Does anyone know where I can find/obtain a 2x2 6363 LED PCB?

[Stefano]

Very technical question, I hope it is appropriate to ask it here.

 

I have a lot of projects in my to-do list, most of them will require a lot of money and it will likely take years before I can do them. One of this projects is a ~8-10 W 340 nm LED illuminator, to include it in my ~10 W LED collection.

 

High power 340 nm LEDs are (oddly) all very similar, if not exactly the same. The one I already have is identical to this one: https://www.ebay.it/itm/202120730112 (the original listing is not there anymore).

 

What I want is a PCB where I can solder four of those LEDs in a 2x2 square. Such PCBs are already available for smaller 3535 LEDs, such as my 265 nm LEDs.

 

Example (there are many): http://kaidomain.com/20mm-x-1_5mm-Quad-DTP-Copper-PCB-for-4-x-Cree-XP-series-or-3535-LEDs-2pcs

 

There are even bigger ones if you want: https://www.kiwilighting.com/5-channel-25led-spots-3535-pad-led-pcb-board-printed-circuit-board-for-cree-xpe-xte-xpg-xpl-xhp35-epileds-3535-led-beads

 

but I didn't find a single one to hold four 6363 LEDs. I understand that four of them can not fit into a 20 mm star PCB, one of the most commonly used, but size doesn't really matter. What matters is that the LEDs are close together, as close as possible.

 

If someone finds one or a way to obtain one, please tell me.

 

Thanks.

[colinbm]

Me too, please.

[dabateman]

Stefano,

It doesn't hurt to look for a seller on Ebay from China with lots of various stuff listed (someone whom thus makes the stuff) and ask a question if something can be custom made. I have done this for filters and fused silica lenses.

You can get the range from a small batch size that you may need to order with an acceptable price to unrealistic single cost. But it can be done.

[ulf]

The material (copper, 2mm) used in the link for the big one above would be ideal for optimal heat transport.

The reason for those types of LEDs having such big casings is that they are more heat sensitive than other LED types and that almost all supplied power will end up as dissipated thermal energy into the component.

 

I have no source for custom manufacturing of copper based PCBs like that.

It would be interesting to find such a source for future needs.

 

I have seen prototyping production with 1.6mm Aluminium boards.

There the startup cost was around €120 when I set the project calculator for the board area to very small and increasing it a bit did not change the calculated price much.

On top of that there will be shipping costs.

If I remember correctly the site was in the western world and if some site is found in China the cost could be lower.

The prices in the links above are that low because of the produced volume of those boards.

Then it is more the cost of the raw material that affects the price as the preprocessing costs are diluted over many boards.

 

A layout for such a board is very easy to design with the right tools and knowledge.

Then production files needed for producing the boards is generated from the CAD-project.

The file formats are rather standardised and the board manufacturers pre-processing departments are good at handling varints.

 

Next potential problem is soldering the LEDs in a good way to the PCB. That cannot be done with a simple soldering iron.

[ulf]

I have a lot of projects in my to-do list, most of them will require a lot of money and it will likely take years before I can do them. One of this projects is a ~8-10 W 340 nm LED illuminator, to include it in my ~10 W LED collection.

I assume that you are aware of that four of those LEDs in your first link only can give a maximum of 0.22W optical power when you feed such an array with 8W, if the specification posted is true.

That is not very much power for illumination, compared the output of the 365nm LEDs we are used to.

 

These power LEDs are sensitive to over-temperatures locally in the small chip, both during soldering and operation and also quite sensitive to static discharges.

 

Such fault situations can either kill the LED completely or decrease the efficiency or working lifetime drastically.

Just as when converting cameras it is important to be well informed and do things the correct way to get a good result.

[Stefano]

Yes, I know it. They are not powerful and are sensitive. One way to prevent static discharges is perhaps to keep the terminals shorted when not in use.

 

Soldering is probably not something I will do myself. I know of a local place where they do this, but I don't know how much it will cost.

 

Thanks all for the advice so far. As I said, this is not something I will do in the near future (four of those LEDs are expensive), but I will look for the components already.

[ulf]

Good.

My intention was not to nag, sorry if it came out like that, but to make sure that such expensive components was not wasted, by bad procedures or ignorance.

[Stefano]

You did the right thing by making sure I knew how to handle the LEDs. I already know my soldering iron is not good for this as well as my soldering skills, so I will let a professional do it for me.

 

---

Still, 220 mW may seem little (and in fact, it is compared to the ~1 W of a Convoy), but is more than enough for photography. Yesterday I ran my 340 nm LED without heatsinking at 150 mA, it became hot but not too hot, and this was enough to photograph some objects ~10+ cm away and I also checked my lenses at 340 nm (the Helios-44M-5 is not good there. In fact none of them transmits there). And that was about 15 mW, assuming a linear relationship between output power and current.

[ulf]

Two more things to be aware of are:

1. To get a significant intensity change you need a doubling of optical power output.
   
2. A doubling of the distance from the LED gives 1/4 of the intensity at the motif.
   

[Stefano]

Also, assuming my Chinese BG39 is comparable to actual Schott BG39, it transmits ~20% at 340 nm (2 mm thick). S8612 (2 mm) transmits 50% at 340 nm. That's significant, more than one stop.

[Stefano]

Just for fun, I just tried to take some photos. I really liked this one. LED at ~50 cm, running at ~90 mA (~20% power).

 

Full-spectrum Canon EOS M, Soligor 35 mm f/3.5, Chinese BG39 (2 mm) + ZWB2 (2 mm), in-camera WB done under sunlight.

f/3.5, ISO 800, 120.9 s exposure.

 

The lavender in the background is sunlight filtered by our UV-absorbing windows, the green is the 340 nm illumination. Objects are (from left to right) a lipstick, a block of cardboard and a transparent plastic object. I had to put a book to cast a shadow where the objects were, since otherwise I would have had lavender + green.

 

Imagine having 20x the power... I could expose for 6 seconds instead of 2 minutes.

[rfcurry]

Stefano,

 

Wouldn't it be easier, and less expensive, to buy from IRTONIXS and use their mounting service, e.g. https://www.irtronix...ion=Package6363 ?

Just a thought. I have no experience with them.

[Stefano]

The LEDs they have are interesting. The UVA ones have the same exact package as the majority of 340 nm LEDs you can find online, but they have four dies in one package instead of one. I remember seeing images of such LEDs online, but they are only available at 365 nm and above. If only someone made 340 nm LEDs this way...

 

It seems the manufacturer of those LEDs with those packages is Seoul Viosys. This makes me wonder another thing: are all those LEDs produced by Seoul Viosys? Thorlabs has the same LED too... so strange.

[aphalo]

I haven't used Seeedstudio Fusion myself, but I know an electronics engineer who uses their services for prototypes. Nowadays they have boards with aluminium core as an option.

 

https://www.seeedstu...com/fusion.html

 

About soldering SMD LEDs to metal core PCBs: Has any of you tried the MHP30 Mini Hot Plate (available in AliExpress)? I ordered one some days ago...

I will start by practicing with some cheap non-UV SMD LEDs.

 

This is the description at the site of the manufacturer: http://www.miniware....late-preheater/

 

They also make the TS100 soldering iron that I have found to be excellent: http://www.miniware....-soldering-kit/

(The TS100 is not the right tool for SMD LEDs, but for other uses it beats much larger soldering stations.)

[Stefano]

Seoul Viosys's CUD4AF1B LED seems to be the one I have and Thorlabs has. Thorlabs's 340 nm LED is identical, but I didn't find any reference to Seoul Viosys in the spec sheet. It is very hard to find information about this LED, everything is so confusing.

 

Anyway, they also make modules, custom modules too, but I bet they are expensive, as they have to design it for you.

 

Edit: corrected a typo

[ulf]

About soldering SMD LEDs to metal core PCBs: Has any of you tried the MHP30 Mini Hot Plate (available in AliExpress)? I ordered one some days ago... I will start by practicing with some cheap non-UV SMD LEDs. This is the description at the site of the manufacturer: http://www.miniware....late-preheater/

 

I have a MHP30 Mini Hot Plate and am really impressed with it.

It is ideal for soldering small PCBs with components on just one side, like these metal core boards.

I bought mine with the power supply.

[ulf]

The soldering iron Pedro refers to looks good, from what I can see in the specs.

 

One of the good things with the TS100 / SQ001 is that each soldering tip has its own integrated heating element and temperature sensor and just connect electrically to the handle.

That is a similar principle used by professional soldering stations from JBC that cost ten times as much.

The JBC station pens can have the tips exchanged by just pulling them out and pushing the new one in and are very fast at heat up.

The TS100 / SQ001 has a similar standby setting as the JBC.

 

To utilize the full functionality of the TS100 / SQ001 it is important to have access to a power supply, with an output of 24V and > 65W.

 

There is an upgraded version called SQ001

https://it.aliexpres...22%2315392%2329

I am almost tempted to buy one, and then get a version with many different tips.

Just as with camera lenses, filters, step rings and lens mount adapters, you cannot have too many soldering devices.