For sample test, we often need to buy a small amount of film, although the agency 's quality is good, but too few generally reluctant to pay attention you, unless you are home and seeking the spot and, if the futures are not necessarily set to Minimum quantity, and delivery may look you can not accept applications for the same sample is not easy, then you can only look to the electronic market goods, market goods mixed head of fish, learn to identify good and bad;
1. Disassemble piece

The chips are removed from the circuit board to then classified, pin apparently had traces of solder welding, shiny, pin spacing ranging from obvious surface the size of printed text and images, fonts, shades of the difference is generally not the same production batch number, place of origin marking on the back of more complex

2.; Polished piece

these chips like the new film, the surface size of printed text and images, fonts, shades were no obvious differences, batch number are the same, but look closely and you will find chip surface has many tiny parallel scratches on the back of origin marking is not the same, pin normally would not be shiny, but matte, there are signs of oxidation, more consistent pin spacing.