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Separation of metallization from component

Appearance
Disturbed, non-conforming solder fillet due to considerable separation of metallization

Separations at CMCs

Description:
Distinct separation of the contact metallization of a CMC 1206. The metallization had been completely wetted, but it was separated by the liquid solder in the wave soldering process, so that only a small portion of the contact metallization was present for the solder joint. This leads to insufficient solder fillets or even opens. The component has to be replaced. Observe the best solder parameter (soldering tip temperature </= 360 °C)

Causes/Remedy:
  • faulty structure of the contact metallization of the component
  • unfavourable soldering parameter: soldering time too long, solder temperature too high

Source: SEM
Separation at a CMC

Separation at a CMC

Separations at QFP

Description:
Separation combined with bad wettability of the face and sides of the QFP gullwings. The wettability problems can be traced back to the material (Alloy 42). The parts where solder could just adhere to the gullwings (middle) are clearly visible. Thanks to the intact solder joint at the heel and the wetting of the undersides rework in this case is not necessary.

Causes/Remedy:
  • components too old
  • unsuited metallization / basic material

Source: SEM
Separation at a QFP

Separation at SOD

Description:
Separation of the contact area of a SOD. It is clearly visible that the solder fillet is therefore insufficient. The component must be replaced. Observe suitable solder parameter. (soldering tip temperature </= 360°C).

Causes/Remedy:
  • faulty structure of the contact metallization of the component
  • unfavourable soldering parameter: soldering time too long, solder temperature too high

Source: visual, optical inspection - general view
Separation at a SOD

Separation at a bi-polar component (resistor, block-shaped)

Description:
Separation of metal at the front end of a component leads to an unacceptable solder fillet (bottom right). The component must be replaced. Observe suitable solder parameter. (soldering tip temperature </= 360°C).

Causes/Remedy:
  • faulty structure of the contact metallization of the component
  • unfavourable soldering parameter: soldering time too long, solder temperature too high

Source: visual, optical inspection - general view
Separation at a resistor
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