Abstract:
This programmable multi-chip module (PMCM) substrate consists of an array of apparatus slots for bare-die attachment and Field Programmable Interconnect Chips (FPICs) for multi-chip module (MCM) substrate routing. The present invention relates to a slot apparatus on a PMCM, which allows the bare-dies flexible attached on the slot apparatus. The slot apparatus of the present invention includes a plurality of first-slot-modules for accommodating and connecting at least one bare-die. Therefore, the PMCM assembled by the slots of the present invention provides a fast-built, error-detecting, and general-purpose substrate.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention relates to a slot apparatus, which allows the bare-dies to be attached on the slot apparatuses for a programmable multi-chip module or a high-density multi-layer printed circuit board.  
           [0003]    2. Description of the Related Arts  
           [0004]    Portable systems design and add-on cards have stringent limits on low-power and small-size constraints. A Multi-Chip Module (MCM) is a device in which several bare-dies are attached to a single substrate and then packaged as a small-size and low-power system. Furthermore, MCM packaging technology used in electronic systems translate the semiconductor speed into system performance, but low-power and high-density MCMs are expensive to fabricate and usually require weeks of engineering effort for system prototyping and product verification. The engineering delay in designing and fabricating such MCMs become unacceptable in today&#39;s competitive market. The needs of quick turnaround time, high product yield, and low cost have led to the development of another approach, called Programmable Multi-Chip Module (PMCM).  
           [0005]    This PMCM technology provides the designers with a pre-characterized MCM substrate and some programmable interconnections such that they can generate a fast prototyping or a final consumer product in a short time. The advantages of PMCM are that the field programmable technology can reduce product development cycle and NRE (Non-Recurrence Engineering) cost, while MCM technology can achieve low power and small size.  
           [0006]    This PMCM substrate consists of an array of slot apparatuses for bare-dies attachment and Field Programmable Interconnect Chips (FPICs) for MCM substrate routing. Each bare-die pad is connected via a metal wire to a pad of the FPIC, and net routing is accomplished by programming the FPICs. Aptix and I-Cube are both well-known FPIC manufacturers.  
           [0007]    [0007]FIG. 1 illustrates a programmable multi-chip module (PMCM)  10  according to the prior art. The PMCM  10  includes a substrate  12 , a plurality of slot apparatuses  14  disposed on the substrate  12 , and a plurality of bare-dies  16  attached on slot apparatuses  14 . A plurality of pads  18  of PMCM  10  is disposed around the near-edge area of the substrate  12 . A plurality of FPICs  20  is disposed on the substrate  12  and is located around the corresponding slot apparatuses  14  to interconnect the plurality of pads on the slot apparatuses  14  and the plurality of pads  18  on the PMCM. Each of the bare-die  16  is attached on one slot  14  using the wire bonding technology and is connected to one pad (not shown) on the slot apparatus  14 . Each pad of slot apparatuses  14  is connected via a metal wire to one of the FPIC pads  20 .  
           [0008]    According to the prior art, each slot  14  on the PMCM  10  only accommodates one single bare-die  16 . The number of bare-dies  16  disposed on the PMCM  10  is the same as the number of slot apparatuses  14  available. That is, the PMCM  10  of the prior art does not allow a flexible arrangement of the bare-dies  16 . Furthermore, once the slot  14  is designed, the number of pads of a bare-die attached on the slot is limited by constraint. It is not feasible to apply the PMCM  10  of the prior art when a plurality of bare-dies  16  with different sizes and with different pad numbers is to be disposed on the PMCM  10 .  
         SUMMARY OF THE INVENTION  
         [0009]    To solve the aforementioned problems, the present invention discloses a slot apparatus on a PMCM. The purpose of these flexible slot apparatuses is aimed at attaching bare-dies  16  with different sizes and with different pad numbers on a PMCM  10  in different combinations. The slot apparatus of the present invention includes a plurality of the first-slot-modules to attach to at least one bare-die. Each slot pad is connected via a substrate metal wire to one of the FPIC pads, and the net routing is accomplished by programming the FPICs.  
           [0010]    According to the present invention, a PMCM substrate with the slot apparatuses can provide a fast-built and low-cost prototyping system. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]    [0011]FIG. 1 illustrates a PMCM according to the prior art.  
         [0012]    [0012]FIG. 2 illustrates a PMCM utilizing the slots of the present invention.  
         [0013]    [0013]FIG. 3 illustrates a slot apparatus according to the present invention.  
         [0014]    [0014]FIG. 4 illustrates the first embodiment of the arrangement of bare-dies attached on the slot apparatus as shown in FIG. 3.  
         [0015]    [0015]FIG. 5 illustrates the second embodiment of the arrangement of a bare-die attached on the slot apparatus as shown in FIG. 3.  
         [0016]    [0016]FIG. 6 illustrates another embodiment of the slot apparatus according to the present invention.  
         [0017]    [0017]FIG. 7 illustrates the first embodiment of the arrangement of bare-dies attached on the slot apparatus as shown in FIG. 6.  
         [0018]    [0018]FIG. 8 illustrates the second embodiment of the arrangement of bare-dies attached on the slot apparatus as shown in FIG. 6.  
         [0019]    [0019]FIG. 9 illustrates the third embodiment of the arrangement of bare-dies attached on the slot apparatus as shown in FIG. 6. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0020]    [0020]FIG. 2 illustrates the PMCM  30  containing the slot apparatuses  34  of the present invention. The present invention provides slot apparatuses  34  with a plurality of bare-dies  36  attachments on a PMCM  30 . The PMCM  30  includes a substrate  32 , a plurality of slots  34 , a plurality of pads  38  of the PMCM, and a plurality of FPICs  40 .  
         [0021]    The slots  34  allow bare-dies  36  with different pad numbers to attach on the MCM substrate  32 . The pads  38  of PMCM are residing around the near-edge area of the MCM substrate  32 . The FPICs  40  are attached on the substrate  32  and are located around the slots  34  for interconnecting the pads of slots  34  and the external pads  38 .  
         [0022]    Please refer to FIG. 3 and FIG. 4. FIG. 3 illustrates the slot apparatus  34  according to the present invention, and FIG. 4 illustrates the first embodiment of the arrangement of bare-dies  36  attached on the slot apparatus  34 . The slot apparatus  34  of present invention includes four first-slot-modules  42  on the MCM substrate  32 , and a bare-die  36  can be attached on the first-slot-modules  42 . Each of the first-slot-modules  42  includes a plurality of internal pads  44  for bare-die attachment. In each of the first-slot-modules  42 , each pair of pads  44  in the A 1 -A 2  direction (or pads  44  in the B 1 -B 2  direction orthogonal to the A 1 -A 2  direction) is connected together through metal wiring  46 . The slot apparatus  34  of the present invention includes a plurality of external pads  48 ; each external pad  48  is connected to a pair of the internal pads  44  in the A 1 -A 2  direction (or pads  44  in the B 1 -B 2  direction orthogonal to the A 1 -A 2  direction). The external pads  48  of a slot apparatus  34  are connect to the pads of FPICs  20  through metal wiring  46 .  
         [0023]    Please refer to FIG. 4. Four bare-dies  36  are attached on the slot apparatus  34 , and each bare-die  36  includes a plurality of pads  50 . The pads  50  of each bare-die  36  are connected to the internal pads  44  of the first-slot-module  42  by using the wire-bonding technology. Each pad  48  of slot apparatus  34  is connected via metal wires to one of the FPIC  20  pads, and the net routing between the pads of slot apparatuses  34  and the pads  38  is accomplished by programming the FPICs  20 .  
         [0024]    Please refer to FIG. 5. FIG. 5 illustrates the second embodiment of a large bare-die  37  attached on the slot apparatus  34  (as shown in FIG. 3). The bare-die  37  includes a plurality of pads  50 ; the pads  50  of the bare-die  37  are connected to the internal pads  44  of the first-slot-module  42  by using the wire-bonding technology. According to FIG. 5, the large bare-die  37  occupies all the four first-slot-modules  42 . Each pad  48  of slot apparatus  34  is connected via a metal wire to one of the FPIC  20  pads, and the net routing between the external pads of slot apparatus  34  and the pads  38  is accomplished by programming the FPICs  20 .  
         [0025]    Because the slot apparatus  34  of the present invention includes four first-slot-modules  42 , the slot apparatus  34  may accommodate at least one bare-die  36 ,  37 . On the slot apparatus  34 , we can have four small bare-dies to attach on the four first-slot-modules  42 , as shown in FIG. 4, or a large bare-die  37  occupying all the four first-slot-modules  42 , as shown in FIG. 5. In addition, each of the first-slot-modules  42  includes a plurality of internal pads  44 . Therefore the slot apparatus  34  of the present invention may accommodate a plurality of bare-dies  36 ,  37  of different sizes and with different pad numbers. Similarly, the slot apparatus  34  of the present invention may also be used to connect a plurality of chips (not shown) to the PMCM  30 , where the chips refer to the packaged electronic components with a plurality of pins. Meanwhile, the slot apparatus  34  of the present invention may be applied to a high-density multi-layer programmable printed circuit board (not shown) to connect the bare-dies  36 ,  37  or the chips connected to the printed circuit board.  
         [0026]    Please refer to FIG. 6. FIG. 6 illustrates another embodiment of the slot apparatus  60  according to the present invention. The slot apparatus  60  of the embodiment includes four first-slot-modules  62 , each of the first-slot-modules  62  includes four second-slot-modules  64 , and each of the second-slot-modules  64  is residing on the MCM substrate  32  to accommodate at least one bare-die  41  (as shown in FIG. 7). Each of the second-slot-modules  64  includes a plurality of internal pads  44 , and each of the internal pads  44  can be connected to the pads of bare-dies  41 .  
         [0027]    In each of the second-slot-modules  64 , each pair of pads  44  in the A 1 -A 2  direction (or pads  44  in the B 1 -B 2  direction orthogonal to the A 1 -A 2  direction) is connected together through metal wiring  46 . The slot apparatus  60  of the present invention includes a plurality of external pads  48 , each external pad  48  is connected to a pair of the internal pads  44  in the A 1 -A 2  direction (or pads in the B 1 -B 2  direction orthogonal to the A 1 -A 2  direction). The external pads  48  of a slot apparatus  60  are connect to the pads of FPICs  20  through metal wiring  46 .  
         [0028]    Please refer to FIG. 7. FIG. 7 illustrates the first embodiment indicating the bare-dies  41 ,  37  attached on the slot apparatus  60  as shown in FIG. 6. The slot apparatus  60  accommodates twelve bare-dies  41  and a single bare-die  37 , and each bare-die  41 ,  37  includes a plurality of pads  50 . The pads  50  of each bare-die  41 ,  37  are connected to the internal pads  44  of the second-slot-modules  64  by using the wire-bonding technology. Each bare-die  41  is attached on a second-slot-module  64 , while the large bare-die  37  occupying and attaching on all the four second-slot-modules  64 . Each pad of slot apparatus  60  is connected via a metal wire to one of the FPIC  20  pads, and the net routing between the external pads  48  of slot apparatus  60  and the pads  38  is accomplished by programming the FPICs  20 .  
         [0029]    Please refer to FIG. 8. FIG. 8 illustrates the second embodiment of bare-dies  37  attached on the slot apparatus  60  (as shown in FIG. 6). The slot apparatus  60  accommodates four bare-dies  37 , and each bare-die  37  includes a plurality of pads  50 . The pads  50  of each bare-die  37  are connected to the internal pads  44  of the second-slot-modules  64  by using the wire-bonding technology, and each bare-die  37  is attached on four second-slot-modules  64 . Further, programming the FPIC  40  completes the net routing between the bare-dies  37  and the pads  38 .  
         [0030]    Please refer to FIG. 9. FIG. 9 illustrates the third embodiment a large bare-die  39  attached on the slot apparatus  60  as shown in FIG. 6. The bare-die  39  includes a plurality of pads  50 . The pads  50  of the bare-die  39  are connected to the internal pads  44  of the second-slot-modules  64  by using the wire-bonding technology, and the bare-die  39  is attached on sixteen second-slot-modules  64 .  
         [0031]    The slot apparatus  60  according to the embodiment of the present invention includes four first-slot-modules  62  and sixteen second-slot-modules  64 , and therefore the slot apparatus  60  of the present invention may accommodate at least one bare-die  37 ,  39 ,  41 . The slot apparatus  60  shown in FIG. 7 accommodates twelve bare-dies  41  and one single bare-die  37 , the slot apparatus  60  shown in FIG. 8 accommodates four bare-dies  37 , and the slot apparatus  60  shown in FIG. 9 accommodates only one single bare-die  39 . Furthermore, each of the second-slot-modules  64  includes a plurality of internal pads  44  so that the slot apparatus  60  of the present invention accommodates the bare-dies  37 ,  39 ,  41  with different sizes and with different pads numbers. In addition, the slot apparatus  60  of the present invention may be used to connect a plurality of chips (not shown) to the PMCM  30 . Meanwhile, the slot apparatus  60  of the present invention may be applied to a high-density multi-layer printed circuit board (not shown) to accommodate the bare-dies  36 ,  37 ,  39 ,  41 .  
         [0032]    The multi-chip module or the printed circuit board assembled by the slot apparatuses  34 ,  60  of the present invention has the following advantages when compared with the PMCM  10  of the prior art:  
         [0033]    1. The slot apparatus of the present invention may be applied to a multi-chip module or a printed circuit board to function as a general-purpose substrate. The bare-dies or chips with different sizes and with different pad numbers may be attached on the general-purpose substrate in a fast and convenient way. Therefore those expensive substrates are not necessary any more. The present invention saves much time and money and lowers the cost.  
         [0034]    2. The slot apparatus of the present invention may be applied to a PMCM or a programmable printed circuit board to function as a programmable general-purpose substrate. The slots and the FPICs on the PMCM are made and well tested in advance. The FPICs are attached on the general-purpose substrate and are provided to the user. Therefore, the PMCM assembled by the slot apparatuses of the present invention is easily error detecting and is easily to be modified. The present invention then reduces the probability of failure, increases the yield of the products, and accelerates the production process.  
         [0035]    It will be understood that certain features and sub-combinations are of utility and may be employed without reference to other features and sub-combinations as they are outlined within the claims. For example, the slot apparatus of the present invention includes a plurality of first-slot-modules, and each of the first-slot-modules may include a plurality of second-slot-modules. Each of the second-slot-modules may further include a plurality of smaller slot-modules. While the preferred embodiment and application of the invention has been described, it is apparent to those skilled in the art that the objects and features of the present invention are only limited as set forth in claims attached hereto.