JP2003068954A - Package for storing semiconductor elements - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To effectively dissipate heat generated when a semiconductor element operates into the atmosphere. SOLUTION: A heat dissipating component 3 comprising a matrix 4 of tungsten and copper and having a mounting portion on which a semiconductor element 7 is bonded and mounted at the center of the upper surface, and a mounting portion surrounding the mounting portion on the upper surface of the heat dissipating component 3 is attached. Insulating frame 1 having a plurality of wiring conductors 11 led out to the outer surface from around the mounting portion
And a lid 2 attached to the upper surface of the insulating frame 1.
The heat radiating component 3 is a semiconductor element in which a plurality of penetrating metal members 5 made of copper are buried from a mounting portion to a lower surface, and a copper plate 6 is bonded to at least upper and lower surfaces of a portion where the penetrating metal members are buried. It is a package for storage. The heat conduction of the heat radiating component 3 is good and the contact surface with the semiconductor element 7 can be made smooth, so that the heat generated by the semiconductor element 7 can be satisfactorily radiated to the outside or the atmosphere.

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat dissipation structure for a package for housing a semiconductor device. 2. Description of the Related Art Conventionally, a package for accommodating a semiconductor element for accommodating a semiconductor element is generally made of an electrically insulating material such as an aluminum oxide sintered body, a mullite sintered body, and a glass ceramic sintered body. An insulating base and a heat-dissipating component made of a composite material of copper and tungsten or a composite material of copper and molybdenum for dissipating heat generated during operation of the semiconductor element to the outside or the atmosphere in a good manner. An insulating base is arranged so as to surround the semiconductor element mounting portion of the above, and metal powder such as tungsten, molybdenum, manganese, copper, silver, etc., which is attached and derived from the concave portion formed by the insulating base and the heat radiating component to the outer surface Composed of a plurality of wiring conductors, and a lid, and a semiconductor element on the upper surface of the heat radiating component, which is made of an adhesive such as glass, resin, brazing material, or the like. Each electrode of the semiconductor element is electrically connected to a wiring conductor via a bonding wire, and then a sealing member made of glass, resin, brazing material, or the like is placed on the insulating base. The semiconductor device is formed as a product by housing the semiconductor element inside a container including the insulating base, the heat dissipating component, and the lid. This semiconductor device may be mounted on an external heat radiating plate by screwing or the like in order to further improve the heat radiation efficiency. A semiconductor device housing package having such a heat dissipating component made of a composite material of tungsten and copper has a high heat conductivity of the heat dissipating component and a thermal expansion coefficient of the heat dissipating component which is a constituent material of the semiconductor device. Since thermal expansion is similar to that of certain silicon gallium arsenide and ceramic materials used as package materials, power ICs
Attention has been paid to a semiconductor element housing package on which a high heat generation semiconductor element such as a high frequency transistor or the like is mounted. [0004] In recent years, due to an increase in the amount of heat generated due to the high integration of power ICs and high-frequency transistors, heat dissipation components having a heat conductivity of 300 W / mK or more are now required. . However, the thermal conductivity of the above-mentioned heat dissipating component made of the composite material of tungsten and copper has a thermal conductivity of 200.
Since it is as low as about W / mK, there is a problem that heat radiation characteristics are becoming insufficient. On the other hand, it has been proposed to use a heat radiating component made of a composite material in which tungsten and copper are arranged in a matrix. In order to efficiently dissipate the heat generated during operation of the semiconductor element to the outside or the atmosphere, not only the heat conductivity of the heat dissipating component is high, but also the surface of the junction surface of the heat dissipating component with the semiconductor element. It is important that the roughness is small. If this surface roughness is large, the semiconductor element should be made of glass, resin,
When bonding and fixing via an adhesive such as brazing material, voids may be generated in the adhesive, and the voids generated in the adhesive not only reduce the bonding strength between the semiconductor element and the heat dissipation component, In addition, heat transfer between the semiconductor element and the heat dissipating component is hindered, and the heat dissipating and dissipating properties of the semiconductor package are reduced. Further, when the semiconductor package is fixed to the external heat radiating plate by screwing or the like, it is also important that the surface roughness of the surface of the heat radiating component that contacts the external heat radiating plate is small. When the surface roughness of the surface of the heat dissipating component that contacts the external heat dissipating plate is large, the contact between the heat dissipating component and the external heat dissipating plate becomes insufficient, and the heat dissipating property is reduced. Therefore, in order to obtain sufficient heat dissipation from the heat dissipating component, the surface roughness of the semiconductor element mounting surface of the heat dissipating component and the contact surface with the external heat dissipating plate should preferably be Ra ≦ 30 μm in arithmetic average roughness Ra. There is. On the other hand, in a heat dissipating component made of a composite material in which tungsten and copper are formed in a matrix, the surface roughness of the semiconductor element mounting surface of the heat dissipating component and the contact surface with the external heat dissipating plate are Ra ≦ 30 μm. Since it is difficult, it is generally practiced that the surface roughness of the semiconductor element mounting surface of the heat radiating component and the contact surface with the external heat radiating plate is Ra ≦ 30 μm by polishing the heat radiating component. In this case, although the difference between the hardness of tungsten (Vickers hardness 400) and the hardness of copper (Vickers hardness 80) is large, the fine copper portion and the tungsten portion form a matrix. The polishing rates of the tungsten portion and the copper portion are substantially the same, and no step is formed between the tungsten portion and the copper portion. However, in a semiconductor element housing package using a heat radiating component made of the composite material, tungsten has a low thermal conductivity and a low thermal expansion coefficient, and copper has a high thermal conductivity and a high thermal expansion coefficient. Can increase both the thermal conductivity and the thermal expansion coefficient of the heat dissipating component as the content of copper increases, but if the copper content is increased to improve the thermal conductivity, the heat dissipation of the semiconductor element and the heat dissipating component will increase. There is a problem that the difference between the expansion coefficients becomes large and the semiconductor element cannot be firmly joined to the heat radiating component. The present invention has been devised in view of the above-mentioned conventional problems, and has as its object to dissipate heat generated by a semiconductor element to the outside or the atmosphere, and to dissipate the semiconductor element to a heat radiating component. An object of the present invention is to provide a package for housing a semiconductor element which can be firmly bonded to a semiconductor device. A package for housing a semiconductor element according to the present invention is made of a matrix of tungsten, molybdenum, and copper, and has a mounting portion on which a semiconductor element is bonded and mounted at a central portion of an upper surface. A heat dissipating component, an insulating frame having a plurality of wiring conductors attached to the upper surface of the heat dissipating component so as to surround the mounting portion and extending from the periphery of the mounting portion to the outer surface, and an upper surface of the insulating frame. A semiconductor device housing package comprising a lid attached to cover the mounting portion, wherein the heat radiating component has a plurality of penetrating metal members made of copper buried from the mounting portion to a lower surface. In addition, a copper plate is joined to at least the upper and lower surfaces of the portion where the penetrating metal body is embedded. According to the semiconductor element housing package of the present invention, a plurality of penetrating metal members made of copper penetrating from the upper mounting portion of the semiconductor element to the lower surface are formed in the mounting portion of the semiconductor element of the heat radiation component. The heat generated by the semiconductor element can be mounted on the semiconductor element because a higher heat conducting part consisting of more copper can be arranged in the lower part of the semiconductor element as compared with a heat dissipating part formed only by a matrix of tungsten and copper. More heat can be transmitted in a direction perpendicular to the plane, and as a result, heat generated in the semiconductor element can be satisfactorily dissipated into the atmosphere through the heat radiating component. Further, since the copper plate is joined to the upper and lower surfaces of at least a plurality of penetrating metal bodies in the heat dissipating component, the contact surface of the heat dissipating component with the semiconductor element mounting surface and the external heat dissipating plate is reduced. When polishing this heat radiating component for smoothing, the copper plate on the upper and lower surfaces to be polished, or the matrix portion and the copper plate when the matrix of tungsten or molybdenum and copper is exposed around it, Since the polishing is performed, irregularities generated by polishing the tungsten or molybdenum / copper matrix and the through metal body made of copper due to the difference in hardness between the matrix and the through metal body can be prevented. The radiator plate can be thermally connected well, and the heat generated by the semiconductor element is transferred to the air through this radiator. Others can be satisfactorily dissipated to the external radiator plate. Further, a plurality of penetrating metal bodies made of copper penetrating from the mounting portion of the semiconductor element on the upper surface to the lower surface embedded in the mounting portion of the semiconductor device of the heat radiating component, and a copper plate bonded to the upper and lower surfaces of the heat radiating component. By the direct joining, the transfer of heat generated in the semiconductor element in the heat radiating component becomes extremely good. As a result, it is possible to operate the semiconductor element normally and stably for a long period of time. Next, the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a sectional view showing an embodiment of a package for housing a semiconductor element according to the present invention, wherein 1 is an insulating frame, 2 is a lid, and 3 is a heat dissipating component. The insulating frame 1, the lid 2, and the heat dissipating component 3 constitute a semiconductor element housing package 8 for housing the semiconductor element 7. The insulating frame 1 is made of an aluminum oxide sintered body.
It is made of a mullite sintered body, a glass ceramic sintered body, or the like, and is bonded and fixed to the heat radiating component 3 via the brazing material 9. At the time of bonding and fixing with the brazing material 9, usually, a metal layer for brazing (not shown) includes the insulating frame 1 and the heat radiating component 3.
Formed at the junction with A semiconductor element 7 is fixed to a mounting portion at the center of the upper surface of the heat radiating component 3 via an adhesive 10 such as resin, glass, brazing material or the like. In the case where a brazing material is used as the adhesive 10, a metal layer (not shown) for brazing is usually formed at a bonding portion between the heat dissipation component 3 and the semiconductor element 7. However, when sufficient brazing can be performed by the copper plate 6 joined to the mounting portion on the upper surface of the heat radiation component 3, the brazing metal layer is not particularly necessary. If the insulating frame 1 is made of, for example, an aluminum oxide-based sintered body, an organic binder, a solvent, a plasticizer, an organic binder, a solvent suitable for a raw material powder of aluminum oxide, silicon oxide, magnesium oxide, calcium oxide, etc. A dispersing agent is mixed and added to form a ceramic, and this is formed into a ceramic green sheet (ceramic green sheet) by employing a conventionally known doctor blade method or calender roll method. A suitable punching process is performed on the sheet, and a conductive paste made by mixing a suitable organic binder and a solvent with a metal material powder such as tungsten, molybdenum, manganese, copper, silver, nickel, palladium, gold, etc. is previously formed on the green sheet. After printing and applying in a predetermined pattern by screen printing etc., this green The over preparative laminating a plurality, is produced by firing at a temperature of about 1600 ° C.. Further, a wiring conductor 11 is formed on the insulating frame 1 so as to extend from the concave portion 1 a formed by the insulating frame 1 and the heat radiating component 3 to the outer surface of the insulating frame 1. Each electrode of the semiconductor element 7 is electrically connected to one end of the semiconductor element 7 via a bonding wire 12. The wiring conductor 11 is made of a metal having a high melting point such as tungsten and molybdenum. A metal paste obtained by adding an appropriate organic binder and a solvent to a metal powder such as tungsten and molybdenum is mixed with a ceramic for forming the insulating frame 1. By printing and applying a predetermined pattern on the green sheet in advance by a conventionally known screen printing method, the green sheet is adhered and formed from the concave portion 1a of the insulating frame 1 and the heat radiating component 3 to the outer surface of the insulating frame 1. The exposed surface of the wiring conductor 11 is excellent in corrosion resistance of nickel, gold, etc.
When a metal having excellent bonding properties of 12 is applied to a thickness of 1 to 20 μm by plating, oxidation corrosion of the wiring conductor 11 can be effectively prevented and the connection of the bonding wire 12 to the wiring conductor 11 is firmly made. be able to. Accordingly, the wiring conductor 11 is made of a metal having excellent corrosion resistance and excellent bonding properties such as nickel and gold on the exposed surface.
It is desirable to apply it to a thickness of about 20 μm. The heat dissipating component 3 has a function of absorbing heat generated by the operation of the semiconductor element 7 and dissipating it into the atmosphere. For example, a tungsten powder or a molybdenum powder having an average particle size of 5 to 40 μm can be used. 7 is press-formed so that a plurality of through holes are formed in the mounting portion.
By sintering in an atmosphere of 00-1600 ° C, 10-50% by weight
A porous body having a plurality of through holes in the mounting portion of the semiconductor element 7 which can be impregnated with copper is prepared in advance, and the porous body is impregnated with copper at about 1200 ° C. under a hydrogen atmosphere to obtain tungsten or molybdenum and The copper matrix 4 and the penetrating metal members 5 are formed, and thereafter, a copper foil as a copper plate 6 is bonded to the upper and lower surfaces of the matrix 4 where at least the plurality of penetrating metal members 5 are embedded by thermocompression bonding. In this example, an example is shown in which a copper plate 6 is bonded to the entire upper and lower surfaces of the matrix 4. Further, the upper and lower surfaces of the heat radiating component 3 are polished so that the surface roughness is Ra ≦ 30 μm. If the thickness of the copper plate 6 is more than 800 μm, the stress generated due to the difference in thermal expansion between the matrix 4 and the copper plate 6 during thermocompression bonding of the copper plate 6 tends to increase, and sufficient bonding strength tends not to be obtained. Therefore, it is desirable to set the thickness to 800 μm or less. If the thickness of the copper plate 6 is 50 μm or more, the heat generated by the operation of the semiconductor element 7 is
, The heat dissipating properties of the heat dissipating component 3 are further improved. The material of the copper plate 6 joined to the upper and lower surfaces of the heat radiating component 3 is not limited to pure copper, but has a good thermal conductivity and a sufficient joint strength with the matrix 4 of tungsten or molybdenum and copper. If you can
Various copper alloys containing copper as a main component may be used. This is the same for the through metal body 5 made of copper. The copper plate 6 bonded to the upper and lower surfaces of the heat radiating component 3 is connected to the upper and lower surfaces of at least a portion where the plurality of penetrating metal members 5 are buried, for example, the mounting portion of the semiconductor element 7 and the external heat radiating plate. It is sufficient if it is formed in the portion, and it is not always necessary to cover the entire upper and lower surfaces of the heat radiation component 3. Thus, according to the semiconductor element housing package 8 described above, the semiconductor element 7
Is bonded and fixed via an adhesive 10 made of glass, resin, brazing material or the like, and each electrode of the semiconductor element 7 is connected to a predetermined wiring conductor 11 via a bonding wire 12. The lid 2 is joined to the upper surface via a sealing material made of glass, resin, brazing material, or the like, and the semiconductor element 7 is hermetically accommodated in the recess 1 a formed by the insulating frame 1 and the heat radiating component 3. It becomes a semiconductor device as a product. In the package 8 for accommodating the semiconductor element of the present invention, the radiation element 3 is connected to a radiation fin, or the radiation element 3 and the radiation fin are integrated, so that the semiconductor element 7 can be operated. The function of absorbing the generated heat by the heat radiating component 3 and dissipating it into the atmosphere can be further improved. Next, in order to confirm the influence of the surface roughness of the heat radiating member 3 on the heat radiating characteristics of the semiconductor device housing package, test samples were prepared and the heat radiating characteristics were evaluated. The test sample is 23 mm × 23 m at the center.
An insulating frame 1 made of a 45 mm × 45 mm × 3 mmt aluminum oxide sintered body having a through-hole of “m” formed thereon is surrounded by a semiconductor element mounting portion, and is then 35 mm × 35 mm ×
It was joined to the heat dissipating component 3 of 2 mmt. The insulating frame 1 and the heat dissipating component 3 were joined by melting a brazing material 9 composed of 72% by weight of silver / 28% by weight of copper at about 700 ° C. in a reducing atmosphere and then cooling and solidifying. The heat dissipating component 3 is formed by pressing a tungsten powder into a predetermined shape and then firing in a reducing atmosphere at about 1000 ° C. to form a tungsten porous body. Then, the tungsten porous body is impregnated with copper. It was produced by joining a copper plate 6 to the lower surface by thermocompression bonding. At this time, in order to confirm the influence of the surface roughness (Ra) on the heat dissipation, the heat radiating component 3 in which the copper plate 6 is bonded to the upper and lower surfaces by thermocompression bonding, and the heat radiating component in which the copper plate is not bonded to the upper and lower surfaces. And the upper and lower surfaces of these heat radiating components were polished to produce heat radiating components 3 having a predetermined surface roughness (Ra). The heat radiating characteristic is as follows: 10 mm × 10 mm × 0.6 m assuming the semiconductor element 7 in the center of the heat radiating component 3.
mt platinum heating element formed on the surface of the silicon substrate, the adhesive 10 made of epoxy resin
The composition was cured at 130 ° C. and adhered, and was confirmed by measuring the surface temperature of the silicon heater substrate when the silicon heater substrate was heated at 3 W in a windless state. The adhesive 10 at the portion where the silicon heater substrate was bonded was checked for the presence or absence of voids in the adhesive 10 by an ultrasonic flaw detector (manufactured by Hitachi Construction Machinery, Ltd.).
i-scope-10). Table 1 shows the results. [Table 1] Generally, a malfunction occurs when the temperature of a semiconductor element is higher than 100 ° C.
It must be kept below. As can be seen from the results shown in Table 1, by joining the copper plates 6 to the upper and lower surfaces of the heat dissipating component 3, the surface roughness of the heat dissipating component 3 can be reduced to 30 μm or less, and the heat dissipating characteristics of the semiconductor element housing package can be improved. Can be improved. On the other hand, in the heat radiating component 3 to which the copper plate 6 is not joined, unevenness is generated on the surface by polishing the matrix 4 and the penetrating metal body 5 due to a difference in hardness between the matrix 4 and the penetrating metal body 5. It was difficult to reduce the thickness to 30 μm or less. As a result, the surface temperature of the silicon heater substrate corresponding to the semiconductor element 7 could not be maintained at 100 ° C. or lower, and voids were observed in the adhesive 10 to which the silicon heater substrate was bonded. It should be noted that the present invention is not limited to the above-described embodiment, and various changes can be made without departing from the gist of the present invention. For example, in order to efficiently radiate the heat generated by the semiconductor element 7 from the heat radiating component 3 to the atmosphere, a heat radiating fin is attached to the heat radiating component 3 on the side opposite to the surface on which the semiconductor element 7 is mounted by brazing or the like. And the heat dissipating fins and the heat dissipating component 3 may be integrated. According to the semiconductor device housing package of the present invention, a plurality of penetrating metal members made of copper penetrating from the mounting portion of the semiconductor element on the upper surface to the lower surface of the semiconductor device mounting portion of the heat radiation component. Is formed, a higher heat conducting portion made of copper can be arranged at a lower portion of the semiconductor element as compared with a heat dissipating component formed only of a matrix of tungsten and copper. Can be transmitted more in the direction perpendicular to the mounting surface of the semiconductor element, and as a result, heat generated in the semiconductor element can be satisfactorily dissipated into the atmosphere via the heat radiating component. Furthermore, since the copper plate is bonded to the upper and lower surfaces of at least a plurality of penetrating metal bodies in the heat dissipating component, the contact surface of the heat dissipating component with the semiconductor element mounting surface and the external heat dissipating plate is reduced. When polishing this heat radiating component for smoothing, the copper plate on the upper and lower surfaces to be polished, or the matrix portion and the copper plate when the matrix of tungsten or molybdenum and copper is exposed around the copper plate, Since polishing is performed, unevenness caused by polishing the tungsten or molybdenum or copper matrix and the through metal body made of copper due to the difference in hardness can be prevented. The heat radiation plate can be connected well to the heat radiating plate, and the heat generated by the semiconductor element Others can be satisfactorily dissipated to the external radiator plate. Further, a plurality of penetrating metal bodies made of copper buried in the mounting portion of the semiconductor element of the heat radiating component and penetrating from the mounting portion of the semiconductor element on the upper surface to the lower surface are connected to the copper plate bonded to the upper and lower surfaces of the heat radiating component. By performing the direct bonding, the heat generated in the semiconductor element can be very effectively transferred in the heat radiating component. As a result, it is possible to operate the semiconductor element normally and stably for a long period of time. As described above, according to the present invention, a semiconductor element housing capable of dissipating the heat generated by the semiconductor element to the outside and the atmosphere satisfactorily and firmly bonding the semiconductor element to the heat radiating component. For the package can be provided.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view showing an example of an embodiment of a package for housing a semiconductor element according to the present invention. [Description of Signs] 1... Insulating frame 1a... Recess 2... Lid 3... Heat dissipating component 4... Tungsten or molybdenum and copper matrix 5 ······ Through metal body 6 ······ Copper plate 7 ···· Semiconductor element 8 ···· Package 9 for housing semiconductor element ·················· Adhesive 11 Wiring conductor 12 Bonding wire

Claims (1)

Claims: 1. A heat-dissipating component comprising a matrix of tungsten or molybdenum and copper, having a mounting portion on which a semiconductor element is bonded and mounted at a central portion of an upper surface, and a heat-radiating component on the upper surface of the heat-radiating component. An insulating frame having a plurality of wiring conductors led out from the periphery of the mounting portion to the outer surface, which is mounted around the mounting portion, and mounted on the upper surface of the insulating frame so as to cover the mounting portion; A semiconductor element housing package comprising a lid, wherein the heat radiating component has a plurality of penetrating metal members made of copper buried from the mounting portion to the lower surface, and at least these penetrating metal members are buried. A copper package is joined to upper and lower surfaces of a part where the semiconductor device is located.