XP series hand soldering

Can the Cree XP series be hand soldered. It looks like it has pads on the top. I know that you can electrically isolate the bottom pads of the Rebel and scrape a bit of the top off and solder directly to the pads but is it the same for the XP LED? I know that those pads are freaking tiny but if it is possible to solder from the top I think I have the skill to do so. I wish to solder to the top because I am not a fan of MCPCB. They take up too much space and don't conduct heat as well as if you attach the LED straight to a chuck of aluminum.

Look forward to the responses,
Spencer

I did it once. It's just freaking hard but it's possible . There is a thin layer of some kind of isolation on top of the small pads. You have to really carefully remove this layer I did it with a sharp knife. Then I used thin silver wiring and glued it in with Arctic Alumina after soldering to protect the wires. So it is possible but you have to be really carefully with the wiring as the connections easiely breaks off.

rayman

Good to know. Thank you.

how big is the mcpcb you are soldering it to, and how many watts soldering iron? If mcpcb to soldering iron power ratio is high (?) enough (meaning, if mcpcb is small, don't need as high a watt iron, but if mcpcb is medium sized, you'd need a good iron)

It's possible to reflow these with an iron, just up to you which method you are willing to try, which method you are most confident with.

I'm interested in eliminating the MCPCB. I haven't tried but reflowing doesn't look too hard.

thanx for info Rayman, that's news to me.
Be interested to see how it works out for you Spencer, please post a pic.

No projects are planned right now but its good to know. I'll post my progress when I actually do it.

Another thought I had is that optics probably won't fit well over the wires if you do solder to the top. Thoughts on this?

Yes forgot to say this. Thats kind of a problem but depending on how you solder it this will be a small or big problem .

rayman

Soldering directly to an XP-G can make sense for applications such as building a mini-tower for the SureFire Executive series head or the SureFire Z46 head. The bulb envelope for an MN03, for example, is about 4.5mm wide. The substrate dimensions for an XP-G are 3.45mm x 3.45mm, which is small enough to sit on top of a tower and fit through the reflector opening.

yeah I was going to say...you could take the optic before you solder and place it over the led and map out the best path for your wires. Depending on the optic you have there will be more or less room. You may be able to file the leg on the optic to provide the wire with a small path...

I guess you will just have to have your parts in hand and do some test fitting.

I have a DX XP-G "R5" drop-in and the XP-G LED decided it didn't want to stay attached to the MCPCB.

I've verified the LED is still functional, I just need to reattach it to the MCPCB.

With some solder paste, would it be possible to reflow solder the LED using my 25W Weller soldering iron?

Black Rose said:

I have a DX XP-G "R5" drop-in and the XP-G LED decided it didn't want to stay attached to the MCPCB.

I've verified the LED is still functional, I just need to reattach it to the MCPCB.

With some solder paste, would it be possible to reflow solder the LED using my 25W Weller soldering iron?

Click to expand...

That will easily work. In modding one of my fenix E1s with an XP-E, I had done the reflow with nothing more than a bic lighter . Came out perfectly.
AZ

Off topic...these replies have answered most of my Q's about the XP-G...but I'm getting conflicting info on the max current. Is it 1.0 or 1.4 amps?

It's 1.5A. Read the datasheet.

Justin Case said:

It's 1.5A. Read the datasheet.

Click to expand...

I know you tell me to read the datasheet. The data sheet says:

"Maximum drive current: 1000 mA "


But I've heard you guys say 1.5A. This is why I ask. The datasheet says 1A and you say 1.5A. Why the difference?:thinking:
And I've never heard of the R5 being rated at near 600lm, but if you devide 1.5A by 350mA and multiply by 139lm...you get 595.7lm. I'm assuming it becomes less efficient at high amperage then?



I'm looking at this board:

4 x CREE XP-G R5 on round PCB
4 x Cree XREWHT-L1-1T-R5 on round PCB

Diameter: 34.0mm
Viewing Angle: 125°
Emitting Color: white
Lumen min.: 556
Lumen max.: 1480
Kelvin min.: 6000
Kelvin max.: 6500
mA test.: 350 mA
mA typ.: 350 mA
mA max.: 1000
mAV typ.: 14
VV max.: 16
VWatt: 4,9 W


It also says mA max.: 1000mA

I just don't want to fry a $45 pcb of LED's.

chelboed said:

I know you tell me to read the datasheet. The data sheet says:

"Maximum drive current: 1000 mA "


But I've heard you guys say 1.5A. This is why I ask. The datasheet says 1A and you say 1.5A. Why the difference?:thinking:

Click to expand...

If you go to the Cree XLamp LED page you'll see a small blurb on the right hand side mentioning the increase. You can read the entire press release here.

There was a CPF thread about this in the LED section titled New current ratings for XP series lamps!

chelboed said:

I know you tell me to read the datasheet. The data sheet says:

"Maximum drive current: 1000 mA "


But I've heard you guys say 1.5A. This is why I ask. The datasheet says 1A and you say 1.5A. Why the difference?:thinking:
And I've never heard of the R5 being rated at near 600lm, but if you devide 1.5A by 350mA and multiply by 139lm...you get 595.7lm. I'm assuming it becomes less efficient at high amperage then?

Click to expand...

The max drive current is 1.5A. You need to look at the current version of the Cree XP-G datasheet. It isn't rocket science. Try typing in "cree xp-g" into Google. Perhaps you will find this link: http://www.cree.com/products/xlamp_xpg.asp Read that web page and open the PDF of the datasheet. See P. 1, Features. Note the feature "Maximum drive current: 1500mA".

Read the datasheet to estimate emitter lumens at 1.5A. Your approach is wrong. Emitter lumens isn't scaled simply by taking 1.5A and dividing it by 350mA. You need to look at the graph of relative luminous flux vs drive current in the datasheet.

You really need to read the datasheet -- carefully.

As for frying an LED, you can fry one without driving it at the maximum current. Proper heat sinking is the key to running any high powered LED successfully. The 1.5A max spec doesn't mean that you can simply power up a bare XP-G at 1.5A and expect smooth running. You need to heat sink the LED.

furthermore, CPF has a great tradition of driving emitter at beyond the spec'd drive sheets.
JTR's whitelumentesting is an excellent resource for outputs beyond.
As mentioned, excess heat is a caution

chelboed said:

...I'm looking at this board:

4 x CREE XP-G R5 on round PCB
4 x Cree XREWHT-L1-1T-R5 on round PCB...

Click to expand...

Are you planning on using the 23° quad-optic with that, or have you found something suited to that board that will create a tight spot? (I've been wanting to do a quad XP-G, but can't find Regina reflectors anywhere.)

Justin Case said:

The max drive current is 1.5A. You need to look at the current version of the Cree XP-G datasheet. It isn't rocket science. Try typing in "cree xp-g" into Google. Perhaps you will find this link: http://www.cree.com/products/xlamp_xpg.asp Read that web page and open the PDF of the datasheet. See P. 1, Features. Note the feature "Maximum drive current: 1500mA".

Read the datasheet to estimate emitter lumens at 1.5A. Your approach is wrong. Emitter lumens isn't scaled simply by taking 1.5A and dividing it by 350mA. You need to look at the graph of relative luminous flux vs drive current in the datasheet.

You really need to read the datasheet -- carefully.

As for frying an LED, you can fry one without driving it at the maximum current. Proper heat sinking is the key to running any high powered LED successfully. The 1.5A max spec doesn't mean that you can simply power up a bare XP-G at 1.5A and expect smooth running. You need to heat sink the LED.

Click to expand...

Regarding heat...I am definitely expecting to move some heat. I had to add an R/C motor heatsink to my SSC P7 build so it will run cool. It actually runs quite cool now at 2.8amps, room temp, with a fan on low. Riding pace is more than adequate.

When I typed XP-G into Google...the 1000mA was what I got. Why would I need to assume there is more than one datasheet floating around out there, right? :sick2: I never actually read anywhere on any datasheet where it said 1.5A, so this is why I asked you guys. I know you can go beyond mfgr spec's on many things in this world...I assumed that this was just one more.

Now regarding reading the datasheet "very carefully"...I know basically nothing about electronics. I don't understand current, voltage, luminous flux in relation to eachother...any more than a basic tinkerer in his basement. I am handy though. I can learn. I know that I shouldn't drive my P7 above 2.8amps, (learned the hard way) so I bought two 3.7v / 1.4amp 17mm circuit boards and soldered them together to get 2.8amps to the emitter. I was able to do that just fine from reading the schematics from hoffmanamps.com.

It doesn't mean that I understand all the graphs and the datasheet for the emitter. I'm trying, truly. I want to get it all in. I just have enough experience to build my P7 light and wire a new circuit on my breaker box for my house. I've installed a car stereo before.

I'm an electronic-infant. This is why I ask the Q's.

Thanks for the info though. I'll keep researching. I'll read the datasheet again. (thanks for the link)

Techjunkie said:

Are you planning on using the 23° quad-optic with that, or have you found something suited to that board that will create a tight spot? (I've been wanting to do a quad XP-G, but can't find Regina reflectors anywhere.)

Click to expand...

I was planning the 23° optics until I decided to go slightly smaller. I'm gonna build a 3x XP-G R5 instead. It has integrated optics and driver board. Should be somewhere around 1100lm at the emitter according to the developer which would probably give me 700'ish OTF.

Nice thing is that it's all integrated in a 20mm x 8mm package. I'll run the wires out the back and the entire body of the light will be a heatsink. I'll mill some fins in it of course. Heat shouldn't be an issue. If it is, I'll go a little bigger on the body or install a micro heatsink fan from one of those R/C projects.