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Marconi Microtechnology Stamps (first-day cover)

Technical Information

Catalogue No: C1394
Category: General Purpose
Object Type: Stationery/Office Items
Object Name: Marconi Microtechnology Stamps (first-day cover)
Part No: None
Serial No: None
Manufacturer: Royal Mail
Division: Integrated Circuits [of MEDL]
Year of Manufacture: 1989
Dimensions: Width (mm): 191
Height (mm): 127
Depth (mm): 1
Weight (g): 12
Location: Small Side-Room [Mezzanine Store]

Marconi Electronic Devices
Integrated Circuit Division
Marconi Electronic Devices
Microtechnology in Space
5 Sept. 89
Cotswold Covers
Liege House, Marshfield
Chippenham, Wilts


A series of four postage stamps issued to celebrate the 150th anniversary of the founding of the Royal Microscopical Society (the RMS, based in Oxford, UK) in September 1839. More information about Cotswold Covers can be found here

Of the four stamps, one portrays a magnified image of an integrated circuit's top interconnection layer and is the link with MEDL. A card within the envelope explains in more detail:

Integrating Advanced Technologies
Satellites - Microchips - Microscopes

CMOS Silicon-on Sapphire Integrated Circuit Technology for Spacecraft Electronic Systems The growth of the satellite industry and the increasing complexity of satellite electronics depends upon the availability of high performance, high reliability integrated circuits. The natural space environment includes radiation, mainly in the form of gamma rays and cosmic rays both of which can cause failure of ordinary integrated circuits.

Marconi Electronic Devices Ltd at their factory in Lincoln have developed a CMOS Silicon-on-Sapphire integrated circuit technology which will withstand continuous exposure to gamma rays and is immune to the data corruption effects of high energy cosmic rays encountered in space. This highly specialised technology enables the monolithic circuit to be built up within an extremely thin layer of silicon, which is in turn supported on an 'insulating' Sapphire substrate. This ability to make the circuits so microscopically small results in the required immunity and the Sapphire substrate eliminates any unwanted parasitic effects which may occur that would cause the circuit to malfunction.

Quality control procedures are a key part of the microchip manufacturing process. Very precise inspection and measurement of critical layers and feature size requires an accuracy of at least 0.1 microns (or better). The scanning electronic microscope, a U.K. invention, is the only absolute method of making such measurements.

The picture on the 35p stamp shows the detail of a very small part of a MA9817 64K Silicon-on-Sapphire Static RAM using 1.5 micron technology. These CMOS-SOS products plus memory devices, microprocessors and peripherals manufactured by Marconi are currently designed into many US and European Satellite Projects. The illustration on this first day cover shows a Marconi CMOS-SOS wafer containing many hundreds of memory chips, surrounded by some of the satellites using the technology.

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