CN100362606C - Small-volume capacitor used for decade capacitor box - Google Patents

Abstract

The present invention relates to a small-volume capacitor used for a decade capacitor box. The present invention is obtained by cutting out a double printed plate and is formed by leading conducting wires which are welded on each copper foil; the present invention is convenient for getting materials and is easy to correct indication values correctly; the capacitance value is between 1PF and 30PF; the present invention which is used as an element can solve the situation that a decade capacitor which has the stepping values of 10PF and 1PF doesn't exist.

Description

The low value capacitor that is used for decade capacitance box

The present invention relates to the adjustable instrument of a kind of output capacitance value, particularly the capacitor of instrument.

University physics, chemical experiment at present often needs the decade capacitance box of minimum step value less than 100PF, particularly solution dielectric constant measurement to advance electric capacity measuring tank minimum step value to ten to require to accomplish 1PF.The decade capacitance box minimum step value of current domestic all manufacturer production that produce instruments is 100PF; Its reason is that its capacity is more than 1000PF if use thin-film capacitor; Adopt mica condenser, though can accomplish about 10PF, through crisp by the mica sheet after silver, the roasting, be difficult to repair standard, because each step value of decade capacitance box all has required precision, this point has restricted mica condenser and has used on the low capacity step disc; The ceramic disc capacitor device is mainly used in High frequency filter, and under the 1KHZ frequency, ceramic disc capacitor indicating value under different temperatures, humidity changes too greatly, can not use; What be left to adopt is air capacitor, but its volume is too big, and costs an arm and a leg, and can only make the monodrome standard capacitor.

Can't buy 10PF, the 1PF step value capacitor that is used for decade capacitance box on the market in order to solve, the present invention is the double-clad board that was used to connect electronic devices and components originally a material, it is cut into of certain area, the Copper Foil lead of respectively burn-oning in two sides is drawn, promptly become a low value capacitor, its capacitance all can be produced in 1PF～30PF scope by the decision of area size.Its capacitance can be under measuring instrument monitors be repaiied standard with the file part area of rasping away, then paint-dipping drying.

Because the distance between two Copper Foils of double-clad board has 1mm, same capacitance adopts the double-clad board area big, and this is favourable to repairing accurate indicating value; Simultaneously, the substrate intensity of its epocel plate is big, and repairing that standard gets up can not be broken, breaks the rate of finished products height; Because epocel plate thermal coefficient of expansion is little, insulate, it is little to make the capacitor temperature coefficient with it, and loss is low.

For ten indicating values of each step disc 1～10 of decimal point capacitive, can carry out parallel connection by the electric capacity that makes, or obtain by the structure of switch itself is in parallel.

Claims (1)

1. low value capacitor that is used for decade capacitance box, two electrodes that are made of two-layer Copper Foil and the insulating barrier between two Copper Foils constitute, wherein two electrodes each draw with lead, it is characterized in that insulating barrier between two-layer Copper Foil and the two-layer Copper Foil is to be intercepted by the double-clad board that is used to connect electronic devices and components.