January 27, 2006
News - Low-Cost Eye Tracker
about 3 years ago
IEC 60601-1 covers the safety requirements of medical electronics. You should read it. The issue with patient connected electronics has to do with isolation from mains power. Most electronic devices that are powered from the AC line are isolated from the AC line by a transformer. If that isolation fails, the connected patient can be electrocuted. IEC 60601-1 requires an additional isolation barrier for patient connected electronics.
Powering the device from a battery and not allowing any means to charge the battery while connected to the patient would get you around the isolation issue.
News - Revisiting the Counterfei…
about 5 years ago
I am an engineer and have worked on several ASIC’s. The copper slug is part of the leadframe, but the backside of the die attaches to the slug. The purpose is to get a solid Vss (or Vdd, depending on the process) connection to the die substrate. The pads where the bond wires attach is on the surface of the die, opposite the backside. Someone mentioned a bond wire that goes “nowhere” on the counterfeit – that is how Vss (or Vdd) is connected to the copper slug from a Vss (or Vdd) trace on the topside of the die.
Semiconductor devices are first tested at the wafer level. Bad die are marked with an ink dot. The tested wafers are sent to a packaging house where the wafers are sawed into individual die. The die are packaged and then retested. Good packaged parts are then marked. These counterfeit parts are probably packaged parts that failed testing after packaging. These parts should be disposed of, but not all are. These parts just need to be marked to look “real”.
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