Guidebolt Electrical Design Standard
2020-07-13
Reliability Standard
All circuit parts should be automotive-grade (AEC-Q).
Composition
All parts must be RoHS compliant.
All parts should be halogen free.
Note that "X-Free" generally allows trace amounts below a standard threshold. For example, "halogen-free" and "zero halogen" are typically used interchangeably under the max 1500ppm of total halogens (IEC 61249-2-21).
Temperature
All circuit parts must be capable of operation and storage in -40C to 105C (or better).
PCB Fabrication
All PCBs must be fabricated to IPC Class 2 (or better).
All PCBs must have rounded corners.
All PCBs must use ENIG surface finish (or better).
All PCBs must have silkscreen text.
Sensitive-signal PCBs must be fabricated with impedance control.
All PCB soldermask should be green.
All PCBs should have thermal conductivity of 0.4W/mK (or better).
PCB Text
All PCBs must have the following text:
- reference designator (one per circuit part)
- functional pin name (one per external pin)
- company name
- design ID (with revision number)
- date of manufacture (YYYY-MM-DD format)
- batch number
- serial number
PCB Mounting
All PCBs should have 4 or more mounting holes.
All PCB mounting holes must support metric screws.
All PCB mounting holes should be patterned as a rectangle.
PCB Protection
Moisture-expected PCBs must have conformal-coating or encapsulation.
Flame Resistance
All power-connectors and power-ICs must be UL94-V0.
All power-connectors should be glow-wire-capable.
Transient Protection
All external pins must have transient voltage protection.
Module Lifetime
All electrical modules must have at least 50K hours MTBF.
All electrical modules should have at least 150K hours MTBF.
Capacitors
All low-value capacitors should be MLCC.
General-use low-value capacitors should have soft-terminated ends.
All medium-value capacitors should be aluminum-polymer.