JP6983119B2 - Heat dissipation plate, semiconductor package and semiconductor device - Google Patents

Description

The present invention relates to a heat dissipation plate including a copper plate or the like, a semiconductor package, and a semiconductor device.

A semiconductor element such as a semiconductor integrated circuit element is mounted on a semiconductor package including a mounting portion of the semiconductor element, and is mounted on various electronic devices such as a communication device and a computer. In the semiconductor package, a heat radiating plate for dissipating heat generated when the semiconductor element is operated may be used as a component. As the heat radiating plate, a plate having a metal plate such as copper is known (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2002-93931

In recent years, with the increasing functionality of semiconductor devices, the amount of heat generated during operation of semiconductor devices tends to increase. Therefore, it is required to improve the heat dissipation property, that is, the thermal conductivity of the heat dissipation plate. In order to improve heat dissipation, it is also required to reduce the possibility of various defects caused by stress such as thermal stress due to the difference in the coefficient of thermal expansion between the heat dissipation plate and the insulator to which the heat dissipation plate is joined.

The heat dissipation plate of one aspect of the present invention is made of a metal material containing copper as a main component, and is composed of a flat plate having an upper surface including a mounting portion of a semiconductor element and a metal material containing an iron-nickel-cobalt alloy as a main component. It is located around the flat plate in a plan view, and includes a frame-shaped plate having an inner side surface joined to the outer surface of the flat plate. Further, in a plan view, the dimension between the inner surface of the frame-shaped plate and the outer surface facing the inner surface is the same as that of the inner surface of the frame-shaped plate and the other inner surface facing the inner surface. 7.5% or more of the size of the flat plate located between them, and 0.3 mm or less subtracted from the distance between the outer surface facing the inner side surface and the outer peripheral position of the mounting portion adjacent to the inner side surface. Is.

The semiconductor package of one aspect of the present invention includes a heat radiating plate having the above configuration and an insulating frame body located on the heat radiating plate and having a lower surface joined to the upper surface of the frame-shaped plate.

The semiconductor device according to one aspect of the present invention includes a semiconductor package having the above configuration and a semiconductor element mounted on the mounting portion.

Since the semiconductor package of one aspect of the present invention includes the flat plate and the frame-shaped plate having the above-mentioned configuration, it is possible to provide a heat radiating plate effective for improving heat dissipation and reducing warpage in the semiconductor package.

Since the semiconductor package of one aspect of the present invention includes the heat radiating plate having the above configuration, it is possible to provide a semiconductor package effective for improving heat radiating property and reducing warpage and the like.

Since the semiconductor device according to one aspect of the present invention includes the semiconductor package having the above configuration, it is possible to provide a semiconductor device having high long-term reliability, which is effective for improving heat dissipation and reducing warpage.

(A) is a top view showing the heat radiation plate of the embodiment of the present invention, and (b) is a sectional view taken along the line AA of (a). (A) is a top view showing another example of the heat radiation plate of the embodiment of the present invention, and (b) is a sectional view taken along the line BB of (a). It is a perspective view of the heat dissipation plate shown in FIG. It is a perspective view which looked at the semiconductor package of embodiment of this invention from the upper side. (A) is a top view of the semiconductor package shown in FIG. 4, (b) is a cross-sectional view taken along the line CC of (a), and (c) is a bottom view. (A) is a perspective view of the semiconductor package shown in FIG. 5 as viewed from above, and (b) is a perspective view showing a modified example of (a). It is a top view which shows the semiconductor device of embodiment of this invention. It is a top view which shows the other example of the semiconductor device of embodiment of this invention.

The radiator plate, semiconductor package and semiconductor device according to the embodiment of the present invention will be described with reference to the accompanying drawings. It should be noted that the distinction between the upper and lower parts in the following description is for convenience of explanation, and does not limit the upper and lower parts when the heat dissipation plate, the semiconductor package or the semiconductor device is actually used. Further, various thermal conductivitys in the following description are values at room temperature to about 200. This thermal conductivity can be measured by, for example, various measuring devices by a stationary method or a non-stationary method.

1 (a) is a top view showing a heat radiation plate according to an embodiment of the present invention, and FIG. 1 (b) is a cross-sectional view taken along the line AA of FIG. 1 (a). FIG. 2A is a top view showing another example of the heat dissipation plate according to the embodiment of the present invention, and FIG. 2B is a cross-sectional view taken along the line BB of FIG. 2A. FIG. 3 is a perspective view of the heat dissipation plate shown in FIG. FIG. 4 is a perspective view of the semiconductor package according to the embodiment of the present invention as viewed from above, and includes a heat dissipation plate as shown in FIG. 5 (a) is a top view of the semiconductor package shown in FIG. 4, FIG. 5 (b) is a cross-sectional view taken along the line CC of FIG. 5 (a), and FIG. 5 (c) is a bottom view. be. 6 (a) is a perspective view of the semiconductor package shown in FIG. 5 as viewed from above, and FIG. 6 (b) is a perspective view showing a modified example of FIG. 6 (a). FIG. 7 is a top view showing the semiconductor device according to the embodiment of the present invention, and includes a semiconductor package as shown in FIG. 5 or FIG. An insulating frame made of a ceramic material or the like is joined to the heat radiating plate 10 to form a semiconductor package, and a semiconductor element is mounted on the semiconductor package to form a semiconductor device. In each of the above drawings, even those that are not cross-sectional views are partially hatched for easy viewing.

The heat radiating plate 10 has a flat plate 1 having a square shape or the like (square shape in the example of FIG. 1), and a frame-shaped plate 2 located surrounding the flat plate 1 in a plan view. In the examples shown in FIGS. 1 and 2, the frame-shaped plate 2 has a square frame shape (square frame shape in the example of FIG. 1), and the flat plate 1 is exactly contained in the frame of the frame-shaped plate 2. As shown in FIG. 3, the insulating frame 11 is joined to the heat radiating plate 10 to form the semiconductor package 20.

The flat plate 1 is made of a metal material containing copper as a main component. Further, the flat plate 1 has an upper surface including the mounting portion 1a of the semiconductor element. The flat plate 1 functions as a base for positioning and fixing the semiconductor element (details will be described later) to the mounting portion 1a. Further, the flat plate 1 functions as a heat radiating body that dissipates heat generated when the semiconductor element mounted on the mounting portion 1a operates to the outside. The heat generated by the semiconductor element is conducted while diffusing diagonally downward (direction spreading in a plan view) from the upper surface to the lower surface of the flat plate 1. The heat conducted on the lower surface of the flat plate 1 is dissipated to the outside directly or via a heat dissipation medium (metal plate, metal fin, cooling tube, etc.) attached to the lower surface.

The flat plate 1 is formed of a metal material containing copper as a main component in consideration of the thermal conductivity as described above. Examples of the metal material containing copper as a main component include oxygen-free copper containing 99.9% by mass or more of copper, an alloy material containing copper as a main component, or a composite in which copper layers and copper-molybdenum composite layers are alternately laminated. Materials and the like can be mentioned. Examples of the alloy material containing copper as a main component include alloy materials and composite materials containing 99% by mass or more of copper. The flat plate 1 can be manufactured by using, for example, a composite material in which granular materials such as diamond and carbon are dispersed in addition to copper. In this case, as the metal material forming the flat plate 1, for example, a material having a thermal conductivity of 300 W / mK or more is selected.

The mounting portion 1a of the semiconductor element is a portion where the semiconductor element is actually mounted and joined and fixed. Examples of the semiconductor element include a semiconductor integrated circuit element in which an integrated circuit is arranged on a semiconductor substrate such as a silicon substrate, a gallium nitride (GaN) semiconductor substrate, or a silicon carbide (SiC) semiconductor substrate. The semiconductor integrated circuit element may be a power semiconductor element used for controlling various vehicles and the like. The mounting portion 1a has, for example, an external dimension similar to that of a semiconductor element in a plan view.

The frame-shaped plate 2 has an inner side surface 2a joined to the outer surface 1b of the flat plate 1. That is, the outer surface 1a of the flat plate 1 housed in the frame of the frame-shaped plate 2 and the inner side surface 2a of the frame-shaped plate 2 in contact with the outer surface 1a are joined to each other. The joining of the flat plate 1 and the frame-shaped plate 2 is performed, for example, via a joining material (not shown) such as silver wax (silver-copper alloy).

The frame plate 2 is made of a metal material containing an iron-nickel-cobalt alloy as a main component. The composition ratio of the iron-nickel-cobalt alloy is, for example, 54% by mass of iron, 29% by mass of nickel, and 17% by mass of cobalt. As the metal material forming the frame-shaped plate 2, for example, a material having a composition such that the ^{coefficient of thermal expansion is 8 × 10 −6 / K or less is selected.} As such a metal material, for example, an iron-nickel alloy (65% by mass of iron, 35% by mass of nickel), tungsten, molybdenum, and titanium can be used. Further, the frame-shaped plate 2 may be made of an alloy containing these metals.

As described above, the frame-shaped plate 2 is made of a material having a smaller coefficient of thermal expansion than that of the flat plate 1, and has a function of suppressing the coefficient of thermal expansion of the entire heat dissipation plate 10 including the flat plate 1 to a low level. Further, the frame-shaped plate 2 has a function of suppressing expansion in the lateral direction (outward in a plan view) due to heat when the insulating frame is joined to the heat radiating plate 10. Due to the above-mentioned functions of the frame-shaped plate 2 and the dimensional conditions described later, it is possible to suppress deformation such as warpage when the frame-shaped plate 2 is joined to the insulating frame.

That is, in a plan view, the dimension W between the inner side surface 2a of the frame-shaped plate 2 and the outer surface 2b facing the inner side surface 2a thereof faces the inner side surface 2a of the frame-shaped plate 2 and the inner side surface 2a thereof. It is 7.5% or more of the dimension L of the flat plate 1 located between the inner side surface 2a and the flat plate 1. That is, the width W of the frame portion of the frame-shaped plate 2 (hereinafter, also referred to as the width of the frame-shaped plate 2) is the length L of the flat plate 1 exposed in the frame (hereinafter, also referred to as the exposed length of the flat plate 1). On the other hand, it is widely set to the extent that the condition of W ≧ 0.075 × L is satisfied. As a result, the coefficient of thermal expansion (apparent thermal expansion coefficient) of the entire heat radiation plate 10 including the frame-shaped plate 2 can be brought close to the coefficient of thermal expansion of the insulating frame 11, and the thermal stress can be effectively reduced. Further, it is possible to suppress the expansion of the flat plate 1 during heating as described above. Therefore, for example, the heat radiating plate 10 can be easily reduced in deformation after joining the insulating frame 11.

Further, the width W of the frame-shaped plate 2 is the distance LA between the outer surface 2b facing the inner side surface 2a of the frame-shaped plate 2 and the outer peripheral position of the mounting portion 1a adjacent to the inner side surface 2a in a plan view. It is less than the dimension obtained by subtracting 0.3 mm from. That is, the width W of the frame-shaped plate 2 is narrow enough to satisfy the condition of W ≦ LA −0.3 (mm) with respect to the distance LA from the outer surface 2b of the frame-shaped plate 2 to the outer periphery of the mounting portion 1a in a plan view. It is set. The distance LA between the outer surface 2b of the frame-shaped plate 2 and the outer periphery of the mounting portion 1a is the sum of the width W of the frame-shaped plate 2 and the partial length of the flat plate 1 existing between them.

In other words, in a plan view, the mounting portion 1a and the inner surface of the frame-shaped plate 2 are separated from each other by 0.3 mm or more. This distance is a distance for sufficiently diffusing heat laterally from the mounting portion 1a (semiconductor element) toward the lower surface of the flat plate 1 in the flat plate. As a result, the thermal conductivity of the heat radiating plate 10 including the frame-shaped plate 2 as a whole can be increased to, for example, 300 W / mK or more.

That is, since the frame-shaped plate 2 satisfying the above-mentioned dimensions constitutes the heat radiating plate 10 together with the flat plate 1, a heat radiating plate effective for both improvement of heat dissipation to the outside and reduction of deformation is provided. can do. When the heat radiating plate 10 is used for the semiconductor package 20, the heat radiating plate 10 is less likely to be deformed such as warped, and the heat radiating plate 10 can be made into a semiconductor package 20 having excellent heat dissipation to the outside.

The shape and dimensions of the flat plate 1 in a plan view are, for example, a rectangular shape having a side length of 5 to 50 mm. The thickness of the flat plate 1 is set to, for example, about 0.5 to 5 mm. The frame-shaped plate 2 has, for example, a rectangular frame shape, and the dimensions of the frame portion W are set as described above. The thickness of the frame portion 2 is set to be about the same as the thickness of the flat plate 1.

The flat plate 1 and the frame-shaped plate 2 can be manufactured, for example, by subjecting the above-mentioned lump of metal material or the like to a process appropriately selected from metal processing such as rolling, punching, pressing, cutting, polishing and etching. ..

The heat radiating plate 2 having the above configuration may be, for example, the following. That is, for example, as shown in FIG. 2, in a plan view, the flat plate 1 may have a rectangular shape and the frame-shaped plate 2 may have a rectangular frame shape. At this time, the dimension between the first inner side surface 2aa located on the long side side of the frame-shaped plate 2 and the first outer surface 2ba facing the first inner side surface 2aa is set to the short side side of the frame-shaped plate 2. It may be set to be 7.5% or more of the dimension L of the flat plate 1 located between the second inner side surface 2ab located and the other second inner side surface 2ab facing the second inner side surface 2ab. .. In other words, the width of the frame portion on the long side side of the rectangular frame-shaped plate 2 (hereinafter, also referred to as the width on the long side) Wa is the length of the exposed upper surface of the rectangular plate-shaped flat plate 1 in the long side direction. It is set so as to satisfy the relationship of Wa ≧ 0.075 × La with respect to La (hereinafter, also referred to as the long side length).

In addition to this, the frame-shaped plate 2 has a dimension Wa between the first outer side surface 2ba facing the first inner side surface 2aa and the outer peripheral position of the 1a mounting portion adjacent to the first inner side surface 2aa. The distance between them may be less than or equal to the dimension obtained by subtracting 0.3 mm from LAa. That is, the width Wa of the frame portion on the long side of the frame-shaped plate 2 is Wa ≦ LAa −0.3 (mm) with respect to the distance LAa from the first outer surface 2ba of the frame-shaped plate 2 to the outer periphery of the mounting portion 1a. It is set narrow enough to satisfy the conditions. The distance LAa between the first outer surface 2ba of the frame-shaped plate 2 and the outer periphery of the mounting portion 1a is the sum of the width Wa of the frame-shaped plate 2 and the partial length of the flat plate 1 existing between them. be.

That is, on the long side of the frame-shaped plate 2, the mounting portion 1a and the first inner side surface 2aa of the frame-shaped plate 2 are separated from each other by 0.3 mm or more in a plan view. This distance is a distance for sufficiently diffusing heat in the lateral direction in the flat plate 1 as in the above example. With this configuration, the thermal conductivity of the heat radiating plate 10 as a whole including the frame-shaped plate 2 can be effectively increased to, for example, 300 W / mK or more, further, for example, 350 W / mK or more.

Further, in this case, the width of the frame portion of the frame-shaped plate 2 should be more reliably secured on the long side side of the rectangular frame-shaped frame-shaped body 2 on which a larger thermal stress tends to act. Can be done. Therefore, it is possible to effectively reduce deformation such as warpage of the entire heat radiating plate 10 due to thermal stress. Further, on the long side of the rectangular plate-shaped flat plate 2 in which larger heat conduction to the outside is preferable, the distance from the mounting portion 1a to the outer periphery of the flat plate 1 (that is, the heat diffusion space in the lateral direction) is more reliably secured. can do. Therefore, the heat radiating plate 10 can be effectively used for suppressing deformation such as warpage and improving heat dissipation to the outside.

In the heat radiating plate 10 having the above configuration, the flat plate 1 may be made of copper and the frame-shaped plate 2 may be made of an iron-nickel-cobalt alloy. In this case, the thermal conductivity of the flat plate 1 can be brought close to the thermal conductivity (about 380 W / mK) as the physical characteristics of copper. Further, it becomes easier to improve the thermal conductivity of the heat radiating plate 10 to 300 W / mK or more, further 350 W / mK or more. Further, the coefficient of thermal expansion of the frame-shaped plate 2 can be effectively approximated to the coefficient of thermal expansion of the insulating frame 11 made of, for example, a ceramic material. Therefore, in this case, the heat radiating plate 10 can be made effective by improving the heat radiating property and reducing the deformation of the heat radiating plate 10.

Further, in this case, it is also advantageous to improve the strength of the bond between the flat plate 1 and the frame-shaped plate 2 via a brazing material such as silver wax. That is, the brazing material as described above has good wettability with respect to copper and iron-nickel-cobalt alloys. Therefore, it is easy to improve the bonding strength of the flat plate 1 and the frame-shaped plate 2 with the brazing material, and thereby the bonding strength can also be effectively improved.

The copper forming the flat plate 1 is, for example, oxygen-free copper, which is a material having a copper content of 99.9% by mass or more. In the heat radiating plate 10, a plating layer such as nickel or gold may be adhered to the exposed surfaces of the flat plate 1 and the frame-shaped plate 2. The gold-plated layer or the like can reduce the possibility of oxidation and corrosion of the heat dissipation plate 10.

As described above, the semiconductor package 20 of the embodiment is located on the heat radiating plate 10 having any of the above configurations and the heat radiating plate 10, and has an insulating frame having a lower surface joined to the upper surface of the frame-shaped plate 2. It has 11 and. The heat radiating plate 10 including the rectangular flat plate 1 and the frame-shaped plate 2 has advantages in heat dissipation and deformation suppression as described above. In the following, basically, the heat dissipation plate 10 in the form shown in FIGS. 2 and 3 and the semiconductor package 20 and the semiconductor device 30 including the heat dissipation plate 10 will be described as an example.

The insulating frame 11 functions as an electrically insulating substrate in which, for example, a conductor 12 such as a wiring conductor or a connection pad electrically connected to a semiconductor element mounted on the mounting portion 1a is located. A plurality of conductors 12 may be located on the insulating frame 11. Since the plurality of conductors 12 are electrically insulated from each other by the insulating frame 11, those may be electrically connected to external electric circuits having different potentials from each other.

The insulating frame 11 is a ceramic such as an aluminum oxide sintered body, an aluminum nitride sintered body, a silicon nitride sintered body, a silicon carbide sintered body, a glass ceramic sintered body, and a mulite sintered body. It is formed by an insulating material selected from the materials.

The insulating frame 11 is not limited to the one made of a ceramic material, and may be made of a material including a resin material such as an epoxy resin, a polyimide resin, and a polyamide resin. In this case, the material forming the insulating frame 11 may be a material obtained by impregnating a glass cloth with a resin material (so-called FR4). Further, an inorganic filler such as a glass or ceramic material may be added to the resin material.

The insulating frame 11 has a rectangular shape having an external dimension in a plan view of, for example, a side length of about 5 to 50 mm. The insulating frame 11 may have a square shape or the like in which the length of one side is the above value. Further, the insulating frame 11 has a rectangular or square shape having a side length of about 5 to 49 mm in terms of the opening size of the frame portion (dimensions such as a square shape formed by the inner side surface in a plan view). Further, the width W (Wa) of the frame-shaped plate 1 frame portion is as described with respect to the heat dissipation plate 10 described above. The external dimensions and the opening dimensions of the insulating frame 11 may be determined so as to satisfy the range of the width W (Wa) of the frame portion.

The thickness of the insulating frame 11 can be arbitrarily set as long as it satisfies the characteristics such as electrical insulation and mechanical strength required for having the function as the electrically insulating substrate. In this case, the productivity of the insulating frame 11, the workability of joining to the heat radiating plate 10 (that is, the productivity of the semiconductor package 20), the economic efficiency (so-called cost), and the like may be considered. The thickness of the insulating frame 11 is set to, for example, about 0.3 to 1.5 mm.

The insulating frame 11 can be manufactured as follows, for example, when it is made of an aluminum oxide sintered body. First, raw material powders such as aluminum oxide, silicon oxide, calcium oxide and magnesium oxide are kneaded with an organic solvent and a binder to prepare a slurry. Next, the slurry is molded into a strip by a molding method such as a doctor blade method or a lip coater method to prepare a ceramic green sheet. Then, the ceramic green sheet is cut into a plurality of sheets having an appropriate shape and size, and these sheets are laminated as needed. The insulating frame 11 can be manufactured by the above steps. The above sheets may be cut into a predetermined frame shape and then laminated, or may be laminated in a flat plate shape, and then the central portion of the laminated body in a plan view is punched out to form a predetermined frame shape. You may.

Further, if the insulating frame 11 is made of a material containing a resin material, it can be manufactured as follows. First, the glass cloth is impregnated with an uncured epoxy resin. Next, the epoxy resin is cured by means such as heating to form a plate-shaped composite material. Then, the plate-shaped composite material is processed into a predetermined shape and size by a method such as cutting. The insulating frame 11 can be manufactured by the above method.

The bonding between the heat radiating plate 10 and the insulating frame 11 is performed via a brazing material containing silver wax such as silver-copper eutectic wax. In this case, a metal layer for brazing (not shown) may be provided in advance on the portion (part of the surface) to which the heat radiating plate 10 is joined in the insulating frame 11.

The conductor 12 such as the wiring conductor described above and the metal layer for brazing are formed of, for example, a metal material such as tungsten, molybdenum, manganese, copper, silver, gold, nickel, and cobalt. The metal layer such as the conductor 12 may be made of an alloy material containing at least one of the above metal materials. Further, a plurality of metal layers made of different metal materials may be included.

The metal layer such as the conductor 12 is arranged on the insulating frame 11 in the form of, for example, a metallized layer or a plated layer. In this case, one metal layer may include a plurality of forms. For example, the metal layer may be formed by coating the surface of a tungsten metallized layer with a plating layer such as nickel and gold.

The metal layer 12 can be formed as follows, for example, in the case of a tungsten metallized layer. That is, first, the tungsten powder is kneaded with an organic solvent and a binder to prepare a metal paste. Next, this metal paste is printed in a predetermined pattern on the surface of the ceramic green sheet (sheet after cutting) to be the insulating frame 11. Then, the metal paste is fired at the same time as the sheet. By the above steps, a metal layer such as a conductor 12 can be formed on the insulating frame 11. In this case, as described above, a plating layer such as nickel or gold may be further adhered to the surface of the metallized layer of tungsten.

The external dimensions of the insulating frame 11 in a plan view are set to, for example, the same as or less than the external dimensions of the heat radiating plate 10. In the example shown in FIG. 5, the external dimensions of the insulating frame 11 are set to be slightly smaller than the external dimensions of the heat radiating plate 10. Therefore, the outer peripheral portion of the heat radiating plate 10 (frame-shaped plate 2) is exposed along the outer periphery of the insulating frame 11. Further, the opening size of the insulating frame 11 in a plan view is set to, for example, the same level as or less than the opening size of the frame-shaped plate 2 of the heat radiating plate 10. Therefore, the frame-shaped plate 2 is not exposed inside the insulating frame 11.

That is, in this example, in a plan view, the exposure range of the flat plate 1 on the heat radiating plate 10 is slightly smaller than that on the heat radiating plate 10 in the semiconductor package 20. Even in such a case, since the width Wa of the frame portion of the frame-shaped plate 2 is widely secured, the deformation of the heat radiating plate 10 is effectively reduced. Further, since heat is dissipated from the heat dissipation plate 10 to the outside mainly from the lower surface side of the flat plate 1, heat dissipation can be ensured. That is, if the shapes and dimensions of the flat plate 1 and the frame-shaped plate 2 as the heat radiating plate 10 are set as described above, the deformation reduction (reliability, mountability, etc.) and the heat radiating property of the semiconductor package 20 are effective. Can be enhanced to.

As described above, the semiconductor package 20 may have the following conditions when the flat plate 1 has a rectangular shape and the frame-shaped plate 2 has a rectangular frame shape in a plan view. That is, for example, as shown in FIG. 5, the frame is larger than the dimension Wa between the first inner side surface 2aa located on the long side side of the frame-shaped plate 2 and the first outer surface 2ba facing the first inner side surface 2aa. The dimension between the second inner side surface 2ab located on the short side side of the shaped plate 2 and the second outer side surface 2bb facing the second inner side surface 2ab may be larger. In other words, in the rectangular frame-shaped frame plate 2, the width Wb of the frame portion on the short side side may be larger than the width Wa of the frame portion on the long side side. That is, Wa <Wb may be satisfied. However, as in each of the above examples, Wa = Wb may be used.

When Wa <Wb, the length of the flat plate 1 can be shortened, and by shortening the flat plate 1, the deformation stress of the flat plate 1 in the long side direction at a high temperature becomes small, and deformation such as warpage is suppressed. The effect of can be enhanced. Further, as the flat plate 1 is shortened, the deformation stress in the long side direction of the flat plate 1 at a high temperature is reduced, so that the width Wa can be further reduced, and the effect of improving heat dissipation can be enhanced.

FIG. 6A is a perspective view of the semiconductor package shown in FIG. 5 as viewed from above. FIG. 6B is a perspective view showing a modified example of FIG. 6A. In this example, the conductor 12 on the upper surface of the insulating frame 11 functions as a pad to which the terminal 13 is connected. Further, the terminal 13 in this example is a metal lead terminal. Leads (terminals 13) are joined to the pad (conductor 12) via a joining material such as silver wax. The terminal 13 is an external terminal for external connection in the semiconductor package. The terminal 13 is electrically connected to an external electric circuit on the opposite side (outer end side) to the conductor 12 via a conductive connecting material such as solder or a conductive adhesive.

The electrode of the semiconductor element 21 is electrically connected to the side (inner end side) of the terminal 13 bonded to the conductor 12 or the conductor 12 in the semiconductor device 30 described later. As a result, the semiconductor element 21 and the external electric circuit can be electrically connected.

The terminal 13 is formed of a material appropriately selected from metal materials such as iron-nickel-cobalt alloy, iron-nickel alloy, copper and copper alloy. The terminal 13 is manufactured by subjecting a raw material such as an iron-nickel-cobalt alloy plate to metal processing appropriately selected from cutting, rolling, pressing, cutting, polishing, etching and the like. ..

FIG. 7 is a top view showing the semiconductor device 30 according to the embodiment of the present invention. As shown in FIG. 7, the semiconductor device 30 of the embodiment is basically configured by the semiconductor package 20 having the above configuration and the semiconductor element 21 mounted on the mounting portion 1a. The semiconductor element 21 is, for example, a semiconductor integrated circuit element, an optical semiconductor element, a sensor element, or the like. Even if the semiconductor element 21 is a semiconductor integrated circuit element that generates a relatively large amount of heat during operation, the heat dissipation from the mounting portion 1a to the outside is enhanced as described above, so that the temperature rise of the semiconductor element 1a is reduced. Therefore, it can be operated stably. Further, since the deformation as a semiconductor package is suppressed, the semiconductor element 1a can be easily mounted and the long-term reliability can be easily improved.

For example, the semiconductor element 21 is electrically connected to the terminal 13 as described above, and is electrically connected to an external electric circuit. In this case, the semiconductor element 21 may be connected to the conductor 12. The connection between the semiconductor element 21 and the terminal 13 or the conductor 12 is performed via a conductive connecting material (not shown) such as a bonding wire or a ribbon conductor. The conductor 12 when the bonding wire is connected functions as a bonding pad.

In the example shown in FIG. 7, in addition to the semiconductor element 21, other components 22 are also mounted on the upper surface of the flat plate 1. The other component 22 may be, for example, an electronic component (so-called passive component or the like) such as a capacitive element, an inductor element, and a resistor. Further, the other component 22 may be an auxiliary board on which a plurality of electronic components are mounted (no sign as an auxiliary board). The other component 22 has, for example, functions such as charge supply, impedance matching, and phase adjustment that stabilize the differential of the semiconductor element 21. In the semiconductor device 30, the semiconductor element 21 and other parts 22 may be sealed with a sealing material such as a lid or a resin material.

The other components 22 are also electrically connected to the inner end side of the terminal 13 or the conductor 12 via a conductive connecting material such as a bonding wire. The conductor 12 and the terminal 13 electrically connected to the other component 22 may be formed by the same method using the same material as the conductor 12 and the terminal 13 to which the semiconductor element 21 is connected.

FIG. 8 is a top view showing another example of the semiconductor device 30 according to the embodiment of the present invention. In the example shown in FIG. 8, the insulating frame 11 has a rectangular frame shape in a plan view, and the frame width thereof is wider than that in the example shown in FIG. Further, the frame width on the short side is larger than the frame width on the long side. In this case, the mechanical strength and rigidity of the insulating frame 11 can be ensured high on the short side. Therefore, the possibility of deformation in the semiconductor package 20 can be effectively reduced. Therefore, it is also advantageous to improve the long-term reliability of the semiconductor device 30 and the like.

Further, in the example shown in FIG. 8, the inner circumference of the insulating frame 11 has an arc shape in a plan view. As a result, it is possible to reduce the linear concentration of stress such as thermal stress in the inner peripheral portion of the insulating frame 11. Therefore, it is possible to reduce the possibility of cracks or the like occurring in the insulating frame 11 and improve the reliability of the semiconductor device 30. In this case, for example, even if the insulating frame 11 and the flat plate 1 are joined to each other, the concentration of thermal stress in the inner peripheral portion of the insulating frame 11 can be reduced, so that the reliability can be improved as described above. ..

The effect of the heat radiating plate according to the embodiment of the present invention was confirmed. The effect was confirmed by measuring the deformation of the heat dissipation plate with a three-dimensional shape measuring machine and calculating the amount of heat dissipation by simulation.

Specifically, a flat plate made of oxygen-free copper, an iron-nickel-cobalt alloy, and a frame-shaped plate were used to prepare a heat dissipation plate having the form shown in FIG. 2 in the above embodiment. The heat radiating plate has dimensions of 18 mm × 10 mm in a plan view. Regarding the heat radiating plate, the width Wa of the frame portion of the frame-shaped plate, the dimension (length) La of the exposed flat plate, and the distance LAa from the outer surface of the frame-shaped plate to the outer periphery of the mounting portion of the semiconductor element are shown in Table 1. I set it to a numerical value. In Table 1, LAa-W
The value of a, that is, the distance between the inner side surface of the frame-shaped plate and the outer peripheral position of the mounting portion adjacent to the inner side surface in a plan view is shown as ba.

The amount of deformation of the heat radiating plate 10 is measured three-dimensionally after an insulating frame made of an aluminum oxide sintered body is bonded to the heat radiating plates of Samples 1 to 8 shown in Table 1 using silver-copper eutectic brazing filler metal. It was measured using a shape measuring machine. The simulation of the heat dissipation amount was performed by calculating the temperature of the semiconductor element and the thermal resistance of the heat dissipation plate when a heat amount of 400 W was applied to the mounting portion of the simulation models of Samples 1 to 8 shown in Table 1.

Regarding deformation suppression, those with a deformation amount of 35 μm or less were regarded as acceptable (◯), and those with a deformation amount exceeding that were regarded as unacceptable (×). Further, those having a deformation amount of 15 μm or less were regarded as particularly good (⊚). Regarding heat transfer (heat dissipation), those with a thermal conductivity of 300 W / mK or more are acceptable (○).
Those less than that are not allowed (x). Further, those having a thermal conductivity of 330 W / mK or more were regarded as particularly good (⊚). Those that are not impossible in terms of both deformation suppression and heat dissipation were marked as acceptable (○) in the comprehensive judgment.

As can be seen from the results shown in Table 1, by selecting the configuration of the heat radiating plate (sample numbers 2 to 5, 7, 8) of the embodiment of the present invention, it is compared with that of the comparative example (sample numbers 1, 6). It was confirmed that the effect of suppressing deformation and improving heat dissipation is high.

Further, in the heat radiating plate of the embodiment of the present invention, the larger Wa / La, that is, the wider the width of the frame-shaped plate is relative to the exposed length of the flat plate, the more advantageous the tendency in suppressing deformation is confirmed. did it. Further, it was confirmed that the larger the ba, that is, the longer the length of the flat plate located between the mounting portion and the frame-shaped plate, the more advantageous the heat dissipation.

1 ・ ・ Flat plate 1a ・ ・ Mounting part 1b ・ ・ Inner side surface (of flat plate) 2 ・ ・ Frame-shaped plate 2a ・ ・ Inner side surface (of frame-shaped plate) 2aa ・ ・ First inner side surface 2ab ・ ・ Second inner side surface 2b・ ・ Outer surface (of frame-shaped plate) 2ba ・ ・ First outer surface
10 ... Heat dissipation plate
11 ... Insulation frame
12 ... Conductor
13 ... Terminal
20 ... Semiconductor package
21 ... Semiconductor device
22 ... Other parts
30 ... Semiconductor device L ... Exposed length of flat plate La ... Exposed length of flat plate (in the long side direction) LA ... Distance between the outer surface of the frame-shaped plate and the outer circumference of the mounting part LAa ... Frame Distance between the first outer surface of the shaped plate and the outer circumference of the mounting portion W ... Width of the frame portion of the frame-shaped plate Wa ... Width of the frame portion of the frame-shaped plate (on the long side) Wb ... (Short) Width of the frame part of the frame-shaped plate (on the side)

Claims (6)

It is made of a metal material containing copper as the main component, and is composed of a flat plate having an upper surface including a mounting portion of a semiconductor element and a metal material containing an iron-nickel-cobalt alloy as a main component, and is located surrounding the flat plate in a plan view. A frame-shaped plate having an inner surface joined to the outer surface of the flat plate is provided, and the dimension between the inner surface of the frame-shaped plate and the outer surface facing the inner surface in a plan view is provided. Is 7.5% or more of the dimension of the flat plate located between the inner side surface of the frame-shaped plate and the other inner side surface facing the inner side surface, and the outer surface facing the inner side surface. A heat radiating plate having a dimension equal to or less than a dimension obtained by subtracting 0.3 mm from the distance between the outer peripheral position of the mounting portion adjacent to the inner side surface. In a plan view, the flat plate has a rectangular shape and the frame-shaped plate has a rectangular frame shape.
The dimension between the first inner side surface located on the long side side of the frame-shaped plate and the first outer surface facing the first inner side surface is the second inner side surface located on the short side side of the frame-shaped plate. 7.5% or more of the size of the flat plate located between the surface and the other second inner surface facing the second inner surface, and the first outer surface facing the first inner surface and the first surface. 1 The heat radiating plate according to claim 1, wherein the dimension is equal to or less than the dimension obtained by subtracting 0.3 mm from the distance from the outer peripheral position of the mounting portion adjacent to the inner side surface. The heat radiating plate according to claim 1 or 2, wherein the flat plate is made of copper and the frame-shaped plate is made of an iron-nickel-cobalt alloy. The heat radiating plate according to any one of claims 1 to 3,
A semiconductor package that is located on the heat dissipation plate and includes an insulating frame body having a lower surface joined to the upper surface of the frame-shaped plate. In a plan view, the flat plate has a rectangular shape and the frame-shaped plate has a rectangular frame shape.
The second inner surface located on the short side side of the frame-shaped plate is larger than the dimension between the first inner side surface located on the long side side of the frame-shaped plate and the first outer surface facing the first inner side surface. The semiconductor package according to claim 4, wherein the dimension between the side surface and the second outer surface facing the second inner side surface is larger. The semiconductor package according to claim 4 or 5.
A semiconductor device including a semiconductor element mounted on the mounting portion.

Images