1. Field of the Invention
The invention is directed to a method for manufacturing an electronic component, particularly a SAW component working with surface acoustic waves, comprising a chip with piezoelectric substrate and an active filter structures that are contacted to interconnects of a base plate, and comprising a cap-shaped housing that envelopes the chip and is tightly seated on the base plate.
2. Description of the Related Art
For protection against disturbing environmental influences, particularly against chemically. Aggressive substances and moisture, a potentially multi-layer and after layer insert usually 2-layer, structured protective films, (Protec) by the assignee, is arranged between a base plate and a chip given active filter structures contacted to the ceramic or plastic base plate in flip-chip technique,xe2x80x94i.e. with bumps or, respectively, solder balls. Protected by this film, the SAW filter can have a casting compound, for examplexe2x80x94epoxy resin, filled under it and cast around it after the flip-chip bonding without the active filter structure being thereby coated and the surface waves being undesirably attenuated.
For SAW filters of the ultra-frequency pass range that are contacted in flip-chip technique, i.e. typically given chip dimensions less than approximately 2xc3x972 mm2, it has been shown that an adequate stability given alternating temperature stressing is established even when the corresponding spaces between base plate and
As a result of observation, the object of the invention is to specify a method that enables the eliminate of the expensive PROTEC encapsulation of the SAW components and that nonetheless produces excellent SAW components.
For achieving this object in a method of the species initially cited, the invention provides that a carrier plate that can be separated into base plates is respectively provided with interconnects in the base plate regions, that one chip per base plate region is contacted to the interconnects thereof in flip-chip technique, that a cover film, particularly a metal foil or a potentially metal-coated plastic film, is applied onto the chip-equipped carrier plate, that the cover film is treated, (e.g.xe2x80x94heat and pressure treated,) such that it envelopes each chipxe2x80x94except for the chip surface facing toward the carrier platexe2x80x94and lies tightly on the carrier plate surface in regions between the chips, and that the carrier plate is separated into the individual SAW components.