JPH11352915A - Compound function circuit part for real time clock circuit and liquid crystal driver, and electronic information equipment using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To standardize a compound function circuit part to be supplied, and to reduce the cost through rationalization, standardization and mass-production effects for a functional circuit portion by mounting circuit elements for a real time clock circuit(RTC) and a liquid crystal driver(LCD) on the same board to be formed into a single component as the compound function circuit part. SOLUTION: A compound circuit board 61 is mounted with an RTC and an LCD, and mounted with ICs and parts constituting respective circuits to be sealed in the same package. Single-functional circuit ICs 11, 31, a quartz oscillator 12, capacitors 13, 33, 34, a resistor 32 and the like are arranged on an upper surface. Input terminals 15, 35 for each single-functional circuit and a power source terminal are provided in a periphery. This comprises gold plantings in inner faces of through holes provided in a large-sized board material, and gold patterns in lower faces connected to them, and inner face electrodes are exposed to form side face electrodes accompanied with lower face electrodes having small areas, when divided longitudinally and laterally by vertical planes passing through the through holes. The electrodes serve as electrodes for SMDs for mounting the compound circuit board 61 on a motor board of an integrated circuit.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improved configuration relating to a real-time clock circuit and each functional circuit of a liquid crystal driver suitable for use in electronic information equipment, and an electronic information equipment using the same.

[0002]

2. Description of the Related Art Electronic devices for handling information such as mobile phones, pagers, cordless phones, AV devices, OA devices, etc. have become widespread and are increasingly used day by day. At the same time, the advancement and improvement of electronic information devices, that is, miniaturization, thinning, low cost, diversification of functions, improvement of operation speed, change of device design specifications, reduction of development steps for new models, reduction of development costs, etc. Are increasingly fierce.

[0003] These electronic information devices include circuits having various functions. Among them, circuits that are used frequently control the operation date and time of the device and external devices,
There are a real-time clock circuit (hereinafter abbreviated as RTC) for providing time and calendar information to a user and a liquid crystal driver (hereinafter abbreviated as LCD) for controlling and driving a liquid crystal display device for displaying information.

[0004] In a known conventional example, in order to comprehensively reduce the size of an electronic circuit portion of an electronic information device,
Along with other various functional circuits, circuits such as an RTC and an LCD are arranged on a single large substrate in a defined manner, and the components are mounted. That is, RT on a single large substrate surface
The components of the C, LCD, and other necessary circuits are arranged as densely as possible, and they are connected by wiring of a printed circuit formed at the same time, and soldered all together to form an entire circuit. Note that each function of the RTC and the LCD is performed by each integrated circuit, and a flat package IC is generally used for the form.

FIGS. 3A and 3B are individual block diagrams of respective element circuits relating to the present invention, a conventional example, and all of the reference examples described later. FIG. 3A shows an RTC, and FIG. 3B shows an LCD. Each element circuit is inside a frame shown by a dotted line. RTC1 is RT
The LCD 3 comprises an IC 11 for C, a crystal oscillator 12 and a capacitor 13 serving as a load capacitance for oscillation.
C31, a resistor 32 for oscillation, a capacitor 33, and a capacitor 34 for contrast adjustment.

[0006] VDD and VSS in FIG. 3 are power supply terminals. Others are signal input / output terminals, (a) CS (Chip Select) is a terminal that determines the communication state between the circuit and an external CPU (not shown), and SCK (Serial ClocK) is data given to the SIO terminal. SIO (Serial Input O)
utput) becomes an input terminal when the CS terminal is in a communication state, and thereafter is set to an input terminal or an output terminal according to an input command. These are collectively shown as input / output terminals 15.

(B) LC DATA is an input terminal of a signal for selecting an output signal of the following common and segment terminals to control numerals and characters displayed by an external liquid crystal display device (not shown); Com0 to 6 are matrix electrode 7 for display
Terminals for outputting the control outputs of the common electrodes, and Seg0 to Seg6 are terminals for outputting the control outputs of the seven segment electrodes. These terminals are collectively shown as input / output terminals 35. Note that the block diagram of the entire circuit including the RTC, LCD, and other circuits and the layout on the circuit board are omitted because they are highly arbitrary depending on the electronic information device.

Next, a reference example will be described. This is also one of the prior arts of the present invention, but since it is considered that not all have been publicized, the name of the conventional example is avoided. In the reference example, RTC and LCD are standardized and standardized as individual functional component circuits, respectively, with the aim of reducing the cost of electronic information equipment by standardizing circuit specifications and eliminating the need for new design steps. Used in combination. That is, each single-function circuit is mounted on each single small circuit board and packaged (for example, the whole is sealed with resin to stabilize the environment)
The standardized general-purpose shape and specifications were provided, and this was used as a unitized single-function component circuit.

A reference example will be described with reference to the drawings. 4A and 4B are schematic diagrams showing the connection between single-function circuit components and peripheral devices often used in electronic information equipment. FIG. 4A shows an RTC 1 and an external CPU 16, and FIG. 4B shows an LCD 3 and an external liquid crystal display. It relates to the element 36. The external peripheral device corresponding to each single-function circuit component includes an input / output terminal 15,
It is connected by a communication line from 35.

The main part of each component circuit is formed as an IC similarly to the conventional example shown in FIG. 3, and necessary external elements (their component numbers are the same as those of the conventional example) and small circuit boards 10 and 30. On the circuit board 10, 30, the side where the circuit element is provided is filled with a sealing resin to a depth at which the circuit element is buried. Further, the circuit board includes a power supply 5 and a plurality of input / output terminals 15 and 35 in a peripheral portion. However, in each circuit, a bare chip IC is directly die-bonded on the circuit boards 10 and 30, and is connected to a pattern on the board by wire bonding. Since the IC is protected by the above sealing resin,
It is not necessary to use a flat package IC as in the conventional example.

As a practical example of a single-function component circuit in the reference example, there is a patent application of Japanese Patent Application No. 9-193352 for RTC.

When an electronic circuit of an actual electronic information device including the two functional circuits of RTC and LCD is constructed,
Each of the standardized single-function circuit components is regarded as a single component, and the necessary single-function circuit components are combined.
It was mounted on a larger circuit board together with other circuit components to form a circuit of an electronic information device. For example, FIG. 5 is a plan view of a part of an electronic circuit in which two single-function circuit components of an RTC 1 and an LCD 3 are mounted on a large circuit board 4 with a common power supply. (Although not shown, other circuits may be further mounted on the large circuit board 4.) It is believed that the configuration of such an electronic circuit is not yet known.

[0013]

First, the length of the conventional example and the reference example will be grasped. In the conventional example, since the electronic circuit can be comprehensively designed, the degree of achievement of high-density circuit and, therefore, downsizing of the device is high. However, the entire circuit design is individually performed by the device manufacturer for each information device, which not only increases the initial design turn, but also the specifications based on the needs of the device users and the enhancement of product functions. It is inevitable that the number of steps and costs required for the design change due to the change and diversification become longer, which is disadvantageous in pursuing quick commercialization.

In the reference example, a component maker supplies a single-function component circuit such as an RTC or an LCD to an information device maker (a user of the circuit component) as a standardized functional circuit component. Parts manufacturers produce and supply large quantities as standard products that can be used in common for various types of information equipment, and their users only have to handle them as standardized functional circuit components in their designs.

In this case, the overall circuit manufacturing process seems to be complicated because the board processing and mounting processes are performed by both the component maker and the device maker. The change in the circuit part of (1), which is caused by the equipment maker side), is rather reduced because it does not touch the inside of each single-function circuit part, and the overall manufacturing cost of the electronic circuit is also reduced by the part maker. It is rather advantageous because of the streamlining effect on the part. In addition, there is also an advantage that the reliability of the above circuits supplied as functional components is improved by resin molding in advance for each component circuit.

On the other hand, components (ICs) inside each functional circuit component
And external elements) are mounted on an independent small circuit board, the outline of which is required to have a geometrically simple shape (often rectangular). Since the minimum thickness of the resin must be ensured, it is necessary to provide a sufficient space in the peripheral portion of the functional circuit and in the vicinity thereof. However, the space occupied by the IC alone on the substrate can be smaller than that of the conventional flat package IC because the bare chip is directly mounted. Therefore, the size cannot be simply discussed by comparing the total occupied area (or volume) of each functional circuit portion. However, in this reference example, in terms of miniaturization of the overall circuit, there is a slight disadvantage compared to the conventional example. It is possible that

SUMMARY OF THE INVENTION An object of the present invention is to provide a multifunctional circuit capable of achieving a more balanced overall reduction in the size, man-hours, and cost of electronic information equipment, and a reduction in the number of steps for new designs or design changes and cost reduction. It is to provide a component and an electronic information device using the same.

[0018]

In order to solve the above problems, the present invention has the following arrangement. (1) A composite circuit suitable for electronic information equipment having at least a real-time clock circuit (RTC) for generating data such as time and a liquid crystal driver (LCD) for controlling and driving a liquid crystal display device. The clock circuit and the liquid crystal driver are mounted on a single composite circuit board provided with input / output terminals and a power supply terminal for each circuit, and ICs and components constituting each circuit are mounted and sealed in the same package. A multi-function circuit component having the functions of a real-time clock circuit and a liquid crystal driver, wherein the multi-function circuit component is a single circuit component. (2) The composite circuit board includes an SMD terminal group.

(3) A real-time clock circuit (RTC) for generating data such as time and a liquid crystal driver (LCD) for controlling and driving a liquid crystal display device are provided with input / output terminals and a power supply terminal for each circuit. A multi-function circuit component having the functions of a real-time clock circuit and a liquid crystal driver as a single circuit component by mounting ICs and components constituting the respective circuits mounted on a single small circuit board and enclosing them in the same package. Electronic information equipment characterized by using.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a perspective view of an embodiment of a multifunctional circuit component according to the present invention, FIG. 2A is a plan view thereof (excluding a sealing resin), and FIG. It is a block diagram of a circuit. Components common to the conventional example and the reference example are denoted by the same symbols. One single-function circuit for each of RTC and LCD is provided on one composite circuit board 61 with power supply terminals VDD,
They are arranged with a common VSS.

The composite circuit board 61 has several to several
A substrate material in which copper foil is adhered to both surfaces of a large-sized epoxy resin containing glass or the like corresponding to 00 or more pieces is cut at the final stage of production and separated into individual pieces. On the upper surface, ICs 11 and 31 constituting two single-function circuits and a quartz oscillator 1
2. The capacitors 13, 33, 34, the resistor 32, etc. are arranged in consideration of the overall occupied area being reduced. Each I
C is connected to a printed wiring pattern (not shown) by wire bonding similarly to the above-mentioned reference example. The thick quartz oscillator 12 is half-buried in the counterbore portion of the substrate.

The input / output terminals 1 of each single-function circuit
5, 35 and a power supply terminal are provided. This consists of gold plating on the inner surface of the through hole provided in the large-sized substrate material and a small area gold pattern on the lower surface connected thereto. If the large-sized substrate material is divided vertically and horizontally on a vertical plane passing through the center of the through hole, the inner surface electrode of the through hole is exposed in a concave shape, and becomes a side electrode with a small area lower surface electrode. The side / bottom electrodes serve as SMD electrodes for mounting the composite circuit board 61 on a mother board of an integrated circuit of an electronic information device.

The side electrodes need not be concave, and may be formed by another known manufacturing method (e.g., forming a through-hole as an elongated hole and forming an electrode film in stripes on the inner surface thereof, or forming a side electrode after dividing the plane). Can be formed on the flat surface. Reference numeral 62 denotes a sealing resin, which is injected into the upper surface of the large substrate when the mounting of the circuit element is completed.
Seal the circuit. Thereafter, it is cut and separated together with the multifunction circuit. It should be noted that the upper surface side for injecting the resin is closed with a film or the like so that the resin does not flow into the through holes during molding. This method is also known.

A description will be given of a modification of the embodiment of the present invention. (1) The SMD terminal is not always provided only on the peripheral portion of the board of the multifunction circuit component. A terminal connected to a circuit on the upper surface by a through hole may be provided at an arbitrary position on the lower surface of the substrate.

(2) By mixing magnetic ferrite powder in the sealing resin, it is possible to provide a magnetic shielding effect for preventing generation or influence of noise.

(3) The multi-function circuit component is housed in a metal or conductive case, or metal plating or conductive coating is applied to the outer surface of the sealing resin (the terminal portion is exposed from the case or coating). ), An electrostatic shielding effect can also be provided.

(4) Two ICs of two kinds of circuits to be combined
May be integrated on the same semiconductor chip. (5) The connection of the IC is not limited to wire bonding. For example, face-down flip chip bonding may be used.

[0028]

According to the present invention, the two circuit elements of the RTC and the LCD, for which the standard configuration has been almost established, are mounted on the same substrate and are made into a single component as a multifunctional circuit component. Having. (1) Since multifunctional circuit components can be standardized and supplied,
The functional circuits can be significantly reduced in cost due to rationalization, standardization effects and mass production effects.

(2) Compared to the conventional example in which each is incorporated as a separate circuit in the integrated circuit, the number of components is substantially reduced, the wiring of the integrated electronic circuit is simplified, and a new design or design change of the integrated circuit is easy. And the time and cost for doing so are significantly reduced.

(3) In the manufacture of a comprehensive electronic circuit for electronic information equipment, the equipment can be smaller and the required time can be reduced. If the SMD terminal is provided in the multi-function circuit component, it can be mounted simultaneously with other components, and the effect on manufacturing is further enhanced.

(4) Compared with the reference example in which each of the above circuit elements is incorporated into a comprehensive circuit as a single functional component circuit, the standardization and rationalization have been further advanced, and the actual number of components has been reduced. The wiring of the electronic circuit is also simplified, and the new design and the design change of the integrated circuit are relatively easily performed, so that the time and cost for it are further reduced.

(5) The multifunctional component circuit of the present invention can be arranged more rationally than the single functional component circuit of the reference example, and can be used for terminal space, sealing resin space, and circuit. Since any invalid space in the arrangement such as the periphery can be reduced, the circuit of the multifunction part of the electronic information device becomes smaller than the reference example. Furthermore, since the space occupied by the IC can be reduced by mounting it on a bare chip, the size can be reduced to a size almost comparable to the conventional example.

(6) The resin-molded composite function circuit component has the advantage of improving the reliability of the entire circuit component. (7) Further, by mixing magnetic powder into the sealing resin or covering the sealing resin with a conductive case or the like, it is possible to prevent the occurrence of malfunction due to noise.

(8) Generally speaking, according to the present invention,
Various effects such as downsizing, reduction of man-hours, cost reduction, new design or design change and cost reduction of electronic information equipment, and improvement of reliability can be achieved in a well-balanced manner. Since the RTC and the LCD are closely related to each other (for example, the data of the RTC is displayed on the LCD) or are often used at the same time, the RTC and the LCD are integrated into one circuit component. ) Has been greatly improved.

[Brief description of the drawings]

FIG. 1 is a perspective view of a composite circuit component which is an example of an embodiment of the present invention.

2A and 2B show a composite circuit component as an example of an embodiment of the present invention, wherein FIG. 2A is a plan view and FIG. 2B is a block diagram.

3A and 3B are block diagrams of a conventional example, a reference example, and respective element circuits related to the present invention, wherein FIG. 3A is an RTC, and FIG.
Is shown.

4A and 4B are schematic diagrams showing each single-function circuit component and its peripheral device of a reference example, where FIG. 4A is an RTC and a CPU, and FIG.
1 shows a CD and a liquid crystal display device.

FIG. 5 is a plan view of a part of a large-sized circuit board on which a single-function circuit component of a reference example is mounted.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 RTC 10 Circuit board 11 RTC IC 12 Crystal oscillator 13 Capacitor 15 I / O terminal 16 CPU 3 LCD 30 Circuit board 31 LCD IC 32 Oscillation resistor 33 Oscillation capacitor 34 Contrast adjustment capacitor 35 I / O terminal 36 Liquid crystal display Apparatus 4 Large circuit board 5 Power supply 61 Composite circuit board 62 Sealing resin

Claims (3)

[Claims] 1. A composite circuit suitable for an electronic information device having at least a real-time clock circuit (RTC) for generating data such as time and a liquid crystal driver (LCD) for controlling and driving a liquid crystal display device. The clock circuit and the liquid crystal driver are mounted on a single composite circuit board provided with input / output terminals and a power supply terminal for each circuit, and ICs and components constituting each circuit are mounted and sealed in the same package. A multi-function circuit component having the functions of a real-time clock circuit and a liquid crystal driver, wherein the multi-function circuit component is a single circuit component. 2. The multifunction circuit component according to claim 1, wherein said multifunction circuit board includes a group of terminals for SMD. 3. A real-time clock circuit (RTC) for generating data such as time and a liquid crystal driver (LCD) for controlling and driving a liquid crystal display device, comprising one input / output terminal and a power supply terminal for each circuit. A multi-function circuit component having the functions of a real-time clock circuit and a liquid crystal driver as a single circuit component by mounting ICs and components constituting each of the above-described circuits mounted on a small circuit board, and enclosing them in the same package. Electronic information equipment characterized by using.