The Most Common 2-Layer PCB Design Mistakes and How To Avoid Them

[@allanknox8216]

Misleading title. "Add more layers" is not fixing a 2 layer. Also ignores cost and delivery benefits. I'd like to see some real "2 layer fixes"

[@onesimpleneed]

Yep. Been doing this 36 years and get all sorts of work on reducing cost by reducing layer counts. Good designers first place everything correctly, then run their power and ground and critical traces and then everything else. I can do on two layers what other people need 4 and even 6 layers to do.

[@AlbertRei3424]

​@@onesimpleneeddo you know about return path?

[@rewq7041]

Thanks for the informative sharing, Peterson. When first looking at the topic, I think that the content will be some techniques about 2-layer PCB routing, but it is not. I agree that moving to 4-layer PCB is the general solution to many problems we encounter in 2-layer PCB layout, but in many low cost applications, this approach will not be considered due to cost and lead time issues. Even in some industrial grade or medical grade open frame power supplies, single layer or 2-layer PCB stackup is used, and they meet the class B EMI standard with margin. I am interested at these designs and the grounding techniques, like the co-planar signal track design with proper ground gridding, in 2-layer PCB applications.

[@Zachariah-Peterson]

I understand but the video was meant to be about some instances where 4 layer might be better due to the speed/noise problems faced in some systems or when modifying the 2-layer to have ground fill is an option, especially when there are a lot of digital components. In many instances 2 layer is fine if you design it appropriately, or you just might have to accept more noise as long as you don't fail EMI. For 2 layer the solution is usually coplanar ground fill but that solution may not work when you get to more advanced designs like much higher speed/higher frequencies. If you want a video specifically on 2-layer grounding I can get it into our queue.

[@Karthik_Selvam]

Hi Zach it's really useful. Also I looked out your article on the pcb design magazine. I love it sir. Thanks for providing good information 👍😊

[@Graham_Wideman]

2:00 Talks about the problem of crosstalk between parallel traces and possible radiated emissions. Zach first suggests orthogonal routing to prevent this, but doesn't explain why that would help either problem. It seems to me that the several signals still have to get from component A to component B, and to do so have to run parallel to each other, whether using random routing or ortho routing. In other videos on this channel, the recommendation is to space traces farther apart if they need to run parallel. To gain enough space to do so might entail putting some of the parallel traces on the other side of the board (ie: contradicting ortho routing). The other recommendation Zach makes is to go to a 4-layer board. Of course that always helps everything 🙂except cost, but specifically in this case how does it help reduce crosstalk between these parallel traces? I guess part of it is in shielding top traces from bottom traces. Also, the ground planes will attract the electric field lines from the individual traces, so that they impinge less on neighboring parallel traces. It also provides a better-defined and closer transient return current path, resulting in less magnetic emission impinging on the neighboring parallel traces. But still trace spacing will be an important contributor.

[@adrianmoldovan2793]

What a great and informative video. Lerned a lot from this. Great work! Congratulations!

[@AltiumAcademy]

Thanks so much!

[@r4yguzman190]

tutorials on PSpice simulations for beginners would be good.

[@fouzifouz3412]

hello sir ...im a beginner and i just want to know a thing .... how can we move different elements throw different layers without causing problems ..thank you

[@Zachariah-Peterson]

I'm not sure what you mean by "move different elements through different layers," are you referring to routing in multiple layers?

[@user-tl2yf8vy4v]

Good afternoon Can you tell me if the intersection of polygons of different names is allowed? Example: Layer 2 is analog ground, and layer 3 is digital ground?

[@Zachariah-Peterson]

What you are describing is the usage of two polygons with different nets on different layers. The system will always allow you to do this. If you have two polygons with different nets on the same layer, then the polygons will pour around each other. You can manage the pour order in the Polygon Manager dialog, this will allow you to choose which of the intersecting polygons gets cleared out when being poured.

[@shubhamsamal6712]

Sir How to send board design to review and receive comment on it

[@AltiumAcademy]

You can send it to Zach on LinkedIn here: www.linkedin.com/in/zachariah-peterson/

[@bitstobytes08]

@@AltiumAcademy Thankyou sir

[@bitstobytes08]

Sir. can you suggset some books for pcb designing that includes all the factors for designing pcb like an expert

[@Zachariah-Peterson]

Unfortunately there have not been some good new books prepared on this in a long time. But I can give you some direction to help you get started: Printed Circuits Handbook, by Clyde Coombs BGA Breakouts and Routing, by Charles Pfiel High Speed Digital Design, by Howard Johnson and Martin Graham

[@bitstobytes08]

Thank you sir for refering three books @@Zachariah-Peterson

[@salh2665]

❤❤❤شكرا التوم ❤❤❤

[@rfrisbee1]

There might be some milage for a whole series of videos like this one. I.e. "N layer PCB fixes" videos which each suggest the fix being to go to a N+2 layer PCB. 😉

[@AltiumAcademy]

Great suggestion!

[@Zachariah-Peterson]

Haha! What about N-2 layer fixes? Like layer consolidation under a BGA, which is something I had to do recently.

[@rfrisbee1]

@@Zachariah-Peterson That would be interesting to see and certainly much more challenging than increasing layer count.

[@jorditribo94]

The most common 2 layer PCB mistake is to make a 2 layer PCB.

[@AltiumAcademy]

😂😂😂😂😂

[@adriftfoolish1]

tldr; don't use 2-layer boards

[@Zachariah-Peterson]

I've shown examples on the channel of 2 layer boards I created, 2 layer boards are fine for a lot of things.