Failure of electronic components-Passive element failures-pcb

- Feb 06, 2017-

Failure of electronic components-Passive

element failures-pcb

Passive element failures

Resistors

Main article: Failure modes of resistors
A resistor removed from a high voltage tube circuit shows damage from voltaic arcing on the resistive metal oxide layer.

Resistors can fail open or short, alongside their value changing under environmental conditions and outside performance limits. Examples of resistor failures include:

  • Manufacturing defects causing intermittent problems. For example, improperly crimped caps on carbon or metal resistors can loosen and lose contact, and the resistor-to-cap resistance can change the values of the resistor

  • Surface-mount resistors delaminating where dissimilar materials join, like between the ceramic substrate and the resistive layer.

  • Nichrome thin-film resistors in integrated circuits attacked by phosphorus from the passivation glass, corroding them and increasing their resistance.

  • SMD resistors with silver metallization of contacts suffering open-circuit failure in a sulfur-rich environment, due to buildup of silver sulfide.

  • Copper dendrites growing from Copper(II) oxide present in some materials (like the layer facilitating adhesion of metallization to a ceramic substrate) and bridging the trimming kerf slot.


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