Solar powered IC chip
View Patent ↗A self-powered integrated circuit (IC) device includes a lead frame and a solar cell having first and second main surfaces. The solar cell is mounted on a surface of the lead frame. An IC chip is also provided. A first electrical interconnector electrically couples the IC chip to the lead frame and a second electrical interconnector electrically couples the solar cell to the IC chip. A portion of the first main surface of the solar cell is configured to receive light from an external source. The solar cell converts energy of the received light into electrical power that is supplied to the IC chip. A mold compound encapsulates the IC chip, the first and second electrical interconnectors, and at least a portion of the solar cell.
1. A self-powered integrated circuit (IC) device, comprising:
a lead frame having opposing first and second main surfaces, a chip support area with a center opening and a plurality of leads surrounding the chip support area;
a solar cell having opposing first and second main surfaces, wherein at least a portion of the first main surface of the solar cell is configured to receive light from an external source and the second main surface of the solar cell is attached to the chip support area of the first main surface of the lead frame with a portion of the second main surface of the solar cell exposed through the center opening of the chip support area, wherein the solar cell converts energy of the received light into electrical power;
an integrated circuit (IC) chip having opposing first and second main surfaces, the first main surface of the IC chip being mounted on the second main surface of the solar cell through the center opening of the chip support area, wherein the IC chip is electrically connected to the solar cell through the center opening to receive the electrical power generated by the solar cell;
at least one first electrical interconnector electrically connecting the leads of the lead frame with the IC chip; and
a first encapsulant that covers at least a portion of the lead frame, the IC chip, the at least one first electrical interconnector, and at least a portion of the solar cell.
2. The IC device of claim 1 , wherein the first encapsulant is transparent or transmissive to at least a wavelength of the received light and the first main surface of the solar cell is encapsulated therewith.
3. The IC device of claim 1 , wherein the first main surface of the IC chip is mounted on the second main surface of the solar cell with a non-conductive epoxy.
4. The IC device of claim 1 , wherein the at least one first electrical interconnector comprises a plurality of bond wires.
5. The IC device of claim 1 , wherein a surface area of the first main surface of the solar cell is larger than a surface area of the first main surface of the IC chip.
6. The IC device of claim 1 , further comprising a second encapsulant laminated on at least the light receiving portion of the first main surface of the solar cell, wherein the second encapsulant is transparent or transmissive to at least a wavelength of the received light.
7. The IC device of claim 6 , wherein the laminated portion of the first main surface of the solar cell is also laminated with glass.
8. The IC device of claim 6 , wherein at least the laminated portion of the first main surface of the solar cell is exposed through the first encapsulant.
9. The IC device of claim 1 , further comprising a plurality of second electrical interconnectors that electrically couple the solar cell to the second main surface of the IC chip.
10. The IC device of claim 9 , wherein the second electrical interconnectors comprise bond wires.
11. A self-powered integrated circuit (IC) device, comprising:
a lead frame having opposing first and second main surfaces, a chip support area with a center opening and a plurality of leads surrounding the chip support area;
a solar cell having opposing first and second main surfaces, wherein the first main surface of the solar cell is configured to receive light from an external source and the second main surface of the solar cell is attached on the chip support area of the first surface of the lead frame with a portion of the second main surface of the solar cell exposed through the center opening of the chip support area, and wherein the solar cell converts energy of the received light into electrical power;
an integrated circuit (IC) chip having opposing first and second main surfaces, the first main surface of the IC chip being in facing arrangement with the second main surface of the solar cell and mounted on the chip support area of the second main surface of the lead frame and electrically connected to the leads of the lead frame with solder balls, and wherein a portion of the first main surface of the IC chip is exposed and electrically connected to the second main surface of the solar cell through the center opening to receive the electrical power generated by the solar cell; and
a first encapsulant that covers the IC chip, and at least a portion of the solar cell.
12. The IC device of claim 11 , wherein the first encapsulant is transparent or transmissive to at least a wavelength of the received light, and the first main surface of the solar cell is encapsulated therewith.
13. The IC device of claim 11 , further comprising a second encapsulant laminated on at least the light receiving portion of the first main surface of the solar cell, wherein the second encapsulant is transparent or transmissive to at least a wavelength of the received light.
14. The IC device of claim 13 , wherein the laminated portion of the first main surface of the solar cell is also laminated with glass.
15. The IC device of claim 14 , wherein at least the laminated portion of the first main surface of the solar cell is exposed through the first encapsulant.
16. The IC device of claim 11 , further comprising a plurality of electrical interconnectors that electrically couple the solar cell to the IC chip.
17. The IC device of claim 16 , wherein the electrical interconnectors comprise solder balls.
18. A method of assembling a self-powered integrated circuit (IC) device, the method comprising:
mounting a solar cell having opposing first and second main surfaces on a chip support area of a first main surface of a lead frame, wherein the chip support area includes a center opening so that a portion of the second main surface of the solar cell is exposed through the center opening, and wherein at least a portion of the first main surface of the solar cell is configured to receive light from an external source, and wherein the solar cell converts received light to electrical power;
mounting an integrated circuit (IC) chip having opposing first and second main surfaces on the second main surface of the solar cell, wherein the first main surface of the IC chip is attached to the second main surface of the solar cell through the center opening of the chip support area;
electrically coupling, using at least one first electrical interconnector, the IC chip to a plurality leads of the lead frame;
electrically connecting the solar cell to the IC chip through the center opening of the chip support area so that that solar cell provides the electrical power to the IC chip; and
encapsulating, in a mold compound, the IC chip, the at least one first electrical interconnector, at least a portion of the leads of the lead frame, and at least a portion of the solar cell.
19. The method of claim 18 , further comprising laminating at least the light receiving portion of the first main surface of the solar cell with an encapsulant that is transparent or transmissive to at least a wavelength of the received light.