Thin substrate fabrication method and structure

1. A method of forming a package comprising:

forming a circuit pattern on a first carrier;

embedding the circuit pattern in a first surface of a dielectric material, a second surface of the dielectric material opposite the first surface being directly mounted on a second carrier, the embedding comprising causing the dielectric material to directly contact the first carrier and the second carrier, wherein the dielectric material remains between the circuit pattern and the second carrier;

removing the first carrier;

mounting a buildup dielectric material to the dielectric material and the circuit pattern;

forming laser-ablated artifacts in the buildup dielectric material;

filling the laser-ablated artifacts with an electrically conductive material to form a buildup circuit pattern; and

subsequent to the embedding, patterning the second carrier into a stiffener.

2. The method of claim 1 further comprising forming bond finger openings in the dielectric material, the bond finger openings exposing and defining lands of the circuit pattern.

3. The method of claim 2 further comprising attaching a die to the dielectric material.

4. The method of claim 3 wherein the attaching a die to the dielectric material comprises attaching an inactive surface of the die to the dielectric material with a die attach adhesive, the die further comprising an active surface comprising bond pads.

5. The method of claim 4 further comprising electrically connecting the bond pads to the lands with bond wires.

6. The method of claim 5 further comprising forming at least one electrically conductive blind via between the circuit pattern and the second carrier.

7. The method of claim 6 wherein the blind via is electrically connected to the stiffener, the stiffener comprising an electrically conductive material.

8. The method of claim 7 wherein the stiffener is connected to a reference voltage source through the blind via.

9. The method of claim 8 wherein the stiffener functions as a reference voltage source ring.

10. The method of claim 9 wherein the electrically connecting the bond pads to the lands with bond wires further comprises electrically connecting one or more of the bond pads to the stiffener with the bond wires.

11. The method of claim 5 further comprising encapsulating the stiffener, the die, the bond wires and an exposed portion of the dielectric material in a package body.

12. The method of claim 1 further comprising forming interconnection balls on the buildup circuit pattern.

13. The method of claim 1 further comprising:

forming bond finger openings in the dielectric material, the bond finger openings exposing and defining lands of the circuit pattern;

attaching an inactive surface of an image sensor die to the dielectric material with a die attach adhesive, the image sensor die further comprising an active surface comprising bond pads and an active area responsive to electromagnetic radiation;

electrically connecting the bond pads to the lands with bond wires; and

attaching a transparent window to the stiffener.

14. The method of claim 1 further comprising:

forming bond finger openings in the dielectric material, the bond finger openings exposing and defining lands of the circuit pattern; and

flip chip die attaching bond pads of a die to the lands with flip chip bumps.

15. The method of claim 7 wherein the electrically conductive material is selected from the group consisting of copper, copper invar copper, copper aluminum copper and copper alloys.

16. A method of forming a package comprising:

forming a circuit pattern on a first carrier;

embedding the circuit pattern in a first surface of a dielectric material, a second surface of the dielectric material opposite the first surface being directly mounted on a second carrier, the embedding comprising causing the dielectric material to directly contact the first carrier and the second carrier, wherein the dielectric material remains between the circuit pattern and the second carrier;

removing the first carrier;

mounting a buildup dielectric material to the dielectric material and the circuit pattern;

forming laser-ablated artifacts in the buildup dielectric material;

filling the laser-ablated artifacts with an electrically conductive material to form a buildup circuit pattern; and

subsequent to the embedding, patterning the second carrier into a stiffener, the stiffener comprising:

a rectangular body around a periphery of the package; and

fingers protruding inwards from the body towards a center of the package.

17. The method of claim 16 wherein the body comprises four sides and four corners.

18. The method of claim 17 wherein one of the fingers protrudes inwards from a middle of each of the sides.

19. The method of claim 18 wherein one of the fingers protrudes inwards from each of the corners.

20. The method of claim 19 wherein the fingers consist of eight fingers.

21. The method of claim 16 wherein each of the fingers extends from the body with a uniform width.

22. A method of forming a package comprising:

forming a circuit pattern on a first carrier;

embedding the circuit pattern in a first surface of a dielectric material, a second surface of the dielectric material opposite the first surface being directly mounted on a second carrier, the embedding comprising causing the dielectric material to directly contact the first carrier and the second carrier, wherein the dielectric material remains between the circuit pattern and the second carrier;

removing the first carrier;

mounting a buildup dielectric material to the dielectric material and the circuit pattern;

forming laser-ablated artifacts in the buildup dielectric material;

filling the laser-ablated artifacts with an electrically conductive material to form a buildup circuit pattern; and

subsequent to the embedding, patterning the second carrier into a stiffener, the stiffener comprising:

a rectangular body around a periphery of the package; and

fingers protruding inwards from the body, the fingers comprising:

a first finger having a uniform width; and

at least one tapered finger.

23. The method of claim 22 wherein the body comprises:

a first side having the first finger extending from a middle of the first side;

a second side having three of the tapered fingers extending inward therefrom;

a third side having three of the tapered fingers extending inward therefrom; and

a fourth side having an absence of the fingers.