JP4920526B2 - Pallet and method for manufacturing piezoelectric vibrator - Google Patents

Description

  The present invention relates to a pallet, a piezoelectric vibrator and a manufacturing method thereof, an oscillator, an electronic device, and a radio timepiece.

  Piezoelectric vibrators are widely used as clock functions and frequency control mechanisms in oscillators, electronic devices such as information communication devices and portable devices, and home appliances. As a package of the piezoelectric vibrator, a box-shaped ceramic package and a cylinder-type package using an airtight terminal are commonly used.

  FIGS. 13A and 13B are schematic views showing an airtight terminal and a cylindrical case (package). The hermetic terminal 1 is made of a metal, and a ring-shaped ring 7 is filled with a filler 5 for sealing, and two leads 2 made of metal thin rods are fixed to the filler 5 in parallel. One end of each lead 2 is an inner lead 3 with the ring 2 interposed therebetween, and the other end is an outer lead 4 electrically connected to the outside. Further, the surfaces of the lead 2 and the ring 7 are plated, and a piezoelectric vibrator piece (not shown) is connected to the surface of the inner lead 3. The case 20 is inserted along the outer shape of the ring 7. Further, the space between the ring 7 and the case 20 is cold through a plating layer 6 made of a soft metal on the outer surface of the ring 7 (the thickness is exaggerated in FIG. 13B). It is designed to be airtightly joined by pressure welding.

As a method for manufacturing such a piezoelectric vibrator, there is conventionally known a technique in which a plurality of hermetic terminals are held on a pallet and the piezoelectric vibrator assembly process is flowed in that state. As a pallet used in such a method, there is known a pallet composed of a plate body made of an insulating resin in which a large number of through windows are aligned and a fixed spring formed of a conductive leaf spring. (See Patent Document 1).
Japanese Patent Publication No.57-50795

  By the way, in the assembly (manufacturing) process of the piezoelectric vibrator, in order to finely adjust the frequency of the piezoelectric vibrator piece joined to the hermetic terminal, the probe is applied to the outer lead of the hermetic terminal while vibrating the piezoelectric vibrator piece. There is a fine adjustment process for measuring the transmission frequency. Further, prior to the step of finely adjusting the frequency of the piezoelectric vibrator piece, there is also a baking process for performing baking for the purpose of eliminating distortion when the piezoelectric vibrator piece is mounted.

However, in the baking process, if the pallet shown in Patent Document 1 is made of a resin, a part of the solvent remaining in the pallet or a decomposition product of the resin is caused by high-temperature vacuum processing for baking. Such gas is generated as gas, and when this outgas finely adjusts the frequency, the product characteristics are affected and the product characteristics may be impaired. In addition, when used repeatedly, deformation may occur due to high-temperature treatment, and it may become unable to withstand subsequent use, resulting in high costs.
In order to eliminate the generation of gas, a metal pallet may be used. In this case, when finely adjusting the frequency, the two outer leads are electrically connected via the pallet. Therefore, fine adjustment cannot be performed with the airtight terminal held on the pallet.

The present invention has been made in view of the above circumstances, and provides a pallet that prevents the occurrence of outgas during high-temperature processing and suppresses adverse effects due to outgas, and enables fine adjustment of the frequency of the piezoelectric vibrator piece. Furthermore, it is an object to provide a manufacturing how the piezoelectric vibrator using the palette.

In order to achieve the above object, the pallet of the present invention includes an annular ring and an inner lead that is disposed in a state of penetrating the ring, and one end side of which is electrically connected to the piezoelectric vibrator piece with the ring interposed therebetween. The other end is electrically connected to the outside, and two leads, which are outer leads, and a holding portion for holding an airtight terminal for joining the piezoelectric vibrator piece to the inner lead. A pallet made of
It is characterized by comprising a plate-like base material made of metal, and an insulating material coated by a liquid phase method on at least the surface of the base material on which the holding portion is formed.

According to this pallet, since the base material is made of metal, generation of outgas during high temperature treatment is prevented, and adverse effects due to outgas are suppressed. In addition, since it is made of metal, it has high durability and heat resistance. Therefore, it is hardly deformed even by repeated use, and therefore, it can be used repeatedly, so that the cost can be reduced.
In addition, since at least the surface of the base material on which the holding portion is formed is coated with an insulating material, conduction between the outer leads can be reliably prevented in the step of finely adjusting the frequency of the piezoelectric vibrator piece. Furthermore, since the insulating material is coated by the liquid phase method, the coating unevenness such as the coating thickness being reduced at the corners and concave portions as in the case of coating by the gas phase method is small. Conduction between them is reliably prevented.

In the pallet, an insulating resin is preferably used as the insulating material, and in that case, polyimide is preferably used as the insulating resin.
Insulating resin as a coating material is often excellent in heat resistance, such as polyimide, and therefore there is almost no generation of gas due to decomposition, so there is almost no outgassing during high-temperature processing, and thus adversely affected. There is no risk of effects.
In particular, polyimide has high heat resistance, strong film adhesion, and excellent wear resistance, chemical resistance, etc., so that the coating film hardly deteriorates even if the pallet is repeated frequently. Therefore, the cost can be reduced by increasing the repetition frequency of the pallet.

Further, in the pallet, the holding portion includes a pair of guide grooves each holding two outer leads of the hermetic terminal, and one end portion of each guide groove is connected to an end surface side of the pallet. It is preferable that the opening is formed.
In this way, since one end portion of the guide groove is open to the end face side of the pallet, the two outer leads of the airtight terminal are respectively inserted into the guide groove with the ring positioned outside the end face. Can be held easily. Therefore, for example, even if the hermetic terminal is downsized corresponding to the downsizing of the piezoelectric vibrator, it can be easily held.

Further, in the pallet, a groove-like recess that communicates with the other end portion of the guide groove and positions the end portion of the outer lead held in the guide groove is provided in the length direction of the end surface of the pallet. It is preferable to form along.
In this way, by positioning the end portion of the outer lead held in the guide groove in the recess, the processing in the step of finely adjusting the frequency of the piezoelectric vibrator piece joined to the airtight terminal is facilitated. That is, in the step of finely adjusting the frequency of the piezoelectric vibrator piece, as described above, the probe is applied to the outer lead for fine adjustment. However, in the pallet of the present invention, the end of the outer lead is positioned in the groove-shaped recess. Therefore, the end portion of the outer lead is in a state where its side is opened in the recess. Therefore, since the upper side and the side of the end of the outer lead are opened in the recess, the area where the probe can come into contact with the outer lead becomes large, and the probe can be accurately applied to the outer lead. It becomes easy.

In the pallet, the interval between the two guide grooves forming the guide pair is such that the interval W1 at the end edge on the end surface side of the pallet is the interval W on the ring side of the two outer leads. It is preferable that the interval W2 on the concave side is narrower and wider than the interval W.
Since the interval W1 between the two guide grooves at the edge portion on the end surface side of the pallet is narrower than the interval W between the two outer leads, the two outer leads of the airtight terminal are moved from the ring side to the guide groove. The two outer leads can be easily held in the guide groove without being interfered by the bank portion between the guide grooves by being fitted and held in the guide grooves. In addition, since the interval W2 between the two guide grooves on the concave side is wider than the interval W, simply holding the two outer leads in the guide groove, the end portion (tip portion) Can be naturally expanded in the recess. Therefore, for example, even if the distance between the outer leads is narrowed due to the miniaturization of the piezoelectric vibrator, in the step of finely adjusting the frequency by naturally widening the distance between the end portions, It is possible to suppress the outer leads from interfering with each other. Therefore, it is easy to accurately apply the probe to the outer lead.

Further, the piezoelectric vibrator manufacturing method of the present invention includes an annular ring, an inner lead that is disposed in a state of penetrating the ring, and one end side of which is electrically connected to the piezoelectric vibrator piece with the ring interposed therebetween. A piezoelectric vibrator piece is joined to the inner lead of the hermetic terminal having two outer leads whose outer ends are electrically connected to the outside, and then the piezoelectric vibrator Finely adjusting the frequency of the piece, and then press-fitting the case into the ring of the airtight terminal covering the piezoelectric vibrator piece,
The two outer leads of the hermetic terminal are held by the holding portion of the pallet, and the hermetic terminal is allowed to flow into the piezoelectric vibrator assembling process in that state.
According to this method of manufacturing a piezoelectric vibrator, as a pallet for holding an airtight terminal, adverse effects due to outgassing are suppressed, almost no deformation is caused by repeated use, and the frequency of the piezoelectric vibrator piece is finely adjusted. In this process, since the one that can reliably prevent conduction between the outer leads is used, the hermetic terminal can be easily flowed into the piezoelectric vibrator assembly process, and the process in the process of finely adjusting the frequency Can be made easier.

The piezoelectric vibrator of the present invention is obtained by the above manufacturing method.
According to this piezoelectric vibrator, the airtight terminal easily flows through the piezoelectric vibrator assembling process, and the process in the process of finely adjusting the frequency is also easily performed, so that the productivity is good. Therefore, the production cost is reduced.

The oscillator according to the present invention is characterized in that the piezoelectric vibrator is connected to an integrated circuit as an oscillator.
In addition, an electronic apparatus according to the present invention includes the above-described piezoelectric vibrator.
The radio timepiece of the present invention is characterized in that the piezoelectric vibrator is electrically connected to a filter portion.

  According to the oscillator, the electronic device, and the radio-controlled timepiece according to the present invention, the oscillator, the electronic device, and the radio-controlled timepiece itself are provided with a piezoelectric vibrator that has good productivity and reduced production costs. Productivity is good, and production costs are reduced.

According to the pallet of the present invention, adverse effects due to outgassing are suppressed, deformation hardly occurs even after repeated use, and conduction between outer leads is ensured in a process of finely adjusting the frequency of the piezoelectric vibrator piece. Can be prevented. Therefore, the cost can be reduced by enabling repeated use.
According to the method for manufacturing a piezoelectric vibrator of the present invention, by using the pallet, the hermetic terminal can be easily flowed into the piezoelectric vibrator assembly step, and the frequency of the piezoelectric vibrator piece is finely adjusted. It is also possible to facilitate the processing.
According to the piezoelectric vibrator of the present invention, by using the pallet, the productivity is good, and therefore the production cost is reduced.
According to the oscillator, the electronic apparatus, and the radio timepiece of the present invention, the oscillator, the electronic apparatus, and the radio timepiece itself are provided with the piezoelectric vibrator that has good productivity and reduced production costs. Also, the productivity is good and the production cost is reduced.

Hereinafter, the present invention will be described in detail [Palette].
FIGS. 1A and 1B are views showing an embodiment of a pallet according to the present invention, FIG. 1A is a plan view showing a schematic configuration of the pallet, and FIG. 1B is an enlarged view of a portion A in FIG. It is.
As shown in FIGS. 1A and 1B, the pallet 10 of the present embodiment is a long and thin rectangular plate, and has a thickness of about 0.3 mm to several mm. In the present embodiment, 0.4 mm. It is formed to the extent. Further, as will be described in detail later, the pallet 10 is formed by coating a metal base plate with an insulating material.

  The pallet 10 is for holding a plurality of hermetic terminals 1 as shown in FIG. 2, and as shown in FIGS. 1 (a) and 1 (b), a guide pair 12 comprising two guide grooves 12a and 12a. A plurality of (28 in the present embodiment), and a groove-like recess 14 communicating with the guide pair 12.

  The guide pair 12 functions as a holding portion in the present invention, and as shown in FIG. 1 (b), the two guide grooves 12a and 12a are arranged in a C shape instead of in parallel. One end of each guide groove 12 a is formed in an open state on the end surface 11 side which is one long side of the pallet 10. Note that the other end of the guide groove 12a communicates with the recess 14 as described above, and is thus opened in the recess 14. The groove width of the guide groove 12a is formed to be substantially the same as the outer diameter of the outer lead 4 of the hermetic terminal 1. Specifically, the width of the guide groove 12a is about 0.2 mm to 1.0 mm. In the embodiment, it is about 0.3 mm.

In the present embodiment, a recess 15 is also formed along the length direction on the end face 11 side, and one end of the guide grooves 12a and 12a (guide pair 12) is formed in the recess 15. By communicating and opening here, it is in the state opened to the end surface 11 side of the pallet 10 as mentioned above. The opening edges of the guide grooves 12a and 12a (guide pair 12) and the recess 15 are chamfered at the corners, and the guide grooves 12a and 12a (guide pair 12) are hermetically sealed as described later. When one outer lead 4 is fitted and held here, it can be smoothly fitted without being caught by the opening edge. Note that such chamfering of the corners is performed on all the corners of the base material.
Further, as shown in FIG. 2, the distance between the adjacent guide pair 12 and the guide pair 12 is the distance between the tips of the two outer leads 4, 4 of the airtight terminal 1, the adjacent airtight terminal 1, 1 is set and formed so that the distance between the tips of the adjacent outer leads 4, 4 in FIG.

  The concave portion 14 is formed along the length direction of the end face 11 of the pallet 10 and communicates with all the guide grooves 12a and 12a (guide pairs 12), thereby allowing the outer grooves held in the guide grooves 12a. The end (leading end) of the lead 4 is positioned in the recess 14. Here, the recess 14 is formed to the same depth as the guide grooves 12a and 12a. In this embodiment, the thickness of the pallet 10 is about 0.4 mm, whereas the thickness is about 0.2 mm. Yes. Further, the width of the recess 14 (width in the direction orthogonal to the end surface 11) is about 2.0 mm. By positioning the end portion (tip portion) of the outer lead 4 in the concave portion 14, the end portion of the outer lead 4 is opened laterally in the concave portion 14 as shown in FIG. 3. Therefore, the upper side and the side are opened in the recess 14.

  That is, for example, when only the guide groove 12a is not provided with the recess 14 or a recess is formed for each guide pair 12, the bank portion 13 of the pallet 10 is formed on the outer lead 4 as shown by a two-dot chain line in FIG. Close the sides. Then, as will be described later, when finely adjusting the frequency of the piezoelectric vibrator piece, the portion with which the probe abuts is limited only above the outer lead 4, and it is difficult to accurately abut here. End up. On the other hand, as shown by the solid line in FIG. 3, the recess 14 is formed in a groove shape along the length direction of the end surface 11 of the pallet 10, so that the end of the outer lead 4 has a bank portion on its side. 13 is opened (exposed) without being closed, and therefore the contactable area of the probe is increased accordingly.

  Further, as shown in FIG. 1A, a plurality (four in this embodiment) of through holes 16, 17, 18, 19 are formed in the pallet 11 on the side opposite to the end face 11. . These through holes 16 to 19 are formed for positioning or conveying when the pallet 11 is flowed to the piezoelectric vibrator assembling process as will be described later.

  As described above, the pallet 11 having such a shape is formed by coating a metal base material with an insulating resin in the present embodiment. In this embodiment, the base material is made of a stainless steel plate having a thickness of about 0.3 mm, and the guide pair 12 (guide grooves 12a, 12a) and the concave portion 14 are formed on the stainless steel plate by etching or the like. Has been. Further, as described above, the corners are all chamfered. Specifically, the stainless steel plate is preferably made of SUS304 because it is excellent in corrosion resistance and low emission gas characteristics.

  In addition, a magnetic material such as SUS400 is particularly suitable when a plurality of pallets 10 are inspected side by side by using magnetism, or when it is desired to move during or between processes. Specifically, the pallet 10 can be simply fixed to a tray or the like on which magnets are arranged during monitoring and inspection of external appearance and electrical characteristics during the assembly process or manual correction work. Further, the pallet 10 can be prevented from dropping when the tray is moved to another work table.

The insulating resin used as the coating material is not particularly limited, and known ones such as polyimide (PI) and polyamideimide (PAI) can be used. Among these, polyimide is preferably used because it has high heat resistance and strong film adhesion, and is excellent in wear resistance and chemical resistance. Therefore, in this embodiment, polyimide is used as the coating material.
The coating material made of polyimide is prepared by appropriately selecting and blending various fillers (fillers) such as functional fillers that improve heat resistance and wear resistance into polyimide resin, and further dissolving or dispersing them in an appropriate solvent. Used.

That is, in order to form the pallet 10, first, a base material that has been previously processed for the guide pair 12, the concave portion 14, and the like is prepared and cleaned. For washing, general water washing is sufficient, but solvent washing and acid washing for the purpose of degreasing and derusting may be performed as necessary.
Next, the coating material made of the polyimide is coated on the cleaned substrate. As the coating method, a liquid phase method such as a dipping method, a spray method, or a printing method is employed. The coating may be selectively performed on at least the surface on which the guide pair 12 that is the holding portion is formed, without being performed on the entire surface of the base material, that is, on both surfaces and end surfaces thereof. In the case of such selective coating, a spray method using a spray gun and a printing method (transfer method) using a roller are preferably used. Moreover, when coating the whole surface of a base material, an immersion method is used suitably.

When coating is selectively performed using a spray method or a printing method, it is somewhat difficult to perform coating without unevenness, and in particular, the inner wall surfaces of the through holes 16, 17, 18, 19 and the guide grooves 12a, the concave portions It is difficult to coat the inner surface of 14 with a uniform thickness. However, even in that case, for example, it is possible to perform coating with a required uniformity by means of spraying and applying in a state where the spray gun is inclined. And when it coats selectively in this way, compared with the case where it coats on the whole surface, the quantity of a coating material can be decreased and, therefore, material cost can be reduced.
On the other hand, when the entire surface is coated, the amount of the coating material becomes relatively large, but particularly in the case of the immersion method, the coating process can be facilitated and the coating thickness is also made relatively uniform. be able to.

When the coating treatment is performed in this manner, although it varies depending on the composition of the coating material, for example, it is heated at 180 ° C. for about 20 minutes as a drying treatment and further heated at 230 ° C. for about 40 minutes as a main firing treatment.
The coating thickness of the insulating material obtained after the main baking treatment is set to a film thickness that can provide sufficient insulation to the surface of the metal substrate, for example, about 35 μm. Therefore, in particular, when coating is performed on both surfaces (entire surface), the total is about 70 μm. In order to obtain such a coating thickness, the above-described coating process may be repeated a plurality of times as necessary.

  Since the pallet 10 obtained in this way is coated with an insulating material by the liquid phase method in particular, the coating unevenness in which the coating thickness is reduced at the corners and concave portions as in the case of coating by the gas phase method. Therefore, the holding portion (guide pair 12) of the pallet 10 and the concave portion 14 on the surface on which the holding portion is formed are reliably insulated.

  Moreover, when this pallet 10 was heat-processed at 200 degreeC for 12 hours in oven, and the heat resistance was investigated, there was no abnormality, such as a deformation | transformation, Therefore It was confirmed that it is excellent in heat resistance. Moreover, when immersed in IPA (isopropyl alcohol) for 24 hours and then heat-treated at 180 ° C. for 12 hours and examined for its chemical resistance, it was confirmed that there was no abnormality and therefore excellent chemical resistance. . Furthermore, when heated at 180 ° C. for 12 hours and the outgas from the pallet 10 was examined by a gas chromatography method, almost no outgas was generated, and the amount of outgas generated was less than that of a conventional resin pallet. About 40. In addition, the insulation, wear resistance, film adhesion, bending strength, and the like were also examined, and it was confirmed that the performance required as a pallet was sufficiently satisfied.

  Further, in the pallet 10 as described above, the guide pair 12 is formed such that the two guide grooves 12a and 12a are not parallel but opened in a C shape as described above. It has become. That is, as shown in FIG. 4, the interval between the two guide grooves 12a, 12a is the interval W1 at the recess 15 (end edge portion) on the end surface 11 side of the pallet 10, and the two outer leads 4, 4 The distance W on the ring 7 side is narrower than the distance W, and the distance W2 on the recess 14 side is wider than the distance W.

Therefore, when the airtight terminal 1 is held by such a guide pair 12, the outer leads 4, 4 can be easily fitted into the guide grooves 12a, 12a, respectively. That is, since the interval W1 between the two guide grooves 12a, 12a in the recess 15 (end edge portion) on the end surface 11 side of the pallet 10 is narrower than the interval W between the two outer leads 4, 4, these The two outer leads 4, 4 are fitted into the guide grooves 12a, 12a from the ring 7 side and held in the guide grooves 12a, 12a, respectively, so that they are not interfered with the bank portion 13a between the guide grooves 12a, 12a. The two outer leads 4 and 4 can be easily held in the guide grooves 12a and 12a.
Further, since the interval W2 between the two guide grooves 12a, 12a on the concave portion 14 side is wider than the interval W, the two outer leads 4, 4 are simply held in the guide grooves 12a, 12a. Thus, the space between the end portions (tip portions) can be naturally expanded in the recess 14.

Next, a method for manufacturing a piezoelectric vibrator using the pallet 10 of the present invention will be described.
First, the manufacturing process of the piezoelectric vibrator piece will be described according to the manufacturing flowchart shown in FIG. 5, and then the assembly process using the pallet 10 of the present invention will be described. In this example, a quartz fork is used as the piezoelectric vibrator, and a tuning fork type quartz vibrator in which the shape of the vibrator piece is a tuning fork type will be described as an example. The manufacturing method of the present invention can also be applied to a BT vibrator. The manufacturing method of the present invention can also be applied to a vibrator using another piezoelectric material such as LiNbO3 or LiTaO3.

[Piezoelectric vibrator piece manufacturing process]
In the manufacturing process of the piezoelectric vibrator piece, first, a quartz crystal lumbard ore is set on a work table with the aid of an X-ray diffraction method so as to have a predetermined cutting angle. The raw quartz stone is sliced and cut to a thickness of about 200 μm. For cutting, loose abrasive grains are usually used, and a high carbon steel wire having a wire diameter of, for example, about 160 μm is used for the cutting wire (S100).

  Next, the wafer is polished until a certain thickness is reached. In the polishing, rough lapping is usually performed with loose abrasive grains having a coarse particle diameter, and then final lapping is performed with loose abrasive grains having a small particle diameter. Thereafter, the surface is etched to remove the work-affected layer, and further polished and washed to finish a mirror surface having a predetermined thickness and a predetermined flatness (S110).

  Subsequently, a metal thin film for masking (a laminated film of chromium and gold is commonly used) is deposited to a predetermined film thickness using a film forming means such as sputtering. The thin film is deposited on both sides of the wafer (S120).

  Next, the outer shape of the tuning fork vibrator is formed by lithography. Specifically, a resist is applied, and both sides are exposed with an external mask and developed to obtain an external resist pattern. Thereafter, an unnecessary metal pattern is removed with an etching solution to obtain a metal mask pattern. After removing the resist, the crystal is etched with a hydrofluoric acid aqueous solution to form a plurality of external shapes on the wafer. Along with the downsizing of the piezoelectric vibrator described above, the ratio of the width of the vibrating arm to the thickness of the vibrating arm (vibrating arm width / vibrating arm thickness) has become a small value. In particular, when this ratio is smaller than 1.0, the electric field efficiency with respect to the vibrating arm of the tuning fork vibrator decreases, and the resonance resistance value of the vibrator increases. For example, the value exceeds 100 kΩ, which is not desirable as a vibrator. As a countermeasure, a groove is formed in the vibrating arm for the purpose of increasing the electrolytic efficiency and lowering the resonance resistance value (S130).

  Thus, after forming the outer shape and the groove, all the metal film used as the mask is once peeled off. After peeling, a metal thin film that becomes an electrode film with a predetermined film thickness is again deposited on both surfaces of the wafer with a predetermined film thickness by a film forming means such as sputtering (S140). When the groove is formed, the film is also formed on the inner surface of the groove. After the film is deposited, a pattern of the electrode film is formed using the lithography technique in the same manner as the above-described outer shape forming process (S150).

Next, after forming a weight film with a thickness of several microns on the tip region of the vibrating arm, the weight part is irradiated with a laser or the like in the atmosphere to measure the oscillation frequency, and one of the deposited weight films. The part is evaporated and the frequency is adjusted to a predetermined range. As the weight material, a laminated film of chromium, silver or gold is commonly used. After the frequency adjustment, the wafer is ultrasonically cleaned to remove the film residue and adhered foreign matter generated by the frequency adjustment (S160).
A wafer having a plurality of piezoelectric vibrator pieces is completed by the above-described steps.

[Piezoelectric vibrator assembly process (piezoelectric vibrator manufacturing method)]
Subsequently, according to the manufacturing flowchart of the piezoelectric vibrator assembly process shown in FIG. 5, the piezoelectric vibrator assembly process will be described with reference to the explanatory diagrams of FIGS. 6 to 8.
First, the hermetic terminal 1 and the case 20 are baked at predetermined temperatures, respectively, to sufficiently desorb moisture, released gas components, and the like attached to the surface during storage (S200).

  Subsequently, an airtight terminal mounting process is performed for aligning a plurality of airtight terminals 1 on the pallet 10 of the present invention (S210). In mounting the airtight terminals 1, a dedicated mounting jig (not shown) is used to hold the airtight terminals 1 for all the guide pairs 12 as shown in FIG. In mounting the airtight terminal 1 on the pallet 10, the airtight terminal 1 set in advance on the mounting jig is fitted into the guide pair 12 of the pallet 10 so that the tip of the outer lead 4 is inserted. Thus, the airtight terminal 1 can be easily held by the guide pair 12. At this time, since the intervals W1 and W2 between the guide grooves 12a and 12a are formed as described above with respect to the interval W between the outer leads 4 and 4, the end portions (tip portions) of the outer leads 4 and 4 are formed. The space naturally expands in the recess 14.

  When the airtight terminals 1 are all held by the guide pair 12 in this way, the heat-resistant tape 35 is stuck on the guide pair 12 in this state, and the outer leads 4 of the airtight terminals 1 are fixed to the pallet 10. Here, the heat-resistant tape 35 that has been degassed in advance is used. The heat-resistant tape 35 is attached by, for example, temporarily attaching one end of the heat-resistant tape 35 to the pallet 10 and then running a roller along the length direction of the tape 35.

  Next, a vibration piece mounting step is performed (S220). In this mounting process, as shown in FIG. 6, the piezoelectric vibrator piece 8 manufactured in the above-described piezoelectric vibrator piece manufacturing process is joined to the inner lead 3 of the airtight terminal 1. That is, first, the piezoelectric vibrator piece 8 is cut out by a laser or mechanical means from a connecting portion (not shown) that connects each piezoelectric vibrator piece 8 and the wafer, and then the piezoelectric vibrator piece 8 is moved to the inner portion. Align with the lead 3. Next, the plating layer (not shown) of the inner lead 3 is melted by applying heat from the outside, and joined to the mount pad 9 formed on the piezoelectric vibrator piece 8. As a method for melting the plating layer, a method using laser, light source heating, arc discharge heat, or the like can be employed. Alternatively, it is also possible to connect the piezoelectric vibrator pieces 8 with a conductive adhesive or the like without using the plating layer of the inner lead 3.

  Next, baking is performed by heating the pallet 10 holding the hermetic terminal 1 after the mounting process to a predetermined temperature in a vacuum apparatus serving as a vacuum baking furnace (S230). Thereby, distortion generated in the mounting process can be removed (eliminated). In this baking process, heat treatment is usually performed at a temperature of about 150 ° C. to 220 ° C. for a few hours to a few dozen hours. In this embodiment, heat treatment is performed at about 180 ° C. for about 10 hours. When the heat treatment is performed in this manner, the base material of the pallet 10 is made of stainless steel (metal) and is coated with an insulating material made of polyimide (insulating resin), but as described above, there is almost no outgas, As in the case where the entire conventional pallet is made of resin, inconveniences such as “part of the remaining solvent and resin decomposition products are generated as gas” are avoided, and the amount of released gas is very small. The inside is maintained at a high vacuum. Further, since the amount of released gas is small, the amount of organic matter adsorbed and deposited on the surface of the vacuum processing chamber constituting the vacuum baking furnace is reduced, and therefore the cleanness of the surface of the processing chamber is maintained over a long period of time.

  Furthermore, since the pallet 10 is small and sufficiently thin, its heat capacity is relatively small. Therefore, the hermetic terminal 1 and the piezoelectric vibrator piece 8 aligned and held in the pallet 10 have a rapid temperature rise and a temperature distribution. Variations are reduced. Therefore, the distortion of the piezoelectric vibrator piece 8 generated in the mounting process is satisfactorily removed. When a conductive adhesive is used, after the adhesive curing process, the gas component of the adhesive is released by being held at a high temperature. Even in this case, the pallet 10 is excellent in heat resistance as described above. Therefore, it is possible to maintain a sufficiently high temperature.

  Next, a frequency adjustment (fine adjustment) step is performed. That is, each pallet 10 is fed into a vacuum device, and as shown in FIG. 7, the end of the outer lead 4 located in the recess 14 of the pallet 10 is probed at the probe position 32 to vibrate the piezoelectric vibrator piece 8. Measure the transmission frequency. Then, while the oscillation frequency is measured in this way, the frequency adjustment region 34 of the vibrating arm of the piezoelectric vibrator piece 8 is irradiated with laser, the adjustment metal film is evaporated, and the frequency is adjusted (S240).

  When the frequency is finely adjusted in this way, the pallet 10 is coated with an insulating material on the base material, and thus the coating surface is insulative, so that the individual airtight terminals 1 are electrically separated from each other. Has been. Therefore, even if the piezoelectric vibrators 8 are simultaneously oscillated in the state of being aligned with the pallet 10, the individual hermetic terminals 1 do not receive the interference of the adjacent hermetic terminals 1. Also, since the outer leads 4 and 4 have a wide interval between the end portions in the recess 14, the hermetic terminal 1 is downsized, and the outer lead 4 has a smaller wire diameter or the outer lead 4. Even if the distance between the four is very narrow, the probe can be easily and accurately applied to them.

  In particular, since the end portions of the outer leads 4 and 4 are positioned in the recess 14, the end portions of the outer lead 4 are opened without being closed by the bank portion 13 as shown in FIG. 3. (Exposed). Therefore, the contactable area of the probe is increased accordingly, and the probe can be easily and accurately applied to the outer lead 4.

  Next, a plurality of pallets 10 holding the hermetic terminals 1 after the frequency fine adjustment of the piezoelectric vibrator piece 8 are arranged in a mold (not shown), and a sealing case 20 is arranged opposite to the pallet 10. Arrange them. And in order to desorb | suck the water | moisture content and gas component which were adsorb | sucked by the process before sealing, these airtight terminals 1 (pallet 10) and the case 20 are put in a sealing device, and are fully heated by vacuum. Thereafter, as shown in FIG. 8, the case 20 is press-fitted into the ring 7 of the airtight terminal 1, and the piezoelectric vibrator piece 8 is vacuum-tightly sealed in the case 20 (S250). When the vacuum hermetic sealing is performed in this way, the fitting portion between the case 20 and the ring 7 is airtight by the plating layer made of a soft metal on the outer surface of the ring 7 and the case 20 designed to be fitted thereto. Retained. Thereby, a piezoelectric vibrator is obtained.

Here, when the entire pallet is made of resin as in the prior art, in this press-fitting step (S250), there is a problem that the degree of vacuum is lowered during heating due to gas released from the resin pallet. However, by using the pallet 10 in which a polyimide (insulating material) is coated on a stainless steel (metal) base material as in this embodiment, the problem of a decrease in the degree of vacuum can be solved. In addition, the heating temperature is excellent in heat resistance as described above, so it can be set to a temperature equal to or higher than that of the conventional one. It becomes possible to shorten the process time.
Thereafter, screening is performed at a predetermined temperature for the purpose of stabilizing the oscillation frequency.

  Thereafter, the piezoelectric vibrator is removed from the pallet 10 using a jig (S260). The pallet 10 after the piezoelectric vibrator is removed is reused. When reusing, remove plating residue and the like adhering to the previous use by ultrasonic cleaning before use, and evaporate the moisture in a drying furnace or the like. Since it is a stainless steel coated with polyimide and is thin, it is easy to clean and dry. By performing such a cleaning process, it is possible to prevent defects in the assembly process due to foreign matter or the like even in the case of reuse. Further, the pallet 10 thus washed and dried is returned to S210 and reused.

  On the other hand, the piezoelectric vibrator removed from the pallet 10 is inspected for oscillation frequency, resonance resistance value, and other electrical characteristics by an electrical characteristic inspection device (S270). In this electrical characteristic inspection step, each characteristic is measured by probing the outer lead 4 of the piezoelectric vibrator. The tuning fork crystal unit is completed through the above steps.

In the pallet 10 used in such a manufacturing method, an adverse effect due to outgassing is suppressed, the deformation is hardly caused even by repeated use, and the outer diameter is adjusted in the step of finely adjusting the frequency of the piezoelectric vibrator piece. The conduction between the leads 4 and 4 can be reliably prevented. Therefore, the cost can be reduced by enabling repeated use.
Further, since the two outer leads 4 and 4 of the hermetic terminal 1 can be easily held in the guide grooves 12a and 12a, respectively, for example, a miniaturized hermetic terminal can be easily used in the piezoelectric vibrator assembly process. It can be made to flow.
Further, in the method of manufacturing a piezoelectric vibrator using the pallet 10, the hermetic terminal 1 can be easily flowed into the piezoelectric vibrator assembling process by using the pallet 10, and further, the piezoelectric vibrator piece. The processing in the step of finely adjusting the frequency can be facilitated.

[Piezoelectric vibrator]
Next, as an embodiment of the piezoelectric vibrator manufactured by the manufacturing process described above, FIG. 9 shows the configuration of a cylinder-type piezoelectric vibrator in which a tuning-fork type quartz vibrator piece is sealed with a bottomed cylindrical case. The description will be given with reference.
FIG. 9 is a schematic configuration diagram showing an embodiment of a piezoelectric vibrator according to the present invention. In FIG. 9, reference numeral 40 denotes a piezoelectric vibrator having a tuning-fork type piezoelectric vibrator piece 8. Excitation electrodes (not shown) are formed on the surface of the piezoelectric vibrator piece 8. Further, the weight of the vibrating arm of the piezoelectric vibrator piece 8 is provided with a weight so that the piezoelectric vibrator piece 8 is adjusted to a predetermined frequency.

  The mount pad 9 disposed at the base of the piezoelectric vibrator piece 8 is a tip on the inner lead 3 side of the two leads 2 penetrating through the substantially cylindrical ring 7 and the filler 5 filled in the ring 7. Further, the plating (not shown) formed on the surface layer of the inner lead 3 is melted and fixed. A case 20 indicated by a two-dot chain line is attached so as to cover the piezoelectric vibrator piece 8, and the case 20 is fitted to the outer peripheral surface of the ring 7. Since the fitting between the case 20 and the outer periphery of the ring 7 is performed in a vacuum atmosphere as described above, the space surrounding the piezoelectric vibrator piece 8 in the case 20 is maintained in a high vacuum state and sealed. ing.

  The excitation electrode formed on the surface of the piezoelectric vibrator piece 8 is connected to the two leads 2 (inner leads 3) through the mount pad 9 formed on the base. The lead 2 is extended outside the ring 7 to form an external electrode (outer lead 4). A plating layer (not shown) is formed on the surface of the outer lead 4 and has sufficient wettability with respect to solder for board mounting.

  The piezoelectric vibrator 40 having such a structure is manufactured by flowing the process while the hermetic terminal 1 is easily held on the pallet 10 in the assembly process, and in particular, the frequency of the piezoelectric vibrator piece 8 is set. Since the processing in the fine adjustment process is also easy, the productivity is good, and therefore the production cost is reduced.

[Oscillator]
FIG. 10 is a schematic diagram showing the configuration of a tuning fork type crystal oscillator according to the present invention, and shows a plan view of a surface mount type piezoelectric oscillator using the above-described piezoelectric vibrator (tuning fork type crystal vibrator). As shown in FIG. 10, the oscillator 100 of this embodiment is configured by configuring a cylinder package type piezoelectric vibrator 40 as an oscillator electrically connected to an integrated circuit 101. Since the piezoelectric vibrator 40 is the same as that of the above-described embodiment, the description thereof is omitted. The oscillator 100 includes a substrate 103 on which an electronic component 102 such as a capacitor is mounted. An integrated circuit 101 for an oscillator is mounted on the substrate 103, and the piezoelectric vibrator 40 is mounted in the vicinity of the integrated circuit 101. The electronic component 102, the integrated circuit 101, and the piezoelectric vibrator 40 are electrically connected by a wiring pattern (not shown). Each component is molded with a resin (not shown).

  In the oscillator 100 configured as described above, when a voltage is applied to the piezoelectric vibrator 40, the piezoelectric vibrator piece 2 in the piezoelectric vibrator 40 vibrates, and this vibration is converted into an electric signal by the piezoelectric characteristics of the crystal, The signal is input to the integrated circuit 101 as an electrical signal. The input electrical signal is subjected to various processes by the integrated circuit 101 and is output as a frequency signal. Thereby, the piezoelectric vibrator 40 functions as an oscillator. Further, by selectively setting the configuration of the integrated circuit 101, for example, an RTC (real-time clock) module or the like according to a request, the operation date and time of the device and the external device in addition to a single-function oscillator for a clock, etc. A function for controlling the time, providing a time, a calendar, and the like can be added.

  As described above, according to the oscillator 100 of the present embodiment, by providing the piezoelectric vibrator 40 that is small as described above and does not cause a short circuit, it is possible to provide a small and highly reliable oscillator. it can.

[Electronics]
Next, as an electronic device according to the present invention, a portable information device having the piezoelectric vibrator 40 described above will be described as an example. FIG. 11 is a block diagram showing the configuration of the electronic device. As shown in FIG. 11, the portable information device 110 of this embodiment includes a piezoelectric vibrator 40 and a power supply unit 111 for supplying power. The power supply unit 111 is composed of, for example, a lithium secondary battery. The power supply unit 111 includes a control unit 112 that performs various controls, a clock unit 113 that counts time, a communication unit 114 that communicates with the outside, a display unit 115 that displays various types of information, A voltage detection unit 116 that detects the voltage of the functional unit is connected in parallel. The power unit 111 supplies power to each functional unit.

  The control unit 112 controls each function unit to control operation of the entire shilling, such as transmission and reception of audio data, measurement and display of the current time, and the like. The control unit 112 includes a ROM in which a program is written in advance, a CPU that reads and executes the program written in the ROM, and a RAM that is used as a work area of the CPU.

  The time measuring unit 113 includes an integrated circuit including an oscillation circuit, a register circuit, a counter circuit, an interface circuit, and the like, and the piezoelectric vibrator 40. When a voltage is applied to the piezoelectric vibrator 40, the piezoelectric vibrator piece 2 vibrates, and this vibration is converted into an electric signal by the piezoelectric characteristics of the crystal and is input to the oscillation circuit as an electric signal. The output of the oscillation circuit is binarized and counted by a register circuit and a counter circuit. Then, signals are transmitted to and received from the control unit 112 via the interface circuit, and the current time, current date, calendar information, or the like is displayed on the display unit 115.

  The communication unit 114 has functions similar to those of a conventional mobile phone, and includes a radio unit 117, a voice processing unit 118, a switching unit 119, an amplification unit 120, a voice input / output unit 121, a telephone number input unit 122, and a ring tone generation unit. 123 and a call control memory unit 124. The wireless unit 117 exchanges various data such as audio data with the base station via the antenna 125. The audio processing unit 118 encodes and decodes the audio signal input from the radio unit 117 or the amplification unit 120. The amplifying unit 120 amplifies the signal input from the audio processing unit 118 or the audio input / output unit 121 to a predetermined level. The voice input / output unit 121 includes a speaker, a microphone, and the like, and amplifies a ringtone and a received voice or collects a voice.

  In addition, the ring tone generator 123 generates a ring tone in response to a call from the base station. The switching unit 119 switches the amplifying unit 120 connected to the voice processing unit 118 to the ringing tone generating unit 123 only when an incoming call is received, so that the ringing tone generated in the ringing tone generating unit 123 is transmitted via the amplifying unit 120. To the audio input / output unit 121. The call control memory unit 124 stores a program related to incoming / outgoing call control of communication. The telephone number input unit 122 includes, for example, a number key from 0 to 9 and other keys. By pressing these number keys and the like, a telephone number of a call destination is input.

  When the voltage applied to each functional unit such as the control unit 112 by the power supply unit 111 falls below a predetermined value, the voltage detection unit 116 detects the voltage drop and notifies the control unit 112 of the voltage drop. . The predetermined voltage value at this time is a value set in advance as a minimum voltage necessary for stably operating the communication unit 114, and is, for example, about 3V. Upon receiving the voltage drop notification from the voltage detection unit 116, the control unit 112 prohibits the operations of the radio unit 117, the voice processing unit 118, the switching unit 119, and the ring tone generation unit 123. In particular, it is essential to stop the operation of the wireless unit 117 with high power consumption. Further, the display unit 115 displays that the communication unit 114 has become unusable due to insufficient battery power.

  That is, the operation of the communication unit 114 can be prohibited by the voltage detection unit 116 and the control unit 112, and that effect can be displayed on the display unit 115. This display may be a text message, but as a more intuitive display, a x (X) mark may be attached to the telephone icon displayed at the top of the display surface of the display unit 115. Note that the portable information device 110 includes a power shut-off unit 126 that can selectively shut off the power of the part related to the function of the communication unit 114, and the function of the communication unit 114 is controlled by the power shut-off unit 126. Stop surely.

  According to the portable information device 110 of this embodiment, it is possible to provide a small and highly reliable portable information device by including the piezoelectric vibrator 40 that is small and does not cause a short circuit as described above. it can.

[Radio clock]
Next, a radio timepiece according to the present invention will be described. FIG. 12 is a block diagram showing a configuration of one embodiment of this radio timepiece. As shown in FIG. 12, a radio timepiece 130 of this embodiment includes a piezoelectric vibrator 40 electrically connected to a filter unit 131, and receives a standard radio wave including timepiece information to accurately It is a clock with a function of automatically correcting and displaying the correct time. In Japan, there are transmitting stations (transmitting stations) that transmit standard radio waves in Fukushima Prefecture (40 kHz) and Saga Prefecture (60 kHz), each transmitting standard radio waves. Long waves such as 40 kHz or 60 kHz have the property of propagating the surface of the earth and the property of propagating while reflecting the ionosphere and the surface of the earth, so the propagation range is wide and the above two transmitting stations cover all of Japan is doing.

  The antenna 132 receives a long standard wave of 40 kHz or 60 kHz. The long-wave standard radio wave is obtained by subjecting time information called a time code to AM modulation on a 40 kHz or 60 kHz carrier wave. The received long standard wave is amplified by the amplifier 133 and filtered and tuned by the filter unit 131 having the plurality of piezoelectric vibrators 40. The piezoelectric vibrator 40 includes piezoelectric vibrator portions 134 and 135 having resonance frequencies of 40 kHz and 60 kHz that are the same as the carrier frequency.

  Further, the filtered signal having a predetermined frequency is detected and demodulated by the detection and rectification circuit 136. Then, the time code is taken out via the waveform shaping circuit 137 and counted by the CPU 138. The CPU 138 reads information such as the current year, accumulated date, day of the week, and time. The read information is reflected on the RTC 139, and accurate time information is displayed. Since the carrier wave is 40 kHz or 60 kHz, the piezoelectric vibrators 134 and 135 are preferably piezoelectric vibrators having the tuning fork type structure described above. Taking 60 kHz as an example, as a dimension example of the tuning fork type vibrator piece, it is possible to configure the tuning fork vibrator piece with a length of about 2.8 mm and a width of the base portion of about 0.5 mm.

  According to the radio timepiece 130 of this embodiment, a small and highly reliable radio timepiece can be provided by including the piezoelectric vibrator 40 that is small and does not cause a short circuit as described above.

As described above, the embodiment of the present invention has been described in detail with reference to the drawings. However, the vibration mode is not limited to the bending vibration that is a tuning fork type, and is a vibration piece of another vibration mode such as a thickness-shear vibration mode. Also good. Further, the piezoelectric material is not limited to quartz, and may be a piezoelectric material such as lithium niobate, lithium tantalate, or langasite.
The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the gist of the present invention. For example, in the pallet of the above embodiment, stainless steel is used as the base material, but other metals or alloys can also be used. Furthermore, in the said embodiment, although insulating resin was used as an insulating material coated on a base material, glass can also be used as an insulating material, for example. In that case, glass can be coated on the base material by a liquid phase method by melting the glass and immersing and pulling up the base material in the glass.

(A), (b) is a figure which shows one Embodiment of the pallet of this invention. It is a top view which shows the state holding the airtight terminal of the pallet shown in FIG. FIG. 3 is a cross-sectional view taken along line B-B in FIG. 2. FIG. 3 is an enlarged view of a main part of FIG. 2. 4 is a flowchart for explaining a manufacturing process of a piezoelectric vibrator. It is a manufacturing process explanatory drawing of a piezoelectric vibrator. It is a manufacturing process explanatory drawing of a piezoelectric vibrator. It is a manufacturing process explanatory drawing of a piezoelectric vibrator. It is a schematic block diagram which shows one Embodiment of the piezoelectric vibrator which concerns on this invention. 1 is a schematic diagram of an oscillator according to the present invention. It is a block diagram of the electronic device which concerns on this invention. 1 is a block diagram of a radio timepiece according to the present invention. (A), (b) is a schematic diagram which shows an airtight terminal and a cylinder type case (package).

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Piezoelectric vibrator, 2 ... Lead, 3 ... Inner lead, 4 ... Outer lead, 5 ... Filler, 7 ... Ring, 8 ... Piezoelectric vibrator piece, 10 ... Pallet, 11 ... End face, 12 ... Guide pair (holding) Part), 12a ... guide groove, 14 ... recess, 20 ... case, 40 ... pressure vibrator

Claims (7)

An annular ring is disposed in a state of penetrating the ring, and one end side is an inner lead electrically connected to the piezoelectric vibrator piece across the ring, and the other end side is electrically connected to the outside. A pallet having a holding portion for holding an airtight terminal for joining a piezoelectric vibrator piece to the inner lead,
A metal plate-like base material;
A pallet comprising: an insulating material coated with a liquid phase method on at least a surface of the base material on which the holding portion is formed.   The pallet according to claim 1, wherein an insulating resin is used as the insulating material.   The pallet according to claim 2, wherein the insulating resin is polyimide.   The holding portion is formed by a guide pair including two guide grooves each holding the two outer leads of the hermetic terminal, with one end of each guide groove opening to the end face side of the pallet. The pallet as described in any one of Claims 1-3 characterized by the above-mentioned.   A groove-shaped recess that communicates with the other end of the guide groove and positions the end of the outer lead held in the guide groove is formed along the length direction of the end surface of the pallet. The pallet according to claim 4.   The interval between the two guide grooves forming the guide pair is such that the interval W1 at the end edge on the end surface side of the pallet is narrower than the interval W on the ring side of the two outer leads, and on the recess side. The pallet according to claim 5, wherein the interval W2 is wider than the interval W. An annular ring is disposed in a state of penetrating the ring, and one end side is an inner lead electrically connected to the piezoelectric vibrator piece across the ring, and the other end side is electrically connected to the outside. A piezoelectric vibrator piece is joined to the inner lead of an airtight terminal having two leads as outer leads, and then the frequency of the piezoelectric vibrator piece is finely adjusted, and then the piezoelectric vibration A method of manufacturing a piezoelectric vibrator, covering a child piece and press-fitting a case into the ring of the hermetic terminal,
The two outer leads of the airtight terminal are held by the holding portion of the pallet according to any one of claims 1 to 6, and the airtight terminal is allowed to flow into the piezoelectric vibrator assembly process in that state. A method for manufacturing a piezoelectric vibrator.

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