Because they don’t support a multilevel hierarchical finished goods BoM.

The rate of MES system implementations in electronics manufacturing is not slowing. The rise of Industry 4.0 and the concept of big data have stimulated many companies to seek ways of collecting all important data in real time. If implemented properly, Industry 4.0 will eliminate the need for MES systems. Taking their place will be cyber-physical systems using machine-to-machine (M2M) communication and big data used to make intelligent decisions to run production without any human intervention.

There are still no signs, however, that we will come to terms with which M2M standard to use for Industry 4.0. Among Japanese machine vendors, an IPC-led effort, an ASM-led effort, and a Siemens-led effort, everyone else is left guessing what will happen and if an industry-wide standard will emerge at all. Until that happens, and until machine vendors implement better support for Industry 4.0, electronics manufacturers are pushing forward with MES implementations.

To increase signal quality, match the impedance, capacitance and inductance of all areas of the signal path.

In PCB design and fabrication, possibly the most frequently used, yet least understood, term is impedance.

Most of us have seen the buzzwords that accompany it: impedance Zo, 50Ω, 10%, balanced lines, microstrip, stripline ground plane, dielectric loss, dielectric constant, and others. What do they mean?

In this first of a two-part column, we’ll start by defining them in common terms for the novice. By the end, a few more people might make better sense of what is happening inside the circuit board. The second half will take a more thorough look at impedance.

First, why do we need impedance specifications? When a fast rise time signal (i.e., a 100MHz to 10GHz or higher pulse) travels down a PCB trace without impedance matching, not much of any use comes out the other end of the trace. What does come out is only a percentage of the original signal, with rounded-off edges and ringing on the trailing edge.

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