Status of the large scale cooling test

1
Status of the large scale cooling test

• 4 cooling meanders glued to the MCM mockup
• Heat conducting grease applied between the
  cooling pad and glob top
• Glob top layer uneven this is not the case on
  real MCM
• T measured in 8 points

2
Temperature measurement
8 x Pt 100 sensors contacted using the thermal
compound
Tout
Treg pad
Tmcm8 pad
Tmcm4 pad
Tin
Tmcm4 board
Tmcm8 board
Treg board
Setup operaded in closed volume 20mm between
the two chambers with isolated sides
3
Voltage regulator cooling

• Cooling the top of Vreg is insufficient need
  for a heat bridge and max. contact length with
  cooling pipe
• Several designs tested
• Design with pad soldered to the ground pin of
  Vreg most promising el. isolation between
  cooling pad and pipe needed

A
B
C
4
Measurements

• Without cooling Treg under PCB reached 100 deg.
  in several minutes
• With cooling (flow 13.3 l/h per board 1.52 m3/h
  per SM , D p 150 mbar, 16 deg. inlet water)
  can be PCB under MCM cooled to 26-27 deg. (uneven
  glob top!!), MCM pad 16.2-18.5 deg. PCB under
  Vreg 40 deg. (Vreg heat bridge A) D Twater
  0.3 deg.
• With Vreg cooling (heat bridge B) (flow 5 l/h,
  D p 50 mbar, T inlet water 15 deg.) and power
  dissipation (D V 0.7 V, I 800 mA) only under
  the Vreg T 30 deg. , no heating up of the PCB,
  cooling can cool PCB below the room temperature
  (25.1 deg) to 21.4 deg.
• Vreg cooling (heat bridge C) (flow 5 l/h, D p
  50 mbar, T inlet water 14.2 deg.) and power
  dissipation (D V 0.7 V, I 800 mA) under the
  Vreg T 24.3 deg. , cooling can cool PCB below
  the room temperature (25 deg) to 19-20 deg.

5
Next steps

• Check how depends D T board-pad on quality of
  glob top surface
• What is the intrinsic D T due to glob top and how
  depends on thickness
• In small scale test MCM cooling worked OK
  problem most likely in glob top surface

6
Super Module mechanics

• Added main services along the SM fixation to SM
  wall
• Design of the end-plate connectors piping
• Space for DCS LV distribution board defined
• Victor prepared first set of drawings

7
Victor's design

• Add details of the end-section
• Add cooling sub-manifolds
• Improvements in stability