What are the methods to prevent PCB copying?

PCB copy board, be in namely have physical and electronic products under the premise of circuit board material, use reverse technology to reverse parsing of circuit board, the original products of PCB file and material list (BOM), schematic documents such as technical documents and PCB file for screen printing production 1:1 reduction, and then reuse these technical files and production of PCB board system, components welding, flying probe test, circuit debugging, complete model a complete copy of the original circuit.

What are the methods for preventing PCB copying?

1. Grinding, with a fine sandpaper models wear off on the chip. For partial door chip works, for commonly used chip, the thieves just guess about function, check what grounding pin, connect power is easy to control the real chip.

2, Sealing glue, use after the frozen like stone glue stick (such as steel, pottery and porcelain that) all the components on the PCB and its coverage. It can also be deliberately do five six fly line (best) with thin enameled wire twisted together, make the thief glue process will inevitably break down the fly line but I don't know how to connect to. Note that the glue is not corrosive, enclosed area heating is not too big.

3. Use a special encryption chip, such as the ATMEL AT88SC153 also just a few dollars, as long as the software can't be disassembled, the thief even logic analyzer with all signal intercept down is also unable to replicate.

4. Use undecidable chips such as EPM7128 and ACTEL's CPLD, but the cost is higher (over 100 yuan), which is not applicable to small products.

In general, MASK IC is much harder to crack than a programmable chip, which requires a lot of bulk. The MASK is not only to MCU, but also ROM, FPGA and other special chips.

6. Using the naked film, the thieves can't see the model or the wiring, but the function of the chip is not too easy to guess, it is better to decorate other things in the black glue, such as small IC, resistance, etc.

7. A series of electrical resistance above 60 ohms on a small current signal line, so that the thief will add a lot of trouble when using multimeter to test the connection.

8, Multi-purpose some no words (or only some code) of the small components involved in signal processing, such as a small patch of capacitor, the TO - XX diode, triode, three TO six feet small chip, etc., are still a little trouble TO find out its true nature.

9. Cross over some addresses and data lines (in addition to RAM, there is a corresponding crossover in the software), so that the thieves can't rely on the fact that they can be lazy when measuring the connection.

10. PCB USES buried hole and blind hole technology to hide the hole in the plate. This method is of high cost and only applies to high-end products.

11. Use other special kit, such as customized LCD screen, customized transformer, SIM card, encryption disk, etc.

12. Patent application.In view of the poor environment of intellectual property protection, the best way to choose foreign countries is only the last one.

Ago many formal copy board unit institutions have specific provision, whoever engages in reverse engineering of the customer, company must have a legitimate source of design copyright statement, to protect the legitimate rights and interests of copyright owners, original design and ask the customer commitment reverse result is mainly used for teaching, analysis, technical research and so on legal purposes.