Hoffman Amplifiers Tube Amplifier Forum

Other Stuff => Solid State => Topic started by: G._Hoffman on April 21, 2009, 05:05:08 am

Title: I knew there was a reason I hate surface mount components....
Post by: G._Hoffman on April 21, 2009, 05:05:08 am
I need to make a little super bright LED to go inside an old Fender Jewel light (kind of a long story - the short version is it's going to be a switch cap on a Jazzmaster).  So, I found a killer little LED, but it's an SMT part, and I HATE surface mount shit. 

So, I go to make a circuit board for it (tiny bugger - it's 8.5mm in diameter!).  So, I design it, print it up, and make the board.  I printed up five, of which three transfered cleanly enough, and two actually etched pretty well.  I've made a bunch of board with my Ferric Chloride, though, so when I was done I tossed it.  The only problem is, I'm so used to designing circuit boards for DIP parts, that I forgot the LED needs to go on the same side as the traces.  Everything is backwards.   >:( >:( >:( >:(  And now I have to go out to the middle of nowhere to get more FeCl3.   >:( >:( >:( >:( >:(


Gabriel
Title: Re: I knew there was a reason I hate surface mount components....
Post by: jhadhar65 on April 21, 2009, 02:46:08 pm
Are you hand-soldering that stuff?  Man, you'd have to be part jeweler, part raccoon to do work like that.  I've got a guitar on the bench now with some sort of preamp problem.  The board's chock full of those tiny micro midget surface whizzies.  I told the guy I'd replace the entire preamp or nothing.  I can't troubleshoot a surface board and I won't attempt to repair it.  I'm no luthier anyway and I really don't want guitar jobs, but I'm not culling too much these days.  Still, no surface work for me.  Good luck!!
Title: Re: I knew there was a reason I hate surface mount components....
Post by: G._Hoffman on April 21, 2009, 03:09:04 pm
Quote from: jhadhar65 on April 21, 2009, 02:46:08 pm
Are you hand-soldering that stuff?


Sadly, yes.  It sucks, yes, but it's the right part for the job.  I need a fairly large amount of light, in a very small flat space.  What can you do?



Gabriel
Title: Re: I knew there was a reason I hate surface mount components....
Post by: jhadhar65 on April 21, 2009, 04:30:05 pm
>What can you do?

I understand what you're up against.  It would look like the Hulk tried to make a jelly biscuit with his feet if I tried to hand solder one of those - continuity all around and every component would be fried before I could even get supply voltage hooked up!  I was googling to see if I could find a hobby-size wave machine for you and found this:

http://www.curiousinventor.com/guides/Surface_Mount_Soldering/101

You're probably well versed in all this, but maybe you'll find something in the videos that will make your task easier.
Title: Re: I knew there was a reason I hate surface mount components....
Post by: G._Hoffman on April 21, 2009, 05:08:16 pm
Well, in this case it's pretty easy, as five of the 6 solder pads all get connected to one another.  (It's a little chip with 5 LED's in one package, sharing a common anode). 

I've got a bit of surface mount experience, though, as the old Fishman Pocket Blender system required you to add a couple resistors and a cap which were all SMT parts.  It is a giant PITA, though.  Also, since it is just an LED, it's pretty robust.


Gabriel