Method and apparatus for forming an electrical connection to a semiconductor substrate
View Patent ↗A device ( 100 ) may use one or more conductive elements ( 112 ) to electrically couple a substrate ( 116 ) and a cap ( 114 ). In one embodiment, an acceleration sense element may be formed on the substrate ( 116 ), and the cap ( 114 ) may be used to provide hermetic protection to the acceleration sense element. In one embodiment, conductive elements ( 112 ) may be formed by dispensing conductive die attach material. Wire bonds (e.g. 322 ) bonded to bond pads (e.g. 332 ) on the substrate (e.g. 316 ) may be used to couple substrate ( 116 ), the conductive element pad ( 335 ), and the cap ( 114 ), to a desired predetermined potential.
1. A method for forming an electrical connection to a semiconductor substrate, comprising:
providing a pad on the semiconductor substrate;
placing a cap overlying the semiconductor substrate, wherein the cap has a top surface, and wherein the cap has a side edge which forms a non-perpendicular angle with respect to a top surface of the semiconductor substrate; and
forming a first conductive element to electrically couple the semiconductor substrate and the cap,
wherein the first conductive element overlies a first portion of the non-perpendicular angle, and
wherein no portion of the first conductive element is located on the top surface of the cap.
2. A method as in claim 1 , wherein the cap comprises at least a portion of a semiconductor wafer.
3. A method as in claim 1 , wherein the first conductive element comprises conductive die attach material.
4. A method as in claim 1 , further comprising: grinding the cap.
5. A method as in claim 4 , wherein grinding the cap reduces a thickness of the cap, and wherein no portion of the first conductive element is formed overlying the top surface of the cap after grinding.
6. A method as in claim 1 , further comprising:
forming a second conductive element to electrically couple the semiconductor substrate and the cap,
wherein the second conductive element overlies a second portion of the non-perpendicular angle.
7. A method as in claim 1 , wherein no conductive pads are located on the top surface of the cap.
8. A method as in claim 1 , wherein the pad on the semiconductor substrate comprises a bond pad for wire bonding.
9. A method as in claim 1 , wherein the step of forming the first conductive element comprises forming the first conductive element less than all of a way up the side edge of the cap from the top surface of the semiconductor substrate to the top surface of the cap.
10. A device, comprising:
a semiconductor substrate having a first bond pad;
a cap overlying the semiconductor substrate, the cap having a top surface and a side edge; and
a first conductive element disposed on at least a portion of the first bond pad and at least a first portion of the side edge of the cap to thereby electrically couple the semiconductor substrate to the cap,
wherein no portion of the first conductive element overlies the top surface of the cap.
11. A device as in claim 10 , wherein the first conductive element comprises conductive die attach.
12. A device as in claim 10 , wherein the first conductive element comprises a ball bond.
13. A device as in claim 10 , wherein the first conductive element comprises at least one material selected from a group consisting of a conductive adhesive, a conductive epoxy, and a metal.
14. A device as in claim 10 , wherein the device comprises a micro-electro-mechanical device.
15. A device as in claim 10 , wherein the cap hermetically seals at least a portion of the semiconductor substrate.
16. A device as in claim 10 , further comprising:
a second bond pad on a surface of the semiconductor substrate; and
a second conductive element disposed on at least a portion of the second bond pad and at least a second portion of the side edge of the cap to thereby electrically couple the semiconductor substrate to the cap.
17. A device as in claim 10 , further comprising:
a wire bond attached to the first bond pad.
18. A device as in claim 10 , wherein the side edge of the cap forms a non-perpendicular angle with a top surface of the semiconductor substrate, and wherein a thickness of the cap is reduced by etching the top surface of the cap.
19. A device as in claim 10 , wherein the first conductive element comprises no wire bonds.
20. A micro-electro-mechanical device, comprising:
a substrate comprising an acceleration sense element and a first bond pad;
a cap comprising at least a portion of a semiconductor wafer, said cap overlying the semiconductor substrate and providing hermetic protection for the acceleration sense element, said cap having a top surface devoid of bond pads; and
a conductive element disposed on at least a portion of the first bond pad and at least a first portion of the cap to thereby electrically couple the semiconductor substrate to the cap,
wherein the at least the portion of the first bond pad is formed in a first plane, wherein the at least the first portion of the cap is formed in a second plane that is different from the first plane, and wherein the first plane and the second plane are angled and not parallel with respect to each other.