WO2004095648A1

WO2004095648A1 - Memory card connector with improved terminal retention

Info

Publication number: WO2004095648A1
Application number: PCT/US2004/008886
Authority: WO
Inventors: Sun Zhao You
Original assignee: Molex LLC
Current assignee: Molex LLC
Priority date: 2003-04-01
Filing date: 2004-03-24
Publication date: 2004-11-04
Anticipated expiration: 2005-10-01
Also published as: CN2658961Y

Abstract

A memory card connector includes an insulative housing having a top mating face, a bottom circuit board mounting face and at least one through passage extending between the faces. The passage has an opening in the mating face of the housing. A terminal is inserted into the through passage of the housing from the bottom face thereof. The terminal includes a base portion, a spring arm extending from the base portion and having a contact end projecting through the opening in the mating face of the housing for engaging an appropriate contact of a memory card. A tail portion extends from the base portion exteriorly of the housing for connection to an appropriate circuit trace on the printed circuit board. A locking boss protrudes from a side wall of the passage over the base portion of the terminal to prevent the terminal from pulling out of the passage.

Description

MEMORY CARD CONNECTOR WITH IMPROVED TERMINAL RETENTION

Field of the Invention:

This invention generally relates to the art of electrical connectors and, particularly, to a memory card connector having an improved terminal retention system.

Background of the Invention:

Memory cards are known in the art and contain intelligence in the form of a memory circuit or other electronic program. Some form of card reader reads the information or memory stored on the card. Such cards are used in many applications including mobile telephones which are actuated and permit data access after identifying an identification code stored on a SIM (subscriber identification module) card. The SIM card has a conductive face with an array of contacts, and the mobile phone has a SIM card connector with terminals for electrical connection with the contacts of the SIM card to ensure the subscriber identification confirmation and provide wireless communication service.

Examples of prior memory card connectors are shown in Chinese patent application No. 99125707 and Taiwanese Patent Application Nos. 85205015 and 86212738.

FIGS. 1 and 2 show a prior art connector, generally designated 16, which includes a dielectric housing or body, generally designated 18, for mounting a plurality of conductive terminals, generally designated 20. The terminals are mounted in a plurality of terminal- receiving passages, generally designated 22, extending through the housing. Each terminal is generally U-shaped as defined by a base portion 24 and a resilient contact arm 26 joined by a curved bight or connecting portion 28. A tail portion 30 projects from base portion 24 for connection, as by soldering, to an appropriate circuit trace on a printed circuit board. When a contact of a SIM card engages resilient contact arm 26, the contact arm flexes into the respective passage 22 for the terminal to establish a positive contacting engagement therebetween.

Each terminal 20 is retained in its respective passage 22 by a pair of wing portions 32 which project outwardly from opposite edges of body portion 24. The wing portions establish a frictional interference fit with opposite side walls of the terminal-receiving passage, as at 34 (Figs. 1 and 2). This retention system causes various problems. For instance, if a rotary torque force is applied to one of the terminals 20, wing portions 32 may separate from the side walls of the respective passage and the terminal will become loosened. In addition, when heat is applied to solder connect tail portions 30 to the printed circuit board, the different coefficients of expansion between the housing (plastic) and the terminal (metal) also may cause the terminal to become loosened. In other words, wing portions 32 of the terminal may separate from the side walls of the respective passage, as at 34. Loose terminals can create cracks in the solder connections between tail portions 30 of the terminals and the printed circuit board. The present invention is directed to solving these various problems.

Summary of the Invention:

An object, therefore, of the invention is to provide a memory card connector of the character described, with a new and improved terminal retention system.

In the exemplary embodiment of the invention, the connector includes an insulative housing having a top mating face, a bottom circuit board mounting face and at least one through passage extending between the faces. The passage has an opening in the mating face of the housing. A terminal is inserted into the through passage of the housing from the bottom face thereof. The terminal includes a base portion, a spring arm extending from the base portion and having a contact end projecting through the opening in the mating face of the housing for engaging an appropriate contact of a complementary mating connecting device. A tail portion extends from the base portion exteriorly of the housing for connection to an appropriate circuit trace on the printed circuit board. Complementary interengaging lock means are provided between the base portion of the terminal and the housing to prevent the terminal from pulling out of the passage. The lock means include at least one locking portion protruding from a side wall of the passage over the base portion of the terminal.

As disclosed herein, a pair of the locking portions protrude from opposite side walls of the passage over opposite sides of the base portion of the terminal. The locking portions comprise chamfered bosses over which the base portion of the terminal snaps into locking engagement therewith automatically in response to inserting the terminal into the through passage.

Preferably, the terminal includes a pair of wing portions protruding outwardly from opposite sides of the base portion for locking engagement with the bosses protruding from opposite side walls of the housing. The base portion of the terminal herein is generally planar, and the wing portions are coplanar with the base portion. The contact end of the spring arm of the terminal is dome-shaped to form a convex contact surface for engaging the contact of the complementary mating connecting device.

Other objects, features and advantages of the invention will be apparent from the following detailed description taken in connection with the accompanying drawings.

Brief Description of the Drawings:

The features of this invention which are believed to be novel are set forth with particularity in the appended claims. The invention, together with its objects and the advantages thereof, may be best understood by reference to the following description taken in conjunction with the accompanying drawings, in which like reference numerals identify like elements in the figures and in which:

FIG. 1 is a perspective view, partially cut-away, of a prior art memory card connector;

FIG. 2 is an enlarged depiction of the area encircled at "A" in FIG. 1;

FIG. 3 is a top plan view of a first embodiment of a connector according to the invention;

FIG. 4 is an exploded perspective view of the connector of FIG. 3;

FIG. 5 is a bottom perspective view of the connector of FIGS. 3 and 4, with one of the terminals removed;

FIG. 6 is an enlarged depiction of the area of FIG. 5 encircled at "B";

FIG. 7 is a top plan view of one of the terminals of the first embodiment;

FIG. 8 is a top plan view of a connector according to a second embodiment of the invention;

FIG. 9 is a bottom plan view of the second embodiment;

FIG. 10 is a vertical section taken generally along line 10-10 in FIG. 9;

FIG. 11 is a view similar to that of FIG. 4, but of the second embodiment;

FIG. 12 is a view similar to that of FIG. 5, but of the second embodiment;

FIG. 13 is a view similar to that of FIG. 6, but of the second embodiment; and

FIG. 14 is a view similar to that of FIG. 7, but of the second embodiment.

Detailed Description of the Preferred Embodiments:

Referring to the drawings in greater detail, and first to FIGS. 3-6, a first embodiment of a memory card connector is generally designated 36. The connector includes an insulative housing or body, generally designated 38, which includes a top mating face 40, a bottom circuit board mounting face 42 and a plurality of through terminal-receiving passages, generally designated 44, extending between the faces. Each passage 44 has an opening 46 in mating face 40 of the housing. A plurality of conductive terminals, generally designated 48, are mounted in passages 44 by inserting the terminals into the passages from bottom face 42 of housing 38.

Referring to FIGS. 4 and 7, each terminal 48 is generally U-shaped and may be stamped and formed of conductive sheet metal material. Each terminal includes a generally planar base portion 50 and a resilient or flexible spring arm 52. The base portion and spring arm are joined by a semi-circular connecting portion 54 to form the U-shape. A tail portion 56 projects from an end of base portion 50 and is offset therefrom for connection, as by soldering, to an appropriate circuit trace on a printed circuit board (not shown) against which the bottom circuit board mounting face 42 of housing 38 is engaged. Spring arm 52 includes a dome-shaped contact end 58 which projects through opening 46 of a respective passage 44 in mating face 40 of the housing, for engaging an appropriate contact of a complementary mating connecting device, such as a memory card. Base portion 50 includes a pair of locating wings 60 and a pair of locking wings 62 project outwardly from opposite edges of the base portion, coplanar therewith, for purposes to be described hereinafter. A pair of locking tabs 64 project perpendicularly from opposite edges of base portion 50 toward spring arm 52. The lock tabs have outwardly bulging detents 66. Finally, an anti-overstress bar 66 is located transversely at the distal end of spring arm 52 beyond the dome-shaped contact end 58 of the spring arm.

Referring to FIG. 5 and 6, a pair of locking holes 70 are formed in housing 38 at opposite sides of each terminal-receiving passage 44 for receiving lock tabs 64 of a respective terminal 48. Teeth at opposite edges of lock tabs 64 bight into the plastic material of the housing within locking holes 70, and bulging detents 66 of lock tabs 64 further provide an interference locking fit of the tabs within the locking holes.

Still referring to FIGS. 5 and 6, each passage 44 includes opposite side walls 72. A locking projection in the form of a chamfered locking boss 7.4 protrudes inwardly from each opposite side wall 72. Each chamfered locking boss 74 includes an angled surface 74a and an abrupt locking surface 74b. Finally, anti-overstress steps 46 are formed in passages 44 at opposite sides thereof.

When one of the terminals 48 is inserted into a respective passage 44 from bottom board-mounting face 42 of housing 38, lock tabs 64 of the terminals enter locking holes 70 in the housing. Locating wings 60 of the terminal ride along locating surfaces 72a (Fig. 5) of side walls 72 of the passage. As the terminal is inserted, locking wings 62 ride along angled surfaces 74a of chamfered locking bosses 74 until the locking wings reach abrupt locking surfaces 74b of the locking bosses, at which point locking wings 72 automatically "snap" into positive locking engagement with the abrupt locking surfaces. The terminal now cannot back out of its passage regardless of torque forces applied thereto and regardless of differences of coefficients of expansion between the plastic housing and the metal terminal when the terminals are heated during soldering to the printed circuit board. Tail portions 56 will not move and their solder connections will not crack. When the terminal is fully inserted and locked in its respective passage, the anti-overstress bar 68 of the respective terminal engages anti-overstress steps 76 within the respective passage to prevent excessive flexing of spring arm 52 and the dome-shaped contact end 58 outwardly of the housing.

FIGS. 8-14 show a second embodiment of a memory card connector, generally designated 36 A, according to the invention. The housing and terminals of connector 36A are quite similar to the housing and terminals of connector 36 (Figs. 3-7) of the first embodiment and, consequently, like reference numerals have been applied to like components in FIGS. 8- 14 corresponding to the components described above in relation to the first embodiment. Therefore, descriptions of these like components will not be repeated. The principal difference between the second embodiment (connector 36A) and the first embodiment (connector 36) is in the fact that the terminals of the second embodiment do not include the locating wings 60 (Figs. 4, 5 and 7) of the first embodiment. The terminals of the second embodiment include a single set of wings 62 which project outwardly from opposite edges of base portion 50, and wings 62 are locking wings similar to the first embodiment.

Housing 38 of the second embodiment includes a locking portion 74 projecting inwardly from each opposite side wall 72 of each passage 44. Again, locking portion 74 is in the form of a chamfered boss over which one of the locking wings 72 rides and snaps into locking engagement. To that end, each chamfered locking boss 74 has an angled surface 74a and an abrupt locking surface 74b similar to the chamfered boss of the first embodiment. As best shown in FIG. 10, when terminals 48 are inserted into passages 44 in the direction of arrows "C", locking wings 62 of the terminals ride over angled surfaces 74a of chamfered bosses 74 and automatically "snap" into locking engagement behind abrupt locking surfaces 74b of the locking bosses.

It will be understood that the invention may be embodied in other specific forms without departing from the spirit or central characteristics thereof. The present examples and embodiments, therefore, are to be considered in all respects as illustrative and not restrictive, and the invention is not to be limited to the details given herein.

Claims

CLAIMS:What is claimed is:

1. A memory card connector, comprising: an insulative housing having a top mating face, a bottom circuit board mounting face and at least one through passage extending between the faces, the passage having an opening in the mating face of the housing; a terminal inserted into the through passage of the housing from the bottom face thereof and including a base portion, a spring arm extending from the base portion and having a contact end projecting through the opening in the mating face of the housing for engaging an appropriate contact of a memory card, and a tail portion extending from the base portion exteriorly of the housing for connection to an appropriate circuit trace on the printed circuit board; and complementary interengaging lock means between the base portion of the terminal and the housing to prevent the terminal from pulling out of the passage, including at least one locking portion protruding from a side wall of the passage over the base portion of the terminal.

2. The memory card connector of claim 1, including a pair of said locking portions protruding inwardly from opposite side walls of the passage over opposite sides of the base portion of the terminal.

3. The memory card connector of claim 1 wherein said locking portion comprises a chamfered boss over which the base portion of the terminal snaps into locking engagement therewith automatically in response to inserting the terminal into the through passage.

4. The memory card connector of claim 1 wherein said terminal includes a wing portion protruding from the base portion for locking engagement with said locking portion protruding from the side wall of the housing.

5. The memory card connector of claim 4 wherein said base portion of the terminal is generally planar and said wing portion is coplanar therewith.

6. The memory card connector of claim 1 wherein the contact end of the spring arm of said terminal is dome-shaped to form a convex contact surface for engaging the contact of the memory card.

7. A memory card connector, comprising: an insulative housing having a top mating face, a bottom circuit board mounting face and at least one through passage extending between the faces, the passage having an opening in the mating face of the housing; a terminal inserted into the through passage of the housing from the bottom face thereof, the terminal being stamped and formed of conductive sheet metal material and including a generally planar base portion, a spring arm extending from the base portion and having a contact end projecting through the opening in the mating face of the housing for engaging an appropriate contact of a memory card, and a tail portion extending from the base portion exteriorly of the housing for connection to an appropriate circuit trace on the printed circuit board; and complementary interengaging lock means between the base portion of the terminal and the housing to prevent the terminal from pulling out of the passage, including a pair of locking portions protruding inwardly from opposite side walls of the passage, and the terminal includes a pair of wing portions generally coplanar with the base portion at opposite sides thereof for locking engagement with said locking portions protruding from the side walls of the passage in the housing.

8. The memory card connector of claim 7 wherein said locking portions comprise chamfered bosses over which the wing portions of the terminals snap into locking engagement therewith automatically in response to inserting the terminal into the through passage.

9. The memory card connector of claim 7 wherein the contact end of the spring arm of said terminal is dome-shaped to form a convex contact surface for engaging the contact of the memory card.

10. A memory card connector, comprising: an insulative housing having a top mating face, a bottom circuit board mounting face and at least one through passage extending between the faces, the passage having an opening in the mating face of the housing; a terminal inserted into the through passage of the housing from the bottom face thereof and including a base portion, a spring arm extending from the base portion and having a contact end projecting through the opening in the mating face of the housing for engaging an appropriate contact of a memory card, and a tail portion extending from the base portion exteriorly of the housing for connection to an appropriate circuit trace on the printed circuit board; and complementary interengaging snap latch means between the base portion of the terminal and the housing and which lockingly interengages automatically in response to inserting the terminal into the through passage to prevent the terminal from pulling out of the passage.

11. The memory card connector of claim 10 wherein said snap latch means comprises a chamfered boss over which the base portion of the terminal snaps into locking engagement therewith automatically in response to inserting the terminal into the through passage.

12. The memory card connector of claim 11 wherein said snap latch means includes a wing portion protruding from the base portion for locking engagement with said chamfered boss.

13. The memory card connector of claim 12 wherein said base portion of the terminal is generally planar and said wing portion is coplanar therewith.

14. The memory card connector of claim 12, including a pair of said chamfered bosses protruding inwardly from opposite side walls of the passage, and a pair of said wing portions protruding outwardly from the base portion of the terminal.