Patent Publication Number: US-2021165430-A1

Title: Systems and methods for dispensing multi-component materials

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Patent App. No. 62/656,967, filed Apr. 12, 2018, the disclosure of which is hereby incorporated in its entirety by reference herein. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates generally to dispensing multi-component liquid materials and, more particularly, to systems and methods for precisely controlling the dispensing of multi-component liquid materials to a substrate. 
     BACKGROUND 
     In manufacturing of e.g., printed circuit boards (“PCBs”) it is frequently necessary to apply small amounts of vicious materials. Such materials include, for example, general purpose adhesives, solder paste, solder flux, solder mask, grease, oil, encapsulates, potting compounds, epoxies, die attach pastes, silicones, RTV, cyanoacrylates. There exists known methods for automatic control of dispensing of precise amounts of single component materials. Nevertheless, there exists a need for automatic precise control of dispensing amounts and/or ratios for multi-component dispensing operations. 
     SUMMARY 
     Disclosed herein are systems and methods for dispensing a mixed material onto a substrate. In one embodiment, a method for dispensing a mixed material, which includes at least a first material and a second material, onto a substrate, includes receiving dispensing operating parameters. The method also includes dispensing a first material from a first pump at a first material flow rate and determining an amount of the first material dispensed. The method also includes dispensing a second material from a second pump at a second material flow rate and determining an amount of the second material dispensed. The method also includes automatically adjusting dispensing of the first material to an adjusted first material flow rate and dispensing of the second material to an adjusted second material flow rate based on the determined amounts of the first and second materials dispensed. The method also includes pumping the first material from the first pump at the adjusted first material flow rate. The method also includes pumping the second material from the second pump at the adjusted second material flow rate. The method also includes mixing the first material and the second material within a chamber of a mixer to form the mixed material. The method also includes dispensing the mixed material from a dispensing nozzle onto the substrate. 
     In another embodiment, a dispense system for dispensing a mixed material, which includes at least a first material and a second material, onto a substrate includes a first supply that is configured to contain the first material. The dispense system also includes a second supply that is configured to contain the second material and a pump system. The pump system includes a first pump having an inlet in fluid communication with the first supply and an outlet, the first pump being configured to pump the first material from the first supply through the outlet of the first pump at a first material flow rate. The pump system also includes a second pump having an inlet in fluid communication with the second supply and an outlet, the second pump being configured to pump the second material from the second supply through the outlet of the second pump at a second material flow rate. The dispense system also includes a mixer that is configured to be connected to the pump system and that includes a first inlet that is configured to be in fluid communication with the outlet of the first pump, a second inlet that is configured to be in fluid communication with the outlet of the second pump, and a chamber configured to mix the first material and the second material therein. The dispense system also includes a dispensing nozzle in fluid communication with the chamber, the dispensing nozzle being configured to dispense the mixed material. The dispense system also includes a sensor that is configured to determine an amount of the first material dispensed and an amount of a second material dispensed. The dispense system also includes a controller that is configured to determine an operating mix ratio of the first material and the second material based on the determined amount of the first material dispensed and the determined amount of the second material dispensed, to determine that the operating mix ratio is outside of a predetermined ratio control range, and to adjust the first material flow rate to an adjusted first material flow rate and the second material flow rate to an adjusted second material flow rate to control operation of the first and second pumps to dispense the mixed material from the dispensing nozzle onto the substrate. 
     In yet another embodiment, a dispense system for dispensing a mixed material, which includes at least a first material and a second material, onto a substrate, includes a first supply that is configured to contain the first material and a second supply that is configured to contain the second material. The dispense system also includes a pump system including a first inlet in fluid communication with the first supply and a first outlet, and a second inlet in fluid communication with the second supply and a second outlet, the pump system being configured to pump the first material from the first supply through the first outlet at a first material flow rate and to pump the second material from the second supply through the second outlet at a second material flow rate. The dispense system also includes a mixer having a first inlet that is configured to be in fluid communication with the first supply, a second inlet that is configured to be in fluid communication with the second supply, and a chamber configured to mix the first material and the second material therein. The dispense system also includes a dispensing nozzle in fluid communication with the chamber, the dispensing nozzle being configured to dispense the mixed material. The dispense system also includes a sensor that is configured to determine an amount of the mixed material dispensed from the dispensing nozzle. The dispense system also includes a controller that is configured to control operation of the pump system based on the mixed material amount received from the sensor by automatically adjusting the first material flow rate to an adjusted first material flow rate and the second material flow rate to an adjusted second material flow rate based on the mixed material amount to dispense the mixed material from the dispensing nozzle onto the substrate. 
     In another embodiment, a method for dispensing a mixed material, which includes at least a first material and a second material, onto a substrate, includes receiving dispensing operating parameters. The method also includes calculating a target flow rate for a first material and a target flow rate for a second material based upon the dispensing operating parameters, and setting an initial operating speed of a first pump and an initial operating speed of a second pump based upon the dispensing operating parameters. The method includes dispensing the first material from the first pump operating at the initial operating speed of the first pump, determining an initial operating flow rate of the first material, determining that the initial operating flow rate of the first material is outside of a first predetermined control range, and automatically adjusting the operating speed of the first pump to an adjusted operating speed of the first pump. The method further includes dispensing the second material from the second pump operating at the initial operating speed of the second pump, determining an initial operating flow rate of the second material, determining that the initial operating flow rate of the second material is outside of a second predetermined control range, and automatically adjusting the operating speed of the second pump to an adjusted operating speed of the second pump. The method includes pumping the first material from the first pump at the adjusted operating speed of the first pump, pumping the second material from the second pump at the adjusted operating speed of the second pump, mixing the first material and the second material within a chamber of a mixer to form the mixed material, and dispensing the mixed material from a dispensing nozzle onto the substrate. 
     Various additional features and advantages of this invention will become apparent to those of ordinary skill in the art upon review of the following detailed description of the illustrative embodiments taken in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       The following detailed description is better understood when read in conjunction with the appended drawings. For the purposes of illustration, examples are shown in the drawings; however, the subject matter is not limited to the specific elements and instrumentalities disclosed. In the drawings: 
         FIG. 1  illustrates a dispense system in accordance with aspects of the invention; 
         FIG. 2  illustrates another view of the dispense system of  FIG. 1  in accordance with aspects of the invention; 
         FIG. 3  illustrates yet another view of the dispense system of  FIG. 1  in accordance with aspects of the invention; 
         FIG. 4  illustrates the dispense system in accordance with other aspects of the invention; 
         FIG. 5  illustrates a schematic view of stations of the dispense system in accordance with aspects of the invention; 
         FIGS. 6A-6C  illustrate views of a first and second connector of the dispense system in accordance with aspects of the invention; 
         FIG. 7  illustrates a flow diagram for an exemplary process in accordance with aspects of the invention; and 
         FIG. 8  illustrates a flow diagram for another exemplary process in accordance with aspects of the invention. 
     
    
    
     DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS 
       FIGS. 1-4  schematically illustrate aspects of an exemplary dispense system  100  for dispensing mixed material M, which includes at least a first material M 1  and a second material M 2  onto a substrate  10 . The dispense system  100  may include a first supply  102   a  that may contain the first material M 1  and a second supply  102   b  that may contain the second material M 2 . 
     The dispense system  100  may further include a pump system  110 . The pump system  110  may include a first pump  112   a  and a second pump  112   b . The first pump  112   a  may include an inlet  114   a  in fluid communication with the first supply  102   a  and an outlet  116   a  in fluid communication with the inlet  114   a  of the first pump  112   a . The first pump  112   a  may pump the first material M 1  from the first supply  102   a  through the outlet  116   a  of the first pump  112   a  at a first material flow rate. The second pump  112   b  may include an inlet  114   b  in fluid communication with the second supply  102   b  and an outlet  116   b  in fluid communication with the inlet  114   b  of the second pump  112   b . The second pump  112   b  may pump the second material M 2  from the second supply  102   b  through the outlet  116   b  of the second pump  112   b  at a second material flow rate. 
     The first and second pumps  112   a ,  112   b  may each pump consistent and/or constant amounts of material (i.e., the first material M 1  and the second material M 2 , respectively) from the respective outlets  116   a ,  116   b . The amount of materials pumped from the first and second pumps  112   a ,  112   b  may be equivalent or different from each other depending on, e.g., the size and/or pump speed of each of the respective first and second pumps  112   a ,  112   b . The first and second pumps  112   a ,  112   b  may, for example, be progressive cavity pumps that pump the respective first and second materials M 1 , M 2  at respective first and second pressures/amounts. Accordingly, the respective amounts (e.g., volume) of the first and second materials M 1 , M 2  pumped from the outlets  116   a ,  116   b  of the first and second pumps  112   a ,  112   b  may be constant. The progressive cavity pumps may produce material feed pressures up to 30 barg (approximately 435.11 psig) at the respective outlets  116   a ,  116   b  of the first and second pumps  112   a ,  112   b  while requiring comparatively low pressures at the feed. This eliminates the need for high pressure pneumatic systems in dispensing applications requiring a high pressure feed. A representative progressive cavity pump in accordance with aspects of the invention is described in U.S. application Ser. No. 15/743,659, published as WO 2017/0023895, the disclosure of which is hereby incorporated by reference herein in its entirety. 
     As shown in  FIGS. 1-3 , the first pump  112   a  and the second pump  112   b  may independently pump the respective first and second materials M 1 , M 2  such that a mix ratio between the first material M 1  and the second material M 2  may be varied. For example, the pump system  110  may include a first motor  118   a  that may be operatively connected to and may drive the first pump  112   a . The pump system  110  may include a second motor  118   b  that may be operatively connected to and may drive the second pump  112   b . By changing the pump speed(s) of at least one of the first and second motors  118   a ,  118   b , the mix ratio may be adjusted. As shown in  FIG. 4 , the dispense system  100  may include an alternate pump system  110 ′ embodiment that may employ a single motor  118 .′ The single motor  118 ′ may drive both the first pump  112   a  and the second pump  112   b  such that a mix ratio between the first and second materials M 1 , M 2  is fixed based upon the respective relative sizes of the first and second pumps  112   a ,  112   b . Unless explicitly stated otherwise herein, the dispense system  100  including the alternate pump system  110 ′ of the invention may be used with any components or processes described herein that do not require independent drive of the first and second pumps  112   a ,  112   b . The first motor  118   a , the second motor  118   b , and/or the single motor  118 ′ may include an encoder or other position/rotation/velocity measurement instrument that may measure a rotational speed of the motor to allow for precise motor control. 
     The pump system  110  may also include at least one sensor. For example, the pump system  110  may include a plurality of pressure sensors  117 , such as a resistive transducer, a direct piezo load cell, a resistive diaphragm type, or any other type of sensor that is capable of measuring a fluid pressure and/or converting said fluid pressure into an electrical signal. The pressure sensors  117  may be positioned at the inlets  114   a ,  114   b  and/or the outlets  116   a ,  116   b  of the first and second pumps  112   a ,  112   b.    
     As shown in  FIG. 1 , the dispense system  100  may further include an adapter  120  that may be interchangeably connected to the pump system  110 . The adapter  120  may be used to check and/or control the mix ratio between the first material M 1  and the second material M 2 , e.g., as described in the exemplary processes  700 ,  800  below. The adapter  120  may include a first pathway  122   a  through which the first material M 1  may flow and a second pathway  122   b , that is separate and distinct from the first pathway  122   a , through which the second material M 2  may flow. The first pathway  122   a  may include a first inlet  124   a  the may be in fluid communication with outlet  116   a  of the first pump  112   a . The second pathway  122   b  may include a second inlet  124   b  that may be in fluid communication with the outlet  116   b  of the second pump  112   b . The first pathway  122   a  may further include a first outlet  126   a  in fluid communication with the first inlet  124   a  of the first pathway  122   a  and the second pathway  122   b  may further include a second outlet  126   b  in fluid communication with the second inlet  124   b  of the second pathway  122   b . Accordingly, the adapter  120  may provide distinct pathways (i.e., the first pathway  122   a  and the second pathway  122   b ) through which the first material M 1  and the second material M 2  may respectively flow without mixing together. 
     As shown in  FIGS. 2-6 , the dispense system  100  may also include a mixer  130  that may be interchangeably connected to the pump system  110 . The mixer  130  may be interchangeable with the adapter  120 , i.e., either the mixer  130  or the adapter  120  may be connected to the pump system  110 . The mixer  130  may include a first inlet  134   a  that may be in fluid communication with the outlet  116   a  of the first pump  112   a  and a second inlet  134   b  that may be in fluid communication with the outlet  116   b  of the second pump  112   b . The mixer  130  may also include a chamber  135 , within which the first and second materials M 1 , M 2  may be mixed to form the mixed material M. For example, the chamber  135  may include a first opening  136   a  in fluid communication with the first inlet  134   a  and the second inlet  134   b  of the mixer  130 . Accordingly, the first material M 1  may flow from the first inlet  134   a  of the mixer  130  into the chamber  135  and the second material M 2  may flow from the second inlet  134   b  of the mixer  130  into the chamber  135  and the first and second material M 1 , M 2  may mix therein. The chamber  135  may also include a second opening  136   b  from which the mixed material M may flow out of the chamber  135 . 
     The mixer  130  may include at least one sensor, such as a pressure sensor  137 , a resistive transducer, a direct piezo load cell, a resistive diaphragm type, or any other type of sensor that is capable of measuring a fluid pressure and, preferably, converting said fluid pressure into an electrical signal. The pressure sensor  137  may be positioned at the second opening  136   b  of the chamber  135 . 
     The dispense system  100  may include a first connector  200  and a second connector  300  that may interchangeably connect the pump system  110  to the adapter  120  and/or the mixer  130  to effectuate the interchangeable connection between the pump system  110  and the adapter  120  and/or the mixer  130 . In an embodiment of the invention shown in  FIGS. 1-4 , the first connector  200 , which may be two first connectors  200   a ,  200   b  positioned at opposing sides of the pump system  110 , may be fixed to the pump system  110 . Further, the second connector  300  may be fixed to each of the adapter  120  and the mixer  130 . For example, the adapter  120  may include two second connectors  300   a ,  300   b  fixed thereto, and the mixer  130  may include another two second connectors  300   c ,  300   d  fixed thereto; each of which being positioned at opposing sides of the respective adapter  120  and mixer  130 . In an alternate embodiment of the invention (not shown), the pump system  110  may include the second connector  300  and the adapter  120  and the mixer  130  may each include the first connector  200 . The dispense system  100  may also include a vision and/or sensing system (not shown), that may include cameras or other sensors to enable automatic and/or manual location/detection of the adapter  120  and/or the mixer  130  during interchange. 
     The dispense system  100  may further include a dispensing nozzle  140 . The dispensing nozzle  140  may be in fluid communication with the second opening  136   b  of the chamber  135  of the mixer  130 . The dispensing nozzle  140  may dispense the mixed material M received from the second opening  136   b  of the chamber  135  of the mixer  130 . 
     The dispense system  100  may also include a scale  20 . The scale  20  may determine an amount (e.g., a weight or a mass) of material (e.g., the first material M 1 , the second material M 2 , and/or the mixed material) dispensed thereon. The dispense system  100  may also include a container  30 . The first material M 1  and the second material M 2  may separately be dispensed directly onto the scale  20  via the respective first and second pathways  122   a ,  122   b . As shown in  FIG. 1 , the adapter  120  may be connected to the pump system  110  and the first material M 1  may be dispensed through the first pathway  122   a  onto the scale  20  as the second material M 2  is dispensed from the second pathway  122   b  into the container  30 , and vice versa. Further, the mixer  130  may be interchanged with the adapter  120  and connected to the pump system  110  such that the mixed material M may be dispensed from the dispensing nozzle  140  onto the scale  20 , as shown in  FIGS. 2 and 4 . 
     The dispense system  100  may include a positioner  40 . The positioner  40  may move the dispensing nozzle  140  relative to the scale  20 , the container  30 , and/or the substrate  10  along X, Y, and/or Z axes via, e.g., electromechanical components such as is disclosed in U.S. Pat. No. 5,906,682, the disclosure of which is hereby incorporated by reference herein in its entirety. For example, the positioner  40  may be operatively connected to the pump system  110 , which may be interchangeably connected to either the adapter  120  or the mixer  130  and the dispensing nozzle  140 . By moving the pump system  110 , the positioner  40  may move the adapter  120  and/or the mixer  130  and the dispensing nozzle  140  attached thereto relative to the scale  20 , the container  30 , and/or the substrate  10 . Alternatively, in embodiments not shown, the pump system  110  may be stationary and the positioner  40  may be connected to the adapter  120  and/or the mixer  130  and the dispensing nozzle  140  to effectuate movement relative to the pump system  110 . 
     The dispense system  100  may also include a controller  50  that may automatically control operation of, e.g., the pump system  110 , the first connector  200 , the second connector  300 , the scale  20 , and/or the positioner  40 . The controller  50  may be a programmable logic controller (PLC), a microprocessor based controller, personal computer, or another conventional control device capable of carrying out the functions described herein as understood by a person having ordinary skill in the art. For example, the controller  50  may automatically execute aspects of the dispense routine of the processes  700 ,  800 , as described below. The dispense system  100  may also include a human machine interface (HMI) device  60  that may be operatively connected to the controller  50  in a known manner. The HMI device  60  may include input devices and controls, such as a keypad, pushbuttons, control knobs, a touch screen, etc., and output devices, such as displays and other visual indicators, that are used by an operator to control the operation of the controller  50  and, thereby, control the operation of the dispense system  100 . The HMI device  60  may further include an audio output device, such as a speaker, by which an audio alert may be communicated to an operator. 
     The controller  50  may control operation of the first pump  112   a  to dispense the first material M 1  at the first material flow rate onto the scale  20 . The controller  50  may control operation of the first pump  112   a  by manipulating electrical current supplied to the first motor  118   a  to vary the operating speed thereof. Measurements of the position/velocity of the first motor  118   a  may be taken by the encoder of the first motor  118   a  and may be used by the controller  50  for precise control of operation of the first pump  112   a . The controller  50  may control operation of the second pump  112   b  to dispense the second material M 2  at the second material flow rate. The controller  50  may control operation of the second pump  112   b  by manipulating electrical current supplied to the second motor  118   b  to vary the operating speed thereof. Measurements of the position/velocity of the second motor  118   b  may be taken by the encoder of the second motor  118   b  and may be used by the controller  50  for precise control of operation of the second pump  112   b . In embodiments of the invention, by independently selectively varying current supplied to the first and second motors  118   a ,  118   b , the controller  50  may variably control the mix ratio of the first and second materials M 1 , M 2 . For the alternate pump system embodiment  110 ,′ the controller  50  may control operation of the single motor  118 ′ connected to both the first and second pumps  112   a ,  112   b  to control operation of the first and second pumps  112   a ,  112   b  by varying electric current supplied to the single motor  118 .′ Accordingly, the mix ratio between the first material M 1  and the second material M 2  may be fixed based upon the respective sizes of the first and second pumps  112   a ,  112   b.    
     The controller  50  may control operation of the pump system  110  such that the first material M 1  is pumped from the first supply  102   a  through the first inlet  134   a  of the mixer  130  and to the first opening  136   a  of the chamber  135  at the first material flow rate. The controller  50  may control operation of the pump system  110  such that the second material M 2  is pumped from the second supply  102   b  through the second inlet  134   b  of the mixer  130  and to the first opening  136   a  of the chamber  135 . Accordingly, the first material M 1  and the second material M 2  may converge at the first opening  136   a  of the chamber  135  and mix within the chamber  135  to provide the mixed material M and the mixed material M may flow through the second opening  136   b  of the chamber  135  and may be dispensed from the dispensing nozzle  140  onto the scale  20 . 
     The scale  20  may determine the amount of the first material M 1  dispensed thereon and communicate a first output corresponding to the amount of the first material M 1  to the controller  50 . The scale  20  may determine the amount of the second material M 2  dispensed thereon and communicate a second output corresponding to the amount of the second material M 2  to the controller  50 . The scale  20  may also determine the amount of the mixed material M dispensed thereon and communicate a mixed material output corresponding to the amount of the mixed material M to the controller  50 . The controller  50  may control operation of the pump system  110  (e.g., pump speeds of the first and second pumps  112   a ,  112   b ), based upon the outputs received from the controller  50  (e.g., the first output, the second output, and/or the mixed output) to respectively adjust the first material flow rate to an adjusted first material flow rate and the second material flow rate to an adjusted second material flow rate. 
     The controller  50  may also control operation of the first pump  112   a  and the second pump  112   b  to respectively pump the first material M 1  at the adjusted first material flow rate and the second material M 2  at the adjusted second material flow rate to dispense the mixed material M from the dispensing nozzle  140  onto the substrate  10 . The dispensing processes  700 ,  800 , described below, provide additional details regarding automatic control of the dispense system  100  in accordance with aspects of the controller  50  of the present invention. 
     As shown schematically in  FIG. 5 , the dispense system  100  may include a plurality of stations such as an interchange station  70 , a ratio station  80 , and/or a dispense station  90 . The interchange station  70  may hold and/or store at least one of the adapter  120  and the mixer  130  while not connected to the pump system  110 . Alternatively, the adapter  120  may be held and/or stored at the ratio station  80  and/or the mixer  130  may be held and/or stored at the dispense station  90 . Still further, a plurality of interchange stations  70  may be provided. One of the plurality of interchange stations  70  may be dedicated to holding/storing the adapter  120  and another of the plurality of interchange stations  70  may be dedicated to holding/storing the mixer  130 . In embodiments not shown, the interchange station  70  may hold a plurality of the adapters  120  and/or mixers  130  that may each be selectively automatically connected to the pump system  110 . 
     According to aspects of the invention, the positioner  40  may move the pump system  110  to the interchange station  70  and the pump system  110  may be automatically connected to the adapter  120 . The positioner  40  may move the pump system  110 , with the adapter  120  connected thereto, to the ratio station  80 , which may include the scale  20  and/or the container  30 . At the ratio station  80 , a mix ratio of the first and/or the second materials M 1 , M 2  may be confirmed and/or controlled, as described in the exemplary processes  700 ,  800  below. The positioner  40  may move the pump system  110  to the interchange station  70  where the adapter  120  and the mixer  130  may be automatically interchanged. The positioner  40  may move the pump system  110 , with the mixer  130  connected thereto, to the dispense station  90 , which may include the substrate  10 . At the dispense station  90 , the mixed material M may be dispensed from the mixer  130  onto the substrate  10 . 
       FIGS. 6A-6C  depict an exemplary embodiment the first connector  200  and the second connector  300  of the dispense system  100  in accordance with aspects of the invention.  FIG. 6A  shows the first connector  200  disconnected from the second connector  300 .  FIG. 6B  shows the first connector  200  engaged with the second connector  300 .  FIG. 6C  shows the first connector  200  latched to the second connector  300 . In the exemplary embodiment, the first connector  200  is fixed to the pump system  110  and the second connector  300  is fixed to the mixer  130 . As discussed above and shown schematically in  FIG. 1 , the second connector  300  may also similarly be fixed to the adapter  120 . 
     The second connector  300  may include a tab  310  having ahead  312  and a narrowed portion  314  disposed between the head  312  and the mixer  130 . The second connector  300  may be integrally molded to the mixer  130 . Alternatively, the second connector  300  may be fixed to the mixer  130  via a retainer (not shown). Though not shown, the second connector  300  may similarly be integrally molded, or alternatively fixed via a retainer (not shown), to the adapter  120 . 
     The first connector  200  may include abase  210  that may be fixed to the pump system  110 . The base  210  may include two pins  212  that project therefrom. The first connector  200  may also include a linkage  220 . The linkage  220  may include a first link  222  having a first end and a second end. The linkage  220  may further include a second link  224  having a first end, a second end, and a central portion. The linkage  220  may also include a third link  226  that is slidably connected to the base  210 . The third link  226  may be downwardly biased in a vertical direction. For example, the third link  226  may be connected to a spring (not shown) that may supply the downward bias and that may maintain a force on the second connector  300 . The third link  226  may include a central portion that the second end of the second link  224  is rotatably connected to. The linkage  220  may also include a fourth link  228  having a first end and a second end. The second end of the fourth link  228  may be rotatably connected to the second end of the first link  222 . 
     The first connector  200  may also include a claw  230 . The claw  230  may have a first finger  232  and a second finger  234  that may surround the head  312  of the second connector  300  to effectuate the interchangeable connection between the first connector  200  and the respective second connector  300 . Each of the first finger  232  and the second finger  234  may respectively have a first end that is rotatably connected to the central portion of the second link  224 , a second end. The second end of the first and second fingers  232 ,  234  may each include a hook that may connect to the narrowed portion  314  of the respective second connector  300 , and a channel  235 ,  237  configured to respectively receive one of the two pins  212  of the base  210 . The channels  235 ,  237  may respectively reinforce and guide movement of the fingers  232 ,  234 . The downward bias of the third link  226  may be transferred through the second link  224  to bias the claw  230  in an open position, as shown in  FIG. 6A . Further, the downward bias of the third link  226  transferred through the second link  224  to the claw  230  may cause the claw  230  to make a “click” sound as the fingers  232 ,  234  snap in place in the narrowed portion  314  of the second connector  300 , as shown in  FIG. 6B . By producing a “click” sound when the fingers  232 ,  234  snap in place in the narrowed portion  314  of the second connector  300 , a user may receive audible feedback indicating that the first connector  200  and the second connector  300  are in position for connection. 
     The first connector  200  may also include an actuator  240 , such as a solenoid or a pneumatic actuator. The actuator  240  may be fixed to the pump system  110  and may be rotatably coupled to the first end of the fourth link  228 . The actuator  240  may drive the linkage  220  to initiate opening and closing of the claw  230 . For example, the actuator  240  may rotate the fourth link  228  counter-clockwise to move the linkage  220  into an over-center cam position to lock the first connector  200  to the second connector  300 , as shown in  FIG. 6C . Similarly, the actuator  240  may rotate the fourth link  228  clockwise to unlock the first connector  200  and the second connector  300 . The actuator  240  may be operatively connected to and subject to control by a controller  50 . 
       FIG. 7  illustrates a flow diagram of an exemplary process  700  for dispensing the mixed material M, which includes at least the first material M 1  and the second material M 2 , onto the substrate  10 . The process  700  may be implemented with any suitable embodiments the dispensing system  100 , described above. In addition, the process  700  may be automatically executed by the controller  50 . Generally, the process  700  may include a flow control routine (steps  702 - 712 ) including receiving dispensing operating parameters, dispensing the first and second materials M 1 , M 2  at respective first and second flow rates and determining the amounts of the first and second materials M 1 , M 2  dispensed. The flow control routine of the process  700  may also include automatically adjusting the pump system  110  to adjusted first and second flow rates for the respective first and second materials M 1 , M 2 , and mixing and dispensing the first and second materials M 1 , M 2  onto the substrate  10 . 
     In particular, the process  700  may include, at step  702 , receiving dispensing operating parameters for the dispense system  100 . For example, a user may enter the operating parameters into the controller  50  via the HMI device  60 . The dispensing operating parameters may include, e.g., a first pump constant C 1  for the first pump  112   a  (e.g., a fixed volume of material pumped per rotation of the first pump  112   a ), a second pump constant C 2  for the second pump  112   b  (e.g., a fixed volume of material pumped per rotation of the second pump  112   b ), a target mix ratio R T  of the first material M 1  and the second material M 2  (e.g., by mass or by volume), a density of the first material ρ 1 , and/or a density of the second material ρ 2 . 
     Step  702  may also include determining an operating speed ω 1  for the first pump  112   a  and an operating speed ω 2  for the second pump  112   b  based upon the received dispensing operating parameters. For example, using the received operating parameters for the target mix ratio R T , the first pump constant C 1  for the first pump  112   a , and the second pump constant C 2  for the second pump  112   b , the operating speed ω 1  for the first pump  112   a  and the operating speed ω 2  for the second pump  112   b  may be selected from any operating speeds that satisfy equation 1 as follows: 
     
       
         
           
             
               
                 
                   
                     R 
                     T 
                   
                   = 
                   
                     
                       ( 
                       
                         
                           C 
                           1 
                         
                         * 
                         
                           ω 
                           1 
                         
                       
                       ) 
                     
                     
                       ( 
                       
                         
                           C 
                           2 
                         
                         * 
                         
                           ω 
                           2 
                         
                       
                       ) 
                     
                   
                 
               
               
                 
                   [ 
                   1 
                   ] 
                 
               
             
           
         
       
     
     As would be appreciate by a person having ordinary skill in the art, because the first and second pump constants C 1 , C 2  may be fixed volumes of material pumped per rotation of the respective first and second pumps  112   a ,  112   b , the target mix ratio R T  used in equation 1 will be a volumetric ratio. If the received target mix ratio R T  is a mass ratio, the process  700  may further include converting the target mix ratio R T  to a volumetric ratio using a ratio of the densities of the first and second materials ρ 1 , ρ 2 . For example, if the target mix ratio R T  is provided as a ratio of the mass Ma 1  of the first material M 1  to the mass Ma 2  of the second material M 2  (i.e. Ma 1 /Ma 2 ), the target mix ratio R T  may be converted to a volumetric ratio (R T-Volumetric ) by multiplying the mass ratio by the inverse of the density ratio of the first and second materials, as provided in equation 2: 
     
       
         
           
             
               
                 
                   
                     R 
                     
                       T 
                        
                       _ 
                        
                       Volumetric 
                     
                   
                   = 
                   
                     
                       
                         ρ 
                         2 
                       
                       
                         ρ 
                         1 
                       
                     
                     * 
                     
                       
                         Ma 
                         1 
                       
                       
                         Ma 
                         2 
                       
                     
                   
                 
               
               
                 
                   [ 
                   2 
                   ] 
                 
               
             
           
         
       
     
     In embodiments, the received target mix ratio R T  may be a volumetric ratio and the process  700  may further include converting the target mix ratio R T  to a mass ratio (e.g., for various dispensing calibration routines) using a ratio of the densities of the first and second materials ρ 1 , ρ 2 . For example, if the target mix ratio R T  is provided as a ratio of the volume V 1  of the first material M 1  to the volume V 2  of the second material M 2  (i.e., V 1 /V 2 ), the target mix ratio R T  may be converted to a mass ratio (R T-Mass ) by multiplying the volumetric ratio by the density ratio of the first and second materials, as provided in equation 3: 
     
       
         
           
             
               
                 
                   
                     R 
                     
                       T 
                        
                       _ 
                        
                       Mass 
                     
                   
                   = 
                   
                     
                       
                         ρ 
                         1 
                       
                       
                         p 
                         2 
                       
                     
                     * 
                     
                       
                         V 
                         1 
                       
                       
                         V 
                         2 
                       
                     
                   
                 
               
               
                 
                   [ 
                   3 
                   ] 
                 
               
             
           
         
       
     
     As discussed above, the densities of the first and second materials ρ 1 , ρ 2  may be operating parameters received by the dispense system  100 . Alternatively, the process  700  may include determining the respective densities of the first and second materials ρ 1 , ρ 2 . For example, the densities of the first and second materials ρ 1 , ρ 2  may be calculated by measuring a mass of a known volume of material (i.e., the first material M 1  and/or the second material M 2 ) that may be dispensed from the dispense system  100 , as would be readily understood by a person having ordinary skill in the art. 
     The process  700  may include, at step  704 , dispensing the first material M 1  from the first pump  112   a  at a first material flow rate onto the scale  20  and determining an amount (e.g., a volume, a mass, a weight, etc.) of the first material M 1  dispensed onto the scale  20 . The first material flow rate may result from operating the first pump  112   a  at the operating speed ω 1  (as determined at step  702 ). For example, the controller  50  may automatically control an amount of power supplied to the first motor  118   a  until the encoder of the first motor  118   a  indicates that the operating speed ω 1  has been achieved. The dispensing of the first material M 1  onto the scale  20  may be performed over a first measurement period. 
     The process  700  may include, at step  706 , dispensing the second material M 2  from the second pump  112   b  at the second material flow rate onto the scale  20  and determining an amount (e.g., a volume, a mass, a weight, etc.) of the second material M 2  dispensed onto the scale  20 . The second material flow rate may result from operating the second pump  112   b  at the operating speed ω 2  (as determined at step  702 ). For example, the controller  50  may automatically control an amount of power supplied to the second motor  118   b  until the encoder of the second motor  118   b  indicates that the operating speed ω 2  has been achieved. The dispensing of the second material M 2  onto the scale  20  may be performed over a second measurement period. The duration of the first measurement period, during which the first material M 1  is dispensed onto the scale  20  at step  704 , and the duration of the second measurement period may be equivalent. 
     The process  700  may further include, at step  708 , determining an operating mix ratio R OP  of the first material M 1  and the second material M 2  based upon the amount of the first material M 1  dispensed onto the scale  20  over the first measurement period and the amount of the second material M 2  dispensed onto the scale  20  over the second measurement period (as determined at steps  704  and  706 ). The operating mix ratio R OP  may be compared to the target mix ratio R T  (as received at step  702 ). If the operating mix ratio R OP  is within a predetermined ratio control range, the process  700  may proceed directly to step  712 , described below. However, if the operating mix ratio R OP  is outside of the predetermined ratio control range, the process  700  may proceed to step  710 , at which the first and second material flow rates are adjusted. The predetermined ratio control range may, for example, be within 5% of the target mix ratio R T . The predetermined ratio control range may also be within 1% of the target mix ratio R T . 
     The process  700  may include, at step  710 , adjusting the dispensing of the first material M 1  to an adjusted first material flow rate and the dispensing of the second material M 2  to an adjusted second material flow rate based upon the amounts of the first and second materials M 1 , M 2  dispensed onto the scale  20  (as determined at steps  704  and  706 ) and based upon the dispensing operating parameters for the dispense system  100  (as received at step  702 ). The dispensing of the first and second materials M 1 , M 2  may include proportionally adjusting the first material flow rate and the second material flow rate. For example, the dispensing of the first and second materials M 1 , M 2  may be adjusted from the first and second material flow rates in proportion to the amount that the operating mix ratio R OP  is outside of the predetermined ratio control range. The dispensing of the first and second materials M 1 , M 2  may be adjusted by adjusting the operating speeds ω 1 , ω 2  of the first and second pumps  112   a ,  112   b . For example, the controller  50  may automatically control an amount of power supplied to the first and second motors  118   a ,  118   b  until the encoders of the first and second motor  118   a ,  118   b  indicate that desired adjusted operating speeds of the first and second motors  118   a ,  118   b  have been achieved. From step  710 , the process  700  may proceed directly to step  712 , described below. Alternatively, aspects of the process  700  may be iterative. For example, upon completion of step  710  and prior to proceeding to step  712 , the process  700  may repeat steps  704 - 708  at the adjusted first and second material flow rates to confirm that the adjustments brought the operating mix ratio R OP  within the predetermined ratio control range. 
     Upon completion of the flow control routine the process  700  may include, at step  712 , pumping the first material M 1  from the first pump  112   a  and pumping the second material M 2  from the second pump  112   b . If the operating mix ratio R OP  is determined to be within the predetermined ratio control range at step  708 , the first material M 1  and the second material M 2  may be pumped at the first and second material flow rates, respectively. If the operating mix ratio R OP  is determined to be outside of the predetermined ratio control range, the first material M 1  and the second material M 2  may be respectively pumped at the adjusted first and second material flow rates (as determined at step  710 ). Step  712  may further include mixing the first material M 1  and the second material M 2  within the chamber  135  of the mixer  130  to form the mixed material M and dispensing the mixed material M from the dispensing nozzle  140  onto the substrate  10 . 
     In addition, step  712  may include a verification of the flow rate of the mixed material M from the dispensing nozzle  140 . The verification may be performed, for example, prior to dispensing on the substrate  10 , after a fixed amount of substrates have been processed, after a fixed period of time, etc. For example, a target mixed material flow rate may be determined by adding the flow rates of the first and second materials M 1 , M 2  utilized for the dispensing of the mixed material M. The process  700  may dispense the mixed material M over a period of time by operating the first and second pumps  112   a ,  112   b , measuring the mass of the mixed material M dispensed for the period of time, and determining an operating mixed material flow rate from the measured mass of the mixed material and the period of time. The target mixed material flow rate may be compared to the determined operating mixed material flow rate. If the determined operating mixed material flow rate exceeds a predetermined flow rate control range, the dispense system  100  may shut down and indicate to a user that there is a system error via the HMI device  60 . The predetermined flow rate control range may, for example, be within 5% of the target mixed material flow rate. The predetermined ratio control range may be within 1% of the target mixed material flow rate. 
     Conversely, if the determined operating mixed material flow rate is within the predetermined flow rate control range, the dispense system  100  may calibrate a dispense protocol based upon the determined operating mixed material flow rate. For example, a user may specify and input into the dispense system  100  (via the HMI  60 ) an amount of the mixed material M (e.g., a volume or mass) to be dispensed onto the substrate  10 . The user may also input into the dispense system  100  (via the HMI  60 ) a predetermined location(s) and/or a line length on the substrate  10  at which the mixed material M is to be dispensed. The dispense system  100  may automatically convert the units (e.g., mass to volume and/or volume to mass) of the amount of the mixed material M to be dispensed onto the substrate  10  and/or of the determined operating mixed material flow rate using the densities of the first and second materials ρ 1 , ρ 2 . Units may be automatically converted to ensure that like-units are utilized during calibration of the dispense protocol. 
     The dispense system  100  may automatically calibrate a dispense protocol based upon the specified amount of the mixed material M to be dispensed onto the substrate  10  and the determined operating mixed material flow rate. For example, the dispense system  100  may automatically calibrate a dispense protocol for dispensing a line of the mixed material M onto the substrate. The automatic calibration may include determining a velocity of the dispense nozzle  140  while the dispense nozzle  140  dispenses the mixed material M at the determined operating mixed material flow rate. Determining the velocity of the dispense nozzle  140  may include multiplying the determined operating mixed material flow rate by a length of the line on the substrate along which the mixed material M is to be dispensed and by a reciprocal of the amount of the mixed material M to be dispensed along the line on the substrate  10 . In another example, the dispense system  100  may automatically calibrate a dispense protocol for at least one predetermined location of the substrate  10  (i.e., without moving the dispense nozzle  140  during the dispensing at the predetermined location). The automatic calibration may include determining a time for dispensing the mixed material M at the predetermined location. Determining the time for dispensing the mixed material M at the predetermined location may include dividing the amount of the mixed material M to be dispensed at the predetermined location by the determined operating mixed material flow rate. 
     Further, step  712  may include monitoring the dispense system  100  during the dispensing of the mixed material M from the dispensing nozzle  140  onto the substrate  10 . For example, a system pressure (e.g., a pressure measured at any of the pressure sensors  117 ,  137 ) may be monitored and the dispense system  100  may shut down and indicate to a user that there is a system error via the HMI device  60  if the system pressure deviates a predetermined amount from a predetermined system pressure threshold. Similarly, current supplied to any of the motors  118   a ,  118   b ,  118 ′ of embodiments of the pump systems  110 ,  110 ′ may be monitored and the dispense system  100  may shut down and indicate to a user that there is a system error via the HMI device  60  if the current deviates a specified amount from a predetermined current threshold. 
     According to aspects of the invention, the ratio/amounts of the first and second materials M 1 , M 2  mixed and dispensed onto the substrate  10  may be precisely controlled thereby improving the dispensing of the mixed material M on the substrate  10 . 
       FIG. 8  illustrates a flow diagram of another exemplary process  800  for dispensing the mixed material M, which includes at least the first material M 1  and the second material M 2 , onto the substrate  10 . The process  800  may be implemented with any suitable embodiments the dispensing system  100 , described above. In addition, the process  800  may be automatically executed by the controller  50 . Generally, the process  800  may include a flow control routine (steps  802 - 818 ) including receiving dispensing operating parameters, dispensing the first and second materials M 1 , M 2 , and determining operating flow rates for the first and second materials M 1 , M 2 . The flow control routine of the process  800  may also include automatically adjusting the pump system  110  to adjusted first and second flow rates for the respective first and second materials M 1 , M 2 , and mixing and dispensing the first and second materials M 1 , M 2  onto the substrate  10 . 
     In particular, the process  800  may include, at step  802 , receiving dispensing operating parameters for the dispense system  100 . For example, a user may enter the operating parameters into the controller  50  via the HMI device  60 . The dispensing operating parameters may include, e.g., the first pump constant C 1  for the first pump  112   a , the second pump constant C 2  for the second pump  112   b , the target mix ratio R T  of the first material M 1  and the second material M 2 , the density of the first material ρ 1 , and/or the density of the second material ρ 2 , as discussed in detail in the description of the process  700  above. 
     Step  802  may also include determining the operating speed ω 1  for the first pump  112   a  and the operating speed ω 2  for the second pump  112   b  based upon the received dispensing operating parameters. As explained above in the description of the process  700  above, using the received operating parameters for the target mix ratio R T , the first pump constant C 1  for the first pump  112   a , and the second pump constant C 2  for the second pump  112   b , the operating speed ω 1  for the first pump  112   a  and the operating speed ω 2  for the second pump  112   b  may be selected from any operating speeds that satisfy equation 1: 
     
       
         
           
             
               
                 
                   
                     R 
                     T 
                   
                   = 
                   
                     
                       ( 
                       
                         
                           C 
                           1 
                         
                         * 
                         
                           ω 
                           1 
                         
                       
                       ) 
                     
                     
                       ( 
                       
                         
                           C 
                           2 
                         
                         * 
                         
                           ω 
                           2 
                         
                       
                       ) 
                     
                   
                 
               
               
                 
                   [ 
                   1 
                   ] 
                 
               
             
           
         
       
     
     As would be appreciated by a person having ordinary skill in the art, because the first and second pump constants C 1 , C 2  may be fixed volumes of material pumped per rotation of the respective first and second pumps  112   a ,  112   b , the target mix ratio R T  used in equation 1 will be a volumetric ratio. If the received target mix ratio R T  is a mass ratio, the process  800  may further include converting the target mix ratio R T  to a volumetric ratio using a ratio of the densities of the first and second materials ρ 1 , ρ 2 , as explained in detail in the description of the process  700  above. In embodiments, the received target mix ratio R T  may be a volumetric ratio and the process  800  may further include converting the target mix ratio R T  to a mass ratio (e.g., for various dispensing calibration routines) using a ratio of the densities of the first and second materials ρ 1 , ρ 2 , as is also explained in detail in the description of the process  700  above. 
     The process  800  may also include, at step  804 , calculating a target flow rate for the first material M 1  and a target flow rate for the second material M 2 . The target flow rates may, for example, be calculated based upon the dispensing operating parameters (i.e., the first pump constant C 1  for the first pump  112   a , the second pump constant C 2  for the second pump  112   b , and the operating speed ω 1  for the first pump  112   a  and the operating speed ω 2  for the second pump  112   b , determined at step  802 ). The target flow rate for the first material M 1  may be calculated by multiplying the first pump constant C 1  for the first pump  112   a  by the operating speed ω 1  for the first pump  112   a  determined at step  802  (i.e., C 1 *ω 1 ). The target flow rate for the second material M 2  may be calculated by multiplying the second pump constant C 2  for the second pump  112   b  by the operating speed ω 2  for the second pump  112   b  determined at step  802  (i.e., C 2 *ω 2 ). Step  804  may further include calculating a target flow rate for the mixed material M. The target flow rate for the mixed material M may be calculated by adding the target flow rate for the first material M 1  and the target flow rate for the second material M 2 . 
     The process  800  may further include, at step  806 , setting initial operating speeds for the first pump  112   a  and the second pump  112   b . The initial operating speeds for the first pump  112   a  and the second pump  112   b  may be based upon the dispense operating parameters received at step  802 . For example, the operating speed of the first pump  112   a  may be set to the operating speed ω 1  for the first pump  112   a  determined at step  802  and the operating speed for the second pump  112   b  may be set to the operating speed ω 2  for the second pump  112   b  determined at step  802 . As discussed at step  804 , the operating speed ω 1  for the first pump  112   a  determined at step  802  is expected to produce the target flow rate for the first material M 1  and the operating speed ω 2  for the second pump  112   b  determined at step  802  is expected to produce the target flow rate for the second material M 2 . 
     The process  800  may include steps for ensuring that an operating flow rate of the first material M 1  is within a predetermined control range (steps  808   a - 812   a ) and steps for ensuring that an operating flow rate of the second material M 2  is within a predetermined control range (steps  808   b - 812   b ). Ensuring that the operating flow rate of the first material M 1  is within the predetermined control range (steps  808   a - 812   a ) may occur before, after, or concurrently with ensuring that the operating flow rate of the second material M 2  is within the predetermined control range (steps  808   b - 812   b ). For example, according to aspects of the process  800  disclosed in detail below, steps  808   a - 812   a  are executed prior to steps  808   b - 812   b . Nevertheless, in accordance with other embodiments of the invention, steps  808   b - 812   b  may be executed prior to steps  808   a - 812   a . Further, in accordance with embodiments of the invention, steps  808   a - 812   a  may be executed concurrently with steps  808   b - 812   b , provided that the pump system  110  is equipped with the adapter  120  and more than one scale is provided for calculating operating flow rates. 
     Ensuring that the operating flow rate of the first material M 1  is within the predetermined control range may begin, at step  808   a , by determining the operating flow rate of the first material M 1  (i.e., an initial operating flow rate of the first material or an adjusted operating flow rate of the first material). Determining the operating flow rate of the first material M 1  may include dispensing the first material M 1  onto the scale  20  and measuring an amount (e.g., a volume, a mass, a weight, etc.) of the first material M 1  dispensed onto the scale  20 . The first material M 1  is dispensed by operating the first pump  112   a  at an operating speed set at either step  806  (i.e., the operating speed ω 1 , which is also referred to as an initial operating speed of the first pump  112   a ) or step  812   a  (i.e., an adjusted operating speed of the first pump  112   a ), described below. For example, the controller  50  may automatically control an amount of power supplied to the first motor  118   a  until the encoder of the first motor  118   a  indicates that the set operating speed has been achieved. The pump system  110  may be equipped with the adapter  120  during execution of each of steps  808   a - 812   a . The pump system  110  may be connected with the adapter  120  at any point prior to execution of step  808   a . Accordingly, the first material M 1  may be pumped by the first pump  112   a , through the first pathway  122   a , and onto the scale  20 . The dispensing of the first material M 1  onto the scale  20  may be performed over a first measurement period. The operating flow rate of the first material M 1  may be determined by dividing the amount of first material M 1  dispensed onto the scale  20  during the first measurement period by the time that elapsed over the first measurement period. 
     The process  800  may proceed from step  808   a  to step  810   a , at which the process  800  determines whether the operating flow rate of the first material M 1  is within the predetermined control range (i.e., a first predetermined control range). If the operating flow rate of the first material M 1  is within the predetermined control range, the process  800  may proceed directly to step  808   b , described below. However, if the operating flow rate of the first material M 1  is outside of the predetermined control range, the process  800  may proceed to step  812   a , at which the set operating speed of the first pump  112   a  is automatically adjusted. The predetermined control range may, for example, be within ±5% of the target flow rate for the first material M 1 , as calculated at step  804 . The predetermined control range may also be within ±1% of the target flow rate for the first material M 1 , as calculated at step  804 . 
     Step  812   a  may include automatically adjusting the set operating speed of the first pump  112   a  to an adjusted operating speed of the first pump  112   a . The set operating speed of the first pump  112   a  may be proportionally adjusted based upon the difference between the operating flow rate of the first material M 1  determined at step  808   a , and the target flow rate for the first material M 1  calculated at step  804 . Steps  808   a - 812   a  may be iteratively performed until the operating flow rate of the first material M 1  is determined to be within the predetermined control range at step  810   a.    
     Ensuring that the operating flow rate of the second material M 2  is within the predetermined control range may begin, at step  808   b , by determining the operating flow rate of the second material M 2  (i.e., an initial operating flow rate of the second material or an adjusted operating flow rate of the second material). Determining the operating flow rate of the second material M 2  may include dispensing the second material M 2  onto the scale  20  and measuring an amount (e.g., a volume, a mass, a weight, etc.) of the second material M 2  dispensed onto the scale  20 . The second material M 2  is dispensed by operating the second pump  112   b  at an operating speed set at either step  806  (i.e., the operating speed ω 2 , which is also referred to as an initial operating speed the second pump  112   b ) or step  812   b  (i.e., an adjusted operating speed of the second pump  112   b ), described below. For example, the controller  50  may automatically control an amount of power supplied to the second motor  118   b  until the encoder of the second motor  118   b  indicates that the set operating speed has been achieved. The adapter  120  may also be connected to the pump system  110  during execution of each of steps  808   b - 812   b . Accordingly, the second material M 2  may be pumped by the second pump  112   b , through the second pathway  122   b , and onto the scale  20 . The dispensing of the second material M 2  onto the scale  20  may be performed over a second measurement period. The operating flow rate of the second material M 2  may be determined by dividing the amount of second material M 2  dispensed onto the scale  20  during the second measurement period by the time that elapsed over the second measurement period. 
     The process  800  may proceed from step  808   b  to step  810   b , at which the process  800  determines whether the operating flow rate of the second material M 2  (i.e., the initial operating flow rate of the second material or the adjusted operating flow rate of the second material M 2 ) is within the predetermined control range (i.e., a second predetermined control range). If the operating flow rate of the second material M 2  is within the predetermined control range, the process  800  may proceed directly to step  814 , described below. However, if the operating flow rate of the second material M 2  is outside of the predetermined control range, the process  800  may proceed to step  812   b , at which the set operating speed of the second pump  112   b  is adjusted. The predetermined control range may, for example, be within ±5% of the target flow rate for the second material M 2 , as calculated at step  804 . The predetermined control range may also be within ±1% of the target flow rate for the second material M 2 , as calculated at step  804 . 
     Step  812   b  may include automatically adjusting the set operating speed of the second pump  112   b  to an adjusted operating speed of the second pump  112   b . The set operating speed of the second pump  112   b  may be proportionally adjusted based upon the difference between the operating flow rate of the second material M 2  determined at step  808   b  and the target flow rate for the second material M 2  calculated at step  804 . Steps  808   b - 812   b  may be iteratively performed until the operating flow rate of the second material M 2  is determined to be within the predetermined control range at step  810   b.    
     Step  814  may include determining the operating flow rate of the mixed material M. Determining the operating flow rate of the mixed material M may include removing the adapter  120  from the pump system  110  and connecting the mixer  130  to the pump system  110 . Once the pump system  110  is connected to the mixer  130 , step  814  may include dispensing the mixed material M onto the scale  20  and measuring an amount (e.g., a volume, a mass, a weight, etc.) of the mixed material M dispensed onto the scale  20 . The mixed material M is dispensed by operating the first pump  112   a  at an operating speed set at either step  806  (i.e., the initial operating speed of the first pump  112   a ) or step  812   a  (i.e., the adjusted operating speed of the first pump  112   a ), and by operating the second pump  112   b  at an operating speed set at either step  806  (i.e., the initial operating speed of the second pump  112   b ) or step  812   b  (i.e., the adjusted operating speed of the second pump  112   b ). The first material M 1  and the second material M 2  may be respectively pumped by the first pump  112   a  and the second pump  112   b  at the set operating speeds, and mixed within the chamber  135  of the mixer  130  to form the mixed material M. From the chamber  135 , the mixed material M may be dispensed through the dispensing nozzle  140  onto the scale  20 . The dispensing of mixed material M onto the scale  20  may be performed over a third measurement period. The operating flow rate of the mixed material M may be determined by dividing the amount of mixed material M dispensed onto the scale  20  during the third measurement period by the time that elapsed over the third measurement period. 
     The process  800  may proceed from step  814  to step  816 , at which the process  800  determines whether the operating flow rate of the mixed material M is within a predetermined control range (i.e., a third predetermined control range). If the operating flow rate of the mixed material M is within the predetermined control range, the process  800  may proceed directly to step  818 , described below. However, if the operating flow rate of the mixed material M (i.e., an initial operating flow rate of the mixed material M) is outside of the predetermined control range, the process  800  may repeat steps  808   a - 816  (i.e., automatically readjust the operating speed of the first pump  112   a  and/or the operating speed of the second pump  112   b ) to troubleshoot the problem. Alternatively, if the determined operating flow rate of the mixed material M exceeds the predetermined control range, the dispense system  100  may shut down and indicate to a user that there is a system error via the HMI device  60 . The predetermined control range may, for example, be within ±5% of the target flow rate for the mixed material M, which may be as calculated at step  804  as the summation of the target flow rate for the first material M 1  and the target flow rate for the second material M 2 . The predetermined control range may also be within 1% of the target flow rate for the mixed material M. 
     Upon completion of the flow control routine the process  800  may include, at step  818 , dispensing the mixed material M onto the substrate  10 . The mixed material M is dispensed by operating the first pump  112   a  at an operating speed set at either step  806  (i.e., the initial operating speed of the first pump  112   a ) or step  812   a  (i.e., the adjusted operating speed of the first pump  112   a ), and by operating the second pump  112   b  at an operating speed set at either step  806  (i.e., the initial operating speed of the second pump  112   b ) or step  812   b  (i.e., the adjusted operating speed of the second pump  112   b ). The first material M 1  and the second material M 2  may be respectively pumped by the first pump  112   a  and the second pump  112   b  at the set operating speeds, and mixed within the chamber  135  of the mixer  130  to form the mixed material M. From the chamber  135 , the mixed material M may be dispensed through the dispensing nozzle  140  onto the substrate  10 . 
     Dispensing the mixed material M onto the substrate  10  at step  818  may include calibrating a dispense protocol based upon the determined operating flow rate of the mixed material M. For example, a user may specify and input into the dispense system  100  (via the HMI  60 ) an amount of the mixed material M (e.g., a volume or mass) to be dispensed onto the substrate  10 . The user may also input into the dispense system  100  (via the HMI  60 ) a predetermined location(s) and/or a line length on the substrate  10  at which the mixed material M is to be dispensed. The dispense system  100  may automatically convert the units (e.g., mass to volume and/or volume to mass) of the amount of the mixed material M to be dispensed onto the substrate  10  and/or of the operating flow rate of the mixed material M using the densities of the first and second materials ρ 1 , ρ 2 . Units may be automatically converted to ensure that like-units are utilized during calibration of the dispense protocol. 
     Step  818  may also include automatically calibrating a dispense protocol based upon the specified amount of the mixed material M to be dispensed onto the substrate  10  and the determined operating flow rate of the mixed material M. For example, the dispense system  100  may automatically calibrate a dispense protocol for dispensing a line of the mixed material M onto the substrate. The automatic calibration may include determining a velocity of the dispense nozzle  140  while the dispense nozzle  140  dispenses the mixed material M at the determined operating flow rate of the mixed material M. Determining the velocity of the dispense nozzle  140  may include multiplying the determined operating mixed material flow rate by a length of the line on the substrate along which the mixed material M is to be dispensed and by a reciprocal of the amount of the mixed material M to be dispensed along the line on the substrate  10 . In another example, the dispense system  100  may automatically calibrate a dispense protocol for at least one predetermined location of the substrate  10  (i.e., without moving the dispense nozzle  140  during the dispensing at the predetermined location). The automatic calibration may include determining a time for dispensing the mixed material M at the predetermined location. Determining the time for dispensing the mixed material M at the predetermined location may include dividing the amount of the mixed material M to be dispensed at the predetermined location by the determined operating flow rate of the mixed material M. 
     Further, step  818  may include monitoring the dispense system  100  during the dispensing of the mixed material M from the dispensing nozzle  140  onto the substrate  10 . For example, a system pressure (e.g., a pressure measured at any of the pressure sensors  117 ,  137 ) may be monitored and the dispense system  100  may shut down and indicate to a user that there is a system error via the HMI device  60  if the system pressure deviates a predetermined amount from a predetermined system pressure threshold. Similarly, current supplied to any of the motors  118   a ,  118   b ,  118 ′ of embodiments of the pump systems  110 ,  110 ′ may be monitored and the dispense system  100  may shut down and indicate to a user that there is a system error via the HMI device  60  if the current deviates a specified amount from a predetermined current threshold. 
     According to aspects of the invention, the ratio and/or amounts of the first and second materials M 1 , M 2  mixed and dispensed onto the substrate  10  may be precisely controlled thereby improving the dispensing of the mixed material M on the substrate  10 . 
     While the disclosure has been described in connection with the various embodiments of the various figures, it is to be understood that other similar embodiments can be used or modifications and additions can be made to the described embodiments. Therefore, the methods and systems as described herein should not be limited to any single embodiment, but rather should be construed in breadth and scope in accordance with the appended claims.