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Line 41: + + + + + + − + − + + + + + + + − If your component is a standard package, there's a good chance you'll be able to generate your footprint using Altium's IPC Compliant Footprint Generator. Open up the tool {{altium-shortcut|t|i}}, click "next," and search through the default styles listed. If your component is from a supported series, the tool will make your life a lot easier. Select the relevant series, and you will be prompted for a number of dimensions that should be specified on your component's datasheet. Unspecified dimensions - thinks like heel spacing, solder fillet, and courtyard and keepout areas - can typically be left as their default values.+ Line 70:
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Making Parts for PCB Libraries (view source)
Revision as of 01:49, 15 June 2016
, 01:49, 15 June 2016Finished first draft of article, got the incredibly rewarding feeling of removing the stub template from the end
===Drawing a Symbol===
===Drawing a Symbol===
To create a new schematic symbol, first find the relevant schematic library. Schematic libraries are sorted by function - i.e. power management integrated circuits (PMIC), diodes, etc. Next, lock the library you'll be working with, and double click the library to open it. If not already visible, open the "SCH Library" pane {{altium-shortcut|v|w|c|b}} and look at the top field, where there should be a list of symbols. Click "Add" to create a new symbol, giving it a name consistent with the names used in the library (''this is poorly standardized, but typically consists of, in all caps, <category_of_component>_<manufacturer_part_number>''). Your new part should then become active, bringing up a blank editing window.
To create a new schematic symbol, first find the relevant schematic library. Schematic libraries are sorted by function - i.e. power management integrated circuits (PMIC), diodes, etc. Next, lock the library you'll be working with, and double click the library to open it. If not already visible, open the "SCH Library" pane {{altium-shortcut|v|w|c|b}} and look at the top field, where there should be a list of symbols. Click "Add" to create a new symbol, giving it a name consistent with the names used in the library (''this is poorly standardized, but typically consists of, in all caps, <category_of_component>_<manufacturer_part_number>''). Your new part should then become active, bringing up a blank editing window.
===Pins===
===Pins===
Pins are how your symbol will be connected to wires when used in schematics. Enter the pin placement tool {{altium-shortcut|p|p}}, but before clicking to place your first pin, bring up the pin placement settings window {{altium-shortcut|tab}}. If designing a footprint for an IC, enter the pin name for the first pin in "Display Name," and set the "Designator" to the first pin's pin number (typically 1). If placing a pin for a symbol where a name should not appear, uncheck the "Visible" box by Display Name, and set the Designator to the appropriate number. Finally, set "Length" to 20, and exit the "Pin Properties" dialogue. You can now place your pin - '''make sure you are using a 10 point snap grid, as failing to do so can lead to errors in boards that use your symbol.''' After clicking to place your pin, you should automatically be able to place another pin, with the designator automatically incremented - enter Pin Properties {{altium-shortcut|tab}} to set the Display Name (and Designator, if needed), and then place your next pin. Repeat until all pins are placed.
Pins are how your symbol will be connected to wires when used in schematics. Enter the pin placement tool {{altium-shortcut|p|p}}, but before clicking to place your first pin, bring up the pin placement settings window {{altium-shortcut|tab}}. If designing a footprint for an IC, enter the pin name for the first pin in "Display Name," and set the "Designator" to the first pin's pin number (typically 1). If placing a pin for a symbol where a name should not appear, uncheck the "Visible" box by Display Name, and set the Designator to the appropriate number. Finally, set "Length" to 20, and exit the "Pin Properties" dialogue. You can now place your pin - '''make sure you are using a 10 point snap grid, as failing to do so can lead to errors in boards that use your symbol.''' After clicking to place your pin, you should automatically be able to place another pin, with the designator automatically incremented - enter Pin Properties {{altium-shortcut|tab}} to set the Display Name (and Designator, if needed), and then place your next pin. Repeat until all pins are placed.
As before, lock the library your footprint will be added to, then open the library. If not already visible, open the "PCB Library" pane {{altium-shortcut|v|w|p|b}}.
As before, lock the library your footprint will be added to, then open the library. If not already visible, open the "PCB Library" pane {{altium-shortcut|v|w|p|b}}.
''The component you created a symbol for above may already have a footprint in a PCB library; search for it before starting work in the next two sections, and if it exists, skip to [[#Finishing_a_Component|"Finishing a Component"]].''
===IPC Compliant Footprint Generator===
[[File:IPCWizard.png|300px|thumb|The IPC Compliant Footprint Generator]]
If your component is a standard package, there's a good chance you'll be able to generate your footprint using Altium's IPC Compliant Footprint Generator. Open up the tool {{altium-shortcut|t|i}}, click "next," and search through the default styles listed. If your component is from a supported series, the tool will make your life a lot easier. Select the relevant series, and you will be prompted for a number of dimensions that should be specified on your component's datasheet. Unspecified dimensions - thinks like heel spacing, solder fillet, and courtyard and keepout areas - can typically be left as their default values. ''If you have doubts, finish the generator and then measure the pads it produces'' - check to make sure their dimensions match the ones you intended. If in doubt, ask for a second pair of eyes to compare your part and the datasheet. ''Remember, other users will assume your part is right, so make sure it's right!''
===Drawing a Footprint===
===Drawing a Footprint===
[[File:IPCWizard.png|300px|thumb|The IPC Compliant Footprint Generator]]
If the IPC Generator isn't an option, you can place pads manually {{altium-shortcut|p|p}} and use the pad editor {{altium-shortcut|tab}} to set their layer, size, shape, hole size (if applicable) and position (once placed). "Pad" refers to any distinct feature on a PCB that corresponds to a pin in the schematic view. This includes both surface mount and through hole pads.
''The component you created a symbol for above may already have a footprint in a PCB library; search for it before starting work in this section, and if it exists, skip to [[#Finishing_a_Component|"Finishing a Component"]].''
When placing a pad, first set the designator to indicate what pad you're placing. The designator '''does not''' have to be a number, and should match the designator of any schematic pin it will be connected to. ''Multiple pads with the same designator'''''''can'''''''be placed, and will all connect to the relevant schematic pin''. This is useful for creating a polygonal pad shape out of several rectangular pads, as well as components where a single electrical net connects to multiple physical pads - for example, a Teensy board, which has multiple identical GND pins.
After setting the designator, set the layer of the pad. "Top Layer" pads are surface mount pads (and will have their copper exposed appropriately); "Multi-layer" pads will expose copper on both sides of the board, and can thus have holes put through them. If making a multilayer pad, '''check off "Plated"''' - failing to do so will trigger errors and cause your through holes to just be... well, holes. Finally, set size and shape accordingly, and hit okay to return to placing your pad. One option is to place your pad where it needs to go - the current coordinates of your mouse and snap grid size and units are displayed in the upper left, and you can freely change the units {{altium-shortcut|q}} and snap grid size {{altium-shortcut|v|g|g}} as your pads require. Alternatively, simply place the correct number of pads, and then double click on each to reopen the pad editor and set their coordinates individually.
[[File:Generic3DBody.png|300px|thumb|Select this option at the top of the "Place 3D Body" dialogue in order to load a STEP file]]
''Optional but very strongly encouraged:'' One of the strengths of the SSI PCB libraries - and a special feature of Altium - is the use of 3D models for 3D renders of PCBs. Search online for a STEP file for your component; while far from guaranteed, many components have models freely available. If possible, download one. To insert it into your footprint, use the Place 3D Body tool {{altium-shortcut|p|b}}, then select "Generic 3D Body" at the top of the window that pops up. Then click "Load from file..." and after a short import time, you should see your 3D model appear. You can now place it on your footprint. Enter 3D view {{altium-shortcut|3}} to make sure it's aligned properly; you can return to 2D view {{altium-shortcut|2}} to use the Rotation and Standoff Height options to correct its positioning, as needed.
Finally, using the line tool {{altium-shortcut|p|l}}, mark the "Overlay" (silkscreen) layer in some way to indicate how to properly orient your component. Tracing out the corners or general outline of the part aids in distinguishing it from other nearby parts, and placing a dot or circle (perhaps using the "Full Circle" tool {{altium-shortcut|p|u}}) near pin 1 or another directional feature helps ensure the component is installed correctly.
==Finishing a Component==
==Finishing a Component==
===Commit Files to SVN===
===Commit Files to SVN===
Committing files to the SSI Altium SVN is important for synchronizing files across users. '''Proper locking is required to keep commits simple and easy.''' If you've changed a single file, right click the changed library in the Projects pane, click "Version Control," and then "Commit" {{altium-shortcut|''right click''|e|c}}. If you've changed 2 or more files, right click on SSI.LibPkg, click "Version Control," and then "Commit Whole Project." You'll be brought to a menu showing all of the files you've changed, which you should quickly check to make sure has all of the files you need to commit.
You will be prompted for a commit message; describe the changes made in at least 20 characters. This minimum is imposed in an attempt to keep people from entering commits without useful messages. It's easy to get around this, but you'll be a better person for telling other people what you did. Your commit should then quickly complete, your version control state will update, your lock on the library will be released, and within 15 minutes your commit should be automatically posted to Slack. '''You are now, actually, finally, done''' - assuming your commit proceeds successfully. In the event of a failure, poke the {{slack-channel|altium}} Slack channel, and we'll work together to sort it out.
There are several hundred parts in the whole Altium library, between the contributions of SSI and Stanford Solar Car members. The process you've just completed has been gone through many times - and you benefit from everyone who spent effort to do it correctly before you. You owe that same favor to the people who will use the library after you.
[[Category:Altium]]
[[Category:Altium]]