How do you design these days?
in [Design]
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From: Phil Hobbs on 1 Jan 2010 14:20 On 1/1/2010 2:18 PM, John Larkin wrote: > On Fri, 01 Jan 2010 13:40:32 -0500, Phil Hobbs > <pcdhSpamMeSenseless(a)electrooptical.net> wrote: > >> On 1/1/2010 1:10 PM, John Larkin wrote: >>> On Fri, 01 Jan 2010 11:28:56 -0500, Phil Hobbs >>> <pcdhSpamMeSenseless(a)electrooptical.net> wrote: >>> >>>> On 1/1/2010 10:20 AM, Fred Abse wrote: >>>>> On Fri, 01 Jan 2010 00:49:11 +0000, Jan Panteltje wrote: >>>>> >>>>>> It is 'bison kit', or translated 'Bison Glue'. >>>>> >>>>> What is the difference between a buffalo and a bison? >>>> >>>> Like "What's the difference between a Stoic and a Cynic? >>>> >>> >>> I couldn't care less. >>> >>> John >>> >> >> Snow a bit heavy, is it? ;) > > Cold means nothing to me. > > John > I thought you were one of those tropical types who freeze solid at 60 F. Cheers Phil Hobbs -- Dr Philip C D Hobbs Principal ElectroOptical Innovations 55 Orchard Rd Briarcliff Manor NY 10510 845-480-2058 hobbs at electrooptical dot net http://electrooptical.net
From: krw on 1 Jan 2010 14:20 On Thu, 31 Dec 2009 22:55:22 -0800 (PST), "miso(a)sushi.com" <miso(a)sushi.com> wrote: >On Dec 31, 7:43�pm, John Larkin ><jjlar...(a)highNOTlandTHIStechnologyPART.com> wrote: >> On Thu, 31 Dec 2009 19:28:42 -0800 (PST), "m...(a)sushi.com" >> >> >> >> <m...(a)sushi.com> wrote: >> >On Dec 31, 12:50�pm, Joerg <inva...(a)invalid.invalid> wrote: >> >> Phil Hobbs wrote: >> >> > On 12/30/2009 9:20 PM, Joerg wrote: >> >> >> RogerN wrote: >> >> >>> When I was in school components fit on solderless breadboards and we >> >> >>> made circuits using breadboards, power supplies, meters and >> >> >>> oscilloscopes. Many of today's components don't appear to be >> >> >>> breadboard friendly, so how is it done today? >> >> >> >> I even used bare thumbtacks on plywood for solder posts back then. >> >> >> >>> Is circuit design software and simulation good enough to go straight >> >> >>> to a PC board? Or do you use surface mount to breadboard adapters? Do >> >> >>> you still use a soldering Iron to solder or paste solder and an oven? >> >> >> >> In the professional world (product design) we go straight from >> >> >> simulation to schematic -> layout -> board fab -> assembly. No >> >> >> breadboards. >> >> >> >>> I'm wanting to tinker with some circuits but some chips I'm interested >> >> >>> in only comes in MSOP or other packages that look intimidating to >> >> >>> attempt to solder. >> >> >> >> Well, for hobbyists or one-off designs there is help but not very cheap: >> >> >> >>http://www.proto-advantage.com/store/images/PRODUCTS/PA0027_0.JPG >> >> >> >> This is the variety they have but I don't know this shop, just meant as >> >> >> an example: >> >> >> >>http://www.proto-advantage.com/store/index.php?cPath=2200 >> >> >> > _THE_ professional world? �Joerg, Joerg, you've been holed up in that >> >> > mountain lair of yours for too long. �;) >> >> >> Now, now, we do have a modern feed store in this here town whar we're >> >> gitten them alfalfa bales and all that, and they even use a computation >> >> machine :-) >> >> >> > Simulate the parts that simulators get right, do the rote stuff by rote, >> >> > but prototype the stuff you're not sure will work. �It's amazing the >> >> > amount of stuff you can learn in a short time from a dead-bug prototype. >> >> >> > If you're just talking about laying out boards for circuit prototypes, >> >> > then I agree--you might as well try a bit harder and get it right the >> >> > first time. �But trying out weird stuff, especially in mixed-technology >> >> > systems, really needs prototypes. >> >> >> Ok, I did build a breadboard for my first noise-critical fiber-optics >> >> front end but that was more because the client really wanted that done. >> >> I ended up not changing a thing on there and going straight to a >> >> multi-channel layout. Since it has digital delay controls with SPI and >> >> stuff it (almost) counts as mixed signal. >> >> >> > Besides, lots of my protos are actually small instruments that I build >> >> > in half a day and then use for years. � An example is the sub-Poissonian >> >> > current source and LNA I built for my tunnel junction work--very >> >> > specific, worked great for years, took a day all told to design and >> >> > build. �Good medicine. >> >> >> One-off things I also often build on experimental board. I am not a >> >> great friend of the dead-bug style, preferring Vector board with a >> >> ground plane. That's harder to find these days so I stocked up. Many >> >> things go into those little Pomona boxes that end up riding on the back >> >> of a coax connector. All good medicine, but at least I can put a shiny >> >> aluminum lid on it so the clients don't see the wire ball inside my probes. >> >> >> -- >> >> Regards, Joerg >> >> >>http://www.analogconsultants.com/ >> >> >> "gmail" domain blocked because of excessive spam. >> >> Use another domain or send PM. >> >> >Vector board is insanely priced. I buy it up at flea markets when I >> >find good deals and nibble out small pieces for circuits to conserve >> >it. I think if I had to pay real prices for vectorboard, I'd use the >> >on-line PCB manufacturers. �I dead bug too. >> >> Live bug is easier to visualize. And if you work on copperclad, you >> can bend ungrounded pins out horizontally and solder the groudable >> pins directly to the plane. >> >> Kapton tape is great, too, when working on copperclad. >> >> John > >The backwards pinout is an issue. I sharpie the pin numbers after I >mount the dead bug. Why are pin numbers an issue? You never probe from the backside of a board? The spatial transform is pretty ingrained in me and I spent a decade doing processor design (no PCB stuff).
From: qrk on 1 Jan 2010 14:23 On Thu, 31 Dec 2009 13:07:00 -0800, Joerg <invalid(a)invalid.invalid> wrote: >qrk wrote: > >[...] > >> These days, I have a zoom stereo microscope ($500), hot air plate for >> warming the board to 150 deg C ($155 + $30 in modifications), and a >> hot air station for soldering ($185). All equipment is cheap Chinese >> stuff which works fine for repair and prototyping small parts. Our >> labs are equiped with Metcal soldering irons which is the place not to >> skimp. I don't use solder paste on leadless packages as it is too hard >> to dispense on small pads (e.g. 8-lead 1.6 x 1.6 mm packages). Easier >> to apply a bump of solder to the PCB pad and coat the underbelly of >> the part with flux, then hot air solder. >> > >How do you get the flux back outta there? I use RMA flux. I usually don't clean it. I would need a jet cleaning system to get the flux out. A past assembly house had problems cleaning our boards which caused all sorts of problems with the water soluable flux they used. Messed up the ~100k impedance areas. They probably didn't maintain their wash solution is my guess.
From: krw on 1 Jan 2010 14:23 On Fri, 01 Jan 2010 07:20:48 -0800, Fred Abse <excretatauris(a)invalid.invalid> wrote: >On Thu, 31 Dec 2009 17:29:44 -0600, krw wrote: > >> "Whenever more than one person is involved in a screwup, blame will >> never be placed." > >Managers fix blame. Engineers fix the problem. ....and guess where the blame gets fixed and who gets credit for fixing the problem?
From: Phil Hobbs on 1 Jan 2010 14:24
On 1/1/2010 2:20 PM, krw wrote: > On Thu, 31 Dec 2009 22:55:22 -0800 (PST), "miso(a)sushi.com" > <miso(a)sushi.com> wrote: > >> On Dec 31, 7:43 pm, John Larkin >> <jjlar...(a)highNOTlandTHIStechnologyPART.com> wrote: >>> On Thu, 31 Dec 2009 19:28:42 -0800 (PST), "m...(a)sushi.com" >>> >>> >>> >>> <m...(a)sushi.com> wrote: >>>> On Dec 31, 12:50 pm, Joerg<inva...(a)invalid.invalid> wrote: >>>>> Phil Hobbs wrote: >>>>>> On 12/30/2009 9:20 PM, Joerg wrote: >>>>>>> RogerN wrote: >>>>>>>> When I was in school components fit on solderless breadboards and we >>>>>>>> made circuits using breadboards, power supplies, meters and >>>>>>>> oscilloscopes. Many of today's components don't appear to be >>>>>>>> breadboard friendly, so how is it done today? >>> >>>>>>> I even used bare thumbtacks on plywood for solder posts back then. >>> >>>>>>>> Is circuit design software and simulation good enough to go straight >>>>>>>> to a PC board? Or do you use surface mount to breadboard adapters? Do >>>>>>>> you still use a soldering Iron to solder or paste solder and an oven? >>> >>>>>>> In the professional world (product design) we go straight from >>>>>>> simulation to schematic -> layout -> board fab -> assembly. No >>>>>>> breadboards. >>> >>>>>>>> I'm wanting to tinker with some circuits but some chips I'm interested >>>>>>>> in only comes in MSOP or other packages that look intimidating to >>>>>>>> attempt to solder. >>> >>>>>>> Well, for hobbyists or one-off designs there is help but not very cheap: >>> >>>>>>> http://www.proto-advantage.com/store/images/PRODUCTS/PA0027_0.JPG >>> >>>>>>> This is the variety they have but I don't know this shop, just meant as >>>>>>> an example: >>> >>>>>>> http://www.proto-advantage.com/store/index.php?cPath=2200 >>> >>>>>> _THE_ professional world? Joerg, Joerg, you've been holed up in that >>>>>> mountain lair of yours for too long. ;) >>> >>>>> Now, now, we do have a modern feed store in this here town whar we're >>>>> gitten them alfalfa bales and all that, and they even use a computation >>>>> machine :-) >>> >>>>>> Simulate the parts that simulators get right, do the rote stuff by rote, >>>>>> but prototype the stuff you're not sure will work. It's amazing the >>>>>> amount of stuff you can learn in a short time from a dead-bug prototype. >>> >>>>>> If you're just talking about laying out boards for circuit prototypes, >>>>>> then I agree--you might as well try a bit harder and get it right the >>>>>> first time. But trying out weird stuff, especially in mixed-technology >>>>>> systems, really needs prototypes. >>> >>>>> Ok, I did build a breadboard for my first noise-critical fiber-optics >>>>> front end but that was more because the client really wanted that done. >>>>> I ended up not changing a thing on there and going straight to a >>>>> multi-channel layout. Since it has digital delay controls with SPI and >>>>> stuff it (almost) counts as mixed signal. >>> >>>>>> Besides, lots of my protos are actually small instruments that I build >>>>>> in half a day and then use for years. An example is the sub-Poissonian >>>>>> current source and LNA I built for my tunnel junction work--very >>>>>> specific, worked great for years, took a day all told to design and >>>>>> build. Good medicine. >>> >>>>> One-off things I also often build on experimental board. I am not a >>>>> great friend of the dead-bug style, preferring Vector board with a >>>>> ground plane. That's harder to find these days so I stocked up. Many >>>>> things go into those little Pomona boxes that end up riding on the back >>>>> of a coax connector. All good medicine, but at least I can put a shiny >>>>> aluminum lid on it so the clients don't see the wire ball inside my probes. >>> >>>>> -- >>>>> Regards, Joerg >>> >>>>> http://www.analogconsultants.com/ >>> >>>>> "gmail" domain blocked because of excessive spam. >>>>> Use another domain or send PM. >>> >>>> Vector board is insanely priced. I buy it up at flea markets when I >>>> find good deals and nibble out small pieces for circuits to conserve >>>> it. I think if I had to pay real prices for vectorboard, I'd use the >>>> on-line PCB manufacturers. I dead bug too. >>> >>> Live bug is easier to visualize. And if you work on copperclad, you >>> can bend ungrounded pins out horizontally and solder the groudable >>> pins directly to the plane. >>> >>> Kapton tape is great, too, when working on copperclad. >>> >>> John >> >> The backwards pinout is an issue. I sharpie the pin numbers after I >> mount the dead bug. > > Why are pin numbers an issue? You never probe from the backside of a > board? The spatial transform is pretty ingrained in me and I spent a > decade doing processor design (no PCB stuff). I usually put a gouge on the bottom of the package to match the mark on the top, so I can tell where pin 1 is. At that point it's no problem, and I almost never break pins. Dead bugs rule. Cheers Phil Hobbs -- Dr Philip C D Hobbs Principal ElectroOptical Innovations 55 Orchard Rd Briarcliff Manor NY 10510 845-480-2058 hobbs at electrooptical dot net http://electrooptical.net |