JP5241477B2 - Wiring board and wiring module - Google Patents

Description

  The present invention relates to a high-frequency wiring board among wiring boards. The high frequency wiring board can be suitably used in the field of high frequency communication such as optical communication and wireless communication.

  Conventionally, a wiring board used in the field of high-frequency communication has been provided with a plurality of electric wirings for inputting and outputting signals from electronic components such as semiconductor elements. And it is calculated | required to reduce the dispersion | variation in the propagation time of the high frequency signal in these electric wiring. Therefore, as disclosed in Patent Document 1, a wiring board in which a curved portion is provided in the middle of each electric wiring has been proposed.

In the wiring board disclosed in Patent Document 1, a curved portion is provided in the middle of each electrical wiring, and the length of each electrical wiring is made substantially equal, thereby reducing variations in the propagation time of high-frequency signals. Yes. Patent Document 1 also discloses a wiring board in which variation in propagation time in each electric wiring is reduced by overlapping electric insulating layers having different relative dielectric constants.
Japanese Patent Laid-Open No. 11-8444

  However, when a curved portion is provided in the middle of each electrical wiring and the length of each electrical wiring is made substantially equal, a region for providing the curved portion is required, and thus it may be difficult to reduce the size of the wiring board. . In addition, when a wiring board in which electrical insulating layers having different relative dielectric constants are stacked is used, it is necessary to stack electrical insulating layers having a relative dielectric constant corresponding to the length of each electrical wiring. Therefore, the manufacturing cost may increase.

  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 can be easily miniaturized and can easily suppress variations in the propagation time of high-frequency signals.

  The wiring board of the present invention is provided on the main surface of the dielectric substrate having a main surface of the dielectric substrate, a first signal line disposed on the main surface of the dielectric substrate, A second signal line shorter than the first signal line, a first reference conductor provided along the first signal line and connected to a reference potential, and along the second signal line And a plurality of second reference conductors that are connected to a reference potential and spaced apart in the wiring direction of the second signal line.

  According to the wiring board of the present invention, a plurality of second reference conductors are provided along the second signal line, connected to the reference potential, and spaced apart in the wiring direction of the second signal line. In the second signal line, the signal propagation mode changes between a portion provided adjacent to the second reference conductor and a portion positioned between the plurality of second reference conductors. For this reason, the signal transmission speed in the portion located between the plurality of second reference conductors is lower than the signal transmission speed in the portion adjacent to the second reference conductor. Thereby, the signal propagation time in the second signal line having a relatively short wiring distance can be made closer to the signal propagation time in the first signal line having a relatively long wiring distance. As a result, it is possible to easily suppress variations in propagation time that occur between the first signal line and the second signal line.

  Hereinafter, the wiring board of the present invention will be described in detail with reference to the drawings.

  As shown in FIGS. 1 to 4, the wiring substrate 1 according to the first embodiment of the present invention includes a dielectric substrate 3 having a main surface, and a first substrate disposed on the main surface of the dielectric substrate 3. The signal line 5 is disposed on the main surface of the dielectric substrate 3, and is provided along the first signal line 5, the second signal line 7 shorter than the first signal line 5, and the reference potential And a plurality of second reference conductors that are provided along the second signal line 7 and connected to the reference potential and spaced apart in the wiring direction of the second signal line 7 11.

  As described above, the wiring board 1 according to the present embodiment is provided along the second signal line 7 and connected to the reference potential, and is separated from each other in the wiring direction of the second signal line 7. A reference conductor 11 is provided. Therefore, the signal propagation time in the second signal line 7 having a relatively short wiring distance can be made closer to the signal propagation time in the first signal line 5 having a relatively long wiring distance. As a result, it is possible to easily suppress variations in propagation time that occur between the first signal line 5 and the second signal line 7.

  The wiring board 1 according to the present embodiment includes a dielectric substrate 3 having a main surface. As the dielectric substrate 3, an insulating member can be used. Specifically, ceramic materials mainly composed of aluminum oxide, aluminum nitride, silicon nitride, mullite, etc., glass ceramic materials formed by firing glass or a mixture of glass and ceramic filler, epoxy resin, polyimide resin Organic resin materials such as fluororesins such as tetrafluoroethylene resin, organic resin-ceramic (including glass) composite materials, and the like can be used.

  In particular, it is preferable to use a ceramic material for the dielectric substrate 3. This is because the ceramic material is a low-loss material and can transmit a high-frequency signal without loss. In addition, since the thermal conductivity is high and the change in physical properties due to temperature is small, it is possible to suppress fluctuations in characteristics due to heat generated in a resistor or the like.

  Further, the dielectric substrate 3 in the present embodiment has a plurality of through holes penetrating from the main surface to the back surface. In addition, via conductors 13 are disposed in these through holes, respectively. The via conductor 13 is electrically connected to either the first reference conductor 9 or the second reference conductor 11 on the main surface of the dielectric substrate 3.

  The wiring board 1 according to the present embodiment includes a first signal line 5 and a second signal line 7 disposed on the main surface of the dielectric substrate 3. At this time, the second signal line 7 is arranged to be shorter than the first signal line 5. These signal lines are used as wirings for inputting or outputting signals to the electronic component 23 disposed on the main surface of the wiring board 1.

  The first signal line 5 and the second signal line 7 are easily connected to the outside, so that the first signal line at one end where the electronic component is electrically connected is provided. The distance between the first signal line 5 and the second signal line 7 at the other end connected to the external wiring is wider than the distance between the second signal line 7 and the second signal line 7. By electrically connecting one end of the first signal line 5 and the second signal line 7 and the electronic component, external wiring can be easily connected to a small electronic component.

  On the other hand, in order to easily connect external wiring to such a small electronic component, the first signal line at one end rather than the distance between the first signal line 5 and the second signal line 7 at one end. Therefore, it is necessary to change the lengths of the first signal line 5 and the second signal line 7. However, when the lengths of the first signal line 5 and the second signal line 7 are changed, a time difference occurs in the signal propagation time. In particular, when not only the first signal line 5 and the second signal line 7 but also a large number of signal lines are provided, there is a possibility that the propagation time in these signal lines varies. As will be described later, the wiring board 1 according to the present embodiment includes a plurality of second reference conductors 11 that are spaced apart from each other, thereby reducing the above-described shift in propagation time.

  As the first signal line 5 and the second signal line 7, it is preferable to use a member having good electrical conductivity. For example, a metal such as Au, Ag, Cu, Al, Pt, Pd, W, and Mo is used. A member can be used.

  The wiring board 1 according to the present embodiment includes a first reference conductor 9 that is provided along the first signal line 5 and connected to a reference potential. By including the first reference conductor 9 as described above, it is possible to reduce the possibility of short circuit between a plurality of signal lines and resonance between the first signal line 5 and the first reference conductor 9. can do. Therefore, it becomes possible to propagate the signal stably.

  As the first reference conductor 9, it is preferable to use a member having good electrical conductivity as in the first signal line 5. Specifically, metal members such as Au, Ag, Cu, Al, Pt, Pd, W, and Mo can be used.

  The wiring board 1 according to the present embodiment includes a plurality of second reference conductors 11 provided along the second signal line 7 and connected to a reference potential. By providing such a second reference conductor 11, similarly to the first reference conductor 9, a short circuit between a plurality of signal lines, and a relationship between the second signal line 7 and the second reference conductor 11. It is possible to reduce the possibility of resonance between the two.

  The plurality of second reference conductors 11 according to the present embodiment are disposed so as to be separated in the wiring direction of the second signal line 7. In other words, the second signal line 7 includes a portion where the second reference conductor 11 is provided (hereinafter also referred to as the first portion 7a) and a portion where the other second reference conductor 11 is not provided. (Hereinafter also referred to as second portion 7b).

  As described above, when the second signal line 7 has the first part 7a and the second part 7b, the propagation mode of the electric signal changes between the first part 7a and the second part 7b. Therefore, the propagation speed of the signal in the second part 7b is slower than the propagation speed of the signal in the first part 7a. Thereby, the signal propagation time in the second signal line 7 having a relatively short wiring distance can be made closer to the signal propagation time in the first signal line 5 having a relatively long wiring distance. In addition, what is necessary is just to set the space | interval between the several 2nd reference conductors 11 arrange | positioned mutually spaced apart according to the difference of the length of the 1st signal track | line 5 and the 2nd signal track | line 7.

  Further, the width of the second reference conductor 11 is preferably smaller than ½ of the wavelength of the signal propagated in the first signal line 5 and the second signal line 7. Alternatively, the interval between the plurality of second reference conductors 11 is preferably different depending on the taper or the step shape on the side of the signal line provided on the side and the opposite side. Thereby, the space | interval between the some 2nd reference conductors 11 arrange | positioned so that it may mutually space apart can work | function as a stub line, and can reduce possibility that resonance etc. will arise.

  As the second reference conductor 11, it is preferable to use a member having good electrical conductivity like the first signal line 5. Specifically, metal members such as Au, Ag, Cu, Al, Pt, Pd, W, and Mo can be used.

  In addition, the wiring board 1 according to the present embodiment is provided along the first signal line 5 on the side opposite to the first reference conductor 9 and the second side on the side opposite to the second reference conductor 11. A plurality of third reference conductors 15 are further provided along the signal line 7 and connected to the reference potential. In other words, the first signal line 5 is located between the first reference conductor 9 and the third reference conductor 15, and the second signal line 7 is the second reference conductor 11 and the third reference conductor. 15 is located between.

The wiring board 1 according to the present embodiment further includes the third reference conductor 15 arranged as described above, thereby resonating between a plurality of signal lines and between the signal lines and the reference conductor. This is because the possibility of occurrence of the occurrence can be reduced. Therefore, it becomes possible to propagate the signal more stably.

  As the second reference conductor 11, it is preferable to use a member having good electrical conductivity like the first signal line 5. Specifically, metal members such as Au, Ag, Cu, Al, Pt, Pd, W, and Mo can be used.

  In addition, as in the wiring board 1 according to the present embodiment, the second signal line 7 is located between the plurality of second reference conductors 11 rather than the width of the portion where the second signal lines 7 are provided side by side with the plurality of second reference conductors 11. It is preferable that it is a shape with a large width | variety in the part located. Thereby, characteristic impedance matching can be performed satisfactorily. Therefore, the wiring board 1 having low reflection can be obtained.

  At this time, it is more preferable that the second signal line 7 has a convex portion 19 on one side facing the second reference conductor 11 at a portion located between the plurality of second reference conductors 11. By having such a convex portion 19, the width at the portion located between the plurality of second reference conductors 11 is larger than the width at the portion provided alongside the plurality of second reference conductors 11. Can better propagate signals in a higher frequency band. This is because the distance from the third reference conductor 15 provided on the other side of the second signal line 7 can be kept constant, so that discontinuity of the signal propagation mode can be suppressed.

  Further, like the wiring board 1 according to the present embodiment, the second signal line 7 has a straight line portion, and a plurality of second reference conductors 11 are arranged in the wiring direction of the second signal line 7 in the straight line portion. It is preferable that they are separated. This is because the generation of noise can be suppressed as compared with the case where the plurality of second reference conductors 11 are separated from each other in the curved portion of the second signal line 7. Further, compared to a case where the plurality of second reference conductors 11 are separated from each other in the curved portion of the second signal line 7, it is possible to reduce radiation loss due to electromagnetic wave radiation.

  As already shown, the dielectric substrate 3 in this embodiment has a plurality of through holes penetrating from the main surface to the back surface, and via conductors 13 are disposed in these through holes, respectively. A reference conductor layer 19 electrically connected to the via conductor 13 is disposed on the back surface of the dielectric substrate 3. By connecting the first reference conductor 9, the second reference conductor 11 and the third reference conductor 15 to an external ground electrode (not shown) through the reference conductor layer 19, the first reference conductor 9, The second reference conductor 11 and the third reference conductor 15 can be set to a reference potential.

  A plurality of via conductors 13 are preferably arranged in each of the first reference conductor 9, the second reference conductor 11, and the third reference conductor 15. Thereby, it is possible to reduce the possibility of short circuit between a plurality of signal lines and resonance between the signal line and the reference conductor. Therefore, it becomes possible to propagate the signal stably.

  In particular, the plurality of via conductors 13 disposed in each of the first reference conductor 9, the second reference conductor 11, and the third reference conductor 15 are the first signal line 5 or the second signal line. It is more preferable that the distance between the first and second terminals is substantially constant. In other words, the plurality of via conductors 13 are preferably arranged along the first signal line 5 or the second signal line 7.

  Further, the interval between the plurality of via conductors 13 is preferably smaller than ¼ of the wavelength of the signal propagated in the first signal line 5 and the second signal line 7. This is because the possibility that a resonance phenomenon occurs in each of the first reference conductor 9, the second reference conductor 11, and the third reference conductor 15 can be suppressed.

  As the via conductor 13, it is preferable to use a member having good electrical conductivity like the first signal line 5. Specifically, metal members such as Au, Ag, Cu, Al, Pt, Pd, W, and Mo can be used.

  Next, a second embodiment of the present invention will be described.

  As shown in FIG. 5, in the wiring board 1 of the present embodiment, the third reference conductor 15 is located between the first signal line 5 and the second signal line 7 as compared with the first embodiment. It is characterized by that. Further, the second reference conductor 11 is disposed on the opposite side of the second signal line 7 from the side facing the first signal line 5.

  In the wiring board 1 according to the present embodiment, the third reference conductor 15 is provided on the other side of the first signal line 5 and connected to the reference potential, and is provided on the other side of the second signal line 7. In addition, the third reference conductor 15 connected to the reference potential is not separately provided, but one third reference conductor 15 is connected to the first signal line 5 and the second signal line 7. Are sharing. Therefore, the interval between the first signal line 5 and the second signal line 7 can be reduced. As a result, the wiring board 1 can be reduced in size.

  Next, a third embodiment of the present invention will be described.

  As shown in FIG. 6, the wiring board 1 of the present embodiment includes a dielectric substrate 3 having a main surface, a first signal line 5 disposed on the main surface of the dielectric substrate 3, and a dielectric substrate. 3, a second signal line 7 that is shorter than the first signal line 5, and a plurality of signals that are provided along the first signal line 5 and connected to the reference potential and spaced apart from each other. First reference conductor 9 and a plurality of second reference conductors 11 which are provided along the second signal line 7 and are connected to the reference potential and spaced apart from each other. The distance L2 between the plurality of second reference conductors 11 is larger than the distance L1 between the plurality of first reference conductors 9.

  As already described in the first embodiment, when the lengths of the first signal line 5 and the second signal line 7 are changed, a time difference occurs in the signal propagation time. In particular, when not only the first signal line 5 and the second signal line 7 but also a large number of signal lines are provided, there is a possibility that the propagation time in these signal lines varies.

  In the wiring board 1 according to the present embodiment, a plurality of first reference conductors 9 separated in the wiring direction of the first signal line 5 and a plurality of second references separated in the wiring direction of the second signal line 7. A conductor 11 is provided. In other words, the first signal line 5 has a portion where the first reference conductor 9 is provided and a portion where the other first reference conductor 9 is not provided, and the second signal line 7. However, it has a portion where the second reference conductor 11 is provided and a portion where the other second reference conductor 11 is not provided.

  The length L2 of the portion of the second signal line 7 where the second reference conductor 11 is not provided is the length L1 of the portion of the first signal line 5 where the first reference conductor 9 is not provided. Longer than. That is, the length of the second signal line 7 that is slower than the propagation speed of the signal is longer than the length of the first signal line 5 that is slower than the propagation speed of the signal. Therefore, the signal propagation time in the second signal line 7 having a relatively short wiring distance can be made closer to the signal propagation time in the first signal line 5 having a relatively long wiring distance. As a result, it is possible to easily suppress variations in propagation time that occur between the first signal line 5 and the second signal line 7.

  In addition, it arrange | positioned so that the space | interval between the some 1st reference conductors 9 arrange | positioned so that it might be spaced apart in the wiring direction of the 1st signal track | line 5, and the wiring direction of the 2nd signal track | line 7 The interval between the plurality of second reference conductors 11 can be set according to the difference in length between the first signal line 5 and the second signal line 7.

  Next, a fourth embodiment of the present invention will be described.

  As shown in FIG. 7, the wiring board 1 of the present embodiment has a third reference conductor 15 positioned between the first signal line 5 and the second signal line 7 as compared with the third embodiment. It is characterized by that. The first reference conductor 9 is disposed on the opposite side of the first signal line 5 from the side facing the second signal line 7. Further, the second reference conductor 11 is disposed on the opposite side of the second signal line 7 from the side facing the first signal line 5.

  In the wiring board 1 according to the present embodiment, since the third reference conductor 15 is located between the first signal line 5 and the second signal line 7, the first signal line 5 and the second signal line 5 are connected to each other. Insulation with the signal line 7 can be kept good.

  Further, in the wiring board 1 according to the present embodiment, the third reference conductor 15 provided on the other side of the first signal line 5 and connected to the reference potential, and the other side of the second signal line 7. The third reference conductor 15 is not disposed separately from the third reference conductor 15 connected to the reference potential and the third reference conductor 15 is connected to the first signal line 5 and the second signal line. 7 and shared. Therefore, the interval between the first signal line 5 and the second signal line 7 can be reduced. As a result, the wiring board 1 can be reduced in size.

  Next, a wiring module according to an embodiment of the present invention will be described.

  As shown in FIG. 8, the wiring module 21 of the present embodiment is electrically connected to the wiring substrate 1 typified by the above embodiment and one end of the first signal line 5 and the second signal line 7. And an external wiring 25 electrically connected to one end of each of the first signal line 5 and the second signal line 7. At this time, the distance between the first signal line 5 and the second signal line 7 at one end electrically connected to the electronic component 23 is larger than the distance at the other end connected to the external wiring 25. The distance between the first signal line 5 and the second signal line 7 is wide.

  As described above, the wiring module 21 according to the present embodiment includes the wiring board 1 typified by the above-described embodiment, and thus propagation that occurs between the first signal line 5 and the second signal line 7. Time variations can be easily suppressed. Therefore, the electronic component 23 can be stably operated normally.

  As the electronic component 23 in the present embodiment, for example, a semiconductor element such as a laser diode, a photodiode, an amplifier, an IC, and an LSI can be used.

  Note that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the present invention. For example, in the above-described embodiment, the form having two second embodiments as the plurality of second reference conductors that are isolated from each other has been described. Can be divided into two or more locations without any problem.

It is a perspective view which shows the wiring board in the 1st Embodiment of this invention. It is a top view of embodiment shown in FIG. It is AA sectional drawing of embodiment shown in FIG. It is an expanded sectional view of the area | region A shown in FIG. It is a top view which shows the wiring board in the 2nd Embodiment of this invention. It is a top view which shows the wiring board in the 3rd Embodiment of this invention. It is a top view which shows the wiring board in the 4th Embodiment of this invention. It is a perspective view showing a wiring module concerning one embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Wiring board 3 ... Dielectric substrate 5 ... 1st signal line 7 ... 2nd signal line 7a ... 1st site | part 7b ... 2nd site | part 9 ... First reference conductor 11 ... second reference conductor 13 ... via conductor 15 ... third reference conductor 17 ... convex 19 ... reference conductor layer 21 ... wiring module 23 ... Electronic components 25 ... External wiring

Claims (6)

A dielectric substrate having a main surface;
A first signal line disposed on a main surface of the dielectric substrate;
A second signal line disposed on a main surface of the dielectric substrate and shorter than the first signal line;
A first reference conductor provided along the first signal line and connected to a reference potential;
A wiring board comprising a plurality of second reference conductors provided along the second signal line and connected to a reference potential and spaced apart in the wiring direction of the second signal line. A dielectric substrate having a main surface;
A first signal line disposed on a main surface of the dielectric substrate;
A second signal line disposed on a main surface of the dielectric substrate and shorter than the first signal line;
A plurality of first reference conductors provided along the first signal line and connected to a reference potential and spaced apart from each other;
A plurality of second reference conductors provided along the second signal line and connected to a reference potential and spaced apart in the wiring direction of the second signal line;
A wiring board, wherein a distance between the plurality of second reference conductors is larger than a distance between the plurality of first reference conductors. The second signal line has a convex portion in a portion located between the plurality of second reference conductors on the side facing the plurality of second reference conductors, and the plurality of second reference lines The wiring board according to claim 1, wherein a width of a portion located between the plurality of second reference conductors is larger than a width of a portion provided alongside the conductor.   The wiring board according to claim 1, wherein the second signal line has a straight line portion, and the plurality of second reference conductors are separated from each other in the straight line portion.   The first reference conductor is provided along the first signal line on the side opposite to the first reference conductor, and is provided along the second signal line on the side opposite to the second reference conductor. The wiring board according to claim 1, further comprising a plurality of third reference conductors connected to each other. The wiring board according to any one of claims 1 to 5 , an electronic component electrically connected to one end of each of the first signal line and the second signal line, and the first signal A wiring module comprising a line and an external wiring electrically connected to one end of the second signal line.

Images