JP6010394B2 - Electronic element storage package and electronic device - Google Patents

Description

  The present invention relates to an electronic element housing package and an electronic apparatus for hermetically accommodating electronic elements.

  An example of an electronic device using an electronic element is shown in a cross-sectional view in FIG. What is shown in FIG. 5 is an electronic device called an infrared detection device that houses an infrared detection element 23 that detects infrared rays (see, for example, Patent Document 1). The conventional infrared detecting device includes a base body 21 and a window plate 22 and is formed in a rectangular parallelepiped shape.

The base 21 is composed of a laminated ceramic, a pattern, and a through hole for providing a path for electrically connecting the inside and the outside of the container, for example, an alumina (Al ₂ O ₃ ) sintered body or aluminum nitride (AlN). ) A ceramic package made of a sintered material.

  The base 21 has a side wall 21a, and an infrared detection element 23 for detecting infrared rays is disposed in an opening formed by the side wall 21a with the light receiving surface 23a facing upward. The infrared detection element 23 is bonded to the inner side of the recess of the base 21 by bonding or soldering.

  Further, a step is provided on the inner surface of the side wall 21a, and a bonding wire 25 for connecting the wiring conductor 24 and the infrared detection element 23 at the step is provided.

  The flat window plate 22 is formed of, for example, germanium (Ge) or silicon (Si) that transmits infrared rays, and is bonded to the side wall 21a of the substrate 21 using a window bonding material 27 such as solder. 21 recess openings are sealed. The window plate 22 is disposed at a position facing the light receiving surface 23 a of the infrared detection element 23.

JP 2003-254820 A

  In the conventional infrared detection device, a large window plate 22 made of germanium or silicon is joined so as to cover all the openings of the base 21. However, in the manufacturing process of the electronic device, the wetting and flow of the window bonding material 27 are not constant, and the thickness of the window bonding material 27 and the occurrence of voids in the window bonding material 27 vary, resulting in airtightness of the electronic device. There was variation in sex.

  In the portion where the window bonding material 27 is thin, it is easy to peel off and the airtightness is lowered. Voids are likely to occur in the portion where the window bonding material 27 is thick. When the stress generated due to the thermal expansion and contraction of the window bonding material 27 increases, there is a problem in that the window bonding material 27 cracks from the void and the bonding material is peeled off.

  The present invention has been devised in view of the above problems, and an object of the present invention is to provide an electronic element storage package and an electronic device that can improve the airtightness of the electronic device while improving the bondability of the window plate. There is to do.

An electronic element storage package according to an embodiment of the present invention includes a base having a concave portion for storing an electronic element on an upper surface and a polygonal shape, and a window bonding material around the recess of the base. And a window plate having a polygonal main surface shape, which is hermetically sealed to seal the recess, and the window plate has a metal layer that surrounds the outer peripheral portion of the main surface. the metal layer, the formed away from the corner of the main surface at the corner portion connected along the outer circumference of the main surface, and have a thin thickness thin wall portion in the corner, the corner of the window pane in accordance with the corner of the substrate, the metal layer is characterized Rukoto joined around the recess by the window bonding material.

  In the electronic element housing package, it is preferable that the corner portion of the metal layer is linearly arranged from one side of the two sides sandwiching the corner of the main surface to the other side.

An electronic device according to an embodiment of the present invention includes the electronic element storage package, the electronic element accommodated in the recess, and the metal layer bonded to the periphery of the recess by the window bonding material. And the hermetically sealed window plate.

An electronic element storage package according to an embodiment of the present invention includes a base having a concave portion for storing an electronic element on an upper surface and a polygonal shape, and a window bonding material around the recess of the base. And a window plate hermetically sealing the recess. The window plate has a polygonal main surface and a metal layer that circulates around the outer periphery of the main surface. And this metal layer, together are formed away from the corner of the main surface at the corner portion connected along the outer periphery of the main surface of the window plate, the thickness at the corner portion is have a thin walled portion, of the window plate the combined corner on the corner of the base, from Rukoto the metal layer is bonded to the periphery of the recess by the window bonding material, together with the air gap is provided between the corners of the base of the corner and the window plate, thin portion the thickness of the window bonding material to be joined can be made thicker than the thickness of the metal layer of the other sites. As a result, when the electronic device is mounted on the external circuit board, the heat applied to the connection portion of the electronic device is not easily transmitted from the base to the corner of the window plate, and the thermal stress generated at the corner of the window plate is reduced. Further, the stress applied to the corners of the window plate due to the deformation of the base is reduced. Furthermore, it is possible to absorb the thermal stress generated in the thin portion sandwiched between two adjacent sides of the main surface by the difference in thermal expansion coefficient between the base body, the window plate, and the metal layer by the window bonding material provided in the thin portion. it can.

  In this case, when the corner portion of the metal layer is linearly arranged from one side of the two sides sandwiching the corner of the main surface to the other side, the outer peripheral portion of the window bonding material provided in the thin portion In addition, the inner periphery is linear, and thermal stress caused by the difference in thermal expansion coefficient between the base, window plate, metal layer, and window bonding material is concentrated on a part of the window bonding material provided in the thin wall portion. Is suppressed. As a result, it is possible to suppress cracks on the substrate and peeling of the metal layer, which are caused by the thermal stress concentrated on a part of the window bonding material provided in the thin portion.

An electronic device according to an embodiment of the present invention includes an electronic element storage package according to any one of the above, an electronic element accommodated in a recess, and the metal layer around the recess by the window bonding material. Since the window plate that is bonded and hermetically seals the recesses is provided, poor bonding of the window plate can be reduced, and the air tightness of the electronic device can be improved.

FIG. 1 is an exploded perspective view showing an example of an embodiment of an electronic device of the present invention.
FIG. 2 is a bottom perspective view showing an example of an embodiment of a window plate of an electronic element storage package according to the present invention.
[FIG 3] (a) is a bottom view showing an example of an embodiment of a window plate of an electronic device housing package of the present invention, (b) is the embodiment of the group of the electronic device housing package of the present invention It is a top view which shows an example.
FIG. 4 is an external perspective view showing an example of an embodiment of an electronic device of the invention.
FIG. 5 is a cross-sectional view showing an example of a conventional electronic device.

  Hereinafter, an electronic element storage package (hereinafter also simply referred to as a package) and an electronic device according to an embodiment of the present invention will be described in detail.

FIG. 1 is an exploded perspective view of an electronic device according to an embodiment of the present invention. Figure 2 is a perspective view of the window plate 2 in FIG. 1 from the lower surface side. Further, FIG. 3 (a) shows a bottom view of an example of embodiment the window plate 2 of the electronic device housing package, an example of an embodiment of FIG. 3 (b) base 1 of the electronic element housing package 4 is a top view, and FIG. 4 is a perspective view showing an appearance of an example of an embodiment of an electronic device. For easy understanding, the metal layer portion is hatched in FIGS. Therefore, they do not show a cross section.

  The window plate 2 used in the electronic device 10 according to an embodiment of the present invention has a polygonal main surface. For example, the main surface shape is a quadrangle. In addition, odd numbers such as triangles and pentagons, and even numbers such as hexagons and octagons may be used. Hereinafter, as shown in FIG. 1, FIG. 2, and FIG.

  The window plate 2 is made of, for example, a single crystal silicon (Si) plate, a single crystal germanium (Ge) plate, glass, an inorganic crystal plate, a synthetic resin plate, or the like that is transparent to infrared rays, visible light, or the like. And the metal layer 3 is formed in the outer peripheral part of the main surface (lower surface) along the four sides of the window board 2, and the outer peripheral part of the window board 2 is circulated. In the corner 2 a portion of the window plate 2, the corner portion 3 a of the metal layer 3 is formed so as to be separated from the corner 2 a of the window plate 2. In addition, a thin portion 3b having a small thickness is formed at a corner portion 3a of the metal layer 3 in a part or all of the circumferential direction. The thickness of the metal layer 3 is, for example, 25 μm to 500 μm in the thin portion 3b, and 50 μm to 1000 μm in the other metal layer 3 portions.

  The metal layer 3 is formed around the lower surface of the window plate 2, and includes, for example, a first layer made of at least one of titanium, titanium-tungsten, and tantalum nitride, and at least one kind of platinum, nickel, and nickel-chromium. It has a three-layer structure in which a second layer and a third layer made of at least one of gold, platinum, and copper are sequentially stacked. The window plate 2 is joined to the periphery of the recess 1 a of the base body 1 with a brazing material via the metal layer 3.

The thin portion 3b where the metal layer 3 is thin can be formed by reducing the number of times the metal layer is applied. For example, masking is performed on the thin portion 3b for each layering process of the metal layer 3 to deposit the metal on the formation portion of the metal layer 3, and then the masking is removed or the deposition is further performed by changing the position. By sequentially repeating each layer, the metal layer 3 having the thin portion 3b can be formed. Thus formed, the thickness of the thin portion 3 b may be the about half of the other metal layer 3 thickness.

  The metal layer 3 portion of the window plate 2 thus produced is bonded to the upper surface of the substrate 1 via a brazing material such as gold-tin brazing, gold-germanium brazing, silver-tin brazing, or a resin adhesive. The base body 1 is formed with a concave portion 1a for accommodating the electronic element 4 at the center of the upper surface. By bonding the window plate 2 around the recess 1a, the inside of the recess 1a is hermetically sealed, and the electronic element 4 is hermetically stored in the recess 1a.

The substrate 1 is made of alumina (Al ₂ O ₃ ) ceramics, aluminum nitride (AlN) ceramics, mullite (3Al ₂ O ₃ · 2SiO ₂ ) ceramics, resin, glass, or the like. A metal may be used.

  In the case where the substrate 1 is made of ceramics, an electronic element housing package having a high degree of freedom in forming the wiring conductor 5 on the substrate 1 can be obtained. That is, the wiring conductor 5 can be routed around the base body 1 in accordance with the position of the electrode of the electronic element 4, the position of the connecting portion for connecting the package to the external electric circuit board, and the like, and the degree of freedom in designing the wiring conductor 5. Can be high package. A ceramic package is also preferable from the viewpoint of dimensional accuracy of the package.

  A metallized metal layer 1b made of tungsten, molybdenum, manganese or the like is deposited around the recess 1a on the upper surface of the substrate 1. Preferably, a metal frame (not shown) made of metal such as iron (Fe) -nickel (Ni) -cobalt (Co) alloy or iron-nickel alloy is bonded to the metallized metal layer 1b. Good.

Then, the metallized metal layer 1b or the metal frame and the metal layer 3 of the window plate 2 are bonded via a brazing material or a resin adhesive, and the window plate 2 is bonded to the base 1. At this time, since the thin portion 3b is provided in the metal layer 3, the thickness of the brazing material or the adhesive is increased in the thin portion 3b. The thickness of the brazing material is 50 μm to 1075 μm at the thin portion 3 b and 25 μm to 100 μm at the metal layer 3 portion that is not the thin portion 3 b.

Thereby, the thickness together with the air gap is provided, a window bonding material provided the thickness of the window bonding material provided in the thin portion 3b on the other metal layer 3 between the corner 2a of the corner and the window plate 2 base 1 It can be made thicker. As a result, when the electronic device 10 is mounted on the external circuit board, the electronic device 1
Heat applied to the wiring conductor 5 serving as the 0 connection terminal is hardly transmitted from the base 1 to the corner 2a of the window plate 2, and the thermal stress generated at the corner of the window plate 2 is reduced. Further, the stress applied to the corner 2a of the window plate 2 due to the deformation of the base body 1 is reduced. Further, the window bonding material provided in the thin portion 3b is caused by the difference in thermal expansion coefficient among the base 1, the window plate 2, and the metal layer 3 and is generated in the thin portion 3b sandwiched between two adjacent sides of the main surface. Can be absorbed. Also in this case, the alignment of the window plate 2 can be facilitated by matching the corner 2a of the window plate 2 with the corner of the base 1.

  As shown in FIGS. 2 and 3 (a), the corner 3a of the metal layer 3 is preferably arranged linearly from one side of the two sides sandwiching the corner 2a of the window plate 2 to the other side. . As a result, the outer peripheral portion and the inner peripheral portion of the window bonding material provided in the thin wall portion 3b are linear, and heat generated due to the difference in thermal expansion coefficient between the base 1, the window plate 2, the metal layer 3, and the window bonding material. It is suppressed that stress concentrates on a part of window bonding material provided in the thin part 3b. As a result, it is possible to suppress cracks to the base 1 and peeling of the metal layer 3 caused by the thermal stress concentrating on a part of the window bonding material provided in the thin portion 3b.

In the case all of the corner 3a is not thin portion 3b, preferably provided a thin portion 3 b in the central portion of the corner portion 3a. In this case, the bonding interface between the window bonding material and the metal layer 3 in the thin wall portion 3b is provided on the thin wall portion 3b side from the corner positioned between one side of the metal layer 3 and the corner portion 3a. The stress generated at the corner located between one side and the corner 3a and the stress generated at the bonding interface between the window bonding material and the metal layer 3 in the thin-walled portion 3b do not overlap and can be dispersed. . As a result, the corner positioned between one side of the metal layer 3 and the corner 3a, cracks in the base 1 starting from the bonding interface between the window bonding material and the metal layer 3 in the thin portion 3b, the metal layer 3 and Peeling of the window bonding material can be suppressed.

  When an infrared detecting element or an infrared light emitting element is used as the electronic element 4, the window plate 2 is preferably made of single crystal silicon or single crystal germanium. Since the window plate 2 is a single crystal substrate, there is no crystal grain boundary, and light diffusion due to impurities contained in the crystal grain boundary does not occur. Therefore, the infrared light which permeate | transmits the window board 2 can permeate | transmit the window board 2 efficiently from the package exterior to the inside or the package interior to the exterior. Moreover, the light reflected on the surface of the window plate 2 can be reduced by previously applying a non-reflective coating to the main surface on which the light of the window plate 2 is incident.

When an element in the visible light region is used as the electronic element 4, the window plate 2 is made of amorphous glass, sapphire, acrylic resin, epoxy resin, or the like. Also in this case, the light reflected on the surface of the window plate 2 can be reduced by previously applying a non-reflective coating to the main surface on which the light of the window plate 2 is incident.

  Next, an example of a method for forming each part of the electronic element storage package will be described.

  When the substrate 1 is made of alumina ceramics, for example, it is manufactured as follows. Similarly, when it is made of other ceramics, it can be formed by a well-known method.

First, a suitable organic binder, a plasticizer, a dispersant, a solvent, etc. are added to and mixed with raw material powders such as alumina, silicon oxide (SiO ₂ ), calcium oxide (CaO), magnesium oxide (MgO) to form a slurry. A plurality of ceramic green sheets are obtained by forming this into a sheet shape by a conventionally known doctor blade method or calendar roll method.

  Next, an appropriate punching process is performed on these ceramic green sheets to form punched portions that become the recesses 1a and the like. A conductive paste obtained by mixing an appropriate binder and solvent with metal powder such as tungsten (W), molybdenum (Mo), manganese (Mn), or the like, which will be the wiring conductor 5, is formed on the inner surface of the recess 1 a. A predetermined pattern is printed on the position by screen printing or the like. In this way, a conductor paste layer to be the wiring conductor 5 is formed on the inner surface of the recess 1a. The ceramic green sheets on which the punched portions and the conductor paste layer are formed are stacked and fired in a reducing atmosphere at a temperature of about 1600 ° C., thereby forming the wiring conductor 5 made of the metallized metal layer. The substrate 1 is manufactured.

  Further, in the base 1 made of ceramic, a metallized metal layer made of tungsten, molybdenum, manganese, or the like, which is the same as the wiring conductor 5, is deposited on the joint portion of the window plate 2 and, if necessary, the mounting portion of the electronic element 4. It is good to keep. Thereby, the window plate 2 and the electronic element 4 can be firmly bonded using a bonding material made of gold-tin brazing, gold-germanium brazing, silver-tin brazing, resin adhesive or the like. Even when a metal frame is used, the metal frame can be firmly joined.

When the base 1 is made of a resin, the window plate 2 can be firmly joined using a brazing material or the like by providing a metal frame. The metal frame is provided by embedding a part of the lower side in a resin by molding. The metal frame is formed by a conventionally known metal processing method such as pressing, cutting, and etching.

  Note that the metal layer such as the wiring conductor 5 formed on the surface of the substrate 1, the metallized metal layer 1 b for bonding the window plate 2, and the metallized metal layer for bonding the electronic element 4 has excellent corrosion resistance and is free of brazing material. A metal having excellent wettability, specifically, a nickel layer having a thickness of 0.5 to 9 μm and a gold (Au) layer having a thickness of 0.5 to 5 μm may be sequentially deposited by a plating method.

  Next, the electronic device 10 according to an embodiment of the present invention will be described.

  In an electronic device 10 according to an embodiment of the present invention, an electronic element 4 is accommodated in a recess 1 a, and the recess 1 a is hermetically sealed by a window plate 2. In FIG. 1, the electronic element 4 is mounted and fixed on the bottom surface of the recess 1a, and the window plate 2 is joined to the upper surface of the base 1, and the electronic element 4 is hermetically sealed in the recess 1a. The electronic device 10 can be an inexpensive electronic device 10 with high operational reliability using an electronic element storage package.

The electronic element 4 is a semiconductor element for infrared detection such as a diode type or a bolometer type, and is placed and fixed on the bottom surface of the recess 1a via a bonding material. The element bonding material is made of gold-tin brazing, gold-germanium brazing, silver (Ag) -tin (Sn) brazing, resin adhesive, or the like. In addition, an optical semiconductor element such as an LD, a light emitting element, and a light receiving element can also be used.

  The electronic element 4 is placed and fixed on the bottom surface of the recess 1 a of the base 1 via a bonding material, and then the electrode of the electronic element 4 provided on the top surface of the electronic element 4 is provided in the recess 1 a of the base 1. The conductor 5 is electrically connected via an electrical connection means such as a bonding wire. Then, the window plate 2 is positioned so as to face the electronic element 4 and bonded to the upper surface of the substrate 1 in an atmosphere of vacuum or nitrogen or inert gas, and the inside of the package is made of inert gas such as vacuum or nitrogen. Seal hermetically while maintaining the atmosphere.

  In the example of the package shown in FIG. 2, the wiring conductor 5 is formed on the bottom surface of the recess 1a. The electronic element 4 is connected to the wiring conductor 5 by a bonding wire. The wiring conductor 5 is led out from the inside of the base body 1 and connected to an external electric circuit, whereby an electric signal can be input / output between the electronic element 4 and the external electric circuit, and the electronic device 10 functions. To come.

  The present invention is not limited to the above-described embodiments and examples, and various modifications may be made without departing from the scope of the present invention.

1: Base 1a: Recess 1b: Metallized metal layer 2: Window plate 2a: Corner 3: Metal layer 3a: Corner 3b: Thin part 4: Electronic element 5: Wiring conductor 10: Electronic device

Claims (3)

A main surface having a concave portion for accommodating an electronic element on the upper surface, and a base having a polygonal shape, and is joined to the periphery of the concave portion of the base via a window bonding material to hermetically seal the concave portion. A window plate having a polygonal shape, and the window plate has a metal layer that circulates around an outer peripheral portion of the main surface, and the metal layer has a corner along the outer periphery of the main surface. formed away from the corner of the main surface in section, and have a thin thickness thin wall portion in the corner portion, the combined corner of the window plate in the corner of the substrate, wherein the metal layer is the window bonding material The electronic device storing package, wherein the electronic device storing package is bonded to the periphery of the recess .   The said corner | angular part of the said metal layer is arrange | positioned linearly from one side of two sides which pinches | interposes the corner | angular of the said main surface to another one side, The electronic device accommodation of Claim 1 characterized by the above-mentioned. package. The electronic element storage package according to claim 1, the electronic element stored in the recess, and the window in which the metal layer is bonded around the recess by the window bonding material and the recess is hermetically sealed. An electronic device comprising a plate.

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