Through Hole vs. Surface Mount
in [Design]
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From: Fred Bartoli on 2 Apr 2010 12:04 Joerg a �crit : > JosephKK wrote: >> On Thu, 01 Apr 2010 10:50:50 -0700, Joerg <invalid(a)invalid.invalid> >> wrote: >> >>> JosephKK wrote: >>>> On Wed, 31 Mar 2010 13:25:55 -0700, Joerg <invalid(a)invalid.invalid> >>>> wrote: >>>> >>>>> John Devereux wrote: >>>>>> Joerg <invalid(a)invalid.invalid> writes: >>>>>> >>>>>>> Archimedes' Lever wrote: >>>>>>>> On Tue, 30 Mar 2010 09:42:05 -0700, Joerg <invalid(a)invalid.invalid> >>>>>>>> wrote: >>>>>>>> >>>>>>>>> All I can tell you is that there is no glop. I just did a few more >>>>>>>>> solder joints and held them under a magnifier -> nada, zilch, >>>>>>>>> clean. >>>>>>>>> >>>>>>>>> Maybe you used the wrong temperature? My Weller is running at 640F >>>>>>>>> right now. >>>>>>>> Most 'no-clean' hand operations I ever saw left the perfectly >>>>>>>> formed >>>>>>>> solder joint encapsulated in a thin flux film. Are you sure >>>>>>>> that you are >>>>>>>> not just too old or too non-detail oriented to 'see' it, even >>>>>>>> though it >>>>>>>> is there? >>>>>>>> >>>>>>>> The flux does not evaporate, and is, by design, meant to >>>>>>>> remain, so it >>>>>>>> *has* to be there... literally. >>>>>>> Ok, but it hasn't corroded or otherwise tainted one lone solder >>>>>>> joint >>>>>>> in years. If it does cause a failure 300 years down the road I >>>>>>> think I >>>>>>> could live with that :-) >>>>>> We use it for everything, never had a problem either. >>>>>> >>>>>> I take "no-clean" to mean "do not clean". I have heard (here) of >>>>>> problems when cleaning is attempted, the insulating component is >>>>>> washed >>>>>> away leaving an ionic residue which can absorb water and conduct. Or >>>>>> something. >>>>>> >>>>> Even then I had no problems. Many times in my lab I lash up jigs, >>>>> on Monday for example a tester to run transformers at 50Hz, 60Hz, >>>>> 400Hz or wherever. That stuff gets a beating over time, alligator >>>>> clips are attached to soldered areas over and over again so things >>>>> become scraped. Never a problem. >>>> Try it for high impedance circuits >> 1E7 Ohms. >>> >>> I avoid that wherever possible. If needed it's best to work with >>> guard rings. >> >> So do i, still, i did enough stuff at 1E8 Ohms and some much higher >> (1E12 Ohms) to have a real respect for doing that routinely. > > > Ok, but that's a specialty area. There will always be specialty areas > where normal design techniques aren't good enough. All I am saying is > that IME No-Clean is quite ok for all the regular designs I did. And > this has included some hardcore low-noise stuff. > No clean has no pb at all with low noise designs since low noise designs have pretty low impedances. That's high impedance low level that's tough. The small sensors I'm working on have 0603 1G fb resistors plus caps, and have to works for decades at elevated temperature (possibly up to 125C) and the very last one has 0402 100M resistors and caps. No clean is a no-no... -- Thanks, Fred.
From: Joerg on 2 Apr 2010 18:17 Fred Bartoli wrote: > Joerg a �crit : >> JosephKK wrote: >>> On Thu, 01 Apr 2010 10:50:50 -0700, Joerg <invalid(a)invalid.invalid> >>> wrote: >>> >>>> JosephKK wrote: >>>>> On Wed, 31 Mar 2010 13:25:55 -0700, Joerg <invalid(a)invalid.invalid> >>>>> wrote: >>>>> >>>>>> John Devereux wrote: >>>>>>> Joerg <invalid(a)invalid.invalid> writes: >>>>>>> >>>>>>>> Archimedes' Lever wrote: >>>>>>>>> On Tue, 30 Mar 2010 09:42:05 -0700, Joerg >>>>>>>>> <invalid(a)invalid.invalid> >>>>>>>>> wrote: >>>>>>>>> >>>>>>>>>> All I can tell you is that there is no glop. I just did a few >>>>>>>>>> more >>>>>>>>>> solder joints and held them under a magnifier -> nada, zilch, >>>>>>>>>> clean. >>>>>>>>>> >>>>>>>>>> Maybe you used the wrong temperature? My Weller is running at >>>>>>>>>> 640F >>>>>>>>>> right now. >>>>>>>>> Most 'no-clean' hand operations I ever saw left the perfectly >>>>>>>>> formed >>>>>>>>> solder joint encapsulated in a thin flux film. Are you sure >>>>>>>>> that you are >>>>>>>>> not just too old or too non-detail oriented to 'see' it, even >>>>>>>>> though it >>>>>>>>> is there? >>>>>>>>> >>>>>>>>> The flux does not evaporate, and is, by design, meant to >>>>>>>>> remain, so it >>>>>>>>> *has* to be there... literally. >>>>>>>> Ok, but it hasn't corroded or otherwise tainted one lone solder >>>>>>>> joint >>>>>>>> in years. If it does cause a failure 300 years down the road I >>>>>>>> think I >>>>>>>> could live with that :-) >>>>>>> We use it for everything, never had a problem either. >>>>>>> >>>>>>> I take "no-clean" to mean "do not clean". I have heard (here) of >>>>>>> problems when cleaning is attempted, the insulating component is >>>>>>> washed >>>>>>> away leaving an ionic residue which can absorb water and conduct. Or >>>>>>> something. >>>>>>> >>>>>> Even then I had no problems. Many times in my lab I lash up jigs, >>>>>> on Monday for example a tester to run transformers at 50Hz, 60Hz, >>>>>> 400Hz or wherever. That stuff gets a beating over time, alligator >>>>>> clips are attached to soldered areas over and over again so things >>>>>> become scraped. Never a problem. >>>>> Try it for high impedance circuits >> 1E7 Ohms. >>>> >>>> I avoid that wherever possible. If needed it's best to work with >>>> guard rings. >>> >>> So do i, still, i did enough stuff at 1E8 Ohms and some much higher >>> (1E12 Ohms) to have a real respect for doing that routinely. >> >> >> Ok, but that's a specialty area. There will always be specialty areas >> where normal design techniques aren't good enough. All I am saying is >> that IME No-Clean is quite ok for all the regular designs I did. And >> this has included some hardcore low-noise stuff. >> > > No clean has no pb at all with low noise designs since low noise designs > have pretty low impedances. > That's high impedance low level that's tough. > > The small sensors I'm working on have 0603 1G fb resistors plus caps, > and have to works for decades at elevated temperature (possibly up to > 125C) and the very last one has 0402 100M resistors and caps. > Well, that _is_ specialty stuff. Other than guard-ringed input circuitry I can't remember ever having gone above 18M. Because anything above 18M can become a purchasing problem. Also, higher-Z nodes will need to be under some sort of coating or it'll all fall apart in high humidity places. Puerto Rico, for example. > No clean is a no-no... > So how do you clean the flux residue from underneath that 0402 then? Specially trained microbes? Watch out that they don't form a union some day :-) -- Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM.
From: Tim Williams on 3 Apr 2010 00:33 "Joerg" <invalid(a)invalid.invalid> wrote in message news:81n8o5FivsU1(a)mid.individual.net... > So how do you clean the flux residue from underneath that 0402 then? > Specially trained microbes? Watch out that they don't form a union some > day :-) That would be called a biofilm, and yes, they become just as slippery as human unions are. ;-) Tim -- Deep Friar: a very philosophical monk. Website: http://webpages.charter.net/dawill/tmoranwms
From: JosephKK on 3 Apr 2010 03:04 On Fri, 02 Apr 2010 18:04:58 +0200, Fred Bartoli <myname_with_a_dot_inbetween(a)free.fr> wrote: >Joerg a écrit : >> JosephKK wrote: >>> On Thu, 01 Apr 2010 10:50:50 -0700, Joerg <invalid(a)invalid.invalid> >>> wrote: >>> >>>> JosephKK wrote: >>>>> On Wed, 31 Mar 2010 13:25:55 -0700, Joerg <invalid(a)invalid.invalid> >>>>> wrote: >>>>> >>>>>> John Devereux wrote: >>>>>>> Joerg <invalid(a)invalid.invalid> writes: >>>>>>> >>>>>>>> Archimedes' Lever wrote: >>>>>>>>> On Tue, 30 Mar 2010 09:42:05 -0700, Joerg <invalid(a)invalid.invalid> >>>>>>>>> wrote: >>>>>>>>> >>>>>>>>>> All I can tell you is that there is no glop. I just did a few more >>>>>>>>>> solder joints and held them under a magnifier -> nada, zilch, >>>>>>>>>> clean. >>>>>>>>>> >>>>>>>>>> Maybe you used the wrong temperature? My Weller is running at 640F >>>>>>>>>> right now. >>>>>>>>> Most 'no-clean' hand operations I ever saw left the perfectly >>>>>>>>> formed >>>>>>>>> solder joint encapsulated in a thin flux film. Are you sure >>>>>>>>> that you are >>>>>>>>> not just too old or too non-detail oriented to 'see' it, even >>>>>>>>> though it >>>>>>>>> is there? >>>>>>>>> >>>>>>>>> The flux does not evaporate, and is, by design, meant to >>>>>>>>> remain, so it >>>>>>>>> *has* to be there... literally. >>>>>>>> Ok, but it hasn't corroded or otherwise tainted one lone solder >>>>>>>> joint >>>>>>>> in years. If it does cause a failure 300 years down the road I >>>>>>>> think I >>>>>>>> could live with that :-) >>>>>>> We use it for everything, never had a problem either. >>>>>>> >>>>>>> I take "no-clean" to mean "do not clean". I have heard (here) of >>>>>>> problems when cleaning is attempted, the insulating component is >>>>>>> washed >>>>>>> away leaving an ionic residue which can absorb water and conduct. Or >>>>>>> something. >>>>>>> >>>>>> Even then I had no problems. Many times in my lab I lash up jigs, >>>>>> on Monday for example a tester to run transformers at 50Hz, 60Hz, >>>>>> 400Hz or wherever. That stuff gets a beating over time, alligator >>>>>> clips are attached to soldered areas over and over again so things >>>>>> become scraped. Never a problem. >>>>> Try it for high impedance circuits >> 1E7 Ohms. >>>> >>>> I avoid that wherever possible. If needed it's best to work with >>>> guard rings. >>> >>> So do i, still, i did enough stuff at 1E8 Ohms and some much higher >>> (1E12 Ohms) to have a real respect for doing that routinely. >> >> >> Ok, but that's a specialty area. There will always be specialty areas >> where normal design techniques aren't good enough. All I am saying is >> that IME No-Clean is quite ok for all the regular designs I did. And >> this has included some hardcore low-noise stuff. >> > >No clean has no pb at all with low noise designs since low noise designs > have pretty low impedances. >That's high impedance low level that's tough. > >The small sensors I'm working on have 0603 1G fb resistors plus caps, >and have to works for decades at elevated temperature (possibly up to >125C) and the very last one has 0402 100M resistors and caps. > >No clean is a no-no... Thanks, it may work for me in ordinary applications then. Until i find some specific need i will limp along on my Pb/Sn eutectic with rosin core.
From: Fred Bartoli on 3 Apr 2010 03:14
Joerg a �crit : > Fred Bartoli wrote: >> Joerg a �crit : >>> JosephKK wrote: >>>> On Thu, 01 Apr 2010 10:50:50 -0700, Joerg <invalid(a)invalid.invalid> >>>> wrote: >>>> >>>>> JosephKK wrote: >>>>>> On Wed, 31 Mar 2010 13:25:55 -0700, Joerg >>>>>> <invalid(a)invalid.invalid> wrote: >>>>>> >>>>>>> John Devereux wrote: >>>>>>>> Joerg <invalid(a)invalid.invalid> writes: >>>>>>>> >>>>>>>>> Archimedes' Lever wrote: >>>>>>>>>> On Tue, 30 Mar 2010 09:42:05 -0700, Joerg >>>>>>>>>> <invalid(a)invalid.invalid> >>>>>>>>>> wrote: >>>>>>>>>> >>>>>>>>>>> All I can tell you is that there is no glop. I just did a few >>>>>>>>>>> more >>>>>>>>>>> solder joints and held them under a magnifier -> nada, zilch, >>>>>>>>>>> clean. >>>>>>>>>>> >>>>>>>>>>> Maybe you used the wrong temperature? My Weller is running at >>>>>>>>>>> 640F >>>>>>>>>>> right now. >>>>>>>>>> Most 'no-clean' hand operations I ever saw left the >>>>>>>>>> perfectly formed >>>>>>>>>> solder joint encapsulated in a thin flux film. Are you sure >>>>>>>>>> that you are >>>>>>>>>> not just too old or too non-detail oriented to 'see' it, even >>>>>>>>>> though it >>>>>>>>>> is there? >>>>>>>>>> >>>>>>>>>> The flux does not evaporate, and is, by design, meant to >>>>>>>>>> remain, so it >>>>>>>>>> *has* to be there... literally. >>>>>>>>> Ok, but it hasn't corroded or otherwise tainted one lone solder >>>>>>>>> joint >>>>>>>>> in years. If it does cause a failure 300 years down the road I >>>>>>>>> think I >>>>>>>>> could live with that :-) >>>>>>>> We use it for everything, never had a problem either. >>>>>>>> >>>>>>>> I take "no-clean" to mean "do not clean". I have heard (here) of >>>>>>>> problems when cleaning is attempted, the insulating component is >>>>>>>> washed >>>>>>>> away leaving an ionic residue which can absorb water and >>>>>>>> conduct. Or >>>>>>>> something. >>>>>>>> >>>>>>> Even then I had no problems. Many times in my lab I lash up jigs, >>>>>>> on Monday for example a tester to run transformers at 50Hz, 60Hz, >>>>>>> 400Hz or wherever. That stuff gets a beating over time, alligator >>>>>>> clips are attached to soldered areas over and over again so >>>>>>> things become scraped. Never a problem. >>>>>> Try it for high impedance circuits >> 1E7 Ohms. >>>>> >>>>> I avoid that wherever possible. If needed it's best to work with >>>>> guard rings. >>>> >>>> So do i, still, i did enough stuff at 1E8 Ohms and some much higher >>>> (1E12 Ohms) to have a real respect for doing that routinely. >>> >>> >>> Ok, but that's a specialty area. There will always be specialty areas >>> where normal design techniques aren't good enough. All I am saying is >>> that IME No-Clean is quite ok for all the regular designs I did. And >>> this has included some hardcore low-noise stuff. >>> >> >> No clean has no pb at all with low noise designs since low noise >> designs have pretty low impedances. >> That's high impedance low level that's tough. >> >> The small sensors I'm working on have 0603 1G fb resistors plus caps, >> and have to works for decades at elevated temperature (possibly up to >> 125C) and the very last one has 0402 100M resistors and caps. >> > > Well, that _is_ specialty stuff. Other than guard-ringed input circuitry > I can't remember ever having gone above 18M. Because anything above 18M > can become a purchasing problem. Also, higher-Z nodes will need to be > under some sort of coating or it'll all fall apart in high humidity > places. Puerto Rico, for example. > > >> No clean is a no-no... >> > > So how do you clean the flux residue from underneath that 0402 then? > Specially trained microbes? Watch out that they don't form a union some > day :-) > Done inhouse by my customer because the board stuffer can't get it right (no pb with this, it's specialty as you said). Several pass of US cleaning with some tricks I can't disclose. -- Thanks, Fred. |