1. GlueX Electronics Review Jefferson Lab July 23-24, 2003
R. Chris Cuevas
Physics Division
Group Leader -- Fast Electronics
Topics:
Printed Circuit Board Manufacturing
Maintenance
Power & Grounding
9/18/2018
GlueX Electronics Review --R.C. Cuevas

2. GlueX Electronics Review --R.C. Cuevas
PCB Manufacturing
JLAB Electronics Group & GlueX collaborators have extensive experience with design and ordering PCBs in industry.
PCB is not a mechanical part!
Electrical characteristics more important than mechanical tolerances
Design Tools are essential for verification
We have PCAD, Gerber View Tools but,,,
More extensive simulation tools would be useful
(e.g.) PCB layout simulation, signal integrity modeling
9/18/2018
GlueX Electronics Review --R.C. Cuevas

3. GlueX Electronics Review --R.C. Cuevas
PCB Manufacturing
1000’s of custom PCBs have been manufactured in industry for CLAS. [Drift Chamber, Level II Trigger, Timing distribution]
Typical PCB development ‘procedure’
Design requirements -- Specifications/Format
EECAD -- Schematic capture -- Board layout
Prototype ordered -- Assembled on site
TEST -- Verify circuit performance -- Record results
Capture all ECOs [ Engineering Change Order ]
9/18/2018
GlueX Electronics Review --R.C. Cuevas

4. GlueX Electronics Review --R.C. Cuevas
PCB Manufacturing
‘Procedure continued’
Verify all ECOs in new layout
Prepare order for contract manufacturing & assembly
Evaluate manufacturers -- Not on price alone!
Long term reputation/experience
Documented Quality Control standards [ IPC,ISO ]
Automated assembly equipment
Bare board test equipment
1st Article assembly very important
9/18/2018
GlueX Electronics Review --R.C. Cuevas

5. GlueX Electronics Review --R.C. Cuevas
Maintenance
No glamour, but planning NOW is critical for high availability
Must plan for spare PCBs for each custom design
Crucial components must be identified
Spare devices purchased for long term replacement
DOCUMENTATION -- Must archive and provide on-line
Schematics
System/Wiring Diagrams
Maintain Firmware Development Tools and Code
Test Programs
9/18/2018
GlueX Electronics Review --R.C. Cuevas

6. GlueX Electronics Review --R.C. Cuevas
Maintenance
High Availability Demands:
Low Mean-Time-to-Repair
Example: Powered Card Enclosures [ “Crate” ]
Removable power supply units
Removable fan tray
Easy access to circuit boards -- test points
Remote monitoring of “Crate” systems -- V, I, Temperature
Remote reset feature where applicable
9/18/2018
GlueX Electronics Review --R.C. Cuevas

7. GlueX Electronics Review --R.C. Cuevas
Maintenance
Planning for the repair “shop”:
Must provide training for technicians on new designs
Test “Stations” for all custom and commercial boards
Ability to repair/rework circuit cards, power supplies
Assure proper tools and test equipment are provided
Establish circuit board calibration/repair/tracking database
Use new technologies for keeping track of all modules in the experiment. [ RF Id,, Bar code ]
9/18/2018
GlueX Electronics Review --R.C. Cuevas

8. GlueX Electronics Review --R.C. Cuevas
Power & Grounding
Very extensive topic and,
We have good experience with Hall B [ CLAS ]
Careful planning of power isolation and grounding grid
Extensive review of AC Mains requirements
Must include grounding grid requirements for Accelerator connection and civil engineering
Must identify all large “consumers” of AC Mains
Superconducting Magnet system
Building utilities [ HVAC, LCW, Pumps, Crane ]
Front End Readout crates
High Voltage systems
9/18/2018
GlueX Electronics Review --R.C. Cuevas

9. GlueX Electronics Review --R.C. Cuevas
Power & Grounding
9/18/2018
GlueX Electronics Review --R.C. Cuevas

10. GlueX Electronics Review --R.C. Cuevas
Power & Grounding
Reasons for Grounding
Shock and Safety Hazard Control
Reduce lightning related gradients
Avoid injury to personnel
Avoid damage to Electrical/Electronic equipment
Establish return reference
EMI control
Shield reference for cables, isolation transformers
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GlueX Electronics Review --R.C. Cuevas

11. GlueX Electronics Review --R.C. Cuevas
Power & Grounding
Learn from omissions: [ CLAS example ]
Plan for dedicated network conduit(s)
High speed network gear & beam-line diagnostic
equipment not in close proximity to detector power supplies
Low radiation levels in Hall D
Should allow extensive use of Fiber Optics for
Communication links --
Data acquisition --
Optical isolation for control circuits where applicable
9/18/2018
GlueX Electronics Review --R.C. Cuevas

12. GlueX Electronics Review --R.C. Cuevas
Summary
PCB Manufacturing
Excellent design record.
Almost zero problems with production PCBs in CLAS
New design/verification tools would be beneficial
Maintenance
Electronics Group is a small [ efficient ] group
Large portion of readout electronics for CLAS and other Halls are mostly commercial [aging] electronics
Custom electronics will demand better tracking, repair and long term availability of crucial components
Power & Grounding
Careful review of AC Mains requirements NOW
Requirements for detector power supplies, HV, Front End crates need to be established,,,
Grounding/shielding configuration is crucial for low noise measurements and reducing EMI pickup
9/18/2018
GlueX Electronics Review --R.C. Cuevas