So...i need help with my Nichia LED...im stuck on very stupid thing...so my first question is about LED standoff, why are leds produced with it(i know what standoff means but why, what for?,there are no stupid questions only stupid answers), my second question is about soldering and its related to first question...how to position led on PCB where to solder it... leave the standoff on top side of PCB and solder after the standoff?...or to put the standoff trough hole and solder it on standoff? ...thank you for your time guys

 

This is probably a stupid answer, because it is actually two questions. Do you want the led base to be flush with the PCB surface? Or do you want it to "stand off " from it? ... (The only dumb question is the one not asked.)

 

#1) What if the PCB to which the LED was attached was 1 cm below the case. Then, having the LED stand high is an advantage.
#2) There are different ways to solder a through-hole (TH) component. What are the "standoffs" made of? If not a conductor, e.g, ceramic or teflon tube, then soldering to them is impossible. Are the holes in the PCB plated through? If so, assemble the LED and standoffs ("top side") and solder from the other side ("bottom"). If not plated through, then pull the LED out just enough to clear your soldering iron tip, solder from the top side. I then re-heat the leads from the bottom and re-seat theLED, so the result is the same as with plated-through holes.

 

#1) What if the PCB to which the LED was attached was 1 cm below the case. Then, having the LED stand high is an advantage.
#2) There are different ways to solder a through-hole (TH) component. What are the "standoffs" made of? If not a conductor, e.g, ceramic or teflon tube, then soldering to them is impossible. Are the holes in the PCB plated through? If so, assemble the LED and standoffs ("top side") and solder from the other side ("bottom"). If not plated through, then pull the LED out just enough to clear your soldering iron tip, solder from the top side. I then re-heat the leads from the bottom and re-seat theLED, so the result is the same as with plated-through holes.

The PCBs are single sided so LEDs go on top...soldering takes part on bottom side...they dont have any case the are just mounted on PCB(pcb is the "case")...so how to solder....lets make it simple A or B? My biggest problem is for solution A hole is 0.6mm big for solution B its 1.2 or 1.3mm...its very big i would like to use solution A, what do you think?

 

How high do you want the LED to sit from the PCB? If it is as in A, then solder it as in A. If it is as in B, then solder it as in B. In neither case will you violate the no-solder zone.

A little more information in your question would have led to a much more straight forward and simple answer.

John

 

How high do you want the LED to sit from the PCB? If it is as in A, then solder it as in A. If it is as in B, then solder it as in B. In neither case will you violate the no-solder zone.

A little more information in your question would have led to a much more straight forward and simple answer.

John

Thank you John very much!

Dominik

 

My practical experience is that LEDs are sensitive to temperature. Maybe overheating during soldering has some sort of annealing effect on the diode inside, but I've noticed a mild to serious decrease in brightness (sometimes so much that the LED appears to no longer work) when too much heat is applied during soldering. Maybe modern LEDs are more rugged, but I'm generally a coward about it, and use as long a standoff height as I can, and put a heat sink on the lead (an alligator clip is better than nothing) while soldering very quickly.

 

yes with unregulated iron you can trash the LED.

But its possible to solder to PCB "flush", without clearance.

You need station + broad tip. So it doesnt take long. Dont move them the plastic can become soft from the heat + break out one pin.

 

Yea i have already ordered thease spacers for my Leds...they are 6.4mm high from pcb + pcb 1.6mm thats around 8 mm from soldering point to base start of LED...

 

I keep a supply of small bore Teflon tubing handy. It is great for stand offs, insulation in tight spaces, and so forth. My PCB drills for most TH components are #66 (0.033"), so any tubing about that size or larger will work. 0.038" I.D. teflon is a common size and is what I use.

John