JPH02164775A - Production of cubic boron nitride sintered body - Google Patents

Abstract

PURPOSE:To provide heat sinks having high dimensional accuracy in large quantities at a low cost by cutting grooves in the surface of a pyrolytic BN molded body when this molded body is treated at high temp. and pressure to produce the subject sintered body. CONSTITUTION:Grooves 2 are cut in the surface of a pyrolytic BN molded body 1, e.g., with a diamond grindstone. Since the molded body 1 is made of soft ceramic, it can easily be subjected to machining such as cutting or polishing. The molded body 1 having the grooves 2 is treated at high temp. and pressure to obtain a cubic BN sintered body. When the molded body 1 is treated at high temp. and pressure after the grooves 2 are filled with a metal having >=1,500 deg.C m.p. such as Mo or Ta, the sides of the grooves 2 can be prevented from sticking to each other during the treatment at high temp. and pressure.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for manufacturing cubic nitrided 5X (OBN) sintered bodies. The cBN sintered body is used not only for semiconductor lasers but also for heat sinks for heat dissipation in IC1 microphone 0-wave devices and the like.

[Conventional technology]

Heat generating individual semiconductor elements such as semiconductor radars are attached to the base of the package via a heat sink to prevent the element performance from deteriorating or running out of control due to the heat generated. As the heat sink material, a cubic boron nitride (cBN) sintered body, etc., which is electrically insulating and highly thermally conductive, is suitable. cB
As a method for manufacturing the N sintered body, for example, pyrolysis capping + t5X manufactured by chemical vapor deposition method (OVD method) is used.
There is a method of treating a (p-BN) molded body under high temperature and high pressure (Japanese Patent Publication No. 63-394). The cEN sintered body produced by this method has the shape of a disc with a diameter of several tens of nanometers, depending on the size of the high-temperature/ultra-high pressure generator used, and can be cut, polished, etc. It is processed into the shape of a heat sink. Conventionally, a radar or diamond grindstone has been used to cut cBN sintered bodies. However, all of these methods have problems. First, cutting by radar has a problem in that the heat generated during radar irradiation lowers the crystallinity of the cBN around the circumference of the cut location, resulting in a reduction in the thermal conductivity of the heat sink. On the other hand, when cutting with a diamond grindstone, highly accurate cutting is possible, but since cBN has the second highest hardness after Diamond V, there is a problem that the amount of wear of the diamond grindstone is large and productivity is low.

[Problem to be solved by the invention]

The present invention aims to improve the above-mentioned problems in cutting technology when using a cBN sintered body as a heat sink, and aims to provide heat sinks with high thermal conductivity and high dimensional accuracy in large quantities and at low cost. That is.

[Means to solve the problem]

That is, the present invention provides cubic nitride fi
This is a method for manufacturing a five-component sintered body.

1. A method for producing a cubic nitrided borax filler body, which comprises forming grooves on the surface of a thermally scaled nitrided unformed body and then subjecting it to high-temperature and high-pressure treatment. .

2. The method for manufacturing a cubic nitrided borage feeder body according to claim 1, wherein the groove is filled with a metal having a melting point of 1500° C. or higher.

The present invention will be explained in more detail below.

The P-BN molded body, which is the raw material for the cBN sintered body of the present invention, is
Those manufactured by chemical vapor deposition (OVD) are used. That is, for example, U.S. Pat. No. 315,200
As disclosed in Specification No. 6, boron trichloride (B
Cl2), etc., is prepared using boron gas and ammonia gas as raw materials, and under reduced pressure of 5 Q Torr or less at 1,400 m
Those produced by depositing boron nitride from the gas phase on the surface of a substrate such as graphite at a temperature of ~2300°C are used.

Unlike the aBN sintered body, the P-BN molded body is made of soft ceramic, and therefore machining such as cutting and polishing can be easily performed.

Therefore, grooves can be formed on the P-BN surface using, for example, a diamond grindstone. The width of the groove is determined by the thickness of the diamond grinding wheel used, and is usually 0.01 to 0. It is a number dragon. Furthermore, the depth of the grooves is freely determined by the depth of cut of the Diamond P grindstone, and furthermore, the distance between the grooves is determined according to the required dimensions of the heat sink.

An example of this is shown in FIG.

The P-BN molded body provided with grooves as described above is ((
), (b), etc., high temperature and high pressure treatment is performed. For high-temperature and high-pressure processing, a high-temperature and ultra-high pressure generating device such as a belt-type device is used.

fl), directly treated under high temperature and high pressure. (Temperature: 1800
℃ or higher, preferably 2100-2500℃, pressure crab 6
Q kbar or more, preferably 651 cbar or more; JP-A-54-3510) (b) After diffusion impregnation with a catalyst such as Mg5BN3, high temperature and high pressure treatment (temperature: 130 cbar or more)
0°C or higher, pressure 40,000 atmospheres or higher). (Unexamined Japanese Patent Publication 1986-
108772) That is, according to the method according to claim 1 of the present invention, the P-BN molded body provided with the grooves can be used as is or with Mg5B.
After being diffused and impregnated with a catalyst such as IJ3, it is filled into a container for high temperature and high pressure treatment. On the other hand, according to the method according to claim 2, the grooves of the P-BN molded body provided with the neck are filled with metal as it is or after being diffused and impregnated with a catalyst such as Mg5BN3, and then the grooves are filled with metal. It is filled into a container for high-temperature and high-pressure processing. Suitable metals to be used at this time include molybdenum (MO), tantalum (Ta), and the like, which have melting points of 1500° C. or higher because the high temperature and high pressure treatment temperature is high. By filling the groove with metal, it is possible to prevent the wall surfaces of the groove from adhering to each other during high temperature and high pressure treatment.

The P-BN molded body filled in a container for high temperature and high pressure treatment is converted into a cBN sintered body by high temperature and high pressure treatment.

The produced cBN sintered body is treated with raw material P- before high-temperature and high-pressure treatment.
The grooves provided in the BN molded body remain. If the surface of the cBN sintered body is polished and then cut with a radar or diamond grindstone at the groove position, the depth of cut required for cutting is reduced by the depth of the groove. Therefore, first of all, with laser cutting, the laser energy and time required for cutting are significantly reduced compared to conventional methods, which reduces the thermal conductivity of the heat sink due to the low crystallinity of cBN around the cutting point, which has been a problem in the past. Not only can you prevent the decline, but also
Productivity can be increased. Furthermore, even when cutting with a diamond grindstone, the amount of wear of the grindstone and the time required for cutting are significantly reduced compared to conventional methods, so productivity can be increased. Therefore, by the method of the present invention, heat sinks made of high quality cubic nitrided borosilicate heat sinks can be manufactured in large quantities.

〔Example〕

Hereinafter, the present invention will be explained in more detail with reference to Examples and Comparative Examples.

Example 1, Comparative Example 1 A disc with a diameter of 20 mm and a thickness of L 2 mm was prepared from a commercially available P-BN molded body, and a diamond grindstone was used on one of the wide sides of the disc to obtain a width of 0.1 mm and a depth of 0. .6sn groove 11I
After digging in a grid pattern at 11 intervals, it was buried in MgaN2 powder and kept at 1200°C in a nitrogen stream for 12 hours.
s 0.8 mol% was diffused and contained. Using this as a raw material, a belt-type high-temperature, high-pressure device is used to process the product at a temperature of 1600°C and a pressure of 6.
A sintered body was obtained by maintaining the pressure under conditions of 60 minutes. When the obtained sintered body was identified by X-ray diffraction, it was confirmed that it was cBN, and the lattice-shaped grooves remained as they were. After polishing both wide surfaces, the blade thickness is 0.2s along this groove.
The sintered body was cut using a diamond grindstone of 0.8
A square plate-shaped piece of mx X O-8vIX O, 6xm was obtained.

At this time, the amount of wear in the radial direction of the grindstone is 0.0% per square plate.
01 It is a dragon, and the time required to cut it is 6 per square plate.
It was 0 seconds.

For comparison, a cBN sintered body was manufactured and cut under the same conditions as in the example without providing a groove in the P-BN molded body. As a result, the amount of wear in the radial direction of the grinding wheel was 0.1i per square plate.
n, and the time to simulate cutting was 100 seconds per square plate.

Example 2, Comparative Example 2 A disc with a diameter of 12 mm and a thickness of 1 dragon was produced from a commercially available P-BN molded body, and a diamond grindstone was used on one of the wide sides of the disc, and a width of 0.1 m and a depth of 0.1 m were prepared. Grooves of 0.5n were dug in a grid pattern with a total interval of 1.2 squares. Using this as a raw material, it was heated in a belt-type high-temperature, high-pressure device at a temperature of 2,000℃ and a pressure cuff under the conditions of 60 degrees of pressure.
A sintered body was obtained by holding for 0 minutes. When the obtained sintered body was identified by X-ray diffraction, it was confirmed to be cBN, and the lattice-shaped grooves remained as they were. After polishing both wide surfaces, the sintered body was cut into the groove using a diamond grindstone with a blade thickness of 0.2 nm.
A square plate-shaped piece of 6yx* was obtained. At this time, the amount of wear of the grindstone in the radial direction was 0.02 mm per square plate, and the time required for cutting was 40 seconds per square plate.

For comparison, a cBN sintered body was manufactured and cut under the same conditions as the example without digging a groove in the P-BN molded body. As a result, the amount of wear in the radial direction of the grinding wheel was 0.1411 per square plate.
3N, and the time required for cutting is 180N per square plate.
It was seconds.

Example 3 A disk with a diameter of 25 mm and a thickness of 1.2 mm was prepared from a commercially available P-BN molded body, and a diamond grindstone was used on one of the wide sides of the disk to form a disk with a width of 0.2 t and a depth of 0.2 mm. 6111 groove to 0.
After digging in a grid pattern at 9s1111 intervals, it was buried in MgsNg powder and kept at 1200°C for 12 hours in a nitrogen stream.
8 mol % of sBNs O was diffused into the sample. 0,8 yx* X O, consisting of MO wire with one side diameter 0.2 mm
A wire mesh having a mesh size of 8trII was arranged so that the MO wires filled the lattice-shaped grooves of the P-BN molded body. For one P-BN disk, two wire meshes 1r were stacked and used.

Using this as a raw material, a belt-type high-temperature pressure device is used to process the product at a temperature of 15%.
A sintered body was obtained by maintaining the temperature at 50° C. and a pressure of 52,000 atmospheres for 20 minutes. This sintered body was confirmed to be aBN by X-ray diffraction. Furthermore, the lattice-shaped grooves filled with MO remained in the obtained sintered body. This MO could be easily removed by soaking the sintered body in hot aqua regia. After polishing both wide surfaces of the sintered body, the blade thickness is 0 along this groove.
．． The sintered body was cut using a two-way diamond grindstone, and
．． Square plate-shaped pieces of 7 mm x O, 7 mm x O, and 6 mm were obtained.

At this time, the amount of wear in the radial direction of the grindstone is 0.0% per square plate.
00511, and the time required for cutting was 10 seconds per square plate.

Example 4, Comparative Example 6 Using boron trichloride and ammonia as raw material gases, pressure: 3 Torr%, temperature: 1940°C, vapor deposition speed: 100μ
P-BN of 1.2sn thickness was thermally decomposed as m/hr.
A plate was deposited. Diameter 121R1L from this P-BN plate
1. Fabricate a disk with a thickness of 0.8 mm, and use a diamond grindstone to cut a groove of @0.1 m and a depth of 0.4 mm on one of the wide sides.
．． After digging in a lattice pattern at 1-h intervals, it was embedded in Mg and N2 powder and kept at 1250°C for 5 hours in a nitrogen stream.
0.7 mol % of aBNs was diffusely included. This is used as raw material in a belt-type device at a temperature of 1,600°C and a pressure of 50,000 yen.
A sintered body was obtained by holding it under 1,000 atmospheres for 60 minutes. It was confirmed by Xi diffraction that this sintered body was cBN. In addition, the lattice-shaped grooves remained in the obtained sintered body.

For comparison, a cBN sintered body was manufactured under the same conditions as in the example without digging a groove in the raw material P-BN plate. After polishing both wide surfaces of these sintered bodies, Y
Cut with A() radar, 1 mm x 1 mm x 0
A square plate-shaped piece of -3 mm was obtained.

cBN of the cut surface based on the average output of the radar, the time required to cut one square plate, and the peak width of the microscopic Raman spectroscopic analysis
The crystallinity of was measured. The results are shown in Table 1.

Example 5, Comparative Example 4 The cBN sintered rectangular plates of Example 4 and Comparative Example 6 were first coated with Ni f 5 [10AN and then gold tsooX by sputtering for metallization to form heat sinks. A semi-integrated fiber was soldered onto this heat sink and connected to the heat sink. A t current of 20'OmA was applied to this semi-integrated radar, and the surface temperature of the element was measured. As a result, it was found that the surface temperature of the element in the heat sink using the sintered body of Example 4 was about 10° C. lower than that in the heat sink using the fiM body of Comparative Example 6.

〔Effect of the invention〕

According to the method for producing a cBN sintered body of the present invention, it is possible not only to reduce the time and power required for cutting the sintered body, but also to increase the life of the cutting tool. Furthermore, cBN around the cut surface when cutting with a laser
Since deterioration of the sintered body can be prevented, cEN sintered bodies for use in heat sinks and the like can be manufactured at low cost and in large quantities.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a pyrolyzable borosilicate (P-BN) molded article in which grooves are provided in a lattice pattern in a direction perpendicular to the surface. 1: P-BN molded body, 2: Groove Figure 1 1... P-BN molded body 2... Groove Patent applicant Denki Kagaku Kogyo Co., Ltd. Procedural dispute book (4) Table on page 12 of the specification 1Rightmost row, top row 'cBM'
cBN”. February 23, 1989■, Display of case, 1986 Patent Application No. 318574 2, Name of invention, Method for manufacturing cubic nitrided borage feeder body 3, Person making amendment Relationship with case Address of patent applicant 0100 1-4-1 Yurakucho, Chiyoda-ku, Tokyo
No. 5゜ Contents of amendment in the Detailed Description of the Invention column of the specification (1) Correction to "J provided in page 4, line 18 of the specification. (2) Correction to "J provided in page 5, line 11 of the specification. Corrected to ``It was established.''``established'' means ``established''

Claims (2)

[Claims] 1. A method for producing a cubic boron nitride sintered body, which comprises forming grooves on the surface of a pyrolytic boron nitride molded body and then subjecting it to high temperature and high pressure treatment. 2. 2. The method of manufacturing a cubic boron nitride sintered body according to claim 1, wherein the groove is filled with a metal having a melting point of 1500° C. or higher.