JPH1098310A - High-frequency line - Google Patents

Abstract

PROBLEM TO BE SOLVED: To flexibly adapt to high density mounting, while maintaining desired characteristic, concerning a high-frequency line formed as a pattern at a circuit board. SOLUTION: This high-frequency line is provided with a circuit board 11 with plural layers, two line patterns 121 , 122 formed on the circuit board 11 as an element constituting an unbalanced circuit, a common pattern 13 formed at a position, opposite to a common direction with respect to a layer where a line pattern is formed and forming a driving power-supplying circuit to the unbalanced circuit and a shielding pattern 14 formed at an inner layer between the layer where the line pattern is formed and a layer where the common pattern is formed. The shielding pattern is formed at a position apart from the line pattern by a distance shorter than clearances between them and is connected with the common pattern.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-frequency line formed on a circuit board as a pattern and having a desired impedance for a high-frequency signal.

[0002]

2. Description of the Related Art A high-frequency line formed as a pattern on a circuit board has a small variation in characteristics and is realized at low cost, and has high compatibility with a semiconductor element on a mounting surface. It is widely used for card-type units for realizing wireless LANs and portable terminals of mobile communication systems.

FIG. 6 is a diagram showing a configuration example of a conventional high-frequency line. 6, printed circuit board 61 has two outer layers (pattern surface), and two strip lines 62 _1, 62 ₂ on one of these outer layers, disposed on these stripline 62 _1, 62 ₂ of the gap Shielding pattern 6
3 are formed. In addition, a common ground pattern 64 is formed in all regions of the other outer layer of the printed board 61,
The common ground pattern 64 and the above-described shielding pattern 63
Is connected through a through hole 65.

In such a conventional example, the strip line 6
2 _1, 62 since _second alternating magnetic field to which a high-frequency signal is formed at the periphery of these strip lines 62 _1, 62 ₂ when applied is blocked by the shielding pattern 63, they strip line 62 _1, 62 ₂ between Electromagnetic coupling becomes coarse, and spurious and unnecessary oscillations generated in both are suppressed.

As a prior art similar to the present invention, there is one disclosed in Japanese Patent Application Laid-Open No. 4-326601.
However, this prior art includes a ground line corresponding to the shielding pattern 63 described above, and a strip line 62 ₁ ,
62 and the amplifier output circuit corresponding to ₂ is formed on a semiconductor substrate together, and in that the interlayer insulating film between them is formed, the present application provides the unique effects described below under the technology related to multi-layer circuit board The invention differs in both the application field and the configuration.

[0006]

By the way, the above-mentioned subordinate
In the conventional example, the strip line 62₁, 62_TwoAnd shielding putter
Are formed on a common outer layer.
Lip line 62₁, 62 _TwoThe distance between the through holes 65
Is set to be larger than the width of the shielding pattern 63 to which it is connected.
I had no choice. Moreover, for high-density mounting of circuit boards
As a result, such an interval forms the blocking pattern 63.
If it is set to the minimum value required for
Lip line 62₁, 62_TwoBetween the shield pattern 63
The value of the stray capacitance created increases these strip lines
Road 62₁, 62_TwoThe impedance of the
Desired characteristics for high-frequency signals described above are not secured
Was.

In order to solve these problems, if the diameter of the through hole 65 is set small, the impedance of the through hole 65 increases and the grounding of the shielding pattern 67 becomes incomplete. , the strip line 62 _1, 62 electromagnetic coupling degree between ₂ increases,
Similarly, the desired characteristics were not secured. Further, regarding the impedance of the through hole 65, the printed board 6
Becomes about one of small thickness low, in this case, the common ground pattern 64 and the strip line 62 _1, 62 of these to the distance between the ₂ decreases stripline 62
_1, 62 ₂ of the impedance is lowered.

Accordingly, in the conventional example, not possible to maintain the impedance and packing density while the coarse electromagnetic coupling generated between the stripline 62 _1, 62 ₂ both due to the above-described configuration to the desired value Was. SUMMARY OF THE INVENTION An object of the present invention is to provide a high-frequency line that can flexibly be adapted to high-density mounting while maintaining desired characteristics for high-frequency signals with a simple configuration.

[0009]

FIG. 1 is a diagram showing the configuration of the invention according to the first and second aspects. The first aspect of the present invention provides a circuit board 11 having a plurality of layers and two line patterns 12 ₁ and 12 ₂ formed on different layers or a common layer of the circuit board 11 as elements constituting an unbalanced circuit.
And a common pattern 13 formed at a position facing a layer in which the line patterns 12 ₁ and 12 ₂ are formed in a common direction and forming a drive power supply path to the unbalanced circuit, among the plurality of layers. , Of a plurality of layers, line pattern 1
2 _1, 12 ₂ and one of the layers of different layers which are formed individually, the different layers or the line pattern 1
A shielding pattern formed on one of an inner layer sandwiched between a common layer on which both 2 ₁ and 12 ₂ are formed, and an inner layer on which a common pattern 13 is formed;
4 is characterized in that the distance between the line pattern 12 _1, 12 ₂ are formed on these line patterns 12 _1, 12 ₂ of the gap below a position, and connected to the common pattern 13.

According to a second aspect of the present invention, in the high-frequency line according to the first aspect, the shielding pattern is connected to the common pattern via a through hole. According to a third aspect of the present invention, in the high-frequency line according to the first aspect, the shielding pattern is a pattern formed between a layer on which the common pattern 13 is formed and a layer on which the shielding pattern is formed. It is characterized in that it is connected to the common pattern 13 via the common pattern 31.

In the high-frequency line according to the first aspect of the present invention, the circuit board 11 is used as an element constituting an unbalanced circuit.
When a high frequency signal is applied to the line pattern 12 _1, 12 ₂ formed, their line patterns 12 _1, 12 ₂
In general, an alternating magnetic field is generated around. However, the shielding pattern 14 is connected to the common pattern 13 which is a driving power supply path for the unbalanced circuit and is regarded as a ground point for the above-described high-frequency signal, and
_1, 12 ₂ line pattern 12 ₁ distance of these and, 1
Since it is formed at a position which is a 2 _second gap below it is prevented that span line pattern alternating magnetic field described above is opposed. Therefore, the electromagnetic coupling between the line patterns is suppressed irrespective of the width of the gap between the line patterns 12 ₁ and 12 ₂ .

In the high-frequency line according to the second aspect of the present invention, the width of the pattern forming the shielding pattern 14 is:
The value is set to be larger than the minimum value to be ensured for forming the through hole 21 between the shielding pattern 14 and the common pattern 13. However, the shielding pattern 14
The distance from the line patterns 12 ₁ and 12 ₂ is the same as that of the high-frequency line according to the first embodiment.
_1, 12 ₂ so formed in the gap below a position, the constraints are relaxed according to the shape and dimensions of the gap.

Therefore, by using the through-hole 21 commonly used for connection between different layers, the line pattern 12 ₁ ,
12 electromagnetic coupling between the _two is reliably suppressed. Claim 3
In the high-frequency line according to the invention described in (1), the shielding pattern 14 and the common pattern 13 are different from the invention according to claim 2 in that they are connected via a pattern instead of the through hole 42. Since they are formed at the same positions as the high-frequency lines according to the inventions described in the _first and _second aspects, the electromagnetic coupling between the line patterns 12 ₁ and 12 ₂ is similarly suppressed.

[0014]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG.
FIG. 3 is a diagram showing an embodiment corresponding to the invention described in FIG. In the figure, components having the same functions and configurations as those of the conventional example shown in FIG. 6 are denoted by the same reference numerals, and description thereof is omitted here.

The difference between this embodiment and the conventional example shown in FIG. 6 is that a multilayer board 41 having one inner layer in addition to two outer layers is applied in place of the printed board 61, and replaces the shielding pattern 63. The point is that a shielding pattern 44 is formed in the inner layer, and a through hole 42 is provided instead of the through hole 65. Note that the correspondence between the present embodiment and the claims 1 and 2, the multilayer substrate 41 corresponds to a circuit board, stripline 62 _1, 62 ₂ corresponds to the line pattern, the common ground pattern 64 is common pattern Correspondingly,
The shielding pattern 44 corresponds to the shielding pattern, and the through hole 42 corresponds to the through hole.

In the embodiment having such a configuration, the shielding pattern 44 is connected to the common ground pattern 64 through the through hole 42 in the same manner as in the conventional example shown in FIG. 6, but the shielding pattern 44 is as described above. Strip line 6
2 _1, 62 common than ₂ are formed outer ground pattern 6
4 is formed on the inner layer. Therefore, the shield pattern 44 is grounded with high accuracy because the length of the through hole 42 is shorter than that of the above-described conventional example and the impedance of the through hole 42 is reduced.

Further, since the shielding pattern 44 is formed on the inner layer as described above, the strip line 62 is not limited unless the pattern arrangement in the inner layer is restricted.
_1, 62 regardless of the _second gap width, shape can be suppressed electromagnetic coupling between these stripline, it may be formed in dimensions and arrangement. Furthermore, the outer layer stripline 62 _1, 62 ₂ are formed, the shielding pattern 44 as described above in the gap of these strip lines 62 _1, 62 ₂ because not disposed, thereby improving the degree of freedom relating to the pattern arrangement and component placement .

Therefore, according to the present embodiment, the area of the outer layer occupied by the shielding pattern 63 in the conventional example is effectively used for high-density mounting flexibly adapted to the number of components, and the strip lines 62 ₁ , 62 electromagnetic coupling in the _second gap is set to coarse or better than the conventional example. FIG. 3 is a diagram showing an embodiment corresponding to the third aspect of the present invention.

The difference between this embodiment and the embodiment corresponding to the first and second aspects of the present invention shown in FIG. 2 is that the shielding pattern 44 and the common ground pattern are provided via a pattern 45 instead of the through hole 42. 64 is connected. As for the correspondence between the present embodiment and claim 3, the pattern 45 corresponds to the pattern.

[0020] In an embodiment of such a configuration, among the multi-layer substrate layer has a strip line 62 _1, 62 grooves should ₂ shielding pattern 44 on the outer layer is not formed is placed, further the outer layer and This is realized by sticking a conductor foil in the groove or engaging a conductor mass as a substitute for the common ground pattern 64 in the groove. Therefore, according to the present embodiment, the area of the outer layer occupied by the shielding pattern 63 in the conventional example can be flexibly adapted to the number of components in the same manner as in the embodiment corresponding to the first and second aspects of the present invention. It is effectively subjected to high-density mounting, and electromagnetic coupling in the gap of the strip line 61 _1, 61 ₂ is set to the coarse or better than the conventional example.

FIG. 4 is a view showing another embodiment of the arrangement of the shielding patterns 44. As shown in FIG. In the embodiment corresponding to the _first and _second aspects of the present invention, the strip lines 62 ₁ and 622 are formed on a common outer layer, and the shielding pattern 44 is formed on an inner layer closest to the outer layer. , if these striplines 62 _1, 62 ₂ are formed separately on the outer and inner layers, FIG. 4 (a), the (b), the shielding pattern 44 in the same layer as one of the strip line or it is formed, further, as shown in FIG. 4 (c), the striplines 62 _1, 62 ₂ may be formed in a layer sandwiched between the formed layer.

Further, in the embodiment corresponding to the third aspect of the present invention, the arrangement of the shielding pattern 44 corresponds to the embodiment corresponding to the first and second aspects of the present invention shown in FIG. Is also applicable. FIG. 5 is a diagram showing a second configuration example of the embodiment according to the third aspect of the present invention.

In an embodiment corresponding to the third aspect of the present invention, when a circuit is formed in an inner layer sandwiched between an inner layer on which the shielding pattern 44 is formed and an outer layer on which the common ground pattern 64 is formed. Is, as shown in FIG.
The hole 5 through which the pattern constituting the circuit passes through the pattern 45
6 may be formed. In each embodiment described above, the strip line 62 _1, 62 ₂ but are both formed in the outer layer, these strip line 62 _1, 62 ₂ both may be formed in a common or different lining.

[0024]

As described above, according to the first to third aspects of the present invention, regardless of the gap between the two lines forming the unbalanced circuit, the electromagnetic coupling between these lines is surely coarse. Is set to Further, in the invention according to claim 2,
The use of through holes commonly used for connection between different layers ensures that the shielding pattern is grounded.

Therefore, in the electronic apparatus to which these inventions are applied, the degree of freedom relating to the arrangement of components and patterns on the circuit board and the characteristics of the line are maintained, and the electronic apparatus is adapted to the shape and electrical characteristics of the circuit board. At the same time, high-density mounting is reliably realized at low cost.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of the invention described in claims 1 and 2;

FIG. 2 is a diagram showing an embodiment corresponding to the first and second aspects of the present invention.

FIG. 3 is a diagram showing an embodiment corresponding to the invention described in claim 3;

FIG. 4 is a view showing another aspect of the arrangement of the shielding patterns 44.

FIG. 5 is a diagram showing a second configuration example of the embodiment corresponding to the invention described in claim 3;

FIG. 6 is a diagram illustrating a configuration example of a conventional high-frequency line.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Circuit board 12 Line pattern 13 Common pattern 14, 44, 63 Cutoff pattern 21, 42, 65 Through hole 45 Pattern 61 Printed board 62 Strip line 64 Common ground pattern

Claims (3)

[Claims] A circuit board having a plurality of layers; two line patterns formed on different layers or a common layer of the circuit board as elements constituting an unbalanced circuit; A common pattern formed at a position facing a layer in which a line pattern is formed in a common direction and forming a supply path of driving power to the unbalanced circuit; and a line pattern of the plurality of layers is individually formed. In any one of the different layers formed on the inner layer sandwiched between the common layer in which the different layers or the line patterns are formed and the layer in which the common pattern is formed. And a shielding pattern formed, wherein the shielding pattern is formed at a position where a distance from the line pattern is equal to or less than a gap between the line patterns, and is connected to the common pattern. High-frequency line, characterized in that. 2. The high-frequency line according to claim 1, wherein the shielding pattern is connected to the common pattern via a through hole. 3. The high-frequency line according to claim 1, wherein the shielding pattern is formed on the common pattern via a pattern formed between a layer on which the common pattern is formed and a layer on which the shielding pattern is formed. A high-frequency line characterized by being connected.