JPH0678430B2 - Electron-induced conversion of isoimides to N-imides and their use - Google Patents

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to the conversion of molecules containing isoimide groups into molecules containing n-imide groups and their use. More specifically, the present invention is directed to depositing polymeric materials, especially polyimides, in their imidized form on a substrate, and more particularly on a conductive substrate. The present invention is particularly directed to the electrodeposition of polyimide on a substrate from a solution containing polyisoimide.
ion).

[0002]

Background Polyimides have widespread and industrial use. In particular, polyimides are commonly used in the semiconductor and packaging industries. Polyimides are commonly used for passivating metals or insulating conductors, especially because they exhibit low dielectric properties along with high thermal and chemical stability.

In packaging semiconductor chips,
Polyimide films are often coated on a substrate.
Typically, polyamic acid or polyimide alkyl ester precursors are applied by spin coating onto the desired substrate, followed by curing by application of heat up to about 400 ° C. However, one problem with such methods is that the polyimide precursor used is reactive with metals such as copper. This in turn causes the metal to oxidize, causing the incorporation of metal oxide into the polymer mass in the cured squill. The presence of metal oxides adversely affects the dielectric properties of polyimide and the reliability of the metal-polyimide interface. Another problem with applying a polyamic acid or polyamic acid ester precursor is
The heating causes imidization, ie simultaneously releasing water (for polyamic acid) or alcohol (for polyamic acid ester) to close the ring.

This curing process causes the polymer to undergo dimensional changes such as weight loss and shrinkage. This concern can be minimized by employing a pre-imidized polyimide coating. However, most polyimides, especially those with the best packaging properties, do not dissolve,
Therefore, it cannot be applied in imidized form.

Polyimides have imide groups with various isomers. The present inventors have discovered that by supplying electrons to an isoimide, a reduced isoimide is produced, which is energetically disposed of for conversion to an n-imide.
That is, the first electron supplied is n- as a reducing imide.
It is believed that it remains on the imide, which enables the electrochemical deposition of the reduced n-imide on the conductive substrate.

The inventors have further discovered that the n-imide can use the first donated electron to initiate the isomerization of another isoimide molecule to the n-imide molecule. Therefore, the first supplied electron remains in the system without being lost. The conversion of isoimide to n-imide is catalyzed for the donated electrons remaining in the system.

Polyisoimides are generally more soluble in solvents than poly-n-imides, which are often insoluble.
Therefore, starting as a solution of a polyisoimide that is energetically tended to isomerize to a poly-n-imide that, upon reduction, readily attaches to an electrically biased conductor is It is substantially more efficient than starting as a solution of reduced poly-n-imide. The increased capacity comes from the increased solubility of the isoimide and the catalytic isoimide for n-imide conversion that re-donates electrons for use in additional conversions.
In this way, more rapid deposition can be achieved. The first electron is preferably supplied from an electrode in solution to produce a reduced isoimide when starting with an isoimide and a reduced imide when starting with an n-imide. In the former situation, the electron is available for reuse in another transformation, whereas in the latter situation, the electron is not available for reducing another poly-n-imide.

An object of the present invention is to convert an isoimide into an n-imide by supplying an electron to the isoimide, which is energetically inclined and then converted into an n-imide.

Another object of the present invention is to electrolytically deposit the imide compound on the conductive surface starting from the isoimide.

[0010]

SUMMARY OF THE INVENTION In its broadest aspect, the present invention imparts electron density to isoimide molecules whereby an isoimide is n
-It relates to a method of converting an isoimide molecule into an n-imide molecule by giving such a tendency in terms of energy for conversion into an imide molecule.

In a more particular embodiment of the present invention, donating an electron to it imparts an electron to the isoimide molecule.

In still another specific embodiment of the present invention, the electron density is imparted to the isoimide molecule by providing a drug capable of imparting an electron density overlapping with the molecular orbital of the isoimide.

In a more particular aspect of the present invention, the isoimide molecule is provided in a solution containing a biased electrode from which electrons are transferred to the isoimide,
This isoimide is energetically given a tendency to be converted into an n-imide molecule.

In yet another particular embodiment of the present invention, the isoimide molecule is provided in a solution containing a chemically or electrochemically generated reducing agent, the reducing agent transferring electrons to the isoimide molecule. , The isoimide molecule is energetically given a tendency to be converted into an n-imide molecule.

In yet another particular aspect of the invention, n
The imidized form of the polyimide can be deposited on a surface, in particular a conductive surface. The present invention allows for the deposition of polyimide on conductive surfaces, such as copper circuits, without experiencing the problems discussed above with the use of polyimide precursor polyamic acid materials. . The present invention allows for the deposition of cured polyimide on a conductive substrate.

In particular, the present invention provides a liquid composition containing an electrolyte and / or a reducing agent and a polyisoimide, and providing a conductive substrate in the liquid composition; providing an electrical bias between the substrate and the counter electrode. And depositing the polyimide on the conductive substrate to deposit the coating on the conductive substrate. Patterned deposition can be accomplished using a conductive surface that includes a non-conductive patterned layer, such as an imaged photoresist, that exposes only certain areas on the conductive surface. Features and benefits of these and other objectives include:
It will become more apparent from the following detailed description and claims.

DETAILED DESCRIPTION OF THE INVENTION Molecules useful for practicing the present invention contain an imide group conjugated to an aromatic moiety having the structure of Formulas 1 and 2. Formula 1 is the isoimide isomer and Formula 2 is the n-imide isomer.

[Chemical 1]

The polyisoimide used according to the invention can be reduced, ie it can accept electrons. Typically, polyisoimides have relatively moderate potentials (eg -0.7 to 1.3 for saturated calomel electrodes).
The electron transfer process is carried out according to V. Polyisoimides are often substantially more soluble than the poly-n-imide isomers. In their reduced form, polyimides are usually much more soluble than their neutral, oxidized forms.

Polyisoimides can be generated from poly-n-imides by the methods described in the patent applications filed on the same date as this application, the disclosures of which are incorporated herein by reference. The structures of isoimide isomers are readily apparent with reference to Formulas 1 and 2. In short, the above-mentioned co-pending application describes a method of improving the reactivity of a polyamic acid and a nucleophile by reacting a polyamic acid with an isimidizing agent to form a polyisoimide, and then reacting the polyisoimide with a nucleophile. It has been described. In one embodiment, polyamic acid is obtained by hydrolyzing a polyimide to polyamic acid. The various nucleophiles that can be reacted with the resulting polyisoimide consist of organic hydroxy compounds or organic amines. In another embodiment, a polyamic acid, such as a polyamic acid obtained by hydrolysis of the surface of an amic acid or a polyimide, is imidized with an acyl halide of a heterocyclic nitrogen compound or an acyl halide of a heterocyclic sulfur compound. To be done. This isoimidization reaction can be carried out in the presence of a heterocyclic nitrogen compound which can act as a solvent for the reactants. Isoimides, including the resulting polyisoimides, can also be reacted with nucleophiles such as organic hydroxy compounds or organic amines.

The polyimides which can be used according to the invention are unmodified polyimides and modified polyimides such as polyesterimides, polyamide-imide-esters, polyamide-imides, polysiloxane-imides,
And other mixed polyimides. Such are well known in the art and need not be described in any great detail.

Polyimides generally include the following repeating units:

[Chemical 2] [Wherein n is an integer representing the number of repeating units to give a molecular weight of about 10,000 to about 100,000. R is at least 1 selected from the group consisting of
Are tetravalent organic groups:

[0022]

[Chemical 3] (In the formula, R ² is selected from a divalent aliphatic hydrocarbon group having 1 to 4 carbon atoms and carbonyl, oxy, sulfo, sulfide, ether, siloxane, phosphine oxide, hexafluoroisopropylidene and sulfonyl group.) And R ¹ is at least one divalent group selected from the group consisting of aliphatic organic groups and:

[0023]

[Chemical 4] (In the formula, R ³ is a divalent organic group selected from the group consisting of R ² , silico, and an amino group). Two or more R and / or R ¹ groups, polymers containing R ¹ in a plurality of successive containing amide groups when can be used.

The polyimide is (a) a completely cured pre-imidized polyimide film (for example, Kapton manufactured by DuPont).
(Trademark film); (b) fully cured polyimide powder (eg Matrimide 5218 ™ from Ciba-Geigy); and (c) a polyimide precursor, especially polyamic acid (eg 2545 and 2611 from DuPont).
And commercially available from a variety of suppliers including polyamic esters. The chemistries of commercially available polyimide samples for many of their components are listed above.
Preferred polymers for use in accordance with the invention are monomers, pyromellitic dianhydride (PMDA) and oxydianiline (ODA, also referred to as 4,4'-diaminodiphenyl ether) or 3,3 ', 4, Based on 4'-benzophenone tetracarboxylic dianhydride (BTDA) and diamino 1,3,3-trimethyl-1-phenylindane (DAPI). Other polymers for use in accordance with the present invention are 3,3'-biphenylene tetracarboxylic acid (BPDA) and 1,4-phenylenediamine (PD
It is a polymer of A). Polyimide films based on PMDA-ODA are commercially available from Allied Corporation under the trade name Apical ™ and from DuPont under the trade name Kapton ™. BTDA
A polyimide based on DAPI is commercially available from Ciba-Geigy as XU-218 ™. BPDA-P
Films based on DA are commercially available from Ube Industries, Ltd. as Upilex ™ and from Hitachi Chemical Co., Ltd. as PIQ-L100 ™. Other trade names for polyimides useful in accordance with the present invention include Durimid ™ from Rogers Corporation.

All of the above examples of polyimides or polyimide precursors can be readily converted to polyisoimides by methods known in the art.
The acetylene-terminated polyisoimides are monomeric BTDA and 1,3-bis (2-aminophenoxy) benzene (A
Commercially available from National Starch, Inc. as Thermid IR ™ based on PB).

Although the inventor does not wish to be limited to a particular theory, ISO is isoimide and n-I
m is n-imide, e is electron and ISO _a
The inventor believes that the self-catalyzed isomerization of isoimide to n-imide proceeds by one of the following two series of formulas, and ISO _b pointing to two different ISO molecules: : Continuous formula 1 ISO + e → ISO ⁻ formula 3 ISO ⁻ → n-Im ⁻ formula 4 n-Im ⁻ + ISO → n-Im + ISO ⁻ formula 5 continuous formula 2 ISO _a + e → ISO _a ⁻ formula 6 ISO _a ⁻ + ISO _b → ISO _a ⁻ + n-Im Formula 7 According to Formula 3 of the continuous formula 1, electrons are supplied to the isoimide molecule to generate the reduced isoimide molecule ISO ⁻ , which is 0.1M ⁻¹ s ^−1. Isomerized to the reduced n-imide, n-IM ⁻ , according to Formula 4 with a rate constant k, which is expected to be According to Equation 5, reduction n-
The imide molecule interacts with another ISO molecule to reduce it and transfer another electron to produce another reduced imide, which is also isomerized to n-imide by Formulas 4 and 5. Therefore, the first donated electron is reused in equations 4 and 5 to initiate one or more conversions of isoimide to n-imide.

The added electron density of the reducing isoimide gives it enhanced nucleophilic properties. The general structure of the reduced isoimide group conjugated to the aromatic moiety is shown in Formula 8.

[Chemical 5] According to Sequence 2, it is this enhanced nucleophilic character of the reduced isoimide that initiates isomerization. In formula 6, the electrons are supplied to the isoimide molecule, ISO _a , to reduce ISO
_a ⁻ , which is the isoimide molecule ISO in formula 7.
_b n-imide molecule n-IM of ISO _b
Start isomerization to.

According to the present invention, a solution containing polyisoimide and an electrolyte and / or a reducing agent is used. The function of the optional reducing agent is to facilitate electron transfer from the electrode to the polymer by acting as a mediator. When a reducing agent is used, such must have an oxidation potential that is negative with respect to the reduction potential of polyisoimide. Benzyl anion, anthraquinone anion, benzophenone anion, benzoin dianion, sodium naphthalenide,
Anions of N, N'-di-n-butylpyromellitimide, compounds such as tetrakis (dimethylamino) ethylene and solvated electrons can also be used as reducing agents.

The reducing agent can be generated at the site of the reaction by electrochemical means. Alternatively, catalytically activated reducing agents such as those commonly used in electroless metallization (eg formaldehyde, borohydride ...) Can also be used.

Examples of suitable organic compounds that can be electrochemically reduced to provide a chemical reducing agent include, but are not limited to, the following group of compounds: unsaturated aromatic hydrocarbons (eg, , Anthracene), aldehydes and ketones (for example, benzaldehyde, dibenzoylmethane), imides (for example, Nn-butylphthalimide, N,
N'-di-n-butyl-3,3 ', 4,4'-biphenyltetracarboxylic acid diimide), carbodiimide (for example, bis- (p-chlorophenylcarbodiimide), aromatic heterocyclic nitrogen compound (for example, 9 , 10-diazaphenanthrene), acid anhydride (for example, 1,8-naphthalic anhydride, 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride), quinone (for example, 9,10- Anthraquinone), quaternary aromatic nitrogen compounds (for example, N-
p-biphenylbenzalimine), immonium salt (eg N-ethyl-N-methylbenzophenone immonium salt), azo compound (eg 4,4′-azobiphenyl), amine oxide (eg acridine N-oxide). , And organometallic compounds such as diphenylchromium (I) iodide.

Benzyl, N-butylphthalimide, benzophenone and anthracene are examples of specific compounds that can be reduced to obtain a chemical reducing agent suitable for carrying out the present invention. The compound can be applied to an electrochemical cell containing an anode and a cathode and then reduced by applying a voltage.

Electrochemical reduction is typically carried out using a two-compartment cell, the compartments of which are separated by a sintered glass disc frit having a porosity of less than 8 μm.
Salt bridges or semipermeable membranes can also be used to separate the compartments. The working chamber is housed in a cathode made of metal such as platinum, mercury or stainless steel. The anode is made of a conductor such as platinum, carbon, or stainless steel. For constant voltage operation, a suitable reference electrode is placed in the working chamber (eg saturated calomel electrode (SCE)). The cell can be purged with an inert gas such as N ₂ or argon using an inlet tube and a one-way valve, or can be operated in a glove box under an inert atmosphere.

Electrochemical reduction of the polyisoimide or generation of the reducing agent is accomplished by constant current, constant voltage, or voltage controlled electrolysis. Typically, the current density range for constant current reduction is 0.1-2 mA / cm ² . In the constant voltage mode, the reduction is typically more negative than the reduction potential for organic compounds measured against the same reference electrode (eg -5).
0 mV or more) is applied to the cathode.

In addition to the polyisoimide and the optional reducing agent, the solution contains an electrolyte and a salt of the electrolyte, preferably containing as a cation a member from one of the following groups: tetraalkylammonium, tetraalkylphosphonium. , Alkali metals, or chelated metals. The preferred tetraalkylammonium group is tetrabutylammonium, but other tetraalkyls in which the alkyl group is methyl, ethyl, propyl, isopropyl, pentyl, hexyl or mixed alkyls thereof can be used if desired. One example of a typical aryl group is phenyl and the arylalkylammonium is benzyltributylammonium.
An example of a chelated metal cation is potassium 18-crown-6. The electrolyte salt preferably contains as anion one of the following: tetrafluoroborate, hexafluorophosphate, arylsulphonate, perchlorate or a halide such as bromide or iodide. The solution containing the polyimide preferably comprises an aprotic solvent or solvent mixture. The requirements for the solvent are: 1. Solvate enough electrolyte to carry out the electrochemical process; 2. Solvate the polyimide into neutral and reduced forms; 3. Neutral, oxidized form. Does not solvate poly-n-imide; 4. Does not chemically react with polyisoimides or polyimides in either reduced or neutral form.

Aprotic solvents suitable for use in the present invention include, but are not limited to: nitrile and nitro compounds (eg acetonitrile, benzonitrile, nitromethane), amide and cyclic amide compounds (eg N, N-dimethylformamide, N-
Methylformamide, N, N-diethylformamide,
N-ethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, hexamethylphosphoramide), esters, cyclic esters, and ether compounds (for example, tetrahydrofuran, propylene carbonate, ethylene carbonate, γ- Butyrolactone, ethyl acetate tetrahydrofuran, dimethyl ether), oxides and sulfo compounds (eg, dimethyl sulfoxide,
Acetone, sulfolane, dimethyl sulfone).

Although the use of a polyimide and a reducing agent and / or electrolyte to form a solution has been described, it should be understood that separate solutions can be mixed to obtain the desired composition. The concentration of polyisoimide in the solution is usually about 1 to 30% by weight. The electrolyte concentration in the solution is usually 1 to about 0.01M, preferably about 0.2 to about 0.05M. When used, the concentration of reducing agent is usually from about 0.001 M to about 0.05 M, preferably about 0.00.
2M to about 0.005M.

The substrate coated with polyimide is placed in a solution containing the corresponding isoimide isomer, which is a conductive material such as palladium, platinum, silver, gold, copper, cobalt and nickel, with copper being preferred. The present invention can also be used to deposit polyimide on conductive polymers such as polyaniline, polypyrrole, and polythiophene, on conductive glass, and on superconductors and semiconductors.

Subsequently, the method of the present invention is capable of selectively coating only a predetermined portion of the substrate, which is coated only with the conductive material exposed thereby, and which is free of conductive material and <RTIgt; / or </ RTI> Portions of the substrate that have electrically conductive material already masked with a material or resin that could not be activated by the method of the invention are not coated. For example, a photoresist material that can be used for patterned deposition is Waycoat SC (Hunt Chemica
l) and KTFR (Kodak). This is important in the manufacture of advanced second level circuit cards that typically include metallized through vias that allow electrical connection between the top and bottom surfaces. High density cards also often contain metal cores that must be electrically isolated from buried metal layers or metallized vias. In the manufacture of vias by drilling, punching, etching, or abrading, insulation after the exposed metal core is often problematic. By direct electrodeposition of the imidized polyimide, these exposed metal areas can be coated to insulate the core. This method also allows for the same polyimides used for the top and bottom insulating layers.

When a bias is applied, the conductive substrate will act as an electrode, where the polyimide will attach, releasing electrons and returning to its neutral state. Also provided in the solution is a counter electrode with a bias applied between it and the substrate. The counter electrode is a material that is relatively non-reactive in the system, such as platinum or carbon.

The primary electron-reduction potential E ° for various polyimides is shown: E ° ₁ PMDA-ODA (Kapton ^R ) -0.78 BPDA-PDA (Upilex ^R ) -1.34 BTDA-DAPI ¹⁾ (XU- 218 ^R ) -1.04 BTDA-APB ³⁾ (Thermid ^R ) -0.96 NTDA-ODA ²⁾ -0.64 E ° is a reference to a saturated calomel electrode, 0.1 M tetrabutylammonium tetrachloride in acetonitrile. It was measured by cyclic voltammetry in fluoroborate. The reduction potential corresponding to polyisoimide is about 0-100 mV more positive than polyimide (easier to reduce).

1) BTDA-DAPI is Ciba under the trade name XU-281 ^R
-3,3 ', 4,4'-benzophenone tetracarboxylic dianhydride-diamino-1,3, commercially available from Geigy
It is 3-trimethyl-1-phenylindane. 2) NTDA-ODA is 1,4,5,8-naphthalenetetracarboxylic dianhydride-4,4'-oxydianiline. 3) BTDA-APB is National Starch under the trade name Thermid ^R
and 3 ', commercially available from The Chemical Company
4,4'-benzophenone tetracarboxylic acid dianhydride-
It is 1,3-bis- (2-aminophenoxy) benzene.

The process was carried out at room temperature in an inert atmosphere for about 1 to 15 minutes depending on the desired thickness of the polyimide.

Alternatively, it is envisioned that electrons or electron densities can be imparted to the isoimide groups by electron generating nucleophiles. The electron-generating nucleophile can simply be a reduced form of an organic or inorganic molecule, which does not have reducing power for complete electron transfer, but represents a significant part of the newly discovered electron density be able to. Alternatively, the nucleophile can be generated by molecular decomposition followed by electron transfer. For example, reduction of Pt (II) complexes containing amine ligands results in Pt (0) attachment and amine release.

Alternatively, it is conceivable that the electron or electron density can be photochemically imparted to the isoimide group by a photoreducing agent or a photogenerating nucleophile. Examples of known photoreducing agents include ruthenium, osmium and rhenium, and also certain bipyridyl complexes of aromatic amines. An example of a photogenerated nucleophile is a Co (III) complex of an amine whose photodegradation destabilizes the amine ligand.

The methods of donating electrons to the isoimide group described herein are merely exemplary and are not intended to limit the invention.

The following non-limiting examples are submitted to further illustrate the present invention.

Example 1 Demonstration of Isoimide Isomerization Initiated by Direct Electron Transfer Thin films of BPDA-PDA and PMDA-ODA polyamic acid (2000
~ 5000Å) spin coated onto an optically transparent electrode,
Isoimidation was achieved by exposure to trifluoroacetic anhydride. After isoimidation, the polymer has a λmax of 39.
It became a very bright yellow color near 0 nm. 0.1M tetrabutylammonium tetrafluoroborate (TBABF ₄ )
Electrochemical reduction by either reduction of the primary or secondary polymer in an acetonitrile solution containing H2O3 resulted in a characteristic yellow fading. Infrared analysis of the resulting film (KBR pellets) showed no isoimide and only stretching vibrations of n-imide.

Example 2 Demonstration of Isoimide Isomerization Mediated by Chemical Reducing Agents Thin films of BPDA-PDA and PMDA-ODA polyamic acid (2000
˜5000Å) was spin-coated on a CaF ₂ substrate for isoimidization. Polyisoimide film 0.1M and 0.0
2M benzophenone anion (E (0 /-) =-1.7
It was chemically reduced by immersion in TBABF _{4 in} an acetonitrile solution containing V). The film is then 0.1M TBABF ₄
And 0.001 M diethyl viologen diiodide (E
It was re-oxidized by immersion in an acetonitrile solution containing (2 + / +) =-0.4V). Infrared analysis is poly-n-
The quantitative conversion of both polyisoimides to the imide form was shown.

Example 3 Demonstration of Catalysis of Polyisoimide Isomerization An acetonitrile solution containing 0.1M TBABF ₄ and 0.02M isophenylphthalimide was prepared. The solution was electrochemically reduced under an inert atmosphere so that 3% of the isophenylphthalimide molecules undergo reduction (E = -1.45V). Infrared analysis of the solution showed quantitative conversion to the n-phenylphthalimide form. Thus, one electron transfer phenomenon can initiate at least 30 or more isomerizations.

EXAMPLE 4 Electrodeposition of Polyisoimide from THF Pure Thermid 6015 Polyisoimide 19% by weight and
A solution containing 1M TBABF ₄ was added to tetrahydrofuran (T
HF). The solution was degassed by N ₂ purge. Thermid 6015 is -1.0, -1.3 against SCE,
And has a reducing power at -1.8V. The optically transparent electrode was polarized at -1.6 V to reduce polyisoimide.
The reduction was carried out for 10 minutes without stirring to give polyisoimide as poly-
Isomerized to n-imide. This was subsequently polarized at 0 V and reoxidized some reduced poly-n-imide. The electrode was removed, rinsed with THF for 2 minutes and dried at 80 ° C. for 30 minutes under vacuum. The film thickness was measured by the profilometry and was 25 μm.

Example 5 Electrodeposition of polyisoimide from NMP A solution containing 3% Thermid 6015 and 0.15 M TBABF ₄ was prepared in N-methylpyrrolidone (NMP). In this case, Thermid was already partially imidized (-40%). The solution was degassed by N ₂ purge. The optically transparent electrode was polarized to -1.3 V for 0-10 minutes to reduce the polyimide, followed by reoxidation at 0V. Remove electrode, rinse with NMP and acetone, 80 ℃
And dried under vacuum for 30 minutes. The thickness of polyimide with respect to the reduction time is shown in FIG.

The present invention has been described in detail above, but the present invention can be summarized and shown by the following embodiments.

1. Providing a molecule containing an isoimide group conjugated to an aromatic moiety; and providing the isoimide group with an electron density at which the isoimide group initiates isomerization to an n-imide group conjugated to an aromatic moiety Method. 2. The method according to item 1, wherein the electron density is given electrochemically. 3. The method according to item 1, wherein the electron density is chemically given. 4. The molecule is present in a liquid containing a member selected from the group consisting of electrolytes, reducing agents and mixtures thereof,
The method according to item 1, wherein the reducing agent has an oxidation potential that is negative with respect to the reduction potential of the molecule. 5. In addition, a conductive substrate is provided in the liquid, a counter electrode is provided in the liquid; and an electrical bias is applied between the substrate and the counter electrode, thereby n-conjugated to the aromatic moiety. -The method according to item 4 above, comprising depositing an isomer of the molecule having an imide group on the conductive substrate.

6. 6. The method according to item 5, wherein the molecule is a polyisoimide molecule. 7. 7. The method according to item 6, wherein the polyisoimide is produced from pyromellitic dianhydride and oxydianiline. 8. The polyisoimide is benzophenone tetracarboxylic dianhydride and 1,3-bis (2-aminophenoxy).
7. The method according to item 6, which is produced from benzene. 9. The reducing agent is selected from anthracene anion, N-butylphthalimide anion, benzyl anion, benzophenone anion, benzoin dianion, and sodium naphthalenide, N, N'-di-n-butyl-pyromellitimide anion. The method according to item 4 above, which is selected from the group consisting of 10. 5. The method according to item 4, wherein the electrolyte contains a cation selected from the group consisting of tetraalkylammonium, tetraalkylphosphonium, alkali metal, aryl-alkyl-ammonium, tetraalkylammonium and chelate metal.

11. 11. The method according to item 10, wherein the electrolyte contains an anion selected from the group consisting of tetrafluoroborate, hexafluorophosphate, aryl sulfonate, perchlorate and halide. 12. The method according to item 4, wherein the liquid contains an aprotic solvent or a mixture. 13. 13. The method according to item 12, wherein the aprotic solvent or mixture is selected from the group consisting of nitrile compounds, nitro compounds, amides, cyclic amides, esters, cyclic esters, ethers, oxides and sulfo compounds. 14. 13. The method according to item 12, wherein the aprotic solvent or mixture is selected from the group consisting of N, N dimethylformamide, N-methyl-2-pyrrolidone and tetrahydrofuran. 15. 5. The method according to item 4, wherein the concentration of the polyisoimide in the liquid is about 0.0005M to about 5M.

16. The concentration of the electrolyte in the liquid is about 1 to
The method according to item 4 above, which is about 0.01 M. 17. The concentration of the electrolyte in the liquid is about 0.2 to about 0.05.
The method according to item 4 above, which is M. 18. 5. The method according to item 4, wherein the concentration of the reducing agent is about 0.001M to about 0.05M. 19. 5. The method according to item 4, wherein the substrate is a metal selected from the group consisting of palladium, platinum, silver, gold, copper, cobalt and nickel. 20. The method according to item 4, wherein the substrate is copper.

21. The method according to item 4, wherein the substrate is a conductive polymer, a conductive glass, or a superconductor or a semiconductor. 22. 5. The method of paragraph 4, wherein the bias produces an initial working electrode potential that is about 50 mV or more negative than the polyisoimide reduction potential, followed by a positive bias of 50 mV to 2 V of the polyimide reduction potential. 23. 5. The method according to item 4, wherein the counter electrode is platinum. 24. The method according to item 4 above, wherein the electrolyte is tetrabutylammonium tetrafluoroborate. 25. 5. The method according to item 4, wherein the reducing agent is a benzophenone anion.

26. The method according to item 1, wherein the electron density is given photochemically. 27. The method according to item 1 above, wherein the electron density is provided by donating electrons to the electron.

[Brief description of drawings]

FIG. 1 is a graph showing the relationship between the thickness of polyimide and the reduction time for deposition from a solution of isoimide.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Terence Robert Othool 1233, New York, USA Hope welfare Yankson. Creek Bend Road 15 (72) Inventor Alfredo Bibetsk 12582, New York, USA. Storm Building. Seaman Road. Earl Al number 1

Claims (5)

[Claims] 1. A molecule containing an isoimide group conjugated to an aromatic moiety is prepared; and the electron density at which the isoimide group starts isomerization to the n-imide group conjugated to the aromatic moiety is adjusted to the isoimide group. A method consisting of giving to. 2. The method of claim 1, wherein the electron density is provided electrochemically. 3. The method of claim 1, wherein the electron density is chemically provided. 4. The molecule is present in a liquid containing a member selected from the group consisting of an electrolyte, a reducing agent and mixtures thereof, and the reducing agent has an oxidation potential that is negative with respect to the reduction potential of the molecule. The method according to claim 1. 5. An electrically conductive substrate is further provided in the liquid, a counter electrode is provided in the liquid; and an electrical bias is applied between the substrate and the counter electrode, whereby an aromatic moiety is provided. Depositing an isomer of the molecule having an n-imide group conjugated to the conductive substrate.
The method of claim 4.