Alignment member for use with surface mount contacts

Abstract: An electrical connector (10) for surface mounting to a printed circuit board (12) has circuit board mating legs (58,60) of terminals (50) which extend from a housing (11) of the connector. An alignment member (80) cooperates with the mating legs (58,60) of the terminals (50) to maintain the mating legs (58,60) in position relative to each other and relative to the housing (11), thereby facilitating the close center-to-center spacing of the terminals (50).

Description: The present invention is directed to an electrical connector for mounting on a printed circuit board according to the pre-characterizing portion of claim 1. From document EP-A2-0,175,457 a header connector has come to be known. This known header connector includes an integral outrigger parallel to the connector housing and separated therefrom by an open span, a plurality of male-pin terminals each with a long leg fixed in the connector and a short leg disposed at 90° to the long leg and extending between the connector and the outrigger. Evenly spaced slots are provided in a lower surface of the outrigger receiving distal ends of the short legs, whereby the latter are aligned in parallel relation. A pair of projections at opposite ends of the outrigger is received in a corresponding pair of apertures in the printed circuit, whereby the connector is located relative to the printed circuit with each of the short legs disposed over and parallel to a corresponding one of the circuit end segments. Document EP-A2-0,175,457 does not disclose a terminal positioning member being a continuous separate strip of material, which is applicable to and removable from positioning sections. From document US-A-4,952,529 a terminal for coupling to a thick film circuit board has come to be known. This known terminal has a plurality of parallel legs each having an angled foot portion for connection to the thick film circuit board. An elongated tie bar extends perpendicular to the legs and connects the legs to each other for stabilization. The tie bar has sufficient mass and is positioned sufficiently far from the foot so that heat can be applied to the foot to solder it to the thick film substrate. Document US-A-4,952,529 does not disclose an electrical connector having a terminal positioning member which is a continuous separate strip of material including apertures or slots, which is applicable to and removable from the positioning sections. A known electrical connector for surface mounting onto circuit boards is shown in US-A-4,917,614, in which the contacts are to be terminated to pads on a circuit board. The known device provides an electrical connector for mounting on a printed circuit board and comprises a housing with terminal receiving cavities provided therein, the terminal receiving cavities have terminals positioned therein, the terminals have circuit board mating legs which extend from a circuit board mating surface of the connector housing, the circuit board mating legs are configured to cooperate with contact pads provided on the surface of the printed circuit board for surface mounting thereto. The electrical connector of the above construction has the following advantages. The terminals provide electrical continuity between contact members and pads on a printed circuit board. However, the electrical connector of the above construction has the following disadvantages. The mating legs are not closely spaced between centers and therefore take up more space on the printed circuit board. Further, the mating legs are not aligned and retained in position in a way that maintains parallel alignment or eliminates variations in the terminals due to manufacturing tolerances. The present invention overcomes the above-mentioned problems. The object of the present invention is to provide a terminal positioning member which positions the mating legs so that manufacturing variances between the legs is reduced so that a closer center-to-center spacing is provided. The closer spacing of the terminals thereby saves space on the printed circuit board. The present invention provides an electrical connector in accordance with the features set out in claim 1. Preferred embodiments are defined in claims 2 to 8. An electrical connector is provided which mounts on a printed circuit board. The electrical connector has a housing with terminal receiving cavities with terminals positioned therein. The terminals have circuit board mounting portions which extend from the connector housing. The circuit board mounting portions of the terminals are configured to cooperate with contact pads provided on the surface of the printed circuit board. A terminal positioning or alignment member cooperates with the circuit board mounting portions of the terminals to ensure that the circuit board mounting portions are maintained in proper position relative to the connector housing so that as the electrical connector is mated to the printed circuit board, the circuit board mounting portions will be positioned in alignment with the contact pads of the printed circuit board. FIGURE 1 is a three dimensional cross-sectional view of a connector housing having a terminal positioning member provided on terminals thereof. FIGURE 2 is a cross-sectional view of the connector housing of Figure 1 mated to a printed circuit board. FIGURE 3 is a top plan view of a section of the terminal positioning member shown in Figure 1. FIGURE 4 is a top plan view of a section of a first alternate terminal positioning member. FIGURE 5 is a partial cross-sectional view of the connector housing mated to the printed circuit board with a second alternate terminal positioning member provided thereon. FIGURE 6 is a top plan view of a section of the second alternate terminal positioning member. Referring to Figure 1, an electrical connector 10, which provides the electrical connection between a printed circuit board 12 (Figure 2) and a mating connector (not shown), has a housing 11 with a first or connector mating surface 20 and an oppositely facing second or circuit board mating surface 22. End walls 24 and side walls 26 extend between the connector mating surface 20 and the circuit board mating surface 22. A mating connector receiving recess 30 extends from the connector mating surface 20 toward the circuit board mating surface 22. The mating connector receiving recess 30 is dimensioned to be positioned proximate the end walls 24 and proximate the side walls 26. Terminal receiving cavities 32 extend from the circuit board mating surface 22 to the mating connector receiving recess 30. The terminal receiving cavities 32 are provided on both sides of the longitudinal axis of the housing 11 of the connector 10. The terminal receiving cavities 32 provided on a respective side of the axis are mirror images of the terminal receiving cavities provided on the opposite side of the axis. Bus bar receiving recess 48, as best shown in Figure 2, is provided in the connector 10. The bus bar receiving recess 48 extends from the mating connector receiving recess 30 to proximate the circuit board mating surface 22. A bus bar is provided in the recess 48. Terminals 50, as best shown in Figure 2, have mounting portions 52. First legs 54 and second legs 56 extend from the mounting portions 52 into the mating connector receiving recess 30, thereby enabling the first and the second legs 54, 56 to be mated with the mating connector. Printed circuit board mating legs 58, 60 extend from the mounting portions 52 beyond the circuit board mating surface 22. Each circuit board mating leg 58 has an arcuate section 62, an intermediate section 64, a mating section 66 and an alignment or positioning section 68. Each circuit board mating leg 60 has identical sections, with the exception that intermediate section 65 of circuit board mating leg 60 is shorter in length than intermediate portion 64 of circuit board mating leg 58. This configuration allows the mating sections and alignment sections to be staggered, as best shown in Figure 1. The staggered pattern of the mating sections is one characteristic which permits the terminals to have close center-line spacing. The staggered spacing is also required due to the staggered configuration of the pads 70 on the circuit board. This configuration of the pads minimizes the possibility of shorting therebetween. The intermediate sections 64, 65 extend from the housing in a direction which is essentially parallel to the circuit board mating surface 22. As viewed in Figure 2, the intermediate sections 64, 65 have first edge surfaces and second edge surfaces. The mating sections 66 are provided on the first edge surfaces and the alignment sections 68 are provided on the second edge surfaces. As is shown in Figures 2 and 5, the mating sections 66 are positioned in electrical engagement with conductive pads 70 positioned on the surface of printed circuit board 12. The mating sections 66 are soldered to the pads 70 to provide a stable and reliable electrical connection and to provide the mounting required to hold the connector in position relative to the board. In order for a positive electrical connection to be effected, it is essential for the mating sections to be properly aligned with the pads of the board. This is particularly important in application in which the terminals and pads are closely spaced. Referring to Figures 1 and 2, alignment sections 68 extend from printed circuit board mating legs in a direction away from the printed circuit board. The alignment sections 68 are positioned proximate mating sections 66. Each alignment section 68 has a narrow neck section 72 and an enlarged retention section 74. The neck section 72 is integrally attached to the board mating legs of the terminals 50. A terminal positioning or alignment member 80, as shown in Figure 3, is made of mylar, Ryton, water soluble paper, or other material which allows for the resilient deformation of the alignment member when the alignment member is inserted onto the terminals, while providing relatively rigid properties when the material is stretched in the plane of the material. In many instances, the alignment member must be manufactured from a material which is sufficiently transparent to an inferred energy source. This allows the inferred energy to pass through the alignment member and act on the solder, thereby enabling the terminals to be effectively connected to the board. Alignment member 80 has a plurality of openings 82 which extend therethrough. The openings 82 are configured to correspond to the configuration of the alignment sections 68 of the terminals 50. Therefore, in the particular embodiment shown in Figure 3, the openings 82 are staggered in the same manner as alignment sections 68. Each alignment member 80 has a respective opening for each alignment section positioned on a respective side of the connector 10. Each aperture or opening 82 has a circular configuration, the diameter of which is slightly larger than the diameter of the neck section 72. Although the openings shown in Figure 3 are circular, it is conceived that the openings can be of various shapes, including polygon. To position the alignment members on terminals, the alignment members 80 are placed over the alignment sections 68, such that the openings 82 are aligned with the retention sections 64. This may be done prior to or after the terminals have been positioned in the connector. The alignment members are then forced into engagement with the alignment sections. As this occurs, the openings 82, which are smaller in size than the retention sections 74, will be elastically deformed and moved over the retention sections. The material of the alignment member is such that after the openings 82 have been moved past the retention sections 74, the openings will return to a shape which approximates their original shape. After the alignment member has been moved past the retention sections, the openings 82 cooperate with the neck sections 72. In this fully inserted position, the alignment member cooperates with the alignment sections 68 to prevent movement of the alignment sections relative to each other. It is important to note that the openings 82 are only slightly larger than the neck sections 72. Therefore, as the dimensions of the openings and neck sections are essentially the same, the cooperation of the alignment member with the neck portions allows the alignment member and neck portions to behave as a single member. In other words, if a force is applied in a direction indicated by arrow A of Figure 1 to one mating leg 58, the force is transferred through the alignment member to all the mating legs, thereby making it difficult to permanently deform a single mating leg. It is consequently important that the alignment member have sufficient tensile strength to withstand such forces encountered during shipping and handling of the connector. The alignment member 80 is maintained in position on the mating legs by the interference fit described above. Therefore, if a respective terminal must be inspected or repaired, the alignment member may be removed in order to facilitate the operation. As the alignment member 80 may be retained in position on the mating legs, it is important to note that the enlarged retention sections 74 of the alignment sections 68 extend above the alignment member. This configuration allows the enlarged retention sections 74 to be used as test points, thereby eliminating the need to remove the alignment member in order to inspect the terminals 50. In order to provide enhanced stability of the terminals and alignment members relative to the connector 10, the alignment members cooperate with the end walls 24 of the connector. As shown in Figure 1, securing projections 84 of alignment member 80 extend from the main portion of the alignment member in a direction toward connector 10. The securing projections are spaced apart by a distance which is slightly greater than the length of the connector. This allows the securing projections to be positioned adjacent to the end walls of the connector when the alignment member is inserted onto the alignment sections 68. The cooperation of the alignment member with the end walls of the connector provides increased stability to the mating legs of the terminals. As the alignment member is fixed to the connector, a force applied to the mating legs in the direction of arrow A will be transferred to the connector. As the connector housing is relatively rigid, the force applied to the terminal will be absorbed by the housing, thereby preventing damage to the terminal. Consequently, the mating sections of the terminals will be maintained in proper position relative to the connector 10. Figure 4 illustrates an alternate embodiment of the alignment member. Alignment member 86 has openings 88 and slots 90 provided thereon. The openings 88 cooperate with the mating legs 60, as previously discussed. The slots 90 cooperate with the alignment sections 68 of mating legs 58 in a similar manner to the openings. Slots 90 cooperate with neck sections 72. The slots are dimensioned to receive the neck section therein. However, the width of the slots 90 is only slightly larger than the width of the neck portions 72. Consequently, the alignment member will cooperate with mating legs 58 to prevent the movement of the legs in the direction of arrow A of Figure 1. Figures 5 and 6 show a second alternate embodiment of the alignment member. Alignment member 92 has a continuous section 94 with separating arms 96 extending therefrom. As best shown in Figure 5, the continuous section 94 is positioned on mating arms 58, 60 and secured thereto. One manner to secure the continuous section to the mating arms is by means of an adhesive strip, or the like. The separating arms 96 are bent to extend downward (as viewed in Figure 5) between the mating arms 58, 60. The separating arms are dimensioned to extend between the mating arms to maintain the spacing therebetween. With the separating arms positioned between the mating legs of the terminals, it becomes more difficult to deform the individual terminals. Although this embodiment does not have openings and slots as described above, the operation of the alignment member 92 is similar to that described above.

Claims: An electrical connector (10) for mounting on a printed circuit board (12), a) having a housing (11) with terminal receiving cavities (32) provided therein, b) the terminal receiving cavities (32) having terminals (50) positioned therein, c) the terminals (50) having circuit board mating legs (58, 60) which extend from a circuit board mating surface (22) of the connector housing (11), d) the circuit board mating legs (58, 60) are configured to cooperate with contact pads (70) provided on the surface of the printed circuit board (12) for surface mounting thereto, e) a terminal positioning member (80) is provided which cooperates with the legs (58, 60) to ensure that the legs (58, 60) are maintained in proper position relative to the connector housing (11) and at the center-to-center spacing of the legs (58, 60); f) the terminal positioning member includes apertures or slots (82, 90) associated with positioning sections (68) of the mating legs (58, 60); characterized in that: g) the terminal positioning member (80) is a continuous separate strip of material, h) the terminal positioning member (80) is applicable to and removable from the positioning sections. An electrical connector as recited in claim 1, wherein the mating legs (58, 60) include a downwardly extending circuit board mating section (66) and an upwardly extending positioning section (68). An electrical connector as recited in claim 2, wherein said apertures or slots (82, 90) included in said terminal positioning member (80) associated with positioning sections (68) of the mating legs (58, 60) are staggered apertures (82). An electrical connector as recited in claim 1, 2 or 3, wherein the terminal positioning member (80) includes slots (90) for receiving the mating legs (58). An electrical connector as recited in claim 1, 2 or 3, wherein the terminal positioning member (80) includes separating arms (96) for positioning the mating legs (58, 60). An electrical connector as recited in claim 1, wherein the terminal positioning member (80) is of an elastically deformable material, thus being deformable during application to the positioning sections (68) and returning thereafter to a desired shape precisely positioning the positioning sections. An electrical connector as recited in claim 2, wherein the positioning sections (68) extend upwardly beyond the alignment member (80) to define easily accessible test points following mounting to the circuit board (12). An electrical connector as recited in claim 1, wherein the alignment member (80) includes securing sections (84) at ends thereof cooperable with end walls (24) of housing (11) for relieving stress to the legs (58, 60).

Inventors: GRABBE DIMITRY G, KORSUNSKY IOSIF, GRABBE, DIMITRY G., KORSUNSKY, IOSIF
Applicants: WHITAKER CORP, THE WHITAKER CORPORATION
Application year: 1993
Main classification: H01R23
IPC codes: H01R43, H01R12