Thanks for the tips, when you say offset du you mean rotated 15-24 degrees? We dont use wave solder footprints, in general they are according to IPC-7351 for reflow but they are not ideal. Our VP is a through conveyor model, profiling is not very practical. Grunde "Stadem, Richard D." <[log in to unmask]> 16.10.2008 15:03 To "TechNet E-Mail Forum" <[log in to unmask]>, <[log in to unmask]> cc Subject RE: [TN] FW: [LF] Vapor Phase Soldering After performing a DoE about 4 years ago I changed the pad layouts in the design library for 0805, 0402, and 0201 components, and changed the placement angle to 15-24 deg. offset. This results in the molten solder having to pull the part straight first before it can pull it up, but by that time both ends are in liquidus. Using this combination, we have had very few tombstones, although occasionally we do see 0201s billboard, but very few. We solder more than a million solder joints each month. Other companies that I do consulting for have adapted the same library with the same results, except they did it on assemblies that are primarily soldered with convection reflow. With convection, the offset is not so important, but the pad design is. You can map the profile of your assembly or process control tool the same way you do with a convection oven. I simply connect the thermocouples to the assembly per the IPC standard, and run it into the VPS and back out. The RD1 and RD2 have an in-and-back-out train, not a through conveyor. It is actually easier to run the profiler because I don't have to actually let the profiler go into the chamber. When our techs are profiling a new assembly, they use an actual PWB and load it with as many dummy or scrap parts as we can find. When they perform a process control verification, they use a fixture that has small metal clampdowns to hold each TC. This way I can replace TCs when they wear out without having to solder/epoxy them in place. Doing it this way maintains the integrity of the fixture. The only variation we see is due to the very small variation in thermocouples themselves. The mass of the clamps will actually give you a more accurate reading because they pick up the IR portion of the energy inside the oven as well as the convection temperature. The difference can be as much as 7-8 deg. C. -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Grunde Gjertsen Sent: Thursday, October 16, 2008 12:30 AM To: [log in to unmask] Subject: Re: [TN] FW: [LF] Vapor Phase Soldering Apart from tombstoning that is in my experience much worse than with convection. Another thing with VP, how do you document your temperature profile? Grunde "Stadem, Richard D." <[log in to unmask]> Sent by: TechNet <[log in to unmask]> 15.10.2008 17:51 Please respond to TechNet E-Mail Forum <[log in to unmask]>; Please respond to "Stadem, Richard D." <[log in to unmask]> To [log in to unmask] cc Subject Re: [TN] FW: [LF] Vapor Phase Soldering I should also opine that when soldering RoHS-compliant assemblies using lead-free solder paste, you will probably get a much better yield with VPS than you ever will with convection. Especially in the case of SAC solders. There, I said it. Listen to the screams..... -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Stadem, Richard D. Sent: Wednesday, October 15, 2008 10:38 AM To: [log in to unmask] Subject: [TN] FW: [LF] Vapor Phase Soldering -----Original Message----- From: Stadem, Richard D. Sent: Wednesday, October 15, 2008 10:34 AM To: '(Leadfree Electronics Assembly Forum)'; 'Tony Ingano' Subject: RE: [LF] Vapor Phase Soldering VP soldering is great for reflow of massive or hard-to-solder assemblies or when doing certain subassembly processes (socket manufacturing, etc.) They are an invaluable tool in any manufacturing facility. There are no process drawbacks with using the modern VPS machines, better preheaters and sumps fixed the issues of thermal shock and excessive vapor fluid use. 3M's Fluorinert and Galden PFPE fluids are safe to use from an environmental standpoint, per our PCA state offices. You must recognize that VPS requires some amount of thermal shock in order to facilitate the condensation action, but it is not usually so large as to hurt the reliability of most standard SMT components. There may be some heat-sensitive components that you would not want to solder with VPS, however. You need to do the homework before jumping in and running production hardware with VP. Homework is spelled q-u-a-l-i-f-i-c-a-t-i-o-n, which should include thermal cycling. But we get a lower DPMO when using VPS than we do with convection reflow ovens. Better, more uniform heat transfer = better solder wetting. I have used R&D Technical Services machines, Model RD1 and RD2, and they have worked extremely well for the companies that I work with. Find them at: http://www.rdtechnicalservices.com/index.html Disadvantages are the cost of the fluids, and the machines require more cleaning (maintenance) due to the amounts of flux contamination on the insides of the chamber from the vapor. We have our maintenance people thoroughly clean them each month as a means of preventing oxidation of the internal chamber parts. We use two temperatures of fluid, depending on the application. I am still waiting for Galden and 3M to get schmart and provide the different fluid tempertures in different colors so it is easier to avoid using the wrong temperature fluid. Anyone know of an inert dye that I can add to the fluid that would not affect its performance? -----Original Message----- From: Leadfree [mailto:[log in to unmask]] On Behalf Of Tony Ingano Sent: Wednesday, October 15, 2008 8:14 AM To: [log in to unmask] Subject: [LF] Vapor Phase Soldering I am wondering if anyone is currently using vapor phase soldering. What are the disadvantages of vp soldering? Also, who are the major manufacturers of VP soldering machines? Thanks, Tony ------------------------------------------------------------------------ -------Leadfee Mail List provided as a 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 Leadfree To temporarily stop/(start) delivery of Leadree for vacation breaks send: SET Leadfree NOMAIL/(MAIL) Search previous postings 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 847-615-7100 ext.2815 ------------------------------------------------------------------------ ------- --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 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 847-615-7100 ext.2815 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 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 847-615-7100 ext.2815 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 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 847-615-7100 ext.2815 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 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 847-615-7100 ext.2815 -----------------------------------------------------