Surface-silvered polyimide (PI) film

due to the combination of the excellent thermal and mechanical properties of the polyimide matrix and the unmatched optical reflectivity and electrical conductivity of the surface silver (Ag) layer as well as as its light weight and flexibility

has been found widely attractive in aerospace and microelectronic industry and therefore has been extensively studied in recent years. In this review

we described the currently-used main techniques that were developed for the preparation of surface-metallized polyimide films

including external deposition

supercritical fluid impregnation

in-situ single-stage self-metallization

surface-modification ion-exchange self- metallization and direct ion-exchange self-metallization methods

and compared their advantages and disadvantages for producing the metallized polymer films. Particularly

the progress in the preparation of highly reflective and conductive surface-silvered polyimide films via the surface-modification ion- exchange self-metallization technique and direct ion-exchange self-metallization technique

both of which were developed in our groups

was summarized. With these two methods

double-surface- silvered polyimide films with high surface reflectivity and conductivity were produced by employing simple silver compounds as the silver precursor

which possess the advantages of processing simplicity and considerably reduced cost. Moreover

the finally-obtained polyimide-silver composite films were prepared with surface reflectivity over 100% and surface conductivity comparable to native silver metal. Excellent interfacial adhesion between the surface silver layer and the polyimide substrate was realized and the surface-metallized hybrid films basically maintain the essential thermal and mechanical properties of the parent polyimide. Especially

it should be emphasized that

with the direct ion- exchange self-metallization procedure

double-surface-silvered polyimide films could be realized by employing an aqueous silver ammonia ( [Ag(NH

3

)

2

]NO

3

) solution with a concentration of only 0. 01M and an ion-exchange time of merely 5min

which were demonstrated to be the most efficient film preparation route with the most economical silver usage.