26 September 2000

High Voltage Plates and Capacitors

Jack Fowler

26 September 2000Fowler Duke HEP

High Voltage Plate Procurement

Initial pre series received November 1999 We determined that the Kapton was too thick and redesigned.

Second pre series was received in May 2000 Traces on Kapton circuits exhibited cracks after flexing

New Kapton flex circuits ordered in July 2000 New High Voltage plates received September 2000

Currently evaluating changes

Remaining High Voltage Plates to be delivered in 2000

26 September 2000Fowler Duke HEP

High Voltage Plate

26 September 2000Fowler Duke HEP

Changes to HV Plate

Gold plating was removed from the traces, except for contact regions This was due to the thin layer of Nickel required under the

gold. It was causing the cracking. This was based on several recommendations from experts in

the field of circuit manufacture.

Increased radius and added chamfers to areas on thick plate where bending will occur This was based on recommendations from the manufacturer

of the Kapton material. (DuPont)

26 September 2000Fowler Duke HEP

Changes to Gold Plating

26 September 2000Fowler Duke HEP

Changes to Thick Plate

26 September 2000Fowler Duke HEP

Consequences of Changes

Due to the changes in gold plating, portions of the Kapton flex circuits had to be remanufactured Added 4 weeks to the delivery time Cost $15,000 for Type 1 and Type 2 HV Plates Type 3 was not affected because only pre-series was on order Thick plate changes had no effects on price

26 September 2000Fowler Duke HEP

Capacitor Procurement

Johanson X7R dielectric turned to “dust” after radiation testing at CERN

Identified alternative sources and dielectrics Samples have been sent to CERN for evaluation Expect 20 to 30 week lead time due to shortage in

electronics market How does this affect module production and

installation?