Building a Home Made LED

[rives]

rives could you point to a post or pic or something for that inductive hot plate method? I've searched but cannot fiond anything I searched for the "shafto method" you have mentioned multiple times but cannot find it...

tenthirty, the XM-L pump out more intensity that the solarstorm 800? ouch! cannot wait to fire up my HML today!

Sorry, I didn't take any pictures. The "Shafto method" was detailed to me in a PM when I asked him about his technique for using a hot plate. The use of an inductive hot plate was my spin on it - I didn't have a hot plate and when I started researching them, I came across the induction models. They are much more responsive, and not that much more money. Then I saw the the "interface disc" for standard cookware, and it looked perfect for use as a platten. Mine is a 3/8" thick piece of stainless steel with an insulated handle.

You use paste solder and put a drop on each of the connection points. Place the LED on the star, using the markings on each to get them consistently centered - it's pretty obvious when you get the parts in hand and look at them closely. Make sure that the chip is oriented correctly for the power polarity. I did 6 at a time, placing them in a circle around the plate. Turn on the heat and watch carefully, it happens pretty quickly - the solder will "flash" from a dull grey to a shiny silver when it melts. Remove it from the heat (I set the plate on a large chunk of iron to sink the heat away quickly for the next round), and remove the completed stars with a pair of needle nose pliers and set them gently aside to cool and freeze the solder.

When the plate is cool enough to comfortably touch, do it again. It would be a good idea to wear a conductive wrist strap while doing this so that you don't zorch the chips with static electricity.

 

[hempfield]

Sorry, I didn't take any pictures. The "Shafto method" was detailed to me in a PM when I asked him about his technique for using a hot plate. The use of an inductive hot plate was my spin on it - I didn't have a hot plate and when I started researching them, I came across the induction models. They are much more responsive, and not that much more money. Then I saw the the "interface disc" for standard cookware, and it looked perfect for use as a platten. Mine is a 3/8" thick piece of stainless steel with an insulated handle.

You use paste solder and put a drop on each of the connection points. Place the LED on the star, using the markings on each to get them consistently centered - it's pretty obvious when you get the parts in hand and look at them closely. Make sure that the chip is oriented correctly for the power polarity. I did 6 at a time, placing them in a circle around the plate. Turn on the heat and watch carefully, it happens pretty quickly - the solder will "flash" from a dull grey to a shiny silver when it melts. Remove it from the heat (I set the plate on a large chunk of iron to sink the heat away quickly for the next round), and remove the completed stars with a pair of needle nose pliers and set them gently aside to cool and freeze the solder.

When the plate is cool enough to comfortably touch, do it again. It would be a good idea to wear a conductive wrist strap while doing this so that you don't zorch the chips with static electricity.

Do you solder the thermal pad also ? I find this part to be the most challenging , especially because you could not see under the LED. Does the LEDs tend to float and to move away from their position when the solder is melting ?

Just a tip : you can use a small PC fan to blow some air over the LEDs after the solder is melted, increasing the cooling speed.

 

[medmaker420]

Just a tip : you can use a small PC fan to blow some air over the LEDs after the solder is melted, increasing the cooling speed.

does that do anything negative to the bond of the solder itself cooling faster?

 

[hempfield]

I don't think so. If the solder has melted completely and the parts (LEDs) are not moving, there is no worry for imperfect (cold) contacts.

I always gently blow over the soldering points to help them cool faster

 

[rives]

Do you solder the thermal pad also ? I find this part to be the most challenging , especially because you could not see under the LED. Does the LEDs tend to float and to move away from their position when the solder is melting ?

Just a tip : you can use a small PC fan to blow some air over the LEDs after the solder is melted, increasing the cooling speed.

Yes, you do all of the points at the same time including the thermal pad.

If you take a look at the led specifications, you aren't supposed to cool them too quickly. They specify ramp up, hold, and ramp down times for the "ideal" installation.

 

[medmaker420]

I don't think so. If the solder has melted completed and the parts (LEDs) are not moving, there is no worry for imperfect (cold) contacts.

I always gently blow over the soldering points to help them cool faster

reason I ask is, I have soldered many things outside of led panels and the cooling was the first downfall and wondered how it went with led soldering.

 

[tenthirty]

Damn Rives,

I just reviewed your DIY Hybrid luminaire build. Really expert skills, so I can see how you were willing to solder the stars.
Did you burn any up? or yourself? LOL. (learning curve)

 

[rives]

reason I ask is, I have soldered many things outside of led panels and the cooling was the first downfall and wondered how it went with led soldering.

I soldered about 150 of these with the above method, not force-cooling anything, and had 100% success. There wasn't a single failure from excessive heat, or anything else. LEDs are far more heat-resistant than I ever would have expected.

 

[rives]

Damn Rives,

I just reviewed your DIY Hybrid luminaire build. Really expert skills, so I can see how you were willing to solder the stars.
Did you burn any up? or yourself? LOL. (learning curve)

The above answered the question on the components, but yes my finger tips and forearms didn't escape unscathed!

 

[hempfield]

If you take a look at the led specifications, you aren't supposed to cool them too quickly. They specify ramp up, hold, and ramp down times for the "ideal" installation.

This is the ideal way to do it, when you operate a temperature controlled re-flux soldering station. But if the hot plate it's to hot you could speed up a bit the cooling process.

Anyway, if you take a close look at the soldering points and they are shiny, it means the soldering was good. If it's not shiny, the solder may be cracked because some crystals formed inside.

LEDs are far more heat-resistant than I ever would have expected.

Indeed, I had one almost melted by the soldering iron, and the silicon lens has fall out exposing the chip, but it's parameters was not affected (well, beside the angle of view).

 

[rives]

This is the ideal way to do it, when you operate a temperature controlled re-flux soldering station. But if the hot plate it's to hot you could speed up a bit the cooling process.

Anyway, if you take a close look at the soldering points and they are shiny, it means the soldering was good. If it's not shiny, the solder may be cracked because some crystals formed inside.

Maybe I wasn't clear above - after I removed the platten from the hot plate, I picked the stars off and set them aside to cool naturally. I was concerned that the plate could hold too much heat for too long.

 

[hempfield]

Maybe I wasn't clear above - after I removed the platten from the hot plate, I picked the stars off and set them aside to cool naturally. I was concerned that the plate could hold too much heat for too long.

Do you think that this method can be used to solder LEDs on a much bigger PCB , like 18"x36" ? I assume that this should be done on small areas of the PCB if a hot plate of this size is not available.

Or we can use the hot plate from a fast food and fry some eggs and burgers in the same time (just kiddin')

 

[vukman]

I soldered about 150 of these with the above method, not force-cooling anything, and had 100% success. There wasn't a single failure from excessive heat, or anything else. LEDs are far more heat-resistant than I ever would have expected.

I do have one question though....what is an old man with failing vision like me suppose to do!!!!! ROFL!~~~~

Hehheh.. I get everything you're saying but damn those little contact points!! I have enough trouble reading my monitor at times!!
Never mind trying to dab solder onto points and then position a chip onto the cold solder and move it onto an induction pad!

You must have nerves of steel brother. At least I'm not as bad as some people I know who can't even raise a drink or anything for that matter, up to their mouth without shaking like a damn vibrator!

My father used to be a tool & die maker and he would talk about tolerances in the tenths of a thou. That's all fine when you've got a machine and you're turning a dial. Now-a-days even the vernier calipers are digital. Who remembers the old 'manual' ones where you had to line up the lines to get the readings or the micrometers on the shaft to measure tenths??

Oh yeah,, that's when I could see.......LOL

 

[vukman]

Do you think that this method can be used to solder LEDs on a much bigger PCB , like 18"x36" ? I assume that this should be done on small areas of the PCB if a hot plate of this size is not available.

Or we can use the hot plate from a fast food and fry some eggs and burgers in the same time (just kiddin')

I was watching something someone linked to where there was this guy talking about 'new' technology and one of the items was an induction plate...He showed how quickly you could fry and egg and yet he took the pan off and placed his hand right onto the induction plate without burning himself and then for the added effect, he placed a newspaper on the induction plate and then continued to fry the egg through the paper!!! LOL

It's amazing when you think of how far we've come with technology at times..

 

[rives]

Do you think that this method can be used to solder LEDs on a much bigger PCB , like 18"x36" ? I assume that this should be done on small areas of the PCB if a hot plate of this size is not available.

Or we can use the hot plate from a fast food and fry some eggs and burgers in the same time (just kiddin')

I would kind of doubt it, but it could probably be calculated out. I think that it would come down to regarding the 18x36 as a heat sink, figure the input wattage and the heat dissipated, and then arrive at the temperature that the piece achieved. If it is high enough to make the solder flow, bingo. Interesting idea, but it seems like it would take a pretty extraordinary hot plate!

 

[PetFlora]

This should simplify a DIY led project http://makersled.com/?p=396

 

[hempfield]

I was watching something someone linked to where there was this guy talking about 'new' technology and one of the items was an induction plate...He showed how quickly you could fry and egg and yet he took the pan off and placed his hand right onto the induction plate without burning himself and then for the added effect, he placed a newspaper on the induction plate and then continued to fry the egg through the paper!!! LOL

It's amazing when you think of how far we've come with technology at times..

This is because the current in inducted on the bottom of the pan. If you use a glass pan on the induction plate you can wait forever to fry that eggs. But I don't think that is a good idea to put your hand over the induction plate if you have any kind of metal ring on your fingers

 

[hempfield]

This should simplify a DIY led project http://makersled.com/?p=396

Damn, is so easy to build a LED panel this days. I wonder what surprises the future reserves for us ...

 

[xmobotx]

would like to see further discussion re; color temp choices

i.e. going to run 5 LEDs; 3 ww/2nw? 3nw/2ww? 2nw/2ww/1cw? all warm? all neutral?

seeing;

WW+ NW+ CW in a 2:2:1 ratio

this seems logica/ and very tempting but cant help but wonder if better served by 3 ww/2nw or;

If this is correct, this means that it was a mistake for me to put the 66nm leds on my first light.

the 660 convo is something i havent looked in to

iff 660 presents some drawbacks, could it be a poor plan to emphasize the ww?

maybe it would be a better idea to run 4 nw and 1 ww if too much 660 presents a problem?

 

[tenthirty]

I do have one question though....what is an old man with failing vision like me suppose to do!!!!! ROFL!~~~~

Hehheh.. I get everything you're saying but damn those little contact points!! I have enough trouble reading my monitor at times!!
Never mind trying to dab solder onto points and then position a chip onto the cold solder and move it onto an induction pad!

You must have nerves of steel brother. At least I'm not as bad as some people I know who can't even raise a drink or anything for that matter, up to their mouth without shaking like a damn vibrator!

My father used to be a tool & die maker and he would talk about tolerances in the tenths of a thou. That's all fine when you've got a machine and you're turning a dial. Now-a-days even the vernier calipers are digital. Who remembers the old 'manual' ones where you had to line up the lines to get the readings or the micrometers on the shaft to measure tenths??

Oh yeah,, that's when I could see.......LOL

Youth is wasted on the young.

I use to be able to read the writing on the smallest of transistor and chip and had rock steady hands......no more, really pisses me off sometimes.

What I use is one of those lights with a magnifying glass built in and if it's really tiny a USB microscope. I try to brace my hand and arm on something, and that seems to do the trick.