Devices and methods for solder flow control in three-dimensional microstructures
View Patent ↗Structures, materials, and methods to control the spread of a solder material or other flowable conductive material in electronic and/or electromagnetic devices are provided.
1. An electronic microstructure, comprising:
a mounting surface having at least a portion thereof configured to bond to one or more of a metallic solder and a conductive epoxy;
a wick stop structure disposed away from the mounting surface at a location on the microstructure proximate the mounting surface, the wick stop structure configured to deter a flow of one or more of the metallic solder and the conductive epoxy from the mounting surface to a location on the microstructure beyond the location of the wick stop structure, wherein the wick stop structure comprises a shelf which extends outwardly away from a surface of the microstructure at which the shelf is located.
2. The electronic microstructure according to claim 1 , wherein the wick stop structure comprises a material which is non-wetting to metallic solder.
3. The electronic microstructure according to claim 1 , wherein the wick stop structure comprises a material which is non-wetting to conductive epoxy.
4. The electronic microstructure according to claim 1 , wherein the wick stop structure comprises a dielectric.
5. The electronic microstructure according to claim 1 , wherein the wick stop structure comprises a non-wetting metal.
6. The electronic microstructure according to claim 5 , wherein the non-wetting metal comprises nickel.
7. The electronic microstructure according to claim 1 , wherein the wick stop structure comprises a metal oxide.
8. The electronic microstructure according to claim 1 , wherein the shelf comprises a portion disposed within the microstructure.
9. The electronic microstructure according to claim 1 , wherein the shelf circumscribes a portion of the microstructure.
10. The electronic microstructure according to claim 1 , wherein the microstructure comprises a three-dimensional structure comprising multiple layers.
11. The electronic microstructure according to claim 10 , wherein the mounting surface is disposed at a first layer of the multiple layers and wherein the shelf is disposed at a second layer of the multiple layers, wherein the second layer is disposed over the first layer.
12. The electronic microstructure according to claim 11 , wherein the first and second layers are disposed in direct contact with one another.
13. The electronic microstructure according to claim 1 , wherein the microstructure comprises a three-dimensional structure formed by a multi-layer build process.
14. The electronic microstructure according to claim 1 , wherein the mounting surface comprises a raised surface to provide a mechanical stop between the mounting surface and a part to be mounted thereto.
15. The electronic microstructure according to claim 14 , wherein the raised surface provides a gap of predefined height between the raised surface and mounting surface.
16. The electronic microstructure according to claim 1 , wherein the metallic solder comprises a solder paste.
17. The electronic microstructure according to claim 1 , comprising a chip flip-chip mounted to the mounting surface.
18. The electronic microstructure according to claim 1 , comprising a surface mount component mounted to the mounting surface.
19. The electronic microstructure according to claim 1 , wherein the shelf has a longitudinal axis which is oriented substantially parallel to the mounting surface.
20. An electronic microstructure, comprising:
a mounting surface having at least a portion thereof configured to bond to one or more of a metallic solder and a conductive epoxy;
a wick stop structure disposed away from the mounting surface at a location on the microstructure proximate the mounting surface, the wick stop structure configured to deter a flow of one or more of the metallic solder and the conductive epoxy from the mounting surface to a location on the microstructure beyond the location of the wick stop structure, wherein the wick stop structure is disposed internal to the microstructure at a surface of the microstructure.
21. The electronic microstructure according to claim 20 , wherein the wick stop structure is recessed within the microstructure.
22. An electronic microstructure, comprising:
a mounting surface having at least a portion thereof configured to bond to one or more of a metallic solder and a conductive epoxy;
a wick stop structure disposed away from the mounting surface at a location on the microstructure proximate the mounting surface, the wick stop structure configured to deter a flow of one or more of the metallic solder and the conductive epoxy from the mounting surface to a location on the microstructure beyond the location of the wick stop structure, wherein the mounting surface comprises mounting feet to provide a G-S-G termination.
23. The electronic microstructure according to claim 22 , wherein the wick stop structure is disposed proximate the mounting feet.
24. An electronic microstructure, comprising:
a mounting surface having at least a portion thereof configured to bond to one or more of a metallic solder and a conductive epoxy;
a wick stop structure disposed away from the mounting surface at a location on the microstructure proximate the mounting surface, the wick stop structure configured to deter a flow of one or more of the metallic solder and the conductive epoxy from the mounting surface to a location on the microstructure beyond the location of the wick stop structure, wherein the microstructure comprises a coaxial microstructure.
25. A method of forming an electronic structure comprising:
(a) depositing a plurality of layers over a substrate, wherein the layers comprise one or more of a metal material, a sacrificial photoresist material, and a dielectric material, thereby forming an electronic structure above the substrate, the structure comprising the microstructure of claim 1 , wherein the wick stop structure comprises a selected one of the plurality of layers; and
(b) removing the microstructure from the substrate to provide a freestanding part.
26. The method according to claim 25 , wherein the wick stop structure comprises a material which is non-wetting to metallic solder.
27. The method according to claim 25 , wherein the wick stop structure comprises a material which is non-wetting to conductive epoxy.
28. The method according to claim 25 , wherein the wick stop structure comprises a dielectric.
29. The method according to claim 25 , wherein the wick stop structure comprises a non-wetting metal.
30. The method according to claim 29 , wherein the non-wetting metal comprises nickel.
31. The method according to claim 25 , wherein the wick stop structure comprises a metal oxide.
32. The method according to claim 25 , wherein the wick stop structure comprises a shelf which extends outwardly away from a surface of the microstructure at which the shelf is located.
33. The method according to claim 32 , wherein the shelf comprises a portion disposed within the microstructure.
34. The method according to claim 32 , wherein the shelf circumscribes a portion of the microstructure.
35. The method according to claim 25 , wherein the wick stop structure circumscribes a portion of the microstructure.
36. The method according to claim 25 , wherein the wick stop structure is disposed internal to the microstructure at a surface of the microstructure.
37. The method according to claim 36 , wherein the wick stop structure is recessed within the microstructure.
38. The method according to claim 25 , wherein the microstructure comprises a three-dimensional structure comprising multiple layers.
39. The method according to claim 25 , wherein the microstructure comprises a three-dimensional structure formed by a multi-layer build process.
40. The method according to claim 25 , wherein the mounting surface comprises a raised surface to provide a mechanical stop between the mounting surface and a part to be mounted thereto.
41. The method according to claim 25 , wherein the mounting surface comprises mounting feet to provide a G-S-G termination.
42. The method according to claim 41 , wherein the wick stop structure is disposed proximate the mounting feet.
43. The method according to claim 25 , wherein the microstructure comprises a coaxial microstructure.
44. The method according to claim 25 , wherein the metallic solder comprises a solder paste.
45. The method according to claim 25 , comprising a chip flip-chip mounted to the mounting surface.
46. The method according to claim 25 , comprising a surface mount component mounted to the mounting surface.