Ground Plane
Ground Plane
(OP)
Hello,
What is the main purpose of having a ground plane in a Pcb design and what is the difference between a solid and a grid ground Plane?
I have a microcontroller and I am thinking of passing a ground plane underneath it, such that it would be protected against EmC and stray magnetic field.I am saying wright?
Thanks in Anticipation
What is the main purpose of having a ground plane in a Pcb design and what is the difference between a solid and a grid ground Plane?
I have a microcontroller and I am thinking of passing a ground plane underneath it, such that it would be protected against EmC and stray magnetic field.I am saying wright?
Thanks in Anticipation





RE: Ground Plane
The ground plane provides a low impedance area to dissipate any higher frequency garbage that may be present. Otherwise, any noise will find itself in every area of your circuit and in addition, ground traces will have different impedances causing 'ground loops', although on a smaller scale. Its definately something you want to implement. It may work ok without it in the lab but when it gets out side of the protected area, all kinds of strange things can and will happen.
RE: Ground Plane
Before solder-mask-over-bare-copper board processes, it was common to tin-plate or tin-reflow the copper under the solder mask. When a board went through wave solder, solder would be pulled under and lump under the mask. When the board cooled, the different expansion rates of FR4 and solder would result in the board warping. Laying down a grid greatly reduced this warping issue.
In modern boards, the copper may be plated-up to the design copper thickness. Hatching the ground reduces the amount of plating solution needed to do this. Additionally, some high volume board houses may factor costs of copper recover out of etching solutions. In some reflow situations, the copper expansion may again result in possible warping issues if the board is thin or the ground plane size is large.
RE: Ground Plane
Regards,
Steve Smith, C.I.D.
Product Engineer
Staco Energy Products Co.
www.stacoenergy.com
RE: Ground Plane
RE: Ground Plane
I wonder how many mfg's have problems with equipment that they don't know about? Usually the result of bad layout, etc is resetting of the micro or getting an interrupt when one should not occur. Generally, the device resets and starts over so several people would attribute this to a "power glitch" and never notify the mfg. If this is for something critical I would use a ground plane and more important is to follow board layout guidelines.
RE: Ground Plane
RE: Ground Plane
No a ground plane will not fix a bad layout but it may help. If you have to add another layer for just a ground plane then you have to look at costs vs benefits (of course). The point is, the ground on the PCB should occupy as much space as possible to keep the impedance low. Whether this is a whole layer or 1/4 of one layer it is still better than none. The only increased cost comes if you have to add a layer to get a decent ground plane. Now if your doing some high frequency design for comms or something then maybe a whole layer might be wise but for a microcontroller its generally not necessary.
RE: Ground Plane
RE: Ground Plane