Dual pump system and method for controlling wave solder contact length

Abstract

Providing a wave soldering machine, a method for adjusting the flow of solder waves, and a wave soldering station. [Solution] The wave soldering station of a wave soldering machine comprises a core frame supported by a flow conduit positioned within a solder pot reservoir, first and second pumps for delivering solder material to first and second chambers, and a wave soldering nozzle assembly supported by the core frame. The nozzle assembly comprises a solder distribution baffle for generating a solder wave, and an outlet vane coupled to the core frame and configured to move from a lowered position that can increase the solder flow and an elevated position that can decrease the flow of solder material. The first pump, the second pump, and the outlet vane are configured to control the flow of solder through the solder distribution baffle so as to vary the contact length of the solder wave.

Description

Technical Field

[0001] The present disclosure relates generally to apparatuses and methods for manufacturing printed circuit boards and apparatuses and methods for assisting a process of soldering metal to an integrated circuit board, and more particularly to a wave soldering machine having two pumps configured to control the flow of solder to a wave soldering nozzle assembly and an outlet wing configured to control the height of a solder wave, and related methods.

Background Art

[0002] In the manufacture of printed circuit boards, electronic components can be mounted on a printed circuit board by a process known as "wave soldering". In a conventional wave soldering machine, a conveyor moves a printed circuit board (sometimes referred to as a "PCB") through a flux application station, a preheating station, and finally a wave soldering station on an inclined path. In the wave soldering station, a wave of solder is ejected upward (by a pump) through a wave soldering nozzle and contacts the portion of the printed circuit board to be soldered.

[0003] Conventional wave soldering nozzles have nozzles configured to control the flow of solder generated by the wave soldering machine. The process of adjusting the solder flow can be difficult and risky for an operator tasked with performing such adjustments within a solder pot filled with molten solder. It is also desirable to minimize the dross created by the solder flow on the nozzle.

Summary of the Invention

[0004] One aspect of the present disclosure relates to a wave soldering machine for performing a wave soldering operation on a printed circuit board. In one embodiment, the wave soldering machine comprises a housing and a conveyor coupled to the housing. The conveyor is configured to deliver the printed circuit board through the housing. The wave soldering machine further comprises a wave soldering station coupled to the housing and the conveyor. The wave soldering station comprises a solder pot having a reservoir of solder material, a flow conduit positioned within the reservoir of the solder pot, and a core frame supported by the flow conduit. The core frame comprises a first chamber and a second chamber. The wave soldering station further comprises a first pump configured to deliver solder material to the first chamber, a second pump configured to deliver solder material to the second chamber, and a wave soldering nozzle assembly supported by the core frame. A wave soldering nozzle assembly includes a solder distribution baffle configured to generate a solder wave, and an outlet vane coupled to a core frame and configured to move from a lowered position that can increase the solder flow and an elevated position that can decrease the flow of solder material. The wave soldering machine further includes a controller coupled to the wave soldering station to control the operation of a first pump and a second pump, and to control the movement of the outlet vane to control the flow of solder through the solder distribution baffle to vary the contact length of the solder wave.

[0005] An embodiment of a wave soldering machine may further include a first pump impeller positioned in a flow conduit within a solder pot reservoir, and a second pump impeller positioned in a flow conduit within a solder pot reservoir. The flow of solder material in each of the two chambers can be controlled by the respective pump impellers of the two pump impellers. Each pump impeller of the two pump impellers may include a centrifugal pump that pumps solder material into a wave soldering nozzle assembly. Each of the two chambers may have an inlet connected to its respective pump impeller. Each pump impeller of the two pump impellers may be coupled to a controller to control the flow of solder material provided by the pump impeller. The controller can control the first pump impeller to deliver solder material through the first chamber to the input side of a solder distribution baffle, and the controller can control the second pump impeller to deliver solder material through the second chamber to the discharge side of a solder distribution baffle. The controller may be configured to operate a first pump impeller and activate an outlet vane actuator to move the outlet vane to a lowered position to provide a minimum contact length for the solder wave, and to operate the first and second pump impellers and activate an outlet vane actuator to move the outlet vane to an elevated position to provide a maximum contact length for the solder wave. The outlet vane may be rotatable around a hinge relative to the core frame to move the outlet vane between the lowered and elevated positions. The wave soldering nozzle assembly may further include an outlet vane actuator connected to the outlet vane and coupled to the controller. The outlet vane actuator may be configured to adjust the position of the outlet vane between the lowered and elevated positions. The outlet vane actuator may be connected to the outlet vane by a linkage mechanism. The linkage mechanism may include at least one rotary link having a first end rotatably coupled to the end of the outlet vane and a second end rotatably coupled to the actuator arm of the outlet vane actuator.

[0006] Another aspect of the present disclosure relates to a method for regulating the flow of a solder wave in a wave soldering nozzle assembly of a wave soldering machine. In one embodiment, the method includes: delivering solder material to a wave soldering nozzle assembly comprising a solder distribution baffle; selectively delivering the solder material to a portion of the solder distribution baffle to produce a solder wave of a desired width by selectively controlling two pumps positioned in a flow conduit in a solder pot reservoir and fluidly communicating with each chamber along the width of the solder distribution baffle; regulating the flow of the solder wave using an outlet vane actuator coupled to the outlet vane to adjust the position of the outlet vane; and performing a wave soldering operation on a printed circuit board.

[0007] Embodiments of the method may further include controlling a first pump associated with a first chamber of the nozzle core frame of a wave soldering nozzle assembly, and controlling a second pump associated with a second chamber of the nozzle core frame of a wave soldering nozzle assembly. The first pump and the first chamber may be configured to deliver solder material to the input side of a solder distribution baffle, and the second pump and the second chamber may be configured to deliver solder material to the discharge side of a solder distribution baffle. The first pump, the second pump, and the outlet vane actuator may be controlled by a controller. The controller may be configured to operate the first pump and activate the outlet vane actuator to move the outlet vane to a lowered position to provide a minimum contact length of solder wave, and to operate the first pump and the second pump and activate the outlet vane actuator to move the outlet vane to an raised position to provide a maximum contact length of solder wave.

[0008] A further aspect of the present disclosure relates to a wave soldering station for a wave soldering machine configured to perform a wave soldering operation on a printed circuit board. In one embodiment, the wave soldering station comprises a solder pot having a reservoir of solder material, a flow conduit positioned within the reservoir of the solder pot, and a core frame supported by the flow conduit. The core frame comprises a first chamber and a second chamber. The wave soldering station further comprises a first pump configured to deliver solder material to the first chamber, a second pump configured to deliver solder material to the second chamber, and a wave soldering nozzle assembly supported by the core frame. The wave soldering nozzle assembly comprises a solder distribution baffle configured to generate a solder wave, and an outlet vane coupled to the core frame and configured to move from a lowered position that can increase the flow of solder and an elevated position that can decrease the flow of solder material. The first pump, the second pump, and the outlet vane are configured to control the flow of solder through the solder distribution baffle to vary the contact length of the solder wave.

[0009] Embodiments of a wave soldering station may further include a first pump impeller positioned within a flow conduit in a solder pot reservoir, and a second pump impeller positioned within a flow conduit in a solder pot reservoir. The flow of solder material in each of the two chambers can be controlled by the respective pump impellers of the two pump impellers. The first pump impeller and the first chamber may be configured to deliver solder material to the input side of a solder distribution baffle. The second pump impeller and the second chamber may be configured to deliver solder material to the discharge side of a solder distribution baffle. The operation of the first pump impeller and the movement of the outlet blades to the lowered position can provide a minimum contact length of the solder wave, and the operation of the first and second pump impellers and the movement of the outlet blades to the raised position can provide a maximum contact length of the solder wave.

[0010] The attached drawings are not intended to be drawn to exact scale. In the drawings, each identical or nearly identical component shown in each drawing is represented by the same reference numeral. For clarity, not all components are labeled in all drawings. [Brief explanation of the drawing]

[0011] [Figure 1] This is a perspective view of a wave soldering machine. [Figure 2] This is a side view of a wave soldering machine, with the outer packaging removed to reveal the internal components of the wave soldering machine. [Figure 3] This is a perspective view of a wave soldering station according to one embodiment of the present disclosure. [Figure 4] This is a disassembled perspective view of a wave soldering station. [Figure 5] This is a cross-sectional perspective view of a wave soldering station. [Figure 6]This is a cross-sectional view of a wave soldering station showing the exit wing in a descending position. [Figure 7] This is a cross-sectional view of a wave soldering station showing the exit wing in the upward position. [Figure 8] This is an exploded perspective view of the wave soldering nozzle assembly of a wave soldering station. [Figure 9] This is a magnified cross-sectional view of a wave soldering nozzle assembly showing the minimum contact length. [Figure 10] This is a magnified cross-sectional view of a wave soldering nozzle assembly showing the maximum contact length. [Modes for carrying out the invention]

[0012] This disclosure is not limited to the structural and arrangement details of the components shown in the following description or drawings, which may be used for applications. Other embodiments of this disclosure are possible and can be implemented or performed in various ways. The terms and technical terms used herein are for illustrative purposes only and should not be considered limiting. The use of “including,” “comprising,” “having,” “containing,” “involving,” and their variations herein is intended to include additional items, along with the items listed above and their equivalents.

[0013] Embodiments of the present disclosure relate to controlling the flow of molten solder on a nozzle to vary the width and height of the solder wave. One objective is to provide the ability to adjust (reduce) the width of the solder wave in order to reduce the dross produced by the solder wave. A further objective is to automate this adjustment and enable computer control to eliminate the need for human intervention when adjustment is required based on the product being processed.

[0014] For illustrative purposes, with reference to Figure 1, embodiments of the present disclosure are described below with respect to a wave soldering machine, shown collectively as 10, used for applying solder to printed circuit boards 12. The wave soldering machine 10 is one of several machines in a printed circuit board manufacturing / assembly line. As shown, the wave soldering machine 10 includes a housing or frame 14 adapted to accommodate the machine's components. A conveyor 16 is configured to deliver the printed circuit boards 12 to be processed by the wave soldering machine 10. Upon entering the wave soldering machine 10, each printed circuit board 12 moves along an inclined path (e.g., 6 degrees to the horizontal) along the conveyor 16 through a tunnel 18, which includes a flux application station, shown collectively as 20, and a preheating station, shown collectively as 22, to prepare the printed circuit board 12 for wave soldering. Once prepared (i.e., heated), the printed circuit board 12 moves to a wave soldering station, shown collectively as 24, which applies solder material to the printed circuit board 12. A controller 26 is provided to automate the operation of several stations of the wave soldering machine 10, including, but not limited to, a flux application station 20, a preheating station 22, and a wave soldering station 24, in a known manner.

[0015] Referring to Figure 2, the flux application station 20 is configured to apply flux to the printed circuit board 12 as it moves along the conveyor 16 through the wave soldering machine 10. The preheating station includes several preheaters (e.g., preheaters 22a, 22b, and 22c) which are designed to gradually raise the temperature of the printed circuit board 12 as it moves along the conveyor 16 through the tunnel 18 to prepare it for the wave soldering process. As shown in the figure and as will be described in more detail later, the wave soldering station 24 includes a wave soldering nozzle assembly that is in fluid communication with a solder material reservoir. A pump is provided in the reservoir to deliver molten solder material from the reservoir to the wave soldering nozzle assembly. Once soldered, the printed circuit board 12 moves from the wave soldering machine 10 via the conveyor 16 to another station on the production line, such as a pick-and-place machine.

[0016] In some embodiments, the wave soldering machine 10 may further include a flux management system, shown collectively as 28, which removes volatile contaminants from the tunnel 18 of the wave soldering machine. As shown in Figure 2, the flux management system 28 is located below the preheating station 22. In one embodiment, the flux management system is supported by a housing 14 within the wave soldering machine and is in fluid communication with the tunnel 18, which is schematically shown in Figure 2. The flux management system 28 is configured to receive contaminated gas from the tunnel 18, process the gas, and return clean gas to the tunnel. The flux management system 28 is particularly configured to remove volatile contaminants from the gas, especially in an inert atmosphere.

[0017] Embodiments of this disclosure relate to minimizing dross associated with molten solder. Different combinations of tin, lead, and other metals are used to produce lead-based and lead-free solders. Dross is a mass of solid impurities that floats on the surface of the molten solder or is dispersed within the molten solder. In the case of solder, dross tends to form on the surface of the tin-based molten metal, and oxidized impurities create dross.

[0018] Referring to Figures 3 to 7, the wave soldering station 24 comprises a solder pot 30 defining a reservoir 32 configured to contain molten solder. In one embodiment, the solder pot 30 is a box-shaped structure supporting the components of the wave soldering station 24, including a flow conduit 34 having two chambers within the reservoir 32. As shown, a partition plate 36 is provided within the flow conduit 34 to create a first chamber 38 and a second chamber 40. One or more cross partition plates (not specified) may be provided to separate the respective chambers 38, 40. For example, two cross partition plates may be provided to separate the first chamber 38 and the second chamber 40 and include three passages. The flow conduit 34 is designed to deliver pressurized molten solder to the opening or nozzle of a wave soldering nozzle assembly, shown collectively as 42. The wave soldering nozzle assembly 42 is configured to transport molten solder to the bottom of the printed circuit board 12, enabling a smooth flow of solder back to the reservoir 32. Specifically, the wave soldering nozzle assembly 42 is capable of adjusting the width and height of the solder wave when performing the wave soldering operation.

[0019] Referring further to FIG. 8, the wave soldering nozzle assembly 42 includes a nozzle core frame 44 having two end walls 46, 48 and a first longitudinal support element 50 and a second longitudinal support element 52 extending between the end walls 46, 48. As shown, the nozzle core frame 44 can further include several transverse support elements, each indicated at 54, that extend between the first longitudinal support element 50 and the second longitudinal support element 52. Also, the nozzle core frame 44 guides the solder flow through a nozzle throat defined between the first longitudinal support element 50 and the second longitudinal support element 52. The wave soldering nozzle assembly 42 further includes an elongated solder distribution baffle 56 fixed to the first longitudinal support element 50 and the second longitudinal support element 52 of the nozzle core frame 44. The solder distribution baffle 56 is fixed to the first longitudinal support element 50 and the second longitudinal support element 52 by screws passing through openings provided along the sides of the solder distribution baffle 56. In one embodiment, the solder distribution baffle 56 has a unique pattern of elongated openings to allow molten solder to flow through the solder distribution baffle 56.

[0020] The partition plate 36 extends through the nozzle core frame 44 and extends the first chamber 38 and the second chamber 40 to the solder distribution baffle 56. In the illustrated embodiment, the molten solder material is delivered to the input side of the solder distribution baffle 56 via the first chamber 38, and the molten solder material is delivered to the discharge side of the solder distribution baffle 56 via the second chamber 40. As will be described in more detail below, the amount of molten solder material can be controlled by delivering the molten solder material to one or both of the first chamber 38 and the second chamber 40.

[0021] The wave soldering station 24 further comprises a first pump impeller 58 and a second pump impeller 60, which are two pump impellers positioned within a flow conduit 34 in a reservoir 32 of a solder pot 30. As used herein, the pump impellers 58 and 60 may also be referred to as pumps. The first pump impeller 58 and the second pump impeller 60 pressurize the molten solder in the flow conduit 34 and pump the molten solder vertically through the respective first chamber 38 and second chamber 40 and the wave soldering nozzle assembly 42. In one embodiment, each pump impeller 58, 60 is a centrifugal pump of a suitable size for pumping the molten solder to the nozzle of the wave soldering nozzle assembly 42. The wave soldering nozzle assembly 42 generates solder waves provided for mounting components onto the circuit board 12 in the manner described below and is configured to optimize the contact length over which the solder waves contact the printed circuit board 12 during processing.

[0022] As described above, the flow conduit 34 includes two chambers 38, 40. Each chamber 38, 40 includes an inlet channel connected to its respective pump impeller 58, 60. In the illustrated example, the first pump impeller 58 is connected to the first chamber 38 by the first inlet channel 62, and the second pump impeller 60 is connected to the second chamber 40 by the second inlet channel 64. Thus, the flow of molten solder to the solder distribution baffle 56 is controlled by controlling the first pump impeller 58 and the second pump impeller 60. The flow of molten solder through the first chamber 38 and the second chamber 40 can be independently controlled by the controller 26 by controlling the pump impellers 58, 60 respectively, and the controller 26 is coupled to or otherwise connected to the pump impellers 58, 60. For example, by operating only the first pump impeller 58, molten solder is delivered to the input side of the solder distribution baffle 56 through the first chamber 38 to reduce the width of the solder wave. In another example, by operating the first pump impeller 58 and the second pump impeller 60, molten solder is delivered to the input side of the solder distribution baffle 56 through the first chamber 38 and also to the discharge side of the solder distribution baffle 56 to increase the width of the solder wave. Thus, as a result, the solder wave can be controlled by operating the first pump impeller 58 and the second pump impeller 60.

[0023] As best shown in FIGS. 6 and 7, an inert atmosphere surrounding the solder wave can be created by providing one or more nitrogen tubes for creating an inert atmosphere during the wave soldering process. As shown, two nitrogen tubes, each indicated at 66, are provided adjacent to the nozzle core frame 44 and below the solder distribution baffle 56. Additional nitrogen or gas diffuser tubes can be provided in the space above the solder distribution baffle 56 and below the cover (not shown) of the wave soldering nozzle assembly 42.

[0024] Referring again to Figures 3 to 7, the wave soldering nozzle assembly 42 further comprises an outlet vane 68 for controlling the solder flow over the rear of the nozzle of the solder wave generated by the wave soldering machine 10. To allow adjustment of the solder wave flow exiting the nozzle of the wave soldering nozzle assembly 42, the outlet vane 68 is hinged to the second longitudinal side wall 52 of the nozzle core frame 44 by a hinge 70. The outlet vane 68 is rotatable around the hinge 70 by an actuator 72 via a linkage mechanism. The actuator 72 may also be referred to herein as the outlet vane actuator. The position of the outlet vane 68 relative to the nozzle core frame 44 can be controlled in real time by controlling the longitudinal displacement of the actuator arm 74 of the actuator, and thus the solder wave flow over the rear of the nozzle can be decreased or increased by raising and lowering the outlet vane 68, respectively.

[0025] The actuator 72 is fixed to the solder pot 30 by an actuator support frame 76, and the actuator support frame 76 is fixed to the side wall of the solder pot 30 by suitable fasteners such as bolts. Alternatively, the actuator support frame 76 may be fixed to the solder pot 30 by another method such as welding or riveting. As shown in the figure, the actuator 72 is fixed to the actuator support frame 76, and the actuator support frame 76 is configured to firmly support the actuator 72 with respect to the solder pot 30. The actuator 72 is positioned next to the wave soldering nozzle assembly 42 and constitutes part of the assembly for adjusting the position of the outlet blade 68 of the wave soldering nozzle assembly 42 relative to the nozzle core frame 44 via a link mechanism coupled to the outlet blade 68 and the actuator 72. The actuator 72 includes an actuator arm 74 coupled to the link mechanism by an actuator block 78. The link mechanism will be described in more detail below.

[0026] In one embodiment, the actuator 72 is a linear actuator, and therefore the actuator arm 74 moves longitudinally. The actuator block 78 transmits movement from the actuator arm 74 to the exit wing 68 by connecting the actuator arm 74 to two connecting links, each indicated by 80. Thus, as the actuator arm 74 moves longitudinally, the actuator block 78 and the connecting links 80 move in the same longitudinal direction as the actuator arm 74. In some embodiments, the actuator 72 and the connecting links 80 are oriented such that the actuator arm 74 moves the connecting links 80 horizontally. In a particular embodiment, the actuator 72 includes an electromechanical actuator that provides movement for adjusting the position of the exit wing 68. The actuator 72 is driven by computer-controlled mechanical software (supported by a controller 26) and incorporates an encoder that can relay position instructions to the mechanical software. The actuator 72 can be controlled in real time via the controller 26 to achieve a desired position of the exit wing 68. The controller 26 communicates with the actuator 72 and is configured to cause the actuator 72 to adjust the position of the exit blade 68 while the wave soldering machine 10 is in operation. The actuator 72 is configured to receive commands from the controller 26 to adjust the position of the exit blade 68 while the wave soldering machine 10 is in operation.

[0027] In one embodiment, the outlet wing 68 comprises a first end coupled to a second longitudinal side wall 52 of the nozzle core frame 44 by a hinge 70, and a second end coupled to an actuator 72 via a rotating link 82 of a link mechanism, so that the actuator 72 can rotate the second end of the outlet wing 68 around the hinge 70 of the first end of the outlet wing 68. Rotating the outlet wing 68 around the hinge 70 changes the flow of solder waves passing over the outlet wing 68. In particular, rotating the outlet wing 68 so that the second end of the outlet wing 68 moves upward to an elevated position reduces the flow of solder waves over the outlet wing 68, and rotating the outlet wing 68 so that the second end of the outlet wing 68 moves downward to a lowered position increases the flow of solder waves over the outlet wing 68.

[0028] As described above, the link mechanism allows the actuator 72 to adjust the position of the outlet blade 68 relative to the nozzle core frame 44. In particular, the link mechanism allows the actuator arm 74 of the actuator 72 to be moved longitudinally to adjust the angle of the upper surface of the outlet blade 68 with respect to the horizontal. In one embodiment, the link mechanism comprises a connecting link 80, a rotating link 82, and a crossbar 84. The rotating link 82 is coupled to the second end of the outlet blade 68 by the crossbar 84, and the crossbar 84 is coupled to the actuator block 78 by the connecting link 80.

[0029] The rotating link 82 has a first end rotatably coupled to the second end of the exit blade 68 and a second end rotatably coupled to the crossbar 84. The crossbar 84 extends perpendicularly to the rotating link 82. Each connecting link 80 has a first end coupled to the crossbar 84 and a second end coupled to the actuator block 78. The connecting links 80 extend perpendicularly to the crossbar 84 and parallel to the actuator arm 74. When the upper surface of the exit blade 68 extends substantially horizontally, the crossbar 84 is located below the exit blade 68 and longitudinally between the first end and the second end of the exit blade 68.

[0030] The longitudinal displacement of the actuator arm 74 allows the outlet blade 68 to rotate around the hinge 70. The axial direction of the actuator arm 74 is parallel to the axial direction of the connecting link 80. Therefore, the actuator arm 74 is configured to move the connecting link 80 horizontally along the axis in the direction of the actuator arm 74. Since the crossbar 84 is coupled to the connecting link 80, the extension or contraction of the actuator arm 74 causes the crossbar 84 to translate. Since the rotating link 82 is rotatably coupled to the crossbar 84 and the actuator 72 and wave soldering nozzle assembly 42 are fixed to the solder pot 30, the translation of this crossbar 84 causes the outlet blade 68 to rotate.

[0031] Referring again to Figures 9 and 10, the actuator arm 74 is in the extended position in Figure 9 and in the retracted position in Figure 10. The second end of the outlet blade 68 is shown in Figure 9 in a lower position (lowered position) than in Figure 10 (upper position). The back gate 86 is fixed to the second end of the outlet blade 68. In addition to being configured to operate the first pump impeller 58 and the second pump impeller 60, the controller 26 is configured to operate the actuator 72 to adjust the orientation of the outlet blade 68 to change the solder flow over the back gate 86 of the outlet blade 68. Thus, the controller 26 is configured to achieve optimal soldering characteristics of the wave soldering nozzle assembly 42. Optimal soldering characteristics are achieved when there is no flow over the back gate 86 of the outlet blade 68 when the conveyor 16 is not carrying components to be soldered, such as a printed circuit board 12, onto the wave soldering assembly. However, when the printed circuit board 12 being carried by the conveyor 16 enters the solder wave indicated by the dashed line 88 in Figures 9 and 10, the solder moves along the conveyor 16 at a speed V of the printed circuit board 12. pcbThe solder begins to flow over the back gate 86 of the exit blade 68 at the same speed. Once the printed circuit board 12 exits the solder wave 88, the solder flow over the back gate 86 of the exit blade 68 stops again.

[0032] The orientations of the exit vane 68 shown in Figures 9 and 10 are just two examples of the possible orientations of the exit vane 68. The rotation range of the exit vane can be selected according to desired performance parameters of the system, such as a desired solder wave height range. In various embodiments, the rotation range of the exit vane 68 may extend beyond the orientations shown in Figures 9 and 10.

[0033] To achieve the minimum contact length L1 shown in Figure 9, the first pump impeller 58 operates at a high revolutions per minute (RPM) to create an increased flow of molten solder material through the input side of the solder distribution baffle 56, and the second pump impeller 60 operates at a low RPM to create a decreased flow of molten solder material through the discharge side of the solder distribution baffle 56, with the outlet blade 68 being lowered. To achieve the maximum contact length L2 shown in Figure 10, the first pump impeller 58 operates at a high RPM to create an increased flow of molten solder material through the input side of the solder distribution baffle 56, and the second pump impeller 60 operates at a high RPM to create an increased flow of molten solder material through the discharge side of the solder distribution baffle 56, with the outlet blade 68 being raised to adapt to the increased flow of molten solder material on the outlet blade 68. The contact length of the solder wave 88 can be manipulated by the operation of the pump impellers 58, 60 and the outlet blades 68 to achieve a desired contact length between the minimum contact length L1 and the maximum contact length L2.

[0034] The above description of solder flow relates to the printed circuit board 12 carried by the conveyor 16, but a similar solder flow occurs for other components to be soldered that are carried by the conveyor 16 onto the wave soldering nozzle assembly 42.

[0035] Embodiments of the present disclosure relate to a method for regulating the flow of a solder wave 88 in a wave soldering nozzle assembly 42 of a wave soldering machine 10. In one embodiment, the method includes delivering molten solder material to a wave soldering nozzle assembly 42 having a solder distribution baffle 56, and selectively delivering the molten solder material to multiple portions of the solder distribution baffle 56 to produce a solder wave 88 having a desired width by selectively controlling two pump impellers 58, 60 positioned in a flow conduit in a reservoir 32 of a solder pot 30 and fluidly communicating with their respective chambers 38, 40 along the width of the solder distribution baffle 56. The method further includes regulating the flow of the solder wave 88 by an outlet wing actuator 72 coupled to an outlet wing 68 to adjust the position of the outlet wing 68, and performing a wave soldering operation on a printed circuit board 12. It should be noted that selectively controlling the two pump impellers 58 and 60 includes controlling the first pump impeller 58 associated with the first chamber 38 of the nozzle core frame 44 of the wave soldering nozzle assembly 42, and controlling the second pump impeller 60 associated with the second chamber 40 of the nozzle core frame 44 of the wave soldering nozzle assembly 42. The first pump impeller 58 and the first chamber 38 are configured to deliver solder material to the input side of the solder distribution baffle 56, and the second pump impeller 60 and the second chamber 40 are configured to deliver solder material to the discharge side of the solder distribution baffle 56. The first pump impeller 58, the second pump impeller 60, and the outlet vane actuator 72 are controlled by the controller 26. This configuration is such that the controller 26 operates the first pump impeller 58 and the outlet blade actuator 72 to move the outlet blade 68 to the lowered position to provide the minimum contact length L1 of the solder wave 88, and also operates the first pump impeller 58 and the second pump impeller 60 and the outlet blade actuator 72 to move the outlet blade 68 to the raised position to provide the maximum contact length L2 of the solder wave 88.

[0036] Various controllers can perform the various operations discussed above. For example, as discussed above, a controller such as controller 26 can, among other operations, control components of the wave soldering machine 10, including the wave soldering station 24. Using data stored in associated memory and / or storage, the controller can execute one or more instructions stored in one or more non-temporary computer-readable media that the controller may have and / or be coupled with, thereby manipulating the data. In some examples, the controller may include one or more processors or other types of controllers. In one example, the controller is or includes at least one processor. In another example, the controller uses, in addition to or instead of a general-purpose processor, an application-specific integrated circuit tuned to perform a particular operation to perform at least some of the operations discussed above. As these examples illustrate, the examples provided herein can perform the operations described herein using many specific combinations of hardware and software, and the disclosure is not limited to any specific combination of hardware and software components. The examples provided herein may include computer program products configured to perform the methods, processes, and / or operations discussed above. A computer program product may be, or may include, one or more controllers and / or processors configured to execute instructions for performing the methods, processes, and / or actions discussed above.

[0037] According to each embodiment, the solder flow through the nozzle can be controlled to reduce and even prevent the recirculation of dross through the nozzle. Dross is reduced by reducing the width of the solder wave. Each embodiment makes it possible to reduce the width of the solder wave.

[0038] In some embodiments, the wave soldering nozzle assembly further comprises a dross box, which is fixed to the nozzle frame and configured to further reduce solder balls that may form in the reservoir by reducing disturbance as the solder returns to the reservoir.

[0039] In some embodiments, one or more nitrogen tubes can be provided to create an inert atmosphere during the wave soldering process.

[0040] In some embodiments, the minimum and maximum contact can be varied.

[0041] As used herein, “solder wave width” describes the actual cross-sectional dimensions of a solder wave, and “contact length” describes the distance on the printed circuit board that is in contact with the wave at any given time. As used herein, the term “length” refers to the contact length parallel to the direction of movement of the printed circuit board.

[0042] While several aspects of at least one embodiment of this disclosure have been described, it should be understood that various modifications, changes, and improvements will readily come to mind for those skilled in the art. Such modifications, changes, and improvements are intended to be part of this disclosure and to be within the spirit and scope of this disclosure. Accordingly, the above descriptions and drawings are merely illustrative.

Claims

1. A wave soldering machine that performs a wave soldering operation on a printed circuit board, Housing and A conveyor coupled to the housing, configured to deliver printed circuit boards through the housing, A wave soldering station coupled to the housing and the conveyor, A soldering pot having a reservoir for soldering material, A flow conduit positioned within the reservoir of the solder pot, A core frame supported by the flow conduit, comprising a first chamber and a second chamber, A first pump configured to deliver solder material to the first chamber, A second pump configured to deliver solder material to the second chamber, A wave soldering nozzle assembly supported by the core frame, comprising: a solder distribution baffle configured to generate a solder wave; and an outlet vane coupled to the core frame, configured to move from a lowered position that can increase the solder flow and an elevated position that can decrease the solder material flow; A wave soldering station equipped with, A controller coupled to the wave soldering station to control the operation of the first pump and the second pump, and to control the movement of the outlet vane to control the flow of solder through the solder distribution baffle to change the contact length of the solder wave, A wave soldering machine equipped with [a specific feature / feature].

2. The wave soldering machine according to claim 1, wherein the first pump includes a first pump impeller positioned within the flow conduit in the reservoir of the solder pot, and the second pump includes a second pump impeller positioned within the flow conduit in the reservoir of the solder pot.

3. The wave soldering machine according to claim 2, wherein the flow of the solder material in each of the first and second chambers is controlled by the respective pump impellers of the first and second pump impellers.

4. The wave soldering machine according to claim 3, wherein each of the first and second pump impellers includes a centrifugal pump for pressurizing the solder material to the wave soldering nozzle assembly.

5. The wave soldering machine according to claim 3, wherein each of the first and second chambers is provided with an inlet connected to its respective pump impeller.

6. The wave soldering machine according to claim 3, wherein each of the first and second pump impellers is coupled to the controller to control the flow of the solder material provided by the pump impellers.

7. The wave soldering machine according to claim 3, wherein the controller controls the first pump impeller to deliver solder material through the first chamber to the input side of the solder distribution baffle, and the controller controls the second pump impeller to deliver solder material through the second chamber to the discharge side of the solder distribution baffle.

8. The wave soldering machine according to claim 7, wherein the controller is configured to operate the first pump impeller and the outlet blade actuator to move the outlet blade to the lowered position in order to provide the minimum contact length of the solder wave, and to operate the first pump impeller and the second pump impeller and the outlet blade actuator to move the outlet blade to the raised position in order to provide the maximum contact length of the solder wave.

9. The wave soldering machine according to claim 1, wherein the outlet blade is rotatable about a hinge relative to the core frame in order to move the outlet blade between the lowered position and the raised position.

10. The wave soldering nozzle assembly further comprises an outlet wing actuator connected to the outlet wing and coupled to the controller, wherein the outlet wing actuator is configured to adjust the position of the outlet wing between the lowered position and the raised position, according to claim 9.

11. The wave soldering machine according to claim 10, wherein the outlet blade actuator is connected to the outlet blade by a link mechanism, and the link mechanism includes at least one rotary link having a first end rotatably coupled to the end of the outlet blade and a second end rotatably coupled to the actuator arm of the outlet blade actuator.

12. A method for adjusting the solder wave flow of a wave solder nozzle assembly in a wave soldering machine, To deliver solder material to a wave soldering nozzle assembly equipped with a solder distribution baffle, Two pumps positioned within a flow conduit in the reservoir of a solder pot, selectively controlling the two pumps, each in fluid communication with its respective chamber along the width of the solder distribution baffle, to selectively deliver solder material to a portion of the solder distribution baffle in order to produce a solder wave of a desired width. To adjust the position of the outlet wing, an outlet wing actuator coupled to the outlet wing is used to adjust the flow of the solder wave, Performing a wave soldering operation on a printed circuit board, Methods that include...

13. The method according to claim 12, wherein selectively controlling two pumps includes controlling a first pump associated with a first chamber of the nozzle core frame of the wave soldering nozzle assembly and controlling a second pump associated with a second chamber of the nozzle core frame of the wave soldering assembly.

14. The method according to claim 13, wherein the first pump and the first chamber are configured to deliver solder material to the input side of the solder distribution baffle, and the second pump and the second chamber are configured to deliver solder material to the discharge side of the solder distribution baffle.

15. The method according to claim 13, wherein the first pump, the second pump, and the outlet vane actuator are controlled by a controller.

16. The method according to claim 15, wherein the controller is configured to operate the first pump and the outlet vane actuator to move the outlet vane to provide the minimum contact length of the solder wave, and to operate the first pump and the second pump and the outlet vane actuator to move the outlet vane to provide the maximum contact length of the solder wave.

17. A wave soldering station for a wave soldering machine configured to perform wave soldering operations on a printed circuit board, A soldering pot having a reservoir for soldering material, A flow conduit positioned within the reservoir of the solder pot, A core frame supported by the flow conduit, comprising a first chamber and a second chamber, A first pump configured to deliver solder material to the first chamber, A second pump configured to deliver solder material to the second chamber, A wave soldering nozzle assembly supported by the aforementioned core frame, A solder distribution baffle configured to generate a solder wave, An outlet vane coupled to the core frame, configured to move from a lowered position that can increase the flow of solder and an elevated position that can decrease the flow of solder material, A wave soldering nozzle assembly comprising, Equipped with, The first pump, the second pump, and the outlet vane are configured to control the flow of solder through the solder distribution baffle in order to change the contact length of the solder wave. Wave soldering station.

18. The wave soldering station according to claim 17, wherein the first pump includes a first pump impeller positioned in the flow conduit within the reservoir of the solder pot, and the second pump includes a second pump impeller positioned in the flow conduit within the reservoir of the solder pot, and the flow of the solder material in each of the first and second chambers is controlled by the respective pump impellers of the first and second pump impellers.

19. The wave soldering station according to claim 18, wherein the first pump impeller and the first chamber are configured to deliver solder material to the input side of the solder distribution baffle, and the second pump impeller and the second chamber are configured to deliver solder material to the discharge side of the solder distribution baffle.

20. The wave soldering station according to claim 19, wherein the operation of the first pump impeller and the movement of the outlet vane to the lowered position provide the minimum contact length of the solder wave, and the operation of the first and second pump impellers and the movement of the outlet vane to the raised position provide the maximum contact length of the solder wave.

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