First PCB Design Revised. Still looking for errors.

[BubbaGump]

I made a few changes to my original PCB design for a small 1W stereo amplifier. I'm still pretty new at all of this, and I was hoping someone could point out some errors, if there are any, or just tell me how to improve my board. Pictures of both layers of the board are attached; please take a look. Thanks!

 

[Juergen Knoop]

who would etch the pcb, you or a boardhouse?
regards

 

[BubbaGump]

I have no idea how to do that. I used ExpressPCB, so I was planning on just having them do it. Any better suggestions?

 

[Juergen Knoop]

ok, there are several pitfalls, if you want to do the board yourself.
Of course the boardhouse has no problems with thin wires are and vias.
regards

 

[rehanabid]

Bubba:
Its a nice effort for a new person with chipamps.
Two points, such a simpler design could easily be made a single sided PCB.
Power track is very thin, make it thicker and place a decoupling capacitor of .1 uf near IC. Also make output track a bit thicker.

 

[BubbaGump]

Well, thanks. My design has two layers (one layer has red tracks, and the other green) but the components will still all be mounted on one side, correct? Also, where exactly do I put that capacitor? And someone told me this specifically:

"You need to use star ground, the R6 ground which is part of the output filter should not share the same ground of the input ground. The input ground should be on its own trace run to the main GND point, same for the output. The power supply caps ground should also run to the GND without sharing with the input ground."

Can someone please explain to me what that means? I'll do some tweaking and repost my design, but I'm a bit confused.

 

[rehanabid]

capacitor should be placed as near as possible to IC and other pin is to be grounded.
As for second part regarding "star ground" this refers to grounding topology, you can find lot of info just google around "power supply grounding topolgies, or grounding topologies"
As for me I prefer the ground plane. I dont use star ground topology, but u ll find many supporters of the same, its upto individual which toplogy one wants to use.

 

[peranders]

Avoid sharp corners of the traces. It's easier to etch of in 90 deg corners. Use 45 degrees angels as much as possible, or even round corners if you software handles that. An example can be found here.