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Dotstar micro 2020 project
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Dotstar micro 2020 project

by zoilo on Thu Oct 12, 2017 6:05 am

Hi,

I am working on a project where I need a ring of 42mm external diameter and 31 inside diameter with 40 dotstar micro led.
I have designed my pcb, ordered through a professional and hand soldered because I don't have a smd oven nor time...
Now that the prototype "work" I need a more reliable product, a small series of 4 rings in total.

Because these small leds are very sensitive to : moisture, temperature, electrostatic, pressure and a lot of other stuff... I wandered if you can recommand me a company that do the pcb + assembly and know how to respect the dotstar micro characteristics given on the very very complete datasheet...
I already had to work with a company to do custom board ws2812b matrix and I had a lot of issues... (first batch half the leds was burnt, second batch half of them wasn't soldered...)
So I try to found a better solution

Thank you

zoilo
 
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Re: Dotstar micro 2020 project

by adafruit_support_mike on Thu Oct 12, 2017 11:42 pm

I get PCBs from Advanced Circuits, and have always had good luck with them:

http://4pcb.com/

They also have an assembly service, but I haven't haven't used that for anything related to DotStars or small, temperature-sensitive packages. You can talk to them and see if that's within their capacity though.

adafruit_support_mike
 
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Re: Dotstar micro 2020 project

by zoilo on Fri Oct 13, 2017 3:56 am

Thank you Mike,

I was hoping to have a contact of your manufacturer for the dotstar matrix like these https://www.adafruit.com/product/3444

I try with 4pcb.

zoilo
 
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Re: Dotstar micro 2020 project

by adafruit_support_mike on Sat Oct 14, 2017 12:41 am

We don't do any custom design or fabrication. Our fab and QA teams are already busy enough trying to keep up with the stuff we make ourselves. ;-)

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Re: Dotstar micro 2020 project

by zoilo on Mon Oct 23, 2017 7:37 pm

I can easily understand that...
I have contacted 4pcb and they are not very confident with the low temp solution they have.
Can you give me more details of witch solution your manufacturer use for these matrix?
Solder paste? temp profile?
We try to have the best result out of your tiny led's
Thank you again

zoilo
 
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Re: Dotstar micro 2020 project

by adafruit_support_mike on Tue Oct 24, 2017 1:21 am

We do our own reflow for things like the DotStar FeatherWing:

https://www.adafruit.com/product/3449

I don't know the specific temperature profile or solder composition, and we try not to talk about those in public because the numbers vary from one layout and oven to the next. Any time we do say something specific, someone cut-and-pastes the information, ruins a batch of hardware, and blames us for it.

I'll see if I can get any information about maximum working temperatures for the 2020 DotStars though.

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Re: Dotstar micro 2020 project

by zoilo on Tue Oct 24, 2017 1:39 am

I understand that never go to be the exact same setup.
It's more to have a starting point and tips or all the useful informations to have all the card on our hands.
These smart leds are very hard to solder to have a reliable board.

Thank you in advance

zoilo
 
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Joined: Thu Oct 12, 2017 5:50 am

Re: Dotstar micro 2020 project

by adafruit2 on Wed Oct 25, 2017 12:32 am

we use a standard Lead free process, you do need them to watch carefully because all LEDs are temperature/humidity sensitive. Other than that we have no suggestions - it *completely* depends on the board design and machines used!

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Please be positive and constructive with your questions and comments.