Abstract:
In a passive network, such as a CC array in the form of a chip, internal conductors of a number of capacitors are led out at a longitudinal side surface of a chip wafer as terminals therefor. Common frame electrodes of the number of capacitors are, in contrast, led out at both frontal side surfaces of the chip wafer.

Description:
BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The present invention relates to a passive network in the form of a chip and, more specifically, to a passive network, such as a CC (Chip-Capacitor) array in the form of a chip, wherein internal conductors of a number of capacitors are lead out at a longitudinal side surface of a chip wafer as terminals and frame electrodes of the capacitors are led out at both frontal side surfaces of the chip wafer. 
     SUMMARY OF THE INVENTION 
     According to the present invention, for the creation of CC (Chip Capacitor) arrays, internal conductors of a number of capacitors on one longitudinal side surface of a chip wafer are led out as terminals, while common frame electrodes of the number of capacitors are led out at both side surfaces of the chip wafer. 
     A CC array constructed according to the present invention can, for example find application for interference suppression at terminal lines of microcontrollers. preferably, in a PLCC (Plastic Leaded Chip Carrier) housing, or in connection with integrated circuits (IC&#39;s), hybrid components, and others. 
     A particular advantage in this construction of a CC array according to the present invention is that terminals which conduct voltage, called “hot” terminals of the individual capacitors, are routed very close to the integrated circuit (IC) and the associated terminals lines can be further routed under the CC array. The routing of the voltage-carrying terminals very close to the integrated circuit satisfies a requirement of experts in the EMI (Electro-Magnetic Interference), field which states that the closer a capacitor is located to the terminals of the integrated circuit, the smaller the required capacitance value can be. For the user, this yields further advantages with respect to a considerable savings of space in relation to individual capacitors, as well as a lower equipping expense. 
     According to an embodiment of the present invention, corresponding to the provided module design for CCR (Chip-Capacitor-Resistor) arrays, resistance regions additionally need be applied on a surface of a chip wafer only in a number corresponding to the number of capacitors. Terminals of the individual resistance regions are on the one hand, respectively connected with the internal conductor of an allocated capacitor and, on the other hand are led out at the second longitudinal side surface of the chip wafer. Analogous to the above-described embodiment of a CC array according to the present invention, a passive network expanded to form a CCR array also can be used for the suppression of interference on lines. An additional advantage of this embodiment is the higher effectiveness of the RC element or elements created. 
     In the provided module system, according to the present invention a passive network for CCRL arrays can be created (Chip-Capacitor-Resistor-Inductance) wherein a ferrite wafer is applied on the surface of the above-described resistance layer regions. 
     By means of this expansion of a passive network in the form of a CCRL array, there results an additional advantage; namely, the higher effectiveness of the CCRL array due to the addition of an inductance L to the RC elements. 
     In order to achieve a suppression of interference in the RF range, conductors are typically plugged through small ferrite tubes. The effectiveness of open magnetic circuits in which an interconnect is located parallel to the ferrite surface is thus somewhat smaller. For this reason, in the inventive design of a CCRL array the effectiveness of the open magnetic circuits comes into play only in the higher frequency range, i.e., in a frequency range above 100 MHz. 
     An electrical component in chip form is particularly advantageous when constructed with the depicted passive network, wherein interconnects are arranged on a board, and are connected with a CC array or with a CCR array, and wherein a microcontroller is connected with the interconnects via terminals. 
     In an arrangement with a CC array, the interconnects are guided through under the CC array. Conversely in an arrangement with a CCR array the interconnects are not led through under the CCR array. 
     Additional features and advantages of the present invention are described in, and will be apparent from, the Detailed Description of the Preferred Embodiments and the Drawing. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     FIG. 1 a  schematically shows an enlarged perspective view of a part of a passive network of the present invention as a CC array; 
     FIG. 1 b  schematically shows an enlarged perspective view of a CC array of the present invention in the form of a chip; 
     FIG. 1 c  shows a sectional view of the CC array of FIG. 1 b;    
     FIG. 1 d  shows an equivalent circuit diagram of the CC array of FIGS. 1 b  and  1   c;    
     FIG. 2 a  shows a section of the design of an arrangement of a CC array on a board; 
     FIG. 2 b  shows a top view of the design arrangement of FIG. 2 a;    
     FIG. 3 a  schematically shows an enlarged perspective view of a part of a network according to the present invention as a CCR array; 
     FIG. 3 b  schematically shows an enlarged perspective view of a CCR array of the present invention in the form of a chip; 
     FIG. 3 c  shows a sectional view of the CCR array of FIG. 3 b;    
     FIG. 3 d  shows an equivalent circuit diagram of a CCR array of FIGS. 3 b  and  3   c;    
     FIG. 3 e  shows an equivalent circuit diagram of an RC element; 
     FIG. 4 a  shows a sectional view of the design of an arrangement of a CCR array on a board; 
     FIG. 4 b  shows a top view of the design arrangement of FIG. 4 a;    
     FIG. 5 a  schematically shows an enlarged perspective view of a part of a passive network of the present invention as a CCRL array; 
     FIG. 5 b  schematically shows an enlarged perspective view of a CCRL array in the form of a chip; 
     FIG. 5 c  shows a sectional view of the CCRL array of FIG. 5 b;    
     FIG. 5 d  shows an equivalent circuit diagram of a CCRL array of FIGS. 5 b  and  5   c ; and 
     FIG. 5 e  shows an equivalent circuit diagram of an RCL element. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 1 a  schematically shows an enlarged perspective view of a part of a passive network in the form of a CC array  10 . In FIG. 1 a , a common frame electrode ME is formed on a frontal side surface S 1  as an electrode  0  which, as can be seen in FIGS. 1 b  and  1   c , completely covers the frontal side surface S 1 . In addition, an electrode E 1  of, for example, a first capacitor C 1  is shown from which a line indicated by an arrow leads to an external terminal  1  without contacting the frame electrode ME in the one longitudinal side surface L 1  of the CC array chip. 
     FIG. 1 b  is a schematic enlarged perspective view of a chip  10  in the form of a CC array, while FIG. 1 c  is a sectional view of the CC array  10 . In FIGS. 1 b  and  1   c , a frame electrode  0  is respectively provided at both frontal side surfaces S 1  and S 2 . In addition, in FIG. 1 c  the terminals  1  to  4  provided on the one longitudinal side surface L 1  can be seen. FIG. 1 d  is merely an equivalent circuit diagram of a CC array with four capacitors C 1  to C 4 , the terminals  1  to  4 , and the frame terminal  0 . 
     In FIGS. 2 a  and  2   b , the design of an arrangement of various components is shown in a section and, respectively, a top view. Interconnects  7  are provided on a board P from which terminals  8  lead, for example, to a microcontroller  6 . As can be seen in the sectional view in FIG. 2 a , the interconnects  7  are led through under the chip  10  with the CC array. In the sectional view of FIG. 2 a  a terminal  3  can be seen and, in the top view of FIG. 2 b  the terminals  1  to  4  can be seen. 
     FIG. 3 a  is an enlarged perspective view corresponding to FIG. 1 a , of a part of a passive network in the form of a CCR array which, thus, represents a development of the CC array shown in FIG. 1 a . In development of the embodiment shown in FIG. 1 a , in FIG. 3 a  a resistance layer, for example corresponding to a resistor R 1 , is applied on a surface  21  of a chip  20 . 
     As indicated in the schematic view of FIG. 3 a , one end of the resistance layer R 1  is connected with the terminal  1  formed in the longitudinal side surface L 1 , while the other end of the resistance layer R 1 , as indicated by a broken arrow, is connected with a terminal A formed on the other longitudinal side surface L 2 . 
     The representations in FIGS. 3 b  and  3   c  correspond to the representations in FIGS. 1 b  and  1   c , with the difference being that in FIG. 3 b  four resistance regions R 1  to R 4  are additionally provided on the upper side  21  of the chip wafer  20 . Such regions, as can be seen in the sectional view of FIG. 3 c , are connected with terminals A to D provided on the second longitudinal side surface L 2 . 
     The equivalent circuit diagram in FIG. 3 d  is an expansion of the equivalent circuit diagram in FIG. 1 d  because resistors R 1  to R 4 , corresponding to the four resistance layer regions (R 1  to R 4 ) are connected in series to the four capacitors C 1  to C 4 . Resistors R 1  to R 4  are connected on the one hand with the terminals  1  to  4  provided on the one longitudinal side surface L 1 , and on the other hand with the terminals A to D provided on the opposite-lying longitudinal side surface L 2 . FIG. 3 d  is merely an equivalent circuit diagram of an RC element formed from the capacitor C 1  and the resistor R 1 . 
     The sectional view in FIG. 4 a  and the top view in FIG. 4 b  essentially correspond to the representations in FIGS. 2 a  and  2   b , with the difference being that instead of the CC array  10  in FIGS. 2 a  and  2   b , a CCR array  20  with a resistance layer R is now arranged on the board P. A further difference between the representations in FIGS. 4 a  and  4   b  with respect to the representations in FIGS. 2 a  and  2   b  is that interconnects  7 ′ are not led through under the CCR array  20 . 
     The perspective and enlarged schematic view of a part of a passive network in the form of a CCLR array in FIG. 5 a  is a development of the CCR array shown in FIG. 3 a , wherein a ferrite wafer F is applied on the surface of the resistance layer R 1 . The design under the ferrite wafer F is identical with the design, described on the basis of FIG. 3 a , of the CCR array chip  20 . 
     The representation in FIG. 5 b  differs from the representation in FIG. 3 b  only in the ferrite wafer F applied on the resistance regions R 1  to R 4  in FIG. 3 b . Since the ferrite wafer F in the sectional view of FIG. 5 c  cannot be shown, the sectional view of FIG. 5 c  corresponds to that of FIG. 3 c.    
     The equivalent circuit diagram of the CCRL array in FIG. 5 d  is shown as a comparison with the equivalent circuit diagram of the CCR array in FIG. 3 d , expanded by four inductances L 1  to L 4  connected in series with the resistors R 1  to R 4 . FIG. 5 e  merely shows an equivalent circuit diagram of an RCL element formed from the inductance L 1 , the resistor R 1  and the capacitor C 1 . 
     Although the present invention has been described with reference to specific embodiments, those of skill in the art will recognize that changes may be made thereto without departing from the spirit and scope of the invention as set forth in the hereafter appended claims.