Patent Publication Number: US-2011064362-A1

Title: Integrated circuit device or package and integrated circuit system, with an optical wave-guide element

Description:
BACKGROUND 
     1. Technical Field 
     The present disclosure relates to the field of integrated circuit devices or packages and integrated circuit systems. 
     2. Description of the Related Art 
     Currently, integrated circuit devices or packages are mounted on printing plates by means of wires or solder balls, which are used for electrical interconnections, in particular for data transmissions. 
     BRIEF SUMMARY 
     It is proposed an integrated circuit device, comprising a laminated substrate, at least an electro-optical element at least partially inserted in the laminated substrate, and at least an optical wave-guide element at least partially inserted in the laminated substrate and optically coupled to the electro-optical element. 
     The laminated substrate can comprise a cavity in which the electro-optical element and the optical wave-guide element are at least partially inserted. 
     The laminated substrate can include an electrical connection network connected to the electro-optical element. 
     The optical wave-guide element can include a fixing end part inserted in the laminate substrate and optically coupled to the electro-optical element and another end turned outside of the laminated substrate. 
     The laminated substrate can comprise a cavity in which the electro-optical element and a fixing end part of the optical wave-guide element are inserted. 
     The fixing end part of the optical wave-guide element can include a peripheral shoulder inserted in a passage of a core layer of the laminated substrate. 
     The laminated substrate can include at least a side layer placed above at least a side of the core layer. 
     The laminated substrate can include a core layer having at least a through-passage in which the electro-optical element and a shoulder of a fixing end part of the optical wave-guide element are inserted and side layers placed above the sides of the core layer and extended one above the electro-optical element and the other one above the shoulder of the optical wave-guide element. 
     An integrated circuit die can be located at the opposite side of the optical wave-guide element and connected to an electrical connection network. 
     A device can comprise an encapsulated means encapsulating the integrated circuit die and the connection means connecting the integrated circuit die and an electrical connection network. 
     It is also proposed an integrated circuit system, comprising an integrated circuit device, and comprising further a mounting plate on which the integrated circuit device is mounted by electrical connection means placed between the laminated substrate and the mounting plate, the mounting plate comprising at least an optical wave-guide part coupled to the optical wave-guide element. 
     It is also proposed an integrated circuit system, comprising an integrated circuit device according, and comprising further a mounting plate on which the integrated circuit device is mounted by electrical connection means placed between the laminated substrate and the mounting plate, the mounting plate carrying at least an optical wave-guide fiber having an end coupled to the optical wave-guide element. 
     The optical wave-guide fiber can extend through a crossing hole of the mounting plate. 
     The optical wave-guide fiber can be fixed to the mounting plate by means of at least a ring. 
     The optical wave-guide element can have an end part in said ring. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       Other advantages and features will become apparent by studying integrated circuit systems, described by way of non-limited examples and illustrated by the appended drawings in which: 
         FIG. 1  represents a cross section of an integrated circuit system; 
         FIG. 2  represents a cross section of another integrated circuit system; 
         FIG. 3  represents a cross section of an intermediate step of fabrication of an integrated circuit device of  FIG. 1 ; 
         FIG. 4  represents a cross section of another intermediate step of fabrication of an integrated circuit device of  FIG. 1 ; 
         FIG. 5  represents a cross section of another intermediate step of fabrication of an integrated circuit device of  FIG. 1 ; and 
         FIG. 6  represents a cross section of another intermediate step of fabrication of an integrated circuit device of  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIG. 1 , it can be seen that an integrated circuit system  1  is represented, comprising an integrated circuit device or package  2  and a connection mounting plate  3 . 
     The package  2  includes a laminated substrate  4  which comprises a dielectric core layer  5  having at least two through-passages  6  and  7  spaced apart from each other. 
     The package  2  includes an electro-optical element  8  such as an emitting diode and an electro-optical element  9  such as a receiving diode which are respectively inserted or integrated in the passages  6  and  7  in the same direction of the thickness of the core layer  5 . 
     The package  2  includes also an optical wave-guide element  10  optically coupled to the electro-optical element  8  and an optical wave-guide element  11  optically coupled to the electro-optical element  9 . The electro-optical elements  8  and  9  can be cylindrical and extend in the same direction of the thickness of the core layer  5 . 
     The optical wave-guide elements  10  and  11  comprise fixing end parts provided with peripheral shoulders  12  and  13  which are respectively inserted in the passages  6  and  7  of the core layer  5 . The other end parts of the optical wave-guide elements  10  and  11  are turned outside of the laminated substrate  4 . 
     The electro-optical element  8  and  9  and the fixing end parts of the optical wave-guide elements  10  and  11  are respectively stacked in the passages  6  and  7  in the same direction of the thickness of the core layer  5 , the fixing end parts of the optical wave-guide elements  10  and  11  having radial end faces  14  and  15  which are optically coupled respectively to the electro-optical elements  8  and  9 . 
     The laminated substrate  4  comprises further side dielectric build-up layers  16  and  17 . The build-up layer  16  is located above a side of the core layer  5  and extends over faces of the electro-optical elements  8  and  9  opposite to the optical wave-guide elements  10  and  11 . The build-up layer  17  is located above the other side of the core layer  5 , presents through-passages  18  and  19  for passing the optical wave-guide elements  10  and  11  and extends over the shoulders  12  and  13  of the last opposite to the optical wave-guide elements  10  and  11 . 
     The laminated substrate  4  of the package  2  includes a metal electrical connection network  20  which comprises a connection pattern  21  formed on the external face of the build-up layer  16 , a connection pattern  22  formed between the core layer  5  and the build-up layer  16 , a connection pattern  23  formed between the core layer  5  and the build-up layer  17 , and an external connection pattern  24  formed on the external face of the build-up layer  17 . 
     The electrical connection network  20  comprises further electrical vias  25  crossing the build-up layer  16  for connecting the connection pattern  21  and the connection pattern  22 , electrical vias  26  crossing passages  26   a  of the core layer  5  for connecting the connection pattern  22  and the connection pattern  23 , and electrical vias  27  crossing the build-up layer  17  for connecting the connection pattern  23  and the connection pattern  24 . 
     The electrical connection network  20  comprises further connection bumps or pillars  28  and  29  located around the shoulders  12  and  13  in the passages  6  and  7  of the core layer  5  for connecting the electro-optical elements  8  and  9  to the connection pattern  23 . 
     The thickness of, on one hand, the electro-optical elements  8  and the connection means  28  and the thickness of, on the other hand, the electro-optical elements  9  and the connection means  29  can be substantially equal to the thickness of the core layer  5 . 
     The package  2  includes further an integrated circuit die  30 , opposite to the optical wave-guide elements  10  and  11  and mounted by intermediate electrical connection balls  31  located between connection points of a face of the die  30  and the connection pattern  21 . 
     The package  2  can include also an encapsulating block  32  which encapsulates the die  30  and the connection balls  31  above the external face of the side layer  16 . 
     As an example, the package  2  can be manufactured according to the following steps. 
     Having a core layer plate, this plate is drilled for forming the passages  6  and  7  and the passages  26   a.    
     A first metal layer is formed on a face of the drilled plate. 
     Electro-optical elements  8  and  9  with connection bumps or pillars  28  and  29  are inserted and fixed in the passages  6  and  7  and on the first layer, the optical face of these elements  8  and  9  and the connection bumps or pillars  28  and  29  being opposite to the first layer. 
     The structure obtained at the end of the above step is illustrated on  FIG. 3 . 
     The passages  26   a  are filled with a metal for forming the vias  26  and a second metal layer is formed on the other face of the drilled plate. 
     The first and second metal layers are etching in order to form connection patterns  22  and  23  and to form passages in front of the optical part of the electro-optical elements  8  and  9 . 
     The structure obtained at the end of the above step is illustrated on  FIG. 4 . 
     The optical wave-guide elements  10  and  11  are installed, the shoulders  12  and  13  being inserted in the cavities. The radial end faces  14  and  15  of the optical wave-guide elements  10  and  11  are attached to the electro-optical elements  8  and  9  and or to the walls of the cavities by means of transparent glue. 
     The structure obtained at the end of the above step is illustrated on  FIG. 5 . 
     Having prepared a first side layer plate comprising a side layer  16 , a connection pattern  21  and vias  25  and a second side layer plate comprising a side layer  17 , a connection pattern  24  and vias  27 , these first and second side layer plates are linked to the corresponding faces of the core layer plate. 
     The structure obtained at the end of the above step is illustrated on  FIG. 6 . 
     After that, an integrated circuit die  30  is attached by means of connection solder balls  31  and an encapsulated block  32  is formed for example by molding. 
     At the end of the above step, the integrated circuit package  2  is realized. 
     As illustrated on  FIG. 1 , the integrated circuit package  2  as above described can be carried by the connection mounting plate  3  by the intermediate of electrical connection solder balls  33  located between the connection pattern  24  and a printed-circuit pattern  34  formed on a face  35  of the mounting plate  3 . 
     The mounting plate  3  includes further optical wave-guide parts  36  and  37  which are respectively optically coupled to the optical wave-guide elements  10  and  11 . The optical wave-guide parts  36  and  37  can have end faces  38  and  39  formed at the level of the face  35  of the mounting plate  3  and optically coupled to radial end faces  40  and  41  of the optical wave-guide elements  10  and  11  opposite to the faces  14  and  15  of these elements. 
     The dimensions of the connection balls  33  and the length of the optical wave-guide elements  10  and  11  are in correspondence so that the end faces  40  and  41  of the optical wave-guide elements  10  and  11  are placed close to or in contact on the end faces  38  and  39  of the optical wave-guide parts  36  and  37  of the mounting plate  3 . 
     It results from the above description the following advantages. 
     The core layer  5  gives the principle resistance of the substrate  4 . 
     The electro-optical elements  8  and  9  and the fixing end part of the optical wave-guide elements  10  and  11  having eventually the shoulders  12  and  13  are inserted or integrated in cavities of the laminated substrate  4  formed in the passages  6  and  7  of the core layer  5  and eventually between the side layers  16  and  17 . 
     Resulting from this integration, the electro-optical elements  8  and  9  and the optical wave-guide elements  10  and  11  are perfectly positioned. 
     The electrical connection network  20  can be used for selectively connecting the integrated circuit die  30  to the printed-circuit pattern  34  of the mounting plate  3  for connections to other components, and for connecting selectively the optical wave-guide elements  10  and  11  to the integrated circuit die  30  and eventually to the printed electrical connection pattern  34  of the mounting plate  3  for connections to other components. 
     The data having to be transferred between the integrated circuit die  30  and external components can be performed by using the optical links including the electro-optical elements  8  and  9 , the optical wave-guide elements  10  and  11  of the package  2  and the optical wave-guide parts  36  and  37  of the mounting plate  3 . So, high speed data transmissions can be performed. 
     The optical connections are insensitive to electromagnetic perturbances, contrarily to material connections. 
     Reductions of the sizes of the devices and systems can be obtained. 
     The cost of the complete devices and systems is reduced with respect to devices comprising discrete components. 
     Referring now to  FIG. 2 , as another example, it can be seen that an integrated circuit system  1   a  is represented, comprising the integrated circuit device or package  2 , corresponding to the above-described example, and a connection mounting plate  42 . 
     This mounting plate  42  differs from the mounting plate  3  in that the optical wave-guide parts  36  and  37  are replaced by optical fibers  43  and  44  which transverse crossing passages  45  and  46  of the mounting plate  42  and which are attached to the last by means of mounting rings  47  and  48 . 
     The end parts of the fibers  43  and  44  extend in prolongation of the optical wave-guide elements  10  and  11  and have radial end faces  49  and  50  optically coupled to the radial end faces  40  and  41  of these elements  10  and  11 . The end faces  40  and  41  can be close to or in contact with the end faces  49  and  50 . The end portions of the optical wave-guide elements  10  and  11  can extend in the rings  47  and  48 . 
     So, the data exchanges can be transferred by the fibers  43  and  44  to or from other components carried by the mounting plate  42  or provided in another place. 
     Although embodiments of the devices and systems of the present invention have been illustrated in the accompanying drawings and described in the foregoing detailed description, it will be understood that the disclosure is not limited to the embodiments disclosed, but is capable of numerous rearrangements, modifications and substitutions without departing from the spirit of the disclosure. 
     The various embodiments described above can be combined to provide further embodiments. These and other changes can be made to the embodiments in light of the above-detailed description. In general, in the following claims, the terms used should not be construed to limit the claims to the specific embodiments disclosed in the specification and the claims, but should be construed to include all possible embodiments along with the full scope of equivalents to which such claims are entitled. Accordingly, the claims are not limited by the disclosure.