JP2015111646A - Multilayer wiring board connection structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten the current path length by enabling visual confirmation of a connection state of a master substrate and a slave substrate.SOLUTION: A multilayer wiring board connection structure includes: a master slave 1 which is made of a dielectric substrate and in which a signal conductor pattern 11 is wired on the upper surface; a slave substrate 2 which is made of a multilayer dielectric substrate and in which a signal conductor pattern 21 is wired in the inner layer; and a half-cut BVH24 which is provided from the outer layer on the surface side opposite to the master substrate 1 of the slave substrate 2 and electrically connects the signal conductor patterns 11, 21; and a connection structure 4 which connects the slave substrate 2 with the master slave 1 at the surface opposite thereto.

Description

  The present invention relates to a connection structure for multilayer wiring boards used in microwave circuits and the like.

  Conventionally, in a multi-layer wiring board connection structure that electrically connects a signal conductor pattern wired on the upper surface of the parent board and a signal conductor pattern wired on the upper surface of the child board, a configuration using a half through hole is known. (For example, refer to Patent Document 1). Here, the half through hole is provided on the end face of the sub board, covers the wall of the hole passing through the upper and lower outer layers with a conductor, and divides the through hole electrically connected to the signal conductor pattern of the sub board. It is a thing. Then, the multi-layered wiring board is connected by electrically connecting to the signal conductor pattern of the parent board by solder using the half through hole.

Japanese Patent Laid-Open No. 9-8167

  However, the conventional multilayer wiring board connection structure as disclosed in Patent Document 1 has a problem when the signal conductor pattern wired to the sub board is configured in the inner layer of the multilayer board. That is, in this case, in order to electrically connect the signal conductor pattern wired on the inner layer of the daughter board and the signal conductor pattern wired on the upper surface of the daughter board and electrically connected to the half through-holes, It is necessary to make an electrical connection by BVH (Blind Via Hole) in which the wall of the hole penetrating between layers is covered with a conductor, and the current path length becomes long. As a result, there is a problem that loss increases.

  Further, since the current path length is increased, the parasitic inductance due to the half through hole is increased, the signal conductor patterns of the parent substrate and the child substrate are mismatched, and the reflection loss is deteriorated. Further, there is a problem that radiation loss from the half through hole becomes large.

  The present invention has been made in order to solve the above-described problems, and provides a multilayer wiring board structure that enables visual confirmation of the connection state of the parent board and the child board and that can shorten the current path length. It is intended to provide.

  The multi-layer wiring board connection structure according to the present invention is composed of a dielectric substrate, a parent substrate having a first signal conductor pattern wired on the upper surface, and a multilayer dielectric substrate, and a second signal conductor pattern is wired on the inner layer. A half-divided BVH that is provided from the outer layer to the inner layer on the opposite surface side of the sub-board and the sub-board of the sub-board and electrically connects the first and second signal conductor patterns, and the main board and the sub-board Are connected to each other on the opposite surface.

  According to this invention, since it comprised as mentioned above, the visual confirmation of the connection state of a parent board | substrate and a child board | substrate is attained, and a current path length can be shortened.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the structure of the multilayer wiring board connection structure concerning Embodiment 1 of this invention, (a) Side perspective drawing, (b) Perspective perspective drawing. It is a figure which shows the structure of the multilayer wiring board connection structure concerning Embodiment 2 of this invention, (a) It is a side perspective view, (b) It is a perspective perspective view. It is a figure which shows the structure of the multilayer wiring board connection structure concerning Embodiment 3 of this invention, (a) Side perspective drawing, (b) Perspective perspective drawing. It is a top view which shows the signal conductor pattern of the multilayer wiring board connection structure concerning Embodiment 3 of this invention. It is a figure which shows the structure of the multilayer wiring board connection structure concerning Embodiment 4 of this invention, (a) Side perspective drawing, (b) Perspective perspective drawing. It is a side perspective view which shows the structure of the multilayer wiring board connection structure based on Embodiment 5 of this invention. It is a perspective perspective view which shows another structure of the multilayer wiring board connection structure concerning Embodiment 5 of this invention. It is a side perspective view which shows the structure of the prior art example of the multilayer wiring board connection structure concerning Embodiment 5 of this invention. It is a side see-through | perspective view which shows the structure of the multilayer wiring board connection structure concerning Embodiment 6 of this invention. It is a side perspective view which shows the structure of the multilayer wiring board connection structure based on Embodiment 7 of this invention. It is a side perspective view which shows the structure of the multilayer wiring board connection structure based on Embodiment 8 of this invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
Embodiment 1 FIG.
1A and 1B are diagrams showing a configuration of a multilayer wiring board connection structure according to Embodiment 1 of the present invention, wherein FIG. 1A is a side perspective view, and FIG. 1B is a perspective perspective view.
As shown in FIG. 1, the multilayer wiring board connection structure includes a parent substrate 1 and a child substrate 2.

  The parent substrate 1 is made of a dielectric substrate, and has a signal conductor pattern (first signal conductor pattern) 11 wired on the upper surface. Further, a ground conductor 12 and a resist layer 13 are provided on the upper surface of the parent substrate 1 at a portion facing the child substrate 2. A ground conductor 14 is provided on the lower surface of the parent substrate 1. The ground conductor 12 and the ground conductor 14 are electrically connected by a through hole 15.

  The sub board 2 is composed of a multilayer dielectric board, and a signal conductor pattern (second signal conductor pattern) 21 is wired in the inner layer. A ground conductor (first ground conductor) 22 and a resist layer 23 are provided on the lower surface of the sub-board 2. In addition, a half-divided BVH 24 obtained by halving the BVH in which the wall of the hole penetrating from the outer layer, which is the opposite surface of the parent substrate 1 to the inner layer where the signal conductor pattern 21 is wired, is covered with a conductor is formed on the end surface of the child substrate 2. Is provided. The half BVH 24 is electrically connected to the signal conductor pattern 21. Then, the signal conductor pattern 11 and the half BVH 24 of the parent substrate 1 are electrically connected by, for example, solder 3.

  Further, a connection structure 4 for connecting the parent substrate 1 and the child substrate 2 is provided on the opposing surfaces of the parent substrate 1 and the child substrate 2. Examples of the connection structure 4 include a structure in which cream solder 41 is disposed in the resist layers 13 and 23 of the parent substrate 1 and the child substrate 2 and connected by reflow connection.

Next, the effect of the multilayer wiring board connection structure configured as described above will be described.
In the present invention, as shown in FIG. 1, a half BVH 24 is provided on the end face of the sub board 2, and the parent board 1 and the signal conductor patterns 11 and 21 of the sub board 2 are electrically connected through the half BVH 24. The structure. As a result, even when the signal conductor pattern 11 is wired in the inner layer of the daughter board 2, the current path length can be shortened compared to the configuration using the conventional half through hole, and the loss can be reduced. Can be small. Further, since the half-divided BVH 24 is used, it is possible to visually check the connection state of the parent board 1 and the child board 2 as in the conventional case.
Further, since the current path length can be shortened without using the conventional half through hole, the parasitic inductance due to the half through hole does not increase, and the signal conductor patterns 11 and 21 of the parent board 1 and the child board 2 are not matched. Occurrence can be suppressed and deterioration of reflection loss can be avoided. Further, an increase in radiation loss from the half through hole can be suppressed.

  Further, for example, by making the thermal expansion coefficients of the parent board 1 and the child board 2 equal, the sensitivity to disturbance can be made equal, and the mechanical strength of the connection between the parent board 1 and the child board 2 is improved. be able to.

  As described above, according to the first embodiment, since the signal conductor patterns 11 and 21 of the parent board 1 and the child board 2 are electrically connected by the half BVH 24, the parent board 1 and the child board are provided. 2 can be visually confirmed, and the current path length can be shortened.

Embodiment 2. FIG.
2A and 2B are diagrams showing a configuration of a multilayer wiring board connection structure according to Embodiment 2 of the present invention, wherein FIG. 2A is a side perspective view, and FIG. 2B is a perspective perspective view. The multilayer wiring board connection structure according to the second embodiment shown in FIG. 2 includes a ground conductor (second ground conductor) 25 and a half conductor on the sub-board 2 of the multilayer wiring board connection structure according to the first embodiment shown in FIG. A split through hole 26 is added. Other configurations are the same, and the same reference numerals are given and description thereof is omitted.

The ground conductor 25 is provided on the upper surface of the daughter board 2.
The half through hole 26 is provided in the end surface of the sub-board 2 and halves the through hole in which the wall of the hole penetrating the upper and lower surfaces is covered with a conductor. The half through-holes 26 are electrically connected to the ground conductors 22 and 25 on the upper and lower surfaces of the daughter board 2. In FIG. 2, the connection of the ground conductors 22 and 25 through the half through hole 26 also has a function as the connection structure 4 for connecting the parent substrate 1 and the child substrate 2. In this case, in the connection structure 4, the connection is performed using the solder 41b.

As described above, the ground conductors 22 and 25 are provided on the upper and lower surfaces of the child board 2 and are electrically connected by the half through-holes 26, thereby reducing radiation noise from the signal conductor pattern 21 on the inner layer of the child board 2. be able to. In addition, the ground can be strengthened by electrically connecting the ground conductors 22 and 25 through the half through hole 26.
Furthermore, by making it function as the connection structure 4 using the halved through hole 26, the connection state between the halved through hole 26 and the ground conductors 22 and 25 can be visually confirmed, and the parent substrate 1 and the child substrate 2 can be fixed. Therefore, mechanical reliability can be improved.

Embodiment 3 FIG.
3A and 3B are diagrams showing a configuration of a multilayer wiring board connection structure according to Embodiment 3 of the present invention. FIG. 3A is a side perspective view, and FIG. 3B is a perspective perspective view. FIG. 4 is a top view showing signal conductor patterns 11 and 21b of the multilayer wiring board connection structure according to Embodiment 3 of the present invention. The multilayer wiring board connection structure according to the third embodiment shown in FIG. 3 is obtained by changing the signal conductor pattern 21 of the child board 2 of the multilayer wiring board connection structure according to the second embodiment shown in FIG. 2 to a signal conductor pattern 21b. It is. Other configurations are the same, and the same reference numerals are given and description thereof is omitted.

  The signal conductor pattern 21b is wired in the inner layer of the daughter board 2 as shown in FIGS. The signal conductor pattern 21b has a wide portion 211 in which the pattern width is partially enlarged in the vicinity of the half BVH 24.

  Thus, by providing the signal conductor pattern 21b with the wide portion 211 having a wide pattern width in the vicinity of the half BVH 24, the reflection loss can be reduced. This is because the wide portion 211 of the signal conductor pattern 21b has a function as a matching element, and the capacitance formed by the wide portion 211 cancels the parasitic inductance generated by the half BVH 24.

Embodiment 4 FIG.
5A and 5B are diagrams showing a configuration of a multilayer wiring board connection structure according to Embodiment 4 of the present invention, wherein FIG. 5A is a side perspective view, and FIG. 5B is a perspective perspective view. The multilayer wiring board connection structure according to the fourth embodiment shown in FIG. 5 has a signal conductor pattern (third signal conductor pattern) 27 and a sub-board 2 of the multilayer wiring board connection structure according to the first embodiment shown in FIG. A BVH (second BVH) 28 is added, and the signal conductor pattern 21 and the half BVH 24 are electrically connected via the signal conductor pattern 27 and the BVH 28. Other configurations are the same, and the same reference numerals are given and description thereof is omitted.

The signal conductor pattern 27 is wired in the inner layer between the outer layer of the child substrate 2 facing the parent substrate 1 and the inner layer where the signal conductor pattern 21 is wired.
The BVH 28 is provided between the inner layers where the second and third signal conductor patterns 21 and 27 of the daughter board 2 are wired, and electrically connects the second and third signal conductor patterns 21 and 27.
Further, the half-divided BVH 24 is electrically connected to the signal conductor pattern 27 through the signal conductor pattern 27 and the BVH 28 by being electrically connected to the signal conductor pattern 27.

  In the multilayer wiring board connection structure according to the fourth embodiment, the signal conductor pattern 21 provided on the sub board 2 is connected to the signal conductor pattern 11 provided on the parent board 1 by the halved BVH 24 only in the first embodiment. The length of the half BVH 24 is shortened with respect to the structure. Therefore, the radiation loss from the half BVH 24 can be further reduced while enabling visual confirmation of the electrical connection state (state of the solder 3) of the signal conductor pattern 21.

Embodiment 5 FIG.
FIG. 6 is a side perspective view showing the configuration of the multilayer wiring board connection structure according to Embodiment 5 of the present invention. The multilayer wiring board connection structure according to the fifth embodiment shown in FIG. 6 is different from the multilayer wiring board connection structure according to the first embodiment shown in FIG. 1 in that a ground conductor (second ground conductor) 25 and side wall through-hole groups are provided. 29, 30, BVH 31 for power feeding, and a short circuit structure 32 are added. Other configurations are the same, and the same reference numerals are given and description thereof is omitted.

The ground conductor 25 is provided on the upper surface of the daughter board 2.
The through-hole groups 29 and 30 for side walls are arranged in the line direction of the signal conductor pattern 21 with an interval of ½ or less of the cutoff wavelength and connected to the ground conductors 22 and 25. The through-hole groups 29 and 30 for side walls constitute two side walls to constitute a dielectric waveguide.

  The power feeding BVH 31 is electrically connected to one of the signal conductor pattern 21 and the ground conductors 22 and 25 (the ground conductor 22 in FIG. 6), and is formed perpendicular to the dielectric layer of the daughter board 2. It has been done. Power is supplied to the dielectric waveguide by the power supply BVH 31.

  The short-circuit structure 32 is provided between the power supply BVH 31 and the half BVH 24 and has a window 321 through which the signal conductor pattern 21 passes. With this short-circuit structure 32, the traveling direction of the electromagnetic wave in the dielectric waveguide can be determined in a direction away from the half BVH 24 along the line direction of the signal conductor pattern 21. As shown in FIG. 6, the short-circuit structure 32 is disposed at a position that is a quarter of the guide wavelength away from the power supply BVH 31. Further, as shown in FIG. 7, the short-circuit structure 32 may be provided on the surface on which the half BVH 24 is provided.

FIG. 8 shows a side perspective view of a conventional example of the multilayer wiring board connection structure according to Embodiment 5. In FIG.
Conventionally, as shown in FIG. 8, power supply to the power supply BVH 103 provided on the daughter board 2 on which the dielectric waveguide is formed is performed from the parent board 1. Therefore, the signal conductor pattern 11 provided on the surface layer of the mother board 1 and the BVH 102 electrically connected via the signal conductor pattern 101 provided on the inner layer are provided on the mother board 1 and connected to the power supply BVH 103 of the child board 2. It was necessary to make an electrical connection via 104.

  As described above, conventionally, the connection is complicated, and it is difficult to visually check the connection state between the parent board 1 and the child board 2, which may cause a connection failure. On the other hand, in the multilayer wiring board connection structure according to the fifth embodiment shown in FIGS. 6 and 7, it is possible to visually check the connection state of the parent board 1 and the child board 2, and the current path length can be shortened. .

Embodiment 6 FIG.
FIG. 9 is a side perspective view showing the structure of the multilayer wiring board connection structure according to Embodiment 6 of the present invention. The multilayer wiring board connection structure according to the sixth embodiment shown in FIG. 9 is obtained by providing partition walls 33 in the multilayer wiring board connection structure according to the fifth embodiment shown in FIG. Other configurations are the same, and only different parts will be described.

  The partition wall 33 is arranged on the side opposite to the short-circuit structure 32 side with respect to the power supply BVH 31 (the rear side in the radio wave direction of the power supply BVH 31). The partition wall 33 is configured in a shape that functions as a capacity with respect to the power supply BVH 31. By providing the partition wall 33, the distance between the power supply BVH 31 and the short-circuit structure 32 can be made ¼ or less of the guide wavelength. Therefore, in addition to the effect in the fifth embodiment, there is an effect that the sub board 2 can be downsized.

Embodiment 7 FIG.
FIG. 10 is a side perspective view showing the configuration of the multilayer wiring board connection structure according to Embodiment 7 of the present invention. The multilayer wiring board connection structure according to the seventh embodiment shown in FIG. 10 is obtained by changing the power supply BVH 31 of the multilayer wiring board connection structure according to the fifth embodiment shown in FIG. 6 to a power supply BVH 31b. Other configurations are the same, and the same reference numerals are given and description thereof is omitted.

  Similarly to the power supply BVH 31, the power supply BVH 31 b is electrically connected to one of the signal conductor pattern 21 and one of the ground conductors 22 and 25 (the ground conductor 22 in FIG. 10). It is formed perpendicular to the layer. Power is supplied to the dielectric waveguide by the power supply BVH 31b. The power supply BVH 31b according to the seventh embodiment is configured such that the diameter increases toward the electrically connected ground conductor (ground conductor 22 in FIG. 10) side.

  By using the BVH 31b for power supply whose diameter gradually increases, in addition to the effect in the fifth embodiment, the function of relaxing impedance mismatch with the dielectric waveguide can be obtained, and the effect of improving the reflection characteristics can be obtained. is there.

Embodiment 8 FIG.
FIG. 11 is a side perspective view showing the structure of the multilayer wiring board connection structure according to Embodiment 8 of the present invention. The multilayer wiring board connection structure according to the eighth embodiment shown in FIG. 11 is obtained by removing the power supply BVH 31 from the multilayer wiring board connection structure according to the fifth embodiment shown in FIG. Other configurations are the same, and the same reference numerals are given and description thereof is omitted.

  The partition wall 34 is disposed at the center between the two side walls of the dielectric waveguide, and is electrically connected to one of the signal conductor pattern 21 and the ground conductors 22 and 25 (the ground conductor 25 in FIG. 11). It is connected. Further, as shown in FIG. 11, the partition wall 34 is formed in a stepped shape in which the thickness decreases toward the direction away from the half-divided BVH 24.

  By providing this partition wall 34, in addition to the effect in the fifth embodiment, it functions as an impedance transformer between the impedance of the strip line formed by the signal conductor pattern 21 and the impedance of the dielectric waveguide, and the reflection characteristics are improved. effective.

  In the present invention, within the scope of the invention, any combination of the embodiments, or any modification of any component in each embodiment, or omission of any component in each embodiment is possible. .

  DESCRIPTION OF SYMBOLS 1 Parent substrate, 2 Child substrate, 3 Solder, 4 Connection structure, 11 Signal conductor pattern (1st signal conductor pattern), 12 Ground conductor, 13 Resist layer, 14 Ground conductor, 15 Through hole, 21, 21b Signal conductor pattern (Second signal conductor pattern), 22 ground conductor (first ground conductor), 23 resist layer, 24 half BVH, 25 ground conductor (second ground conductor), 26 half through hole, 27 signal conductor pattern (Third signal conductor pattern), 28 BVH (second BVH), 29, 30 Side wall through hole group, 31, 31b BVH for power feeding, 32 Short circuit structure, 33, 34 Partition, 41 Cream solder, 41b Solder, 211 Wide part, 321 window.

Claims (10)

A parent substrate made of a dielectric substrate and having a first signal conductor pattern wired on the upper surface;
A sub-board made of a multi-layer dielectric substrate and having a second signal conductor pattern wired on the inner layer;
BVH (blind via hole) provided from the outer layer to the inner layer on the side of the child substrate facing the parent substrate and electrically connecting the first and second signal conductor patterns;
A multilayer wiring board connection structure comprising: a connection structure for connecting the parent substrate and the child substrate on opposite surfaces. First and second ground conductors provided on the upper and lower surfaces of the child board;
2. The multilayer wiring board connection structure according to claim 1, further comprising a half-divided through hole provided on the sub-board and electrically connecting the first and second ground conductors. 3. The multilayer wiring board connection structure according to claim 1, wherein the second signal conductor pattern has a wide pattern width in the vicinity of the half-divided BVH. 4. A third signal conductor pattern wired in an inner layer between an outer layer of the child substrate facing the parent substrate and an inner layer wired with the second signal conductor pattern;
A second BVH provided between the inner layers where the second and third signal conductor patterns of the daughter board are wired, and electrically connecting the second and third signal conductor patterns;
4. The multilayer wiring board connection structure according to claim 1, wherein the half-divided BVH is electrically connected to the third signal conductor pattern. 5. The multilayer wiring board connection structure according to any one of claims 1 to 4, wherein the parent substrate and the child substrate have the same thermal expansion coefficient. First and second ground conductors provided on the upper and lower surfaces of the child board;
For the side wall that is arranged in the line direction of the second signal conductor pattern at an interval of 1/2 or less of the cutoff direction and is connected to the first and second ground conductors to form two side walls of the dielectric waveguide Through-hole groups,
BVH for feeding that is electrically connected to one of the second signal conductor pattern and the first and second ground conductors and feeds the dielectric waveguide;
2. The multilayer wiring board according to claim 1, further comprising: a short-circuit structure provided between the feeding BVH and the half-divided BVH and having a window through which the second signal conductor pattern passes. Connection structure. The multilayer wiring board connection structure according to claim 6, wherein the short-circuit structure is provided on a surface on which the half-divided BVH is provided. A partition wall disposed on the side opposite to the short-circuit structure side with respect to the power supply BVH,
The multilayer wiring board connection structure according to claim 6, wherein a distance between the power supply BVH and the short-circuit structure is ¼ or less of the in-tube wavelength. The multilayer wiring board connection structure according to claim 6, wherein a diameter of the power feeding BVH is configured to increase toward the electrically connected ground conductor side. First and second ground conductors provided on the upper and lower surfaces of the child board;
For the side wall that is arranged in the line direction of the second signal conductor pattern at an interval of 1/2 or less of the cutoff direction and is connected to the first and second ground conductors to form two side walls of the dielectric waveguide Through-hole groups,
Disposed in the center between two side walls of the dielectric waveguide, and electrically connected to one of the second signal conductor pattern and the first and second ground conductors; A partition wall configured in a staircase shape whose thickness decreases in a direction away from the divided BVH;
The multilayer wiring board connection structure according to claim 1, further comprising: a short-circuit structure provided between the partition wall and the half-divided BVH and having a window through which the second signal conductor pattern passes. .

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