Luminus SST-40, a N4 BA bin tested

you may need to bake them a while to drive out moisture if they are popping during reflow.
i salvage lots of these fets from junk laptop boards without problems so you may simply be getting them too hot.
edit.
these are msl 1 so unlikely to popcorn.

Dale and I pm'ed bout it. I can't recall one SIR404DP I've blown actually, and I've done a ton of them. I use them for every multiple LED light, or multi-die light that has full FET max output. The difference of 30 cents or so from an SIR800DP is a drop in the bucket.

But I understand hesitancy in using them if you've been popping a couple - not sure why though.

You guys probably know this (I did not though when I started reflowing) , but for reflowing any board, you can't just use hot air from above - you have to have a heat source below (according to all the pros, otherwise you don't get properly formed bonded solder bridges) - I use a coffee mug warmer that brings it up to close to 100C. Let the board sit on it for a few seconds - prefer getting the solder paste to spread, then to turn dry, and then apply the hot air from above, and want to use the minimum heat needed, so it will take a few seconds at a min to get the solder flowing.

I think for parts like a FET, the heat from below is important since it has the big hidden pad under it.

yes the heavy copper pad it sits on must reach soldering temp.
i use a homebrew preheater.
its an electric griddle powered by a variac.

Yep, electric griddles must be common to use. My EE buddy here also uses one at home with an adjustable temperature for doing his own boards. He upgraded from his coffee mug warmers because he needed something bigger, so he gave me his old warmer. If I was doing a bit larger scale batches, I would definitely invest in one.

If you want to catch a FET, you must think like a FET.

Confusion

For those in the NY metropolitan area, I was in Ace Hardware (Massapequa Store) and spotted Ace brand toluene in 1 Gallon cans marked down from $19.99 to $6.50. I don’t know if this a chain-wise clearance or local the this particular franchise owner or just this store. This was old stock with rust on the cans so possibly this store manager decided to move them out.

I graduated from Massapequa High, grew up there by the "All American" It's about 15-mins aways, I should check it out. Thanks!

I was at the Hicksville Rd store, not Merrick Rd. Good luck!

Gee, a gallon of Toluene for 6½ bucks…
I finally got my 1 Liter in today, 24 bucks shipped from Germany.
Had to fill out a signed end user declaration and a copy of my ID before they sent it.
But i got the >99.5% stuff.
The smell even creeps through the bottle cap… :person_facepalming:

Good Luck! :+1:

What’cha going to try and de-dome first Jer?

2x SST-40.
I bought them to dedome them basically. :smiley:
One will go in a modded Solarstorm SC01 (8x 7135) 14500 ‘mini thrower’.
The other one in an aspheric, probably my B158 on 4.5 Amperes CC FET driver.
I have a bunch of XP-G2 LEDs too, old and new, and a bunch of XM-L2, also some XP-E2.
Good to have the stuff in stock for future plans.

What is your plan of attack de-doming the SST’s?

The others will be easy….

I think i’ll put them in a small sealable container, room temperature, shake container gently a couple of times.
Periodically check how it progresses.

I don’t think there’s any need to pay the premium for reagent grade toluene, solvent grade should serve well enough IMO. I guess they want to ensure you’re not making bathtub TNT. :smiley:

Maybe, but this was the only thing i could find under € 20.— shipped.

Sorry, if I dont want to read the full thread.

Is it possible to dedome this LED with Nitro or other chemics?

With the low forward voltage, it would seem this should be a great led for regulated multi emitter lights. Its not a lot less watts, but over several emitters it adds up. Less heat, slightly more run time. Sounds good to me.

Hmm, if somebody made a mcpcb for these in a 20mm triple……… With a fet driver could be interesting as well if they push that much easier than xp-g3’s do.

After checking my Ali sst-40s I realized they are b grade, half have bubles in dome and some are not square but wider and centering dics not fit them.
KD is better place to buy, better bin, higher price though.

Were your LED’s mounted on mpcb’s? or were they bare. I’m still contemplating getting a few of these.

I think those shops on aliexpress did not sale bare leds only with mcpcb at least there were no bare leds where I bought them (SST-40).