US3616306A
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Tin plating bath and method
Assignee: Conversion Chemical Corp
•
Filing: 1969-11-19
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Granted: 1971-10-26
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Expires: 1989-11-19
Abstract
Abstract An aqueous bath for electroplating tin upon various conductive substrates contains stannous ion, sulfate radical, an imidazoline derivative, a carbinamine compound, and a cyclic aldehyde or ketone brightener. The bath is highly acid and is operable to produce dense, smooth, bright, adherent deposits, particularly at relatively high current densities. These deposits exhibit excellent solderability as plated and after prolonged aging. In addition, the bath avoids step plating when holes are present in the workpiece, and it minimizes the tendency for pitting to occur in the deposit.
Inventors
- 👤 Joseph F Conoby
- 👤 Kenneth P Bellinger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 12:05
CPC Classifications
C; C25; C25D; C25D3/00; C25D3/02; C25D3/30; C25D3/32
Claims Analysis
Total Claims: 50
Claim 1
Independent Claim
27 words
G is a radical selected from the group consisting of -OH, acid salt radicals, anionic surface active sulfate salt radicals, and anionic surface active sulfonate salt radicals;
Claim 2
Dependent Claim
27 words
G is a radical selected from the group consisting of -OH, acid salt radicals, anionic surface active sulfate salt radicals, and anionic surface active sulfonate salt radicals;
Claim 3
Dependent Claim
12 words
maintaining said bath at a temperature of about 45* to 135* Fahrenheit;
Claim 4
Dependent Claim
77 words
The bath of claim 1 comprising about 55.0 to 75.0 grams per liter of stannous ion; about 125.0 to 200.0 grams per liter of sulfate radical; about 1.0 to 15.0 grams per liter of imidazoline derivative; about 0.1 to 1.0 gram per liter of alkyl phenol condensate; about 0.5 to 10.0 grams per liter of carbinamine compound; about 0.05 to 0.5 gram per liter of brightener; and about 1.5 to 3.0 grams per liter of hydrogen ion.
Claim 5
Dependent Claim
34 words
The bath of claim 2 wherein said imidazoline derivative and said carbinamine compound are present in respective concentrations of about 5.0 to 10.0 grams per liter and about 2.0 to 5.0 grams per liter.
Claim 6
Dependent Claim
15 words
immersing a workpiece having a metallic surface and a tin anode in said bath; and
Claim 7
Dependent Claim
14 words
Z is a radical selected from the group consisting of -COOM, -CH2COOM, and -CHOH-CH2SO3M;
Claim 8
Dependent Claim
14 words
Z is a radical selected from the group consisting of -COOM, -CH2COOM, and -CHOH-CH2SO3M;
Claim 9
Dependent Claim
16 words
M is a substituent selected from the group consisting of hydrogen, alkali metals and organic bases;
Claim 10
Dependent Claim
16 words
M is a substituent selected from the group consisting of hydrogen, alkali metals and organic bases;
Claim 11
Dependent Claim
33 words
applying a voltage across said anode and workpiece to deposit tin on said metallic surface, said voltage providing a current density of about 10.0 to 200.0 amperes per square foot at the workpiece.
Claim 12
Dependent Claim
13 words
The bath of claim 1 wherein the imidazoline derivative corresponds to the formula:
Claim 13
Dependent Claim
11 words
Y is selected from the group consisting of -OR'' and -N(R'')3A;
Claim 14
Dependent Claim
11 words
Y is selected from the group consisting of -OR'' and -N(R'')3A;
Claim 15
Dependent Claim
57 words
The bath of claim 4 wherein said imidazoline derivative has a structure wherein -G is an anionic surface active sulfate salt radical having the formula -OSO2-OR in which sulfate salt radical R is an alkyl group containing 10 to 18 carbon atoms, and wherein Z is a -COOM radical in which M is an alkali metal cation.
Claim 16
Dependent Claim
44 words
The bath of claim 1 wherein said imidazoline derivative is selected from the group consisting of 2-alkyl-1-(ethyl-betaoxypropanoic acid)-imidazolines wherein the alkyl group is selected from the class consisting of capryl, undecyl and mixtures of C7-C17 chains, and the disodium salt of lauroyl-cyclo-imidinium-1-ethoxy-ethanoic acid-2-ethanoic acid.
Claim 17
Dependent Claim
16 words
each R'' substituent is independently selected from the group consisting of hydrogen, alkali metals, and -(CH2)n-COOM;
Claim 18
Dependent Claim
16 words
each R'' substituent is independently selected from the group consisting of hydrogen, alkali metals, and -(CH2)n-COOM;
Claim 19
Dependent Claim
6 words
A is an anionic monovalent radical;
Claim 20
Dependent Claim
6 words
A is an anionic monovalent radical;
Claim 21
Dependent Claim
79 words
The bath of claim 1 wherein said imidazoline derivative is a mixture of (A) an imidazoline derivative wherein the groups -G and -CH2Z are both omitted and Y is -N((CH2)n-COOH)3C1, n being equal to 1 to 4; and (B) an imidazoline derivative wherein -G is -OH, wherein -Y is equal to -O(CH2)nCOOM and wherein Z is equal to -(CH2)mCOOM, n being equal to 1 to 4 and m equal to 0 to 1, and M being an alkali metal.
Claim 22
Dependent Claim
25 words
The bath of claim 7 wherein imidazoline derivative (A) is present in a weight ratio relative to imidazoline derivative (B) of about 1.0 to 8.0:1.0.
Claim 23
Dependent Claim
9 words
n is an integer from 1 to 4; and
Claim 24
Dependent Claim
9 words
n is an integer from 1 to 4; and
Claim 25
Dependent Claim
10 words
both the groups G and CH2Z are present or absent.
Claim 26
Dependent Claim
10 words
both the groups G and CH2Z are present or absent.
Claim 27
Dependent Claim
28 words
The bath of claim 1 wherein the alkyl group of said alkyl phenol in said condensate is selected from the class consisting of octyl, nonyl and mixtures thereof.
Claim 28
Dependent Claim
23 words
The bath of claim 1 wherein said carbinamine compound has the general formula and wherein e is an integer from 12 to 15.
Claim 29
Dependent Claim
24 words
The bath of claim 10 wherein in said carbinamine compound X is -H and a and b each represent numbers from 15 to 20.
Claim 30
Dependent Claim
27 words
The bath of claim 1 wherein said brightener has a heterocyclic ring and wherein an aldehyde group is attached directly to a carbon atom in the ring.
Claim 31
Dependent Claim
12 words
The bath of claim 12 wherein said heterocyclic ring contains five members.
Claim 32
Dependent Claim
12 words
The bath of claim 13 wherein said aldehyde brightener is thiophene aldehyde.
Claim 33
Dependent Claim
33 words
The bath of claim 1 wherein at least the predominant portion of said stannous ion is provided by stannous sulfate and wherein a portion of said sulfate radical is furnished by sulfuric acid.
Claim 34
Dependent Claim
9 words
In a method for electroplating tin, the steps comprising:
Claim 35
Dependent Claim
39 words
The method of claim 16 wherein said bath is maintained at a temperature of about 60* to 90* Fahrenheit and wherein said voltage provides a current density of about 50 to 100 amperes per square foot at the workpiece.
Claim 36
Dependent Claim
41 words
The method of claim 17 wherein the ratio of the area of said anode to that of the workpiece is about 1.5 to 3.0:1.0, and wherein the current density at said anode is less than about 40 amperes per square foot.
Claim 37
Dependent Claim
77 words
The method of claim 16 comprising about 55.0 to 75.0 grams per liter of stannous ion; about 125.0 to 200.0 grams per liter of sulfate radical; about 1.0 to 15.0 grams per liter of imidazoline derivative; about 0.1 to 1.0 gram per liter of alkyl phenol condensate; about 0.5 to 10.0 grams per liter of carbinamine compound; about 0.05 to 0.5 gram per liter of brightener; and about 1.5 to 3.0 grams per liter of hydrogen ion.
Claim 38
Dependent Claim
34 words
The method of claim 19 wherein said imidazoline derivative and said carbinamine compound are present in respective concentrations of about 5.0 to 10.0 grams per liter and about 2.0 to 5.0 grams per liter.
Claim 39
Dependent Claim
13 words
The method of claim 16 wherein the imidazoline derivative corresponds to the formula:
Claim 40
Dependent Claim
56 words
The method of claim 21 wherein said imidazoline derivative has a structure wherein -G is an anionic surface-active sulfate salt radical having the formula -OSO2-OR in which sulfate salt radical R is an alkyl group containing 10 to 18 carbon atoms, and wherein Z is a -COOM radical in which M is an alkali metal cation.
Claim 41
Dependent Claim
44 words
The method of claim 16 wherein said imidazoline derivative is selected from the group consisting of 2-alkyl-1-(ethyl-betaoxypropanoic acid)-imidazolines wherein the alkyl group is selected from the class consisting of capryl, undecyl and mixtures of CC1, chains, and the disodium salt of lauroyl-cyclo-imidinium-1-ethoxyethanoic acid-2-ethanoic acid.
Claim 42
Dependent Claim
79 words
The method of claim 16 wherein said imidazoline derivative is a mixture of (A) an imidazoline derivative wherein the groups -G and -CH2Z are both omitted and Y is -N((CH2)n-COOH)3C1, n being equal to 1 to 4; and (B) an imidazoline derivative wherein -G is -OH, wherein -Y is equal to -O(CH2)nCOOM and wherein Z is equal to -(CH2)mCOOM, n being equal to 1 to 4 and m equal to 0 to 1, and M being an alkali metal.
Claim 43
Dependent Claim
25 words
The method of claim 24 wherein imidazoline derivative (A) is present in a weight ratio relative to imidazoline derivative (B) of about 1.0 to 8.0:1.0.
Claim 44
Dependent Claim
28 words
The method of claim 16 wherein the alkyl group of said alkyl phenol in said condensate is selected from the class consisting of octyl, nonyl and mixtures thereof.
Claim 45
Dependent Claim
23 words
The method of claim 16 wherein said carbinamine compound has the general formula and wherein e is an integer from 12 to 15.
Claim 46
Dependent Claim
24 words
The method of claim 27 wherein in said carbinamine compound X is -H and a and b each represent numbers from 15 to 20.
Claim 47
Dependent Claim
27 words
The method of claim 16 wherein said brightener has a heterocyclic ring and wherein an aldehyde group is attached directly to a carbon atom in the ring.
Claim 48
Dependent Claim
12 words
The method of claim 29 wherein said heterocyclic ring contains five members.
Claim 49
Dependent Claim
12 words
The method of claim 30 wherein said aldehyde brightener is thiophene aldehyde.
Claim 50
Dependent Claim
33 words
The method of claim 16 wherein at least the predominant portion of said stannous ioN is provided by stannous sulfate and wherein a portion of said sulfate radical is furnished by sulfuric acid.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-10-25 | 1975-04-26 | 1975-10-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-10-25 | 1979-04-26 | 1979-10-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-10-25 | 1983-04-26 | 1983-10-26 | $7700.00 | Window Closed / Lapsed |