Mass Chip Test & Outer Barrel Hybrid Integrated Circuit Assembly for ALICE ITS Upgrade and Study of Monolithic Active Pixel Sensor = 대형 이온 충돌 실험 (ALICE) 내부 궤적 장치 (ITS) 업그레이드를 위한 대용량 칩 테스트 (MCT) & 외부 원통 복합 집적 회로 조립 (OB HIC Assembly)과 단일형 활성 픽셀 센서 (MAPS) 연구

다국어 초록 (Multilingual Abstract)

A Large Ion Collider Experiment (ALICE) team has planned the upgrade of the Inner Tracking System (ITS) during Long Shutdown2 (LS2) of a Large Hadron Collider (LHC) for following the increased beam luminosity. The new ITS will be improved as follows. First, a distance between the first layer and the interaction point will get close from 39 mm to 23mm, the material budget (X/X0) will be smaller from 1.14% to 0.3%, and the pixel size of the detector will be smaller from 50 μm x 425 μm to 26.88 μm x 29.24 μm. These allow the improvement of impact parameter. Second, only a silicon pixel detector will be used, and the detector layers will be increased from 6 to 7. These allow the improvement of tracking efficiency (position resolution ~5 μm) and momentum resolution at low transverse momentum(pT). Third, data read-out rate will be improved to 100 kHz (in p-p collision), 400 kHz (in Pb-Pb collision) from 1 kHz.
Monolithic Active Pixel Sensor is a new sensor which integrates the read-out circuitry and the sensor, and it has high granularity, low material budget, and fast read-out rate. In the new ITS, ALICE Pixel Detector (ALPIDE) which is made by MAPS technology will be used. In the ITS upgrade project, around 60k ALPIDE chips were tested. Tested ALPIDE chips will be assembled for Outer Barrel Hybrid Integrated Circuit (OB HIC), and around 2000 HICs will be assembled.
Pusan National University and Inha University co-worked together for the chip test and the OB HIC assembly. The chip test and the OB HIC assembly is done by ALICE Integrated Circuit Inspection and Assembly (ALICIA) machine. Around 11k chips were tested from 2017, and around 300 OB HICs will be assembled until May 2019.
The investigator chip which is researched in this thesis is MAPS. It has 134 mini-matrices which has various pixel design. 64 pixels can output analog signal in parallel with 65 MHz sampling rate. The investigator chip was measured with the DAQ board and a 55Fe source for the research. From the experimental results with various reverse bias voltages, pixel pitches, diameters of the collection n-well diode, and spacings, relative depletion regions were estimated and the Charge Collection Efficiency (CCE) and the Charge Collection Time (CCT) were researched.

목차 (Table of Contents)

• 1 Introduction 1
• 1.1 Large Hadron Collider, LHC and A Large Ion Collider Experiment, ALICE . . . 1
• 1.2 Inner Tracking System Upgrade Project . . . . . . . . . . . . . . . . . . . . . . . 2
• 2 Mass Chip Test 7
• 2.1 Chip Production . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
• 2.2 MCT (Mass Chip Test) System . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
• 2.3 Test Procedure in PNU . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
• 2.3.1 Visual Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
• 2.3.2 Dimension Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
• 2.3.3 Electrical Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
• 2.4 Problematic items and solutions . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
• 2.4.1 Needle Contact to the Chip Pad . . . . . . . . . . . . . . . . . . . . . . . 15
• 2.4.2 Yield Problem . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
• 3 Production of the Outer Barrel Hybrid Integrated Circuit (OB HIC) 19
• 3.1 Assembly System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
• 3.2 Assembly procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
• 3.2.1 Chip placement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
• 3.2.2 FPC gluing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
• 3.3 Electrical Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
• 3.4 Problematic items and solutions . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
• 3.4.1 Problems of the edge inspection . . . . . . . . . . . . . . . . . . . . . . . . 30
• 3.4.2 Repositioning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
• 4 Further Study on Pixel Chip Characterization 34
• 4.1 Monolithic Active Pixel Sensor (MAPS) . . . . . . . . . . . . . . . . . . . . . . . 34
• 4.2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
• 4.3 Sensor performance with various pixel design . . . . . . . . . . . . . . . . . . . . 37
• 4.3.1 Relative depletion volume . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
• 4.3.2 Experimental setup with 55Fe X-rays . . . . . . . . . . . . . . . . . . . . . 45
• 4.3.3 Pixel pitch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
• 4.3.4 Diameter of collection n-well diode . . . . . . . . . . . . . . . . . . . . . . 48
• 4.3.5 Spacing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
• 4.3.6 Reverse bias voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
• 4.3.7 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
• 5 SUMMARY 55