Flexible circuit assembly without solder

• US 8,404,977 B2
• Filed: 04/27/2012
• Issued: 03/26/2013
• Est. Priority Date: 05/08/2007
• Status: Active Grant

• Current Assignee: Joseph Charles Fjelstad
• Original Assignee: Occam Portfolio LLC
• Inventors: Fjelstad, Joseph C
• Primary Examiner(s): Estrada, Angel R
• Assistant Examiner(s): LOPEZ CRUZ, DIMARY S
• Application Number:
  US13/458,167
• Publication Number:
  US 20120211265A1
• Time in Patent Office: 333 Days
• Field of Search: 174/251, 174/254, 174/260, 174/261, 257/698, 257/686
• US Class Current: 174/251
• CPC Class Codes: H01L 21/568 Temporary substrate used as encapsulation process aid H01L21/4832 and H01L21/566 take precedence
• CPC Class Codes: H01L 2224/32245 the item being metallic
• CPC Class Codes: H01L 2224/45015 being circular
• CPC Class Codes: H01L 2224/45099 Material
• CPC Class Codes: H01L 2224/48227 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/48465 the other connecting portion not on the bonding area being a wedge bond, i.e. ball-to-wedge, regular stitch
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 24/31 Structure, shape, material or disposition of the layer connectors after the connecting process
• CPC Class Codes: H01L 24/48 of an individual wire 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 2924/00012 Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• 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 2924/01013 Aluminum [Al]
• CPC Class Codes: H01L 2924/01029 Copper [Cu]
• CPC Class Codes: H01L 2924/01078 Platinum [Pt]
• CPC Class Codes: H01L 2924/01079 Gold [Au]
• CPC Class Codes: H01L 2924/12041 LED
• CPC Class Codes: H01L 2924/14 Integrated circuits
• CPC Class Codes: H01L 2924/15311 being a ball array, e.g. BGA
• CPC Class Codes: H01L 2924/181 : Encapsulation
• CPC Class Codes: H01L 2924/1815 : Shape
• CPC Class Codes: H01L 2924/207 : Diameter ranges
• CPC Class Codes: H01L 2924/3025 : Electromagnetic shielding
• CPC Class Codes: H01L 2924/3512 : Cracking
• 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 2201/09481 : Via in pad; Pad over filled via
• CPC Class Codes: H05K 2203/1316 : Moulded encapsulation of mounted components
• CPC Class Codes: H05K 2203/1469 : Circuit made after mounting or encapsulation of the components
• CPC Class Codes: H05K 3/284 : for encapsulating mounted components H05K1/185 takes precedence
• CPC Class Codes: H05K 3/32 : electrically connecting electric components or wires to printed circuits
• CPC Class Codes: Y10T 156/10 : Methods of surface bonding and/or assembly therefor
• CPC Class Codes: Y10T 156/1057 : Subsequent to assembly of laminae

Abstract

Provided is a flexible electronic assembly that uses no solder. Components or component packages are mounted on a flexible substrate. Vias connect through the substrate to the components'"'"' leads. Circuits are formed on the opposite side of the substrate interconnecting the component through the vias. The assembly is made flexible by removing encapsulent material between components.

Claims

1. A circuit assembly comprising:

a flexible substrate having a first and a second side;

at least two electrical components, each with a conductive pathway;

each electrical component located on the first side the flexible substrate and in direct physical contact with the first side;

an electrically insulating material encapsulate attached to at least one side of the component;

the encapsulate attached to the first side of the flexible substrate with no encapsulate between the at least two components and the flexible substrate;

a via extending through the flexible substrate to the conductive pathway of each component;

an extraction extending through the encapsulate to a level proximate to a first side of the flexible substrate defining gap in the encapsulate between the at least two electric components, the gap selectively permitting the flexible substrate to flex in the region of the gap;

each via having an inclusion of electrically conductive non solder material, the non solder material in electrical communication with the conductive pathway of each said at least two electrical components;

at least one trace formed on the second side of the flexible substrate interconnecting the non solder electrically conductive material of the vias of the at least two components; and

said at least one trace covered with an electrically insulating material.

2. The assembly of claim 1 wherein at least one of the electrical components is an electro-optical component.

3. The assembly of claim 2 wherein the conductive pathway is disposed to conduct signals by light.