Hi > On Feb 18, 2021, at 6:53 AM, Poul-Henning Kamp <[email protected]> wrote: > > -------- > Bob kb8tq writes: > >> Turning an “idea” into a production capable part involves making many >> batches of test samples. Think in the thousands of batches and hundreds >> of parts in each batch. You have a “search” process at the blank chopping >> level. You also have a search at the resonator fabrication level. Getting >> the >> chopping part right is only a small part of the whole process…. > > I realize this used to be a manual process, but today I would expect > that you could automate a lot, of not most of it, if you wanted to ?
A normal crystal production line is *very* narrowly focused. Much of this narrow focus is related to the precision involved. It also is related to the investment involved. As you move from production to design optimization to research, the “range” of the equipment expands a lot. One random note: This whole “automation” process would have to go back to the quartz growing facility, since the bars are grown with a specific cut in mind. Consider that a “normal” process involves cutting that whole bar all at the same angle. For your robotic process, you likely would want to do something a bit different …. > > It would still be a lot of work, and very expensive, but like > biochemist trying out hundred of thousand compounds from their > "libraries", robots really lower the cost. The key point there indeed being cost to build all this gear. Let’s *guess* a bit here (and that’s all this is, a guess ….): All of your experiments would need to be turned into resonators and packaged in order to be characterized. Essentially you are making a crystal just like any other crystal. Making up a test of 50 in a group x 10 x 10 x 10 ( which is a pretty modest search) still is building 50,000 crystals. Is this some sort of pipe dream? Not really. The quantities per batch are a bit small compared to what is normally run. The search grid is a bit odd. However the total batch size is not at all unusual. In the open market, fully tested tested / characterized crystals aren’t going to sell for < $5. They are made and tested on the most automated gear anybody has …. (this does not include whatever your custom cutting process would cost). At this point, we have not discovered anything new. We simply have done one step in examining a *very* small part of “the space”. For a production part, this exploration is specific to the frequency / overtone / blank size you are digging into. The result might be: “We now know more about a 16.384 MHz third overtone that will fit in a T0-8 package. We can now hit a resistance spec of 45 ohms compared to the old spec of 60 ohms." > > The real question must therefore be, if anybody reasonably expects > there to be any superior "new" cuts to find in the first place ? You really don’t know what you might find … There are already 100’s of known cuts that are “better” in some way for some application. They aren’t in production anywhere, but they are “known”. > > What properties would you program a quartz-crystal-prototyping robot to > search for ? You very much want to (eventually) know about perturbations over temperature for a given resonator design at a specific frequency. That tends to be the “gotcha” on a new cut. Running 100% of the production through a 150C sweep at 1C per minute is *not* going to make the production people (or the customer) happy. > > Which parameter(s) of current crystal-cuts are "their weak point" ? More Q is always nice. Better ADEV never hurts Lower aging is popular Flat(er) temperature curves are attractive to an OCXO or TCXO designer That *assumes* you are after an oscillator crystal. If you are after a thermometer, accelerometer, pressure transducer, weigh scale, ……. you would probably be looking for other parameters. Bob > > -- > Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 > [email protected] | TCP/IP since RFC 956 > FreeBSD committer | BSD since 4.3-tahoe > Never attribute to malice what can adequately be explained by incompetence. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
