JP2000133428A - 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 heat resistant block body 12 having a heating surface 12f for mounting an object to be heated 11 and a heater 13 of a spiral shape laid on a lower surface 12u of the heat resistant block body 12. A heat conductive layer 14 is formed on a boundary between the lower surface 12u of the heat resistant block body 12 and the heater 13 and the whole lower surface 12u. Since the metal containing heat conductive layer 14 is interposed on the boundary between the heater 13 and the heat resistant block body 12, the heat conductivity between the heater 13 and the heat resistant block body 12 improves and the heat from the heater 13 efficiently transmits to the heat resistant block body 12 through the heat conductive layer 14. Thus, temperature distribution in the heat resistant block body 12 becomes uniform and the 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 applying heat to an adhesive for surface mounting components, heat treatment after bonding, cream solder reflow, or heating for a high-temperature operation test, and more particularly to a spiral heater. And a heating device comprising:

[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.

As shown in FIG. 5, a conventional block heater 55 is designed to prevent deterioration due to repeated heating and cooling.
A spiral heater 51 serving as a heat source is attached to the lower surface of a block body 50 made of stainless steel or the like having excellent heat resistance.
This is a structure that covers the entire attachment surface.

[0004] By energizing the heater 51 to generate heat, the entire block body 50 is heated, and the heat heats the object 53 placed on the heating surface 50f of the block body 50.

[0005]

In the case of the conventional block heater 55, the stainless steel forming the block body 50 is excellent in heat resistance, but has a low thermal conductivity. Is likely to be lower than in the vicinity of the heater 51, and it is difficult to make the temperature distribution on the heating surface 50f uniform. For this reason, the heating surface 50
In some cases, the object 53 to be heated placed on the substrate f cannot be heated uniformly, resulting in a product defect due to an uneven temperature distribution.

In order to solve such a problem, it is sufficient to form the block body 50 using gold, silver, copper, or the like having high thermal conductivity. Since copper is easily adopted, it is liable to rapidly deteriorate due to oxidation during heating and abrasion due to contact, and so cannot be used as a material for a block body in practice.

Further, when the block body 50 is formed of copper, a product to be heated may be adversely affected by copper ions generated at the time of heating. Is unsuitable for

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.

[0009]

In order to solve the above-mentioned problems, the present invention comprises a heat-resistant block on which an object to be heated can be placed, and a heater attached to the lower surface of the heat-resistant block. In the heating device, a heat conductive layer containing a metal is interposed at a boundary between the heater and the heat-resistant block.

With such a configuration, the heat conductivity between the heater and the heat-resistant block is improved, and the heat of the heater is efficiently transmitted to the heat-resistant block via the heat conductive layer. Therefore, the temperature distribution of the heat-resistant block body is made uniform, and the object to be heated can be uniformly heated.

This eliminates the need to form the heat-resistant block body with copper or the like, thereby eliminating the risk of oxidation and abrasion during heating, resulting in excellent durability, and having copper ions adversely affecting the object to be heated. I do not give.
In addition, as a material for forming 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, and stainless steel is preferable in terms of durability and thermal expansion properties. It is.

Further, the heat conductive layer can be formed also on the lower surface of the heat-resistant block provided with the heater.
A heat conductive layer is formed not only on the boundary between the heater and the heat-resistant block, but also on the lower surface of the heat-resistant block provided with the heater, so that the heat of the heater is heat-resistant through the heat conductive layer. Since the heat is efficiently transmitted to the entire lower surface of the heat-resistant block, the temperature distribution of the heat-resistant block is further uniformed, and the uniform heating property of the object to be heated is improved.

Further, the heat conductive layer can be formed of a brazing material. By forming the heat conductive layer with a brazing material, the heater and the heat-resistant block body are firmly joined and the heat conduction state between the two is improved, so that the temperature distribution of the heat-resistant block body is uniform. Become. In addition, since the brazing material has a lower melting point than the heat-resistant block body and the heater, and has good wettability and fluidity, the brazing material spreads without gaps at the boundary between the two and the surface provided with the heater, and a heat conductive layer having excellent adhesion is provided. It is possible to form. In addition, the brazing material has very little deterioration even if it is heated for a long period of time, and therefore has good durability.

When the heat conductive layer is formed of a brazing material,
The lower surface of the heat-resistant block, which is the surface to which the heater is attached, faces up. After placing the heater on this surface, the brazing material is dispersed and heated, and the molten heat-resistant block is heated. Since it spreads without gaps at the boundary between the heat-resistant block and the heater while it flows, there is no gap.If it is cooled below the melting point of the brazing material, the brazing material will harden and form a strong heat conductive layer. Can be.

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.

Further, by setting the thickness of the thinnest portion of the heat conductive layer to 0.1 mm to 2 mm, it is possible to obtain a heat conductive layer having a good heat conductive state at low cost. In addition,
When the thickness at the thinnest portion of the heat conductive layer is less than 0.1 mm, it is difficult to form a layer without defects, the heat conductivity becomes insufficient, and the thickness at the thinnest portion of the heat conductive layer is 2 m.
m, the cost increases.
m is desirable.

[0017]

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

As shown in FIGS. 1 and 2, a heating apparatus 10 according to the present embodiment includes a heat-resistant block 12 having a heating surface 12f on which an object to be heated 11 can be placed, and a heat-resistant block 12 having a heating surface 12f.
And a helical heater 13 attached to the lower surface 12u of the heat-resistant block body 12. The heat conductive layer 1 is formed on the boundary between the lower surface 12u of the heat-resistant block 12 and the heater 13 and the entire lower surface 12u.
4 are formed.

With this configuration, the heat conductivity between the heater 13 and the heat-resistant block 12 is improved, and the heat of the heater 13 is transferred to the heat-resistant block 12 via the heat conductive layer 14. To be transmitted efficiently,
The temperature distribution on the heating surface 12f of the heat-resistant block body 12 is made uniform, and the object to be heated 11 can be uniformly heated.

In the heating device of the present embodiment, since the heat-resistant block 12 is formed of stainless steel, there is no danger of oxidation or abrasion during heating and the durability is excellent, and copper ions are not generated. Therefore, there is no adverse effect on the object to be heated 11.

As shown in FIG. 3, in the heating device 10, the heat conductive layer 14 is also formed on the entire lower surface 12u of the heat-resistant block body 12 provided with the heater 13. Is efficiently transmitted to the entire lower surface 12u of the heat-resistant block 12 via the heat conductive layer 14, so that the heating surface 12f of the heat-resistant block 12
Is uniform, and the object to be heated 11 can be uniformly heated.

Further, in the heating device 10 of the present embodiment,
The heat conductive layer 14 is made of a silver solder containing silver having high heat conductivity as a main component.
Is formed, the heater 13 is firmly joined to the lower surface 12u of the heat-resistant block 12 and the heat conduction state between the two is maintained well. Temperature distribution becomes uniform,
The temperature distribution at a higher level can be made uniform.

Further, the silver brazing material has a lower melting point than the heat-resistant block 12 and the heater 13 and has good wettability and fluidity.
Thermal conductive layer 1 that spreads over the entire 2u without gaps and has excellent adhesion
4 can be formed. In addition, the silver braze has very little deterioration even after a long-time heating operation, and thus has good durability.

In the heating device 10, when the thickness 14t at the thinnest portion of the heat conductive layer 14 was set to 0.1 mm, the heat conductive layer 14 having a good heat conductive state at low cost could be obtained. Note that the thickness of the heat conductive layer 14 at the thinnest portion is 1
4t can be set to an appropriate value according to various conditions such as the diameter of the wire constituting the heater 13 and the size of the heat-resistant block 12.

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

When manufacturing the heating device 10, FIG.
As shown in FIG. 2, the lower surface 12u of the heat-resistant block body 12, which is the surface on which the heater 13 is attached, faces upward.
After the heater 13 is mounted on u, the silver brazing material 15 is dispersed. Next, as shown in FIG. 4B, when the heat-resistant block body 12 is heated from the heating surface 12 side using the heat source 16, the molten silver brazing material 15 flows and the heat-resistant block body 12 and the heater are heated. 13 and lower surface 12u
Spread throughout. When the silver brazing material 15 spreads over the entire lower surface 12u of the heat-resistant block body 12 without any gap, if the silver brazing material 15 is cooled to the melting point or less of the silver brazing material 15, the silver brazing material 15 hardens as shown in FIG. A strong heat conductive layer 14 can be formed.

As described above, the heating device 10 arranges the heater 13 and the silver brazing material 15 on the lower surface 12 u of the heat-resistant block 12 turned upside down, and heats the heat-resistant block 12 to the melting point of the silver brazing material 15 or more. After that, by cooling, the heat conductive layer 14 can be formed, so that it can be easily manufactured.

[0028]

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

(1) By interposing a metal-containing heat conductive layer at the boundary between the heater and the heat-resistant block, the heat conductivity between the heater and the heat-resistant block can be improved. Since heat is efficiently transmitted to the heat-resistant block via the heat-conducting layer, the temperature distribution of the heat-resistant block is made uniform, and the object to be heated can be uniformly heated.

(2) By forming a heat conducting layer not only at the boundary between the heater and the heat-resistant block, but also on the lower surface of the heat-resistant block provided with the heater, the heat of the heater is reduced. Since the heat is efficiently transmitted to the entire lower surface of the heat-resistant block via the conductive layer, the temperature distribution of the heat-resistant block is further uniformed, and the uniform heating of the object to be heated is improved.

(3) Since the heat conductive layer is formed of a brazing material, the heater and the heat-resistant block are firmly joined to each other, and the heat conduction between them is improved. The distribution will be uniform. In addition, since the brazing material has a lower melting point than the heat-resistant block body and the heater, and has good wettability and fluidity, the brazing material spreads without gaps at the boundary between the two and the surface provided with the heater, and a heat conductive layer having excellent adhesion is provided. It is possible to form. In addition, the brazing material has very little deterioration even after a long-time heating operation, and thus has good durability.

(4) By using a silver solder having silver having a high thermal conductivity as a main component as a brazing material, it becomes possible to form a heat conductive layer having a higher thermal conductivity.
The temperature distribution at a higher level can be made uniform.

(5) By setting the thickness of the thinnest portion of the heat conductive layer to 0.1 mm to 2 mm, it is possible to obtain a heat conductive layer having a good heat conductive state at low cost, and It is effective for uniform heating.

[Brief description of the drawings]

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

FIG. 2 is a partially cutaway perspective view of the heating device shown in FIG.

FIG. 3 is a partial 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 apparatus 11 Heated object 12 Heat resistant block 12f Heating surface 12u Lower surface 13 Heater 14 Heat conductive layer 14t Thickness in the thinnest part of heat conductive layer 15 Silver brazing material 16 Heat source

Claims (5)

[Claims] 1. A heating apparatus comprising: a heat-resistant block on which an object to be heated can be placed; and a heater attached to a lower surface of the heat-resistant block, wherein the heater, the heat-resistant block, A heating device characterized in that a heat conductive layer containing a metal is interposed at a boundary portion of the heating device. 2. The heating apparatus according to claim 1, wherein the heat conductive layer is formed on a lower surface of the heat resistant block provided with the heater. 3. The heating device according to claim 1, wherein the heat conductive layer is formed of a brazing material. 4. The heating device according to claim 3, wherein said brazing material is silver brazing. 5. The heating device according to claim 1, wherein the thickness of the thinnest portion of the heat conductive layer is 0.1 mm to 2 mm.