KR920003074Y1 - Circuit of trimming resistor - Google Patents

Abstract

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Description

Trimming Resistance Network

1A is an electric circuit diagram showing a first embodiment of a trimming resistance network according to the present invention, and FIG. 1B is a partial circuit diagram for explaining the operation of the trimming resistance network according to the first embodiment.

FIG. 2 is a circuit diagram partially modified from the network of FIG. 1a. FIG.

Figure 3a is an electric circuit diagram showing a second embodiment of the trimming resistance network according to the present invention, Figure 3b is a partial circuit diagram for explaining the operation of the trimming resistance network according to the second embodiment.

Figure 4 is an electrical circuit diagram showing a specific example of the trimming resistance network according to the present invention shown in Figure 1a.

5 is an electric circuit diagram showing a specific example of the trimming resistance network according to the present invention shown in FIG. 3a.

6 is a plan view for explaining the factors for determining the resistance value of the film resistor.

FIG. 7A is an electric circuit diagram illustrating a conventional trimming method for changing the resistance value, and FIG. 7B is a plan view in which a conventional trimming film resistor is ditched.

8 and 9 are electrical circuit diagrams for explaining the problems of the conventional trimming resistance network.

* Explanation of symbols for main parts of the drawings

11, 51: first resistor R ₁ , R ₅₁ 11a, 51a: first connection terminal

11b and 51b: second connection terminal 12 and 52: first series resistor R ₂ and R _2q

13, 56: 1st connector 14, 57: 2nd connector

15: Parallel trimming resistor (R ₃ ) 17: Inverted "L" shaped resistor

18, 53: second series resistor (R ₄ , R _2n ) 54: third series resistor (R _2n )

55: fourth series resistor (R ₂₁ ) 58 _m , 58 _n , 58 _q : parallel trimming resistor group

T ₁ , T ₃ : Terminal for first external connection T ₂ , T ₄ : Terminal for second external connection

[Industrial use]

The present invention relates to a trimming resistor of a thin film or thick film integrated circuit, and more particularly, to a trimming resistor network used in an output characteristic adjusting device such as a constant voltage power supply device or an analog / digital converter.

[Traditional Technology and Problems]

In recent years, functional trimming has come into the spotlight in semiconductor integrated circuits and hybrid integrated circuits as a means for obtaining high-precision output characteristics.

On the other hand, in the trimming using a laser beam, since light is used, trimming can be performed without being electrically connected to the physiothermic agent.

Therefore, in the case where the main factor for determining the output characteristics of the circuit is, for example, resistance, the resistance is set to an appropriate initial value, the circuit is put into an operating state, and the resistor is cut or processed with a laser beam while measuring the output characteristic. It is possible to adjust the resistance value until the characteristic to be obtained is obtained to obtain a high-precision output characteristic. This method is called functional trimming.

Along with the above-described functional trimming, various trimming methods for changing the resistance value have been proposed, but basically the following two kinds of methods are mainstream. One method includes a short bar 2 arranged in parallel with the diffusion or thin film resistor 1 connected in series as shown in the electrical circuit diagram of FIG. 7A, and the short bars are sequentially cut (x). Display) to change the resistance between the two terminals (A, B). Another method is as shown in Fig. 7B, wherein the same figure is a plan view of the film resistor 4, and reference numeral 3 denotes a metal electrode. That is, in this method, the groove | channel 5 is formed in the resistive film 4, and a resistance value is changed by changing the direction of the electric line of force in a film | membrane.

Hereinafter, the problem of the prior art will be described taking function trimming in a semiconductor integrated circuit as an example.

In FIG. 7A, as the shorting bar 2, a metal material for electrode wiring such as aluminum (hereinafter referred to as Al) is mainly used. Since these metals have a high thermal conductivity and a large light reflection coefficient, the shorting bar 2 ), It is necessary to increase the power of the laser light in order to generate heat, melt and cut it. Therefore, when this shorting bar 2 is provided in one area of a semiconductor integrated circuit and laser trimmed, laser light is also irradiated to the shorting bar 2 under the ground layer at the same time as the cutting bar. The semiconductor substrate may also be destroyed. In addition, since the reflectance changes due to the slight difference of the metal surface state in the shorting bar forming step, the power condition of the laser light required for cutting is varied, so that it is extremely difficult to achieve stable trimming at all times without destroying the underlying layer.

On the other hand, in the metrology processing method shown in FIG. 7B, the film resistor 4 can be processed without destroying the underlying layer by using a material having a lower thermal conductivity than a metal, such as polysilicon, but the processed fractured part ), Micro cracks (6) are produced together, and these micro cracks (6) are more likely to become larger due to heat or mechanical pressure, or to change moisture over time by absorbing moisture. By the way, in the circuit which performs high precision output adjustment by function trimming, the time-dependent change of a resistance value becomes a fatal problem. Therefore, in order to prevent the occurrence of the change over time, a thin film resistor network connected in parallel to prevent the electric line of force from extending is provided, and a method of changing the resistance value by sequentially cutting the membrane resistor is used. In this case, for example, when the trimming film resistors having the same resistance value are connected in parallel, the amount of change in the resistance value does not become constant at each cutting.

For example, as shown in FIG. 8, the initial resistance value between the terminals A and B when 10 10 막 membrane resistors are connected in parallel is 1 ,, and when the next one is cut, 0.1 Ω increases, but the last remaining 2 When one of the pieces is cut, the resistance between the terminals A and B changes from 5 kV to 10 kV, and the change amount is 5 kV. Therefore, in this system, it is difficult to change the resistance value as required.

On the other hand, even in the parallel circuit, it is possible to make the variation in resistance constant during each cutting. In other words, Fig. 9 is a diagram showing an example of a network capable of changing the resistance value by 1 Hz from 1 Hz to 10 Hz, where the initial value of the combined resistance between the terminals A and B is 1 Hz. Thereafter, by sequentially cutting the resistance from the left side to the right side of the same figure, it is possible to change the synthesized resistance value by 10 mV by 1 mV. In this method, however, a change in resistance with time due to a minute crack does not occur, but an enormous area is required in order to form a film resistor having a predetermined resistance value from 2 kPa to 90 kPa, and thus the size of the semiconductor integrated circuit device chip. Since the product price increases due to the increase, there is a shortage in practical use.

The conventional method for changing the resistance value of the trimming resistor has the disadvantages as described above. That is, in the short-bar cutting method of a conductor having good thermal conductivity as shown in FIG. 7a, the underlying layer and the semiconductor substrate itself may be destroyed. In the resistive film grooving method of FIG. There is a drawback to being prone to change. In addition, as shown in FIG. 8, in the method of connecting the film resistors in parallel, cutting them sequentially and trimming, the drawback of generating small cracks is improved, but the amount of change in the resistance value is not constant every time the cutting is performed. Problems remain, as the resistance value may change significantly beyond the amount of change required for adjustment. In addition, in the method of FIG. 9, although a certain amount of change necessary for the above characteristic adjustment is obtained, the difference in the required resistance values of the film resistors constituting the network is large, and an enormous area is required for the formation of the film resistors, which is inappropriate for practical use.

[Purpose of designation]

The present invention has been made in view of the above circumstances, and it is possible to trim without destroying the lower layer of the trimming resistor, and to eliminate the defect that causes a change in resistance over time due to a small crack during trimming. In addition, the object of the present invention is to provide a trimming resistor network that can constantly change the resistance value and can be designed with a small footprint.

[Composition of design]

In order to achieve the above object, a trimming resistance network according to the present invention includes a first connector 13 having a plurality of first series resistors 12 having a resistance value r ₂ connected in series, and the first connector ( The first external connection terminal T ₁ provided at one end of the terminal 13, the first end connected to the other end of the first connector 13, and the first resistor 11 having a resistance value r ₁ , and the first resistor. Is connected between an interconnection point to the one series resistor 12 and the other end of the first resistor 11 and between the one end of the first connector 13 and the other end of the first resistor 11, each of which is a resistance value. and a plurality of parallel trimming resistors 15 having (r ₃ ) and a second external connection terminal T ₂ provided at the other end of the first resistor 11, wherein the resistors r ₁ and resistance values are provided. between (r ₂ ) and resistance (r ₃ )

A relationship of {(r ₁ + r ₂ ) · r ₃ } / (r ₁ + r ₂ + r ₃ ) = r ₁ is characterized.

In addition, the parallel trimming resistor of the trimming resistance network according to the present invention is a polysilicon film doped with impurities, a nickel-chromium alloy film, a tantalum metal film, a polyimide organic film, and an acrylonitrile organic film. Or a resistive film of any one of ruthenium oxide films.

[Action]

The operation of the trimming resistor network according to the present invention configured as described above will be described in detail based on specific examples.

FIG. 1a shows a trimming resistance network according to the present invention, which is a two-terminal network having a first external connection terminal T ₁ and a second external connection terminal T ₂ . The first resistor 11 (hereinafter referred to as resistor R ₁ and its resistance value is referred to as r ₁ ) is connected to the termination of this network. In addition, the terminal T ₁ and the terminal T ₂ and the resistor R ₁ are connected by first and second connectors, and as shown in FIG. 1B, a first series resistor 12 (R) is shown. ₂ , the "L" shaped resistor 17 (part surrounded by the broken line) formed by connecting one end of the resistance value r ₂ and one end of the parallel trimming resistor 15 (resistance R ₃ , resistance value r ₃ ) to the unit stage. As a result, multiple stages (6 stages in this drawing) of the resistor 17 are cascaded. Here, the other end of the resistor R ₂ is referred to as the third connection terminal 17a, the other end of the resistor R ₃ is referred to as the fourth connection terminal 17b, and the resistor R ₂ and the resistor R ₃ are referred to as the third connection terminal 17a. Let the said ends connected to each other be the 5th connection end 17c.

When the third connecting end 17a of the inverted " L " shaped resistor 17 is disposed at the end and is installed, it is connected to the first connection end 11a of the resistor R1 and is disposed outside the end. If installed, it is connected to the fifth connecting end 17c of the next stage.

The fourth connection terminal 17b is integrally connected to the second connection terminal 11b of the terminal T ₂ and the resistor R ₁ via the second connector 14. On the other hand, a second series resistor 18 (resistor R ₄ , resistance r ₄ ) is inserted between the terminal T ₁ and the fifth connection terminal 17c of the resistor 17 at the first stage. Here, the combined resistance value r seen from the resistor R ₁ side between the fifth and fourth connection terminals of each stage is always designed to be r ₁ . That is, r ₁ and r ₂ and r ₃ are r = {(r ₁ + r ₂ ) · r ₃ } / {(r ₁ + r ₂ ) + r ₃ } = r. … It is designed to satisfy (1).

X mark in FIG. 1 shows a trimming resistor and shows that it is cut by trimming.

In the trimming resistor network configured as described above, the combined resistance value between the terminal T ₁ and the terminal T ₂ is a parallel trimming resistor from the initial value r ₄ + r ₁ to the final value r ₄ + r ₁ + 6r ₂ . Whenever one is sequentially cut toward the first resistor from the side close to the terminals T ₁ and T ₂ , the value R ₂ is substantially increased. Here, the resistor R ₂ determines the step change width r ₂ of the change amount of the combined resistance between the terminals T ₁ and T ₂ , and the number of stages of the inverse "L" shaped resistor 17 is Determine the full range of variation. The resistance (R ₄₎ may be omitted in the case of geotinde for determining the initial value of the combined resistance, limiting the functionality of the network only by the resistance correction.

The resistance values of the resistors R ₁ and R ₃ need to satisfy the above formula (1), and when r ₂ is predetermined, one of r ₁ , r ₃ or their ratio (r ₁ / Since r ₃ ) can be freely determined, the values of r ₁ and r ₃ can be selected so as to minimize the occupied area of the present network in consideration of design conditions, manufacturing conditions, and the like.

The trimming resistor network shown in FIG. ₂ is a part of the resistor R ₂ of the first series resistor 12 distributed to the second connector 14 in the network shown in FIG. 14 illustrates a case connected to the second connecting end (11b) of the first resistor 11 to the serial-mediated resistance from the external connection terminals 2 (T _2).

In the same figure, r _2a = pr ₂ , r _2b = (1-p) · r ₂ , and p is a value smaller than 1 for determining the distribution ratio, and the desired value can be selected according to design conditions, manufacturing conditions, and the like. In FIG. 2, the same reference numerals as those of FIG. 1 denote the same or corresponding parts, and the operation of such parts is almost the same as that of FIG.

Figure 3a is an electrical circuit diagram showing a second embodiment of the trimming resistor network according to the present invention.

The network according to the second embodiment is a two-terminal network having a first external connection terminal T ₃ and a second external connection terminal T ₄ , and includes a first resistor 51 (resistance R ₅₁ , resistance r ₅₁ ). Is connected to the end of this network. The network includes a first series resistor 52 (resistance R _2q , resistance value r _2q ), a second series resistor 53 (resistance R _2n , resistance value r _2n ), and a third series resistor 54 (resistance R _2m , resistance value r _2m ). The first connector 56 connecting the first connection terminal 51a of the terminal T ₃ and the resistor R ₅₁ via a fourth series resistor 55 (resistance R ₂₁ , resistance r ₂₁ ) is provided. In addition, a second connecting body 57 for connecting the terminal T ₄ and the second connecting end 51 b of the first resistor 51 in series is provided. In addition, parallel trimming resistor groups 58 _m , 58 _n , 58 _q are connected to both ends of the first connector 56 and the second connector 57, respectively.

The parallel trimming resistor group 58 _{m is} connected to _m trimming resistors of parallel trimming resistors R ₃₁ , R ₃₂ ,..., R _{3m in} parallel, as shown in FIG. 3B. When cutting one by one, the combined resistance between the terminals T ₅ and T ₆ increases by a constant value r ₀ . However, the resistance values r ₃₁ , r ₃₂ , r ₃₃ , ..., r _{3m of the} resistors R ₃₁ , R ₃₂ , R ₃₃ , ..., R _3m are respectively (1 × 2) · r ₀ , (2 × 3). _{) · r 0, (3 ×} 4) · r 0, ... , m · (m + 1) · r ₀ . The resistance of the resistor R _2m is r _2m = mr ₀ .

The parallel trimming resistor group (58 _n) and resistance (R _2n), parallel trimming resistor group (58 _q) and a resistance (R ₂₉₎ of the parallel trimming resistor group (58 _m) and resistance similarly to the resistance value of each resistor In R _2m , the numerical value m is replaced with n or q. The resistance value r ₅₁ of the resistor R ₅₁ is defined as the change width r ₀ of the resistance change. In practice, it is often formed as one resistor 51 having the resistor R _2q and the resistor R ₅₁ resistor r _2q + r ₀ .

In the trimming resistance network having the above structure, the combined resistance value between the terminals T ₃ and T ₄ is changed from the initial value r ₂₁ + r ₀ to the final value [r ₂₁ + r ₀ + (m + n + q) · r ₀ ] Whenever the parallel trimming resistors are sequentially cut one by one from the side close to the terminals T ₃ and T ₄ toward the first resistor 51 side, a constant value r ₀ is increased. The resistance value of the resistance value of the resistance (R ₂₎ is a resistor (R _2m) equal to the former increment (mr ₀₎ of the combined resistance when cutting the parallel trimming resistor group (58 _m) of the front end, after cutting the resistance (R ₂₁₎ is added to the can it is possible to design conditions of the resistance groups (58 _n) connected to the rear end substantially equal to the design conditions of the resistor group (58 _m) of the first stage. The same applies to the resistors R _2n and R _2q .

In general, m, n, and q are about 1 to 3, so that the resistance values of the parallel trimming resistors of the present network are suppressed by 2r ₀ , 6r ₀ , 12r ₀ , and the difference between the resistance values is suppressed. The increase in the chip area to be formed can be avoided. On the other hand, the first resistor 51 is determined by the change width r ₀ of the resistance change, and the resistor R ₂₁ determines the initial value of the combined resistance of the present network, but may be omitted as desired. In addition, as shown in the specific example of FIG. 2, a part of the resistors R ₂₁ , R _2m , R _2n , and R _2q included in the first connector 56 may be provided to each corresponding part of the second connector 57. It does not interfere with insertion. In addition, the number of resistor groups, but in three of _{58 m, 58 n, 58 q} , may be any of the singular as desired.

In addition, the parallel trimming resistor in the present network is a laser beam irradiated by using a material having a lower thermal conductivity than that of a metal of a conventional short-circuit bar, such as a polysilicon film doped with impurities or a nickel-chromium alloy film as a resist film. The power can also be reduced, thereby significantly reducing the breakage of the underlying layer during cutting.

EXAMPLE

Hereinafter, embodiment of this invention is described concretely.

FIG. 4A illustrates an embodiment of the trimming resistor network shown in FIG. 1A as an electric equivalent circuit, and the same reference numerals as those used in FIG. 1 indicate the same or identical details, and thus detailed description thereof will be omitted. . This network is a network for modifying the resistance value by 1 Ω from 1 Ω to 10 Ω by 1 통상. It is usually connected in series with a resistor (not shown) that requires modification and used to correct the resistance to an appropriate value.

Therefore, the resistor R ₄ which determines the initial value is not provided. Here, because the variation range of 1Ω to decrease as r ₂ = 1Ω. To equal the combined resistance value of the resistance (R ₁₎ from the connection end of the inverse of the terminating "L" shaped resistance body (17c), (17b), and r _1, r ₁ and r ₃ are to satisfy the above expression (1) There is a need. That is, substituting 1 into r ₂ of the formula (1) and obtaining the relationship between r ₁ and r ₃ gives the following equation.

From these equations, r ₁ and r ₃ are set to 1 ms and 2 ms, respectively, in consideration of conditions such as design and manufacture. In this embodiment, since the change range is from 1 Ω to 10 Ω, 9-stage cascade connection of the inverse "L" shaped resistor is made.

The combined resistance of the reverse "L" shaped resistor terminal of the final stage (17c) and a resistor (R ₁₎ side (the right side in the figure) from the terminal (17b) it is to 1Ω. In other words, a circuit in which ₁ kV (resistance R ₁ ) is connected to an inverted "L" shaped resistor at the final stage is equivalent to a 1 K resistor. Therefore, the equivalent resistance of 1 kW is connected to the inverted " L " shaped resistor of the 8th stage, so that the network shown in FIG. 4a and the network shown in FIG. 4b are the combined resistance values between the terminal T ₁ and the terminal T ₂ . Equivalent This operation can be repeated toward the first stage, and as a result, the resistance value seen from the connection ends 17c and 17b of all ends of the inverse "L" shaped resistor becomes 1 kΩ.

Accordingly, the combined resistance value between the terminals (T _1, T ₂₎ is 1Ω. Here, when the parallel trimming resistor R ₃ of the first stage is cut off, the combined resistance value between the terminals T ₁ and T ₂ is ₁ 의 of the resistance R ₂ of the first stage and the next stage is seen to the right from the connection terminals 17c and 17b. The resistance value is 1 sum, that is, 2 dB. Whenever the parallel trimming resistor is sequentially cut toward the final end, 1 kΩ of the resistor R ₂ at the front end is added, and the resistance value between the terminals T ₁ and T ₂ is changed by 1 kPa from 1 kV to 10 kV.

FIG. 5a illustrates an embodiment of a trimming resistor network according to the present invention shown in FIG. 3a, and the same reference numerals as used in FIG. 3 denote the same parts or the same details, and thus a detailed description thereof will be omitted. This network is a network that changes the combined resistance between the terminals T ₃ and T ₄ by 1 Ω from 2 Ω to 6 Ω. Therefore, the total number of parallel trimming resistors (m + n + q) is four, and the step change resistance r ₀ is 1 k ?. In this embodiment, as shown in FIG. 5, m = 3, n = 1, q = 0 in consideration of various conditions such as design and manufacturing. The parallel trimming resistor (58 _m ) of the first stage is m = 3, so r ₃₁ = 2 _r0 = 2 ms, r ₃₂ = (2 x 3) r ₀ = 6 ms, r ₃₃ = (3 x 4) r ₀ = 12 ms It consists of three parallel trimming resistors. In addition, the low amount of increase of the combined resistance when parallel trimming resistor group (58 _m) when the first stage is the r _2m = 3Ω because mr ₀ = 3r ₀ = 3Ω. The parallel trimming resistor group 58 _n of the next stage is n = 1, so that one parallel trimming resistor of r ₃₁ = 2r ₀ = 2 ms is used, and r _2n is 1 ms. On the other hand, r ₅₁ of the first resistor ₅₁ is equal to 1 kV as the change resistance value r ₀ . In addition, since the initial resistance value (r ₂₁ + r ₀ ) is 2 Ω, r ₂₁ is 1 Ω. In addition, the resistor R _2n and the resistor R ₅₁ are often formed of one resistor having a resistance value (r _2n + r ₅₁ = 2 kV) as shown in FIG. 4B.

The initial synthesized resistance between the terminal T ₃ and the terminal T ₄ of the network configured as described above (FIG. 5A) is 2 kΩ. Therefore, when one by one is sequentially cut from the parallel trimming resistor on the side close to the terminals T ₃ and T ₄ on the drawing toward the resistor on the right, the combined resistance value between the terminal T ₃ and the terminal T ₄ is constant. It changes by (1 ms) to become the final value (6 ms). Since the number of stages of the parallel trimming resistor group of this network and the number of parallel trimming resistors constituting the resistor group can be selected in consideration of various conditions such as design and manufacture, the degree of freedom is increased.

The resistor in the present invention is a thin film or a thick film resistor, and the resistance of such a film resistor is shown in Fig. 6A as shown in Fig. 6A. ρ (Ω-cm)], the film thickness (t), the film length (l) and the film width (W). In the resistive film formed on the same chip, it is common to keep p and t constant, and change l and W to obtain a desired resistance value. In this case, as shown in Fig. 6b, the fixed-terminal membrane has a large value of l and a small value of w, but W has a minimum limit according to the miniaturization technique, and it is necessary to increase l in order to form a higher high resistance film. The area occupied by the resistive film is increased. To form a low resistance film, as shown in FIG. 6C, l is made small and W is made large, but l has a minimum limit according to the miniaturization technique as described above, and it is necessary to make W large in order to form a lower resistance film. However, doing so increases the occupied area of the resist film formation. Therefore, the shape and dimension of the membrane resistor are determined in consideration of various conditions such as design, manufacture, and the like.

The trimming resistance network according to the present invention can increase the degree of freedom in selecting resistance values of the constituent resistors for obtaining the desired resistance value change as described in the above embodiments, thereby making it possible to reduce the area required for forming the network.

The parallel trimming resistor in the above embodiment is cut by laser light irradiation using a polysilicon film doped with impurities. Therefore, as compared with cutting metal of high thermal conductivity such as Al in the related art, damage to the underlying layer at the time of laser beam cutting is significantly reduced. Such an effect can be obtained by using any of a nickel-chromium alloy film, a tantalum metal film, a polyimide organic film, an acrylonitrile organic film, or a ruthenium oxide film having a lower thermal conductivity than metals such as Al. There is a number.

[Effect of design]

As described above, in the trimming resistance network according to the present invention, as the trimming resistance main body, a resistive film having a lower thermal conductivity than Al, such as Al, that is, a polysilicon film or a nickel-chromium alloy film doped with impurities is used. Therefore, the laser trimming can be performed without breaking the lower layer portion at the time of cutting the trimming resistor.

In addition, even if a small crack, for example, occurs at the broken portion, current does not flow to the broken portion after cutting, so that the defect that the resistance value changes with time due to the small crack is also eliminated.

In addition, by using the circuit network of the present invention, it is possible to maintain a desired constant change in resistance change during trimming, and thus it is possible to easily realize the precision required for adjusting the output characteristics of the integrated circuit.

In addition, according to the network of the present invention, since the degree of freedom in selecting the resistance value of the constituent resistor for obtaining the desired effect is large, it is possible to reduce the footprint required for forming the network.

Claims (5)

A first connecting body 13 having a plurality of first series resistors 12 having a resistance value r ₂ connected in series, and a first external connection terminal T ₁ provided at one end of the first connecting body 13. One end thereof is connected to the other end of the first connector 13, and includes a first resistor 11 having a resistance value r ₁ , an interconnection point of the first series resistor 12, and the first resistor 11. A plurality of parallel trimming resistors 15 connected between the other ends of the second electrode) and between the one end of the first connector 13 and the other end of the first resistor 11, each having a resistance value r ₃ , and the A second external connection terminal T ₂ provided at the other end of the first resistor 11 is provided, and {(r ₁ + r) between the resistance value r ₁ , resistance value r ₂ , and resistance value r ₃ . ₂ ) · r ₃ } / (r ₁ + r ₂ + r ₃ ) = r ₁ The relationship between the trimming resistance network. 2. A polysilicon film in which the parallel trimming resistor 15 is doped with impurities, a nickel-chromium alloy film, a tantalum metal film, a polyamide organic film, an acrylonitrile organic film or a ruthenium-based film according to claim 1 Trimming resistance network, characterized in that composed of any one of the oxide film. The trimming according to claim 1, further comprising a second resistor (18) having a resistance value (r ₄ ) between said one end of said first connector (13) and said first external connection terminal (T ₁ ). Resistance network. The parallel trimming resistor group (58 _m , 58 _n ) according to claim 1, wherein each of said parallel trimming resistors has a plurality of resistors (R ₃₁ to R _3m , R ₃₁ to R _3n , and R ₃₁ to R _3q ) connected in parallel. , 58 _q ) trimming resistor network. A first connector 13 having a plurality of first series resistors 12a having a resistance value r2a connected in series, a first external connection terminal T ₁ provided at one end of the first connector 13, A second connector 14 having a plurality of second series resistors 12b having a resistance value r _2b connected in series, a second external connection terminal T ₂ provided at one end of the second connector 14, The first resistor 11 and the two series resistors 12a and 12b having a resistance value r ₁ connected between the other end of the first connector 13 and the other end of the second connector 14. A plurality of parallel trimming resistors connected between corresponding interconnect points and between the one end of the first connector 13 and the one end of the second connector 14 and each having a resistance value r ₃ ( 15) and between {(r ₁ + r _2a + r _2b ) · r ₃ } / (r ₁ ) between the resistance value r ₁ , resistance value r _2a , resistance value r _2b and resistance value r ₃ . _2a + _2b + r r r + ₃₎ = r characterized in that the relationship is satisfied ₁ Trimming resistor network.