Image sensor device
View Patent ↗An image sensor device is made using an ultra-thin substrate so that the overall device height is less than 1.0 mm. The image sensor includes a flexible circuit substrate having first and second opposing sides, the first side having a central area and an outer, bonding pad area including bonding pads. A sensor integrated circuit (IC) is attached to the central area of the first side of the circuit substrate. The IC has an active area and a peripheral bonding pad area including bonding pads. Wires are wirebonded to respective ones of the IC bonding pads and corresponding ones of the circuit substrate bonding pads to electrically connect the IC and the circuit substrate. A wall having a first end with a step and a second end has its second end attached to an outer portion beyond the outer bonding pad area of the first side of the flexible circuit substrate. The wall at least partially surrounds the sensor integrated circuit. A transparent cover is located above the IC such that light can pass through the cover onto the IC active area. Opposing edges of the cover are secured within the step of the wall. Solder balls are attached to the second side of the circuit substrate. The circuit substrate provides for electrical interconnect between the solder balls and the bonding pads on the first side of the circuit substrate.
1. An image sensor device, comprising:
a flexible circuit substrate having first and second opposing sides, the first side having a central area and an outer, bonding pad area including bonding pads;
a sensor integrated circuit (IC) attached to the central area of the first side of the circuit substrate, the IC having an active area and a peripheral bonding pad area, the peripheral bonding pad area including bonding pads;
a plurality of wires wirebonded to respective ones of the IC bonding pads and corresponding ones of the circuit substrate bonding pads, thereby electrically connecting the IC and the circuit substrate;
a wall having a first end and a second end, the second end attached to an outer portion beyond the outer bonding pad area of the first side of the flexible circuit substrate, wherein the wall at least partially surrounds the sensor integrated circuit; and
a transparent cover located above the sensor integrated circuit such that light can pass through the cover onto the IC active area, wherein the cover has a top side and a bottom side with channels formed at edges thereof, wherein at least a portion of a top surface of the wall is received within said channels.
2. The image sensor device of claim 1 , further comprising solder balls attached to the second side of the circuit substrate, wherein the circuit substrate provides for electrical interconnect between the solder balls and the bonding pads on the first side of the circuit substrate.
3. The image sensor device of claim 2 , wherein the solder balls have a height of less than about 400 um.
4. The image sensor device of claim 2 , wherein the image sensor device has a thickness of less than about 1.3 mm.
5. The image sensor device of claim 2 , wherein the image sensor device has a thickness of less than about 1.0 mm.
6. The image sensor device of claim 1 , wherein the wall is formed of a metal.
7. The image sensor device of claim 1 , wherein the wall is formed of BT.
8. The image sensor device of claim 1 , wherein the transparent cover comprises borosilicate glass having a thickness of less than 0.4 mm.
9. The image sensor device of claim 1 , wherein the IC is attached to the circuit substrate with an adhesive layer having a thickness of about 12 um.
10. The image sensor device of claim 1 , wherein the circuit substrate comprises:
a polyimide layer having top and bottom surfaces;
an adhesive layer overlying the top surface of the polyimide layer;
a conductive trace layer overlying the adhesive layer; and
a mask layer overlying the conductive trace layer, wherein a top surface of the mask layer forms the first side of the circuit substrate and the bottom surface of the polyimide layer forms the second side of the circuit substrate.
11. The image sensor device of claim 10 , wherein the adhesive layer has a thickness of about 12 um.
12. The image sensor device of claim 11 , wherein the mask layer has a thickness of about 30 um and the conductive trace layer has a thickness of between about 12 um to about 30 um.
13. The image sensor device of claim 12 , wherein the polyimide layer has a thickness of about 50 um.
14. The image sensor device of claim 13 , wherein the conductive layer is formed of copper and the mask layer comprises a solder mask.
15. An image sensor device, comprising:
a flexible circuit substrate having first and second opposing sides, the first side having a central area and an outer, bonding pad area including bonding pads;
a sensor integrated circuit (IC) attached to the central area of the first side of the circuit substrate, the IC having an active area and a peripheral bonding pad area, the peripheral bonding pad area including bonding pads;
a plurality of wires wirebonded to respective ones of the IC bonding pads and corresponding ones of the circuit substrate bonding pads, thereby electrically connecting the IC and the circuit substrate;
a wall having a first end and a second end, the second end attached to an outer portion beyond the outer bonding pad area of the first side of the flexible circuit substrate, wherein the wall at least partially surrounds the sensor integrated circuit;
a transparent cover comprising borosilicate glass attached to the IC with a clear adhesive; and
a clear epoxy disposed between the glass and the wall, wherein the epoxy covers the wires.
16. The image sensor device of claim 15 , wherein the wall is formed with soft epoxy.