Interconnect selected layers on PCB

[andre_luis]

Hi,

I need perform routing bellow a QFN-64 component.
But this component have a wide land pattern on TOP layer, remaining few space to work.

It is possible to use vias connecting other layers under this land ?

Thans in advance.
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[karesz]

Hi,
you means barryed via`s, or some their are from on surface (here practically from bottom) to some internal layer(s) _blind via`s?
They are of course both possible, its eventually a price question :-(.
Only the pad (or land pattern) under your IC is on some low potential to contact_usually to GND (or most negative), but consult every times pls the right data sheets...
K.

 

[andre_luis]

Hi karesz,

Thanks a lot.
Actually, the price is prohibitive.

R[]´s

 

[karesz]

Hi Ramos,
I think price isnt in all cases so catastrophic, but maybe is country depending too...
For some project I did asked my local PCB deliverer; I was relative surprised(positive), than he told me that I have to calculate with so 15-20 % overprice for blind Vias.
Maybe you can contact other/foreign producers too?
Grüsse!
K.

 

[PCBWING]

Including blind and buried hole PCB production complex, they need to drill several times, so the price should be higher.