WO1998024156A1

WO1998024156A1 - Circuit board connector

Info

Publication number: WO1998024156A1
Application number: PCT/US1997/021505
Authority: WO
Inventors: Ping Chen
Original assignee: The Whitaker Corporation
Priority date: 1996-11-25
Filing date: 1997-11-20
Publication date: 1998-06-04
Also published as: JP3244440B2; JPH10154537A; AU5455398A

Abstract

The present invention provides a circuit board connector which has a low profile and which occupies a small area on a circuit board without having any effect on the insertion of mating connectors even in cases where screws of which the length of the threaded section is greater than the combined total of the thickness of the lower wall of the housing and the thickness of the circuit board are used. The housing (10) of the connector (1) has latching surfaces on the inside of the upper wall (16) which forms the cavities (14) into which mating connectors are inserted. Furthermore, screw-attachment sections (26) which have holes (28) that accommodate screws (5) used to fasten the connector (1) to the circuit board are formed as integral parts of the housing (10) on the underside of the rear wall (12) of the housing (10). The front walls (30) which delineate the holes (28) are thicker than the opposite rear walls (32). When the screws (5) are screwed into the holes (28), the rear walls (32) expand slightly; accordingly the screws (5) move rearward so that there is no protrusion of the screws (5) into the interiors of the cavities (14).

Description

CIRCUIT BOARD CONNECTOR FIELD OF THE INVENTION

The present invention relates to a circuit board connector which connects external circuits with circuits formed on circuit boards such as printed circuit boards and the like.

BACKGROUND OF THE INVENTION Connectors are widely used for the purpose of connecting devices such as electronic control units (ECUs) mounted in vehicles such as automobiles, with other electronic or electrical devices. With the diversified functions and increased performance of such devices in recent years, there has been an increase in the number of electrical contacts in such connectors; at the same time, there has been a conflicting demand for a decrease in the area occupied by such connectors on the circuit boards to which these connectors are attached, or for a reduction in the size of the connectors themselves. The circuit board connector 100 shown in Figures 6 and 7 has been proposed as a connector which is able to meet such requirements as disclosed in Japanese Utility Model Application No. 5-48273.

In the housing 110 of connector 100, latching surfaces 116, which latch the latching arms (not shown) of mating connectors, are located on the inside surface, i. e., the bottom surface 114, located on the circuit board 102 side of cavities 112 which receive the mating connectors. Furthermore, screw attachment sections 122 are disposed in thick bottom walls 118 which are adjacent to the anchoring members 116, or in partition walls 120 which are located between the cavities 112. Accordingly, since the screw attachment sections 122 do not protrude beyond the projected area of the connector 100 on the circuit board 102, the area occupied by the connector 100 on the circuit board 102 can be reduced. In the case of connector 100, there is no problem as long as the length of the threaded portions 106 of the screws 104 which fasten the connector 100 to the circuit board 102 is greater than the combined total of the thickness of the thick bottom walls 118 of the connector 100 and the thickness of the circuit board 102. However, in cases where the thickness of the thick bottom walls 118 of the connector 100 is reduced (e. g., in order to achieve a low configuration) , there is danger that the tip ends of the screws 104 will pass through the thick bottom walls 118 and protrude into the interiors of the cavities 112, thus interfering with the insertion of the mating connectors.

Furthermore, in order to form the holes 124 of the screw attachment sections 122, three release holes 126,

128 and 130 are formed in thick bottom walls 118 by means of dies (not shown) which advance from opposite directions. Accordingly, the screws 104 which are inserted into the holes 124 are subjected to a rotational moment in the clockwise direction by the surfaces 132 and 134. As a result, the attitude of the screws 104 becomes unstable, so that there is a tendency for the screws 104 to engage with the holes 124 in an inclined attitude.

SUMMARY OF THE INVENTION Accordingly, the object of the present invention is to provide a circuit board connector which has a low profile and which occupies a small area on the circuit board without having any effect on the insertion of mating connectors. The circuit board connector of the present invention comprises an insulating housing which is to be attached to an upper surface of a circuit board, and which has cavities that receive mating connectors inserted from a direction parallel to the upper surface, a plurality of electrical contacts which protrude into the cavities from a rear wall of the housing, and which pass through the rear wall and extend downward toward the circuit board, and screw-attachment sections which form integral parts of the housing, and which have holes that receive screws that attach the housing to the circuit board; the screw- attachment sections are disposed on the circuit board side of the rear wall of the housing, and the thickness of the front walls which form the holes of the screw- attachment sections is greater than the thickness of the rear walls which form the holes. It is desirable that the holes and openings which communicate with the outside be formed in the upper portions of the rear walls of the screw-attachment sections.

It is even more desirable that inclined surfaces, which force the tip portions of the screws toward the rear, be formed in the upper front portions of the holes of the screw-attachment sections.

A circuit board connector for mounting onto a circuit board comprises a dielectric housing having a cavity for receiving a mating section of a matable connector; electrical contacts secured in a rear wall of the dielectric housing including contact sections extending into the cavity and tine sections extending outwardly from the rear wall; and screw-attachment sections extending outwardly from a bottom wall of the dielectric housing and having screw-receiving holes in alignment with the rear wall of the dielectric housing for receiving screws that attach the housing to the circuit board. BRIEF DESCRIPTION OF THE DRAWINGS

An embodiment of the invention will now be described by way of example with reference to the accompanying drawings in which:

Figure 1 is a front view showing a circuit board connector of the present invention. Figure 2 is a bottom view of the connector shown in Figure 1.

Figure 3 is a back view of the connector shown in Figure 1. Figure 4 is a left-side view of the connector shown in Figure 1.

Figure 5 is a cross-sectional view taken along line 5-5 in Figure 1, which shows the connector mounted on a circuit board. Figure 6 is a front view of a conventional connector.

Figure 7 is a cross-sectional view taken along line 7-7 in Figure 6.

DETAILED DESCRIPTION OF THE INVENTION Connector 1 comprises an insulating housing 10 made of a suitable plastic such as PBT, which is formed so that the overall shape of the housing is that of a right- angled parallelepiped; a plurality of rows of male electrical contacts 60, which are secured in a the rear wall 12 of the housing 10; and a tine plate 70. Each of the contacts 60 includes a press-fitting section 62, which is fastened to the rear wall 12 of the housing 10 by press fitting; a tab contact section 64, which protrudes into the interior of a corresponding cavity 14 (14a through 14e) of the housing 10 from the press- fitting section 62; and a tine section 66, which extends outward toward the rear (toward the left in Figure 5) from the rear wall 12 of the housing 10, and which is bent at an intermediate point so that tine section 66 extends toward the circuit board 3. The tine sections 66 are arranged in rows by the tine plate 70.

Tine plate 70 has three rows of through holes 72 corresponding to the contacts 60. Among these rows of through holes 72, some of the through holes 72 in the row closest to the housing 10 are part of longitudinal slots 74. As a result, even in cases where there is a difference in the coefficient of thermal expansion between the circuit board 3 (Figure 5) and the tine plate 70, the stress generated in the soldered portions of the tine sections 66 is relieved so that there is no solder cracking. Furthermore, compensating areas 76 comprising first slots 78 and second slots 80 which extend perpendicular to the direction of the length of the tine plate 70, and third slots 82 which extend in a diagonal direction crossing the slots 78 and 80, are formed at spaced locations along the tine plate 70. Expansion of the tine plate 70 in the direction of length is absorbed by these compensating areas 76, so that solder cracking is prevented.

In the present embodiment, the number of cavities 14 formed in the housing 10 is five; however, any desired number of cavities may be formed. Latching surfaces 18, which latch the latching arms (not shown) of the corresponding mating connectors and thus maintain a state of engagement with the mating connectors are disposed at the approximate centers of the inside surfaces of the upper walls 16 of the respective cavities 14a through 14e. Furthermore, projecting ribs 22 and 24 extend toward the opposite lower walls 20 and upper walls 16 from the respective upper walls 16 and lower walls 20. These projecting ribs 22, 24 act to prevent deformation of the male contacts 60 by the corners (not shown) of the mating connectors or by foreign objects such as tools, and also act to prevent the insertion of similar mating connectors of different types, which is accomplished by altering the positions of the ribs in each of the cavities 14a through 14e, and to prevent the reverse insertion of mating connectors, which is accomplished by insuring that the positions of the upper and lower projecting ribs 22 and 24 do not coincide. Screw-attachment sections 26, which are spaced along the direction of length of the housing 10, are disposed so that these screw-attachment sections 26 protrude from the underside, i. e., the circuit board side, of the rear wall 12 of the housing 10. In the approximate center of each screw-attachment section 26, a screw-receiving hole 28, which has an internal diameter that is smaller than the external diameter of a threaded section 7 of a corresponding screw 5, is delineated by front wall 30, which has an arcuate external shape, and a rear wall 32, which has a polygonal external shape. The rear wall 32 of each screw-attachment section 26 merely protrudes slightly toward the tine sections 66 from the rear wall 12 of the housing 10; accordingly, the area occupied by the connector 1 on the circuit board is not greatly increased. Furthermore, a rear surface 32a of each rear wall 32 is used for positioning of the assembly device (not shown) during the assembly of the connector 1, and is therefore formed as a flat surface which is parallel to the direction of length of the housing 10. The thickness of the front wall 30 is greater than the thickness of the rear wall 32; accordingly, when the screw 5 is screwed into the screw receiving hole 28, the front wall 30 shows almost no movement, while the rear wall 32 expands slightly and moves rearward (toward the left in Figure 5) . As is clear from Figure 5, the front ends 34 of the screw-receiving holes 28 are positioned further to the rear than the bottom surfaces 36 of the cavities 14, and the upper surfaces 38 of these front ends 34 are inclined in a direction which recedes from the engaging recesses 14. Accordingly, thin walls 40 (i. e., the regions confined between the broken lines and the inclined surfaces 38) are present between the screw-receiving holes 28 and the cavities 14, and the tip portions 9 of the screws 5 that are screwed into the screw-receiving holes 28 are forced rearward by the inclined surfaces 38. As a result, the screws 5 do not break through the thin walls 40 and protrude into the cavities 14, and the screws 5 are engaged with the screw-receiving holes 28 without any inclination of the screws 5. Furthermore, since openings 42 that communicate with the outside are formed in the upper portions of the rear walls 32 of the screw-receiving holes 28, the rearward movement of the rear walls 32 of the screw-receiving holes independently of the rear wall 12 of the housing is facilitated. As the rear walls 32 of the screw-receiving holes expand slightly and move rearward when the screws 5 are screwed into the screw-receiving holes 28, the centers of the screws 5 also move slightly rearward (i. e., by approximately 0.1 mm) . As a result, since the screws 5 engage with the screw-receiving holes 28 without breaking through the thin walls 40, there is no effect on the engagement of the mating connectors in the cavities 14; furthermore, even if the length of the threaded sections 7 of the screws 5 is greater than the combined total of the height from the lower surfaces 44 (indicated by a broken line) of the cavities 14 to the lower end 46 of the housing 10, and the thickness of the circuit board 3, the screws 5 can be accommodated inside the screw- receiving holes 28.

A plurality of stand-offs 48 are formed in positions forward of the screw-attachment sections 26 so that stand-offs 48 protrude from the outer surface of the lower wall 20 of the housing 10. These stand-offs 48 are used to stabilize the attitude of the connector 1 mounted on the circuit board, and may also extend to the front end of the housing 10. A groove 50 which is used to allow passage along a rail (not shown) which supplies the housing 10 during the assembly of the connector 1 is formed between several of the stand-offs 48 and screw- attachment sections 26. However, groove 50 need not be formed if such a groove is not needed. In cases where such a groove 50 is not formed, the stand-offs 48 support the front walls 30 of the screw-attachment sections 26 so that the front walls 30 are reinforced.

The circuit board connector of the present invention has been described above. However, the present invention is not limited to the connector described above; it goes without saying that various modifications or alterations may be made if necessary. For example, in the connector described above, the tine sections of the contacts are so-called DIP type tine sections which are passed through through holes in the circuit board; however, it would also be possible to use surface-mount type (SMT) tine sections which are soldered to conductive pads on the surface of the circuit board. Furthermore, as long as there is no interference with the installation of the contacts, it would also be possible to form the screw- attachment sections 26 so that they do not protrude downward from the lower wall 20 of the housing 10.

In the invention, the screw-attachment sections are disposed on the circuit board side, i. e., the underside, of the rear wall of the housing, and the thickness of the front walls which form the holes of the screw-attachment sections is set so that this thickness is greater than the thickness of the rear walls which form the same holes. Accordingly, as a result of a slight expansion of the relatively thin rear walls, the screws are caused to move slightly rearward, so that the screws are accommodated inside the holes of the screw-attachment sections without any protrusion of the screws into the interiors of the cavities. Consequently, a circuit board connector which has a low profile and which occupies only a small area on the circuit board can be obtained without any effect on the ability to insert mating connectors into the cavities.

Furthermore, in the invention, holes and openings which communicate with the outside are formed in the upper portions of the screw-attachment sections; accordingly, there is no hindrance of the expansion of the rear walls which form the holes. Consequently, the screws accommodated in the holes move rearward in a reliable manner, so that the protrusion of these screws into the interiors of the cavities is reliably prevented. Moreover, in the invention, inclined surfaces which force the tip portions of the screws that advance into the holes of the screw-attachment sections toward the rear are formed in the upper front portions of these holes. Accordingly, the tip portions of the screws which move slightly rearward are forced toward the rear so that inclination of the screws is prevented.

Claims

1. A circuit board connector for mounting onto a circuit boarding comprising a dielectric housing having a cavity for receiving a mating section of a matable connector; electrical contacts secured in a rear wall of the dielectric housing including contact sections extending into the cavity and tine sections extending outwardly from the rear wall; and screw-attachment sections extending outwardly from a bottom wall of the dielectric housing and having screw- receiving holes in alignment with the rear wall of the dielectric housing for receiving screws that attach the housing to the circuit board.

2. A circuit board connector as claimed in claim

1, wherein the screw-attachment sections include a front wall and a rear wall through which the screw-receiving holes extend.

3. A circuit board connector as claimed in claim 2, wherein the front wall is thicker than the rear wall.

4. A circuit board connector as claimed in claim

2, wherein the rear wall has an opening at an upper portion of the screw-attachment sections in communication with the screw-receiving holes.

5. A circuit board connector as claimed in claim 4, wherein front upper portions of the screw-receiving holes have inclined surfaces that force tip portions of the screws toward the rear of the dielectric housing.

6. A circuit board connector as claimed in claim 1, wherein stand-offs extend outwardly from the bottom wall forwardly of said screw-attachment sections.

7. A circuit board connector as claimed in claim 1, wherein a tine plate has holes through which ends of the tine sections of the electrical contacts extend.

8. A circuit board connector as claimed in claim 7, wherein said tine plate has compensation areas at spaced locations.

9. A circuit board connector as claimed in claim 8, wherein the compensation areas include offset slots extending inwardly from opposing sides of the tine plate and an elongated slot extending obliquely across the tine plate between the offset slots.

10. A circuit board connector as claimed in claim 9, wherein some of the holes in the tine plate are part of longitudinal slots.

11. A circuit board connector for mounting onto a circuit board comprising a dielectric housing having a cavity for receiving a mating section of a matable connector; electrical contacts secured in a rear wall of said dielectric housing including contact sections extending into the cavity and tine sections extending outwardly from the rear wall; and screw-attachment sections extending outwardly from a bottom wall of said dielectric housing including front walls and rear walls through which screw-receiving holes extend with the front walls being thicker than the rear walls.

12. A circuit board connector as claimed in claim 11, wherein the screw-receiving holes are substantially aligned with said rear wall.

13. A circuit board connector as claimed in claim 11, wherein the rear walls have an opening at an upper portion thereof in communication with the screw-receiving holes .

14. A circuit board connector as claimed in claim 11, wherein front upper portions of said screw-receiving holes have inclined surfaces that force tip portions of screws received in the screw-receiving holes toward the rear of the housing.

15. A circuit board connector as claimed in claim 11, wherein stand-offs extend outwardly from the bottom wall forwardly of said screw-attachment sections.