Radiation imagery chemistry: process – composition – or product th – Imaging affecting physical property of radiation sensitive... – Making electrical device
Patent
1983-06-02
1986-06-24
Kittle, John E.
Radiation imagery chemistry: process, composition, or product th
Imaging affecting physical property of radiation sensitive...
Making electrical device
430313, 430314, 430315, 430316, 430318, 430394, 430319, G03C 500
Patent
active
045967628
DESCRIPTION:
BRIEF SUMMARY
The invention relates generally to an electronic thin-film circuit having an insulating substrate with a resistance film and a conductive metal film deposited thereon.
BACKGROUND
An electronic thin-film circuit of this type is already known from German Patent Disclosure Document DE-OS No. 29 06 813. In thin-film circuits of this kind, the soft-solder film is capable of increasing the conductivity of the tracks to a sufficient extent only if the tracks are relatively wide. With finely structured tracks, however, the specific resistance of the soft solder does not suffice for this purpose. There are also difficulties associated with applying the soft solder. Furthermore, the soft-solder film in the vicinity of the connection contacts is suitable only for applying hybrid units which are supposed to be incorporated into the circuit by the reflow soldering process. Semiconductor elements not provided with a housing, however, cannot be introduced into the circuit with the aid of the soft-solder film. Semiconductor elements of this kind and their bonding wires also cannot be applied without difficulty to the locations not coated with soft solder, where the metal film which is solderable and capable of being reinforced by electroplating has been laid bare.
THE INVENTION
Briefly, the thin-film circuit of the present invention reinforces the connection tracks by depositing gold thereon and has the advantage over the prior art that with finely structured tracks, the track conductivity is increased to a sufficient extent by means of the gold film that is applied, and that furthermore the opportunity is afforded of accommodating in the hybrid circuit even semiconductor elements which have not been provided with a housing. These elements are then applied by means of conductive glue to the connection areas coated with gold. The electrical contact between the internal semiconductor metal layer and the external hybrid circuit metal layer, the latter reinforced with gold, is then established with the aid of the bonding technique.
DRAWING
One exemplary embodiment of the electronic thin-film circuit according to the invention is shown in the drawing and explained in detail in the following description. Shown are:
FIG. 1, a detail of an electronic thin-film circuit according to the invention, seen in a plan view;
FIG. 2, a section taken along the line A-A' of FIG. 1;
FIGS. 3a-3d, the electronic thin-film circuit of FIGS. 1 and 2 in the course of being fabricated, showing the various method steps to be performed in accordance with the invention;
FIG. 4, a sectional illustration explaining the effect of the application of an additional thin layer of photosensitive resist after the gold film has been applied.
DESCRIPTION OF THE EXEMPLARY EMBODIMENT
In the electronic thin-film circuit shown in FIGS. 1 and 2, a resistance film 2, which may be of tantalum oxynitride, is applied to a substrate plate 1 of insulating material. The resistance film 2 partially covers the substrate plate 1, forming a first pattern M.sub.1 and a second pattern M.sub.2. The first pattern M.sub.1 defines tracks and/or connection contacts, while the second pattern M.sub.2 defines circuit elements of the electronic thin-film circuit. In the vicinity of the first pattern M.sub.1, a metal film 3 which is solderable and can be reinforced by electroplating is disposed above the resistance film 2; this metal film 3 may be of nickel, and an intermediate film acting as a diffusion block may be disposed if needed between the resistance film 2 and the metal film 3 which is solderable and capable of being reinforced by electroplating. An intermediate film of this type may be embodied and fabricated in the manner described in German Patent Disclosure Document DE-OS No. 29 06 813, for example. A soft-solder film 8 is applied to parts of the metal film 3 which is solderable and can be reinforced by electroplating, inside the first pattern M.sub.1, in order to form tracks and/or connection contacts which are reinforced with soft solder. On other parts of the met
REFERENCES:
patent: 3287191 (1966-11-01), Borth
patent: 3423205 (1969-01-01), Skaggs et al.
patent: 3634159 (1972-01-01), Croskery
patent: 3649392 (1972-03-01), Schneck
patent: 3700445 (1972-10-01), Croson
patent: 3751248 (1973-08-01), Goell
patent: 4075416 (1978-02-01), Kuttner et al.
patent: 4424409 (1984-01-01), Kuttner
Dees Jos,e G.
Kittle John E.
Robert & Bosch GmbH
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