Method for improving plating on non-conductive substrates
View Patent ↗A method of treating a laser-activated thermoplastic substrate having a metal compound dispersed therein is described. The substrate is contacted with an aqueous composition comprising: (i) a thiol functional organic compound; (ii) an ethoxylated alcohol surfactant; and (iii) xanthan gum. By use of the treatment composition, when the substrate is subsequently laser-activated and plated by electroless plating, extraneous plating of the substrate is substantially eliminated.
1. A method of treating a laser-activatable non-conductive substrate that comprises a metal compound, the method comprising the steps of:
a) treating the laser-activatable non-conductive substrate that comprises the metal compound with an aqueous composition comprising:
i) a thiol functional organic compound; and
ii) optionally, a surfactant;
b) selectively laser activating portions of a surface of the laser-activatable non-conductive substrate;
c) contacting the substrate with an electroless plating bath such that areas of the laser-activatable non-conductive substrate which were contacted by the laser plate, but areas that were not contacted by the laser do not plate.
2. The method according to claim 1 , wherein the thiol functional organic is selected from the group consisting of dodecanethiol, lauryl mercaptan, cetyl mercaptan, and stearyl mercaptan, alkyl thioglycollate, stearyl thioglycollate, cetyl thioglycollate, methyl mercaptan, n-butyl mercaptan, cyclohexyl mercaptan, n-dodecyl mercaptan, n-propyl mercaptan, n-octyl mercaptan, t-nonyl mercaptan and combinations of one or more of the foregoing.
3. The method according to claim 2 , wherein the thiol functional organic comprises stearyl mercaptan.
4. The method according to claim 1 , wherein the concentration of the thiol functional organic in the aqueous composition is about 1 to about 20 g/l.
5. The method according to claim 1 , wherein the surfactant comprises an ethoxylated alcohol surfactant.
6. The method according to claim 5 , wherein the concentration of the ethoxylated alcohol surfactant in the aqueous composition is between about 0.1 to about 10 g/l.
7. The method according to claim 1 , wherein the aqueous compositions also comprises xanthum gum.
8. The method according to claim 7 , wherein the aqueous composition comprises a surfactant.
9. The method according to claim 1 , wherein the aqueous composition comprises a surfactant.
10. The method according to claim 1 , wherein the electroless plating bath comprises an electroless copper plating bath.
11. The method according to claim 1 , wherein the laser-activatable non-conductive substrate comprises thermoplastic resins or thermosetting resins.
12. The method according to claim 11 , wherein the laser-activatable non-conductive substrate comprises a thermoplastic resin selected from the group consisting of polycarbonate/acrylonitrile butadiene styrene blend resins, cross-linked polybutyleneterephthalate, nylon, and liquid crystal polymers.
13. The method according to claim 12 , wherein the laser-activatable non-conductive substrate comprises a polycarbonate/acrylonitrile-butadiene-styrene blend resin.
14. The method according to claim 1 , wherein the laser-activatable non-conductive substrate is impregnated with a copper compound.
15. A method of treating a laser-activatable non-conductive substrate that comprises a metal compound, the method comprising the steps of:
a) treating the laser-activatable non-conductive substrate that comprises the metal compound with an aqueous composition comprising:
i) a thiol functional organic compound selected from the group consisting of dodecanethiol, lauryl mercaptan, cetyl mercaptan, stearyl mercaptan, alkyl thioglycollate, stearyl thioglycollate, cetyl thioglycollate, methyl mercaptan, n-butyl mercaptan, cyclohexyl mercaptan, n-dodecyl mercaptan, n-propyl mercaptan, n-octyl mercaptan, t-nonyl mercaptan and combinations of one or more of the foregoing; and
ii) optionally, a surfactant;
b) selectively laser activating portions of a surface of the laser-activatable non-conductive substrate;
c) contacting the substrate with an electroless plating bath such that areas of the laser-activatable non-conductive substrate which were contacted by the laser plate, but areas that were not contacted by the laser do not plate.