# Presentation: 524586

## Module AssemblyWBS 1.1.1.5

- Pixel module anatomy
- Assembly Flow
- Individual pieces
- Production Plan and Rates
- Cost and Schedule Summary
- Development plans

- M. Garcia-Sciveres - ATLAS Pixel Review - Module Assembly

## The Pixel Module

**Schematic Cross Section**

- (through here)

**Perspective **
**View**

**Bumps**

**Flex Hybrid & Pigtail**

**Sensor**

**Wirebonds**

**ASICs**

- pigtail

- beyond

- M. Garcia-Sciveres - ATLAS Pixel Review - Module Assembly

## Slide 3

- M. Garcia-Sciveres - ATLAS Pixel Review - Module Assembly

## FE IC Wafers and Die

- US to **thin** and **probe** wafers
- US to return **Known Good Die** (KGD) to bump vendors

- When Do We Probe Wafers/Die?

- During development:  after fab, bumping, thinning & dicing.
- After all yields are known can select best stage(s)
- Same setup used at all stages.
- Bumped wafers must be probabed (=> resist openings)
- Use CDF method for single die probing.

- M. Garcia-Sciveres - ATLAS Pixel Review - Module Assembly

## Bump Bonding

- Bump Bonding is a non-US responsibility.
- Includes deposition of **bumps**/**under bump metalization** on **FE IC**/**sensor wafers** as well as flip chip assembly.
- STATUS:
**Two vendors** qualified via dummy and active prototypes (small qtty)
- Both have handled 4” sensor and 6” IC wafers.
- They have or are acquiring 8”  wafer capability.
- IZM and AMS to produce 2x50 dummy modules in 2001(mechanically identical to production modules)
- Active modules to be produced in 2001 as FE IC availability permits.
**Third vendor** being considered (only has 6” wafer capability => DMILL FE ICs).
- Projected production rate **40 modules/wk **(20 IZM + 20 AMS).

**IZM **(GER)** – solder bumps**

**AMS **(IT)** – evaporative indium**

**Sofradir** **– reflowed indium**

- M. Garcia-Sciveres - ATLAS Pixel Review - Module Assembly

## FE  IC  Wafer  With Bumps

- M. Garcia-Sciveres - ATLAS Pixel Review - Module Assembly

## IC Wafer Thinning

- Thinning of all IC wafers is a US responsibility.
- FE IC wafers are **back-ground **to **reduce material** and **fit envelope**.
- Final thickness **150********m** (goal) to **300********m** (current envelope limit).
**6”** Wafers processed by **AMS** have been thinned to 150-175mmand thinned die have been used to build active modules.
**6”** Wafers processed by **IZM** have been thinned to 200mm. Limitations understood and dummy wafers are in preparationwith modifications to the protective photoresist application.
- All grinding done at Okamoto, San Jose (automated facility).
- Investigating possibility of European vendor as second source and to reduce shipping of IC wafers.
**8”** wafer thinning to be explored. **300********m** may be the limit.

- M. Garcia-Sciveres - ATLAS Pixel Review - Module Assembly

## Single Die Probing

**Fixture used to Probe 8,000**
**SVX3D chips for CDF**

**CDF Chip Probing**** **
**Results**

- M. Garcia-Sciveres - ATLAS Pixel Review - Module Assembly

## Bare Modules

**US to probe and accept for module assembly.**
**Prepare to debug modules that fail probe.**
**Must know identity of each die (marking under study).**
**Assume returning to bump vendor or elsewhere for die replacement.**

- Back sides of 16 FE ICs

- Detector barely visible

- M. Garcia-Sciveres - ATLAS Pixel Review - Module Assembly

## Flex Hybrid and Pigtail(Covered in separate presentation)

- US to fabricate all flex hybrids and load passives.
- US to share MCC loading and test.
- US to fabricate and test all **disk** pigtails.
- Flex hybrid is **universal** up to module assembly.
- Customized for specific disk by adding pigtail before module assembly.
- Flex with pigtail must be Known Good Part. (tested all connections, MCC function, HV paths)

- M. Garcia-Sciveres - ATLAS Pixel Review - Module Assembly

## Mechanical Assembly

-     **Prototype fixtures designed, built and tested**

- M. Garcia-Sciveres - ATLAS Pixel Review - Module Assembly

## Assembly of Modules onto Sectors

- Carbon  sector structure

-     Thermal compound  for FE chips on module

**     ****Same base assembly as Module fixture.**
**     ****Prototyping advanced: techniques used to test prototype sectors.**

- M. Garcia-Sciveres - ATLAS Pixel Review - Module Assembly

## US Production Sites

**Wafer/Die Probing: ****LBNL**
**Wafer thinning**: **Okamoto **(Bay Area)
**Wafer dicing**: **various qualified vendors **(Bay Area)
**Die sort and mark**: **LBNL**
**Bare module probing**: **LBNL**
**Flex Hybrid Fab:**** ****Compunetics-type vendors TBD,  CERN.**
**Flex Hybrid assembly**:** Flex One, SMD, etc., ****Oklahoma.**
**Module mechanical assembly(25% of total)**: **LBNL**
**Module wire bonding**: **LBNL** and **Ohio State**
**Module testing**: locations TBD, depending on availability of **& Burn-In**         manpower and equipment (eg. wire bonding for  			    repair) **LBNL** , **Ohio State** possible,                           **Oklahoma, New Mexico** under development.
**Module attachment to disk sectors and test**: **LBNL**

- M. Garcia-Sciveres - ATLAS Pixel Review - Module Assembly

## US Production Rates

- Current scheduled bare module rate is ~**6/wk** to **LBNL**(vendor projected capability is 10/wk)
- Planning  **2 modules/day** probing & assembly capacity.
- Sector assembly now scheduled at **1/ **4-days but present fixturing capable of **1/ **2-days
- Module and sector assembly rates can be increased withmore fixturing
- Plan for test and burn-in capacity to **exceed** assembly rate within cost constraints, because test capacity is not so readily expandable.

- M. Garcia-Sciveres - ATLAS Pixel Review - Module Assembly

## WBS 1.1.1.5.3  Production Schedule

- M. Garcia-Sciveres - ATLAS Pixel Review - Module Assembly

## Slide 16

- M. Garcia-Sciveres - ATLAS Pixel Review - Module Assembly

## Development Areas

- FE Wafers:  Probe bumped, Thin 8”, Mark die, 		 Stress test (wafer burn-in), Dummy wafers.
- Electrical Probing: Flex hybrid, Bare module.
- Flex Hybrid: Fab. Sources, Wirebonding.
- General: Assembly line issues (Q.C., monitoring, etc.),               Use dummy modules to address mechanical                 issues.

- M. Garcia-Sciveres - ATLAS Pixel Review - Module Assembly