In historical linguistics and language contact, unpacking is the separation of the features of a segment into distinct segments. Wikipedia

The separation of the features of a segment into distinct segments Wikipedia Disambiguation

phonological process where a segment's features are split into multiple segments Wikidata

The separation of the features of a segment (such as a nasal vowel or palatal consonant) into distinct segments; for example, the separation of a nasal vowel such as /ɑ̃/ into a vowel /ɑ/ and a nasal consonant /n/ (i.e., into /ɑn/) which often occurs when a language which does not use nasal vowels borrows from a language which does use them. Wiktionary