the PCB masks and layers

[moustafaali]

pcb basic layers schematic

i ask about the definitions of some important points appear to me when i try to make pad stack assignment in expedition
any one know these definitions or know ref. has these definitions please reply

1- top mount
2-bottom mount
3-plane clearance
4-plane thermal
5-top mount slder mask
6-bottom mount solder mask
7-top mount solder paste
8-bottom mount solder paste

and what is the difference between the pad and the padstack
and the silk screen and the soldermask


i know that these basic questione but these questions confuse me

please help
moustafa

 

[dunn]

Have a look at **broken link removed**

 

[moustafaali]

thank you for this link this is a good documentation

 

[sp_harikrish]

Top mount is - top layer
Bottom mount - bottom layer
Silkscreen is - Component outline

Pad is general term and padstack is pad in which all the layer it exist.

 

[gujju73]

Solder paste is where SMT parts mounting pads. That's were the solder paste will go before SMD component placement. Which in turn go to reflow oven and part will be soldered to the PCB.

 

[Rame]

Hi,

Check this websites for your Pcb Basic's,if this is not sufficient then google saying
pcb glossary in the tool bar ,you will gets tons and tons of articles related to this.

**broken link removed**

https://www.goldengategraphics.com/pcgloss.htm

**broken link removed**

**broken link removed**


Hope this helps you,


Regards,

Ramesh

 

[ahsoka]

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