Abstract:
An electrical connector mountable to a substrate. The electrical connector comprises a housing, a surface mount contact secured to the housing and adapted to surface mount to the substrate, and a non-surface mount hold down secured to the housing and adapted to mount to the substrate. The surface mount contact includes a fusible element, for example, a solder ball, a plurality of which may form a matrix array. The connector may be a ball grid array connector. A method of mounting an electrical connector to a substrate. The method comprises providing a substrate, and an electrical connector having a contact and a hold down. The method further comprises securing the contact to the substrate, placing the hold down into the substrate, and securing the hold down to the substrate. A method of preventing the skewing of an electrical connector when being mounted to a substrate. The method further comprises providing an electrical connector having a first part with a mass greater than a second part, and balancing the first and second parts of the electrical connector such that the electrical connector remains substantially parallel to the substrate when mounting to the substrate. An electrical connector mountable to a substrate. The electrical connector comprises a housing having a mounting end facing the substrate, and a plurality of contacts secured to the housing. The electrical connector further comprises a plurality of fusible elements, each secured to a respective one of the plurality of contacts, and a standoff extending a distance from the mounting end of the housing. An improved ball grid array connector mountable to a substrate. The improvement comprises a hold-down adapted to enter an opening in the substrate. The hold-down may be adapted to enter the opening without an interference fit

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority under 35 U.S.C. § 119(e) to U.S. Provisional Patent Applications Ser. No. 60/160,482, which was filed on Oct. 19, 1999. In addition, the subject matter disclosed herein is related to the subject matter disclosed in application Ser. No. 09/692,529, filed on Oct. 19, 2000. Both applications are herein incorporated by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to electrical connectors. More specifically, the invention relates to electrical connectors with strain relief features. 
     2. Brief Description of Earlier Developments 
     Various types of electrical connectors rely upon surface mount technology (SMT) to secure the connector&#39;s contacts to an underlying substrate. SMT connectors provide numerous benefits over earlier connectors, such as simplified manufacturing and lower costs. 
     While providing such advantages, the use of SMT may raise other issues. One concern, for example, involves the ability of the solderjoint between the contact and the underlying substrate to absorb forces caused by, for example, shipping, handling, mating and thermal cycling. Should one solderjoint become unusable as a result of damage from any of these events, the entire connector adversely may be affected. 
     Ball grid array (BGA) technology is one type of SMT. Generally speaking, an electrical connector using a BGA has a housing with a contact therein. A fusible element, typically a solder ball, secures to each contact. The solder balls serve as the primary connection between the contact and the surface of the substrate. A reflow process fuses the solder ball to the substrate. During the reflow process, a beneficial “self-centering” feature of BGA technology occurs. Specifically, as the solder reflows, the surface tension of the solder helps to align the connector properly with the conductive pads on the underlying substrate. 
     As with SMT connectors, forces on the solder joint in a BGA connector also poses a concern. Because of the self-centering ability of BGA connectors, however, many of the solutions used in SMT connectors cannot be used on BGA connectors. Therefore, a need exists to develop techniques for providing strain relief to BGA connectors. 
     SUMMARY OF THE INVENTION 
     The invention overcomes the above-mentioned limitations in the earlier developments and provides techniques for providing strain relief to BGA connectors. In particular, the invention provides a connector body with a retention post that may be inserted into a through hole in a printed circuit board (PCB). The post fits in the through hole without an interference fit. The post diverts some of the forces acting on the solder joint between the contacts and the PCB pads by allowing the connector body and the PCB to absorb some of the forces. 
     It is an object of the invention to provide an electrical connector with strain relief features. 
     It is a further object of the invention to provide a ball grid array electrical connector with strain relief features. 
     It is a further object of the invention to provide strain relief features to a ball grid array electrical connector compatible with the self-centering capability of the connector. 
     It is a further object of the invention to provide an electrical connector made with simplified manufacturing steps. 
     These and other objects of the invention are achieved in one aspect of the invention by an electrical connector mountable to a substrate. The electrical connector comprises a housing, a surface mount contact secured to the housing and adapted to surface mount to the substrate, and a non-surface mount hold down secured to the housing and adapted to mount to the substrate. The surface mount contact includes a fusible element, for example, a solder ball, a plurality of which may form a matrix array. The electrical connector is constructed such that it remains substantially parallel when mounted to the substrate. The electrical connector may further comprise a standoff secured to the housing. The standoff is adapted to retain the housing a distance from a surface of the substrate or to limit flattening of a solderjoint between the surface mount contact and the substrate. The standoff may be a part of the hold-down. The non-surface mount hold down of the electrical connector may be a post extending outwardly from the housing and is adapted to enter a hole in the substrate. 
     These and other objects of the invention are achieved in another aspect of the invention by a ball grid array connector mountable to a substrate. The ball grid array comprises a housing and a plurality of contacts within the housing. The ball grid array further comprises a plurality of fusible elements secured to the contacts for mounting the connector to the substrate, and a hold down adapted to enter the substrate. The hold down is secured to the housing. The ball grid array connector may further comprise a standoff extending from the housing and adapted to retain the housing a distance from a surface of the substrate or to limit flattening of the fusible elements during reflow. The standoff may be a part of the hold-down. The hold down may be a post extending outwardly from the housing. The fusible elements may be solder balls. Furthermore, the ball grid array connector may be constructed such that it remains substantially parallel when mounted to the substrate. 
     These and other objects of the invention are achieved in another aspect of the invention by a method of mounting an electrical connector to a substrate. The method comprises providing a substrate, and an electrical connector having a contact and a hold down. The electrical connector may be a ball grid array connector. The method further comprises securing the contact to the substrate, placing the hold down into the substrate, and securing the hold down to the substrate. The securing may comprise soldering the hold down to the substrate. The method may further comprise constructing the electrical connector such that it remains substantially parallel when mounted to the substrate. Also, the method may comprise balancing the electrical connector on the substrate such that the electrical connector remains substantially parallel to the substrate during the securing. Furthermore, the securing of the contact may occur before the securing of the hold down. 
     These and other objects of the invention are achieved in another aspect of the invention by a method of preventing the skewing of an electrical connector when being mounted to a substrate. The method comprises providing an electrical connector having a first part with a mass greater than a second part, and balancing the first and second parts of the electrical connector such that the electrical connector remains substantially parallel to the substrate when mounting to the substrate. The balancing may comprise removing material from the first part of the electrical connector and/or adding material to the second part of the electrical connector. The electrical connector may be a ball grid array connector. 
     These and other objects of the invention are achieved in another aspect of the invention by an electrical connector mountable to a substrate. The electrical connector comprises a housing having a mounting end facing the substrate, and a plurality of contacts secured to the housing. The electrical connector further comprises a plurality of fusible elements, each secured to a respective one of the plurality of contacts, and a standoff extending a distance from the mounting end of the housing. The standoff may allow partial flattening of the fusible elements. The distance may be selected so as to limit flattening of the fusible elements during reflow, or to prevent bridging between adjacent fusible elements. The fusible elements may be, for example, solder balls. 
     These and other objects of the invention are achieved in another aspect of the invention by an improved ball grid array connector mountable to a substrate. The improvement comprises a hold-down adapted to enter an opening in the substrate. The hold-down may be adapted to enter the opening without an interference fit. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Other uses and advantages of the invention will become apparent to those skilled in the art upon reference to the specification and the drawings, in which: 
     FIG. 1 is an exploded, top perspective view of a first alternative embodiment of the invention; 
     FIG. 2A is a bottom, perspective view of the electrical connector in FIG. 1; 
     FIG. 2B is a bottom, perspective view of an alternative embodiment of the electrical connector in FIG. 1; 
     FIG. 3 is a partial cut-away view of the electrical connector in FIG. 1; 
     FIG. 4 is a top perspective view of a second alternative embodiment of the invention; 
     FIG. 5 is a bottom view of the electrical connector in FIG. 4; 
     FIG. 6A is a bottom perspective view of a third alternative embodiment of the invention; 
     FIG. 6B is a partial cut-away view of the electrical connector in FIG. 6; 
     FIG. 7 is a perspective view of an electrical connector modified to ensure that the connector remains substantially parallel to the substrate during a reflow process, according to the invention; and 
     FIGS. 8A-8C show a portion of a substrate so as to illustrate the self-centering characteristics of the inventive connector. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Each of the alternative embodiments described herein relate to surface mounted electrical connectors having strain relief features. Preferably, fusible elements, such as solder balls, secure the contacts to conductive elements on the substrate using ball grid array (BGA) technology. Because BGA connectors tend to precisely align relative to the conductive pads on the substrate during reflow (known as the “self-centering”), the strain relief features discussed herein preferably do not interfere with this desirable characteristic. An intrusive reflow is preferably used to secure the strain relief to the substrate. “Intrusive” refers to the placement of fusible material (e.g., solder paste) within an opening in the substrate (e.g., plated through hole). Each alternative embodiment will now be described in more detail below. 
     FIGS. 1-3 display electrical connector  300 . Connector  300  is a backplane header connector that preferably mates with a backplane receptacle connector (as shown in FIG.  5 ). Connector  300  can be used in a backplane system for example, to connect a daughtercard to a motherboard. 
     Connector  300  uses many of the features described in U.S. patent application Ser. No. 09/302,027, herein incorporated by reference. Accordingly, only a brief discussion of certain features of connector  300  is necessary for an understanding of the invention. 
     Connector  300  includes an insulative housing  301  with apertures  303  therethrough that accept signal contacts  305 , ground contacts  307  and ground shields  309 . The mating ends of signal contacts  305  and ground contacts  307  extend through housing  301  and correspond to the arrangement of lead-in apertures in a mating connector (as shown in FIG.  4 ). Ground shields  309  preferably remain within housing  301 , engage ground contacts  307  and act to surround signal contacts  305  in a differential pairing arrangement. 
     Connector  300  surface mounts to a substrate  325 , preferably using the BGA technology discussed in International Publication number WO 98/15991. This aspect of the invention differs from the through hole mounting of the contacts described in U.S. patent application Ser. No. 09/302,027. 
     In one possible manner of surface mounting, connector  300  could use a wafer  311  that latches to housing  301 . Wafer  311  could have latch arms  313  that engage suitable latch structure  315  on housing  301 . In addition, wafer  311  has apertures  317  therethrough corresponding to the locations of contacts  305 ,  307 . Specifically, the distal ends of contacts  305 ,  307  extend through apertures  317 . The distal ends of contacts  305 ,  307  preferably reside within apertures  317 , but could extend beyond apertures  317 . 
     In a manner similar to that described in International Publication number WO 98/15991, pockets on the bottom surface of wafer  311  can receive solder paste (not shown) provided during a squeegee operation. Thereafter, the pockets now filled with solder paste can receive, and temporarily retain, a fusible element  321 . A reflow operation then fuses solder balls  321  to contacts  305 ,  307 . Any other manner of securing fusible elements  321  to contacts  305 ,  307  could be used, however. 
     FIG. 2B provides an alternative embodiment of connector  300 . As shown in FIG. 2B, housing  301 ′ of connector  300 ′ is a single continuous structure. This is to be distinguished from connector  300 , as shown in FIG. 2A, where wafer  311  is shown as a separate portion of housing  301 . 
     Connector  300  can mount to substrate  325  having an array of conductive pads  327  connected to suitable traces (not shown) to transmit signals or for grounding purposes, for example. Pads  327  correspond to the array of fusible elements  321  secured to contacts  305 ,  307  on connector  300 . As an alternative, pads  327  could also be vias. 
     A reflow process, typically subsequent to the reflow process that fused solder balls  321  to contacts  305 ,  307 , fuses solder balls  321  to pads  327 . Typically, the pads have solder paste  326  thereon to accept and to temporarily secure solder balls  321  to substrate  325 . As described earlier, a squeegee drawn across a stencil (not shown) placed on the substrate provides suitable amounts of solder paste at desired locations. The reflow process fuses solder ball  321  to pad  327  on substrate  325 , thus creating an electrical path between contacts  305 ,  307  and substrate  325 . 
     Due to the mechanical loading requirements and durability requirement of backplane connectors, connector  300  may require strain relief features to protect the solder joints formed by solder balls  321 . Connector  300  may use intrusively reflowed hold downs. Housing  301  includes posts  323  adjacent to the four corners, or at any other suitable location. 
     When assembled, posts  323  extend past wafer  311  and reside within through holes  328  in substrate  325 . Preferably, posts  323  are made from a suitable solderable material, such as a metal or a metallized plastic. Significantly, the diameter of post  323  is smaller than the diameter of plated through hole  328  that receives post  323 . Stated differently, posts  323  are generally unrestrained within through holes  328  before the reflow step. This allows solder balls  321  to self-center upon reflow without interference. Despite the ability of posts  323  to move within through holes  328 , posts  323  do, however, provide rough alignment and guidance when placing connector  300  on substrate  325 . 
     The reflow process used to secure solder balls  321  to substrate  325  preferably also secures posts  323  to through hole  328  in substrate  325 . As with conductive pads  327 , through holes  328  receive solder paste  329  during the squeegee operation. The reflow process fuses posts  323  to substrate  325 . 
     Posts  323  serve as the strain relief for connector  300 . Despite being an intrusive hold down, posts  323  allow solder balls  321  to self-centered during reflow. Prior to the reflow process, posts  323  extend into solder paste-filled tough holes  328 , while solder balls  321  rest upon solder paste  326  on conductive pads  327 . During the heating stage of the reflow process, solder paste  326  tends to liquefy before solder balls  321 . 
     While liquid, solder balls  321  will self-center relative to conductive pads  327  on substrate  325 . Posts  323 , being smaller than through holes  328 , allows movement of connector  300  without interference. 
     At the end of the reflow process, posts  323  tend to cool more slowly than solder balls  321 . As a result, the solder in this area stays liquid longer. This allows the benefit of an intrusive hold down, while retaining the self-centering characteristic of solder balls  321 . 
     FIG. 3 is a partial cut-away view of connector  300  providing greater detail of the construction and application of post  323 . As shown in FIG. 3, post  323  is fixedly attached to connector  300 , such as by placing a knurled section of post  323  into an opening in housing  301  after stenciling the solder paste. As connector  301  is placed upon substrate  325 , post  323  passes into through hole  328  in substrate  325 . Also, solder balls  321  align with conductive traces  327  on substrate  325 . Solder balls  321  rest on solder paste  326  placed on conductive traces  327 . Similarly, post  323  resides within solder paste  329  located in through hole  328 . As the connector system is heated, solder balls  321  liquify electrically couple to conductive pads  327 , and post  323  attaches to the interior of through hole  328 . 
     The system also may be designed such that post  323  secures to through hole  328  after solder balls  321  fuses to conductive pads  327 . In this way, post  323  also will provide strain relief to the connector system without inhibiting the self-centering characteristics of the BGA connector. The diameters of post  323  and through hole  328  are sized and toleranced so as to reduce any interference with the self-centering action of the BGA attachment techniques, while also ensuring hat solder balls  321  initially engage at least a portion of solder pad  327 . Also, the protrusion of post  323  into through hole  328  is such that optimum fillets will be formed inside and above through hole  328  without restricting the self-centering action. Post  323  is sized such that a significant amount of solder paste  329  will not be forced out of through hole  328  during the mounting process. For example, FIG. 3 shows that post  323  extends approximately halfway into through hole  328 . 
     FIGS. 4 and 5 display electrical connector  400 . Receptacle backplane connector  400  uses many of the features described in U.S. Pat. No. 6,116,926, herein incorporated by reference. Because a detailed discussion of many of the features of connector  400  are unnecessary for an understanding of the invention, only a brief summary of these features follows. 
     Connector  400  is modular, formed by a series of sub-assemblies  401 . Rear insulative housing  403  and front insulative housing  405  can latch together and surround sub-assemblies  401  to form connector  400 . Front housing  405  includes lead-in openings  407  that accept conductive contacts  305 ,  307  from mating connector  300  (as shown in FIG.  1 ). As shown, openings  407  form a differential pair arrangement. 
     Sub-assemblies  401  contain the ground and signal contacts (not shown). The ground and signal contacts mate with corresponding ground contacts  307  and signal conts  305  of mating connector  300  (as shown in FIG.  1 ). Differently than shown in U.S. Pat. No. 6,116,926, the contacts of connector  400  surface mount to a substrate (not shown). 
     In one possible manner of surface mounting, connector  400  could use a wafer  411  that latches to housing  401 . Wafer  411  could have latch arms (not shown) that engage suitable latch structure (not shown) on housing  401 . In addition, wafer  411  has apertures  413  therethrough corresponding to the locations of the contacts. Specifically, the distal ends of the contacts extend through apertures  413 . The distal ends of the contacts preferably reside within apertures  413 , but could extend beyond apertures  413 . 
     In a manner similar to that described in International Publication number WO 98/15991, apertures  413  can receive solder paste (not shown) provided during a squeegee operation. Thereafter, apertures  413 , now filled with solder paste, can receive and temporarily retain a fusible element  409 . A reflow operation then fuses solder balls  409  to the contacts. Any other manner of securing fusible elements  409  to the contacts could be used, however. 
     As with the earlier embodiments, connector  400  can mount to a substrate (not shown) having an array of conductive pads (not shown) connected to suitable traces (not shown) to transmit signals or for grounding purposes, for example. The pads correspond to the array of fusible elements  409  secured to the contacts on connector  400 . As an alternative, the pads could also be vias. 
     A reflow process, typically subsequent to the reflow process that fused solder balls  409  to the contacts, fuses solder balls  409  to the pads. Typically, the pads have solder paste (not shown) thereon to accept and to temporarily secure solder balls  409  to the substrate. As described earlier, a squeegee drawn across a stencil (not shown) placed on the substrate provides suitable amounts of solder paste at desired locations. The reflow process fuses solder ball  409  to the pad on the substrate, thus creating an electrical path between the contacts and the substrate. 
     As with connector  300 , connector  400  may require strain relief features to protect the solder joints formed between the contacts and the pads on the substrate. As with connector  300 , connector  400  utilizes intrusive, solderable hold downs. Housing  401  can include posts  415  adjacent the four corners, or any other suitable location. When assembled, posts  415  extend past wafer  411  and reside within through holes (not shown) in the substrate. Preferably, posts  415  are made from a suitable solderable material such as metal or metallized plastic. Significantly, the diameter of posts  415  is smaller than the diameter of the through hole. Stated differently, posts  415  generally are unrestrained within the through holes prior to reflow. As discussed below, this allows solder balls  409  to self-center upon reflow without interference. Despite the ability of posts  415  to move within the through holes, posts  415  do, however, provide rough alignment and guidance when placing connector  400  on the substrate. In fact, posts  415  and PCB through holes are sized to ensure that solder balls  409  initially engage at least a portion of the solder pad. 
     The reflow process used to secure solder balls  409  to the substrate preferably also secures posts  415  to the through hole in the substrate. As with the conductive pads, the through holes receive solder paste during the squeegee operation. The reflow process fuses posts  415  to the substrate. 
     Posts  415  serve as the strain relief for connector  400 . Despite being an intrusive hold down, posts  415  allow solder balls  409  to self-center during reflow. Prior to the reflow process, posts  415  extend into solder paste-filled through holes, while solder balls  409  rest upon solder paste on the conductive pads. During the heating stage of the reflow process, the solder paste tends to liquify before solder balls  409 . 
     While liquid, solder balls  409  will self-center relative to the conductive pads on the substrate. Posts  415 , being smaller than the through holes, allows movement of connector  400  without interference. 
     At the end of the reflow process posts  415  tend to cool more slowly than solder balls  409 . As a result, the solder in this area strays liquid longer. This allows the benefit of an intrusive hold down, while retaining the self-centering characteristic of balls  409 . 
     FIGS. 6A and 6B display electrical connector  500 . In particular, FIG. 6A provides a bottom perspective view of electrical connector  500 , and FIG. 6B provides a partial cut-away view of the connector. Connector  500 , while generally similar to connector  300 , is preferably used in situations, for example, where the weight of connector  500  may flatten solder balls  521  and cause bridging between adjacent solder balls  521 . 
     Accordingly, housing  501  of connector  500  can include a retention post  525  in addition to, or as a substitute for, posts  523 . Differenty than posts  523 , post  525  has a shoulder  526  that cannot enter plated through holes  528 . Shoulder  526  keeps connector  500  from substrate  527  when solder balls  521  liquefy to prevent bridging. In other words, a suitable post  525  acts as a standoff and prevents solder balls  521  from being flattened by the weight of the connector  500 . As with posts  523 , post  525  can be made from a solderable material. Preferably, shoulder  526  allows some flattening of the ball (e.g., up to approximately 40 percent and preferably approximately 30 percent) to ensure a proper solder joint with PCB pad. Shoulder  526  also can prevent skewing of connector  500  on substrate  527 , caused, for example, by a connector that is not uniformly balanced. The distal end of post  525  can enter plated through hole  528  and serve as a hold-down. 
     FIG. 7 is another example of how the invention ensures that the BGA connector remains substantially parallel to the substrate during reflow. As discussed with reference to connectors  300 ,  400  and  500 , the BGA connector is attached to the substrate by heating the solder balls until the solder melts and becomes fused to the conductive traces of the substrate. The surface tension of the solder centers the connector on the traces of the substrate. In situations where the connector design requires an arrangement where the weight of the connector is not uniformly balanced, the connector may become skewed with respect to the substrate during the reflow process. During reflow, a heavier portion of the connector could “flatten” the solder balls thereunder more so than the lighter portion. As a result, certain of the solder balls may not make proper contact with the substrate, possibly causing the solder joint to fail under a less than nominal mechanical force. Also, adjacent collapsed solder balls could bridge. The invention ensures that the BGA connector remains substantially parallel to the substrate during reflow. 
     As shown in FIG. 7, portions of connector  701  (shown dashed for purposes of clarity) may be added and/or removed to allow the mass of connector  701  to be evenly balanced over the ball grid array. In particular, a portion  702  may be removed from a heavier section of housing  701 . Portions  703  and  704  may be added to lighter sections of housing  701 . Although FIG. 7 shows portions  702 - 704  in certain locations, it should be appreciated that the location, as well as the size and weight of portions  702 - 704  will vary depending upon the physical characteristics of connector  701 . 
     Although FIG. 7 illustrates balancing connector  701  on the substrate by modifying the physical characteristics of the connector, it should be appreciated that the invention is not so limited. The invention may accomplish such balancing using a number of techniques. For example, an external force may be applied to certain areas of connector  701  during the reflow process. The magnitude of such a force would be determined so as to overcome the skewed relation of connector  701  and the substrate, caused by the imbalance of the connector over the ball grid array. In another embodiment, a similar force may be applied to the substrate, in addition to or instead of the connector. Therefore, the invention includes any technique that overcomes the inherent imbalance of the connector over its ball grid array, and allows the connector to be substantially parallel with the attached substrate after reflow. 
     FIG. 8A-8C show a portion of a substrate  800 , and illustrate the self-centering characteristics of the inventive connector during the reflow process. First, FIG. 8A shows substrate  800  without a connector soldered thereto. Substrate  800  includes plated through hole  801 , solder pads  802 , and conductive traces  805  (shown, for clarity, as only extending from certain pads  802 ). Solder pad  802  is adapted to receive a fusible element on a connector (e.g., as shown in FIG.  3 ), and conductive path  805  carries a signal along substrate  800 . Through hole  801  is adapted to receive a hold down on the connector. 
     FIG. 8B illustrates the next step in the process, namely the positioning of the connector with solder balls  803  and hold downs  804  (shown dashed for clarity) on top of substrate  800 . As shown in FIG. 8B, connector is positioned in a worst-case scenario with respect to substrate  800 , such that solder balls  803  and hold downs  804  are furthest from the center of solder pads  802  and through hole  801 , respectively. FIG. 8C illustrates the next step in the process, namely the reflow of solder balls  803  and the solder paste in the through holes that receive and hold downs  804 . As shown in FIG. 8C, although solder balls  803  and hold downs  804  initially were positioned in a worst case scenario (as shown in FIG.  8 B), the self-centering characteristic of the connector, moves solder balls  803  and hold downs  804  such that they are centered over solder pads  802  and within through hole  801 , respectively. Therefore, regardless of the initial positioning of the connector over substrate  800 , the self-centering characteristics of the reflow process permit solder balls  802  and hold downs  804  to center over solder pads  802  and within through hole  801 , respectively. 
     While the invention has been described in connection with the preferred embodiments of the various figures, it is to be understood that other similar embodiments may be used or modifications and additions may be made to the described embodiment for performing the same function of the invention without deviating therefrom. Therefore, the invention should not be limited to any single embodiment, but rather construed in breadth and scope in accordance with the recitation of the appended claims.