Methods of forming printed circuit boards

1. A method of forming a printed circuit board having optical functionality, comprising:

(a) providing a first, printed circuit board substrate;

(b) forming an optical waveguide structure comprising a clad and a core structure on a second substrate, separate from the printed circuit board substrate, wherein the optical waveguide structure comprises a polymer comprising units of the formula (R 1 SiO 1.5 ), wherein R 1 is a substituted or unsubstituted organic group, comprising:

forming a first clad layer on the second substrate;

forming on the first clad layer a core layer from a composition comprising:

units of the formula (R 1 SiO 1.5 ) and a plurality of functional end groups;

and a first component for altering the solubility of the composition upon exposure to actinic radiation;

exposing a portion of the core layer to actinic radiation;

developing the core layer, thereby forming the core structure; and

forming a second clad layer on the first clad layer and core structure;

(c) separating the optical waveguide structure from the second substrate; and

(d) affixing the optical waveguide structure to the printed circuit board substrate.

2. The method of claim 1 , wherein the silicon-containing polymer further comprises units of the formula (R 2 SiO 1.5 ), wherein R 1 is a substituted or unsubstituted alkyl group and R 2 is a substituted or unsubstituted aryl group.

3. The method of claim 1 , wherein the second substrate is formed of glass.

4. The method of claim 1 , wherein (b) further comprises providing a release layer between the second substrate and the optical waveguide structure.

5. A method of forming a printed circuit board having optical functionality, comprising:

(a) providing a first, printed circuit board substrate;

(b) forming an optical waveguide structure comprising a clad and a core structure on a second substrate, separate from the printed circuit board substrate, wherein the optical waveguide structure comprises a polymer comprising units of the formula (R 1 SiO 1.5 ), wherein R 1 is a substituted or unsubstituted organic group, and wherein formation of the core structure comprises:

(b1) forming a core layer from a composition comprising units of the formula (R 1 SiO 1.5 ) and a plurality of functional end groups; and a first component for altering the solubility of the composition upon exposure to actinic radiation;

(b2) exposing a portion of the core layer to actinic radiation; and

(b3) developing the core layer, thereby forming the core structure; and

(b4) forming a first clad layer on the second substrate and the core structure;

(c) separating the optical waveguide structure from the second substrate;

(d) forming a second clad layer on the printed circuit board substrate; and

(e) affixing the first clad layer and core structures to the second clad layer.

6. The method of claim 5 , wherein (b) further comprises providing a release layer between the second substrate and the optical waveguide structure.

7. The method of claim 5 , wherein the silicon-containing polymer further comprises units of the formula (R 2 SiO 1.5 ), wherein R 1 is a substituted or unsubstituted alkyl group and R 2 is a substituted or unsubstituted aryl group.

8. A method of forming a printed circuit board having optical functionality, comprising:

(a) providing a first, printed circuit board substrate;

(b) forming an optical waveguide structure comprising a clad and a core structure on a second substrate, separate from the printed circuit board substrate, wherein a release layer is provided between the second substrate and the optical waveguide structure, wherein the optical waveguide structure comprises a polymer comprising units of the formula (R 1 SiO 1.5 ), wherein R 1 is a substituted or unsubstituted organic group, and wherein formation of the core structure comprises:

(b1) forming a core layer from a composition comprising units of the formula (R 1 SiO 1.5 ) and a plurality of functional end groups; and a first component for altering the solubility of the composition upon exposure to actinic radiation;

(b2) exposing a portion of the core layer to actinic radiation; and

(b3) developing the core layer, thereby forming the core structure;

(c) separating the optical waveguide structure from the second substrate; and

(d) affixing the optical waveguide structure to the printed circuit board substrate.

9. The method of claim 8 , wherein (b) comprises:

forming a first clad layer on the second substrate;

forming the core layer and core structure on the first clad layer; and

forming a second clad layer on the printed circuit board substrate prior to (d), and wherein (d) comprises affixing the first clad layer and the core structure to the second clad layer.

10. The method of claim 8 , wherein the silicon-containing polymer further comprises units of the formula (R 2 SiO 1.5 ), wherein R 1 is a substituted or unsubstituted alkyl group and R 2 is a substituted or unsubstituted aryl group.

11. A method of forming a printed circuit board having optical functionality, comprising:

(a) providing a first, printed circuit board substrate;

(b) forming an optical waveguide structure comprising a clad and a core structure on a second substrate, separate from the printed circuit board substrate, wherein the optical waveguide structure comprises a polymer comprising units of the formula (R 1 SiO 1.5 ), wherein R 1 is a substituted or unsubstituted organic group, and wherein formation of the core structure comprises:

(b1) forming a core layer from a composition comprising units of the formula (R 1 SiO 1.5 ) and a plurality of functional end groups; and a first component for altering the solubility of the composition upon exposure to actinic radiation;

(b2) exposing a portion of the core layer to actinic radiation; and

(b3) developing the core layer, thereby forming the core structure;

(c) contacting the second substrate and optical waveguide structure with heated water to separate the optical waveguide structure from the second substrate; and

(d) affixing the optical waveguide structure to the printed circuit board substrate.

12. The method of claim 11 , wherein (b) further comprises providing a release layer between the second substrate and the optical waveguide structure.

13. The method of claim 11 , wherein the silicon-containing polymer further comprises units of the formula (R 2 SiO 1.5 ), wherein R 1 is a substituted or unsubstituted alkyl group and R 2 is a substituted or unsubstituted aryl group.