JP2010087037A - Multilayer wiring board for differential transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a multilayer wiring board for differential transmission, which attains the excellent differential transmission by matching a differential impedance in an inter-layer connection conductor. <P>SOLUTION: An inter-center distance between a penetration conductor 10c and a penetration conductor 11c is made to be different from the inter-center distance between a connection pad 4a and a connection pad 4b. When the differential impedance is higher than the differential impedances of inner layer wiring 11a and inner layer wiring 10a in the case where the inter-center distance between the penetration conductor 10c and the penetration conductor 11c is equal to the inter-center distance between the connection pad 4a and the connection pad 4b, the inter-center distance between the penetration conductor 10c and the penetration conductor 11c is made to be smaller than the inter-center distance between the connection pad 4a and the connection pad 4b. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a multilayer wiring board for differential transmission suitable for mounting a semiconductor integrated circuit such as a semiconductor element and an optical semiconductor element that operate 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, for example, 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 coupling strip line is connected to the surface mounting pad via the interlayer connection conductor in the thickness direction connecting the wiring layers such as via conductors.

  At this time, the interlayer connection conductor connects each end of the pair of wiring conductors constituting the differential transmission wiring structure and the mounting pad. The mounting pads are provided at a pitch (center distance) that matches the mounting pads on the mounting substrate side. The interlayer connection conductor is provided so that the center of the interlayer connection conductor is aligned with the center position of the mounting pad (see Patent Document 1).

JP-A-8-46136

  The differential impedance of the pair of interlayer connection conductors connected to the broadside coupling strip line is determined by the coupling between the interlayer connection conductors. The differential impedance of the pair of interlayer connection conductors is determined by the size of the conductor, the dielectric constant of the dielectric layer, the distance between the conductors, and the like.

  If the distance between the conductors is determined by the pitch of the mounting pads as in the conventional case, the differential impedance of the pair of interlayer connection conductors cannot be matched with the differential impedance of the pair of wiring conductors. There is a problem that differential signal reflection occurs at the connection portion with the connection conductor and the transmission characteristics deteriorate.

  An object of the present invention is to provide a differential transmission multilayer wiring board capable of matching differential impedances in interlayer connection conductors and enabling good differential transmission.

  The present invention provides a dielectric substrate, a wiring conductor pair including a first signal conductor and a second signal conductor provided on the inner layer of the dielectric substrate so as to be coupled to each other, and a main surface of the dielectric substrate A mounting pad pair including a first mounting pad connected to the first signal conductor and a second mounting pad connected to the second signal conductor, and a dielectric substrate. A first interlayer connecting conductor for connecting the first signal conductor and the first mounting pad in the thickness direction; and a second signal conductor and a second mounting pad in the thickness direction of the dielectric substrate. A multilayer wiring board for differential transmission having a pair of interlayer connection conductors including a second interlayer connection conductor to be connected, the distance between the centers of the first mounting pad and the second mounting pad; The distance between the centers of the first interlayer connection conductor and the second interlayer connection conductor is different. Sea urchin is a differential transmission multilayer wiring board constructed.

  According to the present invention, in the wiring conductor pair, the first signal conductor and the second signal conductor are arranged in parallel in the thickness direction of the dielectric substrate.

  Further, according to the present invention, in the wiring conductor pair, the first signal conductor and the second signal conductor have a rectangular cross-sectional shape orthogonal to the extending direction, and the long sides of the respective rectangles are It is arranged side by side so as to face each other.

In the invention, it is preferable that the dielectric substrate includes a first dielectric layer and a second dielectric layer and a third dielectric layer that are stacked so as to sandwich the first dielectric layer. ,
The first signal conductor is provided between the first dielectric layer and the second dielectric layer;
The second signal conductor is provided between the first dielectric layer and the third dielectric layer;
The first interlayer connection conductor is provided so as to penetrate the second dielectric layer;
The second interlayer connection conductor is provided so as to penetrate the first dielectric layer and the second dielectric layer.

  According to the present invention, in the wiring conductor pair, the first signal conductor and the second signal conductor are arranged in parallel in a direction parallel to the main surface of the dielectric substrate.

  According to the present invention, the inner layer of the dielectric substrate is provided with a pair of wiring conductors composed of a first signal conductor and a second signal conductor that are provided so as to be coupled to each other. A mounting pad pair including a first mounting pad connected to the first signal conductor and a second mounting pad connected to the second signal conductor is provided. Furthermore, a first interlayer connection conductor connecting the first signal conductor and the first mounting pad in the thickness direction of the dielectric substrate to the inner layer of the dielectric substrate, and a second layer in the thickness direction of the dielectric substrate. An interlayer connection conductor pair including a second interlayer connection conductor connecting the signal conductor and the second mounting pad; and a center-to-center distance between the first mounting pad and the second mounting pad; The distance between the centers of the first interlayer connection conductor and the second interlayer connection conductor is different.

  As a result, the differential impedance of the interlayer connection conductor pair can be matched with the differential impedance of the wiring conductor pair, so that reflection of the differential signal at the connection portion between the wiring conductor and the interlayer connection conductor is suppressed, and a good result is obtained. Differential 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 package 2 according to the first embodiment of the present invention. FIG. 2 is a plan view showing the package 2. FIG. 3 is a front view showing the package 2. FIG. 4 is a side view showing the package 2.

  FIG. 1 shows a state where a package 2 which is a multilayer wiring board for differential transmission is mounted on a mounting board 3. A connection pad 4 provided on the package 2 and a connection pad 5 provided on the mounting board 3 are shown in FIG. The solder balls 12 are electrically connected and mounted.

  The package 2 has a dielectric substrate 6 which is a dielectric substrate, an inner layer line pair 7 and a connection pad 4, and the mounting board 3 has a resin substrate 8, a surface layer line pair 9 and a connection pad 5. .

  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 that is a first signal conductor, a land 11b, and a through conductor 11c that is a first interlayer connection conductor. The inner layer line 7a is further an inner layer that is a second signal conductor. The wiring 10a, the land 10b, and the through conductor 10c as the second interlayer connection conductor.

  The inner layer line pair 7 is a differential transmission wiring pair provided on the inner layer of the dielectric substrate 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 substrate 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 substrate 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 mounting pad pair.

  The dielectric substrate 6 includes a second dielectric layer 6a, a second dielectric layer 6b, and a third dielectric layer 6c sandwiching the first dielectric layer 6a. The dielectric layer 6b and the third dielectric layer 6c are provided, and the second dielectric layer 6b, the first dielectric layer 6a, and the third dielectric layer 6c are arranged in this order from the side facing the mounting board 3. Laminated.

  The inner layer wiring 11a is provided between the first dielectric layer 6a and the second dielectric layer 6b, and the inner layer wiring 10a is formed between the first dielectric layer 6a and the third dielectric layer 6c. Provided.

  The through conductor 11c penetrates the second dielectric layer 6b and connects to the connection pad 4b. The through conductor 10c penetrates the first dielectric layer 6a and the second dielectric layer 6b and connects to the connection pad 4a. Connect to.

  In the conventional technique, the distance between the centers of the through conductor 10c and the through conductor 11c is the same as the distance between the centers of the connection pad 4a and the connection pad 4b, and the through conductor 10c and the through conductor 11c are connected to the connection pad 4a and the connection pad. It will be connected to the center of 4b. However, the distance between the centers of the connection pad 4a and the connection pad 4b is merely matched with the distance between the centers of the connection pads 5 of the mounting board 3, and transmission characteristics are hardly considered. Therefore, when the distance between the centers of the through conductor 10c and the through conductor 11c is adjusted to the distance between the centers of the connection pad 4a and the connection pad 4b, the differential impedance of the through conductor 10c and the through conductor 11c is the difference between the inner layer wiring 11a and the inner layer wiring 10a. It will deviate from the differential impedance of the wiring conductor pair.

  In the present invention, the distance between the centers of the through conductor 10c and the through conductor 11c is different from the distance between the centers of the connection pad 4a and the connection pad 4b.

  In the present embodiment, for example, the distance between the centers of the through conductor 10c and the through conductor 11c is configured to be smaller than the distance between the centers of the connection pad 4a and the connection pad 4b. The differential impedance has a predetermined design value for the differential transmission structure, and the distance between the centers of the through conductor 10c and the through conductor 11c is adjusted in order to match the predetermined design value.

  In the case of the broadside coupled strip line as in the present embodiment, the inner layer wiring 11a and the inner layer wiring 10a are disposed between different dielectric layers, and therefore the distance between the centers of the through conductor 10c and the through conductor 11c is the inner layer. It can be easily adjusted by changing the length of the wiring 11a and the inner layer wiring 10a.

  In the present embodiment, the distance between the centers of the through conductor 10c and the through conductor 11c is configured to be smaller than the distance between the centers of the connection pad 4a and the connection pad 4b. The distance between the centers of the through conductors 11c may be larger than the distance between the centers of the connection pads 4a and 4b, and the differential impedance between the through conductors 10c and the through conductors 11c is set to a predetermined value. If alignment is possible, the distance between the centers of the through conductors 10c and the through conductors 11c may be different from the distance between the centers of the connection pads 4a and the connection pads 4b.

  When the distance between the centers of the through conductor 10c and the through conductor 11c is the same as the distance between the centers of the connection pad 4a and the connection pad 4b, the differential impedance is higher than the differential impedance of the inner layer wiring 11a and the inner layer wiring 10a. For this, the distance between the centers of the through conductor 10c and the through conductor 11c may be made smaller than the distance between the centers of the connection pad 4a and the connection pad 4b, and the distance between the centers of the through conductor 10c and the through conductor 11c may be set to the connection pad 4a. When the operating impedance is lower than the differential impedance between the inner layer wiring 11a and the inner layer wiring 10a, the distance between the centers of the through conductor 10c and the through conductor 11c is connected. What is necessary is just to make it larger than the center distance of the pad 4a and the connection pad 4b.

  In this way, by matching the differential impedance of the through conductor 10c and the through conductor 11c with the differential impedance of the inner layer wiring 11a and the inner layer wiring 10a, the inner layer wiring 11a, the inner layer wiring 10a, the through conductor 10c, and the through conductor Thus, the differential signal reflection at the connection portion with the terminal 11 is suppressed, and good differential transmission is possible.

  Even when the distance between the centers of the through conductor 10c and the through conductor 11c is larger than the distance between the centers of the connection pad 4a and the connection pad 4b, it is easy to change the lengths of the inner layer wiring 11a and the inner layer wiring 10a. realizable.

  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. The connection pad 4a and the connection pad 4b are provided side by side in the extending direction of the inner layer wiring 10a and the inner layer wiring 11a. Of the connection pad group provided in the dielectric layer 6, the outermost pad and the second row from the outermost row It consists of a pad. 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 configured by the surface layer line pair 9.
In the mounting board 3, the 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 substrate 6 of the package 2. 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 line pair 9, the surface layer line 9a and the surface layer line 9b are 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. 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 is provided on the end of the surface layer line 9 b of the surface layer line pair 9 and the connection pad 5 a provided on the end part of the surface layer line 9 a of the surface layer line pair 9. The connection pad 5b.

  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.

  The surface layer line 9b maintains the same length as the surface layer line 9a in the line parallel portion until the surface layer line 9a is connected to the connection pad 5a, but the connection pad is connected to the surface layer line 9a where the surface layer line 9a is connected to the connection pad 5a. Further extending to the connection pad 5b provided at the back of 5a is connected. Since the surface layer line 9b is provided on the main surface 8a of the resin substrate 8, in order to connect to the connection pad 5b, the vicinity of the connection pad 5a is arranged around the connection pad 5a. .

Next, a second embodiment of the present invention will be described.
FIG. 5 is a diagram illustrating a package 2 that is a first aspect of the second embodiment. FIG. 5A shows a plan view of the package 2, and FIG. 5B shows a front view of the package 2.

  In the first embodiment, the inner layer line 7a and the inner layer line 7b of the inner layer line pair 7 are broad-side coupled strip lines arranged in parallel in the thickness direction of the dielectric substrate 6, but in this embodiment, the inner layer line Inner layer line 15a and inner layer line 15b constituting pair 15 are juxtaposed in dielectric substrate 6 so as to be coupled to each other, thereby forming a parallel microstrip line.

  The inner layer line 15a includes an inner layer wiring 16a that is a first signal conductor, a land 16b, and a through conductor 16c that is a first interlayer connection conductor. The inner layer line 15b is an inner layer wiring 17a that is a second signal conductor. And a land 17b and a through conductor 17c as a second interlayer connection conductor.

  The dielectric substrate 6 is composed of three layers of a first dielectric layer 6a, a second dielectric layer 6b, and a third dielectric layer 6c. The inner layer wiring 16a and the inner layer wiring 17a It is provided between the dielectric layer 6a and the third dielectric layer 6c.

  The through conductor 16c and the through conductor 17c penetrate the first dielectric layer 6a and the second dielectric layer 6b and connect to the connection pad 4a and the connection pad 4b.

  In the first mode shown in FIG. 5, the distance between the centers of the through conductor 16c and the through conductor 17c is made smaller than the distance between the centers of the inner layer wiring 16a and the inner layer wiring 17a, and the distance between the centers of the through conductor 16c and the through conductor 17c is reduced. The distance between the centers of the connection pad 4a and the connection pad 4b is made different.

  In the case of a parallel microstrip line as in the present embodiment, since the inner layer wiring 16a and the inner layer wiring 17a are disposed between the same dielectric layers, the distance between the centers of the through conductor 16c and the through conductor 17c is the inner layer wiring. Adjustment can be made by bending 16a at a portion connecting to the land 16b and bending the inner layer wiring 17a at a portion connecting to the land 17c.

  In this embodiment, the inner layer wiring 16a and the inner layer wiring 17a are bent so as to approach each other and are connected to the land 16b and the land 17b having a predetermined center distance, and the through conductor 16c and the through conductor 17c are connected at the same center distance. Connect to the connection pad 4a and the connection pad 4b. At this time, the distance between the centers of the through conductor 16c and the through conductor 17c is smaller than the distance between the centers of the connection pad 4a and the connection pad 4b.

  FIG. 6 is a diagram illustrating a package 2 that is a second aspect of the second embodiment. FIG. 6A shows a plan view of the package 2, and FIG. 6B shows a front view of the package 2.

  In the second mode shown in FIG. 6, the distance between the centers of the through conductor 16c and the through conductor 17c is made larger than the distance between the centers of the inner layer wiring 16a and the inner layer wiring 17a, and the distance between the centers of the through conductor 16c and the through conductor 17c is set. The distance between the centers of the connection pad 4a and the connection pad 4b is made different.

  In the case of a parallel microstrip line as in the present embodiment, since the inner layer wiring 16a and the inner layer wiring 17a are disposed between the same dielectric layers, the distance between the centers of the through conductor 16c and the through conductor 17c is the inner layer wiring. Adjustment can be made by bending 16a at a portion connecting to the land 16b and bending the inner layer wiring 17a at a portion connecting to the land 17c.

  In this embodiment, the inner layer wiring 16a and the inner layer wiring 17a are bent so as to be separated from each other and connected to the land 16b and the land 17b having a predetermined center distance, and the through conductor 16c and the through conductor 17c are connected at the same center distance. Connect to the connection pad 4a and the connection pad 4b. At this time, the distance between the centers of the through conductor 16c and the through conductor 17c is smaller than the distance between the centers of the connection pad 4a and the connection pad 4b.

  FIG. 7 is a diagram illustrating a package 2 that is a third aspect of the second embodiment. FIG. 7A shows a plan view of the package 2, and FIG. 7B shows a front view of the package 2.

  In the third mode shown in FIG. 7, the distance between the centers of the inner layer wiring 16a and the inner layer wiring 17a is the same as the distance between the centers of the through conductor 16c and the through conductor 17c, and the distance between the centers of the through conductor 16c and the through conductor 17c is the same. The distance between the centers of the connection pad 4a and the connection pad 4b is made different.

  If the differential impedance of the inner layer wiring 16a and the inner layer wiring 17a and the differential impedance of the through conductor 16c and the through conductor 17c are matched, the distance between the centers of the inner layer wiring 16a and the inner layer wiring 17a, the through conductor 16c, and the through conductor 17c. May have the same center-to-center distance. In such a case, if the distance between the centers of the inner layer wiring 16a and the inner layer wiring 17a is different from the distance between the centers of the connection pad 4a and the connection pad 4b, the distance between the centers of the through conductor 16c and the through conductor 17c is This is different from the center-to-center distance between the pad 4a and the connection pad 4b.

  In this embodiment, the inner layer wiring 16a and the inner layer wiring 17a are connected to the land 16b and the land 17b having the same center distance while maintaining the same center distance, and the through conductor 16c and the through conductor 17c are connected at the same center distance. Connect to the connection pad 4a and the connection pad 4b. At this time, the distance between the centers of the through conductor 16c and the through conductor 17c is smaller than the distance between the centers of the connection pad 4a and the connection pad 4b.

  In the present embodiment, as in the first embodiment, the distance between the centers of the through conductors 16c and the through conductors 17c is configured to be smaller than the distance between the centers of the connection pads 4a and the connection pads 4b. However, the distance between the centers of the through conductor 16c and the through conductor 17c may be larger than the distance between the centers of the connection pad 4a and the connection pad 4b. The differential between the through conductor 16c and the through conductor 17c may be used. As long as the impedance can be matched to a predetermined value, the distance between the centers of the through conductor 16c and the through conductor 17c may be different from the distance between the centers of the connection pad 4a and the connection pad 4b.

  When the operating impedance is higher than the differential impedance between the inner layer wiring 16a and the inner layer wiring 17a when the distance between the centers of the through conductor 16c and the through conductor 17c is the same as the center distance between the connection pad 4a and the connection pad 4b. The distance between the centers of the through conductor 16c and the through conductor 17c may be made smaller than the distance between the centers of the connection pad 4a and the connection pad 4b, and the distance between the centers of the through conductor 16c and the through conductor 17c may be reduced with the connection pad 4a. If the operating impedance is lower than the differential impedance between the inner layer wiring 16a and the inner layer wiring 17a when the distance between the centers of the connection pads 4b is the same, the distance between the centers of the through conductor 16c and the through conductor 17c is determined as the connection pad. What is necessary is just to make it larger than the distance between the centers of 4a and the connection pad 4b.

As the dielectric substrate 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 substrate 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 layer 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 substrate 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.

  For example, the package 2 of the first embodiment is manufactured as follows. When the dielectric substrate 6 is made of alumina ceramic, for example, 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-bonded substrate in which a copper foil is attached 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 pair 9 and the connection pad 5. The pattern is formed.

  Solder resists 13 and 14 are provided on the main surface 6a of the dielectric substrate 6 on which the connection pads 4 are formed and the main surface 8a of the resin substrate 8 on which the connection pads 5 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 package 2 which is the 1st Embodiment of this invention. 3 is a plan view showing a package 2. FIG. 3 is a front view showing a package 2. FIG. 3 is a side view showing a package 2. FIG. It is a figure which shows the package 2 which is the 1st aspect of 2nd Embodiment. It is a figure which shows the package 2 which is the 2nd aspect of 2nd Embodiment. It is a figure which shows the package 2 which is the 3rd aspect of 2nd Embodiment.

Explanation of symbols

2 Package 3 Mounting board 4, 5 Connection pad 7 Inner layer line pair 9 Surface layer line pair 9a, 9b Surface layer line 10a, 11a, 16a, 17a Inner layer wiring 10b, 11b, 16b, 17b Land 10c, 11c, 16c, 17c Through conductor

Claims (5)

A dielectric substrate;
A pair of wiring conductors composed of a first signal conductor and a second signal conductor provided on the inner layer of the dielectric substrate so as to be coupled to each other;
A mounting pad provided on the main surface of the dielectric substrate and comprising a first mounting pad connected to the first signal conductor and a second mounting pad connected to the second signal conductor Vs.
A first interlayer connecting conductor connecting the first signal conductor and the first mounting pad in the thickness direction of the dielectric substrate; and a second signal conductor and second mounting in the thickness direction of the dielectric substrate. An interlayer connection conductor pair composed of a second interlayer connection conductor connecting the pad for use;
A multi-layer wiring board for differential transmission having
A difference in which the distance between the centers of the first mounting pad and the second mounting pad is different from the distance between the centers of the first interlayer connection conductor and the second interlayer connection conductor. Multi-layer wiring board for dynamic transmission.   2. The multi-layer wiring board for differential transmission according to claim 1, wherein the wiring conductor pair includes the first signal conductor and the second signal conductor arranged in parallel in a thickness direction of the dielectric substrate.   The wiring conductor pairs are arranged in parallel so that the first signal conductor and the second signal conductor have a rectangular cross-sectional shape perpendicular to the extending direction, and the long sides of each rectangle face each other. The multilayer wiring board for differential transmission according to claim 1 or 2. The dielectric substrate includes a first dielectric layer, and a second dielectric layer and a third dielectric layer that are stacked so as to sandwich the first dielectric layer, respectively.
The first signal conductor is provided between the first dielectric layer and the second dielectric layer;
The second signal conductor is provided between the first dielectric layer and the third dielectric layer;
The first interlayer connection conductor is provided so as to penetrate the second dielectric layer;
4. The multi-layer wiring board for differential transmission according to claim 1, wherein the second interlayer connection conductor is provided so as to penetrate the first dielectric layer and the second dielectric layer.   5. The difference according to claim 1, wherein in the wiring conductor pair, the first signal conductor and the second signal conductor are arranged in parallel in a direction parallel to a main surface of the dielectric substrate. Multi-layer wiring board for dynamic transmission.

Images