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Uhlig, Steffen
Publications (8 of 8) Show all publications
Uhlig, S. & Robertsson, M. (2006). Limitations to and solutions for optical loss in optical backplanes. Journal of Lightwave Technology, 24(4), 1710-1724.
Open this publication in new window or tab >>Limitations to and solutions for optical loss in optical backplanes
2006 (English)In: Journal of Lightwave Technology, ISSN 0733-8724, E-ISSN 1558-2213, Vol. 24, no 4, 1710-1724 p.Article, review/survey (Refereed) Published
Abstract [en]

In this paper, recent literature on the discussion on high-speed backplanes with optical, electrical, and mixed solutions, as well as on polymer-waveguide systems suitable for implementation on printed circuit boards (PCBs), is reviewed from the point of view of their optical losses. The reevaluation of the optical power budget for realistic high-speed optical polymer-waveguide links on backplanes showed that signal amplification is necessary to boost the signal, which resulted in an additional literature review on advances in optical amplifiers based on silicon bench technology available. Finally, a concept study of an active optical waveguide amplifier device, based on planar optical waveguide amplifiers and semiconductor optical amplifiers, was performed. The amplification device can be flip-chip mounted on the backplane to compensate for optical losses due to signal routing, which increases the overall degree of freedom in waveguide routing on high-density interconnects for backplanes. The hybrid concept design guarantees compatibility with the processes of the PCB industry. © 2006 IEEE.

Keyword
Optical backplane, Optical interconnects, Optical power budget, Planar optical waveguide amplifier, Semiconductor optical amplifier
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-50243 (URN)10.1109/JLT.2006.870978 (DOI)
Available from: 2009-10-11 Created: 2009-10-11 Last updated: 2017-12-12
Uhlig, S. (2006). ORMOCER Materials Characterization, LAP- & Micro-Processing: Applied to Optical Interconnects and High-Frequency Packaging. (Doctoral dissertation). : Institutionen för teknik och naturvetenskap.
Open this publication in new window or tab >>ORMOCER Materials Characterization, LAP- & Micro-Processing: Applied to Optical Interconnects and High-Frequency Packaging
2006 (English)Doctoral thesis, monograph (Other academic)
Abstract [en]

ORMOCERR®s are organic-inorganic hybrid polymers. Since their material properties can be tailored precisely during synthesis, they are suitable for a wide range of applications in dielectric and optical microelectronics. This thesis reports on process development of ORMOCERR®s for Sequentially Build-Up (SBU) test vehicles, suitable for both electrical and optical interconnect. Furthermore, this work includes materials characterization, such as refractive index studies (system B59:V32), optical loss measurements (systems B59:V32 and B59:B66), and surface characterization through contact angle measurement and surface energy estimation (systems B59:V32 and B59:B66).

Process development for a high-frequency test vehicle was performed applying a newly developed dielectric material of the ORMOCER® class. Dielectric layers in a total thickness of 80 μm were build-up on a common FR4 substrate, applying photolithographic processes and moderate process temperatures of below 433 K. The loss tangent and the permittivity of the material were measured to be 0.024 (loss tangent) and 3.05 (permittivity) over the entire frequency range 10 GHz to 40 GHz. The compatibility of the material to standard processes of the PCB industry was proven. Furthermore, a possibility for cost reduction in high-frequency MCM applications was shown, through the possibility of using low-cost substrates.

The concept of a “flexible manufacture approach” for large-area panel optical backplane interconnects was introduced. Here, a 101.6 mm x 101.6 mm photolithographic mask is to be stepped-out over a large-area panel substrate (up to 609.6 mm x 609.6 mm). The goal is to be able to create a large amount of continuous and unique waveguide patterns over the whole area with a small portfolio of masks, thus being able to minimize excess costs. In practice continuous waveguide patterns were created over an area of 204.8 mm x 204.8 mm on a large-are panel (609.6 mm x 609.6 mm), using a large-are mask aligner and a 101.6 mm x 101.6 mm waveguide mask. The optical loss of the waveguides was measured to be 0.6 dB/cm (B59:V32 material system, λ =850 nm).

In connection to the large-area panel project a re-evaluation on the optical power budget needed for high bit rate optical interconnects was performed. This work was mainly based on literature surveys of optical waveguide materials, planar optical amplifiers, light coupling structures, and planar light-routing structures. It was shown that optical amplification is necessary at certain places on realistically routed optical backplanes to boost the optical signal. Therefore, the concept of a flip-chip mountable optical amplifier (FOWA) device, based on planar optical waveguide amplifiers and Semiconductor Optical Amplifiers, was developed. The device’s design allows an independent manufacturing to the rest of the board and a mounting at key-positions using standard pick and place technology. Additionally, it was observed that most of the amplifier research is focused on the wavelength of 1310 nm and 1550 nm, whereas optical backplane applications are targeting the 830 nm range.

During SBU processing of waveguide structures was discovered a de-wetting phenomenon of B59 resin on a cured B59:B66 and B59:V32 surface, respectively. Good wetting behavior could be achieved by adding small amounts of B66 or V32, respectively, to the B59. Surface tension estimations on various compositions of the systems B59:B66 and B59:V32 could not directly be correlated to the de-wetting phenomenon. Furthermore, the optical loss properties of B59 were only affected to a minor degree by adding B66 or V32. The process route proposed is an efficient alternative to processes including surface activations steps, thus opening possibilities for large-area processing in PCB industry, where surface activation steps, such as plasma activation or silanization, are not available.

The process development, materials characterization, and reviews presented provide a basis for further research on processes for high-performance electro/optical backplane interconnects with focus on Large-Area Panel processing.

Place, publisher, year, edition, pages
Institutionen för teknik och naturvetenskap, 2006. 145 p.
Series
Linköping Studies in Science and Technology. Dissertations, ISSN 0345-7524 ; 1011
Series
Keyword
Optical interconnects, Optical Backplanes, ORMOCER, SBU-technology, high-frequency packaging, surface characterization
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:liu:diva-6380 (URN)91-85523-99-2 (ISBN)
Public defence
2006-04-24, K3, Kåkenhus, Campus Norrköping, Linköpings universitet, Norrköping, 10:00 (English)
Opponent
Supervisors
Available from: 2006-05-05 Created: 2006-05-05 Last updated: 2009-06-05
Uhlig, S., Frohlich, L., Chen, M., Arndt-Staufenbiel, N., Lang, G., Schroder, H., . . . Robertsson, M. (2006). Polymer optical interconnects - A scalable large-area panel processing approach. IEEE Transactions on Advanced Packaging, 29(1), 158-170.
Open this publication in new window or tab >>Polymer optical interconnects - A scalable large-area panel processing approach
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2006 (English)In: IEEE Transactions on Advanced Packaging, ISSN 1521-3323, E-ISSN 1557-9980, Vol. 29, no 1, 158-170 p.Article in journal (Refereed) Published
Abstract [en]

A flexible approach to producing optical interconnects on 609.6 * 609.6 mm large-area panels is demonstrated. Stepwise projection patterning from 101.6 * 101.6 mm masks has generated optical waveguide patterns over the whole panel using large-area projection lithography equipment. The waveguide routing design allows optical waveguides on different 101.6 * 101.6 mm tiles to be interconnected. Four different waveguide connecting geometries in the border region between tiles have been fabricated and tested. Multimode waveguides from inorganic-organic hybrid polymers (ORMOCER) (cross section: = 50 µm * 10 µm) with refractive index step between core and cladding ?n = 0.01 were produced. The index step was adjusted by mixing two diffrent ORMOCER systems. The materials show good adhesion to numerous substrates, such as glass and silicon. Application concepts such as flexible manufacturing of optoelectrical hybrid backplanes with two-dimensional interconnect, a three-dimensional optical interconnect with optical vias, and a hybrid backplane with the optical interconnect in a strip-format on a separate plane right above the electrical plane are proposed. Promising new technologies are presented along with preliminary demonstrativ viability. © 2006 IEEE.

Keyword
Flexible manufacturing approach, Hybrid polymers, Large-area processing, Optical backplane, Optical interconnect review, ORMOCER, Polymer optical waveguide, Projection UV lithogaphy
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-50305 (URN)10.1109/TADVP.2005.849555 (DOI)
Available from: 2009-10-11 Created: 2009-10-11 Last updated: 2017-12-12
Uhlig, S., Domann, G., Houbertz, R., Frohlich, L., Schroder, H., Krissler, J., . . . Robertsson, M. (2006). Preventing of dewetting effects for inorganic-organic hybrid polymers applied in sequentially buildup (SBU) technology without surface pretreatments. IEEE transactions on electronics packaging manufacturing (Print), 29(4), 297-307.
Open this publication in new window or tab >>Preventing of dewetting effects for inorganic-organic hybrid polymers applied in sequentially buildup (SBU) technology without surface pretreatments
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2006 (English)In: IEEE transactions on electronics packaging manufacturing (Print), ISSN 1521-334X, E-ISSN 1558-0822, Vol. 29, no 4, 297-307 p.Article in journal (Refereed) Published
Abstract [en]

Upon processing waveguide structures by using the ORMOCER materials ORMOCORE as core material, and a mixture of ORMOCORE and ORMOCER-III (refractive index tuning agent) as cladding material, dewetting effects of the core layer from the cladding layer were observed. A similar phenomenon was observed for a mixture of ORMOCORE and ORMOCLAD which was used as comparative refractive index tuning material. In order to use these material combinations for large-area panel (LAP) processing, a pretreatment or activation of surfaces is necessary but hard to realize. However, the addition of small amounts of ORMOCER-III or ORMOCLAD, respectively, to the core layer material, prevented the dewetting phenomenon. The objective of this, however, is to minimize the content of refractive index tuning agent in the core layer by retaining a good wetting behavior during multilayer processing. Wet film stability tests and contact angle measurements of these ORMOCER systems in various compositions on another ORMOCER surface of a specific cladding material composition were performed on a hotplate. Furthermore, contact angles of droplets formed by deionized water, formamide, and di-iodomethane on cured surfaces of these ORMOCER systems in a wide range of compositions were characterized, and surface tensions were calculated. By adding 0.1 wt% of ORMOCER-III or 5 wt% ORMOCLAD, respectively, to the pure ORMOCORE solution, the dewetting phenomenon was eliminated, while simultaneously the refractive index was affected only to a minor degree and no changes in the optical loss could be detected. It was shown that by adding ORMOCER-III or ORMOCLAD to pure ORMOCORE, the surface tension of the compound system was reduced. In comparison to silanization or gasplasma treatment to overcome dewetting effects in microelectronics multilayer processing, the investigated mixing method eliminates process steps and thus costs, and opens new process routes for LAP processing. © 2006 IEEE.

Keyword
Alternative process route, Contact angle measurement, Dewetting, Heterogeneous multilayer structure, Large-area panel processing, ORMOCER, Sequentially buildup unit (SBU), Surface tension
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-50123 (URN)10.1109/TEPM.2006.887399 (DOI)
Available from: 2009-10-11 Created: 2009-10-11 Last updated: 2017-12-12
Uhlig, S. & Robertsson, M. (2005). Flip chip mountable optical waveguide amplifier for optical backplane systems. In: Electronic Components and Technology Conference ECTC,2005 (pp. 1880). conference proceedings: IEEE.
Open this publication in new window or tab >>Flip chip mountable optical waveguide amplifier for optical backplane systems
2005 (English)In: Electronic Components and Technology Conference ECTC,2005, conference proceedings: IEEE , 2005, 1880- p.Conference paper, Published paper (Refereed)
Place, publisher, year, edition, pages
conference proceedings: IEEE, 2005
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-32322 (URN)18214 (Local ID)18214 (Archive number)18214 (OAI)
Available from: 2009-10-09 Created: 2009-10-09
Uhlig, S., Robertsson, M., Schröder, H., Lang, G., Arndt-Staufenbiel, N., Popall, M., . . . Houbertz, R. (2004). Large-area processing of inorganic-organic hybrid polymers (ORMOCER-Reg Trademark) for optical backplane application. In: International Convention on Glass 2004,2004. .
Open this publication in new window or tab >>Large-area processing of inorganic-organic hybrid polymers (ORMOCER-Reg Trademark) for optical backplane application
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2004 (English)In: International Convention on Glass 2004,2004, 2004Conference paper, Published paper (Other academic)
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-22731 (URN)2036 (Local ID)2036 (Archive number)2036 (OAI)
Available from: 2009-10-07 Created: 2009-10-07
Johansson, C., Uhlig, S., Tageman, O., Alping, A., Haglund, J., Robertsson, M., . . . Fröhlich, L. (2003). Microwave circuits in multilayer inorganic-organic polymer thin film technology on laminate substrates. IEEE Transactions on Advanced Packaging, 26(1), 81-89.
Open this publication in new window or tab >>Microwave circuits in multilayer inorganic-organic polymer thin film technology on laminate substrates
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2003 (English)In: IEEE Transactions on Advanced Packaging, ISSN 1521-3323, E-ISSN 1557-9980, Vol. 26, no 1, 81-89 p.Article in journal (Refereed) Published
Abstract [en]

Requirements of higher performance, reduced size, weight and cost of high-frequency (HF) devices has led to the search for new: materials, material combinations, methods, processes and production equipment. Efficient technologies for producing HF-circuits and integral passives are looked for. Also of interest are integrated packaging solutions for high frequency electrical packaging and optical interconnects and packaging. Sequentially build up multi-layers have been deposited on a low cost FR-4 epoxy substrate. The dielectric layers consist of a photo-patternable inorganic-organic hybrid polymer (ORMOCER) and the metallization is Cu. An UV-exposure equipment enabling projection patterning with 5 μm resolution have been used. The produced microstrip lines, ring resonators, vias, stacked capacitors and filters have been characterized at frequencies from 1 to 40 GHz showing the potential of the new dielectric materials and processing technologies for microwave applications.

Keyword
High frequency electrical characterization, microwave circuits, multilayer thin film technology, ORMOCER
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-13134 (URN)10.1109/TADVP.2003.811548 (DOI)
Available from: 2008-04-03 Created: 2008-04-03 Last updated: 2017-12-13
Johansson, C., Uhlig, S., Tageman, O., Alping, A., Haglund, J., Robertsson, M. & Popall, M. (2002). Microwave circuits in multilayer ORMOCER® thin film. In: Proceedings IMAPS Nordic 2002. Paper presented at IMAPS Nordic 2002 Conference, Globe Hotel, Stockholm, Sweden, 29 September - 2 October 2002 (pp. 60-63). .
Open this publication in new window or tab >>Microwave circuits in multilayer ORMOCER® thin film
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2002 (English)In: Proceedings IMAPS Nordic 2002, 2002, 60-63 p.Conference paper, Published paper (Other academic)
Abstract [en]

A multilayer sequential build-up structure for the integration of passivemicrowave devices is presented. The different devices were processed byusing a photo-patternable polymer ORMOCER together with conducting layersof Cu on top of a FR-4 substrate. Microstrip and stub structures have beencharacterised at frequencies between 1 to 40 GHZ showing the feasibility ofusing this kind of material and build-up technology for microwaveapplications.

National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-13133 (URN)
Conference
IMAPS Nordic 2002 Conference, Globe Hotel, Stockholm, Sweden, 29 September - 2 October 2002
Available from: 2008-04-03 Created: 2008-04-03 Last updated: 2012-11-22
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