1. The concept of “Layer”
Due to special requirements such as anti-interference and wiring, PCB boards used in newer electronic products not only have upper and lower sides for wiring, but also have interlayer copper foils that can be specially processed in the middle of the board. For example, current computer motherboards mostly use printing plate materials with more than 4 layers. These layers are relatively difficult to process and are mainly used for setting up power wiring layers with simple traces (such as Ground Dever and Power Dever) that are often routed by filling large areas (such as External Plane and Fill). Communication between the surface layers in the upper and lower positions and the intermediate layers needing to be connected is achieved through “Via” in the software.
With the above explanation, it is easy to understand the related concepts of “multi-layer pad” and “wiring layer setting”. For example, many people may complete the wiring, only to realize that many terminals of the connection have no pads. This is usually because they overlooked the concept of “layer” when adding the device library and did not define and encapsulate their own pad characteristics as “multi-layer (Multi-Layer)”. It is important to remember to turn off any unused layers on the printed board to avoid unnecessary complications and detours.
2. Via
To connect lines between layers, via holes are drilled at the intersection of wires needing connection. Via holes have metal plated on their inner walls via chemical deposition to connect copper foils between layers. The upper and lower sides of the via are shaped like ordinary pads and can connect directly to upper and lower lines, or remain unconnected. When designing circuits, the following principles should be considered: (1) Minimize the use of vias to avoid gaps between vias and surrounding entities, especially in middle layers. Select “On” in the Via Minimization submenu to resolve automatically. (2) The larger the required current carrying capacity, the larger the required via hole sizes, such as those connecting power supply and ground layers with other layers.
3. Silkscreen layer (Overlay)
To aid in circuit installation and maintenance, logos, text codes, and other markings are printed on the PCB surfaces, including component labels, nominal values, outlines, manufacturer logos, and production dates. Proper silkscreen layout is important to prevent text blockages or smearing during assembly and maintenance.
4. The particularity of SMD
SMD packages in Protel have single-sided element pin holes. Surface definitions are crucial to avoid issues like “Missing Plus” and component annotations can only be placed along the component surface.
5. Grid-like filling area (External Plane) and filling area
Network filling areas are processed as mesh while filling areas retain copper foil completely. These different types have specific uses in circuit design, with network filling areas suppressing high-frequency interference and filling areas being suitable for smaller areas.
6. Pad
Pads are essential in PCB design, and factors such as shape, size, layout, and component conditions should be considered when selecting them. Customizing pads may be necessary for specific applications, such as using teardrop shapes for high heat or current components.
7. Various types of film
Solder flux film improves solderability on pads, while solder mask prevents tin from sticking to non-pad areas during soldering. These two films work together to ensure proper soldering conditions, with settings like “solder Mask Enlargement” to be adjusted accordingly.
8. Flying line
Flying lines are used for observation during automatic routing and can help optimize component positions for efficient routing. They can also be used to identify networks that have not been deployed for manual compensation if needed during high-volume production.
Due to special requirements such as anti-interference and wiring, PCB boards used in newer electronic products not only have upper and lower sides for wiring, but also have interlayer copper foils that can be specially processed in the middle of the board. For example, current computer motherboards mostly use printing plate materials with more than 4 layers. These layers are relatively difficult to process and are mainly used for setting up power wiring layers with simple traces (such as Ground Dever and Power Dever) that are often routed by filling large areas (such as External Plane and Fill). Communication between the surface layers in the upper and lower positions and the intermediate layers needing to be connected is achieved through “Via” in the software.
With the above explanation, it is easy to understand the related concepts of “multi-layer pad” and “wiring layer setting”. For example, many people may complete the wiring, only to realize that many terminals of the connection have no pads. This is usually because they overlooked the concept of “layer” when adding the device library and did not define and encapsulate their own pad characteristics as “multi-layer (Multi-Layer)”. It is important to remember to turn off any unused layers on the printed board to avoid unnecessary complications and detours.
2. Via
To connect lines between layers, via holes are drilled at the intersection of wires needing connection. Via holes have metal plated on their inner walls via chemical deposition to connect copper foils between layers. The upper and lower sides of the via are shaped like ordinary pads and can connect directly to upper and lower lines, or remain unconnected. When designing circuits, the following principles should be considered: (1) Minimize the use of vias to avoid gaps between vias and surrounding entities, especially in middle layers. Select “On” in the Via Minimization submenu to resolve automatically. (2) The larger the required current carrying capacity, the larger the required via hole sizes, such as those connecting power supply and ground layers with other layers.
3. Silkscreen layer (Overlay)
To aid in circuit installation and maintenance, logos, text codes, and other markings are printed on the PCB surfaces, including component labels, nominal values, outlines, manufacturer logos, and production dates. Proper silkscreen layout is important to prevent text blockages or smearing during assembly and maintenance.
4. The particularity of SMD
SMD packages in Protel have single-sided element pin holes. Surface definitions are crucial to avoid issues like “Missing Plus” and component annotations can only be placed along the component surface.
5. Grid-like filling area (External Plane) and filling area
Network filling areas are processed as mesh while filling areas retain copper foil completely. These different types have specific uses in circuit design, with network filling areas suppressing high-frequency interference and filling areas being suitable for smaller areas.
6. Pad
Pads are essential in PCB design, and factors such as shape, size, layout, and component conditions should be considered when selecting them. Customizing pads may be necessary for specific applications, such as using teardrop shapes for high heat or current components.
7. Various types of film
Solder flux film improves solderability on pads, while solder mask prevents tin from sticking to non-pad areas during soldering. These two films work together to ensure proper soldering conditions, with settings like “solder Mask Enlargement” to be adjusted accordingly.
8. Flying line
Flying lines are used for observation during automatic routing and can help optimize component positions for efficient routing. They can also be used to identify networks that have not been deployed for manual compensation if needed during high-volume production.
