JP2010251548A - Electronic device, and electric apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To keep vacuum pressure in a package up to the end of life of a product without being lowered. <P>SOLUTION: This electronic device includes: a stem 10 as a base case provided with an element; a cap 20 as a metallic upper case jointed to the stem 10 in a state covered with the stem 10; a sealing hole 18 for evacuating the inside of a chamber formed with the stem 10 and the cap 20; and a sealing pin 30 as a sealing body having a getter material in a part inserted in the chamber from the sealing hole 18 for sealing the sealing hole 18 after the inside of the chamber is evacuated. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an electronic device that requires vacuum sealing, such as an infrared sensor, an acceleration sensor, a gyroscope, and a resonator, and an electric apparatus configured using the electronic device.

  Conventionally, as an electronic device as described above, a pyroelectric sensor for detecting the movement of a human body is provided in a package called a metal can package, and an inert gas such as nitrogen is present inside the package. What is enclosed is known. However, in a device having an infrared detection element inside a package, it is very important that the inside of the package is a vacuum because the characteristics of the element depend on the atmosphere of the enclosed space.

  In the pyroelectric infrared sensor described above, the package is composed of a metal cap and stem, and a window (generally made of silicon) for transmitting infrared rays having a wavelength of 5 to 12 μm is attached to the cap. ing. Most pyroelectric infrared sensors have a □ -shaped silicon window, and are fixed with an adhesive or low-melting glass.

  When the inside of the package is sealed with an inert gas at a pressure almost equal to the atmospheric pressure, the contact area between the package interior and the outside world (cap and stem weld, cap and silicon window joint) However, when the inside of the package is evacuated, the structure of the contact portion between the inside of the package and the outside requires a structure that maintains airtightness. For example, in an infrared sensor using a □ -type silicon window, if the inside of the package is a vacuum, it is difficult to apply stress due to atmospheric pressure to the joint between the cap and the silicon window, or the window is attached to the inside of the cap. Therefore, it is expected that impure gas will flow into the package.

  In addition, when the silicon window is fixed with an adhesive, it is also conceivable that the vacuum pressure inside the package is significantly reduced immediately after sealing due to the release of gas centered on moisture from the adhesive. In particular, in a package including an element that is preferably operated in a vacuum, the sensitivity is significantly lowered due to a reliability defect of the sealing portion and gas emission. For example, when the sensitivity characteristics are evaluated among elements operating in a vacuum, as shown in FIG. 1, when the vacuum pressure exceeds 100 Pa, the sensitivity is significantly reduced. There are many things that cannot perform as desired.

  In order to obtain desired characteristics, the vacuum pressure inside the package is desirably maintained at 100 Pa or less, and it is required to reach the product life without significantly deteriorating the element characteristics. Therefore, a solid-state imaging device is known in which a casing corresponding to a stem and a lid corresponding to a cap are joined with a first sealing material, the inside of the package is vacuumed, and the sealing hole is melted and sealed with a metal ball. (Patent Document 1).

  However, even in this configuration, when the cap and the stem constituting the package are joined, if there is a plating layer on the inner wall of the package, there is a risk that gas will be released from the plating layer at the time of joining. There is a concern that the vacuum pressure decreases due to the gas release from the gas.

  The present invention has been made in view of the current state of electronic devices that require the inside of a package to be evacuated, and its purpose is to maintain the desired vacuum pressure inside the package while maintaining the characteristics of the device. It is an object of the present invention to provide an electronic device that can be maintained for the lifetime of a product without significantly deteriorating. Moreover, an object of this invention is to provide the electric equipment comprised using the said electronic device.

  An electronic device according to the present invention includes: a base case provided with an element; a metal upper case joined to the base case in a state of being covered with the base case; and a vacuum formed in a chamber formed by the base case and the upper case And a sealing body for sealing the sealing hole after the chamber is evacuated, having a getter material at a portion inserted into the chamber from the sealing hole. It is characterized by.

  Examples of the electronic device include an infrared sensor, an acceleration sensor, a gyroscope, and a resonator. The element refers to a sensor portion of the electronic device. The metal upper case is made of a metal such as iron (especially SPC) or Kovar. The sealing hole is provided in at least one of the base case and the upper case. A vacuum generally refers to 100 pa or less. As the getter material, Zr, V, Fe, or an alloy containing any of these can be used. It is preferable that the getter material is activated by a predetermined means after the chamber formed by the base case and the upper case is evacuated and exhibits a gas adsorption effect.

  In the electronic device according to the present invention, the indoor-side surfaces of the base case and the upper case are non-plated surfaces.

  The electronic device according to the present invention is characterized in that a getter material is provided on at least one of the indoor side surface of the base case and the indoor side surface of the upper case.

  It is preferable that the getter material is activated by a predetermined means after the chamber formed by the base case and the upper case is evacuated and exhibits a gas adsorption effect.

  An electrical device according to the present invention includes the electronic device according to any one of claims 1 to 3; and an electronic element that includes the electronic device and forms an electronic circuit.

  According to the electronic device of the present invention, since the getter material is provided at a portion inserted into the room through the sealing hole of the sealing body, the getter material of the sealing body is placed in the room after the room is evacuated. The gas released from the wall or the like is adsorbed, and the vacuum pressure inside the package remains as desired, and the device characteristics are not significantly deteriorated and the product life is maintained.

  According to the electronic device of the present invention, since the indoor side surfaces of the base case and the upper case are non-plated surfaces, the gas of the plating material is not released from the indoor wall, and the inside of the package Contributes to maintaining the vacuum pressure.

  According to the electronic device of the present invention, since the getter material is provided on at least one of the indoor side surface of the base case and the indoor side surface of the upper case, the getter material adsorbs gas in the room. This contributes to maintaining the vacuum pressure inside the package.

  According to the electric apparatus according to the present invention, since the characteristics of the element in the electronic device are not significantly deteriorated and are maintained until the product lifetime, the lifetime of the electric apparatus can be stabilized.

The figure which shows the relationship between the pressure of the temperature sensing part in the package in an infrared sensor, and a relative response output. FIG. 2 is an assembled cross-sectional view showing the configuration of the infrared light receiving device according to the first embodiment of the present invention. 1 is a plan view of an infrared light receiving device according to a first embodiment of the present invention. FIG. 4 is an AA cross-sectional view of the infrared light receiving device of FIG. 3. Sectional drawing of the infrared rays light receiving device which concerns on the 2nd Embodiment of this invention. The perspective view of the electric equipment comprised using the infrared rays light receiving device which concerns on embodiment of this invention. The circuit block diagram of the electric equipment comprised using the infrared rays light receiving device which concerns on embodiment of this invention.

  Embodiments of an electronic device according to the present invention will be described below with reference to the accompanying drawings. In each figure, the same components are denoted by the same reference numerals, and redundant description is omitted. The electronic device of the present embodiment is an infrared light receiving device, and as shown in FIGS. 2 to 4, a stem 10 that is a base case and a metal that is joined to the stem 10 while being covered with the stem 10. The upper case cap 20 is a main component.

  The cap 20 has a cylindrical shape and has an opening 21 at the head. A step portion is formed on the surface of the cap 20 outside the opening 21, and a Si window 22 that allows infrared rays in a wavelength region of 5 to 12 μm to pass therethrough is fitted and joined. A low melting point glass 23 is attached to the step portion on the surface of the cap 20, and the Si window 22 and the step portion on the surface of the cap 20 are joined by the low melting point glass 23.

  The cap 20 is subjected to metal plating with Ni, for example, before the Si window 22 is fitted. In this case, the inner wall surface 24 of the package constituted by the stem 10 and the cap 20 is masked to be a non-plated surface that is not subjected to metal plating. On the other hand, the surface outside the package that is in contact with the outside air is a metal plating surface 25.

  The stem 10 includes, for example, a disk-shaped base 11 made of the same metal as the cap 20 and terminal pins 12 penetrating the base 11 while being insulated from the base 11. In this case, the operation of the device can be stabilized by connecting one terminal pin 12 to the base 11 and using it as the GND (ground). A light receiving element 13 joined to the base 11 by an Au—Sn solder 14 is provided at substantially the center of the surface of the base 11 facing the cap 20.

  The element electrode of the light receiving element 13 and the terminal pin 12 are bonded by an Au wire 15. Before the light receiving element 13 is provided, for example, metal plating with Ni is performed. In this case, the inner wall surface 16 of the package constituted by the stem 10 and the cap 20 is masked to form a non-plated surface that is not subjected to metal plating. On the other hand, the surface which becomes the outside of the package and comes into contact with the outside air is the metal plating surface 17. Further, a wire bonding plating layer 12a is plated on the tip of the terminal pin 12 in the package.

  A sealing hole 18 is formed in the base 11 so as to communicate with the interior of the package formed by the stem 10 and the cap 20. A sealing pin 30, which is a sealing body for sealing the sealing hole 18 after the package chamber is evacuated, is inserted into the sealing hole 18. As shown in FIG. Then, the sealing hole 18 is soldered and sealed.

  The sealing pin 30 has a getter material at a portion 32 inserted from the sealing hole 18 into the package chamber. As the getter material, Zr, V, Fe, or an alloy containing any of these is employed. In order for the sealing pin 30 to have a getter material, the sealing pin 30 is made of Fe, and Zr and V are vacuum-deposited thereon.

  The process of creating the infrared light receiving device having the above configuration is as follows. Masking is performed on required portions of the stem 10 and the cap 20 and the above-described plating process is performed. The Si window 22 is joined to the opening 21 on the front surface side of the cap 20 using the low melting point glass 23. The light receiving element 13 is bonded to the base 11, and wire bonding with the Au wire 15 is performed.

  About the stem 10 and the cap 20 processed as described above, the corresponding portions of the flange portion 26 of the cap 20 and the stem 10 are resistance-welded. By this welding, the inside of the package formed by the stem 10 and the cap 20 is made a vacuum atmosphere controlled to, for example, 1.0 × 10 −3 Pa or less through the sealing hole 18. In this state, the sealing pin 30 is inserted into the package chamber from the sealing hole 18, and the portion 32 having the getter material is heated by applying heat from the outside of the chamber or by laser irradiation (for example, The getter is activated by heating at 300 to 350 ° C. for 1 hour. As a result, the getter has the effect of absorbing the gas, and the degree of vacuum can be improved.

  Next, molten solder 31 is dropped into the sealing hole 18 to solder the sealing hole 18 portion (or the stem 10 and the sealing pin 30 are welded by laser irradiation), and the stem 10 and the cap 20. The inside of the package constituted by is sealed in a vacuum state. As described above, resistance welding is performed on the corresponding portion of the flange portion 26 of the cap 20 and the stem 10, and after the package chamber is configured by the stem 10 and the cap 20, the package chamber is evacuated, thereby resistance welding. The gas generated from this part can be eliminated in the process of making a vacuum.

  According to the infrared light receiving device configured as described above, since the sealing pin 30 has the getter material at the portion 32 inserted from the sealing hole 18 into the package chamber, the stem 10 and the cap 20 The getter material adsorbs the gas released into the chamber of the package to be configured, and the vacuum pressure is maintained. Further, the inner wall surface 16 of the package constituted by the stem 10 and the cap 20 is masked to be a non-plated surface that is not subjected to metal plating. Is almost eliminated, and the vacuum pressure inside the package can be maintained.

  FIG. 5 shows an infrared light receiving device as an electronic device according to the second embodiment. In this infrared light receiving device, getter materials 27 and 19 are provided on the wall surface 24 and the wall surface 16 of the interior of the package constituted by the stem 10 and the cap 20. In addition, a getter material 12b is provided in a portion of the terminal pin 12 that has entered the interior of the package constituted by the stem 10 and the cap 20 and does not have the wire bonding plating layer 12a. As described above, after the interior of the package is in a vacuum atmosphere, the getter materials 27, 19, and 12b are heated by, for example, laser irradiation to activate the getter.

  Other configurations are the same as those of the infrared light receiving device according to the first embodiment. According to the above configuration, the getter materials 27, 19, 12 b absorb the gas released into the package chamber constituted by the stem 10 and the cap 20, and the vacuum pressure can be maintained.

  In FIG. 6, the lighting fixture as an electric equipment comprised using the infrared rays light receiving device 2 which concerns on the said 1st or 2nd embodiment is shown. The lighting fixture 4 is directly attached to a ceiling or the like, and lamp sockets 42 are provided at both ends of a substantially frame-like fixture body 43. A straight tube fluorescent lamp 41 as a discharge lamp is mounted on the lamp socket 42. In addition, a reflection plate 40 having a substantially dish-shaped cross section is attached to the instrument body 43 so as to face the fluorescent lamp 41, and the surface of the reflection plate 40 is a reflection surface 40a.

  The appliance main body 43 includes the discharge lamp lighting device 1 inside the reflector plate 40. A substrate 5 on which the human detection circuit 50 shown in FIG. 7 is mounted is provided inside one end of the reflector 40, and the infrared light receiving device 2 is mounted on the substrate 5, and the Si window 22 of the infrared light receiving device 2. Is exposed through the hole of the reflector 40. The discharge lamp lighting device 1 and the substrate 5 are connected by a signal line 6.

  The circuit configuration of the fluorescent lamp 41, the discharge lamp lighting device 1, and the human detection circuit 50 of the substrate 5 is as shown in FIG. 7, and the human detection circuit 50 includes the infrared light receiving device 2 and constitutes an electronic circuit. Is provided. The human detection circuit 50 in this example includes an electronic element that amplifies the output of the infrared light receiving device 2 and an electronic element that constitutes a comparator that compares the amplified signal with a predetermined threshold and sends a detection signal to the signal line 6. .

  The discharge lamp lighting device 1 that receives the detection signal via the signal line 6 lights the fluorescent lamp 41 if the detection signal is at a level indicating the presence of a person, and fluoresces if the detection signal is at a level that does not indicate the presence of a person. The lamp 41 is turned off. In the electric appliance, the infrared light receiving device 2 can be used stably until the product life since the device characteristics are maintained until the product life without significantly deteriorating the element characteristics.

DESCRIPTION OF SYMBOLS 10 Stem 11 Base 12b Getter material 13 Light receiving element 20 Cap 21 Opening 22 Si window 27 Getter material 30 Sealing pin 41 Fluorescent lamp 43 Instrument body 50 Human detection circuit

JP 2008-108808 A

Claims (4)

A base case in which the element is provided;
A metal upper case joined to the base case while being covered with the base case;
A sealing hole for evacuating the chamber formed by the base case and the upper case;
An electronic device comprising: a getter material at a portion inserted into a room through a sealing hole; and a sealing body for sealing the sealing hole after the chamber is evacuated.   The electronic device according to claim 1, wherein the indoor-side surfaces of the base case and the upper case are non-plated surfaces.   2. The electronic device according to claim 1, wherein a getter material is provided on at least one of the indoor-side surface of the base case and the indoor-side surface of the upper case. An electronic device according to any one of claims 1 to 3;
An electronic device comprising: an electronic element including the electronic device and constituting an electronic circuit.

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