High density stackable and flexible substrate-based devices and systems and methods of fabricating

• US 6,785,144 B1
• Filed: 08/24/2000
• Issued: 08/31/2004
• Est. Priority Date: 06/10/1999
• Status: Expired due to Term

• Current Assignee: Micron Technology, Inc.
• Original Assignee: Micron Technology, Inc.
• Inventors: Akram, Salman
• Primary Examiner(s): Vigushin, John B.
• Application Number:
  US09/645,373
• Time in Patent Office: 1,468 Days
• Field of Search: 361/749-753, 361/757, 361/807, 361/808, 361/813, 361/771, 361/803, 257/686, 257/723, 257/777, 257/778, 174/254
• US Class Current: 361/749
• CPC Class Codes: H01L 2224/0401 Bonding areas specifically adapted for bump connectors, e.g. under bump metallisation [UBM]
• CPC Class Codes: H01L 2224/16225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 23/5387 Flexible insulating substrates H01L23/5388 takes precedence
• 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 2924/01078 Platinum [Pt]
• CPC Class Codes: H01L 2924/01079 Gold [Au]
• CPC Class Codes: H01L 2924/01087 Francium [Fr]
• CPC Class Codes: H01L 2924/3011 Impedance
• CPC Class Codes: H05K 1/141 One or more single auxiliary printed circuits mounted on a main printed circuit, e.g. modules, adapters H05K1/142 and H05K1/147 take precedence
• CPC Class Codes: H05K 1/144 Stacked arrangements of planar printed circuit boards
• CPC Class Codes: H05K 1/147 at least one of the printed circuits being bent or folded, e.g. by using a flexible printed circuit H05K1/148 takes precedence
• CPC Class Codes: H05K 1/189 characterised by the use of a flexible or folded printed circuit H05K3/326 takes precedence
• CPC Class Codes: H05K 2201/10674 Flip chip
• CPC Class Codes: H05K 2201/2018 Presence of a frame in a printed circuit or printed circuit assembly

Abstract

A flexible carrier substrate assembly or module that facilitates stacking of multiple carrier substrates bearing semiconductor dice for high density electronic systems. After the dice are placed on the flexible substrate, a flexible support frame may be applied to the flexible substrate. The support frame includes conductive paths therethrough to connect to circuit traces running from the dice on the substrate to the substrate perimeter to interconnect superimposed carrier substrates. The flexible carrier substrates may be bent to a radius of any given curvature to conform to various non-planar regular and irregular surfaces. Furthermore, since the frame as well as the substrate may be flexible, multiple, flexible substrate assemblies may be stacked one on top of another wherein an upper assembly has a different radius than a lower module and any intermediate assemblies have progressively differing radii from bottom to top position.

Claims

1. A computer system comprising:

an input device;

an output device;

a microprocessor coupled to the input device and the output device; and

a flexible carrier substrate module, coupled to the microprocessor, comprising;

a flexible carrier substrate having a surface portion carrying conductive traces thereon;

at least one semiconductor device connected to the conductive traces; and

a flexible support frame attached to the flexible carrier substrate and having a plurality of conductive paths therethrough connected to the conductive traces to provide electrical coupling of the conductive traces to circuitry external to the flexible carrier substrate.

2. The computer system according to claim 1, wherein the flexible carrier substrate exhibits a first radius of curvature.

3. The computer system according to claim 1, wherein a second flexible carrier substrate is mounted to the flexible support frame.

4. The computer system according to claim 3, wherein the flexible carrier substrate exhibits a first radius of curvature and the second flexible carrier substrate exhibits a second radius of curvature.

5. The computer system according to claim 3, wherein the second flexible carrier substrate has a least one semiconductor device attached thereto.

6. The computer system according to claim 3, wherein the flexible carrier substrate is shaped in a non-planar configuration and the second flexible carrier substrate substantially conforms to a shape of the flexible carrier substrate.

7. The computer system according to claim 1, further comprising a hermetic seal around the flexible carrier substrate module.

19. The computer system of claim 7, further comprising a cover enclosing the flexible carrier substrate module.

20. The computer system of claim 19, wherein the cover includes a hermetic seal.

8. A computer system comprising:

an input device;

an output device;

a microprocessor coupled to the input device and the output device;

a rigid substrate having a first set of conductive traces formed on a surface thereof; and

a flexible carrier substrate module, coupled to the microprocessor, comprising;

at least one semiconductor device;

a first flexible carrier substrate having a first and a second end and having a surface portion carrying a second set of conductive traces thereon, wherein the first and second end of the first flexible carrier substrate are mounted to the rigid substrate such that the second set of conductive traces are electrically coupled with the first set of conductive traces and wherein the first flexible carrier substrate exhibits a first radius; and

a second flexible carrier substrate having a first and second end and having a surface portion carrying a third set of conductive traces thereon, wherein the first and second end of the second flexible carrier substrate are mounted to the rigid substrate such that the third set of conductive traces are electrically coupled with the first set of conductive traces and wherein the second flexible carrier substrate exhibits a second radius different than the first radius.

9. The computer system according to claim 8, further comprising at least one other semiconductor device attached to the rigid substrate.

10. The computer system according to claim 8, wherein the second flexible carrier substrate is superimposed over the first flexible carrier substrate.

11. The computer system according to claim 8, wherein the at least one semiconductor device includes at least a first semiconductor device attached to the first flexible carrier substrate.

12. The computer system according to claim 11, wherein the at least one semiconductor device further includes at least a second semiconductor device attached to the second flexible carrier substrate.

13. The computer system according to claim 11, wherein the rigid substrate is substantially planar.

14. The computer system according to claim 8, wherein the at least one semiconductor device includes a first semiconductor device on the surface of the second flexible carrier substrate and a second semiconductor device on a second, opposing surface of the second flexible carrier substrate.

15. The computer system according to claim 8, further comprising a cover enclosing the flexible carrier substrate module.

16. The computer system according to claim 15, wherein the cover includes a hermetic seal.

17. A computer system comprising:

an input device;

an output device;

a microprocessor coupled to the input device and the output device;

a rigid substrate; and

a flexible carrier substrate module, coupled to the microprocessor, comprising;

a first flexible carrier substrate having a first and a second end wherein the first and second ends of the first flexible carrier substrate are mounted to the rigid substrate;

a first semiconductor device mounted to the first flexible carrier substrate;

a second flexible carrier substrate having a first and a second end wherein the first and second ends of the second flexible carrier substrate are mounted to the rigid substrate such that the second flexible carrier substrate is superimposed over the first flexible carrier substrate; and

a second semiconductor device mounted to the second flexible carrier substrate.

18. The computer system of claim 17, wherein the first flexible carrier substrate further includes a first set of conductive traces, the second flexible carrier substrate includes a second set of conductive traces, and wherein the first and second set of conductive traces are electrically coupled to a third set of conductive traces formed on the rigid substrate.