PCB Fabrication

[george]

Hello Everyone,

Glad to know you on this forum.I am George from Pelcore Electronics.

Pelcore Electronics Co.,Ltd. is a high-tech enterprise which specialize
in manufacturing printed circuit boards.Our business fields mainly
involve the production,sales and service of PCB.We have not limit on
the order quantity.We can make prototype,small lots and mass production.

If you have any requirements on PCB,pls. feel free to contact us.For our
deail,pls. visit our website http://www.pelcore.com

Regards,

George Liu
Pelcore Electronics Co.,Ltd.
Tel:86-755-26416112
Fax:86-755-26521173
E-mail:george@pelcore.com
sales@pelcore.com
http://www.pelcore.com

[nsreekanth9724]

Dear All,

If we are using any blind or buried vias, should we need to provide any extra information to the pcb vendor?? How those vias appear in CNC data??
Am sorry I havent used any, thats y my doubts.

Any other guidelines for using blind and buried vias???

Rgds,
Sreekanth

[george]

Dear Sreekanth,

For conventional pcb(no blind or buried vias),you can only provide one drill file to the vendor.But for the blind or buried vias,you should provide the blind or buried via drill files and tell the vendor which layers are these blind&buried vias are used.

Regards,

George

[nsreekanth9724]

You mean to say, Blind &buried vias wont appear in CNC drill data?? If so ,how can i get the blind & buried vias details? How can i define a blind & buried via in the design? Can u explain the procedure pls?

Thanks in advance.

Sreekanth

[Smelter]

You mean to say, Blind &buried vias wont appear in CNC drill data?? If so ,how can i get the blind & buried vias details? How can i define a blind & buried via in the design? Can u explain the procedure pls?
Thanks in advance.
Sreekanth


You need to define your Blind & Buried vias in the "padstack" table of you CAD software. Most designers when they start out define their holes to appear on all layers so you can track between any layers and always have a pad and hole to stitch between the tracks.
To produce Blind & Buried vias you have to define which layers they appear on and which the are excluded from. For a four layer board, through vias and PT holes appear on all four layers. The blind vias would appear on layers 1&2 or 3&4 whereas buried vias would appear on only layers 2&3.
For this combination you produce four drill files. Through, 1-2, 2-3, 3-4. Your board maker will merge the through holes with each in turn of the other three to produce the laminates that are bonded together to make your four layer board.
Just remember your through holes will have pads on all layers, so if you have internal groundplanes you need to allow clearances for the through paths that you do not want connecting to ground. If they are to be connected to internal groundplanes then you need to define your internal pads as "thermals".
(A subject for another time)

Hope this helps.

[ganesh]

dear sir:

please give me the fabrication detail's(step's)