JPH0757938A - Spiral inductopr and reactance regulation thereof - Google Patents

Abstract

PURPOSE:To provide a spiral inductor in which the reactance can be regulated easily without causing any trouble in the circuit and a method for regulating the reactance. CONSTITUTION:The spiral inductors 13a, 13b have rectangular spiral main lines 14a, 14b and they are isolated from each other at the intersection thereof by means of air bridges 15a, 15b. The main lines 14a, 14b are connected, at one ends 16a, 16b thereof, through a subline 17. The main lines 14a, 14b are arranged to stride across the subline 17 and reach the other ends 19a, 19b thereof at the initial manufacturing stage through the use of air bridges 18a, 18b being pressed only when the reactance is regulated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spiral inductor and a reactance adjusting method thereof, and more particularly to a spiral inductor formed on a semiconductor substrate to form a monolithic integrated circuit and a reactance adjusting method thereof.

[0002]

2. Description of the Related Art FIG. 4 is a plan view of an example of a conventional spiral inductor, and FIG. 5 is a sectional view taken along the line AA 'of FIG. In both figures, the single spiral inductor 1 is
A main line 3 having a constant width is formed on the semiconductor substrate 2 in a rectangular spiral shape. Here, the portions 4 of the main lines 3 that are orthogonal to each other have an air bridge structure and are not in contact with each other. On the other hand, the air bridge 5 is an air bridge that short-circuits adjacent main line portions.

The spiral inductor 1 constitutes, for example, a microwave band inductance circuit and is mounted on a monolithic integrated circuit. When adjusting the inductance of the spiral inductor 1, the air bridge 5, which has short-circuited the main line portions in the past, is cut (Japanese Utility Model Laid-Open No. 60-52642).

[0004]

However, in the conventional spiral inductor 1 described above, the reactance is adjusted by cutting the air bridge 5.
There is a problem that the cutting direction needs attention and the adjustment cannot be easily performed, and the circuit may be broken or the lower conductor may be damaged due to the fragments generated by the cutting.

The present invention has been made in view of the above points,
An object of the present invention is to provide a spiral inductor capable of easily adjusting reactance and a reactance adjusting method thereof.

[0006]

In order to achieve the above object, the spiral inductor of the present invention has a plurality of spiral inductors each having a main line formed in a spiral shape on a semiconductor substrate by a sub line. This is an air bridge structure that can connect and press the main line portion that straddles the sub line. The method of the present invention is such that the above air bridge is crushed while observing it with a microscope.

[0007]

In the present invention, since the air bridge for adjusting the reactance can be pressed, the air bridge can be crushed without being cut. Further, in the method of the present invention, in a state where a plurality of spiral inductors are connected in series or in parallel, by crushing an arbitrary air bridge, the spiral inductor corresponding to the air bridge can be short-circuited.

[0008]

1 is a plan view of an embodiment of the present invention, and FIG. 2 is a sectional view taken along the line II--II of FIG. In both figures,
The spiral inductor 11 of this embodiment is, for example, GaAs.
Two single spiral inductors 13a and 13b are arranged side by side on a semiconductor substrate 12 made of aluminum. In the spiral inductors 13a and 13b, main lines 14a and 14b, which are conductors having a constant width, are formed in a rectangular spiral shape, and the portions where the main lines 14a and 14b intersect each other are not in contact by the air bridges 15a and 15b. Is being done.

Also, one end 16 of each of the main lines 14a and 14b
The a and 16b are connected to each other by the sub line 17, so that the two spiral inductors 13a and 13b are connected in series. Also, the main line 1
4a and 14b, as shown in FIG.
It is arranged so as to pass over the sub line 17 by a and 18b and reach the other ends 19a and 19b.

The above-mentioned main lines 14a, 14b and sub-line 17
The air bridges 15a, 15b, 18a and 18b are made of gold, for example. The air bridges 18a and 18b can be pressed.

FIG. 3 shows an equivalent circuit of the embodiment shown in FIGS. In FIG. 3, L13a and L13b are inductors composed of single spiral inductors 13a and 13b, respectively, which are connected in series. Further, S18a and S18b denote switches formed by the air bridges 18a and 18b, respectively.

These switches S18a and S18b
Constitutes a switch that short-circuits or non-short-circuits the inductors L13a and L13b, respectively. That is, when the air bridge 18a is not in contact with the sub line 17 as shown in FIG. 2, the spiral inductor 13a has an inductor of a predetermined reactance in which the one end 16a and the other end 19a are connected by the main line 14a. The switch S18a is off because it constitutes L13a.

On the other hand, when the air bridge 18a is crushed and is in contact with the sub line 17, the spiral inductor 13a is directly connected between the one end 16a and the other end 19a to short-circuit the two. Therefore, the main line 1
Inductor L13a having a predetermined reactance connected by 4a
Cannot be configured, and the switch S18a can be represented as ON. The same applies to the other switch S18b.

Next, the reactance adjusting method of this embodiment will be described. When the current reactance is higher than required, the coordinator can use the microscope
While observing 8a or 18b, use a needle with a sharp tip, for example, a sapphire needle to air bridge 18a or 18
b is pressed (crushed) from above toward the semiconductor substrate 12. The pressing itself may be performed manually by an adjuster, or may be performed using a machine.

Then, the crushed air bridge 18a
Or 18b is in contact with the sub line 17 and is between the one end 16a and the other end 19a of the main line 14a, or one end 1 of the main line 14b.
Since 6b and the other end 19b are short-circuited, one of the single spiral inductors 13a and 13b is disabled in the circuit.

That is, to explain using the equivalent circuit of FIG.
When the air bridge 18a is crushed, the switch S18a is turned on and both ends of the inductor L13a are short-circuited, while when the air bridge 18b is crushed, the switch S18b is turned on and the inductor L1 is turned on.
Both ends of 3b are short-circuited. Therefore, the reactance of the entire spiral inductor 11 is adjusted to a value smaller than the initial value by the reactance of the shorted inductor.

In the present embodiment, when adjusting the reactance, the air bridge 18a or 18b is crushed instead of being cut. Therefore, fragments such as cutting chips produced by the cutting do not occur, and therefore the fragments cause The circuit does not break down. Further, since the pressing can be easily performed by cutting and pressing at a fine position, the reactance can be adjusted more easily than in the past.

The present invention is not limited to the above embodiment, and the number of single spiral inductors arranged in parallel may be three or more. In this case, the reactance of each of the single spiral inductors is large. By setting the (inductance) to a small value, the reactance can be adjusted more finely.

Further, the single spiral inductors arranged in parallel are easier to manufacture if they have the same structure, but the number of turns may be different, as a matter of course. Further, the single spiral inductors arranged in parallel may be connected in parallel.

[0020]

As described above, according to the present invention,
By crushing the air bridge without cutting it, it is possible to short-circuit the single spiral inductor corresponding to the air bridge and adjust the reactance of the entire spiral inductor. It is possible to prevent the occurrence of circuit failure and damage to the lower layer conductor due to debris. In addition, the reactance can be adjusted by a simpler pressing than the cutting, so that the reactance can be adjusted more easily than in the past.

[Brief description of drawings]

FIG. 1 is a plan view of an embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II in FIG.

FIG. 3 is an equivalent circuit diagram of the embodiment of FIG.

FIG. 4 is a plan view of a conventional example.

5 is a cross-sectional view taken along the line A-A ′ of FIG.

[Explanation of symbols]

11 spiral inductor 12 semiconductor substrate 13a, 13b single spiral inductor 14a, 14b main line 15a, 15b air bridge 17 secondary line 18a, 18b reactance adjusting air bridge L13a, L13b single spiral inductor S18a, S18b switch by air bridge

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[Procedure amendment]

[Submission date] May 26, 1994

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be amended] Title of invention

[Correction method] Change

[Correction content]

Title: Spiral inductor and reactance adjusting method thereof

Claims (2)

[Claims] 1. An air bridge in which terminals of a plurality of spiral inductors each having a main line formed in a spiral shape on a semiconductor substrate are connected by a sub line, and the main line portion straddling the sub line can be pressed. Spiral inductor characterized by having a structure. 2. The air bridge of a spiral inductor, wherein terminals of a plurality of main lines each formed in a spiral shape are connected by a sub line, and a main line portion straddling the sub lines is configured as an air bridge. A reactance adjusting method for a spiral inductor, characterized in that the reactance is adjusted by crushing while observing with a microscope.