1. Capacitor Assembly K. McFarlane 9/30/02 9/30/2002 TRT meeting Oct 2002
CERN

2. Task
Assemble 18,000 capacitor assemblies, consisting of socket, capacitor, bent pin
Coat with protective coating
9/30/2002
TRT meeting Oct 2002
CERN

3. General Concept Batch process in two phases:
Phase 1: Solder reflow in jig
Phase 2: Coating
Number in batch: 100 – 500
Initial experiments on phase 1 promising; phase 2 not yet tried
Note: final choice of capacitor not made.
9/30/2002
TRT meeting Oct 2002
CERN

4. Phase 1 steps Place capacitor and socket in jig
Apply solder paste to ends of capacitor
Add bent pin
Pass jig through reflow cycle
Ultrasonic clean with water
Dry in oven at ~60 °C
4/30/02: Changed to plurals in 1, 2, 3 and changed text to red, to emphasize serial nature of steps.
9/30/2002
TRT meeting Oct 2002
CERN

5. Initial Experiments Use clay jig (~180°C max temperature)
Johanson 202S43W102KV4E capacitor
Custom socket (Duke)
Standard Mill-Max pin, bent
EFD Sn42 or Sn43 solder paste
Max reflow temperature 190 °C
Rate of change of temperature <2 °C/s
9/30/2002
TRT meeting Oct 2002
CERN

6. Assembly tooling Oven with jig and thermocouple
Application of solder paste to capacitors in jig.
9/30/2002
TRT meeting Oct 2002
CERN

7. Finished products
9/30/2002
TRT meeting Oct 2002
CERN

8. Possible Fragility?
The design with the pin on the side seems fragile. This geometry is intended to fit under the electronics. With the pin on the side, the overall height is ~ 7mm. On top, it would be ~ 7.5mm.
9/30/2002
TRT meeting Oct 2002
CERN

9. Production times 20 seconds per assembly to fill jig
25 minutes for reflow cycle
15 minutes for cleaning (inc. database)
With 5 jigs and 100 per jig, 124 hours for 18,000 assemblies. With a single jig, 220 hours.
Coating time not estimated.
9/30/2002
TRT meeting Oct 2002
CERN

10. Plan for coating Plan to try Stycast 1266 first
Find a batch coating process. May require release agent or peelable coating
Would likely involve an oven cure, perhaps at 100°C
Suggestions welcome for coating material
9/30/2002
TRT meeting Oct 2002
CERN

11. END
9/30/2002
TRT meeting Oct 2002
CERN