# Trace under the passive components is allowed? is any IPC standard specify this point

**URL:** <https://sierraconnect.protoexpress.com/t/trace-under-the-passive-components-is-allowed-is-any-ipc-standard-specify-this-point/3710>\
**Category:** Design and Layout\
**Tags:** high-speed, ipc-class-3\
**Created:** [November 21, 2025, 3:29pm UTC](https://sierraconnect.protoexpress.com/t/trace-under-the-passive-components-is-allowed-is-any-ipc-standard-specify-this-point/3710 "2025-11-21T15:29:07Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![kabaleeswaran.kr](https://avatars.discourse-cdn.com/v4/letter/k/74df32/32.png) [@kabaleeswaran.kr](https://sierraconnect.protoexpress.com/u/kabaleeswaran.kr)\
**Post date:** [November 21, 2025, 3:29pm UTC](https://sierraconnect.protoexpress.com/t/trace-under-the-passive-components-is-allowed-is-any-ipc-standard-specify-this-point/3710/1 "2025-11-21T15:29:07Z")

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Hi Team,

I reviewed the layout; the product will be followed as IPC -class 3 standard. I found some traces are routed under the passive components. In general, I will avoid routing under the passive components like resistor and capacitor. (0603,0805,1206). but better deep understand the concept, can any say, Which IPC standard it will refer? or it is standard thumb rule.? I referred IPC-2221B, IPC-2222 I could not find any related documents.

 ![image](https://global.discourse-cdn.com/sierraconnect/original/1X/7179ab02121392ad9e27aec74f51b4992ac27f24.png)

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<div class="post-metadata">

**Author:** ![timothy.phillips](https://avatars.discourse-cdn.com/v4/letter/t/d78d45/32.png) [@timothy.phillips](https://sierraconnect.protoexpress.com/u/timothy.phillips)\
**Post date:** [November 21, 2025, 8:08pm UTC](https://sierraconnect.protoexpress.com/t/trace-under-the-passive-components-is-allowed-is-any-ipc-standard-specify-this-point/3710/2 "2025-11-21T20:08:13Z")

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I have not read where IPC has any recommendations on this method. I have seen copper under flush body components and it generally does not cause issues. Keep in mind that combined copper, mask, and silkscreen thickness under flush mounted components can cause mechanical or cleaning issues. Flux or other contamination can also occur and that can cause latent failures.

Personally I prefer to avoid copper in those areas.