Base materials and their specific parameters.
Thicknesses and Tolerances of Materials
Thicknesses and Tolerances of Materials
The thickness of the whole PCB is defined as follows (definition according to Perfag):
a) Base material including copper foil
b) in case of a finished PCB: on an etched spot, whereby the solder stop mask must be deducted and added to the nominal thickness of the Cu-foil.
| Material | Type | Thickness | Tolerance |
|---|---|---|---|
| FR 4 (Thickness with Cu) |
Standard |
0.80 mm 1.00 mm 1.20 mm 1.55 mm 2.00 mm 2.40 mm |
+/- 0.10 mm +/- 0.13 mm +/- 0.13 mm +/- 0.075 mm +/- 0.18 mm +/- 0.23 mm |
| Inner layer (extract) (Thickness with Cu) |
1 x 2116 1 x 2157 1 x 7628M 2 x 2157 2 x 7628M 2 x 7628M 7628/2125/7628 3 x 7628 3 x 7628M 3 x 7628M 4 x 7628M 4 x 7628M 5 x 7628M 6 x 7628M |
0.10 mm 0.15 mm 0.20 mm 0.30 mm 0.36 mm 0.41 mm 0.46 mm 0.51 mm 0.56 mm 0.61 mm 0.71 mm 0.76 mm 1.00 mm 1.20 mm |
+/- 0.013 mm +/- 0.018 mm +/- 0.025 mm +/- 0.038 mm +/- 0.038 mm +/- 0.038 mm +/- 0.038 mm +/- 0.050 mm +/- 0.050 mm +/- 0.050 mm +/- 0.050 mm +/- 0.050 mm +/- 0.075 mm +/- 0.075 mm |
| Prepregs | 106 1080 2125 2116 2165 7628 |
0.048 mm 0.069 mm 0.099 mm 0.109 mm 0.130 mm 0.178 mm |
+/- 0.005 mm +/- 0.008 mm +/- 0.008 mm +/- 0.008 mm +/- 0.008 mm +/- 0.008 mm |
Copper Thickness / PCB Thickness / Maximum PCB Size
Copper Thickness / PCB Thickness / Maximum PCB Size
We offer the following frame conditions for your production:
| Surface Copper: | 35 µm to 210 µm |
| Inner layers: | Up to 400 µm |
| Outer layers: | Up to 210 µm |
|
Possible PCB thickness from: |
0,80 mm to 2,40 mm (other thickness on demand) |
| Largest double-sided PCB: | 590 x 514 mm |
| Largest mulitlayer PCB: | 570 x 490 mm |
| Torsion and waping: < 0,80 mm PCB thickness: 0.80 mm – 1,50 mm PCB thickness: 1.50 mm – 3,20 mm PCB thickness: Prerequisite: The conductive pattern is identical on both sides. |
≤ 1.5 % ≤ 1.0 % ≤ 0.5 |
Structures of the PCBs
Structures of the PCBs
Für das Leiterbild sind in Abhängigkeit von der Kupferstärke folgende Strukturen möglich:
| 18 µm base copper: | Inner layers ≥ 100µm Outer layers > 80 µm |
| 35 µm base copper: | Inner layers ≥ 120 µm Outer layers > 150 µm |
| 70 µm base copper: | Inner layers ≥ 200 µm Outer layers > 200 µm |
| 140 µm base copper: | Inner layers ≥ 350 µm Outer layers > 350 µm |
| Smallest final drill diameter: | ≤ 0.10 mm |
| Aspect ratio: | 1:8 |
| Drilling spacing: (mounting holes) |
< +/- 80 µm |
| Spacing of printing circuit to mounting holes: | < +/- 80 µm |
Solder Resists and other Prints
Solder Resists and other Prints
For the various fields of applications, we generally use halogen-free solder resists. Our classic standard coating is the green XV501 HF produced by the company “Coates” which is casted on the PCB. In case of other coatings and colours we use a silk-screen printing method.
| Tolerances luminous exposure: | ≤ 50 µm |
| Bridges between the SMD-pads depending on the final surface: |
≥ 80 µm |
| In addition, we offer: | - Beschriftungsdruck - Abziehlack - Carbondruck mit Schichtdicken ≥ 15 µm |
| Plugging of PCBs with filling print without elevations: |
bis 0.60 mm |
| Colours: | Green (standard) White, yellow, red, blue, black (matt and glossy) |
Mechanical Treatment / Contours
Mechanical Treatment / Contours
Dependant on the production specification, you have the choice between the following finishes:
- Milling of all radii
- Scoring
- Punching
- Countersink drilling with a depth tolerance of 50 µm
- Deep milling
Surface finishes of the PCB
Surface finishes of the PCB
The choice of the material of the surface finish depends on the PCB layout, on the number of soldering points and on the holding times between the individual soldering processes.
At technoboards KRONACH, various surface finishes for the PCBs are available:
- traditional HAL
- HAL lead-free
- chemical Ni / Au
- chemical Sn
- Entek (organic surface)
- chemical Ag (on demand)
- galvanised Ni / Au (e.g. for contact plugs)
- Bond gold for aluminium wire bonding
HAL lead-free
HAL lead-free
HAL lead-free is not suitable for all layouts, as it not as planar as e.g. HAL with lead. In addition it is more difficult to cover pad surfaces on a large scale with it and it may lead to defective spots.
Galvanic gold with HAL lead-free is currently not possible.
Bond gold
Bond gold
The width and length of the connection surface depends on the diameter of the wire which is used. For each individual wire, the minimum width of the pad should have the triple wire diameter, and the minimum length should have the six fold wire diameter.
The bond surface consists of chemical Ni 4 – 9 µm and chemical Au 0.1 ± 0.05 µm. The phosphorus concentration in the nickel is ≤ 10%.
The finish roughness is Rz ≤ 3 µm Rt ≤ 4 µm Ra ≤ 0.5 µm. Bond boards are never delivered without intermediate paper layers.