Underlying recessed component placement
AssigneeAlcatel-Lucent Canada Inc.
InventorsAlex L. CHAN, Paul J. BROWN
Life of this patent
Estimating the term…
Abstract
An underlying recess is provided for component placement beneath Ball Grid Arrays allowing closer proximity for decoupling capacitors and other components. The underlying recess placement of components assists in minimizing reliability issues concerning surface mount components and provides closer proximity placement of components. The underlying recess placement of components is particularly useful for overcoming the problem of parasitic inductance of more distant component placements known in the art.
Claims20
A through-hole printed circuit board (PCB) comprising:
- a ball grid array (BGA) of BGA pads on one side of the PCB, arranged in a tight-pitch grid pattern;
- a milled recess on the same side of said PCB in said PCB adjacent and between a first and a second of said BGA pads of said ball grid array of BGA pads;
- said recess sized to contain a Surface Mount Component (SMC);
- a first pair of separated conductive pads at the bottom of said milled recess, each pad respectively conductively coupled to said first and second BGA pads.
A method of manufacturing a multilayer PCB wherein the PCB has a ball grid array (BGA) of BGA pads on one side of the PCB arranged in a grid pattern;
- the method comprising the steps of:
- milling a recess on the same side of said PCB in said PCB adjacent and between a first and a second of said BGA pads of said ball grid array of BGA pads, the bottom of said recess having arranging a first pair of separated conductive pads at the bottom of said milled recess, each pad respectively conductively coupled to said first and second BGA pads;
- sizing said recess to contain a Surface Mount Component (SMC);
- placing solder paste in said first pair of separated conductive pads;
- placing solder paste on said ball grid array (BGA) of BGA pads;
- placing an SMC within said recess;
- placing a BGA component over said SMC;
- reflow soldering said SMC component and said BGA component.
A computer aided design tool implemented on a computing device for accommodating a multilayer printed circuit board (PCB) wherein the PCB has a ball grid array (BGA) of BGA pads on one side of the PCB arranged in a grid pattern comprising:
- a design tool mode configured to select two adjacent BGA pads on the printed circuit board (PCB) for connection to a two-lead component;
- a design tool mode configured to identify a placement of a recess between said two BGA pads for containing a Surface Mount Component (SMC);
- a design tool mode configured to identify a placement of separated component pads on an inner layer of said PCB so as to define a bottom of said recess;
- and
- a design tool mode configured to conductively connect said separated component pads to a respective BGA pad of said two BGA pads.
Dependencies are inferred from the claim text.