Patent GB-1011173-A (GB)
Title: Improvements in and relating to the making and testing of thin film articles
IPC: H01J37/30
Filed: 1963-09-03
Abstract: <PICT:1011173/C4-C5/1> <PICT:1011173/C4-C5/2> In a method of testing a thin film article, a light-emissive substrate carrying said article is bombarded with a non-destructive beam of charged particles to cause the substrate to emit light, and the thus illuminated article is examined for variations in opacity indicative of flaws therein. As shown, electrons from cathode 16, Fig. 1, are accelerated by anode 18 and focused into a beam by magnetic lenses 24, 26, 29 and diaphragms 28, 30, the beam current being controlled by grid cup 20. An optical viewing system includes light 38, mirrors 40, 42 and lens 50, the viewer being protected by a leaded glass window 52.  Two substrates to be coated are secured by supports 68, 70 to a part-cylindrical member 60 which is rotatable by geas 62, 63. Initially the substrates are positioned as shown in Fig. 2, and a crucible 76, movable along track 74, is aligned with the electron beam, material therein being evaporated and condensing as an even film on the substrates.  Photo-electric devices monitoring light through a transparent surface which is also exposed to the vapour may be used to automatically cut off the beam when the desired coating thickness is reached. The crucible and substrates are then moved to the position shown in Fig. 1, and the beam focus is adjusted for scribing, by local evaporation, discrete lines or patterns in the substrate coating to form thin film resistors, inductors or capacitors, the beam being moved for this purpose by deflecting coils 34.  The beam may also be used to weld leads to contact pads provided on the thin film device.  Finally, the coated substrate is irradiated with a moving reduced-intensity, defocused electron beam which causes suitable substrates, e.g. of aluminium, to fluoresce, and thereby reveals flaws or discontinuities in the coating film and scribed pattern as variations in the opacity of the film even when it is covered by protective SiO.  This irradiation also yields information as to the surface condition of the substrate, as the colour of the fluorescence varies with the electron bombardment to which the alumina has been previously subjected.ALSO:<PICT:1011173/C6-C7/1> <PICT:1011173/C6-C7/2> In a method of testing a thin film article, a light-emissive substrate carrying said article is bombarded with a non-destructive beam of charged particles to cause the substrate to emit light, and the thus illuminated article is examined for variations in opacity indicative of flaws therein.  As shown, electrons from cathode 16, Fig. 1, are accelerated by anode 18 and focused into a beam by magnetic lenses 24, 26, 29 and diaphragms 28, 30, the beam current being controlled by grid cup 20. An optical viewing system includes light 38, mirrors 40, 42 and lens 50, the viewer being protected by a leaded glass window 52.  Two substrates to be coated are secured by supports 68, 70 to a part-cylindrical member 60 which is rotatable by gears 62, 63. Initially the substrates are positioned as shown in Fig. 2, and a crucible 76, movable along track 74, is aligned with the electron beam, material therein being evaporated and condensing as an even film on the substrates.  Photoelectric devices monitoring light through a transparent surface which is also exposed to the vapour may be used to automatically cut off the beam when the desired coating thickness is reached.  The crucible and substrates are then moved to the position shown in Fig. 1, and the beam focus is adjusted for scribing, by local evaporation, discrete lines or patterns in the substrate coating to form thin film resistors, inductors or capacitors, the beam being moved for this purpose by deflecting coils 34.  The beam may also be used to weld leads to contact pads provided on the thin film device.  Finally, the coated substrate is irradiated with a moving reduced-intensity, defocused electron beam which causes suitable substrates, e.g. of aluminium, to fluoresce, and thereby reveals flaws or discontinuities in the coating film and scribed pattern as variations in the opacity of the film even when it is covered by protective SiO.  This irradiation also yields information as to the surface condition of the substrate, as the colour of the fluorescence varies with the electron bombardment to which the alumina has been previously subjected.