# Presentation: 485310

## WBS 1.2Pixel Resource Loaded Schedule

- Simon Kwan

## Introduction

- Schedules prepared with no staging: build complete pixel detector
- Meeting with Procurement Dept
- Assumes that preproduction and production for sensor, ROC, HDI, and hybridization are linked; production is an option to produce more based of satisfactory results from the preproduction
- Same vendors, no fresh round of bidding for production
- Schedule assumes that
- Money will be available in FY05 and FY06 for these key purchases (including labor).
- Find out that we also need to move faster on the substrates procurement and fabrication
- Net result is about 11 months of float
- Methodology:
- Use detector READY-BY and NEED-BY date. Difference = Float

##                     Pixel Detector            WBS 1.2

- Pixel Sensor bump-bonded to Readout chip
- Fine segmentation
- 50 m x 400 m
- Large number of channels
- Electronics in the active tracking volume
- High power density (cooling system)
- Basic building block – Multichip Module (MCM)
- Large number of HDI and flex cables
- Assemble modules on substrate to form pixel half plane; an x-measuring half-plane and a y-measuring half-plane form a half-station

***Si pixel  sensors***

***Pixel Readout chip***

##                       Pixel Half-Station                 WBS1.2

- The temperature control elements modulate the temperature ofthe substrate

- Carbon fiber bracket

- Precision hole & slot washers

- Carbon fiber spacer

- PGS (Pyrolytic Graphite Sheet) flexible
- thermal coupling attached to copper
- tab LN2 heat sink

- TPG
- (Thermal Pyrolytic Graphite)

- Pixel modules placed on both sides
- of the TPG substrate
- (active region: ~10 cm long)

**                      **Pixel Half-Station                 WBS1.2

**Carbon support half cylinder (~1.26m long)**

## Pixel Detector Assembly

**Pixel Detector Assembly**

##                   Pixel Schedule Overview            WBS1.2

- Assumes that assembly of modules, half-plane (half stations) and half detector assembly will be done at SIDET
- SIDET has unparalleled infrastructure (Wire bonding machine, CMMs, probe stations, microscope, repair stations) and pool of experienced technical staff
- Significant expertise with carbon fiber at Lab 3 (carbon fiber support structure, brackets, lamination of TPG) and cryogenics & vacuum system in PAB and Mechanical Department
- Years of prototype experience and quite a few iterations of key components
- End point defined by Tevatron shutdown for FY09: 8/1/09 (was 6/1/09)
- Installation requires that pixel be ready by: 8/17/09 (was 5/4/09)
- Pixel installation has to occur before forward tracker; Pixel is critical path item
- Schedule estimate based on communication with vendor, prototype experiences and engineering estimates based on other similar projects. It does not skip any steps (prototype, preproduction, production); but production design cycle shortened (contingency increased to cover any added labor cost if needed)
- Preproduction precedes production and assumes that we don’t have to go through any bidding process; production is a continuation of the preproduction
- Schedule contains no explicit slack; task duration reflect nominal need for task completion

## Pixel Flow Diagram                     WBS1.2

## Key Milestones (old vs new)

| Milestone | Old (CD1) date | New (post-CD1) date |
| --- | --- | --- |
| PO for production sensors | Feb 2006 | Oct 2005 |
| PO for production pixel readout chips | July 2006 | Nov 2005 |
| PO for detector hybridization | Feb 2007 | April 2006 |
| Final detector assembly started | Nov 2007 | March 2007 |
| All pixel detectors delivered & tested | March 2008 | Oct 2007 |
| Pixel modules completed | May 2008 | Dec 2007 |
| Pixel detector ready for installation | Feb 2009 | Sept 2008 |

## Detector need-by date: August 17, 2009
Scheduled completion date: September 18, 2008 giving a total float of 229  working days
Pixel Detector will be installed as one piece (vessel with stations inside)
Pixel Detector has many components but the critical path is the making the pixel modules, placing them on a substrate (half-plane and half-station), and assemble the half-stations into the two half-detectors. This is a sequence of assembly and testing steps. Because we have 1380 modules in total, the duration of the each sequence is long (10 months or more). To keep this tight schedule, 
A lot of staggering in the activities
Place the orders early (sensor, ROC, hybridization)
Multiple paths/vendors
Sustain the flow of parts and have more than one assembly/test line/shift
Engage qualified vendors early in QA and throughput discussion

- Scheduled completion date: September 18, 2008 giving a total float of **229**  working days
- Pixel Detector will be installed as one piece (vessel with stations inside)
- Pixel Detector has many components but the critical path is the making the pixel modules, placing them on a substrate (half-plane and half-station), and assemble the half-stations into the two half-detectors. This is a sequence of assembly and testing steps. Because we have 1380 modules in total, the duration of the each sequence is long (10 months or more). To keep this tight schedule,
- A lot of staggering in the activities
- Place the orders early (sensor, ROC, hybridization)
- Multiple paths/vendors
- Sustain the flow of parts and have more than one assembly/test line/shift
- Engage qualified vendors early in QA and throughput discussion

- Critical Path Analysis            WBS 1.2

## Critical Path Gantt Chart                WBS1.2

## Bump Bonding

- The real critical path is bump-bonding. We have not had a large enough contract  with any vendor to certify the automation of the flip-chip assembly process -> importance of preproduction and doing this early
- In the CD1 review, reviewer made the following comments:
- Schedule was too aggressive
- Time from start of bump bonding to all detectors tested should be ~ 18 months ( we had 13 months)
- Time from start of bump bonding to completion of detector ~ 2.5 years (we had 2 years)
- Recommended to find ways to gain 6 months
- We have done this by placing the contracts early (sensor, ROC, and hybridization)
- Robustness checks

## Schedule  Robustness                 WBS1.2

- Schedule contingency
- Placed before key milestones or activities
- Nominally zero duration
- Can change duration to check robustness of schedule

## Schedule Robustness                   WBS1.2

## Pixel Construction Cost              WBS 1.2

**For comparison:**
**CD1 cost:  base – $15.46M, Contingency: $6.19M  Total $21.65M**

## Cost Comparison with CD1           WBS1.2

## M&S Obligation Profile by Fiscal Year   WBS 1.2

**FY05**

**FY07**

**FY08**

**FY09**

**FY06**

**Unescalated  k $**

**1000**

**2000**

**3000**

**Total: 8052 k$**

- 663k

- 2020k

- 1923k

- 139k

- 3286k

**0**

## Labor Profile by Fiscal Year      WBS 1.2

**FY05**

**FY06**

**FY07**

**FY08**

**FY09**

**0**

**10**

**20**

**30**

**37.5**

**FTEs**

- 13.5

- 29.6

- 28.0

- 37.3

- 4.4

## Responses to CD1 recommendations      WBS1.2

- Develop more conservative schedule with significant more float (> 6 months)
- We have followed their recommendation. By moving a few procurements forward and move back the detector need-by date, we have achieved a float of about 11 months.
- Evaluating options for relaxing the funding profile constraints to achieve a more conservative approach
- DONE
- Evaluate schedule and performance impact of staging options
- While we believe that the experiment will work with an efficiency of about 60%  with say 1⁄2 of the pixel stations, to complete the installation of the other half of the pixel detector will lead to a long shutdown, estimated to be about 6 months or longer and with considerable risk to the forward tracking stations (which need to be removed first before the pixel vacuum vessel can be taken out). After careful consideration, we think that it’s better to assign resources to guarantee the completion of the pixel detector on schedule and not pursue the staging option.