JP2011192681A - Airtight terminal for optical semiconductor device, and optical semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an airtight terminal for an optical semiconductor device that efficiently dissipates heat generated as the optical semiconductor device operates to the outside by structuring a heat sink having good sealing properties with glass and high thermal conductivity, thereby having higher airtightness and productivity. <P>SOLUTION: The productivity is improved without spoiling heat dissipation and the airtightness is also enhanced by sealing a metal base 1 having a heat sink insertion hole 12 formed therein and the heat sink 4 inserted into the through hole 12 with an insulating material 3 consisting of glass, and composing the heat sink 4 with a clad material having a core 41 and an outer peripheral portion 42, wherein a side face of the heat sink 4 along the core 41 is covered with the outer peripheral portion 42 formed of second metal suitable for glass sealing in a rolled shape and the core 41 covered with the outer peripheral portion 42 is formed of first metal having superior thermal conductivity. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an airtight terminal in which a metal base and a lead terminal are hermetically sealed via an insulating material, and more specifically, an airtight terminal for an optical semiconductor device used to hermetically seal an optical semiconductor element, and The present invention relates to an optical semiconductor device using the same.

  As an original hermetic terminal for an optical semiconductor device, a lead terminal insertion hole is formed at a predetermined position of a metal base formed of Fe or an Fe alloy, and a wax such as silver wax is formed at a predetermined position of the metal base. A heat sink made of Cu or Cu alloy having a good thermal conductivity is fixed using a material, a lead terminal is inserted into a lead insertion hole provided in the metal base, and the metal base and the lead terminal are made of glass or the like. It was configured to be hermetically sealed with an insulating material serving as electrical insulation.

  FIG. 3 shows an example of the above-described hermetic terminal, where 100 is a metal base, 101 is a lead terminal insertion hole, 200 is a lead terminal, 300 is an insulating material such as glass, 400 is a heat sink, and 500 is a wax material. Show.

  As shown in FIG. 3, the original hermetic terminal has a lead terminal insertion hole 101 penetrating through the metal base 100, and a lead terminal 200 is inserted into the lead terminal insertion hole 101. Is hermetically sealed for electrical insulation through an insulating material 300 such as glass. A heat sink 400 is attached to a predetermined position in the center of the metal base 100 via a wax material 500 such as silver wax. The heat sink 400 made of Cu or Cu alloy and the insulating material 300 such as glass have poor bonding properties due to the difference in thermal expansion coefficient, and therefore the wax material 500 is used for mounting the heat sink 400.

  Such an airtight terminal is generally provided with, for example, a semiconductor element (not shown) on the side surface of the heat sink 400, and Au, Al, or the like is provided between the semiconductor element and a portion of the lead terminal 200 protruding above the metal base 100. A cylindrical metal cap 110 that is wired with a conductive wire (not shown) and has a metal base 100 and a transparent window formed of glass on the top plate portion is capped on the metal base 100, and the metal cap 110 is capped. The semiconductor element (not shown) is hermetically sealed by a method such as brazing the outer periphery of the metal base 100 with a brazing material such as silver wax or welding by electric welding.

  In an airtight terminal on which such a semiconductor element is mounted, a heat dissipation path for heat generated from an electronic component such as a semiconductor element is radiated from the heat sink to the air through the heat sink and from the metal base to which the heat sink is attached through the heat sink to the air. There are two ways to go.

  As a heat sink material for heat dissipation, Cu or Cu alloy having good thermal conductivity is used, and it is possible within the limits of design as an optical semiconductor device as a measure for more efficient heat dissipation. Although the capacity of the heat sink is increased as much as possible, the heat dissipation effect with respect to the increase in the heat generation amount of the electronic component is becoming insufficient in the tendency that the heat generation amount of the electronic component increases.

  In order to improve the heat dissipation of the hermetic terminal, it is considered that the whole including the metal base is made of Cu or Cu alloy having a good thermal conductivity. However, the metal base material is Cu or Cu alloy. In this case, since the thermal expansion coefficient of Cu or Cu alloy is larger than the thermal expansion coefficient of glass, in the furnace passing process for hermetically sealing the lead terminal through the glass in the lead insertion hole provided in the metal base, The volume change when heated / cooled becomes large, and stress may be generated on the bonding surface between the glass and the metal base to cause the bond to be peeled off. There is a problem that the metal base is remarkably lowered as compared with the case where the metal base is formed of an Fe alloy.

  For this reason, the metal base portion is made of Fe or an Fe alloy, only the heat sink is made of Cu or a Cu alloy, and these two materials are joined by a wax material such as silver wax. Therefore, the heat generated from the semiconductor element is efficiently radiated by the heat sink, but the metal base of the hermetic terminal is made of Fe, which has a lower thermal conductivity than Cu or Cu alloy. There is a problem that it is difficult to obtain a heat dissipation effect.

  In view of this, as a conventional airtight terminal that improves the heat dissipation of the airtight terminal, a heat sink insertion hole that penetrates the metal base is provided, and the heat sink penetrates there to be attached with a wax material or the like. (For example, see Patent Document 1).

FIG. 4 shows a conventional hermetic terminal described in Patent Document 1. In FIG.
4, the same components as those in FIG. 3 are denoted by the same reference numerals, and description thereof is omitted. FIG. 4 shows a conventional hermetic terminal. Reference numeral 102 denotes a heat sink insertion hole.

  The conventional airtight terminal shown in FIG. 4 is provided with a heat sink insertion hole 102 at a predetermined position of the metal base 100, and the heat sink 400 penetrates the metal base 100 through a wax material 500 such as silver wax in the heat sink insertion hole 102. It is the thing of the structure attached in the state.

  According to this, the volume of the heat sink 400 made of a metal having good thermal conductivity can be secured large, and the heat sink 400 having good thermal conductivity penetrates the inside and outside of the metal base 100. In dissipating the heat generated from the parts, an efficient heat dissipation path from the lower surface of the metal base 100 could be realized without being obstructed by Fe or Fe alloy constituting the metal base 100.

JP-A-6-302912

  However, in the case of manufacturing an airtight terminal having the conventional configuration, there is a problem in productivity. More specifically, when the lead terminal is hermetically sealed through the glass in the lead terminal insertion hole provided in the metal base, the tablet and the lead terminal in which glass powder is sintered in the lead insertion hole of the metal base are assembled. The lead terminal was hermetically sealed to the metal base through the glass by passing through a high temperature furnace in a state and melting the glass. Further, in the process of attaching the heat sink to the metal base via the wax material, the same high temperature furnace is passed through, but the melting temperature of the glass and the melting temperature of the wax material are different temperature ranges. For this reason, there is a need for two furnace passing steps at different temperature ranges, and there is a problem that productivity is poor because it is necessary to perform the assembly step twice in accordance with this.

  Therefore, there has been a method in which a heat sink formed of Cu or Cu alloy is plated with Fe or Fe alloy and then glass sealed to a metal base. However, in a normal plating process, the thickness is several μm to several Since only about 10 μm can be secured, with this thickness of Fe or Fe alloy plating, the volume change of the entire heat sink during heating and cooling in the furnace passing process is the case of a heat sink formed only of Cu or Cu alloy. Since there was almost no change, the heat sink caused a larger volume change than glass during heating and cooling, and stress was generated on the joint surface between the heat sink and the glass, possibly causing cracks and debonding. That is, in the plating process, the airtightness and the bonding strength when the heat sink is hermetically sealed using glass could hardly be increased.

  In addition, in the plating process, the bond between the bare metal and the plated metal often becomes a weak bond only by van der Waals force, so stress is generated on the joint surface during heating and cooling in the furnace passing process. In addition, the bond between the Cu or Cu alloy bare metal and the Fe or Fe alloy plated metal may be peeled off.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an airtight terminal for an optical semiconductor device having high productivity and high airtightness.

  In order to solve the above-described conventional problems, in the hermetic terminal for an optical semiconductor device of the present invention, a lead terminal insertion hole and a heat sink insertion hole penetrating in and out are formed in a metal base, and the lead terminal insertion hole has a lead. An optical semiconductor device in which the lead terminal and the heat sink are sealed with an insulating material made of glass with respect to the metal base with a terminal inserted and a heat sink made of metal inserted into the heat sink insertion hole In the airtight terminal for use, the heat sink is a clad material having an axial core made of a first metal material and an outer peripheral portion made of a second metal material covering an outer peripheral side surface of the axial core, and the outer peripheral portion is The thermal expansion coefficient of the second metal material formed is closer to the thermal expansion coefficient of the insulating material made of glass than the thermal expansion coefficient of the first metal material forming the shaft core. To.

Moreover, the thickness of the outer peripheral part which consists of a 2nd metal material is 25% or more of the thickness of the axial center which consists of a 1st metal material, It is characterized by the above-mentioned.
Further, the first metal material is made of Cu or an alloy thereof, and the second metal material is Fe or Ni, or Fe-25 to 35Ni-15 to 25Co alloy, 15 to 30Cr—Fe alloy, Fe-40 to 55Ni-3. It is any one of -8Cr alloy.

  As described above, according to the hermetic terminal for an optical semiconductor device of the present invention, it is possible to obtain a heat dissipation property that makes full use of the thermal conductivity of the first metal material that forms the shaft core, and the hermetic terminal for an optical semiconductor device. Can be produced efficiently.

Sectional drawing of the airtight terminal for optical semiconductor devices in embodiment of this invention Sectional drawing which shows the example of a change in embodiment of this invention Cross section of original airtight terminal Cross section of conventional airtight terminal

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a cross-sectional view of an airtight terminal for an optical semiconductor device in an embodiment of the present invention. In FIG. 1, 1 is a metal base, 2 is a lead terminal, 3 is an insulating material, 4 is a heat sink, 11 is a lead terminal insertion hole, 12 is a heat sink insertion hole, 41 is an axial core formed of a first metal material, Reference numeral 42 denotes an outer peripheral portion formed of a second metal material, and 5 denotes a metal cap for capping the metal base 1.

  The airtight terminal for an optical semiconductor device shown in FIG. 1 has a lead terminal insertion hole 11 and a heat sink insertion hole 12 penetrating the metal base 1, and a lead terminal 2 is formed in the lead terminal insertion hole 11 and a heat sink insertion hole 12. Each of the heat sinks 4 is inserted, and the lead terminal 2 and the heat sink 4 are hermetically sealed to the metal base 1 by an insulating material 3 made of glass.

Further, an element mounting portion (not shown) for mounting an optical semiconductor element (not shown) is formed on the side surface of the heat sink 4.
The heat sink 4 is formed of a shaft core 41 and an outer peripheral portion 42, and the outer peripheral portion 42 covers a side surface along the shaft core 41 in a roll shape and is formed of a second metal material. As this second metal material, Fe or Ni or an alloy containing them can be used. As a specific example, any of Kovar alloy (Fe-25 to 35Ni-15 to 25Co), 15 to 30Cr—Fe alloy, and Fe-40 to 55Ni-3 to 8Cr alloy can be used.

  The shaft core 41 covered with the outer peripheral portion 42 formed of the second metal material is made of the first metal material having a high thermal conductivity. As a specific example, Cu or an alloy thereof can be used.

  The heat sink is a columnar material having a through-hole in the central portion (outer peripheral portion), and a cylindrical material (axial core) made of the first metal is press-fitted into the cylindrical material (outer peripheral portion). It is made of a clad material that is bonded between metals by processing. The shape of the shaft core and the outer peripheral portion is not limited to a cylindrical shape as long as it can be configured as a cladding material, and may be a polygonal column shape, for example.

  Such an airtight terminal for an optical semiconductor device can be manufactured by an easy method. That is, when the lead terminal 11 and the heat sink 4 are hermetically sealed with the insulating material 3 made of glass in each of the lead terminal insertion hole 11 and the heat sink insertion hole 12 provided in the metal base 1, the lead insertion of the metal base 1 is performed. Each of the hole 11 and the heat sink insertion hole 12 is passed through a high-temperature furnace in a state where the tablet, the lead terminal 11 and the heat sink 4 are sintered, and the glass base is melted to the metal base 1. The lead terminal 11 and the heat sink 4 are hermetically sealed with an insulating material 3 made of glass.

  In the furnace passing process, the entire hermetic terminal is heated to about 500 to 1000 ° C., so that the glass is melted and then cooled to room temperature, and the glass is solidified to be sealed. At this time, the heat sink 4 is also heated and cooled, and a volume change occurs in the heat sink 4. The volume change of the heat sink 4 depends on both the volume change of the shaft core 41 and the volume change of the outer peripheral portion 42.

  Here, in this invention, the clad material which consists of a 1st, 2nd metal material is used as the heat sink 4, and a metal with high heat conductivity is used as the 1st metal material which makes the axial core 41, The outer peripheral part As the second metal material forming 42, a metal having a thermal expansion coefficient close to that of the insulating material 3 made of glass is used. Even if the first metal material forming the shaft core 41 undergoes a large volume change during heating and cooling in the furnace passing process, the volume change of the second metal material forming the outer peripheral portion 42 is larger as the first metal material. Does not cause. Therefore, the larger the thickness of the outer peripheral portion 42, the smaller the volume change with respect to the temperature change of the entire heat sink.

  And if it is a clad material, the thermal expansion coefficient of the 2nd metal material which forms the outer peripheral part 42 about the thickness change of the outer peripheral part 42 formed with a 2nd metal material about the volume change of the heat sink 4 whole with respect to a temperature change. Can be dominant. Here, the ratio between the shaft core 41 and the outer peripheral portion 42 in which the thermal expansion coefficient of the second metal material forming the outer peripheral portion 42 is dominant is such that the thickness of the outer peripheral portion 42 is 25 with respect to the thickness of the shaft core 41. For example, if the thickness of the shaft core 41 made of the first metal material is 1.0 mm, the thickness of the outer peripheral portion 42 made of the second metal material is preferably 250 μm or more. Here, the thickness of the shaft core is the length of the longest portion in the cross section orthogonal to the axial direction of the shaft core, for example, the diameter if the shaft core is cylindrical, and the length of the diagonal line if it is a quadrangular prism. is there.

  Therefore, the volume change of the entire heat sink 4 at the time of heating / cooling can be made the same level as that of the insulating material 3 made of glass, and stress due to thermal expansion and contraction can be hardly generated on the joint surface between the insulating material 3 and the heat sink 4. 1 and the insulating material 3 made of glass are not cracked, and the bond between the heat sink 4 and the insulating material 3 made of glass is difficult to peel off, so that airtightness can be ensured.

  Further, the clad material constituting the heat sink 4 is securely metal-bonded between the shaft core 41 formed of the first metal material and the outer peripheral portion 42 formed of the second metal material. Therefore, even if a stress due to thermal expansion and contraction occurs between the shaft core 41 and the outer peripheral portion 42 during heating and cooling in the furnace passing process, the shaft core 41 and the outer peripheral portion 42 are coupled with a stronger binding force than this stress. Therefore, there is no possibility that the shaft core 41 and the outer peripheral portion 42 are peeled off as in the case of using a heat sink in which a plated metal layer of Fe or Fe alloy is formed on a Cu alloy ingot by plating. .

  Furthermore, since the side surface along the shaft core 41 of the heat sink 4 is covered with the outer peripheral portion 42 formed of the second metal material, good sealing with the insulating material 3 made of glass is obtained, and high airtightness is achieved. The shaft core 41 covered with the outer peripheral portion 42 of the heat sink 4 is formed of a first metal material having a high thermal conductivity, and the first and second regions inside and outside the region covered with the metal cap 5 are formed. Since the shaft core 41 made of a metal material is penetrated, the heat dissipation by the thermal conductivity of the first metal material made of Cu or Cu alloy can be obtained as in the prior art, and the element mounting portion It is possible to efficiently dissipate heat generated by an optical semiconductor element (not shown) mounted on the optical semiconductor device, and it can be applied to an optical semiconductor device with higher output and brightness.

  Further, since the side surface along the axis 41 of the heat sink 4 is covered with the outer peripheral portion 42 formed of the second metal material having a thermal expansion coefficient close to that of the insulating material 3 made of glass, a good sealing with the glass is achieved. It is possible to seal the lead terminal 2 and the heat sink 4 to the metal base 1 with an insulating material 3 made of glass. The lead terminal 2 and the heat sink can be attached to the metal base 1 in a single furnace passing process. Since 4 can be attached, it becomes possible to realize high productivity.

  In the present embodiment, a flat terminal is used as the metal base 1, and a lead terminal inserted into the lead terminal insertion hole 11 through an insulating material 3 made of glass in a through hole provided in the metal base 1. 2 and the heat sink 4 inserted through the heat sink insertion hole 12 have been described as being sealed. However, the present invention is not limited to this, and the metal base 1 has a collar as in the modified embodiment shown in FIG. A cylindrical one is used, and a lead terminal insertion hole 11 and a heat sink insertion hole 12 are provided in the top plate portion 14 of the cylindrical metal base 1 with a collar, and the lead terminal insertion hole 11 and the heat sink insertion hole 12 are respectively lead. Insulation made of glass in the region surrounded by the side wall portion 13 and the metal base top plate portion 14 of the metal base 1 through the terminals 2 and the heat sink 4. 3 or as sealing the heat sink 4 is inserted into the lead terminal lead terminals 2 and the heat sink insertion hole 12 is inserted into the insertion hole 11 meets.

  Furthermore, by adjusting the wire diameter of the lead terminal 2 and the hole diameter of the lead terminal insertion hole 11 and shortening the length of the lead terminal 2 protruding from the bottom surface of the metal base 1, it may be a surface mount type.

  It is useful as an airtight terminal used in an optical semiconductor device, and is particularly suitable for an optical semiconductor device with high output and high luminance.

DESCRIPTION OF SYMBOLS 1,100 Metal base 2,200 Lead terminal 3,300 Insulation material 4,400 Heat sink 500 Brazing material 11,101 Lead terminal insertion hole 12,102 Heat sink insertion hole 13 Cylindrical part 14 Metal base top plate part 41 Core 42 Outer part

Claims (4)

A lead terminal insertion hole and a heat sink insertion hole penetrating inside and outside are formed in the metal base, a lead terminal is inserted into the lead terminal insertion hole, and a heat sink made of metal is inserted into the heat sink insertion hole, In the airtight terminal for an optical semiconductor device formed by sealing the lead terminal and the heat sink with an insulating material made of glass with respect to the metal base,
The heat sink is a clad material having an axial core made of a first metal material and an outer peripheral portion made of a second metal material covering an outer peripheral side surface of the axial core,
A light whose thermal expansion coefficient of the second metal material forming the outer peripheral portion is closer to the thermal expansion coefficient of the insulating material made of glass than the thermal expansion coefficient of the first metal material forming the shaft core. Airtight terminal for semiconductor devices. 2. The hermetic terminal for an optical semiconductor device according to claim 1, wherein the thickness of the outer peripheral portion made of the second metal material is 25% or more of the thickness of the shaft core made of the first metal material. The first metal material is made of Cu or an alloy thereof,
The second metal material is Fe, Ni, or an Fe-25-35Ni-15-25Co alloy, 15-30Cr-Fe alloy, or Fe-40-55Ni-3-8Cr alloy. An airtight terminal for an optical semiconductor device according to any one of 1 and 2.   An optical semiconductor device comprising the hermetic terminal for an optical semiconductor device according to claim 1.

Images