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| Date: | Mon, 19 Dec 2016 22:21:35 +0000 |
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And for the love of Pete... preheat
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of David Hillman
Sent: Monday, December 19, 2016 2:15 PM
To: [log in to unmask]
Subject: Re: [TN] PTH component lead to copper etch "heat sink"
Hi Phil - oh, if I could only have an 90 mil board with 2 oz copper layers!
I routinely see pwb designs, primarily power supplies, which are 60 mils
- 120 mil with 2, 3 or 4 oz internal layers. As your detailed, soldering can be "an adventure" with these designs. A selective solder process is your friend as it has the thermal mass to permit adequate soldering of the PTH components. There are many of these types of designs that manual soldering is no longer a valid option (IMHO). You may have some luck with reducing the number of internal layer connections and or how the PTH is connected to the internal layer to make soldering slightly better. Good luck.
Dave Hillman
Rockwell Collins
[log in to unmask]
On Mon, Dec 19, 2016 at 12:34 PM, Nutting, Phil <[log in to unmask]>
wrote:
> Hi All,
>
> We have several designs in which we use the thru-hole pad and
> surrounding etch to act as a heat sink for device heat being
> transmitted via the component leads. Typically 2 ounce copper and
> often on 0.090" thick FR-4 boards. With the added copper thickness
> and larger pad area for better "heat sinking" we now introduce greater
> difficulty in getting a quality solder joint and don't get me started
> on the increased difficulty in removing a bad component.
>
> So my questions are:
> Is this a common practice?
> Does it really provide effective device heat sinking?
>
> Phil Nutting | HVP Development Engineer | Excelitas Technologies Corp
>
> Lab: +1 978.224.4332 | Office: +1 978.224.4152
> 35 Congress St, Salem, MA 01970 USA
> [log in to unmask]<mailto:[log in to unmask]>
> www.excelitas.com<http://www.excelitas.com/>
>
>
> [Excelitas R_emailsig]
>
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