Scott, We've made pallets for this and there are two ways of thinking. Some prefer to keep the bottom protected and thus insulate the bottom side components. We've done this for years and it seems to work fine. Over the past couple of years we have made them with holes in the bottom side so that the bottom reflows also. The only complaint we have seen is that sometimes times parts fall off the back and go into the converyor. I imagine this is a problem that is rare if your process and machine are in good order. We have had some people use our pallets for the sole purpose of keeping the parts from falling into the machine. You can give me call off line if you'd like. Jim Gleason 972-494-1911 -----Original Message----- From: TechNet [mailto:[log in to unmask]]On Behalf Of Jiang Ping Sent: Tuesday, June 12, 2001 10:58 PM To: [log in to unmask] Subject: Re: [TN] Dual Side Reflow with A Pallet Hi, We have a similar board that double side reflow with a pallet. The pallet actually is a frame with two beams. There are some support pins on the beams that keep away from bottom components. When boards are put on the pallet and clamped, the bottom side is not covered, so all the bottom side solder joints are fully reflowed in the oven. It works very well. Hope that helps. Jiang Ping ----- Original Message ----- From: Lefebvre, Scott <[log in to unmask]> To: <[log in to unmask]> Sent: Wednesday, June 13, 2001 6:26 AM Subject: [TN] Dual Side Reflow with A Pallet > I have an new assembly that is 14"x18" & .093 thick loaded with 16mil fine pitch, BGA's and what ever else they could fit on the board. The bottom side has chip resistors, caps, and 8 TQFP's. > > My question is I was thinking about putting the board in a pallet to prevent warpage but I was concerned that the bottom side solder may be effected during the Top side reflow. Normally bottom side components reach liquidus and then cool back down. I was concerned using a pallet they solder on the bottom side might stay just below liquidus and create a plastic solder joint. I have used pallets in the past only on hybrids. > > Any help with this issue would be greatly appreciated! > > Scott Lefebvre > Process Engineer > ADC > > F (530)265-1041 > > 8 (530)265-1012 > > * [log in to unmask] > > > > > > > > > > > > -------------------------------------------------------------------------- ------- > Technet Mail List provided as a free service by IPC using LISTSERV 1.8d > To unsubscribe, send a message to [log in to unmask] with following text in > the BODY (NOT the subject field): SIGNOFF Technet > To temporarily halt delivery of Technet send the following message: SET Technet NOMAIL > Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives > Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional > information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 > -------------------------------------------------------------------------- ------- Mj uyy< ! nzj MT9 µ x`rz rzMz zM4 j j¢yz ><nzr riyIj ӷ --------------------------------------------------------------------------------- Technet Mail List provided as a free service by IPC using LISTSERV 1.8d To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt delivery of Technet send the following message: SET Technet NOMAIL Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ---------------------------------------------------------------------------------