Participants
- Salle 101: Taikan, Alice, Stéphane, Alexandre, Roman, Jérôme, Dominique
- Distance: Rémi, Vincent, Adrián, Jimmy, Jihane
Note: Main points have been noted, not necessarily in the order they were discussed.
Gluing
- Diagnotics
- Seen in 2018
- 2017
- PCB bending ➞ Picture on the assembly bench in Orsay showing a bend and delamination in a corner.
- The exact diagnosis has not been discussed by briefly been listed by Vincent:
- Delamination occurred on some ASUs since 2016, in a wide diversity of situations:
- After a plane transit (complete desoliderizing a single wafer)
- Full or Partial loss of connectivity PCB-Wafer,
- mostly on the borders (see right)
- Verified by measurement of the noise level
- Some connection were recovered by pressure (adding the tunsgten)
- Things are getting worse as time goes by
- Old (FEV10) or New (FEV13) boards affected
- Regluing of 2 single wafer was done in Kyushu (Picture attached)
- Removal of glue on the PCB quite clean.
- regluing satisfactory
- Possible causes:
- Materiel
- PCB's
- Bending ?
- measurement of old PCB could bring ideas.
- Heat FEV12
- Cabling: Process slow heat + peak + slow cool down
- idea: make PCB, equip with bad ASICs
- check mechanics
- measure the laser profile and /or tracer arm (Palpeur) profiles.
- Cabling
- Glue
- Contact with producers
- New producers ?
- Henkel
- Loctite ? < misinterpretation ?
- Change in composition culprit ?
- Old glue used in Kyushu : no diffreence
- Wafers
- Process
- Mixing of glue
- Done Manually
- Small quantities
- ➞ errors on composition
- Quantities: 4g / 2 ASUs
- Time: 1h
- viscosity change in 20 mins
- 2 ASUs max.
- Quantities
- Pas suffisante
- diameter points de colle ~ 2 mm
- Par pression ≥ Volume
- Sensor for visual inspection
- ~20k€
- Now: manual adjustment
- Surface quality
- Different histories
- Glue
- too long ?
- Viscosity ➚
- Garanteed for 6 months
- PCB
- Wafers
- Polymérisation
- Température suffisante ? temps suffisant ?
- Relâchement des contraintes AVANT polym. ?
- Will challenge the stability ➞ No fixed results
- Distance PCB vs Wafer
- 200 μm from ILD
- Release it ? To be seen...
- Environment
- Vibrations during transports
- Aging de la colle
- Temperature in stack ~ 40°C
- Banc climatique LLR, IJCLab
- Manipulation
- List of operation ?
- Calage dans les pièces dans les rails
- Calendier : début des soucis avec la nouvelle structure
- Force sur les bord ➞ pression au bords des cartes
- Ajout du W parfois en forçant ➞ pression externe au centre des cartes
- Fluctuation d'1 carte à l'autre
- Supports inégaux
- Bcp de manipulations
- Trop de manipulations...
- Mechanics
- Standard = flatness 1% of the diameters = 2mm
- Better becauce of symmetric design
- Actions
- Measure
- Laser
- Existing PCBs
- Wafers
- Instituts d'electronique
- 300€/20 Wafers
- Same surface
- Hamamatsu Kyushu
- Baby wafer
- For gluing mecahnica tests
- C2N2
- Aging/studies climatic measurement
- Vibration table
- Solutions
- Better gluing mixture
- Add a frame around pads:
- non-conductive glue (Taikan)
- plastic frame (Jerome)
- Measure of planeity before/after gluing ?
- Fabrication d'echantillons
- Vérification proprité mécanique du verre vs Si 500μm
- Verre sur QUELL PCB
- Fabrication de meilleurs supports
- sans contrainte du W sur les cartes
PCBs
Jerome
- Heat
- Footprint of connector
- Analogue probe
- 1 wire
- to the SLboard ADC input
- 1 already connected to AVDD
- ASIC by config
- only one by one
- Capacitance ➚
- use 0-Ω resistors to physically disconnect in case.
- Which line
- Read-register line unused (and some others ?)
- SOIC?
- HV
- Mechanical
- Small holes would be useful (Alice)
- for assembly / disassembly
- But there possibility to add 1-hole dominoes soldered on the boards for pliers.
- no more half holes (looking at the wafers)
- SLBoard
- Meeting on Wednesday (day after)
- 1 wire to be added for HV reconnexion.
-
Next meeting ≥ calice
Il y a un compte-rendu associé à cet événement.
Les afficher.
