JP6010393B2 - 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. 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 23a of the infrared detecting element 23 (see, for example, Patent Document 1).

JP 2003-254820 A

  However, in the conventional infrared detection device, a rectangular window plate 22 made of large germanium or silicon is joined so as to cover all the openings of the base 21. When the window bonding material 27 is melted and the window plate 22 is bonded to the side wall 21a, a thermal stress is generated at the corner portion of the window plate 22 due to a difference in thermal expansion coefficient from the window bonding material 27, and the window plate 22 has a side wall 21a. There was a problem that it was easy to peel off from the upper surface.

  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 in which the bonding reliability of the window plate is improved.

An electronic element storage package according to an embodiment of the present invention includes a base having a recess formed on the upper surface for storing an electronic element, and the recess formed by being bonded to the periphery of the recess of the base via a bonding material. The main plate has a polygonal window plate, and the window plate circulates around the outer peripheral portion of the main surface and has a thin portion with a small thickness in part . A metal layer bonded to the periphery of the recess is formed through the bonding material, and the thin portion is separated from corner portions on both sides of the window plate .

  In the electronic element storage package, the thin portion may be provided at a central portion of one side of the outer peripheral portion.

  Furthermore, it is preferable that a plurality of the thin portions are provided on one side of the outer peripheral portion.

  An electronic device according to an embodiment of the present invention includes any one of the electronic element housing packages described above, an electronic element housed in the recessed portion, and the window plate hermetically sealing the recessed portion.

  An electronic element storage package according to an embodiment of the present invention includes a base having a recess formed on the upper surface for storing an electronic element, and a polygon that is joined around the recess of the base and hermetically seals the recess. The window plate has a metal layer that circulates around the outer peripheral portion of the main surface and has a thin portion with a small thickness. When joining to the substrate, the melted liquid phase window bonding material can be stored in the thin wall portion, and the thickness of the window bonding material provided between the metal layer excluding the thin wall portion and the upper surface of the substrate should be reduced. Can do. Therefore, the thermal stress is reduced at the portion where the thickness of the window bonding material is reduced, and the thickness of the window bonding material is increased at the thin wall portion to ensure the bonding strength of the window bonding material, thereby joining the metal layer and the window bonding material. can do.

  In this case, if the thin portion is provided at the central portion of one side of the outer peripheral portion, the thermal stress and residual stress generated between the metal layer and the upper surface of the base body are symmetric with respect to the central portion of the one side. Moreover, a thin part is arrange | positioned in the part most distant from the corner part of a window plate, and the crack and peeling which arise in the corner junction part of a window plate and a base | substrate are suppressed.

  Moreover, when the thin part is provided with two or more by the side in an outer peripheral part, the joining area of a metal layer and a window joining material will increase, and joining force will increase.

  An electronic device according to an embodiment of the present invention includes any one of the above-described electronic element storage packages, an electronic element accommodated in a recess, and the window plate hermetically sealed in the recess. Therefore, the bonding force of the window plate is improved, and an electronic device with good bonding reliability can be obtained.

It is a perspective view which shows an example of embodiment of the window plate used for the package for electronic element accommodation of this invention. It is a disassembled perspective view which shows an example of embodiment of the electronic device of this invention. It is an external appearance perspective view which shows an example of embodiment of the electronic device of this invention. It is a bottom view which shows the other example of embodiment of the window plate used for the electronic element storage package of this invention. It is sectional drawing which shows the example of the 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 a perspective view showing a lower surface of a window plate 2 part of an electronic device according to an embodiment of the present invention. FIG. 2 is an exploded perspective view showing an example of an embodiment of the electronic device, and FIG. 3 is a perspective view showing an appearance of the electronic device. FIG. 4 is a bottom view showing examples of various embodiments of the window plate 2 part. 2, 3, and 4, the portion provided with the metallized metal layer is hatched for easy understanding. 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, as shown in FIG. 1, 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, a case where the main surface shape is a square will be described as an example.

  The window plate 2 is transparent to infrared rays, visible light, etc., for example, from a single crystal silicon (Si) plate, a single crystal germanium (Ge) plate, an amorphous glass, an inorganic crystal plate, a synthetic resin plate, etc. Become. A metal layer 3 is formed on the outer periphery along the four sides of the window plate 2. A thin portion 3a having a small thickness is formed in a part of the length direction on at least the metal layer 3 on the outer peripheral portion of one side of the window plate 2. The thickness of the metal layer 3 is, for example, 25 μm to 500 μm at the thin portion 3 a and 50 μm to 1000 μm at the other metal layer 3 portions.

  The metal layer 3 is formed around one main surface of the window plate 2, and is made of, for example, a first layer made of at least one of titanium, titanium-tungsten, and tantalum nitride, and at least one of platinum, nickel, and nickel-chromium. And 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 formed. The window plate 2 is bonded to the periphery of the recess of the base body 1 with a brazing material via the metal layer 3.

  The thin portion 3a where the metal layer 3 is thin can be formed by reducing the number of times the metal layer is applied. For example, the thin layer portion 3a is masked for each layering step of the metal layer 3 to deposit the metal layer 3, and then the masking is removed or the metal layer 3 is further stacked at different positions. The metal layer 3 having the thin portion 3a can be formed by sequentially repeating each formation step. If formed in this way, the thickness of the thin portion 3 can be about half of the thickness of the other metal layer 3. Alternatively, a metal layer is formed around the lower surface of the window plate 2, a metal plate is joined to a portion other than the thin portion 3 a through a brazing material, and the metal layer and the metal plate are provided as the metal layer 3. Also good.

  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 sealed and protected.

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.

  When the substrate 1 is made of ceramics, an electronic element 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. Moreover, it is preferable that it consists of ceramics also from a viewpoint of the dimensional accuracy of a 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 window bonding material made of 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 3a is provided in the metal layer 3, excess brazing material or adhesive flows in the thin portion 3a, and the thickness of the window bonding material is increased.

  As a result, when the brazing material used as the window joining material is melted and the window plate 2 is joined to the metallized layer 1b, the surplus brazing material flows into the thin portion 3a, and a portion of the brazing portion other than the thin portion 3a correspondingly flows. The material thickness can be reduced. Therefore, it is possible to reduce the thermal stress generated in the brazing material and the window plate 2 other than the thin wall portion 3a, and to secure the bonding amount of the brazing material by securing the brazing material amount in the thin wall portion 3a. Since the excess brazing material can flow into the thin wall portion 3a, a sufficient brazing material can be supplied to the joining portion at the time of joining. Further, by reducing the thickness of the brazing material, voids generated in the window bonding material can be reduced.

  The thin part 3a of the metal layer 3 is preferably provided at the center of one side as shown in FIGS. By being provided in the center part, the distance of the thin part 3a from the corner part of the one side both sides of the window board 2 can be made the largest. Therefore, mutual interference between the thermal stress generated in the corner portion and the thermal stress generated in the thin portion 3a can be reduced.

  Moreover, as shown in FIG.4 (b), the thin part 3a may be provided with two or more by each edge | side. By providing a plurality, the bonding surface between the window bonding material and the metal layer 3 becomes large, so that the bonding force by the thin portion 3a can be increased.

  Moreover, as shown in FIG.4 (b), the some thin part 3a is good to arrange | position and arrange | position in the symmetrical position regarding the center of the window plate 2. As shown in FIG. By providing symmetrically, the distance from the corner part to the thin part 3a can be maximized.

  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 substrate 1 is made of a resin, it can be firmly bonded using a window plate and a brazing material 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.

  The metal layer such as the wiring conductor 5 formed on the surface of the substrate 1, the metal layer 1b for joining the window plate 2, and the metal layer for joining the electronic element 4 has excellent corrosion resistance and wettability with the brazing material. It is preferable to deposit a metal excellent in thickness, 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 sequentially 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 is accommodated in a recess 1 a, and the recess 1 a is hermetically sealed by a window plate 2. In FIG. 2, 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 electrode of 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: Substrate 1a: Concave portion 1b: Metallized metal layer 2: Window plate 3: Metal layer 3a: Thin portion 4: Electronic element 5: Wiring conductor 10: Electronic device

Claims (4)

A base having a concave portion for accommodating an electronic element on the upper surface, and a window having a polygonal main surface that is bonded to the periphery of the concave portion of the base via a bonding material to hermetically seal the concave portion A metal plate that circulates around the outer peripheral portion of the main surface and has a thin portion with a small thickness, and is joined to the periphery of the concave portion via the bonding material. A package for storing an electronic element , wherein a layer is formed and the thin portion is separated from corner portions on both sides of one side of the window plate .   The electronic element housing package according to claim 1, wherein the thin portion is provided at a central portion of one side of the outer peripheral portion.   3. The electronic element housing package according to claim 1, wherein a plurality of the thin portions are provided on one side of the outer peripheral portion.   An electronic device comprising: the electronic element housing package according to claim 1; an electronic element housed in the recess; and the window plate hermetically sealing the recess.

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