Deutsch

Alignment deficiencies at CMC

more examples

Description:
Example of end and side overhang of CMCs. The two examples on the left are acceptable and represent Class A of IEC 61191-2. The two examples on the right are nonconforming.

Causes/Remedy:
  • placing faults: teaching, tolerances, systematic faults
  • floating of components during reflow process
  • vibration during soldering


Source: SEM
Alignment faults of CMC

Description:
A CMC was placed with its side up. This defect does not impair function and is acceptable according to Class A of said standard. For higher requirements (Class B and C) this defect is not acceptable and has to be reworked.

Causes/Remedy:
  • placing fault (incidental)
  • seldom: vibration during transport of assemblies


Source: visual, optical inspection - general view
CMC placed with side up

Description:
Twisting of a CMC after wave soldering; same context as described in the main file on deficiencies in component alignment. The component left its place due to insufficient adhesive force. Rework is necessary.

Causes/Remedy:
  • poor adhesive application
  • adhesive insufficiently hardened
  • poor soldering parameter


Source: visual, optical inspection - general view
Alignment fault of a CMC - CMC twisted
back
ContactReferencesDisclaimerfacebook logogoogle+ logoyoutube logo