Method of making an electronic assembly having a flexible circuit wrapped around a substrate

• US 5,362,656 A
• Filed: 04/15/1994
• Issued: 11/08/1994
• Est. Priority Date: 12/02/1992
• Status: Expired due to Fees

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: McMahon, John F.
• Primary Examiner(s): Chaudhuri, Olik
• Assistant Examiner(s): Pham, Long
• Application Number:
  US08/228,095
• Time in Patent Office: 207 Days
• Field of Search: 174/254, 174/255, 174/52.4, 174/261, 257/688, 257/692-700, 257/758-760, 257/672, 257/673, 257/676, 257/684, 257/685, 257/686, 361/749, 361/761, 439/67, 439/77, 29/827, 228/180.21, 228/180.22, 228/180.50, 437/205, 437/208, 437/209, 437/212, 437/220, 437/206, 437/207, 437/915
• US Class Current: 29/827
• CPC Class Codes: H01L 2224/45099 Material
• CPC Class Codes: H01L 2224/49109 outside the semiconductor or solid-state body
• CPC Class Codes: H01L 23/49534 Multi-layer
• CPC Class Codes: H01L 23/49572 consisting of thin flexible metallic tape with or without a film carrier H01L23/49503 - H01L23/49568 and H01L23/49575 - H01L23/49579 take precedence
• CPC Class Codes: H01L 24/49 of a plurality of wire connectors
• CPC Class Codes: H01L 24/50 Tape automated bonding [TAB] connectors, i.e. film carriers; Manufacturing methods related thereto thin flexible metallic tape with or without a film carrier H01L23/49572, flexible insulating substrates H01L23/4985, H01L23/5387
• CPC Class Codes: H01L 24/86 using tape automated bonding [TAB]
• 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 2924/01005 Boron [B]
• CPC Class Codes: H01L 2924/01006 Carbon [C]
• CPC Class Codes: H01L 2924/01029 Copper [Cu]
• CPC Class Codes: H01L 2924/01033 Arsenic [As]
• CPC Class Codes: H01L 2924/01082 Lead [Pb]
• CPC Class Codes: H01L 2924/01088 Radium [Ra]
• CPC Class Codes: H01L 2924/14 Integrated circuits
• CPC Class Codes: H01L 2924/15153 the die mounting substrate comprising a recess for hosting the device
• CPC Class Codes: H01L 2924/15165 Monolayer substrate
• CPC Class Codes: H01L 2924/15311 being a ball array, e.g. BGA
• CPC Class Codes: H01L 2924/15747 Copper [Cu] as principal constituent
• CPC Class Codes: H01L 2924/30107 : Inductance
• CPC Class Codes: H01L 2924/3011 : Impedance
• CPC Class Codes: Y10T 29/49121 : Beam lead frame or beam lead device
• CPC Class Codes: Y10T 29/49128 : Assembling formed circuit to base

Abstract

An electronic package assembly that includes a flexible circuit wrapped around a metal substrate. The leads of the flexible circuit are connected to an integrated circuit that is mounted to the top surface of the substrate. The flexible circuit has a plurality of metal pads located adjacent to the bottom surface of the substrate. The flexible circuit also contains a power/ground plane and a number of conductive signal lines that couple the integrated circuit to the metal pads. The pads can be soldered to a printed circuit board to electrically couple the integrated circuit to the board.

Claims

1. A method of constructing an electronic assembly, comprising the steps of:

a) providing a substrate that has a top surface and a bottom surface;

b) mounting an electrical device to said top surface of said substrate;

c) attaching leads of a flexible circuit to said electrical device, said flexible circuit having a metal pad;

d) wrapping said flexible circuit around said substrate such that said metal pad is adjacent to said bottom surface of said substrate; and

,

e) bonding said flexible circuit to said substrate.

2. The method as recited in claim 1, wherein said flexible circuit is wrapped around said substrate before said leads are attached to said electrical device.

3. The method as recited in claim 1, further comprising the step of encapsulating said electrical device with a dielectric material.

4. The method as recited in claim 1, further comprising the step of bonding a portion of said flexible circuit to said top surface of said substrate before said flexible circuit is wrapped around said substrate.

5. A method of constructing an electronic assembly, comprising the steps of:

a) providing a substrate that has a top surface and a bottom surface;

b) mounting an electrical device to said top surface of said substrate;

c) attaching leads of a flexible circuit to said electrical device, said flexible circuit having a hole that provides access to a conductive line that extends from said lead;

d) wrapping said flexible circuit around said substrate such that said hole is adjacent to said bottom surface of said substrate;

e) bonding said flexible circuit to said substrate;

f) placing a solder preform into said hole of said flexible circuit;

g) heating said solder preform until said solder attains a liquid form; and

,

h) cooling said solder until said solder attains a solid form.

6. The method as recited in claim 5, wherein said flexible circuit is wrapped around said substrate before said leads are attached to said electrical device.

7. The method as recited in claim 5, further comprising the step of encapsulating said electrical device with a dielectric material.

8. The method as recited in claim 5, further comprising the step of bonding a portion of said flexible circuit to said top surface of said substrate before said flexible circuit is wrapped around said substrate.