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  Apparatus for electroplating an articleUSPTO Application #: 20070215457Title: Apparatus for electroplating an article Abstract: An apparatus for electroplating an article, such as a printed circuit board, includes a tank filled with electrolytic solution, a clamp for retaining the article fixed in place within the solution and a movable roller assembly disposed within the solution. The roller assembly includes a pair of vertically disposed, parallel rollers that are rotatably coupled to a rigid frame, with one roller preferably being spring biased towards the other roller. In use, the application of electrical current causes metal ions present in the solution to plate out on the article. To promote greater plating within through-holes or other similar surface depressions in the article, the roller assembly is linearly displaced by a motor-driven linkage so that the pair of rollers squeegee opposing surfaces of the article. (end of abstract) Agent: Kriegsman & Kriegsman - Southborough, MA, US Inventor: Steven P. Glassman USPTO Applicaton #: 20070215457 - Class: 204194000 (USPTO) Related Patent Categories: Chemistry: Electrical And Wave Energy, Apparatus, Electrolytic The Patent Description & Claims data below is from USPTO Patent Application 20070215457. Brief Patent Description - Full Patent Description - Patent Application Claims
CROSS-REFERENCE TO RELATED APPLICATIONS [0001] The present application is a continuation-in-part of U.S. patent application Ser. No. 11/606,629, filed Nov. 30, 2006 which, in turn, is a continuation of U.S. patent application Ser. No. 10/856,505, filed Jun. 1, 2004, both of said applications being incorporated herein by reference. BACKGROUND OF THE INVENTION [0002] The present invention relates generally to electroplating equipment and more particularly to equipment used to electroplate articles which include holes and/or surface depressions. [0003] Electroplating is a well-known and widely used process which uses electrical current to deposit a thin layer of metal with some particular property (e.g., conductivity, abrasion and wear resistance, corrosion protection, lubricity, improvement of aesthetic qualities, etc.) onto an article that lacks said property. [0004] Specifically, in one well-known form of electroplating, electrodes are immersed in a tank filled with an electrolytic solution that serves to create a closed electrical circuit therebetween. One or more of the electrodes (i.e., the electrodes that are to be plated) serve as the cathode of the circuit and, as such, are connected to the negative terminal of an external direct current (DC) power supply, such as a battery or rectifier with variable voltage and amperage control. The remaining electrodes (i.e., the electrodes constructed of the particular metal to be plated onto the cathode) serve as the anode of the circuit and, as such, are connected to the positive terminal of the DC power supply. The supply of voltage to the closed circuit causes metal ions present in the electrolytic solution to lose their charge and plate out (i.e., accumulate, deposit) on the cathode. The anode serves to replenish the supply of metal ions in the electrolytic solution during the plating process. [0005] Electroplating is commonly utilized during the manufacture of printed circuit boards to deposit a conductive material, such as nickel or copper, onto a non-conductive substrate. Upon completion of the electroplating process, the conductive material deposited on the substrate is etched in a particular pattern to create a number of conductive pathways, or traces. In this manner, the conductive pathways can be used to electrically connect components mounted on the circuit board. [0006] Circuit board electroplating is commonly performed in the following manner. Each circuit board to be plated is attached to a corresponding conductive frame which is, in turn, connected to the negative terminal of the power supply. Each frame is then mounted onto an enlarged tank filled with an electrolytic solution so that the circuit board is completely immersed within the solution. It should be noted that each frame is traditionally mounted onto the tank so that the circuit board extends in a substantially vertical position, thereby enabling for (1) a greater quantity circuit boards to be disposed in tank at the same time and (2) easier access to each circuit board within the tank. With the circuit board immersed within the solution, one or more pairs of metallic members (e.g., rods or blocks constructed of copper) are connected to the positive terminal of the power supply and are similarly immersed within the electrolytic solution on opposite sides of the circuit board. Accordingly, with voltage being supplied from the power source, each circuit board (and its corresponding frame) serves as the cathode of the closed circuit and each metallic member serves as the anode of the closed circuit. In this manner, it is to be understood that the surfaces of the circuit board that are exposed to metal ions in the electrolytic solution become plated with conductive material. It should be noted that metal ions accumulate on the exposed portions of the circuit board until either (1) the supply of voltage to the circuit is withdrawn or (2) metal ions no longer remain available in the electrolytic solution. [0007] As can be appreciated, printed circuit boards are commonly provided with a number of holes and/or surface depressions. For example, many printed circuit boards are provided with a large quantity of through-holes that extend transversely through the circuit board substrate, with the barrel of each through-hole being plated with a conductive material. In this manner, components can be electrically connected to the printed circuit board by (1) positioning each lead for the component within a corresponding through-hole in the circuit board and (2) filling each through-hole with a conductive material, such as solder. [0008] The above-described circuit board electroplating process is commonly used to conductively plate the barrel of through-holes that extend transversely through the circuit board substrate. However, it has been found that the effectiveness of electroplating the barrel of through-holes is compromised due to (1) the relatively small cross-sectional diameter of each hole and (2) the limited flow of metal ions in the electrolytic solution through each through-hole since the longitudinal axis of each hole is horizontally disposed. [0009] Various techniques have been incorporated into the traditional electroplating process to stimulate the flow of electrolytic solution and thereby increase the amount of metal plating on an article. [0010] As an example, it is well-known in the art to periodically agitate the electrolytic solution to promote greater amounts metal ion deposition onto an article. Agitation of the electrolytic solution is often accomplished by displacing one or more air sparger units within the solution. Each air sparger unit is commonly constructed using a 0.25-0.50 inch PVC pipe that includes a plurality of spaced apart holes. In use, clean air (e.g., nitrogen) is pumped through the pipe at high pressure and, in turn, exits through the spaced apart holes in the pipe as bubbles. The creation of these bubbles serves to help agitate the solution and break hydrogen gas bubbles that may collect around the board. [0011] As another example, it is well-known to move and/or vibrate the article to be plated in order to promote greater amounts of metal ion deposition. In U.S. Pat. No. 5,167,779 to H. J. Henig, there is disclosed a process and apparatus for obtaining an intensive and continuous exchange of electrolyte on the surfaces of workpieces subjected to chemical or electrolytical treatments wherein the exchange is achieved by subjecting the workpieces to strong pulsating oscillations of frequency of at least 1 Hz and of an amplitude of less than 10 mm, when immersed in the electrolyte. The vibrations are transmitted from an oscillation generator mounted on a workpiece carrier, such as a rack or a rotating dipping drum. These high frequency low amplitude oscillations may be combined with low frequency, relatively long oscillations occurring simultaneously. The oscillation generator is arranged on the individual transportable workpiece carriers. The workpieces may be boards for printed circuits having through holes or a pourable mass of parts. [0012] Although well-known in the art, the techniques described above for improving metal ion deposition have been found to introduce a number of notable drawbacks. [0013] As a first drawback, the above-described techniques have been found to be inadequate when used to plate the barrel of circuit board through-holes which extend axially in a horizontal manner. Specifically, the above-described electroplating techniques produce a deposition layer on the barrel of each through-hole that is of limited thickness which, in turn, can jeopardize the quality of the electrical connection established between electrical components and the printed circuit board on which the components are mounted, which is highly undesirable. Consequently, these types of electroplating processes are often significantly extended until the deposition layer in each though-holes is adequate. However, this results in (1) a substantial increase in the deposition layer on the top and bottom surfaces of the circuit board, (2) an increase in manufacturing costs, and (3) a greater time requirement, all of which are highly undesirable. [0014] As a second drawback, it has been found that the use of certain agitation units to improve the flow of electrolytic solution are potentially harmful to the environment, which is highly undesirable. SUMMARY OF THE INVENTION [0015] It is an object of the present invention to provide a new and improved apparatus for electroplating an article, such as a printed circuit board, the article including enlarged, flattened top and bottom surfaces and one or more through-holes extending transversely therethrough. [0016] It another object of the present invention to provide an apparatus as described above which adequately plates the barrel of each through-hole in the article without significantly increasing the amount of deposition on each of the top and bottom surfaces. [0017] It is yet another object of the present invention to provide an apparatus as described above which limits the risk of potentially harmful environmental conditions. [0018] It is still another object of the present invention to provide an apparatus as described above which has a limited number of parts, which is quick and easy to use and which is inexpensive to manufacture. [0019] Accordingly, there is provided an apparatus for electroplating an article, the article including substantially flat front and rear surfaces, the apparatus comprising (a) a tank shaped to define an interior cavity; (b) a clamp adapted to fixedly support the article within the interior cavity of the tank; (c) a roller assembly adapted to squeegee the front and rear surfaces of the article; and (d) a linkage for linearly displacing the roller assembly within the interior cavity of the tank. [0020] Various other features and advantages will appear from the description to follow. In the description, reference is made to the accompanying drawings which form a part thereof, and in which is shown by way of illustration, a specific embodiment for practicing the invention. This embodiment will be described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized and that structural changes may be made without departing from the scope of the invention. The following detailed description is therefore, not to be taken in a limiting sense, and the scope of the present invention is best defined by the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS Continue reading... Full patent description for Apparatus for electroplating an article Brief Patent Description - Full Patent Description - Patent Application Claims Click on the above for other options relating to this Apparatus for electroplating an article patent application. ###  How KEYWORD MONITOR works... a FREE service from FreshPatents1. Sign up (takes 30 seconds). 2. Fill in the keywords to be monitored. 3. Each week you receive an email with patent applications related to your keywords. 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