Hi guys, Followed Tom and Gerald's suggestions, I tried it again by 800F with the lead-free solder. This time everything go well just like the tutorials and it works now!
Many thanks to all of you! - Claud On Tuesday, March 24, 2015 at 7:27:37 AM UTC-7, Gerald wrote: > > Lead free. High temp neede to melt it. > > Gerald > > On Tue, Mar 24, 2015 at 9:23 AM, Harvey White <[email protected] > <javascript:>> wrote: > >> On Tue, 24 Mar 2015 00:03:54 -0700 (PDT), you wrote: >> >> >Hi Harvery, >> > >> >700 dgree can melt lead-free solder *directly* very well -- that's how I >> >adhere a layer of solder to connector pins. Then I put connector on top >> of >> >P2 on the board and heat the pins for making the solder melt and connect >> >joint just like the video. >> >> This is called (or was) "sweat soldering" it does work, but may not >> be the best at times. No problem though. >> >> >But the solder between pins and P2 won't melt >> >> What may be happening is that the solder on P2 is protected by a layer >> of something, either oxide, or solder mask, or the like. I'd take a >> small xacto knife or equivalent, and gently scratch one of the pads to >> clean the surface. You want to stay in the plating area (assuming >> that this is solder plated. Did you use flux? Liquid flux is >> generally very useful in this kind of situation. You should be able >> to melt the solder and let it flow onto the board land (the contact >> area), without a pin there. If the solder just beads up, then you're >> not getting any heat transfer to the pad, or the pad is protected. >> >> I've had badly oxidized pads not take solder, and some plating on >> boards will not accept solder (nickel, if I remember it). In that >> case, some very gentle abrasion of the plating may expose the copper. >> This is a crude solution, though. You could also try cleaning the >> pads with a pencil eraser. It's quite abrasive and should not be used >> for edge contacts (it will remove gold plating very easily). >> >> >and none of it will adhere to the P2 even I heated 4-6 seconds in 700 >> >degree. Note that I cleaned the solder iron with tip tinner and brass >> >sponge before this step. >> >> Generally, what you do is avoid the tip tinner unless you're losing >> the tinning on the tip (solder won't adhere to the tip itself). I >> normally don't use it or need it. Then you add solder, just a bit, to >> the tip, use the sponge to clean it (and any oxides) off, then solder. >> You can add a tiny bit of solder to the tip, which forms a tiny drop >> there, and when put to a joint, will help heat transfer. >> >> The steps are generally 1) clean the tip, 2) do the joint, 3) put the >> iron back (it doesn't need to be cleaned at this point, the excess >> solder actually tends to protect the tip). >> >> > >> >Another way is just like you said (hope my understanding is correct) to >> >heat some solder and let it flow to the pin and wet the joint. I tried. >> But >> >the solder flow won't adhere to the P2 but just accumulated on the pin >> till >> >bridge with adjacent pin. >> >> Then there's something there that the solder won't wet. There might >> be a coating over the connector. >> > >> >Do you have any comment on this situation? >> > >> Just did, it's an odd situation, since most of the boards are >> manufactured to enable you to solder to selected areas, and the pads >> for such a connector site would be ready to solder to. >> >> Mine's a circuitco board, so I can't help with trying. >> >> If you have some leaded solder, I'd try that. I'd also get a tube of >> flux, you want the Kester RMA flux, which would be available at places >> like Mouser or Digikey or Avnet (not sure about Jameco). This flux is >> quite helpful for doing surface mount soldering (I do that a lot...). >> >> Harvey >> >> >Thank you so much! >> > >> >On Monday, March 23, 2015 at 8:37:46 PM UTC-7, Harvey White wrote: >> >> >> >> On Mon, 23 Mar 2015 19:46:19 -0700 (PDT), you wrote: >> >> >> >> >Thank you Tom and Harvey! I'll try again with higher temperature (800 >> or >> >> >even more higher till it melts) as well as adopt Harvey's suggestions. >> >> >Result will be reported in this thread. >> >> >> >> Ah, no, more temperature is not always what's needed. >> >> >> >> Too cold and it never melts. Too hot and it damages the board and >> >> what you're soldering. For leaded solder, 600 degrees is fine for >> >> small sensitive parts, 700 degrees for standard parts, and you almost >> >> never need 800 degrees. >> >> >> >> Try a few joints with the solder and just solder a few pieces of wire >> >> together, say 22 gauge or so. That gives you the practice you may >> >> need for lead free solder (behaves differently). >> >> >> >> >> >> > >> >> >I used lead-free .022 in 700 degree. Temperature is one of a few >> factors >> >> I >> >> >haven't adjusted in those attempts for not damaging the board. >> >> > >> >> 800 degrees is a bit too hot. There's a bit of a touch to it, as to >> >> how to solder and how not to. You want the solder to "flow" and to >> >> "wet" the joint as if it were water. >> >> >> >> I'd see what the melting point of your particular lead free solder is, >> >> and then see what the recommended iron temperature is as well. >> >> >> >> Harvey >> >> >> >> >Also I've found CircuitCo version in Jameco Electronics. >> >> > >> >> >On Monday, March 23, 2015 at 5:25:56 PM UTC-7, Harvey White wrote: >> >> >> >> >> >> On Mon, 23 Mar 2015 16:56:58 -0700 (PDT), you wrote: >> >> >> >> >> >> > >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> > >> >> >> >I just checked my settings. I have my iron set to 430C / 806 F and >> >> >> haven't >> >> >> >touched it since soldering that JTAG connector last week. Yeah. >> So >> >> very >> >> >> >hot. Don't leave it sit on the board at that temp. I figured a fast >> >> dab >> >> >> at >> >> >> >high temp is better than letting it sit at lower temp though. >> Maybe >> >> I'm >> >> >> >wrong. Like I said, I'm not a pro with the soldering, but it worked >> >> for >> >> >> me >> >> >> >on the first try. Before I got my nice soldering iron I had >> problems >> >> >> >getting connectors soldered onto another board because my iron >> wasn't >> >> >> >getting hot enough. I don't have that problem anymore. :-) >> >> >> > >> >> >> >My solder is Kester 44 Rosin Core Solder 60/40 .031. >> >> >> >> >> >> OK, several things here: >> >> >> >> >> >> 1) 63/37 is eutectic for solder, and has the lowest melting point. >> It >> >> >> goes from liquid to solid and does not have a plastic phase (good). >> >> >> >> >> >> 2) 700 degrees is normal, and 600 is used for sensitive devices. >> >> >> >> >> >> 3) the amount of power that your tip can deliver (not necessarily >> the >> >> >> temperature) determines the size of the joint you can heat and >> >> >> successfully solder >> >> >> >> >> >> 4) clean is the key, a freshly tinned tip (clean and can transfer >> heat >> >> >> well) is much better than an oxidized tip. >> >> >> >> >> >> 5) better to use a brass sponge than a wet one. Less thermal shock >> to >> >> >> the tip. >> >> >> >> >> >> Harvey >> >> >> >> >> >> > >> >> >> >Tom Olenik >> >> >> >> >> >> >> >> >> >> >> >> -- >> For more options, visit http://beagleboard.org/discuss >> --- >> You received this message because you are subscribed to the Google Groups >> "BeagleBoard" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected] <javascript:>. >> For more options, visit https://groups.google.com/d/optout. >> > > > > -- > Gerald > > [email protected] <javascript:> > http://beagleboard.org/ > http://circuitco.com/support/ > -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
