CA1255621A - Copper electrodeposition with substituted phthalocyanine and an apo safranine - Google Patents
Copper electrodeposition with substituted phthalocyanine and an apo safranineInfo
- Publication number
- CA1255621A CA1255621A CA000456108A CA456108A CA1255621A CA 1255621 A CA1255621 A CA 1255621A CA 000456108 A CA000456108 A CA 000456108A CA 456108 A CA456108 A CA 456108A CA 1255621 A CA1255621 A CA 1255621A
- Authority
- CA
- Canada
- Prior art keywords
- electrolyte
- brightening
- copper
- phthalocyanine
- apo
- 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
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Classifications
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
- C25D3/00—Electroplating: Baths therefor
- C25D3/02—Electroplating: Baths therefor from solutions
- C25D3/38—Electroplating: Baths therefor from solutions of copper
Abstract
Abstract of the Disclosure An aqueous acidic electrolyte composition and process for electrodepositing an exceptionally bright, leveled and ductile copper deposit on conductive substrates incorporating a synergistic combination of a substituted phthalocyanine brightening agent and an apo safranine brightening agent, preferably in further combination with supplemental brightening agents such as organic polysulfides, sulfides and/or polyether compounds. In accordance with the process aspects of the present invention, the foregoing copper electrolyte is employed for electrodepositing a copper plate on a conductive substrate at temperatures of from about 15° up to about 50°C and at cathode current densities ranging from as low as about 0.5 to about 400 amperes per square foot achieving exceptional brightness particularly in the low current density recess areas.
Description
COPPER ELECTRODEPOSITION WITH SUBSTITUTED
PHTHALOCYANINE AND AN APO SAFRAMINE
ckground of the Invention The present invention broadly relates to an aqueous electrolyte ccmposition and process for electrodepositing cop~r on a conductive substrate, and more particularly, to an improved aqueous acidic copper platiny bath containing a r.ovel ccmbination of brightening agents to provide a cop~er plate which is ductile, level and bright particularlv in the low current densi.y recess areas.
A variety of aqueous electrolyte CGmpOSitions ar.d processes have heretofore been used or proposed for use for electrodepositing bright, level ductile copper depositsO Typical of such prior art cc~positions and processes are those describe~
in U.S. Patent Nos. 2,707,166; 2,707,167; 2,738,318; 2,882,209;
3,267,010; 3,328,273; 3,770,598; 4,110,176 ar~ 4,2l2,335. T~
accordance with the teachings oE ~rited St2tes Patent ~o.
4,272,335 an improved aqueous acidic copper elect~olyte is provided which contains a substituted phthalocy~nir.e radical as a brightening agent ~hich in accordance with the preferred disclosure further incorporates supplemental secondary brightening agents such as polysulfides, sulfides and/or polyether ccm¢our.ds. While the aqueous acidic electrolyte as described in the afore~entioned United States patent provides for improvements in the briyhtness, leveling and cuc.ility of copper platings, under certain operating parameters and ccmposition variations, less than optimum brightness of the copper plate has been obtained in the low current density recess areas of articles being plated.
On the other hand, when an apo safranine brightening ccmpound has been employed alone or in further cGmbination ~"ith supplemental brightening agents such as polysulfides, organic sulfides and/or polyether ccmpounds, unsatisfactory brightness and leveling of the deposit has been obtained under certain conditions in low current density areas. An increase in the concentration of the apo safranine brightening co~pound to overc~me the low current density problem resulted in the formation of dark striations in the low current density areas producing an unacceptable deposit.
mere, accordingly, has been a need for a still further improvement in aqueous acidic copper electrolytes to provide exceptional brightness of copper deposits in the low current density recess areas of articles being plated which can be consistently attained over a broad range of composi-tion and processing conditions. The aqueous acidic electro]yte of the present invention incorporates a selected combination of brightening agents providing for a synergistic brightening effect, particularly in such low current density recess areas over a relatively broad range of concentrations and bath operating conditions.
Summary of the Invention The benefits and advantages of the present inv~ntion are achieved by an electrolyte CQmposition and process for eleetrod~positing copper from an aqueous acidic plating bath containing a brightening.amount of a ccmbination of compounds including a bath soluble substituted phthalocyanine c~?ound and an apo safran m e compound present in cont.rolled amounts. ~ore particularly, the aqueous acidic electrolyte is preferably of the copper sulfate or fluoroborate type and incorporates copper in an amount sufficient to electrodeposit CQpper~ and a brightening amount of the substituted phthalocyanine eompound represented by the formula:
Pc-~X)n ~herein:
Pe is a phthalocyanine radical;
X is -SO2NR2~-s03M~-cH2gc(NR2)2 R is H, alkyl containing 1-6 carbon atoms, aryl containing 6 carbon atcms, aralkyl containing 6 carbon atcms in the aryl portion and 1 to 6 carbon atQms in the aLkyl portion, - heterocyclic containing 2 to 5 carbon atoms and at least 1 nitrogen, oxygen, sulfur or phosphorus atom, and aLkyl, aryl, araIkyl and heterocyclie, as defined abcve, containing 1 to 5 amino, hydroxy, sulfonic or phosphonic groups;
:,~
- \
n is 1-6;
Y is halogen or alkyl sulfate containing 1 to 4 carbon atoms in the alkyl portion; and M is H, Li, Na, K or Mg, in further ccmbination with a ccmpound represented by Formula A.
FORMULA A
(R'.)~N .
X' ~
¢3 Wherein the R' are the same or differen-t and c~amprise -CH3, -C2H5 or -C3H7, and X' is an anion selected from the group consisting of chloride, bromide, iodide, fluoride, sulfate, bisulfate and nitrate.
,~ , ~,.
~5~
The phthalocyanine brightering agent may be ~etal-free or may contain a stable divalent or trivalent metal, such as cobalt, nickel, chromium, iron, or copper, as well as nuxtures of these of which copper constitutes the preferred ~etal.
Phthalocyanine brightening agents suitable for use in the practice of the present invention have a bath solubility of at least about 0.1 milligrams per liter (mg/1).
In accordance with a preferred practice of the present inventiOn~ the phthalocyanine and apo safranine brightening agerts are supplemented by the addition of secor.dary brightening agents including aliphatic polysulfides, organic sulfides and/or polyether compounds to further enhance the brightness and physical properties of the copper deposit.
In accordance with the process aspects of the presen~
invention, the aqueous acidic electroplating bath can be operated at temperatures ranging from about 15 up to about 50C and at current densities ranging from about 0.5 to about 400 an~eres per square foot (ASF).
Additional benefits and advantages of the present invention will become apparent upon a reading of the Description of the Preferred ~mbcd1ments taken in conjunction with the accompanying examples.
,~
Description of the Preferred Embodiments In accordance with the practice of the process of tne present invention, an aqueous acidic electrolyte is pr~ided which may be of the sulfate type typically containing about 180 to about 250 g/l of copper sulfa-te as the pentahydrate and about 30 to about 80 g/l of sulfuric acid. Alternatively, fluoroborate baths can be prepared typically containing from about 200 to about 600 g/l of copper fluoroborate and up to about 60 g/l of fluoboric acid. It is also contemplated that copper nitrate salts can be employed in approximately equivalent proportions for copper sulfate and the electrolyte can be acidified employing equivalent ~mounts of phosphoric acid, nitric acid or sulfuric acid. In accordance with the preferred practice of the present invention, sulfate-type copper baths are employed.
The aqueous electroly-te may further incorporate halide ions such as chloride and/or bromide ions in an amount up to about 0.5 g/l.
~ he exceptional brightening obtained in the low current density recess areas is achieved by employing a synergistic ccmbination of the substituted phthalocyanine brightening agent and the apo safranine brightening agent in controlled conoentrations and proportions, preferably in further ccmbination with supplemental organic brightening agents. The substituted phthalocyanine ccmpound which may be metal-free or which may contain a stable divalent or trivalent metal bound by coordination of the lsoindole nitrogen atoms of the molecule, which metal is selected from the group consisting of cobalt, nickel, chrcmium, iron or copper, as well as mixtures of the foregoing of which copper is the more typical and preferred metal. Such phthalocyanine compounds suitable for use in the practice of the present process are those having a bath solubility of at least about 0.1 mg/l and correspond to the structural formula:
~s~
t~)b ~9 ' 1. 1 ( X ) ~ N ~ Z ~ ( X b N ~
~\~
(X) 3b l~herein:
X is as has ~een heretofore defined;
Z is Ni, Co, Cr, Fe or Cu;
a is 0-1; and - b is 0-2, provided however that the total number of X substituents is 1-6.
Suhstituted phthalocyanine compounds suitable for use in the practioe of the present invention further include those as described in United States Patent No. 4,272,335. A particularly preferred ph~halocyanine cc~pound ccmprises Alcian Blue.
3S~
The c~nbil~ed brightening agents corresponding to Forrnula A and the substituted phthalocyanine brightening agent are employed at a bath concentration of frcm about 0.0005 g/l up to about 1 g/l with concentrations of about 0.002 g/l to about 0.01 g/l being preferred. The substituted phthalocyanirle brightening agent should ccmprise frorn about 35 up to about 80 percent by weight of the ccmbined weight of the t~
brightening agents ernployed. A particularly satisfaetory ccrnbination ccmprises ernploying Methie Turquoise as the substituted phthalcxcyanine brightening agent at a concentration of 3 rng/l in cornbination with an apo safranine brightening agent represented by Formula A in which R'cc~rises ethyl also present at a concentra-tion of 3 rng/l.
In addition to the substituted phthalocyanine and apo safranine brightening agents, it has been found advantageous in accordance with the practi oe of the present invention to incorporate at least one additional supplemental brighténing agent of the types known in the art to further enhance the brightness, ductility and leveling of the electrodeposited copper. Included among such supplernental brightening agents are polyether compounds and organic sulfide and disulfide ccmpounds.
The preferred organie polyether ccmpounds are bath soluble and c~npatible polyethers containing at least 4 ether oxygen atoms and having an average leeular weight ranging from about 180 up to 1,000,000. Partieularly satisfaetory results are obtained with polypropylene and polyethylene glycols ineluding mixtures of th~ foreyoing of an avera~e molecular weight of about 600 to about 6,000, and aIkoxylated arcm~tic alcohols ha~ing a molecular weight ranging from about 300 to 2500. Ex~mplary of such preferred polyether bri~htening compounds which can satisfactorily be en~loyed are polyethylene glycols of an average molecular weight of from about 400 to about 1,000,000;
ethoxylated naphthols containing 5 to 45 mols ethylene oxide groups; pr~poxylated naphthols containing 5 to 15 mols of propylene oxide groups; ethoxylated nonyl phenol containing 5 to 30 nmols ethylene oxide groups; propylene glycols of an average molecular weigh-t of about 350 to about 1,000; block polymers of polyoxyethylene and polyoxypropylene glycols of an average mole~ular weight of abou-t 350 to 250,000; ethoxylated phenols containing 5 to 100 mols of ethylene oxide groups; propoxylated phenols containing 5 to 15 mols of propylene oxide groups, and ethylene diamune block polymers having a molecular weight of about 1600 -to about 30,000. Additional polyether compounds suitable for use in the practice of the present process are those disclosed in United States Patent No. 4,272,335.
me polyether brightening compounds are employed in a range of about 0.001 up to about 5 g/l with the lower concentrations generally being used with the higher molecular weight polyethers.
Organic sulfide brightening compounds which can be satisfactorily employed in the practice of the present process include the various sulfonate organic sulfide compounds as described in United Sta-tes PaTENT ~o. 3,267,010, and particularly Table I thereof; organic sulfur compounds as disclosed in United States Patent No. 4,181,582 and particularly Table III thereof;
and the organic polysulfide compounds as disclosed in United States Patent No. 3,328,273 and particularly Table I thereof. The organic sulfide compcunds containing sulfonic or phosphonic groups may also contain various substituent groups, such as methyl, chloro, bromo, methoxy, ethoxy, carboxy or hydroxy, on the m~lecules, especially on the aromatic and heterocyclic sulfide-sulfonic or phosphonic acids. Such ccm~ounds may be used as the free acids r the alkali metal salts, organic amune salts, or the like.
Cther suitable organic divalent sulfur cc~ounds which can be satisfactorily used include HO3P-(CH2)3-S-S-(CH2)3-PO3H, as well as merca~tans, thiocarbHmates, thiolcarbamates, thioxanthates, and thiocarbonates which contain at least one sulfonic or phosphonic group.
A particularly preferred group of organic divalent sulfur compounds as described in U.S. Patent No. 3,328,273 are the organic polysulfide compounds of the formula XRl~(S)nR2S3H or ~ ~~S)n~2P3H wherein ~ and ~ are the same or different aIkylene group containing from ,~
about 1 to 6 cæbon atoms, X is hydrogen, SO3H or PO3H and n is a number frcm about 2 to 5. mese organic divalent sulfur compounds are aliphatic polysulfides wherein at least t~,~
divalent sulfur atoms are vicinal and wherein the molecule has one or two terminal sulfonic or phosphonic acid groups. The alkylene portion of the molecule may be substituted with groups such as methyl, ethyl, chloro, bromo, ethoxy, hydroxy, and the like. mese ccmpounds may be added as the free acids or as the aIkali metal or amine salts.
me organic sulfide brightening compound or mixture of compounds are present in the electrolyte within a range of about 0.0005 to about 1 g/l.
In accordance with the process aspects of the present nvention, an aqueous acidic copper electrolyte of the foregoing composition is employed in which an electrically conductive substrate is immersed and is cathodically charged for a period of time to deposit the desired thickness of copper thereon. During the electroplating operation, the bath is controlled at a temperature of frcm about 15 up to about 50C and at cathode current densities ranging from as low as about 0.5 to as high as about 400 ASF, preferably from about 10 to about 100 ASF.
Particularly satisfactory results are obtained at bath temperatures of about 20 to about 36C at current densities of about 10 to about 50 ASF.
~5~
In order to further illustrate the present in~Jention, the follc~ing typical examples are provided. It will be appreciated that the examples are provided for illustrative purposes and are not intended to be limiting of the scope of the present invention as herein described and as set forth in the subjoined claims.
EX~LE 1 An aqueous acidic copper electrolyte is prepared containing akout 165 to about 225 g/l copper sulfate pentahydrate, about 42 to about 75 g/l sulfuric acid and about O.04 to about 0.1 g/l chloride ions. Tb the foregoing aqueous solution, 3 mg/l of Methic Ttrq~loise comprising the phthalocyanine brightening agent is added along with 3 mg/l of diethyl apo safranine. As supplemental brightening agents, the bath further contains 50 mg/l of polypropylene glycol of an average molecular weight of 700 and 20 mg/l of Bis (3-sulfopropyl disulfide disodium salt).
An operation of the bath at a current density of from about 0.5 to about 100 ASF at a temperature of from about 70 to about 80F produced highly leveled, fine-grained copper desposits with no physical defects.
EXPMæLE 2 An aqueous acidic copper electrolyte is prepared containing about 165 to about 225 g/l copper sulfate pentahydrate, about 42 to about 75 g/l sulfuric acid and about s~
0.04 to about 0.1 g/1 chloride ions. To the foregoing aqueous solution, 3 mg/l of Methic Turquoise cGmprising the phthalocyanine brightening agent is added along with 60 mg/1 of a block polymer of ethylene propylene oxide (mol wt. 3000), 20 mg/l of Bis (3-sulfopropyl disulfide disodium salt) and 1.5 mg/l of the reaction product of polyethylene imine (mol wt. 600) with benzyl chloride as supplemental brightening agents.
The operation of the bath at a temperature of from about 70 to about 80F and at current densities of about 20 to about 80 ASF produces bright, leveled copper deposits. The further addition of 3 mg/l of diethyl apo safranine to the electrolyte results in a dramatic improvement in the leveling characteristics of the deposit and also substantially improves the brightness in the low current density areas of test panels employing ~he same plating parameters.
EXAMæLE 3 An aqueous acidic copper electrolyte is prepared containing about 165 to about 225 g/1 copper sulfate pentahydrate, about 42 to about 75 g/l sulfuric acid and about 0.04 to about 0.1 g/l chloride ions. To the foregoing aqueous solution, 2 mg/l of diethyl apo safranine is added in further ccmbination with supplemental brightening agents ccmprising 20 mg/l Bis (3-sulfcpropyl disulfide disodium salt), 200 mg~l polyethylene oxide (mol wt. 6000) and 1.5 mg/1 of a reaction product of polyethyleneimine (mol wt. 600) reacted with ben~yl chloride.
The foregoing electrolyte produces a bright, leveled copper deposit when plated on a J-shaped test panel at an average current density of about 50 ASF for a period of 15 minutes but t~e deposit is striated in the low curxent density area. The addition of 3 mg/l of Methic Turquoise ccmprising the substituted phthalocyanine radical brightening agent to the electxolyte results in the elimlnation of the striations in the lcw current density area of the J-type test panel plated under the same conditions without any loss of brightness and leveling of the copper deposit.
While it will be apparent that the preferred embodiments of the invention disclosed are well calculated to fulfill the objects above stated, it will be appreciated that the invention is susceptible to modification, variation and change without departing frcm the proper scope or fair meaning of the subjoined claims.
PHTHALOCYANINE AND AN APO SAFRAMINE
ckground of the Invention The present invention broadly relates to an aqueous electrolyte ccmposition and process for electrodepositing cop~r on a conductive substrate, and more particularly, to an improved aqueous acidic copper platiny bath containing a r.ovel ccmbination of brightening agents to provide a cop~er plate which is ductile, level and bright particularlv in the low current densi.y recess areas.
A variety of aqueous electrolyte CGmpOSitions ar.d processes have heretofore been used or proposed for use for electrodepositing bright, level ductile copper depositsO Typical of such prior art cc~positions and processes are those describe~
in U.S. Patent Nos. 2,707,166; 2,707,167; 2,738,318; 2,882,209;
3,267,010; 3,328,273; 3,770,598; 4,110,176 ar~ 4,2l2,335. T~
accordance with the teachings oE ~rited St2tes Patent ~o.
4,272,335 an improved aqueous acidic copper elect~olyte is provided which contains a substituted phthalocy~nir.e radical as a brightening agent ~hich in accordance with the preferred disclosure further incorporates supplemental secondary brightening agents such as polysulfides, sulfides and/or polyether ccm¢our.ds. While the aqueous acidic electrolyte as described in the afore~entioned United States patent provides for improvements in the briyhtness, leveling and cuc.ility of copper platings, under certain operating parameters and ccmposition variations, less than optimum brightness of the copper plate has been obtained in the low current density recess areas of articles being plated.
On the other hand, when an apo safranine brightening ccmpound has been employed alone or in further cGmbination ~"ith supplemental brightening agents such as polysulfides, organic sulfides and/or polyether ccmpounds, unsatisfactory brightness and leveling of the deposit has been obtained under certain conditions in low current density areas. An increase in the concentration of the apo safranine brightening co~pound to overc~me the low current density problem resulted in the formation of dark striations in the low current density areas producing an unacceptable deposit.
mere, accordingly, has been a need for a still further improvement in aqueous acidic copper electrolytes to provide exceptional brightness of copper deposits in the low current density recess areas of articles being plated which can be consistently attained over a broad range of composi-tion and processing conditions. The aqueous acidic electro]yte of the present invention incorporates a selected combination of brightening agents providing for a synergistic brightening effect, particularly in such low current density recess areas over a relatively broad range of concentrations and bath operating conditions.
Summary of the Invention The benefits and advantages of the present inv~ntion are achieved by an electrolyte CQmposition and process for eleetrod~positing copper from an aqueous acidic plating bath containing a brightening.amount of a ccmbination of compounds including a bath soluble substituted phthalocyanine c~?ound and an apo safran m e compound present in cont.rolled amounts. ~ore particularly, the aqueous acidic electrolyte is preferably of the copper sulfate or fluoroborate type and incorporates copper in an amount sufficient to electrodeposit CQpper~ and a brightening amount of the substituted phthalocyanine eompound represented by the formula:
Pc-~X)n ~herein:
Pe is a phthalocyanine radical;
X is -SO2NR2~-s03M~-cH2gc(NR2)2 R is H, alkyl containing 1-6 carbon atoms, aryl containing 6 carbon atcms, aralkyl containing 6 carbon atcms in the aryl portion and 1 to 6 carbon atQms in the aLkyl portion, - heterocyclic containing 2 to 5 carbon atoms and at least 1 nitrogen, oxygen, sulfur or phosphorus atom, and aLkyl, aryl, araIkyl and heterocyclie, as defined abcve, containing 1 to 5 amino, hydroxy, sulfonic or phosphonic groups;
:,~
- \
n is 1-6;
Y is halogen or alkyl sulfate containing 1 to 4 carbon atoms in the alkyl portion; and M is H, Li, Na, K or Mg, in further ccmbination with a ccmpound represented by Formula A.
FORMULA A
(R'.)~N .
X' ~
¢3 Wherein the R' are the same or differen-t and c~amprise -CH3, -C2H5 or -C3H7, and X' is an anion selected from the group consisting of chloride, bromide, iodide, fluoride, sulfate, bisulfate and nitrate.
,~ , ~,.
~5~
The phthalocyanine brightering agent may be ~etal-free or may contain a stable divalent or trivalent metal, such as cobalt, nickel, chromium, iron, or copper, as well as nuxtures of these of which copper constitutes the preferred ~etal.
Phthalocyanine brightening agents suitable for use in the practice of the present invention have a bath solubility of at least about 0.1 milligrams per liter (mg/1).
In accordance with a preferred practice of the present inventiOn~ the phthalocyanine and apo safranine brightening agerts are supplemented by the addition of secor.dary brightening agents including aliphatic polysulfides, organic sulfides and/or polyether compounds to further enhance the brightness and physical properties of the copper deposit.
In accordance with the process aspects of the presen~
invention, the aqueous acidic electroplating bath can be operated at temperatures ranging from about 15 up to about 50C and at current densities ranging from about 0.5 to about 400 an~eres per square foot (ASF).
Additional benefits and advantages of the present invention will become apparent upon a reading of the Description of the Preferred ~mbcd1ments taken in conjunction with the accompanying examples.
,~
Description of the Preferred Embodiments In accordance with the practice of the process of tne present invention, an aqueous acidic electrolyte is pr~ided which may be of the sulfate type typically containing about 180 to about 250 g/l of copper sulfa-te as the pentahydrate and about 30 to about 80 g/l of sulfuric acid. Alternatively, fluoroborate baths can be prepared typically containing from about 200 to about 600 g/l of copper fluoroborate and up to about 60 g/l of fluoboric acid. It is also contemplated that copper nitrate salts can be employed in approximately equivalent proportions for copper sulfate and the electrolyte can be acidified employing equivalent ~mounts of phosphoric acid, nitric acid or sulfuric acid. In accordance with the preferred practice of the present invention, sulfate-type copper baths are employed.
The aqueous electroly-te may further incorporate halide ions such as chloride and/or bromide ions in an amount up to about 0.5 g/l.
~ he exceptional brightening obtained in the low current density recess areas is achieved by employing a synergistic ccmbination of the substituted phthalocyanine brightening agent and the apo safranine brightening agent in controlled conoentrations and proportions, preferably in further ccmbination with supplemental organic brightening agents. The substituted phthalocyanine ccmpound which may be metal-free or which may contain a stable divalent or trivalent metal bound by coordination of the lsoindole nitrogen atoms of the molecule, which metal is selected from the group consisting of cobalt, nickel, chrcmium, iron or copper, as well as mixtures of the foregoing of which copper is the more typical and preferred metal. Such phthalocyanine compounds suitable for use in the practice of the present process are those having a bath solubility of at least about 0.1 mg/l and correspond to the structural formula:
~s~
t~)b ~9 ' 1. 1 ( X ) ~ N ~ Z ~ ( X b N ~
~\~
(X) 3b l~herein:
X is as has ~een heretofore defined;
Z is Ni, Co, Cr, Fe or Cu;
a is 0-1; and - b is 0-2, provided however that the total number of X substituents is 1-6.
Suhstituted phthalocyanine compounds suitable for use in the practioe of the present invention further include those as described in United States Patent No. 4,272,335. A particularly preferred ph~halocyanine cc~pound ccmprises Alcian Blue.
3S~
The c~nbil~ed brightening agents corresponding to Forrnula A and the substituted phthalocyanine brightening agent are employed at a bath concentration of frcm about 0.0005 g/l up to about 1 g/l with concentrations of about 0.002 g/l to about 0.01 g/l being preferred. The substituted phthalocyanirle brightening agent should ccmprise frorn about 35 up to about 80 percent by weight of the ccmbined weight of the t~
brightening agents ernployed. A particularly satisfaetory ccrnbination ccmprises ernploying Methie Turquoise as the substituted phthalcxcyanine brightening agent at a concentration of 3 rng/l in cornbination with an apo safranine brightening agent represented by Formula A in which R'cc~rises ethyl also present at a concentra-tion of 3 rng/l.
In addition to the substituted phthalocyanine and apo safranine brightening agents, it has been found advantageous in accordance with the practi oe of the present invention to incorporate at least one additional supplemental brighténing agent of the types known in the art to further enhance the brightness, ductility and leveling of the electrodeposited copper. Included among such supplernental brightening agents are polyether compounds and organic sulfide and disulfide ccmpounds.
The preferred organie polyether ccmpounds are bath soluble and c~npatible polyethers containing at least 4 ether oxygen atoms and having an average leeular weight ranging from about 180 up to 1,000,000. Partieularly satisfaetory results are obtained with polypropylene and polyethylene glycols ineluding mixtures of th~ foreyoing of an avera~e molecular weight of about 600 to about 6,000, and aIkoxylated arcm~tic alcohols ha~ing a molecular weight ranging from about 300 to 2500. Ex~mplary of such preferred polyether bri~htening compounds which can satisfactorily be en~loyed are polyethylene glycols of an average molecular weight of from about 400 to about 1,000,000;
ethoxylated naphthols containing 5 to 45 mols ethylene oxide groups; pr~poxylated naphthols containing 5 to 15 mols of propylene oxide groups; ethoxylated nonyl phenol containing 5 to 30 nmols ethylene oxide groups; propylene glycols of an average molecular weigh-t of about 350 to about 1,000; block polymers of polyoxyethylene and polyoxypropylene glycols of an average mole~ular weight of abou-t 350 to 250,000; ethoxylated phenols containing 5 to 100 mols of ethylene oxide groups; propoxylated phenols containing 5 to 15 mols of propylene oxide groups, and ethylene diamune block polymers having a molecular weight of about 1600 -to about 30,000. Additional polyether compounds suitable for use in the practice of the present process are those disclosed in United States Patent No. 4,272,335.
me polyether brightening compounds are employed in a range of about 0.001 up to about 5 g/l with the lower concentrations generally being used with the higher molecular weight polyethers.
Organic sulfide brightening compounds which can be satisfactorily employed in the practice of the present process include the various sulfonate organic sulfide compounds as described in United Sta-tes PaTENT ~o. 3,267,010, and particularly Table I thereof; organic sulfur compounds as disclosed in United States Patent No. 4,181,582 and particularly Table III thereof;
and the organic polysulfide compounds as disclosed in United States Patent No. 3,328,273 and particularly Table I thereof. The organic sulfide compcunds containing sulfonic or phosphonic groups may also contain various substituent groups, such as methyl, chloro, bromo, methoxy, ethoxy, carboxy or hydroxy, on the m~lecules, especially on the aromatic and heterocyclic sulfide-sulfonic or phosphonic acids. Such ccm~ounds may be used as the free acids r the alkali metal salts, organic amune salts, or the like.
Cther suitable organic divalent sulfur cc~ounds which can be satisfactorily used include HO3P-(CH2)3-S-S-(CH2)3-PO3H, as well as merca~tans, thiocarbHmates, thiolcarbamates, thioxanthates, and thiocarbonates which contain at least one sulfonic or phosphonic group.
A particularly preferred group of organic divalent sulfur compounds as described in U.S. Patent No. 3,328,273 are the organic polysulfide compounds of the formula XRl~(S)nR2S3H or ~ ~~S)n~2P3H wherein ~ and ~ are the same or different aIkylene group containing from ,~
about 1 to 6 cæbon atoms, X is hydrogen, SO3H or PO3H and n is a number frcm about 2 to 5. mese organic divalent sulfur compounds are aliphatic polysulfides wherein at least t~,~
divalent sulfur atoms are vicinal and wherein the molecule has one or two terminal sulfonic or phosphonic acid groups. The alkylene portion of the molecule may be substituted with groups such as methyl, ethyl, chloro, bromo, ethoxy, hydroxy, and the like. mese ccmpounds may be added as the free acids or as the aIkali metal or amine salts.
me organic sulfide brightening compound or mixture of compounds are present in the electrolyte within a range of about 0.0005 to about 1 g/l.
In accordance with the process aspects of the present nvention, an aqueous acidic copper electrolyte of the foregoing composition is employed in which an electrically conductive substrate is immersed and is cathodically charged for a period of time to deposit the desired thickness of copper thereon. During the electroplating operation, the bath is controlled at a temperature of frcm about 15 up to about 50C and at cathode current densities ranging from as low as about 0.5 to as high as about 400 ASF, preferably from about 10 to about 100 ASF.
Particularly satisfactory results are obtained at bath temperatures of about 20 to about 36C at current densities of about 10 to about 50 ASF.
~5~
In order to further illustrate the present in~Jention, the follc~ing typical examples are provided. It will be appreciated that the examples are provided for illustrative purposes and are not intended to be limiting of the scope of the present invention as herein described and as set forth in the subjoined claims.
EX~LE 1 An aqueous acidic copper electrolyte is prepared containing akout 165 to about 225 g/l copper sulfate pentahydrate, about 42 to about 75 g/l sulfuric acid and about O.04 to about 0.1 g/l chloride ions. Tb the foregoing aqueous solution, 3 mg/l of Methic Ttrq~loise comprising the phthalocyanine brightening agent is added along with 3 mg/l of diethyl apo safranine. As supplemental brightening agents, the bath further contains 50 mg/l of polypropylene glycol of an average molecular weight of 700 and 20 mg/l of Bis (3-sulfopropyl disulfide disodium salt).
An operation of the bath at a current density of from about 0.5 to about 100 ASF at a temperature of from about 70 to about 80F produced highly leveled, fine-grained copper desposits with no physical defects.
EXPMæLE 2 An aqueous acidic copper electrolyte is prepared containing about 165 to about 225 g/l copper sulfate pentahydrate, about 42 to about 75 g/l sulfuric acid and about s~
0.04 to about 0.1 g/1 chloride ions. To the foregoing aqueous solution, 3 mg/l of Methic Turquoise cGmprising the phthalocyanine brightening agent is added along with 60 mg/1 of a block polymer of ethylene propylene oxide (mol wt. 3000), 20 mg/l of Bis (3-sulfopropyl disulfide disodium salt) and 1.5 mg/l of the reaction product of polyethylene imine (mol wt. 600) with benzyl chloride as supplemental brightening agents.
The operation of the bath at a temperature of from about 70 to about 80F and at current densities of about 20 to about 80 ASF produces bright, leveled copper deposits. The further addition of 3 mg/l of diethyl apo safranine to the electrolyte results in a dramatic improvement in the leveling characteristics of the deposit and also substantially improves the brightness in the low current density areas of test panels employing ~he same plating parameters.
EXAMæLE 3 An aqueous acidic copper electrolyte is prepared containing about 165 to about 225 g/1 copper sulfate pentahydrate, about 42 to about 75 g/l sulfuric acid and about 0.04 to about 0.1 g/l chloride ions. To the foregoing aqueous solution, 2 mg/l of diethyl apo safranine is added in further ccmbination with supplemental brightening agents ccmprising 20 mg/l Bis (3-sulfcpropyl disulfide disodium salt), 200 mg~l polyethylene oxide (mol wt. 6000) and 1.5 mg/1 of a reaction product of polyethyleneimine (mol wt. 600) reacted with ben~yl chloride.
The foregoing electrolyte produces a bright, leveled copper deposit when plated on a J-shaped test panel at an average current density of about 50 ASF for a period of 15 minutes but t~e deposit is striated in the low curxent density area. The addition of 3 mg/l of Methic Turquoise ccmprising the substituted phthalocyanine radical brightening agent to the electxolyte results in the elimlnation of the striations in the lcw current density area of the J-type test panel plated under the same conditions without any loss of brightness and leveling of the copper deposit.
While it will be apparent that the preferred embodiments of the invention disclosed are well calculated to fulfill the objects above stated, it will be appreciated that the invention is susceptible to modification, variation and change without departing frcm the proper scope or fair meaning of the subjoined claims.
Claims (18)
1. An aqueous acidic electrolyte containing copper in an amount sufficient to electrodeposit copper on a substrate, the improvement comprising incorporating in said electrolyte a brightening amount sufficient to produce a bright, leveled and ductile copper electrodeposit of a combination of brightening agents comprising:
(a) a bath soluble, substituted phthalocyanine compound represented by the formula:
Pc-(X)n Wherein:
Pc is a phthalocyanine radical;
X is -SO2NR2,-SO3M,-CH2SC(NR2)2+Y-;
R is H, alkyl containing 1-6 carbon atoms, aryl containing 6 carbon atoms, aralkyl containing 6 carbon atoms in the aryl portion and 1 to 6 carbon atoms in the alkyl portion, heterocyclic containing 2 to 5 carbon atoms and at least 1 nitrogen, oxygen, sulfur or phosphorus atom, and alkyl, aryl, aralkyl and heterocyclic, as defined above, containing 1 to 5 amino, hydroxy, sulfonic or phosphonic groups;
n is 1-6;
Y is halogen or alkyl sulfate containing 1 to 4 carbon atoms in the alkyl portion; and M is H, Li, Na, K or Mg; and (b) an apo safranine compound represented by the formula:
Wherein the R' are the same or different and comprise -CH3, -C2H5 or -C3H7, and X' is an anion selected from the group consisting of chloride, bromide, iodide, fluoride, sulfate, bisulfate and nitrate.
(a) a bath soluble, substituted phthalocyanine compound represented by the formula:
Pc-(X)n Wherein:
Pc is a phthalocyanine radical;
X is -SO2NR2,-SO3M,-CH2SC(NR2)2+Y-;
R is H, alkyl containing 1-6 carbon atoms, aryl containing 6 carbon atoms, aralkyl containing 6 carbon atoms in the aryl portion and 1 to 6 carbon atoms in the alkyl portion, heterocyclic containing 2 to 5 carbon atoms and at least 1 nitrogen, oxygen, sulfur or phosphorus atom, and alkyl, aryl, aralkyl and heterocyclic, as defined above, containing 1 to 5 amino, hydroxy, sulfonic or phosphonic groups;
n is 1-6;
Y is halogen or alkyl sulfate containing 1 to 4 carbon atoms in the alkyl portion; and M is H, Li, Na, K or Mg; and (b) an apo safranine compound represented by the formula:
Wherein the R' are the same or different and comprise -CH3, -C2H5 or -C3H7, and X' is an anion selected from the group consisting of chloride, bromide, iodide, fluoride, sulfate, bisulfate and nitrate.
2. The electrolyte as defined in claim 1 wherein said phthalocyanine brightening agent comprises from about 35 percent to about 80 percent by weight of the total amount of the combination of brightening agents (a) and (b) present in the electrolyte.
3. The electrolyte as defined in claim 1 in which the combination of brightening agents (a) and (b) are present within a range of about 0.0005 to about 1 g/l.
4. The electrolyte as defined in claim 1 wherein the combination of brightening agents (a) and (b) are present in an amount of about 0.002 to about 0.01 g/l.
5. The electrolyte as defined in claim 3 in which said phthalocyanine brightening agent (a) comprises from about 35 percent to about 80 percent by weight of the combination of brightening agents (a) and (b) present.
6. The electrolyte as defined in claim 4 wherein said phthalocyanine brightening agent (a) comprises from about 35 percent to about 80 percent by weight of the combination of brightening agents (a) and (b) present.
7. The electrolyte as defined in claim 1 further including a supplemental brightening agent comprising a bath soluble and compatible polyether compound present in an amount of about 0.001 to about 5 g/l.
8. The electrolyte as defined in claim 1 further including a supplemental brightening agent comprising a bath soluble and compatible organic sulfide compound present in an amount of about 0.0005 to about 1 g/l.
9. The electrolyte as defined in claim 1 wherein said phthalocyanine brightening agent comprises Methic Turquoise.
10. The electrolyte as defined in claim 1 wherein said apo safranine compound brightening agent comprises diethyl apo safranine.
11. The electrolyte as defined in claim 1 wherein said phthalocyanine brightening agent comprises Methic Turquoise and said apo safranine compound brightening agent comprises diethyl apo safranine.
12. The electrolyte as defined in claim 1 further containing halide ions in an amount up to about 0.5 g/l.
13. A process for electrodepositing a bright, leveled copper deposit on a conductive substrate which comprises the steps of immersing a cathodically charged conductive substrate in the electrolyte of claim 1 and electrodepositing a copper plate on said substrate to the desired thickness.
14. The process as defined in claim 13 including the further step of controlling the temperature of the electrolyte within a range of about 15° to about 50°C.
15. The process as defined in claim 13 including the further step of controlling the temperature of the electrolyte to within a range of about 20° to about 36°C.
16. The process as defined in claim 13 including the further step of controlling the current density during the step of electrodepositing a copper plate on said substrate within a range of about 0.5 to about 400 ASF.
17. The process as defined m claim 13 including the further step of controlling the current density during the step of electrodepositing a copper plate on said substrate within a range of about 10 to about 100 ASF.
18. The process as defined in claim 13 including the further steps of controlling the temperature of said electrolyte within a range of about 20° to about 36°C and the average current density during the step of electrodepositing the copper plate on the substrate within a range of about 10 to about 50 ASF.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US50121183A | 1983-06-10 | 1983-06-10 | |
| US501,211 | 1983-06-10 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1255621A true CA1255621A (en) | 1989-06-13 |
Family
ID=23992559
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000456108A Expired CA1255621A (en) | 1983-06-10 | 1984-06-07 | Copper electrodeposition with substituted phthalocyanine and an apo safranine |
Country Status (10)
| Country | Link |
|---|---|
| JP (1) | JPS6013090A (en) |
| AU (1) | AU554236B2 (en) |
| BR (1) | BR8402811A (en) |
| CA (1) | CA1255621A (en) |
| DE (1) | DE3420999A1 (en) |
| ES (1) | ES8601336A1 (en) |
| FR (1) | FR2547318B1 (en) |
| GB (1) | GB2141140B (en) |
| IT (1) | IT1177785B (en) |
| NL (1) | NL8401841A (en) |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE4126502C1 (en) * | 1991-08-07 | 1993-02-11 | Schering Ag Berlin Und Bergkamen, 1000 Berlin, De | |
| JPH10330983A (en) | 1997-05-30 | 1998-12-15 | Fukuda Metal Foil & Powder Co Ltd | Electrolytic copper foil and its production |
| DE19758121C2 (en) * | 1997-12-17 | 2000-04-06 | Atotech Deutschland Gmbh | Aqueous bath and method for electrolytic deposition of copper layers |
| DE10261852B3 (en) | 2002-12-20 | 2004-06-03 | Atotech Deutschland Gmbh | Mixture of di-, tri- and other oligomeric phenazinium compounds, used in copper electroplating bath for decorative plating or plating circuit board or semiconductor substrate, is prepared from monomer by diazotization and boiling |
| DE10337669B4 (en) * | 2003-08-08 | 2006-04-27 | Atotech Deutschland Gmbh | Aqueous, acid solution and process for the electrodeposition of copper coatings and use of the solution |
| JP4644447B2 (en) * | 2004-06-25 | 2011-03-02 | 株式会社日立製作所 | Method for manufacturing printed wiring board |
| GB0520793D0 (en) * | 2005-10-13 | 2005-11-23 | Avecia Inkjet Ltd | Phthalocyanine inks and their use in ink-jet printing |
Family Cites Families (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| NL83873C (en) * | 1952-05-26 | |||
| NL174178B (en) * | 1952-05-26 | Chevron Res | PROCEDURE FOR THE RECOVERY OF HYDROCARBONS FROM A PERMEABLE HYDROCARBON FORMATION BY INJECTION WITH STEAM. | |
| US2738318A (en) * | 1954-12-28 | 1956-03-13 | Udylite Res Corp | Electrodeposition of copper from an acid bath |
| US2882209A (en) * | 1957-05-20 | 1959-04-14 | Udylite Res Corp | Electrodeposition of copper from an acid bath |
| NL291575A (en) * | 1962-04-16 | |||
| US3328273A (en) * | 1966-08-15 | 1967-06-27 | Udylite Corp | Electro-deposition of copper from acidic baths |
| US3770598A (en) * | 1972-01-21 | 1973-11-06 | Oxy Metal Finishing Corp | Electrodeposition of copper from acid baths |
| BE833384A (en) * | 1975-03-11 | 1976-03-12 | COPPER ELECTRODEPOSITION | |
| DE2746938A1 (en) * | 1977-10-17 | 1979-04-19 | Schering Ag | ACID GALVANIC COPPER BATH |
| US4272335A (en) * | 1980-02-19 | 1981-06-09 | Oxy Metal Industries Corporation | Composition and method for electrodeposition of copper |
| US4336114A (en) * | 1981-03-26 | 1982-06-22 | Hooker Chemicals & Plastics Corp. | Electrodeposition of bright copper |
-
1984
- 1984-06-04 AU AU29033/84A patent/AU554236B2/en not_active Ceased
- 1984-06-06 DE DE19843420999 patent/DE3420999A1/en active Granted
- 1984-06-07 JP JP59117435A patent/JPS6013090A/en active Granted
- 1984-06-07 CA CA000456108A patent/CA1255621A/en not_active Expired
- 1984-06-08 IT IT48351/84A patent/IT1177785B/en active
- 1984-06-08 ES ES533252A patent/ES8601336A1/en not_active Expired
- 1984-06-08 FR FR848409048A patent/FR2547318B1/en not_active Expired - Lifetime
- 1984-06-08 BR BR8402811A patent/BR8402811A/en unknown
- 1984-06-08 NL NL8401841A patent/NL8401841A/en not_active Application Discontinuation
- 1984-06-11 GB GB08414862A patent/GB2141140B/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| GB2141140B (en) | 1986-12-10 |
| JPS6013090A (en) | 1985-01-23 |
| JPS6112036B2 (en) | 1986-04-05 |
| NL8401841A (en) | 1985-01-02 |
| DE3420999A1 (en) | 1984-12-13 |
| BR8402811A (en) | 1985-05-21 |
| IT1177785B (en) | 1987-08-26 |
| GB8414862D0 (en) | 1984-07-18 |
| IT8448351A0 (en) | 1984-06-08 |
| AU2903384A (en) | 1984-12-13 |
| AU554236B2 (en) | 1986-08-14 |
| GB2141140A (en) | 1984-12-12 |
| FR2547318A1 (en) | 1984-12-14 |
| DE3420999C2 (en) | 1987-10-15 |
| ES533252A0 (en) | 1985-10-16 |
| FR2547318B1 (en) | 1990-05-04 |
| ES8601336A1 (en) | 1985-10-16 |
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