JPH03138910A - Manufacture of resistor - Google Patents

Abstract

PURPOSE:To enable baking with high-speed and compact facilities by coating a metallic substrate surfaced with an insulation layer with an electrode paint and a resistor paint and then by baking the work by high-frequency induction heating. CONSTITUTION:An aluminum metallic plate 3 surfaced with an insulation layer 4 made of an epoxy resin insulation paint is baked in the insulation layer 4 at a temp. increase rate of 60 deg.C/sec by use of an induction heater. Further, an electrode pattern is printed on both ends of a carbon paint 6 pattern from an epoxy resin-silver paint 5 and baked at the same condition. Heating by high-frequency induction applies high energy directly to the metal of a resistor substrate 3 and can, therefore, make extremely high-speed temp. increases, thereby heating the paints 5, 6 efficiently. As a result, the hardening time can be shortened in addition of temp increase as compared with external heating. This allows baking with facilities compact in both glace and equipment.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method for manufacturing fixed resistors, variable resistors, sensor resistors, or heater resistors used in various electronic devices.

Conventional technical resistors can be roughly classified into two types depending on the electrode paint and/or resistance paint used. That is, it is a conductive powder/resin dispersion paint or a conductive powder/glass frit dispersion paint. Conventionally, the former is around 200℃, and the latter is 8℃.
Resistors are manufactured by external heating and firing in a hot air drying oven or infrared oven at around 00°C.

Problems to be Solved by the Invention The time required for firing is 10 minutes for conductive powder/resin dispersion paint.
A firing time of 45 minutes to 60 minutes is required for conductive powder/glass frit dispersed paints, and heavy and long firing equipment is essential for mass production.

The present invention solves these conventional problems,
The purpose is to enable extremely high-speed firing on the order of seconds, and to perform firing using high-speed and compact equipment.

Means for Solving the Problems In order to achieve the above object, the present invention uses a metal substrate having an insulating layer on the surface as a substrate for a resistor, and after applying an electrode paint and/or a resistance paint, a high frequency induction The metal part of the resistor substrate is heated by heating, and each of the above-mentioned paints is baked with the heat.

Function As described above, heating by high-frequency induction directly applies high energy to the metal of the resistor substrate, so extremely high-speed heating is possible, and the coating film is efficiently heated from inside the substrate through the insulating layer on the surface. Therefore, it is possible to bake at a higher temperature than in the case of external heating, and in addition to shortening the temperature raising time, the curing time can also be shortened.

Example (Example 1) Phenol/xylene resin based carbon paint on the surface
A predetermined pattern (2 x 22 mm) was screen printed on an aluminum metal plate (6 x 35 m) with a total thickness of 0.48 m on which an insulating layer was formed with a μm epoxy resin insulating paint. ℃ heating method for 15 minutes, and
KH7.5KW: (manufactured by 1 Seidensha) was used, the surface temperature of the insulating layer was set to x°C, the temperature was raised at a rate of 60°C/sec, and the total firing time was y seconds. Note that X is 250°280.320 and y is 10.20.30. The induction heating machine uses a heating method that adjusts the induction power after raising the temperature so that it can be maintained at each set temperature. Furthermore, electrode patterns are printed with epoxy resin and silver paint on both ends of the pattern of carbon paint, and each of the above Each resistor was fired under the same conditions as a60℃90~95%R,H
10 each in a humid atmosphere of 70°C and a heat-resistant atmosphere of 70°C.
Table 1 shows the measurement results of the rate of change in resistance value after being left for 00 hours.

(Margins below) From the results in Table 1, it can be seen that the conventional infrared ray/hot air furnace 200°C1 was heated under the heating curing conditions of 250 to 280°C for 10 to 20 seconds.
It was confirmed that performance equivalent to or better than that obtained by heat curing for 5 minutes was obtained.

(Example 2) Metal core ceramics substrate (6X35+am) (0,
4M iron base, insulating layer 100μm: manufactured by Fujikura Electric Wire) with silver
Screen print the electrode pattern using palladium/glass frit paint (C-4610 manufactured by Sumitomo Metal Mining Co., Ltd.), and
As a comparative example, there is a method of firing at 850°C for a total time of 45 minutes in an infrared furnace, and a method of firing at 850°C for a total time of 45 minutes as an example.
Hz, 10kW: (manufactured by m Seidensha), the surface temperature was set to 8
A ruthenium oxide/glass frit-based resistor was set to 50°C, heated at a heating rate of 80°C/sec, fired for a total firing time of 50 seconds, and connected to the electrode under the same conditions as above. Paint (Dupont! 2tt4740
) was screen-printed and fired, and the temperature resistance characteristics (TCR) of each resistor were compared with a60℃9.
Table 2 shows the measurement results of the rate of change in resistance after being left for 1000 hours in a humidity atmosphere of 0 to 95% RH and in a heat-resistant atmosphere of 70°C.

(See margin below) As is clear from the above, in Example 2, the resistor can be fired in an extremely short time. In addition, the first
The figure is a schematic diagram of high-frequency induction heating in an embodiment of the present invention, in which 1 is a high-frequency power source, 2 is a copper metal tube through which cooling water is flowing, 3 is a metal plate made of aluminum or the like, and 4 is the metal plate 3. The insulating layer coated on top, 5 is the electrode paint provided on the insulating layer 4, 6 is the same (resistance paint), and 7 is the atmospheric temperature control using hot air or infrared rays to keep the ambient temperature constant. It is an adjustable heater.

Effects of the Invention As is clear from the above examples, the present invention involves applying electrode and/or resistance paints onto a metal substrate having an insulating layer on its surface, and directly applying each of the paints from inside the substrate by high-frequency induction heating. By firing, it is possible to achieve an extremely short firing time. Furthermore, since the firing time is extremely short, there is no need for heavy and large firing equipment during mass production as in the past, and this has the effect that both the space and the equipment can be made compact.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of high frequency induction heating in one embodiment of the present invention.

Claims (2)

[Claims] (1) Coating an electrode paint and/or resistance paint on a metal substrate having an insulating layer on its surface, and heating the metal substrate using high frequency induction to bake the electrode paint and/or resistance paint. A method for manufacturing a resistor characterized by: (2) The method for manufacturing a resistor according to claim 1, characterized in that the electrode paint and/or the resistor paint is fired by simultaneously using high-frequency induction heating and hot air and/or infrared heating.