Johannes Wilhelmus Weekamp

Method of producing a multilayer piezoelectric element

A method of producing a multilayer piezoelectric element. The multilayer is formed of layers of piezoelectric synthetic resin material, such as PVDF and metal layers, such as Al. The multilayer is made form-retaining and mechanically stable by use of heat and pressure. Connections are provided on two facing sides of the multilayer which preferably include at least one sprayed metal layer, which preferably consists of the same metal as the metal layers of the multilayer.

From zero- to second-level packaging of RF-MEMS devices

This paper reports the full packaging and assembly of RF-MEMS devices for operation below 6GHz, comprising 0-level, 1-level and 2-level packaging. The fabrication process for the RF-MEMS devices is based on the Philips PASSI/spl trade/ process, which is adapted to accommodate the packaging. The 0-level assembly is based on solder bonding, and is realized on a flip-chip aligner/bonder under atmospheric pressure, at 240/spl deg/C. The 1-level package comprises a chip-scale-package (CSP) in which the 0-level packaged device is directly equipped with solder balls for the interconnect. The individual 1-level assemblies are then flip-chip mounted on a RF-board at 240/spl deg/C, completing the 2-level packaging. RF measurements of a 2nd-level packaged series switch showed an increase of the insertion loss of about 0.1 dB after 0-level packaging, increasing to about 0.5dB after 2nd-level packaging. Preliminary evaluation of the 0-level package hermeticity using switches configured as mechanical resonators indicates an hermetic seal.

MEMS tunable capacitors and switches for RF applications

RF MEMS capacitive switches and tunable capacitors have been realized in an industrialized thin-film process developed for manufacturing high-quality inductors and capacitors. Combining integrated passives with high-performance tuning and switching elements on the same die offers a potential for building a new generation of RF front-ends for hand-held mobile communication. Capacitive switches with an insertion loss of 0.4 dB and an isolation of 17 dB at 1 GHz have been demonstrated. Dual-gap relay type tunable capacitors have been fabricated that show a continuous and reversible tuning ratio of 12 together with a quality factor larger than 150 at frequencies higher than 0.5 GHz. These are the highest tuning ratio and quality factor reported to date. A 0-level packaging concept that is compatible with the fabrication technology has been adopted.