U.S. patent number 3,878,062 [Application Number 05/374,535] was granted by the patent office on 1975-04-15 for electroplating apparatus and method.
This patent grant is currently assigned to GTE Sylvania Incorporated. Invention is credited to Thomas E. Byler, Guy M. Grimaldi, Charles D. Seekings.
United States Patent |
3,878,062 |
Grimaldi , et al. |
April 15, 1975 |
**Please see images for:
( Certificate of Correction ) ** |
Electroplating apparatus and method
Abstract
There is described an apparatus for electroplating preselected
portions of individual articles. The apparatus comprises a track
member adapted for having the articles travel therealong, a supply
means for supplying the articles to the track member, a vibratory
means engaged to the track member for effecting movement of said
articles along the track member, a container adapted for containing
a predetermined quantity of electolyte solution therein and
positioned substantially below and related to the track member,
means for controlling the elevation of the electrolyte solution
within the container in order that the solution contacts the
preselected areas on the articles as these articles travel along
the track member, means for controlling the rate of travel of the
articles, a first electrode means associated with the articles, and
a second electrode means of opposite polarity than the first
electrode means and associated with the electrolyte solution. A
method for electroplating preselected areas on individual articles
is also disclosed.
Inventors: |
Grimaldi; Guy M. (North Warren,
PA), Byler; Thomas E. (Pittsfield, PA), Seekings; Charles
D. (Youngsville, PA) |
Assignee: |
GTE Sylvania Incorporated
(Seneca Falls, NY)
|
Family
ID: |
23477265 |
Appl.
No.: |
05/374,535 |
Filed: |
June 28, 1973 |
Current U.S.
Class: |
205/128; 204/202;
204/222; 204/224R; 205/137 |
Current CPC
Class: |
C25D
5/02 (20130101) |
Current International
Class: |
C25D
5/02 (20060101); C23b 005/48 (); B23p 001/02 ();
C23b 005/76 () |
Field of
Search: |
;204/224R,198-205,15,222,223 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Tufariello; T. M.
Attorney, Agent or Firm: O'Malley; Norman J. Fraley;
Lawrence R. Castle; Donald R.
Claims
1. An apparatus for electroplating preselected portions of
individual articles, said apparatus comprising:
a track member adapted for having each of said articles travel
therealong;
supply means for supplying said articles to said track member;
vibratory means engaged to said track member for effecting movement
of said articles along said track member;
a container adapted for containing a predetermined quantity of
electrolyte solution therein, said container positioned
substantially below and related to said track member;
means for controlling the elevation of said electrolyte solution
within said container whereby said solution contacts said
preselected portions of said articles which protrude beneath the
track member as said articles travel along said track member;
means for controlling the rate of travel of said articles along
said track member;
first electrode means associated with said articles as said
articles travel along said track member; and
second electrode means of opposite polarity than said first
electrode means and associated with said electrolyte solution, said
second electrode means spacedly positioned adjacent said
preselected portions of said articles as
2. The apparatus according to claim 1 wherein said vibratory means
engaged to said track member for effecting movement of said
articles along said track member comprises a plurality of
individual vibratory members
3. The apparatus according to claim 1 wherein said supply means for
supplying said articles to said track member comprises a vibratory
feed
4. The apparatus according to claim 1 including a rinse means for
applying rinse solution to said preselected portions of said
articles after said portions have contacted said electrolyte
solution within said container.
5. The apparatus according to claim 4 wherein said rinse means
is
6. The apparatus according to claim 1 including a recirculation
means adapted for recirculating said electrolyte solution within
said container.
7. The apparatus according to claim 6 wherein said recirculation
means
8. The apparatus according to claim 4 including a recirculation
means
9. The apparatus according to claim 8 wherein said recirculation
means
10. The apparatus according to claim 1 wherein said means for
controlling the elevation of said electrolyte solution within said
container comprises an adjustable drain member positioned within
the portion of said container
11. The apparatus according to claim 1 wherein said means for
controlling the rate of travel of said articles along said track
member comprises a rotating disc member having a plurality of
individual notches formed therein, each of said notches adapted for
engaging one of said articles
12. The apparatus according to claim 1 wherein said first electrode
means associated with said articles comprises a cathode member and
said second electrode means associated with said electrolyte
solution comprises an
13. A method for electroplating preselected portions of individual
articles comprising:
supplying said articles to a track member;
effecting a vibratory movement to said articles along said track
member while an electrolyte solution contacts preselected portions
of said articles which protrude beneath the track member; and
applying an electrical potential to said articles and an electrical
potential of an opposite polarity to said electrolyte solution,
thereby providing deposition of a metal on said preselected
portions of said
14. The method according to claim 13 wherein said electrical
potential applied to said articles is provided by a cathode member
and said electrical potential of opposite polarity applied to said
electrolyte solution is provided by an anode member.
Description
BACKGROUND OF THE INVENTION
The invention relates to electrical deposition or plating of a
metal or alloy of metals on preselected portions of individual
articles in order to provide desired characteristics in these
areas. More particularly, the invention relates to a method and
means for achieving electrical plating of preselected portions of
individual articles with precious metals thereby making it
imperative that the plating be substantially confined to these
portions. Even more particularly, the invention relates to a means
and method for accomplishing the afore-described localized plating
on large quantities of articles in relatively short periods of
time.
In the manufacture of various individual articles, notably articles
useful in the electronic industry, it is often desirable to plate
these articles with a precious or similar type metal or alloy of
metals, the purpose being to provide these articles with improved
characteristics such as electroconductivity. One particular method
for achieving this plating on relatively large quantities of
articles is known as "barrel" plating. This process consists of
placing articles in a submergible barrel-type device which is then
placed in a bath of electrolyte solution. The barrel is then
rotated at a predetermined speed, electrical current is applied to
achieve the plating, and each article receives a substantially
uniform deposition of material thereon. While "barrel" plating does
achieve electrical deposition on large quantities of articles, it
can be readily understood that this method does not provide a means
for providing such deposition on only preselected areas of said
articles. Accordingly, utilization of "barrel" plating when only
preselected portions of the articles are to be plated results not
only in an unnecessary waste of materials, but also proves costly
by manufacturing standards.
It is believed, therefore, that an apparatus and method which could
selectively electroplate preselected portions of individual
articles and do so on relatively large quantities of articles in
relatively short periods of time would constitute an advancement in
the art.
OBJECTS AND SUMMARY OF THE INVENTION
It is therefore a primary object of this invention to provide an
apparatus for electroplating preselected portions of relatively
large quantities of individual articles during relatively short
periods of time.
It is another object of this invention to provide a method which
incorporates the above-described apparatus.
A still further object of this invention is to provide an
electroplating apparatus and method which are relatively
inexpensive to utilize and comparatively simple to operate.
In accordance with one aspect of this invention there is provided
an apparatus for electroplating preselected portion of individual
articles. The apparatus comprises a track member adapted for having
these articles travel therealong, a supply means for supplying
these articles to the track member, a vibratory means engaged to
the track member for effecting movement of the articles along the
track member, a container adapted for containing a predetermined
quantity of electrolyte solution therein, means for controlling the
elevation of the electrolyte solution within the container in order
that this solution contacts the preselected portions of the
articles as the articles travel along the track member, means for
controlling the rate of travel of the articles, a first electrode
means associated with the articles, and a second electrode means of
opposite polarity than said first electrode means and associated
with the electrolyte solution.
In accordance with another aspect of this invention, there is
provided a method for electroplating preselected portions of
individual articles, this method comprising the steps of: (a)
supplying the articles to a track member, (b) effecting a vibratory
movement to the articles while the electrolyte solution contacts
these preselected portions of the articles, and (c) applying an
electrical potential to the articles and an electrical potential of
opposite polarity to the electrolyte solution thereby providing
deposition of a metal on the preselected portions of the
articles.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front elevational view of the apparatus in accordance
with one embodiment of the present invention.
FIG. 2 is an isometric view of the container of the present
invention.
FIG. 3 is a side elevational view as taken along the lines 3--3 in
FIG. 1.
FIG. 4 is an isometric view illustrating the means for controlling
the rate of travel of the articles which are to be electroplated by
the present invention.
FIG. 5 illustrates an example of one article which may be plated by
the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
For a better understanding of the present invention together with
other and further objects, advantages and capabilities thereof,
reference is made to the following disclosure and appended claims
in connection with the above-described drawings.
With particular reference to FIG. 1, there is illustrated a front
elevational view of the subject invention, electroplating apparatus
10 which is shown to comprise a track member 11, supply means 13,
vibratory means 15, a container 17 adapted for having a
predetermined quantity of electrolyte solution therein, means for
controlling the rate of travel of articles as these articles travel
along the track member 11, this means illustrated as a rotating
disc member 19, a first electrode means 21 associated with the
articles, and a second electrode means 23 associated with the
electrolyte solution. Second electrode means 23 is illustrated in
FIG. 2 as being affixed to the container member 17. As also can be
seen in FIG. 2, apparatus 10 comprises a means for controlling the
elevation of the electrolyte solution within container 17, this
means illustrated as an adjustable drain member 25 positioned
within container 17.
In the preferred embodiments, supply means 13 comprises a vibratory
feed mechanism which is capable of supplying individual articles 27
to track member 11. Such a feed mechanism, often referred to as a
rotary or bowl vibratory feeder of a rotating vibratory machine, is
well known in the art and commercially available from several
sources. As articles 27 are supplied to track member 11, portions
of these articles protrude from beneath the track member as shown
in FIG. 1. As will be explained, these portions comprise the
preselected areas on the articles which are to receive electrical
deposition thereon. As articles 27 travel along track member 11,
these preselected areas travel through a portion of container 17
which is positioned substantially below track member 11. During
their period of travel through container 17, the preselected areas
of articles 27 are each contacted by the electrolyte solution
within the container. Electrical current is then supplied to first
electrode means 21 and second electrode means 23 to thereby achieve
the deposition desired. After leaving container 17 and having this
electrical deposition thereon, articles 27 are then removed from
track member 11 by rotating disc member 19. The operation of this
disc member will be explained with description of FIG. 4.
To provide movement of articles 27 along track member 11, vibratory
means 15 is provided. Means 15 in the preferred embodiment
comprises a plurality of individual vibratory members 29 spacedly
positioned along and engaged to track member 11 to effect movement
of the articles therealong. Each vibratory member comprises a
compact self-contained magnetic motor which generates straight line
vibratory motion when electrical current is passed through its
internal windings. These are referred to as VibroBlock generators
and may be purchased from the Arthur G. Russell Company,
Incorporated, from Bristol, Conn. At least six such motors are
preferably used, three on each side of track member 11. By
alternating the cycles of vibration for each motor, track 11 is
vibrated in such a manner that articles 27 will travel therealong
in the direction indicated. Each of the vibratory members 29 are
positioned on a corresponding bracket member 43 which in turn is
fixedly positioned on support frame 45. Frame 45, as is reservoir
31, is positioned on surface 39. Each vibratory member 29 in turn
is connected to track member 11 via a flange 47, this embodiment
best shown in FIG. 3.
Positioned below container 17 is a collection reservoir 31 which
serves to collect the overflow of electrolyte solution from
container 17, thereafter recirculating it back to the container. To
achieve this recirculating, a recirculation means 33 is provided
and shown to comprise a filter 35 and a pump member 37. Reservoir
31 is positioned within apparatus 10 by simply placing the
reservoir on a surface 39 of the apparatus. Container 17, on the
other hand, is positioned above and partially within reservoir 31
by support members 41 (also shown in FIG. 2).
As illustrated in FIG. 3A, track member 11 is shown to comprise a
pair of opposingly aligned top portions 49 and 49' and a pair of
opposing aligned bottom portions 51 and 51'. Top portions 49 and
49' are secured to flanges 47 while bottom portions 51 and 51' are
secured to top portions 49 and 49' respectively. A preferred
material for top portions 49 and 49' is polyvinyl chloride, while a
material preferred for bottom portions 51 and 51' is brass or any
of the similar good electrically conductive materials. First
electrode means 21 is also illustrated in FIG. 3A and is shown to
comprise the cathode member 53 of the present invention. Cathode
member 53 which is electrically connected to an external circuit
(not shown) thereby provides negative potential to each article 27
as the article travels through a substantially centrally located
slot 55 within the track member 11. Also shown in FIG. 3A and
better illustrated in FIG. 2 is the second electrode means 23 which
comprises the anode member of the present invention. Anode member
57, submerged within the electrolyte solution and spacedly
positioned adjacent the preselected areas of articles 27 to receive
deposition, comprises a platinum wire which in turn applies
positive potential to the electrolyte solution to achieve a
deposition during the plating step of the operation. This anode is,
in general, the nonconsumable type, that is the anode does not
furnish the metal to be coated. Anode member 57 is retained within
container 17 in the manner indicated in FIG. 2 and is electrically
connected to an external circuit (not shown) via connecting wires
59. As can be appreciated, second electrode means 23 can comprise
more than a single wire. At least two wires could be utilized, each
being positioned on one side of the article to be plated as the
article travels through container 17.
Relatively low current densities are utilized with the present
invention. For example, a desired rate for plating is approximately
140 articles per minute. With the overall average amperage at
approximately 3.9 amps, a current density of about 35 amps/sq. ft.
is utilized to obtain an average 40 millionths of an inch thickness
of deposit on the plated area. The above example is not meant to be
restrictive, however, as several alterations to the above figures
are permissible.
A better view of the positioning relationship between container 17,
collecting reservoir 31, track member 11 and vibratory members 29
can be seen in FIG. 3. As shown, container 17 is positioned upon
support member 41 which in turn overlaps the upstanding sides of
reservoir 31. As also can be seen in this Figure, brackets 43 which
hold vibratory members 29 are positioned on frame 45 which in turn
is fixedly attached to surface 39. There is thus shown a means by
which vibrational motion is indirectly supplied to each article
which is to be plated. This motion is provided by vibratory members
29 via flanges 47, top portions 49 (or 49') and bottom portions 51
(or 51') of track 11. The areas of the articles that have been
successfully plated by the present invention have exhibited many
improved characteristics particularly with regard to brightness and
adherence. It is believed that a relationship exists between the
described vibrational motion imparted and the described subsequent
improved characteristics in the plated areas. It is further
believed that these improvements are the result of the effect of
the described vibrational motion on the settling properties of the
metal ions in the electrolyte solution, that is, this settling is
believed improved by providing such motion.
With reference to FIG. 2, container 17 is illustrated and shown to
comprise an electrolyte solution containing portion 60 and a rinse
solution containing portion 61. Thus, it can be seen that as
articles 27 travel along track member 11 in the direction of travel
indicated in FIG. 2, the preselected portions to receive electrical
deposition are adapted for traveling through designated cutaway
portions 63 within container 17. Thus, there is shown a method by
which these preselected areas will first contact the electrolyte
solution afterwhich they contact a rinse solution. In the preferred
embodiment, the rinse solution is deionized water. The
electroplating solutions that are useful in this invention are
known in the art. For example, gold patterns are deposited from an
electroplating solution containing a gold concentration of about 1
to 1.25 ounces per gallon. Some examples of suitable gold plating
solutions are sold by the Sel-Rex Corporation under the trade names
"Autronex N," "Autronex NI," "Autronex C," and "Autronex CI." Those
of the above examples which contain the "N" or "NI" designate are
nickel alloy solutions of varying concentrations while those
containing the "C" or "CI" designate are different concentrations
of co alt alloy solution. The above solutions are not meant to
restrict the present invention, however, as practically any metal,
such as nickel, tin and the like, that is generally deposited by
the apparatus and method of the present invention.
The electrolyte solution is supplied container 17 via piping 65
which terminates in the electrolyte solution containing portion of
container 17 at a T-shaped nozzle 67. Nozzle 67 as shown has its
end portions sealed off and is provided with a plurality of
spacedly aligned apertures 69 located along the portion of the
nozzle immediately adjacent the floor 71 of container 17. In this
manner, the flow of solution is directed toward the floor of the
container to assure a substantially stable surface for the
solution. As illustrated, drain member 25 serves to maintain the
desired level of the solution within the container. There is also
provided an overflow means consisting of adjacently positioned
overflow portions 73 and 73' respectively. When the solution
attains the desired level as established by drain member 25, the
excessive solution will overflow into drain member 25 and down into
collective reservoir 31 where it is then recirculated through
recirculation means 33 illustrated in FIG. 1. Should the level as
established by drain member 25 be such that quantities of the
solution will overlfow into overflow portions 73 and 73', this
solution will thereby exit these portions via established openings
in the bottoms of these portions. The solution will then return to
reservoir 31 and be recirculated.
The rinse solution is supplied to the rinse portion of container 17
through pipe 75 where it exits into central reservoir 77. The level
within reservoir 77 is established simply by the upper surfaces of
baffle members 79 located within rinse portion 61. The rinse
solution simply overflows from central cavity 77 into adjoining
overflow reservoirs 81 and 81' respectively whereupon it exits
through designated openings 83 located in the bottom of the
reservoirs. The rinse solution is then recirculated by a
recirculation means 85 illustrated in FIG. 1 as comprising a filter
member 87 and a pump 89. In the present embodiment, the primary
function of recirculation means 85 is to recover gold from any
excess solution still present on the articles as they emerge from
the plating area. This is accomplished by utilizing an ion exchange
resin within filter member 87 which will attract gold particles
from any solution passing therethrough. This resin is changed
periodically and the gold recovered. A secondary purpose for
rinsing each article is of course to clean the article prior to its
removal from the apparatus. Thus, it can be seen that a
continuously replenished supply of rinse solution is provided for
rinsing area 61. To assure that a mixing between the electrolyte
solution and the rinse solution never occurs within container 17, a
separation baffle member 91 is provided in the manner
indicated.
With reference to FIG. 4, the means for controlling the rate of
travel of articles 27 within track member 11 is illustrated as
comprising a rotating disc member 19 which rotates in the direction
indicated. Positioned within rotating disc member 19 are a
plurality of notch portions 93 which upon rotation of the member 19
are each adapted for engaging one of the articles 27 in the manner
indicated and removing this article from track member 11. The
article is then rotated to a drop station 95 which is shown to
comprise a collection chute 97 having a substantially upright
backstop member 99 affixed thereto. When rotating disc 19 moves one
of the articles to station 95, the article is removed from the
corresponding notch via an air supply means 101 which directs a
flow of air in the manner indicated to the station. In doing so,
each article is thereby forced into the collection chute 97 and
thereafter to an externally located collecting bin (not shown).
Rotating disc 19 is powered as illustrated in FIG. 1 by a drive
motor 103 joined to the rotating disc via a reduction gear drive
105. It can readily be understood, however, that several varieties
of drive means can be utilized and the illustrated embodiment is
not therefore meant in any way restrictive to the present
invention.
In FIG. 5 a typical example of one of the articles which can be
plated by the present invention is illustrated. As can be seen, the
preselected area indicated as 107 can receive a coating thereon of
precious metal by utilizing the coating apparatus and method of the
present invention. Utilization of the method and apparatus
described assures that only preselected portions 107 will be plated
on the article. Therefore, a substantial savings of electrolyte
solution results. As has been shown in the drawings, it can also be
seen that a method has been provided which includes an apparatus
which is readily adaptable for coating substantially large
quantities of articles in relatively short periods of time. In
referring back to FIG. 4, it can be seen that the rate of travel of
the articles along track 11 is readily controlled by the rate of
rotation of circulating disc 19. To increase the rate of travel,
the rotational rate of disc 19 in turn is also increased. To reduce
the rate of travel to thereby achieve a thicker coating on the
articles, the rate of rotation of disc 19 is simply reduced.
Thus, there has been shown an apparatus and a method for
electroplating preselected portions of relatively large quantities
of individual articles. The method and apparatus as described are
capable of providing this electrical deposition in a relatively
simple and inexpensive manner.
While there have been shown and described what is at present
considered the preferred embodiments of the invention, it will be
obvious to those skilled in the art that various changes and
modifications may be made therein without departing from the scope
of the invention as defined by the appended claims.
* * * * *