lead free solder
in [Repair]
|
From: Jeffrey D Angus on 25 May 2010 11:23 Smitty Two wrote: > In article <fmmck-B55AAB.20291624052010(a)5ad64b5e.bb.sky.com>, > Fred McKenzie <fmmck(a)aol.com> wrote: > >> One problem occurs if you use leaded solder on surface-mounted >> components. Lead amalgamates with the silver that is "fired" onto these >> components, ruining their electrical connection. > > Huh? What the devil are you talking about? This is not new. Tektronix used to include a bit of silver bearing solder with their scopes so you wouldn't ruin the plated ceramic terminal strips if you changed out parts. Jeff -- �Egotism is the anesthetic that dulls the pain of stupidity.� Frank Leahy, Head coach, Notre Dame 1941-1954 http://www.stay-connect.com
From: David Nebenzahl on 25 May 2010 13:28 On 5/25/2010 8:23 AM Jeffrey D Angus spake thus: > Smitty Two wrote: > >> In article <fmmck-B55AAB.20291624052010(a)5ad64b5e.bb.sky.com>, >> Fred McKenzie <fmmck(a)aol.com> wrote: >> >>> One problem occurs if you use leaded solder on surface-mounted >>> components. Lead amalgamates with the silver that is "fired" onto these >>> components, ruining their electrical connection. >> >> Huh? What the devil are you talking about? > > This is not new. Tektronix used to include a bit of silver bearing > solder with their scopes so you wouldn't ruin the plated ceramic > terminal strips if you changed out parts. Well, it was silver-*bearing*: still mixed with lead, no? (I assume this is pre-RoHS.) -- The fashion in killing has an insouciant, flirty style this spring, with the flaunting of well-defined muscle, wrapped in flags. - Comment from an article on Antiwar.com (http://antiwar.com)
From: Smitty Two on 25 May 2010 13:30 In article <htgq0r0a43(a)news7.newsguy.com>, Jeffrey D Angus <jangus(a)suddenlink.net> wrote: > Smitty Two wrote: > > In article <fmmck-B55AAB.20291624052010(a)5ad64b5e.bb.sky.com>, > > Fred McKenzie <fmmck(a)aol.com> wrote: > > > >> One problem occurs if you use leaded solder on surface-mounted > >> components. Lead amalgamates with the silver that is "fired" onto these > >> components, ruining their electrical connection. > > > > Huh? What the devil are you talking about? > > This is not new. Tektronix used to include a bit of silver bearing > solder with their scopes so you wouldn't ruin the plated ceramic > terminal strips if you changed out parts. > > Jeff So adding tin/lead solder to a silver component terminal turns the connection into what, a non-conductive roofing shingle or something? I'm pretty sure I would have heard from a customer or two if the thousands of RoHS components I've soldered with 63/37 weren't conducting electricity.
From: ian field on 25 May 2010 14:00 "Baron" <baron.nospam(a)linuxmaniac.nospam.net> wrote in message news:hth2v2$a0p$1(a)news.eternal-september.org... > Hi Guys, > > Just for the record here's a few pictures of a laptop power socket that > used lead free solder. You can see the erosion caused by poor > electrical conductivity of the joint between the center pin and the > circuit board. The hole was originally plated through but there was > little left of the plating. An open circuit and discharged battery > resulted in a non working machine. > > The images don't show in "ser" check > in "alt.binaries.schematics.electronic" I just got through repairing the accumulation of PC monitors I'd taken out of service because of lead-free solder syndrome. Most people scrap them and buy a new one - not very eco-friendly at all!
From: WangoTango on 25 May 2010 14:29
In article <htgtgd$b6n$1(a)reader1.panix.com>, presence(a)MUNGEpanix.com says... > > Aside from silver plated or specialty parts in an old scope, is there any harm done > in using real solder in a RoHS device? > > Here's an example. > > a resistor mounted through-hole has a bad joint. Normal repair just reheat the joint > and add more solder. No problem. I've reworked a thousand "RoHS" boards with good 'ol 60/40 and have never had a failure of one of MY joints, or any problems related to them. The stupid part of all of this is, just how are you going to know EXACTLY which lead free solder was used to begin with? There a a lot of formulations, from good 'ol SAC (Tin, silver, copper) to a bunch of alloys with all kinds of weird stuff in them. So, if you grab a spool of SAC and the OEM used a bismuth or zinc alloy, what is going to happen? I just clean up as much of the original solder as possible with solder wick and put down 60/40 and forget about it. I might also add, that we have mixed RoHS and non-RoHS parts for years with no failures due to the tin/lead solder. In fact UPS has destroyed more boards by running them over than any other failure mechanism. |