Flexible interface structures for electronic devices

• US 5,938,452 A
• Filed: 09/02/1997
• Issued: 08/17/1999
• Est. Priority Date: 12/23/1996
• Status: Expired due to Term

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Wojnarowski, Robert John
• Primary Examiner(s): Jones, Deborah
• Assistant Examiner(s): LAM, CATHY FONG FONG
• Application Number:
  US08/922,018
• Time in Patent Office: 714 Days
• Field of Search: 428/209, 428/901, 439/66, 439/67, 439/91, 174/254
• US Class Current: 439/67
• CPC Class Codes: H01L 21/4853 Connection or disconnection of other leads to or from a metallisation, e.g. pins, wires, bumps
• 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 23/49811 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 24/02 Bonding areas on insulating substrates, e.g. chip carriers, H01L23/49816, H01L23/49838, H01L23/5389; Manufacturing methods related thereto
• CPC Class Codes: H01L 24/16 of an individual bump connector
• 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 2924/01004 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 2924/01014 Silicon [Si]
• CPC Class Codes: H01L 2924/01021 Scandium [Sc]
• CPC Class Codes: H01L 2924/01022 Titanium [Ti]
• CPC Class Codes: H01L 2924/01027 Cobalt [Co]
• CPC Class Codes: H01L 2924/01028 Nickel [Ni]
• CPC Class Codes: H01L 2924/01029 Copper [Cu]
• CPC Class Codes: H01L 2924/01033 Arsenic [As]
• 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 2924/0105 : Tin [Sn]
• 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 2924/014 : Solder alloys
• CPC Class Codes: H01L 2924/12042 : LASER
• CPC Class Codes: H01L 2924/19041 : being a capacitor
• CPC Class Codes: H01L 2924/19043 : being a resistor
• CPC Class Codes: H01L 2924/30107 : Inductance
• CPC Class Codes: H01L 2924/3511 : Warping
• CPC Class Codes: H05K 2201/0373 : Conductors having a fine structure, e.g. providing a plurality of contact points with a structured tool
• CPC Class Codes: H05K 2201/10257 : Hollow pieces of metal, e.g. used in connection between component and PCB
• CPC Class Codes: H05K 2201/10378 : Interposers
• CPC Class Codes: H05K 3/326 : the printed circuit having integral resilient or deformable parts, e.g. tabs or parts of flexible circuits H05K3/365 takes precedence
• CPC Class Codes: H05K 3/3436 : having an array of bottom contacts, e.g. pad grid array or ball grid array components
• CPC Class Codes: H05K 3/4092 : Integral conductive tabs, i.e. conductive parts partly detached from the substrate
• CPC Class Codes: Y02P 70/50 : Manufacturing or production processes characterised by the final manufactured product
• CPC Class Codes: Y10S 428/901 : Printed circuit
• CPC Class Codes: Y10T 29/49124 : On flat or curved insulated base, e.g., printed circuit, etc.
• CPC Class Codes: Y10T 29/4913 : Assembling to base an electrical component, e.g., capacitor, etc.
• CPC Class Codes: Y10T 428/24917 : including metal layer

Abstract

A flexible film interface includes a flexible film; flexible material attached to a portion of the flexible film; surface metallization on the flexible material, the flexible film having at least one via extending therethrough to the surface metallization; and a floating pad structure including floating pad metallization patterned over the flexible material and the surface metallization, a first portion of the floating pad metallization forming a central pad and a second portion of the floating pad metallization forming at least one extension from the central pad and extending into the at least one via.

Claims

1. A flexible film interface comprising:

a flexible film;

flexible material attached to the flexible film;

surface metallization on the flexible material;

the flexible film having at least one via extending therethrough to the surface metallization;

a floating pad structure comprising floating pad metallization patterned over the flexible film opposite the flexible material and the surface metallization, a first portion of the floating pad metallization forming a central pad and a second portion of the floating pad metallization forming at least one extension from the central pad and extending into the at least one via, the floating pad structure capable of accommodating thermal and material stresses and permitting movements of the central pad independent of the surface metallization.

2. The interface of claim 1 wherein the floating pad metallization includes at least two extensions from the central pad and wherein the flexible film has at least two vias therein, each extension extending into a respective via.

3. The interface of claim 2 wherein portions of the surface metallization are in contact with the flexible film and comprise film portions of the surface metallization, and wherein the at least two vias extend to the film portions of the surface metallization.

4. The interface of claim 3 wherein the flexible material comprises a low modulus polymer.

5. The interface of claim 4 wherein the flexible material has tapered edges.

6. The interface of claim 3 further including a solder mask extending over the at least two extensions.

7. The interface of claim 3 further including a conductive material attached to the surface metallization, the conductive material comprising a solder ball or a conductive polymer.

8. An electronic package comprising:

(a) a flexible film interface including;

a flexible film;

flexible material attached to the flexible film;

surface metallization on the flexible material and on a same side of the flexible film as the flexible material, the flexible film having at least two vias extending therethrough to the surface metallization situated on the flexible film; and

a floating pad structure comprising floating pad metallization patterned over the flexible film opposite the flexible material and the surface metallization, a first portion of the floating pad metallization forming a central pad and a second portion of the floating pad metallization forming at least two extensions from the central pad and extending into the at least two vias, the floating pad structure capable of accommodating thermal and material stresses and permitting movements of the central pad independent of the surface metallization;

(b) a base member having a at least one conductive base pad; and

(c) a conductive material coupling the surface metallization and the at least one base pad.

9. The package of claim 8 wherein the conductive material is a solder ball or a conductive polymer.

10. The package of claim 9 wherein the base member is a printed circuit board, a multi-chip module, a semiconductor wafer, a chip, a passive component, or a flexible interconnect layer structure.

11. The package of claim 9 further including a mount member having at least one conductive mount pad and a second conductive material coupling the central pad of the floating pad structure and the at least one mount pad.

12. The package of claim 11 wherein the mount member comprises a flip chip or a ball grid array.

13. A flexible film interface comprising:

a flexible film;

surface metallization attached to a portion of the flexible film;

the flexible film having at least one via extending therethrough to the surface metallization;

a floating pad structure comprising floating pad metallization patterned over the flexible film opposite the surface metallization, a first portion of the floating pad metallization forming a central pad and a second portion of the floating pad metallization forming at least one extension from the central pad and extending into the at least one via, the floating pad structure capable of accommodating thermal and material stresses and permitting movements of the central pad independent of the surface metallization.