JP2012085045A - Oven-controlled crystal oscillator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an oven-controlled crystal oscillator that has improved reliability by reducing cracks caused in solder mounting large circuit components.SOLUTION: The oven-controlled crystal oscillator has slits 3 formed around or under a large circuit component 2 formed on a substrate 1 and, when necessary, a plurality of small circuit components 4 smaller than the large circuit component 2 arranged around the large circuit component 2, in which the plurality of small circuit components 4 arranged include electronic components which are electrically connected and dummy electronic components which are not electrically connected.

Description

  The present invention relates to an oven controlled crystal oscillator (OCXO), and in particular, when circuit components are soldered on a substrate, the occurrence of cracks in the solder is reduced to improve reliability. The present invention relates to a crystal oscillator with a thermostatic bath.

[Conventional technology]
In order to increase the frequency stability, the temperature controlled crystal oscillator is designed to stabilize the frequency by controlling the temperature of a part having a large temperature influence over a wide temperature range.
The temperature control in the crystal oscillator with a thermostat is generally performed by a control circuit that controls the thermostat with a differential DC amplifier using a resistance bridge using a thermistor. When the power supply of the thermostat is repeatedly turned on and off, the heat cycle is applied to the parts and materials used, and there is a problem in reliability.

[Examples of circuit component mounting: FIGS. 9 and 10]
Conventionally, a case where a large circuit component (large circuit component) is mounted on a substrate of a crystal oscillator will be described with reference to FIGS. FIG. 9 is an explanatory plan view of large circuit component mounting, and FIG. 10 is a cross-sectional explanatory diagram of large circuit component mounting.
As shown in FIGS. 9 and 10, a large circuit component (large circuit component) 2 is fixed on a glass epoxy resin substrate 1 by solder 10.

  9 and 10, in order to simplify the explanation, one large circuit component 2 is mounted on a small substrate 1 and is simplified. However, on an actual substrate 1, a crystal resonator is provided. And a plurality of large and small circuit components.

[Related technologies]
As related prior art, Japanese Patent Application Laid-Open No. 2007-214307 “Electronic Device” (Epson Toyocom Corporation) [Patent Document 1], Japanese Patent Application Laid-Open No. 08-237031 “Piezoelectric Oscillator” (Kinseki Corporation) [Patent Document] 2], Japanese Utility Model Laid-Open Publication No. 62-037428, “Piezoelectric Oscillator” (Kinseki Co., Ltd.) [Patent Document 3].

Patent Document 1 shows that in an electronic device, an opening 38 and a cut portion 40 are provided in a substrate 30 on the lower side of an electronic component, and cracking of the sealing material 12 due to air expansion can be reduced. .
Patent Document 2 shows that in a piezoelectric oscillator, a slit 5 is formed so as to surround an oscillation circuit component 3 arranged on a substrate 4, and heat diffusion can be reduced.
Patent Document 3 discloses that in a piezoelectric oscillator, as shown in FIG. 1, a slit-like through-hole portion 16 is formed in a substrate 14 to suppress a problem due to a difference in expansion coefficient and to improve frequency temperature characteristics. It has been shown.

JP 2007-214307 A JP-A-08-237031 Japanese Utility Model Publication No. 62-037428

  However, in the conventional crystal oscillator, when glass epoxy resin is used for the circuit board, there is a difference in the linear expansion coefficient between the circuit component of the electronic component using, for example, ceramic and the glass epoxy resin material mounted on the circuit board. Therefore, in a use environment where a heat cycle occurs, there is a problem that distortion concentrates on the mounting solder and cracks occur in the solder.

Here, as for the linear expansion coefficient of the glass epoxy resin material, general CEM (Composite Epoxy Material) -3 is 25 ppm / ° C. in the vertical direction, 28 ppm / ° C. in the horizontal direction, and 65 ppm / ° C. in the thickness direction. FR (Flame Retardant) -4 is 13 ppm / ° C. in the vertical direction, 16 ppm / ° C. in the horizontal direction, and 60 ppm / ° C. in the thickness direction.
The linear expansion coefficient of the ceramic (alumina substrate) is 7 ppm / ° C.

  It is known that cracks in solder generally occur in larger circuit components than in smaller circuit components. However, there are circuit components that cannot be miniaturized due to the performance and constants of the components, and there are many cases where large circuit components must be used.

  In particular, in a crystal oscillator with a thermostat (OCXO), in a use environment in which the power supply is repeatedly turned on / off, that is, in a use environment where a heat cycle occurs, the temperature change from the ambient temperature to the thermostat control temperature (for example, 85 ° C.) As a result, cracks occur in the mounting solder of large circuit components, and there is a problem that reliability cannot be improved.

Further, Patent Document 1 is intended to reduce the occurrence of cracks in the sealing material 12 due to air expansion, but does not reduce the occurrence of cracks in the mounting solder of large circuit components.
In Patent Document 2, the slit 5 prevents heat from diffusing to other portions, but does not reduce the occurrence of cracks in the mounting solder of large circuit components.
In Patent Document 3, a slit-shaped through hole is formed to suppress problems caused by differences in expansion coefficient and improve frequency temperature characteristics. However, cracks occur in the mounting solder of large circuit components. The position of the through hole is not devised so as to reduce it.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a thermostat crystal oscillator capable of reducing the occurrence of cracks in the mounting solder of large circuit components and improving the reliability.

  The present invention for solving the problems of the conventional example described above is that in the crystal oscillator with a thermostatic bath, the circuit components formed on the substrate are provided with L-shaped slits on the substrate so as to surround the four corners of the circuit components. It is characterized by that.

  The present invention provides a crystal oscillator with a thermostatic chamber, and for circuit components formed on a substrate, slits are provided in parallel on the substrate along the outside of the long sides of the circuit components, and the slits provided in parallel are provided for the circuit components. It is characterized by providing a slit to be connected on the lower side.

  The present invention is characterized in that, in the crystal oscillator with a thermostatic bath, slits are provided on the substrate along the outer sides of the four sides of the circuit component for the circuit component formed on the substrate.

  The present invention is characterized in that, in the crystal oscillator with a thermostatic bath, a slit is provided on the substrate along the outer side of the short side of the circuit component for the circuit component formed on the substrate.

  The present invention is characterized in that, in the crystal oscillator with a thermostatic bath, a slit is provided on the substrate along the outside of the long side of the circuit component for the circuit component formed on the substrate.

  The present invention is characterized in that, in the crystal oscillator with a thermostatic bath, a small circuit component smaller than the circuit component is arranged on the substrate along the outside of the short side of the circuit component.

  The present invention is characterized in that, in the crystal oscillator with a thermostatic bath, a small circuit component smaller than the circuit component is arranged on the substrate along the outside of the long side of the circuit component.

  The present invention provides a crystal oscillator with a thermostatic bath, wherein the circuit component formed on the substrate is provided with a slit on the substrate below the circuit component and the short side or the long side of the circuit component, or the short side. In addition, a small circuit component smaller than the circuit component is arranged along the outside of the long side.

  The present invention relates to a circuit oscillator formed on a substrate in a thermostatic oven, wherein the short side portion of the circuit component is soldered and fixed to the substrate, and is parallel to the short side and below the center of the circuit component. And a slit is provided on the substrate.

  The present invention is characterized in that, in the crystal oscillator with a thermostat, the width of the slit is 1.5 mm or less (for example, 0.6 mm to 0.8 mm).

  According to the present invention, the circuit component formed on the substrate is a crystal oscillator with a thermostatic bath provided with L-shaped slits on the substrate so as to surround the four corners of the circuit component. It is possible to reduce the occurrence of cracks and to improve the reliability.

  According to the present invention, for circuit components formed on a substrate, slits are provided in parallel on the substrate along the outside of the long sides of the circuit components, and the slits provided in parallel are connected below the circuit components. Since the crystal oscillator with the thermostatic bath provided with the slit is used, it is possible to reduce the occurrence of cracks in the mounting solder of the circuit component and to improve the reliability.

  According to the present invention, the circuit component formed on the substrate is a crystal oscillator with a thermostatic bath provided with slits on the substrate along the outside of the four sides of the circuit component. Can be reduced and the reliability can be improved.

It is plane explanatory drawing of the circuit component formed on the board | substrate of the crystal oscillator with a thermostat which concerns on 1st Embodiment. It is plane explanatory drawing of the circuit components formed on the board | substrate of the crystal oscillator with a thermostat which concerns on 2nd Embodiment. It is plane explanatory drawing of the circuit components formed on the board | substrate of the crystal oscillator with a thermostat which concerns on 3rd Embodiment. It is plane explanatory drawing of the circuit component formed on the board | substrate of the crystal oscillator with a thermostat which concerns on 4th Embodiment. It is plane explanatory drawing of the circuit components formed on the board | substrate of the quartz crystal oscillator with a thermostat which concerns on 5th Embodiment. It is plane explanatory drawing of the circuit component formed on the board | substrate of the quartz crystal oscillator with a thermostat which concerns on 6th Embodiment. It is plane explanatory drawing of the circuit components formed on the board | substrate of the crystal oscillator with a thermostat which concerns on 7th Embodiment. It is plane explanatory drawing of the circuit components formed on the board | substrate of the crystal oscillator with a thermostat which concerns on 8th Embodiment. It is plane explanatory drawing of large circuit component mounting. It is sectional explanatory drawing of large circuit component mounting.

Embodiments of the present invention will be described with reference to the drawings.
[Outline of the embodiment]
In the crystal oscillator with a thermostatic bath according to the embodiment of the present invention, a slit is formed in the periphery or the lower surface of the circuit component (large circuit component) formed on the substrate, and, if necessary, the large circuit component. A plurality of smaller small circuit components are arranged around a large circuit component, and the plurality of arranged small circuit components use electronic components that are electrically connected and dummy electronic components that are not electrically connected Thus, it is possible to reduce the occurrence of cracks in the mounting solder of large circuit components and to improve the reliability.

[First Embodiment: FIG. 1]
A crystal oscillator with a thermostatic bath according to a first embodiment of the present invention will be described with reference to FIG. FIG. 1 is an explanatory plan view of circuit components formed on the substrate of the thermostatic crystal oscillator according to the first embodiment.
In FIG. 1, for simplicity of explanation, one circuit component (large circuit component) 2 is mounted on a small substrate 1, and a simplified diagram is shown. A vibrator and a plurality of large and small circuit components are mounted. 2 to 8 are also drawn with the same purpose.

  As shown in FIG. 1, a large circuit component (large circuit component) is formed on the substrate 1 made of glass epoxy resin or the like on the substrate of the thermostatic crystal oscillator (first oscillator) according to the first embodiment. 2 is soldered and mounted, and an L-shaped slit 3 a is provided on the substrate so as to surround the four corners of the large circuit component 2.

The large circuit component 2 is a capacitor, resistor, inductor, thermistor, semiconductor, or crystal resonator, and is fixed to the substrate 1 with solder.
Specifically, as shown in FIGS. 9 and 10, it is soldered to the foot portion of the large circuit component 2.

The slit 3 a has a width of about 0.1 mm to 1.5 mm as an example, and a width of about 0.6 mm to 0.8 mm is appropriate from the current circuit scale, and is formed through the substrate 1. The slits in the following embodiments have the same width.
The slits 3a formed on the substrate 1 can alleviate distortion of the substrate 1 due to heat cycles, reduce the occurrence of cracks in the mounting solder of large circuit components, and improve reliability.

[Second Embodiment: FIG. 2]
Next, a thermostatic crystal oscillator (second oscillator) according to a second embodiment will be described with reference to FIG. FIG. 2 is an explanatory plan view of circuit components formed on the substrate of the thermostatic crystal oscillator according to the second embodiment.
As shown in FIG. 2, a large circuit component 2 is soldered and mounted on the substrate 1 of the second oscillator, and slits 3 b are formed in parallel along the short side of the large circuit component 2. .
The slit 3b can also reduce the distortion of the substrate 1 due to the heat cycle, reduce the occurrence of cracks in the mounting solder of the large circuit component 2, and improve the reliability.

[Third Embodiment: FIG. 3]
Next, a thermostatic crystal oscillator (third oscillator) according to a third embodiment will be described with reference to FIG. FIG. 3 is an explanatory plan view of circuit components formed on the substrate of the thermostatic crystal oscillator according to the third embodiment.
As shown in FIG. 3, a large circuit component 2 is mounted by soldering on the substrate 1 of the third oscillator, and slits 3b and 3c are formed in parallel along the short and long sides of the large circuit component 2. Is formed.
The slits 3b and 3c can reduce the distortion of the substrate 1 by the heat cycle, reduce the occurrence of cracks in the mounting solder of the large circuit component 2, and improve the reliability.

[Fourth Embodiment: FIG. 4]
Next, a thermostatic crystal oscillator (fourth oscillator) according to a fourth embodiment will be described with reference to FIG. FIG. 4 is an explanatory plan view of circuit components formed on the substrate of the crystal oscillator with a thermostatic bath according to the fourth embodiment.
As shown in FIG. 4, a large circuit component 2 is soldered and mounted on the substrate 1 of the fourth oscillator, and slits 3 c are formed in parallel along the long side of the large circuit component 2. .
The slits 3c can alleviate distortion of the substrate 1 due to heat cycle, reduce the occurrence of cracks in the mounting solder of the large circuit component 2, and improve reliability.

[Fifth Embodiment: FIG. 5]
Next, a thermostatic bath crystal oscillator (fifth oscillator) according to a fifth embodiment will be described with reference to FIG. FIG. 5 is an explanatory plan view of circuit components formed on the substrate of the thermostatic bath crystal oscillator according to the fifth embodiment.
As shown in FIG. 5, a large circuit component 2 is soldered and mounted on the substrate 1 of the fifth oscillator, and a slit 3 c is formed in parallel along the long side of the large circuit component 2. A slit 3d for connecting the slit 3c provided in parallel at the lower center of the large circuit component 2 is formed.
The slits 3c and 3d can alleviate distortion of the substrate 1 due to the heat cycle, reduce the occurrence of cracks in the mounting solder of the large circuit component 2, and improve the reliability.

[Sixth Embodiment: FIG. 6]
Next, a thermostatic crystal oscillator (sixth oscillator) according to a sixth embodiment will be described with reference to FIG. FIG. 6 is an explanatory plan view of circuit components formed on the substrate of the thermostatic crystal oscillator according to the sixth embodiment.
As shown in FIG. 6, a large circuit component 2 is mounted by soldering on the substrate 1 of the sixth oscillator, and a slit 3 e is formed at the lower center of the large circuit component 2.
The slit 3e can reduce the distortion of the substrate 1 due to the heat cycle, reduce the occurrence of cracks in the mounting solder of the large circuit component 2, and improve the reliability.

[Seventh embodiment: FIG. 7]
Next, a thermostatic crystal oscillator (seventh oscillator) according to a seventh embodiment will be described with reference to FIG. FIG. 7 is an explanatory plan view of circuit components formed on the substrate of the thermostatic crystal oscillator according to the seventh embodiment.
As shown in FIG. 7, a large circuit component 2 is mounted by soldering on the substrate 1 of the seventh oscillator, and a slit 3 b is formed in parallel along the short side of the large circuit component 2. A plurality of small circuit components (small circuit components) 4 a are arranged along the long side of the large circuit component 2. ing.

The small circuit component 4a is a ceramic capacitor, a ceramic resistor (chip resistor), or the like. A plurality of small circuit components 4a are arranged along the long side of the large circuit component 2, and are fixed to the substrate 1 with solder.
In FIG. 7, it is important to regularly arrange the small circuit components 4a around the large circuit components 2, and the small circuit components 4a may be electrically connected or not electrically connected. It may be a dummy electronic component.

  The distance between the large circuit component 2 and the small circuit component 4a is about 0.05 mm to 1 mm. If the distance is long, the space is wasted. Therefore, about 0.1 mm to 0.3 mm is preferable.

  In the seventh oscillator, the slit 3b and the small circuit component 4a alleviate the distortion of the substrate 1 due to the heat cycle, reduce the occurrence of cracks in the mounting solder of the large circuit component 2, and improve the reliability. is there.

  In FIG. 7, the slits are not formed in parallel to the long side of the large circuit component 2, but the small circuit components 4 a are arranged in parallel on the long side of the large circuit component 2. This is because the convenience is high when small circuit components are electrically connected and used.

[Eighth embodiment: FIG. 8]
Next, a thermostatic crystal oscillator (eighth oscillator) according to an eighth embodiment will be described with reference to FIG. FIG. 8 is an explanatory plan view of circuit components formed on the substrate of the thermostatic crystal oscillator according to the eighth embodiment.
As shown in FIG. 8, a large circuit component 2 is soldered and mounted on the substrate 1 of the sixth oscillator, a slit 3e is formed at the lower center of the large circuit component 2, and the large circuit Small circuit components 4 a and 4 b are arranged around the component 2.

Specifically, the small circuit component 4 a is arranged in parallel along the long side of the large circuit component 2, and the small circuit component 4 b is arranged in parallel along the short side of the large circuit component 2.
The distance between the large circuit component 2 and the small circuit components 4a and 4b is the same as that described in the seventh embodiment.

According to the eighth oscillator, the slit 3e and the small circuit components 4a and 4b alleviate the distortion of the substrate 1 due to the heat cycle, and can reduce the occurrence of cracks in the mounting solder of the large circuit component 2, thereby improving the reliability. It can be done.
Moreover, it is highly convenient when one of the arranged small circuit components 4a and 4b is electrically connected and used.

[Effect of the embodiment]
According to the first to eighth oscillators, the slits 3a to 3e are formed around the large circuit component 2 soldered on the substrate 1 or on the lower substrate so that the substrate 1 can be expanded and contracted by heat cycle. The resulting distortion is alleviated, and it is possible to reduce the occurrence of cracks in the mounting solder of the large circuit component 2 and to improve the reliability.

  In addition, according to the seventh and eighth oscillators, the small circuit components 3a and 3b are arranged around the large circuit component 2 where no slit is formed, so that the expansion of the substrate 1 due to the heat cycle is achieved. The distortion caused by the shrinkage is alleviated, and it is possible to reduce the occurrence of cracks in the mounting solder of the large circuit component 2 and to improve the reliability.

  INDUSTRIAL APPLICABILITY The present invention is suitable for a crystal oscillator with a thermostatic bath that can reduce the occurrence of cracks in the mounting solder of large circuit components and improve the reliability.

  DESCRIPTION OF SYMBOLS 1 ... Board | substrate, 2 ... Large circuit component, 3a, 3b, 3c, 3d, 3e ... Slit, 4a, 4b ... Small circuit component, 10 ... Solder

Claims (11)

In a crystal oscillator with a thermostatic bath,
A circuit oscillator formed on a substrate, wherein an L-shaped slit is provided on the substrate so as to surround each of the four corners of the circuit component. In a crystal oscillator with a thermostatic bath,
For the circuit component formed on the substrate, a slit is provided in parallel on the substrate along the outside of the long side of the circuit component, and a slit for connecting the slit provided in parallel to the lower side of the circuit component is provided. A crystal oscillator with a thermostatic bath, characterized by being provided. In a crystal oscillator with a thermostatic bath,
A crystal oscillator with a thermostatic chamber, wherein a slit is provided on the substrate along the outside of the four sides of the circuit component for the circuit component formed on the substrate. In a crystal oscillator with a thermostatic bath,
A crystal oscillator with a thermostatic bath, wherein a slit is provided on the substrate along the outside of the short side of the circuit component for the circuit component formed on the substrate. In a crystal oscillator with a thermostatic bath,
A crystal oscillator with a thermostatic bath, wherein a slit is provided on the substrate along the outside of the long side of the circuit component for the circuit component formed on the substrate.   6. The crystal oscillator with a thermostat according to claim 2, wherein a small circuit component smaller than the circuit component is disposed on the substrate along the outer side of the short side of the circuit component.   5. The crystal oscillator with a thermostat according to claim 4, wherein a small circuit component smaller than the circuit component is disposed on the substrate along the outside of the long side of the circuit component. In a crystal oscillator with a thermostatic bath,
The circuit component formed on the substrate is provided with a slit on the substrate below the circuit component and along the short side or the long side of the circuit component, or along the outside of the short side and the long side. A crystal oscillator with a thermostatic bath, characterized in that small circuit components smaller than the circuit components are arranged. In a crystal oscillator with a thermostatic bath,
For a circuit component formed on a substrate, a short side portion of the circuit component is soldered and fixed to the substrate, and a slit is formed on the substrate at a lower side of the center of the circuit component in parallel with the short side. A crystal oscillator with a thermostatic bath, characterized by being provided.   The crystal oscillator with a thermostatic bath according to any one of claims 1 to 9, wherein the slit has a width of 0.1 mm or more and 1.5 mm or less.   The crystal oscillator with a thermostat according to any one of claims 1 to 9, wherein the slit has a width of 0.6 mm to 0.8 mm.

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