I've been there. The problem I have now is that the vendor says it's a problem with the proflow and proflow setup. Dek says that it is a problem with the paste. (I tend to agree with dek from what I have seen.) The problem is that we chose this paste due to its reflow performance. It is very very good. However, our evaluations were done with squeegees because it is very difficult to obtain samples in proflow format. My first choice is to make this paste work, but if we have to look elsewhere, we will. Thanks. Henry. -----Original Message----- From: Jowan Iven [mailto:[log in to unmask]] Sent: Wednesday, September 25, 2002 10:26 PM To: 'TechNet E-Mail Forum.'; 'Henry Rekers' Subject: RE: [TN] Viscosity vs Temperature. Hi Henry! I've run into similar problems with the proflow system. We also had very good results with normal squeegees and poor results with proflow. I started a "Design of Experiment" to figure out what the reason could be. Very interesting data came out of the test , but not a solution. One very important parameter was deliberately not included in the test. The solderpaste. I just wanted the system to work with our standard solderpaste. When the conclusion was that our standard solderpaste failed in the proflowsystem, I started additional test with other pastes (types and brands). The results look very promising for now. Several pastemanufacturers are capable in producing a solderpaste that works well with Proflow. Contact your current supplier and you will probably find a solution together. Best regards, Jowan Iven Process Engineer Dept. Engineering & Technology Stork Electronics BV -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Henry Rekers Sent: donderdag 26 september 2002 0:45 To: [log in to unmask] Subject: [TN] Viscosity vs Temperature. We are having some issues with a new solder paste. The evaluations came out extremely well at first. However, upon using it for some trial runs, we run into some problems. In our DEK profolw the prints look very good at about 20 deg C. Throughout the day, the temp in our facility climbs to 28 or even 30 deg C. The prints then start to bridge and flux bleeds out onto the board. We can compensate for it to about 25 deg by reducing the proflow pressure and wiping on every print, but beyond 25 deg, nothing helps. By the time the 3rd shift rolls in, the temperature starts to drop again and the prints become more managable again. Here's the kicker, we use this same paste on our MPM with squeegee's and the print works every time. There is never a print problem vs temperature. Has anybody ever run into this situation? How did you solve it? Thanks in advance. Henry J. Rekers Manufacturing Engineer Power Measurement. ---------------------------------------------------------------------------- ----- Technet Mail List provided as a free 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/html/forum.htm for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ---------------------------------------------------------------------------- ----- --------------------------------------------------------------------------------- Technet Mail List provided as a free 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/html/forum.htm for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ---------------------------------------------------------------------------------