Solder wettable flanges and devices and systems incorporating solder wettable flanges
View Patent ↗An embodiment of a solder wettable flange includes a flange body formed from a conductive material. The flange body has a bottom surface, a top surface, sidewalls extending between the top surface and the bottom surface, and one or more depressions extending into the flange body from the bottom surface. Each depression is defined by a depression surface that may or may not be solder wettable. During solder attachment of the flange to a substrate, the depressions may function as reservoirs for excess solder. Embodiments also include devices and systems that include such solder wettable flanges, and methods for forming the solder wettable flanges, devices, and systems.
1. A solder wettable flange comprising:
a flange body formed from a conductive material and having a bottom surface, a top surface, sidewalls extending between the top surface and the bottom surface, and one or more depressions extending into the body from the bottom surface, wherein each depression is defined by a depression surface, the bottom surface is solder wettable, and the sidewalls are non-solder wettable due to a feature selected from oxidation of the sidewalls, and the sidewalls being at least partially formed from a non-solder wettable material.
2. The solder wettable flange of claim 1 , wherein at least a portion of the depression surface is solder wettable.
3. The solder wettable flange of claim 1 , wherein at least one of the one or more depressions is an edge depression that extends between the bottom surface and a sidewall.
4. The solder wettable flange of claim 3 , wherein the edge depression is defined by one or more depression surfaces selected from a bevel, a chamfer, a concave surface, a convex surface, surfaces joined at an interior corner, and a combination of such surfaces.
5. The solder wettable flange of claim 3 , wherein the edge depression is a chamfer that extends between the bottom surface and the sidewall.
6. The solder wettable flange of claim 1 , wherein heights of the one or more depressions are in a range of 10 percent to 100 percent of a height of the solder wettable flange.
7. The solder wettable flange of claim 1 , wherein the flange body is formed from a single conductive material or a plurality of conductive material layers, including materials selected from copper, a copper alloy, silver, aluminum, molybdenum, and copper molybdenum.
8. The solder wettable flange of claim 1 , wherein the flange body is formed from a conductive material that is integrally combined with one or more other materials, wherein the conductive material is selected from copper, a copper alloy, silver, and aluminum, and the one or more other materials are selected from tungsten, molybdenum, diamond, graphite, and silicon carbide.
9. The solder wettable flange of claim 1 , wherein at least a portion of the flange body is plated with a plating material selected from silver, palladium, gold, copper, nickel, tin, lead tin, and a combination of said plating materials.
10. The solder wettable flange of claim 1 , wherein the flange body is a composite of a layer of copper defining the bottom surface, and a layer selected from molybdenum and copper molybdenum defining at least a portion of the sidewalls.
11. A solder wettable flange comprising:
a flange body formed from a conductive material and having a bottom surface, a top surface, sidewalls extending between the top surface and the bottom surface, and one or more depressions extending into the body from the bottom surface, wherein each depression is defined by a depression surface, wherein the bottom surface is solder wettable, and the depression surface is non solder wettable due to a feature selected from oxidation, and the depression surface being partially formed from a non-solder wettable material.
12. The solder wettable flange of claim 11 , wherein the flange body is a composite of a layer of copper defining the bottom surface, and a layer selected from molybdenum and copper molybdenum defining at least a portion of the depression surface.
13. A solder wettable flange comprising:
a flange body formed from a conductive material and having a bottom surface, a top surface, sidewalls extending between the top surface and the bottom surface, and one or more depressions extending into the body from the bottom surface, wherein each depression is defined by a depression surface, wherein at least one of the one or more depressions is a single surface depression that is located on the bottom surface, wherein a portion of the bottom surface is present between the single surface depression and an edge of the bottom surface.
14. The solder wettable flange of claim 13 , wherein the single surface depression is selected from an opening in the bottom surface and a trench in the bottom surface.
15. An electronic device comprising:
an electronic circuit;
a plurality of leads electrically coupled to the electronic circuit, wherein each of the plurality of leads includes an upper portion that is connected to the electronic circuit, and a lower portion; and
a solder wettable flange coupled to the electronic circuit and the plurality of leads, wherein the solder wettable flange is formed from a conductive material and has a bottom surface that is substantially co-planar with the lower portion of each of the plurality of leads, a top surface, sidewalls extending between the top surface and the bottom surface, and one or more depressions extending into the body from the bottom surface, wherein each depression is defined by a depression surface, the bottom surface is solder wettable, and the sidewalls are non-solder wettable due to a feature selected from oxidation of the sidewalls, and the sidewalls being at least partially formed from a non-solder wettable material.
16. The electronic device of claim 15 , wherein the circuit comprises components of a power amplifier.
17. The electronic device of claim 15 , wherein the circuit comprises at least one component that has a conductive contact coupled to the top surface of the solder wettable flange.
18. The electronic device of claim 15 , wherein the plurality of leads are gull wing leads.
19. The electronic device of claim 15 , wherein the one or more depressions are selected from one or more edge depressions, one or more single surface depressions, and combinations of edge depressions and single surface depressions.
20. The electronic device of claim 15 , wherein at least one of the one or more depressions is a chamfer that extends between the bottom surface and a sidewall.