Wrekin Circuits has a Capability that covers a wide range of Technologies and Market sectors.
We have a wealth of experience regarding R&D programmes to develop new process technologies and products.
Some special features such as heavy copper plating (max 15oz), 50 micron (2 thou) tracks, and differential controlled impedance and blind and buried vias.
Copper / silver fill technology and metal backed PCB’s are a testament to the technical capability of our high technology service orientated company.
Capability is stated in the subsections below but this is a general guide only.
Please contact our Technical Department to discuss your requirements. We actively encourage DFM support for prototyping to maximise yields on production batches.
Data Formats
We can accept all data formats including:
- DXF
- ODB++
- Extended Gerber RS274X (Preferred)
- Standard Gerber RS274D to include aperture lists
- DPF
- HPGL (for drawing)
- Excellon (drill files) SIEB Meyer (drill files)
- IPC-D-356 (netlist files) Mentor (netlist files)
Please contact our technical department should you require DFM support.
What data is required?
- All layers including drill supplied as separate files
- Solder resist – top and bottom
- If applicable, ident, peelable masks and masks for plugging vias.
- Profile drawing with all tolerances stated
- Drill drawing to identify the positions and sizes of the holes.
PCB details
- Build for multilayer’s including material type, thickness and copper weights
- Circuit dimensions
- Panelisation information if not supplied as a single circuit including fiducial and tooling hole requirements
- Release and Quality Standards required e.g. C of C, UL and IPC-A-600 Class 2
- Special requirements e.g. High voltage test, controlled impedance
- Solderable finish e.g. LF HASL, HASL, ENIG, OSP, SILVER & ENEPIG
- Gold plating – e.g. Hard gold, soft gold, including chamfer details for edge connectors
- Solder resist – type e.g. Gloss, semi gloss, matt
- Colour e.g. Green, white, red, blue, clear, yellow, and black
- Silk screen ident – type and colour as above.
PCB Sizes
Maximum Layer Count
| PCB TYPE | LAYER COUNT |
|---|---|
| CONVENTIONAL/PTHS | 2 |
| MULTI-LAYER | 36 |
| FLEX | 2 |
| FLEX RIGID | 2 PLUS RIGID |
| MULTI-LAYER FLEX RIGID | 16 |
Minimum/Maximum Board Thickness
| TYPE | MIN | MAX |
|---|---|---|
| CONV/PTHS | 0.05 mm 0.002 thou |
4.8 mm 0.189 thou |
| MULTI-LAYER | 0.3 mm 0.118 thou |
8.5 mm 0.334 thou |
| FLEX | 0.05 mm 0.002 thou |
0.4 mm 0.016 thou |
| FLEX RIGID | 0.2 mm 0.008 thou |
4.8 mm 0.189 thou |
| MULTI-LAYER FLEX RIGID | 0.2 mm 0.008 thou |
3.2 mm 0.125 thou |
Maximum Board Sizes and Manufacturing Size
| TYPE | CIRCUIT SIZE IN INCHES | CIRCUIT SIZE IN MM | Manufacturing panel size in Inches | Manufacturing panel size in MM |
|---|---|---|---|---|
| CONVENTIONAL | 26.6 X 21.6 | 675 X 548 | 28 X 23 | 711 X 584 |
| PTH | 26.6 X 21.6 | 675 X 548 | 28 X 23 | 711 X 584 |
| MULTI-LAYER FLEX RIGID | 26 X 21 | 660 X 533 | 28 X 23 | 711 X 584 |
Substrates/Materials
Wrekin Circuits manufacture using most materials from cost efficient through to very high speed / low loss applications. These include Standard and High performance FR4’s and Polyimides.
Materials include Arlon, Isola, IMS, EMC, Dupont, Taconic, Rogers, and Ventec.
Standard core thickness:
- 0.1 (mm) (fr4)
- 0.125 (mm) (fr4)
- 0.2 (mm) (fr4)
- 0.25 (mm) (fr4)
- 0.3 (mm) (fr4)
- 0.35 (mm) (fr4)
- 0.4 (mm) (fr4)
- 0.5 (mm) (fr4)
- 0.6 (mm) (fr4)
- 0.711 (mm) (fr4)
- 0.76 (mm) (fr4)
- 0.88 (mm) (fr4)
- 0.910 (mm) (fr4)
- 0.910 (mm) (fr4)
- 1.00 (mm) (fr4)
- 1.08 (mm) (fr4)
- 1.57 (mm) (fr4)
FR4 prepreg codes and thickness:
- 106 – 0.037mm thick
- 1080 – 0.06 mm thick
- 2125 – 0.09 mm thick
- 2113 – 0.1 mm thick
- 2116 – 0.112 mm thick
- 7628 – 0.18 mm thick
Copper weights available:
- 0.25 oz (9 microns)
- 0.33 oz (12 microns)
- 0.50 oz (17.5 microns)
- 1.0 oz (35 microns)
- 2.0 oz (70 microns)
- 3.0 oz (105 microns)
- 4.0 oz (140 microns)
- 5.0 oz (175 microns)
- 6.0 oz (210 micron)
- 7.0 oz (245 micron)
- 8.0 oz (280 micron)
- 9.0 oz (315 micron)
- 10 oz (350 micron)
- 11 oz (385 micron)
- 12 oz (420 micron)
Wrekin Circuits currently produce 15oz copper finish please discuss requirement with our Technical Department.
Holes and Pads
| HOLE SIZE / TOLERANCE | |
|---|---|
| MINIMUM FINISHED HOLE SIZE | 0.05mm / 0.002 thou |
| MAXIMUM DRILLED HOLE SIZE | 6.0mm |
| DRILLED HOLE DIAMETER TOLERANCE | |
| UP TO 1.0mm (0.039 THOU) | +/- 0.025mm / 0.001 thou |
| 1.0mm / 0.039 THOU TO 2.0mm 0.078 THOU | +/- 0.038mm / 0.0015 thou |
| OVER 2.0mm / 0.008 THOU | +/- 0.050mm / 0.002 thou |
| DRILLED HOLES POSITIONAL TOLERANCE | |
| HOLE POSITIONS LOCATED FROM OUTER LAYER ARTWORKS | 0.076mm / 0.003 thou |
| HOLE POSITION FROM CAD DATA | 0.038mm / 0.0015 thou |
| PLATED HOLE DIAMETER TOLERANCE | |
| UP TO 1.0mm 0.004 THOU | +/- 0.050mm / 0.002 thou |
| 1mm / 0.004 THOU TO 2.00mm / 0.078 THOU | +/- 0.076mm / 0.003 thou |
| OVER 2mm / 0.078 THOU | +/- 0.087mm / 0.0035 thou |
| REGISTRATION TOLERANCE ( PAD / HOLE RATIO ) | |
|---|---|
| DRILL POSITION TOLERANCE | +/- 0.038mm / 0.0015 thou |
| PAD POSITION TOLERANCE | +/- 0.025mm / 0.001 thou |
| PHOTO LOCATION TOLERANCE | +/- 0.076mm / 0.003 thou |
| ETCH FACTOR | – 0.013mm / 0.0005 thou |
| MIN. ANNULAR RING REQUIREMENTS | 0.076mm / 0.003 thou |
| TOTAL MANUFACTURE TOLERANCE | 0.216mm / 0.0085 thou |
Outer layers: Ratio for a hole dia. of 1.0mm would then be 1:1.46, i.e. 1.46mm Pad minimum would be required to give land requirement of 0.076mm.
Inner Layers: Ratio for a hole dia. of 1.0mm would be 1:1.42 to achieve tangency.
Layer to Layer registration is dependant upon the accumulation of: Photo-location tolerance
( +/- 0.076mm ) Hard tooling tolerance ( +/- 0.025mm ) and the deviation due to pressing and etching. Pressing and etching deviations are dependant upon material thickness and copper weight per square metre. As a guide therefore, +/- 0.2mm registration tolerance per pair of layers is the capability.
| PLATING TYPE | THICKNESS | PLATING ALLOWANCE |
|---|---|---|
| GOLD PLATING | 2.5 microns +/- 0.25 | +0.10mm (0.004 thou) |
| TIN / LEAD PLATING | 7.5 microns +/- 1.0 | +0.15mm (0.006 thou) |
| NICKEL / GOLD PLATING | 2.5 microns +/- 0.5 | +0.10mm (0.004 thou) |
Tracks and Gaps
Minimum track widths vary with the copper weight being used.
Generally a minimum of 0.1mm clearance is required between the pad and the tracks, and 0.2mm between a hole and the tracks.
DESIGN GUIDELINES
| COPPER | MINIMUM TRACKS | MINIMUM GAPS THOU/(mm) | |
|---|---|---|---|
| THOU/(mm) | INNER | OUTER | |
| 0.25 oz | 3 (0.076) | 3 (0.076) | 3 (0.076) |
| 0.50 oz | 4 (0.102) | 4 (0.102) | 4 (0.102) |
| 1.00 oz | 5 (0.127) | 5 (0.127) | 5 (0.127) |
| 2.00 oz | 8 (0.203) | 8 (0.203) | 6 (0.152) |
| 3.00 oz | 12 (0.304) | 10 (0.254) | 8 (0.203) |
| 4.00 oz | 12 (0.304) | 12 (0.304) | 10 (0.254) |
| 5.00 oz | 12 (0.304) | 14 (0.355) | 12 (0.304) |
| 6.00 oz | 12 (0.304) | 16 (0.406) | 14 (0.355) |
| 7.00 oz | 12 (0.304) | 18 (0.457) | 16 (0.406) |
| 8.00 oz | 12 (0.304) | 20 (0.508) | 18 (0.457) |
| 9.00 oz | 12 (0.304) | 22 (0.559) | 20 (0.508) |
| 10.00 oz | 12 (0.304) | 24 (0.610) | 22 (0.559) |
| 11.00 oz | 12 (0.304) | 26 (0.660) | 24 (0.610) |
| 12.00 oz | 12 (0.304) | 28 (0.711) | 26 (0.660) |
Please discuss high copper weight designs with our Technical Department
Solder Resist
Type – All types available.
Thickness – 25 um over surface patterns.
Colours available – green, red, blue, black, clear, white, yellow.
Finish- Gloss, semi-gloss, matt.
Clearance required on pads 0.05mm.
Component Notation
Notations are applied by either manual screen printing or Ink jet printing (White only).
Minimum line features 0.1mm.
Standard line features 0.2mm.
Colours available – white, yellow, black, blue, red, purple, orange.
Alignment positional tolerance +/- 0.2mm / 0.008 thou.
Note that the designed ident should be a minimum of 0.3mm away from any solderable feature.
Surface Finishes
Solderable Finishes
| SOLDERABLE FINISH | TYPICAL USE | THICKNESS |
|---|---|---|
| HOT AIR SOLDER LEVEL (63/37) | GENERAL PURPOSE | 4 – 40 Um |
| LEAD FREE H.A.S.L (SN100C) | GENERAL PURPOSE | 4 – 40 Um |
| IMMERSION SILVER | FLAT PAD FOR FINE PITCH | 1 – 1.2 Um |
| OSP Small quantities only, laboratory process |
FLAT PAD FOR FINE PITCH | 0.1 – 0.3 Um |
| ENIG (IMMERSION GOLD) | FLAT PAD FOR FINE PITCH | 0.08 – 0.12 Um Au & 3-5 Um NI |
| ENEPIG | WIRE BONDING | 0.03 – 0.07 Um Au, 3 – 6 Um Ni & 0.06 – 0.3 Um Pd |
| ELECTROLYTIC NI/AU | EDGE CONNECTORS KEY PADS, CONTACT PADS |
0.1 – 5.0 Um Au, 1.0 – 10.0 Um Ni |
| CARBON INK | KEY PADS | 10 – 25 Um |
Wrekin circuits offer a wide range of finishes to suit all technologies, applications and assembly methodologies.
They all meet the requirements of RoHS other than HASL 63/37.
Contact Wrekin Circuits Technical Department for further advice.
Test
All PCB’s are 100% tested to data. This includes inner layers pre bonding and final circuit test on completion of production.
Whenever possible please supply an IPC-D-356 Netlist.
Our test departments includes 2off Orbotech Automated Optical Inspection machines (AOI) for inner layer verification and 2off A3 ATG High Voltage Flying Probe Testers for final test.
ATG Capability
Voltage 0-500v
Current 3-30Ma
Measuring range 1 ohm to 1K ohm
0.5 M ohm to 10 M ohm
Test area 520mm x 400mm
Profile
Machine cutting positional and overall size standard tolerances
NC Routing +/- 0.1mm / 0.004 thou
Special tolerance +/- 0.05mm /0.002 thou
Cutting tools available from 0.6mm to 2.4mm (standard)
Depth controlled routing / drilling / milling with positional tolerance +/- 0.2mm
Chamfers of 20,30,35 and 45 degrees available on edge connectors
Scoring