Printed Circuit Design

Once the design is complete and simulations indicate that all functionality is present, it is time to turn the design into reality. Unfortunately, the days of simple "2-sided" circuits is pretty much gone. With component densities multiplying, device pin counts reaching several hundred, and component sizes shrinking, the process of designing printed circuits to accommodate them is no simple task. Signal crosstalk, line impedance, EMI, thermal management, reliability and producibility are all concerns that must be carefully included in the physical design of electronics. With our considerable expertise in all aspects of high-performance circuitry, we can provide you with a packaging design that is trouble free.

Capabilities

Multi-Layer

Nearly all printed circuit boards today are multi-layer laminations. Extremely dense circuitry with thousands of nets can require up to ten, twelve or more interconnect layers. Trace widths and spacing can be only a few thousandths of an inch with equally small pin pitches on modern SMT components. Integral ground and power planes are required to reduce noise and increase performance. Mixed digital and analog circuits can require special attention for noise isolation. Ever increasing clock speeds may require microstrip or stripline geometries with tightly controlled impedances. Materials can range from conventional epoxy-glass laminates to polyimide, kapton, and even Teflon. Blind or buried vias can further increase circuit densities, but at the expense of manufacturing cost.   All of these parameters must be considered to produce an optimal PCB design.

Flex Interconnect

As circuit densities increase, so do the complexity of the interconnects. As more and more circuitry is designed into smaller and smaller enclosures, the room for interconnects also shrinks.  Many times it is necessary to integrate the module-to-module interconnects into the printed circuits themselves. The use of very thin, flexible laminate materials allows multi-layer printed circuit approaches to be extended into three dimensions. Folds, curls, zig-zags and accordions can be used to push the limits of electronic packaging.

MCM & HDI

When conventionally packaged components (ICs) are still too large, the use of bare-die components is sometimes possible. Multi-Chip Modules and High-Density Interconnect Modules are only a couple of alternatives that can be used to further increase circuit densities. Although certainly more expensive to produce, these approaches can be the answer when near Chip-Scale Packaging (CSP) density is necessary.

Reference Accounts

• Boulder Nonlinear Systems

Last modified July 20, 1999
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