JPS5912420A - Element having insulating film - Google Patents

Abstract

PURPOSE:To form an insulating film for an element such as a liq. crystal display element by treatment at a low temp. and to prevent the coloring of the film by using an aromatic polyether imide polymer having specified repeating units as the material of the film. CONSTITUTION:An insulating film for an element is formed using an aromatic polyether imide polymer having repeating units represented by formula I (where each of Ar and R is a bivalent aromatic residue). Thus, an orienting film or the like for a liq. crystal display element can be formed by treatment at a low temp., and the film is not colored and has superior transparency. The aromatic polyether imide polymer represented by formula I can be manufactured by the polycondensation of dinitrophthalamide of aromatic diamine represented by formula II with alkali metallic diphenoxide represented by formula III (where M is an alkali metal) or the polycondensation of bis(ether acid anhydride) represented by formula IV with aromatic diamine represented by formula V.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an element having an insulating film, and is particularly suitable for protecting the element surface of a resin-sealed semiconductor device (coating a P-N junction) or for a liquid crystal display. The present invention relates to an element having an insulating film suitable as an alignment film of the element.

2. Description of the Related Art Semiconductor devices have heretofore been known in which the surface of the element is protectively coated with a gold polyimide polymer. However, since aromatic polyimide polymers are generally insoluble in organic solvents, when coating them, a solution of polyamic acid, which is a precursor thereof, is coated, and then the solvent is removed and a ring-closing reaction is caused by heating. Therefore, a high processing temperature is required, but processing at a still temperature is not only effective in terms of workability, but also
High temperatures are also undesirable because an undesirable Au-At alloy is formed in the bonding portion and the moisture resistance of the semiconductor device is likely to deteriorate.

On the other hand, in liquid crystal cells, especially nematic liquid crystal display elements that utilize electrothermal optical effects that operate multiple times due to the action of electric fields,
It is already known that aromatic polyimide-based materials can be used as alignment films. For example, JP-A-51-65960
The polyimide obtained by the condensation of 4,4'-diaminodiphenyl ether and pyromellitic dianhydride described in the publication has good properties in terms of uniformity of orientation and durability in deterioration tests. However, such polyimide polymers are insoluble in organic solvents, so when forming an alignment film on a substrate, a solution of polyamic acid, a precursor of polyimide, is applied, and then the solvent is removed. At the same time, dehydration and ring closure are performed.

Therefore, it is necessary to set the processing temperature f: 200c,
This in turn promotes browning of the alignment film. As a result, the liquid crystal display element after encapsulating the liquid crystal has a brownish tinge, and at the same time, the field of view becomes dark, and furthermore, the contrast deteriorates, and the function as a display element, especially the need for high quality display, is not met. there were.

Furthermore, as demand for multilayer liquid crystal cells having a structure in which two or more liquid crystal layers are laminated via a transparent substrate has increased in recent years, coloring has become a problem with conventional polyimide alignment films.

The present invention is characterized by providing an element having an insulating film that can be formed by low-temperature processing. Particularly for liquid crystal displays, the purpose is to provide transparency without coloring during film formation. It is an object of the present invention to provide a liquid crystal display element having an alignment film which is excellent and has an inconspicuous Nesa pattern.

In the present invention, the thickness of the semiconductor element coating film made of the aromatic polyetherimide polymer is preferably 1 to 30
It is selected from the range of 0 μm. In particular, when the semiconductor device 1d is a memory and a protective coating is applied to prevent soft errors caused by alpha rays, it is desirable to select a thickness of 30 to 100 μm.

The aromatic polyetheramide polymer used in the present invention is produced by *condensation of dinitro-7-talimide of an aromatic diamine represented by the general formula (IV) and an alkali metal diphenoxide represented by the general formula (■), or HEN E'-NH2 (■) is obtained by polycondensation of the bis(ether acid anhydride) of Vl) and the aromatic diamine of the general formula (■) (However, the above formulas (M) to (■) In,
Ar and R are divalent aromatic residues, M represents an alkali metal).

In order to reduce the coloration of liquid crystal display elements, which was a drawback of conventional polyimide films, and improve transparency, the present inventors conducted repeated studies in order to obtain a polyimide that can be processed at relatively low temperatures and has less coloration. . As a result, it was found that certain polyetherimides are soluble in polar solvents such as dimethylformamide, dimethylacetamide, and N-methylpyrrolidone. Using a solution of polyetherimide,
Since film formation requires only the removal of the solvent, processing can be performed at a relatively low temperature, and the alignment film is less likely to be colored.

The aromatic polyetherimide polymer used in the present invention has little coloring, is excellent in transparency, and can form an alignment film having sufficient liquid crystal alignment properties without conspicuous Nesa patterns. Furthermore, the alignment film of the present invention is also excellent for use in multilayer liquid crystal displays.

Four examples of dihydric phenols used in the production of the aromatic polyetherimide used in the present invention are 2,2-bis(4-hydroxyphenyl)propane,
4.4'-dihydroxydiphenyl ether, hydroquinone, catechol, bis(4-hydroxyphenyl)
Methane, 4,4'-dihydroxydiphenylsulfone,
4.4'-dihydroxybenzophenone, 4.4'-
Dihydroxydiphenyl sulfide, 2,2-bis(4
-hydroxyphenyl)-1,1,1,3,3゜3-hexafluoropronoquine, 2.5-dihydroquine/toluene, 4.4'-dihydroquine-3,3'-dimethyldiphenyl, 3.3 ', 5,5'-tetramethyl-4,4
'-dihydroxydiphenyl, bis(:4-(4-hydroxyphenoxy/)7enyl]sulfone, bis[4-(
4-Hydroxyphenoxy7)phenyl]ether, 4.
Examples include 4'-di(P-hydroxyphenoxy)benzophenone.

In addition, examples of aromatic diamines used in the production of aromatic polyetherimide used in the present invention include m-
Phenylene diamine, p-phenylene diamine, 41
''-diaminodiphenyl broban, 4.4'-diaminodiphenyl sulfide, 4.4'-diaminodiphenylsulfone, 4°4'-diaminodiphenyl ether,
1. s-diaminonaphthalene, 2,4-diaminotoluene, 2,6-di1minotoluene, 4,4'-diaminodiphenylmethane, 4,4'-diaminobenzophenone, bis["4-(4-aminophenoxy)phenyl]sulfone , 2,2-bis(:4-(4-aminophenoxy)phenyl)bronokun, 2.2-bis(4-(4-aminophenoxy)phenyl)1.1,1,3,3.3-
Examples include hexafluoropropane, 4,4'-<9-aminophenoxy)benzophenone, bis[4-(4-aminophenoxy)phenylcomethane, bis(4-(4-1minophenoxy)phenyl]ether), and the like.

The aromatic polyetherimide polymer is dissolved in dimethylpolamide, dimethylacetamide, N-methylpyrrolidone, dimethytosulfoxide, etc. to form a varnish. For coating semiconductor devices, it is possible to form a film by applying it to a film at a temperature of 100 to 200C. Thereafter, it is sealed with, for example, epoxy resin, diallylphthalate-1111N, phenol resin, unsaturated polyester resin, silicone resin, or the like.

In forming an alignment film for a liquid crystal display element, no special consideration is required when handling the polymer solution prepared as described above, and it can be carried out by brush coating, dipping, spin coating, printing, or other conventional means. .

Although the alignment film of the present invention can be formed directly on a substrate provided with a conductive layer, an even more excellent liquid crystal display element can be obtained by using one in which an inorganic insulating film is provided below or above the conductive layer. be able to.

As such an inorganic insulating film, S t 02. A4
03.

and T10. The membrane is suitable.

In addition, in the present invention, in order to obtain an even stronger alignment film, one of epoxy-based and amino-based silane coupling agents is used.
More than one species can be used together.

Examples of the 7-run coupling agent include γ-aminopropyltriethoxysilane and γ-glycidoxypropyltrimethoxysilane. For application, it may be added dropwise into the upper electrolyte solution,
Furthermore, an alignment film may be further formed on top of the silane coupling agent film.

As an example of the liquid crystal sealed in the liquid crystal display element of the present invention,
The following can be mentioned: These are usually applied as a mixture of two or more components.

(1) A mixture of biphenyl type liquid crystals, (2) A mixture of ester type liquid crystals, and (3) A mixture of cyclohexane type liquid crystals.

Next, the present invention will be explained by examples.

Example 1 52 parts by weight of 2,2-bis(4-(3,4-dicarboxyphenoxy)phenyl)propanihydride, 41 parts by weight of 2,2-bis[4-(4-aminophenoxy)phenyl] A mixture of propane, 1,000 parts of N-methylpyrrolidone, and 300 parts of toluene was stirred at room temperature for about 1 hour, and then refluxed at 150 C for about 1 hour. At this time, the water produced was distilled off by azeotropy. Furthermore, 200 parts of toluene was added, and the toluene was distilled off to give 18011 parts.
After raising the temperature to 1', it was cooled. A 15% solution of the aromatic polyetherimide polymer thus obtained in kN-methylpyrrolidone was prepared. Apply this to MO8mLSI and heat at 100C for 130 minutes at 150C.

A film with a thickness of about 40 μm was formed on the surface of the device by heating at 200C for 1 hour and 12 hours.

Thereafter, it was transfer molded and sealed with epoxy resin.

80C190%RH of this semiconductor device.

The i, ooo time and number of hours failure rate was excellent at 0/90.

Example 2 An aromatic polyether was prepared in the same manner as in Example 1 using 0.1 mol of 2,2-bisC4-(3,4-dicarboxyphenoxy)phenyl]propan dianhydride and 0.1 mol of metaphenylenediamine. An imide polymer was obtained. Similarly, a varnish with a solid content of 15% was made from alS, MO8'm, LS
It was applied to I. The moisture resistance of this semiconductor device at 80C190% was good.

Example 3 43.6 parts of bis(4-(4-hydroquinophenoxy)
[phenyl]sulfone, a NaOH aqueous solution prepared by dissolving 8 parts of sodium hydroxide in 50 parts of water, 30 parts of dimethyl sulfoxide, and 100 parts of benzene by heating with stirring and azeotroping the water with the benzene. Removed. Next, 45.8 parts of 1,3-di[4-nitrophthalimino]hensen and 300 parts of dimethylsulfoxy I-"k were added. After reacting for 2 hours at 120C, the reaction mixture was poured into methanol, The polymer was allowed to settle.

After drying the obtained powder, it was dissolved in dimethylformamide, applied to MO8 type IC, and heated at 80C for 30 minutes at 150C1.
After heating at 180C for 1 hour and 2 hours, it was sealed with epoxy resin. This semiconductor device had good moisture resistance.

Example 4 52 parts by weight of 2,2-bisC4-(3,4-dicarboxyphenoxy)phenyl]propanihydride, 41 parts by weight of 2,2-bis(4-(4-aminophenoxy)phenyl) ] A mixture of propane, 1,0001 parts of N-methylpyrrolidone, and 300 parts by weight of toluene was stirred at room temperature for about 1 hour, and then refluxed at 150 C for about 1 hour. At this time, the water produced was distilled off by azeotropic distillation. In addition, toluene 2
00 parts were added thereto, the temperature was raised to 180C while toluene was distilled off, and then the mixture was cooled. Aromatic polyetherimide polymer kN-methylpyrrolidone 7% thus obtained
Prepared in solution. An alignment film of 50,100,1501 m was entirely printed on the liquid crystal cell substrate using a polymer solution using an offset printing machine, and the solvent was removed by heating for 180 tll for 1 hour.After that, the film was rubbed in a certain direction with a cotton cloth. An element was fabricated by applying an organic seal of epoxy resin to the two substrates using a spacer.Thus, the elements were formed, and these elements were coated with (1) piphenyl type liquid crystal.

After separately injecting (2) ester-type liquid crystal and (3) cyclohexane-type liquid crystal, each injection port was sealed with epoxy resin to produce a liquid crystal display element. In either case, high-quality elements with very excellent transparency and inconspicuous Nesa patterns could be obtained.

Example 5 0.1 mole of 2,2-bis[4-(3,4-dicarboxyphenogisi)phenyl]propanihydride;
An aromatic polyetherimide polymer was obtained in the same manner as in Example 1 using mol of metaphenylenediamine.

Adding 0.1% by weight of globiltriethoxy 7ran to this polymer solution, forming an alignment film in the same manner as in Example 1,
A liquid crystal display element was fabricated using a glass frit seal, and its transparency and presence or absence of a Nesa pattern were examined.

In both cases, high-quality elements with very excellent transparency and inconspicuous Nesa patterns could be obtained.

Example 6

Claims (1)

[Claims] (1) The insulating film has the general formula (I) [However, Ar and 几 represent divalent aromatic residues. 1. An element having an insulating film comprising an aromatic polyetherimide polymer having repeating units excavated with ]. 2. Claim 1, wherein the aromatic polyetherimide polymer represents a group selected from the group consisting of formula (It), and X represents so2. co. An element having an insulation M characterized in that it is a polymer having a cylindrical unit. 3. t￥j Claim 1, wherein the aromatic polyetherimide polymer is selected from the group consisting of formula (III), and X is O, SO, or CO. An element having an insulating film characterized by being a polymer having units. 4. An element having an insulating film according to claim 1, 2, or 3, wherein the aromatic polyetherimide polymer layer has a thickness of 1 to 300 IJm. . 5. An element having an insulation M according to claim 1, 2, 3, or 4, wherein the insulation film coats a surface of the semiconductor element. 6. In claim 5, if the semiconductor element is a memory, the thickness of the aromatic polyetherimide polymer layer is 30-100 μm? A device with a characteristic insulating film. 7. vfWf Claims 1, 2, 3,
Or according to item 4, the device having an insulating HM, wherein the insulating film is an alignment film of a liquid crystal display device.