JPS6022814B2 - planar inductor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a spiral planar inductor used in a mixed aC electronic circuit.

In a hybrid high-frequency electronic circuit, the spiral line formed on the dielectric substrate is used as an inductor, and is used as a component such as a resonator, a filter, or a matching circuit.

In such cases, in order to achieve the desired circuit characteristics,
It is often necessary to fine-tune the value of the IJ factor exhibited by the spiral line. FIG. 1 shows a conventional example of a planar inductor having a spiral line. A through hole 3 is provided at the center of the spiral line 2 made on the dielectric substrate 1.
The center of the spiral line is connected to the ground conductor 4 via. The reactance is adjusted by electrically connecting the line gap at the center of the spiral line with a conductor foil 5 for reactance adjustment. In this case, a through hole 3 must be made on the transfer plate. This tends to lead to a decrease in manufacturing yield due to damage to the board due to drilling and uncertainty in the electrical connection of through-holes. The drawback was that it had a large impact. FIG. 2 shows another conventional example.

The spiral line 6 is tightly wound to the center, and the center line end is connected to the outer conductor 8 of the spiral line with a bonding wire 7, and the outer peripheral end of the spiral line 6 is connected to a ground conductor 1 via a conductor foil 9. There is. The reactance is adjusted in the same manner as in FIG. 1 by subsequently adjusting the center line gap using the conductor foil 11 for adjustment. However, this adjustment method has the disadvantage that since the adjustment is made at a location where the high frequency potential is high, it not only changes the length of the spiral line but also causes a change in the stray capacitance between the spiral line 6 and the ground conductor 10. was there. The present invention was made in view of the problems of the conventional planar inductor having a spiral line, and an object of the present invention is to provide a planar inductor that is easy to manufacture and whose reactance value can be easily adjusted.

In a spiral line formed on a dielectric substrate, the present invention provides a ground potential conductor on the outside of the line close to the outer periphery of the line, and electrically connects the ground potential conductor and the outer periphery of the spiral line. The present invention is characterized in that it is possible to adjust the reactance value exhibited by the spiral line at the central end of the spiral line by changing the position.

FIG. 3 shows an embodiment of the present invention.

The line machine at the center of the spiral line 13 consisting of a straight line on the dielectric substrate 12 can obtain the same effect as when a spiral line conductor is provided by the bonding wire 14, and the utilization efficiency of the dielectric substrate surface is also improved. Ru. As explained above, according to the present invention, the following effects can be obtained.

■ There is no need to add processing to the dielectric substrate that affects manufacturing yield, such as through-holes.

(2) Since the reactance adjustment point is located on the high-frequency, low-potential side of the spiral line, circuit characteristics can be adjusted stably and easily.

(2) Since the adjustment point is located on the outer periphery of the spiral line, the density of the electromagnetic field in the vicinity is small, so the effect of movement of the adjustment point on the Q value of the spiral line is small.

[Brief explanation of the drawing]

Figures 1 and 2 are configuration diagrams of a conventional spiral line, Figure 3 is a structural diagram of a spiral line showing an embodiment of the present invention, and Figures 4 and 5.
The figure is a configuration diagram of a spiral diagram showing another embodiment of the present invention. 1, 12, 23...dielectric substrate, 2, 6, 13, 21
...Vircular line, 4,10,19...Ground conductor, 5,11
, 20... Adjustment conductor, 7, 14... Bonding wire, 16... Outer periphery of spiral line, 17, 22... Ground potential conductor, 24... Carrier plate. is connected to the conductor 15 of. Outer periphery 1 of spiral line 13
A conductor 17 is provided adjacent to 6, and is connected to a conductor 19 on the back surface of the concession board 12 via a conductor foil 18. Therefore, the conductor 17 is at ground potential. This spiral line electrically connects the outer periphery of the line 16 and the conductor 17 at ground potential with an adjustment conductor foil 20, and the outer periphery of the spiral line 13 has a low potential at high frequencies and the center has a high potential at high frequencies. The conductor foil 20 used as a potential can be connected to any position where the outer peripheral portion 16 of the spiral line 13 and the ground potential conductor 17 are close to each other using a micro spot welder or the like. Since the adjusting conductor foil 20 is at a low potential in terms of high frequency, the reactance exhibited by the spiral line viewed from the conductor 15 outside the spiral line changes smoothly depending on its subsequent position. FIG. 4 shows another embodiment of the present invention in which a ground potential conductor 22 is provided close to almost the entire outer periphery of a spiral line 21, thereby making it possible to widen the reactance adjustment range. In FIG. 5, a ground potential conductor is not provided on the power transfer substrate 23, and the shape of the carrier plate 24 is changed so that a part of the carrier plate 24 for holding the dielectric substrate 23 is close to the outer periphery of the spiral line. In another embodiment of the present invention that has been manufactured, grounding is performed on the conveyor body board 23.

Claims (1)

[Claims] 1 A line formed in a spiral shape on a dielectric substrate having a ground conductor on one side, and a ground potential conductor provided on the outside of this line close to the outer periphery of the line, and the outer periphery of the spiral line and A planar inductor characterized in that a ground potential conductor is electrically connected and the reactance exhibited by a spiral line is adjusted depending on the connection position.