Abstract:
An unallocatable space depicting system is provided for depicting an unallocatable space for a component. The component forms a component shape on a printed circuit board layout. The unallocatable space depicting system includes a detecting module, a comparison module, and an incorporating module. The detecting module is used for detecting used shapes in the component shape and a gap in the used shape. The comparison module is used for comparing a width of a detected gap with a required width. The incorporating module is used for incorporating the gap whose width is less than the required width with the used shape to construct the unallocatable space. A related unallocatable space depicting method and a storage medium recorded with an application program for accomplishing the unallocatable space depicting method are also provided.

Description:
FIELD OF THE INVENTION 
   This invention relates to printed circuit board design systems and methods and, more particularly, to a computer-enabled depicting system for depicting an unallocatable space for a component on a printed circuit board and a depicting method thereof. 
   DESCRIPTION OF RELATED ART 
   Printed circuit boards (PCBs) are widely used in various electronic apparatuses, such as computers, information storage apparatuses, mp3s, cell phones, and televisions. In general, a printed circuit board carries and electrically interconnects a plurality of components including resistors, capacitors, integrated circuits (ICs), and connectors. 
   A general electronic apparatus includes not only one or more PCBs having some components mounted thereon but also some mechanisms. Each component of the PCBs and each mechanism occupy a specific space inside the electronic apparatus. When designing a PCB for an electronic apparatus, especially for an electronic apparatus in a compact and irregular structure, spaces occupied by the components on the PCB should be considered. For example, before a placement of a capacitor having a height of 20 mm on the PCB, an unallocatable space having a height not less than 20 mm should be indicated so as to provide references for selecting and design of other components on the printed circuit board. It is a tedious task to depict the unallocatable spaces of the components mounted on the PCB, especially when the components have irregular shapes. 
   Therefore, an unallocatable space depicting system and method for depicting the unallocatable spaces of the components is desired. 
   SUMMARY OF THE INVENTION 
   An unallocatable space depicting system is provided for depicting an unallocatable space for a component. The component forms a component shape on a printed circuit board layout. The unallocatable space depicting system includes a detecting module, a comparison module, and an incorporating module. The detecting module is used for detecting used shapes in the component shape and a gap in the used shape. The comparison module is used for comparing a width of a detected gap with a required width. The incorporating module is used for incorporating the gap whose width is less than the required width with the used shape to construct the unallocatable space. 
   An unallocatable space depicting method includes steps of: detecting the component shape to determine whether there is a space between each two used shape when the number of the used shapes is more than one; comparing a width of the detected space with the required width; and incorporating the detected space with the used shapes to construct the unallocatable space, when the width of the detected space is less than the required width. 
   A storage medium that is recorded with an application program is provided. The application program has a computer executable steps of: detecting the component shape to determine whether there is a space between each two used shape when the number of the used shapes is more than one; comparing a width of the detected space with the required width; and incorporating the detected space with the used shapes to construct the unallocatable space, when the width of the detected space is less than the required width. 
   Other advantages and novel features will become more apparent from the following detailed description of preferred embodiments when taken in conjunction with the accompanying drawings, in which: 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Many aspects of the unallocatable space depicting system and the unallocatable space depicting method thereof can be better understood with reference to the following drawings. The components in the drawings are not necessarily to scale, the emphasis instead being placed upon clearly illustrating the principles of the present disc drive. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views. 
       FIG. 1  is a cross sectional view of a component mounted on a PCB; 
       FIG. 2  is a schematic diagram showing a first component shape on the PCB, the first component shape including a body shape and a plurality of pin shapes; 
       FIG. 3  is a block diagram of an unallocatable space depicting system in accordance with an exemplary embodiment; 
       FIG. 4  is a schematic diagram showing the component shape of  FIG. 2  with the body shape and the pin shapes filled with specific patterns; 
       FIG. 5  is a schematic diagram showing a first unallocatable space of the component of  FIG. 1 ; 
       FIG. 6  is a schematic diagram showing a second unallocatable space of the component of  FIG. 1 ; 
       FIG. 7  is a flow chart illustrating a depicting procedure of the unallocatable space depicting system of  FIG. 3 ; 
       FIG. 8  is a schematic diagram showing a second component shape of a second component on the PCB, with pin shapes being covered by a body shape of the second component shape; and 
       FIG. 9  is a schematic diagram showing an unallocatable space for the second component of  FIG. 8 . 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Reference will now be made to the drawings to describe the preferred embodiment of the present unallocatable space depicting system, in detail. 
   Referring to  FIG. 1  and  FIG. 2 , a first component  10  mounted on a PCB (not shown) includes a body  12  and a plurality of pins  14  soldered on the PCB via pads (not labeled). The first component  10  is mounted on the PCB and forms a first component shape  20  on the PCB. The component shape  20  represents a bottom shape of the first component  10 , and includes a body shape  22  covered by the body  12  and a plurality of pin shapes  24  covered by the pads. The pin shapes  24  and the body shapes  22  are spaced by a plurality of first unused spaces  26 . Each pair of adjacent pin shapes  24  is spaced by an unallocated space  28  with a width of D 1 . In this exemplary embodiment, for ease of description, the widths of the first unused spaces  26  are identical, and the widths of the second unused spaces  28  are identical. In other alternative embodiments, widths of the first unused spaces  26  and the second unused spaces  28  may be different to each other. 
   Referring to  FIG. 3 , a block diagram of an unallocatable space depicting system  100  in accordance with an exemplary embodiment is illustrated. The unallocatable space depicting system  100  includes an input module  110 , a detecting module  120 , a comparison module  130 , an incorporating module  140 , and a setting module  150 . The input module  110  is used for entering a required width D. The required width D represents a minimum width of a space that is allocatable to other components or mechanisms. For example, if the width D 1  of the second unused space  28  is less than the required width D, the second unused space  28  is not allocatable to other components or mechanisms. The input module  110  is also used for entering a given height of the first component  10 . 
   The detecting module  120  is used for detecting the first component shape  20  of the first component  10  to find used shapes (such as the body shape  22 , and the pin shapes  24 ). When any used shape is found, the detecting module  120  fills the used shapes with specific patterns to distinguish the used shapes from other areas (referring to  FIG. 4 ). The detecting module  120  is also used for identifying the used shape representing the body shape based on an area of each used shape. The used shape with a greatest area is the body shape  22 . The other used shapes position at a periphery of the body shape, are identified as the pin shapes  24  by the detecting module  120 . The detecting module  120  is further used for detecting the width D 1  of the second unused space  28  between each pair of adjacent pin shapes  24 . 
   The comparison module  130  is used for determine whether the width D 1  of the second unused space  28  between each pair of adjacent pin shapes  24  are less than the required width D. 
   Because the first unused spaces  26  are covered by the pins  14 , they cannot be allocatable to other components and mechanisms. In order to reduce lines to construct an unallocatable space of the first component  10 , the spaces around the first component shape  20 , those unallocatable to other components and mechanisms should be incorporated into the unallocatable space. The incorporating module  140  is used for incorporating the first unused spaces  26  with the first component shape  20  to construct a first unallocatable space  40  (referring to  FIG. 5 ). The incorporating module  140  is also used for incorporating the second unused spaces  28  between each pair of adjacent pin shapes  24  with the first unallocatable space  40  to construct a second unallocatable space  50  if the width D 1  of the second unused space  28  is less than the required width D (referring to  FIG. 6 ). 
   The setting module  150  is used for setting a height of the unallocatable space of the first component  10  based on a height of the first component  10 . The height of the first component  10  can be obtained from the input module  110 , or from a predetermined height that is previously stored in the unallocatable space depicting system  100 . The setting module  150  is also used for setting a height range between a maximum height and a minimum height. 
   Referring to  FIG. 7 , a depicting procedure of the unallocatable space depicting system of  FIG. 3  is illustrated. Firstly, in step  70 , the input module  110  receives a required width D. Secondly, in step  72 , the detecting module  120  detects the first component shape  20  to find the used shapes. When the used shapes are found, in step  74 , the detecting module  120  fills the used shapes with the specific patterns to distinguish the used shapes from other areas. Then, in step  76 , the detecting module  120  distinguishes the body shape  22  from the pin shapes  24 . Successively, in step  78 , the incorporating module  140  incorporates the first unused spaces  26  with the used shapes to construct the first unallocatable space  40 . Then in step  710 , the detecting module  120  detects the width D 1  of the second unused space  28 . 
   In step  712 , a conclusion is made as to whether the width D 1  of the second unused space  28  is less than the required width D. If the width D 1  of the second unused space  28  is less than the required width D, the procedure proceeds to step  714 , otherwise the procedure proceeds to step  716 . In step  714 , the incorporating module  140  incorporates the second unused spaces  28  with the first unallocatable space  40  to construct the second unallocatable space  50 . 
   Then in step  716 , a conclusion is made as to whether the height or the height range of the first component  10  is received from the input module  110 . If the height or the height range of the first component  10  is received, the procedure proceeds to step  720 , otherwise the procedure proceeds to step  718 . In step  718 , the setting module  150  reads the previously stored height or the height range of the first component  10 . Finally, in step  720 , the setting module  150  sets the height of the first or second unallocatable space  40  or  50 . 
   As for the first component  10 , the pin shapes  24  are located around the body shapes  22 . There are some other components whose pin shapes are covered by their body shape. Such components include connectors and components mounted on an IC that is in a ball grid array (BGA) package. In such instance, the pin shapes are not shown, and the depicting module finds only one used shape. After finding the used shape, the depicting module  120  detects the used shape to determine whether there is a gap. If a gap is detected, the comparison module  130  determines whether a width of the gap is less than the required width D. If the width of the gap is less than the required width D, the gap with a width that is less than the required width D is incorporated with the used shape by the incorporating module  140  to construct the unallocatable space of the component. 
   Referring to  FIGS. 3 ,  8  and  9 , an exemplary second component shape  82  for a second component whose pin shapes (not shown) are covered by its body shape (referred as to the second component shape)  82 . The detecting module  120  detects the second component shape  82  to find used shapes. The component shape  82  is the only one used shape. Then the detecting module  120  detects the component shape  82  to determine whether there is a gap in the component shape  82 . When a first gap  84  with a first width D 2  and a second gap  86  with a second width D 3  are detected, the comparison module  130  compares the first width D 2  and the second width D 3  with the required width D to determine whether the first width D 2  and the second width D 3  are less than the required width D. After comparison, the first width D 2  is concluded less than the required width D while the second width D 3  is concluded greater than the required width D. Then the incorporating module  140  incorporates the first gap  84  with the second component shape  82  to construct an unallocatable space  80  for the second component. 
   The embodiments described herein are merely illustrative of the principles of the present invention. Other arrangements and advantages may be devised by those skilled in the art without departing from the spirit and scope of the present invention. Accordingly, the present invention should be deemed not to be unallocatable to the above detailed description, but rather by the spirit and scope of the claims that follow, and their equivalents.