JP2008288359A - Printed circuit board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To electrically connect a printed circuit board and an extension board by substantially vertically mounting the extension board with respect to the printed circuit board, and more easily and inexpensively performing automatic soldering compared with a conventional way. <P>SOLUTION: The lower end edge of the extension board 2 is formed in projected/recessed shape with notches 3a-3c, and two projected insertion parts 4a, 4b are arranged in the lower end edge. Long holes 5a, 5b corresponding to the insertion parts of the extension board are arranged in the board surface of the printed circuit board 1. Besides, the longitudinal center lines C1, C2 of the long holes are mutually arranged by deviation not to be aligned on one straight line. The insertion parts of the extension board are inserted to the long holes of the printed circuit board, and then, the extension board is vertically fixed with respect to the printed circuit board by bending stress which is generated in the extension board when the insertion parts are inserted. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a printed circuit board in which an extension board is mounted upright on a board surface.

  In recent years, miniaturization of products has progressed, and it is often impossible to mount all necessary electronic components on the surface of a printed circuit board with a limited area. In view of this, the mounting area of the electronic component is increased by providing the printed circuit board with an expansion board.

  By the way, when an expansion board is mounted on a printed circuit board, the connection of the expansion board is usually performed using a connector. However, when the connector is used, there is a problem that the manufacturing cost increases.

  For this reason, a method of directly mounting an extension board on a printed board without using a connector has been proposed (see, for example, Patent Document 1). According to this method, the extension board is joined to the board surface of the printed board in an upright state. 4A and 4B are views showing a printed circuit board on which an extension board is mounted by this method. FIG. 4A is a perspective view and FIG. 4B is a cross-sectional view. As shown in FIG. 4, a through hole 12 having a dimension corresponding to the lower end surface of the extension board 11 is formed in the printed board 10, and is connected to the wiring 14 on the board 11 in a region near the lower end of the extension board 11. A pad 13 is provided. Then, the extension board 11 is inserted into the through hole 12 and is held upright substantially perpendicularly to the board surface of the printed board 10. The through hole 12 is filled with the solder 15, and the wiring 14 of the printed board 10 is filled. And the pad 13 of the expansion board 11 are electrically joined by soldering.

  According to this conventional method, play occurs between the expansion board and the through hole in a state where the expansion board is inserted into the through hole of the printed circuit board (the expansion board cannot be inserted without play). In order to mount the board perpendicular to the board surface of the printed circuit board, a means for holding the expansion board perpendicular to the board surface of the printed circuit board is required during soldering. As a result, there has been a problem that the mounting process of the expansion board becomes complicated, is not suitable for automation of the soldering process, and the manufacturing cost increases.

  Moreover, in order to air-cool the wiring on the printed circuit board and the electronic components mounted on the board surface, it is conceivable to form an air path using the expansion board or to function the expansion board as a heat shielding plate. In this case, the conventional method requires soldering for electrical joining between the expansion board and the printed circuit board, so that the position where the expansion board can be attached is considerably limited.

JP 2002-324960 A

  Therefore, the problem of the present invention is that the expansion board can be mounted substantially perpendicular to the printed circuit board, and that automatic soldering can be performed easily and at a lower cost than before, so that the printed circuit board and the expansion board can be electrically connected. There is to do.

  In order to solve the above problems, the present invention is a printed circuit board in which an extension board is mounted upright on a board surface, and the lower end edge of the extension board is formed in a concavo-convex shape by a notch, and 2 More than one convex insertion part is provided, and a long hole corresponding to the insertion part of the expansion board is provided on the board surface of the printed circuit board, and a longitudinal center line of the long hole is aligned on a straight line. So that the extension board is inserted into the elongated hole of the printed board, and the extension board is inserted into the extension board by the bending stress generated by the insertion. The printed circuit board is characterized by being fixed substantially vertically.

  In the above configuration, preferably, a pad is provided in a region of a lower end edge of the extension board, while a pad is provided in the vicinity of a region of the printed board on which the extension board is mounted, and the extension board is connected to the print board. The pad of the expansion board and the pad of the printed board are connected by soldering while being inserted and fixed to the board.

According to the present invention, the extension board can be fixed substantially vertically to the printed circuit board without a connection connector and without a holding step for fixing the connection board vertically. Therefore, the extension board can be mounted on the printed board very efficiently and at low cost. In addition, the air path formation and the heat shielding using the expansion board can be performed fairly freely without being restricted by soldering.
Moreover, the insertion part length from a lower end edge can be shortened by providing a recessed part in the convex insertion part both sides of the lower end edge of an extended board | substrate.
Furthermore, a pad that is not used for electrical connection between the extension board and the printed circuit board can increase the holding force for fixing as a mechanical joint.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. 1A and 1B are diagrams showing a printed circuit board according to an embodiment of the present invention, in which FIG. 1A is a plan view of an expansion board, and FIG. 1B is a plan view of the printed circuit board. As shown in FIG. 1 (A), according to the present invention, the lower end edge of the expansion board 2 is formed in a concavo-convex shape, and the notches 3a to 3c and the two convex insertion portions 4a and 4b at the lower end edge are formed. Is provided. In addition, the number of insertion parts should just be two or more.
Further, the insertion portions 4 a and 4 b of the extension board 2 are provided with pads 6 a that connect to the wiring formed on the extension board 2.

Further, as shown in FIG. 1B, long holes 5a and 5b corresponding to the insertion portions 4a and 4b of the extension board 2 are provided on the board surface of the printed circuit board 1, and the long holes 5a and 5b are elongated. The direction center lines C1 and C2 are arranged so as to be shifted from each other (shift length S) so as not to align on a straight line.
Further, pads 7a connected to the wiring formed on the printed circuit board 1 are provided at the edge portions of the long holes 5a and 5b on the back surface of the printed circuit board 1 (see FIG. 2B).

2A and 2B are diagrams showing a state in which the expansion board shown in FIG. 1A is mounted on the printed board shown in FIG. 1B. FIG. 2A is a perspective view, and FIG. It is the top view seen from the back side. As shown in FIG. 2, the insertion portions 4 a and 4 b of the extension board 2 are inserted into the long holes 5 a and 5 b of the printed board 1, respectively. At this time, a bending stress is generated in the extension board 2, and by this stress, a part of each insertion part 4a, 4b of the extension board 2 is engaged with a part of the corresponding long hole 5a, 5b. The insertion portions 4a and 4b are securely fixed in the corresponding long holes 5a and 5b, and the expansion board 2 is fixed vertically to the printed board 1. At the same time, the pad 6a of the extension board 2 and the pad 7a of the printed board 1 are aligned. Then, the corresponding pads 6a and 7a of the expansion board 2 and the printed board 1 are electrically joined to each other by soldering.
In this embodiment, the pad is provided on one side of the expansion board, but a double-sided board in which pads are provided on both sides of the expansion board may be used.

  Thus, according to the present invention, the expansion board 2 can be mounted substantially perpendicularly to the printed circuit board 1 simply by inserting the insertion portions 4 a and 4 b of the expansion circuit board 2 into the long holes 5 a and 5 b of the printed circuit board 1. can do. Accordingly, a pad connected to the wiring formed on the extension board 2 is provided in the area of the lower end edge of the extension board 2, while the printed board has a printed board in the vicinity of the area where the extension board 2 is mounted on the board surface of the printed board 1. By providing a pad to be connected to the wiring formed on 1, the expansion board 2 is fixed to the printed board 1, and then the expansion board 2 and the printed board 1 are easily electrically connected by automatic soldering. Can do. Further, the degree of freedom in forming the air path and shielding the heat by the expansion board 2 is increased.

[Example]
Next, the printed board and the extended board shown in FIG. 1 were produced, and the extended board was mounted on the printed board.
Cutouts 3a to 3c and two insertion portions 4a and 4b were formed on the extended substrate 2 having a thickness of 1.6 mm.
Two elongated holes 5a and 5b were formed on the printed board 1 having a thickness of 1.6 mm. Each of the two long holes 5a and 5b has a width of 1.65 mm, and is arranged with a distance d1 = 3 mm from each other, and the total length d2 of the two long holes 5a and 5b including the distance d1. = 21 mm. Further, the longitudinal central axes C1 and C2 of the two long holes 5a and 5b are shifted from each other by a length S. And what changed the length S of the shift | offset | difference in 0.05 mm increments within the range of 0.1 mm-0.7 mm was produced one by one, and the good and bad of mounting were investigated.
As a result of mounting, when the deviation S between the two long holes 5a and 5b was 0.45 mm, the expansion board was most easily inserted and the expansion board was most firmly fixed to the printed board. A preferable range of the deviation S was 0.30 mm to 0.60 mm. If it is less than 0.30 mm, the extension board is inclined, and if it exceeds 0.60 mm, it is difficult to insert the extension board.

  3A and 3B are diagrams showing a printed circuit board according to another embodiment of the present invention, in which FIG. 3A is a plan view of the expansion board, and FIG. 3B is a plan view of the printed circuit board on which the expansion board is mounted as viewed from the back side. (C) is a longitudinal sectional view of a printed circuit board on which an expansion board is mounted. In the embodiment of FIG. 3, in the embodiment of FIGS. 1 to 2, an expansion board and a printed board are provided with pads for mechanical joining in addition to pads for electrical connection.

According to this embodiment, referring to FIG. 3, the pad 6a connected to the wiring formed on the extension board 2 is provided in the insertion portion 4a of the extension board 2 (see FIG. 3A). A pad 7a connected to the wiring formed on the printed board 1 is provided on the edge of the corresponding slot 5a on the back surface of the printed board 1 (see FIG. 3B). Further, a pad 6b for mechanical joining is provided on the insertion portion 4b of the extension board 2 (see FIG. 3A), while a machine is provided on the edge of the corresponding slot 5b on the back surface of the printed board 1. A pad 7b for mechanical bonding is provided (see FIG. 3B).
Note that the pad shape for mechanical joining may be rectangular, semicircular, etc., as long as it has an area necessary for solder joining. Further, the pads other than the electrically connected pads may be used as mechanical bonding pads to increase the bonding strength.

Then, the insertion portions 4a and 4b of the extension board 2 are inserted into the elongated holes 5a and 5b of the printed circuit board 1, so that the extension board 2 is fixed substantially perpendicularly to the printed circuit board 1 and the pads 6a of the extension board 2 and The pads 7 a of the printed circuit board 1 are electrically connected by the solder 8, and the pads 6 b of the expansion board 2 and the pads 7 b of the printed circuit board 1 are firmly bonded to each other by the solder 8.
Thus, according to the present invention, no means for holding the expansion board 2 with respect to the printed circuit board is required during soldering, and automatic soldering can be easily performed.
In FIG. 3C, the pad is formed on one side of the expansion board, but a double-sided board in which pads are provided on both sides of the expansion board may be used.

It is a figure which shows the printed circuit board by one Example of this invention, (A) is a top view of an expansion board, (B) is a top view of a printed circuit board. 2A is a diagram illustrating a state in which the expansion board illustrated in FIG. 1A is mounted on the printed circuit board illustrated in FIG. 1B, where FIG. 1A is a perspective view and FIG. FIG. It is a figure which shows the printed circuit board by another Example of this invention, (A) is a top view of an expansion board, (B) is the top view which looked at the printed circuit board with which the expansion board was mounted from the back surface side, (C) FIG. 4 is a longitudinal sectional view of a printed circuit board on which an expansion board is mounted. It is a figure which shows the printed circuit board with which the expansion board was mounted by the conventional method, (A) is a perspective view, (B) is sectional drawing.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Printed circuit board 2 Expansion board 3a-3c Notch 4a, 4b Insertion part 5a, 5b Slot 6a, 6b Pad 7a, 7b Pad 8 Solder

Claims (2)

The expansion board is a printed circuit board mounted upright on the board surface,
The lower end edge of the extension board is formed in a concavo-convex shape by a notch, and two or more convex insertion parts are provided on the lower end edge, and the board surface of the printed board corresponds to the insertion part of the extension board And the longitudinal center line of the elongated hole is shifted from each other so as not to be aligned in a straight line, and the insertion portion of the expansion board is inserted into the elongated hole of the printed circuit board. The printed circuit board, wherein the expansion board is fixed substantially perpendicularly to the printed circuit board by bending stress generated in the expansion board.   While a pad is provided in the area of the lower edge of the extension board, a pad is provided in the vicinity of the area where the extension board of the printed board is mounted, and the extension board is inserted into the printed board and fixed. The printed circuit board according to claim 1, wherein the pad of the expansion board and the pad of the printed circuit board are connected by soldering.

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