HK1052087A - Connective structure for coupling printed circuit boards - Google Patents

Description

Connection structure of printed circuit board

Technical Field

The present invention relates to a connection structure for connecting printed circuit boards facing each other.

Prior Art

In order to connect two mating printed circuit boards 1 and 2 together, a male connector 3 provided on one of the circuit boards 1 (hereinafter referred to as a first circuit board) has been mounted on a female connector 4 provided on the other circuit board 2 (hereinafter referred to as a second circuit board) in a manner of "lug-in-groove" as shown in fig. 13 (a). In this case, one of the first and second printed circuit boards 1, 2 must be tilted in order to visually check the correct position of the male and female connectors 3, 4. This operation often or sometimes causes one connector 3 to "pry" or twist relative to the other connector 4, resulting in a defective mounting engagement.

In spite of the above problems, it is recently desired to minimize the stacking distance between the printed circuit boards 1 and 2 stacked on each other. Accordingly, the male connector 3 and the female connector 4 have been made low in height in order to join the circuit boards. Even if one circuit board 1 is tilted as shown in fig. 13(b), such a shorter connector has made it more difficult to visually check its relative position. One effective connection length (perpendicular to the circuit board) of these connectors has been reduced to the point where reliability of their electrical connections is compromised.

It has been proposed in japanese patent laid-open No. 8250240 to hopefully solve the above problem of the shortening of the connection length due to the miniaturization of the connector, and to provide an improved connector. According to this proposal, an opening wide enough to receive a male connector (i.e., a header) is formed in a printed circuit board, wherein the surface of the circuit board not facing another circuit board is used for mounting an electric appliance and the like. However, such a connection structure, which is intended to promote more stable engagement of two printed circuit boards facing each other, does not solve the problem of "prying" or distortion of the connector. The male and female connectors that mate with each other may occasionally be misaligned with each other, resulting in the housings colliding with each other. In this case, a large stress is applied to the soldering portion (i.e., the head portion) of the male connector on which the electric appliance or the like is surface-mounted. As a result, there is a high possibility that cracks are seriously generated at the soldered portion, so that a stable electrical connection cannot be formed.

Disclosure of Invention

The present invention addresses the shortcomings inherent in prior art connection structures. It is an object thereof to provide an improved connection structure for connecting two printed circuit boards facing each other, whereby a stable protection can be provided to the portion of the connection structure, so that it does not deform to engage even when the distance between the two circuit boards is reduced, thereby establishing a stable electrical connection.

In order to achieve the above object, the present invention provides a connecting structure for connecting two printed circuit boards facing each other, wherein the connecting structure includes a male connector provided on a first circuit board surface and a female connector also provided on a second circuit board surface so as to be mounted on the male connector. The female connector has a housing and a plurality of alignment pins extending from opposite side ends of the housing toward the first printed circuit board. Each of the positioning pins has a free end protruding out of the top of the housing, and a plurality of positioning slots are formed in the first printed circuit board so that the positioning pins are inserted into the slots to precisely connect the male and female connectors in their positions.

Preferably, the male connector may be thin and fixed in an opening formed in the first circuit board so as to be disposed on a free surface thereof not facing the second circuit board.

The positioning pin passing through the slot preferably has a height protruding from the free surface so that the exact fitting of the male connector and the female connector can be visually checked.

It is possible that the male connector on the first circuit board has an end region of the housing which overlaps the positioning slot. In this case, a guide hole coinciding with the positioning slot can be formed in the end region. Each guide pin passing through the slot is exposed in the guide hole for visual inspection of the guide pin.

Preferably, a base end of each alignment pin may extend downwardly from the bottom of the housing of the female connector to serve as another alignment pin to accurately position the female connector relative to the second circuit board.

In any case, the locating pins are simultaneously made integral with the female connector, or alternatively made as a single piece from metal, for subsequent insert molding with or pushing into the housing.

Brief description of the drawings

FIG. 1 is a front view of a connection structure of the present invention for connecting two printed circuit boards facing each other, wherein the structure is mainly shown in a sectional view;

FIG. 2 is a cross-sectional view taken along line 2-2 of FIG. 1;

FIG. 3 is a top view of a male connector constituting the connection structure of FIG. 1;

FIG. 4 is a cross-sectional view taken along line 4-4 of FIG. 3;

FIG. 5 is a cross-sectional view taken along line 5-5 of FIG. 3;

fig. 6 is a perspective view of the male connector as viewed looking down;

fig. 7 is a perspective view of the male connector looking upward;

fig. 8 is a plan view of a female connector also constituting the connection structure of fig. 1;

FIG. 9 is a cross-sectional view taken along line 9-9 of FIG. 8;

FIG. 10 is a cross-sectional view taken along line 10-10 of FIG. 8;

fig. 11 is a perspective view of the female connector as viewed downwardly;

fig. 12 is a perspective view of the female connector looking upward;

fig. 13(a) shows a prior art connection structure for connecting two printed circuit boards facing each other, wherein the two circuit boards are spaced apart from each other by a long distance;

fig. 13(b) shows a prior art connection structure for connecting two printed circuit boards facing each other, wherein the two circuit boards are spaced apart from each other by a short distance.

Description of the preferred embodiments

Some embodiments of the invention will now be described with reference to the accompanying drawings.

Fig. 1 and 2 show a connection structure according to the invention for connecting two printed circuit boards 11, 12 facing each other. A male connector 13 provided on the surface of the circuit board 11 is to be mounted on a female connector 14 also provided on the surface of the other circuit board 12 to establish electrical connection between the printed circuit boards.

As shown in fig. 3-7, the male connector 13 includes an insulative housing 15 and a plurality of first contacts 21 secured thereto. A cavity 16 having an open bottom and formed in the housing defines the housing as an elongated parallelepiped-shaped box. Around the open bottom of the cavity 16 is a flange 17 located below the casing 15, whose corresponding end region has a guide hole 18 free to receive a positioning pin 35. These pins extend from the female connector 14 in a manner described in more detail below. Each respective end 15a of the housing has an upper cutout portion and an alignment lug 19 depending from the bottom of the portion. Reference numeral 20 denotes a reinforcing metal embedded in the lower horizontal edge of the corresponding end portion 15a and serving to play an important role in surface mounting the connector. The generally L-shaped contacts each include a vertical portion 22 and a laterally extending lead 23. The vertical portions 22, the lower ends of which are bent to form the leads 23, are all arranged at regular intervals along the wall defining the main side of the cavity 16 of the housing 15. These vertical portions 22 fixed to one wall face the corresponding portions 22 fixed to the other wall opposite to the one wall. Each wire 23 is bent up and down in and along a guide groove formed inside the flange 17 and along the underside of the housing 15. The outer ends of the wires 23 extend laterally beyond the lower and outer edges of the housing.

The male connector 13 of the above construction is mounted on the surface of the upper printed circuit board 11 which has an opening 25 to receive the flange 17 of the housing. The circuit board 11 also has a locating slot 26 and an alignment hole 27, wherein the locating slot 26 is mounted on a respective locating pin 35 (described in detail below) extending from the female connector 14 and the alignment hole 27 closely receives the alignment lug 19 (see fig. 1). Mounting of the connector 13 on the surface of the circuit board 11 is accomplished by engaging the flange 17 within the opening 25 and then soldering the wires 23 of each contact to the back surface of the circuit board that does not face the underlying circuit board (see fig. 2). Two reinforcing metals 20 are also soldered to the back surface of the circuit board 11, thereby improving the resistance of the male connector 13 against detachment.

On the other hand, the female connector 14 also includes an insulative housing 31 and a plurality of second contacts 41 tightly fixed to the housing. The generally inverted T-shaped housing 31 includes a base 32 and a contact frame 33 upstanding from a central region of the base such that contacts 41 are secured to both sides of the contact frame 33. Further, a plurality of guide slots formed perpendicularly on each side of the contact holder extend to the base 32 to provide a plurality of thin and deep grooves 23 to receive the contacts 41 and to insulate them from each other. Two positioning pins 35, which stand upright on the base part 32 at corresponding end regions, extend parallel to the central contact frame 33. In the illustrated embodiment, the positioning pins 35 have been previously made as a single component by machining a metal wire, and are not initially formed integrally with the housing 31. A short lower extension 36 continuing from the lower end of each locating pin is then forced into a hole 37 formed in base 32, as shown in fig. 10, thereby securing locating pin 35 in place. One tapered top portion 35a of each alignment pin 35 projects upwardly above the top of each contact frame 33. The downward extension 36 projecting downward from the bottom of each base 32 will act as a pin to position the female connector 14 when it is mounted onto the surface of the printed circuit board 12 (see fig. 1). This positioning pin 35 may be integral with the housing 31. The generally L-shaped contacts 41 each include a vertical portion 42 and a laterally extending lead 43, wherein the vertical portions 42 are each bent at their lower ends to form the lead 43. The upper end portions of these vertical portions 42 are bent outward to form elastic contact tips 42 a. As shown in fig. 9, these contacts 41 are fixed in the thin and deep grooves 34 so as to be spaced apart from each other when arranged along both sides of the center contact frame 33. The portion of the resiliently bent tip 42a of each contact projects laterally a small distance from the contact carrier 33. The wire sites 43 extend laterally along the underside of the base 32 and project from the side edges of the base.

The female connector 14 of the above-described structure is disposed on the upper surface of the lower circuit board 12 facing the upper circuit board before the electric wire portions 43 are soldered to the circuit board 12, and thus mounted on the surface of the circuit board.

In the mutual electrical connection operation of the printed circuit boards 11 and 12, the former circuit board 11 on which the male connector 13 is mounted is placed on the latter circuit board 12 on which the female connector 14 is mounted. Next, the positioning slots 26 formed on the printed circuit board 11 will be aligned with the positioning pins 35 fixed on the female connector 14. In this state, the guide holes 18 in the housing 15 of the male connector 13 communicate with the corresponding positioning slots 26, so that the positioning pins 35 can be seen through the guide holes 18 when the operator views the male connector downward. The operator is thus no longer required to bend the upper circuit board 11 in order to check the mutual position of the male connector 3 and the female connector 4. The circuit boards 11 and 12 can now be fixed parallel to each other during the correct alignment of the connectors 3 and 4. After the tapered tops 35a of the alignment pins enter the corresponding slots 26 of the circuit board 11 and thereby register the connectors with each other, the center contact frame 33 of the female connector housing 3 will engage in the cavity 16 formed in the male connector housing 15. As a result, the vertical portion 22 of the contact 21 will be electrically contacted to the mating contact portion 42 at its resilient contact end 42a against resilient resistance. When the connectors 3 and 4 are accurately connected as shown in fig. 1 in the above-described manner, (the top portions of) the positioning pins 35 are exposed in the upper opening area of the guide holes 18 formed in the housing 15 of the male connector 3, so that the accurate connection between the connectors and between the circuit boards is visually checked. Such a visual inspection is more easily accomplished if the positioning pin 35 is designed such that its top portion protrudes from the guide hole 18.

In summary, the "pin/slot" connection structure of the present invention makes it possible to accurately and easily align the male connector 13 and the female connector 14 with each other, while the two printed circuits can be maintained in accurate positions in parallel with each other. This securely protects the connectors from distortion when they are mounted to each other, while it is now possible to visually check whether they are fully correctly connected to ensure a reliable electrical connection.

Claims (7)

1. A connecting structure of a printed circuit board which connects two first and second printed circuit boards facing each other by engaging a male connector provided on a first circuit board surface and a female connector provided on a second circuit board surface,

wherein the female connector has a housing and a plurality of positioning pins extending from opposite side ends of the housing toward the first printed circuit board, and each positioning pin has a free end protruding from a top of the housing, and a plurality of positioning slots are formed in the first printed circuit board to receive the positioning pins, and the positioning pins are inserted into the slots, so that the male connector and the female connector are accurately engaged with each other in their positions.

2. The connection structure according to claim 1, wherein the male connector is fixed in an opening formed on the first circuit board so as to be disposed on a free surface thereof not facing the second circuit board, and the female connector is fixed on the second circuit board so as to be disposed on a surface thereof facing the first circuit board.

3. A connection according to claim 1 or 2, wherein said pin passing through said slot has a height projecting from said free surface.

4. A connection arrangement according to claim 1, 2 or 3, wherein a guide hole coinciding with the positioning slot is formed in the region of the end of the housing constituting the male connector, such that the positioning pin is exposed in the guide hole through the end of the slot.

5. A connection arrangement according to any of claims 1-4, characterized in that a basic end of each alignment pin projects downwards from the bottom of the housing of the female connector to serve as another alignment pin of the female connector with respect to the second circuit board.

6. A connection according to any of claims 1-5, characterized in that the alignment pins are simultaneously made integral with the female connector.

7. A connection according to any of claims 1-5, wherein the locating pin is formed as a single piece from metal for subsequent insert moulding or pushing into the housing.