Flexible circuit assemblies without solder and methods for their manufacture
The present invention provides an electronic assembly 400 and a method for its manufacture 800, 900, 1000 1200, 1400, 1500 , and 1700 . The assembly 400 uses no solder. Components 406 or component packages 402, 802, 804, 806 with I/O leads 412 are placed 800 onto a planar substrate 808 . The assembly is encapsulated 900 with electrically insulating material 908 with vias 420, 1002 formed or drilled 1000 through the substrate 808 to the components' leads 412 . Then the assembly is plated 1200 and the encapsulation and drilling process 1500 repeated to build up desired layers 422, 1502, 1702 . The planar substrate 808 may be a flexible substrate 2016 allowing bending of an assembly 2000 to fit into various enclosures.
1. A process for producing a circuit assembly 2000 comprising executing the following steps in any order:
locating an electrical component 2102 , 2002 , 2104 , with a conductive pathway 2012 , on a flexible substrate 2016 , the conductive pathway 2012 in contact with the flexible substrate 2016 ;
attaching an electrically insulating material encapsulant 2004 to at least one side of the component 2102 , 2002 , 2104 ;
attaching the encapsulant 2004 to the flexible substrate 2016 ;
forming a via 2020 extending through the flexible substrate 2016 to a putative location of the conductive pathway 2012 ; and
extracting the encapsulant 2004 to a level proximate to a surface of the flexible substrate 2016 .
2. The process of claim 1 wherein the extracting the encapsulant 2004 forms a taper 2706 .
3. The process of claim 1 further comprising forming a trace 2404 on flexible substrate 2016 wherein the trace 2404 comprises electrically conductive material and the trace 2404 is in electrical communication with electrically conductive material 2402 , the material 2402 forming an inclusion in the via 2020 and the material 2402 in electrical communication with the pathway 2012 .
4. The process of claim 3 further comprising placing flexible electrically insulating material 2502 on the flexible substrate 2016 wherein the material 2502 covers the trace 2404 , the material 2402 , the via 2020 , and the pathway 2012 .
5. The process of claim 4 wherein the assembly 2000 is flexed at a point on the level proximate to a surface of the flexible substrate 2016 .
6. The process of claim 1 wherein the component is pre-tested and burned in prior to locating the component on the flexible substrate 2016 .
7. A process for producing a circuit assembly 2900 comprising executing the following steps:
attaching an electrically insulating material flexible encapsulant 2004 a to at least one side of an electrical component wherein a conductive pathway of the component is exposed;
extracting the encapsulant 2004 a proximate to the component to a level that permits flexing the assembly 2900 ; and
forming a trace on flexible encapsulant 2004 a wherein the trace comprises an electrically conductive material and the trace is in electrical communication with the pathway.
8. The process of claim 7 further comprising placing flexible electrically insulating material 2502 a on the flexible encapsulant 2004 a wherein the material 2502 a covers the trace and the pathway.
9. The process of claim 7 further comprising flexing the assembly 2900 at a point on the level that permits flexing the assembly 2900 .
10. The process of claim 9 further comprising flexing the assembly 2900 at a point on the level that permits flexing the assembly 2900 .
11. The process of claim 7 wherein the component is pre-tested and burned in prior to the encapsulant 2004 a being attached to at least one side of the component.
12. A product produced by the process of claim 7 .