Homebrew PCBs

Hi list,

Hello List,
Anyone has a idea how to produce a aluminium pcb over a virgin aluminum
board?
I'm looking a way to home brew a pcb to solder some power leds that are
very sensitivy to thermal dissipation.
By what I've seen, the companies applying some kind of metal deposit over a
virgin aluminium board, to permit soldering.
Thanks.
Roger.


[Non-text portions of this message have been removed]

Hi,

Have no idea if what you ask is possible. Have you considered using a common
FR4 copper PCB with common Al/Cu heat sinks bolted/screwed on the sides of
the led with some thermal paste? Much cheaper...

Usually, high power LED's came assembled in a heat dissipating base ready
for heat sinks

Nuno T.

> -----Original Message-----
> From: Homebrew_PCBs@yahoogroups.com 
> [mailto:Homebrew_PCBs@yahoogroups.com] On Behalf Of Rogerio F Cunha
> Sent: domingo, 7 de Outubro de 2012 14:44
> To: Homebrew_PCBs@yahoogroups.com
> Subject: [Homebrew_PCBs] Aluminium base pcb
> 
> Hi list,
> 
> Hello List,
> Anyone has a idea how to produce a aluminium pcb over a 
> virgin aluminum board?
> I'm looking a way to home brew a pcb to solder some power 
> leds that are very sensitivy to thermal dissipation.
> By what I've seen, the companies applying some kind of metal 
> deposit over a virgin aluminium board, to permit soldering.
> Thanks.
> Roger.
> 
> 
> [Non-text portions of this message have been removed]
> 
> 
> 
> ------------------------------------
> 
> Be sure to visit the group home and check for new Links, 
> Files, and Photos:
> http://groups.yahoo.com/group/Homebrew_PCBsYahoo! Groups Links
> 
> 
>

If you are concerned about thermal dissipation, use solid copper instead. It has better thermal conductivity than aluminum and you can solder to boot. But beware you are going to have to use high powered soldering iron to get it hot enough to solder onto it. you wanted a big heat sink. So soldering is going to be very hard. If you want to safely dissipate 300W, just as an example, you are going to need something with over 300W for your soldering iron.

If you really want to solder onto aluminum there are aluminum specific solder. These are alloys of aluminum and lead and require much higher temperature than regular solder. Don't think regular soldering iron gets hot enough to melt the aluminum solder. I've used it but with a acetylene torch. Regular propane torch is just hot enough. MAPP gas torch without oxygen is doable. The temperature will definitely exceed temperature profile of power device mounting.

I do know of another engineer who said his tech used a TIG welder to weld a heat sink to a power device. Power device is not something you use every day. 1000AMP with breakdown of 1000V kind of things.


--- In Homebrew_PCBs@yahoogroups.com, "Nuno T." <nuno-t@...> wrote:

>
> Hi,
> 
> Have no idea if what you ask is possible. Have you considered using a common
> FR4 copper PCB with common Al/Cu heat sinks bolted/screwed on the sides of
> the led with some thermal paste? Much cheaper...
> 
> Usually, high power LED's came assembled in a heat dissipating base ready
> for heat sinks
> 
> Nuno T.
> 
> > -----Original Message-----
> > From: Homebrew_PCBs@yahoogroups.com 
> > [mailto:Homebrew_PCBs@yahoogroups.com] On Behalf Of Rogerio F Cunha
> > Sent: domingo, 7 de Outubro de 2012 14:44
> > To: Homebrew_PCBs@yahoogroups.com
> > Subject: [Homebrew_PCBs] Aluminium base pcb
> > 
> > Hi list,
> > 
> > Hello List,
> > Anyone has a idea how to produce a aluminium pcb over a 
> > virgin aluminum board?
> > I'm looking a way to home brew a pcb to solder some power 
> > leds that are very sensitivy to thermal dissipation.
> > By what I've seen, the companies applying some kind of metal 
> > deposit over a virgin aluminium board, to permit soldering.
> > Thanks.
> > Roger.
> > 
> > 
> > [Non-text portions of this message have been removed]
> > 
> > 
> > 
> > ------------------------------------
> > 
> > Be sure to visit the group home and check for new Links, 
> > Files, and Photos:
> > http://groups.yahoo.com/group/Homebrew_PCBsYahoo! Groups Links
> > 
> > 
> >
>

I don't understand what you are trying to do but I do have experience
soldering aluminum.

I never use anything other than the flux that I normlly use for
soldering electrical connections to avoid tool contamination.

The iron you use needs to supply enough heat to get the aluminum above
the melting point of solder. Rub the iron with some force to abrade the
aluminum oxide layer on the work WHILE applying a little solder to the
work. Once you get it tinned with a little solder you can connect to it
normally.  Of course it does not hurt to clean up the aluminum with a
bit of scotch bright first, but the oxide layer forms fast.

It takes a little practice, I suggest a soda can for practice.



--- In Homebrew_PCBs@yahoogroups.com, Rogerio F Cunha
<rogerio.cunha@...> wrote:
>
> Hi list,
>
> Hello List,
> Anyone has a idea how to produce a aluminium pcb over a virgin
aluminum
> board?
> I'm looking a way to home brew a pcb to solder some power leds that
are
> very sensitivy to thermal dissipation.
> By what I've seen, the companies applying some kind of metal deposit
over a

> virgin aluminium board, to permit soldering.
> Thanks.
> Roger.
>
>
> [Non-text portions of this message have been removed]
>

The aluminium PCB is a kind of PCB where the aluminium takes place of
the FRF-4. I think it receives a thin insulation layer and a
conductive track over that.
You can see many examples searching on the Internet. These kind of PCB
is specially developed to solder high power leds.


2012/10/8, John <jferrell13@...>:

>
>
> I don't understand what you are trying to do but I do have experience
> soldering aluminum.
>
> I never use anything other than the flux that I normlly use for
> soldering electrical connections to avoid tool contamination.
>
> The iron you use needs to supply enough heat to get the aluminum above
> the melting point of solder. Rub the iron with some force to abrade the
> aluminum oxide layer on the work WHILE applying a little solder to the
> work. Once you get it tinned with a little solder you can connect to it
> normally.  Of course it does not hurt to clean up the aluminum with a
> bit of scotch bright first, but the oxide layer forms fast.
>
> It takes a little practice, I suggest a soda can for practice.
>
>
>
> --- In Homebrew_PCBs@yahoogroups.com, Rogerio F Cunha
> <rogerio.cunha@...> wrote:
>>
>> Hi list,
>>
>> Hello List,
>> Anyone has a idea how to produce a aluminium pcb over a virgin
> aluminum
>> board?
>> I'm looking a way to home brew a pcb to solder some power leds that
> are
>> very sensitivy to thermal dissipation.
>> By what I've seen, the companies applying some kind of metal deposit
> over a
>> virgin aluminium board, to permit soldering.
>> Thanks.
>> Roger.
>>
>>
>> [Non-text portions of this message have been removed]
>>
>
>
>
>

In article <k4uqjr+3jm9@...>,
   Shawn <smilingcat@...> wrote:
> If you are concerned about thermal dissipation, use solid copper
> instead. It has better thermal conductivity than aluminum and you can
> solder to boot. But beware you are going to have to use high powered
> soldering iron to get it hot enough to solder onto it. you wanted a big
> heat sink. So soldering is going to be very hard. If you want to safely
> dissipate 300W, just as an example, you are going to need something with
> over 300W for your soldering iron.

Seems to me you would solder to a smaller copper slug and then bolt that
to a larger heatsink in the normal way.

-- 
Stuart Winsor

Only plain text for emails
http://www.asciiribbon.org

Hey Guys

I did this before, use regular candle wax and a good soldering iron.
I used a 240w Weller gun.
thanks everybody.

Sebastian (K4BAC) 

--- In Homebrew_PCBs@yahoogroups.com, Rogerio F Cunha <rogerio.cunha@...> wrote:

>
> The aluminium PCB is a kind of PCB where the aluminium takes place of
> the FRF-4. I think it receives a thin insulation layer and a
> conductive track over that.
> You can see many examples searching on the Internet. These kind of PCB
> is specially developed to solder high power leds.
> 
> 
> 2012/10/8, John <jferrell13@...>:
> >
> >
> > I don't understand what you are trying to do but I do have experience
> > soldering aluminum.
> >
> > I never use anything other than the flux that I normlly use for
> > soldering electrical connections to avoid tool contamination.
> >
> > The iron you use needs to supply enough heat to get the aluminum above
> > the melting point of solder. Rub the iron with some force to abrade the
> > aluminum oxide layer on the work WHILE applying a little solder to the
> > work. Once you get it tinned with a little solder you can connect to it
> > normally.  Of course it does not hurt to clean up the aluminum with a
> > bit of scotch bright first, but the oxide layer forms fast.
> >
> > It takes a little practice, I suggest a soda can for practice.
> >
> >
> >
> > --- In Homebrew_PCBs@yahoogroups.com, Rogerio F Cunha
> > <rogerio.cunha@> wrote:
> >>
> >> Hi list,
> >>
> >> Hello List,
> >> Anyone has a idea how to produce a aluminium pcb over a virgin
> > aluminum
> >> board?
> >> I'm looking a way to home brew a pcb to solder some power leds that
> > are
> >> very sensitivy to thermal dissipation.
> >> By what I've seen, the companies applying some kind of metal deposit
> > over a
> >> virgin aluminium board, to permit soldering.
> >> Thanks.
> >> Roger.
> >>
> >>
> >> [Non-text portions of this message have been removed]
> >>
> >
> >
> >
> >
>

On Sun, Oct 7, 2012 at 9:43 AM, Rogerio F Cunha <rogerio.cunha@...>wrote:

> **
>
>
> Hi list,
>
> Hello List,
> Anyone has a idea how to produce a aluminium pcb over a virgin aluminum
> board?
> I'm looking a way to home brew a pcb to solder some power leds that are
> very sensitivy to thermal dissipation.
> By what I've seen, the companies applying some kind of metal deposit over a
> virgin aluminium board, to permit soldering.
>

MCPCB

Metal Core PCB.  http://goo.gl/GXctT

Not quite sure how the pros do it.

 If I was trying to fake it, I'd etch my led PCB on the thinnest copper
clad I could find, with the largest copper lands I could get away with
 Then I'd bond the pcb to an alum back plate with some good thermal paste.

-carl


[Non-text portions of this message have been removed]

Ah, took a little while to figure out what you were talking about.

There's some confusion because almost all the finished boards are nickel plated too. It's a layer of copper on aluminum. I believe the insulator is probably kapton or a fiberglass layer impregnated with something "thermal". If it were just a super thick layer of anodizing the developer might strip it out.

Cut edges are a problem for etching/developing because you don't want exposed aluminum reacting with the etchant. I'm guessing it comes with a mask on the back or it's clear anodized.

As for soldering I'd just use the same technique for all SMT boards with ground planes, preheat the BACK to 150C, and then either manually solder the front or hot air the parts down with paste.

Of course if you are doing whole boards at once, the toaster oven method comes to mind.
I'm always doing exotic and multi layer boards at home, so have a little experience. Used to do it professionally, but can't afford the x-ray machine and reflow equipment.
I've made my own temperature controlled back side heater and use a modified craft hot air tool for home use.

--- In Homebrew_PCBs@yahoogroups.com, "H. Carl Ott" <hcarlott@...> wrote:

>
> On Sun, Oct 7, 2012 at 9:43 AM, Rogerio F Cunha <rogerio.cunha@...>wrote:
> 
> > **
> >
> >
> > Hi list,
> >
> > Hello List,
> > Anyone has a idea how to produce a aluminium pcb over a virgin aluminum
> > board?
> > I'm looking a way to home brew a pcb to solder some power leds that are
> > very sensitivy to thermal dissipation.
> > By what I've seen, the companies applying some kind of metal deposit over a
> > virgin aluminium board, to permit soldering.
> >
> 
> MCPCB
> 
> Metal Core PCB.  http://goo.gl/GXctT
> 
> Not quite sure how the pros do it.
> 
>  If I was trying to fake it, I'd etch my led PCB on the thinnest copper
> clad I could find, with the largest copper lands I could get away with
>  Then I'd bond the pcb to an alum back plate with some good thermal paste.
> 
> -carl
> 
> 
> [Non-text portions of this message have been removed]
>

Dennis, I really did some confusion to explain what I want to do.
I wish to thanks Carl to bring a better definition about this technology
(MCPCB).
Roger


2012/10/9 Dennis <nojoeco@...>

> **
>
>
> Ah, took a little while to figure out what you were talking about.
>
> There's some confusion because almost all the finished boards are nickel
> plated too. It's a layer of copper on aluminum. I believe the insulator is
> probably kapton or a fiberglass layer impregnated with something "thermal".
> If it were just a super thick layer of anodizing the developer might strip
> it out.
>
> Cut edges are a problem for etching/developing because you don't want
> exposed aluminum reacting with the etchant. I'm guessing it comes with a
> mask on the back or it's clear anodized.
>
> As for soldering I'd just use the same technique for all SMT boards with
> ground planes, preheat the BACK to 150C, and then either manually solder
> the front or hot air the parts down with paste.
>
> Of course if you are doing whole boards at once, the toaster oven method
> comes to mind.
> I'm always doing exotic and multi layer boards at home, so have a little
> experience. Used to do it professionally, but can't afford the x-ray
> machine and reflow equipment.
> I've made my own temperature controlled back side heater and use a
> modified craft hot air tool for home use.
>
> --- In Homebrew_PCBs@yahoogroups.com, "H. Carl Ott" <hcarlott@...> wrote:
> >
> > On Sun, Oct 7, 2012 at 9:43 AM, Rogerio F Cunha <rogerio.cunha@
> ...>wrote:
>
> >
> > > **
> > >
> > >
> > > Hi list,
> > >
> > > Hello List,
> > > Anyone has a idea how to produce a aluminium pcb over a virgin aluminum
> > > board?
> > > I'm looking a way to home brew a pcb to solder some power leds that are
> > > very sensitivy to thermal dissipation.
> > > By what I've seen, the companies applying some kind of metal deposit
> over a
> > > virgin aluminium board, to permit soldering.
> > >
> >
> > MCPCB
> >
> > Metal Core PCB. http://goo.gl/GXctT
> >
> > Not quite sure how the pros do it.
> >
> > If I was trying to fake it, I'd etch my led PCB on the thinnest copper
> > clad I could find, with the largest copper lands I could get away with
> > Then I'd bond the pcb to an alum back plate with some good thermal paste.
> >
> > -carl
> >
> >
> > [Non-text portions of this message have been removed]
> >
>
>  
>


[Non-text portions of this message have been removed]

Hello Roger,

I can see that most users got confused about your question.

I think Roger want to do is simply to make PCBs with aluminum. Am I right Roger?

Instead as the usual copper base, the PCB surface is aluminum. Period.

And although someone did comment about better heat properties of copper instead of aluminum, almost any LED manufacturer in the world is using aluminum instead of copper as the PCB thermal substrate.

Regards.



--- In Homebrew_PCBs@yahoogroups.com, Rogerio F Cunha <rogerio.cunha@...> wrote:

>
> Hi list,
> 
> Hello List,
> Anyone has a idea how to produce a aluminium pcb over a virgin aluminum
> board?
> I'm looking a way to home brew a pcb to solder some power leds that are
> very sensitivy to thermal dissipation.
> By what I've seen, the companies applying some kind of metal deposit over a
> virgin aluminium board, to permit soldering.
> Thanks.
> Roger.
> 
> 
> [Non-text portions of this message have been removed]
>

Just to make sure I'm not confused(it happens).

The original poster is wanting to make their own LED "modules".
In other words when someone usually orders a 1watt or larger led they actually get a module of led on an aluminum "board".

Due to needing a custom solution the op is wanting to make their own?
It's absolutely correct that almost all commercial solutions are on aluminum, but it isn't required as seen by the datasheets.
But it's clearly the cheapest and easiest to machine/cut/etc. and is probably the way to go.

Since this all started I looked at the led units I've got laying around. They are all indeed aluminum modules. But all that they really are upon closer examination is a wafer thin standard pcb bonded to an aluminum backing. Usually with an epoxy solder mask that appears to obscure the board completely, leaving only solder pads visible.
Some of these units have cutouts in the pcb under the led pad itself so that the led has direct contact with the aluminum backing.

Indium does have solder for aluminum, and aluminum to copper applications, but it is corrosive to standard electronics so other solutions are usually used. 

If there are boards that are aluminum over an insulator on an aluminum backing, I clearly have to learn more about those. I might have to fix some someday soon!

Good luck and keep experimenting!


--- In Homebrew_PCBs@yahoogroups.com, "jcarlosmor" <jcarlosmor@...> wrote:

>
> 
> Hello Roger,
> 
> I can see that most users got confused about your question.
> 
> I think Roger want to do is simply to make PCBs with aluminum. Am I right Roger?
> 
> Instead as the usual copper base, the PCB surface is aluminum. Period.
> 
> And although someone did comment about better heat properties of copper instead of aluminum, almost any LED manufacturer in the world is using aluminum instead of copper as the PCB thermal substrate.
> 
> Regards.
> 
> 
> 
> --- In Homebrew_PCBs@yahoogroups.com, Rogerio F Cunha <rogerio.cunha@> wrote:
> >
> > Hi list,
> > 
> > Hello List,
> > Anyone has a idea how to produce a aluminium pcb over a virgin aluminum
> > board?
> > I'm looking a way to home brew a pcb to solder some power leds that are
> > very sensitivy to thermal dissipation.
> > By what I've seen, the companies applying some kind of metal deposit over a
> > virgin aluminium board, to permit soldering.
> > Thanks.
> > Roger.
> > 
> > 
> > [Non-text portions of this message have been removed]
> >
>

Odd to reply to myself, but.
Phew... I'm not confused.

After actually reading the referred to websites that make these boards, it's clear they are exactly like the ones I have.

Yep it's copper top(standard weights too), fiberglass or kapton insulator layer, aluminum base. Some board houses use a "magic" process to etch the aluminum so there's no need to drill through the insulator layer to raw aluminum.

Standard smt processes used for soldering.

If I had to make one from scratch I'd get adhesive backed kapton tape, apply that to an aluminum sheet, and layer that with adhesive backed copper tape. Mask the aluminum and etch like a regular board. Another way would be to use raw flex board and use thermal epoxy to bond that to aluminum.


--- In Homebrew_PCBs@yahoogroups.com, "Dennis" <nojoeco@...> wrote:

>
> Just to make sure I'm not confused(it happens).
> 
> The original poster is wanting to make their own LED "modules".
> In other words when someone usually orders a 1watt or larger led they actually get a module of led on an aluminum "board".
> 
> Due to needing a custom solution the op is wanting to make their own?
> It's absolutely correct that almost all commercial solutions are on aluminum, but it isn't required as seen by the datasheets.
> But it's clearly the cheapest and easiest to machine/cut/etc. and is probably the way to go.
> 
> Since this all started I looked at the led units I've got laying around. They are all indeed aluminum modules. But all that they really are upon closer examination is a wafer thin standard pcb bonded to an aluminum backing. Usually with an epoxy solder mask that appears to obscure the board completely, leaving only solder pads visible.
> Some of these units have cutouts in the pcb under the led pad itself so that the led has direct contact with the aluminum backing.
> 
> Indium does have solder for aluminum, and aluminum to copper applications, but it is corrosive to standard electronics so other solutions are usually used. 
> 
> If there are boards that are aluminum over an insulator on an aluminum backing, I clearly have to learn more about those. I might have to fix some someday soon!
> 
> Good luck and keep experimenting!
> 
> 
> --- In Homebrew_PCBs@yahoogroups.com, "jcarlosmor" <jcarlosmor@> wrote:
> >
> > 
> > Hello Roger,
> > 
> > I can see that most users got confused about your question.
> > 
> > I think Roger want to do is simply to make PCBs with aluminum. Am I right Roger?
> > 
> > Instead as the usual copper base, the PCB surface is aluminum. Period.
> > 
> > And although someone did comment about better heat properties of copper instead of aluminum, almost any LED manufacturer in the world is using aluminum instead of copper as the PCB thermal substrate.
> > 
> > Regards.
> > 
> > 
> > 
> > --- In Homebrew_PCBs@yahoogroups.com, Rogerio F Cunha <rogerio.cunha@> wrote:
> > >
> > > Hi list,
> > > 
> > > Hello List,
> > > Anyone has a idea how to produce a aluminium pcb over a virgin aluminum
> > > board?
> > > I'm looking a way to home brew a pcb to solder some power leds that are
> > > very sensitivy to thermal dissipation.
> > > By what I've seen, the companies applying some kind of metal deposit over a
> > > virgin aluminium board, to permit soldering.
> > > Thanks.
> > > Roger.
> > > 
> > > 
> > > [Non-text portions of this message have been removed]
> > >
> >
>

This is the stuff I talked about:

"MCPCB's offer one of the most effective methods of thermal management for
lighting designs utilising LEDs.

MCPCB's comprise of 3 main components;

1 - Copper conductor layer where the LEDs are mounted.

2 - Insulator; a very thin thermally conductive but electrically isolated
laminate material  (NOT FR4)

3 - Metal cladding - a sheet of aluminium or copper substrate which
dissipates the heat produced by the LEDs.

These MCPCB's also allow easy interface to a heatsink or the outer housing
of the customers application to aid cooling further."


After all collaboration on this thread, I believe it's hard to home brew.

"Nuno T." gave me an idea that looks feasible and might give a good result.

"Have no idea if what you ask is possible. Have you considered using a
common
FR4 copper PCB with common Al/Cu heat sinks bolted/screwed on the sides of
the led with some thermal paste? Much cheaper..."

Thanks,




2012/10/12 Dennis <nojoeco@...>

> **
>
>
> Odd to reply to myself, but.
> Phew... I'm not confused.
>
> After actually reading the referred to websites that make these boards,
> it's clear they are exactly like the ones I have.
>
> Yep it's copper top(standard weights too), fiberglass or kapton insulator
> layer, aluminum base. Some board houses use a "magic" process to etch the
> aluminum so there's no need to drill through the insulator layer to raw
> aluminum.
>
> Standard smt processes used for soldering.
>
> If I had to make one from scratch I'd get adhesive backed kapton tape,
> apply that to an aluminum sheet, and layer that with adhesive backed copper
> tape. Mask the aluminum and etch like a regular board. Another way would be
> to use raw flex board and use thermal epoxy to bond that to aluminum.
>
>
> --- In Homebrew_PCBs@yahoogroups.com, "Dennis" <nojoeco@...> wrote:
> >
> > Just to make sure I'm not confused(it happens).
> >
> > The original poster is wanting to make their own LED "modules".
> > In other words when someone usually orders a 1watt or larger led they
> actually get a module of led on an aluminum "board".
> >
> > Due to needing a custom solution the op is wanting to make their own?
> > It's absolutely correct that almost all commercial solutions are on
> aluminum, but it isn't required as seen by the datasheets.
> > But it's clearly the cheapest and easiest to machine/cut/etc. and is
> probably the way to go.
> >
> > Since this all started I looked at the led units I've got laying around.
> They are all indeed aluminum modules. But all that they really are upon
> closer examination is a wafer thin standard pcb bonded to an aluminum
> backing. Usually with an epoxy solder mask that appears to obscure the
> board completely, leaving only solder pads visible.
> > Some of these units have cutouts in the pcb under the led pad itself so
> that the led has direct contact with the aluminum backing.
> >
> > Indium does have solder for aluminum, and aluminum to copper
> applications, but it is corrosive to standard electronics so other
> solutions are usually used.
> >
> > If there are boards that are aluminum over an insulator on an aluminum
> backing, I clearly have to learn more about those. I might have to fix some
> someday soon!
> >
> > Good luck and keep experimenting!
> >
> >
> > --- In Homebrew_PCBs@yahoogroups.com, "jcarlosmor" <jcarlosmor@> wrote:
> > >
> > >
> > > Hello Roger,
> > >
> > > I can see that most users got confused about your question.
> > >
> > > I think Roger want to do is simply to make PCBs with aluminum. Am I
> right Roger?
> > >
> > > Instead as the usual copper base, the PCB surface is aluminum. Period.
> > >
> > > And although someone did comment about better heat properties of
> copper instead of aluminum, almost any LED manufacturer in the world is
> using aluminum instead of copper as the PCB thermal substrate.
> > >
> > > Regards.
> > >
> > >
> > >
> > > --- In Homebrew_PCBs@yahoogroups.com, Rogerio F Cunha <rogerio.cunha@>
> wrote:
> > > >
> > > > Hi list,
> > > >
> > > > Hello List,
> > > > Anyone has a idea how to produce a aluminium pcb over a virgin
> aluminum
> > > > board?
> > > > I'm looking a way to home brew a pcb to solder some power leds that
> are
> > > > very sensitivy to thermal dissipation.
> > > > By what I've seen, the companies applying some kind of metal deposit
> over a
> > > > virgin aluminium board, to permit soldering.
> > > > Thanks.
> > > > Roger.
> > > >
> > > >
> > > > [Non-text portions of this message have been removed]
> > > >
> > >
> >
>
>  
>


[Non-text portions of this message have been removed]

This looks like the perfect application for Dupont Pyralux sheets:
http://www2.dupont.com/Pyralux/en_US/products/laminate/index.html

Etch the copper layer of the flexible circuit board, use a craft cutter like CirCut to cut out the LED areas which need to touch the aluminium, then stick the flex onto the aluminium sheets.

Which leads to the next "bright idea" - Can a standard laser printer print directly onto Pyralux, at least the very thin highly flexible variety? If so, homebrew flexible circuits just got easier than rigid PCBs, no toner transfer needed, just fuse toner in a laminator and etch!

Regards
--


--- In Homebrew_PCBs@yahoogroups.com, Rogerio F Cunha <rogerio.cunha@...> wrote:

>
> This is the stuff I talked about:
> 
> "MCPCB's offer one of the most effective methods of thermal management for
> lighting designs utilising LEDs.
> 
> MCPCB's comprise of 3 main components;
> 
> 1 - Copper conductor layer where the LEDs are mounted.
> 
> 2 - Insulator; a very thin thermally conductive but electrically isolated
> laminate material  (NOT FR4)
> 
> 3 - Metal cladding - a sheet of aluminium or copper substrate which
> dissipates the heat produced by the LEDs.
> 
> These MCPCB's also allow easy interface to a heatsink or the outer housing
> of the customers application to aid cooling further."
> 
> 
> After all collaboration on this thread, I believe it's hard to home brew.
> 
> "Nuno T." gave me an idea that looks feasible and might give a good result.
> 
> "Have no idea if what you ask is possible. Have you considered using a
> common
> FR4 copper PCB with common Al/Cu heat sinks bolted/screwed on the sides of
> the led with some thermal paste? Much cheaper..."
> 
> Thanks,
> 
> 
> 
>