Coating processes – Electrical product produced – Integrated circuit – printed circuit – or circuit board
Patent
1986-02-12
1988-05-10
Morgenstern, Norman
Coating processes
Electrical product produced
Integrated circuit, printed circuit, or circuit board
118 70, 118302, 118410, 118411, B05D 512
Patent
active
047434651
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
The present invention relates to a method and apparatus for drawing a thick film circuit wherein a thick film circuit including resistors, capacitors and electric conductors is drawn on a substrate by discharging a paste from a tank with a discharge hole.
BACKGROUND OF THE INVENTION
A thick film circuit is being adapted for use in many types of electronic equipment such as broadcasting radio receivers, television receivers, video tape recorders, communication equipment, and measuring equipment.
A thick film circuit is generally formed using the screen printing method. More specifically, a desired pattern is formed on a substrate made of alumina ceramic using a conductor paste, resistor paste or the like, followed by drying and heating so as to manufacture a thick film circuit. However, the screen printing method uses a mask pattern, with the results that longer time is required for the exchange of the mask pattern, and cleaning of the mask pattern and squeegee, and thus it is unsuitable for small lot production and frequent changes of pattern.
On the other hand, a method, which involves drawing on a moving substrate using a paste directly extruded from a nozzle without employing the mask pattern, is reported by "1978 International Microelectronics Symposium of ISHM, Minneapolis, MN, Sept. 17, 1978" and is introduced by a journal "Electronic Packaging and Production (January, 1981), Pages 98-109".
In operation, a drawing nozzle having a discharge hole for discharging a paste is kept at a certain distance from a substrate and is relatively moved with respect to the substrate to apply the paste withdrawn on a predetermined pattern of a thick film circuit. This drawing method does not require the mast pattern because the thick film circuit is drawn by means of NC control, thereby allowing quick changes in the kind of pattern to instantly modify the circuit.
However, one problem with such a drawing method is that the viscosity of the paste is partially increased due to evaporation of solvent from the paste at the discharge hole during long non-drawing times, that is, the paste is dried, and the increase of the viscosity causes the occurrence of clogging. Therefore, it is required to frequently clean the discharge hole and thus difficulty is encountered to increase workability and productivity.
DISCLOSURE OF THE INVENTION
A primary object of the present invention is therefore to provide a drawing method and apparatus which are capable of preventing a paste from clogging at the discharge hole of a tank.
Another object of the present invention is to provide drawing method and apparatus which are capable of significantly increasing workability and productivity.
These objects of the present invention are achieved by extruding a paste from a tank after a predetermined interval of non-drawing duration for performing waste-drawing on a waste drawing portion.
In a method for drawing a thick film circuit on a substrate by extruding a paste from a tank with a discharge hole according to the present invention, a tape for waste drawing is provided at a place other than the substrate and the paste is discharged from the tank after a predetermined interval of non-drawing duration for performing waste-drawing on the tape, and after the completion of the waste-drawing, the tape is reeled around a reel by a predetermined amount.
Furthermore, an apparatus according to the present invention comprises a tank having a paste therein and a discharge hole, an X-axis drive section and a Y-axis drive section for supporting the tank and for moving the same in a predetermined plane, an up-and-down drive section for moving upwardly and downwardly the tank supported by the X-axis and Y-axis drive sections, and a control section for controlling the discharge of the paste from the discharge hole, the X-axis and Y-axis drive sections and the up-and-down drive section, and is arranged so as to extrude the paste from the tank at a predetermined interval of non-drawing duration under the control of the control section to per
REFERENCES:
patent: 4515297 (1985-05-01), Schoenthaler
patent: 4572103 (1986-02-01), Engel
patent: 4603655 (1986-08-01), Switall
Morris Shankin, "WRITE IT, DON'T SCREEN IT!", from 1978 International Microelectronics Symposium of ISHM, Minneapolis, MN, Sep. 17, 1978.
Morris Shankin, "HYBRID CIRCUITS BY COMPUTERIZED WRITING", from Electronic Packaging and Production, Jan. 1981, pp. 98-109.
Kudo Shin-ichi
Nakatsuji Hachiro
Saeki Keiji
Dang V. Duong
Matsushita Electric - Industrial Co., Ltd.
Morgenstern Norman
LandOfFree
Method and apparatus for drawing thick film circuit does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and apparatus for drawing thick film circuit, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and apparatus for drawing thick film circuit will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1319897