JPS5933801A - Thin film resistor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a thin film resistor used for modifying resistance values while monitoring circuit characteristics in hybrid integrated circuits and the like.

In recent years, the demand for electronic devices having highly accurate circuit functions has been increasing. Particularly in hybrid integrated circuits, highly accurate functions are achieved by adjusting resistors using, for example, a laser while directly monitoring the desired function. For this reason, requirements for adjustment accuracy have become extremely strict. For example, when adjusting the gain of the operational amplifier shown in Figure 1, the gain G is determined by the external resistor R connected between terminals 1 and 2, and the external resistor R Since the resistance R/stitch is determined by the ratio R//Ri of )1/ and R1, it is necessary to adjust this ratio accordingly.

Conventionally, only the resistances of Ri and R/ were adjusted independently,
Therefore, in adjusting the resistance ratio of R//Ri, if the gain is to be increased, the denominator L(i) should be left unchanged (since it cannot be made smaller) and the numerator R/ should be increased. In this case, the adjustment sensitivity directly depends on the resistance adjustment sensitivity of R/, so there is a drawback that very fine adjustment is not possible.

An object of the present invention is to provide a thin film resistor whose adjustment sensitivity can be arbitrarily selected in the adjustment of the resistance ratio as described above, and which can therefore be adapted to large-scale adjustment or extremely precise adjustment.

The thin film resistor of the present invention has a configuration including a plurality of coarse resistors having coarse adjustment pieces and a shared thin film resistor having a fine adjustment piece commonly connected to these resistors.

Next, the present invention will be explained by examples.

FIG. 2 is a half view of one embodiment of the present invention. In FIG. 2, between terminals 11 and 13 corresponding to terminals 1 and 3 in FIG. Sandwiched between the resistors 4 and 5, it has a rectangular pattern pattern adjusting piece, which is commonly connected to the coarse adjusting resistors 4 and 5 on both sides of the bottom of the rectangular pattern, and is connected to the coarse adjusting resistors 4 and 5 at the top of the rectangular pattern. A common fine-tuning thin film resistor 6 is provided which is connected to the terminal 12 at the side.

Such a resistor is connected to terminal 1 of the operational amplifier shown in FIG.
, 2.3, if terminals 11° and 12.13 are connected, gain G = about t/Ri = ! In order to satisfy the same relationship as t', in the rough adjustment, ladder patterns 4 and 5 are trimmed and the respective resistance values R and R2 are adjusted by trimming traces 4a and 5a so that they are equal when t' is different. Trimming trajectory 6 on fine adjustment piece 6
Make final adjustments as per step a. For example, by coarse adjustment R1
If R2 is slightly larger than R2, trimming is performed at a position where the trimming locus 6a of the fine adjustment piece 6 is slightly shifted below the center. And the trimming sensitivity in this case,
That is, R for a certain length of the trimming trajectory 6a
The change in 13/R11 is naturally proportional to the deviation 9 from the center of the trimming trajectory 6a. Therefore, if precise adjustment is desired, by trimming at a position closer to the center, precise trimming can be performed with proportionally gentler trimming sensitivity. If Rr<几2, trimming is performed by shifting the trimming locus 6a upward. In this way, precise trimming can be performed to "11" R13. In addition, if you want to change the ratio of R13 and R11 to make the amplification degree different from 1, adjust R13/Ro to a value close to the desired resistance ratio by trimming coarse adjustment thin film resistors 4 and 5. However, if the trimming position of the fine adjustment shared resistor 6 is selected appropriately and trimmed, the desired resistance ratio, that is, the desired amplification degree can be obtained with extremely high precision due to the extremely dull trimming sensitivity. Can be trimmed.

[Brief explanation of the drawing]

Figure 1 shows an arithmetic amplifier 1- with an external resistor for gain change.
FIG. 2 is a plan view of an embodiment of the present invention. 1.2, 3, 11, 12.13... terminal, 4,
5... Ladder pattern coarse adjustment thin film resistor, 6...
...Fine adjustment shared thin film resistor, 4a, 5a, 6a...
...Trimming trajectory. 5- Figure 2

Claims (1)

[Claims] A thin film resistor comprising: a plurality of coarse adjustment thin film resistors having coarse adjustment pieces; and a shared thin film resistor having a fine adjustment piece commonly connected to the coarse adjustment thin film resistors.