Search results

In the never‐ending quest for speed, designers are now turning to digital GaAs integrated circuits both to extend the bandwidth of current designs and in some cases to generate a whole new class of products never before possible. The engineer well versed in high speed ECL design techniques generally understands the problems associated with this transfer to GaAs logic. However, even with the design task well defined, the exact solution for interconnecting devices is often difficult and stresses the capabilities of existing multilayer printed circuit techniques using conventional dielectric materials and processing. This paper examines the design task in detail, and will present recent developments in shielded discrete wiring techniques as a possible solution for GaAs packaging.

The paper describes a new electro‐optical board technology, based on the discrete wiring principle. Isolated copper wires are embedded in the circuit board to realise the electrical interconnections. Glass optical fibres are embedded to obtain optical interconnections. The technology allows for crossovers and for electrical and optical interconnections on one layer of interconnection. As the technology can be applied on the level of package or multichip module, circuit board and backpanel, it has the ability to offer a complete solution for chip to chip electrical and optical interconnections. The paper will describe the basic manufacturing technology of the boards. The benefits of the technology from a system designer's viewpoint will be addressed. The problem of coupling light in and out of the embedded optical fibres will be discussed and the realisation of a first on‐board optical link via embedded optical fibres will be described.

The evolution of today's high speed electronic systems has resulted in the need for modules which are able to provide all chip‐to‐chip interconnection with very fine top level and buried conductor traces, and a dielectric with a very dense via grid pattern. As standard thick film technology is capable of pitches only down to 250 µm, new photoimageable thick film pastes have been developed in order to achieve a higher resolution. These materials allow one to combine the advantages of screen printing as a deposition technique with photolithography for the patterning. The image is produced by exposing the printed paste through a photomask to define either lines or vias, so that a very high resolution (50 (µm pitch), similar to that available in MCM‐D or MCM‐L, can be achieved. This paper describes the processing of the photoimageable dielectric and conductor pastes. As an example of the capability of this technology, a module for electro‐optical interconnection is presented.

The Second Brazilian Printed Circuit Association Seminar will take place in Rio de Janeiro from 21–23 September 1988. Papers will be presented on the following topics:

On 8 October 1992 the ISHM‐Benelux Chapter organised a one‐day conference entitled ‘New Trends in Electronic Packaging and Interconnection’ which took place in the Holiday Inn, Gent, Belgium. This conference was attended by 45 participants from the Benelux countries and Great Britain.

A new model for the power system, covering resistance, self‐inductance, mutual inductance, and capacitive coupling between planes is presented. The model parameters are calculated from the geometry of the actual board. No measurements are necessary to set up a model for a new board. The model has been verified against detailed computer simulations and measured data.