JP2000133420A - Heating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heating device which has uniform heating performance and durability, and does not give undesirable influence on an object to be heated. SOLUTION: A heating device 10 includes a block main body 13 comprising an upper block body 11 and a lower block body 12, and a heat conductor 14 is incorporated with the block main body 13. The heating device 10 also includes a heater 15 for heating the block main body 13, and a heat conductive layer 16 is formed on a boundary between the block main body 13 and the heat conductor 14. The metal-containing heat conductive layer 16 which is formed on the boundary between the heat-resistant block main body 13 and the heat conductor 14 improves heat conductivity between the heat-resistant block main body 13 and the heat conductor 16. Therefore, the temperature of the heated heat-resistant block main body 13 is transmitted uniformly to the heat conductor 14, and temperature distribution of the heat-resistant block main body 13 becomes uniform due to the uniformly heated heat conductor, and an object to be heated is heated uniformly.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heating device used for heating means for applying heat to an adhesive for surface mounting parts, heat treatment after bonding, cream solder reflow, or high temperature operation test.

[0002]

2. Description of the Related Art A heating device called a block heater or the like has conventionally been used when performing heat application of an adhesive for a surface mount component, heat treatment after bonding, cream solder reflow or heating for a high-temperature operation test. I have. A conventional block heater has a structure in which a heater serving as a heat source is inserted inside a block body formed of stainless steel or the like having excellent heat resistance. By heating the entire block body with the heater, the block heater is heated. The object brought into contact with the heating surface of the body is heated.

However, in the case of a conventional block heater,
Although the stainless steel forming the block has excellent heat resistance, it has low thermal conductivity, so that when heated by an internal heater, it is difficult to make the temperature distribution on the heating surface of the block uniform. For this reason, the entire object brought into contact with the heating surface cannot be heated uniformly without unevenness, causing various product defects.

Accordingly, the present applicant has developed a block heater excellent in uniform heating properties and disclosed in Japanese Patent Application Laid-Open No. 8-335490. As shown in FIG. 5, this block heater has a structure in which a block body 52 having a heater 51 is embedded with an enclosure 53 for uniform heating having a higher thermal conductivity than the block body 52. A block heater 50 is formed by interposing a heat transfer agent such as thermal grease on the contact surface between the sealing member 53 and the enclosure 53.

[0005] With such a structure, even when the thermal conductivity of the block body 52 formed of a heat-resistant metal is low, the enclosure 53 that has received heat from the heater 51 has a high thermal conductivity. Therefore, it is possible to equalize the amount of heat transferred to the heating surface 50f, and to equalize the temperature distribution of the heating surface 50f.

Therefore, by using the block heater 50, the object to be heated 54 can be uniformly heated, and the same durability as that of the conventional block heater can be maintained.

[0007]

Problems to be Solved by the Invention
In the case of the block heater disclosed in Japanese Patent Publication No. 0, the heat transfer agent such as thermal grease is interposed between the contact surface between the block main body 52 made of a heat-resistant metal and the enclosing body 53, so that the temperature of the heating surface 50f is increased. Although the distribution has been made uniform, the result is insufficient in some respects, and the actual situation is that the temperature distribution of the heating object 54 has some unevenness.

If the temperature distribution of the heating object 54 becomes non-uniform, it causes various product defects. Therefore, it is necessary to perform more complete uniform heating. In addition, with the recent increase in the precision of industrial products, strict process control has been required in the manufacturing process, and the demand for uniform heating properties has been increasing.

In the case of the conventional block heater, the thermal grease interposed on the contact surface between the block main body 52 and the enclosing body 53 may be gradually deteriorated due to long-term use. May be further uneven.

An object of the present invention is to provide a heating apparatus which is excellent in uniform heating property and durability and does not adversely affect an object to be heated.

[0011]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention relates to a heating apparatus including a heat-resistant block body containing a heat conductor and heating means for heating the heat-resistant block body. A heat conductive layer containing a metal is formed at a boundary between the heat resistant block main body and the heat conductor.

With this configuration, the heat conductivity between the heat-resistant block main body and the heat conductor is improved, so that the temperature of the heat-resistant block main body heated by the heating means is reduced by the heat conductor. The heat is transmitted evenly, and the temperature distribution of the heat-resistant block main body is made uniform by the uniformly heated heat conductor. Therefore, the object to be heated that comes into contact with the heat-resistant block main body can be uniformly heated.

Further, in the case of the heating device of the present invention, the heat conductor is built into the heat-resistant block main body, and a heat conductive layer is formed at the boundary between the two. There is no possibility that metal ions or the like are generated from the heat conductor, and the durability is excellent.

As the material of the heat-resistant block body, stainless steel, heat-resistant steel, cast steel, an alloy for electric heating or a corrosion-resistant heat-resistant alloy can be used, but stainless steel is preferable in terms of durability and thermal expansion. It is. Further, as the material of the heat conductor, a material having a higher heat conductivity than the heat-resistant block main body is desirable, and gold, silver, copper, aluminum or the like can be used, but the heat-resistant block main body is made of stainless steel. In this case, copper having a small difference in coefficient of thermal expansion is preferable.

Here, the heat conductive layer can be formed of a brazing material. Thereby, the heat conductive layer becomes excellent in heat conductivity, so that the heat conductive state between the heat-resistant block main body and the heat conductor becomes good, and the temperature distribution of the heat-resistant block main body can be made uniform. it can. In addition, since the brazing material has a lower melting point than the heat-resistant block body and the heat conductor and has good wettability and fluidity, the boundary between the two is filled without gaps,
It is possible to form a heat conductive layer having excellent adhesion.
Furthermore, the brazing material has excellent durability because it undergoes very little deterioration even after a long-term heating operation.

When the heat conductive layer is formed of a brazing material,
After the brazing material is dispersed in the gap between the heat-resistant block main body and the heat conductor, if the heat-resistant block main body is heated, the molten brazing material flows while the gap is formed at the boundary between the heat-resistant block main body and the heat conductor. Thereafter, if the brazing material is cooled below the melting point of the brazing material, the brazing material is hardened and a strong heat conductive layer is formed.

In this case, silver brazing can be used as the brazing material. Since silver braze is an alloy containing silver having high thermal conductivity as a main component and copper, zinc, cadmium, nickel, tin, etc. added thereto, it is possible to form a heat conductive layer having higher thermal conductivity. It is possible, and the temperature distribution can be made uniform at a higher level.

The thickness of the heat conductive layer is set to 0.05 mm to
By setting the thickness to 1 mm, it is possible to obtain a heat conductive layer excellent in a heat conductive state at low cost. When the thickness of the heat conductive layer is less than 0.05 mm, it is difficult to form a layer having no defect, the thermal conductivity becomes insufficient, and when the thickness of the heat conductive layer exceeds 1 mm, uniform Since it is difficult to form a layer having a thickness and the cost increases,
Desirably, it is 1 mm.

Further, a through hole communicating with the heat conductive layer can be provided in the heat conductor. When the heat conductive layer is formed with the brazing material, as described above, the brazing material is dispersed in the gap between the heat-resistant block main body and the heat conductor, and then the brazing material is melted by heating the heat-resistant block main body. However, if the through holes are provided, the gas contained in the gaps and the flux contained in the brazing material are discharged through the through holes, so that the flowability of the molten brazing material is improved and the flux and the like are improved. It is possible to eliminate the residue,
A defect-free heat conductive layer can be formed.

[0020]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a partially cutaway perspective view showing a heating device according to an embodiment, FIG. 2 is a longitudinal sectional view of the heating device, and FIG. 3 is a transverse sectional view of the heating device.

In the heating device 10 of the present embodiment, a heat conductor 14 is incorporated in a block body 13 composed of an upper block body 11 and a lower block body 12, and a heater 15 for heating the block body 13 is provided. A heat conduction layer 16 is formed at a boundary between the block body 13 and the heat conductor 14. The heater 15 is connected to the lower block 1.
2 is inserted into a heater insertion hole 18 formed in the heater 2.

With such a configuration, the thermal conductivity between the block main body 13 and the heat conductor 14 is increased, so that the temperature of the lower block body 12 heated by the heater 15 is reduced by the heat conductor 14. The temperature distribution of the upper block body 11 is made uniform by the heat conductor 14 which is transmitted evenly and is uniformly heated, and the object 17 to be heated placed on the heating surface 11f can be uniformly heated.

In this case, the heat conductor 14 is connected to the block body 1
3, the heat conductive layer 16 is formed at the boundary, so that there is no danger that harmful metal ions or the like are generated from the heat conductor 14 to the object 17 to be heated during the heating operation, and the durability is excellent.

In the heating device 10, the block body 1
Since No. 3 is formed of stainless steel having excellent heat resistance, it does not deteriorate by heating and has good durability. In addition, since the thermal conductor 14 is formed of copper having a relatively large thermal conductivity and a small difference in thermal expansion coefficient from stainless steel, the thermal conductor 14 is effective for uniformizing the temperature distribution of the heating surface 11f, Even if heating and cooling are repeated, the block body 13 and the heat conductor 14 are not separated, and the durability is excellent.

On the other hand, in the heating device 10 of the present embodiment, since the heat conductive layer 16 is formed of a silver solder containing silver having a high heat conductivity as a main component, the block body 13 and the heat conductor 14 The heat conduction between them is extremely good, and the temperature distribution on the heating surface 11f of the upper block body 11 can be made uniform. In addition, since the silver brazing material has a lower melting point than the stainless steel block body 13 and the copper heat conductor 14, has good wettability to both, and has high fluidity,
It is possible to form the heat conductive layer 16 which is filled with no gap at the boundary between the two and has excellent adhesion. In addition, since there is no deterioration due to a long-time heating operation, the durability is good.

Further, the heat conductor 14 has a heat conduction layer 16
And a through-hole 20 communicating with the hole. By providing the through-holes 20, the gas present in the gap between the block body 13 and the heat conductor 14 and the flux contained in the brazing material are discharged through the through-holes 20. As a result, the residual property such as flux can be eliminated, and a heat conductive layer having no defect can be formed.

Here, the manufacturing process of the heating device 10 will be described with reference to FIG. FIG. 4 is an explanatory diagram illustrating a manufacturing process of the heating device 10.

When manufacturing the heating device 10, first, FIG.
(A) As shown in FIG.
Is held with the opening facing upward, and after the silver brazing material 19 is disposed therein, the heat conductor 14 is embedded.

Then, as shown in FIG. 4B, when the upper block body 11 is heated using a heat source 21, the silver brazing material 1 is heated.
9 is melted and flows through the upper block body 11 and the heat conductor 14 to fill the entire boundary without gaps. Thereafter, if the material is cooled to the melting point of the silver brazing material 19 or less,
The silver brazing material 19 is hardened to form a strong heat conductive layer 16.

When the molten silver brazing material 19 flows between the upper block body 11 and the heat conductor 14,
The gas present therein and the flux contained in the silver brazing material 19 are discharged through the through holes 20 provided in the heat conductor 14, so that the flowability of the molten silver brazing material 19 is good. There is no residual flux or the like, and the heat conductive layer 16 without defects can be formed. In the present embodiment, three through holes 20 are provided in the heat conductor 14, but the inner diameter and the number of the through holes are determined according to various conditions such as the size of the heat conductor and the type of the silver brazing material. Can be.

After the brazing material 19 is cured and the heat conductive layer 16 is formed, the lower block body 12 is placed so as to cover the heat conductor 14 as shown in FIG. When the body 11 and the lower block body 12 are joined by welding, as shown in FIG. 4D, the heating device 10 without the heater 15 is completed.

In the present embodiment, when the thickness of the heat conductive layer 16 is set to 0.1 mm, the flowability of the molten silver brazing material 19 is good, and the heat conductive layer 16 is low in cost and has excellent heat conductivity. Layer 16 could be formed. The heat conduction layer 1
The thickness of 6 can be freely determined within the range of 0.05 mm to 1 mm according to the size of the heating device, the heating temperature or the working conditions.

As described above, after the silver brazing material 19 is interposed between the upper block 11 and the heat conductor 14, the heating device 10 forms the heat conductive layer 16 by heating the upper block 11. Therefore, there is no need to employ a special device or process, and the device can be easily manufactured.

[0034]

According to the present invention, the following effects can be obtained.

(1) By forming a heat conductive layer containing a metal at the boundary between the heat resistant block main body and the heat conductor,
Since the thermal conductivity between the heat-resistant block body and the heat conductor is improved, the temperature of the heated heat-resistant block body is transmitted evenly to the heat conductor, and the uniformly heated heat conductor The temperature distribution of the heat-resistant block main body is made uniform, and the object to be heated can be uniformly heated.

(2) By forming the heat conductive layer with a brazing material, the heat conductive layer becomes excellent in heat conductivity, so that the heat conductive state between the heat resistant block main body and the heat conductor is good. Thus, the temperature distribution of the heat-resistant block main body can be made uniform. In addition, since the brazing material has a lower melting point than the heat-resistant block body and the heat conductor, and has good wettability and fluidity, it can be filled without gaps at the boundary between the two to form a heat conductive layer having excellent adhesion. It is possible. In addition, since there is no deterioration due to a long-time heating operation, the durability is improved.

(3) By using a silver brazing material as a brazing material, it is possible to form a heat conductive layer having even higher thermal conductivity, and to achieve a higher level of uniform temperature distribution. .

(4) The thickness of the heat conductive layer is 0.05 mm to
By setting the thickness to 1 mm, it is possible to form a heat conductive layer excellent in a heat conductive state at low cost.

(5) By providing a through hole communicating with the heat conductive layer in the heat conductor, the gas and the flux contained in the brazing material existing in the gap between the heat resistant block main body and the heat conductor are formed in the through hole. As a result, the fluidity of the molten brazing material is improved, and it is possible to eliminate residual flux and the like, and to form a defect-free heat conductive layer.

[Brief description of the drawings]

FIG. 1 is a partially cutaway perspective view showing a heating device according to an embodiment.

FIG. 2 is a longitudinal sectional view of the heating device shown in FIG.

FIG. 3 is a cross-sectional view of the heating device shown in FIG.

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

FIG. 5 is a partially cutaway perspective view showing a conventional heating device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Heating device 11 Upper block body 11f Heating surface 12 Lower block body 13 Block main body 14 Heat conductor 15 Heater 16 Heat conductive layer 17 Heated object 18 Heater insertion hole 19 Silver brazing material 20 Through hole 21 Heat source

Claims (5)

[Claims] 1. A heating apparatus comprising: a heat-resistant block main body in which a heat conductor is built; and a heating means for heating the heat-resistant block main body, wherein a heating unit is provided at a boundary between the heat-resistant block main body and the heat conductor. A heating device comprising a heat conductive layer containing a metal. 2. The heating device according to claim 1, wherein the heat conductive layer is formed of a brazing material. 3. The heating device according to claim 2, wherein said brazing material is silver brazing. 4. The heat conductive layer has a thickness of 0.05 mm or more.
The heating device according to claim 1, which is 1 mm. 5. The heating device according to claim 1, wherein the heat conductor is provided with a through hole communicating with the heat conductive layer.