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Thread
2011-02-01 by Steve Hodge
I've been checking out the various heat sinks for D2PAK devices and confess to being confused as to how they are mounted. I'd also like some recommendations, if anybody has any, for ones that are the easiest to use. I need to be able to hand solder things. Thanks, Steve __________ Information from ESET Smart Security, version of virus signature database 5838 (20110201) __________ The message was checked by ESET Smart Security. http://www.eset.com
2011-02-02 by tim gilbert
Steve, For such packages, I usually just expand the copper area around the device on both the top and bottom layers. I then interconnect them with lots of large vias. Effectively building a heat sink into the board. Tim Gilbert JEM Innovation Inc. www.jeminnovation.com www.pdksolutions.com
----- Original Message -----
From: Steve Hodge
To: AVR-Chat@yahoogroups.com
Sent: Tuesday, February 01, 2011 2:45 PM
Subject: [AVR-Chat] d2pak heat sink
I've been checking out the various heat sinks for D2PAK devices and confess
to being confused as to how they are mounted. I'd also like some
recommendations, if anybody has any, for ones that are the easiest to use.
I need to be able to hand solder things.
Thanks, Steve
__________ Information from ESET Smart Security, version of virus signature
database 5838 (20110201) __________
The message was checked by ESET Smart Security.
http://www.eset.com
[Non-text portions of this message have been removed]2011-02-02 by Steve Hodge
Thanks, Tim. Since the tab is ground, I assume you just connect the upper one to a regular ground plane on the bottom? I came across an App Note (#994) on the International Rectifier website that made measurements of the thermal resistance of various SMD packages, using 3 different "pcb heat sink" techniques. Although the bottom of their test board was "fully metalized" there is no mention of explicitly connecting it to the test patterns on the top with vias. I suppose some heat conducts through the fiberglass but your technique should give significantly lower thermal resistances than they measured because the thermal conductivity of copper is 10000 times that of fiberglass. Steve
From: AVR-Chat@yahoogroups.com [mailto:AVR-Chat@yahoogroups.com] On Behalf Of tim gilbert Sent: Tuesday, February 01, 2011 4:33 PM To: AVR-Chat@yahoogroups.com Subject: Re: [AVR-Chat] d2pak heat sink Steve, For such packages, I usually just expand the copper area around the device on both the top and bottom layers. I then interconnect them with lots of large vias. Effectively building a heat sink into the board. Tim Gilbert JEM Innovation Inc. www.jeminnovation.com www.pdksolutions.com ----- Original Message ----- From: Steve Hodge To: AVR-Chat@yahoogroups.com <mailto:AVR-Chat%40yahoogroups.com> Sent: Tuesday, February 01, 2011 2:45 PM Subject: [AVR-Chat] d2pak heat sink I've been checking out the various heat sinks for D2PAK devices and confess to being confused as to how they are mounted. I'd also like some recommendations, if anybody has any, for ones that are the easiest to use. I need to be able to hand solder things. Thanks, Steve __________ Information from ESET Smart Security, version of virus signature database 5838 (20110201) __________ The message was checked by ESET Smart Security. http://www.eset.com [Non-text portions of this message have been removed] __________ Information from ESET Smart Security, version of virus signature database 5838 (20110201) __________ The message was checked by ESET Smart Security. http://www.eset.com __________ Information from ESET Smart Security, version of virus signature database 5838 (20110201) __________ The message was checked by ESET Smart Security. http://www.eset.com [Non-text portions of this message have been removed]
2011-02-02 by tim gilbert
Steve, I've attached a print of the corner of a board we did this way. Note that the holes are really big, 0.062". I did this to allow for air flow but have no idea what difference it makes. Maybe smaller holes are better? Someday I should try and model this in our 3D CAD. Tim Gilbert JEM Innovation Inc. www.jeminnovation.com www.pdksolutions.com
----- Original Message -----
From: Steve Hodge
To: AVR-Chat@yahoogroups.com
Sent: Tuesday, February 01, 2011 7:27 PM
Subject: RE: [AVR-Chat] d2pak heat sink
Thanks, Tim. Since the tab is ground, I assume you just connect the upper
one to a regular ground plane on the bottom?
I came across an App Note (#994) on the International Rectifier website that
made measurements of the thermal resistance of various SMD packages, using 3
different "pcb heat sink" techniques. Although the bottom of their test
board was "fully metalized" there is no mention of explicitly connecting it
to the test patterns on the top with vias. I suppose some heat conducts
through the fiberglass but your technique should give significantly lower
thermal resistances than they measured because the thermal conductivity of
copper is 10000 times that of fiberglass.
Steve
From: AVR-Chat@yahoogroups.com [mailto:AVR-Chat@yahoogroups.com] On Behalf
Of tim gilbert
Sent: Tuesday, February 01, 2011 4:33 PM
To: AVR-Chat@yahoogroups.com
Subject: Re: [AVR-Chat] d2pak heat sink
Steve,
For such packages, I usually just expand the copper area around the device
on both the top and bottom layers. I then interconnect them with lots of
large vias. Effectively building a heat sink into the board.
Tim Gilbert
JEM Innovation Inc.
www.jeminnovation.com
www.pdksolutions.com
----- Original Message -----
From: Steve Hodge
To: AVR-Chat@yahoogroups.com <mailto:AVR-Chat%40yahoogroups.com>
Sent: Tuesday, February 01, 2011 2:45 PM
Subject: [AVR-Chat] d2pak heat sink
I've been checking out the various heat sinks for D2PAK devices and confess
to being confused as to how they are mounted. I'd also like some
recommendations, if anybody has any, for ones that are the easiest to use.
I need to be able to hand solder things.
Thanks, Steve
__________ Information from ESET Smart Security, version of virus signature
database 5838 (20110201) __________
The message was checked by ESET Smart Security.
http://www.eset.com
[Non-text portions of this message have been removed]
__________ Information from ESET Smart Security, version of virus signature
database 5838 (20110201) __________
The message was checked by ESET Smart Security.
http://www.eset.com
__________ Information from ESET Smart Security, version of virus signature
database 5838 (20110201) __________
The message was checked by ESET Smart Security.
http://www.eset.com
[Non-text portions of this message have been removed]
[Non-text portions of this message have been removed]2011-02-02 by Steve Hodge
Tim, I can't find the attachment.
From: AVR-Chat@yahoogroups.com [mailto:AVR-Chat@yahoogroups.com] On Behalf Of tim gilbert Sent: Tuesday, February 01, 2011 7:21 PM To: AVR-Chat@yahoogroups.com Subject: Re: [AVR-Chat] d2pak heat sink Steve, I've attached a print of the corner of a board we did this way. Note that the holes are really big, 0.062". I did this to allow for air flow but have no idea what difference it makes. Maybe smaller holes are better? Someday I should try and model this in our 3D CAD. Tim Gilbert JEM Innovation Inc. www.jeminnovation.com www.pdksolutions.com ----- Original Message ----- From: Steve Hodge To: AVR-Chat@yahoogroups.com <mailto:AVR-Chat%40yahoogroups.com> Sent: Tuesday, February 01, 2011 7:27 PM Subject: RE: [AVR-Chat] d2pak heat sink Thanks, Tim. Since the tab is ground, I assume you just connect the upper one to a regular ground plane on the bottom? I came across an App Note (#994) on the International Rectifier website that made measurements of the thermal resistance of various SMD packages, using 3 different "pcb heat sink" techniques. Although the bottom of their test board was "fully metalized" there is no mention of explicitly connecting it to the test patterns on the top with vias. I suppose some heat conducts through the fiberglass but your technique should give significantly lower thermal resistances than they measured because the thermal conductivity of copper is 10000 times that of fiberglass. Steve From: AVR-Chat@yahoogroups.com <mailto:AVR-Chat%40yahoogroups.com> [mailto:AVR-Chat@yahoogroups.com <mailto:AVR-Chat%40yahoogroups.com> ] On Behalf Of tim gilbert Sent: Tuesday, February 01, 2011 4:33 PM To: AVR-Chat@yahoogroups.com <mailto:AVR-Chat%40yahoogroups.com> Subject: Re: [AVR-Chat] d2pak heat sink Steve, For such packages, I usually just expand the copper area around the device on both the top and bottom layers. I then interconnect them with lots of large vias. Effectively building a heat sink into the board. Tim Gilbert JEM Innovation Inc. www.jeminnovation.com www.pdksolutions.com ----- Original Message ----- From: Steve Hodge To: AVR-Chat@yahoogroups.com <mailto:AVR-Chat%40yahoogroups.com> <mailto:AVR-Chat%40yahoogroups.com> Sent: Tuesday, February 01, 2011 2:45 PM Subject: [AVR-Chat] d2pak heat sink I've been checking out the various heat sinks for D2PAK devices and confess to being confused as to how they are mounted. I'd also like some recommendations, if anybody has any, for ones that are the easiest to use. I need to be able to hand solder things. Thanks, Steve __________ Information from ESET Smart Security, version of virus signature database 5838 (20110201) __________ The message was checked by ESET Smart Security. http://www.eset.com [Non-text portions of this message have been removed] __________ Information from ESET Smart Security, version of virus signature database 5838 (20110201) __________ The message was checked by ESET Smart Security. http://www.eset.com __________ Information from ESET Smart Security, version of virus signature database 5838 (20110201) __________ The message was checked by ESET Smart Security. http://www.eset.com [Non-text portions of this message have been removed] [Non-text portions of this message have been removed] __________ Information from ESET Smart Security, version of virus signature database 5838 (20110201) __________ The message was checked by ESET Smart Security. http://www.eset.com __________ Information from ESET Smart Security, version of virus signature database 5838 (20110201) __________ The message was checked by ESET Smart Security. http://www.eset.com [Non-text portions of this message have been removed]
2011-02-02 by tim gilbert
Steve, I can't attach or upload a pdf so I've added an image to a photo album named "JEM Innovation". Tim
----- Original Message -----
From: Steve Hodge
To: AVR-Chat@yahoogroups.com
Sent: Tuesday, February 01, 2011 9:10 PM
Subject: RE: [AVR-Chat] d2pak heat sink
Tim, I can't find the attachment.
From: AVR-Chat@yahoogroups.com [mailto:AVR-Chat@yahoogroups.com] On Behalf
Of tim gilbert
Sent: Tuesday, February 01, 2011 7:21 PM
To: AVR-Chat@yahoogroups.com
Subject: Re: [AVR-Chat] d2pak heat sink
Steve,
I've attached a print of the corner of a board we did this way. Note that
the holes are really big, 0.062". I did this to allow for air flow but have
no idea what difference it makes. Maybe smaller holes are better? Someday I
should try and model this in our 3D CAD.
Tim Gilbert
JEM Innovation Inc.
www.jeminnovation.com
www.pdksolutions.com
----- Original Message -----
From: Steve Hodge
To: AVR-Chat@yahoogroups.com <mailto:AVR-Chat%40yahoogroups.com>
Sent: Tuesday, February 01, 2011 7:27 PM
Subject: RE: [AVR-Chat] d2pak heat sink
Thanks, Tim. Since the tab is ground, I assume you just connect the upper
one to a regular ground plane on the bottom?
I came across an App Note (#994) on the International Rectifier website that
made measurements of the thermal resistance of various SMD packages, using 3
different "pcb heat sink" techniques. Although the bottom of their test
board was "fully metalized" there is no mention of explicitly connecting it
to the test patterns on the top with vias. I suppose some heat conducts
through the fiberglass but your technique should give significantly lower
thermal resistances than they measured because the thermal conductivity of
copper is 10000 times that of fiberglass.
Steve
From: AVR-Chat@yahoogroups.com <mailto:AVR-Chat%40yahoogroups.com>
[mailto:AVR-Chat@yahoogroups.com <mailto:AVR-Chat%40yahoogroups.com> ] On
Behalf
Of tim gilbert
Sent: Tuesday, February 01, 2011 4:33 PM
To: AVR-Chat@yahoogroups.com <mailto:AVR-Chat%40yahoogroups.com>
Subject: Re: [AVR-Chat] d2pak heat sink
Steve,
For such packages, I usually just expand the copper area around the device
on both the top and bottom layers. I then interconnect them with lots of
large vias. Effectively building a heat sink into the board.
Tim Gilbert
JEM Innovation Inc.
www.jeminnovation.com
www.pdksolutions.com
----- Original Message -----
From: Steve Hodge
To: AVR-Chat@yahoogroups.com <mailto:AVR-Chat%40yahoogroups.com>
<mailto:AVR-Chat%40yahoogroups.com>
Sent: Tuesday, February 01, 2011 2:45 PM
Subject: [AVR-Chat] d2pak heat sink
I've been checking out the various heat sinks for D2PAK devices and confess
to being confused as to how they are mounted. I'd also like some
recommendations, if anybody has any, for ones that are the easiest to use.
I need to be able to hand solder things.
Thanks, Steve
__________ Information from ESET Smart Security, version of virus signature
database 5838 (20110201) __________
The message was checked by ESET Smart Security.
http://www.eset.com
[Non-text portions of this message have been removed]
__________ Information from ESET Smart Security, version of virus signature
database 5838 (20110201) __________
The message was checked by ESET Smart Security.
http://www.eset.com
__________ Information from ESET Smart Security, version of virus signature
database 5838 (20110201) __________
The message was checked by ESET Smart Security.
http://www.eset.com
[Non-text portions of this message have been removed]
[Non-text portions of this message have been removed]
__________ Information from ESET Smart Security, version of virus signature
database 5838 (20110201) __________
The message was checked by ESET Smart Security.
http://www.eset.com
__________ Information from ESET Smart Security, version of virus signature
database 5838 (20110201) __________
The message was checked by ESET Smart Security.
http://www.eset.com
[Non-text portions of this message have been removed]
[Non-text portions of this message have been removed]2011-02-02 by Steve Hodge
Got it. Is that for a D2PAK? Is the rectangle with thermals there just because it makes it easier to first solder the tab to it and then solder the case to the main expanse of heat sink area? You're right, those are big vias.
From: AVR-Chat@yahoogroups.com [mailto:AVR-Chat@yahoogroups.com] On Behalf Of tim gilbert Sent: Wednesday, February 02, 2011 8:11 AM To: AVR-Chat@yahoogroups.com Subject: Re: [AVR-Chat] d2pak heat sink Steve, I can't attach or upload a pdf so I've added an image to a photo album named "JEM Innovation". Tim ----- Original Message ----- From: Steve Hodge To: AVR-Chat@yahoogroups.com <mailto:AVR-Chat%40yahoogroups.com> Sent: Tuesday, February 01, 2011 9:10 PM Subject: RE: [AVR-Chat] d2pak heat sink Tim, I can't find the attachment. From: AVR-Chat@yahoogroups.com <mailto:AVR-Chat%40yahoogroups.com> [mailto:AVR-Chat@yahoogroups.com <mailto:AVR-Chat%40yahoogroups.com> ] On Behalf Of tim gilbert Sent: Tuesday, February 01, 2011 7:21 PM To: AVR-Chat@yahoogroups.com <mailto:AVR-Chat%40yahoogroups.com> Subject: Re: [AVR-Chat] d2pak heat sink Steve, I've attached a print of the corner of a board we did this way. Note that the holes are really big, 0.062". I did this to allow for air flow but have no idea what difference it makes. Maybe smaller holes are better? Someday I should try and model this in our 3D CAD. Tim Gilbert JEM Innovation Inc. www.jeminnovation.com www.pdksolutions.com ----- Original Message ----- From: Steve Hodge To: AVR-Chat@yahoogroups.com <mailto:AVR-Chat%40yahoogroups.com> <mailto:AVR-Chat%40yahoogroups.com> Sent: Tuesday, February 01, 2011 7:27 PM Subject: RE: [AVR-Chat] d2pak heat sink Thanks, Tim. Since the tab is ground, I assume you just connect the upper one to a regular ground plane on the bottom? I came across an App Note (#994) on the International Rectifier website that made measurements of the thermal resistance of various SMD packages, using 3 different "pcb heat sink" techniques. Although the bottom of their test board was "fully metalized" there is no mention of explicitly connecting it to the test patterns on the top with vias. I suppose some heat conducts through the fiberglass but your technique should give significantly lower thermal resistances than they measured because the thermal conductivity of copper is 10000 times that of fiberglass. Steve From: AVR-Chat@yahoogroups.com <mailto:AVR-Chat%40yahoogroups.com> <mailto:AVR-Chat%40yahoogroups.com> [mailto:AVR-Chat@yahoogroups.com <mailto:AVR-Chat%40yahoogroups.com> <mailto:AVR-Chat%40yahoogroups.com> ] On Behalf Of tim gilbert Sent: Tuesday, February 01, 2011 4:33 PM To: AVR-Chat@yahoogroups.com <mailto:AVR-Chat%40yahoogroups.com> <mailto:AVR-Chat%40yahoogroups.com> Subject: Re: [AVR-Chat] d2pak heat sink Steve, For such packages, I usually just expand the copper area around the device on both the top and bottom layers. I then interconnect them with lots of large vias. Effectively building a heat sink into the board. Tim Gilbert JEM Innovation Inc. www.jeminnovation.com www.pdksolutions.com ----- Original Message ----- From: Steve Hodge To: AVR-Chat@yahoogroups.com <mailto:AVR-Chat%40yahoogroups.com> <mailto:AVR-Chat%40yahoogroups.com> <mailto:AVR-Chat%40yahoogroups.com> Sent: Tuesday, February 01, 2011 2:45 PM Subject: [AVR-Chat] d2pak heat sink I've been checking out the various heat sinks for D2PAK devices and confess to being confused as to how they are mounted. I'd also like some recommendations, if anybody has any, for ones that are the easiest to use. I need to be able to hand solder things. Thanks, Steve __________ Information from ESET Smart Security, version of virus signature database 5838 (20110201) __________ The message was checked by ESET Smart Security. http://www.eset.com [Non-text portions of this message have been removed] __________ Information from ESET Smart Security, version of virus signature database 5838 (20110201) __________ The message was checked by ESET Smart Security. http://www.eset.com __________ Information from ESET Smart Security, version of virus signature database 5838 (20110201) __________ The message was checked by ESET Smart Security. http://www.eset.com [Non-text portions of this message have been removed] [Non-text portions of this message have been removed] __________ Information from ESET Smart Security, version of virus signature database 5838 (20110201) __________ The message was checked by ESET Smart Security. http://www.eset.com __________ Information from ESET Smart Security, version of virus signature database 5838 (20110201) __________ The message was checked by ESET Smart Security. http://www.eset.com [Non-text portions of this message have been removed] [Non-text portions of this message have been removed] __________ Information from ESET Smart Security, version of virus signature database 5840 (20110202) __________ The message was checked by ESET Smart Security. http://www.eset.com __________ Information from ESET Smart Security, version of virus signature database 5840 (20110202) __________ The message was checked by ESET Smart Security. http://www.eset.com [Non-text portions of this message have been removed]
2011-02-02 by tim gilbert
Steve, It's not the D2PAK but an SOT-223. Same idea though. Tim
----- Original Message -----
From: Steve Hodge
To: AVR-Chat@yahoogroups.com
Sent: Wednesday, February 02, 2011 9:36 AM
Subject: RE: [AVR-Chat] d2pak heat sink
Got it. Is that for a D2PAK? Is the rectangle with thermals there just
because it makes it easier to first solder the tab to it and then solder the
case to the main expanse of heat sink area? You're right, those are big
vias.
From: AVR-Chat@yahoogroups.com [mailto:AVR-Chat@yahoogroups.com] On Behalf
Of tim gilbert
Sent: Wednesday, February 02, 2011 8:11 AM
To: AVR-Chat@yahoogroups.com
Subject: Re: [AVR-Chat] d2pak heat sink
Steve,
I can't attach or upload a pdf so I've added an image to a photo album named
"JEM Innovation".
Tim
----- Original Message -----
From: Steve Hodge
To: AVR-Chat@yahoogroups.com <mailto:AVR-Chat%40yahoogroups.com>
Sent: Tuesday, February 01, 2011 9:10 PM
Subject: RE: [AVR-Chat] d2pak heat sink
Tim, I can't find the attachment.
From: AVR-Chat@yahoogroups.com <mailto:AVR-Chat%40yahoogroups.com>
[mailto:AVR-Chat@yahoogroups.com <mailto:AVR-Chat%40yahoogroups.com> ] On
Behalf
Of tim gilbert
Sent: Tuesday, February 01, 2011 7:21 PM
To: AVR-Chat@yahoogroups.com <mailto:AVR-Chat%40yahoogroups.com>
Subject: Re: [AVR-Chat] d2pak heat sink
Steve,
I've attached a print of the corner of a board we did this way. Note that
the holes are really big, 0.062". I did this to allow for air flow but have
no idea what difference it makes. Maybe smaller holes are better? Someday I
should try and model this in our 3D CAD.
Tim Gilbert
JEM Innovation Inc.
www.jeminnovation.com
www.pdksolutions.com
----- Original Message -----
From: Steve Hodge
To: AVR-Chat@yahoogroups.com <mailto:AVR-Chat%40yahoogroups.com>
<mailto:AVR-Chat%40yahoogroups.com>
Sent: Tuesday, February 01, 2011 7:27 PM
Subject: RE: [AVR-Chat] d2pak heat sink
Thanks, Tim. Since the tab is ground, I assume you just connect the upper
one to a regular ground plane on the bottom?
I came across an App Note (#994) on the International Rectifier website that
made measurements of the thermal resistance of various SMD packages, using 3
different "pcb heat sink" techniques. Although the bottom of their test
board was "fully metalized" there is no mention of explicitly connecting it
to the test patterns on the top with vias. I suppose some heat conducts
through the fiberglass but your technique should give significantly lower
thermal resistances than they measured because the thermal conductivity of
copper is 10000 times that of fiberglass.
Steve
From: AVR-Chat@yahoogroups.com <mailto:AVR-Chat%40yahoogroups.com>
<mailto:AVR-Chat%40yahoogroups.com>
[mailto:AVR-Chat@yahoogroups.com <mailto:AVR-Chat%40yahoogroups.com>
<mailto:AVR-Chat%40yahoogroups.com> ] On
Behalf
Of tim gilbert
Sent: Tuesday, February 01, 2011 4:33 PM
To: AVR-Chat@yahoogroups.com <mailto:AVR-Chat%40yahoogroups.com>
<mailto:AVR-Chat%40yahoogroups.com>
Subject: Re: [AVR-Chat] d2pak heat sink
Steve,
For such packages, I usually just expand the copper area around the device
on both the top and bottom layers. I then interconnect them with lots of
large vias. Effectively building a heat sink into the board.
Tim Gilbert
JEM Innovation Inc.
www.jeminnovation.com
www.pdksolutions.com
----- Original Message -----
From: Steve Hodge
To: AVR-Chat@yahoogroups.com <mailto:AVR-Chat%40yahoogroups.com>
<mailto:AVR-Chat%40yahoogroups.com>
<mailto:AVR-Chat%40yahoogroups.com>
Sent: Tuesday, February 01, 2011 2:45 PM
Subject: [AVR-Chat] d2pak heat sink
I've been checking out the various heat sinks for D2PAK devices and confess
to being confused as to how they are mounted. I'd also like some
recommendations, if anybody has any, for ones that are the easiest to use.
I need to be able to hand solder things.
Thanks, Steve
__________ Information from ESET Smart Security, version of virus signature
database 5838 (20110201) __________
The message was checked by ESET Smart Security.
http://www.eset.com
[Non-text portions of this message have been removed]
__________ Information from ESET Smart Security, version of virus signature
database 5838 (20110201) __________
The message was checked by ESET Smart Security.
http://www.eset.com
__________ Information from ESET Smart Security, version of virus signature
database 5838 (20110201) __________
The message was checked by ESET Smart Security.
http://www.eset.com
[Non-text portions of this message have been removed]
[Non-text portions of this message have been removed]
__________ Information from ESET Smart Security, version of virus signature
database 5838 (20110201) __________
The message was checked by ESET Smart Security.
http://www.eset.com
__________ Information from ESET Smart Security, version of virus signature
database 5838 (20110201) __________
The message was checked by ESET Smart Security.
http://www.eset.com
[Non-text portions of this message have been removed]
[Non-text portions of this message have been removed]
__________ Information from ESET Smart Security, version of virus signature
database 5840 (20110202) __________
The message was checked by ESET Smart Security.
http://www.eset.com
__________ Information from ESET Smart Security, version of virus signature
database 5840 (20110202) __________
The message was checked by ESET Smart Security.
http://www.eset.com
[Non-text portions of this message have been removed]
[Non-text portions of this message have been removed]2011-02-03 by Dave McLaughlin
Hi Tim I just had a quick look. As you have the pad for the tab and then thermal reliefs out to the plane, I am not sure you are going to get as good a heat transfer as you would expect. The whole idea of thermal reliefs is to enable good soldering by reducing the amount of heat lost out to the plane so the opposite effect will take place with heat from the device. Would you not be better to put the thermal plane on the opposite side and use a lot of via's in the pad of the tab itself. Similar to what you do with those IC's with a thermal pad on the underside of the component? I have done this very thing with power supply IC's where I place the thermal pad between the pads for the pins, and then lay down as many small vias as I can. I then lay down a thermal plane on the opposite side of the PCB which is connected bya the vias. This has worked very well for me in the past. Dave... --- Very funny Scotty, now beam down my clothes!!! ---
From: AVR-Chat@yahoogroups.com [mailto:AVR-Chat@yahoogroups.com] On Behalf Of tim gilbert Sent: 02 February 2011 23:11 To: AVR-Chat@yahoogroups.com Subject: Re: [AVR-Chat] d2pak heat sink Steve, I can't attach or upload a pdf so I've added an image to a photo album named "JEM Innovation". Tim [Non-text portions of this message have been removed]