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2006-09-03 by jdizzlemynizzal
A datasheet that includes footprints and dimensions for the US8 package, http://www.fairchildsemi.com/ds/NC/NC7WZ08.pdf , this is incredibly small, its basically about the size of an SOT-23 but with 8 pins. Some tips on soldering laughably small SMD components like the US8 would be appreciated.
2006-09-03 by Volkan Sahin
For the fine pitch packages I am soldering one corner of chip and then doing fine alignment by checking opposite corner. If it is ok then I am soldering this corner also. As a next step I am using to much solder for all pins and short circuiting all pins of the chip by solder, after than I am removing excess solder by solder wick. I am also checking shorts by magnifier and then I am cleaning the board by acetone or alcohol. By this method I could be able to solder down to 0.35mm fine pitch SMD components. Volkan --- jdizzlemynizzal <jdizzlemynizzal@...> wrote:
> A datasheet that includes footprints and dimensions > for the US8 > package, > http://www.fairchildsemi.com/ds/NC/NC7WZ08.pdf , > this is > incredibly small, its basically about the size of an > SOT-23 but with 8 > pins. Some tips on soldering laughably small SMD > components like the > US8 would be appreciated. > > > > >
2006-09-03 by william.kroyer@kilroysprojects.net
What I do with those really small smt packages is first tin the legs and then the pads. Then I get it lined up and just hit two catty-corner pins (ie pin 4 and pin 8) to hold it in place. Then I just go down the line and hit each leg with a bit of heat. I find that with those small packages the solder used to tin the legs and pads is usually enough to get a good clean solder joint.
----- Original Message ----- From: jdizzlemynizzal To: Homebrew_PCBs@yahoogroups.com Sent: Sunday, September 03, 2006 1:10 AM Subject: [Homebrew_PCBs] Anyone have experience on soldering US8 packages, with a fine tip solder iron? A datasheet that includes footprints and dimensions for the US8 package, http://www.fairchildsemi.com/ds/NC/NC7WZ08.pdf , this is incredibly small, its basically about the size of an SOT-23 but with 8 pins. Some tips on soldering laughably small SMD components like the US8 would be appreciated. [Non-text portions of this message have been removed]
2006-09-03 by Stefan Trethan
On Sun, 03 Sep 2006 07:10:50 +0200, jdizzlemynizzal <jdizzlemynizzal@...> wrote: > A datasheet that includes footprints and dimensions for the US8 > package, http://www.fairchildsemi.com/ds/NC/NC7WZ08.pdf , this is > incredibly small, its basically about the size of an SOT-23 but with 8 > pins. Some tips on soldering laughably small SMD components like the > US8 would be appreciated. Use paste and reflow it but you can still solder that with an iron and a magnifier in a pinch. The micropak will only work with paste or pre-tinning and reflow. ST
2006-09-03 by Leon Heller
----- Original Message -----
From: "jdizzlemynizzal" <jdizzlemynizzal@...> To: <Homebrew_PCBs@yahoogroups.com> Sent: Sunday, September 03, 2006 6:10 AM Subject: [Homebrew_PCBs] Anyone have experience on soldering US8 packages, with a fine tip solder iron? >A datasheet that includes footprints and dimensions for the US8 > package, http://www.fairchildsemi.com/ds/NC/NC7WZ08.pdf , this is > incredibly small, its basically about the size of an SOT-23 but with 8 > pins. Some tips on soldering laughably small SMD components like the > US8 would be appreciated. I've soldered a lot of 0.5 mm lead-pitch devices. I use a microscope to tack down two leads on opposite corners, and drag-solder the leads, using plenty of flux. With a small device like that I might solder the leads individually. Leon
2006-09-03 by derekhawkins
>Use paste and reflow it Waste of time for an IC like that unless you're reflowing all components. And reflowing all components (a whole board) without soldermask is a disaster waiting to happen. --- In Homebrew_PCBs@yahoogroups.com, "Stefan Trethan" <stefan_trethan@...> wrote: >
2006-09-03 by Stefan Trethan
On Sun, 03 Sep 2006 15:04:31 +0200, derekhawkins <eldata@...> wrote: >> Use paste and reflow it > Waste of time for an IC like that unless you're reflowing all > components. And reflowing all components (a whole board) without > soldermask is a disaster waiting to happen. That's just hot air. (forgive the pun). Even a single IC with 8 pins is quicker reflow-soldered than iron soldered. Reflowing without soldermask is no problem at all as long as you understand what you are doing and observe some rules when routing the board. As soon as you have a thermal pad or leadless package the iron is out anyway... I wouldn't recommend anyone to buy a hot air tool to reflow a single IC if it can be iron soldered as well, but if you have the tools anyway there is no reason at all not to solder these things like they were meant to be soldered. ST
2006-09-03 by derekhawkins
>That's just hot air Geez, let me guess, you've hot air reflowed a few SMD ICs in your time. Probably the only SMD component on the entire board. Otherwise, it would be interesting to hear you tackling more than one of these US8 packages in close proximity on the board using hot air. --- In Homebrew_PCBs@yahoogroups.com, "Stefan Trethan" <stefan_trethan@...> wrote: >
2006-09-03 by Stefan Trethan
On Sun, 03 Sep 2006 15:59:04 +0200, derekhawkins <eldata@...> wrote: > > Geez, let me guess, you've hot air reflowed a few SMD ICs in your > time. Probably the only SMD component on the entire board. Otherwise, > it would be interesting to hear you tackling more than one of these > US8 packages in close proximity on the board using hot air. Can you re-phrase that so i get what you are saying? ST
2006-09-03 by derekhawkins
>Some tips on soldering laughably small SMD components like the >US8 would be appreciated. Soldering may be the least of your worries if you're using TT. Spacing between pads is less than .008". --- In Homebrew_PCBs@yahoogroups.com, "jdizzlemynizzal" <jdizzlemynizzal@...> wrote: >
2006-09-03 by Stefan Trethan
On Sun, 03 Sep 2006 16:07:11 +0200, derekhawkins <eldata@...> wrote: > > Soldering may be the least of your worries if you're using TT. Spacing > between pads is less than .008". 0.5mm pitch is no probem with TT, using a 600dpi printer. But it's best to make the pads slightly narrower than you'd usually make them, since the toner spreads a little. How much depends, best experiment. Now what is a problem on homebrew boards is getting signals to and fro, without real vias... I'd much prefer if they didn't make them parts so small, but what can you do? ST
2006-09-03 by Robert Hedan
> -----Message d'origine----- > De : Homebrew_PCBs@yahoogroups.com > [mailto:Homebrew_PCBs@yahoogroups.com] De la part de derekhawkins > Envoyé : septembre 3 2006 09:59 > À : Homebrew_PCBs@yahoogroups.com > Objet : [Homebrew_PCBs] Re: Anyone have experience on > soldering US8 packages, with a fine tip solder iron? > > > Geez, let me guess, you've hot air reflowed a few SMD ICs in your > time. Probably the only SMD component on the entire board. Otherwise, > it would be interesting to hear you tackling more than one of these > US8 packages in close proximity on the board using hot air. > I have a hot air tool and used it infrequently so far. But the few times I did use it, the tool was very helpful tackling ICs like these. Proximity is relative, if the next IC is 100 mil away, yes, you are going to have some problem. But that's not the case on any of my boards, I leave enough room 'cause I end up with extra traces all over the place anyways in trying to limit vias. Tinning the legs and pads is critical, so is solder flux. Patience, a decent mag lense and tweezers come in very handy. Robert :)
2006-09-03 by jdizzlemynizzal
--- In Homebrew_PCBs@yahoogroups.com, "derekhawkins" <eldata@...> wrote: > > >That's just hot air > > Geez, let me guess, you've hot air reflowed a few SMD ICs in your > time. Probably the only SMD component on the entire board. Otherwise, > it would be interesting to hear you tackling more than one of these > US8 packages in close proximity on the board using hot air. > > --- In Homebrew_PCBs@yahoogroups.com, "Stefan Trethan" > <stefan_trethan@> wrote: > > > What is the procedure in Hot Air Reflowing?
2006-09-03 by Stefan Trethan
On Sun, 03 Sep 2006 17:20:05 +0200, Robert Hedan <robert.hedan@...> wrote: > Proximity is > relative, if the next IC is 100 mil away, yes, you are going to have some > problem. But that's not the case on any of my boards, I leave enough > room > 'cause I end up with extra traces all over the place anyways in trying to > limit vias. You can use cardboard or PCB pieces or something to shield sensitive components like 'lytics or plastic parts that are not meant to withstand reflow. There is no harm in warming up surrounding ICs that were meant for reflow anyway. ST
2006-09-03 by Leon Heller
----- Original Message -----
From: "Stefan Trethan" <stefan_trethan@...> To: <Homebrew_PCBs@yahoogroups.com> Sent: Sunday, September 03, 2006 3:05 PM Subject: Re: [Homebrew_PCBs] Re: Anyone have experience on soldering US8 packages, with a fine tip solder iron? > On Sun, 03 Sep 2006 15:59:04 +0200, derekhawkins <eldata@...> wrote: > >> >> Geez, let me guess, you've hot air reflowed a few SMD ICs in your >> time. Probably the only SMD component on the entire board. Otherwise, >> it would be interesting to hear you tackling more than one of these >> US8 packages in close proximity on the board using hot air. > > > Can you re-phrase that so i get what you are saying? He wants to know if you could solder one of those little parts with hot air that is situated near other ones. Presumably he is concerned about the hot air on the chip being soldered desoldering those near it. Leon -- Leon Heller, G1HSM Suzuki SV1000S motorcycle leon.heller@... http://www.geocities.com/leon_heller
2006-09-03 by Stefan Trethan
On Sun, 03 Sep 2006 17:42:40 +0200, Leon Heller <leon.heller@...> wrote: > > He wants to know if you could solder one of those little parts with hot > air > that is situated near other ones. Presumably he is concerned about the > hot > air on the chip being soldered desoldering those near it. > Leon So what - they'll just solidify again. It depends on what nozzle you use. With the oven you can do an entire board. With the hot air gun without nozzle you can also do entire boards by moving it about. With a 1cm nozzle you can nicely do individual ICs, but surrounding ICs will be affected, i'd guess maybe a 3cm diameter circle that could potentially melt. With the tiny hot air pencil on the soldering iron i can take out or solder individual 2-pin chips without the others around melting, or very small ics if i move about over all the leads in a periodic fashion. It's not really been much of a worry for me with surrounding components. But then i don't put anything sensitive where it would be a problem on my boards. I've definitely desoldered more chip components accidentally when trying to butcher around with the soldering iron. People sometimes have the misconception that things will fly away in the airstream. That is not happening if the the volume/speed is low enough. I sometimes do that with the hot air pencil though, blast components off boards, that's good fun and lets you know when they are loose. ;-) ST
2006-09-03 by derekhawkins
>There is no harm in warming up surrounding ICs that were meant for >reflow anyway. Well, with small SMDs and high density placement, trust me, you wouldn't want to use a hot air tool for soldering at all. Even when desoldering, where the tool is most useful, there are issues with unintentionally removing surrounding SMDs. Yes, you can speculate all you want but it's quite obvious that your SMD soldering experience is limited. --- In Homebrew_PCBs@yahoogroups.com, "Stefan Trethan" <stefan_trethan@...> wrote: >
2006-09-03 by Stefan Trethan
On Sun, 03 Sep 2006 17:36:39 +0200, jdizzlemynizzal <jdizzlemynizzal@...> wrote: > > What is the procedure in Hot Air Reflowing? You apply solder and flux in some form, usually a paste with small solder particles in it, but in a pinch you can also simply tin one or both surfaces. Then you position the component close to where it should end up. Next you re-flow the solder by melting it in some way (therefore the name), with hot air, an oven, a hotplate, or even infrared light. This forms nice solder joints almost magically, surface tension making sure the solder goes where it is wanted and the parts align properly. Then you let things cool, clean of the flux if needed, and you are done. The really big advantage is undoubtedly that it is very efficient if you have many components, but with SMD it is also the most convenient way to do rework etc.. ST
2006-09-03 by Stefan Trethan
On Sun, 03 Sep 2006 18:20:48 +0200, derekhawkins <eldata@...> wrote: > Well, with small SMDs and high density placement, trust me, you > wouldn't want to use a hot air tool for soldering at all. Even when > desoldering, where the tool is most useful, there are issues with > unintentionally removing surrounding SMDs. Yes, you can speculate all > you want but it's quite obvious that your SMD soldering experience is > limited. You must use too much airflow or something. I have no trouble at all to take off individual components of something like a densely populated harddrive, without disturbing surrounding parts, with just the large heat gun even without any nozzle at all. Yes, others will melt, but why should they be removed? Just dont touch them, grab the one you want to replace with tweezers and take it straight up. I really don't think there are boards where you can't even get tweezers in between components. As far as i know the people working on mobile phones use hot air too... I've SMD soldering tweezers as well, but compared to hot air they are a PITA, and short of special iron tips i see no other way to remove smd components. soldering is of course even easier since you do not have to touch the component when everything is hot to remove it. So if you make such claims, maybe support them with industry examples, examples for hot air rework there are plenty.... ST
2006-09-03 by derekhawkins
>With the oven you can do an entire board. We all know that. >With the hot air gun without nozzle you can also do entire boards >by moving it about. Moving it about where? The bottom side of the board perhaps. --- In Homebrew_PCBs@yahoogroups.com, "Stefan Trethan" <stefan_trethan@...> wrote: >
2006-09-03 by Stefan Trethan
On Sun, 03 Sep 2006 19:06:33 +0200, derekhawkins <eldata@...> wrote: > > >> With the hot air gun without nozzle you can also do entire boards >> by moving it about. > Moving it about where? The bottom side of the board perhaps. No from the top. Moving it in like an S shaped pattern, slowly. Imagine it a bit like painting with a spray gun. Makes only sense with smaller boards (say no longer than 10cm), but it works so well it has discouraged me from building that oven until now. ST