Searching \ for '[EE] the future heatsinks will be made from plasti' in subject line. ()
Make payments with PayPal - it's fast, free and secure! Help us get a faster server
FAQ page: www.piclist.com/techref/index.htm?key=future+heatsinks
Search entire site for: 'the future heatsinks will be made from plasti'.

Exact match. Not showing close matches.
PICList Thread
'[EE] the future heatsinks will be made from plasti'
2008\04\21@132026 by Vasile Surducan

face picon face
www2.electronicproducts.com/Conductive_plastics_supplant_metal_in_heat_sinks-article-hlrr02_jun2008-html.aspx

2008\04\21@202837 by William \Chops\ Westfield

face picon face

On Apr 21, 2008, at 10:20 AM, Vasile Surducan wrote:
> http://www2.electronicproducts.com/
> Conductive_plastics_supplant_metal_in_heat_sinks-article-
> hlrr02_jun2008-html.aspx


I've seen heatsinks made of plastic before.  I wasn't sure whether  
they had any useful properties as heatsinks, or whether they had been  
put on there to make the product look more "sophisticated."

The press release says:

> In typical electronic power and airflow environments, the plastics  
> provide equivalent heat transfer to aluminum parts. Specifications  
> include thermal conductivity of 20 W/m-K

I don't see how both sentences can be true, since Al thermal  
conductivity is about 220 W/m-K  (however the website of the company  
claims conductivities up to 100W/m-K, which is better.)

Personally, I'm holding out for diamond...

BillW

2008\04\21@220852 by Stephen R Phillips

picon face



--- On Mon, 4/21/08, William "Chops" Westfield <spam_OUTwestfwTakeThisOuTspammac.com> wrote:

{Quote hidden}

Just finding one in the rough would be profitable!

It seems the manufacturer is geared more for people who are doing custom molding of parts than people looking for heat sinks.  This is an EXTREMLY poor choice because the majority of people who produce plastic parts do not  really do any design, that is left to the customer.  So the end result is they aren't giving enough expertise to the people who need it (IE the person who needs the custom part).

Most companies DON'T want to be experts at making plastic parts, it's very expensive, and requires a lot of detailed knowledge over a years worth of training with trial and error.  In essence they have to hire someone to get parts they need made.  This is expensive and limits the market severely for the materials they are offering. Off the shelf parts offer small to mid range customers more options.  I don't think there is a need for yet another product that requires gross amounts of technical knowledge to just mold and then in addition to that more technical knowledge to handle the thermal issues.

You might be able to get a part made using there materials for roughly a minimum of 250K, if you have someone how knows solid works or another 3d modeling system and has experience with molding parts as well as thermal design.  For that kind of money aluminum parts are likely cheaper.  I'm not sure what the life of the molds would be either. Simple molds are about 10K to 25K complicated ones start at 100K and get very pricey.  Making a few million parts a year this is peanuts but if you need 100K that is where things aren't so good.

Nice idea but ... better and more useful information or at the very least, fabricated parts would be better.

Cut able electrically insulating sheets with vertical fins for example would make it VERY useful to medium and small businesses. As is only large to very large companies can make use of it. I have an application I could use THAT in at the very least, a little machining for prototyping or initial production is a lot cheaper that way.

Stephen


     ____________________________________________________________________________________
Be a better friend, newshound, and
know-it-all with Yahoo! Mobile.  Try it now.  mobile.yahoo.com/;_ylt=Ahu06i62sR8HDtDypao8Wcj9tAcJ

2008\04\22@070552 by Spehro Pefhany

picon face
At 10:08 PM 4/21/2008, you wrote:

>It seems the manufacturer is geared more for people who are doing
>custom molding of parts than people looking for heat sinks.  This is
>an EXTREMLY poor choice because the majority of people who produce
>plastic parts do not  really do any design, that is left to the
>customer.  So the end result is they aren't giving enough expertise
>to the people who need it (IE the person who needs the custom part).

You think? I don't see any molding parameters there other than
shrinkage .. nor some specific part design parameters such
as heat deflection temperature. I could calculate the cycle time from
the diffusivity and heat capacity etc., but
only if I know the melt temperature. No melt index number (an
indication of how gummy it is at melt temperature).

In contrast, they give fairly complete info for the part designer
(modulus, impact strength etc.) according
to ISO and ASTM methods, but no information on performance at
different temperatures-- rather important for
a heat sink, especially at elevated temperatures.

>st companies DON'T want to be experts at making plastic parts, it's
>very expensive, and requires a lot of detailed knowledge over a
>years worth of training with trial and error.  In essence they have
>to hire someone to get parts they need made.  This is expensive and
>limits the market severely for the materials they are offering. Off
>the shelf parts offer small to mid range customers more options.  I
>don't think there is a need for yet another product that requires
>gross amounts of technical knowledge to just mold and then in
>addition to that more technical knowledge to handle the thermal issues.

Well, it's just another plastic part of many required in a typical
product, but with the addition of
thermal performance requirements. If you're doing FE anyway..

>You might be able to get a part made using there materials for
>roughly a minimum of 250K,

You're quite high with this estimate. Designing moulded parts is not
really that hard-- any competent
mechanical engineer can thoroughly learn the basics in a year-- and
just reading a couple good books
($150 each) can get you most of the way there, particularly if you
avoid fancy stuff like living
hinges and perhaps snaps (although the design of snaps isn't that
hard either). The mold designer
has to to know a bit more (and some different things) than the molded
part designer. She or he
is paid as part of making the mold.

>if you have someone how knows solid works or another 3d modeling
>system and has experience with molding parts as well as thermal
>design.  For that kind of money aluminum parts are likely
>cheaper.  I'm not sure what the life of the molds would be either.
>Simple molds are about 10K to 25K complicated ones start at 100K and
>get very pricey.  Making a few million parts a year this is peanuts
>but if you need 100K that is where things aren't so good.

Life is not a matter of complexity, but more the materials used (and
size). A prototype mold made from 7075 (SPI Class
105) will have a rather short life. Use pre-hardened steel with
nitrided inserts and >1,000,000 shots
(SPI Class 101) is not so hard, but it costs much more to make such a
tool. At 100K pcs. a 25-50K mold is 25-50
cents a part. It's not chump change, but look at in terms of percent
of the cost of a house.. well below 10% probably,
so lots of small businesses and most medium size businesses can raise
that kind of money. There are cheaper
molds, and schemes where you buy just the inserts, but realistically
a quality stand-alone mold is worth
some tens of thousands of dollars for a part you can hold in one
hand. Bigger parts as for cars etc. get
pricey (half a million or more).

{Quote hidden}

Machining is extremely expensive. You could also pay to have an extrusion die
made and machine something that is more-or-less the right shape, just as is
done with aluminum profiles.

Another interesting trend is injection molding metals directly (or using
certain indirect methods). This can allow extremely thin-walled and finely
detailed parts to be created for high volume consumer electronics such as
cell phones and other portable high performance devices.

Consider magnesium-- it's only 10% denser than their Polyamide 4,6
and something
like 5 times stronger, so you likely need a lot less of it. Also, it's
an abundant element and not made from petroleum or natural gas, unlike most
polymers. Unfortunately, this is still an extremely expensive process in
every way, so unless you're RIM or Apple it might not be practical.

Best regards,

Spehro Pefhany --"it's the network..."            "The Journey is the reward"
.....speffKILLspamspam@spam@interlog.com             Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog  Info for designers:  http://www.speff.com



2008\04\22@075149 by Peter Todd

flavicon
face
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

On Tue, Apr 22, 2008 at 07:07:44AM -0400, Spehro Pefhany wrote:
{Quote hidden}

FWIW I noticed that Cool Polymers, the guys making the thermally
conductive plastic, also has a line of injection mouldable metal alloys
that they claim can be moulded on standard injection molding equipment
and moulds:

http://www.coolpolymers.com/XyloyM950.asp

- --
http://petertodd.org 'peter'[:-1]@petertodd.org
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.6 (GNU/Linux)

iD8DBQFIDc9l3bMhDbI9xWQRAupwAJ9dDcd+FX21kASqmKU0AEKpgE4b9QCffqZK
l0flAAtg7Z0Ybg4+zbPeaZk=
=cgdM
-----END PGP SIGNATURE-----

More... (looser matching)
- Last day of these posts
- In 2008 , 2009 only
- Today
- New search...