JP5285303B2 - Electronics - Google Patents

Description

  The present invention relates to a structure of an electronic device using a board-to-board type connector.

  Conventionally, the connection between the substrates is realized by using a connector unit including a pair of connectors. That is, a pair of connectors (for example, a male connector and a female connector) are mounted on each of the two substrates to be connected, and the mounted connectors are fitted to each other, thereby realizing connection between the substrates. Is.

  Recently, with the improvement of functions of various electronic devices such as mobile phone terminals and laptop computers, the configuration of electronic circuits built into these electronic devices tends to become complicated, and a plurality of substrates that are diversified. There is a need to make a connection between. Thus, for the purpose of preventing an increase in the installation area inside the electronic device, it is a mainstream to install a plurality of substrates stacked in parallel. A so-called board-to-board type connector is used as a technique for realizing such physical and electrical connection between the substrates stacked in parallel. That is, a board-to-board connector (hereinafter referred to as a BtoB connector) is composed of a pair of male connector and female connector, which are mounted so as to oppose each of two boards stacked in parallel. The connection between the substrates is realized by fitting the concave portion and the convex portion.

  FIG. 1 shows a mounting form of a BtoB connector of a conventional electronic device. As illustrated, a BtoB connector is mounted on the FPC board 1. Specifically, the terminals 6 of the connector body 2 are soldered on the mounting electrodes 4 provided on the FPC board 1. At this time, in order to mount the BtoB connector, it is common to provide a region 3 by securing a certain dimension of the outer shape of the FPC board 1 from the mounting electrode 4 which is a mounting land of the BtoB connector. Since the useless area 3 is generated in the FPC board 1, the size of the FPC board 1 is increased, which increases the cost of the FPC board 1. FIG. 2 schematically shows a cross-sectional configuration when this useless region 3 is deleted. When the outer shape of the FPC board 1 is reduced with the structure of FIG. 1, the mounting electrode 4 and the back pattern 5 come close to each other at the end face of the board as shown in FIG. 2, and the mounting electrode 4 and the back pattern 5 are short-circuited. Problems occur. Further, FIG. 3 shows a configuration for avoiding this short circuit. As shown in the drawing, the back pattern 5 is not formed up to the outer edge of the FPC board 1. In this case, there is a problem that the sagging 8 of the FPC board 1 occurs in the portion where the back pattern 5 is not present, and the soldering defect 7 occurs.

  Furthermore, if a pattern is not provided on the back side of the FPC board 1 at a position corresponding to the terminal 6, the parallelism of the FPC board will not be obtained, and sagging of the FPC board and poor solder connection will occur.

  As described above, in the conventional mounting form of the connector on the FPC board, there is a problem that reliability is lowered when the connector is mounted with a small board size. Accordingly, an object of the present invention is to realize a configuration in which a high mounting reliability can be obtained even when a connector is mounted on the outer shape of the FPC board 1 with a smaller outer shape.

  In order to solve the above-described problem, a floating pattern 9 (dummy pattern) that is electrically independent is formed on the outer side of the FPC board so that there is no problem even if the front-side mounting electrode 4 and the back-side pattern are short-circuited. , And provided at a position corresponding to the terminal of the connector. In this way, by providing the single floating pattern 9 that does not cause a problem even if short-circuited with the mounting electrode 4 separately from the back pattern 5, it is possible to avoid problems due to short-circuiting of the pattern. Further, the floating pattern 9 may be installed separately so as to correspond to each terminal of the connector so that a short circuit between the connector terminals does not occur via the floating pattern 9.

  The external size of the FPC board can be reduced while maintaining the reliability of connector mounting. Furthermore, the FPC board is reduced, so that a space for mounting other components can be secured, the degree of freedom in design, and the miniaturization of the electronic device can be achieved.

  The electronic device of the present invention relates to an electronic device having a substrate and an FPC substrate connected to each other by a BtoB connector. Mounting electrodes to which connector terminals are connected are formed on the front side of the FPC board, and a floating pattern electrically independent of circuit wiring is formed on the back side of the FPC board. The floating pattern is formed so as to reach the outer end of the FPC board and includes a region corresponding to a terminal on the outer side of the FPC board of the connector. As a result, even if the connector is mounted just outside the outer shape of the FPC board, no sagging occurs in the FPC board, and no electrical problem occurs even if the mounting electrode and the floating pattern are short-circuited. Furthermore, the floating pattern is provided separately corresponding to each of the terminals on the outer side of the FPC board of the connector. Thereby, even if a plurality of mounting electrodes and the floating pattern are short-circuited, an electrical problem does not occur.

  An embodiment of the present invention will be described with reference to FIGS. FIG. 4 schematically shows a cross-sectional configuration of the present invention. The BtoB connector includes a connector body 2 and terminals 6, and mounting electrodes 4 are formed on the mounting surface (front surface) of the FPC board 1 so as to correspond to the terminals 6. As illustrated, the terminal 6 of the connector is mounted on the mounting electrode 4 with solder 11. On the back surface of the FPC board 1, a back pattern 5 and a floating pattern 9 are formed at positions corresponding to the terminals 6 of the connector. FIG. 5 is a perspective view of the configuration shown in FIG. 4 as seen from the back pattern surface side. The back pattern 5 functions as a wiring constituting the circuit, but the floating pattern 9 is electrically independent from the back pattern 5. Since the floating pattern 9 is formed up to the outer shape of the FPC board 1, the end of the FPC board 1 does not sag. Furthermore, since the back pattern 5 is not electrically connected to the circuit wiring, there is no electrical problem even if it contacts the front mounting electrode 4. That is, the no-pattern area A <b> 12 is provided between the back pattern 5 and the floating pattern 9. Thereby, even if one mounting electrode 4 and the floating pattern 9 are short-circuited, an electrical problem does not occur.

  Further, the floating pattern 9 is separated and provided so as to correspond to the connector terminal 6 so that adjacent mounting electrodes do not short-circuit through the floating pattern. Therefore, a non-pattern area B13 is formed as shown in FIG.

  With such a configuration, it is possible to eliminate a wasteful area of the FPC board and avoid a short-circuit between the mounting electrode and the back pattern, which has been a problem in the prior art, and a soldering failure due to sagging of the FPC board. It becomes possible.

  As electronic devices become smaller and lighter, the present invention enables the FPC board to be miniaturized. Therefore, the present invention is suitable for use in the electronic device industry where miniaturization is progressing.

It is sectional drawing which shows the cross-sectional structure of the conventional FPC board | substrate. It is sectional drawing which shows the cross-sectional structure of the conventional FPC board | substrate. It is sectional drawing which shows the cross-sectional structure of the conventional FPC board | substrate. It is sectional drawing which shows typically the FPC board | substrate by this invention. It is the perspective view which looked at the FPC board by this invention from the back pattern surface side.

Explanation of symbols

1 FPC board 2 Connector body 3 Waste area 4 Mounting electrode 5 Back pattern 6 Connector terminal 8 FPC board sagging 9 Floating pattern 10 Insulating film 11 Soldering 12 No pattern area A
13 No pattern area B

Claims (1)

An electronic device having an FPC board,
The FPC board has a BtoB connector mounted on the end,
A first terminal group is provided on the first side of the connector body of the BtoB connector, and a second terminal group is provided on the second side facing the first side,
The first terminal group is located closer to the end of the end portion than the second terminal group,
A first mounting electrode group is formed on the front surface of the FPC board so as to correspond to the first terminal group, and a second mounting electrode group is formed so as to correspond to the second terminal group. Formed,
On the back surface of the FPC board, circuit wiring and a plurality of floating patterns electrically independent from the circuit wiring are formed,
The first mounting electrode group is formed up to the end,
The circuit wiring is formed at a position corresponding to the second terminal group, and is formed apart from the plurality of floating patterns.
Each of the plurality of floating pattern is formed in a position corresponding to each of the electrodes of the first mounting electrode group, they are formed to reach to the end of said end portion, so as to be electrically independent of each other Electronic equipment characterized by being provided separately.

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