A new laminate material from 3M lets designers and manufacturers of high-speed digital printed circuit boards achieve higher speeds while simplifying design tradeoffs.
When used as ‘power’ and ‘ground’ layers in a multilayer PCB, 3M Embedded Capacitor Material becomes a decoupling capacitor inside the board.
According to 3M, embedded capacitance is more effective at decoupling high frequencies than surface mount discrete capacitors. Designers can achieve their decoupling requirements in less time and the reduction in discrete capacitors simplifies the task of board layout.
3M’s embedded decoupling approach is said to offer several advantages. It eliminates large numbers of decoupling capacitors, increases useable board area, enables faster signalling, lowers radiated emissions (EMI), and saves engineering time associated with power distribution design and board layout.
The material consists of an ultrathin adhesive layer sandwiched between two layers of copper foil. The patented adhesive formulation incorporates barium titanate particles to achieve a high dielectric constant and the combination of high dielectric constant and thinness delivers a capacitance of 5 nF/in2.