JP2010087615A - Connection structure for differential transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a connection structure for differential transmission for excellent different transmission without increasing a wiring density in a mounting board for mounting a dielectric substrate provided with a broadside connecting strip line. <P>SOLUTION: Regarding a connection pad 5, a connection pad 5a and a connection pad 5b are provided along the extending direction of a surface layer line 9a and a surface layer line 9b. A juxtaposition conductor 16a, a juxtaposition conductor 16b and a connection conductor 17a, a connection conductor 17b which are connection regions are provided with a boundary line 15 as a boundary. A juxtaposition conductor 16a and a juxtaposition conductor 16b are provided in parallel on the main surface 8a of a resin substrate 8 while keeping a prescribed interval. The connection conductor 17a is linearly connected to the connection pad 5a along the extending direction of the juxtaposition conductor 16a without bending. The connection conductor 17b includes two bend parts 18 and 19, includes a bend part 20 to the juxtaposition conductor 16b near the boundary line 15 further, and is connected to the connection pad 5b. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a differential transmission connection structure suitable for mounting a semiconductor integrated circuit such as a semiconductor element and an optical semiconductor element operating at high speed.

  Conventionally, in the internal wiring structure of package mounting parts and surface mountable electronic parts that are mounted and sealed with semiconductor elements such as ICs and LSIs that operate at high speed, the purpose is to transmit high-speed high-frequency signals accurately and efficiently. A differential transmission line structure is often adopted. In a conventional differential transmission wiring structure, a pair of signal conductors are provided side by side on the main surface of a dielectric substrate that also serves as a support and an insulator.

  The differential transmission can double the supply of voltage or current to the load by adopting a configuration in which the voltage or current in each of the signal conductor pairs is out of phase with each other and the difference is consumed by the load. In addition, in the case where the same external noise is applied to each of the signal conductor pairs, there is an advantage that the applied external noise is canceled because a difference in voltage or current is taken at the load. Therefore, it has been regarded as an effective means for transmitting high-speed pulses.

  The conventional differential transmission wiring structure has a structure in which signal conductors are arranged in parallel on the main surface of the dielectric substrate, that is, a parallel microstrip line form or a parallel strip line form in which such a form is formed as an inner layer. In many cases, the wiring occupation area tends to increase by juxtaposition.

  In order to narrow the electrode terminal pitch in a semiconductor element, for example, in a multilayer wiring board composed of a plurality of dielectric layers, a difference constituted by a pair of conductors facing each other in the thickness direction of the board via an intermediate dielectric layer. A dynamic transmission wiring structure, i.e. a broadside coupled stripline, is preferred.

  When the broadside coupled strip line is applied, the number of dielectric layers is increased, but the wiring density projected onto the main surface of the dielectric substrate is one, so that it is possible to cope with a narrow pitch. In addition, since the coupling between the signal conductors to be paired is coupled between the wiring widths, the coupling between the wiring thicknesses such as the parallel microstrip line becomes denser, so that the crosstalk characteristics are improved. It can be expected (see Patent Document 1).

  By the way, in package parts or electronic parts, electrical connection with the electrode terminals on the mounting wiring board is realized by drawing the signal wirings facing each other through the intermediate layer to the main surface of the board as the surface layer. Can do. For this reason, the conventional broadside-coupled stripline is converted into a parallel microstripline on the surface layer through a conductor structure in the thickness direction that connects the wiring layers such as through holes, and is used for mounting in semiconductor package components and electronic components. Connected to differential terminal. In this case, in the semiconductor package component and the electronic component, the terminal pairs serving as the differential terminals are juxtaposed in the horizontal direction with respect to the extending direction of the wiring, and are particularly provided on the outermost periphery of the terminal array. In the case of having a plurality of differential transmission systems, the differential terminal pairs juxtaposed in the transverse direction with respect to the longitudinal direction are further juxtaposed to occupy most of the terminals arranged on the outermost peripheral portion of the terminal array. It will be.

JP 2004-7657 A

  In the mounting wiring board (mounting board), since the pair wiring which is the differential transmission wiring is provided on the surface layer, the connection pads are juxtaposed in the direction orthogonal to the extending direction of the wiring. In semiconductor elements and electronic components, even if the electrode terminal pitch can be narrowed, on the mounting board side, due to the layout of such connection pads, broadside coupling such as reduced wiring density and narrowed wiring pitch is possible. There was a problem that the advantages of the stripline were impaired.

  An object of the present invention is to provide a differential transmission connection structure capable of good differential transmission without increasing the wiring density in a mounting board on which a dielectric substrate provided with a broadside coupled stripline is mounted. Is to provide.

  The present invention provides a first dielectric substrate and a first signal conductor and a second signal conductor which are arranged in parallel on the main surface of the first dielectric substrate so as to be coupled to each other. A first pair comprising a conductor pair, a first mounting pad provided at an end of the first signal conductor, and a second mounting pad provided at an end of the second signal conductor. A first wiring substrate having a mounting pad pair, a second dielectric substrate facing the first dielectric substrate, and an inner layer of the second dielectric substrate are provided so as to be coupled to each other. A second conductor pair comprising a third signal conductor and a fourth signal conductor; and a second mounting pad pair for connecting the second conductor pair to the first mounting pad pair. , A differential transmission connection structure for connecting to a second wiring board having the first mounting pad pair, The first mounting pad and the second mounting pad are provided along the extending direction of the first conductor pair, and the first conductor pair includes the first signal conductor and the first signal conductor. The juxtaposed region where the second signal conductors are juxtaposed, and the first signal conductor and the second signal conductor are the first mounting pad and the second mounting pad, respectively. And a connection structure for differential transmission having a connection region connected to each other.

  In the present invention, the first conductor pair is provided without a conductor between the first signal conductor and the second signal conductor.

  In the present invention, the first conductor pair is provided with a dielectric between the first signal conductor and the second signal conductor.

  According to the present invention, the first conductor pair is provided between the first signal conductor and the second signal conductor without using any insulator.

  According to the present invention, in the connection region of the first conductor pair, the first signal conductor and the second signal conductor are connected from the end of the juxtaposed region to the first mounting pad pair. It is connected so that it becomes the shortest.

  In the present invention, in the second conductor pair, the third signal conductor and the fourth signal conductor are arranged in parallel in the thickness direction of the second dielectric substrate.

  Further, in the present invention, the second conductor pair is such that the third signal conductor and the fourth signal conductor have a rectangular cross-sectional shape orthogonal to the extending direction, and the long sides of the respective rectangles They are juxtaposed so that they face each other.

In the present invention, the frequency of the electrical signal transmitted through the first conductor pair and the second conductor pair is 10 GHz or more,
The second mounting pad pair includes the outermost pad and the second row from the outermost periphery in a pad group provided on the periphery of the surface of the second dielectric substrate facing the first dielectric substrate. With the pad.

  According to the present invention, the first wiring substrate having the first dielectric substrate, the first conductor pair, and the first mounting pad pair, the second dielectric substrate, and the second conductor. The differential transmission connection structure connects a pair and a second wiring board having a second mounting pad pair.

  In the first mounting pad pair, the first mounting pad and the second mounting pad are provided along the extending direction of the first conductor pair.

  The first conductor pair includes a juxtaposed region in which the first signal conductor and the second signal conductor are juxtaposed, the first signal conductor, and the second signal conductor. Each have a connection region connected to the first mounting pad and the second mounting pad.

  Thus, by providing the connection region, the first signal conductor and the second signal conductor can be connected to the first mounting pad and the second mounting pad, respectively. Become. As a result, the first mounting pad and the second mounting pad can be provided along the extending direction of the first conductor pair, so that a good differential can be achieved without increasing the wiring density. Transmission is possible.

  Hereinafter, a plurality of embodiments for carrying out the present invention will be described with reference to the drawings. Portions corresponding to the matters described in the preceding forms in each embodiment are denoted by the same reference numerals, and overlapping description may be omitted. When only a part of the configuration is described, the other parts of the configuration are the same as those described in the preceding section.

  FIG. 1 is a perspective view showing a connection structure 1 according to a first embodiment of the present invention. FIG. 2 is a plan view showing the connection structure 1. FIG. 3 is a front view showing the connection structure 1. FIG. 4 is a side view showing the connection structure 1.

  The connection structure 1 includes a differential transmission connection structure for connecting a package 2 as a first wiring board and a mounting board 3 as a second wiring board.

  The package 2 and the mounting board 3 are mounted such that the connection pads 4 provided on the package 2 and the connection pads 5 provided on the mounting board 3 are electrically connected by solder balls 12.

  The package 2 includes a dielectric layer 6 that is a second dielectric substrate and an inner layer line pair 7 that is a second conductor pair. The mounting board 3 includes a resin substrate 8 that is a first dielectric substrate and a surface line pair 9 that is a first conductor pair.

  The package 2 is mounted with a semiconductor element (not shown), and the internal wiring of the semiconductor element and the inner layer line pair 7 are connected to transmit a high frequency signal through the inner layer line pair 7. The inner layer line pair 7 includes an inner layer line 7b and an inner layer line 7a, and constitutes a differential transmission wiring structure.

  The inner layer line 7b further includes an inner layer wiring 11a, which is a third signal conductor, a land 11b, and a through conductor 11c. The inner layer line 7a further includes an inner layer wiring 10a, a land 10b, which is a fourth signal conductor, and a through conductor. 10c.

  The inner layer line pair 7 is a differential transmission wiring pair provided on the inner layer of the dielectric layer 6 so as to be coupled to each other, and is a broad side coupled strip line provided in parallel in the thickness direction of the dielectric layer 6. The inner layer wiring 10a and the inner layer wiring 11a are provided to face each other with a dielectric in the thickness direction of the dielectric layer 6, and the inner layer wiring 10a and the inner layer wiring 11a overlap when the package 2 is viewed from above. Is arranged.

  Further, as shown in FIG. 3, the inner layer wiring 10a and the inner layer wiring 11a have a cross-sectional shape orthogonal to the extending direction thereof, that is, a cross-sectional shape of a plane parallel to the paper surface in FIG. The inner layer wiring 10a and the inner layer wiring 11a are arranged in parallel so that the long sides of the respective rectangles face each other. By facing in this way, the inner layer wiring 10a and the inner layer wiring 11a face each other in the width direction, and stronger coupling can be obtained during signal transmission.

  In the high-frequency signal transmitted through the inner layer line pair 7, the voltage or current is reversed in phase with each other and the difference is consumed by the load, so that the supply of voltage or current to the load can be doubled. When the same external noise is applied to each of them, the applied external noise is canceled by taking a voltage or current difference at the load.

  In order to pull out the inner layer line 7a to the connection pad 4, a vertical wiring portion extending in the thickness direction by the land 10b and the through conductor 10c and connected to the connection pad 4 is provided at the end of the inner layer wiring 10a. Further, in order to pull out the inner layer line 7b to the connection pad 4, a vertical wiring portion that extends in the thickness direction by the land 11b and the through conductor 11c and is connected to the connection pad 4 is provided at the end of the inner layer wiring 11a.

  The connection pad 4 includes a connection pad 4a connected to the inner layer wiring 10a via the land 10b and the through conductor 10c, and a connection pad 4b connected to the inner layer wiring 11a via the land 11b and the through conductor 11c. This is a second mounting pad pair.

  In order for the inner layer line pair 7 to realize a broadside coupled strip line, the inner layer wiring 10a and the inner layer wiring 11a are provided in wiring layers having different heights in the dielectric layer 6, and the connection pad 4 10a and the inner layer wiring 11a are provided side by side in the extending direction.

  The connection pad 4 constitutes a part of a connection pad group provided on the periphery of the main surface 6 a of the dielectric layer 6 facing the resin substrate 8. Since it is provided side by side in the extending direction of the inner layer wiring 10a and the inner layer wiring 11a as described above, the connection pad group provided in the dielectric layer 6 is composed of the outermost peripheral pad and the second row of pads from the outermost peripheral. Is done. Here, the outermost pad corresponds to the connection pad 4a, and the second row pad from the outermost periphery corresponds to the connection pad 4b.

  Such a configuration of the connection pad 4 is suitable for transmission of a high-frequency signal having a transmission signal frequency of 10 GHz or more.

  On the other hand, in the mounting board 3, a differential transmission wiring structure is constituted by the surface layer line pair 9 which is the first conductor pair.

  In the mounting board 3, connection pads 5 are provided on the main surface 8 a of the resin substrate 8 facing the main surface 6 a of the dielectric layer 6 of the package 2, and the connection pads 4 of the package 2 and the connection pads 5 of the mounting board 3 are provided. Are electrically connected by the solder balls 12, and a high-frequency signal transmitted through the inner layer line pair 7 of the package 2 is transmitted through the surface pads 9 through the connection pads 4 and 5 and the solder balls 12.

  In the surface layer pair 9, a surface layer line 9 a that is a first signal conductor and a surface layer line 9 b that is a second signal conductor are arranged in parallel on the main surface 8 a of the resin substrate 8 so as to be coupled to each other. Construct a microstrip line.

  Since the surface layer line 9a and the surface layer line 9b are provided on the main surface 8a of the resin substrate 8, the surface layer line 9a and the surface layer line 9b are the main surface of the resin substrate 8 until the surface layer line 9a is connected to the connection pad 5a. A high-frequency signal is differentially transmitted while extending in parallel on 8a and being coupled with each other in wiring thickness.

  As shown in FIG. 2, when the package 2 and the mounting board 3 are viewed from above, the surface layer line 9a, the inner layer line 7a, and the inner layer line 7b are arranged on the same straight line. Further, the connection pad 5a and the connection pad 5b are arranged on the same straight line. Also, the inner layer line pair 7, the surface layer line pair 9, and the connection pads 4, 5 are arranged so that the direction in which the surface layer line pair 9 extends from the connection pad 5 and the direction in which the inner layer line pair 7 extends from the connection pad 4 are opposite. And the package 2 and the mounting board 3 are connected.

  The connection pad 5 is provided on the main surface 8 a of the resin substrate 8, and the connection pad 5 a which is a first mounting pad provided at the end of the surface layer line 9 a of the surface layer line pair 9 and the surface layer of the surface layer line pair 9. This is a first mounting pad pair composed of connection pads 5b which are second mounting pads provided at the end of the line 9b.

  As shown in FIG. 2, the connection pad 5 includes a connection pad 5a and a connection pad 5b along the extending direction of the surface layer line 9a and the surface layer line 9b. In the present embodiment, the surface layer line 9a is linearly connected to the connection pad 5a without bending, and the center of the connection pad 5a and the center of the connection pad 5b are arranged on the extended line of the surface layer line 9a. It has been.

  When the surface layer line 9a and the surface layer line 9b are to be connected to the connection pad 5 provided as in the present embodiment, the surface layer line 9b is connected to the connection pad 5b with at least one bent portion. Is done.

  In the present invention, the surface layer line 9a and the surface layer line 9b are configured to have a juxtaposed region in which two wirings are juxtaposed and a connection region in which the two wires are connected to the connection pad 5a and the connection pad 5b, respectively. Is done.

  In the present embodiment, the juxtaposed conductor 16a and juxtaposed conductor 16b, which are juxtaposed regions, and the connecting conductor 17a and connecting conductor 17b, which are connecting regions, are provided with the boundary line 15 as a boundary.

  The parallel conductor 16a and the parallel conductor 16b are provided in parallel on the main surface 8a of the resin substrate 8 while maintaining a predetermined interval. The connecting conductor 17a is linearly connected to the connecting pad 5a along the extending direction of the juxtaposed conductor 16a without being bent. The connection conductor 17b has two bent portions 18 and 19, and further, in the vicinity of the boundary line 15, has a bent portion 20 with respect to the parallel conductor 16b and is connected to the connection pad 5b.

  The bent portion 20 to the bent portion 18 are connected by the straight portion 21, the bent portion 18 to the bent portion 19 are connected by the straight portion 22, and the connection pad 5 b is connected by the straight portion 23.

  The straight portion 21 is provided so that the extending direction forms an angle θ1 with respect to the extending direction of the parallel conductor 16b, and the straight portion 22 is provided so that the extending direction is parallel to the parallel conductor 16b. The straight portion 23 is provided such that the extending direction forms an angle θ2 with respect to the extending direction of the straight portion 22.

  In the wiring structure as in the present embodiment, the connection conductor 17b is connected to the connection pad 5b by setting the angle θ1 and the angle θ2 to the same angle with opposite signs. For example, θ1 = 45 ° and θ2 = −45 °.

  Thus, by providing the connection conductor 17a and the connection conductor 17b which are connection regions, the surface layer line 9a and the surface layer line 9b can be connected to the connection pad 5a and the connection pad 5b.

  Thereby, since the connection pad 5a and the connection pad 5b can be provided along the extending direction of the surface layer line 9a and the surface layer line 9b, good differential transmission is possible without increasing the wiring density.

  As described above, the surface layer line pair 9 has the differential transmission wiring structure in which the surface layer line 9a and the surface layer line 9b constitute a parallel microstrip line. The surface line 9b needs to be configured to be connectable.

  In order to configure the surface layer line pair 9 to be connectable, the surface layer line 9a and the surface layer line 9b may be provided without a conductor formed of a conductive material such as metal. For example, if a metal conductor or the like is interposed between the surface layer line 9a and the surface layer line 9b, the connection between the surface layer line 9a and the metal conductor, and the connection between the surface layer line 9b and the metal conductor become strong. The coupling between 9a and the surface layer line 9b is weakened, and the differential transmission characteristics are deteriorated.

  In order to configure the surface layer line pair 9 to be connectable, a dielectric is provided between the surface layer line 9a and the surface layer line 9b, and the surface layer line 9a and the surface layer line 9b are interposed with the dielectric interposed therebetween. You may comprise so that it may couple | bond together. Examples of the dielectric include ceramics used for the package 2, resin used for the mounting board 3, solder resist provided on the main surface 8 a of the resin substrate 8, and air.

  By filling the space between the surface layer line 9a and the surface layer line 9b with a dielectric other than air, it is preferable because a conductor can be avoided and unnecessary coupling can be suppressed.

  In order to configure the surface layer line pair 9 to be connectable, the surface layer line 9a and the surface layer line 9b may be directly opposed to each other without interposing other than an insulator between the surface layer line 9a and the surface layer line 9b.

FIG. 5 is a plan view of a connection structure according to the second embodiment of the present invention.
Since the present embodiment is different from the first embodiment only in the configuration of the surface layer line pair 9, the configuration of the surface layer line pair 9 will be described below, and the description of the other configurations will be omitted.

  As in the first embodiment, the surface layer line pair 9 includes a surface layer line 9a and a surface layer line 9b arranged in parallel on the main surface 8a of the resin substrate 8 so as to be coupled to each other, thereby forming a parallel microstrip line.

  Since the surface layer line 9a and the surface layer line 9b are provided on the main surface 8a of the resin substrate 8, the surface layer line 9a and the surface layer line 9b are the main surface of the resin substrate 8 until the surface layer line 9a is connected to the connection pad 5a. A high-frequency signal is differentially transmitted while extending in parallel on 8a and being coupled with each other in wiring thickness.

  As shown in FIG. 5, when the package 2 and the mounting board 3 are viewed from above, the surface layer line 9a, the inner layer line 7a, and the inner layer line 7b are arranged on the same straight line, and the connection pad 5a and the connection pad 5b Are arranged on the same straight line.

  The connection pad 5 includes a connection pad 5 a provided at an end portion of the surface layer line 9 a of the surface layer line pair 9 and a connection pad 5 b provided at an end portion of the surface layer line 9 b of the surface layer line pair 9.

  As shown in FIG. 5, the connection pad 5 includes a connection pad 5a and a connection pad 5b along the extending direction of the surface layer line 9a and the surface layer line 9b.

  In the present embodiment, parallel conductors 16a and 16b that are parallel regions and a connection conductor 17b that is a connection region are provided with a boundary line 15 as a boundary.

  The difference of the configuration of the present embodiment from the first embodiment is that the connection conductor 17b has one bent portion and is connected to the connection pad 5b. In addition, a boundary line 15 between the juxtaposed region and the connection region exists at a portion where the surface layer line 9a and the connection pad 5a are connected. Therefore, since the parallel conductor 16a is directly connected to the connection pad 5a, the parallel conductor 16a also serves as the connection conductor 17a.

  The parallel conductor 16a and the parallel conductor 16b are provided in parallel on the main surface 8a of the resin substrate 8 while maintaining a predetermined interval. As described above, the parallel conductor 16a is directly connected to the connection pad 5a as the connection conductor 17a. The connecting conductor 17b has one bent portion 24 and is connected to the juxtaposed conductor 16b without being bent at the connecting portion 25 in the vicinity of the boundary line 15.

  The bent portion 24 to the bent portion 24 are connected by the straight portion 26, and the bent portion 24 connection pad 5 b is connected by the straight portion 27.

  The straight portion 26 is provided such that the extending direction thereof coincides with the parallel conductor 16b, and the straight portion 27 forms an angle θ3 with respect to the extending direction of the parallel conductor 16b and the straight portion 26. It is provided as follows. For example, θ3 = 45 °.

  Thus, the surface conductor 9a and the surface conductor 9b can be connected to the connection pad 5a and the connection pad 5b by the parallel conductor 16a and the connection conductor 17b.

  Thereby, since the connection pad 5a and the connection pad 5b can be provided along the extending direction of the surface layer line 9a and the surface layer line 9b, good differential transmission is possible without increasing the wiring density. In the present embodiment, since there is one bent portion, the differential transmission characteristics are further improved.

FIG. 6 is a plan view of a connection structure according to a third embodiment of the present invention.
Since the present embodiment is different from the first and second embodiments described above only in the configuration of the surface line pair 9, the configuration of the surface line pair 9 will be described below, and the description of the other configurations will be omitted. To do.

  As in the first and second embodiments, the surface layer line pair 9 includes a surface layer line 9a and a surface layer line 9b arranged on the main surface 8a of the resin substrate 8 so as to be coupled to each other, thereby forming a parallel microstrip line. To do.

  Since the surface layer line 9a and the surface layer line 9b are provided on the main surface 8a of the resin substrate 8, the surface layer line 9a and the surface layer line 9b are the main surface of the resin substrate 8 until the surface layer line 9a is connected to the connection pad 5a. A high-frequency signal is differentially transmitted while extending in parallel on 8a and being coupled with each other in wiring thickness.

  As shown in FIG. 6, when the package 2 and the mounting board 3 are viewed from above, the surface layer line 9a, the inner layer line 7a, and the inner layer line 7b are arranged on the same straight line, and the connection pad 5a, the connection pad 5b, Are arranged on the same straight line.

  The connection pad 5 includes a connection pad 5 a provided at an end portion of the surface layer line 9 a of the surface layer line pair 9 and a connection pad 5 b provided at an end portion of the surface layer line 9 b of the surface layer line pair 9.

  As shown in FIG. 6, the connection pad 5 includes a connection pad 5a and a connection pad 5b along the extending direction of the surface layer line 9a and the surface layer line 9b.

  In the present embodiment, parallel conductors 16a and 16b that are parallel regions and a connection conductor 17b that is a connection region are provided with a boundary line 15 as a boundary.

  The difference of the configuration of the present embodiment from the first and second embodiments is that the connection conductor 17b has one bent portion and is connected to the connection pad 5b. In the connection region, the end of the juxtaposed region That is, the connection is made so that the wiring length from the portion to the connection pad 5 is the shortest. In addition, a boundary line 15 between the juxtaposed region and the connection region exists at a portion where the surface layer line 9a and the connection pad 5a are connected. Therefore, since the parallel conductor 16a is directly connected to the connection pad 5a, the parallel conductor 16a also serves as the connection conductor 17a.

  The parallel conductor 16a and the parallel conductor 16b are provided in parallel on the main surface 8a of the resin substrate 8 while maintaining a predetermined interval. As described above, the parallel conductor 16a is directly connected to the connection pad 5a as the connection conductor 17a. The connecting conductor 17 b has one bent portion 28 and is connected to the juxtaposed conductor 16 b without being bent at the connecting portion 29 in the vicinity of the boundary line 15.

  The bent portion 28 to the bent portion 28 are connected by the straight portion 30, and the bent portion 28 connection pad 5 b is connected by the straight portion 31.

  The straight line portion 30 is provided such that the extending direction thereof coincides with the parallel conductor 16b, and the straight line portion 31 forms an angle θ4 with respect to the extending direction of the parallel conductor 16b and the straight line portion 26. It is provided as follows.

  At this time, in the connection region, it is preferable that the wiring length from the end of the juxtaposed region to the connection pad 5, that is, the sum of the wiring lengths of the straight portion 30 and the straight portion 31 is the shortest. By making the wiring length the shortest, the angle θ4 with respect to the extending direction of the linear portion 26 can be reduced. By reducing the angle θ4, it is possible to suppress the deterioration of the transmission characteristics in the bent portion 28.

  The angle θ4 can be reduced by shortening the length of the straight line portion 30 and narrowing the distance between the connection pad 5a and the straight line portion 31. Although the space | interval of the connection pad 5a and the linear part 31 is decided by manufacturing conditions etc., it is about 20-100 micrometers, for example.

In the present embodiment, for example, θ4 = 26.6 °.
Thus, the surface conductor 9a and the surface conductor 9b can be connected to the connection pad 5a and the connection pad 5b by the parallel conductor 16a and the connection conductor 17b.

  Thereby, since the connection pad 5a and the connection pad 5b can be provided along the extending direction of the surface layer line 9a and the surface layer line 9b, good differential transmission is possible without increasing the wiring density. In the present embodiment, since there is one bent portion and the angle θ4 can be further reduced, the differential transmission characteristic is further improved.

As the dielectric layer 6 of the package 2, an inorganic dielectric such as ceramics or an organic dielectric such as resin can be used as long as a multilayer wiring structure can be realized therein. For example, alumina _(Al 2 _{O 3)} ceramics, mullite _{(3Al 2 O 3 · 2SiO 2} ) ceramics or inorganic materials as glass ceramics, polytetrafluoroethylene resin (polytetrafluoroethylene; PTFE), tetrafluoroethylene - ethylene copolymer Polymer resin (ethylene-tetrafluoroethylene copolymer; ETFE), fluororesin such as tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer resin (perfluoroalkoxyalkane; PFA), glass epoxy resin, polyphenylene ether (PPE) resin A resin material such as liquid crystal polyester (LCP) or polyimide (PI) is used. The shape and dimensions of the dielectric layer 6 are appropriately set according to the application, but the thickness is particularly set according to the frequency of the transmission signal and the impedance design.

  The material of the inner line pair 7 is made of a metal conductor layer suitable for high-speed signal transmission. For example, when ceramic is used as the material of the dielectric layer 6, copper, molybdenum-manganese, tungsten, or Nickel plating and gold plating on molybdenum-manganese metallization, nickel plating and gold plating on tungsten metallization, nickel-chromium alloy and gold plating on tantalum nitride, or A nickel-chromium alloy having platinum or gold plated thereon is used, and as a manufacturing method, for example, a thick film printing method or various thin film forming methods, a plating method, and the like are used. The width and thickness of each conductor wiring are set according to the frequency and impedance design of the transmission signal.

  Although the resin board 8 is mainly used for the mounting board 3 as in the present embodiment, the present invention is not limited to this, and similarly to the package 2, an inorganic dielectric such as ceramics or an organic dielectric such as resin can be used.

  In this embodiment, a solder ball is used as a conductive member for electrically connecting the connection pads 4 and 5. However, any conductive member suitable for high-speed signal transmission can be used. For example, a metal member such as gold, silver, or copper is used, and the form thereof is not limited to a ball, and may be a columnar shape, a bump shape, or the like.

  The package 2 of the present embodiment is produced as follows, for example. When the dielectric layer 6 is made of, for example, alumina ceramic, first, a green sheet of alumina ceramic is prepared, and a predetermined punching process is performed on the green sheet to form through holes for providing the through conductors 10c and 11c. Next, a conductive paste such as tungsten and molybdenum is filled into the through-holes by screen printing, and the conductor wiring, that is, the pattern of the inner layer wiring 10a and the inner layer wiring 11a, and the land 10b and the land 11b are placed at predetermined positions on the green sheet. Apply printing. Next, the green sheets on which the patterns are formed are stacked and fired at about 1600 ° C.

  The mounting board 3 is prepared by preparing a copper-clad substrate in which a copper foil is affixed to the surface of a glass epoxy substrate such as FR-4, and by using a known patterning technique such as etching the copper foil to form the surface line pairs 9 and connection pads. 5 is formed into a pattern.

  Solder resists 13 and 14 are provided on the main surface 6a where the connection pads 4 of the dielectric layer 6 are formed and the main surface 8a where the connection pads 5 of the resin substrate 8 are formed, respectively.

  Solder balls 12 are placed on the connection pads 5 of the mounting board 3, and the connection pads 4 of the package 2 are aligned with the corresponding connection pads 5, and the connection pads 4 and 5 are soldered to the solder balls by ultrasonic vibration, reflow, or the like. 12 is joined.

It is a perspective view which shows the connection structure 1 which is the 1st Embodiment of this invention. 1 is a plan view showing a connection structure 1. FIG. 1 is a front view showing a connection structure 1. FIG. 1 is a side view showing a connection structure 1. FIG. It is a top view which shows the connection structure 1 which is the 2nd Embodiment of this invention. It is a perspective view which shows the connection structure 1 which is the 3rd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Connection structure 2 Package 3 Mounting board 4 Connection pad 7 Inner layer line pair 9 Surface layer line pair 9a, 9b Surface layer line 10a, 11a Inner layer wiring 16a, 16b Parallel conductor 17a, 17b Connection conductor

Claims (8)

A first dielectric substrate, and a first conductor pair composed of a first signal conductor and a second signal conductor arranged in parallel to each other on the main surface of the first dielectric substrate; A first pair of mounting pads comprising a first mounting pad provided at an end of the first signal conductor and a second mounting pad provided at an end of the second signal conductor. A first wiring board having:
A second dielectric substrate facing the first dielectric substrate; and a third signal conductor and a fourth signal conductor provided on the inner layer of the second dielectric substrate so as to be coupled to each other. A second wiring board having a second conductor pair and a second mounting pad pair for connecting the second conductor pair to the first mounting pad pair;
A connection structure for differential transmission,
In the first mounting pad pair, the first mounting pad and the second mounting pad are provided along the extending direction of the first conductor pair,
The first conductor pair includes a juxtaposed region in which the first signal conductor and the second signal conductor are juxtaposed, the first signal conductor, and the second signal conductor. Each having a connection region connected to the first mounting pad and the second mounting pad.   The differential transmission connection structure according to claim 1, wherein the first conductor pair is provided without a conductor between the first signal conductor and the second signal conductor.   The differential transmission connection structure according to claim 1, wherein the first conductor pair is provided with a dielectric between the first signal conductor and the second signal conductor.   2. The differential transmission connection structure according to claim 1, wherein the first conductor pair is provided between the first signal conductor and the second signal conductor without interposing an insulator.   In the connection region of the first conductor pair, the first signal conductor and the second signal conductor are shortest from the end of the juxtaposed region to the first mounting pad pair. The connection structure for differential transmission according to any one of claims 1 to 4, wherein the connection structure is connected to.   6. The first conductor pair according to claim 1, wherein the third signal conductor and the fourth signal conductor are arranged in parallel in the thickness direction of the second dielectric substrate. Connection structure for differential transmission as described in 1.   In the second conductor pair, the third signal conductor and the fourth signal conductor have a rectangular cross-sectional shape orthogonal to the extending direction, and the long sides of the respective rectangles face each other. The connection structure for differential transmission according to claim 6 arranged in parallel. The frequency of the electrical signal transmitted through the first conductor pair and the second conductor pair is 10 GHz or more;
The second mounting pad pair includes the outermost pad and the second row from the outermost periphery in a pad group provided on the periphery of the surface of the second dielectric substrate facing the first dielectric substrate. The connection structure for differential transmission according to any one of claims 1 to 7.

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