Patent Publication Number: US-2003226252-A1

Title: Packaging method for X-ray image sensory systems

Description:
BACKGROUND OF THE INVENTION  
       [0001] 1. Field of the Invention  
       [0002] The present invention relates to a packaging method for X-ray image sensory systems, and more particularly, to a packaging method for connecting separately manufactured components of an X-ray sensory system.  
       [0003] 2. Description of Prior Arts  
       [0004] An X-ray image sensory system converts the input X-rays into electrical or visible light signals. The converted signals are then collected separately to obtain the mapping of the X-ray dosage. A TFT panel is then used for outputting the obtained mapping. As described in the previous operation, the TFT panel is not used in converting X-rays to electrical or visible light signals.  
       [0005] The conventional process for manufacturing X-ray image sensory systems is to manufacture the TFT panel first. As the TFT panel is ready, the diodes, X-ray conversion layers or scintillators are then manufactured on top of the panels. There is a severe problem with this type of serial manufacturing process. During the manufacturing process, mistakes in any step will render the entire product useless. This may cause very low yields and high production costs.  
       [0006] In general, the TFT panels are manufactured at the temperature below 350 degrees Celsius. If the required working temperature for manufacturing steps for other components exceed the tolerance temperature of panel, the panels may suffer permanent damages. Furthermore, the metal layer on the TFT panels for growing diodes can be easily damaged by the chemicals used in the successive steps. Because the entire manufacturing process of an X-ray image sensory system is with many risks of damages, the manufacturing yields are consequently low, thus unit production cost is high. To improve the low yield situation, the present manufacturing process for X-ray image sensory systems usually follows very strict guidelines, which, in turn, place severe constraints on selections of the material and application methods for successive steps.  
       SUMMARY OF THE INVENTION  
       [0007] The present invention is to provide a packaging method for X-ray image sensory systems. The packaging method allows each component of the X-ray image sensory systems to be manufactured separately. For example, the X-ray conversion module and the TFT panels can be manufactured separately. A pixel-based connecting method is then applied to connect the aforementioned conversion module and the TFT panel. The pixel-based connecting method employs electrically conductive bumps or boundary frames to connect the TFT panel and the conversion module on a pixel basis. The signals converted by the conversion module can then be transmitted through the conductive bumps to the TFT panels.  
       [0008] For the aforementioned purpose, the present invention provides a packaging method for the X-ray image sensory systems. The X-ray image sensory system includes one or more x ray conversion modules for converting the input X-ray into electrical or visible light signals, and a TFT panel for collecting and outputting the signals. The X-ray conversion modules and the TFT panels are manufactured separately, thereafter are electrically connected by the conductive bumps or boundary frames for electrical or visible light transmission.  
       [0009] These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment which is illustrated in the various figures and drawings. 
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0010]FIG. 1A is a schematic diagram of the first embodiment of the present invention.  
     [0011]FIG. 1B is a schematic diagram of another embodiment of the present invention.  
     [0012]FIG. 1C is a schematic diagram of another embodiment of the present invention.  
     [0013]FIG. 2A is a schematic diagram of another embodiment of the present invention.  
     [0014]FIG. 2B is a schematic diagram illustrating the embodiment of FIG. 2A after connection.  
     [0015]FIG. 3A is a schematic diagram of another embodiment of the present invention.  
     [0016]FIG. 3B is a schematic diagram illustrating the embodiment of FIG. 3A after connection.  
     [0017]FIG. 4A is a schematic diagram of another embodiment of the present invention.  
     [0018]FIG. 4B is a embodiment of FIG. 4A after connection. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
     [0019]FIG. 1A shows a schematic diagram of a preferred embodiment  10  according to the present invention. The embodiment  10  includes an X-ray conversion module  12  for converting the input x ray (not shown), and a TFT panel  14  for collecting and outputting the converted signals. The X-ray conversion module  12  and the TFT panel  14  are manufactured separately. The X-ray conversion module  12  includes at least one conductive bump  16 , each of which corresponds to one pixel. The X-ray conversion module  12  and the TFT panel  14  utilize the conductive bumps  16  for connection. The electrical signals, converted from the input X-ray by the conversion module  12 , can travel through the conductive bumps  16 , and be collected and outputted by the TFT panel  14 . Because the size and the distribution of the conductive bumps  16  depend on those of the pixels on the TFT panels  14 , the packaged X-ray image sensory system, including an X-ray conversion module  12  and a TFT panel  14 , can output the pixelized signals.  
     [0020]FIG. 1B shows a schematic diagram of another embodiment  20  of the present invention. The embodiment  20  also includes an X-ray conversion module  22  for converting the input X-ray (not shown), and a TFT panel  24  for collecting and outputting the converted signals. The X-ray conversion module  22  and the TFT panel  24  are also manufactured separately. The embodiment differs from the one depicted in FIG. 1A in that the conductive bumps  26  are placed on the TFT panels  24 . Each conductive bump  26  corresponds to a pixel. The conversion module  22  is connected to the TFT panel  24  through the conductive bumps  26 . The electrical signal, converted from the input X-ray by the X-ray conversion module  22 , can travel through the conductive bumps  26 , and be collected and outputted by the TFT panel  24 . Because the size and the distribution of the conductive bumps  26  depend on those of the pixels on the TFT panels  24 , the packaged X-ray image sensory system, including an X-ray conversion module  22  and a TFT panel  24 , can output the pixelized signals.  
     [0021]FIG. 1C shows a schematic diagram of another embodiment  30  of the present invention. The embodiment  30  also includes an X-ray conversion module  32  for converting the input X-ray and a TFT panel  34  for collecting and outputting the converted signals. The X-ray conversion module  32  and the TFT panel  34  are also manufactured separately. The embodiment  30  differs from its counterpart  10  and  20  shown in FIGS. 1A and 1B in that the conductive bumps  36  and  37  are placed on both the conversion module  32  and the TFT panels  34 . Each conductive bump  36  corresponds to another conductive bump  37 , which, in turn, corresponds to a pixel. Because the size and the distribution of the conductive bumps  36  depend on those of the bumps  37  on the TFT panels  24 , which, in turn, depend on the pixels on the TFT panels  24 , the packaged X-ray image sensory system  30 , including an X-ray conversion module  32  and a TFT panel  34 , can output the pixelized signals.  
     [0022] The conductive bumps  16 , 26 , 36  and  37  in the FIGS. 1A, 1B, and  1 C, and their conversion modules  12 ,  22 ,  32 , and the TFT panels  14 ,  24 ,  34  could be glued together by a conductive glue, or using pressure or heat for attachment.  
     [0023]FIGS. 2A and 2B show schematic diagrams illustrating another preferred embodiment  40  of the present invention before and after connection. The embodiment  40  includes an X-ray conversion module  42  for converting the input X-ray and a TFT panel  44  for collecting and outputting the converted signals. The X-ray conversion module  42  and the TFT panel  44  are manufactured separately. The X-ray conversion module  42  includes a boundary frame  46  for connecting to the TFT panel  44 . After the connection, there is a gap  47  between the conversion module  42  and the TFT panel  44 , as shown in FIG. 2B. The present invention includes a step of placing a supporter  48  in the gap  47 , so that the TFT panel  44  can firmly support the conversion module  42 . The supporter  48  could be a glass ball or a fiber rod. In addition to the supporter  48 , a sealing glue  49  is applied to connect the boundary frame  46  to the TFT panel  44 , as well as connecting the conversion module  42  to the TFT panel  44 . The present invention also includes a step of allowing the gap  47  to be a vacuum gap after sealing the boundary frame  46  with the glue  49 . The vacuum gap  47  is necessary for the field emission at the X-ray conversion module  42 . The height of the supporter  48  should be approximately the same as that of the boundary frame  46  for the purpose of ensuring a tight connection between the conversion module  42  and the TFT panel  44 , and, thus to keep the gap  47  be vacuum.  
     [0024]FIGS. 3A and 3B show schematic diagrams of illustrating another embodiment  50  of the present invention before and after connection. The embodiment  50  includes an X-ray conversion module  52  for converting the input X-ray and a TFT panel  54  for collecting and outputting the converted signals. The X-ray conversion module  52  and the TFT panel  54  are manufactured separately. The TFT panel  54  includes a boundary frame  56  for connecting to the conversion module  54 . After the connection, there is a gap  57  between the conversion module  52  and the TFT panel  54 , as shown as in FIG. 3B. The present packaging method further includes a step of placing at least one supporter  58  in the gap  57 , so that the TFT panel  54  can firmly support the conversion module  52 . The supporter  58  could be a glass ball or a fiber rod. In addition to the supporter  58 , a sealing glue  59  is applied to connect the boundary frame  56  to the conversion module  52 , as well as connect the TFT panel  54  to the conversion module  52 . The present invention also includes a step of enabling the gap  57  to be a vacuum gap after sealing the boundary frame  56  with the glue  59 . The vacuum gap  57  is necessary for the field emission at the X-ray conversion module  52 . The height of the supporter  58  should be approximately the same as that of the boundary frame  56 . This is to ensure the tight connection between the conversion module  52  and the TFT panel  54 , and keep the gap  57  in the vacuum state.  
     [0025]FIGS. 4A and 4B show schematic diagrams of another embodiment  60  of the present invention before and after connection. The embodiment  60  includes an X-ray conversion module  62  for converting the input X-ray and a TFT panel  64  for collecting and outputting the converted signals. The X-ray conversion module  62  and the TFT panel  64  are manufactured separately. The X-ray conversion module  62  and the TFT panel  64  include a boundary frame  65  and  66 , respectively. The boundary frame  65  and  66  are then connected together. After the connection, there is a gap  67  between the conversion module  62  and the TFT panel  64 , as shown in FIG. 4B. The present embodiment is formed by another step of placing a supporter  68  in the gap  67 , so that the TFT panel  64  can firmly support the conversion module  62 . The supporter  68  could be a glass ball or a fiber rod. In addition to the supporter  68 , a sealing glue  69  is applied to connect the boundary frame  66  to the X-ray conversion module  62 , as well as connect the TFT panel  64  to the X-ray conversion module  62 . The present invention also includes another step of forming a vacuum gap  67  between the X-ray conversion module  62  and the TFT panel  64  after sealing the boundary frame  66  with the sealing glue  69 . The vacuum gap  67  is necessary for the field emission at the X-ray conversion module  62 . Further, the height of the supporter  68  should be approximately the same as that of the boundary frame  66 , for ensuring a tight connection between the conversion module  62  and the TFT panel  64 , and maintaining the gap  67  to be vacuum.  
     [0026] The boundary frames  46 ,  56 ,  65  and  66  could be placed on the opposing sides or all sides around the X-ray conversion modules  42 ,  52 ,  62  and the TFT panels  44 ,  54 ,  64 . This kind of placement is to ensure the tight connection between the conversion modules  42 ,  52 ,  62  and the TFT panels  44 ,  54 ,  64 .  
     [0027] The X-ray conversion modules  12 ,  22 ,  32 ,  42 ,  52 , and  62  could either convert the input X-rays into the visible light signals first or into electrical signals directly. The visible light signals could be detected by a photodiode, thereby generating corresponding electrical signals. This is the so-called in-direct conversion. Alternatively, the input X-ray could be directly converted to electrical signals. Regardless of the conversion type, the guiding rule is to ensure that the converted signals could be completely collected and outputted by the TFT panels  14 ,  24 ,  34 ,  44 ,  54 , and  64 .  
     [0028] Compared to the prior arts, the present invention allows separately manufacturing the components of the X-ray image sensory systems and assembling them together for the purpose of improving the yield of the product. Further, the present invention is a pixel-based connecting method while connecting the aforementioned conversion module and the TFT panel. The pixel-based connecting method employs electrically conductive bumps or boundary frames to connect the pixels of the TFT panel and the conversion module. In the case of boundary frames, the present invention also includes steps of applying a sealing glue between the conversion module and TFT panel, and keeping the gap between the conversion module and the TFT panel be vacuum, thereby necessitating the field emission of the conversion module. Because the present invention allows the components to be manufactured separately, the manufacturing of one component will not affect others. Therefore, the choice of materials and process in manufacturing each individual component is more flexible. Furthermore, as the components are manufactured separately, one damaged component due to manufacturing mistakes will not affect other components, thus, the damaged component is replaceable and the yield of whole image sensory system can be improved to lower the production cost.  
     [0029] Those skilled in the art will readily observe that numerous modifications and alterations of the device may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.