Reverse Engineering

Introduction

Here it describes the sequence of operation of reconstructing a complete Project Database.

The number of steps required to reconstruct a complete project database is determined by the complexity, structure and contents of imported graphic files. Most complete and successful reconstruction can be achieved using full set of artworks in Gerber ASCII format because of their straightforward connection to PCB layout. Import of DXF files are provided mainly for reconstruction of geometrically complicated board outlines. Much depends on purpose of reconstruction. In many cases imported data will allow after edition to generate revised set of artworks without necessity of reconstructing complete Project Database.

Note: No net-list or schematics information will be there but so created simple PCB layout database allows generating revised set of artworks in Gerber ASCII format as well as NC Drill output.

Here are a few examples where graphics imports may be used

1. Complicated PCB outline with or without cutouts have been drawn using AutoCAD. Resulting graphics can be imported and used to reconstruct same PCB outline in the Project Database.
2. User has old Gerber ASCII files for a PCB that requires changes in the artwork(s) these files can be imported and updated to obtain new corrected set of artworks.
3. User has old Gerber ASCII files for a PCB but needs matching NC Drill data. The files can be imported. Graphic Import Editor has tools that allow reconstruction of drilling data.

• component layer
• solder layer
• component print and
• Solder mask

The via position and thru pad position need to take input from the solder masks layer only in which the Dcode filter should be applied as per the via and pad requirements. The via pads and thru pads require information from all the layers except component print

Obtain the required gerber files and for the import process, select Fabrication manager -> File -> Gerber/ Excellon /DXF/ HPGL Viewer. A file import dialog box will be open to import files as shown below. Select the Files of type as Gerber ASCII files (*.GBR). Select the required gerber file. Fig : 1

Click open in the above in the above window top open the Import Parameters dialog as below in Fig: 2

Select the appropriate layer for the layer which is selected for importing. Here Artwork Top layer is selected. Fig: 3

Note: For Multi layer PCB inner layers can be added by clicking “Add inner Layer” in Layer tool Bar (Fabrication Graphic viewer and import editor)

Click Accept so that the changes are effected in the Fabrication Manager. In Fabrication Manager, the board appears as a template.

Reconstruction of Project

Reconstruct board outline

Board outline may be reconstructed automatically by pointing one of the elements in the polygon. Other way of reconstruction is by dragging selected vertex of already existing outline and anchoring it on selected element in the reconstruction template.

Select the vertex of already existing outline and anchor it on the selected element in the reconstruction template. This action immediately replaces the reconstruction template which is the final board.

Reconstructing Components

Before reconstructing the components, select Fabrication Manager -> Tools -> Graphic imports-> Select the Active category as Thrupads Position-> Create graphic item (Second function tool) -> Assign Holes (F2) , Give the required Hole diameter (eg : .0350”) , with some hole category. Fig:8

Then select Fabrication Manager -> Tools -> Reconstruct from graphics -> Reconstruct components -> Reconstruct components/ Packages from graphics (F1) -> Block select the required component -> Select Finish reconstruction -> and give the Value for the properties given. Fig: 9

Read More:
Reverse Engineering
Reverse Engineering of Printed Circuit Boards