livingnote

SMD?
« on: December 12, 2008, 06:17:29 AM »
I just recently got into SMD, and I have to say...

I LOVE IT!

It's so dead reliable, and comfortable to work with, takes up very little space, and from what I can tell the difference is basically a question of package, like a 5532 in a SOP is just a 5532, only with less plastic around it.

Also I am very impressed by the fact that the size takes a bite out of any EMI, less antenna in your box.

What might be cool is a little SSL-style balancer mounted to an XLR connector, that you can just stick in any box. I take very well to this Lego-style approach where you have a bunch of fun building blocks and can just mix-n-match things. Or an SMD CnB, you know, that is about as big as a large postage stamp ;)

What's you guys' experience?
Quote from: emrr
F-in' hook some Sh*t up and see if it catches on fire

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clintrubber

Re: SMD?
« Reply #1 on: December 12, 2008, 06:24:16 AM »
What's you guys' experience?

I guess for most people here SMD is just something to get used to (if not already), but no real problem.

BUT... (imnsho) SMD looks pretty boring compared to 'real PCBs' with thru hole stuff: resistors with coloured bands, tropical fish caps and who knows even metal can semiconductors !  8)

Bye,

  Peter

livingnote

Re: SMD?
« Reply #2 on: December 12, 2008, 06:49:29 AM »
Yup that is absolutely true. All this crazy stuff like old radio is just exciting to look at.

One definitive other disadvantage is that rework is very tricky to do, unless you have really
good tools. What I have managed to do is build the Elektor-pizza-reflow oven controller and use
it with a cheapo 50€ ebay pizza oven, works like a dream and is dead reliable.

It is an issue, though, that some of these caps'n stuff just need to be through-hole, and I
end up doing mixed media. But I like it, it is a very calm and soothing workflow, and really
funny when you stick this circuit board in an oven, bake it, plug it in and it sounds great ;)
Quote from: emrr
F-in' hook some Sh*t up and see if it catches on fire

My Stuff: Livingnote's META

tv

Re: SMD?
« Reply #3 on: December 12, 2008, 07:23:58 AM »
If you sprinkle when you tinkle, please be neat and wipe the seat.

livingnote

Re: SMD?
« Reply #4 on: December 12, 2008, 07:31:16 AM »
Ooooohh num nums, yeah that's exactly what I mean.
Quote from: emrr
F-in' hook some Sh*t up and see if it catches on fire

My Stuff: Livingnote's META

tv

Re: SMD?
« Reply #5 on: December 12, 2008, 07:40:40 AM »
http://www.audioxpress.com/reviews/media/AE300CH.pdf

something to think about: plug-in cards (also look at JLM audio)
If you sprinkle when you tinkle, please be neat and wipe the seat.

livingnote

Re: SMD?
« Reply #6 on: December 12, 2008, 09:00:50 AM »
The link for the pdf gives me server not found...

:EDIT: Works now for some reason.
« Last Edit: December 12, 2008, 01:41:25 PM by livingnote »
Quote from: emrr
F-in' hook some Sh*t up and see if it catches on fire

My Stuff: Livingnote's META

tv

Re: SMD?
« Reply #7 on: December 12, 2008, 11:46:23 AM »
??? works for me ???
If you sprinkle when you tinkle, please be neat and wipe the seat.

Rochey

Re: SMD?
« Reply #8 on: December 12, 2008, 12:11:18 PM »
I just got into soldering SMD's myself this week.
What a joy. 0805's are simple, IC's are relatively simple. opa134's are a peice of piss to solder. (Y'all americans that need translation - "peice of piss" means simple in queens english)

Just a few suggestions from what I've learned. (and I'm open to correction)

- Flux is your friend.
- A temperature controlled soldering iron is very useful to have (mine is a $20 velleman one from Fry's...although i will upgrade to the hakko 936 soon)
- a "hoof" shaped tip is best. These soldering irons with a tiny pin sized tip are no use for soldering IC's. load up the hoof with a blob of solder, and drag accross the pins. Most of the time, they won't short to each other.

Youtube has a ton of videos on soldering SMD's.

Expat Audio Home: http://www.expataudio.com

Ptownkid

Re: SMD?
« Reply #9 on: December 12, 2008, 12:27:42 PM »
i've actually heard that solder paste works really well for smd stuff.


JohnRoberts

Re: SMD?
« Reply #10 on: December 12, 2008, 12:30:41 PM »
+1

I recall when we first started using SMT years ago in mixers and the immediate benefit to mic preamp layouts due to reduced loop area for sensitive circuits. You could just about fit the mic pramp under the input XLR. Back in the early days it was difficult to get some of the low noise transistors in SMT packages, because they were relatively large die for small signal transistors, but it was all worked out.

I don't have as warm and fuzzy feeling for SMT film caps, but maybe that has improved too... I had one bad experience with a small CM where the reflow temps affected the film caps, I tried to use. Ended up changing to a more robust part.

This is not new, the old polystyrene caps were not factory friendly for through hole.

JR


Don't only half-ass tune your drums. Visit https://circularscience.com to hear what properly "cleared" drums sound like.

Samuel Groner

    Zürich, Switzerland
  • Posts: 2935
Re: SMD?
« Reply #11 on: December 12, 2008, 12:42:30 PM »
Quote
But maybe that has improved too...

No.

Samuel

Andy Peters

Re: SMD?
« Reply #12 on: December 12, 2008, 01:16:13 PM »
I just got into soldering SMD's myself this week.
What a joy. 0805's are simple, IC's are relatively simple. opa134's are a peice of piss to solder. (Y'all americans that need translation - "peice of piss" means simple in queens english)

Just a few suggestions from what I've learned. (and I'm open to correction)

- Flux is your friend.
- A temperature controlled soldering iron is very useful to have (mine is a $20 velleman one from Fry's...although i will upgrade to the hakko 936 soon)
- a "hoof" shaped tip is best. These soldering irons with a tiny pin sized tip are no use for soldering IC's. load up the hoof with a blob of solder, and drag accross the pins. Most of the time, they won't short to each other.

I demonstrated to a friend how I solder QFP microcontrollers to a PCB. I put a dab of solder on one pad, aligned the part to the footprint, then properly attached that one pad. Next, I flooded the pins with flux, and did a drag of solder along the four edges of the board using a 600-degree tip on the Metcal SP-200. He was aghast: "All of the pins are shorted together!" Then I got out the fine sized solderwick and cleaned up the pads. Voila! No shorts, no bridges, and done faster than a DIP-40. A little scrub with a brush and Detergent 8, then a rinse with distilled water, and it's all ready to go.

-a
"On the Internet, nobody can hear you mix a band"

bcarso

Re: SMD?
« Reply #13 on: December 12, 2008, 03:42:04 PM »
When I designed the screen controller for Epson's Ensemble HD home theater system, I put the first boards together myself.  Bunch of SMD and through hole including a TSSOP uC, but mostly things on a little larger pitch.  Smallest Rs and Cs 0805.

The whole thing worked, including some fairly sophisticated hybrid signal processing, but when I brought it in to demo, the client was most impressed by the mere fact an old guy could lay down those teeny parts!

jdbakker

Re: SMD?
« Reply #14 on: December 12, 2008, 04:39:06 PM »
i've actually heard that solder paste works really well for smd stuff.

Absolutely.

See below for my latest SMD project (Rochey, these are the boards I talked about at AES Amsterdam). Passives are mostly 0603 except for some larger caps which are 0805; the microcontroller pin pitch is 0.5mm. I have hand assembled these; took me about 5 hours for the pair.



For scale:



(click to zoom)

These are sensor-watches, intended for mobility research. They include a 3D accelerometer in QFN, a temp sensor, a RTC, microSD for storage, Bluetooth for comms, a 128x128 OLED display, low-power switching regulators, a USB charger for the LiIon battery and an ESD-ruggedized I2C expansion port. The whole stack (boards, OLED and battery) measures 42x41x12mm.

I used a stainless steel stencil to apply solder paste, then put all the parts down with tweezers. After that I reflowed the solder on a hot plate. The process went reasonably well, and I'm working on streamlining it as I need to build a dozen more. There are over 60 line items (ie unique part/value combos) on both boards; sorting through these takes a considerable fraction of the build time.

JDB.

Ptownkid

Re: SMD?
« Reply #15 on: December 12, 2008, 05:33:27 PM »
 :o

livingnote

Re: SMD?
« Reply #16 on: December 12, 2008, 07:57:44 PM »
Yah now that's cool stuff. It's funny because I was scared sh*tless of SMD to begin with,
thinking that the solder paste was going to short everything to everything. I got it on the
hotplate going "this is never going to work, oh lord oh god what have I gotten myself into"
and then it went above Liquidus and suddenly - shguuck - everything sucked into place.

Actually my very first try was in a frying pan. And lo-it worked. I couldn't believe it as I
measured my resistors, and they all were right fine. Plus, I did some...err...field tests and
tried to brutally rip off some of the resistors, and they just wouldn't budge. Chipped Fingernail
and bent tweezers were all that I got.

And funny because somewhere in the process I found that all you really need to start with
reflow soldering is a hotplate, a pair of tweezers and a syringe o paste. Maybe a cheap IR
thermometer. Cost you less than 100 bucks.

Btw JD, just got off the phone with the works. Your front panel was etched today  :D
Quote from: emrr
F-in' hook some Sh*t up and see if it catches on fire

My Stuff: Livingnote's META

Svart

Re: SMD?
« Reply #17 on: December 14, 2008, 11:38:25 AM »
I reflowed a BGA with a heat stripper and some aluminum foil. 

Beat that.

 ;D

SMD is the best.  I'll never go back.
Welcome to the GroupDIY leper colony! when something falls off, we just replace it with a tube!
occupation: General Electron Mayhem

Alesis X2 information repository:
http://www.theopiumdenproductions.

JohnRoberts

Re: SMD?
« Reply #18 on: December 14, 2008, 12:15:02 PM »
SMT reminds me a little of the early days of digital audio... The long list of benefits out weighed the short list of complaints. Digital got better so here's hoping SMT continues to improve.

What are people using for critical film capacitors in audio band EQ circuits and such? I haven't found a dielectric that really keeps up with polystyrene. NPO is fine for small compensation caps. 

At least with DSP filters you don't have non-ideal capacitors to deal with.

JR
Don't only half-ass tune your drums. Visit https://circularscience.com to hear what properly "cleared" drums sound like.

Rochey

Re: SMD?
« Reply #19 on: December 14, 2008, 04:08:49 PM »
(Rochey, these are the boards I talked about at AES Amsterdam).

You are a seriously sick puppy. mere mortals aren't supposed to be able to assemble and solder like that.


Just a quick note, I upgraded my soldering iron this weekend from a Velleman VTSS5U $20 temp controlled soldering iron I had, (which it was near impossible to get new hoof tips for) to a Hakko 936.
What a blessing. The Hakko with a small hoof tip was awsome on my smd MSP430 processors. Just a blob of solder on the tip, then drag accross the pins. One single bridge, that was simply taken care of by heating the pins. The solder separated to each of the pins.

Really is worth the $90 from Fry's. (i'm sure there's cheaper places, but i'm impulsive!). There are some chinese knockoffs as well, which are a lot cheaper. Again, they are mail order, and I'm impulsive. Still, I can probably buy more tips in china now :)

/R
Expat Audio Home: http://www.expataudio.com


 

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