4 ms·

There's still plenty of reason to use discontinued components in DIY. And that reason is the form of the component's package. This is a problem for me when bui

There's still plenty of reason to use discontinued components in DIY. And that reason is the form of the component's package. This is a problem for me when building high end audio circuits. A lot of the modern components are only available in surface mount forms. I find this with matched transistor packages. Like a matched quad. There are modern components, like AD's MAT14 [1], but if you are building your own circuits and using through hole components your ONLY choice is discontinued components. They simply are not made in a through hole package anymore. At some point I'll be forced to move to surface mount, but at the moment getting old components is a lot easier. And those old components are as good as the new ones. Just different packages. If anyone knows of a modern precision matched quad like the MAT14, but in a traditional package, please reply with the component! [1] http://www.analog.com/media/en/technical-documentation/data-sheets/MAT14.pdf http://www.analog.com/media/en/technical-documentation/data-...

pmorici 10y ago
I disagree. Using a stencil and paste with a cheap toaster oven is easier to make high quality boards than with PTH and an iron. It's fast and almost always comes out great.
- retrogradeorbit 10y ago
  "easier". Just pull apart a toaster oven. Reconfigure it. Rewire it. Get some paste. Make a stencil. You know. Easy peasy. Get the software. Learn how to use it. Get the stencils printing. Easy. Oh, you've got registration problems. Come on! Its easy! So much easier than spending one minute ordering a through hole component. You see, its not actually "easier". Its "easier" to you because you already have the equipment and are already doing it. Hey! I already know this! This is easy!
  - pmorici 10y ago
    Don't knock it till you try it. You don't need to modify your toaster oven or any of that non-sense. I got a cheap $25 of Amazon and just use a stop watch and the toaster dial to set the temp by hand. There is really nothing to learn. Also ordering a stencil is just as simple as ordering PCBs now with the OSHStencil service.
    - retrogradeorbit 10y ago
      Don't get me wrong. At some point I'm definitely going to get into it. Get a SMD workstation proper. I'm just getting ranty with you saying its "easier". The word is so often abused today. It's easier now to order the ideal component. My original point is the day is fast approaching where there will be no more precision transistors in through hole. Even second hand or NOS. That's the day that getting an SMD setup will become easier for me. And then I'll get into it.
  - Kliment 10y ago
    Hey, I teach SMD soldering to absolute beginners, many of whom have never done ANY electronics. Within an hour and a half they have a working board with "advanced" components like QFNs and 0402 passives attached. Nobody goes without a working board. Only equipment needed is a pair of tweezers, a metal squeegee for paste deposition and a plain off-the-shelf $10 hotplate. No fancy anything. It's not a setup you'd use for high-volume production, but who gives a shit, it's enabling technology for hobbyists to use modern parts. I call it "surface mount electronics assembly for terrified beginners". If you can make it to an event I'm teaching at, I'll give you a free class, as you're EXACTLY the kind of person who would benefit most from seeing that there's a middle way between relying on increasingly unobtainium components and having to have a pile of fancy expensive stuff to be able to work at all.
    - moron4hire 10y ago
      How do you make the solder paste stencil? How do you make the PCB traces?
      - Kliment 10y ago
        You can get PCBs made very cheaply these days (dirtypcbs are an example of how cheap), and for $20-$30 you can have a sheetful of stencils lasered for you so this is mostly academic, but: PCBs: You can make PCBs by toner transfer, phototransfer, or milling, just like you'd make PCBs for through hole designs, except you don't need the precision drilling you'd need for through hole parts. The transfer methods need an etch stage, which you can do at home with fairly safe chemicals these days, see for instance http://quinndunki.com/blondihacks/?p=835 http://quinndunki.com/blondihacks/?p=835 for a very detailed tutorial. With a bit of care you can do double layer this way, but if you need lots of layer interconnections it's better to outsource PCB production. It's WAY easier to make PCBs for surface-mount designs at home because there is a lot less drilling involved. Stencils: If you have a laser cutter available, cut them from construction paper. They'll only work once, but you can make a bunch. If you have one of those label cutting machines, those work too. If you're etching your PCBs, you can etch stencils from thin copper sheet, using the same method. Another excellent material that is already the correct thickness is the wall of an aluminium beverage can. Toner transfer works well for these and can give excellent detail. Remember most have a plastic coating on both sides, so file the outside with the image until you get naked metal (check with a multimeter), transfer on that and then etch. You can get presensitized sheets of various metals for phototransfer as well. If you only have a handful of pads you can also plop bits of solder paste on with a toothpick. What about breadboards? The most common surface mount packages have breadboard adapter boards available. If there isn't one for the one you want, etch a board with a bunch of 2.54mm pitch pads along the edge (no holes, you want the board vertical so you have lots of breadboard space available). Stick any decoupling caps and pullup/pulldown resistors straight on the PCB so you don't clutter your breadboard with them, solder a bunch of header pins sideways, and there you go. You can put a label for the kind of part it is right into the copper. Again, unless you're in a hurry or the board is very simple you probably want to outsource PCB production. If you do that, get a stencil made as well. If you can combine a bunch of stencils into one file, they probably won't charge you any extra for a stencil the size of 5 boards compared to one the size of one, so with a bit of planning you can get stencils EXTREMELY cheaply. And you can do tens to hundreds of boards with a single stencil if you take good care of it. For alignment between stencil and board, if you're getting both manufactured for you, place two holes on opposite corners of the PCB that are exactly 3mm in size, and two identical holes in your stencil. Then you can use normal M3 bolts and nuts to fix them together, and it's super-easy to fine-tune alignment with the bolts in place but not yet tightened. There are pre-made stencils you can buy which have a selection of component footprints, so if you have say a little breakout board with just one difficult component you can apply paste to that with the stencil and do the others with the toothpick method or with a syringe dispenser (safety note: NEVER put solder paste in glass syringes, only use plastic ones). My point in all this? If you can make through-hole stuff you can make surface-mount stuff, and probably with less effort.
zerohp 10y ago
It doesn't take much time to learn to hand solder SMD. We teach 200 students to do it every semester at UIUC in the EE senior design lab. Our rule of thumb is that if it has pins that are not flush to the bottom of the package you can solder it with an iron. All but the smallest parts can be done with a cheap Weller. I soldered one project with paste, a toothpick to apply it, and an unmodified hot plate controlled by hand. No stencil needed. We have a proper oven but everyone hates using it.

pmorici 10y ago

I disagree. Using a stencil and paste with a cheap toaster oven is easier to make high quality boards than with PTH and an iron. It's fast and almost always comes out great.

retrogradeorbit 10y ago
"easier". Just pull apart a toaster oven. Reconfigure it. Rewire it. Get some paste. Make a stencil. You know. Easy peasy. Get the software. Learn how to use it. Get the stencils printing. Easy. Oh, you've got registration problems. Come on! Its easy! So much easier than spending one minute ordering a through hole component. You see, its not actually "easier". Its "easier" to you because you already have the equipment and are already doing it. Hey! I already know this! This is easy!
- pmorici 10y ago
  Don't knock it till you try it. You don't need to modify your toaster oven or any of that non-sense. I got a cheap $25 of Amazon and just use a stop watch and the toaster dial to set the temp by hand. There is really nothing to learn. Also ordering a stencil is just as simple as ordering PCBs now with the OSHStencil service.
  - retrogradeorbit 10y ago
    Don't get me wrong. At some point I'm definitely going to get into it. Get a SMD workstation proper. I'm just getting ranty with you saying its "easier". The word is so often abused today. It's easier now to order the ideal component. My original point is the day is fast approaching where there will be no more precision transistors in through hole. Even second hand or NOS. That's the day that getting an SMD setup will become easier for me. And then I'll get into it.
- Kliment 10y ago
  Hey, I teach SMD soldering to absolute beginners, many of whom have never done ANY electronics. Within an hour and a half they have a working board with "advanced" components like QFNs and 0402 passives attached. Nobody goes without a working board. Only equipment needed is a pair of tweezers, a metal squeegee for paste deposition and a plain off-the-shelf $10 hotplate. No fancy anything. It's not a setup you'd use for high-volume production, but who gives a shit, it's enabling technology for hobbyists to use modern parts. I call it "surface mount electronics assembly for terrified beginners". If you can make it to an event I'm teaching at, I'll give you a free class, as you're EXACTLY the kind of person who would benefit most from seeing that there's a middle way between relying on increasingly unobtainium components and having to have a pile of fancy expensive stuff to be able to work at all.
  - moron4hire 10y ago
    How do you make the solder paste stencil? How do you make the PCB traces?
    - Kliment 10y ago
      You can get PCBs made very cheaply these days (dirtypcbs are an example of how cheap), and for $20-$30 you can have a sheetful of stencils lasered for you so this is mostly academic, but: PCBs: You can make PCBs by toner transfer, phototransfer, or milling, just like you'd make PCBs for through hole designs, except you don't need the precision drilling you'd need for through hole parts. The transfer methods need an etch stage, which you can do at home with fairly safe chemicals these days, see for instance http://quinndunki.com/blondihacks/?p=835 http://quinndunki.com/blondihacks/?p=835 for a very detailed tutorial. With a bit of care you can do double layer this way, but if you need lots of layer interconnections it's better to outsource PCB production. It's WAY easier to make PCBs for surface-mount designs at home because there is a lot less drilling involved. Stencils: If you have a laser cutter available, cut them from construction paper. They'll only work once, but you can make a bunch. If you have one of those label cutting machines, those work too. If you're etching your PCBs, you can etch stencils from thin copper sheet, using the same method. Another excellent material that is already the correct thickness is the wall of an aluminium beverage can. Toner transfer works well for these and can give excellent detail. Remember most have a plastic coating on both sides, so file the outside with the image until you get naked metal (check with a multimeter), transfer on that and then etch. You can get presensitized sheets of various metals for phototransfer as well. If you only have a handful of pads you can also plop bits of solder paste on with a toothpick. What about breadboards? The most common surface mount packages have breadboard adapter boards available. If there isn't one for the one you want, etch a board with a bunch of 2.54mm pitch pads along the edge (no holes, you want the board vertical so you have lots of breadboard space available). Stick any decoupling caps and pullup/pulldown resistors straight on the PCB so you don't clutter your breadboard with them, solder a bunch of header pins sideways, and there you go. You can put a label for the kind of part it is right into the copper. Again, unless you're in a hurry or the board is very simple you probably want to outsource PCB production. If you do that, get a stencil made as well. If you can combine a bunch of stencils into one file, they probably won't charge you any extra for a stencil the size of 5 boards compared to one the size of one, so with a bit of planning you can get stencils EXTREMELY cheaply. And you can do tens to hundreds of boards with a single stencil if you take good care of it. For alignment between stencil and board, if you're getting both manufactured for you, place two holes on opposite corners of the PCB that are exactly 3mm in size, and two identical holes in your stencil. Then you can use normal M3 bolts and nuts to fix them together, and it's super-easy to fine-tune alignment with the bolts in place but not yet tightened. There are pre-made stencils you can buy which have a selection of component footprints, so if you have say a little breakout board with just one difficult component you can apply paste to that with the stencil and do the others with the toothpick method or with a syringe dispenser (safety note: NEVER put solder paste in glass syringes, only use plastic ones). My point in all this? If you can make through-hole stuff you can make surface-mount stuff, and probably with less effort.

zerohp 10y ago

It doesn't take much time to learn to hand solder SMD. We teach 200 students to do it every semester at UIUC in the EE senior design lab. Our rule of thumb is that if it has pins that are not flush to the bottom of the package you can solder it with an iron. All but the smallest parts can be done with a cheap Weller. I soldered one project with paste, a toothpick to apply it, and an unmodified hot plate controlled by hand. No stencil needed. We have a proper oven but everyone hates using it.