Methods and apparatus for three-dimensional microfabricated arrays
In exemplary implementations of this invention, electrical connections are fabricated between two orthogonal surfaces by electroplating. The two surfaces are separated (except for the electrical connections) by a gap of not more than 100 micrometers. Multiple electrical connections may be fabricated across the gap. In preparatory steps, conductive pads on the two surfaces may be separately electroplated to build up “bumps” that make it easier to bridge the remainder of the gap in a final plating step. Alternately, electroless deposition may be used instead of electroplating. In exemplary implementations, a 3D probe array may be assembled by inserting array structures into an orthogonal base plate. The array structures may be aligned and held in place, relative to the base plate, by mechanical means, including side hooks, stabilizers, bottom hooks, alignment parts and a back plate.
1. A method comprising fabrication of at least one electrical connection between a first surface and a second surface by electrical deposition, wherein:
(a) the first and second surfaces are separated, except for the at least one electrical connection, by a gap of not more than 100 micrometers;
(b) the first and second surfaces are off angle with respect to each other;
(c) the first surface is on a first plate and the second surface is on an array structure;
(d) the array structure comprises a set of elongated probes;
(e) the first plate has first plate holes; and
(f) the array structure includes a male portion that is inserted into one of the first plate holes.
2. The method of claim 1 , wherein the electrical deposition comprises electroplating.
3. The method of claim 1 , wherein the electrical deposition comprises electroless deposition.
4. The method of claim 1 , wherein the at least one electrical connection comprises multiple electrical connections, and the pitch between at least some of the multiple electrical connections is less than 50 micrometers.
5. The method of claim 4 , wherein the pitch between at least some of the multiple electrical connections is less than 40 micrometers.
6. The method of claim 5 , wherein the pitch between at least some of the multiple electrical connections is less than 30 micrometers.
7. The method of claim 1 , wherein the method further comprises making a bump on the first surface, a bump on the second surface or a bump on both the first and second surfaces, respectively, by electrical deposition while the first and second surfaces are separated by a distance of more than 100 micrometers and before making the at least one electrical connection across the gap.
8. Apparatus that includes one or more electrical connections,
wherein:
(a) each of the one or more electrical connections, respectively, is a product of electrical deposition and joins a first surface and a second surface;
(b) the first and second surfaces are off angle with respect to each other and are separated, except for the one or more electrical connections, by a gap of not more than 100 micrometers;
(c) the apparatus further comprises array structures and a first plate;
(d) each of the array structures, respectively, comprises a set of elongated probes;
(e) for at least some of the one or more electrical connections, respectively, the first surface is on the first plate and the second surface is on one of the array structures;
(f) the first plate has first plate holes; and
(g) each of the array structures, respectively, includes a male portion that is inserted into one of the first plate holes.
9. The apparatus of claim 8 , wherein the electrical deposition comprises electroplating.
10. The apparatus of claim 8 , wherein the electrical deposition comprises electroless deposition.
11. The apparatus of claim 8 , wherein the one or more electrical connections comprise multiple electrical connections, and the pitch between at least some of the multiple electrical connections is less than 50 micrometers.
12. The apparatus of claim 8 , wherein each respective male portion, out of at least some of the male portions, is fastened to the first plate by at least one fastener, the at least one fastener being configured to allow insertion of the respective male portion into, and to restrain removal of the respective male portion from, a first plate hole.
13. The apparatus of claim 12 , wherein the at least one fastener comprises one or more hooks.
14. The apparatus of claim 12 , wherein the at least one fastener is configured to snap, after the insertion, into a position that restrains the removal.
15. The apparatus of claim 8 , wherein:
each respective male portion has at least one stabilization hole;
the apparatus further comprises a stabilization device, which stabilization device includes prongs;
each of the prongs, respectively, is inserted through stabilization holes in more than one of the male portions; and
each respective prong out of at least some of the prongs includes a hook that allows insertion of the respective prong into stabilization holes and restrains removal of the respective prong from stabilization holes.
16. The apparatus of claim 15 , wherein:
the apparatus further comprises a second plate;
the second plate has holes; and
part of each of the array structures, respectively, is inserted into a hole in the second plate.
17. The apparatus of claim 8 , wherein:
the apparatus further comprises a first alignment part and a second alignment part;
the first and second alignment parts each have multiple V-shaped slots;
each of the V-shaped slots, respectively, is in contact with and compresses an array structure;
the first and second alignment parts each include fasteners; and
the fasteners allow the first and second alignment parts to move closer to each other and restrain the first and second alignment parts from moving apart from each other.
18. The apparatus of claim 8 , wherein the electrical deposition comprises electroplating.
19. The apparatus of claim 8 , wherein the electrical deposition comprises electroless deposition.