Patent Description:
Many industrial applications require the use of discrete, well-defined and uniform coatings applied to predetermined areas. Such coatings are very useful in varied processes, such as conformal coatings on non-uniform or irregular substrates like electronic circuit boards. In the production of discrete coatings for application to discrete substrate areas, for example, it is desirable to obtain broad, uniform coatings in a non-contact application process with sharp, square, cut-on and cut-off edges with no stringing of material. In particular, conformal coating material is used to protect selected components of a circuit board from moisture, dirt, etc..

A satisfactory coating of a substrate with a material includes both the adequate coverage of the material on the surface of the substrate and the application of the material in a desired amount (e.g., thickness). The two goals are often at odds, since an adjustment made to a parameter of a coating material dispensing system to affect one goal may negatively impact the other goal. For instance, if the pressure of the material supplied to the applicator is raised to increase the width of the fan of material dispensed from the applicator, this may cause the thickness of the material being applied to the substrate to fall to an unacceptable level. Therefore, there is a need for improved systems and methods for applying coating materials to a substrate that account for both the coverage of the material and the amount of material applied. <CIT> relates generally to dispensing liquid coating materials, and more particularly to a system and method for applying a liquid coating material to a substrate, such as a circuit board. In more detail, <CIT> describes a system including a controller that can calculate a volume of applied material, compare the volume of applied material to a desired volume, and reduce the difference between the desired volume and dispensed volume in subsequent applications. Other examples of methods and system for dispensing a liquid coating onto a substrate are known from <CIT>, <CIT>, <CIT>, <CIT>.

The present invention relates to a method of applying a material to a substrate. The method includes coating a first substrate with the material using an applicator. A first total amount of the material applied to the first substrate is determined and compared to a first predetermined control range. If it is determined that the first total amount of the material applied to the first substrate is outside of the first predetermined control range, then (<NUM>) a velocity of the applicator, a pulse rate of the applicator, or a temperature of the material is adjusted by a first adjustment amount, and (<NUM>) a fan width of the applicator is adjusted by a second adjustment amount
The adjustments corresponding to the first and second adjustments may change a total amount of material applied to a subsequent, second substrate. The method further includes coating the second substrate with the material using the applicator. A second total amount of the material applied to the second substrate is determined and compared to the first predetermined control range. It is determined that the second total amount of the material applied to the second substrate is within the first predetermined control range.

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:.

With reference to <FIG>, a coating system <NUM> may be used to apply a liquid coating material, such as a conformal coating material, to a series of substrates, such as the representative substrate <NUM>. Although the operation of a representative coating system <NUM> will be described herein, those skilled in the art will appreciate that a wide variety of other coating systems may be used to complete the method described below. The coating system <NUM> may be, for example, a Model SC-<NUM>, SC-<NUM>, or SC-<NUM> conformal coating applicator commercially available from Asymtek (Carlsbad, Calif.

In the representative embodiment, the coating system <NUM> includes a multi-axis electro-mechanical positioner or robot <NUM> and a conformal coating applicator <NUM> coupled with the robot <NUM>. For example, the applicator <NUM> may be suspended from the robot <NUM> above the substrates <NUM>. In one embodiment, the robot <NUM> is adapted to move the applicator <NUM> in directions defined within an X-Y-Z Cartesian coordinate frame to supply three degrees of freedom. The robot <NUM> includes a drive coupled to independently controllable motors (not shown) in a known manner. The applicator <NUM> is manipulated by robot <NUM> relative to the substrate <NUM> for applying amounts of liquid coating material to selected areas of the substrate <NUM>.

A programmable controller <NUM> coordinates the movements and actuations of the coating system <NUM>. The controller <NUM> 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 <NUM> may perform the various flow control routines and fan width control routines described in detail below. A human machine interface (HMI) device <NUM> is operatively connected to the controller <NUM> in a known manner. The HMI device <NUM> 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 <NUM> and, thereby, control the operation of the coating system <NUM>. The HMI device <NUM> may further include an audio output device, such as a speaker, by which an audio alert may be communicated to an operator.

Substrates <NUM>, for example, printed circuit boards with attached semiconductor die and other components, are supported in an operative relationship with the applicator <NUM> in a known manner and liquid coating material is applied from the applicator <NUM> onto selected areas on each substrate <NUM>. Depending on the dispensing application, a series of substrates <NUM> may be coated in a batch mode. Alternatively, the substrates <NUM> may be continuously transported past the applicator <NUM> on an automatic conveyor <NUM>. The conveyor <NUM> has a conventional design and, furthermore, may have a width that can be adjusted to accommodate substrates <NUM> of different dimensions. The conveyor <NUM>, which may also include pneumatically operated lift and lock mechanisms (not shown), receives command signals from a conveyor controller <NUM>.

The applicator <NUM> is electrically coupled with an applicator controller <NUM>, which supplies command signals that control the operation of the applicator <NUM>. A motion controller <NUM> is electrically coupled by a communication link <NUM> with the robot <NUM>. The solenoid <NUM> is electrically coupled by a communication link <NUM> with the motion controller <NUM>. The conveyor controller <NUM> and motion controller <NUM> are also electrically coupled with controller <NUM> over respective communication links <NUM>, <NUM>. The motion controller <NUM> is electrically coupled over a communication link <NUM> with the conveyor controller <NUM>. Thus, a programmable control system for coating system <NUM> includes the controller <NUM>, the applicator controller <NUM>, the motion controller <NUM>, and the optional conveyor controller <NUM> as interconnected components that communicate with each other.

The motion controller <NUM> supplies command signals to the robot <NUM> over the communication link <NUM>. The command signals are used by the robot <NUM> to control the position and/or velocity of the applicator <NUM>. Generally, the robot <NUM> includes electric motors, such as servo motors or stepper motors, that drive the motion of the different axes of the robot <NUM>.

Applicator <NUM> includes a body <NUM> suspended from the robot <NUM>, a nozzle <NUM> mounted to one end of the body <NUM>, and a flow control mechanism (not shown) disposed inside the body <NUM>. The flow control mechanism inside body <NUM> may comprise an air-actuated needle, an air piston, and a valve seat that cooperate to form a dispensing valve (not shown) operative to control a flow of conformal coating material dispensed from the applicator <NUM>. A pressurized fluid supply <NUM> and a solenoid <NUM> cooperate to supply pressurized fluid in a known manner to regulate the actuation of the dispensing valve inside the body <NUM>. Specifically, the solenoid <NUM> controls air pressure in a conduit <NUM> connecting the pressurized fluid supply <NUM> with the applicator <NUM> so as to move the air piston and, thereby, move the needle relative to the valve seat to provide an opened position for the dispensing valve in which liquid coating material is dispensed from the applicator <NUM> onto the substrate <NUM>. The solenoid <NUM> may vent the air pressure acting on the air piston to permit the needle to return to a closed position in which the needle contacts the valve seat to discontinue the dispensing.

The coating system <NUM> may include a fan width sensor <NUM> that may be disposed, for example, on the robot <NUM> or the applicator <NUM>. In some aspects, the fan width sensor <NUM> may also be a separate module independent from the robot <NUM> and the applicator <NUM>. The fan width sensor <NUM> may be configured to determine various characteristics (e.g., width or shape) of the fan of the material dispensed from the applicator <NUM>. As used herein, the fan of the material refers to the shape, and dimensions thereof, of the stream <NUM> of material from the applicator <NUM>. For example, the applicator <NUM> may dispense the material in a conical spray at a known distance between the applicator <NUM> and the substrate <NUM>, whereby the conical spray will produce a circular area of coating on the substrate <NUM> with a certain diameter. As the applicator <NUM> moves along the substrate <NUM>, the conical spray of the material will produce a strip of coating on the substrate <NUM> having a width corresponding with the certain diameter of the conical spray. The fan width sensor <NUM> may be communicatively connected with the motion controller <NUM> and/or controller <NUM>. For instance, the data points indicative of the fan of material and determined by the fan width sensor <NUM> may be communicated to the controller <NUM> and stored in the memory <NUM> therein.

In an aspect, the fan width sensor <NUM> may include a camera and a light or laser source, wherein the stream <NUM> of material may be positioned between the camera and the light or laser source to determine the various characteristics (e.g., width or shape) of the stream <NUM> of material. The camera may be configured to capture images of the fluid pattern of the stream <NUM> as it is dispensed from the applicator <NUM>. The images captured by the camera may be still images or images that comprise a video stream. The camera may forward the images of the fluid pattern to the controller <NUM>, which may use the images to perform other processing steps, such as a fan width control routine. The light or laser source may be configured to emit light or a laser through the fluid pattern of the stream <NUM>. For example, the light or laser source may be located directly in front of the camera on the other side of the applicator <NUM> and on the same horizontal plane as the camera. The light or laser source may provide illumination of the fluid pattern of the stream <NUM> to improve image quality of the images captured by the camera. The fan width sensor <NUM> configured as such may allow the fan width or other characteristics of the stream <NUM> to be determined and, possibly, adjusted in real-time while a substrate is coated. The fan width sensor <NUM> configured with a camera and a light or laser source is fully described in <CIT>, entitled "METHOD AND SYSTEM FOR CONTROLLING A FLUID PATTERN OF A DISPENSED FLUID".

The coating system <NUM> includes a pressurized liquid supply <NUM> that operates in a known manner under the command of controller <NUM> to generate a continuous stream or supply of the pressurized liquid coating material. For example, the pressurized liquid supply <NUM> may include a diaphragm or piston pump that siphons amounts of liquid coating material from a reservoir and then pumps the stream of liquid coating material under pressure from the reservoir through a fluid path to the applicator <NUM>. The pressurized liquid supply <NUM> is electrically connected by a communication link <NUM> with the controller <NUM>, which can regulate operating parameters such as the temperature and pressure of a liquid coating material by communicating appropriate control signals to the pressurized liquid supply <NUM> over communication link <NUM>.

The pressurized liquid supply <NUM> is optionally configured with one or more conventional heating elements 38a that are electrically coupled with a conventional temperature controller <NUM> that is electrically coupled with the controller <NUM>. The construction and operation of conventional heating elements, such as heating elements 38a, and temperature controllers, such as temperature controller <NUM>, are understood by a person having ordinary skill in the art. In an alternative embodiment, the applicator <NUM> may include heating element (not shown) or a heating element (not shown) may be disposed in the one of the conduits <NUM>, <NUM>, <NUM>. Regardless of the specific location of the heating element in the flow path between the pressurized liquid supply <NUM> and the nozzle <NUM>, the liquid coating material may be heated in this flow path before being applied to the substrate <NUM>.

The applicator <NUM> includes a liquid inlet <NUM> that is coupled in fluid communication with a pressurized liquid supply <NUM>. The liquid coating material is supplied from the pressurized liquid supply <NUM> to the applicator <NUM> through the liquid inlet <NUM> for regulated dispensing out of a dispensing orifice (not shown) in the nozzle <NUM>. The body <NUM> has a fluid inlet <NUM> coupled with pressurized fluid supply <NUM> and internal passageways (not shown) that direct the pressurized fluid to outlets in the vicinity of the dispensing orifice in nozzle <NUM>, where the pressurized fluid is discharged to interact with and manipulate the stream <NUM> of liquid coating material that is sprayed from the applicator <NUM>. A fluid regulator <NUM>, which communicates over communication link <NUM> with motion controller <NUM>, controls the flow of pressurized fluid from the pressurized fluid supply <NUM> to the fluid inlet <NUM>. A representative applicator similar to applicator <NUM> is described in <CIT>.

The coating system <NUM> is operated as instructed by a library of operational cycles or sequences that are stored in a memory <NUM> associated with the controller <NUM> and/or stored in other computers. The operational sequences are recalled and placed in a particular operational program, as desired, executing on the controller <NUM>. The operational sequences can be adjusted to accommodate different environmental conditions, different types of substrates <NUM>, or different types of conformal coating material. During operation, the controller <NUM> can transfer an entire operational program as electrical signals over communication link <NUM> to the motion controller <NUM> for execution at the motion controller <NUM>. Alternatively, the controller <NUM> can transfer one or more instructions as electrical signals over communication link <NUM> in a batch of instructions and data to the motion controller <NUM> for subsequent execution. The operator may enter parameters, such as the type of substrate <NUM>, an identifier of substrate <NUM>, a description of substrate <NUM>, the type of liquid coating material, the liquid pressure, the assist air pressure, the velocity of the applicator <NUM>, the distance between the substrate <NUM> and applicator <NUM>, etc., at the HMI device <NUM>. The entered parameters are stored in the memory <NUM> of controller <NUM> for future use in an operational sequence. Each substrate <NUM> is matched by the controller <NUM> with a coating program that determines which specific components and areas of the substrate <NUM> are to be coated with liquid coating material. Typically, the liquid coating material is applied to only selected areas and/or components on the substrate <NUM>.

With continued reference to <FIG>, an "air over fluid" (A/F) regulator <NUM> and a flow meter <NUM> are situated in the flow path for the liquid coating material from the pressurized liquid supply <NUM> to the liquid inlet <NUM> of the applicator <NUM>. As a result, the liquid coating material is constrained to flow through the A/F regulator <NUM> and flow meter <NUM> in transit from the pressurized liquid supply <NUM> to the applicator <NUM>. A liquid input of the A/F regulator <NUM> is coupled by a conduit <NUM> with a liquid outlet of the pressurized liquid supply <NUM>. Similarly, the A/F regulator <NUM> has a liquid outlet coupled by a conduit <NUM> with a liquid input of the flow meter <NUM>, which in turn has a liquid outlet coupled by a conduit <NUM> with the liquid inlet <NUM> of the applicator <NUM>.

The A/F regulator <NUM> controls the fluid pressure of the pressurized liquid material in transit in the fluid path to the applicator <NUM>. The controller <NUM> is electrically coupled by a communication link <NUM> with a regulator <NUM>. In one embodiment, the regulator <NUM> may be a "voltage over pressure" (E/P) regulator that receives a control voltage from the motion controller <NUM> and includes a transducer that converts the control voltage to a fluid pressure. Alternatively, the regulator <NUM> may receive a control current or a serial communications signal, instead of a control voltage, for conversion to a fluid pressure. The regulator <NUM> delivers pressurized fluid to the A/F regulator <NUM> for use in controlling the fluid pressure of the liquid coating material flowing through the A/F regulator <NUM>.

The A/F regulator <NUM> is positioned in a conduit <NUM> defining a fluid path between the pressurized liquid supply <NUM> and the flow meter <NUM>. In an alternative embodiment, the flow meter <NUM> may be positioned in the fluid path between the pressurized liquid supply <NUM> and the A/F regulator <NUM> so that the flow meter <NUM> is upstream from the A/F regulator <NUM>. With this alternative arrangement, the A/F regulator <NUM> would alter the pressure of the liquid coating material after the liquid coating material has flowed through the flow meter <NUM>.

The controller <NUM> is electrically coupled by a communication link <NUM> with the flow meter <NUM>. In response to the flow of liquid coating material from conduit <NUM> to conduit <NUM>, the flow meter <NUM> generates a string of counts or electrical pulses each representing a fixed volume of liquid coating material flowing through or past the flow meter <NUM>. Alternatively, the string of electrical pulses from the flow meter <NUM> may be communicated from the flow meter to the motion controller <NUM> and then relayed from the motion controller <NUM> to the controller <NUM>. In one embodiment, the flow meter <NUM> may comprise a gear meter that rotates in response to flow through the gear meter and, for a fixed amount of rotation representing a known volume, generates an electrical pulse with an encoder that is transmitted as an electrical signal in a signal stream to the controller <NUM>. For example, the gear meter may generate a pulse for every <NUM> cubic centimeters of liquid coating material flowing through the flow meter <NUM>. In another embodiment, the flow meter <NUM> may comprise a thermal mass flow meter.

In use and with reference to <FIG>, the controller <NUM> obtains a coating program for the substrate <NUM> when substrate <NUM> is properly positioned relative to the applicator <NUM>. The coating program determines which components and/or areas of the substrate <NUM> are to be coated with liquid coating material, which is usually applied in strips. For example, possibly twenty-five separate components or areas of a substrate <NUM> may be coated with strips of the liquid coating material. The controller <NUM> retrieves an operational sequence from the memory <NUM> of controller <NUM> and, in turn, communicates control signals to the motion controller <NUM> over communication link <NUM> representing the operational sequence. The motion controller <NUM> sends command signals to the robot <NUM> over communication link <NUM> that instruct the robot <NUM> to move the applicator <NUM> at specified velocities to desired locations with respect to the substrate <NUM>. The motion controller <NUM> controls the movements of the robot <NUM> to move the applicator <NUM> in a plane (e.g., X and Y directions) across the substrate <NUM>, opening and closing the dispensing valve in the applicator <NUM> as necessary during this movement to apply the liquid coating material to the desired components and areas of the substrate <NUM>.

Specifically, at any particular location on substrate <NUM>, the motion controller <NUM> also provides a command signal to the solenoid <NUM> to cause it to change state to open the dispensing valve causing discharge of liquid coating material from nozzle <NUM>. Concurrently, the motion controller <NUM> provides command signals to the robot <NUM> to initiate motion of applicator <NUM> relative to the substrate <NUM>. The stream <NUM> of liquid coating material may be optionally manipulated by an assist fluid, such as air, that affects the shaping of the stream <NUM> discharged from the applicator <NUM>. After a predetermined time lapses, the motion controller <NUM> subsequently changes the state of the valve command signal to return the solenoid <NUM> back to its original state. This action closes the dispensing valve to discontinue the discharge of liquid coating material from the nozzle <NUM> of the applicator <NUM>. The motion controller <NUM> may cause the dispensing valve of the applicator <NUM> to open and close the dispensing valve multiple times (e.g., twenty-five times) during the extent of the coating program so that multiple components and areas of the substrate <NUM> receive an amount of liquid coating material.

During the coating program or in preparation for the execution of the coating program, the controller <NUM> provides electrical signals to the motion controller <NUM>, which prompt the motion controller <NUM> to provide command signals to the regulator <NUM>. The regulator <NUM> controls an air pressure supplied to the A/F regulator <NUM> to selecting a liquid pressure for the pressurized liquid coating material flowing from the pressurized liquid supply <NUM> to the applicator <NUM>. The selected value of liquid pressure, which is dispensing application dependent, may further depend on the desired flow rate of the liquid coating material. The flow rate for the liquid coating material is influenced, among other factors, by the liquid pressure, the diameter of the discharge orifice in the dispensing nozzle <NUM>, the material viscosity, etc..

<FIG> illustrates a flow diagram of an exemplary process <NUM> of coating one or more substrates <NUM> with a material, such as a liquid coating material. The process <NUM> may be executed, at least in part, by the motion controller <NUM> and/or controller <NUM>. Generally, the process <NUM> includes a flow control routine (steps <NUM> - <NUM>) iteratively adjusting the velocity of the applicator <NUM> or other parameter affecting the amount of material applied to the substrate <NUM>. When the sum of the adjustments by the flow control routine exceed a predetermined threshold (step <NUM>), which may be indicative of the fan width of the dispensed material having changed, a fan width control routine (step <NUM>) will thereby adjust the fan width to conform to a specified standard.

At step <NUM>, a substrate <NUM>, or portion thereof, may be coated with the material. As the substrate <NUM> is coated with the material, the amount of material may be measured. For example, as the material flows from the pressurized liquid supply <NUM> and out the applicator <NUM>, the flow meter <NUM> may transmit to the controller <NUM> a count or electrical pulse for each fixed amount of material passing through the flow meter <NUM>. As another example, the amount of material applied to the substrate may be measured according to a differential in the weight of the remaining material in the pressurized liquid supply <NUM>. The amount of material may be measured as a volume of material and/or a weight of the material.

At step <NUM>, it may be determined whether the amount of material dispensed in step <NUM> is outside or within a predetermined control range. In some embodiments, it may be determined that the amount of the material dispensed in step <NUM> is within an inner predetermined control range that is, for example, ±<NUM>% of the desired amount to be dispensed. For example, it may be determined that too much or too little material was applied to the substrate <NUM>. In one aspect, it may be determined whether the volume of the material is outside or within a predetermined volume control range. In another aspect, it may be determined whether the weight of the material is outside or within a predetermined weight control range. If the amount of the material is outside the predetermined control range, the process <NUM> may proceed to step <NUM>.

In one embodiment, the amount of material dispensed in step <NUM> may be compared against an outer predetermined control range, wherein the outer predetermined control range is broader in at least some respect than the predetermined control range (e.g., the predetermined control range is a subset of the outer predetermined control range). For example, the outer predetermined control range may be ±<NUM>% of the desired amount to be dispensed. If the amount of material is outside of the outer predetermined control range, a stop signal may be generated to stop the dispensing of the material or an indication that the amount of material is outside of the outer predetermined control range may be generated and communicated, such as via a display of other visual indicator of the HMI device <NUM>, to an operator. In an aspect, the indication may comprise an audio alert generated by the HMI device <NUM>.

At step <NUM>, the velocity of the applicator <NUM> relative to the substrate may be adjusted according to the determination that the amount of material is outside of the predetermined control range, and optionally, the degree to which the amount of material is outside of the predetermined control range. As will be appreciated by one skilled in the art, with all other relevant factors (e.g., flow rate) being constant, adjusting the velocity that the applicator <NUM> moves while applying the material will correspondingly adjust the amount of material applied to the substrate <NUM>. As an example, if it is determined that the amount of material applied to the substrate <NUM> in step <NUM> exceeds the upper limit of the predetermined control range by a certain amount, the velocity of the applicator <NUM> may be increased to dispense material in a reduced amount corresponding to the certain amount by which the upper limit of the predetermined control range was exceeded.

In some embodiments, one or more other parameters affecting the amount of material applied to the substrate <NUM> may additionally or alternatively be adjusted. In an aspect, the pulse rate of the applicator <NUM> may be adjusted. If the pulse rate of the applicator <NUM> is increased, for example, more material will be applied to the substrate <NUM>. In another aspect, the temperature of the material may be adjusted. For example, the temperature of the material may be adjusted by operation of the temperature controller <NUM> and heating elements 38a disposed in the pressurized liquid supply <NUM>, by operation of a heating element disposed in one of the conduits <NUM>, <NUM>, <NUM>, and/or by operation of a heating element in the applicator <NUM>. As the viscosity of the material may be affected by temperature and the flow rate of the material may be affected by the viscosity, it follows that the amount of material dispensed from the applicator <NUM>, and thus applied to the substrate <NUM>, may be affected by the temperature of the material.

As the velocity of the applicator <NUM> or other parameter affecting the amount of material is adjusted in each iteration of the flow control routine, a sum of the adjustments may be determined and stored, such as by the controller <NUM> and/or memory <NUM>. The sum of the adjustments, in one aspect, may be the sum of the absolute amount or degree of adjustments thus far in the flow control routine. For example, in an embodiment in which the temperature of the material is adjusted to affect the amount of material applied, the sum of adjustments may comprise the running total of degrees by which the temperature was adjusted (either raised or lowered) in the flow control routine. In another aspect, the sum of adjustments may comprise the number of times in the flow control routine that the parameter affecting the amount of material is adjusted, irrespective of the amount or degree to which the parameter is adjusted.

At step <NUM>, the sum of adjustments to the velocity of the applicator <NUM> or other parameter affecting the amount of material applied to the substrate <NUM> is compared to a predetermined threshold. The predetermined threshold may correspond to a value at which it may be inferred that the fan width of the material dispensed from the applicator <NUM> may have changed and requires adjustment. If the sum of adjustments does not exceed the predetermined threshold, another iteration of the flow control routine may be initiated at step <NUM>. If the sum of adjustments does exceed the predetermined threshold, a fan width control routine may be initiated.

At step <NUM>, a fan width control routine is invoked to adjust the fan width of the material dispensed from the applicator <NUM>. For example, the width and/or shape of the fan may be determined, such as via the fan width sensor <NUM>, and compared to a predetermined fan width control range. If the width and/or shape of the fan are outside the predetermined fan width control range, the width and/or shape of the fan may be adjusted accordingly to bring the width and/or shape of the fan within the predetermined fan width control range. The width and/or shape of the fan may be adjusted, for example, by interaction with an assist fluid, such as air, supplied from the pressurized fluid supply <NUM> and regulated by the fluid regulator <NUM>. The fan width control routine may include a single adjustment to the fan or may include an iterative process in which successive comparisons of the fan to the predetermined fan width control range and corresponding adjustments are performed.

In some aspects, the pressure of the material supplied to the applicator <NUM> may be adjusted, which in turn, may affect the width and/or shape of the fan. For example, under command of the controller <NUM>, the operation of the pump of the pressurized liquid supply <NUM> may be adjusted to increase or decrease the pressure of the material supplied to the applicator <NUM>. In another aspect, the relative position and/or distance between the substrate <NUM> and the applicator <NUM> may be adjusted to alter the width and/or shape of the fan of material dispensed from the applicator <NUM>. For example, the controller <NUM> and/or motion controller <NUM> may direct the robot <NUM> to position the applicator <NUM> at an increased distance from the substrate <NUM>, thus increasing the width of the fan of material at the point of contact with the substrate <NUM>. In yet another aspect, the shape and/or size of the dispensing orifice in the nozzle <NUM> may be adjusted to affect the shape and/or width of the fan of the material passing through the dispensing orifice.

Further, the flow control routine of steps <NUM> - <NUM> and/or the fan width control routine of step <NUM> may be additionally repeated one or more times to iteratively compensate for any variations in flow rate and/or amount of material applied to the substrate <NUM> caused by the fan width control routine of step <NUM>. For example, if an adjustment to the pressure of the material was made in the preceding fan width control routine of step <NUM>, the subsequent flow rate and/or amount of material applied to the substrate <NUM> may be rechecked and, if necessary (e.g., is outside of a predetermined control range), adjusted. A further fan width control routine of step <NUM> may be subsequently performed. This iterative process may be continued until both the flow rate and/or amount of material applied to the substrate <NUM> and the fan width and/or shape of the fan are within the respective predetermined control ranges.

Upon completion of the fan width control routine, at step <NUM>, additional substrates <NUM> may be coated with the material according to the adjustments made in the process <NUM>. The process <NUM> may be considered an iterative process. For example, as additional substrates <NUM> are coated in step <NUM>, this may also be considered as restarting the process <NUM> at step <NUM>, whereby the flow control routine of steps <NUM> - <NUM> may continue to iteratively adjust the velocity of the applicator <NUM> as it coats the additional substrates <NUM>, and so forth.

<FIG> illustrates a flow diagram of an exemplary process <NUM> of coating one or more substrates <NUM> with a material, such as a liquid coating material. The process <NUM> may be executed, at least in part, by the motion controller <NUM> and/or controller <NUM>. By way of introduction, the process <NUM> includes a fan width control routine (steps <NUM> - <NUM>), wherein the fan width of the material dispensed by the applicator <NUM>, or in addition to the fan width other parameter affecting the fan width, is iteratively adjusted. When the sum of the adjustments in the fan width control routine exceed a predetermined threshold (step <NUM>), which may indicate that the amount of material dispensed and applied to the substrate <NUM> has changed, a flow control routine (step <NUM>) may be initiated to adjust the velocity of the applicator <NUM> or other parameter relating to the amount of material dispensed and applied to the substrate <NUM>.

At step <NUM>, a substrate <NUM>, or portion thereof, may be coated with the material and the amount of material may be measured. For example, the flow meter <NUM> may measure the amount of material passing from the pressurized liquid supply <NUM> to the applicator <NUM> and transmit the measured amount to the controller <NUM> for processing and storage. The amount of material may be measured by volume or weight.

At step <NUM>, whether the amount of material applied to the substrate <NUM> in step <NUM> is outside or within a predetermined control range may be determined, such as by the controller <NUM>. In some embodiments, it may be determined that the amount of the material dispensed in step <NUM> is within an inner predetermined control range that is, for example, be ±<NUM>% of the desired amount to be dispensed. For example, it may be determined that too much material was applied to the substrate <NUM> or that too little material was applied to the substrate <NUM>. In one aspect, it may be determined whether the volume of the material is outside or within a predetermined volume control range. In another aspect, it may be determined whether the weight of the material is outside or within a predetermined weight control range. If the amount of the material is outside the predetermined control range, the process <NUM> may proceed to step <NUM>.

In one embodiment, the amount of material dispensed in step <NUM> may be compared against an outer predetermined control range, wherein the outer predetermined control range is broader in at least some respect than the predetermined control range (i.e., the predetermined control range is a subset of the outer predetermined control range). For example, the outer predetermined control range may be ±<NUM>% of the desired amount to be dispensed. If the amount of material is outside of the outer predetermined control range, a stop signal may be generated to stop the dispensing of the material or an indication that the amount of material is outside of the outer predetermined control range may be generated and communicated, such as via the HMI device <NUM>, to an operator.

At step <NUM>, the fan width of the material dispensed from the applicator <NUM> may be adjusted based on the determination that the amount of material is outside the predetermined control range, and optionally, the degree to which the amount of material is outside the predetermined control range. In an aspect, the fan width may be adjusted by adjusting the pressure of the material supplied to the applicator <NUM>. For example, under command of the controller <NUM>, the operation of the pump of the pressurized liquid supply <NUM> may be adjusted to increase or decrease the pressure of the material supplied to the applicator <NUM>. In another aspect, the relative position and/or distance between the substrate <NUM> and the applicator <NUM> may be adjusted to alter the width and/or shape of the fan of material dispensed from the applicator <NUM>. For example, the controller <NUM> and/or motion controller <NUM> may direct the robot <NUM> to position the applicator <NUM> at an increased distance from the substrate <NUM>, thus increasing the width of the fan of material at the point of contact with the substrate <NUM>. In yet another aspect, the shape and/or size of the dispensing orifice in the nozzle <NUM> may be adjusted to affect the shape and/or width of the fan of the material passing through the dispensing orifice.

As the fan width of the material dispensed from the applicator <NUM>, or other parameter affecting the fan width, is adjusted in each iteration of the fan width control routine, the sum of the adjustments may be determined and stored, such as by the controller <NUM> and/or memory <NUM>. The sum of the adjustments, in one aspect, may be the sum of the absolute amount or degree of adjustments thus far in the fan width control routine. In another aspect, the sum of adjustments may comprise the number of times in the fan width control routine that the parameter affecting the fan width is adjusted, irrespective of the amount or degree to which the parameter is adjusted.

At step <NUM>, the sum of the adjustments to the fan width or other parameter affecting the fan width is compared to a predetermined threshold. The predetermined threshold may correspond to a value at which the amount of material applied to the substrate <NUM> may require adjustment. In one aspect, the predetermined threshold may correspond to a value at which the thickness of the material applied to the substrate <NUM> may require adjustment. For example, if the width of the fan was increased in the fan width control routine without a corresponding increase in the flow of the material (i.e., the amount of material) to the applicator <NUM> or a decrease in the velocity of the applicator <NUM>, the thickness of the coating of material on the substrate <NUM> may not be as thick as desired. Accordingly, the flow of the material may need to be increased and/or the velocity of the applicator <NUM> may need to be decreased to provide the desired coating thickness. If the sum of adjustments does not exceed the predetermined threshold, another iteration of the fan width control routine may be initiated at step <NUM>. If the sum of adjustments does exceed the predetermined threshold, a flow control routine may be initiated.

At step <NUM>, a flow control routine may be initiated to adjust the velocity of the applicator <NUM> or other parameter affecting the amount and/or thickness of material applied to the substrate <NUM>. Other parameters affecting the amount and/or thickness of material applied to the substrate <NUM> may include a pulse rate of the applicator <NUM> or the temperature of the material. The flow control routine may include a comparison of the amount and/or thickness of material applied to the substrate <NUM> with a predetermined control range. According to the comparison, the velocity of the applicator <NUM>, the pulse rate of the applicator <NUM>, the temperature of the material, and/or other parameter relating to the amount and/or thickness of material to the substrate <NUM> may be adjusted. The flow control routine may include a single adjustment or may include an iterative process in which successive comparisons of the amount and/or thickness of material to the predetermined control range and corresponding adjustments are performed.

Upon completion of the flow control routine, at step <NUM>, additional substrates <NUM> may be coated with the material according to the adjustments made in the process <NUM>. The process <NUM> may be considered an iterative process. For example, as additional substrates <NUM> are coated in step <NUM>, this may also be considered as restarting the process <NUM> at step <NUM>, whereby the fan width control routine of steps <NUM> - <NUM> may continue to iteratively adjust the fan width, and so forth.

<FIG> illustrates a flow diagram of an exemplary process <NUM> of coating one or more substrates <NUM> with a material, such as a liquid coating material. The process <NUM> may be executed, at least in part, by the motion controller <NUM> and/or controller <NUM>. By way of introduction, the process <NUM> includes combined fan width and flow control routine (steps <NUM> - <NUM>) wherein the fan width of the material dispensed by the applicator <NUM>, or other parameter affecting the fan width, and the amount and/or thickness of the material applied to the substrate <NUM> are simultaneously and iteratively adjusted.

At step <NUM>, it may be determined, such as by the controller <NUM>, whether the amount of material applied to the substrate <NUM> is outside or within a predetermined control range. In some embodiments, it may be determined that the amount of the material dispensed in step <NUM> is within an inner predetermined control range that is, for example, ±<NUM>% of the desired amount to be dispensed. If the amount of the material is within (i.e., not outside) the predetermined control range, the process may proceed to step <NUM> and additional substrates <NUM> may be coated.

In some embodiments, it may be determined that too much or too little material was applied to the substrate <NUM>. In one aspect, it may be determined whether the volume of the material is outside or within a predetermined volume control range. In another aspect, it may be determined whether the weight of the material is outside or within a predetermined weight control range. If the amount of the material is outside the predetermined control range, the process <NUM> may proceed to steps <NUM> and <NUM>.

In one embodiment, the amount of material dispensed in step <NUM> may be compared against an outer predetermined control range, wherein the outer predetermined control range is broader in at least some respect than the predetermined control range (e.g., the predetermined control range is a subset of the outer predetermined control range). For example, the outer predetermined control range may be ±<NUM>% of the desired amount to be dispensed. If the amount of material is outside of the outer predetermined control range, a stop signal may be generated to stop the dispensing of the material or an indication that the amount of material is outside of the outer predetermined control range may be generated and communicated, such as via the HMI device <NUM>, to an operator.

At step <NUM>, a flow control routine may be invoked in which the velocity of the applicator <NUM> or other parameter affecting the amount and/or thickness of material applied to the substrate <NUM> may be adjusted. Other parameters affecting the amount and/or thickness of material applied to the substrate <NUM> may include a velocity of the applicator <NUM>, a pulse rate of the applicator <NUM> or the temperature of the material, a fan width of the applicator <NUM>. The flow control routine may include a comparison of the amount and/or thickness of material applied to the substrate <NUM> with a predetermined control range. According to the comparison, the velocity of the applicator <NUM>, the pulse rate of the applicator <NUM>, the temperature of the material, and/or the fan width of the applicator <NUM> may be adjusted. The flow control routine may include a single adjustment or may include an iterative process in which successive comparisons of the amount and/or thickness of material to the predetermined control range and corresponding adjustments are performed.

At step <NUM>, which may occur concurrently with step <NUM>, a fan width control routine is invoked in which the fan width or other parameter affecting the fan width is adjusted. The fan width control routine may include a comparison of the width and/or shape of the fan of material dispensed from the applicator <NUM> with a predetermined fan width control range. If the width and/or shape of the fan are outside the predetermined fan width control range, the width and/or shape of the fan may be adjusted accordingly to bring the width and/or shape of the fan within the predetermined fan width control range. The fan width control routine may include a single adjustment to the fan or may include an iterative process in which successive comparisons of the fan to the predetermined fan width control range and corresponding adjustments are performed.

Upon completion of the flow control routine of step <NUM> and the fan width control routine of step <NUM>, the process <NUM> may return to step <NUM> and additional iterations of steps <NUM>, <NUM>, <NUM>, and <NUM> may be repeated with additional substrates <NUM>, or portions thereof, until the amount of material applied to the respective substrate <NUM> is not outside the predetermined control range in step <NUM>, upon which the process may proceed to step <NUM>. In some aspects, the process <NUM> may return to step <NUM> and additional iterations of steps <NUM>, <NUM>, <NUM>, <NUM> may be performed with respect to the same substrate <NUM>, or portions thereof, before proceeding to coat additional substrates <NUM>. By adjusting both the velocity of the applicator <NUM> and the fan width, the adjustment of each parameter will be relatively less than the adjustment of a single parameter to achieve the same changes in amount of the material dispensed. At step <NUM>, additional substrates <NUM> may be coated according to the various adjusted parameters of steps <NUM> and <NUM>.

<FIG> illustrates a flow diagram of an exemplary process <NUM> of coating one or more substrates <NUM> with a material. The process <NUM> may be executed, at least in part, by the motion controller <NUM> and/or controller <NUM>. The process <NUM> may be used as a calibration method. By way of introduction, the process <NUM> includes a fan width control routine (steps <NUM> - <NUM>) in which the fan width of the material, or other parameter affecting the fan width, is adjusted. Following the fan width control routine, the material may be dispensed for a predetermined period of time (step <NUM>) and a flow control routine (steps <NUM> - <NUM>) may be invoked, in which the velocity of the applicator <NUM>, or other parameter affecting the amount of material dispensed, is adjusted.

At step <NUM>, a material is dispensed from the applicator <NUM>. For example, a substrate <NUM>, or portion thereof, may be coated with the material. In another example, the material may be dispensed in a waste bin as part of a calibration routine. As the substrate <NUM> is coated with the material, the amount of material may be measured. The amount of material may be measured by weight or by volume.

At step <NUM>, it may be determined whether the amount of material applied to the substrate <NUM> in step <NUM> is outside or within a first predetermined control range. In some embodiments, it may be determined that the amount of the material dispensed in step <NUM> is within an inner predetermined control range that is, for example, be ±<NUM>% of the desired amount to be dispensed. If the amount of material is outside the first predetermined control range, the process <NUM> may proceed to step <NUM>.

In one embodiment, the amount of material dispensed in step <NUM> may be compared against a first outer predetermined control range, wherein the first outer predetermined control range is broader in at least some respect than the first predetermined control range (e.g., the first predetermined control range is a subset of the first outer predetermined control range). For example, the first outer predetermined control range may be ±<NUM>% of the desired amount to be dispensed. If the amount of material is outside of the first outer predetermined control range, a stop signal may be generated to stop the dispensing of the material or an indication that the amount of material is outside of the first outer predetermined control range may be generated and communicated, such as via the HMI device <NUM>, to an operator.

At step <NUM>, the fan width of the material dispensed from the applicator <NUM> is adjusted based on the determination that the amount of material is outside the first predetermined control range, and optionally, the degree to which the amount of material is outside the first predetermined control range. In an aspect, the fan width may be adjusted by adjusting the pressure of the material supplied to the applicator <NUM>. In another aspect, the relative position and/or distance between the substrate <NUM> and the applicator <NUM> may be adjusted to alter the width and/or shape of the fan of material dispensed from the applicator <NUM>. In yet another aspect, the shape and/or size of the dispensing orifice in the nozzle <NUM> may be adjusted to affect the shape and/or width of the fan of the material passing through the dispensing orifice.

At step <NUM>, material may be dispensed from the applicator <NUM> for a predetermined period of time. As the material is dispensed during the predetermined period of time, the amount of material may be measured, such as by weight or volume.

At step <NUM>, it may be determined whether the amount of material dispensed in step <NUM> is outside or within a second predetermined control range. If the amount of material is outside the second predetermined control range, the process <NUM> may proceed to step <NUM>.

In one embodiment, the amount of material dispensed in step <NUM> may be compared against a second outer predetermined control range, wherein the second outer predetermined control range is broader in at least some respect than the second predetermined control range (e.g., the second predetermined control range is a subset of the second outer predetermined control range). For example, the second outer predetermined control range may be ±<NUM>% of the desired amount to be dispensed. If the amount of material is outside of the second outer predetermined control range, a stop signal may be generated to stop the dispensing of the material or an indication that the amount of material is outside of the second outer predetermined control range may be generated and communicated, such as via the HMI device <NUM>, to an operator.

At step <NUM>, the velocity of the applicator <NUM>, or other parameter affecting the amount of material dispensed, may be adjusted based on the determination that the amount of material is outside the second predetermined control range, and optionally, the degree to which the amount of material is outside the second predetermined control range. Other parameters affecting the amount and/or thickness of material applied to the substrate <NUM> may include a pulse rate of the applicator <NUM> or the temperature of the material.

At step <NUM>, one or more additional substrates <NUM>, or portions thereof, may be coated. To the extent that process <NUM> may be used as a calibration method prior to beginning a "production" process of coating substrates <NUM>, the substrate <NUM> coated in step <NUM> may comprise a test substrate <NUM>, while the additional substrates <NUM> coated in step <NUM> may comprise "production" substrates <NUM> (e.g., those substrates <NUM> that are intended to be sold or included in a manufactured product).

<FIG> illustrates a flow diagram of an exemplary process <NUM> of coating one or more substrates <NUM> with a material. The process <NUM> may be executed, at least in part, by the motion controller <NUM> and/or controller <NUM>. The process <NUM> may be used as a calibration method, such as when the dispensed material is being changed from a first material to a second material (i.e., a material changeover). Initially, at step <NUM> a first material is dispensed from the applicator <NUM>. For example a first substrate <NUM> is coated with a first material according to a first pulse rate, a first temperature of the material, a first pressure of the material supplied to the applicator, and a first fan width. In another example, the first material may be dispensed in a waste bin as part of a calibration routine. A second, different material is then received.

At step <NUM>, the second material may be dispensed from the applicator <NUM> for a predetermined period of time. As the second material is dispensed during the predetermined period of time, the amount of material may be measured, such as by weight or volume.

At step <NUM>, it may be determined whether the amount of the second material dispensed in step <NUM> is outside or within a predetermined control range. If the amount of material is outside the predetermined control range, the process <NUM> may proceed to step <NUM>.

In one embodiment, the amount of the second material dispensed in step <NUM> may be compared against an outer predetermined control range, wherein the outer predetermined control range is broader in at least some respect than the predetermined control range (e.g., the predetermined control range is a subset of the outer predetermined control range). For example, the outer predetermined control range may be ±<NUM>% of the desired amount to be dispensed. If the amount of the second material is outside of the outer predetermined control range, a stop signal may be generated to stop the dispensing of the second material or an indication that the amount of the second material is outside of the outer predetermined control range may be generated and communicated, such as via the HMI device <NUM>, to an operator.

At step <NUM>, a parameter affecting the amount of the second material dispensed, may be adjusted based on the determination that the amount of the second material is outside the predetermined control range, and optionally, the degree to which the amount of the second material is outside the predetermined control range. The parameters affecting the amount and/or thickness of material applied to the substrate <NUM> may include a velocity of the applicator <NUM>, a pulse rate of the applicator <NUM>, a temperature of the second material, a pressure of the second material supplied to the applicator <NUM>, and include a first fan width of the applicator.

At step <NUM>, one or more additional substrates <NUM>, or portions thereof, may be coated with the second material according to the adjusted parameters. To the extent that process <NUM> may be used as a calibration method prior to beginning a "production" process of coating substrates <NUM>, the substrate <NUM> coated in step <NUM> may comprise a test substrate <NUM>, while the additional substrates <NUM> coated in step <NUM> may comprise "production" substrates <NUM> (e.g., those substrates <NUM> that are intended to be sold or included in a manufactured product).

Claim 1:
A method of applying a material to a substrate (<NUM>), the method comprising:
coating a first substrate (<NUM>) with the material using an applicator (<NUM>);
determining, in response to completion of the coating of the first substrate (<NUM>)with the material, a first total amount of the material applied to the first substrate (<NUM>);
comparing the first total amount of the material applied to the first substrate (<NUM>) to a first predetermined control range;
determining, in response to the comparison of the first total amount of the material applied to the first substrate (<NUM>) to the first predetermined control range, that the first total amount of the material applied to the first substrate (<NUM>) is outside of the first predetermined control range;
adjusting, in response to the determination that the first total amount of the material applied to the first substrate (<NUM>) is outside of the first predetermined control range, (<NUM>) a velocity of the applicator, a pulse rate of the applicator, or a temperature of the material by a first adjustment amount, and (<NUM>) a fan width of the applicator (<NUM>) by a second adjustment amount to change a total amount of material applied to a subsequent, second substrate (<NUM>);
coating the second substrate (<NUM>) with the material using the applicator (<NUM>);
determining, in response to completion of the coating of the second substrate (<NUM>) with the material, a second total amount of the material applied to the second substrate (<NUM>);
comparing the second total amount of the material applied to the second substrate (<NUM>) to the first predetermined control range; and
determining, in response to the comparison of the second total amount of the material applied to the second substrate (<NUM>) to the first predetermined control range, that the second total amount of the material applied to the second substrate (<NUM>) is within the first predetermined control range.