 
         [0000]    1. PCBA transfer track  1   
         [0041]    As shown in  FIGS. 3 and 7 , in the flux spray machine of the present embodiment, the PCBA transfer track  1  comprises an active beam  11  and a fixed beam  12  parallel to each other. A driving shaft  13  is in connection with ends of the active beam  11  and the fixed beam  12 , and a driven shaft  14  is in connection with opposite ends of the active beam  11  and the fixed beam  12 . For adjusting the width of the PCBA transfer track  1 , the active beam  11  slides close to or away from the fixed beam  12  along the driving shaft  13  and the driven shaft  14 , thereby changing the pitch of the PCBA transfer track  1 . To achieve the transmitting and sliding support functions of the driving shaft  13  and the driven shaft  14 , the driving shaft  13  and the driven shaft  14  are spline shafts or provided with key slots. 
         [0042]    In operation, the operator stands by the fixed beam  12 . 
         [0043]    Therefore, the words of before, after, left, right in the present specification is based the observation view of the operator. 
         [0044]    As shown in  FIGS. 3 ,  7  and  9 , a track transfer motor  15  is provided at the right end portion of the fixed beam  12  to generate a driving force for transferring the PCBA  9 . The track transfer motor  15  is connected with a conveyor belt (or conveyor chain)  16  to transfer the PCBA  9 . During transferring, the PCBA  9  is supported on a carrying frame  6  through supporting members. 
         [0045]    The loading or unloading direction of the PCBA  9  is controlled by the rotation direction of the track transfer motor  15 , after the flow direction is set. The transfer speed is automatically adjusted by the track transfer motor  15  according to the set parameters. 
         [0000]    2. Spray mechanism  7   
         [0046]    As shown in  FIGS. 4 and 5 , the spray mechanism  7  is provided below the PCBA transfer track  1 . 
         [0047]    An X-Y table frame of the spray mechanism  7  comprises a primary longitudinal beam  72 , a secondary longitudinal beam  71  and a crossbeam  73 . The primary longitudinal beam  72  is parallel to the secondary longitudinal beam  71 , and the primary longitudinal beam  72  and the secondary longitudinal beam  71  are perpendicular to the crossbeam  73  and parallel to the active beam  11  and the fixed beam  12 . The primary longitudinal beam  72  is relatively close to the fixed beam  12 , the secondary longitudinal beam  71  is relatively close to the active beam  11 , and the distance between the primary longitudinal beam  72  and the secondary longitudinal beam  71  is larger than that between the active beam  11  and the fixed beam  12 . 
         [0048]    The primary longitudinal beam  72  and the secondary longitudinal beam  71  are equivalent to the X-axis, and the crossbeam  73  is equivalent to the Y-axis. A servomotor  77  is provided at the X-axis, and a servomotor  76  is provided at the Y-axis. The servomotors  76  and  77  independently control a movement direction and a movement speed of the flux nozzle  79 , and a movement location or a movement coordinate is accurately recorded via an encoder. 
         [0049]    The primary longitudinal beam  72  and the secondary longitudinal beam  71  are provided with linear slide rails  70  respectively, and two ends of the crossbeam  73  slide along the linear rails  70 . The force for driving the crossbeam  73  to slide comes from the servomotor  77 . One end of the crossbeam  73  close to the primary longitudinal beam  72  is fixed to a driving belt  75  connected with the servomotor  77 , thereby obtaining a force for the crossbeam  73  to slide. 
         [0050]    The flux nozzle  79  is provided at the crossbeam  73 . To be more specific, the flux nozzle  79  is fixed to the driving belt  78  connected with the servomotor  76 . The crossbeam  73  is also provided with linear slide rails  74 ; the flux nozzle  79  is driven by the servomotor  76  and thus slides along the linear slide rails  74 . 
         [0051]    The movement speed, location and coordinate of the flux nozzle  79  can be controlled, calculated and instructed by a computer program. 
         [0052]    As shown in  FIG. 7 , the spray mechanism  7  is suspended from the width-adjusting mechanism  2 . To be more specific, two ends of the primary beam  72  and two ends of the secondary beam  71  are in perpendicular connection with connecting plates  8 , top ends of which are in connection with a back top beam  24  and a front top beam  21  of the width-adjusting mechanism  2  respectively. 
         [0000]    3. Width-adjusting mechanism  2   
         [0053]    When the width of the PCBA  9  or the carrying frame  6  for carrying the PCBA  9  is changed or needs to be adjusted, the width-adjusting mechanism  2  automatically adjusts the distance between the active beam  11  and the fixed beam  12  according to the set parameters. 
         [0054]    As shown in  FIGS. 7 through 9 , the width-adjusting mechanism  2  comprises a top frame, which can be a rectangule form or a square form formed by a left top beam  23 , a right top beam  22 , the back top beam  24  and the front top beam  21 , wherein a top frame crossbar  20  is provided between the back top beam  24  and the front top bean  21 . An outer side surface of the front top beam  21  is provided with a servomotor  26 , which drives the active beam  11  through a driving belt  27 , to change the width of the tracks. 
         [0055]    To be more specific, the servomotor  26  directly drives a screw rod of a screw nut-and-rod driving mechanism  29  through the driving belt  27 . One end of the screw rod is in connection with the driving belt  27 , which drives the screw rod to rotate through the servomotor  26 , thereby changing a relative position of the screw nut on the screw rod in the screw nut-and-rod driving mechanism  29 . As shown in  FIGS. 7 and 9 , the screw nut is in connection with a top surface of the active beam  11  through a central connecting component  28 , thereby driving the active beam  11  to slide to increase or decrease the pitch of the tracks. 
         [0056]    As shown in  FIGS. 6 and 9 , to enhance the stability of the entire flux spray machine, sliding components  48  are provided between the active beam  11  and the left top beam  23  as well as between the active beam  11  and the right top beam  22 . Top ends of the sliding components  48  are lapped over step portions at opposite inner sides of the left top beam  23  and the right top beam  22 , and bottom ends of the sliding components  48  are fixed to top surfaces of the active beam  11 . When the active beam  11  is moving, the sliding component  48  may slide relative to the step portions of the left top beam  23  and the right top beam  22 . 
         [0057]    Fixing components  49  are provided between the fixed beam  12  and the left top beam  23  as well as between the fixed beam  12  and the right top beam  22 . Top ends of the fixing components  49  are fixed to opposite inner sides of the left top beam  23  and the right top beam  22 , and bottom ends of the fixing components  49  are fixed to a top surface of the fixed beam  12 . 
         [0058]    In this embodiment, the width-adjusting mechanism  2  is disposed over the PCBA transfer track  1 , and the spray mechanism  7  is provided below the PCBA transfer track  1 , but the present invention is not limited thereto. 
         [0000]    4. Flow-controlling mechanism 
         [0059]    As shown in  FIG. 3 , the flow-controlling mechanism of the present embodiment comprises four sensors/stoppers sequentially arranged at the fixed beam  12 , that is, a limit sensor  31 , an origin sensor  32 , an origin sensor  33  and a limit sensor  34 . 
         [0060]    The origin sensors  32  and  33  are used to detect whether the PCBA  9  reaches a location where the flux nozzle  79  may start to operate. The detection can be compensated for correction through software. 
         [0061]    The limit sensors  31  and  34  are used to detect whether the position of the next PCBA  9  or the next carrying frame  6  is beyond the set position. 
         [0062]    When the flow of the flux spray machine is from left to right as shown in  FIG. 3 , the limit sensor  31  and the origin sensor  33  will effectively perform the functions of sensing and locating the PCBA, and the position of origin sensor  33  is defined as the origin (starting position) of the left-to-right flow. 
         [0063]    When the flow of the flux spray machine is from right to left as shown in  FIG. 3 , the limit sensor  34  and the origin sensor  32  will effectively perform the functions of sensing and locating the PCBA, and the position of origin sensor  32  is defined as the origin (starting position) of the right-to-left flow. 
         [0064]    When the PCBA  9  is carried by the carrying frame  6 , the spray starting position of the PCBA  9  is different from the flow origin. Due to the area of the PCBA  9  being less than that of the carrying frame  6 , the spray starting position of the spray mechanism must be corrected through software compensation. As shown in  FIG. 3 , the spray starting position of the PCBA  9  (or referred to as the origin of the nozzle) may be set to the lower right of the PCBA  9 . 
         [0065]    An effective movement range of the spray mechanism  7  must be larger than the maximum size (480 mm*360 mm) of the PCBA  9  from the spray starting position of the flux nozzle  79 . 
         [0066]    When the flow is changed, there is a difference of 180 degrees from the X-axis (direction of the crossbeam  73 ) origin of the original flow, corresponding to the spray starting position of the flux nozzle  79 . 
         [0000]    5. Angle-adjusting mechanism  4   
         [0067]    As shown in  FIG. 3 , the angle-adjusting mechanism  4  is provided below the top frame and comprises two sets of adjusting component, i.e., a left lifting column  41  and a right lifting column  42 , which are used to adjust a left height and a right height of the PCBA transfer tracks  1  respectively. When the left height is different from the right height, a certain angle is formed between the PCBA transfer track  1  and the horizontal plane, which can be adjusted in a range of 0˜10 degrees according to the practical requirement. The left lifting column  41  and the right lifting column  42  are two independent adjusting mechanisms. 
         [0068]    The angle adjustment is based on the following reasons. When the PCBA  9  is not perpendicular to the flux nozzle  79 , the process of spraying the flux will make the pressure acting on the PCBA  9  nonuniform and will produce a shadowing effect, thereby resulting in the nonuniform spray. As shown in  FIG. 10 , in the case of same spray pressure, the distance between the flux nozzle  79  and the PCBA  9  changes with the movement of the flux nozzle  79 . For example, referring to  FIG. 10 , h 1  is less than h 2 , and thus the spray pressure at a position of the PCBA  9  corresponding to h 1  is larger than that corresponding to h 2 . 
         [0069]    However, when the PCBA  9  is perpendicular to the flux nozzle  79 , the distance between the flux nozzle  79  and the PCBA  9  keeps constant with the movement of the flux nozzle  79 . For example, referring to  FIG. 11 , h 1  is equal to h 2 , and thus the spray pressures at positions of the PCBA  9  corresponding to h 1  and h 2  are equal to each other. Therefore, the nonuniform spray of the flux caused by the nonuniform spray pressure can be improved, and the penetrability of the flux in the through hole will be improved, as shown in  FIG. 11 . 
         [0070]    Thus, when the PCBA  9  is perpendicular to the flux nozzle  79 , the shadowing effect can be reduced and the quality of the flux spray can be improved. 
         [0071]    Furthermore, when there is a height difference between opposite ends of the PCBA transfer track due to the connection with the upstream and downstream equipments, a change of the angle between the PCBA  9  and the flux nozzle  79  will occur if there is no linkage between the spray mechanism  7  and the PCBA transfer track  1 . 
         [0072]    In order to adapt to the connection with the upstream and downstream equipments, the perpendicular state between the PCBA  9  and the flux nozzle  79  is kept by adjusting the angle in left-right direction of the PCBA transfer track  1  through the angle-adjusting mechanism  4 , and by the linkage between the PCBA transfer track  1  and the spray mechanism  7 . 
         [0073]    The left lifting column  41  and the right lifting column  42  have the same structures and are symmetrically arranged, and thus the right lifting column  42  will be described as an example. Two right lifting columns  42  are provided below a junction between the back top beam  24  and the right top beam  22  and below a junction between the front top beam  21  and the right top beam  22 , respectively. As shown in  FIGS. 8 and 12 , the right lifting column  42  below a right end of the back top beam  24  comprises a wedge-shaped base  43 , a connecting component  44  and a driving component  45 . A lifting mechanism, for example a thread-engaged lifting mechanism, is provided inside the wedge-shaped base  43 . 
         [0074]    The driving component  45  such as a hand wheel or a motor is used to provide a driving force to the lifting mechanism. A lower end of the connecting component  44  is sleeved on a top end of an output screw rod of the lifting mechanism, and an upper end of the connecting component  44  is hinged to a lug disposed on a lower surface at a right end of the back top beam  24 . When the right lifting column  42  is lifting, the perpendicular state of the connecting component  44  and the right top beam is changed to a non-perpendicular state. 
         [0075]    Two right lifting columns  42  are required to lift synchronously. The bottom of the output screw rod of each right lifting column  42  is sleeved on a gear, and the two gears of two right lifting columns  42  are connected with a timing chain  46  to ensure the synchronization between two right lifting columns  42 . 
         [0076]    In the operation of the left lifting column  41  and the right lifting column  42 , the back top beam  24  and the front top beam  21  on the top are driven first. The left top beam  23  and the right top beam  22  are also lifted due to the integral structure of the top frame. The fixing component  49 , the sliding component  48  and the central connecting component  28  in connection with the top frame drive the PCBA transfer track  1  to lift, thereby achieving the angle adjustment. The state after lifting the right end of the PCBA transfer track  1  is shown in  FIG. 12 . 
         [0077]    As the connecting plate  8  is in fixed and connected between the top frame and the spray mechanism  7 , when the height (angle) of the PCBA transfer track  1  is adjusted through the left lifting column  41  and the right lifting column  42 , there is a linkage between the spray mechanism  7  and the PCBA transfer track  1 , i.e., the spray mechanism  7  presents a same inclination angle corresponding to and the angle of the PCBA transfer track  1 . Thus, while the PCBA  9  is transferred by PCBA transfer track  1 , the flux nozzle  79  is kept in the perpendicular state, i.e., is kept to spray perpendicularly. 
         [0078]    The PCBA transfer track  1  may lift through both the left lifting column  41  and the right lifting column  42 . When the lifting height of the left lifting column  41  is equal to that of the right lifting column  42 , the lifted PCBA transfer track  1  is parallel to the horizontal plane, and the spray mechanism  7  is driven to keep parallel to the horizontal plane. 
         [0079]    According to exemplary embodiments, the top frame is fixed and connected to the primary longitudinal beam  72  and the secondary longitudinal beam  71  of the spray mechanism  7  through the connecting plate  8 , as a result, the plane of the top frame is kept relatively parallel to the plane of the primary longitudinal beam  72  and the secondary longitudinal beam  71  of the spray mechanism  7 . In addition, the PCBA transfer track  1  is fixed and connected to the top frame through the fixing component  49 , the sliding component  48  and the central connecting component  28 . Thus, the plane of the top frame can be kept relatively parallel to the plane of the PCBA transfer track  1 . As a result, the transfer plane of the PCBA transfer track  1  (the plane of the transferred PCBA  9 ) keeps relatively parallel to the spray plane of the spray mechanism  7  (the plane of various positions of the flux nozzle  79 ), such that the PCBA  9  keeps relatively perpendicular to the flux nozzle  79 , thereby avoiding the negative effect of the shadowing effect, effectively overcoming the non-uniformity of the flux spray, and improving the quality of solder. 
         [0080]    The beneficial effects of one or more embodiments of the present invention are described as followings. 
         [0081]    The present flux spray machine breaks through the limitation of the conventional mechanical structure, and thus the entire mechanical structure supports two-way flow (left-to-right or right-to-left). After the equipment is purchased, the flow may be set by oneself according to the site requirement and the track width may be adjusted corresponding to the size of the PCBA. 
         [0082]    Furthermore, as to the mechanical structure, each flow is set with a mechanical origin in consideration of the convenience for varying the flow and the repeating accuracy, thereby the simplicity and fool proof requirement is met and the faulty operation of the operator by mistake is avoided. The repeating accuracy of the operation is accurately improved through the compensation correction of the mechanical origin and the software origin. 
         [0083]    The purchased flux spray machine may be set by oneself with the flow according to any flow requirement of the production line, thereby the application flexibility of the equipment is greatly improved and the purchasing cost of the equipment is reduced. It is avoided that the equipment is idle and wasted due to unchangeable flow of the conventional flux spray machine. 
         [0084]    The single-direction movement of the nozzle is replaced with the X-Y table spray structure, thereby the spray structure is flexible to meet various spray requirements and the stable spray quality is achieved. 
         [0085]    Furthermore, in the present flux spray machine, the nozzle thereof is synchronously adjusted along with the angle of the PCBA transfer track to keep the nozzle perpendicular to PCBA, thereby the adverse effect from the shadowing effect is avoided and the solder quality is improved. 
         [0086]    While the invention has been described with reference to exemplary embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will comprise all embodiments falling within the scope of the appended claims.