NOTE: Channel numbers in MCM convention, 0 - 255.

This assembly went through the laser scan test on 20-Dec-99 and 15 channels(57,93,175-186,208) of this assembly were idenfied as dead. Amongst these dead channels, 208 has been known to have the broken wirebond on the Si to kapton junction. Also, ch181 is short on the Si-strip and ch182 has high leakage current.

On 7-Jan-2000 bench cal test was done for dead channels. Among 15 dead channels, 8 channels(57,93,175,176,177, 185,186,208) were still O.K. But 7 channels of them appeared to have 0 slope for the bench cal test.

For this assembly, a laser hit on ch57 or 93 produces rather big ADC value increase of adjacent channels. The other dead channels do not show this effect.

On 4-Feb-2000, by disabling preamp channel 181,which is short on Si, 10 dead channels around channel 181 come back alive. Now this assembly has 5 dead channels.

last modified Jan-26-2000
YoungGook Kim