CA1083303A - Electroless copper plating solutions - Google Patents
Electroless copper plating solutionsInfo
- Publication number
- CA1083303A CA1083303A CA270,026A CA270026A CA1083303A CA 1083303 A CA1083303 A CA 1083303A CA 270026 A CA270026 A CA 270026A CA 1083303 A CA1083303 A CA 1083303A
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- CA
- Canada
- Prior art keywords
- formaldehyde
- copper plating
- mole
- plating bath
- copper
- 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.)
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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
- C23C18/38—Coating with copper
- C23C18/40—Coating with copper using reducing agents
- C23C18/405—Formaldehyde
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- Chemical & Material Sciences (AREA)
- General Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Chemically Coating (AREA)
Abstract
ABSTRACT:
Electroless copper plating bath con-taining a copper salt, a complexing agent, alkali and by way of reducing agent a complex of formalde-hyde with an aminocarboxylic acid, -sulphonic acid or -phosphonic acid. Consequently, decomposition of the bath is greatly reduced and furthermore copper of a superior quality is obtained.
Electroless copper plating bath con-taining a copper salt, a complexing agent, alkali and by way of reducing agent a complex of formalde-hyde with an aminocarboxylic acid, -sulphonic acid or -phosphonic acid. Consequently, decomposition of the bath is greatly reduced and furthermore copper of a superior quality is obtained.
Description
PIIN 82~9 - LOOP/Jl,l,~l/CB
10.12.1976 1~833(~3 ~lcctroless copper plating solutions.
The invention relates to electroless aqueous copper plating solutions.
As a rule electroless copper plating r~ GcJpr; ~
solutions comprise ~-ions, one or more compounds wllich form a complex with cupric ions and as a rule formaldehyde or a compound ~hich furnishes formaldehyde as a reducing agent. }Iere-with the reduction of~cupric ions to metal can only take place in an alkaline medium,preferably in the plI-range between 12 and 13.
United States Patent Specification 3J615,732 discloses such an alkaline solution by means of which good, ductile copper can be deposi-ted on metal nuclei layers which may have been hbtainecl either chemically or photographically and which act as a catalyst for the copper deposition. In accor-dance with this patent specification the inclusion of hydrogen during the decomposition reaction of an electroless copper plating bath is prevented and hereby the ductivility of the deposited copper is improved by the addition of a compound which furnishes with formaldehyde an addition-product such as a sulphite, a bisulphite or a phosphite. An electroless copper plating bath comprises as essential constituents a soluble cupric salt, alkali for adjusting the p}I, one - :.. .. . ; .
Pll~ 8289 10.12.l()7G
~83303 or more complex:ing agents for cupric ions, formaldellyde or a compouncl wh:ich ~urnisl1es formaldehyde and, pre:rerably, also a polyo~yal-kylene compound.
An annoying property of formaldehyde ..is th.at in an al.kaline medium it is subjected to side reactions so that the greater part is lost for a reduction reaction fron1 cupric ions to copper metal`
Cu+~ + 2 MClI0 + I~OH ~ Cu + 2HC00 + 21I20 + 112 An unwanted side reaction is the so-called Cannizzaro reaction, in which formate is formed according to
10.12.1976 1~833(~3 ~lcctroless copper plating solutions.
The invention relates to electroless aqueous copper plating solutions.
As a rule electroless copper plating r~ GcJpr; ~
solutions comprise ~-ions, one or more compounds wllich form a complex with cupric ions and as a rule formaldehyde or a compound ~hich furnishes formaldehyde as a reducing agent. }Iere-with the reduction of~cupric ions to metal can only take place in an alkaline medium,preferably in the plI-range between 12 and 13.
United States Patent Specification 3J615,732 discloses such an alkaline solution by means of which good, ductile copper can be deposi-ted on metal nuclei layers which may have been hbtainecl either chemically or photographically and which act as a catalyst for the copper deposition. In accor-dance with this patent specification the inclusion of hydrogen during the decomposition reaction of an electroless copper plating bath is prevented and hereby the ductivility of the deposited copper is improved by the addition of a compound which furnishes with formaldehyde an addition-product such as a sulphite, a bisulphite or a phosphite. An electroless copper plating bath comprises as essential constituents a soluble cupric salt, alkali for adjusting the p}I, one - :.. .. . ; .
Pll~ 8289 10.12.l()7G
~83303 or more complex:ing agents for cupric ions, formaldellyde or a compouncl wh:ich ~urnisl1es formaldehyde and, pre:rerably, also a polyo~yal-kylene compound.
An annoying property of formaldehyde ..is th.at in an al.kaline medium it is subjected to side reactions so that the greater part is lost for a reduction reaction fron1 cupric ions to copper metal`
Cu+~ + 2 MClI0 + I~OH ~ Cu + 2HC00 + 21I20 + 112 An unwanted side reaction is the so-called Cannizzaro reaction, in which formate is formed according to
2 HCH0 + OH ~ CII30M + HC00 .
Besides that the so-called aldol condensation takes place which al-,o contributes to the ~ loss of formaldehyde from the solution.
The above formaldehyde addition products decompose substantially completely in an alkaline medium so that the disadvantage of the occurrence of the above-mentioned side reactions remains.
Consequently, when the copper plating baths are used - continuously much more formaldehyde must be added than is in accordance with`the reaction which is responsible for the copper deposition.
: , . :., :.:. .. , :
" ,. - , P]IN 828'3 1083~3 10.12.1976 It is an object of the invention to provide a composition oi' the bath in which the unwallted reactions do not occur anymore or are reduced to such an extent that they are no longer amloying.
The electroless copper plating bath of the composition defined hereinbefore is characterized in that the bath furthermore contains one or more salts of non-bivalent sulphur containing aminoalkylcarboxyllc acids, aminoalkylsulphonic acid/or aminoalkylphosphollic acids with at least one free - NH2 group, predominantly in the ~orm of an addition product with formaldehyde via said -NH2 groups and in a quantity ~rhich preferably is at the utmost molarly equal to the quantity of formal-dehyde presènt.
The addition compound discussed here is formed in the copper plating solution by adding an aminoacid and the formaldehyde as such. The compound ` may also be prepared separately, for example according to OH
H-C ~ ~ ~ ~ H C / CH2 H
at a pH of over 7.
The presence of the above-said addition product has in the first place the advantage that the undesired Cannizz,aro reaction is reduced to a non-annoying level.
Pl-IN 8X~
10.1~.1970 ~al83303 By ~ay of illustration two experlme.1lts are discussed here. According -to the first eXperimellts a solution of 1.5 mol/l formaldellyde-bisulphite compound to ~h.;ch NaO.lI is added to a pH = 12.8 is heated for 5.5 hours at 52C. Accord:ing to the second exper:iment a solutinn of 1.5 mol of th.e addition product glycine-formaldehyde ~ith NaOH to pH = 12.8 is heated at 600C for 6.5 hours. In the first experi.-menl; ~0 a/~ of the forl1laldehyde is converted into for-mnte nnd in the second e~periment less than 1 a~. Thedeterm.inatiol1 of formate is done by me~ns of proton magnetic resonance (nmr) by measuri.ng the formate proton. In these experiments the Cu++ has been omittec1 from the solution because the paramagnetic Cu++ is a disturbing factor in the nmr-determination.
During use the bath according to the invention is replenished by the addition of formal-dehyde .
A further advantage o~ the addition according to the invention is a good quality of thecopper deposited therefrom as regards ductivility.
That this is caused by the presence of amino acids or addition products is the ~ore surprising because in general hydrogen-containing compounds such as urea, pyridine or quarternary ammonium compounds give inferior copper deposits.as regards appearance and ductility.
Pl-TN 82~9 1~833~3 lo. 12.1976 The increased stabili-ty of the reducin~
agent reduces the formation of by-products. Especially the fact that less salt is :formed is o~ very great importance ~or a production bath ~hich is in conti-nuous operation.
A p]easant additional advantage oC the bath according to the inven-tion is that the unpleasant smell o~ the formaldehyde is substantially not noticeable.
In accordance with the invention the bath contains one or more salts o~ amino acids having at least one ~ree -NH2 group in the form o~ the addition compound with formaldehyde in which the grouping -~I-CH20H is present.
Compounds with other nitrogen groups such as amides, amines, urea compounds or peptides show no ef~ect or even impair the quality o~ the deposited copper. Also amino acids which contain bivalent sulphur must not be used because they result in poisoning o~ the copper sur~ace.
It should be noted that, for example, in the DT-OS 2.051.279 glycine is mentioned amongst a large number o~ complexing agents ~or cupric ions in electroless copper plating baths. However, in the copper plating bath according to the invention an other complexing agent is invariably present, whilst besides that an amino acid in a quantity to the pll~ 82 10.1~.l97 1~83303 stoiehiometrieal proportion with forma:Lclellyde is adcled.
The presenee in the bath accordillg to the invention of one or more polyo~yalkylene compouncls, as is l~lo~rn per se from British Patent Specification 1.330.332 has an extra favourable effect in combination with the amino aeid whieh implies a preferred embodimen-t of the bath according to the invention.
~ praetieally very interes-ting pre-ferred embodiment is an electroless copper plating ba-th hav:ing the tetrasodiumsalt of ethylenediaminete-tra-acetic aeid as a eomplexing agent for cupric ions and glycine to form an addition compound with formaldehyde.
The eopper plating bath according to the invention is prepared in such a way that the salts of the aminoalkylearbo~ylie aeid, -sulphonie aeid or -phosphonie aeid and the formaldehyde are added separa-tely in qualltities wherein the salt preferably is, at the utmost, molarly equal to the quantity of formal-dehyde.
During use the quantity of formaldehyde gradually deereases but when the bath is replenished this quantity must be brought to the original level again.
The invention will now be further explained with referencè to a few embodiments.
10.12.1976 1~83303 EXA~IPLE I:
Glass plates, roughened on one sicle with carborundum were activated for the electroless copper deposition by moving thelll first ror 2 minu-tes at ambient tempera-ture in a solutinn of 50 g tin (II) chloride and 10 ml of a concentrated hydrochlorid acid solution in 1 litre of deionised water, by keeping thelll for 15 seconds in running de-ionised water~
~y l~loving them ~or 1 minute in a solution of 0025 g ~dCl2 and 10 ml of a-concentrated ~ICl so-lution~in one litre of dionised water and by finally moving them again for half a minute in running dionised water.
These operations were repeated a second time wherein the glass plates were moved for 45 seconds in the tin (II) chlo~ide solution and for 30 seconds in the PdCl2 solution. Thereafter the glaSs plates were processed for a further 30 seconds with an aqueous solution of 50 C which contains per litre 0.10 mole NaOH and 0.10 mol formaldehyde and immediately thereafter rinsed for 15 seconds in deionised water of 50C. The plates nucleated in this manner were therea~ter subjected to electroless plating in a solution which was hea-ted to 600C and ~Yhich contains the following constituents per litre :
o.o6 mole CuSOI~.5H20 o.o66 mole tetrasodiumsalt o~ ethylenediamine-tetra-acetic acid ~83303 0.15 mole hydroxymethylaminopotassium acetate (addition product of formaldehyde and glycine) and approximately 0.10 mole NaOH to pH 12.5.
After 5 1/2 hours approximately 13/um of copper was deposited on the glass plate. The ductility of the deposited copper layer was 2 1/2 bends. If instead of 0.15 mole of the addition product 0.15 mole of free formaldehyde was added (the pH was 12.5 again) the solution was unstable and brittle copper was deposited on the glass plate.
E~AMPLE II.
Glass plates which were nucleated in accordance with example I were strengthened at 50 C in a solution (A) which contains per litre :
0.06 mole CuS04.5H20 0.066 mole tetrasodiumsalt of ethylenediaminetetra-acetic acid approximately 0.10 mole NaOH to adjust the pH
to 12.6 0.10 % by weight of the polyoxy compound "Triton"
QS44 (trade mark) 0.15 mole hydroxymethylaminopotassium acetate.
"Triton" QS44 is an anionic phosphate ester having approximately 8 ethyleneoxide groups (molar weight approximately 800), and is supplied by Rohm and - Haas.
`~
... . . ..
10.12.1976 The addition product is added in the rorm o~ a
Besides that the so-called aldol condensation takes place which al-,o contributes to the ~ loss of formaldehyde from the solution.
The above formaldehyde addition products decompose substantially completely in an alkaline medium so that the disadvantage of the occurrence of the above-mentioned side reactions remains.
Consequently, when the copper plating baths are used - continuously much more formaldehyde must be added than is in accordance with`the reaction which is responsible for the copper deposition.
: , . :., :.:. .. , :
" ,. - , P]IN 828'3 1083~3 10.12.1976 It is an object of the invention to provide a composition oi' the bath in which the unwallted reactions do not occur anymore or are reduced to such an extent that they are no longer amloying.
The electroless copper plating bath of the composition defined hereinbefore is characterized in that the bath furthermore contains one or more salts of non-bivalent sulphur containing aminoalkylcarboxyllc acids, aminoalkylsulphonic acid/or aminoalkylphosphollic acids with at least one free - NH2 group, predominantly in the ~orm of an addition product with formaldehyde via said -NH2 groups and in a quantity ~rhich preferably is at the utmost molarly equal to the quantity of formal-dehyde presènt.
The addition compound discussed here is formed in the copper plating solution by adding an aminoacid and the formaldehyde as such. The compound ` may also be prepared separately, for example according to OH
H-C ~ ~ ~ ~ H C / CH2 H
at a pH of over 7.
The presence of the above-said addition product has in the first place the advantage that the undesired Cannizz,aro reaction is reduced to a non-annoying level.
Pl-IN 8X~
10.1~.1970 ~al83303 By ~ay of illustration two experlme.1lts are discussed here. According -to the first eXperimellts a solution of 1.5 mol/l formaldellyde-bisulphite compound to ~h.;ch NaO.lI is added to a pH = 12.8 is heated for 5.5 hours at 52C. Accord:ing to the second exper:iment a solutinn of 1.5 mol of th.e addition product glycine-formaldehyde ~ith NaOH to pH = 12.8 is heated at 600C for 6.5 hours. In the first experi.-menl; ~0 a/~ of the forl1laldehyde is converted into for-mnte nnd in the second e~periment less than 1 a~. Thedeterm.inatiol1 of formate is done by me~ns of proton magnetic resonance (nmr) by measuri.ng the formate proton. In these experiments the Cu++ has been omittec1 from the solution because the paramagnetic Cu++ is a disturbing factor in the nmr-determination.
During use the bath according to the invention is replenished by the addition of formal-dehyde .
A further advantage o~ the addition according to the invention is a good quality of thecopper deposited therefrom as regards ductivility.
That this is caused by the presence of amino acids or addition products is the ~ore surprising because in general hydrogen-containing compounds such as urea, pyridine or quarternary ammonium compounds give inferior copper deposits.as regards appearance and ductility.
Pl-TN 82~9 1~833~3 lo. 12.1976 The increased stabili-ty of the reducin~
agent reduces the formation of by-products. Especially the fact that less salt is :formed is o~ very great importance ~or a production bath ~hich is in conti-nuous operation.
A p]easant additional advantage oC the bath according to the inven-tion is that the unpleasant smell o~ the formaldehyde is substantially not noticeable.
In accordance with the invention the bath contains one or more salts o~ amino acids having at least one ~ree -NH2 group in the form o~ the addition compound with formaldehyde in which the grouping -~I-CH20H is present.
Compounds with other nitrogen groups such as amides, amines, urea compounds or peptides show no ef~ect or even impair the quality o~ the deposited copper. Also amino acids which contain bivalent sulphur must not be used because they result in poisoning o~ the copper sur~ace.
It should be noted that, for example, in the DT-OS 2.051.279 glycine is mentioned amongst a large number o~ complexing agents ~or cupric ions in electroless copper plating baths. However, in the copper plating bath according to the invention an other complexing agent is invariably present, whilst besides that an amino acid in a quantity to the pll~ 82 10.1~.l97 1~83303 stoiehiometrieal proportion with forma:Lclellyde is adcled.
The presenee in the bath accordillg to the invention of one or more polyo~yalkylene compouncls, as is l~lo~rn per se from British Patent Specification 1.330.332 has an extra favourable effect in combination with the amino aeid whieh implies a preferred embodimen-t of the bath according to the invention.
~ praetieally very interes-ting pre-ferred embodiment is an electroless copper plating ba-th hav:ing the tetrasodiumsalt of ethylenediaminete-tra-acetic aeid as a eomplexing agent for cupric ions and glycine to form an addition compound with formaldehyde.
The eopper plating bath according to the invention is prepared in such a way that the salts of the aminoalkylearbo~ylie aeid, -sulphonie aeid or -phosphonie aeid and the formaldehyde are added separa-tely in qualltities wherein the salt preferably is, at the utmost, molarly equal to the quantity of formal-dehyde.
During use the quantity of formaldehyde gradually deereases but when the bath is replenished this quantity must be brought to the original level again.
The invention will now be further explained with referencè to a few embodiments.
10.12.1976 1~83303 EXA~IPLE I:
Glass plates, roughened on one sicle with carborundum were activated for the electroless copper deposition by moving thelll first ror 2 minu-tes at ambient tempera-ture in a solutinn of 50 g tin (II) chloride and 10 ml of a concentrated hydrochlorid acid solution in 1 litre of deionised water, by keeping thelll for 15 seconds in running de-ionised water~
~y l~loving them ~or 1 minute in a solution of 0025 g ~dCl2 and 10 ml of a-concentrated ~ICl so-lution~in one litre of dionised water and by finally moving them again for half a minute in running dionised water.
These operations were repeated a second time wherein the glass plates were moved for 45 seconds in the tin (II) chlo~ide solution and for 30 seconds in the PdCl2 solution. Thereafter the glaSs plates were processed for a further 30 seconds with an aqueous solution of 50 C which contains per litre 0.10 mole NaOH and 0.10 mol formaldehyde and immediately thereafter rinsed for 15 seconds in deionised water of 50C. The plates nucleated in this manner were therea~ter subjected to electroless plating in a solution which was hea-ted to 600C and ~Yhich contains the following constituents per litre :
o.o6 mole CuSOI~.5H20 o.o66 mole tetrasodiumsalt o~ ethylenediamine-tetra-acetic acid ~83303 0.15 mole hydroxymethylaminopotassium acetate (addition product of formaldehyde and glycine) and approximately 0.10 mole NaOH to pH 12.5.
After 5 1/2 hours approximately 13/um of copper was deposited on the glass plate. The ductility of the deposited copper layer was 2 1/2 bends. If instead of 0.15 mole of the addition product 0.15 mole of free formaldehyde was added (the pH was 12.5 again) the solution was unstable and brittle copper was deposited on the glass plate.
E~AMPLE II.
Glass plates which were nucleated in accordance with example I were strengthened at 50 C in a solution (A) which contains per litre :
0.06 mole CuS04.5H20 0.066 mole tetrasodiumsalt of ethylenediaminetetra-acetic acid approximately 0.10 mole NaOH to adjust the pH
to 12.6 0.10 % by weight of the polyoxy compound "Triton"
QS44 (trade mark) 0.15 mole hydroxymethylaminopotassium acetate.
"Triton" QS44 is an anionic phosphate ester having approximately 8 ethyleneoxide groups (molar weight approximately 800), and is supplied by Rohm and - Haas.
`~
... . . ..
10.12.1976 The addition product is added in the rorm o~ a
3.5 mole aqueous solution of pII 12.8. After 6 hours approximately 11/um of copper hacl been deposited on the glass plate. The ductility of 5 the copper layer was ~ bends. For comparison a solution (B) was made in wIIich -the addition product was replaced by a concentration o~ free formaldehyde of 0.02 mol/l so that the rate of deposition during one hour had the same value and which, as regards the other constituents of the bath was identical to the above solution. ~ith both solutions, each in a volume of 200 ml, one solution having a addition product of ~ormaldehyde and glycine, the other having free formaldehyde, copper was depo-sited on nucleated glass plates in accordance withexample I (surface area 5.9 cm2) at a temperature of 50C for various working days of 6 Hours each.
After each day the quantity of cupric ions used up was determined and added again. After the original pH was ad~usted copper was thereafter again deposited on new nucleated glass plates. In this manner the exhaustion as regards formaldehyde could be studied.
The quantities of copper per hours deposited with the two solutions had the following values :
¦ solution A l solutio~ B
1st day I 1.3 mg/cm2 hour ' 1.3 mg/cm2 hour _ .____. __ _.. ___ .. _ _._.. __ .. __ .~.. __ __ .. _ .. _. _ . . ___ _ i 2nd day j 1.1 mg/cm2 hour 1 0.5 mg/cm2 hour 3rd day ~ 1.1 mg/cm2 hour ~ 0.15mg/cm2 hour , - - ... ~ ~, - . .. . . . . . . ..
P]-~N 8289 lo. 12. 1976 EXA~IP1,~ III
Nucleated glass plates in acco:rdance w:ith ~xample I were electroless copper plated at a tempera-ture of 52~C in solutions which contained per litre the following constituents :
o.o6 mole cus04.5H20 o . o66 mole tetrasodiwnsal-t of ethylenediamine-tetra-acetic acid NaO~I to the required pH
a) varying concentrations in mole/l of hydroxymethyl-aminopotassium acetate b) varying concentrations in mole/l of free formal-dehyde.
The quantities of copper deposited per hour were as follo~s :
Conc.A¦ pH - - ~-~-~ -~ , pH 12,6 lonc ~ pH 12,4 . . ____ ______ _._~ . . _, .. .~.._ __ ._ .. _ _ _ __ _l 0,10 3,4 m,g/cm2.hour 4,0mg/cm2.hou~ 0,01,0,4mg/cm2.hour 0,20 3,6 mg/cm2.llour 4,6mg/cm2.hour!0,02 2,4mg/cm2.hour 0,30 3,6 mg/cm2.hour 4,7mg/cm2.hour10,03 j3,7mg/cm2.hour .5 3,5 mg/cm2.hour14,7mg/cm2.hour`0,04 ~,7mg/cm2.hour _ .. _ __ _ . _. ._._ ___ ,. _ _ _ _ _ _ _ ,, __ _ ,,_ , , _ _, ,, _, _ _ ,, ,:
The results show that contrary to free formaldehyde the hydroxymethylaminopotassium acetate results in substantially stable r~tes of deposition over a large concentration area, which is of great importance for practical use.
PlIN 8289 10.12.1976 ~83303 FXA~IPLL ~V
Glass plates which had been activa-ted i.n thc same manner as in e~ample I were electroless copper plated in solutions which contain the following constituents per litre :
A) o.o6 Illole CuSoll.51I20 o . o66 mole tetrasodiumsalt of ethylenediamine~
tetra-acetic acid 0.10 mol NaOH
IO B) solution A~0.13 mole addition product of ; -alanine and formaldehyde (I~-aalt) C) solutinn A~0.13 mole addition product of ~-alanine and formaldehyde (K-salt) ~0,10 % per weight of polyoxyethylene compound "Triton" QS30 (Rohm and Haas), an anionic acid phosphate ester, D) solution A~0.10 mole addition product of serine nnd ~ormaldehyde (I~-salt) 0.10 wt. ~ '`Triton"QS30-~0 Some data as regards pH and temperature o~ the solutions and the results obtained are as fol.lows:
__. ~ I j - ~1 ¦SO1.B sol.C I sol. D
~ _ _ ._ __ ___., . ,, .,. ___ _,, pH I 12,9 12,8 12,8 ~ .__. _ ,__ .... _ _ __ __ , ,._ temperature I 600C 52C 52C
_ _, , ., . _ _ . _ . ,, , . .. _ _ . , ~ . _ , ,, ... .. .. . . _ ., , . , . _ _, _ deposit thicl~ness a~ter; 9/um 15/Um 13/Um 5 hours 3 ~ _ . ,, _ . ,,, . , , , ,~
ductility ~3 bendc 1 bend¦ 2 bends 10.12.1976 ~L083303 EXA~IPL~ V
Nucleated glass plates accorcling to example I were plated in solutions having varied concentrations in (free) forlllaldehyde and glycine and whicll also contain the following constituents per litre :(temperature 52~C)~
o . o6 mole CuSOIl.5H20 o.o66 mole tetrasodiumsalt of ethylenediaminetetra~
acetic acid 0.10 mole NaOH
0.10 ~ by weight of polyoxyethylene compound "Triton"
QS41~
X mole (free) formaldehyde Y mole glycine.
15- The pH of the solution was kept co~stant in all cases (approxi~ately 12.8). The results are shown in the table herebelow:
_ 0,10 - -0,10 0,10 ` -0,15 10,15 - 0,15 Y _ 0,05 0,10 0,05 0,10 0,15 deposit , ;` thiclcness ~um after 11 5 hours appr.20 ca. 15 ca.8 ca.16 ca.13 ca. 9 tllity l b i ' b l ~ 3 b l 2 b ~083303 EXAMPLE VI
Nucleated glass plates according to example I were electroless copper plated at a temperature of 52C
in a solution which contained per litre :
0.06 mole CuS04.5H20 0.066 mole tetrasodiumsalt of ethylenediaminetetra-acetic acid 0.10 mole NaOH
0.15 mole hydroxymethylaminoethanesodium sulphonate (addition product of formaldehyde and 2-aminoethanesodium sulphonate) After 6 hours approximately 13/um of copper had been deposited which had a ductility of at least 2 bends.
E~AMPLE VII
Nucleated glass plates according to example I were electroless copper plated at a temperature of 50 C
in a solution which contained the following consti-tuents for each litre :
0.02 mole CuS04.5H20 0.10 mole triethanolamine 0.40 mole NaOH
0.10 mole hydroxymethylaminopotassium acetate 0.20 % per weight of polyalkaleneglycol "Pluronic F 108" (trade mark) of Wyandotte Chemical Corporation.
"Pluronic F 108" is a condensate of propylene glycol and propylene oxide having a molecular weight of 16,000.
After 5 hours 15/um copper had been deposited on the glass plate. The ductility amounted to 2 bends. If "Pluronic F 108" was replaced by 0.025% by weight of PI-IN 8 2 c' 9 1~83303 1~. lo. 1976 a tllio-~tIler (C12:tI25-S-) of "PLuronic F I08" then the stability of` the solu-tion was increased w.Ili:Lst now 12/um of copper ~as deposited which had a ductility of bends.
, . .
.. ..
After each day the quantity of cupric ions used up was determined and added again. After the original pH was ad~usted copper was thereafter again deposited on new nucleated glass plates. In this manner the exhaustion as regards formaldehyde could be studied.
The quantities of copper per hours deposited with the two solutions had the following values :
¦ solution A l solutio~ B
1st day I 1.3 mg/cm2 hour ' 1.3 mg/cm2 hour _ .____. __ _.. ___ .. _ _._.. __ .. __ .~.. __ __ .. _ .. _. _ . . ___ _ i 2nd day j 1.1 mg/cm2 hour 1 0.5 mg/cm2 hour 3rd day ~ 1.1 mg/cm2 hour ~ 0.15mg/cm2 hour , - - ... ~ ~, - . .. . . . . . . ..
P]-~N 8289 lo. 12. 1976 EXA~IP1,~ III
Nucleated glass plates in acco:rdance w:ith ~xample I were electroless copper plated at a tempera-ture of 52~C in solutions which contained per litre the following constituents :
o.o6 mole cus04.5H20 o . o66 mole tetrasodiwnsal-t of ethylenediamine-tetra-acetic acid NaO~I to the required pH
a) varying concentrations in mole/l of hydroxymethyl-aminopotassium acetate b) varying concentrations in mole/l of free formal-dehyde.
The quantities of copper deposited per hour were as follo~s :
Conc.A¦ pH - - ~-~-~ -~ , pH 12,6 lonc ~ pH 12,4 . . ____ ______ _._~ . . _, .. .~.._ __ ._ .. _ _ _ __ _l 0,10 3,4 m,g/cm2.hour 4,0mg/cm2.hou~ 0,01,0,4mg/cm2.hour 0,20 3,6 mg/cm2.llour 4,6mg/cm2.hour!0,02 2,4mg/cm2.hour 0,30 3,6 mg/cm2.hour 4,7mg/cm2.hour10,03 j3,7mg/cm2.hour .5 3,5 mg/cm2.hour14,7mg/cm2.hour`0,04 ~,7mg/cm2.hour _ .. _ __ _ . _. ._._ ___ ,. _ _ _ _ _ _ _ ,, __ _ ,,_ , , _ _, ,, _, _ _ ,, ,:
The results show that contrary to free formaldehyde the hydroxymethylaminopotassium acetate results in substantially stable r~tes of deposition over a large concentration area, which is of great importance for practical use.
PlIN 8289 10.12.1976 ~83303 FXA~IPLL ~V
Glass plates which had been activa-ted i.n thc same manner as in e~ample I were electroless copper plated in solutions which contain the following constituents per litre :
A) o.o6 Illole CuSoll.51I20 o . o66 mole tetrasodiumsalt of ethylenediamine~
tetra-acetic acid 0.10 mol NaOH
IO B) solution A~0.13 mole addition product of ; -alanine and formaldehyde (I~-aalt) C) solutinn A~0.13 mole addition product of ~-alanine and formaldehyde (K-salt) ~0,10 % per weight of polyoxyethylene compound "Triton" QS30 (Rohm and Haas), an anionic acid phosphate ester, D) solution A~0.10 mole addition product of serine nnd ~ormaldehyde (I~-salt) 0.10 wt. ~ '`Triton"QS30-~0 Some data as regards pH and temperature o~ the solutions and the results obtained are as fol.lows:
__. ~ I j - ~1 ¦SO1.B sol.C I sol. D
~ _ _ ._ __ ___., . ,, .,. ___ _,, pH I 12,9 12,8 12,8 ~ .__. _ ,__ .... _ _ __ __ , ,._ temperature I 600C 52C 52C
_ _, , ., . _ _ . _ . ,, , . .. _ _ . , ~ . _ , ,, ... .. .. . . _ ., , . , . _ _, _ deposit thicl~ness a~ter; 9/um 15/Um 13/Um 5 hours 3 ~ _ . ,, _ . ,,, . , , , ,~
ductility ~3 bendc 1 bend¦ 2 bends 10.12.1976 ~L083303 EXA~IPL~ V
Nucleated glass plates accorcling to example I were plated in solutions having varied concentrations in (free) forlllaldehyde and glycine and whicll also contain the following constituents per litre :(temperature 52~C)~
o . o6 mole CuSOIl.5H20 o.o66 mole tetrasodiumsalt of ethylenediaminetetra~
acetic acid 0.10 mole NaOH
0.10 ~ by weight of polyoxyethylene compound "Triton"
QS41~
X mole (free) formaldehyde Y mole glycine.
15- The pH of the solution was kept co~stant in all cases (approxi~ately 12.8). The results are shown in the table herebelow:
_ 0,10 - -0,10 0,10 ` -0,15 10,15 - 0,15 Y _ 0,05 0,10 0,05 0,10 0,15 deposit , ;` thiclcness ~um after 11 5 hours appr.20 ca. 15 ca.8 ca.16 ca.13 ca. 9 tllity l b i ' b l ~ 3 b l 2 b ~083303 EXAMPLE VI
Nucleated glass plates according to example I were electroless copper plated at a temperature of 52C
in a solution which contained per litre :
0.06 mole CuS04.5H20 0.066 mole tetrasodiumsalt of ethylenediaminetetra-acetic acid 0.10 mole NaOH
0.15 mole hydroxymethylaminoethanesodium sulphonate (addition product of formaldehyde and 2-aminoethanesodium sulphonate) After 6 hours approximately 13/um of copper had been deposited which had a ductility of at least 2 bends.
E~AMPLE VII
Nucleated glass plates according to example I were electroless copper plated at a temperature of 50 C
in a solution which contained the following consti-tuents for each litre :
0.02 mole CuS04.5H20 0.10 mole triethanolamine 0.40 mole NaOH
0.10 mole hydroxymethylaminopotassium acetate 0.20 % per weight of polyalkaleneglycol "Pluronic F 108" (trade mark) of Wyandotte Chemical Corporation.
"Pluronic F 108" is a condensate of propylene glycol and propylene oxide having a molecular weight of 16,000.
After 5 hours 15/um copper had been deposited on the glass plate. The ductility amounted to 2 bends. If "Pluronic F 108" was replaced by 0.025% by weight of PI-IN 8 2 c' 9 1~83303 1~. lo. 1976 a tllio-~tIler (C12:tI25-S-) of "PLuronic F I08" then the stability of` the solu-tion was increased w.Ili:Lst now 12/um of copper ~as deposited which had a ductility of bends.
, . .
.. ..
Claims (4)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. An electroless aqueous copper plating bath comprising cupric ions, alkali for adjusting the pH, one or more compounds which form a complex with cupric ions and by way of reducing agent formaldehyde or a com-pound which yields formaldehyde, characterized in that the bath furthermore contains at least one of the salts of aminoalkanecarboxylic acids, aminoalkanesulphonic acids or amino-alkanephosphonic acids, which salts are free of bivalent sulphur and which have at least one free -NH2 group predominantly in the form of an addition product with formaldehyde via said -NH2 groups and in a quantity which is at the utmost molarly equal to the quantity of formaldehyde present.
2. A copper plating bath as claimed in Claim 1, characterized in that it also contains at least one polyoxyalkylene compound.
3. A copper plating bath as claimed in Claim 1, characterized in that it contains ethylenediaminetetra-sodium acetate as a complexing agent for cupric ions and glycine as an amino-acid.
4. A method of preparing an electroless copper plating bath as claimed in Claim 1, 2 or 3, character-ized in that the salt of the amino-alkanecarboxylic acid, -sulphonic acid and -phosphonic acid respectively and the formaldehyde are added separately in quantites wherein the salt is at the utmost molarly equal to the quantity of formaldehyde.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| NL7600689 | 1976-01-23 | ||
| NL7600689A NL178519C (en) | 1976-01-23 | 1976-01-23 | METHOD FOR PREPARING A BATH FOR CURRENT COPPERING. |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1083303A true CA1083303A (en) | 1980-08-12 |
Family
ID=19825510
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA270,026A Expired CA1083303A (en) | 1976-01-23 | 1977-01-19 | Electroless copper plating solutions |
Country Status (8)
| Country | Link |
|---|---|
| JP (1) | JPS5291739A (en) |
| BE (1) | BE850652A (en) |
| CA (1) | CA1083303A (en) |
| DE (1) | DE2701365C3 (en) |
| FR (1) | FR2339000A1 (en) |
| GB (1) | GB1555434A (en) |
| HK (1) | HK4981A (en) |
| NL (1) | NL178519C (en) |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| NL147484B (en) * | 1967-07-03 | 1975-10-15 | Shipley Co | PROCESS FOR PREPARING A WATERY BATH FOR CURRENT SALES, PROCEDURE FOR SELLER PROCEDURES AS WELL AS SELLER PRODUCTS OBTAINED UNDER THIS PROCEDURE. |
| US3754940A (en) * | 1972-09-06 | 1973-08-28 | Crown City Plating Co | Electroless plating solutions containing sulfamic acid and salts thereof |
| US3846138A (en) * | 1973-08-02 | 1974-11-05 | Webline Corp | Electroless copper plating |
-
1976
- 1976-01-23 NL NL7600689A patent/NL178519C/en not_active IP Right Cessation
-
1977
- 1977-01-14 DE DE19772701365 patent/DE2701365C3/en not_active Expired
- 1977-01-19 CA CA270,026A patent/CA1083303A/en not_active Expired
- 1977-01-20 GB GB230177A patent/GB1555434A/en not_active Expired
- 1977-01-21 FR FR7701697A patent/FR2339000A1/en active Granted
- 1977-01-21 BE BE174301A patent/BE850652A/en unknown
- 1977-01-22 JP JP545077A patent/JPS5291739A/en active Granted
-
1981
- 1981-02-19 HK HK4981A patent/HK4981A/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| DE2701365C3 (en) | 1979-05-03 |
| BE850652A (en) | 1977-07-22 |
| JPS5634631B2 (en) | 1981-08-11 |
| NL7600689A (en) | 1977-07-26 |
| GB1555434A (en) | 1979-11-07 |
| DE2701365B2 (en) | 1978-08-31 |
| NL178519C (en) | 1986-04-01 |
| NL178519B (en) | 1985-11-01 |
| FR2339000A1 (en) | 1977-08-19 |
| DE2701365A1 (en) | 1977-07-28 |
| HK4981A (en) | 1981-02-27 |
| JPS5291739A (en) | 1977-08-02 |
| FR2339000B1 (en) | 1981-03-06 |
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