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Surface Mount Assembly Training courses - worth taking?

Discussion in 'Electronic Basics' started by [email protected], Oct 10, 2003.

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  1. Guest

    Hello. I'm new to electronics and I was wondering if taking some
    training in surface mount assembly techniques is something worth
    doing.

    There is a local college that offers a surface mount assembly course
    that costs about $300 for 21 hours of instruction. There are
    also some online video courses for $99. I've also seen a few
    interactive CDs for $185 or DVD video courses for about $99.

    What is everyone's opinion about those options? Are there any books
    I can buy that are just as effective as a training course?

    Also, what surface mount equipment would you recommend that I
    get? I'll like to buy some inexpensive equipment while I'm learning
    how to build some simple surface mount component based kits.

    Thanks in advance.
     
  2. happyhobit

    happyhobit Guest

    If your goal is to get a job, YES. If it's to learn something, NO.

    There's not much you can't find in the internet. The "How To's" of SMT and
    SMD are everywhere. "Google is your Friend" Do a Google search for, SMT
    + SMD + tools + techniques (I got 1090 matches). You can buy kits of junk
    Surface Mount Devices to practice on.

    If you have an extra $300 go for it, otherwise teach yourself. I taught
    myself mictocomputers 25 years ago.

    All formal education provides is a certificate that may impress a boss who
    doesn't know how to do it.


    "Nothing worth learning can be taught", Oscar Wilde


    Jay
     
  3. Guest

    Thanks for the reply. I did a google search and found many links.
    I've spoken to a couple of technicians and engineers who were SMT
    self taught.

    There are several online courses and books on SMT assembly, the
    cost is about $100.

    Do you think buying a $50 or $100 book is worth it? Are there a few
    important details about SMT assembly that you need to know that a book
    can list?
     
  4. Guest

    Hi, it's me, the Newbie, again. Thanks for the google search string, I
    used it and several good links popped up. I guess this is an example
    of how knowing about a topic can be enormously helpful in finding out
    even more about that topic. Not knowing much about SMT, I had used
    variants of "surface mount assembly" as a search string and while
    there were many hits, they were mostly oriented towards SMT assembly
    courses. The string you suggested resulted in web pages meant to teach
    hobbyists the ways of SMT assembly, just what I was looking for.
    It looks like we're both old timers. ;->

    A very long time ago a friend and I built an S-100 memory board from
    a kit. It was a 32K SD Sales Expandorram. I think it cost $400 and the
    machine is still in my basement.
     
  5. happyhobit

    happyhobit Guest

    My first computer was a Netronics ELF 2 I built back in 1978. I don't
    remember what it cost, something ridiculous I'm sure. It came with 256 Bytes
    of memory and I added a 4k memory board, 32 1k by 1 chips.

    I do remember that my first floppy drive cost $300. Single density (360K)
    double sided. I patched the OS of an 'Ohio Scientific' so I could access the
    two sides by pressing 'Ctrl'1 or 'Ctrl'2.

    Ah, the good old days. Still got them in my basement.

    I recently started playing with AVR microcontrollers, 128 bytes Eprom, 128
    bytes SRAM, 2k of flash memory for $3.50.

    Ah, the good new days.


    Jay

    ..
     
  6. Guest

    I've been looking at the TI MSP430 series of micocontrollers, which is
    what led me to investigate SMT assembly. The funny part is that the
    largest MSP model runs at 6Mhz, has something like 48K of flash and
    10K of sram for about $6. The first Z80 machine I bought ran at 2Mhz,
    started out with 32K of ram and had a 90K floppy (the old Northstar
    hard sector drive) and cost thousands of dollars. You're right, these
    are the good old days.

    BTW, are there any books on SMT techniques that would be useful or
    would learning from a web page be sufficient? I've found a lot of web
    pages that describe SMT assembly, is there anything about SMT that a
    book would cover that a web page like the ones below might miss?

    http://www.norcalqrp.com/smt/vk33msmt.htm

    http://www.twyman.org.uk/PCB-Techniques/index-frame.htm
     
  7. happyhobit

    happyhobit Guest

    Well I'm a hands on kind of guy.

    I knew a guy back in the early 80's who was going to buy the latest and
    greatest computer as soon as it came out. Every time I saw him he would talk
    about another computer he heard of that he was going to buy as soon as it
    came out.

    I bought 3 books. One on 8080 assembly, one on 6502 assembly and one on 6800
    assembly. (There was no Internet back then) Then I built this computer and
    bought that computer, soldered kits, built wire-wrap boards, wrote programs
    in 1802 assembly, 6502 assembly, basic, forth, disassembled operating
    systems, made a lot of mistakes and learned a LOT.

    I don't know if that guy ever bought a computer, probably not, but I
    parlayed a lot of tinkering and a Journeyman's card into a career in
    electronics and had a lot of fun along the way.

    Personally I'd get;
    A loupe and a table mounted lamp / magnifying glass.
    Some de-soldering braid,
    A Solder Sucker,
    A Small soldering Iron, 30 Watt with a 1/16 tip,
    A flux pen (a felt tip pen with flux.),
    A SMT soldering kit http://www.cpcares.com/ESM200K.html for $22 ( I'm Cheep)
    ( Or one of the $60 to $100 "SMT soldering kits" if you're not.)

    And melt some solder

    I looked it the sites you posted and they provide the basics. After that it'
    s a mater of practice, hands on. Of course that's just my opinion and
    everybody has one.


    Jay

    P.S. I don't know what applications you have in mind for a microcontrollers,
    but take a look at AVR.
     
  8. happyhobit

    happyhobit Guest

  9. Guest

    Thanks for checking over those web pages, it's good to know that
    someone experienced thinks those pages are on the right track. Over
    the past few days I've been reading those web pages, along with
    dozens of other threads and web pages on SMD assembly and test
    equipment.

    One web page suggested getting the kind of magnifying eyeglasses that
    watchmakers or jewelers use but I may go with one of those third hand
    clamps with a built in and position adjustable magnifying glass. I saw
    one at a surplus electronics store today for $5. It was a little light
    on construction and the magnifying glass only had a plastic lens so I
    think I'll try to find a better one.

    I've found a few interesting newsgroup threads about SMD assembly,
    which I've pasted to the end of this post. I think I'll see if I can
    find the "hoof" tip mentioned in the threads.

    ........................

    What you need is FLUX - I solder these kind of things with a moderate
    sized iron, regular (0.028) solder, and flux.

    Get a corner pin located, tack solder, locate other corner, tack
    solder
    (just put a little solder on the tip of you iron) -flux the pins on a
    side you didn't tack, and then drag the tip and solder along, repeat,
    and clean with flux remover -I learned this from a lady who did
    commercial rework on SMD's for a lving - I've put 0.5mm parts on with
    not problem pretty quick. Now a 201 resitor or cap is another story -
    I'm a tombstoner. Anyone know how to do these things well?

    ..............
    Andrew,

    I totally agree with what you've said below. I used to do i486 and
    Pentium mainboard rework by the palet before and this is exactly what
    we
    do from 8 pin SOIC to 208 pin QFPs. Flux, right heat, medium soldering
    iron tip (small one don't deliver that much heat) and 63/37 solder
    will
    do the job. The result is almost like that of the production ones
    after
    cleaning up the excess flux.

    As for the braid, I use it for stubborn solder bridges and I don't
    recommend the shotgun approach of filling everything with solder then
    clean up with the braid as what some has suggested. You'll end up with
    misaligned pins and damaged ugly board.

    For SMT resistors and caps, if you have two irons then just put one
    tip
    on each end and lift or you can buy those fancy tips.

    PJ
    ..........

    You'll find there are several techniques. From trial & error (and
    later
    a little advice from a rework tech at Intel), here's mine for working
    with 0.5mm pitch, 128-pin SMDs:

    * Flux the pads
    * Position the piece
    * *Very light* downward pressure to prevent shifting
    * Place a small bit of solder on the iron tip
    * Tack one corner pin
    * Ensure device is positioned properly
    * Tack opposite corner

    * Flux the pins
    * Place a small amount of solder on the iron
    * Stroke each pin away from the body toward the tip
    - Flux will help the solder wick around/under the pin
    - The stroke guides solder balls to the tip of the foot
    - You can do several pins at once if the tip is wide
    * Cleanup with solder braid

    Some key tricks:

    - I didn't have good success with the "blob it on, run to the end of
    the
    row" technique at lower temperatures. The pin-by-pin technique is a
    little more tedious, but more consistent with fine-pitch devices.

    - *Don't* use a very fine tip. I started with a narrow-tip 1/32"
    "screwdriver" tip, but discovered that it had problems transferring
    enough heat on larger packages. A conical 1/32" screwdriver tip
    worked
    much better, as did a common 1/8" conical screwdriver tip.

    - Good tinning on the tip is key, since you want the solder to flow
    off
    smoothly, not ball up and come off in globs. If you do many, you may
    find yourself replacing the tip regularly. There are good tricks to
    prolonging the life of the tip's tinning - search google for
    'soldering
    iron tip tinning'. Basically, cover the tip in solder when it's idle
    in
    the stand to prevent oxidation; wipe it off before you start a joint,
    not after.

    - You don't need thin-gauge solder, since you're applying it to the
    tip,
    not the pad. Some folks prefer paste solder, but I've had better
    success with wire solder.

    - Use a flux pen, like MG Chemicals' (Fry's Electronics). It goes on
    thin, applies easily, makes less mess.

    - Flux is your best friend here. You're bound to get bridges or
    solder
    globs behind pins. They can be coaxed out with flux, an outward
    stroking motion, and braid to remove excess.

    - Rather than using a stereo microscope, I use a jeweller's magnifying
    visor in the strongest strength to do the soldering, with a jeweller's
    loupe for inspection. Micromark.com sells both, and the loupe
    attaches
    to the visor.

    - Bright lighting is good. I use a small 20W halogen desk lamp on an
    arm to position it close to the work and move it around to minimize
    shadows on the pin edges.

    - Use a temp controlled iron, set to ~220 C. Check the specs on your
    parts for maximum soldering temperature and time tolerances.

    - If you'd like some practice, check out the dummy parts at
    http://www.practicalcomponents.com and practice first on a spare PCB.
    They supply exact mechanical parts for about $1 each - worthwhile if
    your live parts are $10-$30.
    ......................
    Metcal makes a "hoof tip" just for this. It looks like a medium-small
    conical tip that has a flat on one side. When you put solder on it, a
    nice juicy blob parks on the flat, and as you run the pointy tip down
    the row of fluxed pins, the solder slurps off onto each pin in just
    the right amount. My people solder 240-pin FPGAs in just a minute or
    two this way.

    If anybody is doing any serious amount of soldering/desoldering,
    Metcal gear is well worth it.

    John
    ................
    I'm using this thing (its equivalent from Weller) to solder 100 pin
    FPGAs
    and it does work. But you need flux to prevent solder from spilling
    over
    multiple pins and shorting them together. I also found that this works
    better
    with higher temperature, I do it at around 400C.

    Soldered in about 600 over the years this way.

    Siol
    ...............
    Oh, one other tip: Metcal makes two hoofers, big and small, and my
    people prefer the big one. It holds more solder and works great on the
    fine-pitch parts.

    All this stuff is counter-intuitive.
    ...............

    Ever heard of rework paste? just clean up the pads and tin them paint
    on
    the rework paste then place the component on the pads, you can then
    either
    do every pin with your iron or use a hot air pen to fix the device
    afterwards clean up with some isoprop and a brush, Ive fitted loads od
    chips
    with this method and I might say with pin spacings of much less that
    1mm
    ,,,,,,, good luck
    ..........
     
  10. Guest

    Thanks again. I finally got around to checking out the AVR line from
    Atmel. When we last looked at the AVR line over a year ago, the TI MSP
    product lineup was much broader, cheaper and used less power. Our main
    requirement was extremely low power consumption and the app had to be
    very low cost, so the MSP won out.

    However, I see that Atmel has added a number of parts at both the low
    end and high end. I'll have to get the AVR datasheets and do a more
    detailed comparison and see how the new parts fit our app.

    From a quick check, it looks like the AVR parts can run at higher
    clock speeds but the MSP parts can have more peripherals on board. So
    the choice isn't as clear cut as it was a year ago.
     
  11. nobody

    nobody Guest

    Thanks again. I finally got around to checking out the AVR line from
    Atmel. When we last looked at the AVR line over a year ago, the TI MSP
    product lineup was much broader, cheaper and used less power. Our main
    requirement was extremely low power consumption and the app had to be
    very low cost, so the MSP won out.

    However, I see that Atmel has added a number of parts at both the low
    end and high end. I'll have to get the AVR datasheets and do a more
    detailed comparison and see how the new parts fit our app.

    From a quick check, it looks like the AVR parts can run at higher
    clock speeds but the MSP parts can have more peripherals on board. So
    the choice isn't as clear cut as it was a year ago.
     
  12. nobody

    nobody Guest

    Thanks for checking over those web pages, it's good to know that
    someone experienced thinks those pages are on the right track. Over
    the past few days I've been reading those web pages, along with
    dozens of other threads and web pages on SMD assembly and test
    equipment.

    One web page suggested getting the kind of magnifying eyeglasses that
    watchmakers or jewelers use but I may go with one of those third hand
    clamps with a built in and position adjustable magnifying glass. I saw
    one at a surplus electronics store today for $5. It was a little light
    on construction and the magnifying glass only had a plastic lens so I
    think I'll try to find a better one.

    I've found a few interesting newsgroup threads about SMD assembly,
    which I've pasted to the end of this post. I think I'll see if I can
    find the "hoof" tip mentioned in the threads.

    ........................

    What you need is FLUX - I solder these kind of things with a moderate
    sized iron, regular (0.028) solder, and flux.

    Get a corner pin located, tack solder, locate other corner, tack
    solder
    (just put a little solder on the tip of you iron) -flux the pins on a
    side you didn't tack, and then drag the tip and solder along, repeat,
    and clean with flux remover -I learned this from a lady who did
    commercial rework on SMD's for a lving - I've put 0.5mm parts on with
    not problem pretty quick. Now a 201 resitor or cap is another story -
    I'm a tombstoner. Anyone know how to do these things well?

    ..............
    Andrew,

    I totally agree with what you've said below. I used to do i486 and
    Pentium mainboard rework by the palet before and this is exactly what
    we
    do from 8 pin SOIC to 208 pin QFPs. Flux, right heat, medium soldering
    iron tip (small one don't deliver that much heat) and 63/37 solder
    will
    do the job. The result is almost like that of the production ones
    after
    cleaning up the excess flux.

    As for the braid, I use it for stubborn solder bridges and I don't
    recommend the shotgun approach of filling everything with solder then
    clean up with the braid as what some has suggested. You'll end up with
    misaligned pins and damaged ugly board.

    For SMT resistors and caps, if you have two irons then just put one
    tip
    on each end and lift or you can buy those fancy tips.

    PJ
    ..........

    You'll find there are several techniques. From trial & error (and
    later
    a little advice from a rework tech at Intel), here's mine for working
    with 0.5mm pitch, 128-pin SMDs:

    * Flux the pads
    * Position the piece
    * *Very light* downward pressure to prevent shifting
    * Place a small bit of solder on the iron tip
    * Tack one corner pin
    * Ensure device is positioned properly
    * Tack opposite corner

    * Flux the pins
    * Place a small amount of solder on the iron
    * Stroke each pin away from the body toward the tip
    - Flux will help the solder wick around/under the pin
    - The stroke guides solder balls to the tip of the foot
    - You can do several pins at once if the tip is wide
    * Cleanup with solder braid

    Some key tricks:

    - I didn't have good success with the "blob it on, run to the end of
    the
    row" technique at lower temperatures. The pin-by-pin technique is a
    little more tedious, but more consistent with fine-pitch devices.

    - *Don't* use a very fine tip. I started with a narrow-tip 1/32"
    "screwdriver" tip, but discovered that it had problems transferring
    enough heat on larger packages. A conical 1/32" screwdriver tip
    worked
    much better, as did a common 1/8" conical screwdriver tip.

    - Good tinning on the tip is key, since you want the solder to flow
    off
    smoothly, not ball up and come off in globs. If you do many, you may
    find yourself replacing the tip regularly. There are good tricks to
    prolonging the life of the tip's tinning - search google for
    'soldering
    iron tip tinning'. Basically, cover the tip in solder when it's idle
    in
    the stand to prevent oxidation; wipe it off before you start a joint,
    not after.

    - You don't need thin-gauge solder, since you're applying it to the
    tip,
    not the pad. Some folks prefer paste solder, but I've had better
    success with wire solder.

    - Use a flux pen, like MG Chemicals' (Fry's Electronics). It goes on
    thin, applies easily, makes less mess.

    - Flux is your best friend here. You're bound to get bridges or
    solder
    globs behind pins. They can be coaxed out with flux, an outward
    stroking motion, and braid to remove excess.

    - Rather than using a stereo microscope, I use a jeweller's magnifying
    visor in the strongest strength to do the soldering, with a jeweller's
    loupe for inspection. Micromark.com sells both, and the loupe
    attaches
    to the visor.

    - Bright lighting is good. I use a small 20W halogen desk lamp on an
    arm to position it close to the work and move it around to minimize
    shadows on the pin edges.

    - Use a temp controlled iron, set to ~220 C. Check the specs on your
    parts for maximum soldering temperature and time tolerances.

    - If you'd like some practice, check out the dummy parts at
    http://www.practicalcomponents.com and practice first on a spare PCB.
    They supply exact mechanical parts for about $1 each - worthwhile if
    your live parts are $10-$30.
    ......................
    Metcal makes a "hoof tip" just for this. It looks like a medium-small
    conical tip that has a flat on one side. When you put solder on it, a
    nice juicy blob parks on the flat, and as you run the pointy tip down
    the row of fluxed pins, the solder slurps off onto each pin in just
    the right amount. My people solder 240-pin FPGAs in just a minute or
    two this way.

    If anybody is doing any serious amount of soldering/desoldering,
    Metcal gear is well worth it.

    John
    ................
    I'm using this thing (its equivalent from Weller) to solder 100 pin
    FPGAs
    and it does work. But you need flux to prevent solder from spilling
    over
    multiple pins and shorting them together. I also found that this works
    better
    with higher temperature, I do it at around 400C.

    Soldered in about 600 over the years this way.

    Siol
    ...............
    Oh, one other tip: Metcal makes two hoofers, big and small, and my
    people prefer the big one. It holds more solder and works great on the
    fine-pitch parts.

    All this stuff is counter-intuitive.
    ...............

    Ever heard of rework paste? just clean up the pads and tin them paint
    on
    the rework paste then place the component on the pads, you can then
    either
    do every pin with your iron or use a hot air pen to fix the device
    afterwards clean up with some isoprop and a brush, Ive fitted loads od
    chips
    with this method and I might say with pin spacings of much less that
    1mm
    ,,,,,,, good luck
    ..........
     
  13. happyhobit

    happyhobit Guest

    The loupe is for inspecting the board after you solder it. (The old type
    looked like a black shot glass that was shoved in the eye socket, my loupe
    clips on to the sidepiece of my glasses.) With a focal length of 2", it's a
    little close to work with. (Kept burning my nose hairs.) A table mounted
    lamp / magnifying glass is the best for working. ( a fixed magnifying glass
    with extra good lighting works, or as someone suggested a jeweler's
    magnifying visor, with good lighting.)

    I use a 33 watt Ungar with a PL-114 (Micro Spade tip). I think this would
    constitute a "hoof" tip

    http://www.action-electronics.com/unpl.htm#On

    I also use a sharpened 3/16 dowel rod (sharpened in pencil grinder) to hold
    the chip in position while tacking it down.

    Rework paste (soldering paste) a fine ground solder mixed with flux, some
    like it, some don't, it's expensive, ages poorly. (keep refrigerated but not
    with food) I've used it, it is good, I don't need it.

    You've got lots of opinions from the newsgroup threads. Pick and chose until
    you find what works good for you, some will, some won't, we're all
    different.

    Jay
     
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