Layer Numbers and Stacking Stripes

[popest]

Hello,

I have one question. I have found this video from Altium https://www.youtube.com/watch?v=sEpJfq3OvUU about layer numbers and stacking stripes. There you can also download pcb library which contains prepared numbers for signal and power plane layers. In the past, I have never used this because local vendors here in CZ which I use do not need it.

I would like to know your opinion about what is the best approach. I saw that someone use mirrored layer numbers. e.g. 4 layer PCB. 1 and 2 numbers are normal and 3, 4 are mirrored. I am little confused because in this video no number is mirrored only last one on bottom layer has set property - flipped on layer. What is the correct approach and do you know why he set flipped on layer for the bottom number?

Thank you for your answers.

[robertferanec]

I do not use it anymore. Many times there is no space on my PCBs and we have never had any problems with swapped layers. However it really may depend on what PCB manufacturer you are using (I have seen PCBs with swapped layers (layers which were not correctly ordered) - mistake during PCB production - and based on visibility of these numbers you could see that there is a mistake in layer ordering).

Why he mirrored text on the bottom layer? I guess one of the reasons is to avoid confusion (there is also other text on the bottom layer and it may look weird or confusing if one of the texts is mirrored the other way that others). Other internal layers do not have any text, so it doesn't really matter if they are mirrored or not.

Why half of them may be mirrored? I would mirror them, because it may be easier to see them - basically you see the first half from the top correctly and nicely and when you look from the bottom, then you see the second half correctly mirrored. That may be easier than trying to see all the numbers from top through whole PCB - the last one may not be well visible (depends on stackup).

That is just my guessing

[Paul van Avesaath]

Hi,

i make them manually, just a box with spaced numbers in between.. fill up the internal planes.. and your done.. the mirrored numbers are indeed for looking at it from the back..

when you get your PCB and hold it up to the light then you can read e.g. 1-2 then flip the board and read 3-4...

it is not really nescesarry anymore, but like robert said, i have seen a couple of layers mixed up at manufacturing.. (one of the reasons I add the layer name in the gerber / ODB++ outside of the board)

with more than 8 layers it becomes pretty much unreadable with the internal planes..