Comments and possible improvements

• A few paths are possible here
  1. Keep the paladium catalyst, but a new technique to remove the metalization inside the slits and outside will have to be developed.
  2. Remove the paldium catalyst and check if the metalization is good for our process
• Proposal for the next batch: 50% with paladium catalyst, 50% without catalyst
• Meeting with Rui on Monday:
  1. Chemical removal possible? How to make masks?
  2. Rui's metalization every time? Connectors acceptance check?
  3. More careful cleaning done by a tecnician in situ just before the metalization?

v6

• Nickel and gold bath are mixed with a big spatula
• DI water + brush cleaning
• Paladium activation (40s)
• DI water + brush cleaning
• Nickel chemical deposition 20 min
• Flash gold (10 min)

• First sample prepared by Rui (no bubbles)

• Second batch prepared by Giome (significant outgassing on the second melting, 1 connector soldered to grade-C, good X-ray)
• Kapton tape test on the back of the connector is OK. No delamination observed.

• It is a lot harder to remove the metalization near the edges. The edge of the connector is bended upwards and mouse bites structures are created due to the Nickel flakes coming off.
• The edge of the connector is bended upwards
• Mechanical removal is very trick and we would have to look for different tools.
• Chemical removal of the metalization seems the most appropriate process.

v5 CERN Mark

• Cleaning with detergent before the metalization
• Electroplating / chemical activation + Electroplating
• A few samples were tested. A significant outgassing was observed.

v4 CERN

• Metalization with Nickel chemical deposition 20 min
• Flash gold (10 min)
• Fluctuating metalization quality

v3 CERN

• Metalization with Nickel chemical deposition Nickel bath 15 min
• Flash gold (10 min)
• Fluctuating metalization quality

v2

• Second bath with thermocompact metalization showed substancial outgassing
• Most of the connectors were not usable for the soldering stack
• The process used was chemical deposition
• No further details of the process were given
• Low yield

v1

• Thermocompact metalization showed minimum to no outgassing during the soldering of the connectors
• The process used was chemical deposition.
• No further details of the process were given
• Extremely good results

-- OscarAugustoDeAguiarFrancisco - 2019-11-15