Overmolded device with contoured surface
View Patent ↗An electronic device has three dimensional surface features molded into an encapsulant forming an electronic package. The electronic package has improved heat transfer compared to conventional electronic devices. The three dimensional features are designed to be moldable.
1. An electronic device comprises at least one high heat generating electronic component and at least one low heat generating electronic component; at least one surface mountable electrical connection electrically connected to the at least one high heat generating electronic component; and a moldable encapsulant sealing the at least one high heat generating component and the at least one low heat generating electronic component within an electronic package, wherein at least a portion of the at least one electrical connection extends outside of the electronic package and the encapsulant has at least one surface that has at least one indentation defining a plurality of three dimensional surface features, each of the surface features being defined by the at least one indentation and an exterior surface of the electronic package and wherein the at least one high heat generating component is adjacent to the at least one indentation, and the at least one low electronic component is not adjacent to the at least one indentation.
2. The electronic device of claim 1 , wherein the at least one indentation comprises a trough having two side walls meeting a lower surface at an angle greater than 90° to the lower surface and at least one end wall positioned between the two side walls and meeting both the lower surface and the two side walls at an angle greater than 90°.
3. The electronic device of claim 2 , wherein the trough extends from a single end wall to an opening on the external surface of the electronic package.
4. The electronic device of claim 1 , wherein the at least one indentation forms a continuous lower surface defining a plurality of isolated three dimensional surface features.
5. The electronic device of claim 4 , wherein the plurality of isolated three dimensional surface features are pins.
6. The electronic device of claim 4 , wherein the isolated three dimensional surface features are pyramidal pins having a wider base than a tip.
7. The electronic device of claim 4 , wherein the isolated three dimensional surface features are conical pins having a larger base radius than a tip radius.
8. An electronic device comprising a printed circuit board having at least one heat generating electronic component and at least one tall electronic component, taller than the at least one heat generating component, and the at least one tall electronic component generates less heat than the at least one heat generating electronic component, at least one surface mountable electrical connection electrically connected to the at least one heat generating electronic component; and a moldable encapsulant sealing the at least one heat generating component within an electronic package, wherein at least a portion of the at least one electrical connector extends outside of the electronic package and the encapsulant has at least one surface that has at least one indentation defining a plurality of three dimensional surface features, each of the surface features being defined by the at least one indentation and an exterior surface of the electronic package, wherein the at least one tall electronic component and the at least one heat generating component are positioned on the printed circuit board such that at least a portion of the at least one heat generating component is adjacent to the at least one indentation, and the at least one tall electronic component is not under the at least one indentation, is taller than the lower surface of the at least one indentation, and is sealed within the encapsulant.
9. The electronic device of claim 8 , wherein the at least one heat generating electronic component comprises two MOSFETs.
10. The electronic device of claim 9 , wherein the at least one tall electronic component comprises an inductor.
11. The electronic device of claim 3 , wherein the at least one indentation is two indentations, defining three fins.
12. The electronic device of claim 3 , wherein the at least one indentation is three indentations, defining four fins.
13. The electronic device of claim 12 , wherein the four fins consist of two outer fins, each defined by the exterior surface of the encapsulant and one of the three indentations and two inner fins, each defined by two of the three indentations that are adjacent and an upper surface of each of the two inner fins defined by the exterior surface of the encapsulant.
14. The electronic device of claim 13 , wherein the width and position of each of the two inner fins are selected to optimize the heat transfer from the at least one heat generating component.