JPH03211803A - Flat coil - Google Patents

Abstract

PURPOSE:To facilitate the increase or decrease adjustment of inductance and realize miniaturization, by trimming a main coil pattern forming part in the manner in which the terminal end side of a main coil pattern part is extended, and trimming an auxiliary coil pattern forming region together with a substrate, along a gap between adjacent turn parts of the main coil pattern part. CONSTITUTION:By trimming a main coil pattern forming part 22 in the manner in which the terminal end side of a main coil pattern part is extended, an inductance value is increased. By trimming an auxiliary pattern forming part 24 together with a substrate 21, along a gap 38 between adjacent turn parts 37a, 37b of the main coil pattern parts, an auxiliary coil pattern part 25 whose winding direction is inverse to the main coil pattern part is formed, and the inductance value is decreased. As the result, the size of a planar coil 20 is reduced to about one-half as compared with the conventional ones, and the adjustment of inductance can be performed with high sensitivity. Thereby a small sized coil whose increase or decrease adjustment of inductance is easy can be obtained.

Description

[Detailed Description of the Invention] (II required) With regard to high-frequency planar coils used in communication devices, etc., the main coil is installed in the center of the top surface of the substrate for the purpose of making it easy to adjust the increase or decrease of inductance and making it possible to reduce the size. There is a main coil pattern part formed in a spiral shape around the area where the pattern is to be formed, with the starting end on the peripheral edge side of the substrate and the end on the side where the main coil pattern is expected to be formed. , an auxiliary coil pattern formation area larger than the above-mentioned main coil pattern formation area is electrically connected to the main coil pattern formation area and the auxiliary coil pattern formation area below F on the board. A connecting conductor is provided, and the inductance value is increased by trimming the main coil pattern forming portion so that the terminal end side of the main coil pattern portion is extended, and the inductance value is increased by trimming the main coil pattern formation planned portion so that the terminal end side of the main coil pattern portion is extended, and the inductance value is increased. By trimming the portion where the auxiliary coil is to be formed along the knee of the substrate,
An auxiliary coil pattern portion having a winding direction opposite to that of the main coil pattern portion is formed to reduce the inductance value.

[Industrial application field]

The present invention is directed to a high-frequency flat panel used in communication devices and the like.

Planar coils used in communication devices, etc. can be mounted at a lower height than wire-wound coils.
Further, by obtaining a predetermined number of turns by laser trimming, it is possible to obtain an arbitrary inductance value.

In this planar coil, it is desired that the inductance value can be easily adjusted to increase or decrease.

In addition, high-density packaging is progressing in communication equipment, etc.
It is desirable that the planar coil itself is small in plan view.

[Conventional technology]

FIG. 9 shows a planar coil 1 previously filed by the present applicant in Japanese Patent Application No. 1-249669.

This planar coil 1 has a structure in which a main coil part 3 and 4j4 auxiliary coil parts 4 are provided on a rectangular substrate 2.

The main coil portion 3 includes a main coil pattern portion 3a that is thinly wound in a clockwise direction from the terminal 5 at the outer circumferential end toward the inner circumference, and a main coil pattern forming portion 3b in the center.

The auxiliary coil section 4 includes an auxiliary coil pattern forming section 4b in the center, and an auxiliary coil pattern section 4b spirally wound in a clockwise direction from there toward an end F6 of the outer periphery.

The main and auxiliary coil pattern forming portions 3b and 4b are formed by through holes 8. Conductor pattern 9. A through hole 10 provides electrical connection.

Current flows through the main and auxiliary coil sections 3.4 as shown at 1.

The direction of the magnetic flux of the magnetic field generated by the current 1 flowing through the main coil pattern portion 3a is the direction indicated by reference numeral 11 in FIG. 9(C).

The direction of the magnetic flux of the magnetic field generated by the current 1 flowing through the main coil pattern portion 4a is the direction indicated by reference numeral 12.

The magnetic flux 12 acts in a direction that cancels out the magnetic flux 11.

The overall inductance value of this planar coil 1 is shown in the following equation (2). In addition, in this embodiment, the main coil pattern section 3
It is assumed that the number of turns of a is greater than the number of turns of the main coil pattern portion 4a.

L=k (TI - T2)... ■Where, TI: number of turns of main coil pattern section 3b, T2: number of turns of auxiliary coil pattern section 4a, k: coefficient.

From formula (2), it is possible to increase the overall inductance value of the planar coil 1 by increasing the number of turns of the main coil pattern section 3b, and that by increasing the number of turns of the auxiliary coil pattern section 4a, the inductance of the planar coil 1 can be increased. It can be seen that the overall inductance value of can be conversely reduced.

When it is necessary to variably adjust the inductance value of the planar coil 1 in a state where the planar coil 1 is mounted on a communication HM or the like, the variable adjustment is performed as follows.

If the inductance value is insufficient and it is desired to increase it, perform appropriate laser trimming as indicated by reference numeral 15 on the main coil pattern forming portion 3b in FIG. 9(A), and The number of turns of the pattern portion 3a is increased.

For example, when the number of turns of the main coil pattern portion 3a is increased by Δ1, the amount of change ΔL in the inductance value [-] of the entire planar coil 1 is shown in the following equation 0.

From +△L=k((T+ +△Tl)T2), 8L
= k△T1 . . .■ In other words, the overall inductance value of the planar coil 1 increases by 8T1 to 15.

If the inductance value is too large or the inductance value has become too large due to the above adjustment and cannot be reduced, in FIG. As shown, a suitable amount of laser 1 to rimming is performed to increase the number of turns of the auxiliary pattern section 4a.

For example, when the number of turns of the auxiliary coil pattern portion 4a is increased by ΔT2, the amount of change Δ[
' is shown in the following equation 0.

1-10heshi' =k (T+ -(T2 +△T2
)〉, △L' = ∆T2 . . .■ In other words, the inductance of the entire plane 1 (C decreases by 2).

[Problem to be solved by the invention]

Since the main and auxiliary coils 3 and 4 are arranged in parallel, the board 2 has a rectangular shape, and the planar coil 1 has a large size, so that the area required for mounting on the printed circuit board is large.

Furthermore, as can be seen from FIGS. 9A and 9B, the main coil section 3 and the auxiliary coil section 4 face each other only at the - side of their respective rectangular coil patterns, so that they work effectively. The magnetic field generated is limited to the magnetic field generated in the 90° portion of the magnetic field generated around the entire 360° circumference of each coil portion.

Therefore, the amount of change in the inductance value of the planar coil 1 with respect to the increased number of turns of the main coil pattern section 3a and the auxiliary coil pattern section 4a is small, that is, the sensitivity is low, and the value of the above coefficient is small.

For this reason, the length of the laser trimming 15, 16 required to change the overall inductance of the planar coil 1 by a unit amount increases accordingly, and adjustment of increase/decrease in the inductance value becomes troublesome.

An object of the present invention is to provide a planar coil whose inductance can be easily adjusted to increase or decrease its inductance and which is smaller in size.

[Means to solve the problem]

FIG. 1 shows the original striking configuration of a flat surface 20 of the present invention.

21 is a substrate.

Reference numeral 22 denotes a main coil pattern forming portion, which is formed at the center of the upper surface 21a of the substrate 21.

23 is a main coil pattern, which is formed in a spiral shape around the main coil pattern formation area 22 on the upper surface 21a of the substrate 21, as shown by the hatching.

24 is a portion where an auxiliary coil pattern is to be formed;
It is formed at the center of the lower surface 21b. The auxiliary coil pattern forming portion 24 is larger in size than the main coil pattern forming portion 22, and the surrounding portion extends to a portion facing the main coil pattern portion 23. 22A shows the outline of the coil pattern formation planned portion 22 copied onto the auxiliary coil pattern formation planned portion 24.

Reference numeral 25 denotes an auxiliary coil pattern, which is partially formed on the lower surface 21b of the substrate 21, as shown with cross hatching.

A conductor 26 is formed on the substrate 21 and electrically connects the main coil pattern forming portion 22 and the auxiliary coil pattern forming portion 24.

If the number of turns of the main coil pattern section 23 is T+, and the number of turns of the auxiliary coil pattern section 24 is T2, then the number of turns is 2).

27 and 28 are terminals, through which electricity ii flows, for example, as shown by arrows. Hereinafter, the winding direction of the coil pattern section will be along the direction of current flow.

The main coil pattern section 23 includes terminals 27 on the periphery of the substrate 21.
is the starting end 29, the winding direction is clockwise, and the main coil pattern formation planned portion 22 is the ending end 30.

In the auxiliary coil pattern section 25, the auxiliary coil pattern formation planned section 24 is the beginning @i31, the winding direction is opposite to that of the main coil pattern section 23 and is in the opposite direction t1, and the terminal 28 is the terminal end 32.

When the main coil pattern forming portion 22 is trimmed as shown by reference numerals 34 and 35, the main coil pattern portion 23
The number of turns increases, and the inductance of the plane coil 20 increases.

The main coil pattern forming portion 22 is trimmed at t.
Avoid applying the rimming force as shown by arrow 34, and
Move it as shown.

Due to this rimming, the number of turns of the main coil pattern portion 23 increases, and the inductance (direction) of the planar coil 20 increases.

To trim the auxiliary coil pattern forming portion 24, as shown in FIG.
1, adjacent turn portions 37a of the main coil pattern portion 23 from the upper surface 2Ia side.

37b, and move it along the knee gap 38 as shown by an arrow 39.

As shown in FIG. 2(B), the turn portion 37a.

The substrate 21 between 37b and 37b is trimmed, and the auxiliary coil pattern formation area 24 is trimmed.
The auxiliary coil pattern portion 25 is removed as shown by 0, or the number of turns thereof is increased.

The direction of the current flowing through the auxiliary coil pattern section 25 is opposite to the direction of the current flowing through the main coil pattern section 23,
The magnetic flux of the magnetic field generated by the current flowing through the auxiliary coil pattern section 25 acts to cancel out the magnetic flux of the magnetic field generated due to the current flowing through the main coil pattern section 23 .

Therefore, by forming the auxiliary coil pattern section 25 or increasing the number of turns thereof, the inductance value of the planar coil 20 can be reduced.

(Function) The auxiliary coil pattern section 25 is formed on the inner peripheral side of the main coil pattern section 24 concentrically therewith. In addition, the main coil pattern forming portion 22 and the auxiliary coil pattern forming portion 24 are substantially aligned in plan view, and there is no need to provide a space just for arranging the auxiliary coil pattern forming portion 24. Historically, as shown in FIG.
There is no need for any space on the plan view for forming the main coil pattern section 23, and there is no need to widen the pitch of the main coil pattern section 23.

As a result, the planar coil 20 is approximately half the size of the conventional one, making it more compact.

In addition, the main coil pattern section 23 and the auxiliary coil pattern section 24 are arranged concentrically, and are magnetically coupled over the entire 360 degrees of the circumference, not just a part of the circumference. The amount of change in the inductance value of the planar coil 20 with respect to an increase in the number of turns of the section 23 and the auxiliary coil pattern section 25 becomes larger than that of the conventional case, and the above-mentioned coefficient becomes larger than that of the conventional case.

Thereby, the inductance of the planar coil 20 can be adjusted with sensitivity, and the inductance can be adjusted easily.

Additionally, trimming to adjust the inductance can be performed at approximately the same location, and the direction of trimming that increases inductance and the direction of trimming that decreases inductance are the same, which also makes it easy to adjust the inductance. Become.

〔Example〕

3 and 4 show a planar coil 40 according to an embodiment of the present invention.

41 and 42 are both ceramic substrates, each having a substantially square shape.

On the upper surface 41a of the substrate 41, a rectangular main coil pattern formation portion 43. A rectangular spiral main coil pattern portion 44 is formed around this.

As shown in FIGS. 4 and 5, the upper surface 4 of another substrate 42
A rectangular auxiliary coil pattern forming portion 4 is formed in the center of 2a.
5 is formed. 46 is an auxiliary coil pattern portion, which is partially formed.

If the number of turns of the main coil pattern part 2 440 is T+, and the number of turns of the auxiliary coil pattern part 46 is T2, then the number of turns of the main coil pattern part 2 is T2.

Mainly, the number of turns of the main fill pattern portion 44 is the planar coil 40.
determine the inductance value of the auxiliary coil pattern section 4.
The number of turns of 6 adjusts the inductance value of the planar coil 40.

The substrates 41 and 42 are stacked as shown in FIG.
The main coil pattern formation planned Fi 43 and the main coil pattern section 44 are arranged on the upper surface 41a side of the substrate 41, and the auxiliary coil pattern formation planned section 45 and the auxiliary coil pattern section 46 are also arranged on the lower surface 4, 1b side of the substrate 41. .

Terminals 47 and 48 are fixed at the center of both sides of the planar coil 400, respectively.

A hole in the center of the substrate 41 is filled with solder 49 to electrically connect the coil pattern forming portions 43 and 45.

For example, the current i flows as shown by the arrow. That is, terminal 4
7→Main coil pattern section 44→Main coil pattern formation section 43→Solder 49-→Auxiliary coil pattern formation section 45→Auxiliary coil pattern section 46→Through hole 50 on board 41→Wiring pattern 51 on board 41 →The order is terminal 48. The winding direction of the coil pattern portion is along the direction of the current.

The main coil pattern 44 has a starting end 52 on the peripheral edge side of the substrate 41.
It is connected to the terminal 47, the winding direction is clockwise, and the peripheral edge of the coil pattern formation planned portion 43 is the terminal end 53.

The auxiliary coil pattern section 46 has a starting end 54 at the planned coil pattern formation site 145, a winding direction opposite to that of the main coil pattern 44, and a terminal end 55 at the position of the through hole 50. .

Main coil pattern section 44 and auxiliary coil pattern PI14
6 is concentric with the main coil pattern formation planned portion 43 as the center.

When the outline of the main coil pattern formation area 43 is drawn on the auxiliary coil pattern formation area 45, it becomes as shown by the center mark @43A in FIG. 5. That is, the auxiliary coil pattern formation area 45 is the main coil pattern formation area It is one size larger than 43, and the surrounding portion faces the coil pattern portion 44.

56 is a rectangular yoke member made of magnetic material, and is connected to the substrate 4.
It is fixed to the bottom surface of 2.

The above-described planar coil 40 is mounted on a printed circuit board (not shown) of a communication device using terminals 47 and 48.

The size of the planar coil 40 in a plan view is the same size as the substantially rectangular substrate 41, and is smaller than the conventional coil, and can be mounted with higher density than the conventional coil.

Adjust the inductance as necessary while it is mounted.

In order to increase the inductance value between the terminals 47 and 48 of the planar coil 40, laser trimming is performed on the main coil pattern formation area 43, as shown by reference number 60 in FIG.

As a result, a coil pattern having the same winding direction as the main coil pattern section 44 is formed to extend toward the terminal end side of the main coil pattern section 44, as shown in FIG. 440 The number of turns increases, and the inductance value of the planar coil 40 increases according to the above equation 0.

The laser trimming at this time is performed by setting the laser intensity to a level that does not trim the ceramic substrate 41.

Conversely, in order to reduce the inductance value of the planar coil 40, the adjacent turn portions 64a of the main coil pattern portion 44, as shown by the symbol @63 in the diagram a'13.

The substrate 41 and the auxiliary coil pattern section 46 on the lower surface side thereof are trimmed along the knee gap 65 between the sections 64b and 64b, and trimming is performed using the laser 1 with a laser of sufficient strength.

As a result, as shown in FIG. 8, the board 41
and the auxiliary coil pattern section 46 are removed, and the coil pattern in the winding direction is the same as the auxiliary coil pattern section 46, as shown in notice number 67 in Figure 7. It is formed to extend toward the starting end 54 side, the number of turns of the auxiliary coil pattern section 46 increases, and the inductance value of the planar coil 40 decreases according to the above equation 0.

The main coil pattern section 44 and the auxiliary coil pattern section 46 are arranged concentrically, and as shown in FIG. ) and the magnetic field (reference numeral 71 indicates magnetic flux) generated by the current i flowing through the auxiliary coil pattern section 46.
, which interacts with phase U, and the coefficients in the above equation are more numerous than in the past.

As a result, the ratio of change in the inductance value of the planar coil 40 to the extended length of the coil pattern becomes large.

Therefore, the inductance value can be adjusted by a desired amount by reducing the length of laser trimming.

Further, the direction of laser trimming for increasing and decreasing the inductance value is both in the same direction as the temporal direction. From this point of view as well, laser trimming becomes easy.

Further, as can be seen from the method of forming the extended coil pattern 67 of the auxiliary coil pattern section 46 and from FIG. It is formed along the pattern section 44.

Therefore, there is no need for a space in the plan view for arranging the auxiliary coil pattern section 46 (coil pattern section 67), and there is no need to widen the pitch of the main coil pattern section 44.

As a result, the planar coil 40 becomes approximately 1/2 the size of the conventional coil.

〔Effect of the invention〕

As explained above, according to the present invention, since the auxiliary coil pattern section is formed directly below the main coil pattern section, the auxiliary coil pattern section can be used as the f1 main coil pattern section if the size of the board is to be increased. The size can be reduced to about 1/2 compared to the conventional method in which the coil pattern section and the auxiliary coil pattern section are arranged side by side, and the process is easy for high-density mounting.

In addition, the magnetic coupling of the main auxiliary coil pattern is
Since it is obtained over 60 degrees, the ν1 sum of the change in inductance value due to laser trimming is large, the length of trimming to adjust the desired amount of inductance is short, and the inductance can be easily adjusted to increase or decrease. I can do it.

Furthermore, the trimming direction for increasing or decreasing the inductance is the same direction, and in this point, the adjustment for increasing or decreasing the six inductances can be easily performed.

[Brief explanation of drawings]

Fig. 1 is a diagram showing the basic configuration of the present invention, Fig. 2 is a cross-sectional view taken along the line If-II in Fig. 1, explaining trimming of a portion where an auxiliary coil pattern is to be formed, and Fig. 3 is an illustration of an embodiment of the present invention. A plan view of the planar coil, Fig. 4 is a cross-sectional view taken along line IV-IV in Fig. 3, Fig. 5 is a smaller view of Fig. 3 with the upper layer substrate removed, and Fig. 6 shows the inductance value. Figure 7 is a plan view of the auxiliary coil pattern after trimming to increase the inductance value, Figure 8 is a diagram showing the auxiliary coil pattern section after trimming to decrease the inductance value, and Figure 8 is the state after trimming to decrease the inductance value, as well as the main coil pattern section and the auxiliary coil pattern. FIG. 9 is a diagram showing a planar coil previously filed by the present applicant. In the figure, 20.40 is a planar coil, 21.41.42 is a substrate, 21a and 41a are upper surfaces, 21b and 41b are lower surfaces, 22.48 is a main coil pattern formation area, and 23.44
24.45 is the main coil pattern area, 24.45 is the auxiliary coil pattern formation area, 25.4
6 is the auxiliary coil pattern part, 26 is the conductor, 27.28.47.48 is the end f, 29.31, 52.54 is the starting end, 37a, 37b, 64a, 64b is the turn part, 38.6
5 is between the knees, 30.32.53.55 is the end, 35.39 is the trimming direction, 49 is ¥ [l, 57 is the yoke member, 60.63 is the direction of ray + f1 - rimming, 61.67
66 and 100 are portions invaginated by trimming, and 70 and 71 are magnetic fluxes. λQ' Association Deposit) An, - Middle 9 Principles of Interest 11 Be Diagram! Figure (A) (8) Figure 2 $3Tfj,'P kJ@4 paddy*ヱλτ云t, -c
#T5 5th Figure A>Ducter>Wait for the trimming to make the booster port open.

Claims (1)

[Scope of Claims] A main coil pattern formation planned portion (22, 43) is provided at the center of the upper surface (21a, 41a) of the substrate (21, 41), and around this, a starting end (29, 52) on the peripheral edge side of the substrate, The main coil pattern portion (23
, 44), and an auxiliary coil pattern formation area (24, 45) larger than the main coil pattern formation area (23, 44) is provided at the center of the lower surface (21b, 41b) of the substrate (21, 41). and a conductor (26, 49) is provided on the substrate to electrically connect the upper and lower main coil pattern formation areas and the auxiliary coil pattern formation areas, and the main coil pattern formation area (22) , 43) is trimmed so that the terminal end side of the main coil pattern section is extended to increase the inductance value, and the inductance value is increased by trimming the main coil pattern section so that the terminal end side of the main coil pattern section is extended. (
38, 65), the auxiliary coil pattern formation portion (24, 45) is trimmed together with the substrate (21, 41), thereby forming an auxiliary coil pattern whose winding direction is opposite to that of the main coil pattern portion. Coil pattern part (25, 4
6) is formed to reduce the inductance value.