Patent Publication Number: US-2007113675-A1

Title: Circuit board clamping mechanism and testing device using the same

Description:
This application claims the benefit of Taiwan application Serial No. 094138848, filed Nov. 04, 2005, the subject matter of which is incorporated herein by reference.  
     BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The invention relates in general to a circuit board clamping mechanism and a testing device using the same, and more particularly to a circuit board clamping mechanism firmly clamping an extending circuit board on a main circuit board by an L-shaped clamping element and a testing device using the same.  
      2. Description of the Related Art  
      Electronic products have brought great convenience to modern people in their daily life and work. Computer in particular has become an indispensable necessity in people&#39;s everyday life. Computer includes a host and a screen. The host further includes a main circuit board and at least an extension circuit board such as the display circuit board (VGA circuit board). The display circuit board is inserted or soldered to be coupled with the main circuit board. For example, the display circuit board is vertically inserted into the slot of the main circuit board. During the delivery of the host, when the host receives vibration or strong impact, the main circuit board and the display circuit board might be separated or cracking might occur to the soldering connection between the main circuit board and the display circuit board. Therefore, before a computer host leaves the factory, a series of vibration and impact tests are performed to assure that the display circuit board and the main circuit board remain intact after vibration or impact and their electrical functions are normal.  
      Conventional vibration or shock testing device provides a housing and a vibrational source or the shocking source. The shocking source provides a strong vibration within a short period of time. The disclosure below is exemplified by a vibration testing device and a vibrational source. The main circuit board is clamped on the housing, and the display circuit board is vertically inserted in the main circuit board. At the beginning, the vibrational source applies a vibrational force onto the housing, then the vibrational force is transmitted to the main circuit board via the housing first and transmitted to the display circuit board via the main circuit board next. The above design tests whether the display circuit board and the main circuit board coupled with the same still remain normal electrical functions during vibration.  
      However, the vibrational force decays when transmitted from the housing to the main circuit board and the display circuit board in sequence. The vibrational force actually received by the display circuit board is very different from the vibrational force predetermined to be received by the display circuit board, largely affecting the accuracy of vibration testing which may further affects product quality. The accuracy problem not only occurs to the vibration test of the display circuit board and the main circuit board but also occurs to the vibration test of any two circuit boards coupled together. Thus, how to provide a testing environment for the vibrational or shocking test of any two coupled circuit boards is an imminent issue with respect to the quality control of electronic products.  
     SUMMARY OF THE INVENTION  
      It is therefore an object of the invention to provide a circuit board clamping mechanism and a testing device using the same. The design of positioning the main circuit board by a substrate board and directly clamping the extending circuit board on the substrate board by a clamping element of the substrate board not only firmly clamps the extending circuit board and the main circuit board together but also accurately transmit the vibration or impact provided by a vibrational source or a shocking source onto the extending circuit board. Thus, the electrical functions of the extending circuit board and the main circuit board under a vibrational or a shocking state can be accurately measured such that the quality of electronic products is assured.  
      The invention achieves the above-identified object by providing a circuit board clamping mechanism for clamping a main circuit board and an extending circuit board. The extending circuit board is coupled with the main circuit board, and there is a titling angel between the extending circuit board and the main circuit board. The circuit board clamping mechanism includes a substrate board and a clamping element. The main circuit board is disposed on the substrata board. The clamping element includes a clamping part and a fixing part. The clamping part is for clamping the extending circuit board. The fixing part is disposed on the substrate board and is coupled with the clamping part. The clamping part and the fixing part form an L-shaped structure.  
      The invention further achieves the above-identified object by providing a testing device for testing the electrical functions of an extending circuit board under a vibrational state or a shocking state. The testing device includes a substrate board, a main circuit board, a clamping element, a testing platform and an inspecting unit. The main circuit board is disposed on the substrate board. The main circuit board is coupled with the extending circuit board, and there is a titling angel between the main circuit board and the extending circuit board. The clamping element includes a clamping part and a fixing part. The clamping part is for clamping the extending circuit board. The fixing part is disposed on the substrate board and is coupled with the clamping part. The clamping part and the fixing part form an L-shaped structure. The testing platform is coupled with the substrate board for providing a vibrational source or a shocking source to the substrate board. The inspecting unit is electrically connected to the extending circuit board and the main circuit board for inspecting the electrical functions of the extending circuit board under the vibrational state or the shocking state.  
      Other objects, features, and advantages of the invention will become apparent from the following detailed description of the preferred but non-limiting embodiments. The following description is made with reference to the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a block diagram of a testing device according to a preferred embodiment of the present embodiment of the invention; and  
       FIG. 2  is a structural diagram of a testing platform. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
      Referring to  FIG. 1 , a block diagram of a testing device according to a preferred embodiment of the present embodiment of the invention is shown. The testing device  100  is for testing the electrical functions of an extending circuit board  70  under a vibrational state or a shocking state. The testing platform  20  is for generating a vibrational source or a shocking source for testing. In the present embodiment of the invention, the testing platform  20  is exemplified by providing a vibrational source to a circuit board clamping mechanism  10  by a vibrator. The circuit board clamping mechanism  10  is for clamping a main circuit board  60  and an extending circuit board  70 , and transmitting the vibrational force to the main circuit board  60  and the extending circuit board  70 . The main circuit board  60  is coupled with the extending circuit board  70 . Examples of the main circuit board  60  include a computer main circuit board, an optical disc drive main circuit board or a mobile communication main circuit board. Examples of the extending circuit board  70  include a display circuit board, an Ethernet circuit board or a sound circuit board. In the present embodiment of the invention, the main circuit board  60  is exemplified by a computer main circuit board, and the extending circuit board  70  is exemplified by a display circuit card. The main circuit board  60  and the extending circuit board  70  are further electrically connected to an inspecting unit  30 . The inspecting unit  30  is for inspecting the electrical functions of the main circuit board  60  and the extending circuit board  70  under a vibrational state. Examples of the inspecting unit  30  include a monitor screen or an electrical signal inspection chip. The testing device  100  further includes a controlling unit  40  for driving the testing platform  20  and the inspecting unit  30 . The controlling unit  40  is powered by a power supplier  50 .  
      Referring to  FIG. 2 , a structural diagram of a testing platform is shown. The testing platform  20  is coupled with the circuit board clamping mechanism  10 , such that the testing platform  20  can transmit a vibrational force to the circuit board clamping mechanism  10 . The circuit board clamping mechanism  10  includes a substrate board  11  coupled with the testing platform  20  and the main circuit board  60  for transmitting the vibrational force provided by the testing platform  20  to the main circuit board  60 . In the present embodiment of the invention, the testing platform  20  is coupled with the substrate board  11  and is disposed under the substrate board  11 . The main circuit board  60  has a number of screw holes. For example, the main circuit board  60  has four screw holes  60   a  respectively disposed at the four corners of the main circuit board  60 . The substrate board  11  has a number of positioning holes  11   a  arranged in matrix form. The circuit board clamping mechanism  10  further includes a number of the bolts  60   b  and the nuts  60   c  respectively connecting the screw hole  60   a  and the positioning hole  11   a  for screwing the main circuit board  60  on the substrate board  11 , wherein the positioning hole  11   a  correspond to the screw hole  60   a . Normally, a number of transistors or electronic elements are disposed on the two side of the main circuit board  60 . By elevating the main circuit board  60  by a number of bolts  60   b  of the same height, the electronic elements disposed on the side near the substrate board  11  are prevented from colliding with the substrate board  11  directly. Furthermore, the substrate board  11  has a number of positioning holes  11   a  arranged in matrix form such that the main circuit board  60  can be of various sizes and the testing device  100  becomes more flexible in terms of usage.  
      Despite the connection between the main circuit board  60  and the substrate board  11  is exemplified by screwing the bolt  60   b  and the nut  60   c  in the present embodiment of the invention, the connection between the main circuit board  60  and the substrate board  11  can be achieved by ways of other lock joint, buckle joint, dowel joint, adhesive joint, cup joint, bolt joint or rivet joint.  
      The main circuit board  60  is coupled with the extending circuit board  70 . In the present embodiment of the invention, the extending circuit board  70  is vertically inserted into the slot of the main circuit board  60 , and there is a tilting angle θ of 90 degrees between the normal line N 60  of the main circuit board  60  and the normal line N 70  of the extending circuit board  70 .  
      The extending circuit board  70  is further firmly clamped on the substrate board  11  via a clamping element  13 . The clamping element  13  further includes a clamping part  13   a  and a fixing part  13   b . The clamping element  13  clamps one side of the extending circuit board  70  by the clamping part  13   a  and is fixed on the substrate board  11  by the fixing part  13   b . The clamping part  13   a  and the fixing part  13   b  form an L-shaped structure which can be integrally formed in one piece. The clamping element  13  further includes a spindle  13   c  disposed at the connection between the clamping part  13   a  and the fixing part  13   b . The fixing part  13   b  rotates around the spindle  13   c  and moves with respect to the clamping part  13   a . For example, the spindle  13   c  enables the clamping part  13   a  and the fixing part  13   b  to rotate relatively and is disposed on the substrate board  11 . The substrate board  11  has a number of positioning holes  11   a  arranged in matrix form. The fixing part  13   b  further has a bar-shaped fixing opening  13   d . When the fixing part  13   b  rotates around the spindle  13   c  and move with respect to the clamping part  11   a  until reaching a screwing position P, the fixing opening  13   d  corresponds to two positioning holes  1   a . The user may penetrate through the fixing opening  13   d  by two screws  13   e  to be screwed in the two positioning hole  11   a . The substrate board  11  having a number of positioning holes  11   a  and the fixing opening  13   d  and the spindle  13   c  enables the fixing part  13   b  to rotate and locate a suitable screwing position P to be fixed on the substrate board  11  when the clamping element  13  clamps the extending circuit board  70 . The clamping element  13  can be made from a hard material, such as copper, stainless steel or iron, for transmitting the vibrational force provided by the vibrational source to the extending circuit board  70 .  
      According to the above disclosure, after the testing platform  20  provides a vibrational source to a substrate board  11 , the substrate board  11  transmits the vibrational force to the extending circuit board  70  via the clamping element  13 , such that the vibrational force actually received by the extending circuit board  70  is close to the vibrational force predetermined. Thus, the sensing unit  30  of  FIG. 1  is capable of accurately measuring the electrical functions of the extending circuit board  70  under a vibrational state.  
      According to the above preferred embodiment, despite the clamping element is exemplified by being detachably disposed on the substrate board in the present embodiment of the invention, however, the clamping element can be integrally formed in one piece with the substrate board to be fixed on the substrate board in the present embodiment of the invention. Any designs capable of directly transmitting a vibrational force to the extending circuit board by a circuit board clamping mechanism such that the vibrational force is close to the vibrational force predetermined and the electrical functions of the extending circuit board are accurately measured are within the scope of technology of the invention.  
      A circuit board clamping mechanism and a testing device using the same are disclosed in above embodiment of the invention. The circuit board clamping mechanism positions the main circuit board by a substrate board and directly clamps the extending circuit board on the substrate board by a clamping element disposed on the substrate board, not only firmly clamping the main circuit board and the extending circuit board, but also accurately transmitting the vibrational force provided by the vibrational source to the extending circuit board. Therefore, the electrical functions of the extending circuit board and the main circuit board coupled together can be accurately measured and the quality of the electronic products can be assured.  
      While the invention has been described by way of example and in terms of a preferred embodiment, it is to be understood that the invention is not limited thereto. On the contrary, it is intended to cover various modifications and similar arrangements and procedures, and the scope of the appended claims therefore should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements and procedures.