# What part of stack-up planning takes you the longest?

**URL:** <https://sierraconnect.protoexpress.com/t/what-part-of-stack-up-planning-takes-you-the-longest/4280>\
**Category:** Tools & Calculators\
**Tags:** stack-up\
**Created:** [July 21, 2026, 4:44pm UTC](https://sierraconnect.protoexpress.com/t/what-part-of-stack-up-planning-takes-you-the-longest/4280 "2026-07-21T16:44:59Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![atar.mittal](https://sea2.discourse-cdn.com/sierraconnect/user_avatar/sierraconnect.protoexpress.com/atar.mittal/32/49_2.png) [@atar.mittal](https://sierraconnect.protoexpress.com/u/atar.mittal)\
**Post date:** [July 21, 2026, 4:44pm UTC](https://sierraconnect.protoexpress.com/t/what-part-of-stack-up-planning-takes-you-the-longest/4280/1 "2026-07-21T16:44:59Z")

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**Sierra’s take:** From the manufacturing side, we often see the most back-and-forth happen when the stack-up is developed too late in the design process. Material availability, finished thickness, impedance requirements, copper weights, dielectric thicknesses, via structures, and the fab house’s capabilities all affect one another.

One thing we always recommend: **involve your fabricator before you start routing** , especially for controlled impedance, HDI, high-speed, or unusual material requirements. A stack-up that looks perfect on paper may need adjustments to actually be manufacturable and changing it after routing can create a lot more work.

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**Author:** ![atar.mittal](https://sea2.discourse-cdn.com/sierraconnect/user_avatar/sierraconnect.protoexpress.com/atar.mittal/32/49_2.png) [@atar.mittal](https://sierraconnect.protoexpress.com/u/atar.mittal)\
**Post date:** [July 21, 2026, 4:46pm UTC](https://sierraconnect.protoexpress.com/t/what-part-of-stack-up-planning-takes-you-the-longest/4280/2 "2026-07-21T16:46:19Z")

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Sierra has had a strong stack-up tool for many years and we update it on a regular basis. You should absolutely use it. It’s free.

[https://www.protoexpress.com/tools/pcb-stackup-designer/](https://www.protoexpress.com/tools/pcb-stackup-designer/)

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**Author:** ![lucy.sierracircuits](https://sea2.discourse-cdn.com/sierraconnect/user_avatar/sierraconnect.protoexpress.com/lucy.sierracircuits/32/8_2.png) [@lucy.sierracircuits](https://sierraconnect.protoexpress.com/u/lucy.sierracircuits)\
**Post date:** [July 21, 2026, 9:09pm UTC](https://sierraconnect.protoexpress.com/t/what-part-of-stack-up-planning-takes-you-the-longest/4280/3 "2026-07-21T21:09:07Z")

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**Let’s hear it from the designers here, shall we?** Is it choosing materials, determining layer count, impedance planning, via architecture, or something else that eats up most of your time?

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**Author:** ![lucy.sierracircuits](https://sea2.discourse-cdn.com/sierraconnect/user_avatar/sierraconnect.protoexpress.com/lucy.sierracircuits/32/8_2.png) [@lucy.sierracircuits](https://sierraconnect.protoexpress.com/u/lucy.sierracircuits)\
**Post date:** [July 21, 2026, 10:45pm UTC](https://sierraconnect.protoexpress.com/t/what-part-of-stack-up-planning-takes-you-the-longest/4280/4 "2026-07-21T22:45:27Z")

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And I forgot to share our [Stack-Up Design Guide](https://www.protoexpress.com/pcb-design-guides/pcb-stack-up-design-guide/?utm_source=sierraconnect&utm_medium=display&utm_campaign=feed%2B2026).