Don't forget that the carts must be ESD protective or you will be constantly reworking for blown components. Al Cash > ---------- > From: Stephen R. Gregory[SMTP:[log in to unmask]] > Reply To: TechNet E-Mail Forum.;[log in to unmask] > Sent: Friday, July 31, 1998 10:37 AM > To: [log in to unmask] > Subject: Re: [TN] PWBA Handling > > 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 > ################################################################ > ################################################################ 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 ################################################################