Thursday, June 9, 2011

Booboo shares thoughts on NJ Pocket

Booboo very kindly dropped me a note about the NJ Pocket:

The black glossy blob: that's the microcontroller.
Usually, the silicon is encapsulated in a epoxy body with pins, and tiny wires are connected from the pins to the silicon. Then what you have is a package easy to handle and solder on a PCB using standard techniques.
However, it is also possible to buy the bare silicon die from the manufacturer. You just glue the die to the PCB and then connect the wires from the die to pads on the PCB. Finally, you put a few drops of epoxy to make it a solid, robust block like the one you see in the picture.
Advantages: cheaper for very large scale production, you save the cost of encapsulating the die as a component.
Disadvantages: you need special, very expensive equipment to connect the wires from the silicon die to the PCB (the junction is made by ultrasonic vibration).
Also, for us it means that since there are no marks on the chip package (because there's no package in the first place), we have no clues on the manufacturer, model, etc.
The black blob on the picture could be removed with a mixture of nitric and sulphuric acid to expose the die and with a microscope you'd probably be able to see some markings on it that would help identify the manufacturer.
Don't think it's worth, obviously!

The expensive ultrasonic machine means the maker is probably in the toy manufacturing market, where it's worth saving $0.02 in chip packaging if you're manufacturing 10,000,000 units.
Also, note that the setup of the machine is also costly, which is probably why this device is made up of a "core" board with some other auxiliary boards connected for controls and such. They have probably manufactured a damn lot of those "core" boards and you'll find them into many of these ultra cheap consoles.
This *could* be interesting as a hacking platform due to the low price, but we would need first to identify the microcontroller, and given it's probably from a Chinese semiconductor manufacturer, I wouldn't even bother because even if we're able to identify the part you won't have any docs.

Whoever makes the NJ Pocket, please give Booboo a yell!

1 comment :

  1. Hmm... Interesting :)
    How about asking to Mr. Booboo about an ereader Augen "the book" ( I suppose the devise sold on DX it's not a real Augen but the same specs. I think it's a HiVision production).
    It's interesting to know why is slow in some PDF and if it is posible to modify a firmware to add more functionality and make it better.
    I found something here