JP2003304045A - Mother board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mother board equipped with a circuit which is equivalent to the conventional circuit at a lower manufacturing cost. <P>SOLUTION: On one surface of this mother board 1 formed by mounting a semiconductor device on a multilayered printed wiring board, connectors 6 for mounting an external input-output terminal board 3 in a freely attachable/ detachable state and connectors 7 for mounting a control substrate 4 in a freely attachable/detachable state are disposed at prescribed positions. On the other surface of this mother board 1, connectors 8 and 9 for mounting a paddle board 5 on which a circuit pattern for electrically connecting the terminal board 3 and control substrate 4 to each other is formed in an attachable/detachable state are respectively disposed at positions which become the back sides of the connectors 6 and 7 beyond the multilayered wiring board. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mother board using a multilayer printed wiring board, and more particularly to a mother board in which the number of layers of the multilayer printed wiring board is reduced by bypassing a signal to a paddle board mounted on one surface. Regarding

[0002]

2. Description of the Related Art Conventionally, a control device for electronic equipment is a "motherboard" in which various electronic components are mounted on a printed wiring board.
It is mainly composed of a printed circuit board called.
In recent years, in order to reduce the size and increase the performance of devices, it is required to increase the mounting density of these electronic components. Therefore, a motherboard has a plurality of insulating layers and conductive layers (wiring patterns) on an insulating substrate. Often formed using a "multilayer printed wiring board" formed over layers. The wiring pattern is formed by removing a part of the conductive layer by etching or the like.

FIG. 17 shows a conventional mother board formed by using a multilayer printed wiring board. An external input / output terminal plate 13 is mounted on the mother board 11 via a connector 16, and a control board 14 is mounted on the mother board 11 via a connector 17. The external input / output terminal board 13 is a board on which a circuit serving as an interface (I / F) for transmitting / receiving a signal to / from an external device (not shown) is formed, and electronic components necessary for transmitting / receiving the signal are mounted. is there. The control board 14 is provided with a circuit for performing a predetermined process on an input signal and outputting the processed signal.
It is a board on which electronic components necessary for processing signals are mounted. Motherboard 11 and external input / output terminal board 1
3 and the control board 14 are electrically connected to each other via connectors 16 and 17. Note that, in general,
A plurality of connectors for mounting a control board are arranged on the mother board 11, and a control board is mounted on each of the connectors. However, here, for the sake of simplification of description, only one control board 14 is provided. An example will be explained.

An external signal input to the external input / output terminal plate 13 is input to the control board 14 via the connector 16, the mother board 11 and the connector 17. The external signal input to the control board 14 is subjected to predetermined processing in the control board 14, and then the connector 17 and the motherboard 1 are processed.
1 and the external input / output terminal board 1 via the connector 16
It is input again in 3. This signal is output to the outside from the external input / output terminal board 13. Therefore, as shown in FIG.
Signal path from 3 to control board 14 (input path)
And a signal path (output path) from the control board 14 to the external input / output board 13 must be provided separately.

FIG. 18 shows an example of forming wiring patterns of two circuits on the mother board 11. As shown in (a), in the case where the circuits to be formed have a shape that does not interfere with each other (in other words, a shape that does not contact when overlapping), both wiring patterns can be formed on one conductive layer. On the other hand, as shown in (b), in the case where the circuits to be formed have a shape that interferes with each other (in other words, a shape in which they contact each other when superposed), only one of them is formed in one conductive layer. Therefore, each wiring pattern must be formed in different conductive layers.
Here, the case where two wiring patterns are formed is taken as an example, but when three or more wiring patterns are formed, the possibility that the wiring patterns will interfere with each other is further increased.

As described above, when the number of control boards mounted on the mother board 11 is increased in order to realize the higher function of the mother board 11, the wiring density is increased and the possibility that the wiring patterns interfere with each other increases. . Even if the wiring patterns have a shape that does not cause interference, the wiring patterns may be too close to each other, which may have an adverse effect. In order to prevent the occurrence of interference and adverse effects of the wiring pattern, since the wiring pattern has to be formed separately in a plurality of conductive layers,
It is necessary to form the motherboard 11 using a printed wiring board having a large number of layers.

[0007]

However, the wiring density is not always uniform over the entire surface of the motherboard 11. For example, when the wiring density is partially high and the wiring density of other portions is low, the printed wiring board applied to the mother board 11 must be selected with reference to the portion with high wiring density. Therefore, an insulating layer and a conductive layer are stacked more than necessary at a portion where the wiring density is low.

Generally, the price of a multilayer printed wiring board increases as a multiplier when the number of layers exceeds a predetermined number. Therefore, if a mother board having a circuit equivalent to the conventional one can be formed by using a multilayer printed wiring board having a smaller number of layers than the conventional one, a significant cost reduction can be achieved. Further, the price of the multilayer printed wiring board increases when the outer dimensions exceed a certain size. Therefore, if a mother board having a circuit equivalent to the conventional one can be formed by using a multilayer printed wiring board having a smaller outer dimension than the conventional one, the manufacturing cost of the mother board can be reduced.

The present invention has been made in view of the above problems, and an object thereof is to provide a mother board having a circuit equivalent to the conventional one at a lower manufacturing cost.

[0010]

In order to achieve the above object, the present invention provides, as a first aspect, a mother board formed by mounting a semiconductor device on a multilayer printed wiring board, which comprises: At least one pair of daughter board connectors for detachably mounting separate daughter boards are provided on one surface, and the other surface of the multilayer printed wiring board is sandwiched between the daughter board connectors for daughter boards. Provided is a mother board having a paddle board connector for mounting a paddle board, which is electrically connected to the daughter board connector at each of the positions on the back side of the connector. According to the above configuration, at least a part of the signals transmitted and received between the daughter boards can be transmitted through the path through the paddle board connector. Therefore, it is not always necessary to form all the circuits as a wiring pattern on the motherboard. For example, it is possible to eliminate the need to form a path for transmitting a signal transmitted / received between daughter boards that are rarely mounted as a wiring pattern on the motherboard.

In the first aspect of the present invention, the paddle board having a circuit for electrically connecting the daughter boards mounted via the pair of daughter board connectors is mounted via the paddle board connector. Preferably. According to the above configuration, a signal transmitted / received between each daughter board can be transmitted via the paddle board mounted via the paddle board connector.
Further, it is preferable that at least a part of signals transmitted and received between the daughter boards mounted via the pair of daughter board connectors are transmitted via the paddle board. This makes it possible to form a circuit serving as a signal transmission path that is not preferably affected by a signal transmitted via another wiring pattern so as not to be affected by another signal. In addition to this, it is preferable that a circuit for transmitting only a synchronization signal transmitted / received between the daughter boards mounted via the pair of daughter board connectors is preferably formed on the paddle board. This allows
A circuit that serves as a transmission path of a synchronization signal that is not preferably affected by other signals can be separated from the transmission path of other signals.

In order to achieve the above object, the present invention provides, as a second aspect, a motherboard formed by mounting a semiconductor device on a multilayer printed wiring board,
At least one group of at least two daughter board connectors for detachably mounting separate daughter boards is provided on one surface of the multilayer printed wiring board, and the other surface of the multilayer printed wiring board is provided on the other surface. ,
Each of the positions on the back side of the daughterboard connector across the multilayer printed wiring board is electrically connected to the daughterboard connector, and a paddleboard connector for mounting the paddleboard is provided. It provides a motherboard that does. According to the above configuration, at least a part of the signals transmitted and received between the daughter boards can be transmitted through the path through the paddle board connector. Therefore, it is not always necessary to form all the circuits as a wiring pattern on the motherboard. For example, it is possible to eliminate the need to form a circuit as a wiring pattern on the motherboard for transmitting signals transmitted and received between daughter boards that are rarely mounted.

In the second aspect of the present invention, each of the daughter boards mounted via the daughter board connectors belonging to the same group is replaced with another daughter board among the other daughter boards mounted via the daughter board connectors belonging to the same group. It is preferable that a paddle board including a circuit electrically connected to at least one is mounted via a paddle board connector. According to the above configuration,
A signal transmitted / received between the daughter boards can be transmitted via the paddle board mounted via the paddle board connector. In addition to this, it is preferable that at least a part of the signals transmitted and received between the daughter boards mounted via the daughter board connectors belonging to the same group are transmitted via the paddle board. This allows
It is possible to form a wiring pattern serving as a transmission path of a signal that is not preferably influenced by a signal transmitted via another circuit so as not to be influenced by another signal. In addition, it is preferable that the paddle board is formed with a circuit for transmitting only a synchronization signal transmitted / received between the daughter boards mounted via the daughter board connectors belonging to the same group. This makes it possible to separate a circuit serving as a transmission path of a synchronization signal that is not preferably affected by another signal from a circuit serving as a transmission path of another signal.

In order to achieve the above object, as a third aspect of the present invention, there is provided a mother board formed by using at least two multilayer printed circuit boards on which semiconductor devices are mounted, each of which is a multilayer printed board. At least one daughter board connector for detachably mounting the daughter board is provided on one surface of the board, and the daughter board connector and the daughter board connector are respectively provided on the other surface at positions on the back side of the daughter board connector. At least an electrically connected paddle board connector is provided, and each of the multilayer printed boards is detachably mounted on at least any two of the multilayer printed boards via the paddle board connector. Motherboard characterized by being electrically connected through one paddle board It is an offer soil. According to the above configuration, a motherboard provided with a circuit equivalent to a motherboard according to the related art can be formed by using a multilayer printed wiring board having a smaller outer dimension than the conventional one. In addition, since the signal transmitted and received between each daughter board is transmitted through the paddle board, a multilayer printed wiring board having a smaller number of layers than the multilayer printed wiring board applied to the motherboard according to the related art is used. A motherboard having a circuit equivalent to can be formed.

In order to achieve the above object, the present invention provides, as a fourth aspect, a mother board formed by using first and second multilayer printed boards on which semiconductor devices are mounted. And at least one daughter board connector for detachably mounting the daughter board on one surface of each of the second and multi-layered printed circuit boards, and on the other surface at a position behind the daughter board connector. Is provided with a paddle board connector electrically connected to the daughter board connector, and the first and second paddle board connectors are provided through the paddle board connector.
And a first printed circuit board and a second printed circuit board electrically connected to each other by a paddle board detachably mounted on the multilayer printed circuit board. According to the above configuration, a motherboard provided with a circuit equivalent to a motherboard according to the related art can be formed by using a multilayer printed wiring board having a smaller outer dimension than the conventional one. In addition, since the signal transmitted and received between the first and second daughter boards is transmitted through the paddle board, the number of layers is smaller than that of the multilayer printed wiring board applied to the motherboard according to the related art. Can be used to form a motherboard having a circuit equivalent to the conventional one.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS [First Embodiment] A first embodiment in which the present invention is preferably implemented will be described. In Figure 1,
1 shows a communication device to which a motherboard according to the present embodiment is applied. This communication device has a mother board 1, an external input / output terminal board 3, a control board 4, and a paddle board 5. The mother board 1 is a printed circuit board to which a multilayer printed wiring board is applied, and electronic components such as a CPU and a memory are mounted on the mother board 1. On one side (front side) of the motherboard 1,
A connector 6 and a connector 7 are provided. Further, a connector 8 and a connector 9 are provided on the surface (rear surface) opposite to this. The external input / output terminal board 3 is
This is a substrate on which a circuit that serves as an interface (I / F) for transmitting and receiving signals to and from an external device (not shown) is formed, and electronic components necessary for transmitting and receiving signals are mounted. An external input / output cable 2 is connected to the external input / output terminal plate 3, and signals are input / output through the external input / output cable 2. The control board 4 is a board on which a circuit for performing predetermined processing on an input signal and outputting the signal is formed, and on which electronic components necessary for processing the signal are mounted. The paddle board 5 has a predetermined electric circuit (wiring pattern) formed therein, and electrically connects the connector 8 and the connector 9. As shown in FIG. 2 and FIG. 3, the external input / output terminal board 3 is mounted on the surface of the mother board 1 via the connector 6, and the control board 4 is mounted via the connector 7. A paddle board 5 is mounted on the back surface of the mother board 1 via connectors 8 and 9. It should be noted that the connector 6 and the connector 8 are arranged at positions on the back side with the mother board 1 interposed therebetween, and the connector 7 and the connector 9 are arranged on the mother board 1 side.
It is placed at the back side across.

It should be noted that the mother board 1 generally has a plurality of connectors for mounting the control board, and the control board is mounted on each of them, but here, for simplification of description, the control board 4 is mounted. An example will be described in which only one is mounted.

In this communication device, the transmission paths from the external input / output cable 2 to the external signal input to the external input / output terminal board 3 to the control board 4 are as follows (1) and (2). There are two ways. (1) Transmission path of external input / output cable 2 → external input / output terminal board 3 → connector 6 → motherboard 1 → connector 7 → control board 4. (2) External input / output cable 2 → External input / output terminal board 3 → Connector 6 → Motherboard 1 → Connector 8 → Paddle board 5 → Connector 9 → Motherboard 1 → Connector 7
→ Transmission path of the control board 4.

Further, the transmission path from the signal processed by the control board 4 to the output from the external input / output terminal board 3 to the external input / output cable 2 is either of the following two (1 ') and (2'). There is. These are transmission paths in the reverse order of the above (1) and (2). (1 ') Transmission path of control board 4-> connector 7-> mother board 1-> connector 6-> external input / output terminal board 3-> external input / output cable 2. (2 ') Control board 4-> connector 7-> mother board 1-> connector 9-> paddle board 5-> connector 8-> mother board 1-> connector 6-> external input / output terminal board 3-> external input / output cable 2 transmission path. Therefore, as shown in FIGS. 4 and 5, the communication device according to the present embodiment includes the external input / output terminal board 3 and the control board 4.
All or a part of the wiring connecting with and can be formed on the paddle board 5.

As described above, in the communication device according to the present embodiment, the paddle board 5 functions as a bypass of the transmission path of the signal transmitted / received between the external input / output terminal board 3 and the control board 4, so that FIG. As shown in, the printed wiring board applied to the mother board 1 can be selected with reference to a portion having a low wiring density. Thus, a multilayer printed wiring board having a smaller number of layers than the conventional one can be used to form a motherboard having a circuit equivalent to the conventional one. In addition, connectors 8, 9 for mounting the paddle board,
Since it is provided on the back side of the connectors 6 and 7 for mounting the daughter board (external input / output terminal board 3 and control board 4), a space for newly arranging the connectors 8 and 9 for mounting the paddle board on the motherboard 1 is provided. There is no need to provide it.

The motherboard 1 according to this embodiment has the following advantages as compared with a motherboard in which all wirings (circuits) are arranged as wiring patterns in a multilayer printed wiring board.

First, as shown in FIG. 7, the motherboard 1
The paddle board 5 and the paddle board 5 can be formed in different circuits in different wiring directions. Therefore, unlike a communication device according to the related art in which all circuits are formed on the mother board 1 as wiring patterns, it is necessary to avoid one of the patterns from another layer in order to avoid a collision between the vertical pattern and the horizontal pattern. There is no. In addition, in this figure, in order to show signals in the horizontal direction, the mother board 1 on which two paddle boards 5 are installed is shown.

Further, as shown in FIG. 8, a transmission path for a signal which is easily influenced by another wiring pattern or a signal which is not particularly preferable for being influenced by another wiring pattern is referred to as a transmission path for another signal. It becomes possible to separate.
For example, since the synchronization signal (clock signal or the like) is a signal that serves as a reference for the operation of the electronic device, it is not preferable that these signals are influenced by the signals transmitted in other wiring patterns. In addition, since an external signal input from an external device or the like is often a high frequency signal, it is easily affected by a signal transmitted in another wiring pattern. Therefore, for example, circuits for transmitting these signals are formed as a wiring pattern on the paddle board 5, and electric power is supplied to the wiring for transmitting control signals between the respective control boards and the board or semiconductor element mounted on the motherboard 1. By forming the power supply circuit and the like on the mother board 1 as a wiring pattern, it is possible to improve electric characteristics.

Although a case where two daughter boards (external input / output terminal board 3 and control board 4) are mounted on the mother board 1 has been described as an example here, three or more daughter boards are mounted. In the case of a motherboard, the same effect as above can be obtained. For example, as shown in FIGS. 9 and 10, the control boards 4a and 4b are the connectors 7a, respectively.
Also when mounted on the mother board 1 via the terminals 7 and 7b, similarly to the above, at least a part of the circuit serving as a transmission path of signals transmitted and received between the control boards 4a and 4b and the external input / output terminal board 3 is provided. It can be formed on the paddle board 5.

[Second Embodiment] A second embodiment in which the present invention is preferably implemented will be described. FIG. 11 shows the communication device according to the present embodiment. This communication device has a mother board 1, an external input / output terminal board 3, a control board 4, and a paddle board 5 as in the first embodiment. In this embodiment, the mother board 1 is an electrically separated mother board. 1a and a mother board 1b.

As shown in FIG. 12, the external input / output terminal plate 3 is mounted on one surface (front surface) of the mother board 1a via the connector 6, and the surface of 1b is controlled via the connector 7. A board 4 is mounted. Also, as shown in FIG. 13, paddles are attached to the surfaces (rear surfaces) opposite to the surfaces of the mother boards 1a and 1b on which the external input / output terminal board 3 and the control board 4 are mounted via connectors 8 and 9, respectively. Board 5 is mounted.

The external input / output terminal board 3 and the control board 4 are the same as those in the first embodiment. Motherboard 1 (1a,
1b) is a printed circuit board to which a multilayer printed wiring board is applied, and electronic components such as a CPU and a memory are mounted on each of 1a and 1b. The paddle board 5 has a predetermined electric circuit formed therein, and electrically connects the connector 8 and the connector 9. Note that, for example, in FIG.
As shown in FIG. 2, the motherboards 1a and 1b are provided with a plurality of connectors for mounting a control board and a paddle board, and the control board and the paddle board are mounted on each of them. Here, for simplification of description, a case where only one control board 4 is mounted on the mother board 1b will be described as an example.

As shown in FIG. 15, in this communication device, an external signal input from the external input / output cable 2 to the external input / output terminal plate 3 is transferred to the external input / output cable 2.
→ external input / output terminal board 3 → connector 6 → motherboard 1a → connector 8 → paddle board 5 → connector 9 → motherboard 1b → connector 7 → input to the control board 4 through the transmission path of the control board 4 and predetermined in the control board 4 Processing is performed. Similarly, signals processed by the control board 4 are: control board 4 → connector 7 → motherboard 1b
→ Connector 9 → Paddle board 5 → Connector 8 → Motherboard 1a → Connector 6 → External I / O terminal board 3 → External I / O cable 2 is transmitted to the external I / O terminal board 3 via the transmission path, and from here the external I / O cable 2 is output.

By electrically connecting the mother board 1a and the mother board 1b, which are electrically separated from each other, through the paddle board 5 as described above, a mother board having a circuit equivalent to the conventional one is provided as compared with the conventional mother board. It can be formed using a multilayer printed wiring board having a small outer dimension.

Here, the mother board 1 is 1a.
Although the description has been given by taking as an example the case where the two are electrically separated from each other, 1b and 1b, the same effect as described above can be obtained also in the case where the structure is electrically separated into three or more. For example, as shown in FIG. 16, when the mother board 1 is electrically divided into 1a, 1b and 1c, if the respective mother boards are connected using the paddle board 5, the outer dimensions are smaller than the conventional one. It becomes possible to form the motherboard 1 using a multilayer printed wiring board.

The above embodiments are examples of preferred embodiments of the present invention, and the present invention is not limited to these. For example, although a case has been described with the above embodiments as an example where one control board and one external input / output terminal board are mounted, the present invention is not limited to this. In other words, any number of control boards and external input / output terminal boards can be mounted. Further, the mother board 1 and the paddle board 5 are not limited to the shapes shown in the respective drawings, and may have any shape. As described above, the present invention can be variously modified.

[0032]

As is apparent from the above description, according to the present invention, it is possible to provide a mother board having a line equivalent to the conventional one at a lower manufacturing cost.

[Brief description of drawings]

FIG. 1 is a diagram showing a communication device to which a motherboard according to a first exemplary embodiment of the present invention is applied.

FIG. 2 is a view showing a state in which an external input / output terminal board and a control board are detachably mounted on the motherboard according to the first embodiment.

FIG. 3 is a view showing a state in which a paddle board is detachably mounted on the motherboard according to the first embodiment.

FIG. 4 is a diagram showing a state in which all the transmission paths of signals transmitted and received between an external input / output terminal board and a control board are formed on a paddle board.

FIG. 5 is a diagram showing a state in which a part of a transmission path of a signal transmitted / received between an external input / output terminal board and a control board is formed on a paddle board.

FIG. 6 is a diagram showing a difference in wiring density between a case where all signal transmission paths are formed as a wiring pattern on a motherboard and a case where a paddle board is applied.

FIG. 7 is a diagram showing a state where a wiring pattern is formed on a mother board and a paddle board such that signal transmission directions are different from each other.

FIG. 8 is a diagram showing a state in which a wiring pattern is formed on a mother board and a paddle board so that signals are separated and transmitted.

FIG. 9 is a diagram showing a state in which a part of a transmission path of a signal transmitted / received between three daughter boards mounted on a mother board is formed on the daughter board.

FIG. 10 is a diagram showing a state in which a part of a transmission path of a signal transmitted / received between three daughter boards mounted on a mother board is formed on a paddle board.

FIG. 11 is a diagram showing a communication device to which a motherboard according to the second exemplary embodiment of the present invention is applied.

FIG. 12 is a view showing a state in which an external input / output terminal board and a control board are detachably mounted on the motherboard according to the second embodiment.

FIG. 13 is a view showing a state in which a paddle board is detachably mounted on a motherboard according to the second embodiment.

FIG. 14 is a view showing a state in which a plurality of paddle boards are detachably mounted on a motherboard according to the second embodiment.

FIG. 15 is a diagram showing a state in which wiring for connecting an external input / output terminal board and a control board is formed via a paddle board.

FIG. 16 is a view showing a state where motherboards that are electrically divided into three parts are connected using a paddle board.

FIG. 17 is a diagram showing a state in which wiring for connecting an external input / output terminal board and a control board is formed on a conventional motherboard.

FIG. 18 is a diagram showing an example of forming two wiring patterns on a mother board. (A) shows the case where the formed circuits do not interfere with each other. (B) shows the case where the formed circuits interfere with each other.

[Explanation of symbols]

1 Motherboard 2 External input / output cable 3 External input / output terminal board 4 control board 5 paddle boards 6, 7, 8, 9 connectors

Claims (10)

[Claims] 1. A mother board formed by mounting a semiconductor device on a multilayer printed wiring board, the daughter board for detachably mounting separate daughter boards on one surface of the multilayer printed wiring board. At least one pair of connectors is provided, and the other surface of the multilayer printed wiring board is electrically connected to the daughter board connector at each position on the back side of the daughter board connector with the multilayer printed wiring board sandwiched therebetween. A mother board, which is connected and provided with a paddle board connector for mounting a paddle board. 2. A paddle board equipped with a circuit for electrically connecting the daughter boards mounted via the pair of daughter board connectors to each other is mounted via the paddle board connector. The motherboard according to claim 1. 3. The paddle board, wherein at least a part of signals transmitted and received between the daughter boards mounted via the pair of daughter board connectors respectively is transmitted. Motherboard described in 2. 4. The paddle board is provided with a circuit for transmitting only a synchronization signal transmitted and received between the daughter boards mounted via the pair of daughter board connectors. Motherboard listed. 5. A mother board formed by mounting a semiconductor device on a multilayer printed wiring board, the daughter board for detachably mounting separate daughter boards on one surface of the multilayer printed wiring board. At least one group including at least two connectors is provided, and on the other surface of the multilayer printed wiring board, at each of positions on the back side of the daughterboard connector with the multilayer printed wiring board sandwiched therebetween, A mother board, which is electrically connected to a daughter board connector and provided with a paddle board connector for mounting a paddle board. 6. Each of the daughter boards mounted via the daughter board connector belonging to the same group is electrically connected to at least one of the other daughter boards mounted via the daughter board connector belonging to the same group. The mother board according to claim 5, wherein a paddle board having a circuit connected to is mounted via the paddle board connector. 7. The paddle board according to claim 7, wherein at least a part of signals transmitted and received between the daughter boards mounted via the daughter board connector belonging to the same group is transmitted through the paddle board. Motherboard described in 6. 8. The paddle board is formed with a circuit for transmitting only a synchronization signal transmitted / received between the daughter boards mounted via the daughter board connectors belonging to the same group. Motherboard described in 7. 9. A mother board formed by using at least two multilayer printed boards on which semiconductor devices are mounted, wherein a daughter board is detachably mounted on one surface of each multilayer printed board. At least one daughter board connector is provided, and at each of the positions on the other surface that is the back side of the daughter board connector,
A paddle board connector electrically connected to the daughter board connector is provided, and each of the multilayer printed boards is connected to at least any two of the multilayer printed boards via the paddle board connector. A mother board electrically connected via at least one paddle board detachably mounted. 10. A mother board formed by using first and second multilayer printed boards on which semiconductor devices are mounted, wherein one surface of each of the first and second multilayer printed boards has: At least one daughter board connector for detachably mounting the daughter board is provided,
A paddle board connector electrically connected to the daughter board connector is provided at each of the positions on the other surface that is the back side of the daughter board connector, and the first and first paddle board connectors are provided through the paddle board connector. Two
The first multilayer printed circuit board and the second printed circuit board are electrically connected by a paddle board detachably mounted on the multilayer printed circuit board.