Author Topic: Make a cool case out of PCB only (Read 56398 times)

electrodacus · « **on:** February 25, 2015, 03:17:03 am »

I decided to share my Solar BMS case design made exclusively from PCB's only.
Most are FR4 except for the PCB at the bottom that is a metal core PCB.
People mostly use metal core PCB's for power LED's but this are really great for high power electronics no idea why not more people use them.
Anyway the case is made on that 2.5mm Aluminium metal core PCB for the power components then there are two spacers or 1.6mm FR4 followed by the main board with all the smaller parts then another two FR4 1.6mm spacers and on top the front PCB with the capacitive buttons and cut out for the LCD.
This is really great since it can be mounted on a larger heatsink able to take that 20W max TDP if the Solar BMS (Battery Management System) is used at full load.

My new design will use a very similar construction but a bit more complex with about double the number of parts for the case.

Here are some photos that should make things more clear.

calexanian · « **Reply #1 on:** February 25, 2015, 03:28:57 am »

I like it.

electrodacus · « **Reply #2 on:** February 25, 2015, 03:32:13 am »

Quote from: calexanian on February 25, 2015, 03:28:57 am

I like it.

Thanks. Maybe more will use something similar for small compact electronics.

tszaboo · « **Reply #3 on:** February 25, 2015, 11:10:08 am »

That looks absolutely amazing.
The main reason that this is not widespread, I think, is the price of enclosures. A hammond extruded box costs about 50% more at 100 pieces as a Eurocard IMS PCB, at least that is what I've calculated just now. Did you solder the standoffs on the IMS somehow, or are these special standoffs?

electrodacus · « **Reply #4 on:** February 25, 2015, 05:27:27 pm »

Quote from: NANDBlog on February 25, 2015, 11:10:08 am

That looks absolutely amazing.
The main reason that this is not widespread, I think, is the price of enclosures. A hammond extruded box costs about 50% more at 100 pieces as a Eurocard IMS PCB, at least that is what I've calculated just now. Did you solder the standoffs on the IMS somehow, or are these special standoffs?

Mersi

It depends how you calculate the cost this is actually extremely inexpensive because you need those 3 PCB's anyway for the capacitive buttons the main PCB and the power PCB so only those smaller PCB's with no traces are needed (in some applications you can have those made of acrylic or similar things but I need FR4 just to be sure is fire proof)
Here is a photo I managed to find from the back and a closer look from the front

Also my new design is at the moment just a 3D render made all just of PCB (much more PCB's almost 2x)

electrodacus · « **Reply #5 on:** February 25, 2015, 05:36:37 pm »

Quote from: 3roomlab on February 25, 2015, 05:32:51 pm

i like too

Thanks. PCB manufacturers also love it

ajb · « **Reply #6 on:** February 25, 2015, 07:08:13 pm »

That's very slick. I'm a big fan of the clear mask and black silk you chose as well.

What are you using for board-to-board connections?

electrodacus · « **Reply #7 on:** February 25, 2015, 07:17:27 pm »

Quote from: ajb on February 25, 2015, 07:08:13 pm

That's very slick. I'm a big fan of the clear mask and black silk you chose as well.

What are you using for board-to-board connections?

I use some small 60pins connectors not the best choice but those where 3.2mm thinners I needed for this version also a bit expensive.
I will be using spring contacts for the next version the advantage is that you do not need all traces routed to a connector on a one layer board like the aluminium metal core PCB. I can have each spring where I needed in contact with the main board above that will be 4 layers this time. I have much more components and I hope the quality of 4 layer will be better especially for that annoying 0.4mm QFN package that I have.
The bottom layer will only have those about 12 gold plated pads or so that will contact with the springs mounted on the power board.

Wilksey · « **Reply #8 on:** February 25, 2015, 09:58:46 pm »

That looks very good, quite eye catching!

Top job!

hamdi.tn · « **Reply #9 on:** February 25, 2015, 10:10:10 pm »

i like the design but is that board really passing 77A and charging with around 40A !!!

electrodacus · « **Reply #10 on:** February 25, 2015, 10:18:33 pm »

Quote from: hamdi.tn on February 25, 2015, 10:10:10 pm

i like the design but is that board really passing 77A and charging with around 40A !!!

Yes it dose and the new design can charge with 120A while at the same time discharge with 120A and the total TDP in that case is just 22W
I use the best technology available to get to this performance levels.
Happy to talk about more since is open source.
You need to mount the Solar BMS on a small passive heat sink able to dissipate those 20 to 22W without any heatsink it can only do half that 20A charging and 40A discharging on the old version.
The charging was just 26A when I took that photo (I have just 3x 240W PV panels connected) and discharge as you see 77.8A.

electrodacus · « **Reply #11 on:** February 25, 2015, 10:24:07 pm »

Quote from: Wilksey on February 25, 2015, 09:58:46 pm

That looks very good, quite eye catching!

Top job!

Thanks.

kingofkya · « **Reply #12 on:** February 25, 2015, 10:26:28 pm »

Interesting, out of curiosity is pin that dissipates heat. Are they electrically connected to the aluminum or does it go though some kinda insulator in the pcb..?

kurt · « **Reply #13 on:** February 25, 2015, 10:30:05 pm »

That is a really nice looking design. And I love the creativity in construction

electrodacus · « **Reply #14 on:** February 25, 2015, 10:31:31 pm »

Quote from: kingofkya on February 25, 2015, 10:26:28 pm

Interesting, out of curiosity is pin that dissipates heat. Are they electrically connected to the aluminum or does it go though some kinda insulator in the pcb..?

Hi the way metal core PCB is build is like this. A 2.5mm Aluminium plate in my case then a 0.1mm layer of Teflon and then your copper layer so no electrical contact between your pads and aluminium plate but a really good thermal transfer do to that thin 100um layer of Teflon.
I hope more people to find about this and work with this.

electrodacus · « **Reply #15 on:** February 25, 2015, 10:34:00 pm »

Quote from: kurt on February 25, 2015, 10:30:05 pm

That is a really nice looking design. And I love the creativity in construction

Thanks. Maybe more people get inspired by this deign.
The cost is better also than any alternative for 100+ units.

hamdi.tn · « **Reply #16 on:** February 25, 2015, 11:13:29 pm »

Quote from: electrodacus on February 25, 2015, 10:18:33 pm

Quote from: hamdi.tn on February 25, 2015, 10:10:10 pm
i like the design but is that board really passing 77A and charging with around 40A !!!

Yes it dose and the new design can charge with 120A while at the same time discharge with 120A and the total TDP in that case is just 22W
I use the best technology available to get to this performance levels.
Happy to talk about more since is open source.
You need to mount the Solar BMS on a small passive heat sink able to dissipate those 20 to 22W without any heatsink it can only do half that 20A charging and 40A discharging on the old version.
The charging was just 26A when I took that photo (I have just 3x 240W PV panels connected) and discharge as you see 77.8A.

thanks for info

since it's an open source is it possible for you to share schematics on the blog

electrodacus · « **Reply #17 on:** February 25, 2015, 11:18:00 pm »

Quote from: hamdi.tn on February 25, 2015, 11:13:29 pm

Quote from: electrodacus on February 25, 2015, 10:18:33 pm
Quote from: hamdi.tn on February 25, 2015, 10:10:10 pm
i like the design but is that board really passing 77A and charging with around 40A !!!

Yes it dose and the new design can charge with 120A while at the same time discharge with 120A and the total TDP in that case is just 22W
I use the best technology available to get to this performance levels.
Happy to talk about more since is open source.
You need to mount the Solar BMS on a small passive heat sink able to dissipate those 20 to 22W without any heatsink it can only do half that 20A charging and 40A discharging on the old version.
The charging was just 26A when I took that photo (I have just 3x 240W PV panels connected) and discharge as you see 77.8A.

thanks for info since it's an open source is it possible for you to share schematics on the blog

Yes but this is more about the case if there is an interest in the solar BMS I can open another thread about that or actually use the one in the Open Source projects
This was a successful Kicstarter project last year so if you search for Solar BMS on Kickstarter and look at my first version not this new one you will find updates and in the latest updates there are links to both software and schematic.
Hope Dave will not delete this as considered advertising.

janaf · « **Reply #18 on:** February 26, 2015, 12:47:57 am »

Neat design! Nice to see the creativity!

Her's a link to a company that even buries the components inside multi-layer boards. For me, it fell on the cost of making prototypes

http://www.hofmannlp.de/fileadmin/dokumente/Hofmann_AML.pdf

electrodacus · « **Reply #19 on:** February 26, 2015, 12:58:37 am »

Quote from: janaf on February 26, 2015, 12:47:57 am

Neat design! Nice to see the creativity!

Her's a link to a company that even buries the components inside multi-layer boards. For me, it fell on the cost of making prototypes

http://www.hofmannlp.de/fileadmin/dokumente/Hofmann_AML.pdf

Thanks for that link. Looks interesting but is probably expensive to even in larger volumes. A single layer metal core PCB will perform probably better at keeping the component temperature lower and cost way less.
In fact it cost about the same as a regular 4 layer PCB at least for my small volume and thick 2.5mm Aluminium with less thick aluminium it will probably be a bit less.

janaf · « **Reply #20 on:** February 26, 2015, 01:16:18 am »

Are ALU boards available with plated through holes? Or just for surface stuff?

electrodacus · « **Reply #21 on:** February 26, 2015, 01:24:30 am »

Quote from: janaf on February 26, 2015, 01:16:18 am

Are ALU boards available with plated through holes? Or just for surface stuff?

This are for surface parts only with a single layer. There are dual layer and some more exotic metal core PCB's but those are not used as much so more expensive and you don't get this great thermal transfer as with this one layer surface mount boards.
Also if you use true hole then the ability to mount this on a larger heat-sink is not there do to protruding pins.

laneboysrc · « **Reply #22 on:** February 26, 2015, 01:29:35 am »

What an awesome idea, thanks for sharing!

I made good use of it in one of my hobby projects, photo attached.
I originally had planned to solder the layers together using solder paste and hot air, but I ended up using a drop of Epoxy instead.

cheers, Werner

electrodacus · « **Reply #23 on:** February 26, 2015, 01:33:59 am »

Quote from: laneboysrc on February 26, 2015, 01:29:35 am

What an awesome idea, thanks for sharing!

I made good use of it in one of my hobby projects, photo attached.
I originally had planned to solder the layers together using solder paste and hot air, but I ended up using a drop of Epoxy instead.

cheers, Werner

Thanks, it seems to be the same general idea not sure why not more people use this.

matt6ft9 · « **Reply #24 on:** February 27, 2015, 09:31:52 pm »

great design!
What software did you use to make the animated gif/3D model/PCB layout?


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Author Topic: Make a cool case out of PCB only (Read 56398 times)

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