Vacuum news

Electron beam vacuum evaporation equipment

G V PLANER LTD (Windmill Road, Sunbury-on-Thames, Middlesex, England) Electron beam vacuum evaporating equip- ment. The combined electron beam con- version kit will fit most sizes of existing vacuum evaporators. The water-cooled electron beam source may be focussed during use in the vacuum chamber and a spot size of less than I mm is easily main- tained. Other configurations of multi- crucible electron beam sources are available and these can be supplied with the necessary accessories, operating linkages, etc, as a complete kit ready for use. An alternative kit is available provided with a source designed for vertical mounting in the base plate of the evaporator. The necessary electrodes and focusing mechanism control are also supplied.

Economy model electron beam evaporator. The concept underlying this new model is an endeavour to make available at an economic price the electron beam method of evaporation for education and study purposes. The equipment comprises a simple electron beam source with appro- priate power supply unit: the evaporating source type EB3 consists of an annular electron emitter and an evaporant holder with cermet crucible of dimensions approxi- mately 1.8 cm diameter by 1.5 cm height, mounted on a column together with a substrate holder bracket. The power unit type $7/I E provides a continuously variable HT supply of up to 7 kV, de, rated at 200 mA, with an LT supply, variable up to 6 V/16 A insulated to 7 kV to heat the emitter filament. Suitable surge and over- load protection is incorporated. The entire unit is housed in a floor-standing metal cabinet of 43 inches height×23 inches width × 27 inches depth approximately, and is generally of similar appearance to the standard model type $7/1. The unit is fully interlocked. Operation is from 230 V, 50 c/s mains, but other voltages may be supplied.

Eyelet thermocompression bonder. Apart from the normal metal combinations suit- able for thermocompression bonding, eg gold-to-gold and aluminium-to-gold, the eyelet bonder allows reliable bond forma- tion between aluminium leads and alumin- ium pads in transistors or Kovar terminal posts of transistor headers. The equipment features a specially shaped bonding tool

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El'clef Thermocompre,sxh~#t hoHder

which induces lateral flow of metal during bond formation. This, in conjunction with the precision, non-arcuate movement of the tool, results in the formation of high reliability bonds and the disintegration of surface oxidation. The machine provides facilities for instantaneous tensile testing under controlled conditions after each bond is formed, by use of a torque motor which applies a predetermined test pull on the wire. To eliminate shimmer effects due to convection of the heated gas enveloping the work piece, when viewing the operation through the microscope, a jet of cool gas is directed over the work piece to form a barrier. The wire feed magazine is in the form of a detachable plug-in unit, allowing wire loading remote from the machine to save operating time. Both the wire feed magazine and work column positions are adjustable by micromanipulators. The eyelet Bonder was designed by the General Post Office in conjunction with GV Planer Ltd, and is manufactured and marketed under licence from the General Post Office. Several of the features described are the subject of patent applications.

Surface profile monitor. This is a stylus type instrument designed for the contour display of surfaces and is suitable for measuring thicknesses of thin films within

EB3 type evaporation sonrce

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Sm~face Profih, ,~f<mitor

the range 0 50,000 A. A displacement transducer nlonitors movement of a diamond stylus with reference to a datum skid, both of which arc made to traverse the surface to be evaluated, two alternative speeds of motorised advance being pro- vided. The surface variations are con- tmuously indicated by pointer displacement, and at the same time the surface profile is recorded to an accuracy of better than 50 .& on the 50 mm strip chart recorder incor- porated in the control unit. An output jack is also provided to enable an additional larger recorder to be used externally, if higher chart magnification is desired. The stylus with a tip radius of 0.0008 inch is mounted 0.093 inch in advance of a l-inch long tungsten carbide reference skid. A vacuum chuck is provided in the work table to secure the specimen during evaluation.

Vacuum controller with vacuum control head. This new equipment provides a means for controlling vacuum coating systems over the range of from 1 torr to 5 • [0 :' torr and 3 . 10 :~ tor r to 5 . 10 " torr. The operat ion relies on the moni to r ing of output currents f rom the Pirani and Penning gauges in the vacuum system which are displayed on meters wi th two adjustable control l imits for each range. The latter provide threshold facilities, eg for the operation of regulating needle or baffle valves in the vacuum plant. The system can also be used to provide switching from the rotary to the diffusion pump or to initiate a vacuum coating cycle at pre-set pressures. The equipnient is particularly applicable to vacuum evaporation and sputtering processes in connection with the produc- tion of thin film electronic components and the like where close control of vacuum conditions is required.

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