Fields of activity

Chip-Film Patch (CFP) technology

Process to manufacture hybrid systems-in-foil with integrated ultra-thin silicon chips

Hybrid Systems-in-Foil with integrated ultra-thin silicon chips set the ground for a new generation of mechanically-flexible electronic systems. A precondition for the manufacture and handling of ultra-thin ICs (with a thickness < 50 µm) as well as technologies for the integration of thin chips and other components in flexible electronic systems. Using the Chip-Film Patch (CFP) process silicon chips are embedded in and connected to flexible foil.

Ultra-thin silicon chips are manufactured by thinning wafers. Good results for a 20 µm thickness can be achieved by using the Dicing-Before-Grinding (DBG) process which includes etching trenches into the wafer prior to separating the chips in a multi-level grinding process.

The Chip-Film Patch (CFP) process developed at the IMS is a wafer-based technology that embeds applied polymer layers. The layer system made of benzocyclobutene (BCB) and polyimide serves as dieelectric and foil substrate, the metalization is achieved through sputtering or depositing aluminum. Using photo-lithographic techniques structural widths of only a fews micrometers can be achieved. The outer connect pads to connect to the precious metal connections can be fitted with gold among else. The foil system with a thickness of 60 – 80 µm is very flexible after it´s extracted from the carrier wafer.

Cross-section of the Chip-Film Patch (CFP)

Flexible system with integrated RF chip and antenna (5-6 GHz) in the high-frequency CFP

The placement accuracy of the singled thin chips limits the possible minimal structural size of the connecting pads. Only a maskless exposure process allowing an individual adjustment of the layouts to the chip position (adaptive layout) enables the connection to reliable small structures. By exposing structures onto the resist using a UV laser laser direct writing is feasible.

(FFlexCom project is a Deutsche Forschungsgemeinschaft (DFG) project with grant-no. BE 2256/25-1)

CFP foil on gripper

Combining printing techniques and organic electronics creates intelligent and autonomous, adjustable and flexible sensor systems. Application demonstrators used in industrial automation and robotics develop and test these technologies. Bending and stress sensor systems for a bionic gripper guide, tamper-proof door monitoring, Industrie 4.0 applications and sensor systems for medical applications are just some examples of the application scope. The KoSiF project image shows a CFP foil mounted on a gripper with integrated bending sensor ASICs and a radio chip, antennas and organic electronics.

For further information, please contact: Christine Harendt