Protecting Your Electronic Product From Copying
We have all heard about pirated copies of electronic products. One company started to notice a larger number of returns on a particular Internet router. Upon further investigation, it found the returns were a poor copy of its product but still they kept coming in; same box, same product and same literature. Even though the company took the blame from unsatisfied customers and initiated a serial number return policy, the damage to its reputation was done. The question is: how can a company protect itself from those who attempt to copy products?
One strategy is to use available technologies to make a product hard to copy. Most pirates do not want to spend the money to redesign a product if it costs too much. They want to make quick money by doing an easy reverse engineering job and then make a few hundred thousand cheap knockoffs. By making it difficult to copy a design you can increase the thieves’ cost and reduce their potential to make money. Time is their enemy.
The first step in slowing down the possible theft of your product, is to customize the printed circuit board (PCB). Most PCBs have green solder mask because, in the past, it was believed people did a better job assembling green boards. However, in today’s world of machine-placement, the circuit board color does not matter. Therefore, one easy trick to prevent fraud is to request a custom blended mask color. Solder mask companies make many different colors of solder mask, allowing you to create your own spectacular color by simply supplying the PCB manufacturer with the ink. It may cost a few cents more per board, but the vividly different color may slow down potential piracy.
On the board assembly side, it may be possible to slow down pirates by adding a tamper-proof coating to both sides of the most important chip areas. A good tamper-proof coating will be dense enough to stop x-ray examination, i.e. contain tungsten carbide ceramic nano particles. It should also be hard enough to deter easily picking it away and be opaque enough to stop easy tracing of the PCB tracks.
To add additional speed bumps to the pirates’ progress, further techniques can be used. For example, you can have a series of resistors and capacitors made that display the wrong value. These have been used on special protected government products where the resistor clearly was printed as a 10 ohm but actually was a 47 mega-ohm resistor, put across a couple of signal lines. While this may seem easy to get around, a pirate will have no idea that the number is intentionally incorrect. The pirate will copy the easy parts first and then spend valuable time troubleshooting. This can also be done for RF designs, with capacitors marked as one value while having a design critical requirement of a completely different capacitor.
This same remarking can be done to chips and other big parts. Remove the original marking by rubbing it with sandpaper and re-mark with a different common part number but with an extra 1 or 2 after the part number. That way, your internal parts system will recognize it as the correct part but the thief does not. If your design uses a common chip, remove the manufactures marking and re-stamp it with an uncommon chip number. This is easy to do with a white ink pad small rubber stamp.
Many companies can make PCBs with embedded components such as resistors and even capacitors. There are companies who will either embed 0201 components inside the multilayer or put them in film resistors. Again, you may know they are inside but a pirate does not. If he cannot get the prototype to reverse engineer the board working, it may slow down the pirate enough to stop the attempt. HDI boards are very hard to reverse engineer due to their complexity and small size vias.
One military agency used many tricks when an extremely secure product was required. It would have taken someone years to reverse engineer the circuit boards. The circuit boards had fake traces, hidden micro-sized wire bond wires over the chip and then tamper-proof coatings. When someone would grind off the coating, they cut the near invisible 10 micron wires which added difficulty in tracing the signal direction. They had mislabeled parts and even had fake chips, which did nothing but add to the confusion. The PCBs sometimes featured an on-board battery that kept the memory of the chip active, with more of the very fine wire bonding wires over embedded memory chips. If you cut into or damaged the tamper-proof coating, it erased the chip program memory.
While this level of misdirection may not be practical for the majority of consumer products, when you design the packaging, you might think about adding less complicated yet still effective countermeasures. A hard-to-copy feature such as a security stripe sticker, similar to that found in dollar bills is reasonably simple to implement. They can be made with your name in an invisible QR type code; not impossible to copy but tough. Or you can use a high security smart label. These feature a 64 bit security code exchange or use a non-removable RFID label. When you try to remove or reverse engineer the label, it rips and destroys the circuits inside. The RFID label receives a special signal from a reader which exchanges security codes and it sends an encrypted data code to ensure the product is not counterfeit. Your stores and warehouse can scan any product box and determine if the part is fake or real.
Depending on the level of confidence you have with your manufacturers and the sensitivity of your designs, special precautions may be necessary with the PCB supplier or plastic case manufacturer. Some pirates will try to buy boards, plastic cases, and products from your suppliers. Never buy all of a product from one source supplier and when using an assembler’s turn-key service, verify they are purchasing from multiple top-tier suppliers. Secure your plastic molds at a trusted plastic injector and keep track of how many cases they manufacture. Also, make sure to have the plastic product boxes secretly marked with your name. The case can be inexpensively marked with laser dots so small the human eye cannot see them. Typically, the most expensive part to copy is the plastic case. The cost of the die is large enough to warrant copying a product only for a really big sale potential. Unless their pirated sales would be a few hundred thousand dollars, it’s not worth the injection die development cost.
The ideas and tactics discussed in this document may seem extreme for most situations. However, pirating is very real. Forward thinking and protective measures can save money and protect your brand.