When doing solder touchup, adding a little solder flux to the joint first will work wonders for reflowing the solder and avoid possible cold solder joints. It probably would have fixed the bridging too during the touchup.
THE best video I've seen - explains all steps, adds lots of tips, just excellent. It takes some of the "fear" away from surface mount. Personally, I might have slipped some heat-shrink tubing over the too-coarse needle, and shrink it to have a finer applicator, but the fact he did it as is and it worked, is wonderful.
...and per a later comment, the heat-shrink could be cut at an angle to dispense somewhat downward, I think. Finding thin enough heat-shrink might be a problem. All this is theoretical.
Kevin, thanks for the video. This is the first time I have seen surface mounting done and between watching the video and reading the comments I have learned a lot. It has made me feel that "Yeah, I can learn to do that".
When doing it without a stencil, just dab the solder paste to the components, Use a toothpick to wipe off any excess if need be, then place the parts on the board with your tweezers
I don't know if someone has already written this down but I'm going to share it anyway. If you want to use the solder paste syringe to manually dispense, then for the very fine pitch pads you could buy from your local pharmacy (if they are available) empty fine-tipped syringes (the insuline injection type) and use them as a kind of scoop. You dump some quantity (paste) somewhere off the board and you use the fine-tipped syringe to pick up a small amount of solder paste each time to lay on each pad. The reason I am suggesting a fine-tipped syringe and not a needle for example, is because the tip of the syringe is an diagonally cut tube which means it is concavely shaped ( kinda like a spoon) on the one side which can hold some paste more effectively than just something cone shaped. It is a bit time consuming but it is a lot better than bridges due to excess solder and you can save yourself some trouble from having to use the hot iron and the wick. Sometimes using the wick removes more solder than it should, you cannot exactly control it. The manual dispensing way presented in this video is fine if you want to go for it. I just wanted to share some of my experience, so no trolling please. PS: Also Kevin Darrah, you might wanna start considering some hot plates for properly heating up and re-flowing for your assemblies (provided the boards assembled are one-sided and small enough to fit on the surface of the plate). Some components (and yes that includes ceramic caps and resistors) DO NOT like thermal shock as you probably know. A hot plate can be a cheap (kinda) solution to that. Alright that's it, I'm out. Bye!
Thanks for sharing. Just to add some point of benefit, when you paste the PCB by hand and you make a mess by bridging the pads, I would not recommend to use the iron for cleaning it as you did it here, rather run some flux over those pads, change the tip of the iron into a flat blade that covers all the pads of one side of the chip (they come in different sizes) then simply wipe them all outwardly, away form the chip, you'll notice the pads nicely and evenly soldered with no bridging at all. And finally, don't forget the golden rule, ESD protection. Carry on the good work.
Wow, Kevin you are indeed good at this. As an old school engineer I remember when we first rolled out SMD designs in the 80's thinking, well this is the end of the garage tinkerer. Obviously I was wrong. What impresses me most is the number of connections being made and the fact that you were able to make good ones without shorts/opens the first time. Keep it up. Maybe an old school guy like me will be motivated to give it a try despite the fact that my garage is full of old PIH stuff. :)
Great video! I don't know if anyone else mentioned this, but in addition to the capillary action, it's the surface tension of the molten solder that pulls the parts into alignment with the pads.
Watching this... one tip is you don't really want to crank up the air temperature that high. I assume you are using leaded solder paste. You want as much airflow as is practical and as little temperature as is needed to do proper reflow. With high temperature air and low air flow you are creating large temperature gradients and this is also damaging to components. You can have the top of your component be very hot (directly to very hot 400C air) but the pads still relatively cool. High air flow tends to equalize and spread temperature much better which means you can use cooler air flow. Also try to soak the board and components in hot air in lower temperature before you get to actual reflow temperature. This is what would usually happen in professional reflow oven btw. If you preheat the board the gradients will be less and the whole process will be more forgiving. The way I would determine is I would crank up the cool air until parts start flying away, then reduce it a bit. I would then crank up temperature to see when it takes few seconds to start reflow, not too fast, not too slow. I would soak the board from bit further away and when I'm satisfied I would close in with the gun and do the reflow itself.
Thanks! Very helpful. Especially useful that you showed best case scenario with template mask and worst case sloppy hobby scenario with hand applied solder paste. Both worked! Great that you showed how to clean up a sloppy job including solder bridges. Good job! Nice video!
Great video but I have to correct you on something. The capillary action only happens between the flat bottom of the pins and the flat pad because it's a narrow space and capillary action is the ability of a liquid to flow in narrow spaces without the assistance of, or even in opposition to, external forces like gravity. What you mentioned about the solder separating and grouping around the pins is due to surface tension not capillary action. Surface tension is the elastic tendency of a fluid surface which makes it acquire the least surface area possible so droplets separate and group around the pins cleaning up the spaces between pins of solder.
Great comment, but I have to correct you on something. "Capillary" applies to narrow tubes. Surface tension is a more general term, and capillary action relies entirely on surface tension. Liquids forming into droplets is another phenomenon that also relies on surface tension, in the case where a liquid adheres to itself more readily that to any adjacent surface or material, or in a vacuum. Also "ability of a liquid" implies that the nature of the liquid is all that matters. The nature of the surface is just as important, as evidenced by the failure of solder to take on some surfaces. The solder will adhere if energy state of the surface in contact with the solder is lower than that of the surface in contact with the air. Systems tend to change to lower energy states when possible, sometimes needing a "push" in this case the application of heat in the presence of flux.
I usually center the component, then add solder paste. When I was taught, I was told that they are very small solder balls inside the paste. So with that under the flat surface of your component, it allows the potential of that component moving around. It makes sense to me, and its the only way I've done it. Also, you don't really need to add the solder paste directly on the pads, just get it close. When the solder reaches melting temp it'll walk right up your pad/ lead. Downside is if your hot air jet tweaks when you're running it back and forth, you create a big potential for solder bridges. So steady hands are always nice lol. However, I suppose at the end of the day multi leaded devices are just generally synonymous with solder bridges. But you know what they say, different strokes for different folks. Just a different outlook on other methods. Great video man, thanks for making it!
Good video. I like that you've demonstrated both methods and how to fix bridges. Also, thank you for providing the links to the tools and parts (reflow station and the PCB service provider).
Take a small blob of blu-tak, shape it into a point, and stick it to the end of a pencil or empty pen. Makes a very accurate pick and place tool! The only thing it doesn't have is a release, so that's where your tweezers come in: touch tweezers to top of part, withdraw pick tool. The sharpness of the point on the blu-tak can be adapted for different part sizes, e.g. blunt for larger parts like your MCU, very sharp for teeny SMD caps and resistors. When blu-tak gets dirty and stops picking up parts, squish and remold - it'll be good as new.
Hey man ! thank yu for the video ... I have been soldering the pins one at a time ... killing my eye sight ... will definitely change to paste method now ... darn .. got all the tools to do it ... could have saved hours of work .... I must have built up more than three four thousand boards bu hand .. thanks again
Very COoL. Best video on SMT "start to finish"... Being a old-school 1w "resister scale dude" I never realized how do'able this was. You've INspired me to downSIZE. BTW.. Really nice (camera) work. Thank you (subscribed, of course:)
Something I have used to fix solder bridging is an iron tip with a flat face. Cleaned well, it allows you to drag the corner of the tip against the board, the face against the tip of the pins. The face of the tip wicks up the excess solder and by dragging the iron across the pins it evens out the solder left behind. Can't remember where I picked the technique up from, but it works in a pinch.
Nice, but in the second method could you not have put the paste on the pins and then put the chip on the board as a way to keep from using too much paste?
Congrats on the patience. :) I've done some small raster soldering by hand in the past and I find it too time consuming. IMO stencil is surely a way to go if you have more than 2-3 boards to do. Cheers!
oh man, that's a good tip! Most of the time I just pick up the stencil when I order boards, so hardly ever do it that way... probably shows in the video :)
The glass PCBs CNLohr makes are really amazing, too. And he doesn't even have through-hole or breadboards, he just goes straight for the SMD, his prototypes are done like a final product lol.
Excellent video. Really cool and makes me feel more comfortable possibly making my own boards with smd components. What I have done before with soldering smd is use really fine braided wire as a wick. I have a large roll of telephone wire that actually used fine braided wire instead of solid. I almost threw it out but if I twist the braid really tight it makes a fine solder wick.
Good job. I never seen anyone use a stencil, but one thing I noticed when you didn't use the stencil was the crystal oscillator shifting position. from my experience, the solder paste has two states. it helps to firmly press down on the component until it reaches the chalky state. shortly thereafter, you can see the little spheres forming and identify the desired state.
try tacking 2 corners of a quad pack. then run a bead of solder paste across the remain legs then heat. It should minimize the solder bridges as well as make it easier to set them in place. Add additional flux when touching up will eliminate the need for the additional heat source, also try using the drag method that's how I was taught.
Good video Kevin but as someone else pointed out it's not the capillary action, it's the soldermask that prevents the solder from attaching itself to anything other than the pads. Well in theory :)
Beautiful! Great video! I don't have a stencil (although after watching this I think I will pay the extra for one next time) but instead apply paste directly using the pointy end of a cocktail stick. Seems to work OK.
It's a great video and thank you!! On my Chuwi Hi9Air tablet, I want to disconnect battery. Manufacturer has two battery poles ending not on a pin connector, so, pole cables are connected on the motherboard soldered. Two pole cables are extremely thin, and also, soldered cables ending are extremely small. I have never seen such a tiny solder. I find it too difficult to unsolder. And if we suppose I unsolder correctly, without any damage, soldering back, e.g. battery replacement, the new battery, I mean the pole cables, is extremely difficult and risky to solder without doing any e.g. bridging damage, and finally damaging completely the motherboard. Would you have something to suggest me in all that? Thank you for your time!
This is a great way to do if you don't have shaky hands. Well I DO!PCBWAY will make ten 100x100mm boards for only $5! Get the red ones they look and work fantastic!
When applying solder paste without the use of a stencil, simply paint the paste on with a small paintbrush. A small amount of paste goes a long way and a thin coating will generally not result in bridging.
Just a thought, but wouldn't you have more control over where the paste goes (when not using a stencil) for the chip pins by applying the paste directly to the pins, and then positioning it on the board?
It is the best practice for large pcb quantities.I think that the pcb manufacturer can make the solder mask stencil also and ship it along with the boards to make the life easier somehow.Otherwise you have to etch it on your own but it worths in massive production and not for few boards.
Use a hotplate and preheat the boards. Then while still on the hotplate use the hot air to flow the solder. Allow the solder to set before removing the pcb. The most questionable but super cheap method is to put the PCB on the hotplate cold, let the heat rise until the solder flows then turn off the power and allow to cool. (Some components don't like this.) Final cleanup with low water isopropyl alcohol (91% or better).
Hi, what kind of resonator did you use for the microcontroller? is it 16MHz ? Can I find that in EAGLE library ? What's the package type for this resonator ? Thank you for video.
havent tried it yet but ive seen an etch done wit flattened pop can with coating removed.... toner transfer and acid peroxide etch. I might give it a shot at some point with riston. Last summer I construsted a vac press exposure box from plexi, low iron glass, 365nm 4.1w led from digi key, vaccum pump from ebay/china, pvc, and weather stripping. Also a vertical bubbler tank for cupric. all i lack at the moment is a tested/confirmed stencil making system. otherwise i can do 8mil on 2oz and enough alignment on dl to do through hole. I figured out that part is easy if i add marks to transparancies and align then glue a strip of preff board between them...makes a hinge that the cc goes between then exposure press box does rest, flip and repeat. I usually drill a hole through template sandwitch and cc so alignment is confirmed on flip. only shit part is i dont want cupric inside and mn has a limited etch season. otherwise a 4x6 dl costs like 4 bucks in consumables.
What temp do you have your soldering iron at when cleaning up the bridges? Also, it doesn't look like you tinned the tip? Or at least wiped off any excess? Thanks for the video...
thanks for the video 2 quick questions. I looked through the comments and didn't see these questions asked. sorry in advance if I missed them. 1 what thickness is the stencil? 2 what is your paste expansion rule? how much larger is your stencil opening than the pad you are applying paste to? thanks in advance.
Where do you get your PCBs made? The link you provided has a PCB Standard Service for $12, 4PCB is good but it forces one to get many boards to have good discounts.
Don't know if this helps - my paste dispenser has a smaller needle and needs a bit of pressure to get it to come out. I found if i held the dispenser quite vertical and gently tap I could control how much comes out to a high-degree. I literally apply paste to each pad one by one this way under the microscope. Then try and drop the components onto the pads so as not to smear the paste and then the heat-gun reflow completes neatly. I'm using lead free too - not sure this matters.
Hey Kevin.. I looked around at your various pages and cant seem to find a place to purchase one of those 328 breakout boards... Are they available for retail yet ??
not quite - going to ship one out (assembled) to all of the patrons first for testing, then if all goes well, I'll get some on order an make them available on mklec.com
Dip a toothpick in the gel type flux and use that to pick up the components. I find you have much more control than using tweezers. Once placed onto solder paste the component will release. Obviously a vacuum pickup with foot pedal is even better.
Great video! I've watched it like a mini-thriller :D P.S. I think that in some cases it's good to check for continuities with a multimeter before testing an assembly.
Great video thanks! I never realised solder paste tubes had that wadding thing, I love that Sharpie! Do you know if tubes of flux have the same thing? Cheers!
Or, if you're me, and really poor, i.e. I can't afford a hot air reflow station, you hold the board six inches over a BIC lighter and hope for the best. :P I've actually soldered a QFN24 that way (a CP2104 USB to UART chip), and yes, it worked.
I can see that the stencil makes a much neater job! Can you make the video again with tighter angles, and a fixed focus, as the camera keeps going out of focus...
you have some very good information that has helped me quit a bit, I'm curious what kind of education you have and are you an engineer for a company. I became interested in computer programming at a young age with a commadore 64 and over the years i have kind of played around with programming. i have a couple of years of electronics engineering, but i never attained a degree. Almost all the electronics knowledge i have is self learned and you appear to have quit a bit of knowledge, so i'm just curious if your knowledge is self taught.
Where do you go for the PCBs? I've played around with arduinos etc for a couple of years but now I've taken on a project to create my own keyboard for my final year university project and I'm thinking of creating some simple through hole PCBs for it. Could use somewhere that can do it for cheap but reliably.
OSH Park does really high quality PCBs. It's $5 per sq. inch for 2 layer boards (silk-screening on both sides too) and that includes 3 copies of your board.
Victor Rivarola I don't think the average 3D printer is even remotely precise enough to make stencils for SMD parts - those IC pins have very close spacing!
Victor Rivarola A 3D printer has a nozzle what, 0.35mm large? No, that's not nearly small enough to *accurately* lay down a stencil for a common QFP with 0.65mm pin pitch. (That is, 0.65mm from the center of one pin to the center of the next.)
![Noob To Max With DRAGON REWORK In Blox Fruits [FULL MOVIE]](http://i.ytimg.com/vi/LnBMOinoOvA/mqdefault.jpg)
When doing solder touchup, adding a little solder flux to the joint first will work wonders for reflowing the solder and avoid possible cold solder joints. It probably would have fixed the bridging too during the touchup.
THE best video I've seen - explains all steps, adds lots of tips, just excellent. It takes some of the "fear" away from surface mount.
Personally, I might have slipped some heat-shrink tubing over the too-coarse needle, and shrink it to have a finer applicator, but the fact he did it as is and it worked, is wonderful.
...and per a later comment, the heat-shrink could be cut at an angle to dispense somewhat downward, I think. Finding thin enough heat-shrink might be a problem. All this is theoretical.
Kevin, thanks for the video. This is the first time I have seen surface mounting done and between watching the video and reading the comments I have learned a lot. It has made me feel that "Yeah, I can learn to do that".
When doing it without a stencil, just dab the solder paste to the components, Use a toothpick to wipe off any excess if need be, then place the parts on the board with your tweezers
You have everything ok. A friendly voice, and a very professional way of working. Everything you teach comes fine!
I don't know if someone has already written this down but I'm going to share it anyway.
If you want to use the solder paste syringe to manually dispense, then for the very fine pitch pads you could buy from your local pharmacy (if they are available) empty fine-tipped syringes (the insuline injection type) and use them as a kind of scoop.
You dump some quantity (paste) somewhere off the board and you use the fine-tipped syringe to pick up a small amount of solder paste each time to lay on each pad.
The reason I am suggesting a fine-tipped syringe and not a needle for example, is because the tip of the syringe is an diagonally cut tube which means it is concavely shaped ( kinda like a spoon) on the one side which can hold some paste more effectively than just something cone shaped.
It is a bit time consuming but it is a lot better than bridges due to excess solder and you can save yourself some trouble from having to use the hot iron and the wick. Sometimes using the wick removes more solder than it should, you cannot exactly control it.
The manual dispensing way presented in this video is fine if you want to go for it. I just wanted to share some of my experience, so no trolling please.
PS: Also Kevin Darrah, you might wanna start considering some hot plates for properly heating up and re-flowing for your assemblies (provided the boards assembled are one-sided and small enough to fit on the surface of the plate). Some components (and yes that includes ceramic caps and resistors) DO NOT like thermal shock as you probably know. A hot plate can be a cheap (kinda) solution to that.
Alright that's it, I'm out. Bye!
That's nifty. Very cool when the paste reaches that critical temp and reflows like that, very cool, haha. Can watch that for hours I think.
Good show. It's good to see the two ways of doing it side by side and how cleanly they can be done. Thanks!
Thanks for sharing. Just to add some point of benefit, when you paste the PCB by hand and you make a mess by bridging the pads, I would not recommend to use the iron for cleaning it as you did it here, rather run some flux over those pads, change the tip of the iron into a flat blade that covers all the pads of one side of the chip (they come in different sizes) then simply wipe them all outwardly, away form the chip, you'll notice the pads nicely and evenly soldered with no bridging at all. And finally, don't forget the golden rule, ESD protection. Carry on the good work.
Wow, Kevin you are indeed good at this. As an old school engineer I remember when we first rolled out SMD designs in the 80's thinking, well this is the end of the garage tinkerer. Obviously I was wrong. What impresses me most is the number of connections being made and the fact that you were able to make good ones without shorts/opens the first time. Keep it up. Maybe an old school guy like me will be motivated to give it a try despite the fact that my garage is full of old PIH stuff. :)
Great video! I don't know if anyone else mentioned this, but in addition to the capillary action, it's the surface tension of the molten solder that pulls the parts into alignment with the pads.
Watching this... one tip is you don't really want to crank up the air temperature that high. I assume you are using leaded solder paste.
You want as much airflow as is practical and as little temperature as is needed to do proper reflow.
With high temperature air and low air flow you are creating large temperature gradients and this is also damaging to components. You can have the top of your component be very hot (directly to very hot 400C air) but the pads still relatively cool. High air flow tends to equalize and spread temperature much better which means you can use cooler air flow.
Also try to soak the board and components in hot air in lower temperature before you get to actual reflow temperature. This is what would usually happen in professional reflow oven btw. If you preheat the board the gradients will be less and the whole process will be more forgiving.
The way I would determine is I would crank up the cool air until parts start flying away, then reduce it a bit. I would then crank up temperature to see when it takes few seconds to start reflow, not too fast, not too slow. I would soak the board from bit further away and when I'm satisfied I would close in with the gun and do the reflow itself.
It is not leaded solder paste. Would the temps be higher in this case?
@@BrowFinGarf that is right, as non leaded solder has a higher melting temperature
Thanks! Very helpful. Especially useful that you showed best case scenario with template mask and worst case sloppy hobby scenario with hand applied solder paste. Both worked! Great that you showed how to clean up a sloppy job including solder bridges. Good job! Nice video!
Great video but I have to correct you on something. The capillary action only happens between the flat bottom of the pins and the flat pad because it's a narrow space and capillary action is the ability of a liquid to flow in narrow spaces without the assistance of, or even in opposition to, external forces like gravity.
What you mentioned about the solder separating and grouping around the pins is due to surface tension not capillary action. Surface tension is the elastic tendency of a fluid surface which makes it acquire the least surface area possible so droplets separate and group around the pins cleaning up the spaces between pins of solder.
thanks for jumping in with that!
Great comment, but I have to correct you on something. "Capillary" applies to narrow tubes. Surface tension is a more general term, and capillary action relies entirely on surface tension.
Liquids forming into droplets is another phenomenon that also relies on surface tension, in the case where a liquid adheres to itself more readily that to any adjacent surface or material, or in a vacuum.
Also "ability of a liquid" implies that the nature of the liquid is all that matters. The nature of the surface is just as important, as evidenced by the failure of solder to take on some surfaces. The solder will adhere if energy state of the surface in contact with the solder is lower than that of the surface in contact with the air. Systems tend to change to lower energy states when possible, sometimes needing a "push" in this case the application of heat in the presence of flux.
I think it is the combination of the two phenomena that make things easier while soldering
When soldering you do not want the liquid solder balling up. That phenomenon makes soldering more difficult, not easier.
I usually center the component, then add solder paste. When I was taught, I was told that they are very small solder balls inside the paste. So with that under the flat surface of your component, it allows the potential of that component moving around. It makes sense to me, and its the only way I've done it. Also, you don't really need to add the solder paste directly on the pads, just get it close. When the solder reaches melting temp it'll walk right up your pad/ lead. Downside is if your hot air jet tweaks when you're running it back and forth, you create a big potential for solder bridges. So steady hands are always nice lol. However, I suppose at the end of the day multi leaded devices are just generally synonymous with solder bridges. But you know what they say, different strokes for different folks. Just a different outlook on other methods. Great video man, thanks for making it!
Your vids are some of the easiest & informative to watch. Thanks on the stencil tricks!
One of the best explained tutorial that i saw about soldering SMD. Thaks from Argentina.
Great video! I've watched many SMD tutorials. It's helpful to see multiple engineers show their methods. Keep producing great content!
Good video. I like that you've demonstrated both methods and how to fix bridges. Also, thank you for providing the links to the tools and parts (reflow station and the PCB service provider).
no prob, glad you found this useful
Take a small blob of blu-tak, shape it into a point, and stick it to the end of a pencil or empty pen. Makes a very accurate pick and place tool! The only thing it doesn't have is a release, so that's where your tweezers come in: touch tweezers to top of part, withdraw pick tool. The sharpness of the point on the blu-tak can be adapted for different part sizes, e.g. blunt for larger parts like your MCU, very sharp for teeny SMD caps and resistors. When blu-tak gets dirty and stops picking up parts, squish and remold - it'll be good as new.
Hey man ! thank yu for the video ... I have been soldering the pins one at a time ... killing my eye sight ... will definitely change to paste method now ... darn .. got all the tools to do it ... could have saved hours of work .... I must have built up more than three four thousand boards bu hand .. thanks again
When you are cleaning up the bridges it helps to apply some flux.
It took me too long to realise this, flux and a reheat does wonders :)
Very COoL. Best video on SMT "start to finish"... Being a old-school 1w "resister scale dude" I never realized how do'able this was. You've INspired me to downSIZE. BTW.. Really nice (camera) work. Thank you (subscribed, of course:)
Something I have used to fix solder bridging is an iron tip with a flat face. Cleaned well, it allows you to drag the corner of the tip against the board, the face against the tip of the pins. The face of the tip wicks up the excess solder and by dragging the iron across the pins it evens out the solder left behind.
Can't remember where I picked the technique up from, but it works in a pinch.
armorer1984 link a video! Please!!
This is exactly the kind of project that I was looking to do for one of my future projects. This stuff is awesome!
Nice, but in the second method could you not have put the paste on the pins and then put the chip on the board as a way to keep from using too much paste?
Congrats on the patience. :) I've done some small raster soldering by hand in the past and I find it too time consuming. IMO stencil is surely a way to go if you have more than 2-3 boards to do. Cheers!
If you're applying it by hand it's easier to do it CNLohr style - using a toothpick instead of the syringe it came in.
oh man, that's a good tip! Most of the time I just pick up the stencil when I order boards, so hardly ever do it that way... probably shows in the video :)
The glass PCBs CNLohr makes are really amazing, too.
And he doesn't even have through-hole or breadboards, he just goes straight for the SMD, his prototypes are done like a final product lol.
Excellent video. Really cool and makes me feel more comfortable possibly making my own boards with smd components. What I have done before with soldering smd is use really fine braided wire as a wick. I have a large roll of telephone wire that actually used fine braided wire instead of solid. I almost threw it out but if I twist the braid really tight it makes a fine solder wick.
there are many videos showing this.. but this one is the best
could just drag solder the chip. and hit the caps and resistor just as quickly.
and look just as good
Good job. I never seen anyone use a stencil, but one thing I noticed when you didn't use the stencil was the crystal oscillator shifting position. from my experience, the solder paste has two states. it helps to firmly press down on the component until it reaches the chalky state. shortly thereafter, you can see the little spheres forming and identify the desired state.
Kevin, I have stubbled on your youtube once again.. Awesome as always... great job showing how to do it.
Now after your tut I have the confidence to try my hand at this technique.
Great video, learned a lot, whats the name of that thing you use to remove the extra soldering paste in min 16:46?
You should be a surgeon 😷 very steady hands - great job.
Thank you! Thank you! Thank you! I appreciate a human explaining what is going on!
I went to Kennedy Jr. High in Woburm,Ma. I remember a tall thin classmate with your name. Fantastic video,and technique.
try tacking 2 corners of a quad pack. then run a bead of solder paste across the remain legs then heat. It should minimize the solder bridges as well as make it easier to set them in place. Add additional flux when touching up will eliminate the need for the additional heat source, also try using the drag method that's how I was taught.
Cool. so satisfying to watch how the paste melts
Good video Kevin but as someone else pointed out it's not the capillary action, it's the soldermask that prevents the solder from attaching itself to anything other than the pads. Well in theory :)
Beautiful! Great video! I don't have a stencil (although after watching this I think I will pay the extra for one next time) but instead apply paste directly using the pointy end of a cocktail stick. Seems to work OK.
It's a great video and thank you!! On my Chuwi Hi9Air tablet, I want to disconnect battery. Manufacturer has two battery poles ending not on a pin connector, so, pole cables are connected on the motherboard soldered. Two pole cables are extremely thin, and also, soldered cables ending are extremely small. I have never seen such a tiny solder. I find it too difficult to unsolder. And if we suppose I unsolder correctly, without any damage, soldering back, e.g. battery replacement, the new battery, I mean the pole cables, is extremely difficult and risky to solder without doing any e.g. bridging damage, and finally damaging completely the motherboard. Would you have something to suggest me in all that? Thank you for your time!
This is a great way to do if you don't have shaky hands. Well I DO!PCBWAY will make ten 100x100mm boards for only $5! Get the red ones they look and work fantastic!
Great video! Really enjoyed seeing how this can be done at home.
you could have used flux to get the solder bridges away
He did, the wick was soaked up with flux.
Yep, I've only done that way over, literally a million times in my life.
It does take a skill set, many people will never have ;-)
Either you've soddered decades doing nothing else or you literally don't know the definition of literally.
Who knows - maybe he works at Foxconn. :P
I've done it that way _physically_ a million times. Get on my level, nerd
16:00 before touching to fix the solder bridges the chip pads need flux in order to make the solder stick to the pins ...
Have you tried using flux for touching up the manual one? I think it would make it much easier :)
Even you drank too much coffee, your hand is still more steady than 90% soldering youtubers LOL
Ha Ha. almost 70 but don't have the shake yet. Hopefully it stays away.
When you do the bridge cleaning using excessive heat can those tiny electrical path damaged?
When applying solder paste without the use of a stencil, simply paint the paste on with a small paintbrush. A small amount of paste goes a long way and a thin coating will generally not result in bridging.
I just received two of the Atmega328 boards. I'm waiting on the SMD 328s to arrive and then into the Toast-R-Reflow. Good work Mr Darrah.
Thanks!
Can you check me on this. C1 10uF and C2 and C3 are 100nF?
Just a thought, but wouldn't you have more control over where the paste goes (when not using a stencil) for the chip pins by applying the paste directly to the pins, and then positioning it on the board?
just watching and wondering... Would it not be less messy to apply the solder paste to the pins and then push the pins to the board?
It is the best practice for large pcb quantities.I think that the pcb manufacturer can make the solder mask stencil also and ship it along with the boards to make the life easier somehow.Otherwise you have to etch it on your own but it worths in massive production and not for few boards.
Use a hotplate and preheat the boards. Then while still on the hotplate use the hot air to flow the solder. Allow the solder to set before removing the pcb.
The most questionable but super cheap method is to put the PCB on the hotplate cold, let the heat rise until the solder flows then turn off the power and allow to cool. (Some components don't like this.)
Final cleanup with low water isopropyl alcohol (91% or better).
The more examples of technique the better. Everyone has a style.
That was awesome. I learn something every day.
Thanks for this video. I wonder what temperature your touch-up solder iron is set at.
Hi Kevin.
I noticed some of the second board getting a bit burned there. Can that lead to complications or is it just cosmetic frustration?
Damn if I knew solder paste worked like this I wouldve ditched regular solder years ago.... Does the 400 degrees not damage any of the components tho?
Thanks for sharing. Will this method work on the Atmega 2560 (100 pin). Thanking you in advance.
Hi, what kind of resonator did you use for the microcontroller? is it 16MHz ? Can I find that in EAGLE library ? What's the package type for this resonator ? Thank you for video.
havent tried it yet but ive seen an etch done wit flattened pop can with coating removed.... toner transfer and acid peroxide etch. I might give it a shot at some point with riston. Last summer I construsted a vac press exposure box from plexi, low iron glass, 365nm 4.1w led from digi key, vaccum pump from ebay/china, pvc, and weather stripping. Also a vertical bubbler tank for cupric. all i lack at the moment is a tested/confirmed stencil making system. otherwise i can do 8mil on 2oz and enough alignment on dl to do through hole. I figured out that part is easy if i add marks to transparancies and align then glue a strip of preff board between them...makes a hinge that the cc goes between then exposure press box does rest, flip and repeat. I usually drill a hole through template sandwitch and cc so alignment is confirmed on flip. only shit part is i dont want cupric inside and mn has a limited etch season. otherwise a 4x6 dl costs like 4 bucks in consumables.
Awesome technique - what hot air blower do you use ? Need to find one in Australia.
I've seen this done with a concave tip and flux - very fast and clean.
Nice job!!!
Can you please recommend on solder paste?
Excelent job Kevin! Congrats! Today I learn something very important from you. Tnx!
Could you add the paste to the micro first then set on board? That way gaps between legs might not get filled in
What temp do you have your soldering iron at when cleaning up the bridges? Also, it doesn't look like you tinned the tip? Or at least wiped off any excess? Thanks for the video...
usually between 300-400C - it's a pretty crappy iron, so I'll just brush the tip on a brass sponge and that's pretty much it
I'm wondering if someone makes a piezoelectric paste applicator?
Thanks again for the great info Kevin.
Great demo. I especially loved the mask vs no mask.
thanks for the video
2 quick questions. I looked through the comments and didn't see these questions asked. sorry in advance if I missed them.
1 what thickness is the stencil?
2 what is your paste expansion rule? how much larger is your stencil opening than the pad you are applying paste to?
thanks in advance.
Ron Morgan hmm, I remember having to SHRINK the stencil holes for a 328p. Just fyi.
Where do you get your PCBs made? The link you provided has a PCB Standard Service for $12, 4PCB is good but it forces one to get many boards to have good discounts.
their 2 layer service can get you 10-12 boards for $12, it's a really good deal. Pretty buy all my boards from them
Don't know if this helps - my paste dispenser has a smaller needle and needs a bit of pressure to get it to come out. I found if i held the dispenser quite vertical and gently tap I could control how much comes out to a high-degree. I literally apply paste to each pad one by one this way under the microscope. Then try and drop the components onto the pads so as not to smear the paste and then the heat-gun reflow completes neatly. I'm using lead free too - not sure this matters.
Could you please share the temps. you are working at. Really good clear video; thanks.
Thank you SO much for this video! Super informative and helpful. I wish I could give it more than 1 like!
Would it be better to heat the PCB from the other side? I damaged a bunch of MOSFETs recently.
Hey Kevin.. I looked around at your various pages and cant seem to find a place to purchase one of those 328 breakout boards... Are they available for retail yet ??
not quite - going to ship one out (assembled) to all of the patrons first for testing, then if all goes well, I'll get some on order an make them available on mklec.com
I look forward to it. Thanks.
Dip a toothpick in the gel type flux and use that to pick up the components. I find you have much more control than using tweezers. Once placed onto solder paste the component will release. Obviously a vacuum pickup with foot pedal is even better.
What a great demonstration, thank you very much.
Great video! I've watched it like a mini-thriller :D
P.S. I think that in some cases it's good to check for continuities with a multimeter before testing an assembly.
Great video thanks! I never realised solder paste tubes had that wadding thing, I love that Sharpie! Do you know if tubes of flux have the same thing? Cheers!
yes, I just picked up a tube of this stuff: www.amazon.com/gp/product/B01GRJ92T2/ref=oh_aui_detailpage_o04_s00?ie=UTF8&psc=1
What's the crystals part number you used in this demonstration?? Thanks
Is flux necessary (would it make for better results) when using this method?
for the caps and resonator, can you use an iron instead of the air? on solder paste that is
Put a bit of solder in the wick first before using it. It transfers the heat through the wick much quicker. Use flux heavily during the wicking.
Did you burn the bootloader using your USBasp? Or using another arduino?
If you already have parts on one side, how do you do the other side?
Or, if you're me, and really poor, i.e. I can't afford a hot air reflow station, you hold the board six inches over a BIC lighter and hope for the best. :P
I've actually soldered a QFN24 that way (a CP2104 USB to UART chip), and yes, it worked.
Cool! look like pro to me! Where did you get the "stencils"? tks.
I can see that the stencil makes a much neater job! Can you make the video again with tighter angles, and a fixed focus, as the camera keeps going out of focus...
you have some very good information that has helped me quit a bit, I'm curious what kind of education you have and are you an engineer for a company. I became interested in computer programming at a young age with a commadore 64 and over the years i have kind of played around with programming. i have a couple of years of electronics engineering, but i never attained a degree. Almost all the electronics knowledge i have is self learned and you appear to have quit a bit of knowledge, so i'm just curious if your knowledge is self taught.
Where do you go for the PCBs? I've played around with arduinos etc for a couple of years but now I've taken on a project to create my own keyboard for my final year university project and I'm thinking of creating some simple through hole PCBs for it. Could use somewhere that can do it for cheap but reliably.
check the description - electrodragon also has cheap PCBs, so you can get the stencil and boards at the same time
OSH Park does really high quality PCBs. It's $5 per sq. inch for 2 layer boards (silk-screening on both sides too) and that includes 3 copies of your board.
yep, use OSH park all the time as well
James Coyle
Well Presented and invaluable. Thank You, Kevin.
the 2nd method needed the pins flooded with flux and a little less paste on the pads. then it would come out just as good !
Thank you +Kevin Sarah . That will really help a lot. Is it possible to 3D print stencils?
Can't see why not! Nice Idea.
Victor Rivarola I don't think the average 3D printer is even remotely precise enough to make stencils for SMD parts - those IC pins have very close spacing!
Closer than 0.3 to 0.1 millimeters? That is the resolution of your average 3D printer!
Victor Rivarola A 3D printer has a nozzle what, 0.35mm large? No, that's not nearly small enough to *accurately* lay down a stencil for a common QFP with 0.65mm pin pitch. (That is, 0.65mm from the center of one pin to the center of the next.)
I noticed that the dot on the micro was not lined up with pin one on the board or am I seeing this wrong.??
There's enough solder on the pads to cover all the leads??
Great demo. Clearly explained. Thank you.