Patterning of electroless metals by selective deactivation of catalysts
Methods and devices for patterning electroless metals on a substrate are presented. An active catalyst layer on the substrate can be covered with a patterned mask and treated with a deactivating chemical reagent, which deactivates the catalyst layer not covered by the mask. Once the patterned mask is removed, the electroless metal layer can be placed to have a patterned electroless metals. Alternatively, a substrate can be coated with a blocking reagent in a pattern first to inhibit formation of the catalyst layer before a catalyst layer can be placed over the blocking agent layer and then electroless metal layer is placed on the catalyst layer. The pattern of the blocking reagent acts as a negative pattern of the final conductive line pattern.
1. A method of patterning of electroless metals, comprising steps of:
placing a blocking reagent in a pattern on a substrate to form a substrate with a blocking agent layer;
placing a layer of a catalyst on the substrate having the blocking agent layer;
placing an electroless metal layer on the catalyst layer;
wherein the blocking reagent inhibits formation of the catalyst layer on the blocking agent layer; and
wherein the layer of the catalyst has an average thickness of less than 10 atoms of the catalyst.
2. The method of claim 1 , wherein the electroless metal comprises at least one of the following: copper and nickel.
3. The method of claim 1 , wherein the substrate comprises at least one of the following: a polyimide, a cloth, a plastic, a metal, a ceramic, and a resin.
4. The method of claim 1 , wherein the blocking reagent comprises at least one of the following: copper sulfide (CuS), antimony pentasulfide (Sb 2 S 5 ), iron sulfide, tin sulfide, titanium sulfide, zirconium sulfide and niobium sulfide.
5. The method of claim 1 , wherein the catalyst comprises at least one of the following: palladium, silver, gold, tin and platinum.
6. The method of claim 1 , further comprising a step of removing excessive blocking reagent from the substrate by rinsing with deionized water.
7. The method of claim 1 , wherein the step of placing a blocking reagent is performed by at least one of the following: ink-jet printing, screen-printing, pad printing, gravure printing, photoresist masking, doctor blading, and roller coating.
8. The method of claim 1 , wherein the blocking reagent is mixed with a resin before being placed on the substrate.
9. The method of claim 1 , further comprising a step of curing the substrate with a blocking agent layer at a temperature of at least 100 degree Celsius.
10. The method of claim 1 , wherein the layer of the catalyst has an average thickness of less than 5 atoms of the catalyst.
11. The method of claim 1 , wherein the layer of the catalyst has an average thickness of less than 3 atoms of the catalyst.