Capabilities

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 24oz), 50 micron (2 thou) tracks, and differential controlled impedance and blind and buried vias.

Copper fill technology and metal backed PCBs 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.

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Close-up of a red printed circuit board with multiple holes and copper pads.

Data Formats

PCB Sizes

Substrates/Materials

Holes and Pads

Tracks and Gaps

Solder Resist

Surface Finishes

Test

Profile

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.

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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, 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.

Maximum Layer Count

PCB TYPE: CONVENTIONAL/PTHS
LAYER COUNT: 2
PCB TYPE: MULTI-LAYER
LAYER COUNT: 36
PCB TYPE: FLEX
LAYER COUNT: 2
PCB TYPE: FLEX RIGID
LAYER COUNT: 2 PLUS RIGID
PCB TYPE: MULTI-LAYER FLEX RIGID
LAYER COUNT: 16

Minimum/Maximum Board Thickness

TYPE: CONV/PTHS
MIN:0.05 mm / 0.002 thou
MAX: 4.8 mm / 0.189 tho
TYPE: MULTI-LAYER
MIN: 0.3 mm / 0.118 thou
MAX: 8.5 mm / 0.334 thou
TYPE: FLEX
MIN:0.05 mm / 0.002 thou
MAX: 0.4 mm / 0.016 thou
TYPE: FLEX RIGID
MIN: 0.2 mm / 0.008 thou
MAX: 4.8 mm / 0.189 thou
TYPE: MULTI-LAYER FLEX RIGID
MIN: 0.2 mm / 0.008 thou
MAX: 3.2 mm / 0.125 thou

Maximum Board Sizes and Manufacturing Size

TYPE: CONVENTIONAL
CIRCUIT SIZE IN INCHES: 26 X 21
CIRCUIT SIZE IN MM: 660 X 533
Manufacturing panel size in Inches: 28 X 23
Manufacturing panel size in MM: 711 X 584
TYPE: PTH
CIRCUIT SIZE IN INCHES: 26 X 21
CIRCUIT SIZE IN MM: 660 X 533
Manufacturing panel size in Inches: 28 X 23
Manufacturing panel size in MM: 711 X 584
TYPE: MULTI-LAYER FLEX RIGID
CIRCUIT SIZE IN INCHES: 26 X 21
CIRCUIT SIZE IN MM: 660 X 533
Manufacturing panel size in Inches: 28 X 23
Manufacturing panel size in MM: 711 X 584

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)
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 µm)
0.33 oz (12 µm)
0.50 oz (17.5 µm)
oz (35 µm)
2.0 oz (70 µm)
3.0 oz (105 µm)
4.0 oz (140 µm)
5.0 oz (175 µm)
6.0 oz (210 µm)
7.0 oz (245 µm)
8.0 oz (280 µm)
9.0 oz (315 µm)
10 oz (350 µm)
11 oz (385 µm)
12 oz (420 µm)
13 oz (455 µm)
14 oz (490 µm)
15 oz (525 µm)
16 oz (560 µm)
17 oz (595 µm)
18 oz (630 µm)
19 oz (665 µm)
20 oz (700 µm)
21 oz (735 µm)
22 oz (770 µm)
23 oz (805 µm)
24 oz (840 µm)

Wrekin Circuits currently produce 24oz copper finish please discuss requirement with our Technical Department.

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 THO = +/- 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
GOLD PLATING
THICKNESS
2.5 microns+/- 0.25
PLATING ALLOWANCE
+0.10mm (0.004 thou)

PLATING TYPE
TIN / LEAD PLATING
THICKNESS
7.5 microns +/- 1.0
PLATING ALLOWANCE
+0.15mm (0.006 thou)

PLATING TYPE
NICKEL / GOLD PLATING
THICKNESS
2.5 microns +/- 0.5
PLATING ALLOWANCE
+0.10mm (0.004 thou)

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 Thou/(mm)	Minimum Gaps Thou/(mm)
Copper	Minimum Tracks 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)

Copper: 0.25 oz
Minimum Tracks	3 (0.076)
Minimum Gaps (Inner)	3 (0.076)
Minimum Gaps (Outer)	3 (0.076)

Copper: 0.50 oz
Minimum Tracks	4 (0.102)
Minimum Gaps (Inner)	4 (0.102)
Minimum Gaps (Outer)	4 (0.102)

Copper: 1.00 oz
Minimum Tracks	5 (0.127)
Minimum Gaps (Inner)	5 (0.127)
Minimum Gaps (Outer)	5 (0.127)

Copper: 2.00 oz
Minimum Tracks	8 (0.203)
Minimum Gaps (Inner)	8 (0.203)
Minimum Gaps (Outer)	6 (0.152)

Copper: 3.00 oz
Minimum Tracks	12 (0.304)
Minimum Gaps (Inner)	10 (0.254)
Minimum Gaps (Outer)	8 (0.203)

Copper: 4.00 oz
Minimum Tracks	12 (0.304)
Minimum Gaps (Inner)	12 (0.304)
Minimum Gaps (Outer)	10 (0.254)

Copper: 5.00 oz
Minimum Tracks	12 (0.304)
Minimum Gaps (Inner)	14 (0.355)
Minimum Gaps (Outer)	12 (0.304)

Copper: 6.00 oz
Minimum Tracks	12 (0.304)
Minimum Gaps (Inner)	16 (0.406)
Minimum Gaps (Outer)	14 (0.355)

Copper: 7.00 oz
Minimum Tracks	12 (0.304)
Minimum Gaps (Inner)	18 (0.457)
Minimum Gaps (Outer)	16 (0.406)

Copper: 8.00 oz
Minimum Tracks	12 (0.304)
Minimum Gaps (Inner)	20 (0.508)
Minimum Gaps (Outer)	18 (0.457)

Copper: 9.00 oz
Minimum Tracks	12 (0.304)
Minimum Gaps (Inner)	22 (0.559)
Minimum Gaps (Outer)	20 (0.508)

Copper: 10.00 oz
Minimum Tracks	12 (0.304)
Minimum Gaps (Inner)	24 (0.610)
Minimum Gaps (Outer)	22 (0.559)

Copper: 11.00 oz
Minimum Tracks	12 (0.304)
Minimum Gaps (Inner)	26 (0.660)
Minimum Gaps (Outer)	24 (0.610)

Copper: 12.00 oz
Minimum Tracks	12 (0.304)
Minimum Gaps (Inner)	28 (0.711)
Minimum Gaps (Outer)	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.

Solderable Finishes

Solderable Finish	Typical Use	Thickness
Hot Air Solder Level (63/37)	General Purpose	4 – 40 µm
Lead Free H.A.S.L (SN100C)	General Purpose	4 – 40 µm
Immersion Silver	Flat Pad for Fine Pitch	1 – 1.2 µm
ENIG (Immersion Gold)	Flat Pad for Fine Pitch	0.08 – 0.12 µm Au & 3–5 µm Ni
ENEPIG	Wire Bonding	0.03 – 0.07 µm Au, 3–6 µm Ni & 0.06 – 0.3 µm Pd
Electrolytic Ni/Au	Edge Connectors, Key Pads, Contact Pads	0.1 – 5.0 µm Au, 1.0 – 10.0 µm Ni
Carbon Ink	Key Pads	10 – 25 µm

Solderable Finish: Hot Air Solder Level (63/37)
Typical Use	General Purpose
Thickness	4 – 40 µm

Solderable Finish: Lead Free H.A.S.L (SN100C)
Typical Use	General Purpose
Thickness	4 – 40 µm

Solderable Finish: Immersion Silver
Typical Use	Flat Pad for Fine Pitch
Thickness	1 – 1.2 µm

Solderable Finish: ENIG (Immersion Gold)
Typical Use	Flat Pad for Fine Pitch
Thickness	0.08 – 0.12 µm Au & 3–5 µm Ni

Solderable Finish: ENEPIG
Typical Use	Wire Bonding
Thickness	0.03 – 0.07 µm Au, 3–6 µm Ni & 0.06 – 0.3 µm Pd

Solderable Finish: Electrolytic Ni/Au
Typical Use	Edge Connectors, Key Pads, Contact Pads
Thickness	0.1 – 5.0 µm Au, 1.0 – 10.0 µm Ni

Solderable Finish: Carbon Ink
Typical Use	Key Pads
Thickness	10 – 25 µm

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.

All PCBs 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 include 3 x Orbotech Automated Optical Inspection machines (AOI) for inner layer verification, 2 x A3 and 1 x A5 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

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