JP6282944B2 - WIRING BOARD AND HIGH FREQUENCY DEVICE USING THE SAME - Google Patents

Description

  The present invention relates to a high-frequency signal wiring board such as a printed board, a circuit board, or a flexible wiring board that transmits a high-frequency signal.

  One of high frequency wiring boards is a wiring board using a coplanar type high frequency line. In the coplanar wiring board, ground conductors are formed on both sides of a line conductor disposed on the surface.

  FIG. 8 is a plan view showing an example of a wiring board having a conventional coplanar type line (for example, Patent Document 1). On the surface of the wiring substrate 101, a strip-shaped line conductor 102 having a straight portion and a bent portion is provided. In addition, on both sides of the line conductor 102, ground conductors 103 are arranged at predetermined intervals along the line conductor 102 to form a coplanar line. The distance between the line conductor 102 and the ground conductor 103 on both sides is designed to be an equal predetermined distance.

  The coplanar line is formed so that the interval W12 between the line conductor 102 and the ground conductor 103 is wider than the interval W11 in the straight line portion at the bent portion of the line conductor 102. In the coplanar line shown in FIG. 8, the corner of the bent portion of the line conductor 102 is cut off, and the interval W12 between the outer ground conductor 103 is widened.

  In order to successfully propagate a high frequency signal through the coplanar line, the characteristic impedance along the coplanar line is made as constant as possible. In the coplanar line shown in FIG. 8, the distance between the line conductor 102 and the ground conductor 103 is increased at the bent portion so that the capacitance component at the bent portion is reduced. As a result, the characteristic impedance at the bent portion is adjusted to avoid reflection of the high-frequency signal at the bent portion.

JP 2010-109243 A

  As in this example, it is not easy to propagate a high-frequency signal satisfactorily in a bent portion of a high-frequency signal line that needs to be bent. In the bent portion, the electromagnetic field accompanying the high-frequency signal is disturbed, and there is a problem that reflection loss and insertion loss are inevitably caused.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a wiring board that reduces high-frequency loss and the like generated in a bent portion of a high-frequency signal line.

A wiring board according to an aspect of the present invention is a coplanar line including a dielectric substrate, a line conductor formed on the surface of the substrate, and a ground conductor disposed on both sides of the line conductor at intervals. The coplanar line has a curved portion that bends in a curved shape, and on the side opposite to the direction in which the curved portion bends, the interval between the line conductor and the ground conductor is wide, and the curved portion In the same direction as the bending direction, the gap between the line conductor and the grounding conductor is narrowed, and the line conductor is cut away at the curved portion in the direction opposite to the bending direction of the curved portion. together are formed by him, the same direction as the direction of bending of the curved portion is formed by projecting the entire in the curved portion by a certain distance shifted in the direction of bending of the curved portion Iruko The features.

  Moreover, in the said curve part, the said ground conductor of the same direction side as the direction where the said curve part bends may protrude and be formed.

  In the curved portion, the ground conductor on the side opposite to the direction in which the curved portion bends may be cut out.

  A high-frequency device according to one embodiment of the present invention includes the wiring board and a high-frequency semiconductor element connected to the coplanar line of the wiring board.

  According to the wiring board of one aspect of the present invention, the coplanar line is wide on the side opposite to the direction in which the curved portion is bent, and the distance between the line conductor and the ground conductor is widened, on the same direction side as the direction in which the curved portion is bent. Since the distance between the line conductor and the ground conductor is narrowed, the electromagnetic field generated in the curved portion changes, and the reflection loss can be reduced.

  In the above wiring board, when the line conductor is formed by cutting away the side opposite to the direction in which the curved portion is bent, the distance between the line conductor and the ground conductor on the side opposite to the direction in which the curved portion is bent is increased. can do.

  Further, if the line conductor is formed so as to protrude in the same direction as the direction in which the curved portion is bent, the distance between the line conductor and the ground conductor on the same direction side as the direction in which the curved portion is bent may be reduced. it can.

  Further, if the ground conductor on the same direction side as the direction in which the curved portion bends is formed in the curved portion, the distance between the line conductor and the ground conductor can be reduced.

  Further, in the curved portion, when the ground conductor on the side opposite to the direction in which the curved portion is bent is formed by being cut away, the distance between the line conductor and the ground conductor can be widened.

  Since the high-frequency device of one embodiment of the present invention includes the above-described wiring substrate, the high-frequency device can be a high-frequency device with excellent high-frequency performance.

It is a top view which shows an example of embodiment of the wiring board of this invention. It is a top view which shows the other example of embodiment of this invention. It is a top view which shows the further another example of embodiment of this invention. It is a top view which shows the further another example of embodiment of this invention. It is a figure which shows the simulation result of the high frequency reflection loss in one Embodiment of the wiring board of this invention. It is a perspective view which shows an example of embodiment of the high frequency device of this invention. It is a top view which shows the semiconductor package part which concerns on one Embodiment of the high frequency device of FIG. It is a top view which shows the example of the conventional wiring board.

  Hereinafter, a wiring board 10 according to an embodiment of the present invention will be described with reference to the drawings. In addition, all the figures are schematic and may differ from an actual dimensional relationship. Further, in the following description, the terms “upper, lower, left, and right” are merely used for explaining the positional relationship on the drawings, and do not mean the positional relationship in actual use.

  FIG. 1 is a plan view showing a wiring board 10 according to an embodiment of the present invention. In the figure, the conductor portions are hatched for easy understanding. These hatches do not indicate a cross section.

  As shown in FIG. 1, a wiring conductor 10 has a line conductor 2 formed on the surface of a substrate 1 made of a dielectric. Ground conductors 3 are formed on both sides of the line conductor 2 at a predetermined interval. The line conductor 2 and the ground conductors 3 on both sides form a so-called coplanar line. Note that a second ground conductor (not shown) may be formed on the back surface of the portion of the wiring board 10 where the coplanar line is formed, and a so-called grounded coplanar line may be formed.

  The line conductor 2 is arranged to meander, for example, and has a curved portion R that bends in a curved shape. The line conductor 2 has a cutout portion 2a in which the side portion on the opposite side to the direction in which the curve bends is cut out at a constant width in the curved portion R. A typical width of the line conductor 2 is, for example, 0.08 mm, and a width of the notch portion 2a is 0.01 mm. Normally, the distance W1 between the ground conductors 3 on both sides of the line conductor 2 is designed to be uniform. However, the distance W2 between the ground conductor 3 and the line conductor 2 on the opposite side to the direction in which the line conductor 2 bends is thereby wider than the interval W1 of the portion that is not the curved portion R.

  On the other hand, a protruding portion 2b having a shape protruding in a constant width is provided on a side portion on the same side as the direction in which the curve of the line conductor 2 is bent. The protrusion width of a typical protrusion 2b is, for example, 0.01 mm. As a result, the interval W3 between the ground conductor 3 and the line conductor 2 on the same direction side as the direction in which the line conductor 2 is bent is narrower than the interval W1 of the portion that is not the curved portion R.

  The direction in which the curve bends means the side where the center of curvature of the curve exists, and the side opposite to the direction in which the curve bends is the opposite side across the curve from the side where this center of curvature exists. It means that there is. In the following description, the same direction as the curve bending direction is also referred to as the inside of the curve, and the direction opposite to the curve bending direction is also referred to as the outside of the curve.

  In the example shown in FIG. 1, the outer side portion of the line conductor 2 in the curved portion R is cut out, and the inner side portion of the line conductor 2 is projected. That is, the line conductor 2 is formed in a shape such that the entire curved portion R is shifted by a certain distance toward the inner side of the curved portion R.

  As another means for widening the interval W2 between the line conductor 2 and the ground conductor 3 in the outer direction of the curved portion R and narrowing the interval W3 between the line conductor 2 and the ground conductor 3 in the inner direction of the curved portion R, Can be in various forms.

  For example, in the example illustrated in FIG. 2, in the curved portion R, the ground conductor 3 on the inner side of the curved portion R is formed as a protruding portion 3 a that protrudes with a constant width. The protrusion width of the typical protrusion 3a is, for example, 0.01 mm. As a result, the distance between the line conductor 2 and the ground conductor 3 in the inner direction of the line conductor 2 can be reduced.

On the other hand, in the curved portion R, the ground conductor 3 on the outer side of the curved portion R is formed in a shape having a cutout portion 3b cut out by a certain width. The notch width of the typical notch 3b is, for example, 0.01 mm. As a result, the distance between the line conductor 2 and the ground conductor 3 in the outer direction of the line conductor 2 can be increased.

  In the example shown in FIG. 2, the curved portion R is formed in a shape such that the entire ground conductor 3 is shifted to the outer side of the curved portion R. As a result, the distance W2 between the line conductor 2 and the ground conductor 3 can be increased on the outer side of the curved portion R, and the distance W3 between the line conductor 2 and the ground conductor 3 can be decreased on the inner side of the curved portion R. it can.

  Moreover, you may implement | achieve by combining the above-mentioned means. For example, in the example shown in FIG. 3, in the curved portion R, a notch 2 a is provided on the side portion on the outer side of the line conductor 2. On the other hand, instead of providing the protruding portion 2b on the inner side of the line conductor 2, the protruding portion 3a is provided on the side of the ground conductor 3 on the inner side. Thus, the distance between the line conductor 2 and the ground conductor 3 is increased on the outer side of the curved part R, and the distance between the line conductor 2 and the ground conductor 3 is decreased on the inner side of the curved part R.

  Further, it may be realized by providing notches 2 a and protrusions 2 b on both sides of the line conductor 2, and providing the protrusions 3 a and notches 3 b on the ground conductor 3 on both sides of the line conductor 2. For example, FIG. 4 shows an example in which the cutout portion 2a and the protruding portion 2b are provided on both sides of the line conductor 2 in the curved portion R, and at the same time, the protruding portion 3a and the cutout portion 3b are provided in the ground conductor 3. .

  In the curved portion R, the gap W2 between the line conductor 2 and the ground conductor 3 in the outer direction of the line conductor 2 is widened, and the gap W3 between the line conductor 2 and the ground conductor 3 in the inner direction is narrowed. The reflection loss of the line can be reduced.

  FIG. 5 is a graph showing the result of simulating the reflection loss of the coplanar line when the frequency is changed to 50 GHz. In FIG. 5, curve A is a plot of the reflection loss in the case of a conventional coplanar line in which the distance between the ground conductors 3 on both sides of one coplanar line A shown in FIG. . Curve B is a plot of the reflection loss of one coplanar line A in the example shown in FIG. It can be seen from the figure that the reflection loss of one coplanar line A in the example shown in FIG. 1 is lower than the reflection loss of the conventional coplanar line.

  When the high-frequency signal is propagated, an electromagnetic field is generated along the line conductor 2 between the side of the line conductor 2 and the side of the ground conductor 3 on both sides. In the straight line portion, a symmetrical electromagnetic field is generated on both sides of the line conductor 2 and a high-frequency signal is propagated. However, in the curved portion R, a phase difference occurs between the inside and the outside of the line conductor 2. It is considered that such disturbance of the electromagnetic field appears as a result of an increase in reflection loss.

  In the wiring board 10 according to an embodiment of the present invention, the distance between the curved conductor R and the ground conductor 3 inside the line conductor 2 is narrow. Therefore, the coupling between the line conductor 2 and the ground conductor 3 is strengthened inside the line conductor 2. On the other hand, the distance from the ground conductor 3 outside the line conductor 2 is wide. Therefore, the coupling between the line conductor 2 and the ground conductor 3 is weak outside the line conductor 2. Therefore, the high-frequency signal propagates mainly through electromagnetic coupling inside the line conductor 2, and the influence of the disturbance of the electromagnetic field caused by the phase difference between the inside and the outside of the curved portion R is alleviated. Is estimated to improve.

  A dielectric material, that is, an electrical insulating material is used for the substrate 1. Specifically, electric circuits generally used for circuit boards, such as flexible boards using polyimide resins, organic boards using resins such as epoxy resins, rigid circuit boards using inorganic materials such as ceramics or glass, etc. Insulating material can be used.

  A line conductor 2 and a ground conductor 3 are formed on the surface of the substrate 1 by plating, printing, vapor deposition, sintering, or the like on a metal conductor made of copper, silver, manganese, molybdenum, or other metals or alloys.

  These wiring boards 10 are used to connect a high-frequency signal inside the high-frequency device 30. FIG. 6 shows an example of the high frequency semiconductor device 30 in which the high frequency semiconductor element 24 is sealed in the semiconductor package 20 as an example of the high frequency device 30 in which the wiring substrate 10 is used. FIG. 7 is a plan view of the semiconductor package 20 shown in FIG.

  For example, in the semiconductor package 20, the casing 21 is formed of a metal such as an iron-nickel-cobalt alloy or a ceramic material such as alumina ceramics. An input / output terminal 22 made of ceramics such as alumina ceramics and having connection conductors for connecting the inside and outside of the semiconductor package 20 is fitted so as to penetrate one side wall of the housing 21.

  In the example shown in FIGS. 6 and 7, the wiring substrate 10 is used as a part of the high-frequency input / output terminal 22 of the semiconductor package 20. A lead terminal or the like (not shown) is connected to an outer portion of the input / output terminal 22 on the frame body 21. The lead terminals are electrically connected to the line conductor 2 and the ground conductor 3 of the wiring board 10 on the input / output terminal 22, respectively. In addition, the electrode of the high-frequency semiconductor element 24 is connected to the other end of the line conductor 2 and the other end of the ground conductor 3 of the wiring board 10 through bonding wires or the like.

  In addition to the example shown in FIG. 6, for example, the wiring substrate 10 may be used for the substrate 23 on which the high-frequency semiconductor element 24 is mounted. In this case, it is connected to the line conductor 2 and the ground conductor 3 of the wiring substrate 10 via the input / output terminal 22 and bonding wires. Further, the high-frequency semiconductor element 24 is connected to the line conductor 2 and the ground conductor 3 via solder bumps or the like.

  Thus, by connecting the external circuit board and the high-frequency semiconductor element 24 in the semiconductor package 20 using the wiring board 10, the high-frequency characteristics of the high-frequency input / output signals are improved. Therefore, the high frequency semiconductor device 30 having good performance can be obtained.

  In addition, this invention is not limited to the above-mentioned embodiment, A various change, improvement, etc. are possible in the range which does not deviate from the summary of this invention.

  For example, in the present embodiment, the wiring board 10 in which the line conductor 2 and the ground conductor 3 are formed on the surface of the board 1 is shown. However, another wiring board 10 is laminated on the upper layer or the lower layer of the wiring board 10, A multilayer wiring board 10 may be used.

  Further, in the present embodiment, the example in which one coplanar line composed of one line conductor 2 and the ground conductors 3 on both sides thereof is described as a representative example, but a plurality of these coplanar lines are arranged in parallel. It is good also as the wiring board 10 which has this coplanar track | line.

1: Substrate 2: Line conductor 2a: Notched portion 2b (of the line conductor): Protruding portion 3: (of the line conductor): Grounding conductor 3a: Protruding portion 3b (of the grounding conductor): Notched portion R (of the grounding conductor) : Curve portion 10: Wiring substrate 20: Semiconductor package 30: High-frequency device

Claims (5)

In a wiring board having a coplanar line comprising a substrate made of a dielectric, a line conductor formed on the surface of the substrate, and a ground conductor disposed on both sides of the line conductor with a space therebetween,
The coplanar line has a curved portion that bends in a curved shape, and on the opposite side to the direction in which the curved portion bends, the interval between the line conductor and the ground conductor is wide, and the same direction as the direction in which the curved portion is bent. On the side, the line conductor and the ground conductor are formed with a narrow interval, and the line conductor is formed by cutting away the side of the curved portion in the direction opposite to the bending direction of the curved portion. In addition, the wiring board is formed so as to protrude in the same direction as the bending direction of the curved portion, and the entire curved portion is shifted by a certain distance in the bending direction of the curved portion . The wiring substrate according to claim 1, wherein the curved portion, wherein said ground conductor in the same direction are formed to protrude to the direction of bending of the curved portion. 3. The wiring board according to claim 1, wherein, in the curved portion, the ground conductor on a side opposite to a direction in which the curved portion is bent is formed by notching. The curved ground conductor disposed between the line conductors, and in the curved portion, the ground conductor on the same direction side as the bending direction of the curved portion is formed to protrude, The ground conductor on the side opposite to the direction in which the curved portion is bent is formed by cutting out, and the entire ground conductor is shifted in the direction opposite to the direction in which the curved portion is bent in the curved portion. The wiring board according to 1. Frequency apparatus characterized by comprising a wiring substrate according to any one of claims 1 to 4, and a high-frequency semiconductor element connected to the coplanar line of the wiring substrate.