Questions about silk screen and Pads on professional grade bare pcbs.

[alphaai]

1) The picture on the left has red silkscreen right?
So the layer that is bright red, what layer would that be in Eagle.
and the layer that is dark red, what layer would that be in eagle.

2) Also the pads, the silver things, is that solder? or is that something else.

I understand that you could manually place solder paste onto the pads
but if this is a bare pcb,

3)what material is that? Is it copper? gray copper? lol

4) I can see on the left picture, name layer, there is an exclamation mark, which has the exclaimation mark cover two vias at least. Would that cause the vias to be non conductive at all?

5) The picture on the right, which has the soldered vias, the soldered joints are huge, which makes me believe the vias must be big as well. hmmm.
I mean hes done a good job for a double layer board with vias. But anyone knows where he could have improved?

Look forward to your guys responses.

Thanks,

Ben

 

[cobra1]

Hi, the red layer is all the same layer,its called solder mask or solder stop. it looks like 2 different colours because of the copper tracks underneath, the light red is where there is copper. the dark is where there is none. In eagle this layer sorts itself out, i have never had to manually do anything to this layer.
The pads are coated in tin during manufacture to protect the copper and make it easier to solder.

The ! mark is a silkscreen, it does not affect the pcb electronically, it is mainly used simply for reference. However i have read that it is considered bad practice to put silkscreen over vias, sometimes however it is unavoidable.

The PCB on the right is home made, thus meaning that vias have to be drilled and then solder a small peice of wire in the hole to connect both sides, on a pro PCB the via is usually 0.6mm hole and the 2 sides are connected using a type of electro plating process, with home made PCBs large vias are usually unavoidable.