JP2008118241A - Electronic device and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compact and reliable electronic device having superior productivity, and to provide a method for manufacturing the electronic device. <P>SOLUTION: The electronic device has a vibration reed arranged inside a closed space, an IC arranged outside the closed space, and a through electrode connecting the vibration reed and the IC electrically. The closed space is surrounded by a base member, a sidewall member, and a lid. The vibration reed is mounted at one side of the base member and the IC is formed at the other. The base and sidewall members are two divided members and are made of silicon. The lid is made of a metal material. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  More particularly, the present invention relates to a small electronic device having excellent productivity and high reliability, and a method for manufacturing the same.

  In recent years, demand for portable electronic devices typified by mobile phones and wearable devices is increasing. In such portable electronic devices, electronic devices typified by crystal oscillators are often used. In recent years, there has been an increasing demand for small electronic devices that are particularly reliable and excellent in productivity.

  Furthermore, in the automobile field, with the advancement of ITS (Intelligent Transport System), efforts to digitize automobiles and IT (information and communication technology) are becoming active. In such efforts, the importance of acceleration sensors, angular velocity sensors, and the like has further increased, and the demand for electronic devices used for these, particularly small electronic devices that oscillate with high precision, has increased.

  Hereinafter, a known configuration and a manufacturing method of a crystal oscillator using a resonator element (crystal resonator element) made of quartz, which is the most in demand among electronic devices, will be described (for example, see Patent Document 1).

  FIG. 5 is a cross-sectional view of a crystal oscillator which is an example of a conventional electronic device. In the conventional crystal oscillator 20, an integrated circuit element (IC 100) is formed on the lower surface of a package 700 made of silicon (Si), and a cavity (deep portion) 720 is formed on the upper surface of the package 700. The crystal vibrating piece 500 was mounted. Further, the quartz crystal vibrating piece 500 and the IC 100 are electrically connected by the through electrode 600 provided in the package 700.

  Furthermore, the lid 800 was joined to the opening of the cavity 720, and the inside of the cavity 720 was hermetically sealed in a nitrogen atmosphere or a vacuum atmosphere.

  The IC 100 is provided with a feedback amplifier circuit that operates the crystal resonator element 500. However, if necessary, a temperature compensation circuit pattern for reducing a frequency change due to a change in the ambient temperature may be added. Good. Further, a voltage control circuit pattern for changing the output frequency by an external control voltage may be added.

  FIG. 6 is a diagram showing an example of a conventional crystal oscillator manufacturing method. Conventionally, the crystal oscillator 20 has been manufactured by the following manufacturing method. First, a plurality of ICs 100 are simultaneously formed on one plane of a silicon (Si) wafer 750 by a commonly used LSI manufacturing technique. Thereafter, a plurality of cavities 720 for mounting the crystal vibrating piece 500 are formed on the plane of the Si wafer 750 where the IC 100 is not formed by a wet etching method or a dry etching method.

  Further, in order to ensure conduction between the piezoelectric vibrating piece 500 and the IC 100, a through hole is provided from the inner bottom surface of the cavity 720 to the IC 100, and the through electrode 600 is formed inside the through hole. The through electrode 600 can be formed by a sputtering method, a plating method, or the like.

  Thereafter, the quartz crystal vibrating piece 500 manufactured in another process is mounted inside the cavity 720 with a conductive adhesive or the like.

  The lid 800 is mounted on the Si wafer 750 on which the plurality of ICs 100 and the crystal vibrating piece 500 formed as described above are configured. As shown in FIG. 6A, one lid 800 is attached to each cavity 720 formed in a plurality of Si wafers 750. In this case, a metal material such as Kovar or a glass material can be used for the lid 800, and an airtight sealing in the cavity 720 is performed by applying and bonding an adhesive to the entire periphery of the opening periphery of the cavity 720. (FIG. 6B).

  Thereafter, the Si wafer 750 is separated by a dicing method so as to form a package 700 having a predetermined size, and the crystal oscillator 20 is completed (FIG. 6C). At this time, the member to be diced is only the Si wafer 750, and the lid 800 is not diced. Therefore, the lid 800 may be made of any material as described above.

  FIG. 7 is a diagram showing another example of a conventional method for manufacturing a crystal oscillator. As another method for manufacturing the conventional crystal oscillator 20, the following method has also been proposed. The manufacturing process until a plurality of ICs 100 are formed on one Si wafer 750 and connected to the quartz crystal vibrating piece 500 via the through electrode 600 is the same as the manufacturing method described above. The manufacturing method shown in FIG. 7 is different from the manufacturing method shown in FIG. 6 in that a lid plate 820 having the same size as that of the Si wafer 750 is prepared and mounted on the Si wafer 750 as shown in FIG. ing. As a result, the surface side of the Si wafer 750 where the cavity 720 is formed is bonded so as to be entirely covered with the lid plate 820 (FIG. 7B).

  Thereafter, the Si wafer 750 is separated by a dicing process so as to form a package 700 having a predetermined size, and the crystal oscillator 25 hermetically sealed with the lid 805 is completed (FIG. 7C). In the case of the manufacturing method shown in FIG. 7, since the lid plate 820 is diced together with the Si wafer 750, the lid plate 820 also needs to be made of a brittle material such as Si or glass.

JP 2004-214787 A (page 4, FIG. 1)

  In the conventional crystal oscillator 20 manufactured by the manufacturing method of FIG. 6, it is necessary to arrange small pieces of the lids 800 on the cavities 720 of the Si wafer 750 with high accuracy and to individually bond them individually. For this reason, the productivity was very poor, and as a result, the production cost was increased.

  In addition, as the size of the lid 800 is reduced as the size of the lid 800 is reduced, the alignment accuracy between the lid 800 and the cavity 720 becomes stricter. As a result, poor bonding occurs frequently, leading to deterioration of reliability.

  Further, since the bottom surface of the cavity 720 formed by wet etching or dry etching has poor surface accuracy and is not a flat surface, the quartz crystal vibrating piece 500 is tilted and fixed when the quartz crystal vibrating piece 500 is mounted. In the worst case, there are many defects in which the crystal vibrating piece 500 comes into contact with the wall surface of the cavity 720, leading to deterioration in reliability.

  In the conventional crystal oscillator 25 manufactured by the manufacturing method of FIG. 7, since the lid plate 820 is bonded to the Si wafer 750, the alignment with the individual cavities 720 is not necessary, and the productivity is good. Therefore, the lid plate 820 needs to be made of a brittle material such as Si or glass. This is because when a metal material is used for the lid plate 820, the processing conditions differ from those of the Si wafer 750, which is a brittle material, and therefore it cannot be cut simultaneously. Even if it can be cut, the processing conditions optimum for processing differ, so that processing distortion always occurs in either the lid plate 802 or the Si wafer 750. As a result, separation occurs between the lid plate 802 and the Si wafer 750. End up. Moreover, the surface accuracy of the cut surface is very poor, and burrs and cracks are always generated.

  Therefore, in the conventional crystal oscillator 25 shown in FIG. 7, the lid 805 is always made of Si or glass, which is a brittle material. However, when Si or glass is used for the lid 805, the lid 805 is easily broken by minute vibration or external force after being incorporated into a product that is subject to vibration or external force such as car electronics products and portable electronic devices. Was frequent and the reliability was very poor.

  An object of the present invention is to provide a very small electronic device, and further to provide an electronic device having excellent productivity and high reliability. Another object of the present invention is to provide a method for manufacturing a small and highly reliable electronic device with excellent productivity.

  In order to solve the above-described problem, in the electronic device of the present invention, the resonator element disposed inside the sealed space, the IC disposed outside the sealed space, and the electrode that electrically connects the resonator element and the IC. In the electronic device including the closed space, the sealed space is a space surrounded by the bottom, the side wall, and the lid, and the bottom member that constitutes the bottom and the side wall member that constitutes the side wall are two divided members. It is a feature.

  Further, the bottom member is preferably made of silicon.

  Further, the side wall member is preferably made of silicon.

  Furthermore, the lid is preferably made of a metal material.

  Furthermore, it is desirable that the resonator element is made of quartz.

  In the electronic device manufacturing method of the present invention, an electronic device including a vibrating piece disposed inside the sealed space, an IC disposed outside the sealed space, and an electrode that electrically connects the vibrating piece and the IC. In the device manufacturing method, a step of forming an IC on one side of the bottom substrate, a step of forming a hole in the bottom substrate and forming an electrode therein, a step of mounting a resonator element on the other side of the bottom substrate, A step of forming a lid on one side of a side wall substrate, which is a substrate different from the bottom substrate, a step of forming an opening from the other side of the side wall substrate, a surface on one side of the bottom substrate, and a surface on the other side of the side wall substrate And a step of separating the bonded bottom substrate and side wall substrate into the size of the electronic device.

  Further, the bottom substrate is preferably made of silicon.

  Furthermore, the sidewall substrate is preferably made of silicon.

  Furthermore, the lid is preferably made of a metal material.

  Furthermore, it is desirable that the resonator element is made of quartz.

  It is also desirable to form holes in the bottom substrate by etching.

  Furthermore, it is desirable to form a lid by bonding the metal substrate to the sidewall substrate and then processing the metal substrate by an etching method.

  Furthermore, it is desirable to form a lid on the sidewall substrate by a plating method.

  Furthermore, it is desirable to form an opening in the sidewall substrate by an etching method.

  Furthermore, it is desirable to join the bottom substrate and the sidewall substrate by a surface activated bonding method.

(Function)
In the electronic device of the present invention, the resonator element is disposed inside the sealed space surrounded by the bottom, the side wall, and the lid, the IC is disposed outside the sealed space, and the resonator element and the IC are electrically connected by electrodes. is doing. Furthermore, in the present invention, the bottom of the sealed space is formed by the bottom member, and the side wall is formed by the side wall member.

  In the conventional electronic device, the bottom and side walls of the sealed space are formed by a single member called a package having a cavity, but are divided into two members, a bottom member and a side wall member. However, this is the most characteristic feature in the structure of the electronic device of the present invention.

  When the bottom and side walls are formed by cavities formed by a conventional etching method, the bottom surface accuracy is poor. However, when the bottom and side walls are divided as in the present invention, the bottom is obtained by polishing or the like. Since the flat surface of the bottom member is used, the surface accuracy is very good. Therefore, it becomes possible to fix the vibrating piece with high accuracy. As a result, the reliability of the electronic device is improved.

  Note that it is desirable to use silicon (Si) as a material constituting the bottom member. This is because an IC can be directly formed on the plane of the bottom member by a generally performed process.

  Furthermore, it is desirable to use Si similarly as a material constituting the side wall member. This is because, if the side wall member is made of the same material as that of the bottom member, there is affinity, so that the joining is easy and the joining strength is increased.

  Moreover, it is desirable to use a metal material as a material constituting the lid. Electronic devices are often incorporated into car electronics products and portable electronic devices, but these products are strongly demanded for miniaturization and high density, so that electronic devices can be designed to be incorporated in very narrow spaces. Many. In this case, when the electronic device is assembled, it often comes into contact with other parts, and if the thin plate-shaped lid is made of a ceramic material, there is a risk of cracking due to stress or impact at the time of contact.

  In addition, by forming the sealed space with the bottom member, the side wall member, and the lid in this way, it is possible to place the resonator element in a vacuum or low-pressure environment. For example, if a crystal resonator element is used as the resonator element, it can be used as a crystal oscillator with stable vibration characteristics.

Such an electronic device of the present invention in which a sealed space is formed by three members (a bottom member, a side wall member, and a lid) provides the following advantages in the manufacturing process.

  In the manufacturing process, the electronic device of the present invention having a bottom member, a side wall member, and a lid is manufactured by processing and bonding flat plates such as a bottom substrate, a side wall substrate, and a metal substrate. Each of the bottom substrate, the side wall substrate, and the metal substrate has a size corresponding to a plurality of finally completed electronic devices, and a plurality of electronic devices can be obtained from one of these substrates. Yes.

  In each manufacturing process, processing is performed in the substrate state of the bottom substrate, the side wall substrate, and the metal substrate. By processing in the substrate state in this way, a plurality of electronic devices can be processed simultaneously in one process, so productivity is increased. Is very good.

  Further, by using a Si wafer for the bottom substrate, it can be flowed as it is in a normal IC manufacturing process, and an IC can be easily formed on the bottom substrate. Thus, since the IC manufacturing process conventionally used can be used, it is not necessary to start up a new apparatus and manufacturing reliability can be ensured.

  In the electronic device manufacturing method of the present invention, after the metal substrate and the side wall substrate are joined, the metal substrate is processed into a lid by an etching method, and the side wall substrate is processed into a side wall member by etching. The sidewall substrate is made of a material different from that of the metal substrate, preferably an Si wafer, so that the sidewall substrate is not etched when the lid is formed from the metal substrate, and the metal substrate is not etched when the sidewall member is formed from the sidewall substrate. As described above, it is possible to process them separately.

  Accordingly, in addition to the advantage that the lid does not need to be joined alone and the productivity is good, the lid can be formed in a very small shape by an etching method, and therefore, it is suitable for downsizing.

  In the electronic device manufacturing method of the present invention, a lid may be formed on the sidewall substrate by a plating method. Even when the lid is formed by the plating method, a very small lid can be formed by combining with the photolithography method, and the size can be reduced.

  It should be noted that the use of Si wafers for both the bottom substrate and the side wall substrate as described above also has an advantage that bonding is easy because of the mutual affinity. Furthermore, by using a surface activated bonding method suitable for bonding between Si, bonding with extremely high strength becomes possible. As a result, the reliability of the electronic device is improved.

  Further, the surface activated bonding method is one of the few bonding methods that can be bonded at room temperature, and does not affect the IC formed on the bottom substrate thermally. As a result, the reliability of the IC can be maintained.

  According to the present invention, it is possible to provide a very small electronic device, and it is possible to provide an electronic device having high reliability. Further, it is possible to provide a method for manufacturing a small electronic device with excellent productivity.

(First embodiment)
FIG. 1 is a cross-sectional view of a crystal oscillator as an example of an electronic device of the present invention. The crystal oscillator 10 shown as an example of the electronic device of the present invention includes a bottom member 200 made of silicon (Si).
An integrated circuit element (IC100) is formed on the lower surface that is one side of the bottom member 200, and a crystal vibrating piece 500 is mounted on the upper surface that is the other side of the bottom member 200.

  The quartz crystal vibrating piece 500 includes a bottom member 200 made of Si, a side wall member 300 which is a separate member made of Si of the same material as the bottom member 200 and a lid 400 made of Kovar which is a metal material. It arrange | positions in the enclosed sealed space, The sealed space is airtightly sealed in the state of nitrogen atmosphere or a vacuum atmosphere. The crystal vibrating piece 500 in the sealed space and the IC 100 outside the sealed space are electrically connected by a through electrode 600 provided in the bottom member 200.

  In the crystal oscillator 10 of the present invention, the lid 400 is made of a metal material (Kovar). Therefore, there is little risk of breakage and high reliability. This is because electronic devices are often used in car electronics products and portable electronic devices that are highly demanded for miniaturization and high density, and for this reason, electronic devices are often designed to be incorporated in very narrow spaces. In that case, when the electronic device is incorporated, it often comes into contact with other parts, and if the lid 400 is made of a ceramic material, there is a risk of cracking due to stress or impact at the time of contact. This is because it can be avoided.

  The IC 100 is provided with a feedback amplifier circuit that operates the crystal resonator element 500. However, if necessary, a temperature compensation circuit pattern for reducing a frequency change due to a change in the ambient temperature may be added. Good. Further, a voltage control circuit pattern for changing the output frequency by an external control voltage may be added.

  Further, since the IC 100 is connected to another electronic circuit when the crystal oscillator 10 is incorporated in a car electronics product or a portable electronic device, it is desirable that the IC 100 be configured to be easily connected to another electronic circuit. Therefore, if it is easy to connect to other electronic circuits, the IC 100 does not necessarily have to be formed on a plane, and may be formed on the bottom member 200 having a curved surface or a step.

    FIG. 2 is a view showing a method for manufacturing an electronic device of the present invention. First, as shown in FIG. 2A, a side wall substrate 350 made of a Si wafer and a metal substrate 450 made of a Kovar plate are bonded. In this embodiment, a 300 μm thick Si wafer is used as the side wall substrate 350, a 100 μm thick Kovar plate is used as the metal substrate 450, and a bonding agent made of gold / tin alloy (AuSn alloy) is disposed between them. (The bonding portion of the AuSn alloy is not shown in FIG. 2 because it is very thin.)

  In this embodiment, a Kovar plate is used as the metal substrate 450, but is not limited to this material. Use of any metal material such as a stainless steel plate or a nickel (Ni) plate does not hinder the effects of the present invention.

  In this embodiment, the joining method using the AuSu alloy is used for joining, but other joining methods may be used. For example, there is no particular problem even if a surface activated bonding method or an anodic bonding method is used.

  Next, as shown in FIG. 2B, the metal substrate 450 is processed from the Kovar plate by a wet etching method to form a lid 400 having a predetermined size on one plane of the side wall substrate 350. At this point, a plurality of lids 400 are simultaneously formed, and each of them is divided and patterned. However, since it is already bonded to the side wall substrate 350, it does not peel off.

  In addition, it is generally known that the wet etching method is fine and can be processed with high accuracy. By using the wet etching method for forming the lid 400, even the very small lid 400 can be easily formed. Can be formed. As a result, it is also suitable for downsizing electronic devices.

  Further, in the present embodiment, a Si wafer is used for the side wall substrate 350, which is a different material from the metal substrate 450 made of a Kovar plate. Therefore, the side wall substrate 350 made of a Si wafer is not etched when the metal substrate 450 is wet-etched. The material used for the sidewall substrate 350 is not limited in the present invention, but for this reason, it is desirable to select a material different from the metal substrate 450.

  Next, as shown in FIG. 2C, a plurality of crystal resonator pieces 500 having a size that allows the quartz-crystal vibrating piece 500 to enter a position corresponding to the lid 400 on the opposite side of the side wall substrate 350 where the lid 400 is not formed. The opening 320 is formed. The opening 320 is formed using a dry etching method until the sidewall substrate 350 having a thickness of 300 μm penetrates.

  Since the dry etching method in this step is performed under the conditions for processing the sidewall substrate 350 made of Si, the processing stops when the lid 400 made of Kovar appears on the processing surface, and no further processing is performed. . As a result, as shown in FIG. 2C, the sidewall substrate 310 having the opening 320 having the lid 400 formed on one surface is completed.

  Note that a wet etching method may be used as a method of forming the opening 320 in the sidewall substrate 350. In the case of the Si wet etching method, since the processing is performed along the crystal plane, the shape of the opening portion is less flexible, but it is necessary to process the crystal vibrating piece 500 with sufficient size and accuracy. Is possible. Even when the wet etching method is used to form the opening 320, the lid 400, which is a different material, is not etched, and the processing of the opening 320 automatically stops when the lid 400 appears on the processing surface.

  Next, a method for manufacturing the bottom substrate 210 will be described. FIG. 3 is a view showing a process of forming the periphery of the bottom substrate in the method for manufacturing an electronic device of the present invention.

  First, as shown in FIG. 3A, an integrated circuit element (IC 100) is formed on the plane of the bottom substrate 250. As the bottom substrate 250, a Si wafer generally used in an IC manufacturing process is used, and the surface thereof is finished in a state of excellent flatness by polishing. By using this Si wafer, a normal IC manufacturing process can be used as it is, and a plurality of ICs 100 can be simultaneously and easily formed on the bottom substrate 250.

  Thus, since the IC manufacturing process conventionally used can be used, it is not necessary to start up a new apparatus and manufacturing reliability can be ensured. In the present embodiment, a Si wafer having a thickness of 100 μm is used for the bottom substrate 250 in order to reduce the size, particularly the thickness.

  Next, as shown in FIG. 3B, a through hole 220 is opened by a dry etching method from the opposite surface of the bottom substrate 250 where the IC 100 is not formed. The through hole 220 is processed until reaching the IC 100, and the processing is stopped when the IC 100 appears on the surface. As a result, as shown in FIG. 3B, the bottom substrate 210 in which the IC 100 is formed on one surface and the through hole 220 is formed from the other surface side is completed.

Next, as shown in FIG. 3C, the through electrode 600 is formed in the through hole 220 opened in the bottom substrate 210. In the present embodiment, the through electrode 600 made of gold (Au) is formed in the through hole 220 by plating. At this time, the IC 100 and the through electrode 600 are electrically connected.

  Further, as shown in FIG. 3D, the crystal vibrating piece 500 is mounted so as to be electrically connected to the through electrode 600. As a result, the IC 100 and the quartz crystal vibrating piece 500 are electrically connected via the through electrode 600. As described above, the surface of the bottom substrate 210 made of a Si wafer is finished by polishing, and its flatness is very good. Therefore, there is almost no defect that the quartz crystal resonator 500 is tilted and fixed and comes into contact with the bottom substrate 210. In addition, since the crystal vibrating piece 500 can be mounted without a side wall, workability is very good.

  Thereafter, as shown in FIG. 2D, the sidewall substrate 310 in the state of FIG. 2C and the bottom substrate 210 in the state of FIG. Form.

  It is desirable to use a surface activated bonding method for bonding the sidewall substrate 310 and the bottom substrate 210. The surface activated bonding method is one of the few bonding methods that can be bonded at room temperature. Therefore, the IC 100 formed on the bottom substrate 210 is not affected by thermal damage, and the reliability of the IC 100 is not impaired.

  Furthermore, in the present embodiment, the bottom substrate 210 and the side wall substrate 310 are both made of Si and have an advantage of being easy to join because of their affinity. Furthermore, since the surface activated bonding method is a bonding method suitable for bonding between Si, bonding with very high strength is possible. For the above reasons, the reliability of the electronic device can be improved by using the surface activated bonding method.

  It should be noted that the flatness of the surface to which the side wall substrate 310 is bonded and the surface to which the bottom substrate 210 is bonded is preferably good. This is because in the surface activated bonding method, the better the flatness of the bonding surface, the higher the bonding strength and the higher the bonding reliability.

  Note that by performing bonding in a nitrogen atmosphere or a vacuum atmosphere, the sealed space surrounded by the bottom substrate 210, the sidewall substrate 310, and the lid 400 can be hermetically sealed in a nitrogen atmosphere or a vacuum atmosphere. It is. In general, the crystal oscillator 10 can vibrate stably by arranging the crystal vibrating piece 500 in such a nitrogen atmosphere or a vacuum atmosphere to vibrate.

  Finally, the bonded bottom substrate 210 and side wall substrate 310 are divided by a dicing method, a laser processing method, or the like to mass-produce the crystal oscillator 10 whose outer shape is configured by the bottom member 200, the side wall member 300, and the lid 400. (Fig. 2 (e)).

  In the present embodiment, both the bottom substrate 210 and the side wall substrate 310 are made of Si, and are made of the same material. Therefore, even if dicing is performed, the substrate can be processed in the same manner under the same conditions. For this reason, excessive processing distortion is not caused during processing, and separation between the bottom substrate 210 and the side wall substrate 310 does not occur. The machined surface could also be finished to a clean surface with excellent flatness.

  As described above, in the method of manufacturing an electronic device according to the present invention, the manufacturing proceeds in a substrate state (a state of a bottom substrate and a side wall substrate) in which a plurality of electronic device components are arranged, and finally divided into individual electronic devices. To completion. Therefore, the parts constituting the electronic device are not handled one by one in small pieces, and the productivity is very good.

  Even if the electronic device is downsized, the size of the electronic device is not changed, and the size of the substrate can be handled in the same manner as before, so that there is almost no deterioration in productivity due to the downsizing effect. On the contrary, when the electronic device is miniaturized, the number of substrates per substrate increases, which leads to improvement in productivity. As described above, the method for manufacturing an electronic device of the present invention is effective for both reducing the size of the electronic device and improving productivity.

  In the present embodiment, as an example of the electronic device, the crystal oscillator 10 using the crystal resonator element has been described as an example. However, the present invention is not limited to the crystal oscillator 10. For example, the effect of the present invention can be sufficiently obtained even in an electronic device using a piezoelectric vibrating piece using a piezoelectric material other than quartz. Also, the application is not limited to the oscillator, and the present invention can be used for sensors such as an acceleration sensor and a gyroscope.

(Second Embodiment)
Another embodiment of a crystal oscillator which is an example of the electronic device of the present invention will be described below. The basic structure of this embodiment is almost the same as that of the above-described embodiment shown in FIG. Also in this embodiment, in the crystal oscillator 10, the IC 100 is formed on the lower surface of the bottom member 200 made of silicon (Si), and the crystal vibrating piece 500 is mounted on the upper surface of the bottom member 200.

  The quartz crystal vibrating piece 500 is disposed in a sealed space surrounded by a bottom member 200 made of Si, a side wall member 300 made of Si, and a lid 400 made of a metal material, and the sealed space is in a nitrogen atmosphere or a vacuum atmosphere. Hermetically sealed. Further, the quartz crystal vibrating piece 500 in the sealed space and the IC 100 outside the sealed space are electrically connected by the through electrode 600 provided in the bottom member 200.

    FIG. 4 is a view showing a step of forming the peripheral portion of the side wall substrate in another method for manufacturing an electronic device of the present invention. In the present embodiment, the formation process of the lid 400 is different from the above-described embodiment. In the present embodiment, the following steps are performed in forming the lid 400 and the side wall substrate 310.

  First, as shown in FIG. 4A, a metal film 475 is formed on one plane of a side wall substrate 350 made of a Si wafer. In this embodiment, an Si wafer having a thickness of 300 μm is used as the sidewall substrate 350, a gold (Au) film having an upper layer of 0.2 μm as the metal film 475, and a lower layer having a thickness of 0.05 μm are formed on the sidewall substrate 350. A laminated film made of a chromium (Cr) film was formed by sputtering (in FIG. 4, the boundary between the Au film and the Cr film is not drawn because it is not directly related to the present invention).

  Note that the metal film 475 is not particularly limited as long as it has conductivity, and is not limited to Au or Cr.

  Next, as shown in FIG. 4B, a resist pattern 900 is formed on the metal film 475 by photolithography. The photolithography method is one of patterning methods widely used in the LSI field, and is a method of forming a resist pattern 900 by exposing and developing a resist made of a photosensitive material. If this method is used, a fine resist pattern 900 at a micron level can be formed, which is suitable for downsizing.

Next, as shown in FIG. 4C, a current is passed through a metal film 475 having a laminated structure of an Au film and a Cr film, and a lid 400 is formed on the metal film 475 by electroplating. The electroplating method does not grow on the resist pattern 900, which is an insulating material, because the plating grows only on the portion where current flows. Therefore, the lid 400 is formed in the inverted shape of the resist pattern 900. In the present embodiment, the lid 400 is made of Ni.
A lid 400 made of Ni was formed with a thickness of 80 μm by plating.

  In the present embodiment, the lid 400 is formed by the Ni plating method, but is not limited to Ni. Any material that can be plated can be used.

  Further, as shown in FIG. 4D, the resist pattern 900 is removed with a stripping solution or an organic solvent, and the metal film 475 under the resist pattern 900 is further removed by an etching method, an ion milling method, or the like. A plurality of patterned lids 400 and metal films 470 are formed on 350.

  After that, as shown in FIG. 4E, the crystal resonator element 500 is large enough to enter the position corresponding to the lid 400 on the opposite side plane where the lid 400 and the metal film 470 of the sidewall substrate 350 are not formed. A plurality of openings 320 are formed. The opening 320 is formed using a dry etching method until the sidewall substrate 350 having a thickness of 300 μm penetrates. Since the dry etching method in this step is performed under the conditions for processing the sidewall substrate 350 made of Si, no further processing is performed when the metal film 470 made of Au or Cr appears on the processed surface. As a result, as shown in FIG. 4C, the sidewall substrate 310 having the opening 320 in which the lid 400 and the metal film 470 are formed on one surface is completed.

  Thereafter, the bottom substrate 210 having the IC 100, the crystal vibrating piece 500, and the through electrode 600 is formed by the method shown in FIG. 3, and the bottom substrate 210 and the sidewall substrate 310 shown in FIG. Also in this embodiment, the surface activated bonding method is used for bonding.

  Finally, the bonded bottom substrate 210 and sidewall substrate 310 are divided by a dicing method, a laser processing method, or the like, and the crystal oscillator 10 whose outer shape is configured by the bottom member 200, the sidewall member 300, and the lid 400 is completed.

  Even in the present embodiment in which the lid 400 is formed by a plating method, the components constituting the electronic device are not handled one by one in the manufacturing process, and the manufacturing is performed in the substrate state, so that the productivity is very good. It is.

It is sectional drawing of the crystal oscillator which is an example of the electronic device of this invention. It is the figure which showed the manufacturing method of the electronic device of this invention. It is the figure which showed the formation process of the base part periphery part in the manufacturing method of the electronic device of this invention. It is the figure which showed the formation process of the side wall board | substrate peripheral part in the manufacturing method of another electronic device of this invention. It is sectional drawing of the crystal oscillator which is an example of the conventional electronic device. It is the figure which showed an example of the manufacturing method of the conventional crystal oscillator. It is the figure which showed another example of the manufacturing method of the conventional crystal oscillator.

Explanation of symbols

10, 20, 25 Crystal oscillator 100 IC
200 Bottom member 210, 250 Bottom substrate 220 Through hole 300 Side wall member 310, 350 Side wall substrate 320 Opening 400 Lid 450 Metal substrate 470, 475 Metal film
500 Crystal vibrating piece 600 Through electrode 700 Package 720 Cavity 750 Si wafer 800, 805 Lid 820 Lid plate 900 Resist pattern

Claims (15)

In an electronic device comprising a resonator element disposed inside a sealed space, an IC disposed outside the sealed space, and an electrode for electrically connecting the resonator element and the IC,
The sealed space is a space surrounded by a bottom, a side wall, and a lid, and the bottom member that constitutes the bottom and the side wall member that constitutes the side wall are two divided members. device. The electronic device according to claim 1, wherein the bottom member is made of silicon. The electronic device according to claim 1, wherein the side wall member is made of silicon. The electronic device according to any one of claims 1 to 3, wherein the lid is made of a metal material. The electronic device according to claim 1, wherein the vibrating piece is made of quartz. In a method of manufacturing an electronic device including a resonator element disposed inside a sealed space, an IC disposed outside the sealed space, and an electrode that electrically connects the resonator element and the IC,
Forming the IC on one side of the bottom substrate;
Forming a hole in the bottom substrate and forming the electrode therein;
Mounting a resonator element on the other side of the bottom substrate;
Forming a lid on one side of a side wall substrate that is a substrate different from the bottom substrate;
Forming an opening from the other side of the sidewall substrate;
Bonding the surface on the one side of the bottom substrate and the surface on the other side of the sidewall substrate;
A method of manufacturing an electronic device, comprising the step of separating the bonded bottom substrate and side wall substrate into the size of the electronic device. The method of manufacturing an electronic device according to claim 6, wherein the bottom substrate is made of silicon. The method for manufacturing an electronic device according to claim 6, wherein the sidewall substrate is made of silicon. The method for manufacturing an electronic device according to claim 6, wherein the lid is made of a metal material. The method of manufacturing an electronic device according to claim 6, wherein the vibrating piece is made of quartz. The method for manufacturing an electronic device according to claim 6, wherein holes are formed in the bottom substrate by an etching method. 12. The method of manufacturing an electronic device according to claim 6, wherein a lid is formed by bonding a metal substrate to the sidewall substrate and then processing the metal substrate by an etching method. . The method for manufacturing an electronic device according to claim 6, wherein a lid is formed on the side wall substrate by a plating method. The method for manufacturing an electronic device according to any one of claims 6 to 13, wherein an opening is formed in the sidewall substrate by an etching method. The method for manufacturing an electronic device according to claim 6, wherein the bottom substrate and the side wall substrate are bonded by a surface activation bonding method.

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