JP5151080B2 - Insulating substrate, method for manufacturing insulating substrate, power module substrate and power module - Google Patents

Description

  The present invention relates to an insulating substrate suitable for a power module used in a semiconductor device that controls a large current and a high voltage, a method for manufacturing the insulating substrate, a power module substrate, and a power module.

This type of power module is generally provided with a conductor pattern made of pure Al or Al alloy on one surface side of a ceramic substrate made of AlN, Al ₂ O ₃ , Si ₃ N ₄ , SiC or the like. An insulating substrate, a radiator disposed on the other surface side of the ceramic substrate, a heating element disposed on a surface of the conductor pattern opposite to the surface facing the ceramic substrate, and the heat dissipation A cooling sink disposed on a surface of the body opposite to the surface facing the ceramic substrate, and dissipating heat from the heating element to the outside via the heat radiating body and the cooling sink. It has become.

  The insulating substrate of the power module configured as described above is formed as follows. That is, it is formed by bonding a plate-like circuit layer formed of pure Al or Al alloy to the surface of a ceramic substrate by soldering or brazing, and then etching the circuit layer to form a conductor pattern. Has been. Here, the conductor pattern formed by the etching process gradually increases in width from the upper surface (heating element side) to the lower surface (ceramic substrate side).

By the way, in recent years, power modules are required to have higher currents, higher voltages, and further downsizing, that is, to reduce the width of conductors constituting a conductor pattern and to narrow the interval between the conductors.
First, in order to meet the former requirement, it is necessary to increase the conductive area of the conductor pattern. However, in order to increase the size of the conduction area, the external dimensions of the ceramic substrate cannot be increased due to the design restrictions of the device itself that incorporates the power module. This thickness cannot be increased, and this thickness must be increased. In this case, when the conductor pattern is formed by performing the etching process as described above, the width on the lower surface side of the conductor is increased by increasing the thickness, and therefore the latter required specification is made compact. There is a problem that it is difficult to satisfy both of the required specifications.
In addition, increasing the thickness of the conductor causes an increase in the number of man-hours for the etching process, resulting in an increase in manufacturing cost of the power module.

Here, although it is a technical field different from the technical field to which the present invention belongs, an invention that can solve a problem that approximates the above-described problem is disclosed in Patent Document 1 below. That is, a method for manufacturing an insulating substrate having a base insulating layer, an adhesive insulating layer, and a conductor pattern in this order, obtained by subjecting a surface of the adhesive insulating layer in a B-stage state to press punching or the like. After placing the conductor pattern members (conductors) arranged in an aligned state, the adhesive insulating layer and the conductor pattern member are joined by pressurizing them, and the conductor pattern is disposed on the surface of the adhesive insulating layer It is. In the insulating substrate formed in this way, the side surfaces of the conductors constituting the conductor pattern (surfaces rising from the surface of the bonding insulating layer) are in a substantially exposed state.
Japanese Patent Laid-Open No. 11-186679

  However, when the conductor pattern member (conductor) is formed by press punching as in the invention described in Patent Document 1, this cut surface is the rear side in the cutting direction, that is, the primary shear surface (about two-thirds of the thickness). ), The surface roughness is small, but the front side in the cutting direction, that is, the secondary shear surface (about one third of the thickness) has a large surface roughness. In this case, when an insulating substrate is formed by applying the invention described in Patent Document 1, a power module is formed using this insulating substrate, and this is used, the undulation of the secondary shear surface becomes a singular point. As a starting point, sparks are generated, and there are cases where proper use of the power module is hindered, such as energizing a conductor located next to this conductor.

  The present invention has been made in consideration of such circumstances, and can realize a large current and high voltage of the power module, and also suppress an increase in size of the insulating substrate even in such a configuration. It is another object of the present invention to provide an insulating substrate, a method for manufacturing the insulating substrate, a power module substrate, and a power module that can realize low-cost production.

In order to achieve the above object, the present invention proposes the following means.
The invention according to claim 1 is an insulating substrate in which a conductor pattern is disposed on the surface side of the ceramic substrate, and rises from the surface side of the ceramic substrate among the outer surfaces of the conductor constituting the conductor pattern. The surface is configured to rise substantially perpendicular to the direction along the surface of the ceramic substrate, the conductor pattern is joined to the surface of the ceramic substrate by a brazing material, and the rising surface of the conductor is at least A lower side of the rising direction in which the rising surface rises from the surface side of the ceramic substrate is covered with the brazing material, and the rising surface of the conductor has a rising direction in which the rising surface rises from the surface side of the ceramic substrate. The lower surface roughness is larger than the upper surface roughness .

According to the present invention, since the conductor constituting the conductor pattern has the rising surface, even in the configuration in which the conductor pattern is thickened to increase the current and voltage of the conductor pattern. It is suppressed that the width becomes wider by the increase in thickness. Therefore, it is possible to realize both thinning of the conductor pattern and high current and high voltage.
The conductor pattern is bonded to the surface side of the ceramic substrate with a brazing material, and at least the lower side of the conductor constituting the conductor pattern is covered with the brazing material. The bonding strength with the surface side can be improved. Further, even when the surface roughness of the lower side of the rising surface is increased, this surface is covered with the brazing material, so when using the power module having this insulating substrate, The occurrence of a situation that hinders the proper use of the power module, such as the occurrence of sparks with the undulations on the surface as a singular point and the occurrence of sparks from this portion as the starting point, can be suppressed.

  According to the present invention, the rising surface of the conductor has a lower surface roughness (the surface of the conductor facing the ceramic substrate, that is, the lower surface) on the lower side of the rising direction (the surface of the conductor facing the ceramic substrate). Since the surface roughness on the opposite side (ie, the upper surface side) of the conductor is larger than the surface roughness, the bonding strength of the brazing material on the lower side of this conductor is increased, and the bonding strength between the conductor pattern and the surface side of the ceramic substrate is further increased Be improved.

According to a second aspect of the present invention, in the insulating substrate according to the first aspect, the surface of the brazing material covering the rising surface has an arithmetic average roughness Ra of less than 5 μm or a maximum height Ry of less than 40 μm. Alternatively, the ten-point average roughness Rz is smaller than 30 μm.

  According to the present invention, since the surface roughness of the brazing material covering the rising surface is in the above range, it is possible to prevent foreign matter from adhering to the surface of the brazing material. The occurrence of poor appearance can be reduced, and the adjacent conductors can be prevented from being energized, that is, the breakdown voltage can be improved.

The invention according to claim 3 is a method of manufacturing an insulating substrate in which a conductor pattern is disposed on the surface of a ceramic substrate, and a plate material is cut by shearing in the thickness direction to form a conductor pattern member having a cut surface. A conductive pattern member forming step and a brazing material on the surface of the ceramic substrate such that the cut surface rises from the front side of the ceramic substrate from the front side to the rear side in the cutting direction. And a step of placing the ceramic substrate and the conductor pattern member with the brazing material by pressurizing the laminated body while being heated in the laminating direction. It is characterized by that.

  According to the present invention, in the conductor pattern member forming step, the conductor pattern member to be formed has a cut surface, the surface of the cut surface on the rear side in the cutting direction has a small surface roughness, and the front side has a large surface roughness. In the above-described placing step as the next step, the conductive pattern member is cut from the front side in the cutting direction having a large surface roughness to the rear side in the cutting direction having a small surface roughness. The laminate is placed on the surface of the ceramic substrate through a brazing material so as to rise from the surface side, and then the laminate is pressurized in the stacking direction and heated in the joining step as the next step. Thus, the conductor pattern member and the surface side of the ceramic substrate are joined by the brazing material.

  In this joining step, the brazing material is heated in a state where the front end in the cutting direction of the cut surface of the conductor pattern member and the brazing material are brought into close contact with each other to melt the brazing material, so that the brazing material located in the periphery of the front end of the conductive pattern member In addition, the brazing material in a molten state is agglomerated by surface tension on the front side in the cutting direction of the cutting surface having a large surface roughness, and further, the brazing material gradually moves the cutting surface toward the rear side in the cutting direction. Will rise. Therefore, an insulating substrate in which substantially the entire rising surface is covered with the brazing material can be obtained.

  In addition, the brazing material hardened at the front end of the cut surface of the conductor pattern member is the thickest among the brazing materials covering substantially the entire area of the cut surface, and the outer surface is a curved surface in a side view. Become a shape. Therefore, even when the power module having this insulating substrate is used under a temperature cycle, the stress concentration is reduced, and it is possible to suppress the occurrence of cracks or the like at the bonding interface between the conductor pattern and the surface side of the ceramic substrate. The life of the power module can be extended.

  Furthermore, in this manufacturing method, since the conductor pattern is not formed by the etching process, the thickness of the conductor pattern member is increased to increase the current and voltage of the power module, thereby increasing the number of etching processes. There will be no adverse effects such as incurring or increasing the width of the conductor constituting the conductor pattern. Therefore, it is possible to provide a power module with a large current and a high voltage in a compact and low cost.

According to a fourth aspect of the present invention, there is provided an insulating substrate in which a conductor pattern is disposed on one surface side of a ceramic substrate, a heat radiator disposed on the other surface side of the ceramic substrate, and the conductor pattern, A heating module disposed on a surface opposite to the surface facing the ceramic substrate, and the radiator is a power module substrate configured to dissipate heat from the heating element to the outside, The insulating substrate comprises the insulating substrate according to claim 1 or 2 .

The invention according to claim 5 is an insulating substrate in which a conductor pattern is disposed on one surface side of a ceramic substrate, a radiator disposed on the other surface side of the ceramic substrate, and the conductor pattern, A heating element disposed on a surface opposite to the surface facing the ceramic substrate; and a cooling sink portion disposed on a surface opposite to the surface facing the ceramic substrate of the radiator. 3. A power module configured to dissipate heat from a heating element to the outside through the heat radiating body and the cooling sink portion, wherein the insulating substrate comprises the insulating substrate according to claim 1 or 2. It is characterized by that.

  According to these inventions, it is possible to realize both thinning of the conductor pattern and high current and high voltage, and it is possible to improve the bonding strength between the conductor pattern and the surface side of the ceramic substrate. Furthermore, since the rising surface of the conductor is substantially entirely covered with the brazing material, when using the power module having this insulating substrate, the undulation of the surface of the rising surface becomes a singular point, and the spark starts from this portion. Generation | occurrence | production and the occurrence of the situation which impairs proper use of a power module, such as electrifying with the conductor located next to this conductor, can be suppressed.

  According to the insulating substrate, the power module substrate, and the power module according to the present invention, it is possible to realize both the thinning of the conductor pattern, the large current and the high voltage, and the conductor pattern and the surface side of the ceramic substrate. The joint strength can be improved. Furthermore, even when burrs are generated on the rising surface of the conductor, it is possible to suppress the occurrence of a situation that hinders proper use of the power module.

  Further, according to the method for manufacturing an insulating substrate according to the present invention, it is possible to form an insulating substrate in which the rising surfaces of the conductors constituting the conductor pattern are substantially entirely covered with the brazing material. Furthermore, even when a power module having this insulating substrate is used under a temperature cycle, an insulating substrate that can reduce stress concentration and suppress the occurrence of cracks or the like at the bonding interface between the conductor pattern and the surface of the ceramic substrate is provided. Can be formed. Moreover, it becomes possible to provide such a power module at low cost.

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an overall view showing a power module to which an insulating substrate according to an embodiment of the present invention is applied.
The power module 40 includes a power module substrate 11 and a cooling sink 30 as shown in FIG.

The power module substrate 11 is provided with a conductor pattern 13 on one surface (hereinafter simply referred to as “upper surface”) of a ceramic substrate 12 formed of, for example, AlN, Al ₂ O ₃ , Si ₃ N ₄ , SiC, or the like. Insulating substrate 10, heat sink 14 disposed on the other surface (hereinafter simply referred to as “lower surface”) side of ceramic substrate 12, and conductor pattern 13 on the side opposite to the surface facing ceramic substrate 12. And a semiconductor chip (heating element) 15 disposed on the surface (hereinafter simply referred to as “upper surface”).
The cooling sink 30 is disposed in close contact with the surface (hereinafter simply referred to as “lower surface”) of the radiator 14 opposite to the surface facing the ceramic substrate 12 (hereinafter simply referred to as “upper surface”). Has been.

  In the present embodiment, a metal layer 16 is disposed between the ceramic substrate 12 and the radiator 14 on the lower surface side of the ceramic substrate 12, and the insulating substrate 10 includes the ceramic substrate 12, the conductor pattern 13, and the metal layer 16. It is the composition provided with.

The conductor pattern 13 and the metal layer 16 are made of pure Al or Al alloy. The conductor pattern 13 and the metal layer 16 are individually joined to the upper and lower surfaces of the ceramic substrate 12 by an Al—Si or Al—Ge brazing material 21.
The semiconductor chip 15 is joined to the upper surface of the conductor pattern 13 by the solder 22, and the lower surface of the metal layer 16 (surface facing the heat radiating body 14) is also soldered to the upper surface of the heat radiating body 14 by brazing or diffusion bonding. It is joined.

As described above, the power module 40 is configured, and the heat from the semiconductor chip 15 can be dissipated to the outside through the radiator 14 and the cooling sink portion 30.
Here, a circulation hole 32 connected to a refrigerant circulation means (not shown) for supplying and recovering a refrigerant 31 such as a coolant or cooling air is formed inside the cooling sink portion 30. The supplied refrigerant 31 recovers the heat conducted from the semiconductor chip 15 to the heat radiating body 14, the refrigerant circulating means recovers the refrigerant 31 that has recovered the heat, and supplies a new refrigerant 31. By repeating, the heat from the semiconductor chip 15 is dissipated from the power module 40.

  Here, the thickness of the ceramic substrate 12 is 0.25 mm to 3.0 mm, the thickness of the conductor pattern 13 is 0.1 mm to 2.0 mm, and the thickness of the metal layer 16 is 0.1 mm or more. The thickness of the brazing material 21 that joins the conductor pattern 13 and the metal layer 16 to the upper and lower surfaces of the ceramic substrate 12 is set to 0.005 mm or more and 0.1 mm or less, respectively.

In this embodiment, the conductor pattern 13 includes two plate-like conductors 17, and these conductors 17 are joined by a brazing material 21 in a state of being aligned on the upper surface side of the ceramic substrate 12. The interval between the conductors 17 is set to 0.1 mm or more. As shown in FIG. 2, among the outer surfaces of these conductors 17, the rising surface 17 a rising from the upper surface side of the ceramic substrate 12 rises substantially perpendicular to the direction along the upper surface of the ceramic substrate 12. The entire surface of the rising surface 17 a is covered with the brazing material 21.
Here, as shown in FIG. 3, the surface of the brazing material 21 covering the rising surface 17a has an arithmetic average roughness Ra of less than 5 μm, a maximum height Ry of less than 40 μm, and a ten-point average roughness Rz of 30 μm. Have been smaller. FIG. 3 shows the results of measuring Ra, Ry, and Rz at six locations among the plurality of rising surfaces 17a covered with the brazing material 21. FIG. Ra, Ry, and Rz were measured using Mitutoyo Surf Test 501 as a measuring instrument and Mitutoyo Corporation 178-382 (for soft materials) as a measuring element. Among these, the measurement conditions for Ra were set to 80 μm, the cut-off value was 0.8 mm, the number of sections was 5, and conformed to JIS B0651. The measurement conditions for Ry and Rz were in accordance with the DIN standard.

  As will be described later, the conductor 17 is formed by cutting a plate material formed of pure Al or an Al alloy in the thickness direction, and the cut surface obtained at this time is a rising surface 17a. The rising surface 17a is configured to rise from the upper surface side of the ceramic substrate 12 from the front to the rear in the cutting direction when the conductor 17 is formed by cutting.

  Here, in the rising surface 17a, the surface roughness of the cutting direction front side 17b is larger than the surface roughness of the cutting direction rear side 17c during cutting. The cutting direction front side 17b in the rising surface 17a is a region from the front end in the cutting direction of the rising surface 17a to the rear side 17c to about one third of the total thickness of the conductor 17, so-called secondary. A shearing surface is referred to, and the cutting direction rear 17c is a so-called primary shearing surface from the cutting direction rear end of the cutting direction front 17b to the rear end of the rising surface 17a in the cutting direction. In addition, the surface roughness of the cutting direction front 17b is Rz 30 μm or more, and the surface roughness of the cutting direction rear 17c is Rz 30 μm or less.

Therefore, the rising surface 17a of the conductor 17 is a surface on the lower side 17b (the surface side of the conductor 17 facing the ceramic substrate 12, that is, the lower surface side) in which the rising surface 17a rises from the upper surface side of the ceramic substrate 12. The roughness is larger than the surface roughness of the upper side 17c (the upper surface side of the conductor 17).
The brazing material 21 located at the lower end portion of the lower side 17b of the rising surface 17a is the thickest among the brazing materials 21 covering substantially the entire area of the rising surface 17a. As shown in FIG. 2, it has a concave curved surface shape.

Next, a method for manufacturing the insulating substrate 10 of the power module 40 configured as described above will be described.
First, a plate material made of pure Al or an Al alloy is cut by shearing in the thickness direction so as to have a predetermined size, thereby forming a conductor 17 (conductor pattern member) (conductor pattern member forming step). The cut surface obtained at this time becomes the rising surface 17a.
Next, the conductor 17 is arranged in a desired alignment via the brazing material 21 on the upper surface of the ceramic substrate 12 so that the rising surface 17a rises from the upper surface side of the ceramic substrate 12 from the front 17b to the rear 17c in the cutting direction. Place in state. On the other hand, the metal layer 16 is disposed on the lower surface of the ceramic substrate 12 via the brazing material 21, and the metal layer 16, the brazing material 21, the ceramic substrate 12, the brazing material 21, and the aligned conductors are arranged as described above. 17 is a stacked body placed in this order (placement step).
The laminated body is heated while being pressed in the laminating direction, and the brazing material 21 is melted and cured in a state where the front end of the front side 17b in the cutting direction on the rising surface 17a of the conductor 17 and the brazing material 21 are in close contact with each other. By doing so, the upper surface side of the ceramic substrate 12 and the conductor 17 are bonded, and the lower surface side of the ceramic substrate 12 and the metal layer 16 are bonded (bonding step), thereby forming the insulating substrate 12.
Thereafter, an etching process may be performed as necessary to clean the outer surface of the insulating substrate 10.

Here, specific examples in the joining step will be described.
First, regarding the material, the metal layer 16 was made of pure Al, the brazing material 21 was made of Al—Si, the ceramic substrate 12 was made of AlN, and the conductor 17 was made of pure Al. Next, regarding the thickness, the metal layer 16 was about 0.6 mm, the brazing material 21 was about 0.01 mm, the ceramic substrate 12 was about 0.635 mm, and the conductor 17 was about 0.6 mm. The interval between the conductors 17 was set to about 1.0 mm.
And in the state which put the said laminated body in the vacuum of 630 degreeC, 0.3 Mpa was pressurized in the lamination direction for 1 hour.

  As described above, according to the insulating substrate, the power module substrate, and the power module according to the present embodiment, the conductor 17 constituting the conductor pattern 13 includes the rising surface 17a. Therefore, the thickness of the conductor 17 is increased. Thus, even in the configuration in which the conductor pattern 13 has a high current and a high voltage, the width of the conductor 17 is suppressed from being increased by the increase in thickness. Therefore, it is possible to realize both the thinning of the conductor pattern 13 and the large current and high voltage.

  In addition, the conductor pattern 17 is joined to the upper surface side of the ceramic substrate 12 by the brazing material 21, and the rising surface 17 a of the conductor 17 is almost entirely covered by the brazing material 21. It is possible to improve the bonding strength with the upper surface side. Further, even when the surface roughness of the rising surface 17a of the conductor 17 is increased, this surface is covered with the brazing material 21, so that when the power module 40 having the insulating substrate 12 is used, the rising surface is used. Suppressing the occurrence of a situation that hinders the proper use of the power module 40, such as the occurrence of a spark from the undulation of the surface 17a and the occurrence of a spark from this portion as a starting point, and the energization of the conductor 17 located next to the conductor 17 Can do.

Further, since the rising surface 17a of the conductor 17 has a surface roughness of the lower side 17b in the rising direction larger than the surface roughness of the upper side 17c, the bonding force of the brazing material 21 on the lower side 17b of the conductor 17 is increased. Further, the bonding strength between the conductor pattern 13 and the upper surface side of the ceramic substrate 12 can be further improved.
Furthermore, since the surface roughness of the brazing material 21 covering the rising surface 17a is within the above range, it is possible to prevent foreign matter from adhering to the surface of the brazing material 21, and this insulating substrate 10 The occurrence of the appearance defect can be reduced, and the adjacent conductors 17 can be prevented from being energized, that is, the breakdown voltage can be improved.

  In the joining step, the brazing material 21 is heated in a state where the front end of the front 17b in the cutting direction on the rising surface 17a of the conductor 17 and the brazing material 21 are brought into close contact with each other, so that the periphery of the front end of the conductor 17 is The brazing material 21 in a molten state including the brazing material 21 positioned in the portion is aggregated by surface tension in the cutting direction front 17b having a large surface roughness, and the brazing material 21 is cut in the cutting direction of the rising surface 17a. Ascending gradually toward the rear 17c. Therefore, it is possible to form the insulating substrate 10 in which substantially the entire area of the rising surface 17a is covered with the brazing material 21.

  Further, as described above, since the molten brazing material 21 reaches almost the entire surface of the rising surface 17a of the conductor 17, the brazing material 21 cured at the front end portion of the front 17b in the cutting direction is substantially the same as the rising surface 17a. Of the brazing material 21 covering the entire region, the thickness becomes the largest, and the outer surface has a concave curved surface shape (a fillet is formed) in a side view. Therefore, even when the power module 40 having the insulating substrate 10 is used under a temperature cycle, it is possible to suppress the occurrence of cracks or the like due to stress concentration at the bonding interface between the conductor pattern 13 and the upper surface side of the ceramic substrate 12. Thus, the life of the power module 40 can be extended.

  Furthermore, in the method for manufacturing the insulating substrate 10 according to the present embodiment, since the conductor pattern 13 is not formed by the etching process, the thickness of the conductor 17 is increased in order to increase the current and voltage of the power module 40. As a result, there is no adverse effect such as an increase in the number of man-hours for the etching process and the accompanying increase in the width of the conductor constituting the conductor pattern. Therefore, it becomes possible to provide the power module 40 with high current and high voltage in a compact and low-cost manner.

The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.
For example, in the above-described embodiment, the rising surface 17a is the cut surface, but it is not necessarily limited to the cut surface.
Further, by setting the rising surface 17a as a cut surface, all the effects of the above-described embodiment are provided. In this case, it is not necessary that all the rising surfaces 17a be cut surfaces, and at least one surface is a cut surface. If it exists, it will have the same effect as the said embodiment.
Further, in the joining step, the brazing filler metal 21 in the molten state is raised on the rising surface 17a from the lower surface side of the conductor 17 toward the upper surface side. At this time, the brazing material 21 is made to reach the upper surface of the conductor 17. Also good.
Moreover, although the structure which the substantially whole surface of the rising surface 17a was coat | covered with the brazing material 21 was shown, at least the cutting direction front side 17b should just be coat | covered among the rising surfaces 17a.
Further, in the above embodiment, the arithmetic average roughness Ra is smaller than 5 μm, the maximum height Ry is smaller than 40 μm, and the ten-point average roughness Rz is smaller than 30 μm. However, Ra, Ry, and Rz It is sufficient that at least one of the ranges is within the above range.

  Insulating substrate that can realize high current and high voltage of the power module, can suppress the increase in size of the insulating substrate even in such a configuration, and can realize low-cost production. And an insulating substrate manufacturing method, a power module substrate, and a power module.

1 is an overall view showing a power module to which an insulating substrate according to an embodiment of the present invention is applied. It is the A section enlarged view shown in FIG. It is a figure which shows the result of having measured Ra, Ry, and Rz of the brazing material which coat | covers the rising surface shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Insulation board | substrate 11 Power module board | substrate 12 Ceramics board | substrate 13 Conductor pattern 14 Radiator 15 Heating element 17 Conductor (conductor pattern member)
17a Rising surface 17b Lower side in the rising direction, front in the cutting direction 17c Upper side in the rising direction, rearward in the cutting direction 21 Brazing material 30 Cooling sink part 40 Power module

Claims (5)

An insulating substrate having a conductive pattern disposed on the surface side of a ceramic substrate,
Of the outer surface of the conductor constituting the conductor pattern, the rising surface rising from the surface side of the ceramic substrate is configured to rise substantially perpendicular to the direction along the surface of the ceramic substrate,
The conductor pattern is bonded to the surface of the ceramic substrate by a brazing material,
The rising surface of the conductor is at least covered with the brazing material on the lower side of the rising direction in which the rising surface rises from the surface side of the ceramic substrate ,
The insulating substrate, wherein the rising surface of the conductor has a lower surface roughness in a rising direction in which the rising surface rises from the surface side of the ceramic substrate than the upper surface roughness . The insulating substrate according to claim 1 ,
The surface of the brazing material covering the rising surface has an arithmetic average roughness Ra of less than 5 μm, a maximum height Ry of less than 40 μm, or a ten-point average roughness Rz of less than 30 μm. Insulating substrate. A method of manufacturing an insulating substrate in which a conductor pattern is disposed on the surface of a ceramic substrate,
A conductor pattern member forming step of cutting a plate material by shearing in the thickness direction to form a conductor pattern member having a cut surface;
The conductor pattern member is placed on the surface of the ceramic substrate via a brazing material so that the cut surface rises from the front side of the ceramic substrate from the front side to the rear side in the cutting direction. A loading process, and
A method of manufacturing an insulating substrate, comprising: a step of pressing the laminated body in a state of being heated in a laminating direction and joining the ceramic substrate and the conductor pattern member with the brazing material. An insulating substrate having a conductor pattern disposed on one surface side of the ceramic substrate, a radiator disposed on the other surface side of the ceramic substrate, and a surface of the conductor pattern opposite to the surface facing the ceramic substrate A heating module disposed on the surface of the side, wherein the radiator is a power module substrate configured to dissipate heat from the heating element to the outside,
3. The power module substrate according to claim 1 , wherein the insulating substrate comprises the insulating substrate according to claim 1 . An insulating substrate having a conductor pattern disposed on one surface side of the ceramic substrate, a radiator disposed on the other surface side of the ceramic substrate, and a surface of the conductor pattern opposite to the surface facing the ceramic substrate And a heat sink disposed on a surface of the heat radiating member opposite to the surface facing the ceramic substrate, and dissipates heat from the heat radiating member. A power module configured to dissipate to the outside through the body and the cooling sink part,
The power module comprising the insulating substrate according to claim 1 or 2 .

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