JPH01321602A - Method of trimming film resistor - Google Patents

Abstract

PURPOSE:To arrange the constitution such that more accurate trimming becomes possible, and highly accurate resistance value can be obtained, and it does not produce much secular change of a resistance value by cutting the specified positions of the first resistance film and the second resistance film of a film resistor in the form of a lattice. CONSTITUTION:When resist films 4-9 straddling a pair of electrode conductors 1 and 2 are cut at the specified positions, current paths flowing between the electrode conductors 1 and 2 are interrupted there partially, and the currents come to flow bypassing the second resistant film 10-15 crossing the first resistant films 4-9. For that reason, the current path becomes long, and the change of the resistance value between a pair of electrode conductors 1 and 2 becomes greater than that by the cut of the second resistant films 10-15. Accordingly, by cutting the first resistant films 4-9 of a film resistor 3 formed in lattice shape at the beginning at the specified positions, rough adjustment of resistance values can be done, and next by cutting the second resistance films 10-15 at the specified positions, fine adjustment of the resistance value can be done. Hereby, highly accurate trimming becomes possible, and highly accurate resistance value can be obtained, and secular change of the resistance value also becomes small.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for trimming a film resistor provided between a pair of electrode conductors facing each other on an insulating substrate.

(Conventional Technology) As shown in FIG. 3, a conventional film resistor is provided with a pair of electrode conductors 21 and 22 facing each other on an insulating substrate (not shown). Film resistor 2 between ゜22
3. Such a membrane resistor 2
3 is formed on a chip-shaped insulating substrate to configure a chip resistor, or formed on an insulating substrate on which various electronic components are mounted to configure a hybrid integrated circuit. Usually, in order to obtain a desired resistance value for such a film resistor, double cut trimming as shown in Fig. 4, triple cut trimming as shown in Fig. 5, and triple cut trimming as shown in Fig. 6 are performed. Trimming such as pear cut trimming as shown is performed.

(Problem to be Solved by the Invention) However, in the conventional trimming method as described above, the resistance value per unit area is almost uniform in any region of the film resistor, so the amount of change in resistance value with respect to the amount of trimming is is always the same, and there is a problem that there is an unavoidable limit to performing highly accurate trimming. Further, there is also the problem that microcracks are likely to occur at the end portion of the trimming, and that the microcracks develop during use, resulting in a change in resistance value.

The present invention has been made in view of the above problems, and includes:
It is an object of the present invention to provide a method for trimming a film resistor that enables more accurate trimming, thereby obtaining a highly accurate resistance value, and in which the resistance value hardly changes over time.

(Means for Solving the Problems) In order to achieve such an object, the present invention provides a membrane resistor provided between a pair of electrode conductors facing each other on an insulating substrate. A lattice-like structure consisting of a plurality of linear first resistive films that straddle the plurality of stripes, and a plurality of linear second resistive films that cross the plurality of stripes of the first resistive film and connect them in parallel to each other. The first resistive film of the lattice-shaped film resistor is first cut at a predetermined location, and then the second resistive film is cut at a predetermined location.

(Function) According to this configuration, since the membrane resistor is formed in a lattice shape, a plurality of strips are provided spanning between a pair of electrode conductors. Even if the second resistive film that crosses the resistive film is cut at a predetermined point, the first resistive film is always connected in parallel somewhere, so there is no connection between the pair of electrode conductors. The change in resistance value is not so large. However, when the first resistive film spanning between a pair of electrode conductors is cut at a predetermined location, -
The current path flowing between the pair of electrode conductors is then partially interrupted, allowing the current to bypass the second resistive film that traverses the first resistive film. Therefore, the current path becomes longer and the resistance value change between the pair of electrode conductors becomes larger than that caused by cutting the second resistive film. Therefore, the resistance value can be roughly adjusted by first cutting the first resistive film of the membrane resistor formed in a grid shape at a predetermined position, and then by cutting the second resistive film at a predetermined position. This allows for more precise trimming. Furthermore, since the linear resistance film is cut and trimmed, microcracks are not formed in the film resistor.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings. FIG. 1 is a plan view of a film resistor according to an embodiment of the present invention, in which a pair of electrode conductors 1 are arranged facing each other on an insulating substrate made of alumina or the like (not shown).

2 is provided. These electrode conductors 1.2 are formed, for example, by printing and baking Ag--Pd paste. A grid-shaped membrane resistor 3 is provided between the pair of electrode conductors 1.2. This lattice-like membrane resistor 3 consists of a plurality of linear first resistance films 4.5.6.7.8.9 extending between a pair of electrode conductors 1.2 and a first resistance film of these plurality of stripes. It is formed from a plurality of linear second resistance films 10.11, 12, 13, 14.15 which cross the resistance films 4, 5, 6, 7, 8.9 and connect them in parallel. For example, it is formed by printing and baking a cermet resistance paste such as ruthenium oxide. The first resistive film and the second resistive film may be formed by one printing process or separately by two printing processes. In order to trim the film resistor 3 formed in a lattice shape in this way, first, the first resistive film 4.5.6.7.8.9 spanning between a pair of electrode conductors 1.2 is trimmed. The predetermined locations, for example, the first resistive films 4, 5, as shown in FIG.
It is cut between the second resistive films 11 and 12 of No. 6 to approximate the desired resistance value. Next, the first resistive film 4.5.6.

7.8.9 across the second resistive film 10, 11.12°13.14.15 at a predetermined location, for example, the second resistive film 12, 13.14 as shown in FIG. A desired resistance value is obtained by cutting between the resistive films 6 and 7 of No. 1. In other words,
By cutting the first resistive film at a predetermined location, the current path in the first resistive film is partially cut off,
Since the current flows bypassing the second resistive film, the current path becomes longer and the resistance value between the pair of electrode conductors 1.2 increases. Therefore, the resistance value can be roughly adjusted by sequentially blocking the first resistive film so as to approach the desired resistance value as much as possible. In addition, by cutting the second resistive film at a predetermined location, the electrode conductor 1
．． The resistance value between the two increases, but since the first resistive film is always connected in parallel at some point, including the electrode conductor 1.2, the resistance value change occurs when the first resistive film is cut. It will be smaller than. Therefore, the resistance value can be finely adjusted by sequentially blocking the resistance films of nodes 2 so as to get as close to the desired resistance value as possible.

Note that, rather than the first resistive film 4.5.6.7.8.9 that spans between the pair of electrode conductors 1.2, the second resistive film that crosses them! 0,11,12,13゜14.15
If a resistive material with a high resistance value per unit area is used for the first resistive film, the resistance value change range when the first resistive film is cut becomes larger, but the resistance value change range when the second resistive film is cut becomes larger. becomes smaller, allowing more fine adjustments. In this case, it goes without saying that the first resistive film and the second resistive film need to be formed separately.

In addition, among the first resistive films 4.5.6.7.8.9, for example, resistive materials having a higher resistance value per unit area are used for 6.7.8 and 9 than for 4 and 5. At the same time, the second resistive film! 0,11,12゜13.14.15
For example, 10.11 and I2, 13, 14. and a configuration in which a resistive material having a higher resistance value per unit area than 15 is used, and a resistive material having a higher resistance value than any of the first resistive films is used for both of the second resistive films. You can also use it as Even in such a case, the first resistive film is still trimmed first and the second resistive film is trimmed later, but the resistive film with the lowest resistance value among the first resistive films is trimmed first, If the resistive film with a high resistance value is trimmed later, rough adjustment of the resistance value becomes easy. Furthermore, if the resistive film with the lower resistance value among the second resistive films is trimmed first and the resistive film with the higher resistance value is trimmed later, fine adjustment of the resistance value becomes easier.

(Effects) As is clear from the above explanation, according to the present invention,
forming a membrane resistor in a lattice shape consisting of a first resistive film spanning between a pair of electrode conductors and a second resistive film crossing the first resistive film, first cutting the first resistive film; Next, the second resistive film is cut and trimmed, making it possible to perform highly accurate trimming and obtain a highly accurate resistance value.Furthermore, it is possible to prevent microcracks from occurring during trimming, thereby improving the resistance value. This has the excellent effect of reducing changes over time.

[Brief explanation of the drawing]

1 and 2 are plan views of a membrane resistor for explaining the trimming method of the present invention, and FIGS. 3 to 6 are plan views of a membrane resistor for explaining the trimming method of the conventional example. be. 1.2... Electrode conductor, 3... Film resistor, 4, 5, 6
, 7° 8.9... first resistive film, 10, 11. +2
．． 13,14.15...Second resistance film.

Claims (1)

[Claims] (1) A film resistor provided between a pair of electrode conductors facing each other on an insulating substrate is connected to a plurality of linear first resistance films spanning between the pair of electrode conductors, and a plurality of linear first resistance films extending between the pair of electrode conductors. A plurality of linear second resistance films are formed across the first resistance film and connected in parallel to each other, and the first resistance film of this lattice-shaped film resistor is first A method for trimming a film resistor, the method comprising: cutting a predetermined portion of the second resistive film, and then cutting a predetermined portion of the second resistive film.