Method for fabricating thin film circuits on warped co-fired ceramic substrate

Abstract

The invention discloses a method for fabricating thin film circuits on a warped co-fired ceramic substrate in a polishing-free manner. The method comprises the following steps of 1), spraying the warped co-fired ceramic substrate with a BCB glue solution, and then performing solidification in a nitrogen atmosphere furnace according to a BCB solidification temperature curve; 2), spraying a solidified BCB medium layer with positive photoresist, exposing the positive photoresist over against a through hole column by using laser beams after pre-baking, performing development to remove the exposedpositive photoresist over against the through hole column, and performing post-baking on the photoresist; 3), etching a BCB medium by using oxygen / carbon tetrafluoride plasmas to expose the through hole column, and then removing a residual photoresist mask by using the oxygen plasmas or a photoresist removal solution; 4), based on the positive photoresist spraying and the laser beam photoetching,making a thin film circuit of a bottom layer; and 5), based on the positive photoresist spraying and the laser beam photoetching, making thin film circuits of subsequent layers.

Description

technical field [0001] The invention relates to a manufacturing method of a thin film circuit on a warped co-fired ceramic substrate. Background technique [0002] Co-fired ceramic substrate is a kind of multi-chip module (Milti-chip-module, MCM) packaging substrate developed to adapt to the high integration and miniaturization of electronic systems, that is, MCM-C packaging substrate, including low-temperature co-fired ceramics (LTCC) substrates and high temperature co-fired ceramic substrates (HTCC). Co-fired ceramic substrates have high integration and good heat dissipation performance, but the circuit accuracy, circuit density, signal delay, and high-frequency performance are not as good as thin-film circuits. Therefore, in order to improve the performance of the entire packaging substrate, thin-film circuits are fabricated on the co-fired ceramic substrate to form a co-fired ceramic-thin film hybrid packaging substrate, that is, the MCM-C / D packaging substrate. [000...

AI Technical Summary

Problems solved by technology

[0004] However, polishing the warped co-fired ceramic substrate will make the thickness of the dielectric layer on the surface of the substrate uneven, which will affect the high-frequency electrical performance, and even expose the internal metal wires, making the entire substrate scrapped; for co-fired ceramics Although the polishing of the substrate meets the needs of making precision thin film circuits, it will greatly weaken the adhesion at the interface between the co-fired ceramic substrate and the organic medium layer of the thin film circuit. The reliability of the ceramic-thin film hybrid packaging substrate plays a crucial role, while the bite force and low stress at the inorganic-organic interface brought about by the relatively rough surface play an important role in the adhesion at the interface

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