X-Authentication-Warning: delorie.com: mail set sender to geda-user-bounces using -f X-Recipient: geda-user AT delorie DOT com Message-ID: <50065479.8060307@keensupport.net> Date: Tue, 17 Jul 2012 23:15:21 -0700 From: Joe Knapp Organization: Keen Support Services, LLC User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:13.0) Gecko/20120615 Thunderbird/13.0.1 MIME-Version: 1.0 To: geda-user AT delorie DOT com Subject: Re: [geda-user] Soldering problems References: <500423C2 DOT 2030201 AT estechnical DOT co DOT uk> <500474CA DOT 5020505 AT estechnical DOT co DOT uk> In-Reply-To: <500474CA.5020505@estechnical.co.uk> Content-Type: multipart/alternative; boundary="------------060407050201000209090801" Reply-To: geda-user AT delorie DOT com This is a multi-part message in MIME format. --------------060407050201000209090801 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit I would like to add that water soluble flux can cause issues also. It can be conductive. I have seen ~50K Ohms between pads on SMT devices due to organic water soluble not being properly cleaned. This is a real issue with small pitch LDOs or LDOs with power pads. This can affect the set point of the adjustable LDO and cause un-desirable voltages. Good luck, Joe On 07/16/2012 01:08 PM, Ed Simmons wrote: > On 16/07/12 19:41, Rob Butts wrote: >> Thanks Ed! >> >> That is exactly what is happening. >> >> On Mon, Jul 16, 2012 at 10:22 AM, Ed Simmons > > wrote: >> >> >> We had this issue when using the damp sponge to clean the iron. >> Switching to a brass spiral cleaner helped keep the iron clean, >> and when it gets really dull and refuses to re-tin, use something >> like this: >> http://uk.rs-online.com/web/p/soldering-iron-tips-accessories/0226287/ >> - this brings up a good-as-new shine on the bit. >> >> Hope that helps. >> >> Ed >> >> > > No worries - please make sure you've got good fume extraction - it's > nasty! > > Are you using no-clean flux? It's really difficult to deal with since > most no-clean flux contains a plasticiser to halt any reaction from > the small remaining amount of possibly active flux after it's been > through a soldering cycle. This gets all over the bit of the iron and > quenching the heat out of the bit with a sponge only makes it stick on > harder. Reworking reflowed boards is such a pain (not to mention ugly > and obvious) we're switching to water soluble fluxes so that we can > actually clean it at the end. Such are the trials of short-run > electronics. :-| > > If it spits while you feed the solder into the joints, the iron is > probably a bit too hot, but this is hard to avoid without preheating > the whole PCB until it's really toasty. On multilayer boards with pins > connected to the ground-plane this is almost essential in order to be > able to solder at anywhere near the correct temperature. -- Keen Support Services, LLC http://keensupport.net --------------060407050201000209090801 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit I would like to add that water soluble flux can cause issues also. It can be conductive. I have seen ~50K Ohms between pads on SMT devices due to organic water soluble not being properly cleaned. This is a real issue with small pitch LDOs or LDOs with power pads. This can affect the set point of the adjustable LDO and cause un-desirable voltages.

Good luck,

Joe

On 07/16/2012 01:08 PM, Ed Simmons wrote:

On 16/07/12 19:41, Rob Butts wrote:

Thanks Ed!

That is exactly what is happening.

On Mon, Jul 16, 2012 at 10:22 AM, Ed Simmons <ed AT estechnical DOT co DOT uk> wrote:

We had this issue when using the damp sponge to clean the iron. Switching to a brass spiral cleaner helped keep the iron clean, and when it gets really dull and refuses to re-tin, use something like this: http://uk.rs-online.com/web/p/soldering-iron-tips-accessories/0226287/ - this brings up a good-as-new shine on the bit.

Hope that helps.

Ed

No worries - please make sure you've got good fume extraction - it's nasty!

Are you using no-clean flux? It's really difficult to deal with since most no-clean flux contains a plasticiser to halt any reaction from the small remaining amount of possibly active flux after it's been through a soldering cycle. This gets all over the bit of the iron and quenching the heat out of the bit with a sponge only makes it stick on harder. Reworking reflowed boards is such a pain (not to mention ugly and obvious) we're switching to water soluble fluxes so that we can actually clean it at the end. Such are the trials of short-run electronics. :-|

If it spits while you feed the solder into the joints, the iron is probably a bit too hot, but this is hard to avoid without preheating the whole PCB until it's really toasty. On multilayer boards with pins connected to the ground-plane this is almost essential in order to be able to solder at anywhere near the correct temperature.

-- 
Keen Support Services, LLC
http://keensupport.net

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