Twelve Layer Immersion Gold Board With Edge Connector Fingers
A twelve layer FR4 board with immersion gold and a gold finger edge connector. Twelve layers is the density used for backplanes, plug-in processor cards and boards that carry several high speed buses alongside multiple supply rails.
What This Board Is
The board photographed is a plug-in card. It has an edge connector along one side, several large device sites and the kind of routing density that only appears above ten layers. Boards at this count need the whole process chain to be under control at once, because a registration error on any inner layer scraps the panel after lamination.
Sequential lamination, then routing on CNC routers with an outline tolerance of 0.10 mm.
- Rigid PCB
- 12 layer
- Immersion gold
- RoHS
What You Get From This Build
- Twelve layers carry several independent high speed buses without crosstalk between them
- Enough plane layers for each supply rail plus dedicated analogue and digital grounds
- Immersion gold keeps the edge connector and every fine pitch pad on one consistent finish
- Our published layer range runs to 16 layers, so a board can grow without changing supplier
Who Specifies This Board
- Backplane and plug-in card manufacturers
- Networking hardware builders with multiple serial interfaces
- Computing and embedded module makers using high pin count processors
- Engineering teams that have outgrown a ten layer stack-up
Four Failures This Build Is Designed Against
Each one is a real way this class of board goes wrong, and the tolerance or process decision that prevents it.
Inner layer misalignment discovered after lamination
Every inner layer on a twelve layer board must land within ±0.05 mm of hole position, or the panel is scrap. That tolerance is verified rather than assumed.
Buses interfering with each other
A high layer count lets each bus sit between reference planes instead of running alongside unrelated signals.
Edge fingers that degrade in service
Immersion gold suits boards that are seated once. If the card will be removed and re-seated often, ask us about the plated gold process we use on the 8 layer board instead.
Delamination during assembly reflow
The laminate is 94V-0 rated, and warpage across the panel is held at 0.75% or better before the board ever reaches your oven.
Technical Specification
Product detail from the catalogue record, followed by the published process capability for the Rigid PCB family. Anything the legacy catalogue did not record is marked TBC rather than filled in.
| Item | Technical specification |
|---|---|
| Product name | 12 Layer Rigid PCB |
| Legacy catalogue reference | 12 Layer |
| Product family | Rigid PCB |
| Layer count | 12 layer |
| Surface finish | Immersion gold |
| RoHS | RoHS compliant process, as recorded on the legacy catalogue |
| Layer count | 1 to 16 layers |
| Maximum panel dimension | 450 x 660 mm (18 x 26 in) |
| Minimum board thickness | 4 layers 0.40 mm (16 mil) / 6 layers 1.00 mm (40 mil) / 8 layers 1.20 mm (48 mil) |
| Minimum trace width | 0.075 mm (3 mil) |
| Minimum trace space | 0.075 mm (3 mil) |
| Minimum finished hole | 0.20 mm (8 mil) |
| Plated hole wall thickness | 0.025 mm (1 mil) |
| Plated hole diameter tolerance | ±0.075 mm (3 mil) |
| Non-plated hole diameter tolerance | ±0.05 mm (2 mil) |
| Hole position tolerance | ±0.05 mm (2 mil) |
| Outline dimension tolerance | ±0.10 mm (4 mil) |
| Minimum solder bridge | 0.10 mm (4 mil) |
| Warpage | ≤0.75% |
| Isolation resistance | >1012 Ω at normal condition |
| Hole resistance | <300 Ω at normal condition |
| Flammability rating | 94V-0 self-extinguishing |
| Open / short test voltage | 50 to 300 V |
What The Board Is Made Of
| Material | Specification |
|---|---|
| Base laminate | FR4 glass reinforced epoxy, 94V-0 self-extinguishing |
| Copper | Weight confirmed against the current your rails carry |
| Solder mask | LPI solder mask, green as standard, other colours on request |
| Legend | Silk screen legend ink, white as standard |
| Surface finish | Lead-free HASL, immersion nickel gold or electroplated nickel gold |
What Can Be Changed
- Layer count from 1 to 16
- Solder mask colour including blue and other colours
- Legend colour
- Lead-free HASL, immersion gold or electroplated gold
- Copper weight to suit the current your rails carry
- Delivery as singles, V-cut arrays or routed tab arrays
How This Board Is Made
Eight stages on equipment sourced from the USA, Japan, Germany and Israel. Every stage listed runs inside our own plant.
Film and tooling
Artwork plotted on a Mania 8850-P film plotter and the panel laid out for the order quantity.
Inner layers
Imaged, etched and checked before lamination, because a defect buried in the stack cannot be repaired.
Lamination
Cores and prepreg pressed on the MLB laminator to build the stack-up.
Drilling
Mania, Hitachi and domestic CNC drillers, thirteen machines in total, to a 0.20 mm minimum hole.
Plating
Desmear, automatic PTH line and graphic plating to a 0.025 mm barrel wall.
Mask and legend
Automatic screen printing and roller coating, then exposure and developing.
Surface finish
Lead-free HASL, immersion gold or electroplated gold according to the order.
Profile and test
CNC routing or V-cut to ±0.10 mm, then open and short testing at 50 to 300 V.
What Is Checked Before It Ships
- Inner layer inspection before lamination, because buried defects cannot be repaired
- Open and short testing at 50 to 300 V on every board
- Hole resistance verified below 300 Ω at normal condition
- Isolation resistance verified above 1012 Ω at normal condition
- Warpage held at ≤0.75% across the panel
What The Plant Holds
- ISO 9001:2000. Quality management system certification recorded by the company. Current revision year available on request.
- ISO 14001:1996. Environmental management system certification recorded by the company.
- UL. Certification recorded by the company. File number available on request.
- RoHS and lead free. Listed in the company environmental policy alongside pollution prevention and resource reduction.
Certificate numbers, issue dates and current revision years are not published on the legacy site. Ask for copies with your enquiry and they will be sent with the quotation.
How It Compares With The Alternatives
Three boards from our own catalogue, side by side, so the trade-off is visible rather than argued.
| Board | Layers or build | Finish | Best suited to |
|---|---|---|---|
| 12 Layer Rigid PCB | 12 | Immersion gold | Backplanes and high pin count plug-in cards |
| 10 Layer Rigid PCB | 10 | Immersion gold | Multi-BGA boards one step below backplane density |
| 8 Layer Rigid PCB | 8 | Gold plating | Boards whose edge fingers are mated repeatedly |
What To Send With Your Enquiry
Four things that decide whether the quote comes back right the first time.
- Send the impedance profile for every controlled net, not just the fastest one.
- Give the edge connector drawing including finger pitch, length and any chamfer.
- Confirm the finished board thickness the connector slot expects.
- Tell us the panel format you want so that we can plan lamination and routing together.
12 Layer Rigid PCB Questions
Is twelve layers your maximum?
No. Our published rigid capacity covers 1 to 16 layers.
What outline tolerance can you hold on a card that must fit a slot?
±0.10 mm, which is 4 mil, on outline dimensions, and ±0.05 mm on hole position.
Can you build this with a mix of blind and through vias?
Send the via structure with the stack-up and we will confirm what the sequential lamination route supports before quoting.
What test do you run before shipping?
Open and short testing at 50 to 300 V, plus hole resistance and isolation resistance checks.
Other Boards In The Rigid PCB Family
Boards built on the same line, with the same tolerances, in a different configuration.
Double Sided FR4 Board With Lead Free HASL
Four Layer Immersion Gold Board For Dense SMD Routing
Six Layer Board With Lead Free HASL For Larger Controllers
Eight Layer Board With Electroplated Gold For Contact Surfaces
Where This Board Is Used
The fields the legacy catalogue records for this class of board.
This Board In Context
Get 12 Layer Rigid PCB Priced Against Your Own Files
Send Gerber RS-274X with an NC drill file, or an ODB++ package, with the layer count, thickness, copper weight, surface finish and quantity. We check it against the published capability before quoting.