JP2015142014A - Element housing package and mounting structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an element housing package and a mounting structure with excellent sealability.SOLUTION: An element housing package 2 comprises: a substrate 4 having a mounting region R to mount an element 3 on an upper surface thereof; a metal frame 5 on the substrate 4, surrounding the mounting region R and having a through hole H which penetrate the metal frame 5 in a plane direction along the upper surface; and an input/output terminal 8 provided in the through hole H, and having lead terminals 6 and a fixing member 7 to fix each lead terminal 6. The fixing member 7 includes a lead through hole Hl, and the lead through hole Hl has a glass member 9 inside thereof. The lead terminal 6 penetrates the glass member 9. A portion P is a part of the lead terminal 6, protruding from the glass member 9. The glass member 9 is raised at the portion P along to a surface of the portion P.

Description

  The present invention relates to an element storage package capable of mounting an element and a mounting structure on which the element is mounted.

  As an element storage package, products corresponding to various applications have been developed. The element storage package is provided with lead terminals for electrically connecting the element and an external device.

  As an element storage package, for example, a package capable of mounting a modulation element made of a ferroelectric element LN (lithium niobate) has been developed. In such an element storage package, there is a package in which lead terminals are fixed via an insulating member made of glass (for example, see Patent Document 1 below).

JP 2001-68691 A

  When the lead terminal is fixed with an insulating member made of glass, a crack may occur in the insulating member due to a difference in thermal expansion coefficient between the lead terminal and the insulating member, which may impair the sealing performance of the package. In particular, when the insulating member is cooled and the lead terminal is fixed to the insulating member, cracks are likely to occur due to stress generated at the boundary between the lead terminal and the insulating member.

  It is an object of the present invention to provide an element storage package and a mounting structure excellent in sealing performance.

  An element storage package according to an embodiment of the present invention includes a substrate having a mounting region for mounting an element on an upper surface, and surrounds the mounting region on the substrate and penetrates in a planar direction along the upper surface. An input / output terminal having a metal frame having a through hole and a lead terminal and a fixing member for fixing the lead terminal provided in the through hole, the fixing member having a lead through hole, A glass member is provided in the lead through hole, and the lead terminal penetrates the glass member, and the glass member rises over the surface of the portion in a portion protruding from the glass member. And

  A mounting structure according to an embodiment of the present invention includes the element storage package and an element mounted on the mounting region in the element storage package.

  The present invention can provide an element storage package and a mounting structure excellent in sealing performance.

It is a mounting structure concerning one embodiment of the present invention, and is an appearance perspective view showing the state where a lid was removed. It is the general-view perspective view which showed the element storage package which concerns on one Embodiment of this invention. It is the top view which showed the element storage package which concerns on one Embodiment of this invention. It is the side view which showed the lead terminal of the package for element storage which concerns on one Embodiment of this invention. It is the external appearance perspective view which showed the input / output terminal which is a part of the element storage package which concerns on one Embodiment of this invention from one direction. It is the external appearance perspective view which showed the input / output terminal which is a part of the element storage package which concerns on one Embodiment of this invention from the other direction. It is a top view of the input-output terminal which is a part of the element storage package which concerns on one Embodiment of this invention. It is sectional drawing which showed the inside of the input-output terminal shown in FIG.

  Hereinafter, an element storage package and a mounting structure according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is an external perspective view of the mounting structure 1 and shows the inside of the package. FIG. 2 is an external perspective view showing the inside of the element storage package 2. FIG. 3 is a plan view showing the inside of the element storage package 2. FIG. 4 is a side view showing the lead terminals of the element storage package 2.

<Configuration of mounting structure>
The mounting structure 1 is a structure in which a modulation element as an element made of LN (lithium niobate) which is a ferroelectric element is mounted. The mounting structure 1 outputs a light to the outside by changing a phase, an amplitude, a polarization plane, or the like by adding a modulation signal to a specific light input.

  The mounting structure 1 includes an element storage package 2 and an element 3 mounted in a mounting region R in the element storage package 2. The element storage package 2 includes a substrate 4 having a mounting region R for mounting the element 3 on the upper surface, and a through-hole H that surrounds the mounting region R on the substrate 4 and penetrates in the planar direction along the upper surface. And an input / output terminal 8 having a lead terminal 6 and a fixing member 7 for fixing the lead terminal 6 provided in the through hole H. The fixing member 7 has a lead through hole Hl, and a glass member 9 is provided in the lead through hole Hl. The lead terminal 6 penetrates the glass member 9 and at a portion P protruding from the glass member 9. The glass member 9 is raised over the surface of the portion P.

  The element 3 is a modulation element made of, for example, lithium niobate. The element 3 is mounted on the pedestal 3a. The pedestal 3 a is provided in the mounting region R inside the element storage package 2. The pedestal 3a mounts the element 3 and can adjust the height position of the element 3. The pedestal 3a is made of an insulating material, and electrical wiring that is electrically connected to the element 3 is formed on the upper surface of the pedestal 3a.

The board | substrate 4 is a rectangular-shaped metal plate, Comprising: For example, it consists of metal materials, such as copper, iron, tungsten, molybdenum, nickel, or cobalt, or the alloy containing these metal materials. The thermal conductivity of the substrate 4 is set to, for example, 15 W / (m · K) or more and 450 W / (m · K) or less. The thermal expansion coefficient of the substrate 4 is set to, for example, 3 × 10 ⁻⁶ / K or more and 28 × 10 ⁻⁶ / K or less.

The substrate 4 is manufactured in a predetermined shape by using a conventionally known metal processing method such as rolling or punching for an ingot obtained by casting and solidifying a molten metal material into a mold. The length of one side of the substrate 4 when viewed in plan is, for example, 20 mm or more and 200 m.
m or less. The thickness of the substrate 4 in the vertical direction is set to, for example, 0.5 mm or more and 5 mm or less.

  Further, a metal layer such as nickel or gold is formed on the surface of the substrate 4 by using an electroplating method or an electroless plating method in order to prevent oxidative corrosion. The thickness of the metal layer is set to, for example, 0.1 μm or more and 10 μm or less.

  The metal frame 5 is provided on the substrate 4. The metal frame 5 includes a frame-shaped portion 51 that surrounds the mounting region R of the substrate 4, and a plurality of through holes H formed in the frame-shaped portion 51 in the planar direction along the upper surface of the substrate 4. Through holes H are provided on three sides of the four sides of the frame-like portion 51. And the fiber attachment part 10 which lets an optical fiber pass to the through-hole H of two opposing sides is provided. In addition, an input / output terminal 8 provided with a lead terminal 6 is provided on one side sandwiched between the two sides provided with the fiber mounting portion 10. A connector member 11 is provided on the one side.

The metal frame 5 is made of, for example, a metal material such as copper, iron, tungsten, molybdenum, nickel, or cobalt, or an alloy containing these metal materials. The metal frame 5 has a function of efficiently dissipating heat generated from the element 3 to the outside, a function of absorbing and dispersing thermal stress, and a function of hermetically sealing the mounting structure 1. The thermal conductivity of the metal frame 5 is set to, for example, 15 W / (m · K) or more and 450 W / (m · K) or less. The thermal expansion coefficient of the metal frame 5 is set to 3 × 10 ⁻⁶ / K or more and 28 × 10 ⁻⁶ / K or less, for example. Further, the thickness of the metal frame 5 is set to be, for example, 1 mm or more and 10 mm or less. Moreover, the thickness of the frame when the metal frame 5 is viewed in plan is set to, for example, 1 mm or more and 5 mm or less.

  One of the pair of fiber attachment portions 10 is for light input, and the other is for light output. The light input from the one fiber attachment portion 10a through the optical fiber is output from the other fiber attachment portion 10b while changing the phase, amplitude, or polarization plane on the modulation element 3. That is, the light input from the fiber attachment portion 10a is changed due to the electrical signal input from the connector member 11 via the element 3, and is output from the fiber attachment portion 10b.

  As shown in FIGS. 5 to 8, the input / output terminal 8 includes a lead terminal 6 provided in the through hole H and a fixing member 7 for fixing the lead terminal 6. The input / output terminal 8 is for applying a bias voltage to the element 3 or inputting an electric signal into the element housing package 2. FIG. 5 is an external perspective view as seen from one direction of the input / output terminal having the lead terminal. FIG. 6 is an external perspective view of the input / output terminal having the lead terminal as seen from the other direction. FIG. 7 is a plan view of an input / output terminal having a lead terminal. 8 is a cross-sectional view showing the inside of the input / output terminal shown in FIG.

The lead terminal 6 has a rectangular cross section and a rod shape. Specifically, the lead terminal 6 has a rectangular cross section and is formed in a rectangular shape. The lead terminal 6 is electrically connected to an external electronic device, and receives a bias voltage and an electric signal from the external electronic device. The lead terminal 6 has a length in the longitudinal direction of 10 mm or more and 20 mm or less. The length of one side of the cross section in the direction orthogonal to the longitudinal direction is not less than 0.1 mm and not more than 1 mm. In the cross section, the length of the long side is 0.15 mm to 1 mm, and the length of the short side is 0.1 mm to 0.95 mm. Note that the lead terminal 6 is made of a conductive material, for example, a metal material such as copper, iron, tungsten, molybdenum, nickel, or cobalt, or an alloy containing these metal materials. The thermal expansion coefficient of the lead terminal 6 is set to 3 × 10 ⁻⁶ / K or more and 28 × 10 ⁻⁶ / K or less, for example.

In the lead terminal 6, for example, two of the four side surfaces are rougher than the remaining two side surfaces. Further, the side surface of the lead terminal 6 provided in the direction orthogonal to the longitudinal direction of the fixing member 7 is roughened. When the glass member 9 is melted, for example, the side surface of the hydrophilic lead terminal 6 on which a metal layer made of nickel is deposited is easily wetted and spread on the roughened side surface. The lead terminal 6 has a roughened surface having an arithmetic average roughness (Ra) of 0.6 μm or more and 50 μm or less, and an unroughened surface has a surface roughness of arithmetic. The average roughness (Ra) is set to 0.1 μm or more and 0.5 μm or less. The arithmetic average roughness (Ra) is measured according to JISB0601.

  The lead terminal 6 is provided with a protective member on a pair of side surfaces parallel to the longitudinal direction of the fixing member 7, and by subjecting the pair of side surfaces orthogonal to the longitudinal direction of the fixing member 7 to surface processing such as etching or blasting, Any side is intentionally roughened and the surface roughness is adjusted. Specifically, the surface roughness of a specific side surface can be increased by providing a protective film on a pair of side surfaces parallel to the longitudinal direction of the fixing member 7 and processing the surface of the lead terminal 6 with an etching solution. it can.

  The roughened side surface of the lead terminal 6 and the non-roughened side surface of the lead terminal 6 are alternately arranged in the four side surfaces. Therefore, the glass member 9 is attached to both sides of the lead terminal 6 with the lead terminal 6 interposed therebetween. The lead terminal 6 is provided on the fixing member 7 so that the pair of roughened side surfaces are orthogonal to the longitudinal direction of the fixing member 7, and the glass member 9 is covered along the pair of roughened side surfaces. Worn.

  The fixing member 7 has a lead through hole Hl, and a glass member 9 is provided in the lead through hole Hl. A plurality of lead through holes Hl are provided in the fixing member 7. The plurality of lead through holes Hl are provided at equal intervals in one direction. The lead through hole Hl is formed in a circular shape. The lead through hole Hl is set to have a diameter of 0.3 mm or more and 3 mm or less, for example.

  The lead terminal 6 penetrates the glass member 9. The lead terminal 6 protrudes from the surface of the portion P provided in the direction orthogonal to the longitudinal direction of the fixing member 7 in the portion P protruding from the glass member 9. The lead terminal 6 is provided so as not to contact the inner peripheral surface of the through hole Hl of the fixing member 7. Therefore, the lead terminal 6 and the fixing member 7 are in an electrically insulated relationship.

  Here, a method for fixing the lead terminal 6 to the fixing member 7 will be described. First, a cylindrical solid glass is prepared. The solid glass can be produced using a known powder pressing method, extrusion molding method, or the like. The solid glass has an outer diameter corresponding to the inner diameter of the lead through hole Hl and an inner diameter corresponding to the size of the lead terminal 6. Then, the solid glass is fitted into the lead through hole Hl, and the lead terminal 6 is further inserted into the cylindrical hole of the solid glass. Then, the solid glass is heated at a predetermined temperature to melt and soften the solid glass, and after adhering to the lead terminal 6 and the lead through hole Hl, cooling and solidifying the lead terminal 6 and lead penetration. The hole Hl can be bonded with the glass member 9. At this time, the lead terminal 6 and the solid glass are fixed to the lead through hole Hl using an assembly jig. The solid glass is heated and softened to such an extent that the solid glass can be held between the lead terminal 6 and the lead through hole Hl, and then cooled after being bonded to the lead terminal 6 and the lead through hole Hl. 6 can be fixed to the fixing member 7 through the glass member 9.

The glass member 9 is filled in the lead through hole Hl of the fixing member 7. Then, both end portions of the lead terminal 6 protrude from the glass member 9. The glass member 9 fixes the lead terminal 6 to the fixing member 7 so that the lead terminal 6 does not contact the fixing member 7. One end of the lead terminal 6 is electrically connected to an external electronic device, and the other end of the lead terminal 6 is electrically connected to the element 3. The glass member 9 is made of a material such as borosilicate glass, phosphate glass, or silicate glass. The thermal expansion coefficient of the glass member 9 is set to 3 × 10 ⁻⁶ / K or more and 20 × 10 ⁻⁶ / K or less, for example.

  The connector member 11 is for connecting a coaxial terminal. The electric signal from the coaxial terminal is transmitted to the modulation element 3. The connector member 11 can be electrically connected to the outside by connecting an external coaxial terminal. The connector member 11 includes a pair of through-holes, a cylindrical body fitted in the pair of through-holes, and a coaxial core wire provided through the through-hole.

  The cylindrical body can be fitted with a coaxial terminal, and electrically connects the coaxial core wire and the coaxial terminal. A cylindrical body consists of iron, nickel, cobalt, copper, or these alloys, for example, and can be produced by processing it with a metal mold | die or cutting. The cylindrical body has an inner diameter set to, for example, 1 mm or more and 5 mm or less.

  The coaxial core wire is provided in a region surrounded by a cylindrical body via a dielectric such as ceramics or low-melting glass. The coaxial core wire is electrically connected to the modulation element 3. The coaxial core wire is made of a conductive material such as iron, nickel, cobalt, copper, or an alloy thereof.

  The lid 12 is provided on the metal frame 5. A lid 12 is provided on the metal frame 5 in a state where the element 3 is mounted in the mounting region R. The lid 12 can seal a space surrounded by the substrate 4 and the metal frame 5. The lid 12 is brazed onto the metal frame 5 via a brazing material, for example, or joined to the metal frame 5 by seam welding. The lid 12 is made of, for example, a metal material such as copper, iron, tungsten, molybdenum, nickel, or cobalt, or an alloy containing these metal materials.

  In the mounting structure 1 described above, an optical signal input from an optical fiber attached to one of the fiber attachment portions 10 propagates through an optical waveguide provided inside the element 3 made of lithium niobate and has an input / output terminal. The voltage based on the bias voltage from 8 and the electric signal from the coaxial terminal of the connector member 11 is applied to the electrode provided in the vicinity of the optical waveguide, whereby the phase of the optical signal input from the optical fiber is controlled, The amplitude (ON / OFF) of the optical signal output to the outside from the optical fiber attached to the other fiber attachment portion 10 can be intentionally controlled. Such a mounting structure is called an LN modulator. The input / output terminal 8 of the LN modulator has a lead terminal 6 fixed to the lead through-hole Hl by a glass member 9, and a through-hole in which the fixing member 7 is provided in the metal frame 5 via a bonding material such as solder. When the glass member 9 is inserted and fixed, the glass member 9 is prevented from cracking due to the stress caused by the difference in the thermal expansion coefficients of the metal frame 5, the lead terminal 6, the fixing member 7, the glass member 9 and the bonding material. This is very important.

  In the element housing package 2 according to this embodiment, the glass member 9 rises over the surface of the lead terminal 6 provided in the direction orthogonal to the longitudinal direction of the fixing member 7 in the portion P protruding from the glass member 9 of the lead terminal 6. As a result, the exposed surface of the glass member 9 rises over the side surface of the lead terminal 6 provided in a direction orthogonal to the longitudinal direction of the fixing member 7. If the exposed surface of the glass member 9 is assumed to be flat, the metal frame 5, the lead terminal 6, the fixing member 7 and the glass member 9, and the bonding material for bonding the fixing member 7 and the metal frame 5 In particular, in the case of the prismatic lead terminal 6 due to the difference in thermal expansion coefficient, stress is applied to the glass member 9 from the corner of the lead terminal 6, and cracks may occur in the glass member 9 starting from the corner of the lead terminal 6. There is. Therefore, the surface of the glass member 9 is not flat, and a part of the glass member 9 is deposited on the surface of the lead terminal 6 to disperse the stress applied to the glass member 9 from the lead terminal 6 and lead. By increasing the bonding strength at the bonding interface between the terminal 6 and the glass member 9, it is possible to reduce the occurrence of cracks in the glass member 9. As a result, it is possible to provide the element housing package 2 and the mounting structure 1 having excellent sealing properties.

  Further, in the element storage package 2 according to the present embodiment, the glass member 9 protrudes along two side surfaces provided in a direction orthogonal to the longitudinal direction of the fixing member 7 among the four side surfaces of the lead terminal 6. Provided. For example, the glass member 9 is not roughened because the two side surfaces provided in the direction orthogonal to the longitudinal direction of the fixing member 7 are rougher than the remaining two side surfaces. It becomes difficult to spread along the surface of the lead terminal 6 and easily spread along the side surface of the roughened lead terminal 6. As a result, the lead terminal 6 is provided with a glass member 9 protruding from the side surface of the roughened lead terminal 6 provided in a direction orthogonal to the longitudinal direction of the fixing member 7, and the lead terminal 6 is not roughened. The glass member 6 is not provided in a protruding shape on the side surface. The glass member 9 is heated and melted to such an extent that it is held between the lead terminal 6 and the lead through hole Hl, and the softened glass member 9 is spread along the side surface of the roughened lead terminal 6 so that the glass member The exposed surface of 9 can be inclined to the lead terminal 6 in a distorted state. In particular, stress is concentrated on the glass member 9 because the side surface of the lead terminal 6 having a short side, that is, two side surfaces provided in a direction orthogonal to the longitudinal direction of the fixing member 7 are roughened. The corners of the lead terminals 6 that are easy to coat can be coated with a part of the glass member 9. By doing in this way, it can reduce that a crack generate | occur | produces in the glass member 9 in the location where the stress of the lead terminal 6 tends to concentrate. In particular, the roughened side surface of the lead terminal 6 and the non-roughened side surface of the lead terminal 6 are alternately arranged in the four side surfaces, so that the surface of the glass member 9 is disposed on both side surfaces. It can be formed to be pulled up from. By increasing the area where the surface of the lead terminal 6 alternately adheres a part of the glass member 9, the stress of the glass member 9 is reduced while reducing the stress caused by the difference in thermal expansion coefficient between the lead terminal 6 and the glass member 9. It is possible to reduce the occurrence of cracks where stress tends to concentrate.

  Furthermore, the element storage package 2 according to the present embodiment is provided with the fixing member 7 along with the thermal expansion and contraction in the longitudinal direction of the fixing member 7 during the manufacturing process of the element storage package 2 and the operation of the mounting structure 1. The stress generated at the joint between the side surface of the lead terminal 6 provided in the direction orthogonal to the longitudinal direction of the glass member 9 and the glass member 9 can be dispersed by the above configuration.

  The present invention is not limited to the above-described embodiments, and various changes and improvements can be made without departing from the scope of the present invention. For example, a paste-like glass bonding material is directly applied along the side surface of the lead terminal 6 provided in a direction orthogonal to the longitudinal direction of the fixing member 7 from the glass bonding material 9 and is cured, so that the fixing member 7 extends in the longitudinal direction. You may provide the glass member 9 in the side surface of the lead terminal 6 provided in the orthogonal direction.

DESCRIPTION OF SYMBOLS 1 Mounting structure 2 Element storage package 3 Element 4 Board | substrate 5 Metal frame 51 Frame-shaped part 6 Lead terminal 7 Fixing member 8 Input / output terminal 9 Glass member 10 Fiber attachment part 11 Connector member 12 Lid R Mounting area H Through-hole Hl Lead through hole P part

Claims (5)

A substrate having a mounting area for mounting elements on the upper surface;
A metal frame that surrounds the mounting region on the substrate and has a through-hole penetrating in a planar direction along the upper surface;
An input / output terminal having a lead terminal and a fixing member for fixing the lead terminal provided in the through hole;
The fixing member has a lead through hole, and a glass member is provided in the lead through hole.
The package for storing elements, wherein the lead terminal penetrates the glass member and protrudes from the surface of the portion at a portion protruding from the glass member. The device storage package according to claim 1,
The lead terminal has a rectangular cross section and an outer shape formed in a rod shape, and two of the four side surfaces are rougher than the remaining two side surfaces. For package. The element storage package according to claim 2,
A device housing package, wherein a part of the glass member is attached to a roughened side surface of the lead terminal. The element storage package according to claim 2 or 3,
The element storage package, wherein the roughened side surface of the lead terminal and the non-roughened side surface of the lead terminal are alternately arranged in four side surfaces. The element storage package according to any one of claims 1 to 4,
A mounting structure including an element mounted in the mounting region in the element storage package.

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