JP2909372B2 - Sub printed board retaining structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for retaining a sub printed board mounted in parallel with a mother printed board via a stacking connector.

[0002]

2. Description of the Related Art In a thin electronic device whose external dimensions are restricted, for example, a personal computer such as a notebook type, a book type, a laptop type or an OA device, the entire circuit is formed by a single printed circuit board due to a limited area of the printed circuit board. When a sub-printed board cannot be mounted on the main printed board or when an optional printed board for adding functions is provided, the sub-printed board is mounted in parallel with the main printed board using a stacking connector.

For example, in the case of a notebook personal computer, the vertical and horizontal dimensions are restricted to dimensions such as A4 or B4, and the thickness thereof must be as small as possible. Since the power supply unit and the disk drive unit are also housed in the housing of the device, the size of the printed circuit board is naturally limited. For example, when it is desired to mount the circuit on a printed circuit board for additional mounting, a circuit is mounted on the main printed circuit board and the sub printed circuit board, and the two printed boards are connected by a stacking connector.

In this case, there is a possibility that the stacking connector may be loosened or pulled out due to vibration during use or transportation. As a structure to prevent this, if the sub-printed board is held down by the main body case, in the case of a notebook computer, etc., the base plate of the keyboard (plate holding contacts) is located above the sub-printed board. Thus, a structure in which the sub-printed board is pressed by the base board is obtained. However, in such a structure, the vibration at the time of the key operation is transmitted to the sub-printed board via the base board, resulting in poor contact or breakage of the connector.

Therefore, as a structure for preventing the stacking connector from falling off, a structure in which a member for holding the sub-printed board is fixed to the main printed board is adopted.

FIG. 6 is a view showing a conventional structure for preventing a stacking connector from coming off. A connector 3a for connecting the sub-printed board 2 is mounted on the upper surface of the main printed board 1, and a screw hole 51 is formed in an outer portion of the connector.
Is provided. On the sub-printed board 2, a connector 3 b to be fitted with the connector 3 a of the main printed board is mounted on the lower surface during mounting.
b, the sub-printed board 2 is connected to the main printed board 1.

[0007] A retaining metal fitting 54 having a holding frame 52 and a fixing leg 53 is put on the mounted sub-printing board 2, and a screw 56 is screwed through a screw insertion hole 55 provided in the fixing leg 53. The fastening to the hole 51 prevents the stacking connector 3 from coming off.

[0008]

However, the conventional structure as shown in FIG. 6 has a problem in that it is expensive to manufacture the retaining fitting 54, and the retaining fitting 54 hinders high-density mounting of the main printed board. There was a problem.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a technical means for preventing a sub-printed board connected by a stacking connector from being loosened or removed with a simpler structure.

[0010]

According to the present invention, a plurality of solderable pins 41 which are inserted into the through holes 11 of the main printed board 1 are provided at the base end, and are located at positions near the front end or the front end of the intermediate portion. The above-described problem is solved by soldering a plurality of metal retaining plates 4 and 4a having a spring property and having a holding projection 43 to the main printed board 1 in advance.

A plurality (usually two) of retaining plates 4, 4a
Is set in accordance with the size of the sub-printed board 2 to be mounted, and the dimension C from the base of the pin 41 at the base end of the retaining plate to the lower surface of the holding projection 43 is the same as when the fitting is performed. The height is the sum of the height D of the stacking connector 3 and the thickness t of the sub-printed board.

Each of the retaining plates 4 and 4a is mounted by inserting the pin 41 at the base end thereof into the through hole 11 of the main printed circuit board 1 and soldering it to the pattern of the main printed circuit board together with the connector 3a. Is done. Step surface 42 that contacts main printed board 1 at the base of pin 41
Is as small as possible. If the interval between the pins 41 (usually two pins) is as wide as possible, the retaining plates 4 and 4a can be stably held. The base end of the retaining plate between the pins 41, 41 is cut off slightly higher, and the retaining plate 4,
The portion between the pins 41 of 41a is the main printed board 1
It is reasonable to adopt a structure that does not come into contact with the surface.

The step surface 42 which contacts the surface of the main printed board 1 may be formed outside or inside the pin 41.

When the number of the stacking connectors 3 for connecting the sub-printed board 2 is one, the receiving protruding piece 45 is separated from the base end side of the holding protruding piece 43 by the thickness t of the sub-printed board.
Is used.

The shapes of the holding projection 43 and the receiving projection 45 are as follows.
Any shape may be used as long as it can restrict the movement of the sub-printed board 2 in the thickness direction.
A structure in which a metal plate is bent by a press or the like to form the holding protrusion 43 and the receiving protrusion 45 is rational.

Further, the pins 41 of the retaining plate are soldered and mounted on the ground pattern of the main printed board 1, and the ground pattern 21 is provided on the periphery of the upper surface of the sub-printed board 2 facing the pressing projection 43. Thus, it is possible to connect the ground patterns of the main printed board 1 and the sub-printed board 2 to each other via the retaining plates 4 and 4a to obtain a signal ground.

If necessary in terms of the balance between solderability and elasticity, the base ends of the retaining plates 4 and 4a are formed of a metal plate having good solderability, and the holding projection 43 is provided. A structure in which a metal plate having excellent spring properties is fixed by a rivet or the like may be employed.

[0018]

The retaining plates 4 and 4a hold the pins 41 by inserting them into the through holes 11 of the main printed board, and simultaneously connect the pins 41 to the main printed board by solder dip or the like at the same time as the connector 3a and other soldering parts. Solder to pattern 1 and fix. When the sub-printed board 2 is mounted on the main printed board 1, the retaining plates 4, 4a
And press the sub printed circuit board 2 so as to overlap the main printed circuit board 1 to connect the connector 3b on the sub printed circuit board side to the connector 3a on the main printed circuit board side.

Depending on the shape of the holding projection 43, when the sub printed board 2 is pushed into the main printed board 1,
The retaining plates 4, 4a which are pushed by the periphery of the sub-printing plate 2
Can be expanded (see FIG. 5).

When the connectors 3a and 3b of the main printed board and the sub printed board are connected to each other, the sub printed board 2
Enters under the presser projection 43, and the retaining plates 4, 4a return by their own elasticity. In this state, the connectors 3a, 3b
Is prevented by the contact between the lower surface of the holding projection 43 and the upper surface of the peripheral edge of the sub-printed board 2.

In the case where the signal ground is formed via the retaining plates 4 and 4a, the sub-printed board 2 is brought into contact with the ground pattern 21 provided on the peripheral edge of the sub-printed board and the lower surface of the holding projection 43. Is connected to the ground pattern on the main printed board 1 via the retaining plates 4 and 4a.

When the number of connectors for connecting the sub-printed board is one, the retaining plates 4 and 4a for holding the sides of the sub-printed board on which the connector is not provided are provided with receiving projections 45. Used. Receiving projection 45 and holding projection 4
According to the retaining plates 4, 4 a provided with 3, when the stacking connector 3 is connected, the side of the sub-printed board 2 enters between the receiving projection 45 and the holding projection 43. Therefore, it is possible to prevent the sub printed board 2 from falling or vibrating around the mounting portion of the connector 3b.

The retaining plates 4, 4a are connected to the main printed board 1
The through hole 11 provided in the main printed board for mounting on the main printed board is much smaller than the screw hole 51 provided in the main printed board for mounting a conventional retaining fitting, and abuts on the surface of the main printed board 1. Since the step surface 42 of the retaining plate also contacts the main printed board 1 with a much smaller area than the leg 53 of the conventional retaining fitting 54,
The area in which the patterns or components of the main printed board 1 cannot be mounted, which is caused by mounting the retaining plates 4, 4a, can be made much smaller than in the conventional structure, and the mounting density of the main printed board can be increased accordingly.

[0024]

FIG. 1 shows a first embodiment of the present invention. The main printed board 1 is provided with a through hole 11 for mounting the retaining plate 4 at a portion outside the mounting position of the connector 3a for mounting the sub printed board. A ground pattern of the main printed board 1 is provided on the surface of the main printed board 1 provided with the through holes 11 on the back side in the drawing.

The retaining plate 4 is made by punching and bending a metal plate having solderability and spring property by a press, and has two pins 41 at the base end on the main printed board 1 side.
Reference numerals 41 are provided at intervals corresponding to the intervals between the through holes 11 of the main printed board. A small step surface 42 is provided on the outside of the pins 41, 41,
The portion between the pins 41 and 41 is cut slightly higher, and when the pins 41 are inserted until the stepped surface 42 contacts the surface of the main printed board 1, the portion between the pins 41 and 41 and the surface of the main printed board 1 are cut. Is formed between them.

The holding protrusion 43 is formed by bending the upper end portion of the middle portion of the retaining plate 4 into a U-shaped side surface, and the lower surface 44 of the holding protrusion and the step surface at the base of the pin 41 are formed. The distance C between the sub-printed board and the sub-printed board is substantially equal to the height D of the stacking connector 3 in the fitted state plus the thickness t of the sub-printed board (see FIG. 2). Lower surface 4 of presser foot
4 is slightly inclined so that the protruding side of the protruding piece 43 is slightly higher, and when the edge of the sub-printed board 2 is fitted under the pressing protruding piece 43 as shown in FIG. The sub-printed board 2 can be pressed down by the action.

A connector 3b, which is connected to the connector 3a of the main printed board, is mounted on the sub-printed board 2 on which the optional circuit and the like are mounted, on a surface facing the main printed board 1 at the time of mounting. Further, the ground pattern 21 of the sub-printed board is provided on an edge adjacent to the connector 3b on the side opposite to the main printed board when the sub-printed board 2 is mounted.
Is provided.

When the sub-printed board 2 is mounted, the connectors 3a and 3b are aligned, and the sub-printed board 2 is pressed against the main printed board 1 while the retaining plates 4 and 4 are pushed outward and expanded. , 3b. When the connectors 3a and 3b are fitted, as shown in FIG. 2, the retaining projection 43 of the retaining plate locks the edge of the sub-printed board 2 and the upper side of the sub-printed board 2 (the connectors 3a and 3b).
b) (the loose side of b).

At this time, the lower surface 44 of the retaining projection of the retaining plate
Is in contact with the ground pattern 21 of the sub-printed board, and because the retaining plate 4 is soldered to the ground pattern of the main printed board 1, the ground pattern between the sub-printed board 2 and the main printed board 1 is different. Connection (signal ground) is made.

The signal ground of the sub-printed board 2 is
In many cases, the connection is performed via the stacking connector 3. However, since a large number of connector contacts are used to connect the ground patterns to reduce the contact resistance, the number of contact pins of the stacking connector 3 increases. In the structure of the present invention, if the signal ground of the sub-printed board is taken via the retaining plate 4, the number of contacts of the stacking connector 3 can be reduced, the cost is reduced, and the size of the stacking connector is reduced. Accordingly, the mounting density of the wiring patterns and components of the printed boards 1 and 2 can be increased.

FIGS. 3 and 4 show a second embodiment of the present invention, in which a holding structure is provided as a retaining structure for a sub-printed board 2 mounted via one stacking connector 3. FIG.
A retaining plate 4a having a projection 43 and a receiving projection 45;
This shows a structure in which the sub-printed board 2 is held by the retaining plate 4 provided with only the holding protrusion 43. Receiving prong 4
As shown in FIG. 3, the retaining plate 4 a having the protrusions 5 is provided with a holding protruding piece 43 and a receiving protruding piece 45 bent in a U-shaped side surface at an interval E slightly larger than the thickness t of the sub-printed board. Yes, the side of the sub-printed board on which the connector 3b is not mounted is held so as to be sandwiched between the holding projection 43 and the receiving projection 45, and the inclination of the sub-printed board 2 together with the loosening of the stacking connector 3 And vibration are prevented.

FIG. 5 is a view showing a third embodiment of the retaining plate. In the third embodiment, the upper portion and the base end of the retaining plate are formed of metal plates made of different materials. . Pin 4
The base member provided with 1 is made of a metal plate having more excellent solderability, and the upper portion on which the holding projection 43 is formed is made of a metal plate having excellent spring properties. doing. The holding projection 43 is formed by folding the upper part of the retaining plate into a V shape.

According to the structure of the third embodiment, when the sub-printed board is pressed to connect the sub-printed board to the main printed board, the edge of the sub-printed board becomes the upper slope 47 of the holding projection 43. When the end side of the sub-printed board enters under the holding protrusion 43, the retaining plate 4 is returned by its own spring force, and the holding protrusion 43 is pressed. The lower edge 44 locks the upper side edge of the sub-printed board 2 to prevent the stacking connector 3 from coming off.

[0034]

According to the structure of the present invention described above,
The structure of the retaining parts is simple and can be manufactured at low cost, and the number of steps required to mount them on the main printed board is extremely small, and the retaining when mounting the sub printed board can be done with one touch. Man-hours for manufacturing and assembling parts required for retaining the sub-printed board can be greatly reduced.

Further, since the area where wiring or components cannot be mounted on the main printed board caused by fixing the parts for retaining to the main printed board is much smaller than that of the conventional structure, the mounting density of the main printed board is increased. can do. Furthermore, since the signal ground of the sub-printed board can be taken through the retaining parts of the sub-printed board, the number of contacts of the stacking connector can be reduced, and the connector can be made small and inexpensive. There is an effect that the mounting density of the board can be further increased.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a first embodiment.

FIG. 2 is a side view of a main part of the first embodiment.

FIG. 3 is a perspective view of a retaining plate according to a second embodiment.

FIG. 4 is a side view of a main part of the second embodiment.

FIG. 5 is a perspective view of a third embodiment of a retaining plate.

FIG. 6 is an exploded perspective view showing an example of a conventional structure.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Main printed board 2 Sub printed board 3 Stacking connector 4 Retaining plate 4a Retaining plate 41 Pin 43 Holding rod 44 Lower surface of holding protruding piece t Sub-printing board thickness

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H01R 9/09 H01R 13/639 H01R 23/68 303 H05K 1/14

Claims (3)

(57) [Claims] 1. A plurality of pins (41) provided at a base end and a presser protruding piece (43) protruding from one surface thereof, and a lower surface (44) of the presser protruding piece from the root of the pin (41). Up to the height (D) of the mating stacking connector (3) with the thickness (t) of the sub-printed board added. (4,4a) is the opposite side of the sub-printed board (2)
With the presser protruding piece (43) facing at an interval,
1) is inserted into the through hole (11) of the main printed board (1) and soldered to the printed pattern of the main printed board (1), and is connected to the main printed board (1) via the stacking connector (3). A retaining structure for a sub-printed board, characterized in that an upper side edge of the connected sub-printed board (2) is locked by a lower surface (44) of a holding projection (43) of the retaining plate. 2. A sub-printing board (2) is locked by a plurality of retaining plates (4, 4a), and at least one of the sub-printing boards (4, 4a) is attached to a base end side of a holding projection (43). The retaining structure for a sub-printed board according to claim 1, wherein the receiving projection (45) is provided at a distance of the plate thickness (t). 3. The retaining plate (4) is a main printed board (1).
3. The sub-printing according to claim 1, wherein the sub-printing board is soldered to the ground pattern, and the ground pattern (21) is provided on a peripheral portion of an upper surface of the sub-printing board (2) which faces the pressing protrusion (43). Retaining structure of board.