Imported from GitHub: mlab-modules/SPIEX01 · commit 01529f2 · license GPL-3.0

Description

SPI (bus) expander to control multiple devices from the one SPI master.

README

PCB

Board size: 50.29x50.29 mm (1.98x1.98 inches)

• This is the size of the rectangle that contains the board
• Thickness: 1.6 mm (63 mils)
• Material: FR4
• Finish: HAL
• Layers: 2
• Copper thickness: 35 µm

Solder mask: TOP / BOTTOM

• Color: Green

Silk screen: TOP / BOTTOM

• Color: White

Important sizes

Clearance: 0.4 mm (16 mils)

Track width: 0.4 mm (16 mils)

• By design rules: 0.4 mm (16 mils)

Drill: 0.5 mm (20 mils)

• Vias: 0.5 mm (20 mils) [Design: 0.5 mm (20 mils)]
• Pads: 1.0 mm (39 mils)
• The above values are real drill sizes, they add 0.1 mm (4 mils) to plated holes (PTH)

Via: 0.8/0.4 mm (31/16 mils)

• By design rules: 0.8/0.4 mm (31/16 mils)
• Micro via: yes [0.2/0.1 mm (8/4 mils)]
• Buried/blind via: yes
• Total: 34 (thru: 34 buried/blind: 0 micro: 0)

Outer Annular Ring: 0.15 mm (6 mils)

• By design rules: 0.26 mm (10 mils)

Eurocircuits class: 4B

• Using min drill 0.5 mm for an OAR of 0.15 mm

General stats

Components count: (SMD/THT)

• Top: 0/9 (THT)
• Bottom: 7/4 (SMD + THT)

Defined tracks:

Used tracks:

• 0.4 mm (16 mils) (356) defined: no

Defined vias:

Used vias:

• 0.8/0.4 mm (31/16 mils) (Count: 34, Aspect: 2.0 A) defined: no

Holes (excluding vias):

• 0.89 mm (35 mils) (54)
• 3.0 mm (118 mils) (4)

Oval holes:

Drill tools (including vias and computing adjusts and rounding):

• 0.5 mm (20 mils) (34)
• 1.0 mm (39 mils) (54)
• 3.0 mm (118 mils) (4)

Solder paste stats:

Using a paste with 87.75 % alloy, that has an specific gravity for the alloy of 7.4 g/cm³ and 1.0 g/cm³ for the flux. This paste has an specific gravity of 4.15 g/cm³.

The stencil thickness is 0.12 mm.

Side	Pads with paste	Area [mm²]	Paste [g]
Total	50	47.10	0.23

Note: this is just an approximation to the theoretical value. Margins of the solder mask and waste aren't computed.