Design rules » Historie » Revision 26
Revision 25 (Maximilian Seesslen, 10.11.2023 11:47) → Revision 26/31 (Maximilian Seesslen, 10.11.2023 11:49)
h1. Design rules
h2. PCB facturing
"Aisler Specs":https://community.aisler.net/t/pcb-specifications
"Calc":https://www.omnicalculator.com/other/pcb-trace-resistance
"Description":https://www.eurocircuits.com/tolerances-on-copper-thickness/
"Power":https://www.mikrocontroller.net/articles/Leiterbahnbreite
|Base material | FR4 TG 140° |
| |Technolam UV-Block FR-4-86 681 |
|PCB Thickness | 1.6mm (0.063inches) |
|Base copper thickness | 18µm |
|Min. processed copper thickness| 35µm |
A 15cm trace with minimum width (0.15mm) has an resistance of ca. 0,5 Ohm. A shortcut would limit to 6 Amps.
A 2cm trace has an resistance of 0,07Ohm; 42 Amps.
| 15cm | 0.15mm | 0.5 Ohm | |
| 15cm | 0.2mm | 0.37 Ohm | |
| 15cm | 0.25mm | 0.29 Ohm | 0,5A@Delta-10° |
An QFN pad has an width of 0,25mm;
h2. Traces
min. drill diameter: >=0,3mm
min. trace width: 0,150mm
pad diameter DuKo: 0,6mm (spec. 0,7mm?) !!
hole to hole: 0,35mm (not specificated. Via was missing. Wert empirisch. Does not happen when following other design rules)
Distance to cuts 0,35mm (cut-through to easily by grinding)
* Power: 0,2 distance; 0,2 width
* Powerline (240V): 1,5 distance; 2,5 width (CANSwitch)
2,5mm: ca. 1.5A bei 10°C rise
!design_rules.png!
h2. Text varnish
Lack:
Gut, fuer längeren Text:
0,7x0,7; Staerke 0,1mm (NUC64Debug V0.2.x)
(zu klein fuer Schrift in Copper)
Zu klein:
0,4x0,4; Staerke: 0,05 (CAN/IO)
Geht noch, nicht kleiner:
*0,6x0,6; Staerke: 0,05* (CANDisplay::Eval; Miniminutnik)
Geht noch, eher nicht kleiner, manche Labels nicht mehr eindeutig:
0,55x0,55; Staerke: 0,15 (CAN/IO v0.6.x, einzelne Referenzen nur erratbar)
h2. Text copper
Copper:
Gut unverzinnt:
0,6x0,6; Starke 0,08mm
schlecht verzinnt:
0,7x0,7; Staerke 0,1mm (NUC64Debug)
nearly ok:
0,75x0,75; Staerke 0,15mm (Candisplay Eval)
Still dots not ok:
0,8x0,8; Staerke 0,2mm (CANIO 0.6.x)
next test:
0,85x0,85; Staerke 0,25mm (EEPROM)
h2. Standard LEDs; 2V @ 3V
120 Ohm: very bright
240: bright, ok for blinking, still to bright for permanent on
480: should be the usual case
1k Ohm: very dark. eg. ok for power LED
h2. PCB facturing
"Aisler Specs":https://community.aisler.net/t/pcb-specifications
"Calc":https://www.omnicalculator.com/other/pcb-trace-resistance
"Description":https://www.eurocircuits.com/tolerances-on-copper-thickness/
"Power":https://www.mikrocontroller.net/articles/Leiterbahnbreite
|Base material | FR4 TG 140° |
| |Technolam UV-Block FR-4-86 681 |
|PCB Thickness | 1.6mm (0.063inches) |
|Base copper thickness | 18µm |
|Min. processed copper thickness| 35µm |
A 15cm trace with minimum width (0.15mm) has an resistance of ca. 0,5 Ohm. A shortcut would limit to 6 Amps.
A 2cm trace has an resistance of 0,07Ohm; 42 Amps.
| 15cm | 0.15mm | 0.5 Ohm | |
| 15cm | 0.2mm | 0.37 Ohm | |
| 15cm | 0.25mm | 0.29 Ohm | 0,5A@Delta-10° |
An QFN pad has an width of 0,25mm;
h2. Traces
min. drill diameter: >=0,3mm
min. trace width: 0,150mm
pad diameter DuKo: 0,6mm (spec. 0,7mm?) !!
hole to hole: 0,35mm (not specificated. Via was missing. Wert empirisch. Does not happen when following other design rules)
Distance to cuts 0,35mm (cut-through to easily by grinding)
* Power: 0,2 distance; 0,2 width
* Powerline (240V): 1,5 distance; 2,5 width (CANSwitch)
2,5mm: ca. 1.5A bei 10°C rise
!design_rules.png!
h2. Text varnish
Lack:
Gut, fuer längeren Text:
0,7x0,7; Staerke 0,1mm (NUC64Debug V0.2.x)
(zu klein fuer Schrift in Copper)
Zu klein:
0,4x0,4; Staerke: 0,05 (CAN/IO)
Geht noch, nicht kleiner:
*0,6x0,6; Staerke: 0,05* (CANDisplay::Eval; Miniminutnik)
Geht noch, eher nicht kleiner, manche Labels nicht mehr eindeutig:
0,55x0,55; Staerke: 0,15 (CAN/IO v0.6.x, einzelne Referenzen nur erratbar)
h2. Text copper
Copper:
Gut unverzinnt:
0,6x0,6; Starke 0,08mm
schlecht verzinnt:
0,7x0,7; Staerke 0,1mm (NUC64Debug)
nearly ok:
0,75x0,75; Staerke 0,15mm (Candisplay Eval)
Still dots not ok:
0,8x0,8; Staerke 0,2mm (CANIO 0.6.x)
next test:
0,85x0,85; Staerke 0,25mm (EEPROM)
h2. Standard LEDs; 2V @ 3V
120 Ohm: very bright
240: bright, ok for blinking, still to bright for permanent on
480: should be the usual case
1k Ohm: very dark. eg. ok for power LED