HDI Microvia Design Rules stacked microvia microvia (for impedance controlled PCBs) pad ø 300 μm pad ø 325 µm final ø 100 μm dielectric thickness 58 – 70 μm fin a l ø 100 μm Cu – filled up to max. 4 layer dielectric thickness 85 – 110 μm outer layer layout standard – microvia distance pad / track pad ø 550 μm track width final ø 200/250 μm 100 μm 100 μm distance track / track 100 μm dielectric thickness 58 – 70 μm (layer 1-2) dielectric thickness 55 – 68 μm (layer 2-3) microvia aspect ratio = 1 : 0.8 (diameter / depth) core material core material prepreg Buried Via prepreg PTH 100 μm 100 μm microvias layer 1 to 3 pitch soldermask clearance 50 - 65 µm 400 μm track width 100 / 125 µm max. 55 μm max. 18 μm max. 50 μm BGA Pad ø 350 µm m μm inner layer distance track / track0.75 100 mm Pitch end ø 125 μm pitch pad ø 350 μm staggered microvias inner layer clearance ø 550 μm final ø 200/250 μm 300 μm pad ø 550 μm inner layer pad ø 550 μm distance pad / pad inner layer track width distance pad / track 100 μm inner layer BGA 0.75 mm Pitch BGA 0.65 mm Pitch Var. 2 0.65 mm Pitch 35 µm solder mask clearance Var. 3 soldermask clearance 50 - 65 µm Var. 1 BGA Solder Pad 100 μm inner layer inner layer layout (up to 35 μm Cu thickness) BGA 0.80 mm Pitch Var. 1 100 μm Var. 2 max. 400 µm Soldermask Clearance 50 µm Via Pad Size BGA Area 500 µm ø 275 µm solder pad track width 100 / 125 µm Var. 3 max. 500 µm ≥ 50 µm 50 µm Microvia Pad Outer Layers - 300 / 350 µm 300 / 350 µm Microvia Pad Inner Layers - 300 / 350 µm 300 / 350 µm Track Width / Spacing Outer Layers ≥ 100 µm ≥ 100 µm ≥ 100 µm Track Width / Spacing Inner Layers ≥ 100 µm ≥ 100 µm ≥ 100 µm BGA 0.50 mm Pitch BGA Pad ø 350 µm m BGA Pad ø 350 track width 90 / 100 µm soldermask clearance 50 µm 0.75 mm Pitch QFP 0.40 mm Pitch BGA 0.40 mm Pitch soldermask web ≥ 70 µm Blue = outer layer Green = solder mask Red = layer 2 Black = layer 3 Violet = layer 4 35 µm solder mask clearance ø 275 µm solder pad 100 µm track width soldermask clearance 62/50 µm Pad ø 300 µm Var.1: Via in Pad Var. 2: Dogbone solder pad µVia pad on layer 1 ø 300 µm µVia pad on layer 2 Var. 3: Via in Pad 0.65 mm Pitch BGA Solder Pad Soldermask Clearance Var. 1 Var. 2 Var. 3 300 - 330 µm 240 µm 275 µm 50 µm 40 µm 35 µm Microvia Pad Outer Layers ≥ 300 µm 275 µm 275 µm Microvia Pad Inner Layers 275 µm 275 µm 275 µm Track Width / Spacing Outer Layers ≥ 100 µm 80 / 90 µm 75 µm Track Width / Spacing Inner Layers 75 µm 75 µm 75 µm ø 300 µm µVia pad on layer 3 ø 300 µm µVia pad on layer 4 solder pad 200 µm Blue = outer layer Green = solder mask Red = layer 2 Black = layer 3 Violet = layer 4 0.40 mm Pitch BGA Pad ø 350 track width 90 / 100 µm soldermask clearance 50 µm www.we-online.com Version 1.1