My PCB fabricator is having trouble achieving the same impedance control used for the i.mx6 SD reference design stackup -
Layer1 = 1/2 oz to 1 oz
Layer2 = 1 oz
Layer3 = 1/2 oz
Layer4 = 1 oz
Layer5 = 1 oz
Layer6 = 1/2 oz
Layer7 = 1 oz
Layer8 = 1/2 oz to 1 oz
Impedance control Single
50R Layer1/Layer8 = 4.7 mil
50R Layer3/Layer6 = 4.5 mil
Impedance Control Differential
90R Layer1/Layer2/Layer3/Layer4 = 5.3/3.7 mil
100R Layer1/Layer8 = 3.7/5.3 mil
100R Layer3/Layer6 = 3.8/5.2 mil
Does anyone have PCB fabrication details (dielectric thickness etc) using the parameters above.
Thanks
Doug.
Hi Jorge.
Did this ever come to a conclusion? I need the same information, as I am about to start layout of an iMX6 design, and the gerber notes, the word document, and that spreadsheet, all conflict with each other.
Can you tell us please, which is correct?
Best regards,
Mark.
Hi Jorge,
Thank you for the information.
I still have some doubts.
In the gerber files the differential track width/spacing/width's are -
90R = 5.3/3.7/5.3
100R = 3.7/5.3/3.7 & 3.8/5.2/3.8
In the spreadsheet you sent the differential track width/spacing/width's are -
90R = 5.3/9/5.3
100R = 3.7/9/3.7 & 3.8/9/3.8
Also in the spreadsheet the internal layer copper thicknesses are all the same (1.3mils). The gerber file fabrication notes have different copper thicknesses for the internal layers.
I may be reading this wrongly but I still don't think this spreadsheet matches the gerber fabrication notes or differential tracks.
Thanks again for your help.
Doug.
Sorry, slight correction to the impedance layers-
Layer1 = 1/2 oz to 1 oz
Layer2 = 1 oz
Layer3 = 1/2 oz
Layer4 = 1 oz
Layer5 = 1 oz
Layer6 = 1/2 oz
Layer7 = 1 oz
Layer8 = 1/2 oz to 1 oz
Impedance control Single
50R Layer1/Layer8 = 4.7 mil
50R Layer3/Layer6 = 4.5 mil
Impedance Control Differential
90R Layer1/Layer8 = 5.3/3.7 mil
100R Layer1/Layer8 = 3.7/5.3 mil
100R Layer3/Layer6 = 3.8/5.2 mil
Thank you Jorge.
I am just concerned that the stack up table (dielectric etc) uses different copper weights than those in the first part of the document and also on the gerbers -
Your attached table =
3/8 oz copper
1/2 oz copper
1/2 oz copper
1/2 oz copper
1/2 oz copper
1/2 oz copper
1/2 oz copper
3/8 oz copper
Gerbers =
Layer1 = 1/2 oz to 1 oz
Layer2 = 1 oz
Layer3 = 1/2 oz
Layer4 = 1 oz
Layer5 = 1 oz
Layer6 = 1/2 oz
Layer7 = 1 oz
Layer8 = 1/2 oz to 1 oz
Which copper weights are correct for the Freescale SD board ?
Thanks
Doug.
Hi Dong,
Has JorgeRama_rezRivero answered you?
No I haven't had an answer yet.
Regards
Doug.
Hi Doug,
I've sent an e-mail to the guys in charge of the manufacture to check the actual numbers. I'll let you know the answer asap.
Best regards.
Jorge.
Hi Doug,
Didn't notice that. Let me confirm and I'll get back to you asap.
Best regards.
Jorge.