What's solder mask pcb? What's solder paste pcb?
These are normal question among new PCB enthusiasts.
Solder mask: It refers to the part of the board that needs to be coated with green oil; because it is a negative output, the parts that actually have solder mask do not actually have green oil applied, but instead are plated with tin, appearing silver-white!
Solder paste layer: This is used during machine placement and corresponds to the pads of all SMD components. It is the same size as the top layer/bottom layer and is used for opening the stencil for solder paste.
Differences between TOP PASTE and TOP SOLDER in PCBs:
soder mask pcb
1.Different DefinitionsTOP PASTE: Refers to the top layer solder paste layer, which is used to create the stencil for applying solder paste. TOP SOLDER: Refers to the top layer solder mask layer, which is used to apply green ink and other solder mask materials, preventing solder from contaminating areas that should not be soldered.
2. Different Functions of the Surface LayerTOP PASTE: The surface layer must expose all pads that need to be surface-mounted for soldering, and the openings may be smaller than the actual pads. This layer's data does not need to be provided to the PCB manufacturer. TOP SOLDER: The surface layer must expose all pads that need to be soldered, and the openings will be larger than the actual pads. This layer's data must be provided to the PCB manufacturer.3. Different SizesTOP PASTE: Its size is the same as the toplayer/bottomlayer but smaller than TOP SOLDER. TOP SOLDER: It is larger than both the toplayer/bottomlayer and TOP PASTE layers, making it the largest layer in the PCB.
Solder Mask Layers: This refers to the solder mask layer, which is the layer coated with green paint on the PCB around the pads (surface mount pads, through-hole pads, vias). It is designed to prevent solder from adhering to areas where it should not when the PCB goes through the soldering process (wave soldering), hence it is called a solder mask layer (green oil layer). Anyone who has seen a PCB should be familiar with this layer of green oil. The solder mask layer can be divided into Top Layers and Bottom Layers. The Solder layer is meant to expose the pads, which is why we see small circles or squares when only the Solder layer is displayed. These are generally larger than the pads (Solder in this context refers to the solder mask layer, used to coat with green oil and other masking materials to prevent solder from contaminating undesired areas. This layer will expose all pads that need to be soldered, and the openings will be larger than the actual pads). When generating Gerber files, one can observe the actual effect of the Solder Layers.
Paste Mask Layers: The solder paste protection layer (or solder mask layer, stencil layer) is designed for surface mount (SMD) components. This layer is used to create a stencil, where the holes on the stencil correspond to the solder points of SMD devices on the circuit board. When soldering surface mount (SMD) devices, the stencil is first placed over the circuit board (corresponding to the actual pads), then solder paste is applied, excess solder paste is scraped away with a squeegee, and the stencil is removed, leaving solder paste on the SMD device pads. The SMD devices are then attached to the solder paste (manual or pick-and-place machine), and finally, the soldering of the SMD devices is completed using a reflow soldering machine. Typically, the diameter of the holes on the stencil will be slightly smaller than the actual solder pads on the circuit board; an expansion rule can be specified to enlarge or reduce the solder paste protection layer. For different requirements of different pads, multiple rules can also be set in the solder paste protection layer. The system also provides two solder paste protection layers: the top solder paste protection layer (Top Paste) and the bottom solder paste protection layer (Bottom Paste).
soder mask pcb
After reading this article, do you have a better understanding of solder mask pcb?