Abstract:
An apparatus is disclosed for a module structure of a mobile communication terminal. The module structure comprises a radio frequency portion for processing communicated radio frequency signals, and a base-band portion commonly used by the radio frequency portion for providing modular replacement of a radio frequency multi-chip module connected to the radio frequency portion. The radio frequency multi-chip module is selected in accordance with a corresponding frequency band of the mobile communication terminal.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
   Pursuant to 35 U.S.C. §119(a), this application claims the benefit of the earlier filing date and right of priority to Korean Application No. 10-2003-0100748, filed on Dec. 30, 2003, the contents of which are hereby incorporated by reference herein in its entirety. 
   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to a structure having a radio frequency multi-chip module that is replaceable from the RF portion of a mobile communication terminal. 
   2. Description of the Related Art 
     FIG. 1  is a block diagram of a general mobile communication terminal. 
   Referring to  FIG. 1 , a mobile communication terminal includes a radio frequency (RF) system  10 , a base-band system  20 , and a peripheral device  30 . 
   The RF system  10  provides an antenna, a transmission unit, a reception unit and a local oscillator (LO). The base-band system  20  has a mobile station modem (MSM) chip corresponding to a central processing unit (CPU) of a computer. The base-band system also provides a memory and peripheral devices. 
   The peripheral device  30  provides a user with an output signal of the base-band system  20  or transmits a signal inputted by a user to the base-band system  20 . The peripheral device  30  generally includes a speaker, a microphone, a keypad, a liquid crystal display (LCD), a camera or the like. 
   For miniaturizing size and improving transmission and/or reception performance of a mobile terminal through elimination of signal interference, the RF system  10  and the base-band system  20 , in the conventional art, are integrated on a single board. 
   If an RF frequency band, such as PCS, CDMA, AMPS, of the RF system changes, the RF system needs to be re-designed. Consequently, the conventional art has a disadvantage that the board requires redesign when the RF frequency band changes even though the base-band chip set remains the same. Therefore, there is a need for a system that overcomes the above problem and provides advantages over other integrated RF and base-band systems. 
   SUMMARY OF THE INVENTION 
   Features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings. 
   In one embodiment, a module structure of a mobile communication terminal is disclosed. The module structure comprises a radio frequency portion for processing communicated radio frequency signals, and a base-band portion commonly used by the radio frequency portion for providing modular replacement of a radio frequency multi-chip module connected to the radio frequency portion. The radio frequency multi-chip module is selected in accordance with a corresponding frequency band of the mobile communication terminal. 
   The RF multi-chip module may be implemented utilizing a lead free type of interconnection scheme with the base-band portion. The RF multi-chip module may, in another example, be implemented utilizing a lead type of electrical interconnection scheme with the base-band portion. In another exemplary example, the RF multi-chip module may be implemented utilizing a connector type of electrical interconnection scheme with the base-band portion. 
   The RF multi-chip module preferably comprises a board, a plurality of RF components mounted on the board, and a cap for isolating the RF components from the exterior environment from electrical interference signals. The board is preferably a ceramic laminated board. 
   Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed. 
   These and other embodiments will also become readily apparent to those skilled in the art from the following detailed description of the embodiments having reference to the attached figures, the invention not being limited to any particular embodiments disclosed. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention. 
     Features, elements, and aspects of the invention that are referenced by the same numerals in different figures represent the same, equivalent, or similar features, elements, or aspects in accordance with one or more embodiments. 
       FIG. 1  is block diagram illustrating a conventional configuration of a mobile communication terminal. 
       FIG. 2  is a cross-sectional view of an RF multi-chip module in accordance with an embodiment of the present invention. 
       FIG. 3  is an RF package layout showing various types of connection terminals of a RF multi-chip module in accordance with an embodiment of the present invention. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   The invention relates to a module structure having a radio frequency multi-chip module that may be modularly replaceable from the RF portion of the module structure for a mobile communication terminal. 
   Although the invention is illustrated with respect to a mobile terminal, it is contemplated that the invention may be utilized anywhere it is desired for packaging RF and base-band components within a single package. Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. 
   The present invention provides an RF multi-chip module (MCM) with is part of a modularized RF portion of a mobile communication terminal. The RF portion is integrated, on the mobile terminal, with a base-band portion into one chip. 
   A base-band portion is commonly used with a chipset and a desired RF MCM is replaceably inserted thereto according to the frequency utilized in the specific area, so that a mobile communication terminal may be easily fabricated in a short period of time without the need for designing a new RF board. 
     FIG. 2  is a cross-sectional view of an RF MCM in accordance with an embodiment of the present invention. A plurality of wires are formed on an upper surface of a board  50  for allowing transfer of signals. A transmission unit  52  and a reception unit  53  are separately mounted on the board  50 . A cap  54  provides signal isolation of the transmission unit  52  and the reception unit  53  from the exterior environment (not shown). 
   The board  50 , for example, may be formed by a low temperature co-fired ceramic (LTCC) laminated board, a high co-fired ceramic (HTCC) laminated board, or a general FR-4 printed circuit board (PCB). The general FR-4 printed circuit board may be of a two-sided epoxy construction. The cap  30  is implemented, in one exemplary embodiment, utilizing an epoxy molding or, in yet another example, utilizing a metal shield. 
   The RF MCM in accordance with the present invention will now be described in detail. 
   The FR-4 is preferably utilized as the material for the multi-layer board  50  of the RF MCM. Wires  51  are mounted on a chip of the board  50 . Wires  51  are utilized for separately mounting a transmission unit  52  and a reception unit  53  deposited on the board. 
   The board  50 , in this exemplary example, is an LTCC. The LTCC is a ceramic board formed by laminating ceramic sheets. The LTCC having a dielectric nearly twice as high as that of FR-4 reduces board dimensionality and accordingly reduces the board size. Because the LTCC has a good heat conductivity, the heat generated, for example, by a power amplifier module (PAM) may be efficiently removed from the board  50 . The reduced heating will reduce the temperature of the mobile terminal. 
     FIG. 3  is an RF package layout showing various connection terminals of an RF MCM in accordance with the present invention. The RF MCM maybe a lead free type or a leaded type in accordance with the type of pins used for electrical interconnections the mobile terminal. In one alternative, connectors may be used in place of pins. In one example, reference number  60  is a connector for a connector type RF MCM and reference number  61  is a cap. 
   An RF system may be implemented within an RF MCM through mounting the components on a board  50  using various mounting methods such as those described in the above  FIG. 2 . Operation of the RF MCM is the same as that of the RF system, and a board  50  may be utilized for the RF MCM using LTCC. 
   Each component, in this example, has a bare-die state and is wire-bonded to the LTCC during fabrication of an RF MCM. A transmission unit  52  and a reception unit  53  are positioned along the wires  51  of the board  50 . Wire-bonding is utilized to complete fabrication of the RF MCM. 
   Components which have been previously modularized are soldered to the LTCC during fabrication of an RF MCM. In one example, a transmission unit  52  and a reception unit  53  being previously modularized are respectively positioned on the wires  51  and soldered to the LTCC during fabrication of an RF MCM. 
   The RF MCM is covered with a cap  54  to provide isolation from an exterior environment. The cap  54  of the RF MCM may fabricated either using an epoxy molding method like that of an IC package for covering the board. In another example, a shielded metal may be utilized to block unwanted wave interference to increase ESD protection and GNDing affects. 
   As so far described in the present invention, the RF portion is separately modularized in a mobile communication terminal. The base-band portion is commonly used by the RF portion. The RF module is replaced depending on the type of service provider, such as PCS, CDMA, Tri-Mode or the like. The replacement of the RF module provides a mobile terminal with smooth frequency transitions between various frequency bands. 
   In the present invention, an RF MCM obtained by separately modularizing an RF part eliminates the need for new circuits to be designed even in an area using a different frequency to readily reconfigure a mobile terminal in a short time period. 
   The present invention provides a reduced board size by fabricating an RF MCM using an LTCC board having a ceramic laminated board instead of with an FR-4 board. The LTCC board efficiently radiates heat generated within the board so that the overall temperature of the mobile terminal is reduced. 
   As the present invention may be embodied in several forms without departing from the spirit or essential characteristics thereof, it should also be understood that the above-described embodiments are not limited by any of the details of the foregoing description, unless otherwise specified, but rather should be construed broadly within its spirit and scope as defined in the appended claims, and therefore all changes and modifications that fall within the metes and bounds of the claims, or equivalence of such metes and bounds are therefore intended to be embraced by the appended claims. 
   Although the present invention is described in the context of a mobile terminal, the present invention may also be used in any wired or wireless communication systems using mobile devices, such as PDAs and laptop computers equipped with wired and wireless communication capabilities. Moreover, the use of certain terms to describe the present invention should not limit the scope of the present invention to certain type of wireless communication system, such as UMTS. The present invention is also applicable to other wireless communication systems using different air interfaces and/or physical layers, for example, TDMA, CDMA, FDMA, WCDMA, etc.