Is there an EASY DIY method to mount LED to star board?

[seaheard]

Does anyone know of a proven method to mount an individual LED to a star board? Is a reflow oven the only reasonable option?

[theatrus]

A skillet with some solder paste works really well. So does using hot air, or a toaster oven.

[der_wille_zur_macht]

Replied in the big thread. Plenty of ways. The trick is: consistency, not damaging the LED, and finding a method that you don't mind doing however many times you'd need to build an LED array (many times!) Personally, doing one-off stuff is fine, but I wouldn't bother trying to mount a few dozen emitters on stars just to save a few cents each.

[kcress]

NOT RECOMMENDED. You are going to spend way more than just buying them pre-mass assembled.

[seaheard]

I was given a about 100 CREE leds (emitters only - not mounted) I figured if there was a method it could save me a significant amount. My plan is to have (3) 36 LED fitures over my 180. Could equate to $700 in savings! Open to ideas and I'm not afraid to put the time in if necessary.

[mcgyvr]

easy http://www.youtube.com/watch?v=6FJmt2Fgzr4

[imagex]

easy http://www.youtube.com/watch?v=6FJmt2Fgzr4



that link is to take off... this is to add on..

http://www.youtube.com/watch?v=rHyRLQexJpA&feature=related

[seaheard]

Thanks everyone. I think I'll give the skillet reflow method a shot.

http://jmillerid.com/wordpress/2010/03/led-lighting-part-2/

[der_wille_zur_macht]

that link is to take off... this is to add on..

http://www.youtube.com/watch?v=rHyRLQexJpA&feature=related

He titled that video "wave soldering" which is pretty incorrect. Wave soldering is when you pass an entire PCB under a waterfall (or "wave") of molten solder. Also, his method of heating up the "bare" star MCPCB and then placing the LED on it is a little unconventional - most reflow processes would have the parts placed before the heat was applied.

Thirdly, he's soldering a used LED onto a used PCB. There's solder on both parts when he starts. If you're starting with new, bare LEDs and never-used star MCPCBs, you'll need to add solder and flux. Reflow soldering would typically use a separate flux and (paste) solder application.

Oh, and that's not the silkscreen he's charring off, it's the top insulating layer on the MCPCB!

And near the end, when he's testing the LED, he mentions soldering DIRECTLY to the LED's exposed pads instead of the MCPCB's if you mess up the reflow process. Regardless of if that works or not, it's important to note that the solder joint underneath the LED is very important from a thermal perspective, not just an electrical perspective. So if you mess it up, you really should just fix it, or not use that LED.

IMHO if you're going to do this, use a toaster oven or a hot plate (electric skillet). Don't use a coil "burner" on an electric stove. You're going to get terribly uneven heating that way.

Please note that I'm being critical in an attempt to help people learn, not to tear this guy down. He definitely got what he wanted in the end - a flashlight that worked!

[der_wille_zur_macht]

Thanks everyone. I think I'll give the skillet reflow method a shot.

http://jmillerid.com/wordpress/2010/03/led-lighting-part-2/

IMHO that's a much better reference on the process.

[seaheard]

He titled that video "wave soldering" which is pretty incorrect. Wave soldering is when you pass an entire PCB under a waterfall (or "wave") of molten solder. Also, his method of heating up the "bare" star MCPCB and then placing the LED on it is a little unconventional - most reflow processes would have the parts placed before the heat was applied.

Thirdly, he's soldering a used LED onto a used PCB. There's solder on both parts when he starts. If you're starting with new, bare LEDs and never-used star MCPCBs, you'll need to add solder and flux. Reflow soldering would typically use a separate flux and (paste) solder application.

Oh, and that's not the silkscreen he's charring off, it's the top insulating layer on the MCPCB!

And near the end, when he's testing the LED, he mentions soldering DIRECTLY to the LED's exposed pads instead of the MCPCB's if you mess up the reflow process. Regardless of if that works or not, it's important to note that the solder joint underneath the LED is very important from a thermal perspective, not just an electrical perspective. So if you mess it up, you really should just fix it, or not use that LED.

IMHO if you're going to do this, use a toaster oven or a hot plate (electric skillet). Don't use a coil "burner" on an electric stove. You're going to get terribly uneven heating that way.

Please note that I'm being critical in an attempt to help people learn, not to tear this guy down. He definitely got what he wanted in the end - a flashlight that worked!

Thanks for the info., very informative and I think I'll go with the skillet method. I plan on picking up an infared temp. gun (Harbor Freight $25). This way I can more accurately reach and do my best not to exceed 210-225 C (peak reflow point) and not completely cook the star mount.

Thanks again.

[der_wille_zur_macht]

If I were you, I'd get a handful of no-name China-special HP LEDs on eBay. You can pick them up for maybe a buck each. This way, even though your "good" LEDs were free, you're not risking them in your experiments.