Abstract:
Method for increasing the moisture-proof capability of a chip includes coating moisture-proof glue at the chink of the chip. More particularly, when the packaging structure carries a chink exposed to outside of the chip, the chink is coated with the moisture-proof glue for preventing moisture from entering the internal part of the chip so as to increase the moisture-proof capability of the chip.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to a moisture-proof technology, and more particularly, to a moisture-proof technology for an Integrated Chip (IC). 
         [0003]    2. Description of the Prior Art 
         [0004]    Please refer to  FIG. 1 .  FIG. 1  is a diagram illustrating a conventional IC  100 . The IC  100  is packaged by Ball Grid Array (BGA). The IC  100  comprises a first packaging body  110 , a second packaging body  120 , and a die  130 . The first packaging body  110  is utilized as a molding compound, which protects the die  130 ; the second packaging body  120  is utilized as a substrate, and the bottom surface of the second packaging body  120  is planted with solder balls, so that the IC  100  is capable of connecting to a Print Circuit Board (PCB) through the solder balls. In this way, the die  130  can communicate with circuitry of the PCB through the second packaging body  120  and the solder balls B. Furthermore, the second packaging body  120  carries the die  130 . 
         [0005]    The material of the first packaging body  110  can be, e.g. epoxy; the material of the second packaging body  120  can be, e.g. Flame retardant 4 (FR-4). Since the first and the second packaging bodies  110  and  120  are made of different materials, an interface  140  exists between the first and the second packaging bodies  110  and  120  after the first and the second packaging bodies  110  and  120  are combined by the packaging process. Chinks possibly exist at the interface  140  in such structure, which allows moisture to enter the IC  100 . In this way, the lifetime and the reliability of the IC  100  are reduced, causing great inconvenience. 
       SUMMARY OF THE INVENTION 
       [0006]    The present invention provides a moisture-proof device for an Integrated Chip (IC) for increasing moisture-proof capability of the IC. The IC has a first and a second packaging bodies. The moisture-proof device comprises a moisture-proof glue, applied to the first and the second packaging bodies for increasing the moisture-proof capability of the IC. 
         [0007]    The present invention further provides a moisture-proof IC. The moisture-proof IC comprises a die; a first packaging body on the die; a second packaging body below the die; and a moisture-proof device, comprising a moisture-proof glue, applied to the first and the second packaging bodies for increasing the moisture-proof capability of the IC. 
         [0008]    The present invention further provides a method for increasing moisture-proof capability of an IC. The method comprises applying moisture-proof glue to periphery of the IC. 
         [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 that is illustrated in the various figures and drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]      FIG. 1  is a diagram illustrating a conventional IC. 
           [0011]      FIG. 2  is a diagram illustrating a moisture-proof IC according to a first embodiment of the present invention. 
           [0012]      FIGS. 3 ,  4 , and  5  are diagrams illustrating top view, bottom view, and 3-D view of the moisture-proof IC of the first embodiment of the present invention. 
           [0013]      FIG. 6  is a diagram illustrating a moisture-proof IC according to a second embodiment of the present invention. 
           [0014]      FIGS. 7 ,  8 , and  9  are diagrams illustrating top view, bottom view, and 3-D view of the moisture-proof IC of the second embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0015]    Please refer to  FIG. 2 .  FIG. 2  is a diagram illustrating a moisture-proof IC  200  according to a first embodiment of the present invention. In  FIG. 2 , the present invention coats moisture-proof glue  210  externally onto the IC  200  for moisture-proof functioning. More particularly, the moisture-proof glue  210  is coated around the periphery of the IC  200 . The material of the moisture-proof glue  210  can be, e.g. silicone in solvent, or epoxy. As shown in  FIG. 2 , the chinks between the first and the second packaging bodies  110  and  120  are covered by the moisture-proof glue  210 . It can be clearly seen from  FIG. 2  that an interface is formed at the sides of the first and the second packaging bodies  110  and  120 , and the moisture-proof glue  120  is applied onto the interface. In this way, moisture cannot enter the IC  200  through the chinks between the first and the second packaging bodies  110  and  120  and cannot damage the IC  200 , which increases the lifetime and the reliability of the IC  200 . 
         [0016]    Please refer to  FIGS. 3 ,  4 , and  5 .  FIGS. 3 ,  4 , and  5  are diagrams illustrating top view, bottom view, and 3-D view of the moisture-proof IC  200  of the first embodiment of the present invention. As shown in  FIGS. 3 ,  4 , and  5 , it can be seen that the moisture-proof glue  210  are applied at the periphery of the IC  200  for moisture-proof. Besides, the cross section cut by the broken line A-A′ in  FIG. 5  is  FIG. 2 . 
         [0017]    Please refer to  FIG. 6 .  FIG. 6  is a diagram illustrating a moisture-proof IC  600  according to a second embodiment of the present invention. In  FIG. 6 , the present invention coats moisture-proof glue  610  externally onto the IC  600  for moisture-proof functioning. More particularly, the moisture-proof glue  610  is coated around the periphery, the top surface, and the bottom surface of the IC  600 . The material of the moisture-proof glue  610  can be, e.g. silicone in solvent, or epoxy. As shown in  FIG. 2 , the chinks between the first and the second packaging bodies  110  and  120  are covered by the moisture-proof glue  610 , and furthermore, the moisture-proof glue  610  extends to the top surface of the first packaging body  110  and the bottom surface of the second packaging body  120  for increasing the capability of moisture-proof more. Besides, it is noticeable that since the bottom surface of the second packaging body  120  is utilized for planting solder balls B, therefore when the present invention applies the moisture-proof glue  610  to the bottom surface of the second packaging body  120 , the present invention avoids applying the moisture-proof glue  610  to the solder balls B so as to prevent the IC  200  from being unable to connect to the PCB. In other words, the bottom surface of the second packaging body  120  comprises solder-ball-planting area and non-solder-ball-planting area, and the solder-ball-planting area is utilized for planting solder balls. Thus the moisture-proof glue  610  is only applied to the non-solder-ball-planting area of the bottom surface of the second packaging body. 
         [0018]    Please refer to  FIGS. 7 ,  8 , and  9 .  FIGS. 7 ,  8 , and  9  are diagrams illustrating top view, bottom view, and 3-D view of the moisture-proof IC  600  of the second embodiment of the present invention. As shown in  FIGS. 7 ,  8 , and  9 , it can be seen that the moisture-proof glue  210  are applied at the periphery, the top surface, and the bottom surface of the IC  200  for moisture-proof. Besides, the cross section cut by the broken line A-A′ in  FIG. 9  is  FIG. 6 . 
         [0019]    Additionally, the materials of the first and the second packaging bodies described in the present invention do not have to be different. That is, the first and the second packaging bodies are determined by the existence of the interface. In other words, even the first and the second packaging bodies are made of the same material, as long as an interface exist, the first and the second packaging bodies are still determined to be different by the present invention. 
         [0020]    From the above-mentioned description, it is known that the spirit of the present invention is to apply moisture-proof glue to ICs having interfaces exposed externally for isolating moisture from internal parts of ICs, which avoids conductivities of dies, wires being deteriorated, or the reliability being reduced. The areas the moisture-proof glue mainly applied are the interfaces, of the IC, exposed externally, which are possibly chinks. Moreover, the moisture-proof glue can be applied widely to other areas such as the top surface or the bottom surface of the IC while some particular area, e.g. the area the IC connecting to the external circuitry, has to be avoided to be applied, in order not to cause bad connections. In this way, the moisture-proof capability of IC can be improved. Therefore, the present invention can be applied to any packaging structures having chinks but not limited to BGA packaging structure. 
         [0021]    To sum up, by the moisture-proof technology provided by the present invention, moisture is effectively isolated from the internal part of the IC, which increases the moisture-proof capability of the IC, providing great convenience. 
         [0022]    Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention.