Schmart Board, opinions?

[TLengr]

I am thinking of using a couple of Schmart Boards for prototyping. I have one 48 pin TQFP and one 32 pin QFN chip for the project. Are these truly easy to solder chips on? My hands are not so steady anymore. Anything better out there?

[Cerebus]

How easy or difficult they are to use is a bit subjective. I haven't used Schmart branded boards but I've used the unbranded equivalent and they are, to my mind, very easy to use. I've used them for prototyping with SOIC ICs and SOT-23 transistor packages and I've had no problems hand soldering parts to them (drag soldering the multi-pinned packages). Even easier is using a dab of solder paste and one of the cheap 858D type hot air guns - I never tire of watching surface tension neatly align the packages once all the solder paste is molten.

[MagicSmoker]

I have Schmartboards and really like them, but I rarely build prototypes on a breadboard anymore so don't have as much need for them. Still, they are indispensable, especially for QFP packages.

As for how easy they are to solder, that's a bit like the proverbial "how long is a piece of string?" If you can solder the package in question by hand then you'll be able to solder it onto the Schmartboard!?!

[linux-works]

I used a few of them for a cirrus 8ch volume control chip:



not sure the grooves helped me that much, but it was a great little breakout board.

that is now in my home preamp and has been running things for about 4 yrs, now.

[TLengr]

Thanks for the replies. I agree "easy" is a very subjective term. I guess from replies the process with soldering on them is not a PIA. I have successfully removed and replaced a few SMT chips using hot air gun for re-flow, but I am pretty awful at hand soldering new installations. I am practicing and improving, but positioning and holding in place is a bit shaky.

"Not sure the grooves helped me that much, but it was a great little breakout board.
that is now in my home preamp and has been running things for about 4 yrs, now."

I saw a you-tube about using them and it appears they have an indentation for the chip body to sit in as well as the soldering grooves. Is this correct?

[MagicSmoker]

Thanks for the replies. I agree "easy" is a very subjective term. I guess from replies the process with soldering on them is not a PIA. I have successfully removed and replaced a few SMT chips using hot air gun for re-flow, but I am pretty awful at hand soldering new installations. I am practicing and improving, but positioning and holding in place is a bit shaky.

A trick I use to hand-solder SMT packages with more than 2 terminals (besides the proper method; ie - solder paste, a stencil and a reflow oven) is to apply a little blob of solder to just one pad (ie - no solder on any other pads), then use a small vacuum pen (e.g. - Hakko 394) or tweezers to position the component and tack the one pin down by touching it and the pad with the iron. I then carefully tack solder another pin some distance away from the first, and proceed with soldering the rest of the pins as usual (don't forget to resolder the first 2 pins, as the joints will be of marginal quality otherwise).

It really helps to have some fine desoldering braid and a no-clean flux pen on hand as well. I should reiterate that this process is appropriate for rework/repair/prototyping, and not for production - it takes way too long to solder parts this way. Also note that hot-air is great for removing components you don't intend to reuse, but not so good for putting them back on.

[ebclr]

Hand will be a problem, need to be firm, same for vision

[Ian.M]

No caffeine (Tea, Coffee or energy drinks) for 24H  + a good night's sleep before fine pitch SMD work will go a long way towards steadying most people's hands enough to get the job done.  Of course, if you've got a clinical condition that results in a tremor, its going to be a lot tougher . . .

Worst case, one can nudge the IC into place and tape it down with low-tack masking tape or similar leaving opposite corners exposed, and tack solder two corner pins to hold it so you can remove the tape and drag-solder the rest of the pins.  On Schmartboard, that should work for anyone who's tremor is controllable long enough to initially get the chip to 'click' into its footprint, and again to drag-solder each side

[rstofer]

Go to WalMart and get a hot plate:
http://www.walmart.com/ip/Elite-Cuisine-ESB-301BF-Single-Cast-Electric-Burner-Hot-Plate-Black/41196547

Put some solder paste on the pads, place the component and cook by simply placing the board on the plate, turn the knob on High and watch the solder.  When it has flowed, remove the board from the plate using tweezers.  Don't let the part fall off.  And turn off the plate...

I have done some fairly sophisticated boards this way (small boards) but, really, a modified Black & Decker InfraWave Toaster Oven is the way to go.  Here is the controller I used. 

http://www.rocketscream.com/shop/reflow-oven-controller-shield-arduino-compatible

I added a solid state relay in series with the heating elements, filled the wall cavities with high temperature insulation and hooked in the controller.  I place the thermocouple tip in one of the via holes so that it measures board temperature.

For just one part, hand soldering will work well.  Tack the corners, run a ribbon of flux across all the pins, put a bit of solder on the tip and drag the tip down the pins.  Repeat until all pins are soldered.  If there are any solder bridges, remove them with SolderWick.  Usually, you can clear them up by dragging the soldering tip down the pins.

I'm convinced the solution to soldering SMDs lies in the flux.

[TLengr]

Wow, these responses are great. Lots of good ideas. BTW, Linux-works, you did a great job with your audio project. Nice work. Thanks for sharing.
My unsteadiness is mostly from getting older, but I still like this kind of stuff and I like to learn new things. When I started as a tech, metal vacuum tubes with grid caps, elctrodynamic speakers, etc were around.
My biggest obstacles to working with SMD so far have been poor vision (I wear a flip-up head band with magnifiers) and positioning and keeping the chip in place long enough to anchor it down.  I thought maybe SchmartBoard would be a big help.  Sounds like some really like them. Can someone answer what is the shelf life of solder paste? Does it contain its own flux and does it need refrigeration? I am going to look further into the hot plate method. It sounds a bit intriguing to me, so I'm curious about it. Thanks to all for your assist on this, I appreciate it.

[rstofer]

Wow, these responses are great. Lots of good ideas. BTW, Linux-works, you did a great job with your audio project. Nice work. Thanks for sharing.
My unsteadiness is mostly from getting older, but I still like this kind of stuff and I like to learn new things. When I started as a tech, metal vacuum tubes with grid caps, elctrodynamic speakers, etc were around.
My biggest obstacles to working with SMD so far have been poor vision (I wear a flip-up head band with magnifiers) and positioning and keeping the chip in place long enough to anchor it down.  I thought maybe SchmartBoard would be a big help.  Sounds like some really like them. Can someone answer what is the shelf life of solder paste? Does it contain its own flux and does it need refrigeration? I am going to look further into the hot plate method. It sounds a bit intriguing to me, so I'm curious about it. Thanks to all for your assist on this, I appreciate it.

There will be an expiration date on the tube of solder paste.  Since a syringe full lasts YEARS, I don't worry about it much.  When it won't hardly come out the needle, I buy another one.  Yes, the solder has its own flux.

http://www.howardelectronics.com/smd-rework/chip-quik-low-temp-smd-rework/smd291/chip-quik-smd291-chip-quik-flux/
http://www.howardelectronics.com/soldering/soldering-accessories/solder-paste-and-flux/qualitek/p615d-013-8840i-qi-qualitek-sn63-37-solder-paste/

Howard Electronics doesn't appear to sell the brands I used to buy from them and I haven't tried these specific brands but it gives you an idea.

The syringes come with plastic needles.  I prefer the blunt metal needles like:

http://www.howardelectronics.com/industrial-needles/stainless-steel-blunt-needles/jensen-global-0.5-inch-needles/jg19-0.5-jensen-global-industrial-stainless-steel-needle/

I think that particular needle will work but, since I can't get at my solder paste (it still boxed from a move), I'm not sure.  I think the Yellow version may also work.  Try the plastic needle before jumping into the metal needles.

Maybe somebody else can help with needle selection.

[Vincent]

Schmart Boards haven't really caught my attention. Except this one:



Apparently you can fit both standard DIP and shrink DIP packages on it. This may come in handy if I have SDIP ICs to work with.