Abstract:
The process of prototyping circuits such as a backplane or a circuit board has been modularized for achieving marked reductions in costs, time, and construction errors. Rather than repeating the recurring tasks, such as making bus connections between different circuit boards, of the prototyping process, the present invention implements a plurality of modules which can be separably coupled into an assembly having a planar arrangement for prototyping circuits, where each module specializes in a particular task. In the preferred embodiment, the plurality of modules includes a data bus module, a switchable data bus module, a power bus module, and a wire-wrap module. Each one of the plurality of modules includes a coupling face configured for coupling to one or more circuit boards. Since the assembly is constructed by simply coupling one or more modules to one another, the present invention facilitates rapid and cost-effective prototyping of a variety of backplanes as well as facilitates reuse of the assembly in multiple prototyping processes by simply separating the one or more modules from one another. Moreover, the bus modules are internally configured to couple one or more circuit boards together, thus substantially lowering the need for wire-wrapping. Hence, the construction errors associated with wire-wrapping are substantially reduced, leading to quality improvements.

Description:
FIELD OF THE INVENTION 
     The present invention relates to the field of prototype development and to the field of circuits and backplanes. More particularly, the present invention relates to prototyping circuits and backplanes by constructing a reusable and modular assembly providing improvements in cost, time, and reliability. 
     BACKGROUND OF THE INVENTION 
     Before an electronic product having electronic components and circuit boards is set for mass production, considerable time and resources are expended during the prototype development phase (or prototyping) in demonstrating the operational feasibility of the electronic product. In this early stage of development, the electronic product is assembled in a manner facilitating verification, debugging, and evaluation of the functionality of the electronic product without regard or with a lesser regard for mass production considerations. This assembly which is accomplished for convenience purposes is known as breadboarding. In general, the electronic product undergoes extensive modification and reengineering in the course of the breadboarding process aimed to building a prototype of the electronic product which meets the engineering and product specifications assigned to the electronic product. 
     Typically, an electronic product that requires extensive breadboarding during the prototype development phase (or prototyping) is a backplane. In general, a backplane is a circuit board, usually implemented as a printed circuit board, which supports other circuit boards, including printed circuit boards, and electronic components by providing an assembly platform and providing interconnections among the other circuit boards and electronic components through one or more buses, usually including data, signaling, power, and ground buses. There are numerous types of backplanes, each suited for one or more applications. For example, particular backplanes specialize in handling analog signals, digital signals, or both analog and digital signals. In addition, some backplanes specialize in high speed data transmission. Backplanes vary in size and shape, properties which tend to depend on the particular application for which the backplane is designed. 
     Moreover, backplanes can be described as being either active or passive. Active backplanes include, in addition to receptacles for receiving a circuit board, logical circuitry that performs computing functions. In contrast, passive backplanes have almost no logic circuitry. More importantly, passive backplanes make it easier to repair faulty electronic components and to upgrade to new electronic components. 
     In prototyping a backplane, any one of several conventional techniques is utilized. Occasionally, multiple circuit boards are hard-wired directly to one another. Sometimes, a previously designed backplane is reused after being moderately or extensively modified. 
     More commonly, a custom backplane is designed and manufactured or a wire-wrap backplane is built during the process of prototyping a backplane. 
     Constructing a custom backplane is a slow and expensive procedure. Delay in verifying, debugging, and evaluating the custom backplane because of the time spent on designing and manufacturing the custom backplane impedes the product development process. Since the custom backplane undergoes many changes during the prototyping stage, several custom backplanes need to be designed and manufactured over the course of the prototyping stage, thus amplifying the costs in time and resources. 
     Similarly, building a wire-wrap backplane from a wire-wrap board has been a traditional way of prototyping a backplane. This point-to-point wiring technique demands considerable time and patience in appropriately connecting a plurality of wire-wrap pins with wire-wrap wire. One additional attribute of a wire-wrap backplane lies in its high susceptibility to errors during its construction. In particular, errors can arise from having a defective wire-wrap wire connecting any one of the wire-wrap pills or from establishing a wire-wrap connection between the wrong wire-wrap pins. Lastly, the wire-wrap backplane is not well suited for reuse in a different backplane application. 
     What is needed is a reusable and modular assembly for prototyping circuits and backplanes effectuating reductions in costs, time, and construction errors. 
     SUMMARY OF THE INVENTION 
     The process of prototyping circuits such as a backplane or a circuit board has been modularized for achieving marked reductions in costs, time, and construction errors. Rather than repeating the recurring tasks of the prototyping process, such as making bus connections between different circuit boards, the present invention implements a plurality of modules which can be separably coupled into an assembly having a planar arrangement for prototyping circuits, where each module specializes in a particular task. In the preferred embodiment, the plurality of modules includes a data bus module, a switchable data bus module, a power bus module, and a wire-wrap module. Each one of the plurality of modules includes a coupling face configured for coupling to one or more circuit boards. 
     Since the assembly is constructed by simply coupling one or more modules to one another, the present invention facilitates rapid and cost-effective prototyping of a variety of backplanes as well as facilitates reuse of the assembly in multiple prototyping processes by simply separating the one or more modules from one another. Moreover, the bus modules are internally configured to couple one or more circuit boards together, thus substantially lowering the need for wire-wrapping. Hence, the construction errors associated with wire-wrapping are substantially reduced, leading to quality improvements. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 illustrates a plurality of modules for prototyping according to the preferred embodiment of the present invention, showing the relationship between a first face of the modules and a plurality of printed circuit boards. 
     FIG. 2 illustrates the modules of FIG. 1, showing a second face of the modules. 
     FIG. 3 illustrates two of the pins on the assembly in a wire-wrapped connection with one another. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     In the area of prototyping backplanes and circuits, improvements over the prior art are achieved by implementing a modularization technique. Although the discussion will focus on the prototyping of backplanes, the modularization technique of the present invention is equally applicable to the prototyping of other categories of circuits and circuit boards. 
     According to the present invention, a plurality of modules are developed to modularize the process of prototyping a backplane. Each module serves as a self-contained unit, specializing in handling a particular task of the backplane prototyping process. In particular, each module includes a coupling face which is configured for receiving one or more circuit boards having a card-edge connector, i.e., a connector that facilitates communication between signals which originate within a particular circuit board and signals which originate within other circuit boards and that facilitates coupling to other circuit boards. It should be understood that the phrase “circuit boards” as used herein includes printed circuit boards and any other appropriate circuit board implementations. 
     In practice, a backplane is prototyped by building a reusable assembly comprising multiple modules that are coupled to one another to form a planar arrangement, where the building process is rapid and simple. Modules are coupled to one another in a pattern that corresponds to the configuration of the card-edge connectors of the one or more circuit boards. By coupling the circuit boards to the coupling face of the modules in the assembly, a backplane can be prototyped with reduced costs, time, and construction errors. 
     FIG. 1 illustrates a backplane prototyping assembly  100  which is modular and reusable according to the preferred embodiment of the present invention. The backplane prototyping assembly  100  comprises a plurality of modules  10   a , . . . ,  10   h , where each module  10   a , . . . ,  10   h  is separably coupled to one another to form a planar arrangement. Since the modules  10   a , . . . ,  10   h  are separably coupled to one another, the backplane prototyping assembly  100  is easily disassembled and reassembled for prototyping other backplane designs. The backplane prototyping assembly  100  of FIG. 1 illustrates the features of the present invention. However, the present invention is not limited to the backplane prototyping assembly  100  shown in FIG.  1 . For example in alternate embodiments, the number of modules  10   a , . . . ,  10   h  can be increased or decreased and the location of the modules  10   a , . . .  10   h  relative to one another within the backplane prototyping assembly  100  can be changed. 
     As illustrated in FIG. 1, the plurality of modules  10   a , . . . ,  10   h  form a planar arrangement. Preferably, the planar arrangement includes a first surface  20  configured for receiving one or more circuit boards  40  in a shelf arrangement, where the circuit boards  40  are circuit boards scheduled to be included in the backplane design to be prototyped with the backplane prototyping assembly  100 . Additionally, the planar arrangement includes a second surface  25  (FIG. 2) configured for facilitating formation of one or more electrical connections among the one or more circuit boards  40 . Preferably, the first surface  20  and the second surface  25  are formed on opposite faces of the plurality of modules  10   a  . . . ,  10   h . 
     Each circuit board  40  includes a card-edge connector  50  having a plurality of electrical terminals configured into one or more rows. In practice, each circuit board  40  is coupled to one or more modules  10   a , . . . ,  10   h , where a coupling orientation  30  between modules  10   a , . . . ,  10   h  is perpendicular to a coupling orientation  35  between the circuit board  40  and the module  10   a , . . . ,  10   h . This enables a modular approach to the prototyping of a backplane design since corresponding electrical terminals of each circuit board  40  can be electrically isolated within each module  10   a , . . . ,  10   h . Thus facilitating the electrical coupling of these corresponding electrical terminals. For example, electrical terminals of each circuit board  40  which correspond to a power bus can be electrically coupled to one or more of the modules  10   a , . . . ,  10   h  which specializes in handling power distribution while electrical terminals corresponding to a particular data bus can be electrically coupled to one or more of the modules  10   a , . . . ,  10   h  which specializes in handling the particular data bus. 
     Since a bus system which comprises a plurality of parallel connections between the one or more circuit boards  40  forms a substantial part of a backplane, the modules  10   a , . . . ,  10   h  of the present invention eliminate costs, time, and construction errors associated with the prior art methods of prototyping a backplane design. The prior art methods of prototyping a backplane design generally require building the entire backplane prototype at one time and do not allow design flexibility and rapid design alterations. In contrast, the present invention allows building the backplane prototype one modular unit at a time, thus permitting rapid alterations and changes to be made to portions of the backplane prototype without affecting the remainder of the backplane prototype. 
     As illustrated in FIG. 1, the first surface  20  of the planar arrangement is configured for coupling to the card-edge connector  50  of each circuit board  40 . In particular, each of the modules  10   a , . . . ,  10   h  includes a nonconductive housing having a first face, where the first face corresponds to the first surface  20  of the planar arrangement, and a second face, where the second face corresponds to the second surface  25  (FIG. 2) of the planar arrangement. Each first face (or coupling face) includes a plurality of electrical terminals configured into one or more rows for coupling to the electrical terminals of each card-edge connector  50 . Although each first face illustrated in FIG. 1 is configured with female-type electrical terminals and each card-edge connector  50  illustrated in FIG. 1 is configured with male-type electrical terminals, it should be understood by those skilled in the art that the electrical terminals of the first face and the card-edge connector  50  can be alternately configured as any appropriate coupling configuration. 
     As discussed above, preferably each of the plurality of modules  10   a , . . . ,  10   h  of the present invention is designed to specialize in a particular task. In the preferred embodiment of the present invention, the plurality of modules  10   a , . . . ,  10   h  include data bus modules  10   e ,  10   f , and  10   g ; a switchable data bus module  10   h ; a power bus module  10   d ; and wire-wrap modules  10   a ,  10   b , and  10   c . However, other types of modules can readily be designed and included to meet the needs of particular backplane prototyping processes, such as a signal bus module and a switchable signal bus module. 
     In practice, the multiple modules  10   a , . . . ,  10   h  are selected and separably coupled to one another according to the requirements of the particular backplane design undergoing the prototyping process. 
     The structure and configuration of the modules  10   a , . . . ,  10   h  can be better understood with reference to FIGS. 1 and 2. FIG. 1 illustrates the first surface  20  of the planar arrangement and the first face, which includes the electrical terminals, of the modules  10   a , . . . ,  10   h . FIG. 2 illustrates the second surface  25  of the planar arrangement and the second face of the modules  10   a , . . . ,  10   h  . 
     The data bus modules  10   e ,  10   f , and  10   g  include, along their longitudinal axis, a row of electrical terminals that are electrically coupled to one another inside the data bus modules  10   e ,  10   f , and  10   g . Thus, particular electrical terminals of each circuit board  40  can be coupled to the data bus module to verify, debug, and evaluate the data bus component of the backplane design under consideration. 
     The switchable data bus module  10   h  includes, along its longitudinal axis, a row of electrical terminals that selectively are electrically coupled to one another inside the switchable data bus module  10   h , and a plurality of switches  210 , where each of the switches  210  is coupled to a corresponding one of the electrical terminals of the row. Each of the switches  210  is configured to selectively couple the corresponding electrical terminal to the other electrical terminals of the row. As illustrated in FIG. 2, the second face of the switchable data bus module  10   h  provides access to each one of the plurality of switches  210 . The switches  210  make it possible to selectively remove or include any of the circuit boards  40  from the data bus component during verification, debugging, and evaluation of the data bus component of the backplane design under consideration. 
     The power bus module  10   d  includes, along its longitudinal axis, a row of electrical terminals that are electrically coupled to one another inside the power bus module  10   d . The row of electrical terminals is materially configured to support the voltage and current requirements of power distribution and ground distribution to each circuit board  40 . In particular, the electrical terminals of the power bus module  10   d  are designed to withstand the higher voltage and current values associated with power and ground distribution compared to the voltage and current values associated with other components of the backplane design. The power bus module  10   d  simplifies prototyping the power bus component of a backplane design. 
     The wire-wrap modules  10   a ,  10   b , and  10   c  include, along their longitudinal axis, a row of electrical terminals and a plurality of pins  220  extending from the second face of the wire-wrap modules  10   a ,  10   b , and  10   c , where each of the pins  220  is coupled to one of the electrical terminals of the row. Additionally, each of the pins  220  is configured for facilitating a wire-wrap connection. In particular, the plurality of pins  220  enable establishing non-bus and bus connections among the circuit boards  40 . More importantly, since the data bus modules  10   e ,  10   f , and  10   g ; the switchable data bus module  10   h ; and the power bus module  10   d  provide interconnectivity among the circuit boards  40 , the amount of wire-wrapping needed is substantially reduced. Hence, construction errors arising in building a prototype of the backplane design are reduced, improving the quality of the backplane prototype. 
     FIG. 1 illustrates one method of incorporating into the backplane prototyping assembly  100  one or more signals that do not originate from the one or more circuit boards  40 , such as power supply and output signals from another electrical system. As shown in FIG. 1, these signals are coupled to the first surface  20  through a connector  80 , where the connector is coupled to a ribbon cable  90 . Alternately, these signals (or external signals) can be wire-wrapped to the backplane prototyping assembly  100  through one of the wire-wrap modules  10   a ,  10   b , and  10   c . Similarly, other electronic components can be incorporated into the backplane prototyping assembly  100  through wire-wrapping or connectors coupled to the first surface  20 . 
     Preferably, each of the modules  10   a , . . . ,  10   h  includes a nonconductive housing which is materially composed of a molded plastic, providing electrical isolation to each of the modules  10   a , . . . ,  10   h . Alternatively, the nonconductive housing can be materially composed of any appropriate nonconductive material known to those skilled in the art. In addition, the electrical terminals of each of the modules  10   a , . . . ,  10   h  are materially composed of any appropriate conductive metallic material Moreover, the electrical terminals of each of the modules  10   a , . . . ,  10   h  can be configured to be compatible with any one of the card-edge connector standards, such as the 2 mm standard, .125 inch standard, or any other appropriate card-edge connector standard. 
     As illustrated in FIG. 2, the modules  10   a , . . . ,  10   h  can be designed to have different lengths. For example, the module  10   g  has a length that is {fraction (1/4 )}of the length of the other modules. Similarly, the modules  10   a , . . . ,  10   h  can be designed to have different widths to accommodate the particular card-edge connector of the circuit boards  40  or to enable the modules  10   a , . . . ,  10   h  to provide a variety of electrical terminals to each circuit board  40 . As should be apparent to those skilled in the art, a plurality of modules  10   a , . . . ,  10   h  including modules having a variety of lengths and widths will accommodate a greater variety of backplane designs. 
     As discussed above, each of the modules  10   a , . . .  10   h  is capable of coupling to another module  10   a , . . . ,  10   h  in such a manner which allows the modules to be easily separated from one another. This feature is implemented by utilizing screws, utilizing a mechanical coupling, incorporating an interlocking feature on the nonconductive housing, or using in any other appropriate coupling feature that is known to those skilled in the art. 
     The present invention modularizes the backplane prototyping process. This modularization is accomplished through the implementation of a plurality of modules, each specializing in a particular task. Since the modules are reusable, costs associated with designing and manufacturing a custom backplane at the prototyping phase are avoided. More importantly, a savings in time during the prototyping phase is achieved through the ease of handling and arranging the modules into a reusable assembly which is readily configurable for receiving one or more circuit boards associated with the backplane design under consideration. 
     The above figures are merely intended to illustrate a particular implementation of the present invention, but are not intended to limit the scope of the present invention to this particular implementation. 
     The present invention has been described in terms of specific embodiments incorporating details to facilitate the understanding of the principles of construction and operation of the invention. Such reference herein to specific embodiments and details thereof is not intended to limit the scope of the claims appended hereto. It will be apparent to those skilled in the art that modifications may be made in the embodiments chosen for illustration without departing from the spirit and scope of the invention.