Plating bath and method for electroplating tin and/or lead

Claim 2

An aqueous tin, lead, or tin-lead alloy electroplating bath free of fluoride and borofluoride ions comprising (A) at least one bath-soluble metal salt selected from the group consisting of a stannous salt, a lead salt, or a mixture of stannous and lead salts, (B) at least one alkane sulfonic acid or alkanol sulfonic acid, (C) at least one surfactant, (D) an effective amount of at least one primary brightening agent selected from the group consisting of halo-, dialkoxy- and trialkoxy-substituted benzaldehydes containing from 1 to about four carbon atoms in the alkoxy groups, (E) an effective amount of a secondary brightening agent which is at least one lower aliphatic aldehyde, and (F) an effective amount of at least one auxiliary brightening agent selected from the group of compounds having the following structural formula: ##STR12## wherein X is a hydrogen, halogen, alkyl, lower alkoxy, amino, or carboxyl substituent or a mixture thereof and a is an integer from 0 to 3 inclusive.

Claim 3

The plating bath of claim 1 containing as the element (F) an effective amount of an auxiliary brightening agent selected from the group consisting of diethyl, dimethyl, triethyl and trimethyl anilines or a mixture thereof.

Claim 4

The plating bath of claim 1 wherein the auxiliary brightening agent is xylidene.

Claim 5

The plating bath of claim 1 wherein the concentration of said auxiliary brightening agent is in the range of from about 0.02 to about 5 grams per liter.

Claim 6

The method of electrodepositing a bright tin, lead or tin-lead alloy on a substrate which comprises electroplating said substrate in the aqueous acidic plating bath of claim 1.

Claim 7

An aqueous tin, lead, or tin-lead alloy electroplating bath free of fluoride and borofluoride ions comprising (A) at least one bath-soluble metal salt selected from the group consisting of a stannous salt, a lead salt, or a mixture of stannous and lead salts, (B) at least one alkane sulfonic acid or alkanol sulfonic acid, (C) at least one surfactant, (D) an effective amount of at least one primary brightening agent selected from the group consisting of dialkoxy- and trialkoxy-substituted benzaldehydes containing from one to about four carbon atoms in the alkoxy groups, and (E) an effective amount of a secondary brightening agent which is at least one lower aliphatic aldehyde.

Claim 8

An aqueous tin, lead, or tin-lead alloy electroplating bath free of fluoride and borofluoride ions comprising (A) at least one bath-soluble metal salt selected from the group consisting of a stannous salt, a lead salt, or a mixture of stannous and lead salts, (B) at least one alkane sulfonic acid or alkanol sulfonic acid, (C) at least one surfactant, (D) an effective amount of at least one primary brightening agent selected from the group consisting of dialkoxy- and trialkoxy-substituted benzaldehydes containing from one to about four carbon atoms in the alkoxy groups, and (E) an effective amount of a secondary brightening agent which is at least one lower aliphatic aldehyde.

Claim 9

The plating bath of claim 6 wherein the bath-soluble metal salts (A) comprise the salts of at least one alkane sulfonic acid or alkanol sulfonic acid and mixtures thereof.

Claim 10

The platng bath of claim 6 wherein the alkane sulfonic acid and alkanol sulfonic acid are characterized by the following formulae ##STR13## respectively where R is an aliphatic group containing from 1 to about 12 carbon atoms, n is from 0 to about 10, m is from 1 to about 11, and the sum of m+n is up to about 12.

Claim 11

The plating bath of claim 6 wherein the primary brightening agent is a dialkoxybenzaldehyde.

Claim 12

The plating bath of claim 6 wherein the primary brightening agent is a dimethoxybenzaldehyde.

Claim 13

The plating bath of claim 6 wherein the secondary brightening agent is acetaldehyde.

Claim 14

The plating bath of claim 6 also containing an effective amount of an antioxidant.

Claim 15

The plating bath of claim 12 wherein the antioxidant is catechol.

Claim 16

The method of electrodepositing a bright tin, lead or tin-lead alloy on a substrate which comprises electroplating said substrate in the aqueous acidic plating bath of claim 6.

Claim 17

The method of claim 14 wherein the primary brightening agent is a dialkoxybenzaldehyde.

Claim 18

An aqueous plating bath for electrodeposition of a tin, lead or tin-lead alloy, which plating bath is free of fluoride and fluoborates and comprises (A) from about 0.5 to about 350 grams per liter of at least one stannous ion, lead ion or mixture of stannous and lead ions, (B) from about 10 to about 500 grams per liter of at least one alkane sulfonic acid having the general formula RSO.sub.3 H (I) or an alkanol sulfonic acid of the general formula ##STR14## wherein R is an aliphatic group containing from 1 to about 6 carbon atoms, n is from 0 to about 10, m is from 1 to about 11 and the sum of m+n is up to about 12, (C) from about 0.01 to about 50 grams per liter of at least one surfactant, (D) an effective amount of at least one primary brightening agent selected from the group consisting of those compounds having the general formula ##STR15## wherein R 1 and R 2 are each independently alkyl groups containing from one to about four carbon atoms, and R 3 is hydrogen or an alkoxy group containing from one to about four carbon atoms, and (E) an effective amount of a secondary brightening agent which is at least one lower aliphatic aldehyde.

Claim 19

An aqueous plating bath for electrodeposition of a tin, lead or tin-lead alloy, which plating bath is free of fluoride and fluoborates and comprises (A) from about 0.5 to about 350 grams per liter of at least one stannous ion, lead ion or mixture of stannous and lead ions, (B) from about 10 to about 500 grams per liter of at least one alkane sulfonic acid having the general formula RSO.sub.3 H (I) or an alkanol sulfonic acid of the general formula ##STR14## wherein R is an aliphatic group containing from 1 to about 6 carbon atoms, n is from 0 to about 10, m is from 1 to about 11 and the sum of m+n is up to about 12, (C) from about 0.01 to about 50 grams per liter of at least one surfactant, (D) an effective amount of at least one primary brightening agent selected from the group consisting of those compounds having the general formula ##STR15## wherein R 1 and R 2 are each independently alkyl groups containing from one to about four carbon atoms, and R 3 is hydrogen or an alkoxy group containing from one to about four carbon atoms, and (E) an effective amount of a secondary brightening agent which is at least one lower aliphatic aldehyde.

Claim 20

The platng bath of claim 16 wherein the primary brightening agent is present in an amount of from about 0.02 to about 5 grams per liter.

Claim 21

The plating bath of claim 16 wherein the secondary brightening agent is present in an amount of from about 0.1 to about 20 grams per liter.

Claim 22

The plating bath of claim 16 wherein the primary brightening agent is a dialkoxybenzaldehyde.

Claim 23

The plating bath of claim 18 wherein the secondary brightening agent is acetaldehyde.

Claim 24

The plating bath of claim 16 also containing: (F) an effective amount of an auxiliary brightening agent selected from the group consisting of diethyl, dimethyl, triethyl and trimethyl anilines, or a mixture thereof.

Claim 25

The plating bath of claim 16 also containing; (F) an effective amount of an auxiliary brightening agent, xylidene.

Claim 26

The method of electrodeposition a bright tin, lead or tin-lead alloy on a substrate which comprises electroplating said substrate in the aqueous acidic plating bath of claim 16.

Claim 27

An aqueous tin, lead, or tin-lead alloy electroplating bath free of fluoride and borofluoride ions comprising (A) at least one bath-soluble metal salt selected from the group consisting of a stannous salt, a lead salt, or a mixture of stannous and lead salts, (B) at least one alkane sulfonic acid or alkanol sulfonic acid, (C) at least one surfactant, (D) an effective amount of at least one primary brightening agent selected from the group consisting of dialkoxy- and trialkoxy-substituted benzaldehydes containing from one to about four carbon atoms in the alkoxy groups, (E) an effective amount of a secondary brightening agent which is at least one lower aliphatic aldehyde, (F) an effective amount of an auxiliary brigthening agent selected from the group consisting of compounds having the following structural formula: ##STR16## wherein X is independently hydrogen, halogen, alkyl, lower alkoxy or carboxyl substituents or a mixture thereof, and a is an integer from 0 to 3 inclusive.

Claim 28

An aqueous tin, lead, or tin-lead alloy electroplating bath free of fluoride and borofluoride ions comprising (A) at least one bath-soluble metal salt selected from the group consisting of a stannous salt, a lead salt, or a mixture of stannous and lead salts, (B) at least one alkane sulfonic acid or alkanol sulfonic acid, (C) at least one surfactant, (D) an effective amount of at least one primary brightening agent selected from the group consisting of dialkoxy- and trialkoxy-substituted benzaldehydes containing from one to about four carbon atoms in the alkoxy groups, (E) an effective amount of a secondary brightening agent which is at least one lower aliphatic aldehyde, (F) an effective amount of an auxiliary brigthening agent selected from the group consisting of compounds having the following structural formula: ##STR16## wherein X is independently hydrogen, halogen, alkyl, lower alkoxy or carboxyl substituents or a mixture thereof, and a is an integer from 0 to 3 inclusive.

Claim 29

The plating bath of claim 24 wherein said auxiliary brightening agent is selected from the group consisting of dimethyl and trimethyl anilines, or a mixture thereof.

Claim 30

The plating bath of claim 24 wherein said auxiliary brightening agent is xylidene.

Claim 31

The plating bath of claim 24 wherein the total concentration of said auxiliary brightening agent is in the range of from about 0.02 to about 5 grams per liter.

Claim 32

The method of electrodepositing a bright tin, lead or tin-lead alloy on a substrate which comprises electroplating said substrate in the aqueous acidic plating bath of claim 24.

Claim 33

The method of claim 28 wherein said auxiliary brightening agent is xylidene.

Claim 34

An aqueous tin, lead, or tin-lead alloy electroplating bath free of fluoride and borofluoride ions comprising (A) at least one bath-soluble metal salt selected from the group consisting of a stannous salt, and lead salt, or a mixture of stannous and lead salts, (B) at least one alkane sulfonic acid or alkanol sulfonic acid, (C) at least one surfactant, (D) an effective amount of at least one primary brightening agent selected from the group consisting of halo-substituted benzaldehydes, (E) an effective amount of a secondary brightening agent which is at least one lower aliphatic aldehyde, and (F) an effective amount of an auxiliary brightening agent selected from the group consisting of compounds having the following structural formula: ##STR17## wherein X is a hydrogen, halogen, alkyl, lower alkoxy or carboxyl substituent or a mixture thereof, and a is an integer from 0 to 3 inclusive.

Claim 35

An aqueous tin, lead, or tin-lead alloy electroplating bath free of fluoride and borofluoride ions comprising (A) at least one bath-soluble metal salt selected from the group consisting of a stannous salt, and lead salt, or a mixture of stannous and lead salts, (B) at least one alkane sulfonic acid or alkanol sulfonic acid, (C) at least one surfactant, (D) an effective amount of at least one primary brightening agent selected from the group consisting of halo-substituted benzaldehydes, (E) an effective amount of a secondary brightening agent which is at least one lower aliphatic aldehyde, and (F) an effective amount of an auxiliary brightening agent selected from the group consisting of compounds having the following structural formula: ##STR17## wherein X is a hydrogen, halogen, alkyl, lower alkoxy or carboxyl substituent or a mixture thereof, and a is an integer from 0 to 3 inclusive.

Claim 36

The plating bath of claim 30 wherein said auxiliary brightening agent is selected from the group consisting of dimethyl and trimethyl anilines, or a mixture thereof.

Claim 37

The plating bath of claim 30 wherein said auxiliary brightening agent is xylidene.

Claim 38

The plating bath of claim 30 wherein the total concentration of said auxiliary brightening agent is in the range of from about 0.02 to about 5 grams per liter.

Claim 39

An aqueous plating bath for electrodeposition of a tin, lead or tin-lead alloy, which plating bath is free of fluoride and fluoborates and comprises (A) from about 0.5 to about 350 grams per liter of at least one stannous ion, lead ion or mixture of stannous and lead ions, (B) from about 10 to about 500 grams per liter of at least one alkane sulfonic acid having the general formula RSO.sub.3 H (I) or an alkanol sulfonic acid of the general formula ##STR18## wherein R is an aliphatic group containing from 1 to about 6 carbon atoms, n is from 0 to about 10, m is from 1 to about 11 and the sum of m+N is up to about 12, (C) from about 0.01 to about 50 grams per liter of at least one surfactant, (D) an effective amount of at least one primary brightening agent selected from the group consisting of those compounds having the general formula ##STR19## wherein R 1 and R 2 are each independently alkyl groups containing from one to about four carbon atoms, and R 3 is hydrogen or an alkoxy group containing from one to about four carbon atoms, and mono- and dichlorobenzaldehydes, (E) an effective amount of a secondary brightening agent which is at least one lower aliphatic aldehyde, and (F) an effective amount of an auxiliary brightening agent selected from the group consisting of diethyl, dimethyl, triethyl and trimethyl anilines, or a mixture thereof.

Claim 40

An aqueous plating bath for electrodeposition of a tin, lead or tin-lead alloy, which plating bath is free of fluoride and fluoborates and comprises (A) from about 0.5 to about 350 grams per liter of at least one stannous ion, lead ion or mixture of stannous and lead ions, (B) from about 10 to about 500 grams per liter of at least one alkane sulfonic acid having the general formula RSO.sub.3 H (I) or an alkanol sulfonic acid of the general formula ##STR18## wherein R is an aliphatic group containing from 1 to about 6 carbon atoms, n is from 0 to about 10, m is from 1 to about 11 and the sum of m+N is up to about 12, (C) from about 0.01 to about 50 grams per liter of at least one surfactant, (D) an effective amount of at least one primary brightening agent selected from the group consisting of those compounds having the general formula ##STR19## wherein R 1 and R 2 are each independently alkyl groups containing from one to about four carbon atoms, and R 3 is hydrogen or an alkoxy group containing from one to about four carbon atoms, and mono- and dichlorobenzaldehydes, (E) an effective amount of a secondary brightening agent which is at least one lower aliphatic aldehyde, and (F) an effective amount of an auxiliary brightening agent selected from the group consisting of diethyl, dimethyl, triethyl and trimethyl anilines, or a mixture thereof.

Claim 41

The plating bath of claim 34 wherein (F) is xylidene.