• Double side circuit boards

- FEATURES MANUFACTURE DOUBLE SIDE
- GENERAL TOLERANCES

In order to classify the printed circuits’ difficulty we use the following parameters:

- CLASS
Is the dimensional characteristics set of the different elements that compose the printed circuit board image.

- RING CHECK
Makes reference to the copper ring between the hole and its pad. This parameter will determine the difficulty of trim between the hole and the image of the circuit.

- TOLERANCES
Made reference to the tolerance level of the different processes and materials.

The total of these 3 concepts will define the manufacture difficulty and therefore the price of the circuit.

PARAMETERS MANUFACTURE DOUBLE SIDE

		CLASS3	CLASS 4	CLASS 5	CLASS 6	CLASS 7
Minimum plated through hole diameter		20 mil	12 mil	12 mil	8 mil	6 mil
Minimum non plated through hole diameter		24 mil	16 mil	16 mil	12 mil	10 mil
Aspect/Ratio		5	5	6	8	13 (maximum thickness 2 mm)
Minimum trace/spacing width		12 mil (½ oz ) 12 mil (1 oz ) 14 mil (2 oz )	8 mil (½ oz ) 8 mil (1 oz ) 10 mil (2 oz )	6 mil (½ oz ) 6 mil (1 oz ) 8 mil (2 oz )	5 mil (½ oz ) 6 mil (1 oz ) 7 mil (2 oz )	4 mil (½ oz )
Minimum annular ring		9 mil	7 mil	5 mil	4 mil	3 mils

MULTILAYER GENERAL TOLERANCES

		STANDARD	SPECIAL
Outer layer trace/spacing width		±20% (½ oz ) ±25% (1-2 oz )	±10% (½ oz ) ±15% (1 - 2 oz)
Inner layer trace/spacing width		±20% (½ - 1 oz) ±25% (2 oz)	±10% (½ oz ) ±15% (1 - 2 oz )
Plated hole diameter		+4 mil / -2 mil (or equivalent)	+4 mil / -0,0 mil ±2 mil
Non plated hole diameter		+4 mil / -0,0 mil (or equivalent)	±1.4 mil (or equivalent)
Scoring to copper clearance		Min. 40 mil.	Min. 30 mil
Scoring positioning		± 4 mil	± 3 mil
Scoring remaining thickness		± 4 mil	± 2 mil
Board size		± 6 mil.	± 4 mil.
Total thickness tolerance		±10 %	±5 %
Dielectric thickness		±10 %	±5 %
Finished plated hole copper thickness		Average: 0.7 oz Minimum: 0.6 oz	Average: 1 oz Minimum: 0.86 oz
Blind/buried plated hole copper thickness		Average: 0.4 oz. Minimum: 0.37 oz.	Average : 0.7 oz. Minimum: 0.6 oz.
Microvia Plated hole copper thickness		Mitja: 0.4 oz. Mínim:0.37 oz.	Mitja: 0.7 oz. Mínim: 0.6 oz.
Mínimum wall between same net plated through holes		12 mil.	10 mil.
Minimum wall between different net plated through holes		16 mil.	14 mil.
Minimum wall between non plated thruough holes		10 mil.	8 mil.
Minimum annular ring non plated hole		10 mil.	8 mil.
Track to non plated through hole minimum spacing		8 mil.	6 mil.
Track to board edge minimum spacing		8 mil.	6 mil.
Offset between board edge and drill		Max. 6 mil.	Max. 4 mil.
Offset between drill to outlayer pad		Max. 4 mil.	Max. 3 mil.
Offset between drill to innerlayer pad		Max. 6 mil.	Max. 5 mil.
Offset between layers		Max. 4 mil.	Max. 3 mil.
Soldermask feature tolerance		Max. 6 mil.	Max. 3 mil.
Soldermask min Dam size		3 mil.	-
Photoimageable soldermask clearance		3 mil.	-
Silkscreened soldermask clearance		8 mil.	6 mil.
Legend minimum line		5 mil.	4 mil.
Conductive ink (graphite) overlapping		8 mil.	5 mil.
Conductive ink (graphite) spacing		20 mil.	16 mil.
Conductive ink to pad spacing		16 mil.	12 mil.
Peel-off mask overlapping		40 mil.	28 mil.
Peel-off mask to pad spacing		40 mil.	28 mil.
Peel-off mask to board edge spacing		40 mil.	28 mil.
Maximum peel-off mask filled hole		71 mil.	79 mil.
Bow and twist		Maxim 1%	Maxim 0,5 %
Insulation resistance		Minimum 0,5 MOhm	Minimum 2,0 MOhm
Continuity		Maxim 10 Ohms	-
Electrical strenght		750 V/mil (30 V/µm.) segons MIL-13949 H	-
Ionic contamination		Max. 1µg Eq. CINa/cm2	Max. 0,8 µg Eq. CINa/cm2
Other features		See spec. IPC-A-600 Rev.E 8-95	-