"Phil Hobbs" <pcdhSpamMeSenseless@electrooptical.net> wrote in message news:pbmcc7$o4g$1@dont-email.me...> Yes, that's one approach I'm considering. The Cu-on-anodized-Al approach > is an interesting one as well. I could just put the transistors and sense > resistors on that, and let the low-power circuitry > stay on a regular PCB.What's wrong with multilayer, modest weight copper? I've got an 8 layer 2 ounce board that's almost impossible to work on. It takes five minutes of hot air before anything even begins to budge. I think a D2PAK could dissipate 10W on minimal pads (with thermal vias, mind). On the topic of exotica, have you considered ceramic PCB? There are a few shops doing it now, it doesn't look too expensive -- probably not more than what you proposed? Tim -- Seven Transistor Labs, LLC Electrical Engineering Consultation and Contract Design Website: https://www.seventransistorlabs.com/
Aluminum-core PCB cost?
Started by ●April 23, 2018
Reply by ●April 24, 20182018-04-24
Reply by ●April 24, 20182018-04-24
On Monday, April 23, 2018 at 10:31:59 AM UTC+2, Phil Hobbs wrote:> I have a customer who wants me to do an extreme shrink of our > semi-custom diode laser controller board, which leads to a lot of > thermal issues. The obvious approach is an aluminum-core circuit > board, but I've never used one. > > A few questions for the cognoscenti: > > 1. Can I get a 6- or 8-layer aluminum-core PCB? > > 2. How much more do they cost? > > 3. Any other constraints? >These guys are pretty cheap, almost the same as FR4: https://www.smart-prototyping.com/LED-Aluminium-PCB-Prototyping.html Cheers Klaus
Reply by ●April 24, 20182018-04-24
tirsdag den 24. april 2018 kl. 14.14.31 UTC+2 skrev Klaus Kragelund:> On Monday, April 23, 2018 at 10:31:59 AM UTC+2, Phil Hobbs wrote: > > I have a customer who wants me to do an extreme shrink of our > > semi-custom diode laser controller board, which leads to a lot of > > thermal issues. The obvious approach is an aluminum-core circuit > > board, but I've never used one. > > > > A few questions for the cognoscenti: > > > > 1. Can I get a 6- or 8-layer aluminum-core PCB? > > > > 2. How much more do they cost? > > > > 3. Any other constraints? > > > > These guys are pretty cheap, almost the same as FR4: > > https://www.smart-prototyping.com/LED-Aluminium-PCB-Prototyping.html >but only single layer
Reply by ●April 24, 20182018-04-24
On Tue, 24 Apr 2018 07:22:11 -0700 (PDT), Lasse Langwadt Christensen <langwadt@fonz.dk> wrote:>tirsdag den 24. april 2018 kl. 14.14.31 UTC+2 skrev Klaus Kragelund: >> On Monday, April 23, 2018 at 10:31:59 AM UTC+2, Phil Hobbs wrote: >> > I have a customer who wants me to do an extreme shrink of our >> > semi-custom diode laser controller board, which leads to a lot of >> > thermal issues. The obvious approach is an aluminum-core circuit >> > board, but I've never used one. >> > >> > A few questions for the cognoscenti: >> > >> > 1. Can I get a 6- or 8-layer aluminum-core PCB? >> > >> > 2. How much more do they cost? >> > >> > 3. Any other constraints? >> > >> >> These guys are pretty cheap, almost the same as FR4: >> >> https://www.smart-prototyping.com/LED-Aluminium-PCB-Prototyping.html >> > >but only single layer >I don't know Phil's requirements, but we sometimes use 1 oz copper pours on multiple layers (with lots of vias) as heat spreaders. Via to the bottom side then gap-pad to the enclosure. Or use the mounting screws as thermal exits. https://www.dropbox.com/s/11mhgj9oytttqjn/Gap_Pad.jpg?raw=1 -- John Larkin Highland Technology, Inc lunatic fringe electronics
Reply by ●April 24, 20182018-04-24
tabbypurr@gmail.com wrote in news:b354cef4-6b66-4739-8613-cc70c748a962@googlegroups.com:> On Tuesday, 24 April 2018 07:18:46 UTC+1, > DecadentLinux...@decadence.org wrote: > >> Screw the gap pad. > > not generally regarded as good engineering practice >Nice job of making an out of context trim, jackass. IF you knew how to read, you would have noticed that it gets replaced with a BETTER conducting thermal epoxy. Wake the fuck up and read. Casual glances at written works makes you a piss poor participant. Making out of context posts based on your petty, casual glances at what was actually written is even worse.
Reply by ●April 24, 20182018-04-24
On Wednesday, 25 April 2018 01:01:34 UTC+1, DecadentLinux...@decadence.org wrote:> tabbypurr wrote in > news:b354cef4-6b66-4739-8613-cc70c748a962@googlegroups.com: > > On Tuesday, 24 April 2018 07:18:46 UTC+1, > > DecadentLinux...@decadence.org wrote: > > > >> Screw the gap pad. > > > > not generally regarded as good engineering practice > > > > Nice job of making an out of context trim, jackass. > > IF you knew how to read, you would have noticed that it gets replaced > with a BETTER conducting thermal epoxy. > > Wake the fuck up and read. Casual glances at written works makes you a > piss poor participant. > > Making out of context posts based on your petty, casual glances at what > was actually written is even worse.Now there's a giant woosh
Reply by ●April 25, 20182018-04-25
tabbypurr@gmail.com wrote in news:45ff243a-d5c9-4cf7-a7b4-c27a89e9f790@googlegroups.com:> On Wednesday, 25 April 2018 01:01:34 UTC+1, > DecadentLinux...@decadence.org wrote: >> tabbypurr wrote in >> news:b354cef4-6b66-4739-8613-cc70c748a962@googlegroups.com: >> > On Tuesday, 24 April 2018 07:18:46 UTC+1, >> > DecadentLinux...@decadence.org wrote: >> > >> >> Screw the gap pad. >> > >> > not generally regarded as good engineering practice >> > >> >> Nice job of making an out of context trim, jackass. >> >> IF you knew how to read, you would have noticed that it gets >> replaced >> with a BETTER conducting thermal epoxy. >> >> Wake the fuck up and read. Casual glances at written works makes >> you a >> piss poor participant. >> >> Making out of context posts based on your petty, casual glances at >> what >> was actually written is even worse. > > Now there's a giant woosh >Woosh this, motherfucker... thermal epoxy conducts heat BETTER than your precious gap filler.
Reply by ●April 25, 20182018-04-25
On Wednesday, 25 April 2018 06:02:45 UTC+1, DecadentLinux...@decadence.org wrote:> tabbypurr wrote in > news:45ff243a-d5c9-4cf7-a7b4-c27a89e9f790@googlegroups.com: > > On Wednesday, 25 April 2018 01:01:34 UTC+1, > > DecadentLinux...@decadence.org wrote: > >> tabbypurr wrote in > >> news:b354cef4-6b66-4739-8613-cc70c748a962@googlegroups.com: > >> > On Tuesday, 24 April 2018 07:18:46 UTC+1, > >> > DecadentLinux...@decadence.org wrote:> >> >> Screw the gap pad. > >> > > >> > not generally regarded as good engineering practice > >> > > >> > >> Nice job of making an out of context trim, jackass. > >> > >> IF you knew how to read, you would have noticed that it gets > >> replaced > >> with a BETTER conducting thermal epoxy. > >> > >> Wake the fuck up and read. Casual glances at written works makes > >> you a > >> piss poor participant. > >> > >> Making out of context posts based on your petty, casual glances at > >> what > >> was actually written is even worse.> > Now there's a giant woosh> Woosh this, motherfucker... thermal epoxy conducts heat BETTER than > your precious gap filler.I see you've still completely failed to get that simple joke. No biggie. NT
Reply by ●April 26, 20182018-04-26
Phil Hobbs wrote:> The obvious approach is an aluminum-core circuit board, but I've never used one.I have used them several times, with excellent results, good direction.> 1. Can I get a 6- or 8-layer aluminum-core PCB?Great Scot, in my case only single-sided. Sounds like a super-custom thingy. IBM perhaps? They can do 70 layer ceramic PCBs: https://upload.wikimedia.org/wikipedia/commons/1/1f/Power5.jpg> 2. How much more do they cost?The ones abovementioned were negligible compared to a regular FR4. +50% or so in the quantity of 15, prototype-mode order and 10 days manufacturing. 11 bucks net a piece for the size of 88x110mm.> 3. Any other constraints?1. There's no point in drilling. ;-) 2. Your vocabulary will get marvelously enriched during the hand assembly of the prototype, don't even attempt it without a decent preheater. 3. You'll love them. Best regards, Piotr
Reply by ●April 26, 20182018-04-26
