JP6799392B2 - Metal-ceramic bonded substrate and its manufacturing method - Google Patents

Description

The present invention relates to a metal-ceramic bonded substrate and a method for manufacturing the same, and more particularly to a metal-ceramic bonded substrate in which a metal member is bonded to the ceramic substrate and a method for manufacturing the same.

In conventional power modules used to control large currents in electric vehicles, trains, machine tools, etc., a metal-ceramic insulation substrate is soldered to one side of a metal plate or composite material called the base plate. At the same time, the semiconductor chip is fixed on this metal-ceramics insulating substrate by soldering, and metal heat dissipation fins and cooling jackets are attached to the other surface (back surface) of the base plate by screwing via heat conductive grease. Has been done.

Since the base plate and the semiconductor chip are soldered to the metal-ceramic insulating substrate by heating, the base plate is likely to warp due to the difference in the coefficient of thermal expansion between the joining members during soldering. In addition, the heat generated from the semiconductor chip is released to the air and cooling water by the heat radiation fins and cooling jacket via the metal-ceramics insulating substrate, solder, and base plate, so that the base plate warps during soldering. , The clearance when the heat dissipation fins and the cooling jacket are attached to the base plate becomes large, and the heat dissipation is extremely lowered.

In order to solve such a problem and improve the reliability of the metal-ceramic insulating substrate, a metal-ceramic circuit board using aluminum having a very low yield stress as the base plate, for example, has a proof stress of 320 MPa or less and a thickness. A metal-ceramics circuit board in which a base plate made of aluminum or an aluminum alloy having a thickness of 1 mm or more is directly bonded to a ceramics substrate by a molten metal method has been proposed (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2002-76551 (paragraph No. 0015-0017)

However, although it is necessary to increase the purity of aluminum in order to reduce the yield stress of aluminum, it is difficult to control the crystal grain size of aluminum by the molten metal method, and only a large crystal grain size of 10 mm or more can be obtained. When the crystal particle size is large as described above, the crystal particle size distribution varies, and the warp of the aluminum base plate due to heating such as when soldering a semiconductor chip or the like varies.

Therefore, in view of such conventional problems, the present invention is subjected to heating such as when soldering a semiconductor chip or the like in a metal-ceramic bonded substrate in which a base plate made of aluminum or an aluminum alloy is directly bonded to a ceramic substrate. An object of the present invention is to provide a metal-ceramic bonded substrate and a method for manufacturing the same, which can suppress variations in warpage of the base plate.

As a result of diligent research to solve the above problems, the present inventors placed a ceramic substrate in a mold and poured a molten aluminum or aluminum alloy so as to contact predetermined portions on both sides of the ceramic substrate. After that, the molten metal is cooled and solidified to form a base plate made of aluminum or an aluminum alloy on the peripheral edge and the side surface of one surface of the ceramic substrate and the entire surface of the other surface, and is directly bonded to the ceramic substrate. A metal plate for a circuit pattern made of aluminum or an aluminum alloy is formed on one surface of a ceramics substrate separated from the base plate and directly bonded to the ceramics substrate, so that the base is heated when soldering a semiconductor chip or the like. We have found that it is possible to suppress variations in the warp of a plate, and have completed the present invention.

That is, in the method for manufacturing a metal-ceramic bonded substrate according to the present invention, a ceramic substrate is placed in a mold, and a molten metal of aluminum or an aluminum alloy is poured so as to come into contact with predetermined portions on both sides of the ceramic substrate, and then the molten metal is melted. By cooling and solidifying, a base plate made of aluminum or an aluminum alloy is formed on the peripheral edge and the side surface of one surface and the entire surface of the other surface of the ceramic substrate and directly bonded to the ceramic substrate, and aluminum or aluminum. It is characterized in that a metal plate for a circuit pattern made of an alloy is formed on one surface of a ceramic substrate separated from a base plate and directly bonded to the ceramic substrate.

In this method for manufacturing a metal-ceramic bonded substrate, when the ceramic substrate is arranged in the mold, the ceramic substrate and the reinforcing member are arranged apart from each other in the mold, and when the molten metal is poured, the inside of the mold is formed. When the molten metal is brought into contact with the entire surface of the reinforcing member to form a base plate and directly bonded to the ceramic substrate, the reinforcing member may be directly bonded to the base plate so that the reinforcing member in the mold is surrounded by the base plate. .. In this case, the reinforcing member is preferably made of a metal or ceramic material having a melting point higher than that of the base plate material. Further, the mold is composed of an upper mold member and a lower mold member, an end portion of the reinforcing member is sandwiched between the upper mold member and the lower member, the reinforcing member is supported by the mold, and protrudes from the bottom surface of the lower mold member. The bottom surface and the side surface of the end portion of the ceramic substrate are in contact with the formed plurality of substrate support portions to be supported, and the upper surface of the portion of the plurality of substrate support portions that is in contact with the side surface of the end portion of the ceramic substrate is plurality. It is preferable that the height is higher than the upper surface of the ceramic substrate supported by the substrate support portion of the above.

Further, when the ceramic substrate is arranged in the mold, the ceramic substrate and the electronic component are arranged apart from each other in the mold, and when the molten metal is poured, the molten metal is brought into contact with one surface of the electronic component. When the circuit pattern metal plate is formed and directly bonded to the ceramic substrate, the electronic component may be directly bonded to the circuit pattern metal plate. Further, when the base plate is formed and directly bonded to the ceramic substrate, a plurality of plates arranged substantially parallel to each other and separated from each other at regular intervals on the surface of the base plate opposite to the metal plate for the circuit pattern. The shaped fins may be formed integrally with the base plate. Alternatively, when the base plate is formed and directly bonded to the ceramic substrate, a large number of columnar protrusions protruding apart from each other are integrally formed with the base plate on the surface of the base plate opposite to the circuit pattern metal plate. You may. Further, after the base plate and the circuit pattern metal plate are directly bonded to the ceramic substrate, unnecessary portions of the circuit pattern metal plate can be removed by etching to form a desired circuit pattern.

Further, the metal-ceramics bonded substrate according to the present invention includes a ceramic substrate, a base plate made of aluminum or an aluminum alloy directly bonded to the peripheral edge and the side surface of one surface of the ceramic substrate and the entire surface of the other surface, and the base. It is characterized by including a metal plate for a circuit pattern made of aluminum or an aluminum alloy, which is separated from the plate and directly bonded to one surface of a ceramic substrate.

In this metal-ceramics bonded substrate, a plate-shaped reinforcing member may be arranged inside the base plate at a distance from the ceramics substrate and substantially parallel to the ceramics substrate, and directly bonded to the base plate. In this case, the reinforcing member is preferably made of a metal or ceramic material having a melting point higher than that of the base plate material. Further, the electronic component may be directly bonded to the surface of the metal plate for the circuit pattern opposite to the ceramic substrate. Further, a plurality of plate-shaped fins may be arranged substantially parallel to each other and separated from each other at regular intervals on the surface of the base plate opposite to the ceramic substrate to be integrally formed with the base plate. Further, a large number of columnar protrusions protruding apart from each other may be formed integrally with the base plate on the surface of the base plate opposite to the ceramic substrate. Further, a recess deeper than the thickness of the ceramic substrate may be formed in a portion of the base plate adjacent to the side surface of the ceramic substrate.

According to the present invention, in a metal-ceramic bonded substrate in which a base plate made of aluminum or an aluminum alloy is directly bonded to a ceramic substrate, it is possible to suppress variations in warpage of the base plate due to heating such as when soldering a semiconductor chip or the like. Can be done.

It is a top view which shows the 1st Embodiment of the metal-ceramics bonded substrate by this invention. It is a side view of the metal-ceramics bonded substrate of FIG. 1A. It is an IC-IC line sectional view of the metal-ceramics bonding substrate of FIG. 1A. It is sectional drawing which shows the state which arranged the ceramics substrate in the mold used for manufacturing the metal-ceramics bonded substrate shown in FIGS. 1A to 1C. It is a top view of the lower mold member of the mold of FIG. FIG. 3A is a sectional view taken along line IIIB-IIIB of the lower mold member of FIG. 3A. FIG. 3A is a sectional view taken along line IIIC-IIIC of the lower mold member of FIG. 3A. FIG. 3A is a sectional view taken along line IIID-IIID of the lower mold member of FIG. 3A. FIG. 3A is a sectional view taken along line IIIE-IIIE of the lower mold member of FIG. 3A. It is sectional drawing which shows the state which arranged the ceramics substrate in the modification of the mold used for manufacturing the metal-ceramics bonded substrate shown in FIGS. 1A to 1C. It is a top view which shows the lower mold member of the mold of FIG. It is a VB-VB line sectional view of the lower mold member of FIG. 5A. FIG. 5A is a sectional view taken along line VC-VC of the lower mold member of FIG. 5A. It is a VD-VD line sectional view of the lower mold member of FIG. 5A. It is a VE-VE line sectional view of the lower mold member of FIG. 5A. It is a top view which shows the 2nd Embodiment of the metal-ceramics bonded substrate by this invention. It is a side view of the metal-ceramics bonded substrate of FIG. 6A. It is a VIC-VIC line sectional view of the metal-ceramics bonded substrate of FIG. 6A. 6 is a cross-sectional view showing a state in which the ceramic substrate is arranged in a mold used for manufacturing the metal-ceramic bonded substrate shown in FIGS. 6A to 6C. It is a top view of the lower mold member of the mold of FIG. FIG. 8 is a sectional view taken along line VIIIB-VIIIB of the lower mold member of FIG. 8A. FIG. 8 is a sectional view taken along line VIIIC-VIIIC of the lower mold member of FIG. 8A. FIG. 8 is a sectional view taken along line VIIID-VIIID of the lower mold member of FIG. 8A. FIG. 8 is a sectional view taken along line VIIIE-VIIIE of the lower mold member of FIG. 8A. It is a top view which shows the 3rd Embodiment of the metal-ceramics bonded substrate by this invention. It is a side view of the metal-ceramics bonded substrate of FIG. 9A. 9A is a sectional view taken along line IXC-IXC of the metal-ceramics bonded substrate of FIG. 9A. 9 is a cross-sectional view showing a state in which a ceramic substrate is arranged in a mold used for manufacturing the metal-ceramic bonded substrate shown in FIGS. 9A to 9C. It is a top view of the lower mold member of the mold of FIG. 11A is a cross-sectional view taken along the line XIB-XIB of the lower mold member of FIG. 11A. 11A is a cross-sectional view taken along the line XIC-XIC of the lower mold member of FIG. 11A. 11A is a cross-sectional view taken along the line XID-XID of the lower mold member of FIG. 11A. 11A is a cross-sectional view taken along the line XIE-XIE of the lower mold member of FIG. 11A. It is a top view which shows the 4th Embodiment of the metal-ceramics bonded substrate by this invention. It is a side view of the metal-ceramics bonded substrate of FIG. 12A. 12A is a sectional view taken along line XIIC-XIIC of the metal-ceramics bonded substrate of FIG. 12A. 12 is a cross-sectional view showing a state in which a ceramic substrate is arranged in a mold used for manufacturing the metal-ceramic bonded substrate shown in FIGS. 12A to 12C. It is a perspective view which shows the back side of the 5th Embodiment of the metal-ceramics bonded substrate by this invention. It is a top view which shows the back surface of the metal-ceramics bonding substrate of FIG. 14A. FIG. 14B is a cross-sectional view taken along the line XIVC-XIVC of the metal-ceramics bonded substrate of FIG. 14B. It is a top view which shows the modification of the 5th Embodiment of the metal-ceramics bonded substrate by this invention. It is a side view of the metal-ceramics bonded substrate of FIG. 15A. FIG. 15A is a cross-sectional view taken along the line XVC-XVC of the metal-ceramics bonded substrate of FIG. 15A. 15A is a cross-sectional view showing a state in which a ceramic substrate is arranged in a mold used for manufacturing the metal-ceramic bonded substrate shown in FIGS. 15A to 15C. It is a top view of the lower mold member of the mold of FIG. FIG. 17A is a cross-sectional view taken along the line XVIIB-XVIIB of the lower mold member of FIG. 17A. FIG. 17A is a cross-sectional view taken along the line XVIIC-XVIIC of the lower mold member of FIG. 17A. It is a cross-sectional view of XVIID-XVIID of the lower mold member of FIG. 17A. FIG. 17A is a cross-sectional view taken along the line XVIIE-XVIIE of the lower mold member of FIG. 17A.

Hereinafter, embodiments of the metal-ceramics bonded substrate according to the present invention will be described in detail with reference to the accompanying drawings.

[First Embodiment]
1A to 1C show the first embodiment of the metal-ceramic bonded substrate according to the present invention, and FIGS. 2 and 3A to 3E show molds used for manufacturing the metal-ceramic bonded substrate. Shown.

As shown in FIGS. 1A to 1C, in the first embodiment of the metal-ceramic bonding substrate according to the present invention, a ceramic substrate 10 having a substantially rectangular planar shape and one surface (circuit pattern side) of the ceramic substrate 10 Directly joined to the peripheral edge of one surface of the ceramic substrate 10 and the base plate 12 made of aluminum or an aluminum alloy having a substantially rectangular planar shape directly joined to the peripheral edge and the side surface of the ceramic substrate 10 and the entire surface of the other surface (back surface). It is provided with one or more (two in the illustrated embodiment) metal plate 14 for a circuit pattern made of aluminum or an aluminum alloy directly bonded to one surface of the ceramic substrate 10 away from the bonded base plate 12. ..

In the metal-ceramic bonding substrate of the present embodiment, the ceramic substrate 10 is arranged in the mold 20 as shown in FIG. 2, and the portions corresponding to the base plates 12 on both sides of the Cerax substrate 10 and the metal plate 14 for the circuit pattern are located. It can be manufactured by pouring a molten metal of aluminum or an aluminum alloy and cooling it so that it comes into contact with each other.

As shown in FIG. 2, the mold 20 is made of a breathable material (impermeable to molten metal) such as (porous) carbon or porous metal, and the lower mold member 22 and the upper mold having a substantially rectangular planar shape, respectively. It is composed of a member 24.

As shown in FIGS. 2 and 3A to 3E, a recess (base plate forming portion) 22a for forming a base plate is formed on the upper surface of the lower mold member 22.

At the substantially central portion of the bottom surface of the base plate forming portion 22a, a raised portion 22b having a substantially rectangular planar shape is formed which is raised in a substantially vertical direction from the bottom surface. One or more (two in the illustrated embodiment) recesses (circuit pattern metal plate forming portion) 22c for forming the circuit pattern metal plate are formed in the substantially central portion of the upper surface of the raised portion 22b. ing. The circuit pattern metal plate forming portion 22c is separated from the base plate forming portion 22a via a raised portion 22b, and is between the base plate 12 (the portion on the circuit pattern side) and the circuit pattern metal plate 14. It is designed to ensure insulation.

Further, on the bottom surface of the base plate forming portion 22a, a plurality of (two pairs in the illustrated embodiment) substrate supporting portions (longitudinal substrate supporting portions) having a substantially rectangular planar shape supporting both ends in the longitudinal direction of the ceramic substrate 10 are provided. ) 22d and a plurality of (two pairs in the illustrated embodiment) substrate support portions (widthwise substrate support portions) 22e having substantially rectangular planar shapes supporting both ends in the width direction of the ceramic substrate 10 are substantially rectangular from the bottom surface. It is formed so as to project in the vertical direction. These substrate support portions 22d and 22e are substantially L-shaped in order to abut the peripheral edge portion and the side surface of one surface (the surface on the circuit pattern side) of the ceramic substrate 10 to support the ceramic substrate 10 at a predetermined position. A step is provided so as to have a cross section of the mold. When the ceramic substrate 10 is placed on these substrate support portions 22d and 22e, the ceramic substrate 10 is placed in contact with the upper surface of the raised portion 22b formed in the substantially central portion of the bottom surface of the base plate forming portion 22a. It has become. When the ceramic substrate 10 is placed on the upper surface of the raised portion 22b in this way, the opening of the metal plate forming portion 22c for the circuit pattern is closed by the ceramic substrate 10 and one surface of the ceramic substrate 10 (on the circuit pattern side). The base plate forming portion 22a is secured around the peripheral edge portion and the side surface of the surface) and the entire surface of the other surface (back surface).

The upper mold member 24 is formed with a pouring port (not shown) for pouring molten metal into the base plate forming portion 22a of the lower mold member 22 from a pouring nozzle (not shown). The lower mold member 22 is formed with a molten metal flow path (not shown) extending between the base plate forming portion 22a and the circuit pattern metal plate forming portion 22c, and the ceramic substrate 10 is placed on the upper surface of the raised portion 22b. Even when it is placed, the base plate forming portion 22a and the circuit pattern metal plate forming portion 22c communicate with each other.

In order to manufacture the metal-ceramic bonded substrate of the embodiment shown in FIGS. 1A to 1C using such a mold 20, first, a ceramic substrate is placed on the substrate support portions 22d and 22e of the lower mold member 22. After arranging 10, the upper mold member 24 is put on the lower mold member 22. In this state, when a molten aluminum or aluminum alloy is poured into the mold 20 and cooled, a base plate is formed on the peripheral edge and the side surface of one surface (the surface on the circuit pattern side) of the ceramic substrate 10 and the entire surface of the other surface (the back surface). It is possible to manufacture a metal-ceramic bonding substrate in which the circuit pattern metal plate 14 is directly bonded to the ceramic substrate 10 while the 12 is directly bonded to the base plate 12 (the portion on the circuit pattern side of the base plate 12). A plurality of recesses 12b (see FIG. 1A) corresponding to the substrate support portions 22d and 22e are formed on the base plate 12, but since these recesses 12b are small, the reliability and heat of the metal-ceramic bonded substrate are formed. It has almost no effect on conductivity.

4 and 5A-5E show modified examples of the mold used to manufacture the first embodiment of the method for manufacturing a metal-ceramic bonded substrate according to the present invention.

In the mold 120 of this modification, the width direction of the mold 120 (ceramic substrate 10) is replaced with the plurality of (two in the illustrated embodiment) longitudinal substrate support portions 22d that support one end in the longitudinal direction of the ceramic substrate 10. An elongated substrate support portion 122f having a substantially rectangular planar shape extending in the width direction of the substrate is formed. The elongated substrate support portion 122f has a substantially L-shaped cross section in order to abut the peripheral portion and the side surface of one surface (the surface on the circuit pattern side) of the ceramic substrate 10 to support the ceramic substrate 10 at a predetermined position. A step is provided so as to have. The height of the elongated substrate support portion 122f on the high side is higher than that of the longitudinal substrate support portion 22d and higher than that of the upper surface of the ceramic substrate 10. Since the other configurations are substantially the same as the mold used for manufacturing the metal-ceramic bonded substrate of the above-described embodiment, 100 is added to the reference reference numerals and the description thereof will be omitted. The base plate 12 is formed with a recess (not shown) corresponding to the elongated substrate support portion 122f, but since this recess is small, it has almost no effect on the reliability and thermal conductivity of the metal-ceramic bonded substrate.

[Second Embodiment]
6A to 6C show a second embodiment of the metal-ceramic bonded substrate according to the present invention, and FIGS. 7 and 8A to 8E show molds used for manufacturing the metal-ceramic bonded substrate. Shown.

As shown in FIGS. 6A to 6C, in the second embodiment of the metal-ceramics bonded substrate according to the present invention, the planar shape is one or more substantially rectangular inside the base plate 212 (1 in the illustrated embodiment). The plate-shaped reinforcing member 216 is arranged at a distance from the ceramic substrate 210 and substantially parallel to the ceramic substrate 210. The reinforcing member 216 extends through the inside of the base plate 212 (in the width direction of the ceramic substrate 210), and the end portion of the reinforcing member 216 is exposed to the outside and extends through the inside of the base plate 212. The entire surface (the entire surface other than the end portion) is directly joined to the base plate 212. The reinforcing member 216 is made of a material having a melting point higher than that of the material (aluminum or aluminum alloy) of the base plate 212, and is a metal or alumina containing one or more selected from the group consisting of nickel, cobalt, copper and manganese and iron. , Zirconia, a composite material of alumina and zirconia, and preferably made of a material such as one or more ceramics selected from the group consisting of aluminum nitride, silicon nitride and silicon carbide. By arranging such a reinforcing member 216 inside the base plate 212, the stress generated in the ceramic substrate 210 can be reduced and the warp of the metal-ceramic joint substrate can be reduced, so that the base plate 212 can be reduced. Since the thickness can be increased, the heat capacity of the base plate 212 can be increased to improve heat dissipation. Since the other configurations are substantially the same as those of the metal-ceramics bonded substrate of the first embodiment described above, 200 is added to the reference numerals and the description thereof will be omitted.

In the metal-ceramics bonded substrate of the present embodiment, the ceramics substrate 210 and the reinforcing member 216 are arranged apart from each other in the mold 220 as shown in FIG. 7, and the substantially entire surface of the reinforcing member 216 and the ceramics substrate 210 It can be manufactured by pouring and cooling a molten aluminum or aluminum alloy so as to come into contact with the portions corresponding to the base plate 212 on both sides and the metal plate 214 for the circuit pattern.

As shown in FIGS. 8A to 8E, in the mold 220 used for manufacturing the metal-ceramics bonded substrate of the present embodiment, the upper surface of the lower mold member 222 is (on the circuit pattern side of the base plate 212). On both side surfaces in the width direction of the base plate forming portion 222a (which is a recess for forming a portion), both ends thereof (on the circuit pattern side) have substantially the same shape and size as both ends in the longitudinal direction of the reinforcing member 216. 222 g of recesses (reinforcing member support portions) of one or more pairs (one pair in the illustrated embodiment) for accommodating the portions) are formed. On the other hand, as shown in FIG. 7, a recess (base plate forming portion) 224a for forming the base plate 212 is formed on the lower surface of the upper mold member 224, and the base plate forming portion 224a is formed in the width direction. One or more pairs (the illustrated embodiment) for accommodating both ends (the portion opposite to the circuit pattern side) of the reinforcing member 216 having substantially the same shape and size as both ends in the longitudinal direction on both side surfaces. Then, a pair of recesses (reinforcing member support portions) are formed. The base plate 212 is formed in the space defined by the base plate forming portion 222a of the lower mold member 222 and the base forming portion 224a of the upper mold member 224. Further, when the upper mold member 224 is put on the lower mold member 222 after the reinforcing member 216 is housed in the reinforcing member support portion 222g of the lower mold member 222, the reinforcing member 216 becomes the reinforcing member support portion 222g of the lower mold member 222. And the upper mold member 224 are sandwiched by the reinforcing member support portion. By sandwiching the reinforcing member 216 in this way, the reinforcing member 216 can be accurately fixed at a predetermined position (a predetermined position in the direction along the main surface of the base plate 212 and in the thickness direction). Since the other configurations are substantially the same as the mold used for manufacturing the metal-ceramic bonded substrate of the first embodiment described above, 200 is added to the reference numerals and the description thereof will be omitted.

[Third Embodiment]
9A-9C show a third embodiment of the metal-ceramic bonded substrate according to the present invention, and FIGS. 10 and 11A-11E show molds used for manufacturing the metal-ceramic bonded substrate. Shown.

As shown in FIGS. 9A to 9C, in the third embodiment of the metal-ceramics bonded substrate according to the present invention, the electronic component 318 is directly bonded to the upper surface of the metal plate 314 for the circuit pattern. Since the other configurations are substantially the same as those of the metal-ceramics bonded substrate of the first embodiment described above, 300 is added to the reference numerals and the description thereof will be omitted.

In the metal-ceramics bonded substrate of the present embodiment, the electronic component 318 and the ceramics substrate 310 are arranged apart from each other in the mold 320 as shown in FIG. 10, and one surface of the electronic component 318 and the ceramics substrate 310 are arranged. It can be manufactured by pouring a molten metal of aluminum or an aluminum alloy and cooling it so as to come into contact with the portion corresponding to the base plate 312 on both sides of the circuit pattern and the metal plate 314 for the circuit pattern.

As shown in FIGS. 11A to 11E, in the mold 320 used for manufacturing the metal-ceramics bonded substrate of the present embodiment, electronic components 318 are abbreviated on the bottom surfaces of the metal plate forming portions 322c for circuit patterns. One or more recesses (electronic component accommodating portions) 322h having the same shape and size (one in each of the illustrated embodiments) are formed. Since the other configurations are substantially the same as the mold used for manufacturing the metal-ceramic bonded substrate of the first embodiment described above, 300 is added to the reference reference numerals and the description thereof will be omitted.

In this way, by directly joining the electronic component 318 to the metal plate 314 for a circuit pattern made of aluminum or an aluminum alloy without using solder, the thermal conductivity can be improved and the heat dissipation can be improved. In addition, voids that are likely to occur when solder is used are less likely to occur, and aluminum or an aluminum alloy has a higher thermal conductivity than solder, so that heat dissipation and reliability can be improved. Moreover, since it is not necessary to use high-temperature solder, which is difficult to make lead-free, lead-free soldering can be achieved. Further, it is not necessary to plate the circuit pattern metal plate 314 in order to improve the solder wettability. The electronic component 318 may be any electronic component such as a semiconductor chip, a resistor chip, or a capacitor chip as long as it is made of a substance that does not react with a molten metal to form an alloy or compound.

[Fourth Embodiment]
12A to 12C show a fourth embodiment of the metal-ceramics bonded substrate according to the present invention, and FIG. 13 shows a mold used for manufacturing the metal-ceramics bonded substrate.

As shown in FIGS. 12A to 12C, in the fourth embodiment of the metal-ceramics bonded substrate according to the present invention, a plurality of plate-shaped fins 412a having a substantially rectangular planar shape are substantially parallel to each other and at regular intervals. Separately, they are integrally formed on the bottom surface of the base plate 412 so as to extend in a direction substantially perpendicular to the bottom surface. Since the other configurations are substantially the same as those of the metal-ceramics bonded substrate of the first embodiment described above, 400 is added to the reference numerals and the description thereof will be omitted.

In the metal-ceramic bonding substrate of the present embodiment, the ceramic substrate 410 is arranged in the mold 420 as shown in FIG. 13, and the portion corresponding to the base plates 412 on both sides of the Cerax substrate 410 and the metal plate 414 for the circuit pattern. It can be manufactured by pouring and cooling a molten aluminum or aluminum alloy so that they come into contact with each other.

As shown in FIG. 13, in the mold 420 used for manufacturing the metal-ceramics bonded substrate of the present embodiment, recesses (heat dissipation) for forming a plurality of plate-shaped fins 412a on the lower surface of the upper mold member 424. Fin forming portion) 424a is formed. The base plate 412 is integrally formed with the plate-shaped fins 412a in the space defined by the base plate forming portion 422a of the lower mold member 422 and the heat radiation fin forming portion 424a of the upper mold member 424. There is. Since the other configurations are substantially the same as the mold used for manufacturing the metal-ceramic bonded substrate of the first embodiment described above, 400 is added to the reference reference numerals and the description thereof will be omitted.

[Fifth Embodiment]
14A-14C show a fifth embodiment of the metal-ceramic bonded substrate according to the present invention.

As shown in FIGS. 14A to 14C, in the fifth embodiment of the metal-ceramics bonded substrate according to the present invention, a large number of columnar protrusions 512a (as heat radiation fins) protrude from the bottom surface of the base plate 512. Is integrally formed with the base plate 512.

Each columnar protrusion 512a has a substantially cylindrical shape or a substantially truncated cone shape (a shape in which the upper end of the substantially cone is cut substantially parallel to the bottom surface) and extends in a direction substantially perpendicular to the bottom surface of the base plate 512. .. Further, in the columnar protrusions 512a, a plurality of rows of columnar protrusions 512a arranged in a row at predetermined intervals are parallel to each other and half pitches with the rows of adjacent columnar protrusions 512a (adjacent columnar protrusions). It is arranged so as to be offset by half the distance between the center lines of the portions 512a (the axis on which the columnar protrusions 512a extend), so that more columnar protrusions 512a are arranged while ensuring a space between adjacent columnar protrusions 512a. However, as long as a large number of columnar protrusions 512a can be arranged while ensuring a space between adjacent columnar protrusions 512a, other arrangements may be used. Since the other configurations are substantially the same as those of the metal-ceramics bonded substrate of the first embodiment described above, 500 is added to the reference numerals and the description thereof will be omitted.

The metal-ceramics bonded substrate of the present embodiment forms a large number of columnar protrusions 512a in place of the recesses (radiating fin forming portions) 424a for forming the plurality of plate-shaped fins 412a of the mold 420 shown in FIG. The ceramic substrate was placed in the same mold as the mold 420 shown in FIG. 13, except that the concave portion (columnar protrusion forming portion) was formed on the lower surface of the upper mold member 224, and the base plates 512 on both sides of the Cerax substrate were formed. It can be manufactured by pouring a molten metal of aluminum or an aluminum alloy and cooling it so as to come into contact with the portion corresponding to the metal plate for the circuit pattern.

In addition, the above-mentioned first to fifth embodiments may be combined. For example, the elongated substrate support portion 122f of the modified example of the first embodiment may be applied to a mold used for manufacturing the metal-ceramics bonded substrate of the second to fifth embodiments. Further, the reinforcing member 216 of the second embodiment may be applied to the metal-ceramics bonded substrate of the third to fifth embodiments. Further, the electronic component accommodating portion 322h of the third embodiment may be applied to a mold used for manufacturing the metal-ceramic bonded substrate of the second, fourth and fifth embodiments.

For example, as a modification of the fifth embodiment of the metal-ceramic bonded substrate according to the present invention, as shown in FIGS. 15A to 15C, 16 and 17A to 17E, the first embodiment and its modification. The example, the second embodiment, and the fifth embodiment may be combined. The configuration of this modification is to manufacture the metal-ceramic bonding substrate and the metal-ceramic bonding substrate of the first embodiment and the modification thereof, the second embodiment, and the fifth embodiment described above. Since it is substantially the same as the configuration of the mold used for the above, 600 is added to the reference code for the part corresponding to the first embodiment, and the part corresponding to the modification of the first embodiment is referred to. The description will be omitted by adding 500 to the reference numerals, adding 400 to the reference code to the portion corresponding to the second embodiment, and adding 100 to the reference reference numeral to the portion corresponding to the fifth embodiment. Further, reference numeral 612c indicates a recess formed in the base plate 612 corresponding to the elongated substrate support portion 622f, and reference numeral 624b indicates a recess (heat dissipation pin forming portion). The height of the elongated substrate support portion 622f is higher than that of the longitudinal substrate support portion 622d and higher than that of the upper surface of the ceramic substrate 610, and when the molten metal is poured into the mold 620, the ceramic substrate 610 It can also act as a degassing portion for releasing gas that tends to remain between the reinforcing member 616 and the reinforcing member 616 to the outside to prevent the generation of voids (voids).

Hereinafter, examples of the metal-ceramics bonded substrate and the method for manufacturing the same according to the present invention will be described in detail.

[Example 1]
An AlN plate as a ceramic substrate having a length of 77 mm, a width of 56 mm, and a thickness of 0.6 mm is housed in a mold similar to the mold 20 shown in FIG. 2, and then heated in a state where the inside of the mold is in a nitrogen atmosphere to make aluminum. The molten metal is poured into the mold while removing the oxide film on the surface, and then the mold is cooled to solidify the molten metal, thereby forming a peripheral portion (1.5 mm wide portion) of one surface of the ceramic substrate. A base plate (length 79 mm, width 58 mm, thickness 1.7 mm) was integrally formed on the entire surface of the side surface and the other surface, and was formed on the peripheral edge of one surface of the ceramics. A base-integrated metal-ceramics bonded substrate was produced in which an aluminum plate for a circuit pattern having a length of 70 mm, a width of 49 mm, and a thickness of 0.6 mm was formed on one surface of the ceramic substrate (2 mm) away from the portion). .. The width of the base plate formed on the side surface of the ceramic substrate (distance from the side surface of the ceramic substrate to the side surface of the base plate) is 1 mm, and the thickness of the base plate formed on the other surface is 0.5 mm. The thickness of the base plate formed on the peripheral edge of the surface was 0.6 mm.

Regarding this metal-ceramics bonded substrate, the maximum value of the three-dimensional height difference map by a laser microscope was regarded as the warp, and the warp of one surface side (aluminum plate side for circuit pattern) of the ceramics substrate was measured. When the other surface side (base plate side) was warped in a convex shape, it was + (plus), and it was about +130 μm.

[Comparative Example 1]
The same as in Example 1 except that the base plate is not formed on the peripheral edge of one surface of the ceramic substrate and the distance between the base plate on one surface side of the ceramic substrate and the aluminum plate for the circuit pattern is 3.5 mm. A metal-ceramics bonded substrate with an integrated base was produced by the method, and the warpage was measured and found to be about +180 μm.

[Example 2]
The AlN plate as a ceramic substrate having a length of 71 mm × width 72 mm × thickness 0.6 mm and the AlN plate as a reinforcing member having a length 71 mm × width 79 mm × thickness 0.6 mm are the same as the mold 620 shown in FIG. After being housed in the mold, the inside of the mold is heated in a nitrogen atmosphere, and the molten aluminum is poured into the mold while removing the oxide film on the surface, and then the mold is cooled to solidify the molten metal. A base plate (length 98 mm, width 78 mm, thickness 4 mm) is integrally formed on the peripheral edge of one surface of the ceramic substrate (the portion having a width of 1 mm) and the entire surface of the side surface and the other surface. Aluminum plate for circuit pattern with a length of 65 mm x width of 66 mm x thickness of 0.4 mm on one surface of the ceramic substrate at a distance (2 mm) from the plate (the portion formed on the peripheral edge of one surface of the ceramic substrate). Was formed, and a base-integrated metal-ceramic bonded substrate was produced in which the reinforcing member was arranged inside the base plate at a distance of 1.9 mm from the ceramic substrate and substantially parallel to the ceramic substrate. The width of the base plate formed on the side surface of the ceramic substrate (distance from the side surface of the ceramic substrate to the side surface of the base plate) is 13.5 mm on both side surfaces in the length direction and 3 mm on both side surfaces in the width direction. The thickness of the base plate formed on the other surface (including the reinforcing member inside) was 3 mm, and the thickness of the base plate formed on the peripheral edge of one surface was 0.4 mm. Further, the height of the columnar protrusions (radiating pins) formed on the surface of the base plate opposite to the aluminum plate for the circuit pattern was 8 mm, the diameter was 2 mm, the interval was 3 mm, and the number was 525.

Further, after the base plate and the aluminum plate for the circuit pattern were directly bonded to the ceramic substrate, unnecessary portions of the aluminum plate for the circuit pattern were removed by etching to form a circuit pattern (consisting of two islands). A metal-ceramic bonded substrate with an integrated base was produced in this way, and the warpage was measured by the same method as in Example 1 and found to be about +100 μm.

In addition, a screw hole with a diameter of 6 mm centered at a position 6 mm away from each end in the length direction and the width direction at each of the four corners of the base plate of this base-integrated metal-ceramic joint substrate is machined. The base plate is formed by processing so as to extend in the thickness direction, the water-cooled jacket is screwed so as to cover the columnar protrusion (radiation pin), and water flows into the space defined by the metal-ceramic joint substrate and the water-cooled jacket. As a result, there was no problem of water leakage.

[Comparative Example 2]
By the same method as in Example 2 except that the base plate is not formed on the peripheral edge of one surface of the ceramic substrate and the distance between the base plate on one surface side of the ceramic substrate and the aluminum plate for the circuit pattern is set to 3 mm. , A metal-ceramics bonded substrate with an integrated base was prepared, and the warpage was measured. As a result, it was ± 100 μm, and the warp direction was not stable. Further, when the water-cooled jacket was screwed and water was allowed to flow by the same method as in Example 2, water leakage occurred.

[Example 3]
The AlN plate as a ceramic substrate having a length of 70 mm × width 71 mm × thickness 0.6 mm and the AlN plate as a reinforcing member having a length 70 mm × width 84 mm × thickness 0.6 mm are the same as the mold 620 shown in FIG. After being housed in the mold, the inside of the mold is heated in a nitrogen atmosphere, and the molten aluminum is poured into the mold while removing the oxide film on the surface, and then the mold is cooled to solidify the molten metal. A base plate (length 98 mm, width 81 mm, thickness 3.9 mm) is integrally formed on the peripheral edge (a portion having a width of 0.4 mm) of one surface of the ceramic substrate and the entire surface of the side surface and the other surface. A circuit having a length of 65 mm, a width of 66 mm, and a thickness of 0.6 mm is separated from the base plate (a portion formed on the peripheral edge of one surface of the ceramic substrate) by (2 mm) and is provided on one surface of the ceramic substrate. An aluminum plate for patterning was formed, and a base-integrated metal-ceramic joint substrate was produced in which a reinforcing member was arranged inside the base plate at a distance of 1.5 mm from the ceramic substrate and substantially parallel to the ceramic substrate. The width of the base plate formed on the side surface of the ceramic substrate (distance from the side surface of the ceramic substrate to the side surface of the base plate) is 14 mm on both side surfaces in the length direction, 5 mm on both side surfaces in the width direction, and the other. The thickness of the base plate formed on the surface (including the reinforcing member inside) was 2.7 mm, and the thickness of the base plate formed on the peripheral edge of one surface was 0.6 mm. Further, the height of the columnar protrusions (radiating pins) formed on the surface of the base plate opposite to the aluminum plate for the circuit pattern was 8 mm, the diameter was 2 mm, the interval was 3 mm, and the number was 525.

When the warp of each of the 30 base-integrated metal-ceramic bonded substrates produced in this manner was measured by the same method as in Example 1, the average was about +150 μm. Moreover, when the cross section of the produced metal-ceramics bonded substrate integrated with the base was observed with an X-ray inspection apparatus, no void was confirmed.

In addition, a screw hole with a diameter of 6 mm centered at a position 6 mm away from each end in the length direction and the width direction at each of the four corners of the base plate of this base-integrated metal-ceramic joint substrate is machined. The base plate is formed by processing so as to extend in the thickness direction, the water-cooled jacket is screwed so as to cover the columnar protrusion (radiation pin), and water flows into the space defined by the metal-ceramic joint substrate and the water-cooled jacket. As a result, there was no problem of water leakage.

A mold similar to the mold 620 shown in FIG. 16 was used except that the height of the elongated substrate support portion 622f on the high side was the same height as the longitudinal substrate support portion 622d and lower than the upper surface of the ceramic substrate 610. When 30 base-integrated metal-ceramic bonded substrates were produced by the same method as in Example 3 and the occurrence of warpage and voids was confirmed, the warp was about +150 μm on average, but all of them were ceramics. Voids were confirmed between the substrate and the reinforcing member.

[Example 4]
The AlN plate as a ceramic substrate having a length of 70 mm × width 71 mm × thickness 0.6 mm and the AlN plate as a reinforcing member having a length 70 mm × width 84 mm × thickness 0.6 mm are the same as the mold 220 shown in FIG. After being housed in the mold, the inside of the mold is heated in a nitrogen atmosphere, and the molten aluminum is poured into the mold while removing the oxide film on the surface, and then the mold is cooled to solidify the molten metal. A base plate (length 98 mm, width 81 mm, thickness 3.9 mm) is integrally formed on the peripheral edge of one surface (a portion having a width of 0.4 mm) and the entire surface of the side surface and the other surface. A circuit having a length of 65 mm, a width of 66 mm, and a thickness of 0.6 mm is separated from the base plate (a portion formed on the peripheral edge of one surface of the ceramic substrate) by (2 mm) and is provided on one surface of the ceramic substrate. An aluminum plate for patterning was formed, and a base-integrated metal-ceramic joint substrate was produced in which a reinforcing member was arranged inside the base plate at a distance of 1.5 mm from the ceramic substrate and substantially parallel to the ceramic substrate. The width of the base plate formed on the side surface of the ceramic substrate (distance from the side surface of the ceramic substrate to the side surface of the base plate) is 14 mm on both side surfaces in the length direction, 5 mm on both side surfaces in the width direction, and the other. The thickness of the base plate formed on the surface (including the reinforcing member inside) was 2.7 mm, and the thickness of the base plate formed on the peripheral edge of one surface was 0.6 mm.

When the warp of the base-integrated metal-ceramic bonded substrate thus produced was measured by the same method as in Example 1, it was about +150 μm.

In addition, a screw hole with a diameter of 6 mm centered at a position 6 mm away from each end in the length direction and the width direction at each of the four corners of the base plate of this base-integrated metal-ceramic joint substrate is machined. The base plate is formed by processing so as to extend in the thickness direction, the water-cooled jacket is screwed so as to cover the columnar protrusion (radiation pin), and water flows into the space defined by the metal-ceramic joint substrate and the water-cooled jacket. As a result, there was no problem of water leakage.

10, 210, 310, 410, 510, 610 Ceramic substrates 12, 212, 312, 412, 512, 612 Base plates 12b, 212b, 312b, 412b, 612b, 612b Recesses 14, 214, 314, 414, 514, 614 Circuits Metal plate for pattern 20, 120, 220, 320, 420, 620 Mold 22, 122, 222, 322, 422, 622 Lower mold members 22a, 122a, 222a, 322a, 422a, 622a Base plate forming portions 22b, 122b, 222b, 222b, 422b, 622b Raised parts 22c, 122c, 222c, 222c, 422c, 622c Recessed parts (metal plate forming part for circuit pattern)
22d, 122d, 222d, 322d, 422d, 622d Longitudinal substrate support 22e, 122e, 222e, 222e, 622e, 622e Width substrate support 24, 124, 224, 324, 424, 624 Upper mold member 122f, 622f elongated Board support part 222g, 622g Recessed part (reinforcing member support part)
224a, 624a recesses (base plate forming part)
216, 616 Reinforcement member 318 Electronic component 322h Recess (electronic component accommodating part)
412a Plate-shaped fin 424a Recess (radiation fin forming part)
512a, 612a Columnar protrusion 612c Recess 624b Recess (heat dissipation pin forming part)

Claims (11)

The ceramic substrate and the reinforcing member are arranged apart from each other in the mold composed of the upper mold member and the lower mold member, and aluminum or aluminum is contacted with a predetermined portion on both sides of the ceramic substrate and the entire surface of the reinforcing member. By pouring the molten metal of the alloy and then cooling and solidifying the molten metal, a base plate made of aluminum or an aluminum alloy is formed on the peripheral edge and the side surface of one surface of the ceramic substrate and the entire surface of the other surface. ceramic substrate is bonded directly to, spaced Rutotomoni is bonded directly to the base plate reinforcement member as reinforcing member in the mold is surrounded on the base plate, a metal plate for a circuit pattern made of aluminum or an aluminum alloy from the base plate This is a method for manufacturing a metal-ceramic bonded substrate, which is formed on one surface of the ceramic substrate and directly bonded to the ceramic substrate. The end portion of the reinforcing member is sandwiched between the upper mold member and the lower mold member. The reinforcing member is supported by the mold, and the bottom surface and the side surface of the end portion of the ceramic substrate are in contact with and supported by the plurality of substrate support portions formed so as to project from the bottom surface of the lower mold member. Manufacture of a metal-ceramic bonded substrate, characterized in that the upper surface of at least one portion of the ceramic substrate that abuts on the side surface of the end portion is higher than the upper surface of the ceramic substrate supported by a plurality of substrate supporting portions. Method. The method for manufacturing a metal-ceramic bonded substrate according to claim 1 , wherein the reinforcing member is made of a metal or ceramic material having a melting point higher than that of the base plate material. When the ceramic substrate is arranged in the mold, the ceramic substrate and the electronic component are arranged apart from each other in the mold, and when the molten metal is poured, the molten metal is placed on one surface of the electronic component. The invention according to claim 1 or 2 , wherein when the metal plate for the circuit pattern is formed and directly bonded to the ceramic substrate, the electronic component is directly bonded to the metal plate for the circuit pattern. Method of manufacturing metal-ceramics bonded substrate. When the base plate is formed and directly bonded to the ceramic substrate, a plurality of base plates are arranged parallel to each other and separated from each other at regular intervals on the surface of the base plate opposite to the metal plate for circuit pattern. The method for manufacturing a metal-ceramic bonded substrate according to any one of claims 1 to 3 , wherein the plate-shaped fins are integrally formed with the base plate. When the base plate is formed and directly bonded to the ceramic substrate, a large number of columnar protrusions projecting apart from each other on the surface of the base plate opposite to the metal plate for the circuit pattern are formed with the base plate. The method for manufacturing a metal-ceramic bonded substrate according to any one of claims 1 to 4 , wherein the metal-ceramic bonded substrate is integrally formed. The present invention is characterized in that after the base plate and the metal plate for a circuit pattern are directly bonded to the ceramics substrate, unnecessary portions of the metal plate for the circuit pattern are removed by etching to form a desired circuit pattern. Item 8. The method for manufacturing a metal-ceramics bonded substrate according to any one of Items 1 to 5 . A ceramic substrate, a base plate made of aluminum or an aluminum alloy directly bonded to the peripheral edge and the side surface of one surface of the ceramic substrate and the entire surface of the other surface, and one of the ceramic substrates separated from the base plate. A metal plate for a circuit pattern made of aluminum or an aluminum alloy directly bonded to a surface is provided, and a plate-shaped reinforcing member is arranged inside the base plate at a distance from the ceramic substrate and in parallel with the ceramic substrate. A metal-ceramics bonded substrate, which is directly bonded to the base plate and has a recess formed in a portion of the base plate adjacent to a side surface of the ceramics substrate, which is deeper than the thickness of the ceramics substrate. The metal-ceramic bonded substrate according to claim 7 , wherein the reinforcing member is made of a metal or ceramic material having a melting point higher than that of the base plate material. The metal-ceramic bonding substrate according to claim 7 or 8 , wherein an electronic component is directly bonded to a surface of the metal plate for a circuit pattern opposite to the ceramic substrate. A feature is that a plurality of plate-shaped fins are arranged parallel to each other and separated from each other at regular intervals on the surface of the base plate opposite to the ceramic substrate, and are integrally formed with the base plate. The metal-ceramic bonded substrate according to any one of claims 7 to 9 . Any of claims 7 to 10 , wherein a large number of columnar protrusions protruding apart from each other are integrally formed with the base plate on the surface of the base plate opposite to the ceramic substrate. The metal-ceramic bonding substrate described in C.

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