Backplane Connector Decision

Overarching decision: Physically a backplane or practically a backplane?

  • Do we want the backplane PCB to physically hold all other boards and they must slot in, or are wire connections OK?

Targets (Maximum/Minimums/Targets):

Pin Count: 

  • More is better, at least 22 at 3A, 34 at 1A

Max Current:

  • See above 

Max Voltage:

  • At least 4S LiPo (17V)

Fabrication Method:

  • Board-independent; connector functionality should not rely on certain mechanical characteristics of the PCB
  • Reversible: connector should not be irreversible or irremovable, in event of damage
  • Requires no specialized, high-cost tools. 
  • Bonus points; ability to act as a wire-to-board connector as well, for use in debugging. 

Mechanical Connection:

  • Keyed; the obvious one
  • Positive latching; IREC compliance, resistance to vibration

Assembly Difficulty:

  1. THC - Through Hole Connector (Easiest)
  2. SMD - Wide Pitch (Not Complicated but requires additional equipment)
  3. SMD - Tight Pitch (Hard - Potential for shorts)

Part Availability: 

Cost (<$5 Per Connector)

Connector Name#PinsMax CurrentMax VoltageFabrication MethodMechanical ConnectionAssembly DifficultyPart AvailabilityBoard ConnectionCostNotesDatasheet/LinkMates with
Molex Microfit2-248ALotsCrimp, PCB MountPlastic LatchingLow-MediumVery High (3rd party equivalents)Through Hole or SMD<$0.1Generic automotive connector. Very sturdy, but take up a lot of board space. Available as WTB, BTB, WTW, Panel, etc.


https://www.molex.com/molex/products/family/microfit_30
Molex EBBI Plug401A30VBoard to Board
LowHigh (digikey)Through Hole$5-$10
https://www.molex.com/molex/products/part-detail/pcb_receptacles/0716607040https://www.molex.com/molex/products/part-detail/pcb_headers/0716612540
2xN Header2xN4A-6A500V
NoneLowVery HighThrough Hole<Generic 0.1" header, very interchangeable and cheap options availablehttps://www.mouser.com/ProductDetail/Samtec/TSW-150-08-S-D-RA?qs=rU5fayqh%252BE3IO3pomHat5g%3D%3D
IDC Header
3A350VCrimpPlastic LatchingLowVery HighThrough Hole<$10Generic 0.1" header, very interchangeable and cheap options availablehttps://www.molex.com/molex/products/part-detail/pcb_headers/0901301240https://www.molex.com/molex/products/part-detail/crimp_housings/0901420040
Samtec ERM8-030-01-L-D-RA-TR10-751.4A225VBoard to BoardNoneMediumMedium (Lots in stock)SMD$10 per
https://www.samtec.com/products/erm8-ra