JP3528376B2 - Substrate manufacturing method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the manufacture of a substrate (including a transmissive window which is required to have a high heat dissipation property) for mounting a semiconductor element having a large heat generation density such as an ultra high speed MPU and a high power semiconductor laser. Regarding the method.

[0002]

2. Description of the Related Art Semiconductor lasers used for submarine cables and the like have been increased in output in order to realize long-distance transmission, and the amount of heat generated by the element itself has been rapidly increasing accordingly.
Further, with the downsizing of information processing systems and the increase in processing speed, the improvement of the processing capacity per unit area of semiconductor elements incorporated in these devices is rapidly progressing. These things lead to an increase in the amount of heat generated per unit area of the semiconductor element, and the importance of ensuring the heat dissipation of the mounted substrate has attracted attention. On the other hand, various optical window materials typified by the window materials used in the synchrotron radiation experimental apparatus have become severer in the transmitted light intensity and the environment in which they are used. Therefore, it is expected that demands for mechanical strength and radioactivity of window materials will become more severe in the future.

[0003]

With the materials such as alumina currently used for the package, it is certain that the heat dissipation characteristics will become a problem when the above high-performance element is put into practical use. That is, in the current package, the thermal resistance is large, the heat generated by the device itself cannot be sufficiently dissipated, and the device temperature rises. As a result, the device malfunctions or runs out of control. In order to solve this problem, it is effective to use a material having higher thermal conductivity as described above, and diamond having the highest thermal conductivity among existing substances is also used in semiconductor laser diodes and the like.

However, the heat transported by the heat dissipation board must be finally transferred to the outside air or cooling water to be discharged. If the amount of heat generated by the mounted semiconductor element increases, it is of course necessary to use a high thermal conductivity material, and how to efficiently dissipate the large amount of heat that has conducted through the high thermal conductivity material from the substrate. Becomes important. Therefore, a fin and a cooling water pipe are attached to the back surface of the substrate to increase the heat radiation area and heat radiation efficiency. However, if the cooling water pipe is attached to the back side of the board, it is not possible to prevent extra heat resistance from entering that attachment part, and the fins will have a lower cooling efficiency, and thus have high heat dissipation that enables more efficient cooling. Substrate development is required.

Japanese Unexamined Patent Publication No. 4-273466 proposes a structure in which a coolant is flowed in a three-dimensional integrated circuit board using diamond by forming a hole in the side surface of the board.
However, in this structure, the vicinity of the center of the substrate (the part where the temperature is expected to rise most) is farthest from the place where the refrigerant passes, and the efficiency is poor.

Examples of materials used as various transmission window materials include Be, Si and ZnSe. When these window materials are irradiated with light of large energy, the temperature of the window materials themselves rises, causing problems such as melting and deterioration. Therefore, measures such as cooling from around the window material have been taken, but they have not been sufficient.

[0007]

In view of the above problems, the inventors of the present invention have conducted extensive studies to obtain a substrate with a higher cooling efficiency, and have established a flow path for directly passing a coolant through the substrate. By forming it, we succeeded in obtaining a substrate with significantly improved heat dissipation efficiency than conventional substrates.

According to the present invention, a) a thin plate made of a highly heat-conductive material having a thermal conductivity of 10 W / cm · K or more is used to form a flow path for a cooling medium to pass through by using a laser beam. And a step of b) adhering a base material to the processed surface, the method for manufacturing a substrate is provided. Also,
The present invention comprises a step of forming a flow path for passing a cooling medium by using a laser beam on one surface of a plate made of a highly heat conductive material having a thermal conductivity of 10 W / cm · K or more, and Provided is a method for manufacturing a substrate, which comprises the step of adhering another plate made of a highly heat-conductive material having a thermal conductivity of 10 W / cm or more to the surface provided.

In addition, the present invention has a thermal conductivity of 10 W / cm.
There is provided a method for manufacturing a substrate, which comprises a step of forming a flow path through which a cooling medium passes using a laser beam from a side surface of a plate made of a material having a high thermal conductivity of K or more. Furthermore, the present invention provides: a) thermal conductivity of 10 W / cm.
A step of partially applying a mask to one surface of a thin plate made of a material having high thermal conductivity of K or higher, and b) A channel for passing a cooling medium by selectively etching an unmasked portion. And a step of removing the mask, and a step of adhering a base material to the processed surface.

In addition to the above, the present invention further comprises the steps of forming a groove in a plate-shaped material, growing diamond on the plate-shaped material by a vapor phase synthesis method, and removing the plate-shaped material to make the grooved diamond self-supporting. There is provided a method for manufacturing a substrate, which includes a step of obtaining a film and a step of adhering a base material to the surface having the groove. Furthermore, the present invention includes a step of applying a mask to the base material, a step of growing diamond by a vapor phase synthesis method, and a step of removing the mask to obtain a flow path for passing a cooling medium. A method of manufacturing a substrate is provided. Furthermore, the present invention, a step of applying a mask to the plate-shaped material, a step of growing diamond by a vapor phase synthesis method, a step of removing the mask and the plate-shaped material to obtain a grooved diamond free-standing film,
There is provided a method for manufacturing a substrate, including a step of adhering a base material to a surface of the self-supporting film in which a groove is formed.

In the present invention, the term "substrate" refers to
It includes not only a substrate on which a semiconductor element is mounted but also a transmission window.

The specific contents of the present invention will be disclosed in detail below. In one form of the substrate in the present invention, the high thermal conductive material layer is laminated on the base material,
At the interface between the high thermal conductive material layer and the base material, a groove for flowing a refrigerant is formed on the high thermal conductive layer side. That is, the heat generated from the heating element such as a semiconductor device arranged on the surface of the high thermal conductive material layer is transmitted through the high thermal conductive material layer with a small temperature gradient and passes through the groove formed on the back surface of the material layer. Is efficiently removed by the refrigerant.

As the high thermal conductivity material layer, it is preferable that the thermal conductivity is higher because the element temperature can be suppressed. The higher the thermal conductivity, the better, but 10 W / cm · K or more is suitable. Examples of substances having such a material include natural diamond, high-pressure synthetic diamond, and vapor-phase synthetic diamond. All of these are suitable as the high thermal conductive material layer in the present invention,
In particular, when diamond obtained by the vapor phase synthesis method is used, a relatively large area high thermal conductivity material layer can be obtained at low cost. The thermal conductivity is generally temperature-dependent, and the thermal conductivity of the diamond decreases with increasing temperature in the temperature range above room temperature. In the case of a board on which an ordinary semiconductor element is mounted, the temperature of the mounted element is 100 ° C to 200 ° C at most, and the thermal conductivity is 10W in this temperature range.
/ Cm · K or more is also desirable in the high thermal conductive material layer in the present invention. The thickness of the high thermal conductive material layer is
It is preferably at least 30 μm or more, more preferably 70 μm or more. The upper limit of the thickness of the highly conductive material layer is usually 10 mm, for example 5 mm. The high thermal conductivity material may be semi-conductive or conductive, but is preferably insulative. The resistivity of high thermal conductive material is 1 × 10 ⁸
It is preferably Ω · cm or more, more preferably 1 × 10 ⁹ Ω · cm or more.

Regarding the grooves existing in the high thermal conductivity material layer, the deeper the depth, the higher the heat exchange rate, but if it is too deep, the mechanical strength becomes weak, which is not preferable.
Specifically, the depth (c) of the groove is 20 μm or more, more preferably 50 μm or more. The depth of the groove is preferably less than 90%, more preferably less than 80% of the film thickness of the high thermal conductive material layer. Also, the wider the width (a) of the groove, the higher the heat exchange rate, but instead the number of grooves is reduced in order to maintain the strength of the portion in contact with the base material. become worse. On the other hand, the groove spacing (b) is similar to the width, and it is neither too wide nor too narrow. The width and spacing of the grooves are preferably 20 μm or more and 10 mm or less, more preferably 40 μm or more and 2 mm or less. Regarding the range of the ratio (a / b) of the length of the width (a) to the length of the interval (b), in the case of a semiconductor substrate, the lower limit is 0.02, more preferably 0.04, while the upper limit is , 50, more preferably 25, while in the case of a window material, the lower limit is 0.02, more preferably 0.04, while the upper limit is 10, more preferably 5. Is desirable. The ratio of the length of width (a) to depth (c) (a /
Regarding the range of c), in the case of a semiconductor substrate, the lower limit is
0.05, more preferably 0.1, while the upper limit is 1
00, more preferably 50, on the other hand, in the case of a window material, the lower limit is 0.02, more preferably 0.05, while the upper limit is 50, more preferably 25. It is desirable (see FIG. 4).

However, the optimum widths and intervals depend on the elements mounted on the heat dissipation board. The shape of the groove does not have to be rectangular in cross section, and may be semicircular, semielliptic, or a more complicated shape. Further, the values of a, b, and c described above do not have to be constant in one substrate, and can be changed under the conditions shown above. The ratio of the surface of the high thermal conductive material layer occupied by the groove is usually 2 to 2 in the case of the semiconductor substrate with respect to the surface area of the high thermal conductive material layer.
90%, preferably 10 to 80%, and in the case of window materials, it is usually 2 to 75%, preferably 10 to 50%. The angle (taper angle) between the side surface of the groove and the vertical line with respect to the surface of the high thermal conductive material layer is preferably 30 ° or less.

The groove through which the coolant passes can be appropriately formed according to the arrangement of the heating element such as a semiconductor element installed on the main substrate. It is desirable to form the groove so that the portion that generates the most heat or the portion that requires the lowest temperature is cooled most efficiently by the heating element such as the mounted semiconductor element. Specifically, the grooves are arranged so that the refrigerant most passes through the portion to be cooled most. The cooling efficiency can also be improved by making the cross-sectional shape of the groove complicated and increasing the surface area of the groove. Also,
Since the temperature of the refrigerant is lowest near the inlet of the refrigerant, the cooling efficiency is high. Therefore, if the calorific value distribution of the heating element is almost even, the temperature will be highest in the central part, so it is efficient to provide an inlet in the central part and arrange the refrigerant groove in a spiral or radial shape from there. Good.

The groove is formed after forming the high thermal conductive material layer.
The material layer can be formed by laser processing (for example, using an excimer laser), processing by an etching method, or the like. A layer of a non-diamond carbon component (for example, graphite or amorphous carbon) having a thickness of 1 nm or more and 1 μm or less may be present on the surface of the groove. The non-diamond layer is formed by subjecting the high thermal conductive material layer to a temperature of 1000 to 1500 ° C. for 30 minutes to 10 hours (eg, 1 to 1) in a non-oxidizing atmosphere (for example, an inert gas atmosphere).
It can be formed by heating for a time (in this case, a non-diamond layer is also formed on the surface of the high thermal conductive material layer other than the groove, which can be removed by polishing or the like). .). The presence or absence of the non-diamond layer can be measured by Raman spectroscopy.

It is preferable that the surface of the groove has good wettability with the refrigerant. The contact angle is usually 65 ° or less, more preferably 60 ° or less.
Since hydrogen atoms are present on the surface of diamond, in this state, it repels a coolant such as water. Therefore, instead of a hydrogen atom, a hydrophilic group containing an oxygen atom (for example, OH
By adding a base), the hydrophilicity of the diamond layer surface can be increased. In order to improve the wettability of the surface of the groove, for example, annealing is performed at 500 to 800 ° C. for 10 minutes to 20 hours in an oxidizing atmosphere (for example, air atmosphere), or treatment with oxygen or a gas containing oxygen is performed. do it. When oxygen plasma is used as the method for forming the grooves, it is considered that the hydrophilicity is increased to some extent, but the above-mentioned operation for improving wettability may be further performed. Further, as the treatment for improving the wettability of the surface of the groove with respect to the coolant, in addition to the above, plasma treatment in a gas containing nitrogen, boron or an inert gas can be mentioned.

After forming the groove, the high thermal conductivity layer is laminated to the substrate. The bonding may be performed with a metal, an adhesive, or the like. The thickness of the metal layer or adhesive layer is usually 0.
It is from 01 to 10 μm. Alternatively, the bonding may be performed by directly attaching the high thermal conductivity layer to the base material without using a substance such as metal.

The base material is, for example, B, Be, Al, Cu,
It is made of materials such as Si, Ag, Ti, Fe, Ni, Mo, W, alloys thereof and compounds thereof (for example, carbides and nitrides). When used as a window material, the base material can be used properly depending on the application. For example, Be can be used as the X-ray transmission window, and Si, ZnSe, or the like can be used as the infrared transmission window. The substrate may be insulative, for example. The substrate may be plate-shaped. The thickness of the substrate is usually 0.1 to 10 mm, preferably 0.1.
It is 5 to 5 mm.

When the device is mounted on the substrate, the device is preferably arranged on the high thermal conductive material layer. As the refrigerant, for example, water, air, an inert gas (for example, nitrogen, argon, etc.), fluorocarbon, liquid nitrogen, liquid oxygen, liquid helium, etc. are used. The substrate of the present invention is a semiconductor device such as a laser chip or MPU.
And various optical window materials (for example, infrared rays, ultraviolet rays, X
It is useful for wire, window material for SOR, etc.).

Now, a method of manufacturing a substrate having the groove through which the coolant passes at the interface with the base material will be described below. First, a method of adhering a high thermal conductive substance layer having a coolant passage groove to a base material will be described. A substance to be the high thermal conductive substance layer is prepared in a desired size. In order to arrange the groove through which the coolant passes, a processing method using a laser beam, selective etching, or the like can be used. In the laser processing, the material is removed by focusing a laser beam on the surface of the material to form a groove on the surface. According to this method, it is possible to obtain grooves having an arbitrary arrangement. A laser beam having a sufficient energy density is focused on the surface of the high thermal conductivity material, and the focusing position is gradually moved while deleting the material to form a groove on the surface. As the laser beam, a YAG laser, an excimer laser or the like can be used, but the excimer laser is particularly preferable in terms of its processing accuracy.
It is preferable that the grooves having an arbitrary depth and arrangement can be formed with good reproducibility.

The wavelength of the laser light is preferably 360 nm or less, for example, in the range of 190 to 360 nm. The energy density of the irradiation light is 10 to 10 ¹¹ W / cm ² . Energy density per pulse is 10 ^-1 J / cm ² or more using pulsed laser light and 10 ⁶ J / cm 2
The range is preferably ² or less. Furthermore, the divergence angle of the laser light when oscillated by the laser oscillator is 1
It is preferable to set it to 0 ^{−2 to 5} × 10 ⁻¹ mrad, and to set the half width of the oscillation spectrum of the laser beam to 10 ⁻⁴ to 1 nm. The uniformity of energy distribution in the beam cross section of the laser light is preferably 10% or less. Good processing results are obtained by focusing the pulsed laser light with a cylindrical lens or a cylindrical mirror. In such surface groove processing by the excimer laser, by performing the processing in an appropriate atmosphere, the diamond surface can be modified and the wettability with the refrigerant can be improved. For example, by performing the above-mentioned processing in the atmosphere of an amino group-containing compound (for example, ammonia, hydrazine, etc.), an amino group can be introduced into the surface of the formed groove, and hydrophilicity can be improved.

On the other hand, the surface groove processing by the etching method is
It can be done as follows. That is, after forming an appropriate mask on the high thermal conductive material layer, the mask is not etched, and only the high thermal conductive material is etched. After that, the mask is removed to obtain a high thermal conductive material layer having grooves on the surface. It is known that Al or SiO ₂ can be formed as a mask material on diamond and the diamond can be selectively etched by oxygen or a gas containing oxygen (53rd Proceedings of the Society of Physical and Chemical Engineering, Second Volume, Volume 411). (See page), this technology can be used to form grooves on diamond. Alternatively, nitrogen or hydrogen may be used instead of oxygen or a gas containing oxygen.

By attaching the high thermal conductive material layer having the desired groove thus formed to a separately prepared base material,
It is possible to obtain a substrate having a very large heat dissipation efficiency. The base material is provided with an inlet / outlet for introducing the cooling medium to be separately passed through the groove provided in the layer.

Adhesion between the high thermal conductive material layer and the substrate is
It can be performed by a metallizing process or by an adhesive. It may be performed by metalizing the two surfaces to be bonded by a known method and melting the metal. Examples of metals used in the metallization treatment are Ti, P
t, Au, Sn, Pb, In, Ag and the like. Adhesive (eg Ag / epoxy type, Ag / polyimide type, A
u / epoxy based) or Ag based brazing agents, and other bonding methods may be used.

When diamond synthesized by the vapor phase synthesis method is used as the high thermal conductive material layer, selective growth using a mask should be used to form the groove, rather than processing by laser beam or etching method. You can This is disclosed in, for example, Japanese Patent Laid-Open No. 1-1047661,
It is disclosed in Japanese Laid-Open Patent Publication No. 1-123423. If a mask material is placed on the surface of a base material (for example, Si, SiC, Cu, Mo, cBN, etc.) in a shape corresponding to the groove in which the mask material is to be formed, and diamond is laminated thereon by the vapor phase synthesis method. Good. At this time, by growing the diamond by 50 μm or more, the diamond grows laterally also on the upper part of the mask, and as a result, the whole surface is covered. After that, if the base material is removed by a method such as melting, the diamond taken out has grooves on the base material surface side. The mask is
Ti, SiO ₂ , Mo and the like may be formed by a known method. The advantage of this method is that since it is not necessary to give an impact after growing the diamond, it is unlikely to be damaged during processing.

In the above method, instead of forming a mask, the plate-shaped material itself is processed to form irregularities in a shape corresponding to the groove, and diamond can be grown on it by vapor phase synthesis. . When the plate-shaped material is removed after the growth to a desired thickness, a diamond free-standing film having a groove on the plate-shaped material surface side can be obtained. Examples of the plate-shaped material include Si, SiC, Mo and the like.

Furthermore, when vapor phase synthetic diamond is used as the high thermal conductivity material layer, the above method is developed,
The step of bonding can be omitted. That is, a mask is first placed on the base material, and after vapor phase synthetic diamond is grown on the base material, only the mask is melted to form a groove through which a coolant passes on the diamond side of the interface between the base material and the diamond. A substrate having can be obtained. According to this method, since it is not necessary to use an adhesive material, the heat dissipation efficiency of the entire substrate can be further increased. As such a base material, Si, SiC, Cu and Mo are preferable.

In any of the above methods, the high thermal conductivity material layer /
This is effective for manufacturing a substrate having a groove on the high thermal conductive layer side of the interface of the base material. The etching method can form fine grooves with high precision. The method using laser processing has a high formation speed. Further, in the method using selective growth (method using a mask), it is easy to form a relatively large groove.

In another form of the substrate according to the present invention,
The upper and lower directions and the lateral direction of the flow path are surrounded by the high thermal conductive material. That is, the heat generated from the heating element such as a semiconductor element arranged on the surface of the substrate is transmitted through the high thermal conductivity material with a small temperature gradient, and is efficiently removed by the refrigerant passing through the flow path.

As the high thermal conductivity material, it is preferable that the thermal conductivity is higher because the element temperature can be suppressed. The higher the thermal conductivity, the better, but 10 W / cm · K or more is suitable. Examples of substances having such a material include natural diamond, high-pressure synthetic diamond, and vapor-phase synthetic diamond. All of these are suitable as the high thermal conductivity substance in the present invention, but particularly when diamond obtained by the vapor phase synthesis method is used, a relatively large area high thermal conductivity substance can be obtained at low cost. The thermal conductivity is generally temperature-dependent, and the thermal conductivity of the diamond decreases with increasing temperature in the temperature range above room temperature.

In the case of a board on which an ordinary semiconductor element is mounted,
The temperature of the mounted element is at most 100 ° C. to 200 ° C., and it is desirable that the high thermal conductivity material of the present invention has a thermal conductivity of 10 W / cm · K or more in this temperature range. When used as a window material for SOR light or the like, the irradiation energy is enormous, so that the conventional type window material also rises in temperature to several hundred degrees Celsius.
Then, even if diamond is used, its thermal conductivity is unavoidably lowered. However, by using the window material of the present invention, it is possible to increase the heat dissipation effect, so that the temperature rise of the window material itself can be prevented and the thermal conductivity can be kept high.

The thickness of the substrate is preferably 30 μm or more, more preferably 70 μm or more. The upper limit of the thickness of the substrate is usually 10 mm, for example 5 mm. The high thermal conductivity material may be semi-conductive or conductive, but is preferably insulative. The resistivity of high thermal conductive material is
1 × 10 ⁸ Ω · cm or more, more preferably 1 × 10 ⁹ Ω · cm
The above is preferable.

The flow path is typically rectangular in cross section. The heat exchange rate increases as the height of the flow path increases, but if it is too high, the mechanical strength of the flow path decreases, which is not preferable. Specifically, the height (c) of the flow path is 20 μm or more, more preferably 50 μm or more. The height of the flow path is preferably less than 90% of the thickness of the substrate, more preferably less than 80%. Also, the width of the channel (a)
The wider the ratio, the higher the heat exchange rate, but since the number of channels is small to maintain the strength of the substrate, the heat exchange rate will be worse if the width is too wide. On the other hand, the spacing (b) of the flow paths is the same as the width, and it is neither too wide nor too narrow. The width and spacing of the channels are preferably 20 μm or more and 10 mm or less, more preferably 40 μm or more and 2 mm or less.

Regarding the range of the ratio (a / b) of the width (a) and the interval (b), the lower limit is 0.02 in the case of a semiconductor substrate,
More preferably, it is 0.04, while the upper limit is 50,
More preferably, it is preferably 25, and in the case of a window material, the lower limit is preferably 0.02, more preferably 0.04, while the upper limit is preferably 10, and more preferably 5. Regarding the range of the ratio (a / c) of the width (a) and the height (c), the lower limit is 0.
05, more preferably 0.1, while the upper limit is 10
The lower limit is preferably 0.02, more preferably 50, and in the case of a window material, the lower limit is 0.02, more preferably 0.05, while the upper limit is 50, more preferably 25. .

However, regarding the optimum width, spacing, and height,
It depends on the elements mounted on the substrate and the heat generation state of the substrate. The shape of the flow path does not have to be rectangular in cross section, and may be semicircular, semielliptic, or a more complicated shape. Further, the values of a, b, and c described above do not have to be constant in one substrate, and can be changed under the conditions shown above. The ratio of the surface of the substrate occupied by the flow path (the ratio of the area occupied by the flow path to the surface of the substrate when viewed in the direction perpendicular to the plane of the substrate) is
It is usually 2 to 90%, preferably 10 to 80%, and when it is a window material, it is usually 2 to 75%, preferably 10 to 50%.
%. The angle (taper angle) between the side surface of the flow path and the vertical line with respect to the surface of the substrate is preferably 30 ° or less.

The flow path can be formed appropriately according to the arrangement of a heating element such as a semiconductor element installed on the substrate. It is desirable to form the flow path so that the most heat generating portion or the portion requiring the lowest temperature is cooled most efficiently. Specifically, the flow passages are arranged so that the refrigerant most passes through the portion to be cooled most. The cooling efficiency can also be improved by making the cross-sectional shape of the flow channel complicated and increasing the surface area of the flow channel. Further, since the temperature of the refrigerant is the lowest in the vicinity of the refrigerant inlet, the cooling efficiency becomes high. Therefore, if the heat generation amount distribution of the heating element is almost uniform, the temperature will be highest in the central part, so it is efficient to provide an inlet in the central part and arrange the refrigerant flow path spirally or radially from there. Good.

A layer made of a non-diamond carbon component (for example, graphite or amorphous carbon) having a thickness of 1 nm or more and 1 μm or less may be present on the surface of the channel. The non-diamond layer is formed of a high thermal conductive material film of 1000 to 1500 in a non-oxidizing atmosphere (for example, an inert gas atmosphere).
It can be formed by heating at 30 ° C. for 30 minutes to 10 hours (for example, 1 hour) (in this case, the non-diamond layer is also formed on the surface of the substrate other than the flow channel. It can be removed by polishing etc.). The presence or absence of the non-diamond layer can be measured by Raman spectroscopy.

It is preferable that the surface of the channel has good wettability with the refrigerant. The contact angle is usually 65 ° or less, more preferably 60 ° or less.
Since hydrogen atoms are present on the surface of diamond, in this state, it repels a coolant such as water. Therefore, instead of a hydrogen atom, a hydrophilic group containing an oxygen atom (for example, OH
By adding a base, the hydrophilicity of the diamond film surface can be increased.

To improve the wettability of the surface of the flow channel, for example, in an oxidizing atmosphere (for example, air atmosphere),
It may be annealed at 0 to 800 ° C. for 10 minutes to 10 hours, or may be treated with plasma of oxygen or a gas containing oxygen. When oxygen plasma is used as the method of forming the flow channel, it is considered that the hydrophilicity is increased to some extent, but the above-mentioned operation for improving wettability may be further performed.

Further, as the treatment for improving the wettability of the surface of the flow path with respect to the refrigerant, there can be mentioned plasma treatment in a gas containing nitrogen, boron or an inert gas, in addition to the above.

As the refrigerant, for example, water, air, inert gas (for example, nitrogen, argon, etc.), fluorocarbon, liquid nitrogen, liquid oxygen, liquid helium, etc. are used. The substrate of the present invention is a substrate of a high thermal conductive material, a base material other than the high thermal conductive material [thickness 0.1 to 10 mm, for example, B,
Be, Al, Cu, Si, Ag, Ti, Fe, Ni, M
o, W, their alloys and their compounds (for example,
Carbides, nitrides)].
The substrate of the present invention is useful in semiconductor devices such as laser chips and MPUs. Also, synchrotron radiation,
For example, it is also useful as a window material that transmits infrared rays, ultraviolet rays, X-rays, and SOR radiation light.

Now, a method of manufacturing a substrate having a flow path will be described below. The substrate can be formed by, for example, laser processing or the like to directly form a hole in the side surface of the substrate to form a flow path. Alternatively, the substrate can be formed by forming a groove in one film and then bonding another film.

In the former method, first, a plate made of a highly heat-conductive substance having a desired shape is prepared, and a laser beam is focused on this side face to form a hole, and a coolant is placed inside the high-heat conductive substance plate. A flow passage is formed.

A method of obtaining the first high thermal conductivity substance film and the second high thermal conductivity substance film by bonding is shown below. The first high thermal conductivity material film has a groove that serves as a flow channel, and the second high thermal conductivity material film has no groove.
A film made of a material having high thermal conductivity is prepared in a desired size.
On one surface of the first high thermal conductivity material film, a flow path to be embedded inside at the time of completion is formed by a laser beam processing method, a selective etching processing method, or the like.

In the laser processing, the material is removed by focusing a laser beam on the surface of the material to form a groove on the surface. According to this method, it is possible to obtain a flow path having an arbitrary arrangement. A laser beam having a sufficient energy density is focused on the surface of the high thermal conductivity material, and the focusing position is gradually moved while deleting the material to form a groove on the surface. As the laser beam, a YAG laser, an excimer laser, or the like can be used. In particular, the excimer laser is preferable because it can form a flow path having an arbitrary depth and arrangement with good reproducibility in terms of its processing accuracy.

The wavelength of the laser light is preferably 360 nm or less, for example, in the range of 190 to 360 nm. The energy density of the irradiation light is 10 to 10 ¹¹ W / cm ² . Energy density per pulse is 10 ^-1 J / cm ² or more using pulsed laser light and 10 ⁶ J / cm 2
The range is preferably ² or less. Furthermore, the divergence angle of the laser light when oscillated by the laser oscillator is 1
It is preferable to set it to 0 ^{−2 to 5} × 10 ⁻¹ mrad, and to set the half width of the oscillation spectrum of the laser beam to 10 ⁻⁴ to 1 nm. The uniformity of energy distribution in the beam cross section of the laser light is preferably 10% or less. Good processing results are obtained by focusing the pulsed laser light with a cylindrical lens or a cylindrical mirror. In such surface groove processing by the excimer laser, by performing the processing in an appropriate atmosphere, the diamond surface can be modified and the wettability with the refrigerant can be improved. For example, by performing the above-mentioned processing in the atmosphere of an amino group-containing compound (for example, ammonia, hydrazine, etc.), an amino group can be introduced into the surface of the formed groove, and hydrophilicity can be improved.

On the other hand, the flow path formation by the etching method can be performed as follows. That is, after forming an appropriate mask on the high thermal conductive material film, the mask is not etched, and only the high thermal conductive material is etched. After that, the mask is removed to obtain a first high thermal conductive material film having grooves on the surface. It is known that Al or SiO ₂ can be formed as a mask material on diamond and the diamond can be selectively etched by oxygen or a gas containing oxygen (53rd Proceedings of the Society of Physical and Chemical Engineering, Second Volume, Volume 411). (See page), this technology can be used to form grooves on diamond. Alternatively, nitrogen or hydrogen may be used instead of oxygen or a gas containing oxygen.

By adhering the first high thermal conductive material film having the desired groove formed thereon to the separately prepared second high thermal conductive material film, it is possible to obtain a substrate having a very high heat dissipation efficiency. The second high thermal conductive material film may be separately provided with an inlet / outlet for introducing a cooling medium to be passed through the flow path.

Although the method of forming the groove only on the first high thermal conductive material film has been described above, the film is also formed on the second high thermal conductive material film, and the surfaces having both grooves are bonded to each other. You can also However, in this case, the process becomes complicated.
It is preferable to form the groove only in the high thermal conductive material film.

The first high thermal conductivity substance film and the second high thermal conductivity substance film can be attached by a metallizing treatment or an adhesive. It may be performed by metalizing the two surfaces to be bonded by a known method and melting the metal. Examples of metals used in the metallization treatment are Ti, Pt, Au, Sn, Pb, In, Ag.
And so on. Adhesives (eg Ag / epoxy, Ag
/ Polyimide based, Au / epoxy based) or Ag based brazing agents, and other bonding methods may be used. The thickness of the adhesive layer is usually 0.01 to 10 μm.

When diamond synthesized by the vapor phase synthesis method is used as the high thermal conductive material film, the selective growth using a mask is used to form the groove, instead of processing by a laser beam or an etching method. You can This is disclosed in, for example, Japanese Patent Laid-Open No. 1-1047661,
It is disclosed in Japanese Laid-Open Patent Publication No. 1-123423. If a mask material is placed on the surface of a base material (for example, Si, SiC, Cu, Mo, cBN, etc.) in a shape corresponding to the groove in which the mask material is to be formed, and diamond is laminated thereon by the vapor phase synthesis method. Good. At this time, by growing the diamond by 50 μm or more, the diamond grows laterally also on the upper part of the mask, and as a result, the whole surface is covered. After that, if the base material is removed by a method such as melting, the diamond taken out has grooves on the base material surface side. The mask is
Ti, SiO ₂ , Mo and the like may be formed by a known method. The advantage of this method is that since it is not necessary to give an impact after growing the diamond, it is unlikely to be damaged during processing.

In the above method, instead of forming a mask, the plate-shaped material itself is processed to form irregularities in a shape corresponding to the groove, and diamond can be grown on it by vapor phase synthesis. . When the plate-shaped material is removed after the growth to a desired thickness, a diamond free-standing film having a groove on the plate-shaped material surface side can be obtained. Examples of the plate-shaped material include Si, SiC, Mo and the like.

Furthermore, when vapor phase synthetic diamond is used as the high thermal conductive material film, the above method is developed,
The step of bonding can be omitted. That is, a substrate having a channel can be obtained by first attaching a mask on the diamond film, growing vapor-phase synthetic diamond on the diamond film, and then dissolving only the mask. According to this method, since it is not necessary to use an adhesive material, the heat dissipation efficiency of the entire substrate can be further increased.

Any of the above methods is effective for manufacturing a substrate having a flow path. The etching method can form fine grooves with high precision. The method using laser processing has a high formation speed. Further, in the method using selective growth (method using a mask), it is easy to form a relatively large groove. Hereinafter, the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a plan view showing the concept of the grooved high thermal conductive material layer in the present invention. High thermal conductive material layer 11
The groove 12 is provided on the substrate so that the surface on which the groove is not formed has a comb shape. FIG. 2 is a side view of the heat dissipation board according to the present invention. The heat dissipation board 16 has a high thermal conductive material layer 11, a base material 13, and an adhesive layer 15. The base material 13 is provided with two refrigerant inlet / outlet ports 14 communicating with the groove 12. Refrigerant entrance / exit 1 in base material 13
The size and number of 4 are not particularly limited. For example, there may be a refrigerant inlet / outlet on each of the portions of the substrate that correspond to the ends of the groove. FIG. 3 is a plan view showing the concept of the grooved high thermal conductive material layer in the present invention. The high thermal conductive material layer 21 is provided with spiral grooves 22. Figure 4
FIG. 6 is a cross-sectional view showing a groove formed in a high thermal conductive material layer.
The groove 12 has a width a and a depth c, and is formed at intervals b.

FIG. 5 is a plan view showing the substrate of the present invention. A flow channel 112 is formed in the substrate 111, and the flow channel 112 is embedded inside the substrate. FIG. 6 is a front view of the substrate of FIG. The substrate 111 includes a first high thermal conductivity substance film 113 having a flow channel 112 formed therein, a second high thermal conductivity substance film 114, and an adhesive layer 115. The flow path 112 is connected to the two refrigerant inlet / outlets 116.
The refrigerant inlet / outlet 116 need not be in such a position,
It may be provided on the main surface of the first high thermal conductivity substance film 113 or the second high thermal conductivity substance film 114. The size and number of the refrigerant inlet / outlet ports are not particularly limited.

FIG. 7 is a plan view showing another substrate of the present invention. A flow path 122 is formed in a spiral shape on the substrate 121. FIG. 8 is a sectional view showing a flow channel formed in the substrate in the present invention. The channel 112 has a width a and a height c.
And are formed at intervals b.

FIG. 9 shows the Raman spectra of diamond and non-diamond carbon. Curve a is the spectrum of diamond and has a strong peak at 1333 cm ^-1 . A curve b is a spectrum of a substance containing a large amount of non-diamond carbon and has two broad peaks.

[0061]

EXAMPLES The present invention will be specifically disclosed below with reference to examples. Example 1 Diamond was grown by a microwave plasma CVD method on a polycrystalline Si substrate (10 mm × 10 mm × thickness 2 mm) that had been subjected to CVD, laser grooving, bonding, and CuW: scratch treatment. The growth conditions were 1% methane-hydrogen system, the pressure was 80 Torr, and the substrate temperature was 900 ° C. After the growth for 400 hours, the growth surface was polished and the Si substrate was dissolved with an acid to obtain a self-supporting diamond film of 10 mm x 10 mm x 0.5 mm in thickness. The thermal conductivity was measured to be 17.2W
It was / cm · K.

A KrF excimer laser was line-focused and point-focused on one surface of the free-standing diamond film obtained as described above to form a groove as shown in FIG. The groove depth is about 150μ
m, the width was about 500 μm, and the spacing was about 400 μm. This grooved diamond and CuW alloy (10mm x 10mm
After depositing Ti, Pt, and Au on both (x thickness 2 mm),
Bonding was done by melting the Au. Ti / Pt /
The thickness of the Au / Pt / Ti layer was 0.1 μm. CuW
The alloy is preliminarily provided with a refrigerant inlet / outlet (diameter: 400 μm) to be introduced into the diamond groove (FIG. 2). Cooling water (water temperature: 25 ° C.) was supplied to the grooves of the grooved diamond / CuW substrate manufactured as described above. At this time, the thermal resistance between the diamond surface and the coolant water was measured and found to be 0.014 ° C./W.

Example 2 High-pressure synthesis, grooving laser, attachment, CuW: Ib type diamond (8 mm × 8 mm × 0.6 m) synthesized under high temperature and high pressure
A grooved diamond / CuW substrate was prepared in the same manner as in Example 1 using m and thermal conductivity of 18.3 W / cm · K). However, the grooves formed in the diamond are formed by using an ArF excimer laser and have a depth of about 200 μm, a width of about 350 μm, and an interval of about 40 μm.
It was 0 μm (FIG. 3). In the groove of the grooved diamond / CuW substrate thus produced, cooling water (water temperature 2
5 ° C.) was supplied. At this time, the thermal resistance between the surface of the diamond and the water of the coolant was measured and found to be 0.021 ° C /
It was W.

Example 3 CVD, etching, and sticking: Under the same conditions as in Example 1, a self-standing diamond film of 10 mm × 10 mm × thickness of 0.25 mm was obtained. On this one side, Al mask pattern with line width 1
The layers were formed with a spacing of 00 μm and a spacing of 50 μm. This was plasma-etched with a mixed gas of argon and oxygen. Oxygen ratio 20%, total pressure 0.05 Torr, RF output 200W
Then, the treatment was performed for 3 hours. After the treatment, Al was dissolved and removed with an acid to obtain a grooved diamond free-standing film having a depth of 50 μm, a line width of 50 μm, and an interval of 100 μm. A diamond free-standing film is adhered on a Be substrate (10 mm x 10 mm x thickness 3 mm) (Ti / Pt / Au metallization is applied to the periphery of the substrate,
After that, brazing was performed using an Ag-based brazing material. ), The window material was obtained. This window material was used as a window material for a synchrotron radiation (SOR) beam line (500 MeV). Fluorocarbon (CFC 112) as a refrigerant (25 ° C)
It was used. No change (or alteration) was observed after 10 hours of radiation.

Example 4 CVD, Grooving Selective Growth, Sticking: First, a mask made of Ti was formed as shown in FIG. 3 on a polycrystalline Si base material (10 mm × 10 mm × thickness 2 mm) which had been subjected to a scratch treatment. Diamond was grown on this substrate by the hot filament CVD method. The growth conditions are methane 2% -hydrogen system, pressure 80 Tor.
r, filament temperature is 2100 ° C, substrate temperature is 880
It was ℃. When grown for 650 hours, the diamond grown from Si covered the entire substrate including the Ti mask, and the thickness was about 950 μm. The growth surface was polished, the mask and the Si base material were dissolved and removed with an acid, and a diamond free-standing film (thickness 850 μm) having a groove on the back surface was obtained.
The groove spacing is about 700 μm, the width is about 300 μm, and the depth is about 8
It was 0 μm. When the thermal conductivity of this substrate was measured, it was 14.8 W / cm · K. The grooved diamond obtained as described above was bonded onto a CuW alloy.
The CuW alloy is provided with an inlet / outlet for a coolant to be introduced into the diamond groove in advance. Cooling water (water temperature 25 ° C.) was supplied in the same manner as in Examples 1 and 2. At this time, the thermal resistance between the diamond surface and the coolant water was measured and found to be 0.018 ° C./W.

Example 5 CVD, Grooving Selective Growth, Integration: As in Example 3,
Ti on a polycrystalline SiC substrate (10 mm x 10 mm x thickness 4 mm)
After forming the mask, diamond was grown by the hot filament CVD method. At this time, the polycrystalline SiC base material was previously provided with inlets and outlets for introducing the cooling medium at both ends of the mask (portions that finally become grooves). After this,
Only Ti of the mask was dissolved and removed with an acid to obtain a grooved diamond / SiC substrate. Cooling water as in Examples 1 and 2.
(Water temperature 25 ° C.) was supplied. At this time, the thermal resistance between the surface of the diamond and the water of the coolant was measured and found to be 0.025.
C / W.

Example 6 Air Annealing In the same manner as in Example 1, a grooved diamond as shown in FIG. 1 was obtained. This was annealed at 600 ° C. in the atmosphere for 30 minutes, and then attached on a CuW substrate in the same manner as in Example 1. Refrigerant water (water temperature 25 ° C.) was introduced into the grooves of the grooved diamond / CuW substrate thus prepared. When the thermal resistance between the diamond surface and the coolant was examined, it was 0.012 ° C./W.

Example 7 Vacuum Annealing In the same manner as in Example 1, a grooved diamond as shown in FIG. 1 was obtained. This was annealed at 1200 ° C. in vacuum for 30 minutes. When Raman spectrum measurement was performed on this sample, a peak showing a non-diamond component was observed.
Then, it was stuck on a CuW substrate in the same manner as in Example 1.
Refrigerant water (water temperature 25 ° C.) was introduced into the grooves of the grooved diamond / CuW substrate thus prepared. When the thermal resistance between the diamond surface and the refrigerant was investigated, it was 0.011 ℃ / W
Met.

Example 8 In the same manner as in Example 1, a grooved diamond as shown in FIG. 1 was obtained. This is heated to 100 in hydrogen by μ-wave plasma.
Processed at Torr and temperature of 800 ° C. for 30 minutes. Raman spectrum measurement of this sample was performed. Then, a sharp peak of diamond was observed as shown in FIG. After this,
It was attached on a CuW substrate in the same manner as in Example 1. Refrigerant water (water temperature 25 ° C.) was introduced into the grooves of the grooved diamond / CuW substrate thus prepared. When the thermal resistance between the diamond surface and the cooling medium was examined, it was 0.038 ° C./W.

Example 9 CVD, Laser Flow Path Insertion, Adhesion: Two scratch-treated polycrystalline Si substrates (10 mm × 10 mm × thickness 2 mm) were prepared, and diamond was grown on them by microwave plasma CVD method. It was The growth conditions were 1% methane-hydrogen system, the pressure was 80 Torr, and the substrate temperature was 900 ° C.
After the growth of one sheet for 250 hours and the other for 200 hours, the growth surface was polished and the Si substrate was dissolved with an acid.
mm x 10mm x thickness 0.3mm and 10mm x 10mm
Two free-standing diamond films of x 0.15 mm were obtained. When thermal conductivity was measured, each was 17.2 W / cm · K
(Thickness of 0.3 mm, first freestanding diamond film) and 16.9 W / cmK (thickness of 0.15 mm, second freestanding diamond film).

On one side of the first diamond free-standing film (0.3 mm thick diamond free-standing film) obtained as described above,
Line focusing and point focusing of KrF excimer laser,
To form a groove. The grooves had a depth of about 150 μm, a width of about 500 μm, and an interval of about 400 μm. Ti to both
After stacking Pt and Au by vapor deposition, by melting Au, the first diamond free-standing film was bonded to the second diamond free-standing film to prepare a substrate (FIGS. 5 and 6). Thickness of Ti / Pt / Au / Pt / Ti layer is 0.1
It was μm. Cooling water (water temperature 25 ° C.) was supplied to the flow path of the substrate manufactured as described above. The thermal resistance between the surface of the diamond and the water of the refrigerant was measured and found to be 0.
It was 011 ° C / W.

Example 10 High-pressure synthesis, flow-through laser, attachment: Ib type diamond synthesized under high temperature and high pressure [first diamond freestanding film (8 mm × 8 mm × thickness 0.4 mm, thermal conductivity 18.3 W / cm·
K) and the second diamond free-standing film (8 mm × 8 mm × thickness 0.2 mm, thermal conductivity 18.3 W / cm · K) were used to fabricate a diamond substrate with flow channels in the same manner as in Example 9. However, the flow path formed in the first diamond free-standing film uses an ArF excimer laser and has a depth of about 200 μm and a width of about 350 μm.
m, the interval was about 400 μm, and it was as shown in FIG. The second free-standing diamond film was formed with holes at two locations as point-of-collection of a KrF excimer laser as inlets and outlets for the refrigerant introduced into the flow path. Cooling water (water temperature: 25 ° C.) was supplied to the flow path of the substrate thus manufactured in the same manner as in Example 9. At this time, the thermal resistance between the diamond surface and the coolant water was measured and found to be 0.013 ° C./W.

Comparative Example 1 AlN, with flow path: First AlN free-standing film (10 mm x 10
mm x thickness 0.5 mm, thermal conductivity 1.8-1.9 W / cm
Grooves were formed on one surface of (K) using a KrF excimer laser as in Example 9. The depth of the groove is about 150 μm,
The width was about 500 μm and the spacing was about 400 μm. 1A
The 1N self-supporting film is replaced with the second AlN self-supporting film (10 mm x 10 mm x
A substrate having a flow path was obtained by bonding with a thickness of 0.3 mm and a thermal conductivity of 1.8 to 1.9 W / cmK. Cooling water (water temperature 25 ° C.) was supplied to the flow path of the AlN substrate. At this time, the thermal resistance between the surface of AlN and the cooling water was measured and found to be 0.0
It was 88 ° C / W.

Comparative Example 2 CVD, no flow path: Similar to Example 9, a vapor phase synthetic diamond 10 mm × 10 mm × 0.5 mm self-supporting film (thermal conductivity: 17.2 W)
/ Cm · K) was produced. The thermal resistance between the surface and the air was measured while blowing air at 25 ° C. on one surface thereof, and it was 2.8 ° C./W.

Comparative Example 3 CVD, too thin channel: As in Example 9, the first diamond free-standing film (10 mm × 10 mm × 0.3) was formed by vapor phase synthesis.
mm, thermal conductivity 17.2 W / cm · K) and a second diamond freestanding film (10 mm x 10 mm x 0.15 mm, thermal conductivity 17.2 W / cm · K) were prepared. Grooves were formed on the first free-standing diamond film by linearly focusing light rays using a KrF excimer laser as shown in FIG. The grooves had a depth of about 150 μm, a width of about 10 μm, and a gap of about 990 μm. This grooved first diamond free-standing film was adhered to the second diamond free-standing film to prepare a diamond substrate.
Cooling water (water temperature 25 ° C.) was supplied to the flow path of the diamond substrate. At this time, the thermal resistance between the water of the coolant and the surface of the diamond was measured and found to be 0.32 ° C./W.

Example 11 Air Annealing: In the same manner as in Example 9, a first diamond freestanding film and a second diamond freestanding film were obtained. The first diamond free-standing film was set in an atmospheric furnace, and the temperature was set to 600 ° C for 3
Annealed in air for 0 minutes. Then, the second diamond freestanding film was attached in the same manner as in Example 9 to obtain a diamond substrate. Cooling water (water temperature 25 ° C.) was supplied to the substrate. When the thermal resistance between the diamond surface and the water of the coolant was examined, it was 0.01 ° C./W.

Example 12 Vacuum Annealing: In the same manner as in Example 9, a first diamond freestanding film and a second diamond freestanding film were obtained. The first diamond free-standing film is set in a vacuum furnace,
Annealed in vacuum for 30 minutes. When Raman spectrum measurement was performed on this self-supporting film, a peak showing a non-diamond component was observed as shown in b of FIG. Then, the second diamond freestanding film was attached in the same manner as in Example 9 to obtain a diamond substrate. Cooling water (water temperature 25 ° C.) was supplied to the substrate. When the thermal resistance between the diamond surface and the refrigerant was measured, it was 0.01 ° C./W.

Example 13 Grooving from the side: A scratch-treated polycrystalline Si substrate (4
X4x1mm) is prepared, and hot filament CVD is performed on it.
The diamond was grown by the method. The growth conditions are 2% methane-hydrogen system, the pressure is 100 Torr, and the substrate temperature is 850.
C., the filament was tungsten, and the temperature was 2100.degree. After the growth, the silicon substrate was polished and dissolved in an acid to obtain a 4 × 4 × 0.55 mm self-supporting diamond film. The thermal conductivity was 15.9 W / cm · K. A KrF excimer laser was point-focused from the side surface of the diamond film obtained as described above to form a through hole. The holes had a height of about 250 μm, a width of about 300 μm, and a spacing of about 300 μm. A coolant inlet / outlet is separately provided in the flow path of the substrate manufactured as described above, and cooling water (water temperature 25
C) was supplied. The thermal resistance between the surface of the diamond and the water of the coolant was measured and found to be 0.012 ° C./W.

Example 14 Etching: 10 mm × 10 mm × under the same conditions as in Example 9
A 0.3 mm first free-standing diamond film was obtained. A mask pattern of A1 was formed on this one surface with a line width of about 100 μm and an interval of about 50 μm. This was plasma-etched with a mixed gas of argon and oxygen. The treatment was performed for 3 hours at an oxygen ratio of 20%, a total pressure of 0.05 Torr, and an RF output of 200 W. After the treatment, A1 is dissolved and removed with an acid to a depth of about 5
0 μm, line width of about 50 μm, spacing of about 100 μm with grooves 1st
A free-standing diamond film was obtained. The above-mentioned first diamond free-standing film was prepared as a second diamond free-standing film (10 mm x
10 mm × 0.15 mm), and Ti, Pt, and Au were laminated on both by vapor deposition, and then Au was melted and adhered to form a substrate. Ti / Pt / Au / Pt / Ti
The layer thickness was 1 μm. Cooling water (water temperature 25 ° C.) was supplied to the flow path of the substrate manufactured as described above. When the thermal resistance between the surface of the diamond and the water of the refrigerant was measured, it was 0.021 ° C./W.

Example 15 Two polycrystalline Si base materials (10 × 10 × thickness 2 mm) were prepared, and diamond was grown on them by the μ wave plasma CVD method. A groove having a depth of about 60 μm, a line width of about 100 μm, and a gap of about 200 μm is formed on one of the two Si base materials. The growth conditions were 1% methane-hydrogen system, the pressure was 80 Torr, and the substrate temperature was 900 ° C. When the growth surface was polished and the Si substrate was removed by dissolution, 10 mm x 10 mm
X 0.3 mm (first free-standing film) and 10 mm x 10 mm x 0.1
Two diamond freestanding films of 5 mm (second freestanding film) were obtained. Since the first free-standing film was formed on the Si base material in which grooves were formed, grooves having a depth of 60 μm, a line width of 200 μm, and an interval of 100 μm were formed on the surface. The thermal conductivity of the first free-standing film is 15.9 W / cm ・ K, and that of the second free-standing film is 18.2 W / cm ・
It was K. The above two free-standing films were bonded together in the same manner as in Example 9 to prepare a substrate. Cooling water (water temperature 2
5 ° C.) was supplied. The thermal resistance between the diamond surface and the coolant water was measured and found to be 0.017 ° C./W.

Example 16 Two polycrystalline Si substrates (10 × 10 × thickness 2 mm) were prepared, and diamond was grown on them by the hot filament CVD method. A molybdenum film having a line width of about 100 μm, a gap of about 20 μm and a thickness of about 2 μm is vapor-deposited on the two sheets in the same manner. The growth conditions were the same as in Example 13. When the growth surface was polished and the base material and molybdenum were dissolved and removed with acid, 10 mm x 10 mm x 0.3 mm (first free-standing film) and 1
0 mm × 10 mm × 0.15 mm (second free-standing film) was obtained. Each,
Depth of about 40μm, line width of about 200μm, spacing of about 100
A μm groove was formed. The thermal conductivity of the first free-standing film is 15.2
W / cm · K and the second free-standing film were 16.9 W / cm · K. Similar to Example 9, the two self-supporting films were attached to each other so that the grooves of both films were well aligned with each other to prepare a substrate.
Cooling water (water temperature 25 ° C.) was supplied to the substrate. When the thermal resistance between the diamond surface and the coolant water was measured,
It was 0.018 ° C./W.

Example 17 One piece of polycrystalline Si base material (10 × 10 × thickness 2 mm) was prepared, and diamond was grown thereon by the hot filament CVD method. The growth conditions were the same as in Example 13. After polishing the growth surface and dissolving and removing the base material with acid,
10 mm × 10 mm × 0.15 mm (first self-supporting film) was obtained. After depositing a molybdenum film having a line width of about 100 μm, an interval of about 200 μm and a thickness of about 5 μm on this self-supporting film, diamond film formation was continued under the same conditions. After polishing the growth surface again, molybdenum is dissolved and removed by acid, and the thickness is 450 μm.
The substrate of was obtained. Groove height is about 60μm, line width is about 200μ
m, and the interval was about 100 μm. Cooling water (water temperature 25 ° C.) was supplied to the substrate. When the thermal resistance between the diamond surface and the coolant water was measured, it was 0.02 ° C./W.

[0083]

By using the method for manufacturing a substrate according to the present invention, a substrate having high heat dissipation characteristics can be easily obtained. In particular, when a device having a very large amount of heat generation per unit area, such as a laser chip having a high energy density, which has been difficult to cope with with conventional substrates, is mounted, a great effect can be exerted. Also, by using various substances having high light transmittance as the base material, it is very effective as a method for producing a window material having high thermal conductivity.

[Brief description of drawings]

FIG. 1 is a plan view showing the concept of a grooved high thermal conductivity material layer in the present invention.

FIG. 2 is a side view of a heat dissipation board according to the present invention.

FIG. 3 is a plan view showing the concept of a grooved high thermal conductivity material layer in the present invention.

FIG. 4 is a cross-sectional view showing a groove formed in a high thermal conductive material layer.

FIG. 5 is a plan view of the substrate of the present invention in which the high thermal conductive material surrounds the flow path periphery.

6 is a front view of the substrate of FIG.

FIG. 7 is a plan view of another substrate of the present invention in which the high thermal conductive material surrounds the flow path periphery.

FIG. 8 is a sectional view showing a flow channel formed in the substrate of the present invention.

FIG. 9: Raman spectra of diamond and non-diamond carbon.

[Explanation of symbols]

11, 21 ... High thermal conductivity material layer 12, 22 ... Grooves for passing refrigerant 13 ... Base material 14 ... Refrigerant entrance / exit 15 ... Adhesive layer 16 ... Substrate 111, 121 ... Substrate 112, 122 ... Channels for passing refrigerant 113 ... First high thermal conductivity film 114 ... Second high thermal conductive film 115 ... Adhesive layer 116 ... Refrigerant entrance / exit

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Susumu Ota 1-1-1 Kunyo Kita, Itami City, Hyogo Prefecture Sumitomo Electric Industries, Ltd. Itami Works (72) Inventor Naoji Fujimori Kunyo Kitaichi, Itami City, Hyogo Prefecture 1-1-1, Sumitomo Electric Industries, Ltd. Itami Works (56) Reference JP-A-4-273466 (JP, A) JP-A-5-98443 (JP, A) R.I. Rameshham, Fabrication of Microchannels in Synthetic Polycrystallineline am Thin Thin Films for Heat Sinking App, J. Am. Electroch em. Soc. , June 1991, Volume 138, No. 6, p. 1706-1709 (58) Fields investigated (Int.Cl. ⁷ , DB name) H01L 23/373 H01L 23/473

Claims (13)

(57) [Claims] 1. A step of forming a flow path for a cooling medium to pass through on one surface of a thin plate made of a highly heat-conductive substance having a thermal conductivity of 10 W / cm · K or more by utilizing processing by a laser beam. And b) a method of manufacturing a substrate, including a step of adhering a base material to the processed surface. 2. The method for manufacturing a substrate according to claim 1, wherein the laser beam is an excimer laser beam. 3. The method for manufacturing a substrate according to claim 1, wherein the high thermal conductivity substance is diamond. 4. The method for manufacturing a substrate according to claim 3, wherein the diamond is vapor phase synthetic diamond. 5. The substrate according to claim 1, further comprising a treatment step of improving the wettability of the surface of the flow path for passing the cooling medium with respect to the cooling medium. Production method. 6. A laser beam is applied to one surface of a plate made of a highly heat-conductive material having a thermal conductivity of 10 W / cm · K or more,
The method includes a step of forming a flow path for passing a cooling medium, and a step of adhering another plate made of a high thermal conductive material having a thermal conductivity of 10 W / cm · K or more to the processed surface. A method of manufacturing a substrate, comprising: 7. A step of partially applying a mask to one surface of a thin plate made of a highly heat-conductive substance having a thermal conductivity of 10 W / cm · K or more, and b) selectively applying a maskless part. The method includes: a step of forming a flow path through which a cooling medium passes by etching; c) a step of removing a mask; and d) a step of adhering a substrate to the processed surface. Substrate manufacturing method. 8. The method for manufacturing a substrate according to claim 7 , wherein the base material is a thin plate made of a high thermal conductive material having a thermal conductivity of 10 W / cm · K or more. 9. Claim mask is selectively etched to process a part has not been subjected, characterized by being performed using a plasma of a reaction gas containing oxygen or oxygen 7
The method for manufacturing a substrate according to. 10. A step of forming a groove in a plate-shaped material, a step of growing diamond on the plate-shaped material by a vapor phase synthesis method, a step of removing the plate-shaped material to obtain a grooved diamond self-supporting film, A method of manufacturing a substrate, comprising a step of adhering a base material to a surface having the groove. 11. The method for manufacturing a substrate according to claim 1 0, wherein the substrate is a diamond free-standing film. 12. A method comprising: a step of masking a base material; a step of growing diamond by a vapor phase synthesis method; and a step of removing a mask to obtain a flow path for passing a cooling medium. A method of manufacturing a characteristic substrate. 13. A step of applying a mask to a plate-shaped material, a step of growing diamond by a vapor phase synthesis method, a step of removing the mask and the plate-shaped material to obtain a grooved diamond free-standing film, and a groove of the free-standing film. A method for manufacturing a substrate, comprising the step of adhering a base material to the surface on which the substrate is formed.