Microcontroller IC Unlock Failure Analysis will need to go through the process of FOCUS ION BEAM, as we know this process is a very time consuming and expensive process, anyway, as the most important step of microcontroller IC unlock, we need to analyze its failure probability and see if there is any way to low down it:
A. Microcontroller IC tape out technology is too small to unlock and locate, so it brings a lot of difficulty to find the right position of security fuse. Such as PIC16C7X series and PIC16C6X series;
B. the FOCUS ION BEAM is too long to withstand the strengthness of electrical connection when unlock microcontroller IC, which cause the failure of focus ion beam;
C. There is insufficient controlling on the focus ion beam when unlock microcontroller IC, too much or too few of focus ion beam will cause the failure of this process;
D. there is some malfunctionality on the focus ion beam facility. (currently most of our focus ion beam facilities are imported from TAIWAN or U.S. America second hand dealer, after all the failure rate is exist but not as much as to affect the whole business of microcontroller IC unlock ).
E. Some of the microcontroller IC unlocking process needs to do the focus ion beam in multiple times within the same area or in the same time, it is very complicate process and very likely to get mistake operation;
F. The microcontroller IC design for anti-electrical static discharge is not good enough, such as AT89C2051, Microcontroller IC Unlock Failure Analysis is quite suspectible to get damaged in the later procedure after focus ion beam when unlock it;
There are some other reasons which will cause Microcontroller IC Unlock Failure Analysis, such as the consistently improving encryption technology for instance, ATmega48 microcontroller IC unlock, the embedded firmware of this chip will alter once you read it by programmer.
And we also encounter a tiny13v with the software encryption issue. We do the experiment on it and found an very interesting result: the extracted firmware can only be used on the original microcontroller IC after unlock it. When we programme it onto other microcontroller attiny13v IC, only 1pcs is workable on the 256pcs of new ones.
Besides, programmer flaws, too much pinouts have been burned and protection circuit being broken, low level misoperation will cause the failure of microcontroller IC unlock.
Some of the microcontroller IC unlock are completed only by hand, such as HT & MDT. This has great connection with the operator experience and skill. Due to the program of microcontroller IC are all stored by the internal ion as media, so Some of the microcontroller ICs unlock might be failure due to the long time length of manufacture date and affected by external magnetic field. Furthermore, like GAL microcontroller IC which has the time clock and sequence will have the probability of failure when unlock.
B. the FOCUS ION BEAM is too long to withstand the strengthness of electrical connection when unlock microcontroller IC, which cause the failure of focus ion beam;
C. There is insufficient controlling on the focus ion beam when unlock microcontroller IC, too much or too few of focus ion beam will cause the failure of this process;
D. there is some malfunctionality on the focus ion beam facility. (currently most of our focus ion beam facilities are imported from TAIWAN or U.S. America second hand dealer, after all the failure rate is exist but not as much as to affect the whole business of microcontroller IC unlock ).
E. Some of the microcontroller IC unlocking process needs to do the focus ion beam in multiple times within the same area or in the same time, it is very complicate process and very likely to get mistake operation;
F. The microcontroller IC design for anti-electrical static discharge is not good enough, such as AT89C2051, THE microcontroller IC is quite suspectible to get damaged in the later procedure after focus ion beam when unlock it;
There are some other reasons which will cause the microcontroller IC unlock failure, such as the consistently improving encryption technology for instance, ATMEGA48 microcontroller IC unlock, the embedded firmware of this chip will alter once you read it by programmer.