JP3748101B2 - Thermocompression roller - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a thermocompression-bonding roller used in a film laminating apparatus for thermocompression bonding a film to a sheet-like substrate such as a printed wiring board.
[0002]
[Prior art]
In the process of forming a circuit, a printed wiring board may form a predetermined circuit pattern by performing thermocompression bonding on a substrate, generally called a dry film, and performing exposure and etching. At this time, the surface of the printed wiring board is often uneven, and an iron-based roller having a compression strength is generally used as a thermocompression-bonding roller in order to attach the film to the substrate without gaps.
[0003]
In addition, a heating element is incorporated in the inside to heat the roller. The heating element is preferably integrated with the roller from the viewpoint of heat conduction, but the heating element that requires electrical wiring is rotated. In this case, a roller contact point is required, and maintenance such as periodic replacement of contact parts is necessary so that the contact point does not cause poor contact. It is hollow and a fixed heating element is provided inside the hollow.
[0004]
[Problems to be solved by the invention]
However, if there is a gap between the heating element and the rotating roller, heat is not easily transmitted, and the temperature difference between the roller and the heating element tends to increase. For this reason, in particular, when it is used for an iron-based roller having a relatively small thermal conductivity among metals, temperature adjustment tends to be difficult, and the temperature distribution in the axial direction of the roller tends to be non-uniform.
[0005]
[Means for Solving the Problems]
The present invention, in order to solve the above problems, in the heating roller having a hollow roller, and a heating element fixed in said hollow, said hollow roller is not increased at least three-layer structure, the hollow The roller inner tube member is made of copper, the middle is aluminum, and the outer is made of iron or stainless steel .
[0007]
The thermal conductivity of copper is approximately 400 W · m ⁻¹ · K ⁻¹ , the linear expansion coefficient is approximately 17 × 10 ⁻⁶ , the thermal conductivity of aluminum is approximately 240 W · m ⁻¹ · K ⁻¹ , and the linear expansion coefficient is Copper having a large thermal conductivity of about 23 × 10 ⁻⁶ is particularly preferable. In comparison, the thermal conductivity of iron is about 80 W · m ⁻¹ · K ⁻¹ , the linear expansion coefficient is about 12 × 10 ⁻⁶ , and the thermal conductivity of stainless steel is about 16 W · m ⁻¹ · K ⁻¹ , The linear expansion coefficient is as small as about 12 to 16 × 10 ⁻⁶ .
[0008]
Even if the heat of the heating element is transferred to a part of copper or aluminum, which is the inner tube member of the roller, copper or aluminum has a large thermal conductivity, so even if the temperature difference between the roller and the heating element is not greatly increased, Since the heat is transmitted to the entire tube member quickly and becomes a more uniform heat conductor in the axial direction of the roller, even if the roller outer tube member is made of iron or stainless steel, which has a slow heat transfer, the roller as a whole can reduce uneven temperature distribution. Can be planned.
[0009]
In addition, since the linear expansion coefficient of copper and aluminum is larger than that of iron and stainless steel, the outer diameter of the inner tube member is made smaller than the inner diameter of the outer tube member at room temperature to facilitate insertion into the outer tube member. However, since the inner tube member expands more than the outer tube member by heating, the double structure is integrated and heat is easily transmitted.
[0010]
In other words, the present invention has a simple structure, is easy to assemble and maintain, has the strength to ensure thermocompression bonding even if there are some irregularities, and is easy to adjust the temperature, enabling uniform bonding over a wide area. The present invention provides a thermocompression-bonding roller having a high temperature distribution uniformity.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. In FIG. 1, reference numeral 1 denotes a hollow roller having a double structure. The inside of the hollow roller 1 is an inner tube member 2 made of copper or aluminum, or an alloy obtained by adding silver, chromium, or the like to copper, or an alloy obtained by adding manganese, silicon, or the like to aluminum, and the outer side is made of iron or iron, nickel, manganese The outer tube member 3 is made of an alloy or stainless steel added with molybdenum, silicon, etc., and the surface is generally baked with an elastic member 4 such as silicon rubber or fluororubber in order to have heat resistance, elasticity, or peelability. Has been. The hollow roller 1 is supported at both ends by roller bearing portions 5 and is attached to and rotated by a roller attachment movable member 6.
[0012]
The outer tube member 3 of the hollow roller 1 requires a thickness of 5 mm or more, preferably 10 mm or more, with respect to a practical roller length of about 100 mm in order to obtain a compression strength. If the wall thickness is 100 mm or more, the roller itself becomes heavy, which not only imposes a burden on the roller bearing portion 5 and the roller mounting movable member 6, but also takes time to reach the set temperature and deteriorates workability. It is appropriate that the inner tube member 2 has a thickness of about 5 to 50 mm, and the elastic member 4 has a thickness of about 0.1 to 5 mm.
[0013]
A rod-shaped heating element 7 is inserted into the hollow portion of the hollow roller 1 and fixed by a heating element fixing jig 8. Although not shown in the figure, the heating element 7 is electrically connected to an external power source and temperature control circuit. The heating element 7 incorporates an electrical resistor such as a nichrome wire and generates heat when energized. In order to keep the clearance between the heating element 7 and the hollow roller 1 constant, heater bearing portions 9 are appropriately provided at both ends thereof.
[0014]
For example, the hollow roller 1 can have a three-layer structure such as copper on the inner side, aluminum on the middle, and iron on the outer side, so that the load on the bearing portion 5 can be reduced.
[0015]
【Example】
Next, examples of the present invention will be described.
The inner tube member of the hollow roller is made of copper with an outer diameter of 40 mm, an inner diameter of 22 mm, and a length of 800 mm. The outer tube member of the hollow roller is made of iron with an outer diameter of 83 mm, an inner diameter of 40 mm, and a length of 900 mm including the shaft. Then, a baking layer of silicon rubber having a thickness of 3 mm is provided on the surface. A heating element having an outer diameter of 20 mm and a heating effective length of 740 mm is used.
[0016]
Next, for the examples of the present invention, a heating distribution test was performed 50 minutes after the set temperature of 110 ° C. was applied and heated. As a result, the temperature difference between the central portion of the roller surface of the present invention and the portion 300 mm away from the center was 3 ° C., but the tube member of the hollow roller was made of iron only, and other specifications were the same as in the examples. It was 9 ° C. for the structured roller.
[0017]
【The invention's effect】
As described above, according to the present invention, the structure is simple, easy to assemble and maintain, has the strength to ensure thermocompression bonding even if there are some irregularities, and is easy to adjust the temperature, uniform over a wide area. It is possible to provide a thermocompression-bonding roller with high uniformity of temperature distribution that can be smoothly laminated.
[Brief description of the drawings]
FIG. 1 shows a cross-sectional view of an embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Hollow roller, 2 ... Inner tube member, 3 ... Outer tube member, 4 ... Elastic member 5 ... Roller bearing part, 6 ... Roller mounting movable member, 7 ... Heating element, 8 ... Heating element fixing jig, 9 ... Heater Bearing part.

Claims (1)

A hollow roller, in the heating roller having a heating element fixed in said hollow, said hollow roller is not increased at least three-layer structure, the inner pipe member of the hollow roller is copper, the intermediate is aluminum and, A thermocompression-bonding roller characterized in that the outside is made of iron or stainless steel .

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