Optical die-down quad flat non-leaded package
View Patent ↗An optical sensor package that includes an optical sensor die is mounted by flip chip interconnect onto a lead frame in a “die-down” orientation, that is, with the active side of the optical sensor die facing the lead frame. An opening is provided in the lead frame die paddle (pad), and light passes from outside the package through the opening in the lead frame die pad onto light collection elements on the active side of the chip.
1. A low-profile optical sensor package, comprising:
a leadframe having a die pad and interconnect leads electrically isolated from and surrounding the die pad, the die pad having an opening centrally located with respect to a surface area of the die pad;
a semiconductor die mounted to the die pad, the semiconductor die having an optically active surface facing the die pad and aligned to the opening;
a barrier layer disposed around the opening and connecting the semiconductor die and die pad;
an encapsulant covering a portion of the semiconductor die and leadframe, wherein the barrier layer isolates the encapsulant from the optically active surface of the semiconductor die; and
a light-transmitting cover disposed across the opening in the die pad;
wherein the low-profile optical sensor package has a thickness of less than 0.7 millimeters.
2. The low-profile optical sensor package of claim 1 , wherein the barrier layer includes an adhesive material.
3. The low-profile optical sensor package of claim 1 , wherein the opening is circular or rectangular.
4. The low-profile optical sensor package of claim 1 , wherein the optically active surface includes a charge-coupled image sensor.
5. The low-profile optical sensor package of claim 1 , wherein the optically active surface includes a monochrome image sensor.
6. The low-profile optical sensor package of claim 1 , wherein the light-transmitting cover reduces the intensity of light transmitted through the opening to the optically active surface of the semiconductor die.
7. The low-profile optical sensor package of claim 1 , wherein the semiconductor die includes an electronic circuit coupled to the optically active surface of the semiconductor die.
8. The low-profile optical sensor package of claim 1 , wherein the die pad is etched to retain the light-transmitting cover.
9. The low-profile optical sensor package of claim 1 , wherein the low-profile optical sensor package is a quad flat non-leaded package.
10. A semiconductor package, comprising:
a leadframe having a die pad and interconnect leads electrically isolated from the die pad, the die pad having a centrally located opening;
a semiconductor die mounted to the die pad, the semiconductor die having an optically active surface facing the die pad and aligned to the centrally located opening;
a barrier layer disposed around the centrally located opening and connecting the semiconductor die and die pad;
an encapsulant covering a portion of the semiconductor die and leadframe, wherein the barrier layer isolates the encapsulant from the optically active surface of the semiconductor die; and
a light-transmitting cover disposed across the centrally located opening in the die pad, wherein the die pad is etched to retain the light-transmitting cover.
11. The semiconductor package of claim 10 , wherein the semiconductor package has a thickness of less than 0.7 millimeters.
12. The semiconductor package of claim 10 , wherein the barrier layer includes an adhesive material.
13. The semiconductor package of claim 10 , wherein the centrally located opening is circular or rectangular.
14. The semiconductor package of claim 10 , wherein the optically active surface includes a charge-coupled image sensor.
15. The semiconductor package of claim 10 , wherein the light-transmitting cover reduces the intensity of light transmitted through the centrally located opening to the optically active surface of the semiconductor die.
16. The semiconductor package of claim 10 , wherein the semiconductor die includes an electronic circuit coupled to the optically active surface of the semiconductor die.
17. The semiconductor package of claim 10 , wherein the semiconductor package is a quad flat non-leaded package.
18. An optical semiconductor package, comprising:
a leadframe having a die pad and interconnect leads electrically isolated from the die pad, the die pad having an opening;
a semiconductor die mounted to the die pad, the semiconductor die having an optically active surface facing the die pad and aligned to the opening;
a barrier layer disposed around the opening and connecting the semiconductor die and die pad;
an encapsulant covering a portion of the semiconductor die and leadframe, wherein the barrier layer isolates the encapsulant from the optically active surface of the semiconductor die; and
a light-transmitting cover disposed across the opening in the die pad, wherein the die pad is etched to retain the light-transmitting cover.
19. The optical semiconductor package of claim 18 , wherein the semiconductor package has a thickness of less than 0.7 millimeters.
20. The optical semiconductor package of claim 18 , wherein the barrier layer includes an adhesive material.
21. The optical semiconductor package of claim 18 , wherein the optical semiconductor package is a quad flat non-leaded package.
22. An optical semiconductor package, comprising:
a leadframe having a die pad and interconnect leads electrically isolated from the die pad, the die pad having an opening;
a semiconductor die mounted to the die pad, the semiconductor die having an optically active surface facing the die pad and aligned to the opening;
a barrier layer disposed around the opening and connecting the semiconductor die and die pad; and
an encapsulant covering a portion of the semiconductor die and leadframe, wherein the barrier layer isolates the encapsulant from the optically active surface of the semiconductor die.
23. The optical semiconductor package of claim 22 , further including a light-transmitting cover disposed across the opening in the die pad.
24. The optical semiconductor package of claim 23 , wherein the die pad is etched to retain the light-transmitting cover.
25. The optical semiconductor package of claim 23 , wherein the light-transmitting cover reduces the intensity of light transmitted through the opening to the optically active surface of the semiconductor die.
26. The optical semiconductor package of claim 22 , wherein the semiconductor package has a thickness of less than 0.7 millimeters.
27. The optical semiconductor package of claim 22 , wherein the semiconductor package is a quad flat non-leaded package.