JP2010096505A - Fine atmospheric pressure sensor and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fine atmospheric pressure sensor having a structure leading to automatization of a production line in a mounting process to a product of the fine atmospheric pressure sensor or to improvement of productivity, simplifying a process in a fine atmospheric pressure sensor manufacturing process, and having high production efficiency. <P>SOLUTION: A process such as hand soldering or solder dipping becomes unnecessary, which has been necessary in a lead type sensor mounting process in the prior art, when mounting the fine atmospheric pressure sensor on a product substrate, by enabling surface mounting of a package of the fine atmospheric pressure sensor, and accordingly the mounting becomes possible by surface mounting, to thereby lead to automatization of the production line or improvement of productivity. Also, the fine atmospheric pressure sensor can be provided, which has a simplified process and high production efficiency in the fine atmospheric pressure sensor manufacturing process by installing a lid material on the package mountable on the surface of the fine atmospheric pressure sensor by press-fitting of a resin lid material, caulking of a metal or molding of a resin. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a micro atmospheric pressure sensor and a method for manufacturing the micro atmospheric pressure sensor.

As a conventional sensor for detecting a minute change in atmospheric pressure, as shown in FIG. 4, a sensing element is provided in a lead type sensor package in which a metal CAN 14 and STEM 15 having vent holes are sealed by resistance welding, and the sensing element Has proposed a wind pressure displacement sensor containing a signal processing unit.
JP 62-38367 A

  However, since the micro pressure sensor composed of the conventional CAN and STEM as described above is a lead type component, it is necessary to deal with manual soldering or solder dip mounting when mounting the micro pressure sensor on the product substrate. . In recent years, most mounting components have been surface-mounted, and the ratio of lead-type components has decreased. For this reason, lead-type component mounting requires the addition of a dedicated process in addition to the normal surface mounting process, which is a bottleneck in automation of the production line and productivity improvement.

  The present invention has been made to solve the above-described problems. In order to economically manufacture a microbarometric sensor excellent in economic efficiency and a microbarometric sensor that does not require a complicated mounting process, Simplify the surface mounting of the pressure sensor package and the sensor package manufacturing method.

  The present invention makes it possible to mount a micro-pressure sensor package on a surface, and when mounting a micro-pressure sensor on a product board, a process such as manual soldering or solder dipping, which is necessary in the conventional lead type sensor mounting process, is performed. By eliminating the need for surface mounting, it is possible to automate production lines and improve productivity. In addition, the installation of the lid material on the surface mountable package of the micro-pressure sensor is made by press-fitting the resin lid material, caulking the metal, or molding the resin molding technology. It is possible to provide a micro-pressure sensor that is simplified and has high production efficiency.

  The best mode for carrying out the present invention (hereinafter referred to as an embodiment) will be described in detail with reference to the drawings as appropriate.

FIG. 1 is a sectional structural view according to Example 1 of the present invention.
In FIG. 1, reference numeral 1 denotes a ceramic package having a box shape corresponding to surface mounting, and has an external connection terminal 2 (external connection terminal) that is electrically connected to an internal wiring pattern at a predetermined position below the package.

Reference numeral 3 denotes a pyroelectric element, which is lead zirconate titanate (PZT) or barium titanate (BaTiO ₂ ), and NiCr, Ag, etc. are vapor-deposited on both surfaces to form electrodes for signal extraction. In addition to the above, the pyroelectric element may be other pyroelectric elements such as LiTiO ₃ .
Reference numeral 4 denotes a support base. As shown in FIG. 1, the support base 4 is also a rectangular parallelepiped having two height planes, with the center portion of the support base being low and both ends having high height planes. The ceramic package 1 is adhered and installed on the inner bottom surface with an adhesive or the like. A conductive adhesive is applied to both ends of the support 4 to fix the pyroelectric element 3. This shape is made to ensure thermal insulation of the pyroelectric element. The support 4 is made of alumina or glass epoxy. The height of the support 4 needs to be adjusted so that the pyroelectric element 3 is lower than the outer wall of the ceramic package 1 when the pyroelectric element 3 is fixed. The support base 4 is wired so that the electric charge taken out from the pyroelectric element 3 can be taken out to the outside, and has an electrode that enables wire bonding.
Reference numeral 5 denotes a surface-mount type field effect transistor (FET) having an electrode capable of wire bonding. The FET 5 is adhered and installed on the inner bottom surface of the ceramic package with an adhesive.

The sensor signal output is connected by bonding the wiring pattern inside the support base 4, FET 5, and ceramic package 1 with an Au wire to form an internal wiring. Further, Rg (not shown) is mounted as necessary to form internal wiring.
Reference numeral 6 denotes a resin lid member having a vent hole 7 for taking in an air flow resulting from an external pressure change into the package. In FIG. 1, the vent hole 7 is at the center of the lid member 6, but it does not necessarily have to be at the center of the lid member 6, and it is sufficient if the air flow resulting from an external pressure change can be taken into the package. The size of the vent is preferably about 1 mm. Further, in the case of a sensor package having a vent hole, since it is not necessary to hermetically seal the inside of the sensor package, the lid member 6 does not need to be resistance welded or soldered to the ceramic package 1, and the lid member 6 is not a ceramic package. It is installed by press-fitting into 1. At this time, the lid member 6 must be press-fitted and attached so that air does not leak from other than the vent hole 7.

The signal processing unit including the pyroelectric element 3, the support 4, and the FET 5 is coated with a resin protective film 8. The resin protective film 8 is produced by processing a coating or a solution in which a diluted film constituent material is dissolved by a dipping (DIPPING) method. The application of the resin protective film 8 has a function of protecting the sensor from the influence of outside humidity and gas. At the same time, it has the combined effect of the function of optimizing the sensitivity as a sensor by controlling the thickness of the resin protective film 8.
As the resin used for the protective resin film, a fluorine polymer, a polyolefin polymer, a paraxylene polymer, or the like is used.

FIG. 2 is a sectional structural view according to Embodiment 2 of the present invention.
In FIG. 2, a ceramic package 1 having a box shape corresponding to surface mounting, a pyroelectric element 3, a support base 4, an FET 5, and a resin protective film 8 are configured and arranged in the same manner as in the first embodiment.

  Reference numeral 9 denotes a metal lid member having a vent hole 10 for taking in an air flow resulting from an external pressure change into the package. In FIG. 2, the vent is at the center of the lid member 9, but it is not necessarily at the center of the lid member 9, and it is sufficient if the air flow resulting from the change in the external atmospheric pressure can be taken into the package. The size of the vent is preferably about 1 mm. Further, in the case of a sensor package having a vent hole, since the inside of the sensor package does not need to be hermetically sealed, the lid member 8 is installed by being crimped to the ceramic package 1. At this time, it must be crimped so that air does not leak from other than the vent hole 10.

FIG. 3 is a sectional structural view according to Embodiment 3 of the present invention.
In FIG. 3, 11 is a metallic lead frame having a shape corresponding to surface mounting.
Reference numeral 3 denotes a pyroelectric element, which is lead zirconate titanate (PZT) or barium titanate (BaTiO ₂ ), and NiCr, Ag, etc. are vapor-deposited on both surfaces to form electrodes for signal extraction. In addition to the above, the pyroelectric element may be other pyroelectric elements such as LiTiO ₃ .
Reference numeral 4 denotes a support base. As shown in FIG. 1, the support base 4 is also a rectangular parallelepiped having two height planes, with the center portion of the support base being low and both ends having high height planes. The lead frame 11 is adhered and installed with an adhesive or the like. A conductive adhesive is applied to both ends of the support 4 to fix the pyroelectric element 3. This shape is made to ensure thermal insulation of the pyroelectric element. The support 4 is made of alumina or glass epoxy. The support base 4 is wired so that the electric charge taken out from the pyroelectric element 3 can be taken out to the outside, and has an electrode that enables wire bonding.
Reference numeral 5 denotes a surface-mount type field effect transistor (FET) having an electrode capable of wire bonding. The FET 5 is adhered and installed on the lead frame 11 with an adhesive.
The sensor signal output is connected by bonding the wiring pattern of the support 4, FET 5, and lead frame 11 with an Au wire to form an internal wiring. Further, Rg (not shown) is mounted as necessary to form internal wiring.
A resin package 12 is a hollow shape covering the signal processing unit including the pyroelectric element 3, the support base 4, and the FET 5 on the lead frame 11, and is configured by molding of a resin molding technique. The resin package 12 has a vent hole 13 for taking in an air flow resulting from an external pressure change into the package. In FIG. 3, the air vent 13 is at the center of the top surface of the resin molding package 12, but it is not necessarily at the center of the top surface of the resin molding package 12. . The size of the vent is preferably about 1 mm.

The signal processing unit including the pyroelectric element 3, the support 4, and the FET 5 is coated with a resin protective film 8. The resin protective film 8 is produced by processing a coating or a solution in which a diluted film constituent material is dissolved by a dipping (DIPPING) method. The application of the resin protective film 8 has a function of protecting the sensor from the influence of outside humidity and gas. At the same time, it has the combined effect of the function of optimizing the sensitivity as a sensor by controlling the thickness of the resin protective film 8.
As the resin used for the protective resin film, a fluorine polymer, a polyolefin polymer, a paraxylene polymer, or the like is used.

  Since the micro-pressure sensor of the present invention is configured as in the first, second, and third embodiments, it is possible to cope with surface mounting when mounting the micro-pressure sensor, and the micro-pressure sensor can be used in a production line with high productivity. Units can be manufactured. In addition, it is possible to provide a micro-pressure sensor that simplifies the manufacturing process and provides high production efficiency by press-fitting the resin lid material into the package, press-fitting the resin lid material, and metal molding or molding of the resin molding technology. It becomes.

Sectional view of micro-pressure sensor related to Example 1 Sectional drawing of the micro atmospheric pressure sensor regarding Example 2 Sectional drawing of the micro atmospheric pressure sensor regarding Example 3 Micrometer pressure sensor package shape diagram of lead type package consisting of conventional metal CAM and STEM

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Ceramic package 2 External connection terminal 3 Pyroelectric element 4 Support stand 5 Field effect transistor (FET)
6 Resin lid material 7 Vent hole 8 Resin protective film 9 Metal lid material 10 Vent hole 11 Lead frame 12 Resin molding package 13 CAN
14 STEM

Claims (4)

  The sensor package has a vent hole through which gas passes, and includes a pyroelectric element in the container, an electrode for extracting electric charge from the pyroelectric element, and a signal processing unit for processing the extracted electric charge as an electric signal. The element and the signal processing part are coated with a protective coating with resin, and the pyroelectric element and the signal processing part are arranged in a micro atmospheric pressure sensor that detects a slight change in atmospheric pressure and a temperature change caused by air entering and exiting through the vent hole. A micro-pressure sensor characterized in that the package to be stored is a package corresponding to surface mounting, and is configured by a package having a shape in which one surface is opened.   2. The fine structure according to claim 1, wherein the lid member covering the opening of the surface mountable package is made of resin and is installed and configured by being press-fitted into the surface mountable package. Barometric sensor.   2. The fine structure according to claim 1, wherein the lid member having a vent hole and covering the opening of the surface mountable package is made of metal and is installed and configured by being caulked to the surface mountable package. Barometric sensor.   2. The micro atmospheric pressure according to claim 1, wherein the package having a vent hole and having a surface-mountable package opening is made of resin, and the surface-mountable package is formed by molding of a resin molding technique. Sensor.

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