JPH0548922B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for trimming a resistive film formed on an insulating substrate constituting a hybrid integrated circuit or the like.

(Prior Art) In a hybrid integrated circuit, for example, a pair of electrodes 2, 2 provided on an insulating substrate 1 as shown in FIG.
A resistive film 3 is formed across the gap by screen printing or the like. This resistive film 3 is normally connected to the electrodes 2 and 2 from its ends in order to adjust its resistance value.
A slit 4 is formed along the . In this case, the position for forming the slit 4, that is, the trimming position, is selected near the center of the resistive film 3 in order to prevent the electrodes 2, 2 from being cut and causing a connection failure.

(Problem to be solved by the invention) However, as shown in Figure 3, when trimming a resistive film, the variation in resistance value is smaller when trimming at a position closer to the electrode than when trimming near the center. As a result, it becomes more desirable. That is, FIG. 3 shows the rate of change in resistance of the resistive film 3 with respect to the trimming length L when the trimming position is changed. The resistance change rate here is calculated by the following formula. In other words, resistance change rate = (resistance value after trimming - resistance value before trimming) resistance value before trimming Also, the curve in the figure is the one obtained by trimming near the center of the resistive film 3, and the curve in is close to the electrode. It is cropped at the position. Of these curves, the slope of the curve trimmed close to the electrode is smaller, and this suggests that trimming closer to the electrode allows for finer adjustment and less variation. Ru.

However, conventionally, since the trimming position is determined simply by visual measurement, the trimming position inevitably deviates from the planned position, and if trimming is performed at a position close to the electrode, there is a risk of cutting the electrode 2.

The present invention has been made in view of these points, and aims to provide a trimming method that can reliably trim the resistive film at a position close to the electrode and adjust the resistance value with high precision. .

(Means for solving the problems) In order to achieve such an object, the present invention has the following features:
It is characterized in that a notch is provided at the end of a resistive film formed between a pair of electrodes provided on an insulating substrate at a position close to the electrode, and a slit is formed in the resistive film aiming at this notch.

(Function) Since the slit is formed aiming at the notch provided in the resistive film at a position close to the electrode, the accuracy of the slit formation position is improved and the rate of change in resistance due to trimming is reduced.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings. FIG. 1 is a plan view showing the main parts of an insulating substrate constituting a hybrid integrated circuit or the like. In the figure, reference numeral 11 denotes an insulating substrate made of alumina or the like, and a pair of electrodes 12, 12 are provided at predetermined positions on the insulating substrate 11. A resistive film is formed across the pair of electrodes 12, 12 by means such as screen printing. 13 is formed. This resistive film 13 has a triangular minute notch 14 formed in advance at the end near one of the electrodes 12, and the present invention is directed to this notch 14.
The slit 15 is formed aiming at the hole 4.
Note that the shape of the notch 14 is not necessarily limited to the above-mentioned shape, and may have other shapes.

As described above, according to the method of the present invention, it is possible to reliably trim the resistive film 13 to a position close to the electrode, unlike the conventional trimming performed simply by visual measurement. In addition, the material of the resistive film 13 can be reduced by the amount corresponding to the notch 14, and the notch 14 can be used not only for visual inspection, but also as a sensor target, which is useful for realizing trimming automation. It can also be useful.

(Effects) The method for trimming a resistive film of the present invention is as described above, and since the slit is formed aiming at the notch provided in the resistive film near the electrode, the rate of change in resistance due to trimming is reduced. Therefore,
This makes it possible to finely adjust the resistance, reduces variations in the trimming process, and improves the accuracy of resistance value adjustment.

Furthermore, if a slit is formed at such a position, it is possible that the electrode will be cut, but this inconvenience occurs because the notch that is the target of the slit formation is formed in the resistive film. Not at all.

[Brief explanation of the drawing]

FIG. 1 is a plan view of main parts for explaining an embodiment of the trimming method according to the present invention, FIG. 2 is a plan view of main parts for explaining a conventional trimming method,
FIG. 3 is a graph illustrating the relationship between trimming length and resistance change rate. 11...Insulating substrate, 12...Electrode, 13...Resistive film, 14...Notch, 15...Slit.

Claims (1)

[Claims] 1. A notch is provided at the end of a resistive film formed between a pair of electrodes provided on an insulating substrate at a position close to the electrode, and a slit is made in the resistive film aiming at this notch. A method for trimming a resistive film, the method comprising: forming a resistive film;