4 ms·

BGA socket allows RAM upgrades on SBCs

31 points by zdw 5y ago

eternityforest 5y ago
Wow, that's awesome. This kind of thing could possibly make Chromebooks and the like repairable.
- Syonyk 5y ago
  What prevents you from repairing them now, exactly? Hot air rework stations have come down dramatically in cost, and there's no shortage of videos talking about how to do it. Try a few scrap bits before working on something expensive... It's nice to be able to swap things out with sockets, and you'll generally find me coming down on the side of repairability, but it exists with a variety of other considerations, and something that is less repairable, but also far less likely to fail in the first place, may be a better option. Also, I rather like the fact that soldered on RAM makes things like coldboot attacks a lot harder to pull off if you're using trusted boot. Heavy use of adhesives is certainly a problem, but I just can't get that worked up over soldered on RAM.
  - ClumsyPilot 5y ago
    I don't have a garage to keep equipment that I will use once in 3 years, I don't have scraps to resolder and that's probably true for most people. For whatever reason a real repairshop is a lot harder to find than a laundrette - I was looking for one to fix a GPU, and I could not find one.
    - colejohnson66 5y ago
      These sockets cost $60 a piece.[0] Four of them alone is already ~$250. Add manufacturer markup, and you’re looking at an extra $300 to the consumer. If manufacturers want to make RAM replaceable, they should be putting SO-DIMM slots (which cost single digits),[1] not BGA sockets. After all, the average consumer is more likely to know how to procure RAM sticks than raw BGA RAM from DigiKey, Mouser, etc. [0]: https://www.aliexpress.com/item/1005001841972537.html https://www.aliexpress.com/item/1005001841972537.html [1]: https://www.digikey.com/en/products/detail/10033854-052FSLF/1001323 https://www.digikey.com/en/products/detail/10033854-052FSLF/...
  - Ekaros 5y ago
    When I think about it it could certainly make layman repairing them cheaper. But I'm not sure if it really would chance too much with professional work, the parts and labour time would still be about the same or in same magnitude. And how often does RAM fail anyway? Or if it needs to be upgraded what about other parts?
  - eternityforest 5y ago
    Even replacing an 0805 is a pretty significant challenge. I have no idea how people do BGAs with anything but a pick and place. Plus, without x-rays, how do you know you got it right? There's a lot of ways something can have a weak joint that isn't immediately noticeable. And, unless you have CNC equipment the result is more art than science, the quality depends largely on your hands. I wouldn't trust a device that had been repaired by anyone but an experienced pro, seeing as how these devices(along with phones) are the cornerstones of modern life.
    - colejohnson66 5y ago
      What I've seen is: use a microscope is used to align the new part with the silkscreen outline. Get it good enough and turn on the heat. The part will self align as the solder melts.
      - BizarroLand 5y ago
        Which is fine for single item repairs or upgrades where the person doing the work is tech savvy and all parties are will to accept the loss of a functional device in case something goes awry. (Which, admittedly, is rare, but you have to take the liability on yourself every time). Something like that is entirely non-feasible for mass manufacturing of parts with any guarantee of quality though.
Syonyk 5y ago
> While it looks neat, I’m not convinced we’ll see barebone single board computers where users can insert their own eMMC flash and RAM any time soon, since it would likely add to the overall costs. A more likely use would be for board vendors wanting to test RAM chips from various vendors and of different capacities. Most SBCs use socketed eMMC chips available in various capacities. Pine64 and Odroid's eMMCs are compatible, at least, and live on a tiny little board you can swap out. I don't see the cost and complexity as being worth it, though. Just stuff the things full of RAM, have lower capacity options, and solder it - same as we see today. Yes, it's nice on paper to swap the RAM out, but I guarantee these sockets aren't cheap, and for something that's used once or twice, eh. Not worth the hassle... I like things that are easily repaired, but I also don't see a huge wave of ARM SBC RAM failures. They're already repairable, it just requires hot air rework and a bit more skill than swapping a DIMM.
- ClumsyPilot 5y ago
  "They're already repairable, it just requires hot air rework and a bit more skill than swapping a DIMM." Where do I find people who can do that? I google 'electronics repair London' and all I get are little shops where a dude with a screwdriver might replace a RAM stick, which I can do myself too! If I search for 'hot air rework' I get people trying to sell me kit. If an engineer can't find a place for such repair in the largest megacity on the continent, what hope is there for an average Joe? Also for chromebooks and crapbook worth $200-$300, how is that rare person going to charge for his time?
  - sokoloff 5y ago
    Your last point explains your former difficulty. There’s no retail willingness to pay, but a lot of willingness to inquire and waste someone’s time. Start with an in-country PCBA firm; they’re likely to have someone or know someone. Alternatively, inquire on an enthusiast forum (eevblog) or talk to your local Ham radio club. The same reason no one is advertising this skill to retail buyers of $200 electronics is the reason to not include a spurious $2-4 socket.
    - 5y ago
NovemberWhiskey 5y ago
That's not an interposer; an interposer is a device that sits between a device and a board and breaks out the interface so that it can be probed with a logic analyzer or timing measurement equipment or something. This looks more like a test fixture socket - those things cost more than the entire SBC does - so this seems more like a proof-of-concept rather than anything practical right now.
- wildzzz 5y ago
  An interposer doesn't have to have any breakout pads or pins. It just needs to sit between a board and component. It can serve as a breakout for components that may or may not be compatible with the footprint on the board or may not break anything out at all. I've used one to substitute a much cheaper FPGA in for our very expensive one on the development prototype. We didn't need all the features while sitting on a test bench so we saved ourselves some money until a production unit could be our dev platform. We had a few breakouts on the board of some signals that were difficult to access elsewhere but most just routed right through the interposer. We also developed another interposer that replaced a bunch of deadbug components to prevent rework from occuring due to poorly placed deadbugs. There was enough money to get a little card made but not enough to respin the whole board with the wishlist of other changes we wanted to make.
  - colejohnson66 5y ago
    To me, an interposer implies something that modifies the form factor, which this doesn’t. For desktop processors, the interposer takes the ultra fine pitch die and turns it into something that an LGA/PGA socket can take.
userbinator 5y ago
This is... not really news? Yes, BGA sockets exist. Device programmers and development/evaluation boards often have them. Unfortunately they are not cheap, even direct-from-China: https://siredatech.en.made-in-china.com/product/oSUJIjpOfwYD/China-BGA96-DDR3X16-DRAM-Socket-Adapter-PCR-Contact-Thin-Type.html https://siredatech.en.made-in-china.com/product/oSUJIjpOfwYD...
- kurthr 5y ago
  I guess maybe they could be made at more reasonable pricing in volume? But you're right. I've needed to have small 100 BGA sockets before and typical pricing of non-standard parts was $2k for 4 with a $1k setup fee.
metadat 5y ago
The GDPR popup on this site is pure dark pattern, try saying "no do not sell my data" and the next prompt auto-selects "yes sell my data" with a default button of "Allow". What Fucking Trash. For anyone who desires reading TFA without the crap salad sando: https://web.archive.org/web/20220421034027/https://www.cnx-software.com/2022/04/21/bga-socket-allows-ram-upgrades-on-sbcs/ https://web.archive.org/web/20220421034027/https://www.cnx-s... https://archive.ph/180ug https://archive.ph/180ug
deleted 5y ago
[deleted]
imtringued 5y ago
As others have said it would be more productive to just support standard PC mainboard standards like DDR3 over SO-DIMM.
zerohp 5y ago
Part of my job involves working with engineering sample SoCs on development and characterization boards. I've seen just about every kind of socket and connector you can imagine but I've never seen a BGA socket that is reliable enough to use in a normal machine. They would never pass qualification use in a typical laptop.
sschueller 5y ago
I don't think the socket is even the issues these days. The new Mac Studio has M.2 style slots but they are useless as apple locks it all down in Software.

31 points by zdw 5y ago

eternityforest 5y ago

Wow, that's awesome. This kind of thing could possibly make Chromebooks and the like repairable.

Syonyk 5y ago
What prevents you from repairing them now, exactly? Hot air rework stations have come down dramatically in cost, and there's no shortage of videos talking about how to do it. Try a few scrap bits before working on something expensive... It's nice to be able to swap things out with sockets, and you'll generally find me coming down on the side of repairability, but it exists with a variety of other considerations, and something that is less repairable, but also far less likely to fail in the first place, may be a better option. Also, I rather like the fact that soldered on RAM makes things like coldboot attacks a lot harder to pull off if you're using trusted boot. Heavy use of adhesives is certainly a problem, but I just can't get that worked up over soldered on RAM.
- ClumsyPilot 5y ago
  I don't have a garage to keep equipment that I will use once in 3 years, I don't have scraps to resolder and that's probably true for most people. For whatever reason a real repairshop is a lot harder to find than a laundrette - I was looking for one to fix a GPU, and I could not find one.
  - colejohnson66 5y ago
    These sockets cost $60 a piece.[0] Four of them alone is already ~$250. Add manufacturer markup, and you’re looking at an extra $300 to the consumer. If manufacturers want to make RAM replaceable, they should be putting SO-DIMM slots (which cost single digits),[1] not BGA sockets. After all, the average consumer is more likely to know how to procure RAM sticks than raw BGA RAM from DigiKey, Mouser, etc. [0]: https://www.aliexpress.com/item/1005001841972537.html https://www.aliexpress.com/item/1005001841972537.html [1]: https://www.digikey.com/en/products/detail/10033854-052FSLF/1001323 https://www.digikey.com/en/products/detail/10033854-052FSLF/...
- Ekaros 5y ago
  When I think about it it could certainly make layman repairing them cheaper. But I'm not sure if it really would chance too much with professional work, the parts and labour time would still be about the same or in same magnitude. And how often does RAM fail anyway? Or if it needs to be upgraded what about other parts?
- eternityforest 5y ago
  Even replacing an 0805 is a pretty significant challenge. I have no idea how people do BGAs with anything but a pick and place. Plus, without x-rays, how do you know you got it right? There's a lot of ways something can have a weak joint that isn't immediately noticeable. And, unless you have CNC equipment the result is more art than science, the quality depends largely on your hands. I wouldn't trust a device that had been repaired by anyone but an experienced pro, seeing as how these devices(along with phones) are the cornerstones of modern life.
  - colejohnson66 5y ago
    What I've seen is: use a microscope is used to align the new part with the silkscreen outline. Get it good enough and turn on the heat. The part will self align as the solder melts.
    - BizarroLand 5y ago
      Which is fine for single item repairs or upgrades where the person doing the work is tech savvy and all parties are will to accept the loss of a functional device in case something goes awry. (Which, admittedly, is rare, but you have to take the liability on yourself every time). Something like that is entirely non-feasible for mass manufacturing of parts with any guarantee of quality though.

Syonyk 5y ago

> While it looks neat, I’m not convinced we’ll see barebone single board computers where users can insert their own eMMC flash and RAM any time soon, since it would likely add to the overall costs. A more likely use would be for board vendors wanting to test RAM chips from various vendors and of different capacities. Most SBCs use socketed eMMC chips available in various capacities. Pine64 and Odroid's eMMCs are compatible, at least, and live on a tiny little board you can swap out. I don't see the cost and complexity as being worth it, though. Just stuff the things full of RAM, have lower capacity options, and solder it - same as we see today. Yes, it's nice on paper to swap the RAM out, but I guarantee these sockets aren't cheap, and for something that's used once or twice, eh. Not worth the hassle... I like things that are easily repaired, but I also don't see a huge wave of ARM SBC RAM failures. They're already repairable, it just requires hot air rework and a bit more skill than swapping a DIMM.

ClumsyPilot 5y ago
"They're already repairable, it just requires hot air rework and a bit more skill than swapping a DIMM." Where do I find people who can do that? I google 'electronics repair London' and all I get are little shops where a dude with a screwdriver might replace a RAM stick, which I can do myself too! If I search for 'hot air rework' I get people trying to sell me kit. If an engineer can't find a place for such repair in the largest megacity on the continent, what hope is there for an average Joe? Also for chromebooks and crapbook worth $200-$300, how is that rare person going to charge for his time?
- sokoloff 5y ago
  Your last point explains your former difficulty. There’s no retail willingness to pay, but a lot of willingness to inquire and waste someone’s time. Start with an in-country PCBA firm; they’re likely to have someone or know someone. Alternatively, inquire on an enthusiast forum (eevblog) or talk to your local Ham radio club. The same reason no one is advertising this skill to retail buyers of $200 electronics is the reason to not include a spurious $2-4 socket.
  - 5y ago

NovemberWhiskey 5y ago

That's not an interposer; an interposer is a device that sits between a device and a board and breaks out the interface so that it can be probed with a logic analyzer or timing measurement equipment or something. This looks more like a test fixture socket - those things cost more than the entire SBC does - so this seems more like a proof-of-concept rather than anything practical right now.

wildzzz 5y ago
An interposer doesn't have to have any breakout pads or pins. It just needs to sit between a board and component. It can serve as a breakout for components that may or may not be compatible with the footprint on the board or may not break anything out at all. I've used one to substitute a much cheaper FPGA in for our very expensive one on the development prototype. We didn't need all the features while sitting on a test bench so we saved ourselves some money until a production unit could be our dev platform. We had a few breakouts on the board of some signals that were difficult to access elsewhere but most just routed right through the interposer. We also developed another interposer that replaced a bunch of deadbug components to prevent rework from occuring due to poorly placed deadbugs. There was enough money to get a little card made but not enough to respin the whole board with the wishlist of other changes we wanted to make.
- colejohnson66 5y ago
  To me, an interposer implies something that modifies the form factor, which this doesn’t. For desktop processors, the interposer takes the ultra fine pitch die and turns it into something that an LGA/PGA socket can take.

userbinator 5y ago

This is... not really news? Yes, BGA sockets exist. Device programmers and development/evaluation boards often have them. Unfortunately they are not cheap, even direct-from-China: https://siredatech.en.made-in-china.com/product/oSUJIjpOfwYD/China-BGA96-DDR3X16-DRAM-Socket-Adapter-PCR-Contact-Thin-Type.html https://siredatech.en.made-in-china.com/product/oSUJIjpOfwYD...

kurthr 5y ago
I guess maybe they could be made at more reasonable pricing in volume? But you're right. I've needed to have small 100 BGA sockets before and typical pricing of non-standard parts was $2k for 4 with a $1k setup fee.

metadat 5y ago

The GDPR popup on this site is pure dark pattern, try saying "no do not sell my data" and the next prompt auto-selects "yes sell my data" with a default button of "Allow". What Fucking Trash. For anyone who desires reading TFA without the crap salad sando: https://web.archive.org/web/20220421034027/https://www.cnx-software.com/2022/04/21/bga-socket-allows-ram-upgrades-on-sbcs/ https://web.archive.org/web/20220421034027/https://www.cnx-s... https://archive.ph/180ug https://archive.ph/180ug

deleted 5y ago

[deleted]

imtringued 5y ago

As others have said it would be more productive to just support standard PC mainboard standards like DDR3 over SO-DIMM.

zerohp 5y ago

Part of my job involves working with engineering sample SoCs on development and characterization boards. I've seen just about every kind of socket and connector you can imagine but I've never seen a BGA socket that is reliable enough to use in a normal machine. They would never pass qualification use in a typical laptop.

sschueller 5y ago

I don't think the socket is even the issues these days. The new Mac Studio has M.2 style slots but they are useless as apple locks it all down in Software.