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weatherbox:dragonfruit:pcb_rules [2016/02/24 20:47] garrettz created |
weatherbox:dragonfruit:pcb_rules [2021/09/19 21:59] (current) |
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| - | ==== PCB Professional Design Rules ==== | + | ====== PCB Professional Design Rules ====== |
| These 28 Basic PCB design guidelines set out best practice to reduce the cost of your boards and to minimize the risk of errors arising during manufacture. | These 28 Basic PCB design guidelines set out best practice to reduce the cost of your boards and to minimize the risk of errors arising during manufacture. | ||
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| High power boards have different rules especially in terms of spacing, traces size and power isolation. Manufacturers have different requirements; make sure you read their own guidelines before sending your design. Naming and file formats also vary depending on the manufacturers. | High power boards have different rules especially in terms of spacing, traces size and power isolation. Manufacturers have different requirements; make sure you read their own guidelines before sending your design. Naming and file formats also vary depending on the manufacturers. | ||
| - | PCB Layout | + | |
| - | 1. Create your board frame on a 0.05” grid. Make the lower left corner start at 0,0. | + | //Taken from [[http://blog.upverter.com/post/102541308937/28pcb|Upverter Blog]]// |
| - | 2. Usually the board frame is rectangular. For specific reasons you could also do other types of shapes such as polygons. | + | ====PCB Layout==== |
| - | 3. Stick parts on a 0.05” grid. You should not break this rule unless you have a very good reason. | + | - Create your board frame on a 0.05” grid. Make the lower left corner start at 0,0. |
| - | 4. Any LED should be labeled with its purpose (power, status, D4, Lock, etc). | + | - Usually the board frame is rectangular. For specific reasons you could also do other types of shapes such as polygons. |
| - | 5. Idem for connectors: e.g Vin, Port1, Batt, 5V, etc. | + | - Stick parts on a 0.05” grid. You should not break this rule unless you have a very good reason. |
| - | 6. Idem for pins where applicable: e.g TX, Power, +, -, Charge, etc. | + | - Any LED should be labeled with its purpose (power, status, D4, Lock, etc). |
| - | 7. Idem for switches and switch states: eg. On, Off, USB etc. | + | - Idem for connectors: e.g Vin, Port1, Batt, 5V, etc. |
| - | 8. When applicable, it is better to avoid having vias go through the silkscreen when adding labels. | + | - Idem for pins where applicable: e.g TX, Power, +, -, Charge, etc. |
| - | 9. Group components together. For example the resistors surrounding a transistor in your schematic will also be grouped together on the PCB. | + | - Idem for switches and switch states: eg. On, Off, USB etc. |
| - | 10. Minimum drill size should be 15 mil. | + | - When applicable, it is better to avoid having vias go through the silkscreen when adding labels. |
| - | 11. Minimum annular ring size should be 7 mil. | + | - Group components together. For example the resistors surrounding a transistor in your schematic will also be grouped together on the PCB. |
| - | 12. 7 mil is the minimum size for traces. 8mil is acceptable. When possible try to keep the traces size to 10mil. | + | - Minimum drill size should be 15 mil. |
| - | 13. Use thicker traces for power lines. 12mil=100mA max, 16mil=500mA max etc. | + | - Minimum annular ring size should be 7 mil. |
| - | 14. 7mil between traces and space is reasonable. | + | - 7 mil is the minimum size for traces. 8mil is acceptable. When possible try to keep the traces size to 10mil. |
| - | 15. Avoid 90 degree corners. Straight lines with 45 degree corners are preferable. | + | - Use thicker traces for power lines. 12mil=100mA max, 16mil=500mA max etc. |
| - | 16. Where applicable use a ground pour on top/bottom layers. | + | - 7mil between traces and space is reasonable. |
| - | 17. To prevent pours from shorting to traces make sure you use a 10mil isolation setting on any of the ground pour. | + | - Avoid 90 degree corners. Straight lines with 45 degree corners are preferable. |
| - | Schematic Layout | + | - Where applicable use a ground pour on top/bottom layers. |
| - | 18. Use a GND symbol for all the GND connections. | + | - To prevent pours from shorting to traces make sure you use a 10mil isolation setting on any of the ground pour. |
| - | 19. Use appropriate power symbols for All VCC, 5V, 3.3V etc. | + | ====Schematic Layout==== |
| - | 20. Add color notes to separate a complex design into various smaller bits (for example,charge circuit, accelerometer, etc). | + | - Use a GND symbol for all the GND connections. |
| - | Footprints | + | - Use appropriate power symbols for All VCC, 5V, 3.3V etc. |
| - | 21. All footprints need a reference designator {{refdes}}. If you come across a part on a board that doesn’t have this, you should change it and save the library. For parts requiring it a pin one marker should be defined. | + | - Add color notes to separate a complex design into various smaller bits (for example,charge circuit, accelerometer, etc). |
| - | 22. All footprints need silkscreen indicators showing mechanical sizes, dimensions, or anything wired about the part. | + | ====Footprints==== |
| - | 23. To prevent it from flaking off easily silkscreen within a footprint or board should not go over pads or metal that will be exposed. | + | - All footprints need a reference designator (refdes). If you come across a part on a board that doesn’t have this, you should change it and save the library. For parts requiring it a pin one marker should be defined. |
| - | 24. Top component layer should be marked by a red centre cross. | + | - All footprints need silkscreen indicators showing mechanical sizes, dimensions, or anything wired about the part. |
| - | 25. Package outline layers should outline the actual package size. | + | - To prevent it from flaking off easily silkscreen within a footprint or board should not go over pads or metal that will be exposed. |
| - | 26. The Top Courtyard layer should include all of the pins. | + | - Top component layer should be marked by a red centre cross. |
| - | 27. When adding a footprint make sure you add a solder mask. | + | - Package outline layers should outline the actual package size. |
| - | 28. Every new footprint and part will have a human readable description. | + | - The Top Courtyard layer should include all of the pins. |
| + | - When adding a footprint make sure you add a solder mask. | ||
| + | - Every new footprint and part will have a human readable description. | ||