1. A solution for use in connection with the deposition of a gold-tin alloy on an electrically conductive substrate, the solution comprising water, complexed gold ions, tin ions, a complexing compound to render the tin ions soluble in the solution, and an alloy stabilization agent present in an amount sufficient to stabilize the alloy composition that is deposited, wherein the solution has a pH of between about 2 to 10 and the gold ions and tin ions are present in relative amounts sufficient to provide a deposit having a gold content of less than about 90% by weight and a tin content greater than about 10% by weight.
2. The solution of claim 1 wherein the gold ions and tin ions are present in relative amounts sufficient to provide a deposit having a gold content of between 75 and 85% by weight and a tin content of between 15 and 25% by weight.
3. The solution of claim 1 wherein the complexed gold ions comprise a mono-valent gold cyanide complex, a tri-valent gold cyanide complex or a gold sulfite complex.
4. The solution of claim 1 wherein the tin ions are present in a divalent oxidation state, a tetravalent oxidation state, or a combination thereof.
5. The solution of claim 1 wherein the complexing agent for the tin ions is a solution soluble oxalate, citrate, tartrate, glycerate, ascorbate, gluconate, heptagluconate, malonate, iminodiacetate, nitrilotriacetate, ethylene di-amino-tetra acetate or pyrophosphate.
6. The solution of claim 1 wherein the antioxidant is catechol, hydroquinone, phenolsulfonic acid, potassium ferro-hexacyanide, hydrazine, hydroxylamine, pyrogallol, tiron, cresolsulphonic acid, pyrocatechol, resorcinol, phloroglucinol, 2-aminodiphenylmethane or p-hydroxyanisole.
7. The solution of claim 1 wherein the complexed gold ions are present in amount between about 0.1 and 100 gl.
8. The solutions of claim 1 wherein the tin ions are present in the amount between about 0.1 and 50 gl.
9. The solution of claim 1 wherein the complexing agent for the tin ions is present in the solution from about 5 gl to about saturation.
10. The solution of claim 1 wherein the alloy stabilizing agent is an anionic surfactant based on phosphate esters of general structural formula:
wherein R is alkyl or alkyl aryl group;
n is 7 to 10 moles of ethylene andor propylene oxide;
M is hydrogen, sodium, potassium or other counter ion; and
R\u2032 is ethyl andor propyl group.
11. The solution of claim 10 wherein the anionic surfactant is poly(oxy-1,2-ethanediyl).alpha.-tridecyl-.O.mega.-hydroxy-.phosphate in a concentration of 0.1 to 10 grams per liter.
12. The solution of claim 1 which further comprises at least one of an anti-oxidation compound or a brightening agent.
13. The solution of claim 12 wherein the antioxidant is present in an amount of about 0.005 to about 20 gl.
14. The solution of claim 12 wherein the brightening agent is an amphoteric wetting agent of general structural formula:
wherein R is fatty acid alkyl group.
15. The solution of claim 14 wherein the brightening agent is sodium coco-di-propionate and is present in a concentration of about of 0.05 to 5 gram per liter.
16. The solution of claim 14 wherein the alloy stabilizing agent is an anionic surfactant based on phosphate esters of general structural formula:
wherein R is alkyl or alkyl aryl group;
n is 7 to 10 moles of ethylene andor propylene oxide;
M is hydrogen, sodium, potassium or other counter ion; and
R\u2032 is ethyl andor propyl group
and the alloy stabilizing agent contributes to brightening of the deposit.
17. The solution of claim 16 wherein the alloy stabilizing agent is present in a concentration of about 0.1 to 10 grams per liter and the brightening agent is present in a concentration of about 0.05 to 5 grams per liter.
18. The solution of claim 1, wherein the solution has a pH of between about 3 and about 5.5.
19. A method for electroplating of a gold-tin deposit on a substrate which comprises contacting the substrate with the solution of claim 1 and passing a current through the solution to provide a gold-tin alloy deposit thereon.
20. The method of claim 19, wherein the gold ions and tin ions are present in relative amounts sufficient to provide a deposit having a gold content of between 75 and 85% by weight and a tin content of between 15 and 25% by weight.
21. A method for electroplating a gold-tin deposit on composite articles that include electroplatable and non-electroplatable portions which comprises contacting such articles with the solution of claim 1 and passing a current through the solution to provide a gold-tin alloy deposit on the electroplatable portions of the articles without deleteriously affecting the non-electroplatable portions of the article.
22. The method of claim 21, wherein the gold ions and tin ions are present in relative amounts sufficient to provide a deposit having a gold content of between 75 and 85% by weight and a tin content of between 15 and 25% by weight.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A creeper comprising a frame having longitudinally extending laterally spaced side rails interconnected by longitudinally spaced laterally extending end members, said end members being the only connection between said side rails, at least one support rail longitudinally extending between said end members, said support rail not being connected to said side rails, a first pad carried by said support rails, and a second pad carried by said support rails, there being a space between said pads in both the longitudinal direction and the vertical direction.
2. The creeper of claim 1 wherein there are two laterally spaced longitudinally extending support rails.
3. The creeper of claim 1 wherein each support rail includes a first generally horizontal portion supporting said first pad, a second generally horizontal portion supporting said second pad, and a third portion between said first and second portions.
4. The creeper of claim 1 further comprising at least one tray carried by said frame within the profile of said frame.
5. A creeper, comprising a frame having longitudinally extending laterally spaced side rails interconnected by longitudinally spaced laterally extending end members, said frame thereby having an outer profile, two trays carried by said frame within said outer profile, and a tray frame extending inwardly from each said side rail, each said tray having a bottom surface, sidewalls extending upwardly from the periphery of said bottom surface, and a flange extending outwardly from the upper periphery of said sidewalls, said flange being adapted to rest on said tray frame and on a portion of said side rail.