KR101020340B1 - Mounting structure on printed circuit board of mobile communication terminal with 3g dual mode - Google Patents

Abstract

The present invention relates to a printed circuit board mounting structure of a third generation dual mode mobile communication terminal, in which an image camera, a liquid crystal display (LCD), and a digital signal processing (DSP) are additionally installed in one mobile communication terminal. When two radiation frequency (RF) units are implemented, the degradation of the radiation frequency (RF) sensitivity due to interference between components cannot be avoided by the conventional printed circuit board mounting structure, which causes a problem in basic communication of the mobile communication terminal. A problem arises. Therefore, using two printed circuit boards stacked with a plurality of substrates, radio frequency (RF) components are provided on two upper left and lower layers on one printed circuit board, and modem memories are provided on two right upper and lower surfaces. And digital signal processing (DSP) parts, cameras, and liquid crystal display (LCD) driving parts on the other printed circuit board, so that all digital parts of a third generation terminal for transmitting video calls and multimedia data Even when operating simultaneously with the radio frequency (RF) part, it is possible to prevent the deterioration of the radio frequency (RF) sensitivity to prevent the failure of the basic communication function in advance.

Description

Structure of printed circuit board of 3rd generation dual mode mobile communication terminal {MOUNTING STRUCTURE ON PRINTED CIRCUIT BOARD OF MOBILE COMMUNICATION TERMINAL WITH 3G DUAL MODE}

1 is a block diagram of a typical third generation (3G) terminal,

2 is a schematic diagram showing a printed circuit board mounting structure of a mobile communication terminal according to the prior art;

3 is a schematic diagram showing the principle of digital signal processing (DSP);

4 is a schematic diagram showing a printed circuit board mounting structure of a mobile communication terminal according to the present invention.

DESCRIPTION OF REFERENCE NUMERALS

2: camera

4: liquid crystal display (LCD)

10: keypad

20: digital components

30: Radio Frequency (RF) Components

40: modem memory                 

50: first printed circuit board (PCB)

60: second printed circuit board (PCB)

The present invention relates to a printed circuit board mounting structure of a third generation dual mode mobile communication terminal.

When mobile communication is classified into the technology development stage of wireless communication, the first generation is analog communication, the second generation is digital mobile communication oriented to voice service, the second generation is digital mobile communication oriented to data service, and the third generation is 3G ( W-CDMA) is classified as next generation communication based on multimedia service, and 4th generation broadband mobile communication service is actively reviewed.

The third generation dual mode mobile communication terminal is a terminal that can be compatible with any network, as well as having a roaming function of W-cdma and cdma2000 1x as well as video transmission and reception.

A configuration diagram of a general third generation (3G) terminal is shown in FIG.

The terminal component is largely composed of a radio frequency (RF) portion, an intermediate frequency (IF) portion, a baseband analog (BBA) portion, a baseband modem (BBM) portion, and the like.

The radio frequency (RF) part converts between a high frequency signal (Cellular: 800 MHz, PCS: 1.8 GHz, 3G: 2 GHz) and an intermediate frequency (approximately 100 MHz to 400 MHz) of a modulated carrier. Is responsible for the conversion between the intermediate frequency (IF) and the baseband (BB), and the baseband analog (BBA) portion is responsible for the conversion of the analog and digital signals of the baseband (BB). The baseband modem (BBM) is the core of the terminal and controls the input / output signals of the display panel and keypad and the voice input / output of the microphone and the speaker.

A brief description of the configuration of the main components of Figure 1 and the signal flow procedure between each component is as follows.

The radio frequency (RF) component of the terminal is an active component, which is a low noise amplifier (LNA), an up / down converter or mixer, an intermediate frequency amplifier (IF Amp), a driver amplifier, and a power amplifier. ), A frequency synthesizer, and a passive component, which consists of a duplexer and a bandpass filter. Upon reception, the radio frequency (RF) signal input from the antenna is separated by only the reception frequency signal by a duplexer and then amplified by a low noise amplifier (LNA). The received frequency signal is then converted to an intermediate frequency IF by a down converter, then amplified by an intermediate frequency amplifier IF Amp, and then sent to the intermediate frequency IF signal processor. When transmitting conversely, the intermediate frequency (IF) transmission signal output from the intermediate frequency (IF) signal processing unit is converted into a radiation frequency (RF) signal by an up-frequency mixer, and the radiation frequency (RF) signal is After being amplified by the driver amplifier, the signal input from the power amplifier is amplified and transmitted to the base station through the antenna.                         

The intermediate frequency (IF) portion is composed of an automatic gain controller (AGC) that controls the magnitude of the signal, a frequency frequency synthesizer and a mixer. The automatic gain controller (AGC) adjusts the S / N ratio to a certain level so that the gain is automatically changed at an appropriate level so that the input / output signal is not weak or excessively large.

The baseband analog (BBA) portion consists of a modem, a low pass filter (LPF), an analog / digital converter (A / D converter), and the like. In transmission, the digital signal is converted into an analog signal, and then passed through a low pass filter (LPF) to filter out the low band signal and modulate it into an intermediate frequency (IF) signal. Upon reception, the baseband (BB) signal is extracted by demodulating the signal received at the intermediate frequency (IF) part, and the low-band analog signal is filtered and converted into a digital signal.

The baseband modem (BBM) is composed of a central processing unit (CPU) and a vocoder for coding of voice. It is the core part of the terminal component. It is responsible for all the input / output functions between the terminal and the user, including arithmetic / control functions. These components are also called mobile station modems (MSMs).

A voltage controlled oscillator (VCO) allows the output of the desired oscillation frequency with an externally applied voltage.

The oscillation frequency obtained through the X-tal Oscillator (XO) varies considerably with temperature. Therefore, in order to stably obtain a precisely defined frequency, it is necessary to compensate for the change according to the temperature, and the implementation by compensating for this is called a temperature compensated crystal oscillator (TCXO).

For all applications that use accurate frequency signals, a temperature compensated crystal oscillator (TCXO) is essential. In the case of mobile communication terminals, the accuracy of the temperature compensated crystal oscillator (TCXO) has a great effect on the overall performance as well as a considerable cost and area, and is a high power consumption component. The temperature compensated crystal oscillator (TCXO) is a core oscillation device of a mobile communication terminal that oscillates a designated signal of frequency.

In general, a printed circuit board is a kind of electronic component formed by forming a copper conductor having good electrical conductivity on an electrical insulator, and interconnecting and supporting each other so that an acoustic or image element can perform its function. It is the organization in charge of.

The first perception of printed circuit boards dates back to the 18th century, but was specifically made by Hansen, England in 1903, and in 1941, the English circuit was printed by etching the copper clads by British icesters. By devising a manufacturing method, a modern printed circuit board has been established.

In 1945, the National Buncan of Standard was used for shell fuses and mass-produced. Since then, it has grown steadily along with the development of component technologies such as transistor development. Increasingly, efforts for high precision have been made by introducing CAD / CAM systems.

Printed circuit boards (PCBs) include printed circuit boards used for specific purposes in addition to single-layer printed circuit boards, double-sided printed circuit boards and multilayer printed circuit boards.

Single side PCB is a printed circuit board in which the circuit is formed only on one side. It is low in density and simple in manufacturing method, so it is mainly used for mass production for TV, VTR, audio, etc. do. Double side PCB is a printed circuit board with circuits formed on both sides of upper and lower sides, and it is possible to mount high density parts compared to single-sided printed circuit boards. The upper and lower circuits are connected by through holes. It is mainly used for low-function office equipment such as printers and fax machines and low-cost industrial equipment. In addition, the multi-layered printed circuit board with inner layer and outer layer circuits is a product that enables high-density component mounting and shortening of wiring distance by three-dimensional wiring, and is mainly used for large computers, personal computers, communication equipment, and small appliances. Used for equipment.

On the other hand, in order to reduce the area occupied by the via holes due to the increase in the number of layers due to the increase in the amount of wiring in the design of high-density printed circuit boards due to the miniaturization of electronic devices, the circuits can be selectively connected in each layer. In order to minimize the area occupied by the hole for circuit connection by processing the partial via hole, a printed circuit board called IVH MLB (Interstitial Via Hole Muti-layer Board) is used. This printed circuit board is mainly used for high-performance small electronic devices such as mobile phones, notebook PCs and PDAs.

Figure 2 shows a printed circuit board mounting structure of a mobile communication terminal according to the prior art.

As shown, one radio frequency (RF) component 30 is mounted on the left side of the lower layer, one modem memory 40 is mounted on the right side of the lower layer, and digital signal processing (DSP) on the upper layer. A first printed circuit board 50 stacked with a plurality of substrates B on which digital parts 20 such as a camera and a liquid crystal display (LCD) driving part are mounted; Only a simple component, such as a keypad 10, is mounted on the upper layer surface, and is composed of a second printed circuit board 60 stacked on a plurality of substrates B. As shown in FIG. In addition, the second and third layers of the first printed circuit board 50 are divided with the signal power ground 6, and the radiation frequency (RF) ground 8 is the first printed near the receiving antenna (not shown). It is formed only on the left side of the circuit board 50.

In addition, a partial via hole (not shown) is processed so that the circuit connection can be selectively performed for each layer of each substrate (B), and the via hole (not shown) is formed on the upper and lower surfaces of the printed circuit boards 50 and 60. Is to connect. First, the hole is processed, and the inner wall of the hole is copper plated to electrically connect the upper and lower surfaces of the substrate B through the hole. That is, the via holes are formed through hole processing and plating on the inner wall.

The ground for the signal power supply 6 acts to intrude the electronic noise from the outside and passes only the appropriate frequency through the radiation frequency (RF) ground (8) to operate the radiation frequency (RF) component (30) from the antenna. The received radio frequency (RF) signal is transmitted to the modem 40. At this time, the signal is demodulated and immediately processed to the speaker output stage, and the digital components 20 such as a digital signal processing (DSP) and a camera and a liquid crystal display (LCD) driving component mounted on the upper surface of the first printed circuit board 50 are provided. ) And the signal (S) is exchanged. This signal (S) is a high-speed digital data (D) such as video and multimedia, and interfaces (I) with the keypad (10) mounted on the second printed circuit board (60), such as the camera (2) and the LCD (4). The devices are driven and, conversely, the data obtained from these devices is processed in the keypad 10 or the digital component 20 and the modem memory 40 or the like.

The principle of such Digital Signal Processing (DSP) is schematically shown in FIG.

Digital signal processing (DSP) expresses the signal values using 1 and 0 at regular time intervals, but at least in time, to maintain the shape, at least in order to bring the time-continuous signal to a general calculator such as a computer. The data values are imported to a computer and processed properly. The term computer is used. Generally, a processor designed to operate optimally for processing 1s and 0s, that is, an algorithm that is operated efficiently and in real time is called a digital signal processing (DSP) processor.

As one of the advantages of the digital signal processing (DSP), for example, in the case of analog, a circuit is formed using elements such as a transistor (TR) and a resistor (R) to be fixed to one application device, while the digital signal processing ( DSP) basically amplifies the digital signal processing processor by simply multiplying the input signal by the appropriate value, and it can be used as another function by changing the built-in program.

As shown, the voice which is the analog signal 100 input to the microphone of the mobile communication terminal is converted into a digital signal 200 represented by 1 and 0 by an analog / digital converter (A / D converter) 110. . The digital signal processing (DSP) 120 removes noise from the digital signal 200 converted at the time of input and compresses it for transmission. Next, the receiver's mobile phone converts the digital signal 200 into an analog signal 100 by a digital / analog converter (D / A converter) 130 so that the receiver can hear the caller's voice. have.

However, in the conventional mobile communication terminal, a simple structure is performed in one modem to demodulate a signal transmitted from a radio frequency (RF) circuit, process the signal, and process the signal directly to a speaker output terminal. It's about one level. Therefore, a radio frequency (RF) component is mounted on the left side of the lower layer of the printed circuit board, a modem memory is mounted on the right side of the lower layer, and a simple component such as a keypad is mounted on the upper layer. Although the effect on the RF signal is minimal, one mobile communication terminal is additionally equipped with a video camera, a liquid crystal display (LCD) and a digital signal processing (DSP), and two radio frequency (RF) units of dual mode are implemented. In the conventional printed circuit board mounting structure, the degradation of the radiation frequency (RF) sensitivity due to the interference between components is inevitable, which causes a problem in the basic communication of the mobile communication terminal. In particular, in the case of a clamshell mobile communication terminal, since most cameras and liquid crystal displays (LCDs) are located at the top, there is a problem that the influence on the radiation frequency (RF) portion close to the antenna becomes more serious.

Accordingly, an object of the present invention is to use two printed circuit boards stacked with a plurality of substrates, and to form a radio frequency (RF) component on two upper left and lower layers of one printed circuit board. The modem memory is mounted in two places on the right side, and the digital signal processing (DSP) part and the camera and liquid crystal display (LCD) driving part are mounted on the other printed circuit board. It is to provide a printed circuit board mounting structure of the third generation dual mode mobile communication terminal that can solve the interference of the communication function.

In order to achieve the above object, the present invention is a radio frequency (RF) component which is mounted in two places on the left side of the upper and lower layers and converts between a high frequency signal and an intermediate frequency of a modulated carrier, and the radiation frequency A first printed circuit board laminated with a plurality of substrates each demodulating the signal transmitted from the (RF) component and processing the signal, and a memory storing the signal is mounted on two upper right and lower layers respectively; Parts that drive the camera, Liquid Crystal Display (LCD) parts that process video signals, and Digital Signal Processing (DSP) parts that process digital signals and compress the images captured by the camera and transmit them to the Liquid Crystal Display (LCD). And a second printed circuit board mounted on the lower surface, the keypad mounted on the upper surface, and stacked on a plurality of substrates.

According to the present invention, it is preferable that the RF frequency component and the modem have a signal power ground divided into two layers and three layers so that the analog ground and the digital ground are narrowly connected through the via hole.

In addition, according to the present invention, the second printed circuit board is preferably separated from the first printed circuit board to form a pure digital printed circuit board and wired.

Hereinafter, preferred embodiments of the present invention will be described in more detail with reference to the accompanying drawings, which are intended to explain in detail enough to be able to easily carry out the invention by one of ordinary skill in the art. This does not mean that the technical spirit and scope of the present invention are limited.

4 illustrates a printed circuit board mounting structure of a mobile communication terminal according to the present invention.

As shown, a first printed circuit board having two radio frequency (RF) components 30 mounted on the left side of the upper and lower layers, and two modem memories 40 mounted on the right side of the upper and lower layers, respectively. 50 and a simple component such as a keypad 10 are mounted on an upper layer, and a digital component 20 such as a component for driving a digital signal processing (DSP) and a camera and a liquid crystal display (LCD) is mounted on a lower layer. The second printed circuit board 60 is formed. In addition, the first printed circuit board 50 and the second printed circuit board 60 are formed by stacking a plurality of substrates (B). The second and third floors of the first printed circuit board 50 are divided by the ground for the signal power supply 6, and the radiation frequency (RF) ground 8 is the first printed circuit board near the receiving antenna (not shown). (50) It is formed only in the left side.

In addition, a partial via hole (not shown) is processed so that the circuit connection can be selectively performed for each layer of each substrate (B), and the via hole (not shown) is formed on the upper and lower surfaces of the printed circuit boards 50 and 60. Is to connect. First, the hole is processed, and the inner wall of the hole is copper plated to electrically connect the upper and lower surfaces of the substrate B through the hole. That is, the via holes are formed through hole processing and plating on the inner wall.

The ground for the signal power supply 6 acts to intrude the electronic noise from the outside, and only the appropriate frequency passes through the radio frequency (RF) ground 8 to operate the dual radio frequency (RF) component 30 to operate the antenna. Radio frequency (RF) signal received from the dual modem 40 is to be transmitted. At this time, the modem demodulates and processes the received radio frequency (RF) signal to process the speaker output terminal. In addition, a device such as a camera 2 and a liquid crystal display (LCD) 4 may interface with the keypad 10 mounted on the second printed circuit board 60 while the high speed digital data D such as an image and a multimedia may be used. The signals S and the data obtained from these devices are processed in the keypad 10 or the digital component 20 and the modem memory 40 or the like.

As described above, the printed circuit board mounting structure of the third generation dual mode mobile communication terminal according to the present invention uses two printed circuit boards stacked with a plurality of substrates to form a left side of the upper and lower layers of one printed circuit board. Radio frequency (RF) components are installed in two places, and modem memory is mounted in two places on the upper and lower layers, and digital signal processing (DSP) components, cameras and liquid crystal displays (LCDs) are driven on the other printed circuit board. By mounting the components, even if all digital parts operate simultaneously with the radio frequency (RF) part in the 3rd generation (3G) terminal that transmits video call and multimedia data, the radio frequency (RF) part does not pass the digital signal to the radiation By preventing the deterioration of the frequency (RF) sensitivity, it is possible to prevent the failure of the basic communication function in advance.

Claims (3)

Radio frequency (RF) components for converting between the high frequency signal and the intermediate frequency of the modulated carrier are mounted on two upper left and bottom layers, and the signals transmitted from the radio frequency (RF) components are demodulated. A first printed circuit board laminated with a plurality of substrates each having a modem for processing signals and a memory for storing signals on two upper right and lower layers; It consists of an upper layer and a lower layer, the lower side is a liquid crystal display by compressing a component for driving a camera, a liquid crystal display (LCD) component for processing a video signal, and processing a digital signal and the image taken by the camera A third generation dual mode in which a digital signal processing (DSP) component for transmitting to the LCD is mounted, and the upper layer includes a second printed circuit board mounted on a plurality of substrates for mounting a keypad; Mobile terminal. 2. The RF device of claim 1 wherein the radio frequency (RF) component and modem A third generation dual mode mobile communication terminal, characterized in that the basic ground is divided into two layers and three floors so that analog ground and digital ground are connected through a via hole. The method of claim 1, wherein the second printed circuit board The third generation dual mode mobile communication terminal, characterized in that the wiring to form a digital printed circuit board by being separated from the first printed circuit board.

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