DIY- High Powered Surface Mount Diodes.

NaturalFarmer

NaturalFarmer

Well-Known Member
Here is an introduction to reflowing SMDs to MCPCBs along with a shopping list. Any solder paste slop is best taken care of with solder wick and alcohol once your finished but its best to use only as much paste as will be needed. Ensure you have good ventilation, flux is nasty to breathe in.
A few tips to get started. Cold solder paste is hard to work with. Warm up to room temp before using.
I start by adding a small dab of solder paste onto the contact and use it to hold the emitters in place and in the right direction (+/-).

Heat the MCPCB up to 400 degrees using the electric griddle and the emitters will align themselves once the solder tins. Pushing the dome down and squeezing out any excess solder once it tins, is a little tricky but its not that difficult after a few tries of getting the amount of paste right. A good set of tweezers makes this easier I think. You just want to ensure the emitter pulls back onto the contact in both directions to ensure you have a good solder coverage on the entire pad.

Determining cathode or anode is a little hard at first but make sure you have the correct datasheet and grab them out of their packaging the same way every time you grab it. The Cathode usually has a notch on one side but sometimes it can be on the anode side with some, which is why you need to look at the datasheet for whatever emitters you are using.









Hakko FX-888D Soldering Station $100
https://www.walmart.com/ip/Hakko-FX888D-29BY-P-ESD-Safe-Digital-Soldering-Station-w-FX8801-Soldering-Iron-and-T18D16-Tip/639197406?wmlspartner=wlpa&selectedSellerId=4698&adid=22222222227079956114&wmlspartner=wmtlabs&wl0=&wl1=g&wl2=c&wl3=192851272969&wl4=pla-302716059267&wl5=9002675&wl6=&wl7=&wl8=&wl9=pla&wl10=113719749&wl11=online&wl12=639197406&wl13=&veh=sem

$20 Presto electric griddle
https://www.amazon.com/Presto-07030-Touch-Electric-Griddle/dp/B001078UCC

Adjustable 30v power supply $60
https://www.amazon.com/dp/B00ZBCLJSY/ref=sspa_dk_detail_5…

Adura/Sinkpad 1971 PCB (Printed Circuit Board) $2-3 each
http://aduraled.com/product/pcb/1971-66mm-round-oslon-ssl-sandra-optics

Osram SSL80 3500k $1-$2 each
https://www.mouser.com/ProductDetail/OSRAM-Opto-Semiconductors/GW-CS8PM1CM-KULQ-XX56-1?qs=sGAEpiMZZMu4Prknbu83y9cFe02ZjSci%2bfEXyUsg9qTGWAcIr9zcCQ==

No clean solder paste 37/63 $20
https://www.mouser.com/Chip-Quik/Tools-Supplies/Soldering/Solder/_/N-b11qq?P=1z0xha9Z1yywsskZ1yzt5joZ1z0xgxd

Solid core 18 AWG hook-up wire (Red and Black)
https://www.digikey.com/en/product-highlight/g/general-cablecarol-brand/hook-up-wire

Meanwell driver

1 Cased Potentiometer $6
https://www.rapidled.com/cased-potentiometer-with-knob/

Grounded power cord (I would recommend longer than you need by a few feet.)
https://www.rapidled.com/3-prong-us-power-cord-6/

Heat Shrink tubing kit
https://www.digikey.com/product-detail/en/qualtek/Q2-Z-QK1-01-6IN-180/Q2Z1-KIT-ND/754916

140mm round Pin Fin Heat sink
https://www.rapidled.com/140mm-pin-heatsink/

2 part thermal epoxy
https://www.digikey.com/products/en?mpart=8329TCM-6ML&v=473

I left out a rivet gun, tweezers, rivets, drill and aluminum channel bar but they can all be found at the box store.
 
Last edited:
NaturalFarmer

NaturalFarmer

Well-Known Member
I redid the Rapidled links. Was it only the RapidLED links that brought you to facebook? Not really sure why it was doing that but hopefully that is better. They all seem to work on my end now.
The walmart and amazon links will probably expire in a few weeks.
 
Last edited:
justsmokedope

justsmokedope

Well-Known Member
im also using sink pads but im having an issue with the leds not lighting up after reflow.
leds all are fine i think its the stencil ive been using isnt getting enough paste under the leds . im thinking of taking all the leds off and putting more paste on an re doing them .

do i need to do this or can i just put blobs of solder paste net to each led would this get sucked under each led ??? and fix my issue ??
 
NaturalFarmer

NaturalFarmer

Well-Known Member
Just a dab on the side and then reheat should make things better. Sometimes they flip when heated, are you sure they are still lined up right? Good luck
 
justsmokedope

justsmokedope

Well-Known Member
NaturalFarmer said:
Just a dab on the side and then reheat should make things better. Sometimes they flip when heated, are you sure they are still lined up right? Good luck
Click to expand...
thanks. . yes they seem to be the dot is facing the + (cree leds) the only difference i can think off is the ones i just hand blobed the solder on the pcb had load s more solder on and work . The ones with the stencil dont work must be the amount of solder im thinking
 
justsmokedope

justsmokedope

Well-Known Member
NaturalFarmer said:
Just a dab on the side and then reheat should make things better. Sometimes they flip when heated, are you sure they are still lined up right? Good luck
Click to expand...
fing cree they have changed the markings on the new XPE2 RED the dot on the front is opposite all the other leds have the dot the same side as the arrow on the back

just flipped those leds on the pcb and it all works great
 
Last edited:
V

VegasWinner

Well-Known Member
man this is so cool. IF I had smaller hands I would consider. I build a lot of stuff. Right now a 3d printer. My ole lady laughs every time she hears screws, nuts, ect hitting the floor, slipping between my fat fingers. I am skinny guy, but my Dad was 7' tall with big hands over 300 pounds easy. Me not so much heavy but I have the hands not the wight. LOL.

I had to do PCB made by others because my fingers are too fat. lol I really li9ke reflow work too. nice work, looks excellent. love the DIY is everywhere now.

Do you guys buy diodes in reels or how ?
 
NaturalFarmer

NaturalFarmer

Well-Known Member
The emitters can be reworked again although it makes it more difficult to see the anode/cathode when it is covered in solder. You can lay the emitters on the hot plate and push them to get the excess solder off.
I have taken the next step and I am having boards made for me with accuracy because I am going to sell some, but this technique aloud me to test a lot of recipes and learn a ton about LEDs in general.
I can run 3 of these boards (36 emitters) with a HLG-185-2100B but peaked out they are running about 6-7 watts each that way and hot. It is possible though but I think 1400mA is the way to go with these Osrams.
I usually ordered cut tape but with a full reel the emitters end up costing like 50 cents a piece.
 
justsmokedope

justsmokedope

Well-Known Member
just wondering why your not running them at 1000ma these can handle 1300ma on the data sheet
ive got my setup running at close to 1000ma wiring each board up parallel and using a 36v driver thats got 2.8a that runs 3 boards , but you can do the same by using a driver with even higher amps like a 6amp one runs 6 boards or slightly higher
or you could run all 12 on 1x 36v 12a amp driver setup in parallel
 
NaturalFarmer

NaturalFarmer

Well-Known Member
I have been testing these out and currently have them running on 2100 mA but then run them at about 60%. Heat becomes the issue with these when running high. Osram has surge curent listed at 2000mA although I get mine to pop at 3300mA

700 mA no issues at all and a good amount of light considering the draw. I am limited to what drivers I have on hand though but I have a hunch that there is a peak of benefit/cost to operate around 1000-1500mA and anything beyond is just money in the electric companies pocket.
 
Last edited:
justsmokedope

justsmokedope

Well-Known Member
NaturalFarmer said:
I have been testing these out and currently have them running on 2100 mA but then run them at about 60%. Heat becomes the issue with these when running high. Osram has surge curent listed at 2000mA although I get mine to pop at 3300mA

700 mA no issues at all and a good amount of light considering the draw. I am limited to what drivers I have on hand though but I have a hunch that there is a peak of benefit/cost to operate around 1000-1500mA and anything beyond is just money in the electric companies pocket.
Click to expand...
My design is loosely based on the cree horticultural design but i added xtra blues and some 625nm reds so it has 4000k white ,450nm royal blue , 625nm and 660nm reds and there's 14 sink pad 1950 s with optics and ive built 2 of them well nearly just waiting on a few more reds as was a few short .
Also the spec is a bit different as there are about 50% older cree leds as i half built it last year and also 50% new spec leds that are about 20% more efficient, so should hopefully be an improvement on cree hort design . although the all white boards can run up to 3000ma im keeping every thing at about 1000ma as this was what the cree hot design had with some good numbers and they were comparing it to a 1000w gavita . i recon even though i have 2 less boards per light because of the 20% increase in efficiency and extra umol s the lights should still be close to the 1000w gavita but they run at less than 600w each


how do you find osram leds do you think they are better than cree are they cheaper?
 
justsmokedope

justsmokedope

Well-Known Member
VegasWinner said:
man this is so cool. IF I had smaller hands I would consider. I build a lot of stuff. Right now a 3d printer. My ole lady laughs every time she hears screws, nuts, ect hitting the floor, slipping between my fat fingers. I am skinny guy, but my Dad was 7' tall with big hands over 300 pounds easy. Me not so much heavy but I have the hands not the wight. LOL.

I had to do PCB made by others because my fingers are too fat. lol I really li9ke reflow work too. nice work, looks excellent. love the DIY is everywhere now.

Do you guys buy diodes in reels or how ?
Click to expand...
thought you did make your own , its not about small hands you need steady hands and tweezers
 
Last edited:
NaturalFarmer

NaturalFarmer

Well-Known Member
I am indifferent between Cree and Osram and think both are quality. The Osrams are cheaper and smaller to work with ie. more of a pain in the ass at times. I would love to see an apples to apples comparison on output though. At .51cents Im sold on the SSL80s but the 660nm reds are only in 120 degree domes now.
 
Last edited:
V

VegasWinner

Well-Known Member
justsmokedope said:
thought you did make your own , its not about small hands you need steady hands and tweezers
Click to expand...
I use tweezers and that is most difficult, plus I have old man eyes to boot. I have others make them, I just design them. I do my own electronics for my controllers I make them from scratch but screws are always on the floor. I spend as much time on my hands and knees looking for small parts as I do sitting working with the small parts. lol
 
justsmokedope

justsmokedope

Well-Known Member
VegasWinner said:
I use tweezers and that is most difficult, plus I have old man eyes to boot. I have others make them, I just design them. I do my own electronics for my controllers I make them from scratch but screws are always on the floor. I spend as much time on my hands and knees looking for small parts as I do sitting working with the small parts. lol
Click to expand...
its alot harder if you do it after a gym session too lol , ive been on a mission today i placed and reflowed over 20 boards its actually very relaxing , i just need my 30 660nm reds noe to finnish the second light

for one of my next projects im prob going to have to build a pnp machine prob one of open pnp as to have loads placed seems to be really expensive and ill need to place hundreds of lm561c leds on one board
 
Last edited:
You must log in or register to reply here.
Top