Question: what's the status of circuit-board manufacture houses these days? I had some planar microwave sensors fabricated through a board house years ago, and they were depressingly ifp. Is that changing?
We do 100% of our designs in hard metric. All PC houses can accept them that way. Some of the smaller houses (used for prototype and/or small runs of 2-layer boards) do convert them to colloquial units before fabrication.
The better and larger board houses (for large runs or multi-layer boards) use the files we provide as is. All of the modern NC machinery (photoplotting, drilling, routing) can work perfectly fine in metric, so there is no reason for a competent board house not to use metric. I believe they will still also accept boards designs with colloquial files, so they are "bilingual" in measurements.
On a related topic, the vast majority new electronic components (passives, actives, connectors, etc.) are being designed in hard metric, and many drawings we get from vendors no longer even include colloquial equivalents.
This is not to say that we won't have some historical non-metric parts around for years (e.g., the ubiquitous "D" connector, which isn't even a "hard inch" design), but the electronics manufacturing industry has clearly chosen to "Go Metric."
Jim Elwell, CAMS Electrical Engineer Industrial manufacturing manager Salt Lake City, Utah, USA www.qsicorp.com
