CA1079454A - Electroless nickel plating - Google Patents
Electroless nickel platingInfo
- Publication number
- CA1079454A CA1079454A CA264,193A CA264193A CA1079454A CA 1079454 A CA1079454 A CA 1079454A CA 264193 A CA264193 A CA 264193A CA 1079454 A CA1079454 A CA 1079454A
- Authority
- CA
- Canada
- Prior art keywords
- plating solution
- solution
- stabilizer
- acid
- iodo
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C18/00—Chemical coating by decomposition of either liquid compounds or solutions of the coating forming compounds, without leaving reaction products of surface material in the coating; Contact plating
- C23C18/16—Chemical coating by decomposition of either liquid compounds or solutions of the coating forming compounds, without leaving reaction products of surface material in the coating; Contact plating by reduction or substitution, e.g. electroless plating
- C23C18/31—Coating with metals
- C23C18/32—Coating with nickel, cobalt or mixtures thereof with phosphorus or boron
- C23C18/34—Coating with nickel, cobalt or mixtures thereof with phosphorus or boron using reducing agents
- C23C18/36—Coating with nickel, cobalt or mixtures thereof with phosphorus or boron using reducing agents using hypophosphites
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C18/00—Chemical coating by decomposition of either liquid compounds or solutions of the coating forming compounds, without leaving reaction products of surface material in the coating; Contact plating
- C23C18/16—Chemical coating by decomposition of either liquid compounds or solutions of the coating forming compounds, without leaving reaction products of surface material in the coating; Contact plating by reduction or substitution, e.g. electroless plating
- C23C18/31—Coating with metals
- C23C18/32—Coating with nickel, cobalt or mixtures thereof with phosphorus or boron
- C23C18/34—Coating with nickel, cobalt or mixtures thereof with phosphorus or boron using reducing agents
Abstract
ABSTRACT OF THE DISCLOSURE
This invention is for a stabilized electroless plating solution for nickel and its alloys which solution contains an iodo substituted organic compound soluble in solution to the extent of at least one part per million parts of solution.
This invention is for a stabilized electroless plating solution for nickel and its alloys which solution contains an iodo substituted organic compound soluble in solution to the extent of at least one part per million parts of solution.
Description
This invention relates to autocatalytic electroless deposition of nickel and has for its principal object, provision for a stabilized nickel plating solution.
Electroless plating refers to the chemical reductive plating of metal over an active surface in the absence of an external electric current. Such processes and compositions useful therefor are known and are in substantial commercial use. Known electroless nickel solutions comprise four primary ingredients dissolvea in water. These are (1) source of nickel ions, (2) a reducing agent therefor such as a hypophosphite, (3) acid or alkali sufficient to provide the required p~ at which said compositions are effective and ~4) a complexing agent for the nickel sufficient to prevent its precipitation in solution.
The above nickel plating compositions containing both an oxidizing and a reducing agent present in the same solution have limited stability and tend to trigger (spontaneously decompose) with reduction of substantially all nickel in the solution. It is believed that a possible mechanism responsible for initiating triggering of the electroless solution is introduced into the electroless solution of ions or metallic particles of the catalytic metal used to catalyze a substrate prior to deposition -- viz., palladium in ionic or colloidal form.
The catalytic metal in solution is balieved to aid in the formation of small amounts of metallic nickel particles - which catalyze the plating reaction in the solution rather than on the surface to be plated.
To avoid spontaneous decomposition of a plating bath, it is customary to include stabilizers in the composition which provide resistance against triggering and which increase the range of useful concentration and temperature of the solution without destroying the capacity of the solution to deposit r. ~ . . .
. ~ , " ' ' ' ' ' : .
i794s~
nickel by reduction on catalytic surfaces in contact therewith.
Prior art stabilizing agents are well known. Many of said stabilizers are catalytic poisons and prevent deposition in concentrations in excess of several parts per million of solution. Others degrade deposit properties, the stabilizer causing dull, brittle deposits having poor corrosion resistance.
In accordance with the invention disclosed herein, an electroless plating solution for nickel and its alloys is provided containing an iodo substituted organic compound as ,stabilizer. Such stabilizer should be soluble in solution to the extent of at least one part per million parts of solution.
- Solubilization in solution may be enhanced through use of iodo substituted organic compounds having polar substitution in addition to iodo substitution. The addition of the iodo compounds to the plating solution does not degrade deposit properties.
Except for the addition of the iodo substituted organic compound as described above, the composition of the plating bath is conventional. The nickel is included in the bath in the form of a salt such as nickel sulfate. A complexing agent such as hydroxyacetic acid and a reducing agent such as hypophosphite, an amine borane or a borohydride, is also included in the solution as well as an agent to provide the ~, required solution pH. Other substances conventionally used '~ in electroless nickel plating solutions may also be included ., such as, for example, to improve the properties of the plating ~ or increase the wetability of the surface being plated or to ;' function as a secondary stabilizer.
Typical electroless nickel solutions in accordance with the invention will have ingredients in the following concen-; tration ranges:
., . ' ~ ' .
107945~
Inqredient Ex. 1 Ex. 2 Ex. 3 Ex. 4 Nickel sulfate hexahydrate (g/l) 20 -- -- 30 Nickel chloride hexahydrate (g/l) -- 30 24 __ Cuprous chloride (ppm) -- -- -- 30 Hydroxyacetic acid (100%)(g/1) 28 -- -- 30 Ethylene diamine (g/l) -- 60 -- ~~
Sodium borohydride (g/l) -- 0.5 Sodium hypophosphite monohydrate 30 -- -- 15 (g/l) Dimethyl amine borane (g/l) -- -- 2 --Ammonium hydroxide (to pH)4.5 -- -- --Sodium hydroxide (to pH) -- 14 -- __ Acetic acid (to pH) -- -- 5 4.5 Iodo Stabilizer 1 ppm to saturation Water to 1 liter It should be understood that the above concentrations are preferred, but not critical. Variations are possible without departing from the scope of the invention. With regard to the iodo substituted organic compound as stabilizer, the concentration is frequently not critical as most of such compounds are not sufficiently soluble in solution to yield sufficient quantity to retard the plating rate. However, where the iodo compound is highly soluble in solution, e.g., in excess of 250 parts per 20 million parts of solution, due to polar substitution or otherwise, some caution should be exercised at the higher concentrations to prevent retardation of theplating rate Thus, simple routine experimentation may be employed to determine the optimum concent-ration of the iodo compound necessary to achieve effective stabilization without retardation of rate. For poorly soluble compounds, the maximum concentration can be saturation or in excess of saturation where the excess is available for replenish-ment as the iodo compound is depleted such as by drag-out.
Having set forth the above general parameters, more specifically, the concentration can range from as little as 1 part per million to that amount that retards deposition, typically up to aa much as 2500 parts per million or more, ; _ 3 _ ~0~9454 depending upon the specific iodo compound used, though preferably the concentration of stabilizer varies between 10 and 1500 parts per million of solution and most preferably from 25 to 250 parts per million. As noted above, it should be understood that many iodo substituted organic compounds are very poorly soluble in the aqueous plating solution. For purposes of this invention, the compound need only be soluble to the extent necessary to stabilize the solution, which, for many compounds within the scope of this invention, requires solubility only to the extent of at least 1 part per million parts of solution.
In accordance with the preferred embodiment of this invention, the iodo compound also is substituted with at least one additional polar group to enhance solubility and desirably, the iodine is bonded directly to a carbon atom. Examples of such polar groups include halo -- e.g., chloro, bromo, and fluoro;
nitro, nitroso, sulfonate, carboxyl, amino, including substituted amines, hydroxyl, cyano (if used in concentrations that do not poison the solution), etc. Typical iodo substituted organic compounds that may be used as stabilizers include iodoacetanilide iodoacetic acid, allyliodide, iodalphionic acid, p-iodoaniline, o-iodoanisole, iodobenzene, iodobenzoic acid, methenamine, iodobenzylate, iodochlorohydroxyquinoline, iodobromohydroxy-quinoline, 3-iodo-1,2-dihydroxypropane, iodoethyl allophanate, iodoform 3,5-diiodotyrosine, iodohexamidine, dihydrochloride, 3,5,3-triiodothyronine, 7-iodo-8-hydroxy-quinoline-5-sulfonic acid, ~-iodo-isovaleryluria, 3-iodomethyl-1-methyl-2-mercapto-imidazole, p-iodophenyl sulfonyl chloride, iodophthalein sodium, iodopyracet, iodopyrine, iodosobenzene, o-iodosobenzoic acid and m-iodosalicylic acid. Of the aforesaid, the most preferred .. ...... ......... . . .
compounds are mono-nuclear aromatic acids.
In a preferred embodiment of this invention, the iodo compound is used as a stabilizer in combination with a prior art stabiliæer. Perhaps the most widely used group of stabilizers are the divalent sulphur-containing comPounds, used in amounts of from a trade to that amount that prevents deposition -- i.e.
less than 50 parts per million parts of solution (PPM). Many sulfur stabilizers are disclosed in United ~tates Patent No.
3,361,540 inr~r~e~?ted hercin by rcfercnce. Representative examples of such sulphur compounds are sodium sulfide, potassium sulfide, sodium thiocyanate, potassium dithionate, sodium thiosulfate, thiourea, 2-mercaptobenzothiazole, 1,2-ethanedithiol,
Electroless plating refers to the chemical reductive plating of metal over an active surface in the absence of an external electric current. Such processes and compositions useful therefor are known and are in substantial commercial use. Known electroless nickel solutions comprise four primary ingredients dissolvea in water. These are (1) source of nickel ions, (2) a reducing agent therefor such as a hypophosphite, (3) acid or alkali sufficient to provide the required p~ at which said compositions are effective and ~4) a complexing agent for the nickel sufficient to prevent its precipitation in solution.
The above nickel plating compositions containing both an oxidizing and a reducing agent present in the same solution have limited stability and tend to trigger (spontaneously decompose) with reduction of substantially all nickel in the solution. It is believed that a possible mechanism responsible for initiating triggering of the electroless solution is introduced into the electroless solution of ions or metallic particles of the catalytic metal used to catalyze a substrate prior to deposition -- viz., palladium in ionic or colloidal form.
The catalytic metal in solution is balieved to aid in the formation of small amounts of metallic nickel particles - which catalyze the plating reaction in the solution rather than on the surface to be plated.
To avoid spontaneous decomposition of a plating bath, it is customary to include stabilizers in the composition which provide resistance against triggering and which increase the range of useful concentration and temperature of the solution without destroying the capacity of the solution to deposit r. ~ . . .
. ~ , " ' ' ' ' ' : .
i794s~
nickel by reduction on catalytic surfaces in contact therewith.
Prior art stabilizing agents are well known. Many of said stabilizers are catalytic poisons and prevent deposition in concentrations in excess of several parts per million of solution. Others degrade deposit properties, the stabilizer causing dull, brittle deposits having poor corrosion resistance.
In accordance with the invention disclosed herein, an electroless plating solution for nickel and its alloys is provided containing an iodo substituted organic compound as ,stabilizer. Such stabilizer should be soluble in solution to the extent of at least one part per million parts of solution.
- Solubilization in solution may be enhanced through use of iodo substituted organic compounds having polar substitution in addition to iodo substitution. The addition of the iodo compounds to the plating solution does not degrade deposit properties.
Except for the addition of the iodo substituted organic compound as described above, the composition of the plating bath is conventional. The nickel is included in the bath in the form of a salt such as nickel sulfate. A complexing agent such as hydroxyacetic acid and a reducing agent such as hypophosphite, an amine borane or a borohydride, is also included in the solution as well as an agent to provide the ~, required solution pH. Other substances conventionally used '~ in electroless nickel plating solutions may also be included ., such as, for example, to improve the properties of the plating ~ or increase the wetability of the surface being plated or to ;' function as a secondary stabilizer.
Typical electroless nickel solutions in accordance with the invention will have ingredients in the following concen-; tration ranges:
., . ' ~ ' .
107945~
Inqredient Ex. 1 Ex. 2 Ex. 3 Ex. 4 Nickel sulfate hexahydrate (g/l) 20 -- -- 30 Nickel chloride hexahydrate (g/l) -- 30 24 __ Cuprous chloride (ppm) -- -- -- 30 Hydroxyacetic acid (100%)(g/1) 28 -- -- 30 Ethylene diamine (g/l) -- 60 -- ~~
Sodium borohydride (g/l) -- 0.5 Sodium hypophosphite monohydrate 30 -- -- 15 (g/l) Dimethyl amine borane (g/l) -- -- 2 --Ammonium hydroxide (to pH)4.5 -- -- --Sodium hydroxide (to pH) -- 14 -- __ Acetic acid (to pH) -- -- 5 4.5 Iodo Stabilizer 1 ppm to saturation Water to 1 liter It should be understood that the above concentrations are preferred, but not critical. Variations are possible without departing from the scope of the invention. With regard to the iodo substituted organic compound as stabilizer, the concentration is frequently not critical as most of such compounds are not sufficiently soluble in solution to yield sufficient quantity to retard the plating rate. However, where the iodo compound is highly soluble in solution, e.g., in excess of 250 parts per 20 million parts of solution, due to polar substitution or otherwise, some caution should be exercised at the higher concentrations to prevent retardation of theplating rate Thus, simple routine experimentation may be employed to determine the optimum concent-ration of the iodo compound necessary to achieve effective stabilization without retardation of rate. For poorly soluble compounds, the maximum concentration can be saturation or in excess of saturation where the excess is available for replenish-ment as the iodo compound is depleted such as by drag-out.
Having set forth the above general parameters, more specifically, the concentration can range from as little as 1 part per million to that amount that retards deposition, typically up to aa much as 2500 parts per million or more, ; _ 3 _ ~0~9454 depending upon the specific iodo compound used, though preferably the concentration of stabilizer varies between 10 and 1500 parts per million of solution and most preferably from 25 to 250 parts per million. As noted above, it should be understood that many iodo substituted organic compounds are very poorly soluble in the aqueous plating solution. For purposes of this invention, the compound need only be soluble to the extent necessary to stabilize the solution, which, for many compounds within the scope of this invention, requires solubility only to the extent of at least 1 part per million parts of solution.
In accordance with the preferred embodiment of this invention, the iodo compound also is substituted with at least one additional polar group to enhance solubility and desirably, the iodine is bonded directly to a carbon atom. Examples of such polar groups include halo -- e.g., chloro, bromo, and fluoro;
nitro, nitroso, sulfonate, carboxyl, amino, including substituted amines, hydroxyl, cyano (if used in concentrations that do not poison the solution), etc. Typical iodo substituted organic compounds that may be used as stabilizers include iodoacetanilide iodoacetic acid, allyliodide, iodalphionic acid, p-iodoaniline, o-iodoanisole, iodobenzene, iodobenzoic acid, methenamine, iodobenzylate, iodochlorohydroxyquinoline, iodobromohydroxy-quinoline, 3-iodo-1,2-dihydroxypropane, iodoethyl allophanate, iodoform 3,5-diiodotyrosine, iodohexamidine, dihydrochloride, 3,5,3-triiodothyronine, 7-iodo-8-hydroxy-quinoline-5-sulfonic acid, ~-iodo-isovaleryluria, 3-iodomethyl-1-methyl-2-mercapto-imidazole, p-iodophenyl sulfonyl chloride, iodophthalein sodium, iodopyracet, iodopyrine, iodosobenzene, o-iodosobenzoic acid and m-iodosalicylic acid. Of the aforesaid, the most preferred .. ...... ......... . . .
compounds are mono-nuclear aromatic acids.
In a preferred embodiment of this invention, the iodo compound is used as a stabilizer in combination with a prior art stabiliæer. Perhaps the most widely used group of stabilizers are the divalent sulphur-containing comPounds, used in amounts of from a trade to that amount that prevents deposition -- i.e.
less than 50 parts per million parts of solution (PPM). Many sulfur stabilizers are disclosed in United ~tates Patent No.
3,361,540 inr~r~e~?ted hercin by rcfercnce. Representative examples of such sulphur compounds are sodium sulfide, potassium sulfide, sodium thiocyanate, potassium dithionate, sodium thiosulfate, thiourea, 2-mercaptobenzothiazole, 1,2-ethanedithiol,
2,2'-thiodiethanol, dithioglycol, and thioglycollic acid.
There are other stabilizers in the prior art in addition to divalent sulfur compounds used in combination with the stabilizer of the invention. One other class of stabilizers comprises the water soluble cyanide compounds as described in United States Patent No. 3,310,430. Typical of such compounds are sodium and potassium c~anide, glyconitrile, iminodiaceto-; nitrile and 3,3'-iminodipropionitrile. The cyanide compoundis used in an amount about equal to that of the divalent sulfur compound. Another class of stabilzers are acetylinic alcohols as described in U.S. Patent No. 3,457,089.
Such compounds include ethynyl cyclohexanol, methyl butynol, dimethyl hexynol and the like. Finallv, the lead ion (Pb++) is another effective stabilizer in amounts less than 50 PPM.
. ~
Electroless plating solutiQns vary somewhat e~ratically in their stability.; This is due to the fact that initiation of the triggering mechanism of the bath is often due, in addition to the mechanism described above, to the presence of impurities or dust particles in solution which are difficult to control or eliminate. Therefore, to obtain results which reflect the stabilizing influence of the added stabilizer, the decomposition of the plating solution was .,.
~ ~,. ., ,. , . ~ . : ' 107945~
accelerated by operation of one liter of the test bath at 200F
in the presence of activated aluminum of high surface area --e.~., one half square foot surface area per liter of solution.
The aluminum was activated by a five minute immersion in a 50%
by volume solution of concentrated hydrochloric acid followed by a water rinse. Under these conditions, the plating solution of Example 1 above without stabilizer decomposed in about one to two minutes. Decomposition is that time after immersion of the aluminum when there is considerable plate-out of nickel in the solution with or without immerslon of a substrate in the solution. The first experiments used o-iodobenzoic acid as a stabilizer in the solution of Example 1.
The results are shown in Table 1 where the decomposition time for the plating bath is set forth as a function of stabilizer concentration.
Example No.o-Iodobenzoic Decomposition acid (mg/l) time (min.) 7 50 lgO
8 100 >240 2 9 500 >240 10 2,500 >2~0 In the above examples, it should be noted that most of the decomposition times are to the nearest five minutes. The reason is that decomposition is a subjactive measurement as it is not instantaneous, but rather initiates and becomes progressively worse over a period of time, typically taking from five to ten minutes for acomp te decomposition. An attempt was made to record decomposition time at a point when the decomposition was severe, but experimental error is associated with this type of determination.
; 30 The above procedure was repreated using other iodo substituted organics in a nic]cel bath having the following formulation:
107945~
Nickel sulfate hexahydrate (g/l) 20 Malic acid (g/1) 20 Sodium hypophosphite (g/1) 20 Ammonium hydroxide to pH 5 Water to 1 liter The above formulation in the absence of a stabilizer decomposed in 4 minutes. With an iodo substituted organic stablizer, the following stabilities were obtained.
Example No. Stabilizer Amount Decomposition - (mg/l) time (min.) 11 5-iodosalicylic acid 150 15 12 3-iodopropionic acid 100 10 13 3-iodopropionic acid 200 50 14 2-amino-5-iodobenzoic 200 20 acid o-iodohippuric 100 15 16 o-iodohippuric 200 30 17 iodoacetic 100 >60 18 iodoacetamide 100 >60 19 m-iodobenzylamine 100 10 2020 m-iodobenzylamine 200 15 It should be understood that the stabilizers of this ~; invention work equally well with other nickel plating solutions such as the plating solution of Example 11 of U.S. Patent No.
There are other stabilizers in the prior art in addition to divalent sulfur compounds used in combination with the stabilizer of the invention. One other class of stabilizers comprises the water soluble cyanide compounds as described in United States Patent No. 3,310,430. Typical of such compounds are sodium and potassium c~anide, glyconitrile, iminodiaceto-; nitrile and 3,3'-iminodipropionitrile. The cyanide compoundis used in an amount about equal to that of the divalent sulfur compound. Another class of stabilzers are acetylinic alcohols as described in U.S. Patent No. 3,457,089.
Such compounds include ethynyl cyclohexanol, methyl butynol, dimethyl hexynol and the like. Finallv, the lead ion (Pb++) is another effective stabilizer in amounts less than 50 PPM.
. ~
Electroless plating solutiQns vary somewhat e~ratically in their stability.; This is due to the fact that initiation of the triggering mechanism of the bath is often due, in addition to the mechanism described above, to the presence of impurities or dust particles in solution which are difficult to control or eliminate. Therefore, to obtain results which reflect the stabilizing influence of the added stabilizer, the decomposition of the plating solution was .,.
~ ~,. ., ,. , . ~ . : ' 107945~
accelerated by operation of one liter of the test bath at 200F
in the presence of activated aluminum of high surface area --e.~., one half square foot surface area per liter of solution.
The aluminum was activated by a five minute immersion in a 50%
by volume solution of concentrated hydrochloric acid followed by a water rinse. Under these conditions, the plating solution of Example 1 above without stabilizer decomposed in about one to two minutes. Decomposition is that time after immersion of the aluminum when there is considerable plate-out of nickel in the solution with or without immerslon of a substrate in the solution. The first experiments used o-iodobenzoic acid as a stabilizer in the solution of Example 1.
The results are shown in Table 1 where the decomposition time for the plating bath is set forth as a function of stabilizer concentration.
Example No.o-Iodobenzoic Decomposition acid (mg/l) time (min.) 7 50 lgO
8 100 >240 2 9 500 >240 10 2,500 >2~0 In the above examples, it should be noted that most of the decomposition times are to the nearest five minutes. The reason is that decomposition is a subjactive measurement as it is not instantaneous, but rather initiates and becomes progressively worse over a period of time, typically taking from five to ten minutes for acomp te decomposition. An attempt was made to record decomposition time at a point when the decomposition was severe, but experimental error is associated with this type of determination.
; 30 The above procedure was repreated using other iodo substituted organics in a nic]cel bath having the following formulation:
107945~
Nickel sulfate hexahydrate (g/l) 20 Malic acid (g/1) 20 Sodium hypophosphite (g/1) 20 Ammonium hydroxide to pH 5 Water to 1 liter The above formulation in the absence of a stabilizer decomposed in 4 minutes. With an iodo substituted organic stablizer, the following stabilities were obtained.
Example No. Stabilizer Amount Decomposition - (mg/l) time (min.) 11 5-iodosalicylic acid 150 15 12 3-iodopropionic acid 100 10 13 3-iodopropionic acid 200 50 14 2-amino-5-iodobenzoic 200 20 acid o-iodohippuric 100 15 16 o-iodohippuric 200 30 17 iodoacetic 100 >60 18 iodoacetamide 100 >60 19 m-iodobenzylamine 100 10 2020 m-iodobenzylamine 200 15 It should be understood that the stabilizers of this ~; invention work equally well with other nickel plating solutions such as the plating solution of Example 11 of U.S. Patent No.
3,832,168. Using iodobenzoic acid the formulation of Example 11 '~ or in the formulations of Examples 2 and 3 above in a concen-tration of 250 ppm, the time to decompose will exceed 60 minutes.
Example 21 To determine the effect of various of the aforesaid stabilizers on the plating properties of a bath and the functional properties of the nickel deposits formed therefrom, the following plating sequence was followed:
a. Immerse low carbon steel part in an organic solvent degreaser for 2-3 minutes.
~ -7-- . ' ' : ' .
b. Dry and immerse part in a cleaning solution of 8 ounces per gallon of Anodic Electroclean Maxiamp (a trademark) for 2-3 .
~ 20 ,~
`' .
, ~
., . ~
' G, , ~ 30 ., .
. ' :
:~ -7a-minutes at a temperature of about 185F.
c. Rinse twiceand pickle in Activato( ~424~ at a temperature of about 165F.
d. Rinse and plate with nickel plating solution to thickness requried at a temperature of about 200F.
The above plating procedure was used with the formula-tions of examples 6, 8, 10 and 17. In all cases, deposits having good properties were obtained. It is noted that plating rate in certain of the examples was somewhat decreased, particu-larly in those examples where the amount of total stabilizerwas 500 milligrams per liter or more.
Examples 22-26 Conventional secondary stabilizers were added to the bath of example 6 with results as follows:
Example No. StabilizerAmt. Decomposition (ppm) time (min.) 22 sodium cyanide5 >120 23 phenylmercuric20 >120 acetate ' 24 2-mercaptobenzo-5 >120 '~ thiazole Butynediol 20 >120 26 lead acetate 5 >120 - From the above, it can be seen that the secondary - stabilizer markedly improves the stability of the baths.
' s ...
Example 21 To determine the effect of various of the aforesaid stabilizers on the plating properties of a bath and the functional properties of the nickel deposits formed therefrom, the following plating sequence was followed:
a. Immerse low carbon steel part in an organic solvent degreaser for 2-3 minutes.
~ -7-- . ' ' : ' .
b. Dry and immerse part in a cleaning solution of 8 ounces per gallon of Anodic Electroclean Maxiamp (a trademark) for 2-3 .
~ 20 ,~
`' .
, ~
., . ~
' G, , ~ 30 ., .
. ' :
:~ -7a-minutes at a temperature of about 185F.
c. Rinse twiceand pickle in Activato( ~424~ at a temperature of about 165F.
d. Rinse and plate with nickel plating solution to thickness requried at a temperature of about 200F.
The above plating procedure was used with the formula-tions of examples 6, 8, 10 and 17. In all cases, deposits having good properties were obtained. It is noted that plating rate in certain of the examples was somewhat decreased, particu-larly in those examples where the amount of total stabilizerwas 500 milligrams per liter or more.
Examples 22-26 Conventional secondary stabilizers were added to the bath of example 6 with results as follows:
Example No. StabilizerAmt. Decomposition (ppm) time (min.) 22 sodium cyanide5 >120 23 phenylmercuric20 >120 acetate ' 24 2-mercaptobenzo-5 >120 '~ thiazole Butynediol 20 >120 26 lead acetate 5 >120 - From the above, it can be seen that the secondary - stabilizer markedly improves the stability of the baths.
' s ...
Claims (11)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. In an electroless nickel plating solution compris-ing a source of nickel ions, a reducing agent therefor, a complex-ing agent for said ions and a pH adjuster to provide necessary solution pH, the improvement comprising a stabilizer comprising an iodo substituted mono-nuclear aromatic compound soluble in said solution in an amount of at least 1 part per million and sufficient to improve stability of said plating solution without substantially retarding the rate of deposition.
2. A solution as claimed in claim 1 in which the stabilizer is selected from the group consisting of iodoacet-anilide, iodoalphionic acid, p-iodoaniline, o-iodoanisole iodo-benzene, iodobenzoic acid, 3,5-diiodotyrosine, p-iodophenyl sul-fonyl chloride, sodium, iodopyracet, iodosobenzene, o-iodoso-benzoic acid, 5-iodosalicylic acid, 2-amino-5-iodobenzoic acid, o-iodohippuric acid, m-iodobenzylamine, and m-iodosalicylic acid in an amount of at least 1 part per million and sufficient to improve stability of said plating solution without substan-tially retarding the rate of deposition.
3. The plating solution of claim 1 in which the stabilizer is a mononuclear aromatic acid.
4. The plating solution of claim 1, 2 or 3 where the stabilizer is soluble in solution in an amount of at least 1 milligram per liter.
5. The plating solution of claim 1, 2 or 3 where the total concentration of stabilizer varies between 10 and 1500 milligrams per liter.
6. The plating solution of claim 1, 2 or 3 where the concentration of stabilizer varies between 25 and 250 milligrams per liter.
7. The plating solution of claim 1, where the stabi-lizer is substituted with polar groups in addition to iodo sub-stitution.
8. The plating solution of claim 1, where the iodo substituted compound has a direct iodine to carbon bond.
9. The plating solution of claim 7, where the stabi-lizer is o-iodobenzoic acid.
10. The plating solution of claim 1, containing a secondary stabilizer.
11. The plating solution of claim 10, where the second-ary stabilizer is selected from the group of sulfur compounds, acetylinic compounds, lead compounds, mercury compounds and cyanide compounds.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US62804675A | 1975-11-03 | 1975-11-03 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1079454A true CA1079454A (en) | 1980-06-17 |
Family
ID=24517215
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA264,193A Expired CA1079454A (en) | 1975-11-03 | 1976-10-26 | Electroless nickel plating |
Country Status (11)
| Country | Link |
|---|---|
| JP (1) | JPS5258021A (en) |
| BE (1) | BE847908A (en) |
| BR (1) | BR7607356A (en) |
| CA (1) | CA1079454A (en) |
| DE (1) | DE2650389A1 (en) |
| ES (1) | ES452927A1 (en) |
| FR (1) | FR2329762A1 (en) |
| GB (1) | GB1555709A (en) |
| IT (1) | IT1070325B (en) |
| NL (1) | NL7612134A (en) |
| SE (1) | SE429242B (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2531103B1 (en) * | 1982-07-30 | 1985-11-22 | Onera (Off Nat Aerospatiale) | BATH FOR CHEMICAL DEPOSITION OF NICKEL AND / OR COBALT USING A REDUCER BASED ON BORON OR PHOSPHORUS |
| US4600609A (en) * | 1985-05-03 | 1986-07-15 | Macdermid, Incorporated | Method and composition for electroless nickel deposition |
| FR2642670B1 (en) * | 1989-02-07 | 1991-05-24 | Eurecat Europ Retrait Catalys | METHOD FOR REDUCING A REFINING CATALYST BEFORE IMPLEMENTING IT |
| DE60239443D1 (en) * | 2001-10-24 | 2011-04-28 | Rohm & Haas Elect Mat | Stabilizers for electroless plating solutions and method of use |
| US20090239079A1 (en) * | 2008-03-18 | 2009-09-24 | Mark Wojtaszek | Process for Preventing Plating on a Portion of a Molded Plastic Part |
| EP3190208B1 (en) * | 2016-01-06 | 2018-09-12 | ATOTECH Deutschland GmbH | Electroless nickel plating baths comprising aminonitriles and a method for deposition of nickel and nickel alloys |
-
1976
- 1976-10-26 CA CA264,193A patent/CA1079454A/en not_active Expired
- 1976-10-27 SE SE7611917A patent/SE429242B/en unknown
- 1976-11-02 IT IT28963/76A patent/IT1070325B/en active
- 1976-11-02 JP JP51132248A patent/JPS5258021A/en active Granted
- 1976-11-02 FR FR7633016A patent/FR2329762A1/en active Granted
- 1976-11-02 NL NL7612134A patent/NL7612134A/en not_active Application Discontinuation
- 1976-11-02 ES ES452927A patent/ES452927A1/en not_active Expired
- 1976-11-03 DE DE19762650389 patent/DE2650389A1/en active Pending
- 1976-11-03 BE BE172012A patent/BE847908A/en unknown
- 1976-11-03 BR BR7607356A patent/BR7607356A/en unknown
- 1976-11-03 GB GB45700/76A patent/GB1555709A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5643108B2 (en) | 1981-10-09 |
| AU1920676A (en) | 1978-11-23 |
| GB1555709A (en) | 1979-11-14 |
| NL7612134A (en) | 1977-05-05 |
| BR7607356A (en) | 1977-09-20 |
| ES452927A1 (en) | 1978-02-16 |
| DE2650389A1 (en) | 1977-05-12 |
| SE429242B (en) | 1983-08-22 |
| FR2329762A1 (en) | 1977-05-27 |
| SE7611917L (en) | 1977-05-04 |
| JPS5258021A (en) | 1977-05-13 |
| FR2329762B1 (en) | 1979-02-23 |
| IT1070325B (en) | 1985-03-29 |
| BE847908A (en) | 1977-05-03 |
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Legal Events
| Date | Code | Title | Description |
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| MKEX | Expiry |