Abstract:
A supporting frame is used to solidly bridge to the two metallic contacts of a surface mount diode chip. Any bending or twisting stress between the two contacts is borne by the supporting frame instead of the diode chip. Otherwise the stress may damage the diode chip.

Description:
This application is a continuation of Ser. No. 09/712,664, filed Nov. 15, 2000, now abandoned. 

   BACKGROUND OF THE INVENTION 
   (1) Field of the Invention 
   This invention relates to semiconductor device package, particularly a surface-mount diode package. 
   (2) Brief Description of the Related Art 
     FIG. 1  shows a prior art diode package. A semiconductor diode chip  10  has two bottom electrodes  101  and  102  at two ends of the chip as shown in  FIG. 2 , which is section view of  FIG. 1  along the dotted section line. The electrodes  101  and  102  are attached respectively to two metallic contacts  11  and  12  by means of solder  14 . These two metallic base contacts serve as leads for surface mounting of the diode package on a mother board. The chip  10  is then covered and sealed in a glue  13 . 
   Since the chip is supported on the two metallic base plates  11  and  12 , any relative bending and twisting of the two metallic contacts may cause damage to the chip  10 . 
   SUMMARY OF THE INVENTION 
   An object of this invention is to strengthen the support of a diode chip in a surface-mount package. Another object of this invention is to improve the reliability of a diode package. 
   These objects are achieved by adding a supporting frame bridging the two metallic contacts. Thus any bending or twisting stress exerted between the two contacts is mainly borne by the supporting frame instead of the chip, and the supporting frame is strong enough to withstand any such bending and/or twisting stress. 

   
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       FIG. 1  shows a prior art diode package. 
       FIG. 2  shows a cross section view of  FIG. 1   
       FIG. 3  shows the base structure of the present invention with a supporting frame around the diode chip. 
       FIG. 4  shows the cross section view of the  FIG. 3 . 
       FIG. 5  shows a second embodiment of the present invention. 
       FIG. 6  shows the cross section view of  FIG. 5 . 
       FIG. 7  shows a third embodiment of the present invention. 
       FIG. 8  shows the cross section view of  FIG. 7 . 
       FIG. 9  shows a fourth embodiment of the present invention. 
       FIG. 10  shows the 3-dimensional view of the supporting frame in of  FIG. 9 . 
       FIG. 11  shows a unitary structure of the supporting frame with one of the contacts. 
       FIG. 12  shows a unitary structure of the supporting frame for the embodiment shown in  FIG. 6 . 
       FIG. 13  shows a unitary structure of the supporting frame for the embodiment shown in  FIG. 8 . 
       FIG. 14  shows a conical hole in the supporting frame shown in  FIG. 13   
   

   DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 3  shows the basic structure of the present invention. A diode chip  10  is mounted over two metallic contacts  21 , 22 , serving as leads of a surface mounting diode package. the diode chip  10  is surrounded by a metal frame  25 , which is also mounted over the two metallic contacts  21 ,  22  by solders  24 . 
     FIG. 4  shows the cross section view of  FIG. 3  along the dotted section line The diode chip has two bottom electrodes  101  and  102 , which are connected to the metallic contacts  21  and  22 , respectively by means of the solder  14 . The supporting frame  25  is also mounted over the two supporting metallic frame  25  by means of solders  24 . Because the supporting frame  25  is larger than the diode chip  10  and surrounds the diode chip, any bending or twisting stress exerted between the two metallic contacts  21 ,  22  is withstood by the supporting frame  25  instead of the diode chip. Thus, the diode chip is protected by the supporting frame  25 . 
     FIG. 5  shows a second embodiment of the present invention. The diode chip  20  has two top electrodes  201 ,  202 . The diode chip  20  is surrounded by a supporting frame  25  which is attached to two metal contacts  31  and  32 , serving as leads for surface mounted to a mother board. The electrodes  201  and  202  are connected to the two metal contacts  31  and  32  respectively by means by solders  14  as shown in  FIG. 6  at points  301  and  302 , which is a cross section view of  FIG. 5  along the dotted section line. The supporting frame  25  cups the diode chip  20  and is hanging under the two zigzag metallic contacts  31 ,  32  by means of solders  24 . Since the supporting frame  25  bridges between the two metallic contacts  31 ,  32 , the supporting frame  25  prevents any bending or twisting between the two metallic contacts  31 ,  32 . As the diode chip  20  is soldered under the zigzag metallic contacts  31 ,  32 , the supporting frame  25  prevents any bending or twisting stress exerted to the diode. 
     FIG. 7  shows a third embodiment of the present invention for packaging a diode chip  30  with a single top electrode  301  and a bottom electrode. The diode chip  30  is surrounded by a supporting frame  25 . The top electrode  301  is connected to a metallic contact  41  through a lead  401  for surface mounting. The bottom electrode of the diode chip is connected to another metallic contact  42  for surface mounting.  FIG. 8  shows the cross section view  FIG. 7  along the dotted line. The top electrode  301  of the diode chip  30  is connected to the lead  401  of a zigzag metallic plate  41  by means of the solder  14 . The bottom electrode  302  of the diode chip  30  is connected to the metallic contact  42  by means of the glue  24 , which is between the metallic contact  41  and the supporting frame  25 . The supporting frame  25  is also mounted over the metallic contact  42  by means of glue  24 . The supporting frame  25  prevents bending or twisting stress exerted to the diode. 
     FIG. 9  shows a fourth embodiment of the present invention for packaging a diode chip with two top electrodes  201  and  202 . The diode chip is surrounded by a supporting frame  35 . The top electrode  201  is connected to a zigzag metallic contact  31  for surface mounting through glue  14 . The top electrode  202  is connected to a zigzag metallic contact for surface mounting through another solder  14 . The supporting frame  35  is also attached to the metallic contact  31  by means of glue  24  and to the metallic contact  32  by means of another glue  24 . The supporting frame  35  bridges across the two metallic contacts  31  and  32  and prevents any bending or twisting stress exerted on the diode chip  20 . The shape of the supporting frame  35  is shown in  FIG. 10  showing a conical window to anchor the diode chip. 
     FIG. 11  shows a fifth embodiment of the present invention. A supporting frame  55  is formed over a metallic contact  51  as a cantilever in a unitary structure. The end of the cantilever is glued (not shown) to the second metallic contact such that the supporting frame  55  is solidly fixed with respect to the two metallic contacts  51 ,  52 . Thus the supporting frame  55  bridges across the two metallic contacts  51 ,  52  and prevents any bending or twisting stress exerted on the diode chip anchored inside the supporting frame  55 . 
     FIG. 12  shows a sixth embodiment of the present invention. The metallic contacts  61  and  62  are of zigzag shape. The supporting frame  65  is hanging under the metallic contact  61 . The free end of the cantilever is glued under the second metallic contact  62 . Thus the supporting frame  65  is solidly fixed with respect to the two metallic contacts  61 ,  62  and prevents any bending or twisting stress exerted on the diode chip anchored inside the supporting frame  65 . 
     FIG. 13  shows a seventh embodiment of the present invention. The supporting frame  75  is formed as a pedestal to the left of the metallic contact  72 . The left end of the supporting frame  75  is glued under a zigzag metallic contact  71 . Thus the supporting frame  75  is solidly fixed with respect to the two metallic contacts  71 ,  72  and prevents any bending or twisting stress exerted on the diode chip anchored inside a circular window of the supporting frame  75 . 
     FIG. 14  shows an eighth embodiment of the present invention. The structure is similar to that in shown in  FIG. 13 , except that the window of the supporting frame  85  is of conical shape. As in  FIG. 13 , the supporting frame forms a pedestal over the metallic contact  82  and is glued on top to another metallic contact  81 . 
   While the preferred embodiments of the invention have been described, it will be apparent to those skilled in the art that various modifications may be made in the embodiments without departing from the spirit of the present invention. Such modifications are all within the scope of this invention.