> This was my first time soldering DFN packages and theyāre tiny! Because I donāt have a microscope or anything to visually inspect my soldering and these components were mostly just handling power anyway I just checked for shorts between power and ground and tried to take close-ups using my phone to see if I could spot any shorts. The technique that ended up working well for me to solder on these DFN packages without a stencil is to put what can only be described as way too much solder paste on the pads and then pushing the IC in the pool of solder, when the solder melts from the heat of my hot air station the IC will float on top and then I push down on it with tweezers and all excess solder will squeeze out and bead up, hopefully landing somewhere on the solder mask, where I can pick it up later once itās solid.
This is positively an insane methodology for soldering. Fun, but insane.
I actually can imagine that it works, strangely enough. But I don't think you'd get much consistent reliability with this. More like it'd work often enough that its good for one-off projects.
It worked for me 8 times :)
Thankfully the bottom pad on DFN packages reach the edge on 2 sides and I would think this technique wouldn't work with QFN.
QFN is (very, very slowly) opening up to the idea of "wettable flanks", which is increasing the reliability of QFN soldering anyway... which is increasing the opportunity of "side-soldering" QFN packages.
https://www.ti.com/document-viewer/lit/html/SSZTBN6
Here's to hoping for more manual soldering techniques to work into the future! We all know that these parts are getting extremely small and harder to work with, but its still clearly possible to make devices.
But yeah, QFNs, if this wettable-flank trend continues, could be quite reliably soldered and inspected from the sides soon. The needs of the high-reliability automotive industry to create an inspection methodology outside of X-Rays is driving this change.
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Glad to hear that your technique worked in any case. I wouldn't have tried that, but maybe I'll try it once next time I have a hot-air gun out and a DFN part to try it on.
EDIT: Note that Microchip apparently has some DFNs that also have wettable-flanks: https://www.microchip.com/en-us/about/media-center/blog/2022...
> The needs of the high-reliability automotive industry to create an inspection methodology outside of X-Rays is driving this change.
Why is that a particular requirement? Or is it just nobody wants/rather avoid x-ray, and automotive has greater need for inspection at all?
That's very interesting, I've always found QFN to be annoying to work with
To save others from looking up DFN / QFN:
DFN -> Dual-flat no-leads package
QFN -> Quad-flat no-leads package
The important note is:
1. Longer leads of older packaging have higher parasitic inductance, parasitic capacitance, and parasitic resistance. Which hurts many electronic designs.
2. The thermal pad on DFN / QFNs allows for direct-heat transfer off of the chip-package (while DIP, SOIC, and other older designs do NOT allow for this direct-heat transfer off). This improves thermals of hot parts, as you can use the whole PCB as a heatsink now, instead of having to add a heatsink elsewhere.
3. DFN and QFN are physically much smaller than traditional DIP, SOIC or TQFP packages. So people who use these smaller chip packages can make even smaller circuit boards, or alternatively, a more complex design fit in smaller spaces.
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QFN and DFN are very popular parts for modern professional level electronics. But do note that their small size and tiny leads make them harder to deal with at the hobbyist level. But its possible with enough flux, solder paste, and hot-air rework to work with these parts.
I would recommend that beginner electronics who are just getting into custom PCB design work with larger parts (like SOIC packages) instead. Bigger is often easier. Move to these tiny DFN or QFN parts only after you've gained confidence in your surface-mount skills.
I'm not sure why "too much" solder paste is needed to make this work. I've done something similar on quite a few occasions, but using regular solder. Just put a slightly generous amount on each pad, but not enough to create any shorts. Add flux (ideally, something rosin-based that will last longer in the heat of the next step). Heat up the whole footprint with the hot air gun, and gently place the IC on top.
This method saves blasting the IC with hot air while heating up the whole lot.
"Way too much solder paste" is a codeword for "I didn't buy a solder-stencil", which is reasonably common on cheaper projects in my experience.
Instead of using a solder-stencil to deposit a carefully calibrated amount of solder onto any location, you can buy a solder-paste syringe and squeeze the solder-paste into place.
This almost *always* results in too much solder, because its a hand application process, and its often better to have more-solder + cleanup than too little solder in my experience.
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https://www.amazon.com/Solder-Bi57-6-No-Clean-Lead-Free-Temp...
Obviously if you had perfect hand-control (ex: a solder paste robot... or a solder stencil, or other methodology), that's preferred.
But if you're doing these cheap designs you'll need to plan for the "too much solder" situation. In fact, "too much solder" is the default choice and quite fine, albeit with a simple cleanup step. (Ex: swish around a small piece of solder wick in my experience while the solder is still hot, or while the solder-wick is touching a soldering iron, etc. etc. Plenty of cleanup methods available).
Do it dirty then clean-up is just the default mode of operation in hobby-level manufacturing / solder paste / soldering. Its surprisingly effective.
I don't know if it's equipment or a skill issue but I had trouble with putting an even amount of solder on the pads this way. I have seen this approach on YouTube.
Assuming you have the thinnest tips, solder, and solder braid you can find (they shold be comparable to the pad sizes you are soldering, for this kind of work), honestly it's probably a skill issue. There's a "feel" for how much solder the pad needs, and it's a bit less than the most it can take, as it'll get displaced outwards when the IC is applied.
Perfectly valid method, IMO. I always put some vias in the thermal pad and expose the copper on the other side. That way the vias don't get plugged with solder mask and wick away excess solder. It also lets you heat the thermal pad with an iron from the other side for real low-budget SMD work.
Squishing the chip down is fine, you just have to be careful to align it with the pads properly. I don't think I've ever seen a solder bridge on a QFN other than a big ball on the outside edge. Modern solder alloys and solder masks are really good at preventing bridges. The solder really doesn't want to stay between the package body and the solder mask, it will try very hard to only stick to metal.
Perhaps I should better explain why I dislike it.
A lot of parts (ex: Crystals) are extremely heat-sensitive. So even just a few dozen seconds extra of soldering could damage your crystals (ex: internal solder will reflow and break the vacuum seal).
So *ANY* action which requires you to "carefully squeeze down" the solder paste out means you're going in there with tweezers, and possibly leaving the board in 200C+ soldering temperatures a bit longer than usual.
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IE: Its not that this technique "won't work" in isolation, its that you won't get "consistent and reliable results", especially when we consider the nearby parts (ex: a possible XTAL) that could be damaged while you're messing around with the hot-air gun.
The standard technique of reflow soldering is to use a solder-paste stencil to deposit the "right" amount of solder paste onto your board, then use a reflow oven to carefully heat the board (and hold the heat) at the right temperatures, so that nothing gets damaged.
Once we start relying upon "Well, keep the board heated a bit longer so that my tweezers can do the work" is when you start overheating chips and otherwise creating failed parts.
> Modern solder alloys and solder masks are really good at preventing bridges. The solder really doesn't want to stay between the package body and the solder mask, it will try very hard to only stick to metal.
This also matches my experience. The surface tension of solder (be it lead based, or lead-free, or low-temperature solder paste) is far greater than most people expect.
You can strongly rely upon "surface tension" to magically do the right thing on your boards, as long as you've got good quality soldermasks.
In fact, a big problem with reflow soldering is "tombstoning" (ex: surface tension of lead is so strong, it pulls your components OUT of position). There's a LOT of surface tension at play here. Its great in most cases, but keep an eye out for those tombstones!
Everything that could go wrong in my experience is fixed with rework hot-air + generation applications of flux + solder wick + soldering iron + tweezers. And rather easily mind you, I know that didn't sound very easy but... the right tools make any situation fixable. Its just knowing how to use all those tools in the right cases.
I extend the pads out from underneath the chip. Then it's easily hand-solderable if needed.
I would love to see more standardization for consumer NAS builds. I've been asking ASUSTOR in particular for a few years now if they'd consider building a Mini ITX-compatible backplane/adapter, so you could swap out the backplane after a few years if you want. Or even Pico ITX or something, so you could swap in an SBC.
I hate that after 5 or 10 years, NASes can't really be upgraded. A lot of 1 Gbps NASes could be upgraded to 2.5 Gbps or even 10 Gbps if you could swap out the motherboard, keeping the chassis out of the landfill or extending its useful life.
I'd love to see Framework get into this space. It is such a HUGE waste to retire my NAS chassis and backplane when the compute portion gets too old. There could be some good synergies with the Laptop 13 mainboard, having a laptop-level TDP and with ARM possibly coming around the corner. Where I feel the risk is the market for NAS appliances doesn't feel very big ("prosumer" and mom and pop businesses?) and the differentiator really is in the software, not the hardware. i.e. People buy Synology for DSM, not the hardware.
I think I read somewhere that Framework doesn't have any plans to get into vertical integration, which saddens me. I'd love to have a Framework backed OS and have things working perfectly out of the box like sleep and touchpad feel.
In that front I wish their FLASHSTOR product was a 6/12 bay NVMe add in card rather than an integrated motherboard+pcie switch+soldered CPU+soldered RAM. I'd love to just pop that kind of thing into a normal PC but all the ones I've found are either 4 porters or extremely expensive.
Buy a Supermicro board, build your own back plane or use an off the shelf one, and add as many expansion cards as your heart desires (and mobo can handle).
I always admire the depth and effort people are willing to get into, especially if the chance of messing up means losing actual money, like tweaking guitars or hardware. I assume you have to gain some experience with soldering irons or woodworking tools elsewhere before taking the proverbial axe to a project like this. I wonder why there isn't much of a market of more hackable small form factor boxes where it's easier to tinker with the hardware or software. I'd love a consumer (price) level NAS where the OS can be ripped out and replaced with some vanilla OS/kernel.
Or maybe I'm just too chicken with modifying actual physical objects.
I built my own NAS for a total cost of Ā£1000. 24TB physical drives, 16TB useable (Raid Z2). It runs Ubuntu LTS server edition and I spin up any containers I need in Docker using Portainer. Is it a point and click GUI that is friendly to all? No ... I have to manually create SMB mounts and the like in the terminal, but it's easy enough to keep running.
Hardware wise it's:
- Asrock Rack C246 WSI Mini ITX motherboard - 32GB ECC RAM (2x 16GB UDIMMS) - benefit of using the C246 chipset - Intel i3-9100T - 6 IronWolf 4TB NAS drives - 2U Short Depth rackmount chassis (so it fits in my network rack) - 1TB Samsung 850 Evo boot drive
Idles at 23W which is low enough for my tastes, ramps up to 65W under load (I spin the disks down after 10 minutes of inactivity, even doing that I'm only seeing about 10k load/unload cycles a year (drive is rated for 600k).
For the lazy-but-not-so-lazy you can just install Proxmox, as weird as that sounds at first. Still Debian based, still supports root on ZFS with the GUI installer, and then you get a virtualization/container host with a friendly GUI on top for free. You can even make you NFS/SMB/Whatever shares as containers if you want to compartmentalize.
There's also free distros like OpenMediaVault for making a NAS with a nice web UI.
Did you build this a while ago? 4TB drives are tiny nowadays. If so, the price isnāt really comparable is it?
About 2.5-3 years ago, yes.
Ever wrote a build log for that? Would love to read it.
I didn't I'm afraid, but it was just like building any other computer, except repinning the 24pin ATX connector for the motherboard as it uses a 4 pin connection only (still Molex branded).
> Asrock Rack C246 WSI Mini ITX
Who do I have to kill to get one :)
These peeps seem to have some in store: https://www.senetic.de/product/C246WSI but (a) I didn't find a way to change the language on the site to English, and (b) while they ship to several countries, those are mostly in Europe. If you can work with these restrictions, you might be in luck! (I have never ordered from this shop and can't vouch for them, but they seem legit.)
This probably isn't normal consumer price, but supermicro makes some very nice nas-targeted hardware that you can populate with your own drives and choice of OS. I have one with 183 TB running trueNAS (zfs) and it's great.
They're just bog standard x86 boxes with a lot of drive slots, a backplane, and a lot of sad or sata ports and controller capacity. There's a pretty healthy used market in these things also. But they are targeting people who want to put 10 or more drives in a single enclosure, which is why I say they might not be consumer.
SuperMicro stuff has gotten so expensive. I remember when they were first getting started and even years afterwards, and it's nothing like today.
Honestly, best thing you can do now is just live with a tower server or buy off-lease from eBay. We've passed the hump where the off-lease eBay specials had the energy footprint of a small factory and used turbine jet engines to power the fans and cool things down.
I did buy once buy a no-name (ATX?) 2U case/rails only from eBay, but the manufacturing, accessibility, ergonomics, design, and everything else were terrible enough that I would not do it again.
> I'd love a consumer (price) level NAS where the OS can be ripped out and replaced with some vanilla OS/kernel.
Are there any good options today? I keep thinking of picking up a NAS, but I really do not want to use a proprietary vendor OS that might feel entitled to scan my data for useless/hostile cloud integrations. Or might have left some hardcoded password backdoors.
Ugreen NAS - currently on kickstarter for this summer - but it's a reputable company.
https://nas.ugreen.com/pages/ugreen-nas-storage-preheat
Their hardware is dramatically better at the price points then the alternatives - even if they do have some comprimises.
Wow, those hardware specs are nice. What compromises do you refer to, specifically? I think that the 8GB ram and 128GB flash cache are on the small side, but both are user-replaceable so not that big a deal.
The only thing I really miss here is ECC ram, but that's entirely due to Intel's market segmentation and not something they can change, save by completely changing their platform vendor.
Interesting! Unfortunately no power draw numbers.
I ended up downgrading my chunky Supermicro server to a cheap Chinese AOOSTAR with an Intel N100 for $199[0], and slapped in an NVMe drive and extra RAM. Since I only need 8-9TB of storage, a zpool mirror worked perfectly for my use case. The build quality is mediocre but the product is more than adequate for my home NAS use case.
[0] https://aoostar.com/products/aoostar-r1-2bay-nas-intel-n100-...
Newer TerraMaster models also come with an internal USB port and flash drive that can be replaced. Theyāre basically an Intel NUC with a storage controller. Iāve got the F4-423 on my shopping list for when my Synology DS-415+ finally dies.
From the same site https://codedbearder.com/posts/nixos-terramaster-f2-221/
NAS dual 3.5" HD, dual M.2 NVME, dual 2.5GbE LAN. BIOS quality unknown. Barebone no RAM, expandable to 32GB. BYO OS.
Intel Alder Lake N100, $189, https://aoostar.com/products/aoostar-r1-2bay-nas-intel-n100-...
Ryzen 5700, $299, https://aoostar.com/products/aoostar-r7-2-bay-nas-amd-ryzen-...
> This USB header is only USB 2.0 though so it's not an option for this purpose.
Not questioning a great project, but just curiosity about this small aside: why is USB 2.0 not suitable for the OS?
On a NAS, is it doing anything other than boot-time reading, and maybe occasionally writing a little data?
I run a NAS on a USB 2.0 boot disk, and the only issue I have with it is that systemd-journald really isn't built with slow disks in mind. Doing a journalctl operation with 6 months of log files takes a good minute or two because of journalctl's non-optimal file access patterns.
Not mentioned in the post but I also run some light server workloads on this machine and things were annoyingly slow with a USB 2.0 thumb drive.
I'm not gonna pretend that the real reason for making this wasn't because I have fun tinkering though.
It's a great project, and your solution is also technically superior to running off USB 2.0 thumb drives.
+1, I was wondering the same thing. Genuinely curious.
I'm such a bad hacker. I had the same issue with having an external drive plugged into my NAS. What did I do? I just used velcro to attach it to the top of the NAS.
Maybe you value your free time more than me :)
Just the opposite I would say.
Mine just sits beside it.
Similar here, but hot glue is my go-to for stuff like this. :)
This looks way cooler than the "custom" case I made out of Legos to house my homebrew NAS. I had four USB hard drives plugged into a hub and that hub was plugged into an Nvidia Jetson. I wanted to make it self-contained and knockoff Legos are so cheap that it was an easy experiment to run. Also fun.
This looks a lot more professional and I'm kind of jealous.
Surprising and elegant. That's an amazingly long way to get by guesswork, a bit of trial and error, beeping out circuits, and surprisingly casual substitution of the load switch IC.
Thanks! There was an incredible amount of information I gathered from various forums and stack exchange that I had to sometimes just reluctantly view as facts :D But it worked out!
Itās really cool. Iām glad it worked. What you didnāt know probably kept you from analysis paralysis.
This is an awesome solution.
I have the 5-bay variant of the same NAS. I decided to put TrueNAS Scale on it using a Samsung USB stick using the internal USB. I chose one thatās widely used for Tesla dashcam, so I know it is at least somewhat durable.
Iām happy with it so far. I still find the CPU performance very lacking so Iām planning on upgrading to something beefier.
Oh absolutely the CPU is lacking in performance. I actually entertained the idea of replacing the motherboard with a custom carrier for some arm compute module or the new Lattepanda mu but I suppose I should first use my new project that I spent so much work on :p
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