METHOD OF PRODUCING THROUGH HOLES WITH HIGH DENSITY ON FOIL POLYIMIDE FILMS WITH ADHESIVE SUBLAYER Russian patent published in 2024 - IPC H05K3/06 H05K3/26 H05K3/42 

FIELD: electrical engineering.

SUBSTANCE: invention relates to a method of opening contact pads on foil polyimide foil, and can be used in production of semiconductor systems, printed circuit boards or loops made on the basis of polyimide film. Obtaining through holes with high density on foil-coated polyimide films with an adhesive sublayer is the technical result, which is ensured by the fact that the etching solution contains, wt.%: monoethanolamine—20.4–71.26, alkali—30–50, tetramethylammonium hydrate or tetrabutylammonium hydrate—10–14, water—balance, wherein etching is carried out by frequent washing of the sample in concentrated sulfuric acid at temperature of 30–36 °C, followed by washing in distilled water at the same temperature as the etching solution, with carrying out visual control of change of color of polyimide film on transmission from orange to yellow, then further etching of the polyimide layer is carried out in monoethanolamine with addition of 10% KOH at temperature of 85–90 °C and periodic monitoring of the opening process.

EFFECT: disclosed is a method of producing through holes with high density on foil-coated polyimide films with an adhesive sublayer.

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