Electronics Forum | Thu Jul 09 21:04:50 EDT 1998 | Dave F
| Hi there, | I am looking for some informations concerning the shear or pull strength of a typical TQFP 20 mils leads in relationship with the Copper/Tin intermetalic layer thickness. Could anyone help? | | Thank in advandce. | rgs, | chiakl Chiakl
Electronics Forum | Sat Mar 15 09:30:29 EDT 2008 | davef
Unlike other solderability protection, immersion coatings [eg, ImAg, ImSn, OSP, etc] can be reworked by the board fabricator prior to assembly operations. Reasons for selecting immersion are: * Until a supplier can demonstrate that they can turn bla
Electronics Forum | Sun Dec 17 22:23:46 EST 2017 | jmelson
Well, I fixed it. I had resisted taking the motor off because of the recalibrations that would be required. But, it got bad enough I had to. Under the microscope, I could see copper dust packed between the commutator segments. I removed that, and
Electronics Forum | Fri May 01 08:15:36 EDT 2009 | davef
Scavenging Methods [Improve Solder Scavenging of Large Area-array Sites, SMT, Laurence Harvilchuck, process research engineer, Unovis Solutions, harvilch@unovis-solutions.com] Two common methods exist for scavenging residual solder on the site for s
Electronics Forum | Tue May 23 20:39:37 EDT 2000 | Dave F
Scott: Sounds like fun: � Solder joint strength in pull/shear varies with lead geometry, solder volume, lead metal/metallization, and the test method. � Among things, IPC-TM-650 talks to getting pads off-of boards. For instance: Method 2.4.8 is for
Electronics Forum | Thu May 05 03:22:38 EDT 2005 | Hannu
I do not mean big, heavy transformers but rather small ferrite core transformers, with ferrites in the range of EF16 .. EF40. The weight of the lead and its percentage of the total weight is not the issue here. We simply do not want lead-containing t
Electronics Forum | Tue Jul 05 11:00:37 EDT 2005 | patrickbruneel
Inds, This will happen with all lead-free alloys having a tin content above 70%. It takes about 30 sec. for a molten lead-free alloy to totally dissolve a copper pad. The higher the temperature the shorter the time and visa versa. The scary part of
Electronics Forum | Thu Feb 18 22:49:49 EST 1999 | Chris G.
| We are using .040" diameter fiducials (global and local) on our boards. They are solder covered and HASL. I get batches of boards where the p&p vision system has trouble reading the fiducial. The fiducial looks dark on the screen. The board ven
Electronics Forum | Thu Apr 06 04:38:21 EDT 2006 | dougs
Hi, We have just purchased a new rework station, i'm looking for tips to get the best quality rework possible. Currently when we are replacing a SMT component we take off the old one clean the pads with solder braid then IPA, re-tin the pads the
Electronics Forum | Fri Dec 04 20:37:45 EST 1998 | kallol chakraborty
| | | | | Hi folks , | | | | | Lately we are seeing a lot of rawcards with black spots on the pads - most of them have Au finish(immersion gold) . We did a lot of inspecton after wave solder and found that only (fine pitch) QFP are affected the most
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