Reflow soldering

[Artificialsun]

A small portion of my diodes keep wanting to float away. I have great luck with most of them, but some go nuts and end up wonky. What is going wrong here? Do I need to use adhesive to secure them before going in the oven? I am currently soldering the thermal pad at the same time as the anode and cathode. I am currently soldering 561Bs onto mcpcbs, using a toaster oven I converted into a reflow oven. I’ve made several great boards but I want consistent perfection if it’s attainable. I searched high and low and got an incredible deal on these, hence the journey into fabrication.

[unkle_psycho]

Wow!

[ATPinMotion]

Hehe, interesting problem! Sheet of polycarbonate + gravity? I love making fixtures, but simplicity is beautiful

[Artificialsun]

Yep that’s where I ended up. I just lay out all the diodes in paste and ever so carefully lay a blank board on top before starting the oven. I bought a bulk order of MCPCBs and LEDs. The end result are electrically clones of the qb288, just arranged a bit differently. ~150 total if I ever get done with all of them.(currently on 20ish) I’m going for essentially a seamless sky of light over the canopy, with varying levels of intensity but all liberally underdriven. Went with LM561B+ diodes on a few boards and thousands of 561C for the majority of my grow space, mostly in 3500K but some 3000K and 4000K also to see which design works best in my space, and if I can go for the cheaper diodes when I inevitably take over th entire basement. Hehe. Going head first into producing my own boards has made them so cheap individually that solder paste and flux are the most expensive components, just couldn’t find a way to make those any cheaper. Total cost of less than $10.00 per board, not including drivers. Total power use age for lighting should stay under 4kw as designed. Lol my wife thinks I’ve totally lost my mind but to me it’s a blast building them.

[polpus]

Sounds like a really cool project! Can I ask where did you get the MCPCBs from?

[Artificialsun]

Sounds like a really cool project! Can I ask where did you get the MCPCBs from?

Absolutely! I searched across the internet up one side and down the other, eBay, Amazon etc and nothing resembling a QB MCPCB seems available anywhere except Alibaba. I bought some sample boards from different manufacturers and didn’t have a major issue with any of them, Kingbrite was the most economical for the main order of 200 at the time of my purchase. My diodes were sourced from various suppliers. Some from EBay, some from DigiKey, some from Alibaba merchants. I tried some other sites but I have a tendency to not trust anything that I can’t prove. By my logic any chips that don’t arrive in original Samsung packaging to be unverified so I won’t recommend sketchy sources at any price.

[polpus]

Thanks for the info!

So Kingbrite sold you the bare PCBs? Did you design the PCBs yourself or did they have some ready made designs? How much were the 200 PCBs? What are the dimensions of each PCB?

Lots of questions, I know. Sorry! Thanks!

[Artificialsun]

Thanks for the info!

So Kingbrite sold you the bare PCBs? Did you design the PCBs yourself or did they have some ready made designs? How much were the 200 PCBs? What are the dimensions of each PCB?

Lots of questions, I know. Sorry! Thanks!

No problem! It’s pretty cool to be in an active forum, most folks that I interact with daily have no concept of what the actual fuck I’m doing or why bother with it in the first place. Yep, Kingbrite was the manufacturer that won me over. I bought small quantities from a few merchants, but price or the representatives demeanor turned me away from the others even though they offered sizes that Kingbrite doesn’t stock. If I remember correctly Kingbrite charged something like $5 each for the sample order and $4 each when I bought 200 boards. Shipping was far cheaper than I expected, and fast. All told to my door was under $1000 for the main shipment.