JP3482580B2 - High heat dissipation metal composite plate and high heat dissipation metal substrate using the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a highly heat-dissipating metal composite plate material suitable for incorporation in a ceramic package or the like, and a highly heat-dissipating metal substrate using the same.

[0002]

2. Description of the Related Art Conventionally, a supporting electrode of a semiconductor element and a mounting substrate have increased the amount of heat generated during use as the density of chips increases and the speed of data transmission increases. Such an increase in the amount of heat generation causes malfunction, deterioration, damage, etc. of the semiconductor element.

Therefore, it is desired to use, as a basic characteristic, a substrate material that has a high heat dissipation effect and that is as light as possible and that has a thermal expansion coefficient similar to that of the semiconductor element itself and its peripheral materials. . In addition to the semiconductor element itself, it is desirable to use a substrate material having a thermal expansion coefficient similar to that of the package material for incorporating the substrate in which the semiconductor element is mounted, or after assembly. In some cases, it may be desired to use a semiconductor element having a slightly different coefficient of thermal expansion with respect to the semiconductor element itself or its peripheral material in consideration of matching. Further, the substrate material is required to be easily attached and plated as a preparatory step for incorporating the substrate into a package. In addition, not only flat plates but also stepped types such as concave type and convex type are used for the substrates, so that it is required that the substrate material be easy to perform such step processing.

As a substrate material (plate material) having high heat dissipation capable of satisfying such requirements, a Cu-Mo composite material (TT-RCM) has been developed in recent years and has already been put into practical use.

[0005]

In the case of the Cu-Mo composite material (TT-RCM) described above, the recent demand for a substrate material for a semiconductor element, that is, a low thermal expansion coefficient, a high heat dissipation property, and a light weight. There is a problem that the requirement cannot be sufficiently satisfied.

[0006] Specifically, as shown in Table 1 below, several different Cu-Mo prepared by the powder mixing method are used.
Regarding the Cu-Mo based composite material (TT-RCM) characteristics of the mixing ratio, it can be understood that any of the above cannot satisfy the recent requirements for the substrate material such as poor heat dissipation if the coefficient of thermal expansion is low. .

[0007]

[Table 1]

From Table 1, it can be seen that, for example, when the content of copper (Cu) is 40 mass % or more, the thermal conductivity is high, but the thermal expansion coefficient is slightly large. Therefore, if such a Cu-Mo mixture ratio is used as the substrate material for incorporating the ceramic package, there is a risk that cracks or the like may occur due to mismatching with the ceramic package.

On the other hand, the content of copper (Cu) is 40
If the content is less than 10% by mass , the coefficient of thermal expansion is small, so that it has the advantage of good matching with a ceramic package when used as a substrate material for incorporating a ceramic package, but on the other hand, it has a low thermal conductivity. As a result, it is difficult to release the heat generated by the chip, and there is a risk of causing malfunctions, etc., and reliability is impaired.

That is, the conventional Cu-Mo composite material (TT
In the case of -RCM), recent requirements for a substrate material for a semiconductor element cannot be satisfied, and even when it is used as a substrate material for incorporation into a ceramic package, it has poor machinability and is difficult to apply.

By the way, a Cu-Mo composite material (TT-
Substrate materials other than RCM), that is, a thermal expansion coefficient of 8.5 ×
Copper-tungsten (CMSH) is known as a substrate material having a thermal conductivity of 200 W / m · K or more at 10 ⁻⁶ / ° C. or less, and this copper-tungsten (CMSH) has a density of 15.6 to 17. [G / cm ³ ] is large, it is difficult to realize weight reduction, and the machinability is poor. Therefore, as in the case of the Cu-Mo composite material (TT-RCM) described above, a recent semiconductor is used. It is not suitable for practical use as a device substrate material.

The present invention has been made to solve the above problems, and its technical problem is a high heat dissipation metal composite having a low coefficient of thermal expansion, high heat dissipation, light weight and excellent machinability. It is to provide a plate material and a highly heat-dissipating metal substrate using the same.

[0013]

According to the present invention, a metal alloy is formed.
Min is less than 40 wt% of copper (Cu) and the balance molybdenum
(Mo) and silicon carbide (SiC)
Add 0.5 to 5.3 [mass%] of the total mass to the
After the mixed powder molding, by sintering that, while being manufactured by rolling, the average thermal expansion coefficient of 6.0 to 8.5 [× 10
^A high heat dissipation metal composite plate material in the range of ⁻⁶ / ° C. can be obtained.

Further, according to the present invention, in the above high heat dissipation metal composite plate material, the thermal conductivity is 200 W / m · K or more .
High heat radiation metal composite plate material Ru Ah is obtained.

Furthermore, according to the present invention, there is obtained a highly heat-dissipating metal substrate in which a silicon semiconductor element is provided on a substrate obtained by stepping any of the above highly heat-dissipating metal composite plate materials.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION The high heat radiating metal composite plate material of the present invention and the high heat radiating metal substrate using the same will be described in detail below with reference to the drawings.

First, the outline of the high heat radiation metal composite plate material of the present invention will be briefly described. This highly heat-dissipative metal composite plate material contains copper (Cu) with a metal component of less than 40% by mass and the balance of the balance.
Made of ribden (Mo) and silicon carbide (SiC)
0.5 to 5.3 [mass%] in total mass with respect to the metal component
It is produced by molding the mixed powder obtained by adding , sintering, and rolling. The characteristics of this high heat dissipation metal composite plate material are
The average thermal expansion coefficient is in the range of 6.0 to 8.5 [× 10 ⁻⁶ / ° C.], the density is about 10 g / cm ³ or less, and the thermal conductivity is 200 W / m · K or more. There is.

If such a high heat radiation metal composite plate material is stepped by a stepping process to form a substrate and a silicon semiconductor element is provided on the substrate, high heat radiation property suitable for incorporation in a ceramic package is provided. It is configured as a metal substrate.

Therefore, the high heat radiation metal composite plate material having different material composition ratios (composition contents) will be specifically described below with reference to some examples, together with the manufacturing method thereof.

Example 1 In Example 1, first, molybdenum (Mo) powder, electrolytic copper (Cu) powder, and silicon carbide (SiC) powder were used as raw material powders at 70: 30: 3.1.
After mixing in a ratio of, and press-molding, sintering was performed in a hydrogen atmosphere. Next, this sintered body is heated to 900 ° C. in a hydrogen atmosphere.
After heating and holding for 15 minutes, the plate material having a thickness of 1.0 mm was finished by hot rolling and then cold rolling.

Then, various characteristics of this plate material were examined, and the coefficient of thermal expansion (α) was 7.5 × 10 ⁻⁶ / ° C., the thermal conductivity (κ) was 220 W / m · K, and the density (ρ) was 9.7 g / c
It was m ³ .

Further, after nickel (Ni) plating is formed on this plate material by electrolysis to have a film thickness of 3 μm, it is heat-treated in a hydrogen atmosphere at 850 ° C. for 20 minutes to form a film. As a result, the plating did not show any change such as swelling, discoloration, and stain, and no defect was observed.

By the way, as a comparison, various characteristics of a sheet material prepared by the same procedure with a molybdenum (Mo) powder: electrolytic copper (Cu) powder containing no silicon carbide (SiC): 70: 30 were examined. The coefficient (α) is 7.7 × 1
0 ^-6 / ° C., the thermal conductivity (kappa) is 190W / m · K, the density ([rho) was 9.7 g / cm ^3.

Example 2 In Example 2, as raw material powder, molybdenum (Mo) powder, electrolytic copper (Cu) powder, and silicon carbide (SiC) powder were mixed in a ratio of 70: 30: 4.2. After that, a plate material having a thickness of 1.0 mm was manufactured through the same procedure as in Example 1.

Then, when various characteristics of this plate material were examined, the coefficient of thermal expansion (α) was 7.3 × 10 ⁻⁶ / ° C., the thermal conductivity (κ) was 230 W / m · K, and the density (ρ) was 9.7 g / c
It was m ³ .

Further, here, as in the case of the first embodiment, Ni is used.
After the plating and heat treatment, the silicon wafer was further attached with silver tin (BAg-8). The Ni plating and silver tin adhesion workability was good, and defects such as cracks and peeling were not observed.

Incidentally, here as a comparison, silicon carbide (S
Molybdenum (Mo) powder without iC): electrolytic copper (C)
u) When the plate material produced with the powder of 70:30 was similarly subjected to the steps up to gluing, cracks were observed in the gluing portion, and it was found that the adhesion workability was poor.

<Example 3> In Example 3, molybdenum (Mo) powder, electrolytic copper (Cu) powder, and silicon carbide (SiC) powder were mixed at a ratio of 80: 20: 4.2 as raw material powder. A plate material having a thickness of 1 mm was manufactured through the same procedure as in Example 1.

Then, when various characteristics of this plate material were investigated, the thermal expansion coefficient (α) was 6.7 × 10 ⁻⁶ / ° C., the thermal conductivity (κ) was 210 W / m · K, and the density (ρ) was 9.8g / c
It was m ³ .

Also here, as in the second embodiment, Ni is used.
When we examined the adhesion processability by applying plating and silver sticking,
It was good.

Incidentally, here as a comparison, silicon carbide (S
Molybdenum (Mo) powder without iC): electrolytic copper (C)
u) Various properties of a plate material produced by the same procedure with the powder being 80:20 were examined, and the thermal expansion coefficient (α) was 6.9 × 10 ⁻⁶ / ° C. and the thermal conductivity (κ) was 175 W / m.・
The K and the density (ρ) were 9.9 g / cm ³ .

<Example 4> In Example 4, as raw material powders, molybdenum (Mo) powder, electrolytic copper (Cu) powder, and silicon carbide (SiC) powder were mixed at a ratio of 90: 10: 5.3. A plate material having a thickness of 1 mm was manufactured through the same procedure as in Example 1.

Then, various characteristics of this plate material were examined, and the coefficient of thermal expansion (α) was 6.0 × 10 ⁻⁶ / ° C., the thermal conductivity (κ) was 202 W / m · K, and the density (ρ) was 10.0 g /
It was cm ³ .

Incidentally, here as a comparison, silicon carbide (S
Molybdenum (Mo) powder without iC): electrolytic copper (C)
u) Various properties of a plate material produced by the same procedure with 90:10 powder were examined, and the coefficient of thermal expansion (α) was 6.2 × 10 ⁻⁶ / ° C. and the thermal conductivity (κ) was 163 W / m.・
The K and the density (ρ) were 10.0 g / cm ³ .

With respect to the SiC powder used in each of the above Examples (1 to 4), the particle size is 1 to 3 [μm], and various characteristics have a density (ρ) of 2.5 g / cm ³ , Coefficient of thermal expansion (α) is 3.1 × 10 ^-6 / ° C, thermal conductivity (κ) is 28
It is 0 W / m · K.

From each of the examples (1 to 4), the Cu content was regulated to less than 40 mass % when the Cu-Mo composite material (TT-RCM) was produced by the known powder mixing method, and 5-5 . It can be seen that, when 3 [ mass %] of SiC powder is added to obtain a high heat dissipation metal composite plate material, weight reduction and low thermal expansion are realized, high heat dissipation is improved, and machinability is also improved. .

By the way, as shown in FIG. 1, each plate material obtained in each of the above-mentioned embodiments (1 to 4) is subjected to a convex step by step processing to form four different convex shapes. After manufacturing the stepped substrate 1, solder 3 is applied onto each of these convex stepped substrates 1.
After the silicon chips 2 are respectively provided by the above method to obtain four kinds of high heat dissipation metal substrates, a heat cycle test is performed in a state in which these high heat dissipation metal substrates are assembled in a ceramic package. No cracks were generated and no peeling from the bonding interface was observed. or,
It was also found that the heat dissipation in the actual assembled state was significantly improved compared to the conventional one.

[0038]

As described above, according to the present invention, the Cu-Mo composite material (TT-R) by the known powder mixing method is used.
In the production of CM), the Cu content is regulated to less than 40% by mass , and 0.5 to 5 . By adding 3 [ mass %] of SiC powder, a highly heat-dissipating metal composite plate material having a low coefficient of thermal expansion, high heat dissipation, light weight, and excellent machinability can be obtained. In addition, if this high heat-dissipating metal composite plate material is used as a substrate material to make a step and a substrate is manufactured and a silicon semiconductor element is provided on the substrate, it is particularly suitable for incorporation into a ceramic package and effective heat dissipation is high. A metal substrate can be obtained.

[Brief description of drawings]

FIG. 1 is a side view showing a basic configuration of a highly heat-dissipating metal substrate according to an embodiment configured by using the highly heat-dissipating metal composite plate material of the present invention.

[Explanation of symbols]

1 Convex stepped substrate 2 silicon chips 3 solder

─────────────────────────────────────────────────── ─── Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) C22C 1/00-49/14 B22F 1/00-9/30 H01L 23/373

Claims (3)

(57) [Claims] 1. Copper (Cu) having a metal content of less than 40% by mass.
And the balance molybdenum (Mo), and silicon carbide
The total mass of (SiC) is 0.5 to 5.
After molding and sintering the mixed powder formed by adding 3 [mass%] ,
A highly heat-dissipating metal composite plate material, which is produced by rolling and has an average coefficient of thermal expansion of 6.0 to 8.5 [× 10 ⁻⁶ / ° C.]. 2. A method according to claim 1 in a high heat radiation metal composite plate material according, high heat radiation metal composite plate material thermal conductivity, characterized in der Rukoto least 200W / m · K. 3. A high heat radiation metal substrate, comprising a silicon semiconductor element provided on a substrate obtained by stepping the high heat radiation metal composite plate material according to claim 1 or 2.