Identification
	Part number:		MARBLEWALRUS backplane v0.1 BUDGETARY QUOTE
	Design engineer:	Andrew D. Zonenberg 
						azonenberg@drawersteak.com

General fabrication notes

	Boards should be individually routed. Total order is six units, or MOQ if this is more than six.

	Lot number / date codes should be placed on the bottom side of the board.

	Blue LPI solder mask on both sides of board. Mask clearance 50 μm around all NSMD pads.
	
	White LPI legend on both sides of board. Resolution should be sufficient to ensure readability of the smallest text.
	
	Pad finish is ENIG.

	Core/prepreg thickness may be adjusted as needed to obtain 1.6 mm finished thickness and target impedances.
	
Impedances

	Control to within 10%.

	Layer 1 microstrip (ref to layer 2 ground)
		123 μm = 50 ohm
		110 μm = 100 ohm differential

	Layer 4 microstrip (ref to layer 3 ground)
		123 μm = 50 ohm
		110 μm = 100 ohm differential
		
Design rules

	Minimum trace/space
		125 μm clearance / 110 μm trace

	Minimum through-board via
		500 μm pad, 250 μm drill

Stackup

	1	35 μm (1 oz) copper		Signal
		90 μm prepreg
	2	35 μm (1 oz) copper		Ground
		1.28 mm core
	3	35 μm (1 oz) copper		Power/Ground
		90 μm prepreg
	4	35 μm (1 oz) copper		Signal with ground fill

File naming
	marblewalrus-backplane.d356					IPC D-356 electrical test netlist
	marblewalrus-backplane-Edge_Cuts.gbr		Board outline
	marblewalrus-backplane.drl					Through-board plated holes
	marblewalrus-backplane-F_Paste.gbr			Front solder paste
	marblewalrus-backplane-F_SilkS.gbr			Front silkscreen
	marblewalrus-backplane-F_Mask.gbr			Front solder mask
	marblewalrus-backplane-F_Cu.gbr				Layer 1 (front) copper
	marblewalrus-backplane-In1_Cu.gbr			Layer 2 copper
	marblewalrus-backplane-In2_Cu.gbr			Layer 3 copper
	marblewalrus-backplane-B_Cu.gbr				Layer 4 (back) copper
	marblewalrus-backplane-B_Mask.gbr			Back solder mask
	marblewalrus-backplane-B_SilkS.gbr			Back silkscreen
	marblewalrus-backplane-B_Paste.gbr			Back solder paste