JP6345957B2 - Metal-ceramic circuit board and manufacturing method thereof - Google Patents

Description

  The present invention relates to a metal-ceramic circuit board in which a metal circuit board is bonded to a ceramic substrate and a manufacturing method thereof, and more particularly to a metal-ceramic circuit board used for a power module and the like and a manufacturing method thereof.

  Conventionally, as a method of manufacturing a metal-ceramic circuit board used for a power module or the like, a metal plate is joined to a ceramic substrate by pouring a molten metal onto the ceramic substrate and then cooling and solidifying, and then screen printing, etc. A metal-ceramic circuit board having a metal circuit board having a desired circuit pattern is manufactured by printing an etching resist having a desired circuit pattern shape, forming a circuit pattern by performing an etching process, and then removing the etching resist. There is a known method (see, for example, Patent Document 1).

  However, in the metal-ceramic circuit board used for power modules and the like, the thickness of the metal circuit board is several hundred μm or more, and the thickness of the metal circuit board of the printed circuit board using normal paper or glass epoxy as an insulating material. Since the thickness is several tens of times the thickness, the method disclosed in Patent Document 1 has a problem that the length of the skirt formed by the etching process and the amount of side etching increase. In particular, when the thickness of the metal circuit board is 0.4 mm or more and is larger than the distance between the side surfaces facing each other of the adjacent circuit pattern, due to the difference in etching rate between the thickness direction of the metal plate and the side surface of the metal plate, etc. The dimensional difference between the top (top surface on which a chip such as a semiconductor is mounted) and the bottom (bottom surface in contact with the ceramic substrate) of the circuit pattern becomes large, and a circuit pattern having a desired dimension cannot be obtained. Further, the thicker the metal circuit board is, the longer the etching process time is, the more man-hours are required, the cost is increased, and the resistance of the etching resist must be taken into consideration.

  In order to solve such a conventional problem, the shape of the metal plate for the circuit joined to the ceramic substrate is made to be similar to the circuit pattern in advance by bringing the molten metal into contact with the ceramic substrate and then cooling and solidifying it. The etching processing time for forming the metal circuit board having a desired circuit pattern by etching the circuit metal board can be reduced, and a fine pattern can be formed even when the circuit metal plate is thick. A metal-ceramic circuit board manufacturing method that can be used has been proposed (see, for example, Patent Document 2).

JP 2002-76551 A (paragraph numbers 0030 and 0048) Japanese Patent Laying-Open No. 2005-93965 (paragraph numbers 0006-0007)

  In recent years, there has been a demand for metal-ceramic circuit boards in which the thickness of the metal circuit board is further increased to 1 mm or more, or the area of the skirt formed by the etching process is further shortened to reduce the area.

  However, in the method of Patent Document 2, an etching resist is printed on a predetermined portion substantially corresponding to the circuit pattern on the upper surface of the circuit metal plate bonded to the ceramic substrate, and the etching process is performed with the etching solution. When the thickness of the circuit board becomes thicker than 1 mm, the area of the side surface of the metal circuit board that comes into contact with the etching solution during the etching process increases, and the dimensional difference between the top and the bottom of the circuit pattern increases and the circuit with the desired dimensional accuracy. The pattern cannot be obtained.

  Therefore, in view of such a conventional problem, the present invention has a small dimensional difference between the top and bottom of the circuit pattern even if the metal circuit board is thick, and the metal circuit board having a circuit pattern with a desired dimensional accuracy is applied to the ceramic substrate. It is an object of the present invention to provide a bonded metal-ceramic circuit board and a method for manufacturing the same.

  As a result of intensive studies to solve the above problems, the present inventors have a shape similar to a circuit pattern, and a thickness other than a portion substantially corresponding to the circuit pattern is thinner than a thickness of a portion substantially corresponding to the circuit pattern. After joining the formed metal plate to the ceramic substrate and applying the resist to substantially the entire surface of the metal plate, at least a part of the resist applied to the surface of the portion other than the portion substantially corresponding to the circuit pattern of the metal plate By removing the part other than the part that substantially corresponds to the circuit pattern of the metal plate by etching, the dimensional difference between the top and bottom of the circuit pattern is small even if the metal circuit board is thick, and the desired dimensional accuracy is achieved. It has been found that a metal-ceramic circuit board in which a metal circuit board having a circuit pattern is bonded to a ceramic board can be manufactured, and the present invention has been completed. It was.

  That is, the metal-ceramic circuit board manufacturing method according to the present invention has a shape similar to a circuit pattern, and the thickness other than the portion substantially corresponding to the circuit pattern is thinner than the thickness of the portion substantially corresponding to the circuit pattern. After joining the formed metal plate to the ceramic substrate and applying a resist to almost the entire surface of the metal plate, at least part of the resist applied to the surface of the portion other than the portion substantially corresponding to the circuit pattern of the metal plate is removed. Etching treatment is used to remove portions other than portions substantially corresponding to the circuit pattern of the metal plate.

  In this metal-ceramic circuit board manufacturing method, the metal plate and the ceramic substrate are joined by bringing the molten metal into contact with one surface of the ceramic substrate and then cooling and solidifying to form the metal plate. Is preferred. In addition, the metal plate and the ceramic substrate are joined using a mold in which a ceramic substrate housing portion having a shape and size substantially equal to the ceramic substrate and a metal plate forming portion adjacent to the ceramic substrate housing portion is formed. The ceramic substrate is accommodated in the ceramic substrate accommodating portion of the mold, and the molten metal is poured into the metal plate forming portion so as to contact one surface of the ceramic substrate, and then cooled and solidified to form the metal plate. Is preferably performed. In this case, it is preferable that the metal plate forming portion has a shape similar to the circuit pattern of the metal circuit board and having a depth other than a portion substantially corresponding to the circuit pattern shallower than a depth of the portion substantially corresponding to the circuit pattern. . Further, when the molten metal is brought into contact with one surface of the ceramic substrate, the molten metal is brought into contact with the other surface of the ceramic substrate and cooled to solidify to form a metal member on the other surface of the ceramic substrate. You may join. The molten metal is preferably a molten aluminum or aluminum alloy.

  In the method for producing a metal-ceramic circuit board, it is preferable to remove the resist before the etching process by laser processing. In addition, when removing a portion other than a portion substantially corresponding to the circuit pattern of the metal plate by etching processing, a concave portion curved and curled into a portion not covered with the resist of the portion corresponding to the circuit pattern of the metal plate Preferably formed. Moreover, it is preferable that the thickness of the part substantially corresponding to the circuit pattern of a metal plate is 0.4 mm or more.

  In the metal-ceramic circuit board according to the present invention, a metal circuit board is bonded to one side of the ceramic board, and the side surface of the circuit pattern is formed on the lower side portion of the side face of the adjacent circuit pattern of the metal circuit board. A concave portion is formed that extends in the longitudinal direction of the circuit pattern and is curved to bend inside the side surface of the circuit pattern.

  In this metal-ceramic circuit board, the thickness of the circuit pattern is preferably 0.4 mm or more, and the height from the upper end of the recess to the upper surface of the circuit pattern is preferably 0.1 mm or more. Moreover, it is preferable that the height of a recessed part is 0.25 mm or more, and it is preferable that the depth of a recessed part is 0.05 mm or more. The difference between the distance between the tops of the adjacent circuit patterns and the distance between the bottoms thereof is preferably less than 0.5 mm, and the ratio of the thickness of the circuit pattern to the distance between the bottoms of the adjacent circuit patterns is 0. .3 or more is preferable.

  According to the present invention, even when the metal circuit board is thick, a metal-ceramic circuit board in which the dimensional difference between the top and bottom of the circuit pattern is small and the metal circuit board having a circuit pattern with a desired dimensional accuracy is bonded to the ceramic substrate is manufactured. be able to.

  In addition, after bringing the molten metal into contact with one surface of the ceramic substrate and cooling and solidifying it, a metal plate is formed and bonded to one surface of the ceramic substrate, and a resist is applied to the surface of the metal plate. When a metal-ceramic circuit board is manufactured by forming a metal circuit board having a desired circuit pattern by etching, a fine pattern can be formed even when the metal circuit board is thick, and the etching processing time is greatly increased. It can be shortened.

It is a top view which shows the lower mold member of the casting_mold | template used for embodiment of the manufacturing method of the metal-ceramics circuit board by this invention. It is IB-IB sectional view taken on the line of FIG. 1A. It is a partially expanded view of FIG. 1B. It is sectional drawing which shows the metal-ceramics bonding board | substrate obtained by embodiment of the manufacturing method of the metal-ceramics circuit board by this invention. It is sectional drawing which shows the manufacturing process of embodiment of the manufacturing method of the metal-ceramics circuit board by this invention, and expands the part between the mutually opposing side surfaces of the adjacent circuit pattern of the metal-ceramics bonding board | substrate of FIG. FIG. 5 is a diagram illustrating a process of joining a circuit metal plate to one surface of a ceramic substrate and joining a metal base plate to the other surface. It is sectional drawing which shows the manufacturing process of embodiment of the manufacturing method of the metal-ceramics circuit board by this invention, and expands the part between the mutually opposing side surfaces of the adjacent circuit pattern of the metal-ceramics bonding board | substrate of FIG. FIG. 5 is a diagram illustrating a process of forming an etching resist on substantially the entire surface of a circuit metal plate. It is sectional drawing which shows the manufacturing process of embodiment of the manufacturing method of the metal-ceramics circuit board by this invention, and expands the part between the mutually opposing side surfaces of the adjacent circuit pattern of the metal-ceramics bonding board | substrate of FIG. FIG. 5 is a diagram illustrating a process of removing a part of an etching resist. It is sectional drawing which shows the manufacturing process of embodiment of the manufacturing method of the metal-ceramics circuit board by this invention, and expands the part between the mutually opposing side surfaces of the adjacent circuit pattern of the metal-ceramics bonding board | substrate of FIG. FIG. 5 is a diagram illustrating a process of forming a metal circuit board by removing unnecessary portions of the circuit metal board by etching treatment. It is sectional drawing which shows the manufacturing process of embodiment of the manufacturing method of the metal-ceramics circuit board by this invention, and expands the part between the mutually opposing side surfaces of the adjacent circuit pattern of the metal-ceramics bonding board | substrate of FIG. It is a figure explaining the process of peeling an etching resist. FIG. 6 is a cross-sectional view showing a modification of the manufacturing process of the embodiment of the method for manufacturing a metal-ceramic circuit board according to the present invention, and shows a portion between adjacent side surfaces of adjacent circuit patterns of the metal-ceramic bonding board of FIG. It is a figure explaining the process of expanding and removing a part of etching resist. FIG. 6 is a cross-sectional view showing a modification of the manufacturing process of the embodiment of the method for manufacturing a metal-ceramic circuit board according to the present invention, and shows a portion between adjacent side surfaces of adjacent circuit patterns of the metal-ceramic bonding board of FIG. It is a figure which expands and demonstrates the process of removing the unnecessary part of the metal plate for circuits by an etching process, and forming a metal circuit board. FIG. 6 is a cross-sectional view showing a modification of the manufacturing process of the embodiment of the method for manufacturing a metal-ceramic circuit board according to the present invention, and shows a portion between adjacent side surfaces of adjacent circuit patterns of the metal-ceramic bonding board of FIG. It is a figure explaining the process of expanding and peeling an etching resist. FIG. 7 is a cross-sectional view showing another modified example of the manufacturing process of the embodiment of the method for manufacturing a metal-ceramic circuit board according to the present invention, between adjacent side surfaces of adjacent circuit patterns of the metal-ceramic bonding board of FIG. It is a figure explaining the process of expanding a part and removing a part of etching resist. It is a figure explaining embodiment of the metal-ceramics circuit board by this invention.

  Embodiments of a method for producing a metal-ceramic circuit board according to the present invention will be described below with reference to the accompanying drawings.

  First, a ceramic substrate is placed in a mold, and molten metal is poured into it and cooled and solidified, so that one surface metal base plate of the ceramic substrate is bonded and the other surface is bonded to the circuit metal plate. -Manufacture ceramic bonded substrates.

  Examples of a lower mold member of a mold used for manufacturing the metal-ceramic bonding substrate are shown in FIGS. 1A to 1C. As shown in FIGS. 1A and 1B, the lower mold member 100 includes a bottom surface portion 100a having a substantially rectangular planar shape, and a side wall portion 100b extending vertically upward from the peripheral edge portion of the bottom surface portion 100a. On the upper surface of the bottom surface portion 100a of the lower mold member 100, one or a plurality of recesses 100c (two are shown in FIGS. 1A and 1B) having stepped side walls are formed. Each of the recesses 100c has one or a plurality of circuits (one is shown in FIGS. 1A and 1B) having a planar shape similar to the circuit pattern of the metal circuit board and a depth substantially equal to the thickness of the metal circuit board. Metal plate forming portion 100d and one or a plurality of ones having a shape and size substantially the same as the ceramic substrate formed adjacent to the circuit metal plate forming portion 100d (one is shown in FIGS. 1A and 1B) ) Ceramic substrate housing portion 100e. In the circuit metal plate forming portion 100d, as shown in FIG. 1C, the depth of the portion between the side surfaces facing each other in the adjacent circuit pattern is shallower by d than the depth of the portion that substantially corresponds to the circuit pattern of the metal circuit plate. ing. Of the space defined inside by covering the upper mold of the lower mold member 100 with an upper mold (not shown) having a substantially rectangular plane shape, the portion excluding the recess 100c of the lower mold member 100 is a metal base. It is the plate forming part 100f. The upper mold is formed with a pouring port (not shown) for pouring the molten metal into the mold. Further, the lower mold member 100 is formed with a molten metal passage (not shown) extending between the metal base plate forming portion 100f and the circuit metal plate forming portion 100d, and the ceramic substrate is placed in the ceramic substrate housing portion 100e. The metal base plate forming portion 100f and the circuit metal plate forming portion 100d communicate with each other even when they are housed.

  After the ceramic substrate is accommodated in the ceramic substrate accommodating portion 100e of the lower mold member 100 of this mold, a molten metal (such as aluminum or aluminum alloy) is poured into the metal base plate forming portion 100f (not shown). A ceramic substrate as shown in FIG. 2 and FIG. 3A is obtained by filling the molten metal up to the circuit metal plate forming portion 100d through the molten metal flow path and then cooling to solidify the molten metal (so-called molten metal bonding method). The metal base plate 14 is directly joined to one surface of the portion 10 and the other surface has a shape similar to the circuit pattern and the thickness of the portion other than the portion substantially corresponding to the circuit pattern substantially corresponds to the circuit pattern. As a result, an integrated metal / ceramic bonding substrate in which the metal plate for circuit 12 thinner than the thickness is directly bonded is obtained.

  Next, as shown in FIG. 3B, the entire surface of the circuit metal plate 12 (the entire upper surface and side surfaces of the circuit metal plate 12, that is, the circuit metal plate 12 is formed by spray coating, dip coating, electrodeposition resist coating, or the like. An etching resist 16 is applied so as to cover the upper surface and the side surface of the portion substantially corresponding to the circuit pattern and the entire surface of the portion between the side surfaces facing each other (groove portion) of the adjacent circuit pattern.

  Next, as shown in FIG. 3C, after removing only the portion of the etching resist 16 that covers the bottom surface of the portion (groove portion) between the side surfaces facing each other of the adjacent circuit pattern by laser irradiation (laser processing), FIG. As shown, the metal circuit board 12 having a desired circuit pattern is formed by performing an etching process using an etchant such as a ferric chloride solution to remove unnecessary portions of the circuit metal board 12. During this etching process (preferably by over-etching), it extends along the longitudinal direction of the side surface of the circuit pattern to the lower part of the side surface of the adjacent circuit pattern that faces each other, and inside the side surface of the circuit pattern A concave portion (bent portion) 12a that is curved so as to be curved is formed.

  Next, the etching resist 16 is peeled off to obtain a metal-ceramic circuit board having the metal circuit board 12 having a desired circuit pattern as shown in FIG. 3E. If necessary, the surface of the metal circuit board 12 may be subjected to Ni plating or the like.

  Further, as shown in FIG. 4A, a portion of the etching resist 16 that covers a portion slightly narrower than the width of the bottom surface of the portion between the adjacent side surfaces of the adjacent circuit pattern may be removed by laser irradiation. In this case, as shown in FIG. 4B and FIG. 4C, the bend 12a smaller than the bend 12a shown in FIG. 3D can be formed by etching.

  In addition, as shown in FIG. 5, the portion of the etching resist 16 covering the lower portion of the circuit patterns opposite to each other in addition to the bottom of the portion between the adjacent sides of the adjacent circuit pattern is removed by laser irradiation. May be.

  In the embodiment of the metal-ceramic circuit board according to the present invention, as shown in FIG. 6, a metal circuit board 12 is bonded to one surface of the ceramic board 10 and adjacent circuit patterns of the metal circuit board 12 face each other. A concave portion (bent portion) 12a that extends in the longitudinal direction of the side surface of the circuit pattern and is curved to the inside of the side surface of the circuit pattern is formed in the lower portion of the side surface.

The metal - the thickness T of the ceramic circuit board of the metal circuit plate 12, hollowed portion the height h ₁ of the _12a, gouged portion 12a h ₂ height to the upper surface of the metal circuit plate 12 from the upper end _of circuit When the distance (insulation distance) between the bottoms of the patterns is D _B , the distance between the tops of adjacent circuit patterns is D _T , and the depth of the bent portion 12 a is d ₁ , the thickness T of the circuit pattern is preferably 0.4 mm or more, more preferably 0.6 mm or more, and most preferably 1 mm or more. The height h ₁ of the bent portion 12a is preferably 0.25 mm or more, and the upper surface of the circuit pattern from the upper end of the bent portion 12a. The height h ₂ is preferably 0.1 mm or more, more preferably 0.2 mm or more, most preferably 0.3 mm or more, and the depth d ₁ of the kinked portion 12a is preferably 0.05 mm or more. Adjacent circuit path And the difference between the distance _{D B} between bottom distance _{D T} between top over emissions _| D T -D _B | is preferably less than 0.5 mm, more preferably less than 0.3 mm, the adjacent circuit patterns the ratio T / D _B of the thickness T of the circuit pattern with respect to the distance D _B between bottom, is preferably 0.3 or more, more preferably 0.8 or more, more preferably 1 or more, most preferably 2 or more .

  When manufacturing a power module using a metal-ceramic circuit board, a semiconductor circuit or electronic component is mounted on a metal circuit board bonded to one surface of the ceramic substrate of the metal-ceramic circuit board, and then molded and sealed with an insulating resin. It has stopped. In order to prevent the mold resin from being peeled off from the metal-ceramic circuit board when the power module is used in an environment with high vibration (such as in-vehicle) or a high heat environment, A concave portion or a convex portion is formed on the surface or side surface of the metal base plate bonded to the surface of the metal base plate to improve the adhesion between the metal-ceramic circuit board and the mold resin. However, the concave and convex portions on the surface and side surfaces of the metal base plate cannot be applied to a baseless module structure without the metal base plate, and must be formed in a separate process. Become high. On the other hand, the metal-ceramic circuit board according to the embodiment of the present invention can improve the adhesion with the mold resin by the bend portion 12a formed on the side surface of the metal circuit board 12. It can be applied to a non-baseless module structure, and it is not necessary to form the bent portion 12a in a separate process, and can be manufactured at low cost.

  Examples of the metal-ceramic circuit board and the manufacturing method thereof according to the present invention will be described in detail below.

[Example 1]
On the bottom surface of the lower mold member, the thickness of the portion substantially corresponding to the circuit pattern is 0.8 mm, the thickness of the portion between the adjacent side surfaces of the adjacent circuit pattern is 0.3 mm, and the distance between them (Circuit metal plate forming portion which is a concave portion having a shape and size substantially equal to a circuit metal plate whose width between the side surfaces (grooves) between adjacent side surfaces of adjacent circuit patterns is 2 mm, Adjacent to the upper part of the circuit metal plate forming portion, a ceramic substrate housing portion is formed which is a recess having a shape and size substantially equal to a ceramic substrate having a size of 71 mm × 70 mm × 0.6 mm. A metal base plate forming portion is formed adjacent to the upper portion of the portion, and a molten metal flow path extending between the metal base plate forming portion and the circuit metal plate forming portion is formed (the mold shown in FIGS. 1A to 1C). A carbon mold (with the same shape as 100) was prepared.

  An aluminum nitride substrate having a size of 71 mm × 70 mm × 0.6 mm is accommodated in the ceramic substrate accommodating portion of the lower mold member of this mold, and the upper mold is covered and sealed, and then aluminum is introduced into the metal base plate forming portion from the molten metal opening. As shown in FIG. 2 and FIG. 3A, the molten metal is poured, filled with the molten metal to the circuit metal plate forming portion through the molten metal flow path, and then cooled to solidify the molten metal. As a result, the metal base plate 14 was directly bonded to one surface of the circuit board 10, and an integrated metal / ceramic bonding substrate having the circuit metal plate 12 having a shape similar to the circuit pattern directly bonded to the other surface was obtained.

  Next, as shown in FIG. 3B, the entire surface of the circuit metal plate 12 (the upper surface and the side surface of the circuit metal plate 12 substantially corresponding to the circuit pattern, and the portion between the adjacent side surfaces of the circuit pattern (groove portion). The etching resist 16 was applied by spray coating so as to cover the entire bottom surface of ().

  Next, as shown in FIG. 4A, a portion (a portion having a width of 1.6 mm at the center of the bottom surface) that is slightly narrower than the width (2 mm) of the bottom surface of the portion (groove portion) between the adjacent side surfaces of adjacent circuit patterns is covered. After removing only the portion of the etching resist 16 by laser processing, as shown in FIG. 4B, an unnecessary portion of the circuit metal plate 12 is removed by performing an etching process so as to be over-etched with a ferric chloride solution. To form a metal circuit board 12 having a desired circuit pattern, and extend along the longitudinal direction of the side surface of the circuit pattern to the lower portion of the side surface of the adjacent circuit pattern facing each other and inside the side surface of the circuit pattern. A concave portion (bent portion) 12a that was curved so as to be curved was formed.

  Next, the etching resist 16 was peeled off to obtain a metal-ceramic circuit board having a metal circuit board 12 having a desired circuit pattern as shown in FIG. 4C.

The metal circuit board 12 of the metal-ceramic circuit board thus obtained has a thickness T of the metal circuit board 12 of 0.8 mm, a height h ₁ of the bent part 12a of 0.4 mm, and a bent part 12a. the upper end of the to the upper surface of the metal circuit plate 12 height _{h 2} is 0.4mm, the distance between the bottom of the adjacent circuit patterns (insulation distance) _{D B} is 2.2 mm, the distance _{D T} between the top 2. 2 mm, the depth d ₁ of the bent portion 12a was 0.08 mm, | D _T −D _B | = 0, T / D _B = 0.36.

[Example 2]
A metal-ceramic circuit board was obtained in the same manner as in Example 1 except that an appropriate etching treatment was performed so as not to cause over-etching.

Metal obtained in this embodiment - the metal circuit board 12 of the ceramic circuit board, the thickness T is 0.8mm metal circuit board 12, the gouged portion 12a of a height _{h 1} is 0.3 mm, gouged portion 12a the upper end of the to the upper surface of the metal circuit plate 12 height _{h 2} is 0.5mm, the distance between the bottom of the adjacent circuit patterns (insulation distance) _{D B} is 2 mm, the distance _{D T} between the top 2.2 mm, the depth _{d 1} of the gouged portion 12a is _{0.06mm, | D T -D B |} = 0.2, was T / D B = 0.40.

[Example 3]
The thickness of the portion substantially corresponding to the circuit pattern is 0.4 mm, the thickness of the portion between the adjacent side surfaces of the adjacent circuit patterns is 0.2 mm, and the distance between them (the adjacent circuit patterns are opposed to each other) A lower mold member in which a circuit metal plate forming portion, which is a recess having a shape and size substantially equal to a circuit metal plate having a width between the side surfaces (grooves) of 0.3 mm, is formed on the bottom surface. The portion of the etching resist 16 that covers a portion (a portion having a width of 0.1 mm at the center of the bottom surface) narrower than the width (0.3 mm) of the bottom surface of the portion (groove portion) between the opposite side surfaces of the adjacent circuit pattern A metal-ceramic circuit board was obtained in the same manner as in Example 1 except that only this was removed by laser processing.

Metal obtained in this embodiment - the metal circuit board 12 of the ceramic circuit board, the thickness T is 0.4mm metal circuit board 12, the gouged portion 12a of a height _{h 1} is 0.3 mm, gouged portion 12a the upper end of the to the upper surface of the metal circuit plate 12 height _{h 2} is 0.1mm, the distance between the bottom of the adjacent circuit patterns (insulation distance) _{D B} is 0.5 mm, the distance _{D T} between the top 0. 5 mm, the depth d ₁ of the bent portion 12a was 0.07 mm, | D _T −D _B | = 0, and T / D _B = 0.80.

[Example 4]
The thickness of the portion substantially corresponding to the circuit pattern is 0.4 mm, the thickness of the portion between the side surfaces of the adjacent circuit patterns facing each other is 0.3 mm, and the distance between them (the adjacent circuit patterns facing each other) A lower mold member in which a circuit metal plate forming portion, which is a recess having a shape and size substantially equal to a circuit metal plate having a width between the side surfaces (grooves) of 0.3 mm, is formed on the bottom surface. The portion of the etching resist 16 that covers a portion (a portion having a width of 0.1 mm at the center of the bottom surface) narrower than the width (0.3 mm) of the bottom surface of the portion (groove portion) between the opposite side surfaces of the adjacent circuit pattern A metal-ceramic circuit board was obtained by the same method as in Example 2 except that only this was removed by laser processing.

Metal obtained in this embodiment - the metal circuit board 12 of the ceramic circuit board, the thickness T is 0.4mm metal circuit board 12, the gouged portion 12a of a height _{h 1} is 0.3 mm, gouged portion 12a the upper end of the to the upper surface of the metal circuit plate 12 height _{h 2} is 0.1mm, the distance between the bottom of the adjacent circuit patterns (insulation distance) _{D B} is 0.3 mm, the distance _{D T} between the top 0. 3 mm, the depth d ₁ of the bent portion 12a was 0.06 mm, | D _T −D _B | = 0, and T / D _B = 1.33.

[Example 5]
The thickness of the portion substantially corresponding to the circuit pattern is 1.1 mm, the thickness of the portion between the side surfaces of the adjacent circuit patterns facing each other is 0.8 mm, and the distance between them (the adjacent circuit patterns facing each other) Lower mold member in which a circuit metal plate forming portion, which is a concave portion having a shape and size substantially equal to a circuit metal plate having a width between bottom surfaces (grooves) of 0.4 mm, is formed on the bottom surface. A portion of the etching resist 16 that covers a portion (a portion having a width of 0.1 mm at the center of the bottom surface) that is narrower than the width (0.4 mm) of the bottom surface of the portion (groove portion) between the opposing side surfaces of the adjacent circuit pattern A metal-ceramic circuit board was obtained in the same manner as in Example 1 except that only this was removed by laser processing.

Metal obtained in this example - the metal circuit board 12 of the ceramic circuit board, the thickness T is 1.1mm metal circuit board 12, the height _{h 1} of the gouged portion 12a is 1 mm, the upper end of the hollowed portion 12a the height _{h 2} is 0.1mm to the upper surface of the metal circuit board 12 from the distance between the bottom of the adjacent circuit patterns (insulation distance) _{D B} is 0.6 mm, the distance _{D T} between the top 0.6 mm, the depth _{d 1} of the gouged portion 12a is _{0.34mm, | D T -D B |} = 0, was T / D B = 1.83.

[Example 6]
The thickness of the portion substantially corresponding to the circuit pattern is 2.1 mm, the thickness of the portion between the side surfaces of the adjacent circuit patterns facing each other is 0.4 mm, and the distance between them (the adjacent circuit patterns facing each other) Uses a lower mold member in which a circuit metal plate forming portion, which is a recess having a shape and size approximately equal to a circuit metal plate having a width between the side surfaces (grooves) of 2 mm, is formed on the bottom surface. Then, only the portion of the etching resist 16 that covers a portion (a portion having a width of 1.5 mm at the center of the bottom surface) narrower than the width (2 mm) of the bottom surface of the portion (groove portion) between the opposite side surfaces of the adjacent circuit pattern is laser processed. A metal-ceramic circuit board was obtained in the same manner as in Example 1 except that the metal-ceramic circuit board was removed.

The metal circuit board 12 of the metal-ceramic circuit board obtained in this example has a thickness T of the metal circuit board 12 of 2.1 mm, a height h ₁ of the bent part 12a of 0.95 mm, and a bent part 12a. from the top to the upper surface of the metal circuit plate 12 of height _{h 2} is 1.15 mm, the distance between the bottom of the adjacent circuit patterns (insulation distance) _{D B} is 2.1 mm, the distance _{D T} between the top 3 mm, the depth _{d 1} of the gouged portion 12a is _{0.3mm, | D T -D B |} = 0.9, was T / D B = 1.00.

[Example 7]
The thickness of the portion substantially corresponding to the circuit pattern is 2.1 mm, the thickness of the portion between the side surfaces of the adjacent circuit patterns facing each other is 0.4 mm, and the distance between them (the adjacent circuit patterns facing each other) Uses a lower mold member in which a circuit metal plate forming portion, which is a recess having a shape and size approximately equal to a circuit metal plate having a width between the side surfaces (grooves) of 2 mm, is formed on the bottom surface. Then, only the portion of the etching resist 16 that covers a portion (a portion having a width of 1.5 mm at the center of the bottom surface) narrower than the width (2 mm) of the bottom surface of the portion (groove portion) between the opposite side surfaces of the adjacent circuit pattern is laser processed. A metal-ceramic circuit board was obtained in the same manner as in Example 2 except that the removal was carried out in the same manner as in Example 2.

The metal circuit board 12 of the metal-ceramic circuit board obtained in this example has a thickness T of the metal circuit board 12 of 2.1 mm, a height h ₁ of the bent part 12a of 0.65 mm, and a bent part 12a. the upper end of the to the upper surface of the metal circuit plate 12 height _{h 2} is 1.45mm, the distance between the bottom of the adjacent circuit patterns (insulation distance) _{D B} is 2.1 mm, the distance _{D T} between the top 2. The depth d ₁ of the bent portion 12a was 8 mm, 0.16 mm, | D _T −D _B | = 0.7, and T / D _B = 1.00.

10 Ceramic substrate 12 Metal plate for circuit (metal circuit plate)
12a Bending portion 14 Metal base plate 16 Etching resist 100 Lower mold member 100a Bottom surface portion 100b Side wall portion 100c Recessed portion 100d Circuit metal plate forming portion 100e Ceramic substrate housing portion 100f Metal base plate forming portion

Claims (9)

A metal plate having a shape similar to a circuit pattern and having a thickness other than a portion substantially corresponding to the circuit pattern thinner than a thickness of a portion substantially corresponding to the circuit pattern is bonded to the ceramic substrate, and the circuit of the metal plate after substantially coated with resist on the bottom of the entire surface of a portion between side surfaces facing each other over the entire surface of the adjacent circuit patterns of upper and side surfaces of the portions corresponding to the pattern, and the side parts fraction substantially corresponding to the circuit pattern of the metal plate At least a portion is removed opposing parts resist applied to the bottom surface of between sides of adjacent circuit patterns by etching the circuit pattern and an adjacent substantially corresponding parts of the side surface to the circuit pattern of the metal plate A method for producing a metal-ceramic circuit board, wherein at least a part of a bottom surface of a portion between side surfaces facing each other is removed. The metal plate and the ceramic substrate are joined by forming a metal plate by bringing a molten metal into contact with one surface of the ceramic substrate and then cooling and solidifying the metal plate. 2. A method for producing a metal-ceramic circuit board according to 1. The metal plate and the ceramic substrate are joined using a mold in which a ceramic substrate housing portion having a shape and size substantially equal to the ceramic substrate and a metal plate forming portion adjacent to the ceramic substrate housing portion are formed. Then, the ceramic substrate is accommodated in the ceramic substrate accommodating portion of the mold, and a molten metal is poured into the metal plate forming portion so as to be in contact with one surface of the ceramic substrate, and then cooled and solidified. The metal-ceramic circuit board manufacturing method according to claim 1, wherein the metal-ceramic circuit board is formed. The metal plate forming portion has a shape similar to the circuit pattern of the metal plate and having a depth other than a portion substantially corresponding to the circuit pattern shallower than a depth of a portion substantially corresponding to the circuit pattern. A method for producing a metal-ceramic circuit board according to claim 3. When the molten metal is brought into contact with one surface of the ceramic substrate, the molten metal is brought into contact with the other surface of the ceramic substrate, and is cooled and solidified to form a metal member to form the other surface of the ceramic substrate. The method for producing a metal-ceramic circuit board according to claim 2, wherein the metal-ceramic circuit board is bonded to the surface. 6. The method for producing a metal-ceramic circuit board according to claim 2, wherein the molten metal is a molten aluminum or aluminum alloy. The method for producing a metal-ceramic circuit board according to any one of claims 1 to 6, wherein the resist is removed by laser processing before the etching process. In removing at least a portion of the bottom surface portion between the side surfaces facing each other of the circuit pattern adjacent substantially corresponding parts of the side surface to the circuit pattern of the metal plate by the etching process, the circuit pattern of the metal plate The method for producing a metal-ceramic circuit board according to any one of claims 1 to 7, wherein a concave portion that is bent and bent is formed in a portion that is not covered with a resist in a corresponding portion. 9. The method for manufacturing a metal-ceramic circuit board according to claim 1, wherein a thickness of a portion substantially corresponding to the circuit pattern of the metal plate is 0.4 mm or more.

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