JP5912566B2 - Crystal oscillator with temperature chamber - Google Patents

Description

  The present invention relates to a crystal oscillator with a thermostatic chamber, and in particular, a constant temperature capable of reducing the height (thickness) size to reduce the height, simplifying the manufacturing process, and improving the frequency temperature characteristics. It relates to a crystal oscillator with a tank.

[Description of Prior Art]
The Oven Controlled Crystal Oscillator (OCXO) keeps the operating temperature of the crystal unit constant, so that a highly stable oscillation frequency can be obtained without causing a frequency change depending on the frequency temperature characteristics. Is.
The crystal resonator is housed in a thermostatic bath, and the thermostatic bath is controlled by a temperature control circuit so as to keep the temperature in the bath constant.

[Configuration of Conventional Crystal Oscillator with Thermostatic Bath: Fig. 5]
The structure of the conventional crystal oscillator with a thermostat will be described with reference to FIG. FIG. 5 is a cross-sectional explanatory view of a conventional crystal oscillator with a thermostatic bath.
As shown in FIG. 5, a conventional crystal oscillator with a thermostatic chamber is mounted on a first substrate 11 made of glass epoxy, a second substrate 12 smaller than the first substrate, and the second substrate 12. Electronic parts such as a crystal resonator 13, a power transistor 14, and a heater resistor 15 are provided.

The second substrate 12 is held by a plurality of pins (lead pins) 16 in a state of being floated from the first substrate 11 at a predetermined interval, and is fixed by solder 17 and the upper and lower substrates are electrically connected. Has been.
And the cover 20 is mounted on the 1st board | substrate 11 so that the 2nd board | substrate 12 and the electronic component mounted on it may be covered, and it has the structure sealed.

In the crystal oscillator with a thermostat having the above-described configuration, a temperature control circuit is formed by the power transistor 14, the heater resistor 15, and the like, and is controlled so as to keep the temperature of the crystal resonator constant.
In addition, by making the second substrate 12 float from the first substrate 11, heat from the heating element is hardly diffused to the outside of the OCXO, and power consumption for maintaining the temperature in the space is reduced. It is to reduce.

In the structure of the conventional crystal oscillator with a constant temperature bath shown in FIG. 5, the number of pins is large, the solder area for connecting the pins and the substrate is widened, the area for mounting electronic components is narrowed, and high-density mounting is performed. There must be.
Furthermore, although the amount of heat generated by the heater resistor 15 used as a heat source depends on the current, since the change is not linear (linear), when the ambient temperature changes, the amount of generated heat is lost and the output of the oscillator This contributes to the deterioration of frequency temperature characteristics.

[Related technologies]
In addition, as a technology related to a crystal oscillator with a thermostatic chamber, JP 2007-006270 A “Piezoelectric Oscillator” (Nippon Denpa Kogyo Co., Ltd., Patent Document 1), JP 2010-177732 A “Constant Thermoelectric Piezoelectric Oscillator” (Epson Toyocom Corporation, Patent Document 2), Japanese Utility Model Publication No. 04-91411 “Clock Oscillator” (Fujitsu General Co., Ltd., Patent Document 3), Japanese Patent Laid-Open Publication No. 2006-311696 “Constant Temperature Crystal Oscillator” (Nippon Denpa Kogyo Kogyo Co., Ltd.) Company, Patent Document 4).

  Patent Document 1 discloses a piezoelectric oscillator that includes a recess formed on the surface of a substrate and a support member fixed to the substrate, and the piezoelectric vibrator is supported by the support member in a state of being in the recess and floating from the substrate. Have been described.

  In Patent Document 2, a heating element is housed in a recess provided on the lower side of a substrate, a crystal resonator is bonded to the opening of the recess, and a temperature-sensitive element, an oscillation element, and temperature control are formed on the upper surface of the substrate. A constant temperature type piezoelectric oscillator to which an element for use is bonded is described.

Patent Document 3 describes a clock oscillator in which a recess is formed in a stem to accommodate circuit components, a ceramic substrate is mounted on the stem, and a crystal resonator is mounted thereon.
In Patent Document 4, a crystal resonator and a temperature control element are mounted on the lower side of the substrate, an oscillation circuit is mounted on the upper side, the substrate is supported by an airtight terminal on another substrate, and the whole is covered with a cover. A type of crystal oscillator is described.

JP 2007-006270 A JP 2010-177732 A Japanese Utility Model Publication No. 04-91411 JP 2006-311496 A

  However, in the conventional crystal oscillator with a thermostatic bath, since the two substrates are connected at regular intervals, the dimension in the height direction is large, making it difficult to use in a thin device, and the number of pins is large. In addition, there is a problem that the frequency temperature characteristics of the oscillator may be deteriorated due to non-linear heat generation from the heater resistance.

  In Patent Documents 1 to 4, a second substrate is mounted in close contact with an opening of a recess formed by cutting out the first substrate (base substrate) halfway without using pins. A structure in which a crystal resonator and a power transistor are mounted on the lower surface of the substrate and housed in a recess, and the upper and lower surfaces of the second substrate are electrically connected through a through hole formed in the second substrate. Not listed.

  The present invention has been made in view of the above circumstances, and can be reduced in height by eliminating pins, enabling application to a thin device, simplifying the process, and obtaining good frequency temperature characteristics. An object is to provide a crystal oscillator with a thermostatic bath.

The present invention for solving the problems of the conventional example includes a first substrate serving as a base substrate and a second substrate on which a crystal resonator is mounted, and includes a temperature sensor, a power transistor, and a heater resistor. And a temperature control circuit having a constant temperature controlled crystal oscillator, wherein the temperature control circuit includes a current limiting circuit for limiting a current flowing through the heater resistor, and a recess is formed on the upper surface of the first substrate. And the second substrate is mounted in close contact with the first substrate so as to cover the opening of the recess, and the second substrate is mounted on either the upper surface or the lower surface with the crystal resonator and the temperature. and the sensor is mounted, it is mounted a power transistor on the other side, and a crystal oscillator and the power transistor, while being mounted in a position facing each other across the second substrate, to connect the upper and lower surfaces through hole, in the quartz crystal resonator And a plurality formed in a region sandwiched between the power transistor, the through hole is in contact with the crystal oscillator and the power transistor, one recess of installed quartz oscillator or a power transistor on a second substrate It is characterized by being stored in.

  Further, according to the present invention, in the crystal oscillator with a thermostatic bath, the concave portion is formed near one short side of the first substrate, and the second substrate is not mounted near the other short side. The heater resistor is mounted in a region where the second substrate near the other short side is not mounted.

  Moreover, the present invention is characterized in that, in the crystal oscillator with a thermostat, a heater resistor is mounted on the upper surface of the second substrate.

  In addition, the present invention is characterized in that in the crystal oscillator with a thermostatic bath, the crystal resonator is of a surface mount type.

  The present invention is also characterized in that, in the above-described crystal oscillator with a thermostat, the crystal resonator is a lead type.

  Moreover, the present invention is characterized in that in the crystal oscillator with a thermostatic bath, the recess is formed by hollowing out the first substrate.

According to the present invention, the temperature control circuit includes a first substrate serving as a base substrate and a second substrate on which a crystal resonator is mounted, and the temperature is controlled by a temperature control circuit having a temperature sensor, a power transistor, and a heater resistor. A crystal oscillator with a thermostatic bath controlled to be constant, wherein the temperature control circuit includes a current limiting circuit that limits a current flowing through the heater resistor, a recess is formed on the upper surface of the first substrate, and an opening of the recess is formed. The second substrate is mounted in close contact with the first substrate so as to cover, and the second substrate has the crystal resonator and the temperature sensor mounted on either the upper surface or the lower surface, and the other surface. the power transistor is mounted, and a quartz oscillator and the power transistor, while being mounted in a position facing each other across the second substrate, through holes connect the upper and lower surfaces are crystal oscillator and the power transistor Between A plurality formed in a region, a constant temperature through hole is in contact with the crystal oscillator and the power transistor, either one of the on-board crystal oscillator or the power transistor on the second substrate is stored in the recess Since it is a crystal oscillator with a tank, it eliminates the need for pins to connect the first substrate and the second substrate, greatly reduces the height dimension and expands applications, and simplifies the manufacturing process. By controlling the heat source linearly, the frequency temperature characteristics of the oscillator can be improved , and the heat from the power transistor is transmitted to the crystal unit through a plurality of through-holes. By radiating from the cover to the space, the space in which the crystal resonator is stored can be efficiently heated, and power consumption can be reduced.

  According to the present invention, the recess is formed near one short side of the first substrate, and the second substrate is provided near the other short side, and the other substrate is provided with the second substrate. Since the above-mentioned oven controlled crystal oscillator with a heater resistor mounted in a region where the second substrate near the short side is not mounted, the heater resistor can be mounted as far as possible from the crystal resonator, The effect of non-linear heat generation can be reduced to improve the frequency temperature characteristics of the oscillator, and the size of the second substrate can be reduced to reduce the cost.

  In addition, according to the present invention, the heater resistor is the above-mentioned crystal oscillator with a thermostatic bath mounted on the upper surface of the second substrate. Therefore, by mounting all the electronic components on the second substrate, This eliminates the need for a substrate mounting process and simplifies the manufacturing process.

  Further, according to the present invention, since the concave portion is the crystal oscillator with a thermostatic chamber formed by hollowing out the first substrate, it is formed when a plurality of members are bonded to the side surface of the first substrate. There is an effect of preventing disconnection of electrodes and terminals formed on the side surfaces.

It is sectional explanatory drawing of the crystal oscillator with a thermostat which concerns on the 1st Embodiment of this invention, (a) has shown 1st structure, (b) has shown 2nd structure. It is a circuit diagram of the temperature control circuit of the 1st crystal oscillator with a thermostat. It is sectional explanatory drawing of the crystal oscillator with a thermostat which concerns on the 2nd Embodiment of this invention. It is sectional explanatory drawing of the crystal oscillator with a thermostat which concerns on the 3rd Embodiment of this invention, (a) has shown the 1st structure, (b) has shown the 2nd structure. It is sectional explanatory drawing of the conventional crystal oscillator with a thermostat.

Embodiments of the present invention will be described with reference to the drawings.
[Outline of the embodiment]

  The crystal oscillator with a thermostatic bath according to the embodiment of the present invention includes a current control circuit for limiting a current to the heater resistor in the temperature control circuit, the heat source is a power transistor, and the first substrate serving as a base substrate is provided. A recess is formed by hollowing out, a second substrate is mounted on the opening of the recess, a crystal resonator and a temperature sensor are mounted on either the upper surface or the lower surface of the second substrate, A power transistor is mounted on the other surface of the second substrate, and the upper surface and the lower surface of the second substrate are electrically connected via a through hole formed in the second substrate, It has a cover that covers the entire surface, and it can be mounted on a thin device by reducing the height by eliminating the need for pins, and can be used for a wide range of applications, and the mounting area for components can be expanded, simplifying the manufacturing process. As well as You can control the heat source linearly, in which the frequency-temperature characteristic of the oscillator can be improved.

  Further, in the crystal oscillator with a thermostatic bath according to the embodiment of the present invention, the recess is further formed in a region near one of the short sides of the first substrate, and the recess of the first substrate is formed. The heater resistor is mounted at a position as far as possible from the recess of the non-existing region, and the influence of nonlinear heat from the heater resistor can be reduced to improve the frequency temperature characteristics of the oscillator.

  Further, in the crystal oscillator with a thermostatic bath according to the embodiment of the present invention, the crystal resonator is a lead type including a surface mount type or a round blank, and a low-profile crystal resonator is used according to the application. Therefore, it can be mounted on a thin device, and the frequency temperature characteristics of the oscillator can be improved.

[First Embodiment: FIG. 1]
A constant-temperature bath crystal oscillator according to a first embodiment of the present invention will be described with reference to FIG. 1A and 1B are cross-sectional explanatory views of a crystal oscillator with a thermostatic bath according to a first embodiment of the present invention. FIG. 1A shows a first configuration, and FIG. 1B shows a second configuration.
[First Configuration Example: FIG. 1A]
First, a description will be given with reference to FIG.
As shown to Fig.1 (a), the 1st structure of the crystal oscillator with a thermostat (1st crystal oscillator with a thermostat) which concerns on the 1st Embodiment of this invention is the 1st board | substrate 31, The second substrate 32, the cover 30, and a plurality of electronic components 15 such as a crystal resonator 13, a power transistor 14, and a heater resistor are included.
The crystal resonator 13 of the first crystal oscillator with a thermostat is of a surface mount type.

The first substrate 31 is a base substrate and is made of glass epoxy resin (glass epoxy) or ceramic.
As a feature of the first crystal oscillator with a thermostat, a recess 33 is formed on the upper surface of the first substrate 31. Here, the concave portion 33 is formed by cutting out (cutting) the upper surface portion of the first substrate 31 halfway by etching or the like.
By forming the recess 33 by cutting out the first substrate 31, no step or junction is formed on the side surface of the first substrate 31 on which the terminal (wiring) is formed, and disconnection of the terminal can be prevented. Is.

The position where the recess 33 is formed is not at the center of the first substrate 31 but at a position near one of the short sides. In the example of FIG. 1, the recess 33 is formed near the short side on the left side of the first substrate 31.
Further, the size of the recess 33 is set to a size that can accommodate the crystal resonator 13 in the first configuration.

  That is, in the first crystal oscillator with a thermostatic bath, the concave portion 33 is formed on the substantially half surface of the first substrate 31, and the wiring or the like is formed on the other half surface, which is an area where electronic components can be mounted. . Furthermore, electrodes are also formed on the side and bottom surfaces. No wiring or electrodes are formed inside the recess 33.

And the 2nd board | substrate 32 which consists of glass epoxy etc. is mounted so that the opening part of the recessed part 33 may be covered. The size of the second substrate 32 is larger than the opening of the recess 33 and smaller than the first substrate 31. The first substrate 31 and the second substrate 32 are directly bonded by solder or adhesive at the contact surface.
Thereby, in the crystal oscillator with a thermostat according to the present embodiment, the pins for connecting the first substrate and the second substrate are unnecessary, and the dimension in the height direction can be greatly reduced.

  Wiring is formed on the upper surface and the lower surface of the second substrate 32, electronic components can be mounted on both surfaces, and a through hole 34 that connects the upper surface and the lower surface of the second substrate 32 is formed. As will be described later, a plurality of through holes 34 are formed in a region where the crystal resonator 13 and the power transistor 14 are mounted facing each other.

  In addition, since the size of the second substrate 32 is determined by the size of the concave portion 33 formed in the first substrate 31, in the first crystal oscillator with a thermostatic bath, the concave portion 33 is about half of the first substrate. The second substrate 32 is made to be a minimum size.

  In other words, in the first crystal oscillator with a thermostat, the second substrate 32 is equipped with the crystal resonator 13 and the temperature sensor 18 on one surface and the power transistor 14 on the other surface, and the other components are the first. By mounting on the upper surface of the substrate 31, the second substrate 32 can be formed small and the cost can be reduced.

And the cover 30 is mounted on the 1st board | substrate 31 so that the electronic component etc. on the 1st board | substrate 31 and the 2nd board | substrate 32 may be covered, and it has the sealed structure.
In the first crystal oscillator with a thermostat, since the two substrates are directly bonded to each other without using pins as compared with the conventional configuration shown in FIG. 5, the dimension in the height direction can be reduced. Is.

As shown in FIG. 1A, in the first configuration example of the first crystal oscillator with a thermostat, the crystal resonator 13 is mounted on the lower surface of the second substrate 32, and the power transistor 14 is the second. It is mounted on the upper surface of the substrate 32. The temperature sensor 18 is mounted on the lower surface of the second substrate 32.
That is, in the first configuration example of the first crystal oscillator with a thermostat, the crystal resonator 13 and the temperature sensor 18 are housed in a small space of the recess 33 and the space is closed by the second substrate 32. It has become.

  The crystal resonator 13 and the GND terminal or NC terminal of the temperature sensor 18 are connected by a Cu (copper) wiring pattern. Since Cu has good thermal conductivity, the temperature sensor 18 can accurately detect the temperature of the crystal unit 13 and can perform high-precision temperature control to obtain good frequency temperature characteristics.

  The electronic components mounted on the upper and lower surfaces of the second substrate 32 include wirings (and electrodes) on the upper and lower surfaces of the second substrate 32, wirings formed on the side surfaces of the second substrate 32, and the first components. The electrodes are connected to terminals formed on the back surface of the first substrate 31 through electrodes (terminals) formed on the top and side surfaces of the substrate 31.

  Further, in the first crystal oscillator with a thermostat, a temperature control circuit is provided with a current limiting circuit for limiting the current flowing through the heater resistor 15, and the power transistor 14 is used as a heat source, thereby linearly controlling the amount of heat generated. It is possible to obtain a good temperature frequency characteristic. The temperature control circuit will be described later.

  The crystal resonator 13 and the power transistor 14 are not electrically connected, but are mounted so as to face each other with the second substrate 32 interposed therebetween, and the heat generated in the power transistor 14 is The crystal resonator via a plurality of through holes 34 formed between the crystal resonator 31 and the power transistor 14 and a ground terminal formed on the bottom surface of the crystal resonator 13 (upper side in FIG. 1A). Therefore, the entire concave portion 33 can be efficiently warmed.

Further, since the heater resistor 15 also generates a little heat, in the first crystal oscillator with a thermostat, the heater resistor 15 is mounted on the upper surface of the first substrate 31 near the short side far from the recess 33. Yes.
That is, in the first configuration example, the heat source is the power transistor 14 and the amount of heat generation is controlled linearly, and the heater resistor 15 is mounted as far as possible from the recess 33 in which the crystal resonator 13 is stored. Thus, the amount of heat generated can be accurately controlled in accordance with the detected temperature, and the influence of non-linear heat generation on the crystal resonator 13 can be suppressed to improve the frequency temperature characteristic of the oscillator output. .

[Second Configuration Example: FIG. 1B]
Next, the 2nd structure of the 1st thermostat crystal oscillator is demonstrated using FIG.1 (b).
As shown in FIG. 1B, in the second configuration of the first crystal oscillator with a thermostat, the configurations of the first substrate 31, the second substrate 32, and the cover 30 are the same as those shown in FIG. However, the method of mounting the electronic component is different from that of the first configuration.

As shown in FIG. 1B, in the second configuration, the crystal resonator 13 and the temperature sensor 18 are mounted on the upper surface of the second substrate 32, and the power transistor 14 is mounted on the lower surface. In the second configuration, the recess 33 is formed to a size that can accommodate the power transistor 14.
As in the first configuration, the heater resistor 15 is mounted near the short side of the first substrate 31 farther from the recess 33.
As a result, the distance between the crystal resonator 13 and the heater resistor 15 is increased, the influence of the heat of the heater resistor 15 on the crystal resonator 13 is reduced, and the oscillator output has good frequency temperature characteristics.

  Further, since the crystal unit 13 and the power transistor 14 are bonded to the front and back surfaces of the second substrate 32, the heat generated in the power transistor 14 is transferred to the through holes 34 and the bottom surface of the crystal unit 13 ( The entire space that is transmitted to the metal cover of the crystal unit 13 through the ground terminal formed in FIG. 1B and covered with the cover 30 through the side surface and the upper surface of the cover of the crystal unit 13. Can be efficiently heated, and power consumption is reduced.

[Temperature control circuit: Fig. 2]
Next, a temperature control circuit of the first crystal oscillator with a thermostat will be described with reference to FIG. FIG. 2 is a circuit diagram of a temperature control circuit of the first thermostat crystal oscillator.
As shown in FIG. 2, in the temperature control circuit of the first crystal oscillator with a thermostat, the power supply voltage DC is applied to one end of the heater resistor (HR) 41, and the other end of the heater resistor 41 serves as the power transistor 14. It is connected to the source of a MOSFET (P channel MOSFET) 42. Instead of the MOSFET 42, a PNP type bipolar power transistor may be used.
The drain of the MOSFET 42 is grounded to the ground (GND).

A power supply voltage DC is applied to one end of the resistor R1, the other end of the resistor R1 is connected to one end of a thermistor (TH) 43 as a temperature sensor, and the other end of the thermistor 43 is grounded.
The power supply voltage DC is applied to one end of the resistor R2, the other end of the resistor R2 is connected to one end of the resistor R3, and the other end of the resistor R3 is grounded to GND.

A point between the other end of the resistor R1 and one end of the thermistor 43 is connected to one input terminal (− terminal) of the operational amplifier 44, and a point between the other end of the resistor R2 and one end of the resistor R3. Are connected to the other input terminal (+ terminal) of the operational amplifier 44.
The output terminal of the operational amplifier 44 is connected to the gate of the MOSFET 42.

Further, the other end of the heater resistor 41 (source side of the MOSFET 42) is connected to an output terminal of the operational amplifier 44 (gate side of the MOSFET 42) via a current limit circuit (described as “current limit” in the figure) 45.
The current limiting circuit 45 is configured by a transistor or the like, and limits the current flowing through the heater resistor 41. With this, the heat source is only a power transistor, and the amount of generated heat can be controlled linearly.

[Effect of the first embodiment]
According to the crystal oscillator with a thermostatic bath according to the first embodiment of the present invention, the current control circuit 45 for limiting the current flowing through the heater resistor 15 is provided in the temperature control circuit, and one short circuit of the first substrate 31 is provided. A recess 33 is formed in the upper surface near the side by hollowing, and the second substrate 32 is mounted so as to cover the opening of the recess 33, and surface mounting is performed on either the upper surface or the lower surface of the second substrate 32. The crystal oscillator 13 and the temperature sensor 18 are mounted, the power transistor 14 is mounted on the other surface, the upper surface and the lower surface of the second substrate 32 are connected by a through hole 34, and the first substrate 31 Since the heater resistor 15 is mounted on the upper surface near the other short side and the whole is sealed by the cover 30, it is possible to mount it on a thin device with a low profile by using no pin, Eliminates the area occupied by the rice field, facilitates component mounting, simplifies the manufacturing process, reduces costs, and reduces the effects of non-linear heat generation to obtain good frequency temperature characteristics. There is an effect that can.
In addition, there is an effect that a base station of a wireless communication system in which the thermostatted crystal oscillator is mounted or a network device can be molded thinly.

  In addition, according to the first crystal oscillator with a thermostatic chamber, the size of the second substrate 32 is made small enough to mount the crystal resonator 13 and the temperature sensor 18 on one surface, thereby reducing the cost. There is an effect that can be done.

  In particular, in the first configuration of the first crystal oscillator with a thermostat, the crystal resonator 13 and the temperature sensor 18 are stored together in a small space. Can be detected accurately, and the temperature can be controlled with high accuracy to achieve better frequency temperature characteristics.

[Second Embodiment: FIG. 3]
Next, a crystal oscillator with a thermostatic bath according to a second embodiment of the present invention will be described with reference to FIG. FIG. 3 is a cross-sectional explanatory view of a crystal oscillator with a thermostatic bath according to a second embodiment of the present invention.
A crystal oscillator with a thermostat (second crystal oscillator with a thermostat) according to the second embodiment of the present invention has substantially the same configuration as the second configuration of the crystal oscillator with the first thermostat described above. However, the difference is that a lead type crystal resonator using a round crystal blank is used instead of the surface mount type as the crystal resonator.

As shown in FIG. 3, in the second crystal oscillator with a thermostat, the recess 33 is cut out on the upper surface of the first substrate 31 made of glass epoxy or ceramic, like the crystal oscillator with the first thermostat. A second substrate 32 that is formed and formed of glass epoxy or the like so as to cover the opening at the top of the recess 33 is mounted and bonded to the first substrate.
Metal wiring is formed on both surfaces of the second substrate 32, and the upper and lower surfaces are electrically connected by a plurality of through holes 34.

On the upper surface of the second substrate 32, a lead type crystal resonator 13 'having a round blank is mounted.
The crystal resonator 13 ′ is held horizontally such that the main surface of the round crystal blank is substantially parallel to the upper surface of the second substrate 32, and the back surface is bonded to the electrode on the second substrate 32 by soldering. Yes. Further, the tip portions of the two lead terminals of the crystal unit 13 ′ are bent downward by about 90 degrees and fixed to the wiring on the upper surface of the second substrate 32 by soldering.

Further, the temperature sensor 18 is mounted on the upper surface of the second substrate 32, and the power transistor 14 is mounted on the lower surface.
Further, a heater resistor 15 is mounted near the short side far from the recess 33 of the first substrate 31.
The whole is sealed by the cover 30.

  Further, the temperature control circuit of the second crystal oscillator with a thermostat is the same as the temperature control circuit of the first crystal oscillator with a thermostat shown in FIG. 2, and the current flowing through the heater resistor 15 using the current limiting circuit. The amount of heat generation is controlled linearly by using only the power transistor 14 as a heat source.

  As a result, in the second crystal oscillator with a thermostat, a lead-type crystal resonator having a round blank is used to achieve a low profile and a thermostat with a good temperature-frequency characteristic. It can be realized.

[Effect of the second embodiment]
According to the crystal oscillator with a thermostatic bath according to the second embodiment of the present invention, the temperature control circuit is provided with the current limiting circuit 45 that limits the current flowing through the heater resistor 15, and any one of the first substrates 31 is provided. A recess 33 is formed by hollowing out on the upper surface near the short side, and the second substrate 32 is mounted so as to cover the opening of the recess 33, and on either the upper surface or the lower surface of the second substrate 32, A lead type crystal resonator 13 ′ having a temperature sensor 18 and a round blank is mounted substantially parallel to the second substrate 32, the power transistor 14 is mounted on the other surface, and the upper surface of the second substrate 32 Since the lower surface is connected by the through hole 34, the heater resistor 15 is mounted on the upper surface near the short side far from the recess 33 of the first substrate 31, and the whole is sealed by the cover 30. Using a lead-type crystal unit with a mold blank, it is possible to reduce the height and mount it on a thin device, simplify the manufacturing process, reduce the cost, and use only the power transistor 14 as the heat source. It is possible to control the heat generation linearly, further reduce the influence of non-linear heat generation, and obtain an excellent frequency temperature characteristic.

[Third Embodiment: FIG. 4]
Next, a crystal oscillator with a thermostatic bath according to a third embodiment of the present invention will be described with reference to FIG. 4A and 4B are cross-sectional explanatory views of a crystal oscillator with a thermostatic bath according to a third embodiment of the present invention. FIG. 4A shows a first configuration, and FIG. 4B shows a second configuration.
As shown in FIGS. 4A and 4B, the crystal oscillator with a thermostatic chamber (third crystal oscillator with a thermostatic chamber) according to the third embodiment of the present invention is the first made of glass epoxy or ceramic. The substrate 31 and the second substrate 32, a cover 30, a surface-mounted crystal resonator 13, a power transistor 14, a heater resistor 15, and the like.

The third thermostatted crystal oscillator includes a concave portion 33 formed by cutting out on the upper surface of the first substrate 31, and the second substrate 32 is mounted in close contact with the first substrate so as to cover the opening. Has been.
In the third crystal oscillator with a thermostat, the size of the concave portion 33 is made larger than that of the first crystal oscillator with a thermostat, and the size of the second substrate 32 is also increased accordingly.

That is, in the third crystal oscillator with a thermostatic bath, electronic components such as the crystal resonator 13, the power transistor 14, the heater resistor 15, and the temperature sensor 18 are all mounted on the second substrate.
As a result, the first substrate is completed only by the step of forming the recess 33 by etching or the like and the step of forming the metal wiring pattern on the top surface, the side surface, and the bottom surface, and the step of mounting the electronic component is unnecessary. The manufacturing process can be simplified.

As shown in FIG. 4A, the first configuration of the third crystal oscillator with a thermostatic bath has the crystal resonator 13 and the temperature sensor 18 mounted on the lower surface of the second substrate 32, and the power on the upper surface. A transistor 14 and a heater resistor 15 are mounted. The crystal resonator 13 and the temperature sensor 18 mounted on the lower surface are stored in the recess 33 of the first substrate 31, and the recess 33 is sealed by the second substrate 32.
The heater resistor 15 is mounted as far as possible from the crystal resonator 13.
The second substrate 32 has a through hole 34 that connects the upper surface and the lower surface.

Further, the third crystal oscillator with a thermostat has a temperature control circuit similar to that of the first crystal oscillator with a thermostat, and the heat source is only the power transistor 14 and the heat generation amount is linearly controlled with respect to the temperature change. To do.
Furthermore, since the heater resistor 15 is mounted as far as possible from the crystal unit 13 on the surface opposite to the crystal unit 13, the third temperature controlled crystal oscillator has a good temperature frequency. Characteristics are obtained.

  Also in the third thermostat crystal oscillator, the crystal resonator 13 and the power transistor 14 are mounted so as to face each other with the second substrate 32 interposed therebetween, so that heat from the power transistor 14 can be transferred to the through hole 34 and The space in which the crystal resonator 13 is mounted can be efficiently heated by dissipating heat through the metal cover of the crystal resonator 13, and there is an effect of reducing power consumption.

  Further, as shown in FIG. 4B, the second configuration of the third crystal oscillator with a thermostatic bath has the power transistor 14 mounted on the lower surface of the second substrate 32 and the crystal resonator 13 on the upper surface. A temperature sensor 18 and a heater resistor 15 are mounted.

  In FIG. 4, the crystal resonator 13 and the power transistor are mounted at the center of the second substrate, but may be mounted closer to one of the short sides. By mounting the heater resistor 15 near the side, the distance between the crystal resonator 13 and the heater resistor 15 can be increased, and the influence of non-linear heat generation can be further reduced.

[Effect of the third embodiment]
According to the crystal oscillator with a thermostatic bath according to the third embodiment of the present invention, the temperature control circuit is provided with the current limiting circuit 45 that limits the current flowing through the heater resistor 15, and the upper surface of the first substrate 31 is The concave portion 33 is formed by hollowing out, the second substrate 32 is mounted so as to cover the opening of the concave portion 33, and the crystal resonator 13 and the temperature sensor 18 are formed on either the upper surface or the lower surface of the second substrate 32. And the power transistor 14 is mounted on the other surface, the upper surface and the lower surface of the second substrate 32 are connected by the through hole 34, and the whole is sealed by the cover 30. Can be mounted on a thin device and can be mounted on only the second substrate, thereby simplifying the manufacturing process and reducing the cost. Fever and linear control possible as an effect of it is possible to obtain good frequency-temperature characteristics.

  INDUSTRIAL APPLICABILITY The present invention is suitable for a crystal oscillator with a thermostatic bath that can be reduced in height, can be mounted on a thin device, can simplify a manufacturing process, and can have good frequency temperature characteristics.

  DESCRIPTION OF SYMBOLS 11, 31 ... 1st board | substrate, 12, 32 ... 2nd board | substrate, 13 ... Crystal oscillator, 14 ... Power transistor, 15, 41 ... Heater resistance, 16 ... Pin, 17 ... Solder, 18 ... Temperature sensor, 20,30 ... Cover, 33 ... Recess, 34 ... Through hole, 42 ... P-channel MOSFET, 43 ... Thermistor, 44 ... Operational amplifier, 45 ... Current limit circuit

Claims (6)

A constant temperature that includes a first substrate as a base substrate and a second substrate on which a crystal resonator is mounted, and the temperature is controlled to be constant by a temperature control circuit having a temperature sensor, a power transistor, and a heater resistor. A crystal oscillator with a tank,
The temperature control circuit includes a current limiting circuit that limits a current flowing through the heater resistor,
A recess is formed on the upper surface of the first substrate, and the second substrate is mounted in close contact with the first substrate so as to cover the opening of the recess,
The second substrate has the crystal resonator and the temperature sensor mounted on either the upper surface or the lower surface, the power transistor mounted on the other surface, the crystal resonator and the power transistor, but the while being mounted on the second position opposite to each other with respect to the substrate, the top surface and through-hole that connects with said lower surface, a plurality formed in a region sandwiched between the crystal oscillator and the power transistor The through hole is in contact with the crystal resonator and the power transistor,
One of the crystal resonator and the power transistor mounted on the second substrate is housed in the recess, and the crystal oscillator with a thermostatic bath is characterized in that:   A recess is formed near one short side of the first substrate, and a second substrate near the other short side is provided with a region where the second substrate is not mounted near the other short side. The crystal oscillator with a thermostat according to claim 1, wherein a heater resistor is mounted in a region where the is not mounted.   The crystal oscillator with a thermostat according to claim 1, wherein the heater resistor is mounted on the upper surface of the second substrate.   The crystal oscillator with a thermostat according to any one of claims 1 to 3, wherein the crystal resonator is of a surface mount type. Crystal oscillator, according to claim 1 or any ovenized crystal oscillator according to 3, characterized in that a lead type.   The crystal oscillator with a thermostat according to any one of claims 1 to 5, wherein the concave portion is formed by hollowing out the first substrate.

Images