KR20000011723A - Electronic circuit unit - Google Patents

Abstract

PURPOSE: An electronic circuit unit is provided to be formed by using a multi-layer substrate, and to be used by installing in the mother substrate improving the launching frequency characteristics. CONSTITUTION: The electronic circuit unit comprises: a collector of a launching transistor(1) grounded by a direct current retardation condenser(2) in a high frequency; return condensers(3, 4) contacted between a base and an emitter, and between the emitter and a ground; the emitter contacted by a direct current circuit with an emitter bias resistant(5) and a parallel resonance circuit(6); a variable reactance circuit(7) contacted between the base and the ground; the variable reactance circuit(7) contacted in a parallel against the return condenser(3, 4) contacted in a series, and to operate as an inductance element in equivalent in the launching frequency.

Description

Electronic circuit unit {ELECTRONIC CIRCUIT UNIT}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic circuit unit, such as an oscillator, which is constructed using a multilayer board and is installed and used on a mother board.

A conventional electronic circuit unit will be described as an example of an oscillator. The circuit of the conventional oscillator is shown in FIG. This oscillation circuit is a collector-ground oscillation circuit, in which the collector of the oscillation transistor 51 to which the power supply voltage E is applied is grounded at high frequency by a DC blocking capacitor 52, and is connected between the base and the emitter. , And the feedback capacitors 53 and 54 are connected between the emitter and the ground, respectively. The variable reactance circuit 55 is connected between the base and the ground. The variable reactance circuit 55 is connected in parallel to the feedback capacitors 53 and 54 connected in series, and acts as an inductance element equivalently at the oscillation frequency.

The variable reactance circuit 55 is composed of a crab capacitor 56, a first micro strip line 57, a frequency correction capacitor 58, and a varactor diode 59, and the crab capacitor 56 and the first micro strip. The line 57 is connected in series, and the frequency correcting capacitor 58 and the varactor diode 59 are connected in series. Then, the frequency correcting capacitor 58 and the varactor diode 59 connected in series are connected in parallel to the first micro stripline 57. One end of the crab capacitor 56 is connected to the base of the oscillation transistor 51, and one end of the first micro stripline 57 and the anode of the varactor diode 59 are grounded together.

The control voltage V for changing the oscillation frequency is applied to the cathode of the varactor diode 59 via the second micro stripline 60 used as the choke inductor.

Fig. 7 shows a cross-sectional view of main parts of an oscillator in which the oscillator circuit is composed of a multi-layer substrate 61. Circuit components such as the oscillation transistor 51, the DC blocking capacitor 52, the feedback capacitors 53 and 54, and the frequency correction capacitor 55c are placed on the upper surface of the multilayer substrate 61 (FIG. 7 frequency correction capacitor). (58) only). In addition, the first micro stripline 57 and the second micro strip line 60 are formed of the inner conductor layer 6la, thereby miniaturizing the oscillator. Therefore, for example, a first through hole (hereinafter referred to as a through hole) 62 is formed for the connection between the first micro strip line 57 and the frequency correction capacitor 58. Similarly, a second through hole 63 is formed for the connection between the second micro strip line 60 and the frequency correction capacitor 58. Connection points A and B in FIG. 5 indicate positions at which the first through hole 62 and the second through hole 63 are formed.

In the first and second through holes 62 and 63, conductor walls 62a and 63a are formed by means of plating or the like. Moreover, resin 64 and 64 are filled in the inside, and the electrodes 65 and 66 and the electrodes 67 and 68 are formed in the both ends, respectively. Accordingly, the electrodes 65 and 66 and the conductor wall 62a are interconnected in the first through hole 62, and the electrodes 67 and 68 and the conductor wall 63a are connected to each other in the second through hole 63. . These through holes 62 and 63 are often referred to as chip-on through holes and are used for high density installation.

Then, the electrode portions 58a, 58b of the frequency correction capacitor 58 are placed on the upper electrodes 65, 67 of the multilayer substrate 61, and the electrode portions 58a, the electrodes 65, and the electrode portions ( 58b) and electrode 67 are connected to each other by solders 69 and 69, respectively. The electrodes 66 and 68 on the lower surface side of the multilayer substrate 61 are not connected to other circuits. The first micro stripline 57 and the conductor wall 62a are connected, and the second micro strip line 60 and the conductor wall 63a are connected. Thereby, the frequency correction capacitor 58, the first micro stripline 57 and the second micro strip line 60 are connected.

On the other hand, the lower surface of the multilayer substrate 61 is provided with a conductor layer 61b of an outer layer facing the first microstripline 57 and the second microstripline 60, and the conductor layer 61b is provided. Grounded. As a result, the first micro stripline 57 and the second micro strip line 60 have a predetermined impedance.

The impedance of the first micro strip line 57 is adjusted to have a predetermined oscillation frequency by a predetermined control voltage V applied to the varactor diode 59. This adjustment is called trimming and is performed by, for example, applying a cutting depth to the first micro stripline 57.

The oscillator configured as described above is placed on a mother substrate (not shown) constituting a transceiver or the like and used as a local oscillator or a carrier oscillator of the transceiver. At that time, the lower surface of the multilayer substrate 61, that is, the conductor layer 61b, is placed so as to face the upper surface of the mother substrate. On the other hand, a grounding conductor (not shown) is provided on the upper surface of the mother substrate. Therefore, in the state where the oscillator is placed on the mother substrate, the first through hole 62 and the second through hole formed in the multilayer board 61 ( Electrodes 66, 68 formed on the substrate 63 and the ground conductor on the mother substrate face each other.

As a result, stray capacitances 70 and 71 (see Fig. 6) are formed between the electrode 66 and the ground conductor of the mother substrate and between the electrode 68 and the ground conductor of the mother substrate. These stray capacitances 70 and 71 are added to the state between the connection point A and the ground in FIG. 5, and between the connection point B and the ground, respectively. Therefore, the stray capacitance 70 is connected in parallel to the first micro stripline 57, and the stray capacitance 71 is connected in parallel to the varactor diode 59.

As a result, the inductance value of the entire reactance circuit 55 increases, and as shown by the line X in FIG. 8, for example, in the l700 MHz oscillator, the change of the oscillation frequency before and after the installation to the mother substrate (ΔF) ) Is approximately minus 9 MHz (frequency is lowered after installation). For this reason, in order to achieve the same oscillation frequency, it is necessary to increase the control voltage V. However, when the maximum value of the control voltage V is limited, there is a problem that the same frequency cannot be set. Moreover, when this oscillator is used as a transceiver, a problem arises in that a predetermined local oscillation frequency or carrier frequency cannot be obtained.

Therefore, an object of the present invention is to reduce the variation of characteristics such as oscillation frequency after installation on a mother substrate with respect to characteristics such as oscillation frequency before installation on a mother substrate.

1 is a circuit diagram of an electronic circuit unit of the present invention;

2 is a bottom view of the electronic circuit unit of the present invention;

3 is a cross-sectional view of main parts of an electronic circuit unit of the present invention;

4 is an explanatory diagram of a through hole in the electronic circuit unit of the present invention;

5 is an explanatory diagram of a state in which the electronic circuit unit of the present invention is installed on a mother board;

6 is a circuit diagram of a conventional electronic circuit unit,

7 is a cross-sectional view of main parts of a conventional electronic circuit unit;

Fig. 8 is a characteristic diagram illustrating a change in oscillation frequency of the electronic circuit unit of the present invention and the conventional electronic circuit unit.

※ Explanation of symbols for main parts of drawing

1: oscillation transistor 2: DC blocking capacitor

3, 4: feedback capacitor 5: emitter bias resistor

6: parallel resonant circuit 6a: third micro stripline

6b: resonance capacitor 7: variable reactance circuit

8: club condenser 9: first micro stripline

10: frequency correction capacitor 10a, 10b: electrode portion

11: varactor diode 12: second micro stripline

21 amplification transistor 22 coupling capacitor

23 fourth microstripline 24 resonant capacitor

25, 26, 27: bus bias resistor 28, 29: stray capacitance

31: multilayer board

31a, 31b, 31c, 31d, 31e, 31f: conductor layer

32: first through hole 32a: conductor wall

32b: electrode 33: second through hole

33a: conductor wall 33b: electrode

34: third through hole 35: fourth through hole

36: Resin 37: Solder

38: Resin 41: Mother Board

41a: grounding conductor 42: circuit components

In order to solve the above problems, an electronic circuit unit of the present invention includes a multilayer board, a circuit component provided on an upper surface of the multilayer board, a microstrip line formed on an inner layer of the multilayer board, and installed through the multilayer board. And a through hole for connecting the micro strip line, a conductor wall is formed in the through hole, the micro strip line is connected to the conductor wall, a resin is filled in the through hole, and one side of the filled resin is provided. An electrode was formed only at the end surface, and the circuit component was installed on the electrode.

In addition, the electronic circuit unit of the present invention is configured as an oscillator, the oscillator has a resonant element for setting the oscillation frequency, the microstripline has at least a first microstripline, the first microstripline to the resonator element It was set as.

The electronic circuit unit of the present invention also has a varactor diode for changing the oscillation frequency as the circuit component, an inductor for supplying a control voltage to the varactor diode, and the micro stripline also has a second micro stripline. The second micro strip line was used as the inductor.

EMBODIMENT OF THE INVENTION Hereinafter, the electronic circuit unit of this invention is demonstrated according to drawing. Here, the electronic circuit unit will be described as an example of the oscillator. 1 is a circuit diagram of an oscillator to which the present invention is applied, FIG. 2 is a bottom view of the electronic circuit unit of the present invention, FIG. 3 is a sectional view of the main portion of the electronic circuit unit of the present invention, and FIG. 4 is an electronic circuit unit of the present invention. It is explanatory drawing of the through-hole in FIG. 5: is explanatory drawing of the state which installed the electronic circuit unit of this invention in the mother board, such as a transceiver.

First, in FIG. 1, the collector of the oscillation transistor 1 is grounded at high frequency by the DC blocking capacitor 2, and the feedback capacitor 3, between the base and the emitter, and between the emitter and the ground, respectively. 4) is connected. The emitter is connected to the ground by a series circuit of the emitter bias resistor 5 and the parallel resonant circuit 6. The variable reactance circuit 7 is connected between the base and the ground. The variable reactance circuit 7 is connected in parallel to the feedback capacitors 3 and 4 connected in series, and acts as an inductance element equivalently at the oscillation frequency.

The variable reactance circuit 7 includes a crab capacitor 8, a first micro strip line 9, a frequency correction capacitor 10, and a varactor diode 11, and a crab capacitor 8 and a first micro strip line. (9) is connected in series, and the frequency correction capacitor 10 and the varactor diode 11 are connected in series. Then, the frequency correction capacitor 10 and the varactor diode 11 connected in series are connected in parallel to the first micro stripline 9. One end of the crab capacitor 8 is connected to the base of the oscillation transistor 1, and one end of the first micro stripline 9 and the anode of the varactor diode 11 are grounded together.

The control voltage V for changing the oscillation frequency is applied to the cathode of the varactor diode 11 via the second micro stripline 12 used as the choke inductor.

Further, the parallel resonant circuit 6 connected between the emitter of the oscillation transistor 1 and the ground reduces the loss of oscillation power in the emitter bias resistor 5, and the third micro strip line 6a. And a resonant capacitor 6b, the resonant frequency of which is set to match the oscillation frequency.

The oscillation signal from the oscillation transistor 1 is amplified by the amplifying transistor 21. Therefore, the oscillation signal is input from the emitter of the oscillation transistor 1 to the base of the amplifying transistor 21 via the coupling capacitor 22. The amplified oscillation signal is output from the collector of the amplifying transistor 21. The power supply voltage E is supplied to the collector of the amplifying transistor 21 via the fourth micro strip line 23. In addition, the resonant capacitor 24 and the fourth microstripline 23 connected between the collector and the ground of the amplifying transistor 21 form a parallel resonance circuit, and the resonance frequency coincides with the oscillation frequency, thereby harmonics. Is removing.

In addition, the emitter of the amplifying transistor 21 and the collector of the oscillation transistor 1 are connected to each other, and almost the same collector current flows in common in the amplifying transistor 21 and the oscillation transistor 1. The bias voltages are applied to the bases of the transistors 1 and 21 by the bias resistors 25, 26 and 27, and almost the same voltage is applied between the collector emitters of the transistors 1 and 21.

The oscillation circuit is composed of a multilayer substrate 31 (see Figs. 2 and 3). At this time, circuit components such as the oscillation transistor 1, the feedback capacitor 3, and the base bias resistor 25 are placed on the upper surface of the multilayer substrate 31 (in Fig. 3, only the frequency correction capacitor is shown in the description). ). In addition, the first to fourth micro strip lines 9, 12, 6a, and 23 are formed on the inner layer of the multilayer substrate 31. Therefore, for example, the first through hole (hereinafter referred to as the through hole is referred to as a through hole) at the connection point a between the crab capacitor 8, the frequency correcting capacitor 10, and the first micro strip line 9, respectively. (32) is provided, and the second through hole (33) is provided at the connection point (b) of the frequency correcting capacitor (10), the varactor diode (11), and the second micro stripline (12). A third through hole 34 is provided at the junction c between the collector of the transistor 21 and the fourth microstripline 23 and the resonant capacitor 24, and the emitter bias resistor 5 and A fourth through hole 35 is provided at the connection point d between the three microstrip lines 6a and the condenser 6b.

These first through fourth through holes 32, 33, 34, 35 penetrate to the lower surface of the multilayer substrate 31 as shown in FIG.

Further, the lower surface of the multilayer board 31 includes a grounding conductor 31a for connecting to the mother substrate (see Fig. 5), a conductor for output of oscillation signal 3lb, a conductor 31c for power supply voltage E, and a control voltage ( V) A conductor 31d and a grounding conductor 3lf are provided.

3 is a sectional view showing main parts of the first through hole 32 and the second through hole 33. Although not shown, the third through hole 34 and the fourth through hole 35 have substantially the same configuration. .

In FIG. 3, in the first through hole 32 and the second through hole 33, conductor walls 32a and 33a are formed by means of plating or the like. Moreover, resins 36 and 36 are filled therein, and electrodes 32b and 33b are formed only on one end surface thereof (upper surface on which circuit components are mounted). Accordingly, the conductor wall 32a and the electrode 32b in the first through hole 32 are connected to each other, and the conductor wall 33a and the electrode 33b in the second through hole 33 are connected to each other. do. These through holes 32 and 33 are often referred to as chip-on through holes because they are filled with resins 36 and 36 and are blocked by the electrodes 32b and 33b, and are used for high density installation. Then, the electrode portions 10a and 10b of the frequency correction capacitor 10 are placed on the electrodes 32b and 33b on the upper side of the multilayer substrate 31, respectively, and the electrode portions 10a, 32b, and electrodes are placed thereon. The negative portion 10b and the electrode 33b are connected to each other by the solders 37 and 37.

Although not shown, the crab capacitor 8 is also placed on the electrode 32b to be soldered.

In addition, the cathode of the varactor diode 11 is placed on the electrode 33b and connected to the solder 37. The anode of the varactor diode 11 is connected to the ground conductor 31g by solder 37.

The first microstripline 9 and the second microstripline 12 are formed by the conductor layer 31e of the inner layer of the multilayer substrate 31, and are connected to the conductor walls 32a and 33a, respectively. Therefore, the frequency correction capacitor 10 and the first micro stripline 9 and the second micro stripline 12 are connected.

On the other hand, the lower surface of the multilayer substrate 31 is provided with a conductor layer 31f of an outer layer facing the first microstripline 9 and the second microstripline 12, and the conductor layer 31f is grounded. do. As a result, the first micro stripline 9 and the second micro stripline 12 have a predetermined characteristic impedance.

In addition, an electrode for blocking these through holes 32 and 33 is formed on the other end surface (lower surface side of the multilayer substrate 31) of the resins 36 and 36 filled in the first through holes 32 and the second through holes 23. Is not formed. As a result, the conductor walls 32a and 33a of the through holes 32 and 33 become annular, as shown in FIG. 4, and are exposed to the lower surface side of the multilayer substrate 31.

The impedance of the first micro strip line 9 is adjusted to have a predetermined oscillation frequency by a predetermined control voltage V applied to the varactor diode 11. This adjustment is called trimming and is performed by, for example, applying a cutting depth to the first micro stripline 9.

Thereafter, the entire lower surface of the multilayer substrate 31 is coated with the resin 38 to complete the oscillator.

The oscillator of the present invention configured as described above is used, for example, as a local oscillator or a carrier oscillator of a transceiver such as a cellular phone. At that time, as shown in Fig. 5, the multilayer board 31 constituting the electronic circuit unit of the present invention is mounted together with other circuit components 42 on the mother board 41 constituting the transceiver.

In the state where the multilayer substrate 31 is mounted, the lower surface of the multilayer substrate 31 faces the upper surface of the mother substrate 41. As a result, when the ground conductor 41a is provided on the upper surface of the mother substrate 41, the conductor wall 32 of the first through hole 32 and the conductor wall 33a of the second through hole 33 Although it opposes the grounding conductor 41a, since this opposing area | region becomes ring-shaped, the facing area becomes small compared with the conventional opposing area. Therefore, the floating capacitance 28 (refer to FIG. 1) formed by opposing the conductor wall 32a and the ground conductor 41a becomes smaller than the conventional floating capacitance 70 shown in FIG. 6, and similarly, the conductor wall 33a ) And the floating capacitance 29 (refer to FIG. 1) formed by opposing the ground conductor 41a are also smaller than the conventional floating capacitance 71 shown in FIG.

Therefore, the change ΔF of the oscillation frequency in the case where the electronic circuit unit of the present invention is provided on the mother substrate 41 is small, and becomes almost (minus 3 MHz) as indicated by the line Y in FIG. . This change is one third of the conventional change (minus 9 MHz).

Also, like the first and second through holes 32 and 33, only the conductor walls (not shown) formed in the third through holes 34 and the fourth through holes 35 are exposed to the lower surface side of the multilayer substrate 31. In this case, changes in the resonant frequency of the fourth micro stripline 23 and the resonant capacitor 24 and the resonant frequency of the third micro strip line 6a and the resonant capacitor 6b are reduced.

In the above description, the oscillator has been described as an example of the electronic circuit unit. However, the present invention is not limited to the oscillator and can be applied to other electronic circuit units using microstrip lines or the like to obtain excellent effects.

As described above, the electronic circuit unit of the present invention connects a circuit component provided on the upper surface of the multilayer board with a microstrip line formed in the inner layer of the multilayer board through a through hole, and fills the resin in the through hole only on one end surface of the resin. In the case where the multilayer board is placed on the mother board because the electrode is formed and the circuit components are provided on the electrode, the float formed by the conductor wall and the ground conductor even if the conductor wall of the through hole faces the ground conductor of the mother board. Due to the small capacity, there is little change in the characteristics of the electronic circuit.

In addition, since the electronic circuit unit of the present invention is configured as an oscillator, the oscillator has a resonant element for setting the oscillation frequency, and the microstripline has at least a first microstrip line and the first microstripline is a resonator element. Is installed on the mother substrate, the stray capacitance added to the resonant element is small. Therefore, even if the oscillator is installed on the mother board, the change of oscillation frequency is small.

In addition, the electronic circuit unit of the present invention has a varactor diode that changes oscillation frequency as a circuit component, has an inductor for supplying a control voltage to the varactor diode, and the micro strip line also has a second micro strip line and a second micro strip. Since the line is used as an inductor, the stray capacitance added to the varactor is reduced when the oscillator is installed on the mother board. Therefore, the frequency change range by varactor diodes does not become narrow.

Claims (3)

A multilayer board, a circuit component provided on an upper surface of the multilayer board, a micro strip line formed on an inner layer of the multilayer board, and a through hole formed in the multilayer board to connect the circuit component and the micro strip line. A conductor wall is formed in the through hole to connect the microstripline to the conductor wall, and a resin is filled in the through hole to form an electrode only on one end surface of the filled resin; An electronic circuit unit comprising a component. The method of claim 1, The electronic circuit unit is configured as an oscillator, the oscillator having a resonant element for setting an oscillation frequency, the micro stripline having at least a first micro stripline, and the first micro stripline as the resonant element. An electronic circuit unit. The method of claim 2, The circuit component has a varactor diode that changes the oscillation frequency, has an inductor for supplying a control voltage to the varactor diode, the micro stripline also has a second micro stripline, the second micro stripline And the inductor.