JP2005244671A - Temperature compensated crystal oscillator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a temperature compensated crystal oscillator which is easily handled and is excellent in productivity and has stable circuit characteristics. <P>SOLUTION: In the temperature compensated crystal oscillator, a rectangular container 1 accommodating a crystal vibration element 5 in its inside and a plurality of mounting legs 12 are fixed on the bottom surface of a supporting base, and an IC element 7 for outputting an oscillation signal corresponding to the oscillation frequency of the crystal vibration element 5 while correcting the signal on the basis of temperature compensation data is mounted on the top surface of the supporting base 6. In this oscillator, a writing control terminal 11 consisting of metal posts for writing the temperature compensation data into the IC element 7 is attached, so that its external side surface is exposed and the terminal is spaced from the mounting leg portions 12 on a region where no mounting leg 12 exists in the external periphery of the bottom surface of the supporting base 6. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a temperature-compensated crystal oscillator used as a timing device for communication equipment and electronic equipment.

  Conventionally, a temperature-compensated crystal oscillator has been used as a timing device for portable communication devices and the like.

  As such a conventional temperature-compensated crystal oscillator, for example, as shown in FIG. 7, a container body 51 in which a crystal resonator element is accommodated is fixed on a support base, and a crystal vibration is provided on the lower surface of the support base 52. There is known a structure in which an IC element that outputs an oscillation signal corresponding to the oscillation frequency of the element while being corrected based on temperature compensation data is attached, and a frame 53 that surrounds the IC element is attached. (For example, refer to Patent Document 1).

  The container body 51 and the support base 52 are usually made of a ceramic material such as alumina ceramics, and wiring conductors are formed inside and on the surface, and are manufactured by employing a conventionally known green sheet laminating method or the like. Yes. A plurality of bonding electrodes are provided at corresponding positions on the lower surface of the container body 51 and the upper surface of the support base 52, and these bonding electrodes are bonded to each other via a conductive bonding material. Thus, the container body 51 was fixed to the upper surface of the support base 52.

Further, a temperature compensation circuit for correcting the oscillation output of the temperature compensated crystal oscillator based on the temperature compensation data created according to the temperature characteristics of the crystal resonator element is provided inside the IC element. In order to store such temperature compensation data in the memory in the IC element, a write control terminal 54 is provided on the outer surface of the support base 51. After assembling the crystal oscillator, the temperature compensation is applied to the write control terminal 54. The temperature compensation data is stored in the memory in the IC element by inputting the temperature compensation data to the IC element by applying the probe needle of the data writing device.
JP 2000-77943 A

  However, in the above-described conventional temperature-compensated crystal oscillator, a write control terminal 54 for writing temperature compensation data is provided on the outer surface of the support base 52. In order to manufacture the support base 52, a support is provided. A film-like writing control terminal 54 is deposited by making a through hole in a ceramic mother substrate from which the substrate 52 is cut, applying a conductive paste to the inner surface thereof, baking it, or applying metal plating. Therefore, the productivity of the temperature-compensated crystal oscillator is significantly reduced due to the necessity of such a complicated processing process.

  Further, in the above-described conventional temperature compensated crystal oscillator, the IC element is attached to the lower surface of the support base 51. Therefore, when the temperature compensated crystal oscillator is mounted on an external wiring board such as a mother board, the IC element is It is arranged opposite to the wiring pattern of the external wiring board in a state of being close to the wiring pattern. In this case, stray capacitance is generated between the wiring pattern in the IC element and the wiring pattern on the external wiring board, or it is incorporated into the IC element due to the influence of noise generated from the external wiring board side. There was a drawback that the characteristics of the electronic circuit became unstable.

  The present invention has been devised in view of the above drawbacks, and an object of the present invention is to provide a temperature compensated crystal oscillator that is easy to handle, excellent in productivity, and stable in circuit characteristics.

The temperature-compensated crystal oscillator according to the present invention fixes a rectangular container body containing a crystal resonator element and a plurality of mounting legs to the lower surface of the support base, and the crystal vibration on the upper surface of the support base. A temperature compensated crystal oscillator equipped with an IC element that outputs an oscillation signal corresponding to the oscillation frequency of the element while correcting the oscillation signal based on temperature compensation data,
A write control terminal made of a metal post for writing temperature compensation data to the IC element is exposed in an outer peripheral area of the lower surface of the support base in an area where the mounting leg does not exist. It is characterized by being attached in a separated state.

  The temperature-compensated crystal oscillator according to the present invention is characterized in that the mounting leg is composed of four metal posts attached to the four corners of the lower surface of the support base.

  Furthermore, the temperature compensated crystal oscillator according to the present invention covers the periphery of the container body with a resin material, and extends the outer peripheral portion of the resin material to the outer peripheral portion of the support base, and this extended portion is mounted adjacently. The gap between the leg portions and between the mounting leg portion and the write control terminal is filled.

  Furthermore, the temperature compensated crystal oscillator according to the present invention is characterized in that the lower end of the write control terminal is positioned above the lower end of the mounting leg.

  The temperature compensated crystal oscillator according to the present invention is such that a write control terminal for writing temperature compensation data to an IC element is formed by a metal post and the outer side surface of the write control terminal is exposed. Thus, when assembling the temperature compensated crystal oscillator, the temperature compensated crystal oscillator can be manufactured simply by attaching the write control terminal made of a metal post to a predetermined position on the lower surface of the support base. Since no complicated processing process is required as in the case of forming a film-like write control terminal on the outer surface of the support base like the temperature compensated crystal oscillator, the productivity of the temperature compensated crystal oscillator is improved. It becomes possible.

  Further, according to the temperature compensated crystal oscillator of the present invention, the IC element is mounted on the upper surface side of the support base, that is, the main surface opposite to the mounting surface of the temperature compensated crystal oscillator on the external wiring board. Therefore, the IC element is sufficiently separated from the external wiring board to prevent stray capacitance from being generated between the wiring pattern of the external wiring board and the wiring pattern in the IC element, and noise generated from the external wiring board. Can effectively prevent the IC element from being affected, and the circuit characteristics of the temperature compensated crystal oscillator can be stabilized.

  Furthermore, according to the temperature-compensated crystal oscillator of the present invention, the periphery of the container body is covered with the resin material, the outer peripheral portion of the resin material is extended to the outer peripheral portion of the support base, and the extended portion is mounted adjacently. By filling the gaps between the legs and between the mounting legs and the write control terminals, the resin material reinforces the attachment strength to the support body such as the container body, the write control terminals, and the mounting legs. Therefore, the mechanical strength of the temperature compensated crystal oscillator can be maintained high.

  Furthermore, according to the temperature compensated crystal oscillator of the present invention, since the lower end of the write control terminal is positioned above the lower end of the mounting leg, when the temperature compensated crystal oscillator is mounted on the motherboard, the motherboard When a large stray capacitance is generated between the wiring or the like and the write control terminal, or when a temperature-compensated crystal oscillator is mounted on the motherboard by soldering or the like, a part of the melted solder becomes the write control terminal. Inconveniences such as contact and short circuit are effectively prevented, and there is an advantage that the temperature compensated crystal oscillator can be handled easily.

  Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

  1 is a perspective view showing an embodiment of a temperature compensated crystal oscillator according to the present invention, FIG. 2 is a cross-sectional view of the temperature compensated crystal oscillator of FIG. 1, and the temperature compensated crystal oscillator shown in these figures has an internal structure. The rectangular container body 1 housing the crystal resonator element 5, the mounting leg 12 and the write control terminal 11 are fixed to the lower surface of the support base 6, and the IC element 7 and The electronic component element 14 is attached.

  FIG. 3 is a perspective view of the container body 1. The container body 1 includes, for example, a substrate 2 made of a ceramic material such as glass-ceramic and alumina ceramic, and a seal made of a metal such as 42 alloy, Kovar, or phosphor bronze. The ring 3 and the lid 4 made of the same metal as the seal ring 3 are formed by attaching the seal ring 3 to the upper surface of the substrate 2 and placing and fixing the lid 4 on the upper surface. Then, the crystal resonator element 5 is mounted on the upper surface of the substrate 2 located inside the seal ring 3.

  The container body 1 is for hermetically sealing the quartz resonator element 5 in its interior, specifically, in a space surrounded by the upper surface of the substrate 2, the inner surface of the seal ring 3, and the lower surface of the lid body 4. A pair of mounting pads connected to the vibration electrode of the crystal resonator element 5 is provided on the upper surface of the substrate 2, and a mounting leg 12 or an IC element 7 described later is electrically connected to the lower surface of the substrate 2. A plurality of bonding electrodes 9 to be connected are provided, and these pads are electrically connected to each other through wiring conductors on the substrate surface or via-hole conductors embedded in the substrate. Has been.

  When the substrate 2 of the container body 1 is made of a ceramic material such as glass-ceramic, for example, a wiring conductor is formed on the surface of a ceramic green sheet obtained by adding and mixing an appropriate organic solvent to the ceramic material powder. The conductor paste to be manufactured is applied by conventionally known screen printing or the like, and a plurality of the pastes are laminated and press-molded, followed by firing at a high temperature.

  The seal ring 3 and the lid body 4 of the container body 1 are manufactured by forming a metal such as 42 alloy into a predetermined shape by using a conventionally known metal processing method, and the obtained seal ring 3 is attached to the substrate 2. After brazing the conductor layer previously deposited on the upper surface, and subsequently mounting and fixing the crystal resonator element 5 on the upper surface of the substrate 2 using a conductive adhesive, the above-described lid body 4 is conventionally known. The container body 1 is assembled by joining to the upper surface of the seal ring 3 by resistance welding or the like. In this way, when the seal ring 3 and the lid 4 are joined by resistance welding, a Ni plating layer, an Au plating layer, or the like is previously deposited on the surfaces of the seal ring 3 and the lid 4.

  On the other hand, the quartz crystal vibrating element 5 accommodated in the container body 1 is formed by attaching and forming a pair of vibrating electrodes on both main surfaces of a crystal piece cut along a predetermined crystal axis, and a variable voltage from the outside. Is applied to the quartz piece via a pair of vibrating electrodes, thickness shear vibration is caused at a predetermined frequency.

  The crystal resonator element 5 is mounted on the upper surface of the substrate 2 by electrically connecting a pair of vibration electrodes to a corresponding mounting pad on the upper surface of the substrate via a conductive adhesive, whereby the crystal resonator element 5 and the container are mounted. Electrical and mechanical connections with the body 1 are made simultaneously.

  Here, if the lid 4 of the container body 1 is electrically connected to the mounting legs for the ground terminals arranged on the lower surface of the support base via the wiring conductors of the container body 1 and the support base 6, the use thereof At that time, since the lid 4 is grounded, a shielding function is provided, so that the crystal resonator element 5 and the IC element 7 to be described later can be protected better than unnecessary electrical action from the outside. Therefore, the lid body 4 of the container body 1 is preferably connected to the mounting leg for the ground terminal via the container body 1 and the wiring conductor of the support base 6.

  The support base 6 to which the container body 1 is attached has a substantially rectangular shape. As shown in FIG. 4, a plurality of mounting legs 12 and a plurality of writing controls are provided along the outer periphery of the lower surface. A terminal 11 is attached. In the present embodiment, four mounting legs 12 are attached and erected in one-to-one correspondence with the four corners of the lower surface of the support base, and are sandwiched between the mounting legs 12. A container body 1 is mounted. The container body 1 is mounted on the lower surface of the support base such that one side of the outer periphery thereof is parallel to one side of the outer periphery of the support base 6.

  The support base 6 is used for mounting an IC element 7 to be described later on its upper surface, and for attaching the container body 1, the write control terminal 11, the mounting leg 12 and the like on its lower surface. It is made of a resin material such as epoxy resin, polycarbonate, epoxy resin or polyimide resin, or a ceramic material such as glass-ceramic or alumina ceramic, and is formed in a flat plate shape.

  Further, the four mounting legs 12 mounted and erected at the four corners of the lower surface of the support base 6 are each formed by a metal post formed by forming a metal material such as copper into a quadrangular column shape, and externally. When the temperature compensated crystal oscillator is mounted on an external wiring board such as a mother board (not shown) such as a terminal, it is electrically connected to the circuit wiring of the external electric circuit by soldering or the like.

  These four mounting legs 12 are used as, for example, a ground terminal, a power supply voltage terminal, an oscillation output terminal, and an oscillation control terminal, and solder used for joining to an external wiring board is provided on the lower surface of these mounting legs 12. For example, nickel plating, gold plating, or the like is applied to a predetermined thickness in order to improve the bonding state such as.

  Here, of the four mounting legs 12, if the mounting legs 12 for ground terminals and the mounting legs 12 for oscillation output terminals are arranged close to each other, the signals are output from the oscillation output terminals. It is possible to effectively prevent noise from interfering with the oscillation signal. Therefore, it is preferable that the mounting leg 12 for the ground terminal and the mounting leg 12 for the oscillation output terminal are arranged close to each other.

  Further, the height t1 of these mounting legs 12 is formed to be higher by about 0.03 mm to 0.1 mm than the height t2 of the container body 1. As a result, when the temperature compensated crystal oscillator is mounted on the external wiring board by soldering or the like, it is possible to prevent the inconvenience that a part of the melted solder contacts the lid body 4 of the container body 1 and causes a short circuit. Can do.

  A writing control terminal 11 made of a metal post for writing temperature compensation data to an IC element 7 to be described later is attached and erected on the lower surface of the support base 6 together with the container body 1 and the mounting legs 12. The write control terminal 11 is formed into a quadrangular prism shape using the same metal material as that of the mounting leg 12 described above, and is electrically and mechanically connected to the wiring conductor of the support base 6 at the upper end thereof. It is electrically connected to the element 7 and is disposed along the edge of the outer peripheral portion of the lower surface of the support base 6 so that the side surface is exposed from the side face of the support base. Two write control terminals 11 are provided. After assembling the temperature compensated crystal oscillator, the two probe needles of the temperature compensated data writing device are connected to the exposed portions of the two write control terminals 11. The temperature compensation data is stored in the memory of the IC element 7 by writing the temperature compensation data corresponding to the temperature characteristics of the crystal resonator element 5.

  If the lower end of the write control terminal 11 is positioned above the lower end of the mounting leg 12, when the temperature-compensated crystal oscillator is mounted on the motherboard, the wiring of the motherboard and the write control terminal 11 There is a problem that a large stray capacitance is generated between them, or when a temperature compensated crystal oscillator is mounted on the mother board by soldering or the like, a part of the melted solder contacts the write control terminal 11 to cause a short circuit. This is advantageous in that the temperature compensated crystal oscillator can be handled easily and effectively. Specifically, the lower end of the write control terminal 11 is preferably positioned 0.01 mm or more above the lower end of the mounting leg.

  These mounting legs 12 and write control terminals 11 are made by sticking a metal foil such as a copper foil to the surface of the support base 6 and then adopting a well-known photo-etching or the like to make the metal foil into a predetermined pattern. It is formed by processing.

  Further, the container body 1 described above is covered with a resin material 13a made of an epoxy resin or the like, and the outer peripheral portion of the resin material 13a is extended to the outer peripheral portion of the support base 6, so that the adjacent mounting leg portions and the mounting legs If the gap between the part and the write control terminal is filled, the attachment strength to the support base 6 such as the container body 1 and the mounting leg 12 can be reinforced, and the mechanical strength of the temperature compensated crystal oscillator, In addition, it is possible to maintain high reliability. Further, by covering the entire container body 1 including the lid body 4 with the resin material 13a, when the temperature compensated crystal oscillator is mounted on the mother board by soldering or the like, a part of the melted solder is obtained. The inconvenience of causing a short circuit by contacting the lid body 4 of the container body 1 is effectively prevented.

  On the other hand, a plurality of IC element mounting electrode pads are deposited and formed on the upper surface of the support base 6, and the IC elements 7 are mounted in the electrode pad formation regions.

  As the IC element 7, for example, a rectangular flip chip type IC element having a plurality of connection pads corresponding to the electrode pads of the support base 6 on the lower surface is used. The IC element 7 includes a temperature sensing element (thermistor) for detecting the ambient temperature state, a memory for storing temperature compensation data for compensating the temperature characteristics of the crystal vibration element 5, and the crystal vibration element 5 based on the temperature compensation data. Is incorporated with a temperature compensation circuit that corrects the vibration characteristics according to a temperature change, an oscillation circuit that is connected to the temperature compensation circuit and generates a predetermined oscillation output, and the oscillation output generated by the oscillation circuit is externally After being output, for example, it is used as a reference signal such as a clock signal.

  In the IC element 7, the connection pad provided on one main surface thereof is individually bonded to the corresponding electrode pad for mounting the IC element on the upper surface of the support base via a conductive bonding material such as solder or gold bump. As a result, the IC element 7 is attached to the support base 6, whereby the electronic circuit in the IC element is attached to the crystal vibrating element 5, the mounting leg 12, etc. via the wiring conductor of the container body 1, the wiring conductor of the support base 6, etc. Electrically connected.

  In this way, the IC element 7 is mounted on the upper surface of the support base 6, that is, the main surface opposite to the mounting surface of the temperature compensated crystal oscillator on the external wiring board. The temperature compensated crystal oscillator can be mounted on the external wiring board in a state sufficiently separated from the board, and stray capacitance is prevented from being generated between the wiring pattern of the external wiring board and the wiring pattern in the IC element. At the same time, it is possible to effectively prevent the noise generated from the external wiring board from affecting the IC element, and to stabilize the circuit characteristics of the temperature compensated crystal oscillator.

  A chip capacitor 14 is mounted on the upper surface of the support base 6 as an electronic component element together with the IC element 7. This chip capacitor 14 is used, for example, as an element for forming a low-pass filter circuit incorporated in the IC element 7, thereby removing noise from the signal input to the oscillation circuit of the IC element 7, and extremely reducing the noise. A small number of oscillation signals can be output. In addition, by attaching the container body 1 to the lower surface of the support base in this way, it is possible to effectively use the entire upper surface of the support base 6 for mounting electronic component elements such as the IC element 7 and the chip capacitor. There is also an advantage of being able to do it.

  If these IC elements 7 and chip capacitors 14 are covered with a resin material 13b made of an epoxy resin or the like, the adhesive strength of the IC elements 7 to the supporting base is increased, and the IC elements 7 are good with the resin material 13b. Can be protected. Therefore, the IC element 7 and other electronic component elements mounted on the support base 6 are preferably covered with the resin material 13b. The resin material 13b may be the same resin material as the resin material 13a used for covering the container body 1, or may be another type of resin material.

  Thus, the above-described temperature compensated crystal oscillator is mounted on an external wiring board such as a mother board by soldering or the like, and the oscillation output is corrected by the temperature compensation circuit of the IC element 7, and according to the resonance frequency of the crystal resonator element 5. By outputting a predetermined oscillation signal, it functions as a temperature compensated crystal oscillator.

  According to the temperature compensated crystal oscillator of the present embodiment as described above, the write control terminal 11 for writing the temperature compensation data to the IC element 7 is formed by the metal post, and one of the write control terminals 11 is formed. Since the portion is exposed between the side surface of the container body and the side surface of the support base, when assembling the temperature compensated crystal oscillator, the write control terminal 11 made of a metal post is attached to a predetermined position on the top surface of the support base. The temperature compensated crystal oscillator can be manufactured by simply setting it, and there is no complicated processing process for forming a film-like write control terminal on the outer surface of the support substrate in the conventional temperature compensated crystal oscillator. Since it becomes unnecessary, the productivity of the temperature compensated crystal oscillator can be improved.

  In addition, this invention is not limited to the above-mentioned embodiment, A various change, improvement, etc. are possible in the range which does not deviate from the summary of this invention.

  For example, in the embodiment described above, the mounting leg 12 is formed by a metal post. Instead, the mounting leg 12 may be formed by using the same insulating material as the support base 6. good. In this case, the upper surface of the mounting leg 12 is provided with an upper surface bonding pad for electrically and mechanically connecting the mounting leg 12 to the electrode pad on the lower surface of the support base via a conductive bonding material. The lower surface of the leg 12 is provided with a lower surface bonding pad connected to the pad of the external wiring board via solder or the like, and the upper surface bonding pad and the lower surface bonding pad are formed by via-hole conductors formed inside the mounting leg. Connected.

  In the above-described embodiment, the container body 1 is attached to the lower surface of the support base 6 so that one side of the outer periphery of the container body 1 and one side of the outer periphery of the support base 6 are parallel. Alternatively, the container body 1 may be attached to the lower surface of the support substrate by inclining one side of the outer periphery of the container body 1 with a certain angle with respect to one side of the outer periphery of the support substrate 6. . This angle can be arbitrarily set in the range of 0 degrees to 90 degrees. Particularly, when the planar shape of the container body 1 is substantially square, as shown in FIG. 5, the container body 1 is supported by tilting one side of the outer periphery of the container body 1 with respect to one side of the outer periphery of the support base 6. As compared with the case where the container body 1 is attached so that one side of the container body 1 and one side of the support base 6 are substantially parallel to each other, the mounting leg 12 is attached to the lower surface of the mounting body 6. The area can be widened. As a result, the planar shape of the mounting leg portion 12 can be increased, and the bonding strength of the temperature compensated crystal oscillator to the external wiring board can be improved.

  Further, in the above-described embodiment, the mounting leg 12 and the write control terminal 11 are formed by a rectangular metal post, but the shape of the mounting leg 12 and the write control terminal 11 is not limited to this, Various shapes are possible according to the size and arrangement of the container body 1. For example, as shown in FIG. 5, the write control terminal 11 may be formed in a triangular prism shape, or as shown in FIG. As described above, the mounting legs 12 may be formed in a bowl-shaped column shape.

  In the embodiment described above, two write control terminals are provided. However, the number of write control terminals is not limited to two, and three or more write control terminals may be provided as necessary. .

  Furthermore, in the embodiment described above, the lid 4 of the container body 1 is bonded to the substrate 2 via the seal ring 3. Instead, a metallized pattern for bonding is formed on the upper surface of the substrate 2. In addition, the lid 4 may be directly welded to the metallized pattern.

  Furthermore, in the above-described embodiment, the seal ring 3 is directly attached to the upper surface of the substrate of the container body 1, but instead of this, the upper surface of the substrate 2 is made of the same ceramic material as the substrate 2. The frame body may be attached integrally, and the seal ring 3 may be attached to the upper surface of the frame body.

(A) is a perspective view of a temperature compensated crystal oscillator according to an embodiment of the present invention, and (b) is a perspective view in which a resin material is omitted from the temperature compensated crystal oscillator of (a). It is sectional drawing of the temperature compensation type | mold crystal oscillator of FIG. It is a perspective view of the container body attached to the temperature compensation type | mold crystal oscillator of FIG. It is the bottom view which abbreviate | omitted the resin material of the temperature compensation type | mold crystal oscillator of FIG. It is a bottom view of the temperature compensation type crystal oscillator concerning other embodiments of the present invention. It is a bottom view of the temperature compensation type crystal oscillator concerning other embodiments of the present invention. It is a perspective view of the conventional temperature compensation type | mold crystal oscillator.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Container body 2 ... Board | substrate 3 ... Seal ring 4 ... Lid body 5 ... Quartz vibration element 6 ... Support base | substrate 7 ... IC element 11 ... Write control terminal 12 ... Mounting leg 13 ... Resin material 14 ... Chip capacitor (electronic component element)

Claims (4)

A rectangular container housing the crystal resonator element and a plurality of mounting legs are fixed to the lower surface of the support substrate, and an oscillation signal corresponding to the oscillation frequency of the crystal resonator element is applied to the upper surface of the support substrate. A temperature compensated crystal oscillator equipped with an IC element that outputs while correcting based on temperature compensation data,
A write control terminal made of a metal post for writing temperature compensation data to the IC element is exposed in an outer peripheral area of the lower surface of the support base in an area where the mounting leg does not exist. A temperature compensated crystal oscillator characterized by being attached in a separated state. 2. The temperature-compensated crystal oscillator according to claim 1, wherein the mounting leg is composed of four metal posts attached to four corners on the lower surface of the support base. The periphery of the container body is covered with a resin material, and the outer peripheral portion of the resin material is extended to the outer peripheral portion of the support base. The extended portions are connected between adjacent mounting legs, and the mounting legs 3. The temperature compensated crystal oscillator according to claim 1, wherein a gap between the control terminals is filled. 4. The temperature compensated crystal oscillator according to claim 1, wherein a lower end of the write control terminal is positioned above a lower end of the mounting leg.

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