JP4937957B2 - Wiring board and mounting structure thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To basically achieve size reduction by decreasing the number of external connection terminals, and to satisfy a demand to increase the number of external connection terminals even in the case that high integration is demanded. <P>SOLUTION: Disclosed are a wiring board 10 mounted with an electronic component 30 and a mounting structure including a body 40 with the wiring board 10 mounted thereon, wherein the wiring board 10 includes a pin 19 and a wiring layer 13 including a wiring pattern CP1 constituting a coil formed nearby the pin and the body 40 to be mounted, on the other hand, includes a socket 41 to which the pin 19 of the wiring board 10 is connected and a wiring layer 42 including a wiring pattern CP2 constituting a coil formed nearby the socket. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a wiring board and its mounting structure, and in particular, power supply and signal transmission between an electronic component such as a semiconductor element to be mounted and a mounted body (a connector such as a socket or a mother board having a land portion). The present invention relates to a technique useful for reducing the number of external connection terminals (pins, balls, etc.) used for mediation.

  In the following description, “wiring board” is also referred to as “semiconductor package” or simply “package” for convenience.

  In semiconductor packages such as BGA (Ball Grid Array), LGA (Land Grid Array), and PGA (Pin Grid Array), a build-up method is generally used on both sides of a core substrate serving as a base substrate. Then, the formation of the conductor pattern (wiring layer), the formation of the insulating layer, and the formation of the via hole in the insulating layer are sequentially repeated to form a multilayer wiring structure. Finally, the outermost wiring layer is covered with a protective film, and the protective film is required. A portion of the conductor pattern is exposed as a pad portion (land portion) by opening the portion. Further, in the case of BGA or PGA, balls or pins as external connection terminals are joined to the exposed pad portion (land portion).

  Such a semiconductor package has an electronic component such as an IC chip mounted on one surface, and is mounted on a mounted body such as a mother board via an external connection terminal provided on the other surface. That is, the chip and the mother board are electrically connected via the semiconductor package.

  For this reason, a signal pulled out from the IC chip mounted on the package to the outside of the package (motherboard) is taken out as an electric signal via the external connection terminal, the land portion, or the like. Similarly, electric power supplied from the outside of the package (mother board) is also supplied to the IC chip via an external connection terminal, a land portion, or the like.

  In the current technology, separate external connection terminals (pins, balls, etc.) are allocated and used for the power source and the signal in the semiconductor package.

As a technique related to such a conventional technique, for example, as described in Patent Document 1, in a pin connected to a substrate, a plurality of mutually separated conductor portions extending in the longitudinal direction of the pin, and the plurality of these There is a structure in which at least one conductor portion is formed inside the pin having a multiple cross-sectional structure including an intermediate portion having an electric resistance larger than that of the conductor portion interposed between the conductor portions. In addition, as described in Patent Document 2, in an electronic component in which an external connection terminal for connecting to an external circuit of a mounted body such as a wiring board is projected, the external connection terminal is mounted on a tip portion. A first conductor connected to an external circuit on the back side of the body, and a connecting portion inserted into the first conductor and projecting on the side surface are connected to the external circuit on the surface side of the mounted body There is one constituted by a second conductor and an insulator that insulates between the first and second conductors.
Japanese Patent No. 2540589 JP 2003-31751 A

  As described above, in the current technology, separate external connection terminals are used for the power supply and the signal, but when it is necessary to increase the number of inputs / outputs due to the demand for higher integration, There was a problem.

  That is, as the degree of integration increases, the number of inputs and outputs increases, while the power supply current also increases, and more external connection terminals (pins, balls, etc.) are required. In particular, in a semiconductor package (for example, a PGA type wiring board) on which an active IC chip such as an MPU (microprocessor unit) is mounted, the power supply current is remarkably increased, and the power required to supply the chip accordingly. A large number of external connection terminals (power supply pins) are also allocated, accounting for more than half of the number of external connection terminals (number of pins) of the entire package. That is, external connection terminals (signal pins) that can be used for signal input / output are limited to the remaining half or less.

  On the other hand, since the number of external connection terminals that can be incorporated into the package is limited due to the downsizing of the package, it is difficult to secure a sufficient number of external connection terminals.

  The present invention was created in view of the problems in the prior art, and it is basically necessary to reduce the number of external connection terminals, reduce the size, and increase the number of external connection terminals in accordance with the demand for higher integration. An object of the present invention is to provide a wiring board and a mounting structure thereof that can sufficiently meet the demand even if it occurs.

  In general, since the supplied power has a considerable magnitude (voltage / current level), it is necessary to directly transfer the supplied power in the form of an electric signal. However, for a signal such as a control signal or data, the magnitude (signal Since the level is relatively weak, it is not always necessary to transfer it directly in the form of an electric signal, and it is considered technically possible to transfer it to another signal form on the way. Therefore, in the present invention, the signal to be transferred is converted into a magnetic signal corresponding to the amount of current, and the converted magnetic signal is converted back to the original electric signal and transferred.

That is, in order to solve the above-described problems of the prior art, according to one aspect of the present invention, the invention is adapted to be mounted on a mounted body having a terminal connection portion and a wiring pattern constituting the first coil. A wiring board, wherein the wiring board is connected within a plane parallel to an external connection terminal connected to the terminal connection portion of the mounted body and a surface of the wiring board on which the external connection terminal is mounted. Magnetically coupled to the first coil at a position that surrounds the periphery of the external connection terminal in a state of being insulated from the external connection terminal when viewed in plan, and via a magnetic line of force generated by the current when the current flows And a wiring pattern constituting the second coil formed within the range to be provided.

  According to the configuration of the wiring board according to the present invention, the wiring board is mounted on the wiring board using the electrical connection between the external connection terminal (for example, pin) and the terminal connection portion (for example, socket) of the mounted body. While supplying necessary electric power to the electronic component, signals can be transmitted and received through a magnetic circuit including a coil formed on the wiring board and a coil formed on the mounted body. That is, since one external connection terminal can have two functions of power supply and signal transmission, the number of external connection terminals required for the wiring board can be reduced to half.

  Therefore, if the number of external connection terminals required for the wiring board is the same, the wiring board (package) according to the present invention can be downsized to approximately half the size of the conventional package. . Even when it is necessary to increase the number of inputs / outputs due to the demand for higher integration, it is difficult to secure a sufficient number of external connection terminals with the conventional technology due to restrictions on the miniaturization of the package. However, in the present invention, since two functions of power supply and signal transmission can be realized by using one external connection terminal, it is possible to sufficiently meet the demand for high integration.

According to another aspect of the present invention, the electronic device includes a wiring board on which an electronic component is mounted and a mounted body on which the wiring board is mounted. A wiring layer including a wiring pattern constituting a coil, wherein the wiring board is parallel to an external connection terminal connected to the terminal connection portion and a surface of the wiring board on which the external connection terminal is mounted. In a plane, when the wiring board is viewed from above, at a position surrounding the periphery of the external connection terminal in a state of being insulated from the external connection terminal, and via magnetic lines generated by the current when the current flows There is provided a wiring board mounting structure comprising: a wiring layer including a wiring pattern constituting a second coil formed within a range magnetically coupled to the first coil.

  Other structural features and the like of the wiring board and its mounting structure according to the present invention will be described with reference to embodiments of the invention described below.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the accompanying drawings.

  FIG. 1 shows a configuration of a PGA type wiring board according to an embodiment of the present invention in the form of a cross-sectional view together with a schematic configuration of an electronic component mounted thereon and a mounted body on which the electronic component is mounted.

  In the illustrated example, an MPU (semiconductor chip) 30 as an electronic component is surface-mounted via an electrode terminal 31 on the PGA type wiring board 10 of this embodiment, and this PGA type wiring board 10 is connected to the external connection. It shows a state in which it can be mounted on a mother board (mounted body) 40 such as a printed wiring board via terminals (pins) 19. In the present embodiment, it is assumed that the chip 30 is not mounted on the PGA type wiring board 10 and shipped, and the mounting of the chip 30 on the wiring board 10 and the mounting of the wiring board 10 on the mother board 40 are the shipping destinations. It shall be performed as appropriate.

  The electrode terminals 31 of the chip 30 include power supply electrode terminals (indicated by “P” in parentheses) and signal electrode terminals (indicated by “S” in parentheses). In the illustrated example, only four electrode terminals 31 are shown for simplification. Further, the chip 30 incorporates a differential output circuit 32 as one of its internal circuits, and its output is connected to a signal electrode terminal 31 (S).

  A PGA type wiring board 10 according to the present embodiment includes a resin substrate 11 constituting a wiring board main body as shown in the figure, wiring layers 12 and 13 each patterned on both surfaces of the resin substrate 11 in a required shape, Insulating layers 14 and 15 are provided as protective films formed so as to cover both surfaces except for the pad portions defined at required portions of the wiring layers 12 and 13, respectively. The wiring layer 13 opposite to the chip mounting surface side includes a wiring pattern CP1 constituting a signal transfer coil that characterizes the present invention. The shape and arrangement of the signal transfer coil (pattern) CP1 will be described later.

  The form of the resin substrate 11 constituting the wiring board body of the PGA type wiring board 10 is a board in which a wiring layer is formed on at least the outermost layer, and each wiring layer is electrically connected through the inside of the board. Is sufficient. For example, a multilayer wiring board using a build-up method can be used. This is a process in which an insulating layer is formed on both sides of a core substrate as a base substrate, via holes are formed in the insulating layer, and wiring patterns (wiring layers) including the inside of the via holes are sequentially stacked. It is. Epoxy resin is typically used as the material for the insulating layer, and copper (Cu) is typically used as the material for the wiring layer. The outermost wiring layers 12 and 13 formed in this way are each wiring layer formed at a required location inside the substrate (in the example of FIG. 1, only one wiring layer 16 is shown for simplicity of illustration). And includes wiring patterns for power supply and signals) and via holes (conductors filled in them) connecting each wiring layer to each other, or formed at a required location on the substrate. They are electrically connected to each other through the formed through holes (conductors filled therein).

  Further, since the electrode terminals 31 and the external connection terminals (pins 19) of the chip 30 to be mounted are joined to the pad portions defined in the outermost wiring layers 12 and 13, the wiring layers (Cu) 12 and 13 are joined. On top, nickel (Ni) plating and gold (Au) plating are applied in this order. This is to improve the contact property when the external connection terminal or the like is joined (Au layer), to improve the adhesion between the Au layer and the pad portion (Cu layer), and Cu diffuses into the Au layer. This is to prevent (Ni layer). That is, each pad portion has a three-layer structure of Cu / Ni / Au.

  Moreover, as the protective films 14 and 15, a solder resist layer is typically used. For example, a photosensitive epoxy resin is applied on the resin substrate 11 and the wiring layers 12 and 13, and the resin layer is patterned into a required shape (a shape excluding the pad portions of the wiring layers 12 and 13), thereby protecting the resin layer. Solder resist layers (insulating layers) 14 and 15 as films can be formed.

  Further, the pad portion (wiring layer 12) on the chip mounting surface side of the resin substrate 11 is soldered by a pre-solder or the like so that it can be easily connected to the electrode terminal 31 (solder bump, Au bump, etc.) when the chip 30 is mounted. 17 is attached. As the solder 17, lead-free solder such as Sn / Ag / Cu is used. However, it is not always necessary to provide the solder 17 for chip connection, and the pad portion is exposed so that the electrode terminals of the chip can be connected later when necessary (for example, at the shipping destination). It can be left as is.

  On the other hand, a pin (external connection terminal) 19 is joined to a pad portion (wiring layer 13) opposite to the chip mounting surface side via a solder 18. The pin 19 used here is of a nail head type and includes a disc-shaped or hemispherical head portion 19a and a shaft portion 19b joined to the head portion 19a. The shaft portion 19b will be described later. A contact part (contact) with the socket 41 provided on the mother board 40 side is configured. The pin 19 is made of, for example, gold (Au) plated on the surface of copper (Cu) or Kovar (alloy of Fe: 53%, Ni: 28%, Co: 18%). As the pin connecting solder 18, lead-free solder similar to the chip connecting solder 17 is used. The pin 19 is joined by applying a solder paste (solder 18) to the pad portion (wiring layer 13), contacting the head portion 19a of the pin 19 on the pad portion, and reflowing while maintaining the standing state. Done.

  Further, a ferromagnetic coating FM characterizing the present invention is formed on the peripheral surface of the shaft 19b (head 19a side) of the pin 19. As the material of the ferromagnetic coating FM, iron (Fe), cobalt (Co), nickel (Ni), or an alloy thereof is used. A ferromagnetic film FM as shown in the figure can be coated by applying electrolytic plating using each metal as a plating type to a required portion on the pin 19 (shaft portion 19b). As for the length of the ferromagnetic coating FM to be coated (longitudinal direction of the pin 19), at least the lower end portion thereof is a signal transfer coil (on the mother board 40 side described later) when the pin 19 is fitted into the socket 41. (Pattern) It is desirable to select a length that is below the position where CP2 is disposed. The function of the ferromagnetic film FM will be described later.

  In the illustrated example, the pins 19 are mounted on the surface of the resin substrate 11, but may be in the form of insertion mounting as used in a conventional general plastic type PGA type wiring substrate. That is, a through hole is formed in a required portion of the resin substrate, and electrical conduction is obtained by copper (Cu) plating or the like on the inner wall surface, and a pin is inserted (press-fit) into the through hole, or further solder impregnation thereafter. Then, the pins may be fixed to the substrate.

  On the other hand, on the mother board 40 side, a socket 41 as a connector (terminal connecting portion) to which the pins 19 are connected according to the terminal pitch (arrangement interval of the pins 19 of the PGA type wiring board 10) and the shape of the package to be mounted. Is surface mounted. In the illustrated example, for simplification, only one pin 19 and the corresponding socket 41 are shown in an enlarged manner, and this pin 19 is assigned for power supply. Therefore, power from a power supply circuit (not shown) surface-mounted on the mother board 40 is supplied to the socket 41 connected to the power supply pin 19.

  Although not specifically shown, the socket 41 is formed into a “round ring” shape in accordance with the shape of the pin 19 (“cylindrical shape” in the present embodiment) inserted into the socket 41 when viewed in cross section from above. Has been. Further, when viewed from the side as shown in the figure, the socket 41 is bent so that the diameter of the central portion of the socket 41 is smaller than the diameter of the other portions (that is, the central portion has a “neck”). Is formed. That is, the socket 41 is formed to be curved so that the outer peripheral surface of the pin 19 comes into close contact with the inner peripheral surface of the central portion of the socket 41 when the pin 19 is inserted. As a result, by inserting each pin 19 into the corresponding socket 41, the fitting state between the two is maintained, and the electrical continuity between the PGA type wiring board 10 and the mother board 40 is ensured.

  Further, a wiring layer 42 including a wiring pattern CP2 constituting a signal transfer coil characterizing the present invention is formed in the vicinity of the surface layer portion of the mother board 40. Further, as a protective film, the wiring layer 42 is covered so as to cover the wiring layer 42. An insulating layer 43 (for example, a solder resist layer) is formed. A differential input circuit (not shown) is surface-mounted on the motherboard 40 as one of its internal circuits, and a signal (current) extracted from the signal transfer coil (pattern) CP2 is supplied to the differential input circuit. Connected. The shape and arrangement of the signal transfer coil (pattern) CP2 will be described later.

  FIG. 2 is a cross-sectional view showing a state in which an MPU (semiconductor chip) 30 is mounted on the PGA type wiring board 10 of the present embodiment and further mounted on the mother board 40 (PGA type wiring board mounting structure). is there.

  When the chip 30 is mounted on the wiring substrate 10, it is bonded onto the pad of the chip 30 to the pad portion (solder 17 in FIG. 1) of the wiring layer 12 exposed from the upper solder resist layer (protective film) 14. The chip 30 is flip-chip connected so that the electrode terminals 31 such as solder bumps are electrically connected, and an underfill resin (not shown) such as an epoxy resin is filled in the gap and thermally cured. And glue. On the other hand, when the wiring board 10 is mounted on the mother board 40, each pin 19 (shaft portion 19b in FIG. 1) provided on the wiring board 10 is inserted into the corresponding socket 41 on the mother board 40 side. At that time, as described above, the socket 41 is curved so as to have a “neck” at the central portion thereof, so that the outer peripheral surface of the pin 19 of the wiring board 10 is connected to the inner peripheral surface of the central portion of the socket 41. It is possible to maintain electrical contact between the two in close contact with each other and in a state of being fitted to each other.

  In such a PGA type wiring board 10 mounting structure, required power supplied from a power supply circuit (not shown) surface-mounted on the mother board 40 is supplied via a socket 41 and a power supply pin 19 connected thereto. Via the corresponding power supply line (wiring layer 16) and via hole for interlayer connection (conductor filled therewith) in the wiring board 10, and further via the electrode terminal 31 (P) for power supply. And supplied to the chip 30.

  On the other hand, as for signals such as control signals and data, in the case of the present embodiment, signals output from the differential output circuit 32 built in the mounted chip 30 are transmitted via the signal electrode terminals 31 (S). The signal is transmitted to the wiring board 10 and input to the signal transfer coil CP1 (wiring layer 13) via a corresponding signal line (wiring layer 16) in the wiring board 10 and via holes for interlayer connection (conductors filled therein). As will be described later, it is converted into a magnetic field line corresponding to the signal through the coil CP1, and further converted into an induced current (original signal) according to the magnetic field line through a coil CP2 on the mother board 40 side. Is input to a differential input circuit (not shown).

  FIG. 3 shows the shape of the main part (a pair of signal transfer coils CP1 and CP2 provided in the vicinity of the pin 19 and the ferromagnetic film FM coated on the peripheral surface of the pin 19) in the mounting structure of FIG. It is a figure for demonstrating arrangement | positioning form. In the figure, (a) shows the configuration of the main parts (transmission-side coil CP1, ferromagnetic film FM) when viewing the package (wiring substrate 10) side along the line AA ′, and (b) shows A FIG. 4 shows the configuration of the main parts (receiving coil CP2, ferromagnetic coating FM) when the motherboard 40 side is viewed along the line -A ', and (c) shows an equivalent circuit thereof. Yes.

  As shown in FIG. 2, each signal transfer coil (transmission side coil CP1, reception side coil CP2) is in a plane parallel to the surface of the wiring board 10 on which the pin 19 is joined, that is, the longitudinal direction of the pin 19 3A and 3B, a pattern is formed in a ring shape that surrounds the periphery of the pin 19 and is partially open. At this time, the patterns of the ring portions of the coils CP1 and CP2 are preferably formed to have the same pattern width and overlap when viewed from the vertical direction. A signal (+/− differential output) output from the differential output circuit 32 built in the chip 30 is input to the open end of the pattern of the transmission side coil CP1 (the differential output of + and −). (Refer FIG.3 (c)). Similarly, a signal extracted from the open end of the pattern of the receiving coil CP2 is input to the input terminal (+, − differential input) of the differential input circuit 44 (FIG. 3 (c)).

  Thus, since the transmission side coil CP1 and the reception side coil CP2 are provided in a specific shape and arrangement, a magnetic circuit is configured as shown in FIG. 3C and functions as a transformer. . The ferromagnetic film FM coated on the peripheral surface of the pin 19 serves as a core (magnetic core) of the transformer, and facilitates transmission of magnetic lines of force (magnetic signal) from the input side to the output side.

  Next, the signal transfer operation performed in the mounting structure (FIG. 2) of the PGA type wiring board 10 according to the present embodiment will be described with reference to FIG.

  As described above, required power is supplied to the power supply pin 19 from a power supply circuit (not shown). At this time, the current flowing through the power supply pin 19 changes, so that FIG. As shown, a magnetic field line MP (indicated by a broken line) is generated around the pin 19. The magnetic field lines MP are generated in a plane orthogonal to the direction in which the current flows in the pin 19, that is, in a plane parallel to the plane on which the signal transfer coils (patterns) CP1 and CP2 are formed. It does not act on CP2. That is, no induced current flows through the coils CP1 and CP2 under the influence of the magnetic field lines MP generated by the current flowing through the power supply pin 19.

  Next, as shown in FIG. 4B, when a signal (current) flows in a direction from one end of the transmission side coil CP1 to the other end (clockwise direction in the illustrated example), Magnetic field lines MS are generated around the current path in a plane orthogonal to the direction of current flow. In this case, since the current path is in a plane orthogonal to the longitudinal direction of the power supply pin 19, the magnetic field lines MS are generated in a plane along the longitudinal direction of the power supply pin 19 as indicated by a broken line on the right side in the drawing. . Note that the cross-sectional view (right side in the drawing) showing the generation of the magnetic force lines MS at this time corresponds to the configuration when viewed along the line B-B ′ in FIG. 3.

  The magnetic lines of force MS generated by the current flowing through the transmission side coil CP1 in this way are received through the ferromagnetic coil FM coated on the peripheral surface of the power supply pin 19 and the reception side coil CP2 disposed opposite to the transmission side coil CP1. To the receiving coil CP2 (intersect at right angles).

  As a result, as shown in FIG. 4C, an induced current flows through the receiving coil CP2 due to the linkage of the magnetic lines of force MS. That is, the receiving coil CP2 functions as a magnetic sensor, converts the change in the magnetic field lines MS linked thereto into a current, and reproduces the original signal.

  In this way, the electrical signal output from the transmission side (the differential output circuit 32 in the chip 30) is converted into a magnetic signal (magnetic lines of force MS) via the transmission side coil CP1 which is a part of the magnetic circuit. The differential signal mounted on the mother board 40 after being guided to the reception side coil CP2 through the ferromagnetic film FM which is a part of the same magnetic circuit, converted into the original electric signal through the reception side coil CP2. It is transferred to the input circuit 44 (see FIG. 3).

  As described above, according to the PGA type wiring substrate 10 (FIG. 1) and the mounting structure (FIG. 2) according to the present embodiment, the motherboard 40 can be used by utilizing the electrical connection between the pins 19 and the socket 41. While supplying necessary power to the MPU (semiconductor chip 30) from the side, a magnetic circuit (FIG. 3) includes a ferromagnetic film FM coated on the peripheral surface of the pin 19 and a pair of signal transfer coils CP1 and CP2. The signal output from the differential output circuit 32 in the chip 30 can be transferred to the differential input circuit 44 on the mother board 40 through (c). That is, since one pin 19 can have two functions (power supply and signal transmission), the number of pins 19 required for the package (wiring board 10) can be reduced to half.

  Therefore, if the number of pins required for the package is the same, the package (wiring board 10) according to the present embodiment can be downsized to approximately half the size of the conventional package.

  Even when it is necessary to increase the number of inputs / outputs due to the demand for higher integration, it is difficult to secure a sufficient number of pins (terminals) due to restrictions on the downsizing of the package in the conventional technology. However, in the present embodiment, since two functions of power supply and signal transmission can be realized using one pin, it is possible to sufficiently meet the demand for high integration.

  In the embodiment described above, the case where the pin 19 is used as the external connection terminal of the wiring board (package) has been described as an example. However, the gist of the present invention (a pair of coils (in a specific arrangement form near the external connection terminal) ( As shown in FIG. 2A, the present invention can be similarly applied regardless of the form of the external connection terminal. it can. An example is shown in FIG.

  FIG. 5 shows an embodiment in which conductive balls 20 are used as external connection terminals of a wiring board (package). A semiconductor chip 30 is mounted on the BGA type wiring board 10a, and a mother board (object to be mounted) 40a. FIG. 2 is a sectional view showing a state of mounting on the board (mounting structure of a BGA type wiring board).

  The BGA type wiring board 10a and its mounting structure according to this embodiment are for signal transfer that characterizes the present invention compared to the PGA type wiring board 10 (FIG. 1) and its mounting structure (FIG. 2) according to the above-described embodiment. The coil (pattern) CP1 is included in the wiring layer 16a in the resin substrate 11a in the vicinity of the external connection terminal (conductive ball 20), and the wiring layer including the signal transfer coil (pattern) CP2 on the mother board 40a side. A land portion 45 as a terminal connection portion to which an external connection terminal (conductive ball 20) of the wiring board 10a is connected is formed above 42 (in the vicinity of the surface layer portion). And a ball made of a ferromagnetic material (Fe, Ni, Co, etc.) (ferromagnetic ball FB) in a conductive ball 20 by reflow. Ferromagnetic ball FB even after bonding the land portion 45 differs in that so as to remain. Since other configurations are basically the same as those in the above-described embodiment (FIGS. 1 and 2), description thereof is omitted.

  When mounting the BGA type wiring board 10a on the mother board 40a, for example, solder balls (ferromagnetic balls FB) are formed on the pad portions of the wiring layer 13a exposed from the lower solder resist layer (protective film) 15. Are connected by reflow (solder bumps 20) and connected to the corresponding land portions 45 on the mother board 40a via the solder bumps 20 (including the ferromagnetic balls FB). Note that the method for mounting the chip 30 on the wiring board 10a is the same as that in the above-described embodiment, and a description thereof will be omitted.

  In the present embodiment (FIG. 5), the conductive ball (bump) 20 includes the same function as the ferromagnetic film FM coated on the peripheral surface of the pin 19 in the above-described embodiment (FIGS. 1 and 2). The transferred ferromagnetic ball FB guides the magnetic lines of force MS (FIG. 4) generated from the transmission side coil CP1 to the reception side coil CP2, whereby a signal can be transferred from the wiring board 10a to the mother board 40a.

  In each of the above-described embodiments, the case where the ferromagnetic film FM / the ferromagnetic ball FB is used to facilitate the transmission of the magnetic field lines MS generated from the transmission coil CP1 to the reception coil CP2 has been described as an example. As is apparent from the gist of the present invention, these members are not necessarily used. That is, when the transmission side coil CP1 and the reception side coil CP2 are in a very close positional relationship, the magnetic field lines generated from one coil have a magnetic field intensity that can sufficiently reach the other coil. In such a case, the ferromagnetic coating FM / ferromagnetic ball FB can be omitted.

  Further, in each of the above-described embodiments, when the signal transfer coils CP1 and CP2 are each formed by a single-layer wiring pattern as shown in FIGS. 3A and 3B (that is, a coil having one turn) However, as is apparent from the gist of the present invention, the coils CP1 and CP2 need not be composed of a single-layer wiring pattern. That is, each of the coils CP1 and CP2 may have a structure (corresponding to a coil having a plurality of turns) composed of a plurality of wiring patterns (ring-shaped patterns). However, in the case of this form, the wiring patterns of a plurality of layers constituting each coil are connected in series via via holes (conductors filled therein) appropriately formed in the interlayer insulating layer. It is necessary to appropriately form a pattern.

  In the embodiment shown in FIG. 1 and FIG. 2, the case where the signal transfer coils CP1 and CP2 are separately provided in the vicinity of the pin 19 has been described as an example, but as is apparent from the gist of the present invention. Of course, the arrangement of the coils CP1 and CP2 is not limited to this. For example, it can be considered that the coil is integrated with the pin. However, in the case of this form, it is necessary to take an appropriate measure (such as interposition of an insulating material) for insulating between the pins and the coil so that the pins and the coil are not in electrical contact. Alternatively, as another form, a structure in which a socket and a coil are integrated may be considered. Similarly, in this case, it is necessary to take an appropriate measure so that the socket and the coil do not come into electrical contact.

In each of the above-described embodiments, the case where the resin substrate 11 (11a) is used as a package substrate has been described as an example. However, the present invention is not limited to the resin substrate. For example, it may be in the form of a silicon substrate used in CSP (chip size package). In the case of this embodiment, instead of the wiring layers 12 and 13 (13a) including the pad portion, an aluminum (Al) wiring layer (including the pad portion) is provided on the silicon (Si) substrate. Instead of the solder resist layers 14 and 15, a passivation film made of SiO ₂ , SiN, polyimide resin or the like is provided. Moreover, you may use a ceramic substrate etc. as another form.

It is sectional drawing which shows the structure of the PGA type wiring board which concerns on one Embodiment of this invention with the schematic structure of the to-be-mounted body by which the electronic component mounted in this and this mounted. It is sectional drawing which shows the mounting structure of the PGA type wiring board of FIG. FIG. 3 is a diagram for explaining the shape and arrangement of the main parts (a pair of signal transfer coils provided in the vicinity of a pin and a ferromagnetic film coated on the peripheral surface of the pin) in the mounting structure of FIG. 2; Yes, (a) is a configuration diagram of the main part when looking at the package side along the line AA ′, (b) is a configuration of the main part when looking at the motherboard side along the line AA ′. FIG. 2C is an equivalent circuit diagram thereof. It is a figure for demonstrating the function (operation | movement) of the principal part, (a) is a figure which shows a mode that a magnetic force line generate | occur | produces the circumference | surroundings when an electric current is sent through a pin, (b) is an electric current in a transmission side coil. The figure which shows a mode that the magnetic force line which generate | occur | produces when flowing is carried out and the receiving side coil is linked, (c) is a figure which shows a mode that an induced current flows into a receiving side coil by the linkage of the magnetic field line. It is sectional drawing for demonstrating the mounting structure of the BGA type | mold wiring board which concerns on other embodiment of this invention.

Explanation of symbols

10, 10a ... wiring board (semiconductor package),
11, 11a ... Resin substrate (wiring board body),
12, 13, 13a, 16, 16a, 42 ... wiring layer,
14, 15, 43 ... solder resist layer (protective film / insulating layer),
19: Pin (external connection terminal),
20: Conductive ball (external connection terminal),
30: Semiconductor chip (electronic component),
31 ... Electrode terminal,
40, 40a ... Motherboard (mounted body),
41. Socket (connector / terminal connection part),
45 ... land part (terminal connection part),
CP1, CP2 ... Coil for signal transfer (wiring pattern),
FM ... ferromagnetic coating,
FB ... ferromagnetic balls,
MS: Magnetic field lines (converted magnetic signal).

Claims (6)

A wiring board adapted to be mounted on a mounted body having a terminal connection portion and a wiring pattern constituting a first coil,
An external connection terminal connected to the terminal connection portion of the mounted body;
Position that surrounds the periphery of the external connection terminal in a state of being insulated from the external connection terminal when the wiring board is viewed in a plane within a plane parallel to the surface on which the external connection terminal is mounted of the wiring board And a wiring pattern constituting the second coil formed within a range magnetically coupled to the first coil via a magnetic field line generated by the current when the current flows. Wiring board to be used.   The wiring board according to claim 1, wherein a member made of a ferromagnetic material is provided on the surface or inside of the external connection terminal.   The wiring board according to claim 1, wherein the wiring pattern constituting the second coil is formed in a ring shape in which a part is opened. A wiring board on which electronic components are mounted;
A mounted body on which the wiring board is mounted;
The mounted body includes a terminal connection portion and a wiring layer including a wiring pattern constituting the first coil,
The wiring board, an external connection terminal connected to the terminal connecting portion, the wiring board of the external connection terminal is in a plane parallel to the surface on the side to be mounted, the said wiring board in a plan view Formed in a position that surrounds the periphery of the external connection terminal in a state insulated from the external connection terminal , and within a range that is magnetically coupled to the first coil via magnetic lines generated by the current when the current flows. A wiring board mounting structure comprising: a wiring layer including a wiring pattern constituting the second coil.   5. The wiring board mounting structure according to claim 4, wherein a member made of a ferromagnetic material is provided on the surface or inside of the external connection terminal of the wiring board. The wiring pattern constituting the second coil is formed in a ring shape partially opened,
The wiring pattern constituting the first coil is in a plane parallel to the wiring pattern constituting the second coil on the wiring board, and when the mounted body is viewed in plan, the terminal connection portion 5. The wiring board mounting structure according to claim 4, wherein the wiring board mounting structure is formed in a ring shape partially opened at a position surrounding the periphery.

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