Electronics Forum | Wed Aug 23 17:06:40 EDT 2000 | Dr. Ning-Cheng Lee
For 20 mil pitch pads, the volume control is more critical in terms of bridging concern. In general, solder paste for dispensing is more prone to slumping due to low metal load and low viscosity. If the volume dispensed is on the high end, or if the
Electronics Forum | Wed Aug 23 15:19:11 EDT 2000 | Dr. Ning-Cheng Lee
From solder material point of view, a solder paste with slow coalescence rate, or slow wetting rate, will be most desirable. Processwise, allowing the paste to stay at soaking zone for longer time will dry out the volatiles, and reduce the chance of
Electronics Forum | Tue Aug 22 11:03:45 EDT 2000 | Dr. Ning-Cheng Lee
Hi Kelvin, Regarding to the surface finish of the leads, Sn or Pd may be the direction that the industry takes. First of all, the answer must be "Pb-Free", limiting our choices. Sn has good solderability, and it won't have too great of an impact o
Electronics Forum | Thu Jul 20 16:45:54 EDT 2000 | Darby
Good morning Bob. Darby from Australia here. We sometimes see an orange peel type finish on our reflow solder joints when viewed under the microscope. Any ideas on what causes this ? Should I worry about it. I use a straight rise profile ( no "platea
Electronics Forum | Thu Jul 20 16:56:38 EDT 2000 | Bob Willis
What do you mean good morning, my wine bottle is empty and I feel like sleeping. When will some one invite me back to your country to work again ? I need to do some more diving ? The most common cause is simpley the flux on the surface of the joint.
Electronics Forum | Thu Jul 20 14:02:31 EDT 2000 | Deon Nungaray
Hi Bob, I know that that conductive adhesives have been considered as a lead relacement in the past, but have been ruled out due to cost and other process issues (surface tension etc..) IBM has extensive development data on the topic and had come up
Electronics Forum | Thu Jul 20 14:02:28 EDT 2000 | Deon Nungaray
Hi Bob, I know that that conductive adhesives have been considered as a lead relacement in the past, but have been ruled out due to cost and other process issues (surface tension etc..) IBM has extensive development data on the topic and had come up
Electronics Forum | Thu Jul 20 14:44:26 EDT 2000 | Bob Willis
If you are getting skips on these parts the most common reason for skips is gassing and wave too low. I would agree that wave soldering these parts is not ideal. If the shorts are always in the same location on one or two pins a glue dot done during
Electronics Forum | Sat May 19 02:54:20 EDT 2001 | S.FitzPatrick
T.W.I.M.C. I am trying to located a copy, or at least the proper number, for the ISO standards on soldering, rework, and PCB wiring. I am about to start up a SMT solder rework class at work. I recall that when I worked for Solectron
Electronics Forum | Sat May 26 04:57:53 EDT 2001 | Brian Sloth Bentzen
Dear Frang. The right O2 level are mostly determined by the products you produce (E.i. PCB surface and component solderability). In reflow I would say the window is between 100 and 1000 ppm, depending on the issues above. Personal I choose a maximu
