JP2002329938A - Ceramic circuit board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a highly reliable ceramic circuit board having strength enough to avoid deformation and high cooling performance. SOLUTION: The ceramic circuit board 1 having a circuit 3 for mounting a semiconductor component 4 has a hollow 2 for forming a refrigerant flow passage in a lower part of the circuit 3 for mounting the component 4. This meets the condition that the distance t from the circuit 3 to the hollow 1 in the substrate thickness direction meets 0.5 mm<=t<=5 mm, and the distance t and the width Y of the hollow 2 relate so that Y<=20t.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ceramic circuit board for mounting semiconductor components, and more particularly, to a ceramic circuit board such as a power semiconductor module used for an electric vehicle drive device, an inverter device and the like. .

[0002]

2. Description of the Related Art In a power semiconductor module, a semiconductor component for power supply such as an IGBT element and a diode are bonded and mounted on the surface of an insulating substrate by soldering or the like, and the insulating substrate is bonded to a heat sink by soldering or soldering. Further, the heat sink has a structure in which the heat sink is joined to a cooling device such as a radiating fin or a water cooling jacket by soldering, soldering, or screwing, so that the heat generated by the semiconductor component can be cooled by the cooling device.

In recent years, power semiconductor modules have been used for high voltage,
There is a demand for characteristics of switching at high speed under a large current. Since a large amount of heat is generated by high-speed switching under a large current, the power semiconductor module needs to have improved heat dissipation and cooling performance. Further, with the practical use of hybrid cars and electric vehicles, power semiconductor modules are required to be smaller, lighter, lower in price and more reliable.

To meet these requirements, conventionally, a plurality of metal plates processed into a predetermined shape are joined by sandwiching them between ceramic plates on which circuits are formed, and a flow path formed between the metal plates is formed. A ceramic circuit board having a heat pipe structure in which a refrigerant is sealed in a substrate has been proposed (JP-A-8-13948).
No. 0). In addition, a circuit board having a wick-structured heat pipe with an improved refrigerant recirculation capability has also been proposed (Japanese Patent Publication No. 62-39358).

[0005]

However, Japanese Patent Application Laid-Open No. Hei 8-1
The heat-dissipating ceramic circuit board having the heat pipe structure disclosed in Japanese Patent No. 39480 requires a step of processing a metal plate into a predetermined shape and a step of joining the metal plate and the ceramic circuit board. However, there has been a problem that the production cost is increased due to an increase in complexity and complexity.

[0006] Usually, a circuit formed on a ceramic circuit board is formed by printing a paste of W, Mo, Au, Cu, or the like on a board, or a metal plate (for a circuit) such as a Cu plate or an Al plate. By using an active metal brazing such as AgCuTi brazing. In forming the circuit, a high-temperature heat treatment of about 900 ° C. is performed.

On the other hand, in the ceramic circuit board disclosed in Japanese Patent Application Laid-Open No. 8-139480, when Al is used for a metal plate (for forming a coolant flow path), the metal plate and the ceramic circuit board are bonded together. Al brazing at a heat treatment temperature of about 600 ° C. is used. Therefore, the circuit formation requiring heat treatment at a temperature equal to or higher than the melting point of Al brazing (about 900 ° C.) must be performed before joining the metal plate (for forming the coolant passage) and the ceramic circuit board. As a result, the formed circuit is subjected to thermal shock (about 600 ° C.) at the time of joining the metal plate (for forming the coolant flow path) and the ceramic circuit board. There is a possibility that the reliability of the joint may be reduced.

Further, when the thickness of the metal plate (for forming the refrigerant flow path), which is the thickness of the refrigerant flow path, is 3 mm or more, the junction between the ceramic circuit board and the metal plate tends to peel off due to a temperature change. The thickness of the metal plate is limited to 3 mm or less. As a result, the flow rate of the refrigerant is restricted, and it may be difficult to improve the cooling performance accompanying an increase in the power of the module.

In an IC substrate having a wick structure heat pipe disclosed in Japanese Patent Publication No. 62-39358,
After filling the wick material, the substrate on which the window frame-shaped spacer and the electronic component are to be mounted is bonded with a Si-based resin adhesive. For this reason, there has been a problem that the heat radiation of the entire substrate is poor and the reliability of the joint portion of the substrate is low.

[0010] To solve these problems, the present inventors have considered providing a cavity serving as a coolant flow path in a ceramic circuit board. However, when such a ceramic circuit board is formed, the cavity is provided. There has been a problem in that the upper substrate (ceramic layer) is deformed to hinder the formation of a circuit, or the cooling performance of the refrigerant is reduced, thereby deteriorating the reliability of the circuit.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a highly reliable ceramic circuit board having strength that does not cause deformation and high cooling performance.

[0012]

Means for Solving the Problems The inventors of the present invention have made intensive studies to solve the above-mentioned problems, and as a result, have found that a ceramic circuit board having a circuit on which a semiconductor component is mounted has a lower portion of the circuit on which the semiconductor component is mounted. And a gap t serving as a coolant flow path is formed in the substrate, and a distance t in the substrate thickness direction from the circuit to the gap satisfies a condition of 0.5 mm ≦ t ≦ 5 mm, and the distance t and the width Y of the gap are satisfied. When Y and Y have a relationship of Y ≦ 20t, they have found a new fact that they have sufficient strength to prevent deformation and that high cooling performance can be obtained, and have completed the present invention.

Further, in the present invention, it is preferable that the width Y of the gap and the width L of the semiconductor component have a relationship of Y ≧ 0.8 L, thereby ensuring that the semiconductor component which has generated heat does not malfunction. Can be cooled.

In the present invention, a coolant is circulated through the gap, and the semiconductor component is cooled by a liquid cooling method or a boiling cooling method.

Specifically, the ceramic circuit board of the present invention is formed by extruding a ceramic material into a mold to obtain a molded body having a void portion penetrating therein, and then firing this molded body. A ceramic circuit board according to claim 1, wherein said void after firing is formed so as to satisfy said conditions of t and Y.

Further, another ceramic circuit board of the present invention is a ceramic circuit board formed by firing a laminate in which a plurality of ceramic sheets are laminated, wherein a void portion is formed inside the laminate. And the gap after firing is formed so as to satisfy the conditions of t and Y described above.

As described above, these ceramic circuit boards can be manufactured in a small number of steps because a predetermined gap portion (refrigerant flow path) is formed in the ceramic circuit board at the same time when the ceramic circuit board is manufactured. It is inexpensive and compact, and it is not necessary to form a new cavity after the circuit is formed, and no thermal shock is applied to the circuit, so that high reliability can be obtained.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings. FIG. 1 schematically shows a ceramic circuit board 1 according to the present invention. As shown in FIG. 1, the ceramic circuit board 1 includes a circuit 3 on which a semiconductor component 4 is mounted.
Is formed at the lower portion of the space.

The gap 2 is separated from the circuit 3 by the gap 2
The distance t in the substrate thickness direction up to 0.5 mm ≦ t ≦ 5 mm
Is satisfied, and the distance t and the width Y of the gap 2 are Y
It has a shape that satisfies the relationship of ≦ 20t.

When the distance t is less than 0.5 mm, the strength of the ceramic circuit board 1 is reduced and the ceramic layer under the circuit 3 is deformed, so that the circuit 3 (Cu Plate or a metal plate such as an Al plate) or a crack may occur in the ceramic circuit board 1.

If the distance t exceeds 5 mm, the thermal resistance increases and the heat of the semiconductor component 4 cannot be sufficiently absorbed by the refrigerant in the gap 2, which may cause the semiconductor component 4 to malfunction. Therefore, the distance t is 0.5 mm ≦ t ≦ 5 m
It is preferable to satisfy the condition of m, especially 0.7 mm ≦ t ≦ 3 mm.

If the width Y of the gap 2 exceeds 20 times the distance t, the ceramic layer under the circuit 3 may be deformed by its own weight or an external force. There is a risk that the formation will be hindered. Therefore, it is preferable that the width Y and the distance t have a relationship of Y ≦ 20t.

Further, the ceramic circuit board according to the present invention comprises:
When the width Y of the gap 2 and the width L of the semiconductor component 4 are Y ≧
It is preferable to satisfy 0.8 L. If the width Y is smaller than 0.8 times the width L, the semiconductor component 4 cannot be sufficiently cooled, and the malfunction of the semiconductor component 4 may be caused. More preferably, Y ≧ 2t + L
It is good to satisfy the relationship. By taking the distance t and the width L of the semiconductor component 4 into consideration as described above, the semiconductor component 4 can be more reliably cooled. From the above, Y,
t and L are 0.8L ≦ Y ≦ 20t, more preferably 2
It is preferable to satisfy the relationship of t + L ≦ Y ≦ 20t.

The thickness T of the gap shown in FIG. 1 is not particularly limited, but is preferably about 0.1 to 1 in order to achieve both miniaturization of the ceramic circuit board and securing of the flow rate of the refrigerant.
It may be 0 mm, more preferably about 1-8 mm.

As the ceramic circuit board of the present invention, aluminum oxide (Al ₂ O ₃ ), zirconium oxide (Zr
O ₂ ), silicon nitride (Si ₃ N ₄ ), aluminum nitride (AlN) and silicon carbide (SiC). Of these, aluminum nitride (AlN) and silicon carbide (SiC) are preferred if high thermal conductivity is required. Silicon nitride (Si ₃ N ₄ ) has excellent thermal shock resistance, and aluminum oxide (Al ₂ O ₃ ) is preferable in terms of cost.

The material and forming method of the circuit 3 formed on the ceramic circuit board 1 are determined according to the allowable current. If the allowable current is small, a method of forming a circuit pattern of W or Mo paste on the ceramic circuit board 1 by a screen printing method and firing it at the same time as the ceramic circuit board 1 or after firing and forming the ceramic circuit board 1 Then, a circuit pattern of Cu or Ag paste is formed on the ceramic circuit board 1 by a screen printing method and fired in an inert atmosphere at about 900 ° C. (in the case of Cu paste) or an oxidizing atmosphere at about 900 ° C. (in the case of Ag paste). The way you are used.

If the allowable current is large, a metal plate such as a Cu plate or an Al plate is processed into a predetermined circuit pattern, and the metal plate is placed on the ceramic circuit board 1 with an active solder having an AgCuTi composition, an AlSi composition, or the like. Join. At this time, the heat treatment is performed in a vacuum atmosphere of about 900 ° C. for a Cu plate and in a vacuum atmosphere of about 600 ° C. for an Al plate. Among these circuits, a Cu plate is preferable in terms of electric characteristics and thermal characteristics, and an Al plate is preferable in terms of bonding reliability with a ceramic circuit board.

As described above, the semiconductor component 4 may generate heat when energized, and generate a large amount of heat when switching at high speed under a high voltage and a large current. The semiconductor component 4 is cooled by circulating a coolant to prevent malfunction.

The coolant is circulated through the gap 2 to allow the semiconductor component 4
When cooling is used, it is preferable to use a liquid cooling system or a boiling cooling system. In the liquid cooling method, a liquid refrigerant having a temperature lower than that of the semiconductor component 4 that generates heat is circulated inside the gap portion 2 and the semiconductor component 4 is cooled by circulating the liquid refrigerant. The boiling cooling method evaporates the refrigerant in the process of flowing the refrigerant through the gap 2, and cools the semiconductor component 4 by latent heat of evaporation at that time.

FIG. 2 shows a ceramic circuit board 11 according to an embodiment of the present invention. As shown in FIG. 2, the ceramic circuit board 11 is a molded body having a cavity 12 penetrating therein, and is disposed immediately below a semiconductor component such as a power device. Note that, in the case of this embodiment, the width Y of the gap 12 is in the range illustrated in FIG.

FIG. 3 shows a ceramic circuit board 21 according to another embodiment of the present invention. As shown in FIG. 3, the ceramic circuit board 21 is a molded body having a U-shaped void portion 22 therein, and is disposed immediately below a semiconductor component such as a power device. In the case of this embodiment, the width Y of the gap 22 is in the range shown in FIG.

When a liquid cooling system is used as the cooling system, a liquid refrigerant is fed from one of the openings 12a and 22a of the gaps 12 and 22 to absorb the heat of the semiconductor component 4 inside the gaps 12 and 22. The liquid refrigerant is discharged from the other openings 12b and 22b. This liquid refrigerant circulates between a cooler (not shown) and the gaps 12 and 22 to cool the semiconductor component 4.

When a boiling cooling system is used as a cooling system, cooling fins are connected to the opening surfaces of the gaps 12 and 22, condensed liquid flows in from one of the openings 12a and 22a, and the other openings 12b and 22b. The steam is discharged from. At this time, when the refrigerant evaporates inside the gaps 12 and 22, the semiconductor component 4 is cooled by the latent heat of evaporation.

Hereinafter, a method for manufacturing the ceramic circuit board of the above embodiment will be described. <Manufacture of a ceramic circuit board having a void portion penetrating inside> In the case of having a void portion penetrating inside as shown in FIG. 1
2 is obtained, and then the formed body is fired to form the ceramic circuit board 11. Also,
The obtained ceramic circuit board 11 is formed so that the voids 12 after firing satisfy the conditions of t and Y described above.

The ceramic material (for example, aluminum oxide powder or the like) includes sintering aids such as SiO ₂ , CaO, and MgO, at least one organic binder selected from the group consisting of acrylic, cellulose, and polyethylene, and dibutyl. A plasticizer such as phthalate, a solvent such as stearic acid, and the like are added, and then these are kneaded with a vacuum kneader or the like to produce an air-free clay body.

The above clay body is filled in an extruder, extruded into a predetermined mold and formed into a desired shape. At this time, by changing the shape of the mold, the shape of the ceramic circuit board 11 such as the gap shape and the thickness of the ceramic layer immediately below the circuit can be freely adjusted.

Next, the extruded product is dried and then heated to about 400 ° C. to remove organic substances. If the ceramic material is aluminum oxide (Al ₂ O ₃ ), then at about 1600 ° C.
Firing in an oxidizing atmosphere. Also, the ceramic circuit board 1
In the case of simultaneously firing the circuit 1 and the circuit 3, a circuit pattern of W or Mo paste was formed on the ceramic circuit board 11 by a screen printing method, and the circuit 3 was formed by firing in a reducing atmosphere at about 1600 ° C. The ceramic circuit board 11 is obtained.

When the ceramic material is silicon nitride (Si)_ThreeN_Four)
In the case of aluminum oxide (Al _TwoO_Three)
And Y_TwoO_ThreeSintering aids such as rare earth oxides, organic binders
After adding a solvent, etc., and obtaining a molded body by extrusion molding,
Firing in a nitrogen atmosphere of about 1700-1900 ° C
Thus, a ceramic circuit board 11 is obtained.

On the obtained ceramic circuit board 11, a metal plate having a thickness of about 0.05 to 0.4 mm is placed on a circuit 3 (FIG. 1).
To join. As the metal plate, the above-mentioned Cu plate, Al
A plate or the like is used, and the above-mentioned active solder or the like is used for joining the ceramic circuit board 11 and the metal plate. On the circuit 3 thus obtained, the semiconductor component 4 is mounted by soldering or the like.

As described above, pipes are respectively connected to both ends of the opening of the gap portion 12 to cool the semiconductor component 4 which has generated heat by circulating a coolant. As the refrigerant, a fluorine-based cooling liquid (for example, Fluorinert manufactured by Sumitomo 3M Co., Ltd.) or the like can be used.

<Manufacture of a ceramic circuit board having a U-shaped or the like void therein> In the case where a U-shaped or the like void 22 is provided inside as shown in FIG. 3, the above-described ceramic material is formed into a ceramic sheet. The ceramic circuit board 21 is obtained by laminating and firing those appropriately punched. Further, the obtained ceramic circuit board 21 is formed such that the void portion 22 after firing satisfies the conditions of t and Y described above.

[0042] The same sintering aid, organic binder, plasticizer, solvent and the like as described above are added to the ceramic material. This ceramic material is formed into a ceramic sheet by a doctor blade method.

In the punching process, each of the ceramic sheets is processed so as to have a predetermined shape of the void portion 22, and the obtained ceramic sheets are laminated under pressure. At this time, by changing the shape of the punched ceramic sheet and the number of laminated sheets, the ceramic circuit board 21 can be formed in a shape such as an air gap or the thickness of the ceramic layer immediately below the circuit.
Can be freely adjusted. The obtained laminate is fired and the circuit is joined as in the case of FIG.
A semiconductor component is mounted.

The ceramic circuit board obtained as described above has a structure in which a cavity 22 is formed inside the substrate (a structure in which the ceramic layer on which the circuit is formed and the coolant flow path have no joints). , Because it can be manufactured with a small number of processes,
It is inexpensive and compact, and also has high strength.

The number of voids formed in the ceramic circuit board is not particularly limited, and may be appropriately determined according to the number and size of circuits and semiconductor components formed on the board.

[0046]

EXAMPLES Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited to the following examples.

Example 1 <Formation of ceramic circuit board having voids penetrating inside> Aluminum oxide (Al ₂
O ₃ ) 100 parts by weight of sintering aids SiO ₂ and Ca
8 parts by weight of O and MgO, 8 parts by weight of a cellulosic organic binder, and 0.5 parts of dibutyl phthalate as a plasticizer
10 parts by weight of water as a solvent and 10 parts by weight of a solvent were added, and this ceramic material was kneaded with a vacuum kneader to prepare a clay body containing no air. Next, the clay body is filled in an extruder, the clay body is extruded into a mold, and the thickness after firing is 5 m.
An extruded product having a void space of m was obtained. After drying the extruded body, the organic matter is removed by heating in an atmosphere of about 600 ° C. for 3 hours, and further fired in an oxidizing atmosphere of about 1600 ° C. to form a void penetrating into the inside as shown in FIG. Ceramic circuit board (Sample Nos. 1 to 9)
Was prepared. Table 1 shows the distance t from the circuit of each sample to the gap and the width Y of the gap.

Example 2 <Formation of ceramic circuit board having voids penetrating inside> Aluminum oxide (Al ₂
Instead of O ₃ ), silicon nitride (Si ₃ N ₄ ) was used, and with respect to 100 parts by weight, 8 parts by weight of a sintering aid Y ₂ O ₃ was used.
10 parts by weight of a cellulosic organic binder, 0.5 parts by weight of dibutyl phthalate as a plasticizer, and 15 parts by weight of water as a solvent are added, and the ceramic material is kneaded with a vacuum kneader to obtain an air-free clay body. Was prepared. Then, an extruded product was obtained in the same manner as in Example 1. After drying this extruded product, the organic matter was removed by heating it in an atmosphere of about 600 ° C. for 3 hours, and further fired in a nitrogen atmosphere of about 1800 ° C. to obtain a ceramic circuit board (sample No. .10 to 18). Table 1 shows the distance t and the width Y of each of the obtained samples.

Example 3 <Formation of Ceramic Circuit Board Having U-shaped Void Inside> Aluminum oxide (Al) as a ceramic material
₂ O ₃ ) 100 parts by weight of sintering aids SiO ₂ and Ca
8 parts by weight of O and MgO, 1 part of acrylic organic binder
0 parts by weight, 1 part by weight of dibutyl phthalate as a plasticizer, and 30 parts by weight of toluene as a solvent were added, and a thickness of about 0.
A plurality of 3 mm ceramic sheets were produced. This ceramic sheet is stamped into a U-shape as shown in FIG.
Pressure lamination was performed together with the non-punched ceramic sheet. After drying the obtained laminate, the temperature is about 600 ° C.
The organic material was removed by heating for 3 hours in an atmosphere of, and further baked in an oxidizing atmosphere at about 1600 ° C. to obtain a ceramic circuit board having a U-shaped void therein (sample No. 19) as shown in FIG. To 27). Table 2 shows the distance t and the width Y of each of the obtained samples.

Example 4 <Formation of Ceramic Circuit Board Having U-Shaped Void Inside> Silicon Nitride (Si ₃ N ₄ ) as Ceramic Material
8 parts by weight of Y ₂ O ₃ sintering aids per 100 parts by weight, 15 parts by weight of an acrylic organic binder, 1 part by weight of dibutyl phthalate as a plasticizer, toluene was added 40 parts by weight of a solvent A laminate was obtained in the same manner as in Example 3. After drying the obtained laminate, the organic matter is removed by heating in an atmosphere of about 600 ° C. for 3 hours, and further fired in a nitrogen atmosphere of about 1800 ° C., thereby forming a U-shaped inside as shown in FIG. Ceramic circuit boards having voids (Sample Nos. 28 to 36) were produced. Table 2 shows the distance t and the width Y of each of the obtained samples. The following evaluation tests were performed on the samples obtained in Examples 1 to 4.

Evaluation 1 <Deformation of surface of ceramic layer on void>
For each of the samples obtained in No. 4, the deformation state (maximum height difference) of the surface of the ceramic layer on the gap was measured using a laser displacement meter (LT8010 manufactured by Keyence Corporation). The results are shown in Tables 1 and 2.

Evaluation 2 <Appearance inspection and cross-sectional observation after thermal cycle test>
A Cu plate (circuit) having a width of 2 mm and a width of 12 mm was joined with an active solder having an AgCuTi composition, and a 10 mm
The corner heater chip (semiconductor component) was mounted by soldering. Next, a pipe was connected to the opening of each ceramic circuit board, and piping was arranged so that the refrigerant circulated from the cooling fins. As the refrigerant, a fluorine-based cooling liquid was used. A heat cycle test at −40 ° C. to 125 ° C. was performed on each of the samples of Examples 1 to 4 on which the heater chip was mounted. After 500 cycles of the heat cycle test, each sample was subjected to X-ray appearance inspection. Then, the ceramic circuit board of each sample was cut, and the state of the vicinity of the gap immediately below the circuit was observed with a microscope (20 to 200 times) to examine the presence or absence of peeling or cracking. The results are shown in Tables 1 and 2.

Evaluation 3 <Measurement of Thermal Resistance> Before and after the heat cycle test, the cooling fin was blown at 3 m / sec.
The power of W was applied to generate heat, and the temperature of the heater chip was measured three minutes after energization, and the thermal resistance of each ceramic circuit board was calculated. The results are shown in Tables 1 and 2.

[0054]

[Table 1]

[Table 2]

As shown in Tables 1 and 2, the sample N
o. In Samples Nos. 1, 10, 19, and 28, the distance t from the circuit to the gap was less than 0.5 mm. 7, 1
In 6, 25 and 34, since the width Y of the gap exceeds 20 times the distance t, the deformation of the ceramic layer surface is large,
The maximum height difference of the surface became a large value (67 to 11).
2 μm). In other samples, the distance t is 0.5
Since the condition of mm ≦ t ≦ 5 mm was satisfied and the relationship between the gap Y and the distance t satisfied Y ≦ 20t, the maximum height difference was a small value (4 to 12 μm).

Samples in which the maximum height difference was a large value in Evaluation 1 (Sample Nos. 1, 7, 10, 16, 1)
9, 25, 28, 34), peeling of the Cu plate was confirmed,
Among the above samples, sample No. 1, 7, 10,
19, 28, and 34, cracks were observed in the ceramic layer. No abnormalities were found in the other samples.

The sample in which the maximum height difference was a large value in the evaluation 1 had worse thermal resistance after the test than before the thermal cycle test. No changes were seen in the other samples. In particular, the sample satisfying Y ≧ 0.8 L (L: width of the semiconductor component) had a lower thermal resistance.

[0058]

According to the ceramic circuit board of the present invention, the distance t from the circuit to the gap in the board thickness direction is 0.5 mm ≦ t.
≤ 5 mm, and the width of the gap is Y, Y ≤
Since it has a relationship of 20t, there is an effect that it has sufficient strength to prevent deformation and high cooling performance can be obtained. Further, in the present invention, since the width Y of the gap portion and the width L of the semiconductor component are in a relationship of Y ≧ 0.8 L, the semiconductor component that has generated heat can be reliably cooled without causing malfunction. This has the effect. Further, according to the present invention, when a ceramic circuit board is manufactured, a predetermined gap portion (coolant flow path) is simultaneously formed in the board, so that it can be manufactured with a small number of steps, and is inexpensive and small in size as compared with the prior art. In addition, there is an effect that high reliability can be obtained.

[Brief description of the drawings]

FIG. 1 is an explanatory view schematically showing a ceramic circuit board of the present invention.

FIG. 2 is a perspective view showing a ceramic circuit board according to one embodiment of the present invention.

FIG. 3 is a perspective view showing a ceramic circuit board according to another embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 1 ceramic circuit board 2 gap 3 circuit 4 semiconductor component 11 ceramic circuit board 12 gap 12a opening 12b opening 21 ceramic circuit board 22 gap 22a opening 22b opening

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification FI FI Theme Court ゛ (Reference) H01L 23/427 H01L 23/46 23/473 A (72) Inventor Shinya Terao 1--1 Yamashita-cho, Kokubun-shi, Kagoshima Prefecture 4 Within Kyocera Research Institute (72) Inventor Makoto Imai 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Corporation (72) Inventor Yoshihide Arai 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Corporation F Terms (reference) 4G001 BA09 BA32 BB09 BB32 BC22 BC26 BC54 BD23 BE31 BE32 4G030 AA07 AA08 AA36 AA37 BA12 CA07 CA08 GA21 5E338 AA18 BB02 BB12 BB63 BB75 CD11 EE02 5F036 AA01 BA05 BA07 BB41 BD13

Claims (6)

[Claims] 1. A ceramic circuit board having a circuit on which a semiconductor component is mounted, wherein a void portion serving as a refrigerant flow path is formed below the circuit on which the semiconductor component is mounted, and a thickness of the substrate from the circuit to the void portion is provided. Distance t in the vertical direction is 0.5mm
A ceramic circuit board which satisfies the condition of ≦ t ≦ 5 mm, and wherein the distance t and the width Y of the gap have a relationship of Y ≦ 20t. 2. The width Y of the gap and the width L of the semiconductor component.
Are in a relationship of Y ≧ 0.8L. 3. At least one selected from aluminum oxide (Al ₂ O ₃ ), zirconium oxide (ZrO ₂ ), silicon nitride (Si ₃ N ₄ ), aluminum nitride (AlN) and silicon carbide (SiC). 3. The ceramic circuit board according to claim 1, comprising a sintered body as a main component. 4. A semiconductor component is cooled by a liquid cooling system or a boiling cooling system, wherein a coolant is circulated through the gap.
4. The ceramic circuit board according to any one of 3. 5. Extrusion molding a ceramic material into a mold,
A ceramic circuit board formed by obtaining a molded body having a void portion penetrating therein and then firing the molded body, wherein the void portion after firing satisfies the conditions of t and Y according to claim 1. A ceramic circuit board characterized by being formed as described above. 6. A ceramic circuit board formed by firing a laminate obtained by laminating a plurality of ceramic sheets,
2. A ceramic circuit board, wherein a void portion is formed inside the laminate, and the void portion after firing is formed so as to satisfy the conditions of t and Y according to claim 1.