soldering small IC chips

[Snuffy]

I got a bunch of CD40106 cmos chips from mouser and they are tiny - about a fingernail sized with 14 pins. These are way to small for ordinary perfboard, difficult with my iron tip, etc. P.S. I'm using them to build synthsticks.
How to solder these?

[petemoore]

  I think you're talking about SMT's I dunno, I got some fingernail sized Jfets once 42 of them...I thought about making a mini plug in rig for them...couldn't use 'em. the legs are too short, I thnk they're made to be put in some kind of socket, 'standard' soldering would just short and heat-fry them.

[Snuffy]

I thnk they're made to be put in some kind of socket, 'standard' soldering would just short and heat-fry them.

yeah..... I guess I'll head down to rat shack to look for some sockets. tricky

[e178453]

It is easy to wind up with SMT parts when you wanted leaded components.  Check what type of package you are ordering.  SMT will say something like SOIC for small outline integrated circuit (Snuffy's chips), or SOT for small outline transistor ( Petemoore's jfets).  Don't think there are sockets for these.  Think what you wanted was 14 pin DIP package for chips and TO-92 for jfets.
scott

[vanessa]

They must be able to withstand some amount of heat. I see these all the time soldered to boards without sockets. If a robot can do it, I'm sure you could do it and better. I got a bunch of micro TL071's from Mouser by mistake a while ago (be careful when ordering your TL071's it did not say that they were the little micro version). I'm still trying to figure out how I can use them. What could be cool is you can solder them right to the traces on the underside of the board saving room up top for other stuff and shrinking the board of course.

[Snuffy]

It is easy to wind up with SMT parts when you wanted leaded components.  Check what type of package you are ordering.  SMT will say something like SOIC for small outline integrated circuit .....hink what you wanted was 14 pin DIP package for chips

Interesting... looking into it. Thanks 

[Cliff Schecht]

I don't know if it's because my dad taught me how to solder SMD parts when I was younger, but I've never had a problem replacing standard parts with their SMD equivalents. You just need a good set of tweezers and a somewhat steady hand. They are especially easy on perfboard, where you have almost the perfect amount of room between the copper on the holes to solder in some SMD resistors or caps. When you get into the electronics industry, especially in the integrated power type of stuff my dad has been doing for a while now. I guess you get used to working with smaller parts, but I agree that they are a bitch to work with.

[Meanderthal]

 Off topic, but how's your luck with the ribbon controller? I can't find any videotape that conducts at all(let alone acting like a resistor), and long mylar foil? None long enough to be useful. I'd LOVE to build a Tannerin (synthstick in a box sorta)!

[Snuffy]

Off topic, but how's your luck with the ribbon controller? I can't find any videotape that conducts at all(let alone acting like a resistor), and long mylar foil? None long enough to be useful. I'd LOVE to build a Tannerin (synthstick in a box sorta)!

Heh, I haven't even started on that stuff. I'll be shopping at thrift stores for cheap VHS tapes I guess, and I don't even know about the foil yet....

[Paul Perry (Frostwave)]

Off topic, but how's your luck with the ribbon controller? I can't find any videotape that conducts at all(let alone acting like a resistor), and long mylar foil? None long enough to be useful. I'd LOVE to build a Tannerin (synthstick in a box sorta)!

I've been looking for conductive rubber (more conductive than the stuff used for antistatic bench top repair stations). But no luck yet.

BUT!! the Tannerin wasn't made this way at all. It was (I believe) like an old radio dial arrangement, where a string goes alon g a linear path, then around a drum on the axle of a pot (things aren't clear, I suspect the 'pot' was actually a 10 - 400pf radio tuning air core cap). Whether the cap was part of a RC oscillator, or whether the whole thing was in fact cobbled from a radio, using the cap to sweep the local oscillator which hetrodyned (as in a theremin) with another fixed oscillator, I don't know. Both methods were used for wide range audio oscillators back in the day.
But in any case, think pot & string, perhaps!

edited to say, there is stuff on surface mount soldering in the lounge at the moment!

[Cliff Schecht]

For the resistive video tape, the older the tape the more likely it is to be resistive. Just bring a meter to a thrift store and probe all of the tapes until you find a resistive one. It's really easy to tell the resisitive stuff, it looks like a very flat, unglossy black and has more slippery texture than the non-resistive counterparts (as I remember). Anyways, that's not too hard to find, but I didn't much like the foil floating over the resistive tape idea, so I went about with a little brainstorming and made what I've found to be a cool alternative.

Using a broken guitar and a "special" nut (a tall piece of plastic), I made the pot used to determine the oscillators pitch by using the bridge and strings as one anchor point and the resistive tape stuck down with double sided sticky tape over a fretless fretboard. From the bridge to the tuners (and through the strings) is one anchor point (say point A), the resistive tape is anchor point b. Touching the strings to the tape gives you a pitch, moving your finger up the fretboard raises the pitch. Hard to describe, but here's a pic that illustrates what I did much better:


There's also a killswitch ala Buckethead (momentary SPST that shorts signal to ground), a volume (very necessary) and a front mounted output jack for pedalboard goodness. Here's a cool soundclip I recorded a while after I built this thing (back when I had a drumset in my room):
http://www.purevolume.com/cliffsjams (Guitarimin Jam).

Enjoy your synthstick, it's a great little toy.