In a message dated 7/31/98 6:53:20 AM Pacific Daylight Time,
[log in to unmask] writes:
<< We manufacture a high mix of PWBA's that have a large range of sizes,
heights and weights.
We are looking for a better way to handle them to help prevent damage
during assemblies handling. This includes boards banging into each other,
components getting bent over and assemblies being dropped. We currently
have a large mix of totes with dividers, which seem to always have the
dividers removed, racks that hold multiple assemblies vertically, but they
are unstable and deform parts along the edges of the boards and individual
boxes with foam inserts that prevent seeing the assembly for identification.
It seems that adjustable racks always need adjusting, flat trays take up
too much space, and a special box for each assembly requires a warehouse of
storage space.
I have seen some clear clamshell boxes that look somewhat versatile but
can't find the manufacturer.
I'm curious as to what other people are doing that have a high mix of board
types.
Thanks for any replies.
Ken Bloomquist
Sr. Principal Process Eng.
PRIMEX Aerospace Company
<www.primextech.com>
Show Director for Northcon
<www.northcon.org>
>>
Mornin' Ken,
I know what you're talking about. I've worked mostly in contract assembly
companies here in silicon valley, and there's always a high mix of boards on
the floor. The killer ones are the 18" X 20", 14-layer, $2,000 bare fab,
$7,000 loaded ones...after you have to buy one or two of those jewels from
dropping them and breaking a corner off, you start looking real hard to come
up with a better way.
What I found that works wonderfully, is the type of carts that handle
trays. Bliss Industries is one of the first ones that came out with them, but
I've seen a few other companies like Metro use the same concept. It's just a
cart that usually has 50-60 slots to handle conductive foam lined
trays...they're great. A little on the expensive side (start at $1,000 with
trays), but when you look at the price of a dropped board, ehhh...they're
cheap.
At the first company I got them at, I modified the movable rail on the
PTH slide line to open up a little further so we could use them right on the
line...that way it simplified the handling of the completed board from the
slide line to the cart that would move them to wave solder. Another benefit of
the trays is when moving unsoldered assemblies like that, is that with slotted
adjustable racks you can lose parts going across seams in the floor, but with
trays that's nearly impossible. With tilt racks the boards need to be within a
certain size...not too big, not too small...and the boards can't have any
components close to the edges of the board, otherwise they run the risk of
getting knocked of...you eliminate all those issues with trays.
I hope this helps,
-Steve Gregory-
################################################################
TechNet E-Mail Forum provided as a free service by IPC using LISTSERV 1.8c
################################################################
To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body:
To subscribe: SUBSCRIBE TechNet <your full name>
To unsubscribe: SIGNOFF TechNet
################################################################
Please visit IPC's web site (http://www.ipc.org) "On-Line Services" section for additional information.
For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312
################################################################
|
