V. Cindro, Jožef Stefan Institute, Ljubljana, Slovenia DAQ, DCS, Power Supply and Cables Review CERN, March Electrical PP1 Basic features Electrical schematic Mechanical layout Prototyping Tests before production QC

V. Cindro, Jožef Stefan Institute, Ljubljana, Slovenia DAQ, DCS, Power Supply and Cables Review CERN, March Basic features: Accept Low Mass Tape on the module side and type II cable on the power supply side. It provides pads for soldering of the low mass tapes to the printed circuit. Two connectors are used for one type II cable to minimize the space requirement It provides filtering of noise on the electrical lines Radiation hardness CO 2 environment Forward and barrel have different mechanical constraints. 2.5 mm rule (IPC spec) for 500 V on opened areas obeyed (pins on connectors will be pulled out)

Barrel schematic: control lines are AC coupled to the shield V cc, V dd and HV lines are AC coupled to their return lines DGND is DC connected to the shield AGND and HVGND are AC connected to the shield ILEDa and ILEDb lines are shorted

Forward schematic: Same as PPB1 except: DGND is AC connected to the shield ILEDb line on module side and Temp2 line on PS side are treated as a spare line V. Cindro, Jožef Stefan Institute, Ljubljana, Slovenia DAQ, DCS, Power Supply and Cables Review CERN, March

Barrel PPB1 has 8 conductor layers and accepts 6 modules

V. Cindro, Jožef Stefan Institute, Ljubljana, Slovenia DAQ, DCS, Power Supply and Cables Review CERN, March Forward PPF1 has 4 conductor layers and has 2 and 3 module versions. On discs 1- 8

V. Cindro, Jožef Stefan Institute, Ljubljana, Slovenia DAQ, DCS, Power Supply and Cables Review CERN, March Forward PPF1 on disc 9: There should be a drawing with just two modules

V. Cindro, Jožef Stefan Institute, Ljubljana, Slovenia DAQ, DCS, Power Supply and Cables Review CERN, March Prototyping: Prototypes of PPB1 have been used in the system test before production, noise performance of system was measured Prototype harnesses have been assembled and tested with PPB1 Electrical prototypes of PPF1 have been used in the system test Thermode soldering of tapes has been developed at RAL on protypes, procedure improved with hot plate soldering at Taiwan during production → less cold solder joints

V. Cindro, Jožef Stefan Institute, Ljubljana, Slovenia DAQ, DCS, Power Supply and Cables Review CERN, March Tests before production Radiation hardness was checked up to 10 MRad (resistances, capacitances measured) – no change of C and leakage currents was measured Accelerated aging at 100 o C in CO 2 was checked Duration of aging: 72 hours (1st step) + 48 hours (2nd step) Acceleration factor (20 o → 100 o ) : 110 (Ea = 0.5 eV), 8000 (Ea = 1.0 eV) Interline resistance, HV leakage current and line + solder joint resistance were measured before and after aging Bias: 500 V at HV line during aging

V. Cindro, Jožef Stefan Institute, Ljubljana, Slovenia DAQ, DCS, Power Supply and Cables Review CERN, March

QC during production : After the assembly with components, the boards should be tested by the producer. Following tests shall be performed: 1. Connectivity and Capacitance test a.) Connection from the connector to the capacitance required b.) Resistance up to 2 MΩ Between any two lines or ground - rejected c.) Capacitance value agrees within 20 percent with nominal 2. Trace resistance test: measurement of the resistance between the connector and LMT solder pad with 20 Ω range and 10mΩ resolution. Resistance of each line should agree within 30 percent with the average value (average measured for that line within the production batch). 3.High voltage test: 500 V test for 10 s on the HV bias line. Leakage current between HV bias line and HV return line and between HV bias line and Ground shall be less than 100 nA.

V. Cindro, Jožef Stefan Institute, Ljubljana, Slovenia DAQ, DCS, Power Supply and Cables Review CERN, March Production: 440 (all) PPB1 have been already produced, B3 harnesses already mounted First batch of 620 PPF12 and 450 PPF13 in production, shipping to Taiwan within two weeks

V. Cindro, Jožef Stefan Institute, Ljubljana, Slovenia DAQ, DCS, Power Supply and Cables Review CERN, March Related documents: Explanation of LMT harness routing from PPF0 to PPF1 ATL-IS-EN-0026 PPB1 For Fibres and Low Mass Tapes ATL-IS-ES SCT End-cap LM tape mapping table - module to PPF1 ATL-IS-EN-0024 End-cap Module and Services Position Numbering Scheme ATL-IS-EN Spreadsheet of Low Mass Tape Length from PPF0 to PPF1 on SCT end- cap ATLAS-IS-ES-0095 Technical specification for the manufacture and supply of low-mass tapes for the ATLAS SCT detector ATL-IS-CS-0014 SCT Low-mass Power Tapes ATL-IS-AT-0013 PPF1, LMT and PP0 assemblies for the forward part of the SCT (in preparation, draft on