Through-holes

Solder filled through-hole

Description:
Solder filled through-hole. There is too much solder at the walls of the through-hole. The successive placing of components could be considerably impaired. For a through-hole as such there is not enough solder. Partially acceptable defect.

Causes/Remedy:

  • deficiencies in the soldering process (soldering angle, temperature)
  • deficiencies in hot tinning for THD

überbelotete Durchkontaktierung Source:
Microsection

Description:
same context as described above - general view

Causes/Remedy:

  • deficiencies in the soldering process (soldering angle, temperature)

überbelotete Durchkontaktierungen Source:
visual, optical inspection - general view

Missing metallization

Description:
Thin metallization missing in a multilayer THD. Not acceptable

Causes/Remedy:

  • deficiencies in the galvanizing process (copper)

Durchkontaktierung mit mangelhafter Metallisierung Source:
visual, optical inspection - general view

Formation of burrs

Description:
Formation of burrs in the wake of drilling the boards. These residues of drilling which have not been removed (particles of base material, burr) were plated with copper in the successive electro-plating process and therefore block the passage. Not acceptable.

Causes/Remedy:

  • insufficient cleaning after drilling
  • drilling process not optimal

Durchkontaktierung mit Gratbildung in Bohrung Source:
Microsection

Description:
Same context as above, but to lesser extent.

Causes/Remedy:

  • insufficient cleaning after drilling
  • drilling process not optimal

Durchkontaktierung mit Gratbildung in Bohrung Source:
Microsection

Missing copper coating

Description:
Missing copper coating in a THD. Result: There is no surface to be wetted with solder. Not acceptable.

Causes/Remedy:

  • deficiencies in galvanizing process (copper)

Durchkontaktierung mit fehlender Kupfermetallisierung Source:
Microsection

Description:
Because of missing copper coating this THD solder joint could not be done properly. Not acceptable.

Causes/Remedy:

  • deficiencies in galvanizing process (copper)
  • hole reveals very uneven walls (unsatisfactory)

Durchkontaktierung mit fehlender Kupfergalvanisierung Source:
Microsection

Partly missing copper coating

Description:
Due to partly missing copper coating in the through hole the solder could not fully wet required area. Not acceptable.

Causes/Remedy:

  • deficiencies in galvanizing process (copper)
  • hole reveals very uneven walls (unsatisfactory)

Durchkontaktierung mit fehlender Kupferschicht Source:
Microsection
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