Hello, a question for those of you with manufacturing experience:
At what point do the added cost and efforts for automated assembly make
sense?
Assuming the board is mostly SMT, properly designed and not terribly
complicated or large.
I realize this is a very vague question. I am just trying to get an idea of
what kind of quantities people consider worthy of automated assembly.
Thanx,
Tony
Tilmann Reh wrote:
Tony Rolando schrieb:
Your last line really provided some insight for me...
You can't give a general statement without caring about (all) details.
Chosing the optimum technology depends on very many details...
Tilmann
Agreed. It's all in the details. We do low-volume runs (10-100 per). Some
key details:
Setup charges vs Manual charges - there's usually a setup charge to load the
machine, but the run costs less. There's no setup charge for manual
assembly, but the run costs more. There's also typically a one-time
programming charge for the first run. Do the math.
Tape & Reel - machine runs require most parts on tape and reel. Do you have
tape and reel inventory?
Consistency - machine jobs are like ISO 9001 - if the setup is right, it's
always right; if it's wrong, all the boards are wrong. Once the programming
is done correctly machine jobs are usually more consistent both in the
current run and also for any later runs. How many future runs might this
board have?
Part density and complexity - 10 boards with 10 low-density SMT parts are
quicker to build manually. 10 boards with 500 SMT parts, of which a dozen
are very fine-pitch or BGA monsters, are far quicker and more precisely
done by machine. There is, unfortunately, no set quantity of parts, pitch
or whatever that you can plug into a formula to calculate where the
dividing line is.
We typically have prototype runs (3-10 boards) hand-stuffed unless they're
very complicated, because the programming and setup charges aren't
justified on a small-quantity run, when the board will almost certainly be
modified and the programming /setup will have to be redone anyway. Once a
board is in production, even small runs of 25 or so are typically
machine-assembled because it's quicker, higher-quality, and usually less
costly because the setup and programming remain consistent. We also have
most of our inventory on tape and reel.
Just some more detail data points to work with...
Tilmann Reh wrote:
Tony Rolando schrieb:
Your last line really provided some insight for me...
You can't give a general statement without caring about (all) details.
Chosing the optimum technology depends on very many details...
Tilmann
Agreed. It's all in the details. We do low-volume runs (10-100 per). Some
key details:
Setup charges vs Manual charges - there's usually a setup charge to load the
machine, but the run costs less. There's no setup charge for manual
assembly, but the run costs more. There's also typically a one-time
programming charge for the first run. Do the math.
Tape & Reel - machine runs require most parts on tape and reel. Do you have
tape and reel inventory?
Consistency - machine jobs are like ISO 9001 - if the setup is right, it's
always right; if it's wrong, all the boards are wrong. Once the programming
is done correctly machine jobs are usually more consistent both in the
current run and also for any later runs. How many future runs might this
board have?
Part density and complexity - 10 boards with 10 low-density SMT parts are
quicker to build manually. 10 boards with 500 SMT parts, of which a dozen
are very fine-pitch or BGA monsters, are far quicker and more precisely
done by machine. There is, unfortunately, no set quantity of parts, pitch
or whatever that you can plug into a formula to calculate where the
dividing line is.
We typically have prototype runs (3-10 boards) hand-stuffed unless they're
very complicated, because the programming and setup charges aren't
justified on a small-quantity run, when the board will almost certainly be
modified and the programming /setup will have to be redone anyway. Once a
board is in production, even small runs of 25 or so are typically
machine-assembled because it's quicker, higher-quality, and usually less
costly because the setup and programming remain consistent. We also have
most of our inventory on tape and reel.
Just some more detail data points to work with...
