Holes on PCB ground

[terry]

Hi,

Sometimes I see holes on the PCB ground. Why? Could anyone teach me?

There is an example here:
http://hepmail.phys.sinica.edu.tw/~atlas/Tile/Dual.JPG

Thanks!

 

[Pere Pala]

Hi,

Sometimes I see holes on the PCB ground. Why? Could anyone teach me?

There is an example here:
http://hepmail.phys.sinica.edu.tw/~atlas/Tile/Dual.JPG

Thanks!

These are plated-through holes that connect to other ground areas in
the PCB.

 

[Phil Newman]

Hi,

Sometimes I see holes on the PCB ground. Why? Could anyone teach me?

There is an example here:
http://hepmail.phys.sinica.edu.tw/~atlas/Tile/Dual.JPG

Thanks!

These are commonly known as "ground vias" or "hermetic vias" and ensure that
the ground area (the bit with the holes) are grounded properly. Grounding
on PCBs (or other substrates) are essential, particularly at high frequency.

Hope this helps,

Phil

 

[tlbs101]

Hi,

Sometimes I see holes on the PCB ground. Why? Could anyone teach me?

There is an example here:
http://hepmail.phys.sinica.edu.tw/~atlas/Tile/Dual.JPG

Thanks!

Since the MAX3288 is a high speed LASER driver, operating at Gbps
speeds, RF rules apply to making the PCB. The trace impedances must
be held to the designed transmission line impedance. The trace
impedances are most likely 50 Ohms. Microstripline techniques are
probably used to maintain the constant impedance.

Equal-spaced and well-spaced vias connecting the top ground plane with
the image ground plane help to maintain the constant transmission line
impedance for the microstrip signal lines.

Hope this helps!

Tom

 

[john jardine]

Hi,

Sometimes I see holes on the PCB ground. Why? Could anyone teach me?

There is an example here:
http://hepmail.phys.sinica.edu.tw/~atlas/Tile/Dual.JPG

Thanks!

The PCB holes are filled with a (plated) metal sleeve so can electrically
connect the top surface of a PCB to its bottom surface.
In the photo it looks like they've just been used to electrically stitch
together the top and bottom PCB 'power-plane' areas.

Also, a group of plated through holes near to a soldered, surface mount,
power device can act to allow heat to easily transfer from a top PCB
cooling area to a PCB bottom cooling area. No extra heatsinks need then to
be bought.
regards
john