JPH0799268A - High-thermal-conductivity-type ceramic package for semiconductor - Google Patents

Abstract

PURPOSE:To decrease thermal resistance lower than a conventional device and to achieve the low cost by containing a metal plate made of Cu or alloy mainly comprising Cu, which is bonded to the surface of a ceramic substrate at the opposite side with respect to the side for mounting a semiconductor element and has the thickness larger than the ceramic substrate. CONSTITUTION:An AlN substrate 1, on the surface of which four semiconductor elements 4 are mounted, a Cu plate 2, which is bonded to the lower surface of the substrate 1, and a metal member 3 made of Cu-W alloy for mounting the substrate and the plate, are provided. Two grooves 31 are provided in the vicinity of the central part of the metal member 3 so as to cross the member. Thus, a mounting part 32 is formed. The Cu plate 2 is brazed to the mounting part 32 of the metal member 3. U-shaped notches are formed at both ends of the metal member 3. When a ceramic package is mounted on a wiring board or the like, the package is fixed to the board with machine screws and the like by utilizing the notches. Thus, the thermal resistance becomes lower than that of a conventional package, and high output-power elements can be mounted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high thermal conductivity ceramic package for semiconductors. More specifically, high power transistors, microwave monolithic ICs (MM
The present invention relates to a high thermal conductive ceramics package for semiconductors, which is suitable for a microwave package or the like which is required to mount a high output device such as an IC).

[0002]

2. Description of the Related Art As the output, operating speed, etc. of various semiconductor devices have been improved, failures due to heat generation thereof have become apparent. Since such a high-speed and high-power semiconductor element generates a large amount of heat, the operating characteristics may deteriorate due to overheating. In order to prevent this inconvenience, such a package for a semiconductor element is configured to mount the semiconductor element on a substrate made of a material having high thermal conductivity. Conventionally, beryllium oxide (BeO), which has excellent thermal conductivity, has been used as a substrate in a package for high-power semiconductor devices that generate a large amount of heat.

[0003]

When BeO is used in a semiconductor device package, the BeO substrate surface is metallized and bonded to a CuW alloy or a Cu metal member to mount the semiconductor device. However, in recent years, the heat generation amount of the semiconductor element has remarkably increased, and the heat dissipation property of the semiconductor element package using BeO is approaching the limit. On the other hand, it has been studied to reduce the thickness of BeO to improve heat dissipation. However, BeO has toxicity and poor workability, making it difficult to reduce the wall thickness. Therefore, in a semiconductor device package using BeO, it is practically impossible to improve heat dissipation by thinning the thickness, and it is not possible to cope with the case where higher heat dissipation is required. Further, materials such as diamond and cubic boron nitride (cBN), which are excellent in heat dissipation, are expensive and not practical for application to semiconductor device packages.

Therefore, an object of the present invention is to provide a novel high thermal conductive ceramics package for semiconductors, which solves the above problems of the prior art.

[0005]

According to the present invention, an AlN or BeO ceramic substrate on which a semiconductor element is mounted,
A metal plate of Cu or an alloy mainly composed of Cu having a thickness equal to or larger than the thickness of the ceramics substrate, the metal plate being bonded to a surface of the ceramics substrate opposite to the side on which the semiconductor element is mounted. There is provided a high thermal conductivity ceramic package for semiconductors.

Further, in the present invention, a semiconductor element is mounted.
A high thermal conductive ceramics package for a semiconductor, comprising a ceramics substrate of AlN or BeO and a metal plate of Cu or an alloy mainly of Cu bonded to a surface of the ceramics substrate on which a semiconductor element is mounted. Will be provided.

The high thermal conductive ceramics package for semiconductors of the present invention is a metal plate of Cu or an alloy mainly composed of Cu and a semiconductor element bonded to the surface of the ceramic substrate on which the semiconductor element is mounted on the side on which the semiconductor element is mounted. It may be provided with both a metal plate of Cu or an alloy mainly of Cu having a thickness equal to or larger than the thickness of the ceramic substrate, the metal plate being bonded to the surface opposite to the side on which is mounted.

As a ceramic package having a structure similar to that of the present invention, Japanese Patent Application Laid-Open No.
There is a ceramic substrate mounted on a metal member disclosed in Japanese Patent No. 103853 in which copper or a copper alloy is metalized or adhered. However, what is disclosed in the publication is for the purpose of stress relaxation between the ceramic substrate and the metal member, and the ceramic package of the present invention refers to the ceramic substrate and copper or copper alloy bonded thereto. The relationship of the thicknesses of the parts is different and can be distinguished.

The metal sheet of Cu or an alloy mainly containing Cu used in the ceramic package of the present invention is most important in its thermal conductivity, and its purity does not matter much. Specifically, the thermal conductivity is 300 W / mK
It is preferably composed of the above metals.

The ceramic package of the present invention further comprises a metal member for mounting the ceramic substrate on which the metal plate is bonded, and the metal member has a thermal conductivity of 100 W /
It is preferably composed of a metal of mK or more. This metal member is, for example, a Cu-W alloy, a Cu-Mo alloy, or a Cu.
It is preferable that

Further, according to the present invention, an AlN or BeO ceramic substrate on which a semiconductor element is mounted and a metal member mounted by directly bonding the substrate are mounted, and the metal member has a thermal conductivity of 100 W / mK or more. Provided is a high thermal conductive ceramics package for semiconductors, which is characterized by being composed of the above metal. In this ceramic package, the metal member is made of Cu or an alloy mainly composed of Cu similar to that used for the above metal plate, and the portion on which the substrate is mounted is thicker than other portions. Is preferred.

[0012]

The ceramic package of the present invention comprises an AlN or BeO ceramic substrate on which a semiconductor element is mounted, and a heat-radiating metal plate of Cu or an alloy mainly containing Cu, which is bonded to at least one surface of the ceramic substrate. In particular, when a metal plate for heat dissipation is joined to the surface of the ceramics substrate opposite to the surface on which the semiconductor element is mounted, this metal plate has a thickness equal to or larger than the thickness of the substrate. In general, the thermal conductivity of BeO is 220 W / mk to 280 W / mK, while the thermal conductivity of the metal plate for heat dissipation used in the present invention is
It is 300 W / mK or more (the thermal conductivity of Cu is 393 W / mK). Therefore, the ceramic package of the present invention has a structure suitable for reducing the thermal resistance of the substrate.

In the ceramic package of the present invention, when a metal plate is joined to the surface of the substrate on which the element is mounted,
It is possible to lower the thermal resistance as compared with the case where a metal plate is joined to the surface on which the element is not mounted. In addition, if the metal plates are joined to both surfaces of the substrate, the thermal resistance can be reduced more effectively. The ceramic package of the present invention has a ceramic substrate (AlN
Insulation can be maintained by the substrate or BeO substrate).

In the ceramic package of the present invention, it is preferable that the substrate to which the above metal plates are joined is mounted on a metal member having a thermal conductivity of 100 W / mK or more. When the thermal conductivity of the metal member is less than 100 W / mK, the heat dissipation of the ceramic package becomes poor. The metal material used for the above-mentioned metal member is, specifically, Cu-W alloy, Cu-
Mo alloys or Cu are preferred. The thickness of the substrate mounting portion of the metal member can be reduced as necessary. That is, when the dimension from the upper surface of the metal member to the mounting portion of the semiconductor element cannot be changed from the mechanical viewpoint when mounting, the thickness of the substrate mounting portion of the metal member is reduced and the above metal plate is bonded. A substrate may be mounted. With such a configuration, even if the thickness of the metal plate bonded to the surface of the substrate on which the semiconductor element is not mounted is equal to or greater than the thickness of the substrate, the metal plate is bonded to the metal member. it can.

The ceramic package of the present invention is manufactured by the following steps. First, an AlN substrate that is an insulator or
Metallize the BeO substrate. The metallization may be a co-firing method in which a metal is directly applied to the green sheet and the green sheet and the metal are co-fired, or a post-metallizing method in which a sintered body is prepared in advance and then metallized. In the post-meratizing method, any method such as a thin film method such as metal vapor deposition and a thick film method such as screen printing can be used. A metal plate is bonded to one or both surfaces of the metallized substrate by brazing or the like. Further, the substrate to which the metal plate is joined may be mounted on the metal member by brazing or the like. The above brazings may be performed in one step.

The thermal resistance of the ceramic package of the present invention manufactured by the above method is lower than that of the conventional package using only BeO, and it is possible to mount a higher output element and use inexpensive Cu. It can be manufactured at low cost.

Hereinafter, the present invention will be described in more detail with reference to examples, but the following disclosure is merely examples of the present invention and does not limit the technical scope of the present invention.

[0018]

1 to 5 and 7 show high thermal conductive ceramics packages for semiconductors of the present invention having different configurations. 1 (a), 2 (a), 3 (a), 4 (a), 5
1A and FIG. 7A are perspective views of the high thermal conductive ceramics package for semiconductors according to the present invention.
(b), FIG. 2 (b), FIG. 3 (b), FIG. 4 (b), FIG. 5 (b) and FIG.
(b) are respectively FIG. 1 (a), FIG. 2 (a), FIG. 3 (a), and FIG.
FIG. 8A is a cross-sectional view taken along the arrows shown in FIGS. 5A and 7A.

1A and 1B show a first embodiment of the ceramic package of the present invention. The ceramic package of FIGS. 1 (a) and 1 (b) has four semiconductor elements 4 on the upper surface.
AlN substrate 1 on which is mounted, Cu plate 2 joined to the lower surface of AlN substrate 1, and Cu—W alloy metal member 3 on which they are mounted.
With. In the vicinity of the central portion of the metal member 3, the metal member 3
Two grooves 31 are provided across the ridge to allow the mounting portion 32 to
Are formed. The Cu plate 2 is brazed to the mounting portion 32 of the metal member 3. In addition, U is attached to both ends of the metal member 3.
A V-shaped notch is formed. When mounting the ceramics package on a wiring board or the like, the ceramics package is fixed to the board with a screw or the like by utilizing the cut.

Although not shown, the ceramic substrate 1
An electrode may be provided on the metal member 3 or on the metal member 3, and electrical wiring necessary for the semiconductor element 4 may be provided. Further, printed wiring may be provided on the ceramic substrate 1. Further, a cap that protects the semiconductor element 4 may be covered, and the cap may be provided with an electrode for electrically connecting the semiconductor element 4 to the outside.

In this embodiment, the AlN substrate 1 has a size of 10 mm ×
The size of Cu plate 2 is 10mm × 10mm × 0.35mm.
The dimensions of the metal member 3 were set to 12 mm × 28 mm × 1.5 mm.
Further, although AlN having a thermal conductivity of 180 W / mK is used for the substrate 1, a ceramic having sufficient thermal conductivity of 120 W / mK or more and having a sufficient insulating property, for example, any material such as SiC or BeO is used for the substrate 1. Can be used. On the other hand, the Cu plate 2 has a thermal conductivity
Cu of 300 W / mK or more or an alloy mainly composed of Cu can be used. Furthermore, for the metal member 3, a Cu-Mo alloy, Cu or the like having a thermal conductivity of 100 W / mK or more can be used.

2A and 2B show a second embodiment of the ceramic package of the present invention. The ceramic package shown in FIGS. 2A and 2B has four semiconductor elements 4 on the upper surface.
1. An AlN substrate 1 on which is mounted, a Cu plate 2 bonded to the upper surface of the AlN substrate 1 on which a semiconductor 4 is mounted, and a Cu—W alloy metal member 3 for mounting them. A hole corresponding to the semiconductor element 4 is opened in the Cu plate 2, the semiconductor element 4 is exposed from the hole, and is not in contact with the Cu plate 2.
The metal member 3 is the same as that shown in FIGS. 1 (a) and 1 (b).

In this embodiment, the AlN substrate 1 has a size of 10 mm ×
The size of the Cu plate 2 was 10 mm × 0.4 mm and the size of the Cu plate 2 was 10 mm × 10 mm × 0.2 mm. The thermal conductivity of the materials used is equal to that shown in Figures 1 (a) and (b). In the ceramic package of this embodiment, the Cu plate 2 for heat dissipation is bonded to the surface of the AlN substrate 1 on which the semiconductor 4 is mounted.
Thermal resistance is even lower than that shown in (a) and (b).

FIGS. 3A and 3B show a third embodiment of the ceramic package of the present invention. The ceramic package of FIGS. 3A and 3B has four semiconductor elements 4 on the upper surface.
AlN substrate 1 on which is mounted, Cu plate 2 joined to the lower surface of AlN substrate 1, and Cu—W alloy metal member 3 on which they are mounted.
With. In the ceramic package of this embodiment,
The central portion 33 of the metal member 3 has been cut and thinned,
The Cu plate 2 is fixed to the portion by brazing. Cu
The plate 2 is made of a thin and thick metal member 3.

In this embodiment, the AlN substrate 1 has a size of 10 mm ×
10mm × 0.2mm, Cu plate 2 size 10mm × 10mm × 0.8mm, metal member 3 size 12mm × 28mm, central part 33 thickness 1.1mm, other parts thickness 1.5mm And The thermal conductivity of the materials used is equal to that shown in Figures 1 (a) and (b). The ceramic package of the present embodiment has a high overall thermal conductivity, although the overall height is the same as that shown in FIGS. 1 (a) and 1 (b).
Is much thicker and therefore has a lower thermal resistance than that shown in FIGS. 1 (a) and (b).

FIGS. 4 (a) and 4 (b) show a fourth embodiment of the ceramic package of the present invention. The ceramic package of FIGS. 4 (a) and 4 (b) has four semiconductor elements 4 on the upper surface.
1. An AlN substrate 1 on which is mounted, a Cu plate 2 bonded to the upper surface of the AlN substrate 1 on which a semiconductor 4 is mounted, and a Cu—W alloy metal member 3 for mounting them. A hole corresponding to the semiconductor element 4 is opened in the Cu plate 2, the semiconductor element 4 is exposed from the hole, and is not in contact with the Cu plate 2.
The metal member 3 is equivalent to that shown in FIGS. 3 (a) and 3 (b).

In this embodiment, the AlN substrate 1 has a size of 10 mm ×
The size of the Cu plate 2 was 10 mm × 0.4 mm and the size of the Cu plate 2 was 10 mm × 10 mm × 0.2 mm. The thermal conductivity of the materials used is equal to that shown in Figures 1 (a) and (b). In the ceramic package of this example, the Cu plate 2 for heat dissipation is the same as the one shown in FIGS. Since it is bonded to the surface on which the semiconductor 4 is mounted, it has a sufficiently small thermal resistance.

5 (a) and 5 (b) show a fifth embodiment of the ceramic package of the present invention. The ceramic package of FIGS. 5A and 5B has four semiconductor elements 4 on the upper surface.
, An AlN substrate 1 on which is mounted, a Cu plate 21 bonded to the upper surface of the AlN substrate 1 on which the semiconductor 4 is mounted, a Cu plate 22 bonded to the lower surface of the AlN substrate 1, and a Cu-W mounting them. And an alloy metal member 3. A hole corresponding to the semiconductor element 4 is opened in the Cu plate 21, the semiconductor element 4 is exposed from the hole, and is not in contact with the Cu plate 21. Metal member 3
3A and 3B is similar to that shown in FIGS. 3A and 3B, the central portion 33 is cut to be thin, and the Cu plate 22 is formed in that portion.
Are fixed by brazing.

In this embodiment, the AlN substrate 1 has a size of 10 mm ×
The size of the Cu plate 21 is 10 mm × 10 mm × 0.2 mm, the size of the Cu plate 22 is 10 mm × 10 mm × 0.4 mm, the size of the metal member 3 is 12 mm × 28 mm, and the thickness of the central portion 33 is 10 mm × 0.2 mm. Is 1.3 mm,
The thickness of the other parts was 1.5 mm. The thermal conductivity of the materials used is equal to that shown in Figures 1 (a) and (b). The thermal conductivity of the materials used is equal to that shown in Figures 1 (a) and (b). In the ceramic package of the present embodiment, as compared with the one shown in FIGS. 1 (a) and 1 (b), since the Cu plates for heat dissipation are bonded to both sides of the AlN substrate 1, the thermal resistance is extremely high. small.

In the present embodiment, the Cu plate 21 bonded to the upper surface of the substrate 1 on which the semiconductor element 4 is mounted covers the entire upper surface of the substrate 1, but the ceramic having the structure shown in FIG. For packages, this is not necessary. That is, since the Cu plate 22 bonded to the lower surface of the substrate 1 secures a certain amount of heat dissipation, the Cu plate bonded to the upper surface of the substrate 1 is a semiconductor device as shown in FIG. 6 (a). Four
Even if the Cu plate 23 is configured to cover only the part where is mounted,
Further, as shown in FIG. 6B, a Cu plate 24 configured to form circuit wiring and the like may be used.

FIGS. 7A and 7B show a sixth embodiment of the ceramic package of the present invention. The ceramic package of FIGS. 7A and 7B has four semiconductor elements 4 on the upper surface.
AlN substrate 1 on which is mounted and Cu on which the AlN substrate 1 is directly mounted
The metal member 3 of FIG. In the vicinity of the central portion of the metal member 3, two grooves 31 are provided across the metal member 3, thereby forming a mounting portion 32 which is thicker than other portions. Al
The N substrate 1 is brazed to the mounting portion 32 of the metal member 3. Other configurations are the same as those shown in FIGS. 1 (a) and 1 (b).

In this embodiment, the AlN substrate 1 has a size of 10 mm ×
10mm x 0.2mm, the size of the metal member 3 is 12mm x 28mm,
The mounting portion 32 has a thickness of 1.8 mm, and the other portions have a thickness of 1.5 mm. The ceramics package of this example has no joint between the Cu plate and the metal member, and thus exhibits extremely good heat dissipation.
Further, in the ceramic package of this embodiment, it is particularly recommended to use an AlN substrate as the substrate 1. Since the AlN substrate can be easily thinned, even if the dimension from the upper surface of the metal member to the mounting portion of the semiconductor element is fixed from a mechanical point of view, the thickness of the substrate can be changed to change the metal member 3
This is because it can be applied while keeping the shape of the shape excellent in heat dissipation. On the other hand, the metal member 3 has a thermal conductivity of 300 W.
Cu or an alloy mainly composed of Cu of / mK or more can be used.

The high thermal conductive ceramics package for semiconductor of the present invention shown in FIGS. 1, 2, 3, 5, and 7 was produced. In each of the ceramic packages, an AlN substrate obtained by metallizing a paste containing a refractory metal was used as the substrate 1. In the case of the ceramic packages shown in FIGS. 1, 2, 3 and 5, a Cu plate was brazed to this AlN substrate by Ag—Cu brazing.

The substrate 1 to which the Cu plate was joined was further brazed to the metal member 3 of Cu-W alloy by Ag-Cu brazing. On the other hand, in the ceramic package of FIG. 7, the AlN substrate was directly brazed to the Cu metal member 3 by Ag-Cu solder. A Si chip as a semiconductor element 4 was brazed at 420 ° C. on each substrate 1 bonded to the above metal member 3 to complete the high thermal conductive ceramics package for semiconductors of the present invention.

The Si chip of each ceramic package was heated to measure the thermal resistance of the package. As a comparative example, a BeO substrate having a thickness of 0.6 mm was directly brazed to a Cu-W metal member which is the same as the ceramic package of the present invention, and a metal member having a thermal conductivity of 100.
The thermal resistance of the package manufactured in the same shape as the sample 1 using the WC-Co alloy having W / mK was also measured. The results are also shown in Table 1.

[0036]

[Table 1]

As shown in Table 1, the Cu plate 2 is the AlN substrate 1
And the Cu plate 2 is joined to the Cu-W alloy metal member 3
The ceramic package of the present invention configured to be bonded to has better thermal characteristics than the conventional ceramic package in which the BeO substrate is directly bonded to the Cu—W alloy metal member 3. In addition, the Cu plate bonded to the upper surface of the AlN substrate 1 on which the semiconductor element 4 is mounted has more excellent thermal characteristics. On the other hand, it was found that the one using the WC-Co alloy for the metal member was extremely poor in heat dissipation and poor in practicality.

[0038]

As described above in detail, the high thermal conductive ceramics package for semiconductors according to the present invention is manufactured by using an AlN substrate or a Be substrate.
The thermal resistance is reduced by the characteristic configuration of joining the Cu plate to the O substrate. According to the present invention, a package capable of mounting a high output device is provided.

[Brief description of drawings]

FIG. 1A is a perspective view of a first embodiment of a high thermal conductive ceramics package for semiconductors of the present invention, and FIG.
[FIG. 7] is a cross-sectional view taken along the plane indicated by the arrow in (a).

FIG. 2 (a) is a perspective view of a second embodiment of the high thermal conductive ceramics package for semiconductors of the present invention, and FIG.
[FIG. 7] is a cross-sectional view taken along the plane indicated by the arrow in (a).

FIG. 3 (a) is a perspective view of a third embodiment of the high thermal conductive ceramics package for semiconductors of the present invention, and FIG.
[FIG. 7] is a cross-sectional view taken along the plane indicated by the arrow in (a).

FIG. 4A is a perspective view of a fourth embodiment of the high thermal conductive ceramics package for semiconductors of the present invention, and FIG.
[FIG. 7] is a cross-sectional view taken along the plane indicated by the arrow in (a).

FIG. 5 (a) is a perspective view of a fifth embodiment of the high thermal conductive ceramics package for semiconductors of the present invention, and FIG.
[FIG. 7] is a cross-sectional view taken along the plane indicated by the arrow in (a).

6 (a) and 6 (b) are perspective views showing modifications of the upper Cu plate of the high thermal conductive ceramics package for semiconductors of the present invention.

FIG. 7 (a) is a perspective view of a sixth embodiment of the high thermal conductive ceramics package for semiconductors of the present invention, FIG.
[FIG. 7] is a cross-sectional view taken along the plane indicated by the arrow in (a).

[Explanation of symbols]

 1 Substrate 2, 21, 22 Cu plate 3 Metal member 4 Semiconductor element

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location H01L 23/12 301 J 23/14 23/373

Claims (7)

[Claims] 1. An AlN or BeO ceramics substrate on which a semiconductor element is mounted, and a surface of the ceramics substrate opposite to the side on which the semiconductor element is mounted are bonded and have a thickness equal to or larger than the thickness of the ceramics substrate. A high thermal conductive ceramics package for semiconductor, comprising a metal plate of Cu or an alloy mainly of Cu. 2. The high thermal conductivity for semiconductors according to claim 1, further comprising a metal plate of Cu or an alloy mainly composed of Cu bonded to a surface of the ceramics substrate on which a semiconductor element is mounted. Ceramic package. 3. A ceramic substrate of AlN or BeO on which a semiconductor element is mounted, and a metal plate of Cu or an alloy mainly containing Cu bonded to a surface of the ceramic substrate on which the semiconductor element is mounted. A high thermal conductivity ceramic package for semiconductors. 4. The high thermal conductive ceramics package for a semiconductor further comprises a metal member on which a ceramics substrate bonded with the metal plate is mounted, and the metal member is made of a metal having a thermal conductivity of 100 W / mK or more. The high thermal conductivity ceramics package for a semiconductor according to claim 1, wherein the high thermal conductivity ceramics package is used. 5. The metal member is made of a Cu—W alloy, a Cu—Mo alloy or Cu.
The high thermal conductive ceramics package for a semiconductor described in. 6. An AlN or BeO ceramic substrate on which a semiconductor element is mounted, and a metal member mounted by directly bonding the substrate, the metal member having a thermal conductivity of 100 W.
A high thermal conductive ceramics package for semiconductors, characterized in that it is made of a metal of at least / mK. 7. The metal member is made of Cu or an alloy mainly containing Cu, and a portion on which the ceramic substrate is mounted is thicker than other portions.
The high thermal conductive ceramics package for a semiconductor described in.