Embedded Capacitance Material (ECM)

By 3M 93

Embedded Capacitance Material (ECM)

3M's embedded capacitance material (ECM) increases usable board area by allowing for the removal of many, if not all, capacitors equal to or below 0.1 μF and their associated solder joints and vias. The material consists of a very thin layer of ceramic-filled epoxy sandwiched between two layers of copper foil, allowing the user to simplify design while amplifying performance.

Imagine being able to remove all of these capacitors from the board. Surface-mounted discrete capacitors are usually ineffective above several hundred MHz. 3M’s ECM can replace a large number of discrete decoupling capacitors from the board surface. The ECM has been used in backplanes, daughter cards, modules, IC packaging, and flex circuits in the military/aerospace, telecom, computer, handheld, IC packaging, automotive, medical, and ATE market segments. 3M's ECM is RoHS complaint, compatible with lead-free assembly, does not contain bromine, and has UL recognition (ECM C0614). When looking at cost conclusions, the bare board costs will typically increase while system costs decrease.

3M’s ECM is a laminate of copper and epoxy with a high dielectric constant filler that can be embedded as a layer in a multilayer printed circuit board.  It can be patterned as a power and ground plane pair for a lower impedance, shared capacitance power distribution network.  It can also reduce noise and EMI by dampening board resonances.  Besides power and ground planes, it can also be patterned to specific values for individual capacitors.  In each of these cases, a reduction in the number of surface-mount, discrete capacitors can allow for a smaller PCB footprint or an increase in PCB functionality.

"Full" is full 100% etest, which is suggested for boards larger than 4 square inches. On smaller PCBs, the "audit" etest is suitable, where an occasional defect may have smaller impact on the finished product yield/cost. Full etest is more expensive than audit etest.

Discrete Capacitor Elimination on Telecom Board

Baseline Design (BGA1)
3M's ECM Embedded Capacitance Design (BGA1)



Baseline Design (BGA2)
3M's ECM Embedded Capacitance Design (BGA2)



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