Patent Publication Number: US-2013249582-A1

Title: Auxiliary element of printed circuit board module

Description:
BACKGROUND 
     1. Technical field 
     The disclosure generally relates to auxiliary elements of printed circuit boards, and particularly to an auxiliary element of a printed circuit board to be measured. 
     2. Description of the Related Art 
     Many printed circuit boards (PCB) define a plurality of different sized vias. As part of quality testing of mass produced PCBs, a certain number of PCBs may need to be cut to expose cross sections of the vias to be measured. The PCBs checked in this manner are damaged beyond repair and cannot be used. 
     Therefore, there is room for improvement within the art. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Many aspects of an exemplary auxiliary element can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the exemplary auxiliary element. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views. Wherever possible, the same reference numbers are used throughout the drawings to refer to the same or like elements of an embodiment. 
         FIG. 1  is a schematic view of an auxiliary element of a printed circuit board, according to an exemplary embodiment. 
         FIG. 2  is a cross section of the auxiliary element shown of  FIG. 1  taken along line II-II. 
         FIG. 3  is a schematic view illustrating specifications of test holes of the auxiliary element shown in  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  shows an auxiliary element  100  of a printed circuit board (PCB)  200  defined a plurality of vias  201 , according to an exemplary embodiment. The vias  201  are of different shapes and sizes, for example, one such via  201  may have a diameter of 10±3 mils (1 mil=0.001 inch), and another via  201  may have a diameter of 35±3 mils. 
     The auxiliary element  100  includes a test board  11 . The test board  11  can be may be an integral part of the PCB  200  or a separate part but produced together with the PCB  200 . In this embodiment, the test board  11  is integral with the PCB  200  and is located at a side of the PCB  200 . The test board  11  defines a plurality of test holes  111  with different shapes and sizes, which correspond to the vias  201 . Each unique size and shape of the vias  201  have a corresponding test hole  111  in the test board  11 . That is the holes  111  are made in the same way as the vias are made, so that if any holes  111  are found to be out of spec then it is known that the corresponding vias  201  are out of spec as well. If no holes  111  are out of spec for a certain PCB  200 , then that PCB  200  is proven qualified without destructive testing. 
     Also referring to  FIG. 2 , the auxiliary element  100  functions as follows: 
     The test board  11  is separated from the PCB  200  and is cut to expose cross sections of the test holes  111  to be measured. The test board  11  is cut by a cutting tool (not shown), for example, a knife. The test holes  111  are measured using a measuring tool (not shown), such as a micrometer. 
     Referring to  FIG. 3 , a size specification of the test holes  111  is shown. If a triangle-shaped test hole  111  has a measured diameter of 12 mils, and the spec 14.0±3.0 mils in  FIG. 2 , the triangle-shaped test hole  111  and its corresponding vias  201  are qualified. 
     The test board  11  defines the plurality of test holes  111  with different shapes and sizes. The vias  201  of the same shape and size correspond to one of the plurality of test holes  111  having the same shape and size as the vias  20 . The test board  11  is cut to measure sizes of the test holes  111 , if the test holes  111  are qualified, the corresponding vias  201  are qualified. There is no damage to the PCB  200  during the measuring process. 
     It is to be understood, however, that even though numerous characteristics and advantages of the exemplary disclosure have been set forth in the foregoing description, together with details of the structure and function of the exemplary disclosure, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of exemplary disclosure to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.