Hi Pankaj! I have a board like that here that we build, and at first it gave me the same problems you face. This might sound out of the ordinary, but you do what you have to do when you are faced with a board that is unusually thick and has heavy copper planes in it. I run the assembly twice through my wave machine. Once with the wave pumps off to pre-heat it, then once again with the pumps on. You could accomplish the same thing by pre-heating the board in a oven, but I don't have a oven close by my wave machine, so I use the wave pre-heaters instead. I also flux the topside of the board manually to help aid heat transfer a little, and it seems to improve capillary action too. I also use both the rotary and laminar wave pumps. I have a Electrovert Electra machine with a Optiflux-1 spray fluxer. The machine has three bottomside convection pre-heaters. I run my beltspeed at 3.5 feet per minute, and my pre-heaters are set at 270 F., 280 F., and 300 F. going from the entrance to the solderpot. I use a Alpha 615-25 RMA flux. I leave the fluxer on for both passes through the machine. I use a fixture for the board that has solder dams around all four sides, so I can run the board quite a bit deeper in the wave than normal. As far as rework on the board I use a system from Zephrytronics (http://www.zeph.com/) called a ZT-6 Hot Air Fountain. I was turned on to this system from a Technetter named Steve Sauer. I couldn't rework anything on this board without damaging pads, barrels, or the PCB itself until I got the ZT-6. I put some pictures up on my web page a while back of me pulling a 96-pin connector out of that board. Look at: http://www.stevezeva.homestead.com/files/ZT6.jpg http://www.stevezeva.homestead.com/files/TakingTemperature.jpg http://www.stevezeva.homestead.com/files/JustAbout.jpg http://www.stevezeva.homestead.com/files/ItsOut.jpg There's a picture of the unit, me monitoring the temperature with a hand-held, non-contact, I/R Thermometer, me getting ready to pull the connector out, and then me finally pulling the connector out with a pair of tweezers...couldn't be easier! -Steve Gregory- Dear Tecnetters " Hi " we have a PCB of 12 layers with thickness of 3.2mm. Problems we are facing are 1.Solder doesn't come top side and as the thickness is more than pre established components lead lengths ,like DIP's IC,connectors pins , it is mandatory for us that a fully wetted solder is visible from primary side. 2.Many of the components are on the ground plane , so if any rework is required we could not do so by soldering iron ( we tried weller 150 watts iron with temp. 450 deg. C , but we could not remove an electrolytic cap.) 3.What IPC tells about the power connector lead protrusion and the top side solder fill up for the same. As the IPC 610B states in components installation 3.5.3.1/note: that lead protrusion may not be visible in more than 2.3mm thick boards.How we interrelate it with soldering 4.1/vertical fill of soldering 75 % in this case. 4.We are using AC by pass connector "PICH47F400A1" with recommended PCB hole dia 2.1mm for lead dia 1.6mm , Is it enough for 3.2mm thick PCB too. Any body have the soldering experience of 3.2mm thickness PCB. what parameters ( wave height/ pre heater temp ) of wave soldering M/c matter in this case .Is chip wave is useful , Pls. share your exp. it will be highly appreciated. Thanks BR Pankaj Karnwal Jr. Engineer QA Barco Electronics System (P) Ltd. Plot no. A- 4 & 5, Sector- 5 G.B Nagar, Noida - 201301 India Tel .+91-120-2421651-660 Ext.211 Fax.+91-120-2421691 WWW.barco.com mailto:[log in to unmask] --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e 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 or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 -----------------------------------------------------