JP2000263561A - Heat treatment method and heat treatment device for sheet material - Google Patents

Abstract

(57) [Summary] [PROBLEMS] When a sheet material is transported in a belt shape into a heating oven, heated, and wound into a roll in the heating oven, the heat treatment is performed without using a spacer for the accompanying winding. This prevents blocking of the sheet material by a volatile substance volatilized from the sheet material. SOLUTION: A sheet-like material 1 is heated in a belt shape in a heating oven 3.
When carried in, heated, and wound into a roll in the heating oven 3, volatile substances volatilized from the sheet material 1 due to the heat treatment do not adhere to the sheet material 1 wound into a roll. As described above, the heat treatment is performed while discharging the volatilized volatile substance out of the heating oven 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat treatment method and a heat treatment apparatus for a sheet material such as a polyimide wiring board useful for a flexible printed circuit board.

[0002]

2. Description of the Related Art When a polyimide wiring board is manufactured by using a polyamic acid which is a polyimide precursor, it is manufactured as follows. That is, the copper foil wound up in a roll shape is unwound, a polyamic acid solution is applied to one side of the copper foil and dried to form a polyamic acid layer (polyimide precursor layer).
After passing through a continuous heating oven for imidizing the polyamic acid layer, the polyamic acid layer is turned into a polyimide layer and then wound up in a roll to obtain a polyimide wiring substrate. Here, in order to completely imidize the polyamic acid, it is necessary to heat at a temperature of 280 to 350 ° C. for several tens minutes. For this reason, when manufacturing a polyimide wiring board as described above, a very long continuous heating oven is required, and there is a problem that a huge capital investment and a maintenance cost are required.

[0003] In view of this, it has been practiced to put a sheet material in which a polyamic acid is laminated on a metal foil on a roll into a relatively small heating oven to imidize it in a batch system. . In this case, among the volatile substances volatilized from the polyamic acid layer at the time of imidization, in addition to the solvent and water, etc., "yano" which causes blocking between sheet-like materials that are in surface contact with each other The substance is present. For this reason, when the sheet material is roll-wound so that the blocking does not actually occur, the enclosing spacer having one flat surface and the other rough surface is provided so that the rough surface is in contact with the polyamic acid layer. (Japanese Patent Application No. 8-224797). Using this entraining spacer, the volatilized "yani"
It is alleged that the substance is discharged from the continuous concave portion of the rough surface of the enclosing spacer through the side surface of the roll, so that blocking can be prevented.

[0004]

However, even when such a spacer for entrainment is used, it is quite difficult to completely discharge the volatilized "yari" substance from the side of the roll. However, there was a problem that blocking could not be prevented. There is also a problem that the shape of the rough surface is transferred to the polyimide wiring substrate. Furthermore, since the "yani" substance adheres to the concave portion of the rough surface of the entrained spacer, the repeated use of the entrained spacer is restricted, and the use of the entrained spacer increases the manufacturing cost of the polyimide wiring board. There were also problems.

[0005] The problem of the polyimide wiring board as described above is a problem that occurs when a sheet-like material containing a volatile substance that causes blocking is heated in a roll shape.

[0006] The present invention is to solve the above-mentioned conventional technology. As in the case of manufacturing a polyimide wiring board, a sheet-like material is carried in a belt-like shape into a heating oven, and is subjected to a heat treatment to be heated. An object of the present invention is to prevent a blocking of a sheet material from occurring due to a volatile substance volatilized from the sheet material by a heat treatment without using a spacer for winding when a roll is wound in a roll in an oven. .

[0007]

SUMMARY OF THE INVENTION The present inventors have determined that volatile substances, such as those that cause blocking, are volatilized in the early stages of heating, and thus such volatile substances are wound up in rolls in a heating oven. It has been found that the above-mentioned object can be achieved by performing the heat treatment while discharging the volatile substance out of the heating oven so that the volatile substance does not adhere to the sheet-shaped material, thereby completing the present invention.

That is, the present invention provides a method for heat-treating a sheet-like material comprising the steps of carrying a sheet-like material in a belt shape into a heating oven, heat-treating and winding the sheet-like material into a roll in the heating oven. Provided is a method characterized by performing a heat treatment while discharging a volatile substance that has been volatilized from a sheet material so as to prevent the volatile substance from being volatilized from adhering to the sheet material that is wound into a roll. I do.

The present invention also provides the following heat treatment apparatus as an apparatus for performing the above-described sheet material heat treatment method.

That is, the present invention relates to a heat treatment apparatus for heat-treating a sheet-like material, comprising: a heating oven for providing a heating space for heating the sheet-like material; A winding means for winding the sheet-like material conveyed in a belt shape from the heating oven into a roll in the heating oven, a heating gas introduction means for introducing a heating gas into the heating oven, and a heating oven. And a gas exhaust means for discharging the heating gas to the outside of the heating oven: a heating space dividing means for dividing the heating space is provided in the heating oven; The drawing means is provided with a sheet-like material introduction port and a sheet-like material lead-out port, and the exhaust means is connected to the heating gas introduced into the heating oven from the heating gas introduction means. Is introduced into the heating space fractionating means from at least one of the sheet-shaped material introduction port and the sheet-shaped material discharge port, exhausted from the heating oven by the exhaust means, and the sheet carried into the heating oven. The sheet-like material is introduced into the heating space fractionating means from the sheet-like material introduction port, and heat-treated in the heating space fractionating means. Here, volatile substances volatilized from the sheet-like material by the heating treatment are discharged from the exhaust means. A heat treatment apparatus is provided, wherein the heat treatment apparatus is evacuated outside a heating oven, a sheet material is drawn out from a sheet material outlet, and wound up in a roll shape by a winding means.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The method for heat-treating a sheet-like material according to the present invention includes a step of carrying a sheet-like material in a belt shape into a heating oven, and winding the sheet-like material into a roll in the heating oven while performing heat treatment. . Here, a volatile substance is volatilized from the sheet material by the heat treatment in an initial stage of the heat treatment. Examples of the volatile substance include various substances such as a solvent, water, a monomer, and a decomposed product, and among them, there are cases where a volatile `` slightly '' substance that causes blocking of the sheet material is present. is there. In the present invention, such volatile substances are wound into a roll, because such volatile substances cause blocking when they adhere to a sheet-like material wound on a roll in a heating oven. The heat treatment is performed while discharging the volatilized volatile substance out of the heating oven so as not to adhere to the sheet material thus obtained. For example, a fraction heating area is provided in a heating oven, and in the fraction heating area, the sheet material is subjected to a heat treatment while volatile substances are discharged out of the heating oven, and then the sheet material is taken out from the fraction heating area. What is necessary is just to wind up in a roll shape.

This heat treatment method for a sheet material is a method for manufacturing a polyimide wiring board when a material in which a polyamic acid layer is formed on a metal foil is used as the sheet material. That is, the manufacturing method of the polyimide wiring board,
Polyimide containing a process in which a sheet material having a polyamic acid layer formed on a metal foil is carried in a belt shape into a heating oven, heated to imidize the polyamic acid layer, and wound into a roll in the heating oven. A method for manufacturing a wiring board, wherein a volatile substance that is volatilized from a sheet material by heat treatment and that causes a blocking of the sheet material is rolled into a sheet material. The heat treatment is performed while discharging the volatilized volatile substance out of the heating oven so as not to adhere.

In order to explain the heat treatment method of the present invention in detail, an example of a heat treatment apparatus for carrying out the heat treatment method will be described with reference to the drawings.
This clarifies the technical advantages of the heat treatment method of the present invention.

The heat treatment apparatus for a sheet-like material according to the present invention comprises:
It is a heat treatment device to heat-treat the sheet material,
Heat treatment can be performed not only on the sheet material before being wound on the roll, but also on the sheet material after being wound on the roll.

The heat treatment apparatus includes a heating oven 3 for providing a heating space 2 for heating the sheet material 1,
Winding means 5 for winding the sheet-like material 1 conveyed in a belt shape into the heating oven 3 from the sheet-like material entrance 4 of the heating oven 3 into a roll inside the heating oven 3.
And a heating gas 6 such as an inert gas (for example, nitrogen gas).
Heating gas introducing means 7 installed in the heating oven 3 to introduce (dotted arrow in the figure) into the heating oven 3;
An exhaust unit 8 is provided for discharging the heating gas 6 in the heating oven 3 to the outside of the heating oven 3. Furthermore,
Heating space separating means 9 for separating the heating space 2 in the heating oven 3 is provided between the sheet material inlet 4 of the heating oven 3 and the winding means 5. The drawing means 9 is provided with a sheet material inlet 9a and a sheet material outlet 9b, and is connected to the exhaust means 8 described above.

The sheet-like material 1 carried into the heating oven 3 is introduced into the heating space dividing means 9 from the sheet-like material introduction port 9a. It is drawn out from the material outlet 9b and wound up in a roll shape by the winding means 5. Here, the heating gas 6 introduced into the heating oven 3 from the heating gas introduction means 7 is supplied to the sheet-like material introduction port 9 a of the heating space fractionating means 9.
Then, the sheet-like material 1 is introduced into the heating space fractionating means 9 from at least one of the sheet-like material outlet 9b, and the sheet-like material 1 is sufficiently heated in the heating space dividing means 9. For this reason, the volatile substances contained in the sheet material 1 are volatilized in the heating space fractionating means 9. Then, the volatilized volatile substance is directly exhausted to the outside of the heating oven 3 from the exhaust means 8 provided in the heating space fractionating means 9.
Accordingly, the sheet-like material 1 wound in a roll in the heating oven 3 does not adhere to a volatile substance that causes blocking. In addition, since the rolled sheet material 1 still exists inside the heating oven 3, the rolled sheet material 1 can be sufficiently heat-treated in the roll shape.

When this heat treatment apparatus is used for imidizing a polyamic acid layer on a metal foil, a volatile substance which causes blocking is removed from the heating space fractionating means 9 in the initial stage of the heat treatment. Thus, the gas can be volatilized from the polyamic acid layer, and can be directly exhausted to the outside of the heating oven 3 without being diffused throughout the heating oven 3. Moreover, the sheet material (metal foil / polyamic acid layer) from which the volatile substances have been removed can be heat-treated in a heating oven 3 in a roll form for a sufficient period of time, so that it can be imidized without blocking. can do.

In the heat treatment apparatus of the present invention, the heating space fractionating means 9 divides a heating space of the heating oven 3 and heat-treats the sheet material 1 in the divided space. Means can be adopted. For example,
A rectangular parallelepiped cylindrical body (FIG. 1) or an annular cylindrical body (FIG. 2) can be used as the heating space dividing means 9. Among them,
The annular shape shown in FIG. 2 can be preferably adopted from the viewpoint of miniaturization of the device.

In the heat treatment apparatus of the present invention, before the sheet material 1 is carried into the heating oven 3, the sheet material 1
It is preferable to further install a preheating oven 10 for preheating (FIG. 3). By providing the preheating oven 10, the sheet material 1 can be heated step by step, and problems caused by rapid volatilization of volatile substances (such as holes in the sheet material) can be avoided.

The components (for example, heating oven 3, winding means 5, heating gas 6, heating gas introduction means 7,
For the exhaust means 8 and the like, known devices and gases can be appropriately selected and used.

The heat treatment described above is performed by a coating apparatus (not shown) for producing a sheet material to be fed into the metal foil having a polyamic acid layer formed on a metal foil.
Is useful as a polyimide wiring board manufacturing apparatus for a polyimide wiring board.

[0022]

The present invention will be described below in more detail with reference to examples.

Example 1 In a 60-liter reaction vessel equipped with a temperature controller and a jacket, 1.05 kg (11.2 mol) of paraphenylenediamine (PDA, manufactured by Mitsui Chemicals, Inc.) and 4,4'-diaminodiphenyl ether ( DPE, manufactured by Wakayama Seika)
0.86 kg (4.8 mol) of a solvent N-methyl-pyrrolidone (NMP, manufactured by Mitsubishi Chemical Corporation) under a nitrogen gas atmosphere
Dissolved in about 45 kg. Then, at 50 ° C., pyromellitic dianhydride (PMDA, manufactured by Mitsubishi Gas Chemical Company)
The reaction was carried out for 3 hours while gradually adding 3.523 kg (16.14 mol). As a result, the solid content is about 12%,
A polyamic acid varnish having a viscosity of 25 Pa · S (25 ° C.) was prepared.

The obtained polyamic acid varnish was coated with a width of 600.
mm, 100m long copper foil (12μm thick, SQ-VL
P, manufactured by Mitsui Kinzoku Co., Ltd.), dried in a continuous furnace at 80 to 170 ° C., and wound up on a roll. The remaining volatile content is 30.
4%.

The obtained roll is set in a heat treatment apparatus (line speed = 1 m / min) shown in FIG. 3 and is heated in a preheating oven using a heating nitrogen gas whose oxygen concentration is adjusted to 0.2% or less as a heating medium. Preheat to 230-350 ° C,
Further, the mixture was heated to 350 ° C. with the same heating nitrogen gas and wound up in a roll in a heating oven. After winding, 1 more
The temperature was kept at 350 ° C. for 5 minutes, and the polyamic acid was completely imidized to produce a polyimide wiring substrate. After heating,
After cooling to 200 ° C. with nitrogen gas, it was taken out of the heat treatment apparatus.

The obtained polyimide wiring substrate wound up in a roll was not blocked and could be easily rewound.

[0027]

According to the present invention, as in the case of manufacturing a polyimide wiring board, when a sheet-like material is carried in a belt shape into a heating oven, heated, and then wound into a roll in the heating oven. Even without using the entrainer spacer, blocking of the sheet material does not occur due to volatile substances volatilized from the sheet material by the heat treatment.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a heat treatment apparatus.

FIG. 2 is a schematic diagram of a heat treatment apparatus.

FIG. 3 is a schematic diagram of a heat treatment apparatus.

[Explanation of symbols]

1 sheet material, 2 heating space, 3 heating oven,
4 Sheet material inlet, 5 Winding means, 6 Heating gas, 7 Heating gas introduction means, 8 Exhaust means

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) B32B 15/08 B32B 15/08 R 4J043 C08G 73/10 C08G 73/10 // B32B 27/34 B32B 27/34 F26B 13 / 10 F26B 13/10 JB29L 7:00 F term (reference) 3L113 AA02 AA08 AB02 AC01 AC21 AC28 AC31 AC48 AC49 AC53 AC63 AC65 AC67 AC78 BA26 CA08 CA12 CB01 CB13 CB19 CB24 CB34 CB35 DA05 DA07 DA14 4D075 AC21 AC84Z96 AC88 BB60Z BB65Z BB93Z CA47 DA04 DB53 DC22 4F042 AA22 BA13 BA19 DB01 DB37 DB39 DE07 DE09 DF15 4F100 AB01A AB17 AB33A AK49B BA02 BA14 EH51 GB43 JL00 4F203 AA40 AC03 AD03 AD08 AG03 AH36 DA14 DB02 DM03 DL01 DM02 DM03 DM02

Claims (8)

[Claims] 1. A method for heat-treating a sheet-like material, comprising the steps of carrying a sheet-like material in a belt shape into a heating oven, heat-treating the same, and winding the sheet-like material into a roll in the heating oven.
The heat treatment is performed while discharging the volatilized volatile substance out of the heating oven so that the volatile substance volatilized from the sheet material by the heat treatment does not adhere to the sheet material wound into a roll. Method. 2. The volatile substance is discharged out of the heating oven in a fraction heating area provided in the heating oven so that the volatile substance does not adhere to the sheet-like material wound into a roll. 2. The method according to claim 1, wherein the sheet material is heated from the fractionation heating area after the sheet material is heat-treated while being rolled. 3. A sheet-like material having a polyamic acid layer formed on a metal foil is carried in a belt into a heating oven, heated to imidize the polyamic acid layer, and wound into a roll in the heating oven. In the method for manufacturing a polyimide wiring board including a step of removing, the volatile substance that has volatilized from the sheet material by the heat treatment is removed from the heating oven so that the volatile substance does not adhere to the sheet material wound into a roll. A method for producing a polyimide wiring board, comprising performing a heat treatment while discharging to a substrate. 4. The volatile substance is discharged out of the heating oven in a fraction heating area provided in the heating oven so that the volatile substance does not adhere to the sheet-shaped material wound into a roll. 4. The method according to claim 3, wherein the sheet-shaped material is heated from the fractionation heating area after the sheet-shaped material is heated while being rolled. 5. A heat treatment apparatus for heat-treating a sheet-shaped material, comprising: a heating oven for providing a heating space for heating the sheet-shaped material; Winding means for winding a sheet-like material conveyed in a belt shape into a roll in a heating oven, heating gas introducing means for introducing a heating gas into the heating oven, and heating gas in the heating oven And a gas exhaust means for discharging the gas to the outside of the heating oven: a heating space fractionating means for dividing the heating space is provided in the heating oven, and the heating space fractionating means is provided with: A sheet-like material inlet and a sheet-like material outlet are provided, and the exhaust unit is connected, and the heating gas introduced into the heating oven from the heating gas introduction unit is the sheet gas. The sheet-like material introduced into the heating space fractionating means from at least one of the sheet-like material introduction port and the sheet-like material discharge port, exhausted out of the heating oven from the exhausting means, and carried into the heating oven, It is introduced into the heating space fractionating means from the sheet material introduction port, and heat-treated in the heating space fractionating means. Here, volatile substances volatilized from the sheet material by the heat treatment are discharged from the exhaust means to the outside of the heating oven. A heat treatment apparatus, wherein the heat treatment apparatus is evacuated, the sheet material is led out from a sheet material outlet, and wound up in a roll shape by a winding means. 6. The heat treatment apparatus according to claim 5, wherein the heating space fractionating means has an annular shape. 7. The heat treatment apparatus according to claim 5, further comprising a preheating oven for preheating the sheet material before being carried into the heating oven. 8. A coating apparatus for preparing a sheet-like material having a polyamic acid layer formed on a metal foil by applying a polyamic acid solution on a belt-like metal foil and drying the same, and a polyamic acid of the sheet-like material. An apparatus for manufacturing a polyimide wiring board, comprising: the heat treatment apparatus according to claim 5 for performing a heat treatment for imidizing an acid layer to form a polyimide layer.