Microelectronic assemblies with multiple leads

• US 6,104,087 A
• Filed: 08/24/1998
• Issued: 08/15/2000
• Est. Priority Date: 07/07/1994
• Status: Expired due to Term

• Current Assignee: Tessera, Inc. (Adeia Inc.)
• Original Assignee: Tessera, Inc. (Adeia Inc.)
• Inventors: Smith, John W., DiStefano, Thomas H.
• Primary Examiner(s): Hardy, David
• Assistant Examiner(s): CLARK, JASMINE JHIHAN B
• Application Number:
  US09/138,858
• Time in Patent Office: 722 Days
• Field of Search: 257/693, 257/696, 257/690-692
• US Class Current: 257/696
• CPC Class Codes: H01L 21/4839 Assembly of a flat lead with an insulating support, e.g. for TAB
• CPC Class Codes: H01L 2224/16 of an individual bump connector
• CPC Class Codes: H01L 2224/45124 Aluminium (Al) as principal constituent
• CPC Class Codes: H01L 2224/48 of an individual wire connector
• CPC Class Codes: H01L 2224/73253 Bump and layer connectors
• CPC Class Codes: H01L 23/22 liquid at the normal operating temperature of the device
• CPC Class Codes: H01L 23/49811 Additional leads joined to the metallisation on the insulating substrate, e.g. pins, bumps, wires, flat leads H01L23/49827 takes precedence
• CPC Class Codes: H01L 23/49816 Spherical bumps on the substrate for external connection, e.g. ball grid arrays [BGA]
• CPC Class Codes: H01L 23/49827 Via connections through the substrates, e.g. pins going through the substrate, coaxial cables H01L23/49822, H01L23/49833, H01L23/4985, H01L23/49861 take precedence
• CPC Class Codes: H01L 23/4985 Flexible insulating substrates H01L23/49572 and H01L23/49855 take precedence
• CPC Class Codes: H01L 23/642 Capacitive arrangements H01L23/49589, H01L23/645, H01L23/647, H01L23/66 take precedence; capacitive effects between wiring layers on the semiconductor body H01L23/5222
• CPC Class Codes: H01L 24/72 Detachable connecting means consisting of mechanical auxiliary parts connecting the device, e.g. pressure contacts using springs or clips
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/01004 Beryllium [Be]
• CPC Class Codes: H01L 2924/01005 Boron [B]
• CPC Class Codes: H01L 2924/01006 Carbon [C]
• CPC Class Codes: H01L 2924/01013 Aluminum [Al]
• CPC Class Codes: H01L 2924/01023 Vanadium [V]
• CPC Class Codes: H01L 2924/01027 Cobalt [Co]
• CPC Class Codes: H01L 2924/01029 : Copper [Cu]
• CPC Class Codes: H01L 2924/01032 : Germanium [Ge]
• CPC Class Codes: H01L 2924/01033 : Arsenic [As]
• CPC Class Codes: H01L 2924/01039 : Yttrium [Y]
• CPC Class Codes: H01L 2924/01042 : Molybdenum [Mo]
• CPC Class Codes: H01L 2924/01046 : Palladium [Pd]
• CPC Class Codes: H01L 2924/01047 : Silver [Ag]
• CPC Class Codes: H01L 2924/01066 : Dysprosium [Dy]
• CPC Class Codes: H01L 2924/01074 : Tungsten [W]
• CPC Class Codes: H01L 2924/01078 : Platinum [Pt]
• CPC Class Codes: H01L 2924/01079 : Gold [Au]
• CPC Class Codes: H01L 2924/01082 : Lead [Pb]
• CPC Class Codes: H01L 2924/01322 : Eutectic Alloys, i.e. obtained by a liquid transforming into two solid phases
• CPC Class Codes: H01L 2924/07802 : not being an ohmic electrical conductor
• CPC Class Codes: H01L 2924/10253 : Silicon [Si]
• CPC Class Codes: H01L 2924/12042 : LASER
• CPC Class Codes: H01L 2924/14 : Integrated circuits
• CPC Class Codes: H01L 2924/15174 : in different layers of the multilayer substrate
• CPC Class Codes: H01L 2924/15311 : being a ball array, e.g. BGA
• CPC Class Codes: H01L 2924/16152 : Cap comprising a cavity for hosting the device, e.g. U-shaped cap
• CPC Class Codes: H01L 2924/19041 : being a capacitor
• CPC Class Codes: H01L 2924/19043 : being a resistor
• CPC Class Codes: H01L 2924/3025 : Electromagnetic shielding
• CPC Class Codes: H01L 2924/351 : Thermal stress
• CPC Class Codes: H05K 1/118 : specially for flexible printed circuits, e.g. using folded portions
• CPC Class Codes: H05K 2201/0133 : Elastomeric or compliant polymer elastomeric conductor H05K2201/0314
• CPC Class Codes: H05K 2201/0394 : Conductor crossing over a hole in the substrate or a gap between two separate substrate parts
• CPC Class Codes: H05K 2201/0397 : Tab forming integral conductive tabs H05K3/4092
• CPC Class Codes: H05K 2201/09081 : Tongue or tail integrated in planar structure, e.g. obtained by cutting from the planar structure
• CPC Class Codes: H05K 2201/091 : Locally and permanently deformed areas including dielectric material
• CPC Class Codes: H05K 2203/063 : of preperforated insulating layer
• CPC Class Codes: H05K 3/361 : Assembling flexible printed circuits with other printed circuits
• CPC Class Codes: H05K 3/4084 : by deforming at least one of the conductive layers
• CPC Class Codes: Y10T 29/49126 : Assembling bases
• CPC Class Codes: Y10T 29/49144 : by metal fusion
• CPC Class Codes: Y10T 29/49158 : with molding of insulated base

Abstract

A microelectronic connection component includes a dielectric sheet having an area array of elongated, strip-like leads. Each lead has a terminal end fastened to the sheet and a tip end detachable from the sheet. Each lead extends horizontally parallel to the sheet, from its terminal end to its tip end. The tip ends are attached to a second element, such as another dielectric sheet or a semiconductor wafer. The first and second elements are then moved relative to one another to advance the tip end of each lead vertically away from the dielectric sheet and deform the leads into a bent, vertically extensive configuration. The preferred structures provide semiconductor chip assemblies with a planar area array of contacts on the chip, an array of terminals on the sheet positioned so that each terminal is substantially over the corresponding contact, and an array of metal S-shaped ribbons connected between the terminals and contacts. A compliant dielectric material may be provided between the sheet and chip, substantially surrounding the S-shaped ribbons.

Claims

1. A packaged semiconductor chip comprising:

(a) a semiconductor chip having a front surface with an area array of contacts thereon;

(b) a connector body having a bottom surface facing toward said front surface of said chip but spaced therefrom and having a top surface facing away from said chip, said connector body having an area array of terminal structures exposed on said bottom surface and overlying the array of contacts on said chip, said connector body having terminals electrically connected to said terminal structures and exposed for connection to an external circuit panel overlying the top surface; and

(c) flexible leads extending between said terminal structures and said contacts, each said lead having a terminal end attached to one said terminal structure and a tip end attached to one said contacts, said connector body extending over said tip ends of said leads and said contacts.

2. An assembly as claimed in claim 1 wherein each said flexible lead is constituted by a metallic ribbon having oppositely-directed major surfaces, the ribbon being curved in directions normal to its major surfaces.

3. A package semiconductor chip as claimed in claim 1 further comprising a compliant dielectric material substantially filling the space between said front surface of said microelectronic element and said bottom surface of said connector body.

4. A package semiconductor chip as claimed in claim 1 wherein said connector body includes conductors interconnecting at least some of said terminals and leads with one another.

5. A packaged semiconductor chip as claimed in claim 1 wherein said terminals overlie said semiconductor chip.

6. A packaged semiconductor chip as claimed in claim 1 wherein said connector body top surface has an area substantially equal to the area of said front surface of said chip.

7. A package semiconductor chip claimed in claim 2 wherein said ribbons are formed integrally with said terminal structures.

9. A package semiconductor chip as claimed in claim 2 wherein said contacts are spaced apart from one another in said array at a contact pitch of about 1.25 mm or less.

10. A package semiconductor chip as claimed in claim 2 wherein each of said leads is generally S-shaped.

11. A package semiconductor chip as claimed in claim 4 further comprising a second semiconductor chip, said terminals, leads and conductors interconnecting said second semiconductor chip with the first-said semiconductor chip with one another so that said connector body and said chips constitute a multichip module.

12. A package semiconductor chip as claimed in claim 9 wherein said metallic ribbons are less than about 30 microns thick between said major surfaces.

13. A package semiconductor chip as claimed in claim 12 wherein said metallic ribbons consist essentially of gold.

14. A package semiconductor chip as claimed in claim 3 wherein said connector body is a flexible, sheetlike element.

15. A package semiconductor chip as claimed in claim 14 wherein said terminal structures extend through said sheetlike element from said bottom surface to said top surface, and wherein said terminal structures define said exposed terminals.

16. A package semiconductor chip as claimed in claim 4 wherein said bottom surface of said connector body is substantially free of perforations other than at said terminal structures.

8. A package semiconductor chip as claimed in 2 wherein all of said leads are substantially parallel to one another.

17. A microelectronic connector comprising:

(a) a body having a bottom surface;

(b) an area array of terminal structures mounted to said body and exposed on said bottom surface;

(c) a plurality of generally S-shaped leads, each said lead extending away from said bottom surface, each said S-shaped lead having a terminal end connected to one said terminal structure and a tip end remote from the terminal structure; and

(d) a layer of a compliant dielectric material on said bottom surface of said body, said compliant layer having a bottom surface remote from said body, said compliant layer substantially surrounding and supporting said S-shaped leads, said tip ends of said S-shaped leads protruding from said bottom surface of said compliant layer, whereby said tip ends of said leads can be engaged with contacts on a microelectronic element by juxtaposing the contact-bearing surface of the microelectronic element with the bottom surface of the compliant layer.

18. A connector as claimed in claim 17 wherein each said lead has an electrically conductive bonding material at its tip end for joining the tip end to a contact.

19. A connector as claimed in claim 18 wherein each said lead is formed from a metallic ribbon having oppositely-directed major surfaces, the ribbon being curved in directions normal to its major surfaces to form the S-shape.

20. A connector as claimed in claim 19 wherein each said ribbon consists essentially of gold and wherein each said ribbon is between about 5 microns and 25 microns thick and between about 200 and about 1000 microns long.

21. A connector as claimed in claim 19 wherein each said ribbon consists essentially of copper and wherein each said ribbon is between about 10 microns and 35 microns thick and between about 500 and about 2500 microns long.

22. A microelectronic connector comprising:

(a) a body having a bottom surface;

(b) an area array of terminal structures mounted to said body and exposed on said bottom surface;

(c) a plurality of curved flexible leads, each said lead extending away from said bottom surface, wherein each said lead is formed from a metallic ribbon having oppositely-directed major surfaces, the ribbon being curved in directions normal to its major surfaces each said lead having a terminal end connected to one said terminal structure and a tip end remote from the terminal structure; and

(d) a layer of a compliant dielectric material on said bottom surface of said body, said compliant layer having a bottom surface remote from said body, said compliant layer substantially surrounding and supporting said leads, said tip ends of said leads protruding from said bottom surface of said compliant layer, whereby said tip ends of said leads can be engaged with contacts on a microelectronic element by juxtaposing the contact-bearing surface of the microelectronic element with the bottom surface of the compliant layer.

23. A connector as claimed in claim 22 wherein each said lead has an electrically conductive bonding material at its tip end for joining the tip end to a contact.

24. A connector as claimed in claim 22 wherein said connector body has a top surface facing away from said microelectronic element, and has terminals exposed to said top surface electrically connected to said terminal structures on said bottom surface, whereby said terminals exposed to said top surface are connected to said leads.

25. A connector as claimed in claim 23 wherein each said ribbon consists essentially of gold and wherein each said ribbon is between about 5 microns and 25 microns thick and between about 200 and about 1000 microns long.

26. A connector as claimed in claim 23 wherein each said ribbon consists essentially of copper and wherein each said ribbon is between about 10 microns and 35 microns thick and between about 500 and about 2500 microns long.

27. A connector as claimed in claim 24 wherein said connector body is a flexible sheetlike element.

28. A connector as claimed in claim 27 further comprising a flexible dielectric positioner sheet overlying said bottom surface of said compliant layer, said tip ends of said leads including electrically conductive tip end structures extending through said positioner sheet and connected to said tip ends of said leads.

29. The assembly of claim 28 wherein said positioner sheet has an adhesive or a bottom surface facing away from said body.