Well, i bought 2 SST-40 form AliExpress, and i put them in pure toluene…
The first one got the chip detached from the 5050 base, it seems it wasn’t soldered on there properly…
So it died in the toluene, but i almost managed to reflow the chip back on the 5050 base, but something went wrong, it didn’t work anymore…
Interesting discovery though, because i think you could reflow the chip directly on to copper, and find a way to connect the bond wires to ‘something near by’, improving the thermal path from chip to whatever copper you want.
But i’m not buying them from AliExpress anymore.
It seems they are factory rejects.
The second survived the ordeal, it is dedomed now.
I will try warm or hot toluene, because there are still some bits of silicone on the phosphor, even after leaving it in toluene for some 36 hours…
But i was afraid the bonding between chip and phosphor would dissolve, like someone described happening earlier in this (or another) thread.
So i will try solving at higher temperatures with the 2nd SST-40, see if i can get it totally clean.
Meanwhile i have one from KD too.
I’m sure the chip will not fall of off that one… :person_facepalming:
I got 1 half way decent one out of like 30, decent that the bond wires didn’t break, but still, silicone remains are hanging off the bond wires. All of the SST-40’s I got came from Kaidomian. I have 20 SST-40 N4 AD’s coming 12 of which are going to replace the XML’s in my TR-J20, the rest, I’ll try a different approach.
Not if you can see it in the beam. I think 18sixfifty has had some success, from what I gather, he slices and dices before chemical de-dome bath/soak.
The silicone dome has a heck of a hold on them bond wires. :rage: I have also had the chip coming off the pad on a few of them too! :person_facepalming:
Boost it’s pulling 8 amps on a VTC5A, I thought I had something wrong at first, cause it would only pull 6+ amps, until i put a fully charged VTC5 and then a tried a VTC5A . I just swapped out the emitter/board in my M25C2 Turbo that had a FETDDdrv. in it. It’s a pretty intense BLUE-ISH spot, just kinda fuzzy and dark to one side, like casting a shadow from the silicone clinging on. Meh, I live with it, because I know what will happen! :person_facepalming:
Dales shaves them down to just above the phophorus and he’s getting like 9.4amps or more 2400-2600 lumens, something like that.
Maybe or could be, if they are weak, they might be damaged, I had a few that would light, go thru the levels a couple times and then burn out, some instantly and they still had the dome on, it was released from the base just not completely off, so I’m left wondering, was it the bond wires or was it the chip to the pad problem? Dunno?
Wow, even some of those from KD have badly solder flowed chips??
There’s no way the solvents cause the chips to fall off i.m.o.
On mine you could see it wasn’t soldered properly.
It’s possible you will blow the bond wires from too much current (~9.5A) if it’s direct drive and low circuit resistance. What is the voltage configuration and driver? And have you used other cells in the light successfully?
Yes sir. The tk75vn is modded by Vinh. Probably drawing 4.5 amp from each cell… the Carrier is 4S… I like using Sony vtc5a. So far I have no problem using the highest mode with my vtc5a.
Either way, if the light break, he said he will fix it for free… so I don’t worry much…