Electronics Forum | Wed Jul 03 15:40:17 EDT 2013 | davef
Shear tests are [in my opinion] senseless. The shear stress you measure depends more on the shear rate and on the point where the force is applied than on the grain structure. When shearing a component, you not only apply shear stress, but also roll
Electronics Forum | Tue Jun 26 07:15:06 EDT 2007 | zanolli
I've used PVC, black iron and copper: Forget PVC, too dangerous as joint strength completely reliant on glue, black iron will rust and accumulate debris over time, copper is the best but now because of very high Cu commodity prices could very well be
Electronics Forum | Tue Mar 29 14:45:12 EST 2005 | davef
IPC-TM-650 TEST METHODS MANUAL Number 2.4.21.1 Subject: Bond Strength, Surface Mount Lands Perpendicular Pull Method 1 Scope This test method is used to determine the bond strength (breakaway strength) of surface mount lands from substrate materials
Electronics Forum | Sun Jan 11 12:03:51 EST 1998 | Bob Willis
As a basic guide the minimum spec you should look for is 500g you should achieve a force on most chip parts of 800-1000g. Parts are lost on wave soldering due to no material, poor curing, poor surface adhesion and poor handling. Its not the wave sold
Electronics Forum | Mon Jul 30 21:07:35 EDT 2001 | davef
So, yer loosing parts between place and reflow? That would seem to say yer: * Paste has lost tackiness [check the fine SMTnet Archives for a sample test.]. * Really not placing the parts that you think yer placing. * Knocking the parts out of place
Electronics Forum | Tue Mar 22 07:39:05 EST 2005 | davef
There is no standard. This is a relative test. If you wish to do tests of this kind, we suggest to pay attention to the following points: * Shear strength of soft solder depends on the deformation speed applied. The faster the material is deformed t
Electronics Forum | Wed Oct 06 22:55:14 EDT 2004 | davef
Your customer is correct. Components should not fall a board during a reasonable drop test. A shear test poorly represents a drop test. A drop test represents a drop test very well. If you want to proceed with shear testing, search the fine SMTne
Electronics Forum | Fri Apr 19 15:52:31 EDT 2002 | davef
So, what is 'high voltage'? anywho? * We sort of use 10 kV as the starting point for 'high voltage'. * National Electrical Code defines a much lower starting point (300 or 600 V?),
Electronics Forum | Thu Apr 18 16:55:39 EDT 2002 | davef
Yes. Ceramic is much better. We use FR4 in fairly high voltage circuits. What are the particulars? * Where are you arcing * How many layers, prepreg, etc
Electronics Forum | Thu Apr 18 11:44:34 EDT 2002 | jsmith01
Does anyone know of a PCB material that is better at preventing arcing than fr4 or g10?
