Firstly this blog post is not about how to steal your competitors’ IP (intellectual property). Nor is it how to identify technical weaknesses in competitor products! This is about reverse engineering your own products where the data to manufacture or modify them has been lost. This can be due to software incompatibility, failed backups, or simply be a loss of knowledge about how the product works.
Why would you want to reverse engineer your own products?
are some of the reasons for updating existing products. Competitors bringing out innovative features can also drive the need for changes.
Where the design’s CAD data, descriptions, bill of materials, gerbers & assembly, test and setup instructions are available in an accessible format these changes are often straightforward. We regularly see companies that need to make changes to products. Products that have been in manufacture for 5, 10 or even 15 years. The longer the time elapsed since the design, the harder the change can be to make without some degree of reverse or re-engineering the products source data.
What can be done?
The starting place for any product data reconstruction is the available data. Conversations with staff which were involved in the design, manufacture or updates can also be helpful.
If the design is very old there may be no electronic records at all. Schematics may have been hand drawn on paper. Printed circuit boards may have designed using self-adhesive tape and photographic exposure. The good news is that the circuit boards are likely to be at most two layers and by modern standards are fairly simple. Two-layer boards are easier to check connectivity. All of the tracks are visible. The tracks and pads alone give away a lot of information.
Designs may have some form of electronic data available such as gerber files which are the pcb manufacturing image data. Printed circuit board (pcb) manufacturers load these into a photo-plotting machine and make the photo-tools required for manufacture. These files can be visually inspected with a Gerber viewer such as GerbV or the Camtastic tools within Altium Designer. It is possible to make minor modifications to the gerber files directly with care.
If the change is more significant than a minor change to the pcb artwork things start to get more complex and time consuming. The gerbers can be processed to produce a netlist of connections. However, these will be missing the net names, drill and via information, component detail and layer stack.
The component information can often be found on integrated circuits by using their individual markings. Some passive components, mostly resistors down to 0603 size, have a value code on them. Capacitors and inductors and resistors below 0603 don’t have markings. These can either be removed from the circuit board and measured, checked on a bill of materials or inferred from the connections of the main ICs.
Consider Redesign instead
At this point unless there is a really good reason for reverse engineering the board such as avoiding additional compliance approvals or contractual obligations other options should be considered instead. The time necessary to discover and recreate the schematic, printed circuit board and bill of materials may be better spent in producing a new design. That new design could be backwards compatible with the existing design and use modern components with better performance, more availability and potentially lower costs.