There is other reconstruction method that involves building complete packages solely from imported graphic elements and subsequently the components. The parts may be rebuilt too but there is also an option to assign matching parts from System Library. Packages are reconstructed from elements imported to several categories. Silkscreen elements defines outline. Pads positions define not only footprint locations of but also locations of holes and their diameters. Elements extracted from pads categories are used to build pad stacks. Kit project NWSTUT_IMP2.epb has been especially prepared to illustrate this method of component reconstruction. It is more complete that the other sample and includes elements used for building pad stacks. In this particular case, the circuit consists only of pin mounted devices and elements were imported to category Thrupads Padstacks.

The pad stacks in the reconstructed symbols are built from elements imported to categories Thrupads Padstacks, SMD Padstacks Comp. Side and SMD Padstacks Solder Side. Imported pad position for all above type of pads define among other things X=0 and Y=0 coordinates in reconstructed pad stack. Only those elements from pad stack categories that overlap pad position will be included in reconstruction. Pad stacks for PMD components must have holes diameters assigned. This should be done after importing all elements to Thrupads Padstacks. It is assumed that pads of certain size should have corresponding hole diameter. In other words, common hole diameter may be assigned to all pads of the same size and shape, which in turn depends on apertures defined in the Gerber artwork. Hole diameter assignments must be done prior to component reconstruction as the last stage of graphics import. The procedure is following. Select Graphics Import toolbar and Trupads Positions as active category. Afterwards select tool Create graphic item and click on option tool Assign holes (F2). This action will result in pop-up dialog where hole diameters for all different apertures used in imported part positions may be entered. (This operation has already been done in our example)

Open this project NWSTUT_IMP2.epb and invoke Fabrication manager. Select toolbar Reconstruct from graphics and subsequently tool Reconstruct Component. It should be clearly visible on the screen that silkscreen and footprints form five distinct patterns in the imported graphic, equivalent to component images on the PCB. Let’s assume that these components should be reconstructed as: U1 – part 7474
U2 – part 7474
U3 – part 7404
U4 – part 7486
U5 – part 7420
Activate option tool Reconstruct component/package from graphics (F1). Graphic pattern containing image of 14 pin DIL package of U1 may be selected by dragging a bounding rectangle around it. In result of this operation all elements inside rectangle are highlighted and will be used as template for reconstruction. At this stage four additional tools are temporarily added to the option tools toolbar.

There may be some redundant elements closed within bounding rectangle. For example there may be lines in the silkscreen that constitute component name. There is no need to include them in reconstructed package (component names are generated automatically). Option tool Toggle inclusion of selected silkscreen graphic item (F4) may be used to exclude redundant silkscreen pattern elements from taking part in reconstruction. Single item selection or selection by dragging bounding rectangle may be applied at this point In similar fashion, but using tool Toggle inclusion

It is important that pads – pins in the reconstructed package - are properly numbered. Pin numbers are initially assigned when the pattern is selected, but these numbering may not necessarily be correct. Tool Assign pin number to select pad (F6) is provided for the purpose of arranging proper pad numbering sequence.

Clicking on the tool Finish reconstruction (F7) results in pop-up dialog where user has to specify additional information needed for reconstruction. Package name is mandatory and has to be unique within the project. By setting Component name to “none” user may direct the program to reconstruct only the package that will be placed in project library. Such package may be farther edited

Entering project unique component name means that the program is set to reconstruct the package and finally the component. In this case part name has to be entered in the corresponding box in the dialog. There are two possible modes for assigning parts to the reconstructed components. The program may create a new part with entered name (Assign box set to “Scratch”). Such part will have only reference to reconstructed package. No reference to schematics view will be generated at this stage and if needed has to be added later by editing this part in Library Editor. By setting Assign box to “Library Part” user may order the program to fetch part from the System Library. The part will be assigned if its description (number of defined pins) matches reconstructed package. If this is a case, the part will be loaded to project library and it original package reference altered to reconstructed package. Assigning part from System Library results also in creation of schematic representation of the component, since necessary information (schematic symbol and pin-out) is defined in the part description. There are certain restrictions in using this mode. Part cannot be already in use in the project and if reconstructed package differs in number of pins then this mode will be refused. Accepting reconstruction parameters orders the program to complete the procedure. The reconstructed component will appear in place of highlighted template. Elements of template are no longer needed and the program will remove all of them if Do not remove package template box is left unchecked.

Usually there are more components on reverse-engineered board that share the same package or part. This applies to our example too. In such instances it is not necessary to repeat reconstruction of each component in above described manner. Instead, they may be copied and snapped into desired location using pattern of pad positions as a placement template. For this purpose the tool Copy select component and place (F2) is provided. The procedure consists of two steps. In the first step the “source” source component has to be identified by clicking on any of its pads. If not specified otherwise, the program will ask for copied component name, create it and start its relocation. The actual placement of the new component is done exactly in the same way as described in Part 1 of this article. The component should be moved in such way that selected pad hovers over corresponding pad position. Subsequent click anchors the component. The program continues automatically to rotate the component around selected pad to find best match for remaining pads in surrounding pattern of pad positions. There are two other options connected to this tool (F4 and F5) – one for ordering this rotation to take place in 90 degrees steps and the other for using steps specified by value in Angle Snap box. In our example this procedure may be used to copy U1 to U2 since they are instances of the same part – 7474. But because each of other components represents different part, the part reference has to be re-assigned while copying. Additional option tool Change part assignment (F6) should be active in order to assign part to copied component in case it differs from part referenced by “source” component. Identical rules apply here as with part assignment for component reconstructed from package template (see above). This option has to be ON while copying U2 to U3, U3 to U4 and U4 to U5. When this last copying is done all components on this board are reconstructed. To rebuild the rest of the board, use automatic reconstructing tools for via holes, traces/netlist and finally for copper pour areas