JP4376153B2 - Method for manufacturing piezoelectric oscillator - Google Patents

Description

          The present invention relates to a method of manufacturing a piezoelectric oscillator mainly used as a timing device for communication equipment, electronic equipment, and the like.

Conventionally, crystal oscillators have been used as timing devices for communication equipment such as mobile phones.
As such a conventional crystal oscillator, for example, a crystal oscillator shown in FIG. 3 will be described. A container body 23 in which a crystal resonator element 24 is accommodated is provided, and a plurality of recesses 25 are provided on the lower surface in the central region of the upper surface. And an oscillation signal is output based on the oscillation frequency of the crystal resonator element 24 in a region surrounded by the lower surface of the container body 21 and the inner surface of the recess 25. A structure having an integrated circuit element 26 to be accommodated is generally known. (For example, refer to Patent Document 1).

          The container body 23 and the mounting base 21 are usually made of a ceramic material such as alumina ceramics, and a wiring pattern is formed on the inside and the surface thereof, and a conventionally known green sheet laminating method or the like is adopted. It has been produced. A plurality of bonding electrodes are provided at corresponding positions on the lower surface of the container body 23 and the upper surface of the mounting base 21, and these bonding electrodes are bonded to each other with a conductive bonding material. As a result, the container body 23 was fixed to the upper surface of the mounting base 21.

          Further, a temperature compensation circuit for correcting the oscillation output of the crystal oscillator based on the temperature compensation data created according to the temperature characteristics of the crystal resonator element 24 is provided inside the integrated circuit element 26. In order to store such temperature compensation data in the memory in the integrated circuit element 26, a characteristic control data writing terminal 27 is provided on the outer surface of the mounting substrate 21. After assembling the crystal oscillator, the temperature compensation data is input to the integrated circuit element 26 by applying the probe needle of the temperature compensation data writing device to the characteristic control data writing terminal 27 and inputting the temperature compensation data to the integrated circuit element 26. Stored in the memory.

JP 2000-77943 A

          However, in the above-described conventional piezoelectric oscillator, the characteristic control data write terminal ensures the contact with the probe. In practice, the characteristic control data write terminal occupies a minimum area. It becomes necessary. Therefore, if the piezoelectric oscillator is downsized while maintaining the area of the characteristic control data writing terminal, there is a problem that a short circuit may occur with the external terminal.

          In the conventional piezoelectric oscillator described above, a characteristic control data write terminal 27 for writing temperature compensation data on the outer surface of the mounting substrate 21 or a monitor terminal for measuring the characteristics of the crystal resonator element is provided. However, if the piezoelectric oscillator is simply miniaturized as described above, the electrode terminal plating is peeled off by the individual blades (blades) when the piezoelectric oscillator is divided into individual piezoelectric oscillators from the mother board, and energized. There was a problem that it might become defective.

          The present invention has been conceived in view of the above problems, and therefore an object of the present invention is to provide a method of manufacturing a piezoelectric oscillator that is easy to handle and excellent in productivity.

          In the piezoelectric oscillator manufacturing method of the present invention, the substrate region having the first characteristic control data write terminal on the inner wall of the cavity portion on the lower surface and the discarding region having the second characteristic control data write terminal are adjacent to each other. Step A for preparing a mother substrate formed by arranging a plurality of substrates, a quartz resonator element is accommodated in the upper cavity portion, and an oscillation signal corresponding to the oscillation frequency of the quartz resonator element is temperature compensated in the lower cavity portion. Integrated circuit element in each substrate region via an integrated circuit element that outputs while correcting on the basis of data, and a second characteristic control data writing terminal formed in the abandoned region Temperature compensation data is input to the memory in the integrated circuit element C, and the mother substrate is cut along the outer periphery of each substrate region. A step D of simultaneously obtaining a plurality of piezoelectric oscillators in which a mounting base corresponding to the substrate region and an integrated circuit element are attached to the container body, and an inner wall of the cavity portion of the substrate region; And the step E of inputting temperature compensation data to the integrated circuit element again via the first characteristic control data write terminal formed in the step of storing the temperature compensation data in the memory in the integrated circuit element. Features.

          According to the present invention, by providing the characteristic control data writing terminal and the crystal vibration element monitor terminal on the inner wall portion of the cavity portion, the space of the inner wall portion can be used remarkably effectively and the piezoelectric oscillator can be downsized. There is an effect that makes it possible.

          Further, according to the present invention, the characteristic control data writing terminal and the monitor terminal of the crystal resonator element are formed to a height up to the height portion where the integrated circuit element is mounted, so that the probe can be easily applied, As a result, the productivity of the piezoelectric oscillator can be remarkably improved.

          Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. In each figure, the same numerals indicate the same objects.

          FIG. 1 is an exploded perspective view of a piezoelectric oscillator according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view of the piezoelectric oscillator. The piezoelectric oscillator shown in these figures has a crystal in a cavity on the upper surface side of a container body. The vibration element 5 is accommodated, and the integrated circuit element 7 is attached to the lower surface side of the container body cavity.

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

         The container body 1 accommodates the quartz crystal resonator element 5 in the 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, and is hermetically sealed. For this purpose, a pair of mounting pads connected to the vibration electrodes of the crystal resonator element 5 are provided on the upper surface of the substrate 2.

          When the substrate 2 is made of alumina ceramics, the substrate 2 of the container body 1 has a wiring pattern on the surface of a ceramic green sheet obtained by adding an appropriate organic solvent to a predetermined ceramic material powder and mixing it. The conductor paste is applied by well-known screen printing or the like, and a plurality of the pastes are laminated and press-molded, and then fired at a high temperature.

          Further, the seal ring 3 and the lid 4 of the container body 1 are manufactured by adopting a conventionally known metal processing method and molding a metal such as 42 alloy into a predetermined shape, and the resulting seal The ring 3 is brazed to a conductor layer previously deposited on the upper surface of the substrate 2, and then the quartz resonator element 5 is mounted and fixed on the upper surface of the substrate 2 using a conductive adhesive, and then the seal ring The container body 1 is assembled by joining the lid body 4 to the upper surface of 3 by conventional well-known 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 a pair of vibrating electrodes to both main surfaces of a crystal piece cut along a predetermined crystal axis, and varies from the outside. When a voltage is applied to the crystal piece via a pair of vibrating electrodes, thickness shear vibration is caused at a predetermined oscillation 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. The electrical connection between the container body 1 and the mechanical connection are made simultaneously.

           Here, if the lid body 4 of the container body 1 is connected to the ground external terminal 12 on the lower surface of the previous container body via the wiring pattern of the container body 1, the lid body 4 is grounded and shielded during use. Since the function is added, as a result, it is possible to better protect the crystal resonator element 5 and the integrated circuit element 7 to be described later than unnecessary electric action from the outside.

          The four external terminals described above function as a power supply voltage terminal, a ground terminal, an oscillation output terminal, and an oscillation control terminal.

          Here, of the four external terminals, if the ground external terminal 12 and the oscillation output external terminal 12 are arranged close to each other, noise interferes with the oscillation signal output from the oscillation output terminal. This can be effectively prevented. Therefore, it is preferable that the ground external terminal 12 and the oscillation output external terminal 12 be arranged close to each other.

          On the other hand, as the integrated circuit element 7 attached to the cavity on the lower surface side of the container body 1, for example, a rectangular flip chip IC having a plurality of connection pads on the lower surface is used, and the circuit on the lower surface thereof is used. The forming surface has a temperature sensing element such as a thermistor for detecting the surrounding 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. A temperature compensation circuit that corrects vibration characteristics according to a temperature change, an oscillation circuit that is connected to the temperature compensation circuit and outputs a predetermined oscillation output, and the like are provided. The oscillation output output from the previous oscillation circuit is, for example, It is used as a reference signal such as a clock signal.

         In the cavity on the lower surface side of the container body 1 in which such an integrated circuit element 7 is disposed, electrode pads corresponding to the connection pads of the integrated circuit element 7 are provided respectively, and these electrode pads are provided. By connecting the connection pads of the integrated circuit element 7 to each other through a conductive bonding material such as solder or gold bump, the integrated circuit element 7 is mounted and mounted in the cavity on the lower surface side of the container body 1. The electronic circuit in the circuit element 7 is electrically connected to the crystal vibration element 5 and the external terminal 12 through the wiring pattern of the container body 1 and the like.

          A plurality of characteristic control data write terminals 11 for writing temperature compensation data to the integrated circuit element 7 are provided on the inner wall in the cavity portion on the lower surface side of the container body 1 described above.

          The memory of the integrated circuit element 7 is written by applying the probe needle 20 of the temperature compensation data writing device to the characteristic control data writing terminal 11 from the horizontal direction and writing the temperature compensation data corresponding to the temperature characteristic of the crystal resonator element 5. The temperature compensation data is stored in the inside.

At this time, for example, a probe having a structure in which the probe needle 20 protrudes in the horizontal direction for the first time when contacting the integrated circuit element 7 is used as the probe 16 of the temperature compensation data writing device.

          Thus, the above-described piezoelectric oscillator is mounted on an external wiring board such as a mother board by soldering or the like, and while correcting the oscillation frequency according to the temperature state using the temperature compensation circuit of the integrated circuit element 7, the crystal resonator element 5. The piezoelectric oscillator functions by outputting a predetermined oscillation signal corresponding to the oscillation frequency.

Next, a method for manufacturing the above-described piezoelectric oscillator will be described.
(Step A) First, a substrate region A having a first characteristic control data write terminal 11 on the inner wall of the cavity portion on the lower surface and a throw-away region B having a plurality of second characteristic control data write terminals 12 are formed. A mother substrate 15 in which these are arranged adjacent to each other and arranged in a matrix is prepared. Such a mother substrate 15 is formed of a low-temperature fired substrate material such as glass-ceramic, a ceramic material such as alumina ceramic, and the thickness is set to 20 μm to 300 μm, for example, and the material is, for example, 800 ° C. A glass-ceramic material that can be fired at a relatively low temperature of ˜1200 ° C. is appropriately used.

Specific examples of the ceramic material constituting the glass-ceramic material include cristobalite, quartz, corundum (α-alumina), mullite, cordierite and other insulating ceramic materials, BaTiO ₃ , Pb ₄ Fe ₂ Nb ₂ O ₁₂ , TiO ₂ or the like, or a magnetic ceramic material such as Ni-Zn ferrite or Mn-Zn ferrite (referred to as ceramic in a broad sense) is used. The average particle diameter is 1.0 to 6.0 μm, preferably 1.5 to 4.0 μm. Moreover, you may use a ceramic material in mixture of 2 or more types of the above-mentioned. In particular, when corundum (α-alumina) is used, there is an advantageous effect in terms of cost.

Also, as a material of the glass material, crystals of cordierite, mullite, anorthite, serdian, spinel, garnite, willemite, dolomite, petalite, or substituted derivatives thereof, and crystal phases of the spinel structure are precipitated by firing. For example, B ₂ O ₃ , SiO ₂ , Al ₂ O ₃ , ZnO, glass frit containing an alkaline earth oxide, or the like is appropriately used. Such a glass frit has a wide vitrification range, and its yield point is around 600 to 800 ° C.

          Although not shown in the drawing, the substrate 10 has a conductor pattern serving as a circuit pattern or a component mounting pad inside and on the main surface. Here, the material of the conductor pattern is selected in consideration of compatibility with the dielectric material forming the dielectric layer. For example, a conductive material mainly composed of an Ag alloy such as Ag, Ag—Pd, or Ag—Pt, It is formed of a Cu-based, W-based, Mo-based, Pd-based conductive material or the like, and its thickness is set to 5 to 25 μm, for example.

          In addition, the circuit pattern, the first characteristic control data write terminal 11, the second characteristic control data write terminal 12, the second junction electrode, the external terminal, etc. A conductor pattern. The conductive pattern is selected in consideration of the compatibility with the dielectric material forming the dielectric layer, such as a conductive material mainly composed of an Ag alloy such as Ag, Ag-Pd, or Ag-Pt. It is formed of a Cu-based, W-based, Mo-based, Pd-based conductive material or the like, and its thickness is set to 5 to 25 μm, for example.

         (Process B) The quartz resonator element 5 is accommodated in the cavity portion on the upper surface, and the oscillation signal corresponding to the oscillation frequency of the quartz resonator element is output to the cavity portion on the lower surface while correcting based on the temperature compensation data. Install the circuit elements.

          As the integrated circuit element 7, for example, a rectangular flip chip type IC having a plurality of connection pads corresponding to the electrode pads on the lower surface cavity portion of the container body on a lower surface is used. On the lower circuit forming surface, a temperature sensing element such as a 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 a crystal vibration element based on the temperature compensation data 5 is provided 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 outputs a predetermined oscillation output, and the oscillation output of the oscillation circuit is After being output to the outside, for example, it is used as a reference signal such as a clock signal.

          The integrated circuit element 7 is formed by individually bonding the connection pads provided in the cavity portion to the corresponding electrode pads on the upper surface via a conductive bonding material such as solder or gold bump. 7 is mounted in the cavity portion on the lower surface, whereby the electronic circuit in the integrated circuit element 7 is electrically connected to the crystal vibrating element 5, the external terminal 10, etc. via the wiring conductor of the container body 1. Become.

          Further, in the process B, the first characteristic control data write terminal 11 on the inner wall of the cavity portion on the lower surface of the substrate region A, and the second characteristic control data write terminal 12 and the integrated circuit element 7 in the area B to be discarded. Are electrically connected via the wiring conductor of the container body 1 and the mother board 15.

(Step C) Next, temperature compensation data is input to the integrated circuit elements 7 in each substrate region A via a plurality of second characteristic control data write terminals 12 provided in the area B to be discarded of the mother substrate 15. The temperature compensation data is stored in the memory in the integrated circuit element 7.

          Such temperature compensation data writing operation was created according to the temperature characteristics of the crystal resonator element 5 by placing the probe needle 20 of the temperature compensation data writing device against the second characteristic control data writing terminal 12. This is done by inputting the temperature compensation data into a memory provided in the temperature compensation circuit of the integrated circuit element 7 and storing it. Here, the temperature compensation data written to the integrated circuit element 7 is for correcting the temperature characteristic variation for each crystal resonator element, and the temperature characteristics of the crystal resonator element 5 used in the piezoelectric oscillator are determined in advance. Obtained by measuring.

        (Step D) Next, the mother board 15 is cut along the outer periphery of each board area A, so that each board area A is discarded from the area B.

          The mother substrate 15 is cut by conventionally known dicing (divided), and the mother substrate 15 is divided into individual substrate regions through the cutting process. Thus, a plurality of piezoelectric oscillators in which the integrated circuit element 7 is attached to the lower surface of the container body 1 can be obtained simultaneously.

        (Step E) Finally, the temperature compensation data is input again to the integrated circuit element 7 through the first characteristic control data writing terminal 11 formed on the inner wall of the cavity portion on the lower surface of the container body 1, and the integrated circuit By storing the temperature compensation data in the memory in the element 7, it is possible to readjust the temperature compensation data on the mother board that has been input incorrectly even if it is in the individual state after division. As a result, the production yield of the piezoelectric oscillator can be remarkably improved.

          For example, when the probe 16 of the temperature compensation data writing device comes into contact with the integrated circuit element, the probe needle 20 pops out for the first time, and the tip of the probe needle 20 is applied to the first characteristic control data writing terminal. A probe 16 having a structure capable of inputting temperature compensation data to the integrated circuit element is used.

          It should be noted that the present invention is not limited to the above-described embodiment, and various modifications and improvements can be made without departing from the gist of the present invention. Therefore, in these cases, the technical scope of the present invention is also included. Needless to say, it is included.

          In the embodiment described above, a general conductive bonding material such as solder is used to attach the integrated circuit element 7 to the cavity on the lower surface side of the container body 1. However, the present invention is not limited to this. For example, an anisotropic conductive adhesive or the like may be used as the conductive bonding material, and it goes without saying that this case is also included in the technical scope of the present invention. When an anisotropic conductive adhesive or the like is used as the conductive bonding material, the work of attaching the integrated circuit element 7 or the like to the container body 1 becomes extremely simple, and the assembly process of the piezoelectric oscillator is further simplified. is there.

          Further, in the above-described embodiment, 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. Therefore, the lid 4 may be directly welded to the metallized pattern, and it goes without saying that this case is also included in the technical scope of the present invention.

          Furthermore, for example, in the above-described embodiment, the lid 4 is attached to the container body 1 using the seal ring 3, but instead of this, a bonding conductor such as Au—Sn on the upper surface of the container body is used. On the other hand, the lid 4 may be attached to the container 1 by directly joining the lid 4, and it goes without saying that this case is also included in the technical scope of the present invention.

          Furthermore, in the embodiment described above, the seal ring 3 is directly attached to the upper surface of the substrate of the container body 1. Instead of this, a frame made of a ceramic material or the like made of the same material as the substrate 2 is provided on the upper surface of the substrate 2. The body may be integrally attached, and the seal ring 3 may be attached to the upper surface of the previous frame, and it goes without saying that this case is also included in the technical scope of the present invention.

          Furthermore, in the embodiment described above, it goes without saying that, for example, a chip-like capacitor for noise removal may be disposed between the adjacent mounting legs, etc., in the empty space on the lower surface of the container body. Needless to say, such a case is included in the technical scope of the present invention.

          Furthermore, in the above-described embodiment, the crystal vibration element is used, but it goes without saying that a piezoelectric vibration element such as a SAW device may be used.

FIG. 3 is a schematic exploded perspective view showing one piezoelectric oscillator according to an embodiment of the present invention divided into an upper cavity and a lower cavity. 1 is a schematic side cross-sectional view of one piezoelectric oscillator according to an embodiment of the present invention. FIG. 2 is a schematic external perspective view showing a manufacturing pattern of the piezoelectric oscillator shown in FIG. 1 and viewing a plurality of piezoelectric oscillators formed on a mother substrate from the lower cavity side. FIG. 6 is a schematic exploded perspective view showing a conventional piezoelectric oscillator divided into an upper cavity and a lower cavity.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Container body 2 ... Board | substrate 3 ... Seal ring 4 ... Lid body 5 ... Quartz vibration element 7 ... Integrated circuit element 10 ... External terminal 11 ... Characteristic control data writing Terminal 12 ··· Monitor terminal 15 ··· Mother board 16 · · Probe 20 · · Probe needle

Claims (3)

A mother board formed by arranging a plurality of substrate regions each having a first characteristic control data writing terminal on the inner wall of the cavity portion on the lower surface and a discarding region having a second characteristic control data writing terminal adjacent to each other. Step A for preparing a substrate;
A step B in which a crystal resonator element is accommodated in the upper cavity portion, and an integrated circuit element that outputs an oscillation signal corresponding to the oscillation frequency of the crystal resonator element based on temperature compensation data is attached to the lower cavity portion;
The temperature compensation data is input to the integrated circuit element in each substrate area via the second characteristic control data writing terminal formed in the discarding area, and the temperature compensation data is stored in the memory in the integrated circuit element. Step C to be performed
By cutting the mother board along the outer periphery of each board area, each board area is discarded and separated from the area, and a mounting substrate corresponding to the board area and an integrated circuit element are attached to the container body. Step D for simultaneously obtaining a plurality of piezoelectric oscillators;
The temperature compensation data is input again to the integrated circuit element via the first characteristic control data write terminal formed on the inner wall of the cavity portion of the substrate region, and the temperature compensation data is stored in the memory in the integrated circuit element. Step E
A method for manufacturing a piezoelectric oscillator comprising:           In the step A, a mother board formed by arranging a plurality of substrate regions each having a first characteristic measurement terminal on the inner wall of the cavity portion on the lower surface and a discarding region having a second characteristic measurement terminal adjacent to each other. 2. The method of manufacturing a piezoelectric oscillator according to claim 1, wherein the piezoelectric oscillator is in a state.           In step D, temperature compensation data writing used when temperature compensation data is input again to the integrated circuit element via the first characteristic control data writing terminal formed on the inner wall of the cavity portion of the substrate region. 2. The method of manufacturing a piezoelectric oscillator according to claim 1, wherein the probe needle of the probe protrudes in the horizontal direction only after the probe of the apparatus comes into contact with the integrated circuit element.

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