WO2002048430A2

WO2002048430A2 - Oxide-reducing agent composition, system and process

Info

Publication number: WO2002048430A2
Application number: PCT/US2001/042223
Authority: WO
Inventors: Morgan D. Tench; Dennis P. Anderson; John White
Original assignee: Innovative Technology Licensing, Llc.
Priority date: 2000-09-27
Filing date: 2001-09-20
Publication date: 2002-06-20
Also published as: WO2002048430A3

Abstract

An improved solution for reduction of oxide includes an oxide reduction agent and a halide or pseudo halide. The solution may be used to enhance a catholyte for an electrochemical system and process for regenerating reducing agents used in ancillary chemical or electrochemical processes such as restoring solderability in components having recalcitrant oxides. Such a system and process employs a cathode, an anode, and an electrolyte system that is separated by a semipermeable ionic barrier into the catholyte and an anolyte. The catholyte includes the reduced member of a redox couple, which can be regenerated electrochemically.

Description

APPLICATION FOR

ENHANCED OXIDE-REDUCING AGENT COMPOSITION, SYSTEM AND

PROCESS

1. Field of Invention.

The present invention relates to compositions, systems and processes for providing or improving the reduction of oxide on components. Preferred embodiments employ halide or pseudo halide solutions for fast oxide reductions. Further preferred embodiments relate to systems and processes, including ROSA™ systems and processes which employ such solutions, for example as an electrolyte.

2. Background of Invention.

Typical electronic assemblies are manufactured by attaching integrated circuits (ICs) to printed wiring assemblies (PWA) or printed circuit boards (PCBs). The attachments of the circuits are commonly made on an assembly line in which soldering processes are used to attach integrated circuits to PCBs or PWAs.

In typical mass soldering processes, which are used for attachment of integrated circuits, thousands of solder connections are often made within seconds to minimize costs and avoid thermal damage to circuit boards and sensitive components. Formation of reliable solder joints in such a short time period commonly requires either very good solderability of the circuit board and all of the component leads or the use of highly activated fluxes to facilitate the soldering attachment.

Ensuring good solderability has been an elusive goal of the electronics assembly industry. The industry has generally relied on activated rosin fluxes to remove oxides from the part surfaces and for preventing reoxidation during the soldering process. The soldering process itself, however, can introduce oxides on parts and can be detrimental to the solderability of components. Mass soldering processes often employ many processing steps involving thermal cycles, which tend to promote the oxidation of both circuit board and component connections and thereby reduce solderability of the assembly.

In addition, using processes such as reflow soldering and reheating of an assembly to provide multiple kinds of attachments can introduce additional thermal cycles during the assembly process, which can foster the creation of solderability limiting oxides. For example, one of the most popular industrial attachment methods for flip chips is the controlled collapsed chip connection (C4 Process). In the C4 process, solder bumps are created on a chip prior to the Attachment process. The process of creating the solder bumps involves a first heating process. Additionally, solder needs to be applied to the board prior to the attachment of the flip chip integrated circuit part, a second heating process. The flip chip is then attached to the circuit board by the process of reflow soldering — a third heating process. Subjecting items to be soldered to multiple thermal cycles can foster the creation of oxides, which hamper solderability.

Other processes can also unintentionally foster the creation of oxides that hamper solderability. For example, in surface mount machines, multifunction surface mount placement machines may attach chips through the process of applying heated heads to chips and circuit boards that have been pre-coated with solder. Such processing produces thermal cycling of nearby components and of the attachment traces which are located on the circuit board in close proximity to the heated head.

The electronic assembly industry has generally relied on activated rosin fluxes to remove oxides from parts or surfaces and to prevent reoxidation during the soldering process. Rosin fluxes, however, can form gummy residues at soldering temperatures that are difficult to remove and that can trap flux activators, which are aggressive chemicals that can cause corrosion. To avoid corrosion of circuit boards, it has been necessary to both limit the activity of the flux employed and to utilize ozone-depleting chloroflorocarbon (CFC) solvents for the removal of flux residues. However, by limiting the use of active flux, and limiting the use of CFC solvents, solderability is reduced. This reduced solderability has been a continuing concern of the electronics assembly industry.

The U.S. Government mandate to eliminate the use of CFC solvents by the year 1995 has spawned several alternatives to rosin fluxes, principally "no clean" and "water soluble" fluxes, but they are not free of environmental concern and are effective only under limited conditions. In the case of the use of "no clean" or "water soluble" fluxes, the rosin carrier, which also forms a film on parts that inhibits reoxidation during the soldering, is eliminated and the flux activity is reduced so that the flux residue can be left on the circuit board or removed by aqueous cleaning. These alternative fluxes function at least reasonably well, as long as the parts have good solderability to begin with and an inert or reducing atmosphere is maintained during the soldering operation. These fluxes, however represent a step backwards with respect to reliably forming solder joints.

To help increase reliability, a reduced oxide soldering activation (ROSA™) process that removes oxides from tin, lead and copper surfaces without the use of a flux has been developed. The ROSA™ process is environmentally benign, but provides soldering performance which is roughly equivalent to that obtainable with fully activated fluxes. The ROSA™ process can be used as part of the fluxless soldering process or to enhance the performance of no clean and water-soluble fluxes. Some boards and components accumulate recalcitrant oxides that are extremely difficult to remove and hamper solderability. These oxides may require treatment times with the ROSA™ process that are objectionably long. Accordingly ways of improving the ROSA™ process to handle recalcitrant fluxes have been sought.

The present invention relates to compositions, systems and methods which improve solderablitlity of electronic components and, in preferred embodiments, to restoring the quality of components and compositions used in the ROSA™ process. However, other embodiments may employ compositions made in accordance with embodiments of the invention in other processes for improving solderablitlity. Representative examples of methods of restoring solderability, to which embodiments of the present invention are applicable, include those described in U.S. Pat. No. 5,104,494 issued Apr. 14, 1992 and U.S. Pat. No. 5304297 issued February 26, 1993, the teachings of which are incorporated herein by reference. Metallic oxides, when present on solderable portions of electronic components, are detrimental to solderability of the components. In the process described by the aforementioned U.S. Pat. No. 5304297, a reducing agent is used to reduce the detrimental oxides to their metallic state, thereby restoring solderability of electronic components. The time necessary to remove recalcitrant oxides using the process of the 5304297 patent, as practiced in the ROSA™ process, can be objectionably long. The alternatives of employing active fluxes with aggressive chemicals or discarding the items which have recalcitrant oxides can also be unacceptable alternatives. Accordingly, there is therefore a need for a method of more quickly removing recalcitrant oxides from parts without employing aggressive fluxes. SUMMARY OF THE DISCLOSURE

To overcome limitations in the prior art described above and to overcome other limitations that will become apparent upon reading and understanding the present specification, the present specification discloses an improved system and process of restoring the solderability of electronic components.

Embodiments of the present invention include compositions, systems and methods for enhancing the removal or reduction of oxides from a component or part, for example, to improve the solderablitlity of an electronic component. Preferred embodiments may be used for restoring the quality of components and chemicals used in the Reduced Oxide Soldering Activation Process (ROSA™ ). ROSA™ is a process which regenerates reducing agents, such as those used in restoring the solderability of the components, while improving the solderability of components. In the process of enhanced solderability restoration, reducing agents are used to reduce detrimental metallic oxides found on the surfaces of solderable portions of electronic components. A ROSA™ process is described in U.S. Patents 5,104,494 and 5,304,297.

Preferred embodiments of the present invention employ an enhancing agent having a halide or pseudohalide, cyanide or thio-cyanide, which is particularly effective in removing recalcitrant oxides. System and process embodiments for regenerating reducing agents may be configured and operated in accordance with the ROSA™ process to provide an enhanced ROSA™ process and system. An enhanced ROSA™ process and system includes a cathode, an inert anode, a catholyte, an anolyte, a semipermeable ionic barrier and an enhancing agent in the catholyte. The enhancing agent reduces the time necessary to restore solderability and also removes oxides which prove difficult or time consuming for the unenhanced ROSA™ process to remove. These and other advantages and novel features which characterize embodiments of the invention are particularly pointed out in the included claims. For additional understanding and clarification of the invention, its advantages and variations, reference should be made to the accompanying drawings and descriptive matter, which illustrate and describe specific examples of embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present invention and for further advantages thereof, the following detailed description of exemplary embodiments of the invention makes reference to the accompanying drawings.

FIG. 1 is a schematic, cross-sectional view of a ROSA™ reducing agent regeneration system as may be used in an improved process of restoring solderability of electronic components.

FIG. 2 is an exemplary apparatus as may be used with a sequential electrochemical reduction analysis (SERA™) method for nondestructively accessing solderability of printed wiring boards and component leads.

FIG. 3 is a graph of charge density versus electrode potential for four different parts A, B, C and D which have had various exposures to the ROSA™ process for enhancing solderability.

FIG. 4 is a SERA™ graph for a part before and after exposure to the ROSA™ process for increasing solderability of components.

FIG. 5 is a SERA™ graph of charge density versus electrode potential comparing the solderability of parts as received versus treatment with the ROSA™ process with no halide present versus treatment in the ROSA™ process in the presence of the halide chloride. FIG. 6 is a expanded graph of charged density versus electrode potential for parts as received versus parts which have been treated for five minutes in a ROSA™ process with chloride augmentation.

FIG. 7 is a charged density versus electrode potential graph for parts as received, treated in the one minute ROSA™ process without a halide, treated in a one minute ROSA™ process with a fluorine halide, treated in a one minute ROSA™ process with a bromine halide present, treated in a one minute ROSA™ process with a chlorin halide present and treated in a one minute ROSA™ process with an iodine halide present.

DESCRIPTION OF THE DISCLOSURE

Accompanying drawings refer to illustrated descriptions of exemplary embodiments of the present invention. It is to be understood that many other non- illustrated embodiments may be practiced consistent with the present disclosure as various implementations may be devised and structural changes made without departing from the scope and spirit of the invention disclosed herein.

Embodiments of the invention relate to solutions, systems and processes for enhancing the removal or reduction of oxides from a component or part. While the removal or reduction of oxides may be beneficial for a variety of purposes within the scope of the invention, preferred embodiments may be employed to remove or reduce oxides for the purpose of improving the fusion bonding characteristics of a component or part. For example, the removal or reduction of oxides in accordance with preferred embodiments of the invention may be employed to improve the solderablility of an electrical component or part. For purposes of simplifying the present description, various embodiments are described below in the context of improving the solderability of an electrical component or part. However, those skilled in the art will understand that further embodiments of the invention may be employed in the context of improving the ability of a component or part to be welded, brazed or otherwise fusion bonded to other components or parts, as well as other contexts which benefit from the removal or reduction of oxide from a component or part.

In one aspect, embodiments of the present invention relate to an enhancing agent having a halide or pseudohalide, such as cyanide or thio-cyanide, which is particularly effective in removing recalcitrant oxides. Thus, according to one preferred embodiment, enhanced compositions for removing or reducing recalcitrant oxides include an oxide reducing agent and a halide or pseudohalide.

Enhanced compositions according to embodiments of the invention may be employed in various processes for removing oxides from components or parts including, but not limited to, dipping processes in which a component or part to which a soldering function will be performed, is dipped, immersed or otherwise placed in direct contact with a solution of the enhanced composition, for example, prior to a fusion bonding process, to improve the bondability of the component. However, preferred embodiments employ such enhanced compositions in an electrolyte solution for an electrochemical system and process for removing or reducing oxides from components or parts.

For example, embodiments may be employed with or relate to an enhanced ROSA™ process or system, where an enhancing agent comprising a halide or pseudohalide is included in the catholyte of the ROSA™ process or system. FIG. 1 is an illustration of the generalized ROSA™ process. In the ROSA™ process, metallic oxides that interfere with solder wetting and hence solderability are reduced back to the metal state by a highly reduced aqueous acidic solution containing vanadous ions. Excellent wetting (enhanced solderability) may be accomplished by the process since substantial oxide removal can be accomplished prior to soldering.

FIG. 1 is a schematic representation of an example ROSA™ process and system. The system includes an electrochemical regeneration cell which is divided into two compartments, 101 and 103, for the catholyte and anolyte, respectively. The two compartments are separated by a microporous glass sheet 105 that acts as a semi- permeable ionic barrier, inhibiting migration of vanadium atoms from the catholyte to the anolyte. An oxide coated part 107, such as an electrical component to be soldered, is immersed in the catholyte compartment 101.

The operation of the ROSA™ process is analogous to the charging and discharging of a battery. During charging, N³⁺ ions are reduced to V²⁺ ions, which oxidize back to N³⁺ ions at the part 107, to yield the energy and electrons needed to reduce metal oxides on the part 107 to free metal. The currents involved in the ROSA™ process are small (generally in the low mA range), are localized at the surface in an electroless loop and do not pass through the part itself.

As a representative example, the half cell and net reactions involved in the electroless reduction of Sn0₂ by vanadous (V²⁺) ions are:

4V²⁺-»4V³⁺ +4e^" (anodic reaction)

SnQ₂+4H⁺+4e →Sn+2H2θ (cathodic reaction)

Snθ2+4N²⁺ +4H⁺→Sn+4N³⁺ +2H₂0 (net electroless reaction)

Electro chemical regeneration of the V²⁺ reducing agent involves. 4V^{3 +} + 4e^"-»4V²⁺ (cathode reaction)

2H₂O- 4H⁺ +O₂+4e (anode reaction) 4N³⁺ +2H₂O- 4N²⁺ +4H⁺ +O₂ (net regeneration reaction)

The overall reaction is: SnO₂-»Sn+O₂

Thus, the process is a closed loop process in which electricity is used to reduce the oxide present on the parts to metal and oxygen gas, and no chemicals are generated or consumed. Protons are consumed during the oxide reduction, but are actually catalysts overall since they are generated in equivalent amounts at the anode.

As described in more detail below, the oxide reduction characteristics of the ROSA™ process can be enhanced through the addition of halide ions to the catholyte solution. Such ions can be incorporated into the catholyte solution through the dissolution of soluble compounds containing halides, for example KC1, ΝaBr, Lil, and ΝaF. Additionally pseudo halide compounds containing cyanide and thiocyanide, may also be used to enhance the operation of the ROSA™ process.

Although the ROSA™ process is highly effective for increasing solderability of electronic components and boards, an actual quantification of solderability can be difficult. A recently developed sequential electrochemical reduction analysis (SERA™) method permits the nondestructive assessment of solderability loss associated with surface oxides and metal. Such a solderability assessment tool is described in the Journal Of Applied Electrochemistry. Volume 24, 1994 Edition. The method of solderability assessment has been termed SERA™ (sequential electrochemical reduction analysis). This method of solderability assessment is described in an article "Solderability Assessment Via Sequential Electrochemical Reduction Analysis" and may be found in the aforementioned Journal Of Applied Electrochemistry. Volume 24, 1994. The SERA™, method utilizes "chronopotentiometry," wherein a constant current is applied to a part in a solution and the resulting electro potential produced is observed.

FIG. 2 is a graphic illustration of an apparatus 201 which may be used in solderability assessment using the SERA™ method. In the SERA™ method, the part to be analyzed, a wire in the illustrated example, is brought in contact with an electrolyte 203 chosen to facilitate reduction and minimize chemical dissolution of the oxides of interest. A constant cathodic current is applied between the wire under test 205 and an inert counter electrode 207, which may be, for example, platinum or stainless steel or other non reactive conductive material, and the cathodic potential is monitored as a function of time relative to a reference electrode 209.

Utilizing this three electrode arrangement, potential of the cathode 205 can be monitored without concern about changes in the anode potential 207. The applied current is chosen to avoid excessive polarization of the cathode 205 and is typically very small, for example, less than 100 microramps per square centimeter, so that the voltage drop in the bulk electrolyte, which must be de-aerated, is negligible. For example, the electrolyte can be de-aerated via purging within an inner gas. Without de-aeration electrochemical reduction of oxygen would otherwise interfere with the analysis. To inhibit oxygen generated at the anode, by electrolysis of water, from reaching the cathode during the measurement, the anode can be placed far from the cathode or a porous glass frit 211 may be used to form a diffusion barrier.

FIG. 3 is a graph, which illustrates an observed series of SERA™ curves. Four comparable wire specimens were treated with the ROSA™ process for various times in pH 0.5 vanadous sulfate solution (0.8M). For comparison purposes, wire specimen A was not treated within the ROSA™ process, for increasing solderability, and yielded a curve 301. Wire specimen B was treated for five seconds in the test ROSA™ process and yielded a curve 303. Wire specimen C was treated for ten seconds in the test ROSA™ process and yielded a curve 305. Wire specimen D was treated for thirty seconds in the test ROSA™ process and yielded a curve 307.

Wire A was not treated by the ROSA™ process and exhibited the least solderability as demonstrated in graph 301. Since it is known that longer exposure in the ROSA™ process results in greater solderability and further reduced oxides, wire A will depict the least solderable wire followed by wire B, which was exposed for 5 seconds to the ROSA™ process. The third least solderable is wire C, which was exposed to 10 seconds of the ROSA™ process. The most solderable specimen is wire D exposed to the ROSA™ process for 30 seconds. Graph 301 illustrates that part A took the longest time to reach a -1.25 volt electrode potential on the vertical axis 309 of the graph and had the shallowest slope. Test wire D, represented by curve 307, illustrates the most solderable wire, having been treated by the ROSA™ process for thirty seconds and reaching an electrode potential of - 1.25 volts first and having the steepest slope.

FIG. 4 represents another charge density versus electrode potential graph, which had been measured before and after a ROSA™ process exposure. The part before treatment by the ROSA™ process exhibits a lower solderability, as depicted by curve 401. After treatment, the same part exhibits a heightened solderability, as depicted by curve 403. The graphs in FIG. 3 and FIG. 4 are examples of the types of results that are obtained using the ROSA™ process. The ROSA™ process significantly improves solderability, which is reflected by the SERA™ curves that exhibit a steeper slope and more rapid decline in electro potential, representing the increased solderability. Although the ROSA™ process results in a significant improvement in solderability, as measured and verified in SERA™ measurements, some parts exhibit a greater reluctance to return to solderability than other parts. These parts can then be subject to extended time ROSA™ processing in order to return them to satisfactory solderability. Although experimental results indicate extended ROSA™ processing will eventually restore solderability if applied for a long enough period, methods to increase the effectiveness of the ROSA™ process and to decrease the requisite exposure time have been sought. One method of improving the speed and efficacy of the ROSA™ process is to add a soluble compound containing a halide or a pseudo halide to the ROSA™ catholyte 101 solution. Halide concentrations of 0.1 Molarity (M) have been shown to enhance solderability, when added to the catholyte solution. However it is believed that ranges from as low as 0.01M would produce significant benefit. It is also believed that concentrations greater than 0.1M would be effective. Concentrations greater than 0.5M, while effective from an increased solderability view point, may be undesirable because of the possibility of increased halide residues that could lead to circuitry corrosion problems.

Another consideration of higher concentrations is the enhanced migration of halide ions across the cell separator to the anode where they may be oxidized to appreciable amounts of undesirable species, for example chlorine gas in the case of the chloride ion. The addition of halide ions within the catholyte solution greatly increases the effectiveness of the ROSA™ process, which may be of particular importance when electronic components with recalcitrant oxides that are hard to reduce are present. The presence of an ionic halide in the solution can greatly improve the speed at which oxides are reduced.

FIG. 5 is an illustration of the effect of adding calcium chloride to the electrolyte solution in a ROSA™ process. The halide ion must be present in the catholyte 101 solution. FIG. 5 illustrates SERA™ curves for a one minute ROSA™ process with similar parts. As can be seen from FIG. 5, the untreated (as received) part is represented by the SERA™ curve 501 as the least solderable of the parts tested. A similar part chosen from a group of recalcitrant oxide parts shows an increased solderability in SERA™ curve 503 when the ROSA™ process is applied with no halide. However, when potassium chloride, a highly soluble compound, is added to the ROSA™ catholyte in a concentration of .1M, an increased solderability results, as illustrated by curve 505. From experimental observations, it appears that a effective amount of potassium chloride when added to the ROSA™ solution electrolyte, will improve the solderability of a part at a much faster rate than the ROSA™ process without the potassium chloride. The concentration of potassium chloride to produce the curve in Fig. 5 was about .1M. However, it is believed that concentrations as low as .01M can produce beneficial results in some contexts and as high as .5M in other contexts. The optimum ranges of concentration for potassium chloride in particular and other halides or pseudo halide additions in general must await further effort. Concentrations may even depend on the type of part, the type of oxide, and the process which cause the formulation of the oxide in order to produce optimum solderability. The effectiveness, however, of the addition of the halide such as potassium chloride is not in question. The increased solderability is graphically illustrated in the SERA™ curves of FIG. 6. The graph of FIG. 6 illustrates the difference between a typical recalcitrant oxide part as received, i.e., the graphic line 601 and a similar recalcitrant part in which potassium chloride has been added to the ROSA™ catholyte, to form a solution of 0.1M concentration, and processed for five minutes. The part processed for five minutes in the ROSA™ halide enhanced electrolyte (shown by line 603) is markedly more solderable than the part as received (shown by line 601). FIG. 7 is an illustration of comparable SERA™ curves for similarly recalcitrant parts for a one minute exposure to ROSA™ processing containing various halides at 0.1M concentration, for ROSA™ processing without halides and for parts with no treatment by a ROSA™ process. It should be noted that the curves in FIG. 7 are representative of a number of parts chosen from a batch of recalcitrant oxide parts and each curve is formed from a different part. Curve 701 is a SERA™ curve assessing the solderability of a recalcitrant oxide part as received. Curve 703 is a graph illustrating the processing of a part in a one-minute ROSA™ process with no halide. The part subjected to the ROSA™ process exhibits greater solderability than the part as received, as shown by SERA™ curve 703, compared to SERA™ curve 701. Curve 703 exhibits a steeper average slope, as well as attaining a -1.2 volt potential more quickly. Curve 705 represents a part processed for one minute with a ROSA™ solution in a ROSA™ process in which a fluoride halide in a concentration of about 0.1M was present in the catholyte. As shown, the solderability produced as represented by curve 705 is superior to the solderability produced by the same one-minute process with a ROSA™ solution with no halide 703. Curve 707 is a typical curve of a one-minute ROSA™ process on the same type recalcitrant oxide part with the addition of a bromine halide in a concentration of about 0.1M. As can be seen from curve 707, one minute processing of the part with a ROSA™ solution containing a bromine halide results in superior solderability over a one-minute process with a fluorine halide curve 705, or with a ROSA™ solution with no halide, graph line 703. Curve 709 illustrates a one-minute ROSA™ processing in which a chlorine halide is present in the electrolyte in a concentration of about 0.1M. SERA™ curve 709 illustrates that an increase in solderability is detected over the addition of a bromine halide 707, or fluorine halide 705, or no halide 703 ROSA™ processing. Curve 711 illustrates a typical one-minute ROSA™ processing with an iodine halide in solution in a concentration of about 0.1M. The iodine halide addition to the ROSA™ solution for a one minute processing results in a typical curve 711 which illustrates a superior resulting solderability than any of the other halides or processing with the ROSA™ solution with no halide 703. Although the addition of an iodine halide appears to give the best solderability improvement, in the above one-minute ROSA™ processing experiment, it may be more desirable to use a chlorine halide. Chlorine may be a more desirable halide because any chlorine effluent given off by the process will result in a chlorine gas which can be easily vented, whereas any iodine given off by an iodine halide, may result in a solid retained within the ROSA™ solution. Experimental results confirm that the efficaciousness of the ROSA™ process is increased, especially in the case of recalcitrant oxides by the addition of halide solutions within the catholyte bath of the ROSA™ solution. Accordingly, preferred embodiments of the invention relate to halide or pseudo halide solutions for fast oxide reductions. Further preferred embodiments relate systems and processes, including ROSA™ systems and processes which employ such solutions, for example as an electrolyte. Although the present invention has been described with respect to specific embodiments thereof, various changes and modifications can be carried out by those skilled in the art without departing from the scope of the invention. For example, while embodiments are described above with relation to the reduction of oxide to improve solderability, further embodiments relate to the reduction of oxide in other contexts, such as to improve the operation and characteristics of other fusion bonding processes, including, but not limited to, welding or brazing. Therefore, it is intended that the present invention encompass such changes and modifications as fall within the scope of the claims.

Claims

CLAIMSWhat is claimed is:

1. A reducing agent system, comprising: a vessel having a first compartment; and a catholyte solution contained in the first compartment, said catholyte including a reducing agent subject to being oxidized in the course of a chemical or electrochemical process and an ion selected from the group consisting of a halide ion and a pseudo halide ion.

2. The system of claim 1, wherein the halide ion is selected from the group consisting of a fluorine ion, a chlorine ion, a bromine ion, and a iodine ion.

3. The system of claim 1, wherein the pseudo-halide ion is selected from the group consisting of a cyanide ion and a thio-cyanide ion

4. The system of claim 1, wherein the reducing agent comprises a reduced member of a redox couple selected from the group of materials consisting of vanadium, chromium, and europium ions.

5. The system of claim 1, wherein said vessel has a second compartment containing an anolyte and wherein said catholyte comprises a sulfate solution and said anolyte comprises a sulfuric acid (H₂SO₄) solution.

6. A system as recited in claim 1, wherein the vessel comprises a second compartment, the system further comprising: a cathode placed in said catholyte, said cathode comprising a material having a high hydrogen overvoltage; an anolyte solution contained in the second compartment; an inert anode placed in said anolyte; and a semi- permeable ionic barrier separating said first and second compartments, said ionic barrier allowing migration of protons from said anolyte to said catholyte but opposing migration and diffusion of cations from said catholyte to said anolyte, wherein said cathode electrochemically regenerates the reducing agent after it has been oxidized.

7. The system of claim 6, wherein said cathode comprises a material selected from the group of materials consisting of lead, mercury, indium, antimony, tantalum, bismuth, arsenic, carbon, cadmium, thallium, tin, and alloys thereof.

8. The system of claim 6, wherein said catholyte comprises vanadium sulfate and sulfuric acid, said cathode comprises a material selected from the group of materials consisting of lead and lead alloys, and said ionic barrier comprises a microporous glass separator.

9. A method of reducing oxides from a component, comprising: providing a catholyte solution in a first compartment of a vessel, said catholyte including a reducing agent subject to being oxidized to an oxidized state in the course of a chemical or electrochemical process and an ion selected from the group consisting of a fluorine ion, a chlorine ion, a bromine ion, an iodine ion, a cyanide ion and a thio- cyanide ion; and placing at least a portion of a component in contact with said catholyte.

10. The method of claim 9, wherein providing a catholyte comprises providing a catholyte including a redox couple having a reduced member comprising the reducing agent and an oxidized member comprising said oxidized state.

11. The method of claim 9, wherein providing said catholyte comprises providing a solution of vanadium sulfate and sulfuric acid.

12. The method of claim 9, further comprising: placing a cathode in said catholyte, said cathode comprising a material having a high hydrogen overvoltage; providing an anolyte solution in a second compartment of the vessel; placing an inert anode in said anolyte; and separating said first and second compartments with a semipermeable ionic barrier, said ionic barrier allowing migration of protons from said anolyte to said catholyte but opposing migration and diffusion of cations from said catholyte to said anolyte; and electrochemically regenerating the reducing agent from said oxidized state at said cathode.

13. The method of claim 12, wherein placing said cathode in said catholyte further comprises selecting said cathode from the group of materials consisting of lead, mercury, indium, antimony, tantalum, bismuth, arsenic, carbon, cadmium, thallium, tin, and alloys thereof.

14. The method of claim 12, wherein providing said anolyte comprises providing a sulfuric acid (H₂SO ) solution.

15. The method of claim 12, wherein separating said first and second compartments with a semipermeable ionic barrier comprises separating said compartments with a microporous glass separator.

16. A composition for reducing oxide on a component, the solution comprising an oxide reducing agent and an ion selected from the group consisting of a fluorine ion, a chlorine ion, a bromine ion, an iodine ion, a cyanide ion and a thio-cyanide ion.

17. A composition as recited in claim 16, wherein the reducing agent comprises a reduced member of a redox couple selected from the group of materials consisting of vanadium, chromium, and europium ions.

18. A composition for reducing oxide on a component, the solution comprising an oxide reducing agent and a halide or pseudo halide.

19. A composition as recited in claim 18, wherein the reducing agent comprises a reduced member of a redox couple selected from the group of materials consisting of vanadium, chromium, and europium ions.