JP4404602B2 - Ceramics-metal composite and high heat conduction heat dissipation substrate using the same - Google Patents

Description

  The present invention relates to a ceramic-metal composite having good thermal conductivity and electrical conductivity, and a highly heat-conductive heat dissipation substrate using the ceramic-metal composite, and particularly to high heat used in a power semiconductor module and as a high-frequency electrode. The present invention relates to a conductive heat dissipation substrate.

  With the recent rapid microfabrication and higher density of semiconductor silicon chips, the size of transistors has decreased, and the degree of integration of ICs (integrated circuits) has increased. Transistors are microfabricated and densified mainly by two technical methods. One of them is an improvement of the transistor itself. In other words, this is a method for controlling the movement of charges propagating through a transistor, such as a MOS (Metal Oxide Semiconductor), a CMOS (Complementary MOS), and a BiCMOS (Bipolar CMOS). The other is a method for controlling the structure of the current inlet / outlet, such as a double gate transistor or a multi-gate transistor. In such a transistor, since the loss of current (leakage) when passing through the gate is converted into thermal energy, the amount of heat generated from the silicon chip is rapidly increased.

  Further, as with the above-described IC, higher output and higher integration of semiconductor elements such as thermoelectric elements, LSIs, VLSIs, diodes, and semiconductor laser elements have progressed, and the amount of heat generated from the semiconductor elements tends to increase rapidly. . For this reason, in a highly integrated semiconductor device such as a hybrid IC, in order to efficiently dissipate heat generated from the semiconductor element, the heat sink made of copper or a refractory metal material is integrated with the ceramic circuit board. It is used after being joined. However, a heat sink made of copper or refractory metal has a large difference in thermal expansion coefficient from that of a semiconductor element or ceramic circuit board. Therefore, repeated thermal shock increases the thermal stress at the joint interface between the two parts, causing peeling. There was a problem that it was easy.

  In order to solve this problem, there is a need for a high thermal conduction heat dissipation substrate for joining a heat dissipation substrate to a semiconductor element to dissipate heat from the semiconductor element to the outside of the system.

  For example, Patent Document 1 discloses that a substrate made of a Cu—W alloy or Cu—Mo alloy having a low Cu content is provided with a through hole, and the Cu—W alloy or Cu having a high Cu content in the through hole. A heat dissipation substrate filled with a Mo alloy so that heat can be conducted in the axial direction of the through hole is illustrated. Further, Patent Document 1 exemplifies a semiconductor module in which a thermoelectric element and a semiconductor laser element are bonded to the heat dissipation substrate and these are further disposed in a housing.

  ICs are packaged by various methods to produce IC packages. For example, IC packages include BGA (Ball Grid Array), DIP (Dual Inline Package), and PGA (Pin Grid Array). For example, a semiconductor chip such as silicon, a circuit conductor for transmitting input / output signals from the semiconductor chip, and leads and pins for transmitting input / output signals from the outside are provided in the IC package. However, the structure is hermetically sealed by a casing made of ceramics, plastic, or the like. The IC package having such a structure has a problem that it breaks or malfunctions due to a temperature rise due to an increase in the amount of heat generated from the silicon chip. In order to suppress the temperature rise of the silicon chip, a high heat conduction heat dissipation substrate is joined to the silicon chip to release heat from the silicon chip out of the system. The problem of peeling due to thermal stress at the interface between the semiconductor element and the high thermal conduction heat dissipation substrate also occurs at the interface between the silicon chip and the high thermal conduction heat dissipation substrate.

  Conventionally, a high heat conduction heat dissipation substrate that is bonded to the silicon chip via solder, or a high heat conduction heat dissipation substrate that is provided with an insulating layer made of a ceramic substrate that is mounted on the silicon chip via solder and to which a circuit conductor is bonded. For example, copper has been widely used because of its high thermal conductivity of 330 W / m · K or higher.

However, copper, the thermal expansion coefficient of silicon is 16.5 × ^{10 -6} /℃,4.2×10 ^-6 / ℃ respectively, consisted of the two there is a large difference, the silicon chip is a high temperature After that, the solder deteriorates during the cooling process, and there is a problem that the heat dissipation substrate easily peels from the silicon chip.

  At present, in order to solve this problem, it has been studied to employ a composite material in which the pores of the silicon carbide porous sintered body are impregnated with copper as a constituent material of the high thermal conduction heat dissipation substrate. This is because the thermal conductivity is high due to copper and the thermal expansion coefficient is close to that of silicon.

  For example, as proposed in Patent Document 2, such a composite material is formed by immersing a silicon carbide porous sintered body in molten copper, pressurizing the copper, and then cooling and solidifying the molten metal. Manufactured by.

Further, in Patent Document 3, as another composite material, the pores of the silicon carbide porous sintered body are impregnated with copper, and a layer that prevents the reaction between the silicon carbide sintered body and copper at the interface between the two (hereinafter referred to as a composite material). For example, a composite material in which a layer made of ZrC, TiC, TaC, Mo ₄ C ₃ , Cr ₄ C ₃ or the like is formed has been proposed.

  In addition, recently, when a composite material such as that described above is used as a constituent material for a substrate for high heat conduction and heat dissipation, when the ambient temperature rises, the ceramic-metal composite restrains the expansion of copper and It is also required to have a stress relaxation function.

Patent Document 4 discloses a heat dissipation component in which an aluminum layer is provided on the surface of a flat silicon carbide-aluminum composite material in which a silicon carbide porous sintered body is impregnated with aluminum.

  Further, Patent Document 5 exemplifies a heat radiating member in which a plurality of rods made of a highly thermally conductive metal are embedded in a hole provided on one of the main surfaces of a substrate made of copper or a copper alloy. The heat radiating member is manufactured by sintering integrally with the rod inserted in a hole provided in a substrate made of unsintered copper or copper alloy.

  Non-Patent Document 1 reports a wetting reaction between a silicon carbide substrate and copper.

Furthermore, in view of the recent demand for miniaturization of IC packages and semiconductor modules, a function for inputting / outputting not only a heat dissipation function but also an electrical signal to a heat dissipation board disposed in the IC package or semiconductor module. It is being considered to have both.
JP 2002-124611 A JP-A-11-29379 JP 2001-122682 A Japanese Patent Laid-Open No. 2003-204022 JP 2003-188324 A Interfacial texture formed by specific wetting reaction between α-SiC / Cu (Journal of the Japan Institute of Metals (1995) Vol. 59)

  However, since the heat dissipating members exemplified in Patent Documents 1 and 5 are made of only metal, the coefficient of thermal expansion is large. For this reason, when the temperature of the semiconductor element changes, a thermal stress is repeatedly applied to the interface between the semiconductor element and the heat dissipation member due to a difference in thermal expansion between the semiconductor element and the heat dissipation member. And there existed a problem that the interface of a semiconductor element and the member for thermal radiation peeled according to this thermal stress.

  Moreover, when the composite material as proposed in Patent Document 2 is manufactured by the method as described above, the silicon carbide porous sintered body reacts with copper, and as a result, the silicon carbide porous sintered body and copper are reacted. A silicon carbide / copper reaction layer was deposited on the interface with the. This silicon carbide / copper reaction layer is prone to cracks, and when used for a high thermal conduction heat dissipation substrate, there is a problem that it is extremely difficult to select an impregnation condition for maintaining a heat dissipation function. Also, if this silicon carbide porous sintered body and copper composite material is used as a high thermal conduction heat dissipation substrate inside a highly reliable component such as an IC package, it will be caused by thermal stress when the temperature of the composite material rises. There was a problem that cracks occurred and the pieces and particles of the silicon carbide porous sintered body were detached, and the pieces and particles contacted the circuits in the IC package, causing the IC package to malfunction.

  Further, the composite material proposed in Patent Document 2 has a problem that heat dissipation is low because the heat dissipation area per unit volume of the composite material is small.

Moreover, since the composite material which comprises the composite material of patent document 2, and the thermal radiation component of patent document 4 is a structure where the metal lump is disperse | distributed disperse | distributed discontinuously in the pore of a silicon carbide porous sintered compact. There was a problem that heat could not be efficiently dissipated.

In addition, the composite material proposed in Patent Document 3 solves the above-mentioned problems, but the control process for forming the reaction prevention layer, ZrC, TiC, TaC, Mo ₄ C ₃ , Cr ₄ required material cost of the C _3, etc., was not easy to manufacture.

Further, when this composite material is used as a constituent material for a substrate for heat dissipation of high thermal conductivity, the silicon carbide porous sintered body constituting the composite material has a thermal expansion coefficient of 4.0 × 10 ⁻⁶ / ° C. However, in consideration of an increase in the ambient temperature during use, it has been desired that the coefficient of thermal expansion be lower.

Furthermore, since the composite materials proposed in Patent Document 2 and Patent Document 3 both use a porous sintered body of silicon carbide, sintering requires a vacuum atmosphere or an inert gas atmosphere, and its production cost is never It was not cheap.

  In Non-Patent Document 1, it is reported that a silicon carbide / copper reaction layer is deposited at the interface between the silicon carbide substrate and copper, and cracks are generated in the reaction layer. It could not be used.

  As a result of efforts made in view of the above problems, the present inventor has found that a ceramic-metal composite capable of solving the above-described problems can be provided, and has led to the present invention. That is, the present invention not only prevents the precipitation of the reaction layer between the ceramic and the metal, but also eliminates the need for the reaction prevention layer, has good thermal conductivity and electrical conductivity in the impregnation direction, and has an atmospheric temperature. An object of the present invention is to provide a ceramic-metal composite that restrains the expansion of copper even when it rises, does not generate cracks, and can be manufactured at low cost. It is another object of the present invention to provide a ceramic-metal composite in which generation of ceramics and metal pieces (particles) is suppressed.

The ceramic-metal composite of the present invention has a plurality of through-holes in a substrate mainly composed of cordierite, and the through-holes are impregnated with at least one of copper, copper alloy, aluminum, and aluminum alloy. And a metal layer mainly composed of the metal is formed on at least one main surface of the substrate, and the metal layer is connected to the metal impregnated in the through hole .

  Further, the present invention is characterized in that the substrate is a honeycomb structure having a through-hole partitioned by a plurality of partition plates.

  Further, the substrate is porous.

  Moreover, the high heat conduction heat dissipation substrate of the present invention is characterized by using any of the ceramic-metal composites described above.

In a ceramic-metal composite mainly composed of cordierite and having a plurality of through holes in the substrate, the through holes are impregnated with at least one of copper, copper alloy, aluminum, and aluminum alloy. since the cordierite and not reactive layer is deposited on the interface with the metal, thermal and electrical conductivity to excellent ceramics - may be a metal complex. In addition, cordierite as the main component enables firing in the air atmosphere and does not react with any metal of copper, copper alloy, aluminum, and aluminum alloy, so the reaction between ceramics and metal The prevention layer can be dispensed with. As a result, the manufacturing cost can be reduced. Furthermore, a ceramic layer that contributes to heat conduction is formed by forming a metal layer mainly composed of the metal on at least one main surface of the substrate and connecting the metal layer to the metal impregnated in the through hole. -Since the area of the metal composite can be increased, the thermal conductivity is particularly good, and the generation of ceramic and metal pieces (particles) can be suppressed.

  Further, by making the base body into a honeycomb structure having through-holes partitioned by a plurality of partition plates, a ceramic-metal composite having particularly excellent thermal conductivity and electrical conductivity in the through-hole direction can be obtained. it can.

Furthermore, it said substrate by a porous, since the metallic can also be impregnated into the pores, even if the substrate is thin, it is effectively suppressed Wins Rukoto the occurrence of cracks during processing.

  Further, by using the ceramic-metal composite as a high heat conduction heat dissipation substrate, a function required as a high heat conduction heat dissipation substrate, that is, a heat dissipation function, a semiconductor element and other components (for example, a ceramic circuit board) can be electrically connected. It can be set as the board | substrate for high heat conduction heat radiation which satisfy | fills all the electrical wiring functions to connect and the stress relaxation function with respect to a semiconductor element. The ceramic-metal composite can satisfy the electrical wiring function because, when the ceramic-metal composite is a dense body, the through-holes of the base body are substantially perpendicular to the main surfaces of the semiconductor element and the ceramic circuit board. An element, a ceramic-metal composite, and a ceramic circuit board are sequentially laminated through the metal impregnated in the through hole and electrically joined to electrically connect the semiconductor element to the ceramic circuit board through the metal. This is because a signal can be transmitted.

  Hereinafter, the ceramic-metal composite of the present invention will be described with reference to the drawings.

FIGS. 1 (a) has a plurality of through-holes is a perspective view showing a substrate impregnated with metal into the through-hole, in the line X-X 'in FIG. 1 (b) FIGS. 1 (a) It is sectional drawing. 2 (a) is a perspective view showing a substrate before the impregnation of the metal into a plurality of through holes, FIG. 2 (b) Ru sectional view der in line X-X 'in FIG. 2 (a).

The substrate 11 constituting the ceramic-metal composite of the present invention is mainly composed of cordierite , and includes a plurality of through holes 12, and the through holes 12 are at least one of copper, copper alloy, aluminum, and aluminum alloy. The metal 13 is impregnated.

By that the main component of the base body 11 and cordierite, copper Ru impregnated into the through hole 12 of the base 11, a copper alloy, aluminum, because it does not any metal 13 react the aluminum alloy, the base body 11 and the metal 13 The reaction layer is not deposited. Further, the substrate 11 consisting mainly of cordierite, the thermal expansion coefficient of about 0.5 ppm / ° C. at 40 to 400 ° C., the thermal conductivity is about 1W / m · K, as in the prior art, carbonization silicon Compared with a base mainly composed of copper, copper and copper alloy have a thermal conductivity of 340 to 389 W / m · K and an electric conductivity of 0.41 × 10 ^{6 to} 0.58 × 10 ⁶ S / cm (volume) Specific resistance: 1.72 × 10 ^{−6 to} 2.46 × 10 ⁻⁶ Ω · cm), aluminum, and aluminum alloy originally have a thermal conductivity of 188 to 237 W / m · K and an electric conductivity of 0.17 × 10 ^{6 to} 0.35 × 10 ⁶ S / cm (volume resistivity: 2.82 × 10 ^{−6 to} 5.75 × 10 ⁻⁶ Ω · cm 2 ) is hardly lowered, so that heat conductivity and electricity in the impregnation direction are reduced. Conductivity is maintained well and cracks are generated Can be prevented.

  Furthermore, it is possible to perform firing in an air atmosphere, and it is not necessary to provide a reaction preventing layer between the base 11 and the metal 13, and therefore the manufacturing cost can be reduced.

The base body 11 is not preferable to be porous. When the substrate 11 is porous, penetrates the inside of the hole 12 is formed fine irregularities, the base 11 and the metal 13 in the uneven metal 13 intrudes occurs is Rua anchor effect to fixed firmly. Therefore, when the thickness of the base 11 following such thin 2mm also the metal 13 and the substrate 11 which is impregnated in the base 11 is firmly fixed by anchors effect, suppress the generation and cracking of cracks during processing can do. Also, if the group body 11 Ru porous der is firmly fixed by the base 11 and the metal 13 and the anchoring effect, it is possible to prevent peeling of the base 11 and the metal 13 during processing, the Thickness of the base 11 Can be thinned. Specifically, when the substrate 11 is porous, it is possible to reduce the thickness to 3 times the mean pore diameter of transmural hole 12.

  The porosity of the substrate 11 is preferably 30% by volume or more, and the average pore diameter is preferably 4 μm or more. In particular, the porosity of the substrate 11 is 35% by volume or more, and the average pore diameter is preferably 5 μm or more.

Incidentally, when the group 11 in dense ceramics - since the improved strength of the entire metal complex may be selected dense body in the case of particularly required mechanical strength. However, when the substrate 11 is dense, specifically, the porosity of the substrate 11 is about 10% by volume or less, although the mechanical strength is high, the anchor effect is reduced because the surface of the through-hole 12 is difficult to form. The base body 11 and the metal 13 cannot be firmly fixed, and the base body 11 and the metal 13 may be peeled off during processing. Therefore, when the substrate 11 is 緻 dense electrolyte, the thickness Kusuru that the thickness of the base 11, rather preferred you to suppress separation between the substrate 11 and the metal 13, the thickness of the base 11 through holes 12 The average pore diameter is preferably 6 times or more .

Then, with reference to FIGS. 3 and 4, it describes the base Nitsu of honeycomb structure having a through-hole that is defined and formed by a plurality of partition plates.

FIG. 3 is a perspective view of a base 21 having a honeycomb structure 24 having a plurality of partition plates 26 and having through holes 22 defined by the partition plates 26 , and the through holes 22 are impregnated with a metal 23. is there. 4A is a perspective view of the base body 21 before the metal 23 is impregnated into the through holes 22 partitioned by the partition plate 26, and FIG. 4B is a cross-sectional view taken along the line XX ′ in FIG. Sectional drawing and FIG.4 (c) have shown sectional drawing in the YY 'line | wire of Fig.4 (a). Also in this case, like the base body 11 as shown in FIG. 1, it is preferable that the base body 21 is porous, and the metal 23 can be impregnated in the pores of the base body 21 in addition to the through holes 22. Even when the thickness of the ceramic-metal composite is as thin as 2 mm or less, for example, the generation of cracks can be effectively suppressed during processing. The reason for this is considered to be that the base 21 and the impregnated metal 23 are firmly fixed by the anchor effect. Further, when the substrate 21 is porous, the porosity and average pore diameter of the substrate 21 are preferably 25% by volume or more and the average pore diameter is 3 μm or more, as in the above-described range. The reason for this is as described above. When it is roughly constant thickness of the partition plate 26, to suppress the uneven distribution of mechanical stress in the partition plate 26 to the metal 23 ambient temperature rises and are loaded when inflated, whereby a plurality of through It is preferable because the generation of cracks in the substrate 21 having the holes 22 and the through holes 22 impregnated with the metal 23 can be further suppressed. Further, with the honeycomb structural body 24 having a through hole 22 which is divided forming the substrate 21 by a plurality of partition plates 26, it is that Do good especially thermal conductivity and electric conductivity of the through-hole 22 direction.

Here, ceramics of the present invention - the embodiment of the metal complex will be described with reference to FIG.

5 (a) is a ceramic of the present invention - is a perspective view of a metal composite 10, FIG. 5 (b) Ru sectional view der in line X-X 'in FIGS. 5 (a). The ceramic-metal composite 10 of the present invention has a plurality of through holes 12 in a base 11 mainly composed of cordierite, and at least one of copper, copper alloy, aluminum, and aluminum alloy is formed in the through holes 12. Yes impregnated with metal 13, and to form the metal layer 14 composed mainly of metal 1 3 on at least one major surface of the base 11, connected to the metal 13 is impregnated metal layer 14 in the through hole 1 2 It is . This ensures that the ceramic suppressed occurrence of the area contributing the metal 13 to the heat conduction is increased to above improvement thermal conductivity and a ceramic or metal pieces (particles) - Rukoto be a metal complex 10 It is Ru can.

Here, the cause of Pas Tiku Le description, be inferred. When thermal stress is applied to the ceramic-metal composite 10 , it is considered that particles may be generated mainly due to the following three causes.

The generation of the first particles is caused by application of thermal stress to the ceramics constituting the ceramic-metal composite 10. The ceramic constituting the ceramic-metal composite 10 is made of polycrystalline cordierite. Polycrystalline cordierite sinters while leaving a considerable mechanical stress in the sintering process. When a thermal stress is applied to the ceramic-metal composite 10 , a composite stress C obtained by applying a thermal stress to the mechanical stress is applied to the ceramic. Due to the composite stress C, the crystal grains of polycrystalline cordierite and a part of the grain boundary phase are separated and become particles.

Generation of the second particles is caused by application of thermal stress to the metal 13. As described in the method for producing the ceramic-metal composite 10 of the present invention, which will be described later, the metal 13 is cooled after being impregnated in the through-holes 12 in a molten state at high temperature. In this cooling process, the metal 13 may become polycrystalline, or may rarely become amorphous when rapidly cooled. The polycrystalline or amorphous metal 13 may generate and remain mechanical stress in the cooling process. When a thermal stress is applied to the ceramic-metal composite 10 , a composite stress M obtained by further applying a thermal stress to the mechanical stress is applied to the metal 13. Due to the composite stress M, a part of the metal 13 is detached and becomes particles.

The generation of the third particles is caused by the difference in thermal expansion coefficient between the polycrystalline cordierite and the metal 13. When a thermal stress is applied to the ceramic-metal composite 10 , a portion where the ceramic and the metal 13 are in contact with each other due to a difference in thermal expansion coefficient between the ceramic and the metal 13, that is, the through-hole 12 of the polycrystalline cordierite A local stress is generated at the interface with the metal 13. The ceramic-metal composite 10 of the present invention can suppress the occurrence of cracks and cracks even when this local stress is applied. However, microscopically, when this local stress is repeatedly applied, a cordierite crystal or a part of the metal 13 separates into fine particles at the interface and becomes particles.

  Of these three causes, it is considered that the second particles are hardly generated. The reason for this is that the metal 13 is very ductile compared to polycrystalline cordierite and is capable of large elastic deformation, so it is considered that a part of the metal 13 is hardly detached. . On the other hand, the generation of the first and third particles is much higher than the generation of the second particles in view of the fact that cordierite is a brittle material compared to metal and is brittle against repeated stress. It is inferred. Therefore, by providing the metal layer 14 on the main surface of the ceramic-metal composite 10, generation of the first and third particles can be suppressed, and as a result, the amount of particles generated from the ceramic-metal composite 10 can be reduced. It is thought that you can.

Although not shown, the metal layer 14 is formed on the bases 11 and 21 having the plurality of through holes 12 and 22 shown in FIGS. 1 and 3 and impregnating the through holes 12 and 22 with the metals 13 and 23. Thus, the ceramic-metal composite 10 of the present invention is obtained, and even when the thickness of the ceramic-metal composite 10 is as thin as 0.8 mm or less, cracking during the processing can be suppressed.

Furthermore, ceramics - metal complex 1 0, the area occupied by the metal 13, 23 impregnated in a cross section perpendicular to the through holes 12 and 22, it is preferably 50% or more relative to the area of the cross section. The reason for this is that by increasing the proportion of the metals 13 and 23 as compared with the bases 11 and 21, it is possible to keep the heat conductivity and electrical conductivity high, and a high heat conduction heat dissipation substrate as will be described later. Can be suitably used. On the other hand, when the area occupied by the metal 13, 23 is less than 50%, it is impossible to significantly improve the heat conductivity and electrical conductivity.

Next, the ceramic of the present invention - is described a method for producing a metal complex 1 0.

  First, a substrate 11 having cordierite as a main component as shown in FIG. 2 and having a plurality of parallel through holes 12 is manufactured.

  Here, when making the base | substrate 11 porous, water 20-35 weight% with respect to 100 weight% of mixed raw materials which consist of kaolin, a talc, an alumina, or a hydylite which is a primary raw material first, and cellulose etc. 5-5 as a binder. After the 10% by weight added and mixed raw materials are sufficiently kneaded with a kneader, the molded body of the substrate 11 can be obtained by molding by extrusion molding.

  As described above, when the substrate 11 is made porous with a porosity of 25% by volume or more and an average pore diameter of 3 μm or more, the particle size of the primary material may be 5 to 20 μm. The cordierite itself has a primary material particle size smaller than 1 μm and is densified to a porosity of 20% by volume or less, and becomes a porous body beyond that, and if the primary material particle size is increased, the pore diameter increases. .

  And the base | substrate 11 is obtained by baking this molded object in an atmospheric condition at 1300-1400 degreeC for 2 to 5 hours.

  In addition, although the example of the extrusion molding was described here as an example, after adding 50 to 100% by weight of water and 1 to 10% by weight of a binder such as PVA with respect to 100% by weight of the primary raw material, spray granulation is performed. By granulating using a method, it is possible to produce a molded body using a dry press molding method, a cold isostatic press molding method, or the like.

The chemical composition of the porous substrate 11 obtained in this way, for example, Mg is 10 to 18 wt% in terms of MgO, Si is 42-62% by weight in terms of SiO _2, with Al is in terms _{of Al} 2 _{O 3} The chemical composition is in the range of 22 to 44% by weight, and is close to the theoretical composition of cordierite MgO: 13.7% by weight, SiO ₂ : 51.4% by weight, Al ₂ O ₃ : 34.9% by weight. More preferably.

On the other hand, when the substrate 11 to the dense, for example, kaolin is first primary raw material, talc, were mixed with stirring alumina or HIGILITE, so that the calcined co cordierite composition at 1450 ° C. or higher temperature Synthesize. Thereafter, calcination was synthesized raw material was triturated with an average particle diameter of 2.mu. m or less fine powder, with respect to this call cordierite fines material 100 wt%, water 50 to 100 wt%, sintering of such rare earth oxides 1 to 10% by weight of the agent and 1 to 10% by weight of PVA (polyvinyl alcohol) or PEG (polyethylene glycol) as a binder are added, mixed, granulated by spray granulation, etc., and then filled into a predetermined mold And the molded object of the base | substrate 11 can be obtained by shaping | molding means, such as press molding and cold isostatic pressing.

  And the base | substrate 11 is obtained by baking this molded object for 2 to 5 hours at 1300-1400 degreeC in air | atmosphere atmosphere similarly to the case of porous.

Thus, in order to make the substrate 11 dense, the primary raw material particle size may be reduced. The chemical composition of the obtained substrate 11 is, for example, 11 to 15% by weight of Mg in terms of MgO and Si in terms of SiO _2. 49 to 54 wt%, Al is in the range of 32 to 38 wt% in terms of Al ₂ O ₃ , MgO: 13.7 wt%, the theoretical composition of cordierite, SiO ₂ : 51.4 wt%, Al ₂ O ₃ : It is more preferable that the chemical composition is close to 34.9% by weight.

Next, the substrate 11 is preheated and fixed in a carbon mold, and at least one of copper, copper alloy melted at about 1200 ° C., aluminum melted at about 800 ° C., or aluminum alloy is inserted into the through-hole 12. After being poured into the substrate, it is impregnated with pressure at 10 to 300 MPa and cooled to obtain a substrate 11 having a plurality of through holes 12 as shown in FIG. it can.

Although it is preferred pressure impregnation atmosphere pressurized heating atmosphere gold genus 13 is a nitrogen atmosphere or an inert gas atmosphere, the heating atmosphere may be an air atmosphere with the atmosphere in the pressure impregnation.

  Moreover, the metal to be impregnated may be at least one selected from copper, copper alloy, tough pitch copper, oxygen-free copper, phosphorous deoxidized copper, free-cutting copper, chromium copper, zirconium copper, and the thermal conductivity and electrical conductivity. From the point of view, it is preferable to select tough pitch copper, oxygen-free copper, or phosphorus deoxidized copper. On the other hand, when lightening is required, aluminum or an aluminum alloy may be used rather than copper or a copper alloy. At least one type may be selected. In particular, A1050, A1070, A1080, A1085, and A1100 are preferably selected because of higher thermal conductivity and electrical conductivity.

Further, as shown in FIG. 3, Ri honeycomb structure 24 Tona having a through hole 22 which is defined and formed by the partition plate 26 of the multiple, base 21 impregnated with metal 23 into the through-hole 22, FIG as the substrate 21 4 can be manufactured in the same manner as the above-described manufacturing method except that the honeycomb structure 24 is used.

A metal layer 14 mainly composed of the same metal as the metals 13 and 23 is formed on at least one main surface of the bases 11 and 21 in which the through holes 12 and 22 in FIGS. ceramic of the present invention that the metal layer 14 is connected to the metal 13 and 23 impregnated in the through hole 12, 2 2 - metal complex 1 0 can be prepared, for example, as follows.

First, the metal layer 14 can be formed on at least one main surface of the bases 11 and 21 in which the through holes 12 and 22 are impregnated with the metals 13 and 23 by an electroless plating method of copper or aluminum. Second, the same metal as the main component of the metals 13 and 23 is sprayed on at least one main surface of the bases 11 and 21 in which the through holes 12 and 22 of FIGS. A layer 14 can be provided. Third, the solution metal salt containing the same metal as the metal 13, 23 (the nitrates and oxalates, etc.) is dissolved in water the metal 13 and 23 are present as ions, in FIGS. 1, 3 applied to at least one major surface of the substrate 11 and 21 impregnated with metal 13, 23 into the through hole 12 and 22, drying, heat treatment, by reduction, it may be provided a metal layer 14. Fourth, a heat-resistant container having a flat bottom surface is prepared, one main surface of the substrates 11 and 21 and the bottom surface of the heat-resistant container are leveled, and between the substrates 11 and 21 and the bottom surface of the heat-resistant container. The through holes 1 2 and 2 2 are pressure-impregnated and cooled at 70 MPa with the metals 13 and 23 melted at 1200 ° C. in a nitrogen atmosphere while leaving the bases 11 and 21 in a heat-resistant container with a gap. Thus, the ceramic-metal composite 10 is produced. Further, when the metals 13 and 23 are impregnated with pressure, the other main surface side of the bases 11 and 21 is cooled while being filled with the molten metals 13 and 23 so that both main surfaces of the bases 11 and 21 are filled with metal. The ceramic-metal composite 10 in which the layer 14 is formed can also be produced.

Although FIG 1, like the form of the transmembrane hole 12 is shown for the case of circular shape of the through-holes 12, any shape without departing from oval, triangle, square, etc., the scope of the present invention It does not matter.

Further , the ceramic-metal composite 10 shown in FIG. 5 (having a plurality of through holes 12, 22 and impregnating the through holes 12, 22 with the metals 13, 23, the base body 11 shown in FIGS. , 21 having a metal layer 14 formed thereon ) can be suitably used as a high heat conduction heat dissipation substrate, and electrically connects a heat dissipation function, a semiconductor element, and other components (eg, a ceramic circuit substrate). Therefore, it is possible to provide a highly heat-conducting heat dissipation substrate of the present invention that satisfies all of the electrical wiring function and the stress relaxation function for semiconductor elements. Ceramics - the metal complexes 1 0 is capable of meeting the electrical wiring function, and generally perpendicular to the through holes 12, 22 of the substrate 11, 21 on each main surface of the semiconductor element and the ceramic circuit board, a semiconductor element, ceramics - the metal complex 1 0 Contact and ceramic circuit board are sequentially laminated through the metal 13, 23 and the metal layer 14 impregnated into the through hole 12 and 22, by electrically joining metal 13, 23 and This is because an electrical signal can be transmitted from the semiconductor element to the ceramic circuit board via the metal layer 14 .

The reason for having a heat dissipation function and an electrical wiring function is that both thermal conductivity and electrical conductivity are good. In addition, it has a stress relaxation function by using cordierite having a thermal expansion coefficient as small as about 1.1 × 10 ⁻⁶ / ° C. among ceramics, so that the metal impregnated even when the ambient temperature rises. This is because the expansion can be restrained.

  The ceramic-metal composite of the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the gist of the present invention.

In the following, a description will be given of a preferred embodiment.

As a preferred embodiment, has a plurality of through holes 12 and 22 in FIG. 1 and FIG. 3 as a main component cordierite substrate 11 impregnated with metal 13, 23 into the through-holes 12 and 22 , 21 was prepared. The base | substrates 11 and 21 were adjusted so that the porosity might be 30-50 volume% and an average pore diameter might be 4-8 micrometers.

Further, the carbonization silicon as a main component, 1 to the base of the comparative example in which the metal carbide as a reaction preventing layer, were prepared as a same shape as FIG.

1 has a plurality of through holes 12, and the base 11 in which the through holes 12 are impregnated with a metal 13 includes 600 through holes 12 having a diameter of 1.04 mm, and the through holes 12 are arranged radially. Made as described .

3 has a plurality of through holes 22, and the base 21 in which the through holes 22 are impregnated with a metal 23 includes 600 through holes 22 in a lattice shape and has a square cross-sectional shape. , to produce a length of one side of the square 1.04 mm, the width of the or specifications Setsuban 26 so that the honeycomb structure to 0.19 mm.

  Each through-hole was pressure-impregnated at 70 MPa with copper melted at 1200 ° C. or aluminum melted at 800 ° C. in a nitrogen atmosphere.

Other specifications of that is produced as shown in Table 1, the thermal expansion coefficient of each of the substrates, the thermal conductivity was measured volume resistivity.

Thermal expansion coefficient, thermal conductivity, for volume resistivity, respectively JIS R 1618-1994, JIS R 1611-1991, compliant with JIS C 2141-1992, set forth by each group member or al J IS standard dimensions A sample was cut out and measured.

Moreover, about the presence or absence of a reaction layer and a crack, the cross section was observed for each base | substrate using the scanning electron microscope (SEM), making 1000 times the magnification.

As for the crack, Thickness is prepared 10 pieces each respective substrate 10 mm, grinding each until a thickness of 1mm by using a planar grinding machine, examine whether how many cracks in the 1 0, the number Is shown in Table 1.

Table 1 As is apparent from the results, the samples of the comparative example was impregnated with copper No. Thermal expansion coefficient of 1 and 2, while both are 10.3 × ^{10 -6} / ℃, specimen No. The thermal expansion coefficients of 3 to 12 are good, showing a small value of 10.2 × 10 ⁻⁶ / ° C. or less.

Further, the sample of Comparative Example impregnated with A aluminum No. Whereas the thermal expansion coefficient of 13 and 14 are both 12.6 × ^{10 -6} / ℃, specimen No. The thermal expansion coefficients of 15 to 24 are good, showing a small value of 12.4 × 10 ⁻⁶ / ° C. or less.

  When impregnated with aluminum, the overall coefficient of thermal expansion tends to be higher than when impregnated with copper. However, when weight reduction is required, a ceramic structure or honeycomb structure impregnated with aluminum is required. It is more effective to use it.

Sample No. impregnated with aluminum To the thermal conductivity of 15 to 24 that is 190~203W / m · K, the copper was impregnated Sample No. The thermal conductivity of 3 to 12 shows a large value of 250 to 258 W / m · K, which is particularly good.

In addition, Sample No. with a copper occupation area ratio of 40% was used. 3, 4, 11, and 12 are samples whose volume resistivity is 8.8 × 10 ^{−6 to} 9.0 × 10 ⁻⁶ Ω · cm, whereas the occupied area ratio of copper is 50% or more. No. 5 to 10 has a volume resistivity as low as 2.0 × 10 ^{−6 to} 2.3 × 10 ⁻⁶ Ω · cm, and has reached a value desired as a substrate for heat dissipation with high thermal conductivity. is there. In addition, Sample No. with an aluminum occupation area ratio of 40% was used. The volume resistivity of 15, 16, 23 and 24 is 9.0 × 10 ^{−6 to} 9.2 × 10 ⁻⁶ Ω · cm, whereas the occupied area ratio of aluminum is 50% or more. . Nos. 17 to 22 have a low volume resistivity of 2.2 × 10 ^{−6 to} 2.4 × 10 ⁻⁶ Ω · cm, and similarly reach the value desired as a high heat substrate, which is favorable.

  For the reaction layer and cracks, sample no. Although 1, 2, 13, and 14 have formed the reaction prevention layer, it turns out that there is no precipitation of a reaction layer and generation | occurrence | production of a crack, but sample No. of this invention. Nos. 3 to 12 and 15 to 24 are good because there is no precipitation of the reaction layer or generation of cracks even without the reaction preventing layer.

It was examined on the basis of the following for cracks after each of the substrates 10 each Thickness was ground to a 1 mm. Sample No. In Nos. 11, 12, 23, and 24, the metal was impregnated into the through holes and the pores, so that no cracks occurred. Sample No. As for 3-10, 15-22, since the metal was impregnated only to the through-hole, 1 piece crack generate | occur | produced.

A plurality of bases 11 and 21 mainly composed of cordierite prepared as a preferred embodiment of Example 1 are prepared, and one main surface of these bases 11 and 21 (upper surface in FIGS. 1 and 3) or The material No. 1 in which the metal layer 14 was formed on both main surfaces (upper and lower surfaces of FIGS. 25-44 were produced.

As a first method, the metal layer 14 was formed by electroless plating copper or aluminum on at least one main surface of the substrates 11 and 21 . As a second method, the metal layer 14 was formed by spraying copper or aluminum on at least one main surface of the substrates 11 and 21 . As a third method, 1M- copper nitrate aqueous solution or 1M- aluminum nitrate solution, dried and applied to at least one major surface of the substrate 11 and 21, after 1 hour heat treatment at 500 ° C. in air, the reduction in hydrogen Repeat the steps of, forming a metallic layer 14.

Further, as a fourth method, the bottom surface is prepared a flat carbon container, and the horizontal and the bottom surface of one main surface and the heat-resistant container body 11 and 21, and base 11, 21 and the bottom surface of the carbon container With the gaps between them, the bases 11 and 21 are placed in a carbon container, and in a nitrogen atmosphere, copper melted at 1200 ° C. or aluminum melted at 800 ° C. is pressurized to the through holes 11 and 21 at 70 MPa. The impregnation was followed by cooling to form a metal layer 14 on one main surface. In addition, the metal layer 14 was formed on both main surfaces of the bases 11 and 21 by cooling while filling the melted metals 13 and 23 on the other main surface side of the bases 11 and 21 during the pressure impregnation. .

  The thermal conductivity and volume resistivity of the obtained sample were measured in the same manner as in Example 1. When the measurement sample was cut out, the metal layer 14 (upper surface or both surfaces) was included in the measurement sample.

As shown in Table 2, the sample of Example 2 had higher thermal conductivity and lower volume resistivity than the sample of Example 1.

  The amount of particles generated from the samples prepared in Example 1 and Example 2 was measured as follows.

Moreover, the sample was suspended in the pure water put into the beaker using the thin metal wire, and the ultrasonic wave was applied for 1 minute with the ultrasonic cleaner in that state. Thereafter, a sample suspended from a metal wire was taken out from the beaker, and particles in pure water were measured with a particle counter (DHA-1000 manufactured by BRANSON). The amount of particles in Table 3 is a value obtained by converting the measured number of particles into the number per 1 cm ² of the surface area of the ceramic-metal composite. The amount of particles was divided into an amount of particles of 0.5 to 2 μm and an amount of particles of 0.5 μm or less based on the measurement results.

From Table 3, particles of 0.5 to 2 μm were not detected from the samples of Example 1 and Example 2. However, the amount of particles of 0.5 μm or less was smaller in the sample of Example 2 than in the sample of Example 1.

1A is a perspective view showing a base body having a plurality of through holes, and the through holes are impregnated with metal , and FIG. 1B is a cross-sectional view taken along line XX ′ of FIG. It is. 2A is a perspective view showing the base body before the metal is impregnated into the plurality of through holes, and FIG. 2B is a cross-sectional view taken along the line XX ′ in FIG. FIG. 3 is a perspective view showing a substrate having a honeycomb structure having a plurality of partition plates and having through holes partitioned by the partition plates and impregnating the through holes with metal . 4A is a perspective view showing a base body before a metal is impregnated in a through-hole partitioned with a partition plate , FIG. 4B is a cross-sectional view taken along line XX ′ in FIG. FIG. 4C is a cross-sectional view taken along line YY ′ of FIG. FIG. 5A is a perspective view showing an example of the embodiment of the ceramic-metal composite of the present invention, and FIG. 5B is a cross-sectional view taken along the line XX ′ of FIG.

Explanation of symbols

10 : Ceramics-metal composite 11, 21: Substrate 12, 22: Through hole 13, 23: Metal 14: Metal layer 24: Honeycomb structure 26: Partition plate

Claims (4)

The substrate mainly composed of cordierite has a plurality of through holes, and the through holes are impregnated with at least one of copper, copper alloy, aluminum, and aluminum alloy , and at least one of the substrates A ceramic-metal composite is characterized in that a metal layer containing the metal as a main component is formed on the main surface, and the metal layer is connected to the metal impregnated in the through-hole .   2. The ceramic-metal composite according to claim 1, wherein the substrate is a honeycomb structure having a through-hole partitioned by a plurality of partition plates.   The ceramic-metal composite according to claim 1 or 2, wherein the substrate is porous. A high heat conduction heat dissipation substrate using the ceramic-metal composite according to any one of claims 1 to 3 .

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