Electronics Forum | Fri Sep 15 05:48:24 EDT 2000 | carsonho
Have any experience that Sn/Pb plated integrated circuit products will appear some rainbowbridge-like substance after exposing at conditions of 121degC, 100%RH and 15psi for 48hours or above? The rainbow bridge substance was analyzed by EDAX and fou
Electronics Forum | Fri Sep 15 05:48:11 EDT 2000 | carsonho
Have any experience that Sn/Pb plated integrated circuit products will appear some rainbowbridge-like substance after exposing at conditions of 121degC, 100%RH and 15psi for 48hours or above? The rainbow bridge substance was analyzed by EDAX and fou
Electronics Forum | Thu Aug 24 16:59:11 EDT 2000 | Dr. Ning-Cheng Lee
For reflowed solder joints, Bi bearing solder has been reported to exhibit superior fatigue resistance. It also provides better wetting than many other alternatives, including SnAgCu systems. In my opinion, it may be the choice once all Pb can be pha
Electronics Forum | Thu Aug 24 17:08:58 EDT 2000 | Dr. Ning-Cheng Lee
Depending on the stress condition experienced by the solder joints. For joints under a greater stress, the time to reach equilibrium can be shorter. Of course, the change is also more significant in phase structure. For low stress conditions, it may
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 16:46:52 EDT 2000 | Dr. Ning-Cheng Lee
Comparing 62Sn/36Pb/2Ag with 63Sn/37Pb, addition of 2% Ag introduces two major advantages. The first advantage is grain refining, and the resultant better fatigue resistance. The second advantage is a wider processing window on Ag metallization. Pres
Electronics Forum | Wed Aug 23 16:29:16 EDT 2000 | Dr. Ning-Cheng Lee
The surface tension of solder you mentioned should be referred to as interfacial tension between solder and flux. According to Antonow�s rule, the interfacial tension is the difference in surface tension of molten solder and liquid flux. Since flux a
Electronics Forum | Wed Aug 23 16:18:47 EDT 2000 | Dr. Ning-Cheng Lee
I presume you are referring to vibration test with fixed frequency at room temperature. One procedure describing the detailed profile is in MIL-STD-883E, Method 2005.2 (12/31/96). The approximate profile can be described as 60Hz, 20-70g, and 96 hrs t
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 | Wed Aug 23 15:10:24 EDT 2000 | Dr. Ning-Cheng Lee
Fillet lifting is a phenomenon mostly observed at wave soldering. It is caused by mismatch in thermal expansion coefficient (TCE) between solder and parts, and aggravated by the pasty range of solder alloys. Upon cooling, the mismatch in TCE will cau
Nordson Electronics Solutions makes reliable electronics an everyday reality. Our ASYMTEK, MARCH, and SELECT brands deliver precision fluid dispensing, conformal coating, plasma treatment and selective soldering equipment.
2747 Loker Ave West
Carlsbad, USA
Phone: 18002796835
