JP2013098610A - Manufacturing method of electronic device - Google Patents

Abstract

A sealing member is reliably prevented from being scattered by a gas discharged from a sealing hole by a simple method without using a cover plate that causes a decrease in productivity.
A step of setting a container so that a sealing hole is facing upward; a step of arranging a sealing member on the sealing hole; and a first melting step of melting the sealing member; A container that has undergone the first melting step is placed in a chamber, and a decompression step that decompresses the interior of the chamber by decompressing the interior of the chamber, and a second process that melts the sealing member in a state where the cavity is decompressed. 2 and a step of opening the chamber to the atmosphere. In the first melting step, the sealing member is fixed in the sealing hole in a state in which communication between the empty space of the container and the outside of the container is ensured. To do.
[Selection] Figure 7

Description

  The present invention relates to an improvement in a method for manufacturing an electronic device in which a piezoelectric vibration element and other electronic components are accommodated in a container.

In recent years, in small information devices such as HDDs (hard disk drives), mobile computers, and IC cards, and mobile communication devices such as mobile phones, car phones, and paging systems, the size and thickness of devices have been dramatically reduced. The piezoelectric devices used for them are also required to be small and thin. In addition, there is a need for a surface-mount type piezoelectric device that can be surface-mounted on a circuit board of the apparatus.
In the manufacturing process of an electronic device having a structure in which a piezoelectric vibration element is hermetically sealed in a container like a piezoelectric vibrator, after the piezoelectric vibration element is accommodated in a container having a sealing hole, the container is The gas inside the container is discharged from the sealing hole by being placed in a vacuum chamber and heated while being vacuumed, and the sealing hole is sealed using a sealing member when the discharge is completed.
In the sealing step, the container is set so that the sealing hole faces upward in the vacuum chamber, and a spherical metal sealing member is placed so as to close the sealing hole, and then the laser beam is applied to the sealing member. The sealing hole is sealed by irradiation and melting (Patent Document 1).
With the miniaturization of electronic devices, the sealing member is also miniaturized. For example, metal balls having a diameter of about 0.3 mm are used. Such a small, lightweight metal sphere is easily pushed out of the container by the gas discharged from the inside of the container through the sealing hole when vacuumed, and the sealing process cannot be carried out when scattered. This is a cause of reducing the productivity of the piezoelectric device.
In order to prevent the sealing member from being scattered by evacuation, the evacuation speed is reduced, but not only the cost for remodeling the vacuum chamber is increased, but the productivity is lowered. This is a cause of deterioration of the properties of the finished product due to a decrease in the degree of vacuum in the electronic device and variations.

On the other hand, Patent Document 2 discloses a method for manufacturing a small piezoelectric device capable of hermetically sealing a piezoelectric vibration element in a container. In this manufacturing method, a spherical sealing member is disposed in a sealing hole of a container disposed in a vacuum chamber, and then the inside of the container is decompressed by depressurizing the inside of the vacuum chamber, and the inner periphery of the sealing hole and the sealing are sealed. The gas inside the container is discharged to the outside through a gap with the member. At this time, the cover plate is arranged so that the gap between the outer bottom surface of the container in which the sealing hole is formed and the cover plate is smaller than the diameter of the sealing member. When a spherical sealing member tries to jump out of the sealing hole due to the pressure of the gas discharged from the internal space, the sealing member is received by the cover plate.
However, when the container is downsized to a few mm square, a spherical sealing member for sealing the sealing hole formed in the container has a diameter of 1 mm or less, for example, and a plurality of spherical sealing members are set on the tray. It is extremely difficult to maintain a proper gap between all the containers and the cover. In addition, there is a problem that productivity decreases as the work for preparing and setting and removing the cover plate increases.

JP 2003-158439 A JP 2011-129735 A

  The present invention has been made in view of the above, and it is ensured that the sealing member is scattered by the gas discharged from the sealing hole by a simple method without using a cover plate that causes a decrease in productivity. An object of the present invention is to provide a method of manufacturing an electronic device that can be prevented.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

  Application Example 1 An electronic device manufacturing method according to the present invention includes a container having a void inside and a sealing hole for communicating the void with the outside of the container, and sealing the sealing hole. A sealing member and an electronic component housed in the container, wherein the electronic component is housed in a void of the container; and at least one of the sealing member A sealing member disposing step of disposing a portion in the sealing hole, and a first melting step of fixing the sealing member to the container in a state in which communication between the void of the container and the outside of the container is ensured A decompression step of decompressing the void of the container after the first melting step; a second melting step of sealing the container by melting the sealing member after the decompression step; , Including.

  According to this application example, before the decompression step and the main sealing step, a cover plate that causes a decrease in productivity is used to perform a melting step for temporarily fixing the sealing member to the sealing hole. In addition, it is possible to reliably prevent the sealing member from being scattered by the gas discharged from the sealing hole by a simple method.

  Application Example 2 In the method for manufacturing an electronic device according to the present invention, laser light irradiation means is prepared, and the optical axis of the laser is shifted from the center of the sealing member in plan view to the outer shape side. The laser beam is irradiated to melt the sealing member.

  According to this application example, the laser beam is irradiated to a position off the central portion of the sealing member, so the portion irradiated with the laser beam and its periphery are melted in advance, and the other separated portions are delayed. Melt. For this reason, it can fix by the part fuse | melted ahead, forming the clearance gap for ventilation between the sealing hole and the sealing member part melt | dissolved late.

  Application Example 3 In the method of manufacturing an electronic device according to the present invention, the energy amount of the laser beam applied to the sealing member in the first melting step is obtained by melting and solidifying the entire sealing member. The amount of energy required to completely seal the sealing hole is 80% or less.

  According to this application example, it becomes easy to adjust the amount of energy for melting the sealing member by laser irradiation in temporary fixing, and productivity can be improved.

1 is a schematic plan view of a first embodiment of a piezoelectric device of the present invention. FIG. 2 is a schematic sectional view taken along line XX in FIG. 1. It is a bottom view of FIG. (A) And (b) is a longitudinal cross-sectional view which shows the procedure which mounts a piezoelectric vibration element in a container main body, and explanatory drawing which shows the procedure which joins a cover body. (A) And (b) is a figure explaining the sealing method using a laser beam, and the principal part enlarged view. It is a flowchart explaining the manufacturing method of the electronic device which concerns on this invention. (A) And (b) is explanatory drawing which shows the case where a laser beam is irradiated toward the center part of a sealing member in a 1st melting process, and sectional drawing which shows the sealing member temporarily fixed. (A) And (b) is explanatory drawing which shows the case where a laser beam is irradiated to the position which shifted | deviated from the center part of the sealing member in the 1st fusion | melting process, and sectional drawing which shows the sealing member temporarily fixed. . The amount of energy required to temporarily fix the sealing member in the first melting step (J) and the amount of energy required to fully seal the sealing hole by melting the sealing member in an unmelted state (J) ). It is a figure which shows the state which has arrange | positioned the container which temporarily fixed the sealing member in the vacuum chamber. It is the figure which showed an example of the temperature profile in a pressure reduction process. (A) is a schematic plan view which shows the structure of different embodiment of the piezoelectric device of this invention, (b) is a XX sectional schematic drawing of (a). 1 is a diagram illustrating a schematic configuration of a digital mobile phone device as an example of an electronic apparatus using a piezoelectric device according to an embodiment of the present invention.

Hereinafter, the present invention will be described in detail with reference to embodiments shown in the drawings.
1 to 3 show a first embodiment of a piezoelectric device as an example of an electronic device of the present invention, FIG. 1 is a schematic plan view thereof, and FIG. 2 is a schematic cross-sectional view taken along line XX of FIG. FIG. 3 and FIG. 3 are bottom views of FIG.
In these drawings, a piezoelectric vibrator is illustrated as the piezoelectric device 1, and the piezoelectric device 1 has a configuration in which a piezoelectric vibration element (electronic component) 30 is hermetically sealed in a container 2.
The container 2 includes a container main body 3 and a lid body 20 that is assembled to hermetically seal the piezoelectric vibration element 30 mounted on the container main body 3.
The container body 3 is formed of a substrate such as an aluminum oxide sintered body obtained by laminating and sintering ceramic green sheets. Each of the plurality of substrates is formed with a predetermined hole on the inner side thereof so that a predetermined inner space S is formed on the inner side when stacked. That is, as shown in FIG. 2, the container body 3 of the present embodiment includes, for example, a flat plate-like first laminated substrate 11, an annular second laminated substrate 12 overlaid thereon, and an overlaid thereon. And an annular third laminated substrate 13.
In the vicinity of the left end portion in the internal space S of the container main body 3, the second laminated substrate 12 that is exposed to the internal space S and forms the bottom portion is provided with electrode portions 15 and 15 plated with Au and Ni. Is provided. The electrode portions 15 and 15 are connected to the outside to supply a driving voltage. Conductive adhesives 16, 16 are applied on the electrode parts 15, 15, and a base 31 of the piezoelectric vibration element 30 is placed on the conductive adhesives 16, 16, so that the conductive adhesives 16, 16 are placed. Is cured.

An extraction electrode (not shown) for transmitting a driving voltage is formed on a portion of the base 31 of the piezoelectric vibration element 30 that is in contact with the conductive adhesives 16 and 16, whereby the piezoelectric vibration element 30 is driven. The electrode is electrically connected to the electrode parts 15 and 15 on the container body 3 side via the conductive adhesives 16 and 16.
The piezoelectric substrate constituting the piezoelectric vibration element 30 is made of, for example, quartz, and a piezoelectric material such as lithium tantalate or lithium niobate can be used in addition to the quartz. In the case of this embodiment, the piezoelectric vibration element 30 includes a base 31 fixed to the container body 3 side, and a pair of vibrating arms 34 and 35 extending from the base 31 in a bifurcated manner toward the right side of the drawing. A so-called tuning fork type piezoelectric vibration element is used which has a tuning fork shape as a whole.
The open upper surface of the container body 3 is sealed by joining a metal lid 20 via a brazing material 33 such as low melting point glass.

In addition, by substantially forming first and second through holes 37a and 37b in the two laminated substrates 11 and 12 constituting the bottom plate of the container body 3 in the vicinity of the center of the bottom surface of the container body 3, respectively. A sealing hole 37 as a through hole is provided. Out of the two through holes constituting the sealing hole 37, the outer second through hole 37b is concentrically provided with a larger inner diameter with respect to the first through hole 37a opened inside the container body. It is configured. As a result, the sealing hole 37 is an opening having a stepped portion 40. Preferably, a metal ball which is a sealing member 38 to be described later is provided on the stepped portion of the through hole 37b and the inner peripheral surface of the through hole 37a. (For example, a gold germanium alloy (Au / Ge)) is coated with a metal having good wettability, such as gold plating, on a predetermined base layer.
That is, after fixing the piezoelectric vibration element 30 in the container body 3, the sealing hole 37 is melt-filled with a sealing member (metal sealing member) 38, so that the inside of the container body 3 is airtight. To seal.

In this example, a gold germanium alloy (Au / Ge) is used as the sealing member 38 filled in the sealing hole 37, as will be described in detail in a sealing process described later. An arbitrary metal material can be used as the sealing member.
Further, in this embodiment, the second laminated substrate 12 constituting the container body 3 is formed with a recess 42 corresponding to the thickness of the laminated substrate 12 by forming a hole near the right end of the drawing. . The recess 42 is located below the piezoelectric vibration element 30. Thus, in the present embodiment, when an external impact is applied to the container body 3, even when the free end of the piezoelectric vibration element 30 is displaced in the direction of arrow D and shakes, the container body 3 contacts the inner bottom surface. To prevent it.

  The piezoelectric device 1 according to the present embodiment is configured as described above, and the sealing hole 37 provided in the container body 3 is sealed with a sealing member 38 made of a gold germanium alloy (Au / Ge). For this reason, when heat is applied in the process of mounting the piezoelectric device 1 after sealing, the gold germanium alloy has a high melting point and does not melt easily. Leakage due to partial melting is effectively prevented. In addition, since the sealing member 38 does not contain lead, environmental pollution caused by lead can be avoided.

Next, the electronic device manufacturing method of the present invention has the following characteristic configuration.
That is, in the present invention, the container 2 having the void S inside and the sealing hole 37 for communicating the void with the outside of the container is melted with the container 2 having the outer wall (laminated substrate 11, 12 or lid 20). A method of manufacturing an electronic device having a sealing member 38 that seals the sealing hole 37 by solidification later, and an electronic component 30 that is hermetically sealed in a container that is sealed with the sealing hole. It is about.
The first characteristic configuration of the manufacturing method according to the present invention includes a step of accommodating an electronic component in a container, a container setting step of setting the container 2 so that the sealing hole 37 faces upward, and a sealing member A sealing member disposing step of disposing 38 on the sealing hole, a first melting step of melting and solidifying the sealing member 38 (temporary fixing step of the sealing member), and a first melting step. A decompression step of placing the container in which the sealing member is temporarily fixed in the chamber and depressurizing the internal space S of the container through the gap between the sealing hole and the sealing member by decompressing the inside of the chamber; And a second melting step (main sealing step) for melting and solidifying the sealing member in a state where the internal space is decompressed, and in the first melting step, the internal space of the container and the container In a state in which communication with the outside is ensured, a sealing member is placed in the sealing hole and / or the peripheral edge of the sealing hole. It lies in the fact that as a constant.

A second characteristic configuration of the manufacturing method according to the present invention is that the first melting step is a step of irradiating and melting a substantially spherical sealing member with a laser beam, and sealing the laser beam. The position of the optical axis at the time of irradiating the member is a position deviated from the central portion of the sealing member in the outer radial direction.
The third characteristic configuration of the manufacturing method according to the present invention is that the energy amount (J) of the laser light applied to the sealing member in the first melting step is the following formula: energy amount (J) = laser Calculated by output (kW) × irradiation time (msec) × (spot diameter of laser beam (μm) / diameter of spherical sealing member (μm)), this amount of energy in the first melting step is calculated as spherical sealing. It is necessary to seal the sealing hole by irradiating the same position on the stop member (sealing member before melting) with laser light having the same output and spot diameter to melt and solidify the whole sealing member ( It is in the point which made it 80% or less of the energy amount (minimum required for this sealing).
The second melting step is performed after sufficient time for cooling and solidification has elapsed after the completion of the first melting step, so that the sealing member that has undergone the first melting step is replaced by the second melting step. The amount of energy required for the main sealing of the sealing hole by melting in the melting step is approximately the same as the amount of energy required for the main sealing by melting the spherical sealing member before melting in a single melting step. It is equivalent.

Next, FIG. 6 is a flowchart illustrating a method for manufacturing an electronic device according to the present invention.
In FIG. 6, the manufacturing process of the container and the piezoelectric vibration element is not shown, and is simplified and shown as a container body preparation process (step S1) and a piezoelectric vibration element preparation process (step S2).
In the container body 3 preparation step shown in step S1, the container body 3 is manufactured and prepared. The container body 3 can be formed by using an insulating material such as ceramic or glass, and more specifically, an aluminum oxide ceramic green sheet can be formed and used. A material such as a ceramic green sheet is formed, two laminated substrates 11 and 12 having concentric through holes 37a and 37b having different diameters are laminated, and a rectangular annular shape is formed on the second laminated substrate 12. The third laminated substrate 13 is laminated and then fired to obtain the outer shape of the container body 3 in which the concave portions having steps are formed.
Each through-hole 37a, 37b may be a circular hole or a non-circular hole.
The outer bottom surface of the first multilayer substrate 11 is formed at a suitable position on the outer surface of the container body 3 made of an insulating material, for example, by performing tungsten metallization, nickel plating and gold plating, and using photolithography together. External mounting terminals (not shown) provided on the electrode layer 15, electrode portions 15 provided on the upper surface of the second laminated substrate 12, and the like are formed. At the same time, a metal film that is compatible with the sealing member is formed on the inner peripheral surface and the outer peripheral edge of the sealing hole 37. In addition, said various terminals provided in the container main body 3 connect corresponding terminals to each other by routing wiring or in-layer wiring such as a through hole formed in advance on each laminated substrate.

In the step of preparing the piezoelectric vibration element shown in step S2, the piezoelectric vibration element 30 is manufactured and prepared. In manufacturing the piezoelectric vibration element 30, first, a large-sized piezoelectric substrate cut out at a predetermined cut angle with respect to the crystal axis, for example, a quartz substrate (quartz wafer) is prepared, and wet etching using photolithography or dry etching is performed. The external shape of the quartz substrate is formed by etching.
Next, electrodes such as excitation electrodes and external connection terminals are formed by sputtering or vapor deposition. The electrode can be formed by forming a chromium layer as a base on the surface of a quartz substrate on which the outer shape of the piezoelectric vibration element is formed, by sputtering or vapor deposition, and laminating a gold layer thereon.
Then, by dicing the wafer on which the plurality of piezoelectric vibration elements 30 are formed, a plurality of pieces of piezoelectric vibration elements are obtained.

Next, the piezoelectric vibration element joining step will be described.
In the piezoelectric vibration element joining step shown in step S3, the piezoelectric vibration element 30 is disposed on the electrode portion 15 provided in the concave portion of the container body 3 by using the conductive adhesive 16 to make electrical and mechanical connection. Join with it.
Specifically, in FIG. 4A, a brazing material 33 such as sealing glass is applied in advance to the upper surface of the outer peripheral wall of the container body 3, and a conductive adhesive 16 is applied on the electrode portion 15 in the recess. The piezoelectric vibration element 30 is placed in a container by placing a portion of an extraction electrode (not shown) provided on the base 31 of the piezoelectric vibration element 30, positioning it with a light load, and curing the conductive adhesive 16. Mount in the body 3.

Next, the frequency adjustment process of the piezoelectric vibration element 30 in step S4 is performed.
In the frequency adjustment step, first, the initial frequency of the piezoelectric vibration element 30 is measured, and the difference between the initial frequency and the target frequency is adjusted to a small allowable range. The frequency adjustment of the piezoelectric vibration element 30 is performed, for example, by irradiating the piezoelectric vibration element 30 with a laser or an ion beam and etching a part thereof by a predetermined amount. The piezoelectric vibration element 30 is known to increase the vibration frequency by reducing the mass of the vibration part. For example, a part of the electrode pattern other than the excitation electrode formed on the piezoelectric vibration element 30 is etched. Thus, the frequency of the piezoelectric vibration element 30 can be adjusted to be high without changing the shape of the excitation electrode. In the case of using the frequency adjusting method based on the mass reduction method, the initial frequency of the piezoelectric vibration element 30 is made to be a lower frequency than the target frequency. Contrary to the mass reduction method described above, frequency adjustment can also be performed by adding mass to the vibrating portion of the piezoelectric vibration element 30 to reduce the frequency (mass addition method). As a method for adding mass, a method of depositing a metal film on the vibration part of the piezoelectric vibration element 30 by sputtering or vapor deposition can be used. When the frequency adjustment is performed by this mass addition method, the initial frequency of the piezoelectric vibration element 30 is made to be higher than the target frequency.

Next, as shown in step S <b> 5, the lid 20 is joined to the open upper end of the outer peripheral wall of the container body 3. The container body 3 and the lid 20 are joined to each other by providing a seal ring as a brazing material made of, for example, a Kovar (Fe—Ni—Co) alloy on the upper end surface of the container body 3. It can be performed by seam welding the lid 20.
Specifically, as shown in FIG. 4B, for example, in a chamber 51 for forming a nitrogen atmosphere, the lid body 20 is placed on a tray 54 on a support base 53, and the above-described lid body 20 is placed thereon. The container body 3 is placed upside down so that the brazing material 33 comes into contact with the lid body 20, and the inside of the chamber 51 is heated while applying a load by the weight 52 from above. Thereby, the lid 20 is joined by melting and hardening the brazing material 33. Note that this step may be performed through the piezoelectric device 1 in a belt furnace in which a nitrogen atmosphere is controlled instead of the chamber 51.
The process of housing the piezoelectric vibration element 30 (electronic component) in the container is completed by steps S3 to S5.

The piezoelectric vibration element 30 joined in the internal space S formed by joining the lid 20 on the container body 3 is moved to the sealing step (S6 to S11) and sealed.
The sealing step is performed, for example, by accommodating the container 2 (container body 3, lid 20) containing the piezoelectric vibration element in a vacuum chamber 51a or the like as shown in FIG. At this time, the container 2 is set upside down so that the sealing hole 37 faces upward.
First, as shown in step S6, a spherical sealing member 38 made of an alloy of gold and germanium, an alloy of gold and tin, or the like is disposed in a sealing hole 37 provided on the bottom surface of the container body 3. To do. The spherical sealing member 38 can be arranged by utilizing the inner peripheral shape of the sealing hole 37. That is, by using the step shape of the sealing hole 37 in which the through hole 37a on the inner space S side and the concentric (outer side) through hole 37b larger than the through hole 37a communicate with each other, the container 2 Is placed so that the inner space S side is on the lower side, so that the spherical sealing member 38 inserted from the outer side of the sealing hole 37 is held by the step portion 40 in the sealing hole 37. (See FIG. 5 (a)).

The process of FIG. 5A will be described in more detail. As shown in FIG. 5C, which is an enlarged view of a part of FIG. 5A, a sealing hole 37 in which a spherical gold germanium alloy (Au / Ge) alloy sealing member 38 is disposed. Is provided with an inner first through-hole 37a having a predetermined inner diameter n1 and an inner diameter n2 larger than the first through-hole 37a, and is open to the outside. Second through hole 37b. The diameter n3 of the spherical gold germanium alloy (Au / Ge) alloy sealing member 38 is larger than the inner diameter n1 of the first through hole 37a and slightly smaller than the inner diameter n2 of the second through hole 37b. ing.
Therefore, the spherical gold germanium alloy sealing member (Au / Ge) 38 is in contact with the ridgeline of the edge e (step 40) of the inner peripheral edge of the first through hole 37a as shown in the drawing. Is held. The spherical gold germanium alloy (Au / Ge) alloy sealing member 38 is irradiated with a laser beam L as shown. Although the melting point of the sealing member 38 of the gold germanium alloy (Au / Ge) alloy is about 360 degrees, the laser beam L has a property that the sealing member 38 of the present embodiment easily absorbs light. Therefore, the spherical gold germanium alloy (Au / Ge) alloy 38 can be appropriately melted by irradiating under substantially the same conditions as in the case of gold tin.

Next, in step S7, a first melting step (temporary fixing step of the sealing member) that characterizes the present invention is performed.
In the first melting step, as shown in FIG. 7A, the central portion C1 of the outer surface of the spherical sealing member 38 is irradiated with laser light to be uniformly heated and melted to be non-spherical. By solidifying after being deformed, the sealing member is fixed to the inner peripheral surface of the sealing hole or its peripheral portion in a state where a gap G for ventilation is formed between the inner peripheral edge of the sealing hole and the sealing member. (Temporarily fixed). Alternatively, as shown in FIG. 8 (a), sealing is performed by irradiating a portion of the outer surface of the spherical sealing member 38 that is deviated from the central portion C1 in plan view and irradiating a part thereof with solidification after melting. A temporarily fixed state is realized in which a melted part of the member is fixed to the inner peripheral surface of the sealing hole 37 or the peripheral portion thereof. In this temporarily fixed state, the sealing member maintains a state where a part thereof is fixed to the sealing hole while maintaining the internal space S and the outside of the container in communication.
This will be described in more detail. FIG. 7B shows the sealing member when the optical axis of the laser beam is made to coincide with the central portion C1 of the outer surface of the sealing member and irradiated toward the center point C2 inside the sphere. FIG. 8B shows the laser light beam with respect to the portion displaced in the outer diameter direction from the center portion C1 of the outer surface of the sealing member as shown in FIG. 8A. A temporarily fixed state of the sealing member is shown in the case where irradiation is performed in a direction in which the center point C2 of the inner surface of the sphere is removed while matching the axes.

In the case of FIG. 7, since the spherical sealing member is uniformly melted as a whole with the center portion C1 as the center, the sealing member is fixed to the periphery of the through-hole 37a while being uniformly deformed into a non-spherical shape. A sufficient gap G is formed between the inner peripheries of the through holes 37a and 37b to discharge the gas in the internal space. At this point, the laser beam irradiation is stopped.
In the case of FIG. 8, since the melting proceeds centering on a portion deviated from the central portion C1 of the spherical sealing member, the sealing member has a portion 38A in which the progress of melting is fast and the progress of the melting is slow (or The portion 38A, which has been melted quickly by being irradiated with laser light, expands in the outer diameter direction and is joined to the inner wall of the second through hole 37b, while being melted. The portion 38B where no progress has been made is pulled by the portion 38A during the cooling of the portion 38A where the melting is progressing, and is lifted from the inner periphery of the sealing hole. Therefore, a gap G sufficient to discharge the gas in the internal space is formed between the portion 38B where the melting has not progressed and the inner periphery of the sealing hole (the portion opposite to the portion irradiated with the laser beam). The At this point, the laser beam irradiation is stopped.

As a result of the sealing member 38 incompletely closing the sealing hole 37 in the first melting step, the gas in the container is efficiently discharged from the gap G between the sealing member and the sealing hole by heating in the subsequent decompression step. While being discharged, the lightweight sealing member does not detach from the periphery of the sealing hole and scatter due to the gas pressure discharged.
The energy amount (J) of the laser beam irradiated to the sealing member in the first melting step is energy amount = laser output (kW) × irradiation time (msec) × (spot diameter of laser beam (μm) / spherical. The diameter (μm) of the sealing member is calculated.
Then, the irradiation energy amount in the first melting step is irradiated to the same position on the spherical sealing member (sealing member before melting) with laser light having the same output and the same spot diameter, and the entire sealing member While maintaining a gap G having a sufficient opening amount that can be used for degassing by making the amount of energy required to completely seal the sealing hole by melting and solidifying It becomes possible to fix the sealing member around the sealing hole at other portions.

The amount of energy for the laser beam to melt the sealing member is (the spot diameter of the laser beam / spherical) with respect to the energy amount (J) obtained by the product of the laser output (kW) and the irradiation time (msec). It is obtained by multiplying by the diameter of the sealing member. For this reason, by selecting these parameters in various ways, the amount of energy is irradiated to the same position on the spherical sealing member with the same output and the same spot diameter to melt and solidify the entire sealing member. By setting the amount of energy required to completely seal the sealing hole to 80% or less, a gap G having a necessary and sufficient opening amount can be formed between the sealing hole and the sealing member.
In the case of FIG. 7, in order to irradiate the central portion of the sealing member with the laser beam, it is necessary to accurately control the energy amount for melting given to the sealing member by the laser beam irradiation, and the energy amount is too small. If it is, it will be in the temporary fixing defect state in which joining is inadequate, and if an energy amount is excessive, it will be in the perfect sealing state in which gap formation is inadequate.
On the other hand, in the case of FIG. 8, the laser beam is irradiated to the part deviated from the central portion of the sealing member, so that the amount of energy for melting given to the sealing member by the irradiation of the laser beam is somewhat 80%. Even if it exceeds the range, there is no significant effect on the formation of a gap due to the floating of the portion 38B where the melting has not progressed. Therefore, even if the control of the energy amount by laser light irradiation is performed with low accuracy, it can be sufficiently temporarily fixed.
Thus, in the temporary fixing step, the amount of energy irradiated from the laser beam can be selected within a wide range, so that it becomes easy to adjust the amount of energy for melting by laser irradiation in temporary fixing, and the productivity is improved. be able to.

FIG. 9 shows the amount of energy (J) required to temporarily fix the sealing member in the first melting step and the energy required to completely seal the sealing hole by melting the sealing member in an unmelted state. The amount (J) is shown, and the experimental results when the irradiation energy amount of the laser beam is varied are shown.
The case of temporarily fixing the sealing member in the first melting step includes both the laser irradiation method shown in FIG. 7 and the laser irradiation method shown in FIG.
The amount of energy that the laser beam gives to the sealing member is determined by the product of the power W of the laser beam and the irradiation time (msec).
In FIG. 9, the main sealing region indicates a range of energy amount when the sealing hole 37 is completely sealed in the first melting step for temporary fixing. For example, when the amount of energy required for temporary fixing is 100% of the amount of energy required for main sealing, the main sealing (NG) is obtained.
The incomplete temporary fixing region is a state in which a sufficient gap G for ventilation cannot be stably secured between the internal space S of the container and the outside of the container in the first melting step for temporary fixing. The range of the energy amount in the case is shown. In an incomplete temporary fixing region, an ideal temporary fixing state may be realized, but there may be a final sealing state in which the sealing hole is completely sealed, and the accuracy of temporary fixing varies. The reliability of the fixed result is lowered. For this reason, the product obtained by temporary fixing using the amount of energy in this range cannot be used for actual use.

  Next, the temporary fixing region refers to the periphery of the sealing hole while ensuring a necessary and sufficient air gap G between the internal space S of the container and the outside of the container in the first melting step for temporary fixing. The range of the energy amount in the case where an ideal temporarily fixed state in which the sealing member 38 is fixed can be realized is shown. For example, when the amount of energy required to fully seal a sealing hole using a sealing member in an unmelted state is 3.2 J, the energy amount irradiated at the time of temporary fixing is limited to 2.56 J An ideal temporarily fixed state could be obtained with a probability of 100%. In this case, the energy amount 2.56 for temporary fixing is 2.56 / 3.2 = about 0.80 with respect to the energy amount 3.2 for main sealing, and remains below 80%. . On the other hand, when the energy amount for temporarily fixing is 2.6 J, the accuracy of the temporarily fixed state is lowered.

Further, when the energy amount for main sealing of the sealing hole is 3.8 J, an ideal temporarily fixed state is obtained with a probability of 100% by keeping the energy amount irradiated at the time of temporary fixing at 3.2 J. I was able to. In this case, the energy amount 3.2J for temporary fixing is 3.2 / 3.8 = about 0.84 with respect to the energy amount 3.8J for main sealing, exceeding 80%. Yes. On the other hand, when the energy amount for temporary fixing was 3.6 J, the accuracy of the temporarily fixed state was lowered.
Further, when the energy amount for main sealing of the sealing hole is 4.4 J, an ideal temporarily fixed state is obtained with a probability of 100% by keeping the energy amount irradiated at the time of temporary fixing at 3.6 J. I was able to. In this case, the energy amount 3.6J for temporary fixing is 3.6 / 4.4 = about 0.82 with respect to the energy amount 4.4J for main sealing, exceeding 80%. Yes. On the other hand, when the energy amount for temporary fixing was 4.0 J, the accuracy of the temporarily fixed state was lowered.

Based on the above experimental results, the probability that an ideal temporarily fixed state is realized is 100% because the energy amount for temporary fixing is 80% or less of the energy amount for main sealing. It can be seen that this is the case.
Next, in the depressurization step of step S8, the internal space S of the container 2 is depressurized by depressurizing the inside of the vacuum chamber, and the gap G between the inner periphery of the sealing hole 37 and the sealing member 38 deformed into a non-spherical shape. Then, the gas inside the container 2 generated by heating is discharged to the outside of the container 2. That is, harmful gas (outgas) generated in the curing process of the conductive adhesive 16 such as silver paste used for bonding the piezoelectric vibration element 30 and the electrode unit 15 described in step S3, or the inside of the container 2 (inside The gas in which the water in the space S) is evaporated is discharged to the outside in this decompression step.
That is, in the decompression process of step S8, as shown in FIG. 10, the container 2 in a state where the sealing member 38 is temporarily fixed in the sealing hole 37 in the first melting process is disposed in the vacuum chamber 51a, The inside of the chamber 51a is evacuated by a vacuum exhaust means (not shown), preferably in a high vacuum state.
At this time, since the sealing member 38 that has undergone the first melting step is securely fixed around the sealing hole while maintaining a gap for ventilation, there is no possibility of the sealing member popping out and falling off during evacuation. It becomes. For this reason, the speed and strength of evacuation can be increased, and productivity can be increased. At the same time, the degree of vacuum in the container can be increased to eliminate variations in the degree of vacuum, so that device characteristics can be improved and characteristic variations can be reduced.

FIG. 11 shows an example of a temperature profile in the decompression step. That is, the inside of the vacuum chamber 51a is set to a high vacuum of about 10 ⁻³ Pa (pascal), for example. Then, during T1 time (for example, 20 minutes), heating is performed to 250 to 300 degrees, preferably 260 degrees or more. This temperature is maintained for T2 hours (for example, 30 minutes), and a gas component generated from, for example, the conductive adhesive 16 in the container 2 is discharged out of the container 2.
Subsequently, the vacuum hole sealing step (second melting step) is performed for T3 time (for example, 20 minutes) while maintaining the temperature and pressure in the vacuum chamber 51a. At this time, the melting temperature of the gold germanium alloy (Au / Ge) sealing member 38 is high even if the ambient temperature is high. And the gas component can be effectively driven out. Then, the laser beam L is irradiated from the laser irradiation means 55 toward the sealing member 38 to melt and solidify the temporarily fixed sealing member 38, thereby completely closing the through hole 37 (S9, S10). )).
Then, the atmosphere is released and the process ends (step S11).

As described above, in the method for manufacturing a piezoelectric device (electronic device) according to the present embodiment, a spherically formed gold germanium alloy (Au / Ge) is sealed with respect to the through-hole 37 formed in the bottom of the container body 3. The stop member 38 is disposed and temporarily fixed (unsealed) by the first melting step, and then the main melting (main sealing) is performed in the second melting step.
For this reason, it can prevent reliably that a sealing member disperses with the gas discharged | emitted from a sealing hole by a simple method, without using the cover board which causes productivity fall.
The sealing member 38 made of a gold germanium alloy (Au / Ge) has a high melting point, but is easily oxidized, and an oxide film is easily formed on the surface. It becomes difficult. However, when a gold germanium alloy (Au / Ge) is formed into a spherical shape and irradiated with laser light, the oxide film easily absorbs light and is easily melted due to the oxide film, and the oxide film faces the outside of the through-hole 37. Extruded. Thereby, the through-hole 37 can be completely closed by appropriately flowing the alloy component of the sealing member 38 into the through-hole 37. For this reason, when heat is applied in the process of mounting the piezoelectric device 1 after sealing, the sealing member 38 of the gold germanium alloy has a high melting point and does not easily melt. Is effectively prevented from leaking due to partial melting of the sealing member. In addition, since the sealing member 38 does not contain lead, environmental pollution caused by lead can be avoided.

FIG. 12A is a schematic plan view showing the configuration of different embodiments of the piezoelectric device of the present invention. In the figure, the piezoelectric device 60 shows an example in which a piezoelectric oscillator is formed by using the piezoelectric vibration element 30, and portions having the same reference numerals as those in the first embodiment have a common configuration. The description will be omitted, and the difference will be mainly described.
FIG. 12B is a schematic cross-sectional view taken along the line XX of FIG. 12A, and the container body 61 has a larger number of ceramic sheets than the container body 3 of the first embodiment during its manufacture. Manufactured using a laminated substrate. Thus, the container body 61 is formed with a recess 62 near the center using the increased number of laminated substrates, and an electrode (not shown) is provided on the inner bottom thereof. An integrated circuit 63 is mounted on this electrode. The integrated circuit 63 constitutes a predetermined frequency dividing circuit and the like, and is electrically connected to the drive electrode of the piezoelectric vibration element 30 so that the drive voltage output from the integrated circuit 63 is applied to the piezoelectric vibration element 30. It has become.
The sealing member 38 filled in the through hole 37 of the container main body 61 is the same as that described in the first embodiment, and is sealed in the same sealing process. Therefore, this embodiment can also exhibit the same operational effects as the first embodiment. As described above, the present invention is not limited to the piezoelectric vibrator, and the piezoelectric vibration element is housed in the container body and sealed by the lid body regardless of the name of the piezoelectric oscillator or the filter as shown in FIG. Applicable to any piezoelectric device of the configuration.

FIG. 13 is a diagram showing a schematic configuration of a digital mobile phone device as an example of an electronic apparatus using the piezoelectric device according to the above-described embodiment of the present invention. In the figure, a microphone 108 for receiving the voice of the sender and a speaker 109 for outputting the received content as a voice output are provided, and further, an integrated circuit or the like as a control unit connected to the modulation / demodulation unit of the transmission / reception signal. The controller 101 is provided. The controller 101 controls an information input / output unit 102 including an LCD as an image display unit and an operation key for inputting information, and an information storage unit 103 including a RAM and a ROM in addition to modulation and demodulation of transmission / reception signals. Is supposed to do. Therefore, the piezoelectric device 1 is attached to the controller 101, and the output frequency is used as a clock signal suitable for the control content by a predetermined frequency dividing circuit (not shown) built in the controller 101. Has been. The piezoelectric device 1 attached to the controller 101 may be a piezoelectric device 60 as shown in FIG. 12 which is an oscillator combining the piezoelectric device 1 and a predetermined frequency dividing circuit, etc. Good.
The controller 101 is further connected to a temperature compensated crystal oscillator (TCXO) 105, and the temperature compensated crystal oscillator 105 is connected to a transmitter 107 and a receiver 106. As a result, even if the basic clock from the controller 101 fluctuates when the environmental temperature changes, it is corrected by the temperature compensated crystal oscillator 105 and supplied to the transmission unit 107 and the reception unit 106.

In this way, by using the piezoelectric device according to the above-described embodiment in an electronic apparatus such as the mobile phone device 110 including the control unit, the piezoelectric vibration element correctly positioned in the container body can be obtained in the manufacturing process. By using the piezoelectric device provided, an accurate clock signal can be generated.
The present invention is not limited to the above-described embodiment. Each configuration of each embodiment can be appropriately combined or omitted, and can be combined with other configurations not shown.

In the above embodiment, the sealing hole is formed on the container body side, but the sealing method according to the present invention can also be applied to an electronic device having a sealing hole on the lid side. In short, the present invention can be applied to general electronic devices having a sealing hole in any part of the outer surface of the container.
Moreover, although the container main body 3 which concerns on the said embodiment was used as the insulated substrate which has a recessed part in the upper surface, it mounts an electronic component on the flat insulating substrate which does not have a recessed part, and the space on the insulated substrate containing an electronic component is made. The sealing method of the present invention can also be applied to an electronic device that is sealed with a bathtub-type (reverse saddle-shaped) lid. In this case, the sealing hole may be provided on the insulating substrate side or may be provided on the lid side.

DESCRIPTION OF SYMBOLS 1 ... Piezoelectric device, 2 ... Container, 3 ... Container main body, 11, 12 ... Laminated substrate, 15 ... Electrode part, 16 ... Conductive adhesive, 20 ... Lid body, 30 ... Piezoelectric vibration element (electronic component), 31 ... Base part 33 ... brazing material 34, 35 ... vibrating arm 37 ... sealing hole 37a, 37b ... through hole 38 ... sealing member 38A ... part where the progress of melting is fast, 38B ... part where the progress of melting is slow , 40 ... Stepped part, 42 ... Recessed part, 51 ... Chamber, 51 a ... Vacuum chamber, 52 ... Weight, 53 ... Support base, 54 ... Tray, 55 ... Laser irradiation means, 60 ... Piezoelectric device, 61 ... Container body, 62 ... Recess, 63 ... Integrated circuit

Claims (3)

A container having a void inside and having a sealing hole for communicating the void with the outside of the container; a sealing member for sealing the sealing hole; and an electronic component accommodated in the container; A method of manufacturing an electronic device comprising:
Accommodating the electronic component in a void of the container;
A sealing member disposing step of disposing at least a part of the sealing member in the sealing hole;
A first melting step for fixing the sealing member to the container in a state in which communication between the void of the container and the outside of the container is ensured;
A decompression step of decompressing a void of the container after the first melting step;
A second melting step of sealing the container by melting the sealing member after the decompression step;
The manufacturing method of the electronic device characterized by the above-mentioned.   Prepare laser beam irradiation means, and irradiate the laser beam so that the optical axis of the laser is displaced from the central portion of the sealing member in plan view toward the outer shape, thereby melting the sealing member The method of manufacturing an electronic device according to claim 1.   The amount of energy of the laser beam applied to the sealing member in the first melting step is 80% of the amount of energy required to melt and solidify the entire sealing member to completely seal the sealing hole. The method of manufacturing an electronic device according to claim 2, wherein:

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