Design for EMC and ESD - any tips?

[renato]

Design for EMC and ESD

hello,

Please how can I interconnect ground plans in a six or more layers PCBs regarding to EMC and Safety requeriments. Are there any tips ?

Why in some boards have a lot of vias to GND close to the border of board. Is it a necessary proceding ?

What a function of two points in the board (motherboards), without components, called 60 ohm ?

Sorry for many issues and for bad english.

Thanks in advance.

Renato

 

[mImoto]

The vias are mainly for avoiding that RF frecuency goes into the board by the border,I think all mobile phones have (check yours). Also they are to provide a good connection between the gnd planes in order to prevent that a plane with few vias could act like an antenna. It is important that the impedance between different points in the ground plane be as low as possible to avoid voltage differences between different points.

Normally the top and bottom layers of a mobile phone have the borders without sholder mask to connect the shieldings and with these vias.

I don't understand your second question. Maybe if you see two points in a board and 60 ohms in the solder mask it could be placed by an engineer to measure the quality of the transmision line (60ohms) in the board. This value it is affected by tolerances, etc.

Regards,

mimoto

 

[wdavid]

Are there any articles about design for EMC and ESD? Thanks