U.S. patent application number 12/985655 was filed with the patent office on 2011-04-28 for feeding mechanism for continuous processing of elongate base material, processing apparatus and thin film forming apparatus using the same, and elongate member produced thereby.
This patent application is currently assigned to SUMITOMO ELECTRIC INDUSTRIES, LTD.. Invention is credited to Hideaki AWATA, Katsuji EMURA, Jun NAKAMURA, Nobuyuki OKUDA, Kentaro YOSHIDA.
Application Number | 20110095121 12/985655 |
Document ID | / |
Family ID | 38837105 |
Filed Date | 2011-04-28 |
United States Patent
Application |
20110095121 |
Kind Code |
A1 |
AWATA; Hideaki ; et
al. |
April 28, 2011 |
FEEDING MECHANISM FOR CONTINUOUS PROCESSING OF ELONGATE BASE
MATERIAL, PROCESSING APPARATUS AND THIN FILM FORMING APPARATUS
USING THE SAME, AND ELONGATE MEMBER PRODUCED THEREBY
Abstract
A feeding mechanism, having a base station to which an elongate
base material is continuously fed to be physically or chemically
processed at a prescribed speed and from which the processed base
material is continuously recovered, wherein tensile force T.sub.1
in a direction opposite to a feeding direction is applied at a
supply side of the base station, frictional force F is applied at
the base station and tensile force T.sub.2 in the feeding direction
is applied at the recovery side of the base station, on said base
material, with these forces satisfying the relation of
F>T.sub.1>T.sub.2, is provided. A feeding mechanism for
feeding a base material for performing physical or chemical
processing with high accuracy while an elongate base material is
continuously fed, particularly a feeding mechanism that suppresses
thickness variation along the lengthwise direction or surface
damage at a portion where a function is added of the processed base
material, can be obtained.
Inventors: |
AWATA; Hideaki; (Itami-shi,
JP) ; EMURA; Katsuji; (Itami-shi, JP) ;
YOSHIDA; Kentaro; (Itami-shi, JP) ; OKUDA;
Nobuyuki; (Itami-shi, JP) ; NAKAMURA; Jun;
(Itami-shi, JP) |
Assignee: |
SUMITOMO ELECTRIC INDUSTRIES,
LTD.
Osaka
JP
|
Family ID: |
38837105 |
Appl. No.: |
12/985655 |
Filed: |
January 6, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
11797950 |
May 9, 2007 |
|
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|
12985655 |
|
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Current U.S.
Class: |
242/412.1 ;
198/339.1 |
Current CPC
Class: |
B65H 2555/24 20130101;
C25D 17/00 20130101; B65H 23/1806 20130101; Y10T 428/2495 20150115;
B65H 2301/51 20130101; B65H 2301/51145 20130101; C25D 7/0692
20130101; C25D 11/04 20130101; C23C 14/562 20130101 |
Class at
Publication: |
242/412.1 ;
198/339.1 |
International
Class: |
B65H 20/00 20060101
B65H020/00; B65H 23/04 20060101 B65H023/04 |
Foreign Application Data
Date |
Code |
Application Number |
May 10, 2006 |
JP |
2006-130923 (P) |
Claims
1-8. (canceled)
9. A method of processing an elongate base material on a feeding
mechanism including a base station, the method comprising steps of:
continuously feeding the elongate base material to the base
station; physically or chemically processing the elongate base
material at a prescribed speed to form a processed base material;
continuously recovering the processed base material, wherein
tensile force T.sub.1 in a direction opposite to a feeding
direction is applied at a supply side of the base station,
frictional force F is applied at the base station, and tensile
force T.sub.2 in the feeding direction is applied at the recovery
side of the base station, on said base material, with the T.sub.1,
F and T.sub.2 forces satisfying the relation of
F>T.sub.1>T.sub.2.
10. The method according to claim 9, wherein said tensile forces
T.sub.1 and T.sub.2 are adjusted in a complementary manner to
constant values in accordance with a change in difference of an
amount of said base material on said supply side and on said
recovery side, at least until said processing is finished over the
entire length of said base material.
11. The method according to claim 9, further comprising steps of:
feeding said base material in contact with rollers controlled by
torque motors on said supply side and said recovery side, and a
roller controlled by a servo motor at said base station in
between.
12. The method according to claim 9, wherein the relation of
F>T.sub.1>T.sub.2 is realized by setting speed of rotation of
a roller on the recovery side controlled by a torque motor on said
recovery side higher than speed of rotation of a base station
roller at said base station when said tensile force T.sub.1 is
0.
13. A processing apparatus configured to implement the method
according to claim 9.
14. A thin film forming apparatus configured to implement the
method according to claim 9.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a mechanism for feeding a
base material realizing highly accurate physical or chemical
processing continuously on an elongate base material.
[0003] 2. Description of the Background Art
[0004] A feeding mechanism for feeding elongate base materials of
various cross-sectional shapes, provided with a base station for
performing physical or chemical processing continuously at a
prescribed speed, has been often used for providing a function of a
prescribed standard over the entire length of the base materials.
By way of example, the physical or chemical processing may include:
quality alteration of base material surface by anodic oxidation of
an aluminum-based material, or electron beam irradiation on
chemical fiber; coating on the base material surface by forming a
resin layer on a thin metal line, plating, formation of metal foil,
or formation of a semiconductor layer or a magnetic layer on
ceramics; and shaping such as drawing or fine fluting of metal
lines. In such a feeding mechanism, it is necessary at least at the
base station to keep constant the speed of passage of the base
material. Therefore, it is necessary to apply appropriate tension
to the base material before and after it passes through the base
station, and to feed the base material along the same path over the
entire length.
[0005] It is noted that when the base material is soft material
such as resin, copper or aluminum, fragile material such as
ceramics or paper, or thin or fine material having small
cross-sectional area, for example, the base material tends to
deform by environmental influence such as external force or heat
while it is fed. Further, the base material is prone to damage as
it slides over and gets stuck on a roller or other member, or it
stretches and slips. Therefore, in order to ensure dimensional
accuracy over the entire length of the processed portion of such a
base material, it is necessary to feed at a constant speed and to
apply tension appropriate for the material, at portions upstream
and downstream of the base station.
[0006] It is particularly difficult to adjust the balance of
feeding tension when a thin layer is to be formed with high
dimensional accuracy on a surface of an elongate base material in
the form of a tape or fiber. A so-called winding type thin film
forming apparatus, in which an elongate strip-shaped material
(hereinafter simply referred to as a tape) is fed to a thin film
forming chamber and the film is continuously formed on the base
material, is widely used for manufacturing various tapes including
tapes for magnetic recording, printers and wrapping. Typically, a
tape is fed using rollers provided at a supply portion, a cooling
portion also serving as a base station, and a take-up portion on
the side of recovering the processed base material, while the tape
is kept in touch with a constant tension on the surfaces of these
rollers. Conventionally, there have been problems of the degree of
close contact between the tape and rollers, unevenness in film
thickness resulting from fluctuation in feeding speed and damage to
the film surface, and measures to avoid such problems have been
considered. In the following, the background of the invention will
be described with reference to the thin film forming apparatus as
an example.
[0007] Japanese Patent Laying-Open No. 62-247073 proposes a
mechanism that has a speed-variable sub-roller at least on one of
the tape feed side and tape delivery side of the cooling roller
also serving as the base station, in order to reduce variation in
the degree of close contact of the tape to the surface of cooling
roller, experienced every time a tape of different type is fed.
This approach, however, cannot avoid variation in film thickness
resulting from long/short time of vapor deposition, mottling or
surface scratches, as the speed of base material varies dependent
of the increase/decrease of outer diameter of wound base material
on the roller at the take-up portion.
[0008] Further, in order to lessen the damage to the base material
and the thin film caused by variations in tension exerted on the
base material or variations in the degree of contact between the
material and the roller, derived from stretch of the base material
or generation of a gas from the surface, Japanese Patent
Laying-Open No. 61-264514 proposes an easing method of providing a
dancer roller between the rollers. This approach, however, may have
a problem that the tape tends to slip, or smooth feeding of the
tape becomes difficult when frictional force F between the tape and
the cooling roller also serving as the base station becomes smaller
than the tensile force T.sub.2 in the feeding direction on the
recovery side take-up portion or smaller than the tensile force
T.sub.1 in the direction opposite to the feeding direction of the
supply side.
[0009] Further, in order to adjust tension on the base body on the
take-up side to lessen generation of wrinkles of the wound-up tape,
Japanese Patent Laying-Open No. 61-278032 proposes a method of
arranging a plurality of guide roller pairs on the recovery side,
to have tension gradient on the tape therebetween in the direction
of feeding kept at 10N/mm.sup.2 or lower. This approach is also
expected to have the same problem as posed in Japanese Patent
Laying-Open No. 61-264514.
SUMMARY OF THE INVENTION
[0010] An object of the present invention is to address these
conventional problems and to provide a mechanism for feeding a base
material realizing highly accurate physical or chemical processing
continuously on an elongate base material while the elongate base
material is fed continuously, particularly such a mechanism for
reducing thickness variation along the lengthwise direction or
surface scratches at portions of the processed base material to
which a function is added, as well as to provide a processing
apparatus and thin film forming apparatus using the mechanism and
the elongate member produced thereby.
[0011] The present invention provides a feeding mechanism for
continuously processing an elongate base material, having a base
station to which the elongate base material is fed continuously to
be physically or chemically processed at a prescribed speed and
from which the base material processed here is continuously
recovered, wherein tensile force T.sub.1 in a direction opposite to
the feeding direction is applied at the supply side of the base
station, frictional force F is applied at the base station and
tensile force T.sub.2 in the feeding direction is applied at the
recovery side of the base station, on the base material, to satisfy
the relation of F>T.sub.1>T.sub.2.
[0012] Further, the present invention provides a feeding mechanism
in which, within the above-described scope, the tensile force
T.sub.1 on the supply side and the tensile force T.sub.2 on the
take-up side are adjusted in a complementary manner to constant
values, while supply side torque and take-up side torque are
changed in accordance with a change in difference in amount of the
base material on the supply side and the recovery side. The present
invention further encompasses, within the above-described scope, a
mechanism in which the base material is fed while it is in contact
with a roller controlled by supply side and recovery side torque
motors and a roller controlled by a servo-motor at the base
station.
[0013] Further, the present invention also encompasses a processing
apparatus using any of the above-described feeding mechanisms,
particularly a thin film forming apparatus, as well as an elongate
member of which thickness variation in the lengthwise direction of
the surface layer formed over the entire length of the elongate
member is in the range of .+-.10% of the average value.
[0014] According to the present invention, when the elongate base
material is fed continuously and a specific function is added to
the base material at a base station on the route of feeding, it can
be fed easily at a constant speed while not excessive but
appropriate tensile force is applied to the base material.
Therefore, it is possible to obtain a member having a function
added, with few damage and superior dimensional accuracy (with
small variation) along the lengthwise direction of the base
material. The effect is particularly significant when the invention
is applied to a thin or fine material having small cross-sectional
area. By way of example, when a semiconductor layer is to be
vapor-deposited on a tape having the thickness of 10 .mu.m, a layer
of about 1 .mu.m can be formed with thickness variation along the
entire length direction adjusted to be within .+-.10%.
[0015] The foregoing and other objects, features, aspects and
advantages of the present invention will become more apparent from
the following detailed description of the present invention when
taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 schematically shows the feeding mechanism in
accordance with Embodiment 1 of the present invention.
[0017] FIGS. 2A and 2B show an example of the present invention and
a comparative example representing correlation between the distance
and speed of feeding the base material in accordance with
Embodiment 1 of the present invention.
[0018] FIG. 3 schematically shows an example of continuous
monitoring means for forming the outer diameter of wound base
material, in the feeding mechanism in accordance with the present
invention.
[0019] FIG. 4 illustrates the concept of the feeding mechanism in
accordance with an embodiment of the present invention, with guide
rollers and the like omitted.
[0020] FIG. 5 is a schematic perspective view showing an elongate
member having a surface layer of thin film formed over the entire
length while it is fed continuously along the lengthwise direction,
by the feeding mechanism in accordance with an embodiment of the
present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0021] The present invention relates to a feeding mechanism having
a base station to which an elongate base material is fed
continuously to be physically or chemically processed at a
prescribed speed and from which the processed base material is
continuously recovered, wherein tensile force T.sub.1 in a
direction opposite to the feeding direction is applied at the
supply side of the base station, frictional force F is applied at
the base station and tensile force T.sub.2 in the feeding direction
is applied at the recovery side of the base station, on the base
material, to satisfy the relation of F>T.sub.1>T.sub.2.
[0022] Here, it is necessary to compare the levels of tensile
forces T.sub.1 and T.sub.2 applied to the base material and the
frictional force F at the base station, and to select the base
material and processing conditions not causing excessive load on
the base material and not causing any trouble in adding the
function at the base station. By way of example, when soft material
such as copper foil, fragile material such as paper, or a thin or
fine material having small cross-sectional area along the feeding
direction is selected as the base material, it is necessary to
appropriately adjust the outer diameter and rotation speed of each
roller and magnitude of tensile forces T.sub.1 and T.sub.2 to be
applied to the base material, in accordance with the processing
capacity of the base station and the desired process time.
[0023] The base station is on route of the feeding mechanism, where
physical or chemical process is performed. As described above, at
this base station, the quality altering process to add a specific
function to the surface of the base material is performed, the
surface of the base material is covered with a specific functional
material, or the material is shaped in a prescribed shape along the
feeding direction. This portion is also relayed by feeding members
such as rollers, as in the above-described thin film forming
apparatuses. At this portion, as the tension is applied to the base
material that is being fed, friction occurs by sliding contact with
the feeding member or the counterpart for adding the function.
[0024] In the feeding mechanism of the present invention, the base
material receives tensile force T.sub.1 in a direction opposite to
the feeding direction on the supply side, and receives tensile
force T.sub.2 in the feeding direction on the recovery side,
respectively, of the base station. By appropriately determining the
tensile forces on the supply side and the recovery side in a range
that satisfies the relation of F>T.sub.1>T.sub.2, not
imposing excessive load on the base material and appropriate for
the frictional force at the base station, feeding at a constant
speed adequate for the desired process time becomes possible at the
base station. Therefore, even when tensile forces T.sub.1 and
T.sub.2 vary within this range because of the decrease in the
amount of base material on the supply side and the increase in the
amount of base material on the recovery side, the actual speed of
feeding the base material is not influenced.
[0025] In the feeding mechanism in accordance with the present
invention, the base material is fed, driven by the base station.
When the base station is stationary, the base material is not fed,
as T.sub.1 and T.sub.2 are set smaller than F, though tensile
forces are applied to the base material. The speed of feeding the
base material can accurately be adjusted to be the same as the
speed of movement of the base station, when control is done to
always satisfy the relation of F>T.sub.1>T.sub.2.
[0026] Therefore, compared with the above-described conventional
feeding mechanism having a sub-roller or a dancer roller for speed
adjustment arranged in the midway, the influence of variation with
time in the amount difference on the supply side and the recovery
side can be suppressed, even though the number of such relaying
feeding portions is small. Therefore, processed base material
having small variation in functional quality level such as the
dimension along the lengthwise direction, can be provided, and
damage caused by sticking of the base member on the base station or
caused by stretch or friction of the material resulting from
excessive load can significantly be reduced. Naturally, any means
may be used as the feeding member (such as a roller) and the
tensile force adjusting means on the supply side, base station and
recovery side.
[0027] FIG. 4 schematically shows the concept of the feeding
mechanism in accordance with one embodiment of the present
invention, in which guide roller and the like are omitted.
Referring to FIG. 4, the feeding mechanism of the present
embodiment feeds base material 1 by means of a base station roller
3 and, therefore, frictional force F is applied by base station
roller 3 to base material 1. Base material 1 is fed by this
frictional force.
[0028] At this time, the feed speed v3 at base station roller 3 is
the same as feed speed v1 at roller 2 on the supply side and feed
speed v2 at roller 4 on the recovery side. Here, assuming that
frictional force F of base station roller 3 fully acts as the force
for feeding base material 1, no tension generates at this time on
base material 1 between supply side roller 2 and base station
roller 3 and on base material 1 between recovery side roller 4 and
base station roller 3.
[0029] When there is no tension applied on base material 1, it is
impossible to apply frictional force F of base station roller 3 to
base material 1. Therefore, in order to apply tension on base
material 1 between supply side roller 2 and base station roller 3,
tensile force T.sub.1 in a direction opposite to the feeding
direction is applied to base material 1, by supply side roller 2.
Further, in order to apply tension on base material 1 between
recovery side roller 4 and base station roller 3, tensile force
T.sub.2 in the same direction as the feeding direction is applied
to base material 1 by recovery side roller 4.
[0030] Here, if the tensile force T.sub.1 in the direction opposite
to the feeding direction exceeds frictional force F, it becomes
impossible to feed base material 1 by base station roller 3.
Therefore, the relation of F>T.sub.1 must be satisfied.
[0031] If the tensile force T.sub.2 on the recovery side exceeds
the tensile force T.sub.1 on the supply side, base material 1 would
be pulled to the recovery side with base station roller 3 serving
as a boundary, and base material 1 would slip over base station
roller 3 to the recovery side. Therefore, the relation of
T.sub.1>T.sub.2 must be satisfied.
[0032] From the foregoing, it can be seen that base material 1 can
be fed by base station roller 3 and slipping of base material 1 at
base station 3 can be prevented when the relation of
F>T.sub.1>T.sub.2 is satisfied.
[0033] The feeding mechanism of the present invention is controlled
such that the speed of rotation of recovery side roller controlled
by a recovery side torque motor is made higher than the speed of
rotation of the base station roller at the base station when the
tensile force T.sub.1 is 0, so that the relation of
F>T.sub.1>T.sub.2 is satisfied. If the state of T.sub.1=0
should happen, the frictional force F generated by base station
roller would not be applied to the base material. Therefore, it is
necessary to quickly wind-up the base material by the recovery side
roller and to apply tension to the base material, so that the base
material can receive the frictional force from the base station
roller. Specifically, it is necessary to adjust the speed of
rotation of the recovery side roller (that is, angular velocity
.omega.2: FIG. 4) to be higher than the speed of rotation of base
station roller (angular velocity .omega.3: FIG. 4), to increase the
speed of taking-up (speed of feeding) the base material.
[0034] As an example of the embodiment for this purpose, a method
is proposed in which tensile force T.sub.1 and tensile force
T.sub.2 are adjusted in a complementary manner to constant values
by varying rotation torque of motors (for example, by varying
rotation torque of feeding members such as respective rollers) in
accordance with the difference in amount of base material on the
supply side and on the recovery side (the amount of base material
wound around the supply side roller and the recovery side roller),
at least until processing at the base station is finished on the
entire length of the base material. This will be described with
reference to an example of roller feeding. Torque motors are
mounted beforehand on supply side and recovery side rollers, change
in outer diameter of the base material wound on the two rollers is
detected by a sensor or the like, the information is processed, and
torque control commands are sent to motors so that a constant
tension runs on the base material. For instance, a method may be
used in which the outer diameter of the wound base material at the
time point may be monitored continuously by a CCD camera, and the
image data may be converted to the amount of torque change and fed
back.
[0035] In this manner, excessive load on the base material can be
avoided and, in addition, by appropriately determining tensile
forces T.sub.1 and T.sub.2 in accordance with the frictional force
F at the base station, feeding at a constant speed adequate for the
desired process time becomes possible at the base station.
Naturally, any means may be used for the feeding members on the
supply side, base station and recovery side and for the tensile
force adjusting means. By way of example, various members including
a roller, a belt, or a rail may be used as the feeding member.
[0036] A specific example of an embodiment of the present invention
includes rollers controlled by supply side and recovery side torque
motors and a roller controlled by a servo motor at the base
station, and the base material is fed while it is kept in contact
with the rollers. On the supply side and on the recovery side with
the base station in between, rollers, on which the elongate base
material is wound, are positioned. These rollers each have the
rotation torque controlled by a torque motor. In order to avoid
excessive load on the base material and to enable feeding of the
base material at a constant speed adequate for the magnitude of
frictional force F, the roller at the base station is driven by a
servo motor that allows speed adjustment. Naturally, a guide roller
or a pinch roller may appropriately be provided additionally on the
supply side and/or recovery side, so that the base material is
brought into contact with an adequate contact area with the base
station roller.
[0037] The effect of the feeding mechanism in accordance with the
present invention is particularly significant when a functional
portion of a prescribed dimension is to be formed on a thin or fine
elongate material having small cross-sectional area along the
feeding direction. Particularly, it is possible to easily reduce
variation in thickness, depth or change in shape along the
lengthwise direction, when a thin film having the thickness of up
to several hundred .mu.m is to be formed, surface processing to
such a depth is to be done or a process involving change in shape
of similar dimension is to be performed. Therefore, an elongate
member 10 such as shown in FIG. 5 may easily be provided on which a
surface layer (for example, thin film) 11 is formed along the
entire length of elongate base material 1 having the thickness of
about 10 .mu.m, with thickness variation in the range of .+-.10% of
its average value.
[0038] In the following, the present invention will be described
with reference to specific examples, while the invention is not
limited to the contents below.
Example 1
Formation of Si Vapor-Deposited Layer on Metal Foil Tape
[0039] Referring to FIG. 1, base material 1 is fed from supply side
roller 2, brought into contact with a guide roller 23, fed to
roller 3 at the base station, brought into contact with a guide
roller 43 and taken up by recovery side roller 4 and recovered.
Supply side roller 2 is set to receive tensile force T.sub.1 in the
direction opposite to the feeding direction by a motor 21, for
example, through an electromagnetic torque control mechanism 22,
and to transmit the tensile force to base material 1. On the other
hand, recovery side roller 4 is set to receive tensile force
T.sub.2 in the feeding direction by a motor 41 through an
electromagnetic torque control mechanism 42, and to transmit the
tensile force to base material 1.
[0040] The outer diameter of the roller on which the base material
is wound can be confirmed by processing an image picked up by a CCD
camera as shown in FIG. 3. Referring to FIG. 3, base material 1 is
wound around a roller, the roller has a core 5, and a CCD camera 6
detects outer diameter 7 of base material 1. Here, camera 6 is
movable along the direction shown by an arrow in the figure. In
this state, first, camera 6 moves in the radial direction to detect
the outermost circumference based on contrast, then moves in the
axial direction to detect the outer circumference of an exposed
core bar in the similar manner, and measures the outer diameter
from the difference in coordinates of the two. Torque motor output
is controlled such that a product of the measured outer diameter
and the torque motor output attains to a predetermined value.
[0041] Roller 3 at the processing base station shown in FIG. 1 is
set to control the difference in tensions constantly in an
appropriate range, by means of servo motor 31. A contact angle of
base material 1 to the roller (central angle corresponding to the
outer circumference where the base material 1 is in sliding contact
with the roller, indicated by .theta. in the figure) is determined
by adjusting the distance between shafts of guide rollers 23 and
24.
[0042] Using a vapor deposition apparatus having such a feeding
mechanism, a silicon (Si) layer having the average thickness of 5
.mu.m was formed on a copper foil tape as the base material having
the width of 130 mm and thickness of 10 .mu.m. Vapor deposition was
done on a copper roller (cooling roller) containing coolant
provided at the base station. The two guide rollers are arranged
such that the contact angle .theta. of the tape to the roller
becomes approximately 220.degree.. Based on the contact area of the
base material estimated from the contact angle, coefficient of
friction between the base material and the roller confirmed
beforehand by an experiment and the supply side and recovery side
tensions, friction load of 300 g between the base material and the
roller was confirmed. This represents the load of the level that
does not cause any damage to the base material resulting from
stretch of the base material itself.
[0043] Until feeding of the entire length ends, the outer diameter
of the wound base material continuously decreases on the supply
side and continuously increases on the recovery side, and
therefore, compensation with time is necessary to lessen variation
in quality of the vapor-deposited layer. It is also necessary to
determine appropriate range of roller rotation speed in view of
cooling capacity of the roller, minimum necessary time of vapor
deposition and tolerable range of friction load not excessive to
the base material. From the foregoing, the speed of rotation of the
recovery side roller was estimated in advance such that it was
higher than the speed of rotation of the base station roller when
T.sub.1=0, additionally taking into account the tension control
level by the torque motors and the servo motor, and a feeding
program was prepared.
[0044] As a result, the speed of rotation of the roller at the
vapor deposition base station was set to 0.2 RPM (rotations per
minutes, equivalent to feeding speed of 100 m/min), tensile forces
corresponding to T.sub.1 and T.sub.2 were set to 168 g (initial) to
210 g (final) for the former, and 125 g (initial) to 100 g (final)
for the latter, respectively. In this manner, a layer having
average thickness at 20 points of 5 .mu.m, with its variation being
.+-.0.4 .mu.m (0.4 .mu.m in standard deviation, .+-.8% as a ratio
relative to the average thickness) was formed over the length of
100 m of the base material. The base material and the formed layer
were free of any scratch caused by sticking or stretch. As to the
tape feeding speed, a detection roller was brought into contact
with the base material surface on the recovery side, feeding
distance was measured by an attached rotary encoder, and with an
operation of a timer, the speed was intermittently confirmed. The
results are as shown in FIG. 2A.
[0045] For comparison, vapor deposition was conducted under the
same conditions as above, except that the control mechanism based
on the servo motor of the roller at the vapor deposition base
station was omitted. As to the tape feeding speed, the speed at a
detecting position on the recovery side mentioned above was kept
constant using the torque control mechanism on the recovery side,
by transmitting a recovery signal from the recovery side to the
recovery side roller. The results are as shown in FIG. 2B. As can
be seen from these results, variation in speed of the comparative
example shown in FIG. 2B is twice as much as in the example of the
present invention shown in FIG. 2A. From the result of comparison,
it was found that in the comparative example, tensile force
difference .DELTA.T (that is, T.sub.1-T.sub.2) applied in the
feeding direction was sometimes 0 when the speed was low, in the
comparative example. Further, in the similar manner as in the
example of the present invention, variation in thickness along the
lengthwise direction was confirmed. In the comparative example, the
average value was confirmed to be 5 .mu.m, and its variation was
confirmed to be .+-.1.3 .mu.m (in standard deviation, .+-.26% as a
ratio relative to the average thickness). When feeding proceeded to
the final stage, a point of maximum speed and a point of minimum
speed appeared. At the point of maximum speed, a dent (stretch of
the base material) exceeding the variation was observed on the
surface of the layer, and at the point of minimum speed, slight
scratch was observed on the surface.
Example 2
Formation of a Magnetic Layer on Resin Tape
[0046] Using the same feeding mechanism and similar setting program
as in Example 1, a tape of polyester having the width of 400 mm and
the thickness of 20 .mu.m was fed, and a layer of cobalt-nickel
magnetic alloy (chemical composition: cobalt 85 mass %, nickel 15
mass %) having average thickness of 0.1 .mu.m was formed over 100
m. The speed of rotation of the roller at the vapor deposition base
station was set to the constant speed of approximately 0.04 RPM
(rotations per minutes, equivalent to feeding speed of 20 mm/min),
the friction load was set to approximately 30 kg, and the tensile
load on the base material near the roller on the supply side was
gradually increased and the tensile load on the recovery side was
gradually decreased, so that the tensile load difference was set to
about 10 kg, and continuous vapor deposition was conducted. As a
result, a magnetic layer of which thickness variation over the
entire length was .+-.6% to the average value of 0.1 .mu.m was
obtained. There was no damage observed on the surface. For
comparison, a vapor deposition layer was formed while the speed was
adjusted simply by torque control on the recovery side, with the
servo mechanism of the base station roller omitted, as in the
example of copper foil described above. Then, the thickness
variation was third times as large, and scratches and other damage
were observed in places.
Example 3
Formation of Alumite on Rail of Aluminum Alloy
[0047] A rail-shaped base material of Al--Mg--Si based alloy having
a square bracket shape (with the outer bottom side having the
thickness of 1 mm and width of 3 mm, and raised portions having the
thickness of 1 mm and the height of 1.5 mm, formed perpendicular to
the bottom side on opposite sides) was prepared. On the entire
outer bottom surface, an anode oxide layer having an average depth
of 10 .mu.m was formed over the entire length of 100 m. Portions
other than the bottom surface of the base material was masked
beforehand with resin. The base material was wound around a
rotational winding roller on the supply side, with a spacer
interposed at every turn. Tensile load of 7 kg in the direction
opposite to the feeding direction was applied by a torque control
motor to the winding portion, and similarly, tensile load of 4 kg
in the feeding direction was applied to the winding portion of the
same type on the recovery side, with an anode oxidizing apparatus
positioned in between. To the base material, the force exceeding
the difference of 3 kg was applied by the friction with the roller
for oxidation process, and the base material was fed continuously.
The feeding program described above was set such that feeding to
the recovery side is done even if T.sub.1 attains to T.sub.1=0. The
base material fed from the supply side to the anode oxidizing bath
was first brought into contact, from an inlet, with two stages of
oxidizing rollers having servo control mechanism, subjected to
washing and drying at the third stage and fourth stage rollers,
respectively, and then discharged from an outlet. Thereafter, the
material was taken up by the winding portion on the recovery side.
The total friction load at the oxidizing bath was 10 kg. During the
process, the tensile load was adjusted to increase gradually on the
supply side and to decrease gradually on the recovery side.
[0048] Variation in depth of the oxide layer formed through the
process described above was confirmed along the entire length,
using samples taken at equally spaced 20 sections, by oxygen line
analysis of the cross-section with a scanning electron microscope.
As a result, variation was .+-.0.6 .mu.m (.+-.6%) with respect to
the average value of 10 .mu.m. No damage was observed on the
surface over the entire length.
[0049] By using the feeding mechanism in accordance with the
present invention, when an elongate base material is fed
continuously and a specific function is added to the base material
at a base station on route, it is possible to obtain a member
having the function added to its surface, with few damage and
superior dimensional accuracy (with small variation) along the
lengthwise direction of the base material. The effect is
particularly significant in feeding a thin or fine material having
small cross-sectional area.
[0050] Although the present invention has been described and
illustrated in detail, it is clearly understood that the same is by
way of illustration and example only and is not to be taken by way
of limitation, the spirit and scope of the present invention being
limited only by the terms of the appended claims.
* * * * *