JPS6399225A - Substrate for electronic device - Google Patents

Abstract

PURPOSE:To obtain the titled substrate, consisting of an organic high polymer film with a specific value or above of thermal diffusivity, having excellent heat radiation properties and capable of improving reliability of electronic parts as well as electronic devices. CONSTITUTION:A substrate consisting of an organic high polymer film having >=0.01cm<2>/sec, preferably >=0.015cm<2>/sec thermal diffusivity at 20 deg.C, preferably electron conjugated high polymer film, e.g. polypyrrole, polythiophene, polyfuran, poly-p-phenylene, poly-p-phenylenevinylene, polyanthracene, etc.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a substrate for electronic devices used in the field of electronic engineering, and more specifically, it relates to a substrate for an electronic device that is used in the field of electronic engineering. The present invention relates to a substrate for electronic devices.

[Conventional technology]

As science and technology progress, there is a need for the development of electrical and electronic materials with new functions, and research is being actively conducted in the field of polymers.

BACKGROUND OF THE INVENTION Polymer materials have traditionally been used in the field of electronic engineering as electronic materials that take advantage of their properties such as insulating and dielectric properties. For example, lathographic materials such as font resists used in the semiconductor device processing process, insulating materials such as glabella insulating films, coating materials, sealing materials, structural materials such as printed circuit boards, base materials such as floppy disks, optical disks, and magnetic tapes. etc. are the main ones.

However, polymers have poor heat resistance, are flammable, and have a low thermal diffusivity, so it is necessary to be careful when manufacturing and using them as electronic materials, and the reliability is also low. It was hard to say that there were no problems.

In addition, with recent advances in electronic engineering technology, the integration of semiconductor elements has progressed, and the amount of heat generated per unit area has also increased, but because the heat dissipation of the polymer materials used is poor, it is difficult to disperse the heating element. The current situation is to use a cooling fan to cool the device forcibly.

On the other hand, the development of new materials has progressed in the field of polymers, resulting in conjugated polymer films such as polyacetylene and polyvaraphenylene, or films in which electron-donating or electron-withdrawing compounds (dopants) are retained (doped). Polymer semiconductors have been developed to date. Among these, polymers containing aromatic compounds as monomers are attracting attention because of their excellent stability in air and heat resistance. For example, in Journal of the Chemical Society, Chemical Communications, 1985, p. 1629, by the present inventors, a polyvaraphenylene film produced by electrolytic oxidative polymerization of benzene is exemplified. This film is stable in air and has heat resistance up to 500°C, and its electrical properties such as electrical conductivity and optical properties such as absorbed light vary greatly depending on the type and amount of dopant. However, such aromatic conjugated polymer films are currently in the research and development stage, and their physical properties and structures are often unclear, so they have not been used industrially at present.

[Problem that the invention seeks to solve]

As mentioned above, polymer materials used in the electronics field generally have poor heat resistance, are flammable, and have a low thermal diffusivity, which limits the manufacturing and usage conditions. . Furthermore, for the same reason, there was also the problem that the reliability of parts and equipment themselves using polymeric materials decreased.

[Means for solving problems]

The present inventors have addressed the above-mentioned problem, namely that polymer materials used in the electronics field generally have insufficient heat resistance and heat dissipation properties, which limits manufacturing and usage conditions and the use of parts using them. As a result of various studies, we have developed a substrate for electronic devices made of an organic polymer film with a thermal diffusivity of 0.01 cm"/see or higher at a temperature of 20 degrees Celsius. Thus, the present invention provides a substrate for an electronic device made of an organic polymer film having a high thermal diffusivity and excellent heat dissipation properties, which is used in the field of electronic engineering.

Note that the organic polymer of the present invention does not include carbon materials such as carbon fibers obtained by treating organic compounds at high temperatures of 800° C. or higher.

The organic polymer film constituting the electronic device substrate of the present invention is characterized by having a high thermal diffusivity, and specifically, the thermal diffusivity at a temperature of 20°C is 0.01 cm"/sec.
The above value is preferably 0.015 cm"/sec or more. These values are 0.0013 cm"/sec for commonly used polymer films, such as low density polyethylene, and 0.00 cm"/sec for polystyrene and polymethyl methacrylate.
1 cn+”/sec, 0 of polytetrafluoroethylene
．． Much larger than 00098cm”/see,
Far beyond the scope of general polymer films,
It is close to the realm of metals.

In the present invention, these highly thermally diffusive organic polymer films are used as substrates for electronic devices in various electronic components or electronic equipment, and are mainly used for insulating materials such as interlayer insulating films, Applications include coating materials, sealing materials for integrated circuits, base materials for printed circuit boards, floppy disks, thermal transfer ink ribbons, magnetic tapes, etc., and dielectrics for capacitors. Conventionally, polymer films such as polyester and phenol resin have been used for these purposes, but their thermal diffusivities have all been 0.002 cmz/sec or less.

In view of the above points, the inventors of the present invention have made extensive studies and have found that
The relationship between thermal diffusivity and heat dissipation was determined, and it was concluded that an organic polymer film with a thermal diffusivity of 0.01 cn+''/sec or more at a temperature of 20° C. has sufficient heat dissipation for practical use.

The highly thermally diffusible organic polymer film of the present invention mainly includes various electronically conjugated polymers, and among them, those whose polymer repeating units are aromatic compounds and derivatives thereof are preferred. Examples of such electronically conjugated polymers include polymers of five-membered heterocyclic compounds such as polypyrrole, polythiophene, and polyfuran, and derivatives thereof, and polymers of benzene and benzene derivatives such as polyparaphenylene, polyparaphenylene vinylene, and polyaniline. , polymers of polynuclear aromatic compounds such as polynaphthalene, polyanthracene, and polytetracene.

The above-mentioned electronically conjugated polymers can be produced by polymerizing monomers such as aromatic compounds or their derivatives using an oxidizing agent, oxidation catalyst, Grignard catalyst, etc., or by electrochemical polymerization by dissolving or dispersing them in an electrolytic solution. Examples include a method of performing anodic oxidation polymerization, and a method of using a non-electronically conjugated polymer film as an intermediate and heat-pressing it at a temperature of 600° C. or lower to obtain an electronically conjugated polymer film.

In the present invention, the thermal diffusivity and heat dissipation characteristics of the above-mentioned organic polymer film were studied, and the thermal diffusivity at a temperature of 20°C was 0.
It has been found that a film with a heat dissipation rate of 0.01 cm"/sec or more has good properties as a substrate for electronic devices, and the thermal diffusivity is measured by the optical alternating current method.Hereinafter,
The principle will be outlined below.

That is, when part of a film-like sample is intermittently irradiated with light having an illuminance Q, the AC temperature amplitude I Tacl at a distance from the boundary of the irradiated surface is expressed by the following equation.

ω: Intermittent frequency C: Heat capacity per unit volume d: Film thickness D: Thermal diffusivity At this time, the change in l Tac l with respect to L is expressed by the following equation.

In (lTacl tt*, 1L)) −1n (
lTaclL) = ΔL, by changing the distance, actually measuring lTacl, and plotting its logarithm.As a thermal diffusivity measuring device based on the principle of slope, the optical AC manufactured by Shinku Riko ■ Legal thermal constant measuring device PI
There is T-1.

As described above, when the highly thermally diffusive organic polymer film of the present invention is used as a substrate for electronic devices, there is not only the advantage that a cooling device can be omitted or downsized due to good heat dissipation properties, but also the organic polymer When is an electronically conjugated polymer composed of repeating units made of aromatic compounds or derivatives thereof, these polymers have heat resistance from 200°C to 550°C, so that the high temperature of equipment using this polymer is The credibility of the test will also be greatly improved.

A thermal diffusivity of 0.015 ca+2/sec or more is particularly preferably used.

In general, the electrical conductivity of electronically conjugated polymers can be controlled by doping, and various materials with different electrical conductivities can be prepared, from insulators to semiconductors to conductors.
The electronic device substrate of the present invention can be used with electrical conductivity controlled as required. That is, when the organic polymer of the present invention is an electronically conjugated polymer, when it is made into an insulator, the dopant contained in the film is electrochemically or chemically neutralized or desorbed at a high temperature of 200°C or higher. When used as a semiconductor or conductor, it is doped using an electrochemical or chemical method.

〔Example〕

EXAMPLES The present invention will be specifically described below with reference to Examples, but the present invention is not limited to these Examples.

Example 1 Organic polymer films A to H shown below were prepared.

tJ, Material A: Polyparaphenylene film manufacturing method; 0.5 M benzene, 0.1 M LiAsF, and 0
．． Two platinum plates were immersed as electrodes in a nitrobenzene solution containing 1M CuC1z, and a constant voltage of 20μ was applied to 120
Anodic oxidation polymerization of benzene was performed by applying it for a minute. The product after drying under reduced pressure was a black film with a thickness of 18 layers.

E14B: Polyparaphenylene film manufacturing method; The sample was manufactured by heat-treating it at 400° C. for 6 hours under reduced pressure.

Sample C: Polypyrrole film manufacturing method; A platinum plate (2
A constant voltage of 4.0 μm was applied for 120 minutes to carry out anodic oxidation polymerization of virol. The product after drying under reduced pressure was a black film with a thickness of 15 mm.

Sample D = Polythiophene film manufacturing method; Platinum plates (2 pieces) were immersed as electrodes in a benzonitrile solution containing 0.1 M thiophene and 0.5 M LiBFn, and a constant voltage of 15 V was applied for 60 minutes to release thiophene. Anodic oxidation polymerization was performed. After the reaction, the anode and cathode were short-circuited for 30 minutes for electrochemical dedoping, and the product was taken out. The product after drying under reduced pressure was a glossy green film with a thickness of 20 mm.

IE, polyfuran film manufacturing method: Platinum plates (2 pieces) were immersed as electrodes in an acetonitrile solution containing 0.1M furan and 0.5M LiClO4,
A constant voltage of 6.5 V was applied for 150 minutes to perform anodic oxidation polymerization of furan.

After the reaction, the anode and cathode were short-circuited for 30 minutes for electrochemical dedoping, and the product was taken out. The product after drying under reduced pressure was a dark brown film with a thickness of 18 mm.

Sample F: Borianthracene film production method; Platinum plates (2 pieces) were immersed as electrodes in an orthodichlorobenzene solution containing 0.2M anthracene, 0.1M tetrabutylammonium perchlorate, and 0.1M CuCLz. , a constant voltage of 15 V was applied for 60 minutes to carry out anodic oxidation polymerization of anthracene. The product after vacuum drying has a film thickness of 1
It was a black film that caught my attention.

Sample G: Low density polyethylene film A commercially available film with a thickness of 25 mm was used as it was.

Sample H: Polytetrafluoroethylene film thickness 25
I! A commercially available film of M was used as it was.

Thermal diffusivity and heat dissipation characteristics of the above samples A to H were evaluated. Thermal diffusivity was measured at a temperature of 20°C using a vacuum Riko's dimming alternating current method thermal constant measuring device PIT-1. In addition, the heat dissipation characteristics were evaluated by placing the sample in the air at 20°C with a width of 1 cm.
The sample was gripped with a copper chuck with a length of 2c+n, and the center of the sample was locally heated to 40° C. to examine the heat dissipation characteristics.

Heating was performed by light irradiation, using a 300-inch light bulb as the light source, and the irradiation area was 0.5 cm x 5 cm. In this measurement, heat flows from the heating part through the sample to the copper chuck, allowing for an evaluation that is more similar to the actual system.
Physical property values such as thermal conductivity cannot be obtained. Therefore, we relatively evaluated the degree of temperature drop after heating was stopped, and marked ○ for those considered to be advantageous in practical use, × for those considered to be disadvantageous, and △ for others. .

Table 1 summarizes the results obtained.

Table 1 As shown in Table 1, the sample of the present invention, which has a high thermal diffusivity, exhibits good heat dissipation properties, and is superior to conventional polymers such as polyethylene and polytetrafluoroethylene as substrates for electronic devices. It can be seen that the cooling and reliability of the device is superior to that of the standard.

〔Effect of the invention〕

By carrying out the present invention as described above, it is possible to provide an electronic device substrate made of an organic polymer film with excellent heat dissipation properties used in the field of electronic engineering, and as a result, electronic components using the same can be provided. , it has industrial value because it can improve the reliability of electronic equipment.

Claims (1)

[Claims] Thermal diffusivity at a temperature of 1.20°C is 0.01cm^2/s
An electronic device substrate made of an organic polymer film of EC or higher. 2. The electronic device substrate according to claim 1, wherein the organic polymer film is an electronically conjugated polymer film. 3. The electronic device substrate according to claim 2, wherein the electronically conjugated polymer is selected from the group consisting of polypyrrole, polythiophene, polyfuran, polyparaphenylene, polyparaphenylene vinylene, and polyanthracene.