Brainwriting - DC Link by Alberto Catani

Customer complaint data, it is necessary to have a clear picture between the claimed parts and received parts from USA, vs China, and Europe.

alberto_catani — 2024-06-26 08:31:25 UTC

Customer data, it is necessary to have a clear picture about which plant in china, how many parts where produced (related to the claims) as well orientation to the steering gear.

alberto_catani — 2024-06-26 08:32:31 UTC

PCB quality

2024-06-26 08:34:43 UTC

including: E&E manufacturing issues every year from March till June

DC-Link root cause

2024-06-26 08:35:03 UTC

surface corrostion topic driven by oil during dispension

System impacts AL5/6 vs. AL7 different heat behaviour in ECU / on PCBA

2024-06-26 08:35:07 UTC

the measurement method with the customer is not alligned. Measurement off-line

alberto_catani — 2024-06-26 08:35:12 UTC

SWS process, 2 times SWS

2024-06-26 08:35:33 UTC

the measurement method is not alligned with the customer measurement method at our end of line.

alberto_catani — 2024-06-26 08:35:37 UTC

Handling on our plant or at the customer plant, this is why we see big regional differences

2024-06-26 08:35:47 UTC

the measurement method in our line is not repeating (V1)

alberto_catani — 2024-06-26 08:36:34 UTC

Climate conditions from ECU manufacturing till installing in the vehicle

2024-06-26 08:36:37 UTC

PCB delamination and electromigration due to selective soldering (incomplete or no thermal reliefs)

2024-06-26 08:36:44 UTC

Capacitor transportation, storage and assembly conditions

2024-06-26 08:36:46 UTC

the measurement method at our end of line is not reproducing (V3)

alberto_catani — 2024-06-26 08:36:52 UTC

DC-Link root cause

2024-06-26 08:37:07 UTC

in addition to oil, flux/unactivated flux residues and humidity needed

flux residues are suspected that Halogene contend has strong fluctuation in amount, which is by nobody controlled

Note: Accuracy of Measuring System at TK-Presta

2024-06-26 08:37:09 UTC

Note: Likely more then one factor (otherwise more frequent failure would happen)

2024-06-26 08:37:27 UTC

Oil separates from the gap filler due to an unknown reason during lifetime

2024-06-26 08:37:42 UTC

acts as carrier for ionic contamination

DC-link root cause

2024-06-26 08:38:26 UTC

R11 clearance of pads on the top surface is 3.5mm vs the clearance on R13 only 0.6mm. The difference is given because of the smaller pitch capacitor on R13.

Additionally NSMD pad design.

(original text:

Design impact, since R11 has 5mm distace between plus and mins in contradiction to 0.6mm bei R13)

HRI impacts to oil residues

2024-06-26 08:38:27 UTC

TK – P assembly processes (screwing,

2024-06-26 08:38:46 UTC

Motor and cover joining, flux at laser soldering

the corrossion location is related to the failure types A or B. Pending in how the corrosion is looking like, is the type of failure we are having.

alberto_catani — 2024-06-26 08:38:52 UTC

DC-Link root cause

2024-06-26 08:40:32 UTC

orientation in the tray (gear) during transport and time has an impact to the oil, which supports the corrostion

After long time all oil is in the pcg, therefore more or less no more occurance

Contaminated or damaged DC link directly from supplier, leaks electrolyte (source of ionic contamination)

2024-06-26 08:40:40 UTC

During the filling? Can it be overfilled?

Differences in PCB desing (based on EMS: FOx vs. IMI vs. CLS) - can even slight differences (closed / open Vias) either in crease or decrease the risk of the issue

2024-06-26 08:40:53 UTC

Corrosion should be completely avoided. A good Six Sigma project is required with the title " Elimination of corrosion in our ECU's after XX Months for the Products XX for our Customer XX".

alberto_catani — 2024-06-26 08:40:56 UTC

thermal paste amount

2024-06-26 08:41:11 UTC

thermal paste variant

2024-06-26 08:41:29 UTC

DC-Link root cause

2024-06-26 08:41:38 UTC

Design of spacer (rubberendcap) of DC-link is more favourable at R11 for not occurance. Rrubber plug on R13 acts as a contamination collector

DC-Link root cause

2024-06-26 08:42:20 UTC

oil is weaken rubber cap of Capacitor, electrolyte can penetrage to pcb

DC-link root cause

2024-06-26 08:43:22 UTC

mechanical strain can release elektroylte from cap and lead to surface corrosion

comment: during handling and mating

Glue pot time is too long, further increases mating forces

2024-06-26 08:45:17 UTC

check all EMS processes in traceability

Any other not known (by tk) not compatible material used @EMS

2024-06-26 08:46:01 UTC

from Tamás

Thermal glue amount & viscosity

2024-06-26 08:52:20 UTC

from Tamás

CAF

2024-06-26 08:53:37 UTC

from Tamás