TWI623653B - Treatment for electroplating racks to avoid rack metallization - Google Patents

Abstract

The present invention describes a plating rack for supporting a non-conductive substrate in an electrodeposition process. The plating rack is coated with a non-conductive material such as a PVC plastisol. The plating rack is treated with a non-aqueous solution containing a metallization inhibitor prior to the electrodeposition process to inhibit the pylon from being plated when an etchant-free etchant is used.

Description

Plating rack and plating rack for avoiding metallization of the rack

The present invention is primarily directed to a method of treating a plating rack for supporting a non-conductive substrate in a metallization step.

Many methods have been used over the years to aid in the deposition of electrodeposited metals on plastic substrates. Such methods generally include the following steps: 1) etching the plastic in a suitable etching solution to roughen and wet the plastic surface to facilitate good adhesion of the subsequently applied deposit; 2) using a metal capable of initiating autocatalytic coating a colloidal or ionic solution of a metal (usually palladium) deposited by a coating such as copper or nickel to activate the surface of the plastic; 3) a thin layer of self-catalyzed coated metal; and 4) a metallized plastic base Electrodeposition of the metal is performed on the material.

In general, a layer of copper, nickel and/or chrome is applied to produce a finished product.

The most widely used plastic substrates are acrylonitrile/butadiene/styrene copolymer (ABS) or ABS (ABS/PC) blended with polycarbonate. These materials can be easily formed into components by injection molding. ABS contains a fairly hard acrylonitrile/butadiene/styrene copolymer matrix. And butadiene polymerizes to form a separate phase. This softer polybutadiene phase (containing double bonds in the polymer backbone) can be easily etched using a variety of different techniques.

Traditionally, etching has been carried out using a mixture of chromic acid and sulfuric acid at high temperatures. Chromic acid is capable of dissolving the polybutadiene phase of ABS by the oxidation of double bonds in the polybutadiene polymer backbone, which has proven to be quite reliable and effective for a wide range of ABS and ABS/PC plastics. However, due to the toxicity and carcinogenic nature of chromic acid, it has been increasingly regulated in use. Based on this, there is considerable research on other ways of etching ABS plastics, and there are some ways to achieve this.

For example, acidic permanganate is capable of oxidizing double bonds in polybutadiene. Then, by further oxidation with periodate ions, the effect of chain scission can be achieved. Ozone can also oxidize polybutadiene. However, ozone is quite dangerous to use and highly toxic. Similarly, sulfur trioxide can be used to etch ABS, but on typical plating lines, etching cannot be successfully achieved. Other examples of techniques for etching ABS plastics can be found in U.S. Patent Publication No. 2005/0199587 to Bengston, U.S. Patent Publication No. 2009/0092,757 to Sa., et al., and U.S. Patent No. 5,160,600 to Gordhanbai et al. The contents of this article are fully incorporated herein by reference.

Recently, it has been found that ABS and ABS/PC plastics can be etched in a solution containing manganese (III) ions in strong sulfuric acid, as described in U.S. Patent Publication No. 2013/0186774 to Pearson et al. This article refers to.

To plate the plastic component, it is attached to a plating rack that carries current to sensitize and metallize the plastic component. These pylons are typically at least partially coated with a non-conductive material to prevent the pylon from being completely covered by metal during the electroplating process, and the most common pylon coating is a PVC plastisol. The use of chromic acid in the etching stage prior to activation effectively modifies the surface of the plastisol coating to resist metallization after being coated with a palladium activator (typically a colloid of palladium and tin). When chromic acid is replaced by other etching techniques (for example, using a process containing permanganate or manganese (III)), the plastisol coating of the plating rack becomes coated with an activator, and then becomes in the electroless plating stage. It is coated with a layer of nickel or copper. Therefore, the main problem faced by all currently known methods of not using chromic acid is that the pylon coating is easily plated in the subsequent electroless plating stage. This phenomenon is known as "hanger plating" and this is a major problem with any form of chromium-free etching technology.

One of the objects of the present invention is to suppress the galvanic plating in the electroplated non-conductive substrate process.

Another object of the present invention is to inhibit pylon plating in the electroplated non-conductive substrate process wherein the non-conductive substrate is etched using a chromium-free etchant.

Still another object of the present invention is to provide a method of processing a plating rack, wherein the rack is used to support a non-conductive substrate in an electroplating process.

To this end, in one embodiment, the present invention is primarily directed to a plating rack for supporting a non-conductive substrate in an electrodeposition process, Wherein the plating rack is at least partially coated with a non-conductive material; and wherein the plating rack is treated with a non-aqueous solution containing a metallization inhibitor.

In another embodiment, the present invention is generally directed to a method of treating a plating rack for supporting a non-conductive substrate in an electrodeposition process, wherein the plating rack is at least partially coated with a non-conductive material, the method include: The plating rack is brought into contact with a non-aqueous solution containing a metallization inhibitor.

The present invention can be used to treat plating hangers for the purpose of supporting a non-conductive substrate during the metallization step. The methods described herein are effective in activating etched plastics that are not etched using chromic acid, while avoiding the common problems of pylon "plating" that occurs when using a chromic acid-free etchant for initial roughening of the plastic. In addition, the present invention relates primarily to the catalysis and subsequent metallization of plastics such as ABS and ABS/PC, which have been etched in a process solution containing no chromic acid and in an at least partially coated pylon There is no problem with "plating".

In a preferred embodiment, the method generally comprises the steps of: 1) immersing a pylon partially coated with a non-conductive material into a solution containing a metallization inhibitor; 2) rinsing the pylon and drying it; 3) Mount the parts to be metallized on the hanger; 4) etching the plastic component mounted on the treated pylon in an etching solution containing no chromic acid (including, for example, a permanganate or manganese (III)-based etching solution); 5) Immerse the plating rack in a solution containing colloidal palladium/tin or ionic palladium to activate the surface of the plastic; 6) immerse the pylon in an accelerated process to remove protective tin oxide from the surface (if colloidal palladium/tin Activation) either by immersing the pylon in a reduction process to form palladium metal on the surface (if ionic palladium); 7) immersing the etched and activated part pylon into the metallization bath to nickel or copper Chemically deposited on the surface of the activated part; and 8) electroplated the part, typically copper, nickel and/or chromium.

Accordingly, in one embodiment, the present invention is generally directed to a plating rack for supporting a non-conductive substrate in an electrodeposition process, wherein the plating rack is at least partially coated with a non-conductive material; and wherein the plating The pylon is treated with a non-aqueous solution containing a metallization inhibitor.

As described herein, the plating rack is typically coated with a PVC plastisol or another non-conductive material.

The non-aqueous solution typically contains from about 5 grams per liter to about 40 grams per liter of metallization inhibitor, more preferably from about 15 grams per liter to about 25 grams per liter of metallization inhibitor, and most preferably about 10 grams per liter. Raise to about 20 grams per liter of metallization inhibitor.

The temperature of the non-aqueous solution is preferably maintained between about 25 ° C and about 75 ° C, and more preferably between about 35 ° C and about 65 ° C. During this time, the plating rack was immersed in a non-aqueous solution. In addition, the plating rack should be immersed in a non-aqueous solution for a time sufficient to treat the PVC plastisol-coated pylon to prevent the pylon from being plated. That is, the plating rack is preferably immersed in the non-aqueous solution for between about 1 minute and about 60 minutes, more preferably between about 2 minutes and about 30 minutes.

The inventors have discovered that metallization inhibitors that are substantially soluble in aqueous media are not suitable for the processes described herein because they are readily leached into subsequent process solutions and prevent parts from being Metalization. The metallization inhibitor is preferably at least substantially insoluble in the aqueous medium. Therefore, the solution containing the metallization inhibitor is a non-aqueous solution.

Suitable water-insoluble metallization inhibitors are generally organic compounds containing divalent sulfur, and include, but are not limited to, transition metal salts of disubstituted dithiocarbamate and tetrasubstituted sulfur methyl sulfide Guanamine. Suitable dithiocarbamates include, for example, zinc dimethyldithiocarbamate (ZDMC), zinc diethyldithiocarbamate (ZDEC), zinc dibutyldithiocarbamate (ZDBC) ), ethyl phenyl dithiocarbamate (ZEPC), zinc dibenzyl dithiocarbamate (ZBEC), zinc pentyl dithiocarbamate (Z5MC), diethyl dithiocarbamate Nickel, dibutyl dithiocarbamate, nickel dimethyldithiocarbamate and zinc diisodecyldithiocarbamate. Preferred tetra-substituted sulfurized methylsulfonium carbenes include, for example, tetrabenzylcarbithione disulfide, mercaptobenzothiazole, mercaptothiazoline, mercaptobenzimidazole, mercapto imidazole, mercaptobenzoene Oxazole, mercaptothiazole, mercaptotriazole, dithiocyanuric acid and trithiocyanuric acid. Combinations of one or more metal inhibitors can also be used. In a preferred embodiment, the metallization inhibitor comprises nickel dibutyl dithiocarbamate or tetrabenzyl methylthiocarbamate disulfide.

Suitable non-aqueous solvents include, but are not limited to, butylene carbonate, propyl carbonate, ethyl carbonate, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, propyl lactate, γ-butyl Lactone, ethyl 3-ethoxypropionate and diethylene glycol monomethyl ether acetate, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monoethyl ether acetate Ester, diethylene glycol mono-n-butyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, propylene glycol monobutyl ether acetate, dipropylene glycol monomethyl ether Acetate, dipropylene glycol monoethyl ether acetate, ethylene glycol diacetate, the above are by way of example only and not limitation.

The solvent mixture must be capable of dissolving an effective amount of metallization inhibitor, can be easily flushed from the treated pylon, and is preferably non-volatile, and can be safely handled in terms of toxicity and flammability. In addition, the solvent mixture must not damage the coating of the pylon. Solvents which are very soluble in water have been found to be difficult to dissolve in water-insoluble metallization inhibitors and thus do not provide effective metallization inhibition. However, a solvent that is capable of easily dissolving the inhibitor and providing a better degree of inhibition of the substantially water-insoluble solvent can cause a greater degree of attack on the pylon coating and, after processing, is more difficult to flush off the pylon. .

The degree of attack on the pylon coating is related to the extent to which the metallization inhibitor diffuses to the surface of the pylon coating. Therefore, the choice of solvent is important for the success of the process.

The metallization inhibitors described herein can be easily applied to the pylon in a typical processing procedure while removing unwanted metal deposits from the top of the contact points.

The invention will now be illustrated by the following non-limiting examples.

Comparative Example 1:

The ABS test panel and the new PVC plastisol coated test piece were subjected to a standard pretreatment sequence comprising the following stages: 1) containing 400 g/L chromic acid, 350 g/L sulfuric acid and 0.1 g/L full The test piece was etched in a solution of fluorooctane sulfonic acid (for 8 minutes at 65 ° C); 2) rinsing; 3) the test piece was subjected to a reduction stage with an aqueous solution containing hydroxylamine hydrochloride and hydrochloric acid; 4) rinsing; Before immersing, the test piece was immersed in a 30% hydrochloric acid solution as a prepreg; 6) The test piece was immersed in a conventional palladium/tin activator (MacDermid Macuplex D34C) at 30 ° C for 3 minutes; 7) Rinse 8) The test piece was immersed in a conventional accelerator solution (MacDermid Ultracel 9369) for 2 minutes at 50 ° C; 9) rinsed; 10) The test piece was immersed at 30 ° C in electroless nickel designed for plating plastic articles The process (MacDermid Macuplex J64) takes up to 7 minutes.

After this treatment, the test piece was inspected. As a result, it was found that the ABS test plate was completely covered by electroless nickel and had no significant pores. Subsequent plating results from this test board produce complete coverage and good adhesion Sex. The test piece coated with PVC plastisol showed no electroless nickel coating. Repeated cycles of steps 1-10 for ABS and PVC test pieces continue to show that ABS has a completely electroless nickel coating, while PVC is not coated with an electroless nickel.

Comparative Example 2:

The ABS test panel and the new PVC plastisol coated test piece were subjected to a pretreatment sequence comprising the following stages: 1) The test piece was immersed at 35 ° C containing 100 ml / liter of propylene carbonate and 50 ml / 2 minutes of solvent pre-dip of γ-butyrolactone; 2) rinsing; 3) etching test piece 20 at 68 ° C in 12.5 M sulfuric acid solution containing 0.04 M manganese sulfate and 0.02 M manganese (III) ion Minutes; 4) rinsing; 5) applying a reduction phase to the test piece with an aqueous solution containing ascorbic acid; and 6) performing stages 4 to 10 of Comparative Example 1.

After this treatment, the test piece was inspected. As a result, it was found that the ABS test plate was completely covered by electroless nickel and had no significant pores. Subsequent plating results of this test panel resulted in complete coating and good adhesion. The test piece coated with PVC plastisol showed a large amount of coating of electroless nickel, which was observed to cover a surface area of 10% to 50%. This is expected to cause considerable problems in business practice. Repeated cycles of ABS and PVC plastisol coated test pieces in steps 1-6 continuously show that ABS has completely electroless nickel coating, while PVC plastisol coated test pieces have progressively increased electroless nickel plating. cover.

Comparative Example 3:

The old PVC plastisol coated test piece which has been circulated hundreds of times in the manufacturing equipment using the hexavalent chromium treatment solution is leached in hot water for several hours to remove any residual hexavalent chromium on the surface (this invention It has been confirmed that this leaching operation is effective in eliminating any metallization inhibition provided by hexavalent chromium in the PVC plastisol).

The ABS test panel and the old PVC plastisol coated test piece were subjected to the treatment of Stages 1-6 of Comparative Example 2.

After this treatment, the test piece was inspected. The ABS test board is completely covered by electroless nickel and has no visible porosity. Subsequent plating results of this test panel resulted in complete coating and good adhesion. The test piece coated with PVC plastisol showed complete coating of electroless nickel on the entire surface of the plastisol test piece. This is totally unacceptable in business practice.

Comparative Example 4:

The new PVC plastisol coated test piece was treated as follows: A. The plastisol coated test piece was immersed in γ-butyrolactone at 65 ° C for 10 minutes; B. The test piece was rinsed and given dry.

The ABS test panel and the treated PVC plastisol coated test piece were processed through the following stages: 1) The test piece was immersed at 35 ° C with 100 ml / liter of propylene carbonate and 50 ml / liter of γ-butyl Solvent prepreg of lactone for 2 minutes; 2) rinse; 3) Etching the test piece for 20 minutes at 68 ° C in a 12.5 M sulfuric acid solution containing 0.04 M manganese sulfate and 0.02 M manganese (III) ion; 4) Rinse; 5) Applying the test piece to an aqueous solution containing ascorbic acid Stages; and 6) Stages 4 to 10 of Comparative Example 1 were carried out.

After this treatment, the test piece was inspected. As a result, it was found that the ABS test plate was completely covered by electroless nickel and had no significant pores. Subsequent plating results of this test panel resulted in complete coating and good adhesion. The test piece coated with PVC plastisol showed a large amount of coating of electroless nickel, which was observed to cover a surface area of 10% to 50%. No significant difference was observed between the PVC plastisol coated test piece treated in the solvent and the PVC plastisol coated test piece not treated in the solvent.

These comparative examples illustrate the problem of accompanying pylon plating when using a chrome-free pretreatment procedure, and illustrate that when used without hexavalent chromium, the old used PVC plastisol surface is newer than the new one. The surface of the PVC plastisol is easier to metallize. Comparative Example 4 is illustrative of the fact that treatment with a solvent without an inhibitor is ineffective.

Example 1:

The new PVC plastisol coated test piece was treated as follows: A. The plastisol coated test piece was immersed in a γ containing 20 g/L of dibutyl dithiocarbamate at 65 ° C. - Butyrolactone solution for 10 minutes; B. Rinse the test piece and dry.

The ABS test panel and the treated PVC plastisol coated test piece were processed through the following stages: 1) The test piece was immersed at 35 ° C with 100 ml / liter of propylene carbonate and 50 ml / liter of γ-butyl Solvent prepreg of lactone for 2 minutes; 2) rinsing; 3) etching the test piece in a 12.5 M sulfuric acid solution containing 0.04 M manganese sulfate and 0.02 M manganese (III) ion at 68 ° C for 20 minutes; 4) Rinsing; 5) applying a reduction stage to the test piece with an aqueous solution containing ascorbic acid; and 6) performing stages 4 to 10 of Comparative Example 1.

After this treatment, the test piece was inspected. As a result, it was found that the ABS test plate was completely covered by electroless nickel and had no significant pores. Subsequent plating results of this test panel resulted in complete coating and good adhesion. In addition, the test piece coated with PVC plastisol showed no electroless nickel coating.

The repeated cycles of ABS and treated PVC plastisol test pieces in steps 1-6 continuously show that ABS has completely electroless nickel coating, and the treated PVC plastisol coated test piece is not until the third cycle. Electroless nickel coated. After the third cycle, about 10% metallization was seen on the PVC plastisol. At this stage, the test piece coated with PVC plastisol was subjected to a second treatment in the inhibitor solution, and then the cycle was repeated again to carry out steps 1 to 6. At least another 3 cycles, no metallization was observed on the treated PVC plastisol. At the same time, the ABS test panel was completely electroless. Nickel coated. The appearance of the PVC plastisol is still satisfactory, with little or no difference from the initial appearance.

Example 2:

The new PVC plastisol coated test piece was treated as follows: A. The plastisol coated test piece was immersed at 42 ° C in a powder containing 20 g / liter of dibutyl dithiocarbamate - Ethyl ethionate solution for 30 minutes; B. Rinse the test piece and dry.

The ABS test panels and the treated PVC plastisol coated test pieces were processed via Stages 1-6 as described in Example 1.

After this treatment, the test piece was inspected. As a result, it was found that the ABS test plate was completely covered by electroless nickel and had no significant pores. Subsequent plating results of this test panel resulted in complete coating and good adhesion. The treated PVC plastisol coated test piece showed no electroless nickel coating.

The ABS and treated PVC plastisol coated test pieces were subjected to the repeated cycles of steps 1-6 described in Example 1 to continuously show that the ABS had a completely electroless nickel coating, and the treated PVC plastisol test piece reached the fourth time. The cycle is still not coated with electroless nickel.

The appearance of the PVC plastisol is still satisfactory, but it is softer than the initial coating.

Example 3:

The new PVC plastisol coated test piece was treated as follows: A. The plastisol-coated test piece was immersed in a solution of 10 g / liter of tetrabenzylthiocarbamate disulfide in ethyl 3-ethoxypropionate for 10 minutes at 40 ° C; B. rinse test The tablets are dried.

The ABS test panels and the treated PVC plastisol coated test pieces were processed via Stages 1-6 as described in Example 1.

After the treatment, the test piece was inspected. As a result, it was found that the ABS test plate was completely covered by electroless nickel and had no significant pores. Subsequent plating results of this test panel resulted in complete coating and good adhesion. The treated PVC plastisol coated test piece showed no electroless nickel coating.

ABS and treated PVC plastisol coated test pieces were subjected to the repeated cycles of steps 1-6 described in Example 1 to continuously show that ABS was completely electroless nickel coated, and the treated PVC plastisol was reached the sixth. The secondary cycle is still not coated with electroless nickel. After the 6th cycle, a small amount of metallization was observed on the PVC plastisol. At this stage, the test piece coated with PVC plastisol was subjected to a second treatment in the inhibitor solution, and then the cycle was repeated again to carry out the steps 1 to 6 described in Example 1. At least another six cycles, no metallization was observed on the treated PVC plastisol, while a completely electroless nickel coating was obtained on the ABS test panel.

The appearance of the PVC plastisol is still satisfactory, with little or no difference from the initial appearance.

Example 4:

The new PVC plastisol coated test piece was treated as follows: A. The plastisol coated test piece was immersed at 40 ° C with 10 g / liter of tetrabenzylcarbocarbazide disulfide. The solution was dissolved in ethyl 3-ethoxypropionate for 30 minutes; B. The test piece was rinsed and dried.

The ABS test panels and the treated PVC plastisol coated test pieces were processed via Stages 1-6 as described in Example 1.

After this treatment, the test piece was inspected. As a result, it was found that the ABS test plate was completely covered by electroless nickel and had no significant pores. Subsequent plating results of this test panel resulted in complete coating and good adhesion. The treated PVC plastisol coated test piece showed no electroless nickel coating.

The ABS and the treated PVC plastisol coated test piece were subjected to the above steps A and B and then to the repeated cycles of steps 1-6 described in Example 1 (also before each etching and metallization cycle, in the inhibition) The treatment of PVC plastisol in the solution) continuously shows that ABS has completely electroless nickel coating, while the treated PVC plastisol has no or only a small amount of electroless nickel coating on the 10th cycle, on PVC plastisol. A small amount of metallization can be seen.

The appearance of the PVC plastisol is still satisfactory, but it is softer than the initial coating.

Example 5:

The old plastisol test piece, which has been circulated hundreds of times in a manufacturing facility using a hexavalent chromium treatment solution, was leached in hot water for several hours to remove residual hexavalent chromium on the surface.

The old PVC plastisol coated test piece was treated as follows: A. The plastisol coated test piece was immersed at 40 ° C with 10 g / liter of tetrabenzylcarbocarbazide disulfide The solution of n-propyl lactate and ethyl 3-ethoxypropionate was allowed to stand for 5 minutes; B. The test piece was rinsed and dried.

The ABS test panels and the treated PVC plastisol coated test pieces were processed via Stages 1-6 as described in Example 1.

After the treatment, the test piece was inspected. As a result, it was found that the ABS test plate was completely covered by electroless nickel and had no significant pores. Subsequent plating results of this test panel resulted in complete coating and good adhesion. The treated PVC plastisol coated test piece showed no coating by electroless nickel, although it was a coating that had been used and aged multiple times with cracked and rough surfaces.

The ABS and the treated PVC plastisol coated test piece were subjected to the above-described steps A and B and then to the repeated cycles of steps 1-6 described in Example 1 (in this embodiment, each etching and metallization) Prior to cycling, the plastisol coating was treated in the inhibitor solution. It was consistently shown that ABS had a completely electroless nickel coating, while the treated PVC plastisol did not have an electroless nickel coating until the 25th cycle.

Example 6

The new PVC plastisol coated test piece was treated as follows: A. The plastisol coated test piece was immersed at 40 ° C in lactic acid containing 10 g / liter of tetrabenzylcarbocarbazide disulfide A solution of n-propyl ester and ethyl 3-ethoxypropionate for 2 minutes; B. Rinse the test piece and dry.

The ABS test panels and the treated PVC plastisol coated test pieces were processed via Stages 1-6 as described in Example 1.

After the treatment, the test piece was inspected. As a result, it was found that the ABS test plate was completely covered by electroless nickel and had no significant pores. Subsequent plating results of this test panel resulted in complete coating and good adhesion. The treated PVC plastisol coated test piece showed no electroless nickel coating.

The ABS and the treated PVC plastisol coated test piece were subjected to the above-described steps A and B and then to the repeated cycles of steps 1-6 described in Example 1 (in this embodiment, each etching and metallization) Prior to cycling, the treatment of PVC plastisol coatings in the inhibitor solution continued to show that ABS had a completely electroless nickel coating, while the treated PVC plastisol did not have an electroless nickel coating until the 25th cycle.

The appearance of the PVC plastisol is still satisfactory, with little or no difference from the initial appearance.

Claims (23)

An electroplating rack for supporting a non-conductive substrate in a plating process, wherein the electroplating rack is at least partially coated with a PVC plastisol; and wherein the electroplating rack is non-aqueous via a metallization inhibitor Solution treatment; wherein the electroplating rack treated by the non-aqueous solution containing the metallization inhibitor is processed in a chromium-free etchant; wherein the metallization inhibitor is selected from zinc dimethyldithiocarbamate, Zinc diethyldithiocarbamate, zinc dibutyldithiocarbamate, zinc ethylphenyldithiocarbamate, zinc dibenzyldithiocarbamate, zinc pentyl dithiocarbamate , bismuth diethyldithiocarbamate, nickel dibutyldithiocarbamate, nickel dimethyldithiocarbamate, zinc diisodecyldithiocarbamate, tetrabenzylsulfide carbon disulfide Tetrabenzylthium disulfide, mercaptobenzothiazole, mercaptothiazoline, mercaptobenzimidazole, mercapto imidazole, mercaptobenzo a group consisting of azole, mercaptothiazole, decyltriazole, dithiocyanuric acid, trithiocyanuric acid, and a combination of one or more of the foregoing; wherein the non-aqueous solution comprises a non-aqueous solvent, the non-aqueous solvent Select free butyl carbonate, propyl carbonate, ethyl carbonate, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, propyl lactate, γ-butyrolactone, 3-ethoxypropionic acid Ester and diethylene glycol monomethyl ether acetate, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol mono-n-butyl ether Acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, propylene glycol monobutyl ether acetate, dipropylene glycol monomethyl ether acetate, dipropylene glycol monoethyl ether acetate An ester, ethylene glycol diacetate, and a combination of one or more of the foregoing. The electroplated rack of claim 1, wherein the metallization inhibitor is at least substantially insoluble in the aqueous medium. The electroplating rack of claim 2, wherein the metallization inhibitor is an organic compound containing divalent sulfur. The electroplating pylon of claim 2, wherein the metallization inhibitor comprises a transition metal salt of a disubstituted dithiocarbamate or a tetra-substituted sulfurized methyl carbamide. The electroplating pylon of claim 2, wherein the metallization inhibitor comprises nickel dibutyl dithiocarbamate or tetrabenzyl methane carbamide disulfide. The electroplated rack of claim 1, wherein the non-aqueous solvent is non-volatile and capable of dissolving an effective amount of a metallization inhibitor. The electroplating rack of claim 6, wherein the non-aqueous solvent comprises ethyl 3-ethoxypropionate, n-propyl lactate, γ-butyrolactone or a combination of one or more of the foregoing. A method of processing a plating rack for supporting a non-conductive substrate in a plating process, wherein the plating rack is at least partially coated with a PVC plastisol, the method comprising: a) hanging the plating The rack is contacted with a non-aqueous solution containing a metallization inhibitor; b) the non-conductive substrate is mounted on the plating rack that has been in contact with the non-aqueous solution containing the metallization inhibitor; c) is free of chromic acid An etchant to etch the non-conductive substrate supported on the plating rack; wherein the metallization inhibitor is selected from the group consisting of zinc dimethyldithiocarbamate, zinc diethyldithiocarbamate, Zinc dibutyl dithiocarbamate, zinc ethyl phenyl dithiocarbamate, zinc dibenzyl dithiocarbamate, zinc pentyl dithiocarbamate, bismuth diethyl dithiocarbamate , nickel dibutyl dithiocarbamate, nickel dimethyl dithiocarbamate, zinc diisodecyl dithiocarbamate, tetrabenzyl methanethiocarbamate disulfide, mercaptobenzothiazole, mercaptothiazole Porphyrin, mercaptobenzimidazole, mercapto imidazole, mercaptobenzo a group consisting of azole, mercaptothiazole, decyltriazole, dithiocyanuric acid, trithiocyanuric acid, and a combination of one or more of the foregoing; wherein the non-aqueous solution comprises a non-aqueous solvent, the non-aqueous solvent Select free butyl carbonate, propyl carbonate, ethyl carbonate, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, propyl lactate, γ-butyrolactone, 3-ethoxypropionic acid Ester and diethylene glycol monomethyl ether acetate, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol mono-n-butyl ether Acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, propylene glycol monobutyl ether acetate, dipropylene glycol monomethyl ether acetate, dipropylene glycol monoethyl ether acetate An ester, ethylene glycol diacetate, and a combination of one or more of the foregoing. The method of claim 8, wherein the plating rack is contacted with the non-aqueous solution by dipping the plating rack into the non-aqueous solution. The method of claim 8, wherein the metallization inhibitor is at least substantially Insoluble in aqueous media. The method of claim 10, wherein the metallization inhibitor is an organic compound containing divalent sulfur. The method of claim 10, wherein the metallation inhibitor comprises a transition metal salt of a disubstituted dithiocarbamate or a tetra-substituted sulfurized methanecarbamide. The method of claim 12, wherein the metallization inhibitor comprises nickel dibutyl dithiocarbamate or tetrabenzyl methylthiocarbamate disulfide. The method of claim 8, wherein the non-aqueous solvent is non-volatile and capable of dissolving an effective amount of a metalation inhibitor. The method of claim 14, wherein the non-aqueous solvent comprises ethyl 3-ethoxypropionate, n-propyl lactate, γ-butyrolactone or a combination of one or more of the foregoing. The method of claim 8, wherein the non-aqueous solution contains from about 5 grams per liter to about 40 grams per liter of the metallization inhibitor. The method of claim 16, wherein the non-aqueous solution contains from about 10 grams per liter to about 25 grams per liter of the metallization inhibitor. The method of claim 17, wherein the non-aqueous solution contains from about 15 grams per liter to about 20 grams per liter of the metallization inhibitor. The method of claim 9, wherein the non-aqueous solution is maintained at a temperature between about 25 ° C and about 75 ° C during the immersion of the electroplated pylon into the non-aqueous solution. The method of claim 19, wherein the non-aqueous solution is maintained at a temperature between about 35 ° C and about 65 ° C during the immersion of the electroplated pylon in the non-aqueous solution. The method of claim 9, wherein the plating rack is immersed in the non-aqueous solution for between about 1 minute and about 60 minutes. The method of claim 21, wherein the plating rack is immersed in the non-aqueous solution for between about 2 minutes and about 30 minutes. The method of claim 8, further comprising the steps of: a) activating the non-conductive material by immersing the plating rack on which the non-conductive substrate is mounted in a solution containing colloidal palladium/tin or ionic palladium; The surface of the substrate; b) immersing the plating rack comprising the etched and activated non-conductive substrate mounted thereon in an electroless metallization bath to deposit metal thereon in an electroless manner; The non-conductive substrate is electroplated to plate a metal thereon, wherein the portion of the treated coating of the plating rack is still free of electrolessly deposited metal.