JP2005079619A - Oscillator - Google Patents

Abstract

An object of the present invention is to eliminate defects caused by soldering, to effectively use a mounting area of a circuit board and to increase a mounting density.
In a crystal oscillator 1, a cavity 21 is formed in the center of a circuit board 2, and an oscillation unit 3 including a feedback amplifier is mounted in the cavity 21. Soldering is performed in order to connect the electrodes provided on each of the crystal unit 4 and the other constituent members 5 and the electrodes of the circuit board 2 corresponding to these electrodes. The component member 5 is mounted on the circuit board 2. Further, the arrangement of the crystal unit 4 and the other component members 5 is designed so that the loop distance of the circuit 6 is short and the interval between the other component members 5 is wide. The vibrator 4 and other constituent members 5 are mounted. In addition, the crystal unit 4 and the other constituent members 5 are connected in series to the oscillation unit 3 to form a circuit 6.
[Selection] Figure 1

Description

  The present invention relates to an oscillator, and more particularly, to an arrangement of members mounted on a circuit board of the oscillator.

  In recent years, portable electronic devices, such as mobile phones, are becoming lighter, thinner, and smaller. Therefore, along with this, miniaturization of a crystal oscillator, which is one of the components of a cellular phone, has been developed (see, for example, Patent Document 1).

  For example, as shown in FIG. 8, a conventional crystal oscillator 8 includes, on a circuit board 81, a semiconductor integrated circuit 82 such as an IC chip that is an oscillation unit, a crystal resonator 83, and other components 84 (841,. 842, 843, 844, 845, 846, 847). These crystal resonators 83 and other constituent members 84 are connected to the semiconductor integrated circuit 82 to form a circuit.

  By the way, in this crystal oscillator 8, soldering is performed when another constituent member 84 is mounted on the circuit board 81. At the time of this soldering, for example, as shown in FIG. 8, when another component member 84 is mounted on the circuit board 81 by soldering, the soldered portions of the other component members 844, 845, 846, and 847 are close to each other. . As described above, when the soldering portion is at a short distance, there is a possibility that problems such as a solder bridge, displacement of the constituent members accompanying it, and standing of other constituent members 84 may occur, resulting in poor yield.

Further, regarding the positional relationship among the semiconductor integrated circuit 82, which is an oscillating portion mounted on the circuit board 81, the crystal resonator 83, and the other constituent members 84, for example, an arrangement as shown in Patent Document 1 described below, for example. There is a relationship. In the crystal oscillator 9 (see FIG. 9) disclosed in the cited document 1, the crystal resonator 91 is a semiconductor integrated circuit (IC chip) 92 and an electronic component 93 (931, 932, 933, 934) which is another constituent member. It is arranged in parallel with.
Japanese Patent Laid-Open No. 7-212130

  However, when the arrangement relationship among the crystal resonator 91, the IC chip 92, and the electronic component 93 disclosed in Patent Document 1 described above is applied to the circuit board 81 shown in FIG. 8, as shown in FIG. The IC chip 92 is mounted in the vicinity of the end face of the circuit board 81 although it is not mounted adjacently in a concentrated manner.

  Therefore, in the case where the arrangement relationship among the crystal resonator 91, the IC chip 92, and the electronic component 93 disclosed in Patent Document 1 described above is applied to the circuit board 81 shown in FIG. 8, for example, the number of the electronic components 93 is increased. In this case, the electronic components 93 are intensively adjacent to each other, and a problem such as the crystal oscillator 8 shown in FIG. 9 is mounted on the circuit board 81 shown in FIG. 8, the mounting density of the electronic parts 93 on the circuit board 81 is increased, which is currently required. It is difficult to realize a thin and small size. Further, since the IC chip 92 is mounted in the vicinity of the end face of the circuit board 81, the mounting area of the circuit board 81 such as mounting the electronic component 93 in the area between the IC chip 92 and the end face of the circuit board 81 is effective. It cannot be used.

  SUMMARY OF THE INVENTION In order to solve the above-described problems, an object of the present invention is to provide a small oscillator that eliminates the problems caused by soldering, effectively uses the mounting area of the circuit board, and increases the mounting density.

  In order to achieve the above object, an oscillator according to the present invention includes an oscillation unit including a feedback amplifier, a transducer, and a plurality of other components mounted on a circuit board, and the oscillation unit includes a plurality of other components. An oscillator in which a loop-like circuit is configured by being connected to a component, wherein the oscillator is mounted in the center of the circuit board, and the vibrator and the other are looped around the oscillator A component is mounted, and the arrangement of the vibrator and the other component is designed so that the loop distance of the circuit is short and the interval between the plurality of other components is widened. To do.

  According to the present invention, the oscillation unit including the feedback amplifier is mounted in the center of the circuit board, and the vibrator and the plurality of other components are mounted along the periphery of the oscillation unit. The layout of the circuit is designed so that the loop distance of the circuit is short and the interval between a plurality of other components is widened. It is possible to eliminate problems due to soldering for mounting the constituent members and vibrators on the circuit board, that is, problems such as misalignment of solder bridge parts. As a result, it is possible to effectively use the mounting area of the circuit board and increase the mounting density. For example, according to the oscillator according to the present invention, it is possible to reduce the size of the oscillator by reducing the area of the circuit board. Alternatively, it is possible to improve the performance of the oscillator by mounting many other components in the mounting area of the mountable circuit board while keeping the size of the circuit board as it is. In addition, since the vibrator is mounted on a circuit board that is on the same plane as other components, the thickness of the oscillator can be reduced. Further, since the loop distance of the circuit is short and the interval between the other components is wide, it is preferable for eliminating stray capacitance.

  In the above configuration, a cavity may be formed in the circuit board, and the oscillation unit may be mounted in the cavity.

  In this case, since the oscillating unit is mounted in the cavity, the space above the cavity in which the oscillating unit is mounted is in a hollow state, and it is easy to solder each component member including the vibrator around the cavity in which the oscillating unit is mounted without trouble. Can be performed.

  Specifically, in the above configuration, the uppermost end of the oscillating unit mounted in the cavity may be positioned below the uppermost end of the wall surface of the cavity.

  In this case, since the uppermost end of the oscillation part mounted in the cavity is located below the uppermost end of the wall surface of the cavity, the space above the cavity where the oscillation part is reliably mounted is in a hollow state, that is, the vibrator and other configurations The oscillating part is not arranged on the same plane as the member, and it is preferable to easily solder each component member including the vibrator around the cavity on which the oscillating part is mounted without trouble. In addition, it is possible to eliminate problems such as interference between the oscillating portion and each component including the vibrator at the same time.

  Furthermore, in the above configuration, the oscillating portion may be molded with an insulator such as a resin.

  In this case, even when the oscillation unit is connected to the circuit board by wire bonding or the like, there is a problem due to solder flowing out when connecting the vibrator or other components to the circuit board, or a wire due to contact with an external component. It becomes possible to prevent the cutting of the bonding and the destruction of the oscillation part.

  Specifically, in the above configuration, it is preferable that at least one of a temperature compensation member, a frequency adjustment member, and a voltage control member is included in the other component members. The number of the temperature compensation member, frequency adjustment member, and voltage control member to be mounted can be arbitrarily set.

  In the above configuration, the vibrator and the other constituent members may be connected in series to the oscillation unit.

  In this case, the vibrator and other constituent members are mounted along the periphery of the oscillating portion and are connected in series to the oscillating portion, so that each constituent member functions independently and the loop distance of the circuit is shortened. Thus, it becomes possible to eliminate the malfunction of the circuit due to the influence of the external environment that is likely to occur as the circuit loop distance increases. In addition, since the vibrator and other components are connected in series, circuit design is facilitated.

  According to the oscillator according to the present invention, problems due to soldering can be eliminated, the mounting area of the circuit board can be used effectively, and the mounting density can be increased.

  Specifically, according to the oscillator according to the present invention, the oscillating unit including the feedback amplifier is mounted in the center of the circuit board, and the vibrator and a plurality of other components are mounted along the periphery of the oscillating unit. The arrangement of the vibrator and other structural members is designed so that the loop distance of the circuit is short and the interval between a plurality of other structural members is wide. By avoiding this, it is possible to eliminate problems due to soldering for mounting other components and vibrators on the circuit board, that is, problems such as misalignment of solder bridge parts. As a result, the mounting area of the circuit board can be effectively used and the mounting density can be increased. Further, since the vibrator is mounted on a circuit board that is on the same plane as the other constituent members, the thickness of the oscillator can be reduced. Further, since the loop distance of the circuit is short and the interval between the other components is wide, it is preferable for eliminating stray capacitance.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following embodiments, the present invention is applied to a crystal oscillator as an oscillator. However, the present invention is not limited to this. For example, an LC oscillator, a ceramic vibrator, a SAW filter, etc. Also good.

  In the crystal oscillator 1 according to the present embodiment, as shown in FIG. 1, an oscillation unit 3 including a feedback amplifier, a crystal unit 4, and other components 5 (L 1, C 1, C 2, C 3, DV, R1, R2, see below).

  A cavity 21 is formed in the center of the circuit board 2, and the oscillator 3 is mounted in the cavity 21 by being molded with a resin M (see FIG. 2). In mounting the oscillating unit 3 in the cavity 21, the uppermost end of the oscillating unit 3 mounted in the cavity 21 is positioned below the uppermost end of the wall surface of the cavity 21. In the present embodiment, as shown in FIG. 2, the uppermost end of the oscillation unit 3 mounted in the cavity 21 is lower than the uppermost end of the wall surface of the cavity 21. That is, the oscillation unit 3 is not arranged on the same plane as the crystal unit 4 and the other constituent members 5.

  Electrodes (not shown) provided on the crystal unit 4 and other constituent members 5 (L1, C1, C2, C3, DV, R1, R2) and electrodes of the circuit board 2 corresponding to these electrodes (not shown) The crystal resonator 4 and the other constituent members 5 (L1, C1, C2, C3, DV, R1, R2) are mounted on the circuit board 2 by this. The In addition, the soldering part of the other structural member 5 in this embodiment is an example of another structural member (trimmer capacitor circuit C3 (see below)), and both longitudinal ends of the other structural member C3 shown in FIG. Surfaces 5a and 5b.

  Further, the arrangement of the crystal unit 4 and the other constituent members 5 (L1, C1, C2, C3, DV, R1, R2) is such that the loop distance of the circuit 6 (see below) is short and the other constituent members 5 are arranged. (L1, C1, C2, C3, DV, R1, R2) are designed to be wide, and as shown in FIG. 1, the crystal unit 4 and other components 5 along the periphery of the oscillation unit 3 are designed. And are implemented.

  In this crystal oscillator 1, a crystal unit 4 and other components 5 are connected to the oscillation unit 3 to form a loop-shaped (single) circuit 6. In this circuit 6, as shown in FIG. 3, a crystal resonator 4 and other constituent members 5 (L1, C1, C2, C3, DV, R1, R2) are connected in series to an oscillation circuit 31 (see below). It becomes.

  The oscillating unit 3 formed of a feedback amplifier includes an oscillating circuit 31 using bipolar transistors as shown in FIG.

  The other component 5 is comprised from the frequency adjustment member 51 (511, 512, C3) and the voltage control member 52 (DV, R).

  The frequency adjustment member 51 includes an LR circuit 511 for enlarging the frequency variable amount of the crystal resonator 4, a capacitor frequency adjustment circuit 512 for finely adjusting the frequency of the crystal resonator 4, and a trimmer capacitor circuit C3 (FIG. 5 ( c) see).

  As shown in FIG. 5D, the LR circuit 511 is formed by connecting an extension coil L1 and a resistor R1 for preventing self-excited oscillation in parallel.

  As shown in FIG. 5B, the capacitor frequency adjusting circuit 512 includes a first capacitor C1 and a second capacitor C2 connected in parallel. Among these, the second capacitor C2 can be removed, and the frequency of the crystal resonator 4 is finely adjusted by changing the capacitance of the second capacitor C2.

  The voltage control member 52 (see FIG. 5 (f)) is connected to the ground with the varicap diode DV connected in series (via the resistor R3 in FIG. 5 (f)), and controls the voltage of the crystal oscillator 1. A control voltage unit (not shown) is connected to the port 61 of the circuit 6 via the resistor R2.

  The oscillation circuit 31 using the above bipolar transistors, the crystal resonator 4, the LR circuit 511, the capacitor frequency adjusting circuit 512, the trimmer capacitor circuit C3, the inductor L1, the resistor R1, the first capacitor C1, The circuit 6 of the crystal oscillator 1 shown in FIG. 6 is configured by the two capacitors C2, the varicap diode DV, and the resistor R2.

  As described above, according to the crystal oscillator 1 according to the present invention, the oscillating unit 3 is mounted at the center of the circuit board 2, and the crystal unit 4 and other constituent members 5 (frequency) are arranged along the periphery of the oscillating unit 3. The adjustment member 51 and the voltage control member 52) are mounted, and the arrangement of the other component members 5 and the crystal resonator 4 is such that the loop distance of the circuit 6 is short, and each component (L1, C1) of the other component member 5 is arranged. , C2, C3, DV, R1, R2) are designed to be wide, so that the other constituent members 5 and the crystal unit 4 are avoided from being intensively adjacent to each other. Problems due to soldering for mounting the crystal unit 4 on the circuit board 2 can be eliminated, that is, problems such as misalignment of solder bridge parts can be eliminated. As a result, the mounting area of the circuit board 2 can be effectively used and the mounting density can be increased. For example, the area of the circuit board 2 can be reduced to reduce the size of the crystal oscillator 1. Further, since the loop distance of the circuit 6 is short and the interval between the other constituent members 5 is wide, it is preferable for eliminating stray capacitance.

  Alternatively, many other components are mounted in the mounting area of the mountable circuit board 2 in the state where the size of the circuit board 2 is kept the same as that used in the present embodiment (see FIG. 1). Thus, the performance of the oscillator can be improved.

  Further, since the crystal unit 4 is mounted on the circuit board 2 which is on the same plane as the other component members 5, the thickness of the crystal oscillator 1 can be reduced.

  Further, since the oscillating unit 3 is mounted in the cavity 21, the space above the cavity 21 in which the oscillating unit 3 is mounted is in a hollow state, and other constituent members 5 around the cavity 21 in which the oscillating unit 3 is mounted are soldered. It can be done easily without any problems. In particular, in the present embodiment, since the uppermost end of the oscillating unit 3 mounted in the cavity 21 is lower than the uppermost end of the wall surface of the cavity 21, the oscillating unit is located on the same plane as the crystal unit 4 and the other component members 5. 3 is not disposed at all, and it is preferable to easily solder the crystal resonator 4 and the constituent members 5 around the cavity 21 in which the oscillating unit 3 is mounted without any trouble. In addition, problems such as interference between the oscillating portion 3 and the crystal resonator 1 and other constituent members 5 can be eliminated at the same time.

  Further, since the oscillating unit 3 is molded with an insulator such as a resin, even when the oscillating unit 3 is connected to the circuit board 2 by wire bonding or the like, the crystal unit 4 and other components 5 It is preferable for preventing problems caused by the flow of solder when connected to the circuit board 2, cutting of wire bonding due to contact with external components, and destruction of the oscillation unit 3 (oscillation circuit 31).

  In addition, since the crystal unit 4 and the other constituent members 5 are connected in series to the oscillation unit 3, each constituent member (the crystal unit 4, the frequency adjusting member 51, and the voltage control member 52) functions independently. At the same time, the loop distance of the circuit 6 can be shortened. For this reason, it is possible to eliminate the problem of the circuit due to the influence of the external environment that is likely to occur when the loop distance of the circuit 6 is increased.

  Further, since the crystal unit 4 and the other constituent members 5 are connected in series, circuit design is facilitated.

  In this embodiment, the cavity 21 is formed at the center of the circuit board 2 and the oscillating unit 3 is mounted in the cavity 21. However, the present invention is not limited to this, and the oscillating unit 3 and other components are used. If the state that can be connected to 5 other than wiring is prevented, for example, the oscillation unit 3 may be mounted at the center of the circuit board 2 and the mounted oscillation unit may be molded with resin.

  Further, the center of the circuit board 2 in the present embodiment is mounted at the mounting position shown in FIG. 1 if the oscillating unit 3 is mounted and another component 5 or crystal resonator 4 can be mounted around the oscillating unit 3. For example, the oscillating unit 3 may be mounted on one end face of the circuit board 2 at a position shifted from the center (near the center).

  Moreover, in this Embodiment, since the removal of the other structural member distribute | arranged to the corner part of the circuit board 2 is easy, as an example, although the 2nd capacitor | condenser C2 is removable among the other structural members 5. However, the present invention is not limited to this, and other constituent members may be used.

  Further, in the present embodiment, the oscillation unit 3 composed of a feedback amplifier is composed of the oscillation circuit 31 using a bipolar transistor. However, the present invention is not limited to this, and a circuit that returns a part of the output signal of the circuit 6 to the input. If so, for example, a C-MOS inverter as shown in FIG. 7 may be used.

  In the present embodiment, the other component members 5 include the frequency adjustment member 51 and the voltage control member 52, but are not limited to this, and the frequency adjustment member 51 and the voltage control member 52 are not limited thereto. It is preferable that 1 or more types are used. Further, although one frequency adjusting member 51 and one voltage control member 52 are used, the number is not limited to one, and the number of each may be set arbitrarily. Further, it is also preferable that the other component 5 includes a temperature compensation circuit T as shown in FIG. 5E. Further, as shown in FIG. Other components such as a control bypass capacitor C6 may be included. FIG. 5A is a capacitor frequency adjustment circuit diagram for roughly adjusting the frequency of the crystal unit 4.

  In the present embodiment, as shown in FIG. 2, the uppermost end of the oscillating unit 3 mounted in the cavity 21 is lower than the uppermost end of the wall surface of the cavity 21, but the present invention is not limited to this. It is only necessary that the uppermost end of the oscillation unit 3 mounted on is located below the uppermost end of the wall surface of the cavity 21. That is, for example, if the oscillating unit 3 does not protrude from the cavity 21, the uppermost end of the oscillating unit 3 mounted in the cavity 21 may be the same as the uppermost end of the wall surface of the cavity 21.

  In the present embodiment, as a preferred example, as shown in FIG. 2, the uppermost end of the resin M molded with the oscillating portion 3 is formed on the same plane as the circuit board 2. However, the present invention is not limited to this. Instead, the resin M may rise from the plane of the circuit board 2.

  The present invention can be applied not only to a crystal oscillator but also to other oscillators.

FIG. 4 is a layout diagram showing the layout of members on a circuit board of the crystal oscillator according to the present embodiment. It is the sectional view on the AA line shown in FIG. 1 of the circuit board of the crystal oscillator which concerns on this Embodiment. It is a block diagram of the circuit of the crystal oscillator based on this Embodiment. It is a circuit diagram showing an oscillation circuit of an oscillation part provided in the crystal oscillator according to the present embodiment. (A) is a capacitor frequency adjustment circuit diagram for coarse adjustment which is one of the circuit configurations of the crystal oscillator according to the present embodiment, (b) is a capacitor frequency adjustment circuit diagram for fine adjustment, (C) is a circuit diagram of a trimmer capacitor circuit, (d) is a circuit diagram of an LR circuit, (e) is a circuit diagram of a temperature compensation circuit, and (f) is a voltage control member. It is a circuit diagram. It is a circuit diagram showing a circuit of a crystal oscillator concerning this embodiment. It is the circuit diagram which showed the other oscillation circuit of the oscillation part provided in the crystal oscillator which concerns on this Embodiment. It is the layout which showed arrangement | positioning of each member to the circuit board of the conventional crystal oscillator. FIG. 9 is a layout diagram showing the layout of each member of a conventional crystal oscillator different from the crystal oscillator shown in FIG. 8.

Explanation of symbols

1 Crystal oscillator
2 Circuit board 21 Cavity 3 Oscillator 4 Crystal resonator
5 Other components 51 Frequency adjustment member 52 Voltage control member 6 Circuit T Temperature compensation circuit (temperature compensation member)

Claims (6)

An oscillation unit composed of a feedback amplifier, a vibrator, and a plurality of other constituent members are mounted on a circuit board, and a vibrator and a plurality of other constituent members are connected to the oscillation unit to form a loop-shaped circuit. An oscillator,
The oscillator is mounted at the center of the circuit board, and the vibrator and the other constituent members are mounted along the periphery of the oscillator.
The oscillator and the other constituent members are arranged so that the loop distance of the circuit is short and the intervals between the plurality of other constituent members are widened. The oscillator according to claim 1, wherein
An oscillator, wherein a cavity is formed in the circuit board, and the oscillation unit is mounted in the cavity. The oscillator according to claim 2, wherein
An oscillator, wherein an uppermost end of the oscillating portion mounted in the cavity is positioned below an uppermost end of a wall surface of the cavity. The oscillator according to any one of claims 1 to 3,
The oscillator is molded with an insulator. The oscillator according to any one of claims 1 to 4,
The oscillator includes at least one of a temperature compensation member, a frequency adjustment member, and a voltage control member. The oscillator according to any one of claims 1 to 5,
The oscillator and the other constituent members are connected in series to the oscillation unit.

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