Phil.

Sounds like you are making high output led lighting or similar


Explain to the customer that the same efficient heatsink that stops his devices overheating Is having the same affect in your soldering irons. Also explain that pre heating is normal - example is wave soldering....has the Guy ever manufactured anything? 

Phil Bavaro <[log in to unmask]> wrote:

>I have a process where a metal backed PWA is being put on a hot plate in
>order to preheat the assembly high enough (140 C) so that a soldering
>iron can be used to solder (2-5 seconds) hand installed parts as well as
>to touch up any reflow defects.
>
>One customer has raised questions relative to the hot plate temperature
>overstressing the devices due to the extended time necessary to solder
>all the devices.   Subsequently all the Storage and Operating
>temperatures for the components needed to be presented.
>
>Across all of the devices, Storage Temperature maximum is either 150 C
>or 200 C.
>
>The Operating temperature rating for most of the devices is below 140 C
>(70, 125, 150).
>
>One can see how there might be some concern incorrectly focused on the
>assembly soldering temperatures violating this parameter.
>
>I know that soldering requires temperatures which exceed the operating
>and storage temperature rating ranges for our components, but how do I
>explain this to a customer who is asking such questions about the
>assembly soldering process.
>
>Certainly I can show the typical reflow curves listed by the SMT device
>manufacturer's, but since this application is post reflow hand solder,
>the manufacturer's don't have recommended hand soldering profiles to
>show the customer.  And certainly the preheated cycles are not reflected
>in a device curves.
>
>Any comments are welcome.
>
>
>Phil
>
>
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