CMS Week, CERN, 07-11 June 2004

08 Jun 2004CMS Week - Bonding WGSalvatore Costa - Catania

Documentation of the loopof the to-be-pull-tested bonds placed

in the PA Test areasin Catania

Salvatore CostaUniversità di Catania and INFN – Sezione di Catania

08 Jun 2004CMS Week - Bonding WG 2 Salvatore Costa - Catania

Procedure

Uses a few of the identical symmetrical bonds we place on the PA Tests areas, currently pull-tested on a sampling basis.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

08 Jun 2004CMS Week - Bonding WG 3 Salvatore Costa - Catania

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 Mitutoyo measuring machine.

08 Jun 2004CMS Week - Bonding WG 4 Salvatore Costa - Catania

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.

08 Jun 2004CMS Week - Bonding WG 5 Salvatore Costa - Catania

3. Measure angle at bond foot

• Take snapshot of triangularized bond under Mitutoyo.• Measure angle with Mitutoyo.

08 Jun 2004CMS Week - Bonding WG 6 Salvatore Costa - Catania

4. Determine correction factor (1)

08 Jun 2004CMS Week - Bonding WG 7 Salvatore Costa - Catania

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:

CMS Week, CERN, 07-11 June 2004

08 Jun 2004CMS Week - Bonding WGSalvatore Costa - Catania

Salvatore Costa

Bondingin

CATANIA

Università di Catania and INFN – Sezione di Catania

08 Jun 2004CMS Week - Bonding WG 9 Salvatore Costa - Catania

Catania: bond accounting

Module Type IB34 IB12phi Total

Received from Gantry

71 34 105

Bonded 45 33 78

ARC tested 44 33 77

OK 44 31 75

bad 2 2

08 Jun 2004CMS Week - Bonding WG 10 Salvatore Costa - Catania

Catania: (bond) faults

• 2 Modules (30200020035289, …303) fail ARC Fast Tests Low Voltage test: I(V2.50)=804 mA (max 750 mA)Still not understood

• 1 Module (30200020035305) can’t power up 2 APVs – Damage to connector? False alarm: misplugged connector

• In one recent group of 11 modules (bias bonded, readout not bonded yet), 5 anomalous IV curves

08 Jun 2004CMS Week - Bonding WG 11 Salvatore Costa - Catania

Catania: new tool type

• We reached more than 40,000 bonds with one tool

• Changed tool and tool type to one suggested by Palomar Tech engineer– Designed specifically for

Hughes (Palomar) 2470 wedge bonder

• Last (1) Module bonded with new tool– Par not yet optimized– Much higher pull forces (13-

15g), but lift-offs/cratering