Posted by fnkek: Thu Sep 28, 2006 4:32 pm    Post subject: Open/short and Leakage test

Hello to all Test expert,

Can someone explain to me on;
1. What is open/short test? And how does it works?
2. What is Leakage High/Low test? What's the different between high and low and how does it works?

Your help is much appreciated
Thanks.................

Posted by Asmoth: Tue Oct 10, 2006 9:40 pm    Post subject:

Hello fnkek,

1. Open/Short Test

-Open/short test is a simple but very effective test in determining if the DUT pins is properly aligned to their respective contactor filaments. It will detect any misalignment or misorientation. Once detected, the testing process will no longer proceed to the succeeding tests(if on "stop on fail" mode). It is usually carried out as the first test.

-Open/short test are mostly conducted on the digital pins. It works with the principle that a diode is connected between the pin under test and ground (Anode connected to ground, cathode connected to the DUT pin). The test instrument (ie. pin cards) will force a current(~500uA) out of that pin, turning on the diode. Once the diode turn on, it will exhibit a voltage of around -500mV with respect to ground (In school, this is ~+/-0.7V). If the pins is properly clamped on its respective filaments, then it will exhibit this voltage, else, it will exhibit a different voltage level that is usually way off the expected -0.8V->0.4V range.
_________________
Asmoth72

Posted by Asmoth: Tue Oct 10, 2006 9:47 pm    Post subject:

Hi fnkek,

Leakage Hi/Lo Current is the current that flows on the digital pins when these pins are subjected (forced) with

a. a low potential (i.e. 0V) for leakage Lo current, and
b. a high potential (i.e. the supply voltage level) for leakage Hi current
_________________
Asmoth72