U.S. patent number 3,818,823 [Application Number 05/260,338] was granted by the patent office on 1974-06-25 for heated, vacuum-pressure press.
This patent grant is currently assigned to Buckbee-Mears Company. Invention is credited to Herbert M. Bond.
United States Patent |
3,818,823 |
Bond |
June 25, 1974 |
HEATED, VACUUM-PRESSURE PRESS
Abstract
A combination heated, vacuum and pressure press is provided for
facilitating the transfer of a substance from a workpiece to which
it is weakly adhered to a substrate to which it is more permanently
adhered by means of a heat-activated thermosetting adhesive. The
press consists of a platen having vacuum passages therein with a
flexible blanket overlying the platen so that it may be drawn
tightly to the platen upon application of the vacuum and a cover in
the form of a dome sealingly engaging the platen and forming a
chamber thereover, the cover having an internal heating element and
the press having means to pressurize the interior of the chamber
formed between the platen and the cover so that positive pressure
can be exerted on the flexible blanket while the interior of the
dome is at the same time heated to assure perfect transfer of a
substance from a workpiece to a substrate underneath the
blanket.
Inventors: |
Bond; Herbert M. (Stillwater,
WA) |
Assignee: |
Buckbee-Mears Company (St.
Paul, MN)
|
Family
ID: |
26947935 |
Appl.
No.: |
05/260,338 |
Filed: |
June 6, 1972 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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869594 |
Oct 27, 1969 |
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Current U.S.
Class: |
100/322; 100/211;
156/230; 156/285; 156/583.3 |
Current CPC
Class: |
B44C
1/1712 (20130101); B30B 5/02 (20130101) |
Current International
Class: |
B30B
5/00 (20060101); B30B 5/02 (20060101); B44C
1/17 (20060101); B30b 015/34 () |
Field of
Search: |
;100/90,93P,211
;156/285,286,287,581,583,382,580,230,233,234,235,240,241 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Feldman; Peter
Attorney, Agent or Firm: Jacobson and Johnson
Parent Case Text
This is a division of application Ser. No. 869,594, filed Oct. 27,
1969, now abandoned.
Claims
What is claimed is:
1. A combination heated, vacuum-pressure press for facilitating the
adhesion of a substance to a substrate by the utilization of heat
and pressure comprising:
a platen surface having a face for receiving a work piece to be
assembled under heat and pressure, said platen surface having a
plurality of vacuum passages passing through said platen and
adaptable to be connected to a vacuum source;
a vacuum source, said vacuum source connected to said plurality of
vacuum passages to thereby produce a lower pressure region adjacent
the surface of said platen;
a dome disposed above said platen and having a concave bottom for
forming a chamber over the face of said platen, said dome having a
periphery being adapted for forming sealing engagement around the
area of said vacuum passages located on the surface of said platen,
said periphery of said dome including a sealing ring for forming
sealing engagement between said dome and said platen;
a flexible, nonporous heat conductive blanket located between said
dome and said platen, said flexible nonporous heat conductive
blanket adaptable for covering a work piece which is located on the
face of said platen and which is to be assembled by pressure and
heat, said flexible nonporous heat conductive blanket operable for
applying a force to the opposite sides of the article to be
assembled by heat and pressure, said flexible, nonporous heat
conductive blanket separating the chamber formed between said
platen and said dome into a high pressure region and a vacuum
region, said flexible, nonporous heat conductive blanket operable
for extending beyond the edges of the work piece to be assembled by
pressure and heat and the plurality of vacuum passages located in
said platen so that said flexible, nonporous heat conductive
blanket is operable for transmitting a force to the article which
is to be assembled by pressure and heat, a high pressure gas line
opening into the high pressure region in the chamber between said
dome and said platen for pressurizing the high pressure region
therein with a high pressure gas to thereby produce an internal
force;
means for holding said dome against said platen in sealing
engagement, said means producing sufficient force to counteract the
internal force within said dome and said platen which are produced
by pressurizing the high pressure region in the chamber between
said dome and said platen with high pressure gas; and
a heating element located in the high pressure region defined by
said platen and said dome, said heating element operable for
supplying heat to the article which is to be assembled by heat and
pressure.
Description
This invention relates to a vacuum press and more particularly
relates to a heated, vacuum-pressure press for facilitating the
transfer of a substance from one substrate to another in a rapid
and efficient manner on the press.
There are many instances in industry where it is desired to form a
substance, in the form of an article such as a decal, a printed
circuit, a metallized coating, etc. on one substrate and then
transfer it from that substrate to a more permanent backing or
substrate by the use of a thermosetting adhesive to adhere the
substance to the second substrate. Heretofore there has been no
simple straightforward way for doing this and a series of
operations have been required to press the two substrates together
to cause good contact between the substance to be transferred and
the substrate to which it is to be transferred combined with
subsequent heating operations at a later stage of the process and
culminating in yet another stage for the separation of the
substrates from one another with the substance transferred to the
proper substrate.
This invention provides a greatly simplified procedure capable of
being carried out on a single piece of apparatus to accomplish the
entire transfer in a very short period of time and which procedure
requires a minimum of skill in its operation.
In accordance with this invention a combination heated, vacuum and
pressure press is provided comprising a platen having vacuum
passages opening into the face thereof, a dome overlying the platen
and sealed to the platen around the platen area covered by the
vacuum openings, means maintaining the dome and the platen in
sealing contact with one another upon pressurization of the dome, a
non-porous, heat-conductive, flexible blanket interposed between
the dome and the platen within the area sealed by the dome edge,
means for pressurizing the interior of the dome with gas to exert
positive, super atomospheric, pressure on the blanket after the
blanket is held in place by a vacuum, and means within the dome to
heat the interior thereof.
Using the novel apparatus just described, a simple and efficient
method for transferring substances from one substrate to another is
provided. The apparatus is particularly useful in the transfer of
the delicate printed circuits from a workpiece to a transfer
substrate which is in the form of a thin, self-sustaining, flexible
film or sheet of heat-resistant electrical grade polymer.
In the practice of the process the workpiece is placed on the
platen, a flexible film having a thermosetting adhesive coating
thereon is placed thereover with the thermosetting adhesive coated
face in contact with the surface of the workpiece. The blanket is
then laid over this assembly with the blanket edges extending
beyond the assembly. A vacuum is then drawn to draw the workpiece
tight against the platen and to draw the flexible, preferably
elastic, blanket taut over the assembly. Thereupon, or therebefore,
the dome is pressed in place to form a sealed hollow chamber
overlying the platen and the blanketed assembly thereon. The
interior of the dome is then pressurized and heated to assure good
even contact of the flexible film to the metal circuit on the
workpiece and to activate the adhesive to adhesively secure the
circuit permanently to the flexible film. Upon release of the
pressure from the dome and of the vacuum from the platen (not
necessarily in the order stated), the dome is raised, the blanket
removed and the flexible film with the circuit attached separated
from the workpiece.
The invention will be described in more detail in conjunction with
the accompanying drawings wherein:
FIG. 1 is a side elevational view of a combination heat,
vacuum-pressure press made in accordance with this invention;
FIG. 2 is a top view of the vacuum platen of the press;
FIG. 3 is a bottom view of the dome of the press;
FIG. 4 is a cross-sectional view taken substantially along the
plane of section line 4--4 of FIG. 1 illustrating the interior of
the press during operation; and
FIG. 5 is a side elevational view of the transfer of a substance
from one substrate to another using the apparatus illustrated in
FIGS. 1-4.
Referring first to FIG. 1, the combination heated, vacuum-pressure
press of this invention is designated in its entirety by the
numeral 10. It is shown to comprise a supporting frame 12
supporting a horizontal rectangular frame 14, which table carries a
platen 16. Vertical corner members 18 rising from the horizontal
frame 14 having slidably mounted thereon a second horizontal
rectangular frame 20 for movement toward and away from the platen
16. Beneath the horizontal frame 20 and carried thereby is a dome
22, the peripheral edge of which is adapted to seal to the platen
16 when the dome is pressed into place against the platen.
Projecting centrally upwardly from the dome and fixedly attached
thereto is a piston 24 carried within a hydraulic or pneumatic lift
cylinder 26. The lift cylinder is mounted on a top horizontal frame
28 fixedly carried by the top of the corner supports 18. The
function of the lift cylinder is to raise and lower the dome 22 and
to maintain the dome in place in sealing relation around its
periphery to the platen 16. There is also illustrated a safety lock
pin 30 engaging the frame 20 carrying the dome and the frame 14
carrying the platen to prevent inadvertent dropping of the dome.
The operation of this safety lock pin is controlled by a safety
lock cylinder 32.
Illustrated somewhat schematically is a high pressure tube 34
leading from a high pressure air supply (not shown) through the
valve 36 into the passage 38 opening into the face of the platen
16; this is particularly illustrated by the small cross-sectional
detail showing in FIG. 1 for this purpose. There is also provided a
vacuum line 40 leading from a vacuum pump 42 through a vacuum
shut-off valve 44 into vacuum passages 46, shown in the small
cross-sectional detail in FIG. 1 for this purpose, also opening
into the face of platen 16.
In FIG. 2 the top surface of the platen 16 is illustrated showing
the vacuum openings 46 therein and also illustrating circular
sealing groove 48 around the periphery of the portion of the platen
16 having the vacuum openings therethrough. Also shown is the
opening 38 for admitting gas under pressure to the interior of the
dome through the platen 16. As will be noted this opening 38 is
inside the circular area of the platen 16 surrounded by the sealing
groove 48 but outside of the circular periphery of the vacuum
passage area of the platen.
In FIG. 3 the interior of the dome 22 is illustrated. The dome has
a concave interior with a large heating element 50 therein. The
bottom periphery of the dome is flat and carries therewithin a
sealing ring 52 which, when the dome is pressed in place against
the platen 16, sits within the groove 48 to form a sealed chamber
54 (FIG. 4) above the portion of the platen 16 surrounded by the
sealing groove 48.
In FIG. 4 the operation of the device is most clearly illustrated.
In that figure the dome 22 is shown pressed in place against the
platen 16 with the sealing ring 52 sealing the periphery of the
dome to the platen. A black rubber blanket 56 is shown stretched
over the work assembly, designated in its entirety by the numeral
58, and held tightly in place thereby by a vacuum drawn through the
vacuum openings 46 in the platen 16. The black rubber blanket 56 is
further held tight against the work assembly 58 by pressurizing the
chamber 54 through the high pressure line 34 and the interior may
at the same time be heated by means of the heating element 50,
which may be in the form of a conventional electric heating
coil.
The work assembly 58 in the preferred embodiment illustrated is
composed of a rigid plate 60 on which a copper or other metal
circuit 62 has been deposited by electroforming, or formed thereon
by other means, and which is only lightly adherent thereto.
Overlying the plate 60, which forms the workpiece, and the circuit
62 is a thin, flexible, self-sustaining film or sheet 64 of
electrical grade synthetic polymer, which has the face thereof
engaging the metal deposit 62 coated with a normally non-tacky
thermosetting adhesive coating (not shown) which, upon
thermosetting, also sets to a non-tacky state. By the combination
of the vacuum on the rubber blanket 56 and the positive pressure
exerted by the compressed gas in the interior of the dome heated by
means of the heating coil 50, the metal deposit is rapidly adhered
to the thin, flexible backing film 64 to such a degree that it
readily and completely separates from the workpiece 60, whereupon
it can be removed therefrom as illustrated in FIG. 5.
While the invention has been explained with respect to the transfer
of a metal circuit from a plate to a thin film, the apparatus and
the method can obviously be used to effect the transfer of a wide
variety of materials in a simple and efficient manner.
* * * * *