Electronics Forum | Fri Sep 07 08:57:28 EDT 2001 | Hussman
Por, You talking wave solder or reflow solder? At wave, nitrogen is the way to go. Just like you stated, it does affect the surface tension. If you're reflowing, I wouldn't go nitrogen unless you have to. Improper stencil design is usually the c
Electronics Forum | Sun Sep 09 10:53:05 EDT 2001 | bentzen
For reflow soldering, you are correct ! The higher surface tension of the solder paste in nitrogen atmosphere can increase the number of solder bridges if the component or solder paste print is inaccurate. Another defect that might increase is tomb
Electronics Forum | Tue Sep 04 11:09:25 EDT 2001 | blnorman
As the others have stated, moisture is the killer. You have to be sure no moisture is allowed to get to the paste. If it does, you'll get solderballs. I would suggest not using a vacuum. The solvents and other volatile components of the flux will
Electronics Forum | Wed Sep 26 14:58:46 EDT 2001 | bobm
i have stored boards in the refrigerator in side a tray (with a lid) for 2 days and still had them reflow with no problems. i don't know if i would go any longer than that. i would not put any qfp's or any other device that is moisture sensative dev
Electronics Forum | Tue Sep 04 07:34:02 EDT 2001 | Shvetang Dewashrayee
We have problems of solder shorts while using DEK Infinity printers. Some of the manufacturing lines are configured ina way that the side (bottomside) of PCBs mostly with passive parts is screened first and then the otherside (topside) of the PCBs w
Electronics Forum | Tue Sep 04 09:19:51 EDT 2001 | jhingtgen
Shvetang, From your post it is difficult to say why the shorts are occuring and in what area of the board. I offer my assistance to solving your issue, I am an Applications Eng with DEK USA. Please contact me via e-mail at jhingtgen@dek.com or phon
Electronics Forum | Fri Sep 07 09:19:44 EDT 2001 | Hussman
Jean, A lot depends on your process. can you add a dot of adhesive after screen printing and before placement? This works well for larger heavier parts. A second suggeestion is to reprofile your board. Try keeping the bottom side cooler. I do t
Electronics Forum | Wed Sep 05 10:58:28 EDT 2001 | Chris Cherry
We can perform testing on any size of boards or components and offer many different levels of service. We can provide full analysis and interpretation on a same day basis, or some people may choose to rent a lab for a period of time for extended pro
Electronics Forum | Wed Sep 05 09:36:05 EDT 2001 | Michael Fogel
I�m looking for some kind of equipment for marking S/N, W/O info etc. on our boards. This equipment can be any type of automatic labeler (print & stick) and up to Laser printer witch can print directly on the PC board. Any benchmark between the 2 met
Electronics Forum | Thu Sep 06 10:04:54 EDT 2001 | blnorman
We have started switching all our PCB marking from labels to Laser marking. We have a silkscreen patch put on the boards then use a CO2 laser to burn the mark off to produce the barcode. Our marking downtime has gone from an average of 8 hours a we
