Assembly & packaging
Concept for Packaging of a Silicon based Biochip
T. Velten (a), M. Biehl (a), T. Knoll (a), W. Haberer (a)
(a) Fraunhofer Institute for Biomedical Engineering, Ensheimer Strasse 48, 66386 Sankt Ingbert, Germany
Abstract
We report on a concept for packaging of a silicon-based biochip for integration with a fluidic cartridge, thus forming a lab-on-chip (LOC). The biochip, which has dimensions of 2 mm x 2 mm, comprises a central membrane having a diameter of 200 μm, and 20 bond pads with metal tracks leading to the membrane. The packaged biochip provides a fluidic interface to the cartridge as well as electrical interfaces to the biochip electronics being located in a readout instrument. The packaging method ensures the strict separation between the wet sensing area and the electrical contacts. The challenge is that the biochip has a freely moving membrane, additionally with a delicate biological coating, and this membrane is positioned on the same side of the silicon chip as the bond pads for the electrical interconnection. For packaging, the biochip is mounted into a recess of a rigid printed circuit board (PCB). The biochip is electrically connected with the PCB using a proprietary MicroFlex interconnection (MFI) technology, thus resulting in a flat surface towards the reaction chamber of the fluid cartridge. After the realization of the electrical contacts between the sensor chip and the PCB, the entire chip is encapsulated with an epoxy layer, leaving the membrane of the biochip uncovered. To protect the membrane against the fluidic epoxy, a specially shaped silicone casting-mould is used. In a last step, the biochip with the epoxy layer is glued on the bottom side of the cartridge.
| 145 reads | Material aspects for batch integration of PZT thin films using transfer bonding technologies – Q2M development
D. Bhattacharyya (a), R. V. Wright (a), Q. Zhang (a), P.B. Kirby (a), R. Guerre (b), U. Drechsler (b), M. Despont (b),
F. Saharil (c), J.Oberhammer (c)
(a) Materials Department, Cranfield University, Bedford MK43 0AL, UK
(b) IBM Research Gmbh, Zurich Research Laboratory, Rueschlikon, Switzerland
(c) Microsystem Technology Lab, KTH – Royal Institute of Technology, Stockholm, Sweden
Abstract
Transfer bonding is a reliable cost-efficient and low-temperature CMOS compatible technique which allows batch integration of materials whose incompatibility with Si makes them unsuitable for monolithic integration. In this heterogeneous device integration method the material and process incompatibilities inherent in Si IC technology are overcome by fabricating devices on separate substrates and then transferring them onto target (e.g. CMOS) wafers. Transfer bonding has great potential for integrating RF-MEMS devices incorporating, for example, high thermal budget materials such as PZT and PST or non-ferroelectric piezoelectrics such as AlN and ZnO into microwave ICs for enhanced systems performance. This paper presents an overview of technology developments within the EU sponsored project Q2M for the realization of transfer bonded piezoelectrically actuated RF MEMS switches and other components focusing in particular on material factors relating to growth of the piezoelectric films, in this case sol-gel deposited PZT, that restricts the choice of device layers and impact on PZT properties such as microstructure, film orientation and piezoelectric coefficients. New process developments such as hard masking of PZT pattern during RIE etching and its compatibility with polymer transfer bonding are discussed.
categories
Adhesive bonding | Assembly & packaging | PZT | RF MEMS switches | sol-gel | switches | transfer bondingWafer-scale manufacturing of robust trimorph bulk SMA microactuators
N. Sandström (a), S. Braun (a), T. Grund (b), G. Stemme (a), M. Kohl (b), W. van der Wijngaart (a)
a Microsystem Technology Lab, KTH - Royal Institute of Technology, Stockholm, SWEDEN
b Institut für Mikrostrukturtechnik, Forschungszentrum Karlsruhe GmbH, Karlsruhe, GERMANY
Abstract
This paper demonstrates the concept of wafer-level fabrication and integration of robust bulk SMA microactuators based on adhesive bonding of cold-rolled SMA sheets to silicon wafers. Contact printing of an adhesive polymer ensures a selective bonding when transferring full SMA sheets to silicon structures on a patterned wafer. The induced stress of a thin dielectric film deposited on top of the SMA sheet ensures a stable and built-in reset mechanism of the actuators. The trimorph microactuators can be actuated by indirect resistive heating through a thin metal film. We report on the successful wafer-scale fabrication of actuator cantilevers and their characteristics. First test cantilevers show a cold-state deflection of 300 μm which, however, is limited by the silicon substrate. Upon heating, the cantilever shows a stroke of approx. 80 μm.
categories
actuators | Adhesive bonding | adhesive bonding | Assembly & packaging | Micro-sensors & actuators | microactuators | SMA | wafer-level integrationBatch Fabrication Methods for Polymer Based Active Microsystems using Hot Embossing and Transfer Bonding Technologies
T. Grund, M. Heckele and M. Kohl
Forschungszentrum Karlsruhe GmbH, Institute for Microstructure Technology (IMT),Postfach 3640, 76021 Karlsruhe, Germany
Abstract
A batch compatible process flow to overcome the costly piece by piece assembly of hybrid microsystems is shown. Hot embossing is used to fabricate microstructured polymer layers. Wafer scale compatible bonding tasks are carried out by ultrasonic welding and heat activated bonding with micromachined bonding foils. As demonstrator device, a shape memory alloy (SMA) actuated polymer microvalve is introduced. The valve concept, fabrication technologies and device characteristics are discussed.
categories
Assembly & packaging | batch fabrication | polymer microvalve | polymers | shape memory alloy | TiNi actuator | transfer bondingThe integration of mono-crystalline silicon micro-mirrors on CMOS for SLM applications
F. Zimmera, M. Friedrichsa, M. Lapisac, F. Niklausc, M. Muellera, T. Bakkeb, H. Schenka, H. Laknera
a Fraunhofer Institute for Photonic Microsystems (IPMS), Maria-Reiche-Str. 2, D-01109 Dresden, Germany
b SINTEF Department of Mikrosystems and Nanotechnology, Gaustadalleen 23C, Oslo, Norway
c KTH, The Royal Institute of Technology, Stockholm, Sweden
Abstract
Spatial light modulators (SLMs) based on micro-mirrors for use in DUV lithography and adaptive optics need very high mirror planarity as well as mirror stability. We will present results of new micro-mirror arrays, consisting of monocrystalline silicon, which is a material to fulfil these requirements. As all mirrors of the SLM can be separately activated by an underlying CMOS circuit, the integration of CMOS and MEMS must be achieved, which results in certain restrictions on processing temperatures and the compatibility of materials. Therefore a special low temperature bonding technology has been developed, using an adhesive polymer. This technique provides the transfer of a 300nm thin mono-crystalline silicon layer to the CMOS wafer using only 250°C. First silicon micro-mirrors have been made and characterized using pure adhesive polymer (PMGI), improvements using a mix of an inorganic material with a thin bond-polymer benzocyclobutene BCB) on top are in development. Both approaches and their results will be discussed and presented in detail.
categories
Assembly & packaging | Lithography | maskless lithography | micro-mirrors | Optical MEMS | spatial light modulator | wafer bonding
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