## Footprint naming conventions

This section describes the conventions for naming of footprints used in PCB (and gEDA/gaf).
The purpose of the naming convention is to establish a standard to maintain the same naming convention through the different phases of the CAD chain. This helps in ensuring that the collaborative effort of gEDA/gaf is not lost.

### Notes

- Unless otherwise noted, numerical pin names will be used, starting from 1.
- n is for the pin count.
- m is for the pin spacing in mils.
- x is for the x dimension of the package (excluding pins). In particular this is used for the QFP package family.
- SMT means surface mount, other components are through-hole.

### Integrated circuit packages

- Dual in line packages with up to 22 100 mil spaced pins and 300 mil row spacing are called DIPn.
- Dual in line packages with 24 or more 100 mil spaced pins and 300 mil row spacing are called DIPnN.
- Dual in line packages with 100 mil spaced pins and 400 mil row spacing are called DIPnH.
- Dual in line packages with 24 or more 100 mil spaced pins and 600 mil row spacing are called DIPn.
- Shrink dual in line packages with up to 24 70 mil spaced pins and 300 mil row spacing are called SDIPn.
- Shrink dual in line packages with more than 24 70 mil spaced pins and 400 mil row spacing are called SDIPn.
- Single in line packages with 100 mil spaced pins are called SIPnN. See also JUMPER, below.
- Zig-zag in-line package are called ZIPn.
- Plastic leadless chip carrier with pin socket are called PLCCnX.

### Integrated circuit SMT packages

- Small outline SMT packages with up to 16 50 mil spaced pins and 150 mil total width are called SOn.
- Small outline SMT packages with more than 16 50 mil spaced pins and 150 mil total width are called SOnN.
- Small outline SMT packages with 50 mil spaced pins and 200 mil total width are called SOnM.
- Small outline SMT packages with up to 20 50 mil spaced pins and 300 mil total width are called SOnW.
- Small outline SMT packages with more than 20 50 mil spaced pins and 300 mil total width are called SOn.
- Small outline SMT packages with 44 or more 50 mil spaced pins and 525 mil total width are called SOn.
- Metric shrink small outline SMT packages with 0.65 mm spaced pins and 323 mil total width are called MSSOPn. NOTE: To be confirmed.
- Metric shrink small outline SMT packages with up to 44 0.65 mm spaced pins and 420 mil total width are called MSSOPnW.
- Metric shrink small outline SMT packages with over 44 0.65 mm spaced pins and 545 mil total width are called MSSOPnW.
- Shrink small outline SMT packages with 25 mil spaced pins and 420 mil total width are called SSOPnW.
- Quarter size small outline SMT packages with 25 mil spaced pins and 244 mil total width are called SSOPn.
- Thin small outline SMT packages with 21.65 mil spaced pins and 535 mil total width are called TSOPn.
- Thin small outline SMT packages with 20 mil spaced pins and 795 mil total width are called TSOPnA.
- Thin small outline SMT packages with 20 mil spaced pins and 559 mil total width are called TSOPnB.
- Thin shrink small outline SMT packages with up to 28 26 mil spaced pins and 260 mil total width are called TSSOPn.
- Thin shrink small outline SMT packages with over 28 20 mil spaced pins and 319 mil total width are called TSSOPn.
- Ultra Super Mini SMT packages with up to 16 0.5 mm spaced pins are called USn.
- Plastic leadless chip carrier SMT are called PLCCn.
- Square quad-side at pack SMT are called QFPn x.
- Rectangular quad-side at pack SMT are called QFPn R.
- Square low profile quad-side at pack SMT are called LQFPn x.
- Square thin quad-side at pack SMT are called TQFPn x.
- Square Quad-side at no-lead SMT without exposed paddle (back side contact) are called QFNn x. Pin count is n and package size is x mm.
- Square Quad-side at no-lead SMT with exposed paddle (back side contact) are called QFNn x EP. Pin count is n and package size is x mm.
- Thin profile square Quad-side at no-lead SMT without exposed paddle (back side contact) are called TQFNn x. Pin count is n and package size is x mm.
- Thin profile square Quad-side at no-lead SMT with exposed paddle (back side contact) are called TQFNn x EP. Pin count is n and package size is x mm.
- Dual in line style crystal oscillators are OSC8 and OSC14.
- 5 pin SOT SMT packages are SOT25 and SOT325.
- 6 pin SOT SMT packages are SOT26 and SOT326.

### Basic semiconductors

- Axial diodes are called ALFm. Pin 1 is the cathode.
- Conventional through hole LED is LED3 and LED5 for 3 and 5 mm respectively. Pin 1 is plus. NOTE: Should probably be changed to be in line with diode convention.
- TO transistors are TO5, TO92, TO126, TO220 etc. Suxes may apply, e.g. TO126W is for wide, TO126S is for standing, TO126SW is for standing, wide.

### Basic SMT semiconductors

- SOD diode SMT packages use their standard package name, e.g. SOD80, SOD87, SOD106A, SOD110. There are also SOD123, SOD323 with narrow pads.
- SOT transistor SMT packages use their standard package name, e.g. SOT23, SOT323. There is also an SC90.
- SOT transistor SMT packages with numbering as for diodes (pin 1 is cathode, pin 2 anode) are SOT23D, SOT323D.
- 4 pin SOT SMT packages are SOT89, SOT143, SOT223.

### Passive components

- Axial non-polar components (typically resistor, capacitor) are called ACYm.
- Bottom lead (radial) non-polar circular component (typically capacitor) is RCYm.
- Bottom lead non-polar rectangular component (typically capacitor) is BREm.
- A standard crystal is HC49, or other HC designations as required.
- Single row 100 mil pin spacing jumpers are JUMPERn. The main difference compared to single in line package is the hole size.
- Dual row 100 mil spacing headers with DIP pin numbering are HEADERn 1. Note that n is an even number.
- Dual row 100 mil spacing headers with ribbon cable numbering are HEADERn 2. Note that n is an even number.
- Angled full header connectors with latches are DIN41651 n.
- Standing full header connectors with latches are DIN41651 nS.
- DSUB connectors female are DBnF.
- DSUB connectors male are DBnM.
- Female DIN card-to-card connectors are DIN41612CnF. Add S suffix for standing.
- Male DIN card-to-card connectors are DIN41612CnM. Add S suffix for standing.
- AMP modular RJ connectors with screen are RJ11, RJ12 and RJ45.

### Passive SMT components

- Standard SMT resistors, inductors, capacitors etc are 0201, 0402, 0603, 0805, 1206, 1210, 1806, 1812, 1825, 2020, 2706.
- Tantalum SMT capacitors are EIA3216, EIA3528, EIA6032, and EIA7343. Pin 1 is plus.
- SMT electrolytics are designated by can diameter in 1/10 mm: SME33, SME43, SME53, SME66, SME84, SME104.