CMS Tracker MPR, CERN, 22 November 2004 22 Nov 2004CMS Tracker MPRSalvatore Costa - Catania Module Bonding Working Group Salvatore Costa Università di

CMS Tracker MPR, CERN, 22 November 2004

22 Nov 2004CMS Tracker MPRSalvatore Costa - Catania

Module BondingWorking Group

Salvatore CostaUniversità di Catania and INFN – Sezione di Catania



Bonding Facilities

22 Nov 2004CMS Tracker MPR 3 Salvatore Costa - Catania

Bonding Machines

Center Bonding Machines available to CMS

Bari Delvotec 6400

Catania Hughes 2470-II (1+1)

Firenze Delvotec 6400

Padova Kulicke&Soffa 8090, Kulicke&Soffa 4123, Hughes 2470-V

Pisa Kulicke&Soffa 8090

Torino Delvotec 6400

Fermilab Kulicke&Soffa 8090 (3)

Santa-Barbara Kulicke&Soffa 8090, Kulicke&Soffa 8060

Aachen Hesse&Knipps 710M

Hamburg Delvotec 6400

Karlsruhe Hesse&Knipps 710M

Strasbourg Delvotec 6400

Vienna Kulicke&Soffa 4123

Zurich Delvotec 6319, Delvotec 6320


Bonding Times per Module• Pre-bonding visual inspection: 10min• ARC test: 15-30min• Bond: 5-35min

» 5min for K&S» 10min for Delvotec and Hesse&Knipps Double for 2-Sen Modules » 35min for Hughes.

• Post-bonding inspection: 10min• Pull test [if required] (pull, cleanup, rebond): 20min• DB entry: 5min

TOTAL: 45-90min excluding pull testTOTAL: 45-90min excluding pull test

NOTES: 1. ARC test times vary with Vpsp adjustment2. Some op may be performed in parallel by different people


DB Interface


Bonding WG Web Site



Production Rate


Production Rate



Bonding Failures & Repair Actions


Maintenance, Failures, Downtime Center Maintenance schedule Failures Downtime

TIB: Bari ~yearly, no contract No N/A

Catania on demand,no contract Once 1 month (*)Firenze yearly by contract 2 times 2 months (*) Padova regularly by bond op. No N/APisa by bond op. as needed No N/ATorino ~yearly, no contract No N/A

TEC:Aachen regularly by bond op. No N/AHamburg on demand,no contract Once 3 days Karslruhe on demand,no contract Once 1.5 daysStrasbourg yearly by contract No N/AVienna yearly by contract No N/AZurich on demand,no contract Once 2 weeks

TOB:FNAL 4/year by contract Damage by None

power failures UCSB 4/year by contract 1/machine ~1-2 week/machine

(*) Attempts (failed) to fix in house, to save money, made because prod was stopped


Bonding Failures/Rep Actions1. Bonding failure detected during bonding or at post-bonding inspection:

– Wire won’t stick – Bond pops up (lift off) – Foot is misplaced and causes a short somewhere

We repair these right away if we can and/or list as unbonded the strips that are such as a result of the failure or of the “repair” action.

2. (Bonding) failure detected during post-bonding ARCS or LT tests:– Pinhole (caused by bonding/handling accident or pre-existing and either undetected in Sensor

test or on untested Sensor)– Short (caused by bonding/handling accident or by misplaced foot)– Open (bond popped up)

Same action.

3. Electric failure detected with ARCS at any stage (pre-bonding, post-bias-pre-readout-bonding, post-bonding or LT tests which dos not exhibit a clear link to bonding:

– Increased LV current – Anomalous IV

We post the problem for the Debug/Repair Center

4. Electric failure detected during post-bonding ARCS or LT tests, which might be traced back to a bonding failure:

– Example: “pseudo”-pinhole: At post-bonding ARCS test, a “PHL-” is found. We pull the readout bond as prescribed for pinholes but the test keeps saying “PHL-”, so the Hyb ch is damaged. Since it was OK at ARCS test on arrival perhaps we killed it with bonding.

We post the problem for the Debug/Repair Center.


Bonding Failure Rates• Global percentage of damaged channels (Hyb ch and/or Sen

strips) because of bonding failures: <~0.01 %<~0.01 %– Based on a compilation of unrepairable bond failures reported by individual

centers on 20Apr2004. At that time 1180 Modules had been bonded (~800,000 bonds).

– Since then reports at Meetings have indicated improvements, therefore although a more recent quantitative estimate is not available, it can only be less.

– Global percentage is the average between 0 from a few centers (such as Pisa) were not a single bond failure leading to loss of channels has been observed and 0.08 % in Catania [see next slide for analysis of failure types] where the oldest bonding machines, also lacking modern amenities such as automatic correction of bond parameters with varying substrate quality, are.

• Not a singleNot a single module lost yet (i.,e. no module with > 2% affected channels) because of bonding failures out of 2,700 Modules bonded so far.

• Only 1 module unbondable for dirty Pitch Adapter.


Bond Failure Analysis (Catania) 53 Modules

34048

bonds

Unrepairable failures

# modules affected % # channels affected %

Totals 10 19 29 0.08

Machine failures

7 13.2 14 0.04

Bond foot misplacement

2 3.8 9 0.026

to stick 4 7.6 4 0.012

Pinholes (caused by bonding?)

1 1.9 1 0.003

Operator mistakes

3 5.7 15 0.04

Mishandling 2 3.8 7 0.02

Wrong ref

Wrong par

(lifts, pinholes)1 1.9 8 0.02



The chief Bonding quality indicator:the Pull Test


Module Pull Tests Performed

# Modules pull tested # Modules pull tested after 01Dec2003 (at last Mtg)after 01Dec2003 (at last Mtg)

Center PA TA PA-Sen Sen-Sen

Bari 98 (83 ) 101 (86) n/a

Catania 51 (51) 51 (51) n/a

Firenze 9 (9) 5 (5) n/a

Padova 18 (18) 99 (99) n/a

Pisa 18 (10) 46 (37) n/a

Torino 119 (114) 46 (46) n/a

Fermilab 121 (119) 35 (33) 35 (34)

Santa-Barbara 51 (51) 58 (58) 76 (76)

Aachen 37 (0) 41 (0) 41 (0)

Hamburg 69 (62) 50 (45) n/a

Karlsruhe 0 (0) 20 (20) n/a

Strasbourg 20 (20) 65 (65) 65 (65)

Vienna 55 (19) 91 (28) n/a

Zurich 0 (0) 42 (38) n/a


Pull Test Results (Nov ‘04)

BA CT FI PD PI TO FL FL SB SB AA AA HA KA ST ST VI ZH

. ss ss ss ss

5g

Not angle-corrected yet!

Ave

rag

e f

orc

es (

g)


Pull Test Results (Jul ‘04)

Readout bonds

0.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0

16.0

18.0

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Av

era

ge

fo

rc

es

(g

)

01Dec-06Jun

07Jun-18Jul

BA CT FI PD PI TO FL FL SB SB HA KA ST ST VI ZH

. ss ss ss

5g

Not angle-corrected yet!


Readout bonds

0.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0

16.0

18.0

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Av

era

ge

p

ull fo

rc

e (g

)

01Dec-18Apr

19Apr-06Jun

Pull Test Results (Jun ‘04)

BA CT FI PD PI TO FL FL SB SB HA KA ST ST VI ZH

. ss ss ss

5g


Loop Documentation

Procedure: Uses a few of the identical symmetrical bonds we place on the PA Tests areas.1. Document the original bond

2. Straighten a bond to (near) triangular shape

3. Measure the angle at the bond foot

4. Determine correction factor for pull strengths


1. Document the original bond

• Gently push bond over with the pull tester hook until it rests flat on the PA surface, but taking care that its shape is not significantly altered.

• Take snapshot of bond under measuring machine.


2. Make bond triangular• Gently pull bond up at mid-span with the pull tester hook until it takes a

(nearly) triangular shape (figure below).

• Gently push bond over with the pull tester hook until it rests flat on the PA surface, but taking care that its now triangular shape is not significantly altered.


3. Measure angle at bond foot

• Take snapshot of triangularized bond.• Measure angle using measuring machine.


4. Determine correction factor (1)


4. Determine correction factor (2)

Correction factor:a = 1 / (2 sin)

(º) corr. factor a

10 2.88

20 1.46

30 1

40 0.79

50 0.65

60 0.58

70 0.53

80 0.51

90 0.5

For symmetrical bond:



Module Gradingfrom Bonding


Module Grading from Bonding (1)

Grading based on # unbonded stripsGrading based on # unbonded strips

• First flag in BONDSTATUS_VALBONDSTATUS_VAL vector:– 0 if n_unbonded <1– 1 if 1% - 2– -1 if >2%

• These are consistent to grades A,B,C of ModTest and the module is faulty with >2% unbonded strips.


Module Grading from Bonding (2)

Grading based on Grading based on mechanical quality of the bondsmechanical quality of the bonds

• Criteria to generate this second flag:– # Bias Bonds (Spec: 5, 15 for TIB back)

• >2: grade A (flag 0)• 2: grade B (flag 1)• <2: grade C (flag -1)

– # “critical” readout bonds [definition list of “critical” by Alan]: • ≤ 2%: grade A (flag 0)• > 2%: grade B (flag 1)• > 20%: grade C (flag -1)

– Operator judgment on all other bonds [guidelines to issue this judgment by Alan]:

• A, B, C.

• These criteria will be or’ed together to generate flag.



Bonding Specifications & Procedures


Bonding Specs (1)

• Document on Bonding web site:

cms.ct.infn.it/bonding/bondspec.htm• Contents:

– Bonding Specifications … – Specifications on Bonding Jigs – Specifications on Module Carriers – Specifications on Module Components and Assembly

Relating to Bonding – Specifications on Working Environment – Specifications on Final Module Bonding Quality &

Acceptance


Bonding Specs (2)

• wire thickness and type• number of bias bonds• loop height and form• tail length• accuracy of placement in X and Y• pull strength• break on pull failure• failure rate• number of bonds with one tool


Bonding Procedures

• Bonding Proc Document on Bonding web site:

cms.ct.infn.it/bonding/bondproc.htm– “Reference” doc in 43 steps– Has many pictures (mainly for TIB at the moment)

• Procedure to perform the 50th wire Pull Tests

cms.ct.infn.it/bonding/pullproc.htm


Skip rules

• Leave unbonded– All strips in bad-IDIEL list

(considered pinholes)

– All Isolated bad CAC (believed to have high chance to develop into pinholes with irradiation)

– All but lowest in a bad CAC chain (believed to represent shorts)

CAC Example: 3 34 35 36 37 skip isolated 3,

skip all but lowest in 34-37 chain, or: bond only 34

• Leave unbonded all strips in bad-IDIEL list (although 16 % are good), i.e. do not bother looking at their actual IDIEL value.

• Bond all isolated bad-CAC • For the consecutive bad-CAC,

compute rC and consider them members of a short if rC>1.5. Then bond only the first strip in the short.

• If rc<1.5 bond them, as if they were isolated

Documents

CMS Tracker MPR, CERN, 22 November 2004 22 Nov 2004CMS Tracker MPRSalvatore Costa - Catania Module Bonding Working Group Salvatore Costa Università di