Chapter 8: Test

Questions:

1. What else should be provided at the side of the chips, as well as dc bias pads, to aid decoupling?

2. How much current can a typical probe needle feed onto the chip?

3. What does RFOW stand for, and what are its advantages?

4. How many contacts does an RFOW probe have, and what are they for?

5. What does the calibration do?

Answers:

1. A dc pad connected to a through-substrate via, preferably one for each bias supply.

2. 0.5A.

3. Radio Frequency On Wafer, which allows the rapid testing of all the circuits before scribing so that only good dies are assembled into systems.

4. Three: one central signal contact and two ground contacts on either side.

5. Calibration brings the measurement reference plane to a known point within the measurement system, typically to the RFOW probe tips.