Improvement in or relating to the terminal element of a surface-applied type electric connector

Abstract: Disclosed is a connector mounted to the surface of a printed circuit board (17) including a housing (1) having terminal receiving recesses (3) and a plurality of terminals (4) stamped from a surface plated metal sheet. The terminals have an intermediate section (7) with a vertical axis (18), a lower section (8) extending from the intermediate section with a transition section (21) located out of the vertical axis (18) and being generally C-shaped and a generally horizontal foot (16) extending from the transition section (21) and aligned with the vertical axis.

Description: Background of the Invention Field of Invention: The present invention relates to a surface-applied type electric connector, and more particularly to the improvement of the soldering tail of such surface-applied type electric connector. Description of Prior Art: Surface-applied type electric connectors have been widely used, and as is well known, such an electric connector has a soldering tail to be soldered to a selected conductor on a printed circuit board. One such conventional surface-applied type electric connector is stamped from a plated metal sheet including a base and an integrally connected solder tail. Since the portion of the solder tail contacting the printed circuit board was an unplated edge cut from a plated metal sheet, this unplated cut edge had to be plated at a later manufacturing step because an unplated surface would not assure firm soldering to a selected conductor strip on a printed circuit board. This extra plating results in an increase of the manufacturing cost. Another conventional surface applied type electrical connector has a solder tail with a foot bent at a right angle from a portion of the terminal so that a plated surface of the terminal will be in contact with a solder pad over a conductor strip on a printed circuit board when the connector is placed on the printed circuit board. With only one right angle bend, there is some but not enough flexibility in the solder tail foot to insure contact with all of the selected conductor strips on the printed circuit board in the event of board warpage. Also, this singe right angle bend offsets the placement location of the connector housing. This offset requires additional housing tolerances and labor in the assembly operation to ensure that accurate connector placement occurs. The closest prior art is shown in DE 36 37 190 A1. This document does not show stamped terminals having a base section and a generally elongated intermediate section which extends from the base section with a vertical axis. Moreover, this document does not disclose, a lower section including a transition section located out of the vertical axis of the intermediate section and a generally horizontal foot aligned with and centred on said vertical axis. Summary of the Invention: One object of the present invention is to provide a stamped terminal structure which permits use of a selected portion of the plated surface of a plated metal sheet for making a solder tail with a flexible solder tail foot, thereby eliminating the extra plating step which is required in making the conventional terminal elements and providing flexibility to insure each foot is in contact with corresponding portions of the printed circuit board. In the event the board is warped. To attain this objet the present invention is provided including the features of claim 1. According to an embodiment of the invention the transition section of said terminal is generally C-shaped. According to still another embodiment of the invention the terminal is stamped from a surface plated metal sheet and formed so that a surface of the horizontal foot in contact with the conductor strip on the printed circuit board will be plated. According to a further embodiment of the invention, each terminal receiving recess has a mounting slot and each terminal has a mounting section adapted to be held in the mounting slot. Brief Description of the Drawings Figure 1 is a plane view of a surface-mounted electric connector which has a plurality of terminal elements fitted therein; Figure 2 is a front view of the surface-mounted electric connector; Figure 3 is a right side view of the surface-mounted electric connector; Figure 4 is a section view taken along the line 4-4 in Figure 2; Figure 5 is an enlarged left side view of the soldering tail and leg section of the terminal; Figure 6 is an enlarged front view of the soldering tail-and-leg section of the terminal; and Figure 7 is an enlarged right side view of the soldering tail and leg section of the terminal; Detailed Description of Preferred Embodiment: Referring to the drawings in greater detail and first to Figure 1, the invention is depicted in an electrical connector construction or assembly, generally designated 1, which includes a unitary dielectric housing, generally designated 2, molded of plastic. This housing has an upper connector mating face 19 and a lower board mounting face 20. The housing has a plurality of elongated terminal receiving recesses 3 extending through the connector mating face into the housing. Each recess 3 has a mounting slot 10 located within the recess and extending toward the board mounting face 20 of the housing. As will be better understood below, after a description of the terminals, the elongated terminal receiving recesses 3 and mounting slots 10 are adapted for receiving a positioning the terminals, generally designated 4, which are inserted into the housing through the connector mating face 19. Extending beyond the board mounting face 20 are board locks 15. These board locks are adapted to penetrate through apertures (not shown) in the printed circuit board 17. The board locks will hold the connector 1 in place thereby holding the terminal solder tails against conductor strips on the printed circuit board 17 prior to soldering. Referring to Figure 4, the terminal 4 is a metal component stamped from a plated sheet of metal. The terminal includes a base section 6, a mating section 5, a mounting section 9, an intermediate section 7 extending from one edge of the base section and a lower section 8 extending from the intermediate section 7. The intermediate section 7 is in the form of an L-shaped arm and is adapted to fit into a portion of the terminal receiving recesses passing through two sides of the housing. A stub arm 22 extends from an edge of the base section 5 opposite the intermediate section 7. The stub 22 and the horizontal portion of the intermediate section 7 act to locate and h old a portion of the terminal in the terminal receiving recesses. The terminals are inserted into the recesses with every other one rotated 180 degrees so that the horizontal foot 16 alternates from side to side. The mounting section 9 is adapted to tightly fit within the mounting slot 10 which is a part of the elongated terminal recesses 3 of the housing. The intermediate section 7 extends toward the printed circuit board and ends in the lower section 8 which contacts a conductor strip on the printed circuit board. Figures 5, 6 and 7 show details of the lower section 8. Extending from the intermediate section 7 is the lower section 8. This lower section consists of generally two parts. One part is the generally horizontal foot 16 which is adapted to contact a conductor strip on a printed circuit board and a transition section 21 extending between the intermediate section and the horizontal foot 16. The transition section 21 is located out of the vertical axis 18 of the intermediate section 7. The horizontal foot 16 is located directly under and generally perpendicular to the vertical axis 18 of the intermediate section. The portion of the horizontal foot 16 contacting the conductor strip on the printed circuit board includes plated surface 14. The other plated surface 13 is parallel to and opposite the plated surface 14. Unplated edges 11 and 12 are also shown. Referring to Figure 2, it is clear to see that laterally locating the upper mating portion 5 of the terminals will also laterally locate the lower generally horizontal foot 16 because the horizontal foot 16 is generally aligned with the vertical axis 18 of the intermediate section 7. This facilitates the precise positioning of the electrical connector relative to selected conductor strips on the underlying printed circuit board 17. Also referring to Figures 2 and 4, the horizontal foot 16 can be designed to extend slightly below the board mating face 20 of the connector housing 2. Because of the flexibility inherent in the C-shaped transition 21 section which connects the horizontal foot 16 to the intermediate section 7, the horizontal foot 16 can flex to accommodate warpage in the printed circuit board as that the horizontal feet 16 of all of the terminals will make contact with associated conductor strips on the printed circuit board 17. While the present preferred embodiment of the invention has been shown and described, it is to be distinctly understood that the invention is not limited thereto but may be otherwise variously embodied within the scope of the following claims.

Claims: Connector for mounting to a surface of a printed circuit board (17) including: a housing (1) having a board mounting face (20), a connector mounting face (19), and a plurality of elongated terminal receiving recesses (3) parallel to each other and extending within the housing, a plurality of stamped terminals (4) mounted in the recesses (3), each terminal having a base section (6), a generally elongated intermediate section (7) extending from the base section (6) with a vertical axis (18), a lower section (8) extending from the intermediate section (7) and a generally horizontal foot (16) extending from the lower section with a solder region adapted to be secured to a conductor strip on the surface of the printed circuit board, the lower section (8) including a transition section (21) located out of the vertical axis (18) of the intermediate section (7) and the generally horizontal foot (16) aligned with and centered on said vertical axis (18). Connector according to claim 1, wherein said transition section (21) of said terminal is generally C-shaped. Connector according to claim 2 wherein said terminal is stamped from a surface plated metal sheet and formed so that a surface (14) of the horizontal foot (16) in contact with the conductor strip on the printed circuit board will be plated. Connector according to claim 3 wherein said terminal (40) is a blade type. Connector according to claim 3 wherein said elongated terminal receiving recesses (3) pass through said housing connector mounting face (19). Connector according to claim 4, wherein said terminal receiving recesses (3) have a mounting slot (10) and said terminals have a mounting section (9) adapted to be held in said mounting slot (10).

Inventors: KUNISHI SHINSUKE, OHYA MASAAKI, KUNISHI, SHINSUKE, OHYA, MASAAKI
Applicants: MOLEX INC, MOLEX INCORPORATED
Application year: 1993
Main classification: H01R23
IPC codes: H05K3, H01R12