Hi,
can anybody tell me how do we decide on dimension of drill,top layer,solder mask,paste mask
EX:
if the drill dia is 'a'
then what is top layer,solder mask,paste mask dimensions
thanks in advance Smile Smile
Added after 6 minutes:
hi,
The solder mask layer is used to tell the fabrication house where to apply tin and where not to. The areas of the circuit board that do not get plated with tin are covered with a material
known as solder mask. Solder mask is usually light green or blue, about 1 to 2 mils thick, and covers the bare copper to protect it from oxidizing as well as insulating it electrically.
Solder paste must be applied to all surface mount component pads before the board is sent through a solder re-flow or infrared oven. To do this, the assembly house needs a paste mask layer. The paste mask layer tells the fabrication house exactly where the paste needs to go.
This paste insures that the surface mount pins solder properly to the pads of the circuit board. Through-hole components do not need solder paste. When you make a padstack for a surface mount pin, you should always add a paste mask layer obstacle