JP2002075607A - Heating device and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heating device which has a superior thermal efficiency and a small temperature unevenness, and provide its manufacturing method in the heating device wherein metallic body for homogeneous heating is embedded in the inside of a heat-resistant metal block equipped with a heating means. SOLUTION: This is a heating device wherein a metallic body 12 for homogeneous heating, which has a higher thermal conductivity than that of the heat- resistant metal block 11 is embedded inside the heat-resistant metal block equipped with a heating means, and in the state that the metallic body 12 for homogeneous heating is inserted into the inside of the heat-resistant metal block 11, the heating is performed at a temperature not less than the melting point of metallic body 12 for homogeneous heating in the absence of oxygen wherein oxygen does not exist on the inside of the heat-resistant metal block 11, and an inner face of the heat-resistant metal block 11 and an outer face of the metallic body 12 for homogeneous heating are made to be in a tight coupling state.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heating apparatus used for application of heat to an adhesive for surface mounting components in semiconductor manufacturing, heat treatment after bonding or cream solder reflow, and heating for a high temperature operation test, and the like. About the method.

[0002]

2. Description of the Related Art A heating device called a so-called block heater is basically composed of a block made of stainless steel or the like having excellent heat resistance, and a heater serving as a heat source embedded in the block. In this block heater, the temperature of the entire block is raised by a heater, and the heat heats and cures the surface mount component adhesive and the like.

What is particularly important in such a heating apparatus is to precisely and uniformly raise the temperature of the entire heating area. If the heating area of the heating device has unevenness, for example, when it is used for applying heat to the surface mount component adhesive, it causes unevenness in curing of the resin and appears as distortion of the product.
The distortion of the product due to such uneven temperature not only adversely affects the properties of the product, but also causes cracks to be generated from the distorted portion, and in extreme cases, may cause damage to the product.

As a means of solving such problems and obtaining a uniform surface temperature, there is a heating device proposed by the present applicant and disclosed in Japanese Patent Application Laid-Open No. 8-335490. This heating device has a configuration in which an enclosure for uniform heating made of copper or the like having excellent thermal conductivity is embedded in a conventionally used block body made of stainless steel. According to this heating device, it is possible to reduce the thermal resistance of the entire heating device as compared with a device formed only of stainless steel, thereby efficiently transferring the heat of the heater to the heating surface side and thereby increasing the entire heating surface area. A uniform temperature distribution can be obtained.

[0005]

However, in the manufacture of the heating device described in the above-mentioned publication, the joining of the block body and the enclosure for uniform heating is performed by mere mechanical fitting or silver brazing. Have been done. In such mechanical fitting, a gap tends to be formed on the entire boundary between the inner surface of the block main body and the outer surface of the enclosure for uniform heating, and a gap tends to be partially formed in the case of silver brazing.

[0006] Such an entire clearance degrades thermal efficiency,
In addition, partial gaps cause temperature unevenness. In particular, the temperature unevenness becomes more severe as the temperature becomes higher.
In the case of 3 ° C. and 500 ° C., temperature unevenness of ± 7.5 ° C. occurred.

[0007] Therefore, an object of the present invention is to solve the problems of the heating device previously proposed by the present applicant, and to provide a heating device with good thermal efficiency and less temperature unevenness, and a method of manufacturing the same. It is in.

[0008]

The present inventor has conducted intensive studies to solve the above-mentioned problems. As a result, the heat-resistant metal block is used as an outer frame, and the material of the metal body for uniform heating inserted into the outer frame is made of oxygen. Experimentally confirmed that by heating to the melting point under conditions where there is no heat, the inner surface of the heat-resistant metal block and the outer surface of the metal body for uniform heating are completely adhered, thereby improving thermal efficiency and eliminating temperature unevenness. Thus, the present invention has been completed.

That is, the present invention relates to a heating apparatus in which a metal body for uniform heating having a higher thermal conductivity than the heat-resistant metal block is embedded in a heat-resistant metal block provided with a heating means. In a state where the metal body for uniform heating is inserted inside the metal block, the heat-resistant metal body is heated at a temperature equal to or higher than the melting point of the metal body for uniform heating in an oxygen-free state where oxygen does not exist inside the heat-resistant metal block. The inner surface of the block and the outer surface of the metal body for uniform heating are brought into close contact with each other.

Here, as the heat-resistant metal block, stainless steel, Inconel, a nickel-base heat-resistant alloy, a cobalt alloy, or the like having excellent durability can be used. Also,
When an oxidation-resistant coating is applied to the outside of the heat-resistant metal block, a less expensive metal such as iron can be used. It is also possible to use ceramics, which are not metals but have excellent heat resistance and oxidation resistance, without any problem according to the principle of the present invention. As the metal body for uniform heating, it is necessary to use a material having better heat conductivity than the material used for the heat-resistant metal block. In particular, copper, silver,
It is preferable to use aluminum, gold, nickel, or an alloy thereof.

What is important here is that a uniform temperature distribution cannot be realized on the heating surface unless heat is transmitted uniformly as designed inside the heating device. One feature of the heating device of the present invention is to enhance the uniformity on the heating surface by using materials having different thermal conductivities. In the case of using, it is necessary to sufficiently control the production process during production in order to maintain the homogeneity of the bonding interface. The present inventors once melted the material having the lowest melting temperature among the constituent materials in an atmosphere such as vacuum, argon gas, nitrogen gas, inert gas, hydrogen gas, etc. Have been found to be able to be bonded uniformly. When melting in the atmosphere, oxygen in the atmosphere reacts with the constituent material to form an oxide, and when this is present at the bonding interface of the constituent material, the oxide has a thermal conductivity. Because of the badness, the heat conduction inside the heating device became inhomogeneous, and as a result, the heating device had poor heat uniformity. The technology according to the present invention is effective to prevent such a situation.

In order to bring the inner surface of the heat-resistant metal block into close contact with the outer surface of the metal body for uniform heating, it is preferable to melt and join the material having the lowest melting point. In this state, the inner surface of the heat-resistant metal block and the outer surface of the metal body for uniform heating can be brought into close contact with each other by keeping the temperature at which the metal atoms can move for a long time. Usually, the temperature at which metal atoms can move at a realistic speed is said to be a temperature (in absolute temperature) equal to or more than half of the melting point, but how long should the heating actually take place? Whether to join strongly depends on the holding temperature and the pressing pressure, and therefore requires detailed experiments in each case.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The features of the present invention will be described below in detail with reference to the embodiments shown in the drawings.

FIG. 1 is a partially cutaway perspective view showing a heating device according to the first embodiment, and FIG. 2 is a longitudinal sectional view of the heating device shown in FIG.

(Example 1) Heating apparatus 10 of the present embodiment
Is a stainless steel (SUS30) having relatively excellent heat resistance.
4), a heat-resistant metal block 11 made of copper having a higher thermal conductivity than stainless steel inserted into the heat-resistant metal block 11, and a heater 13 as a heat source. ing. The upper surface side in the figure is a heating surface in semiconductor manufacturing or the like.

Next, a manufacturing process of the heating device shown in FIG. 1 will be described with reference to FIGS.

In FIG. 3, reference numerals 11a to 11e denote parts constituting the metal block 11, and these parts 11a
11e are assembled by welding with only the upper surface opened, and a copper plate G as a material of the uniform heating block 12 is inserted therein. At this time, the dimension in the height direction is set to be longer by about 10 mm, assuming that the upper surface is lowered by filling gaps between the parts 11a to 11e and the copper plate G by melting the copper plate G.

In this state, the electric furnace 50 is put into an electric furnace 50 as shown in FIG. Electric furnace 50
Has a divided heater 50 divided into a bottom surface and a side surface.
a to 50e, which are independently temperature-controlled. In order to perform the heat treatment in an atmosphere in which oxygen does not exist, the electric furnace 50 is stored in an iron vacuum container, and the electric furnace is operated while keeping the inside at a vacuum of 1 torr using a vacuum pump. Was. The copper plate G was kept at 1090 ° C. for 1 hour to melt it, and then cooled to room temperature.

Thereafter, the upper surface is cut to a predetermined size by cutting about 10 mm, and as shown in FIG. 5, the cut surface is covered with a metal block part 11f and welded to complete a hexahedron. Further, thereafter, a hole (not shown) is formed for the heater 13, and the heater 13 shown in FIGS.

In order to evaluate the performance of the heating device 10 manufactured as described above, a heating test was performed by attaching thermocouples at 100 locations on the heating surface. The average temperature of the heated surface is 600 ° C ±
With the temperature controlled at 0.5 ° C, the temperature of all the parts with thermocouples was measured. The highest part temperature was 601 ° C and the lowest part temperature was 599 ° C. Turned out to be very good.

(Comparative Example 1) In order to confirm the effect of the heating apparatus of this embodiment, a heating apparatus similar to that of Example 1 was manufactured by a conventional silver brazing method, and a heating test similar to that of Example 1 was performed. went. The temperature of the highest part was 615 ° C., and the temperature of the lowest part was 590 ° C., indicating that the uniformity of the heated surface was very poor.

(Comparative Example 2) In order to confirm the effect of the heating device of the present embodiment, a heating device similar to that of Example 1 was manufactured by the same method as that of Example 1. However, copper plate G
In order to carry out the step of melting in the air, the inside of the iron vacuum vessel was heated to 1090 ° C. without operating the vacuum pump while the inside was filled with air.

The same heating test as in Example 1 was performed. 612 ° C. at the highest temperature, 59 at the lowest temperature
It was 3 ° C., indicating that the uniformity of the heated surface was poor.

From the above, it can be seen from Example 1 and Comparative Examples 1 and 2 that the heating device of the present invention has much better heat uniformity than the prior art.

Example 2 A heating device similar to that of Example 1 was manufactured in the same manner as in Example 1. However, the stainless steel pipe 14 and the valves 15a, 15
11 g of a stainless steel plate to which b was attached was attached. FIG.
In the figure, 15a is a valve for opening and closing a pipe 14 for connecting the inside of the heat-resistant metal block 11 to the gas cylinder, and 15b is a valve for opening and closing the pipe 14 connecting the inside of the heat-resistant metal block and the vacuum pump. It is a valve. Before performing the heat treatment for melting the copper plate G, the valve 1
While the valve 5a is closed and the valve 15b is opened, the inside of the heat resistant metal block 11 is evacuated to a vacuum of 1 torr by a vacuum pump, and then the valve 15b is closed to keep the inside vacuum. In this state, the whole was put in the electric furnace 50 and the electric furnace was operated.

In order to evaluate the performance of the heating device 10 thus manufactured, a heating test was performed by attaching thermocouples to 100 locations on the heating surface. The average temperature of the heated surface is 600 ° C ±
With the temperature controlled at 0.5 ° C, the temperature of all the parts with thermocouples was measured. The temperature of the highest part was 601 ° C and the temperature of the lowest part was 599 ° C. It turned out to be very good.

Example 3 A heating device similar to that of Example 2 was manufactured in the same manner as in Example 2. However, before performing the heat treatment for melting the copper plate G, the valve 15a in FIG.
Is closed and the valve 15b is opened, the inside of the metal block 11 is evacuated to a vacuum state of 1 torr by a vacuum pump, then the valve 15b is closed, the valve 15a is opened and 99.99% argon gas is supplied inside. Pressure 16
After introducing until the pressure reaches 6 torr, the valve 15a is closed, and the inside of the heat-resistant metal block 11 is 166 torr at room temperature.
The entire furnace was filled with an electric furnace 5 while being filled with rr argon gas.
The electric furnace was operated within 0.

In order to evaluate the performance of the heating device 10 thus manufactured, a heating test was performed by attaching a thermocouple to 100 points on the heating surface. The average temperature of the heated surface is 600 ° C ±
With the temperature controlled at 0.5 ° C, the temperature of all the parts with thermocouples was measured. The temperature of the highest part was 601 ° C and the temperature of the lowest part was 599 ° C. It turned out to be very good.

Example 4 A heating device similar to that of Example 3 was manufactured in the same manner as in Example 3. However, as a gas to be introduced, a gas obtained by mixing 99.9% of nitrogen gas, 99% of helium gas, 99% of neon gas, 99% of hydrogen gas, and 4% of hydrogen in argon was used.

The heat uniformity of the heated surface was evaluated in the same manner as in Example 3. However, in the heating apparatus manufactured using any of the gases, the average temperature of the heated surface was controlled at 600 ° C. ± 0.5 ° C. And the temperature of all parts is 601 ° C. to 59
The temperature was within the range of 9 ° C., and it was found that the uniformity of the heated surface was very good.

Example 5 A heating device similar to that of Example 4 was manufactured in the same manner as in Example 4. However, in joining the copper plate G and the metal block 11, not taken method by heating above the melting point of copper to melt the copper, such as copper and the metal block 11 is in contact with 500 g / cm ² or more pressure Bonding was performed by maintaining the state at 1000 ° C. for 10 hours.

The heat uniformity of the heating surface was evaluated in the same manner as in Example 4. However, in the heating apparatus manufactured using any of the gases, the average temperature of the heating surface was controlled to 600 ° C. ± 0.5 ° C. And the temperature of all parts is 604 ° C. to 59
It was within the range of 7 ° C., and it was found that the uniformity of the heated surface was better than that of the comparative example.

As described above, it has been found that in the step of melting the copper plate G and joining it to the metal block 11, it is very effective to perform the heat treatment without oxygen.

According to the heating device of the present embodiment, a heating device having a relatively simple structure, good thermal efficiency, and low temperature unevenness can be obtained.

Example 6 A heating device similar to that of Example 4 was manufactured in the same manner as in Example 4. However, as the material of the metal block 11, SUS310, SUS316, Inconel, nickel-based heat-resistant alloy, and cobalt alloy are used.
Copper, silver, gold, and nickel were used as the metal body for uniform heating. Regarding the heating device manufactured using any material and the heating device joined using any gas, the heat uniformity of the heated surface was evaluated in the same manner as in Example 4. The temperature of all portions was within the range of 602 ° C. to 598 ° C. in a state where the temperature was controlled at ± 0.5 ° C., indicating that the uniformity of the heated surface was better than that of the comparative example.

[0036]

According to the present invention, it is possible to obtain a heating device having a relatively simple structure, good thermal efficiency, and low temperature unevenness.
Further, since each member has been subjected to the heat treatment, the residual stress is reduced to zero, so that stable performance can be maintained with less occurrence of thermal strain during use.

[Brief description of the drawings]

FIG. 1 is a partially cutaway perspective view showing a heating device according to a first embodiment of the present invention.

FIG. 2 is a vertical cross-sectional view of the heating device shown in FIG.

FIGS. 3A and 3B are explanatory views showing a manufacturing process of the heating device shown in FIG. 1, wherein FIG.

FIG. 4 is an explanatory diagram showing a manufacturing process of the heating device shown in FIG.

FIG. 5 is an explanatory diagram showing a manufacturing process of the heating device shown in FIG.

FIG. 6 is an explanatory diagram showing a manufacturing process of the heating device shown in FIG.

[Explanation of symbols]

Reference Signs List 10 heating device 11 heat-resistant metal block 11a, 11b, 11c, 11d, 11e, 11f, 1
1g Parts 12 Metal body for uniform heating 13 Heater 14 Stainless steel pipe 15a, 15b Valve 50 Electric furnace 50a, 50Bb, 50c, 50d, 50e Split heater 51 Cover G Copper plate

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3K034 AA14 BB02 BB14 BC01 BC17 BC29 FA13 FA16 FA17 HA01 HA10 JA01 3K092 PP09 QA07 QB24 RA01 RF03 RF09 RF18 RF27 SS12 SS13 SS14 UB01 UB03 UB04 VV03 VV22 5F044 PP19

Claims (7)

[Claims] 1. A heating device comprising a plurality of types of constituent materials having different thermal conductivities, wherein a heating element capable of generating heat by receiving supply of energy from the outside is provided inside the heating device. It is manufactured through a heat joining process of joining all or a part of the constituent materials by heating to a temperature equal to or higher than the melting point of the constituent material having the lowest melting point among the constituent materials. A heating device which is performed in an oxygen-free state in the absence of oxygen. 2. A heating apparatus in which a metal body for uniform heating having a higher thermal conductivity than the heat-resistant metal block is embedded in a heat-resistant metal block provided with a heating means, wherein the heat-resistant metal block has In a state where oxygen is not present inside the heat-resistant metal block in a state where the metal body for uniform heating is inserted, the metal body for uniform heating is heated at a temperature equal to or higher than a melting point in an oxygen-free state, and is uniformly heated with the inner surface of the heat-resistant metal block. Heating device in which the outer surface of the metal body is in close contact. 3. A heating device in which a metal body for uniform heating having a higher thermal conductivity than the heat-resistant metal block is embedded inside a heat-resistant metal block provided with a heating means, wherein the heat-resistant metal block has With the metal body for uniform heating inserted, the inner surface of the heat-resistant metal block and the outer surface of the metal body for uniform heating are brought into strong contact so that the metal body for uniform heating has a melting point of 1 in an oxygen-free state in the absence of oxygen. A heating device that heats at a temperature of at least / 2 and makes the inner surface of the heat-resistant metal block and the outer surface of the metal body for uniform heating adhere to each other. 4. A method of manufacturing a heating device manufactured using a plurality of materials, comprising a step of heating at least once in an oxygen-free state in a process of manufacturing the heating device. Device manufacturing method. 5. The method according to claim 4, wherein the oxygen-free state is a vacuum state of less than 1 atm. 6. The method according to claim 4, wherein the oxygen-free state is a gas containing no oxygen. 7. The method according to claim 4, wherein the oxygen-free state is a reducing gas.