Wanted: IC's for solder practice

[3v0]

I need to find unwanted IC's that my class can use to practice soldering. I need at least 50. I would prefer narrow dip chips, not the larger spacing used on 24 pin and larger DIPS.

I will pay shipping, maybe a bit for the chips.

 

[ericgibbs]

I need to find unwanted IC's that my class can use to practice soldering. I need at least 50. I would prefer narrow dip chips, not the larger spacing used on 24 pin and larger DIPS.

I will pay shipping, maybe a bit for the chips.

hi 3v0,
How many would you like, I have quiet a number of the older 74 series 0.3inch pitch.

They are yours free gratis, just the postage will cover it.

 

[3v0]

hi 3v0,
How many would you like, I have quiet a number of the older 74 series 0.3inch pitch.

They are yours free gratis, just the postage will cover it.

If you were not in the UK I would jump on the offer. First I need to check out what it would cost to ship them. I would like about 200 of them. That may last me 2 or more years. Depends on how fast the kiddies catch one. Do you have paypal ?

EDIT: I did not have them do enough practice last year and I spent more time then I wanted finding problems on their projects. I have 3 times the students this year.

Any idea how may chip/pins per pound are we looking at ?

 

[ericgibbs]

hi 3v0,

Just did a quick ic head count, there are qty 210, 74TTL 0.3inch. 14 and 16 pin, plastic case.

Weighed on kitchen scales, 220gm.

They are loose, never been used, a quick pop in an ultrasonic cleaner bath, they will be as good as new.

If you decide to have them, just PM with despatch info.

 

[picbits]

See if you can find a big company (ST / Microchip / National etc) who are in the same country and drop them an email. Make it clear that they don't have to actually work and you might be pleasantly suprised by the response.

 

[Speakerguy]

I have some parts that failed product test from my last job. A whole bunch of 28TSSOP chips. I'm going to use a lot for my own soldering practice but I'll send you the leftovers after I'm done.

 

[Speakerguy]

Also, just go to TI.com and order free samples of their cheapest chips. MAX232 are cheap and they will send you 10. There are other inexpensive chips.

 

[gerty]

What I do here is have my students remove components from a trashed board to learn desoldering techniques. They then are given a piece (12") of 24 ga solid from some cat5 cable and must solder the wire where the components were. They make a connection, cut it off, move to next hole and do it again. Another thing we do is to make a splice of #12 awg then try to solder it, this shows that you need the proper wattage iron for the size of the wire.

 

[jimmythefool]

Thats a very good idea Gerty...
Soldering a new IC is one thing, but re-working a board is a good skill to learn.

 

[Krumlink]

Why not get sockets and save the chips?

 

[Nigel Goodwin]

Why not get sockets and save the chips?

Try reading the thread title - it's for soldering PRACTICE.

 

[3v0]

Thats a very good idea Gerty...
Soldering a new IC is one thing, but re-working a board is a good skill to learn.

Thanks everyone.

Erlck has donated sufficient DIPs.

These kids have never touched a soldering iron. I will be happy when they can do a NICE job of soldering DIPs. I rushed it last year and spent too much time tracking down and fixing problems because of it. Basics come first.

I have a good selection of old MBs with surface mount chips if/when we get to SMD stuff.

I would rather not use samples for this.

 

[futz]

Try reading the thread title - it's for soldering PRACTICE.

Sockets can be soldered in, same as chips. Maybe cheaper than chips, but maybe not.

 

[Speakerguy]

Resistors are also very very very cheap.... you can buy 5,000 carbon film resistors from digikey for $30 + shipping.

 

[Nigel Goodwin]

Sockets can be soldered in, same as chips. Maybe cheaper than chips, but maybe not.

Not cheaper than getting old chips for free!

 

[mvs sarma]

The whole issue lies in getting chips without pin corrosion. Generally these Chips, unless stocked properly, develop a lot of corrosion and would pose a problem for soldering.

 

[ericgibbs]

The whole issue lies in getting chips without pin corrosion. Generally these Chips, unless stocked properly, develop a lot of corrosion and would pose a problem for soldering.

hi Sarma,
The ic's I am planning to send to 3v0 are not corroded, the legs/pins are lightly tarnished, a quick dip in an ultrasonic cleaner bath will remove the tarnish, making them easy to solder.

When ever components are stored in 'air' the oxygen give a tarnish to the surface.

 

[mvs sarma]

hi Sarma,
The ic's I am planning to send to 3v0 are not corroded, the legs/pins are lightly tarnished, a quick dip in an ultrasonic cleaner bath will remove the tarnish, making them easy to solder.

When ever components are stored in 'air' the oxygen give a tarnish to the surface.

Oh, Eric, it was not aimed at you at all please, but a general note. I used to suffer the soldering issues with "tarnished" pins. Now that you tolsd a way out, I would try.

 

[ericgibbs]

Oh, Eric, it was not aimed at you at all please, but a general note. I used to suffer the soldering issues with "tarnished" pins. Now that you tolsd a way out, I would try.

hi Sarma,
No problemo.!

 

[mneary]

I have a lot of tarnished chips from the 70's; they appear to be silver plated (unique color of the tarnish; could be tin I suppose). What do you use as the reagent in the ultrasonic bath to clean them?

Also I have a lot of MOSFETs that have been in anti static foam forever (which has become very sticky). Any suggestions for a static safe bath? And where to shop for the ultrasonic unit?

(I hope this doesn't end up hijacking the thread.)