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Altium Schematics and Footprints Guidelines (view source)
Revision as of 03:41, 1 April 2024
, 1 AprilAdded more info from PCB design feedback for Phoenix
* Surface-mount pads: pads that only exist on the surface of a layer. They do not cut through the board. Used for surface-mount devices/technology (SMD/SMT). Usually harder for soldering but required for most chips and smaller electrical components.
* Surface-mount pads: pads that only exist on the surface of a layer. They do not cut through the board. Used for surface-mount devices/technology (SMD/SMT). Usually harder for soldering but required for most chips and smaller electrical components.
* Through-hole pads: pads that cut through the board. Used for through-hole technology (THT). Usually easier for soldering.
* Through-hole pads: pads that cut through the board. Used for through-hole technology (THT). Usually easier for soldering.
=== '''Symbols and Footprints''' ===
* <span class="s1"></span>When picking/editing symbols, make sure the pad numbers in the symbol match the pad numbers in the corresponding footprints.
* <span class="s1"></span>It is best if a symbol corresponding to a footprint can resemble the footprint as closely as possible. This can provide more clarity when trying to assemble the board.
=== Altium Schematics (SchDoc) ===
=== Altium Schematics (SchDoc) ===
* Designing the schematics means you will wire up the necessary electrical components that make your PCB board function electrically. You should refer to the datasheets of different parts to see the additional components you might need.
* Designing the schematics means you will wire up the necessary electrical components that make your PCB board function electrically. You should refer to the datasheets of different parts to see the additional components you might need.
* The Altium schematic sheet of a completed board shows a block diagram with all the electrical components of the board. Each block represents a chip and has a detailed sheet associated with it.
* The Altium schematic sheet of a completed board shows a block diagram with all the electrical components of the board. Each block represents a chip and has a detailed sheet associated with it.
** In KiCAD, this organization can be done by separating the schematics sheet into sections separated by lines or rectangle borders. Labeling different sections can also help with clarity.
* If you are confused about the functions of components shown in a schematic file, [https://www.khanacademy.org/science/electrical-engineering Khan Academy] can be a great resource for understanding electrical components and what they are used for.
* If you are confused about the functions of components shown in a schematic file, [https://www.khanacademy.org/science/electrical-engineering Khan Academy] can be a great resource for understanding electrical components and what they are used for.
* When the schematic is done, Altium will generate a netlist and import it to the PCB document. You will see all the nets turned into tracks on the PCB, which size can be customized.
* When the schematic is done, Altium will generate a netlist and import it to the PCB document. You will see all the nets turned into tracks on the PCB, which size can be customized.
** To find where the schematic of a missing part is, use the Find tool (Ctrl + F) and type in the part name.
** To find where the schematic of a missing part is, use the Find tool (Ctrl + F) and type in the part name.
=== Altium Footprints & PCB (PcbDoc) ===
=== Altium PCB (PcbDoc) ===
This is when we switch from designing the circuit to laying out the PCB itself, i.e. planning out the physical locations of each part and component.
This is when we switch from designing the circuit to laying out the PCB itself, i.e. planning out the physical locations of each part and component.
==== Layers in Altium ====
==== Layers in Altium ====
* The PCB can have many copper layers that supply power to different components running on different voltages.
* The PCB can have many copper layers that supply power to different components running on different voltages. They are called power layers/planes.
** In KiCAD, to create a power layer supplied by a surface-mount pad, you need to connect the pad to a via If the layer is supplied with a through-hole pad, there's no need for a separate via.
** Note that traces cutting through the power layer can slow down the movement of electrical charges because a longer path might be needed to travel from one pad to another. Thus, even with a power layer, it is best to leave an open, straight-line path between the pad supplying power and the pad receiving power.
* The transparent function in Altium will show two sides of every layer at the same time, which can be confusing at first and will take time to get used to.
* The transparent function in Altium will show two sides of every layer at the same time, which can be confusing at first and will take time to get used to.
* By default, all components on the same page in the schematic document will be in the same “room,” and you can move all the components together in that room.
* By default, all components on the same page in the schematic document will be in the same “room,” and you can move all the components together in that room.
* A mechanical hole for mounting certain big components (like battery holders) cannot interfere with any vias or traces, or else an electrical connection cannot be made.
* A mechanical hole for mounting certain big components (like battery holders) cannot interfere with any vias or traces, or else an electrical connection cannot be made.
* Select the layer you’re working on with tabs at the bottom of the window for easier selection of traces/components.
* Select the layer you’re working on with tabs at the bottom of the window for easier selection of traces/components.
* Blind vias (vias that do not cut through the entire board) can increase the cost of manufacturing and are sometimes less reliable (more prone to cracking). It is advised to use through vias (vias that cuts through the entire board) whenever possible.
After all the checks are done, a 3D model will be generated, and all the information can be sent to a fabrication company.
After all the checks are done, a 3D model will be generated, and all the information can be sent to a fabrication company.
=== Authors' Note ===
=== Authors' Note ===
This page is written on January 18, 2024 by [https://ssi-teams.slack.com/team/U045V0EE46Q Sam Chen] and [https://ssi-teams.slack.com/team/U04484CR1SQ Abelle Jayadinata] based on the materials covered in the [https://docs.google.com/document/d/14Ilml3RbP6zr4GWvh4mAetntX6BX1ORxpdkTMpOlbTM/edit?usp=sharing Winter 2024 Altium PCB Workshops] hosted by [https://ssi-teams.slack.com/team/U02F79U8A11 Evelyn Nutt]. We thank [https://ssi-teams.slack.com/team/U02F79U8A11 Evelyn Nutt] and [https://ssi-teams.slack.com/team/U0602L5Q31B Ethan Brinser] for their expertise and knowledge, which made the writing of this page possible.
This page is written on January 18, 2024 by [https://ssi-teams.slack.com/team/U045V0EE46Q Sam Chen] and [https://ssi-teams.slack.com/team/U04484CR1SQ Abelle Jayadinata] based on the materials covered in the [https://docs.google.com/document/d/14Ilml3RbP6zr4GWvh4mAetntX6BX1ORxpdkTMpOlbTM/edit?usp=sharing Winter 2024 Altium PCB Workshops] hosted by [https://ssi-teams.slack.com/team/U02F79U8A11 Evelyn Nutt]. It is updated on March 31, 2024 to include more detailed information from PCB design feedback. We thank [https://ssi-teams.slack.com/team/U02F79U8A11 Evelyn Nutt] and [https://ssi-teams.slack.com/team/U0602L5Q31B Ethan Brinser] for their expertise and knowledge, which made the writing of this page possible.
<nowiki>[[:Category:Altium]]</nowiki>
<nowiki>[[:Category:Altium]]</nowiki>