Vertical soldering technology for 3D circuit assembly
AssigneeThe United States of Americas as represented by the Secretary of the Army
InventorsStephen Redington, Christopher Macrae, Matthew Sargent
Life of this patent
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Abstract
A circuit assembly with an electrical connection between two individual Printed Circuit Boards (PCBs) or Circuit Card Assemblies (CCAs) that are vertically stacked with a connection formed entirely of solder and with a gap in between surfaces that components may occupy. Coalescing solder paste merges between the surfaces when it is in a liquid state to form a solder bridge. The resultant assembly can be encapsulated to form a solid monolithic electronic assembly to improve robustness and allow the assembly to better withstand compressive forces.
Claims22
A method for assembling printed circuit board assemblies comprising the steps of:
- on a top surface and a bottom surface to be joined, depositing wet solder paste on a copper land pattern such that an overprint of wet solder paste extends beyond the copper land pattern;
- positioning a spacer between the top surface and the bottom surface, said spacer having a width equal to the desired inter-board gap;
- stacking the top surface and the bottom surface such that the deposited wet solder paste on each is aligned;
- and
- forming a solder joint between the top surface and the bottom surface by merging the wet solder paste on the top surface with the wet solder paste on the bottom surface via a reflow operation.
A method for assembling printed circuit board assemblies comprising the steps of:
- on a top surface and a bottom surface to be joined, depositing wet solder paste on a cylindrical copper land pattern such that an overprint of wet solder paste extends beyond the cylindrical copper land pattern and wherein
- the copper land pattern has a diameter magnitude twice as large as a desired inter-board gap and a diameter of the wet solder paste deposited on the cylindrical copper land is larger than the diameter of the copper land pattern such that a resultant height of solder paste after a reflow operation is taller than a height of the wet solder paste;
- positioning a spacer between the top surface and the bottom surface, said spacer having a width equal to a desired inter-board gap;
- stacking the top surface and the bottom surface such that the deposited wet solder paste on each is aligned;
- and
- forming a solder joint between the top surface and the bottom surface by merging the wet solder paste on the top surface with the wet solder paste on the bottom surface via a reflow operation.
A method for assembling printed circuit board assemblies comprising the steps of:
- on a top surface to be joined, depositing wet solder paste on a copper land pattern;
- placing a component with a plurality of terminations on the deposited wet solder paste;
- depositing wet solder paste on a top most termination of the component;
- placing a bottom surface to be joined such that the deposited wet solder paste is aligned to a matching copper land pattern on the bottom surface;
- and
- forming a solder joint between the top surface and the bottom surface by merging the component with wet solder paste deposited on the termination on the top surface with the bottom surface via a reflow operation.
Dependencies are inferred from the claim text.