TW201306195A - Heat sink substrate - Google Patents

Abstract

A heat dissipating substrate (1) comprises a first metal-diamond composite layer (11), a second metal-diamond composite layer (12), and a core material layer (10) disposed between the first metal-diamond composite layer (11) and the second metal-diamond composite layer (12). The first metal-diamond composite layer (11) and second metal-diamond composite layer (12) each have a diamond content of less than 50% by volume. The core layer (10) has a coefficient of thermal expansion in a direction parallel to a main surface of 4.5 10-6 K-1 - 13 10-6 K-1 and a thermal conductivity of 140 Wm-1K-1 or greater in the direction of thickness. Thus, a low-cost heat dissipating substrate having a coefficient of thermal expansion and high thermal conductivity suitable for mounting or holding a semiconductor element is provided.

Description

Heat sink substrate

The present invention relates to a heat dissipating substrate having a low thermal conductivity suitable for mounting or holding a semiconductor element and a high thermal conductivity.

In recent years, a substrate for mounting or holding a semiconductor element has been proposed in a wide variety of heat-dissipating substrates for efficiently dissipating heat accumulated on a high-density semiconductor element.

For example, Japanese Laid-Open Patent Publication No. Hei 10-12767 (Patent Document 1) discloses that the first layer is made of copper, the second layer is made of molybdenum or copper-molybdenum composite material, and the third layer is accumulated in the order of copper. The interface between the first layer and the second layer and the interface between the second layer and the third layer have an accumulation structure of a silver layer.

Japanese Laid-Open Patent Publication No. Hei 06-268117 (Patent Document 2) discloses a first member comprising at least one selected from the group consisting of a tungsten-copper alloy and a molybdenum-copper alloy, And a heat dissipation substrate bonded to the second surface of the first member and the other surface of the first member and made of copper.

Further, WO2003/040420 (Patent Document 3) discloses a method in which the diamond particles are contained in an amount of 60% by volume to 90% by volume based on the entire sintered body, and the remaining portion is substantially made of copper. Diamond sintered body.

[First technical literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 10-12767

[Patent Document 2] Japanese Patent Laid-Open No. 06-268117

[Patent Document 3] WO2003/040420

However, the heat-dissipating substrate disclosed in Japanese Laid-Open Patent Publication No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. No. 06-268117 (Patent Document 2) has a thermal expansion coefficient suitable for mounting or holding a semiconductor element. There is a problem that the thermal conductivity may not be higher.

In addition, the high thermal conductivity diamond sintered body disclosed in WO2003/040420 (Patent Document 3) has a thermal expansion coefficient suitable for mounting or holding a semiconductor element, and has a high thermal conductivity, but the diamond content of the sintered body is high. It is 60% by volume higher and has a manufacturing method, so there is a problem that the manufacturing cost is very high.

An object of the present invention is to solve the above problems and to provide a heat dissipating substrate which is suitable for mounting or holding a thermal expansion coefficient of a semiconductor element and a high thermal conductivity and which is low in price.

In order to solve the above problems, the inventors have found that by using a metal diamond composite having a diamond content of less than 50% by volume, it is possible to inexpensively manufacture a heat-radiating substrate having a high thermal conductivity, and further, by using the metal-diamond composite and the like The core material of the material is laminated to adjust the coefficient of thermal expansion, whereby the present invention can be completed. That is, the technical means of the present invention is as follows.

When the present invention complies with a certain situation, it is a heat dissipation substrate comprising: a first metal diamond composite layer; a second metal diamond composite layer; and a core material layer disposed in the first metal diamond composite layer and the second metal diamond composite Between the layers, the first metal diamond composite layer and the second metal diamond composite layer have a diamond content of less than 50% by volume, and the core layer is thermally expanded in a direction parallel to the main surface. The coefficient is 4.5X10 ^-6 K ^-1 ~13 X10 ^-6 K ^-1 , and the thermal conductivity in the thickness direction is greater than 140W. m ^-1 . K ^-1 .

In the heat-dissipating substrate of the present invention, the heat-dissipating substrate has a thermal expansion coefficient of 7×10 ^-6 K ^-1 to 13 X10 ^-6 K ^-1 in a direction parallel to the main surface, and a thermal conductivity of more than 400 W in the thickness direction. m ^-1 . K ^-1 . Further, the entire heat dissipation substrate may have a thickness of 500 μm to 10000 μm. Further, the core material layer (10) may have a thickness of 50 μm to 4000 μm. Also, the core material layer (10) may comprise molybdenum.

Further, the diamond particles included in the first metal diamond composite layer and the second metal diamond composite layer may have a particle diameter of 20 μm to 250 μm.

When the present invention is used, it is possible to provide a heat-dissipating substrate having a low thermal conductivity suitable for mounting or holding a semiconductor element and a high thermal conductivity.

[heat sink substrate]

Referring to Fig. 1, a heat dissipation substrate 1 according to an embodiment of the present invention includes: a first metal diamond composite layer 11; a second metal diamond composite layer 12; and a core material layer 10 disposed on the first metal diamond composite layer 11 and Between the metal diamond composite layers 12, the first metal diamond composite layer 11 and the second metal diamond composite layer 12 have a diamond content of less than 50% by volume, and the core material layer 10 is parallel to the main surface. The coefficient of thermal expansion is 4.5X10 ^-6 K ^-1 ~13 X10 ^-6 K ^-1 , and the thermal conductivity in the thickness direction is greater than 140W. m ^-1 . K ^-1 .

The heat dissipation substrate 1 of the present embodiment includes the first metal diamond composite layer 11 and the second metal diamond composite layer 12 each having a diamond content of less than 50% by volume. Therefore, the manufacturing cost is low and has more than 400 W. m ^-1 . High thermal conductivity of K ^-1 . Moreover, the heat dissipation substrate 1 of the present embodiment has a thermal expansion coefficient in the direction parallel to the main surface of 4.5×10 ^-6 K ^-1 to 13 X10 ^-6 K ^-1 , and the thermal conductivity in the thickness direction is greater than 140 W. m ^-1 . Since the core material layer 10 of K ^{-1 is} the same or similar to the thermal expansion coefficient of the semiconductor element, it is suitable for mounting or holding of a semiconductor element.

The heat dissipating substrate 1 of the present embodiment preferably has a thermal expansion coefficient of 7×10 ^-6 K ⁻¹ to 13 X10 ^-6 K ⁻¹ in a direction parallel to the main surface thereof, and the thermal conductivity in the thickness direction is greater than 400 W. m ^-1 . K ^-1 . Further, the upper limit of the thermal conductivity in the entire thickness direction of the heat dissipation substrate 1 of the present embodiment is now 600 W. m ^-1 . K ^-1 or so. Here, the thermal expansion coefficient and the thermal conductivity of the entire heat dissipation substrate 1 mean the thermal expansion coefficient and the thermal conductivity when the entire heat dissipation substrate 1 is integrated. The heat dissipating substrate 1 having the thermal expansion coefficient and the thermal expansion coefficient ratio in the relevant range is the same as or similar to the thermal expansion coefficient of the semiconductor element, and has a high thermal conductivity, so that it is very suitable for mounting or holding a semiconductor element. The heat sink substrate.

The entire heat dissipation substrate 1 of the present embodiment preferably has a thickness of 500 μm to 10000 μm. When the thickness T is less than 500 μm, the heat dissipation performance of the entire heat dissipation substrate 1 is lowered. When the thickness T exceeds 10000 μm, it is difficult to mount or hold the semiconductor element at a high density, and it is not suitable as a substrate for assembly.

(core layer)

The core layer 10 of the heat dissipation substrate 1 of the present embodiment is disposed between the first metal diamond composite layer 11 and the second metal diamond composite layer 12. The first metal diamond composite layer 11 and the second metal diamond composite layer 12 have a high thermal conductivity and a thermal expansion coefficient larger than that of the semiconductor element. Therefore, it is not suitable for mounting or holding a semiconductor element alone. Therefore, in order to make the thermal expansion coefficient of the entire heat dissipation substrate 1 the same or similar to the thermal expansion coefficient of the semiconductor element, the core material layer 10 is necessary.

From the above point of view, the core material layer 10 must have a coefficient of thermal expansion parallel to the main surface of 4.5X10 ^-6 K ^-1 ~13 X10 ^-6 K ^-1 , and the thermal conductivity in the thickness direction is greater than 140W. m ^-1 . K ^-1 . Moreover, the upper limit of the thermal conductivity of the core material layer 10 in the thickness direction is now 250 W. m ^-1 . K ^-1 or so.

The core material layer 10 is not particularly limited as long as it has the above thermal expansion coefficient and thermal conductivity, and may be a single layer composed of one layer or a multiple layer composed of a plurality of layers. Further, in the single layer, the monomer layer composed of a single chemical species may be used, or a composite layer composed of a plurality of chemical species may be used. Here, the monomer layer is preferably a molybdenum layer, a tungsten layer, an AlN layer, a Si ₃ N ₄ layer, or the like. The composite layer is preferably a CuW layer or a CuMo layer. Further, the double layer may be a Mo/X/Mo layer (X is selected from at least one of a group consisting of Cu, Ag, Cu diamond, and Ag diamond), and a Mo/X/MO/X/Mo layer (X). It is suitable for at least one selected from the group consisting of Cu, Ag, Cu diamonds and Ag diamonds. Further, when the insulating core material layer 10 such as an AlN layer or a Si ₃ N ₄ layer is used, insulation properties can be imparted in the thickness direction of the heat dissipation substrate 1.

Further, the core material layer 10 is not particularly limited as long as it has the above thermal expansion coefficient and thermal conductivity, and is preferably a molybdenum-containing layer, specifically, a Mo layer, a CuMo layer, and a Mo/X/Mo layer (X-based from Cu). , at least one selected from the group consisting of Ag, Cu, and Ag diamonds), Mo/X/MO/X/Mo layer (X is selected from the group consisting of Cu, Ag, Cu, and Ag diamonds) At least one) is better.

Further, on the surface of the core material layer 10, the metal layer may be formed by at least one of plating or evaporation. The metal layer may be suitably a nickel layer, a copper layer, a silver layer, a gold layer, or a layer formed by laminating these metals.

Further, the thickness T _{0 of the} core material layer 10 is not particularly limited, but is preferably 50 μm to 4000 μm, and more preferably 250 μm to 1000 μm. When the thickness T _{0 of the} core material layer 10 is less than 50 μm, the coefficient of thermal expansion of the entire heat dissipation substrate 1 in the direction parallel to the main surface is difficult to be 7×10 ^-6 K ^-1 to 13 X10 ^-6 K ^-1 , when the core layer when the thickness T ₀ 10 is greater than 4000μm, 1 thermal conductivity in the thickness direction of the substrate is difficult to heat the whole of greater than 400W. m ^-1 . K ^-1 .

(1st and 2nd metal diamond composite layers)

In the heat dissipation substrate 1 of the present embodiment, the first metal-diamond composite layer 11 is disposed on the main surface side of the core material layer 10, and the second metal diamond composite layer 12 is disposed on the main surface side of the other side of the core material layer 10. . Therefore, the heat dissipation substrate 1 having a high thermal conductivity can be obtained. The first metal diamond composite layer 11 and the second metal diamond composite layer 12 have a diamond content of less than 50% by volume, and the viewpoint of reducing the manufacturing cost from the viewpoint of the punching process by the punch and the reduction of the manufacturing cost. Good is less than 40% by volume. Moreover, the first metal diamond composite layer 11 and the second metal diamond composite layer 12 have a diamond content of more than 10% by volume, whereby the respective thermal conductivity can exceed 420 W. m ^-1 . K ^-1 . Moreover, since the first metal diamond composite layer 11 and the second metal diamond composite layer 12 have a diamond content of less than 50% by volume, respectively, the thermal conductivity is less than 700 W. m ^-1 . K ^-1 .

Here, as described above, the core material layer 10 in the heat dissipation substrate 1 of the present embodiment has a thermal expansion coefficient in the direction parallel to the main surface of 4.5×10 ^-6 K ^-1 to 13 X10 ^-6 K ^-1 , and its thermal expansion The coefficients are the same or similar to the thermal expansion coefficient of the semiconductor element, so it is suitable for mounting or holding the semiconductor element, but the thermal conductivity in the thickness direction is greater than 140W. m ^-1 . The heat sink substrate of K ^-1 preferably has a higher thermal conductivity. Therefore, if the core material layer 10 is sandwiched between the first metal diamond composite layer 11 and the second metal diamond composite layer 12, the thermal conductivity in the thickness direction can be obtained to be greater than 400 W. m ^-1 . K ^-1 , and the heat-dissipating substrate 1 having a lower cost is manufactured.

The first metal diamond composite layer 11 and the second metal diamond composite layer 12 are layers formed of a composite of a metal and a diamond, and have a form in which diamond particles are dispersed in a metal, for example. Although the metal is not particularly limited, it is suitable for use from the viewpoint of high thermal conductivity, using copper, silver, and aluminum. That is, a copper diamond composite layer, a silver diamond composite layer, an aluminum diamond composite layer, and the like can be exemplified. Moreover, although the particle size of the diamond particles is not particularly limited, From the viewpoint of improving workability, it is preferably more than 20 μm, and from the viewpoint of improving uniform dispersibility in the metal, it is preferably not more than 250 μm.

Further, in the first metal diamond composite layer 11 and the second metal diamond composite layer 12, a metal layer formed by at least one of plating and evaporation may be formed on the surface. The metal layer may be suitably a nickel layer, a copper layer, a silver layer, a gold layer, or a layer formed by laminating these metals.

The first metal diamond composite layer 11 and the second metal diamond composite layer 12 have a diamond content of less than 50% by volume from the viewpoint of forming a layer having a high thermal conductivity at a low manufacturing cost. In particular, when the first metal diamond composite layer 11 and the second metal diamond composite layer 12 are formed by various discharge methods such as a cold discharge method, the diamond content is preferably 10% by volume to 50% by volume, and 10% by volume. ~40% by volume is more preferred. When the diamond content is less than 10% by volume, the ejection becomes unstable, and when the diamond content exceeds 50% by volume, bubbles are easily generated in the metal diamond composite layer at the time of ejection.

Here, the diamond content of the first metal diamond composite layer 11 and the diamond content of the second metal diamond composite layer 12 may be the same or different.

Further, the thickness T _{1 of the} first metal diamond composite layer 11 and the T _{2 of the} second metal diamond composite layer 12 may be the same or different.

In the heat dissipation substrate 1, the type and thickness T _{0 of the} core material layer 10, the diamond content rate and thickness T ₁ of the first metal diamond composite layer 11, and the diamond content rate and thickness T of the second metal diamond composite layer 12 are changed. ₂ , a heat dissipation substrate 1 having a desired thermal expansion coefficient and thermal conductivity can be obtained.

The heat dissipation substrate 1 is generally such that the diamond content of the first metal diamond composite layer 11 is the same as the diamond content of the second metal diamond composite layer 12, and the thickness T ₁ and the second metal of the first metal diamond composite layer 11 are made. The thickness T ₂ of the diamond composite layer 12 is the same, whereby the coefficient of thermal expansion parallel to the main surface is the same on the side of the first metal diamond composite layer 11 and the side of the second metal diamond composite layer 12.

The heat dissipation substrate 1 may have a diamond content ratio of the first metal diamond composite layer 11 different from that of the second metal diamond composite layer 12, and the thickness T of the first metal diamond composite layer 11 may be different depending on the purpose of use. ₁ is different from the thickness T ₂ of the second metal-diamond composite layer 12, whereby the coefficient of thermal expansion parallel to the main surface is different from the side of the first metal-diamond composite layer 11 and the second metal-diamond composite layer 12 side.

Further, the first metal diamond composite layer 11 and the second metal diamond composite layer 12 are preferably formed from the viewpoint of forming the heat dissipation substrate 1 having the same thermal expansion coefficient or similar to the thermal expansion coefficient of the semiconductor element and having high thermal conductivity. The coefficient of thermal expansion parallel to the main surface is 8.5X10 ^-6 K ^-1 ~15 X10 ^-6 K ^-1 , and the thermal conductivity in the thickness direction is greater than 420W. m ^-1 . K ^-1 .

[Method of Manufacturing Heat Dissipating Substrate]

The method of manufacturing the heat dissipation substrate of the present embodiment is not particularly limited, and for example, the step of preparing the core material layer 10 and the main surface side of the core material layer 10 may be formed to form the first metal diamond composite layer 11 in the core. The step of forming the second metal-diamond composite layer 12 on the main surface side of the other side of the material layer 10.

{Preparation process of core layer}

The prepared core material layer 10 is as described above and will not be repeated here.

{Process for forming the first and second metal diamond composite layers}

The formed first metal diamond composite layer 11 and the second metal diamond composite layer 12 are as described above, and are not repeated here.

The method of forming the first metal diamond composite layer 11 and the second metal diamond composite layer 12 is not particularly limited, and the first metal diamond composite layer 11 is directly formed on the main surface side of the core material layer 10, and the core metal layer 10 is formed. On the other side of the main surface, a direct method of directly forming the second metal diamond composite layer 12, and preparing the first metal diamond composite layer 11 and the second metal diamond composite layer 12 in advance, on the main surface side of the core material layer 10 The first metal diamond composite layer 11 is bonded to the main surface side of the other side of the core material layer 10, and the second metal diamond composite layer 12 is bonded to each other. From the viewpoint of forming the first metal diamond composite layer 11 and the second metal diamond composite layer 12 with high efficiency and low cost, it is preferable to adopt a direct method.

(direct method)

The direct method may be a discharge method such as a cold discharge method, an HVAF (High Velocity Aero Fuel) method, or an AD (Aerosol Deposition) method.

In the related discharge method, although it is not particularly limited, for example, a sub-process of preparing a metal diamond composition for discharge, and a main surface side of both sides of the core layer by ejecting the metal diamond composition, a pair of heat-dissipating substrates is obtained. Process.

(The sub-process of preparing the metal diamond composition for spraying)

First, prepare a metal diamond composition for ejection. The prepared metal diamond composition is a powder of metal-coated diamond particles formed by coating a metal film on the surface of the diamond particles, and metal particle powder is also added as needed. Here, although the metal film is not particularly limited, it is a viewpoint of improving the thermal conductivity. Point of view, it is suitable for copper film, silver film, aluminum film and so on. The metal particle powder to be added is not particularly limited, but a copper particle powder, a silver particle powder, an aluminum particle powder or the like is suitably used from the viewpoint of improving the thermal conductivity.

The diamond content of the metal diamond composition is preferably from 10% by volume to 50% by volume, and more preferably from 10% by volume to 40% by volume. When the diamond content is less than 10% by volume, the ejection becomes unstable, and when the diamond content exceeds 50% by volume, bubbles are easily generated in the metal diamond composite layer at the time of ejection.

The particle diameter of the diamond particles is not particularly limited, but is preferably 20 μm to 250 μm. When the particle diameter of the diamond particles is less than 20 μm, the supply of the ejection becomes unstable, and when the particle diameter of the diamond particles is larger than 250 μm, bubbles are easily generated. Further, the thickness of the metal film covering the diamond particles is not particularly limited, but is preferably 1 μm to 30 μm. When the thickness of the metal film is less than 1 μm, there is insufficient adhesion between the particles at the time of ejection, and when the thickness of the metal film is more than 30 μm, it is difficult to produce metal-coated diamond particles. Therefore, the particle diameter of the metal-coated diamond particles is not particularly limited, but it is preferably 21 μm to 280 μm from the above reasons.

Further, in the metal-coated diamond particles, another metal film (intermediate metal film) may be interposed between the diamond particles and the metal film. The related intermediate metal film is preferably at least one selected from the group consisting of Ti, V, Cr, Mn, Fe, Co, Ni, and a compound containing the above elements. The thickness of the intermediate metal film is not particularly limited, but is preferably 0.5 μm to 1.0 μm. When the thickness of the intermediate metal film is less than 0.5 μm, the heat conduction between the metal film and the diamond particles is lowered. When the thickness of the intermediate metal film is more than 1.0 μm, the thermal conductivity of the intermediate metal film itself is lowered. In the case of the case, there is a reduction in the thermal conductivity of the metal-diamond composite layer.

In the metal-coated diamond particles, a method of forming a metal film or forming an intermediate metal film and a metal film on the surface of the diamond particles is not particularly limited, and examples thereof include electroplating, metal foil bonding, and CVD (chemical vapor deposition). The method, the plasma CVD method, the MOCVD (organic metal chemical vapor deposition method), the evaporation method, and the discharge method are suitable.

Further, the metal diamond composition may be used as a diamond particle, and a powder of the intermediate metal-coated diamond particles and a metal particle powder in which the intermediate metal film is formed may be used.

(By spraying the metal diamond composition to the main surface side of both sides of the core layer, the sub-process of obtaining the heat-dissipating substrate)

Then, the prepared metal diamond composition is ejected onto the main surface side of the core material layer 10 to form the first metal diamond composite layer 11, and is discharged onto the main surface side of the other side of the core material layer 10 to form the second metal. Diamond composite layer 12. In this way, the heat dissipation substrate 1 in which the core material layer 10 is disposed between the first metal diamond composite layer 11 and the second metal diamond composite layer 12 can be obtained.

The method of ejecting the metal diamond composition is preferably a cold spray method, a HVAF (High Velocity Aero Fuel) method, or an AD (Aerosol Deposition) method.

The discharge conditions are not particularly limited as long as they are suitable for the metal diamond composition and the discharge method. For example, in the case of cold spray, the gas used for spraying may use an inert gas such as nitrogen, helium or argon, or a mixed gas of hydrogen mixed with the above inert gas, so that the pressure of the spray gas is 2 MPa to 5 MPa (2 MPa). ~4 MPa is better), it is best to make the spraying gas temperature 700 °C~1000°C (more preferably from 700°C to 900°C), so that the speed of metal-coated diamond particles and metal particles during spraying is 700m/s~1000 m/s. Here, the speed at which the metal is coated with the diamond particles and the metal particles during the spraying is calculated by the particle image captured by the CCD camera during the spraying.

In the heat-radiating substrate manufacturing method by the direct method, from the viewpoint of removing the oxide in the heat-dissipating substrate and improving the bonding force between the particles, it is preferable to further include a sub-step of heat-treating the obtained heat-dissipating substrate 1.

(Sub-process of heat treatment heat sink substrate)

In the sub-process of heat-treating the heat-dissipating substrate, it is preferable to use a non-oxidizing environmental gas containing a reducing gas, such as a hydrogen atmosphere gas, from the viewpoint of removing the oxide formed in the heat-dissipating substrate at the time of discharge. a mixture of hydrogen and nitrogen, ambient gas, and the like. The heat treatment temperature is preferably from 400 ° C to 600 ° C from the viewpoint of removing oxides in the heat-dissipating substrate and improving the bonding force between the particles. The heat treatment time is preferably from 0.2 hours to 1 hour from the viewpoint of removing the oxide in the heat-dissipating substrate and increasing the bonding force between the particles.

(indirect method)

The indirect method is not particularly limited, and includes, for example, a sub-process of forming a first metal diamond wafer (first metal diamond composite layer 11) and a second metal diamond wafer (second metal diamond composite layer 12), and The first metal diamond wafer (the first metal diamond composite layer 11) and the second metal diamond wafer (the second metal diamond composite layer 12) are bonded to the main surface sides on both sides of the core material layer 10, thereby obtaining Sub-process of heat-dissipating the substrate.

(Formal worker who forms the first metal diamond wafer and the second metal diamond wafer sequence)

The method of forming the first metal diamond wafer (the first metal diamond composite layer 11) and the second metal diamond wafer (the second metal diamond composite layer 12) is not particularly limited, but may be, for example, a sintering method or a melt immersion method. The method, the HP (hot pressing) method, the electrification sintering method, and the calendering method are suitable.

The first metal diamond wafer (the first metal diamond composite layer 11) and the second metal diamond wafer (the second metal diamond composite layer 12) are formed of a wafer comprising a composite of metal and diamond. For example, there is a form in which diamond particles are dispersed in a metal. The metal is not particularly limited, but from the viewpoint of improving the thermal conductivity, it is suitable to use copper, silver, aluminum, and the like. That is, a copper-diamond composite wafer, a silver-diamond composite wafer, and an aluminum-diamond composite wafer can be exemplified. In addition, the particle diameter of the diamond particles is not particularly limited, but is preferably more than 20 μm from the viewpoint of improving workability, and is preferably less than 250 μm from the viewpoint of improving uniform dispersibility in the metal.

The first metal diamond wafer (the first metal diamond composite layer 11) and the second metal diamond wafer (the second metal diamond composite layer 12) form a first metal diamond composite having a high thermal conductivity at a low manufacturing cost. From the viewpoint of the layer 11 and the second metal diamond composite layer 12, the diamond content is preferably 10% by volume to 50% by volume, and more preferably 10% by volume to 40% by volume. When the diamond content is less than 10% by volume, a wafer having a high thermal conductivity cannot be obtained. When the diamond content is more than 50% by volume, a high pressure is required in manufacturing a wafer, so the manufacturing cost becomes high.

Here, the diamond content of the first metal diamond wafer (the first metal diamond composite layer 11) is combined with the second metal diamond wafer (the second metal diamond) The diamond content of layer 12) may be the same or different.

Here, the diamond content of the first metal diamond wafer (the first metal diamond composite layer 11) and the metal diamond composition of the second metal diamond wafer are not particularly limited, but From the viewpoint of improving workability and formability, it is suitable to use the metal diamond composition in the above direct method.

Further, the thickness of the first metal diamond wafer (the first metal diamond composite layer 11) of the T ₁ and the second metal diamond wafer thickness (the second metal diamond composite layer 12) of the T _2, may be the same or may be different .

(The first metal diamond wafer and the second metal diamond wafer are bonded to each other on the main surface side of the core material layer, thereby obtaining a sub-process of the heat dissipation substrate)

Next, the first metal diamond wafer (the first metal diamond composite layer 11) is bonded to the main surface side of the core material layer 10, and the second metal diamond crystal is bonded to the main surface side of the other side of the core material layer 10. Round (2nd metal diamond composite layer 12). In this way, the heat dissipation substrate 1 in which the core material layer 10 is disposed between the first metal diamond composite layer 11 and the second metal diamond composite layer 12 can be obtained.

The method of bonding the first metal diamond wafer (the first metal diamond composite layer 11) and the second metal diamond wafer (the second metal diamond composite layer 12) to the core material layer 10 is not particularly limited, however, A wax soldering method, an HP method, a calendering method, an electric current sintering method, and a combination of the above methods are all suitable.

Example

[Example 1]

(Example 1-1)

1. Prepare the core layer

Referring to Fig. 1, the core material layer 10 is prepared with a core material having a diameter of 2 inches (5.08 cm) and a thickness of 500 μm (molybdenum purity of 99.9% by mass) (coefficient of thermal expansion α: 5.2×10 ^-6 K ^-1 , thermal conductivity) κ: 142 W.m ^-1 .K ^-1 ).

2. Making a heat-dissipating substrate made of the first and second metal diamond composite layers

On the main surface on both sides of the molybdenum core material (core material layer 10), a copper diamond composition (metal diamond composition) is sprayed by cold spray method, thereby forming a first copper diamond wafer (first metal diamond composite) Layer 11), and the second copper diamond wafer (second metal diamond composite layer 12). More specifically, it is as follows.

The copper diamond composition (metal diamond composition) is a commercially available titanium-coated diamond particle (DI (diamond innovation) coated with diamond particles having an average particle diameter of 100 μm and a purity of 99.9% by mass and coated with a titanium layer having a thickness of 0.5 μm to 1.0 μm. a powder of copper/titanium-coated diamond particles (metal-coated diamond particles) having an electroless copper plating layer of 10 μm and a powder of electrolytic copper (metal) particles having an average particle diameter of 100 μm on a MBG600 100 μ TI manufactured by the company. The diamond content in the entire composition was 30% by volume.

On the main surface of the molybdenum core material (core material layer 10) on one side and the other side, the copper diamond composition (metal diamond composition) is cold-sprayed, thereby forming a first copper diamond wafer (first metal) having a thickness of 600 μm. The diamond composite layer 11) and the second copper diamond wafer (the second metal diamond composite layer 12) having a thickness of 600 μm. In this way, the first copper diamond wafer (the first metal diamond composite layer 11) and the second copper diamond wafer (the second metal diamond composite layer 12) can be obtained. A heat-dissipating substrate 1 having a thickness of 1700 μm of a molybdenum core material (core material layer 10) was disposed between them.

In the cold spray of the copper diamond composition (metal diamond composition), the spray gas is nitrogen gas, the spray gas pressure is 4 MPa, the spray gas temperature is 800 ° C, and the copper/titanium coated diamond particles (metal coated diamond particles) during spraying and The speed of the copper particles (metal particles) was 800 m/s.

3. Heat treatment of the heat sink substrate

The obtained heat-dissipating substrate 1 was heat-treated at 600 ° C for 1 hour in a hydrogen atmosphere gas.

4. Evaluation of heat sink substrate

The thermal expansion coefficient α of the heat-dissipating substrate 1 obtained in the above-mentioned process parallel to the main surface direction is a sample of 4 mm×20 mm×1700 μm thickened from the heat-dissipating substrate, in the range of 25° C. to 200° C., and has the same embodiment. The obtained heat-dissipating substrate is melted by the same element composition, and the prepared copper tungsten (copper: 20% by mass, tungsten 80% by mass, thermal expansion coefficient α: 8.3 X10 ^-6 K ^-1 , thermal conductivity κ: 200 W.m) ^-1 .K ^-1 ) is used as a reference material and is measured by a comparative measurement method. It is 8.5X10 ^-6 K ^-1 and is suitable for mounting or holding semiconductor components. Further, the thermal conductivity κ in the thickness direction of the heat-dissipating substrate 1 is a sample having a diameter of 10 mm and a thickness of 1,700 μm which is cut out from the heat-dissipating substrate, and is measured by a laser flash method, which is a very high 408 W. m ^-1 . K ^-1 . Moreover, the joint strength of the copper-diamond composite layer (metal diamond composite layer) and the molybdenum core material (core material layer) is a copper diamond composite layer (metal diamond composite layer) and a molybdenum core material having a diameter of 2 inches (5.08 cm). The joined body of the (core material layer) was a very large 0.56 GPa when subjected to a tensile test. The results are shown in Table 1.

(Example 1-2)

The thickness of the core material layer was 300 μm, and the particle diameter of the diamond particles in the first and second metal diamond composite layers was 250 μm, and the diamond content was 8% by volume. Further, the same heat dissipation substrate as in Example 1-1 was produced. The obtained heat-dissipating substrate has a thickness of 1500 μm and a thermal expansion coefficient α of 14.2 X10 ^-6 K ^-1 , which is suitable for mounting or holding semiconductor components, and the thermal conductivity κ is very high at 390 W. m ^-1 . K ^-1 , the joint strength of the metal diamond composite layer and the core layer is extremely large 0.69 GPa. In Example 1-2, the diamond content rate is lower than the desired range. Therefore, the thermal expansion coefficient α of the heat dissipation substrate is higher than the desired range, and the thermal conductivity κ of the heat dissipation substrate is lower than the desired range. The results are summarized in Table 1.

(Example 1-3)

The amount of diamond in the first and second metal diamond composite layers was 10% by volume, and the same heat dissipation substrate as in Example 1-2 was produced. The obtained heat-dissipating substrate has a thickness of 1500 μm and a thermal expansion coefficient α of 13.0×10 ^-6 K ^-1 , which is suitable for carrying or holding a semiconductor element, and the thermal conductivity κ is very high 409 W. m ^-1 . K ^-1 , the joint strength of the metal diamond composite layer and the core layer is 0.60 GPa. The results are summarized in Table 1.

(Example 1-4)

The content of the diamond in the first and second metal diamond composite layers was 20% by volume, and the same heat dissipation substrate as in Example 1-2 was produced. The obtained heat-dissipating substrate has a thickness of 1500 μm and a thermal expansion coefficient α of 11.4×10 ^-6 K ^-1 , which is suitable for mounting or holding a semiconductor element, and has a thermal conductivity κ of 441 W. m ^-1 . K ^-1 , the joint strength of the metal diamond composite layer and the core layer is extremely large 0.57 GPa. The results are summarized in Table 1.

(Example 1-5)

The content of the diamond in the first and second metal diamond composite layers was 30% by volume, and the same heat dissipation substrate as in Example 1-2 was produced. The obtained heat-dissipating substrate has a thickness of 1500 μm and a thermal expansion coefficient α of 8.5×10 ^-6 K ^-1 , which is suitable for mounting or holding semiconductor components, and the thermal conductivity κ is 478 W. m ^-1 . K ^-1 , the joint strength of the metal diamond composite layer and the core layer is extremely large 0.56 GPa. The results are summarized in Table 1.

(Example 1-6)

The amount of diamond in the first and second metal diamond composite layers was 40% by volume, and the same heat dissipation substrate as in Example 1-2 was produced. The obtained heat-dissipating substrate has a thickness of 1500 μm and a thermal expansion coefficient α of 8.1×10 ^-6 K ^-1 , which is suitable for mounting or holding semiconductor components, and the thermal conductivity κ is very high 521 W. m ^-1 . K ^-1 , the joint strength of the metal diamond composite layer and the core layer is extremely large 0.56 GPa. The results are summarized in Table 1.

(Example 1-7)

The amount of diamond in the first and second metal diamond composite layers was 50% by volume, and the same heat dissipation substrate as in Example 1-2 was produced. The obtained heat-dissipating substrate has a thickness of 1500 μm and a thermal expansion coefficient α of 7.2×10 ^-6 K ^-1 , which is suitable for carrying or holding a semiconductor element, and has a thermal conductivity κ of 374 W. m ^-1 . K ^-1 , the joint strength of the metal diamond composite layer and the core layer is extremely large 0.57 GPa. In Example 1-7, since the diamond content rate is too high, the heat conductivity κ of the heat dissipation substrate becomes small. The results are summarized in Table 1.

(Example 1-8)

The particle diameter of the diamond particles in the first and second metal diamond composite layers was 300 μm, and a heat dissipation substrate similar to that of Example 1-7 was produced. The obtained heat-dissipating substrate has a thickness of 1500 μm and a thermal expansion coefficient α of 6.8×10 ^-6 K ^-1 , which is suitable for mounting or holding a semiconductor element, and has a thermal conductivity κ of 320 W. m ^-1 . K ^-1 , the joint strength of the metal diamond composite layer and the core layer is extremely large 0.56 GPa. In Example 1-8, the diamond content ratio is too high, and the particle size of the diamond particles is larger than the desired range. Therefore, the thermal expansion coefficient α of the heat dissipation substrate is lower than the desired range, and the heat dissipation substrate is The thermal conductivity κ is lower than the expected range. The results are summarized in Table 1.

(Example 1-9)

The particle diameter of the diamond particles in the first and second metal diamond composite layers was set to 100 μm, and a heat dissipation substrate similar to that of Example 1-5 was produced. The obtained heat-dissipating substrate has a thickness of 1500 μm and a thermal expansion coefficient α of 8.5×10 ^-6 K ^-1 , which is suitable for mounting or holding semiconductor components, and the thermal conductivity κ is very high 437 W. m ^-1 . K ^-1 , the joint strength of the metal diamond composite layer and the core layer is extremely large 0.56 GPa. The results are summarized in Table 1.

(Example 1-10)

The particle diameter of the diamond particles in the first and second metal diamond composite layers was 20 μm, and a heat dissipation substrate similar to that of Example 1-5 was produced. The obtained heat-dissipating substrate has a thickness of 1500 μm and a thermal expansion coefficient α of 8.5×10 ^-6 K ^-1 , which is suitable for mounting or holding semiconductor components, and the thermal conductivity κ is very high 405 W. m ^-1 . K ^-1 , the joint strength of the metal diamond composite layer and the core layer is extremely large 0.56 GPa. The results are summarized in Table 1.

(Example 1-11)

The particle diameter of the diamond particles in the first and second metal diamond composite layers was 15 μm, and a heat dissipation substrate similar to that of Example 1-5 was produced. The obtained heat-dissipating substrate has a thickness of 1500 μm and a thermal expansion coefficient α of 8.5×10 ^-6 K ^-1 , which is suitable for carrying or holding a semiconductor element, and has a thermal conductivity κ of 397 W. m ^-1 . K ^-1 , the joint strength of the metal diamond composite layer and the core layer is extremely large 0.56 GPa. In Example 1-11, the particle diameter of the diamond particles is smaller than the desired range, so the heat conductivity κ of the heat-dissipating substrate is lower than the desired range. The results are summarized in Table 1.

(Example 1-12)

The thickness of the core material layer was 100 μm, the thickness of the first and second metal diamond composite layers was 100 μm, and the particle diameter of the diamond particles in the first and second metal diamond composite layers was 50 μm. -5 identical heat sink substrate. The obtained heat-dissipating substrate has a thickness of 300 μm and a thermal expansion coefficient α of 8.5×10 ^-6 K ^-1 , which is suitable for mounting or holding semiconductor components, and the thermal conductivity κ is extremely high at 402 W. m ^-1 . K ^-1 , the joint strength of the metal diamond composite layer and the core layer is extremely large 0.56 GPa. The results are summarized in Table 1.

(Example 1-13)

The thickness of the core material layer was 250 μm, and the thickness of the first and second metal diamond composite layers was 250 μm. Further, the same heat dissipation substrate as in Example 1-12 was produced. The obtained heat-dissipating substrate has a thickness of 750 μm and a thermal expansion coefficient α of 8.5×10 ^-6 K ^-1 , which is suitable for mounting or holding semiconductor components, and the thermal conductivity κ is extremely high at 405 W. m ^-1 . K ^-1 , the joint strength of the metal diamond composite layer and the core layer is extremely large 0.56 GPa. The results are summarized in Table 1.

(Example 1-14)

The thickness of the core material layer was 1000 μm, and the thickness of the first and second metal diamond composite layers was 1000 μm. Further, the same heat dissipation substrate as in Example 1-12 was produced. The obtained heat-dissipating substrate has a thickness of 3000 μm and a thermal expansion coefficient α of 8.5×10 ^-6 K ^-1 , which is suitable for mounting or holding semiconductor components, and the thermal conductivity κ is extremely high 410 W. m ^-1 . K ^-1 , the joint strength of the metal diamond composite layer and the core layer is extremely large 0.57 GPa. The results are summarized in Table 1.

(Example 1-15)

The thickness of the first and second metal diamond composite layers was 2000 μm, and the same heat dissipation substrate as in Example 1-14 was produced. The obtained heat-dissipating substrate has a thickness of 5000 μm and a thermal expansion coefficient α of 8.5×10 ^-6 K ^-1 , which is suitable for mounting or holding semiconductor components, and the thermal conductivity κ is extremely high 471 W. m ^-1 . K ^-1 , the joint strength of the metal diamond composite layer and the core layer is extremely large 0.56 GPa. The results are summarized in Table 1.

(Example 1-16)

A core material having a core layer diameter of 2 inches (5.08 cm) and a thickness of 600 μm (tungsten purity of 99.9% by mass) (coefficient of thermal expansion α: 4.5×10 ^-6 K ^-1 , thermal conductivity κ: 180 W.m) ^-1 .K ^-1 ), and the same heat dissipation substrate as in Example 1-9 was produced. The obtained heat-dissipating substrate has a thickness of 1800 μm and a thermal expansion coefficient α of 8.3×10 ^-6 K ^-1 , which is suitable for mounting or holding semiconductor components, and the thermal conductivity κ is extremely high at 444 W. m ^-1 . K ^-1 , the joint strength of the metal diamond composite layer and the core layer is extremely large 0.66 GPa. The results are summarized in Table 1.

(Example 1-17)

A core material having a core material layer diameter of 2 inches (5.08 cm) and a thickness of 600 μm (molybdenum: 60% by mass, copper: 40% by mass, purity of molybdenum and copper of 99.9% by mass, respectively) (thermal expansion coefficient α: 11X10 ^-6 K ^-1 , thermal conductivity κ: 234 W.m ^-1 .K ^-1 ), and the same heat dissipation substrate as in Example 1-9 was produced. The obtained heat-dissipating substrate has a thickness of 1800 μm and a thermal expansion coefficient α of 10.2×10 ^-6 K ^-1 , which is suitable for mounting or holding semiconductor components, and the thermal conductivity κ is extremely high 477 W. m ^-1 . K ^-1 , the joint strength of the metal diamond composite layer and the core layer is extremely large 0.48 GPa. The results are summarized in Table 1.

(Example 1-18)

The core material has a diameter of 2 inches (5.08 cm), a thickness of 600 μm of WNi (tungsten: 99% by mass, nickel: 1% by mass, and a purity of tungsten and nickel of 99.9% by mass, respectively) core material (thermal expansion coefficient α: 5X10 ^-6 K ^-1 , thermal conductivity κ: 130 W.m ^-1 .K ^-1 ), and the same heat dissipation substrate as in Example 1-9 was produced. The obtained heat-dissipating substrate has a thickness of 1800 μm and a thermal expansion coefficient α of 8.1×10 ^-6 K ^-1 , which is suitable for carrying or holding semiconductor components, and the thermal conductivity κ is 395 W. m ^-1 . K ^-1 , the joint strength of the metal diamond composite layer and the core layer is extremely large 0.62 GPa. In Example 1-18, since the thermal conductivity κ of the core layer was too low, the thermal conductivity κ of the heat dissipation substrate became low. The results are summarized in Table 1.

(Example 1-19)

A core material having a core layer diameter of 2 inches (5.08 cm) and a thickness of 600 μm (molybdenum: 20% by mass, copper: 80% by mass, and molybdenum and copper having a purity of 99.9% by mass, respectively) (thermal expansion coefficient α: 16X10 ^-6 K ^-1 , thermal conductivity κ: 340 W.m ^-1 .K ^-1 ), and the same heat dissipation substrate as in Example 1-9 was produced. The obtained heat-dissipating substrate has a thickness of 1800 μm and a thermal expansion coefficient α of 13.5×10 ^-6 K ^-1 , which is suitable for mounting or holding semiconductor components, and the thermal conductivity κ is extremely high 517 W. m ^-1 . K ^-1 , the joint strength of the metal diamond composite layer and the core layer is extremely large 0.54 GPa. In Example 1-19, the thermal expansion coefficient α of the core material layer was too large, so that the thermal expansion coefficient α of the heat dissipation substrate became large. The results are summarized in Table 1.

[Example 2]

(Example 2-1)

1. Prepare the core layer

Referring to Fig. 1, the core material layer 10 is prepared with a core material having a diameter of 2 inches (5.08 cm) and a thickness of 500 μm (molybdenum purity of 99.9% by mass) (coefficient of thermal expansion α: 5.2×10 ^-6 K ^-1 , thermal conductivity) κ: 142 W.m ^-1 .K ^-1 ).

2. Making the first and second metal diamond composite layers

The copper diamond composition (metal diamond composition) was mixed with diamond particles having an average particle diameter of 100 μm and a purity of 99.9% by mass in the same manner as in Example 1-1 of Example 1, and was coated with a thickness of 0.5 μm to 1.0 μm. a commercially available titanium-coated diamond particle (MBG600 100 μ TI manufactured by DI (Diamond Innovation International) Co., Ltd.), a powder of copper/titanium-coated diamond particles (metal-coated diamond particles) having a thickness of 10 μm and an electroless copper plating layer, and The powder of electrolytic copper (metal) particles having an average particle diameter of 100 μm was such that the diamond content in the entire composition was 30% by volume.

The copper diamond composition was molded at a pressure of 8000 kgf/cm ² , and then sintered at 850 ° C for 2 hours in a vacuum atmosphere, and then hot-rolled at 630 ° C and a pressure reduction rate of 10%. In this way, the first and second metal diamond composite layers each having a thickness of 600 μm can be obtained.

3. Production of heat sink substrate

The first metal diamond composite layer, the core material layer, and the second metal diamond composite layer were placed in this order, and electric current sintering was performed in a vacuum atmosphere at 850 ° C for 1 hour and at a current density of 500 A/cm ² . As a result, a heat dissipation substrate having a thickness of 1,700 μm can be obtained.

4. Evaluation of heat sink substrate

The obtained heat-dissipating substrate was evaluated in the same manner as in Example 1-1, and the coefficient of thermal expansion α was 8.3 X10 ^-6 K ^-1 , which was suitable for mounting or holding of a semiconductor element, and the thermal conductivity κ was very high at 412 W. m ^-1 . K ^-1 , the joint strength of the metal diamond composite layer and the core layer is very large 0.55 GPa. The results are shown in Table 2.

(Example 2-2)

The thickness of the core material layer was 300 μm, and the particle diameter of the diamond particles in the first and second metal diamond composite layers was 250 μm, and the diamond content was 8% by volume. Further, the same heat dissipation substrate as in Example 2-1 was produced. The obtained heat-dissipating substrate has a thickness of 1500 μm and a thermal expansion coefficient α of 14.0 X10 ^-6 K ^-1 , which is suitable for mounting or holding semiconductor components, and the thermal conductivity κ is very high 387 W. m ^-1 . K ^-1 , the joint strength of the metal diamond composite layer and the core layer is extremely large 0.67 GPa. In Example 2-2, the diamond content rate is lower than the desired range. Therefore, the thermal expansion coefficient α of the heat dissipation substrate is higher than the desired range, and the thermal conductivity κ of the heat dissipation substrate is lower than the desired range. The results are summarized in Table 2.

(Example 2-3)

The amount of diamond in the first and second metal diamond composite layers was 10% by volume, and the same heat dissipation substrate as in Example 2-2 was produced. The obtained heat-dissipating substrate has a thickness of 1500 μm and a thermal expansion coefficient α of 12.9×10 ^-6 K ^-1 , which is suitable for mounting or holding semiconductor components, and the thermal conductivity κ is very high at 408 W. m ^-1 . K ^-1 , the joint strength of the metal diamond composite layer and the core layer is extremely large 0.61 GPa. The results are summarized in Table 2.

(Example 2-4)

The amount of diamond in the first and second metal diamond composite layers was 20% by volume, and the same heat dissipation substrate as in Example 2-2 was produced. The obtained heat-dissipating substrate has a thickness of 1500 μm and a thermal expansion coefficient α of 11.0×10 ^-6 K ^-1 , which is suitable for mounting or holding semiconductor components, and the thermal conductivity κ is very high 451 W. m ^-1 . K ^-1 , the joint strength of the metal diamond composite layer and the core layer is extremely large 0.56 GPa. The results are summarized in Table 2.

(Example 2-5)

The content of the diamond in the first and second metal-diamond composite layers was 30% by volume, and the same heat dissipation substrate as in Example 2-2 was produced. The obtained heat-dissipating substrate has a thickness of 1500 μm and a thermal expansion coefficient α of 8.3×10 ^-6 K ^-1 , which is suitable for mounting or holding semiconductor components, and has a thermal conductivity κ of 480 W. m ^-1 . K ^-1 , the joint strength of the metal diamond composite layer and the core layer is extremely large 0.56 GPa. The results are summarized in Table 2.

(Example 2-6)

The amount of diamond in the first and second metal diamond composite layers was 40% by volume, and the same heat dissipation substrate as in Example 2-2 was produced. The obtained heat-dissipating substrate has a thickness of 1500 μm and a thermal expansion coefficient α of 8.2×10 ^-6 K ^-1 , which is suitable for mounting or holding semiconductor components, and the thermal conductivity κ is very high 520 W. m ^-1 . K ^-1 , the joint strength of the metal diamond composite layer and the core layer is extremely large 0.59 GPa. The results are summarized in Table 2.

(Example 2-7)

The content of the diamond in the first and second metal-diamond composite layers was 50% by volume, and the same heat dissipation substrate as in Example 2-2 was produced. The obtained heat-dissipating substrate has a thickness of 1500 μm and a thermal expansion coefficient α of 7.4×10 ^-6 K ^-1 , which is suitable for carrying or holding a semiconductor element, and has a thermal conductivity κ of 377 W. m ^-1 . K ^-1 , the joint strength of the metal diamond composite layer and the core layer is 0.55 GPa. In Example 2-7, since the diamond content rate is too high, the heat conductivity κ of the heat dissipation substrate becomes small. The results are summarized in Table 2.

(Example 2-8)

The particle diameter of the diamond particles in the first and second metal diamond composite layers was 300 μm, and a heat dissipation substrate similar to that of Example 2-7 was produced. The obtained heat-dissipating substrate has a thickness of 1500 μm and a thermal expansion coefficient α of 6.8×10 ^-6 K ^-1 , which is suitable for carrying or holding a semiconductor element, and has a thermal conductivity κ of 321 W. m ^-1 . K ^-1 , the joint strength of the metal diamond composite layer and the core layer is 0.55 GPa. In Example 2-8, the diamond content ratio is too high, and the particle size of the diamond particles is larger than the desired range. Therefore, the thermal expansion coefficient α of the heat dissipation substrate is lower than the desired range, and the heat dissipation substrate is The thermal conductivity κ is lower than the expected range. The results are summarized in Table 2.

(Example 2-9)

The particle diameter of the diamond particles in the first and second metal diamond composite layers was set to 100 μm, and a heat dissipation substrate similar to that of Example 2-5 was produced. The obtained heat-dissipating substrate has a thickness of 1500 μm and a thermal expansion coefficient α of 8.4×10 ^-6 K ^-1 , which is suitable for mounting or holding semiconductor components, and the thermal conductivity κ is very high at 440 W. m ^-1 . K ^-1 , the joint strength of the metal diamond composite layer and the core layer is extremely large 0.58 GPa. The results are summarized in Table 2.

(Example 2-10)

The particle diameter of the diamond particles in the first and second metal-diamond composite layers was 20 μm, and the same heat dissipation substrate as in Example 2-5 was produced. The obtained heat-dissipating substrate has a thickness of 1500 μm and a thermal expansion coefficient α of 8.2×10 ^-6 K ^-1 , which is suitable for mounting or holding semiconductor components, and the thermal conductivity κ is very high 415 W. m ^-1 . K ^-1 , the joint strength of the metal diamond composite layer and the core layer is extremely large 0.54 GPa. The results are summarized in Table 2.

(Example 2-11)

The particle diameter of the diamond particles in the first and second metal diamond composite layers was 15 μm, and the same heat dissipation substrate as in Example 2-5 was produced. The obtained heat-dissipating substrate has a thickness of 1500 μm and a thermal expansion coefficient α of 8.3×10 ^-6 K ^-1 , which is suitable for carrying or holding semiconductor components, and the thermal conductivity κ is 397 W. m ^-1 . K ^-1 , the joint strength of the metal diamond composite layer and the core layer is 0.55 GPa. In Example 2-11, the particle diameter of the diamond particles is smaller than the desired range, so the thermal conductivity κ of the heat-dissipating substrate is lower than the desired range. The results are summarized in Table 2.

(Example 2-12)

The thickness of the core material layer was 100 μm, the thickness of the first and second metal diamond composite layers was 100 μm, and the particle diameter of the diamond particles in the first and second metal diamond composite layers was 50 μm. -5 identical heat sink substrate. The obtained heat-dissipating substrate has a thickness of 300 μm and a thermal expansion coefficient α of 8.5×10 ^-6 K ^-1 , which is suitable for carrying or holding a semiconductor element, and the thermal conductivity κ is extremely high 409 W. m ^-1 . K ^-1 , the joint strength of the metal diamond composite layer and the core layer is 0.55 GPa. The results are summarized in Table 2.

(Example 2-13)

The thickness of the core material layer was 250 μm, and the thickness of the first and second metal diamond composite layers was 250 μm. Further, the same heat dissipation substrate as in Example 2-12 was produced. The obtained heat-dissipating substrate has a thickness of 750 μm and a thermal expansion coefficient α of 8.4×10 ^-6 K ^-1 , which is suitable for mounting or holding semiconductor components, and the thermal conductivity κ is extremely high at 404 W. m ^-1 . K ^-1 , the joint strength of the metal diamond composite layer and the core layer is extremely large 0.56 GPa. The results are summarized in Table 2.

(Example 2-14)

The thickness of the core material layer was 1000 μm, and the thickness of the first and second metal diamond composite layers was 1000 μm. Further, the same heat dissipation substrate as in Example 2-12 was produced. The obtained heat-dissipating substrate has a thickness of 3000 μm and a thermal expansion coefficient α of 8.6×10 ^-6 K ^-1 , which is suitable for mounting or holding semiconductor components, and the thermal conductivity κ is extremely high 411 W. m ^-1 . K ^-1 , the joint strength of the metal diamond composite layer and the core layer is extremely large 0.57 GPa. The results are summarized in Table 2.

(Example 2-15)

The thickness of the first and second metal diamond composite layers was 2000 μm, and the same heat dissipation substrate as in Example 2-14 was produced. The obtained heat-dissipating substrate has a thickness of 5000 μm and a thermal expansion coefficient α of 8.3×10 ^-6 K ^-1 , which is suitable for mounting or holding semiconductor components, and the thermal conductivity κ is extremely high 481 W. m ^-1 . K ^-1 , the joint strength of the metal diamond composite layer and the core layer is extremely large 0.57 GPa. The results are summarized in Table 2.

(Example 2-16)

A core material having a core layer diameter of 2 inches (5.08 cm) and a thickness of 600 μm (tungsten purity of 99.9% by mass) (coefficient of thermal expansion α: 4.5×10 ^-6 K ^-1 , thermal conductivity κ: 180 W.m) ^-1 .K ^-1 ), and the same heat dissipation substrate as in Example 2-9 was produced. The obtained heat-dissipating substrate has a thickness of 1800 μm and a thermal expansion coefficient α of 8.9×10 ^-6 K ^-1 , which is suitable for mounting or holding semiconductor components, and the thermal conductivity κ is extremely high at 454 W. m ^-1 . K ^-1 , the joint strength of the metal diamond composite layer and the core layer is extremely large 0.65 GPa. The results are summarized in Table 2.

(Example 2-17)

A core material having a core material layer diameter of 2 inches (5.08 cm) and a thickness of 600 μm (molybdenum: 60% by mass, copper: 40% by mass, purity of molybdenum and copper of 99.9% by mass, respectively) (thermal expansion coefficient α: 11X10 ^-6 K ^-1 , thermal conductivity κ: 234 W.m ^-1 .K ^-1 ), and the same heat dissipation substrate as in Example 2-9 was produced. The obtained heat-dissipating substrate has a thickness of 1800 μm and a thermal expansion coefficient α of 10.0×10 ^-6 K ^-1 , which is suitable for mounting or holding semiconductor components, and the thermal conductivity κ is extremely high at 480 W. m ^-1 . K ^-1 , the joint strength of the metal diamond composite layer and the core layer is extremely large 0.49 GPa. The results are summarized in Table 2.

(Example 2-18)

The core material has a diameter of 2 inches (5.08 cm), a thickness of 600 μm of WNi (tungsten: 99% by mass, nickel: 1% by mass, and a purity of tungsten and nickel of 99.9% by mass, respectively) core material (thermal expansion coefficient α: 5X10 ^-6 K ^-1 , thermal conductivity κ: 130 W.m ^-1 .K ^-1 ), and the same heat dissipation substrate as in Example 2-9 was produced. The obtained heat-dissipating substrate has a thickness of 1800 μm and a thermal expansion coefficient α of 8.3×10 ^-6 K ^-1 , which is suitable for mounting or holding semiconductor components, and has a thermal conductivity κ of 391 W. m ^-1 . K ^-1 , the joint strength of the metal diamond composite layer and the core layer is extremely large 0.61 GPa. In Example 2-18, since the thermal conductivity κ of the core layer was too low, the thermal conductivity κ of the heat dissipation substrate became low. The results are summarized in Table 2.

(Example 2-19)

A core material having a core layer diameter of 2 inches (5.08 cm) and a thickness of 600 μm (molybdenum: 20% by mass, copper: 80% by mass, and molybdenum and copper having a purity of 99.9% by mass, respectively) (thermal expansion coefficient α: 16X10 ^-6 K ^-1 , thermal conductivity κ: 340 W.m ¹ .K ^-1 ), and the same heat dissipation substrate as in Example 2-9 was produced. The obtained heat-dissipating substrate has a thickness of 1800 μm and a thermal expansion coefficient α of 13.2×10 ^-6 K ^-1 , which is suitable for mounting or holding semiconductor components, and the thermal conductivity κ is extremely high at 523 W. m ¹ . K ¹ , the joint strength of the metal diamond composite layer and the core layer is extremely large 0.53 GPa. In Example 2-19, the thermal expansion coefficient α of the core material layer was too large, so that the thermal expansion coefficient α of the heat dissipation substrate became large. The results are summarized in Table 2.

The embodiments and examples of the present invention are exemplified in the following, and are not intended to limit the invention. The scope of the present invention is defined by the scope of the claims, and the scope of the patent application, and all modifications within the scope and scope of the patent application are included in the scope of the patent application.

[Industrial Availability]

The heat dissipation substrate of the present invention is very suitable for use in a semiconductor memory IC, an LSI, a power device, a communication device, an optical device, a device for a detector, and a module of the above object.

1‧‧‧heated substrate

10‧‧‧ core layer

11‧‧‧1st metal diamond composite layer

12‧‧‧2nd metal diamond composite layer

Fig. 1 is a view showing an example of a heat dissipation substrate of the present invention.

1‧‧‧heated substrate

10‧‧‧ core layer

11‧‧‧1st metal diamond composite layer

12‧‧‧2nd metal diamond composite layer

Claims (6)

A heat dissipation substrate comprising: a first metal diamond composite layer (11); a second metal diamond composite layer (12); and a core material layer (10) disposed on the first metal diamond composite layer (11) and the second The metal diamond composite layer (12) is characterized in that the first metal diamond composite layer (11) and the second metal diamond composite layer (12) have a diamond content of less than 50% by volume, respectively. The layer (10) has a coefficient of thermal expansion parallel to the main surface of 4.5X10 ^-6 K ^-1 ~13 X10 ^-6 K ^-1 , and the thermal conductivity in the thickness direction is greater than 140W. m ^-1 . K ^-1 . The heat-dissipating substrate according to claim 1, wherein the heat-dissipating substrate (1) has a thermal expansion coefficient of 7×10 ^-6 K ^-1 to 13 X10 ^-6 K ^{-1 in a} direction parallel to the main surface. The thermal conductivity in the thickness direction is greater than 400W. m ^-1 . K ^-1 . The heat dissipation substrate according to claim 1, wherein the heat dissipation substrate (1) has a thickness of 500 μm to 10000 μm. The heat dissipation substrate according to claim 1, wherein the core material layer (10) has a thickness of 50 μm to 4000 μm. The heat dissipation substrate according to claim 1, wherein the core material layer (10) comprises molybdenum. The heat dissipation substrate according to claim 1, wherein the first metal diamond composite layer (11) and the second metal diamond are included The particle size of the diamond particles of the composite layer (12) is 20 μm to 250 μm.