4.9 KiB
PCB Footprints
Common Guidelines
- Origin/anchor on part centre
- Pad 1 on the left and then at the top
- Ensure rotational symmetry for symmetric parts
- Text has size 1mm x 1mm and thickness 0.15mm (checked automatically)
- Aim to conform to IPC-7351B footprint design
- Reference and Value fields:
- On the
F.Fab
layer (checked automatically) - May only be hidden for non-functional parts such as mounting holes
- Place just outside the part courtyard, without overlapping the part
- If the part is usually arrayed vertically, place on left and right, with text running vertically
- If the part is usually arrayed horizontally, place on top and bottom, with text horizontal
- Otherwise, prefer top and bottom
- Reference on top or left, value on bottom or right
- On the
- Fabrication Layer:
- Include reasonably accurate part drawing
- Courtyard:
- Lines 0.01mm thick on 0.05mm grid (checked automatically)
- Clearance:
- 0.25mm normally
- Other clearances as applicable per-package
- Silkscreen:
- May be omitted only for very small footprints where inclusion would impede close packing or soldering, or for non-functional parts such as mounting holes
- All lines 0.15mm thick (checked automatically)
- Provide pin 1 indicator where applicable
- No silk over exposed copper
- Internal drawings where possible
- Not for ICs with exposed pads
- Be careful of situations where the height of the silk could cause soldering issues
- Placement alignment indications for no-lead packages will need to be external
- In general prefer less silk visible post-assembly
Associated Documentation
- Has the footprint been validated in practice? With what symbol? Where?
- Link to any specific layout recommendations or requirements
- Any other notes / gotchas
Footprints in unchecked/
have not been standardised or documented yet.
Footprints
0201, 0201-L, 0402, 0402-L, 0603, 0603-L, 0805, 1206
Imperial sized chip device.
- Footprints are IPC-7351B compliant
- Default NOMINAL environment,
-L
parts in LEAST environment - Clearance and courtyards are all 0.25mm from the pad edges
- Fabrication layer shows typical device and terminal size
- Generally all tested in production but are by no means process-optimised
0603-LED
0603 (aka 1.6mm x 0.8mm) sized LED.
- Standard 0603 footprint pads
- LED polarity arrow with pin 1 as cathode
- Farnell codes:
- Red 2290329
- Green 2290328
- Amber 2290330 ("yellow")
- Blue 1686062
0805-LED
0805 (aka 2.0mm x 1.25mm) sized LED.
- Standard 0805 footprint pads
- LED polarity arrow with pin 1 as cathode
- Farnell codes:
- Red 5790840
- Green 5790852
- Yellow 5790876
- Orange 5790864
- Blue 8554749
SOIC, MSOP, LQFP, QFN, DFN, LGA, LPCC, others
Standard footprints, either from IPC-7351B in nominal environments or otherwise modified for a specific package or device.
Generated automatically by scripts/icmod.py
. Please see the notes by each
footprint in that script for further details.
MICROUSB_MOLEX_47589-0001
MicroUSB connector.
- Farnell 1568023
- Not tested yet
- Bottom mount (so USB cables will be upside down if footprint is on top)
- Footprint uses round drill hits for oblong slots
- Probably wants hand soldering the through connections
MICROSD_MOLEX_503398-1892
MicroSD card holder.
- Farnell 2358234
- Used successfully
M3_HOLE, M3_MOUNT
M3 sized mounting holes.
- The
M3_MOUNT
variant includes a no-mask region with extra drill hits for a locking washer. - The
M3_HOLE
courtyard does not include space for a bolt head or washer (as it may not always be required) so be sure to check this or use theM3_MOUNT
variant.
WIREPAD
3mm diameter circular copper pad. Useful for particularly large testpoints and pads for soldering wires to.
PowerFLAT5x6
Dual switching N-MOSFET (not linked), 9mΩ Rdson.
PowerPair3x3
Dual switching N-MOSFET totem pole, 14mΩ (upper) and 7mΩ (lower) Rdson.
PowerPAK SC-75-6L-Single
Single switching N/P MOSFET.
- SiB452DK, SiB433EDK
- http://www.vishay.com/docs/68832/sib452dk.pdf
- http://www.vishay.com/docs/65652/sib433ed.pdf
PowerPAK-SO-8
Single switching P-MOSFET, 3mΩ Rdson.
SON2x2
Single switching P-MOSFET, 59mΩ Rdson.
VML1006
Single switching N MOSFET.
- RV2C010UN
- http://rohmfs.rohm.com/en/products/databook/datasheet/discrete/transistor/mosfet/rv2c010unt2l-e.pdf
VLS201610HBX-1
VLS201610HBX-1 Inductor series.