JP2577063Y2 - Semiconductor package - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a package for accommodating a semiconductor device, and more particularly to a semiconductor package having a heat radiating structure for providing an air cooling function.

[0002]

2. Description of the Related Art Heretofore, in a semiconductor package such as a high-speed, high-density LSI, a heat radiator for radiating and cooling heat generated in a chip has been used. For example,
As shown in FIGS. 8A and 8B, the heat radiator 10 was attached to the cap 21 of the semiconductor package 20 containing the chip. Further, as shown in FIG. 8C, there is a semiconductor package in which a cap itself is used as a heat radiator 10. The radiator 10 has a comb shape in which a base 12 and a fin 11 are integrally formed. As a material of the radiator 10, a metal such as aluminum has conventionally been used. In order to make the coefficient of thermal expansion coincide with the coefficient of thermal expansion, aluminum nitride ceramics having excellent thermal conductivity is used.

[0003] The manufacturing method when such a heat radiator 10 is formed of ceramics is as follows. First, the rubber material is filled with ceramic raw materials and rubber pressed,
The periphery of the obtained molded body is subjected to cutting to form a block shape. Next, after firing the block-shaped compact, a plurality of grooves are ground on the block-shaped sintered compact 30 with a diamond cutter 31 as shown in FIG.
By grinding the lower surface, a heat radiator 10 having a plurality of fins 11 as shown in FIG. 7A was formed.

[0004]

However, in the above-described conventional manufacturing method, since a plurality of groove grinding processes are performed on the block-shaped sintered body 30, the processing efficiency is extremely low. In addition, since there are many parts to be ground, there is much waste of raw materials and the cost is high.

In addition, in order to grind the sintered body, it is necessary to improve the grindability by adding boron nitride (BN) to the aluminum nitride ceramics forming the radiator 10. There is a limit to improving the thermal conductivity. In addition, only a simple fin shape can be obtained due to grinding, and the cooling effect is low.

[0006]

In view of the above-mentioned problems, the present invention has been made in consideration of the above-mentioned problems, and at least one of a ceramic cap and a ceramic base constituting a semiconductor package has an aluminum nitride having a heat dissipation structure such as an uneven shape or a honeycomb shape. A semiconductor package comprising a high-quality ceramic fin, wherein the fin and the cap and / or the base are provided with concave and convex portions having shapes that match each other,
By firing and integrating with these concave and convex portions engaged,
Alternatively, the base made of aluminum nitride ceramic constituting the heat radiator and the fins are provided with uneven portions having shapes matching with each other, and the integrated body is fired and integrated in a state where these uneven portions are engaged with each other, and the cap and / or It is joined to the base.

The semiconductor package of the present invention is obtained by directly joining and integrating a plurality of ceramic fins to a cap or a base by simultaneous firing, or by joining a plurality of ceramic fins to a base in advance by simultaneous firing. Is bonded to a cap or a base.

Further, the semiconductor package of the present invention has an uneven heat dissipation structure as a whole by joining a plurality of fins. It is also possible to enhance the sex.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below (the same parts as in the prior art are denoted by the same reference numerals).

As shown in FIG. 1A, the heat radiator 10 constituting the semiconductor package of the present invention has a comb shape (concavo-convex) shape obtained by joining and integrating a plurality of fins 11 with a base 12, and has a high thermal conductivity. Of aluminum nitride ceramics. Then, as shown in FIG. 1B, the semiconductor package of the present invention in which the heat radiator 10 is bonded is shown in FIG.
By joining the base 12 of the radiator 10 to the cap 21 of the semiconductor package 20 including the cap 21, the base 22, and the pins 23, heat generated in the semiconductor chip can be released and cooled.

Further, as shown in FIG. 1C, a plurality of fins 11 can be directly bonded and integrated to a cap 21 of a semiconductor package 20. further,
Although not shown, the fins 11 may be integrally joined to the base 22 side.

A description will now be given of an example having the shape shown in FIGS. 1 (A) and 1 (B). As described above, the heat radiator 10 constituting the semiconductor package 20 of the present invention is formed by separately forming the base 12 and the fin 11 and joining them. The specific joining method is as follows.

As shown in FIG. 2 (A), the substrate 12,
The fins 11 and the fins 11 are separately formed, and are joined by simultaneous firing. For example, as shown in FIG. 3, a base 12 having a plurality of recesses 12a, a fin 11 having a shape corresponding to the recesses 12a, and being formed separately by press forming, tape forming, extrusion forming, etc. of ceramics. I do. Then, in the state of the formed body before firing, the fin 11 is inserted into and engaged with the concave portion 12a of the base 12, and a binder at the time of molding or a slurry made of the same type of ceramic raw material is interposed between the two. In this case, firing and integration may be performed at the same time. Alternatively, the substrate 12
If the raw material is adjusted so that the side shrinks more than the fins 11, they can be fired and integrated at the same time without any intervention between them.

As described above, if the base 12 and the fins 11 are bonded by simultaneous firing, for example, the fins 11 and the bases 12 are bonded in advance by bonding via a bonding agent such as metallized, solder, or glass. Differently, there is no different substance between the two, the heat transfer from the base 12 to the fins 11 can be improved, and the cooling efficiency can be increased.

In another embodiment, as shown in FIG. 4, the fin 11 may be formed in a rod shape and inserted into the concave portion 12a of the base 12, and both may be fired simultaneously. When the fins 11 are formed in a rod shape as described above, the heat radiation area is increased, so that the cooling effect can be further enhanced.

Further, in the above embodiment, the fin 11 has a rectangular plate shape or a round bar shape.
In the heat radiator 10 of the present invention, since the fins 11 are formed separately, a more complicated shape can be obtained. For example, heat dissipation can be enhanced by forming the fins 11 into a triangular shape, or by forming the fins 11 into a corrugated shape as described later.

The arrangement of the fins 11 on the base 12 does not need to be regular and can be arranged freely. For example, as shown in plan views in FIGS. 5A to 5D, the fins 11 having a prismatic shape, a round bar shape, a plate shape, or the like can be changed in direction from each other, or can be combined in different shapes. By arranging the fins 11 irregularly in this manner, a cooling medium such as air becomes turbulent, and the cooling effect can be further enhanced.

The radiator 1 obtained as described above
Also, when bonding 0 to the cap 21 of the semiconductor package 20, the bonding and integration may be performed by simultaneous firing.

Further, as a ceramic having a high thermal conductivity of 100 W / m · K or more, aluminum nitride (A
1N), beryllium oxide (BeO), silicon carbide (Si
Although there are various types such as C), as the material of the base 12 and the fins 11 constituting the radiator 10 of the present invention, aluminum nitride ceramics having particularly high thermal conductivity is used. Further, among them, aluminum nitride ceramics mainly containing AlN and containing sintering aids such as oxides, nitrides and fluorides of rare earth elements and alkaline earth elements are the most excellent in terms of thermal conductivity. I have. Then, after adding and mixing a predetermined binder to the ceramic raw material powder composed of these main components and the sintering aid, the mixture is formed into the shapes of the fins 11 and the base 12 by press molding, tape molding, extrusion molding or the like as described above. Then, the heat radiator 10 according to the present invention can be obtained by joining after the simultaneous firing or the firing.

In the above embodiment, FIG.
1B, the base 12 and the fin 11 are joined and integrated, but the fin 1 is directly attached to the cap 21 of the semiconductor package as shown in FIG.
The same applies to the case where 1 is joined and integrated.

Further, as another embodiment of the present invention, each fin 11 itself can be formed with an uneven shape or a honeycomb shape. For example, the ceramic heat radiator 10 shown in FIG. 6 is formed by integrally forming a base 12 and fins 11, and has irregularities formed on a side surface 11 a of each fin 11. The semiconductor package of the present invention can be configured by joining and integrating the semiconductor package of the present invention. As described above, since the unevenness is formed on the side surface 11a of the fin 11, the surface area can be increased, and the heat dissipation can be enhanced.

The irregularities have a shape extending linearly in the direction of the arrow in the figure, and such a ceramic radiator 10 can be easily manufactured by press molding or extrusion molding. . That is, a mold having such a concave-convex shape is prepared in advance, press-formed or extruded so that a force is applied in the direction of the arrow in the figure, and then fired to obtain a ceramic material shown in FIG. Heat radiator 1
0 can be easily formed. In the case of press molding, the unevenness can also be formed on the end surface of the fin 11 by forming the unevenness on the pressing surfaces of the upper and lower punches.

Further, the fins 11 may have various irregularities. For example, FIG.
As shown in FIG.
As shown in FIG.
(C) As shown in FIG. 7 (D), a plate-shaped body having a projection 11b or a honeycomb-shaped body having a hollow part 11c as shown in FIG. 7 (E) can be used. . Regardless of the shape, the substrate 12
In order to press-mold or extrude the fins 11 integrally, it is necessary that the fins 11 extend linearly in the direction of the arrow in FIG.

In the above embodiment, the base 12 and the fin 11 are integrally formed. However, as in the embodiment shown in FIGS. 1 to 4, the base 12 and the fin 11 are formed separately. Once formed, they can be joined together. In this case, the fins 11 are formed into a shape having irregularities by press molding, extrusion molding, tape molding, or the like, or are processed after these moldings, and are integrally bonded to the separately molded base 12 by simultaneous firing. Thus, it can be manufactured. Thus, if the fin 11 is formed as a separate body, a more complicated uneven shape can be easily formed.

Experimental Example 1 As a working example of the present invention, a radiator shown in FIG. 3 was manufactured. First, as a raw material, AlN as a main component, Er ₂ O ₃ as a sintering aid, and a binder were added and mixed. Next, this raw material was filled in a mold and press-molded to form the base 12 and the plate-like fin 11 separately. The fins 11 of the formed body thus obtained were inserted into the concave portions 12a of the base 12, and were simultaneously fired at 1750 ° C. to be integrated. The final size is 34 × 34 × 21 mm in outer shape, the thickness of each fin is 1.3 mm, and the gap between each fin is 1.3 mm
And the number of fins was 14.

On the other hand, as a comparative example, a ceramic radiator having exactly the same shape and the same size was manufactured by a conventional method. That is, boron nitride (BN) is added to the same ceramic raw material as described above in order to enhance the grindability, the raw material is formed into a block shape by a rubber press, the periphery is cut, fired, and the grooves and The outer periphery and the lower surface were cut to obtain a ceramic radiator.

The time required for each manufacturing process, the material loss, and the thermal conductivity of the heat radiator 10 were compared for the heat radiator 10 of the present invention and the comparative example. The results are as shown in Table 1. there were. In Table 1, the processing time is a ratio when the comparative example is set to 1, and the raw material loss is expressed as a ratio to the starting raw material. As is clear from Table 1, the working time of the embodiment of the present invention is 1 / compared to the comparative example.
It can be seen that the material loss is as short as 10 and that the raw material loss is as small as 1%. Furthermore, since the heat radiator 10 of the present invention does not contain an additive for improving the grinding property, the heat conductivity can be increased, and the characteristics as the heat radiator can be improved.

[0028]

[Table 1]

Experimental Example 2 Next, as an example of the present invention, a ceramic radiator 10 having a fin 11 having an uneven shape shown in FIG. The raw materials and the overall size are the same as those in Experimental Example 1 described above. The thickness t of each fin 11 is 1.5 mm, and the length L is 16
mm, and the angle α of the uneven portion was 45 °. On the other hand, as a comparative example, a ceramic heat radiator 10 made of the same material and having no fins 11 having irregularities was prototyped, and the heat radiating properties of both were compared.

First, the amount of heat radiation (heat loss) q in these fins is as follows: q = √ (hPkA) · θ ₀ · tanh (mL _C ) where k: heat transfer coefficient [W / m · K] h: heat conduction Rate [W / m · K] A: Cross-sectional area [m ² ] P: Fin circumference [m] m = √ (hP / kA) t: Fin thickness [m] L: Fin length [m] L _C = L + t / 2 T ₀ : Fin base temperature [K] T ₁ : External fluid temperature [K] It can be approximated by θ ₀ = T ₀ −T ₁ .

By substituting each value into the above equation, the heat radiation amount q ′ of the heat radiator of the comparative example is q ′ = 1.176 × 10 ⁻² W, whereas the heat radiation amount of the heat radiator of the present invention is q becomes q = 1.639 × 10 ⁻² W, and it is theoretically possible that the ceramic heat radiator of the present invention can improve the heat radiation by about 1.4 times by forming the fin itself with irregularities. I understand.

In addition, when an experiment was conducted to compare the heat radiation properties by actually attaching the heat radiator to the semiconductor package, the semiconductor package of the present invention exhibited excellent heat radiation characteristics as in the above theoretical formula. .

[0033]

As described above, according to the present invention, at least one of the ceramic cap and the ceramic base constituting the semiconductor package is provided with an aluminum nitride ceramic fin having a heat dissipation structure such as an uneven shape or a honeycomb shape. In the semiconductor package comprising: the fin and the cap and / or the base are provided with concavo-convex portions each having a shape conforming to each other, and the fins are integrated by firing, or the radiator is The aluminum nitride ceramic base and the fins were provided with concavo-convex portions each having a shape conforming to each other, and were fired and integrated in a state where these concavo-convex portions were engaged with each other and joined to the cap and / or base. Therefore, different materials do not intervene in the joints of the aluminum nitride ceramic fins, It is possible to produce a ceramic heat radiator comb shape by a simple process Te because, since it is not necessary to increase the grinding of ceramics forming the heat radiator,
A material having high thermal conductivity can be used.

In addition, since the fins forming the ceramic heat radiator are formed with irregularities, the surface area can be increased and the heat radiation characteristics can be further improved.

Therefore, a ceramic heat radiator having excellent characteristics can be obtained at low cost, and it can be suitably used for an ultra-high-speed LSI or the like.

[Brief description of the drawings]

1A is a perspective view showing a heat radiator constituting a semiconductor package of the present invention, and FIGS. 1B and 1C are side views showing the semiconductor package of the present invention.

FIG. 2A is a view showing a manufacturing process of a heat radiator constituting the semiconductor package of the present invention, and FIG. 2B is a sectional view taken along line XX in FIG.

FIG. 3 is a view illustrating a manufacturing process of a heat radiator according to another embodiment of the present invention;

FIG. 4 is a view illustrating a manufacturing process of a heat radiator according to another embodiment of the present invention.

FIGS. 5A to 5D are plan views showing a heat radiator according to another embodiment of the present invention.

FIG. 6 is a perspective view showing another embodiment of the heat radiator constituting the present invention.

FIGS. 7A to 7E are views showing various embodiments of the fin shape of the heat radiator constituting the present invention.

8A is a perspective view showing a conventional ceramic heat radiator, and FIGS. 8B and 8C are side views showing a semiconductor package to which a conventional ceramic heat radiator is attached.

FIG. 9 is a view showing a method for manufacturing a conventional ceramic heat radiator.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Heat radiator 11 ... Fin 11a ... Side surface 11b ... Projection part 11c ... Hollow part 12 ... Base 12a ... Concave part 20 ... Semiconductor package 21 ... Cap 22 ... Base

Continuing from the front page (72) Inventor Takeshi Furuno 10-1 Kawai, Gamo-cho, Gamo-gun, Shiga Prefecture Examiner in the Shiga-Kamo Plant, Kyocera Corporation Ryuji Hibino (56) References JP-A-1-264295 (JP, A) JP-A-5-29499 (JP, A) JP-A-3-79064 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) H01L 23/34-23/473 H01L 23/00 -23/10 H05K 7/20

Claims (1)

(57) [Scope of request for utility model registration] 1. A semiconductor package comprising at least one of a ceramic cap and a ceramic base constituting a semiconductor package, comprising aluminum nitride ceramic fins having a heat dissipation structure such as an uneven shape or a honeycomb shape. And the cap and / or the base are provided with uneven portions each having a shape that matches each other,
By firing and integrating with these concave and convex portions engaged,
Alternatively, the base made of aluminum nitride ceramic constituting the heat radiator and the fins are provided with uneven portions having shapes matching with each other, and the integrated body is fired and integrated in a state where these uneven portions are engaged with each other, and the cap and / or A semiconductor package joined to the base.