JPS6018936A - Integrated circuit - Google Patents

Abstract

PURPOSE:To operate an integrated circuit normally even when wiring width is reduced by dividing a circuit terminal into a plurality of groups by the voltage- drop tolerance values of wirings to reference voltage and separately mounting the power supply wirings at every group. CONSTITUTION:A circuit terminal 2 having the small voltage-drop tolerance values of wirings on an integrated circuit to voltage as a reference and a large circuit terminal 3 are divided, and power supply wirings 4' and 4'' are each connected to a power supply pad 7. Currents i1 and i2 each flow into the terminal 2 and the terminal 3, and currents i1+i2+i3 flow out at a wiring terminal 5'. Accordingly, voltage drop can be reduced by using the wirings 4' and 4'', and wiring width can be minimized remarkably.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of the Invention] The present invention relates to an integrated circuit with an improved wiring method.

[Prior art]

While recent integrated circuits are becoming more highly integrated,
Performance is being accelerated. This tendency is especially noticeable in bipolar varieties. As a means of speeding up the process,
In addition to improved device performance, there is an increase in circuit current.

However, a normal circuit has circuit terminals that are sensitive to voltage drops and have a small voltage drop tolerance value, and circuit terminals that are insensitive and have a large voltage drop tolerance value. It was connected in the state. Therefore, if the internal circuit current were to increase completely, the voltage drop in the internal wiring would also increase, and in particular, circuits that were sensitive to voltage drops could no longer operate normally.

FIG. 1 is a plan view showing a main part of an example of a conventional integrated circuit.

A circuit terminal 2 having a small voltage drop tolerance value and a circuit terminal 3 having a large voltage drop tolerance value of the circuit 1 are connected from a power supply pad 7 by the same wiring 4.

Now, connect circuit terminal 2 and circuit terminal 3 of circuit 1.
Let us calculate the necessary width of the wiring 4 in the case where one current t, l F flows in and a current (i, +i2+ia) flows through the wiring end 5. However, it is assumed that the circuit terminal 3 and the circuit terminal 2 are on the same straight line. Width of wiring 4 is W
l, the length between the circuit terminal 2 and the wiring end 5 is -e1, and the layer resistance of the cotton distribution is ρ. Furthermore, for circuit terminal 2, l(1, circuit terminal 3
In contrast, let us look at the minimum wiring width necessary to satisfy 2 (0≦, <K 2 ). In this case, naturally, it is sufficient to consider the case where the voltage drop tolerance range value is small. Therefore, the minimum wiring width Wa of the wiring 4 is Wa=
7ed-(i,+i2+j,)=Wi, (1).

That is, the minimum wiring width Wa is limited by the requirements of circuit terminals with small voltage drop tolerance values, and it is necessary to use wiring that is wider than necessary. If the wiring width is smaller than (Wa of type 12), the circuit terminal 20 circuit will not operate normally as described above.

In order to prevent stiffness, conventionally it was necessary to improve the film quality and thickness of the metal conductor used in the wiring, or to increase the wiring width to reduce the voltage drop. However, in the former case, there are limits to current process technology and it is difficult to make significant improvements, and in the latter case, increasing the wiring width is difficult.
There was a problem in that it was a major hindrance to improving the degree of integration.

On the other hand, by arranging a plurality of similar circuits in parallel, a predetermined circuit terminal to which a power supply is connected (for example, circuit terminal 2 in FIG. 1)
If the potential of the signal input to the circuit is equal to the potential of the signal,
There are cases where it is said that the size has a certain slope, but in the conventional technology shown in Figure 1, the circuit terminal 2 and the circuit terminal 3 are not separated. , h cannot be arbitrarily set.

Therefore, there is a problem that the potential of the circuit terminal and the potential of the input signal become unbalanced, causing the circuit to malfunction.

[Purpose of the invention]

An object of the present invention is to solve the problems of the prior art, thereby enabling normal operation of circuits including circuit terminals with small voltage drop tolerance values even if the wiring width is smaller than before. Further, it is an object of the present invention to provide an integrated circuit having a power supply wiring that can fully regulate the potential relationship of a predetermined group of circuit terminals as necessary, and which has an improved degree of integration and stability of circuit operation.

[Structure of the invention]

The integrated circuit of the present invention is constructed by dividing the circuit terminals into a plurality of groups according to the permissible voltage drop range value of the wiring with respect to a reference voltage, and separately providing power supply wiring for each group.

[Example ship, Ming]

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 2 is a plan view showing essential parts of the first embodiment of the present invention. In this embodiment, the present invention is applied to the conventional integrated circuit shown in FIG. 1, and the same components are given the same reference numerals.

In this embodiment, the circuit terminal 2 and the circuit terminal 3, which have a small voltage drop tolerance value of wiring on the circuit with respect to the reference voltage, are separated, and the power supply wirings 4' and 4' are connected individually. It is configured by connecting to the power supply pad 7.

Next, there is a difference between the case of the conventional example shown in FIG.
and 12 flow in, and the current (i, +i2
+i3) has leaked out, and circuit terminal 2 and circuit terminal 3
Length f between wire end 5' and wire end 5': The layer resistance of wires 4' and 4# is ρ8, and the voltage drop tolerance values of circuit terminals 2 and 3 are respectively 1 and K2, and in this case, Let's find the required minimum wiring width wbl.

Minimum wiring width total W 2 to bring the '11i pressure drop of circuit terminal 2 into Kl, times 1t! 8 The voltage drop at terminal 3 is K
Minimum wiring width W 4 and W2 for entering inside z
Assuming that the separation width between and W4 is kW3, the relational expression % (3) is obtained. Therefore, from equations (1) and (2) to equation (3) and K 2 ':;> K t≧0, the separation width W
3 is W 3<W2. Since Wa is set, Wb=(W2+W3+W4)<Wl=Wa...
・・・・・・・・・(6)

Therefore, by using the wires 4' and 4# of this embodiment, the voltage drop can be reduced, and the wire width is smaller than that of the conventional wire 4 in FIG.
It can be made much smaller than.

Next, by giving a numerical example, we will specifically compare the conventional example of the 11th sill with the first embodiment of the present invention shown in FIG.

Based on the above equation, the current i flowing through the circuit terminal 2.

==5mA, current flowing through circuit terminal 3 12 =50mA
Current i3 flowing out from 1 wiring end 6' = 195mA,
The voltage drop tolerance of circuit terminal 2 is 1 = (+)5 A = 4
Assuming layer resistance ρ of 00μm1 wiring, = 0゜02Ω/d,
Find the minimum line widths Wa and wb in each case. However, the separation width W3 is set to 5 μm.

From formula (1), Wb = 400 μm (from formula (2), from formula (3) to formula (6), Wb = 8 + 5 + 19.6 = 32.6 ttm. Therefore, the minimum wiring width of the embodiment of Mizuhiro 1 It can be seen that it can be very small, about 8% or more of that of the conventional example, that is, 1/10 or more -F.

Figure 3<a)r,! A plan view showing the main parts of the second embodiment of the present invention, and FIG. 3(1) is a characteristic diagram thereof.

In this embodiment, N similar circuits 11, 12...
.

The circuit terminals 21 and 2 each have a small voltage drop tolerance range value from the i1 reference point.
2. ......, 2N and large circuit terminals 31°32,
-... 3 Nff: The present invention is applied to the existing circuit, and the wiring 42 is connected to the circuit terminal 21゜2.
Wiring 43 for 2, . . . , 2N and circuit terminals 31, 32 . . . , 3N, and are connected to the power supply pad 41. In addition,
It does not matter if any current flows out from the wiring ends 45 and 46.

The case of this embodiment is similar to the case of the first embodiment shown in FIG.
The required wiring width may be much smaller.

Furthermore, the circuit terminal 21 of the conventional wiring and the wiring 43 of this embodiment
, 22. ......, the voltage drop at the 2N position is the third
As shown in the straight lines a and b' in the figure (bJ), the voltage drop in conventional wiring is large and uneven, as shown in the straight lines a and a' in the same figure. On the other hand, the voltage drop of the wiring 42 in this embodiment is extremely small and has a uniform voltage drop.

That is, according to this embodiment, the width of the conventional wiring can be reduced, and a substantially uniform potential can be applied to predetermined circuit terminals.

FIG. 4(a) is a plan view showing a main part of an embodiment of FG3 of the present invention, and FIGS. 4(11) and 4(C) are characteristic diagrams thereof.

In this embodiment, N similar circuits 51, 52 .・・・・・・
・Contains a circuit group consisting of 5N, Sowara is Sowazowa,
Circuit terminals 61, 62 .with small tolerable tli pressure drop values from the benchmark.・・・・・・6N and large circuit terminal 7
1.72. ......, 7N, and the signals VSI,
VS 2. . . . The present invention is applied to a circuit to which VSN is input, and the wiring 92 is connected to the circuit terminals 61, 62, . . . ., wiring 93 for 6N and circuit terminals 71.7.2. . Note that the wiring 93 is separated from the circuit terminal 6N portion of the wiring 92, the portion 95 overlapping the wiring 92 is the first layer wiring, and the opening 96.97 is connected to the wiring 93 formed by the second layer wiring. has been done.

Furthermore, in the circuit of this embodiment, the signals VSI, VS2, old, and VSN input to the circuit of soh(ji) are as shown in FIG.
As shown in a), the signal VSI to the circuit 51 is gradually increased in accordance with a constant slope, and the signal VSI to the circuit 51 is gradually increased.
1,52. ......, 5N are circuit terminals 6, respectively.
1,62. -..., 6N potential and input signal Vs
1. Vs 2. -, Vs N (If the D potential is the same value for all circuits, the most normal circuit operation is possible.

Here, as shown in the conventional example of FIG. 1, in the case where the wiring is not separated and in the case of this embodiment, when current flows through both ends 95, 96 of the wiring, the circuit terminals 61, 62, .・・・・・・
..., 6N potential is as shown in FIG. 4(C). That is, in the case of this embodiment, the wiring 93 is unified via the wiring 95, and the current passes through the circuit terminal 6N and reaches the power supply pad 9.
1, and the wiring width is set so that the voltage drop per unit length of the wiring becomes the predetermined potential gradient shown in Figure 4(b). C) The straight line in the middle will be as shown in the figure. On the other hand, in the case of conventional wiring that does not completely separate the wiring, as shown in Figure 4 (straight lines a and a' in CJ), the voltage drop decreases as the distance from the power supply pad 91 increases from the center. .

Thus, circuit terminals 61, 62. . . . 6N potential and input signals Vs l, Vs 2. −..., Vs
In a circuit using conventional wiring, the potential difference between N is unbalanced and may cause malfunction, but in this embodiment, it is formed in an extremely well-balanced manner, ensuring stable and normal operation. can do. That is, according to this embodiment, when the terminal potential is required to be at a predetermined level, it can be adjusted to a certain value, which is useful for completely stabilizing the circuit operation.

Note that the above explanation is limited to the case where the voltage drop tolerance range value of the wiring is two types, small terminal and large terminal, but if the voltage drop tolerance value is further divided into several types, Group A, group B, c2; y, ・according to the allowable range value.
...It's no wonder that they can expand like the N group.

〔Effect of the invention〕

As explained in detail above, according to the present invention, circuit terminals are divided into a plurality of groups according to the permissible voltage drop value of the wiring with respect to the reference voltage, and power supply wiring is provided separately for each group, so that the conventional power supply Even if the wiring width is much smaller than the wiring, it is possible to operate normally, including circuits that have circuit terminals with a small voltage drop tolerance, and it is possible to regulate the potential relationships of a given group of circuit terminals as necessary. However, an integrated circuit having power supply wiring can be obtained. Therefore, the integrated circuit of the present invention has the effect of improving the degree of integration and stability of circuit operation.

[Brief explanation of drawings]

FIG. 1 is a plan view showing a main part of an example of a conventional integrated circuit, FIG. 2 is a plan view showing a main part of a first embodiment of the present invention, and FIG.
4(b) and (C) are characteristic diagrams of the wood brush 3 according to the embodiment. 1...Circuit, 2.3...Circuit terminal%
4,4'14' --- Power supply wiring, 5.5', 6.6
'... Wiring end, 7... Power pad, 1
1,12. IN...Circuit, 21, 22.2N,
31, 32.3N...Circuit terminal, 41...
・・Power supply pad, 42, 43.44 ・・・・Power supply wiring, 45.46 ・・・・Wiring end, 51, 52° 5N
・・・・・・Circuit, 61, 62.6N, 71, 72°7
N, 81, 82.8N...Circuit terminal, 91...
...-Power pad, 92, 93, 94.95...-
・・Power wiring, ' 96.97 ・・・Opening, 9
8.99...Wiring end. Agent: Susumu Uchihara, patent attorney. Figure l Figure 2 Figure 3 βq(ρ) Figure 3 (b)

Claims (3)

[Claims] (1) An integrated circuit characterized in that circuit terminals are divided into a plurality of groups according to the permissible voltage drop range value of wiring with respect to a reference voltage, and power supply wiring is individually provided for each group. (2) Claim No. 1 that includes power supply wiring in which the power supply wiring to the circuit terminals of the group with a small voltage drop tolerance is separated from a part of the power supply wiring to the circuit terminals of the group with a large voltage drop tolerance. ] The integrated circuit described in the section. (3) At least one part where the power supply wiring to the circuit terminal of the group with the small voltage drop tolerance is far from the point that serves as the reference voltage of the power supply wiring to the circuit terminal of the group with the large voltage drop tolerance. 2. The integrated circuit according to claim 2, wherein a portion of the power supply wiring, which is separated from the power supply wiring and has a large voltage drop tolerance, is straddled by a multilayer wiring.