JP2002314339A - Structure of highly stabilized piezo-oscillator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a means for making a highly stabilized piezo-oscillator small and thin and also stabilizing it. SOLUTION: The structure of the highly stabilized piezo-oscillator comprises a piezoelectric resonator, an amplifier, a small thermostat and a printed circuit board on which these parts are mounted, and hermetically seals the piezoelectric resonator related to the stability of an oscillation frequency, the amplifier and temperature controlling part integrally with various central parts of the printed board so as to vertically hold with two divided metal blocks.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a high stability piezoelectric oscillator, and more particularly to a structure of a high stability piezoelectric oscillator in which a thermostat and a printed board are integrated to reduce the size and thickness.

[0002]

2. Description of the Related Art High-stability crystal oscillators are superior in frequency accuracy, frequency temperature characteristics, frequency aging characteristics and the like to general piezoelectric oscillators, and are therefore used in various measuring instruments, mobile radio base stations, and satellite communication equipment. Widely used.
In particular, in recent years, with the spread of portable telephones, the demand for small and highly stable crystal oscillators with low power consumption for base stations has been increasing. As is well known, the configuration of a high-stable crystal oscillator can be roughly divided into a crystal oscillator, a transistor, a resistor, a capacitor,
It is composed of electronic components such as a temperature-sensitive element, a printed circuit board, a small thermostat having a heat source, a metal case and a base for housing the components. By housing the crystal unit, oscillation amplifier, temperature sensing element, etc. in a small thermostat, the temperature of the crystal unit is always kept constant even if the ambient temperature of the crystal oscillator changes. Has become. In addition,
Various types of small thermostats have been put into practical use, such as a thermostat in which a heater is wound around a metal block or a thermostat in which a heating element is fixed to a metal block.

FIG. 7 is a cross-sectional view showing the structure of a conventional high-stable crystal oscillator. The bottom of a small thermostat 33 having a built-in crystal oscillator 32 is fixed to one surface of a printed circuit board 31 and the crystal is fixed. Connect the terminals of the vibrator 32 to the printed circuit board 31
Connect to the circuit formed above. Further, the other surface of the printed circuit board 31 is soldered with an oscillation circuit and an amplification circuit 35, a heater control circuit 36 of the constant temperature bath 33, and the like.
And the base 3 to which the inverted L-shaped support 37 is attached
After mounting and fixing the printed circuit board 31 on 8, a metal case 39 is attached to a base 38 to constitute a highly stable crystal oscillator. The supply of the power for the oscillation and the small thermostat, the grounding, and the derivation of the oscillation output are performed through the hermetic terminals 34 attached to the base 38.

However, as described above, in a high-stable crystal oscillator of a type in which only the crystal oscillator 32 is built in an open small thermostat 33, the crystal oscillator 32 and the oscillation circuit are in a completely sealed state. Therefore, there is a problem that the frequency stability is inferior to the conventional high stability crystal oscillator using a thermostat having a large frequency stability due to the influence of the temperature change around the high stability crystal oscillator. In order to solve this problem, as shown in FIG.
2, oscillation circuit and amplification circuit 35, heater control circuit 36,
The heater 40 and the power transistor 41 are soldered, and these are connected to the aluminum blocks 33a, 33
A high-stability crystal oscillator of the type surrounded by b is manufactured.

[0005]

However, in the highly stable crystal oscillator having the above structure, the heater 4
0 and the aluminum blocks 33a and 33b produce a gap, heat is not smoothly conducted between the two, and it takes too much time to stabilize the internal temperature, and the rise of the highly stable crystal oscillator is slow. There was a problem. In order to conduct the heat conduction smoothly, the heater 40 and the aluminum blocks 33a, 33b may be processed so as to be in contact with each other, but it is extremely difficult to perform the mechanical processing. Therefore, there is a method of filling a resin with good thermal conductivity, but it is difficult to fill the space between the heater 40 and the aluminum blocks 33a and 33b with the resin in the recessed portion, and the inside of the closed structure cannot be visually observed. A new problem arises in that the state of filling cannot be confirmed. The present invention has been made to solve the above-described problem, and has as its object to provide a small, thin, and highly stable crystal oscillator having high frequency stability.

[0006]

According to a first aspect of the present invention, there is provided a structure of a highly stable piezoelectric oscillator according to the present invention, wherein a piezoelectric vibrator is provided on both sides of a single printed circuit board. An oscillation circuit for exciting the piezoelectric vibrator, a heater, and a temperature control circuit for controlling the temperature of the heater are arranged, and an upper surface of the printed board is surrounded by a first metal block, and the printed board is surrounded by a first metal block. A high-stable oscillator having a lower surface surrounded by a second metal block, wherein a notch is provided at an end of the metal block, and the heater is disposed on a printed circuit board corresponding to the notch; A highly stable piezoelectric oscillator characterized in that a resin is filled in a portion. According to a second aspect of the present invention, a piezoelectric vibrator, an oscillation circuit for exciting the piezoelectric vibrator, a heater, and a temperature control circuit for controlling the temperature of the heater are arranged on one surface of one printed circuit board. A highly stable oscillator having an upper surface of the printed circuit board surrounded by a first metal block and a lower surface of the printed circuit board surrounded by a second metal block; A notch portion, the heater is arranged on a printed circuit board corresponding to the notch portion, resin is filled in the notch portion, and the second metal block is a flat plate-shaped member. It is a highly stable piezoelectric oscillator. According to a third aspect of the present invention, the power transistor constituting the oscillator is disposed on a printed circuit board corresponding to the notch provided at the end of the metal block, similarly to the heater. 2. A high-stability piezoelectric oscillator according to item 2.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail based on an embodiment shown in the drawings. FIG. 1A is a perspective view showing the structure of a highly stable crystal oscillator according to the present invention, and FIGS. 1B and 1C are cross-sectional views, each showing a crystal resonator 1, an oscillation circuit, an amplification circuit, An electronic component 2 such as a transistor, a resistor, a capacitor, and a temperature sensing element, which constitutes a temperature control circuit, is soldered to both main surfaces of a printed circuit board 3, and these electronic components are divided into two upper and lower parts made of aluminum. The central portions of the printed circuit board 3 are sealed at 4a and 4b. Then, the hermetic terminals 6, 6, which are fixed to the corners of the metal base 5 by soldering,
In addition, while fixing by soldering through the through holes formed in the printed circuit board 3, a case 7 is put on the base 5 and hermetically sealed by soldering. The application of voltage, grounding, and extraction of oscillation output are performed via the hermetic terminal.

The internal structure sealed by the case 7 and the base 5 has upper and lower blocks 4a and 4b as shown in FIG. The printed circuit board 3 on which the printed circuit board 2 is mounted is hermetically sealed so as to be sandwiched from both upper and lower sides and fixed with screws 8, 8,. And blocks 4a, 4b
A hermetic terminal 6 soldered to a base 5 in a through hole provided at an end of a printed circuit board extending outside
The printed circuit board 3 has a structure that supports an aluminum block that is integrated together by penetrating through through 6 and soldering. FIG. 1C is a cross-sectional view taken along the line QQ. Both ends of the center of the upper and lower blocks 4a and 4b are cut in a rectangular shape. , Which are heat sources, and a power transistor 10. The space is filled with a resin having good thermal conductivity to increase the efficiency of generated heat.

A feature of the present invention is that a quartz oscillator 1 and an electronic component 2 are provided.
In addition to mounting all electric components such as a ceramic heater on both sides of a single printed circuit board 3, components essential for frequency stability such as the crystal unit 1, electronic components for an oscillation circuit, and temperature-sensitive elements are printed on the printed circuit board 3. From above and below by using aluminum blocks 4a and 4b, and thermally sealed completely. With such a structure, heat distribution is stabilized, miniaturization and thinning are possible, and cost reduction of a highly stable crystal oscillator is achieved.

Here, in order to make the structure of the present invention easy to understand, description will be made separately for each mechanical component. FIG. 2 (a),
(B) is a plan view showing a configuration of a front surface (hereinafter, referred to as a B surface) and a rear surface (hereinafter, a Pt surface) of the printed circuit board 3 on which electronic components are mounted. The printed board 3 is provided with four holes 11 through which the upper and lower blocks 4a and 4b are joined to form the printed board 3 and the block 4.
a and 4b are integrally fixed. 2A, four terminals 12 of the crystal unit 1 attached to the Pt surface on the back surface are fixed to the center part of the surface B by soldering through the four printed circuit boards 3. The electronic components 2, 2,.
・ Is arranged. Further, electronic components 2, 2,... Are arranged at both left and right ends in the figure on the side B, avoiding the hermetic terminals 6. Ceramic heaters 9, 9,..., Which are heat sources for the thermostat, are arranged on both upper and lower ends of the surface B in the figure. The small dot pattern 13 is a solder-plated ground surface provided on the printed circuit board 3, and this surface is in contact with a part of the block 4a to keep the airtight. FIG. 2B shows a Pt surface of the printed circuit board 3. A quartz oscillator 1 is mounted at the center of the printed circuit board 3, and electronic devices are provided at the left and right ends of the printed circuit board 3 so as to avoid the hermetic terminals 6. Parts 2, 2,... Are arranged. Further, ceramic heaters 9, 9,..., Which are heat sources of a thermostat, and a power transistor 10 are arranged at both upper and lower ends of the Pt surface in the figure. The small dot pattern 13 is a ground surface solder-plated as described above, and is in contact with the block 4b to form a closed space.

FIGS. 3 (a), 3 (b), 3 (c) and 3 (d) show two aluminum blocks constituting a small thermostat respectively.
FIGS. 5A and 5B are a plan view and a side view of the upper half block 4a, and FIGS. 6C and 6D are lower and upper views, respectively. It is the top view and side view of half block 4b. The lower half block 4 is located at the four corners of the upper half block 4a shown in FIGS.
Four screw holes 14a are formed for joining with the b. A recess 15 for accommodating the head of an inductor, which is one of the electronic components 2, is formed in the center of the block 4a. At the four corners of the lower half block 4b shown in FIGS. 3 (c) and 3 (d), four screw holes 14b are formed at the center of the circular projection 16 to be joined to the upper half block 4a. Is formed. The protruding portion 16 is configured so that the central portion of the printed board is integrally sandwiched between upper and lower blocks 4a and 4b through four holes 11 formed in the printed board 3. A hole 17 is formed in the center of the block 4b so as to fit with the case of the crystal unit 1 so as to be integrated with the crystal unit 1 and the block 4b.

FIG. 4 shows electronic components on both sides of the printed circuit board 3.
After soldering the power transistor and the ceramic heater, and attaching the crystal unit 1 to the Pt surface, the center of the printed circuit board 3 is fixed to an aluminum block 4a.
It is sectional drawing of what was fixed with four screws 8 so that it might be pinched integrally by 4b. At this time, the notch formed by the ceramic heater 9, the power transistor 10 and the aluminum blocks 4a and 4b soldered on the printed board 3 is filled with a silicon resin having good thermal conductivity, and the space between the two is filled. The balance of heat is made promptly. In this case, it is desirable to fill the gap between the crystal unit 1 and the aluminum block 4b with silicon resin.

FIG. 5 shows a modified embodiment of the present invention. In order to further reduce the height of the high stability crystal oscillator, the bottom surface of the aluminum block 4'b is cut off, and the case of the crystal unit 1 penetrates the aluminum block. This is an example.

FIGS. 6 (a) and 6 (b) show another modified embodiment of the present invention. FIG. 6 (a) omits the illustration of the case and the aluminum block.
FIG. 1B is a plan view showing a state in which the electronic component 1 and electronic components 22, 23 and the like are mounted. FIG. In order to further reduce the height of the high-stable piezoelectric oscillator shown in FIG. 5, a high-stable piezoelectric oscillator in which all electronic components including a crystal oscillator are mounted on one surface of a printed circuit board.
A quartz oscillator 21 having a height of 4.6 mm and a low height on one surface of a printed circuit board 20, and electronic components 22 and 2 for an oscillation circuit.
2, electronic components 23 for amplification and temperature control, a ceramic heater 24a, a power transistor 24b, and the like. The central portion of the printed circuit board 20 is sandwiched between upper and lower blocks 25a and 25b through four holes 25c opened in the printed circuit board 20, and is fixed by screws. And block 2
5a is provided with a hole for fitting the crystal oscillator at a position corresponding to the crystal oscillator 21.
a. A notch is formed in the aluminum block 25a, and a heater 24a and a power transistor 24b are arranged on the printed circuit board 20 corresponding to the notch, and a silicon resin having good thermal conductivity is filled in the gap. Is similar to the example of FIG.

A feature of the present invention is that an electronic component is printed on a printed circuit board 2.
0, the height of the high-stable oscillator can be greatly reduced, and the aluminum block 25a on the upper surface side of the printed circuit board 20 is almost the same as that of FIG. That is, the structure of the aluminum block 25b can be made into a flat plate shape, and the cost can be reduced. Furthermore, by providing a plurality of slits 26 for heat insulation disclosed in JP-A-3-14303 on the printed circuit board 20, the thermal efficiency can be improved.

In the above description, a quartz oscillator is used as the piezoelectric oscillator. However, it is needless to say that the present invention is not limited to this, and can be applied to a piezoelectric oscillator using a langasite oscillator or the like. .

[0017]

Since the present invention is constructed as described above, the first aspect of the present invention has an excellent effect of realizing a highly stable piezoelectric oscillator which is small and thin and has excellent frequency stability. Represents The invention described in claim 2 is
In addition to the above, the effect that a highly stable piezoelectric oscillator that efficiently utilizes the heat generated by the power transistor can be realized.
The invention according to claim 3 has an advantage that the height of the high-stability piezoelectric oscillator can be significantly reduced.

[Brief description of the drawings]

FIG. 1A is a perspective view showing a configuration of a highly stable piezoelectric oscillator according to the present invention, FIG. 1B is a cross-sectional view taken along line PP, and FIG.
Is a sectional view taken along the line QQ.

FIG. 2A shows a printed circuit board B on which electronic components are mounted.
FIG. 4B is a plan view showing a configuration of a Pt surface (back surface).

3A is a plan view of an upper half portion of an aluminum block, FIG. 3B is a side view thereof, FIG. 3C is a plan view of a lower half portion of the block, and FIG. 3D is a side view thereof.

FIG. 4 is a sectional view of an electronic component mounted on a printed circuit board and further integrated by upper and lower blocks.

FIG. 5 is a sectional view showing a configuration of another embodiment of the present invention.

6A is a plan view and FIG. 6B is a cross-sectional view illustrating a configuration of another embodiment of the present invention.

FIG. 7 is a cross-sectional view illustrating a configuration of a conventional high stability crystal oscillator.

FIG. 8 is a cross-sectional view showing a configuration of a conventional high stability crystal oscillator having another structure.

[Explanation of symbols]

1, 21, crystal oscillator 2, 22, 23, electronic component 3, 20, printed circuit board 4a, 4b, 4'b, 25a, 25b, aluminum block 5, base 6, terminal 7,・ Case 8 ・ ・ Screw 9, 24a ・ ・ Ceramic heater 10, 24b ・ ・ Power transistor 11 ・ ・ Hole on printed circuit board 12 ・ ・ Terminal of crystal oscillator 13 ・ ・ Solder-plated ground 14a ・ ・ Screw Hole 15, recess 16, protrusion 17, hole for crystal oscillator 18, 19, space created by printed circuit board and block 26, slit

Claims (3)

[Claims] 1. A piezoelectric vibrator, an oscillation circuit for exciting the piezoelectric vibrator, a heater, and a temperature control circuit for controlling the temperature of the heater are arranged on both sides of one printed circuit board. A highly stable oscillator having an upper surface of the printed circuit board surrounded by a first metal block and a lower surface of the printed circuit board surrounded by a second metal block, wherein a notch is provided at an end of the metal block. A high-stability piezoelectric oscillator, wherein the heater is arranged on a printed circuit board corresponding to the notch, and a resin is filled in the notch. 2. A piezoelectric vibrator, an oscillating circuit for exciting the piezoelectric vibrator, a heater, and a temperature control circuit for controlling the temperature of the heater are arranged on one surface of one printed circuit board. A highly stable oscillator having an upper surface of the printed circuit board surrounded by a first metal block and a lower surface of the printed circuit board surrounded by a second metal block, wherein a notch is formed at an end of the first metal block. Wherein the heater is arranged on a printed circuit board corresponding to the cutout, and the cutout is filled with resin, and the second metal block is a flat plate-shaped member. Piezoelectric oscillator. 3. The power transistor according to claim 1, wherein the power transistor constituting the oscillator is disposed on a printed circuit board corresponding to a notch provided at an end of the metal block, similarly to the heater. A highly stable piezoelectric oscillator as described.