Structure and method of making interconnect element having metal traces embedded in surface of dielectric

1. An interconnect element, comprising:

a single layer dielectric element having a first exposed major surface, a plurality of first recesses extending inwardly from said first major surface, and a second exposed major surface remote from said first major surface, a plurality of second recesses extending inwardly from said second major surface;

a plurality of first metal interconnect patterns embedded in said plurality of first recesses and extending in one or more directions along said first major surface; and

a plurality of second metal interconnect patterns embedded in said plurality of second recesses and extending in one or more directions along said second major surface; and

a plurality of non-hollow plated metal posts each extending through said dielectric element between at least one of said plurality of first metal interconnect patterns and at least one of said plurality of second metal interconnect patterns.

2. The interconnect element as claimed in claim 1 , wherein said plurality of first metal interconnect patterns have outer surfaces substantially co-planar with said first major surface.

3. The interconnect element as claimed in claim 1 , wherein said plurality of second metal interconnect patterns have outer surfaces substantially co-planar with said second major surface.

4. The interconnect element as claimed in claim 1 , wherein said dielectric element includes one or more thermoplastic resins.

5. The interconnect element as claimed in claim 1 , wherein said dielectric element includes at least one resin selected from the group consisting of PEEK (polyether ether ketone), PES (polyethersulfone), PPS (polyphenylene sulfide), PEN (polyethylene napthalate), a PEEK-PES polymer blend, and liquid crystal polymers.

6. The interconnect element as claimed in claim 1 , wherein a thickness of each of said plurality of first metal interconnect patterns is at least 10 microns.

7. The interconnect element as claimed in claim 1 , wherein a thickness of each of said plurality of second metal interconnect patterns is at least 10 microns.

8. The interconnect element as claimed in claim 1 , wherein each of said plurality of plated metal posts includes copper.

9. The interconnect element as claimed in claim 1 , wherein each of said plurality of plated metal posts includes high purity copper.

10. The interconnect element as claimed in claim 1 , wherein a length of each of said plurality of plated metal posts is at most 150 microns.

11. The interconnect element as claimed in claim 1 , wherein at least some of said plurality of first metal interconnect patterns are traces exposed at the first major surface of said dielectric element.

12. The interconnect element as claimed in claim 1 , wherein at least some of said plurality of first metal interconnect patterns are contacts exposed at the first major surface of said dielectric element.

13. The interconnect element as claimed in claim 1 , wherein at least some of said plurality of second metal interconnect patterns are traces exposed at the first major surface of said dielectric element.

14. The interconnect element as claimed in claim 1 , wherein at least some of said plurality of second metal interconnect patterns are contacts exposed at the second major surface of said dielectric element.

15. The interconnect element as claimed in claim 1 , wherein said plurality of first metal interconnect patterns are coated with a bond metal layer.

16. The interconnect element as claimed in claim 15 , wherein said bond metal layer includes gold.

17. The interconnect element as claimed in claim 1 , wherein said plurality of second metal interconnect patterns are coated with a bond metal layer.

18. The interconnect element as claimed in claim 17 , wherein said bond metal layer includes gold.

19. The interconnect element as claimed in claim 1 , wherein said interconnect element is suitable for heating to a temperature of between 150 and 350° C.

20. The interconnect element as claimed in claim 1 , wherein said interconnect element is suitable for exposure to a pressure between 20 and 100 kg/cm 2 .

21. The interconnect element as claimed in claim 1 , wherein said plurality of non-hollow plated metal posts are joined to said at least some first metal interconnect patterns.

22. The interconnect element as claimed in claim 1 , wherein said plurality of non-hollow plated metal posts are joined using one or more of heat and pressure to said at least some first metal interconnect patterns.

23. The interconnect element as claimed in claim 1 , wherein contact areas are defined wherever ends of said non-hollow plated metal posts contact said at least some first metal interconnect patterns, and at each such contact area, the first metal interconnect pattern in which that contact area is defined has its edges outside of the contact area.

24. The interconnect element as claimed in claim 1 , wherein contact areas are defined wherever ends of said non-hollow plated metal posts contact said at least some second metal interconnect patterns, and at each such contact area, the second metal interconnect pattern in which that contact area is defined has its edges outside of the contact area.

25. The interconnect element as claimed in claim 1 , wherein the plurality of first metal interconnect patterns have inner surfaces which contact bottom surfaces of the plurality of first recesses, the plurality of second metal interconnect patterns have inner surfaces which contact bottom surfaces of the plurality of second recesses, and the plurality of non-hollow plated metal posts each extend through the dielectric element between the inner surface of the at least one of the plurality of first metal interconnect patterns and the inner surface of the at least one of the plurality of second metal interconnect patterns.