Marc DeCantillon asked:

>        I am currently involved in evaluating SMT equipment for a low to
>     medium volume, high mix, specialty PCBA's (high temp & vib with
>     possible TAB applications).  As with any consumer issue, I'm getting
>     varied reports on what the equipment can do.  I'm getting the "Our
>     latest software rev will take care of that" speech on some equipment.
>        Also, I am attending NEPCON East to get more info.  I was wondering
>     other than comparing spec.'s (speed, accuracy, heat profiling, etc.),
>     what are the intangibles that need to be considered?

Regarding pick and place, IMO the feeders are a key element. This can be
overlooked, and become a nightmare later.

Ballpark, they cost as much or more than the machines themselves, and
strongly affect how well your line will run.

There are usually several basic types you will have to buy, with varying
tape widths, advance mechanisms, cover tape handling, etc.

Look hard at how much each costs, how durable and reliable they appear to
be, availability of the types you must have, and the wear items (spare
parts) they will need, including both cost and availability. You may be
buying two hundred feeders costing $2-5K apiece. It's important to buy
enough of the ones you need, and to not get many which gather dust on the
shelf.

You probably want to have some feeders duplicated to reduce setup times, as
stripping and changing reels to new parts whenever you change setups can be
time consuming. This permits you to simply take the feeder offline and
replace it with a pre-loaded feeder.

Maintaining all your feeders in good working order is a major portion of
keeping your line up and running. Look for any evidence of strange
escapement designs with complex linkages and adjustments. When feeders jam
or misfeed, you have a non-running machine, and you have valuable parts
being mis-picked - ending up in ugly little piles somewhere inside your
machines...

I'd ask for a costed list of feeder spare parts, and check to be sure they
have them available. If you don't, you'll be flamed later when you discover
they want $120 apiece for that little plastic latch cover of which you need
25 or so every few months.

Drive a hard bargain on getting all the feeders upfront, and make a deal to
allow you to get a big discount for some time period after installation so
you can be sure you get all the types and quantities you need. IMO the
equipment suppliers get a fat profit on these, and will sometimes show you
a fantastic price on the basic machine, let you buy some minimum number of
feeders, then soak you when you later have to buy the ones you really
require.


regards,



Jerry Cupples
Interphase Corporation
Dallas, TX USA
http://www.iphase.com/