LHCb Velo Construction Authorisation steps

Tony Smith

Authorisation 1- stages 0-7 Before PA and chip attach

• Stage 0 – Bare substrate

• Stage 1 – Reception of Hybrid

• Stage 2 – Thickness measurements at 16 chip sites

. • Stage 3 – Metrology (before

population)

• Stage 4 – Additional Metrology/send for population

• Stage 5 – Electrical tests after population

• Stage 6 – Clean and Inspect 

• Stage 7 – Metrology

Check log file entries for stages 0 to 7

for comments and assess these

Check twist and thickness criteria and electrical tests are passed

PASS go on to next stage, FAIL – reject, FIX – repair and repeat

Authorisation 2 Review stages 8-19

Before sensor Gluing IStage 8 – Glue r-side pitch adaptorsStage 9 – Glue r-side chips Stage 10 – Glue p-side pitch adaptorsStage 11 – Glue p-side chipsStage 12 – Bond backend r-side chips Stage 13 – Bond backend phi-side chipsStage 14 – Electrical test on all chipsStage 15 – Replace faulty r-side chips Stage 16 – Replace faulty phi-side chips Stage 17 – Front end bond r-side chips Stage 18 – Front end bond phi-side chips Stage 19 – Electrical test

Authorisation 2 Review stages 8-19

Before sensor Gluing I• Check CM subtracted noise and pedestal plots to

confirm operation of all ADC channels and identify bonding shorts.

– Typical plot (M87 chip14 Phi) showing two shorted channels

Note that it is not possible to spot open circuit channels at this stage as the noise due to the capacitive load of the PA’s is too small

Authorisation2 sensor gluing II

Check individual chip plots and full sensor channel plots for shorts. A small number of shorts (1 or 2) is OK. Note that any possible rework will already have been done – but check log.

Authorisation 3 – Review Steps 19-25

Before Hybrid to pedestal gluing

Stage 19 – Electrical test after FEBStage 20 – Glue sensors    Stage 21 – Metrology of Sensor-Sensor AlignmentStage 22 – Bias Bond Measure IV – compare with bare sensorsStage 23 – Bond r-sensor Stage 24 – Bond phi-sensorStage 25 – Laser test Results (see Kurt and Girish’s Talks) plus IV – compare with pre bonding plot

Proposed new inspection and authorisation steps

Stage 8 – Glue r-side pitch adaptorsStage 9 – Glue r-side chips Stage 10 – Glue p-side pitch adaptorsStage 11 – Glue p-side chips New inspection - gluing?? Stage 12 – Bond backend r-side chips Stage 13 – Bond backend phi-side chipsStage 14 – Electrical test on all chipsStage 15 – Replace faulty r-side chips Stage 16 – Replace faulty phi-side chips New authorisation

–include PCN check??Stage 17 – Front end bond r-side chips Stage 18 – Front end bond phi-side chips Stage 19 – Electrical test