difference between top mask and top paste in PCB

WBahn

Joined Mar 31, 2012
29,496
Don't know what more to say. The solder mask is a coating applied to the board to protect the copper. If you want to stick components onto the copper, there need to be openings in the solder mask to let you do that. This is what the solder mask layer is for -- you are saying where you want there to NOT be a solder mask on the board.

For surface mount components, you usually lay down a layer of solder paste on the pads, then stick the components to the paste and heat up the board enough to melt the solder paste. You have to indicate where you want solder paste applied to the board. That's what the solder paste mask is for.
 

Jon Chandler

Joined Jun 12, 2008
852
Two points to note:
.● If you look at the soldermask layer Gerber file, it's shown in reverse – the dark areas are holes in the soldermask, where component pads will be exposed for soldering. With rare exceptions, the soldermask layer is generated automatically by the PCB layout software

● The solder paste layer is generated automatically by the PCB layout software – no extra steps are required to create it. The PCB fab house may alter it to ensure the proper amount of solder is applied to each pad.

The solder paste file is used to create a solder paste stencil, which is used to spead solderpaste on the circuit board for automated assembly.
 

Thread Starter

yef smith

Joined Aug 2, 2020
602
Hello ,So if i understand correctly solder mask is the coating aplied on top the whole PCB?

and solder paste is the places of the pads where we put the solder on top of the pads?
Thanks.
 

Thread Starter

yef smith

Joined Aug 2, 2020
602
Hello, In Altium i have different names , top overlay and top solder.
What is the solder paste and soldr mask layers ?
Thank.

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