How to do SMD Reflow Soldering properly! || Hot Air VS Sand VS Reflow Oven

Recently I designed a new PCB for projects which is based around a super tiny SMD IC its package is called 14 leads MLP while MLP stands for micro lead frame package and 14 leads means that there are 14 pins positioned all around the IC Now I actually tried hand soldering this IC in place with the same techniques I showed you in my how to solder properly video But, as you would expect with such a tiny IC, it was pretty much impossible to create good contact with all the solder pads To solve this problem. I also ordered the stencil for my PCB design and in this video I will not only show you how to use it in order to successfully reflow solder my PCB But while doing so I will also try out three different reflow methods Which are: hot air, sand, and a reflow oven, in order to determine which one I would recommend Let's get started [music playing] This video is sponsored by Skillshare, which is an online learning community for creatives Where millions come together to take the next step in their creative journey When it comes to learning about electronics and creating electronics projects Then I have to say that Skillshare offers thousands of interesting classes Currently I'm taking a class about FPGAs: codes learn digital electronics with schematics And the basis to FPGA boards by arjmir golem hassan, and I surely learned a lot of new things by now You can get access to Skillshare for less than $10 a month with an annual subscription and the first 1,000 people who sign up via my link in the video description Will get two months of Skillshare premium for free First off in order to perform reflow soldering we need this Which is called solder paste and it is basically a mixture of flux and solder At this point we could use a flathead screwdriver Or something similar to apply the solder paste on all of the PCBs solder pads But needless to say this technique is rather unprecise To get better results, I firstly used Other PCBs I had lying around in order to lock the position of the target PCB in place then I simply placed the stencil on top of the PCBs and aligned its holes with the solder pads of my PCB and And once again secured it all in place with electrical tape Afterwards, I added a bit of solder paste next to the holes and use something like a credit card in order to evenly distribute the solder paste all over the stencil and As you can see after Removing it we get an even distribution of the paste all over our solder pads in a very precise way beautiful Next, I unpacked the components for the PCB and placed them, with the help of tweezers, onto their solder pads most of them were pretty easy to position But it required a bit of patience in order to get the main IC in position nevertheless though after a few minutes all of the components were on the PCB and It was time to reflow the solder paste Now if we Google this particular solder paste then we can easily find its data sheets Where we can find information about its reflow profile which basically describes how hot the paste has to become for how long in order to turn into proper solder Of course by using the first technique with hot air we cannot properly follow this profile But I can set the maximum temperature to around 300 degrees Celsius which is a bit above the maximum stated temperature of 250 degrees Celsius and after deciding on a medium wind speeds I slowly heated up the PCB solder paste and components through hot air, and as you can see after only a few minutes all the paste turned into proper solder connections you can also see that it is easily possible to overheat a component and I also had to touch up the IC solder joints as well as the USB type-c ports But after doing that I have to say that all the solar connections look pretty decent and thus I continued by soldering the rest of the THT components in place with a normal soldering iron now before I test this board in order to find out whether all solder connections formed successfully, I repeated the soda paste spreading component placing process in order to try out sand this is one kilogram of the finest sand that I could find on the Internet and My theory is that by filling up a normal pan with it and heating it all up with a normal stove We should get an even heat distribution all across the surface of the sand and thus good reflow results So I obviously have filled up a pan placed my PCB in the middle of it and started heating everything up The only problem was that the sand apparently never reached high enough temperatures That is why I tried a second attempt with a lot less sand And as you can see this time the reflow process worked out just as planned. I have to say these solder connections look promising, but Just like before I had to remove a bit of excess solder from the USB type-c ports Like already stated I will test the PCBs at the end So for now, let's move on to the last probably most professional technique the reflow oven I I got this one from the internet for cheap and After inspecting it for a bit, it seems like a low-cost version that could do the trick But if you take just five seconds to Google its model number Then you quickly realize that it comes with a few flaws which are luckily pretty easy to fix so I removed a couple of screws as well as its PCB tray and Lifted up its top cover to reveal its insides There I fixed the first big problem by removing the masking tape Which would have created a horrible smell if being heated up Instead I replaced it with Kapton tape, which is known for handling high temperatures well. Next I added a temperature sensor to the control electronics for the cold Junction compensation And also used an FTDI breakout board in order to reprogram the control electronics with an open-source software But if you want more information on this topic, then make sure to visit the websites that are linked in the video description As soon as the new software seemed to work just fine. I reassembled the oven and thus it was time for another solder paste spreading component placing run Afterwards I placed the PCB in the middle of the oven tray and closed it up The new firmware comes with a couple of reflow profiles out of which I tried out the custom profile 2 and later the AMTEC Syntech-LF profile In both cases the oven followed the profile lines decently and thus heated up successfully But in both cases the temperature was apparently also too low Because the solder paste did not reflow properly so my crude solution was to select the custom profile one which basically heats up the oven without an end and All I did was looking for the moment the reflow process took place, which was at around 270 degrees Celsius at which point I then quickly turned off the machine And just like that, I got this beautifully reflowed board whose USB ports I obviously also had to redo a bit That means I finally got my three PCBs, all reflow soldered with different methods at this point I finally tested my boards and without revealing too much about my next projects I have to say that all three of them work just fine The only question remaining is what reflow technique, I would recommend Well, if you got such a reflow oven Then I would recommend this method because it is the most accurate and professional one At least if you program in a suitable reflow profile for solder pastes, which is easily possible But if you got no equipment then I would recommend the sand methods Because even though it can get a bit messy It costs less than a hot-air station and you can also not easily overheat particular components on your board with it And with that being said, I hope you enjoyed this video If so, don't forget to like, share, subscribe, and hit the notification bell Stay creative and I will see you next time

Channel: GreatScott!

Views: 368,810

Keywords: smd, surface, mount, device, technology, solder, soldering, reflow, properly, guide, tutorial, how, to, make, project, beginner, beginners, electronic, electronics, paste, flux, pcb, mlp, package, tiny, small, super, IC, integrated, circuit, stencil, jlcpcb, usb, type c, type, power, delivery, hot, air, station, sand, stove, pan, profile, datasheet, oven, T962, T-962, hack, hacked, mod, modification, improve, open, firmware, software, custom, heat, greatscott, greatscott!

Id: DYrucIWig24

Length: 10min 15sec (615 seconds)

Published: Sun Jun 07 2020