# Soldering the external LEDs especially PWR LED

**URL:** <https://discourse.myriadrf.org/t/soldering-the-external-leds-especially-pwr-led/1122>\
**Category:** LimeSDR\
**Created:** [16 April 2017 23:12 UTC](https://discourse.myriadrf.org/t/soldering-the-external-leds-especially-pwr-led/1122 "2017-04-16T23:12:26Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![sdr\_user](https://avatars.discourse-cdn.com/v4/letter/s/ac8455/32.png) [@sdr\_user](https://discourse.myriadrf.org/u/sdr_user)\
**Post date:** [16 April 2017 23:12 UTC](https://discourse.myriadrf.org/t/soldering-the-external-leds-especially-pwr-led/1122/1 "2017-04-16T23:12:26Z")

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Hi LimeSDR team,

is there a reason for the LimeSDR-USB PWR LED cathode pad, which is directly connected to ground, not having a thermal pad? It is really somewhat difficult to solder.

Best regards,  
Mike

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**Author:** ![Ancer](https://avatars.discourse-cdn.com/v4/letter/a/278dde/32.png) [@Ancer](https://discourse.myriadrf.org/u/Ancer)\
**Post date:** [16 April 2017 23:40 UTC](https://discourse.myriadrf.org/t/soldering-the-external-leds-especially-pwr-led/1122/2 "2017-04-16T23:40:09Z")

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You dont need thermal pad for the led unless you running 100 watts led flashlight.

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**Author:** ![sdr\_user](https://avatars.discourse-cdn.com/v4/letter/s/ac8455/32.png) [@sdr\_user](https://discourse.myriadrf.org/u/sdr_user)\
**Post date:** [17 April 2017 17:25 UTC](https://discourse.myriadrf.org/t/soldering-the-external-leds-especially-pwr-led/1122/3 "2017-04-17T17:25:03Z")

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Hi,  
obviously, we do not have the same understanding, what a thermal pad is. I am talking about the difficulty to solder a ground pad which is fully connected to the copper ground plane.

[https://en.wikipedia.org/wiki/Thermal\_relief](https://en.wikipedia.org/wiki/Thermal_relief)

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**Author:** ![mzs](https://yyz2.discourse-cdn.com/flex034/user_avatar/discourse.myriadrf.org/mzs/32/2678_2.png) [@mzs](https://discourse.myriadrf.org/u/mzs)\
**Post date:** [17 April 2017 21:16 UTC](https://discourse.myriadrf.org/t/soldering-the-external-leds-especially-pwr-led/1122/4 "2017-04-17T21:16:44Z")

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“Thermal pad” can also mean something else.

> **[Thermal Management Materials](https://www.henkel-adhesives.com/us/en/products/thermal-management-materials.html)**
>
> Developer and manufacturer of market-leading BERGQUIST® brand thermal management solutions.

  

> **[Thermally conductive pad](https://en.wikipedia.org/wiki/Thermally_conductive_pad)**
>
> In computing and electronics, thermal pads (also called thermally conductive pad or thermal interface pad) are pre-formed squares or rectangles of solid material (often paraffin wax or silicone based) commonly found on the underside of heatsinks to aid the conduction of heat away from the component being cooled (such as a CPU or another chip) and into the heatsink (usually made from aluminium or copper). Thermal pads and thermal compound are used to fill air gaps caused by imperfectly flat or smo...