Continue to Site

Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

difference between top mask and top paste in PCB

yefj

Advanced Member level 4
Joined
Sep 12, 2019
Messages
1,192
Helped
1
Reputation
2
Reaction score
3
Trophy points
38
Activity points
7,199
Hello, in PCB i have two layer that i have trouble to visualize what they are?
TOP PASTE and TOP mask, i have trouble to visualize them on the board.
I tried to look at the manual below however i dont have a good visual example.
Thanks.


1695532127884.png
 
It's simple. paste has only openings for SMD pads, solder mask for SMD and THT. Paste pads are usually reduced, solder mask pads increased in size.
 
Hi,

Solder mask, stop mask: is needed during PCB manufacturing process. They define the openings in the outer PCB laqueur layer. This laqueur gives the main color to the finished PCB. Often green, but nowadays you can get different colors. Below this laqueur layer there is the copper layer. So when tge solder mask is "open" you have access to the copper for soldering, SMD as well as THM soldering. Here you can see the bare metal, covered with tin (silver shining) or maybe gold covered.
Non "soldering" exceptions: edge connectors. They don't get soldered, but obviously they need an opening at the laqueur layer, so you have acces to the pads for connection.
Copper traces are usually covered by the (green) laqueur. The laqueur layer is isolating (not in the meaning of safety isolation)

Solder paste, paste mask: is what you need to make the stencil to apply the SMD solder paste onto the PCB. Usually only SMD solder pads.

Klaus
 

LaTeX Commands Quick-Menu:

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top