PCB pooling, i.e. combining different printed circuit board (PCB) designs on a single, large panel is an economical way for producing single boards or small production runs for several clients in one go. However, to allow PCB design data from different clients to pass together through the same production process they must all conform to the same set of manufacturing rules.

To ensure this is the case the manufacturer analyses the board data and adapts or corrects it where needed. What is done to the data and how depends on the manufacturer, in this article we will show you the Eurocircuits’ way.

A three-stage process

At Eurocircuits your board’s design data has to jump successfully through three hoops before its production is actually launched:
  1. Data analysis
  2. Single image preparation
  3. Panelization

PCB design data analysis

First some basic questions must be answered:
  • Is the data in a supported format?
  • Is it complete?
  • Did the client provide special instructions?

Then the data is analysed in more detail:
  • Are all the apertures defined?
  • Are all the holes/drills defined?
  • No zero-sized elements?
PCB design data with zero aperture elements
Zero aperture traces (white) must be corrected.
(Source: Eurocircuits)

Eurocircuits then converts the PCB design data to their internal data format (Ucamco’s UCAM Dynamic Process Format or DPF) because:
  1. Gerber and Excellon files cannot contain all the information required for production
  2. Both file types come in many flavours and therefore must be standardized first.

Looking for trouble

Once the data is in a standard format, it is checked against the design rules for the requested board technology and also against the customer’s order. Other checks at this point include layer consistency (do all the layers have the same holes in the same places?) and copper distribution. Outer and inner layer annular ring (OAR & IAR) violations will be found, together with inter-track and track-to-pad isolation problems and minimum track width exceptions.

Outer annular ring
The outer annular ring (OAR) must allow
for limited drill precision.

Eurocircuits analyses any problems that were found to see if they can fix them for you. An exception is raised if repair is not possible without your intervention or when there are too many problems. Exceptions must be cleared before data processing can continue.