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CMS Pixel Detector
Miscellaneous
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Phase 1
Phase 2
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Layer 1 Replacement
Layers 2-4
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| Layer 1 Replacement Elog |
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Message ID: 296
Entry time: Fri Aug 14 13:47:26 2020
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| Author: |
Andrey Starodumov |
| Category: |
General |
| Subject: |
new PH optimisation test and Total Overview |
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New PH optimisation is done at -20C as a FT, hence the results of this test are added to "DB" file as the second m20_1 test.
If there are more than one result per test in the DB file the total production overview is corrupted in a way that for such
modules # of defects is not calculated (due to ambiguity) and hence these modules are not rank according to the number of defects.
To correct this one has to remove from the DB file the second row with the same test. In our case one needs to remove the "old" m20_1 test.
While doing this I noticed that some new FT ended with grade C while the previous ones were fine (graded B) or some subtests are failed
wile grading remains B. Here is the list of such modules:
M1546 graded C
M1556 graded B but trimming completely failed (DTB_WRE1O5): TO RE-TEST
M1624 graded B but instead if 79 pixel defects it has 295 in 3 chips due to trimming problem (DTB_WRE1O5): TO RE-TEST
M1600 graded B but instead of ~50 pixel defects it has about 300 due to trimming problems (DTB_WXC03A): to retest
In general latest FT at -20C has shows less defective pixels and bumps but often leakage current is slightly higher. |