Carbon oil in use for making carbon resistance element, preparation method, and prepared element of carbon resistance

Abstract

The carbon oil is composed of current conducting padding, rosin joint material, cross-linking agent, and solvent. The padding includes carbon black, metal powder or mixture of powder of electroconductive metallic compound. The said metal powders can be powders of nickel, silver, gold, aluminum, zinc, tin or stainless steel. Mixture of powder can be nickel oxide, tin oxide, indium oxide, niobium oxide or iron phosphide. Features are: simple technique, narrow distribution range of numerical value of resistance in mean square. The invention overcomes defects of pinholes, cracks etc. in final product so as to raise capability of product and stability of carbon resistance element.

Description

Technical field [0001] The invention belongs to the technical field of resistors, and relates to a carbon oil used for making a carbon resistance element, a preparation method thereof, and a carbon resistance element made by using the carbon oil. Background technique [0002] The traditional preparation method of carbon resistance element includes: dispersing a certain amount of conductive carbon black in a thermosetting resin solution to prepare a paste, namely carbon oil, and then applying the carbon oil to FR1, FR2, FR4, etc. by screen printing. The surface of the rigid printed circuit board substrate is formed with a pattern of a certain shape and size, and finally heated to evaporate the solvent and further heated to 100-180°C to cure the resin, thereby forming a carbon resistance element. [0003] Generally speaking, as the content of carbon black in the carbon oil increases, the conductivity of the system increases and the resistance value decreases, but the resistance cha...

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Problems solved by technology

For example, it is necessary to prepare carbon oil with a square resistance of 300 ohm / square / 25μm±10%, then choose carbon oil with a square resistance of 400 ohm / square / 25μm±10% as the main component, and use it to combine with the square resistance The carbon oil product of 40 ohms / square / 25μm±10% is mixed in a certain proportion to prepare the carbon oil with the required square resistance value. On the one hand, it is necessary to conduct additional experiments to determine the ratio of the two carbon oils. The process is relatively On the other hand, due to the uniformity of mixing, the resistance range of carbon oil after mixing becomes wider, for example, from the original ±10% to ±20% or wider. In addition, the air bubbles introduced during the mixing process will be in the Defects such as pinholes and cracks are formed in the final carbon resistance element, thereby destroying the performance of the product and the stability of the product resistance value

That is to say, the problems existing in the prior art are: the preparation process is relatively cumbersome, the resistance value distribution range of the formed carbon resistance element is wide due to the uniformity of mixing, and the air bubbles introduced during the mixing process will introduce needles into the final product. Defects such as holes and cracks will destroy the performance of carbon resistance components and the stability of product resistance

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