JP2011073194A - Metal-ceramics joint base and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a metal-ceramics joint base that can be manufactured at low cost, wherein a metallic circuit board has good heat and electrical conductivity and provides high reliability of junction between a clad member and a ceramics board as a metallic circuit board, and a method of manufacturing the same. <P>SOLUTION: When a metallic base 12 is directly joined to one side of a ceramics base 10 and one side of a first metallic plate 14 is directly joined to the other side within a die, a second metallic plate 16 is directly joined to the other side of the first metallic plate 14, whereby a clad member comprising the first metallic plate 14 and the second metallic plate 16 is directly joined to the ceramics base 10. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a metal / ceramic bonding substrate and a manufacturing method thereof, and more particularly to a metal / ceramic bonding substrate in which a clad material made of a plurality of different types of metal plates is bonded to one surface of a ceramic substrate and a manufacturing method thereof.

  Conventionally, power modules are used to control high power in electric vehicles, trains, machine tools, etc., and copper circuit boards are bonded to the surface of ceramic substrates as metal-ceramic insulating substrates for such power modules. Copper-ceramic bonding substrates are used. However, the copper-ceramic bonding substrate has a large difference in the coefficient of thermal expansion between the copper and the ceramic substrate. When mounting electronic parts on the copper-ceramic bonding substrate or using the copper-ceramic bonding substrate, the copper-ceramic bonding substrate The thermal stress due to the thermal expansion difference may cause cracks in the ceramic substrate, or the copper circuit board may be peeled off from the ceramic substrate, and the thermal cycle resistance is not sufficient.

  In recent years, in order to realize higher heat cycle resistance, an aluminum-ceramic bonding substrate using an aluminum circuit board has been proposed and put into practical use. However, the aluminum-ceramic bonding substrate has excellent thermal cycle resistance, but the thermal conductivity and electrical conductivity of aluminum are inferior to copper, and the surface of the aluminum circuit board is wrinkled after thermal cycling. There is a risk of adversely affecting the electronic components mounted on the top. Therefore, there is a demand for a metal / ceramic bonding substrate in which the thermal conductivity and electrical conductivity of the metal circuit board are better than those of the aluminum circuit board and have the same thermal cycle resistance as the aluminum / ceramic bonding substrate.

  As such a metal-ceramic bonding substrate, a metal-ceramic composite substrate in which a copper or molybdenum material is laminated on an aluminum material bonded to a ceramic substrate (see, for example, Patent Document 1), three or more different types of metals are layered. Circuit board (for example, see Patent Document 2) in which the clad foil is bonded to a ceramic substrate, and a wiring board (for example, see Patent Document 3) in which a laminate in which a Cu conductor layer and an Al conductor layer are laminated is bonded to the surface of the ceramic substrate Etc. have been proposed.

Japanese Patent Laid-Open No. 9-234826 (paragraph number 0017) JP-A-11-97807 (paragraph number 0006) JP 2001-185826 (paragraph number 0010)

  However, in the metal-ceramic composite substrate of Patent Document 1, a copper plate or a molybdenum plate is soldered on an aluminum plate bonded to the ceramic substrate, and in the circuit substrate of Patent Document 2, the clad foil is attached to the ceramic substrate via a brazing material. In the wiring substrate of Patent Document 3, since the laminated wiring conductor in which the Cu plate and the Al plate are laminated is joined to the ceramic substrate through the brazing material, the manufacturing cost for joining the clad material to the ceramic substrate is low. In addition, the reliability of bonding between the clad material and the ceramic substrate was not sufficient.

  Therefore, in view of such a conventional problem, the present invention has good thermal conductivity and electrical conductivity of the metal circuit board, and has high reliability of bonding between the clad material as the metal circuit board and the ceramic substrate. Another object of the present invention is to provide a metal / ceramic bonding substrate and a method for manufacturing the same, which can be manufactured at low cost.

  As a result of diligent research to solve the above-described problems, the inventors of the present invention, when directly bonding one surface of the first metal plate of the clad material to the ceramic substrate, on the other surface of the first metal plate. By directly joining the second metal plate of the clad material, the metal circuit plate has good thermal conductivity and electrical conductivity, and the metal with high reliability in joining the clad material as the metal circuit plate and the ceramic substrate -The present inventors have found that a ceramic bonded substrate can be manufactured at low cost and have completed the present invention.

  That is, in the method for manufacturing a metal / ceramic bonding substrate according to the present invention, one surface of the first metal plate is bonded to one surface of the ceramic substrate, and the second metal is bonded to the other surface of the first metal plate. In a method for manufacturing a metal / ceramic bonding substrate to which a plate is attached, a ceramic substrate and a second metal plate are arranged apart from each other in a mold, and one surface of the ceramic substrate in the mold and the second metal plate are After pouring the molten metal so as to come into contact, the first metal plate is formed between the ceramic substrate and the second metal plate by cooling and solidifying the first metal plate on one surface of the ceramic substrate. One surface of the metal plate is directly bonded, and the second metal plate is directly bonded to the other surface of the first metal plate.

  In this metal-ceramic bonding substrate manufacturing method, the molten metal is poured so as to contact one surface of the ceramic substrate and the second metal plate, and then cooled and solidified to thereby form the ceramic substrate and the second metal plate. When the first metal plate is formed between the metal member, the molten metal is poured so as to contact the other surface of the ceramic substrate, and then cooled and solidified, whereby the metal member is placed on the other surface of the ceramic substrate. It is preferable to form and join the metal members directly. The molten metal is preferably a molten aluminum or aluminum alloy. Furthermore, it is preferable that the second metal plate is made of copper, a copper base alloy or an iron-nickel alloy.

  In the metal / ceramic bonding substrate according to the present invention, one surface of the first metal plate is directly bonded to one surface of the ceramic substrate, and the second metal plate is bonded to the other surface of the first metal plate. Are directly bonded.

  In this metal / ceramic bonding substrate, the metal member is preferably bonded directly to the other surface of the ceramic substrate. The first metal plate is preferably made of aluminum or an aluminum alloy. Furthermore, it is preferable that the second metal plate is made of copper, a copper base alloy or an iron-nickel alloy.

  In the metal-ceramic bonding substrate, the second metal plate is bonded to the other surface of the first metal plate when the first metal plate is formed by solidification of the molten metal. preferable. Furthermore, it is preferable that the second metal plate is joined to the other surface of the first metal plate without using solder.

  According to the present invention, a metal-ceramic bonding substrate having a good thermal conductivity and electrical conductivity of a metal circuit board and having a high reliability of bonding between a clad material as a metal circuit board and a ceramic substrate is manufactured at low cost. be able to.

1 is a perspective view of a first embodiment of a metal / ceramic bonding substrate according to the present invention. FIG. 2 is a cross-sectional view of the metal / ceramic bonding substrate shown in FIG. 1. It is sectional drawing of the casting_mold | template used for manufacture of the metal-ceramics bonding board | substrate shown in FIG. It is a perspective view of 2nd Embodiment of the metal-ceramic bonding board | substrate by this invention. FIG. 5 is a cross-sectional view of the metal / ceramic bonding substrate shown in FIG. 4. It is sectional drawing of the casting_mold | template used for manufacture of the metal-ceramics bonding board | substrate shown in FIG.

  Embodiments of a metal / ceramic bonding substrate and a method for manufacturing the same according to the present invention will be described below with reference to the accompanying drawings.

[First Embodiment]
As shown in FIGS. 1 and 2, the first embodiment of the metal / ceramic bonding substrate according to the present invention is a ceramic substrate 10, a metal base plate 12 made of aluminum, and a first made of aluminum as a clad material. Metal plate 14 and a second metal plate 16 made of copper, one surface of the first metal plate 14 is directly bonded to one surface of the ceramic substrate 10, and the second metal plate 16 is the first metal plate 16. The metal base plate 12 is directly bonded to the other surface of the ceramic substrate 10.

  Direct bonding between the ceramic substrate 10 and the metal base plate 12, between the ceramic substrate 10 and the first metal plate 14, and between the first metal plate 14 and the second metal plate 16 is, for example, illustrated in FIG. 3 is performed by pouring molten aluminum into a mold 100 as shown in FIG.

  As shown in FIG. 3, the mold 100 includes a lower mold member 102 having a substantially rectangular planar shape, and an upper mold member 104 having a substantially rectangular planar shape as a lid portion of the lower mold member 102. On the upper surface of the lower mold member 102, one or a plurality of concave portions (ceramic substrate accommodation portion) 102a having substantially the same shape and size as the ceramic substrate 10 (only one is shown in FIG. 3) are formed. . On the bottom surface of the ceramic substrate housing portion 102a, one or a plurality (only one is shown in FIG. 3) having substantially the same shape and size as the clad material made of the first metal plate 14 and the second metal plate 16. ) (A concave portion formed of a first metal plate forming portion 102b for forming the first metal plate 14 and a second metal plate housing portion 102c for housing the second metal plate 16). Is formed. A recess (metal base plate for forming the metal base plate 12) having substantially the same shape and size as the metal base plate 12 is formed on the bottom surface of the upper mold member 104 (the surface facing the lower mold member 102). Forming portion) 104a is formed. The upper mold member 104 is formed with a pouring port (not shown) for pouring molten metal into the mold 100. Further, the lower mold member 102 is formed with a molten metal passage (not shown) extending between the metal base plate forming portion 104a and the first metal plate forming portion 102b, and the ceramic substrate is accommodated in the ceramic substrate housing portion 102a. Even when 10 is accommodated, the metal base plate forming portion 104a and the first metal plate forming portion 102b communicate with each other.

  A copper plate as the second metal plate 16 is accommodated in the second metal plate accommodating portion 102c of the lower mold member 102 of the mold 100, and the ceramic substrate 10 is accommodated in the ceramic substrate accommodating portion 102a. The upper mold member 104 is placed on the side mold member 102, and the molten metal is poured and filled into the metal base plate forming portion 104a of the mold 100. The molten metal is filled up to the first metal plate forming portion 102b (which is a space formed between the first metal plate housing portion 102c and the second metal plate accommodating portion 102c), and then cooled to solidify the molten metal. And a metal-ceramic bonding substrate in which the metal base plate 12, the first metal plate 14 and the second metal plate 16 as the clad material are integrally bonded. Rukoto can.

  In this way, there is no need to previously prepare a clad material made of an aluminum plate (first metal plate 14) and a copper plate (second metal plate 16), and at the same time the ceramic substrate and the aluminum plate are joined, the aluminum plate and the copper plate. Therefore, the manufacturing cost can be drastically reduced.

[Second Embodiment]
As shown in FIGS. 4 and 5, the second embodiment of the metal / ceramic bonding substrate according to the present invention includes a ceramic substrate 110, a back side metal plate 112 made of aluminum, and aluminum made of aluminum as a cladding material. 1 metal plate 114 and a second metal plate 116 made of copper, and one surface of the first metal plate 114 is directly bonded to one surface of the ceramic substrate 110, and the second metal plate 116 is One metal plate 114 is directly bonded to the other surface, and the back side metal plate 112 is directly bonded to the other surface of the ceramic substrate 110.

  Direct bonding between the ceramic substrate 110 and the back surface side metal plate 112, between the ceramic substrate 110 and the first metal plate 114, and between the first metal plate 114 and the second metal plate 116 is, for example, It is performed by pouring molten aluminum into a mold 200 as shown in FIG. 6 and cooling it.

  As shown in FIG. 6, the mold 200 includes a lower mold member 202 having a substantially rectangular planar shape, and an upper mold member 204 having a substantially rectangular planar shape as a lid portion of the lower mold member 202. On the upper surface of the lower mold member 202, one or a plurality of (only one is shown in FIG. 6) recesses (ceramic substrate housing portions) 202 a having substantially the same shape and size as the ceramic substrate 110 are formed. . A concave portion (a back side metal plate forming part for forming the back side metal plate 112) 202b having substantially the same shape and size as the back side metal plate 112 is formed on the bottom surface of the ceramic substrate housing portion 202a. . An opening (through hole) having a substantially rectangular planar shape is formed at a substantially central portion of the upper mold member 204, and the upper mold member lid portion 204a is fitted into the opening so that the bottom surface of the upper mold member 204 (lower One or a plurality (only one in FIG. 6) having the same shape and size as the clad material made of the first metal plate 114 and the second metal plate 116 on the side facing the side mold member 202 Recessed portion (recessed portion formed of a first metal plate forming portion 204b for forming the first metal plate 114 and a second metal plate housing portion 204c for housing the second metal plate 116) Is to be formed. The upper mold member 204 has a pouring port (not shown) for pouring molten metal into the mold 200. The upper mold member 204 and the lower mold member 202 are formed with a melt flow path (not shown) extending between the first metal plate forming portion 204b and the back metal plate forming portion 202b to accommodate the ceramic substrate. Even when the ceramic substrate 110 is accommodated in the portion 202a, the first metal plate forming portion 204b and the back surface side metal plate forming portion 202b communicate with each other.

  A copper plate as the second metal plate 116 is accommodated and fixed in the second metal plate accommodating portion 202 c of the upper mold member 204 of the mold 200, and the ceramic substrate is accommodated in the ceramic substrate accommodating portion 202 a of the lower mold member 202. 110 is accommodated, and the lower mold member 202 is covered with the upper mold member 204, and the first metal plate forming portion 204b of the mold 200 is poured and filled with molten aluminum (not shown). The molten metal is filled up to the first metal plate forming portion 204b (which is a space formed between the ceramic substrate housing portion 202a and the second metal plate housing portion 204c) through the path, and then cooled to melt the molten metal. Solidifying the ceramic substrate 110, the back side metal plate 112, and the first metal plate 114 and the second metal plate 116 as the clad material are integrally contacted. Metal - can be produced ceramic bonding substrate.

  In this way, there is no need to previously prepare a clad material made of an aluminum plate (first metal plate 114) and a copper plate (second metal plate 116), and at the same time the ceramic substrate and the aluminum plate are joined, the aluminum plate and the copper plate. Therefore, the manufacturing cost can be drastically reduced.

  In the metal-ceramic bonding substrates of the first and second embodiments described above, an etching resist having a predetermined circuit shape is masked on the surface of a clad material made of an aluminum plate and a copper plate, and a ferric chloride solution or the like. It is also possible to form a fine circuit by etching. In addition, the reliability of the metal / ceramic bonding substrate can be further increased by gradually reducing the thickness of the end portion of the formed circuit (or stepwise). Furthermore, Ni plating, Ni alloy plating, etc. can also be given to the surface of the clad material which consists of an aluminum plate and a copper plate as needed.

  Moreover, in the metal-ceramic bonding substrate of the first and second embodiments described above, a metal plate made of an aluminum alloy may be used instead of the first metal plates 14 and 114 made of aluminum, and a copper plate Instead of the second metal plates 16 and 116, a metal plate made of a copper base alloy or an iron-nickel alloy may be used.

  Hereinafter, examples of the metal / ceramic bonding substrate and the manufacturing method thereof according to the present invention will be described in detail.

[Example 1]
First, a mold having the same shape as the mold 100 shown in FIG. 3 is used, and a 46 mm × 21 mm × 0.3 mm oxygen-free copper plate is accommodated in the second metal plate accommodating portion 102 c of the lower mold member 102, and ceramics After the ceramic substrate made of 50 mm × 25 mm × 0.6 mm AlN is accommodated in the substrate accommodating portion 102a, the upper mold member 104 is put on the lower mold member 102 and placed in the furnace, and the furnace is filled with an oxygen concentration of 10 ppm or less. The atmosphere was nitrogen. While heating to 750 ° C. in this state, the molten aluminum supplied from the molten metal supply unit removes the oxide film through the narrow flow path of the pouring nozzle attached to the pouring port of the mold 100, The metal base plate forming portion 104a having a size of 70 mm × 45 mm × 5 mm is poured and filled, and the first size having a size of 46 mm × 21 mm × 0.05 mm is passed through the molten metal flow path formed in the lower mold member 102. 1 metal plate accommodating portion 102b was filled. Thereafter, the mold 100 was cooled to solidify the molten aluminum, and further cooled to room temperature. In this way, a metal / ceramic bonding substrate was manufactured in which a ceramic substrate, an aluminum base plate, an aluminum plate having a thickness of 0.05 mm, and a copper plate having a thickness of 0.3 mm were integrally bonded.

  In the obtained metal-ceramic bonding substrate, the depth of the first metal plate forming portion 102b for forming the aluminum plate of the clad material is not sufficient, and the molten aluminum is supplied to the entire first metal plate forming portion 102b. However, although the aluminum plate and the ceramic substrate were only partially joined, it was confirmed that the ceramic substrate, the aluminum plate, and the copper plate were firmly joined at the same time, and the ceramic substrate was not cracked. In addition, it is thought that the alloy with a copper plate is formed in at least one part of the aluminum plate.

[Examples 2 to 4]
Metal-ceramic bonding was performed in the same manner as in Example 1, except that the thickness of the aluminum plate was 0.1 mm (Example 2), 0.15 mm (Example 3), and 0.2 mm (Example 4). When the substrate was manufactured, the ceramic substrate, the aluminum plate, and the copper plate were firmly bonded over the entire bonding surface, and the ceramic substrate was not cracked.

[Example 5]
A metal-ceramic bonding substrate was manufactured by the same method as in Example 1 except that the thickness of the copper plate was 0.5 mm and the thickness of the aluminum plate was 0.5 mm. The ceramic substrate, the aluminum plate, and the copper plate were The entire bonded surface was firmly bonded, and the ceramic substrate was not cracked.

[Example 6]
The metal-ceramic bonding substrate was formed in the same manner as in Example 4 except that the surface of the oxygen-free copper plate was subjected to 6 μm thick Ni—P plating before being housed in the second metal plate housing portion 102c. When manufactured, the ceramic substrate, the aluminum plate, and the copper plate were firmly bonded over the entire bonding surface, and the ceramic substrate was not cracked.

10, 110 Ceramic substrate 12 Metal base plate 14, 114 First metal plate 16, 116 Second metal plate 112 Back side metal plate 100, 200 Mold 102, 202 Lower mold member 102a, 202a Ceramic substrate housing portion 102b, 204b 1st metal plate formation part 102c, 204c 2nd metal plate accommodating part 104, 204 Upper mold member 104a Metal base plate formation part 202b Back surface side metal plate formation part 204a Upper mold member cover part

Claims (10)

In the method of manufacturing a metal-ceramic bonding substrate, wherein one surface of the first metal plate is bonded to one surface of the ceramic substrate, and the second metal plate is attached to the other surface of the first metal plate. The ceramic substrate and the second metal plate are arranged apart from each other in the mold, and after pouring the molten metal so as to contact one surface of the ceramic substrate in the mold and the second metal plate, the ceramic substrate is cooled and solidified. Thus, the first metal plate is formed between the ceramic substrate and the second metal plate, and one surface of the first metal plate is directly bonded to one surface of the ceramic substrate. A method for producing a metal / ceramic bonding substrate, wherein the second metal plate is directly bonded to the other surface of the metal plate. The molten metal is poured so as to be in contact with one surface of the ceramic substrate and the second metal plate, and then cooled and solidified, whereby the first metal plate is interposed between the ceramic substrate and the second metal plate. When forming one metal plate, a metal member is formed on the other surface of the ceramic substrate by pouring the molten metal into contact with the other surface of the ceramic substrate and then cooling and solidifying the molten metal. The metal-ceramic bonding substrate manufacturing method according to claim 1, wherein the metal member is directly bonded. The method for producing a metal / ceramic bonding substrate according to claim 1, wherein the molten metal is a molten metal of aluminum or an aluminum alloy. The method for producing a metal / ceramic bonding substrate according to any one of claims 1 to 3, wherein the second metal plate is made of copper, a copper base alloy, or an iron-nickel alloy. One surface of the first metal plate is directly bonded to one surface of the ceramic substrate, and the second metal plate is directly bonded to the other surface of the first metal plate, Metal-ceramic bonding substrate. 6. The metal / ceramic bonding substrate according to claim 5, wherein a metal member is directly bonded to the other surface of the ceramic substrate. The metal-ceramic bonding substrate according to claim 5 or 6, wherein the first metal plate is made of aluminum or an aluminum alloy. The metal-ceramic bonding substrate according to any one of claims 5 to 7, wherein the second metal plate is made of copper, a copper base alloy, or an iron-nickel alloy. The second metal plate is bonded to the other surface of the first metal plate when the first metal plate is formed by solidification of the molten metal. The metal-ceramic bonding substrate according to any one of 8. The metal-ceramic bonding according to any one of claims 5 to 9, wherein the second metal plate is bonded to the other surface of the first metal plate without using solder. substrate.

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