1. A device for electrokinetic transport of an aqueous solute, comprising an electrically insulating substrate;
a conductor element for electrokinetic transport of the solute, the conductor element being in the form of a solid hydrophilic-matrix layer on the substrate, the matrix layer being in a substantially dry, inactive state wherein electrokinetic transport is substantially prevented and having a first surface engaging the substrate and a second surface; and
a cover layer for electrically insulating and covering the second surface, the cover layer being impermeable to the solute;
whereby exposure of the hydrophilic matrix to water converts the matrix from the inactive state to a hydrated, active state permitting electrokinetic transport of the solute.
2. The device of claim 1, further comprising a means for introducing water into the conductor element.
3. The device of claim 2, further comprising a means for introducing the aqueous solute into the conductor element.
4. The device of claim 1, wherein the solid hydrophilic-matrix layer is micro-fabricated onto the substrate.
5. The device of claim 1, wherein the solid hydrophilic-matrix layer is a dry reagent film.
6. The device of claim 1, wherein the cover layer is micro-fabricated onto the conductor element and the substrate.
7. The device of claim 1, wherein at least one of the cover layer and the substrate has at least one portion which is permeable to water vapor.
8. The device of claim 1, further including a pair of spaced apart electrodes in electric contact with the conductor element at spaced apart locations for applying an electric potential across the conductor element.
9. The device of claim 8, wherein the electrodes are applied to the substrate and the device further includes an insulator layer for electrically insulating each electrode, the insulator layer having an opening in each region of overlap between one of the electrodes and the conductor element for permitting electric contact of the conductor element with the integral electrodes for electrokinetic pumping.
10. The device of claim 1, wherein the substrate is made of electrically insulating material.
11. The device of claim 1, wherein the substrate includes a layer of electrically conductive material and a layer of electrically insulating material intermediate the layer of conductive material and the conductor element.
12. The device of claim 1, wherein one of the substrate and the cover layer has a pair of openings for input and output of the solute species to be transported through the conductor element.
13. A device for electrokinetic transport of an aqueous solute, comprising an electrically insulating substrate;
a conductor element in the form of a solid hydrophilic-matrix layer on the substrate, the matrix layer being in a substantially dry, inactive state and having a first surface engaging the substrate and a second surface;
a cover layer for electrically insulating and covering the second surface, the cover layer being impermeable to the solute, but having at least one permeable portion in contact with the conductor element which is permeable to water vapor; and
whereby exposure of the permeable portion to water leads to hydration of the hydrophilic matrix converting the matrix from the inactive state to a hydrated, active state permitting electrokinetic transport of the solute in the conductor element.
14. The device of claim 13 for performing at least one of electrokinetic species transport or separation and a chemical reaction, wherein the hydrophilic matrix is formed by dry processing technology.
15. The device of claim 14, wherein the substrate is planar and the conductor element is a formed hydrophilic matrix film deposited onto the substrate.
16. The device of claim 13, wherein the hydrophilic matrix is substantially dry when deposited onto the substrate.
17. The device of claim 13, wherein the permeable portion is shaped and constructed for permitting permeation of water vapor into the conductor element either before or during use of the device.
18. The device of claim 13, wherein the hydrophilic matrix is formed from a film on a planar substrate.
19. The device of claim 1, comprising at least one region for introducing the solute for one of transport, separation and chemical reaction within the conductor element, and a separate means for introducing water only into the conductor element.
20. The device of claim 8, further comprising an input region for supply of solute into the conductor element and an output region spaced apart therefrom for removal of transported solute from the conductor element.
21. The device of claim 20, wherein the hydrophilic matrix of the conductor element is water insoluble in the input and output regions.
22. The device of claim 21, wherein the conductor element further comprises a reservoir region intermediate the input and output regions and including at least one chemical reactant for interaction with the transported solute.
23. The device of claim 22, further comprising an electrode for applying an electric potential to the reservoir region.
24. The device of claim 22, wherein the conductor element includes a plurality of the reservoir regions.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A method of forming a capped chip including a conductive interconnect extending vertically through a cap thereof, comprising:
providing a cap having an outer surface, an inner surface opposite said outer surface, and a plurality of through holes extending between said outer and inner surfaces;
aligning and joining said cap to a chip having a front face, a device region at said front face and a plurality of bond pads exposed at said front face, such that said inner surface of said cap faces said front face of said chip;
positioning a mass of fusible conductive material through a first through hole of said plurality of through holes onto a first bond pad of said plurality of bond pads; and
heating said positioned mass of fusible conductive material, such that said mass bonds to said first bond pad, said steps of positioning and heating said mass of fusible conductive material forming at least a portion of a conductive interconnect extending from said first bond pad at least partially through said first through hole.
2. The method as claimed in claim 1, wherein said step of aligning and joining said cap to said chip includes providing a sealing medium between said front face of said chip and said inner surface of said cap, wherein said sealing medium separates said device region from said plurality of bond pads.
3. The method as claimed in claim 2, wherein said step of positioning said mass of fusible conductive material includes dispensing a ball-shaped mass of said fusible conductive material, and said fusible conductive material includes at least one material selected from the group consisting of solder, tin and a eutectic composition.
4. The method as claimed in claim 3, wherein said cap consists essentially of a material which is not wettable by said fusible conductive material and said non-wettable material is exposed at walls of said plurality of through holes such that said step of heating said positioned mass does not wet said wall of said first through hole.
5. The method as claimed in claim 4, wherein said walls of said plurality of through holes extend in a substantially vertical direction perpendicular to said outer face of said cap.
6. The method as claimed in claim 5, wherein said walls of said plurality of through holes extend at an angle of less than 30 degrees from a direction perpendicular to said outer face of said cap.
7. The method as claimed in claim 3, further comprising after aligning and joining said cap to said chip, forming wettable layers on said plurality of bond pads and on walls of said plurality of through holes, wherein said step of heating said positioned mass wets said first bond pad and wets a first wall of said first through hole.
8. The method as claimed in claim 3, further comprising, prior to aligning and joining said cap to said chip, forming wettable layers on said plurality of bond pads and on walls of said plurality of through holes, wherein said step of heating said positioned mass wets said first bond pad and wets a first wall of said first through hole.
9. The method as claimed in claim 1, wherein said step of positioning said mass includes using a gas to direct said mass towards said first bond pad.
10. The method as claimed in claim 1, wherein said step of heating said positioned mass includes directing light from a laser onto said positioned mass until said positioned mass bonds with said first bond pad.
11. The method as claimed in claim 1, further comprising positioning a second mass of said fusible conductive material in contact with said bonded mass and heating said second mass until said second mass bonds with said bonded mass, thereby increasing a height of said conductive interconnect above said first bond pad.
12. The method as claimed in claim 1, wherein said mass of fusible conductive material is a first mass, said method further comprising,
after heating said first mass to bond said first mass to said first bond pad, positioning a second mass of fusible conductive material through a second through hole of said plurality of through holes onto a second bond pad of said plurality of bond pads; and
heating said second mass such that said heated second mass bonds to said second bond pad, said steps of positioning and heating said second mass forming at least a portion of a second conductive interconnect extending from said second bond pad at least partially through said second through hole.
13. The method as claimed in claim 1, wherein said mass is a first mass, and said step of positioning said mass includes simultaneously positioning a second mass of said fusible conductive material through a second through hole of said plurality of through holes onto a second bond pad of said plurality of bond pads, and said step of heating said mass includes simultaneously heating said positioned second mass of fusible conductive material, such that said second mass bonds to said second bond pad to form at least a portion of a second conductive interconnect extending from said second bond pad at least partially through said second through hole.
14. The method as claimed in claim 13, wherein said steps of positioning and heating said first mass, and positioning and heating said second mass are performed sequentially at a time when said chip remains attached to other chips in form of at least a portion of a wafer.
15. The method as claimed in claim 13, further comprising, performing the following steps in sequential order for each ith bond pad of said plurality of bond pads, after heating said second mass to bond said second mass to said second bond pad,
positioning an ith mass of fusible conductive material through an ith through hole of said plurality of through holes onto said ith bond pad; and
heating said ith mass such that said heated ith mass bonds to said ith bond pad, said steps of positioning and heating said ith mass forms at least a portion of an ith conductive interconnect extending from said ith bond pad at least partially through said ith through hole.
16. The method as claimed in claim 1, wherein said inner surface of said cap is spaced from said front face of said chip by a first vertical separation distance and a width of said positioned mass is greater than said first vertical separation distance.
17. The method as claimed in claim 13, wherein said step of positioning said second mass includes dispensing said fusible conductive material in a second nominal volume exceeding a first nominal volume of said first mass by more than 20%.
18. The method as claimed in claim 16, wherein a width of said first through hole at said inner surface is greater than said vertical separation distance.
19. The method as claimed in claim 16, wherein a thickness of said cap between said inner and outer surfaces is greater than a width of first through hole at said inner surface.
20. The method as claimed in claim 17, wherein said second nominal volume is dispensed in said step of positioning said second mass by an apparatus which positions and heats said first nominal volume, said second nominal volume being determined by adjusting said apparatus according to at least one of a width of said second through hole and a vertical separation distance between said inner surface of said cap and said front surface of said chip at said second through hole.
21. A method of fabricating a microelectronic device, comprising:
(a) assembling a cap element with a wafer element having a front face including a plurality of regions, each such region including an active area and a plurality of bond pads exposed at the front face outside of the active area, so that the cap element overlies the front face of the wafer element, the cap element having a plurality of openings extending from an outer surface of the cap element to an inner surface of the cap element; then
(b) positioning and bonding a first mass of fusible conductive material through a first opening of the plurality of openings onto a first bond pad of the plurality of bond pads;
(c) positioning and bonding a second mass of fusible conductive material through one or more of the plurality of openings;
(d) repeating steps (b) and (c) a plurality of times; and
(e) severing the wafer element and the cap element along severance lines to thereby form a plurality of capped units, the capped units including a plurality of conductive interconnects, the conductive interconnects including the first and second bonded masses.
22. The method as claimed in claim 21, wherein the steps (b) and (c) are performed sequentially to the first bond pad and to a second bond pad of the plurality of bond pads.
23. The method as claimed in claim 21, wherein the steps (b) and (c) are performed sequentially to bond the second mass through the first opening to the first mass to form stacked masses including the first mass and the second mass bonded to the first mass.
24. The method as claimed in claim 21, wherein each of the steps (b) and (c) are performed simultaneously to the first bond pad and to a second bond pad of the plurality of bond pads using a tool which heats the first mass individually to cause the first mass to bond to the first bond pad and using a tool which heats the second mass individually to cause the second mass to bond to the second bond pad.
25. The method as claimed in claim 21, wherein each of the steps (b) and (c) are performed simultaneously to the first bond pad and to a second bond pad of the plurality of bond pads by providing a combined mass of the fusible material including the first and second masses to a combined opening in which the first and second bond pads are exposed and causing the combined mass to melt and simultaneously bond to the first and second bond pads, wherein the step (e) of severing the wafer element and the cap element severs the combined mass to form a first conductive interconnect extending from the first bond pad of a first chip and a second conductive interconnect extending from a second bond pad of a second chip.
26. A device, comprising:
a chip having a front face having a plurality of peripheral edges, said chip including an active region and a plurality of bond pads exposed in a bond pad region at said front face;
a cap overlying said front face, said cap having an inner surface facing said front face, an outer surface opposite said inner surface, and a plurality of through holes extending between said inner and outer surfaces, said cap being mounted to said chip and spaced therefrom to define a void; and
a plurality of electrically conductive interconnects, each including a fusible conductive material, bonded to said plurality of bond pads and extending at least partially through said through holes, wherein said plurality of electrically conductive interconnects includes stacked columns of two or more masses of said fusible conductive material in ones of said plurality of through holes.
27. The device as claimed in claim 26, further comprising a seal extending between said cap and said chip over a portion of said chip between said active region and said bond pad region.
28. The device as claimed in claim 27, wherein said seal extends to outer portions of said front face extending between said bond pad region and said peripheral edges.
29. An assembly comprising a device as claimed in claim 26 and a substrate having a front surface and one or more terminals exposed at said front surface, said front face of said chip facing toward said front surface of said substrate, said stacked columns of two or more masses of said fusible conductive material being bonded to said one or more terminals of said substrate.
30. The assembly as claimed in claim 29, wherein said substrate includes a dielectric element and a plurality of metal wiring patterns exposed at said front surface.
31. The assembly as claimed in claim 30, wherein said dielectric element includes at least one material selected from the group consisting of BT resins, FR-4 composites, epoxies, ceramics, polyimide or glasses.
32. A microelectronic assembly, comprising:
a microelectronic device, said device including:
(a) a chip having a front surface and a rear surface, said front surface including an active region and a plurality of contacts exposed at said front surface outside of said active region;
(b) a cap overlaying said front surface of said chip, said cap having an inner surface adjacent to said front surface, an outer surface remote from said inner surface and edges bounding said cap, at least one of said edges including one or more outer portions and one or more recesses extending laterally inward from said outer portions, said contacts being aligned with said recesses and exposed within said recesses; and
(c) a plurality of conductive interconnects bonded to said contacts, said conductive interconnects extending from said contacts in a direction towards said outer surface; and
a circuit panel having a first surface and a plurality of terminals exposed at said first surface bonded to said contacts of said chip through said conductive interconnects, said microelectronic device positioned such that said outer surface of said cap faces said first surface of said circuit panel.
33. The microelectronic assembly as claimed in claim 32, wherein said conductive interconnects include masses of a fusible conductive material bonded to said contacts.
34. The microelectronic assembly as claimed in claim 33, wherein said masses are first masses, said microelectronic device further comprising second masses of a fusible conductive material bonded to at least some of said first masses of fusible conductive material to form stacked masses, at least some of said conductive interconnects including said stacked masses.
35. The microelectronic assembly as claimed in claim 32, wherein said conductive interconnects include stud bumps bonded to said contacts and a flowable conductive medium bonding said stud bumps to said terminals.
36. The microelectronic assembly as claimed in claim 35, wherein said flowable conductive medium includes a fusible conductive medium.
37. The microelectronic assembly as claimed in claim 36, wherein said flowable conductive medium includes a conductive adhesive.