U.S. patent application number 16/125747 was filed with the patent office on 2019-01-03 for dual applicator fluid dispensing methods and systems.
The applicant listed for this patent is NORDSON CORPORATION. Invention is credited to Christopher L. Giusti, Philip P. Maiorca, Mark S. Meier, David N. Padgett.
Application Number | 20190001361 16/125747 |
Document ID | / |
Family ID | 53716585 |
Filed Date | 2019-01-03 |
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United States Patent
Application |
20190001361 |
Kind Code |
A1 |
Giusti; Christopher L. ; et
al. |
January 3, 2019 |
DUAL APPLICATOR FLUID DISPENSING METHODS AND SYSTEMS
Abstract
Method of dispensing fluid are disclosed. The method initially
determines, based upon an image of a first electronic substrate,
that a first or a second dispense region is misaligned relative to
the other of the first or the second dispense region. Fluid is
dispensed from a first applicator while moving the first applicator
using a primary positioner on the first electronic substrate to
form a first fluid pattern. Fluid is simultaneously dispensed from
a second applicator while moving the second applicator using the
primary positioner and a secondary positioner. The method then
determines, based upon an image of a second electronic substrate,
that a first and a second dispense region of the second electronic
substrate are aligned relative to one another. Fluid is
simultaneously dispensed from the first applicator and the second
applicator while moving the first applicator and the second
applicator together using the primary positioner with first
applicator.
Inventors: |
Giusti; Christopher L.; (San
Marcos, CA) ; Maiorca; Philip P.; (Poway, CA)
; Meier; Mark S.; (Encinitas, CA) ; Padgett; David
N.; (Carlsbad, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
NORDSON CORPORATION |
WESTLAKE |
OH |
US |
|
|
Family ID: |
53716585 |
Appl. No.: |
16/125747 |
Filed: |
September 9, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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15624932 |
Jun 16, 2017 |
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16125747 |
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14326722 |
Jul 9, 2014 |
9707584 |
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15624932 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B05B 12/124 20130101;
H01L 21/67333 20130101; B05C 5/0216 20130101; B05C 5/027 20130101;
B05C 13/02 20130101; B05C 11/1021 20130101; B05B 13/0442 20130101;
B05D 1/02 20130101; B05B 3/00 20130101; B05C 11/1018 20130101 |
International
Class: |
B05B 12/12 20060101
B05B012/12; B05D 1/02 20060101 B05D001/02; B05B 13/04 20060101
B05B013/04; B05B 3/00 20060101 B05B003/00 |
Claims
1. A method of dispensing fluid, the method comprising: capturing
at least one image of a plurality of dispense regions provided on
an XY plane of one or more first electronic substrates; selecting,
from the at least one image of the one or more first electronic
substrates, first and second dispense regions of the plurality of
dispense regions of the one or more first electronic substrates;
determining, based upon the at least one image of the one or more
first electronic substrates, that the first or the second dispense
region of the one or more first electronic substrates is misaligned
relative to the other of the first or the second dispense region of
the one or more first electronic substrates; dispensing fluid from
a first applicator while moving the first applicator, using a
primary positioner, above and along the XY plane of the one or more
first electronic substrates to form a first fluid pattern at the
first dispense region of the one or more first electronic
substrates; dispensing fluid from a second applicator,
simultaneously with the dispensing of the fluid from the first
applicator, while moving the second applicator, using the primary
positioner and a secondary positioner, above and along the XY plane
of the one or more first electronic substrates and relative to the
first applicator to form a second fluid pattern at the second
dispense region of the one or more first electronic substrates;
capturing at least one image of a plurality of dispense regions
provided on an XY plane of one or more second electronic
substrates; selecting, from the at least one image of the one or
more second electronic substrates, first and second dispense
regions of the plurality of dispense regions of the one or more
second electronic substrates; determining, based upon the at least
one image of the one or more second electronic substrates, that the
first and second dispense regions of the one or more second
electronic substrates are aligned relative to one another;
dispensing fluid from the first applicator while moving the first
applicator, using the primary positioner, above and along the XY
plane of the one or more second electronic substrates to form the
first fluid pattern at the first dispense region of the one or more
second electronic substrates; and dispensing fluid from the second
applicator, simultaneously with the dispensing of the fluid from
the first applicator, while moving the second applicator together
with first applicator, using the primary positioner, above and
along above the XY plane of the one or more second electronic
substrates to form the second fluid pattern at the second dispense
region of the one or more second electronic substrates.
2. The method of claim 1, further comprising assigning the first
applicator to the first dispense region and the second applicator
to the second dispense region of the one or more first electronic
substrates prior to dispensing fluid to the one or more first
electronic substrates.
3. The method of claim 1, further comprising assigning the first
applicator to the first dispense region and the second applicator
to the second dispense region of the one or more second electronic
substrates prior to dispensing fluid to the one or more second
electronic substrates.
4. The method of claim 1, wherein determining that the first or the
second dispense region of the one or more first electronic
substrates is misaligned relative to the other of the first or the
second dispense region of the one or more first electronic
substrates comprises determining that the first or the second
dispense region of the one or more first electronic substrates is
rotated relative to the other of the first or the second dispense
region of the one or more first electronic substrates.
5. The method of claim 1, wherein determining that the first and
the second dispense regions of the one or more second electronic
substrates are aligned relative to one another comprises
determining that the first and the second dispense regions of the
one or more second electronic substrates are not rotated relative
to one another.
6. The method of claim 1, wherein the first fluid pattern and the
second fluid pattern are substantially identical in size and
shape.
7. The method of claim 1, wherein dispensing fluid from the second
applicator while moving the second applicator, using the primary
positioner and the secondary positioner, to form the second fluid
pattern at the second dispense region of the one or more first
electronic substrates occurs subsequently and in response to
determining that the first or the second dispense region of the one
or more first electronic substrates is misaligned relative to the
other of the first or the second dispense region of the one or more
first electronic substrates.
8. The method of claim 1, wherein dispensing fluid from the second
applicator while moving the second applicator together with first
applicator, using the primary positioner, to form the second fluid
pattern at the second dispense region of the one or more second
electronic substrates occurs subsequently and in response to
determining that the first and second dispense regions are aligned
relative to one another.
9. The method of claim 1, wherein dispensing fluid from the second
applicator to form the second fluid pattern at the second dispense
region of the one or more second electronic substrates includes
moving the second applicator together with the first applicator,
using the primary positioner, in at least one of an X axis
direction and a Y axis direction, which is orthogonal to the X axis
direction, without providing relative movement between the first
applicator and the second applicator, using the secondary
positioner, in the X axis direction or the Y axis direction.
10. The method of claim 1, wherein dispensing fluid from the second
applicator to form the second fluid pattern at the second dispense
region of the one or more first electronic substrates includes
moving the second applicator relative to the first applicator,
using the secondary positioner, in at least one of an X axis
direction and a Y axis direction, which is orthogonal to the X axis
direction.
11. The method of claim 10, wherein dispensing fluid from the
second applicator to form the second fluid pattern at the second
dispense region of the one or more first electronic substrates
includes moving the second applicator relative to the first
applicator, using the secondary positioner, in both the X axis
direction and the Y axis direction.
12. The method of claim 1, wherein determining that the first or
the second dispense region of the one or more first electronic
substrates is misaligned relative to the other of the first or the
second dispense region of the one or more first electronic
substrates is based upon identifying reference fiducials associated
with the first and the second dispense regions of the one or more
first electronic substrates from the at least one image of the one
or more first electronic substrates.
13. The method of claim 1, wherein determining that the first and
the second dispense regions of the one or more second electronic
substrates are aligned relative to one another is based upon
identifying reference fiducials associated with the first and the
second dispense regions of the one or more second electronic
substrates from the at least one image of the one or more second
electronic substrates.
14. The method of claim 1, further comprising, prior to dispensing
fluid from the first applicator to form the first fluid pattern at
the first dispense region of the one or more first electronic
substrates and prior to dispensing fluid from the second applicator
to form the second fluid pattern at the second dispense region of
the one or more first electronic substrates: positioning the first
applicator in the XY plane of the one or more first electronic
substrates above a first dispense site at the first dispense region
of the one or more first electronic substrates and simultaneously
positioning the second applicator in the XY plane of the one or
more first electronic substrates to position the second applicator
above a first dispense site at the second dispense region of the
one or more first electronic substrates.
15. The method of claim 14, wherein: the positioning of the first
applicator above the first dispense site at the first dispense
region of the one or more first electronic substrates includes
moving the first applicator, using the primary positioner, in at
least one of an X axis direction and a Y axis direction, which is
orthogonal to the X axis direction, and simultaneously positioning
the second applicator above the first dispense site at the second
dispense region of the one or more first electronic substrates
includes moving the second applicator together with the first
applicator using the primary positioner and moving the second
applicator relative to the first applicator using the secondary
positioner in at least one of the X axis direction and the Y axis
direction.
16. The method of claim 1, further comprising, prior to dispensing
fluid from the first applicator to form the first fluid pattern at
the first dispense region of the one or more second electronic
substrates and prior to dispensing fluid from the second applicator
to form the second fluid pattern at the second dispense region of
the one or more second electronic substrates: positioning the first
applicator in the XY plane of the one or more second electronic
substrates above a first dispense site at the first dispense region
of the one or more second electronic substrates and simultaneously
positioning the second applicator in the XY plane of the one or
more second electronic substrates to position the second applicator
above a first dispense site at the second dispense region of the
one or more second electronic substrates.
17. The method of claim 16, wherein: the positioning of the first
applicator above the first dispense site at the first dispense
region of the one or more second electronic substrates includes
moving the first applicator, using the primary positioner, in at
least one of an X axis direction and a Y axis direction, which is
orthogonal to the X axis direction, and simultaneously positioning
the second applicator above the first dispense site at the second
dispense region of the one or more second electronic substrates
includes moving the second applicator together with the first
applicator using the primary positioner and moving the second
applicator relative to the first applicator using the secondary
positioner in at least one of the X axis direction and the Y axis
direction.
18. The method of claim 1, wherein the first applicator is mounted
to the primary positioner and the second applicator is mounted to
the secondary positioner.
19. The method of claim 18, wherein the secondary positioner is
operatively coupled with and movable relative to the primary
positioner.
20. The method of claim 1, wherein the first applicator and the
second applicator are each operatively coupled to a carriage of the
primary positioner, the carriage being configured to move both the
first applicator and the second applicator in at least one of an X
axis direction and a Y axis direction, which is orthogonal to the X
axis direction.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 15/624,932, filed Jun. 16, 2017, and published
as U.S. Patent App. Pub. No. 2017/0282207 on Oct. 5, 2017, which is
a divisional of U.S. patent application Ser. No. 14/326,722, filed
Jul. 9, 2014, and issued as U.S. Pat. No. 9,707,584 on Jul. 18,
2017, which are hereby incorporated by reference herein.
TECHNICAL FIELD
[0002] The present invention relates generally to dispensing
viscous fluids, and more particularly to dispensing viscous fluids
at multiple dispense regions simultaneously with multiple fluid
applicators.
BACKGROUND
[0003] In the manufacture of electronic substrates, such as printed
circuit boards ("PCB") for example, it is frequently necessary to
apply small, precise amounts of viscous fluids, i.e., those with a
viscosity greater than 50 centipoise. Such fluids may include
adhesives, solder paste, solder flux, solder mask, underfill
material, encapsulants, potting compounds, epoxies, die attach
pastes, silicones, RTV, or cyanoacrylates, for example.
[0004] Automated fluid dispensing systems are often used for
dispensing patterns of such viscous fluids onto substrates with a
high degree of accuracy, repeatability, and efficiency. As used
herein, the term "fluid pattern," and variations thereof, refers to
one or more lines, arcs, dots, combinations thereof, and/or any
other configuration of continuously or intermittently dispensed
fluid. Traditional fluid dispensing systems include a fluid
applicator, also referred to as a dispenser or valve, mounted to a
gantry which is movable for positioning the applicator as desired
along three mutually orthogonal axes (X, Y, Z) above one or more
substrates positioned generally in the horizontal XY plane. The
gantry is generally movable with drive mechanisms controlled by a
computer system or other controller. A moving conveyor, generally
aligned with the X axis of the dispensing system, may be used to
sequentially deliver pluralities of substrates to a location
generally beneath a fluid dispensing system. The pluralities of
substrates are often organized into and carried by carrier trays,
such as a JEDEC tray. The dispensing system may then be operated to
dispense a pre-programmed pattern of fluid onto the substrates.
[0005] To dispense a pattern of fluid onto one or more substrates
held in a carrier tray, the controller first determines the
location and orientation of the substrates in the
horizontally-oriented XY plane in which the substrates generally
lie. A camera mounted to the gantry scans the substrates and
captures visual images of reference fiducials provided on the top
surfaces of each substrate by traveling along a path that moves
across the pre-programmed locations of the reference fiducials
which are known by the controller. Based on these captured visual
images, the controller determines the actual location and
orientation of each substrate in the XY plane. A height sensor,
also mounted to the gantry, measures the position of each substrate
along the vertically-oriented Z axis for determining a proper
dispense height at which a dispensing tip of the applicator should
be positioned when dispensing onto the substrate. The controller
then operates the gantry to move the applicator along the X and Y
axes until the applicator is properly positioned in the XY plane
over a desired region of a substrate positioned below. The
applicator is then lowered along the Z axis until the dispensing
tip is at the proper dispensing height, at which point the
applicator then dispenses the pre-programmed fluid pattern onto the
substrate. Upon completion of dispensing, the applicator is then
raised back up along the Z axis and may be repositioned in the XY
plane for subsequent dispensing at a new region of the same
substrate or of a new substrate.
[0006] For increased manufacturing throughput, fluid dispensing
systems have been provided with dual fluid applicators for
simultaneously dispensing at first and second dispense regions. As
used herein, the term "dispense region" refers to a general region
or zone at which a fluid pattern is dispensed. For example,
"dispense region" may refer to a substrate generally or it may
refer to a particular region of a substrate. Accordingly, the
phrase "first and second dispense regions," and variations thereof,
may refer to first and second substrates that are physically
independent of each other, or alternatively it may refer to first
and second distinct regions of a single substrate. For example, a
single substrate, such as a panelized substrate, may include a
plurality of distinct regions at which fluid is dispensed.
[0007] With traditional fluid dispensing systems, a first
applicator is positioned and controlled to dispense at a first
dispense region, such as a first substrate, while a second
applicator is simultaneously positioned and controlled to dispense
at a second dispense region, such as a second substrate. On
occasion, the first and second substrates may be rotated in the
same way in the XY plane of the dispensing system (i.e., "globally
rotated") relative to the X and Y axes. Global rotation of the
substrates may occur when the carrier tray in which the substrates
are carried is not aligned with the X and Y axes. Traditional dual
dispensing methods have included steps for making an automated,
one-time positional adjustment of the second applicator relative to
the first applicator along the X and Y axes prior to dispensing to
thereby enable simultaneous dispensing of identical fluid patterns
onto globally rotated first and second substrates.
[0008] However, traditional dual dispensing methods have not
included automatically repositioning the first and second
applicators relative to each other along the X or Y axes while
actively dispensing. In other words, traditional dual dispensing
systems do not perform active, real-time positional adjustments of
the first and second applicators relative to each other in the XY
plane while dispensing. Consequently, traditional dual dispensing
methods have not accomplished accurate simultaneous dispensing of
identical fluid patterns at first and second dispense regions, such
as first and second substrates, that are rotated relative to each
other in the XY plane (i.e., "locally rotated"). For example, a
first rectangular substrate may be aligned parallel with the X and
Y axes and a second rectangular substrate may be rotated in the XY
plane relative to the X and Y axes. Such local rotation may occur
when a substrate is sized smaller than the carrier tray pocket in
which it sits, thereby forming one or more gaps between the outer
perimeter of the substrate and the inner wall of the pocket. The
substrate is thus permitted to rotate within the pocket in the XY
plane, and relative to any one or more adjacent substrates.
Additionally, local rotation may be present among multiple dispense
regions of a single substrate, for example a panelized circuit
board. Traditional dual dispensing methods are deficient in
actively correcting for such local rotation while dispensing.
[0009] Furthermore, traditional dual dispensing methods have not
included actively repositioning the first or second applicator
relative to each other along the vertical Z axis of the dispensing
system while the first and second applicators are dispensing.
Accordingly, traditional dual dispensing systems have not
accomplished accurate dual dispensing at first and second dispense
regions, such as first and second substrates, where the first and
second dispense regions are tilted in the XY plane relative to each
other, or where one of the dispense regions is uniquely contoured
relative to the XY plane, along the Z axis. Thus, dispense regions
that are "rotated" relative to each other may lay in a common XY
reference plane. In contrast, dispense regions that are "tilted"
and/or "contoured" relative to each other do not lie in a common
plane, and the dispense regions are uniquely tilted and/or uniquely
contoured relative to the XY reference plane, as described in
greater detail below in connection with embodiments of the
invention (see e.g., FIG. 13A).
[0010] In illustration of the discussion above, FIG. 1 shows a
carrier tray 10 having a plurality of adjacent pockets 12a, 12b,
12c, and 12d for receiving a corresponding plurality of substrates
14a, 14b, 14c, and 14d. As shown, each substrate 14a-14d may
include a corresponding component 16a, 16b, 16c, and 16d mounted
thereto. Each pocket 12a-12d has a depth in a direction
perpendicular to the XY plane, and is sized and shaped to retain
the corresponding substrate 14a-14d in a centered position and in
proper orientation relative to a global origin O. FIG. 2 shows a
carrier tray 20 in which pockets 22a, 22b, 22c, and 22d are sized
slightly larger than their corresponding substrates 24a, 24b, 24c,
and 24d held therein, such that gaps are created between the outer
perimeter of each substrate A-D and the inner walls of its
corresponding pocket 22a-22d. Accordingly, each substrate 24a-24d
is permitted to shift and thereby become rotated and/or translated
in the XY plane relative to its centered orientation (shown in
phantom) and relative to each of the other substrates 24a-24d.
[0011] FIG. 3 shows the carrier tray 20 and substrates 24a-24d of
FIG. 2, but where substrate 24b is tilted relative to the XY plane.
More specifically, FIG. 3A shows an angular offset between a bottom
surface 26 of substrate 24b and a base surface 28 of its pocket
22b, thereby forming a wedge-shaped gap 25. Such tilting may be
caused by the presence of a foreign material between the bottom
surface 26 and the base surface 28. Alternatively, tilting of a
substrate may occur if the substrate is malformed, for example
through warping. As discussed above, traditional dual dispensing
methods have not accomplished automated, real-time adjustment of
applicator positioning while dispensing so as to accurately
dispense at first and second dispense regions, such as first and
second substrates, that are misaligned in the manners shown in
FIGS. 2-3A. Accordingly, there is a need for dual dispensing
methods and systems that address such deficiencies.
SUMMARY
[0012] An exemplary method is provided for dispensing a first fluid
pattern at a first dispense region and a second fluid pattern at a
second dispense region. The first and second dispense regions may
be first and second independent substrates, as primarily shown and
described herein, or they may be separate regions of a common
substrate, for example. The first and second dispense regions are
positioned relative to a reference plane defined by a first axis
and a second axis orthogonal to the first axis. Positions of the
first and second dispense regions in the reference plane are
determined. Positions of the first dispense region and the second
dispense region along a third axis are determined, the third axis
being mutually orthogonal with the first and second axes. A first
applicator is moved toward the first dispense region with a
positioner and the second applicator is moved toward the second
dispense region with the positioner. The first fluid pattern is
dispensed at the first dispense region with the first applicator
and the second fluid pattern is simultaneously dispensed at the
second dispense region with the second applicator. The second
applicator is moved relative to the first applicator in at least
one of a direction parallel to the first axis, a direction parallel
to the second axis, or a direction parallel to the third axis while
the first applicator dispenses at the first dispense region and the
second applicator simultaneously dispenses at the second dispense
region.
[0013] Another exemplary method is provided for dispensing a first
fluid pattern at a first dispense region and a second fluid pattern
at a second dispense region. The first and second dispense regions
are positioned relative to a reference plane defined by a first
axis and a second axis orthogonal to the first axis. The first
dispense region is provided with at least one of a first tilt or a
first contour relative to the reference plane and along a third
axis mutually orthogonal with the first axis and the second axis.
The at least one of the first tilt or the first contour is unique
to the first dispense region. The method includes determining a
first dispense height path corresponding to the at least one of the
first tilt or the first contour of the first dispense region. The
first dispense height path is unique to the first dispense region.
The method further includes moving the first applicator along the
first dispense height path to dispense the first fluid pattern at
the first dispense region. Simultaneously, the second applicator is
moved relative to the second dispense region to dispense the second
fluid pattern at the second dispense region.
[0014] Another exemplary method is provided for positioning a first
applicator for dispensing fluid at a first dispense region and
positioning a second applicator for dispensing fluid at a second
dispense region. The first dispense region and the second dispense
region are positioned relative to a reference plane defined by a
first axis and a second axis orthogonal to the first axis.
Positions of the first and second dispense regions in the reference
plane are determined. Positions of the first dispense region and
the second dispense region along a third axis are determined, the
third axis being mutually orthogonal with the first and second
axes. A primary positioner is controlled to move the first
applicator and the second applicator in at least one of a direction
parallel to the first axis or a direction parallel to the second
axis to position the first applicator relative to the first
dispense region. Simultaneously, a secondary positioner coupled to
the primary positioner is controlled to move the second applicator
relative to the first applicator in at least one of a direction
parallel to the first axis or a direction parallel to the second
axis to position the second applicator relative to the second
dispense region.
[0015] An exemplary dispensing system is provided for dispensing
fluid at a first dispense region and a second dispense region. The
first and second dispense regions are each positioned relative to a
reference plane defined by a first axis and a second axis
orthogonal to the first axis. The system includes a first
applicator for dispensing fluid at the first dispense region, and a
second applicator for dispensing fluid at the second dispense
region. A primary positioner is configured to position the first
applicator for dispensing fluid at the first dispense region. The
primary positioner supports the first applicator and has a first
drive to move the first applicator in a direction parallel to the
first axis, a second drive to move the first applicator in a
direction parallel to the second axis, and a third drive to move
the first applicator in a direction parallel to a third axis. The
third axis is mutually orthogonal with the first and second axes. A
secondary positioner is coupled to the primary positioner and is
configured to position the second applicator for dispensing fluid
at the second dispense region. The secondary positioner supports
the second applicator and has a first drive to move the second
applicator relative to the first applicator in a direction parallel
to the first axis, a second drive to move the second applicator
relative to the first applicator in a direction parallel to the
second axis, and a third drive to move the second applicator
relative to the first applicator in a direction parallel to the
third axis. The first drives, the second drives, and the third
drives associated with the primary positioner and the secondary
positioner are controlled by a system controller.
[0016] Various additional features and advantages of the invention
will become more 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 THE DRAWINGS
[0017] The accompanying drawings, which are incorporated in and
constitute a part of this specification, illustrate embodiments of
the invention and, together with a general description of the
invention given above, and the detailed description of the
embodiments given below, serve to explain the principles of the
invention.
[0018] FIG. 1 is a top elevational view showing a carrier tray
containing a plurality of substrates each aligned in proper,
centered orientations.
[0019] FIG. 2 is a top elevational view showing a carrier tray
containing a plurality of substrates each rotated or translated
from their centered orientations.
[0020] FIG. 3 is a top elevational view similar to FIG. 2, showing
a substrate tilted relative to a horizontal XY plane.
[0021] FIG. 3A is a side cross-sectional view taken along line
3A-3A of FIG. 3, showing the substrate tilted relative to the
horizontal XY plane.
[0022] FIG. 4 is an isometric schematic view of a dual applicator
dispensing system according to an embodiment of the invention.
[0023] FIG. 5 is an isometric schematic view similar to FIG. 3,
showing a secondary positioner disassembled from a primary
positioner.
[0024] FIG. 6 is a top elevational view of the dispensing system of
FIG. 4, further showing a parts carrier tray in which the
substrates are each rotated or translated from their centered
orientations.
[0025] FIG. 7 is a top elevational view of first and second
substrates of FIG. 6, showing positions of first and second
applicator dispense tips prior to dispensing first and second fluid
patterns.
[0026] FIG. 8 is a top elevational view similar to FIG. 7, showing
positions of the applicator dispense tips after dispensing first
portions of the fluid patterns.
[0027] FIG. 9 is a top elevational view similar to FIG. 7, showing
positions of the applicator dispense tips after dispensing second
portions of the fluid patterns.
[0028] FIG. 10 is a top elevational view similar to FIG. 7, showing
positions of the applicator dispense tips after dispensing third
portions of the fluid patterns.
[0029] FIG. 11 is a top elevational view similar to FIG. 7, showing
positions of the applicator dispense tips after dispensing fourth
portions of the fluid patterns.
[0030] FIG. 12A is an isometric view showing a substrate that is
tilted relative to an XY plane, and a corresponding dispense height
path along which an applicator moves while dispensing onto the
tilted substrate.
[0031] FIG. 12B is an isometric view showing a substrate that is
contoured relative to the XY plane, and a corresponding dispense
height path along which an applicator moves while dispensing onto
the contoured substrate.
[0032] FIG. 13A is side elevational view showing first and second
dispense regions provided on first and second substrates that are
each uniquely tilted and contoured relative to the XY plane, and a
unique dispense height path corresponding to each dispense
region.
[0033] FIG. 13B is a side elevational view showing first and second
dispense regions provided on a single contoured substrate, and a
unique dispense height path corresponding to each dispense
region.
[0034] FIGS. 14A and 14B present a flow diagram illustrating steps
of a method for simultaneously dispensing at first and second
dispense regions.
DETAILED DESCRIPTION
[0035] Turning to FIGS. 4 and 5, an exemplary dual applicator fluid
dispensing system 30 for dispensing viscous fluids at a plurality
of dispense regions, such as independent substrates A, B, C, D held
in a carrier tray 32, is shown schematically. While only four
substrates A-D are shown herein, arranged in a rectangular
configuration in corresponding pockets 33a, 33b, 33c, 33d, the
carrier tray 32 may be adapted to carry any desired number of
substrates arranged in any desired configuration. Alternatively,
the multiple dispense regions may be distinct regions of a single
substrate, as discussed above. In this regard, while dispense
regions are primarily exemplified herein as multiple independent
substrates, it will be appreciated that, alternatively, dispense
regions may be part of single common substrate, for example as
shown in FIG. 13B. In one embodiment, the dispense regions may be
part of a panelized substrate, such as a panelized circuit board
(not shown).
[0036] The carrier tray 32 may be positioned on a conveyor belt
(not shown), which may be operated to deliver the carrier tray 32
to a position generally beneath the dispensing system 30 such that
the substrates A-D carried therein may be dispensed upon by the
dispensing system 30. Alternatively, the carrier tray 32 may be
positioned on any other suitable platform, such as a stationary
table or pedestal, located generally within an operating perimeter
of the dispensing system 30. The dual dispensing system 30 includes
a first fluid applicator 34 mounted to a primary positioner 36 and
a second fluid applicator 38 mounted to a secondary positioner 40.
The secondary positioner 40 is coupled to and movable by the
primary positioner 36. The positioners 36, 40 collectively define a
gantry 42 for positioning the first applicator 34 for dispensing at
a first dispense region and the second applicator 38 for
simultaneously dispensing at a second dispense region, as described
in greater detail below.
[0037] The dual dispensing system 30 defines a global origin O and
three mutually orthogonal global axes X, Y, and Z. The primary
positioner 36 is movable in directions parallel to the global X, Y,
and Z axes, denoted generally by x.sub.1, y.sub.1, and z.sub.1,
respectively, and corresponding directional arrows. Similarly, the
secondary positioner 40 is also movable in directions parallel to
the global X, Y, and Z axes, denoted generally by x.sub.2, y.sub.2,
and z.sub.2, respectively, and corresponding directional
arrows.
[0038] The primary positioner 36 includes a pair of opposed x.sub.1
supports 44a and 44b aligned parallel with the X axis and shown
generally as longitudinal beams. The x.sub.1 supports 44a, 44b are
each provided with an x.sub.1 bearing 46a and 46b, respectively,
shown as linear bearings, for enabling x.sub.1 linear movement of
the applicators 34, 38 parallel to the X axis. The primary
positioner 36 further includes a transversely oriented y.sub.1
support 48 aligned parallel with the Y axis and shown generally as
a lateral beam. The y.sub.1 support 48 is provided with a pair of
y.sub.1 bearings 50a and 50b, shown as linear bearings, for
enabling y.sub.1 linear movement of the applicators 34, 38 parallel
to the Y axis. The y.sub.1 support 48 is movably coupled to the
x.sub.1 supports 44a, 44b through a pair of opposed legs 52a and
52b, which engage and are slidable along the x.sub.1 bearings 46a,
46b, respectively, for x.sub.1 movement. The primary positioner 36
further includes a y.sub.1 carriage 54 having a lower XY surface
that engages and is slidable along the y.sub.1 bearings 50a, 50b
for y.sub.1 movement. The y.sub.1 carriage 54 has a YZ surface
(i.e., a surface lying in the YZ plane) to which is attached a
vertically oriented z.sub.1 support 56, aligned parallel with the Z
axis and shown generally in the form of a plate. The z.sub.1
support 56 includes a pair of vertically oriented z.sub.1 bearings
58a and 58b, shown as linear bearings, for enabling z.sub.1 linear
movement of the applicators 34, 38 in a direction parallel to the Z
axis. As shown, the z.sub.1 bearings 58a, 58b may be provided on
adjacent XZ and YZ surfaces, respectively, of the z.sub.1 support
56. A z.sub.1 carriage 60, shown in the form of an L-shaped
bracket, has a first leg 62a and a second leg 62b that engage and
are slidable along the z.sub.1 bearings 58a, 58b, respectively, for
z.sub.1 movement. A first applicator mounting mechanism 64 may be
coupled to the second leg 62b and may be configured to releasably
support the first applicator 34, as described in greater detail
below.
[0039] The secondary positioner 40 is coupled to the primary
positioner 36 and enables x.sub.2, y.sub.2, and z.sub.2 movements
of the second applicator 38 relative to the primary positioner 36
and the first applicator 34 mounted thereon. The secondary
positioner 40 includes a y.sub.2 support 70 which may act as a base
plate and may be rigidly coupled at a YZ surface to the first leg
62a of the z.sub.1 carriage 60 of the primary positioner 36. The
y.sub.2 support 70 may include a pair of y.sub.2 bearings 72a and
72b, shown as linear bearings, which may be positioned adjacent to
each other on an opposed YZ surface of the y.sub.2 support 70. The
y.sub.2 bearings 72a, 72b are aligned parallel with the Y axis to
enable y.sub.2 movement of the second applicator 38 relative to the
primary positioner 36. The secondary positioner 40 further includes
a z.sub.2 support 74, shown generally as a plate. A YZ surface of
the z.sub.2 support 74 may engage and be slidable along the y.sub.2
bearings 72a, 72b for y.sub.2 movement. An opposed YZ surface of
the z.sub.2 support 74 may include a pair of z.sub.2 bearings 76a
and 76b, shown as linear bearings, which are aligned parallel with
the Z axis to enable z.sub.2 movement of the second applicator 38
relative to the primary positioner 36.
[0040] A z.sub.2 carriage 78, shown generally in the form of a
plate, may include a YZ surface that engages and is slidable along
the z.sub.2 bearings 76a, 76b for z.sub.2 movement. An x.sub.2
support 80 may be rigidly coupled to an XZ surface of the z.sub.2
carriage 78, in a perpendicular orientation. Alternatively, the
x.sub.2 support 80 and the z.sub.2 carriage 78 may be formed
integrally. The x.sub.2 support 80 may include an x.sub.2 bearing
82, shown as a linear bearing, that is aligned parallel with the X
axis to enable x.sub.2 movement of the second applicator 38
relative to the primary positioner 36. A second applicator mounting
mechanism 84 may engage and be slidable along the x.sub.2 bearing
82 for x.sub.2 movement, and may be configured to releasably
support the second applicator 38, as described in greater detail
below.
[0041] The first and second applicator mounting mechanisms 64, 84
may be configured to receive and releasably engage the first and
second applicators 34, 38, respectively. For example, the
applicator mounting mechanisms 64, 84 may each include a
quick-disconnect feature (not shown) that enables proper alignment
with the corresponding applicator 34, 38 through one or more
projections and mating recesses. U.S. Pat. No. 6,214,117 and EP
Patent No. 1 165 250 B1, the disclosures of which are hereby
incorporated by reference herein, show prior art examples of quick
disconnect mechanisms for mounting applicators to mechanisms for
moving the applicators.
[0042] The first and second applicators 34, 38 may be of any
preferred type suitable for a user's intended application, such as
an air-operated needle valve or jet of the types made available by
Nordson ASYMTEK of Carlsbad, Calif., for example. As shown best in
FIGS. 4 and 5, each applicator 34, 38 may be in the form of a
pneumatically operated jetting valve such as a model DJ 9000 valve
available from Nordson ASYMTEK. As shown, each applicator 34, 38
may include a corresponding fluid reservoir 86, 88 for storing
viscous fluid, an actuator 90, 92, for jetting, or dispensing,
viscous fluid from a dispensing tip 94, 96 for application to a
substrate A-D positioned beneath the dispensing tip 94, 96. An
example of a suitable dispenser is shown in U.S. Pat. No.
8,578,729, the disclosure of which is hereby incorporated by
reference herein. As discussed above, the viscous fluid may be any
solder paste, underfill material, adhesive, or encapsulant, for
example.
[0043] Movement of the primary and secondary positioners 36, 40 may
be preferably accomplished through a series of controllable,
powered drive mechanisms. More specifically, each direction of
movement x.sub.1, y.sub.1, z.sub.1, x.sub.2, y.sub.2, and z.sub.2
may be powered by at least one corresponding powered drive
mechanism. As shown, a pair of x.sub.1 drive mechanisms 100a and
100b may operate in parallel to power x.sub.1 movement along the
x.sub.1 bearings 46a, 46b, respectively, and may be provided
internally within or adjacent to the legs 52a, 52b, respectively.
Alternatively, x.sub.1 movement may be powered by a single drive
mechanism (not shown). A y.sub.1 drive mechanism 102 may power
y.sub.1 movement along the y.sub.1 bearings 50a, 50b and may be
provided internally within or adjacent to the y.sub.1 carriage 54,
as shown. A z.sub.1 drive mechanism 104 may power z.sub.1 movement
along the z.sub.1 bearings 58a, 58b and may be provided adjacent to
an external XZ surface of the z.sub.1 support 56, as shown. A
y.sub.2 drive mechanism 106 may power y.sub.2 movement along the
y.sub.2 bearings 72a, 72b and may be provided adjacent to an
external XZ surface of the y.sub.2 support 70, as shown. A z.sub.2
drive mechanism 107 may power z.sub.2 movement along the z.sub.2
bearings 76a, 76b and may be provided adjacent to an external upper
XY surface of the z.sub.2 carriage 78, as shown. An x.sub.2 drive
mechanism 108 may power x.sub.2 movement along the x.sub.2 bearing
82 and may be provided adjacent to an external YZ surface of the
second applicator mounting mechanism 84, as shown.
[0044] In one embodiment, the drive mechanisms 100a, 100b, 102,
104, 106, 107, 108 may include stepper motors. Alternatively, the
drive mechanisms 100a, 100b, 102, 104, 106, 107, 108 may include
any other suitable electric, pneumatic, or hydraulic drive adapted
to movement with a high degree of accuracy, repeatability, and
stability. Additionally, the drive mechanisms 100a, 100b, 102, 104,
106, 107, 108 may include any additional mechanical drive elements
suitable for moving the positioners 36, 40. For example, in one
embodiment (not shown) the drive mechanisms 100a, 100b, 102, 104,
106, 107, 108 may include stepper motors each having an output
shaft connected with a flexible drive coupling to a lead screw. The
lead screw may rotate with the motor and engages a threaded or
toothed element mounted on a corresponding support to actuate
movement along a corresponding linear bearing. The drive mechanisms
100a, 100b, 102, 104, 106, 107, 108 may be mounted at any suitable
locations within the dispensing system 30 different from those
shown and described herein.
[0045] As presented above, the secondary positioner 40 is coupled
to the primary positioner 36 and thus the x.sub.1, y.sub.1, and
z.sub.1 movements of the primary positioner 36 are transferrable to
the secondary positioner 40 and the second applicator 38 mounted
thereon. The secondary positioner 40 enables additional movements
x.sub.2, y.sub.2, and z.sub.2 relative to the primary positioner
36, which movements may be relatively fine in comparison to the
corresponding x.sub.1, y.sub.1, and z.sub.1 movements performed by
the primary positioner 36. Accordingly, in one embodiment, the
secondary positioner 40 is movable with ranges of motion that are
less than corresponding ranges of motion of the primary positioner
36. More specifically, the primary positioner may have a range of
motion in each of the directions parallel to the X axis, the Y
axis, and the Z axis (i.e., x.sub.1, y.sub.1, and z.sub.1
movements). Similarly, the secondary positioner 40 may have a range
of motion in each of the directions parallel to the X axis, the Y
axis, and the Z axis (i.e., x.sub.2, y.sub.2, and z.sub.2
movements). The ranges of motion of the secondary positioner 40 may
be smaller than the corresponding ranges of motion of the primary
positioner 36. In this manner, the primary positioner 36 may
perform a primary movement to move the first applicator 34 and the
second applicator 38, the primary movement defined by any one or
combination of x.sub.1, y.sub.1, and z.sub.1 movements and having a
magnitude. Simultaneously, the secondary positioner 40 may perform
a secondary movement relative to the primary positioner 36 to move
the second applicator 38 relative to the first applicator 34, the
secondary movement defined by any one or combination of x.sub.2,
y.sub.2, and z.sub.2 movements and having a magnitude that is less
than the magnitude of the primary movement.
[0046] Accordingly, the first applicator 34 may be positioned with
the primary positioner 36, and the second applicator 38 may be
jointly positioned by the primary positioner 36 and the secondary
positioner 40. More specifically, the first applicator 34 and the
second applicator 38 are both positionable with y.sub.1, and
z.sub.1 movements. The second applicator 38 is additionally
positionable with x.sub.2, y.sub.2, and z.sub.2 movements made
relative to the primary positioner 36. Thus, the structural
configuration of the dispensing system 30 enables the second
applicator 38 to be moved relative to the first applicator 34 in
directions parallel to the X, Y, and Z axes. Thereby, the first and
second applicators 34, 38 may simultaneously dispense first and
second fluid patterns onto first and second substrates,
respectively, where the fluid patterns are substantially identical
in size and shape and where the substrates are misaligned relative
to each other. As described above, the fluid patterns may include
one or more lines, arcs, dots, combinations thereof, and/or any
other configuration of continuously or intermittently dispensed
fluid.
[0047] The primary positioner 36 and the secondary positioner 40
are independently controllable with at least one controller (not
shown), such as a computer. Preferably, the controller is
configured to instruct the x.sub.1, y.sub.1, and z.sub.1 movements
of the primary positioner 36, and to simultaneously instruct the
x.sub.2, y.sub.2, and z.sub.2 movements of the secondary positioner
40 by controlling the drive mechanisms 100a, 100b, 102, 104, 106,
107, 108. In this manner, the primary positioner 36 is controllable
such that the first applicator 34 may be properly positioned
relative to and dispense at a first dispense region, such as
substrate A. Simultaneously, the secondary positioner 40 is
independently controllable such that the second applicator 38 may
be properly positioned relative to and dispense at a second
dispense region, such as substrate B. As discussed in greater
detail below, the positioners 36, 40 are controllable to account
for misalignment between a first dispense region and a second
dispense region, such as substrates A and B, for example.
[0048] Having just described a dispensing system that is novel in
structure, methods of simultaneously dispensing at first and second
dispense regions will now be described. The methods are described
herein with reference to substrates A, B, C, D shown in FIGS. 6-11.
As discussed above, persons skilled in the art will appreciate that
the dispensing methods described herein may be adapted for
simultaneously dispensing at any two dispense regions of a
plurality of dispense regions with the dispensing system 30. For
example, first and second dispense regions may be part of a single
substrate, such as a panelized substrate.
[0049] The dispensing system 30 may first identify the location and
orientation of each substrate A, B, C, D in the XY plane relative
to a global origin O, based on the positions of at least two
reference fiducials 110a, 110b provided on each substrate A-D. For
example, with reference to substrate A, the two fiducials 110a,
110b may be provided at opposing corners of an upper XY surface of
the substrate A. While shown herein as an "x" enclosed by a circle,
the fiducials 110a, 110b may be any identifiable mark such as a
letter, number, dot, or pattern, for example. In this manner, the
dispensing system 30 may determine whether each substrate is
rotated and/or translated in the XY plane relative to a
corresponding reference position defined with respect to origin
O.
[0050] The dual dispensing system 30 includes a camera 112 for
identifying the reference fiducials 110a, 110b. The camera 112 may
be mounted to the gantry 42 at any suitable location, such as a
portion of the secondary positioner 40, as shown in FIG. 6. For
fiducial identification, the gantry 42 may be controlled to move
the camera 112 along a pre-programmed path based on expected
locations of the fiducials 110a, 110b in the XY plane. In one mode,
the gantry 42 may be controlled to sequentially pause at the
expected location of each fiducial 110a, 110b so that the camera
112 may capture a visual image of a fiducial 110a, 110b during each
pause. In another mode, the gantry 42 may be controlled to
continuously move and the camera 112 may capture visual images of
the fiducials 110a, 110b during movement. Based on the images of
the fiducials 110a, 110b captured by the camera 112, the controller
may then determine the actual position of each substrate A, B, C, D
in the XY plane.
[0051] The dual dispensing system 30 further includes a height
sensor 114 for performing height sensing operations, which includes
measuring the position of each substrate A-D along the Z axis,
relative to the XY plane. The height sensor 114 may be a
non-contact laser sensor, or alternatively may be a contact
mechanical sensor. In operation, the gantry 42 may be controlled to
move the height sensor 114 along a pre-programmed path for
measuring the position each substrate A-D along the Z axis. These
measurements, referred to herein as Z height measurements, enable
the controller to determine for each substrate A-D a proper height
along the Z axis, referred to as a dispense height, to which the
dispensing tip 94, 96 of the first or second applicator 34, 38
should be lowered for dispensing fluid onto the substrate A-D. In
this manner, the system 30 may ensure a proper dispense gap between
the dispensing tips 94, 96 and the corresponding substrates A-D
while dispensing.
[0052] As shown in FIG. 6, the substrates A-D may lie generally
parallel to the XY plane, and thus a single height measurement for
each substrate A-D may be sufficient. Alternatively, one or more of
the substrates A-D may be tilted relative to the XY plane (see,
e.g., FIGS. 3A, 12A) such that the substrate is positioned at
various points along the Z axis. In such case, the height sensor
114 may be operated to measure multiple heights of the tilted
substrate and thereby map the tilt along the Z axis. Similarly,
multiple Z height measurements may also be collected for a
substrate having a surface, onto which fluid is to be dispensed,
that is contoured relative to the XY plane and along the Z axis
(referred to herein as a "contoured substrate," and similar
variations thereof), as shown in FIGS. 12B-13B. As described in
greater detail below, the multiple Z height measurements collected
for a tilted and/or contoured substrate may then be used by the
controller to determine z.sub.1 or z.sub.2 movements that the
primary positioner 36 or the secondary positioner 40 must actively
perform during dispensing in order to accommodate the tilted
orientation of the substrate or its contoured surface. The camera
112 and height sensor 114 may be integrated into a single system
operable by the controller for collecting fiducial information and
height measurements for each of the substrates A-D to be dispensed
upon.
[0053] Based on the information gathered by the controller during
the fiducial locating and height sensing operations described
above, the primary and secondary positioners 36, 40 may be operated
to simultaneously position the first applicator 34 relative to a
first substrate and the second applicator 38 relative to a second
substrate. The first applicator 34 may then dispense a first fluid
pattern onto the first substrate while the second applicator 38
simultaneously dispenses a second, identical fluid pattern onto the
second substrate. The positioners 36, 40 are automatically movable
while dispensing to actively correct for any positional
misalignment of one of the substrates relative to the other. These
positioning and dispensing steps may be performed with respect to
any two of the substrates A-D, for example, which are each rotated
and/or translated along the X and Y axes relative to each of the
other substrates A-D, as shown in FIGS. 6-11.
[0054] FIGS. 7-11 show a series of steps in which the first
applicator 34 is positioned relative to substrate A and dispenses a
fluid pattern 116 thereon. Simultaneously, the second applicator 38
is positioned relative to substrate B and dispenses a substantially
identical fluid pattern 118 thereon. Substrates A and B are shown
each misaligned from their respective centered positions within
their respective pockets 33a, 33b (see, e.g., FIG. 2). The
geometric centers of the pockets 33a, 33b in the XY plane are
represented by crosshairs. As shown, substrate A is rotated from
its centered position relative to the X and Y axes, while substrate
B is translated from its centered position along the X and Y axes.
Accordingly, substrates A and B are rotated and translated relative
to each other with respect to the X and Y axes. As described below,
the second applicator 38 is movable in the XY plane relative to the
first applicator 34 while dispensing to thereby actively and
automatically correct for misalignments of the substrates A, B in
the XY plane.
[0055] As shown, the first and second applicator dispensing tips
94, 96 are each represented in FIGS. 7-11 by a pair of concentric
phantom circles. The shapes of the fluid patterns 116, 118 to be
dispensed are represented by directional arrows forming generally
rectangular outlines about the perimeters of components 120a, 120b
provided on the substrates A, B. Accordingly, FIGS. 7-11 simulate
dispensing of an adhesive underfill material which is dispensed
along the edge of a component, such as a flip chip having a grid of
solder balls on its underside which are positioned on corresponding
matching contact pads on the substrate, with the underfill material
flowing under the chip and around the solder balls to secure the
flip chip to the substrate. Persons of ordinary skill in the art
will appreciate that the positioners 36, 40 and the applicators 34,
38 mounted thereon may be controlled to dispense fluid patterns of
any other desired shape and at any other desired region of one or
more substrates or other similar workpieces. For example, as
discussed above, the fluid patterns may include one or more lines,
arcs, dots, combinations thereof, and/or any other configuration of
continuously or intermittently dispensed fluid.
[0056] Referring to FIG. 7, the controller may command the primary
positioner 36 to execute x.sub.1 and y.sub.1 movements to thereby
position the first applicator dispensing tip 94 to overlie a first
dispense site 122 on substrate A. Simultaneously, the controller
may command the secondary positioner 40 to execute x.sub.2 and
y.sub.2 movements relative to the primary positioner 36 to thereby
position the second applicator dispensing tip 96 over a
corresponding first dispense site 124 on substrate B. The
controller may then command the primary positioner 36 to execute
downward z.sub.1 movement to thereby advance the first and second
dispensing tips 94, 96 simultaneously toward their proper dispense
heights, as determined during the height sensing operation
described above. If the controller determines, through the height
sensing operation, that substrates A and B are each positioned at
the same location along the Z axis, the first and second dispensing
tips 94, 96 may be positioned at the same dispense height through
z.sub.1 movement of the primary positioner 36. If the controller
determines, through the height sensing operation, that substrates A
and B are positioned at different locations along the Z axis, the
controller may additionally command the secondary positioner 40 to
execute z.sub.2 movement relative to and simultaneously with the
z.sub.1 movement of the primary positioner 36. Thereby, the first
and second dispensing tips 94, 96 may be simultaneously positioned
at their proper, respective dispensing heights. The dispensing
system 30 may now dispense onto substrates A and B.
[0057] As shown in FIG. 8, the first applicator 34 and its
dispensing tip 94 may be moved by the primary positioner 36 to
dispense a first leg 116a of fluid pattern 116. Simultaneously, the
second applicator 38 and its dispensing tip 96 may be moved by the
secondary positioner 40 relative to the primary positioner 36 and
the first applicator 34 to dispense a first leg 118a of fluid
pattern 118. More specifically, the controller may command the
primary positioner 36 to execute x.sub.1 and y.sub.1 movements, and
further command the secondary positioner 40 to simultaneously
execute corrective x.sub.2 and y.sub.2 movements relative to the
primary positioner 36. The controller may issue such commands based
on the known locations and orientations of the substrates A, B in
the XY plane as determined by the controller during the fiducial
identification process described above. In this manner, the
dispensing system 30 may automatically and actively adjust
positioning of the first and second applicators 34, 38 while
dispensing to correct for local rotation of substrates A and B.
[0058] As shown in FIG. 9, the first applicator 34 and its
dispensing tip 94 may be moved by the primary positioner 36 to
dispense a second leg 116b of fluid pattern 116. Simultaneously,
the second applicator 38 and its dispensing tip 96 may be moved by
the secondary positioner 40 relative to the primary positioner 36
and the first applicator 34 to dispense a second leg 118b of fluid
pattern 118. More specifically, the controller may command the
primary positioner 36 to execute x.sub.1 and y.sub.1 movements, and
further command the secondary positioner 40 to simultaneously
execute corrective x.sub.2 and y.sub.2 movements relative to the
primary positioner 36 while dispensing to correct for the local
rotation of substrates A and B.
[0059] As shown in FIG. 10, the first applicator 34 and its
dispensing tip 94 may be moved by the primary positioner 36 to
dispense a third leg 116c of fluid pattern 116. Simultaneously, the
second applicator 38 and its dispensing tip 96 may be moved by the
secondary positioner 40 relative to the primary positioner 36 and
the first applicator 34 to dispense a third leg 118c of fluid
pattern 118. More specifically, and as similarly performed when
dispensing the first legs 116a, 118a, the controller may command
the primary positioner 36 to execute x.sub.1 and y.sub.1 movements,
and simultaneously the controller may command the secondary
positioner 40 to execute corrective x.sub.2 and y.sub.2 movements
relative to the primary positioner 36 to correct for the local
rotation of substrates A and B.
[0060] As shown in FIG. 11, the first applicator 34 and its
dispensing tip 94 may be moved by the primary positioner 36 to
dispense a fourth leg 116d of fluid pattern 116. Simultaneously,
the second applicator 38 and its dispensing tip 96 may be moved by
the secondary positioner 40 relative to the primary positioner 36
and the first applicator 34 to dispense a fourth leg 118d of fluid
pattern 118, thereby completing the fluid patterns 116, 118. More
specifically, and as similarly performed when dispensing the second
legs 116b, 118b, the controller may command the primary positioner
36 to execute x.sub.1 and y.sub.1 movements, and simultaneously the
controller may command the secondary positioner 40 to execute
corrective x.sub.2 and y.sub.2 movements relative to the primary
positioner 36 to correct for the local rotation of substrates A and
B.
[0061] One or both of the substrates A, B may be tilted relative to
the XY plane, as demonstrated by substrate 130 in FIG. 12A. As
described above, the height sensor 114 may be operated to collect
multiple height measurements of a tilted substrate along the Z
axis, and these measurements may then be conveyed to the
controller. As shown in FIG. 12A, the controller may then determine
a dispense height path P that varies in height along the Z axis and
along which a corresponding dispensing tip 94, 96 may be moved in
order to maintain a constant and accurate dispense gap G between
the tip 94, 96 and the tilted substrate 130. Thus, if the substrate
B of FIGS. 7-11, and its corresponding component 120b, had a tilt
like that shown for substrate 130, in addition to making the
x.sub.2 and y.sub.2 corrections as described above, the secondary
positioner 40 would make corrective z.sub.2 movements relative to
the primary positioner 36, while dispensing, to correct for the
tilt of substrate B with respect to substrate A. In this manner,
the system 30 may accurately dispense a fluid pattern, such as
pattern 118, onto the tilted substrate. Consequently, as shown in
FIG. 12A, corrective z.sub.2 movements would be made along the Z
axis such that the dispensing tip 96 travels in a plane
substantially parallel to the tilted substrate.
[0062] A similar process may be performed where one or both of the
substrates A, B is contoured relative to the XY plane, along the Z
axis, as demonstrated by substrate 132 in FIG. 12B, which could be
a warped substrate, for example. In particular, the system may
collect multiple Z height measurements corresponding to a contoured
substrate. As shown in FIG. 12B, the system 30 may then determine a
corresponding dispense height path P that varies in height along
the Z axis and along which a corresponding dispensing tip 94, 96
may be moved in order to maintain a constant and accurate dispense
gap G between the tip 94, 96 and the contoured substrate 132. The
process described above with respect to the tilted substrate shown
in FIG. 12A may also be applied to contoured substrates. For
example, if the substrate B shown in FIGS. 7-11 had a contour like
that shown for substrate 132, in addition to making the x.sub.2 and
y.sub.2 corrections as described above, the secondary positioner 40
would also make corrective z.sub.2 movements relative to the
primary positioner 36, while dispensing, to correct for the contour
of substrate B with respect to substrate A. In this manner, the
system 30 may accurately dispense a fluid pattern, such as fluid
pattern 118, onto the contoured substrate. Consequently, as shown
in FIG. 12B, corrective z.sub.2 movements would be made along the Z
axis such that the dispensing tip 96 travels along a path that
substantially conforms to the contoured substrate.
[0063] As demonstrated by substrates 134 and 136 in FIG. 13A, two
substrates being dispensed upon, for example substrates A and B,
may each be uniquely tilted and contoured relative to the XY plane
and relative to each other, and corresponding dispense height paths
P1 and P2 may be determined by the system 30 based on the detected
Z height measurements. In another embodiment, instead of using a
height sensor, electronic data defining the tilt and/or contour of
a substrate may be entered into the system 30 by a user. Such
electronic data may then be used to determine a dispense height
path.
[0064] In another embodiment (not shown), first and second
substrates may be arranged such that they are not rotated relative
to each other in the XY plane, and each substrate is provided with
the same tilt and/or contour relative to the XY plane such that the
substrates are not uniquely tilted or contoured relative to each
other. In such case, the dispense height paths determined by the
system 30 for the substrates may be substantially identical, and
the secondary positioner 40 need not make corrective movements
relative to the primary positioner 36 during dispense. In other
words, the first and second applicators may remain stationary
relative to each other while moving together along X, Y, and Z to
simultaneously dispense on the first and second substrates.
[0065] With reference to substrates A and B of FIGS. 6-11, a first
scenario, also described above, may arise in which substrate A is
generally planar and lies parallel to the XY plane, and substrate B
is tilted relative to the XY plane and/or includes a contoured
surface, as demonstrated by substrates 130 and 132 of FIGS. 12A and
12B. In such case, the controller may determine a dispense height
path for tilted and/or contoured substrate B based on height
measurements collected during the height sensing operation
discussed above. Then, while the first applicator 34 is moved in
the XY plane to dispense onto substrate A and the second applicator
38 is simultaneously moved in the XY plane to dispense onto
substrate B, the controller may command the secondary positioner 40
to simultaneously execute z.sub.2 movements relative to the primary
positioner 36. Thereby, the second dispensing tip 96 is movable
along the pre-determined dispense height path while the second
applicator 38 dispenses onto tilted and/or contoured substrate B.
In this manner, the dispensing system 30 may automatically and
actively adjust the positioning of the second applicator 38 along
the Z axis to correct for tilt and/or contour of substrate B
relative to the XY plane.
[0066] In a second scenario, substrate A may be tilted and/or
contoured relative to the XY plane, as demonstrated by substrates
130 and 132 of FIGS. 12A and 12B, while substrate B is generally
planar and lies parallel to the XY plane. In such case, the
controller may determine a dispense height path for tilted and/or
contoured substrate A in a manner as described above. Then, while
the first applicator 34 is moved in the XY plane to dispense onto
tilted and/or contoured substrate A, the controller may command the
primary positioner 36 to simultaneously execute z.sub.1 movements.
Thereby, the first dispensing tip 94 is movable along the
pre-determined dispense height path while the first applicator 34
dispenses onto tilted and/or contoured substrate A. Simultaneously,
the second applicator 38 is moved in the XY plane to dispense onto
substrate B, and the controller may command the secondary
positioner 40 to execute z.sub.2 movements relative to the primary
positioner 36, the z.sub.2 movements being substantially opposite
of the z.sub.1 movements made by the primary positioner 36.
Thereby, the second dispensing tip 96 may be maintained at a
constant, pre-determined dispense height corresponding to substrate
B while the second applicator 38 dispenses onto part B.
[0067] In a third scenario, both substrates A and B may be tilted
and/or contoured relative to the XY plane. By way of example with
reference to FIG. 13A, substrate A may correspond to substrate 134
and substrate B may correspond to substrate 136. In this regard,
substrate A may be provided with a first tilt and/or a first
contour that is unique to substrate A, and substrate B may be
provided with a second tilt and/or a second contour that is unique
to substrate B. The controller may determine a first dispense
height path P1 corresponding to tilted and/or contoured substrate A
and a second dispense height path P2 corresponding to tilted and/or
contoured substrate B, in a manner as described above. Then, while
the first applicator 34 is moved in the XY plane to dispense onto
substrate A, the controller may command the primary positioner 36
to simultaneously execute z.sub.1 movements. Thereby, the first
dispensing tip 94 is movable along the first dispense height path
P1 to maintain a first dispense gap G1, while the first applicator
34 dispenses onto substrate A. Simultaneously, while the second
applicator 38 is moved in the XY plane to dispense onto tilted
and/or contoured substrate B, the controller may command the
secondary positioner 40 to execute z.sub.2 movements relative to
the primary positioner 36 to correct both for the z.sub.1 movements
executed by the primary positioner 36 and the unique tilt and/or
contour of substrate B. Thereby, the second dispensing tip 96 is
movable along the second dispense height path P2 to maintain a
second dispense gap G2, while the second applicator 38 dispenses
onto substrate B. In this manner, the first applicator 34 may
accurately dispense onto a uniquely tilted and/or contoured first
substrate and simultaneously the second applicator 38 may
accurately dispense onto a uniquely tilted and/or contoured second
substrate.
[0068] In an alternative embodiment similar to the third scenario
described above, the first and second applicators 34, 38 may
simultaneously dispense first and second fluid patterns at first
and second dispense regions, respectively, that are each distinct
regions of a single common substrate. For example, as shown in FIG.
13B, the primary positioner 36 may execute z.sub.1 movements to
move the first applicator 34 along a first dispense height path P1
at a first uniquely contoured dispense region of substrate 138.
Thereby, a first dispense gap G1 associated with the first dispense
region may be maintained while dispensing. Simultaneously, the
secondary positioner 40 may execute z.sub.2 movements to move the
second applicator 38 along a second dispense height path P2 at a
second uniquely contoured dispense region of the substrate 138.
Thereby, a second dispense gap G2 associated with the second
dispense region may be maintained while dispensing. In various
embodiments, the first and second dispense gaps G1, G2 may be the
same or they may be different.
[0069] In a fourth scenario, substrates A and B may both be
generally planar and lie parallel to the XY plane but positioned at
different distances along the Z axis relative to the XY plane. For
example, substrate A may lie in the XY plane, while substrate B is
spaced above the XY plane. In such case, neither substrate A nor B
is tilted or contoured relative to the XY plane, and thus active
correction along the Z axis during dispense is not required by
either applicator 34, 38. The controller may determine an
appropriate dispense height for each substrate A, B in the manner
described above. Prior to dispensing, the controller may command
the primary positioner 36 to execute z.sub.1 movement to lower the
first dispensing tip 94 to its corresponding dispense height along
the Z axis above substrate A. Simultaneously, the controller may
command the secondary positioner 40 to execute z.sub.2 movement
relative to the primary positioner 36 to lower the second
dispensing tip 96 to its corresponding dispense height along the Z
axis above substrate B. The controller may then command the primary
positioner 36 to move the first and second applicators 34, 38
together in the XY plane so that they may simultaneously dispense
first and second fluid patterns onto substrates A and B,
respectively, while maintaining the corresponding dispense heights
for the applicators 34, 38.
[0070] In view of the disclosure above, persons of ordinary skill
in the art will appreciate that the dispensing system 30 is capable
of executing x.sub.1, y.sub.1, and z.sub.1 movements with the
primary positioner 36 and simultaneously executing x.sub.2,
y.sub.2, and z.sub.2 movements with the secondary positioner 40.
Moreover, these movements are executable while the first applicator
34 dispenses at a first dispense region, such as a first substrate,
and the second applicator 38 simultaneously dispenses at a second
dispense region, such as a second substrate. In this manner, the
dispensing system 30 is controllable to automatically and actively
adjust positioning of the first and second applicators 34, 38 while
dispensing to correct for misalignment of first and second
substrates being dispensed upon.
[0071] FIGS. 14A and 14B present a flow diagram illustrating steps
of a method 200 according to one embodiment of the invention for
simultaneously dispensing at first and second dispense regions in a
manner consistent with the disclosure above. The method 200 may be
performed with dispensing system 30 or any suitable variation
thereof, for example. The referenced dispense regions are denoted
"DR." As described above, the first and second dispense regions may
be first and second substrates, or they may be distinct first and
second regions of a single substrate, such as a panelized circuit
board. The referenced first and second applicators are denoted "A1"
and "A2," and may be mounted to and movable by primary and
secondary positioners, respectively, such as positioners 36 and 40
of dispensing system 30 disclosed above.
[0072] At step 202, the dispensing system first identifies
reference fiducials associated with each of the plurality of
dispense regions, for example in the manner described above. In one
embodiment, each dispense region may be provided with its own set
of corresponding reference fiducials. In another embodiment,
multiple dispense regions may be associated with a single set of
reference fiducials, for example where the dispense regions are
regions of a single substrate. At step 204, the system then
determines the location and orientation (i.e., the position) of
each dispense location in the XY plane defined by the system, based
on the identified reference fiducials. At step 206, the system then
collects Z height measurements for the dispense regions through
height sensing. As described above, such height sensing may include
collecting multiple height measurements for dispense regions that
are tilted and/or contoured relative to the XY plane. For example,
such height sensing may include collecting multiple height
measurements of a path along which fluid is to be dispensed, the
path encompassed by a dispense region. Alternatively, as described
above, the system may consult surface contour data entered by a
user for providing the Z heights.
[0073] At step 208, the system may select first and second dispense
regions from the plurality of dispense regions, and assign a first
applicator A1 for dispensing a first fluid pattern at the first
dispense region and a second applicator A2 for dispensing a second
fluid pattern at the second dispense region. At step 210, the
system then assesses, for each of the selected first and second
dispense regions, whether the dispense region is tilted and/or
contoured relative to the XY plane, along the Z axis. If the
dispense region is not tilted or contoured, the system may proceed
to step 212 and determine a proper dispense height for the
applicator assigned to the dispense region, based on a single Z
height previously measured for the dispense region, as described
above. Alternatively, at step 214, where the dispense region is
tilted and/or contoured relative to the XY plane, the system may
determine a corresponding dispense height path based on multiple Z
heights that were previously measured for the dispense region or
otherwise provided by external data entered by a user, as described
above. For example, where each dispense region is uniquely tilted
and/or contoured (see FIGS. 13A and 13B), the system may determine
a unique dispense height path corresponding to each dispense
region. At step 216, the system may then adjust, as appropriate,
the control algorithms associated with an applicator assigned to a
tilted and/or contoured dispense region to account for tilt and/or
contour of the surface that will be dispensed upon. For example,
the control algorithms of an applicator assigned to a tilted and/or
contoured dispense region may be adjusted so that the applicator
selectively dispenses fluid from a proper height or heights
dependent on the dispense height path while moving in directions
having X and Y components of movement, to dispense a fluid
pattern.
[0074] At steps 218a and 218b, the system positions the first
applicator in the XY plane above a first dispense site at the first
dispense region. Simultaneously, the system may move the second
applicator relative to the first applicator in the XY plane to
position the second applicator above a first dispense site at the
second dispense region. At step 220, the system then simultaneously
lowers the first and second applicators along the Z axis to their
respective dispense heights, as determined above in steps 210-214.
If a dispense region is tilted and/or contoured, its applicator may
be lowered to an initial dispense height positioned within the
dispense height path. At step 222, the first and second applicators
are controlled to start dispensing fluid at the respective dispense
regions positioned below.
[0075] Starting at step 224, the first and second applicators are
moved along the X, Y, and/or Z axes to dispense the first and
second fluid patterns, respectively, according to whether either of
the first and second dispense regions is tilted and/or contoured
relative to the XY plane, and/or rotated in the XY plane relative
to the other dispense region (i.e., locally rotated). At step 226,
if neither dispense region is tilted or contoured and there is no
local rotation, the system may proceed to step 228 and move the
first and second applicators together in the XY plane to dispense
the first and second fluid patterns. For example, such may be
accomplished with the primary positioner 36 of dispensing system 30
through x.sub.1 and y.sub.1 movements. Through step 228, the second
applicator need not be moved relative to the first applicator while
dispensing, because the dispense regions are neither tilted nor
contoured relative to the XY plane, nor rotated relative to each
other in the XY plane. In alternative to step 228, if the dispense
regions are rotated relative to each other in the XY plane, the
system proceeds to steps 230a and 230b. At steps 230a and 230b, the
system moves the first applicator in the XY plane, for example with
primary positioner 36, to dispense the first fluid pattern at the
first dispense region. Simultaneously, the system moves the second
applicator relative to the first applicator in the XY plane, for
example with secondary positioner 40, to dispense the second fluid
pattern at the second dispense region. Thereby, the system may
actively correct for local rotation while dispensing.
[0076] In an alternative to step 226, if the first dispense region
and/or the second dispense region is tilted and/or contoured
relative to the XY plane, the system may proceed to step 232.
Through step 232, the system moves the first and second applicators
according to whether the first and second dispense regions are
rotated relative to each other in the XY plane (i.e., locally
rotated). If the dispense regions are not locally rotated, the
system may proceed to steps 234a and 234b. At steps 234a and 234b,
the system may move the first and second applicators together in
the XY plane, as indicated in step 234a, for example with primary
positioner 36, to dispense the first and second fluid patterns
without relative movement between the applicators in XY.
[0077] Simultaneously, as indicated in step 234b, the system may
move the first applicator and/or the second applicator in Z along a
corresponding dispense height path (determined in step 214) to
account for tilt and/or contour of a corresponding dispense region
relative to the XY plane.
[0078] In alternative to steps 234a and 234b, if the dispense
regions are locally rotated in addition to at least one of them
being tilted and/or contoured, the system may proceed to steps
236a, 236b, and 236c. At step 236a, the first applicator is moved
in the XY plane, for example with primary positioner 36, to
dispense the first fluid pattern at the first dispense region.
Simultaneously, at step 236b, the second applicator is moved
relative to the first applicator in the XY plane, for example with
secondary positioner 40, to dispense the second fluid pattern at
the second dispense region. Simultaneously, at step 236c, the first
applicator and/or the second applicator is moved in Z along a
corresponding dispense height path to account for tilt and/or
contour of a corresponding dispense region relative to the XY
plane.
[0079] At step 238, upon completion of dispensing the first and
second fluid patterns, the first and second applicators may be
raised back up along the Z axis to their pre-dispense heights, for
example. At step 240, the system may evaluate whether there are
additional fluid patterns to be dispensed, for example at third and
fourth dispense regions. If there remains additional dispensing to
be performed, the system may return to step 208, as indicated by
symbol B. If all dispensing is complete, the system may end its
dispensing operations.
[0080] Methods of dispensing have been described above in
connection with specified orientations of first and second dispense
regions and corresponding movements of first and second applicators
for simultaneously dispensing at the first and second dispense
regions. However, persons skilled in the art will appreciate that
the methods described may be adapted as appropriate to
simultaneously dispense at any two dispense regions. For example,
where the first dispense region and/or the second dispense region
is uniquely tilted and/or contoured relative to the XY plane, the
system may move the first applicator and the second applicator
independently along X, Y, and/or Z while dispensing to
simultaneously dispense a first fluid pattern at the first dispense
region and a second fluid pattern at the second dispense
region.
[0081] While the present invention has been illustrated by the
description of specific embodiments thereof, and while the
embodiments have been described in considerable detail, it is not
intended to restrict or in any way limit the scope of the appended
claims to such detail. The various features discussed herein may be
used alone or in any combination. Additional advantages and
modifications will readily appear to those skilled in the art. The
invention in its broader aspects is therefore not limited to the
specific details, representative apparatus and methods and
illustrative examples shown and described. Accordingly, departures
may be made from such details without departing from the scope or
spirit of the general inventive concept.
* * * * *