KR0130920Y1 - Electrical connector for printed circuits boards - Google Patents

Abstract

The electrical connector 14 of the present invention includes an elongated connector housing 16 having an elongated slot 18 disposed along the longitudinal axis 20 of the housing to receive the printed circuit board in the edge direction. A plurality of terminals 28 are inserted in a predetermined insertion direction C into the plurality of passageways along at least one side of the slot. Each terminal includes a retaining portion 36 that fits into the retaining cutout 30 of each passage. The holding incision tapers in the insertion direction from a wider terminal receptacle that facilitates insertion of each terminal into the passageway, to a narrower holding area surrounding each terminal at least in the direction transverse to the longitudinal axis 20 of the housing.

Description

Electrical Connectors for Printed Circuit Boards

1 is a perspective view of an electrical connector of the type for practicing the present invention.

FIG. 2 is a partial perspective view of the right end of the connector of FIG. 1 with the pair of terminals removed to facilitate illustration.

3 is a view similar to FIG. 2 where the terminal is to be inserted into its respective passageway.

4 is a view similar to FIGS. 2 and 3 with the terminals fully inserted into their respective passages.

5 is a partially enlarged view of a pair of terminals partially inserted into their respective passages.

FIG. 6 is a view similar to FIG. 5 with the terminal fully inserted into the passage.

7 is a partial cross-sectional view through the housing showing the shape of the holding cutout of the terminal housing passage.

8-11 are sequential diagrams in which a pair of terminals of similar slope are inserted into respective passageways on both sides of the card slot of the connector.

12 is a schematic partial cross-sectional view taken along the horizontal line passing through the terminal holding incision of the terminal and the housing near the upper portion of the terminal holding incision;

FIG. 13 is a schematic partial cross sectional view taken along the horizontal line passing through the terminal holding incision of the terminal and the housing near the bottom of the terminal holding incision; FIG.

14 is a partially enlarged perspective view of the terminal holding incision.

* Explanation of symbols for main parts of the drawings

14 electrical connector 16 housing

18: slot 20: longitudinal axis

22: passage 28: terminal

30: holding incision 30d: terminal storage port

30e: holding area 36: holding part

The present invention relates to an electrical connector technology, in particular an edgecard connector with spring arm contacts that engage with circuit wiring on a printed circuit board.

One type of electrical connector is commonly referred to as an edge card connector because the connector includes an elongated housing having an elongated slot for receiving the printed circuit board in the edge direction. The connector mounts a plurality of terminals along one or both sides of the slot to electrically contact the printed circuit board with the circuit wiring near the edge. Very common connectors of this type are called SIMM sockets.

Terminals commonly used in edge card connectors are pressure-fitting terminals with stamped molded spring arm contacts that mechanically and electrically engage with circuit wiring on a printed circuit board. The constantly emerging problem in designing such edge card connectors falls into the dilemma of providing high normal forces associated with undesirably high insertion forces of the terminals into the connector housing. In order to provide a satisfactory coupling between the substrate and the spring arm contacts, sufficient normal force must be generated to ensure the desired electrical contact. A typical edge card connector includes parallel opposing terminal rows with spring arm contacts that extend toward each other and define a convex contact engagement surface that can engage a circuit board. The spring arms act as unilateral support levers so that when the substrate is slidably inserted between the arms, the ends of the spring arm contacts are laterally spaced apart. Typically, the higher the normal force, the larger the insertion force.

One solution to this problem of balancing high normal contact forces with undesirable high insertion forces has been to preload the terminals. In other words, when the terminal is pressure-fitted into each passage of the connector housing, the one-sided support spring arm is preloaded against its elastic force, which is then held behind or preloaded by the retaining shoulder of the connector housing.

Preloaded terminals as described above are effective for solving certain problems, but these terminals cause even more serious problems, especially when relatively long connector housings are exposed to relatively high processing temperatures. Specifically, edge card connectors often interconnect the first printed circuit board, which is housed in the edge direction in the connector as described above, with the second printed circuit board by a soldering process that requires the application of heat.

When the long connector housing is exposed to high heat, the plastic material of the housing softens, and a large number of preloaded terminals apply pressure that tends to collapse the softened housing along the substrate receiving slot. The housing can be made of a material that does not collapse under the application of preloaded terminals, but such materials are often expensive.

The present invention is directed to solving many of the problems identified above by adjusting the insertion position of the terminals, thereby avoiding the use of terminals with preloaded spring contacts.

It is therefore an object of the present invention to provide a novel and improved electrical connector of the described features, in particular an improved edge card connector having a terminal provided with a spring contact for engaging a printed circuit board.

In an exemplary embodiment of the present invention, the electrical connector includes an elongated dielectric housing having elongated slots disposed along the longitudinal axis of the housing, in order to receive the printed circuit board in the edge direction. The substrate has circuit wiring in the vicinity of the insertion edge of the substrate.

A plurality of terminal receiving passages are provided along at least one side of the slot. A plurality of terminals are received in the passageway, each terminal comprising a spring contact projecting into the slot to engage the circuit wiring on the printed circuit board. Each terminal further includes a terminal portion protruding from the housing and a holding portion that is pressure-fitted into the holding cutout of each passage. Each terminal is inserted into the passage in a predetermined insertion direction.

The invention contemplates the insertion direction of a narrower retention zone branch that encloses each terminal at least in the direction transverse to the longitudinal axis of the housing from a wider terminal receptacle that facilitates insertion of each terminal into the passage. It is tapered. The retaining incision has an inner sidewall means positioned closest to the slot and positioned to define a reference plane to which the retaining portion of the terminal can engage. The reference plane provides a minimum normal contact force between the spring contact of the terminal and the circuit wiring on the printed circuit board.

Preferably, the terminals are stamped molded of sheet metal. The spring contacts of the terminals form one-sided support spring contacts, and the terminal portions of the terminals form solder tails protruding from the housing.

Another feature of the present invention is that the retaining portion of each terminal is wider than the immediately adjacent portions of the terminals, and the retaining incision of each passage includes sidewalls that press-fit and engage both edges of the retaining portion in a direction generally parallel to the longitudinal axis of the housing. It is. Thus, each terminal is gripped on virtually all four sides when inserted into its respective passageway.

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

Features of the present invention, which are considered novel, are described in detail in the appended utility model claims. The present invention together with the objects and advantages of the present invention will be best understood by reference to the following description taken in connection with the accompanying drawings. Like reference numerals in the drawings denote like elements.

Referring to the drawings in more detail and first with reference to FIG. 1, the present invention is implemented in an edge card electrical connector 14 comprising a dielectric housing 16 integrally molded from plastics. As can be seen in the figure, the housing is quite long (not shown) and defines a long slot 18 disposed along the longitudinal axis 20 of the housing to receive the printed circuit board in the edge direction. The printed circuit board has a plurality of circuit pads or contacts spaced in the longitudinal direction near the insertion edge of the substrate as is known in the art.

The connector 14 is shown as a dual readout connector where the printed circuit board has circuit pads that are electrically separate on both sides adjacent to the insertion edge of the substrate. Correspondingly, the elongated housing 16 has a plurality of terminal receiving passages 22 spaced in the longitudinal direction of the housing on both sides of the longitudinal slot 18. As the printed circuit board is inserted into the slot in the direction of arrow A, the spring contacts of each terminal in the passage 22 establish mechanical and electrical contact with one of the pads located at the edge of the circuit board. The connector has a release lever 24 pivotally mounted at point 26 at each end of the housing to facilitate removal or ejection from the slot 18 of the inserted printed circuit board. Ejection levers are generally known in the art, and the inserted portion of the printed circuit board or shoulder portion of the substrate to release the printed circuit board in the direction opposite to the arrow A direction when the ejector lever is pivoted in the direction of arrow B. It is effective to engage with).

2 through 4 show a pair of terminals 28 for insertion into each terminal receiving passage 22 in the direction of arrow C. FIGS. The terminals are stamped molded of sheet metal and each pair of terminals is identical in shape but mirrors each other when inserted into a pair of passages 22 on the opposite side of the diameter of the slot 18 in the connector housing 16. They are oriented in opposite directions to establish a relationship. Each terminal receiving passage 22 includes a retention cutout or slot 30 for the purposes described below.

Each terminal 28 includes spring contacts 32 projecting into the slots 18 to engage respective circuit pads on the inserted printed circuit board when inserted into the respective passages 22. Each terminal includes a tail 34 that protrudes from the housing 16 when the terminal is fully inserted as shown in FIG. In the disclosed embodiment, the tails 34 form solder tails for insertion into the holes of the second printed circuit board for soldering into circuit wiring and / or holes on the second printed circuit board. Finally, each terminal 28 includes a spring contact 32 and a retainer 36 that is wider than the tail 34. The retaining portion of the terminal is press fit into the retaining cutout 30 of the terminal accommodating passage 22.

2-4 are sequential views of the insertion of terminals 28 into passage 22.

In FIG. 2, the terminal is completely removed from the housing and each passageway. In FIG. 3, the tip of the spring contact of the terminal is beginning to enter into the passage 22. In FIG. 4, the terminal is fully inserted into the passage 22 by the pressure fitting of the retaining portion 36 of the terminal into the retaining cutout 30 of the passage. When fully inserted, the spring contact 32 of the terminal protrudes into the slot 18 to engage with each circuit pad located at the edge of the printed circuit board as shown in FIG.

5 and 6 are enlarged views somewhat similar to those shown by FIGS. 2 through 4 to better illustrate the shapes of the terminal 28, the terminal receiving passage 22 and the retaining cutout 30. . When the terminal is stamped into sheet metal, it can be seen that the spring contact 32 is bent or shaped to define the convex contact engagement surface 32a. These engaging surfaces are exposed in slots 18 in contact with the circuit wiring on the embedded printed circuit board.

It can also be seen that the holder 36 of the terminal is stamped to be wider than the spring contact 32 and the terminal 34. The holding portion has a stepped edge 36a. The holding cutout 30 of the passage 22 also has a longitudinal end wall 30a shaped into a stepped shape corresponding to the shape of the edge 36a of the terminal holding part 36. The longitudinal width of the passageway 22 of the end wall 30a is slightly smaller than the width of the retaining portion 36 so that a pressure fit between the end wall 30a of the retaining cutout and the edge 36a of the terminal retaining portion 36 is achieved. It is supposed to establish While retaining the retaining portion 36 in the housing, the spring contact 32 moves freely in the transverse direction of the slot 18 in the passage 22 to normalize the force between the spring contact and the circuit wiring on the inserted printed circuit board. To provide.

7 and 14 show retaining cuts 30 on both sides of each terminal receiving passage 22 for receiving and pressure-fitting a retaining portion 36 of one of the terminals 28. One is an enlarged perspective view. FIG. 7 also shows one of the plurality of mounting pegs 40 and one of the plurality of spacers 42 integrally molded with and protruding from the bottom surface 44 of the housing 16. As is known in the art, the mounting pegs 40 are inserted into suitable mounting holes in the terminal printed circuit board, and the spacer 42 is provided to space the housing from the substrate for solder reflow process. Finally, FIGS. 7 and 14 illustrate the formation of an introduction or guide surface 45 in the housing leading to the receiving opening 30d of the holding incision 30 to guide the terminal into the holding incision 30. .

More specifically, referring to the retaining cutout 30 of FIG. 7, the retaining cutout 30 is the lateral inner sidewall 30b closest to the substrate receiving slot 18 and the lateral outer sidewall 30c furthest from the slot. It is provided. The side walls 30b and 30c are sloped between the wide terminal receiving opening 30d and the narrow holding area 30e. The side wall 30b is almost vertical and the side wall 30c is inclined about 2 degrees from the vertical. The storage port 30d is wider in the transverse direction than the thickness of the sheet metal of the terminal 28, in particular in the holding portion 36 of the terminal 28. This allows for easy insertion of the retaining portion 36 into the retaining incision 30 (ie, easy insertion of the terminal into the passage 22). On the other hand, the holding zone 30e is dimensioned slightly smaller than the thickness of the terminal to establish a pressure fit with the upper zone of the holding portion 36 of the terminal in the direction of arrow D. Thus, the receiving opening 30d facilitates the insertion of the holding portion 36 of the terminal, and the holding area 30e is held to hold the terminal in the transverse direction of the axis 20, FIG. Only the upper region of the part 36 is gripped. When the side walls 30b and 30c hold the holding portion in the transverse direction of the shaft 20 in the holding region 30e, the end wall 30a of the holding cutout 30 is also generally parallel to the shaft 20, That is, slightly gradient to grip the edge 36a of the retaining portion 36 in the longitudinal direction of the long connector. As a result, the terminals are gripped at all four sides transverse to and parallel to the longitudinal axis of the connector at its holder.

12 and 13 best illustrate how the terminals are gripped. 12 is a cross section taken generally adjacent to the holding zone 30e. Since the distance between the side walls 30b and 30c is smaller than the material thickness T of the holding portion 36 of the terminal, the holding portion is gripped between the side walls 30b and 30c at the point a by a pressure fit. The width between the edges 36a of the retaining portion 36 is greater than the distance between the end walls 30a adjacent the top of the retaining incision and slightly smaller near the inlet zone of the retaining incision. Thus, the end wall 30a also grips the holding portion in the holding region 30e as at point b. However, referring to FIG. 13, it can be seen that the distance between the side walls 30b and 30c is greater than the thickness T of the holder 36. Since the distance between the end walls 30a is smaller than the width between the edges 36a, the retaining portion is gripped only on that edge near the bottom of the retaining cut 30 as at point a. This structure allows the terminals to be correctly aligned as the terminals are inserted into the terminal receiving passages and the terminals are firmly fixed in the terminal receiving passages.

Finally, FIGS. 8-11 illustrate that the terminal 28 may be engaged to provide a minimum normal contact force between the spring contact 32 of the terminal and each circuit wiring on the printed circuit board inserted into the slot 18. The concept of the present invention in establishing a reference plane is shown. These figures should be considered in connection with FIG. More specifically, the terminal 28 can be inserted into the passage 22 in various orientations. In other words, referring to FIGS. 8 to 11, the right terminal in each drawing is shown with the bottom of the terminal (i.e., the tail 34) inclined to the left indicated by arrow E. FIG. The spring contact 32 of the right terminal is inclined outwardly away from the slot 18 as indicated by arrow F (Fig. 8).

8, the left terminal 28 is shown with its bottom or tail portion 34 inclined outward in the arrow G direction. Thus, the upper or spring contact 32 of the left terminal is inclined toward the slot 18 in the direction of the arrow H. Of course, the terminals can be in different oblique orientations as they are inserted into their respective passages in the direction of arrow C. Examples of terminals of FIGS. 8-11 are representative of the various angles that may be encountered in a conventional conventional gang insertion process of inserting terminals.

Regardless of the inclination orientation of the terminals 28 shown as the left and right terminals of FIGS. 8 to 11, the terminals have the inner sidewalls 30b (FIG. 7) closest to the slots 18 retaining portions 36 of the respective terminals. ) Is terminated at the fully inserted position to be the internal limit position or reference plane that can be engaged. Thus, the reference surface defined by the side wall 30b establishes the external final position of the spring contact 32 and its convex contact engagement surface 32a. By accurately positioning the inner surface 30b of the retaining cutout 30 a minimum normal contact force is established between the spring contact of the terminal and each circuit wiring on the printed circuit board.

In other words, referring to FIG. 11, assuming that the retaining portion 36 of the terminal 28 is left in contact engagement with respect to the inner sidewall 30b of the retaining incision, this is indicated by the dashed line 50. Similarly, a predetermined distance is established between the convex contact engaging surfaces 32a of the spring arm portions 32 of the opposing terminals. The embedded printed circuit board is always thicker than this distance, but the distance established by the position of the reference plane electrostatically by the side wall 30b is equal to the minimum required normal contact force designed for the particular electrical connector. Of course, as the holding portion 36 of the terminal moves away from the reference plane 30b and moves toward the sidewall 30c, the distance between the convex contact engagement surfaces 30a (ie, between the dashed line 50) is slightly smaller. Slightly larger normals, but of course the forces are within the minimum set night.

Claims (4)

An elongated dielectric housing having an elongated slot disposed along the longitudinal axis of the housing for receiving an edge of the printed circuit board with contact pads near the edge and for receiving an edge of the printed circuit board, and along at least one side of the slot; A plurality of webs extending perpendicularly to the axis to define a terminal receiving passage, and a plurality of terminals, the terminal receiving passages having a pair of terminal holding cutouts through which the pressure fit of the terminal is inserted along the web; Each of the terminal holding incisions has an end wall perpendicular to the longitudinal axis and a pair of opposing sidewalls parallel to the longitudinal axis, the opposing sidewalls are generally flat, and each terminal is fixed within the terminal receiving passage; Pressure fitting into the terminal retention incision of each passage in the predetermined insertion direction with the tail protruding from the housing and And a one-sided supported spring contact extending between the pressure fit and the free end of the terminal, the free end being spaced from the housing and the spring contact being on the printed circuit board. 12. An electrical connector projecting into a slot to engage a contact pad and spaced apart from the housing along the entire length between the pressure fit and the free end, wherein each terminal retaining cutout of the terminal receiving passage is each into a passage. A gradient in the insertion direction between the opposing sidewall stones from a wide terminal receptacle to facilitate insertion of the terminals of the terminal to at least a narrow retaining area surrounding each terminal in a direction transverse to the longitudinal axis, one of the opposing sidewalls being Located closest to the slot, spring contact of the terminal Defining a reference surface to which the pressure fitting portion of the terminal can be engaged to provide a minimum normal contact force between the portion and each contact pad on the printed circuit board, wherein a predetermined thickness of the pressure fitting portion of the terminal is less than the narrow holding area. Wider in the direction perpendicular to and narrower in the direction perpendicular to the axis than the distance between the end bricks of the terminal receiving passageway, so that the pressure fitting portion of the terminal is press-fit only between at least one portion of the opposing side wall. And pressure fit between the entire length of the end wall. The electrical connector as claimed in claim 1, wherein the terminal comprises a stamped sheet metal material. 3. The retaining portion of each terminal is wider than immediately adjacent portions of the terminal, and each retaining incision includes an edge wall that press fits the end wall of the retaining portion in a direction parallel to the axis. Electrical connector, characterized in that. 3. The electrical connector as claimed in claim 2, wherein the spring contact of the terminal comprises a molded spring contact arm and the terminal part of the terminal comprises a solder tail protruding from the housing.