Abstract:
A surface mount connector that can be used for both single and double-sided PWB&#39;s. A telephone may have a printed wiring board with connector access from the bottom of the telephone and keypad activation from the top of the telephone. If a double-sided PWB is used, the connector is mounted to the bottom side of the PWB, while the keypad is mounted to the top of the PWB. The connector faces away from the PWB to provide access from below the telephone. If a single-sided PWB is used, the connector is mounted to the top side of the PWB, so that the keypad can also be mounted to the top side. The connector is placed, with connector access down, into an opening through the PWB. The connector extends down through the opening in the PWB with the leads of the connector remaining on the top side of the PWB. The leads of the connector are secured to pads on the top side of the PWB.

Description:
This is a divisional of application Ser. No. 08/690,781 filed on Jul. 23, 1996. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to the field of connection mechanisms for connecting to a printed wiring board (PWB). 
     BACKGROUND OF THE INVENTION 
     PWB&#39;s are used in a wide variety of electronic devices. Various types of connectors can be mounted on PWB&#39;s to transfer electronic signals to and from the PWB. Depending on the particular circumstances involved, surface mount connectors can provide well known advantages over other types of connectors, such as lower cost, manufacturing efficiencies and increased component density. The surface mount connector mechanism of the present invention can be used in any application utilizing a PWB. The present invention can also be used to implement various different types of surface mount connectors, having a variety of sizes, shapes, pin configurations and other characteristics. The preferred embodiment of the present invention is described in terms of a telephone application, including descriptions of several different types of surface mount connectors and a surface mount PWB interconnection mechanism. 
     SUMMARY OF THE INVENTION 
     A surface mount connector of the present invention can be mounted on either a first side or a second side of a PWB. The connector provides access at the first side of the PWB whether it is mounted on the first side or the second side. If the connector is to be mounted on the first side, the PWB has one or more pads on the first side. If the connector is to be mounted on the second side, the PWB has one or more pads on the second side and the PWB defines an opening through the PWB. The connector comprises a connector body having a length, a width and a height one or more signal leads. The length and width of the connector body have smaller dimensions than the opening in the PWB. The signal leads extend beyond the dimensions of the opening in the PWB. If the connector is mounted on the first side, the connector is placed on the first side so that the leads contact the pads. If the connector is mounted on the second side, the connector is placed partially through the opening from the second side so that the leads contact the pads. 
     The present invention also encompasses a method of mounting a connector on a PWB. The method of mounting the connector provides access to the connector from a first side of the PWB. The PWB also has an opposite side and at least one signal pad. The connector also has at least one signal lead. The method comprises the following steps. If the connector is to be mounted on the first side, the connector is placed on the first side with the signal leads of the connector making contact with the signal pads of the PWB, the signal pads of the PWB being on the first side. If the connector is to be mounted on the opposite side, the connector is placed through an opening in the PWB from the opposite side through to the first side with the signal leads of the connector making contact with the signal pads of the PWB, the signal pads of the PWB being on the opposite side. Lastly, the signal leads of the connector are secured to the signal pads of the PWB. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of a telephone using several surface mount connectors of the present invention. 
     FIG. 2 is an exploded view of the telephone of FIG.  1 . 
     FIG. 3 is a top perspective view of a first embodiment of the surface mount connector of the present invention mounted in a single-sided PWB. 
     FIG. 4 is a bottom perspective view of the first embodiment of the connector of the present invention mounted on a single-sided PWB. 
     FIG. 5 is a side view of the first embodiment of the connector of the present invention mounted on a single-sided PWB. 
     FIG. 6 is a bottom perspective view of the first embodiment of the connector of the present invention mounted on a double-sided PWB. 
     FIG. 7 is a side view of the first embodiment of the connector of the present invention mounted on a double-sided PWB. 
     FIG. 8 is a perspective view of an option module that can be inserted into an option module bay of the telephone of FIGS. 1 and 2. 
     FIG. 9 is a side view of an interconnection mechanism interfacing an option module PWB with a single-sided telephone PWB. 
     FIG. 10 is a side view of the interconnection mechanism of FIG. 9, interfacing an option module PWB with a double-sided telephone PWB. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The surface mount connector of the present invention is used in a family of telephones with a common industrial design and various other common design features. Each of the telephone models in the family has a different combination of features. For example, each model may have a two line or an eight line liquid crystal display (LCD) (or no display), a QWERTY style keyboard, an extended set of function keys, a speaker phone function and/or one or more option module bays. 
     FIG. 1 is a perspective view of one of the telephones in the family. The telephone  90  of FIG. 1 has a two line LCD display  100 , an extended set of function keys, a speaker phone function and two option module bays. FIG. 2 is an exploded view of the telephone  90  of FIG. 1, showing the LCD display  100 , an upper housing component  200 , a lower housing component  300  and a single-sided PWB  400 A. 
     FIG. 2 also illustrates a plurality of connectors  500  of the present invention mounted into an upper surface  404 A of the PWB  400 A and extending through to a lower surface  406 A (not shown in FIG.  2 ). Specifically, FIG. 2 illustrates a standard Mod 4-pin connector  500 A, a Mod 6-pin connector  500 B, a Mod 8-pin connector  500 C and a pair of card edge connectors  500 D. Each of the connectors  500  is a female-type connector, with access from below. Thus, for example, a Mod 4-pin plug connector can be inserted into the connector  500 A from beneath the PWB  400 A. 
     FIG. 2 also illustrates a plurality of connector support structures  502  defined within the lower housing component  300 . Specifically, FIG. 2 illustates a standard Mod 4-pin connector support structure  502 A, a Mod 6-pin connector support structure  502 B, a Mod 8-pin connector support structure  502 C and a pair of card edge connector support structures  502 D. Each of the connector support structures  502  defines an opening that allows access to the corresponding connector  500  from beneath the lower housing components  300 . Thus, for example, when the telephone  90  is assembled, a Mod 4-pin plug connector can be inserted into the connector  500 A through the bottom of the telephone  90  (ie. through the connector support structure  502 A). 
     The bottom surface of the upper housing component  200  also has connector support structures (not shown). For each of the connectors  500 , a support structure extends down from the bottom surface of the upper housing component  200  towards the corresponding connector  500 . When the telephone  90  is assembled, each of the support structures may make contact with the corresponding connector  500  at the surface that is visible in FIG. 2, or the support structures are at least close enough to provide support to the connectors  500 . Thus, when a male connector is inserted into a connector  500  from below, the corresponding support structure of the upper housing component  200  supports the connector  500  to enable enough pressure to be applied to the male connector for insertion. The surface of the support structure that provides support to the connector  500  is preferably substantially parallel with the upper surface  404 A of the PWB  400 A. 
     Each of the telephone models in the family has an upper housing component, a lower housing component and a PWB, although the size and design of each of these components varies from model to model. The most basic telephone model (not illustrated) has no display, no QWERTY style keyboard, no extended set of function keys, no speaker phone function and no option module bays. The most basic telephone model uses a single-sided PWB, having only one signal routing layer. As features are added to the most basic telephone model to obtain other telephone models, additional circuitry and, consequently, additional signal routing is required. When possible, a single-sided PWB is used to reduce cost. However, depending on the features implemented in each telephone model, a double-sided PWB may be necessary. 
     The same set of connectors  500  illustrated in FIG. 2 is used in all of the telephone models in the family, although not all of the connectors  500  is used in each model. For example, the most basic telephone model does not have any card edge connectors  500 D, as these connectors are used in the implementation of option modules bays. In each of the telephone models, the connectors  500  are accessed from below, through the connector support structures  502 , whether the telephone model utilizes a single-sided PWB or a double-sided PWB, as illustrated in FIG. 2 for a single-sided PWB. 
     FIG. 3 is a top perspective view of the Mod 6-pin connector  500 B of FIG. 2 mounted on the single-sided PWB  400 A, showing a portion of the upper surface  404 A of the PWB  400 A. FIG. 4 is a bottom perspective view of the connector  500 B mounted on the single-sided PWB  400 A, showing a portion of the lower surface  406 A of the PWB  400 A. FIG. 5 is a side view of the connector  500 B mounted on the single-sided PWB  400 A. The connector  500 B comprises a body  600 , a set of six signal leads  602 , a support tab  608  and a pair of pickup surfaces  614 A and  614 B. The pickup surface  614 B is located at the far wall of the well or opening into which the male connector is inserted (at a wall that defines an X-Y plane). The PWB  400 A has a set of signal pads  604 , a set of six etch runs  606  and a pair of support pads  610  on the upper surface  404 A. The PWB  400 A also defines an opening  612  through which the connector  500 B extends. 
     As illustrated in FIG. 4, the body  600  of the connector  500 B generally defines a box-type shape (ie. a three dimensional rectangular shape), with an opening for the insertion of a corresponding male connector. For reference purposes, a Cartesian coordinate system is identified in FIGS. 3 and 4. The size of the connector  500 B in the Z direction will be referred to as the height, the size of the connector  500 B in the X direction will be referred to as the width; and the size of the connector  500 B in the Y direction will be referred as the length. As further illustrated in FIG. 4, the width and length of the body  600  of the connector  500 B are slightly less than the corresponding dimensions of the opening  612 . As illustrated in FIG. 3, the signal leads  602  and the support tab  608  extend further in the negative and positive Y directions, respectively, then both the body  600  and the opening  612 . 
     During assembly of a telephone having the connector  500 B and the single-sided PWB  400 A, the PWB  400 A is placed with the upper surface  404 A facing upward. As illustrated in FIG. 3, the signal pads  604  and the support pads  610  are on the upper surface  404 A of the PWB  400 A. A surface mount technology (SMT) nozzle is applied to the pick up surface  614 A of the connector  500 B. The SMT nozzle is then used to place the connector  500 B into the opening  612  defined by the PWB  400 A, with the leads  602  overlaying the pads  604  and the support tab  608  overlaying the support pads  610 . The dimensions of the connector  500 B are generally smaller than the dimension of the opening  612  so that the body  600  of the connector  500 B extends through the PWB  400 A, except that the leads  602  and the support tab  608  extend beyond the dimensions of the opening  612 . After reflow, the leads  602  are secured to the pads  604 , making electrical contact, and the support tab  608  is secured to the support pads  610 . The leads  602  and the support tab  608  are secured to the upper surface  404 A of the PWB  400 A, with the body  600  of the connector  500 B extending through the PWB  400 A in a positive Z direction. 
     FIG. 6 is a bottom perspective view of the same Mod 6-pin connector  500 B mounted on a double-sided PWB  400 B, showing a portion of a lower surface  406 B of the PWB  400 B. FIG. 7 is a side view of the connector  500 B mounted on the double-sided PWB  400 B. The PWB  400 B has a set of six signal pads  604 , a set of six etch runs  606  and a pair of support pads  610  (one of which is partially illustrated FIG. 6) on the lower surface  406 B. Unlike the single-side PWB  400 A, the PWB  400 B does not define an opening, such as the opening  612  of the single-sided PWB  400 A. The PWB  400 B also has an upper surface  404 B. 
     During assembly of a telephone having the connector  500 B and the double-sided PWB  400 B, the PWB  400 B is placed with the upper surface  404 B facing downward. An SMT nozzle is applied to the pick up surface  614 B of the connector  500 B. The SMT nozzle is then used to place the connector  500 B onto lower surface  406 B of the PWB  400 B, with the leads  602  overlaying the pads  604  and the support tab  608  overlaying the support pads  610 . After reflow, the leads  602  are secured to the pads  604 , making electrical contact, and the support tab  608  is secured to the support pads  610 . 
     Whether the PWB utilized in a specific telephone model is single-sided or double-sided, the connector  500 B extends away from the lower surface  406  of the PWB  400 , with access at the bottom. When the entire telephone is assembled, the connector  500 B extends down into the support structure  502 B. The opening defined by the support structure  502 B again provides access to the connector  500 B at the bottom of the telephone. However, depending on whether the PWB is single-sided or double-sided, the connector  500 B may be mounted on the upper surface  404  or the lower surface  406  of the PWB  400 . Thus, the connector  500 B of the present invention and the method of mounting the connector  500 B to a PWB  400  allows the connector  500 B to be mounted on the upper surface  404 A of a single-sided PWB  400 A or on the lower surface  406 B of a double-sided PWB  400 B, while providing connector access from the bottom. 
     When using a single-sided PWB  400 A, the upper surface  404 A of the PWB  400 A is selected as the signal layer so that telephone key pads and other telephone keys can be mounted on the upper surface  404 A, providing access at the top of the telephone, through the upper housing component  200 . As a consequence, the connectors  500  must also be mounted on the upper surface  404 A. When using a double-sided PWB  400 B, both the upper surface  404 B and the lower surface  406 B are signal layers, so that the telephone key pad can be mounted on the upper surface  404 B while the connectors  500  are mounted on the lower surface  406 B. 
     The other connectors  500 A,  500 C and  500 D have similar design features to the connector  500 B. For example, a body of the connector  500 D has a generally box-type shape, although the connector  500 D is substantially more elongated than the connector  500 B. The single-sided PWB  400 A defines an opening for the connector  500 D that has dimensions that are slightly larger than the X-Y dimensions of the body of the connector  500 D. The connector  500 D also has a set of signal leads that extend further in the X-Y plane than the body of the connector  500 D. In addition, the connector  500 D also has a set of two pickup surfaces  614 A and  614 B, which are identified in FIG.  9 . 
     FIG. 8 is a perspective view of a preferred embodiment option module  800  that can be inserted into an option module bay of the telephone  90  of FIGS. 1 and 2FIGS. 9 and 10 illustrate the electronic interconnection between the option module  800  and the telephone  90 . The option module  800  comprises a PWB  804 , a card edge connector  500 D and an interconnection device  802 . The interconnection device  802  is a PWB with two sets of pads  806 ,  808  and a set of etch runs interconnecting the two sets of pads. A first set of pads  806  engages with the electrical contacts of the card edge connector  500 D of the option module  800 . When the option module  800  is inserted into an option module bay at the underside of the telephone  90 , a second set of pads  808  engages with the electrical contacts of one of the card edge connectors  500 D of the telephone  90 , depending on which option module bay is selected. The card edge connector  500 D of the option module  800  is mounted to a surface of the PWB  804  that is facing the PWB  400  when the option module  800  is inserted into the option module bay. The interconnection device  802  is secured within the option module  800 , with the second set of pads  808  extending therefrom to enable engagement with a card edge connector  500 D of the telephone  90  at the underside of the telephone  90 . The interconnection device  802  is angled to account for the angle defined between the PWB  400  of the telephone  90  and the PWB  804  of the option module  800 , when the option module  800  is inserted into the option module bay of the telephone  90 . The angle of the interconnection device  802  enables the pads  808  to be substantially perpendicular with the PWB  804  and the pads  806  to be substantially perpendicular with the PWB  400  when the option module  800  is inserted into the telephone  90 . 
     FIG. 9 illustrates the interconnection between the option module PWB  804  and the single-sided telephone PWB  400 A from the left side of the telephone  90 . FIG. 10 illustrates the interconnection between the option module PWB  804  and the double-sided telephone PWB  400 B, also from the left side of the telephone  90 . As illustrated in FIGS. 9 and 10, the pads  808  do not extend as far into the connector  500 D attached to the single-sided PWB  400 A as they do in the connector  500 D attached to the double-sided PWB  400 B. This situation arises because the connector  500 D is mounted to the upper surface  404 A of the single-sided PWB  400 A and the lower surface of  406 B of the double-sided PWB  400 B. To account for this difference in penetration of the pads  808  into the connector  500 D, the internal contacts of the connector  500 D have a relatively large area for contact with the pads  808 . The relatively large contact surface area of the connector  500 D provides sufficient contact with the pads  808  whether the connector  500 D is mounted to a single-sided PWB  400 A or a double-sided PWB  400 B.